肺癌胸腔镜术后肺部感染的危险因素探讨及术前CRP/Alb、PCT、SAA对感染风险的预测价值

摘要 目的：分析肺癌胸腔镜术后肺部感染的危险因素并探讨术前C反应蛋白/白蛋白比值（CRP/Alb）、降钙素原（PCT）、血清淀粉样蛋白A（SAA）对感染风险的预测价值。方法：选取2019年3月～2021年10月在徐州医科大学附属医院接受胸腔镜手术治疗的360例肺癌患者,根据肺癌胸腔镜术后72 h是否发生肺部感染分为肺部感染组57例和非肺部感染组303例。收集患者临床资料,术前1d检测患者血清CRP/Alb、PCT、SAA水平。通过单因素和多因素Logistic回归分析肺癌胸腔镜术后肺部感染的危险因素,受试者工作特征（ROC）曲线分析术前血清CRP/Alb、PCT、SAA水平对肺癌胸腔镜术后肺部感染的预测价值。结果：单因素分析显示,肺部感染组年龄≥60岁、吸烟史、糖尿病、手术时间≥3 h、术中出血量≥200 mL、机械通气时间≥12 h、胸腔引流时间≥5 d比例和血清CRP/Alb、PCT、SAA水平高于非肺部感染组（P＜0.05）。多因素Logistic回归分析显示,年龄≥60岁、吸烟史、糖尿病、手术时间≥3 h、机械通气时间≥12 h、胸腔引流时间≥5 d和血清CRP/Alb、PCT、SAA升高为肺癌胸腔镜术后肺部感染的独立危险因素（P＜0.05）。ROC曲线分析显示,术前血清CRP/Alb、PCT、SAA水平联合预测肺癌胸腔镜术后肺部感染的曲线下面积大于各指标单独预测。结论：年龄、吸烟史、糖尿病、手术时间、机械通气时间、胸腔引流时间和CRP/Alb、PCT、SAA升高为肺癌胸腔镜术后肺部感染的危险因素,术前血清CRP/Alb、PCT、SAA联合预测肺癌胸腔镜术后肺部感染的价值较高。     

急性阑尾炎患者术后切口感染的病原菌分析及NLR、PCT、CRP联合检测的预测价值研究

摘要 目的：分析急性阑尾炎（AA）患者术后切口感染的病原菌并探讨中性粒细胞与淋巴细胞比值（NLR）、降钙素原（PCT）、C反应蛋白（CRP）联合检测的预测价值。方法：选取2020年1月～2022年9月青岛大学附属医院收治的379例接受腹腔镜或开腹手术的AA患者,根据是否发生术后切口感染分为感染组和非感染组,收集AA患者临床资料并检测NLR、PCT、CRP水平。分析术后切口感染AA患者病原菌分布情况,采用单因素和多因素Logistic回归分析AA患者术后切口感染的影响因素,采用受试者工作特征（ROC）曲线分析NLR、PCT、CRP对AA患者术后切口感染的预测价值。结果：379例AA患者术后切口感染发生率为12.40%（47/379）,47例术后切口感染AA患者切口分泌物共检测出75株病原菌,革兰氏阳性菌和革兰氏阴性菌分别占比42.67%（32/75）、57.33%（43/75）。感染组NLR、PCT、CRP水平高于非感染组（P＜0.05）。多因素Logistic回归分析显示,年龄≥60岁、病程≥24 h、阑尾化脓或坏疽及穿孔、开腹手术、留置引流管和血清NLR、PCT、CRP升高为AA患者术后切口感染的独立危险因素,预防性应用抗菌药物为其独立保护因素（P＜0.05）。ROC曲线分析显示,NLR、PCT、CRP联合预测AA患者术后切口感染的曲线下面积大于NLR、PCT、CRP单独预测。结论：术后切口感染AA患者病原菌以革兰氏阴性菌为主,术前NLR、PCT、CRP水平升高与AA患者术后切口感染密切相关,三者联合预测AA患者术后切口感染的价值较高。     

妊娠期糖尿病患者剖宫产术后切口感染的影响因素及血清降钙素原、糖化血红蛋白对感染风险的预测价值研究

摘要 目的：分析妊娠期糖尿病（GDM）患者剖宫产术后切口感染的影响因素并探讨血清降钙素原（PCT）、糖化血红蛋白（HbA1c）对感染风险的预测价值。方法：选取2020年1月～2022年1月我院收治的253例行剖宫产术的GDM患者,根据剖宫产术后是否发生切口感染分为感染组和非感染组。检测血清PCT、HbA1c水平,采用单因素和多因素Logistic回归分析GDM患者剖宫产术后切口感染的影响因素,受试者工作特征（ROC）曲线分析血清PCT和HbA1c对GDM患者剖宫产术后切口感染的预测价值。结果：253例GDM患者剖宫产术后切口感染发生率为15.02％（38/253）。单因素分析显示,感染组年龄≥35岁、手术时间≥1 h、术中出血量≥500 mL、肛检/阴检≥3次、羊水污染、胎膜早破、生殖道炎症比例和PCT、HbA1c高于非感染组,预防性使用抗菌药物比例低于非感染组（P均＜0.05）。多因素Logistic回归分析显示,手术时间≥1 h、肛检/阴检≥3次、羊水污染、胎膜早破、生殖道炎症、PCT升高、HbA1c升高为GDM患者剖宫产术后切口感染的独立危险因素（P＜0.05）,预防性使用抗菌药物为其独立保护因素（P＜0.05）。ROC曲线分析显示,血清PCT和HbA1c单独与联合预测GDM患者剖宫产术后切口感染的曲线下面积分别为0.797、0.774、0.875。结论：手术时间、预防性使用抗菌药物、肛检/阴检、羊水污染、胎膜早破、生殖道炎症、PCT和HbA1c为GDM患者剖宫产术后切口感染的影响因素,术前血清PCT和HbA1c联合预测剖宫产术后切口感染的价值较高。     

乳腺癌化疗患者外周静脉置入中心静脉导管置管感染的危险因素分析及其生活质量调查

摘要 目的：分析乳腺癌化疗患者外周静脉置入中心静脉导管（PICC）置管感染的危险因素,并观察其生活质量。方法：选择2019年1月~2020年10月期间来我院接受诊治的198例乳腺癌患者,搜集所有患者的一般资料,观察其PICC置管感染情况,采用多因素Logistic回归分析PICC置管感染的危险因素。采用生活质量量表(QLQ-C30)评价所有患者的生活质量。结果：198例患者中有17例发生PICC置管感染,感染率为8.59%。根据感染情况将所有患者分为感染组（n=17）和未感染组（n=181）。单因素分析结果显示,PICC置管感染与年龄、穿刺次数、穿刺部位无关（P>0.05）,而与合并基础疾病、乳腺癌分期、留置季节、置管时间、化疗次数、换药天数、白细胞计数有关（P<0.05）。经 Logistic 回归分析显示：白细胞计数>4×10⁹/L、置管时间>10个月、留置季节为夏季、化疗次数≥4次、合并基础疾病、换药天数>7 d是影响 PICC 置管局部感染的独立危险因素（P<0.05）。未感染组的功能领域、总体健康状况、总分高于感染组,症状领域评分低于感染组（P<0.05）。结论：乳腺癌化疗患者具有一定的PICC置管感染率,且感染的患者其生活质量明显下降,引起感染的因素较多,与化疗次数、置管时间、白细胞计数、合并基础疾病、换药天数、留置季节有关,临床上需予以充分重视,以尽可能减少 PICC 局部感染现象的发生。     

血清乳酸脱氢酶评估颅脑手术患者重症肺炎的临床价值

摘要 目的：分析血清乳酸脱氢酶在评估颅脑手术患者重症肺炎的中的应用价值。方法：选取2020年7月~2022年6月在本院神经外科进行收治的颅脑择期手术患者268例,根据是否合并术后肺炎,分为非感染组（n=185）和肺炎组（n=83）,肺炎组根据肺炎严重程度分为重症肺炎31例及普通肺炎52例。采用酶联免疫吸附法测定血清PCT、CRP水平;采用酶比色法检测血清 LDH 水平,采用Pearson相关性检验分析合并肺炎患者血清LDH、PCT、CRP水平与病情严重程度的相关性。采用ROC曲线分析血清LDH、PCT、CRP水平对颅脑手术患者合并重症肺炎的临床诊断价值,血清LDH、PCT、CRP水平预估颅脑手术合并重症肺炎患者预后的价值。结果：术后1 d、3 d、7 d与未感染组对比,普通肺炎组患者血清LDH、PCT、CRP水平均明显升高（P<0.05）;与普通肺炎组对比,重症肺炎组患者血清LDH、PCT、CRP水平均明显升高（P<0.05）。经Pearson相关性检验分析,颅脑手术合并肺炎患者血清LDH、PCT、CRP水平与PSI评分呈明显正相关（P<0.05）。以术后1 d血清LDH、PCT、CRP水平建立ROC曲线,结果发现,血清LDH、PCT、CRP的曲线下面积分别为0.840、0.825、0.746。以术后7 d血清LDH、PCT、CRP水平建立ROC曲线,结果发现,血清LDH、PCT、CRP的曲线下面积分别为0.819、0.725、0.684。结论：LDH在颅脑手术合并肺炎患者中高表达,与肺炎严重程度正相关。LDH在区分非重症肺炎患者和重症肺炎患者以及预测重症肺炎患者的28天死亡率方面具有良好价值。     

血清sTM、PCT、CRP/PAB比值与脓毒症患者APACHEⅡ评分、SOFA评分的相关性及其联合检测对预后的预测价值

摘要 目的：探讨血清可溶性血栓调节蛋白（sTM）、降钙素原（PCT）、C-反应蛋白与前白蛋白（CRP/PAB）比值与脓毒症患者急性生理和慢性健康评估Ⅱ（APACHEⅡ）评分、序贯器官衰竭评估（SOFA）评分的相关性及其联合检测对预后的预测价值。方法：选取2020年3月～2020年12月我院重症医学科收治的97例脓毒症患者,根据Sepsis-3.0诊断标准分为普通脓毒症组44例、脓毒性休克组53例,根据入院后30 d内预后情况分为死亡组35例和存活组62例。收集患者基线资料和APACHEⅡ评分、SOFA评分,并检测血清sTM、PCT、CRP/PAB比值。采用Spearman相关性分析脓毒症患者血清sTM、PCT、CRP/PAB比值与APACHEⅡ评分、SOFA评分的相关性,多因素Logistic回归分析脓毒症患者预后不良的影响因素,受试者工作特征（ROC）曲线分析血清sTM、PCT、CRP/PAB比值对脓毒症患者预后不良的预测价值。结果：脓毒性休克组血清sTM、PCT、CRP/PAB比值和APACHEⅡ评分、SOFA评分高于普通脓毒症组（P均＜0.05）。Spearman相关性分析显示,脓毒症患者血清sTM、PCT、CRP/PAB比值与APACHEⅡ评分、SOFA评分呈正相关（P＜0.05）。多因素Logistic回归分析显示,收缩压升高为脓毒症患者预后不良的独立保护因素（P＜0.05）,脓毒性休克、合并器官损伤≥3个、机械通气时间延长、APACHEⅡ评分增加、SOFA评分增加、sTM升高、PCT升高、CRP/PAB比值升高为独立危险因素（P均＜0.05）。ROC曲线分析显示,血清sTM、PCT、CRP/PAB比值联合预测脓毒症患者预后不良的曲线下面积大于各指标单独预测。结论：脓毒症患者血清sTM、PCT、CRP/PAB比值升高与APACHEⅡ评分、SOFA评分增加密切相关,血清sTM、PCT、CRP/PAB比值联合检测对脓毒症患者预后不良的预测价值较高。     

血清降钙素原、C反应蛋白/白蛋白比值联合尿白细胞酯酶对复杂性肾结石患者经皮肾镜碎石术后发生尿路感染的预测价值分析

摘要 目的：探讨血清降钙素原（PCT）、C反应蛋白（CRP）/白蛋白（ALB）比值联合尿白细胞酯酶（LEU）对复杂性肾结石患者经皮肾镜碎石术（PCNL）后发生尿路感染的预测价值。方法：选择2015年3月-2021年6月我院收治的128例行PCNL的复杂性肾结石患者作为观察对象,术后定期随访,统计尿路感染情况,根据是否发生术后尿路感染分为尿路感染组和非尿路感染组。比较两组PCT水平、LEU,CRP/ALB比值及其他临床资料。采用多因素Logistic回归分析术后尿路感染的危险因素,绘制受试者工作特征（ROC）曲线,分析PCT、CRP/ALB比值、LEU单独以及联合检测预测术后尿路感染的价值。结果：尿路感染组的血清PCT、CRP/ALB高于非尿路感染组（P<0.05）。尿路感染组的LEU呈阳性,而非尿路感染组的LEU呈阴性。两组在既往泌尿道手术史、手术时间、导尿管留置时间、住院时间、术前尿路感染、结石负荷、使用>3种抗菌药物、合并肾功能障碍、术中通道类型、术前血糖水平方面对比有统计学差异（P<0.05）。既往泌尿道手术史、手术时间≧100 min、导尿管留置时间≧7 d、术前尿路感染、结石负荷≧1000 mm2、术前血糖水平高、合并肾功能障碍是复杂性肾结石患者PCNL后发生尿路感染的危险因素（P<0.05）。PCT、CRP/ALB、LEU单独预测PCNL后尿路感染的曲线下面积（AUC）分别为0.712（0.476～0.944）、0.686（0.436～0.931）、0.836（0.753～0.918）,三者联合预测PCNL后尿路感染的AUC为0.879（0.785～0.972）,均高于PCT、CRP/ALB、LEU单独预测。结论：复杂性肾结石患者PCNL后发生尿路感染的影响因素较多,包括导尿管留置时间、住院时间、结石负荷等,且PCNL后发生尿路感染患者PCT、CRP/ALB比值偏高,LEU呈阳性,三者可能作为PCNL后发生尿路感染的生物标记物。     

Stanford A型主动脉夹层孙氏手术患者术后血流感染的影响因素及术前PCT、IL-6、D-D的预测价值研究

摘要 目的：分析Stanford A型主动脉夹层（AD）孙氏手术患者术后血流感染（BSI）的影响因素,并探讨术前血清降钙素原（PCT）、白细胞介素-6（IL-6）、D-二聚体（D-D）对术后发生BSI的预测价值。方法：选取2019年1月～2022年1月贵州医科大学附属医院收治的236例接受孙氏手术的Stanford A型AD患者,根据术后是否BSI分为BSI组和非BSI组。收集患者基础资料和实验室指标,采用多因素Logistic回归分析Stanford A型AD孙氏手术患者术后发生BSI的影响因素,采用受试者工作特征（ROC）曲线分析血清PCT、IL-6、D-D水平对Stanford A型AD孙氏手术患者术后发生BSI的预测价值。结果：BSI组年龄≥60岁、糖尿病史、机械通气、气管切开、人工瓣膜植入比例和术后24 h引流量、血清C反应蛋白、PCT、IL-6、D-D水平高于非BSI组,手术时间、心包纵隔管保留时间长于非BSI组（P＜0.05）。多因素Logistic回归分析显示,年龄≥60岁、糖尿病史、机械通气、气管切开、术后24 h引流量上升,血清PCT、IL-6、D-D水平上升为Stanford A型AD孙氏手术患者术后发生BSI的危险因素（P＜0.05）。ROC曲线分析显示,血清PCT、IL-6、D-D三项联合预测的Stanford A型AD孙氏手术患者术后发生BSI的曲线下面积大于单独预测。结论：年龄、糖尿病史、机械通气、气管切开、术后24 h引流量、血清PCT、IL-6、D-D水平是Stanford A型AD孙氏手术患者术后发生BSI的影响因素,术前血清PCT、IL-6、D-D水平可作为Stanford A型AD孙氏手术患者术后发生BSI的辅助预测指标。     

血清PCT、sICAM-1联合HMGB1预测急性阑尾炎患儿手术切口感染风险的临床研究

摘要 目的：探讨血清降钙素原（PCT）、可溶性细胞间粘附分子-1（sICAM-1）联合高迁移率族蛋白B1（HMGB1）预测急性阑尾炎（AA）患儿手术切口感染风险的价值。方法：前瞻性选取2020年1月～2022年7月四川大学华西医院小儿外科收治的536例接受腹腔镜手术的AA患儿,根据术后是否发生手术切口感染分为感染组和未感染组。采用酶联免疫吸附法检测血清PCT、sICAM-1、HMGB1水平。采用多因素Logistic回归分析AA患儿手术切口感染的影响因素,采用受试者工作特征（ROC）曲线分析血清PCT、sICAM-1、HMGB1水平对AA患儿手术切口感染的预测价值。结果：536例AA患儿腹腔镜手术后手术切口感染发生率为11.94%（64/536）。与未感染组比较,感染组血清PCT、sICAM-1、HMGB1水平升高（P＜0.05）。多因素Logistic回归分析显示,病程＞24 h、阑尾穿孔、手术操作时间＞60 min、留置腹腔引流和PCT、sICAM-1、HMGB1水平升高为AA患儿手术切口感染的独立危险因素（P＜0.05）。ROC曲线分析显示,血清PCT、sICAM-1联合HMGB1预测AA患儿手术切口感染的曲线下面积（AUC）大于PCT、sICAM-1、HMGB1单独预测。结论：血清PCT、sICAM-1、HMGB1水平升高与AA患儿手术切口感染密切相关,血清PCT、sICAM-1联合HMGB1预测AA患儿手术切口感染的价值较高,可能成为AA患儿手术切口感染的辅助预测指标。     

术前降钙素原、血红蛋白、中性粒细胞与淋巴细胞比值与永久性心脏起搏器植入患者术后囊袋感染的关系研究

摘要 目的：探讨术前降钙素原（PCT）、血红蛋白（Hb）、中性粒细胞与淋巴细胞比值（NLR）与永久性心脏起搏器植入（PPI）患者术后囊袋感染的关系。方法：回顾性选取2019年7月～2021年7月安徽医科大学第二附属医院收治的400例PPI患者,根据术后1年是否发生囊袋感染分为感染组和非感染组。收集患者临床资料和术前PCT、Hb、NLR水平。采用单因素和多因素Logistic回归分析PPI患者术后囊袋感染的影响因素,采用受试者工作特征（ROC）曲线分析术前PCT、Hb、NLR对PPI患者术后囊袋感染的预测价值。结果：随访1年,400例PPI患者术后囊袋感染发生率为8.00%（32/400）。多因素Logistic回归分析显示,年龄增加、糖尿病、起搏器更换/升级、术后囊袋血肿和PCT、NLR升高、Hb降低为PPI患者术后囊袋感染的独立危险因素（P＜0.05）。ROC曲线分析显示,术前PCT、Hb、NLR联合预测PPI患者术后囊袋感染的曲线下面积大于PCT、Hb、NLR单独预测。结论：术前PCT、NLR升高和Hb降低与PPI患者术后囊袋感染有关,术前PCT、Hb、NLR联合预测术后囊袋感染的价值较高。     

Anthropology and genetics of the caucasus peoples and the problem of the origin of the caucasoids

The electrophoretical polymorphisms of some blood proteins were studied in the Talysh population of Pirasora situated in South-East Azerbaidjan. We calculated the gene frequencies of these polymorphisms and determined the genetic distances between the Talyshes and some Iranian populations of North, Central and South Iran, Afghans, and three populations of Azerbaijan. The Talyshes are very close to Iranians of Shiraz, whereas they are distant from the Azerbaijanians. Anthropological investigations showed that the Caucasoids and Mongoloids lived in the Aragvi Basin since the Eneolithic period. This was stated by Alexeev (1974), who emphasized the mixture of the Caucasus populations from ancient times on. We calculated the genetic distances between the Caucasus populations and numerous populations of other geographic regions, considering 28 alleles of 12 loci of blood group, serum protein and red cell enzyme polymorphisms and constructed the dendrogram of these populations. The position of the Caucasus populations in the dendrogram corresponds on principle to the earlier anthropological observations. The clustering of the Caucasoid populations corresponds completely with anthropological and historical data, and supports our earlier hypothesis (Nazarova 1999) concerning the differentiation of Caucasoids, Northern Mongoloids and Amerinds from the populations, which inhabitated Asia in palaeolithic times.     

人类基因组及后基因组研究进展及其应用与开发研究现状

人类对自身基因组的研究,随着人类基因组工作草图的绘制完成和对基因功能研究的深入已加快进入了实质性、关键性的开发利用阶段。本文概述了人类基因组及后基因组的研究进展及依此开展基因治疗及基因（组）药物研制等应用开发研究的现状。     

Serology and systematics of the Ebenales and the Theales

The systematic position ofthe Ebenaceae, Sapotaceae, Styracaceae, Ochnaceae, Stachyuraceae, Dipterocarpaceae, Clusiaceae and Hypericaceae has been investigated using serological comparisons of sets of antigenic determinants. The results show that the Sytracaceae and Sapotaceae are undoubtedly more closely associated with the Actinidiaeceae and Theaceae, respectively, than with each other. We found no corresponding determinants betnween antigen systems from the Ebenaceae and systems from any other family whose relations to this family have been proposed. As discovered previously, investigations of antigen systems from the Ochnaceae, Dipterocarpaceae, Stachyuraceae, Clusiaceae and Hypericaceae are against the idea of a natural order “Theales” in which these families, or at least some of them, are combined with the Theaceae and Actinidiaceae. This paper completes our previous investigations which largely support a superorder Ericanae sensu Ehrendorfer and Takhtajan. We propose to include the Actinidiaceae and Theaceae in this superorder, assigning them a central position laong with the Sapotaceae and Sytracaeae on one side and the Primulales and Ericales on the other. Another most interesting finding is that there are corresponding determinants between antigen systems from the members of the Ericanae and representatives of the Polemoniaceae and Loasaceae.     

Kinematics and dynamics of the temporomandibular joint and of the movements of the mandible

In order to analyze the complicated movements of the mandible as the open-closing movement and the protrusio are, it is useful to evaluate the basic kinematic principles and reduce them to simple technical constructions. Both the open-closing movement and the protrusio could be reduced to 4-bar links, which were used to simulate the movements with help of a computer. Besides, the polodes and the curves of points in the muscular attachments could be constructed. The 2 entirely different 4-bar links have 3 things in common: The resting system - cranium, the moving system - mandibula, and 1 of the 2 arms connecting these 2 systems - the ligamentum laterale. As this ligament is taut during movements it can be considered a "guiding ligament" representing 1 of the 3 determining components of the mandibular movements. The other of the 2 arms has no anatomical equivalent; this arm, however, is "replaced" by the 2 other determining components of the mandibular movements: the joint and the muscles. The curves, which the Caput mandibulae describes, are practically identical for the open-closing movement and the protrusio despite of the different 4-bar links and these curves exactly correspond to the Discus articularis, taut by the upper part of the M. pterygoideus lateralis. The muscles do not only just move the mandibula, but they are also the component, which can choose between the different mandibular movements. By means of the curves, which points in the muscular attachments describe, the function of the masticatory muscles could be analyzed exactly.     

On the structure and dynamics of the complex of the nucleosome and the linker histone

Several different models of the linker histone (LH)–nucleosome complex have been proposed, but none of them has unambiguously revealed the position and binding sites of the LH on the nucleosome. Using Brownian dynamics-based docking together with normal mode analysis of the nucleosome to account for the flexibility of two flanking 10 bp long linker DNAs (L-DNA), we identified binding modes of the H5-LH globular domain (GH5) to the nucleosome. For a wide range of nucleosomal conformations with the L-DNA ends less than 65 Å apart, one dominant binding mode was identified for GH5 and found to be consistent with fluorescence recovery after photobleaching (FRAP) experiments. GH5 binds asymmetrically with respect to the nucleosomal dyad axis, fitting between the nucleosomal DNA and one of the L-DNAs. For greater distances between L-DNA ends, docking of GH5 to the L-DNA that is more restrained and less open becomes favored. These results suggest a selection mechanism by which GH5 preferentially binds one of the L-DNAs and thereby affects DNA dynamics and accessibility and contributes to formation of a particular chromatin fiber structure. The two binding modes identified would, respectively, favor a tight zigzag chromatin structure or a loose solenoid chromatin fiber.     

Biophysics and Structure of the Patch and the Gigaseal

Interpreting channel behavior in patches requires an understanding of patch structure and dynamics, especially in studies of mechanosensitive channels. High resolution optical studies show that patch formation occurs via blebbing that disrupts normal membrane structure and redistributes in situ components including ion channels. There is a 1-2 μm region of the seal below the patch where proteins are excluded and this may consist of extracted lipids that form the gigaseal. Patch domes often have complex geometries with inhomogeneous stresses due to the membrane-glass adhesion energy (E_a), cytoskeletal forces, and possible lipid subdomains. The resting tension in the patch dome ranges from 1-4 mN/m, a significant fraction of the lytic tension of a bilayer (∼10 mN/m). Thus, all patch experiments are conducted under substantial, and uneven, resting tension that may alter the kinetics of many channels. E_a seems dominated by van der Waals attraction overlaid with a normally repulsive Coulombic force. High ionic strength pipette saline increased E_a and, surprisingly, increased cytoskeletal rigidity in cell-attached patches. Low pH pipette saline also increased E_a and reduced the seal selectivity for cations, presumably by neutralizing the membrane surface charge. The seal is a negatively charged, cation selective, space with a resistance of ∼7 gigohm/μm in 100 mM KCl, and the high resistivity of the space may result from the presence of high viscosity glycoproteins. Patches creep up the pipette over time with voltage independent and voltage dependent components. Voltage-independent creep is expected from the capillary attraction of E_a and the flow of fresh lipids from the cell. Voltage-dependent creep seems to arise from electroosmosis in the seal. Neutralization of negative charges on the seal membrane with low pH decreased the creep rate and reversed the direction of creep at positive pipette potentials.     

Comparison of the Effects of Flexion and Extension of the Thumb and Fingers on the Position and Cross-Sectional Area of the Median Nerve

Objective

To assess the separate effects of thumb and finger extension/flexion on median nerve position and cross-sectional area.

Methods

Ultrasonography was used to assess median nerve transverse position and cross-sectional area within the carpal tunnel at rest and its movement during volitional flexion of the individual digits of the hand. Both wrists of 165 normal subjects (11 men, 4 women, mean age, 28.6, range, 22 to 38) were studied.

Results

Thumb flexion resulted in transverse movement of the median nerve in radial direction (1.2±0.6 mm), whereas flexion of the fingers produced transverse movement in ulnar direction, which was most pronounced during flexion of the index and middle fingers (3.2±0.9 and 3.1±1.0 mm, respectively). Lesser but still statistically significant movements were noted with flexion of the ring finger (2.0±0.8 mm) and little finger (1.2±0.5 mm). Flexion of the thumb or individual fingers did not change median nerve cross-sectional area (8.5±1.1 mm²).

Conclusions

Volitional flexion of the thumb and individual fingers, particularly the index and middle fingers, produced significant transverse movement of the median nerve within the carpal tunnel but did not alter the cross-sectional area of the nerve. The importance of these findings on the understanding of the pathogenesis of the carpal tunnel syndrome and its treatment remains to be investigated.