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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 14 (1974), S. 309-315 
    ISSN: 1432-0827
    Keywords: Osteoblast ; Matrix ; Bone ; Scanning electron microscope
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Les territoires sécrétoires des ostéoblastes d'os pariétal de rats sont déterminées en utilisant la microscopie électronique à balayage. Le territoire moyen de 4.620 cellules, dans 19 territoires, est de 154 μm2 par ostéoblaste. Les valeurs extrêmes par champ varient de 136 à 177 μm2 par ostéoblaste. Quatre cent cellules sont mesurées individuellement; la valeur moyenne par ostéoblaste est de 143 μm3 avec une déviation standard de 33. Le taux d'apposition journalier, mesuré par la tétracycline pendant 8 jours, est de 3.12 μm (déviation standard 0.22). Ce qui correspond à une production matricielle journalière d'environ 470 μm3 par ostéoblaste.
    Abstract: Zusammenfassung Die Ausscheidungsbereiche von Ratten-Osteoblasten des Scheitelbeines wurden mit dem Raster-Elektronenmikroskop direkt gemessen. Der durchschnittliche Bereich von 4620 Zellen in 19 Gesichtsfeldern war 154 μm2 per osteoblast. Der Streubereich lag in den verschiedenen Gesichtsfeldern zwischen 136 und 177 μm2 per Osteoblast. 400 Zellen wurden einzeln gemessen. Bei diesen war der Durchschnittswert per Osteoblast 143 μm2, mit einer Standard-Abweichung von 33. Die tägliche Anlagerungsrate während einer Periode von 8 Tagen war 3,12 μm (Standard-Abweichung 0,22); sie wurde mittels Tetracyclinmarkierung der Mineralisierungsfront gemessen. Dies ergab eine tägliche Produktionsrate der Matrix von etwa 470 μm3 per Osteoblast.
    Notes: Abstract The secretory territories of rat osteoblasts on the parietal bone were measured directly using scanning electron microscopy. The mean territory of 4620 cells in 19 fields was 154 μm2 per osteoblast. The range for the fields was 136 to 177 μm2 per osteoblast. Four hundred cells were measured individually—for these the mean value per osteoblast was 143 μm2 with a standard deviation of 33. The daily rate of apposition over an 8 day period was 3.12 μm (standard deviation 0.22) measured by tetracycline marking of the mineral front. This gave a daily matrix production rate of approximately 470 μm3 per osteoblast.
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 14 (1974), S. 327-331 
    ISSN: 1432-0827
    Keywords: Bone ; Piezoelectricity ; Collagen ; Aging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract The piezoelectric constant of mature and immature bone (defined herein) has been measured in an effort to determine whether it varies with age. It was found that the average value of the piezoelectric constantd 14 of femur from three week old calves was 58% of the value of femur from three year old bulls. The results were interpreted to indicate qualitative differences in the corresponding collagen matrices. Mature human tibia from males ranging in age from 21 to 53 years of age showed a small but significant increase ind 14 with age. Some data concerning diseased human bone, and well-preserved human bone excavated in Peru are also presented.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 14 (1974), S. 333-337 
    ISSN: 1432-0827
    Keywords: Bone ; Materials ; Histology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Des métaux poreux et des céramiques sont implantés dans l'osin vivo et sont prélevés, après différents intervalles, pour étudier histologiquement la colonisation tissulaire. Les implants prélevés sont fixés avec les tissus environnants et inclus dans des epoxy-résines, de faible viscosité. Les échantillons sont coupés à l'aide d'une scie diamantée et fixés sur des lames pétrographiques, pour être ensuite amincis à environ 75 μm. Ils sont légèrement colorés au bleu de méthylène et à l'alizarine rouge S, qui donne un bon contraste entre tissus durs et mous et démontrent la présence d'os calcifié dans les implants poreux métalliques et céramiques.
    Abstract: Zusammenfassung Poröse Metall- und Keramikstücke wurden in vivo in Knochen implantiert und nach verschiedenen Intervallen entnommen, um histologisch zu untersuchen, wie weit sie ins Gewebe eingewachsen waren. Die entnommenen Implantate mit dem sie umgebenden Gewebe wurden fixiert, dehydriert und in ein niedrigvisköses Epoxy-Harz eingebettet. Die Proben wurden mit einer Diamantsäge in dicke Schnitte zerteilt, auf Steinscheiben zementiert und von Hand auf etwa 75 μm geschliffen. Sie wurden mit Methylenblau und Alizarin-Rot S schwach gefärbt; dies ergibt einen großen Kontrast zwischen Knochen und Weichgewebe und zeigt die Bildung von verkalktem Knochen innerhalb poröser Metall- und Keramik-Implantate deutlich.
    Notes: Abstract Porous metals and ceramics were implanted in bonein vivo and retrieved at intervals for histological evaluation of tissue ingrowth. Recovered implants with surrounding tissues were fixed, dehydrated and embedded in a low-viscosity epoxy resin embedding medium. The embedded samples were cut into thick sections with a diamond saw, cemented to petrographic slides, and hand-ground to approximately 75 μm. They were lightly stained with methylene blue and Alizarin Red S, which provided great contrast between the bone and soft tissues, and clearly demonstrated the formation of calcified bone within porous metal and ceramic implants.
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  • 4
    ISSN: 1432-0827
    Keywords: Osteogenesis ; Osteoinduction ; Bone ; Matrix ; Cell
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Bone matrix demineralized in 0.6 N HCl at 2° for 24 h and implanted in muscle in allogeneic rats possesses consistently reproducible bone morphogenetic activity. Experiments on implants of matrix, obtained from donors injected with3H-tyrosine or3H-tryptophan, or Na35SO4, suggest that bone morphogenetic property is a protein or apart of a protein that is (1) insoluble in buffer solutions, pH 3.6 and 5.0; (2) degraded in buffer solutions at pH 7.4 by an endogenous sulfhydryl-group neutral proteinase; (3) digested by trypsin at 15° within 8 h without solubilization of the helical regions, possibly even without degradation of the nonhelical ends of the bone collagen molecule, and without any loss of the periodic ultrastructure of the collagen fibrils; (4) degraded or removed by 0.1 N NaOH at 2° within 24 h without solubilization of collagen; (5) biologically active even after nitration of tyrosyl groups with tetranitromethane. The release of only one-third of the radioactivity with loss of nearly all yield of new bone by limited tryptic digestion of3H-borohydride-reduced matrix indicates that the bone morphogenetic response is the function of a non-collagenous component. Autoradiographs of implants of matrix with non-collagenous proteins labelled with3H-tryptophan,3H-tyrosine, or both3H-tyrosine and3H-phenyl-alanine demonstrate random dissemination of the radioactive constituents and no evidence of local transfer of labelled proteins or soluble protein derivatives. Hypothetically, the bone morphogenetic response is controlled by an insoluble acidic bone morphogenetic protein or polypeptide (BMP) and a soluble neutral proteinase (BMP-ase) resembling trypsin in activity except functionally more specific for BMP. Firmly bound but separable from bone collagen, BMP is one of many short-lived morphogenetic substances appearing and disappearing throughout embryonic development and persisting in postfetal life. Where the BMP receptor resides and how it activates cell mechanisms of differential repression and derepression of such genes as code for osteogenesis is unknown.
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  • 5
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    Calcified tissue international 15 (1974), S. 333-339 
    ISSN: 1432-0827
    Keywords: Vitamin D ; Bone ; Resorption ; Calcium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract A series of analogues of vitamin D have been tested for their ability to stimulate bone resorption in two test systems used previously to investigate the metabolites of vitamine D. These analogues were tested (a) by directly comparing their action on bone explants of mouse half-calvariain vitro, and (b) by injecting them into young mice and measuring the degree of resorptionin vitro when explants were prepared 18 hours after the injection. It is concluded that the key functional groups concerned with enhancing the activity of vitamin D3 are the 1α- and the 25-hydroxyl,both together; the cis ring structure for ring A appears necessary. 1α-Hydroxycholecalciferol (1α-OHD3) is about as active as 25-OHD3 in the direct test, but its potency is much nearer to that of 1,25-(OH)2D3 when tested by the second (indirect) method; it seems likely that 1α-OHD3 is converted into 1,25-(OH)2D3 in vivo. The results are discussed in relation to the designing of analogues for clinical and experimental use.
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  • 6
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    Calcified tissue international 16 (1974), S. 145-152 
    ISSN: 1432-0827
    Keywords: EHDP ; Bone ; Chemistry ; Serum ; Rabbits
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract The effects of disodium ethane-1-hydroxy-1,1-diphosphonate (EHDP) on bone and serum chemistry were investigated in adult rabbits. EHDP was administered by subcutaneous injection at doses of 0.25, 2.5 and 10 mg/kg body weight/day for of 28 days. Blood samples were obtained weekly from each rabbit and serum levels of total calcium, ionized calcium, inorganic phosphate and alkaline phosphatase were determined. At the end of the treatment period all rabbits were sacrificed and the tibiae removed for chemical analysis and histological evaluation. The effect of EHDP administration on serum chemistry was both dose- and time-related. The highest of the three doses, 10 mg/kg/day, resulted in a time-related decrease in total serum calcium. This dose also caused a rapid but transient reduction in serum ionized calcium. The effect of EHDP on serum inorganic phosphate was biphasic. Administration of 2.5 mg/kg/day resulted in a time-related elevation in this parameter, whereas the 10 mg/kg/day dose resulted in a time-related hypophosphatemic response. There were no significant drug-related changes in tibial fat-free dry weight, ash weight, total calcium or total phosphorus values. However, administration of 2.5 and 10 mg/kg/day EHDP resulted in increased osteoid tissue as measured histologically. These results are compared with data from other EHDP studies, and discussed in relation to the maturity and growth-state of the experimental animals.
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  • 7
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    Springer
    Calcified tissue international 16 (1974), S. 261-275 
    ISSN: 1432-0827
    Keywords: Dentine ; Bone ; Mineralization ; Density gradient fractionation ; Proteoglycans
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract In order to obtain enough material to analyse the organic matrix of mineralizing tissue a technique for preparative separation according to the degree of mineralization was developed. The method employs ultracentrifugation of powdered material in density gradients made from acetone and bromoform. The density range of the fractions is checked by refractive index measurements of the gradient medium. The amount of the material in the fractions is checked by weighing and their degree of mineralization is estimated by determining the Ca/N and P/N ratios. The homogeneity of the fractions is determined by soft X-ray microscopy. Isolated dissected microscopic bone structure (osteones and lamellar bone fragments) with different degrees of mineralization were fractionated in this way. Chromatography on Sepharose 2B of proteoglycans from costal cartilage exposed to an acetone-bromoform gradient revealed no effect of the gradient medium on the molecular size of the proteoglycans.
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  • 8
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    Calcified tissue international 14 (1974), S. 153-160 
    ISSN: 1432-0827
    Keywords: Lysosomes ; Bone ; Resorption ; Osteoclast
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Des techniques histochimiques de microscope photonique et électronique montrent que les ostéoclastes métaphysaires chez des rats “sans incisive” présentent des quantités plus importantes de phosphatase acide, d'acryl sulfatase et de trimétaphosphatase acide lysosomiales. L'activité en phosphatase lysosomiale à pH neutre est aussi plus élevée dans les ostéoclastes métaphysaires, sauf dans les cellules situées sous la métaphyse, où l'enzyme est absente. L'absence de résorption de la matrice organique semble en rapport avec l'absence de bordures en brosse et une absence d'enzyme lysosomiale extracellulaire. Malgré cette absence, une dissolution de cristaux inorganiques a été mise en évidence au microscope électronique, suggérant que la dissolution minérale est un processus distinct de la désintégration enzymatique de la matrice organique.
    Abstract: Zusammenfassung Histochemische Techniken für Licht- und Elektronenmikroskopie zeigten, daß metaphysäre Osteoklasten “Schneidezahl-loser” (SL) Ratten erhöhte Mengen von lysosomaler saurer Phosphatase, von Arylsulfatase und von saurer Trimetaphosphatase enthielten. Die Aktivität der lysosomalen Phosphatase bei neutralem pH war in den metaphysären Osteoklasten ebenfalls erhöht, außer in den Zellen direkt unterhalb der Wachstumsplatte, wo dieses Enzym nicht vorkam. Es konnte überhaupt keine Resorption der organischen Matrix festgestellt werden, was übereinzustimmen schien mit der Abwesenheit eines gekräuselten Saumes und einer gleichzeitigen Abwesenheit des extrazellulären lysosomalen Enzyms. Trotzdem wurde im Elektronenmikroskop das Verschwinden anorganischer Kristalle festgestellt, was darauf schließen läßt, daß die Auflösung des Minerals nicht derselbe Vorgang ist wie die enzymatische Auflösung der organischen Matrix.
    Notes: Abstract Histochemical techniques for light and electron microscopy showed that metaphyseal osteoclasts in “incisors absent” rats contained greater than normal amounts of lysosomal acid phosphatase, aryl sulfatase and acid trimetaphosphatase. Lysosomal phosphatase activity at neutral pH was also elevated in the metaphyseal osteoclasts except in those cells immediately beneath the growth plate, where this enzyme was absent. The failure of any discernable resorption of organic matrix appeared to correlate with the absence of a ruffled border and a concomittant absence of extracellular lysosomal enzyme. Despite this failure, electron microscopic evidence of inorganic crystal removal was noted, suggesting that mineral dissolution represents a separate process from the enzymatic breakdown of organic matrix.
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  • 9
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    Calcified tissue international 16 (1974), S. 13-36 
    ISSN: 1432-0827
    Keywords: Osteoclast ; Bone ; Resorption ; Crystals ; Organic-inorganic relationships
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract The organic-inorganic relationships in bone matrix undergoing osteoclastic resorption have been studied in rat tibial diaphyses using electron microscope techniques in an attempt to identify the steps of the resorption process. Results suggest that bone resorption occurs in two phases: the first, an extracellular phase, leads to bone matrix fragmentation and partial dissolution, and the second, an intracellular phase, to complete digestion of the breakdown products of the bone matrix. The first component of the bone matrix to be attacked by the osteoclast is the ground substance. This induces the release of the crystals lying between, and on, the collagen fibrils; any crystals lying within fibrils are released later, when the fibrils break up. As this stage proceeds, the collagen fibrils retain their normal intrinsic texture, but gradually loose their lateral aggregation, appearing as individual fibrils (some of them uncovered by crystals), mixed with fragments of fibrils and many free crystals. The loosened but otherwise structurally normal collagen fibrils, and their fragments, are strongly argyrophilic. Complete dissolution of the disaggregated fibrils occurs outside the cell, both in the resorption zone and in the initial portion of the channels of the ruffled border. The free crystals present in the resorption zone and those phagocytosed in cytoplasmic vacuoles are organic-inorganic structures, whose organic component (the crystal ghost) is, at least in part, of proteoglycan nature. Dissolution of inorganic material occurs within the cytoplasmic vacuoles of the osteoclasts. Results are viewed in relation to the process of bone resorption and, as far as crystal ghosts are concerned, to that of bone calcification. A tentative summary of the various steps involved in the mechanism of bone resorption is given.
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  • 10
    ISSN: 1432-0827
    Keywords: Bone ; Parathyroid ; 25-Hydroxycholecalciferol ; Adenosine 3′, 5′ cyclic monophosphate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Phenytoin, at a concentration which is known to inhibit parathyroid extract-induced bone resorptionin vitro, has been shown to have no significant effect on either the cyclic AMP content of four-day-old mouse calvaria which had been in tissue culture for 48 h or on the increase in cyclic AMP content occurring after the addition of parathyroid extract to the medium. Phenytoin has also been shown to be an effective inhibitor of bone resorptionin vitro induced by 25-hydroxycholecalciferol. These observations suggest that the inhibitory effect of phenytoin on parathyroid extract and hormone-induced bone resorption takes place beyond the cyclic AMP stage.
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  • 11
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    Calcified tissue international 16 (1974), S. 219-226 
    ISSN: 1432-0827
    Keywords: Bone ; Phosphate ; ATP ; Calcium ; Mitochondria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract An active constituent of the leaves ofSolanum malacoxylon (SM) is shown to promote calcium resorption and citrate production in embryonic chick frontal bone culturedin vitro. When injected into rats, SM reduces the ATP content of liver and kidneys. This phenomenon may be related to the ability of SM to stimulate mitochondrial ATPase activity at pH 9.4. SM significantly reduces the concentration of phosphate necessary to alter the uptake of calcium and respiration of siolated mitochondria. The data suggest that SM influences calcium and phosphate metabolism by affecting ion movements into and out of mitochondria.
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  • 12
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    Calcified tissue international 14 (1974), S. 251-255 
    ISSN: 1432-0827
    Keywords: Cartilage ; Bone ; Vitamin A ; Phosphatases
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Au cours d'une étude du cartilage épiphysaire de poulets normaux et déficients en vitamine A, la composition organique et l'activité phosphatasique du cartilage au repos, du cartilage en voie d'ossification et de l'os nouvellement formé ont été mesurées. Le cartilage en voie d'ossification et l'os nouvellement formé ont un contenu plus élevé en matériel inorganique, phosphate et collagène que le cartilage au repos. Une déficience en vitamine A provoque une augmentation du contenu en phospholipide de tous les trois tissus. Le cartilage au repos, en cas de déficience en vitamine A, présente, après homogénéisation et centrifugation, un surnageant dont l'activité en phosphatase alcaline et en glycérophosphatase est plus élevée que celle des témoins. Il semble que les effets enzymatiques de l'avitaminose A soient liés à des altérations de la membrane lysosomiale avec décharge de phosphatases. La minéralisation normale semble aussi faire intervenir une activité phosphatasique.
    Abstract: Zusammenfassung Diese Arbeit beschreibt Untersuchungen des Epiphysenknorpels bei normalen Küken und solchen mit Vitamin-A-Mangel. Die organische Zusammensetzung und die Phosphatase-Aktivität in ruhendem Knorpel, ossifizierendem Knorpel und neugebildetem Knochen wurden gemessen. Der ossifizierende Knorpel und der neugebildete Knochen hatten einen höheren Gehalt an anorganischem Material, an Phosphat und Kollagen als der ruhende Knorpel. Vitamin-A-Mangel führte zu einem erhöhten Phospholipidgehalt in allen drei Geweben. Nach Homogenisierung und Zentrifugierung fand sich im Überstand des ruhenden Knorpels von Vitamin-A-Mangelgewebe eine höhere alkalische Phosphatase- und Glycero-phosphatase-Aktivität als bei den Kontrollen. Es wird angenommen, daß die Wirkung des Vitamin A-Mangels auf die Enzyme im Zusammenhang steht mit der Schädigung der lysosomalen Membran, wobei Phosphatasen freigesetzt werden, und daß die normale Mineralisierung die Phosphatasen-Aktivität ebenfalls anregt.
    Notes: Abstract This paper reports studies of the epiphyseal cartilage in normal and vitamin A deficient chicks. The organic composition and the phosphatase activity in the resting cartilage, ossifying cartilage and new bone were measured. The ossifying cartilage and new bone had a higher content of inorganic material, phosphate and collagen than the resting cartilage. Vitamin A deficiency caused increase in the phospholipid content of all three tissues. The resting cartilage from vitamin A deficient tissue had, after homogenisation and centrifugation, a supernatant with an activity of alkaline phosphatase and glycerophosphatase higher than that in control samples. It is considered that effects of vitamin A deficiency on enzymes are related to defects of the lysosomal membrane with release of phosphatases, and that normal mineralisation also involves phosphatases activity.
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  • 13
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    Calcified tissue international 14 (1974), S. 283-289 
    ISSN: 1432-0827
    Keywords: Sodium fluoride ; Osteoporosis ; Bone ; Strength ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé L'utilisation thérapeutique de fluorure de sodium a été recommandée dans le traitement de diverses maladies osseuses ostéopéniques. Cet emploi est basé principalement sur les effects ostéosclérotiques bien connus du fluorure de sodium, mais on connait mal son effet sur la force de résistance osseuse. L'influence de diverses concentrations de fluorure de sodium sur la force de résistance osseuse de jeunes rats soumis à des régimes riches et pauvres en calcium a été étudiée. L'administration de fluorure de sodium augmente le diamètre osseux, indiquant une stimulation de la formation de l'os périosté, mais la force de résistance osseuse est réduite ou non modifiée par l'ingestion de fluor.
    Abstract: Zusammenfassung Die therapeutische Verwendung von Natriumfluorid ist für eine Anzahl von Knochenmangel-Krankheiten empfohlen worden. Die Empfehlungen basieren hauptsächlich auf den bekannten osteosklerotischen Wirkungen von Natriumfluorid; über dessen Effekt auf die Knochenstärke ist wenig bekannt. In dieser Arbeit wurde der Einfluß verschiedener Konzentrationen von Natriumfluorid auf die Knochenstärken von wachsenden Ratten mit hoher und niederer Calciumeinnahme untersucht. Die Verabreichung von Natriumfluorid erhöhte den Knochendurchmesser, was auf eine Stimulierung der Periostbildung hinwies, die Knochenstärke wurde jedoch durch Fluorideinnahme herabgesetzt oder nicht beeinflußt.
    Notes: Abstract The therapeutic use of sodium fluoride has been recommended in a variety of osteopenic bone diseases. The recommendations are based mainly on the known osteosclerotic effects of sodium fluoride and little information is available as to its effect on bone strength. The influence of various concentrations of sodium fluoride on bone strength in growing rats on high and low calcium diets was studied. The administration of sodium fluoride increased bone diameter, indicating stimulation of periosteal bone formation, but bone strength was reduced or not affected by fluoride ingestion.
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  • 14
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    Calcified tissue international 14 (1974), S. 291-299 
    ISSN: 1432-0827
    Keywords: Bone ; Collagenase ; Lysozyme
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Du lysozyme de blanc d'œuf, ainsi que des protéines basiques, telles que de l'histone et une base dépourvue de protamine, semblent inhiber la collagénase osseuse de souris. L'inhibition de collagénase osseuse de souris par le lysozyme est mise en évidence lorsque l'activité de la collagénase est étudiée en utilisant du collagène comme substrat à l'état solide, mais non lorsque le collagène est utilisé en solution. D'autre part, l'inhibition de l'activité en collagénase par l'histone et une base dépourvue de protamine est observée dans les deux systèmes. L'inhibition de collagénase ossuese de souris par des molécules polyanioniques est intéressante, étant donné que des travaux antérieurs ont montré que plusieurs molécules polyanioniques telles que l'héparine, le sulfate de dextrane et l'acide polyethylenesulfonique augmentent l'activité de collagénase osseuse de souris dans les mêmes conditions expérimentales. Comme le lysozyme est largement présent dans les tissus conjonctifs et que sa concentration carie avec l'ampleur du remaniement tissulaire, l'inhibition de la collagénase osseuse de souris suggère un role éventuel dans la régulation de la dégradation du collagène, pendant le remaniement des tissus collagéniquesin vivo au cours d'états normaux et pathologiques.
    Abstract: Zusammenfassung Lysozyme aus Hühnereiweiß sowie Basis-Proteine, wie z. B. Histon und Protamin-freie Basen, erwiesen sich als Hemmer der Mäuseknochen-Kollagenase. Diese Hemmung durch Lysozym wurde festgestellt, wenn für die Messung der Kollagenase-Aktivität Kollagen in Substanz als Substrat verwendet wurde, nicht aber, wenn das Substrat aus gelöstem Kollagen bestand. Andererseits wurde die Hemmung der Kollagenase-Aktivität durch Histon und Protamin-freie Basen in beiden Versuchssystemen festgestellt. Die Hemmung von Mäuseknochen-Kollagenase durch polykationische Moleküle ist interessant, vor allem im Hinblick auf frühere Feststellungen, daß mehrere polyanionische Moleküle, wie Heparin, Dextransulfat und Polyaethylensulfonsäure, die Aktivität der Mäuseknochen-Kollagenase unter denselben experimentellen Bedingungen erhöhen. Da Lysozym in Bindegeweben überall verteilt ist und da dessen Konzentration mit der Neubildungsrate des Gewebes variiert, läßt die Hemmung der Mäuseknochen-Kollagenase durch Lysozym dessen mögliche Rolle in der Regulierung des Kollagenabbaues vermuten, und zwar während der Neubildung von Kollagengeweben in vivo in normalen und pathologischen Zuständen.
    Notes: Abstract Egg white lysozyme, as well as basic proteins such as histone and protamine-free base, were found to inhibit mouse bone collagenase. The inhibition of mouse bone collagenase by lysozyme was detected when the activity of the collagenase was assayed using collagen as the substrate in the solid state, but not when the collagenase activity was assayed using collagen in solution as the substrate. On the other hand, the inhibition of collagenase activity by histone and protamine-free base was observed in both assay systems. The inhibition of mouse bone collagenase by polycationic molecules is interesting in light of previous findings that several polyanionic molecules, such as heparin, dextran sulfate and polyethylenesulphonic acid, enhance the activity of mouse bone collagenase under the same experimental conditions. Since lysozyme is widely distributed in connective tissues and its concentration varies with the rate of tissue remodeling, the inhibition of mouse bone collagenase by lysozyme suggests its possible role in the regulation of collagen degradation during the remodeling of collagenous tissuesin vivo during normal and pathological states.
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  • 15
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    Calcified tissue international 15 (1974), S. 11-20 
    ISSN: 1432-0827
    Keywords: Bone ; Growth ; Resorption ; Caudal ; Vertebra ; Fluorescence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Une méthode de mesure de l'apposition et de la résorption osseuse est mise au point au niveau de la septième vertèbre caudale de jeunes rats, pesant 25–90 g, pendant la période de croissance. Cette pièce osseuse a des avantages certains par rapport à d'autres localisations, car elle est symétrique en coupe transversale et non affectée par des forces corticales. En utilisant trois marqueurs d'os différents, fluorescents en lumière ultra-violette, administrés à des intervalles de 3, 5 ou 7 jours, les modifications de croissance sont observées sur des coupes transversales centrales, non décalcifiées, de la septième vertèbre caudale. Une formation osseuse linéaire se développe à une vitesse moyenne de 10.0 μ/jour et une résorption linéaire de 6.1μ/jour est notée. Pendant la période de croissance observée, la formation osseuse s'observe exclusivement à la surface du périoste et la résorption se fait le long de la surface de l'endoste. A ce niveau l'os est totalement résorbé, chez des animaux de 25 g en 22–26 jours. Il semble que chez des animaux plus âgés, une formation osseuse endostée se développe rendant alors impossible toute étude prolongée dans cette région.
    Abstract: Zusammenfassung Es wird eine Methode zur Messung der Knochenbildungs- und Resorptionsgeschwindigkeiten im siebten Caudalwirbel junger Ratten während ihrer Wachstumsperiode von 25–90 g beschrieben. Dieser Knochen hat gegenüber jenen, die vorgängig untersucht wurden, den großen Vorteil, in transversalen Schnitten symmetrisch und unbeeinflußt von kortikalen Unregelmäßigkeiten zu sein. Die Art der Wachstumsveränderungen wurden an nichtentkalkten zentralen Transversalschnitten der siebten Caudalwirbeln bestimmt; dazu wurden drei verschiedene, farbige, im UVbereich fluoreszierende Knochenmarkierungssubstanzen verabreicht und zwar in 3-, 5- oder 7tägigen Intervallen. Die lineare Knochenbildung fand mit einer mittleren Geschwindigkeit von 10,0 μ pro Tag statt, die lineare Knochenresorption mit einer solchen von 6,1 μ pro Tag. Während der untersuchten Wachstumsperiode fand die Knochenbildung ausschließlich an der Periostoberfläche und die Knochenresportion an der endostalen Oberfläche statt. Der Knochen, der beim 25 g schweren Tier an diesem Ort vorlag, verschwand durch die endostale Resorption innerhalb von 22–26 Tagen
    Notes: Abstract A method for measuring bone formation and resorption rates in the seventh caudal vertebra of young rats during the growth period from 25–90 g is reported. This bone site has unique advantages over those previously studied, being symmetrical in transverse section and uncomplicated by cortical drift. Utilising three different coloured ultraviolet fluorescent bone labelling substances administered at either 3, 5 or 7 day intervals, the nature of growth changes was determined from undecalcified central transverse sections of the seventh caudal vertebrae. Linear bone formation occurred at a mean rate of 10.0 μ/day and linear bone resorption at 6.1 μ/day. During the growth period studied, bone formation occurred exclusively on the periosteal surface and bone resorption on the endosteal surface. Bone existing in this site in 25 g animals was completely removed by endosteal resorption within 22–26 days. Evidence exists that in older rats endosteal bone formation occurs and renders the site unsuitable for long term studies.
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    Calcified tissue international 15 (1974), S. 315-324 
    ISSN: 1432-0827
    Keywords: Bone ; Mineral ; Osteogenesis ; Interference microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract A method based on tetracycline labeling was developed for selecting, in frozen sections of fetal mouse femur, bone foci approximately 6, 24, 48 and 72 h of age. Microinterferometric measurements of these foci permitted a calculation of the effective thickness (t) and refractive index (n) of each focus. After demineralizing the sections by a method which left the organic portion of the bone intact, the foci were re-measured andt andn of the organic compartment of each focus were determined;t andn of the mineral compartment were calculated by difference. A sharp decrease and subsequent rise in then of whole bone occurred between 6 and 48 h. These changes derived from the mineral compartment, and were thought to have resulted from the formation of amorphous calcium phosphate and hydroxyapatite, respectively. The mineral present in 6 h foci, however, was believed to be some precursor of amorphous calcium phosphate.
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    Calcified tissue international 15 (1974), S. 329-332 
    ISSN: 1432-0827
    Keywords: Microradiography ; Bone ; X-ray
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract A low cost, self-contained, commercially available, X-ray apparatus which possesses the essential qualifications necessary to produce high resolution microradiographs of undecalcified bone is described. The widespread current use of this machine in pathology laboratories may make purchase of such a unit optional.
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    Calcified tissue international 16 (1974), S. 73-88 
    ISSN: 1432-0827
    Keywords: Dentine ; Bone ; Histocytochemistry ; Physiological Calcification
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    Notes: Abstract Histochemical methods were used to detect differences in amino acid reactive groups between bone and osteoid, dentine and predentine. Three major differences were found: Predentine and osteoid contained more reactive sulphydryls than their mineralized counterparts. The greatest reaction for this reactive group was obtained at the mineralizing front. Dentine and bone contained a complex between amino and carboxylic acid groups; predentine and osteoid did not have this complex and carboxylic acid residues were less in these tissues. Dentine and bone contained much greater amounts of histidine or a histidine-like component than did predentine and osteoid. It is proposed that these differences are involved in initiation of mineralization.
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    Calcified tissue international 16 (1974), S. 169-182 
    ISSN: 1432-0827
    Keywords: Histochemistry ; Alkaline phosphatases ; Calcification ; Bone ; Teeth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Activity of alkaline phosphatases in unfixed cold microtome setions from the lower first molar area of newborn mice was recorded by histochemical methods. A substrate specificity test included the following phosphate compounds: ATP, CTP, GTP, UTP, ADP, AMP, GP, PPi, MDP and naphthol AS-TR phosphate. Intense staining was obtained in osteoblasts, stratum intermedium of the enamel organ and odontoblasts with all the substrates, except PPi and MDP. Staining of skeletal muscle fibres was obtained only with triphosphates as substrates. Addition of-SH groups decreased the hydrolysis of triphosphate compounds in cells involved in mineralization while the hydrolysis of monophosphate was inhibited. In contrast triphosphatase activity in striated muscle was enhanced when-SH compounds were added. Demineralization with EDTA diminished the cytoplasmic staining but induced a nuclear staining in hard tissue forming cells when triphosphates were used as substrates. No cytoplasmic and only slight nuclear staining was seen with GP or AMP as substrates. The triphosphate hydrolyzing capacity of tongue muscle fibres was, however, increased after the decalcification treatment. Addition of Mg2+ ions to the incubation media distinctly lowered the hydrolysis of triphosphates in the investigated tissues whereas the hydrolysis of ADP, AMP, GP and naphthol AS-TR phosphate remained unchanged. In view of the findings the triphosphatase activities at alkaline pH of muscle fibres and of cells related to hard tissue formation are considered to be due to activity of separate enzymes. The orthophosphate liberating enzyme activities at alkaline pH in osteoblasts, stratum intermedium and odontoblasts may be expressions of the catalytic functions of one common enzyme. Furthermore, the results indicate that CaATP might be the substrate used by the alkaline ATPase in mineralizing areas.
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    Calcified tissue international 16 (1974), S. 239-250 
    ISSN: 1432-0827
    Keywords: EHDP ; Bone ; Collagen ; Histology ; Bone chemical analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract The purpose of this study was to determine the short-term effects of various systemic doses of disodium ethane-1-hydroxy-1,1-diphosphonate (EHDP) on bone organic matrix and to relate these effects to the corresponding dose-related changes in bone mineral. EHDP was administered daily by subcutaneous injection at doses of 0.25, 2.5 and 40 mg/kg body weight for periods of one and two weeks. At both time intervals, rat tibiae were quantitatively analyzed for mineral content (ash, calcium and phosphorus) and for organic matrix content (matrix weight, nitrogen and certain amino acids). The latter data were correlated with semiquantitative histological analyses of the tibiae. Results of this study demonstrate that the short term effects of EHDP on bone chemistry and histology are variable and depend on the systemic dose and the duration of treatment. Systemic doses of 0.25 and 2.5 mg/kg EHDP following daily administration for one week resulted in transitory decreases in bone mineral content compared to controls. Following two weeks of treatment, both of these dose levels resulted in increased bone mineral content and, in addition, the 2.5 mg/kg dose resulted in tibiae which contained more organic matrix compared to control bones. In contrast to the low dose effects, a high systemic dose of EHDP—e.g. 40 mg/kg administered daily for 1 or 2 weeks—appears to act solely by inhibiting mineralization of newly-formed matrix.
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    Calcified tissue international 14 (1974), S. 31-48 
    ISSN: 1432-0827
    Keywords: Bone ; Cartilage ; Calcification ; Collagen ; Phosphate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Une méthode pour l'étude de la croissance des os longs de foetus de rat, en culture d'organe, dans un milieu chimiquement défini, a été mise au point. Les extrémités cartilagineuses et les parties centrales de l'os sont analysées séparément pour leur croissance et minéralisation en étudiant leur contenu en collagène, calcium et phosphate, poids sec, et incorporation de proline marquée en hydroxyproline. La croissance et la minéralisation des parties centrales osseuses sont plus lentes dans un milieu chimiquement défini qu'in vivo. La croissance peut être accélérée en ajoutant au milieu des acides aminés non essentiels, de l'albumine ou du sérum. Les extrémités cartilagineuses présentent une augmentation plus importante en poids et contenu en collagène que les parties centrales et l'adjonction de diverses substances a moins d'effet sur la croissance. La croissance et la minéralisation des parties centrales sont augmentées en élevant la concentration du milieu en phosphate de 1.5 à 4.5 mM, avec ou sans adjonction de sérum ou d'albumine. A une concentration faible de calcium (0.5 mM), la croissance et la minéralisation des parties centrales sont arrêtées. A une concentration faible en magnésium (0.5 mM), la minéralisation est augmentée, mais la croissance est arrêtée.
    Abstract: Zusammenfassung Es wird eine Methode beschrieben, mit welcher das Wachstum der Röhrenknochen von Rattenembryos in einem chemisch bestimmten Medium in Organkultur untersucht werden kann. Die Knorpelenden und Knochenschäfte wurden gesondert auf Wachstum und Mineralisation geprüft, indem Collagen-, Calcium- und Phosphatgehalt, das Trockengewicht und der Einbau von markiertem Prolin in Hydroxyprolin gemessen wurden. Wachstum und Mineralisation des Knochenschaftes waren langsamer in einem chemisch bestimmten Medium als in vivo. Das Wachstum konnte beschleunigt werden, indem dem Medium nicht-essentielle Aminosäuren, Albumin oder Serum beigegeben wurden. Die Knorpelenden zeigten eine viel stärkere Zunahme an Gewicht und Collagengehalt als die Schäfte, und Anreicherung des Mediums hatte weniger Wirkung auf ihr Wachstum. Das Wachstum und die Mineralisation der Knochenschäfte nahmen zu, wenn die Phosphatkonzentration im Medium zwischen 1,5 und 4,5 mM erhöht wurde, und zwar unabhängig davon, ob dem Medium Serum oder Albumin beigegeben wurde oder nicht. Bei niederer Calciumkonzentration (0,5 mM) im Medium wurden Wachstum und Mineralisation der Knochenschäfte beeinträchtigt. Bei niedriger Magnesiumkonzentration (0,5 mM) wurden die Mineralisation erhöht, das Wachstum hingegen gehemmt.
    Notes: Abstract A method for studying the growth of fetal rat long bones in a chemically defined medium in organ culture is described. Cartilage ends and bone shafts were analyzed separately for growth and mineralization by measuring the collagen, calcium, and phosphate content, dry weight, and incorporation of labeled proline into hydroxyproline. Growth and mineralization of the bone shaft were slower in a chemically defined medium thanin vivo. Growth could be enhanced by supplementation of the medium with non-essential amino acids, albumin or serum. Cartilage ends showed a greater increase in weight and collagen content than the shafts, and medium supplements had less effect on their growth. Bone shaft growth and mineralization were enhanced by increasing medium phosphate concentration over a range of 1.5 to 4.5 mM whether or not the medium was supplemented with serum or albumin. At a low medium calcium concentration (0.5 mM) bone shaft growth and mineralization were impaired. At a low magnesium concentration (0.5 mM) mineralization was enhanced, but growth was impaired.
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    Calcified tissue international 14 (1974), S. 83-86 
    ISSN: 1432-0827
    Keywords: Bone ; Reproductive cycle ; Pigeons ; Amorphous ; Crystalline
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Une étude de diffraction aux rayons X, au cours du cycle de ponte d'oeufs de pigeon, a été entreprise pour évaluer les modifications de la proportion entre les phases de phosphate de calcium amorphe et apatitique. La partie médullaire du fémur de pigeon est totalement résorbée au cours du cycle de reproduction. Au cours de ce processus, l'os contenant plus de phosphate de calcium amorphe est résorbé avant celui qui est riche en cristaux. Ainsi l'os à contenu amorphe plus élevé est métaboliquement plus actif que l'os riche en cristaux. L'os médullaire qui peut être induit chez le pigeon mâle par traitement aux oestrogènes, ressemble, au point de vue diffraction aux rayons X, à l'os médullaire des femelles au début du cycle de reproduction.
    Abstract: Zusammenfassung Mittels Röntgen-Diffraktion wurden die Veränderungen in den prozentualen Mengen der amorphen und der kristallinen Calciumphosphat-Phasen im Femur der Taube während des Eierlegens untersucht. Der medulläre Teil des Taubenfemur wird während des Fortpflanzungscyclus vollständig resorbiert. Dabei wird der Teil des Knochens, der mehr amorphes Calciumphosphat enthält, vor dem kristallreichen Teil resorbiert. Daraus folgt, daß der Stoffwechsel des Knochens mit höherem amorphem Gehalt aktiver ist als derjenige des Knochens mit höherem kristallinem Gehalt. Weiter konnte mittels Röntgendiffraktion festgestellt werden, daß der medulläre Knochen, welcher in männlichen Tauben durch Oestrogenbehandlung erzeugt werden kann, dem weiblichen medullären Knochen am Anfang des Fortpflanzungscyclus gleicht.
    Notes: Abstract This is an X-ray diffraction study of the changes in the proportional amounts of the amorphous and apatitic calcium phosphate phases in pigeon femur during the egg-laying cycle. The medullary portion of pigeon femur is completely resorbed in the reproductive cycle. In this process the portion of bone which is higher in amorphous calcium phosphate is resorbed before the crystal-rich portion. Thus, bone with a higher amorphous content is more metabolically active than more crystalline bone. Finally, medullary bone which can be produced in male pigeons by estrogen treatment was found by X-ray diffraction to resemble female medullary bone at the beginning of the reproductive cycle.
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    Calcified tissue international 14 (1974), S. 49-58 
    ISSN: 1432-0827
    Keywords: Glycosaminoglycans ; Intracellular ; Chondrocytes ; Cartilage ; Embryonal ; Bone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Les glycosaminoglycanes acides de chondrocytes isolés, en suspension, sont étudiés. La matrice extracellulaire est isolée par traitement successif à la trypsine et à la collagénase d'os d'embryons de poulet, âges de 15 à 17 jours. Après digestion à la papaïne et élimination des acides nucléïques par traitement à la DNAse et à la RNAse, les glycosaminoglycanes sont précipités par le CPC et isolés sous la forme de leur sel sodique. Les analyses des propriétés de solubilité du CP glycosaminoglycane par le microfractionnement d'Antonopoulos et coll. (1964) révèlent la présence de glycosaminoglycanes intracellulaires de poids moléculaire et/ou de densité de charge nettement plus faibles que ceux de la matrice extracellulaire. Sur des électrophorèses de microzones, une petite partie des glycosaminoglycanes intracellulaires isolées présente une mobilité similaire à celle des solutions témoins de sulfate de chondroitine, alors que la portion la plus importante ne se déplace qu'à mi-distance de l'acide hyaluronique et montre une large trainée, indiquant une faible charge négative. Ce fait semble dû à une perte de l'influence de régulation des composants matriciels éliminées, sur la synthèse des glycosaminoglycanes et au rejet dans le milieu de glycosaminoglycanes initialement synthétisé. Pour la première fois, une faible quantité d'acide hyaluronique intracellulaire est mise en évidence par une mobilité électrophorétique typique.
    Abstract: Zusammenfassung Saure Glykosaminoglycane von isolierten Chondrocyten in Suspension wurden untersucht, und die extracelluläre Matrix von 15–17 Tage alten Knochen von Kükenembryos wurde durch die aneinanderfolgende Behandlung mit Trypsin und Collagenase erhalten. Nach der Papain-Verdauung und Beseitigung der Nucleinsäuren mittels DNS- und RNSase-Behandlung wurden die Glykosaminoglycane mit CPC gefällt und als Natriumsalz isoliert. Untersuchungen der Löslichkeit der CP-Glykosaminoglycane mittels des Mikrofraktionierungsverfahrens von Antonopouloset al. (1964) zeigten intracelluläre Glykosaminoglycane mit meist niedrigerem Molekulargewicht und/oder niedrigerer Ladungsdichte als diejenigen der extracellulären Matrix. In der Mikro-Zonen-Elektrophorese zeigte nur ein kleiner Teil der isolierten intracellulären Glykosaminoglycane eine Mobilität, die dem Standard des Chondroitinsulfats entsprach. Der größte Teil legte nur die halbe Distanz der Hyaluronsäure zurück und zeigte breites “Tailing”, was auf eine niedrigere negative Ladung hindeutet. Die Ursache dafür wurde interpretiert als Verlust eines regulierenden Einflusses der entfernten Matrixkomponenten auf die Glykosaminoglycan-Synthese und als Abgabe ursprünglich synthetisierter Glykosaminoglycane in das Medium. Es wurde erstmals, anhand der typischen elektrophoretischen Beweglichkeit, eine kleine Menge von intracellulärer Hyaluronsäure nachgewiesen.
    Notes: Abstract Acid glycosaminoglycans were studied from isolated chondrocytes in suspension and the extracellular matrix obtained by sequential trypsin and collagenase treatment of 15- to 17-day-old embryonic chick bone. After papain digestion and removal of the nucleic acids by treatment with DNAse and RNAse, the glycosaminoglycans were precipitated by CPC and isolated as their sodium salt. Analyses of the CP-glycosaminoglycan solubility properties with the microfractionation procedure of Antonopouloset al. (1964) showed intracellular glycosaminoglycans of predominantly lower molecular weight and/or charge density than those of extracellular matrix. On micro-zone electrophoresis, only a minor part of the isolated intracellular glycosaminoglycans showed a mobility similar to that of the chondroitin sulphate standards while the major part moved only half the distance of hyaluronic acid and showed broad tailing, indicating a low negative charge. This was considered to be due to loss of a regulatory influence of the removed matrix components upon glycosaminoglycan synthesis and to release of originally synthesized glycosaminoglycans into the medium. For the first time, a small amount of intracellular hyaluronic acid was shown by typical electrophoretic mobility.
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    Calcified tissue international 14 (1974), S. 161-168 
    ISSN: 1432-0827
    Keywords: Diphosphonates ; Osteoid Synthesis ; Hydroxyproline ; Bone ; Formation-Resorption
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Deux diphosphonates, à savoir l'éthane-1-hydroxy-1,1-diphosphonate (EHDP) et le dichlorométhane diphosphonate (Cl2MDP), inhibentin vitro la résorption osseuse qui est stimulée soit par la parathormone ou par voie intrinsèque dans un système de culture d'os en remaniement. Alors que le Cl2MDP est plus efficace que l'EHDP dans l'inhibition de la résorption, ce fait semble en rapport avec une diminution de le formation de tissu ostéoide. Il s'en suit une diminution biochimique et morphologique marquée du remaniement osseux avec le Cl2MDP à une concentration équivalent à 10 μg de phosphore/ml de milieu de culture. La différence d'activité entre l'EHDP et le Cl2MDP peu être liée à leur affinité relative pour les surfaces du minéral osseux et, par suite, à leur concentration effective dans la fluide extracellulaire osseux. Les diphosphonates pourraient aussi affecter l'os indirectement si l'on admet que le degré de minéralisation de la matrice est important pour l'induction et la régulation de l'activité ostéoblastique dans l'os en voie de remaniement.
    Abstract: Zusammenfassung Zwei Diphosphonate, Aethan-1-hydroxy-1,1-diphosphonat (EHDP) und Dichloromethylen-Diphosphonat (Cl2MDP) hemmen in vitro die Knochenresorption. Diese wird verfolgt entweder mittels Stimulierung durch PH oder in einem Kultursystem, in welchem normale Knochenneubildung stattfindet. Während Cl2MDP die Resorption wirksamer hemmt als EHDP, scheint es ebenfalls eine Verminderung der Osteoidbildung zu verursachen. Dies bewirkt eine deutliche biochemische und morphologische Herabsetzung der Knochenneubildung, bei einer Cl2MDP-Konzentration von 10 μg Phosphor/ml Kulturmedium. Die unterschiedliche Wirksamkeit von EHDP und Cl2MDP läßt sich wahrscheinlich auf ihre verschiedenen Affinitäten zu der Oberfläche des Knochenminerals und somit auf ihre tatsächliche freie Konzentration in der extracellulären Flüssigkeit des Knochens zurückführen. Ausgehend von der Annahme, daß die Anregung und Regulierung der Osteoblasten-Aktivität bei der Knochenneubildung vom Ausmaß der Matrix-Mineralisation bestimmt wird, läßt sich die Vermutung aufstellen, daß die Diphosphonate die Knochenbildung auch indirekt beeinflussen können.
    Notes: Abstract Two Diphosphonates, ethane-1-hydroxy-1,1-diphosphonate (EHDP) and dichloromethylene diphosphonate (Cl2MDP) inhibitin vitro bone resorption, which is either stimulated by parathyroid hormone or intrinsic in a bone remodeling culture system. While Cl2MDP is more effective than EHDP in inhibiting resorption, it also appears to result in a related diminution in osteoid formation. This effect causes a marked biochemical and morphological depression of bone remodelling with Cl2MDP at a concentration equivalent to 10-μg-phosphorus/ml of culture medium. The difference in activity between EHDP and Cl2MDP may be related to their relative affinities for the bone mineral surfaces and hence their effective free concentration in the bone extracellular fluid. It is hypothesized that diphosphonates may also affect bone formation indirectly if one assumes that the degree of mineralization of the matrix is important in the induction and regulation of osteoblastic activity in remodelling bone.
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    Calcified tissue international 14 (1974), S. 195-210 
    ISSN: 1432-0827
    Keywords: Bone ; Fossil bone ; Bone resorption ; Boring channels ; Fungi
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé L'action ostéoclasique exercée par un champignon appartenant au genreMucor sur des os inhumés a été étudiée au point de vue morphologique. L'érosion ossuse donne lieu à des cavités et à des canalicules de percement, dont les parois apparaissent régulièrement calcifiées jusqu'a l'interface avec le champignon, ce qui veut dire que la réabsorption intéresse en même temps la matrice organique et les cristallites. Au contraire des ostéoclastes, la membrane du champignon ne montre jamais un bord en brosse au niveau des points où elle se met en contact avec le tissu osseux. De même l'examen au microscope électronique ne décele apparemment aucun passage de matériel dans l'épaisseur de la membrane ainsi que dans le protoplasme du champignon, ce qui porte à admettre qu'un processus de solubilisation a lieu au préalable. Seulement dans le cas où le champignon présente des phénomènes de vieillissement, des données font prévoir la libération d'une substance capable de décalcifier la matrice organique. Tous les résultats ci-dessu sont discutés de façon analytique et comparés à ceux fournis par les canalicules de percement des os fossiles.
    Abstract: Zusammenfassung Die osteoklastische Aktivität eines der Mucor-Gattung angehörenden Pilzes auf begrabene Knochen wurde morphologisch untersucht. Die Wirkung dieses Pilzes in der Knochenerosion führt zu Resorptionshöhlen und Bohrkanälen, deren Wände scharf und bis zur Oberfläche gut verkalkt sind; das bedeutet, daß die Knochenresorption gleichzeitig die Kristalliten und die organische Matrix in Mitleidenschaft zieht. Im Gegensatz zu den normalen Osteoklasten zeigt die Membran des Pilzes an den Berührungsstellen mit dem Knochengewebe keinen Bürstensaum. Ebenfalls läßt eine elektronenmikroskopische Untersuchung keinen Durchgang von Substanzen durch die Membran und das Protoplasma des Pilzes erkennen, so daß man annehmen muß, daß vorher ein Auflösungsprozeß stattgefunden hat. Die Vermutung liegt nahe, daß eine Substanz, welche den anorganischen Knochenanteil aufzulösen vermag, sich
    Notes: Abstract A morphological investigation has been carried out on the osteoclastic activity revealed by a fungus of theMucor genus on buried bone. The hallmark of its activity in eroding bone is the finding of resorption pits and boring channels whose walls are sharp and well calcified up to the free edge, suggesting that bone resorption affects crystallites and the organic matrix simultaneously. Unlike normal osteoclastic cells, the fungal membrane in contact with the bone shows no brush border. As the electron microscope reveals no migration of material to the fungal membrane and its protoplasm, the view is expressed that the material which reaches the fungus has been previously solubilized. There is good reason for supposing that a substance capable of solubilizing the inorganic bone fraction spreads freely through bone tissue, decalcifying the matrix, where, but only where, hyphae show the effects of ageing. All the findings are thoroughly discussed and compared with those furnished by the boring channels in fossil bone.
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    Calcified tissue international 14 (1974), S. 245-249 
    ISSN: 1432-0827
    Keywords: Bone ; Repair ; Histology ; Implant
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Um modèle expérimental, destiné à l'étude de la cicatrisation osseuse, est mis au point. Il permet d'obtenir du tissu osseux pour des études qualitatives et quantitatives. Des tubes de nylon sont implantés dans l'alvéole d'incisives extraites de cobayes. Une étude histologique de coupes longitudinales montrent que les implants de nylon ne retardent pas la cicatrisation des lésions osseuses et contiennent suffisamment de tissus pour des études biochimiques.
    Abstract: Zusammenfassung Es wurde ein Modellsystem zum Studium der Knochenwiederherstellung entwickelt, mit Hilfe dessen man von dem sich wiederbildenden Knochengewebe Proben für die qualitative und quantitative Bestimmung entnehmen kann. Dazu wurden in die Alveolen extrahierter Schneidezähne von Meerschweinchen Nylonschläuchlein eingelegt. Die histologische Untersuchung von Längsschnitten zeigte, daß die Nylonimplantate den Wiederherstellungsprozeß des Knochendefektes nicht verzögerten, daß sie herauspräpariert werden konnten und genügend Gewebe enthielten, um für biochemische Untersuchungen verwendet zu werden.
    Notes: Abstract A model system for the study of bone repair has been developed which allows the recovery of repairing osseous tissue for qualitative and quantitative evaluation. Nylon tubes were implanted in the alveoli of extracted incisors in guinea pigs. A histological study of longitudinal sections showed that the nylon implants did not delay the reparative processes of the bony defect, could be dissected out and contained sufficient tissue to be used in biochemical studies.
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    Calcified tissue international 15 (1974), S. 45-54 
    ISSN: 1432-0827
    Keywords: Bone ; Fluoride ; Microhardness ; Mineralization ; Strength
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    Topics: Biology , Medicine , Physics
    Notes: Abstract Microhardness was measured in sampling sites in the tibial diaphysis of control rats that received less than 1 ppm fluoride in the drinking water, and experimental rats that received 30, 90 and 120 ppm fluoride in the drinking water for 17 days. The latter dose was toxic, as evidenced by a decreased final body weight in this group. By means of tetracycline labelling, it was possible to measure bone hardness in four zones of increasing bone age: I) 3 days, II) 8 days, III) 13 days and IV) 22 days. Zones I through III represented bone formed during fluoride treatment, and Zone IV bone formed before fluoride treatment. In the control group, microhardness increased from Zone I to II, probably because mineral concentration was relatively low in Zone I, and remained constant thereafter. In the 90 and 120 ppm fluoride-treated groups, maximum microhardness was not achieved until Zone III. This delay was probably due to the fact that fluoride in large doses inhibits the rate of mineralization. In the 30 ppm fluoride-treated group, there was no delay in achievement of maximum microhardness; microhardness values in Zones I and III were greater than those in control animals, and microhardness in Zone III was higher than that in Zone IV. These results show that: 1) bone microhardness is increased in bone formed during fluoride treatment in rats given 30 ppm fluoride in the drinking water, 2) toxic doses of fluoride delay, but do not prevent achievement of normal maximum microhardness, and 3) changes in microhardness are seen only in bone formed during fluoride treatment.
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    Calcified tissue international 15 (1974), S. 71-76 
    ISSN: 1432-0827
    Keywords: Bone ; Calcium ; Deficiency ; Osteoporosis ; Species
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    Topics: Biology , Medicine , Physics
    Notes: Abstract 21-day-old rats and mice were fed a low-calcium diet (0.02% Ca) or a normal diet (0.5% Ca) for two weeks. Administration of the low-calcium diet resulted in greater decreases in femur ash content and serum calcium in rats than in mice. Microscopic examination revealed that metatarsal bones from a majority of the rats fed a low-calcium diet displayed moderate or severe osteoporotic changes whereas bones from mice were either normal or displayed only slight osteoporotic changes under the same experimental conditions. These results indicate that mice are better able to adapt to a low-calcium diet than are rats of the same age.
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    Calcified tissue international 15 (1974), S. 111-123 
    ISSN: 1432-0827
    Keywords: Fluoride ; Calcium ; Phosphorus ; Bone ; Periosteum
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    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Une méthode d'estimation de la surface périostée de l'os en voie de minéralisation est mise au point et appliquée à des porcs recevant 2 mg de fluorure par Kg de poids et par jour pendant 10 mois. L'adjonction de fluor intervient significativement dans le cas d'une déficience en calcium et phosphore. La surface en voie de minéralisation est nettement réduite. Lorsque le calcium et phosphore sont normaux, l'addition de fluorure augmente nettement la surface en voie de minéralisation. Le microscope électronique à balayage permet de mettre en évidence au niveau de l'os une perte de l'orientation longitudinale des fibers et des surfaces poreuses irrégulières chez les animaux soumis au floor.
    Abstract: Zusammenfassung Zur Bestimmung der verkalkenden Oberfläche des Periosts wurde eine Methode entwickelt und bei Schweinen angewandt, welche während etwa 10 Monaten 2 mg Fluorid per kg Körpergewicht und per Tag erhalten hatten. Dieses zusätzliche Fluorid hatte eine signifikante Wirkung bei Calcium- und Phosphormangel. Die verkalkende Oberfläuche ging stark zurück, während jedoch, wenn kein Calcium- und Phosphormangel bestand, das zusätzliche Fluorid die verkalkende Oberfläche vergrößerte. Beobachtungen mit dem Raster-Elektronenmikroskop am Knochen zeigten, daß die Längsorientierung der Fasern fehlte und daß Knochen von mit Fluorid gefütterten Tieren unregelmäßige, poröse Oberflächen aufwiesen.
    Notes: Abstract A method for estimating periosteal bone-mineralizing surface was developed and applied to swine fed 2 mg of fluoride/kg of body weight/day for about 10 months. Added fluoride interacted significantly with calcium and phosphorus deficiency. Mineralizing surface was greatly reduced, whereas when calcium and phosphorus were adequate, added fluoride greatly increased mineralizing surface. Scanning electron microscope observations of bone disclosed loss of longitudinal orientation of fibers and irregular porous surfaces in bone from fluoride-fed animals.
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    Calcified tissue international 15 (1974), S. 125-132 
    ISSN: 1432-0827
    Keywords: Bone ; Collagen ; Formic Acid ; Crosslinkages ; Cyanogen Bromide
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    Topics: Biology , Medicine , Physics
    Notes: Abstract Bovine and chicken bone collagens have been solubilized and presumably denatured (gelatin) by treatment of demineralized, powdered tissue with 70% formic acid. Short periods of extraction such as four hours at 30°, conditions commonly used during cyanogen bromide cleavage of collagen, solubilized 50% and 15% of the chicken and bovine bone collagens respectively. Treatment of the tissues with sodium borohydride partially inhibited the extraction of collagen from chicken bone, but had little effect on the extraction of calf bone collagen. The heterogeneity of the bone gelatin from both species on disc electrophoretic analysis suggested that peptide bonds had been cleaved in some of the collagen chains during exposure to formic acid, thus facilitating the solubilization of the bone collagen as the gelatin. Analysis of the collagen extracted from chicken bone for reducible crosslinks indicated that a large proportion of these bonds had remained intact, in contrast to a previous finding that most of these crosslinks were destroyed in bone gelatin extracted by 4 M CaCl2, at pH 7.0. The stability of the major reducible crosslinks in bone collagen to severe acid conditions may explain in part some of its unique properties, such as its failure to swell or be solubilized in dilute acid, which distinguish it from soft tissue collagens.
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    Calcified tissue international 15 (1974), S. 173-179 
    ISSN: 1432-0827
    Keywords: Bone ; Strength ; Tension ; Compression
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    Topics: Biology , Medicine , Physics
    Notes: Abstract A simple method is described for visualising regions of bone that have yielded in tension. The appearance of such regions is quite different from that of regions that have yielded in compression. The significance of these findings is discussed.
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    Calcified tissue international 15 (1974), S. 189-199 
    ISSN: 1432-0827
    Keywords: Bone ; Densitometry ; X-ray ; Radiation ; Specific gravity
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    Notes: Abstract X-ray and γ-radiation techniques for evaluating bone density under field conditions in cattle and sheep were investigated. The best results were obtained from measurements of the density of radiographs of tibial tarsal bones of sheep and from the absorption of γ-radiation of the tibial tarsal bones of sheep and the fibular tarsal bones of cattle. The γ-radiation techniques may be carried out rapidly under field conditions (up to 30 animals an hour) and bone density can be estimated with a standard error of 0.042–0.046 SG units.
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    Calcified tissue international 15 (1974), S. 181-188 
    ISSN: 1432-0827
    Keywords: Biopsy ; Bone ; Calcium ; Phosphorus ; Specific gravity
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    Topics: Biology , Medicine , Physics
    Notes: Abstract The specific gravities (SG) of bone samples taken from various parts of the skeleton of cattle and sheep were determined gravimetrically in an effort to establish which sites give the most reproducible and uniform results, so that between animals, or sequential within animals, comparisons may be made with maximum sensitivity. Samples obtained from the mandible of sheep and the rib of cattle and sheep were found to be too variable to be useful for most purposes. Best results were obtained using whole bones which are easily prepared, such as the tibial tarsal bones of cattle and sheep and the fibular tarsal bone of cattle. These bones gave within animal deviations of 0.012–0.024 SG units, when comparing left bone with right bone. Slightly higher values were obtained for coccygeal vertebrae from cattle and distal metacarpal condyles from sheep. SG was related to ash, calcium and phosphorus contents of coccygeal vertebrae of cattle and it is considered that, for survey work on the mineral status of the bones of cattle and sheep, the correlations are sufficiently high to make their determination unnecessary. This will enable radiation determined SG techniques to be applied to this type of work.
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    Calcified tissue international 16 (1974), S. 335-338 
    ISSN: 1432-0827
    Keywords: Fluoride ; Plasma ; Bone ; Age
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    Notes: Abstract Fluoride analyses were carried out on blood samples from fasting subjects and on iliac crest biopsies obtained at autopsy, using an ion-selective electrode. Correlation coefficients of 0.53 and 0.67 respectively were determined between plasma fluoride and age, and bone fluoride and age. The proportionate rates of increase of fluoride levels in plasma and bone with age and the similarity of the correlation coefficients suggest that the fasting plasma fluoride concentration is in equilibrium with bone fluoride.
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    Calcified tissue international 15 (1974), S. 201-212 
    ISSN: 1432-0827
    Keywords: Ultrastructure ; Alkaline Phosphatase ; Calcification
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    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Des cals expérimentaux de neuf jours, formés au niveau de radius de jeunes rats, sont traités par la méthode calcium-cobalt de Gomori (1939) pour la mise en évidence ultrastructurale de la phosphatase alcaline afin d'étudier son rôle éventuel dans le dépôt du calcium. L'activité enzymatique apparait initialement sous forme de précipités globulaires en dehors de la membrane cellulaire de jeunes chondroblastes hypertrophiques. Ce précipité donne ensuite naissance à des corps sphériques de phosphatase alcaline qui se forme près de la cellule. Ces corps sphériques s'observent dans une zone intermédiaire plus éloignée. Une formation de cristaux en aiguilles (apparemment une calcification) se développe dans des corps isolés ou agrégés, laissant voir nettement leurs limites, même lorsque la calcification est plus avancée au point qu'on ne peut plus distinguer des cristaux individuels. Au niveau des coupes témoins, traitées de façon identique mais sans substrat ou avec de l'E.D.T.A., on n'observe ni précipité enzymatique ou corps sphériques. L'aspect des dépôts cristallins dans des corps qui contiennent de la phosphatase alcaline ne peut s'expliquer que par l'existence d'une association étroite entre enzymes et calcification.
    Abstract: Zusammenfassung Neun Tage alter experimenteller Kallus an Radii von jungen Ratten wurde mit Gomori's (1939) Calcium-Kobalt Methode untersucht, um die Verteilung der alkalischen Phosphatase und ihre Beziehung zur Calciumablagerung ultrastrukturell zu demonstrieren. Enzymaktivität zeigte sich zuerst als globulares Präzipitat außerhalb der Zellmembran von Knorpelzellen im Beginn der Hypertrophie. Aus dieser Präzipitatschicht entstanden dann gerundete Körperchen, die sich von der Zelle abtrennten. Solche Körperchen wurden auch in größerer Entfernung von der Zelle beobachtet, d.h. in einer Zwischenzone zwischen benachbarten Zellen. Nadelförmige Kristalle, wahrscheinlich von Calcium-Salzen, wurden in einzelnen oder aggregierten Körperchen beobachtet. Die äußere Zone der Körperchen blieb jedoch deutlich sichtbar, selbst dann, wenn der Calciumgehalt derart zugenommen hatte, daß einzelne Kristalle nicht länger erkennbar waren. In Kontrollen, die in gleicher Weise behandelt waren, aber ohne Substrat oder mit Zufügung von EDTA, wurden weder Präzipitate noch Körperchen beobachtet. Das Auftreten von Calciumablagerungen in alkalischer Phosphatase enthaltenden Körperchen scheint kaum anders erklärbar als durch eine enge funktionelle Verbindung zwischen Enzym und Calciumablagerung.
    Notes: Abstract Nine day old experimental calluses in radii of young rats were treated with Gomori's (1939) calcium-cobalt method to demonstrate ultrastructurally the presence of alkaline phosphatase in a search for its possible role in the desposition of calcium. Enzyme activity first appeared as globule-like precipitates outside the cell membrane of early hypertrophic cartilage cells. This precipitate layer then seemed to give rise to spherical bodies of alkaline phosphatase which occur at a slight distance from the cell. The spherical bodies were also observed further away from the cell in an intermediate zone between neighboring cells. Needle-like crystal formation, apparently calcification, occurred inside single or aggregated bodies, leaving their peripheral rim clearly visible, even when calcification had increased to such an extent that individual crystals could no longer be recognised. In controls, treated in the same way but without substrate, or with EDTA, no enzyme precipitate or spherical bodies were seen. The appearance of crystalline deposits in bodies which contain alkaline phosphatase seems difficult to explain on any other basis than that there is a close functional association between the enzyme and calcification.
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    Calcified tissue international 16 (1974), S. 305-313 
    ISSN: 1432-0827
    Keywords: Osteosarcoma ; Lyophilization ; Induction ; Bone
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    Topics: Biology , Medicine , Physics
    Notes: Abstract Bone formation was induced by iso- and home-implantation of lyophilized mouse osteosarcoma, in which an osteogenic activity is observed. The inducing factor is present exclusively in osteosarcoma, such as BF and Gardner, while not in non-osteogenic tumors, such as Ehrlich ascites tumor (2N & 4N) or mouse mammary carcinoma. The production of bone was rapid and extensive. It usually occurred within 21 days, and the time required for osteogenesis was almost the same as that reported in previous studies.
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    Archives of microbiology 96 (1974), S. 145-153 
    ISSN: 1432-072X
    Keywords: Ultrastructure ; Scenedesmus Bristles ; Openings ; Props ; Ridges ; Tubules ; Brisble Origin
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    Topics: Biology
    Notes: Abstract Bristles radiating from openings were detected on colonies and unicells ofScenedesmus culture N 46, when examined with transmission and scanning electron microscopes. Although narrower, they correspond in gross appearance and ultrastructure to previously describedScenedesmus bristles. Openings, bordered by a series of props, are unlike those ofScenedesmus culture 614. Additional props are observed scattered independently on the cell wall; ridges are composed of a linear row of props. Sections of cells, or cell walls, reveal an additional prop, situated inside the openings; these props are composed of several tubules. Possible extrusion of bristles through these tubules, as well as the origin of the bristle from the cavity and vesicles immediately under the opening are discussed.
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    Archives of microbiology 96 (1974), S. 305-317 
    ISSN: 1432-072X
    Keywords: Marine Fungi ; Ultrastructure ; Multilamellate Sporangial Wall ; Sagenogenetosome ; Zoospore Cleavage
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    Topics: Biology
    Notes: Abstract The morphology and ultrastructure of aJaponochytrium sp. has been studied by light, scanning and transmission electron microscopy. The wall has been shown to be multilamellate and persistent. Stages in zoospore cleavage are described and sagenogenetosomes reported in mature sporangia.
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    Archives of microbiology 98 (1974), S. 147-158 
    ISSN: 1432-072X
    Keywords: Allomyces ; Zoospores ; Cell Wall ; Wall Formation ; Lomasome ; Ultrastructure
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    Notes: Abstract Ultrastructural observations on encysting haploid zoospores of Allomyces arbuscula are presented with special reference to cell wall deposition. Multivesicular bodies are observed in the cytoplasm of zoospores 15 min after inoculation, lomasomes after 30 min and fine membrane profiles between the plasmalemma and the cyst wall are observed after 4 h indicating a possible system for secretion of cell wall components.
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    Archives of microbiology 99 (1974), S. 331-344 
    ISSN: 1432-072X
    Keywords: Myxomycetes ; Ultrastructure ; Development ; Systematics ; Food Vacuoles ; Stalk Development
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    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 96 (1974), S. 175-182 
    ISSN: 1432-072X
    Keywords: Ultrastructure ; Septa ; Schizophyllum ; Dissolution
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    Topics: Biology
    Notes: Abstract A strain ofSchizophyllum commune carrying a mutation in theB-mating factor (B-mut) shows septal dissolution when grown at 30° C for 2 to 3 days. The septa are intact if the organism is grown at 25° C for the same time, but begin to break down within 1 h after transfer to 30° C. At the ultrastructural level the dolipore swelling is the first part of the septal apparatus to be degraded, closely followed by the disorganization of the parenthesomes. A progressive thinning of the septal cross-wall produces an enlargement of the septal aperture sufficient to allow the passage of nuclei. It appears that degradative enzymes are probably carried to the site of septal dissolution in vesicles derived from endoplasmic reticulum in the area of the septal apparatus.
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    Archives of microbiology 96 (1974), S. 271-279 
    ISSN: 1432-072X
    Keywords: Anabaena cylindrica ; Nitrogen Starvation ; Pigmentation ; Ultrastructure ; Heterocyst Differentiation ; Nitrogenase Activity
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    Topics: Biology
    Notes: Abstract Nitrogen starvation, effected by incubating a culture ofAnabaena cylindrica in a medium free from combined nitrogen and under an atmosphere of 1% CO2 in argon, leads to rapid and characteristic changes in the appearance, structure and function of the alga. Change of colour, due apparently to a decrease in the amounts of nitrogenous pigments, is accompanied by a structural transformation of vegetative cells: cyanophycin granules and polyhedral bodies disintegrate, lipid and glycogen accumulate, and large membrane-bound spaces form by means of thylakoid swelling and vesiculation. The rate of heterocyst differentiation and nitrogenase activity is increased. These changes are fully reversed on addition of ammonia to the culture. It appears that thylakoids reform by coalescence of small vesicles assembled in the intrathylakoidal space. Rapid ammonia assimilation is indicated by ample formation of cyanophycin granules in vegetative cells and of “plugs” in the heterocysts.
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    Archives of microbiology 98 (1974), S. 199-206 
    ISSN: 1432-072X
    Keywords: Ultrastructure ; Chlamydomonas ; Senescent ; Microtubules ; Complexes
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    Notes: Abstract Complexes of twisted ribbons composed of ordered arrays of microtubules are identified in close association with the plasmalemma and the surfaces of some organelles in senescent cells of photoheterotrophically cultured Chlamydomonas dysosmos. The ribbon complexes occur throughout the cytoplasm, and do not appear related to the flagellar insertions. The component microtubules are approximately 26 nm in width, exhibiting a center-to-center spacing of about 44 nm. Additional cytoplasmic microtubules are often closely related to the tubular complexes. A detailed description of their fine structure is presented here which tends to support the ascribed function of microtubules in maintaining the structural integrity of the protoplasm.
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    Archives of microbiology 99 (1974), S. 221-230 
    ISSN: 1432-072X
    Keywords: Anabaena cylindrica ; Molybdenum ; Vanadium ; Nitrogenase ; Ultrastructure ; Storage Products ; Heterocyst Frequency
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    Notes: Abstract The structural and functional symptoms of molybdenum deficiency inAnabaena cylindrica grown in a medium without combined nitrogen and thus dependent on fixation of elemental nitrogen, resemble those brought about by nitrogen starvation. However, the substantially increased rate of heterocyst differentiation in this culture is not accompanied by a corresponding increase in nitrogenase activity; on the contrary, enzyme activity is severely impaired in the absence of molybdenum. When the supply of molybdenum, or of ammonia, is restored, the alga recovers rapidly. Vanadium exerts an inhibitory effect upon nitrogen-fixing ability of the alga, and its presence in the molybdenum-deficient culture results in the amplification of the symptoms of mlybdenum deficiency.
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    Archives of microbiology 99 (1974), S. 265-269 
    ISSN: 1432-072X
    Keywords: Ultrastructure ; Microbodies ; Vacuolaria ; Gonyostomum ; Chloromonadophyceae ; Chromophyta
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    Notes: Abstract Microbody-like organelles occur in the cytoplasm of two chloromonadophycean algae,Vacuolaria virescens Cienkowsky andGonyostomum semen Diesing. Microbodies ofVacuolaria andGonyostomum have a granular matrix which lacks a crystalloid core; they are often present in close association with elements of the endoplasmic reticulum. The occurrence of microbodies in other algae is briefly reviewed.
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  • 46
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    Archives of microbiology 101 (1974), S. 95-107 
    ISSN: 1432-072X
    Keywords: Zoophagus insidians Rotifer ; Predacious Fungi ; Oomycetes ; Glue Secretion ; Ultrastructure
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    Notes: Abstract The predacious watermold Zoophagus insidians traps loricate rotifers on short, lateral branches of the main, hyphal axis. These branches or “traps” are packed at their distal ends with a number of vesicles filled with an electron-dense matrix. Electron micrographs of the mycelium disclose a two-layered wall; the outer layer is electron dense and the inner, electron transparent. The outer dense layer on the tip of the “trap” is organized into a number of fine ridges and occasional discontinuities. Thin sections through recently trapped rotifers indicate that the cilia of the animals are stuck to the trap by a glue. This adhesive is derived from secretion of the matrix of the vesicles aggregated in the tip of the trap. The secretion mechanism is triggered by the animal and is accompanied by: 1. The separation of the two layers of the wall, 2. fusion of the vesicles with the cell membrane and 3. extrusion of the glue through pits in the tip of the inner wall of the “trap”. After snaring a rotifer, the previously arrested branch grows as a haustorium into the body cavity of the animal. The host tissues disintegrate within a few hours and appear to be the main nutrient source of the fungus.
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  • 47
    ISSN: 1432-072X
    Keywords: Bdellovibrio bacteriovorus ; Spirillum serpens ; Freeze Fracture ; Electron Microscopy ; Ultrastructure ; Membrane Damage ; Organismic Associations
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    Notes: Abstract The freeze-fracture technique and electron microscopy have been used to demonstrate that localized damage is inflicted upon the cytoplasmic membrane of Spirillum serpens VHL within 20 to 30 min after the start of its association with Bdellovibrio bacteriovorus 109D. This damage is not observed in uninfected Spirillum cells, nor in infected cells within the first 10 min. This damage takes the form of a “blister” which, when viewed stereoscopically in electron micrographs, is seen to project toward the interior of the Spirillum cell. Shortly after its formation, the blister becomes elaborated into a series of ridges which may assume forms ranging from an elaborate spiral to a series of loops or knots. The formation of a blister is shown to involve both the inner and outer leaves of the membrane bilayer, and evidence is presented to indicate that the blister site corresponds to the site of attachment of the Bdellovibrio cell. The hypothesis is proposed that this ultrastructural damage is the cytological basis for the controlled and localized leakage through the cytoplasmic membrane into the periplasmic space of the Spirillum cell at locations adjacent to the Bdellovibrio cell. It is suggested that this localized membrane damage may be the ultrastructural basis for the high efficiency with which bdellowvibrios are known to incorporate cytoplasmic materials from the other bacteria in whose periplasmic spaces they develop.
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  • 48
    ISSN: 1432-072X
    Keywords: Streptomycetes ; Ultrastructure ; Surface Sheath
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    Notes: Abstract 1. Tubular-like structures were regularly revealed in the surface sheath of the aerial mycelium of the parent strain of Streptomycetes roseoflavus var. roseofungini. In their shape and dimensions these structures were highly reminiscent of those massive accumulation of which was earlier reported to occur in cultures of dedifferentiated nocardioform “fructose” mutant of the same parent strain. 2. The tubular-like structures of the aerial mycelium sheath were shown to be markedly susceptible to brief acetone washing, undergoing almost complete desintegration. 3. On addition of water to crude acetone extract of the aerial mycelium precipitation and possible selfassembly of a spectrum of various structures occurred (folded scaly, bubble-like, spout-like). Some among structures so produced were reminiscent of those found in spectra of structures observed in reconstruction experiments with tubules from the mutant as well as of structures found in the aerial sheath of the parent strain and some other actinomycetes. Similarity in subunit structure of above materials was also noticeable. The presence, in the sheath of aerial mycelium, of material with a tendency to selforganization is discussed in relation to the possible involvement of selfassembly processes in the formation of the surface sheath.
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    Archives of microbiology 100 (1974), S. 419-436 
    ISSN: 1432-072X
    Keywords: Gloeobacter violaceus ; Photosynthetic Pigments ; DNA Base Composition ; Fatty Acid Composition ; Cyanobacterium ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Gloebacter violaceus gen. and sp. n. is a unicellular photosynthetic prokaryote of unusual cellular structure. The only unit membrane in the small, rod-shaped cells is the cytoplasmic membrane, which has a simple contour, without intrusions. Immediately underlying it is an electron-dense layer 80 nm thick. Gloeobacter is an aerobic photoautotroph which contains chlorophyll α, β-carotene and other carotenoids, allophycocyanin, phycocyanin and phycoerythrin. Chlorophyll and carotenoids are associated with the particulate fraction of cell-free extracts, and are thus probably localized in the cytoplasmic membrane. The phycobiliproteins may be associated with the electron-dense 80 nm layer. The DNA contains 64.4 moles percent GC. The cellular lipids have a high content of polyunsaturated fatty acids, largely linoleate and γ-linolenate. Despite its atypical fine structure, Gloeobacter is evidently a cyanobacterium, sufficiently different from other unicellular cyanobacteria to be placed in a new genus.
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  • 50
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    Cell & tissue research 147 (1974), S. 433-440 
    ISSN: 1432-0878
    Keywords: Mushroom-shaped gland ; Periplaneta ; Utriculi majores ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The utriculi majores, the largest tubules of the mushroom-shaped sex gland complex of P. americana are lined by a single layer of secretory cells with basal plasmalemmal infoldings and apical microvilli, and enveloped by a thin layer of slow-acting muscle. The latter is predominantly monomyofibrillar, with an ill-developed T-system, sarcoplasmic reticulum and striations. The secretory epithelium consists of typical protein-synthesizing and-exporting cells with an extensive rough endoplasmic reticulum and active Golgi elements. Secretory granules, budded off from layered cisternae of the Golgi complex, are more numerous in the vicinity of the luminal surface. The luminal contents are rich in proteins, neutral lipids and phospholipids; there are also some sulphated and nonsulphated acid mucopolysaccharides.
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    Cell & tissue research 148 (1974), S. 11-26 
    ISSN: 1432-0878
    Keywords: Dentine ; Bone ; Collagen structure ; Collagen mineralization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary It has been previously shown that the distances between the nuclei within the collagen bundles of mineralizing tissues were in good agreement with the repeat distances of the cross-banding pattern of collagen, which supports the assumption that the distances between the mineral deposits reflect to a good approximation the distances between nucleation centres on the collagen macromolecule. However, the lateral separation of the nuclei were significantly higher than the distances between close-packed triple helices. Recently a new model of collagen aggregation has been proposed in which the smallest morphological units are subfibrils (Ø approx. 39 Å) packed in tetragonal array. This led us to measure once again the lateral separation between a) close-packed calcium phosphate needles lying in bundles at (1) the mineralizing front of mantle dentine and (2) at the mineralizing front of rat tail bone, and b) between the uranyl-lead nuclei produced in the staining of rat tail tendon. The mean lateral distances separating these nuclei fell within the range of 39–47 Å, which is a little higher than the distances of 39 Å which separate the microholes between the subfibrils in the tetragonal packing model, which are regarded as the likely sites of nucleation. If, however, it is assumed that the forces generated during mineralization can cause the collagen fibres to swell, then the lateral separation of the nuclei and the distances between the microholes would correspond very closely.
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  • 52
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    Cell & tissue research 148 (1974), S. 69-82 
    ISSN: 1432-0878
    Keywords: Ultimobranchial glands ; Anuran larvae ; Metamorphosis ; Ultrastructure ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of ultimobranchial (UB) gland cells from Rana temporaria larvae 48 h after hatching until the completion of metamorphosis is described. A single UB cell type is present, believed to be the characteristic C cell, in which secretory granules are first detectable in 8 day post-hatching larvae. These secretory granules show an intimate association with lipid droplets. Unusual membranous and crystalloid inclusions, which may represent yolk platelets, are found in UB glands of very small larvae. The significance of a range of UB organelles is discussed and some scanning electron micrographs presented. This report is believed to be the first published ultrastructural and scanning electron microscope study of larval anuran UB glands.
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  • 53
    ISSN: 1432-0878
    Keywords: Ovary ; Blue fox ; Lutein cells ; Plasma progesterone ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary An electron microscopic investigation of the lutein cells of the blue fox was undertaken, based on the hypothesis that differences in plasma progesterone levels at differing stages of pregnancy might be reflected in the ultrastructural organization. Comparisons were made between corpora lutea taken from animals mated 1, 2, 5, 14, 18, 20, 28, 33, 36, 39 and 45 days after the estimated time of ovulation. Measurements of progesterone on plasma samples were performed by a rapid competitive protein-binding assay. During the period with increasing and/or high plasma progesterone levels, (i.e. 1 to 14 days after ovulation) the lutein cells are characterized by evenly distributed cisternal agranular ER, mitochondria with both tubular and lamellar cristae, and electron-dense lipid droplets. The abundant agranular ER is closely associated with the lipid droplets and mitochondria. During the period with declining plasma progesterone levels, the lutein cells present a different morphological picture: the agranular ER assumes the form of bundles of parallel tubules disposed in several planes. During the latest stages observed, these “bundles” are disrupted and most of the agranular ER become arranged in smaller concentric whorls. Both kinds of whorls regularly enclose lipid droplets, dense bodies and mitochondria. The regions between the whorls contain scattered cisternae of endoplasmic reticulum, ribosomes, mitochondria and lysosome-like dense bodies.
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  • 54
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    Cell & tissue research 150 (1974), S. 463-479 
    ISSN: 1432-0878
    Keywords: Ovarian follicle ; Vitellogenesis ; Cephalopods ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die Feinstruktur des Ovarfollikels von Alloteuthis subulata Lam. während der euplasmatischen Wachstumsphase und der Vitellogenese wurde licht- und elektronenmikroskopisch untersucht. Die Oogenese kann in drei Stadien unterteilt werden. Oocyten des Stadiums I haben noch kein Follikelepithel. Während des Stadiums II faltet sich das Follikelepithel in die Oocyte ein, die ihre euplasmatische Wachstumsphase durchläuft. Die Follikelzellen zeigen typische Merkmale von Zellen mit starker Proteinsynthese. Im Stadium III wird das Chorion von den Follikelzellen gebildet. Im Gegensatz zu älteren lichtmikroskopischen Beobachtungen ergeben sich keine Hinweise, die für eine Beteiligung der Follikelzellen an der Bildung exogenen Proteindotters sprechen. Die eigenen Beobachtungen sprechen vielmehr für eine weitgehend autonome Synthese des PAS-positiven Dotters durch die Oocyte unter Beteiligung des stark ausgebildeten Golgi-Apparates. Die Befunde werden im Vergleich mit Beobachtungen zur Vitellogenese anderer Invertebraten und Vertebraten diskutiert.
    Notes: Summary The structure of the ovarian follicle of Alloteuthis subulata Lam. during the euplasmic growth phase and vitellogenesis has been investigated by light and electron microscopy. Oogenesis can be divided into three stages. Oocytes of stage I are not yet surrounded by a follicle cell epithelium. During stage II, infolding of the follicular epithelium into the oocyte and the euplasmic growth phase of the oocyte take place. Follicle cells show all attributes typical for protein synthesizing cells. During stage III, formation of the chorion occurs due to follicle cell activity. In contrast to earlier light microscopical observations, there are no indications of an engagement of the follicle cells in the production of exogenous yolk protein, which could be taken up by the oocyte in pinocytotic vesicles. The observations rather favour the idea of a largely autonomous synthesis of the PAS-positive yolk in the oocyte. The Golgi apparatus seems to be engaged in yolk production. The findings are discussed in comparison with observations on vitellogenesis in other invertebrates and vertebrates.
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    Cell & tissue research 151 (1974), S. 69-77 
    ISSN: 1432-0878
    Keywords: Prostate (rabbit) ; Anterior lobe ; Apocrine secretion ; Ultrastructure ; Protein secretion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The structure of glandular cells in the anterior lobe of the rabbit prostate was reinvestigated, especially after fixation by vascular perfusion with glutaraldehyde. The lumina of the gland contain abundant globules of an amorphous material surrounded by a membrane. A few dense bodies and scattered globules with internal vesicles also occur. These luminar contents obviously correspond to the particles observed in the semen of rabbits. Strong evidence was found for the formation of the globules by an apocrine secretory process. Material similar to the contents of the luminar globules accumulates in the cell apex together with vesicles, probably of Golgi origin, but without any other organelles. Protrusions from the cell surface contain similar material, but the vesicles generally disappear before the forming globule is finally pinched off from the cell surface. The characteristic feature of the secretory cell are the paucity of endoplasmic reticulum and the large amounts of ribosomes. This is interpreted as a specialization of the cell for the production of secretory protein that is not segregated within membranes until it is discharged from the cell by apocrine secretion.
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    Cell & tissue research 151 (1974), S. 79-92 
    ISSN: 1432-0878
    Keywords: Adenohypophysis ; PMS-primed rat ; FSH gonadotrope ; LH gonadotrope ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The existence of distinct FSH and LH gonadotropes has been suggested by several investigators whereas others have supported a one-gonadotrope hypothesis. To obtain further clarification on this subject, ultrastructural studies of pituitaries and radioimmunoassays of serum FSH, LH and prolactin were carried out in the PMS treated immature rat. The surge of FSH began at 12 noon on day 32 with a maximum at 6 pm that continued into the next day, while the LH maximum was reached at 4 pm. The serum levels of prolactin also began to rise at 12 noon on day 32 but did not reach maximum until 8 am of day 33. FSH cells as defined earlier by Costoff (1973) were well granulated at 12 noon and at 4 pm on day 32. At this later time many FSH cells exhibited extensive Golgi complexes, hypertrophied vacuolar endoplasmic reticulum and often times greatly swollen mitochondria. At 7 PM of day 32 many FSH cells were in various stages of degranulation. LH cells were enlarged and well granulated prior to 12 noon of day 32 but thereafter appeared degranulated. On day 31, prolactin cells were enlarged and well granulated. Although these cells contained extensive endoplasmic reticulum and Golgi complexes, there were few mature granules during day 32 and in the early morning hours of day 33. At 1 PM of day 33 most of the FSH and LH, and some prolactin cells were again granulated. These studies correlating ultrastructure with FSH and LH levels in the serum of PMS treated rats further suggest the existence of two distinct gonadotropes in the rat, one producing FSH and another LH.
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  • 57
    ISSN: 1432-0878
    Keywords: Paraventricular organ ; Xenopus laevis ; Monoamines ; Cytochemistry ; Ultrastructure
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    Notes: Summary Ultracytochemical identification of monoamines in the paraventricular organ (PVO) of Xenopus laevis tadpoles was achieved by applying glutaraldehyde-potassium dichromate fixation to the brains. It appears that the amines are concentrated inside elongated or round large granular vesicles within the neurons. The presence of dopamine and, to a lesser extent, of indolamines in neurons of the PVO is discussed.
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    Cell & tissue research 152 (1974), S. 493-512 
    ISSN: 1432-0878
    Keywords: Median eminence ; 6-Hydroxydopamine ; Fluorescence ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The extent of degeneration and regeneration of catecholamine-containing nerve fibres in the external layer of the median eminence of the rat has been assessed following treatment with 6-OHDA. Ultrastructural and fluorescence histochemical evidence suggests that nerve terminal degeneration occurs in the external layer of the caudal regions of the median eminence, including the anatomical stem, following intravenous injection of 6-OHDA in a dose of 100 mg/kg. No degeneration in the external layer of the median eminence was observed when the drug was given as sequential intracisternal injections to adult rats or neonatal rats by subcutaneous injections. The fluorescence histochemical studies suggest that regeneration of catecholamine-containing neurons is substantially complete within three weeks of treatment with intravenous 6-OHDA.
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    Cell & tissue research 153 (1974), S. 277-292 
    ISSN: 1432-0878
    Keywords: Ultrastructure ; Pineal Gland ; Mole ; Paracrystalline structures
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé Les pinéalocytes (au sens strict: Wolfe, 1965) de l'épiphyse de la Taupe (animal vivant pratiquement toujours dans une complète obscurité) examinés au microscope électronique, ont été comparés à ceux d'autres Mammifères. Dans le périkaryon des mitochondries, des ribosomes, du réticulum endoplasmique lisse et granulaire et quelques lysosomes et inclusions lipidiques sont présents. La présence à l'intérieur de certaines cavités du réticulum endoplasmique granulaire et parfois entre les deux feuillets de l'enveloppe nucléaire, de structures paracristallines (de nature protéique ?) est caractéristique des pinéalocytes de cet animal. L'appareil de Golgi sécréte des vésicules claires de 500 à 1500 Å de diamètre. Quelques très rares grains de sécrétion, dont l'origine golgienne n'a pas encore été démontré, ont été observé dans le périkaryon et à l'extrémité de certains prolongements. Un grand nombre de structures ciliaires (9+0 paires de tubules) ont également été observés dans les pinéalocytes.
    Notes: Summary The ultrastructure of the mole pinealocytes, a mammal which lives practically in complete darkness, has been examined and compared with that of other mammals. Mitochondria, ribosomes, smooth and granular endoplasmic reticulum, lysosomes and lipid incluclusions are present in the perikaryon. The presence of a paracrystalline structure of a possibly proteinaceous nature in some cisterns of the granular endoplasmic reticulum and between the two layers of the nuclear membrane, is characteristic of the mole pinealocyte. The Golgi complex produces clear vesicles of 500–1500 Å in diameter. Occasionally, some dense core secretory vesicles were observed in the perikaryon and in the ending of cell processes. Their presumed origin from the Golgi complex could not yet be demonstrated. A large number of ciliary derivatives (9+0 pattern) are also present in the mole pinealocyte.
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    Cell & tissue research 153 (1974), S. 339-355 
    ISSN: 1432-0878
    Keywords: Sertoli cell, human ; Morphological classification ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary As revealed by light microscopical investigations the human Sertoli cell presents different appearances according to the pattern of infranuclear cytoplasmic inclusions. Although two or three stages of spermatogenesis are seen in a single cross section of a seminiferous tubule the Sertoli cells all show virtually the same features in such a cross sectioned tubule. The different appearances are also evident under the electron microscope. Although no obvious correlation was found with the stages of spermatogenesis in the seminiferous epithelium, the Sertoli cell appearances described here may be assumed to represent different metabolic situations. Other features of Sertoli cell ultrastructure are discussed such as the presence of residual bodies in the apical cytoplasm, glycogen-rich areas protruding towards the tubular lumen or the extracellular space, and membrane bound, round structures, found between the membranes of the smooth endoplasmic reticulum and resembling the “microbodies” of steroid producing cells.
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    Cell & tissue research 153 (1974), S. 415-417 
    ISSN: 1432-0878
    Keywords: Spleen (human) ; Periarteriolar lymphocytic sheath ; Reticular cell ; Enzyme histochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Interdigitating cells are demonstrated as a special type of fixed cell in the periarteriolar lymphocytic sheaths of the human spleen. These cells show typical ultrastructural features as well as a characteristic enzyme histochemical pattern that distinguish them from other reticular cells in the splenic white pulp.
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    Cell & tissue research 154 (1974), S. 181-188 
    ISSN: 1432-0878
    Keywords: Striated muscle ; Iris ; Guinea pig ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Transverse sections of the sphincter pupillae of the guinea-pig iris show, among about 3000 smooth muscle cells, one or two cells with several features of striated muscle fibres. The myofilaments of these special, “striated” muscle cells have irregular and variable arrangements, but they are readily distinguishable from those of smooth muscle cells. The sarcoplasmic reticulum is conspicuous and is characterized by an electron dense content. “Striated” muscle cells show no nexuses.
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    Cell & tissue research 154 (1974), S. 231-249 
    ISSN: 1432-0878
    Keywords: Pituitary ; Goldfish ; Innervation ; Ultrastructure
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    Notes: Summary The innervation of the pituitary gland of Carassius auratus was studied by light and electron microscopy under various physiological and experimental conditions to investigate whether or not neurosecretory fibres play a role in regulating pars distalis function. Two types of neurosecretory fibre (Type A and Type B) were distinguished. Prolactin, ACTH and TSH1 cells were innervated by Type B fibre terminals separated from the endocrine cells by a continuous basal lamina (“indirect contacts”). Gonadotropic, STH and TSH2 cells were innervated by Type A as well as Type B neurosecretory fibres, mostly without an intervening basal lamina (“direct contacts”). The assessment of the amount of neurosecretory granules and microvesicles in nerve terminals during the pre-spawning, spawning and postspawning seasons and following the administration of Oestradiol, Thyroxine, Thiourea and Metopiron respectively revealed convincing evidence for a participation in pars distalis control for Type A and Type B fibres innervating gonadotropic cells and STH cells and Type B fibres innervating TSH2 and ACTH cells. Immediately after spawning both nerve fibre types innervating gonadotropic cells and Type A fibres innervating STH cells showed a striking decrease in the amount of dense core vesicles. During the spawning season nerve fibres innervating somatotropic cells, TSH2 cells and ACTH cells also undergo changes suggesting that prior to spawning major changes in the endocrine system of the goldfish take place.—These results point to a dual control, by peptides and amines, of teleost pars distalis function.
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  • 64
    ISSN: 1432-0878
    Keywords: Thyroid gland ; Gymnophiona (Amphibia) ; Metamorphosis ; Ultrastructure ; Radioiodide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Different developmental stages of two species of the genus Ichthyophis have been investigated. In the late embryo the follicular cells of the thyroid gland exhibit various degrees of cytodifferentiation. Well differentiated cells show a polar organization and contain numerous granular inclusions, but a colloid-containing lumen is rare. Most cells at this stage contain large lipid inclusions. In young and older larvae the cells contain well-developed rough ER and Golgi systems, numerous mitochondria, and abundant granular and vesicular inclusions. Tentative identifications were made of primary lysosomes, secondary lysosomes, residual bodies, and two types of small apical vesicles—containing resorbed colloid or transporting material into the follicular lumen. In the larvae the number of apical microvilli is relatively high. The thyroid cells of the older larvae seem to contain more granular and vesicular inclusions than those of the younger larvae. In the adult the size of the follicles greatly increases, the height of the epithelium decreases, microvilli become rare, residual bodies are more frequent, and the small primary lysosomes are replaced by larger ones. Colloid droplets have been found only rarely in the cytoplasm of the thyroid cells of adult animals. In the immediate neighbourhood of the follicular epithelium, profiles of nerve fibres were found in all animals. Radioiodide investigations—measurements of conversion ratio and thyroid uptake factor—show, if compared with the results of corresponding studies in other amphibians, only relatively small differences between the larvae on the one hand and larvae and adults on the other. The absolute counts of the thyroid region are lowest in the adult and highest in the older larvae, shortly before metamorphosis. Furthermore our results indicate, on the basis of four animals tested, that in Ichthyophis the activity of the thyroid gland is temperature dependent. The results in Ichthyophis show that the classical stages of metamorphosis, in other amphibians characterized among other things by different levels of thyroid activity, are very indistinct in this animal.
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    Cell & tissue research 155 (1974), S. 337-351 
    ISSN: 1432-0878
    Keywords: Primitive nervous systems ; Nerve plexus ; Flatworm ; Platyhelminthes ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The peripheral nervous system of the polyclad flatworm Notoplana acticola is described from electron microscopic observations. There are two components, a subepithelial system and a submuscular plexus. The subepithelial system lies among muscle cells beneath the basement membrane of the epithelium. Axons and processes containing clear or dense-cored vesicles were found. The subepithelial system is in the form of a feltwork of fibers rather than a nerve-net. The submuscular plexus has both specialized and primitive aspects to its organization. In the former category are sheathed axons and complex synaptic configurations while the latter can be seen in the numerous naked axons, somata lying deep in the nerve tissue and islands of neuropil scattered along the nerve tracts.
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    Cell & tissue research 150 (1974), S. 271-279 
    ISSN: 1432-0878
    Keywords: Heavy bodies ; Oogenesis ; Maturation ; Sea urchin ; Ultrastructure
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    Topics: Biology , Medicine
    Notes: Summary An ultrastructural study of in vitro maturation of A. punctulata oocytes was undertaken to determine when heavy body formation was initiated. No heavy bodies were seen in germinal vesicle oocytes or in oocytes undergoing germinal vesicle breakdown or polar body formation. Heavy bodies were only observed in ova examined one to two hours after pronuclear formation. Several small heavy bodies were seen in sections of eggs fixed as early as three hours after the pronucleus had formed. The number of these structures in the egg cytoplasm increased with time. Therefore it is concluded that heavy body formation in sea urchin ova is a phenomenon following nuclear maturation.
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  • 67
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    Keywords: Avian salt gland ; Electrolyte transport ; Ultrastructure ; Ruthenium red ; Dialyzed iron ; Sialic acid
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    Notes: Summary Both ruthenium red and dialyzed iron techniques indicated that anionic protein-carbohydrates were associated with the plasmalemma of secretory cells in mallard salt glands. Digestion of the tissue with neuraminidase prior to dialyzed iron staining provided evidence that much of the anionic nature of this surface was due to sialic acid. These results were confirmed by biochemical assays showing that the salt-gland tissue contained a relatively high sialic-acid content and that the amount of sialic acid increased with salt-water adaptation. Possible roles of these anionic sites are discussed in relation to currently accepted hypotheses of electrolyte transport.
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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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    Cell & tissue research 152 (1974), S. 113-128 
    ISSN: 1432-0878
    Keywords: Rabbit pars intermedia ; Ultrastructure ; Nerve terminal ; PI-type glandular cell ; ACT-type cell
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary By electron microscopy three types of nerve terminals have been identified in adult rabbit pars intermedia (PI). The characteristics of these are described and their development traced. The distribution of nerve terminals and neurons within the PI is documented. In particular the association between types of nerve terminal and the different glandular cells is shown to be precise and selective. Direct innervation of the ACT-type cells in the rabbit PI is described for the first time. The author is particularly grateful to Dr. J. W. B. Bradfield for help in the preparation of this paper.
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    Cell & tissue research 152 (1974), S. 229-238 
    ISSN: 1432-0878
    Keywords: Pituitary gland (rat) ; Estrogen administration ; Somatotroph and mammotroph ; Ultrastructure ; Radioautography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the normal male rat pituitary tritiated thymidine labeled mainly STH cells (somatotrophs), no labeled prolactin cell was found. Following estradiol treatment for 21 days tritiated thymidine labeled mainly prolactin cells (mammotrophs). To determine the origin of these mammotrophs tritiated thymidine was given before the estradiol treatment started, thus labeling many somatotrophs. After 21 days of estradiol, out of 42 labeled cells, 14 were mammotrophs and 13 were somatotrophs; these results suggest that there might be a true transformation of somatotrophs into mammotrophs under the influence of estradiol or that there exist two types of somatotrophs: 1) a committed somatotroph which is not transformed by estrogen treatment, and 2) an uncommitted mammosomatotroph, which under normal conditions bears the features of a somatotroph, but which transforms into a mammotroph under the influence of estradiol.
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    Cell & tissue research 152 (1974), S. 253-258 
    ISSN: 1432-0878
    Keywords: Olfactory organs ; Cephalopods ; Chemoreception ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of the so-called olfactory organ of Octopus vulgaris has been investigated. Electron microscopy shows the superficial layer of the epithelium to consist mainly of cells bearing microvilli. Below this, often very deeply, lie very many large cells, which bear numerous cilia. These cells open to the surface via narrow processes running between the epithelial cells. Although details of their innervation have yet to be established the large cells are assumed to be receptors and these findings are interpreted as evidence that this organ is indeed chemosensory.
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    Cell & tissue research 152 (1974), S. 239-252 
    ISSN: 1432-0878
    Keywords: Ultrastructure ; Xenopus laevis ; Histochemistry ; Subcommissural organ (SCO)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ultrastructural features of the subcommissural organ (SCO) cells in larvae (stages 56–58, according to Nieuwkoop and Faber, 1956), toadlets (3 months after metamorphosis) and older toads (2-year old) of Xenopus laevis are described. Several age-related morphological differences in the endoplasmic reticulum (ER) of the SCO cells have been found. In old toads the rough ER assumes a special “ladder-like” membrane configuration in its cisternal lumen. By means of the periodic acid-chromic acid-silver methenamine (PA-CrA-SM) method, complex carbohydrates are detected electron microscopically in the SCO cells. Positive reactions take place in the cell adhesive apparatus, the secretory granules, part of the Golgi complex, and the intracisternal “ladder-like” structure. Passing through the Golgi complex, the secretory products mature into the secretory granules by association of their proteinaceous component with polysaccharides. The majority of the secretory granules are released from the apical cell surface by means of reverse pinocytosis, while the rest are released through the basal process into the blood circulation.
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  • 73
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    Cell & tissue research 152 (1974), S. 385-401 
    ISSN: 1432-0878
    Keywords: Nephridium ; Hirudo medicinalis ; Central canal ; Urinary bladder ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Bei elektronenmikroskopischer Untersuchung des nephridialen Zentralkanals von Hirudo medicinalis L. können mehrere Kanalabschnitte unterschieden werden, die zum Teil frei im Bindegewebe liegen, wie der Anfangs-, der intermediäre und der Endkanal, oder aber durch mehr oder weniger enge Verzahnung mit Canaliculuszellen verbunden sind (innerer und weiter Kanal). Strukturen, die mit transzellulärem Ionentransport in Beziehung gebracht werden können — ikrovilli und basale Zellmembraneinfaltungen — finden sich in allen Kanalabschnitten. Während im Verlauf des Zentralkanals die Oberflächenvergrößerung durch Mikrovilli ziemlich konstant bleibt, findet sich in den Kanalabschnitten, die ausschließlich an Bindegewebe grenzen, eine besonders auffällige und signifikante Zunahme der basalen Oberflächenvergräßerung durch Zellmembraneinfaltungen. Es werden mögliche Besonderheiten im Reabsorptionsmechanismus diskutiert: Möglicherweise läuft zwischen dem Epithel des inneren und des weiten Kanals einerseits und den angrenzenden Canaliculuszellen andererseits ein Kreislaufprozeß für Ionen (recycling) ab.
    Notes: Summary The central canal and the urinary bladder of the leech Hirudo medicinalis (L.) were studied by electron microscopy. The central canal consists of several different parts: the initial, intermediate and terminal canal which border only on connective tissue, and the inner and the wide canal which on the other hand are closely connected to the canaliculus cells which produce the primary urine. Structures related to transcellular transport of solutes such as microvilli and basal plasma membrane infoldings in association with mitochondria have been found in all parts of the central canal. Evidence has been obtained that the surface enlargement by basal plasma membrane infoldings increases from the proximal to the distal parts of the central canal while the luminal surface enlargement remains nearly constant. The increasing basal surface enlargement is especially obvious in those parts of the central canal which border only on connective tissue. The mechanism of reabsorption is discussed with regard to physiological data so far available. A recycling process for solutes may take place between the epithelium of the inner and the wide canal on one hand and the bordering canaliculus cells on the other hand.
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  • 74
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    Cell & tissue research 153 (1974), S. 63-77 
    ISSN: 1432-0878
    Keywords: Smooth muscle ; Intestine ; Afferent fibres ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The innermost layer of the circular musculature of the ileum of the guinea-pig, mouse, rat, rabbit, cat and dog is made of special small and dark muscle cells (sd cells), which can be identified by light and electron microscopy. These cells have a higher surface to volume ratio than ordinary muscle cells. They show all the organelles of smooth muscle cells and are in close relationship with a great number of extrinsic and intrinsic nerve fibres. They send numerous thin cytoplasmic processes towards the bulk of the circular layer, but nexuses between the sd cells and ordinary muscle cells are not found. It is suggested that some of the nerve fibres in this part of the circular layer are motor, setting the sd cells to a given length, and some are afferent in luminal pressure.
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  • 75
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    Cell & tissue research 153 (1974), S. 167-173 
    ISSN: 1432-0878
    Keywords: Parathyroids ; Rana temporaria ; Crystals ; Ultrastructure ; Catalase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Crystalline inclusions in parathyroid gland cell nuclei of Rana temporaria were studied by electron microscopy using a specimen tilting stage. Images were analysed by optical diffraction. Results were compared with X-ray and electron microscopic data of trigonal bovine liver catalase to which a striking resemblance of the inclusions was found.
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  • 76
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    Cell & tissue research 153 (1974), S. 189-193 
    ISSN: 1432-0878
    Keywords: Eyes ; Retinula ; Ephestia kuehniella ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Im Auge von Ephestia kommen Kontakte zwischen den Zellen benachbarter Retinulae vor. Diese Kontakte finden sich am häufigsten in der Kernregion der Retinulazellen und können 2 oder mehr Retinulae miteinander verbinden. Da keine besonderen Membranstrukturen in der Kontaktzone beobachtet wurden und da andererseits die Retinulazellen auf diesem Niveau und weiter distal Pigmentgranula enthalten, scheinen diese Kontakte weder die Zellen chemisch bzw. elektrisch zu koppeln noch Reizlicht zu übertragen. Vielmehr wird angenommen, daß die Verlagerungen des Cytoplasmas bei Hell-Dunkeladaptation in benachbarten Retinulae durch die gegenseitige Berührung koordiniert werden.
    Notes: Summary Connections were found between retinula cells of adjacent retinula cell columns in the eye of Ephestia. The connections occur most frequently at the level of the retinula cell nuclei and may involve two or more retinula columns simultaneously. The absence of specialized structural modifications of the membranes and the presence of pigment granules at the level of the connections or distal to them indicates that these connections are probably not involved in selective chemical or electrical communication nor in light transmission. It is suggested that the connections may serve tactily to coordinate cytoplasmic movement in adjacent retinula columns during light-dark adaptation.
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  • 77
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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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  • 78
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    Cell & tissue research 155 (1974), S. 321-336 
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    Keywords: Muscle fibres (Tadpole tail) ; Degeneration ; Macrophages ; Autophagic vacuoles ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary This report describes histochemical and ultrastructural studies of tail muscles in tadpoles of Rana japonica and Rana catesbeiana during metamorphosis, this process being accompanied by degeneration of the tail. Degeneration of individual tail muscles does not occur at the same time; this is true for both the red and white muscle fibres. The initial phase of degeneration showed mesenchymal macrophages first invading the muscle fibres and then sending out many long cytoplasmic processes which split the fibres apart. The disappearance of myofibrils during degeneration proceeds along at least two different mechanisms even within a single muscle fibre. In one type, the Z-band becomes diffuse and then disappears, resulting in fragmentation of the myofibrils at the sites previously occupied by the Z-bands. The second pattern of degeneration is characterized by disappearance of the Z-band followed by a fanning out of the myofilaments not associated with fragmentation of myofibrils. As atrophy of muscle fibres proceeds, acid phosphatase activity is localized in the perinuclear sarcoplasm. Macrophages show more intense acid phosphatase activity than do the muscle fibres. The formation of autophagic vacuoles is described and discussed.
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  • 79
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    Cell & tissue research 155 (1974), S. 541-554 
    ISSN: 1432-0878
    Keywords: Hypophysectomized rats ; Reorganized stalk ; Ultrastructure ; Salt load
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The reorganized stalk of hypophysectomized rats, either “intact” or subjected to a 6-day salt load, has been studied by light and electron microscopy. PAF-positive neurosecretory material is seen mainly in the periphery of the reorganized stalk, usually in 2–5 μ nerve swellings of animals operated two months before. Nerve swellings make contact with a dense capillary network. Three types of nerve fibres and their swellings are distinguished according to the size of elementary granules. Peptidergic A1 and A2 types contain granules with a maximum diameter of 170 and 130 nm respectively; monoaminergic B type fibres have granules of 100 nm in diameter. A1 type axonal swellings are the most numerous and can be tentatively divided into four subtypes according to their ultrastructure and relationships with capillaries and pituicytes. Swellings of types b and c, making direct contact with capillaries or pituicyte perikarya, usually contain few granules and numerous synaptic vesicles arranged frequently in clusters in the “active” zones. It is assumed that they are especially active in the release of peptide neurohormones. It is also hypothesized that in the hypophysectomized rats peptide neurohormones are released not only directly into the pericapillary space but also into the intercellular cleft, especially at sites of neuron-pituicyte junctions. Nerve swellings of type a, separated from the pericapillary space by thin pituicyte processes, usually contain numerous neurosecretory granules. It is suggested that vascular “end-feet” of pituicytes may somehow reduce neurohormone release. The depletion of PAF-positive material as well as the decreased granule content even after a salt load of only 1 per cent shows that the reorganized stalk is functional as a neurohaemal organ, but has a diminished hormone reserve. This, together with a primitive cytomyeloangioarchitecture speaks for morphological and functional imperfection of the reorganized stalk.
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  • 80
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    Cell & tissue research 148 (1974), S. 203-211 
    ISSN: 1432-0878
    Keywords: Hypothalamus ; Rat ; Supraoptic nucleus ; Ultrastructure ; Somatic spines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Electron microscopic studies of ultrathin serial sections of the perikarya and adjacent neuropil of neurons of the supraoptic nucleus (SON) of the adult male rat revealed varying forms of two types of somatic spines. One type forms synapses with axons passing the cell, the other, without synapses, appears to serve as a buttress or clasp for adjacent neuronal and glial processes. The synapse-bearing spines lack the usual spine apparatus but contain the flocculent substance often seen in spines. The other spines do not exhibit either of these structures. These somatic spines were also seen in Golgi impregnated preparations but the types could not be distinguished. Certain axons synapse either on a somatic spine of the perikarya or penetrate the glial sheath of the neuron and synapse, usually repeatedly, on the soma in an en passant manner.
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  • 81
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    Cell & tissue research 148 (1974), S. 309-311 
    ISSN: 1432-0878
    Keywords: Cecum ; Colon ; Lanthanum ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary After exposure of mouse cecal mucosa to lanthanum during primary fixation in glutaraldehyde, the metal was found as discrete particles covering microvilli and microorganisms, as a continuous layer outlining the lateral surfaces of epithelial cells, and as particles bound to collagen fibrils. The results suggest that lanthanum acts primarily as a stain of the surfaces of certain cells and extracellular structures, and to a lesser extent as an inert probe of the extracellular space.
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  • 82
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    Keywords: Cerebrospinal fluid contacting neurons ; Filum terminale (Cyprinus carpio) ; Ultrastructure ; Synaptic semidesmosomes
    Source: Springer Online Journal Archives 1860-2000
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    Notes: Summary Small nerve cells are scattered among the ependymal cells of the central canal of the filum terminale in Cyprinus carpio. The dendrites of these neurons form bulb-like endings in the cerebrospinal fluid (CSF). These endings are similar to the CSF contacting dendritic terminals of the medulla oblongata and spinal cord. Therefore, we consider these nerve cells to belong to the CSF contacting neuronal system. The axons of these neurons enter the hypendymal fibrous zone where nerve processes of various calibres and axon terminals on dendrite-like profiles and sometimes on ependymal processes were found. In addition to cytoplasmic elements ordinarily present in nerve cells there are granulated vesicles of about 800 to 900 Å in diameter in the perikarya of the CSF contacting neurons. Axons containing synaptic and dense-core vesicles (diameter about 400 Å and 800 Å, respectively) build up synapses on the basal part of these neurons. The CSF contacting neurons described are dissimilar to the Dahlgren cells present in the urophysis and in the rostral part of the filum. In addition, we found axon terminals forming synaptic semidesmosomes on the basal lamina of the external surface of the filum. At some places these terminals are numerous, building up primitive median eminence-like areas on the surface of the filum. In addition to synaptic vesicles these terminals contain numerous granulated vesicles of 800 Å. The axons forming these terminals are supposed to originate from the CSF contacting neurons. The presence of special nerve terminals on the external surface furnishes morphological evidence for the passage of substances from the nervous tissue into the external CSF space at the level of the filum terminale.
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  • 83
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    Keywords: Spleen (Rat) ; Periarteriolar lymphocytic sheath ; Mononuclear phagocyte system (MPS) ; Thymectomy ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Light- and electron microscopic studies reveal that the peri-arteriolar lymphocytic sheath of the rat spleen can be divided into two areas. The central area contains small lymphocytes, interdigitating cells (IDC, light staining cells with extensive cytoplasmic interdigitations) and some scattered reticulum cells. The peripheral area contains a mixed population of lymphocytes and circumferentially oriented reticulum cells. It is shown that only the central area of the peri-arteriolar lymphocytic sheath is thymus-dependent. In neonatally thymectomized rats, before interdigitating cells appear, monocytes and promonocytes reside in this area. It is suggested that the IDC are part of the mononuclear phagocyte system (Langevoort et al., 1970). They probably form the micro-environment necessary for the differentiation and proliferation of T-cells. The analogies between IDC, epithelioid cells and the macrophages in the migration inhibition test are discussed. The hypothesis is put forward that these cells are similar in ultrastructural and functional aspects because all three are macrophages under the influence of humoral factors from T-cells, such as migration inhibition factor.
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  • 84
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    Keywords: Pars tuberalis ; Mammals ; Chicken ; Newt ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The pars tuberalis of the rat, mouse, garden door mouse, European hamster, cat, cattle, chicken and newt is composed of two main cell types: specific secretory cells and follicular cells. The specific cells are characterized by comparable morphologic features in the investigated species, despite differences in the diameter of the secretory granulated vesicles; the ultrastructural morphology of these cells is different from that of any of the known cell types of the adenohypophysis. The follicular cells are devoid of secretory granules, they do not only line the numerous follicular cavities of the pars tuberalis but may also be found in the periphery of the cell cords (border cells). In addition, gonadotrophic cells are found; they predominate in the distal portion of the pars tuberalis and are definitely activated by castration or hypophysectomy. Experimental interventions on most of the major endocrine systems did not cause any noticeable ultrastructural changes in the specific cells. It appears certain that the pars tuberalis secretes a specific hormone whose function remains to be determined.
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    Cell & tissue research 148 (1974), S. 381-396 
    ISSN: 1432-0878
    Keywords: Placenta ; Mouse ; Syncytium ; Morphogenesis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé L'origine embryologique des constituants cytologiques de la barrière placentaire chez la Souris a été mise en évidence du 8ème au 11éme jour de la gestation et la séquence des phénomènes favorisant la formation d'un syncytium trophoblastique, précisée. La barrière placentaire trilaminaire a une double origine: la couche interne provient du trophoblaste chorionique, la couche médiane syncytiale comme la couche externe dérivent du trophoblaste ectoplacentaire. Le stimulus initial de la différenciation semble résulter au 9ème jour du contact entre le trophoblaste chorionique et le mésoderme allantoïdien. Quelques heures après, on observe la réaction des cellules chorioniques, caractérisée par une augmentation importante des nucléoprotéines cytoplasmiques, puis l'apparition de globules lipidiques et enfin des propriétés de motilité. Ces cellules établissent des jonctions complexes avec le trophoblaste ectoplacentaire indifférencié qu'elles côtoient. En même temps, le métabolisme nucléaire de ces cellules ectoplacentaires semble modifié. Ultérieurement, au 10éme jour de la gestation, la disparition des membranes plasmiques latérales de ces cellules, conduit à la formation d'un syncytium par fusion de cellules au même stade d'évolution.
    Notes: Summary The morphogenesis of the different layers forming the mouse placental barrier is described during the 8th to 11th day of gestation. The timing and events leading to the formation of the syncytiotrophoblast are analyzed. Two different processes lead to the formation of the hemotrichorial placental membrane: the internal layer is formed by the chorionic trophoblast, both the intermediate syncytial layer and the external cytotrophoblast layer are derived from the ectoplacental trophoblast. The differentiation of the placental barrier begins on the 9th day of gestation by the establishment of contact between the chorionic trophoblast and the allantoic mesoderm. A few hours later, the chorionic cells show a considerable increase in cytoplasmic nucleoproteins and lipids and become ameboid. Complex cell-junctions differentiate between these chorionic cells and the adjacent ectoplacental trophoblast. On the 10th day of gestation the lateral cytoplasmic membranes disappear leading to the formation of a syncytium.
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    Cell & tissue research 147 (1974), S. 335-351 
    ISSN: 1432-0878
    Keywords: Fenestra dorsalis ; Allanaspides ; Syncarida ; Ion transport ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The genus Allanaspides (Crustacea, Syncarida) is characterised by a conspicuous modification of the cephalo-thoracic tergite, the fenestra dorsalis. The ultrastructure of the fenestra dorsalis was examined in both known species of Allanaspides. The organ is separated from surrounding tissue by a clearly demarcated transition zone in which the cuticle thickens and looses its normal laminated structure. In the cells of the fenestra dorsalis, three regions may be distinguished. The apical region has an abundance of long invaginations, often packed closely together. The invaginations possess numerous microtubules plus numerous mitochondria whose membranes are closely associated with the invaginated membranes. Both microtubules and mitochondria are aligned in the same direction as the invaginations. The middle region of the cells contains many intracellular vacuoles in Allanaspides hickmani whilst in Allanaspides helonomus the same region contains extensive extracellular spaces. The basal region of the cells is marked by deep infoldings and an abundance of mitochondria. Microtubules are common and these, together with the mitochondria, are aligned along the direction of the infoldings. Adjacent cells are linked by frequent septate junctions. The fine structure of fenestra dorsalis tissue indicates an active participation in ion and/or water movement. However, in contrast to other crustacean tissues known to be involved in this function, it is postulated that the fenestra dorsalis of Allanaspides provides a two-stage transport system, in which “mitochondrial pumps” are present on both the inner and outer cell surfaces.
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    Cell & tissue research 148 (1974), S. 143-158 
    ISSN: 1432-0878
    Keywords: Photoreceptor ; Planaria ; Neurotubules ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The photoreceptors of the planarian Dugesia dorotocephala were studied by light microscopy and electron microscopy. The eye was found to be rhabdomeric; it is composed of approximately 25 visual cells and a monolayered cup of pigment cells enclosing the light sensitive rhabdome. The pigment cell gave the appearance of having a phagocytic function in addition to regulating the light entering the rhabdome. Extensions of these pigment cells were shown to be the “membranous structure” seen by light microscopy in the open area of the eye. The bipolar visual cell consisted of a perikaryon, axon and a dendritic extension comprised of a stalk, conical body and microvillous rhabdomere. Efferent nerve fibers formed synapses with dendritic spines protruding from receptor stalks. A specialized structure at the transition area between neurotubules and neurofilaments was observed in the conical body. A dense intercellular space occurred between all regions of adjoining visual cells.
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    Cell & tissue research 149 (1974), S. 223-233 
    ISSN: 1432-0878
    Keywords: Spermatozoon ; Holothuroidea (Leptosynapta clarki) ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
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    Notes: Summary The spermatozoon of the holothurian Leptosynapta clarki has a small circular head measuring about 3.0 μ at the greatest diameter, a midpiece containing a single mitochondrion and a tail flagellum measuring between 35 μ and 45 μ in length. The acrosomal region contains a granule measuring 0.7 μ in diameter which consists of electron dense material arranged in concentric lamellae. Five concentric very electron dense lamellae alternate with areas of much less electron dense material in the central region of the granule. This granule rests in an anterior nuclear depression. The nucleus is circular in shape and contains one or two unbound vacuoles which frequently contain a fine granular material. Posteriorly the nucleus is bounded by a large mitochondrion and an occasional Golgi complex. The proximal centriole which contains a lateral arm of dense material lies in a deep fossa projecting into the nucleus. The distal centriole lies posteriorly in the mitochondrial mass and gives rise to nine satellite projections and their Y-shaped connective extensions. The tail contains the 9 + 2 tubule arrangement and tapers at its distal end.
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  • 89
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    Keywords: Photoreceptors ; Nervous system ; Polychaete ; Ultrastructure
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    Notes: Summary Organs of presumed photoreceptor significance in Nephtys exhibit great simplicity. The pigmented eyes of Nephtys are embedded in the posterior region of the brain. Each consists of a pigment cup and two closely-associated sensory cells. The cells exhibit the characteristic features of rhabdomeric-type photoreceptor structures. The anterior or accessory eyes are identical to the pigmented eyes except that each may consist of only a single cell and that pigment cups are absent. A pair of “sensor sacs” is also present, embedded in the brain. Each consists of a single cell which has the appearance of possessing a large intracellular vesicle (the phaosome) into which project irregularly arranged microvilli. The limiting membrane is, in fact, continuous with the cell membrane. Evidence is presented of the secretion of material of unknown character into the vesicle.
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    Cell & tissue research 149 (1974), S. 333-347 
    ISSN: 1432-0878
    Keywords: Neural lobe ; Mouse ; Growth and development ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
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    Notes: Summary Nerve fibres of the neurosecretory hypothalamo-hypophyseal tract were studied in embryonic C3H mouse neural lobes; at least four glands at each gestational day 15–19 were examined. Single axons and small bundles of fibres are visible at gestational days 15 and 16. By day 17 large fibre bundles penetrate between glial cells. They increase in number during the next two days. Electron-lucent and electron-dense vesicles are seen in the fibres of the 15th and 16th gestational days. In the 17–19 day-old embryos development is characterized by a successive rise in the number of the two types of vesicles. The mean diameter of the electron-lucent vesicles is approximately unchanged in all the stages examined (50 nm). The electron-dense vesicles increase in size from approximately 80–90 nm at days 15–16 to 140 nm at the 19th gestational day. By day 19 contacts between neurosecretory fibre terminals and the outer basement membrane of internal and peripheral capillaries are occasionally observed. The possibly adrenergic nature of a few terminals contacting peripheral vascular structures in 17 and 18 day-old embryos is suggested.
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  • 91
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    Keywords: Supraoptic and paraventricular nuclei ; Ultrastructure ; Osmotic stimulus ; Quantitative study
    Source: Springer Online Journal Archives 1860-2000
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    Notes: Summary Substitution of a 2% solution of sodium chloride in place of drinking water for 3 days significantly increased both the size of neurosecretory neurones in the supraoptic and paraventricular nuclei of rats and the proportion of these cells which had dilated endoplasmic reticulum. There was an increase in the number of multivesicular bodies per mean cell profile and also an increase in the ratio of “dense” (immature) to “pale” (mature) neurosecretory granules within the perikarya, although the total numbers of granules were unchanged. If, after 3 days of saline-treatment, the rats were again allowed tap water to drink for 2 days, the proportion of cells showing dilated endoplasmic reticulum and the number of multivesicular bodies returned towards normal, but there was a significant increase in the number of large dense lysosomal bodies per cell profile and a relative increase in the proportion of “pale” (mature) neurosecretory granules. These changes suggest that the increased bio-synthetic activity resulting from saline-treatment subsides when the treatment is terminated. Furthermore, since neurohypophysial hormone stores have still not returned to normal in animals of the recovery group, they also imply the absence of an internal feedback system by which the level of neural lobe hormone stores might govern the synthetic activity of the neurosecretory cells. Both the increased synthesis, and the increased electrical activity which accompanies it, may be independent consequences of the depleting stimulus.
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    Cell & tissue research 150 (1974), S. 1-9 
    ISSN: 1432-0878
    Keywords: Sensory receptors ; Insects ; Chemoreceptors ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary On the antenna of adult male Periplaneta americana, three size ranges of classical sensilla basiconica were found. Based on SEM, a sensillum of the s. trichodeum shape was revealed, but our TEM efforts indicate that this sensillum has the thin-wall, porous ultrastructure of a sensillum basiconicum. Sensilla basiconica contain flask-shaped cuticular pores. All viewed pores join four or five tubules. The pore tubules clearly contact plasma membranes of dendritic branches. Two sizes of grooved pegs were observed. The terminal segment of the antenna contains a variety of other “receptors”.
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  • 93
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    Keywords: Neurosecretion ; Harvestman ; Exocytosis ; Release ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé Les plaques paraganglionnaires de l'Opilion Trogulus nepaeformis sont des organes neurohémaux constitués d'une lamelle neurale externe, épaisse, en contact avec un sinus sanguin, d'une couche basale de cellules gliales, et de 7 types de terminaisons axonales (A1, A2, B1, B2, B3, B4 and C) renfermant des granules élémentaires qui diffèrent par leur taille, leur densité aux électrons et l'aspect de leur contenu. Les granules de type A1 se déchargent par exocytose dans l'espace extra-axonal, sous la lamelle neurale; ceux de type C se fragmentent en microgranules à contenu dense qui s'accumulent avec des vésicules claires contre l'axolemme en des places suggérant des sites de libération dans l'hémolymphe.
    Notes: Summary The paraganglionic plates of the harvestman, Trogulus, are neurohemal organs composed of a thick neural lamella facing a blood sinus, basal glial cells, and seven distinct types of axon terminals (A1, A2, B1, B2, B3, B4 and C) identified on the basis of elementary granule size, electron density, and structure of contents. The release of A1 type granules occurs by exocytosis into the extraaxonal space below the acellular neural lamella. The release of the content of C granules occurs after fragmentation into small electron dense vesicles. Clusters of these vesicles intermixed with clear vesicles pressing against the axolemma beneath the neural lamella, apparantly correspond to the sites of release.
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  • 94
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    Cell & tissue research 150 (1974), S. 343-368 
    ISSN: 1432-0878
    Keywords: Fertilization ; Gametes ; Echinoid ; Echinarachnius ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The morphology of gametes of a representative echinoid, Echinarachnius parma were investigated ultrastructurally with particular emphasis on gamete interaction during fertilization. The acrosomal region of the spermatozoon is characterized by the presence of two components: an acrosomal vesicle and periacrosomal materials. The acrosomal vesicle, which is completely bounded by a limiting membrane, is surrounded by periacrosomal materials. Nuclear and mitochondrial regions of the spermatozoon are also described briefly. The ovum is surrounded by two extraneous coats: an outer jelly layer and an inner vitelline envelope. Pigment cells are present within the outer jelly layer. Ooplasmic organelles and inclusions including cortical granules and the female pronucleus are described. Spermatozoa undergo the acrosomal reaction in the vicinity of mature ova. Events of acrosomal reaction, including dehiscence of the acrosomal vesicle and acrosomal tubule formation, are described and summarized schematically. Acrosomal vesicle contents remain adherent to the outer surface of the tubule membrane. Primary binding of the spermatozoon to the surface of the ovum is accomplished by the establishment of morphological continuity between this extracellular coat and the vitelline envelope of the ovum. It is suggested that the species specificity of fertilization resides in this primary binding of gametes. Membrane fusion, between the tip of the acrosomal tubule and the colemma, follows primary binding and cytoplasmic continuity of the gametes is thereby established. It is concluded that the early events of fertilization in Echinarachnius parma generally conform to the Hydroides-Saccoglossus pattern of the Colwins (1967).
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  • 95
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    Cell & tissue research 151 (1974), S. 395-402 
    ISSN: 1432-0878
    Keywords: Heart ; Teleost ; Sarcoplasmic reticulum ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The morphology of the sarcoplasmic reticulum in myocardial cells of the ventricle of the trout heart is described as the result of an investigation with the electron microscope. The sarcoplasmic reticulum is sparse in distribution compared to that of birds or mammals but shows a fundamentally similar organization. A very loose network of fine tubules is in intimate contact with the myofibrils but with no local modification with respect to the arrangement of myofilaments within the sarcomeres. There is no special association of the sarcoplasmic reticulum with the Z-bands. Some tubules pass to the cell periphery where they expand to form subsarcolemmal cisternae in which electron-dense matter is often seen. The occurrence of the subsarcolemmal cisternae (peripheral couplings) is random and they are not observed in the vicinity of intercalated discs. The sarcoplasmic reticulum is discussed in relation to excitation-contraction coupling in teleost myocardial cells, and in comparison with that of other vertebrates.
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  • 96
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    Cell & tissue research 152 (1974), S. 193-217 
    ISSN: 1432-0878
    Keywords: Imaginal fat body ; Calliphora erythrocephala ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary During the first egg-maturation period (6 days at 25° C) the adult fat body of the female of Calliphora goes through sequential changes correlated with the development of the oocytes. The first two days represent a growth and differentiation phase. Free ribosomes and rough endoplasmic reticulum (RER) gradually increase in quantity. Golgi complexes consisting of clusters of vesicles and vacuoles appear to bud off from cisternae of the RER. Dense bodies possibly arise by sequestration from Golgi complexes. Content of acid phosphatase shows the dense bodies to be lysosomes. Many contain crystalloids. Glycogen is first seen as a network, in which gamma-elements appear; later alpha-particles occur. Lipid droplets are abundant. Lipid droplets break down where they border upon glycogen. In four-day old females the fat body is in a phase of production. Golgi complexes concentrate protein secretion granules believed to represent yolk protein. Then follows a phase of regression characterized by the formation of cytosegresomes and by an accumulation of lipid. In mature females a remodeling of the fat cell begins, evidenced by a renewed formation of free ribosomes, RER, and probably dense bodies resembling those of the one-day old female.
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  • 97
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    Cell & tissue research 152 (1974), S. 219-228 
    ISSN: 1432-0878
    Keywords: Vitelline cells ; Dugesia lugubris (Turbellaria, Tricladida) ; Yolk material ; Ultrastructure ; Cytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The development of vitelline cells in the fresh-water Triclad Dugesia lugubris has been studied by means of electron microscopic and cytochemical techniques. We observed a single cell type in different stages of development more or less evenly distributed from the periphery towards the centre of the follicles. Young vitelline cells have the characteristic morphology of cells in early stages of maturation: they show a large nucleus, a nucleolus with fibrillar and granular components, and many ribosomes in an undifferentiated cytoplasm. Subsequently, large amounts of parallel arrays of granular endoplasmic reticulum and some Golgi complexes appear and the vitelline cells assume the typical appearance of secretory cells. Reserve substances progressively accumulate in the vitelline cells, which when mature appear very electron dense. We have recognized the following types of reserve substances: 1) Neutral lipid droplets which are the first to appear and can reach a diameter of 4–5 μm or more. 2) Yolk globules of 2–3 μm in diameter which appear simultaneously with cocoon-shell globules but are clearly different from them in structure and chemical composition. The yolk globules probably arise from the cooperation between endoplasmic reticulum and Golgi complexes and have a very complex proteinaceous nature. 3) Large amounts of α-glycogen granules which occupy cytoplasmic sacs.
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  • 98
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    Cell & tissue research 153 (1974), S. 517-530 
    ISSN: 1432-0878
    Keywords: Medial preoptic area ; Hypothalamus ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The neuronal and glial cell bodies and the neuropil of the medial preoptic area of the rat hypothalamus were studied under the electron microscope. Two different types of neurons are identified on the basis of electron density. These two types differed in a number of ultrastructural features. Three types of nerve terminals based on vesicle morphology are also described, as well as the general structure of the axons, dendrites and synapses in the neuropil. The structure of oligodendrocytes and astrocytes is also discussed.
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  • 99
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    Cell & tissue research 154 (1974), S. 39-49 
    ISSN: 1432-0878
    Keywords: Gobius jozo (Teleost) ; Testis ; Steroidogenic tissue ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The homologue of mammalian Leydig cells in the testis of fish of the genus Gobius is believed to be a glandular mass lying along the mesorchium and quite distinct from the seminiferous region. This gland was studied in Gobius jozo by light and electron microscopy. Histologically, the gland is composed of cords of polyhedral cells located between the main vessels of the testis and the deferent duct. Dark and light cell varieties were observed both after staining with toluidine blue and with respect to their cytoplasmic electron density. The fine structure of the glandular cells is characterized by a well developed agranular endoplasmic reticulum in the form of random anastomosing tubules and vesicles and by very numerous mitochondria with tubulo-vesicular cristae. In some mitochondria the internal organization is paracrystalline. One or two bodies of unknown nature are Found in the Golgi region. They are partially limited by an unusually thick membrane and contain a material subdivided mostly into small vesicles. Liposomes and lipofuscin pigment granules are also present. The ultrastructural features of the glandular cells of the testis of Gobius jozo confirm a specialization in steroid hormone production.
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  • 100
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    Cell & tissue research 154 (1974), S. 211-230 
    ISSN: 1432-0878
    Keywords: Pituitary ; Goldfish ; Cell types ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the goldfish, Carassius auratus, morphological and functional aspects of the pituitary gland were studied at the ultrastructural level and six cell types could be distinguished in the pars distalis. Acidophilic cells of the rostral pars distalis were identified as prolactin cells, the chromophobic cells of the rostral pars distalis as ACTH cells, the non-globular basophilic cells of the rostral and the proximal pars distalis as TSH cells, the globular basophils of the proximal pars distalis as gonadotropic cells and the acidophils of the proximal pars distalis as somatotrophs. Besides some of the well established criteria of morphological and functional identification of different cell types, two new approaches have been used in the present study. One was to express the electron density of secretory granules objectively by means of a photometric method. It was found that both types of acidophilic cells which produce the proteohormones prolactin and somatotropin respectively, had granules with the highest electron densities. The basophilic cells producing the glycoproteins gonadotropin and TSH respectively, possessed granules of intermediate electron density whereas the chromophobic cells storing the peptide hormone ACTH had granules of lowest densities. The second new approach was the administration of the synthetic mammalian releasing hormones LH-RP and TRF, which helped in identifying gonadotropic and thyrotropic cells respectively. In the goldfish there is evidence for the presence of only one type of gonadotropic cell.
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