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  • 1
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 386 (1980), S. 239-248 
    ISSN: 1432-2307
    Schlagwort(e): Granular cells ; Leiomyosarcoma ; Smooth muscle cells
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A 78-year-old male presented a tumor mass in the left arm which was surgically excised. Part of the tumor, when examined by light microscopy, showed the characteristic cytological features of a leiomyosarcoma. Other areas of neoplasm comprised layers of tumoral spindle-cells surrounding abnormal blood vessels. Nests of similar neoplastic cells were observed in the intima and media of these blood vessels. Wide areas of neoformation were made up by interlacing bundles of acidophilic polyedral cells with large irregular nucleus. Mitoses were frequent. The cytoplasm contained a great number of granules intensely PAS stained with and without prior diastase digestion. Electron microscopic examination revealed that the granular cells possessed a continuous basal lamina, numerous pinocytotic vesicles and abundant 80–150 Å microfilament bundles. Within the microfilament bundles, as well as apposed to the plasma membrane, electrondense bodies were often found. Granules contained degenerated organelles and probably corresponded to digestive vacuoles. In the intercellular spaces, fibrous long-spacing collagen was seen. The transition zone between the leiomyosarcoma cells and the granular cells showed intermediate cell types, with few granules and abundant microfilaments. The origin of granular cells from smooth muscle cells of blood vessels is discussed.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    ISSN: 1432-2056
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract All musculature examined in the tiny, 0.3-mm, marine Antarctic mite Halacarellus thomasi (i.e. body and appendages) appeared ultrastructurally to be of the transversely striated type with continuous Z-lines. Tubules of sarcoplasmic reticulum lay among the myofibrils. The complexity of the sarcotubular system, sarcomere lengths of over 6 μm, and the abundance of mitochondria are interpreted as signs that the mite is slow moving, but capable of considerable and sustained contraction forces, features deemed necessary in the strong currents of the frigid water prevailing in the mite's habitat. Presence and distribution of regulatory (troponin, tropomyosin, caldesmon and calponin), contractile (actin, myosin, paramyosin and miniparamyosin) and structural (alpha-actinin, titin, minititin and nebulin) proteins were determined immunocytochemically. The results are consistent with the notion of a well-functioning contractile machinery but, furthermore, provide evidence for the great importance of the structural proteins alpha-actinin, minititin and nebulin in maintaining muscle-cell stability under the environmental conditions in which the mite has to function.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    ISSN: 1432-0568
    Schlagwort(e): Spermatogonia ; Spermatogenesis ; Spermiogenesis ; Human testis ; Cycle of the human seminiferous epithelium
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The numbers of each different cell type in the human seminiferous epithelium were determined throughout the 6 stages of the cycle in both semithin and ultrathin sections obtained from 15 young adult men with normal testicular histology. Up to 4 types of A spermatogonia (Ad, Ap, Al and Ac) were distinguished. In addition, the DNA nuclear content of seminiferous epithelium cells was determined on Feulgen-stained sections. Both Ad and Ap spermatogonia showed a 2c DNA content and were present in the 6 stages of the cycle, though their numbers decreased in stages III–V. Both Al and Ac spermatogonia showed a DNA content varying from 2c to 4c. Al spermatogonia were observed in stages III–V; their numbers plus those of Ad spermatogonia in these stages were similar to the numbers of Ad spermatogonia in the other stages lacking in Al spermatogonia. Ac spermatogonia appeared in stages III–VI and their numbers plus those of Ap spermatogonia in stages III–V were similar to the numbers of Ap spermatogonia in the other stages lacking in Ac spermatogonia. The results suggest that Ad spermatogonia are the stem cells. Some of them replicate their DNA; during this replication they appeared as Al spermatogonia. Al spermatogonia divide, giving rise to both Ad and Ap spermatogonia. Some Ap spermatogonia replicate their DNA; during this process they are transformed into Ac spermatogonia which divide, giving rise to B spermatogonia.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 4
    ISSN: 1432-0568
    Schlagwort(e): Leydig cell ; Cycle of the human seminiferous epithelium ; Human testis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In order to evaluate the occurrence of a Leydig cell cycle related to the cycle of the seminiferous epithelium in man, the numbers of peritubular Leydig cells and surface area of these cells along 1 mm of tubular basement membrane at each stage of the cycle were calculated on histological sections of young adult testes. The Leydig cells that were located separated from the tubules (perivascular Leydig cells) were also classified according to the stage of the cycle shown by the nearest seminiferous tubule; the surface area and number of these cells were also calculated. The total surface area and numbers of Leydig cells (peritubular plus perivascular) along 1 mm of tubular basement membrane did not change during the cycle of the seminiferous epithelium. Both the surface area and the numbers of peritubular Leydig cells were greater in stages I and II of the cycle, when spermatozoa are released; they decreased in stages III and IV and increased again in stages V and VI, whereas the contrary occurred in perivascular Leydig cells. The average surface area of each Leydig cell type remained constant throughout the stages of the cycle.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 5
    ISSN: 1432-0568
    Schlagwort(e): Spermatogenesis ; Spermatogonia ; Spermatocytes ; Spermatids ; Sertoli cells ; Human testis ; Nucleolus ; Annulate lamellae ; Chromatoid body ; Nuage
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The ultrastructural study of nucleoli and ribonucleoprotein-containing structures in human seminiferous tubules revealed that the nucleoli of spermatogonia, spermatocytes and Sertoli cells exhibited a tripartite structure consisting of: (1) a fibrillar center, (2) a compact granular portion, and (3) a reticular portion containing both pars fibrosa and pars granulosa. The nucleoli of primary spermatocytes showed a developed reticular portion. At pachytene, the compact granular portion enlarged and lost its connection with the fibrillar center and the reticular portion which decreased in size. This suggests a nucleolar segregation similar to that of ovocytes in many species. Two similar developmental stages of nucleoli were observed in spermatogonia. In addition to nucleoli, there were other ribonucleoprotein-containing structures such as intranuclear closely-packed granules in Ap spermatogonia, coarse granules in the chromatin rarefaction zone of Ad spermatogonia, the nuage and Lubarsch crystals of spermatogonia, the chromatoid body of spermatids, the annulate lamellae of both spermatids and Sertoli cells, and many structures of the spermatid neck region.
    Materialart: Digitale Medien
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  • 6
    Digitale Medien
    Digitale Medien
    Springer
    Virchows Archiv 377 (1977), S. 79-84 
    ISSN: 1432-2307
    Schlagwort(e): Lymphangiectasis ; Testis ; Cryptorchidism ; Lymphatic vessels
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Testicular lymphangiectasis are described for the first time in a patient with bilateral inguinal cryptorchidism. A great number of irregular lymphatic channels was observed within the parenchyma and the tunica vasculosa in both testes. Large and numerous anastomosis between the lymphatic vessels of these two areas could also be seen. The MTD and the TFI of the left testis were normal. Both parameters were very low in the right testis. The association of this fact with the greater development of the lymphatic vessels in this testis strongly supports the idea that testicular lymphangiectasis interfere mechanically with the testis tubular development.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 7
    ISSN: 1432-0878
    Schlagwort(e): Leydig cell ; Prepubertal testis ; Testosteronecontaining cells ; Human
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Human testicular specimens were obtained from biopsies and autopsies covering the period from birth to adulthood. The number of testosterone-containing Leydig cells was determined using the peroxidase-anti-peroxidase method. This number decreased markedly from 3–6 months of age to the end of the first year of life and, up to 6 years of age, only a small number of testosterone-containing cells was found. From 6 years onwards the number of Leydig cells progressively increased. Ultrastructural examination revealed four types of Leydig cells: (1) fetal-type Leydig cells (from birth to 1 year of age) with round nuclei, abundant smooth endoplasmic reticulum and mitochondria with tubular cristae; (2) infantile-type Leydig cells (from birth to 8–10 years of age), showing a multilobated nucleus, moderately abundant smooth endoplasmic reticulum, some lipid droplets and mitochondria with parallel cristae; (3) prepubertal, partially differentiated Leydig cells (from 6 years of age onwards) with regularly-outlined round nuclei, abundant smooth endoplasmic reticulum, mitochondria with tubular cristae, and some lipid droplets and lipofuscin granules; and (4) mature adult Leydig cells (from 8–10 years of age onwards). The ultrastructure of the infantile-type Leydig cells and the lack of delay between the disappearance of the fetal-type Leydig cells and the appearance of infantile-type Leydig cells suggest that fetal-type Leydig cells give rise to the infantile-type Leydig cells. Before puberty, myofibroblast-like precursor cells differentiate into the prepubertal, partially differentiated Leydig cells, which complete their differentiation into the adult Leydig cells.
    Materialart: Digitale Medien
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  • 8
    Digitale Medien
    Digitale Medien
    Springer
    Cell & tissue research 185 (1977), S. 285-288 
    ISSN: 1432-0878
    Schlagwort(e): Striated muscle (mammalian) ; Myofilaments ; Actin filaments ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ultrastructural organization of myofilaments in skeletal muscle was studied in four mammalian species (mouse, rat, hamster, goat). In all these species, myofibrils showing irregularly distributed arrays of a variable number of actin filaments (from 6 to 11) were observed. The proportion of such myofibrils and the predominant patterns of actin filaments varied from one species to another. These results are in agreement with those previously reported for human skeletal muscle.
    Materialart: Digitale Medien
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  • 9
    ISSN: 1573-6865
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Dystrophin is a 427-kDa cytoskeletal protein, which occurs in scant amounts in vertebrate muscle and nerve cells. No previous references to dystrophin or associated proteins in invertebrates at the protein level have been found, while two recent studies investigated the presence of genes encoding proteins homologous to dystrophin in sea urchin and other invertebrates such as Drosophila melanogaster. In this study, the possible presence and distribution of dystrophin-like proteins were studied in different invertebrate muscle cell types and species through Western blot analysis and light and electron microscope immunohistochemistry using a panel of antibodies whose specificities have been determined in vertebrates. Crude protein extracts of leech Pontobdella muricata were analysed by Western blotting. The revealed protein band, with 140 kDa molecular weight, was related to dystrophin, utrophin or dystrophin-related protein-2 (DRP2) according to the specificities of the antibodies used to detect them. The immunofluorescence study showed positive immunoreactions in obliquely striated muscle of this hyrudinean. The immunoelectron microscopy study confirmed specific immunogold labelling beneath the sarcolemma of muscle cells. We thus assume that this protein is an invertebrate dystrophin-like product that is referred to as IDLp140. The potential functions of this invertebrate dystrophin-like protein in invertebrate muscles are discussed relative to previous data in vertebrate tissues.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 10
    ISSN: 1573-6865
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract The expression of E-, N- and P-cadherin, α-, β- and γ-catenin, and actin was studied by immunohistochemistry, ELISA, and Western blot analysis in normal prostates, and in the prostates of men with benign prostatic hyperplasia and men with prostatic carcinoma, in order to evaluate their possible role in the pathogenesis of these diseases. Present results reveal that the immunophenotype of hyperplastic prostates differs from those of both normal and carcinomatous prostates in the intracellular distribution (observed by immunohistochemistry) and the intensity (measured by ELISA) of immunoreactions to cadherins, catenins, and actin. Hyperplastic prostates differ form normal prostates in the weaker immunoreaction to the three cadherin types, the two catenins, and actin, as well as in the intracellular distribution of P-cadherin, β- and γ-catenin, and actin. Differences between benign prostatic hyperplasia and prostatic carcinoma are less marked because hyperplastic prostates differ from carcinomatous prostates only in the weaker immunoreactions to P-cadherin, and α-catenin. The most remarkable findings in this study were: (1) α-catenin production was elevated in prostatic carcinoma in comparison with benign prostatic hyperplasia and normal prostate; and (2) P-cadherin expression in benign prostatic hyperplasia is reduced with regard to those of normal and carcinomatous prostates. It may be concluded that a decreased immunoreaction to cadherins, catenins, and actin, as well as changes in the intracellular distribution of actin in prostatic cells are not necessarily suggestive of malignancy, because these alterations are also present in BPH, and thus, the loss of cadherin–catenin-mediated adhesion alone is not sufficient to establish an invasive phenotype.
    Materialart: Digitale Medien
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