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  • 2000-2004  (21)
  • 1970-1974  (425)
  • 1920-1924
  • 1890-1899
  • Electron microscopy  (446)
  • 101
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 147 (1974), S. 567-588 
    ISSN: 1432-0878
    Keywords: Macrophage ; Freund's adjuvants ; Stimulation ; Stereology ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The principles of stereology have been applied to a stereometric analysis of the ultrastructural composition of normal rat peritoneal macrophages and of cells stimulated five days previously by a single intraperitoneal dose of Freund's adjuvants. Material obtained by a systematic random sampling regime was analysed and the data groups for various morphological parameters were compared. Estimates were made of cell numbers. From electron micrographs the volume proportions of nuclei, mitochondria, heterogeneous granules and rough endoplasmic reticulum were determined. The average numbers and dimensions of mitochondria, granules and free ribosomes were also evaluated. The volume-to-surface ratios of cells and their nuclei were computed. By the independent measurement of cellular volumes it was possible to obtain estimates of nuclear and cytoplasmic volumes, to evaluate the membrane surface areas of the average cells and their nuclei, and to calculate numbers of organelles per average cell. The structural alterations induced by the complete adjuvant were similar to those evoked by the incomplete adjuvant. Stimulation was characterized by a cellular hypertrophy accompanied by an increase in mean granule size and in the number of mitochondria per average cell. At the same time, there was a substantial decrease in the number of granules and a considerable depletion of both nuclear and plasma membrane surface areas.
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  • 102
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    Electronic Resource
    Springer
    Cell & tissue research 148 (1974), S. 397-406 
    ISSN: 1432-0878
    Keywords: Thymus ; “Nude” mouse ; Ciliogenesis ; Ciliary anomalies ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The thymus of the “nude” mouse is composed of ciliated cysts. In the adult mouse, different steps of ciliogenesis can be observed. The ciliated cells exhibit several anomalies in the centriole and in the cilium itself; the most important ones are the half-centriole and the compound cilia. An explanation for the occurrence of frequent anomalies in ciliated cells is suggested. Finally, some single cilia are described in fat cells.
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  • 103
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    Springer
    Cell & tissue research 148 (1974), S. 577-586 
    ISSN: 1432-0878
    Keywords: Node of Ranvier ; Axonal-glial junctions ; Cat ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The paranodal zone of myelinated nerve fibers from the CNS of cats has been studied by means of the lanthanum technique and after freeze-etching. Special interest was given to the axonal-glial zones of contact in this region. Examination of the membranes of the paranodal pockets and the axolemma revealed that the membrane thickenings which occur between the adjacent membranes actually consist of bands. The bands show a specific pattern of diagonal running subunits 10 nm apart. These substructures of the axonal side of the membrane contacts protrude outwards, i.e. towards the glial membrane, where they fit into depressions on the glial membrane surface. This arrangement in form of a “zip-fastener” makes the whole structure very flexible. The subdivision of the bands was identified with both techniques. The different membrane aspects obtained by the freeze-etching technique are discussed in respect to the splitting theory, and a hypothetical model of this membrane specialization is presented.
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  • 104
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    Springer
    Cell & tissue research 148 (1974), S. 57-67 
    ISSN: 1432-0878
    Keywords: Prostate ; Rat ; Cyproterone ; Alterations ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The dorsal lobe and the coagulating gland of the rat prostate were studied after administration of the anti-androgenic compound Cyp A for varying periods (7–20 days). There was a general involution of the organs with macroscopic atrophy and reduced amount of secretory material. Ultrastructurally the cells were pale, contained less organelles as compared with the controls, loss of cytoplasm and reduction both of cell height and width. The major changes also included reduction of the Golgi area, the rough endoplasmic reticulum and the number of free ribosomes. Within the dorsal lobe prominent nuclear changes were found, comprising different types of intranuclear inclusions of membranous configurations. The alterations observed in the present study are similar to the changes which were found in castrated animals and are consistent with atrophy. The results are discussed in relation to the available biochemical and autoradiographic data on the different lobes.
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  • 105
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    Springer
    Cell & tissue research 148 (1974), S. 287-300 
    ISSN: 1432-0878
    Keywords: Symbiotes ; Aphids ; Antibiotics ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects of penicillin and chlortetracyline HCl on the fine structure of the intracellular symbiotes of the pea aphid were studied in an attempt to remove the symbiote population. High penicillin concentrations, 1% and 0.1%, caused symbiote breakdown but were toxic and/or repellent to the aphids; at 0.1% specific effects were observed on the symbiotes' cell walls. After the use of 0.01% penicillin in the aphid diet, the symbiotes had abnormal cell walls and were abnormally dilated; however, symbiote division and transmission from one aphid generation to the next seemed unaffected and the aphids appeared normal. Aphids fed 0.1% chlortetracycline failed to reproduce. After 7 days, their symbiotes were found to break down at a high rate but aphid mitochondria were also adversely affected at this stage. Following 0.002% chlortetracycline, the aphids produced aposymbiotic progeny with apparently normal mitochondrial populations; these larvae failed to develop.
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  • 106
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    Cell & tissue research 148 (1974), S. 561-563 
    ISSN: 1432-0878
    Keywords: Pancreatic islets ; Xiphophorus helleri ; A2-Granules ; Crystalline structure ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary By tilting experiments in the electron microscope evidence was found for crystalline islet A2-granules of Xiphophorus helleri H. to be rhombic dodecahedral and thus to belong to the cubic system.
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  • 107
    ISSN: 1432-0878
    Keywords: Spleen ; Thymus dependent area ; Periarteriolar lymphatic sheath (PALS) ; Interdigitating cell (IDC) ; T-lymphocyte ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary To study the submicroscopical morphology of the microenvironment for T-lymphocytes in the spleen, mice were lethally X-irradiated and injected intravenously with syngeneic thymocytes. 24 hours after cell transfer, small lymphocytes occurred in the thymus dependent area of the spleen: the periarteriolar lymphatic sheath (PALS). They localized preferentially around a special type of mononuclear phagocyte, the Interdigitating Cell (IDC), which is considered to be characteristic for thymus-dependent areas in peripheral lymphoid organs. A close cell contact between both cell types was observed: small lymphocytes protruded into the cytoplasm of the IDC by means of fingerlike protrusions. This type of cell contact seems to induce blast transformation of the lymphoid cells which resulted in the formation of medium sized T-cells. In a control experiment, spleen cells from thymectomized, X-irradiated and bone marrow reconstituted mice were injected intravenously into lethally X-irradiated recipients. These B-lymphocytes, however, were not found to be localized around IDC. They preferentially formed primary follicles at the periphery of lymphocyte-depleted thymus dependent areas.
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  • 108
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    Cell & tissue research 147 (1974), S. 219-235 
    ISSN: 1432-0878
    Keywords: Lysosomes ; Mouse fibroblasts ; Dye treatment ; Cell culture ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Mouse fibroblasts were grown in a ‘deficient’ medium consisting solely of Hank's salt solution. Treatment of cells after 48 hours in deficient medium with the cationic dye, mepacrine, resulted in an altered formation of lysosomes. Cells grown in full medium form dense, multi-vesiculated lysosomes in response to mepacrine. Cells grown in deficient medium form large electron lucent vacuoles containing peripherally located dense globules. The significance of the observations in relation to the deficiency of the medium is discussed.
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  • 109
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    Cell & tissue research 147 (1974), S. 259-269 
    ISSN: 1432-0878
    Keywords: Nerve endings ; Hair ; Rat ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Palisade-shaped nerve endings of the small normal hairs of the rat snout were examined with the electron microscope (fixation by perfusion). The terminals are located inside the ‘glassy membrane’ in the area of the neck of the hair root. The 10–20 radially arranged terminal axons are in direct contact with the basement membrane of the epithelium of the external root sheath. The axons are surrounded on all sides by leaf-shaped processes of the Schwann cells. The surfaces of these cell processes are marked by numerous vesicle-like invaginations (approx. 1000 Å dia.). Transverse sections from several areas of the palisadeshaped nerve endings are compared with longitudinal sections. In the upper area ‘empty’ vesicles (approx. 500–600 Å in diameter) occur, along with electron-dense vesicles (approx. 800–1100 Å in diameter); in the middle area, the axons are distended and contain accumulations of mitochondria.
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  • 110
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    Cell & tissue research 148 (1974), S. 237-245 
    ISSN: 1432-0878
    Keywords: Salivary gland ; Innervation ; Insect ; Monoamines ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The salivary glands of the moth, Manduca sexta (Insecta: Sphingidae), are unlike most other salivary glands in that they are innervated from one source only. Vital staining of nerves with methylene-blue reveals numerous fine nerves extending to the glands from the oesophageal nerve, a part of the stomatogastric or visceral nervous system. Light and electron microscopy confirm that only the fluid-secreting cells, confined to a discrete region in these glands, are innervated. Axons with or without glial wrappings are found in intercellular spaces between fluid-secreting cells. Axons lacking a glial sheath contain, after glutaraldehyde-osmium tetroxide fixation, large granular and small agranular vesicles. In nerve endings in glands fixed with permanganate these smaller vesicles are granular, having the electron-dense cores characteristic of monoamine-containing neurons. These nerve endings with “synaptoid areas” are in close (“direct”) contact with the fluid-secreting cells.
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  • 111
    ISSN: 1432-0878
    Keywords: Microglia ; “M” cells ; Gliogenesis ; Neuropathology ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Electron microscopy of subependymal cells and microglia in rat neonatal spinal cord reveals the latter to be a distinctive group of non-neuronal elements characterized by pronounced heterochromatin nuclei, many free ribosomes and rosettes, hour-glass shaped mitochondria, a moderately dense, granular cytoplasmic matrix, lipid vacuoles and a wide variety of lysosomes. Some examples are elongated and ameboid in appearance or may contain phagocytic vacuoles. Transitional forms between subependymal cells, or any other nonneuronal forms, and microglia were not observed. Ultrastructural features displayed by microglia are also strikingly characteristic of the “M” cells (Matthews and Kruger, 1973a, b) encountered in zones of thalamic degeneration two to three weeks following cortical ablation of adult rabbits. During the first and second postoperative weeks, “M” cells closely resemble the agranular leukocytes accumulating in the perivascular space of vessels coursing within the zones of degeneration. This fact, together with documentation of penetration of the vascular external lamina by elements of similar morphology, indicates a mesodermal origin for some “M” cells. The microglia of normal CNS and “M” cells of pathologic neural tissue are sufficiently similar, both in morphology and apparent function, to warrant consideration of a mesodermal origin for the microglia of neonatal CNS and a number of criteria to substantiate this concept are presented.
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  • 112
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    Cell & tissue research 149 (1974), S. 1-20 
    ISSN: 1432-0878
    Keywords: Axon sprouts ; Regeneration ; Dorsal column lesion ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A graded series of changes occur around lesions to the central nervous system. In the present investigation three zones were distinguished caudal to a lesion of the dorsal columns in the rat, In Zone I near the lesion, necrosis and cellular disintegration are followed by phagocytosis, and the development of a loose connective tissue matrix. Here Schwann cells proliferate and envelope axon sprouts in a similar fashion to those in developing of regenerating peripheral nerve. Zone II includes the proximal segment of nervous tissue containing normal appearing axons in continuity with parent nerve cells. Here an initially severe edematous condition is followed by growth and proliferation of astrocytes. Axon sprouts are present in the transitional Boundary Zone the first day following a lesion. They continue to grow and are most numerous at one week. By two weeks axons have apparently disappeared from many parts of Zone I and degeneration of parent axons and retraction clubs is advanced in Zone II. The reasons for axon involution are not known but do not appear to be related to the development of a glial scar.
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  • 113
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    Cell & tissue research 148 (1974), S. 417-429 
    ISSN: 1432-0878
    Keywords: Kidney ; Sexual segment ; Natrix natrix ; Histochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The sexual segment of the kidney of Natrix natrix has been investigated cytochemically, light microscopically and ultrastructurally. The sexual segment, which seems to be an important accessory sexual organ, has a single layer of a columnar epithelium. The epithelial cells are filled with large secretion granules of a wide range of electron densities. Cytochemical reactions for neutral and acid mucosubstances are negative, but the cells show a strong positive staining for phospholipids. Within the cells of the sexual segment we have localised by histochemical means several hydrolases and oxydoreductases, which reflect enzyme activities of the glycolytic pathway, the citrate cycle, and related metabolic pathways. The activities of the hydrolytic enzymes acid phosphatase, acetylcholinesterase and indoxylacetate esterase are remarkably high within the epithelial cells. Furthermore it was found that the sexual segment tubules possess contractile elements which extends over the basal surface of the epithelial cells. These contractile cells exhibit a very high activity of alkaline phosphatase. Single unmyelinated axons are located between the contractile elements and the basal lamina of the sexual segment cells. The functional significance of the sexual segment structures is briefly discussed.
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  • 114
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    Cell & tissue research 148 (1974), S. 493-497 
    ISSN: 1432-0878
    Keywords: Testicular interstitial cells ; Dog ; Filaments ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the dog testicular interstitial cells the cytoplasmic filaments are occasionally arranged in large bundles piled closely in an extensive area adjacent to the Golgi region in the cytoplasm. Some of the large bundles show conspicuous circular or spiral configurations which are composed of elaborate arrangements of both circular and longitudinal filaments and accompany tubules of agranular endoplasmic reticulum running parallel to the longitudinal filaments.
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  • 115
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    Cell & tissue research 150 (1974), S. 95-105 
    ISSN: 1432-0878
    Keywords: Mucosal mast cells ; Rat ; Compound 48/80 ; Degranulation, Release ; Light microscopy ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Mast cells in the tongue and lamina propria of the duodenal mucosa, representing two cell types with different morphological, histochemical and functional properties have been studied under the electron microscope. Both cell types were found to contain similar moderately electron dense and homogeneous granules surrounded by a tight membrane constituting the basic ultrastructural characteristics of mast cells. The mucosal mast cells, however, contained fewer granules per cell and the individual granules often exhibited considerable variation in size. In addition the mucosal mast cells, unlike those of the tongue, peritoneum and skin, had a smooth plasma membrane lacking microvilli and possessed irregularly shaped or lobulated nuclei. In the tongue mast cells, administration of Compound 48/80 caused the formation of vacuoles around the granules, expulsion of granules from the cells and disintegration of the granular matrix, but no changes that could be attributed to 48/80 could be found in the mucosal mast cells.
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  • 116
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Mitochondria ; ACTH ; Stereology ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects of a chronic administration of ACTH (up to 36 consecutive days) on the mitochondria of the zona fasciculata of the rat adrenal cortex were investigated by stereologic techniques. It was found that, while the volume of the mitochondrial compartment significantly increases in relation to the duration of treatment, the size and number of mitochondria display a different pattern. Up to the 9th day of hormone treatment mitochondria significantly increase in volume, whereas their number per cell is only slightly increased. After 12 days of ACTH-treatment there is a tremendous increase in the number of organelles per cell, resulting in a significant decrease in their average volume. After 24 and 36 consecutive days of treatment the number of mitochondria per cell as well as their average volume both show a slight but significantly constant increase. The hypothesis that ACTH controls the processes of growth and division of adrenal mitochondria is discussed in the light of evidence indicating that mitochondria contain a complete genetic apparatus largely independent of nuclear control.
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  • 117
    ISSN: 1432-0878
    Keywords: Rat anterior pituitary ; FSH and LH-gonadotrophs ; Luteinizing releasing hormone ; “Signet cells” ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The action of luteinizing releasing hormone (LH-RH) on FSH and LH-gonadotrophs from the anterior pituitary glands of normal rats has been studied with electron microscopy. After 15 min. incubation with LH-RH, LH cells showed secretory granules undergoing exocytosis, but FSH did not appear to release secretory products. On the other hand, incubations with the releasing hormone for 3 and 6 hr stimulated exocytosis from both FSH and LH-gonadotrophs. Of more interest was the finding that FSH cells appeared as typical “signet cells” of castration when glands were incubated for 3 and 6 hr with the releasing hormone. The appearance of such “signet cells” was prevented if puromycin was added to the medium together with LH-RH.
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  • 118
    ISSN: 1432-0878
    Keywords: Lipofuscin ; Phagocytosis ; Vacuolization ; Capillary endothelium ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Dimethylaminoethyl p-chlorophenoxy acetate (80 mg/kg body weight) was administered (i. m.) to guinea pigs for 30 to 56 days. Electron microscopic examination of the hippocampus, mid-brain reticular formation and the area postrema revealed marked diminution in the electron density of the pigment granules and vacuolization. This type of lipofuscin was detected in some phagocytic cells and in the capillary endothelium. Conspicuous vacuolization of the capillary wall was discernible. These changes were not observed in the “control group” of animals.
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  • 119
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    Cell & tissue research 150 (1974), S. 425-442 
    ISSN: 1432-0878
    Keywords: Glandula submandibularis (Mouse) ; Acinar ultrastructure ; Cell types ; Development ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The development of the submandibular gland of the mouse was studied by means of electron microscopy, from the 14th day of gestation up to birth. In the first two days the acini are solid and their cells contain polyribosomes and a few lamellae of endoplasmic reticulum. Beginning with the 16th day secretory granules appear and rapidly fill an increasing number of cells. The different electron density of the granules makes it possible to distinguish 1. two types of granules, dense and pale, and sometimes intermediate ones, 2. “polymorphic” granules. The latter consists of electron dense and electron pale parts combined in different configurations. The possible significance of the various types of granules is discussed.
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  • 120
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    Cell & tissue research 150 (1974), S. 409-423 
    ISSN: 1432-0878
    Keywords: Synaptic organization ; Trochlear nucleus ; Cat ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Two distinct types of neuron in the cat trochlear nucleus (one large, one small) are described, the α- and γ-motoneurons, respectively. Four types of terminals are observed which establish axo-dendritic synapses. Two of them (Types I and II) perform axo-somatic synapses as well. Terminals en passant (Types I and II) are predominant. The Type I terminal is long and slender with a characteristic distribution of the axoplasmic organelles and the unique feature of a relative narrowing of the synaptic cleft as compared to the width of the neighboring extracellular space. Its vesicle population is pleomorphic and a conspicuous glial barrier surrounds the synaptic zones. The Type II terminal differs slightly from Type I, revealing a wider synaptic cleft and lacking a characteristic distribution of the axoplasmic organelles. The type III terminal is rarely observed performing axo-somatic synapses, but is a common finding in the neuropil. Post-junctional dense bodies are often present in its axodendritic synapses. The Type IV nerve terminal performs axo-dendritic synapses and is characterized by a rich content of large granulated vesicles. Axo-axonal synapses are observed only very rarely. The synaptic organization of the feline trochlear nucleus is compared with the synaptic morphology of the oculomotor nuclei of inframammalian species (Waxman and Pappas, 1971). In addition to certain similarities (e.g., richness of synapses en passant), significant differences are encountered: the present study provides no morphological evidence for electrotonic transmission in the trochlear nucleus of cat.
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  • 121
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    Cell & tissue research 150 (1974), S. 481-492 
    ISSN: 1432-0878
    Keywords: Seminiferous tubule, ovine ; Lamina propria ; Development ; Endocrine factors ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the lamina propria in the ovine seminiferous tubule was studied from 54 days (postcoitum) fetuses up to sexual maturity. In young animals (aged about two months) the effect of hypophysectomy and/or hormones was also analyzed. Initially, large areas of the lamina propria already show signs of morphological differentiation. The non cellular component is a single or sometimes double lamella. Outwardly, the cellular component is represented by rounded connective tissue cells or by elongated cells, exhibiting 80 Å filaments in the cytoplasm and arranged in 3 to 4 layers. By the first week after birth, the non cellular component is formed by 8 to 10 lamellae and the cellular component shows typical contractile cells, the fibroblasts being now located only in the periphery. Basically, the same aspect is found in the adult ram, thus differing from the more extensively studied prototypes of lamina propria architecture of rodents or primates. In as much as the sheep lamina propria differentiates precociously, probably induced by fetal testicular hormones, it is relatively insensitive to hypophysectomy or hormonal substitution. Hypophysectomy and cyproterone acetate administration cause intracytoplasmic lipid deposition in the contractile cells, the other components being not changed. Some questions are raised concerning the role of this peculiar lamina propria in the function of the blood-testis barrier.
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  • 122
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    Cell & tissue research 150 (1974), S. 545-552 
    ISSN: 1432-0878
    Keywords: Skin, rat ; Cytology ; Innervation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Neural elements within the parenchyma of the sebaceous gland have not been reported previously. Nerve endings have been observed only in the connective tissue surrounding the gland or in close association with the undifferentiated basal cells. In this study, electron microscopy revealed the possible presence of nerve endings (or terminal portions of neural elements) in the suprabasal level of functional sebaceous glands of pinnae of white rats. Morphologically, there are two distinct types of nerve endings. Type 1 is bordered by a membrane of relatively irregular contour and contains a single mitochondrion, various-sized vesicles, numerous microtubules, fine neurofilament-like fibrils, and occasional ribosome-like granules. Type II is also bordered by a membrane, but its contour was relatively smooth and rounded. Moreover, Type II contains many mitochondria, varying in size, density, and the arrangement of cristae. While ribosome-like granules are scattered throughout the structure in relative abundance, there are scarcely any fine neurofilament-like fibrils or microtubules. Whether these two structures are sensory or autonomic fibers could not be determined by electron microscopic examination.
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  • 123
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    Cell & tissue research 151 (1974), S. 93-101 
    ISSN: 1432-0878
    Keywords: Acrosome reaction ; Bankia australis ; Teredo ; Fertilization ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the acrosome reaction in the sperm of the teredo, Bankia australis, is described. In brief, the reaction consists of three phases: (a) formation of a bleb and membrane fusion, (b) disappearance of the longitudinally oriented fibrils, and (c) outward flaring and disappearance of the osmiophilic granule. The osmiophilic granule appears to consist of prism-like structures. The axial rod never lengthens during the acrosome reaction.
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  • 124
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    Cell & tissue research 151 (1974), S. 281-292 
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Mitochondria ; ACTH ; DNA-synthesis ; Autoradiography ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects of a chronic ACTH administration (up to 12 consecutive days) on the 3H-thymidine uptake by the mitochondrial compartment of rat adrenal zona fasciculata were investigated by high resolution autoradiography, and compared with the changes in volume and number per cell of these organelles induced by the hormonal treatment. Up to the 9th day of treatment there is a significant increase in the tracer incorporation into adrenocortical mitochondria which is coupled with a significant increase in the volume of the organelles. After 12 days of hormone administration a significant decrease in the 3H-thymidine mitochondrial uptake is found, which is associated with a conspicuous increase in the number of mitochondria per cell and a net decrease in their average volume. The data are discussed in the light of evidence indicating that mitochondria possess a genetic apparatus largely independent of nuclear control. It is hypothesized that ACTH controls the growth and proliferation of adrenocortical mitochondria and that the mechanism of this action of ACTH involves stimulation of the mitochondrial DNA synthesis.
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  • 125
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    Cell & tissue research 152 (1974), S. 69-92 
    ISSN: 1432-0878
    Keywords: Pituitary ; Freshwater stickleback ; Morphometry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A new approach to the ultrastructure of fish pituitary glands is presented. A morphometric analysis of the cell types in the pituitary gland of the adult, winter, fresh-water stickleback, Gasterosteus aculeatus form leiurus, reveals differences between both the relative and absolute volumes of the various organelles in different cell types. The morphometric data on the relative volumes of the organelles, together with section profile diameters of the secretory granules and information on the surface area: volume ratio of the nuclei are then used to build “reconstruction drawings” of “average” cells. A distinction is made between the ultrastructural description and identification of cell types.
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  • 126
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    Cell & tissue research 152 (1974), S. 175-183 
    ISSN: 1432-0878
    Keywords: Cell aggregation ; Spinal ganglia ; Cell cultures ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Dorsal root spinal ganglia of chick embryos were trypsinized and the cellular components isolated. Suspensions of these cells reaggregate. During this process satellite glial cells and neurons established intimate contacts. The reconstructed glial envelopes around the neurons are morphologically similar to the ones formed in the intact animal during development. The formation of the characteristic glial-neuronal relation is an example of specific cell recognition.
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  • 127
    ISSN: 1432-0878
    Keywords: Phagocytosis ; Large foreign bodies ; Cryptococcus neoformans ; Tissue culture ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The yeast Cryptococcus neoformans may develop under certain conditions a large polysaccharide capsule 50–100 μM in diameter and therefore cannot be phagocytosed by either polymorphonuclear cells (PMN's) or mononuclear phagocytes (MN's). The cellular defense mechanism — in various animals — against the yeast is composed by formation of ringlike structure of PMN's or MN's cells which surround the C. neoformans. Ring structures develop either in vivo or in vitro in tissue culture; destruction of the yeast occurs within 36–72 hours. Several hydrolases, such as acid phosphatase, β-glucuronidase and non-specific esterase were found to be released from the phagocytic cells into the enclosed yeast. Considerable reduction of NBT used as a marker for oxidative activity was observed in MN rings at contact regions of the MN cells and the yeast. Electron microscopic studies indicate that the phagocytic cells in the ring structure have many pseudopodes penetrating into the polysaccharide capsule of the yeast. Disintegration of the capsule was observed as well as phagocytosis of its material. A possible analogy between normal phagocytosis of small-sized bodies and the ring structure obtained when large bodies are involved is discussed.
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  • 128
    ISSN: 1432-0878
    Keywords: Branchiostoma ; Kölliker's pit ; Hatschek's pit ; Wheel organ ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Kölliker's and Hatschek's pit and the wheel organ in the head region of Amphioxus have been studied with the electron microscope. Kölliker's pit is lined by ciliated cells lacking specific ultrastructural characteristics which might suggest an olfactory function. No nerve terminals have been found near this structure. The wheel-organ consists of tall ciliated cells, which occasionally have been found to be innervated and which are clearly marked off the rest of the epithelial lining of the oral cavity. The epithelium of Hatschek's pit again is ciliated and possesses markedly euchromatin rich nuclei. In the area of Hatschek's pit numerous epithelial cells have been observed which possess accumulations of small granules and vesicles in their basal cytoplasm. Such basally granulated cells occur in the immediate neighbourhood of blood spaces of the glomus and other vessels; the connective tissue between blood and epithelium is loosened up or has completely disappeared. The question of homology of the structures investigated with the olfactory groove and hypophysis of vertebrates is briefly discussed.
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  • 129
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    Cell & tissue research 153 (1974), S. 449-464 
    ISSN: 1432-0878
    Keywords: Juxtaglomerular apparatus ; Bufo bufo ; Macula densa ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of the juxtaglomerular apparatus in the toad, Bufo bufo was investigated.—It is suggested that the granules in the media cells of the afferent arteriole are formed from the Golgi apparatus. Many granules have a content of lamellar material. The media cells do not show the ultrastructural features of active secretory cells. In the media cells, the myofilaments are situated near the vascular lumen. The other cell organelles, including the granules, are preferentially located at the opposite pole of the cell in the neighbourhood of the macula densa cells and the adventitial nerve fibres. In these regions the media cells show many pinocytotic vesicles. The nerve fibres innervating the juxtaglomerular cells are non-myelinated and their varicosities contain dense core vesicles. The basement membranes of media cells and adjacent macula densa cells occasionally fuse, which may indicate a functional relationship between these cells.
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  • 130
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    Cell & tissue research 154 (1974), S. 1-16 
    ISSN: 1432-0878
    Keywords: Ventricle ; Tanycytes ; Monoamine transport ; Autoradiography ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary This investigation has dealt with a light and electron microscopic autoradiographic analysis of the median eminence of the rat following intraventricular infusion of 3H-dopamine. This study has demonstrated that 3H-dopamine, once infused into the mammalian cerebral ventricular system, is rapidly and selectively absorbed by tanycytes and transported to the contact zone within 5 minutes after ventricular infusion. Certain axon terminals in the ependymal, hypendymal, and palisade-contact zones selectively sequester 3H-dopamine as do subpopulations of arcuate neurons. This picture of intense labelling of neurons and axon terminals is discussed with respect to monoaminergic re-uptake mechanisms. Uptake and transport of 3H-DA by tanycytes is discussed.
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  • 131
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    Cell & tissue research 154 (1974), S. 103-108 
    ISSN: 1432-0878
    Keywords: Plasma membrane specialisations ; Developing neurons ; Xenopus laevis ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Membrane specialisations have been found on neurones in embryos of the clawed toad Xenopus laevis. The specialisations have been called dense membrane knobs and consist of an outpushing of the plasma membrane with a slight increase in its density. The out-pushing forms a spherical knob with an amorphous dense core and a total diameter of 500 to 600 Å. The knobs are found on axons and dendrites both in the spinal cord and peripherally.
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  • 132
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    Cell & tissue research 154 (1974), S. 543-545 
    ISSN: 1432-0878
    Keywords: Epitheliomuscular cells ; Brachiopoda Lingula ; Acrania ; Branchiostoma ; Phylogeny ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Epitheliomuscular cells largely corresponding to those of cnidarians have been found in the mesenteria of Lingula and in various coelomic channels of Branchiostoma. They are characterized by basal extensions containing thin and thick myofilaments. In Lingula they also bear an apical cilium.
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  • 133
    ISSN: 1432-0878
    Keywords: Salivary glands ; Drosophila ; larval and prepupal ; Electron microscopy ; Histochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A major function of the larval salivary glands of Drosophila melanogaster is known to be the production of a mucopolysaccharide that serves as an adhesive during puparium formation. In order to localize the mucosubstances during development substrate histochemical methods were used, and the site of acid phosphatase was demonstrated by the ultrahistochemical lead-salt method. It could be shown that the “glue”-granules in the corpus cells of larval salivary glands as well as the large secretion vacuoles in the prepupal corpus cells give a positive β-amylase-resistent PAS-reaction, which indicates neutral mucosubstances. Granular PAS-positive deposits in the larval and prepupal collum cells were reduced after preincubation with β-amylase and may represent glycogen, which has also been seen in electron micrographs of these cells. The Hale-reaction gave a weak indication that acid mucosubstances are present in the larval “glue” granules and in the large prepupal secretory vacuoles. After digestion of sialic acid with α-neuraminidase the weak indication was absent showing that the acid mucosubstances had been sialomucines. Ultrahistochemical demonstration of acid phosphatase indicated the presence of this enzyme in Golgi fields and lysosomal structures. Acid phosphatase seems to be missing in the large secretion vacuoles of the prepupal salivary gland. It is concluded, that the large vacuoles in the corpus cells of prepupal salivary glands represent a secretion product, obviously a mucosubstance. The lysosomal structures, containing acid phosphatase, may be accumulated in preparation for the autolysis of the gland which begins about two hours after the pupal moult, i.e. 15 hours after puparium formation.
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  • 134
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    Cell & tissue research 155 (1974), S. 127-134 
    ISSN: 1432-0878
    Keywords: Organ of Bellonci ; Carcinus maenas (Crustacea, Decapoda) ; Sensory and secretory function ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The organ of Bellonci of Carcinus maenas is made up of onion bodies and secretory cells. The onion body consists of a distal segment, of membranous whorls and granules, and a proximal nuclear cell body. They are joined by a modified double ciliary junction. Both a sensory and secrtory function is suggested. The secretory cells fall into two groups based on size, shape and organelles. Their presence suggests a secretory function to the organ of Bellonci.
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  • 135
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    Cell & tissue research 156 (1974), S. 103-112 
    ISSN: 1432-0878
    Keywords: Dorsal tail tubercle ; Urodela ; Skin ; Hedonic glands ; Electron microscopy ; Enzyme histochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Dorsal tubercle and skin of Mertensiella caucasica have been investigated with the electron microscope and enzyme histochemical methods. The epidermis of the tubercle consists of 8–9 cell layers, that of normal dorsal skin of 5–6. The tubercle is filled with large mucous glands which are surrounded by an almost complete layer of smooth muscle cells (myoepithelial cells). Their glandular cells undergo cyclical changes and are characterized by specific secretory granules, which differ from those of the relatively small mucous glands of the normal dorsal skin. In the connective tissue of the tubercle a relatively rich supply of nerve fibres has been found, which in part contain synaptic and dense core vesicles or accumulations of mitochondria. In the normal dorsal skin nerve fibres occur less frequently. The following enzymes have been demonstrated in the mucous glands of the tubercle: SDH, acid phosphatase, unspecific esterases, E 600 resistant esterase. The tubercle seems to stimulate the female cloaca chemically and mechanically.
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  • 136
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    Anatomy and embryology 141 (1973), S. 251-264 
    ISSN: 1432-0568
    Keywords: Closure of neural tube ; Cell necrosis ; Normal mouse embryos ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Spontaneous cell death in the developing brain of 8.5–9 day old mouse embryos has been investigated with the electron microscope. Before closure of the neural tube, areas of cell death are found at the neuro-somatic junction. After closure of the neural tube degenerating cells are found in the dorsal midline of the prospective diencephalon. Ultrastructurally, cell degeneration is marked by chromatin condensation, increase in electron density of the structures in the cytoplasm and, in later stages, by a marked pycnosis of the dying cell. After fragmentation, the necrotic material as well as entire pycnotic cells are phagocytized and digested by cells of the neuroepithelium. An invasion of macrophages has not been observed. The significance of cell necrosis is discussed in relation to the normal formation of the neural tube and to the occurrence of certain induced malformations (exencephalies).
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  • 137
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    Anatomy and embryology 142 (1973), S. 341-358 
    ISSN: 1432-0568
    Keywords: Glycoproteid containing cells ; Microglia ; Brain development ; Chicken ; Light microscopy ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Zur Zeit der embryonalen und fetalen Entwicklung des Hühnchens treten vorübergehend runde, vacuolisierte, freie Zellen auf, die sich durch starken Gehalt und Glykoproteiden auszeichnen. Nachweis mit der Perjodsäure-Bisulfit-Aldehydthionin-Methode nach Specht (1970). Der Vergleich von Entwicklungsstadien zwischen dem 4. und dem 17. Bebrütungstag zeigt, daß die Zellen im Mesenchym entstehen und mit großer Wahrscheinlichkeit sowohl über das Ventrikelsystem als auch über die äußere Hirnoberfläche in das Gehirn einwandern. Die Zellen werden hauptsächlich in aufgelockerten, flüssigkeitsreichen Hirngebieten gefunden. Vermutlich geht die vorübergehende Auflockerung dieser Hirngebiete, die als Reservevolumen für nachfolgende histogenetische Wachstumsprozesse (Axonwachstum, Myelinisierung) verstanden wird, auf die Träger der PBA-positiven Zellen zurück (Ausschleusung von Glykoproteiden aus den PBA-positiven Zellen). Im gleichen Zeitraum bilden auch Ependymzellen Glykoproteide.
    Notes: Summary Round, vacuolated amoeboid cells with a high content of glycoproteids appear temporarily during the embryonic development of the chicken's brain. The cells were identified by the periodic-acid-bisulfit-aldehydthionine-method (Specht, 1970). A comparison of the developmental stages (4.–17. day of incubation) of the cells show that they originate in the mesenchym and probably immigrate by way of the ventricles as well as from the outer brain surface. The cells are mainly found in brain areas containing large, loosely structured extracellular spaces. The large extracellular gaps of these areas are probably developed in response to glycoproteid secretion by PBA-positive cells, as a preparatory measure for subsequent histogenetic growth processes (axon growth with myelinisation). At the same time glycoproteids are also produced by ependymal cells.
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  • 138
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    Anatomy and embryology 140 (1973), S. 11-17 
    ISSN: 1432-0568
    Keywords: Electron microscopy ; Cross-striated fibers ; Rootlets ; Midpiece ; Fish spermatozoa
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In the 45 μ long midpiece of the spermatozoon of Pantodon buchholzi nine helical, cross-striated fibers run from one end to the other and parallel nine helical mitochondrial threads; both fibers and mitochondrial threads surrounding the axoneme. The fibers have a major period about 750–900 Å and are very similar to ciliary rootlets and other cross-striated structures in terms of which they are discussed.
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  • 139
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    Anatomy and embryology 142 (1973), S. 91-101 
    ISSN: 1432-0568
    Keywords: Myotendinous junction ; Myxine and rat ; Lamina densa ; Plasma membrane ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Myotendinous junctions in the parietal muscle of the Atlantic hagfish (Myxine glutinosa, L.) and in the diaphragm of rat were studied with the electron microscope. The ends of muscle fibers posses deep tube-like invaginations and also finger-like processes. Terminal I-filaments of the myofibrils attach to the plasma membrane of the invaginations. Collagen fibrils of the tendon attach to the external aspect of the lamina densa. The lamina densa and also collagen fibrils continue into the invaginations. Specializations are present in the zone between the plasma membrane and the lamina densa of the invaginations, being most conspicuous in Myxine. These consist of 60 Å wide spine-like or thread-like profiles 150 Å apart, connecting with both the outer leaflet of the plasma membrane and the lamina densa. Spatially, they form parallel circular ridges oriented transversely in stacks along the invaginations. Similar spine-like profiles are also discernible in the invaginations of rat muscle fibers. In rat, however, their spatial arrangement (ridges or fibrils) remains unknown. These specializations may serve to attach the lamina densa to the plasma membrane, and may be important for the transmission of force from muscle fibers to tendon.
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  • 140
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    Anatomy and embryology 143 (1973), S. 81-94 
    ISSN: 1432-0568
    Keywords: Electron microscopy ; Mechanoreceptors ; Skin ; Reptiles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Lamellierte Receptoren in der Haut von Reptilien werden licht- und elektronenmikroskopisch beschrieben. Rekonstruktionen aus Schnittserien haben gezeigt, daß sie 1. als freie lamellierte Endigungen, 2. als lamellierte eingekapselte Endigungen und 3. als lamellierte eingekapselte Endigungen mit Kapselraum vorkommen. Sie haben eine Spindelform und können bis zu 0,5 mm lang sein. Die innere Lamellierung des eingekapselten Receptors mit Kapselraum vom Kaiman zeigt strukturelle Ähnlichkeiten zur inneren Hülle des Vater-Pacinischen Körperchens. Das Lamellensystem der Receptoren von Natter und Waran zeigt Parallelen zum Bau des inner core des Herbstschen Körperchens der Vögel. Die lamellierten Receptoren bilden einen regelmäßigen Bestandteil der sensiblen Innervation von Tastpunkten der Reptilienhaut.
    Notes: Summary Lamellated receptors in the skin of reptiles were studied with the light and electron microscope. As revealed by reconstructions of serial sections, there are three types of lamellated receptors: 1. lamellated free endings, 2. lamellated encapsulated endings and 3. lamellated encapsulated endings with a “fluid-filled” capsule space (outer core). The spindle shaped endings have a length of up to 0.5 mm. In Caiman, the lamellae (inner core) of the encapsulated receptor with a capsule space have a structure similar to that of the inner core of the Vater-Pacinian corpuscle. The lamellation (inner core) of the terminals of Natrix and Varan shows similarities with the inner core of the Herbst corpuscle. Lamellated receptors usually form an element of the sensory innervation of touch papillae in the reptile skin.
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  • 141
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    Anatomy and embryology 139 (1973), S. 207-216 
    ISSN: 1432-0568
    Keywords: Caudal neurosecretory system ; Ontogenesis ; Electron microscopy ; Teleost fish
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ontogenesis of the urophysial system (caudal neurosecretory system) in the roach (Leuciscus rutilus) was ultrastructurally analyzed. In newly hatched spawns the urophysial components are differentiated in the form of neurosecretory perikarya, axons and terminals and display the characteristics of a functional system although the neurohemal area is not developed. It is assumed that the system is active simultaneously with the preopticohypophysial system during ontogenesis. On the contrary, organogenesis of the urophysis is late, and only at the 14 mm stage do the neurosecretory axons first penetrate the meninx to participate in the formation of the organ. Assumed aminergic cell types associated with the urophysial system are differentiated at the time of hatching, thus indicating a functional relationship. A secretory ependyma releasing its granules into the central canal is described.
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  • 142
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    Anatomy and embryology 141 (1973), S. 55-75 
    ISSN: 1432-0568
    Keywords: Heart ; Endothelial cushion ; Fusion ; Cell interaction ; Electron microscopy ; Chick embryo
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In an investigation concerning the so-called “fusion” of the atrioventricular endocardial cushions in the heart of the chick embryo the following facts were established: 1. The endocardial cushions in the chick embryo do really fuse. However, the region of fusion is less extensive than is generally accepted. 2. No regressive cellular changes were observed in the fusing endothelia with light or electron microscopy. On the contrary, mitotic activity and possibly even erythroblastic transformation were observed in the endothelium as well as in the subendothelial mesenchyme. 3. Under the light microscope, the process of fusion is characterized by interdigitation of the endothelial cells. In later stages the endothelial character of these cells disappears in such a way as to give rise to one single mesenchymal cushion mass. 4. Under the electron microscope the fusing endothelial cells form extremely long tonguelike cytoplasmic processes which protrude freely into the lumen where they may fuse with similar processes from other endothelial cells of the same side. In this way small compartments become segregated from the lumen. the plasma membrane of the processes may also fuse with the plasma membrane of the cell from which they originate. Alternating persistence and disappearance of the plasma membrane gives rise to many membrane-lined intracellular vesicles. 5. The numerous myelin figures found in and between the endothelial surfaces appear to represent the blind and empty membranous linings stripped off from cytoplasmic processes. The intracellular myelin figures are probably incorporated into the cells in the same way as described above. Apart from this form of endocytosis, signs of conventional micropinocytotic activity are present. 6. The density of endoplasmic reticulum suggests intensified protein synthetic activity, in which membrane-bound as well as free ribosomes and polysomes seem to participate. Moreover, increased mitochondrial density in the cells in the fusion region is evident. 7. Specialized junctional complexes between the plasma membranes in the form of desmosome-like junctions are relatively scarce. 8. Fusion of cytoplasmic tongues of endothelial cells with adjacent endothelial cells of the same side or of the opposite side is responsible for the exchange of large quantities of cytoplasma between endothelial cells and, as a consequence, for displacement of cell boundaries without loss of cell individuality.
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  • 143
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    Anatomy and embryology 143 (1973), S. 1-12 
    ISSN: 1432-0568
    Keywords: Neuromuscular junction ; Development ; Cholinesterases ; Muscle ; Immobilization ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Immobilization of the tibialis anterior muscle of the newborn rat was caused by amputation of the hind limb at the talocrural joint. Subsequent muscular atrophy was measured by weighing the muscle and the myoneural morphogenesis in the disused muscle was studied in light and electron microscope. The acetylcholinesterase (AChE; E.C.3.1.1.7) and nonspecific cholinesterase (Ns. ChE; E.C.3.1.1.8) activity at the myoneural junction was followed histochemically. It was observed that the myoneural morphogenesis proceeded normally in the immobilized and atrophied muscle. Cholinesterase activities at the developing myoneural junction were identical on both the immobilized and the contralateral control side. The myoneural morphogenesis may be solely controlled by the nerve since, at the light of the present observations, the abnormally diminished function of the muscle seems to have no effect on the myoneural development.
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  • 144
    ISSN: 1432-1076
    Keywords: Phenylketonuria ; Seizures ; Isoniazid ; Jaundice ; Electron microscopy ; Degeneration of organelles in liver cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Bei einem jordanischen Kleinkind, das wegen einer Phenylketonurie mit cerebralen Krampfanfällen seit 1 Jahr mit Primidon und Ospolot behandelt und seit 7 Monaten mit einer phenylalaninarmen Diät unter Zusatz eines Aminosäurengemisches ernährt wurde, entwickelte sich nach 3 monatiger INH-Medikation ein hepatocellulärer Arzneimittelikterus. Dieser erwies sich klinisch und histologisch als reine Form einer toxischen Hepatose ohne entzündliche Symptome. Die elektronemmikroskopische Untersuchung von Leberbiopsiematerial 2 Wochen nach dem Höhepunkt des Ikterus (28 mg% Gesamtbilirubin im Serum) erlaubte den Nachweis eines intracellulären Transportdefektes des bereits konjugierten Bilirubins in den Leberepithelien. Das Pigment wurde analog dem Dubin-Johnson-Syndrom in peribiliären Lysosomen gespeichert. Weitere für die Pathogenese aufschlußreiche Befunde wurden an den Organellen der Hepatocyten erhoben: Hydropische Schwellung des hypertrophierten glatten endoplasmatischen Reticulums bei gleichzeitiger Reduktion des rauhen endoplasmatischen Reticulums, Glykogenschwund und Degeneration der Mitochondrien. Bei der Kontrollbiopsie nach 1/2 Jahr waren alle Befunde bis auf die lysosomale Speicherung normalisiert.
    Notes: Abstract After being treated with isonicotinic acid hydrazine (INH) for 3 months a 3-year-old Jordanian boy with phenylketonuria developed severe hepatocellular jaundice. In addition to INH the patient had received Primidone and Ospolot® for 1 year and a PKU diet for 7 months without any side effects. The liver biopsy 2 weeks after the peak of jaundice revealed no signs of hepatitis on light microscopy. An electron microscope investigation showed a defect in the intracellular transport system of bilirubin; bile pigment was stored in peribiliar lysosomes in the same way as in the Dubin-Johnson Syndrome. The smooth endoplasmatic reticulum was increased and vacuolized, whereas rough endoplasmatic reticulum, mitochondria, and glycogen were reduced. In a control biopsy nearly 6 months after the jaundice the morphologic alterations of the liver had normalized with the exception of the lysosomal changes.
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  • 145
    ISSN: 1433-8580
    Keywords: Spirolactone ; Aldosterone ; Zona glomerulosa ; Electron microscopy ; Spirolacton ; Aldosteron ; Zona glomerulosa ; Ultrastruktur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Wirkung von Spirolacton auf die Zona glomerulosa des Hundes wurde licht- und elektronenmikroskopisch untersucht. Die an Kontroll- und Versuchstieren erhobenen Befunde werden miteinander verglichen. 1. Lichtmikroskopisch werden bei Kontroll- und Versuchstieren zwei unterschiedlich stark anfärbbare Zelltypen beobachtet. Bereits nach 10tägiger Behandlung mit Spirolacton läßt sich eine beträchtliche Dickenzunahme der Zona glomerulosa nachweisen. Mit den angewandten Färbemethoden lassen sich in den beiden Zelltypen keine den „Spironolacton-Körpern“ ähnliche Einschlüsse darstellen. 2. Elektronenmikroskopisch zeigen die beiden Zelltypen deutliche Unterschiede in der Feinstruktur; wegen ihrer unterschiedlichen elektronenoptischen Dichte werden sie als helle und dunkle Zellen bezeichnet. Im Cytoplasma der dunklen Zellen kommen 1–4 lamelläre Körper vor, die jedoch nicht den beim Menschen beobachteten „Spironolacton-Körpern“ ähnlich sind. Nach Behandlung mit Spirolacton weisen die hellen und die dunklen Zellen (einschließlich ihrer lamellären Körper) gegenüber Kontrolltieren keine feinstrukturellen Unterschiede auf. Es wird diskutiert, ob die hellen und dunklen Zellen in der Zona glomerulosa unterschiedliche Aktivitätszustände ein und derselben Zellart darstellen. Ebenso wird die mögliche Funktion der lamellären Körper im Vergleich zu den Ergebnissen anderer Autoren erörtert.
    Notes: Summary The effect of spirolactone on the zona glomerulosa was studied in dogs by light and electron microscopy. Results of untreated animals are compared with those pretreated with spirolactone for several days. Light microscopy in control as well as in experimental animals disclosed two different types of cells as far as their staining properties were concerned. With the staining techniques utilized in this study cellular inclusions, so-called spironolactone bodies as previously reported by others, were not seen. The width of the zona glomerulosa, however, was found to be significantly increased in treated animals. Electron microscopy revealed the two respective cell types to be definitely different. Due to their electron density they are referred to her as light and dark cells. Within the cytoplasm of the dark cells laminated inclusions were seen, ranging in size from 1 to 4 µm. These inclusions are thought to be not identical with socalled spironolactone bodies. Spirolactone did not affect the ultrastructural appearance of either light or dark cells, when compared with control, this is also true for the laminated inclusions. It is suggested that the light and dark cells represent the same type of cell at different activity levels. Finally, the functional significance of the laminated inclusions is discussed in view of findings reported elsewhere.
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  • 146
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    Cell & tissue research 136 (1973), S. 85-96 
    ISSN: 1432-0878
    Keywords: Liver ; Lampetra ; Physiological biliary atresia ; Electron microscopy ; Histochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A morphologic and histochemical study was carried out on the liver of larval and adult lampreys at the optical and electron microscopic level. In the larva the liver is composed of blind ending single cell thick tubules of hepatocytes. The tubular lumina provided with microvilli are morphologically comparable with the canalicular lumens of the higher species of animals. The cytoplasm of the hepatocytes contains numerous inclusions with heterogeneous appearance and crystalline material. The biliary system is composed of numerous bile ductules and ducts. In the adult lamprey, the biliary system has disappeared. The hepatocytes loose their tubular arrangement and the characteristic differentiation of their biliary pole. In contrast to previous reports in the literature the presence of bile pigment in the adult lamprey liver could not be demonstrated with any histochemical technique.
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  • 147
    ISSN: 1432-0878
    Keywords: Interstitial cells, genesis ; Hen's ovary ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Für die Zwischenzellen des Hühnerovars gibt es embryonal und post-embryonal bindegewebige und epitheliale Quellen. Die bindegewebigen Mutterzellen sind Mesenchymzellen und Fibrozyten, die epithelialen Mutterzellen sind Wandepithelzellen der Markstranglakunen und Epoophorontubuli. Kriterien zur Unterscheidung dieser vierfachen Abstammungsmöglichkeiten der Zwischenzellen werden angegeben.
    Notes: Summary The interstitial cells of the hen's ovary have two sources: connective tissue mother cells, which are mesenchymal cells or fibrocytes, and epithelial mother cells, which are wall epithelial cells of the medullary cord lacunae or of the tubuli of the epophoron. Criteria are provided for differentiating this fourfold genesis of the interstitial cells.
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  • 148
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    Cell & tissue research 139 (1973), S. 101-148 
    ISSN: 1432-0878
    Keywords: Infundibulum ; Rat ; Neuro-glial synapses ; Neuro-Vascular contacts ; Corticotropin-Releasing Factor ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung 1. Die Gefäßfortsätze von ependymalen und subependymalen Zellen bilden in der subependymalen Zone und in der Zona interna des Ratteninfundibulum mit Nervenfasern kompakte neuro-gliöse Faserbündel, die sich in der Zona externa aufzweigen. 2. In allen Zonen des Infundibulum kommen zwischen den Nervenfasern und den Gefäßfortsätzen zahlreiche neuro-gliöse Synapsen vor. In den Gefäßfortsätzen fällt die hohe Zahl an Mikrotubuli sowie die zahlreichen, vielgestaltigen Einschlüsse auf. 3. In der subependymalen Zone sind die Interzellularspalten an bestimmten Stellen außerordentlich weit. Sie haben eine kanalartige Beschaffenheit und enthalten feine Bündel von Nervenfasern. 4. Von den lateralen Anteilen des Infundibulum her erreichen Dendriten von Ganglienzellen des Nucleus infundibularis die Mitte des Infundibulum. In dieser Region sind axodendritische Synapsen anzutreffen. 5. Morphometrische Analysen der Nervenfaserendigungen der Zona externa von Normaltieren zeigen, daß die prozentuale Verteilung der nach Granulagröße differenzierten Nervenfaserklassen für Mitte und Seite der Zona externa etwa gleich ist. Zwischen der Größe der Elementargranula und der Anschnittfläche der zugehörigen Nervenfasern besteht eine direkte Beziehung. 6. Die Nervenfaserendigungen erreichen die Basalmembran des perikapillären Raumes fast ausschließlich im Bereich von gefäßwärts gerichteten Vorwölbungen der Zona externa. Das Ausmaß, in dem Nervenfasern im Vergleich zu den Gefäßfortsätzen von Ependymund Gliazellen den perivaskulären Raum erreichen, ist medial weitaus größer als lateral. 7. Bei bilateral adrenalektomierten Ratten nimmt in bestimmten, vorwiegend lateral gelegenen Nervenfasern die Zahl und Größe der Elementargranula in Abhängigkeit von der Überlebensdauer zu. Dies dürfte auf eine verstärkte Synthese und Speicherung von Corticotropin-Releasing Factor in diesen Nervenfasern zurückzuführen sein. Gegenüber dem Normalbefund ist die neurohämale Kontaktfläche erheblich vergrößert. Der perivaskuläre Raum enthält zerfallene Nervenfaserteile, die durch Bindegewebszellen phagocytiert werden. Diese Veränderungen dürften durch eine unter Versuchsbedingungen verstärkte Wachstumstendenz der Nervenfasern in Richtung auf die Blutgefäße und durch eine Abschnürung der Nerven-faserendigungen ausgelöst werden.
    Notes: Summary 1. In the subependymal and internal zones of the rat median eminence nerve fibres and vascular processes of ependymal and subependymal cells form neuro-glial bundles. They branch in the external zone. 2. In all these three zones of the infundibulum numerous neuro-glial synapses are found between nerve fibres and vascular processes of glial cells. The vascular processes contain a high number of microtubules as well as polymorphous granular inclusions. 3. In certain regions of the subependymal layer the intercellular spaces are enlarged. They form channel-like spaces containing small bundles of delicate nerve fibres. 4. Nerve cells of the infundibular nucleus located in the lateral parts of the infundibulum send dendrites to the medial parts of the infundibulum. In this area axo-dendritic synapses are found. 5. For morphometric analysis, the nerve fibres of the external zone were classified according to the diameter of their granules. It is shown that in the different regions of the external zone the distribution of the various types of nerve fibre is similar. Moreover it can be seen that a direct correlation exists between the size of the sectional plane of a given nerve fibre and the size of the granules it comprises. 6. Nerve fibre endings abutting on the basement membrane of the pericapillary space are mostly found in bulb-like protrusions of the external zone. The extent to which nerve fibres reach the perivascular space—as compared with the vascular processes of ependymal and glial cells—is higher in the medial than in the lateral parts of the infundibulum. 7. In bilaterally adrenalectomized rats the number and diameter of elementary granules increases in nerve fibres located laterally. This increase is directly related to the survival time and may be due to an enhanced synthesis and storage of Corticotropin-Releasing Factor in these nerve fibres. Compared with the findings in untreated animals the neurohemal contact area is significantly enlarged. The perivascular space contains degenerating nerve fibres which are undergoing phagocytosis by connective tissue cells. It is assumed that these alterations are due to the increased growth of nerve fibres towards the vessels of the “Mantelplexus”, and that, following adrenalectomy, this excessive growth leads to a pinching off of nerve fibres.
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  • 149
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    Cell & tissue research 136 (1973), S. 139-152 
    ISSN: 1432-0878
    Keywords: Giant fiber ; Earthworm ; Septum ; Electrical synapse ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die erneute elektronenmikroskopische Untersuchung der dorsalen Riesenfasern der Lumbriciden Lumbricus terrestris (L.t.) und Eisenia foetida (E.f.) zeigt, daß es sich bei den segmentalen Septen um Strukturen bisher unbekannter Komplexität handelt. Bei beiden Tierarten beträgt der Septalspalt nur 65 Å (E.f.) bzw. 75 Å (L.t.) und ist deshalb als „gap junction“ anzusprechen. Daneben fallen folgende Differenzierungen am Septum auf: „septate junctions” (L.t. und E.f.), „intermediate junctions“ (L.t. und E.f.), beidseitig am Septum gelegene und nicht von einer Membran umschlossene Membranappositionen (E.f.), sowie einseitig am Septum gelegene „dense projections“ (L.t.). Bei L.t. kommen außerdem auf beiden Seiten des Septums Vesikel vor, die von einer Elementarmembran umschlossen sind und nach Größe (φ ca. 575 Å), Lage, Haufenbildung und elektronenoptischem Habitus den Vesikeln chemisch übertragender Synapsen gleichen. Die Befunde werden hinsichtlich ihrer möglichen Bedeutung bei der elektrischen Übertragung und als Indizien für das Vorliegen einer gemischten Synapse diskutiert.
    Notes: Summary Electronmicroscopical examination of the dorsal giant fibers in the earthworms Lumbricus terrestris (L.t.) and Eisenia foetida (E.f.) reveals that their segmental septa are structures of so far unknown complexity. In both species the extracellular cleft between the two axon membranes of the septum amounts to only 65 Å (E.f.) and 75 Å (L.t.) respectively and is therefore regarded as “gap junction”. The following other structural differentiations of the septum were observed: “septate junctions” (E.f. and L.t.), “intermediate junetions” (E.f. and L.t.), densities apposed to both sides of the septum and not surrounded by a membrane (E.f.), and densities resembling “dense projections” on one side of the septum only (L.t.). In addition the septa of L.t. show vesicles on both sides which are bounded by a unit membrane and resemble the vesicles of chemically transmitting synapses in size (φ ca. 575 Å), location, accumulation, and electronoptical habitus. The significance of the findings in regard to electrotonic transmission and the possible existence of a mixed synapse is discussed.
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  • 150
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    Cell & tissue research 136 (1973), S. 177-182 
    ISSN: 1432-0878
    Keywords: Rat ; Epididymis ; Effect of vasectomy ; Spermatozoa ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Epididymal biopsies from rats that had undergone unilateral or bilateral vasectomies from one to eight months previously were compared with biopsies from their contralateral side or from normal controls to ascertain what ultrastructural changes had occurred. After vasectomy, spermatozoa appeared to dissolve in the lumen of the caput epididymidis and to be absorbed by the principal cells. About 5 weeks after vasectomy, numerous lamellar accumulations became apparent in the supernuclear region. Their resemblance to lysosomes or residual bodies was confirmed by an acid phosphatase reaction. After 10 weeks, similar lamellar and polymorphic accumulations on the contralateral side of animals with unilateral vasectomies indicated that resorption had also increased on the unligated side.
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  • 151
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    Cell & tissue research 136 (1973), S. 183-190 
    ISSN: 1432-0878
    Keywords: Nuclear pore ; Amphibian oocyte ; 8-fold symmetry ; Fibrous network ; Electron microscopy ; Negative staining
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Pictures, in front view, are presented of the nuclear pores from the oocytes of the newt Taricha granulosa. Negative staining is used. It is directly visible, on a substantial proportion of the pores, that the number of subunits in the annulus is 8. This conclusion had been reached earlier by other writers, who had used the rotation technique to ascertain the radial symmetry. The rotation technique is known to be very unreliable, though on this occasion had produced the correct result. A fibrous mesh network, connecting the subunits of separate pores is described.
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  • 152
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    Cell & tissue research 136 (1973), S. 191-205 
    ISSN: 1432-0878
    Keywords: Thymus ; Fine structure ; Avian ; Gallus domesticus ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of the normal thymus of the young chicken (Gallus domesticus) is described. Four main cell types, lymphoid cells, epithelial cells, macrophages and myoid cells, can be distinguished. The lymphocytes are more numerous in the cortex than in the medulla, and are quantitatively the most important component of the thymus. The epithelial cells vary greatly in morphology. Reticular epithelial cells, which have long cytoplasmic processes connected by desmosomes, and which appear to afford a supporting network for the free cells of the thymus, are present in the cortex and medulla. Undifferentiated epithelial cells are present in the medulla and cortico-medullary regions and have few intracytoplasmic fibrils or desmosomes. Cystic epithelial cells, showing intercellular and intracellular cyst formation are frequent in the medulla. Also present in the medulla are squamous epithelial cells which contain many intracytoplasmic fibrils and have numerous desmosomes, and which are involved in the formation of Hassall's corpuscles. Macrophages are present in moderate numbers in the cortex and medulla, and immature and fully developed myoid cells are common in the medulla. Other cell types present include granule-containing cells with desmosomes, large pale cells with few cytoplasmic organelles, mast cells, plasma cells, red blood corpuscles and cells of the granular leukocyte series.
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  • 153
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    Keywords: Ovary (mouse) ; Granulosa cells ; Steroidogenesis ; Electron microscopy ; Histochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A systematic study of Δ5-3β-hydroxysteroid dehydrogenase in the granulosa cells of immature and mature mice was made. The histochemical results were compared with the ultrastructural findings on the same cells in an attempt to determine whether the granulosa cells are capable of a steroidogenic role. In newborn and immature mice the granulosa cells of a great amount of follicles demonstrated a moderate or strong histochemical activity. In mature mice the granulosa cells demonstrated a weak or moderate activity normally only in preovulatory follicles and in some other atretic follicles. The granulosa cells of the normal developing follicles did not show such activity. In addition the histological control of numerous parallel sections demonstrated particularly in immature ovaries the presence of a great amount of atretic follicles. In the cytoplasm of the granulosa cells of the follicles in immature ovaries only clusters of lipid droplets with ribosomes were noted; while in the preovulatory follicles of mature animals there started to appear mitochondria with tubular cristae, smooth membranes of the endoplasmic reticulum and irregular lipid droplets. In the obviously atretic follicles several granulosa cells as well as theca interna cells showed numerous lipid droplets and ribosomes together with different degenerating organelles. The granulosa cells of the normal developing follicles showed a well developed Golgi complex, granular endoplasmic reticulum and free ribosomes. The histochemical and ultrastructural findings suggest a steroidogenic role of the granulosa cells only in the larger preovulatory follicles (probably related to an early luteinization of this layer) but this role was not demonstrated in the same cells in normal developing follicles. In addition, since an histochemical positivity was demonstrated also in the granulosa cells of some obviously atretic follicles, it is possible that many of the follicles having granulosa cells filled with lipid droplets and attached ribosomes and histochemically positive might be, in the immature ovaries, in a very precocious stage of atresia. It is to precise for these cells whether a cytoplasm with these two strictly correlated components (lipid droplets and attached ribosomes) and showing an histochemical positivity could carry-on all the biochemical steps involved in steroid biosynthesis or only has only a temporary capability to produce some precursors of steroids.
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  • 154
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    Cell & tissue research 138 (1973), S. 171-186 
    ISSN: 1432-0878
    Keywords: Tooth germs ; Organ culture ; Differentiation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Tooth germs from foetal rats of 17 days post-insemination were maintained in vitro for 12 days. Odontoblasts and ameloblasts differentiated and secreted their respective matrices in which mineralization occurred. The ultrastructure of the cells was qualitatively similar to that observed in normal development. Odontoblasts contained more lysosome-like bodies and were found to degenerate in some sites. Mantle dentine was formed but few von Korff fibres were observed. Calcospherites were rarely seen and the mineralizing front of dentine was predominantly linear, associated with numerous small early foci of mineral formation. Enamel showed prism formation associated with the Tomes' process of the ameloblast but some local disturbances in the pattern of enamel formation were observed.
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  • 155
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    Cell & tissue research 136 (1973), S. 277-289 
    ISSN: 1432-0878
    Keywords: Protonephridial system ; Turbanella cornuta Remane (Gastrotricha) ; Cyrtocytes ; Fine structure ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die Protonephridien des marinen Gastrotrichs Turbanella cornuta Remane werden elektronenmikroskopisch untersucht. Die Terminalapparate der Macrodasyoidea sind Cyrtocyten. Ein Reusenröhrchen besteht aus acht Längsstäben mit netzartigen Zwischenwänden aus dünnen Fibrillen. Im Lumen des Röhrchens schwingt eine Geißel. Die Wand eines Terminalbechers bildet ein zusätzliches Reusensystem, das mit Poren und Schlitzen versehen ist. Die drei bis vier Cyrtocyten eines Protonephridiums münden in eine Sammelzelle ein. Von dieser geht ein Exkretionsröhrchen mit Treibwimperflamme aus, welches von einer Ausleitungszelle gebildet wird. Die Cyrtocyten der beiden Gastrotrichenordnungen (Chaetonotoidea u. Macrodasyoidea) grenzen sich strukturell gegenüber bisher bekannten Formen dieses Zelltyps ab.
    Notes: Summary The protonephridial system of the marine gastrotrich Turbanella cornuta Remane was studied with the electron microscope. The terminal cells of the Macrodasyoidea are Cyrtocytes. Each tube for filtration consists of eight longitudinal rods with a net of fine fibrils between them; it contains a single whip. The wall of a terminal cup with its pores and slits is an additional system for filtration. Three or four filtration tubes are ending in a collecting cell. From this cell an excretory channel with one whip formed by an outlet cell arises. The filtration tubes of Macrodasyoidea are similar to those of Chaetonotoidea and differ from other forms of this cell-type.
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  • 156
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    Cell & tissue research 139 (1973), S. 333-350 
    ISSN: 1432-0878
    Keywords: Placenta ; Human ; Blood vessels ; Endothelium ; Vascular muscle, Myoendothelial junctions ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die Gefäße der Nabelschnur, Chorionplatte, Stammzotten und das Mikrozirkulationssystem des Zottenbaums der reifen menschlichen Plazenta wurden elektronenmikroskopisch untersucht. Die Endothel- und Muskelzellen besitzen auch am Ende der Gravidität alle morphologischen Kennzeichen voller Funktionsfähigkeit. Auffällig sind die zahlreichen myo-endothelialen Verzahnungen und die zahlreichen Kontakte der Muskelzellen untereinander. Sphinkterartige Einrichtungen werden nur an den Verzweigungen der Präkapillaren beobachtet. Gefäßnerven fehlen überall. Möglicherweise kann die Durchströmung der fetalen Placentagefäße durch autonome Kontraktion der Gefäßwände reguliert werden. — Alle Gefäße der Placenta sind elasticafrei. In den Nabelarterien sind elastische Systeme schwach ausgebildet. Eine Elastica interna wird nur in der Nabelvene gefunden. — Das Mikrozirkulationssystem in den Rami und Ramuli chorii sowie den Terminalzotten wird von allen bekannten Endstromeinheiten aufgebaut. Die englumigen Kapillarabschnitte befinden sich vor allem in unmittelbarer Nachbarschaft zum organellenreichen Syncytiophoblast, während die weitlumigen Abschnitte, die möglicherweise die venösen Kapillarstrecken sind, den Epithelplatten anliegen.
    Notes: Summary In the human placenta at term the blood vessels of the umbilical cord, chorionic plate and trunks and the microcirculation system of the placental lobes have been investigated. Also at the end of pregnancy the vascular endothelium and the smooth muscle cells exhibit all morphological criteria of full functional activity. The vessel wall is characterized by numerous myoendothelial junctions and many adjacent muscle cells being in close contact with one another. Sphincterlike structures can only be observed at the ramifications of the precapillaries. Vascular nerves are always absent. The blood circulation is perhaps regulated autonomously by means of the contractile vessel wall.—In all placental vessels a special tunica elastica never exists. In the umbilical arteries elastic systems are poorly developed. A genuine internal elastic layer only occurs in the corresponding vein.—In the region of the rami and ramuli chorii as well as in the single villi the microcirculation system consists of all types of terminal vessels. The capillaries with small diameter are preferentially situated close to the organellrich syncytiotrophoblast, whereas the distended segments, which may represent the venous capillaries, are in intimate contact with the epithelial plates.
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    Cell & tissue research 139 (1973), S. 369-396 
    ISSN: 1432-0878
    Keywords: Synapses ; Giant fibres ; Ventral nerve cord ; Lumbricus terrestris L. ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die proximalen Kollateralen der dorsalen Riesenfasern des Regenwurms wurden in Serienschnitten vom Soma bis zum Eintritt in die Riesenfaser verfolgt und im Hinblick auf ihre Feinstruktur und ihre synaptischen Kontakte Untersucht. Es finden sich sowohl chemische als auch elektrische Synapsen. Ihre Feinstruktur wird mit der bekannter Synapsen anderer Wirbellosen und Wirbeltiere verglichen. In beiden Riesenfasersystemen kommen efferente chemische Synapsen mit feinen postsynaptischen Verzweigungen vor, die anscheinend von Bauchmark-Motoneuronen stammen. Das Axon der medianen Riesenfaser weist darüber hinaus nur noch eine elektrische Synapse mit den Rieseninterneuronen auf. Demgegenüber erhalten die Kollateralen der lateralen Riesenfasern zahlreiche Afferenzen, die zum Teil als sensorische Fasern der Epidermis, multisegmentale Fasern der Hauptfaserzüge und Rieseninterneurone identifiziert werden konnten. Weitere Afferenzen stammen vermutlich von unisegmentalen Interneuronen her. Beide lateralen Riesenzellaxone bilden außerdem miteinander eine elektrische Chiasma-Synapse mit besonderen Membraneinfaltungen.
    Notes: Summary The proximal collaterals of the dorsal giant fibres of the earthworm were traced through serial sections from the cell bodies to the giant axons. Their structure and synaptic connections were examined. There are chemical as well as electrical synapses. Their fine structure is compared to that of other known invertebrate and vertebrate synapses. Both giant fibre systems have efferent chemical connections with thin postsynaptic arborizations which probably belong to ventral cord motoneurons. Moreover the median giant axon is connected by an electrical synapse with the giant interneurons. The lateral giant collaterals on the contrary receive many afferences through chemical synapses which were partly identified as sensory fibers from the epidermis, multisegmental axons from the main fibre bundles or giant interneurones. Other afferences probably come from unisegmental interneurones. In addition both lateral giant axons form an electrical chiasma synapse with special membrane folds.
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    Cell & tissue research 139 (1973), S. 397-403 
    ISSN: 1432-0878
    Keywords: Visual system ; Musca domestica ; Monopolar cells ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Nur drei von den fünf Monopolarzelltypen L1, L2, L3, die in jeder Cartridge der Lamina vorhanden sind, sind synaptisch mit den sechs Rezeptorendigungen (R1–R6) verbunden. Entsprechend der Verteilung ihrer Dendriten sind zwei von den drei Neuronen (L1 und L2) zur gesamten Länge der Endigungen verbunden, während das dritte Neuron (L3) Verbindungen nur in dem äußeren Zweidrittel der Lamina hat. Obwohl diese drei Zellen als Neurone 2. Ordnung des Neurosuperpositionsauges wirken könnten, deutet ihre anatomische Organisation auf funktionelle Unterschiede hin.
    Notes: Summary Only three of the five types of monopolar cells which are present in each cartridge of the lamina have synaptic connections with receptor endings (R1–R6). Due to the distribution of their dendrites two of these (L1 and L2) contact the whole length of the six receptor endings of their cartridge whereas the third type (L3) contacts only their outer 2/3rds. Although these three cells may function as the second order neurons of the neurosuperposition eye, their anatomical relationship imply functional differences between them.
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  • 159
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    Cell & tissue research 139 (1973), S. 431-450 
    ISSN: 1432-0878
    Keywords: Cardiac muscle ; Frog ; Regeneration ; Electron microscopy ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary From the 5th day up to the end of 3rd week following local crushing of the frog ventricle myocardium, ca. 13% of myocyte nuclei, in the vicinity of the damaged zone, were labelled after a single 3H-thymidine (3HTdr) injection, and 30–50% of these were labelled after repeated 3HTdr administration. The number of myocyte mitoses was maximal (ca. 1.3%) at the beginning of the 3rd week. The reactive proliferation of myocytes was accompanied by their “partial dedifferentiation”. This involved the nuclear euchromatic rearrangement, increase in size of nuclei and nucleoli, accumulation of the sarcoplasm rich in free ribosomes and rough endoplasmic reticulum, hyperplasia of the Golgi apparatus, and the appearance of 80–100 Å in diameter cytofilaments. Electron microscope autoradiography has shown that all these changes may be more or less pronounced in myocytes incorporating 3HTdr. The myofibril ultrastructure was found to be unchanged during S phase. However, in the mitotically dividing myocytes, the majority of Z-disks were disintegrated resulting in progressive release of myofilament bundles. Both 3HTdr labelled and mitotic myocytes were anchored to the adjacent ones by desmosomes and intercalated disks. No free myoblasts were observed.
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  • 160
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    Cell & tissue research 139 (1973), S. 463-471 
    ISSN: 1432-0878
    Keywords: Gallbladder (Human) ; Mucus secretion ; Reverse pinocytosis ; Histochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Mucous secretory activity of the human gallbladder epithelium was investigated by light and electron microscopy and with histochemical techniques. There are two types of granules in the supranuclear region of the epithelial cells. The one low in density contains a fine filamentous material and gives a strongly positive silver methenamine reaction. The other is dense and only faintly positive. The granules of the former are considered to be mucous secretory granules and the granules of the latter may be lysosomes. PAS positive granules correspond presumably to both types of granules mentioned above. The mucous secretory granules are considered to be synthesized by the Golgi apparatus and the granular endoplasmic reticulum as has been confirmed in other mucous secretory cells. Their content is released from the cell by reverse pinocytosis. Typical goblet cells occur frequently in the fetal epithelium, but cannot be observed in the adult specimens.
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  • 161
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    Cell & tissue research 137 (1973), S. 159-166 
    ISSN: 1432-0878
    Keywords: Ovum ; Mouse ; Membranes ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ultrastructural studies have revealed the presence of unusual membrane complexes within developing mouse oocytes. These structures, most obvious 18 days post fertilization, are found in the nucleus or cytoplasm of cells in meiotic prophase. The complexes, usually found in small groups, are characterized by a slightly bowed appearance, and a thin middle section that is vesiculated at each end. At high magnification the middle section exhibits a pentalaminar structure similar to tight junctional complexes, while the looped membranes of the vesiculated ends are trilaminar in appearance. In addition to being free in the nucleoplasm or cytoplasm, the complexes are also seen in continuity with the inner and outer leaflets of the nuclear envelope, and with typical membranes forming cytoplasmic tubular systems. The possible formation of these complexes from blebs or vesicles derived from the nuclear envelope is presented and the role that these structures may play in developing oocytes is discussed.
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  • 162
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    Cell & tissue research 137 (1973), S. 195-208 
    ISSN: 1432-0878
    Keywords: Thyroid (Salamander) ; Influence of TSH ; Epithelial cells ; Crystalloid structures ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effect of thyrotropic hormone (TSH) on the salamander thyroid gland was studied by electron microscopy. The following sequence of changes in the follicular cells was observed: (1) 1–1.5 hrs after a single administration of 1 i.u. of TSH, many large colloid droplets appear in the apical cytoplasm; (2) within about 2 hrs hereafter, most of them are replaced by large vacuolar bodies, and cytosomes are remarkably decreased; (3) 2.5–3 hrs after two administrations of 1 i.u. of TSH at an interval of 20 hrs, large vacuolar bodies with or without filaments are frequently observed but cytosomes are hardly encountered; (4) in the group placed at room temperature for 10 days after a single administration of TSH, large vacuolar bodies almost disappear; (5) in the group placed in the ice room for 10 days after the same treatment, large vacuolar bodies with or without filaments frequently appear but cytosomes almost disappear; and (6) in some of large vacuolar bodies with filaments the different stages of crystalloid formation are discernible. From these findings, it is suggested that large colloid droplets are changed into large vacuolar bodies and that crystalloid originates from large vacuolar bodies with filaments, probably as a result of interrupted hydrolysis caused by a deficiency of cytosomes.
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  • 163
    ISSN: 1432-0878
    Keywords: Pituitary gland ; Male ; Triturus cristatus carnifex Laur. ; “Globular basophil cells” ; Antiandrogen treatment ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The adenohypophysis of the newt Triturus cristatus carnifex Laur. shows three types of cells: 1) cells with granules of about 350–550 mμ in diameter, 2) cells with small granules of 200–250 mμ in diameter and globules with a cristal-like arrangement containing cylinders with a diameter of about 960 Å and 3) cells containing small granules only. The AA. discuss the ultrastructural changes of the gland and the modifications of sexual secondary characters (S.S.C.) in animals given Cyproterone acetate (1/2 mg every three days). The animals have been treated for a period of time varying between 3 and 5 months, starting in October-November, when S.S.C. begin to develop again. At the end of the treatment the newths showed a loss of S.S.C., and the ultrastructure of the adenohypophysis resembled that of castrated animals, i.e.: great swelling of R.E.R. and partial degranulation of glycoprotein secreting cells which contain the 200 mμ granules and the globules. The S.E.R. showed also swelling and hyperactivity.
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  • 164
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    Keywords: Optic nerve ; Myelination ; Hypocholesteremic drug ; Exogenous and endogenous cholesterol ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effect of AY-9944, an inhibitory cholesterol biosynthesis, on the myelination of the optic nerve of rats was studied. Suckling rats were injected intraperitoneally with the drug every other day from birth, and were sacrificed at 10, 20 and 30 days of age together with littermate controls. The analysis is based on counting, at the electron-microscope level, the number of unmyelinated axons and the number of myelin lamellae surrounding each myelinating axon. The results indicate that a decrease in endogenous cholesterol by AY 9944, induced an overall retardation of the myelination process in the optic nerve: a larger proportion of myelinated axons and smaller number of myelin lamellae around the myelinating axons, when compared with the littermate controls, was observed. Exogenous cholesterol from the maternal milk did not compensate for a lack in endogenous cholesterol. Degenerating myelin sheaths were frequently seen in the experimental optic nerves at 20 and 30 days of age. Numerous membranous, intracytoplasmic drug-induced inclusions were found at all ages studied.
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  • 165
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    Cell & tissue research 140 (1973), S. 101-124 
    ISSN: 1432-0878
    Keywords: Kidney ; Contractile structures ; Embryonic metanephros ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Cytoplasmic filaments have been observed in the cells of normal and pathological kidneys. These filaments are usually grouped into bundles anchored to electron dense bodies underlying the cell membrane. In the embryonic human metanephros the filaments are found within the cells of different portions of the nephron at various stages of development. They appear first in the podocytes, almost simultaneously in the Bowman's capsule and tubular cells, then in the “mesangial cells”, and finally in the cells of the media of the afferent glomerular and interlobular arterioles. The presence of filaments and their attachment bodies in the mammalian nephron suggests that the podocytes and the so-called mesangial cells have a contractile activity, thus representing an intraglomerular apparatus which regulates the intravascular pressure, blood flow and filtration rate in the glomerular capillaries, whilst the contractile activity of the Bowman's capsule and proximal, distal, and collecting tubules, could facilitate the progression of the filtrate. The increase in number of the filaments in some pathological conditions is probably related to the functional changes of the intraluminal pressure in the glomerular capillaries, in the Bowman's space, and in the tubular lumen.
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  • 166
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    Cell & tissue research 140 (1973), S. 39-75 
    ISSN: 1432-0878
    Keywords: Johnston's organ ; Camponotus vagus (Hymenoptera, Formicidae) ; Chordotonal structure, Scolopidia ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé L'organe de Johnston de Camponotus vagus est composé par un ensemble d'environ 55 structures chordotonales, chacune étant formée par une ou plusieurs scolopidies. Les terminaisons dendritiques de tous les organes chordotonaux aboutissent sous des cônes cuticulaires insérés dans la membrane d'articulation entre le pédicelle et le troisième article antennaire. Chaque scolopidie est composée de 3 dendrites; les trois segments proximaux sont entourés par une même cellule enveloppe CE1 fortement accolée aux cellules épithéliales adjacentes au moyen d'attaches spécifiques. Au niveau des racines ciliaires et des segments ciliaires les trois dendrites sont enveloppés dans une cellule scolopale qui sécrète des colonnes scolopales autour de chaque dendrite et ayant des points de jonctions avec ceux-ci. Ces colonnes scolopales se réunissent ensuite pour entourer les trois dendrites dans un cylindre scolopal unique. A partir des dilatations ciliaires les dendrites évoluent de façon différente; certains s'interrompent très tôt dans le cylindre scolopal alors que d'autres s'élèvent plus haut jusqu'à l'articulation, leur extrémité distale étant coiffée d'un tube cuticulaire. Par structure chordotonale il n'y a généralement qu'un dendrite — quel que soit le nombre des scolopidies à l'origine de la structure — qui est relié à la membrane articulaire par une «tigelle cuticulaire intermédiaire». Chaque structure chordotonale est formée par une scolopidie, ou le regroupement de plusieurs identiques à celle décrite ci-dessus. Le plus souvent les premières cellules enveloppes CE1 présentent des zones d'affrontement membranaires entre CE1 des scolopidies d'un même organe chrodotonal. A partir du niveau des cellules scolopales, deux cellules enveloppes CE2 et CE3, se relayent successivement, formant un manchon autour des groupements scolopidiaux, déterminant ainsi l'unité sensorielle. On a observé et décrit des différenciations intercellulaires à tous les niveaux du système, entre éléments nerveux d'une part et éléments nerveux et structures associées d'autre part. Des inclusions particulières telles des microtubules associées en chaîne au moyen de bras ont notamment été décrites au niveau de structures de jonctions. Le rôle des divers structures et caractères spécifiques rencontrés lors de la description de l'ensemble de la structure réceptrice est envisagé dans le sens des mécanismes de transduction.
    Notes: Summary Johnston's organ of Camponotus vagus is composed of 55 chordotonal structures, each of them being formed by one or several scolopidia. The dendritic endings of the chordotonal organs are in contact with cuticular cones which occur at the articular joint between pedicellus and the third antennal segment. Each scolopidium is composed of three dendrites. The three proximal segments are enclosed by one cell, CE1, which is connected with neighbouring epithelial cells by specific attachment zones containing microtubules. At the level of the ciliary roots and of the dendritic ciliary segments, the three dendrites are enclosed by the scolopal cell which secretes the scolopal rod around each dendrite. Some junctions occur between the dendrites and the scolopal cell. The scolopal rods are interconnected constituting the scolopal ring. The distal portion of each dendrite exhibits a different ultrastructure: some of them are short and terminate in the scolopal ring while others continue to the joint, here being covered by a cuticular canal. Generally there is only one dendrite which is connected with the joint by a cuticular stalk. Each chordotonal structure is formed by one or several scolopidia. Very often the first ensheathing cells, CE1, of one organ are connected by some intercellular differentiations. Above the scolopal cells two other ensheathing cells, CE2 and CE3 are to be found. These cells define each sensory unit. Intercellular differentiations are described at all levels of the system, between neural elements on the one hand and between neural elements and associated structures on the other hand. Specific inclusions such as associated “arm-bearing” microtubules are described near some of the junctions. The possible role of these specific structures in the process of impulse conduction in mechanoreceptors is discussed. The results are compared with those obtained from Johnston's organs of other species. Their functional significance is discussed.
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  • 167
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    Cell & tissue research 140 (1973), S. 125-144 
    ISSN: 1432-0878
    Keywords: Spermatogenesis ; Meiosis ; Drosophila melanogaster ; Synaptinemal complex ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Meiosis in male Drosophila melanogaster was studied with the electron microscope. The number and the distribution of ring channels between individual members of a cluster of primary spermatocytes was determined from serial sections. The tubules with a diameter of 45 nm characteristic for meiotic prophase nuclei gave a chromatin type reaction, when treated with EDTA according to Bernhard's technique, thus suggesting that these tubules contain DNA. A material resembling central regions of synaptinemal complexes was observed in the nucleolus of primary spermatocytes during the downward movement in the testis. It is suggested that they represent unused precursors to central components of synaptinemal complexes, which are absent at pachytene of Drosophila males. Up to six tail fibers (kinetosomes + axonemes) were observed in every primary spermatocyte prior to meiosis.
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  • 168
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    Cell & tissue research 140 (1973), S. 203-216 
    ISSN: 1432-0878
    Keywords: Synapses ; Development ; Chick embryo ; Cell culture ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The formation and development of synaptic contacts between dissociated chick spinal cord neurons has been investigated. By the 6th day in vitro “immature” profiles with few vesicles were observed. By 14–18 days “mature” types with numerous vesicles were found, indistinguishable from those of newly hatched chick spinal cord. After this period degeneration occurred, and was especially marked in the post-synaptic element. Such degeneration could be postponed by the addition of small numbers of somatic muscle cells. The Kanaseki and Kadota (1969) technique was applied to the study of coated vesicles at various stages of synaptic development.
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  • 169
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    Cell & tissue research 140 (1973), S. 187-202 
    ISSN: 1432-0878
    Keywords: Macrophage ; Differentiation ; Triolein ; Stereology ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The results of an objective two- and three-dimensional analysis of the morphological features of normal and triolein-induced mouse peritoneal macrophages are reported. An “equivalent circle“ technique for resolving the effects of volume and surface area on volume-to-surface parameters is described. The method is a simple comparative one which does not require the actual determination of cell volume. Macrophage stimulation promoted increases in mean cell size, cytoplasmic granularity and volume-to-surface ratio. In addition, a reduction in nuclear volume-to-surface ratio accompanied in vivo stimulation. Nucleocytoplasmic ratio remained constant. The equivalent circle procedure showed that the increase in cellular volume-to-surface ratio was due largely to the increase in cell volume; the decrease in nuclear volume-to-surface ratio was primarily the result of a substantial increase in nuclear membrane surface area. Stereological estimations suggest that interiorized cell membrane (in the form of triolein-containing phagosomes) is replaced by newly reconstructed surface membrane.
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  • 170
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    Cell & tissue research 140 (1973), S. 235-259 
    ISSN: 1432-0878
    Keywords: Ciliated protozoa ; Loxophyllum and Prorodon ; Trichocysts ; Toxicysts ; Expulsion mechanism ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die Nesselkapseltrichocysten der Ciliaten Loxophyllum und Prorodon wurden hinsichtlich ihrer Feinstruktur sowie des Ausschleuderungsablaufes untersucht. Loxophyllum besitzt zwei morphologisch unterscheidbare Sorten von Toxicysten, wohingegen Prorodon nur eine Art dieser Organelle aufweist (Krüger, 1936). Wie an Hand gehemmter Stadien gezeigt werden kann, verläuft die Ausschleuderung bis auf geringfügige Variationen bei den drei Sorten in der gleichen Art: Schläuche, die im ruhenden Zustand bereits in den endgültigen Dimensionen in der Toxicystenkapsel eng ineinandergeschachtelt vorliegen, werden handschuhfingerförmig umgestülpt und verlassen hierdurch die Kapsel und damit den Zellkörper. Dieser Prozeß ist mit der Ausscheidung einer teils fädigen, teils amorphen Substanz gekoppelt. Der Umstülpungsvorgang der Innenstruktur der Nesselkapseltrichocysten wird mit den völlig andersartigen, während der Ausschleuderung von Mucocysten und Spindeltrichocysten ablaufenden morphologischen Veränderungen verglichen. Es zeigte sich, daß aufgrund ihrer differierenden Feinstrukturen und Funktionsweisen in den Nesselkapseltrichocysten einerseits und in den Mucocysten sowie Spindeltrichocysten andererseits zwei grundsätzlich voneinander verschiedene Organellentypen gesehen werden müssen.
    Notes: Summary The toxicysts of the ciliates Loxophyllum meleagris and Prorodon teres were examined with regard to fine structure and expulsion mechanism. Loxophyllum possesses two morphologically distinct types of toxicysts, whereas in Prorodon only one type is present. As can be shown by discharge inhibition experiments, the expulsion mechanisms, except for small variations, are identical in all three types: Tubes, which in their resting state lie closely packed one within the other possess already at this state their final dimensions; they are inverted, thereby leaving the capsule and thus the cell body. This process is correlated with the excretion of a substance partly filamentous, partly amorphous. The inversion of the tubes during the expulsion is compared to the fundamentally different morphological alterations during discharge of mucocysts and spindle trichocysts. The differences and similarities in fine structure and function between toxicysts on the one hand and mucocysts and spindle trichocysts on the other, indicate that two rather than three fundamentally different organelle types must be distinguished.
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  • 171
    ISSN: 1432-0878
    Keywords: Superior colliculus ; Primate, Galago ; Optic terminals ; Eye enucleation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Several types of terminals were found in the three superficial collicular layers of Galago. At least two axon terminals with round vesicles (R1 and R2) could be distinguished on the basis of vesicle packing and electron density of the cytoplasmic and mitochondrial matrices. R1 axon terminals were characterized by aggregations of vesicles in an electron lucent cytoplasm and mitochondria with a relatively dark matrix, while in R2 axon terminals the vesicles were more evenly distributed in an electron dense cytoplasm and the mitochondrial matrix was pale. R2 endings occurred in clusters in the stratum griseum superficiale; they were absent in the stratum zonale. R1 endings were found in all three superficial collicular layers. Both types of R terminals made asymmetrical contacts with small dendrites, dendritic spines and F profiles. Profiles containing flattened vesicles and establishing symmetrical contacts were numerous, and many could be identified as dendrites by accepting as criteria for dendrites evenly spaced microtubules, clusters of ribosomes and the fact that these F profiles were postsynaptic to other terminals. F terminals were presynaptic to other F profiles, dendrites and somata; they were postsynaptic to R terminals and took part in serial synapses. Dendrodendritic contacts were frequent, somatodendritic contacts rare. After eye enucleation most R2 axon terminals underwent the electron dense degenerative reaction. The degeneration process was a lengthy one; many degenerating boutons were found 30 days after axotomy and some persisted up to 180 days postoperatively. There was strong indication that the superior colliculus received more crossed than uncrossed retinofugal fibers. The crossed and uncrossed retinocollicular axons terminated in two different substrata of the stratum griseum superficiale.
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  • 172
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    Cell & tissue research 140 (1973), S. 357-368 
    ISSN: 1432-0878
    Keywords: Muscle spindle ; Guinea-pig ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Nuclear bag and nuclear chain intrafusal fibres are present in guinea-pig muscle spindles. Unlike muscle spindles in other species two types of nuclear chain fibre seem to be present. The electron microscopical appearance of one type of nuclear chain fibre is similar to that of nuclear bag fibres. It is suggested that under tension the nuclei of small nuclear bag fibres become sufficiently displaced to form nuclear chain-like fibres. The frequent occurrence of fibres which combine some of the properties of both nuclear bag and nuclear chain fibres indicates the possible occurrence of a third type of intrafusal fibre. The sensory innervation of guinea-pig muscle spindles is similar to that of the cat and the rat. Three types of motor nerve ending which could be classified according to the complexity of their subneural apparatus were seen.
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  • 173
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    Cell & tissue research 140 (1973), S. 369-388 
    ISSN: 1432-0878
    Keywords: Nucleus preopticus ; Nucleus lateralis tuberis ; Leuciscus rutilus ; Falck-Hillarp technique ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The hypothalamus of the teleost fish Leuciscus rutilus was investigated with the Falck-Hillarp technique. The nucleus preopticus (NPO) and the nucleus lateralis tuberis (NLT) contain no fluorescent, i.e. catecholaminergic cells. Green fluorescent fibers probably originating from the paraventricular organ and/or the preoptic recess organ, are intermingled with the cells. The electron microscopical study was based on the three fixatives glutaraldehyde-osmium tetroxide, osmium tetroxide and potassium permanganate. In the NPO two cell types are recognized, characterized mainly by dense core vesicles (dcv) with measured diameter of 130 nm and 170 nm across respectively. The endoplasmic reticulum in the former cell type generally has large dark inclusions measuring from 175 to 375 nm across, which are also found in the neurite. In the NLT, four different cell types are identified, some of which are subject to considerable variations. The rostral and the medial parts of the nucleus include a large cell type (I) with dcv of diameter 170 nm. The medial part also has a small cell type (II) with dcv of 80 nm. The lateral part is characterized by two cell types (III, IV). Cell type III occurs in three forms with dcv of about 140 nm. The fourth cell type (IV) is rare and contains irregularly formed granules, the most circular ones measuring about 130 nm and the most elongated ones 110 nm×210 nm. The ventrolateral part contains the same cell types (except for type II) as those found in the lateral and medial parts. The morphological differentiation of the NLT as well as its different cell types strongly indicates its functional diversity. After permanganate fixation the secretory granules of the different cell types in the NPO and the NLT appear as “empty” vesicles. This method also reveals that the cell types of the two nuclei have dcv of about 90 nm. The possible monoaminergic content and the role of these dcv are discussed.
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  • 174
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    Cell & tissue research 140 (1973), S. 425-432 
    ISSN: 1432-0878
    Keywords: Muscle innervation ; Myxine glutinosa (L.) ; Dense-core vesicles ; Monoamine fluorescence ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Motor nerve terminals on “white” and “intermediate” muscle fibers of the Atlantic hagfish (Myxine glutinosa, L.) contain translucent synpatic vesicles and about 1–2% dense-core vesicles. Terminals on “red” muscle fibers contain up to 40% dense-core vesicles with diameter 800–1100 Å. Examinations for formaldehyde-induced fluorescence indicate yellow fluorescence (5-HT ?) apparently corresponding with terminal axons on “red” muscle fibers in craniovelar muscles. Possibly “red” muscle fibers of Myxine receive monoaminergic innervation.
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  • 175
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    Cell & tissue research 140 (1973), S. 481-496 
    ISSN: 1432-0878
    Keywords: Synaptosomes ; Dense projections ; Complex vesicles ; Serial sections ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Synaptosomes and synaptic junctions have been examined employing serial sections, with emphasis placed on four areas of investigation. 1. Starting from unequivocal synaptosomal profiles and tracing them through consecutive sections to the periphery of the synaptosomes, it is clear that vesicles are the one constant feature of the presynaptic terminal. In no instance was it possible to identify an empty membranous profile as synaptosomal. 2. Following a similar procedure it was found that the criteria required to predict the existence of a junctional region within a synaptosomal profile are: the accumulation of synaptic vesicles at one locus within its presynaptic component, and the presence of a postsynaptic profile characterized by two or more junctional features. 3. Serial sections of non-osmicated, PTA stained synaptic junctions confirm the regularity and orderliness of dense projection distribution along the length of the junction. 4. Complex vesicles can usually be followed in two and sometimes three adjacent sections, appearing either as intact vesicles or empty shells. Further observations confirmed that the latter profiles may be sections through the periphery of intact vesicles or through isolated shell fragments. They are more common in the latter form in unbuffered material.
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  • 176
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    Cell & tissue research 141 (1973), S. 529-544 
    ISSN: 1432-0878
    Keywords: Osteoclast ; Parathyroid hormone ; Lysosomes ; Bone resorption ; Electron microscopy ; Histochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Young rats were treated with high doses of parathyroid hormone (PTH). Osteoclasts from these animals revealed characteristic alterations in comparison to control cells: a) The cytoplasm contained large vacuoles with phagocytosed cells, some of which resembled osteoblasts or osteocytes. The vacuoles were interpreted as lysosomes because the engulfed cells often appeared partly digested and the vacuoles contained acid phosphatase as demonstrated histochemically, b) lipid droplets were present in the cytoplasm and usually located close to the endoplasmic reticulum and/or in regions with many free ribosomes, c) the Golgi complex was more frequently separated from the nuclei than in control cells, d) small coated cytoplasmic bodies were numerous in the peripheral cytoplasm, e) the membranes of the endoplasmic reticulum were fused in some places, f) cytoplasmic regions with numerous free ribosomes were frequent, g) large ring-shaped granules occurred in some mitochondria. Energy dispersive X-ray analysis of these granules provided evidence that they contained calcium and probably phosphorus, h) in some osteoclasts the mitochondria were enlarged. — The findings are consistent with an increased activity of osteoclasts and in particular a stimulation of the lysosomal system in these cells.
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  • 177
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    Keywords: Wound healing ; Lymnaea stagnalis ; Amoebocytes ; Phagocytosis ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The process of wound healing in Lymnaea stagnalis was studied by light and electron microscopy. Snails were wounded by making incisions in the skin. The observations showed that the wounds are closed by muscular contraction and by formation of thrombi of blood amoebocytes. These thrombi form a large amoebocyte plug. During the first 72 hrs after incision thin tubules (diameter 175–225 Å) were observed between the amoebocytes in the plug. Possibly these tubules represent a blood clotting protein. The round amoebocytes constituting the plug can be regarded as normal blood amoebocytes. First, ultrastructurally they closely resemble the amoebocytes of the circulating blood. Second, not only blood amoebocytes but also plug amoebocytes of snails injected with India ink before incision contained ink particles, indicating that the cells are of one type. Apparently due to phagocytosis of cell debris the number of lysosomes in plug amoebocytes increased during the first days after incision. Eighteen to twenty four hrs after incision the first signs of differentiation of round plug amoebocytes into flattened cells were observed. Between these cells collagen was seen from 3–5 days after incision and onwards. It is suggested that these flattened amoebocytes produce collagen fibrils. These cells are structurally different from collagen producing fibroblasts and from muscle cells of the surrounding connective tissue. Transformations of amoebocytes into these two latter cell types were not found. Ninety days after incision the connective tissue in the wound area is still different from that on non-injured sites.
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  • 178
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    Keywords: Paracrystals ; Reinke crystals ; Leydig cells ; Normal human testis ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary One of two types of paracrystalline inclusions, other than Reinke crystals, was encountered in the Leydig cells of the normal mature testes of 9 out of 10 patients. The basic ultrastructure of these formations was that of parallel arrays of fine filaments (8 cases) or tubules (1 case). The filamentous structures, designated as type A paracrystals, consisted of fascicles of parallel rows of 4 or 5 dense fibrils. The latter typically contained dense granules or banded striations spaced at regular intervals. In 4 cases the inclusions were found in the cytoplasm while in 4 others they were confined to the nuclei. The tubular type of paracrystal, type B, was observed in only one patient. Here, groups of closely packed tubular inclusions occupied large portions of cytoplasm. The tubular walls were composed of closely applied, small, circular profiles. In no instance were paracrystals and Reinke crystals encountered in the same cell. A possible role of the former as precursors of the latter is discussed but there is no strong supporting evidence for this despite certain suggestive similarities in unit and subunit measurements.
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  • 179
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    Keywords: Median eminence (Rabbit) ; Dense-core vesicles depletion ; Releasing factors ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects of mating on the depletion of osmiophilic material from dense-core vesicles (DCV) within the external layer of the rabbit median eminence (ME) were investigated. Two different populations of DCV were demonstrated within the ME external layer of the non-mated control animals. A plot of the diameters of these vesicles showed two peaks, one at 90–100 nm, and the other at 120–130 nm. These two populations of DCV were found in separate axons and axon terminals in contact with, or near the perivascular spaces of, portal capillaries. Within these axons and terminals an occasional membrane profile or “vesicle ghost” was also observed. The same two populations of DCV were evident in the ME external layer of animals that were sacrificed at 10 minutes post-coitus. In these experimental animals, the number and size of the smaller population of DCV were the same as those of the none-mated controls. However, there was an obvious decrease in the number of the large (120–130nm) DCV, together with a simultaneous marked increase in the number of “vesicle ghosts”. These ghosts had a mean diameter of 137±14 nm. On the basis of their size, it is suggested that the “vesicle ghosts” represent large DCV that have been depleted of their content following mating. Ultrastructural evidence for the depletion of osmiophilic material from the large DCV of mated animals is provided. According to previous writers the smaller DCV within the ME are aminergic, whereas the larger DCV may contain releasing factors (RF). Our findings provide further morphological evidence to support this hypothesis. Furthermore, RF and biogenic amines appear to be contained within separate nerve terminals in the rabbit ME.
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  • 180
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    Cell & tissue research 142 (1973), S. 63-68 
    ISSN: 1432-0878
    Keywords: Snail ; Regeneration of eye ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distal half of the posterior tentacle of adult Helix aspersa and Cryptomphallus aspersa was removed and the proximal half was studied with light and electron microscopy after different intervals. The tentacle itself does not regenerate, but the receptor organs at the distal end of the normal tentacle differentiate at the level of the section. The newly formed eye is smaller than the control; however, its components and subcellular characteristics resemble those of the normal eye.
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  • 181
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    Keywords: Neuromuscular junction ; Development ; Cholinesterases ; Axonal transport, Neurotubules, Colchicine, Vinblastine ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Colchicine (0.1 M) or vinblastine (0.01 M) was locally applied on the sciatic nerves of newborn rats. Both colchicine and vinblastine caused reversible disappearance of axonal neurotubules and appearance of increased amounts of neurofilaments at the site of application. Subsequent morphogenesis of myoneural junctions in the tibialis anterior muscle was studied after histochemical demonstration of acetylcholinesterase (AChE; E.C. 3.1.1.7) and non-specific cholinesterase (Ns. ChE; E.C. 3.1.1.8) activity in the myoneural area. Development of the postsynaptic muscle plasma membrane of the myoneural junction was arrested in the ipsilateral, but not in the contralateral control side, for a period of about three weeks following treatment with the test substances. After this delay the myoneural morphogenesis continued normally and neurotubules were seen in the axoplasm. Since disruption of neurotubules is likely to cause blockage of the intratubular axoplasmic transport system, it seems possible that the neurotrophic influence responsible for the development of the postsynaptic muscle membrane is mediated through a secretory product transported along axons intratubularly to the nerve endings.
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    Cell & tissue research 142 (1973), S. 223-239 
    ISSN: 1432-0878
    Keywords: Subcommissural organ (SCO) ; Basal secretion, Lateral secretion ; Extracellular spaces (ECS) ; Innervation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Morphological evidence is presented supporting the possibility of basal secretion into hypendymal capillaries of the adult rabbit subcommissural organ (SCO). The synthetic apparatus of the SCO cell is described as well as the heterogeneous granules and vesicles which are concentrated in the basal processes bordering a widened perivascular space. The origin of the electron dense granules, of which two fairly distinct subgroups are found, is discussed. A binding of secretory sacs to the lateral plasma membrane is seen. The possibility of a lateral secretion is supported by the presence of a system of extracellular channels between SCO cells which are filled with a flocculent material resembling that of the secretory sacs. Nerve perikarya which are separated from the SCO by only a few glial fibers are demonstrated. Synapses are described in nerve fascicles bordering on the hypendymal capillaries. The possibility of an innervation of the hypendymal region is discussed as well as possible nervous connections with the pineal gland.
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  • 183
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    Cell & tissue research 142 (1973), S. 443-464 
    ISSN: 1432-0878
    Keywords: Neurosecretion ; Posterior Pituitary gland ; Colchicine ; Axoplasmic flow ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effect of colchicine on the release of neurosecretory material from the posterior pituitary gland was investigated in the rat in vivo and in vitro. Colchicine was administered subarachnoidally when neurophysin, radiolabelled by injection of (35S) cysteine into the supraoptic nucleus, had accumulated in the neural lobe. Dehydration for 3 days of non-colchicine-treated rats was followed by a 100% reduction of neurophysin-bound radioactivity. When colchicine was given prior to dehydration, the reduction of radioactive neurophysin was less marked. Colchicine treatment alone was likewise followed by a lowering of protein-bound radioactivity in the neural lobe, which may indicate that colchicine, in addition to blocking the rapid axonal transport of neurosecretory material, also impedes the slow transport. The release of radioactive neurophysin in response to depolarizing concentration of potassium in vitro was diminished in the presence of colchicine, the reduction being most pronounced after colchicine treatment in vivo. The biochemical data prove the view that colchicine inhibits the release of neurosecretory material from the neural lobe. The ultrastructural findings support the biochemical data. Thus, colchicine treatment alone or followed by dehydration induced a marked increase in the number of organelles, especially of mitochondria and dense bodies. There was a marked increase in the number of enlarged axons filled with dammed organelles in the infundibulum and neurohypophysis. There was an accumulation of dense core vesicles and microvesicles in the axonal terminals in the neurohypophysis after treatment with either colchicine or colchicine followed by dehydration, which indicates an impediment of the release process. Dehydration alone induced a depletion of the dense core vesicles in the terminals. Out from the combined biochemical and ultrastructural findings possible mechanisms for the action of colchicine are discussed.
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  • 184
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    Cell & tissue research 142 (1973), S. 479-513 
    ISSN: 1432-0878
    Keywords: Median eminence (Frog) ; Tubero-hypophysial system ; Neurosecretory axon types ; Release phenomena ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary By means of electron microscopy, in the median eminence of Rana temporaria, the terminal arborizations of axons of six different types of neurosecretory cells, located in the pars ventralis of the tuber cinereum, were identified. In addition, phenomena connected with the release of neurosecretory material from the axon terminals of these neurosecretory cells into the blood capillaries of the median eminence are described. Preliminary results suggested the existence, in the median eminence, of additional different neurosecretory axon types which could also belong to corresponding neurosecretory cell types probably located in the apical part of the pars ventralis of the tuber cinereum. Moreover, in the external region of the normal median eminence, separate monoaminergic nerve fibres were tentatively identified. Arguments are adduced which plead (1) against the assumption that the ependyma or the pituicytes of the median eminence could produce adenohypophysiotropic hormones; (2) against the inference that the ependymal cells of the median eminence might be involved in the transport of adenohypophysiotropic hormones from the cerebrospinal fluid into the blood capillaries of the median eminence.
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  • 185
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    Cell & tissue research 142 (1973), S. 465-477 
    ISSN: 1432-0878
    Keywords: Rabbit thymus ; Ketosteroids ; Granulated cells ; Histochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Topochemisch konnten im Kaninchenthymus Ketosteroide nachgewiesen werden, für deren Vorhandensein die chemische Analyse von Thymuslipidextrakten Hinweise ergeben hatte. Die Darstellung der Ketosteroide erfolgte mit der NAHD-Reaktion (Camber, 1949). Diese Befunde dürften als spezifisch gelten, da eine Verfälschung durch freie Gewebsaldehyde, Plasmalogene (Gomori, 1952) und Corticosteroide (Khanolkar et al., 1958) ausgeschlossen wurde. Mit Hilfe der Camber-Methode konnten Granula bestimmter Zellen des Kaninchenthymus selektiv dargestellt werden, die auf Grund morphologischer Kriterien in zwei Gruppen unterteilt wurden. Die Zellen liegen im gesamten Thymusparenchym sowie im Bindegewebe der Septen und der sogenannten „Kapsel“. Prädilektionsorte stellen die Umgebung der Hassallschen Körperchen, die Mark-Rinden-Grenze, der intra- und perivasale Raum sowie die subkapsuläre Zone dar. Beide Zellgruppen sind Sudan III-, PAS- und Eosin-positiv, besitzen eine ausgeprägte gelbgrüne Eigenfluoreszenz und können differentialdiagnostisch gegen Mastzellen abgegrenzt werden. Elektronenmikroskopisch zeigen beide Zellgruppen zahlreiche Übereinstimmungen mit Reifestadien eosinophiler Knochenmarkszellen.
    Notes: Summary Ketosteroids were demonstrated topochemically in the rabbit thymus following indications given by chemical analysis of thymus lipid extracts. They were revealed by means of the NAHD-reaction (Camber, 1949). The results are thought to be specific, because adulteration by free tissue aldehydes, plasmalogens (Gomori, 1952) and corticosteroids (Khanolkar et al., 1958) can be excluded. The Camber-method selectively reveals the presence of two groups of morphologically differentiable granules in specific rabbit thymus cells which are distributed throughout the entire thymic parenchyme as well as in the connective tissue of the septa and the in so-called “capsule”. They are mainly seen in the vicinity of Hassall's bodies, in the zone between medulla and cortex, the intra- and perivascular space and in the subcapsular space. Both cell groups are Sudan III-, PAS- and eosin-positive, show intensive yellow-green primary fluorescence and can be distinguished from mast cells by differential diagnosis. Electron microscopy reveals that both cell groups show many similarities with the maturation phase of bone marrow eosinophils.
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  • 186
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    Cell & tissue research 143 (1973), S. 273-290 
    ISSN: 1432-0878
    Keywords: Muscle fiber types ; Atlantic hagfish (Myxine glutinosa, L.) ; Myosatellite cells ; Intranuclear rodlets ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Four types of striated muscle fibers with distinctive ultrastructure were defined in the Atlantic hagfish (Myxine glutinosa, L.): “white”, “intermediate”, and “red” fibers of m. parietalis, and “red” fibers of m. craniovelaris. “White” fibers are thick, contain very few mitochondria and fat vacuoles, and possess distinct and separate myofibrils with thin Z-disks and distinct M-lines. “Intermediate” fibers are thinner, possess largely similar myofibrils that often are even better separated due to a higher content of fat vacuoles and especially mitochondria and glycogen granules. “Red” fibers of m. parietalis contain large amounts of mitochondria, fat vacuoles, and glycogen granules. Their myofibrils possess M-lines, and although branching more, the myofibrils of “red” fibers conform with a “Fibrillenstruktur” pattern like those of “white” and “intermediate” fibers. “Red” fibers of m. craniovelaris are very thin, possess many smaller fat vacuoles, and large amounts of mitochondria and glycogen granules. The myofibrils are significantly thinner than in m. parietalis fibers, run as quite independent well separated units, possess thicker Z-disks, and lack M-lines. Large amounts of myosatellite cells are associated with these “red” fibers. Triads are located near A/I-junctions in all four fiber types and occur irregularly, the density of triads being different in the various fiber types.
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  • 187
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    Cell & tissue research 143 (1973), S. 343-353 
    ISSN: 1432-0878
    Keywords: Surface coat (Paramecium aurelia) ; Ruthenium red staining ; Enzyme treatment ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The plasma membrane of Paramecium aurelia is covered with a ruthenium red stainable surface coat. Results obtained after digestion with pronase, trypsin and neuraminidase suggest the glycoprotein nature of this structure. Lipid extraction also affects the surface coat forming material. The results are consistent with the model proposed by Ginsburg and Kobata dealing with spatial configuration of the surface coat components.
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  • 188
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    Keywords: Integument ; Hirudinea ; Sensory organs ; Nerves ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé Le tégument de Glossiphonia complanata comprend, outre les cellules épithéliales banales, de nombreux organes particuliers ou organes de Bayer, regroupés essentiellement sur la face dorsale de l'animal. Ils sont formés par une cellule apicale saillante enchassée dans une cellule musculaire en anneau. L'ensemble de ces formations est étudié du point de vue ultrastructural. Des cellules épithéliales partent des fibres nerveuses afférentes, sans doute vecteur des perceptions de stimuli mécaniques de pression au niveau du tégument; la réponse se faisant sans doute par la contraction de la cellule basale de chaque organe de Bayer, innervée par des fibres nerveuses efférentes, entrainant la saillie de la cellule apicale. Le hérissement de ces nombreuses papilles du tégument dorsal pourrait être un signal perçu par le partenaire sexuel, chez cette Hirudinée à fécondation hypodermique.
    Notes: Summary The integument of Glossiphonia complanata, built up by epithelial cells, contains numerous particular organs (Bayer organs), mainly on the dorsal side of the animal. They consist of a protuberant apical cell, which is surrounded by a ring-shaped muscle cell. All the integumentary formations are studied from an ultrastructural point of view. From the epithelial cells issue afferent nerve fibres, considered as vectors of the perception of mechanical stimuli of pressure at the level of the integument; the response no doubt operating by the contraction of the basal muscle cell of each Bayer organ, innervated by efferent nerve fibres, bringing forth the protrusion of the apical cell. The erection of these numerous papillae of the dorsal integument might be a signal perceived by the sexual partner, fecundation occurring in this group of leeches under the integument.
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  • 189
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    Cell & tissue research 143 (1973), S. 505-515 
    ISSN: 1432-0878
    Keywords: Endoplasmic reticulum ; Paracervical ganglion (Rat) ; Neurosecretion ; Electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Two new types of structure of the cytoplasm of an autonomic neuron were described: (1) Inclusions of the rough ergastoplasmic reticulum, which were named “ergastosomes”, contain finely granular material with moderately electron opaque staining with both glutaraldehyde-OsO4 and KMnO4 fixations. A short comment was made on the nature of the contents of the ergastosomes. (2) Tubular formations of endoplasmic reticulum were found in the axons and/or dendrites of the paracervical ganglion.
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  • 190
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    Cell & tissue research 143 (1973), S. 517-526 
    ISSN: 1432-0878
    Keywords: Middle ear ; Guinea pig ; Capillary permeability ; Horseradish peroxidase ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The middle ear capillaries of the guinea pig have fenestrated endothelium, and the intercellular clefts are closed by tight junctions. Intracardially injected horseradish peroxidase penetrates the fenestrae of the endothelium and gains access to the extra-cellular space beneath the epithelium, and the intercellular clefts of the epithelium.
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  • 191
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    Keywords: Nervous system ; Stick insect ; Blood-brain barrier ; Development ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fat body sheath which surrounds the ventral nerve cord of the adult stick insect, Carausius morosus, is absent in the hatchling. Since the haemolymph sodium ion compositions of the two stages are similar, it is suggested that the fat body sheath is not a site of a blood-brain barrier dealing with extra-axonal regulation of sodium. Similarities of ultrastructure in connectives of adults and hatchlings are demonstrated, and tight junctions are shown to occur in perineural cells of both stages. The possible significance of this to the blood-brain barrier of this insect is discussed.
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  • 192
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    Cell & tissue research 145 (1973), S. 363-388 
    ISSN: 1432-0878
    Keywords: Heart ; Monkey ; A-V node and bundle ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The atrio-ventricular (A-V) node of the monkey heart is located in the focus of converging atrial muscle. Three main atrial muscle strands, coming from the atrio-ventricular ring, the dorsal wall of the atria, and the ventral part of the atrial septum, converge in the nodal region where they overlap and are interconnected. The junctional type of fibers establishing interconnection between the atrial muscle and the nodal tissue are not strictly localized at the periphery of the node, but may be traced further, along the A-V ring and coronary sinus. The A-V node consists of a loose peripheral and a compact distal part. In the former, typical nodal fibers were found, while the compact part shows an important individual variation in structure and cell-types. In some monkey hearts, the nodal fibers gradually become broader bundle fibers, while in other specimens the junctional fibers surround the compact part and than penetrate the nodal-His (N-H) region. These junctional fibers become nodal fibers or are in terminal contact with large clear cells up to 50 μ in diameter. Clear cells of various diameters are often intercalated between the cell rows of the nodal and His-bundle fibers and may form a distinct cellular gate between the node and the His-bundle.
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  • 193
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    Cell & tissue research 145 (1973), S. 167-170 
    ISSN: 1432-0878
    Keywords: Striated muscle ; Chick ; Sarcomere formation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Sarcomere assemblage in striated muscle of the early developing chick embryo was studied with the electron microscope. In myogenic chick somites, non-striated myofibrils are seen with the electron microscope, prior to striated ones. These crude myofibrils are traversed at regular periodic intervals by a tubular system which is associated with dense Z-line material shortly after its appearance. Longer sarcomeres as well as banding patterns similar to those found in mature striated muscle follow and possibly depend on prior Z-line formation.
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  • 194
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    Cell & tissue research 145 (1973), S. 191-211 
    ISSN: 1432-0878
    Keywords: Heart ; Monkey (Macaca mulatta) ; Conducting system ; Atrium ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the sino-atrial (S-A) node of the monkey heart two types of muscle cells occur: 1. typical nodal cells which are the predominant cells and form the nodal fibers. 2. “Intercalated clear cells” with various diameters (4 to 12 μm) and containing poorly developed myofibrils, rich in glycogen and demonstrating poor staining properties. These latter cells are dispersed, few in number, and never form discrete fibers of themselves, but are intercalated between the cell rows of the typical nodal fibers. Such intercalated clear cells become more numerous at the periphery of the node. Interconnection between the S-A node and the conventional atrial muscle is established by a progressive transformation of nodal fibers into atrial fibers producing an intermediate (or junctional) type of fiber at the nodal periphery. However, in addition, few nodal fibers make direct contact with the atrial cardiocytes. Our light and EM studies have failed to prove the existence of truly specialized internodal pathways. Nevertheless intercalated clear cells, nodal-like cells, junctional or intermediate type of cells are relatively frequent in valvular regions (Thebesian, Eustachian, A-V, fossa ovalis) and less frequent in other regions of the atrial wall.
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  • 195
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    Cell & tissue research 146 (1973), S. 425-438 
    ISSN: 1432-0878
    Keywords: Pancreatic islets ; New cell types ; Teleost ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The pancreatic islets ofCarassius carassius have been studied by electron microscopy. 1. Besides A-, B- and D-cells, two new cell types, the fourth and the fifth, have been identified. The fourth cell type is numerous; it occurs interposed among the other types of islet cells or in small clusters. The secretory granules (90–280 mg in diameter) are round or oval and usually with much lower electron density than α- and δ-granules. The secretory granules of the fifth type of cell (approximately 140–240 mμ in diameter) contain finely granular material and an electron dense core that is round or often tetra- or hexagonal. 2. The islet cells with clear cytoplasmic matrix generally contain large numbers of fine, agranular and cored vesicles 400–680 Å in diameter. They appear, in bead-like chains, or randomly scattered throughout the cytoplasm, or often clustered in aggregates close to the secretory granules and show evidence of incorporation into the secretory granules. The two types of vesicles may be formed by constriction or pinching-off of the tubular smooth endoplasmic reticulum.
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  • 196
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    Cell & tissue research 147 (1973), S. 87-105 
    ISSN: 1432-0878
    Keywords: Motor nerve terminals ; Myxine glutinosa (L.) ; Elongated vesicle profiles ; Dense-core vesicles ; Fixation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary “White” and “intermediate” parietal muscle fibers of Myxine are innervated focally at one end. Most synaptic vesicles are “empty”. These terminals also contain 1–2% large 800–1.100 Å dense-core vesicles. “Red” fibers of parietal and craniovelar muscle are innervated in a distributed fashion, and the presynaptic profiles contain a higher number of large dense-core vesicles (averaging 9% and 15%, respectively; up to 37%). For all terminals the synaptic gap is 450–600 Å wide, and postsynaptic folds are absent. “Empty” synaptic vesicles exist as round or elongated profiles. The proportion of elongated profiles increases by formation from round ones when increasing the molarity of the buffer in the aldehyde fixative. Furthermore, the proportion of elongated vesicle profiles in terminals on Myxine “white” fibers at different buffer molarities, is identical with that in mammalian motor terminals at similar molarities. On this basis the significance and mode of formation of elongated vesicle profiles is discussed. The conclusion is made that the susceptibility of “flattening” depends on the osmotic pressure of the vesicle contents once the aldehyde has influenced the vesicle membrane. The different vesicle populations in terminals on different types of muscle fibers are significant. Terminals on “red” fibers probably contain serotonin (5-HT) either as sole transmitter or in addition to acetylcholine.
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  • 197
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    Cell & tissue research 144 (1973), S. 467-473 
    ISSN: 1432-0878
    Keywords: Muscle ; Colchicine ; Myofibrils ; Acid phosphatase ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Colchicine was intraperitoneally administered chronically to adult male Sprague-Dawley rats. The ultrastructural study of hind-limb muscles revealed that myofilament desorientation resulted. Bundles of myofilaments were found coursing perpendicular or oblique to the longitudinal axis of the muscle fiber. It is concluded that a colchicine-sensitive factor is involved in maintaining normal orientation of myofibrils in mature muscle. Also found in the sarcoplasm of the colchicine treated animals were complex spheromembranous bodies. These bodies enveloped mitochondria or other organelles and appeared to be derived from the sarcoplasmic reticulum. The lysosomal nature of these bodies is indicated by the localization of acid phosphatase activity in them. Acid phosphatase activity was also displayed in the sarcoplasmic reticulum. The spheromembranous bodies seem to be part of a sarcotubulo-lysosomal system in skeletal muscle.
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  • 198
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    Keywords: Glandular cells ; Isopoda ; Golgi apparatus development ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé Dans ce travail, les auteurs présentent les résultats de leurs recherches, au niveau de la microscopie électronique, concernant les processus sécrétoires dans les cellules glandulaires de la partie antérieure, réniforme, du canal déférent chez Porcellio scaber Latreille. Les observations sont dirigées spécialement sur l'appareil de Golgi qui est poursuivi dans toutes les phases d'élaboration de la sécrétion, dans laquelle il paraît avoir un rôle essentiel. Après avoir obtenu la conviction que, dans le processus délaboration de la sécrétion, les dictyosomes s'usent complètement et disparaissent, les auteurs recherchent l'origine de nouveaux dictyosomes qui participeront au cycle de sécrétion suivant.
    Notes: Summary In this paper the authors present an investigation at infrastructural level concerning the secretory process in the glandular cells of the anterior kidney-like portion of the deferent ducts in Porcellio scaber Latreille. The observations are directed especially to the Golgi apparatus in all phases of elaboration of secretion in which it seems to have an essential role. After ascertaining that in the process of elaboration of secretion the dictyosomes waste away and disappear, the authors investigated the origin of the new dictyosomes that become involved in the following secretory cycle.
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  • 199
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    Cell & tissue research 144 (1973), S. 539-547 
    ISSN: 1432-0878
    Keywords: Catalase ; Peroxisomes ; Fibroblasts ; Enzyme cytochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The connective tissue of the mucosa of the respiratory tract, of the gastric mucosa and of the mucosa of the tongue was investigated in mice. The tissue was fixed in glutaraldehyde and incubated in an alkaline DAB-medium to demonstrate the peroxidatic activity of catalase. In fibroblasts and fibrocytes, as well as in lymphoid cells, membrane bounded particles from 0.10 to 0.25 μm in diameter were found, whose matrices were intensely stained by the histochemical reaction. The reaction is inhibited by the addition of 2×10−2 M 3-amino-1,2,4-triazole. In connective tissue cells of specimens, which were not reacted to demonstrate catalase activity, these organelles show a granular matrix of moderate electron density. They lack a crystalline core. The possibility that these catalase-positive particles (CPs) represent peroxisomes is discussed.
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  • 200
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    Cell & tissue research 137 (1973), S. 97-109 
    ISSN: 1432-0878
    Keywords: Amoeba proteus ; Adsorptive function of mucoid layer ; Significance for induced endocytosis ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die Mucoidschicht von Amoeba proteus enthält saure Mucopolysaccharide und ist funktionell einem Kationenaustauscher vergleichbar. Schwermetallpartikel und Proteine werden in Abhängigkeit vom pH-Wert des Kulturmediums in unterschiedlich starken Mengen an die Mucoidfilamente gebunden. Die dem Plasmalemm unmittelbar aufliegende globuläre Grundschicht besitzt dagegen für die untersuchten Substanzen keine Adsorptionsfunktion und unterscheidet sich demnach sowohl physiologisch als auch chemisch von der filamentartigen Zone. Quantitative Messungen über die pH-abhängige Anlagerung von Ferritin haben ergeben, daß die Mucoidfilamente in der Lage sind, Kationen aus dem Kulturmedium bis zu einer um das 17fache höheren Konzentration anzureichern. Die Ergebnisse der vorliegenden Untersuchung sprechen dafür, daß die Anreicherung derartiger Substanzen an der Zelloberfläche eine notwendige und physiologisch sinnvolle Voraussetzung für die Auslösung einer induzierten Endocytose darstellt.
    Notes: Summary The mucoid layer of Amoeba proteus contains acid mucopolysaccharides, which are involved in the exchange of cations. Depending on the pH of the external medium, different amounts of heavy metal particles and proteins are bound to the mucoid filaments. The globular ground layer, which is directly apposed to the plasma membrane does not bind any of the substances studied and, therefore, differs from the mucoid filaments in function as well as chemical nature. Measurements of the pH-dependent adsorption of ferritin demonstrate that the mucoid filaments are able to accumulate cations in concentrations 17 times that of the external medium. These results suggest that the accumulation of substances at the cell surface is a prerequisite for the initiation of induced endocytosis.
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