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  • Articles  (127)
  • Autoradiography  (67)
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  • 1970-1974  (127)
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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 10 (1972), S. 23-30 
    ISSN: 1432-0827
    Keywords: Bone ; Microradiography ; Autoradiography ; Preparation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé La préparation de coupes fines, plano-parallèles d'os non décalcifié, d'épaisseur connue, pour la réalisation de microradiographies et d'autoradiographies quantitatives est décrite. Pour éviter que des fractures de l'os se produisent, le fragment osseux fixé doit être inclus dans un matériel approprié qui ne doit pas se rétracter. Un minimum de force doit être appliqué à l'échantillon pendant la coupe pour éviter des vibrations. La méthode décrite, utilisant une scie circulaire tournant à faible vitesse, est adéquate. Le polissage final des surfaces du specimen est réalisé sur une machine à polir modifiée. On peut préparer un grand nombre de coupes en relativement peu de temps pour des études statistiques.
    Abstract: Zusammenfassung Die Herstellung von dünnen, parallelgestellten Schnitten von unentkalktem Knochen bekannter Dicke zur quantitativen Auto- und Mikroradiographie wird beschrieben. Der Knochen hat die Tendenz, unter Druck zu brechen. Um diese Schwierigkeit zu überwinden, ist es sehr wichtig, daß die fixierte Knochenprobe genügend vom Einbettungsmaterial durchdrungen wird und daß das Einschlußmittel sich vom Knochenrand weg kontrahiert. Beim Schneiden darf nur ein minimaler Druck auf die Probe ausgeübt werden, damit der Knochen nicht zertrümmert wird. Die beschriebene Methode, bei welcher eine spezielle Einrichtung zum Auftropfen des Schmiermittels den Gebrauch einer langsam rotierenden Kreissäge ermöglichte, erwies sich als günstig. Das schließliche Polieren der Oberflächen der Proben wurde auf einer modifizierten Schleifmaschine ausgeführt. Mit dieser Methode kann eine große Anzahl von Schnitten in relativ kurzer Zeit hergestellt werden; dies ist sehr wichtig, um eine angemessene Anzahl von Proben für statistische Analysen zu erhalten.
    Notes: Abstract The preparation of thin, parallel-sided sections of undecalcified bone of known thickness for quantitative auto- and micro-radiography is described. To overcome the tendency of the bone to fracture when stressed, it is essential that the fixed sample of bone should be adequately penetrated by the embedding material and that the mounting material should not contract away from the edge of the bone. Minimum stress must be applied to the sample when cutting or the bone may be shattered. The method described, using a gravity feed to a low speed circular saw, has been found to be suitable. Final polishing of the surfaces of the specimen was carried out on a modified lapping machine. Large numbers of sections can be prepared in a relatively short time by the method and this is essential to obtain an adequate number of samples for statistical analysis.
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  • 2
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    Calcified tissue international 12 (1973), S. 169-173 
    ISSN: 1432-0827
    Keywords: Calcification ; Histochemistry ; Autoradiography ; Fetal ; Mandible
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Des rats femelles reçoivent du45Ca ou du32P au 13ème et 18ème jour de la grossesse. Les coupes sériées des têtes de foetus sont étudiées par autoradiographie et par diverses méthodes histologiques pour déterminer la calcification. La détection la plus précoce de45Ca s'observe simultanément comme une réaction positive pour le calcium avec une des méthodes histologiques utilisées.32P est en évidence par les méthodes autoradiographiques un peu plus tard que le45Ca et sa présence coincide avec la réaction positive la plus précoce observée avec les autres méthodes histologiques utilisées. Les os de ces têtes foetales commencent à se calcifier selon un mode particulier commençant par la mandibule, puis l'os frontal et le maxillaire supérieur, suivis par les os nasaux, pariétaux et interpariétaux.
    Abstract: Zusammenfassung Weibliche Ratten erhielten45Ca und32P zwischen dem 13.–18. Tag der Schwangerschaft. Zur Ermittlung der Verkalkung wurden Serienschnitte der Köpfe ihrer Feten mittels Autoradiographie sowie durch verschiedene histologische Methoden untersucht. Das erste Auftreten von45Ca war ebenfalls von einer positiven Calciumreaktion mittels einer der verwendeten histologischen Methoden begleitet.32P wurde in der Autoradiographie erst etwas später als45Ca festgestellt und dessen Nachweis deckte sich mit den ersten positiven Reaktonen aller anderen verwendeten histologischen Methoden. Die Knochen in diesen Fetusköpfen begannen in einer bestimmten Sequenz zu verkalken: zuerst der Unterkiefer, dann das Stirnbein und der Oberkiefer, dann das Nasenbein, die Parietal- und Interparietalknochen.
    Notes: Abstract Female rats were given45Ca or32P from 13 to 18 days of pegnancy. Serial sections from the heads of their fetuses were studied by autoradiography, as well as by several histological methods for assessing calcification. The earliest detection of45calcium occured at the same time as a positive reaction for calcium with one of the histological methods used.32P was not detectable by autoradiographic methods until somewhat later than45Ca, and its presence coincided with the earliest positive reaction with all of the other histological methods employed. The bones in these fetal heads began to calcify in a partcular sequence, the mandible first, then the frontal bone and maxilla, followed by the nasal, parietal and interparietal bones.
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  • 3
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    Calcified tissue international 12 (1973), S. 259-279 
    ISSN: 1432-0827
    Keywords: Osteocyte ; Calvarium ; Histology ; Development ; Calcium ; Phosphorus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Des cartes tissulaires ainsi que les caractéristiques et propriétés cellularires ont été relevées au cours d'une étude de microscopie optique du développement de la calotte cranienne de souris, avant la naissance, jusqu'au 26ème jour. Les population d'ostéocytes de moitiés droite et gauche de ces calottes sont semblables, mais décroissent avec le temps dans un volume donné. De petites plages limitées de matrice osseuse se colorent pour le phosphate (ou carbonate) de façon plus nette que la matrice environnante, qui se colore légèrement après coupe. Les divers types ostéocytaires se distinguent par les réactions histochimiques du calcium et du phosphate, qui sont associés dans les cellules osseuses de façon complexe, variant dans le temps et la localisation. Ces deux constituants ne sont pas toujours présent dans les cellules des diverses régions, ou dans la même localisation dans un type cellulaire donné. En tenant compte des changements visible dans les divers types cellulaires avec le temps, dans des régions données, une hypothèse de “charge” et “décharge” cellulaire est émise.
    Abstract: Zusammenfassung Anläßlich einer mikroskopischen Studie über die Entwicklung des Mäuse-Calvariums von der Pränatalperiode bis zu 26 Tagen nach der Geburt wurden auch die Gewebetopographie sowie die Charakteristica und Eigenschaften der Zellen aufgezeichnet. Die Osteocyten-populationen in der linken und rechten Hälfte des Calvariums waren sich gleich, nahmen jedoch bei einem gegebenen Volumen mit der Zeit ab. Kleine isolierte Stellen von Knochen-matrix konnten leichter auf Ph sphat (oder Carbonat) angefärbt werden, als die umgebende Matrix, welche sich wohl am Schnitt, nicht aber am ganzen Stück färben ließ. Die verschiedenen Typen von Osteocyten wurden aufgrund histochemischer Calcium- und Phosphat-reaktionen bestimmt. Calcium und Phosphat waren innerhalb der Knochenzellen auf komplexe Art miteinander verbunden, die je nach Zeit und Lagerung unterschiedlich war. Zellen in abgetrennten Bereichen enthielten nicht immer Calcium und Phosphat und beide waren bei einer bestimmten Zellenart auch nicht immer am gleichen Ort abgelagert. Aufgrund der an ausgewählten Stellen beobachteten, zeitlich bedingten Veränderungen innerhalb der verschiedenen Zelltypen wird vorgeschlagen, daß es sich dabei um eine Sequenz von “Ladung” und “Entladung” der Zellen handelt.
    Notes: Abstract Tissue maps, and cell characteristics and properties were recorded in a study under the optical microscope of the development of the mouse calvarium from pre-natal to 26 days. Osteocyte populations in left and right halves of the calvarium were similar, but decreased with time for a given volume. Small isolated areas of bone matrix stained for phosphate (or carbonate) in a more readily available form from that in the surrounding matrix, which could be stained after sectioning but failed to stain in bulk. Osteocyte types were defined on the basis of histochemical methods for calcium and phosphate, which were associated inside bone cells in a complex manner, varying with time and position. The calcium and phosphate were not always present within the cell in discrete regions and were not always present in the same place in a given cell type. On the basis of a study of changes in cell types with time in selected sites a sequence of “loading” and “unloading” is proposed.
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  • 4
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    Calcified tissue international 16 (1974), S. 209-217 
    ISSN: 1432-0827
    Keywords: Mucopolysaccharides ; Collagen ; Calvarium ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Mucopolysaccharides (MPS) and collagen have been analyzed in different types of cartilage and some other tissues at various stages of prenatal and postnatal human development. The concentration of the chondroitin sulfate-type MPS increased from the 38th embryonal day, the 6-sulfate exceeding in amount the 4-sulfate. The increase in collagen concentration was accompanied by a decrease in the proportion of neutral salt-soluble collagen. There was no accumulation of chondroitin sulfates in the calvaria. A maximal concentration of MPS of a low molecular weight occurred in the skin and in the ear pinna after the 10th prenatal week. Postnatally, the MPS-concentration in the iliac crest and in the tibial articular cartilages decreased gradually, the highest values being reached in the newborn; the collagen-concentration showed an approximately reciprocal course.
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  • 5
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    Calcified tissue international 7 (1971), S. 114-132 
    ISSN: 1432-0827
    Keywords: Osteoporosis ; Sodium-deficiency ; Histology ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Ce travail étudie les effets d'une carence en sodium sur le squelette chez le Rat en croissance. Il a été effectué sur 3 groupes de Rats: groupe carencé, groupe témoin sous-nutri et groupe témoin normal. L'étude macroradiographique et microradiographique des tibias révèle que la carence en sodium provoque en 8 semaines une diminution de la longueur, un amincissement de l'espace métaphyso-épiphysaire et l'apparition d'une ostéopénie. Cette ostéopénie prédomine sur la métaphyse par rapport à la diaphyse. Au niveau de celle-ci, le rapport cortico-diaphysaire est diminué. Ce changement est essentiellement dû à l'amincissement de l'os cortical par sa face périphérique. Le marquage par la tétracycline confirme cette atteinte prédominante de l'apposition périostée. L'étude histologique et l'étude autoradiographique suggèrent que cette ostéopénie résulte d'un important ralentissement de l'ostéogénèse et de l'activité globale du tissu osseux. L'analyse chimique révèle des changements minimes de la composition des fémurs. La teneur en cendres est légèrement abaissée. La rapport Ca/P est légèrement augmenté. Les rapports Ca/N et P/N sont diminués. Le rapport Na/Ca est augmenté. Les mécanismes possibles de cette atteinte squelettique sont envisagés: sous-nutrition, effet acidifiant du régime, trouble de l'absorption intestinale du calcium, retentissement surrénal et conséquences cellulaires de la carence en sodium. En conclusion, dans le déterminisme de l'atteinte osseuse semblent devoir être retenus: a) l'inanition dûe à l'anorexie provoquée par le régime désodé, b) und effet squelettique propre de la carence en sodium, le trouble de l'absorption intestinale du calcium ne paraissant pas jouer un rôle déclenchant.
    Abstract: Zusammenfassung In dieser Arbeit wurde der Einfluß eines Natriummangels auf das Skelet der noch wachsenden Ratte beobachtet. Die Studie betrifft drei Gruppen von Ratten: eine mit Natriummangel, eine normal ernährte und eine unterernährte Kontrollgruppe. Die makro- und mikroradiographische Untersuchung der Tibiae nach 8wöchigem Natriummangel zeigt eine Verkürzung, eine Verringerung des metaphyso-epiphysären Intervalls und eine Osteopenie, die in der Metaphyse merkbarer als in der Diaphyse ist. Das corticodiaphysische Verhältnis ist herabgesetzt, und zwar verjüngt sich der Knochencortex peripherisch. Mit markiertem Tetracyclin wird bewiesen, daß vorwiegend die periphere Knochenbildung betroffen ist. Die histologische und autoradiographische Untersuchung erlaubt die Annahme, daß diese Osteopenie auf stark verlangsamte Knochenbildung und gesamte metabolische Tätigkeit des Knochengewebes zurückzuführen ist. Die chemische Analyse weist unerhebliche Änderungen der Zusammensetzung der Femora auf. Der Aschengehalt ist leicht vermindert. In den Epiphysen ist Ca/P leicht erhöht. Ca/N und P/N sind herabgesetzt. Na/Ca ist wenig verändert. Die möglichen Mechanismen dieser Skeletveränderungen werden erörtert: Unterernährung, diätbedingte Säurebildung, Störung der intestinalen Calciumabsorption, Nebennieren-beeinflussung und Zellstoffwechselveränderungen durch Natriummangel. Zusammenfassend scheint hauptsächlich die Unterernährung eine Rolle zu spielen. Dazu kommen die direkten Folgen des Natriummangels auf den intestinalen Zucker- und Aminosäurentransport.
    Notes: Abstract The effects of sodium deficiency on the skeleton were studied in growing rats assigned to 3 groups: sodium deficient group, pair-fed controls, normal controls. Macroradiographic and microradiographic examinations and measurements of the tibia demonstrated that sodium deficiency after 8 weeks resulted in shorter bones, thinner cartilage and osteopenia. This osteopenia was greater in metaphysis than in diaphysis. However the cortico-diaphyseal ratio decreased, resulting from cortical bone thinning by the periosteal side. Histologic and autoradiographic examinations suggested that this osteopenia resulted from a marked slowing down of osteogenesis and total bone turnover. The mineral composition of the femur was little changed. The ash rate, Ca/N and P/N ratios decreased slightly. The Ca/P ratio increased slightly. The Na/Ca ratio increased also. The following possible mechanisms of skeletal damage were considered: undernutrition, acidifying effect of diet, fall of calcium intestinal absorption, adrenal and cellular changes resulting from the sodium deficiency. In conclusion, the bone lesions appear to be caused by undernutrition and in addition by a skeletal effect specifically due to sodium deficiency.
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  • 6
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    Journal of molecular evolution 3 (1974), S. 109-113 
    ISSN: 1432-1432
    Keywords: “Custom Fitting” ; Development ; Evolution ; Antibody response ; Genetic Redundancy ; Perturbation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary When the complexity of a developmental system evolves to a certain point, appreciable variation must occur in the process. The problem the biologist faces is whether this point constitutes a limit to the evolution of complexity in developmental systems. If not, what mechanisms are employed to cope with the problem ? The problem—essentially one in “custom fitting” of parts, — and the possible solution(s) to it that have evolved are discussed. The antibody producing system appears to be one that “solves” the custom-fitting problem.
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  • 7
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    Calcified tissue international 8 (1971), S. 121-132 
    ISSN: 1432-0827
    Keywords: Calcium ; Skeleton ; Autoradiography ; Isotope ; Deposition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Le taux de formation osseuse d'un chien adulte a été déterminé en divers endroits, en utilisant deux marqueurs à la tétracycline. Les valeurs obtenues ont été comparées avec des mesures similaires de dépôts calciques, obtenues par45Ca. Les mesures du ≪marquage diffus≫ de45Ca ont également été réalisées en utilisant l'autoradiographie quantitative. Les résultats ont été comparés avec les études similaires de Leeet coll. (J. Bone Joint Surg.47B, 157, 1965), effectuées à l'aide d'un chien nouveau-né et d'un chien adolescent. Il apparait ainsi que les études au45Ca permettent de mesurer la formation osseuse chez les chiens d'âges différents. Cependant, il est probable que le ≪marquage diffus≫ de calcium marqué chez l'Homme rend difficile la mesure du dépôt de calcium.
    Abstract: Zusammenfassung Die Geschwindigkeit der Knochenbildung bei einem ausgewachsenen Hund wurde mittels 2 Tetracyclinmarkierungen an verschiedenen Stellen des Knochens gemessen. Durch Messungen der Calciumzuwachsrate mittels45Ca-Tracer konnten die Werte beider Methoden verglichen werden. Die „diffuse Markierung” von45Ca wurde anhand von quantitativer Autoradiographie ebenfalls gemessen. Die Resultate wurden mit denjenigen ähnlicher Studien ausgewachsener Hund verwendet wurden. Es wird daraus geschlossen, daß die Knochenbildungsgeschwindigkeit von Hunden aller Altersstufen anhand von45Ca-Tracer-Studien gemessen werden kann. Es ist jedoch wahrscheinlich, daß die „diffuse Makierung” mit Tracer-Calcium beim Menschen zu einer schwierigen Interpretation der Messung der Calciumzuwachsrate führt.
    Notes: Abstract The bone formation rate of an adult dog has been found at several bone sites using two tetracycline markers. The values found have been compared with similar measurements of calcium accretion rate using45Ca as a tracer. Measurements of the “diffuse label” of45Ca were also made using quantitative autoradiography. The results have been compared with similar studies by Leeet al. (J. Bone Joint Surg.47 B, 157, 1965) using a puppy and an adolescent dog. It is concluded that45Ca tracer studies can measure the bone formation rate of dogs at any age. However, it is probable that the “diffuse label” uptake of tracer calcium in humans makes the calcium accretion rate measurement difficult to interpret.
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  • 8
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    Calcified tissue international 7 (1971), S. 267-276 
    ISSN: 1432-0827
    Keywords: Tech ; Development ; Enamel ; Enzyme ; Histochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé L'activité en naphtylamidase est étudiéc au niveau des incisives et molaires de rat, à divers stades de développement. Du L-leucyl-4-methoxy-2-naphtylamide, du L-alanyl-4-methoxy-2-naphtylamide, du L-leucyl-2-naphthylamide et du DL-alanyl-2-naphtylamide sont utilisés comme substrats: du bleu rapide B et du grenat rapide GBC sont employés comme sels de diazonium. Le naphtylamidase n'est pas visible au niveau de dents, en voie de dévelopment, au cours de la formation matricielle de l'émail. A la fin de ce stade, le naphtylamidase est présent au niveau de l'extrémité distale des améloblastes, près de la surface de l'émail. L'activité enzymatique reste identique jusqu'au moment de la fusion de l'épithélium dentaire et de l'épithélium buccal, au moment de l'éruption de la dent dans la cavité buccale. On ne rencontre pas de naphtylamidase au niveau d'autres tissues dentaires; cependant une activité marquée est observée dans les ostéoclastes au niveau des surfaces de résorption de l'os alvéolaire, entourant les dents, en voie de développement et d'éruption, et dans certaines régions du tissu conjonctif.
    Abstract: Zusammenfassung Die Aktivität der Naphthylamidase wurde in den Backen- und Schneidezähnen von Ratten in verschiedenen Entwicklungsstufen studiert. Als Substrate wurden L-leucyl-4-methoxy-2-naphthylamid, L-alanyl-4-methoxy-2-naphthylamid, L-leucyl-2-naphthylamid und DL-alanyl-2-naphthylamid verwendet; als Diazoniumsalze dienten Echtblau B und Echt-Granat GBC. Naphthylamidase konnte während der Schmelzmatrixbildung im Zahn nicht nachgewiesen werden. Nach Abschluß dieser Phase erschien Naphthylamidase in den distalen Enden der Ameloblasten, nahe bei der Schmelzoberfläche. Die Enzymtätigkeit blieb am selben Ort lokalisiert, bis das Zahnepithel, im Augenblick wo der Zahn in die Mundhöhle durchstößt, in das Mundepithel überging. Naphthylamidase wurde in anderen Zahngeweben nicht gefunden, aber eine deutliche Aktivität konnte in gewissen Bezirken des Bindegewebes sowie in den Osteoklasten der resorbierenden Oberflächen vom alveolären Knochen festgestellt werden, welcher die sich bildenden und die hervorstoßenden Zähne umgibt.
    Notes: Abstract Naphthylamidase activity was studied in rat molar and incisor teeth at different stages of development. L-leucyl-4-methoxy-2-naphthylamide, L-alanyl-4-methoxy-2-naphthylamide, L-leucyl-2-naphthylamide and DL-alanyl-2-naphthylamide were used as substrates and Fast blue B and Fast Garnet GBC as diazonium salts. Naphthylamidase was not demonstrable in the teeth during enamel matrix formation. After the termination of this stage, naphthylamidase was present in the ameloblasts in their distal ends close to the enamel surface. The enzyme activity retained this localization until the dental epithelium fused with the oral epithelium at the time of tooth eruption into the oral cavity. Naphthylamidase was not found in other dental tissues, but marked activity was found in osteoclasts at the resorbing surfaces of alveolar bone surrounding the developing and erupting teeth and in certain areas of the connective tissue.
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  • 9
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    Calcified tissue international 9 (1972), S. 122-130 
    ISSN: 1432-0827
    Keywords: Tetracycline ; Development ; Calcification ; Statolith ; Nematocysts ; Aurelia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé L'effet de la tétracycline HCl sur la synthèse de statolithes de sulfate de calcium chezAurelia a été étudié. La tétracycline inhibe la synthèse de statolithes et nématocystes à un stade précoce de strobilation. La tétracycline, cependant, n'est pas incorporée dans les statolithes ou nématocystes en formation. Comme la tétracycline ne se combine pas avec le calcium des statolithes de sulfate de calcium dihydraté d'Aurelia, l'explication des effets d'inhibition sur la différenciation de statolithes et nématocystes ne semble pas liée avec un facteur en rapport avec l'incorporation. Des étudesin vitro de quatre systèmes inorganiques de calcium et de tétracycline montrent que le sulfate de calcium dihydraté (gypse) n'incorpore pas la tétracycline: il en est de même de son équivalent isostructural, le phosphate de calcium hydrogéné dihydraté (brushite). Le carbonate de calcium et le phosphate de calcium (apatite) incorpore la tétracycline. L'explication des différences de comportement du calcium peut être liée à la structure cristalline des composés respectifs, et, en particulier, au fait que l'ion Ca est prêt ou non à réagir avec la tétracycline.
    Abstract: Zusammenfassung Es wird über die Wirkung von Tetracyclinchlorhydrat auf die Synthese von Calciumsulfat-Statolithen beiAurelia berichtet. Wird das Tetracyclin in einem Frühstadium der Strobilation verabreicht, so hemmt es die Synthese der Statolithen und der Nematocysten. Das Tetracyclin wird jedoch nicht in die sich bildenden Statolithen oder Nematocysten eingebaut. Da sich das Tetracyclin nicht mit dem Calcium der Calciumsulfatdihydrat-Statolithen derAurelia verbindet, so kann dessen Hemmwirkung auf die Statolithen und die sich differenzierenden Nematocysten offenbar nicht mit einem einbaubedingten Faktor erklärt werden. Untersuchunge, die in vitro mit vier verschiedenen anorganischen Calciumsalzen und Tetracyclin ausgeführt wurden, zeigten, daß weder Calciumsulfatdihydrat (Gips), noch dessen isotrukturelles Aequivalent Calciumhydrogenphosphatdihydrat (Bruschit) Tetracyclin einbauen. Dagegen inkorporieren Calciumcarbonat und Calciumphosphat (Apatit) das Tetracyclin. Die Erklärung für dieses unterschiedliche Verhalten der Calciumsalze findet sich in der Kristallstruktur der betreffenden Verbindungen, d.h. es hängt davon ab, ob das Calciumion ür die Reaktion mit Tetracyclin leicht verfügbar ist.
    Notes: Abstract The effect of tetracycline HCl on synthesis of calcium sulphate statoliths inAurelia is reported. Tetracycline inhibits synthesis of statoliths and nematocysts when administered at an early stage of strobilation. The tetracycline, however, is not incorporated into the developing statoliths or nematocysts. As the tetracycline does not combine with the calcium of the calcium sulfate dihydrate statoliths ofAurelia, an explanation for its inhibitory effects on statoliths and nematocyst differentiation apparently does not rest with an incorporation-related factor. In vitro studies of four inorganic calcium systems and tetracycline revealed that calcium sulfate dihydrate (gypsum) did not incorporate tetracycline nor did its isostructural equivalent, calcium hydrogen phosphate dihydrate (brushite). Calcium carbonate and calcium phosphate (apatite) did incorporate tetracycline. The explanation for these different behaviors of calcium can be found in the crystal structure of the respective compounds, namely, whether or not the Ca ion is readily available to react with tetracycline.
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  • 10
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    Calcified tissue international 7 (1971), S. 201-211 
    ISSN: 1432-0827
    Keywords: Autoradiography ; Calcium ; Oviduct ; Shell-gland
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé La localisation cellulaire du calcium de la muqueuse de l'oviducte d'oiseaux a été étudiée par autoradiographie au45Ca, à partir de tissus préparés soit par incubation dans le45Ca, soit par injection intraveneuse du45Ca. La congélation — substitution est utilisée pour retenir le calcium aisément diffusible dans le tissu. L'épithelium cylindrique de la glande de la coquille s'enrichit significativement plus en45Cain vitro, en fonction de l'augmentation du temps d'incubation, de une à dix minutes et/ou en élevant la température de 0° à 42°. Ces effets sont diminués par l'adjonction de dinitrophenol au milieu d'incubation. Les glandes tubulaires de ce tissu réagissent à peine. Généralement, après injection intravenieuse de45Ca, la glande de la coquille retient plus de radionuclide que les autres régions de l'oviducte. Lorsqu'une coquille d'œuf est en voie de calcification, l'épithelium cylindrique de cette glande contient plus de grains que les glandes tubulaires, mais, en cas d'absence de formation d'œuf, le nombre de grains est identique dans les 2 types cellulaires. Il semble que l'épithélium cylindrique de la glande de la coquille a une affinité plus grande et plus variable pour le45Ca que la glande de la coquille les glandes tutulaires ou les cellules muqueuses d'autres régions de l'oviducte. Ces résultats indiquent sans le prouver, que l'épithélium cylindrique est plus actif dans le transfert du calcium des vaisseaux sanguins vers la lumière de la glande de la coquille.
    Abstract: Zusammenfassung Die celluläre Verteilung von Calcium in der Eileitermucosa von Hühnern wurde anhand von45Ca-Autoradiographien in Gewebe studiert, welches entweder durch Inkubation mit45Ca oder durch intravenöse Injektion von45Ca präpariert wurde. Gefriersubstitution wurde verwendet, um leicht diffundierbares Calcium im Gewebe zurückzuhalten.In vitro nahm das Cylinderepithel der Schalendrüse auffallend mehr45Ca auf, wenn die Inkubationszeit von einer auf zehn Minuten verlängert wurde und/oder wenn die Temperatur von 0° auf 42° erhöht wurde. Diese Wirkungen wurden durch die Zugabe von Dinitrophenol zum Inkubations-medium vermindert. Die Tubulärdrüsen dieses Gewebes reagierten kaum. Im allgemeinen schlossen die Schalendrüsen nach intravenöser Injektion von45Ca mehr Radionuklid ein als andere Teile des Eileiters. Wenn eine Eierschale calcifizierte, zeigte das Cylinderepithel der Schalendrüse bei der Autoradiographie eine höhere Anzahl von Silberkörnern als die Tubulärdrüsen, aber wenn keine Schale gebildet wurde, war sie bei beiden Zelltypen ähnlich. Die Resultate zeigen, daß das Cylinderepithel der Schalendrüse, eine größere und unterschiedlichere Affinität für45Ca hat als Schalendrüse Tubulärdrüsen oder Schleimhautzellen aus anderen Gebieten des Eileiters. Die Befunde deuten darauf hin, aber beweisen es nicht, daß das Cylinderepithel beim Transport von Calcium aus den Blutgefäßen in die Schalendrüse das aktivste ist.
    Notes: Abstract The cellular location of calcium in the mucosa of the avian oviduct has been studied by45Ca autoradiography in tissue prepared either by incubation with45Ca or by intravenous injection of45Ca. Freeze-substitution was used to retain easily diffusible calcium in the tissue.In vitro, columnar epithelium of the shell gland acquired significantly more45Ca as the length of incubation time was increased from one to ten minutes and/or when the temperature was raised from 0° to 42°. These effects were diminished by the addition of dinitrophenol to the incubation medium. The tubular glands of this tissue responded minimally. Genrally, after intravenous injection of45Ca, the shell gland sequestered, more radionuclide than the other regions of the oviduct. When an egg shell was being calcified, the columnar epithelium of the shell gland revealed a higher grain count than the tubular glands, but when a shell was not forming, grain counts were similar over the two types of cells. The results show that the columnar epithelium of the shell gland has a greater and more variable affinity for45Ca than have the shell gland tubular glands or mucosal cells from other regions of the oviduct. The data suggest, but do not prove, that the columnar epithelium is the most active in translocation of calcium from the blood vessels to the lumen of the shell gland.
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    Calcified tissue international 9 (1972), S. 173-178 
    ISSN: 1432-0827
    Keywords: Phosphatase ; Development ; Bone ; Growth ; Rhythm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Une étude longitudinale, par séries, est effectuée pour déterminer les activités en phosphatases acide et alcaline dans les os longs et la mandibule. Le pH optimum des deux enzymes se situe respectivement à 10.2 et 5.4 pour les phosphatases alcaline et acide. Des portées synchronisées de rats sont sacrifiées, à raison d'une portée par jour, en commençant au premier jour jusqu'au 25ème jour post-partum. Les spécimens sont analysés en ce qui concerne leur concentration en protéine et leur activité en phosphatases. Une activité de types élevée et faible est observée au niveau du tissu osseux, ainsi qu'un type d'activité faible en phosphatase alcaline, au cours des pics d'activité en phosphatase acide, et vice-versa. Les pics observés suggèrent une concordance entre l'activité en phosphatase et les autres changements biochimiques de la croissance osseuse, au niveau de la matrice organique et la formation minérale. Une étude séparée, tenant compte de la possibilité d'une activité enzymatique rythmique, suggère l'existence d'un rythme diurne court chez les animaux jeunes.
    Abstract: Zusammenfassung Eine serienmäßige Longitudinaluntersuchung wurde unternommen, um die Aktivitäten der alkalischen und sauren Phosphatase in den Röhrenknochen und den Mandibulae von Ratten zu bestimmen. Das pH-Optimum der beiden Enzyme wurde für die alkalische Phosphatase bei 10,2 und für die saure Phosphatase bei 5,4 ermittelt. Synchronisierte und randomisierte Würfe wurden getötet, 1 Wurf pro Tag vom 1.–25. Tag post partum. Die Proben wurden auf ihren Proteingehalt und ihre Phosphatasenaktivität untersucht. Ein Muster niedriger und hoher Aktivität konnte in beiden Knochengeweben beobachtet werden, sowie ein Muster von niedriger Aktivität der alkalischen Phosphatase bei Spitzenwerten der sauren Phosphatase und umgekehrt. Die beobachteten Spitzenwerte lassen einen Zusammenhang vermuten zwischen der Phosphatasenaktivität und den anderen biochemischen Veränderungen, die im wachsenden Knochen auftreten, d. h. Bildung der organischen Matrix und des Minerals. Eine getrennte Untersuchung, welche sich mit der Möglichkeit rhythmischer Merkmale der Enzymaktivität befaßte, läßt vermuten, daß in den ersten Tagen ein schwacher Tagersrhythmus bestehen könnte.
    Notes: Abstract A serial longitudinal study was undertaken to determine the activities of the alkaline and acid phosphatases in the long bones and mandibles. The optimum pH of the two enzymes was recorded at 10.2 and 5.4 for alkaline and acid phosphatase, respectively. Synchronized and randomized litters of rats were killed, 1 litter daily, starting at day 1 to day 25 post partum. Samples were analyzed for protein concentration and activity of the phosphatases. A pattern of low and high activity was observed in both bony tissues, as well as a pattern of low alkaline phosphatase activity during acid phosphatase activity peaks, and vice versa. The observed peaks suggest a correspondence between phosphatase activity and the other biochemical changes occurring in the growing bone, i.e., organic matrix and mineral formation. A separate study, considering the possibility of rhythmic features of the enzyme activity suggests that there may be a small diurnal rhythm at an early age.
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    Archives of microbiology 96 (1974), S. 353-364 
    ISSN: 1432-072X
    Keywords: Coprinus ; Agaricaceae ; Mushroom ; Development ; Growth Regulator ; Stipe Growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Some of the morphological and physiological parameters of stipe growth or elongation inCoprinus radiatus were investigated. During the development of the fruit body the number of cells in a row in the growing portion of the stipe doubled during the development of the button, and again during the phase of rapid stipe elongation. Also during the stage of rapid elongation the cells in the upper 2/3 of the stipe increased 6–8 fold in length. The existence of a growth regulator synthesized in the cap and exerting control over the stipe was demonstrated through decapitation experiments. The cap appears to be required for normal stipe development until the stipe reaches about 1/4 of its final length. Through decapitation and cap-stipe exchanges it was found that the cap produced growth regulator up to the time of autodigestion; however, the stipe responded to the regulator only during a brief period at the onset of elongation.
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    Archives of microbiology 99 (1974), S. 255-263 
    ISSN: 1432-072X
    Keywords: Mannan Synthesis ; Saccharomyces cerevisiae ; Autoradiography ; Cell Wall ; Yeast
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The combination of high-resolution autoradiography and biochemical methods has been used to ascertain the site of mannan synthesis in the yeastSaccharomyces cerevisiae. High-resolution autoradiography has been performed under conditions when addedd-mannose-3H was incorporated exclusively into mannan. Application of “pulse-chase” labelling technique revealed that the radio-active mannose is fixed primarily in the cytoplasmic space from where it is transported into the cell wall. Additional experiments with separated membrane fractions from the same yeast strongly support the hypothesis that the plasmalemma is not directly involved in the biosynthesis of yeast mannan and that the membranes of the endoplasmic reticulum are the sites where the polymerization of mannosyl units takes place.
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    Archives of microbiology 99 (1974), S. 331-344 
    ISSN: 1432-072X
    Keywords: Myxomycetes ; Ultrastructure ; Development ; Systematics ; Food Vacuoles ; Stalk Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Observations of sporophore development in fresh and glutaraldehydeosmium sequentially-fixed material ofProtophysarum phloiogenum show the following sequence. Small plasmodia cease streaming and round up. Food vacuoles collect in the lower center of the cytoplasmic mass. As the cytoplasm rises the food vacuolar contents are excluded from the plasmalemma and become the stalk core. A continuous, fibrous peridium and stalk tube enclose cytoplasm and stalk core respectively. Capillitial formation just precedes spore cleavage. Sporophore development is marked by autophagic activity and calcium deposition. Stalks of dried herbarium specimens of seven additional species have been examined. A mature stalk morphology very similar toProtophysarum with recognizable remnants of microorganismal food material is seen in all of them. It is thought that this marker is indicative of non-stemonitaceous stalk development.
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    Archives of microbiology 99 (1974), S. 155-166 
    ISSN: 1432-072X
    Keywords: cAMP ; Acanthamoeba ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Durch drei verschiedene Methoden wurde in Kulturen vonAcanthamoeba castellanii die stationäre Wachstumsphase, in deren Verlauf sich Trophozoiten zu Cysten entwickeln, induziert: Durch Nahrungsmangel, indem Amöben der logarithmischen Wachstumsphase in ein nährstofffreies Medium überführt wurden, durch Sauerstoffmangel, indem Kulturen zu großer Zelldichte heranwuchsen, und durch Hemmung der mitochondrialen DNS-Synthese, indem Kulturen der logarithmischen Phase mit Äthidiumbromid versetzt wurden. Unabhängig von den Encystierungsbedingungen nimmt die intracelluläre Konzentration von Adenosin-3′,5′-monophosphat (cAMP) bei Verminderung der Zellteilungsrate bis zu Beginn der stationären Wachstumsphase um das 2–3 fache zu. Die Ergebnisse deuten an, daß der Anstieg von intracellulärem cAMP auf eine Erhöhung der Adenylat-Cyclase- und nicht auf eine Verminderung der Phosphodiesterase-Aktivität zurückzuführen ist. Extracelluläres cAMP konnte weder in Kulturen der logarithmischen noch in Kulturen der stationären Phase nachgewiesen werden. Dies ist vermutlich auf die extracellulär vorhandene cAMP-Phosphodiesterase zurückzuführen. Die Tatsache, daß auch durch Theophyllin die stationäre Wachstumsphase und Encystierung induziert werden kann, läßt auf eine Beteiligung von cAMP an den Entwicklungsprozessen, speziell an dem Abbau von Glykogen, schließen.
    Notes: Abstract In cultures ofacanthamoeba castellanii the stationary growth phase in which trophozoites develop to cysts, was induced in three ways: by transferring cells from a logarithmic growing culture into a nutrient-free medium, by growth in nutrient medium to high cell density and by inhibition of the mitochondrial DNA synthesis with ethidium bromide. In all cases, the intracellular concentration of adenosine-3′,5′-monophosphate (cAMP) rises by a factor of two to three from the end of the logarithmic phase to the beginning of the stationary phase. The results show that this rise may be more a consequence of an increased adenylate cyclase activity than of a diminished cAMP phosphodiesterase activity. No extracellular cAMP could be measured in cultures of the logarithmic and stationary growth phase, perhaps because of the extracellular cAMP phosphodiesterase. Because theophylline also induces the stationary phase and encystation, cAMP seems to be of importance for the development ofAcanthamoeba castellanii, especially for the degradation of glycogen.
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    Archives of microbiology 101 (1974), S. 391-399 
    ISSN: 1432-072X
    Keywords: Adenosinephosphate System ; Energy Charge ; Acanthamoeba ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Die Konzentration von Adenosintri-, Adenosindi- und Adenosinmonophosphat wurde in Acanthamoeba castellanii währed der logarithmischen Wachstumsphase und der stationären Wachstumsphase, in deren Verlauf sich Trophozoiten zu Cysten entwickeln, bestimmt. Der Entwicklungsprozess wurde durch drei verschiedene Methoden hervorgerufen: Durch Wachstum im Nährmedium zu großer Zelldichte, durch Überführen von Amöben der logarithmischen Wachstumsphase in ein nährstoffreies Salzmedium und durch Versetzen logarithmisch wachsender Amöben mit Äthidiumbromid. In allen Fällen wird der Adenosinphosphat-Gehalt in den Zellen im Laufe der Entwicklung um etwa 85% reduziert, wozu besonders die Abnahme des ATP-Gehaltes beiträgt. Die Adenosinphosphat-“energy charge” beträgt in logarithmisch wachsenden Amöben 0,83. Im Laufe der Entwicklung wird sie je nach Encystierungsbedingungen auf unterschiedlichen Werten stabilisiert (zwischen 0,58 und 0,81). Die Möglichkeit eines Zusammenhanges von Konzentrationsveränderungen der Adenosinphosphate und entwicklungsspezifischen Prozessen wird diskutiert.
    Notes: Abstract The concentration of adenosine tri-, adenosine di-, and adenosine monophosphate in cells of Acanthamoeba castellanii was measured during the logarithmic growth phase and the stationary growth phase in which trophozoites were transformed into cysts. This developmental process was induced in three ways: by growth in nutrient medium to high cell density, by transferring cells in the logarithmic phase into a nutrient-free medium, and by mixing logarithmically growing cells with ethidium bromide. In all cases, encystment is accompanied with a reduction of total adenosine phosphate content to about 85%, mainly because of a depletion of cellular ATP. The value of the adenosine phosphate energy charge in logarithmically growing amoebae is 0.83. During development the energy charge becomes stabilized at different values (between 0.58 and 0.81), characteristic to the mode of encystation. A possible functional relationship between changes of the adenosine phosphate concentration and developmental processes of the amoeba is discussed.
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    Cell & tissue research 108 (1970), S. 380-396 
    ISSN: 1432-0878
    Keywords: Epicuticle ; Insects ; Tenebrio molitor ; Development ; Structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé L'épicuticule de l'adulte de Tenebrio molitor est composée de deux couches distinctes dénommées épicuticule externe et épicuticule interne. L'épicuticule externe est la première couche cuticulaire sécrétée sous forme de petites plaques s'agrandissant par leurs bords pour recouvrir toute la surface cellulaire. Au moment de sa sécrétion, cette couche est formée de quatre lames denses A, B, C1 et C2. La lame B, très fine, disparaît par la suite et les lames C1 et C2 deviennent très nettes. L'épicuticule externe de l'adulte est donc formée de trois lames denses séparées par deux lames claires. L'épicuticule interne est formée de lames superposées denses et claires de structure complexe, qui sont masquées pendant la sécrétion des premières couches de cuticule lamellée (procuticule). Cette structure correspond à un arrangement moléculaire hautement organisé. La forme de la surface cuticulaire des sternites est déterminée par la forme de la surface cellulaire avant le dépôt de l'épicuticule.
    Notes: Summary The epicuticle of adult Tenebrio consists of two distinct layers named outer and inner epicuticle. The outer epicuticle is the first cuticular layer to be deposited in form of small patches on top of the microvilli. These initial patches are composed of four dense laminae (A, B, C1 and C2) separated by three light spaces. The outer epicuticle grows by densification of diffuse material at the edges of the patches until the entire area is covered. The thickness of outer epicuticle remains constant (175 Å) during the development of the pharate adult, lamina B however rapidly disappears. Thus, the adult outer epicuticle is fivelayered (three dense laminae: A, C1 and C2). After being deposited, the inner epicuticle shows a complex laminar structure interpreted to represent a highly organized molecular system. The laminae are masked during the formation of the first procuticle lamellae. During the deposition of the epicuticle, lamina A is covered by a component of the moulting fluid, forming an irregular dense layer which disappears after the resorption of this fluid. Perhaps this layer protects the new epicuticle from lytic enzymes of the moulting fluid. In adult animals, there is an additional superficial layer, the signification of which is not clear. The possibility of remains of cement or wax is discussed. The development of the surface patterns of the sternal and pleural cuticle is determined before the epicuticle formation by the shape of the epidermal surface. The rate of outer epicuticle deposition appears to depend on the size of the microvilli: epicuticle deposition seems to proceed faster over high microvilli.
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    Cell & tissue research 109 (1970), S. 1-14 
    ISSN: 1432-0878
    Keywords: Seminal vesicle ; Prostate ; Fetal rat ; Ultrastructure ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The development of the seminal vesicle from the Wolffian duct and of the prostate from the urogenital sinus has been studied in rat fetuses from day 14 of gestation to birth with the use of the electron microscope. Prior to the onset of androgen secretion, the cells of the urogenital sinus and the caudal part of the Wolffian duct have a simple undifferentiated appearance. After the onset of androgen secretion by the fetal testes at day 15, “intracytoplasmic confronting cisternae” of the granular reticulum appear in both urogenital sinus and Wolffian duct. Portions of the granular endoplasmic reticulum of the urogenital sinus become distended with a finely granular, moderately dense material. In the urogenital sinus, many hemidesmosomes are formed at the basal surface of the epithelium. Specializations of the extracellular materials are present opposite the hemidesmosomes. The formation of the seminal vesicles and the prostate begins at day 18–19 of gestation. The cells of the seminal vesicle are taller than the Wolffian duct cells from which they arise, the granular endoplasmic reticulum increases moderately in amount, and a patent lumen is formed. The cells of the fetal prostate do not differ greatly from those of the urogenital sinus from which they arise except that the prostatic cells initially lack hemidesmosomes. The fine structural changes are discussed in relation to the onset of fetal androgen secretion, the formation of the organs, and the functions of the cells in adult life.
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    Cell & tissue research 111 (1970), S. 75-89 
    ISSN: 1432-0878
    Keywords: Lymphocytes ; Replacement rate ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Bei jugendlichen erwachsenen, weiblichen Ratten wurden der Markierungsindex und die Markierungsintensität kleiner Lymphozyten und größerer lymphoider Zellen im zirkulierenden Blut und in Lymphknoten während und nach langzeitig wiederholten Injektionen von Thymidin-3H verfolgt. Die radioaktive Vorläufersubstanz wurde in 8stündigen Intervallen über eine Zeitdauer von 30 Tagen intramuskulär verabreicht. Unter der Annahme, daß es bei diesem Verfahren zu keinen nennenswerten radiogenen, pharmakologischen oder hormonalen Störungen kam, erscheinen die nachstehenden Schluß folgerungen gerechtfertigt: 1. Während des ersten Tages der Injektionsperiode wurden im Mittel 18% (Maximum: 29%) unmarkierte kleine Lymphozyten durch markierte ersetzt. Die Markierungsindices dieser Zellart im Blut, als Funktion der Zeit nach Beginn der wiederholten Injektionen von Thymidin-3H, ergaben eine Kurve, die um den 8. Tag herum 50% und nach 30 Tagen 79% (Maximum: 85%) erreicht. 2. Die Resultate lassen sich am ehesten mit der Annahme in Einklang bringen, daß die Häufigkeitsverteilung der verschiedenen Werte für die G 0-Zeit (Erklärung im Text), bzw. Verweiloder Rezirkulationsdauer, der kleinen Lymphozyten im peripheren Blut eine kontinuierliche ist und einen Gipfel bei einem bis mehreren Tagen aufweist. 3. Die größeren lymphoiden Zellen im peripheren Blut wurden in ihrer überwiegenden Mehrzahl wesentlich rascher umgesetzt als die kleinen Lymphozyten. 4. Der Markierungsindex der kleinen Lymphozyten in Lymphknotenausstrichen entsprach am Ende der Injektionsperiode demjenigen im peripheren Blut. Am Ende der Injektionsperiode fanden sich in den äußeren Rindenschichten der Lymphknoten, wo der schwer mobilisierbare Pool von Lymphozyten liegt, mindestens ebenso viele unmarkierte kleine Lymphozyten wie im zirkulierenden Blut. 5. Die Blutmonozyten waren 4 Tage nach Beginn der wiederholten Injektionen von Thymidin-3H zu 100% markiert und behielten diesen Markierungsindex während der restlichen Injektionsperiode bei. Die Befunde werden im Zusammenhang mit Fragen des Proliferationsmodus und der Wanderungsmöglichkeiten der Lymphozyten sowie ungenügender autoradiographischer Wirksamkeit besprochen und mit den von anderen Autoren mitgeteilten Resultaten nach kontinuierlicher intravenöser Infusion von Thymidin-3H verglichen.
    Notes: Summary Young adult female Sprague-Dawley rats were given intramuscular injections of thymidine-3H at 8-hour intervals for a period of 30 days in order to follow the labeling indices and labeling intensities of small lymphocytes and of large lymphoid cells in the circulating blood and lymph nodes. Assuming that radiotoxic, pharmacological and/or hormonal effects were negligible, the following conclusions seem to be justified: 1. During the first day of the injection period the labeling index of small lymphocytes in the peripheral blood rose from zero to an average of 18% (maximum: 29%). Labeling indices of this cell type in the circulating blood, as a function of time after onset of the labeling procedure, followed a curve which reached 50% around day 8 and 79% at the 30 day terminal interval. 2. Results can best be explained by the hypothesis that the frequency distribution of the values for G 0 time or residence (recirculation) time of small lymphocytes in the circulating blood is a continuous one and shows a marked peak from one to a few days. 3. Large lymphoid cells in the peripheral blood were replaced much more rapidly than small lymphocytes. 4. The labeling index of small lymphocytes in lymph node smears at the end of the injection period corresponded to that of small blood lymphocytes. Autoradiographs of histological sections revealed that the outer zones of the lymph node cortex which contains preferentially the more sessile pool of lymphocytes, contained as high a percentage of unlabeled small lymphocytes as did the circulating blood. 5. Blood monocytes were labeled to 100% 4 days after beginning repeated injections of thymidine-3H and maintained this labeling index throughout the labeling period. These results are discussed in respect to the proliferative pattern and migrational behavior of lymphocytes and to the problem of autoradiographic inefficiency. Data are compared to those obtained with continuous intravenous infusion of thymidine-3H.
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    Cell & tissue research 111 (1970), S. 346-363 
    ISSN: 1432-0878
    Keywords: Kidney ; Glomerulus ; Development ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die Differenzierung der Podocyten wurde an Nieren 10 Tage alter Ratten raster-elektronenmikroskopisch untersucht und mit durchstrahlungs-elektronenmikroskopischen Befunden verglichen. Die Podocytenfortsätze können danach auf dreierlei Wegen gebildet werden: 1. Spalten innerhalb des Cytoplasmas lassen bandartige Cytoplasmabrücken entstehen. Diese gliedern sich weiter auf, bis zahlreiche miteinander verzahnte Fortsätze derselben Zelle entstanden sind. 2. Vom Zellrand her werden dicke Fortsätze weit vorgeschoben, die kleinere Fortsätze bilden. Durch sie können Verzahnungen mit entfernten Deckzellen entstehen. Die kleinen Fortsätze können sich jedoch auch mit anderen Fortsätzen der eigenen Zelle verzahnen. 3. Fingerförmige Fortsätze benachbarter Zellen verzahnen sich während ihrer Entstehung miteinander. Trotz zahlreicher desmosomenartiger Haftstellen zwischen benachbarten Podocyten entwickeln sich ihre Fortsätze und deren Verzahnungen anscheinend weitgehend autonom und nur selten nach den vermuteten Regeln epithelialer Nachbarschaft (Typ 3). Die Befunde sprechen vielmehr dafür, daß durchflutete und wachsende Glomerulumkapillaren die Podocytendifferenzierung induzieren und die Orientierung der Fortsätze beeinflussen.
    Notes: Summary The differentiation of the podocytes was studied by scanning electron microscopy on kidneys of 10 days old rats. The results were compared with transmission electron microscopic pictures from the same kidneys. There are three ways of forming processes by the podocytes: 1. Slits within the cytoplasm give rise to cytoplasmic bridges which further divide themselves and finally build up a meshwork of processes within a cell. 2. Thick and sometimes very long processes originate from the cell border. Their smaller branches may interdigitate with those of distant podocytes or with other processes out of the same cell. 3. Finger-like processes of neighbouring cells interdigitate as soon as they develop. In spite of numerous desmosomal structures between neighbouring podocytes the cell processes and their interdigitations develop mostly independently from each other and only seldom after the expected rules of epithelial vicinity (type 3). These findings are interpreted as indication that flooded and growing capillaries induce the differentiation of podocytes and that they influence the orientation of their processes.
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    Cell & tissue research 119 (1971), S. 326-333 
    ISSN: 1432-0878
    Keywords: Median eminence ; Frog ; Serotoninergic nerve fibers ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary For the identification of the nerve fiber containing serotonin (5-hydroxytryptamine) in the frog median eminence, an electron microscopic autoradiography was performed with 5-hydroxytryptophane-3H which is the precursor of serotonin. At 1 and 24 hours after the intraperitoneal injection, most silver grains were located over the nerve fibers and endings, and a few were also found over the glia cell and the perivascular space. A large number of silver grains were located over the type 3 nerve endings (Nakai, 1971) containing small dense granules about 600–1000 Å in diameter 1 and 24 hours after the injection. Some silver grains were localized over the nerve endings containing intermediate-size dense granules 1100–1700 Å in diameter. Silver grains were also frequently observed over the nerve fibers in the inner layer of frog median eminence. There is no significant difference in the pattern of distribution of silver grains between tissues of 1 hour and 24 hours after the injection.
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  • 22
    ISSN: 1432-0878
    Keywords: Chemoreceptor ; Locusta ; Fine structure ; Development ; Moulting
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The basic structure of the terminal sensilla of Locusta migratoria resembles that of Schistocerca gregaria. There are commonly six or ten neurons whose dendrites extend almost to the opening of the peg. Proximally the dendrites are clothed by a neurilemma cell which also encloses a basal cavity through which their ciliary region passes. The tormogen cell encloses the receptor-lymph cavity and actively secretes material into it. The receptor-lymph cavity and the basal cavity are quite separate. The development of new pegs at a moult is described. After apolysis the scolopale extends across the subcuticular space and protects the dendrites, which remain in a functional condition until shortly before ecdysis. As the trichogen cell grows out to form a new peg the tip is surrounded by a mass of electron-dense material, probably derived from the receptorlymph cavity. The function of this material is unknown. Regeneration of the dendrites is considered. The possible mechanism by which the tip of the peg opens and closes is considered and the general structure of the organule is discussed in relation to functioning.
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  • 23
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    Cell & tissue research 131 (1972), S. 287-297 
    ISSN: 1432-0878
    Keywords: Histocytochemistry ; Autoradiography ; Blood vessels ; Lymph nodes ; Intestine, small
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The histochemistry and DNA turnover of postcapillary high-endothelial venules in lymph nodes and Peyer's patches have been investigated. Autoradiographic studies showed that the cells are long lived. They exhibit a distinct metachromatic reaction that is indicative of a moderate amount of RNA. They are PAS positive due to the presence of glycogen. Considerable amounts of mucopolysaccharides are not found inside the cells. The reactions for lactate dehydrogenase, NADH-tetrazolium reductase and unspecific esterase are strong. The intensities of the reactions are comparable to those of the epithelium of the intestinal villus and of reticular cells and definitely stronger than that of other endothelial cells. Tests for acid phosphatase, alkaline phosphatase, succinic dehydrogenase, glucose-6-phosphate dehydrogenase and NADPH-tetrazolium reductase showed that these enzymes are either absent or present in small amounts.
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  • 24
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    Cell & tissue research 135 (1972), S. 1-26 
    ISSN: 1432-0878
    Keywords: Retina ; Hypothalamus (Mammals) ; Suprachiasmatic nucleus ; Neuroendocrinology ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Retino-hypothalamic connections have been studied autoradiographically in the rat, guinea pig, rabbit, cat and monkey following the intravitreal injection of 3H-leucine or 3H-proline, and electron microscopically following unilateral eye removal in the guinea pig and monkey. In each of the species examined evidence has been found for a direct projection from the retina to the suprachiasmatic nucleus, but to no other region of the hypothalamus. The projection to the suprachiasmatic nucleus is always bilateral (even in the albino guinea pig, in which all other components of the retinal projection are crossed) but from grain counts in our autoradiographs it appears that the input to the contralateral nucleus is about twice as heavy as that on the ipsilateral side. Most of the retinal fibers appear to terminate within the ventral part of the nucleus where they form asymmetric synapses either upon small dendritic branches or dendritic spines. The possible role of this retinal projection to the suprachiasmatic nucleus in mediating a variety of light-induced neuroendocrine responses is discussed.
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  • 25
    ISSN: 1432-0878
    Keywords: Subcommissural organ ; Reissner's fibre ; Rana esculenta ; Light/Darkness ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The influence of long daily photoperiods and of continuous darkness on the secretory activity of the subcommissural organ (SCO) and on the growth rate of Reissner's fibre (RF) in Rana esculenta was studied in winter. The amount of aldehyde-fuchsin (AF) positive material in the apical cell parts of the SCO is smaller in light-adapted than in darkness-adapted animals. Differences in incorporation rate of 35S-cysteine between the SCO of light-adapted and of darkness-adapted animals, however, are small. The conclusion must be that light/darkness conditions only slightly influence the secretory activity of the SCO cells of Rana esculenta. In agreement with this conclusion is the observation that RF grew only slightly faster in the light-adapted than in the darkness-adapted animals. Under the conditions used RF was completely renewed in about 3 to 4 days. Influences of temperature on the activity of the SCO have been observed.
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  • 26
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    Cell & tissue research 139 (1973), S. 179-200 
    ISSN: 1432-0878
    Keywords: Retino-preoptic pathway ; Optic tracts ; Rana temporaria ; Light microscopy ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The optic tracts and centres of optic terminals of Rana temporaria have been investigated with silver impregnation techniques after unilaterally cutting the optic nerve and autoradiographically after injection of a mixture of tritiated amino acids into the vitreous body of the left eye. The observations on the course of the optic tracts and on the optic terminals in the thalamus and optic tectum are to a great extent in agreement with those of other authors. The probability of a retino-preoptic pathway is supported by the detection of fibres running in dorsal direction in front of the place where the optic nerve penetrates the brain. In horizontal sections these fibres can be seen deviating from the optic tract, covering a short distance in frontal direction and then turning upward under an angle of about 90 degrees. They disappear between the ventral aldehyde-fuchsin positive cells of the preoptic nucleus. The ventral and median parts of the ipsilateral preoptic nucleus contain fragments of degenerated fibres. Autoradiographic data are also in favour of the presence of an ipsilateral retino-preoptic tract. After carefully counting the number of grains over left and right preoptic nucleus, it appeared that over the ventral and median parts of the left preoptic nucleus more grains occur than over the identical areas of the right one.
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  • 27
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    Cell & tissue research 136 (1973), S. 355-364 
    ISSN: 1432-0878
    Keywords: Hypothalamo-hypophysial system ; Rana temporaria ; Blinding ; Illumination ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The influence of a long daily photoperiod and continuous darkness on the hypothalamo-hypophysial system of blinded frogs was studied. In the preoptic nucleus no difference could be observed between the two groups of blinded frogs neither in the amount of incorporated 35S-cysteine nor in the amount of aldehydefuchsin positive material nor in the nuclear volume of the secretory cells. These results were compared with those of an experiment with intact frogs kept simultaneously under the same environmental conditions. It appeared that the activity of the dark-treated blinded group was enhanced compared with the activity of the dark-treated intact group while the light-treated blinded frogs showed a decrease in activity compared with the similarly treated intact animals. Likewise the influence of a long daily photoperiod on the hypothalamo-hypophysial system of unilaterally blinded frogs was studied. The activity of the preoptic nucleus was lower on the side where the optic nerve had been cut than on the intact side. In the dorsal part of the preoptic nucleus a difference between the two sides could not be observed. The significance of these results is discussed with regards to a possible connection between retina and preoptic nucleus.
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  • 28
    ISSN: 1432-0878
    Keywords: Neurosecretion ; Annelida ; Sexuality and Development ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Während der sexuellen Entwicklung vonPlatynereis dumerilii steigt die Zahl der Neurone, die Merkmale einer sekretorischen Aktivität aufweisen, parallel zum Wachstum und zur Reifung der Keimzelle an. Die cytologische Differenzierung eines Neurons zur neurosekretorischen Zelle ist mit einer Steigerung der Synthese Cystin-haltigen Materials gegenüber konventionellen Neuronen gekoppelt. Neurosekretorische Zellen treten erstmals in Erscheinung, kurz bevor die Oocyten in die zweite Oogeniephase eintreten, während der die Vitellogenese abläuft. Aufgetragen gegen den Oocytendurchmesser ergibt die Zahl der Neurone, die sekretorisch aktiv werden und3H-Cystin inkorporieren, eine ansteigende Kurve. Die Kurve biegt auf ein Plateau, wenn die Oocyten eine kritische Größe erreichen. Diese Größe markiert jenes Entwicklungsstadium, von dem ab eine Enthirnung eine normale Reifung nicht mehr verhindert. Die Zahl synthetisch tätiger Neurone steight erneut an, wenn die Oocyten die kortikale Struktur des reifen Eies entwickeln. Das Maximum wird kurz vor der Metamorphose erreicht. Während der epitoken Umwandlung sinkt die synthetische Aktivität rasch ab, um im schwärmbereiten Tier gänzlich zum Stillstand zu kommen. In Tieren, die nach der kritischen Phase zur caudalen Regeneration veranlaßt werden, fällt die Zahl markierter neurosekretorischer Zellen auf ein Niveau ab, das für junge, „vorkritische“ Individuen charakteristisch ist. Entsprechend wird in jungen, vorkritischen Tieren, die erst wenige endokrine Neurone besitzen, die Differenzierung weiterer neurosekretorischer Zellen durch eine Regeneration nicht stimuliert. Der zeitliche Verlauf der synthetischen Aktivität im Zuge der Entwicklung und die durch eine Regeneration erzwungenen Veränderungen sind somit reziprok zur Aktivität des Gehirns in Bezug auf die Ausschüttung des Juvenilhormons. Die Hypothese wird zur Diskussion gestellt, die sinkende Produktion des Juvenilhormons werde von der steigenden Produktion eines antagonistischen neuroendokrinen Prinzips begleitet oder verursacht.
    Notes: Summary During sexual development ofPlatynereis dumerilii, the number of neurones exhibiting secretory activity rises in parallel with the growth and maturation of the germ cells. The cytological differentiation of neuroglandular properties is accompanied with an increased uptake of tritiated cystine. The first neurones developing the characteristics of secretory cells and incorporating cystine appear just before the oocytes enter the second growth phase which corresponds with vitellogenesis. When plotted against the oocyte diameter the number of labelled neurosecretory cells yields an ascending line, which becomes a plateau once the oocytes approach a critical size. This critical size defines the developmental stage beyond which decerebration does not prevent normal maturation. The neuronal synthetic activity rises again when the oocytes differentiate the cortical structure of ripe eggs. The curve displays its maximum slope at the onset of metamorphosis. During the epitokous transformation the synthetic activity decreases rapidly and is almost totally depressed when swarming is imminent. In animals induced to regenerate their posterior segments after they have passed the critical stage, the number of labelled neurosecretory cells becomes reduced to the precritical level. According to this, regeneration in young precritical animals containing only few endocrine neurones does not stimulate the development of further secretory neurones. Thus, the time course during maturation and the changes caused by regeneration are reciprocal to the activity of the brain with respect to the release of juvenile hormone. The question is thus raised as to whether the declining titer of juvenile hormone may be accompanied or caused by an increased production of an antagonistic principle related to maturation.
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  • 29
    ISSN: 1432-0878
    Keywords: Nervous system ; Stick insect ; Blood-brain barrier ; Development ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fat body sheath which surrounds the ventral nerve cord of the adult stick insect, Carausius morosus, is absent in the hatchling. Since the haemolymph sodium ion compositions of the two stages are similar, it is suggested that the fat body sheath is not a site of a blood-brain barrier dealing with extra-axonal regulation of sodium. Similarities of ultrastructure in connectives of adults and hatchlings are demonstrated, and tight junctions are shown to occur in perineural cells of both stages. The possible significance of this to the blood-brain barrier of this insect is discussed.
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  • 30
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    Cell & tissue research 106 (1970), S. 348-370 
    ISSN: 1432-0878
    Keywords: Ovary ; Insect ; Chironomus ; Development ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Im Ovar von Chironomus sind in Phase 1 des 4. Larvenstadiums polygonal abgeflachte „Innenzellen“ von kleineren „Außenzellen“ umgeben, die Bakteroide und Phagosomen enthalten; zwischen den Innenzellen liegen unregelmäßige Zelltrümmer („keimbahnbegleitende Substanzen“). Zu Beginn der Ovariolenbildung werden in Phase 3 durch Spalträume zwei Schichten der Außenzellen voneinander getrennt, von denen die innere (Follikel- und Eikanalepithel) regelmäßige Buchten bildet. In diese Buchten wandern von innen Zellpaare ein, die an „synaptischen Komplexen“ bzw. multiplen Chromatinstrukturen als Ei- und Nährzellen kenntlich sind. Zwischen beiden Zellen sind „Fusome“ häufig, die später in eigentümlicher Weise geschlossen werden. Zwischen den Eikanalzellen entsteht in Phase 5 durch Spaltbildung der Eikanal; in Phase 7 sind die Eikanalzellen auffallend glykogenreich. Kurz vor der Vitellogenese treten im Bereich der Oocyte Membransysteme und „annulated lamellae“ auf; akzessorische Kerne werden als Ausstülpungen des Oocytenkernes gebildet und später abgeschnürt. In Phase 9 sind an der Peripherie der Eizelle Mikrovillisäume und Pinocytosebläschen sichtbar. Die distalen Zellen der Ovariole haben Eioder Nährzellcharakter, sind aber bei Ch. melanotus nicht von Follikelzellen umgeben und werden beim weiteren Ovariolenwachstum reduziert. Trotz extrem geringer Nährzellzahl der Follikel scheint das Chironomus-Ovar funktionell nicht von anderen polytroph meroistischen Insektenovarien unterschieden.
    Notes: Summary In the ovary of Chironomus during phase 1 of the fourth larval instar, polygonally flattened “inner cells” are surrounded by smaller “outer cells” which contain bacteroids and phagosomes. Irregular cell remnants (“germ line accompanying substances”) lie among the inner cells. At the beginning of ovariole formation in phase 3, two layers of outer cells are separated by the formation of fissures. The inner layer of these cells (follicle- and egg-passage epithelium) forms regular invaginations. Cell pairs, identified as oocytes and nurse cells by “synaptic complexes” or multiple chromatin structures, wander from inside into the invaginations. Frequently between the two cells are fusomes, which later close in a characteristic manner. During phase 5, an egg passage is formed as a fissure among the egg-passage cells. During phase 7, the egg passage cells are conspicuously full of glycogen. Shortly before vitellogenesis membrane systems and annulated lamellae appear in the region of the oocyte. Accessory nuclei are formed by a “tieing-off” of projections of the the oocyte nucleus. During phase 9, microvilli and pinocytotic vesicles can be seen at the periphery of the oocyte. The distal cells of the ovariole are of oocyte or nurse cell nature, but in Ch. melanotus they are not surrounded by follicle cells and are reduced during further ovariole growth. In spite of the extremely small number of nurse cells in the follicle, the Chironomus ovary apparently does not differ functionally from other polytrophic meroistic insect ovaries.
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  • 31
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    Cell & tissue research 146 (1973), S. 491-500 
    ISSN: 1432-0878
    Keywords: Hypothalamo-hypophysial system ; Pineal complex ; Rana esculenta ; Light/darkness ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary InRana esculenta the activity of the hypothalamo-hypophysial system has been investigated in intact and blinded animals, after removal of the frontal organ and after elimination of the whole pineal complex. The results on intact and blinded animals are practically the same as those found earlier inRana temporaria. Light increases the activity of the preoptic nucleus, blinding changes the difference between light- and darkness-treated intact animals. Compared with the intact animals the other two groups (without frontal organ and without pineal complex) show a marked increase in incorporation of35S-cysteine in the preoptic nucleus. A difference between the animals without frontal organ and those without pineal complex, however, can hardly be observed. It follows that the absence of the frontal organ has the same influence on the preoptic nucleus as elimination of the whole pineal complex. In intact animals the influence of the frontal organ on the preoptic nucleus consists of an inhibition of neurosecretory activity as well under light as under darkness conditions. The enhanced synthesis of labelled material in the preoptic nucleus after removal of the frontal organ, results in a transport along the hypothalamo-hypophysial tract mainly to the outer zone of the median eminence and not to the posterior lobe.
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  • 32
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    Cell & tissue research 147 (1973), S. 75-85 
    ISSN: 1432-0878
    Keywords: Skeletal muscle ; Denervation ; Development ; Fiber types, myofibrils ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ultrastructural diversification of muscle fibers, with regard particularly to myofibrillar changes, has been investigated in the fast-twitch extensor digitorum longus (EDL) and the slow-twitch soleus muscles of the rat during fetal and postnatal development in the presence and in the absence of motor innervation. The band pattern and the shape of the myofibrils were uniform in fetal and neonatal muscle fibers and underwent differential changes during the first weeks after birth, concomitantly with fiber type specialization. The most evident variations in myofibrillar structure arising in this period concern the thickness of the Z band and the arrangement of the myofibrils. Myofibril formation was at first not impaired by denervation of rat muscles performed in utero and, although focal disintegration of myofibrils and detachment and loss of orientation of filaments became apparent by one week, atrophic muscle fibers with well-organized myofibrils could be seen as late as 2 months after birth. However, denervated muscle fibers of EDL and soleus did not display any significant and consistent difference in myofibrillar band pattern and shape. No variation in mitochondrial content and sarcoplasmic reticulum development was likewise seen in muscle fibers of EDL and soleus after fetal denervation. The findings emphasize the importance of neuromuscular interactions in muscle differentiation.
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  • 33
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    Cell & tissue research 147 (1974), S. 325-334 
    ISSN: 1432-0878
    Keywords: Chordotonal (Tracheal) organ ; Teleogryllus commodus (Orthoptera) ; Hearing ; Development ; Structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The tracheal organ of the mesothoracic tibia of Teleogryllus is located in a corresponding position to the tympanal organ of the prothoracic tibia. The mesothoracic organ contains an average of only 12 scolopidia, the location of which corresponds to that of the proximal group A and proximal main group in the prothoracid tympanal organ. There are no scolopidia corresponding to the distal group of the tympanal organ. The variability in number of scolopidia is much greater in the mesothoracic organ than in the prothoracic organ. The adult tracheal system of the mesothoracic leg resembles the early nymphal tracheal system in both pro- and meso-thoracic legs. The development of the tracheal organ is usually complete by the sixth instar. The mesothoracic tracheal organ of the adult is broadly equivalent to the prothoracic tympanal organ of a fifth instar animal.
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  • 34
    ISSN: 1432-0878
    Keywords: Protein secretion ; Defensive glands ; Blatta orientalis ; Cytology ; Autoradiography ; Insekts
    Source: Springer Online Journal Archives 1860-2000
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    Description / Table of Contents: Zusammenfassung Im Bereich der abdominalen Tergite V-X und oberseits and den Zerzi liegt bei Nymphen beider Geschlechter und bei adulten Weibchen von Blatta orientalis statt des einschichtigen Epithels ein zweischichtiges Drüsengewebe vor, welches ein visköses Sekret aus Wasser, freien Aminosäuren (+ Glutamin), Oligo- und zahlreichen Polypeptiden auf die Tergitenoberfläche sezerniert. Die strukturelle Differenzierung des Drüsengewebes ist mit der Sekretionsaktivität korreliert, sowohl während der Ontogenese als auch im Bereich verschiedener Tergite (Maxima: weibliche Subimagines, Tergite VI und VII). Untersuchungen mittels hochauflösender quantitativer Autoradiographie ergaben, daß injizierte Aminosäuren im größten Teil der Drüsenzellen angereichert werden: Markierte Zellen zeigen Radioaktivität im reichlich ausgebildeten rauhen endoplasmatischen Retikulum, Golgi-Apparat, in Sekretgranula und in ihrem Endapparat. Dieser durchsetzt die Drüsenzelle als langer gewundener Kanal mit Bürstensaum, in welchen je eine darüberliegende Gangzelle einen chitinösen Ausführgang inseriert. Die gleichzeitige Anwesenheit von markierten und nicht markierten Zellen mit praktisch gleich stark entwickeltem endoplasmatischem Retikulum und Golgi-Apparat zeigt, daß die morphologische Ausbildung dieser mit der Proteinsekretion befaßten Organellen nicht unbedingt deren Aktivität reflektiert. Vereinzelt stehen Zellfortsätze mit den morphologischen Charakteristika neurosekretorischer Tätigkeit in direktem Kontakt mit Drüsenzellen. Eine Abwehrfunktion des viskösen Sekrets durch bloße mechanische Behinderung kleiner räuberischer Arthropoden wurde sichergestellt, wobei es dem Beutetier gelingt, zu flüchten. Weiters wurde ein zweiter Drüsenzelltyp beobachtet, der mit injizierten Aminosäuren nur schwach markierbar ist, ebenfalls einen Endapparat besitzt, jedoch arm an rauhem endoplasmatischem Retikulum und gleichzeitig reich an Mitochondrien, Golgi-Apparaten und kleinen Vesikeln ist. Die Funktion dieses zweiten Zelltyps ist zwar nicht sichergestellt, möglicherweise reguliert er jedoch die funktionell wichtige Viskosität des Sekretes.
    Notes: Summary A two-layered glandular tissue occurs on tergites V to X and on the cerci of juvenile specimens of both sexes and of adult females of Blatta orientalis, in place of the usual monolayer of epidermal cells. This gland tissue contains two cell types and secretes a viscous product of water, free amino acids (+ glutamine), oligo- and several polypeptides onto the tergal surface. The structural differentiation of the gland is correlated with secretory activity, both in different molting stages and in different tergites of an individual; maximal values are found in tergites VI und VII on last instar females. Applying quantitative radioautography on the electron microscope level, we found, that although the most common gland cell type contained an abundantly developed rough endoplasmic reticulum and Golgi-apparatus, characteristic of protein secreting cells, not all of them incorporated equally the injected amino acids. This is consistent with an asynchronous secretory cycle, also suggested by biochemical studies. Of great significance is the demonstration that the fine structural elaboration of the cellular organelles involved in protein synthesis cannot be used as a criterion for their ongoing activity. The secretion is discharged into an end-apparatus consisting of a tortuous canal with a brushborder that penetrates the whole gland cell. One unbranched chitinous duct, formed by a “duct carrying cell”, is inserted into the end-apparatus of each gland cell. Occasionally, cell processes exhibiting the typical morphological characteristics of neurosecretory cells are seen in direct contact with gland cells. A defensive function of the secretion which acts by mechanically impairing smaller predatory arthropods was ascertained. To achieve this effect and to allow the preyanimal to escape, the secretion has to be adjusted to a proper viscosity by an adequate dilution. This might be achieved by the second gland cell type, which was not selectively labelled by injected amino acids; this cell type contains an endapparatus, abundant mitochondria, Golgi-apparatuses and small vesicles, but only few profiles of rough endoplasmic reticulum.
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  • 35
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    Cell & tissue research 148 (1974), S. 535-550 
    ISSN: 1432-0878
    Keywords: Synaptosomes ; Rat brain stem ; Synaptogenesis ; Development ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure and protein content of the five subfractions of the crude mitochondrial fraction from the brain stem of the 1-day old and adult rat was examined. The morphological composition of the subfractions after fixation in glutaraldehyde and osmiumtetroxide in the adult rat brain stem resembled that previously reported for the whole brain; synaptosomes sedimented in a sucrose gradient in subfractions C and D. In the 1-day old rat, mature synaptosomes were found in subfractions A, B, C and D; E contained mainly free mitochondria. 80–95% of the processes in the adult and 10–30% in the 1-day old rat contained synaptic vesicles which were of four types: (1) small agranular vesicles (2) large dense core vesicles (3) large agranular vesicles (4) coated vesicles. Pre- and postsynaptic membrane thickenings were demonstrated in many nerve-ending particles. In the subfractions of the 1-day old rat the protein content was one half and the distribution resembled that in the adult. Evidently nerve endings develop faster in the brain stem than in cortical areas; a serotoninor adrenergic origin of the early synaptosomes is suggested.
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  • 36
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    Cell & tissue research 125 (1972), S. 306-331 
    ISSN: 1432-0878
    Keywords: Parenchyma of organs ; Rats ; Regeneration ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die sowohl nach singulärer 3H-Thymidin-Injektion als auch nach kontinuierlicher 3H-Thymidin-Dauerinfusion an Ratten erhobenen autoradiographischen Befunde lassen folgende Schlüsse ziehen: 1. Die während des Wachstums im Vergleich zum Ende der Foetalperiode ganz auffällige, unmittelbar postpartal nachweisbare Depression des 3H-Thymidin-Markierungs-Index im Parenchym von Leber, Niere und Pankreas wird auf eine funktionelle Umstellung und zumindest in der Leber auch auf eine strukturelle Umgestaltung bezogen. Schon am 30. Tag ergeben sich Anhaltspunkte für eine Umschaltung auf einen langsamen Proliferationsmodus, die bei 60 und 120 Tagen mit Halbierung der DNS-Syntheserate vollends abgeschlossen ist. 2. In der kompensatorisch regenerierenden Leber nach 2/3-Teilhepatektomie wird der Anteil nicht proliferierender Zellen — d.h. die non growth fraction — von juvenilen über eben ausgewachsene bis zu senilen Tieren kontinuierlich größer. 3. Bei der reparativen Regeneration in der unterbundenen Niere nach temporärer 1stündiger Ischämie ist der Proliferationsumfang in den am stärksten geschädigten Nephronabschnitten auch am größten. Es führt das Stratum subcorticale, dann folgt die Zona intermedia, das Stratum labyrinthicum und die Zona basalis. 4. Demgegenüber weist die Topik proliferierender Zellen bei kompensatorischer Nierenregeneration nach kontralateraler Ischämie bzw. Nephrektomie wohl quantitative aber keine qualitativen Unterschiede zu der beim physiologischen Zellersatz von Kontrollen auf. Das Stratum labyrinthicum zeigt die höchsten Werte und dann stellt sich eine stufenweise erfolgende Abnahme der prozentualen Markierung über das Stratum subcorticale zur Zona intermedia und Zona basalis ein. 5. Anhand der autoradiographischen Daten wird ein Modell für die Proliferation von Leberepithelien juveniler und ausgewachsener Ratten entworfen. Weiter befaßt sich dieses Modell mit der Zellneubildung nach Teilhepatektomie im Verlauf und nach Abschluß der Regeneration. Nach den entwickelten Vorstellungen wirkt eine partielle Hepatektomie an ausgewachsenen und senilen Tieren durch Verkleinerung der non growth fraction und Vergrößerung des proliferating pools im Sinne einer Verjüngerung der proliferatorischen Potenz des Leberepithels.
    Notes: Summary The autoradiographic results reported, are obtained on rats after single injections of 3H-thymidine as well as continuous 3H-thymidine infusions. They lead to the following conclusions: 1. Compared to the end of embryonic development the 3H-labelling index in parenchyma of liver (epithelium), kidney (tubule), and exocrine pancreas (acinus) is depressed during the first day of postnatal growth. From 1–4 days postpartal fluctuations occur, afterwards the labelling index increases between 7 and 12 days and from there on a decrease is observed up to 120 days. This depression and fluctuation of the labelling index is probably connected with a functional transposition and, especially in the liver, with a structural transformation. The reduction of the mean grain density of labelled nuclei by about a factor of 2, begins already at day 30 and is completed on day 60 and 120. It depends on a reduction of the rate of DNA synthesis. This might be explained as a consequence of a commutation from the rapid to the slow mode of cellular proliferation. 2. In the compensatory regenerating liver after 2/3 partial hepatectomy the portion of non labelled nuclei—i.e. the non growth fraction—increases continuously from juvenile to young adult and especially up to senile animals after a postoperative continuous 3H-thymidine infusion. 3. During reparative regeneration in the ligatured kidney following temporal (1 h) ischaemia the extent of proliferation after postoperative continuous 3H-thymidine infusion is hightest in those regions of the nephron with the largest postischaemic damage. The percentage of labelled nuclei decreases from the stratum subcorticale to the zona intermedia, stratum labyrinthicum, and zona basalis. 4. On the other hand only quantitative but not qualitative differences exist in the topic of proliferating cells between compensatory regeneration in the unligaturated kidney after contralateral temporal ischaemia or nephrectomy and the physiological cell renewal of controls. After continuous 3H-thymidine infusions the highest percentage of labelled cells is observed within the stratum labyrinthicum and then a gradual decrease occurs from there to the stratum subcorticale, zona intermedia and basalis. Thus, cellular proliferation in compensatory regeneration of the kidney is only an enhanced form of those proliferative processes occuring during physiological cell renewal. 5. With the autoradiographic data a model concerning proliferation of liver epithelia in juvenile and adult rats has been constructed. Furthermore this model deals with cell renewal during and after regeneration following partial hepatectomy. The conclusion is, that partial hepatectomy diminishes the non growth fraction and enlarges the proliferating pool. Thus this operation acts as a rejuvenating process in the proliferating potency of liver epithelia.
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  • 37
    ISSN: 1432-0878
    Keywords: Sea anemone mesoglea ; Collagen synthesis ; Epitheliomuscular cells ; Electron microscopy ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Electron microscopy and autoradiography (H3-proline) were used to determine the cell(s) responsible for collagen synthesis and lamination in the mesoglea of the sea anemone, Aiptasia diaphana. Mesogleal collagen is synthesized by the epidermal epitheliomuscular cells which contain much rough endoplasmic reticulum, and secretory vesicles attached to microtubules which cross the basal plasmalemma and anchor in the basement membrane; these cells incorporate large amounts of H3-proline. The mesogleal collagen fibers are non-striated, have clear centers, and a diameter of 200–260 Å; their walls are composed of 65 Å diameter subunit fibrils which appear to be helically oriented. Epitheliomuscular cells rest upon a subepidermal basement membrane which is composed of mesogleal collagen fibers, 65 Å subunit fibrils, and dense granules. This subepidermal basement membrane labels definitively with H3-proline, and is the region where soluble collagen precursors apparently form subunit fibrils which associate to yield mesogleal fibers. The columnar mesogleal collagen fibers are arranged to form layers: the fibers of each layer have the same longitudinal orientation, while those of adjacent layers display an approximate orthogonal arrangement. It is felt that the subepidermal basement membrane is responsible for this organization of mesogleal fibers. Mesogleal amoebocytes do not label with H3-proline and show no ultrastructural evidence of collagen secretion.
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  • 38
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    Cell & tissue research 144 (1973), S. 435-452 
    ISSN: 1432-0878
    Keywords: Muscle spindles ; Intrafusal fibre types ; Development ; Deefferentation ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Muscle spindles of limb muscles were deefferented in neonatal rats by sectioning ventral roots or by removal of the lumbosacral spinal cord. Ten to 56 days after the operation, muscle spindles were examined in the medial gastrocnemius, extensor digitorum longus and soleus muscles. The differentiation of muscle spindles was not affected by deefferentation. The number of spindles in the investigated muscles was not reduced. Intrafusal fibres increased in number from two at birth to four per spindle on the average, as in normal muscles. The characteristic ultrastructural distinctions of nuclear bag and nuclear chain fibres developed as under normal conditions. However, intrafusal fibres atrophied slowly after fusimotor denervation, their polar zones becoming reduced in diameter by about 25% in comparison with control fibre diameters. Spindle capsules, on the other hand, increased in size and attained diameters comparable with normal spindles, appearing even somewhat distended. As intrafusal fibres degenerate after complete denervation at birth (Zelená, 1957), but differentiate in the absence of fusimotor innervation, it can be concluded that sensory nerve terminals induce and support their development. It is assumed that the morphogenetic influence of sensory terminals is mediated by release and uptake of a trophic substance at the synaptic junction. The occurrence of light and dense core vesicles in the sensory terminals and of coated invaginations and vesicles at both the axonal and plasma membrane speak in favour of such a possibility.
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  • 39
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    Cell & tissue research 150 (1974), S. 425-442 
    ISSN: 1432-0878
    Keywords: Glandula submandibularis (Mouse) ; Acinar ultrastructure ; Cell types ; Development ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The development of the submandibular gland of the mouse was studied by means of electron microscopy, from the 14th day of gestation up to birth. In the first two days the acini are solid and their cells contain polyribosomes and a few lamellae of endoplasmic reticulum. Beginning with the 16th day secretory granules appear and rapidly fill an increasing number of cells. The different electron density of the granules makes it possible to distinguish 1. two types of granules, dense and pale, and sometimes intermediate ones, 2. “polymorphic” granules. The latter consists of electron dense and electron pale parts combined in different configurations. The possible significance of the various types of granules is discussed.
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  • 40
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    Cell & tissue research 151 (1974), S. 281-292 
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Mitochondria ; ACTH ; DNA-synthesis ; Autoradiography ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects of a chronic ACTH administration (up to 12 consecutive days) on the 3H-thymidine uptake by the mitochondrial compartment of rat adrenal zona fasciculata were investigated by high resolution autoradiography, and compared with the changes in volume and number per cell of these organelles induced by the hormonal treatment. Up to the 9th day of treatment there is a significant increase in the tracer incorporation into adrenocortical mitochondria which is coupled with a significant increase in the volume of the organelles. After 12 days of hormone administration a significant decrease in the 3H-thymidine mitochondrial uptake is found, which is associated with a conspicuous increase in the number of mitochondria per cell and a net decrease in their average volume. The data are discussed in the light of evidence indicating that mitochondria possess a genetic apparatus largely independent of nuclear control. It is hypothesized that ACTH controls the growth and proliferation of adrenocortical mitochondria and that the mechanism of this action of ACTH involves stimulation of the mitochondrial DNA synthesis.
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  • 41
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    Cell & tissue research 151 (1974), S. 433-456 
    ISSN: 1432-0878
    Keywords: Juxtaglomerular apparatus (Rat) ; Development ; Renin ; Pools ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die perinatale Entwicklung des juxtaglomerulären Apparates, insbesondere das Verhalten der epitheloiden Zellen wurde an 18 trächtigen Ratten and 65 Embryonen bzw. Jungtieren elektronenmikroskopisch untersucht. Parallel dazu wurde die Reninkonzentration bzw. der Reningehalt bestimmt. Spezifische Sekretgranula finden sich erstmals am 18. Tag der Fetalzeit, und zwar in den epitheloiden Zellen des juxtaglomerulären Apparates juxtamedullärer Nephrone. Die Granula machen einen Struktur- und wahrscheinlich auch Funktionswandel durch, der eine Einteilung in drei verschiedene Granulatypen nahelegt. Diesen drei Typen spezifischer (reninhaltiger) Sekretgranula werden die Lysosomen als unspezifische Einschlüsse der epitheloiden Zellen gegenübergestellt. Im einzelnen kommt es während der perinatalen Phase in den fetalen Epitheloidzellen zuerst, d.h. pränatal, zu einer Hypertrophie des rauhwandigen endoplasmatischen Retikulums und des Golgi-Apparates. Hierin sehen die Autoren einen Hinweis auf eine erhöhte Proteinsynthese mit entsprechender Zunahme der Transport- und Konzentrationsvorgänge. Nach der Geburt findet sich dann auch eine deutliche Zunahme der Sekretgranula vom Typ III, die als reife Reningranula (mature granules) angesehen werden. Die bisher noch nicht beschriebenen kleinen Sekretgranula vom Typ I dagegen kommen in weniger entwickelten Epitheloidzellen häufiger vor. Bestimmungen der Reninverteilung zwischen Zytoplasma und den durch Differential-zentrifugation gewonnenen Granula-Fraktionen ergeben auffallende Parallelen zu den morphologischen Befunden. Diese sprechen im allgemeinen dafür, daß “freies Renin” im Ergasto-plasma und “gebundenes Renin” in den Sekretgranula vorliegt. Mit zunehmendem Alter scheint es außerdem — parallel zur relativen Abnahme des Ergastoplasmas und Zunahme der reifen Reningranula — zu einer Verminderung des extragranulären zugunsten des granulär gebundenen Renins zu kommen.
    Notes: Summary The perinatal development of the Juxtaglomerular apparatus (JGA), with particular reference to the epithelioid cells, was studied. Electron microscopic studies were carried out on 18 gravid rats and 65 embryos with corresponding determinations of renin concentration and the renin contents by bio-assay. Specific secretory granules of the epithelioid cells of the JGA of juxtamedullary nephrons are first observed on the 18th day of gestation. The classification into three types of secretory granules suggests that they undergo a structural and probably also a functional transformation. All three types of secretory granule may be regarded as specific, renin-containing, cytoplasmic organelles. During the last days of gestation, the rough-surfaced endoplasmic reticulum and the Golgi apparatus become hypertrophied in epithelioid cells, indicating an increased protein synthesis as well as transport and concentration processes. After birth, there is a definite increase in the number of Type III secretory granules-which may be regarded as mature granules. The small Type I secretory granulesnot previously described-are found more frequently in the immature epithelioid cells. Determinations of the renin distribution in the plasma and in fractions of cytoplasmic constituents (total homogenate, secretory granules) prepared by differential centrifugation showed striking congruence with the morphological findings. It is generally assumed that “soluble renin” occurs in the endoplasmic reticulum and “bound renin” in secretory granules. A shift from extragranular to granular (bound) renin, occurs with increasing age, having its morphological equivalent in the relative decrease of the endoplasmic reticulum and increase in mature secretory granules.
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  • 42
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    Cell & tissue research 152 (1974), S. 299-303 
    ISSN: 1432-0878
    Keywords: Post-capillary venules ; Mice ; Pathway of B lymphocytes ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Histological observation on the mesenteric lymph node and Peyer's patches of C3H B mice, neonatally thymectomized, lethally irradiated and reconstituted with syngeneic bone marrow cells, showed that a large number of lymphocytes appeared selectively in the restricted territory surrounding the post-capillary venules. Severe depletion of lymphocytes persisted in most of the thymus-dependent areas. Lymphocytes were also observed passing through the walls of the post-capillary venules. Autoradiographic studies on the mesenteric lymph node of recipient B mice 30 minutes after intravenous injection of cells labelled with 3H-uridine and taken from lymph nodes of donor B mice showed that B lymphocytes could penetrate the walls of the post-capillary venules from the blood into the peripheral lymphoid tissues. The post-capillary venules, which are known as the recirculating route of T lymphocytes in normal animals, are thought to be the pathway of migrating B lymphocytes in B mice.
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  • 43
    ISSN: 1432-0878
    Keywords: Hypothalamic neurosecretory system (rat) ; Adrenal cortex ; 35S-cysteine incorporation ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The incorporation of 35S-labelled cysteine in the hypothalamic-neurohypophyseal system was studied in normal and adrenalectomized rats and in rats treated with excess hydrocortisone. Labelled cysteine was intraperitoneally administered and grain counts were made of autoradiographs produced from sections of the supraoptic and paraventricular nucleus, median eminence and neurohypophysis of animals killed 45 min., 4 hours and 24 hours after administration of the labelled substance. On the whole, lower incorporation levels of the label were noted in the adrenalectomized rats, compared with the controls. In the rats treated with excess hydrocortisone, the grain counts at 45 min and 4 hours after injection were higher and those at 24 hours were lower than those of the controls. The findings are discussed, among other things, in terms of rate of uptake vs. time and related to previous reports on the cysteine uptake and neurosecretory activity of the hypothalamic-neurosecretory sytem.
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  • 44
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    Cell & tissue research 153 (1974), S. 115-136 
    ISSN: 1432-0878
    Keywords: Muscle spindles ; Intrafusal fibre types ; Development ; De-efferentation ; Utrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Hind limb muscles were de-efferented in 19 new-born rats by removal of the lumbosacral spinal cord, with preservation of spinal ganglia and their peripheral branches. The juxtaequatorial and polar zones of muscle spindles were studied in different leg muscles 3 to 9 weeks after the operation in order to establish whether intrafusal fibre types would become differentiated after permanent motor denervation. De-efferented intrafusal fibres developed into distinct ultrastructural fibre types similar to those found in control muscles. The nuclear bag type had confluent myofibrils with ill-defined M lines and relatively few mitochondria. The nuclear chain type had discrete myofibrils with prominent M lines, numerous large mitochondria and a more developed sarcotubular system. The fibre type characteristics were sometimes blurred by disarranged cross striation, but they were clearly discernible in 59 out of 69 de-efferented fibres of 31 spindles investigated in the electron microscope. A sample of 220 de-efferented spindles from leg muscles of 6 rats was examined in the light microscope on transverse sections stained for ATPase activity. The difference in the ATPase activity among intrafusal fibre types was marked in about 70% spindles; in contrast to this, no distinct fibre types could be discerned in the population of extrafusal fibres which were stained rather uniformly. In de—efferented spindles-as in normal control spindlesnuclear chain fibres always exhibited high ATPase activity, whereas one of the nuclear bag fibres had low ATPase and the other either low or medium to high ATPase activity. However, the ATPase activity of de-efferented muscles was generally lower than that of normal muscles. It can be concluded that intrafusal fibres do acquire their fibre type characteristics after fusimotor denervation despite complete deprivation of nerve impulse activity during the postnatal period when intrafusal fibre types differentiate in normal spindles.
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  • 45
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    Cell & tissue research 153 (1974), S. 399-413 
    ISSN: 1432-0878
    Keywords: Spinal ganglia (Rat) ; Cell division ; Autoradiography ; Neurone morphogenesis ; Light and electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Pulse labelling with tritiated thymidine was used to determine the time of the final division of the neuroblasts which subsequently form rat lumbar dorsal root ganglion neurones. The final division occurred during a 4 day period, the maximum frequency being on day 12 of gestation. Separation of the ganglion cells into large light neurones and small dark neurones showed that the large light neurones were formed earlier than the small dark neurones. In both cases the final divisions occurred over a period of 3–4 days, but the peak rate of formation of large neurones was on day 12, and that of the small neurones was on day 13. Low power electron micrographs were used to measure mean cell diameter throughout development from day 11 of gestation until a postnatal age of 225 days. A marked increase in cell diameter occurred on day 15–15.5, about 3 days after the final cell divisions of the majority of the cells. The rate of growth increased just before birth, but no increase in mean cell diameter was found between day 21 of gestation and the third day postnatal. The growth was again rapid after this period until a plateau in cell diameter was reached about 33 days after birth.
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  • 46
    ISSN: 1432-0878
    Keywords: Protonephridium ; Pomatoceros triqueter (Annelida, Polychaeta, Sedenta-ria) ; Terminal cell ; Channel cell ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary During the development of the intermediate and late gastrula of Pomatoceros triqueter, the terminal and channel cells grow towards each other and form the protonephridium. They interdigitate through lateral microvilli. The junctions between the cells form filtration clefts, which are bridged by fibrils.
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  • 47
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    Cell & tissue research 137 (1973), S. 251-269 
    ISSN: 1432-0878
    Keywords: Synapse ; Development ; Spinal cord ; Amphibian
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary An electron microscopical study has been made of the cervical spinal cord of Xenopus laevis embryos, from the time that the neural tube closes until the larvae were hatched and could swim. Sections of the whole cord were searched for intercellular junctions during this period. Two nonsynaptic types were found, the first were widely distributed puncta adherentia, the second were rare and similar to “gap” junctions. Membrane specializations with synaptic vesicles were first found when the neural folds had fused; “membrane-vesicle clusters” which looked like the presynaptic half of a synaptic junction were present, together with synaptic junctions lacking any postsynaptic membrane thickening or cytoplasm density. About four hours later, mature synaptic junctions with full thickening of the postsynaptic membrane, dense cytoplasm and striated or dense material in the synaptic cleft were present. Presynaptic mitochondria, dense-cored and flattened vesicles, fibre to fibre and fibre to cell body synapses were present from the first, as were synapses onto very fine dendrites which might be filopodia from dendritic growth cones. Synaptogenesis may start with the accumulation of vesicles in dense cytoplasm near a thickened cell membrane; the postsynaptic element becomes associated with this “membrane-vesicle cluster” and matures by increasing cleft and cytoplasmic density, and by membrane thickening.
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  • 48
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    Cell & tissue research 139 (1973), S. 431-450 
    ISSN: 1432-0878
    Keywords: Cardiac muscle ; Frog ; Regeneration ; Electron microscopy ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary From the 5th day up to the end of 3rd week following local crushing of the frog ventricle myocardium, ca. 13% of myocyte nuclei, in the vicinity of the damaged zone, were labelled after a single 3H-thymidine (3HTdr) injection, and 30–50% of these were labelled after repeated 3HTdr administration. The number of myocyte mitoses was maximal (ca. 1.3%) at the beginning of the 3rd week. The reactive proliferation of myocytes was accompanied by their “partial dedifferentiation”. This involved the nuclear euchromatic rearrangement, increase in size of nuclei and nucleoli, accumulation of the sarcoplasm rich in free ribosomes and rough endoplasmic reticulum, hyperplasia of the Golgi apparatus, and the appearance of 80–100 Å in diameter cytofilaments. Electron microscope autoradiography has shown that all these changes may be more or less pronounced in myocytes incorporating 3HTdr. The myofibril ultrastructure was found to be unchanged during S phase. However, in the mitotically dividing myocytes, the majority of Z-disks were disintegrated resulting in progressive release of myofilament bundles. Both 3HTdr labelled and mitotic myocytes were anchored to the adjacent ones by desmosomes and intercalated disks. No free myoblasts were observed.
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  • 49
    ISSN: 1432-0878
    Keywords: Chloride cells ; Eel ; Gills ; Ionic transport ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé Nous avons montré par une technique autoradiographique que les ions Cl− et Na+ sont concentrés dans les cellules à chlorure de la branchie d'anguille adaptée à l'eau de mer. La signification de cette accumulation ionique plus marquée vers le pôle apical de ces cellules a été discutée par rapport à l'excrétion branchiale de ces ions en eau de mer.
    Notes: Summary With an autoradiographic technique Cl− and Na+ ions have been shown to be localized in the chloride cells of sea water eel gills. The significance of this accumulation, more marked towards the apical pole of these cells, is discussed with regard to branchial excretion of these ions in sea water.
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  • 50
    ISSN: 1432-0878
    Keywords: Hypothalamo-hypophysial system ; Development ; Monoamines ; Colour change ; Fluorescence microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In Xenopus laevis the development of hypothalamic monoaminergic cells was studied in relation to adaptation to background colour. The first melanophores appear at stage 33/34 (normal table of Nieuwkoop and Faber, 1956), gradually increasing in number. The melanine granules are dispersed throughout the cell, irrespective of the background colour. The dispersion apparently is caused by MSH released by the developing pars intermedia cells. Between stage 39 and stage 41, larvae placed on a white background changed colour from black to white due to aggregation of the melanine granules within the melanophores. With Falck's method for demonstrating monoamines, a small number of fluorescent cells was observed in the hypothalamus simultaneously with the first background-dependent colour change. These cells were arranged in a paired nucleus, bordering the third ventricle. Initially, the nucleus extends from 50 microns behind the optic chiasma to the lateral dilatations of the third ventricle; 8–10 hours later, similar cells were also found at the lateral dilatations and in the dorso-lateral part of the infundibular lobe. The cells have apical processes protruding in the ventricular lumen. Fluorescent axons, originating from the cells, were occasionally observed. Considering the above-mentioned results in combination with the electron microscopical data of Nyholm (1972), it is concluded that the MSH producing cells are under monoaminergic nervous control from the beginning of background colour adaptation.
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  • 51
    ISSN: 1432-0878
    Keywords: RNA synthesis ; Spinal ganglia cell cultures ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Dissociated cells from 9, 12 and 15 day-old chick embryo spinal ganglia were cultivated in presence of total embryo-extract, brain embryo extract, or total embryo extract supplemented with purified nerve growth factor (NGF). The cells were maintained during 4 days in Maximow assembly and during 1 month in Rose chamber. Neurons showed growth of nerve fibres. The non-neural cells evolved to spindle cells, Schwann cells, or fibroblasts. Ribonucleic acid (RNA) synthesis was followed with tritiated uridine by autoradiography. Some nerve cells showed tritiated uridine incorporation. The highest incorporations for short-term cultures were at 15 hours in presence of NGF, at 48 hours in presence of total or brain extract, and for long-term cultures at 8 days. These periods corresponded to the highest growing activity of the nerve fibres. After 4 days all the non-neural cells incorporated tritiated uridine. The tritiated uridine was first incorporated into the RNA of the nucleus and, afterwards was found also in the cytoplasm. The presence of brain extract or of NGF stimulates the incorporation of labelled uridine into RNA. No labelling was found in the nerve fibres, even after 4 hours incubation.
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  • 52
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    Cell & tissue research 150 (1974), S. 443-454 
    ISSN: 1432-0878
    Keywords: Haematopoiesis ; Lymnaea stagnalis ; Amoebocytes ; Autoradiography ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In order to investigate haematopoiesis in the freshwater pulmonate Lymnaea stagnalis, the blood cells and the connective tissue of this snail were studied by light and electron microscopy as well as by autoradiography. In the circulating blood only one type of cell, the amoebocyte, is present. Amoebocytes also occur in the connective tissue (tissue amoebocytes) as single cells, in small groups or in large accumulations. Study of the morphology and ultrastructure of blood and tissue amoebocytes shows that no differences exist between these cells, indicating that L. stagnalis does not possess a well-defined haematopoietic organ. This assumption is supported by the following observations: 1. both blood and tissue amoebocytes can act as phagocytes, 2. blood and tissue amoebocytes both have the capacity to divide (i.e. incorporate tritiated thymidine) and 3. the percentage of dividing cells in the blood and in the connective tissue is the same. These quantitative data indicate furthermore that there is no difference in the relative importance of the blood and the connective tissue in the process of haematopoiesis. Comparison of tritiated thymidine labelled cells with unlabelled amoebocytes showed that these cells do not differ with respect to their morphology and ultrastructure. Moreover, amoebocytes involved in phagocytosis and encapsulation of foreign materials or in wound healing still have the capacity to divide. The percentages of tritiated thymidine labelled amoebocytes in different snails varied considerably. It is suggested that this variation reflects differences in the physiological state of the individual snails.
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  • 53
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    Cell & tissue research 150 (1974), S. 481-492 
    ISSN: 1432-0878
    Keywords: Seminiferous tubule, ovine ; Lamina propria ; Development ; Endocrine factors ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
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    Notes: Summary The ultrastructure of the lamina propria in the ovine seminiferous tubule was studied from 54 days (postcoitum) fetuses up to sexual maturity. In young animals (aged about two months) the effect of hypophysectomy and/or hormones was also analyzed. Initially, large areas of the lamina propria already show signs of morphological differentiation. The non cellular component is a single or sometimes double lamella. Outwardly, the cellular component is represented by rounded connective tissue cells or by elongated cells, exhibiting 80 Å filaments in the cytoplasm and arranged in 3 to 4 layers. By the first week after birth, the non cellular component is formed by 8 to 10 lamellae and the cellular component shows typical contractile cells, the fibroblasts being now located only in the periphery. Basically, the same aspect is found in the adult ram, thus differing from the more extensively studied prototypes of lamina propria architecture of rodents or primates. In as much as the sheep lamina propria differentiates precociously, probably induced by fetal testicular hormones, it is relatively insensitive to hypophysectomy or hormonal substitution. Hypophysectomy and cyproterone acetate administration cause intracytoplasmic lipid deposition in the contractile cells, the other components being not changed. Some questions are raised concerning the role of this peculiar lamina propria in the function of the blood-testis barrier.
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    Cell & tissue research 151 (1974), S. 509-523 
    ISSN: 1432-0878
    Keywords: Gill ; Trout ; Secondary lamellae ; Development ; Light and electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A light and electron microscope study of secondary lamellae of trout developing at 10° C is described. Collagen is secreted by mesenchyme cells in the connective tissue of the developing gill filament. This becomes enclosed in infoldings around the peripheries of mesenchyme cells. These cells become aligned in a single plane within folds of basement membrane and epithelium. The basement membrane of opposite sides of the fold becomes connected by a thick layer of collagen. Blood spaces form around the margin of the fold, connecting afferent and efferent filament blood vessels. Endothelial granules form in cells lining the outer border of the marginal channel when blood flow begins. Rows of pillar cells separate from the proximal layer of mesenchyme cells as the secondary lamellae develops further. New secondary lamellae are added at the filament tips. At 28 days, the basement membrane consists of 2 layers, a fine fibrous layer and 5–15 orthogonally arranged layers of collagen fibres. By 31 days, the collagen is arranged at random and the layer is thinner. A clear layer is also present by 67 days. A multilayered epithelium containing mucous and chloride cells is present at 28 days. By 102 days, the secondary lamellae are covered by 2 layers of epithelial cells only. Chloride cells are present in much greater numbers in developing gills than in the adult.
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    Cell & tissue research 152 (1974), S. 13-30 
    ISSN: 1432-0878
    Keywords: Human fetal pineal gland ; Development ; Secretion ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the pineal gland of 18 human fetuses (crown-rump lengths 30–178 mm) was investigated. The pineal gland exhibits a pyramidal shape and consists of an anterior and posterior lobe. Only one parenchymal cell type, the pinealocyte, was observed. Few neuroblasts were seen between the pinealocytes and in the extended perivascular space. The pinealocytes possess all the organelles necessary for hormone synthesis. No specific secretory granule could be observed. The organ is abundantly vascularized and richly innervated. The morphology of the capillaries indicates the existence of a blood-brain barrier. The ultrastructure of the human fetal pineal gland suggests that the gland has a secretory function in early intrauterine life.
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    Cell & tissue research 154 (1974), S. 443-470 
    ISSN: 1432-0878
    Keywords: Oocytes and T-prospermatogonia ; Rat ; Quantitative analysis ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Bei der Ratte findet die sexuelle Differenzierung der Gonade zwischen dem 14. und 15. Tag post conceptionem (p.c.) statt. Während dieser Zeit teilen sich die Oogonien und deren Parallelpopulation—die M-prospermatogonien (multiplying prospermatogonia) oder I-Gonocyten—sehr häufig. Um den 17. Tag p.c. tritt die letzte Generation der Oogonien bzw. der M-prospermatogonien in die Mitose. Die Mitosen bilden häufig “synchronisierte Gruppen”. Die postmitotischen Kerne ihrer Tochterzellen—der Oocyten und der T 1 prospermatogonien (primary transitional prospermatogonia) oder II-Gonocyten—sind klein. Ihr Chromatin ist in Form gröberer Schollen der Kernmembran angelagert. Auf diese Weise kommt das typische “krustenförmige” Aussehen bzw. die Ähnlichkeit mit den Prophasen der Oogonien und M-prospermatogonien zustande. Die Oocyten durchlaufen zunächst die G1-phase (etwa 10 Std Dauer) und treten dann—am Ende des Präleptotänstadiums—in die S-phase. Dann passieren sie die verschiedenen Stadien der meiotischen Prophase und treten vom 3. Tag post partum (p.p.) ab in das Dictyotänstadium. Die T1-prospermatogonien hingegen befinden sich etwa 10 Tage lang in der G1-phase, ohne wesentliche morphologische Veränderungen aufzuweisen. Vom 4. Tag p.p. an durchlaufen sie die S-Phase. Die S-Phasen-Dauer (D-S) beider Zellarten beträgt 11.5 Std und wurde durch Doppelmarkierung mit 14C- und 3H-Thymidin bestimmt. Als am besten geeignete Termine für die Bestimmung der D-S erwiesen sich bei den Oocyten der 18. Tag p.c. und bei den T1-prospermatogonien der 5. Tag p.p. Zu diesen beiden Zeitpunkten war die Anzahl der in die S-phase ein-und austretenden Oocyten bzw. T1-prospermatogonien gleich, die Zellen in S-phase befanden sich im “steady state”. Das Kernvolumen der Oogonien und M-prospermatogonien ist etwa doppelt so groß wie das der postmitotischen Oocyten und T1-prospermatogonien. Bis zum 5. Tage p.p. nimmt das Kernvolumen der Oocyten und T1-prospermatogonien um etwa das Fünffache zu. Der Degenerationsindex der Oocyten liegt wesentlich höher als der der T1-prospermatogonien; er ist postnatal besonders hoch. Aus den T1-prospermatogonien gehen am 4. und 5. Tage p.p. durch Teilung die T 2-prospermatogonien (secondary transitional prospermatogonia) hervor. Die Kerne dieses Zelltyps sind etwas kleiner also die der T1-prospermatogonien. Die T2-prospermatogonien treten am 6. Tage p.p. in die Mitose; es entstehen die ersten A-spermatogonien.
    Notes: Summary In the rat (Wistar-WU) sexual differentiation of the gonads occurs between days 14 and 15 post conception (p.c.). At this time the oogonia and their parallel population — the M-prospermatogonia (I-gonocytes)—divide rapidly. On about day 17 p.c., the last generation of oogonia and M-prospermatogonia, frequently arranged in synchronized clusters, enters mitosis. The postmitotic nuclei of their daughter cells—oocytes and T 1-prospermatogonia (II-gonocytes)—are small; coarse flakes of chromatin are associated with the nuclear membrane causing the typical “crustlike” appearance and the similarity with the prophases of oogonia and M-prospermatogonia. After the oocytes have passed a G1-phase of approximately 10 hr, they enter the S-phase at the end of the preleptotene stage. Then they pass the different stages of the meiotic prophase until they enter the dictyate stage from 3 day post partum (p.p.) onwards. The T1-prospermatogonia, on the other hand, spend a long G1-phase of about 10 days without any conspicuous morphological change before entering the S-phase from day 4 p.p. onwards. The duration of the S-pbase (D-S) of both cell types—oocytes and T1-prospermatogonia—as determined by the double labeling method with 14C- and 3H-thymidine is found to be 11.5 hr. The most favourable time for determining the D-S was day 18 p.c. for the oocytes and day 5 p.p. for the T1-prospermatogonia. On these two days the balance was reached between the cells entering and leaving the S-phase. The nuclear volumes of the postmitotic oocytes and T1-prospermatogonia are approximately half the size of those of their precursors. Until day 5 p.p. the nuclear volumes of the oocytes and T1-prospermatogonia increase about fivefold. The degeneration index of the oocytes is considerably higher than that of the T1-prospermatogonia; postnatally it is especially high. T 2 prospermatogonia arise by mitosis of the T1-prospermatogonia on day 4 and 5 p.p. The nuclei of this cell type are smaller than those of T1-prospermatogonia. T2-prospermatogonia enter mitosis on day 6 p.p and give rise to A-spermatogonia.
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    Cell & tissue research 155 (1974), S. 135-154 
    ISSN: 1432-0878
    Keywords: Exocrine pancreas ; Frog ; Ultrastructure ; Intracellular transport ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The route by which secretory proteins are transported in the frog exocrine pancreas cell was investigated by an ultrastructural and electron microscope autoradiographic analysis of in vivo 3H-leucine labelled tissue. The ultrastructure of the cell is characteristic of serous epithelial cells and resembles that of mammalian exocrine pancreas cells very closely. Autoradiographic results revealed that the proteins, after being synthesized in the rough endoplasmic reticulum (RER), are transported through the Golgi cisternae to condensing vacuoles which subsequently change into secretory granules. The determination of the timing of this transport was complicated by a very slow turnover of leucine in the frog. Nevertheless, by a semi-quantitative approach, some time characteristics could be estimated: about 11 min after the onset of their synthesis the proteins enter the Golgi system, and about 25 min later the condensing vacuoles. Secretory granules become labelled between 60 and 120 min. These results are discussed, also in relation to the transport route and kinetics in mammalian tissue.
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    Keywords: Retinal projections ; (Tupaia glis) ; Axonal transport ; Synapse ; Autoradiography
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    Notes: Summary Retinal projections were studied in the tree shrew, Tupaia glis, by means of thaw-mount autoradiography. In this technique, unfixed and unembedded frozen sections are directly mounted on photographic emulsion coated slides. Loss of radiolabeled material through tissue processing is avoided, probably resulting in increased discriminatory sensitivity. Together with multiple injections of precursor cocktail it is possible to demonstrate at the light microscopic level (1) fibers in passage and axon terminals simultaneously, and (2) preferentially labeled axon terminals in the projection field as areas of greater grain density.
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    Cell & tissue research 109 (1970), S. 138-146 
    ISSN: 1432-0878
    Keywords: Insect muscles ; Development ; Microtubuli ; Ultrastructure
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    Description / Table of Contents: Zusammenfassung In der indirekten Flugmuskulatur von Phormia terrae-novae kann die Entwicklung der Myofibrillen deutlich in eine Anlage- und eine Wachstums-Phase unterteilt werden. Zu Beginn der Wachstumsphase wurde Puppen eine Lösung von Colchicin in die rechte Metathoraxhälfte injiziert. Als Folge dieser Behandlung lösten sich zunächst die Mikrotubuli in der Flugmuskulatur auf. In späteren Entwicklungsstadien bildeten sich atypische Verzweigungen der Myofibrillen, die zu einer partiellen Desorientierung der kontraktilen Strukturen führten. Ein Mechanismus, der solche Störungen des Orientierungmusters in der Normalentwicklung möglicherweise verhindert, wird diskutiert.
    Notes: Summary In the blowfly Phormia terrae-novae the development of myofibrils of indirect flight muscles can be divided into periods of predisposition (anlage) and of growth. At the beginning of the growth period microtubules are disrupted by injection of colchicine. This disruption is followed by the formation of atypical ramifications of myofibrils at Z-discs leading to numerous disoriented myofibrils in late developmental stages. A possible mechanism preventing these alterations during normal development is discussed.
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    Cell & tissue research 110 (1970), S. 72-84 
    ISSN: 1432-0878
    Keywords: Lung cells ; Chick embryo ; Lamellar inclusions ; Ultrastructure ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé Les pneumocytes granuleux, qui constituent l'un des principaux types cellulaires de l'épithélium pulmonaire, sont caractérisés par la présence de volumineuses inclusions osmiophiles lamellaires. Nous avons étudié l'apparition et l'origine de ces inclusions dans l'épithélium du poumon embryonnaire de Poulet, en l'examinant à différents stades du développement. Les premières inclusions lamellaires apparaissent dans le poumon de l'embryon de 16 jours. A ce stade, quelques lamelles concentriques entourent une zône centrale amorphe étendue; la périphérie des inclusions contient toujours de petites structures granulaires. Les jours suivants le nombre de cellules contenant des inclusions lamellaires augmente rapidement; en même temps, les lamelles deviennent plus nombreuses. A 19 jours, les inclusions lamellaires ont un aspect semblable à celui qu'elles ont dans les poumons d'animaux adultes. Dès l'apparition des ébauches pulmonaires, à 2 1/2 jours d'incubation, les cellules épithéliales contiennent des inclusions typiques: les inclusions granulaires. Ces organites sont caractérisés par un centre granulaire, qu'entouré un système membranaire. Ce système, simple chez le jeune embryon, évolue ensuite en se compliquant; chez l'embryon de 16 jours, il s'enroule en plusieurs couches autour de la masse centrale. Au moment où les premières inclusions lamellaires apparaissent, le nombre des inclusions granulaires augmente rapidement; on les trouve souvent étroitement associées à des vacuoles lipidiques. L'analyse des relations entre inclusions lamellaires, inclusions granulaires et vacuoles lipidiques suggère que l'inclusion lamellaire résulte de la collaboration entre une vacuole lipidique et plusieurs inclusions granulaires.
    Notes: Summary The granular pneumocytes, one of the main cellular types of the lung epithelium, are characterized by the presence of large osmiophilic lamellar inclusions. The appearance and origin of these inclusions has been studied in the epithelium of chick embryonic lung at different developmental stages. Lamellar inclusions are first seen in the lung of 16 day old embryos. At this stage, few concentric lamellae surround a large amorphous center; the periphery of the inclusions always contains small granular structures. In the following days, the number of cells containing these lamellar inclusions increases rapidly, while their lamellae progressively become more numerous. In 19 day old embryos, the lamellar inclusions are similar to those in the lungs of adult animals. From the earliest formation of the bronchial primordia, their epithelial cells contain a number of typical “granular” inclusions. These organelles are characterized by a granular center, enclosed in a membranous system. This structure becomes more complex as the embryo develops; in the 16 day old embryo, the multilayered membranous system coils around the granular center. At the time when lamellar inclusions first appear, granular inclusions increase rapidly in number and are often found in close association with lipidic vacuoles. The relationships between lamellar inclusions, granular inclusions and lipidic vacuoles are discussed. The evidence suggests that a lamellar inclusion arises from the cooperation of several granular inclusions and a lipidic vacuole.
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    Cell & tissue research 113 (1971), S. 558-563 
    ISSN: 1432-0878
    Keywords: Pterin layer ; Pigmentation ; Dermis ; Development ; Electron microscopy
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    Topics: Biology , Medicine
    Notes: Summary The fine structure of the pterin layer was investigated in both wild type Rana pipiens and Rana pipiens homozygous for the speckle mutant gene. No difference in morphology of the layer was noted between the wild type and mutant. The layer lines the outer surface of the stratum compactum of the dermis and separates this stratum from the stratum spongiosum. The pterin layer consists of extra-cellular material and contains membrane-bounded granules filled with fine spicules. Many of the spicules are somewhat similar in appearance to the initial calcification loci present in developing membrane bone. The layer first appears in the tadpole at approximately stage 14 (Taylor and Kollros, 1946); subsequent developmental stages are described.
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    Cell & tissue research 113 (1971), S. 157-173 
    ISSN: 1432-0878
    Keywords: Prostate ; Development ; Ultrastructure ; Rat
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    Notes: Summary The postnatal development of the rat prostate has been studied with the electron microscope. Major developmental changes begin during the second week after birth and involve organelles associated with the formation of secretions. The amount of granular endoplasmic reticulum and the size of the Golgi complex increase greatly. Large vacuoles that probably contain secretory material are formed, and the lumen of the prostatic acini appears to contain secreted material. Large lysosomes with polymorphic interiors are present as early as 10 days after birth, and they become numerous by the end of the third week. Differences in fine structure between the different lobes of the prostate are detectable in 10–14 day old rats. The subsequent differentiation of the granular endoplasmic reticulum into the forms characteristic of the different prostatic lobes is described. The initial changes in the prostate occur in advance of sexual maturity of the animal, and the adult appearance of the gland is attained by 4–5 weeks after birth.
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    Cell & tissue research 115 (1971), S. 442-460 
    ISSN: 1432-0878
    Keywords: Regeneration ; Young Planarians ; ARN ; Actinomycin D ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé 1. Nous avons étudié les synthèses d'ARN pendant la régénération de jeunes Planaires à l'éclosion. Elles régénèrent dans l'eau ou dans l'actinomycine D à 50 μg/ml. Les synthèses sont décelées par l'incorporation d'uridine tritiée examinée en autoradiographie histologique et ultrastructurale. Des synthèses de protéines sont évaluées par incorporation de leucine tritiée. 2. La décapitation peu après éclosion entraîne, comme pour les adultes, un accroissement de la synthèse d'ARN. Celui-ci n'apparaît pas lorsque les animaux sont traités par l'actinomycine, et cependant, les jeunes commencent à régénérer. Le retour dans l'eau permet la reprise de l'incorporation chez les jeunes Planaires. Ce pouvoir de récupération varie suivant les individus. 3. L'actinomycine D n'a pas d'effet sur l'accroissement des synthèses de protéines chez les jeunes Planaires en régénération. 4. Le microscope électronique montre que l'incorporation d'uridine est inhibée par l'actinomycine dans toutes les catégories de cellules, quel que soit le degré d'altération cellulaire. La récupération du pouvoir d'incorporation de l'uridine qui se manifeste après le retour dans l'eau des jeunes décapités dépend de l'état d'altération primitif des structures. Les cellules aux nucléoles non dissociés, c'est le cas pour la majorité des cellules morphologiquement indifférenciées, retrouvent une structure normale et incorporent à nouveau activement l'uridine tritiée. Dans les cellules aux nucléoles dissociés qui sont surtout des cellules différenciées, il n'y a pas de reprise de l'incorporation d'uridine.
    Notes: Summary 1. We have studied RNA synthesis during regeneration of young hatched Planariang, Polycelis nigra. They regenerate in tap water or in actinomycin D 50 μg/ml. RNA synthesis is tested by histologic and ultrastructural examinations of radioactivity in tissues and cells incubated in tritiated uridine. Protein syntheses are tested after incorporation of tritiated leucine. 2. If decapitated a few days after hatching, young Planarians are characterized, as adults, by an increasing synthesis of RNA. This synthesis fails to increase if animals are incubated in actinomycin during a lapse of time of 24, 48 and 96 hours after cutting. However, the ability of young animals to regenerate is not impaired. If the young animals come back into water after 48 hours of inhibition in actinomycin, incorporation of uridine can start again, with some variations according to the importance of the blastema at the end of incubation in actinomycin. 3. Actinomycin D has no effect on the increase of protein synthesis in regenerating young animals. 4. Electron microscopy shows that uridine incorporation is inhibited by actinomycin D in every cellular category at any degree of alteration. Recovery, which appears after the return of the decapitated Planarians into the water, depends on the degree of cytological alterations. The cells with non dissociated nucleoli, that is the majority of the morphologically undifferentiated cells, assume again normal structures and can incorporate actively anew tritiated uridine. Cells the nucleoli of which are dissociated, mainly differentiated cells, do not resume uridine incorporation. We suppose, in conclusion, that in young growing Planarians cells, a mechanism exists which provides information for regeneration and cellular differentiation.
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    Cell & tissue research 115 (1971), S. 593-598 
    ISSN: 1432-0878
    Keywords: Polyamines ; Uptake ; Tetrahymena ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The uptake of the diamine 3H-putrescine by Tetrahymena pyriformis GL was studied in cultures which were synchronized by heat shocks. An inverse correlation was found between the uptake of putrescine and the acid stability of DNA, but there was also a parallelism between putrescine uptake and the intracellular amount of putrescine. There was no evidence for a transformation of the labeled putrescine to other amino compounds within the cells. Electronmicroscopical autoradiography showed a structure-bound radioactivity localized to nuclear and mitochondrial structures. In the nucleus, both the chromatin and the nucleoli showed labeling.
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    Cell & tissue research 114 (1971), S. 546-556 
    ISSN: 1432-0878
    Keywords: Microvilli ; Small intestine ; Brush border ; Development ; Golgi apparatus
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    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die Frage, auf welche Weise die Enterocyten des fetalen Rattendünndarms das für die Mikrovillibildung benötigte Membranmaterial liefern, wurde elektronenmikroskopisch untersucht. Es wird angenommen, daß hufeisenförmige Strukturen, die aus mit elektronendichtem Material bedeckten Elementarmembranen bestehen und möglicherweise Längsschnitten durch kappenförmige Gebilde entsprechen, in das apicale Plasmalemm eingebaut werden und für die Bildung der Mikrovillispitzen verantwortlich sind. Diese Annahme gründet sich in erster Linie auf die Feststellung eines nahezu identischen Durchmessers von „Hufeisen“ und Mikrovilli, auf die Lokalisation der „Hufeisen“ im Terminalgespinst und ihr zahlenmäßiges Verhalten während der Mikrovillibildung. Die „Hufeisen“ entstehen im Golgi-Apparat.
    Notes: Summary The origin of membranes required for the formation of microvilli has been investigated electronmicroscopically in enterocytes of fetal rat small intestine. It is assumed that horseshoe-like structures consisting of unit membranes covered with electron-dense material, which probably represent longitudinal sections through cap-like structures, are incorporated into the apical cell membrane and give rise to the tips of microvilli. This assumption is based chiefly on the almost identical diameters of “horseshoes” and microvilli, the localization of “horseshoes” in the terminal web, and the time of appearance and disappearance of “horseshoes” with regard to development of microvilli. There are indications that the “horseshoes” originate in the Golgi apparatus.
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    Cell & tissue research 115 (1971), S. 30-45 
    ISSN: 1432-0878
    Keywords: Adrenal Cortex ; ACTH ; Autoradiography ; Stereology ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The changes occurring in rat adrenocortical cells (zona fasciculata) during an 8 day period of treatment with ACTH, were investigated by morphometric and autoradiographic methods. The most important ultrastructural change consists in a conspicuous increase in the smooth endoplasmic reticulum, that accounts for about 50% of the total increase of cellular volume. Also the mitochondrial fraction shows a significant increase, which is found to be due both to the increment in the number of mitochondria per cell and to the increase in the mean volume of organelles themselves. The quantitative autoradiographic data, indicating an increment in the incorporation of 3H-orotate and 3H-leucine into adrenocortical cells of the treated animals, allow us to conclude that the ACTH-induced ultrastructural changes are the morphological expression of a stimulation of the cellular protein synthesis. Since mitochondria are largely autonomous in the synthesis of their enzymes and structural proteins, it is possible to hypothesize that ACTH also intervenes in the regulation of the mitochondrial protein synthesis.
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    Cell & tissue research 117 (1971), S. 118-138 
    ISSN: 1432-0878
    Keywords: RNA-synthesis ; Thyroxine ; Antibiotics ; Metamorphosis ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die Frühwirkung von Thyroxin auf den RNS-Stoffwechsel in verschiedenen Geweben von Xenopus-Larven wurde autoradiographisch mit Uridin-3H untersucht. Bereits nach 4 h wird in Anwesenheit von Thyroxin (T4) eine Stimulation der nukleären RNS-Synthese festgestellt. Dabei sind das Ausmaß und der zeitliche Verlauf je nach Gewebe verschieden. Die RNS-Synthese wird nach einer T4-Vorbehandlung von 24 h am stärksten stimuliert. Während 72 h Hormon-Behandlung kann kein Transport markierter RNS vom Zellkern ins Cytoplasma festgestellt werden. Aetinomycin D hemmt die T4-induzierte RNS-Synthese bereits nach 4 h. Die stärkste Hemmung tritt nach 24stündiger Vorbehandlung auf. Puromycin hemmt die RNS-Synthese nur, wenn das Antibiotikum 24 h vor dem Hormon appliziert wird. Angesichts der starken Hemmung der RNS-Synthese durch Aetinomycin D wird angenommen, daß die T4-induzierten Veränderungen während der Metamorphose nicht nur durch Transkription spezifischer mRNS-Arten bedingt sind, sondern auch von der Bildung anderer RNS-Typen abhängen.
    Notes: Summary The early effects of thyroxine on RNA-metabolism in various tissues of Xenopus-larvae have been investigated by autoradiography using uridine-3H as precursor. In the presence of thyroxine (T4) a stimulation of nuclear RNA-synthesis is detected already 4 h after the onset of hormone administration. There are tissue-specific differences in the extent and the time course of response. T4 most effectively stimulates RNA-synthesis after 24 h of pretreatment. During 72 h of hormone treatment there is no detectable shift of labeled nuclear RNA into the cytoplasm. Actinomycin D inhibits T4-induced RNA-synthesis already after 4 h, but is most effective after 24 h of pretreatment. Puromycin inhibits RNA-synthesis to a minor extent, but only if exposure to the antibiotic precedes hormone administration. In view of the extent of inhibition of RNA-synthesis by actinomycin D, it is concluded that T4-induced metamorphic responses not only involves transcription of specific mRNA's, but must also depend upon formation of other types of RNA.
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    Cell & tissue research 115 (1971), S. 396-415 
    ISSN: 1432-0878
    Keywords: Human pineal organ ; Development ; Innervation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary This investigation is concerned with pineal organs of human embryos 60 to 150 days old. At every stage central nerve fibres enter the pineal organ by way of the habenular commissure, but are restricted to the pineal's proximal part. On about the 60th day of the development the sympathetic nervus conarii grows into the distal pole of the pineal organ from a dorso-caudal direction and plays the predominant part in the innervation of the pineal organ. After penetrating, it soon branches out and forms a network in the pineal tissue. Much later, not until the 5th embryonic month, sympathetic nerves appear accompanying the supplying vessels in the perivascular spaces. After a short time these nerves pierce the outer limiting basement membrane and penetrate the parenchyma. Towards the end of the 5th embryonic month the axons of the sympathetic nerves form varicosities containing clear and dense core vesicles. At this point large amounts of laminated granules appear primarily in cell processes, probably of pinealocytes. Isolated granules also occur in the varicosities of axons. The granules encountered here are most likely secretory granules.
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  • 69
    ISSN: 1432-0878
    Keywords: Erythropoiesis ; Nucleated Red Cells ; Cell cycle ; Autoradiography ; Cytophotometry
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    Description / Table of Contents: Zusammenfassung Um die Abhängigkeit der erythropoietischen Zellformen von ihrer Stellung im Generationszyklus (G1, S und G2) zu untersuchen, wurde das Knochenmark von vier Normalpersonen mit der Kombination von zytophotometrischer DNS-Bestimmung (Feulgen-Photometrie) und autoradiographischer Technik mit 3H-TdR (in vitro) untersucht. Die Zellen wurden vor dieser Untersuchung in den nach Pappenheim gefärbten Ausstrichen differenziert. Sowohl in der Gruppe der basophilen Erythroblasten (E1-E3) als auch bei den polychromatischen Normoblasten (E4) wurde eine postmitotische (G1) und eine prämitotische Ruhephase (G2) nachgewiesen. Beide Zellgruppen waren zu ca. 65% mit3H-TdR markiert (S). Unter den basophilen Erythroblasten war bei E1 eine G2-Phase, jedoch keine G1-Phase nachweisbar. Demgegenüber fand sich bei E3 eine ausgeprägte G1-Phase, hingegen keine G2-Phase. Bei E2 war sowohl eine G1-Phase als auch eine G2-Phase erkennbar. Nach diesen Befunden stellen die Erythroblasten E1-E3 keine Zellgruppen mit jeweils vollständigem Generationszyklus dar, sondern sind als ein Zellkompartment zu verstehen, in dem die G1-Phase vorwiegend durch die kleineren Zellen, die zytologisch die Merkmale der basophilen Normoblasten besitzen, und die G2-Phase vorwiegend durch die größeren Zellen vom Typ der Proerythroblasten und Makroblasten repräsentiert wird.
    Notes: Summary In the different types of normal human nucleated red cells the stages of the cell cycle (G1, S and G2) were investigated by combined application of the cytophotometric determination of the DNA content (Feulgen photometry) and of autoradiographic labelling using 3H-TdR in vitro. The individual cells were identified in Pappenheim stain. In the basophilic erythroblasts (E1-E3) as well as in the polychromatic erythroblasts (E4) about 62–65% of the cells were labelled (S). The unlabelled cells partly were diploid and partly were tetraploid, representing G1 and G2. The oxyphilic erythroblasts (E5) mostly were diploid and unlabelled (G1). Within the basophilic erythroblasts G1 was demonstrated mainly in E3, and G2 was demonstrated mainly in E1. In E2, G1 as well as G2 were present. The results indicate that all basophilic erythroblasts belong to one cell compartment, in which G1 is represented by the smaller cells commonly subclassified as basophilic normoblasts and G2 is represented by the large cells usually called proerythroblasts and macroblasts.
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  • 70
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    Cell & tissue research 119 (1971), S. 378-383 
    ISSN: 1432-0878
    Keywords: Seminal vesicles ; Rat ; Epithelium ; Proliferation activity ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung An 12 männlichen weißen Wistarratten unterschiedlichen Alters wurde autoradiographisch die Proliferation des Samenblasenepithels zur Zeit der Pubertät geprüft. Die Tiere waren 21, 29, 40, 50, 60 und 180 Tage alt und erhielten 1 Std vor der Tötung durch Dekapitation 2,5 μC 3H-Thymidin/g Körpergewicht i. p. appliziert. Ausgewertet wurden Autoradiogramme nach einer Expositionszeit von 18 Tagen; bestimmt wurde der Prozentsatz der markierten Zellkerne (3H-Index). Im Gegensatz zu dem bekannten exponentiellen Abfall des 3H-Indexes bei nicht-hormonabhängigen Leberepithelien jugendlicher Ratten kommt es beim Epithel der Samenblasen um den 40. Lebenstag zu einem erneuten, starken Proliferationsschub. Diese starke Wachstumszunahme ist wahrscheinlich der proliferationskinetische Ausdruck der nach Steinberger (1970) zur gleichen Zeit stattfindenden hormonellen Umschaltung in den Testes. Anschließend geht das Vermehrungswachstum des jugendlichen Tieres, durch das die Zellzahl erhöht wird, in das Erhaltungswachstum über; der 3H-Index des Samenblasenepithels erreicht den Wert des erwachsenen Tieres.
    Notes: Summary In 12 male white rats (Wistar) the proliferative activity of the epithelial cells in the seminal vesicles was studied by autoradiography. The animals were 21, 29, 40, 50, 60 and 180 days old. Each animal was given 2.5 μC/g 3H-thymidine and was killed 1 hour thereafter. We analysed the autoradiograms recording the percentage of labelled nuclei (3H-index). While the 3H-index of the non hormone-dependent epithelial cells in the liver of young rats declines continously with growing age (Stocker et al., 1964), the epithelial cells in the seminal vesicles of 40 days old rats show a remarkable rise in their proliferative activity. It is quite possible that this new peak in the proliferation is the morphological result of a preceeding switch in hormonal production of the testes as reported by Steinberger (1970). Thereafter the growth proliferation of the young rats declines into the steady state of the grown up.
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  • 71
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    Cell & tissue research 118 (1971), S. 579-592 
    ISSN: 1432-0878
    Keywords: Bye ; Innervation ; Adrenergic ; Development ; Manuals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The development of adrenergic nerves to the anterior eye segment was studied in human and guinea-pig embryos. Adrenergic terminals had already appeared in the earliest human embryos available (4–6 cm). They first appeared mainly in nerve trunks in the primitive chorioid, especially in the region of the developing ciliary body. Adrenergic nerves then grow into different structures of the eye as these develop, but typical terminals in contact with effector cells appeared late during the development, about the 25–30 cm stage. No adrenergic nerves were observed in the chamber angle. Corneal adrenergic nerves (also intraepithelial terminals) appeared much more frequently in embryos than in adults. No adrenergic neurons were observed in the retina. In the guinea-pig, the first adrenergic fibres were observed at about gestation day 35. The general principle of the development was very similar to that of the humans. At gestation day 45 to 50, the supply of adrenergic fibres was essentially that of the adult animal, except that the corneal adrenergic fibres were increasing until just before birth and that the adrenergic terminals of the chamber angle appeared shortly before term.
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  • 72
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    Cell & tissue research 119 (1971), S. 208-226 
    ISSN: 1432-0878
    Keywords: Median eminence ; Hypophysial portal vessels ; Pars distalis ; Ultrastructure ; Development
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    Notes: Summary Nerve fibres containing granular vesicles first appear in the median eminence of the rat on the 16th foetal day while secretory granules in the cells of the adenohypophysis are not present till the 17th foetal day. These observations suggest that the differentiation and early activity of pars distalis cells may depend on substances elaborated at nerve terminals in the median eminence. Although the loops of the primary plexus of portal vessels do not develop until the 4th postnatal day, substances released by nerve fibres in the neurohypophysis could reach the pars distalis through vessels already present at the 15th foetal day in the mesenchyme between the diencephalon and the adenohypophysis. This view is supported by the fact that the earliest cells to exhibit ultrastructural evidence of secretory activity are in the rostral pole of the pars distalis, the first region of the gland to become vascularized. The earliest granules to appear in the cells of the pars distalis correspond to those which are considered to contain mucoprotein hormones; somatotrophin type granules were seen only in postnatal tissues. The finding that, in the median eminence, the development of granular vesicles precedes that of agranular vesicles is discussed with reference to the times at which neurosecretory materials and monoamines become detectable in the region.
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  • 73
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    Cell & tissue research 124 (1972), S. 342-353 
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    Keywords: Hypothalamic-hypophyseal neurosecretory tracts (rat) ; Incorporation of 35S-cysteine ; Kinetics of neurosecretory material ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
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    Notes: Summary The fate of 35S-cysteine incorporated into the hypothalamic-hypophyseal neurosecretory system was followed in normal rats as a function of time from 30 min up to 30 hrs after intraperitoneal administration (11 different times, three rats each). Autoradiography and grain counting were employed to determine quantitatively the activities present in: supraoptic nucleus (SON), paraventricular nucleus (PVN), three different sites in the hypothalamic-hypophyseal tract (HHT), corresponding to its initial, middle and late portions, and neurohypophysis (NH). In SON and PVN, the kinetic behaviour of 35S-cysteine was compatible with a two-compartment model, implying decline of tracer activity in accordance with two exponential components. Of these, the slow throughput component had its closely equivalent, apparently independent, counterparts in the HHT and NH. Replicas of the rapidly abating activity peak were seen, superimposed on the slow component, in the HHT with such timing of its appearance at the various sites, as to be consistent with the concept of travel through the HHT, at substantially constant speed and without delay, of material rich in 35S-cysteine that has been primarily synthesized in the SON and PVN (with the “transport theory of neurosecretion”). This flow was calculated to have a velocity in the order of 0.6 mm per hour. The kinetic phenomena and their association with the supposed sites of synthesis, and transport, of the neurosecretory material are discussed with reference to earlier literature.
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  • 74
    ISSN: 1432-0878
    Keywords: SIF-cells ; Short adrenergic neurons ; Biogenic amines ; Osmiophilic granules ; Innervation of uterus ; Development
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    Notes: Summary A study was made of the ultrastructure of the paracervical (Frankenhäuser) ganglion of the newborn rat, using immersion fixation by glutaraldehyde (2.5%) followed by OsO4 (1%), or KMnO4 (3%) fixation. The cells containing dense—core vesicles were divided into three groups: (1) primitive sympathetic cells, (2) cells containing some dense-core vesicles 700–1100 Å in size and structurally resembling sympathetic neurons, called principal neurons, and (3) cells containing many dense-core vesicles with a larger, darker dense core, 800–2000 Å in diameter, called granule-containing cells. Using glutaraldehyde-osmium fixation, the principal neurons were further divided into dark and light cells on the basis of electron opacity of the cytoplasmic matrix. The granule-containing cells were believed to correspond to the small, intensely fluorescent cells (SIF-cells) previously described using the formaldehyde-induced fluorescence technique. On the basis of the amount of granules, the granulecontaining cells were classified as mature or maturing SIF-cells and as more primitive SIF-cells, and developing sympathicoblasts. The development of synapses in autonomic ganglia was discussed.
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  • 75
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    Cell & tissue research 126 (1972), S. 374-382 
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    Keywords: Nucleoli ; Cell cycle ; Number ; Size ; Autoradiography
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    Description / Table of Contents: Zusammenfassung Nach einer Dreifach-Markierung mit 3H- und 14C-Thymidin zur autoradiographischen Unterscheidung der Zyklusstadien wurden die Veränderungen des Nukleolus während des Zellzyklus in normalen diploiden menschlichen Fibroblastenkulturen untersucht. Es ergab sich, daß die Zellen in den ersten Stunden der Interphase die höchste durchschnittliche Nukleolenanzahl je Zellkern aufweisen (3,62 im Mittel). Im Verlauf des Zellzyklus verringert sich die Anzahl der Nukleolen je Zellkern und erreicht in der G2-Periode einen Durchschnitt von 2,51. Die durchschnittliche Fläche aller Nukleolen je Kern nimmt im Verlauf des Zellzyklus zu. Allerdings ist die Verdoppelung der DNS-Menge des Kernes im Verlauf des Zellzyklus nicht von einer Verdoppelung der Nukleolengröße begleitet. Der Quotient aus der Fläche aller Nukleolen je Kern und der Fläche des Kernes ist in den frühesten Stadien des Zellzyklus am größten und nimmt im Verlauf der Interphase leicht ab.
    Notes: Summary In diploid human fibroblast cultures the cells in different stages of the cell cycle can be distinguished by their autoradiographic patterns after labeling the cells with 3H- and 14C-thymidine. At the beginning of the interphase (up to 4 hours after the mitosis) cells show the highest mean number of nucleoli per nucleus (3.62). In the course of the cell cycle the number of nucleoli per nucleus decreases and in the G2-peroid the mean number of nucleoli per cell is 2.51. The mean total projection area of the nucleoli per cell increases in the course of the cell cycle. However, duplication of the DNA in the nuclei is not accompanied by a duplication of the nucleolar area. The proportion between nucleolar and nuclear area shows its highest value in the early interphase and decreases in the course of the cell cycle.
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  • 76
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    Cell & tissue research 126 (1972), S. 421-430 
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    Keywords: Adrenal cortex ; Rat ; Growth ; Sex-dimorphism ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Anhand des Verlaufs des 3H-Index und der Mitoserate in Anhängigkeit vom Lebensalter wurde die Proliferationsaktivität in den Zonen der Nebennierenrinde untersucht. 84 SPF-Ratten erhielten 2 μCi/g 3H-Thymidin i.p.; der Untersuchungszeitraum erstreckte sich vom 18. Trächtigkeitstag bis zur 12. Lebenswoche. Alle Zonen zeigten in der Rangfolge Glomerulosa — Fasciculata — Reticularis eine Abnahme DNS-synthetisierender Zellkerne. Geschlechtsspezifische Unterschiede im Ausmaß der Proliferationsaktivität konnten zu keiner Zeit nachgewiesen werden. Aus der Dissoziation der Kurven des 3H-Index und der Mitoserate bei vergleichbaren DNS-Syntheseraten wird auf eine Änderung der G2-Phase des Generationszyklus der NNR-Zellen in der teilexponentiellen Wachstumsphase geschlossen.
    Notes: Summary In 84 SPF-rats the poliferative activity of the adrenal cortical cells was studied from the 18th day of pregnancy up to 12 weeks post partum. Rats were given 2 μC/g tritiated thymidine and killed 1 hour thereafter. It was shown that there was no sex-related difference in the degree of proliferation that could explain the sexual dimorphism in adrenal weights. In all cortical zones a decrease in the number of labeled cells was seen during the obvservation period. The highest percentage of labeled cells was found in the glomerulosa. There exists no parallelism of the mitotic and labeling index, which gives evidence for a change in length of the G2-phase of the cell generation cycle.
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  • 77
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    Cell & tissue research 127 (1972), S. 323-346 
    ISSN: 1432-0878
    Keywords: Thymus ; Frog ; Development ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A study of the ultrastructure of the developing thymus of the leopard frog (Rana pipiens) revealed that the thymus had undergone all of the major changes which would persist through larval life and metamorphosis by the time that the animals had reached larval stage IV of Taylor and Kollros (1946). These changes included development of an outer, lymphoid cortical region and an inner, essentially nonlymphoid medulla; mitotic activity among lymphoid cell precursors and the formation of the first small lymphocytes; development of complex cysts containing PAS-positive material and the appearance of other signs of secretory activity among epithelial cells of the medulla; and differentiation of large myoid cells containing bundles of striated muscle fibrils. The changes are particularly noteworthy because they first appear during a period in which the animals are known to be developing the capacity to respond immunologically to allografts.
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  • 78
    ISSN: 1432-0878
    Keywords: Neurosecretory cells ; Pars intercerebralis ; Locust ; Autoradiography ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
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    Description / Table of Contents: Résumé Après injection de cystéine S35, les cellules A, B, C et les neurones banaux de la pars intercerebralis chez Locusta (femelles immatures et mûres) sont radioactifs. Le taux d' incorporation de la cystéine S35 dans les cellules B est identique chez toutes les femelles et il est légèrement supérieur à celui des neurones banaux. Ces résultats confirment l'inactivité sécrétoire protéique des cellules B. Les cellules C incorporent 3 à 5 fois plus de cystéine S35 que les neurones banaux. Elles synthétisent donc une ou plusieurs protéines contenant de la cystéine ce qui réaffirme leur activité neurosécrétrice chez Locusta. Les cellules A possèdent le taux d'incorporation de cystéine S35 le plus élevé: 5 à 8 fois celui des neurones banaux. Chez toutes les femelles, les cellules A synthétisent plus de neurosécrétion et en éliminent proportionellement plus que les cellules C. La neurosécrétion A est élaborée sous sa forme figurée plus rapidement (30 min) que la neurosécrétion C (60 min). Le renouvellement de la neurosécrétion A est donc quantitativement plus important et plus rapide que celui de la neurosécrétion C. Chez les femelles immatures, les cellules A et C synthétisent plus de matériel et en éliminent proportionnellement plus que chez les femelles mûres. Le temps nécessaire à l'élaboration et à la vidange des grains de neurosécrétion A est identique chez toutes les femelles. Il en est de même pour le matériel C. Le renouvellement des neurosécrétions A et C est donc plus important chez les femelles immatures que chez les femelles mûres mais il n'est pas plus rapide. L'accumulation du matériel fuchsinophile dans les cellules A et C lors de la maturation ovarienne correspond à une réduction de leur fonction neurosécrétrice: elle résulte d'une diminution de l'activité d'élimination des cellules neurosécrétrices A et C supérieure à l'affaiblissement de leur activité de synthèse.
    Notes: Summary After injection of 35S-cysteine, the A, B, C cells and the ordinary neurones of pars intercerebralis in Locusta — immature and mature females — are radioactive. The rate of incorporation of 35S-cysteine into the B cells is the same for all the females, and it is slightly higher than the rate of incorporation of 35S-cysteine into the ordinary neurones. These results demonstrate the proteinic secretory inactivity of the B cells. The C cells incorporate 3 to 5 times more 35S-cysteine than ordinary neurones. Thus, the C cells synthesize one protein or several proteins with cysteine; this observation confirms their neurosecretory activity in Locusta. The A cells have the highest rate of incorporation of 35S-cysteine: 5 to 8 times the one of ordinary neurones. In all the females, the A cells produce and release proportionally more neurosecretion than the C cells. The production of granules is faster in A cells (30 min) than in C cells (60 min). The turnover of the A neurosecretion is consequently higher and quicker than the C neurosecretion. In immature females, the A and C cells synthesize and release proportionally more material than in mature females. The time necessary for production and release of the A neurosecretion is the same for all the females. It is so for the C material. The turnover of the A and C neurosecretions is thus more important in immature females than in mature females but it is not more rapid. The accumulation of stainable neurosecretory material in A and C cells at the time of ovarian maturation is associated with a reduction of their neurosecretory activity: it is due to a decrease of the rate of release of the A and C cells being more important than their rate of production.
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    Cell & tissue research 128 (1972), S. 393-405 
    ISSN: 1432-0878
    Keywords: Peripheral nerve ; Polyamines ; Autoradiography ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
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    Description / Table of Contents: Zusammenfassung Mit Hilfe der Autoradiographie von Semi- und Ultradünnschnitten wurde die Verteilung der Radioaktivität nach Applikation von 3H-Putrescin im intakten und im degenerierenden N. ischiadicus der Ratte sowie in Spinalganglien untersucht. Im intakten und im geschädigten Nerven war die Radioaktivität, die zum weit überwiegenden Anteil als Spermidin und Putrescin vorkam, in allen zellulären Bestandteilen des Nerven, im Cytoplasma, in den Kernen und sehr deutlich auch in den Markscheiden, lokalisiert. Im extrazellulären Raum und über den Kollagenfibrillen war demgegenüber nur eine sehr geringe Radioaktivität festzustellen. Die physiologische Funktion von Spermidin und Putrescin im Myelin und den anderen Zellbestandteilen wird in erster Linie im Zusammenhang mit der in diesen Strukturen ebenfalls lokalisierten RNA diskutiert, da zahlreiche Hinweise für eine Rolle der Polyamine in der RNA- und Proteinsynthese vorliegen.
    Notes: Summary The distribution of radioactivity from 3H-putrescine was studied in intact and degenerated sciatic nerves, and spinal ganglia of rats by means of high resolution autoradiography. During the first three days after the administration of the labeled putrescine, the main proportion of radioactive material in the nerves was represented by spermidine and putrescine. Both, in intact and degenerating nerves, developed silver grains were deposited in all cellular components of the nervous tissue, the myelin sheath being markedly tagged. Perineural tissue was also labeled considerably, however, there was no significant amount of label in the extracellular space and in the collagen fibrils. The possible physiological significance of putrescine and spermidine in myelin and in other cellular components of nerves is discussed.
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    Cell & tissue research 128 (1972), S. 555-563 
    ISSN: 1432-0878
    Keywords: Astrocytes ; Capillaries ; Spinal cord ; Blood brain barrrier ; Development
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    Notes: Summary Glio-vascular relationships were studied in the developing rat cervical spinal cord with electron microscopy. Capillaries were first evident on the eleventh prenatal day and were surrounded by undifferentiated cells and neuroblasts separated from the capillary wall by a perivascular space. This space persisted until day thirteen, when basement membranes began to appear. Small cellular processes containing glycogen were visible adjacent to the capillary basement membrane beginning at day fifteen and became more prominent as development proceeded. The origin of these cellular processes was not apparent, but they were most likely collaterals of epithelial elements. In prenatal animals neuroblasts or neurons were in direct contact with the capillary basement membrane. Cells resembling adult astrocytes were first observed during the nineteenth day. Astrocytic processes completely invested the capillaries, separating them from neurons in the spinal cord of all postnatal animals.
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    Cell & tissue research 129 (1972), S. 237-255 
    ISSN: 1432-0878
    Keywords: Subcommissural organ ; Rana temporaria ; Light/Darkness ; Autoradiography
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    Topics: Biology , Medicine
    Notes: Summary The influence of long daily photoperiods and of continuous darkness on the subcommissural organ (SCO) of Rana temporaria was studied. The amount of aldehyde-fuchsin (AF) positive material in the apical cell parts of the SCO proves to be less in light-adapted than in darkness-adapted animals in winter. The nuclear volume in the SCO of light- and of darkness-adapted animals, however, does not show any clear differences. Distinct differences in incorporation rate of 35S-cysteïne between the SCO of light- and of darkness-adapted animals cannot be observed either in winter or in summer. The conclusion must be that light/darkness conditions hardly influence the secretory activity of the SCO cells of Rana temporaria. The results mentioned above were compared with those of experiments on pineal gland and preoptic nucleus. Incorporation of 35S-cysteïne, which proceeds rather slowly, firstly takes place in the apical, i.e. supranuclear and perinuclear cell parts. Then the AF positive material located subnuclearly becomes gradually labelled. This is in support of the assumption that the apical cell parts are primarily concerned with synthesis and the basal cell parts with storage of secretory material. A marked influence of temperature on localization, appearance and amount of AF positive material in SCO cells has been observed.
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    Cell & tissue research 129 (1972), S. 278-289 
    ISSN: 1432-0878
    Keywords: Midgut epithelium ; Insects ; Development ; Metamorphosis ; Electron microscopy
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    Topics: Biology , Medicine
    Notes: Summary The ultrastructural alterations in the anterior midgut epithelium of the fly Calliphora were investigated by electron microscopy. Nine developmental stages, from late larval to late adult, were studied. During metamorphosis, a tube is formed by proliferation of undifferentiated cells residing in cell nests in the basal part of the larval epithelium. The process of microvillus formation is described and compared with that in the embryonic stage. Differences between larval and imaginal cells were found in the rate of microvillus formation and in the occurrence of dense vesicles. The formation of a basal labyrinth coincides roughly with microvillus formation. Glycogen deposits occur mainly in the pupal stage and are almost always absent after emergence. Epithelial crypts are formed in late pupae by modification of the existing layer of cells together with a localized development of muscle fibres. In the adult stage changes may take place in the form of the cell apex, which generally assumes a more pointed shape, and in the amount of osmiophilic material, aggregating almost exclusively in the supranuclear part of the cell.
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    Cell & tissue research 134 (1972), S. 505-518 
    ISSN: 1432-0878
    Keywords: Gastric mucosa ; Parietal cells ; Zymogen cells ; Cell division, DNA synthesis ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
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    Notes: Summary With autoradiography after labelling with tritiated thymidine, the kinetics of zymogen and parietal cells were studied in the gastric mucosa of mice. After one intraperitoneal injection of the DNA precursor, zymogen cells in the DNA synthesis phase were clearly identified on autoradiograms, whereas no parietal cells were seen to synthesize DNA. In another group of mice, multiple injections were used in order to obtain a greater number of labelled cells. Following the latter procedure, analysis of grain count distributions over labelled zymogen cells and of labelling indices allowed detection of two subsequent zymogen cell divisions within an interval of approximately two months. This indicates that the cell turnover of zymogen cells is at least partly assured by their own mitotic activity. By contrast, parietal cells showed no evidence of cell division, but appeared to be derived through differentiation from other cells in the neck area of the gland. Analysis of spatial distribution of the labelled parietal cells in the glandular tube indicated that, in time, most newly formed parietal cells undergo a slow migration directed downwards to the bottom of the fundic glands. These results clearly show that the zymogen and the parietal cell population of the fundic glands have a different kinetic behaviour.
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  • 84
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    Cell & tissue research 135 (1972), S. 245-273 
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    Keywords: Adrenal cortex ; Primary cultures ; ACTH ; Stereology ; Autoradiography ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A method of cultivation involving both repeated trypsinisations (at room temperature) and explantation of the tissue fragments on polythene discs has been shown to be apt to the growth in vitro of rat adult decapsulated adreno-cortical tissue. This is the first time that the successful cultivation of such a tissue is reported. The technique and its applications are discussed. The effects of β1–24 corticotrophin (ACTH1–24) on the rat adult adrenal cultures have been examined by both electron microscopy and autoradiography. Zona fasciculata and reticularis cells grown in the absence of ACTH for long terms (15–16 days) survive and proliferate as dedifferentiated elements. If ACTH1–24 is added to the cultures, adrenocortical cells will, within 2 days, simultaneously increase their proliferation rate and differentiate. After 7 days of treatment, cortical cells exhibit not only fully differentiated but even hypertrophic morphologic features. Significant stimulations of adrenal DNA, RNA and gross protein synthesis have been found to take place at different times after the starting of the ACTH1–24 treatment. These data are discussed in relation to the findings previously reported in literature. Rat adult adrenal gland tissue cultures are proposed as a non-previously available tool for investigations into the physiopathology of the adrenal cells to be carried out in a carefully controlled environment.
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  • 85
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    Cell & tissue research 142 (1973), S. 409-430 
    ISSN: 1432-0878
    Keywords: Oocyte ; Honeybee ; Vitellogenesis ; Yolk pattern ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die Oogenese der Bienenkönigin (Apis mellifica) kann in 6 Stadien eingeteilt werden. Proteinsynthese und Dottereinlagerung in der Oocyte werden autoradiographisch und mittels Trypanblau-Vitalfärbung untersucht. Euplasmatische Proteinsynthesen finden in allen Eifollikeln bis zum frühen Stadium 5 statt. Vitellogenese-aktiv sind nur die Oogenese-Stadien 3 und 4. Die pinocytäre Einschleusung dotterpflichtiger Haemolymphproteine ins Ooplasma nimmt etwa 20 min in Anspruch. 10 min später sind kleinste neugebildete Dotterkugeln in der äußersten Oocytenperipherie zu erkennen. Aus ihnen werden binnen 1 $${\raise0.5ex\hbox{$\scriptstyle 1$}\kern-0.1em/\kern-0.15em\lower0.25ex\hbox{$\scriptstyle 2$}}$$ —2 h große Dotterschollen von ca. 20 μm φ. Die Vitellogenese-Phase eines einzelnen Follikels dauert insgesamt 3 Tage. Dotterschollen werden nur im Bereich des freien Follikelepithels gebildet. Sie wandern einzeln ins zentrale Ooplasma ein, wo unterschiedlich alte Schollen durchmischt abgelagert werden. Dotterfrei bleibt ein Euplasmahof, der den Vorderpol des Eies markiert. Im Ooplasma und in den Nährzellen erfolgt sicher keine Synthese von Dottermaterial. Ein Beitrag der Follikelepithelzellen zur Dotterbildung kann nicht vollständig ausgeschlossen werden. Das zeitliche und räumliche Muster der Dottereinlagerung wird diskutiert unter Berücksichtigung der Determination der Oocyten-Achsen und der Präformation von ooplasmatischen Kontrollzentren für die frühe Embryogenese.
    Notes: Summary Oogenesis in the honeybee queen (Apis mellifica) can be divided into 6 developmental stages. By autoradiography and vital staining with trypan blue protein synthesis and yolk incorporation into the oocyte were studied. Euplasmic protein synthesis occurs in all egg follicles up to the early stage 5. Only the stages 3 and 4 are active in vitellogenesis. The resorption of vitellogenic haemolymph proteins by pinocytosis needs about 20 min. 10 min later very small newly formed yolk globules can be recognized in the outermost periphery of the oocyte. After 1 $${\raise0.5ex\hbox{$\scriptstyle 1$}\kern-0.1em/\kern-0.15em\lower0.25ex\hbox{$\scriptstyle 2$}}$$ —2 hrs large yolk platelets of ca. 20 μm in diameter arise from them. The whole vitellogenesis of a single follicle lasts 3 days. Yolk globules are formed only in the area of the free follicle epithelium. They migrate separately into the central ooplasm where yolk platelets of different age are deposited in a mixed pattern. An euplasmic halo remains free of yolk thus marking the anterior pole of the egg. It is shown that no yolk material is synthesized in the ooplasm and in the trophocytes. A contribution of the follicle epithelium to yolk formation can not totally be excluded. The temporal and spatial pattern of yolk deposition is discussed. The determination of the oocyte axis and the preformed ooplasmic reaction centers for early embryogenesis are considered.
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  • 86
    ISSN: 1432-0878
    Keywords: Hypophysis ; Rana temporaria ; Development ; Corticotropin cells, melanotropin cells ; Immunofluorescence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary During the embryonic and larval developmental stages of the frog, Rana temporaria L, anti-β 1–24, α 17–39 corticotropine, α and β MSH antibodies were used to define, with immunofluorescence technique, the appearence of corticotropic and melanotropic cells. A very small number of fluorescent corticotropic cells appears for the first time during the embryonic stage (10 mm), just before the differentiation of the pars intermedia. The cells are small, their large nucleus is surrounded by a fine rim of fluorescent cytoplasm. During premetamorphic stage, the anti-ACTH antibodies (anti-β 1–24 and anti-α 17–39 corticotropine) reveal more fluorescent cells in the whole pars distalis. The pars intermedia cells can also be visualized by both antisera. At the end of prometamorphosis and during climax the corticotropic cells show a more precise localization. As in adult frog pars distalis, they are concentrated in the rostral half of the lobe. With the same technique anti-α and β MSH antibodies reveal only the cells of the pars intermedia. No other cell type of the pars distalis reacts with these antibodies. This technique has the advantage to show that the ACTH and the MSH cells appear very early during the embryonic life.
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  • 87
    ISSN: 1432-0878
    Keywords: Basement membrane ; Glucose-H3 ; Teleost ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Autoradiography has been employed to investigate the site of origin of the adepithelial basement membrane, or basal lamina, of the skin of Fundulus heteroclitus. Both tritiated glucose and proline were used as radioactive precursors in organ culture. Glucose was progressively segregated and concentrated in two areas of the epithelium: (1) in the superficial layer of cells near the external surface, and (2) in the cortex of the basal layer near the basement membrane. After 12 hours the basement membrane was also labeled, and after 24 hours the epithelium, basement membrane (basal lamina), and basement lamella were all labeled. We have concluded that the label over the superficial layer of epithelium near the external surface of the fish represents glucose incorporation into mucous secretion products; and that label over the basal cell layer, basement membrane, and basement lamella represents synthesis by the epithelium of glucose-rich components, perhaps mucoproteins, of the basement membrane and of the ground substance of the basement lamella. Not all areas of the epithelium and underlying connective tissue incorporated glucose at the same time, and only after 24 hours were unlabeled areas of the skin eliminated. Proline incorporation was much less specific than that of glucose. Although the epidermis and dermis were heavily labeled, proline was incorporated in almost every tissue of the fish. The value of proline as a specific label for collagen is questioned.
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  • 88
    ISSN: 1432-0878
    Keywords: Sympathetic neurons ; Chromaffin cells ; SIP cells (Newborn rat) ; Development ; Administration of hydrocortisone ; Stretch preparations ; Fluorescence microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Air-dried stretch preparations were used to study adrenergic nerve fibres and catecholamine-containing cells with the formaldehyde-induced fluorescence method in the abdominal tissue block containing the para-aortic paraganglia, in the neurovascular structures of the cervical region including the carotid body, in the bladder, in the ileum, in the mesentery, in the vagus nerve and in the sympathetic ganglia of 5- or 15-day-old rats. The adrenergic nerves and the catecholamine-containing cells were well preserved and showed little or no diffusion of amines. While most intensely fluorescent cells of the main para-aortic body disappeared during the first two postnatal weeks, some such cells survived and they showed long, slender fluorescent processes. Administration of 20 mg/kg of hydrocortisone acetate daily for 5 days after birth caused a striking increase in the number and size of the clusters of the intensely fluorescent cells in the organ of Zuckerkandl, in the sympathetic ganglia and in the bladder, as well as an increase in the fluorescence intensity of the carotid body. In rats treated with hydrocortisone for 5 days and left to recover for 10 days an increased fluorescence was still observed. However, in the organ of Zuckerkandl the intensely fluorescent cells of hydrocortisone-treated 15-day-old rats showed less processes than those of the control rats of the same age.
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  • 89
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    Cell & tissue research 110 (1970), S. 173-184 
    ISSN: 1432-0878
    Keywords: Submandibular gland ; Secretory units ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of the secretory units of the mouse submandibular gland was studied according to the developmental sequence. The embryonic submandibular gland consists of terminal tubules and ducts. Myoepithelium is associated only with the terminal tubules, and the cells of the primary intercalated ducts show characteristics of the young striated duct cells. The major changes shortly after birth consist of: 1) opening of the secretory lumina, 2) increasing rough ER and its altered configuration, 3) dilatation of Golgi cisternae and 4) changes in the granular structure. These findings suggest that the salivary secretion first occurs after birth, and acinar differentiation or transformation of the secretory cells of the terminal tubules is induced and profoundly affected by the commencement of the secretory activity. In the intercalated ducts this process is somehow inhibited, and the granular cells found in the adult can be considered as the remnants of the secretory cells of the terminal tubules.
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  • 90
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    Cell & tissue research 110 (1970), S. 401-443 
    ISSN: 1432-0878
    Keywords: Integument ; Oenocytes ; Structure ; Development ; Culex pipiens
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung 1. Struktur und Entwicklung des Integuments und der larvalen Oenocyten während des Puppen- und pharaten Imaginalstadiums von Culex pipiens L. (Dipt.) werden beschrieben. 2. Auf- und Abbau der pupalen und die Anlage der imaginalen Cuticula verlaufen innerhalb enger zeitlicher Grenzen. 3. Beim Abbau der pupalen Endocuticula erscheint immer die Lamina der jeweils innersten Lamelle als „Häutungsmembran“. 4. Die Oenocyten sind durch ihr agranuläres, tubuläres endoplasmatisches Retikulum (ATER) und dessen Veränderungen charakterisiert. Die Struktur der Oenocyten gleicht der steroidproduzierender Wirbeltierzellen. 5. Das Aussehen der Oenocyten ändert sich kurz nach der Puppenhäutung hauptsächlich durch die kontinuierliche Zunahme von sog. Lipidvesikeln. Diese Vesikel entstehen durch Erweiterungen tubulärer Elemente des agranulären endoplasmatischen Retikulums. 6. Im Lichtmikroskop erscheinen diese Veränderungen als Kanalstrukturen („Sekretionsphase“) kurz nach der Puppenhäutung; später nimmt das Cytoplasma eine mehr vakuoläre Struktur an („Degenerationsphase“). 7. Mit Sudanschwarz B und Sudan III/IV lassen sich Lipide in den Erweiterungen der Tubuli des agranulären endoplasmatischen Retikulums (= Lipidvesikel) nachweisen. Nach Osmiumsäure-Fixierung sind sie nicht darstellbar. 8. Kurz vor der Imaginalhäutung kommt es in den Oenocyten zu massiver Autophagie. Dieser folgt ein Abbau des ATER und anderer Teile des Cytoplasmas. 9. Es gibt keinen Hinweis, daß die Oenocyten direkt für die Bildung der epicuticularen Lipide verantwortlich sind.
    Notes: Summary 1. Structure and development of the integument and the larval oenocytes during the pupal and pharate imaginai stage of Culex pipiens L. (Dipt.) are described. 2. Formation and digestion of the pupal cuticle and the formation of the imaginai cuticle take place within temporarily fixed limits. 3. While the pupal endocuticle is digested the lamina of the at times innermost lamella appears as a “ecdysial membrane”. 4. The oenocytes are characterized by their agranular, tubular endoplasmic reticulum (ATER) and its changes. The structure of the oenocytes is comparable to that of vertebrate cells engaged in steroid hormone synthesis. 5. The morphology of the oenocytes shortly after pupal ecdysis changes mainly by the continual raising of so called lipid vesicles. These vesicles arise from dilatations of tubular elements of the agranular endoplasmic reticulum. 6. Studied under the light microscope these changes appear as channel structures (“secretory phase”) shortly after pupal ecdysis; later on the cytoplasma becomes vacuolar in structure (“degeneration phase”). 7. By staining with Sudan black B and Sudan III/IV lipids can be demonstrated in dilatations of the tubules of the agranular endoplasmic reticulum. However they do not stain after fixation with osmium tetroxide. 8. In the oenocytes massive autophagy takes place just before imaginai ecdysis. It is followed by breakdown of the ATER and other parts of the cytoplasma. 9. There is no evidence that the oenocytes are directly responsible for the formation of epicuticular lipids.
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  • 91
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Corticosterone ; Autoradiography ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects of corticosterone on adrenocortical cells of intact and hypophysectomized ACTH-treated rats were investigated by morphometric and autoradiographic methods. The data obtained in these experiments allow us to make the following conclusions: 1 The most important morphological parameter for assessing the activity of a steroid-secreting cell is the quantity of smooth endoplasmic reticulum. 2 The decrement in the smooth reticulum in adrenocortical cells of rats treated with corticosterone is due to an inhibition of the protein synthesis by the hormones themselves. 3 There is in vivo a direct negative feed-back control mechanism at the adrenal level, mediated by an inhibition of the RNA synthesis by the corticosteroid-hormones. 4 The trophism of the mitochondrial fraction of adrenocortical cells is controlled by ACTH. It is possible to hypothesize that ACTH intervenes in the regulation of the mitochondrial RNA and DNA synthesis.
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  • 92
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    Cell & tissue research 113 (1971), S. 174-187 
    ISSN: 1432-0878
    Keywords: Hypothalamo-hypophysial system ; Rana temporaria ; Illumination ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The influence of a long daily photoperiod and continuous darkness was studied on the hypothalamo-hypophysial system of Rana temporaria. After six weeks of treatment (December-January 1968/1969) the secretory activity of the hypothalamo-hypophysial system of the light-treated animals was enhanced. The amount of aldehyde-fuchsin positive material in the preoptic nucleus increased as a result of the light treatment, and decreased in the median eminence, whereas in the posterior lobe no difference could be observed between the light- and dark-treated animals. The karyometric results showed an increase of the nuclear volume of the cells of the preoptic nucleus after light treatment; small differences were noticed between distinct areas of the preoptic nucleus. Autoradiographic data especially showed that light influenced the hypothalamo-hypophysial system to a high degree. Half an hour after the injection of 35S-cysteine, the incorporation of the isotope in the preoptic nucleus of the light-treated animals was five times as much as in the dark-treated animals. In the median eminence and in the posterior lobe, the autoradiographic results confirmed the results found with regard to the amount of aldehyde-fuchsin positive material. Labelled material is released only from the median eminence and not from the posterior lobe.
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  • 93
    ISSN: 1432-0878
    Keywords: Substantia nigra ; Rat ; Incorparation of 3H-Dopamine, 3H-Serotonin and 3H-Norepinephrine ; Axo-dendritic Synapses ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In autoradiographies of substantia nigra in rat, it has been observed that after intraventricular injections of 3H-dopamine and 3H-norepinephrine respectively the silvergrains are accumulated in nigra neurons and their dendritic branches. The incorporation was more pronounced in the case of 3H-norepinephrine than 3H-dopamine. This seems to indicate that exogenous norepinephrine may have stronger affinity to nigra neurons and their dendrites than exogenous dopamine. In addition, some 3H-dopamine and 3H-norepinephrine labelled nerve terminals were observed in axo-dendritic synapses. In contrast to these data, 3H-5HTP and 3H-5HT administration showed almost all silver grains accumulated in the neuropil when observed in light microscopic autoradiography. Electron micrographs further reveal that the incorporation of 3H-5HTP and 3H-5HT was mostly within axo-dendritic boutons with more frequent dense core vesicles. These data again strongly suggest that substantia nigra receives a large number of serotoninergic fibres forming axo-dendritic synapses which may play an important role in modulation of substantia nigra function.
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  • 94
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    Cell & tissue research 118 (1971), S. 35-48 
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; ACTH ; Mitochondria ; RNA synthesis ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The incorporation of 3H-thymidine and 3H-uridine into adrenocortical cells of intact and ACTH-treated rats was investigated by high-resolution autoradiography. The quantitative analysis of autoradiographs shows no effect of ACTH on the incorporation of 3H-thymidine, at least in our experimental conditions. On the contrary, ACTH was found to enhance the incorporation of 3H-uridine into both adrenocortical nuclei and mitochondria. These findings are discussed in relation to numerous biochemical and morphological data, indicating that ACTH stimulates the synthesis of enzymes and structural proteins of adrenocortical cells. It is suggested that the mechanism of action of ACTH on adrenal cortex, consists in an integrated stimulation of both nuclear and mitochondrial DNA-dependent RNA synthesis.
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  • 95
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    Cell & tissue research 120 (1971), S. 309-320 
    ISSN: 1432-0878
    Keywords: Oocytes ; Ribonucleic acid synthesis ; Insects ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A large DNA containing body is found in oocytes of the house cricket, Acheta domesticus. Little or no RNA synthesis is associated with the DNA body during the leptotene, zygotene, and pachytene stages of meiotic prophase I. During the early diplotene stage of development, large masses of nucleolar material begin to accumulate at the periphery of the DNA body. The onset of RNA synthesis correlates with a change in the histochemically detectable histone proteins associated with the DNA body. In ovaries of animals injected with uridine-H3, most of the label accumulates in ribosomal RNA. Autoradiographic studies show that the cytoplasm of late diplotene stage cells accumulates uridine label to a greater extent than does the cytoplasm of early diplotene stage cells. Increased transport of nucleolar material through the nuclear envelope of late diplotene stage cells accounts for the increased cytoplasmic labeling.
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  • 96
    ISSN: 1432-0878
    Keywords: Synaptic vesicles ; Development ; Golgi apparatus ; Smooth endoplasmic reticulum ; Zinc iodide-osmium technique
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Routine electron microscopy and a zinc iodide-osmium tetroxide technique (ZIO), recently found to be specific for synaptic vesicles, were used to study the origin of synaptic vesicles during postnatal development in the lumbosacral enlargement of the albino rat. In immature nervous tissue, a large number of vesicles, indistinguishable from synaptic vesicles (S vesicles), were found in the Golgi apparatus and in different portions of the axon where they were often intermingled with elements of the smooth endoplasmic reticulum (SER). Ten to twenty percent of these S vesicles within the Golgi apparatus as well as the majority of these vesicles in all parts of the axon were positive to ZIO. Much of the SER in axons was also positive. The number of vesicles and elements of the SER showed some decrease in the non-terminal portion of axons on day 21 and even more of a decrease in adult neurons. These data suggest that synaptic vesicles are produced in the Golgi apparatus and SER in immature neurons. The decrease in S vesicles and SER in adult neurons suggests a drop in synaptic vesicle production after synaptogenesis has ended. In addition, the material that has been studied shows that ZIO staining is not limited to synaptic vesicles during development since oligodendroglia and endothelial cells are also stained during this period.
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  • 97
    ISSN: 1432-0878
    Keywords: Regeneration ; Young Planarians ; Actinomycin D penetration ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé Nous avons montré, à l'aide d'actinomycine tritiée, que cet inhibiteur pénètre en quantité égale dans les cellules de planaires adultes qui ne régéénèrent pas en présence de fortes concentrations (50 μg/cm3) et dans celles de jeunes planaires qui peuvent former un blastème en présence d'actinomycine D, malgré l'inhibition de nouvelles synthèses d'ARN qui en résulte. Chez les jeunes, le taux de pénétration de l'antibiotique est comparable dans les noyaux des cellules indifférenciées qui participent à la formation du blastème et dans les noyaux des cellules différenciées. Les noyaux à nucléoles dissociés ne sont pas plus radioactifs que les noyaux où le nucléole est seulement appauvri en granulations. La radioactivité diminue uniformément dans toutes les cellules si les animaux sont remis en élevage dans l'eau. La radioactivité cytoplasmique observée est probablement due à la nature des fixateurs qui favorisent la rétention de molécules non liées. Nous pouvons conclure que les noyaux de toutes les catégories cellulaires présentent la même perméabilité à l'actinomycine. Celle-ci est présente dans les cellules de régénération des jeunes qui édifient cependant un blastème où le taux de synthèse des protéines est au même niveau que dans une régénération normale.
    Notes: Summary 3H actinomycin inhibitor of RNA synthesis enters equally cells of adult planarians which never regenerate when applying the drug at high concentration (50 μg/cm3), and young planarians which can form a blastem in the same solution; regeneration occurs despite of the inhibition of new RNA synthesis which ensues. Ultrastructural histoautoradiographs of newly hatched Planarian tissues show that this drug enters equally nuclei of undifferentiated cells which make up the blastem of regeneration and whose nucleoli are not dissociated, and nuclei of differentiated cells whose nucleoli are very often dissociated. The radioactivity is very often located upon heterochromatin. After return of the animals into water, radioactivity becomes reduced evenly in all cells. The cytoplasmic radioactivity that we have observed probably depends on the nature of fixatives which favour the retention of non linked molecules. We can conclude that the nuclei of all cells have the same permeability to actinomycin D, whatever the state of morphological differentiation. The inhibitor is present within the regeneration cells of young Planarians which build a blastem wherein the rate of protein synthesis is at the same level as in normal regenerating tissues.
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  • 98
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    Cell & tissue research 120 (1971), S. 321-331 
    ISSN: 1432-0878
    Keywords: Liver Cells Polyamines ; Xenopus laevis ; Autoradiography ; RNA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distributions of 3H-putrescine and 3H-uridine were studied autoradiographically in cultured Xenopus laevis liver cells. Biochemical assay showed that at 4 h 10%, and at 24 h 30 % of the putrescine label was recovered as spermidine. Grain counts per unit surface area in light microscopic autoradiographs indicate that the 3H-polyamines show a similar intranuclear accumulation as 3H-uridine with a definite association with the nucleolus. The time course is different, however since 3H-polyamines continue to accumulate in the nucleus, while 3H-uridine reaches a peak nuclear concentration within 30 min and drops to one-half after 24 h. No instance of grains overlying mitotic figures was observed. These findings indicate an association of 3H-polyamines with nuclear and nucleolar RNA.
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  • 99
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    Cell & tissue research 124 (1972), S. 433-444 
    ISSN: 1432-0878
    Keywords: Insect ; Fat body ; Development ; Protein body ; Electron microscopy ; Histochemistry ; Lipoprotein ; Cytology ; Lipid globule ; Silkworm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A developmental study at the electron microscopic level was conducted of the fat body cells of Hyalophora cecropia (L.). During the last larval instar the fat body increases in volume and the cells exhibit a well developed rough endoplasmic reticulum and protein bodies of diverse sizes. In the pupal fat body, the protein bodies appear to be enclosed by a double membrane and contain glycogen granules, ribosomes and mitochondrion-like structures. In addition, there are large lipid globules, cytolysomes and rough endoplasmic reticulum. The ultrastructure of the protein bodies suggests the development of large bodies by fusion of smaller protein bodies. Changes in fat body cell ultrastructure were followed during adult development and cytological evidence was obtained for the depletion of protein, glycogen and lipid in the female during this period. The female adult fat body cell contains free ribosomes, protein bodies, many mitochondria, a few lipid globules and glycogen granules. The male moth fat body cells have many mitochondria, a few glycogen granules, essentially no protein bodies, but an abundance of large lipid globules. Studies on the influence of egg maturation on the morphology of the fat body of Hyalophora gloveri (L.) revealed that ovariectomy of pupae yielded adults having more fat body than normal females, and that the fat body cells of the ovariectomized animals contained more glycogen, lipid and protein. Male pupae receiving ovarian implants developed into adults containing eggs and possessed more fat body than normal females but less than normal males. Very few glycogen granules were found in the fat body cells of normal males or males with implanted ovaries.
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  • 100
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    Cell & tissue research 126 (1972), S. 182-192 
    ISSN: 1432-0878
    Keywords: Thyroid ; Parafollicular cells ; Adrenergic nerves ; 3H-L-DOPA uptake ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The cellular and subcellular distribution of radioactivity in the mouse thyroid gland different times (20 min — 8 hours) after intravenous administration of 3H-L-DOPA was studied by means of quantitative electron microscopic autoradiography. High concentrations of autoradiographic silver grains occur over parafollicular cells and adrenergic nerves while the labelling of follicular cells and lumina is low or absent and similar to the labelling of connective tissue cells at all observation times. Over the parafollicular cells high levels of radioactivity can be recorded already 20 min after administration of the labelled amino acid. The grain counts are highest at 1 hour and decrease then at 2.5 and 8 hours. The intracellular distribution of label is similar at all observation times; thus, the concentration of silver grains over the typical cytoplasmic granules of the parafollicular cells is 4–5 times higher compared to the concentration over the remainder of the cytoplasm and the nucleus. Treatment with a decarboxylase inhibitor prior to the injection of 3H-L-DOPA results in a low and uniform labelling of all thyroid cells. This finding, taken together with the observation that also pretreatment with reserpine abolishes the autoradiographic reaction over the cytoplasmic granules, gives strong support to the idea that the great majority of silver grains observed over parafollicular cells represents dopamine formed by decarboxylation of the labelled precursor.
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