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  • 1
    Electronic Resource
    Electronic Resource
    Muscle cells in the tiny marine Antarctic mite Halacarellus thomasi : an ultrastructural and immunocytochemical study (2000)
    Springer
    Polar biology 23 (2000), S. 759-765 
    Details
    ISSN: 1432-2056
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003000000149
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  • 2
    Electronic Resource
    Electronic Resource
    Intermediate filaments in the Sertoli cells of the ageing human testis (1997)
    Springer
    Virchows Archiv 431 (1997), S. 131-138 
    Details
    ISSN: 1432-2307
    Keywords: Key words Ageing men ; Ageing testes ; Intermediate filaments ; Vimentin ; Keratin ; Sertoli cell
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  The presence and distribution of intermediate filaments (vimentin, keratin, desmin) was studied in the Sertoli cells of elderly men by means of quantitative immunohistochemical methods. Sertoli cells from young men showed moderate immunogold labelling to vimentin throughout the entire cytoplasm between the cell organelles in tubules showing complete spermatogenesis. Immunogold particles were more numerous in the perinuclear cytoplasm and beneath the plasma membrane in all its faces. The testes from elderly men showed different tubule types; some showed complete spermatogenesis and a normal lamina propria, while others had spermatogenic arrest at different levels (spermatids, spermatocytes, spermatogonia). The immunohistochemical reaction to vimentin in the Sertoli cells of tubules with complete spermatogenesis (type a) was similar to that in the cells of young men. In the Sertoli cells of severely damaged tubules (type b) the immunohistochemical reaction was more intense and immunogold particles extended in similar proportions throughout the whole cytoplasm. When immunolabelling intensity was compared between the three groups of tubules, by counting the number of immunogold particles per square micrometre of cytoplasm, it was found to be significantly higher (P≤0.05) in type b tubules of elderly men than either in tubules of young men or in type a tubules of elderly men. Since the average cell surface of Sertoli cells was similar in all tubule types, these data suggest that an actual vimentin increase occurs in Sertoli cells of germ-cell-depleted tubules. Sertoli cell immunogold labelling to keratin was found neither in young men nor in type a tubules of ageing men, whereas a positive immunohistochemical reaction was observed in the Sertoli cells of type b tubules of elderly men. Immunogold particles were localized mainly in the perinuclear cytoplasm, and beneath the lateral and basal cell surfaces. The observation of vimentin increase and keratin re-expression in ageing Sertoli cells only in germ-cell-depleted tubules suggests that the changes in intermediate filaments are related to the local factors associated with completion of spermatogenesis, causing functional changes in Sertoli cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004280050079
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  • 3
    Electronic Resource
    Electronic Resource
    Changes in surface area and number of Leydig cells in relation to the 6 stages of the cycle of the human seminiferous epithelium (1988)
    Springer
    Anatomy and embryology 178 (1988), S. 423-427 
    Details
    ISSN: 1432-0568
    Keywords: Leydig cell ; Cycle of the human seminiferous epithelium ; Human testis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00306048
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  • 4
    Electronic Resource
    Electronic Resource
    Immunocytochemical and quantitative study of the tunica albuginea testis in young and ageing men (1997)
    Springer
    Histochemistry and cell biology 107 (1997), S. 469-477 
    Details
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  A light and electron microscope immunohistochemical study of the tunica albuginea from both young and elderly men was carried out to determine the distribution of the cells that contain actin, vimentin and/or desmin, and to evaluate the possible variations with ageing by means of quantitative studies. Testicular volume and testicular parenchyma volume decreased significantly with age whereas the tunica albuginea volume remained unchanged. These results agree with the scanty quantitative changes observed in the testicular connective tissue with age, and the notion that age-related changes in testicular volume are principally restricted to the seminiferous tubules. Three connective tissue layers could be distinguished in the tunica albuginea in both young and elderly men. The middle and inner layers increased in width with age while the width of the outer layer decreased. The average width of the tunica albuginea increased significantly with ageing. The tunica albuginea of young men and elderly men presented two types of fusiform cells: (1) fibroblast-like cells, which immunoreacted to actin and vimentin, but not to desmin; and (2) myoid cells, which immunoreacted to actin, vimentin and desmin. In both young men and elderly men, the total number of desmin-positive cells (myoid cells) was significantly lower than that of fibroblasts. However, the total number of desmin-positive cells was significantly increased in ageing men. In young testes, desmin-positive cells were more abundant in the outer layer of the tunica albuginea, whereas in elderly men these cells predominated in the middle layer. The increased desmin immunoexpression in the tunica albuginea of ageing men contrasts with the decrease in desmin immunoreaction in other myoid cells of the testis, the peritubular myoid cells, but only in seminiferous tubules that showed severe germ cell depletion. This suggests that changes in intermediate filament immunoexpression in peritubular cells are focalised, and thus, under local control, whereas changes in the tunica albuginea cells are generalised and possibly related to factors also affecting the connective tissue in other organs
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004180050134
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  • 5
    Electronic Resource
    Electronic Resource
    Immunocytochemical electron microscopic study and Western blot analysis of myosin, paramyosin and miniparamyosin in the striated muscle of the fruit fly Drosophila melanogaster and in obliquely striated and smooth muscles of the earthworm Eisenia foetida (1997)
    Springer
    Journal of muscle research and cell motility 18 (1997), S. 169-177 
    Details
    ISSN: 1573-2657
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Miniparamyosin is a paramyosin isoform (55--60 kDa) that has been isolated in insects (Drosophila) and immunolocalized in several species of arthropods, molluscs, annelids and nematodes. In this study, the presence and distribution of this protein, in comparison with that of paramyosin and myosin, has been examined in the striated muscle (tergal depressor of trochanter) of Drosophila melanogaster, and the obliquely striated muscle (body wall) and the smooth muscle (outer layer of the pseudoheart) of the earthworm Eisenia foetida by means of immunocytochemical electron microscopic study and Western blot analysis miniparamyosin, paramyosin and myosin antibodies from Drosophila. In the striated muscle of D. melanogaster, the three proteins were immunolocalized along the length of the thick filaments (A- bands). The distribution of immunogold particles along these filaments was uniform. The relative proportions miniparamyosin/paramyosin/myosin (calculated by counting the number of immunogold particles) were: 1/10/68. In the obliquely striated muscle of E. foetida, immunoreactions to the three proteins were also found in the thick filaments, and the relative proportions miniparamyosin/paramyosin/myosin were 1/2.4/6.9. However, whereas the distribution of both myosin and miniparamyosin along the thick filament length was uniform, paramyosin immunolabelling was more abundant in the extremes of thick filaments (the outer zones of A-bands in the obliquely striated muscle), where the thick filaments become thinner than in the centre (the central zone of A-bands), where these filaments are thicker. The relative proportions of paramyosin in the outer and of paramyosin in the central zones of A-bands were 4/1. This irregular distribution of paramyosin along the thick filament length might be actual but it may also be explained by the fusiform shape of thick filaments in the earthworm: assuming that paramyosin is covered by myosin, paramyosin antigens would be more exposed in the tips than in the centre of thick filaments. If miniparamyosin is, in turn, covered by paramyosin, the exposure of miniparamyosin antigens would be low even in the tips of thick filaments, and this might explain the scanty immunoreaction observed for this protein and the absence of a higher number of immunogold particles in the extremes of thick filaments. The distribution of the three proteins in the earthworm smooth muscle was as in the obliquely striated muscle, although the proportions miniparamyosin/paramyosin/myosin were 1/1.5/5.2; this is, immunoreactions to paramyosin and miniparamyosin were lower than in the obliquely striated muscle
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018657722595
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  • 6
    Electronic Resource
    Electronic Resource
    α-actinin in different invertebrate muscle cell types of Drosophila melanogaster, the earthworm Eisenia foetida, and the snail Helix aspersa (1999)
    Springer
    Journal of muscle research and cell motility 20 (1999), S. 1-9 
    Details
    ISSN: 1573-2657
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The presence and distribution of α-actinin has been studied in several invertebrate muscle cell types. These comprised transversely striated muscle (flight muscle) from the fruit fly Drosophila melanogaster, transversely striated muscle (heart muscle) from the snail Helix aspersa, obliquely striated muscle (body wall muscle) from the earthworm Eisenia foetida, smooth muscle (retractor muscle) from H. aspersa, and smooth muscle (outer muscular layer of the pseudoheart) from E. foetida. The study was carried by means of Western blot analysis, ELISA, and immunohistochemical electron microscopy, using anti α-actinin antibody. Immunoreaction for a protein with the same molecular weight as that of mammalian α- actinin was detected in all muscle types studied, although the amount and intensity of immunoreaction varied among them. In the insect muscle, immunolabelling was found along the whole Z-line. In both the transversely striated muscle from the snail and the obliquely striated muscle from the earthworm, immunolabelling did not occupy the whole Z-line but showed discontinuous, orderly arranged patches along the Z-line course. In the two smooth muscles studied (snail and earthworm), immunolabelling was limited to small patches which did not show an apparently ordered distribution. Since it is assumed that α-actinin is located at the anchorage sites for actin filaments, present observations suggest that, only in the Drosophila muscle, actin filaments areparallely arranged in all their course, whereas in the other invertebrate muscles studied these filaments converge on discontinuously distributed anchorage sites.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005455931815
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  • 7
    Electronic Resource
    Electronic Resource
    Effect of photoperiod on testicular function in blinded and non-blinded marbled newts, Triturus marmoratus (caudata, salamandridae) (1989)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 200 (1989), S. 151-162 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Adult male marbled newts (Triturus marmoratus) were collected at the beginning of the spermatogenetic period and exposed to different photoperiods (natural photoperiod with progressively increasing daylengths, total darkness, 8L:16D, 12L:12D, 16L:8D, and continuous light) for 3 months at 20°C. To evaluate the effect of photoperiodic input via pineal gland photoreceptors, two additional groups of newts were blinded by a non-aggressive method (an elastic rubber cap was adjusted to the head to cover the eyes but not the pineal photoreceptors). These animals were exposed either to the natural photoperiod or to 12 hr of light per day. Quantitative histologic studies on testicular development and germ-cell volume revealed no significant differences between non-blinded and blinded animals. Testicular size and germ-cell development increased in the following order: total darkness, constant light, 8L:12D, natural photoperiod, 12L:12D, and 16L:8D. These results suggest that (1) long photoperiods enhance testicular development, whereas short photoperiods or an environment of continuous light have the opposite effects and (2) the effect of photoperiods on testicular function in newts is independent of the ocular photoreceptors.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1052000205
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  • 8
    Electronic Resource
    Electronic Resource
    Ultrastructurally different muscle cell types in Eisenia foetida (Annelida, Oligochaeta) (1995)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 224 (1995), S. 87-96 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Muscles in the body wall, intestinal wall, and contractile hemolymphatic vessels (pseudohearts) of an oligochaete anelid (Eisenia foetida) were studied by electron microscopy. The muscle cells in all locations, except for the outer layer of the pseudohearts, are variants of obliquely striated muscle cells. Cells comprising the circular layer of the body wall possess single, peripherally located myofibrils that occupy most of the cytoplasm and surround other cytoplasmic organelles. The nuclei of the cells lie peripherally to the myofibrils. The sarcomeres consist of thin and thick myofilaments that are arranged in parallel arrays. In one plane of view, the filaments appear to be oriented obliquely to Z bands. Thin myofilaments measure 5-6 nm in diameter. Thick myofilaments are fusiform in shape and their width decreases from their centers (40-45 nm) to their tips (23-25 nm). The thin/thick filament ratio in the A bands is 10. The Z bands consist of Z bars alternating with tubules of the sarcoplasmic reticulum. Subsarcolemmal electron-dense plaques are found frequently. The cells forming the longitudinal layer of the body wall musculature are smaller than the cells in the circular layer and their thick filaments are smaller (31-33 nm centrally and 21-23 nm at the tips). Subsarcolemmal plaques are less numerous. The cells forming the heart wall inner layer, the large hemolymphatic vessels, and the intestinal wall are characterized by their large thick myofilaments (50-52 nm centrally and 27-28 nm at the tips) and abundance of mitochondria. The cells forming the outer muscular layer of the pseudohearts are smooth muscle cells. These cells are richer in thick filaments than vertebrate smooth muscle cells. They differ from obliquely striated muscle cells by possessing irregularly distributed electron-dense bodies for filament anchorage rather than sarcomeres and Z bands and by displaying tubules of smooth endoplasmic reticulum among the bundles of myofilaments. © 1995 Wiley-Liss, Inc.
    Additional Material: 21 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1052240110
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  • 9
    Electronic Resource
    Electronic Resource
    E-, N- And P-cadherin, and α-, β- and γ-catenin Protein Expression in Normal, Hyperplastic and Carcinomatous Human Prostate (2000)
    Springer
    Journal of molecular histology 32 (2000), S. 659-667 
    Details
    ISSN: 1573-6865
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004111331752
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  • 10
    Electronic Resource
    Electronic Resource
    A lectin histochemistry comparative study in human normal prostate, benign prostatic hyperplasia, and prostatic carcinoma (1999)
    Springer
    Glycoconjugate journal 16 (1999), S. 375-382 
    Details
    ISSN: 1573-4986
    Keywords: lectins ; Western blot ; normal prostate ; benign prostatic hyperplasia ; prostatic carcinoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The partial oligosaccharide sequences of glycoconjugates and the nature of their glycosidic linkages were investigated in normal human prostate, benign prostatic hyperplasia (BPH) and prostatic carcinoma by means of lectin histochemistry, using light microscopy and Western blot analysis. The labeling pattern of BPH differed from that of normal prostate in having more intense staining with DSA, HPA, UEA-I and AAA, and in showing lesser staining with WGA and SBA. Prostatic carcinoma differed from normal prostates in displaying the more intense labeling with PNA, DSA, SBA, DBA, UEA-I and AAA, and in having lesser labeling with WGA. The main differences in labeling pattern between prostatic carcinoma and BPH were that the latter specimens showed more marked staining with PNA, DSA, DBA, SBA, UEA-I and AAA, and lesser staining with WGA and HPA. The staining patterns of SNA, MAA, ConA, LCA and GNA were similar in all three groups of specimens. For most of the lectins studied, including those showing a similar immunohistochemical staining in the three groups of specimens studied, the Western blot analysis showed differences in the banding pattern among normal, hyperplastic, and carcinomatous prostates. Present results suggest that the glycosylation of proteins was modified in both BPH and prostatic carcinoma. In BPH a strong expression of N-acetylgalactosamine residues occurred, while in prostatic carcinoma an increase of sialic aci, galactose and fucose residues was observed. No changes in mannose residues were detected.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007012514118
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