修订车间空气中溶剂汽油容许浓度的研究

通过对969例汽油作业工人的体格检查和对86个作业点760次车间内汽油浓度的测定结果表明,在达标的条件下,工人仍有神经衰弱,植物神经功能障碍的临床症状,说明现行车间的卫生标准应当进行修订。根据动物实验资料计算 MAC,180汽油为198.6mg/m~3,120汽油为225.0mg/m~3,二者相差不大,我们建议车间空气中溶剂汽油容许浓度可修订为200mg/m~3。     

Steady-state kinetics of bezafibrate and clofibrate in healthy female volunteers

Summary The steady-state kinetics of chlorophenoxyisobutyric acid (CPIB) and of bezafibrate were investigated in a strictly controlled, randomised cross-over study in 10 female volunteers, after the conventional oral doses of clofibrate 0.5 g and bezafibrate 0.2 g at 8-h intervals. The mean steady-state concentration of CPIB in serum was 34 times higher than that of bezafibrate, which was due to the considerable cumulation of CPIB, whereas no cumulation of bezafibrate was observed. This is supported by comparison of the AUCs, and of the maximum and mean concentrations of bezafibrate after the first and last doses. (0.44 and 0.49 h^–1) and the half-lives (1.6 and 1.4 h) were almost identical after the first and last doses of bezafibrate. The median total clearances of CPIB and bezafibrate amounted to 10.5 and 142.5 ml/min, respectively, if complete absorption of both drugs is assumed. Since the apparent volumes of distribution were in the same range for both drugs, the amount of drug present in the organism in steady-state also differed by a factor of approximately 30 under the usual dosage regimen.     

朱砂汞在大鼠体内的蓄积性研究

目的:探讨人鼠长期给予朱砂后汞在血液、肝脏、肾脏和脑组织中的蓄积性,为阐明朱砂的中毒机制和为临床安全用药提供科学依据.方法:①禁食16 h后的SD大鼠随机分为对照组(4只)和朱砂0.8 g·kg~(-1)组(28只).朱砂组灌胃给药1次,于给药后0.5,1,2,4,8,16,36 h时间点各取4只大鼠,取全血、肝脏、.肾脏和脑组织,测定汞含量.对照组的脏器样本一次性摘取.②SD大鼠随机分为对照组和朱砂0.1,0.4,0.8 g·kg~(-1)剂量组.朱砂各剂量组每日灌胃给药1次,共给药3个月.于末次给药后16 h取血、肝、肾、脑,测定汞含量.结果:单次给予朱砂0.8 g·kg~(-1)后,大鼠血液、肝脏、'肾脏、脑组织中的汞含量均有所增高,从高至低顺序为:肝脏＞血液＞脑＞肾脏.朱砂反复给药3个月后,大鼠肾脏和脑组织汞蓄积量较大.朱砂0.8 g·kg~(-1)组的肾脏和脑组织的汞蓄积倍数分别高达71.2,27.4倍.而肝脏汞蓄积量较少,蓄积倍数低于2倍.其中,肾脏的汞蓄积量占4种脏器汞蓄积总量的95%以上.尽管肾脏和肝脏的汞蓄积量相差悬殊,但朱砂以≥0.1 g·kg~(-1)剂量给药3个月,即可造成肾脏毒性,也可造成肝脏毒性.结果表明,朱砂的肾脏毒性与汞在肾脏的蓄积有关;而肝脏可能对汞更敏感.脑组织汞蓄积倍数高达20倍以上,但动物一般状况、外观行为以及脑组织形态学未见明显变化,表明大鼠的脑可能对汞敏感性不高.结论:朱砂的可溶性汞可吸收入体内.长期用药后,汞可在肾脏、脑、肝脏组织中蓄积,其中肾脏的汞蓄积量最大.大鼠在3个月内累积摄入可溶性汞约194μ g·kg~(-1)可能导致中毒.     

Antipyrine metabolite formation and excretion in patients with chronic renal failure

Summary In the present study the influence of chronic renal insufficiency on antipyrine clearance, metabolite formation and excretion was investigated in 8 patients. After oral administration of antipyrine, the parent compound, its metabolites and their conjugates were assayed in plasma and urine. Besides the parent drug, 3-hydroxymethylantipyrine (HMA) was present in plasma in the free and conjugated forms, whereas 4-hydroxyantipyrine (OHA) and norantipyrine (NORA) were found only in the conjugated form. The same was true for urine. The plasma concentrations of these metabolites are too low to be measured in subjects with normal renal function.Plasma antipyrine clearance in the patients was in the same range as in healthy subjects. Investigation of metabolite kinetics, however, revealed that the rate of formation of NORA was preferentially decreased, whereas that of OHA and HMA were unaltered. Renal clearance of the metabolites of antipyrine was severely impaired in patients with renal insufficiency, and the resulting accumulation made it possible for the first-time to measure the antipyrine metabolites in plasma. Mean residence times of metabolites were longer than that of the parent compound. Renal clearances of the conjugates were correlated with the creatinine clearance, but were somewhat higher. Renal clearance of free HMA was lower and was also correlated with creatinine clearance.The mean clearance for glucuronidation of HMA was 93.1 ml/min. The results suggest that in healthy subjects Phase I metabolism is the rate-limiting step in the elimination of antipyrine, which is essential for its application as a model drug in metabolism studies.     

Paracetamol disposition and metabolite kinetics in patients with chronic renal failure

Summary The disposition of paracetamol following an oral dose of 1.0 g was compared in 10 healthy volunteers, 7 patients with moderate chronic renal failure and 6 patients with end stage renal failure on maintenance haemodialysis.Paracetamol absorption was normal in the patients with renal failure. The mean plasma half-life of paracetamol from 2 to 8 h was similar in the 3 groups (2.1 to 2.3 h) but from 8 to 24 h it disappeared much more slowly in the renal failure patients (half-life 11.7 compared with 4.9 h in the healthy volunteers). Plasma concentrations of paracetamol glucuronide and sulphate conjugates were greatly increased in the patients with moderate renal failure and the mean plasma half-lives were 30.5 and 21.8 h respectively compared with about 3 h in the healthy volunteers. Plasma concentrations of these metabolites were even higher in the dialysis patients and there was no significant fall over 24 h. The cysteine and mercapturic acid conjugates of paracetamol could only be measured in plasma in the patients with renal failure and concentrations were very low.The fractional urinary recovery of paracetamol and its glucuronide, sulphate, cysteine and mercapturic acid conjugates was similar in healthy volunteers and patients with moderate renal failure. The mean renal clearances of paracetamol and its glucuronide and sulphate conjugates in the healthy volunteers and patients with moderate renal failure were 15.7, 137 and 172, and 5.9, 14.5 and 14.8 ml/min respectively. In the latter patients the mean renal clearances of the cysteine and mercapturic acid conjugates were much greater at 35.4 and 80.2 ml/min. In the patients with moderate renal failure the AUC's of the glucuronide and sulphate conjugates were related to the plasma creatinine and there were significant negative correlations with the renal clearances of these metabolites and total urinary recovery. Marked cumulation of the polar glucuronide and sulphate conjugates of paracetamol would seem inevitable in patients with renal failure and the parent drug is apparently regenerated to a limited extent from retained metabolites.     

复硝钠的蓄积性和诱变性研究

本文对新农药复硝钠的急性毒性、蓄积毒性和致突变性进行了研究。试验结果表明,复硝钠属低毒农药,在动物体内的蓄积性比较低。通过Ames试验、小鼠骨髓细胞微核试验和精子畸变试验的结果可以看出,复硝钠没有导致基因突变而改变体细胞和生殖细胞中的遗传信息,故未出现诱变作用。     

绿茶提取物的安全性分析评价

目的　对调节血糖产品-绿茶提取物的安全性进行评价。方法　采用急性经口毒性试验、蓄积毒性试验、小鼠骨髓嗜多染红细胞微核试验、V79细胞基因突变试验对绿茶提取物的急性毒性、蓄积毒性、遗传毒性进行观察。结果　该提取物对雌、雄性小鼠急性经口LD50 均>10 0 0 0mg/ (kg·bw) ,属于实际无毒级;对动物蓄积系数K >5 ,属于弱蓄积性;对小鼠骨髓细胞未产生致畸变作用;对体外培养的中国仓鼠肺细胞(V79) ,无论直接作用和代谢活化后作用,均未呈现致突变性。结论　绿茶提取物是一种安全的调节血糖制剂。     

盐酸特比萘芬凝胶的透皮吸收

OBJECTIVETo investigate the transdermic absorption and cumulative amounts in vivo after dermic administration of 1% agar of terbinafini hydrochloridum.METHODNew Zealand white rabbits were used in this experiment. Eight grams of the agar was coated on back     

盐酸特比萘芬溶液的透皮吸收

目的观察1%盐酸特比萘芬溶液经皮肤给药后药物在体内的吸收性和蓄积性。方法6只新西兰大白兔,每兔皮肤单次涂药液8ml·d-1,收集24h内药时血样。随后连续涂药液7d,收集每日峰、谷浓度血样,用高效液相色谱(HPLC)测定兔血清特比萘芬血药浓度。结果药物透皮吸收3hCmax8.3±3.7μg·L-1,随着血药浓度下降维持一个较低水平。连续7d,药峰浓度在d3达10.5±3.0μg·L-1,随后数日峰浓度维持于一平台水平,谷浓度无明显变化。结论1%盐酸特比萘芬溶液没有体内累积现象。