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.     

中药肾区渗透并常规治疗高血压性肾损害40例疗效观察

目的：观察中药肾区皮肤外敷渗透加西药常规治疗高血压肾损害结果。方法：将部分中药粉碎微细化处理，将另部分中药液化处理．粉液混合装袋醋浸后外敷在肾区皮肤上，用药物导入仪肾区靶点式导人人体。并用一般西医常规治疗。结果：平均治疗3周血肌酐下降23％，BUN下降26％，24h蛋白尿下降23％，尿量增加16％，收缩压下降9％，舒张压下降7％。结论：中药的肾区皮肤外敷渗透加西医常规治疗效果明显高于一般常规治疗。     

HBV转录激活蛋白HBx、MHBst78MHBst155真核重组载体构建

目的分别构建人乙型肝炎病毒(HBV)X蛋白、羧基端截断的中分子表面蛋白MHBst78、MHBst155编码基因的真核重组表达载体,以便进一步研究其转录激活功能及对宿主细胞信号传导通路的影响。方法设计合成3对寡核苷酸引物,以adr亚型HBV质粒pHBVDNA为模板,采用PCR法分别扩增HBVX基因、MHBst78与MHBst155编码基因片段;用HindⅢ,KpnⅠ双酶切HBVⅩ基因;用HindⅢ和BamHⅠ双酶切MHBst78与MHBst155编码基因片段后,分别定向插入到真核表达载体pcDNA3.1相应酶切位点,转化宿主菌JM109,提取质粒,分别用上述内切酶酶切及DNA测序鉴定重组质粒。结果酶切重组体显示所切下的片段大小均与预计相符,测序结果与文献报道序列及预计结果一致。结论成功构建了HBVX基因、羧基端截断的HBV中分子表面蛋白MHBst78、MHBst155编码基因的真核重组表达载体,为进一步研究HBV转录激活蛋白HBx、MHBst78MHBst155对宿主细胞信号转导通路的影响奠定基础。     

荧光示踪法研究逆行岛状皮瓣静脉回流

目的探讨采用荧光示踪法研究逆行岛状皮瓣静脉回流的可行性，并初步观察静脉回流规律。方法20只新西兰大白兔，每只取耳静脉血0．ImL，分离RBC并用FITC标记。流式细胞仪检测已标记的RBC阳性率及荧光强度，倒置荧光显微镜观察其形态。取20只新西兰大白兔，在动物双侧后肢内侧分别建立4cm×3cm隐动、静脉逆行岛状皮瓣模型（n=10）和顺行岛状皮瓣模型（n=10），血管蒂长3cm。将一侧后肢随机设定为实验组，皮瓣制备后注射已标记的RBC悬液5pL；对侧为对照组，不注射示踪剂。实验组按顺行和逆行皮瓣分成两组，即顺行皮瓣组和逆行皮瓣组，每组10个；再根据注入示踪剂途径不同，分为动脉和静脉2个亚组，每亚组5个皮瓣。注射示踪剂5S后取下皮瓣立即冷冻，取连续的3张冰冻切片（5～7pm），其中2张行HE染色和GENMED染色，另]张不染色直接压片，荧光显微镜观察荧光分布。结果流式细胞仪分析FITC标记的RBC阳性率在99％以上，荧光强度均≥10。；倒置荧光显微镜下标记的RBC呈均匀分布的绿色荧光，荧光强度均匀、稳定。冰冻切片显示实验组皮瓣蒂部均出现荧光，对照组未见荧光。顺行岛状皮瓣组荧光主要分布在静脉腔、静脉壁、动脉内膜和外膜；逆行岛状皮瓣组荧光分布在动脉内膜、外膜和静脉壁。结论荧光示踪剂可用于静脉回流研究，顺行岛状皮瓣静脉主要通过静脉腔、静脉壁、动脉内膜和外膜回流；逆行岛状皮瓣静脉主要通过动脉内膜、外膜和静脉壁的“迷宫式途径”回流。     

~99m锝-葡聚糖淋巴系统显像剂研制及其初步临床应用

作者采用沉淀法对药用葡聚糖进行分级纯化,通过家兔实验筛选出合乎淋巴系统定向要求分子量(105000)的葡聚糖,并制成一步标记法的亚锡葡聚糖药盒,4℃贮存8个月,标记率大于95％。~(99)m锝-葡聚糖的体内外稳定性均佳。家兔研究表明:(1)淋巴结内聚集量最高,其他非靶器(除肝脏、肾脏外)均处于极低水平;(2)显像速度快、图像清晰,既显示淋巴结又显示淋巴管;(3)注射部位清除速度快,6.5h清除95％。安全试验表明:~(99)m锝-葡聚糖是一种毒性极低、非常安全的药物。临床试用100余例,均获满意图像,检查全过程1h内完成,检查结果与诊断基本相符,故~(99)m锝-葡聚糖是目前临床上比较理想的淋巴系统显像剂,可进一步推广应用。     

小切口胆囊切除术中胆道损伤的预防

目的探讨预防小切口胆囊切除术（MC）中胆道损伤的方法。方法对本组15131例MC中发生的18例胆道损伤进行回顾分析。结果1994年12月前施行MC2321例，发生胆道损伤9例（0．39％），1995年以来实施MC12810例，发生胆道损伤9例（0．07％）。结论思想上高度重视、规范手术适应证、规范手术操作是预防MC中胆道损伤的关键。     

Effect of naloxone on detrusor-sphincter dyssynergia in the chronic spinal cat

Naloxone, an opioid peptide antagonist, has been reported to facilitate voiding in neurologic bladder disorders, but its effects on the neural micturition reflex arc are poorly understood. We studied the effect of naloxone in 34 male adult cats, spinalized at C5-C6 level 7 to 119 days previously. Each cat served as its own control. The following tests were performed: Urethral pressure profiles, cystosphincterograms with the urethro-vesical junction opened and closed and mechanograms of the detrusor, and the circular and longitudinal urethral muscles. The study included (1) the effects of anesthesia of the bladder and pelvic nerve, as well as that of the urethral and pudendal nerves; (2) the action of naloxone; and (3) the action of oxymorphone. Our results demonstrated that naloxone (1) increased somatic (osteotendinous and nociceptive) reflexes and aggravated spasticity; (2) increased vegetative micturitional and sexual reflexes, in particular the urethra-urethral contraction reflex, aggravating the spasmodic contractions of the external sphincter; and (3) increased the frequency and intensity of the mass reflex. In consequence, we suggest that naloxone is contraindicated in cases of spinal cord lesions with detrusor-sphincter dyssynergia syndrome.     

Vitamin E biokinetics, oxidative stress and cigarette smoking.

Vitamin E is comprised of four tocopherols and four tocotrienols, and functions as a lipophilic chain-breaking antioxidant that prevents lipid peroxidation. Although it is well recognized that cigarette smoke is source of oxidative stress, relatively little is known regarding how oxidative stress alters vitamin E utilization in humans. Therefore, this review will highlight the recent knowledge regarding how cigarette smoking alters vitamin E (as alpha- and gamma-tocopherols) utilization in humans. Specifically, we will discuss the mechanisms by which cigarette smoking increases the turnover of plasma vitamin E, decreases the P450-mediated metabolism of vitamin E, and increases the nitration of gamma-tocopherol to result in the formation of 5-nitro-gamma-tocopherol. In addition, the interrelationship between oxidative stress and vitamin C will also be emphasized as it relates to vitamin E utilization.