混合效应模型在研究接触-效应关系中的应用

目的 用混合效应模型研究工人接苯水平与白细胞水平的关系及其影响因素,并确定最适接触剂量指标.方法 在21个体检年度分别对每个研究对象的每次体检时估算区域浓度、8 h时间加权平均浓度(TWA8)、年度接触水平和累积接触水平.将接触水平定义为协变量,白细胞计数定义为效应变量,用混合效应模型分析剂量效应关系.结果 共观察接苯对象147名26 292人月,白细胞计数样本1 147份、对照组66名14112人月白细胞计数样本396份.接触组、对照组白细胞计数平均水平分别为5.36×109,6.13×109/L.平均区域浓度、TWA8、年度接触水平和累积接触水平分别为5.10 mg/m3,4.69 mg/m3,72.90 mg/m3·月,783.70 mg/m3·月.4个混合效应模型均能收敛,其中以TWA8信息标准值最低.工人接苯水平增加、接触时间增长,白细胞水平下降.性别、吸烟与否对白细胞水平无明显影响.结论 工人接苯水平和时间明显影响工人白细胞水平,TWA8可能是最适接触剂量指标.     

Evaluation of human antibody responses to diphtheria toxin subunits A and B in various age groups

This study aimed to evaluate human antibody responses to diphtheria toxin subunits in various age groups. Antibodies against the intact diphtheria toxin and the diphtheria toxin subunits A and B were evaluated in 1319 individuals using a double-antigen ELISA. Although high levels of protection (83.6%, 95% CI 79.2-87.4) were found in children and adolescents, the middle-aged adult population was less protected (28.8%, 95% CI 24.3-33.6). An increase in age was associated with a decrease in the frequency of protected individuals in the 0-39-year age group (p <0.001). Anti-subunit B levels correlated well (p <0.01) with levels of antibodies against the intact toxin. In children aged < or =16 years, the intervals at which the peaks in geometric mean titres of anti-subunit B antibodies were observed were found to correlate with the ages at which booster doses are administered. Overall, males appeared to be more protected than females (OR 1.67, 95% CI 1.34-2.08, p <0.001). A small group of individuals had antibody levels of > or =0.1 IU/mL against the intact toxin, but did not have protective antibody against subunit B. Determination of anti-subunit B antibody levels should help in evaluating the effectiveness of diphtheria boosters and other aspects of diphtheria immunity.     

药物的定量构效关系的方法学研究——改进的逐步回归算法

在定量的构效关系研究中,多重回归分析选人的参数,多是用穷举所有方程实现的。本文提出一种改进的逐步回归算法,计算实例表明,是个行之有效的方法。     

Synthesis and cytotoxic activity of new alkyl[3-(2-chloroethyl)ureido]benzene derivatives

Several alkyl[3-(2-chloroethyl)ureido] (CEU) benzene derivatives were prepared as potential anticancer agents. These new compounds were readily prepared in good yields by addition of anilines to 2-chloroethylisocyanate. Their cytotoxic activity was evaluated on human breast cancer (MDA-MB-231), human colon adenocarcinoma (LoVo) and mouse lymphocytic leukemia (P388D₁) tumor cell lines. Several new CEUs were significantly more cytotoxic than the nitrogen mustard chlorambucil. The biological activity of these aromatic urea derivatives seems to be related to the nature and position of the alkyl substituents on the aromatic ring. Substitution by branched alkyl groups on position 4 of the aromatic ring led to cytotoxic molecules which are up to 5 times more potent than the standard chlorambucil.     

双氢杨梅树皮素对兔胸主动脉条平滑肌收缩反应的影响

用兔胸主动脉条研究双氢杨梅树皮素对去甲肾上腺素（NE）、KCl和CaCl2所致兔胸主动脉条收缩反应量效曲线的影响。双氢杨梅树皮素能显著地抑制NP、KCl和CaCl2所致兔胸主动脉杂的收缩，量效曲线右移，最大反应降低，对高K 所致兔胸主动脉条收缩的抑制作用明显大于NE所致兔胸主动脉条收缩的抑制作用。双氢杨梅树皮素对NE引起的依赖内Ca2 释放的收缩有明显抑制作用，而对NE依赖细胞外Ca2 性收缩区在较高浓度时才显示抑制作用，提示双氢杨梅树皮素可能对电压依赖性钙通道（PDC）有选择性阻滞作用。     

建立新型医患关系是医院工作的当务之急

《医疗事故处理条例》《最高人民法院关于民事诉讼证据的若干规定》这两个法规的出台，给医院提出了新的课题，结合目前实际，提出了医院全面贯彻执行这两个法规，必须从围绕改善医患关系这个中心问题入手。建立新型和医患关系，并根据多年的观察与实践，着重论述了如下见解：医务人员在为患者的攻关服务过程中，要真正认识自己是医患矛盾中的主要方面；医务人员要转变传统的服务思维定势，尊重和理解患者，医务人员要确立既为患者生命和利益负责，又重视患者权利的观念，医务人员要增强法制观念，做到依法行医，医院要设置监控部门或配备专兼职人员，对全院的医疗服务进行检查监督。     

两种剂量奥曲肽治疗食管及胃曲张静脉出血效果比较

①目的　比较两种剂量奥曲肽治疗食管、胃曲张静脉出血的临床效果。②方法　将 88例食管、胃曲张静脉出血病人随机分为奥曲肽 5 0 μg/h和 2 5 μg/h剂量组 ,观察平均止血时间、止血率、再出血率和不良反应。 ③结果　 5 0 μg/h组平均止血时间明显短于 2 5 μg/h组 (t=2 .2 4 ,P <0 .0 5 ) ,总止血率明显高于 2 5 μg/h组 (χ2 =5 .36 0 ,P <0 .0 5 ) ,再出血率较 2 5 μg/h组低 (χ2 =7.990 ,P <0 .0 5 )。两组均有 1例病人出现恶心。④结论　奥曲肽 5 0 μg/h剂量治疗食管、胃曲张静脉出血的效果优于 2 5 μg/h剂量     

Influence of the mother-child relationship on the development of the Type A Behavior Pattern

Investigation of the Type A Behavior Pattern (TABP) of pre-school children was conducted to determine the influence of the mother-child relationship on the development of TABP. The incidence of TABP was 44.2% (51.7% in boys and 38.7% in girls). The TABP tendency of the boys decreased as the manifest dissension or conflict in the family grew, in marked contrast with the tendency seen in girls, suggesting that conflict in the family can either weaken or reinforce TABP.     

In vitro determination of lung airway compliance in small animals

An in vitro method for obtaining pressure/volume curves from the lungs of small animals is described. The excised lungs were inflated and deflated with saline or air by a motor-driven syringe controlled by a microcomputer. The computer was programmed to display the curves in real time, correcting when necessary for the compressibility of air in the system. Volume compliance (K=dV/dP×1/V) was calculated by differentiating a polynomial fitted to the measured pressure/volume points. Repeatable curves were obtained from mice aged 24h (body weight 1·3±0·14g (SD), residual lung volume 8·43±1·5 μl (SD). A nonlinear decrease in differential compliance (K=dV/dP×1/V) with increasing strain was observed while the ratio K_saline/K_air increased from 2·5 to 10 over the range of strains investigated (ε=1–5). The relative surface tension (calculated from the difference between the pressures required to inflate the air and saline-filled organs to a given volume) increased exponentially with increasing volume. We conclude that it is now possible to obtain reproducible pressure/volume curves for lungs with a residual volume of less than 10 μl, from animals weighing approximately 1·5 g and, from these curves, estimate airway compliance and surface tension.     

Aromatic ethers of 1-aryl 2-(1H-azolyl)ethanol: study of antifungal activity

Aromatic ethers related to antifungal azole miconazole were synthesized and tested against various strains of Candida. We found that activity is related to the nature of the aromatic ring and the position of substituents on this ring. Activity is more strongly dependent on the substituent in the 2 position of the ethyl chain than on the aromatic group linked through the oxygen. Triazoles were always less potent than the corresponding imidazole analogues.