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  • 1
    Electronic Resource
    Electronic Resource
    Cellular architecture of the lamina propria of human seminiferous tubules (1990)
    Springer
    Cell & tissue research 262 (1990), S. 253-261 
    Details
    ISSN: 1432-0878
    Keywords: Lamina propria ; Seminiferous tubule ; Myofibroblasts ; Immunoreactivity ; Man
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The lamina propria of human seminiferous tubules is composed of 5 to 7 cellular layers separated by laminae of extracellular connective-tissue components. By means of immunocytochemical methods the different nature of the cellular layers could be defined for the first time. Based on the light-microscopic demonstration of both desmin-like and vimentin-like immunoreactivity in the inner 3 to 4 layers of the lamina propria, these cells can be identified as myofibroblasts. The outermost one or two cellular layers, on the contrary, only show a vimentin-like immunoreactivity indicating the pure fibroblastic nature of these cells. Therefore, the outermost cellular layers are suggested to be derivatives of the interstitium. In cases of disturbed spermatogenesis, the lamina propria is frequently considerably thickened by an increase in the extracellular matrix components between the cellular layers. Whereas the ultrastructural localization of laminin-, collagen type-IV- and fibronectin-like immunoreactivity remains unaffected in the thickened lamina propria, the desmin-like immunoreactive cells of the inner layers strongly decrease in number and staining intensity. Most probably, the myofibro-blasts lose their myoid characteristics to participate in the secretion of increased amounts of extracellular matrix components, which in turn presumably block the mediation of the lamina propria between the interstitium and the germinal epithelium. It is still unclear whether the thickened lamina propria provokes the disturbance of spermatogenesis or vice versa.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00309880
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  • 2
    Electronic Resource
    Electronic Resource
    Different epithelia in the distal human male urethra (1991)
    Springer
    Cell & tissue research 264 (1991), S. 23-32 
    Details
    ISSN: 1432-0878
    Keywords: Male urethra ; Urethral epithelium ; Immunocytochemistry ; Ultrastructure ; Man
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distal segment of the human male urethra, in particular the fossa navicularis, was studied with light- and electron microscopy as well as by means of histochemical and immunocytochemical methods. The fossa navicularis of the urethra contains a circumscribed zone of extremely thick, non-keratinized stratified squamous epithelium composed of cells containing a large amount of glycogen. These cells lack acid phosphatase activity and lysozyme-like immunoreactivity, both of which can be demonstrated to varying extents in the other zones of the distal male urethra. These glycogen-rich cells are considered to be the substrate for an endogenous flora of lactobacteria, whereas the acid-phosphatase activity and the lysozyme-like immunoreactivity indicate the presence of macrophages and the secretion of bactericidal agents at the epithelial surface. These observations suggest that the different zones with heterogeneous properties in the distal male urethra probably represent a defense system against the invasion of pathogenic microorganisms. Moreover, the glycogen-rich zone, which resembles the glycogen-rich epithelium of the vagina, is estrogen-dependent. This is demonstrated in cases of sex reversal in which after long-lasting estrogen treatment the glycogen-rich zone becomes extremely extended by displacement of the neighbouring epithelium.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00305719
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  • 3
    Electronic Resource
    Electronic Resource
    Morphogenesis and fate of the residual body in human spermiogenesis (1985)
    Springer
    Cell & tissue research 240 (1985), S. 303-309 
    Details
    ISSN: 1432-0878
    Keywords: Residual body ; Testis ; Sertoli cells ; Spermatogenesis ; Man
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the human testis the formation of the residual body of the spermatid and its morphological changes during and after spermiation were studied by means of electron microscopy. The caudal cytoplasmic mass of the late spermatid contains a Golgi complex, mitochondria, annulate lamellae, a chromatoid body, flower-like structures, ribosomes, a few large vacuoles, myelin-like membrane profiles and sporadic lipid droplets. When, by detachment of the caudal cytoplasm from the free spermatozoon, the residual body is formed, the chromatoid body has disappeared; the mitochondria are clustered peripherally; the ribosomes appear as a single complex in contact with a large vacuole containing granular material; in place of the Golgi complex aggregations of vesicles are present. The lipid droplets remain unchanged. The residual bodies or their fragments are either extruded via the seminiferous tubular lumen into the excurrent ducts or they are engulfed by Sertoli cells where in the supranuclear region the successive steps of decomposition can be observed. The participation of the various constituents in the disintegration of the residual body is discussed. In contrast to other mammalian species, in man the sporadic lipid droplets seem to be of minor importance in the fate of the residual body.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00222339
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  • 4
    Electronic Resource
    Electronic Resource
    Leydig cell mitoses in human testes bearing early germ cell tumors (1989)
    Springer
    Cell & tissue research 255 (1989), S. 475-479 
    Details
    ISSN: 1432-0878
    Keywords: Leydig cells ; Mitosis ; Testis ; Germ cell tumor ; Man
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Numerous mitoses were noted in testicular tissue from adult men with early germ cell tumors. More than 15 Leydig cells undergoing mitosis were found in the interstitial compartment. The presence of specific crystalline intracytoplasmatic inclusions demonstrated for the first time that differentiated Leydig cells are capable of proliferation. Occasionally cells are difficult to discriminate during mitosis. To establish reference criteria, the light- and electron-microscopic features of the following mitotic cells were examined: Leydig cells, fibroblasts, perivascular cells, peritubular cells, and lymphocytes. Supplementary mitoses in germ cell tumors and in a case of Leydig cell tumor were investigated. In the literature, only single reports of mitoses in Leydig cells are available. The frequent incidence of Leydig cell mitosis in early germ cell tumors may be due to the presence of growth-promoting factors in the testicular tissue.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00218781
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  • 5
    Electronic Resource
    Electronic Resource
    Distribution and fine structure of the lymphatic system in the human testis (1979)
    Springer
    Cell & tissue research 200 (1979), S. 15-27 
    Details
    ISSN: 1432-0878
    Keywords: Lymph vessels ; Testis ; Man ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution of lymph vessels in the human testis was investigated using ink injection methods, and light and electron microscopy. Lymph capillaries occur in the septula testis but are absent in the intertubular tissue. They consist of endothelial cells provided with an incomplete basal lamina and anchoring filaments of the adjacent connective tissue. Frequently, the endothelial cells are separated by gaps measuring up to 2μm. The lymph capillaries of the septula testis are connected to lymph vessels in the rete testis and tunica albuginea. These vessels have occasional smooth muscle cells and valves. At the posterior margin of the testis, the network of lymph vessels merges into collecting ducts, which together with vessels derived from the rete testis are drained by the lymphatic system in the spermatic cord.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236883
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  • 6
    Electronic Resource
    Electronic Resource
    Intraepithelial lymphocytes and macrophages in the human epididymis (1983)
    Springer
    Cell & tissue research 233 (1983), S. 517-521 
    Details
    ISSN: 1432-0878
    Keywords: Lymphocytes ; Macrophages ; Epididymis ; Man
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The epididymides from 7 young adults and 5 older patients with prostatic cancer were investigated by means of light and electron microscopy. The existence of lymphocytes and macrophages between epithelial cells of various segments of the ductuli efferentes and the ductus epididymidis is proven, and the distribution and morphology of these cells are described. A possible relationship between these two intraepithelial cell types, as well as their presumptive role with regard to an immunological barrier-function are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00212221
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