气温变化与心脑血管疾病急诊关系的病例交叉研究

目的 探讨北京市日平均气温与心脑血管疾病急诊(ICD-10:I00～I99)的关系,研究气温变化对心脑血管疾病的影响.方法 收集北京大学第三医院急诊科心脑血管疾病急诊资料、北京市气象资料和北京市大气污染物数据,应用时间分层的病例交叉设计研究方法分析春季(3-5月)、夏季(6-8月)、秋季(9-11月)、冬季(12-2月)日平均气温与心脑血管疾病急诊的关系.结果 在控制二氧化硫(SO2)、二氧化氮(NO2)及大气可吸入颗粒物(PM10)影响的情况下,春季、夏季、秋季、冬季当日平均气温对心脑血管疾病急诊的影响最大,平均气温每升高1℃与心脑血管疾病急诊的OR值分别为1.282(95%CI:1.250 ～1.315)、1.027(95% CI:1.001～1.055)、0.661(95% CI:0.637～0.687)、0.960(95%CI:0.937～0.984),关联有统计学意义(P<0.05).当同时调整相对湿度、风速、大气压强的影响时,春季、夏季、秋季、冬季平均气温与心脑血管疾病急诊的OR值分别为1.423(95%CI:1.377～1.471)、1.082(95%CI:1.041～1.124)、0.633(95%CI:0.607～0.660)、0.971(95%CI:0.944～1.000).关联有统计学意义(P<0.05).结论 春季、夏季日平均气温升高可以导致心脑血管疾病急诊人次增加,说明春夏季气温升高对心脑血管疾病患者是危险因素,应注意防暑;秋季、冬季气温升高可以导致心脑血管疾病急诊减少,说明秋冬季气温升高对心脑血管疾病患者是保护性因素,应注意保暖.     

Prime–boost vaccination with a fowlpox vector and an inactivated avian influenza vaccine is highly immunogenic in Pekin ducks challenged with Asian H5N1 HPAI

The efficacy of different vaccination schedules was evaluated in 17-day-old Pekin ducks using an experimental inactivated whole virus vaccine based on the H5N9 A/chicken/Italy/22A/98 isolate (H5N9-It) and/or a fowlpox recombinant (vFP-H5) expressing a synthetic HA gene from an Asian H5N1 isolate (A/chicken/Indonesia/7/2003). Full protection against clinical signs and shedding was induced by the different vaccination schemes. However, the broadest antibody response and the lowest antibody increase after challenge were observed in the group of ducks whose immune system was primed with the fowlpox vectored vaccine and boosted with the inactivated vaccine, suggesting that this prime-boost strategy induced optimal immunity against H5N1 and minimal viral replication after challenge in ducks. In addition, this prime-boost vaccination scheme was shown to be immunogenic in 1-day-old ducklings.     

Chemopreventive effect of raw and cooked lentils (Lens culinaris L) and soybeans (Glycine max) against azoxymethane-induced aberrant crypt foci

Although lentils (Lens culinaris L) contain several bioactive compounds that have been linked to the prevention of cancer, the in vivo chemopreventive ability of lentils against chemically induced colorectal cancer has not been examined. Our present study examined the hypothesis that lentils could suppress the early carcinogenesis in vivo by virtue of their bioactive micro- and macroconstituents and that culinary thermal treatment could affect their chemopreventive potential. To accomplish this goal, we used raw whole lentils (RWL), raw split lentils (RSL), cooked whole lentils (CWL), and cooked split lentils (CSL). Raw soybeans (RSB; Glycine max) were used for the purpose of comparison with a well-studied chemopreventive agent. Sixty weanling Fischer 344 male rats, 4 to 5 weeks of age, were randomly assigned to 6 groups (10 rats/group): the control group (C) received AIN-93G diet, and treatment leguminous groups of RWL, CWL, RSL, CSL, and RSB received the treatment diets containing AIN-93G+5% of the above-mentioned legumes. After acclimatization for 1 week (at 5th to 6th week of age), all animals were put on the control and treatment diets separately for 5 weeks (from 6th to 11th week of age). At the end of the 5th week of feeding (end of 11th week of age), all rats received 2 subcutaneous injections of azoxymethane carcinogen at 15 mg/kg rat body weight per dose once a week for 2 consecutive weeks. After 17 weeks of the last azoxymethane injection (from 12th to 29th week of age), all rats were euthanized. Chemopreventive ability was assessed using colonic aberrant crypt foci and activity of hepatic glutathione-S-transferases. Significant reductions (P < .05) were found in total aberrant crypt foci number (mean ± SEM) for RSB (27.33 ± 4.32), CWL (33.44 ± 4.56), and RSL (37.00 ± 6.02) in comparison with the C group (58.33 ± 8.46). Hepatic glutathione-S-transferases activities increased significantly (P < .05) in rats fed all treatment diets (from 51.38 ± 3.66 to 67.94 ± 2.01 μmol mg⁻¹ min⁻¹) when compared with control (C) diet (26.13 ± 1.01 μmol mg⁻¹ min⁻¹). Our findings indicate that consumption of lentils might be protective against colon carcinogenesis and that hydrothermal treatment resulted in an improvement in the chemopreventive potential for the whole lentils.     

Designs for dose–escalation trials with quantitative responses

In a dose–escalation trial for a new drug, each successive dose is tested on a new cohort of volunteer subjects, so that if any dose produces severe adverse reactions then higher doses are not tested. However, if there are other differences between the cohorts, such as differences in environmental health factors, type of person or experimental procedure, then these differences may obscure the differences between doses. Therefore, cohorts should be fitted in the analysis, as either fixed or random effects. I suggest that, if this is done, then there are three simple principles that reduce variance (i) allocating no more than half the subjects in any cohort to any single dose; (ii) subject to safety constraints, using as many different doses as possible in each cohort; (iii) using one more cohort than the number of doses, without increasing the total number of subjects. Using these principles, I propose some new designs that conform to the safety rules of traditional dose–escalation trials while reducing the variance of the estimators of differences between the doses by a factor of two or more, for the same number of subjects. Copyright © 2009 John Wiley & Sons, Ltd.     

Re-estimating the sample size of an on-going blinded trial based on the method of randomization block sums

We extend a method we had previously described (Statist. Med. 2005) to estimate the within-group variance of a continuous endpoint without breaking the blind in a randomized clinical trial. Specifically, we: (a) explain how the method may be used for a wider set of designs than we had previously indicated; (b) obtain a within-group, covariate-adjusted, blinded variance estimator; (c) illustrate use of the method for sample size re-estimation; and (d) describe a procedure to determine whether or not the blinded variance estimator works well not just on average but for the data set at hand. The proposed method is simple to use and makes no additional assumptions than is made for unblinded analysis. Simulations show that for realistic sample sizes there is virtually no inflation in the Type I error rate. When weighing the burden imposed by interim unblinded re-estimation with the loss in precision with blinded re-estimation, it may be advantageous for some trials to use the blinded method.     

患者自测腋温在临床运用的研究

目的：了解目前临床上患者自测腋温与护士按教科书规定的规范化测量腋温的测量结果是否有差异,讨论可否将自测腋温应用于临床。方法：对同一患者,在最接近的时问内先后采取让患者自测腋温与护士规范化测量腋温各-次,合计782例,采用统计描述及配对样本t检验的统计方法对结果进行处理。结果：临床患者自测腋温所测得的体温值与护士按教科书规定的规范化测量腋温所测得的体温值差异无统计学意义。结论：临床让患者自测体温的方法具有可行性、实用性。建议将体温测量作为临床护理健康教育内容之一,同时加强临床腋温操作的监督管理。     

临床路径应用于胆囊结石腹腔镜胆囊切除术的变异分析与管理

目的分析临床路径应用于胆囊结石腹腔镜胆囊切除术的变异情况及管理措施。方法选取我院实施胆囊结石腹腔镜切除术临床路径患者92例,详细记录并说明变异情况,按不同评价方法对变异进行分析。结果正性变异发生率为73．91％,负性变异发生率为26．09％;疾病转归造成的变异发生率为56．52％,医务人员造成的变异发生率为33．70％,医院系统造成的变异发生率为6．52％,病人需求所造成的变异发生率为3．26％：可控变异发生率为43．22％,不可控变异发生率为56．78％。结论通过对胆囊结石腹腔镜胆囊切除术临床路径变异情况的分析,有利于医疗质量持续改进,并为科学制定临床路径提供依据。     

野战运血车在长途血液运输中的性能测试

目的：测试野战运血车在不同温度案件下的保温、制冷和油耗等性能,为保障战争或突发情况下血液运输的安全、可靠提供基本依据.方法：2台野战运血车按最大容量装载血液,一辆车装红细胞悬液．另一辆装冰冻血浆。在35℃以上和25℃以下运行的外环境下,分别测试其无动力源情况下维持或制冷至冷冻或冷藏温度的时间和油耗。结果：在上述的条件下,野战运血车的保温时间为1．5—7h,制冷时间为15-138min。内置制冷系统的一箱油（20L）维持的运行时间为5-7h.结论：在长途运血时,如不能确保运血车的制冷系统正常运行,且运输时间超过一定的时限．则必须考虑多种保温方法联合使用     

高温作业工人197名心电图分析

目的了解高温作业工人心电图的改变。方法对197名高温作业工人心电图检查结果与对照人群进行比较。结果高温作业工人心电图改变异常率为44.67％,明显高于对照组的25．63％,差异有统计学意义（P〈0.01）,主要改变为窦性心动过缓、窦性心律不齐。结论接触高温对心脏产生一定影响,应加强防护措施。