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  • 1985-1989  (3)
  • 1975-1979  (3)
  • 1
    Electronic Resource
    Electronic Resource
    Granule formation and polarity of the Golgi apparatus in neutrophil granulocytes of the rat (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 223 (1989), S. 128-138 
    Details
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The formation of granules in neutrophil (heterophil) progenitor cells was examined with the electron microscope in sections of rat bone marrow fixed in 2% glutaraldehyde and postfixed with reduced osmium (Karnovsky:Proceedings of the 11th Meeting, American Society of Cell Biologists, Abstr. 284, p. 146, 1971). The cells were also osmicated in 2% osmium tetroxide for 36 hours at 37%C to outline the osmiophilic element usually observed on the cis-face of the stacks of saccules of the Golgi apparatus of various cell types. In myeloblasts, which do not produce granules, the cis-osmiophilic element (CE) was found on the concave face of the C-shaped Golgi stacks, while the primary (azurophilic) granules fromed in relation to elements on the concave aspects of the stacks. In myleocytes, the situation was reversed: the CE was found on the concave face of the Golgi stacks, while the secondary (specific) granules were seen forming in relation to elements on the convex aspect of the stacks. Finally, in metamyelocytes and mature neutrophils in which no granule formation took place, the appearance on Golgi stacks varied: they were either flat or C-shaped. The CE was indiscriminately found on one face or the other of the flat Golgi stacks of metamyetocytes and on the convex or concave faces of the C-shaped Golgi stacks of mature neutrophis.Using the cis-osmiophilic-element as a marker of the cis-face of the stackedGolgi elements, it thus appeared that despite marked changes in the configuration and orientation of the stacks the cis-trans polarity of the stacked elements was maintained throughtout granulopoiesis. In addition the primary and secondary granules that appeared sequentially in promyelocytes and myelocytes were both seen to form in relation to trans-elements of the Golgi apparatus.
    Additional Material: 20 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1092230204
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  • 2
    Electronic Resource
    Electronic Resource
    Degeneration of germ cells in normal, hypophysectomized and hormone treated hypophysectomized rats (1977)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 187 (1977), S. 347-365 
    Details
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: In normal adult rats some germ cells degenerate at several vulnerable steps of spermatogenesis. These are the type A spermatogonia, midpachytene spermatocytes, primary and secondary spermatocytes which degenerate during their respective maturation divisions and step 7 and 19 spermatids. In the present study, these degenerating cells were examined under the electron microscope, and their frequency was determined in toluidine blue stained semithin sections of testes from normal, hypophysectomized (at 5.5 days after operation) and hypophysectomized rats injected with FSH and LH separately or in combination. With the exception of the step 19 spermatids, the degenerating germ cells underwent necrosis in vacuolated spaces delimited by Sertoli cells. In the case of the affected step 19 spermatids, an apical cytoplasmic process of the Sertoli cell initially ensheathed a long segment of their flagellum, and then each degenerating cell was drawn deep in the seminiferous epithelium where it was phagocytozed by the Sertoli cell. Soon after hypophysectomy the incidence of degenerating mid-pachytene spermatocytes, step 7 and 19 spermatids which are present in stages VII or VIII of the cycle of the seminiferous epithelium, increased significantly. In contrast the number of degenerating primary or secondary spermatocytes during the meiotic divisions seen in stage XIV of the cycle or of any other germinal cell was not significantly modified. While the injection of FSH alone had no influence on the number of degenerating cells in hypophysectomized rats, injections of LH at the two doses administered (0.7 μg or 20 μg) reduced significantly the number of degenerating cells seen in stages VII-VIII of the cycle; combined injections of FSH and LH (20 μg) reduced the number of these degenerating cells to the normal low values. Thus it appeared that the mid-pachytene spermatocytes and the step 7 and 19 spermatids, all present in the adluminal compartment of the seminiferous epithelium in stages VII or VIII of the cycle, were more sensitive to the presence of absence of gonadotropic hormones than the other germ cells present in the seminiferous epithelium.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1091870307
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  • 3
    Electronic Resource
    Electronic Resource
    Glycoprotein synthesis in the Golgi apparatus of spermatids during spermiogenesis of the rat (1985)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 213 (1985), S. 33-43 
    Details
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: During steps 1-7 of spermiogenesis the Golgi apparatus contributes to the formation of the acrosomic system which develops at the surface of the nucleus. Later, in step 8, the Golgi apparatus detaches from the acrosome and remains suspended in the elongated cytoplasm until it degenerates during step 16. Using 3H-fucose as a tracer and the radioautographic technique, we observed that the Golgi apparatus incorporates the tracer and delivers the labeled glycoproteins to the developing acrosomic system during steps 1-7 of spermiogenesis, to multivesicular bodies during steps 1-9, and to the remaining cytoplasm and plasma membrane during steps 1-15. Throughout these steps of spermiogenesis the Golgi apparatus does not show major changes in structure; it is composed of a cortex made up of connected stacks of saccules and a medulla showing a loose aggregate of vesicular profiles. Glycoprotein synthesis in this Golgi apparatus, before and after it contributes lysosomal glycoproteins to the growing acrosomic system, was quantitatively assessed in electron microscope EM radioautographs of tissue sections from animals sacrificed at 1, 4, 8, and 24 h of 3H-fucose injection. The incorporation of the labeled sugar was found to remain quantitatively similar during steps 1-15 of spermiogenesis, and therefore, no shift in glycoprotein synthesis took place following separation of the Golgi apparatus from the acrosomic system. Throughout these steps, fucose molecules are first incorporated in the cortex of the organelle and subsequently transported to the medulla, where they temporarily accumulate before being delivered, depending on the step of spermiogenesis, to the acrosomic system, to the multivesicular bodies, and also, presumably, to the plasma membrane.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1092130106
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  • 4
    Electronic Resource
    Electronic Resource
    Light microscopic immunocytochemical study of fibrous sheath and outer dense fiber formation in the rat spermatid (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 225 (1989), S. 46-55 
    Details
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The formation of the fibrous sheath (FS) and outer dense fibers (ODF), two major cytoskeletal components of the tail of spermatozoa, was analyzed in the seminiferous epithelium by immunoperoxidase techniques applied to paraffin-embedded testicular sections. Antibodies were prepared from purified FS and ODF fractions and from major 75 and 14.4 kDa FS polypeptides and major 32-26 14.4 kDa ODF polypeptides. The immunostaining results showed that the production of FS and ODF proteins appeared to be exclusive to step 9-19 spermatids and lasted over the duration of a full cycle of the seminiferous epithelium, or 12.8 days. During this period there was seemingly an initial lag of short duration between the synthesis and assembly of FS and ODF proteins followed by a long process of coordinated activity. Peak cytoplasmic immunoreactivity was reached in step 15 for FS proteins and midstep 16 for ODF proteins and and remained elevated thereafter for approximately 80 hr for both FS and ODF proteins. The immunoreactivity was more uniform and diffused for FS proteins and granulated or clumpy for ODF proteins. Assembly of FS proteins along the axoneme proceeded in a distal to proximal direction while for ODF proteins assembly proceeded in a proximal to distal direction. The main route of elimination of residual cytoplasmic FS and ODF proteins appeared to take place through the cytoplasmic droplets and residual bodies, respectively. There appeared to be no variation in step reactivity between the major ODF polypeptides tested and only minor variation in step reactivity between the major FS polypeptides tested. However, although the 14.4 kDa polypeptides of FS and ODF share antigenic determinants, they do not appear to be identical, because they presented different immunolocalizations during spermiogenesis and different directions of assembly along the axoneme.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1092250108
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  • 5
    Electronic Resource
    Electronic Resource
    Evolution of the endoplasmic reticulum during rat spermiogenesis (1978)
    New York, NY [u.a.] : Wiley-Blackwell
    American Journal of Anatomy 151 (1978), S. 191-211 
    Details
    ISSN: 0002-9106
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The endoplasmic reticulum (ER) was stained selectively by a sequence of uranyl acetate, lead and copper citrate, according to the method of Thiéry and Rambourg ('76), and then investigated in 0.5 to 2.0-μm-thick sections with the transmission electron microscope. Examination of photographic stereopairs allowed a three-dimensional visualization of the ER at various steps of spermiogenesis.During the Golgi and cap phases of spermiogenesis (steps 1-7, classification of Leblond and Clermont, '52a), the ER is distributed throughout the cytoplasm as a three-dimensional network of spherical and tubular cisternae connected by narrow tubules. In addition, a close network of tubular cisternae is located along the convex surface of the Golgi apparatus and lines the plasma membrane. Where the cell membrane joins that of another spermatid to form an intercellular bridge, this network extends across the bridge.During the acrosome phase (steps 8-14), the cytoplasm contains an abundant ER that shows the following modifications: (A) Along the inside and outside of the caudal tube the cisternae form long tubes or plates which run adjacent and parallel to the microtubules. These cisternae are connected by delicate lateral anastomoses; (B) Along the flagellum the ER forms a “fenestrated sleeve” made up of a close network of tubular cisternae; (C) Similar networks are organized as “fenestrated spherules” enclosing large vesicles seen throughout the cytoplasm; (D) At a short distance from the flagellum, the ER cisternae are continuous with a stack of annulate lamellae and an aggregate of radially arranged collapsed cisternae called the “radial body”.During the last or maturation phase (steps 15-19), the ER regresses. Thus, during the final steps in the formation of the flagellum, the ER network fragments and then most of the cisternae disappear from the cytoplasm. The “radial body” is the last element of the ER to be dissolved. Thus the ER undergoes extensive structural modifications during spermiogenesis, suggesting an active contribution of this organelle to the differentiation of the spermatid into a spermatozoon.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aja.1001510204
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  • 6
    Electronic Resource
    Electronic Resource
    Spermatogonial stem cells in the albino rat (1975)
    New York, NY [u.a.] : Wiley-Blackwell
    American Journal of Anatomy 142 (1975), S. 159-175 
    Details
    ISSN: 0002-9106
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The existence of two classes of spermatogonial stem cells in the rat testis, i.e., reserve type A0 spermatogonia and renewing, types A1-A4 spermatogonia, postulated by Clermont and Bustos-Obregon (′68), was reexamined in a quantitative analysis of type A spermatogonia in both whole mounts of tubules and in radioautographed sections of testes from animals killed at various times, up to 26 days, after one or multiple injections of 3H-thymidine.The cell counts obtained from whole mounts of tubules revealed that the number of isolated type A0 cells per unit area of limiting membrane remained constant throughout the cycle of the seminiferous epithelium. Paired type A0 spermatogonia also remained unchanged in number per unit area of basement membrane from stage I to stage VIII of the cycle. The low mitotic index of type A0 spermatogonia (0.1%) indicated that these cells were not actively involved in the production of spermatogonia or spermatocytes during each cycle of the seminiferous epithelium and thus were considered as reserve stem cells.The type A1 spermatogonia, which are formed during stage I of the cycle, remained resting until stage IX, when they undertook a series of four successive divisions resulting in the production of new type A1 and Intermediate-type spermatogonia. An analysis of the labeling indices of type A spermatogonia obtained from cell counts in radioautographed testicular sections after a single or multiple 3H-thymidine injections indicated that the percentages of labeled type A cells corresponded to the percentages of type A1-A4 at each stage, whereas the percentages of unlabeled type A cells corresponded to the percentages of type A0 spermatogonia obtained from counts of cells in whole mounts. This confirmed that type A0 cells were generally non-proliferative throughout the cycle of the seminiferous epithelium while the type A1-A4 spermatogonia underwent complete renewal during each cycle. The present results thus support the concept of the existence of two classes of spermatogonial stem cells in rats.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aja.1001420203
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