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RT Temes WA Talbot YM Carrillo GM Keck JA Wernly 《Canadian Metallurgical Quarterly》1998,65(1):257-259
The patterns of macroscopic growth of 20 first generation human tumor xenografts (16 renal cell carcinomas and 4 squamous cell carcinomas of the head and neck region) were studied with the recursion formula of the Gompertz function. This method enables the characterization of each tumor growth pattern by two parameters: (i) parameter a, which correlates with the starting growth rate of the tumor and (ii) parameter b, which is a measure of the intensity of growth deceleration as a function of tumor growth. A statistically significant prediction of the establishment of a xeno-transplantation line after serial subpassaging (in 9/20 tumors) according to the characteristics of first passage growth curves (p<0. 01) is reported. Especially parameter b, the value of the growth deceleration, highly correlates with serial growth: tumors showing less growth deceleration (higher b-values) during first passage more frequently develop into transplantation lines. On the contrary line development could not be predicted on the basis of the a-values of the first passage growth curves alone (p=0.137). This observation adds to the accumulating evidence, that the process of tumor growth deceleration is a pivotal parameter of tumor biology. Moreover, the present evaluation substantially reduces the time needed to assay serial growth of tumor xenografts for prognostic purposes making this assay potentially more attractive for clinical use. 相似文献
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In this study, various commercially used antiglaucoma drugs and corticosteroids were investigated in their effects on porcine corneal endothelial cells especially in cellular glucose uptake. Cellular glucose uptake directly affects the pumping efficiency in corneal endothelial cells. Following the cells' treatment with various antiglaucoma eyedrops for 100 min, the 3H-2-deoxyglucose uptake in cultured porcine corneal endothelial cells was affected by betaxolol from 3.1% (1.6 mM), 181% (0.16 mM) to 158% (0.016 mM), by timolol from 93% (0.79 mM), 227% (0.079 mM) to 151% (0.0079 mM), by carteolol from 141% (3.4 mM), 180% (0.34 mM) to 97% (0.034 mM), by levobunolol from 80% (1.5 mM), 98% (0.15 mM) to 90% (0.015 mM), by dipivefrin from 116% (0.2 mM), 176% (0.02 mM) to 108% (0.002 mM) and by pilocarpine from 115% (9.6 mM), 210% (0.96 mM) to 210% (0.096 mM) when the cells were compared with a control medium. In the presence of various corticosteroids, the glucose uptake in corneal endothelial cells was affected by fluorometholone from 160% (0.26 mM), 139% (0.026 mM) to 107% (0.0026 mM), by dexamethasone from 85% (0.25 mM), 117% (0.025 mM) to 109% (0.0025 mM) and by betamethasone from 95% (0.25 mM), 96% (0.025 mM) to 99% (0.0025 mM). These results show that the commercial eyedrops of antiglaucoma drugs and corticosteroids will not decrease the cellular glucose uptake in cultured porcine corneal endothelial cells except when incubated with high concentrations of betaxolol, levobunolol and dexamethasone. 相似文献
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The effects of 1/1000 field recommended concentration of the organophosphorus compounds; edifenphos and glyphosate on the immune response and protein contents were investigated after different time intervals. The cell mediated immune response assessed by proliferative response of splenocytes to mitogens; phytohemagglutinin (PHA) and concanavalin A (Con A) for T cell and lipopolysaccharide (LPS) for B cell decreased significantly in tems of the level of stimulation index in the treated fish and reached maximal depression after 4 weeks. Humoral immunity assessed as splenic antibody plaque forming cells (PFC) measured after 5 days in vitro immunization to sheep erythrocytes (SRBC's) were suppressed in a concentration dependent pattern by the two compounds. The estimated ED50 for the PFC/10(6) cells of edifenphos and glyphosate were 1.48 x 10(-2) uM and 1.65 x 10(-2) uM respectively. The data also showed that serum antibody titres in the treated fish were decreased in a time dependent manner. The total protein content of serum treated with the two pesticides was decreased after different time periods compared with control. The blood serum of treated and untreated Tilapia nilotica were analyzed electrophoretically for protein components and the percentage of proteins in each fraction was determined. 相似文献
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YM Barri RA Davidson S Senler TC Flynn JM Seger TR Harward CS Wilcox 《Canadian Metallurgical Quarterly》1996,89(7):679-683
We analysed the outcome of 63 consecutive, adequate interventions for atherosclerotic renal artery stenosis and hypertension: 34 patients had percutaneous transluminal renal angioplasty, and 29 had surgical correction. Hypertension was cured in 21% of patients and improved in 47%, but 32% failed to respond. We analyzed clinical variables predictive of cure. Duration of hypertension, level of diastolic blood pressure, and sex were found to be predictive of cure. The highest probability of cure was found in men with a duration of hypertension of less than 10 years and an initial diastolic blood pressure of greater than 80 mm Hg. Use of these clinical variables in a tree-based model correctly classified 80% of cases, with a sensitivity of 92% and a specificity of 77%. We conclude that a tree-based clinical algorithm based on only three clinical criteria correctly predicted cure of hypertension in most patients with renal artery stenosis and may be useful in decision making. A prospective analysis will be required to evaluate the clinical validity of the algorithm. 相似文献
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This study was designed to evaluate the effect of chronic treatment with cilazapril on vascular reactivity of aorta and mesenteric artery from Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR). Cilazapril (5 mg/kg), an angiotensin converting enzyme inhibitor, was injected intraperitoneally twice a day for 4 weeks. Results demonstrated that acetylcholine (ACh)-induced relaxation in aorta and mesenteric artery from SHR was significantly less than that from WKY, cilazapril-treated WKY, and SHR. The impairment of ACh-induced relaxation in SHR was significantly reversed after cilazapril treatment and there were no significant differences among WKY, cilazapril-treated WKY, and SHR. Meanwhile, both N omega-nitro-L-arginine (LNNA; 10(-4) mol/L) and methylene blue (MB; 10(-5) mol/L) completely blocked the vasodilator response to ACh in aorta but only partly inhibited in mesenteric artery from WKY, cilazapril-treated WKY, and SHR. These LNNA- and MB-resistant vasodilator responses to ACh in mesenteric artery were only slightly inhibited by TEA (10(-3) mol/L) but not by indomethacin (5 x 10(-6) mol/L). These findings suggest that there may be an unidentified endothelium-dependent relaxing factor(s) (EDRF), which exists in the endothelium and may participate in the modulation of blood pressure in SHR. Results further demonstrate that the antihypertensive effect of cilazapril may be partly mediated by the reversing function of endothelium to release EDRF and LNNA-resistant, unidentified relaxing factor(s). 相似文献
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