POWER OF LOGRANK TEST AND COX REGRESSION MODEL IN CLINICAL TRIALS WITH HETEROGENEOUS SAMPLES

This paper evaluates the loss of power of the simple and stratified logrank tests due to heterogeneity of patients in clinical trials and proposes a flexible and efficient method of estimating treatment effects adjusting for prognostic factors. The results of the paper are based on the analyses of survival data from a large clinical trial which includes more than 6000 cancer patients. Major findings from the simulation study on power are: (i) for a heterogeneous sample, such as advanced cancer patients, a simple logrank test can yield misleading results and should not be used; (ii) the stratified logrank test may suffer some power loss when many prognostic factors need to be considered and the number of patients within stratum is small. To address the problems due to heterogeneity, the Cox regression method with a special hazard model is recommended. We illustrate the method using data from a gastric cancer clinical trial. © 1997 by John Wiley & Sons, Ltd.     

LOGRANK,PLAY THE WINNER,POWER AND ETHICS

We show by simulation and numerical integration techniques that power is largely unaffected by play the winner strategies in a typical chronic disease mortality trial utilizing the logrank test. This raises the issue of the ethics of equal allocation in such a setting.     

A MODIFIED ACROSOME INDUCTION TEST

Many types of acrosome induction tests require special equipment and reagents that are not available to most clinicians; thus, simpler tests seem desirable. A modified acrosome induction test has been developed that uses basic reagents and a light microscope, which are available in most office settings. A hypoosmotic swelling test and a double stain (Bismark brown and rose Bengal) were combined to evaluate the viable acrosome reaction (AR) among 74 infertile men and 42 control men. The study included 34 infertile males without varicoceles, 20 with nonrepaired varicoceles and 20 with repaired varicoceles. On each test day, a specimen from a fertile donor was run as a control. The spontaneous acrosome reaction was recorded in semen before and after capacitation. The final % viable acrosome reaction equaled the capacitated value minus the spontaneous value for whole semen. The mean % viable AR among the control specimens was 16% with no values less than 10%. This mean value for controls was significantly greater than the mean % viable AR in each patient group. There were no overlaps in the 95% confidence intervals. When the study group was stratified according to normal acrosome induction tests or >10% viable AR, 30 patients had a normal test and 44 had abnormal tests. Six patients with varicoceles and an abnormal acrosome induction test had a varicocelectomy, and 2 (33%) converted their acrosome induction test to normal after at least 6 months of follow-up. Nine patients had in vitro fertilization (IVF), 3 had a poor result, and all had an abnormal acrosome induction test. Six had a good result with IVF and all 6 had a normal acrosome induction test. Thus, the acrosome induction test described in this report may be performed in any office laboratory to detect subtle male factor problems. The results may be helpful for planning IVF, intracytoplasmic sperm injection, or varicocele surgery for infertile men.     

A SCREENING TEST FOR PHENYLKETONURIA

A blood test has been developed which can be applied to large numbers of neonates for early detection of this disease.     

分层分组护理管理模式在ICU护理中的应用

目的探讨分层分组护理管理模式在重症监护病房(ICU)护理工作中的应用与效果。方法根据中山市人民医院的52名ICU护理人员的年龄、学历、资历、职称等综合因素从高到低将其分为四层,从第一层中选出6名作为6个组的组长,再分别从其它层中选取2～3名护理人员合成一个组,每组8～9人。以组为单位进行ICU护理工作,对ICU护理人员进行分层培训。对分层分组护理管理前后的护理人员工作满意度及ICU护理质量进行分析比较。结果实行分层分组护理管理模式后,ICU护理人员的工作满意度及ICU护理工作的质量均较之前提高(p<0.05),差异具有统计学意义。结论在ICU护理工作中实行分层分组护理管理模式,在人力资源得到很好配置的同时,提高了护理人员的工作满意度与热情,整体上提升了ICU护理工作的质量。     

氯霉素竞争ELISA检测试剂盒的研制

目的应用抗氯霉素多克隆抗体,建立竞争ELISA分析方法,研制氯霉素残留快速检测试剂盒,并对其性能进行测定。方法选用抗氯霉素高特异性抗体,直接包被抗体后,将酶标记氯霉素和氯霉素标准品或样品加入预先包被了特异性抗体的孔内,建立直接竞争ELISA检测试剂盒。结果所选用的抗体对氯霉素亲和力高,与链霉素、四环素、土霉素、青霉素4种抗生素及克伦特罗的交叉反应率均小于0.01%;抗体的特异性强;检测质量浓度为50、10.5、0.5mg/ml样本时,平均变异系数为11.4%;对氯霉素残留检测的标准曲线为y=-14.843logx+56.692,R2=0.9965,线性范围为0.02～64.0ng/ml,检测限IC10为0.451ng/ml,灵敏度IC50为2.82ng/ml,样品的加标回收率为72%～113%。结论试剂盒检测的准确性和重现性较好,可用于批量虾肉、鸡肉、牛奶等样品中氯霉素残留的检测。     

锅炉司炉作业人员职业适性检测指标研究

通过指标筛选研究确定锅炉司炉作业人员职业适性检测指标体系。方法：采用Ｄｅｌｐｈｉ法对锅炉司炉作业人员职业适性指标进行了研究,咨询专家对各备择指标与对工作重要性及发生事故的关系进行了评估。结果专家积极程度与意见集中程度良好;事故重要性与工作重要性排序一致性良好;两者呈高度正相关。结论：筛选出与锅炉司炉作业人员职业适性有关的１３项生理、心理素质检测指标。     

A TEST FOR AN OSMOTIC EFFECT ON FOOD INTAKE REGULATION

Intravenous injection of water and hypertonic glucose and xylose caused only a small effect of short duration on food intake instead of the more drastic effect postulated by the osmotic theory of food intake regulation.     

危险的药物试验

27岁的爱沙尼亚小伙子凯尔德是帕尔努的一名会计。一天，他翻阅报纸时无意瞥见了一条消息，招聘某种“维生素实验”人员。当然，开出的条件是非常诱人的：免费提供赴瑞士的往返机票，在一家舒适的旅馆度过无忧无虑的两星期，还可获得数百美元。这可比在爱沙尼亚干几个月活儿的工资还要高许多呢!