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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 176 (1977), S. 69-90 
    ISSN: 1432-0878
    Keywords: Testis ; Sertoli cell ; Cell culture ; Estradiol production
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A cell line obtained from isolated seminiferous tubules of adult rat testis has been studied “in vitro” over a period of 35 days. Light and electron microscopic studies performed from hour 2 to the end of culture have shown the presence of a monomorphic cell population. After 5–6 days of culture the cells formed a monolayer. The cytoplasm of the cells contained numerous lipid bodies and produced numerous projections. The nucleus showed several indentations and one or more nucleoli. From the 9th to the 15th day of culture the cells developed a large amount of endoplasmic reticulum, Golgi apparatus and aggregates of electron dense granules. From the 20th to 40th day the cell cultures progressively degenerated. Immunochemical analysis of the culture medium revealed the presence of estradiol-17β, which reached its maximum production rate from the 8th day to the 18th day of culture. Corresponding to cell involution estradiol concentration underwent a rapid decrease. On the basis of morphological and biochemical data the cells could be considered Sertoli cells. This work was supported by Grants n.∘ 74.00155.04 and n.∘ 75.01224.04 from the Consiglio Nazionale delle Ricerche (C.N.R.), Rome, Italy, and by Istituto di Ricerca F. Angelini, Rome, Italy
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 213 (1980), S. 159-178 
    ISSN: 1432-0878
    Keywords: Testis ; Meiotic nuclei ; Myosin ; Actin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Smooth muscle heavy myosin and actin have been detected in mouse and rat meiotic chromosomes, by indirect immunofluorescence performed on testis cryostat sections and isolated germ cells. Both contractile proteins are detectable in the nuclei of meiotic cells during the first prophase. The appearance and disappearance time of myosin and actin, however, is not synchronous. While actin is visible in small spots from resting to late diplotene spermatocytes, myosin appears as filaments in the primary spermatocytes from the zygotene to the early stage of diplotene. The number of myosin filaments in the pachytene spermatocytes corresponds to the number of bivalent chromosomes, whereas actin spots constantly outnumber the pairing chromosomes by two units. These immunochemical observations suggest that the two contractile proteins are associated with the synaptonemal complex (SC). Myosin seems to be associated with the central region of the SC, while actin is present in its basal knob which is in connection with the nuclear membrane. The difference in number between myosin filaments and actin spots appears to be related to the peculiar behaviour of the pairing sex chromosomes. The presence of contractile proteins in the nuclei of primary spermatocytes seems to suggest that they might play a role in the process of pairing of homologous chromosomes.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 195 (1978), S. 81-97 
    ISSN: 1432-0878
    Keywords: Tendon ; Tendon regeneration ; Contractile proteins ; Rabbit
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The regenerated tissue which fills the gap between the stumps of sectioned and unsutured rabbit calcaneal tendon was studied by immuno-fluorescence, light and electron microscopy from 2 days to 30 weeks after surgery. In the early stages, the newly formed tissue consisted of few connective tissue cells of variable shape dispersed in an abundant intercellular matrix. At 7 days after tenotomy most of the cells were spindle shaped and arranged along the major tendon axis. They showed a well developed rough endoplasmic reticulum, a prominent Golgi complex and bundles of thin and thick filaments. Moreover, they appeared intensely stained when treated with anti-actin and anti-myosin sera. The bulk of the intercellular matrix consisted of bundles of collagen fibers, mostly arranged parallel to the cells. In the subsequent stages the regenerating tissue became more compact, acquiring the morphological characteristics of tendon tissue. At 30 weeks after tenotomy, however, it did not show yet the typical texture of the normal adult tendon. The tenocytes were more numerous and less uniformly distributed, and contained a greater amount of ergastoplasm and contractile proteins. The collagen fibers were similar in size to those of the neonatal normal tendon and the elastic fibers appeared often immature. These findings suggest that, at least on the experimental conditions under which this study was performed, the regenerated tendon does not acquire the typical morphology of the normal adult tendon, possibly owing to the reduced mechanical stress acting on it.
    Type of Medium: Electronic Resource
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