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  • 2000-2004  (25)
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  • 201
    Electronic Resource
    Electronic Resource
    The posterior pituitary of the garden dormouse (Eliomys quercinus L.) (1978)
    Springer
    Cell & tissue research 188 (1978), S. 189-204 
    Details
    ISSN: 1432-0878
    Keywords: Neural lobe of hypophysis ; Hibernating mammals ; Ultrastructure ; Neurosecretory granules ; Whorls
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé L'ultrastructure de la posthypophyse du Lérot a été examinée à différents stades du cycle annuel de ce rongeur hibernant. Il n'a pas été observé de différences évidentes entre les stades étudiés, et sont donc présentées ici les caractéristiques générales retrouvées chez tous les animaux. Les axones neurosécréteurs et leurs terminaisons peuvent être divisés en deux catégories suivant l'aspect des grains de neurosécrétat et des microvésicules présents. Le premier type contient des grains arrondis, à contenu d'apparence homogène, avec des microvésicules rondes. Dans les autres axones, les grains sont de forme variable, souvent allongés, et leur contenu présente deux sortes d'organisations cristallines; les microvésicules y sont en majorité aplaties. Considérant comme improbable que cette dualité résulte seulement d'un artefact, trois hypothèses sont envisagées. La dualité d'aspect des grains peut être liée à leur contenu en hormone (ocytocine ou vasopressine); ou bien l'aspect des grains peut correspondre à leur degré de maturation. Il est possible aussi que ces explications soient toutes deux valables. Par ailleurs, les pituicytes du Lérot contiennent fréquemment un réticulum endoplasmique organisé en lamelles concentriques (whorls). La signification de ces formations reste pour l'instant obscure.
    Notes: Summary Ultrastructural examination of the posterior pituitary of the garden dormouse (Eliomys quercinus L.) was carried out at different times in the annual cycle of this hibernating rodent. Obvious differences between experimental groups have not been observed, and the results presented here must be considered as general features of the garden dormouse posterior pituitary. Neurosecretory axons and endings can be divided into two types, according to different aspects of neurosecretory granules (NSG) and microvesicles (MV). One type contains spherical NSG with homogeneous cores and round MV. In the other type, NSG have various, often elongated, shapes. Their content shows two types of crystalline structures and most of the MV have flattened aspects. As it is very unlikely that this duality in NSG is a result of an artefact of fixation, three hypotheses are presented as explanation. The duality of NSG might be related either to their hormonal content (oxytocin or vasopressin) or to their degree of maturation. Moreover, both explanations may be valid. In the species studied, pituicytes often contain concentric lamellar structures of the endoplasmic reticulum (whorls), the significance of which remains obscure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00222630
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  • 202
    Electronic Resource
    Electronic Resource
    Ovarian follicles of normal NMRI mice and homozygous “Nude” mice (1978)
    Springer
    Cell & tissue research 188 (1978), S. 409-426 
    Details
    ISSN: 1432-0878
    Keywords: Ovary ; “Nude” mouse ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ovarian follicles of juvenile (15-day and 21-day old), pubescent (28-day old) and sexually mature (45-day old) “Nude” mice have been compared to those from normal NMRI mice of the same age and breeding groups. At the electron microscopical level, some differences were observed in both follicular cells and oocytes. In the follicular cells, the following alterations could be seen in the “Nude” ovaries: (1) the differentiation between clear and dark cells, normally not occurring before the age of 21 days, was already present in the 15-day old “Nude” mice and (2) the follicular intercellular spaces were frequently dilated, possibly because of a contraction of the cells, even in the small growing follicles of the bilaminar type in the athymic animals. The “Nude” oocytes could be characterized by (1) a precocious appearance and an early disappearance of the nuage material, (2) a nearly complete absence of micropapillae on the oolemma, (3) a dense and disseminated aspect of their Golgi complexes, (4) the presence of a large amount of multivesicular bodies and (5) of tiny (about 30 nm) dense membrane-bounded particles in their ooplasm. These differences are discussed in relation to the possible interference of congenital athymia with the development of the hypothalamo-pituitary-gonadal axis. However, the influence of the reduced immunological responsiveness of the “Nude” mice on their ovarian development cannot be excluded for animals raised in a normal — and consequently infected — environment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219781
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  • 203
    Electronic Resource
    Electronic Resource
    Histological and cytological studies on the fat body of the cockroach Nauphoeta cinerea during the first reproductive cycle (1978)
    Springer
    Cell & tissue research 188 (1978), S. 481-490 
    Details
    ISSN: 1432-0878
    Keywords: Fat body ; Cockroach ; Reproductive cycle ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The central fat body of the ovoviviparous cockroach Nauphoeta cinerea was studied during the first reproductive cycle of the female by means of light microscopy, autoradiography and electron microscopy. Comparative studies in larval stages were also undertaken. The fat body of Nauphoeta contains a large amount of lipid droplets and the remaining cytoplasm is very scarce. The cytological cyclicity of the fat body is consistent with the known biochemical rhythms of vitellogenin production. The proteosynthetic apparatus appears about 3 days after imaginal ecdysis, along with vitellogenin. The ribosomal endoplasmic reticulum (RER) shows a tremendous increase by the 7th day of the first cycle. The most active period of vitellogenin production lasts from day 7 to day 12. The proteosynthetic apparatus then returns to an inactive stage and disappears. This inactive condition lasts to the end of the gestation period. The autoradiographic results are consistent with the cytological features.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219785
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  • 204
    Electronic Resource
    Electronic Resource
    The ultrastructure and function of follicle cells in Foucartia squamulata (Herbst) (Curculionidae) (1978)
    Springer
    Cell & tissue research 189 (1978), S. 347-353 
    Details
    ISSN: 1432-0878
    Keywords: Vitelline membrane ; Chorion ; Ultrastructure ; Curculionidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The follicle cells of Foucartia squamulata are involved in the formation of both vitelline membrane and chorion. Precursors for these egg coverings are synthesized by the rough endoplasmic reticulum and condensed within dictyosomes. The vitelline membrane and the chorion appear on the oocyte surface simultaneously, which is an unusual phenomenon for insects. The follicular epithelium has not been found to contribute to vitellogenesis in the species under study.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00209282
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  • 205
    Electronic Resource
    Electronic Resource
    Oogenesis in Acerentomon gallicum Jonescu (Protura) (1978)
    Springer
    Cell & tissue research 189 (1978), S. 365-374 
    Details
    ISSN: 1432-0878
    Keywords: Previtellogenesis ; Oocyte ; Ultrastructure ; Acerentomon gallicum ; Protura
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary At the onset of previtellogenesis, the oocytes of Acerentomon gallicum begin to grow and increase their content of organelles. The nuage material in the oocytes at first increases in amount, then declines gradually to disappear completely from oocytes that have attained 50 μm in diameter. During the growth period, new dictyosomes, mitochondria and ribosomes appear. Numerous vesicles become detached from the cell membrane and subsequently fuse into cisternae, thus forming extensive complexes of the rough endoplasmic reticulum. In oocytes with diameters between 50 and 100 μm the Golgi complexes show a considerable increase in activity, and many lamellar bodies arise from mitochondria that have undergone specific transformation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00209284
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  • 206
    Electronic Resource
    Electronic Resource
    Tormogen cell and receptor-lymph space in insect olfactory sensilla (1978)
    Springer
    Cell & tissue research 189 (1978), S. 549-554 
    Details
    ISSN: 1432-0878
    Keywords: Tormogen cell ; Receptor-lymph space ; Chemoreceptor ; Ultrastructure ; Histochemistry ; Calliphora (Insects)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary (1) The basiconic sensilla on the antennae of Calliphora resemble other insect epidermal sensilla; one or several bipolar sense cells are surrounded by three non-neural cells. (2) The apical cell membrane of the tormogen cell(one of the three accessory cells) forms microvilli coated internally with particles. (3) In the (extracellular) outer receptor-lymph space hyaluronic acid can be demonstrated histochemically. (4) Demonstration of non-specific alkaline phosphatase, Mg2+-activated ATPase, and the presence of mitochondria in the apical part of the tormogen cell suggest active transport processes through these cells into the outer receptor-lymph space.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00209140
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  • 207
    Electronic Resource
    Electronic Resource
    Kinetics of functional and morphological changes during decoupling and recoupling induced by glycerol in isolated muscle fibres of the crayfish (1978)
    Springer
    Cell & tissue research 192 (1978), S. 167-185 
    Details
    ISSN: 1432-0878
    Keywords: T-system tubules ; Glycerol procedure ; Structure-activity relationship ; Ultrastructure ; Astacus fluviatilis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The development of ultrastructural changes in the T-system of isolated muscle fibres of the crayfish by the glycerol procedure is described in correlation with the dissociation of excitation-contraction (E-C) coupling as well as with recoupling of the E-C link. The sequence of events in the process of disconnection of the tubules is as follows: dilation of the T-system tubules, disconnection of the constricted tubular segments from the surface membrane and from the T-system vesicle, disappearance of the lumen and its disintegration. The decoupled state is characterised by the presence of round vesicles uniformly distributed in the entire volume of the fibre. The volume of vesicles accounts well for the residual postglycerol volume increase (15%) of the muscle fibres. Functional and structural recovery can be induced by reapplication of glycerol to fibres decoupled and vesiculated with concentrations of glycerol≦300mmol · l-1 in crayfish saline. The restitution starts with the organisation of the material of the disintegrated connecting segment of the T-system tubule into small vesicles which coalesce to form the tubule from the vesicular site. At the same time the surface membrane is invaginated toward the vesicle, thus forming the tubule from the surface membrane site. Recovery starts already in the first minute after application of glycerol and is completed within approximately 15min.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00231031
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  • 208
    Electronic Resource
    Electronic Resource
    Separation and maturation of gonadotrophs from 2A8 clonal cells in vitro (1978)
    Springer
    Cell & tissue research 189 (1978), S. 31-40 
    Details
    ISSN: 1432-0878
    Keywords: Pituitary cell clone ; LHRH-Sepharose ; Gonadotrophs ; Hypertrophy ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 2A8 clonal cells derived from the epithelium of Rathke's pouch of fetal rats were cultured in growth medium supplemented with fresh rat serum, median-eminence extract and l-thyroxine. Then, in order to isolate gonadotrophs, cyanogen bromide-activated Sepharose which was conjugated with LHRH (LHRH-Sepharose) was added to the culture medium. Fourteen days after incubation of 2A8 cells with LHRH-Sepharose, agranular and granular cells were rapidly bound to LHRH-Sepharose when fresh serum had previously been added in the medium. The cytoplasm of granular cells that were bound to LHRH-Sepharose contained spherical secretory granules (200–250 nm in diameter). These cells were similar in morphology to the FSH and LH gonadotrophs described by Kurosumi (1968). Moreover, many of them appeared as hypertrophied cells that resembled “castration” cells. These results demonstrate that LHRH conjugated to Sepharose can be used to separate gonadotrophs from other 2A8 cells, and it is suggested that the hypertrophy of some cells might be due to persistent stimulation by LHRH which is likely bound to receptors on the cell membrane.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00223119
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  • 209
    Electronic Resource
    Electronic Resource
    The ultrastructure of the herring bodies in rats subjected to different experimental conditions (1978)
    Springer
    Cell & tissue research 189 (1978), S. 41-51 
    Details
    ISSN: 1432-0878
    Keywords: Herring bodies (rat) ; Colchicine ; Cold ; Neurosecretion ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A study of the morphology of Herring bodies of the posterior pituitary lobe of rats treated with colchicine and/or exposed to low temperatures has been performed. After treatment with colchicine (20 μg in distilled water injected intracisternally) a predominance of Herring bodies with a large number of small “synaptic-like” vesicles surrounded by neurosecretory granules is found. Exposures to low temperature (4–6° C) result in an increase in the neurosecretory material and the Herring bodies show many neurosecretory granules of different densities. After treatment with colchicine and subsequent exposure to low temperatures, the Herring bodies are characterized by having a great number of autophagic bodies which become more numerous as the length of the exposure is increased; later autophagic vacuoles and lamellar bodies become evident.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00223120
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  • 210
    Electronic Resource
    Electronic Resource
    The ultrastructure and histochemistry of the mesenteric connective tissue of the cockroach Periplaneta americana L. (Insecta, Dictyoptera) (1978)
    Springer
    Cell & tissue research 189 (1978), S. 91-107 
    Details
    ISSN: 1432-0878
    Keywords: Connective tissue sheath ; Periplaneta ; Ultrastructure ; Histochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé La gaine conjonctive épaisse entourant l'intestin moyen de la Blatte Periplaneta americana a été étudiée en faisant appel à la microscopie photonique, électronique et l'histochimie. Cette couche conjonctive, reliée à l'épithélium mésentérique par une lame basale, traversée par des faisceaux musculaires, des trachées et des nerfs, contient de très nombreuses fibrilles de collagène, des fibrilles élastiques, des fibroblastes et des hémocytes. Au cours des premiers stades le matériel conjonctif est élaboré par des fibroblastes. Différentes réactions, en particulier le bleu alcian, la métachromasie et les digestions enzymatiques ont montré la présence de glycosaminoglycanes. La présence d'acide hyaluronique à tous les stades, l'apparition et l'augmentation des composés sulphatés ainsi que la présence de glycoprotéines ont été mises en évidence.
    Notes: Summary The thick layer of collagenous connective tissue around the mesenteron of the cockroach Periplaneta americana has been examined by light microscopy, electron microscopy and histochemical techniques. This sheath, connected to the mesenteric epithelium by a basal lamina and traversed by longitudinal and circular musculature, tracheae and nerves, contains numerous collagen fibrils, elastic fibers, fibroblasts and rare hemocytes. Development starts during the first instars with the production of connective tissue material by fibroblasts. Glycosaminoglycans have been observed with the use of various histochemical reactions, in particular alcian blue staining, metachromasia and enzymatic digestion. The reactions indicate the presence of hyaluronic acid in the various instars, the appearance and increase of sulphated components during development, and the presence of neutral glycoproteins.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00223123
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  • 211
    Electronic Resource
    Electronic Resource
    An ultrastructural study of periderm granules in the regenerating feather of the jungle fowl (1978)
    Springer
    Cell & tissue research 192 (1978), S. 319-326 
    Details
    ISSN: 1432-0878
    Keywords: Periderm granules ; Regenerating feather ; Ultrastructure ; Jungle fowl
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Periderm granules in the support cells of regenerating feathers of mature male Jungle Fowls were studied ultrastructurally and histochemically. Histochemical results showed the absence of carbohydrate and lipid, and the presence of protein in the periderm granules. The periderm granules were measured at successive levels of feather regeneration. The mean size of the periderm granules increased significantly as the regenerating feather matured, and this observation was suggestive of a storage function, perhaps of surplus or waste protein. The cells in which the periderm granules are found also contain glycogen. There are numerous desmosomal junctions on their interdigitating plasma membranes. These transient cells may collect waste, provide nutrition, and serve as a protective barrier for the definitive cells of the regenerating feather.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220749
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  • 212
    Electronic Resource
    Electronic Resource
    A further type of transient cytoplasmic organelle in human spermatids (1978)
    Springer
    Cell & tissue research 192 (1978), S. 359-361 
    Details
    ISSN: 1432-0878
    Keywords: Spermatids ; Human ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Osmiophilic granules with surrounding vesicles resembling flower-like structures occur transiently during the differentiation of human spermatids. These organelles are incorporated into the residual bodies when mature spermatids are released from the germinal epithelium.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220752
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  • 213
    Electronic Resource
    Electronic Resource
    Ultrastructural changes in the fat body of adult female Aedes aegypti in relationship to vitellogenin synthesis (1978)
    Springer
    Cell & tissue research 186 (1978), S. 499-506 
    Details
    ISSN: 1432-0878
    Keywords: Fat body ; Aedes aegypti ; Vitellogenin ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the fat body of Aedes aegypti was followed from emergence through a blood meal. Changes in the volume of protein granules and lipid droplets were also examined. The relationship of these events to the known endocrinology of vitellogenin synthesis in mosquitoes is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224938
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  • 214
    Electronic Resource
    Electronic Resource
    Leptomeric fibrils and T-tubule desmosomes in the Z-band region of the mouse heart papillary muscle (1978)
    Springer
    Cell & tissue research 188 (1978), S. 205-215 
    Details
    ISSN: 1432-0878
    Keywords: Myocardium ; Mouse ; Ultrastructure ; Leptofibrils ; Desmosomes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The papillary muscle of the heart of adult white mice is investigated. Intrafibrillarly located leptomeric fibrils, frequently encountered in the Z-band region of the myofibrils. The leptomeric fibrils are always running in a transverse direction and often in close proximity to the transverse tubules (which are also located at this level). There seems to be a close connection between the dense striae of the leptofibrils and the Z-bands of ordinary myofibrils. The leptomeric fibrils are spindle-shaped and have a length varying between 0.6 and 1.2 μm. The banding periodicity of the fibrils is approximately 0.16 μm. Occasionally desmosomes are observed in the T-tubule system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00222631
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  • 215
    Electronic Resource
    Electronic Resource
    Ultrastrukturell-morphometrische Veränderungen des Ganglion spirale cochleae bei der Ratte nach Beschallung (1978)
    Springer
    European archives of oto-rhino-laryngology and head & neck 220 (1978), S. 193-199 
    Details
    ISSN: 1434-4726
    Keywords: Cochlear spiral ganglion ; Ultrastructure ; Morphometry ; Influence of broad band noise ; Cochleare Spiralganglien ; Ultrastruktur ; Morphometrie ; Beschallung mit Breitbandrauschen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Nach 40minütiger Beschallung des Ohres mit Breitbandrauschen von 105 dB SPL waren bei den Ratten elektronenoptisch noch keine sicheren Veränderungen an den Spiralganglienzellen festzustellen. Erst ultrastrukturell-morphometrisch ließen sich statistisch signifikante Veränderungen des Chondrioms und der Organellen des Leistungsstoffwechsels bei den granulären Spiralganglienzellen nachweisen. Der Volumenanteil der Mitochondrien im Einheitsvolumen Zytoplasma nahm zu. Auch das Volumen und die Oberfläche des RER sowie das Volumen der freien Ribosomen und der Nucleolen vergrößerten sich im Einheitsvolumen Zytoplasma bzw. pro Zelle. Die physiologische Bedeutung dieser Veränderungen wurde diskutiert. Die Resultate zeigen u. a., daß Veränderungen der Cytoarchitektur in den granulären Spiralganglienzellen morphometrisch früher als elektronenoptisch registriert werden können.
    Notes: Summary The comparison of ultrastructural and ultrastructural-morphometric findings in spiral ganglion cells subsequent to broad band noise with 105 dB SPL over a period of 40 min demonstrates that there are morphometric changes of the cytoarchitecture of granular ganglion cells even without evident ultrastructural changes. Morphometric analyses shows a significant extention of the volume proportion of mitochondria per unit volume cytoplasm. The volume and the surface of the rough endoplasmic reticulum, the volume of the free ribosomes and the average single volume of the nucleoli increase per granular ganglion cell. The physiologic significance of these changes is discussed. The results show that changes of the cytoarchitecture of granular spiral ganglion cells are earlier detected by morphometry than by ultrastructural description.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00457487
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  • 216
    Electronic Resource
    Electronic Resource
    Development of the filiform hairs on the cerci of Gryllus bimaculatus Deg. (Saltatoria, Gryllidae) (1978)
    Springer
    Cell & tissue research 187 (1978), S. 1-24 
    Details
    ISSN: 1432-0878
    Keywords: Insect sensillum ; Mechanoreceptor ; Development ; Ultrastructure ; Gryllus bimaculatus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The filiform hairs, mechanoreceptors of Gryllus, pass through six developmental stages during the last larval stage. The cytoplasm of their sense cells suggests intensive synthesis of protein for cellular metabolism and intercytoplasmic exchange of material via glial evaginations. Ultrahistochemical tests demonstrated acid phosphatase in the lysosomes as well as in components of the Golgi apparatus. There was no significant change in the appearance of the sense cell cytoplasm, indicating a maintained functional state also during molting. The new cuticular apparatus is formed after apolysis by the three enveloping cells. Formation of the replacement hairs is initiated by a cytoplasmic outgrowth of the trichogen cell. During morphogenesis of the new hair, the microtubules serve as a cytoskeleton and probably control the flow of vesicles, which contain phenol oxidase, also demonstrated in the Golgi apparatus, and are incorporated into the new cuticle. Bundles of microfibrils are involved in the surface sculpturing of the replacement hair. The trichogen cell also forms a number of structural elements, e.g. the “cup” and “strut” marked geometric peculiarities of which indicate that they are important in the spatial orientation of the dendrite and thus also in transduction. Reduction of the apical cell membrane of the tormogen cell after apolysis permits unrestricted growth of the new hair into the exuvial space. The tormogen cell participates in the formation of the joint membrane, parts of the socket and the articulation of the hair.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220615
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  • 217
    Electronic Resource
    Electronic Resource
    Early effects of prolactin on lactating rabbit mammary gland (1978)
    Springer
    Cell & tissue research 187 (1978), S. 25-43 
    Details
    ISSN: 1432-0878
    Keywords: Lactation ; Prolactin ; Secretion ; Caseins ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé Les effets de la prolactine, sur la sécrétion des protéines du lait, ont été étudiés grâce à des incubations de tranches de glandes mammaires de lapines en lactation. Dès 15min après l'addition de l'hormone au milieu d'incubation, la morphologie de la cellule est modifiée: le volume relatif des vésicules et des saccules Golgiens est fortement augmenté. Lorsque la prolactine est rajoutée, immédiatement après un marquage en 〈pulse〉 des protéines (pendant 3 min par la L-leucine 3H), elle provoque, en une heure, une augmentation de la sérétion des caséines radioactives dans le milieu d'incubation. Cette augmentation de la quantité de caséines sécrétées ne provient ni d'une augmentation du transit intracellulaire des protéines néosynthétisées (étudié par autoradiographie en Microscopie Electronique), ni d'une augmentation d'incorporation des acides aminés (mesurée par l'incorporation d'acides aminés non métabolisables), ni d'une augmentation de la synthèse protéique totale, dans le délai d'une heure. Les relations possibles entre l'action de la prolactine sur l'aspect morphologique d'un organite cellulaire tel que l'appareil de Golgi et sur la sécrétion des caséines sont discutées.
    Notes: Summary Effects of prolactin on the secretion of milk proteins have been investigated by incubating mammary tissue fragments from lactating rabbits. Within 15min of adding the hormone to the incubation medium, cell morphology is modified: the relative volume occupied by the Golgi region is greatly increased. When prolactin is added immediately after a pulse labelling of proteins (3 min with 3H-L-leucine), the amount of labelled caseins secreted during one hour is significantly increased. This increase proceeds neither from an acceleration of intracellular transit of caseins (as shown by electron microscopic autoradiography) nor by an enhancement of amino acid uptake (as measured by incorporation of non-metabolizable amino acids) nor by an increase of overall protein synthesis, during the first hour. The action of prolactin on the morphology of such subcellular organelles as the Golgi apparatus and its influence on casein secretion are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220616
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  • 218
    Electronic Resource
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    Cytological observations on the blood and hemopoietic tissue in the crab, Callinectes sapidus (1978)
    Springer
    Cell & tissue research 187 (1978), S. 79-96 
    Details
    ISSN: 1432-0878
    Keywords: Crustacean hemocytes ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A fine structural analysis of hemocytes recovered from the pericardial sinus of the blue crab (Callinectes sapidus) demonstrates that hyaline cells, intermediate cells, and granuloyctes are present in the hemolymph. A detailed consideration of their shared and differing cytological features suggests that the various blood cells represent different stages of cytogenesis along a common or single path of cellular differentiation. The potential functional complexity of the hemocytes is attested to by the occurrence within their cytoplasm of three and/or possibly four morphologically distinct types of inclusion bodies, and other membrane-bounded compartments (e.g., lysosome-like structures, autophagic vacuoles, peroxisome-like bodies) whose function is unknown. Preliminary examination of the well-developed Golgi organelle in the intermediate cells and granulocytes indicates its probable participation in the elaboration of the inclusion bodies; however, the details of its role in granulogenesis and in the known plurifunctional capacities of these cells remain obscure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220620
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    Unusual mitochondrial ultrastructure in the pig adrenal cortex (1978)
    Springer
    Cell & tissue research 187 (1978), S. 129-134 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal cortex (Pig) ; Mitochondria ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Unusually large mitochondria with few cristae were observed in the cells of the boundary layer between the zonae fasciculata and reticularis of the pig adrenal. These mitochondria occasionally contained parallel arrays of beaded filaments which appeared to be composed of repetitive electron opaque particles, measuring 10 to 11 nm in diameter. The possibility that these filaments are arranged in closely packed arrays of tubular structures with a central filament is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220624
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    Studies on the midgut of Centropages typicus (Copepod, Calanoid) (1978)
    Springer
    Cell & tissue research 187 (1978), S. 333-353 
    Details
    ISSN: 1432-0878
    Keywords: Midgut ; Centropages typicus (Copepod, Calanoid) ; Structure ; Ultrastructure ; Digestive function
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary From a structural study of the midgut of Centropages typicus, three main zones presenting different cellular associations may be defined. The ultrastructural study carried out allows us to distinguish several cell types. The four principal cell categories (E, R, F and B) show a more or less marked resemblance with those identified in the Malacostraceans, especially in the hepatopancreas of Decapods. The three types R, F and B, which are subdivided according to their localization (R and R′) or their developing stages (F1, F2; B1 to B5), are recognized by the following characteristics: R-cells with smooth endoplasmic reticulum and high microvilli (zones I and III); F-cells with rough endoplasmic reticulum and short or spherical microvilli (zones I and II); B-cells with a large vacuolar apparatus made up of lysosome-like dense bodies associated with vacuoles originating from pinocytosis (zone II). From the comparisons of morphological, ultrastructural and histochemical results concerning Centropages typicus with author's data, we propose and discuss these functions for the three principal cell types: synthesis and secretion of pre-digestive enzymes (F1 and F2-cells); enzyme synthesis, intracellular digestion and extrusion (B1 to B5-cells); absorption (R and R′-cells).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224375
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    Morphological changes in the ultrastructure of the thyroid epithelium of Notophthalmus viridescens after hypophysectomy and TSH- and prolactin stimulation (1978)
    Springer
    Cell & tissue research 187 (1978), S. 305-313 
    Details
    ISSN: 1432-0878
    Keywords: Thyroid ; Ultrastructure ; Hypophysectomy ; TSH- and prolactin treatment ; Notophthalmus viridescens
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the newt, Notophthalmus viridescens, hypophysectomy results in progressive atrophy of the thyroid cells to the point of irreversible degeneration. After exclusive TSH-stimulation of hypophysectomized newts, increased endocytotic activity of the follicular epithelium is observed. Prolactin stimulation under the same conditions prevents atrophy but does not result in increased cell activity, as expressed by the reduced amount of microvilli and the lack of endocytotic activity. Combined TSH- and prolactin stimulation also results in cell activation, but the activation level of exclusively TSH-stimulated cells is not reached. Although prolactin prevents cellular atrophy and degeneration of the follicular epithelium, it reduces the TSH-induced activation of the thyroid epithelium.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00224372
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    Ultrastructure of differentiating hemocytes in the embryo of Oncopeltus fasciatus Dallas (Insecta, Heteroptera) (1978)
    Springer
    Cell & tissue research 187 (1978), S. 479-488 
    Details
    ISSN: 1432-0878
    Keywords: Embryonic hemocytes ; Insecta ; Oncopeltus fasciatus ; Differentiation ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The hemocytes of Oncopeltus differentiate rather early during embryogenesis. They are segregated by the mesoderm soon after its formation (about 50h after egg deposition). Newly segregated hemocytes show the “typical” features of “embryonic” cells: many free ribosomes, a few strands of rough ER, the cisternae of which are considerably distended, electron lucent vacuoles around the periphery, and glycogen deposits. A few hours thereafter the hemocytes undergo striking subcellular changes. First, glycogen, electron lucent vacuoles and rough ER disappear and phagocytotic activity can be observed. Golgi complexes become well expressed and give rise to electron dense vesicles which fuse to larger bodies. Then, rough ER develops again and occupies large areas of the cytoplasm. Its cisternae are often considerably distended by proteinaceous secretions. All hemocytes undergo the same steps of differentiation. Embryonic hemocytes obviously play a decisive role in the elimination of waste products, in particular of tissue debris that results from programmed cellular death. The significance of the conspicuous protein secretions is not fully understood. They may participate in the deposition of the acellular connective tissue, or may have some of the other functions ascribed to insect blood cells. Larvae and imagines of Oncopeltus have four types of hemocytes, which agree rather well with those found in Rhodnius (Lai-Fook, 1970). All embryonic hemocytes, aside from the newly segregated ones, represent plasmatocytes but, unlike plasmatocytes of postembryonic stages, they contain no large inclusion bodies. Newly segregated embryonic hemocytes, in addition to their “typical embryonic” features, have some similarities with larval and adult prohemocytes. Oenocytoids and granulocytophagous cells are absent in the embryo. Some aspects concerning the differentiation and classification of hemocytes are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00229612
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    The paramedial neurosecretory cells of the suboesophageal ganglion in the cricket, Teleogryllus commodus (Walk.) (1978)
    Springer
    Cell & tissue research 187 (1978), S. 495-506 
    Details
    ISSN: 1432-0878
    Keywords: Suboesophageal ganglion (cricket) ; Paramedial neurosecretory cells ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The paramedian neurosecretory cells (PNC) (A-type) in the suboesophageal ganglion of the cricket, Teleogryllus commodus (Walk.), have been studied by electron microscopy. In control animals (10 day-old virgin females) three different cell stages could be distinguished: Stage 1 shows a variable content of elementary granules and characteristics of actively synthesising cells. Stage 2 is characterised by the presence of numerous fusion bodies, which are formed by the coalescence of elementary granules, presumably for storage purposes. In stage 3 granules are degraded in lysosomes (?). While the production of material rich in cysteine increases after ovariectomy (Dürnberger et al., 1978), the fine structure of the cells is essentially unchanged. The only noted differences are an increased lysosomal synthetic activity and the existence of stages intermediate between 2 and 3, which were never found in control animals. The functional significance of the different stages is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00229614
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    Influence of gonadotropic hormones on the ultrastructure of rat pinealocytes (1978)
    Springer
    Cell & tissue research 188 (1978), S. 133-141 
    Details
    ISSN: 1432-0878
    Keywords: Pineal organ, rat ; Ultrastructure ; Gonadotropic hormones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The influence of gonadotropic hormones on the ultrastructure of rat pinealocytes was studied. Human chorionic gonadotropin (HCG) as well as pregnant mare serum gonadotropin (PMSG) caused a marked activation of pinealocytes. It is characterised by a conspicuous proliferation of the granular endoplasmic reticulum and Golgi apparatus as well as an increase in number of dense core vesicles, mitochondria, dense bodies, subsurface cisternae and vesicles in the terminal buds of pinealocyte processes. The changes after HCG administration were more pronounced than after PMSG.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00220520
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    Changes in the adrenal cortex of the rat after chronic administration of the steroidogenic inhibitor U-8113 (1978)
    Springer
    Cell & tissue research 190 (1978), S. 123-134 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal ; Steroidogenesis ; Inihibitor ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In concert with studies of the effects of various pharmacologic inhibitors of corticosteroidogenesis on adrenocortical morphology, U-8113, an analog of amphenone B, was administered daily to Sprague-Dawley rats for 7, 14, 21 or 30 days. The primary morphological responses involved increases in adrenal weight, width of zona fasciculata, width of zona reticularis, intracellular lipids, mitochondrial size, mitochondrial vacuolation and crystalline-like inclusions, small coated vesicles, lysosomes, autophagic vacuoles and cholesterol ester clefts. In particular, the increases in lysosomes, coated vesicles and autophagic vacuoles containing morphologically altered mitochondria were considered reflective of mechanisms designed to maintain cellular integrity amidst functional impairment. Lipid analysis revealed marked increases in cholesterol esters and phospholipids, supportive of morphological observations. When permitted a 14 day recovery period following either 14 or 30 days of inhibitor therapy, most fine structural alterations and lipid derangements were diminished, and the cells approximated normal parameters.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00210042
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    The respiratory epithelium in the lungs of the slow-worm, Anguis fragilis (1978)
    Springer
    Cell & tissue research 190 (1978), S. 337-347 
    Details
    ISSN: 1432-0878
    Keywords: Respiratory epithelium ; Anguis fragilis ; Pneumonocytes ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The epithelium covering the respiratory portion in the lung of the slow-worm (Anguis fragilis) has been studied by electron microscopy. The epithelium is composed of two different types of pneumonocytes. The type I pneumonocytes are roughly squamous and their cytoplasmic sheets spread over relatively large areas of the septal walls. These cytoplasmic sheets are attenuated in regions where they overlie septal capillaries; they usually have extensive areas of contact with adjacent cells. The type II pneumonocytes are also squamous but are more compact and possess more organelles. Their osmiophilic inclusion bodies are especially conspicuous. Most of their microvilli are concentrated on the surfaces of cytoplasmic “hillocks”. Deposits of membranous material are present in the air sacs. The morphological evidence suggests that the type II cells of Anguis secrete surface-active material.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218179
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    An ultrastructural study of regeneration of minced smooth muscle in the vas deferens of the guinea-pig (1978)
    Springer
    Cell & tissue research 190 (1978), S. 481-493 
    Details
    ISSN: 1432-0878
    Keywords: Smooth muscle ; Regeneration ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Electron microscopic studies were made of the regeneration of minced smooth muscle of the vas deferens of the guinea-pig 3 days to 15 weeks after operation. At 3–5 days the mince contained degenerating smooth muscle cells and dedifferentiating cells showing characteristics of embryonic smooth muscle cells: numerous free ribosomes, well developed rough endoplasmic reticulum and Golgi apparatus with few peripherally placed myofilaments associated with dense bodies. During the first two weeks of regeneration, scattered cells surrounded by debris and collagen were separated by a large extra-cellular space. After three weeks, extracellular space was reduced to near normal values. Regenerating cells had a shorter length than normal cells, but during later stages of regeneration they showed an increase in diameter. Muscle effector bundles began to form after 2 to 3 weeks. Initially there were large gaps between the muscle cells, but at later stages of bundle formation, the extracellular space between the muscle cells was much reduced. From 3 weeks, arterioles appeared between the smooth muscle bundles in the regenerating areas. Regeneration of individual smooth muscle cells was complete by 15 weeks after the operation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219559
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    The ultrastructure of pinealocytes in the golden mole (Amblysomus hottentotus) with special reference to the granular vesicles (1978)
    Springer
    Cell & tissue research 191 (1978), S. 39-56 
    Details
    ISSN: 1432-0878
    Keywords: Pinealocytes ; Golden mole ; Secretory process ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé Les pinéalocytes de la glande pinéale de la Taupe dorée Amblysomus hottentotus (Mammifère aveugle et vivant toujours dans une obscurité complète) examinés au microscope électronique ont été comparés à ceux d'autres Mammifères. Une seule population de pinealocytes a été observée. Mitochondries, ribosomes, réticulum endoplasmic granulaire, inclusions lipidiques et rares structures lysosomiales sont présents dans le périkaryon. De nombreux grains de glycogène formant le plus souvent de typiques “accumulations” ont été fréquemment observés associés à des vacuoles. Un grand nombre de vésicules granulaires est la caractéristique première des pinéalocytes. Un phénomène d'excrétion, caractérisé par une dissolution in situ du coeur dense, a été observé. L'importance physiologique de ces vésicules granulaires est discuté.
    Notes: Summary The ultrastructure of the pinealocytes of the golden mole (Amblysomus hottentotus), a blind subterranean mammal living in complete darkness, was examined and compared with that of pinealocytes of other mammals. On the basis of the presence of granular vesicles and glycogen granules, only one population of pinealocytes was found. Large mitochondria, ribosomes, lipid inclusions and scarce lysosomes were observed in the perikaryon. Numerous glycogen granules, often forming typical accumulations, were frequently found to be associated with typical vacuoles. An extraordinary large number of granular vesicles is characteristic of the golden mole pinealocyte. Phenomena of excretion of compound(s) stored in the granular vesicles were identified. Morphologically this is characterized by dissociation of its granular core in situ while its limiting membrane is preserved. The physiological significance of the secretory process characterized by the formation of these granular vesicles is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00223214
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    The uterovaginal sperm host glands of the quail (Coturnix coturnix japonica) (1978)
    Springer
    Cell & tissue research 191 (1978), S. 101-114 
    Details
    ISSN: 1432-0878
    Keywords: Sperm host glands ; Quail (Coturnix coturnix jap.) ; Ultrastructure ; Ultracytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ultrastructural and ultrahistochemical studies were performed on the uterovaginal sperm host glands of the quail (Coturnix coturnix japonica). The proximal parts of the glandular necks are lined by a pseudostratified epithelium, consisting of high columnar ciliated cells and small, irregular shaped, basal cells. The true glandular epithelium is composed only of columnar cells with microvilli on their luminal end. A characteristic luminal feature is a large lipid droplet in the perinuclear region. In the subplasmalemmal region numerous tubular profiles are seen which could represent a cellular resorption system. To evaluate the absorptive capacity of the Uterovaginal sperm host glands, tracer studies with HRP, ferritin, lanthanum and ruthenium red were undertaken. Since between 5 min and 3 h after injection no absorption could be found with the techniques mentioned, it is suggested that phagocytosis of spermatozoa by the glandular epithelium is not likely to occur.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00223219
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    The structure of the nervous system of the pluteus larva of Strongylocentrotus purpuratus (1978)
    Springer
    Cell & tissue research 191 (1978), S. 233-247 
    Details
    ISSN: 1432-0878
    Keywords: Nervous system ; Pluteus ; Ultrastructure ; Echinoderms ; Strongylocentrotus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Tissues that have the ultrastructural characteristics of nervous tissues are associated with ciliary and muscular elements of the pluteus larva of Strongylocentrotus purpuratus. The nerve cells are found along the margins of the ciliary bands, which are composed predominantly of spindle-shaped ciliated cells. The nerve cells contribute axonal processes to a tract of axons, which runs at the base of the ciliary band throughout its length. Axonal tracts, in the esophagus, lie beneath the circumesophageal muscles. Branched microvilli, which have been interpreted as sensory receptors, are located on the oral side of the main ciliary band and connect with the nerve cells in the ciliary band. The nervous structures described here, and other tissues of the pluteus that have been previously described as nervous, are compared on the basis of their association with receptor and effector organs, and their ultrastructural characteristics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00222422
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    The ultrastructure of multilamellar bodies and surfactant in the human lung (1978)
    Springer
    Cell & tissue research 193 (1978), S. 219-229 
    Details
    ISSN: 1432-0878
    Keywords: Multilamellar bodies (human lung) ; Surfactant ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Normal tissues from human lungs were dehydrated through Epon 812 resin to retain many of the lipids and carbohydrates in thin section. The three-dimensional structure of the multilamellar body was determined. The paired layer of phospholipid heads (PH) is 36Å thick; the layer of fatty-acid tails (FA) is 31Å, the same as reported previously for non-human primates and rodents. The human multilamellar body is apparently unique: the lamellae of the major focus divide into two or three lamellae; the matrix material of the core is without vesicular bodies and a projection core is present. When compared with those of the rat, human tissues contain a greater number of lamellar foci and fewer lamellae per focus. The presence of a peripheral layer of lamellae, an ever-present external limiting membrane, and the fusion of multilamellar bodies are also characteristic. Tubular myelin surfactant has the same appearance as in other mammals. Multilamellar bodies were observed in direct communication with Golgi vesicles. Their origin from multivesicular bodies and their maturation through secretion and exocytosis were demonstrated. Untransformed multilamellar bodies in the alveolar space demonstrated three periodicities (P): (1) compact regular lamellae, PH = 36Å, FA = 31Å, P = 66Å; (2) compact broad lamellae, PH = 72Å, FA = 22Å, P = 94Å; (3) loose lamellae, PH = 36Å, FA = 36Å, FA = 31Å with a variable interlamellar space.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00209036
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    High resolution radioautographic study of newly formed protein in striated muscle with emphasis on red and white fibres (1978)
    Springer
    Cell & tissue research 193 (1978), S. 269-282 
    Details
    ISSN: 1432-0878
    Keywords: Striated muscle ; Proteins ; Radioautography ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The elaboration and distribution of newly formed proteins in the striated muscle of 21-day-old mice were investigated by quantitative radioautography at intervals between 2 and 240 min after intravenous injection of tritiated leucine. In radioautographs, the localization and the relative label concentration were comparatively estimated for the different components of mitochondria-rich fibres, in particular of red fibres, from the tibialis anterior muscle and of mitochondria-poor fibres from the oesophageal muscle. As early as 2 min after injection, radioactivity was detected over the nucleus, the polysome-rich sarcoplasm, the A and I bands, the Z lines, and the mitochondria in the two fibre types. Label localization did not change with time. The relative label concentration increased similarly in the polysome-rich sarcoplasm and the A and I bands of both fibre types within 30 min after injection, a confirmation that biosynthesis of myofibrillar proteins takes place rapidly. In each case, concentration was higher in the Z lines than in the I bands, and higher in the I bands than in the A bands, thus showing “in vivo” that the rates of synthesis of sarcomere protein components are not uniform. However, the relative label concentration was found to be higher in the Z lines of mitochondria-poor fibres than of mitochondria-rich fibres: this suggests that a higher synthetic rate of Z line protein, and probably of α actinin, is characteristic of the first type. Inversely, the concentration was higher in the mitochondria of mitochondria-rich fibres. This lead to the belief that high rate of protein synthesis in these organelles may account for the high rate of label incorporation into this type of fibre.
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    URL: http://dx.doi.org/10.1007/BF00209040
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    Extravascular transfer within the anuran pars intermedia (1978)
    Springer
    Cell & tissue research 193 (1978), S. 297-313 
    Details
    ISSN: 1432-0878
    Keywords: Pars intermedia ; Peroxidase ; Ultrastructure ; Extravascular space ; Stellate cell
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary To study the transport of protein from the blood into and throughout the sparsely vascularized pars intermedia of anurans, the electrondense tracer, horseradish peroxidase (HRP) was injected into the vascular system of adult frogs. A strong reaction product was localized in small vesicles in the cytoplasm of that portion of the stellate cells immediately beneath the vascular spaces. Also, within two minutes after an injection of HRP, which was given during a period of one minute, the reaction product was seen in the extracellular spaces between the stellate and/or MSH secretory cells throughout the gland. Additionally, it appeared that HRP was pinocytosed by the stellate cell processes in the interior of the pars intermedia. Since frogs adapted to different backgrounds were perfused with HRP for a variety of time periods, from 3 to 90 min, it was thought that it would be possible to trace the pathway of the HRP-filled vesicles as they moved through the stellate cells. There did not appear to be a migration of these vesicles within the cells. Because of the electron density of the HRP, the tortuous extensions from the perivascular spaces of the capillary plexus intermedius were obvious as they ramified into the pars intermedia and pars nervosa. In the frogs not injected with HRP, it was possible to observe the substructure of these ramifications which paralleled the stellate cells and formed enlargements at the convergence of the stellate cell processes and sometimes the nerve processes. An extravascular, many-branched transport system that penetrates the parenchyma is discussed in addition to the possible transfer role of the stellate cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00209042
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    Scanning electron microscope studies of the egg shell in some anostraca (Crustacea: Branchiopoda) (1978)
    Springer
    Cell & tissue research 193 (1978), S. 337-351 
    Details
    ISSN: 1432-0878
    Keywords: Egg shells ; Anostraca ; Alveolar meshwork ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The tertiary shell of the eggs of anostracan crustaceans consists of two layers, an outer cortex and an inner alveolar layer. Scanning electron microscope studies show that, in most species, these layers are separated by a subcortical space which intercommunicates with spaces in the cortex and with the meshwork of the alveolar layer. No evidence was found for direct communication between pores on the surface of Branchipus stagnalis eggs and the subcortical space. No surface pores were found in the eggs of Branchinecta packardi, Chirocephalus diaphanus, Anemia salina, nor in eggs of the notostracan Triops cancriformis. Similarities in structure and possible functions of the egg shells of anostracan crustaceans and certain insects are discussed in relation to similarities in certain features of their environments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00209045
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    The pineal gland of the gerbil, Meriones unguiculatus (1978)
    Springer
    Cell & tissue research 193 (1978), S. 323-336 
    Details
    ISSN: 1432-0878
    Keywords: Pineal gland ; Gerbil ; Pinealocytes ; Concretions ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Electron microscopy was employed in a study of the pineal gland of the Mongolian gerbil (Meriones unguiculatus). It was determined that the gerbil pineal gland contains pinealocytes and glial cells with the pinealocytes being the predominant cell type. The pinealocytes contain numerous organelles traditionally considered as being either synthetic or secretory in function such as an extensive Golgi region, smooth (SER) and rough (RER) endoplasmic reticulum, secretory vesicles and microtubules. Other cytoplasmic components are also present in the pinealocytes (synaptic ribbons, subsurface cisternae) for which no function has been assigned. Dense-cored vesicles are rare. Vacuolated pinealocytes are present and appear to be intimately associated with the formation of the pineal concertions. Evidence presented supports the proposal that the concretions form within the vacuoles. Once the concretions reach an enlarged state, the vacuolated pinealocytes break down and the concretions are thus extruded into the extracellular space where they apparently continue to increase in size. The morphology of the glial cells was interpreted as indicative of a high synthetic activity. The glial cells contain predominantly the rough variety of endoplasmic reticulum and form an expansion around the wide perivascular area.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00209044
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    Sarcotubular development in dystrophic skeletal muscle cells (1978)
    Springer
    Cell & tissue research 194 (1978), S. 125-130 
    Details
    ISSN: 1432-0878
    Keywords: Sarcotubular development ; Chick embryo ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Dilations of the sarcotubular system and misaligned myofilaments have been reported as early indicators of muscular dystrophy in skeletal muscle. Since the developing tubular component is believed instrumental in initial myofilament alignment during myogenesis, tubular development is evaluated using normal and dystrophic chick embryo skeletal muscle and cultures of normal and dystrophic embryonic pectoral muscle incubated in the presence of horse spleen ferritin. Comparisons of the findings show that periodic tubules are absent from dystrophic somitic muscle and that invaginating tubules from the sarcolemma are found in fewer, randomly located areas of dystrophic pectoral muscle cells. The results indicate that the tubular component is not involved in the bizarre vesiculations seen in mature dystrophic muscle, however, the malalignment of dystrophic myofilaments is probably the result of the poorer development of the T system in this muscle.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00209238
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    Distribution, ontogeny and ultrastructure of pancreatic polypeptide (PP) cells in the pancreas and gut of the chicken (1978)
    Springer
    Cell & tissue research 194 (1978), S. 377-386 
    Details
    ISSN: 1432-0878
    Keywords: Pancreas ; Gut ; Pancreatic polypeptide (PP) cells ; Immunocytochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Pancreatic polypeptide (PP) cells in the pancreas and gut of chickens were studied by immunocytochemistry. In the pancreas PP cells were numerous and disseminated in the exocrine parenchyma. In this location they were first seen at the 9th day of incubation, i.e. several days after the appearance of glucagon, insulin and somatostatin cells. Very large numbers of these cells occurred from about the 14th day until shortly after hatching when the PP cell frequency was somewhat reduced. At the 17th day of incubation PP cells appeared in the duodenum. Subsequently the number of PP cells in the duodenum increased, and PP cells began to appear also in the jejunum-ileum (19th day) and in the proventriculus and colon (21st day). At hatching and a few days thereafter, PP cells were relatively numerous in the small intestines but much less frequent in the proventriculus and colon. One week after hatching PP cells had disappeared from the colon but remained in the proventriculus and small intestines. Ultrastructurally the PP cell was clearly distinguishable from the insulin, glucagon and somatostatin cells. It was characterized by the presence of spherical cytoplasmic granules which were membrane-bound and moderately electron dense. Areas of firm adhesion between PP cells and acinar cells in the form of desmosomes and possibly also gap junctions were observed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236159
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  • 238
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    Ultrastructural changes in the dermal chromatophore unit of Hyla arborea during color change (1978)
    Springer
    Cell & tissue research 194 (1978), S. 405-418 
    Details
    ISSN: 1432-0878
    Keywords: Hyla arborea ; Reflectance spectrophotometry ; Ultrastructure ; Color change ; Chromatophores
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die strukturellen Veränderungen der Chromatophoren beim Farbwechsel von Hyla arborea wurden mit Hilfe von Elektronenmikroskopie und Reflexions-Mikrospektrophotometrie untersucht. Während des Wechsels von einer hellgrünen zu einer dunkelgrünen Farbe breiten sich die Melanosomen aus, bis sie schließlich die Iridophoren und teilweise auch die Xanthophoren umhüllen; die becherförmigen Iridophoren werden zylinderoder kegelförmig. Gleichzeitig verändern die Purintäfelchen ihre Orientierung parallel zur Oberseite der Zelle und sind unregelmäßiger ausgerichtet; die linsenförmigen Xanthophoren werden plattenförmig. Der Wechsel von grüner zu grauer Färbung scheint stets über Schwarzgrün oder Dunkelolivgrün zu gehen. Die Xanthophoren keilen sich dann zwischen die Iridophoren ein und liegen in der grauen Haut oft unterhalb der letzteren; die Pterinosomen sammeln sich in der Peripherie der Zelle, während sich die Carotenoidvesikel um den Kern herum häufen. Die Iridophoren in der grauen Haut sind fast kugelförmig mit Purintäfelchen in konzentrischen Schichten. Eine hellgraue Färbung geht aus einer dunkelgrauen durch Aggregation der Melanosomen hervor. Die Chromatophorenwerte (“chromatophore values”), die Nielsen und Dyck (1978) für Hyla cinerea definierten, sind auch für Hyla arborea verwendbar; die Annahmen, die diesen Werten zugrunde liegen, werden jetzt ultrastrukturell gestützt.
    Notes: Summary The structural changes in the chromatophores of Hyla arborea related to changes in skin color were studied by electron microscopy and reflectance microspectrophotometry. During a change from a light to a darker green color, the melanosomes of the melanophores disperse and finally surround the iridophores and partly the xanthophores. The iridophores change from cup-shape to a cylindrical or conical shape with a simultaneous change in the orientation of the platelets from being parallel to the upper surface of the iridophores to being more irregular. The xanthophores change from lens-shape to plate-shape. The color change from green to grey seems always to go through a transitional black-green or dark olive green to dark grey. During this change the xanthophores migrate down between the iridophores, and in grey skins they are sometimes found beneath them. The pterinosomes gather in the periphery of the cell, while the carotenoid vesicles aggregate around the nucleus. The iridophores in grey skin are almost ball-shaped with concentric layers of platelets. A lighter grey color arises from a darker grey by an aggregation of melanosomes. The chromatophore values previously defined for Hyla cinerea are applicable in Hyla arborea, and the ultrastructural studies support the assumptions previously made to explain these values.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236162
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  • 239
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    The tegmental reticular nucleus: a cytoarchitectonic, golgi, fluorescence histochemical and ultrastructural analysis (1978)
    Springer
    Cell & tissue research 194 (1978), S. 463-479 
    Details
    ISSN: 1432-0878
    Keywords: Tegmental reticular nucleus (Bechterew) ; Serotonin neurons ; Reticular formation ; Ultrastructure ; Synaptic organization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The organization of the tegmental reticular nucleus of von Bechterew (TRN) has been analyzed in Nissl and Golgi material, by fluorescence histochemistry, and by electron microscopy. In the albino rat, the TRN situated in the ventral paramedian midbrain and pontine reticular formation, contains two principal types of neurons. The first is a population of large multipolar neurons (40–80 μm diameter) with abundant Nissl substance and 4–7 smooth dendrites which may extend up to 500 μm in length. The second is medium-sized fusiform neurons (14–40 μm diameter) with less Nissl substance and two primary dendrites that originate from each pole of the soma and have a more closely ramifying dendritic field. Fluorescence histochemistry demonstrates that serotonin neurons constitute one component of the medium-sized neuron group. A third neuronal type, infrequently encountered at the outer margins of the nucleus, corresponds to the large, multipolar isodendritic neurons (soma diameter 40–80 μm) of the pontine reticular formation. Ultrastructural analysis of the TRN also demonstrates large and medium sized neurons which are present, together with numerous large dendritic trunks, between bundles of myelinated axons traversing the TRN in both rostrocaudal and transverse planes. This distinctive arrangement produces the appearance of “gray islands” between myelinated axon bundles. Within these areas, abundant synaptic terminals occupy a large proportion of the available terminal space on the surface of dendrites and perikarya, particularly of the large type of neuron. Two types of synaptic terminals are encountered; S-type synapses contain lucent spherical synaptic vesicles and F-type synapses contain flattened lucent vesicles. In addition there is a small number of synaptic terminals with scattered 100–120 nm diameter dense core vesicles in a population of smaller pleomorphic vesicles. These account for no more than 10% of the synaptic terminal population.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236166
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  • 240
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    Histophysiological studies on the corpus allatum of Leucophaea maderae (1978)
    Springer
    Cell & tissue research 194 (1978), S. 533-545 
    Details
    ISSN: 1432-0878
    Keywords: Corpus allatum ; Insects ; Ovariectomy ; Ultrastructure ; Cytophysiology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the corpora allata of 29 Leucophaea ovariectomized in the nymphal stage and maintained up to an adult age of 28 months was examined. In general, the subcellular morphology of these glands has much in common with that of normal female controls examined at the height of their activity. In addition, the most “typical”of the gonadectomy cases show certain distinctive features that are either absent or much less prominent in unoperated controls. Of primary interest is the striking abundance of smooth surfaced endoplasmic reticulum observed in many but not all of the castrates. Since this organelle is implicated in the biosynthesis of juvenile hormone, the factor normally responsible for yolk deposition, its increase, together with certain additional ultrastructural features, is indicative of an exceptionally high rate of hormone production. An explanation for the putative hyperactivity displayed to various degrees by the experimental animals may well be the constancy of the demand on their corpora allata, since removal of the ovaries abolishes the afferent signals in response to which, in the intact female, the brain turns off these glands during the long periods of gestation. That the synthetic effort may eventually level off, even in the absence of regular inhibitory stimuli, is suggested by the corpora allata of those castrates, the ultrastructure of which reflects moderate activity or possibly further regression
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236172
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  • 241
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    The eyes of mesopelagic crustaceans (1978)
    Springer
    Cell & tissue research 195 (1978), S. 59-79 
    Details
    ISSN: 1432-0878
    Keywords: Compound eyes ; Arthropod vision ; Deep-sea crustaceans ; Ultrastructure ; Thysanopoda tricuspidata (Euphausiacea)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The compound eyes of the mesopelagic euphausiid Thysanopoda tricuspidata were investigated by light-, scanning-, and transmission electron microscopy. The eyes are spherical and have a diameter that corresponds to 1/6 of the carapace length. The hexagonal facets have strongly curved outer surfaces. Although there are four crystalline cone cells, only two participate in the formation of the cone, which is 90–120 μm long and appears to have a radial gradient of refractive index. The clear zone, separating dioptric structures and retinula, is only 90–120 μm wide. In it lie the very large oval nuclei of the seven retinula cells. Directly in front of the 70 μm long and 15 μm thick rhabdom a lens-like structure of 12 μm diameter is developed. This structure, known in only a very few arthropods, seems to be present in all species of Euphausiacea studied to date. It is believed that the rhabdom lens improves near-field vision and absolute light sensitivity. Rod-shaped pigment grains and mitochondria of the tubular type are found in the plasma of retinula cells. The position of the proximal screening pigment as well as the microvillar organization in the rhadbdom are indicative of light-adapted material. The orthogonal alignment of rhabdovilli suggests polarization sensitivity. Behind each rhabdom there is a cup-shaped homogeneous structure of unknown, but possibly optical function. Finally, the structure and the function of the euphysiid eye are reviewed and the functional implications of individual components are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00233677
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  • 242
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    Changes in structure of ventral epidermis of Rana ridibunda during metamorphosis (1978)
    Springer
    Cell & tissue research 195 (1978), S. 111-122 
    Details
    ISSN: 1432-0878
    Keywords: Epidermis ; Skin ; Ultrastructure ; Rana ; Metamorphosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The organisation of the ventral epidermis organisation was followed throughout ontogenesis in Rana ridibunda. Epidermis of tadpoles with 2–3 limbs was organised into two layers: a stratum germinativum consisting of elongated columnar cells, and an outer stratum corneum consisting of two types of cuboid cells. Two types of cells can be distinguished; they are a light (clear) cell and a dark (dense) cell. In the 4-legged tadpoles the stratum corneum cells start to flatten and a replacement layer appeared underneath. A well-defined stratum germinativum is found and within it, epidermal glands. Moulting took place for the first time in tadpoles just before metamorphosis, and a well-organised stratum granulosum was formed still containing the two main types of epidermal glands. The flask cells appear in the juveniles for the first time, greatly increasing in numbers in the adult epidermis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00233680
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  • 243
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    Ultrastructure of the extracutaneous pigment cells in the plaice (Pleuronectes platessa, L., Teleostei) (1978)
    Springer
    Cell & tissue research 195 (1978), S. 123-144 
    Details
    ISSN: 1432-0878
    Keywords: Pigment cells, extracutaneous ; Melanocytes ; Guanocytes ; Ultrastructure ; Plaice (Teleost)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The extracutaneous pigment cell system of the plaice (Pleuronectes platessa L.) was examined by light and electron microscopy in selected regions, including two cutaneous regions for comparison. The extracutaneous pigmentation consists of guanocytes and melanocytes with differing distributions within the body. The eyeless side lacks melanocytes. The pigment cells are differentiated as very flat elements with long processes. They display an affinity for loose connective tissue at boundary layers such as the peritoneal epithelium, organ capsules or blood vessels, to which they are parallelly arranged at a very constant distance. In some locations guanocytes are intimately associated with melanocytes forming “reduced chromatophore units”. Extracutaneous pigment cells are poor in mitochondria, endoplasmic reticulum, microfilaments, caveolae intracellulares, ribosomes and glycogen granules, all of which are more abundant in cutaneous pigment cells and pigment cells of the eye. In extracutaneous guanocytes the crystals are loosely arranged parallel to the cell surface, in cutaneous guanocytes perpendicular. Cells with rod-like vesicular cisternae are described as “guanoblasts”. No single pigment cell was found exhibiting different types of pigment granules. The varying colors of extracutaneous pigmentation arise from varying combinations of guanocytes and melanocytes in addition to the color of the tissue itself.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00233681
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  • 244
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    Ultrastructure of the ultimobranchial follicles of the laying chicken (1978)
    Springer
    Cell & tissue research 195 (1978), S. 309-316 
    Details
    ISSN: 1432-0878
    Keywords: Ultimobranchial gland ; Birds ; Follicular cell types ; Ultrastructure ; Secretion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultimobranchial gland of the laying chicken consists of groups of C cells interspersed among a collection of intercommunicating follicles and ducts of variable size and shape. The epithelium lining this system ranges from squamous to columnar and includes stratified squamous and pseudostratified columnar elements. Four cell types are distinguished in this epithelium: F, mucous, C, and basal cells. F cells show microvilli and microfilaments. Pinocytotic activity and images of fusion of coated vesicles with the plasma membrane are evident. The rough-surfaced endoplasmic reticulum (RER) and the Golgi complex are moderately developed. Dense bodies are encountered apically in some cells. Mucous cells possess microvilli and secretory material in the typical form of partially fused droplets. C cells contain secretory granules and are invariably separated from the follicular lumen by other cell types. The smaller, pyramidal basal cells contain filaments, RER, small Golgi complexes, free ribosomes and hemidesmosomes. The lumina contain flocculent or granular material, cellular debris and desquamated cells. Morphological evidence demonstrates that features of the pharyngeal epithelium are retained and that the majority of the cell types, with the exception of C cells, are presumably nonendocrine.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236727
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  • 245
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    Effects of acute cold exposure on the ultrastructure of the mouse pinealocyte (1978)
    Springer
    Cell & tissue research 195 (1978), S. 461-469 
    Details
    ISSN: 1432-0878
    Keywords: Pineal gland ; Cold ; Ultrastructure ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ultrastructural changes in pinealocytes were investigated qualitatively and quantitatively in mice exposed to low temperatures at 0° C or 5° C for 30 or 60 min. A quantitative estimation of the granulated vesicles of about 100 nm diameter in pinealocytes demonstrated that the number of these vesicles per pinealocyte in mice exposed to cold at 0° C or 5° C increased remarkably as compared with that of the controls. This finding indicates that cold stimuli may activate the formation of the granulated vesicles in pinealocytes. In mice exposed to cold at 0° C for 60 min, granulated vesicles were often found in groups close to the plasma membrane of the pinealocyte cell bodies or processes, indicating the release of the vesicle content into the extracellular spaces. Additionally, the pinealocytes of the mice exposed to cold at 0° C for 60 min were characterized by the frequent occurrence of lysosome-like bodies and filaments. The development of these structures in response to severe cold may represent a depressed functional state of pinealocytes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00233889
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  • 246
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    Fine structure of the pineal organ in the troglobytic fish, Typhlichthyes subterraneous (Pisces: Amblyopsidae) (1978)
    Springer
    Cell & tissue research 195 (1978), S. 535-545 
    Details
    ISSN: 1432-0878
    Keywords: Pineal organ ; Troglobytic fish, Typhlichthyes subterraneous ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The pineal organ of the blind, cave-dwelling fish, Typhlichthyes subterraneous, was examined with both light and electron microscopes. Like the eyes, the pineal in this troglobytic species was found to be regressed. Two cell types, photoreceptor and supportive cells, were described in the pineal epithelium. Although ganglion cells were not identified, small, unmyelinated nerve fibers were present. The photoreceptor cells had degenerated outer segments. Accordingly, it was suggested that the pineal in this species is not likely to function in photoreception. However, the presence of well developed Golgi bodies, clear and dense-cored vesicles, variable amounts of rough endoplasmic reticulum and glycogen particles indicated that both cell types are metabolically active and may play a role in secretion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00233895
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  • 247
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    Ultrastructure of rat pinealocytes in vitro: Influence of gonadotropic hormones and LH-RH (1978)
    Springer
    Cell & tissue research 195 (1978), S. 547-556 
    Details
    ISSN: 1432-0878
    Keywords: Pineal organ, rat ; Ultrastructure ; Organ culture ; Gonadotropic hormones ; LH-RH
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The influence of gonadotropic hormones on the ultrastructure of rat pinealocytes in short-term organ culture was studied. Human chorionic gonadotropin (HCG), as well as pregnant mare serum gonadotropin (PMSG), caused a marked activation of pinealocytes. An hypothesis is discussed implying the presence of a feedback mechanism between the pineal organ and the hypothalamo-hypophysial system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00233896
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  • 248
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    Ultrastructure and segmentation of microdissected kidney tubules in the marine flounder, Pleuronectes platessa (1978)
    Springer
    Cell & tissue research 190 (1978), S. 27-45 
    Details
    ISSN: 1432-0878
    Keywords: Kidney tubules (proximal) ; Teleost (Pleuronectes platessa) ; Lanthanum ; Microinjections ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A new method combining electron microscopy with microdissection was used to study the segmental variation along the tubule of a marine flounder. Two different nephron types were present. One type had long tubules with the glomeruli located close to the kidney surface. The other type had shorter and more coiled tubules with the glomeruli located close to the terminal end of the same nephron. Five different segments were present: (1) neck segment, (2) first proximal segment, (3) second proximal segment, (4) third proximal segment, and (5) collecting tubule. The third proximal segment was not present in all tubules. An extensive system of infoldings from the plasma membrane was present in all segments, except the neck segment and the collecting tubule. Tight junctions impermeable to lanthanum were present in all segments. The collecting duct cells also had extensive infoldings from the plasma membrane and tight junctions impermeable to lanthanum were also present here.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00210034
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  • 249
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    Ultrastructural observations on the hypothalamo-posthypophysial complex of the Brattleboro rat (1978)
    Springer
    Cell & tissue research 191 (1978), S. 267-286 
    Details
    ISSN: 1432-0878
    Keywords: Neurohypophysis ; Supraoptic nucleus ; Paraventricular nucleus ; Ultrastructure ; Brattleboro rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The hypothalamo-posthypophysial complex of the homozygous Brattleboro rat is characterized by a hyperactivity of its neurons. The neurosecretory fibers, especially in the neurohypophysis, show numerous signs of autophagy and tubular proliferation of the axoplasmic reticulum. These structural alterations, as well as the nematosomes or nucleolus-like bodies encountered in the perikarya, may be related to the chronic hyperactivity of the neurons. They can be reduced by administration of exogenous vasopressin. The numerous liposomes in the pituicytes are paralleled in the neuronal perikarya by a great number of lysosomes. Small dense core vesicles observed in the neurosecretory endings and perikarya may indicate a secretory product distinct from oxytocin and vasopressin. In the homozygous Brattleboro rat, endings of the aminergic type are more numerous than in the normal rat. With respect to the role they may play in the secretory processes, their increase might be secondary to the vasopressin deficiency.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00222424
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  • 250
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    Ultrastructural and morphometric study of the lung of the European salamander, Salamandra salamandra L. (1978)
    Springer
    Cell & tissue research 191 (1978), S. 343-356 
    Details
    ISSN: 1432-0878
    Keywords: Lung ; Amphibia ; Ultrastructure ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ultrastructural and morphometric investigations were performed on the lung of the European salamander, Salamandra salamandra L. Folds of first and second order are covered with a ciliated epithelium containing goblet cells. The respiratory surface of the lung is lined by a single type of cell which, in amphibians, combines features of type I and type II alveolar cells of the mammalian lung. In the salamander the respiratory and ciliated epithelial cells as well as goblet cells possess electron dense and lucent vesicles in their cytoplasm as well as lamellar bodies. A small amount of surfactant, composed most probably of phospholipids and mucopolysaccharides, was observed covering the entire inner surface of the lung. Morphometric methods were used to determine the dimensions of the perinuclear region of pneumocytes, the thickness of the air-blood barrier and lung wall, and also the diameter of capillaries. The thickness of the respiratory air-blood barrier was found to be considerably higher than that of the corresponding barrier in mammals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00222429
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  • 251
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    Fine structure of degenerating abdominal motor neurons after eclosion in the sphingid moth, Manduca sexta (1978)
    Springer
    Cell & tissue research 191 (1978), S. 317-331 
    Details
    ISSN: 1432-0878
    Keywords: Programmed cell death ; Motor neurons ; Neuro-glial interaction ; Ultrastructure ; Manduca (Lepidoptera)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ultrastructural aspects of the natural degeneration of a group of six motor neurons in the fourth abdominal ganglion of Manduca sexta are described. These motor neurons innervate intersegmental muscles that degenerate and disappear immediately after adult eclosion. The first detectable changes in the cell bodies appear 12 h after eclosion and include disruption of the endoplasmic reticulum and an increase in the size and number of lamellar bodies. At 32 h the nuclear membranes rupture, and the membranous and granular cytoorganelles segregate in different parts of the cell. At that stage the surrounding glial cells participate in the digestion of material from the degenerating neurons. From 72 h onward the remaining neuronal structures become disrupted, and are finally transformed into a single, large lamellar body (residual body) within the glial profile. The degeneration pattern differs significantly from that of embryonic vertebrate neurons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00222427
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  • 252
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    Nonconventional innervation of the pancreatic islets of the teleost fish, Gillichthys mirabilis (1978)
    Springer
    Cell & tissue research 191 (1978), S. 305-315 
    Details
    ISSN: 1432-0878
    Keywords: Innervation ; Pancreatic islets ; Teleosts ; Axonal iontophoresis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The innervation of the pancreatic islets of a teleost fish, Gillichthys mirabilis, was investigated with various techniques including axonal iontophoresis of cobalt, light microscopy, and electron microscopy. Two types of postganglionic neurons, the splanchnic and the vagus, innervate the islet parenchyma. The splanchnic fibers originate from the single coeliac ganglion, situated near the third spinal nerve on the right side, and pass caudally to the islet. Postganglionic vagal fibers reaching the islets arise from ganglion cells located at irregular intervals along the vagus nerve. Iontophoresis of cobaltous chloride revealed that both types of nerves send large numbers of fibers to the islet cells. Electron microscopy showed that the granules of the vagal fibers are polymorphic, large (130 mm diameter) and markedly electron dense, whereas the splanchnic granules are smaller (100 nm diameter) and less electron dense than those of the vagus. These granules do not correspond to those seen in postganglionic autonomic neurons of other vertebrates. Rather, they are more like classical neurosecretory granules. Although their chemical nature is unknown, the extent of islet innervation suggests that it must play an important regulatory role.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00222426
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  • 253
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    The influence of activation, removal or denervation of the pineal on the fine structure of the Leydig cell and seminal vesicle epithelium in golden hamsters (1978)
    Springer
    Cell & tissue research 191 (1978), S. 367-378 
    Details
    ISSN: 1432-0878
    Keywords: Leydig cells ; Seminal vesicle ; Pineal gland ; Golden hamster ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Fine structural changes of testicular interstitial cells of Leydig and secretory cells of seminal vesicles were studied in golden hamsters under different functional states of the pineal gland. Experiments were performed in the reproductive season (summer months). In the hamsters blinded for 8 weeks the testes and the seminal vesicles were markedly atrophic, and the Leydig cells and the secretory cells of seminal vesicles were extremely involuted. By contrast, both types of cells in the pinealectomized or superior cervical ganglionectomized hamsters exhibited cytological features suggestive of an enhanced secretory activity. This study shows that functional activity of Leydig cells as well as secretory cells of seminal vesicles in the hamster may be depressed or augmented by stimulating or inhibiting the pineal antigonadal function, respectively, without performing hypophysectomy or hormonal administration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219802
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  • 254
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    Surface fine structure of the subfornical organ in the Japanese quail, Coturnix coturnix japonica (1978)
    Springer
    Cell & tissue research 191 (1978), S. 389-404 
    Details
    ISSN: 1432-0878
    Keywords: Subfornical organ ; Japanese quail, Coturnix coturnix japonica ; Ultrastructure ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The surface ultrastructure of the subfornical organ (SFO) was investigated in the Japanese quail. The SFO consists of a body and a stalk. The body of the SFO can be divided into rostral and caudal parts. On the rostral part, each ependymal cell possesses a short central solitary cilium; clustered cilia are also occasionally seen. Microvilli are abundant. On the caudal part, cells with a solitary cilium are fewer in number, and clustered cilia are rarely found. Microvilli are not as abundant as on the rostral part. In addition, large bulbous protrusions, tufts of small protrusions, deep funnel-shaped hollows, small pinocytotic invaginations and possible cerebrospinal fluid-contacting axons are sporadically observed on the surface of various regions of the body. Each ependymal cell of the stalk has a wide apical surface. A central solitary cilium, microvilli and other structures are observed more rarely on the stalk than on the body, while clustered cilia are not seen on the stalk. These structures are compared with those of the mammalian SFO and further discussed in relation to the possible dipsogenic receptor function for angiotensin II.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219804
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  • 255
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    Histochemical and ultrastructural effects of Enovid E on the endometrium of the baboon (1978)
    Springer
    Cell & tissue research 192 (1978), S. 451-460 
    Details
    ISSN: 1432-0878
    Keywords: Endometrium ; Baboon ; Oral contraceptive ; Histochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Endometrium from a group of baboons treated with the oral contraceptive, Enovid E, was studied histologically, histochemically and ultrastructurally, and compared to endometrium from normally cycling animals. All endometria were obtained by transcervical uterine biopsy between 10 and 14 days of the treatment cycle or the normal menstrual cycle. Histologically, no discernible differences between the control and experimental endometria were apparent. While observable differences were not evident between the endometrial alkaline phosphatase and succinate dehydrogenase activities of control and experimental animals, there was an increased acid phosphatase activity in the Enovid E-treated baboon endometrium. Ultra-structurally, the glandular cells of treated animals appeared to be more physiologically advanced than did those from the control endometria. These advances were evident from the prominent Golgi complex, increased development of the endoplasmic reticulum and increases in the size, number and complexity of mitochondria. The functional correlates of these morphological and histochemical observations are discussed and compared to human endometrial studies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00212325
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  • 256
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    Evidence for the zonation of interrenal tissue in the adrenal gland of the duck (Anas platyrhynchos) (1978)
    Springer
    Cell & tissue research 192 (1978), S. 363-379 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal glands ; Birds ; Ultrastructure ; Corticosterone ; Zonation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Although interrenal tissue from the intact duck does not show a clear zonation when examined by light microscopy, the tissue does develop a well defined zonation following exposure to high and low levels of corticotropic stimulation. Under these conditions clear ultrastructural differences are seen between cells of the subcapsular zone (SCZ) and the inner zone (IZ). Based on these observations, the ultrastructure of tissue from intact birds was examined retrospectively and in addition, cell sizes and the relative volumes and areas of intracellular components were measured morphometrically. These analyses reveal morphological and quantitative differences between cells from the IZ and the SCZ. Cells of the IZ have small rounded nuclei, extensive smooth endoplasmic reticulum (SER) and mitochondria with tubular cristae, whereas cells from the SCZ contain pleomorphic nuclei, less SER and mitochondria with shelf-like cristae. The mean cell volume in the IZ is significantly less than that in the SCZ. In the SCZ cells the volume densities (volume per unit volume cytoplasm) of mitochondria and lipid droplets and the surface densities (area per unit volume cytoplasm) of the outer mitochondrial membranes are significantly greater than those in IZ cells. Conversely, in the cells of the IZ the volume densities of the nuclei and dense bodies and the surface density of the SER are greater than the corresponding values estimated for the cells of the SCZ. Although the mitochondria comprise a smaller fraction of the mean volume of IZ cells than SCZ cells, the total surface area of the cristae is approximately the same in the cells of both zones.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00212319
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  • 257
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    Ultrastructural and morphometric aspects of the juxtaglomerular apparatus in the monkey kidney (1978)
    Springer
    Cell & tissue research 192 (1978), S. 503-512 
    Details
    ISSN: 1432-0878
    Keywords: Juxtaglomerular apparatus ; Monkey (Cebus apella) ; Ultrastructure ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The authors describe the ultrastructure of the juxtaglomerular apparatus in five adult male Cebus apella monkeys and communicate morphometric data of the macula densa. In comparison with several species of rodents examined before, the macula cells of the monkey contain many more mitochondria and possess a particularly thick basal membrane. The relative volume of the nuclei is slightly smaller than in rodents. The Goormaghtigh cells of the monkey resemble those of the other animals investigated. The epithelioid (or juxtaglomerular) cells do not contain secretory granules. This observation reminds one of the behavior of the epithelioid cells of guinea pigs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00212329
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  • 258
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    The epidermis and sensory organs of Dugesia tigrina (Turbellaria: Tricladida) (1978)
    Springer
    Cell & tissue research 193 (1978), S. 35-40 
    Details
    ISSN: 1432-0878
    Keywords: Planarian ; Scanning electron microscopy ; Epidermis ; Sense organs ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The epidermis of D. tigrina was examined using the scanning electron microscope. Both dorsal and ventral surfaces are extremely irregular in contour, as well as being permeated by large numbers of pores. Cilia are restricted to the ventral surface, the auricles and that part of the dorsum adjacent to the auricles. Club-shaped receptors, as well as cilia, were seen in the auricles. The epidermis anteriad to the eyespots is indistinguishable from that covering the remainder of the dorsal surface. Light rays could not enter the eyespot through this rough epidermal surface without becoming diffracted in an irregular fashion. It was therefore concluded that visual image perception is not a function of the planarian eyespot.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00221599
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  • 259
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    Development of the calyx and lateral oviduct during oogenesis in Aedes aegypti (1978)
    Springer
    Cell & tissue research 193 (1978), S. 125-137 
    Details
    ISSN: 1432-0878
    Keywords: Insect-reproduction ; Ovary ; Oviduct ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The lateral oviduct and calyx of nulliparous Aedes aegypti on a sucrose diet are both flattened sacs, lacking a well defined lumen. Both are formed of an inner epithelial and an outer muscular layer, each one cell thick. The lateral oviduct is surrounded by a circular muscle sheath which is continuous with the ovarian sheath. Each ovariolar sheath is continuous with the outer layer of the calyx. The structure of both the lateral oviduct and the calyx is greatly modified after the initial blood meal. A distinct lumen develops; there is an extensive development of the outer muscular layers, and the inner epithelial layers become invaginated forming deep crypts lined with extensive microvilli. The follicular stem, which joins the primary follicle to the calyx in each ovariole, is not hollow and does not mark the opening into the calyx through which the mature egg can pass. The eggs gain access to the oviductal system after the calyx extends around the follicular epithelium of the primary follicle, when breaks appear in the calyx wall opposed to the follicular epithelium, until the mature eggs, eventually lie in a highly distended thin-walled sac of calyx from which they have direct and easy access to the lateral oviduct. After oviposition, this sac contracts to occupy once more a compact axial position in the ovary. Remnants of the follicular epithelium, containing many lysosomes are attached to the calyx at this time.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00221606
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  • 260
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    Ultrastructure of the cells of the ovarian interstitial gland in hypophysectomized rats (1978)
    Springer
    Cell & tissue research 193 (1978), S. 433-442 
    Details
    ISSN: 1432-0878
    Keywords: Hypophysectomy ; Interstitial gland ; Ultrastructure ; Innervation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of the interstitial gland of the ovary was studied in hypophysectomized rats and in hypophysectomized rats after denervation of the ovary or stimulation of the ovarian plexus. Hypophysectomized rats were used to eliminate gonadotropic influences on interstitial cells. In hypophysectomized rats, there was a large amount of intercellular space and cells had irregularly shaped nuclei and a large nuclear-cytoplasmic ratio. Prominent cytoplasmic features included small mitochondria with an electron-dense matrix, rough and smooth endoplasmic reticulum, polysomes and large osmiophilic lipid droplets. Interstitial cells from stimulated ovaries had reduced intercellular space and a reduced nuclear-cytoplasmic ratio. Mitochondria had tubular cristae; smooth endoplasmic reticulum-surrounded lipid droplets, and large polysomes were present. After section of the ovarian plexus, intercellular space was increased and filopodia were numerous. Cytoplasmic features included mitochondria with a dense matrix and indistinct cristae, large electronlucent lipid droplets, and variously sized multivesicular structures. These observations suggest that stimulation of the ovarian plexus in hypophysectomized rats causes regressed cells to assume the fine structural features of active steroidogenic cells. In contrast, interruption of the ovarian nerve supply causes a qualitative and quantitative increase in ultrastructural features characteristic of regressed steroidogenic cells. These responses of interstitial gland cells to denervation and stimulation provide morphological evidence for a functional role for the adrenergic nerves to this ovarian compartment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225341
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  • 261
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    Macrophages, a normal component in seasonally involuting testes of the swan, Cygnus olor (1978)
    Springer
    Cell & tissue research 193 (1978), S. 463-471 
    Details
    ISSN: 1432-0878
    Keywords: Macrophages ; Ultrastructure ; Testicular involution ; Swan, Cygnus olor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the swan, Cygnus olor, spermatogenesis shows a pronounced seasonal cycle. During the long involution phase a transient invasion of macrophages into the seminiferous tubules regularly takes place at the height of regression prior to total rest. These macrophages are involved in the additional disposal of supernumerary and degenerating premature germ cells, at a time when the Sertoli cells are already filled with phagolysosomes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225344
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  • 262
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    Intranuclear inclusions in the developing neurons of the rat cuneate nuclei (1978)
    Springer
    Cell & tissue research 193 (1978), S. 525-532 
    Details
    ISSN: 1432-0878
    Keywords: Intranuclear inclusions ; Neurons ; Development ; Ultrastructure ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of intranuclear rodlets, microtubules, fibrillar lattices and membranous inclusions found in the developing cuneate nuclei of rats is described. Rodlets, ranging in diameter from 96–312 nm and in length from 1–2 μm, are made up of tightly packed straight filaments measuring 5–8 nm in diameter. Microtubules with a diameter of 26 nm are clustered together. Fibrillar lattices are made up of fibrils with a diameter of 9 nm arranged in layers or sets. Two to nine sets make up a lattice, with a maximum width of 68 nm, in which the adjacent sets are arranged at an angle to each other. Rodlets and fibrillar lattices occur in 6.8% of the neurons. Membranous inclusions, reported here for the first time in normal neurons, are of 2 types: small vesicles of 0.1–0.6 μm and large vacuoles measuring 1–2 μm. Both types are bounded by either a single or a double membrane and generally have an electron lucent content. Membranous inclusions occur in 25.3 % of the neurons. Changes in the frequency of occurrence of the various intranuclear inclusions in the course of postnatal development are also reported.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225348
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  • 263
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    Synapses of optic nerve afferents in the rat suprachiasmatic nucleus (1978)
    Springer
    Cell & tissue research 194 (1978), S. 17-35 
    Details
    ISSN: 1432-0878
    Keywords: Synapses ; Optic nerve ; Suprachiasmatic nucleus ; Ultrastructure ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Synapses of optic nerve afferents (optic synapses) in the rat suprachiasmatic nucleus (SCN) have been identified ultrastructurally. They are easily distinguished from other types of synapses. The optic boutons are characterized by the presence of large mitochondria with a swollen electron lucent matrix and an interconnected tubular system formed by their inner membrane. Other, more variable features include: 1) a scattered pattern of synaptic vesicles which are found throughout the entire presynaptic element with relatively little accumulation near the active zones; 2) the occurrence of dense core vesicles and glycogen granules; 3) the active zones, the majority of which is Gray-type I, but a minority can obviously be classified as Gray's type II; 4) the innervation of smaller peripheral dendrites and dendritic spines. Boutons of this kind are exclusively filled with anterogradely transported horseradish peroxidase injected into both eyes. Very few neuronal elements containing the typical mitochondria have been observed in the SCN on the 6th day post partum, increasingly more on the 9th and 12th day, but considerably higher numbers after opening of the eyes on the 17th and the following days. The location of normal and degenerating optic boutons was examined light- and electron microscopically. In the rostral third of the SCN there are relatively few optic synapses which are found close to the optic chiasma. In the middle portion of the SCN optic synapses increase in number; they are found not only in the ventral part of the nucleus but also in lateral regions. This becomes particularly obvious in the caudal third of the SCN.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00209231
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    Unusual aggregations of tubules associated with endoplasmic reticulum in digestive cells of Alderia modesta (Mollusca: Gastropoda: Sacoglossa) (1978)
    Springer
    Cell & tissue research 194 (1978), S. 179-182 
    Details
    ISSN: 1432-0878
    Keywords: Tubule aggregations ; Granular endoplasmic reticulum ; Gastropoda ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Aggregations of cylindriform tubules closely packed in a hexagonal arrangement and associated with the rough-surfaced endoplasmic reticulum (RER) are described in cells of the digestive gland of a sacoglossan gastropod. Each tubule is approximately 61 nm in outer diameter and the central lumen is lined with a layer of finely granular material. The tubule wall is composed of approximately 22 dense subunits. Adjacent tubules are associated with a pair of indistinct granules. Membranes of the RER frequently join the aggregations. The lumen of a tubule may be continuous either with the intracisternal space of the RER or with the cytoplasmic matrix of the cell. It is suggested that the aggregations of tubules are elaborations of the endoplasmic reticulum.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00209244
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  • 265
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    The ultrastructure of campaniform sensilla on the eye of the cricket, Gryllus campestris (1978)
    Springer
    Cell & tissue research 195 (1978), S. 349-357 
    Details
    ISSN: 1432-0878
    Keywords: Campaniform sensilla ; Mechanoreceptors ; Ultrastructure ; Compound eye ; Cricket
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The structure of the campaniform sensilla of the cricket eye was investigated by light and electron microscopy. Each sensillum is innervated by a single bipolar neuron. Its axon extends through the retina into a side-branch of the nervus tegumentarius. The dendrite extends through a cuticular channel to the surface of the cornea. The distal part of the dendrite, the sensory process, contains a tubular body and is attached to a cuticular cap which is obliquely inserted into the exocuticle between the corneal lenslets. Some particular structural features as well as the function of the campaniform sensillum of the cricket eye are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236731
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  • 266
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    Morphologic alterations in the epithelium of the human oviduct induced by a low dosis gestagen (1977)
    Springer
    Archives of gynecology and obstetrics 223 (1977), S. 269-281 
    Details
    ISSN: 1432-0711
    Keywords: Oviduct ; Gestagen ; Contraception ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Morphological alterations in the epithelium of the human oviduct related to continuous administration of low dosage lynestrenol were studied in 10 women by electron microscopy. The effect of lynestrenol on the morphology of the tubal epithelium was shown to be time dependent. First the discharge of secretory products from the non-ciliated cells was inhibited. Secondary to this the synthetic activities of the cells were drastically decreased. This inactivation of the tubal epithelium reached its maximum after 6 months. At this time the epithelial cells, particularly the non-ciliated cells were almost devoid of organelles and had an electron transparent cytoplasm. In addition to the action of lynestrenol on the secretory and synthetic activities of the cells a strong ciliogenetic effect could be observed after about 3 months of lynestrenol administration. The ratio of ciliated to non-ciliated cells changed from 1∶1 at the beginning of the treatment to 2.9∶1 after 6 months. This ratio was then maintained and could still be found in patients who had used lynestrenol for 25 and 39 months. In contrast to the persistent effect of lynestrenol on the ciliary apparatus of the cells the synthetic activities and the secretory mechanism were partially restored with long standing use. The importance of the observed changes and their possible participation in the contraceptive action of lynestrenol are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00667367
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    Die Dezidualisation der endometrialen Stromazelle (1977)
    Springer
    Archives of gynecology and obstetrics 223 (1977), S. 19-31 
    Details
    ISSN: 1432-0711
    Keywords: Stromal reticulum cell ; Decidua ; Ultrastructure ; Stroma-Retikulumzelle ; Deziduale Umwandlung ; Feinstruktur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung In der vorliegenden Arbeit werden die feinstrukturellen Veränderungen der endometrialen Stroma-Retikulumzelle über die prädeziduale Reaktion der späten Sekretionsphase bis hin zur ausdifferenzierten Deziduazelle beschrieben. Bei der dezidualen Umwandlung der Retikulumzellen ändern sich Zellvolumen, Organellensortiment und zwischenzellige Beziehungen. Die Veränderungen sind Ausdruck eines adaptativen Funktionswandels der Zellen. Im Gegensatz zur kontinuierlichen Transformation der Feinstruktur zeigt das zytochemische Verhalten eine in Schüben ablaufende Entwicklung, da die neugewonnenen Enzymmuster jeweils erst nach der funktionellen Reifung ihrer Arbeitsstrukturen erfaßt werden können. Zu den wichtigsten zellspezifischen Leistungen der Deziduazelle und ihrer Vorstadien gehören sekretorische und intermediäre endokrine Aufgaben. Als spezifisches Sekretionsprodukt der Stroma-Retikulum- und Deziduazelle lassen sich präkollagene Fibrillen nachweisen. Für eine Beteiligung der Deziduazelle am Steroidmetabolismus sprechen charakteristische Organellenveränderungen, die im zeitlichen Zusammenhang mit Steroiddehydrogenaseaktivitäten auftreten. Ein auffallender Befund der postovulatorischen Retikulumzelle und der voll entwickelten Dezidua sind spezielle Differenzierungen des Karyoplasma (Karyosome). Äahnliche nukleäre Differenzierungen sind auch von anderen Zellen hormonsensitiver Gewebe bekannt. Sie könnten als sichtbare Manifestation der am genetischen Apparat des Kernes angreifenden Steroidhormonwirkung gedeutet werden.
    Notes: Summary The fine structural changes of the endometrial stromal cell from late secretory phase up to full developed decidua cell have been investigated by means of electron microscope. During decidual transformation the cell volume, the assortment of cytoplasmic organelles and the mode of intercellular attachments undergo characteristic alterations. These alterations reflect an adaptation on new cellular functions. In contrast to the structural organization, which is transformed continuously, the encymatic cell pattern exerts a step wise gradual transformation, since new encymatic capacities can only arise after their functional structures have been established. To the most important functions of decidua cells and their prestages belong secretory and endocrine activities. Precollagen fibrills represent a specific secretory product of the stroma reticulum cells. The active involvement of the full differentiated decidua cells in steroid metabolism is indicated by characteristic transformations of the cytoplasmic organization concomittantly to the appearance of intracellular steroid dehydrogenase activities. So-called karyosoma could be demonstrated within the nuclei of postovulatory stromal reticulum cells as in decidua cells. Similar nuclear differentiations have been observed in various target cells of steroid hormones. They possibly are structural manifestations of the hormonal interaction with the nuclear DNA.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00675080
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    Ultrastructural and microanalytical aspects of developing osteodentin in rat incisors (1977)
    Springer
    Calcified tissue international 24 (1977), S. 215-222 
    Details
    ISSN: 1432-0827
    Keywords: Mineralization ; Osteodentin ; Intracellular ; Ultrastructure ; Microanalysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Newly formed osteodentin obtained from the anterior extremities of fetal or young rat incisors was observed by means of electron microscopy and electron probe X-ray microanalysis. Cells related to osteodentin formation frequently showed membrane bound intracellular bodies containing varying amounts of fine, needle-shaped crystals, which were identified as apatite. The intracellular clusters of apatite crystals were extruded from the cells through membrane fusion or cellular degeneration. These extracellular clusters seemed to be gradually incorporated into the mineralizing collagenous matrix, which developed around them. Frequent occurrence of dense, dotshaped or filamentous profiles suggested that the dense bodies seen in the perinuclear regions or in the Golgi area were the sites of crystal formation. Energy dispersive X-ray point analysis showed that the intracellular or extracellular apatite clusters contained sulfur in a concentration higher than was present in the mineralizing collagenous matrix. Furthermore, wave dispersive X-ray line analysis showed that the concentration of sulfur was higher in the osteodentin matrix than in the dentin matrix. The sulfur detected is presumed to be contained in acid mucopolysaccharides, which were distributed more heavily in the osteodentin matrix than in the dentin matrix. On the basis of these data, it was concluded that the unique chemical and structural characteristics of the osteodentin result primarily from the incorporation of apatite clusters of intracellular origin and associated acid mucopolysaccharides.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02223319
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  • 269
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    Ultrastructural responses of the hypoglossal nucleus to the presence in the tongue of botulinum toxin, a quantitative study (1977)
    Springer
    Experimental brain research 30 (1977), S. 313-321 
    Details
    ISSN: 1432-1106
    Keywords: Rat ; Hypoglossal nucleus ; Botulinum toxin ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructural effects of local injection of botulinum toxin into the left half of the tongue of the rat, were studied quantitatively 35 days postoperatively in the left hypoglossal nucleus. The results showed (1) a decrease in somatic and neuropil bouton numbers because of loss of boutons with symmetrical synapses and clear spherical synaptic vesicles, (2) a decrease in the numbers of dendrite profiles in the neuropil, (3) an increase in the proportion of dendrites and boutons with unusual inclusions, suggestive of profile retraction, (4) an increase in the proportion of profiles which were unusually electron-dense, (5) an increase in the amount of astrocyte, and a growth of astrocyte sheaths around bouton-free neurone surfaces, (6) the presence of occasional microglia, and (7) subastrocytic subsurface cisterns. Control rats injected with boiled toxin had no responses except (3) and (4) above, and then only to a modest extent, possibly due to mechanical damage of a few axons or terminals at the time of injection, or to insufficient inactivation of the toxin by boiling. The results were compared with those at 35 days after axotomy, and it was concluded that botulinum toxin, which interrupts neuromuscular transmission, elicits the same responses in the hypoglossal neurones, as does transection of the hypoglossal nerve, even though earlier studies had discovered no glial replication after botulinum toxin, in contrast to axotomy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237258
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    Responses in the hypoglossal nucleus to delayed regeneration of the transected hypoglossal nerve, a quantitative ultrastructural study (1977)
    Springer
    Experimental brain research 29 (1977), S. 219-231 
    Details
    ISSN: 1432-1106
    Keywords: Rat ; Hypoglossal nucleus ; Delayed regeneration ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Electron micrographs of the left hypoglossal nucleus of adult male albino rats were quantitatively analyzed from 9–70 days after allowing the transected left hypoglossal nerve to regenerate after an 84 day delay. Delay was achieved by implanting the proximal stump into already innervated sternomastoid muscle, where no regeneration occurred. Regeneration was then allowed by denervating the sternomastoid. During the regenerative period the initially high number of abnormally electron dense perikarya and dendrites decreased to almost normal values, but no cell removal was seen. This suggested that the degenerate appearance of many profiles after prolonged prevention of regeneration, was reversible. The neuropil bouton and dendrite counts, and the numbers of synapsing boutons per dendrite, increased steadily to normal values from the low values of suppressed regeneration. Somatic bouton frequencies, even though already low, decreased further at 32 days, and later increased but not to normal values. The decrease at 32 days coincided with the loss of many subsurface cisterns, and dispersion of Nissl substance, all suggestive of chromatolysis. Later the subsurface cisterns and Nissl substance returned. It was suggested that the delay of complete recovery of somatic bouton frequencies might be because of lack of sensory information from the denervated muscle into which the hypoglossal nerve was regenerating, or because of abnormally low starting values for the recovery phase. Astrocyte (or, occasionally microglial) sheaths persisted along boutonfree perikaryal surfaces.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237043
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    Unilateral renal hypoplasia with associated venous anomaly and hypertension (1977)
    Springer
    Virchows Archiv 374 (1977), S. 169-182 
    Details
    ISSN: 1432-2307
    Keywords: Juxtaglomerular apparatus ; Renin ; Kidney ; Congenital abnormalities ; Ultrastructure ; Hypertension ; Renal hypoplasia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A child with unilateral renal hypoplasia, high plasma renin levels and hypertension was found to have large numbers of juxtaglomerular granular cells in the affected kidney. They were seen adjacent to and sometimes in the interior of hyalinized glomeruli or, in loose nests scattered in the interstitium. Ultrastructurally they contained large numbers of crystalline protogranules in the Golgi region and also displayed other features suggestive of hyperactivity. Atrophic tubules, smooth muscle and mast cells were present in considerable numbers. Well-preserved renal cortex remained in the affected kidney with no demonstrable juxtaglomerular granularity. After unilateral nephrectomy the patient became normotensive and plasma renin levels became normal. Thus it appears that the juxtaglomerular cells are able to produce and release renin independent of the structural integrity of the juxtaglomerular apparatus and renal glomerulus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00432899
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    Hepatocyte giant mitochondria: An almost constant lesion in systemic scleroderma (1977)
    Springer
    Virchows Archiv 374 (1977), S. 215-227 
    Details
    ISSN: 1432-2307
    Keywords: Ultrastructure ; Liver ; Hepatocyte ; Mitochondria ; Gigantism ; Systemic scleroderma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Liver electron microscopic studies were performed in 14 patients with systemic scleroderma. In 13 of these patients, giant mitochondria were demonstrated in the hepatocytes. This ultrastructal abnormality was present whatever the type and duration of the disease and was also present even when the liver was histologically normal. The mechanism of formation of giant mitochondria in systemic scleroderma is unknown.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00427116
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  • 273
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    Giant cell tumor of bone (1977)
    Springer
    Virchows Archiv 376 (1977), S. 299-308 
    Details
    ISSN: 1432-2307
    Keywords: Giant cell tumor ; Ultrastructure ; Acid phosphatase ; Lysosomes ; Bone tumors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The fine structural localization of acid phosphatase in the different cells in a benign giant cell tumor of bone has been studied. Stromal cells type 1 and 2 (fibroblast-like and macrophage-like, respectively) showed the presence of lead phosphate precipitate following incubation in a Gomori-type lead salt medium only in conventional lysosomes. In the multinucleated giant cells, the final product was deposited over lysosome-like organelles, and also over Golgi cisternae, vesicles, and vacuoles. Furthermore, evidence for presence of acid phosphatase was obtained in smooth-surfaced tubular, sausage-, horse-shoe-, and ring-shaped structures and over digestive vacuoles of autophagic or heterophagic origin. Finally, in these cells, many of the tubular and vacuolar elements located subjacent to areas of the plasma membrane with microvillous specializations (abortive brush borders?) were shown to carry acid phosphatase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00432300
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    The endocrine cells of the pancreas and related tumours (1977)
    Springer
    Virchows Archiv 373 (1977), S. 327-352 
    Details
    ISSN: 1432-2307
    Keywords: Pancreatic endocrine cells ; Insulinomas ; Gastrinomas ; WDHA tumours ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Up to seven endocrine cell types have been identified ultrastructurally in the pancreas, including glucagon A cells, insulin B cells, somatostatin D cells, pancreatic peptide F cells and 5-hydroxytryptamine EC cells. In addition, D1 cells, which have been proposed as the cell type producing VIP and possible P cells of unknown function are seen. Various patterns of endocrine cell differentiation have been found in 20 endocrine pancreatic tumours. Well and poorly differentiated B cells have been identified in 6 insulinomas, diagnostic G cells in 3 out of 7 gastrinomas, D1 and/or F cells in 7 diarrheogenic tumours. Moreover, cells apparently unrelated to the prevalent clinical syndrome have been noted in 8 of the 20 tumours. Granular non diagnostic cells (poorly diagnostic gastrin cells? D1 cells?) were particularly frequent in gastrinomas; agranular or poorly granular cells, either of “active” or “stem cell” type, were present in nearly all tumours, particularly in diarrheogenic tumours, gastrinomas and malignant insulinomas. A cytological classification of pancreatic endocrine tumours is proposed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00432532
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    Immunhistochemical and electron microscope analysis of adenomas of the thyroid gland (1977)
    Springer
    Virchows Archiv 374 (1977), S. 285-301 
    Details
    ISSN: 1432-2307
    Keywords: Thyroid gland ; Thyroid adenoma ; Ultrastructure ; Immunhistochemistry ; Thyroglobulin ; Lysosomes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Histologic, immunhistochemical and electron microscopic changes in 8 cases of scintigraphically proven autonomous thyroid adenomas are described and compared with non-functioning adenomas. Adenomas with a light microscopic appearance suggesting autonomy show follicles which are mainly small or normal sized and lined by columnar thyroid cells with a partly vacuolated and eosinophilic cytoplasm. Immunhistochemically a high content of thyroglobulin corresponds to the amount of rough endoplasmatic reticulum. Typical ultrastructural criteria are a well developed cytocavitary network, numerous mainly apically localized lysosomes, prominent Golgi fields with sprouting vesicles and autophagic vacuoles. The cell surface is, when compared to non-functioning adenomas, enlared apically by numerous long microvilli and basally by deep infoldings. On contrast to experimentally TSH-stimulated animal thyroids, colloid droplets and pseudopodia are rare. The morphological findings are compared with recent biochemical results and the diagnostic value of electron microscopy is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00432652
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    Different types of benign nerve sheath tumors (1977)
    Springer
    Virchows Archiv 375 (1977), S. 197-210 
    Details
    ISSN: 1432-2307
    Keywords: Neuroma ; Neurofibroma ; Ultrastructure ; Cell-kinetic
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Verschiedene Typen von Nervenscheidentumoren wurden lichtmikroskopisch, elektronenmikroskopisch und autoradiographisch untersucht. Die elektronenmikroskopische quantitative Bestimmung der verschiedenen Zelltypen in den Tumoren ergab bei den Neurinomen eine überwiegende Beteiligung von Schwannschen Zellen (87,1%). Bei den Neurofibromen konnte eine unterschiedlich gro\e Anzahl von Bindegewebszellen nachgewiesen werden. Die diffusen Neurofibrome wiesen im allgemeinen eine Zellpopulation auf, wie man sie auch in normalen peripheren Nerven finden kann. Bei den plexiformen Neurofibromen überwogen die Fibroblasten und bei den argyrophilen Neurofibromen wurde eine hohe Perineuralzellbeteiligung gefunden. Die Proliferationsrate der Tumore in der Autoradiographie war im allgemeinen relativ gering, nur das argyrophile Neurofibrom wies einen deutlich höheren Markierungsindex (9,5%) auf.
    Notes: Summary In a light-, electronmicroscopic and autoradiographic study different types of nerve sheath tumors were classified. Their cellular population was quantitatively evaluated in the electron microscope. In the neurinoma the predominant cell was found to be the Schwann cell, but in the different types of neurofibromata a variable content of connective tissue cells was noted. The diffuse neurofibromata showed a quantitative cellular composition similar to normal peripheral nerves. In the plexiform neurofibroma a large number of fibroblasts were present and in the argyrophilic neurofibroma high content of perineurial cells was found. In autoradiographic sections the tumors showed in general a low proliferation rate (L.i. 1–3.6%). In the argyrophilic neurofibrom a higher labelling index (9.5%) was found.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01102988
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    Ultrastructure of Ewing's tumour (1977)
    Springer
    Virchows Archiv 374 (1977), S. 303-316 
    Details
    ISSN: 1432-2307
    Keywords: Ewing's tumour ; Ultrastructure ; Histochemistry ; Histogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Tumour tissue surgically excised from 10 patients bearing Ewing's tumour of bones was examined electron microscopically and histoenzymologically. In all cases the tumour was composed of polygonal cells with cytoplasm poor in organelles but with conspicuous aggregates of glycogen particles. There were numerous intercellular connections of desmosomal type and a distinct cell membrane bound positivity for alkaline phosphatase activity. In two cases in which there was a negative reaction for alkaline phosphatase, the lack of enzyme activity might have been related to cytotoxic treatment carried out for several months immediately before excision of the tissue used for histoenzymological studies. The problem of histogenesis of Ewing's tumour remains unresolved although some of the present findings support a haemangiogenic origin of the tumour.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00432653
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    Giant cell tumor of bone (1977)
    Springer
    Virchows Archiv 376 (1977), S. 273-298 
    Details
    ISSN: 1432-2307
    Keywords: Giant cell tumor ; Ultrastructure ; Bone tumors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We describe here the ultrastructure of the multinucleated giant cells and the mononuclear stromal cells in one case of giant cell tumor of bone. The most frequently occurring stromal cell (“stromal cell type 1”) was of fibroblast-like appearance with an irregular outline of both cells and nuclei. Characteristic features of the cytoplasm were the abundance of rough surfaced endoplasmic reticulum and the well developed Golgi apparatus; particulate glycogen was present in the ground cytoplasm of some cells. A second stromal cell type (“stromal cell type 2”) was also recognized, albeit more infrequently. It was macrophage-like with many mitochondria and lysosomes, but with a poorly developed endoplasmic reticulum. The composition of the fixative was found to influence considerably the appearance of the multinucleated giant cells, especially of their endoplasmic reticulum and Golgi-associated structures. Vacuolar elements with taillike expansions were frequently observed in the vicinity of the Golgi apparatus; their functional significance and relationship to the Golgi apparatus and the endoplasmic reticulum is enigmatic. Bodies with the appearance of conventional lysosomes occurred in limited numbers — while mitochondria were abundant. The structural organization and distribution of the endoplasmic reticulum varied between different regions of the cells. Nuclei were of irregular shape with deep infoldings of their limiting membranes and peripheral condensation of the chromatin. The possible nature of mononuclear cells in the neoplastic process is discussed. The morphologic evidence favors the conclusion that the fibroblast like stromal cell is neoplastic; convincing neoplastic properties are lacking for the type 2 cells. Although similarities exist between multinucleated giant cells and osteoclasts, distinct differences between the two cell types were noted. The origin, function and possible neoplastic nature of the giant cells is discussed on the basis of the findings presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00432299
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    Morbus Paget des Knochens (1977)
    Springer
    Virchows Archiv 376 (1977), S. 309-328 
    Details
    ISSN: 1432-2307
    Keywords: Paget's disease ; Osteoclasts ; Ultrastructure ; Cytogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Zur Frage der Cytopathogenese der Riesenosteoclasten beim Morbus Paget des Knochens wurden elektronenmikroskopische Untersuchungen an menschlichen Knochenbiopsien durchgeführt. Anteile von 26 aus diagnostischen Gründen entnommenen Beckenkammbiopsien wurden nach einem besonderen PrÄparationsverfahren unentkalkt für die Elektronenmikroskopie aufgearbeitet. Die Paget-Osteoclasten zeichnen sich durch eine hohe Kernzahl aus. Einzelne Zellkerne besitzen parakristalline Einschlüsse, die Hinweis auf eine Virusinfektion der Zellen sein können. Die Riesenosteoclasten zeigen eine gesteigerte Zellbeweglichkeit und hohe Resorptionsleistung durch Dissektion von Knochenfragmenten aus den endostalen OberflÄchen. Zwischen einkernigen Zellen und Osteoclasten finden sich ultrastrukturell Zellmembraninterdigitationen, die dem Vorgang der Zellfusion entsprechen. Die hÄufige Beobachtung dieser Zellmembrankontakte spricht für eine erhöhte Zellfusionstendenz von einkernigen VorlÄuferzellen der Osteoclasten beim Morbus Paget. Die VorlÄuferzellen stammen aus dem pericapillÄren Bereich und entsprechen morphologisch den Pericyten. Die Annahme einer gesteigerten Zellfusionsrate von einkernigen OsteoclastenvorlÄuferzellen würde die Entwicklung der Riesenosteoclasten erklÄren, die für den Morbus Paget des Knochens typisch sind. Ob diesem Vorgang ein durch Viren ausgelöster cytopathogener Effekt zugrunde liegt, mu\ durch weitere Untersuchungen an den parakristallinen Einschlüssen der Osteoclastenkerne geprüft werden.
    Notes: Summary The cytogenesis of giant osteoclasts in Paget's disease of bone was studied by means of electron microscopy. 26 iliac crest biopsies were made and divided for light and electron microscopic investigation. A special procedure was used for electron microscopic preparation of bone without previous decalcification. Paget osteoclasts are characterized by their high content of nuclei. Several nuclei may show paracrystalline inclusions pointing to a possible virus infection of these cells. Giant osteoclasts have an increased mobility and a high resorptive activity, manifest by the dissection of bone fragments from endosteal bone surfaces. Cell membrane interdigitations between mononuclear cells and osteoclasts occur as a morphologic concomitant of cell fusion. Frequent occurence of such cell membrane contacts seem to indicate an increased tendency to cell fusion among the mononuclear precursors of Paget-osteoclasts. Precursor cells are located in the pericapillary region, and morphologically resemble pericytes. The assumption of an increased rate of cell fusion amoungst the precursor cells of osteoclasts might explain the development of giant osteoclasts in this disease. Further studies of the paracrystalline nuclear inclusions of Pagetosteoclasts are necessary to determine whether this process can be considered to be a cytopathogenic effect of virus infection.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00432301
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    The ultrastructure of Rhesus monkey prostate (1977)
    Springer
    Urological research 5 (1977), S. 175-183 
    Details
    ISSN: 1434-0879
    Keywords: Monkey ; Prostate ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An ultrastructural study of immature and mature rhesus monkey prostate is described and a comparison is made with human tissue. The immature gland consists of largely undifferentiated epithelium showing little or no secretory activity. The mature gland exhibits the general characteristics of prostates of the other species studied. Columnar epithelial cells and undifferentiated basal cells are observed. The two lobes of the gland show several differences, the caudal lobe being rich in secretory granules, with the cranial lobe consisting of taller vacuolated cells. The description provides a basis for comparison with ultrastructural changes produced during in vivo and in vitro experimentation and with characteristics of normal and diseased human prostate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00263734
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    Die Ultrastruktur der Neointima arterieller Gefäßprothesen aus lyophilisierter menschlicher Dura (1977)
    Springer
    Research in experimental medicine 169 (1977), S. 243-251 
    Details
    ISSN: 1433-8580
    Keywords: Ultrastructure ; arterial prostheses ; lyophilized human dura ; neointima ; Ultrastruktur ; arterielle Gefäßprothesen ; lyophilisierte menschliche Dura ; Neointima
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 5 aus lyophilisierter menschlicher Dura (LMD) hergestellte und Hunden implantierte Arterienprothesen wurden nach 4, 5 1/2, 13, 43 und 46 Monaten entnommen und elektronenmikroskopisch untersucht. Die Neointima aller Implantate bestand aus Pseudo-Endothelzellen, Fibrozyten und Kollagenfibrillen. 43 und 46 Monate nach Implantation waren außerdem glatte Muskelzellen und elastische Mikrofibrillen in der Neointima vorhanden. Diese entsprach somit in ihrer Zusammensetzung im wesentlichen der Neointima von Kunststoff- und Kollagen-Kunststoff-Arterienprothesen. Die klinische Erprobung von LMD-Implantaten als arterieller Gefäßersatz ist jedoch wegen degenerativer Wandveränderungen in den Prothesen mit fast vierjähriger Verweildauer vorerst noch zu früh.
    Notes: Summary Five arterial prostheses made of lyophilized human dura (LHD) were inserted into dogs and removed after 4, 5 1/2, 13, 43, and 46 months to be studied with the electron microscope. The neointima of all grafts consisted of pseudo-endothelial cells, fibrocytes, and collagen fibrils. Additionally, 43 and 46 months after implantation smooth muscle cells and elastic microfibrils were present. Thus, the composition of the neointima was substantially identical with that of the neointima of synthetic arterial grafts and collagenfabric ones. The clinical application of arterial prostheses of LHD, however, seems at present too early because of degenerative changes in the walls of those grafts which remained nearly 4 years in the dogs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01852062
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    Histological and ultrastructural changes in rat kidney following cadmium injection (1977)
    Springer
    Urological research 5 (1977), S. 15-20 
    Details
    ISSN: 1434-0879
    Keywords: Cadmium ; Kidney ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Cadmium injection in rats affects the genito-urinary system. The renal effects are generally considered to be mainly tubular. Light microscopy of 29 specimens confirms cellular damage in the glomeruli with changes in glomerular capillaries. Electron microscopic changes in the glomeruli confirm changes in the podocytes, thickening of the basement lamina, the occurrence of electron dense deposits in association with the capillary endothelium with platelet and polymorphonuclear cell accumulations which suggests opening of the endothelial junction of the glomerular vessels.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00257111
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    Population and structure of nerve cells in mouse submandibular ganglion (1977)
    Springer
    Anatomy and embryology 150 (1977), S. 301-312 
    Details
    ISSN: 1432-0568
    Keywords: Neuron ; Ultrastructure ; Anatomy ; Submandibular ganglion ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The anatomy of the mouse submandibular ganglion, and population and fine structure of nerve cells were studied by light and electron microscopy. The submandibular ganglion is a plexus containing up to forty ganglia along the main and the smaller excretory ducts of the submandibular gland. Measurements of the volume of nerve cell bodies display a pattern of distribution with two main peaks, suggesting the presence of large and small types of the intraganglionic neuron. The large neurons mainly have axo-dendritic synapses in which the postsynaptic element is a small spine-like process, while axo-somatic synapses are more common in the small neurons. In some small neurons nuclear chromatin is unusually conspicuous, and accumulations of vesicles of fairly uniform size occur within the cell body. Decentralized ganglia contain almost no synapses, showing the absence of definite interneurons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00318348
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    An electron microscope study of the differentiating capillaries of the mouse neurohypophysis (1977)
    Springer
    Anatomy and embryology 152 (1977), S. 89-108 
    Details
    ISSN: 1432-0568
    Keywords: Neurohypophysis ; Capillaries ; Mouse ; Growth and development ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The developing capillaries of the mouse neurohypophysis were studied in the electron microscope to elucidate the fine structural differentiation of the vascular component of the neuro-hemal contact zones in the external median eminence and the neural lobe. In the embryo the growth of the superficial net of the primary plexus of the hypophysial portal system is largely manifested by the presence of proliferation areas located within the capillary plexus covering the surface of the median eminence. Presumptive shallow capillary loops diverge from these areas in the first postnatal week. Differentiation of the capillary wall follows the pattern outlined for continuous capillaries. A few fenestrae appear in the endothelium of immature, superficial vessels at the 17th gestational day, increase in frequency during the following embryonic days, and occur regularly in the postnatal animal. In the neural lobe the internal capillaries proliferate by vascular sprouts emanating from the vessels on the surface of the gland. At the end of embryonic time an extensive net has developed, composed of capillaries with immature characteristics. Proliferation is largely finished by the end of the third postnatal week, when mature capillaries dominate the picture. Formation of attenuated, porous areas is a postnatal process, apart from single fenestrae appearing in the walls of a few immature capillaries in late fetal life. The structural possibilities for an onset of neurohypophysial function in the mouse is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00341437
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    Etude ultrastructurale du paraplacenta de chatte: mécanisme de l'érythrophagocytose par la cellule chorionique (1977)
    Springer
    Anatomy and embryology 151 (1977), S. 267-283 
    Details
    ISSN: 1432-0568
    Keywords: Placenta ; Erythrophagocytosis ; Ultrastructure ; Function
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé Localisé de part et d'autre du labyrinthe, le paraplacenta ou “bordure brune”, est constitué de la membrane allanto-chorionique faisant face à l'épithélium utérin. Les cellules chorioniques phagocytent et dégradent des hématies d'origine maternelle; cette activité est probablement cyclique. Durant la phase d'“ingestion”, l'hématie est phagocytée à l'apex de la cellule, puis après fusion de lysosomes avec la vacuole phagocytique, la phase “digestive” commence et se déroule principalement dans la zone médiane de la cellule, au niveau de vacuoles de tailles plus réduites. Certaines vacuoles contiennent des figures myéliniques associèes ou non à des granules de taille variable, d'autres un matériel finement granulaire. La brève phase d'élimination se caractérise par la présence au voisinage de la lamelle basale et des capillaires foetaux, de corpuscules de 1,000 Å probablement constitués d'agrégats de particules de ferritine. Ces corpuscules exhibent une activité pseudoperoxydasique. Cette érythrophagocytose placentaire représente la source principale de fer pour le foetus. Les microvilli, les vésicules de micropinocytose, le système tubulaire et les corps multivésiculaires de la zone apicale de la cellule, suggèrent une fonction d'absorption de protéines de la cellule. Il en est de même de la richesse du “cell coat” de la surface membranaire apicale.
    Notes: Summary Located on all sides of the placental labyrinth, the paraplacenta or “brown border” is constituted by the chorioallantoic membrane and the uterine mucosa facing it. The chorionic cells are actively engaged in the uptake and subsequent breakdown of extravased maternal erythrocytes. This phagocytic activity is probably cyclic in nature. In the “ingestion” phase an erythrocyte is phagocytosed in the apex of a chorionic cell, and the “digestive” phase occurs after fusion of lysosomes with the phagocytic vacuole. Subsequent breakdown of the red cell membrane leads to release of the content of the erythrocyte into the vacuole. Then the breakdown proceeds in smaller vacuoles of the median zone of the cell. Some vacuoles contain concentric whorls of membrane, associated with granules of variable size; others contain a finely granular material. The short-lived final, or “elimination,” phase is characterized by the presence of 1,000 Å finely granular bodies along the basement membrane and in close approximation to fetal capillaries. These non-membrane-bound bodies seem to be constituted of ferritinlike particles and exhibit pseudoperoxydasic activities with D.A.B. procedures. This paraplacental erythrophagocytosis is the major source of iron for the fetus. At their apical surface, the chorionic cells exhibit microvilli, micropinocytotic vesicles and a well-defined “cell coat.” The underlying cytoplasm contains numerous absorption vesicles or tubules and multivesicular bodies suggestive of protein absorption.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00318930
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    Absorption of horseradish peroxidase by the principal cells of the large intestines of postnatal developing rats (1977)
    Springer
    Anatomy and embryology 151 (1977), S. 53-62 
    Details
    ISSN: 1432-0568
    Keywords: Large intestine ; Intestinal absorption ; Postnatal development ; Rat ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The absorption of horseradish peroxidase in the rat large intestine during the postnatal developing period was investigated by cytochemical and ultrastructural methods. In the ceca and ascending colons from 4-, and 5-day-old rats, intraluminaly injected peroxidase became localised on microvilli, in the intracytoplasmic network of the apical tubules and small vacuoles (tubulo-vacuolar system), in the large supranuclear vacuole, in the Golgi apparatus, on the lateral and basal cell membranes of the surface principal cells, and also in the lumen of blood capillaries in the subjacent propria. On the other hand, the protein tracer was not seen in the large intestinal epithelial cells that lack tubulo-vacuolar systems and large supranuclear vacuoles within their cytoplasm. In the descending colons of rats of any postnatal age, the epithelial principal cells are devoid of these membrane systems, and exogenous peroxidase was not detected in the cytoplasm of the principal cells. It is assumed that at least the proximal portion of the large intestine in neonatal animals has the capacity to absorb macromolecular protein through those surface principal cells that have specialized intracellular membrane systems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00315297
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    Meningioma and intracranial hemangiopericytoma (1977)
    Springer
    Acta neuropathologica 39 (1977), S. 69-74 
    Details
    ISSN: 1432-0533
    Keywords: Hemangiopericytoma (intracranial) ; Meningioma ; Ultrastructure ; Leiomyoblastic differentiation ; Intercellular junctions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Electron microscopic study of 2 intracranial hemangiopericytomas and 7 meningiomas revealed fundamental morphologic differences between the 2 neoplasms. The most significant finding in hemangiopericytoma was the presence of ultrastructure features suggesting leiomyoblastic differentiation. These included characteristic fusiform intracytoplasmic and submembranous dense bodies, abundant cytoplasmic filaments, elongated cells with blunt-ended nuclei and juxtanuclear polarization of organelles. This observation is considered highly significant as an indicator of the pericytic nature of this tumor. In addition, hemangiopericytoma cells sometimes were arranged in spirals around pools of basement membrane-like material, perhaps a manifestation of the biologic capability of the cells to synthetize such material. Meningioma cells displayed as their main feature an ability to produce surface membrane specializations including interdigitations, desmosomes, zonulae adhaerentes and gap junctions. Sometimes the last 3 elements were linearly juxtaposed forming junctional complexes similar to those seen in certain epithelia. It is suggested that the characteristic whorls of meningioma are the result of cell interconnections arising from the specialized junctional attachments. Thus the distinctive morphology of the 2 neoplasms appears to derive from basic biologic properties of their elements.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00690387
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    Ultrastructural changes in blood vessels of peripheral nerves in leprosy neuropathy. II. Borderline, borderline-lepromatous and lepromatous leprosy patients (1977)
    Springer
    Acta neuropathologica 40 (1977), S. 21-39 
    Details
    ISSN: 1432-0533
    Keywords: Leprosy neuropathy ; Ultrastructure ; Angiopathy ; Endothelium ; Mycobacterium leprae ; Immunology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of blood vessels in endo-, peri- and epineurium was studied in peripheral cutaneous nerve biopsies of 16 borderline (BB), borderline-lepromatous (BL) or lepromatous (LL) leprosy patients some of whom were in reversal reaction. Comparable vessels in nerve biopsies of control cases and vessels in skin lesion biopsises of the leprosy patients were also studied. Vascular changes were found in nerves of all the leprosy patients. The changes were pronounced in endoneurial vessels and affected 1. endothelial continuity and surface structure, 2. basement membranes of endothelium and pericytes, and 3. the vessel lumen. In addition, intra-endothelial (IE)Mycobacterium leprae were a feature in some of the patients. Gaps occurring between endothelial cells and plasma insudation both noticed in vessels of fascicles with early to very early neuropathy suggested extensive leakage which, in all probability, causes early nerve fibre damage. Luminal and abluminal endothelial protrusions, which were frequently observed, may enhance transendothelial transport. Fenestrations and endothelial attenuation, possibly, lead to an increase in vascular permeability. Endothelial phagocytotic activity, particularly in small (epineurial) arteries, appeared to be stimulated, possibly, by circulatingM. leprae. Basement membrane multilayering (a “hyaline zone”) was found peripherally to pericytes, as is the case in tuberculoid leprosy (Boddingius, 1976). In a number of patients, multilayering occurred also peri-endothelially. Perivascular zones, which are thought to initiate or aggravate neuropathological changes by impairment of diffusion of oxygen and nutrients or metabolites, were very wide in endoneurial vessels of patients in reversal reaction and this suggested an immunological aetiology. Partial or total vessel lumen occlusion, seen in advanced lepromatous neuropathy, most likely contributes to final nerve fibre degeneration and endoneurial fibrosis. M. leprae were found intra-endothelially in endoneurial vessels, though only in fascicles with advanced neuropathy whereas bacilli were not seen in vessel lumina. By contrast, in fascicles with relatively early neuropathy, solid (viable) bacilli were frequently encounteredintra-axomally in myelinated fibres. This suggests that, in many instances, primary infiltration ofM. leprae into nerve fascicles may arise from intra-axonal (IA) bacilli which ascend from dermal nerves and are released within main nerve trunks after demyelination of the host fibre.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00688570
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    Subependymoma (1977)
    Springer
    Acta neuropathologica 40 (1977), S. 279-282 
    Details
    ISSN: 1432-0533
    Keywords: Subependymoma ; Subependymal glomerate astrocytoma ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case history illustrating the potential clinical significance of subependymoma is presented. Fine structural studies indicate that the tumor is composed of cells having the cytoplasmic features of ependyma, astrocytes, and transitional cells. Its composition and structure are alike those in the adult mammalian subependymal layer.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00691968
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    Lymphomatoid granulomatosis with cerebral involvement (1977)
    Springer
    Acta neuropathologica 37 (1977), S. 193-197 
    Details
    ISSN: 1432-0533
    Keywords: Lymphomatoid granulomatosis ; Ultrastructure ; Cerebrum ; Lymphocyte ; Plasma cell ; Immunoblast
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Light and EM study of a case of lymphomatoid granulomatosis revealed a pleomorphic lymphoreticular cell infiltrate, angiitis and necrosis with involvement of the brain, lungs, skin and right ear of a 30 year old woman. Cells comprising the infiltrate were classified as lymphocytoid, plasmacytoid, immunoblastic (histocytic) and phagocytic. A number of elements partook of the ultrastructural features of two cell types and were considered to be intermediate froms (plasmacytoid lymphocytes, lymphocytoid immunoblasts, and plasmacytoid immunoblasts). It is believed that the various cell elements from part of a wide spectrum in which transformation of cell types takes place by maturation. This suggests an immunologic process as the main pathogenetic factor in the development of LG.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00686878
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    Ultrastructure of striated muscle of the rat after temporary ischemia (1977)
    Springer
    Acta neuropathologica 37 (1977), S. 237-245 
    Details
    ISSN: 1432-0533
    Keywords: Temporary ischemia ; Rat striated muscle, motor end-plates ; Ultrastructure ; Degeneration, regeneration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Twenty-six anterior tibial muscle specimens were analyzed with the electron microscope 2h, 1, 4, 18, 45, 90 and 226 days after temporary ischaemia of the rat hind leg produced by pneumatic tourniquet for 1, 2, 3, 4 and 6 h. No ultrastructural alterations were seen after 1 h ischaemia, but reversible disappearance of muscle glycogen and swelling of muscle and nerve mitochondria occurred after 2 h ischaemia. Irreversible alterations such as disappearance of the Z-line, disruption of cell membrane and vacuolation of muscle mitochondria were observed after ischaemia of 3 h and longer in a part of the muscle fibres. Ischaemia for 6 h was followed by autolysis of all the muscle fibres within the specimens. Autolysis and phagocytosis of the remnants of the affected fibres was present on the 4th day. On that day regenerative phenomena were also observed, such as satellite cells and yound myotubes. The fine structure of the muscle fibres was normal on the 18th day after the temporary ischaemia, although some size variation of the muscle fibres was still observed. Degeneration of a part of the presynaptic nerve endings of motor end-plates with or without simultaneous degeneration of the postsynaptic muscle fibre was seen after ischaemia lasting 3 h or longer. Motor end-plates were first seen on the 45th day in the muscle subjected to 6 h ischaemia and were most likely regenerated ones.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00686885
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  • 292
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    Abetalipoproteinemia (Bassen-Kornzweig syndrome) (1977)
    Springer
    Acta neuropathologica 37 (1977), S. 255-258 
    Details
    ISSN: 1432-0533
    Keywords: Abetalipoproteinemia ; Muscle ; Ceroid ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A 26-year old male suffered from Abetalipoproteinemia (Bassen-Kornzweig disease). In addition to C.N.S. lesions, he had myopathy. A muscle biopsy revealed accumulation of ceroid pigment in the striated muscle. A few muscle fibers showed severe degeneration of the myofibrils. Fibroblasts and macrophages in the interstitial tissue contained abundant ceroid. The relation between ceroid accumulation, abetalipoproteinemia and vitamin E-deficiency is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00686887
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    The cytoplasmic architecture of the egg cell ofSmittia spec. (Diptera, Chironomidae) (1977)
    Springer
    Development genes and evolution 183 (1977), S. 233-248 
    Details
    ISSN: 1432-041X
    Keywords: Cytoplasmic architecture ; Ultrastructure ; Insect egg ; Pattern formation ; Yolk ; Cytoplasma-Architektur ; Ultrastruktur ; Insekten-Ei ; Musterbildung ; Dotter
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung 1. Das Ei der ZuckmückeSmittia spec. wurde licht- und elektronenmikroskopisch untersucht. Die vorliegende Arbeit beschreibt den Bau des Periplasmas und des Dotter-Endoplasma-Systems vor Bildung der Polzellen. 2. Das Periplasma, nach außen vom Oolemm und einer mehrschichtigen Eihülle begrenzt, besteht aus einer ribosomenreichen cytoplasmatischen Matrix, in die vor allem Mitochondrien und ER-Zisternen, wenig annulate lamellae und gelegentlich Golgi-Apparate eingelagert sind. Mikrotubuli wurden nur selten nachgewiesen. Öfters sind Anhäufungen einer dichten granulierten Substanz zu beobachten, die in ihrer Struktur dem Oosom-Material ähnelt. 3. Das Dotter-Endoplasma-System stellt ein Netzwerk aus Cytoplasma dar, in das Proteid-Dotterkugeln, Lipidtröpfchen sowie Glycogen-Anhäufungen eingelagert sind. Das Endoplasma, das sich zu 3–7 Plasma-Inseln erweitern kann und unmittelbar in das Periplasma übergeht, besteht wie dieses aus einer cytoplasmatischen Matrix und enthält die gleichen Zellelemente wie das Periplasma. Rosettenförmige Membran-Strukturen werden als “nuclear envelope organizing center” gedeutet. 4. Drei der sorgfältig analysierten Eier enthielten je 2 Kerne; sie lagen in Plasma-Inseln in der hinteren Eihälfte. 5. Sowohl im Periplasma wie im Dotter-Endoplasma-System sind alle Zellelemente unregelmäßig verteilt. Eine besondere Anordnung oder Zonierung ist nicht zu erkennen. 6. Die räumliche Verteilung der erfaßten Eikomponenten liefert keine Hinweise auf eine Funktion dieser Komponenten als Determinanten für die embryonale Musterbildung.
    Notes: Summary 1. Eggs of the midgeSmittia were investigated by light microscopy and transmission electron microscopy. This paper describes elements and architecture of periplasm and yolk endoplasm before the formation of pole cells. 2. The periplasm is coated externally by the oolemma and a multilayered egg shell. The periplasm consists of a cytoplasmic matrix rich in ribosomes; it contains mitochondria and ER cisternae, some annulate lamellae and an occasional Golgi complex. Microtubuli were demonstrated only rarely. Accumulations of a dense granulated substance resembling in its structure the oosome material were frequently observed. 3. The yolk endoplasm is a cytoplasmic network embodying proteid yolk particles, lipid droplets and accumulations of glycogen. The endoplasm is continuous with the periplasm and shows the same cell constituents. It may form between 3 and 7 cytoplasmic islands free of yolk particles. Rosette-shaped membranous structures in the yolk endoplasm are interpreted as nuclear envelope organizing centres. 4. Three carefully analysed eggs contained 2 nuclei each. both nuclei were situated in the posterior egg half. 5. Periplasm and yolk endoplasm are characterized by random distribution of cell elements. No zonation or special accumulations could be recognized. 6. The spatial distribution of the egg components studied did not indicate that any of these components could function as a determinant in embryonic pattern formation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00867324
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    Ultrastructure of a fertilized barnacle egg (Pollicipes polymerus) with peristaltic constrictions (1977)
    Springer
    Development genes and evolution 181 (1977), S. 333-355 
    Details
    ISSN: 1432-041X
    Keywords: Barnacle eggs ; Constriction rings ; Microfilaments ; Ultrastructure ; Peristalsis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary 1. The egg ofPollicipes polymerus, the common intertidal gooseneck barnacle, has been studied by electron microscopy. Constriction rings, similar to the contractile rings of cleaving cells and polar lobes, move unidirectionally from the animal to the vegetal pole of newly fertilized eggs. This is referred to as peristaltic constriction. The present paper describes the fine structure of the egg during first polar body formation and peristalsis. 2. During formation of the polar body, dense bodies are produced by the Golgi and extracellular plaques are observed. Thin microfilaments (40–60 Å) are in the egg adjacent to the polar body. 3. In eggs undergoing peristalsis, the appearance of extracellular spheres, flocculent material and filaments is observed. Intracellularly large numbers of multivesiculate bodies, glycogen granules, mitochondria and protein-carbohydrate and lipid yolk bodies are seen at the level of constriction. 4. Thin microfilaments are found in the cortical area of newly-fertilized eggs exclusively in peristaltic constriction rings. Filaments are oriented primarily in a meshwork, although circumferentially-oriented filaments are also found in rings near the vegetal pole. Microvilli extend into the space created between a constriction and the elevated egg membrane. 5. A model is proposed to explain the peristalsis in this species. It is suggested that information from a pacemaker region activates peristalsis by affecting filament polymerization and orientation. One function of peristalsis may be elongation of the egg from a sphere to an ovoid, although other possibilities such as elevation of the egg membrane, segregation of the lipid yolk to the vegetal pole and predetermination of the first cleavage plane are also discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848060
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    Degeneration of two of nine types of synapses in the putamen after center median coagulation in the cat (1977)
    Springer
    Experimental brain research 28 (1977), S. 345-361 
    Details
    ISSN: 1432-1106
    Keywords: Putamen ; Cat ; Center median parvocellular neurons ; Ultrastructure ; Degenerated boutons (type VII and IV)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The cat putamen contains the identical nine types of synapses and the same proportion of axo-dendritic (or axo-somatic) synapses as described for the fundus striati. However, type III (cortico-striatal) (31∶16%) and type V (axon-collateral) (13∶1%) occur much more frequently and type I (nigro-striatal) much less frequently (14∶34%) in the putamen than in the fundus striati. Of the axo-spinous synapses only type IV, with densely arranged small round vesicles and interrupted, asymmetric contact, shows a dark degeneration after center median lesions, mainly in the parvocellular part. Of the six axo-dendritic (or axo-somatic) synapses, only type VII, with densely packed small round vesicles and asymmetric contact, is degenerated after the same lesion in the center median nucleus. However, after such lesions type VII synapses are much more frequently degenerated in the putamen than those of type IV.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235716
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    Ultrastructural damage due to freezing followed by thawing in shoot meristem and leaf mesophyll cells of tall fescue (Festuca arundinacea Schreb.) (1977)
    Springer
    Planta 134 (1977), S. 159-168 
    Details
    ISSN: 1432-2048
    Keywords: Festuca ; Frost damage ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Tillers of Festuca arundinacea Schreb. were subjected to-8°C in a bath of methylated spirits for three-quarters of an hour. They were thawed at room temperature and some material taken from the shoot apical meristem and leaf blade for electron microscopy. Similar material was taken from control plants for electron microscopy. Nine tillers subjected to-8°C and thawed subsequently failed to regrow. Nine control tillers regrew. All the treated meristem cells and about half the treated leaf mesophyll cells were extensively altered. Their nuclei were contracted, organelles were swollen or partly disrupted, plasmalemma and nuclear membranes were broken or absent and vacuoles were sometimes disrupted. Strongly osmiophilic material accumulated in the vicinity of membranes. About half the leaf mesophyll cells differed from the control mesophyll cells only in having more spherosomes and narrower thylakoids. Parallels with other ultrastructural studies of stress damage and the indications the results give of possible primary damaging events are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00384966
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    Mycoparasitic relationships (1977)
    Springer
    Archives of microbiology 111 (1977), S. 207-224 
    Details
    ISSN: 1432-072X
    Keywords: Host-parasite relationships ; Ultrastructure ; Papillae ; Infection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The mode of attack and the infection structures of the necrotrophic mycoparasite, Pythium acanthicum, as well as the responses of various fungal hosts to parasitism were studied using both electron and light microscopy. Many taxonomically distinct fungal hosts were used, though Phycomyces blakesleeanus, Pythium aphanidermatum, Rhizoctonia solani and a basidiomycete identified as Corticium sensu lato were studied in greatest detail. Parasitism was by direct penetration of the fungal host without appressorium formation by the parasite. The host's cells responded to contact by P. acanthicum by forming papillae. The morphological features of the papillae varied with the particular host. In P. blakesleeanus they were comprised of vesicles and segments of cytoplasm entrapped in a fibrillo-granular matrix, while in R. solani and the Corticium basidiomycete they contained considerable amounts of electron-opaque and electron-translucent material. Evidence for both mechanical and enzymatic penetration of the host fungi by the parasite are presented. Details of host wall and septum penetration by the parasite are presented using time-lapse light microscopy with in vivo systems. Many of these stages of parasitism were examined ultrastructurally. Some comparisons of these mycoparasitic relationships are discussed in relation to what is known from the literature about phytoparasitic interactions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00549358
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    Gametangial development in Allomyces macrogynus (1977)
    Springer
    Archives of microbiology 113 (1977), S. 163-172 
    Details
    ISSN: 1432-072X
    Keywords: Allomyces ; Phycomycete ; Ultrastructure ; Gametangial differentiation ; Autophagy ; Gamma bodies ; Multivesicular bodies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The ultrastructure of gametangial development in Allomyces macrogynus was determined from longitudinal sections of gametophytic hyphae at stages of differentiation from vegetative apices at time zero to fully cleaved gametangia at about 150 min. Whereas vegetative hyphae show an apical clustering of mitochondria, cytoplasmic vesicles and microtubules, this arrangement was sharply altered in early development. Mitochondria were evenly redistributed, apical vesicles and microtubules disappeared, and autophagic vacuoles became prominent. Subsequently, electron-dense granules and microbody/lipid droplet complexes became evident and later, during gamete cleavage, developed into gamma bodies and side-body complexes respectively. Meanwhile cytoplasmic vesicles were involved in exit papilla formation. The significance of autophagic vacuoles and multivesicular bodies is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00492020
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    Dorsal-ventral differentiation in Simonsiella and other aspects of its morphology and ultrastructure (1977)
    Springer
    Archives of microbiology 113 (1977), S. 197-204 
    Details
    ISSN: 1432-072X
    Keywords: Gliding bacterium ; Simonsiella ; Oral cavity ; Electron microscopy ; Morphology ; Dorsal-ventral differentiation ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The morphology and ultrastructure of the aerobic, Gram-negative multicellular-filamentous bacteria of the genus Simonsiella were investigated by scanning and transmission electron microscopy. The flat, ribbon-shaped, multicellular filaments show dorsal-ventral differentiation with respect to their orientations to solid substrata. The dorsal surface, orientated away from the substrate, is convex and possesses an unstructured capsule. The ventral surface, on which the organisms adhere and glide, is concave and has an extracellular layer with fibrils extending at right angles from the cell wall. The cytoplasm in the ventral region contains a proliferation of intracytoplasmic membranes and few ribosomes in comparison to the cytoplasm in other parts of the cell. Centripetal cell wall formation is asymmetrical and commences preferentially in the ventral region. Quantitative differences in morphology and cytology exist among selected Simonsiella strains. Functional aspects of this dorsalventral differentiation are discussed with respect to the colonization and adherence of Simonsiella to mucosal squamous epithelial cells in its ecological habitat, the oral cavities of warm-blooded vertebrates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00492025
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    Two unicellular cyanobacteria which reproduce by budding (1977)
    Springer
    Archives of microbiology 115 (1977), S. 249-257 
    Details
    ISSN: 1432-072X
    Keywords: Chamaesiphon spp. ; Cyanobacteria ; Reproduction by budding ; Ultrastructure ; Nutritional properties ; DNA base composition ; Fatty acid composition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Two strains of unicellular cyanobacteria which reproduce exclusively by budding are described and assigned to genus Chamaesiphon.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00446449
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