重组人粒细胞-巨噬细胞集落刺激因子乳酸链球菌表达载体的构建

目的:构建重组人粒细胞-巨噬细胞集落刺激因子乳酸链球菌表达载体,为进一步研究人粒细胞-巨噬细胞集落刺激因子在乳链菌的表达及其治疗价值奠定基础。方法:实验于2005-04/2006-03在南方医科大学南方医院消化病研究所完成。①载体pNCSF的构建:将质粒集落刺激因子及含有P59启动子、USP45蛋白信号肽的pNBC1000质粒分别加入BamH Ⅰ和Pst Ⅰ进行双酶切,并用Apa Ⅰ、Sac Ⅰ进行双酶切鉴定,重组质粒命名为pNCSF。②SDGFP的TA克隆及载体pNCSFGFP的构建:将经过优化适合在乳链菌表达的人粒细胞-巨噬细胞集落刺激因子基因克隆于含有P59启动子、USP45蛋白信号肽的pNBC1000载体,得到重组质粒pNCSF;同时设计上下游引物经PCR扩增增强荧光表达蛋白(EGFP),TA克隆后经测序验证,再连接于pNCSF获得重组质粒pNCSFGFP。③载体pTRCSF、pTRCSFGFP的建立:将获得的pNCSF和pNCSFGFP进一步克隆于穿梭载体pTR1001c,以获得人粒细胞-巨噬细胞集落刺激因子乳链菌表达载体pTRCSF及pTRCSFGFP。结果:①载体pNCSF构建结果:酶切鉴定产物经1.0%的琼脂糖凝胶电泳后,发现有(含启动子P59、信号肽USP45、人粒细胞-巨噬细胞集落刺激因子)720bp的目的片段。②SDGFP的TA克隆及载体pNCSFEGFP的构建结果:SDGFP阳性克隆产物经EcoRⅠ酶切鉴定得到775bp目的片段。pNCSFEGFP酶切鉴定产物经1.0%的琼脂糖凝胶电泳后,发现有(含启动子P59、信号肽USP45、人粒细胞-巨噬细胞集落刺激因子、SDGFP)1495bp的目的片段。③穿梭质粒pTRCSF、pTRCSFGFP酶切鉴定结果:经Xba Ⅰ、Sac Ⅰ进行双酶切鉴定,分别得到约717bp、1492bp大小目的片段。结论:获得了人粒细胞-巨噬细胞集落刺激因子乳链菌表达载体pTRCSF及pTRCSFGFP,并经酶切鉴定和测序证实。     

A sequential density-based empirical likelihood ratio test for treatment effects

In health-related experiments, treatment effects can be identified using paired data that consist of pre- and posttreatment measurements. In this framework, sequential testing strategies are widely accepted statistical tools in practice. Since performances of parametric sequential testing procedures vitally depend on the validity of the parametric assumptions regarding underlying data distributions, we focus on distribution-free mechanisms for sequentially evaluating treatment effects. In fixed sample size designs, the density-based empirical likelihood (DBEL) methods provide powerful nonparametric approximations to optimal Neyman-Pearson–type statistics. In this article, we extend the DBEL methodology to develop a novel sequential DBEL testing procedure for detecting treatment effects based on paired data. The asymptotic consistency of the proposed test is shown. An extensive Monte Carlo study confirms that the proposed test outperforms the conventional sequential Wilcoxon signed-rank test across a variety of alternatives. The excellent applicability of the proposed method is exemplified using the ventilator-associated pneumonia study that evaluates the effect of Chlorhexidine Gluconate treatment in reducing oral colonization by pathogens in ventilated patients.     

拉米夫定抗乙型肝炎病毒治疗中耐药突变的后续治疗

拉米夫定(lamivudine)抗乙型肝炎病毒治疗中耐药突变发生率高,文献报道在拉米夫定治疗1,2,3,4,5a时分别为14%,38%,49%,66%,69%.耐药突变可导致血清HBVDNA水平阳转或明显上升,肝功能严重受损,甚至病情恶化死亡.关于拉米夫定抗乙型肝炎病毒治疗中耐药突变的后续治疗目前国内外尚无统一用药方案,单药治疗(如:继续使用拉米夫定、阿德福韦、恩替卡韦)在临床使用中已经取得了一定疗效,联合抗病毒治疗和中医药治疗是今后研究的方向.     

The reliability of determining “leg dominant pain”

Background contextPatients with back dominant pain generally have a worse prognosis after spine surgery when compared with patients with leg dominant pain. Despite the importance of determining whether patients with lumbar spine pain have back or leg dominant pain as a predictor for success after decompression surgery, there are limited data on the reliability of methods for doing so.PurposeTo assess the test-retest reliability of a patient's ability to describe whether their lumbar spine pain is leg or back dominant using standardized questions.Study design/settingProspective, blinded, test-retest cohort study performed in an academic spinal surgery clinic.Patient sampleConsecutive patients presenting for consultation to one of three spinal surgeons for lumbar spine pain were enrolled.Outcome measuresEight questions to ascertain a patient's dominant location of pain, either back dominant or leg dominant, were identified from the literature and local experts.MethodsThese eight questions were administered in a test-retest format over two weeks. The test-retest reliability of these questions were assessed in a self-administered questionnaire format for one group of patients and by a trained interviewer in a second group.ResultsThe test-retest reliability of each question ranged from substantial (eg, interviewer-administered percent question, weighted kappa=0.77) to slight (eg, self-administered pain diagram, weighted kappa=0.09). The Percent question was the most reliable in both groups (self-administered, interviewer). All questions in the interviewer-administered group were significantly (p<.001) more reliable than the self-administered group. Depending on the question, between 0% and 32% of patients provided a completely opposite response on test-retest. There was variability in prevalence of leg dominant pain, depending on which question was asked and there was no single question that identified all patients with leg dominant pain.ConclusionA patient's ability to identify whether his or her lumbar spine pain is leg or back dominant may be unreliable and depends on which questions are asked, and also how they are asked. The Percent question is the most reliable method to determine the dominant location of pain. However, given the variability of responses and the generally poorer reliability of many specific questions, it is recommended that multiple methods be used to assess a patient's dominant location of pain.     

普通教师与特殊教育教师职业倦怠和教学效能感的比较

目的:比较普通教育教师和特殊教育教师的职业倦怠与教学效能感特点,分析其影响因素。对象:①采用Maslach教师职业倦怠问卷和教师教学效能感量表于2006-06/09根据年龄、性别、教龄及是否担任班主任等对重庆市200名普通教育教师、100名特殊教育教师的职业倦怠和教学效能感的现状进行调查。Maslach教师职业倦怠问卷包括22个条目共3个维度:情绪衰竭、去人性化、低成就感。教师教学效能感量表共27个条目,包括一般教育效能感和个人教学效能感,各个维度总分相加形成总效能感。两个量表/问卷各题项均采用5点计分,分数越高,表示职业倦怠感越严重,教学效能感越强。②计量差异比较采用t检验和方差分析,并应用相关分析以及逐步回归分析统计学方法。结果:普通中小学共发放200份问卷,收回有效问卷176份,有效率占91.7%;特殊教育学校共发放100份问卷,收回有效问卷76份,有效率为80%。①职业倦怠和教学效能评分差异:普教与特教教师之间的职业倦怠感存在着显著的差异(t=2.837,P<0.01),普教教师与特教教师职业倦怠感的差异主要体现在情感衰竭维度上[普教:(3.16±0.71)分,特教:(2.63±0.65)分,t=5.535,P<0.01];去人性化和低成就感维度上无显著差异。普教教师的一般教育效能感得分显著低于特教教师[(3.40±0.66),(3.70±.57)分,t=-3.391,P<0.01]。②职业倦怠感和教学效能的人口学差异:除5年及以下教龄的教师外,普教与特教教师在性别、教龄及是否班主任等方面存在着情感衰竭方面的显著差异(P<0.05～0.01)。除6～10年教龄的教师之间外,普教与特教之间的一般教育效能感也存在明显差异(P<0.05～0.01),普教低于特教。同时,女教师之间的个人教学效能感存在着显著差异,普教女教师高于特教女教师。③相关性:普教与特教教师的教学效能感与职业倦怠都呈明显负相关(r=-0.515,-0.502,P<0.01),但特教在情感衰竭维度上的相关性不如普教强(r=-0.320,-0.240,P<0.01,0.05)。④逐步回归分析结果:一般教育效能感对普教的情感衰竭和去人性化程度、对特教教师的低成就感预测性较强(Beta=-0.321,-0.274,-0.404,P<0.01);个人教学效能感同时预测着普教和特教的去人性化和低成就感(普教:Beta=-0.286,-0.360,P<0.01;特教:Beta=-0.480,-0.585,P<0.01)。是否班主任因素对普教教师的情感衰竭和去人性化预测作用明显(Beta=-0.283,-0.179,P<0.01,0.05),而教龄对特教教师的去人性化和低成就感的预测作用明显(Beta=0.258,0.212,P<0.05)。结论:①普教与特教教师的职业倦怠感中的情感衰竭维度和教学效能感中的一般教育效能感有明显差别。②普教与特教教师的职业倦怠感和教学效能感存在性别、教龄及是否班主任的差别。③教学效能感在普教与特教教师中对职业倦怠各因素的预测作用不尽相同。是否班主任因素对普教教师的情感衰竭和去人性化预测作用明显,而教龄对特教教师的去人性化和低成就感的预测作用明显。     

Vascular complications of prolonged intra-aortic balloon counterpulsation in cardiac surgical patients

Background. Use of intra-aortic balloon pump (IABP) is associated with certain vascular complications, which are likely to develop more frequently in patients where IABP is used for prolonged period. The present study was undertaken to analyze vascular complications after prolonged IABP use in patients undergoing various cardiac surgical procedures. Methods. Between January 1995 and February 2001, a total of 1130 patients (7.4% of all adult patients undergoing cardiac procedures) required IABP counterpulsation, out of which 220 patients required IABP for more than 4 days. The vascular complications in these patients were studied. The IABP was inserted by percutaneous technique in 211 (95.5%) patients. The mean age of the patients was 57.5±9.5 years and 15% patients were female. The prevalence of peripheral vascular disease was 11.8%. Results. The duration of IABP therapy ranged from 5 days to 21 days with mean duration of 9.71±4.29 days. A total of 41 complications developed in 38 (17.3%) patients. Acute lower limb ischemia, requiring urgent surgical intervention, was the commonest major complication, which developed in 17 patients. This required thromboembolectomy in 11 patients and femoro-femoral bypass in 3 patients. One patient developed gangrene of the leg, requiring below knee amputation. On multivariate analysis, peripheral vascular disease, preoperative serum creatinine, surgery for LV aneurysm and unstable angina and hemodynamic instability (as the indications for IABP) were found as the predictors of vascular complications. Conclusions. Prolonged use of IABP counterpulsation is associated with significant incidence of vascular complications. Proper assessment of peripheral circulation before IABP insertion and appropriate management of ischemic complications are important to avoid limb loss to the patient.     

Postamputation neuromas and other symptomatic stump abnormalities: detection with CT

One of the potentially troublesome sequelae of limb amputations is the development of stump neuromas at the severed ends of major nerves. The ability to define them and to distinguish them from other causes of stump pain is of considerable clinical significance. Computed tomography was performed on ten lower limb amputees with stump pain. Five patients had neuromas that were manifest as focal or generalized alteration in the caliber, size, or contour of the nerve trunk in the affected stump. The remaining five patients each had an abnormality detected; these abnormalities included heterotopic bone formation, popliteal artery aneurysm, lipoma, scar tissue, and abscess in the contralateral limb.     

Age-estimations of rats based on the average lateral diffusion constant of hepatocyte membrane proteins as revealed by fluorescence recovery after photobleaching

A method has been developed recently for measuring the average lateral diffusion constant of the proteins (D) in the cell membrane of hepatocytes in liver smears by fluorescence recovery after photobleaching (FRAP). A peroxide-induced autofluorescence (PIAF) of the membrane proteins was used as a fluorescent label. It has been established that D displays a significant negative linear correlation with age. The present paper describes age-estimations carried out on 12 male Fischer 344 rats (7–29 months of age) in so-called “blind experiments”: the operator knew only the sex of the rat, determined D from a small piece of the freshly removed liver, and estimated the age of the rat from the age-dependent regression line for D established previously on 16 other Fischer 344 male rats of various ages. There was a strong correlation of the estimated age with the actual one (r = 0.92), the slope of the regression line was 0.98 and its intercept differed from 0 by only 0.5 months. These results indicate that D may play a decisive role in the determination of membrane functions as predicted by the membrane hypothesis of aging.