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The dose-dependent effects of gamma-radiation on the leucocyte cultures L-41 has been investigated. Irradiation by the dose of 0.25 Gy stimulates the cell proliferation while that by the doses of 1.0 and 2.0 Gy inhibits this process. In this dose range the radiohormesis effects characterizing structural organization of the probed membranes have been also registered for fluorescence parameters. The zone of qualitative transition of response of the cell membranes to radiation is individual for various effects. The action of radiation in the doses of 0.25 and 0.50 Gy induces a decrease of ANS fluorescence intensity and a decrease of membrane protein immersion in the lipid bilayer of leukocyte membranes. The values of these parameters rise at the doses of 1.0 and 2.0 Gy that reflects different directions of structural changes in various membrane regions. The irradiation in the range of 0.25-1.0 Gy induces the increase of microviscosity in deep regions of membrane lipid matrix while at the dose 2.0 Gy it causes its decrease. Radioactive radiation does not change the membrane protein conformation of leukocytes and polarity of lipid bilayer hydrophobic zones as recorded by fluorescent methods used. 相似文献
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AV Pridatkevich LN Saltykova AT Diduk OI Berezovskii 《Canadian Metallurgical Quarterly》1976,99(3):49-50
An investigation of the possible significance of 'stress' as a factor in the retention of bovine fetal membranes has been carried out, together with the investigation as to the possible variation of progesterone levels at parturition, as a cause of retention. No evidence of abnormal progesterone levels has been established, but from the evidence it is concluded that retention may well be yet another example of production disease. 相似文献
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L Faulkner OI Aruoma PM Brickell MJ Davies B Halliwell N Woolf DR Katz 《Canadian Metallurgical Quarterly》1993,99(1):1-13
We examined physiological events in the hyperplastic artery, using a method based on the mechanical responsiveness and myosin light-chain phosphorylation in response to various stimulants. Six weeks after endothelial denudation by ballooning of the right carotid artery, strips of this artery with moderate intimal hyperplasia (intimal area was 30-50% of medial area in 20 of 28 rabbits) were used for experiments. Strips from the left carotid served as the normal control. When the hyperplastic artery was stimulated with 30 microM PGF2 alpha, the maximal tension (232.4 +/- 49.1 mg/mg dry wt, mean +/- SD) was significantly higher (P < 0.05) than that of the control (129.5 +/- 16.4 mg/mg). The maximal extent of myosin light-chain monophosphorylation (45.4 +/- 8.9%) and diphosphorylation (10.9 +/- 5.2%) in the hyperplastic artery was significantly higher (P < 0.05) than that in the control artery (33.0 +/- 4.8 and 4.0 +/- 4.8%, respectively). The monophosphorylation of the myosin light chain in the hyperplastic artery was sustained for up to 20 min, while that in the control artery decreased to the basal level within 20 min. Similar observations were obtained by stimulation with 60 mM K+ or 30 microM norepinephrine. Dose-response curves of the development of tension in the hyperplastic artery to various agonists (K+, PGF2 alpha, norepinephrine) shifted upward the curves for the control artery. These results suggest that qualitative changes in the characteristics of smooth muscle cells may occur in the intimal hyperplastic portion, including a hyperreactive contraction associated with enhanced and sustained phosphorylation of the myosin light chain. 相似文献
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OI Muraina R Tank C Dhingra JC Vuletin F Colella G Abdelsayed BR Pachter L Honikman 《Canadian Metallurgical Quarterly》1996,91(4):792-794
Extrapulmonary small cell carcinoma has been reported from multiple sites, including the gallbladder. Small cell carcinoma of the gallbladder is a very rare tumor, found usually in elderly women and associated with cholelithiasis. It carries a grave prognosis, metastasizing early and causing death shortly after diagnosis. Treatment of metastatic disease with two different chemotherapeutic regimens has been shown to improve survival. To the best of our knowledge, this tumor has not been previously reported in a black individual, or in any subject less than 49 yr or more than 79 yr old. We report two cases: one is the first black and youngest reported case. The second is the oldest person reported with this rare malignancy. Radiological studies such as ultrasound and CT scan were useful in evaluating tumor spread and follow-up. 相似文献
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