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  • Rat  (85)
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  • Amsterdam ; Boston : Elsevier
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  • 1985  (217)
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  • 2005-2009
  • 1985-1989  (217)
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  • 1
    Digitale Medien
    Digitale Medien
    Springer
    Computing 35 (1985), S. 85-91 
    ISSN: 1436-5057
    Schlagwort(e): 65M05 ; 65M10 ; 65M25 ; Second order ; characteristic difference schemes ; quasilinear hyperbolic systems ; stability
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Informatik
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Wir stellen ein Charakteristikenverfahren zweiter Ordnung für die numerische Lösung der Anfangswertaufgabe von quasilinearen hyperbolischen Systemen vor und beweisen die Stabilität des Verfahrens für Systeme mit konstanten Koeffizienten.
    Notizen: Abstract We present two-step, second-order explicit characteristic difference schemes for the numerical solution of initialvalue problems for quasilinear hyperbolic system and show that the method is stable for systems with constant coefficients.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    Springer
    Computing 35 (1985), S. 325-344 
    ISSN: 1436-5057
    Schlagwort(e): 65L05 ; Numerical analysis ; Nyström methods ; stiff problems ; stability
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Informatik
    Beschreibung / Inhaltsverzeichnis: Abstract The stability of adaptive Nyström-Runge-Kutta procedures is studied for a wide class of nonlinear stiff systems of second order differential equations. We show that for a large class of semi-discrete hyperbolic and parabolic problems the restriction of the stepsize is not due to the stiffness of the differential equation. Furthermore we use the scalar test equation $$y'' = - \omega ^2 y + q \cdot e^{iv(t - t_0 )} $$ to derive conditions which ensure that the numerical forced oscillation is in phase with the analytical forced oscillation. The order of adaptive Nyström-Runge-Kutta methods (with a stability-matrix based on a diagonal Padéapproximation) for which the forced oscillation is in phase with its analytical counterpart cannot be greater than two. This barrier of order is not true forr-stage implicit Nyström methods of orderp=2r.
    Notizen: Zusammenfassung Für eine umfangreiche Klasse nichtlinearer steifer Differentialgleichungssysteme zweiter Ordnung wird die Stabilität adaptiver Nyström-Runge-Kutta-Verfahren untersucht. Wir zeigen, daß für eine große Klasse semidiskretisierter hyperbolischer und parabolischer Probleme die Restriktion der Schrittweite unabhängig von der Steifheit des Differentialgleichungssystems ist. Weiterhin verwenden wir die skalare Testgleichung $$y'' = - \omega ^2 y + q \cdot e^{iv(t - t_0 )} $$ und geben Bedingungen dafür an, daß die numerische erzwungene Schwingung mit der analytischen erzwungenen Schwingung in Phase ist. Die Konsistenzordnung adaptiver Nyström-Runge-Kutta-Verfahren (mit einer Stabilitätsmatrix, die auf einer diagnolen Padé-Approximation beruht), für die die erzwungene Schwingung mit ihrem analytischen Gegenstück in Phase ist, kann nicht größer als zwei sein. Diese Ordnungsbarriere gilt nicht fürr-stufige implizite Nyström-Methoden der Ordnungp=2r.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    Springer
    Fire technology 21 (1985), S. 22-33 
    ISSN: 1572-8099
    Schlagwort(e): Fire resistance ; standard test ; effective load ; restraint ; stress ; concrete ; collapse load ; structural elements ; insulation ; thermal reaction ; composite elements
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Architektur, Bauingenieurwesen, Vermessung
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    Springer
    Entomologia experimentalis et applicata 39 (1985), S. 73-79 
    ISSN: 1570-7458
    Schlagwort(e): Lepidoptera ; Pyralidae ; Chilo partellus ; Sorghum ; phototaxis ; climbing ; leaf anatomy ; surface wax
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Résumé Une étude du comportement ascentionnel de chenilles néonates de Chilo partellus a montré que la phototaxie positive oriente l'insecte vers le sommet de la plante d'une façon plus importante que le site de ponte à la base du sorgho. La phototaxie est perdue après la pénétration dans le verticille, sous les effets combinés de l'odeur de l'hôte et de l'obscurité. Des insectes qui s'égarent sur les feuilles doivent retourner sur la tige pour parvenir à atteindre le verticille, et on a observé que les arêtes des feuilles, les épines orientées distalement et les cires de l'hôte provoquent ensemble une réorientation vers le bas de la feuille d'où l'ascension peut être poursuivie. II y a des différences suivant les cultivars en relation avec ces facteurs qui sont la cause partielle des différents niveaux de résistance à ce ravageur.
    Notizen: Abstract A study of the mechanisms by which the newly hatched larvae of Chilo partellus reach the whorl from the oviposition site at the base of the plant is presented. A strong positive phototaxis is of primary importance. Reorientation is necessary, however, if larvae stray out onto leaves. Edge spines and leaf waxes are important in reorientation to the culm so that the climb can be continued. There are cultivar differences in relation to these factors which are a partial reason for different levels of resistance to this pest.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 5
    Digitale Medien
    Digitale Medien
    Springer
    Cellular and molecular life sciences 41 (1985), S. 265-266 
    ISSN: 1420-9071
    Schlagwort(e): Rat ; hydrochlorothiazide ; pain threshold ; antinociceptive activity ; analgesic activity ; morphine
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Hydrochlorothiazide, acutely injected in rats, has a weak analgesic activity per se and potentiates and prolongs the antinociceptive effect of morphine.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 6
    Digitale Medien
    Digitale Medien
    Springer
    Cellular and molecular life sciences 41 (1985), S. 24-29 
    ISSN: 1420-9071
    Schlagwort(e): Pieridae ; Lepidoptera ; systematics ; evolution ; enzyme electrophoresis ; genetic differentiation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Enzyme electrophoretic data show a remarkably high degree of genetic similarity within the European group ofnapi s.l. whereas genetic differences exist at several loci between the European and the North American taxa ofnapi s.l. It is concluded that the European taxa did not differentiate to the species level and form a phylogenetically young group. The North American taxa included in this study are specifically distinct from Europeannapi and separated much earlier. Within these North American taxamarginalis, oleracea andvirginiensis did undergo speciation. The data show a splitting of the genusPieris into three species groups, each genetically differentiated to the same level. The splitting ofPieris into two genera, as suggested by earlier investigators, is not supported here.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 7
    Digitale Medien
    Digitale Medien
    Springer
    Entomologia experimentalis et applicata 37 (1985), S. 13-16 
    ISSN: 1570-7458
    Schlagwort(e): spruce budworm ; Choristoneura fumiferana ; Lepidoptera ; Tortricidae ; calling behavior ; sex pheromone ; bioassay
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Résumé Des expériences ont été menées au laboratoire pour examiner si la phéromone sexuelle synthétique de C. fumiferana pouvait altérer le comportement d'appel de femelles vierges de la même espèce. Un appareil a été conçu pour libérer alternativement — à des intervalles déterminés — un courant d'air portant de la phéromone sexuelle ou un courant d'air pur, dans plusieurs flacons contenant des femelles vierges. Le comportement sexuel de mouches de 0 et 2 jours a ainsi été observé. Indépendamment de l'exposition des femelles à la phéromone, il y avait deux pics quotidiens d'activité d'appel, l'un dans l'après-midi et l'autre après le crépuscule. Des papillons exposés au 1×10−6 mg ou 1×10−3 mg de phéromone avaient un premier pic d'appel au moins antérieur de 2 heures par rapport aux témoins. Ainsiily a vait un plus grand nombre de papillons engagés dans une activité d'appel en présence de la phéromone que chez les témoins.
    Notizen: Abstract The calling behaviour of 0-day-old and 2-day-old virgin female eastern spruce budworm moths, Choristoneura fumiferana (Clem.) was observed during exposure to different concentrations of the synthetic female sex pheromone. Regardless of whether the females were exposed to pheromone or not, there were two daily peak periods of calling activity, one in the afternoon and the other after dusk. Those moths exposed to pheromone commenced calling at least 2 h earlier during their first peak of calling activity. Also, a greater number of moths engaged in calling when exposed to pheromone than those under control conditions.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 8
    ISSN: 1570-7458
    Schlagwort(e): European corn borer ; Ostrinia nubilalis ; Pyralidae ; Lepidoptera ; azadirachtin ; antifeedant ; botanical insecticide
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Résumé On a examiné les propriétés anti-appétantes et insecticides de l'azadirachtine, une substance triterpénoïde provenant d'Azadirachta indica envers la pyrale du maïs Ostrinia nubilalis. La concentration effective pour causer 50% d'inhibition de l'alimentation larvaire (PC50) sur des disques foliaires a été de 3.5 ppm pour les larves de premier stade et de 24 μg/8 pour celle de troisième stade. L'azadirachtine a sévèrement réduit la croissance larvaire à des concentrations de 1 et 10 ppm dans une diète méridique et, éventuellement, a causé 100% de mortalité à 10 ppm et 90% à 1 ppm. A 0.1 ppm l'azadirachtine n'a pas eu d'effet significatif sur les larves maïs a modifié l'indice de masculinité en faveur des mâles au moment de l'émergence et a empêché l'oviposition chez les femelles. Les indices nutritionnels pour les larves naïves de troisième âge et celles ayant subi une accoutumance suggèrent que la réduction de croissance est le résultat d'une intoxication comme le démontre une efficacité réduite de transformation chez les groupes traités à l'azadirachtine, plutôt que des changements de digestibilité. Il n'y a pas d'évidence claire de tolérance dans le groupe ayant subi l'accoutumance. Les résultats suggèrent qu'à 10 ppm l'azadirachtine est un insecticide botanique efficace envers O. nubilalis.
    Notizen: Abstract Azadirachtin, a triterpenoid substance from the neem tree, Azadirachta indica A. Juss., Meliaceae, was evaluated for its antifeedant and insecticidal properties to the European corn borer Ostrinia nubilalis Hübner. The 50% protective concentration for larval feeding on treated corn disks (PC50) was 3.5 ppm for neonate larvae and 24 ppm for third instar larvae. Azadirachtin severely reduced larval growth at 1 and 10 ppm in a meridic diet and eventually caused 100% mortality at 10 ppm and 90% at 1 ppm. At 0.1 ppm azadirachtin showed no significant effect on larvae but altered the sex ratio in favor of male moths during adult emergence and arrested oviposition of female moths. Nutritional indices for naive and habituated third instar larvae suggested that reduction of growth was due to toxicity as shown by a lowered efficiency of conversion in the azadirachtin treated groups, rather than changes in digestibility. No clear evidence of tolerance was observed in the habituated group. The data suggest that at 10 ppm azadirachtin is an effective botanical insecticide for control of O. nubilalis.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 9
    ISSN: 1570-7458
    Schlagwort(e): kairomone ; frass ; Microplitis demolitor ; Heliothis zea ; Trichoplusia ni ; host selection ; behavior ; Hymenoptera ; Lepidoptera
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Résumé Microplitis demolitor, un parasitoïde solitaire de plusieurs espèces de chenilles de noctuelles, a été introduit d'Australie aux Etats-Unis comme agent potentiel de contrôle biologique. Les fèces des chenilles d'Heliothis zea et Trichoplusia ni élevées sur des cotyledons de pois (Pink Eye Purple Hull Cowpea) stimulent les femelles à sélectionner un hôte, mais les fèces des chenilles des deux espèces élevées sur diète CSM ne possèdent pas cette activité. Un extrait hexanique des fèces des chenilles de H. zea élevées sur cotyledons de pois stimule également ce comportement, de même que le 13-methylhentriacontane, substance présente dans les fèces des chenilles de H. zea (Jones et al., 1971). Les femelles de M. demolitor exposées immédiatement avant leur lâcher en serre aux fèces des chenilles de H. zea, nourries de cotyledons de pois, parasitent un plus fort pourcentage (41.7%) de chenilles de H. zea que cells qui n'ont pas été exposées aux fèces (13.9%). Le comportement de sélection de l'hôte des femelles de M. demolitor est donc semblable à celui des femelles de Microplitis croceipes, un parasitoïde étroitement apparenté indigène des Etats-U-nis. La femelle, par exemple, est stimulée par une kairomone des fèces des larves de H. zea nourries sur des cotyledons de pois (incluant le 13-methyl-hentriacontane), la diète affecte l'activité kairomonale des fèces, et une exposition préalable aux fèces avant le lâcher stimule le comportement de sélection de l'hôte. La stimulation du comportement de sélection de l'hôte, au moment du lâcher peut être utilisée pour améliorer l'efficacité des lâchers des parasitoïdes dans les programmes de contrôle biologique.
    Notizen: Abstract Microplitis demolitor Wilkinson, a solitary larval parasitoid of several species of Noctuidae, has been imported into the United States from Australia. A closely related species, Microplitis croceipes (Cresson), is native to the United States. The host-selection behavior of M. demolitor females is similar to that of M. croceipes in that it is stimulated by kairomones (including 13-methylhentriacontane) in the frass of Heliothis zea (Boddie) larvae, larval diet affects the kairomonal activity of the frass, and exposure to frass prior to release stimulates host-selection behavior. M. demolitor females also respond to frass from Trichoplusia ni (Hübner) larvae that had fed on Pink Eye Purple Hull Cowpea cotyledons.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 10
    Digitale Medien
    Digitale Medien
    Springer
    Entomologia experimentalis et applicata 39 (1985), S. 177-182 
    ISSN: 1570-7458
    Schlagwort(e): biological control ; brassica ; labiate herbs ; larval feeding ; oviposition ; Lepidoptera ; Pieris brassicae ; Plutella xylostella
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Résumé Des plantes médicinales ont traditionnellement été utilisées en association avec des plantes cultivées dans l'espoir que leur odeur repousserait les insectes nuisibles. Des extraits à l'alcool et des essences volatiles de labiées médicinales ont été essayés au laboratoire pour examiner leur effets répulsif et dissuadant pour la ponte de Plutella xylostella et l'alimentation des chenilles de P. xylostella et Pieris brassicae. Les extraits alcooliques d'hysope, de romarin, de sauge, de thym et de trèfle blanc réduisent la ponte de P. xylostella sur des morceaux de feuilles de chou traitées. Les essences volatiles de sauge et de thym réduisent la ponte de P. xylostella sur des morceaux de feuilles de chou dans des expériences de choix. L'alimentation des chenilles de dernier stade de P. xylostella et P. brassicae dans des expériences de choix est réduite par l'application d'extraits alcooliques des labiées médicinales.
    Notizen: Abstract Herbs have been traditionally used as intercrops with crop plants on the assumption that their odour repels pest species. Alcohol extracts and essential oils of labiate herbs were tested in the laboratory for deterrent/repellent responses to ovipositing Plutella xylostella (L.) and feeding larvae of P. xylostella and Pieris brassicae L. Alcohol extracts of hyssop, rosemary, sage, thyme and white clover reduce oviposition by P. xylostella on pieces of brassica leaf in dual-choice tests. Essential oils of sage and thyme reduce oviposition on pieces of brassica leaf. Feeding, in dual-choice tests, by final instar P. xylostella and P. brassicae larvae is reduced by application of alcohol extracts of herbs.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 11
    Digitale Medien
    Digitale Medien
    Springer
    Entomologia experimentalis et applicata 39 (1985), S. 233-239 
    ISSN: 1570-7458
    Schlagwort(e): Adoxophyes orana ; Lepidoptera ; Tortricidae ; strain ; sex pheromone ; sex gland components ; Z9-14:Ac ; Z11-14:Ac ; mating disruption ; spermatophores ; population density
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Résumé Des essais ont été effectués en laboratoire en mettant des couples de papillons d'Adoxophyes orana F.v.R. pendant une semaine dans des boîtes d'élevage de 1,25 l avec ou sans composantes phéromonales. A la fin de l'essai, les femelles sont disséquées pour la recherche des spermatophores. L'inhibition des accouplements s'accroît avec l'augmentation de la charge des deux composantes principales de l'attractif, le Z9-14:Ac et le Z11-14:Ac (9:1) et elle décroît lorsque la densité de popultion passe de 1 à 5, 10, 20 couples de papillons par boîte. Chacune de ces deux composantes principales isolée provoque une réduction d'accouplements aussi importante que le mélange lui-même. Les composantes mineures Z9-12:Ac et 12:Ac ont pratiquement la même efficacité que les composantes principales, mais le 14:Ac et le Z11-14:OH sont sans effet. Des essais identiques effectués avec une souche d'A. orana récemment introduite en élevage continu, montrent qu'il suffit d'environ dix fois moins d'attractif pour provoquer le même effet que sur l'ancienne souche. Parallèlement à l'adaptation aux conditions d'élevage, le nombre de femelles non accouplées dans les témoins diminue progressivement et la fréquence des accouplements multiples augmente. II est donc vivement recommandé de travailler avec des souches continuellement renouvelées en élevage, ou avec les descendants directs d'individus prélevés en vergers. Les résultats obtenus sont commentés en relation avec la lutte par la technique de confusion.
    Notizen: Abstract Couples of Adoxophyes orana F.v.R. were isolated for one week in small 1.25 l rearing boxes in the laboratory with sex gland components deposited on rubber caps. At the end of the trials females were dissected and spermatophores counted. Reduction of mating increased with the dose of a mixture of the attractant components Z9-14:Ac and Z11-14:Ac (9:1) but decreased with increasing density of 1 to 5, 10 and 20 couples per box. Each of the attractant components alone produced a mating inhibition equal to the mixture. The minor components Z9-12:Ac and 12:Ac had approximately the same effect as the main components, but 14:Ac and Z11-14:OH had no effect. Identical trials conducted on a strain of summerfruit moth newly introduced to our rearing showed that ten times less product was needed to achieve the same degree of mating inhibition as with the old strain. With adaptation to laboratory conditions the proportion of unmated females diminished and repeated matings occurred more frequently. In order to achieve meaningful results one must work with material from regularly renewed rearings, or better with the direct descendants of individuals from orchards. The results are discussed in relation to mating disruption of A. orana in orchards.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 12
    ISSN: 1570-7458
    Schlagwort(e): Scrobipalpopsis solanivora ; Lepidoptera ; Gelechiidae ; sex pheromone ; (E)-3-dodecenyl acetate ; (Z)-3-dodecenyl acetate
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Résumé S. solanivora est l'un des plus importants lépidoptères détruisant les pommes de terre en Amérique Centrale. L'analyse par chromatographie en phase gazeuse (GC) des produits obtenus par lavage de l'ovipositeur de femelles vierges, associée à des électro-anténnogrammes (EAG) a révélé un composé actif unique en EAG. Les durées de rétention pour ce constituant correspondaient à celles des acétates monoinsaturés à 12 carbones, et les analyses sur colonne GC liées avec une phase liquide cristal ont montré un pic principal correspondant à l'acétate (E)-3-dodécénul et un pic secondaire, correspondant à l'isomère Z, et au niveau de 2,5% du pic principal. L'acétate dodécyl a aussi été décelé en quantités variables, approximativement 10% du pic principal. Dans la nature, des pièges contenant de l'acétate (E)-3-dodécényl, seul ou mélangé avec 1 ou 2% de l'isomère Z, ont capturé autant des mâles de S. solanivora que des pièges contenant des femelles vierges, et certaines indications montrent que l'addition de 5% de l'isomère Z réduit les captures.
    Notizen: Abstract The sex pheromone produced by virgin female S. solanivora moths has been shown to contain (E)-3-dodecenyl acetate with approximately 2% of the Z isomer by electroantennography and gas chromatography. In the field, traps baited with (E)-3-dodecenyl acetate alone or in combination with 1% or 2% of the Z isomer caught at least as many male S. solanivora moths as those baited with virgin female moths, and there was some evidence that addition of 5% of the Z isomer reduced catches.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 13
    Digitale Medien
    Digitale Medien
    Springer
    Entomologia experimentalis et applicata 37 (1985), S. 193-198 
    ISSN: 1570-7458
    Schlagwort(e): host plants ; larval feeding ; phenols ; proteins ; water contents ; nutritional quality ; fecundity ; egg hatchability ; Diacrisia casignetum ; Arctiidae ; Lepidoptera
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Résumé L'étude a porté sur l'évaluation de l'influence des feuilles de tournesol (Helianthus annuus) et de Mikana cordata sur le développement, la fécondité et l'éclosion des oeufs de D. casignetum Kollaz. La durée de développement et le gain de poids sur tournesol étaient plus importants que sur M. cordata. La durée de développement était statistiquement hétérogène (P〈0.05), ce qui peut être dû à des différences entre plantes. La fécondité et le taux d'éclosion chez les insectes élevés sur tournesol étaient plus élevés que ceux observés sur M. cordata, dont les résultats étaient aussi hétérogènes (P〈0.1 et〈0.05 respectivement). Les feuilles de M. cordata contenaient des taux relativement élevés de phénols et des rapports protéines sur phénols bas. Tout ceci suggère que les différences observées sont attribuables à des variations dans la qualité nutritive de ces hôtes et dans l'incorporation à la biomasse de l'insecte de matériaux phénologiques ingérés.
    Notizen: Abstract Measurements were made of the differences between sunflower and climbing hempweed leaves for development, fecundity and egg hatchability of Diacrisia casignetum Kollar. Developmental time and weight gains of sunflower-fed larvae were respectively longer and greater than those of hempweed-fed ones. The development time and weight gain, attributable to differences in host plants, were statistically heterogeneous (P〈0.05-〈0.10). Relative fecundity and egg hatchability of sunflower reared insects were greater than those of hempweed reared ones, and these were also statistically heterogeneous (P〈0.1 and 〈0.05, respectively). Hempweed leaves contained relatively high titres of phenols and low ratios of proteins to phenols. Ovaries were heavier in insects reared on sunflower than on hempweed, whereas the level of phenols incorporated into the ovary was higher in insects fed on hempweed than those on sunflower. The differences in these parameters may be due to variations in nutritional quality of these hosts and incorporation of ingested phenolic materials to ovary and insect biomass.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 14
    Digitale Medien
    Digitale Medien
    Springer
    Entomologia experimentalis et applicata 39 (1985), S. 21-26 
    ISSN: 1570-7458
    Schlagwort(e): Lepidoptera ; Pieridae ; Pieris ; cabbage ; oviposition deterrents ; host selection
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Die Eiablage von Pieris rapae auf Kohl wurde gehemmt von einem Homogenisat aus Kohlblättern, das auf intakte Pflanzen gesprüht wurde. Ether-Extrakte der Kohlblätter wirkten im Gegensatz zu Wasserextrakten abschreckend. Ebenso zeigten Hexanextrakte anderer Wirtspflanzen eine hemmende Wirkung auf die Eiablage, während Wasserextrakte anderer Wirtspflanzen keine Wirkung aufwiesen. Dagegen aber verhinderten sowohl polare als auch unpolare Extrakte von Nicht-Wirtspflanzen die Eiablagen. Polare, abschreckende Substanzen in den Nicht-Wirtspflanzen Erysimum cheiranthoides und Capsella bursa-pastoris (Cruciferae) könnten Ursache dafür sein, dass P. rapae diese Pflanzen meidet. Chemische Substanzen mit sowohl abschreckender als auch stimulierender Wirkung spielen offensichtlich eine bedeutende Rolle für legebereite Schmetterlingsweibchen bei der Auswahl von Pflanzen als geeigneten Eiablageplatz.
    Notizen: Abstract Oviposition by Pieris rapae L. on cabbage was deterred by homogenized cabbage tissue sprayed onto intact plants. Ether extracts of cabbage also were deterrent, but water extracts were not. Hexane extracts of other host plants deterred oviposition and water extracts had little or no effect. Polar as well as non-polar extracts of non-host plants inhibited oviposition. Polar deterrents in the non-host crucifers, Erysimum cheiranthoides and Capsella bursa-pastoris may explain the avoidance of these plants by P. rapae. Chemical deterrents, as well as stimulants, apparently play a major role in the acceptance or rejection of plants as hosts by ovipositing female butterflies.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 15
    ISSN: 1570-7458
    Schlagwort(e): (E,Z)-2,13-octadecadien-1-ol acetate ; (Z)-13-octadecen-1-ol acetate ; Synanthedon tipuliformis ; currant borer ; Lepidoptera ; Sesiidae ; sex pheromone
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung (E,Z)-2,13-Octadecadienylacetat und (Z)-13-Octadecenylacetat wurden in Ovipositor-Extrakten des Johannisbeerglasflüglers Synanthedon tipuliformis kapillar-gaschromatographisch nachgewiesen. Die Strukturen wurden mittels Gaschromatographisch-Massenspektrometrie bestätigt. Das Verhältnis Dien/Monoen im Extrakt betrug 93:7. Mischungen der beiden Komponenten wie auch (E,Z)-2,13-Octadecadienylacetat allein lockten im Freiland Männchen dieser Glasflüglerart an.
    Notizen: Abstract (E,Z)-2,13-octadecadien-1-ol acetate and (Z)-13-octadecen-1-ol acetate have been identified from the ovipositor extracts of the currant borer, Synanthedon tipuliformis (Clerck), by capillary GC, and the structures were verified by GC-MS. The diene/monoene ratio in the extract was found to be 93:7. Mixtures of these two compounds as well as the diene alone attracted conspecific males in the field.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 16
    Digitale Medien
    Digitale Medien
    Springer
    Development genes and evolution 194 (1985), S. 429-432 
    ISSN: 1432-041X
    Schlagwort(e): Tail bud ; Tail gut ; Gut ; Organogenesis ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The formation of the tail portion of the primitive gut was investigated by light and electron microscopy in 10- and 11-day rat embryos. The observations permit the conclusion that the tail gut does not form as a posterior extension of the hindgut but originates from the tail bud mesenchyme by mechanism analogous to the secondary neurulation. It includes cell condensation, aquisition of apicobasal polarity and the radial, rosette-like arrangement around a central cavity. These cells bear the cytological characteristics of both the absorptive epithelial cells and the mesenchymal cells at their apical (adluminal) and abluminal ends respectively.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 17
    Digitale Medien
    Digitale Medien
    Springer
    Cellular and molecular life sciences 41 (1985), S. 267-269 
    ISSN: 1420-9071
    Schlagwort(e): Diapause ; oligopause ; sugarcane borer ; Diatraea saccharalis ; Lepidoptera ; Pyralidae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Sugarcane borers enter a state of delayed metamorphosis when exposed to a 12-h photophase at 21°C. Larval feeding, growth, and molting continues but pupation is suppressed under these conditions.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 18
    ISSN: 1420-9071
    Schlagwort(e): Rat ; alloxan diabetes ; intestinal villus ; alkaline phosphatase ; sucrase ; epithelial cells ; villus-crypt axis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The sucrase activity in enterocytes isolated from the villus crypt axis was found to increase in all regions of the villus from day 2 after induction of diabetes, and the increase continued until day 4. In contrast, alkaline phosphatase activity increased mainly in the apical one-third of the villus-crypt column, and the increase occurred abruptly on day 4 with increase in food intake.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 19
    Digitale Medien
    Digitale Medien
    Springer
    Cellular and molecular life sciences 41 (1985), S. 273-275 
    ISSN: 1420-9071
    Schlagwort(e): Rat ; embryo ; embryo ; rat ; β-hydroxybutyrate ; diabetes ; maternal ; fetal malformation ; malformation ; fetal ; ketone bodies
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In order to investigate further the relationship between maternal diabetes and fetal malformation, rat embryos were grown in vitro in the presence of β-hydroxybutyrate, one of the ketone bodies produced by diabetics. At 10 mM, β-hydroxybutyrate produced minor abnormalities and at 20 mM it produced major abnormalities in rat embryos.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 20
    Digitale Medien
    Digitale Medien
    Springer
    Cellular and molecular life sciences 41 (1985), S. 1123-1127 
    ISSN: 1420-9071
    Schlagwort(e): Serotonin ; acetylcholine ; corticosterone ; ACTH ; CRF ; Brattleboro rat ; stress
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary It has been proposed that the central serotonergic inputs which modulate pituitary-adrenal secretion are mediated by cholinergic neurons. We have tested this hypothesis in intact rats. Male Sprague-Dawley rats were injected with cholinergic and serotonergic agents which enhanced transmitter function and with receptor blocking agents. Agents were injected, singly and in combination, into both unstressed and stressed animals. Since the response to cholinergic agents might be due to changes to vasopressin release, Brattleboro (vasopressin deficient) rats were also injected with cholinergic agents. The level of plasma corticosterone at 1-h post-injection was determined. Results indicate that the serotonin receptor blockade decreased the stimulatory, cholinergic effect of physostigmine. Cholinergic receptor blockers did not significantly reduce the corticosterone rise induced by 5-hydroxytryptophan. These results do not support the hypothesis of cholinergic mediation of serotonergic input. Nicotinic and muscarinic receptors appeared to exert opposing influences on the system. The nicotinic receptor antagonist was able to block the stimulatory effect of physostigmine. The muscarinic receptor antagonist significantly elevated plasma corticosterone levels. No differences were found in the effect of physostigmine on Brattleboro rats as compared to controls. These data are interpreted as suggesting that 1) the acetylcholine-induced stimulation of pituitary-adrenal function is mediated, in part, by serotonergic neurons; and 2) stimulation of nicotinic receptors is facilitatory whereas stimulation of muscarinic receptors is inhibitory to pituitary-adrenal function.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 21
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 29 (1985), S. 207-210 
    ISSN: 1432-1041
    Schlagwort(e): metoclopramide ; enalapril ; aldosterone secretion ; dopamine receptors ; hypertension
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary To assess if dopaminergic control of aldosterone secretion is mediated by the renin-angiotensin system, the effect of chronic angiotensin converting enzyme inhibition by enalapril on the aldosterone response to metoclopramide has been studied in 10 patients with mild to moderate essential hypertension. Enalapril reduced supine blood pressure and increased the heart rate significantly. Plasma renin activity and urinary sodium excretion rose significantly. PRA was not changed by metoclopramide, neither during placebo nor during enalapril treatment. Metoclopramide induced a two-fold increase in plasma aldosterone, the peak response being reached within 15 min. Enalapril treatment did not alter the aldosterone response to metoclopramide. Dopaminergic control of aldosterone secretion appears to be independent of the renin-angiotensin system.
    Materialart: Digitale Medien
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  • 22
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 29 (1985), S. 215-219 
    ISSN: 1432-1041
    Schlagwort(e): penbutolol ; renal impairment ; beta-adrenoceptor blocking agents ; metabolism ; hypertension ; pharmacokinetics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The pharmacokinetics of penbutolol, its 4-hydroxylated metabolite and of their conjugates was studied in hypertensive patients with various degrees of renal impairment. A single oral dose of penbutolol 40 mg, was rapidly absorbed after a lag-time of 0.34 h. Its plasma concentration reached a maximum after 0.84 h and then declined bi-exponentially, with an apparent elimination half-life of 21.8 h. The hydroxylation of penbutolol was negligible and conjugation was of major importance for its elimination. Consequently, the kinetics of unchanged penbutolol were not altered by renal impairment. The 48 h-urinary excretion of penbutolol and its metabolites reached 13–14% of the administered dose, which is consistent with extensive metabolism of the drug. After treatment for 30 days with penbutolol 40 mg/d there was no accumulation of the parent drug but the concentration of its conjugates was increased. It is concluded that the dose of penbutolol need not be changed in patients with mild renal insufficiency, 4-hydroxypenbutolol is unlikely to participate in the anti-hypertensive effect of the drug, due to its low concentrations, and biotransformation of penbutolol may be enhanced during chronic treatment.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 23
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 29 (1985), S. 383-389 
    ISSN: 1432-1041
    Schlagwort(e): felodipine ; hypertension ; calcium antagonist ; vasodilator ; side-effects
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary Felodipine, a selective arteriolar dilator, was given to 13 hypertensive patients to assess its hypotensive effects and duration of action. Nine patients were treated with 5 mg three times a day and 4 with 10 mg three times a day. Mean blood pressures fell with both treatment regimens: 5 mg placebo 170/103 mmHg; 5 mg felodipine 148/91 mmHg; 10 mg placebo 154/93 mmHg; 10 mg felodipine 137/82 mmHg. Heart rates increased as blood pressures fell with both treatments. However, in the patients given 5 mg three times a day this effect was less noticeable after successive doses. Plasma concentrations of noradrenaline, both resting and tilted, increased after felodipine. There was a negative correlation between the fall in blood pressure and the increase in noradrenaline, suggesting that those patients with good baroreceptor reflexes were better able to counteract the effects of vasodilatation. Four of the nine patients treated with 5 mg felodipine three times a day experienced mild and transient adverse effects. Of the four patients treated with 10 mg three times a day, three experienced moderate to severe headache, and for this reason recruitment into this group was stopped. Felodipine at a divided daily dose of 15 mg effectively lowered blood pressure.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 24
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 29 (1985), S. 395-399 
    ISSN: 1432-1041
    Schlagwort(e): Ro 31-1118 ; cardioselectivity ; hypertension ; pharmacokinetics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary Five patients with mild hypertension were given single oral doses of Ro 31-1118 (10, 20, 40, and 80 mg) and placebo in a randomized, double-blind, within-patient study. Plasma concentrations of Ro 31-1118 and supine, standing, exercise, and post-exercise heart rates and blood pressures were measured before and at regular intervals after drug administration. The pharmacokinetic data were consistent with a one-compartment model with first-order absorption and a variable time lag. Peak plasma concentrations and area under curve were linearly related to dose, whereas time to peak concentration, half-time, clearance and apparent volume of distribution were dose-independent. There was a reduction in exercise and post-exercise heart rate of approximately 10% after 10 mg and 20 mg Ro 31-1118, and of approximately 15% after 40 mg and 80 mg. At all doses standing systolic blood pressure was reduced by approximately 5%. A similar fall was seen in exercise and post-exercise systolic blood pressures. There was no substantial effect of Ro 31-1118 on supine or standing heart rates nor on diastolic blood pressure. No adverse effects were reported. It is concluded that Ro 31-1118 has linear pharmacokinetics over the dose range 10–80 mg, and has a weak antihypertensive effect when administered in single doses to patients with mild hypertension.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 25
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 29 (1985), S. 401-403 
    ISSN: 1432-1041
    Schlagwort(e): endralazine ; hypertension ; once daily dosing ; atenolol ; propranolol
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary We report the first placebo controlled parallel group study of once daily endralazine (5–20 mg) in hypertension uncontrolled by a beta-blocker plus a diuretic. Following a 4-week run-in period 22 patients with a sitting mean arterial pressure (MAP) greater than 110 mm Hg were entered into the study and received either endralazine 5 mg or placebo. Blood pressure was measured 2 h and 24 h after dosing and the drug dose doubled at 2 and 4 weeks if the 24-h MAP remained 〉110 mg Hg. The final blood pressure assessment was made after 6 weeks treatment in the 19 patients who completed the study. Three patients withdrew from the study because of side effects. The hypotensive effect (sitting) was in excess of placebo at 2 h by 15.8 mm Hg systolic (NS), 15.4 mm Hg diastolic (p〈0.01), 15.5 mm Hg MAP (p〈0.02) and at 24 hours by 7.7 mm Hg systolic (NS), 8.9 mm Hg diastolic (p〈0.02) and 11.1 mm Hg MAP (p〈0.02). This study suggests that endralazine should be prescribed twice daily.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 26
    ISSN: 1432-1041
    Schlagwort(e): hypertension ; labetalol ; prazosin ; hydrochlorothiazide ; side-effects ; therapeutic efficacy ; atenolol
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary After screening two local populations in the northern part of The Netherlands for hypertension, patients with a diastolic pressure (DP) between 95 and 120 mmHg were treated daily either with 50 mg hydrochlorothiazide or 100 mg atenolol. Non-responders were given the combination and if necessary the dose of atenolol was increased to 200 mg. Non-responders to the latter combination were randomized and treated either with 50 mg hydrochlorothiazide and labetalol or with 50 mg hydrochlorothiazide, 200 mg atenolol and prazosin. If after 1 month a DP≤90 mmHg had been reached the patient was reassessed after a further 3 months. If a DP〉90 mmHg was found the dose of labetalol or prazosin was increased and the patient was re-examined after 1 month. This protocol was followed until the maximum dose was reached or adverse reactions prevented a further increase in dosage. During 6 months of treatment there was a further drop in systolic and diastolic blood pressures under both regimens of, respectively, 8.6 and 2.4 mmHg for labetalol, and 7.7 and 5.0 mmHg for the prazosin group. At the end of the period the average daily doses of labetalol and prazosin were 1256 mg and 4.3 mg, respectively. There was no significant difference in the average number of complaints between the labetalol and the prazosin group.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 27
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 28 (1985), S. 501-505 
    ISSN: 1432-1041
    Schlagwort(e): hypertension ; indenolol ; submaximal workload ; haemodynamic effects ; side-effects
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The effect of indenolol on heart rate and blood pressure at rest and after submaximal workload has been studied in 19 patients with established essential hypertension. A stepwise increase from moderate to submaximal exercise was chosen to mimic challenges normally occurring in daily life. After 4 weeks of once a day indenolol therapy a significant, gradual reduction in the following cardiovascular parameters was observed: heart rate at rest fell by 20%, 30% after exercise and 31% after recovery; systolic blood pressure showed a fall of 15% at rest, 19% after workload and 14% after recovery; the reduction in diastolic blood pressure was 15% at rest, 11% after exercise and 12% after recovery. The rate-pressure product was decreased by 32% at rest, 43% after exercise and 42% after recovery. It is concluded that the most important pharmacological effect of indenolol is the significant decrease in myocardial oxygen demand. In patients with essential hypertension indenolol not only produces a definite antihypertensive effect, but it also increases workload tolerance and decreases subjective symptoms during physical activity. Compliance was good and no severe side effects were observed.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 28
    ISSN: 1432-1041
    Schlagwort(e): prazosin ; alphamethyldopa ; lipoprotein ; hypertension ; blood lipids ; serum parameters ; hydrochlorothiazide
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The effects of prazosin and alphamethyldopa on blood lipids and lipoproteins were assessed in 20 patients with mild or moderate arterial hypertension. Parameters measured included serum cholesterol (CHO), triglycerides (TG), high density lipoprotein-cholesterol (HDL-CHO), insulin (I), glucose (G), and non-esterified fatty acids (NEFA). Prazosin — 4 mg/day for 6 weeks in hydrochlorothiazide-treated patients lowered blood pressure by 18.6/17.2 (systolic/diastolic pressure) mmHg. There was a significant decrease in CHO (−5.8%), in I (−16.5%), and in NEFA (−3.0%), and a significant increase in HDL-CHO (+15.5%). Alphamethyldopa 250–750 mg/day for 6 weeks in hydrochlorothiazide-treated patients lowered blood pressure by 18.8/14.6 (systolic/diastolic pressure) mmHg, accompanied by a non-significant decrease in CHO and TG, and significant increases in HDL-CHO (+10.3%), G (+8.5%) and NEFA (+6.4%). Thus, prazosin appears to have a more beneficial effect on blood lipids and lipoproteins than alphamethyldopa.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 29
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 28 (1985), S. 659-664 
    ISSN: 1432-1041
    Schlagwort(e): BTS 49465 ; hypertension ; pharmacokinetics ; blood pressure effect ; heart rate effect ; side-effects ; healthy volunteers
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The pharmacokinetic and haemodynamic effects of a 200 mg oral dose of BTS 49465 (7-fluoro-1-methyl-3-methylsulphinyl-4-quinolone) were investigated in a double-blind placebo controlled study. BTS 49465 was rapidly absorbed and cleared from the systemic circulation with a half-life of 1.6 h by oxidation to the sulphone metabolite. The metabolite was cleared with a half-life of 37.6 h. Saliva concentrations of both BTS 49465 and its metabolite correlated well with the plasma concentrations. Compared to placebo, BTS 49465 produced statistically significant reductions in blood pressure and increases in heart rate both supine and after a 60° head up tilt. The time course of the haemodynamic changes suggested that the sulphone metabolite contributed to the overall hypotensive response. Plasma Renin Activity was only marginally elevated and there was no evidence of acute fluid retention. BTS 49465 was well tolerated in terms of haematological and biochemical parameters and subjective side-effects.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 30
    ISSN: 1432-1041
    Schlagwort(e): captopril ; hydrochlorothiazide ; hypertension ; vascular reactivity ; norepinephrine ; angiotensin II
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The effect on arterial pressure of incremental doses of norepinephrine (2 to 10 µg/min) and angiotensin II (50 to 800 ng/min) administered over 10 min periods was studied in sodium-replete hypertensive patients after crossover oral treatments with placebo, captopril 50 mg in a single dose, captopril 50 mg three times daily for one week and hydrochlorothiazide 50 mg daily for a week. Neither captopril nor hydrochlorothiazide affected the dose response to infusions of angiotensin II. In comparison to placebo responses, however, both single and multiple-dose captopril therapy, and hydrochlorothiazide attenuated the pressor responses to infusions of norepinephrine. Captopril significantly depressed angiotensin converting enzyme activity from predose levels and angiotensin II infusions significantly elevated plasma aldosterone concentrations. These results confirm findings reported for single dose captopril in normotensive volunteers and indicate that attenuation of the vascular responsiveness to sympathetic stimulation may contribute to the antihypertensive effects of captopril and hydrochlorothiazide therapy.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 31
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 28 (1985), S. 85-88 
    ISSN: 1432-1041
    Schlagwort(e): debrisoquine oxidation ; metoprolol metabolism ; oxidation phenotype ; β-blockade ; hypertension
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary After a single 200 mg oral dose of metoprolol tartrate the mean metoprolol AUC was found to be six-fold higher in poor metabolizers (PMs) of debrisoquine than in extensive metabolizers (EMs). This was associated with impaired metabolic clearance via α-hydroxylation and O-dealkylation. A population study (n=143) has shown a bimodal distribution in the ratio of metoprolol: α-hydroxymetoprolol recovered in urine which was correlated highly with the debrisoquine metabolic ratio. Nine per cent of the population were PMs. Plasma metoprolol concentrations three hours after a 100 mg oral dose of metoprolol were greater than 200 ng/ml in PMs but were lower than this in most EMs. This dose of metoprolol given once daily provided a clinically significant reduction (16%) in exercise heart rate in PMs after 24 hours. EMs require conventional doses (100 mg b.d.) to achieve the same degree of β-blockade. Preliminary data from family studies support the view that the defect in metoprolol oxidation is inherited. In 12 hypertensive patients who were EMs we compared the β-blocking activity and antihypertensive effect of chronic treatment with metoprolol 200 mg once daily (conventional and long-acting formulations), with those of atenolol 100 mg once daily and placebo. The effects of all active preparations were similar at 3.5 hours but atenolol was superior to all metoprolol formulations at 24 hours after dosing. It is concluded that for the majority of patients metoprolol should be prescribed twice daily when using currently available dosage forms. Relationships between oxidation phenotype and side-effects should be examined.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 32
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 28 (1985), S. 97-99 
    ISSN: 1432-1041
    Schlagwort(e): atenolol ; β-blockers ; reaction time ; stress ; alertness ; blood pressure ; car driving
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The effects of atenolol were investigated in car drivers participating in an amateur car rally. Atenolol or placebo were administered to two groups of 20 crews (driver and assistant) in this double-blind randomized trial. When compared with placebo, there was no deterioration in subjective appraisal of alertness and reaction ability in subjects given atenolol, and stress symptoms were markedly reduced. When compared with previous experience, the incidence of improved subjective appraisal of general driving ability was higher with atenolol (30 reports) than with placebo (5 reports). Furthermore the incidence of unchanged or worsened driving ability was significantly higher (p〈0.001) with placebo (34 reports) than with atenolol (9 reports). At the end of the rally (16 hours after administration) subjects receiving atenolol 50 mg had significant reductions in heart rate (p〈0.001), diastolic pressure (p〈0.01), and systolic pressure (p〈0.01) when compared with placebo.
    Materialart: Digitale Medien
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  • 33
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 28 (1985), S. 125-130 
    ISSN: 1432-1041
    Schlagwort(e): hypertension ; clonidine ; beta-blocker ; renal failure ; side-effects ; blood pressure decrease ; cardiovascular complications ; atenolol ; propranolol
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The risk of cardiovascular and fatal complications and the antihypertensive effect of a clonidine-β-blocker combination was studied in 98 patients and was compared with the results for a group of patients treated with other antihypertensive regimens. The profile of complications was similar in the two groups for a total follow-up period of more than 2000 treatment-months. Clonidine in combination either with propranolol or atenolol had a distinct antihypertensive effect. However, clonidine plus atenolol resulted in a more immediate and pronounced fall in blood pressure. It is concluded that the combination of clonidine and a β-blocker is an effective antihypertensive medication, and that patients treated with it are apparently at no greater risk of serious cardiovascular incidents than are those treated with other regimens.
    Materialart: Digitale Medien
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  • 34
    ISSN: 1432-1041
    Schlagwort(e): atenolol ; hypertension ; side-effects ; dose-response relationship ; initial treatments
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary After screening a local population in the northern part of The Netherlands for hypertension, 59 patients with a diastolic pressure (DP) between 95 and 130 mmHg were randomized and treated either with 50 mg atenolol (n=29) or 100 mg atenolol (n=30) for 1 month. There was no significant difference between the two treatments, neither in the fall in systolic and diastolic pressures nor in the number of complaints reported. It is concluded that in the initial treatment of uncomplicated mild to moderate hypertension, 100 mg atenolol has no advantage over a 50 mg dose.
    Materialart: Digitale Medien
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  • 35
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 28 (1985), S. 375-380 
    ISSN: 1432-1041
    Schlagwort(e): pinacidil ; hypertension ; dialysis ; vasodilator ; side-effects
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary In an open study, thirteen chronic dialysis patients with nonvolume dependent uncontrolled hypertension were treated with pinacidil for a mean period of 43 weeks. Seven patients were taking concomitant antihypertensive therapy. Twelve patients achieved long-term blood pressure control on a mean dose of 33 mg/day. The baseline supine blood pressure was 184/116 mmHg. After 1 week it had fallen to 161/95 mmHg and blood pressure control was maintained over the study period. Patient weight remained stable. The baseline reading was 61.6 kg and at the end of the study it was 59.7 kg. Pulse rate did not change significantly. For the eight patients not taking beta-blockers the mean change in pulse rate was 7.6 beats/min supine and 6.3 beats/min erect (NS). Pretrial urea and creatinine were 27.6 mmol/l and 1027 µmol/l and after 25 weeks they were 29.6 mmol/l and 1087 µmol/l, respectively (NS). Four patients had ECG evidence of left ventricular hypertrophy before the study and one on completion of the trial. Five patients showed correction of T-waves on their ECG's. Six patients experienced side effects, none of which warranted withdrawal of treatment. These findings suggest that pinacidil is a valuable alternative treatment for hypertensive dialysis patients.
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  • 36
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 28 (1985), S. 381-386 
    ISSN: 1432-1041
    Schlagwort(e): pinacidil ; renal impairment ; hypertension ; vasodilator ; side-effects
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary Twenty patients with uncontrolled hypertension were treated with pinacidil for a mean period of 43 weeks (range 10–63 weeks). All patients achieved and maintained significant reductions in blood pressure. The supine blood pressure at base-line was 184/116 mmHg; after one week it was 161/95 mmHg and at 43 weeks it was 138/79 mmHg. The mean dose of pinacidil was 30 mg/day. There was no significant difference between the two groups with respect to the dose of pinacidil or the blood pressure response. Pulse rate and weight remained stable for the group as a whole. Five patients were not taking beta-blockers. The mean baseline pulse rate for this group was 78 beats/min and when maintained on pinacidil it was 82 beats/min (NS). Six patients were not taking diuretics. The mean baseline weight for this group was 78.5 kg and while maintained on pinacidil it was 79.2 kg (NS). There was no occurrence of oedema, hirsutism or first dose phenomenon. The mean glomerular filtration rate and renal plasma flow for the renal group was 35.4 ml/min and 192.3 ml/min before pinacidil and after six months they were 32.7 ml/min and 183.2 ml/min (NS) respectively. Six patients experienced minor side-effects. We conclude that pinacidil is a potent, well tolerated antihypertensive agent which merits further study.
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  • 37
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 28 (1985), S. 607-609 
    ISSN: 1432-1041
    Schlagwort(e): growth hormone ; valproate ; GABA ; stress ; exercise ; healthy volunteers ; GABAergic transmission
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The effect of the GABAergic drug sodium valproate (SV) on the exercise-induced release of growth hormone (GH) was investigated in 10 healthy males. The exercise test consisted of using a stationary bicycle ergometer at 450 kg/min for 20 min. SV 600 mg blunted the increase in GH induced by the exercise, suggesting GABAergic regulation of GH secretion in man, at least under certain physiological conditions.
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  • 38
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 28 (1985), S. 495-499 
    ISSN: 1432-1041
    Schlagwort(e): pinacidil ; hypertension ; plasma catecholamines ; plasma renin activity ; diuretic drugs ; side-effects ; hydrochlorothiazide ; amiloride
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary Pinacidil, a new cyanoguanidine derivative, is an antihypertensive agent with arteriolar vasodilating properties, which acts on precapillary resistance vessels. A trial was carried out in 30 patients with essential hypertension WHO I-II. The treatment period was divided into three phases. Hydrochlorothiazide (HCTZ) and amiloride were administered for 4 weeks in Phase 1 and supine and standing blood pressure decreased significantly. During Phase 2 pinacidil was added to HCTZ/amiloride for the following 3 months. A further significant reduction in blood pressure was obtained. In the next period of treatment (Phase 3) patients were divided into two groups. For 1 month Group A (15 patients) received pinacidil alone and Group B (15 patients) received HCTZ/amiloride. Conventional laboratory blood tests in all patients remained unchanged during treatment. Reported side effects during Phase 2 were headache (2 patients), dizziness (3 patients), palpitations (2 patients) and ankle oedema (2 patients). Plasma renin activity was slightly increased at the end both of Phases 1 and 2. Plasma catecholamines were increased but not significantly at the end of Phase 2 as compared to Phase 1. The results indicate that pinacidil is effective in lowering blood pressure in mild to moderate essential hypertension.
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  • 39
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 28 (1985), S. 89-91 
    ISSN: 1432-1041
    Schlagwort(e): atenolol ; pindolol ; sleep disturbance ; β-blockers ; dreaming ; fatigue ; hypertension ; lipophilicity
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary This randomized crossover out-patient study was designed to compare the antihypertensive effects of atenolol and pindolol. After a wash-out period of two weeks in pretreated cases, 107 patients with essential hypertension were given either atenolol 100 mg once-daily or pindolol 20 mg slow release (SR) once-daily. Both atenolol and pindolol lowered blood pressure over the 24 week period. The diastolic blood pressure reduction was significantly greater (p〈0.01) with atenolol than with pindolol. Before β-blocker therapy, many patients had already experienced side-effects such as fatigue, sleep disturbances and dreams. This probably relates to the high sensitivity of the analogue scale used to assess side-effects, and to the high incidence of such symptoms in untreated patients. As the study progressed there was a reduction in the frequency of fatigue (p〈0.03) and dreams (p〈0.05) in both groups, whereas sleep disturbances significantly increased under pindolol (p〈0.05) but decreased under atenolol (p〈0.05). The only important side-effect difference between the two β-blockers was the higher incidence of sleep disturbances with pindolol which may be due to the higher lipophilicity of this β-blocker.
    Materialart: Digitale Medien
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  • 40
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 28 (1985), S. 11-15 
    ISSN: 1432-1041
    Schlagwort(e): prazosin ; hypertension ; concurrent medication ; side-effects ; dose frequency ; slow release formulation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary In 20 patients with long-standing essential hypertension, a comparison was made in a randomized cross-over study of the effect of once and twice daily prazosin administration on blood pressure levels. Concurrent medication (beta-blocker and/or saluretic once daily) remained constant throughout the study. Blood pressure measurements were carried out by a nurse using a Hawksley random zero sphygmomanometer, both in the clinic and at home, and using a Roche Kontron Arteriosonde SR-2 at home. Observations made in the morning and in the evening showed no significant difference in blood pressure between the once and twice daily treatments. Eight patients complained of dizziness and faintness half an hour after taking the once daily dose. However, they felt quite well on the twice daily regimen. The mean daily dose in these 8 patients was prazosin 8.4 mg, range 6–12 mg. No indication was found that the subjective adverse side effects were correlated with the serum prazosin level. The complaints noted may possibly be overcome by taking the once daily dose late in the evening, just before retiring. Better still, the development of a slow-release formulation for daily dosages of 6 mg and over is suggested.
    Materialart: Digitale Medien
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  • 41
    ISSN: 1432-1041
    Schlagwort(e): nifedipine ; acebutolol ; hypertension ; combination therapy ; double-blind study ; adverse effects ; BAYl 5240
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary 116 patients from 4 clinics participated in a double blind study to assess the efficacy of (BAYl 5240), a nifedipine-acebutolol fixed combination (10 mg+100 mg), as compared to nifedipine 20 mg in essential hypertension. During the 10 week study, the mean recumbent blood pressure decreased 1 to 3 h after treatment from 175.5/105.2 to 148.3/88.0 mmHg in the BAY1 5240 group and from 174.3/102.9 to 150.3/86.5 mmHg in the nifedipine group. The results also showed a comparable decrease in the mean systolic (SBP) and diastolic (DBP) blood pressures before treatment (24 h after last tablet) and after physical exertion before and after either drug given for 4 weeks. Doubling of the dose for 4 additional weeks produced a moderate and similar additional decrease in blood pressure. The results show the possibility of treating essential hypertension with a low dose of a beta-adrenergic blocking agent in combination with 10 mg nifedipine. Both regimens were well tolerated. One patient in the BAYl 5240 group and 2 in the nifedipine group, all treated by the same investigator, were withdrawn from the study because of headache during the nifedipine pre-period.
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  • 42
    ISSN: 1432-1041
    Schlagwort(e): bromocriptine ; hypertension ; plasma catecholamines ; 3,4-dihydroxyphenylacetic acid ; peripheral dopamine receptors
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The effect of a single oral dose of bromocriptine 2.5 mg was evaluated in 11 normotensive and 6 hypertensive volunteers. 150 min after drug administration, a significant decrease in plasma noradrenaline concentration from 202 to 124 pg/ml in normotensive and from 197 to 119 pg/ml in hypertensive patients was observed. Plasma 3,4 dihydroxyphenylacetic acid, a major metabolite of dopamine, fell from 1132 to 956 pg/ml in normal subjects and from 1242 to 807 pg/ml in hypertensives. No change in plasma adrenaline was found. At the same time, mean arterial pressure showed a significant decrease from 90 to 81 and from 132 to 111 mmHg in normotensive and hypertensive subjects, respectively. Bromocriptine also inhibited the increase in noradrena-line level that occurred when the subjects changed from the supine to the standing position. The inhibition was more evident in hypertensive subjects. It is suggested that the hypotensive effect of bromocriptine is mediated by the inhibition of noradrenaline release due to the stimulation of dopamine receptors on noradrenergic nerve terminals.
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  • 43
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 27 (1985), S. 697-700 
    ISSN: 1432-1041
    Schlagwort(e): piretanide ; hypertension ; glucose tolerance ; loop diuretics ; insulin secretion ; insulin binding ; C-peptide ; glycohaemoglobin A1
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The effect of a new diuretic, piretanide, on glucose tolerance, insulin secretion and 125I-insulin binding to erythrocytes was studied in 12 male patients with mild essential hypertension. After a 4 week wash-out period with placebo, piretanide 6 mg b.i.d. was administered in a single-blind manner for 8 consecutive weeks. Although glucose tolerance deteriorated slightly in one patient, the diuretic treatment had no effect on the mean blood glucose concentrations during oral glucose tolerance tests or on glyco-haemoglobin A1 measurements, both studies being done at 4 week intervals. Preservation of euglycemia was associated with increased insulin secretion. After 8 weeks of piretanide therapy the basal C-peptide concentration was 61% higher than the pretreatment level (0.44 vs 0.71 µU/ml; p〈0.05). Glucagon — stimulated C-peptide concentrations were significantly elevated after 4 (1.67 vs 2.53 µU/ml, p〈0.05) and after 8 weeks (1.67 vs. 2.90 µU/ml, p〈0.01) of diuretic treatment. Fasting plasma immunoreactive insulin (IRI) levels were virtually unchanged by the drug therapy. The enhanced insulin secretion did not appear secondary to increased insulin resistance at the insulin receptor level, since the specific bound fraction of 125I-insulin remained unaffected by diuretic treatment. Although short-term loop diuretic treatment appears to have no effect on glucose tolerance, the very low density lipoprotein synthetic rate may be promoted by the increased insulin secretion.
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  • 44
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 29 (1985), S. 33-36 
    ISSN: 1432-1041
    Schlagwort(e): cold sensitivity ; hypertension ; alpha- and beta-blockade
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The presence of cold sensitivity was investigated in three groups of patients; untreated hypertensives and hypertensives treated by a beta-adrenoceptor blocker (propranolol) or by a combined alpha-and beta-adrenoceptor blocker (labetalol) at two ambient temperatures. At a comfortable ambient (24°C) one-third of the untreated and those treated with beta-blockade only showed cold sensitivity as compared with 16% of patients on the combined therapy. Under conditions of mild cold stress (20°C) cold sensitivity increased in frequency in all three groups, more than half of the untreated and beta-blocked patients were affected and greater than one-third of those with alpha- and beta-blockade. These findings indicate that in the general population of hypertensives treatment with beta-adrenoceptor blockade alone may have little effect on the peripheral vasculature and that a useful degree of protection may be provided by therapy which blocks both receptors.
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  • 45
    ISSN: 1432-1041
    Schlagwort(e): enalapril ; ACE inhibitor ; hypertension ; haemodynamic effects ; renin-angiotensin system
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The haemodynamic effects of enalapril (EN), a new, long-acting, nonsulphhydryl converting enzyme inhibitor, were evaluated by non-invasive methods in 10 adult patients with mild to moderate essential hypertension (EH). Patients were randomly assigned, double blind to 2 treatment groups (EN 20 mg o.d. or 10 mg b.d.) for 4 weeks, and were crossed over to the other dosage regimen after a 2-week washout period. Measurements included mean arterial pressure (MAP), heart rate (HR), cardiac output (CO), limb blood flow (LBF), plasma aldosterone (ALD), plasma renin activity (PRA) and systolic time intervals (STI). Both regimens (b.d. and o.d.) significantly reduced MAP (15.3% and 16.3%, respectively), total peripheral resistance (20.3% and 21.8%, respectively), limb vascular resistance (24.1% and 24.9%) and ALD (33.5% and 36.9%) and increased CO (7.8% and 8.7%), LBF (10.9% and 11.6%) and PRA (10.4% and 9.5%). No significant change was observed in HR or STI. EN 20 mg o.d. or 10 mg b.d. reduced arterial pressure to a similar extent through a fall in total peripheral resistance. An increase in CO was also observed.
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  • 46
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 29 (1985), S. 21-24 
    ISSN: 1432-1041
    Schlagwort(e): nisoldipine ; nifedipine ; pharmacokinetics ; pharmacodynamics ; calcium channel blocking drugs ; hypertension ; side-effects
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The pharmacodynamic and pharmacokinetic profiles of nifedipine and nisoldipine were compared in a double blind, placebo-controlled study. Nisoldipine, 10 mg significantly reduced systolic blood pressure but nifedipine 20 mg retard did not, although both drugs had significant pharmacodynamic effects as evidenced by increased heart rates. The terminal elimination half-life in plasma was similar for both drugs with a mean of 2 h. The pharmacodynamics of nisoldipine were studied in 8 hypertensives following both acute and chronic administration. Antihypertensive efficacy was demonstrated after acute dosing and was maintained over 4 weeks of twice daily treatment as monotherapy.
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  • 47
    ISSN: 1432-1041
    Schlagwort(e): cianergoline ; hypertension ; dopaminergic agonist ; renin angiotensin aldosterone ; lipid metabolism ; benign essential hypertension ; side-effects ; prolactin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary Cianergoline is a new dopaminergic agonist with a predominant cardiovascular action. Its effects on blood pressure, the renin-angiotensin-aldosterone axis, the sympathetic nervous system and lipid metabolism were assessed in 20 patients with benign essential hypertension. Cianergoline given in increasing doses for 4 weeks (maximum daily dose 12±2 mg (SD)) and placebo both caused a slight decrease in arterial pressure, (from 159/104 to 152/98 mm Hg and from 154/104 to 149/103 mm, respectively; difference not significant). Supine and upright plasma renin activity, plasma aldosterone, norepinephrine, epinephrine and dopamine levels, urinary catecholamine excretion rates as well as serum prolactin, low and high density cholesterol and triglyceride concentrations were not changed after cianergoline or placebo. Total serum cholesterol and triglyceride levels decreased significantly after placebo, but were unchanged after cianergoline. 3 out of 10 patients in the cianergoline group complained of nausea. The findings indicate that the new dopaminergic agonist cianergoline exerts only a mild blood pressure lowering effect in patients with essential hypertension and does not modify the release of prolactin, lipid metabolism or the basal activity or postural responsiveness of the renin-angiotensin-aldosterone axis and of the sympathetic nervous system.
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  • 48
    ISSN: 1432-1041
    Schlagwort(e): verapamil ; hypertension ; renal haemodynamics ; glomerular filtration ; arginine vasopressin ; renal function
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary Renal plasma flow, glomerular filtration rate plasma angiotensin II, aldosterone and arginine vasopressin, free water clearance, blood pressure and body weight in 11 patients with mild to moderate hypertension were determined at the end of consecutive 6 week periods of administration of placebo and verapamil up to 120 mg t.i.d. Verpamil induced a 10% reduction in diastolic blood pressure. Compared with placebo none of the other parameters measured changed after treatment with verapamil. There was no significant correlation between blood pressure and arginine vasopressin in plasma. It is concluded that verapamil reduced blood pressure by vasodilatation without activation of the counterbalancing mechanisms commonly seen after treatment with vasodilating drugs, i.e. tachycardia, activation of the renin-angiotensin-aldosterone system, water and salt retention, and without affecting renal haemodynamics. AVP does not seem to be involved in blood pressure regulation in mild to moderate essential hypertension.
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  • 49
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 29 (1985), S. 263-267 
    ISSN: 1432-1041
    Schlagwort(e): nifedipine ; prazosin ; hypertension ; alpha1-adrenergic blockade ; calcium antagonism ; vasodilatation ; plasma noradrenaline
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The hypotensive effect of vasodilator monotherapy in hypertension is attenuated by a baroreceptor-mediated increase in the sympathetic release of noradrenaline. Nifedipine induces a rise in noradrenaline release, but it is not known to affect noradrenaline-induced vascular contraction of smooth muscle to a clinically significant degree. The haemodynamic and hormonal effects of a single sublingual dose of nifedipine 20 mg in 8 moderately hypertensive patients have been studied before and during postsynaptic alpha1-blockade with prazosin. The antihypertensive effect of nifedipine was significantly increased by prazosin pretreatment (fall in mean arterial pressure 60 min after nifedipine: −16.7% with and −8.5% without prazosin), despite similar increases in plasma noradrenaline. Prazosin alone caused no change in supine blood pressure for 2 h after an oral dose of 2 mg. The findings are in keeping with the hypothesis that prazosin blocks a compensatory reaction to vasodilatation caused by nifedipine.
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  • 50
    ISSN: 1432-1041
    Schlagwort(e): piretanide ; hypertension ; hydrochlorothiazide/amiloride ; serum potassium
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary In a randomised double blind study in patients with mild to moderate hypertension, piretanide 6 mg once and twice daily significantly reduced both supine and erect blood pressure. This was seen after only 2 weeks and a further progressive reduction was evident over the ensuing 12-week trial period. The higher dose produced a mean maximal fall of 29% in supine diastolic pressure, compared with 23% after the lower dose; the difference is not significant. Hydrochlorothiazide 50 mg/amiloride 5 mg twice daily (HCT/A) also reduced supine blood pressure significantly after 2 weeks, but the reduction in erect diastolic blood pressure did not achieve statistical significance until 8 weeks. The maximal effect (a 13% fall in supine diastolic blood pressure) was significantly less than that of either piretanide regimen. Blood pressures in this group also returned more rapidly to pretreatment levels during the placebo washout phase at the end of the study. HCT/A produced a significant sustained rise in serum potassium and a reduction in serum sodium and chloride. Piretanide had minimal effects on serum electrolytes.
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  • 51
    ISSN: 1432-1041
    Schlagwort(e): hypertension ; acebutolol ; hydrochlorothiazide ; elderly ; cross-over trial ; blood pressure reduction
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary To evaluate the efficacy of acebutolol, 400–600 mg/day in elderly hypertensive patients, and to compare it with hydrochlorothiazide 25–50 mg/day, 45 patients with mild-moderate uncomplicated hypertension were treated for 6 weeks in a multicentre, single-blind, randomized, crossover trial. Acebutolol decreased supine systolic blood pressure from 186.5 to 162.7 mmHg and diastolic blood pressure from 107.4 to 92.4 mmHg. Hydrochlorothiazide decreased systolic blood pressure from 185.0 to 166.4 and diastolic blood pressure from 107.2 to 96.4. There was no difference between the effects of acebutolol and hydrochlorothiazide on blood pressure during the trial. Both drugs proved to be safe and effective antihypertensive agents, provided the major contraindications for their use were taken into account. Beta-blockade by acebutolol was highly effective in treating mild-moderate arterial hypertension in the elderly.
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  • 52
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 29 (1985), S. 281-285 
    ISSN: 1432-1041
    Schlagwort(e): bopindolol ; metoprolol ; blood pressure ; heart rate ; effect duration ; hypertension ; side-effects
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary 14 male hypertensive patients, mean age 53 years first took part in a 3 month, double-blind crossover comparison of 1–2 mg bopindolol, a nonselective β-blocker with ISA, and 100–200 mg metoprolol. Effects on blood pressure and heart rate were followed. One patient dropped out after the initial phase and the remaining 13 patients were followed for 1 year on bopindolol. 8 patients measured blood pressure at home, and in them bopindolol 1 mg o.d. and 8 mg once weekly were compared in a double-blind fashion, for 3 weeks on each regimen. Finally, after 1 year on bopindolol, treatment was withdrawn and blood pressure and heart rate were followed in 10 of the initial patients. Bopindolol in a mean doese of 1.35 mg/day caused a significant reduction in blood in pressure (26/15 mmHg), as did metoprolol (24/13 mmHg) in a mean dose of 144 mg/day. No significant difference in antihypertensive response was observed. Supine and standing heart rate were reduced both during bopindolol and metoprolol treatment. During long-term therapy with bopindolol, satisfactory blood pressure control was maintained up to 1 year in all patients, the average supine blood pressure being reduced from 173/107 to 144/90 mmHg. During treatment with bopindolol 8 mg once weekly, the blood pressure control was satisfactorily maintained over the week and no significant difference was observed in comparison with daily administration (1 mg) of the drug. When active treatment was withdrawn, a gradual increase in blood pressure and heart rate was observed, the pretreatment values being reached 8 weeks after discontinuation of bopindolol therapy. Thus, effective blood pressure control was achieved with bopindolol in patients with mild hypertension. The effect was sustained over 12 months and tolerance was good. The relatively long half-life of the drug made it possible to use it in once weekly regimen.
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  • 53
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 29 (1985), S. 391-393 
    ISSN: 1432-1041
    Schlagwort(e): diabetes mellitus ; hypertension ; guanfacine ; glucose tolerance ; insulin ; side-effects ; coronary risk
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary In the present study the effect of 1 year of antihypertensive treatment with guanfacine (g) has been evaluated in 18 hypertensive patients with adult-onset, non-insulin-dependent diabetes mellitus (WHO Type II). The treatment produced a marked improvement in the oral glucose tolerance test; guanfacine significantly decreased serum glucose levels, and affected only slightly the insulin secretion. It is suggested that the effect of g may be mediated via a reduction in catecholamine and/or growth hormone and ACTH secretion. The present results also suggest that treatment with guanfacine may improve individual coronary risk in hypertensive diabetic patients.
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  • 54
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 28 (1985), S. 135-138 
    ISSN: 1432-1041
    Schlagwort(e): hypertension ; cadralazine ; vasodilators ; chlorthalidone ; atenolol ; side-effects
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The antihypertensive efficacy of a new long-lasting vasodilator, cadralazine, and the diuretic chlorthalidone have been compared in hypertensive patients receiving concurrent treatment with atenolol. After a 4-week run-in period with atenolol alone 100 mg/day, two groups of 10 patients whose diastolic blood pressure exceeded 100 mm Hg were given for a period of 65 days either cadralazine 15 mg/day or chlorthalidone 25 mg/day, according to a randomized, double-blind, between-patients design. Compared to atenolol alone, both cadralazine and chlorthalidone induced a statistically and clinically significant decrease in blood pressure. The antihypertensive effect did not differ significantly between groups. Good compensation of the atenolol-induced decrease in heart rate was obtained with cadralazine, whereas during atenolol + chlorthalidone treatment at times the standing heart rate was significantly lower than during treatment with atenolol + cadralazine. Side-effects, many of which were already present during atenolol treatment, occurred with a similar frequency in both groups. It is concluded that atenolol + cadralazine and atenolol + chlorthalidone are equally well tolerated, acceptable and effective in the treatment of hypertension, but that further studies are warranted to explore the potential haemodynamic advantages of the cadralazine + atenolol combination.
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  • 55
    ISSN: 1432-1041
    Schlagwort(e): hypertension ; cardiac hypertrophy ; echocardiography ; therapeutic regimes ; beta-receptor blockade ; hydralazine ; methyl-dopa
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary Forty-three patients with essential hypertension were randomly allocated to one of the following treatment regimes; — atenolol, atenolol and hydralazine or methyl dopa. Blood pressure fell into the normal range at 3 months and was similar in all 3 groups. Blood pressure remained controlled over the period of study. M-mode echocardiography was assessed initially, at 3, 6 and 12 months. All groups showed a fall in the measured indices towards the normal range with a significant reduction in left ventricular wall thickness at 3 months in the methyl dopa group and left ventricular mass in the atenolol group alone of 6 months. In conclusion, no one treatment regime appeared to have sustained advantages over another and none of the groups showed any deterioration on echocardiographic criteria during the study.
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  • 56
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 28 (1985), S. 347-349 
    ISSN: 1432-1041
    Schlagwort(e): pinacidil ; hypertension ; vasodilation ; side-effects
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary Twenty three patients with essential hypertension who were uncontrolled on diuretic and/or β-receptor antagonist therapy were treated additionally with the vasodilator, pinacidil, in an open study. Significant reduction in mean blood pressure was achieved. Supine and erect systolic and diastolic blood pressure fell by 44/25 mmHg and 37/24 mmHg respectively over the study period of 12 weeks. Side-effects such as dizziness, headache, facial flushing and mild oedema were experienced by 10 patients during the study, all of which were mild and transient and did not require withdrawal from pinacidil therapy. Pinacidil is an effective and well tolerated agent in the treatment of essential hypertension.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 57
    ISSN: 1432-1041
    Schlagwort(e): acebutolol ; hypertension ; antinuclear antibody ; practolol syndrome ; ocular examination
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary Twenty patients with essential hypertension were given 400 mg acebutolol once daily for 24 weeks. In order to study if side effects resembling the “Practolol syndrome” developed, ocular effects were sought and antinuclear antibody (ANA) in blood was assessed before and after treatment. ANA was negative both before and after the study in 17 patients; in one patient ANA was positive, but the titre (1:10) was low and did not change during the study. Acebutolol produced no undesirable effects on cornea, conjunctiva or lens. During acebutolol treatment, tear secretion was reduced but tear lysozyme concentration was not significantly altered. Overall, acebutolol had no undesirable action similar to the practolol-induced syndrome, nor did it cause such common clinical ocular symptoms such as dry or gritty eyes.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 58
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 28 (1985), S. 35-39 
    ISSN: 1432-1041
    Schlagwort(e): urapidil ; clonidine ; hypertension ; side-effects ; hypotensive effect
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Summary The antihypertensive effects of urapidil and clonidine have been studied in a double-blind cross-over trial in 11 hypertensive outpatients with mild to moderate hypertension, at rest and during isometric exercise. Urapidil 30 mg b.i.d. significantly decreased the standing diastolic blood pressure (p〈0.05) and the systolic blood pressure at the end of isometric exercise (p〈0.05). Clonidine 0.075–0.15 mg b.i.d. was more effective in decreasing both systolic and diastolic blood pressure in the supine and standing positions as well as during isometric work (p〈0.05–0.001). Urapidil caused fewer side-effects than clonidine. Overall, in the doses used urapidil had a weaker antihypertensive effect and caused fewer side-effects than clonidine.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 59
    Digitale Medien
    Digitale Medien
    Springer
    Acta applicandae mathematicae 4 (1985), S. 225-258 
    ISSN: 1572-9036
    Schlagwort(e): 92A15 ; Prey ; predator ; competition ; dynamical system ; ordinary differential equation ; phase diagram ; equilibrium ; trajectory ; stability ; bifurcation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Abstract We consider a problem of the dynamics of prey-predator populations suggested by the content of a letter of the biologist Umberto D'Ancona to Vito Volterra. The main feature of the problem is the special type of competition between predators of the same species as well as of different species. Two classes of cases are investigated: a first class in which the behaviour of the predator is ‘blind’ and the second one in which the behaviour is ‘intelligent’. A qualitative analysis of the dynamical systems under consideration is followed by a numerical analysis of the most significant cases.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 60
    ISSN: 1573-1561
    Schlagwort(e): Choristoneura pinus pinus ; jack pine budworm ; Lepidoptera ; Tortricidae ; (E,Z)-11-tetradecenyl acetate ; (E,Z)-11-tetradecen-1-ol ; sex pheromone ; sex attractant
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Chemical identification and field-trapping experiments have shown that a blend of 85∶15 (E,Z)-11-tetradecenyl acetates and 85∶15 (E,Z)-11-tetradecen-1-ols (in a 9∶1 ratio) are female sex pheromone components for jack pine budworm,Choristoneura pinus pinus. This blend of chemicals, formulated in PVC (0.1 %, w/w) sources is as effective a trap bait as virgin females. Preliminary wind tunnel observations have indicated that this blend, effective as a trap bait, is not equivalent to females.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 61
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 11 (1985), S. 181-189 
    ISSN: 1573-1561
    Schlagwort(e): Chemical detection ; Orconectes virilis ; crayfish ; sex recognition ; stress
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Individual crayfish (Orconectes virilis) were tested for responses to water containing conspecific individuals of several sex-status categories. Isolated males did not react to “self” water but did show aggressive postures while isolated, nonself male water was introduced. Males' responses to female water was different from responses to male water. Water from aggressing males elicited fewer agonistic postures and more “neutral” postures. Females showed little difference in response to waters from different categories of conspecifics.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 62
    ISSN: 1573-1561
    Schlagwort(e): Southern pine coneworm ; Dioryctria amatella (Hulst) ; Lepidoptera ; Pyralidae ; oviposition and feeding preference ; synthetic oviposition stimulant ; slash pine ; Pinus elliottii Engelm. var.elliottii ; monoterpenes ; fusiform rust ; Cronartium quercuum (Berk.) Miy. ex Shirai f. sp.fusiforme
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Bioassays were conducted with first-stage larvae and newly emerged females of the southern pine coneworm,Dioryctria amatella (Hulst), to detect feeding and ovipositional preferences for different host-plant materials collected between April and August. Correlations between measures of insect preferences and estimates of wood parameters indicated that larvae preferred to feed on host-plant materials with high moisture contents, low wood densities, and low monoterpene contents. Female moths, however, did not necessarily select those plant materials preferred by larvae for feeding, but tended to oviposit more frequently on materials with high monoterpene contents. A synthetic mixture of monoterpenes similar in composition to those present in fusiform rust galls of slash pine (Pinus elliottii) Englem. var.elliottii) elicited mating and oviposition behavior.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 63
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 11 (1985), S. 793-800 
    ISSN: 1573-1561
    Schlagwort(e): Trichogramma evanescens ; Hymenoptera ; Trichogrammatidae ; Pieris brassicae ; Pieris rapae ; Lepidoptera ; Pieridae ; kairomone ; oviposition ; deterring pheromone ; accessory gland ; egg parasite ; tricosane
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract In observation-cage experiments some new contact kairomones for the egg parasiteTrichogramma evanescens Westwood are demonstrated.T. evanescens females search significantly longer on cabbage leaves treated with the wing scales of two hosts,Pieris brassicae L. andP. rapae L. Further, egg washes ofP. brassicae containing an oviposition deterrent pheromone for the butterflies, were found to have a contact-kairomonal effect on the parasite.T. evanescens females search significantly longer on cabbage leaves sprayed with a methanol or water wash ofP. brassicae eggs than on leaves treated with the solvent only.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 64
    ISSN: 1573-1561
    Schlagwort(e): Fatty acid analysis ; double-bond location ; dimethyl disulfide adducts ; mass spectrometry ; pheromone ; Choristoneura fumiferana ; C. occidentalis ; C. pinus pinus ; Plusia chalcites ; Lepidoptera ; Tortricidae ; Noctuidae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract A rapid analytical procedure for the determination of the position of double bonds in mixtures of monounsaturated fatty acid methyl esters has been developed. The method is based on direct capillary GC-MS-EI analysis of dimethyl disulfide adducts. The procedure was applied to mixtures of monounsaturated fatty esters from pheromone gland extracts of three tortricids from theChoristoneura genus,C. fumiferana, C. occidentalis, andC. pinus pinus, and one noctuid from the Plusiinae subfamily,Plusia chalcites. A correlation was found between the known major pheromone components in the four species with the corresponding fatty acids. Some of the additional fatty acids may be precursors to as yet unidentified minor pheromone components, present in extremely small quantities, in these species.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 65
    Digitale Medien
    Digitale Medien
    Springer
    Journal of mathematical biology 21 (1985), S. 285-298 
    ISSN: 1432-1416
    Schlagwort(e): Population dynamics ; coexistence ; mutualism ; persistence ; predator-mediated coexistence ; stability
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Mathematik
    Notizen: Abstract We address the question of the long term coexistence of three interacting species whose dynamics are governed by the ordinary differential equations x i = X i f i (i = 1, 2, 3). In order for any theory in this area to be useful in practice, it must utilize as little information as possible concerning the forms of the f i , in view of the great difficulty of determining these experimentally. Here we obtain, under rather general conditions on the equations, a criterion for judging whether the species will coexist in a biologically realistic manner. This criterion depends only on the behaviour near the one or two species equilibria of the two dimensional subsystems, the behaviour there being relatively easy to examine experimentally. We show that with the exception of one class of cases, which is a generalization of a classical example of May and Leonard [21], invasibility at each such equilibrium suitably interpreted is both necessary and sufficient for a strong form of coexistence to hold. In the exceptional case, a single additional condition at the equilibria is enough to ensure coexistence.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 66
    Digitale Medien
    Digitale Medien
    Springer
    Journal of mathematical biology 22 (1985), S. 81-104 
    ISSN: 1432-1416
    Schlagwort(e): FitzHugh-Nagumo equation ; pulse solution ; stability
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Mathematik
    Notizen: Abstract The FitzHugh-Nagumo equation u t =u xx +f(u)-w, u t =b(u-dw), is a simplified mathematical description of a nerve axon. If the parameters b〉0 and d⩾0 are taken suitably, this equation has two travelling pulse solutions with different propagation speeds. We study the stability of the fast pulse solution when b〉0 is sufficiently small. It is proved analytically by eigenvalue analysis that the fast pulse solution is “exponentially stable” if d〉0, and is “marginally stable” but not exponentially stable if d=0.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 67
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 239 (1985), S. 3-8 
    ISSN: 1432-0878
    Schlagwort(e): GnRH receptors ; Gonadotropes ; Coated pits ; Internalization ; High-resolution autoradiography ; LHRH, Gonadoliberin ; Pituitary gland ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Localization of GnRH receptors in rat pituitary gonadotropes was studied by use of 125I-[azidobenzoyl-D-Lys6]GnRH which, upon photolysis, is covalently bound to the receptor molecule. Using high resolution autoradiography, it was found that, after a 90-min incubation of the analog with pituitary cells at 4° C, 93% of the silver grains were associated with the plasma membrane of the gonadotropes. After 45-min incubation of the cells at 37° C, clustering and internalization of the receptor-bound GnRH analog were evident. Silver grains were associated with coated pits, intracellular vesicles, Golgi complexes, lysosome-like structures and secretory granules. The data indicate that receptor-bound GnRH agonist is internalized, at least in part, via coated pits and is subsequently routed to lysosomes where degradation of the hormone-receptor complex may occur. The presence of a considerable amount of silver grains associated with secretory granules may suggest that some of the internalized receptor molecules can escape degradation and be recycled to the cell membrane.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 68
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 239 (1985), S. 31-35 
    ISSN: 1432-0878
    Schlagwort(e): Lymph filtration ; Antigen and antibody distribution ; Subcapsular sinus ; Lymph node ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary A recent study of lymph nodes of the rat showed that they are morphologically and physiologically compartmentalized. A compartment of a node includes a portion of subcapsular sinus into which the lymph, entering via the related afferent lymphatic opening, is filtered. The study also showed that colloidal carbon injected locally in a small dose becomes predominantly associated with the areas of the inner wall of the subcapsular sinus that cover the extrafollicular zone of the peripheral cortex. Little carbon is seen over the folliculo-nodules (follicles with a nodule or germinal center). The question arose as to whether drained natural substances, as antigens and antibodies, follow the same pattern of distribution in the subcapsular sinus as the carbon. Therefore, small doses of fluorescein isothyocyanate (FITC)-conjugated antigens were injected locally into normal rats whose own antibodies in the nodes were stained by immunofluorescence. The pattern of distribution of the antigens in the draining nodes was found to be the same as that of the carbon. Furthermore, the lymph-carried antibodies of the rats were found to follow the same pattern. The morphological basis for such a pattern is explained. The results are further discussed with regard to the probable normal entry route of lymph-carried antigens in the parenchyma of nodes.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 69
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 239 (1985), S. 137-140 
    ISSN: 1432-0878
    Schlagwort(e): Lanthanum ; Odontoblasts ; Tight junctions ; Tooth pulp ; Ultrastructure ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Odontoblasts are known to be involved in the process of dentinogenesis but it is not clear whether substances may also be deposited in predentine and dentine by passing between these cells. Although tight junctions have been described, it is not clear if they are macular or “leaky” as opposed to continuous or “tight”. In this study use has been made of the permeability of fenestrated capillaries amongst the odontoblasts to deposit the penetrative tracer lanthanum in the interodontoblastic space. This was done by perfusion of anaesthetized rats with physiological solutions containing lanthanum nitrate at 37° C. Immersion fixation of transverse segments of mandibular incisors and examination with an electron microscope showed that lanthanum could permeate 40–50 μm between the odontoblasts to reach the peripheral pulp. Towards the predentine, often less than 10 μm from the capillaries, its progress was abruptly and completely halted by the junctions at the apical ends of the odontoblast cell bodies. Lanthanum was not found in the predentine. The mature secretory odontoblasts in the rat incisor have therefore been shown to be joined by continuous tight junctions. In the process of dentinogenesis this means that all substances deposited in predentine and dentine must arrive by passing through the odontoblasts.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 70
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 239 (1985), S. 183-188 
    ISSN: 1432-0878
    Schlagwort(e): Fenestrations ; Basal lamina ; Intestine, small ; Immune system ; SEM ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Fenestrations of the basal lamina of rat intestinal villi were revealed by scanning electron microscopy after removal of the overlying epithelial cells by osmic acid maceration. These fenestrations are circular to oval in shape and are 0.5 μm to 5 μm in diameter. They are richly distributed at a density of 1–2x104/mm2 in the upper two thirds of the villi, except at the very tips. Roughly 500 fenestrations are found on each side of an average sized tongue-shaped villus. Transmission electron-microscopic observations showed that these fenestrations were passages for migrating cells of the immune system such as lymphocytes, eosinophils and macrophages. Protrusions from the basal parts of epithelial cells were also observed passing through these fenestrations. These findings are discussed with respect to their immunological implications and to the passage of nutrients.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 71
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 239 (1985), S. 293-298 
    ISSN: 1432-0878
    Schlagwort(e): Acid phosphatase cytochemistry ; Lysosomes ; Synovial membrane ; Synoviocytes ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The lysosomal system of the two types of synoviocytes (A and S) from the knee joint of normal rat synovial membrane was studied by electron-microscopic acid phosphatase cytochemistry. In random sections of the synovial intima lysosomes were more often encountered in the A-cell profiles than in the S-cell profiles. Characteristically, type-A synoviocytes showed many large and medium-sized lysosomes the cytochemical appearance of which varied considerably. No acid phosphatase activity was detectable in the cisternae of the Golgi apparatus or in the Golgi vesicles. In type-S synoviocytes the lysosomes were smaller, and more uniform in cytochemical appearance. Heavy deposits of acid phosphatase reaction product were constantly demonstrated in cisternae of the Golgi apparatus as well as in smooth-walled Golgi vesicles in type-S cells. The findings that type-A and type-S synoviocytes show distinctly different organization of the lysosomal system indicate that the roles of the lysosomes in these two types of cells may be different.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 72
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 239 (1985), S. 651-655 
    ISSN: 1432-0878
    Schlagwort(e): Gap junctions ; cAMP ; Liver ; Freeze-fracturing ; Morphometry ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Since cAMP has recently been reported to be a possible physiological modulator of cell-to-cell communication, we performed a quantitative freeze-fracture investigation on the hepatocyte gap junctions after administration of a membrane-permeant derivative of this cyclic nucleotide. For this purpose, male rats received two intraperitoneal injections of 100 mg dibutyryl cAMP/kg body weight with a time interval of 2.5 h. Litter mates were injected with saline only. Five hours after the start of the treatment, tissue blocks of the left lateral liver lobe were fixed by immersion and processed for freeze-fracture. By point counting on negatives projected on a square double-lattice test system the relative gap junctional area on contiguous hepatocyte membranes was determined. As compared to control animals, the proportion of the membrane area occupied by gap junctions in dibutyryl cAMP-treated liver parenchyma significantly increased from 4.9% to 6.1%. Within the gap junctions no changes in shape, particle density or packing pattern were observed. Possibly, the enlarged gap junctional area provides structural pathways for the integration of the response of hepatocytes to messages mediated by cAMP.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 73
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 239 (1985), S. 131-136 
    ISSN: 1432-0878
    Schlagwort(e): Capillary permeability ; Lanthanum ; Peripheral nerves ; Tooth pulp ; Ultrastructure ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Experiments were performed to compare the permeability of capillaries supplying the endoneurial environment, which is invested by perineurium, with vascular permeability in the pulp where perineurium is absent. Anaesthetised rats were perfused through the aorta with physiological solutions containing lanthanum nitrate at 37° C. Pieces of inferior alveolar nerve and segments of mandibular incisors were immersion-fixed and transverse sections were examined electron microscopically for the distribution of lanthanum. In the pulp the nerve fibres pass between lanthanum-impermeable arterioles and venules en route to the incisal end. In the peripheral pulp a few capillaries were permeable but the most permeable capillaries lay between the odontoblasts. Pulpal capillary permeability was attributed to the fenestrated endothelium and contrasted with the unfenestrated endoneurial capillaries which were impermeable to lanthanum. Whereas the tight junctions of endoneurial capillaries are known to prevent certain blood-borne substances from entering the endoneurium, it was not clear whether the permeability of the pulpal capillaries, which are distant from the nerve fibres, could affect the nerve fibre environment. No extravasated lanthanum reached the pulpal nerve fibres suggesting that they are not affected. Technically it was not possible to examine the incisal third of the tooth where the situation could be different because the volume of the pulp decreases and capillaries lie closer to the nerve fibres.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 74
    ISSN: 1432-0878
    Schlagwort(e): Neuropeptides ; Autonomic denervation ; Neuropeptide Y ; Vasoactive intestinal polypeptide (VIP) ; Substance P ; Urinary bladder ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The origin and distribution in the urinary bladder of nerve fibers containing neuropeptide Y (NPY), vasoactive intestinal polypeptide (VIP) and substance P (SP) were investigated in rats. Experimental procedures comprised preganglionic decentralization or postganglionic denervation of the bladder and also chemical sympathectomy as well as capsaicin treatment of newborn rats. Nerve fibers containing NPY were richly distributed in the detrusor muscle and also in the pelvic ganglia. Numerous NPY-containing nerve cell bodies were found in pelvic ganglia. A rich occurrence of VIP fibers and a more sparse distribution of SP-containing fibers were also found in the bladder as well as a relatively rich representation of VIP- containing nerve cell bodies in the pelvic ganglia. After decentralization the intensity of VIP and NPY immunofluorescence increased in nerve cell bodies of the pelvic ganglia and in nerve fibers in the wall of the bladder. Postganglionic denervation, on the other hand, eliminated all peptides examined in the bladder wall. After postganglionic denervation the situation in the ganglia was approximately the same as after decentralization. Chemical sympathectomy (6-OHDA) did not seem to change significantly the frequency and distribution of VIP-, SP- and NPY-fibers in the muscle layer of the bladder or in the pelvic ganglia, while the NPY-containing nerve fibers in the submucosal layer and around blood vessels of the bladder disappeared. Adrenergic nerve fibers in the wall of the bladder (visualized by histofluorescence) were markedly reduced in number after administration of 6-OHDA. Capsaicin-treatment of newborn rats caused a loss of SP-fibers in the wall of the bladder, supporting the view that these fibers are sensory in nature in the urinary bladder. Although it cannot be entirely excluded that NPY-containing fibers in the wall of the bladder are adrenergic, the present results suggest that the NPY-fibers as well as the VIP-fibers of the bladder wall originate mainly in non-adrenergic cell bodies of the pelvic ganglia. However, perivascular NPY-containing nerve fibers are adrenergic in nature.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 75
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 239 (1985), S. 177-182 
    ISSN: 1432-0878
    Schlagwort(e): Lymphoid tissue ; Lung ; Bronchi ; Immuno-histochemistry ; Enzyme histochemistry ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Immunohistochemical, enzyme-histochemical and electron-microscopical methods were used to study non-lymphoid cells of control and stimulated rat bronchus associated lymphoid tissue (BALT) in situ and in suspensions. Particular attention was paid to the so-called antigenhandling cells, i.e., the interdigitating cells (IDC), which are situated in the T-cell areas, the follicular dendritic cells (FDC), which appear to be restricted to germinal centers, and macrophages, present both in T-cell and B-cell areas. The interdigitating cells were distinguished by being Ia-positive and by the presence of acid phosphatase and non-specific esterase activity in an area near the nucleus. Follicular dendritic cells could be observed in situ by using a monoclonal antibody and by the in vitro trapping of HRP-anti-HRP complexes. Several types of macrophages were found. At the electron-microscopical level no well-developed IDC and FDC could be detected in control BALT. However, in BALT of lipopolysaccharide-stimulated and mycoplasma-infected rats, well-developed IDC and FDC were found. It can be concluded that IDC's and FDC's can be found in BALT.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 76
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 239 (1985), S. 405-415 
    ISSN: 1432-0878
    Schlagwort(e): Testis ; Leydig cell ; FSH ; Morphometry ; Ultrastructure ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The effects of FSH on the testicular interstitial tissue of immature hypophysectomized rats were studied by comparing morphological changes in Leydig cells with quantitative changes in interstitial tissue histology using morphometric analysis. Three groups of rats received subcutaneous injections of 0.5 ml saline vehicle or 10 μg rFSH or 20 ng oLH (equivalent to the amount of LH known to contaminate the FSH), twice daily for 7 days. Administration of FSH significantly increased testis weight and stimulated more advanced spermatogenesis compared to saline or LH. Morphometric analysis of testes of LH-treated rats showed a small but significant increase in total interstitial cell volume compared to saline treatment. FSH caused much greater increases in the total volume of interstitial tissue and interstitial cells than either saline or LH and significantly increased the total volume of interstitial fluid by comparison with the other groups. FSH but not saline or LH treatment resulted in a striking hypertrophy of Leydig cells, to produce cells ultrastructurally identical to Leydig cells from adults. Since the target tissue of FSH is the seminiferous epithelium, the observed effects on Leydig cells by FSH treatment suggest that the secretion of factors by the seminiferous tubules may mediate the maturation of Leydig cells.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 77
    ISSN: 1432-0878
    Schlagwort(e): Trachea ; Basal lamina ; Anchoring fibril ; Ruthenium red-positive filaments ; New anchoring device ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The structural relationship between the basal lamina and the underlying reticular tissue was studied, with special attention to the relationship among basal lamina-associated anchoring fibrillar (AF) arcs (Kawanami et al. 1978, 1979) and other fibrillar components, in the epithelium-denuded trachea of the rat. Quantitative analysis of a large number of AF arcs reveals that the majority of the AF arcs has no other fibrillar components of passage. This suggests that most AF arcs do not serve as a real anchoring device, connecting the basal lamina with the underlying reticular tissue, as has so far been suggested by Kawanami et al. (1978). Ruthenium-red staining reveals the presence of a unique meshwork of microthread-like filaments connecting the undersurface of the basal lamina or the AF arcs with the underlying fibrillar components with a remarkable continuity, suggesting that the filaments act as a real anchoring device; these filaments link, instead of the AF arcs, the basal lamina, to the subjacent reticular tissue. Various enzymatic treatments of the filaments indicate that their chemical nature is probably non-collagenous (glyco)protein without glycosaminoglycan moieties.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 78
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 239 (1985), S. 37-42 
    ISSN: 1432-0878
    Schlagwort(e): Subcapsular sinus ; Subsinus layer ; Peripheral cortex ; Lymph node ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The peripheral cortex of a lymph node consists of folliculo-nodules (follicles with a nodule or germinal center) and an extrafollicular zone. In the course of an analysis of the nodes in rats under various experimental or abnormal conditions, our attention became focused on the particularities of a thin layer of peripheral cortex underlying the subcapsular sinus. The present paper reports on observations which led to the identification of the “subsinus layer” of the peripheral cortex. The observations suggest that this layer complements the activity of the inner wall of the subcapsular sinus. The layer probably contributes to the selection of certain elements from the afferent lymph and guides them towards the node area where they can join the cell population involved in the immunological activity in which they are to participate.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 79
    ISSN: 1432-0878
    Schlagwort(e): Pancreatic acini ; Secretion ; Amylase ; Secretagogues ; Receptors ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Incubation of rat pancreatic lobules for 90 min with optimal concentrations of caerulein, carbachol or secretin caused the release of about 30% of the amylase content. Combination of secretin with carbachol or caerulein increased the amylase output to about 40%. With secretin, as with carbachol or caerulein, heterogeneity of cellular responsiveness was observed, some acini being partially or completely depleted of their zymogen granules, whereas others appeared to be resting. When secretin was combined with carbachol or caerulein, granule depletion, originally confined to small groups of neighbouring acini, spread to form large areas of degranulated cells, sometimes comprising a whole section of a lobule. In dispersed acini, under the same conditions, carbachol caused the release of about 60% of the amylase content, and secretin 40%. When both secretagogues were combined, a significant increase to 78% was observed. Under these conditions, there was some important cellular damage, as indicated by the release of 20% of the amylase content and between 6 and 12% of lactate dehydrogenase into the media, in the absence of stimulus. These results were corroborated by cytological observations. On the basis of their secretory response two groups of acini can be distinguished, those that respond to carbachol, caerulein or secretin and those that respond to the combination of secretin with carbachol or caerulein. Electrophoretic patterns of secretory proteins released by lobules stimulated by these different types of secretagogues were essentially similar. The pattern was quite different, however, in the absence of a stimulus. The most striking feature was the presence of a band at 63 Kd whereas a 73.5 Kd band was found only under conditions of stimulation. The latter results support the view that under resting and stimulated conditions secretory proteins are released from distinct compartments in the acinar cell.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 80
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 239 (1985), S. 229-233 
    ISSN: 1432-0878
    Schlagwort(e): Chemotherapy ; Vincristine ; Constipation ; Mucosa ; Regulatory peptides ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The microtubule-disrupting drug vincristine is a common component of anti-cancer chemotherapeutic regimes, which produces acute constipation as a side effect. Although generally attributed to damage to the myenteric plexus, the precise mechanism of this disturbance is unknown. In addition, vincristine causes marked aberrations in the secretory response of pancreatic endocrine tissue in both man and rats. No information is available on its possible effect on regulatory peptides of the gastrointestinal tract. In this study we have produced vincristine-induced constipation in rats at a dosage comparable with that employed in the treatment of human subjects. Immunocytochemistry revealed concomitant disturbances in cells exhibiting immunoreactivity for gastrin in the antrum, for gastric inhibitory polypeptide and 5-hydroxytryptamine in the duodenum, for enteroglucagon in the colon, and for somatostatin in all three sites. These widespread effects are transient in nature with normal cell numbers and morphology being reestablished within 6 days. It is suggested that the observed effects are a direct result of microtubule disruption and that gastrointestinal regulatory peptide and amine immunoreactive cells have a rapid regeneration potential.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 81
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 239 (1985), S. 235-239 
    ISSN: 1432-0878
    Schlagwort(e): Erythropoiesis ; Autophagy ; Mitochondria ; Electron microscopy ; Stereology ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Late erythroblasts and reticulocytes from bone marrow of male Wistar rats were studied by electron-microscopic stereology. Late erythroblasts with morphological signs of nuclear extrusion (EN+erythroblasts) and late erythroblasts without these signs (EN-erythroblasts) were analysed separately. The volumes of mitochondria, autophagosomes, autophagocytosed mitochondria, autophagocytosed cytoplasm and degraded material inside autophagosomes were calculated per unit volume of cytoplasm. The results demonstrate that (1) the volume density of mitochondria in the cytoplasm decreases by 34% during maturation from (EN-)- to (EN+)-erythroblasts (p〈 0.001) and by 60% during differentiation from (EN+)-erythroblasts to reticulocytes (p〈0.001), (2) a fivefold increase in the volume density of autophagosomes in the cytoplasm is noted during maturation from (EN-)- to (EN+)-erythroblasts (p〈0.01), whereas the value of this parameter remains essentially unchanged during the subsequent differentiation to reticulocytes, (3) no mitochondria are found inside autophagosomes of (EN-)-erythroblasts, whereas mitochondria occupy 26% and 35%, respectively, of the autophagosomal volume in (EN+)-erythroblasts and in reticulocytes. Our results show that autophagocytosis of mitochondria starts at the moment of nuclear extrusion and continues in the bone marrow reticulocytes.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 82
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 239 (1985), S. 547-553 
    ISSN: 1432-0878
    Schlagwort(e): Endochondral bone development ; Osteoblast ; Osteoclast ; Horseradish peroxidase ; Electron microscopy ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary To investigate the mechanisms whereby bone cells absorb organic bone-matrix components during endochondral bone development, rat humeri were examined, employing horseradish peroxidase as a soluble protein tracer. Intravenously-injected peroxidase filled the osteoid layer and penetrated into the osteocyte lacunae and canaliculi, but did not enter the mineralized bone matrix. Whereas osteocytes rarely took up exogenous peroxidase, osteoblasts and osteoclasts actively endocytosed peroxidase in pinocytotic coated vesicles, tubular structures, and vacuoles. They also formed endocytotic vacuoles containing peroxidase in the Golgi area. The Golgi apparatus and dense bodies of these bone cells were, however, free of reaction products. Osteoclast ruffled borders were responsible for peroxidase absorption. In the osteoblast, osteocyte and osteoclast, endogenous peroxidatic reaction was detected only in mitochondria and not in other membrane-bounded vesicles and bodies. These results strongly suggest that both osteoblasts and osteoclasts participate in the resorption of bone-matrix organic components during bone remodelling.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 83
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 239 (1985), S. 627-631 
    ISSN: 1432-0878
    Schlagwort(e): Thyroidectomy ; Cerebellum ; Coated pit ; Mossy fiber terminal ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The influence that thyroid hormones have on the development of the cerebellar cortex is well known. Their absence in adults leads to important functional changes probably related to abnormalities in nerve terminal activity, although no morphological alterations have hitherto been described. Using ultrastructural morphometric methods, we have studied the effects of thyroidectomy on the cerebellar cortex mossy fiber terminals of adult rats with different survival periods. No significant changes in the volume and surface area of these terminals were found. The numbers of synaptic vesicles in groups 7, 15 and 30 days after thyroidectomy were significantly greater than in controls. A significant increase in coated pit formation was found when thyroidectomized groups were compared with controls. This increase is due to the lack of thyroxin since it can be counteracted by thyroxin administration. Whether this increased coated pit formation is a membrane retrieval mechanism or is related to the uptake of extracellular molecules remains to be determined.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 84
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 240 (1985), S. 215-221 
    ISSN: 1432-0878
    Schlagwort(e): Larval midgut ; Lepidoptera ; 20-Hydroxyecdysone ; Autophagy ; Protein synthesis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary We observed three types of cells in the epithelial layer of the midgut of last instars of Pieris brassicae. The columnar and goblet cells degenerate during the second part of the last larval stage while the undifferentiated basal cells proliferate during this period and create the epithelium of the pupal midgut. The first morphological sign of involution is the formation of autophagic vacuoles and dense bodies in the cytoplasm of columnar and goblet cells which begins on day 4 of the stage. The number and size of autophagic vacuoles and dense bodies increase during the spinning period (85–96 h). Finally, at the end of the stage, the columnar and goblet cells become displaced by the growing pupal epithelium and reach the lumen where they disintegrate. Autophagocytosis was not seen in the cells during the feeding period (0–72 h). However, we observed many autophagic vacuoles in the columnar and goblet cells of 50-h-old instars 3 h after the administration of 30 μg/g body weight of 20-hydroxyecdysone. The hormone treatment elevated by 100% the incorporation of 3H-leucine into the proteins of the midgut. Inhibitors of protein synthesis, cycloheximide and puromycin, in doses that supressed the incorporation of the amino acid by 60–70% either in hormone treated or untreated larvae, exerted diverse effects on the autophagic process. Puromycin did not block the hormone-induced formation of autophagic vacuoles while cycloheximide prevented it. Possible explanations for this diversity are discussed.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 85
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 240 (1985), S. 247-249 
    ISSN: 1432-0878
    Schlagwort(e): Heart ; Mitochondria ; Perfusion ; Ultrastructure ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Mitochondria isolated from heart tissue after a 1-min perfusion with Hanks medium were found to have significantly lower rates of State-3 respiration and respiratory control ratios compared to mitochondria isolated from non-perfused hearts. Examination of the mitochondrial preparations by electron microscopy revealed that a large proportion of the mitochondria isolated from perfused heart tissue were swollen and broken compared to mitochondria from non-perfused hearts.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 86
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 240 (1985), S. 417-423 
    ISSN: 1432-0878
    Schlagwort(e): Cysteine protease ; Epidermal cells ; Antigen localization ; Cell differentiation ; Antigen distribution ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Monospecific antibody directed to cysteine protease of 2-day-old rat epidermis recently characterized as being different from the proteases previously reported was produced in rabbits. By immunofluorescence microscopy and immunoperoxidase staining with an avidin-biotin-peroxidase method the protease was found to be present in the epidermis of rodents of different ages as well as that of humans, but not in the dermis. The staining in germinative cells was more intense than in cells in the superficial layers. It appeared as irregular patches in the nuclei and stained more diffusely in the cytoplasm where small granular components, strongly stained, were identified. The staining patterns in granular cells showed accumulation of the antigen in a granular form. The morphology and distribution of granules resembled those of keratohyalin-like granules in the nucleus and dense homogenous deposits in the cytoplasm. In cornified cells the reaction product was localized by the plasma membrane where concentration of the dense homogenous deposits occurred, suggesting that the cysteine protease is one component of the unique and characteristic structure of differentiated keratinocytes. In addition, the cysteine protease antigen having the same molecular weight as the epidermal enzyme was detected in liver, kidney and lung indicating a wider tissue distribution of the protease. The significance of the protease in regulation of cellular functions remains to be investigated.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 87
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 241 (1985), S. 1-8 
    ISSN: 1432-0878
    Schlagwort(e): Pituitary gland, pars intermedia ; Reserpine ; Secretory granules ; α-MSH ; β-Endorphin ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Reserpine has a stimulatory effect on the pars intermedia of the rat pituitary, probably mediated by its action on regulatory catecholaminergic nerves. The effect of single intraperitoneal injections of 0.1–20 mg/kg b.w. of reserpine was studied in adult male rats. Reserpine at a dose of 2 mg/kg b.w. induced degranulation, orientation of the secretory granules along the cell membrane and loss of formaldehyde-chloral-induced fluorescence, accompanied by an activation of the granular endoplasmic reticulum and the Golgi apparatus. With higher doses progressive degranulation and loss of fluorescence were observed. The effect was, however, heterogeneous, and with all doses cells displaying normal ultrastructure and normal fluorescence were regularly present. To study the release of granular products (containing a different components of the pro-opiomelanocortin chain) from individual cells, formaldehyde-chloral induced fluorescence and α-MSH- and β-endorphin immunoreactivies were demonstrated in consecutive sections from pituitaries of rats given 8 mg/kg body weight of reserpine 24 h before sacrifice. The results indicate coordinated release of these granular products at the cellular level after reserpine treatment.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 88
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 240 (1985), S. 49-55 
    ISSN: 1432-0878
    Schlagwort(e): Lymph node ; Reticular cell ; Mast cell granule ; Fibronectin ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Granules released from mast cells were examined by electron microscopy in regional lymph nodes of rats after the injection of a large dose of horseradish peroxidase (HRP). Thirty minutes after the injection, a large number of mast-cell granules were present in sinuses, most of which adhered to the surfaces of reticular cells and some to macrophages. Two hours after the injection, a number of granules had been taken up by both reticular cells and macrophages. Reticular cells took up more granules than macrophages. Twenty-four hours after the injection, granules were scarce in both types of cells and in the extracellular space. Reticular cells surely participate in dealing with released mast-cell granules in the lymph node. Fibronectin bound to all mastcell granules was demonstrated by immunohistochemistry. Fibronectin probably enables negatively charged mast-cell granules to approach negatively charged cell surfaces to be taken up by both reticular cells and macrophages.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 89
    ISSN: 1432-0878
    Schlagwort(e): Macrophage activation ; Pseudomonas aeruginosa ; X-ray microanalysis ; Elemental analysis ; Electrolytes ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Electron probe X-ray microanalysis (XRMA) of freeze-dried ultrathin sections provides the capability of measuring intracellular elemental content. This methodology was used to investigate the stimulus-permeability coupling responses associated with phagocytosis of Pseudomonas aeruginosa by cultured pulmonary alveolar macrophages (PAMs) of rats. PAMs were challenged with P. aeruginosa suspended in Gey's buffer at a bacteria to PAM ratio of 50∶1 for 1 h at 37° C. A 1-mm3 pellet of the unchallenged control PAMs, challenged PAMs and P. aeruginosa alone was quench-frozen in nitrogen-cooled, liquid propane, and 0.1-μm cryosections were cut at -100° C. X-ray spectra were collected for nucleus and cytoplasm of 39 control PAMs, 36 challenged PAMs and 40 P. aeruginosa. Concentrations (mmole/kg dry weight) were obtained for Na, Cl, K, Ca, Mg, P, S for each cell. In the control PAMs, the content was similar to other mammalian cells. Moreover, there were no differences in elemental content between nucleus and cytoplasm. In the challenged PAMs, Na concentration was 4 times that of control PAMs (p〈0.001) whereas Cl was double (p〈0.001), K was 29% lower (p〈0.001), and Ca was 4 times higher (p〈0.05). The elemental concentration profile in the P. aeruginosa was distinctly different from that of the PAMs: higher Na, Ca, Mg, but lower Cl and K values. These results demonstrate elemental content changes in cultured PAMs challenged with P. aeruginosa that indicate a stimulus-permeability response by membranes associated with the phagocytic process.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 90
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 240 (1985), S. 271-276 
    ISSN: 1432-0878
    Schlagwort(e): Pituitary ; Castration ; Gonadotropes ; Mitosis ; Testosterone replacement ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The proliferation of gonadotropes in the anterior pituitary of the castrated male rat was examined immunohistochemically after colchicine treatment. The results show a more than 10-fold increase in mitotic frequency in gonadotropes 1 or 2 weeks after castration, as compared with controls. This result explains the increase in the population of immunoreactive LH cells in castrated male rats. The gonadotropes decreased significantly 1 month after castration. The mitotic activity of gonadotropes was almost completely suppressed in castrates implanted with a silastic tube filled with testosterone.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 91
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 240 (1985), S. 281-285 
    ISSN: 1432-0878
    Schlagwort(e): Cell dissociation ; Chromaffin cells ; Adrenal medulla ; Tissue transplantation ; Brain grafts ; Rat ; Marmoset monkey
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Adrenal chromaffin cells from adult rats and monkeys were mechanically dissociated and implanted into the striatum of adult rats by stereotaxic injection. Rat chromaffin cells survived (5%) and showed differentiation by forming processes 1 h-28 days after implantation. Monkey chromaffin cells survived for 48 h but showed very little formation of processes. The method presented allows rapid nonenzymatic dissociation and transplantation of adrenal medullary cells.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 92
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 240 (1985), S. 529-534 
    ISSN: 1432-0878
    Schlagwort(e): Collagen fibril ; Freeze-fracture ; Tail tendon ; Rat ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ultrastructure of the collagen of rat tail tendon was investigated by the freeze-fracture technique. Collagen fibers were pretreated with the digestive enzymes, α-amylase, elastase and collagenase to remove matrix substances. Some of the samples were etched for 20 min. Fibrils had an average diameter of 318±12 nm and a banded structure with a mean periodicity of 64.2±0.9 mm; the banding was most marked in α-amylase/elastase-treated specimens, although the periodicity was independent of pretreatment. Microfibrils were well-displayed following α-amylase/elastase and collagenase pretreatments. A difference in the diameters of microfibrils was, however, observed between etched specimens (8.3±0.3 nm) and those prepared by other experimental methods (11.4±0.5 nm). In replicas of collagenase-treated and etched specimens, the interconnecting filaments in the interfibrillar region formed a network that was continuous with the microfibrils of collagen fibrils. The diameter of the interconnecting filaments was the same as that of microfibrils. Microfibrillar bundles were observed in the interfibrillar region.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 93
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 240 (1985), S. 575-584 
    ISSN: 1432-0878
    Schlagwort(e): CRF neurons ; Neurosecretory neurons ; Hypothalamus ; Immunohistochemistry ; Colchicine ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The immunoreactive CRF-neurons of the rat hypothalamus have been examined immunohistochemically employing anti-rat CRF serum. These neurons are confined to the paraventricular nucleus, dorsomedial-lateral hypothalamic area, and suprachiasmatic nucleus, and are, respectively, also immunoreactive to anti-Met-enk, -alpha-MSH, and -VIP sera. Intraventricular administration of colchicine (50 μg/5 μl/rat) induces a dramatic enhancement of the immunostainability of the cell somata, and also accelerates the development of immunoreactivity of other stored peptides, especially in the paraventricular nucleus. The CRF-neurons respond to adrenalectomy by showing increased immunoreactivity and an increase in the number of cell bodies; in the dorsomedial-lateral area and suprachiasmatic nucleus, there is also an enhanced immunoreactivity for alpha-MSH and VIP, respectively. CRF-cells in the paraventricular nucleus become markedly hypertrophied, but do not show any enhanced immunoreactivity for Met-enk. Since the axons of the paraventricular neurons run to the median eminence, it is probable that they are involved with the endocrine control of hypophysial ACTH release. It is concluded that the CRF-containing neurons in rat hypothalamus consist of three types which are functionally and morphologically different.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 94
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 240 (1985), S. 663-667 
    ISSN: 1432-0878
    Schlagwort(e): PRL-like material ; Histoimmunology ; Testis ; Adenohypophysis ; Rat ; Mouse
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Anti-rat prolactin (PRL) antibodies were localized by histoimmunological methods in the cytoplasm of testicular interstitial cells, Sertoli cells, spermatogonia and primary spermatocytes of the rat and mouse. Control of specificity by affinity chromatography methods showed this PRL-like material to be non-specific in these testicular tissues, but specific in adenohypophyseal cells. These results are discussed.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 95
    ISSN: 1432-0878
    Schlagwort(e): Kupffer cells ; Liver endothelial cells ; Cultures ; Surface receptors ; Percoll ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary This paper presents a study on the structure and function of Kupffer cells (KC) and liver endothelial cells (LEC) isolated by a simple and rapid technique involving 1) perfusion of the liver with collagenase; 2) cell separation by means of density centrifugation in Percoll; and 3) cell culture, taking advantage of the fact that KC and LEC differ in their preferences for growth substrate. The KC, which attach and spread under serum-free conditions on surfaces of glass or plastic during the first 15 min in culture exhibit a typical macrophage-like morphology including membrane ruffling and a heterogenous content of vacuoles. Moreover, these cells express (a) Fc receptors (FcR) for binding and phagocytosis of erythrocytes covered with immune globulin G (E-IgG), and (b) complement receptors (CR) for binding and serum dependent phagocytosis of erythrocytes covered with either human C3b or mouse inactivated C3b (iC3b). The cells also bind fluid phase fluoresceinated C3b. Approximately 30% of the KC express immune response-associated (Ia)-antigens. The LEC attach and spread on fibronectin coated surfaces, but not on glass or plastic surfaces, during the first two hours in culture with or without serum, and are morphologically distinct from KC. Cultured LEC are well spread out with no membrane ruffling and with numerous large vesicles surrounding the regularly shaped nucleus. These cells bind, but do not ingest E-IgG via the FcR, but no binding of fluid phase C3b or particle fixed C3b or iC3b can be observed. Incubation of LEC with fluorescein amine conjugates of ovalbumin or formaldehyde treated serum albumin, but not with fluoresceinated native serum albumin, results in accumulation of fluorescence specifically localized in the large perinuclear vesicles. Neither KC nor any other cell types tested have the ability to accumulate fluorescence upon incubation with these compounds. Iaantigens are not present on the LEC. Cytochemical demonstration of unspecific esterase, acid phosphatase, and peroxidase reveals different patterns and intensities of staining in KC as compared to LEC.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 96
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 241 (1985), S. 657-662 
    ISSN: 1432-0878
    Schlagwort(e): Epididymis ; Differentiation ; Organ culture ; Castration ; Ultrastructure ; Morphometry ; Cell types ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The differentiation capacity of the rat epididymis after depletion of androgen was studied in organ culture and in castrated rats. The differentiation of ‘narrow cells’ in 5- and 10-day-old explants and in 10-day-old castrated rats suggests that: (i) the testicular androgens are not essential for their differentiation, (ii) a differential androgen dependence exists among the epididymal cell types, (iii) the undifferentiated epithelial cells are the precursors of the narrow cells.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 97
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 241 (1985), S. 671-675 
    ISSN: 1432-0878
    Schlagwort(e): Collagenase ; Osteoclast ; Bone resorption ; Osteoblast ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The cell-free endocranial surface of young adult rat parietal bones was used as a substrate for bone cell-derived mammalian collagenase. Incubation of parietal bones in a concentration of enzyme comparable to that secreted by osteoblastic cells in vitro caused destruction of surface osteoid, and resulted in exposure of mineral onto the bone surface. Bones so pre-treated were considerably more susceptible to osteoclastic resorption than bones preincubated in the absence of collagenase. These results are consistent with the view that the osteoid layer which covers bone surfaces acts as a barrier to osteoclastic contact with underlying, resorption — stimulating bone mineral; and that cells of the osteoblastic lineage induce osteoclastic resorption through collagenase secretion which, by digestion of the surface osteoid, exposes bone mineral to osteoclastic contact.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 98
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 241 (1985), S. 445-451 
    ISSN: 1432-0878
    Schlagwort(e): Bed nucleus of the stria terminalis (NIST) ; Blood supply ; Double-ink perfusion ; Arteries ; Veins ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The topographical distribution of the blood vessels in the bed nucleus of the stria terminalis (NIST) has been mapped in rats. Arteries and veins were visualized in red and blue by using a double-ink perfusion technique. Arteries supplying the NIST arise from the anterior cerebral artery directly or through the anterior communicating and interhemispheric arteries. Only a few, dorsal branches derive from the medial cerebral artery through thalamostriatal arteries. According to their terminal branches, NIST arteries can be divided into five groups: medial, ventral, lateral, septal and dorsal, which have only a relatively small overlap in their territories. About 90% of veins from the NIST drain into the major basal veins. Medial branches run into the perioptic and interhemispheric veins, while the ventral branches and the large lateral vein drain directly into the anterior cerebral vein. A small proportion of NIST veins run dorsalward into the vena cerebri magna via thalamostriatal veins.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 99
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 241 (1985), S. 459-463 
    ISSN: 1432-0878
    Schlagwort(e): Myocardium ; Regeneration ; Ultrastructure ; Cold injury ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The sequential cytological events in the myocardium of the rat were followed for 3 weeks after cold injury by light and electron microscopy. The traumatized area was initially filled with leukocytes and undifferentiated mononucleated cells and subsequently mainly with fibroblasts surrounded by collagen fibers. However, in the margins of the necrotic area repair processes of damaged myocardial cells and probably also the appearance of newly formed cells were evident. The ultrastructural features of these cells were characterized by clusters of ribosomes, numerous mitochondria that were dispersed in the cytoplasm and formation of junctional complexes and transverse tubular systems. Fibrillogenesis was also clearly evident in these cardiomyocytes. The myofibrillar material was initially dispersed in the cytoplasm and associated with clusters of ribosomes and thereafter with presumptive Z-bands and intercalated discs. The myofibrils became further organized in the shape and orientation of those of mature cells two to three weeks after injury. It is concluded that following cold injury regeneration in the mammalian myocardium takes place but is limited to the perinecrotic area. The process resembles the sequential cytological events which occur in cardiomyocytes during embryonic and postnatal development of the ventricular myocardium.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 100
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 241 (1985), S. 465-472 
    ISSN: 1432-0878
    Schlagwort(e): Striated muscle ; Muscle fiber type ; Schwann cells ; Motor endplate ; Scanning electron microscopy ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The three-dimensional organization of the motor end plates in the red, white and intermediate striated muscle fibers of the rat intercostal muscle was observed under a field-emission type scanning electron microscope after removal of connective tissue components by HCl hydrolysis. The motor endplate of the white fiber had terminal branches (or axon terminals), which were large, long and thin, and small but numerous nerve swellings (or terminal boutons). The motor endplate of the red fiber had terminal branches, which were small, short and thick, and had large but fewer nerve swellings. The motor endplate of the intermediate fiber was intermediate in size and structure between these two. In detached nerve-ending preparations, primary synaptic grooves with slit-like openings of the junctional folds appeared on the surface of the muscle fibers. The primary synaptic grooves were more developed in the white fiber than in the red fiber, and they were intermediate in the intermediate fiber. The numerical ratio of slit-like openings was 1∶1.8∶3.5 in the red, intermediate and white fiber, respectively. The Schwann cells and their processes were observed on the surface of the motor endplate, with the processes covering the upper orifices of the primary synaptic grooves and sealing the terminal branches. The number of Schwann cells was usually three in the white fiber, two in the intermediate fiber and one in the red fiber.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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