腰椎节段形态对峡部、小关节应力及小关节接触力影响的有限元分析

目的:探讨腰椎形态结构变化对峡部裂性滑脱及小关节退变的作用和意义。方法:采用改良的“非种子区域分割方法”及非平行“最佳切割平面”等一系列新型计算机辅助设计(CAD)方法精确建立包括椎间盘高度、腰椎小关节角、椎间盘前凸角改变的L4~L5活动节段有限元模型;在2700N轴向压缩载荷条件下,分别对各有限元模型的峡部、小关节应力、小关节接触力以及椎间盘负载进行测试。结果:压缩载荷下,腰椎活动节段峡部、小关节等效应力及小关节接触力随椎间盘高度的减小而减小,随小关节角的增大而增加,随椎间盘前凸角的增加而减小。结论:椎间盘高度、腰椎小关节角、椎间盘前凸角等形态结构变化对腰椎节段有限元模型的峡部、小关节应力及小关节接触力有明显的影响。提示腰椎峡部应力性骨折及小关节退变的发生与椎间盘高度、腰椎小关节角、椎间盘前凸角等解剖形态因素有关。     

Preparation of leukocyte-poor platelets by filtration

There is evidence that leukocyte contaminating red blood cells and platelet concentrates are responsible for refractoriness to platelet transfusions. The efficacy of a cotton-wool filter to remove leukocytes from red blood cells has been documented previously. The present study was designed to evaluate whether the cotton-wool filters can effectively remove leukocytes from platelet concentrates. Sixty pools of random-donor platelets and single-donor plateletpheresis products were filtered through a cotton-wool filter. The efficacy of filtration was determined by measuring the absolute numbers of leukocytes and platelets and subpopulations of mononuclear cells. The average platelet loss was 8% per pool of random platelets and 10% per plateletpheresis product. The average leukocyte removal was 99% from a pool of random platelets and plateletpheresis concentrates collected by CS-3000 and 90% from plateletpheresis concentrates harvested by single-stage COBE/IBM-2997. The filtration removed 100% of granulocytes, 95% of monocytes, 90% of B-lymphocytes, and 85% of T-lymphocytes. We conclude that filtration through a cotton-wool filter is an efficient and cost-effective method for preparation of leukocyte-poor platelets.     

中医中药不容诋毁——驳《告别中医中药》谓中医"不仁"等谬论

文章根据《告别中医中药》一文中谓中医“不仁”等某些观点,以历史唯物主义和辩证唯物主义的观点,从中医理论的博大精深、中药产业及其现代化研究进展、中医的临床疗效以及中医传承的良好的医德医风诸方面进行了有力的驳斥。     

Effectiveness of a hospital-wide selective screening programme for methicillin-resistant Staphylococcus aureus (MRSA) carriers at hospital admission to prevent hospital-acquired MRSA infections

Screening of potential MRSA-positive patients at hospital admission is recommended in German and international guidelines. This policy has been shown to be effective in reducing the frequency of nosocomial MRSA transmissions in the event of an outbreak, but the influence of screening on reducing hospital-acquired MRSA infections in a hospital setting where MRSA is endemic is not yet well-documented. This study describes the effect of hospital-wide screening of defined risk groups in a 700-bed acute care hospital during a period of 19 months. In a cohort study with a 19-month control period, the frequencies of hospital-acquired MRSA infections were compared with and without screening. In the control period, there were 119 MRSA-positive patients, of whom 48 had a hospital-acquired MRSA infection. On the basis of this frequency, a predicted total of 73.2 hospital-acquired MRSA infections was calculated for the screening period, but only 52% of the expected number (38 hospital-acquired MRSA infections) were observed, i.e., 48% of the predicted number of hospital-acquired MRSA infections were prevented by the screening programme. The screening programme was performed with minimal effort and can therefore be recommended as an effective measure to help prevent hospital-acquired MRSA infections.     

Parental Communication Not to Smoke and Adolescent Cigarette Smokers' Readiness to Quit: Differences by Age

There is limited information on the relationship between parental practices that specifically discourage current cigarette smoking and adolescent cessation, and how this relationship varies by age. Among 1629 adolescent smokers, self-reported receipt of parental communication not to smoke was significantly and positively associated with readiness to quit. The strength and significance of this association decreased from early to middle adolescence and was not significant in late adolescence.     

军队在职干部腰身指数与心血管危险因素相关性探讨

目的 研究用腰身指数（腰围/身高比值WHtR）作为腹型肥胖指标探讨与心血管危险因素的相关性。方法 对2005年3月～2006年12月入住广州疗养院的军队在职干部共495人进行身高、体重、腰围、血压、心率、生化等检测,并进行统计学分析。结果 腰身指数异常组的年龄、体重、SBP、DBP、FBS、TC、TG以及尿酸均显著高于腰身指数正常组,HDL-C的结果则相反（P〈0.01～P〈0.001）;同时腰身指数与年龄、体重、SBP、DBP、FBS、TC、TG呈显著正相关,与HDL-C呈显著负相关（P〈0.05～P〈0.001）。结论 腰身指数可作为有效的腹型肥胖参考指标,腰身指数异常者其心血管危险因素水平比正常者高,及时控制腰身指数可以有效改善人群的健康状况。     

Measurement in clinical trials: A neglected issue for statisticians?

Biostatisticians have frequently uncritically accepted the measurements provided by their medical colleagues engaged in clinical research. Such measures often involve considerable loss of information. Particularly, unfortunate is the widespread use of the so‐called ‘responder analysis’, which may involve not only a loss of information through dichotomization, but also extravagant and unjustified causal inference regarding individual treatment effects at the patient level, and, increasingly, the use of the so‐called number needed to treat scale of measurement. Other problems involve inefficient use of baseline measurements, the use of covariates measured after the start of treatment, the interpretation of titrations and composite response measures. Many of these bad practices are becoming enshrined in the regulatory guidance to the pharmaceutical industry. We consider the losses involved in inappropriate measures and suggest that statisticians should pay more attention to this aspect of their work. Copyright © 2009 John Wiley & Sons, Ltd.     

基于免疫系统非线性模型对中医正邪相争理论和扶正祛邪治则的一个非线性动力学诠释

文中基于免疫系统有关免疫活性细胞或分子与外来抗原相互作用的非线性的动力学模型对中医学正邪相争理论及其扶正祛邪治则进行了新的诠释,提出了新的研究思路。认为:中医学关于外感邪气致病的六经、卫气营血和三焦辨证在本质上是识别抗原与免疫活性细胞或分子相互作用的三种不同的非线性动力学诊断模式,其证相应于这一过程中不同的非线性动力状态,可以用一个或一组非线性动力学方程进行定量描述。一个证常常对应于抗原与免疫活性的细胞或分子非线性动力学相互作用相空间中的一个稳定或不稳定的极限环和混沌,这可以作为证诊断的图形或形象标识。以中医学扶正祛邪的治疗思想为先导,有可能研制出全新靶向的和更有效的治疗传染性疾病的药物。     

腹腔镜胆囊切除术转开腹可能性评分系统建立和运用

目的　根据术前临床资料建立预测腹腔镜胆囊切除术转开腹可能性的评分系统。方法　对邵逸夫医院 1994年 4月 4日至 2 0 0 1年 6月 30日的 7134例LC的术前临床资料进行单因素分析 ,筛选出中转开腹的危险因素 ,再进行logistic多元回归分析。男性、高龄 (≥ 6 5岁 )、上腹部手术史、糖尿病、总胆红素升高 (≥ 1 2mg/dl)、胆囊壁增厚 (≥ 4cm )、胆总管直径增宽 (≥ 8cm)、急性胆囊炎是转开腹的危险因素并被分别赋值 ,建立预测转开腹可能性的评分系统。计算 7134例LC的综合得分 ,比较不同得分组转开腹率。用ROC曲线评价该评分系统的效能。 2 0 0 1年 7月 1日至 2 0 0 1年 12月 31日 938例LC运用该评分系统 ,比较各得分组转开腹率的差异。结果　 7134例LC中各组得分越高 ,转开腹率越高 ,且多数相邻两组的转开腹率有显著性差异 (P <0 0 1)。ROC曲线以下面积为0 81,标准误为 0 0 1。 938例LC中的各组也是得分越高 ,转开腹率越高 ,且多数相邻两组的转开腹率有显著性差异 (P <0 0 5 )。结论　根据危险因素预测LC转开腹可能性 ,以指导临床工作。