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991.
LT Van der Ven SC Van Buul-Offers T Gloudemans PJ Roholl JS Sussenbach W Den Otter 《Canadian Metallurgical Quarterly》1997,75(8):1091-1097
Glioma tumour growth is associated with the expression of insulin-like growth factors I and II (IGFs) and of both type I and type II IGF receptors. It has also been shown that IGFs can stimulate proliferation of cultured glioma cells. We previously reported that histamine too can stimulate the growth of glioma cells in vitro. In this report, we study whether the histamine-induced growth of G47 glioma cells is mediated by the IGFs. We found that histamine stimulates the expression of both IGF-I and IGF-II mRNAs, as determined by a semiquantitative in situ hybridization analysis. Furthermore, incubation of G47 cells with histamine also induced cellular immunostaining for IGF-II. It could be shown that IGF-I-stimulated proliferation is inhibited by IGFBP-3, which decreases the availability of IGFs for binding to the IGF receptors, and by beta-galactosidase, which may decrease IGF binding to the type II IGF receptor, but is not inhibited by the anti-type I IGF receptor monoclonal antibody alphaIR3. However, neither IGFBP-3 nor beta-galactosidase nor alphaIR3 inhibited the histamine-induced proliferation. These results show that the growth-stimulatory effect of histamine is accompanied by the induction of IGFs. This histamine-induced growth stimulation is not mediated by activation of cell surface IGF receptors, although intracrine activation of type II IGF receptors may be involved. 相似文献
992.
KP Cockerham C Pal B Jani A Wolter JS Kennerdell 《Canadian Metallurgical Quarterly》1997,104(6):914-917
Experiments are carried out on 3400 mice, irradiated in dose 8 Gy (LD97/30). beta-Ketoanalogs of adrenaline (adrenalone, 50-150 mumol/kg), m,p-dipivaloyladrenaline (20 mumol/kg) and phenylephrine (but at 2070 mumol/kg) have the high radioprotective effect (survival is 60-100%), beta-ketoanalogs of isoprenaline and m-benzoylphenylephrine have the middle RPE (50-60%). Their effective doses (except dipivaloyladrenalone) are considerably bigger (in 9-76 times), than beta-hydroxysubstances doses, but the toxicity of benzoylphenylephrone, dipivaloyladrenalone and especially adrenalone is by far lower (consequently in 3, 8, 2, 7 and 136 times). Therapeutic indexes of beta-ketosubstances achieve 35-100. 相似文献
993.
JS Oghalai JR Holt T Nakagawa TM Jung NJ Coker HA Jenkins RA Eatock WE Brownell 《Canadian Metallurgical Quarterly》1998,79(4):2235-2239
The upright posture and rich vocalizations of primates place demands on their senses of balance and hearing that differ from those of other animals. There is a wealth of behavioral, psychophysical, and CNS measures characterizing these senses in primates, but no prior recordings from their inner ear sensory receptor cells. We harvested human hair cells from patients undergoing surgical removal of life-threatening brain stem tumors and measured their ionic currents and electromotile responses. The hair cells were either isolated or left in situ in their sensory epithelium and investigated using the tight-seal, whole cell technique. We recorded from both type I and type II vestibular hair cells under voltage clamp and found four voltage-dependent currents, each of which has been reported in hair cells of other animals. Cochlear outer hair cells demonstrated electromotility in response to voltage steps like that seen in rodent animal models. Our results reveal many qualitative similarities to hair cells obtained from other animals and justify continued investigations to explore quantitative differences that may be associated with normal or pathological human sensation. 相似文献
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996.
S Lee SY Chong JW Lee SC Kim YH Min JS Hahn YW Ko 《Canadian Metallurgical Quarterly》1997,20(10):883-888
Acute graft-versus-host disease (aGVHD) remains a major barrier to a wider application of allogeneic bone marrow transplantation (BMT). Although this complication is mainly dependent on donor-derived T lymphocytes, very little information is available concerning the mechanism of lethality. In this study, we investigated both the expression of Fas/Fas-ligand (FasL) and lymphocyte subset reconstitution in patients who underwent HLA-matched related allogeneic BMT (n = 16) and normal donors (n = 10), and several distinct features were observed. First, the reconstitutions of CD3+ and CD56+ cells were different between the aGVHD+ and aGVHD- group. In particular, the percentage of CD3-CD56+ cells was significantly decreased in patients with aGVHD (P < 0.01). Second, the expansion of CD8+ (P = 0.01) and CD8+ CD28- T cells (P = 0.03) was a characteristic finding in patients with aGVHD. Finally, we found that the percentages of Fas+CD8+, Fas+HLA-DR+ and FasL+ CD8+ cells were significantly increased. Fas antigen was highly coexpressed on most of the lymphocyte subsets, especially on CD8+ cells (P < 0.01), and also, significantly higher coexpression of FasL on CD8+ cells was found in patients with aGVHD (P < 0.01). In summary, an increase in the percentage of CD8+ cells which express Fas and its ligand in patients with aGVHD after BMT points to a possible role for the Fas/FasL pathway in the effector phase of aGVHD. 相似文献
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JS Harding EF Benfield PV Bolstad GS Helfman EB Jones 《Canadian Metallurgical Quarterly》1998,95(25):14843-14847
The influence of past land use on the present-day diversity of stream invertebrates and fish was investigated by comparing watersheds with different land-use history. Whole watershed land use in the 1950s was the best predictor of present-day diversity, whereas riparian land use and watershed land use in the 1990s were comparatively poor indicators. Our findings indicate that past land-use activity, particularly agriculture, may result in long-term modifications to and reductions in aquatic diversity, regardless of reforestation of riparian zones. Preservation of habitat fragments may not be sufficient to maintain natural diversity in streams, and maintenance of such biodiversity may require conservation of much or all of the watershed. 相似文献
1000.