Working‐correlation‐structure identification in generalized estimating equations

Selecting an appropriate working correlation structure is pertinent to clustered data analysis using generalized estimating equations (GEE) because an inappropriate choice will lead to inefficient parameter estimation. We investigate the well‐known criterion of QIC for selecting a working correlation structure, and have found that performance of the QIC is deteriorated by a term that is theoretically independent of the correlation structures but has to be estimated with an error. This leads us to propose a correlation information criterion (CIC) that substantially improves the QIC performance. Extensive simulation studies indicate that the CIC has remarkable improvement in selecting the correct correlation structures. We also illustrate our findings using a data set from the Madras Longitudinal Schizophrenia Study. Copyright © 2008 John Wiley & Sons, Ltd.     

改良低压回肠代膀胱术的疗效评价

目的 总结改良原位低压回肠代膀胱术的疗效及患者生活质量。方法 膀胱癌患者53例，平均年龄61岁，均施行根治性膀胱全切术。截取末端35—45cm回肠，“U”形缝合形成代“膀胱”，并与输尿管形成抗返流的“乳头”缝合。结果 术后所有患者血生化及电解质均正常，随访3—6个月，51例患者白天完全可控排尿，完全夜间可控制排尿25例。47例无残余尿，5例有残余尿20-35mL。结论 改良低压回肠代膀胱术，膀胱容量大、压力低、无返流、效果好、无吸收性酸中毒，患者白天均能够控制尿液，夜间需定时排尿，生活质量高，多数患者满意。     

Biochemical analysis of human milk treated with sodium dodecyl sulfate, an alkyl sulfate microbicide that inactivates human immunodeficiency virus type 1.

Reduction of transmission of human immunodeficiency virus type 1 (HIV-1) through human milk is needed. Alkyl sulfates such as sodium dodecyl sulfate (SDS) are microbicidal against HIV-1 at low concentrations, have little to no toxicity, and are inexpensive. The authors have reported that treatment of HIV-1-infected human milk with < or = 1% (10 mg/mL) SDS for 10 minutes inactivates cell-free and cell-associated virus. The SDS can be removed with a commercially available resin after treatment without recovery of viral infectivity. In this article, the authors report results of selective biochemical analyses (ie, protein, immunoglobulins, lipids, cells, and electrolytes) of human milk subjected to SDS treatment and removal. The SDS treatment or removal had no significant effects on the milk components studied. Therefore, the use of alkyl sulfate microbicides to treat milk from HIV-1-positive women may be a simple, practical, and nutritionally sound way to prevent or reduce transmission of HIV-1 while still feeding with mother's own milk.     

Modified Nile red staining method for improved visualization of neutral lipid depositions in stratum corneum.

The neutral lipids existing in the intercellular spaces of the stratum corneum (SC) provide a permeability barrier to prevent water loss. Nile red is the most sensitive lipid stain for tissue sections. However, due to the extremely flattened morphology of corneocytes and the resolution limits of the light microscope, Nile red staining is seldom used as a fluorescent probe for the lipid-rich SC. In this study, we modified the traditional method for visualization of intracellular lipid by adding 4% potassium hydroxide after Nile red staining. This modified method not only allowed visualization of lipids existing in the intercellular membrane regions and the lateral junctions of the adjoining corneocytes, but also clearly demonstrated small lipid droplets within pathological corneocytes. These features were not observed with the traditional staining method. Thus, this modified Nile red staining method greatly improved the resolution of the SC lipids under light microscopy and should be useful for studying lipid depositions in both normal and pathological SC.     

高频电铲在腹腔镜直肠癌保肛手术中的临床应用

目的评价腹腔镜直肠癌保肛手术中应用高频电铲的可行性和安全性。方法选取2005年3月至2007年5月间使用高频电铲成功进行腹腔镜保肛手术的直肠癌患者28例，分别对患者术中出血量、手术时间、术后盆腔引流量、肛门排气时间、疼痛程度以及手术并发症等指标进行观察和记录。结果手术时间（178．6±25．3）min、术中出血量（62．6±40．5）ml、术后盆腔引流量：术后1d（90．5±27．1）ml、术后3d（5．4±4．6）ml、肛门排气时间（33．0±5．4）h、疼痛程度（VAS）：术后1d（5．52±1．29）、术后3d（2．42±1．06）、吻合口瘘1例、切口感染1例。随访1～26月无肿瘤复发及肠梗阻患者。结论高频电铲是一种非常实用的工具，应用于腹腔镜直肠癌保肛手术是安全可行的，并可以降低医疗费用。