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  • 1
    Electronic Resource
    Electronic Resource
    Induction of smooth muscle cells in the fibrous capsule of human hepatocellular carcinoma but not in the septa of hepatic cirrhosis (1999)
    Springer
    Virchows Archiv 434 (1999), S. 413-422 
    Details
    ISSN: 1432-2307
    Keywords: Key words Myosin heavy chain isoforms ; Smooth muscle actin ; Capsule ; Hepatocellular carcinoma ; Liver cirrhosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  We examined the expression of smooth muscle cytoskeleton in spindle-shaped cells in the capsule of hepatocellular carcinoma (HCC) and the septa of liver cirrhosis (LC). Serial sections of livers resected from 11 patients were stained with monoclonal antibodies against vimentin, desmin, smooth muscle actin (1A4, HHF35, CGA7) and smooth muscle myosin heavy chain isoforms (SM1, SM2). Capsular spindle-shaped cells exhibited a cytoskeletal feature indicative of intermediately differentiated smooth muscle cells. Computer-assisted morphometry revealed that the proportions of 1A4-, HHF35-, CGA7- and SM1- positive areas to vimentin-positive area were 88.0±11.0%, 50.8±17.4%, 25.3±16.4% and 19.4±12.4% (n=11) in main tumours and 86.6±9.4%, 50.9±18.7%, 21.1±12.3% and 17.6±9.7% (n=12) in daughter tumours, indicating that spindle-shaped cells are heterogeneous in cytoskeletal expression. Septal spindle-shaped cells in LC lacked the cytoskeletal proteins specific to differentiated smooth muscle cells (CGA7, SM1, SM2 and desmin). Electron microscopically, capsular spindle-shaped cells contained more microfilaments and less rough endoplasmic reticulum than do septal cells. Intermediately differentiated smooth muscle cells are induced in the capsule of HCC but not in the septa of LC, suggesting a role for stromal interaction by tumour cells in the induction of smooth muscle cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004280050360
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  • 2
    Electronic Resource
    Electronic Resource
    Promotive action of acylated ascorbate on cellular DNA synthesis and growth at low doses in contrast to inhibitory action at high doses or upon combination with hyperthermia (1996)
    Springer
    Journal of cancer research and clinical oncology 122 (1996), S. 41-44 
    Details
    ISSN: 1432-1335
    Keywords: Ascorbate ; Hyperthermia ; DNA synthesis ; Cell growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Effects of 6-O-palmitoyl ascorbate (ascorbate) developed to increase the antitumour activity of ascorbic acid on DNA synthesis and proliferation of Ehrlich ascites tumour cells were investigated. Treatment of the cells with the acylated ascorbate at 25–50 μM for 1 h resulted in no effect on DNA synthesis, assayed by pulse incorporation of [3H]thymidine after a culture period of 20 h, but led to 49%–87% enhanced DNA synthesis after 4 days, suggesting that long-term culture is required for promotion by ascorbate to occur. At a dose as high as 75 μM acylated ascorbate, however, cellular DNA synthesis was 64% inhibited after 20 h and 99% after 4 days. The results suggest that acylated ascorbate exhibits a dual action on DNA synthesis: promotion at low doses and inhibition at high doses, both of which are potentiated in a time-dependent manner. In contrast to the above-mentioned results at 37°C, acylated ascorbate at 25–75 μM inhibited but did not promote DNA synthesis at 42°C whatever the culture period. Similar results were exhibited when proliferation of cells cultured for a long period was investigated. At 37°C, 50μM acylated ascorbate increased the number of the cells to 3.6 times the control values after 8 days and to 1.9 times after 11 days; in contrast, a 75-μM dose decreased the cell number considerably. Combination with hyperthermia (42°C) suppressed the increase and cell growth was completely inhibited at 75μM.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01203071
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  • 3
    Electronic Resource
    Electronic Resource
    Regulation of apoptosis of interleukin 2-dependent mouse T-cell line protein tyrosine phosphorylation and polyamines (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 165 (1995), S. 615-623 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: We examined the effect of inhibitors of tyrosine kinase and tyrosine phosphatase on DNA fragmentation, protein tyrosine phosphorylation, and polyamine metabolism in the murine T-cell line CTLL-2. When cells were exposed to herbimycin A, a specific inhibitor of tyrosine kinase (Uehara et al., 1989, Biochem. Biophs. Res. Commun., 163:803-809), in the presence of interleukin 2 (IL-2), DNA was degraded into oligonucleosomal fragments in a dose-dependent fashion. Genistein, another inhibitor of tyrosine kinase (Akiyama et al., 1987, J. Biol. Chem., 262:5592-5596), had similar effects. Exposure of CTLL-2 cells to vanadate, a tyrosine phosphatase inhibitor, blocked with the DNA fragmentation induced by herbimycin A. Tyrosine phosphorylation of 55 Kd protein was inhibited by herbimycin A, and the inhibition was reduced by vanadate. Ornithine decarboxylase (ODC) activity decreased rapidly after herbimycin A was added to CTLL-2 cell cultures, while vanadate increased ODC activity. The exogenous addition of putrescine or spermine, but not that of spermidine, attenuated herbimycin A-induced DNA fragmentation. These findings suggest that phosphorylation of tyrosine residues of 55 Kd protein prevents DNA fragmentation and that polyamines are involved in regulation of apoptosis. © 1995 Wiley-Liss Inc.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041650320
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  • 4
    Electronic Resource
    Electronic Resource
    Role of putrescine in interleukin 1β production in human histiocytic lymphoma cell line U937 (1991)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 147 (1991), S. 199-207 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Treatment with 12-O-tetradecanoyl-phorbol-13-acetate (TPA) and incubation with lipopolysaccharide (LPS) induces Interleukin 1β (IL-1β) production in the histiocytic lymphoma cell line U937. Here we investigated the effect of treatment with both TPA and 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3) on LPS-induced IL-1β production in U937 cells. To clarify the mechanism of IL-1β production, the possible role of polyamines in this process was examined. Combined treatment with TPA and 1,25(OH)2D3 for 72 h followed by incubation with LPS for 24 h caused synergistic induction of both IL-1β release and mRNA expression. On the other hand, TPA increased the numbers of vitamin D3 receptors, which may be one mechanism of this synergistic induction. Ornithine decarboxylase (ODC), a rate-limiting enzyme for polyamine biosynthesis, was also induced by these compounds biphasically: the first peak of ODC activity was observed at 4 h of the incubation with the two compounds and the second peak was at 4 h after the addition of LPS. To find whether these peaks were related to IL-1β production, DL-α-difluoromethylornithine (DFMO), a specific irreversible inhibitor of ODC, was added together with TPA and 1,25(OH)2D3. DFMO decreased the cellular levels of putrescine and spermidine and suppressed IL-1β release and IL-1β mRNA expression by 65%. Exogenous putrescine, but not spermidine, abrogated these kinds of inhibition. Similar results were obtained with DFMO and the polyamines during the differentiation of the cells up to the monocyte or macrophage stage. These results thus suggest that changes in either of these intracellular polyamines, especially putrescine, help to regulate the differentiation of U937 cells, resulting in partial control of the regulation of IL-1β production.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1041470203
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