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  • Cell & Developmental Biology  (51)
  • Ultrastructure  (10)
  • 11
    Digitale Medien
    Digitale Medien
    Suppression of syntheses of high molecular weight nonmuscle tropomyosins in macrophages (1995)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 31 (1995), S. 273-282 
    Details
    ISSN: 0886-1544
    Schlagwort(e): Peritoneal macrophages ; F-actin microfilament ; in situ hybridization ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: In mouse fibroblasts, at least five TM isoforms are identified and they can be grouped into the high (TM1, TM2, and TM3) and low molecular weight TM isoforms (TM4 and TM5). Suppression of one of the high molecular weight tropomyosin (TM) isoforms in nonmuscle cells is implicated to be one of the causes for disorganization of actin microfilament bundles and subsequent changes in cell motility and cell shape. In this study, we studied the expression of tropomyosin isoforms in macrophages that exhibit high motility and ability to change cell shape. Two-dimensional gel electrophoresis followed by Western blot analysis using polyclonal anti-TM antiserum revealed that the high molecular weight TM isoforms were lacking in both resident and activated mouse peritoneal macrophages. Analyses of newly synthesized TM isoforms, Northern blot analyses using isoform-specific cDNA probes, and immunostaining with monoclonal anti-TM antibody that recognizes only the high molecular weight TM isoforms also demonstrated that the syntheses of the high molecular weight TM isoforms (TM1, TM2, and TM3) were completely suppressed, whereas the low molecular weight TM isoforms (TM4 and TM5) were expressed in macrophages. These results indicate that macrophages intrinsically lack the high molecular weight TM isoforms. In order to obtain information about cellular localization of the low molecular weight TM isoforms in macrophages, they were immunostained with polyclonal anti-TM antiserum that recognizes both the high and low molecular weight TM isoforms. The results showed that the low molecular weight TM isoforms were co-localized with F-actin in punctate and short fibrous structures. In addition, we performed in situ hybridization analysis to examine localizations of the TM mRNAs in fibroblasts and macrophages. The results showed that TM mRNAs were localized throughout the cytoplasm. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970310404
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  • 12
    Digitale Medien
    Digitale Medien
    Differentiation potential in medulloblastomas and primitive gliomas (1994)
    Springer
    Medical molecular morphology 27 (1994), S. 1-7 
    Details
    ISSN: 1860-1499
    Schlagwort(e): Medulloblastoma ; Primitive glioma ; Differentiation ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract To increase our understanding of the differentiation potential and cytogenesis of embryonal tumors in the brain, 12 medulloblastomas and 10 primitive gliomas were studied by electron microscopy. Of the medulloblastomas, 6 cases were undifferentiated tumors that demonstrated fine processes similar to microspikes. The remaining 6 cases were poorly-differentiated tumors. Axon-like processes were seen in 4 of these cases, including one with dense core vesicles. Astroglial processes were seen in 4 cases. Of the primitive gliomas, there were 2 undifferentiated tumors and 8 poorly-differentiated tumors. Some of the undifferentiated tumor cells had broad cytoplasmic processes. Of the 8 poorly-differentiated gliomas, there were groupings of junctional complexes in 7, microvilli in 4 and bundles of intermediate filaments in 5. It is concluded that medulloblastomas have both neuronal and glial differentiation potentials and that primitive gliomas have only glial differentiation potential. The origin of medulloblastomas may be from the remnants of cell nests with a multipotential differentiation capacity, and the origin for primitive gliomas may be from remnants of glial precursor cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02348220
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  • 13
    Digitale Medien
    Digitale Medien
    The ultrastructures of atypical and anaplastic meningiomas (1995)
    Springer
    Medical molecular morphology 28 (1995), S. 111-117 
    Details
    ISSN: 1860-1499
    Schlagwort(e): Atypical meningioma ; Anaplastic meningioma ; Ultrastructure ; Brain invasion ; Recurrence
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract To clarify the cytologic features of atypical and anaplastic meningiomas, 11 tumors from 4 patients were examined by electron microscopy and compared to 10 classic meningiomas. Although all of the classic meningiomas had oval nuclei, many cytoplasmic organelles, typical regular interdigitation of cell processes, and many well-developed desmosomes with many intermediate filaments, atypical meningiomas showed irregularlyindented nuclei, poorly-developed interdigitation of irregular cell processes, and a decreased number of desmosomes. Anaplastic meningiomas were composed of immature cells with scant cytoplasm and poorly-developed cell processes. Mitoses were occasionally observed. The intercellular spaces were obvious, and immature desmosomes with small amounts of filaments were rarely found. A high recurrence rate and metastases can be predicted from the presence of loose contacts between tumor cells and frequent mitoses in atypical and anaplastic meningiomas.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02348028
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  • 14
    Digitale Medien
    Digitale Medien
    Lectin-gold cytochemistry of mucin oligosaccharide biosynthesis in golgi apparatus of airway secretory cells1Mucin-secreting cells in the surface epithelium of the hamster trachea do not have a goblet shape, and whether the mucin produced by these cells is to be classified as “mucous” or “serous” is not known. The term airway secretory cell is therefore tentatively used in this report of the hamster (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 221 (1988), S. 635-644 
    Details
    ISSN: 0003-276X
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Medizin
    Notizen: To elucidate the mechanism for the biosynthesis of O-linked mucin oligosaccharides, airway secretory cells of the hamster trachea were embedded in Lowicryl K4M resin, and section were examined by lectin-gold cytochemistry with special attention focused on the Golgi apparatus. The interrelations between the Golgi cisternae stained with five different lectins were determined by double-staining procedures using various combinations of lectins conjugated with 14-nm and 8-nm colloidal gold. Several cis cisternae were stained only with HPA (Helix pomatia aggulutinin specific for terminal α-N-acetylgalactosamine). The next medial cisternae were not stained with HPA. but reacted positively with two lectins, GSII (Griffonia simplicifolia agglutinin II specific for terminal α- or β-N-acetlyglucosamine) and RCAI (Ricinus communis agglutinin I specific for β-galactose). The transcisternae as well as condensing and mature secretory granules were labeled with four lectins, UEAI (Ulex europaeus aggulutinin I specific for terminal α-L-fucose) and LFA (Limax flavus aggulutinin specific for terminal N-acetyl or N-glycolyl neuraminic acid) in addition to HPA and RCAI. The same number of trans cisternae were positive to HPA and UEAI, whereas LFA bound to a few transmost cisternae but fewer than were stained with HPA or UEAI. The observed sequential appearance of different sugar residues in different levels of Golgi cisternae (from cis to trans cisternae) coincides quite well with the sugar sequence of airway mucin oligosaccharide (from reducing to nonreducing ends) proposed by biochemical analysis. It is suggested that airway mucin oligosaccharides elongate during a vectorial movement through the Golgi stack from cis toward trans and that the stack consists of at least three functionally distinct segments, cis, medial, and trans; in these three segments there take place, respectively, the initial O-glycosylation of mucin core peptide, the formation of a core region of oligosaccharide chain, and the completion of chain growth by addition of terminal sugar moieties.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/ar.1092210209
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  • 15
    Digitale Medien
    Digitale Medien
    Subperiosteal lmplantation of octacalcium phosphate (OCP) stimulates both chondrogenesis and osteogenesis in the tibia, but only osteogenesis in the parietal bone of a rat (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 242 (1995), S. 40-46 
    Details
    ISSN: 0003-276X
    Schlagwort(e): Octacalcium phosphate ; Implantation ; Long bone ; Calvarium ; Osteogenesis ; Chondrogenesis ; Type I collagen ; Type II collagen ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Medizin
    Notizen: Background: It is not known whether long bones and calvaria have distinct biological characteristics. Octacalcium phosphate (OCP), which is a precursor phase of the hydroxyapatite, has been reported to stimulate bone formation if implanted in the subperiosteal region of mouse calvaria. The present study was designed to investigate how the long bone and the calvarium respond to OCP implantation and to compare their biological characteristics.Methods: The synthetic OCP was implanted into the subperiosteal region of rat tibiae and parietal bones being mixed with bovine type I collagen treated by pepsin (Atelocollagen). The biological response was examined histologically and immunohistochemically for collagen matrix phenotypes of types I and II to identify bone and cartilage formation.Results: Both chondrogenesis and osteogenesis were initiated in the tibia 1 week after implantation of OCP and most of the cartilage was replaced by bone at week 2. However, the parietal bone did not show osteogenesis responding to OCP implantation until week 3, and no cartilage formation was associated with the osteogenesis.Conclusions: The present study demonstrated the distinct characteristics of biological response to OCP implantation between the long bone and the calvarium in terms of whether or not cartilage formation is involved in the stimulated osteogenesis by OCP, and in terms of timing of the stimulated chondrogenesis and/or osteogenesis, i.e., the parietal bone takes more time to respond to OCP implantation than the tibia. © 1995 Wiley-Liss, Inc.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/ar.1092420106
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  • 16
    Digitale Medien
    Digitale Medien
    Possible involvement of focal adhesion kinase, p125FAK, in osteoclastic bone resorption (1995)
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 58 (1995), S. 424-435 
    Details
    ISSN: 0730-2312
    Schlagwort(e): Key words ; osteoclast ; focal adhesion kinase ; tyrosine kinase ; tyrosine phosphorylation ; podosome ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Involvement of tyrosine phosphorylation in osteoclastic bone resorption was examined using osteoclast-like multinucleated cells prepared from co-cultures of mouse osteoblastic cells and bone marrow cells in the presence of 1α,25-dihydroxyvitamin D3. When osteoclast-like cells were plated on culture dishes in the presence of 10% fetal bovine serum, they were sharply stained in their peripheral region by anti-phosphotyrosine antibody. Western blot analysis revealed that 115-to 130-kD proteins were tyrosine-phosphorylated in osteoclast-like cells. Using immunoprecipitation and immunoblotting, one of the proteins with 115-130 kD was identified as focal adhesion kinase (p125FAK), a tyrosine kinase, which is localized in focal adhesions. Immunostaining with anti-p 125FAK antibody revealed that p125FAK was mainly localized at the periphery of osteoclast-like cells. Herbimycin A, a tyrosine kinase inhibitor, not only suppressed tyrosine phosphorylation of p125FAK but also changed the intracellular localization of p125FAK and disrupted a ringed structure of F-actin-containing podosomes in osteoclast-like cells. Antisense oligodeoxynucleotides to p125FAK inhibited dentine resorption by osteoclast-like cells, whereas sense oligodeoxynucleotides did not. These results suggest that p125FAK is involved in osteoclastic bone resorption and that tyrosine phosphorylation of p125FAK is critical for regulating osteoclast function.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jcb.240580405
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  • 17
    Digitale Medien
    Digitale Medien
    Calpain activation in shear-induced platelet aggregation (1997)
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 66 (1997), S. 54-64 
    Details
    ISSN: 0730-2312
    Schlagwort(e): calpain activation ; platelet ; proteolysis of talin ; shear stress ; shear-induced platelet aggregation (SIPA) ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Fluid shear stress has been known to activate platelet reaction such as aggregation, but the exact mechanism of shear-induced platelet aggregation (SIPA) has not been fully understood. Calpain, an intracellular calcium-activated cysteine protease, is abundant in platelets and is considered to be activated and involved in the proteolytic processes during platelet activation. A possible activation of calpain in SIPA was investigated, employing a newly developed aggregometer and specific monoclonal antibodies to detect activation of calpain. When a shear stress gradient varying between 6 and 108 dyn/cm2 was applied to platelets, activation of μ-calpain was observed only in high-shear-stressed platelets, resulting in the proteolysis of talin. At 1 min after the onset of constant high shear stress of 108 dyn/cm2, μ-calpain activation and proteolysis of talin were detected and increased in a time-dependent manner. Constant shear stress more than 50 dyn/cm2, applied for 5 min, caused μ-calpain activation and proteolysis of talin, which were increased in a shear-force-dependent manner. Calpeptin, a calpain-specific peptide antagonist, caused the complete inhibition of both μ-calpain activation and proteolysis of talin, while SIPA profiles with calpeptin showed almost no change compared to those without calpeptin. These results suggest the possibility of calpain involvement in late phases of shear-induced platelet activation such as cytoskeletal reorganization. J. Cell. Biochem. 66:54-64, 1997. © 1997 Wiley-Liss, Inc.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
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  • 18
    Digitale Medien
    Digitale Medien
    Inhibition of osteoblastic cell differentiation by conditioned medium derived from the human prostatic cancer cell line PC-3 in vitro (1997)
    New York, N.Y. : Wiley-Blackwell
    Journal of Cellular Biochemistry 67 (1997), S. 248-256 
    Details
    ISSN: 0730-2312
    Schlagwort(e): human prostatic cancer cell (PC-3) ; osteoblastic cell differentiation ; bone nodule formation ; alkaline phosphatase activity ; osteocalcin ; osteopontin ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Human prostatic carcinoma frequently metastasizes to bone tissue and activates bone metabolism, especially bone formation, at the site of metastasis. It has been reported that an extract of prostatic carcinoma and conditioned medium (CM) of a human prostatic carcinoma cell line, PC-3, established from a bone metastastic lesion, stimulate osteoblastic cell proliferation. However, there is little information about the effect of PC-3 CM on the differentiation of osteoblastic cells. In this study, we investigated the effect of PC-3 CM on the differentiation of two types of osteoblastic cells, primary fetal rat calvaria (RC) cells containing many undifferentiated osteoprogenitor cells, and ROS 17/2.8, a well-differentiated rat osteosarcoma cell line. PC-3 CM inhibited bone nodule formation and the activity of alkaline phosphatase (ALPase), an osteoblastic marker enzyme, on days 7, 14, and 21 (RC cells) or 3, 6, and 9 (ROS 17/2.8 cells) in a dose-dependent manner (5-30% CM). However, the CM did not affect cell proliferation or cell viability. PC-3 CM was found to markedly block the gene expression of ALPase and osteocalcin (OCN) mRNAs but had no effect on the mRNA expression of osteopontin (OPN), the latter two being noncollagenous proteins related to bone matrix mineralization. These findings suggest that PC-3 CM contains a factor that inhibits osteoblastic cell differentiation and that this factor may be involved in the process of bone metastasis from prostatic carcinoma. J. Cell. Biochem. 67:248-256, 1997. © 1997 Wiley-Liss, Inc.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
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  • 19
    Digitale Medien
    Digitale Medien
    Morphological studies on the synthesis of secretory granules in convoluted tubules of mouse submandibular gland (1975)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 183 (1975), S. 405-419 
    Details
    ISSN: 0003-276X
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Medizin
    Notizen: The synthesis of zymogen-like secretory granules in convoluted tubules of mouse submandibular gland (SMG) was investigated by histometry, light microscopy and electron microscopy. In normal males secretory granules in the SMG increased greatly from 25 days after birth and reached a maximum level 50 days after birth. Castration of adult male mice markedly decreased the level, but it was completely restored by testosterone administration. A parallel was found between change in the granule level and the amount of rough endoplasmic reticulum (RER) in the convoluted tubular cells during development or after various treatments. Development of the Golgi apparatus was also observed in the cells when the granules increased. Both the increase in the granules and in the RER induced by testosterone were prevented by actinomycin D or puromycin. These results indicate that the granule contents are synthesized on the RER under the control of testosterone, and then condensed in the Golgi apparatus.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/ar.1091830305
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  • 20
    Digitale Medien
    Digitale Medien
    Morphogenesis of the secondary palate in mouse embryos with special reference to the development of rugae (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 223 (1989), S. 299-310 
    Details
    ISSN: 0003-276X
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Medizin
    Notizen: Morphological studies of secondary palate formation, with special reference to the development of rugae, were carried out on Jcl:ICR mouse embryos. Three rugae were observed on the anterior part of the future oral surface of the vertically developing palatal shelves in 13-day embryos. Rugae increased in number as the development of the palatal shelves proceeded, and five to six prominent rugae were observed in 14-day embryos just prior to shelf elevation. The folding of these five to six rugae progressed in conjunction with the formation of a sharp, valley-like groove at the base of the anterior two-fifths of the vertical palatal shelves. As palatal shelves elevated, the groove disappeared gradually, and, accordingly, the folding of rugae loosened. In the groove region, the superficial epithelial cells were roundish, while the basal ones were elongated. Such characteristic features were no longer observed when the disappearance of the groove was completed. Eight rugae were observed on the future hard palate of 14-day embryos with already completed palatal fusion. An additional ruga was frequently found in 15-day embryos, and the pattern then was almost the same as that of an adult. Epithelial thickening and condensation at the rugae region, as well as mesenchymal condensation under the epithelium of the rugae, were confirmed in embryos both before and after elevation of the palatal shelves. There is a possibility that structural characteristics observed in the epithelial and mesenchymal cells of the rugae and groove regions may be related to palatal shelf elevation.
    Zusätzliches Material: 9 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/ar.1092230309
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