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991.
992.
目的:通过检测居民厨房内烹调烟雾冷凝物对人外周血淋巴细胞的毒性作用,为全面评价烹调烟雾对健康的危害提供依据。方法:应用MTT法检测以菜油为食用油的烹调烟雾冷凝物对人外周血淋巴细胞的毒性作用。结果:不同浓度烹调烟雾冷凝物受试组间的OD值存在显著性差异(P<0.0001);各受试浓度组与DMSO对照组进行比较,受试浓度在125μg·ml1以上时,各受试组与DMSO对照组的OD值都存在显著性差异,而且各浓度组与对照组的OD值之差随测试浓度的升高而递增。结论:烹调烟雾冷凝物对人外周血淋巴细胞具有一定的毒性作用,并且存在剂量-反应关系。 相似文献
993.
A dynamic food chain model has been built for the modeling of the transfer of 137Cs in three types of vegetables consumed in Hong Kong, namely, white flowering cabbage (Brassica chinensis), head lettuce (Lactuca sativa) and celery (Apium graveolens). Some parameters have been estimated from the experimental data obtained in this work. The experimental data include the transfer factors of 137Cs from soil to the different vegetable species which are determined through high resolution gamma spectrometry, maximum crop biomasses for the vegetable species, the dry-to-fresh ratios for the vegetable species, the bulk density of soil layers and the average concentration of 137Cs in air. The derived parameters include the deposition rate and the root uptake rate, information for tillage, the logistic growth model and radionuclide concentrations in vegetables. The dynamic food chain model is solved by the Birchall–James algorithm to give the 137Cs concentration in subsurface soil, from the 0.1–25 cm soil layer, and the 137Cs concentration in harvested and unwashed vegetables. As validation of the model and parameters, the concentrations obtained experimentally and from the model are compared and are found to be in good agreement. 相似文献
994.
应用组织化学方法对百日咳菌液所致大鼠急性感染性脑水肿脑组织内乳酸脱氢酶、琥珀酸脱氢酶、单胺氧化酶的活性进行研究,结果显示:注菌组与正常对照组比较,三种氧化还原酶在脑组织内均出现多个局灶性酶活性减弱区,内毒素预处理组比注菌组酶活性强,提示急性感染性脑水肿时,脑组织内三种氧化还原酶活性均减弱,内毒素预处理对脑水肿有保护作用。 相似文献
995.
灰毡毛忍冬化学成分的研究 总被引:28,自引:0,他引:28
从灰毡毛忍冬(Lonicera mocranthoide Hand. -Mazz.)花的乙醇提取物的正丁醇溶解部分分得三个常春藤皂甙元的双糖链甙,其中一个为已知化合物川续断皂甙乙(dipsacoside B,Ⅰ);另外两个为新化合物,分别命名为灰毡毛忍冬皂甙甲(macranthoidin A,Ⅱ)和灰毡毛忍冬皂甙(nmcranthoidin B,Ⅲ),两者的次级皂甙灰毡毛忍冬次皂甙甲(macranthoside A,Ⅱb)和灰毡毛忍冬次皂甙乙(macranthoside B,Ⅲb),亦未见报道。 相似文献
996.
Lingling Huang Xian-lin Mao Zhu-zhong Shi Hui-die Cheng T.F. Su 《Nutrition Research》1984,4(6):977-980
Eleven healthy women, who were 25–35 years of age, primipara, fullterm and had had normal delivery, were included in this study. Breast milk was estimated for protein, non-protein nitrogen, lipids, lactose, sIgA, IgM, IgG and total and differential cell counts. In the first 3–5 days post-partum, protein concentration (chiefly immunoglobulins sIgA, IgM, IgG) was very high but decreased rapidly by day 5 and remained rather stable afterwards. The contents of fat and lactose were low in the first few days and increased gradually later. Neutrophils, lymphocytes, colostral cells and macrophages were all found in the breast milk. 相似文献
997.
特异性寡核苷酸探针检测胰岛素依赖型糖尿病病人HLA-DR基因频率 总被引:1,自引:0,他引:1
为了探讨HLA-DR基因在胰岛素依赖型糖尿病(IDDM)发病机制中的作用,利用聚合酶链反应技术及30个特异性寡核苷酸探针检测32例中国北方汉族IDDM病人及255名正常中国北方汉族人的HLA-DR基因频率的分布。结果IDDM组DR3和DR4频率分别为25.0%和40.6%,明显高于正常组(8.6%和18.6%),DR3和DR4的相对危险率分别为3.5l和3.10。提示DR3、DR,与IDDM易感性呈正相关。 相似文献
998.
A semi-automated method for measuring the potential for protein covalent binding in drug discovery 总被引:1,自引:0,他引:1
Day SH Mao A White R Schulz-Utermoehl T Miller R Beconi MG 《Journal of pharmacological and toxicological methods》2005,52(2):278-285
INTRODUCTION: Covalent protein binding of metabolically reactive intermediates of drugs has been implicated in drug toxicity including the occurrence of idiosyncratic drug toxicity. Investigators therefore would prefer to avoid developing compounds that produce significant amounts of reactive metabolites. By incubating the radiolabeled drug of interest with liver microsomes it is possible to evaluate the propensity of a drug candidate to covalently bind to proteins. METHODS: Here we present a semi-automated method in which a Brandel cell harvester is used to collect and wash proteins that have been incubated with radiolabeled drug. This method utilizes glass fiber filter paper to capture precipitated protein, rather than the more traditional exhaustive extraction/centrifugation approach. Using model compounds (including [14C]diclofenac, [3H]imipramine, [14C]naphthalene, and [14C]L-746530) we compare the covalent binding results obtained using this method to results generated using the traditional method and we performed cross-laboratory testing of assay reproducibility. RESULTS: It was found that results from new method correlated highly with the traditional method (R2=0.89). The cross-laboratory testing of the method showed an average interlaboratory coefficient of variation of only 18.4%. DISCUSSION: This method provides comparable results to the more traditional centrifugation-based method with considerable time and labor savings. 相似文献
999.
Mao IF Chen LT Wang YN Yang SF Chen HC Chen ML 《Archives of environmental contamination and toxicology》2005,49(2):141-149
This study involved sampling over 1 year of data on exposure to acid aerosols in the geothermal area of metropolitan Taipei. The temporal and spatial variations of the concentrations of acid aerosols were assessed by sampling at three sites: A, B, and C. Results indicate that the SO2 concentrations lead the concentrations of other acid aerosols at site C because two active fumaroles surround this site. The mean SO2 concentrations at sites A, B, and C were 2.4, 2.4, and 6.2 ppb. Previous studies have found that H2S levels were highest at site C. However, the SO4−2 and H+ concentrations among the three sites were similar. The mean aerosol SO4−2 concentrations were 7.0, 5.7, and 5.7 μg m−3 at sites A, B, and C, respectively; their H+ concentrations were 5.5, 4.2, and 5.4 nmolm−3. No seasonal variations are observed for most of the acid aerosols in the geothermal area except that the types of hot spring affect the SO4−2 concentration nearby. The different seasonal fluctuation among the sites reflect the determinant of SO4−2 emission from different geothermal sources. Sulfur-rich aerosols and some SO2 emitted from geothermal sources are obvious. The predominance of nitrogen-containing gases (sum of NO2 + HNO2 + HNO3) over SO2 indicates the importance of the anthropogenic origin of emissions. The effect of multiple exposures to sulfur-rich aerosol (including H2S, SO2, and SO4−2), H+, and nitrogen-containing aerosols on the health of nearby residents warrants concern. 相似文献
1000.
Decrease in anogenital distance among male infants with prenatal phthalate exposure 总被引:30,自引:0,他引:30
Swan SH Main KM Liu F Stewart SL Kruse RL Calafat AM Mao CS Redmon JB Ternand CL Sullivan S Teague JL;Study for Future Families Research Team 《Environmental health perspectives》2005,113(8):1056-1061
Prenatal phthalate exposure impairs testicular function and shortens anogenital distance (AGD) in male rodents. We present data from the first study to examine AGD and other genital measurements in relation to prenatal phthalate exposure in humans. A standardized measure of AGD was obtained in 134 boys 2-36 months of age. AGD was significantly correlated with penile volume (R = 0.27, p = 0.001) and the proportion of boys with incomplete testicular descent (R = 0.20, p = 0.02). We defined the anogenital index (AGI) as AGD divided by weight at examination [AGI = AGD/weight (mm/kg)] and calculated the age-adjusted AGI by regression analysis. We examined nine phthalate monoester metabolites, measured in prenatal urine samples, as predictors of age-adjusted AGI in regression and categorical analyses that included all participants with prenatal urine samples (n = 85). Urinary concentrations of four phthalate metabolites [monoethyl phthalate (MEP), mono-n-butyl phthalate (MBP), monobenzyl phthalate (MBzP), and monoisobutyl phthalate (MiBP)] were inversely related to AGI. After adjusting for age at examination, p-values for regression coefficients ranged from 0.007 to 0.097. Comparing boys with prenatal MBP concentration in the highest quartile with those in the lowest quartile, the odds ratio for a shorter than expected AGI was 10.2 (95% confidence interval, 2.5 to 42.2). The corresponding odds ratios for MEP, MBzP, and MiBP were 4.7, 3.8, and 9.1, respectively (all p-values < 0.05). We defined a summary phthalate score to quantify joint exposure to these four phthalate metabolites. The age-adjusted AGI decreased significantly with increasing phthalate score (p-value for slope = 0.009). The associations between male genital development and phthalate exposure seen here are consistent with the phthalate-related syndrome of incomplete virilization that has been reported in prenatally exposed rodents. The median concentrations of phthalate metabolites that are associated with short AGI and incomplete testicular descent are below those found in one-quarter of the female population of the United States, based on a nationwide sample. These data support the hypothesis that prenatal phthalate exposure at environmental levels can adversely affect male reproductive development in humans. 相似文献