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。     

急性Stanford A型主动脉夹层患者术后死亡的危险因素及血清NT-proBNP、D-D联合监测对预后的评估价值

摘要 目的：探讨急性Stanford A型主动脉夹层（ATAAD）患者术后死亡的危险因素,分析血清N-末端B型利钠肽原（NT-proBNP）、D-二聚体（D-D）联合监测在预后评估中的价值。方法：回顾性选择2017年10月至2020年10月我院收治的212例行手术治疗的ATAAD患者,追踪术后30 d生存情况,分为死亡组（36例）和存活组（176例）。收集并比较两组基线、手术和实验室相关资料,多因素Logistic回归分析ATAAD患者术后30 d内死亡的危险因素,受试者工作特征（ROC）曲线分析NT-proBNP、D-D单独及联合预测ATAAD患者术后30 d内死亡的价值。结果：死亡组年龄≥60岁、急性生理与慢性健康状况评估Ⅱ（APACHE Ⅱ）评分、序贯器官功能衰竭（SOFA）评分、血肌酐（Scr）、NT-proBNP、D-D,术前≥2个脏器灌注不良、联合冠脉旁路移植术（CABG）、术后输血、术后并发急性肾损伤、术后并发低心排、持续肾脏替代治疗（CRRT）人数占比,机械通气时间、重症监护病房（ICU）停留时间均高于存活组（P＜0.05）。多因素Logistic回归分析显示术前≥2个脏器灌注不良、术后伴急性肾损伤、联合CABG、术后低心排、NT-proBNP、D-D是影响ATAAD患者术后30 d内死亡的危险因素（P＜0.05）。NT-proBNP、D-D预测ATAAD患者术后30 d内死亡的曲线下面积为0.728、0.720,联合NT-proBNP和D-D的曲线下面积为0.834,高于单独应用NT-proBNP、D-D。结论：术前脏器灌注不良、术后急性肾损伤、联合CABG手术、术后低心排、NT-proBNP、D-D是影响ATAAD患者住院30d内死亡的危险因素,联合NT-proBNP和D-D在ATAAD患者预后评估有较高价值。     

血清TM、P-selectin、HDL-C以及凝血功能指标与创伤性骨折患者术后深静脉血栓形成的关系研究

摘要 目的：探讨血清血栓调节蛋白（TM）、P-选择素（P-selectin）、高密度脂蛋白（HDL-C）以及凝血功能指标与创伤性骨折患者术后深静脉血栓形成（DVT）的关系。方法：选择2018年1月至2020年1月我院收治的术后发生DVT的创伤性骨折患者100例作为DVT组,同期术后未发生DVT的创伤性骨折患者100例作为无DVT组,比较两组血清TM、P-selectin、HDL-C、血浆凝血功能指标[凝血酶时间（TT）、凝血酶原时间（PT）、活化部分凝血酶时间（APTT）、纤维蛋白原（FIB）、D-二聚体（D-D）],应用Pearson相关性分析血清TM、P-selectin、HDL-C与凝血功能指标的相关性,应用多因素Logistic回归分析创伤性骨折患者术后DVT的影响因素。结果：DVT组血清TM、P-selectin、血浆D-D、FIB水平、年龄≥60岁比例高于无DVT组,血清HDL-C水平低于无DVT组（P＜0.05）。DVT组血清TM和P-selectin与血浆D-D、FIB呈正相关（P＜0.05）,血清HDL-C与血浆D-D、FIB呈负相关（P＜0.05）。多因素Logistic回归分析显示,年龄≥60岁、血清TM≥9.50 IU/mL、P-selectin ≥70.00 ng/mL、HDL-C<1.00 mmol/L、血浆D-D≥700.00 μg/L、FIB≥4.00 g/L是创伤性骨折患者术后DVT的危险因素（P＜0.05）。结论：创伤性骨折患者术后发生DVT患者血清TM、P-selectin较无DVT患者升高,HDL-C较无DVT患者降低,联合检测血清TM、P-selectin、HDL-C和凝血功能指标可能有助于降低DVT的发生风险。     

颅内压、颅温及血清D-二聚体、白蛋白预测重型颅脑损伤患者术后短期预后的临床价值研究

摘要 目的：探讨颅内压、颅温及血清D-二聚体（D-D）、白蛋白预测重型颅脑损伤（STBI）患者术后短期预后的临床价值。方法：选取2020年3月～2022年1月我院收治的124例STBI患者,对所有患者均开展颅脑手术治疗,术后3个月按照格拉斯哥结局量表（GOS）评分的差异分为预后不良组（GOS评分≤3分）43例以及预后良好组（GOS评分>3分）81例。记录术后颅内压、颅温及入院时血清D-D、白蛋白水平,采用多因素Logistic回归模型分析STBI患者术后短期预后不良的影响因素。采用受试者工作特征（ROC）曲线分析颅内压、颅温及血清D-D、白蛋白水平预测STBI患者术后短期预后不良的效能。结果：预后不良组术后颅内压及入院时血清D-D水平高于预后良好组,术后颅温以及入院时血清白蛋白水平低于预后良好组（均P＜0.05）。预后不良组年龄大于预后良好组,入院时格拉斯哥昏迷量表（GCS）评分低于预后良好组,多发性损伤、脑疝、高钠血症以及脑干损伤发生率高于预后良好组（均P＜0.05）。多因素Logistic回归分析结果显示：术后颅内压（较高）及入院时血清D-D水平（较高）为STBI患者术后短期预后不良的危险因素（P＜0.05）,术后颅温（较高）以及入院时血清白蛋白水平（较高） 为STBI患者术后短期预后不良的保护因素 （P＜0.05）。ROC曲线分析结果显示：颅内压、颅温及血清D-D、白蛋白水平联合检测预测STBI患者术后短期预后不良的曲线下面积（AUC）、灵敏度、特异度均高于上述四项指标单独检测。结论：术后颅内压、颅温及入院时血清D-D、白蛋白水平均为STBI患者短期预后的影响因素,联合上述四指标预测STBI患者手术治疗后短期预后不良的价值较高。     

术前预后营养指数和血清转铁蛋白与老年髋部骨折患者术后切口愈合的关系及其预测价值分析

摘要 目的：研究术前预后营养指数（PNI）和血清转铁蛋白（TRF）与老年髋部骨折（HF）患者术后切口愈合不良（PWH）的关系及其预测价值。方法：选取2020年1月～2022年3月南京市中医院收治的252例接受手术治疗老年HF患者,根据术后切口愈合情况分为PWH组（n=27）和非PWH组（n=225）。收集患者基础资料、术前PNI和血清TRF水平。采用多因素Logistic回归分析老年HF患者术后PWH的影响因素,受试者工作特征（ROC）曲线分析PNI和血清TRF水平对老年HF患者术后PWH的预测价值。结果：252例老年HF患者术后出现27例PWH,其中24例切口长时间不愈合,3例切口裂开。与非PWH组比较,PWH组体质量指数（BMI）和白蛋白、淋巴细胞计数（LC）、PNI、血清TRF水平更低,糖尿病比例和术中出血量更高（P＜0.05）。多因素Logistic回归分析显示,BMI≥18.5 kg/m²（OR=0.648,95％CI：0.457～0.919）、PNI（OR=0.954,95％CI：0.932～0.976）、血清TRF（OR=0.484,95％CI：0.307～0.761）升高是老年HF患者术后PWH的保护因素,糖尿病（OR=2.651,95％CI：1.182～5.948）、术中出血量增加（OR=1.013,95％CI：1.005～1.021）是危险因素（P＜0.05）。ROC曲线分析显示,PNI和血清TRF水平单独与联合预测老年HF患者术后PWH的曲线下面积（AUC）分别为0.808、0.770、0.871,灵敏度分别为70.37％、55.56％、92.59％,特异度分别为80.65％、85.81％、70.32％。二者联合预测老年HF患者术后PWH的AUC大于二者单独预测（P＜0.05）。结论：术前PNI和血清TRF水平降低是老年HF患者术后PWH的危险因素,二者联合对老年HF患者术后PWH的预测价值较高。     

血清NSE、LP-PLA2联合CAR对老年股骨粗隆间骨折患者PFNA内固定术后谵妄的预测价值

摘要 目的：探讨血清神经元特异性烯醇化酶（NSE）、脂蛋白相关磷脂酶A2（LP-PLA2）联合C-反应蛋白与白蛋白比值（CAR）对老年股骨粗隆间骨折患者闭合复位防旋髓内钉（PFNA）内固定术后谵妄的预测价值。方法：选择2020年4月至2023年2月北京中医药大学第三附属医院收治的209例老年股骨粗隆间骨折患者。所有患者均行PFNA内固定术治疗，术前检测血清NSE、LP-PLA2、CAR，术后根据是否发生谵妄分为谵妄组和非谵妄组。多因素Logistic回归分析术后谵妄的因素。受试者工作特征（ROC）曲线分析NSE、LP-PLA2、CAR预测术后谵妄的价值。结果：术后43例发生谵妄，发生率为20.57%。谵妄组血清NSE、LP-PLA2、CAR高于非谵妄组（P＜0.05）。多因素Logistic回归分析显示年龄偏大、手术时间过长、高NSE、高LP-PLA2、高CAR是老年股骨粗隆间骨折患者术后谵妄的危险因素（P＜0.05）。NSE、LP-PLA2、CAR预测老年股骨粗隆间骨折患者术后谵妄的曲线下面积（AUC）为0.784、0.808、0.820，联合预测的AUC 为0.907，高于单独预测。结论：老年股骨粗隆间骨折PENA术后谵妄患者血清NSE、LP-PLA2、CAR增高，高水平NSE、LP-PLA2、CAR是术后谵妄的主要危险因素。联合NSE、LP-PLA2、CAR对术后谵妄风险有较高预测价值。     

血清肌钙蛋白I、同型半胱氨酸、乳酸联合检测对动脉瘤性蛛网膜下腔出血患者术后转归的预测价值分析

摘要 目的：研究血清肌钙蛋白I（cTnI）、同型半胱氨酸（Hcy）以及乳酸（Lac）联合检测对动脉瘤性蛛网膜下腔出血（aSAH）患者术后转归的预测价值。方法：将本院从2018年1月～2020年1月期间收治的115例aSAH患者纳入研究,记作研究组。另取100例健康体检志愿者作为对照组。检测并比较所有受试者血清cTnI、Hcy以及Lac水平。此外,按照术后转归情况将研究组患者分作转归不良组以及转归良好组,比较两组各项基线资料以及血清cTnI、Hcy、Lac水平,并采用多因素Logistic回归分析aSAH患者术后转归不良的影响因素。另外,借助受试者工作特征（ROC）曲线分析明确cTnI、Hcy及Lac联合检测对aSAH术后转归不良的预测价值。结果：研究组血清cTnI、Hcy以及Lac水平均明显高于对照组（P＜0.05）。转归不良组血清Hcy以及Lac水平均高于转归良好组（P＜0.05）。经单因素分析可得：Hunt-Hess分级、动脉瘤大小、术前格拉斯哥昏迷指数（GCS）评分、术前脑疝、术前再出血均和aSAH患者术后转归密切相关（均P＜0.05）。经多因素Logistic回归分析发现：Hunt-Hess分级Ⅳ～Ⅴ级、动脉瘤大小≥5 mm、术前GCS评分、术前脑疝、术前再出血及血清cTnI、Hcy、Lac均是研究组患者术后转归不良的危险因素（均P＜0.05）。经ROC曲线分析可得：血清cTnI、Hcy及Lac联合预测aSAH患者术后转归不良的曲线下面积、灵敏度、特异度以及约登指数均高于上述三项指标单独预测。结论：血清cTnI、Hcy及Lac联合检测对aSAH患者术后转归不良的预测价值较高。     

术前修正衰弱指数联合血清PGE2、IL-17A预测老年髋关节置换术患者术后谵妄的临床研究

摘要 目的：探讨术前修正衰弱指数（mFI）联合血清前列腺素E₂（PGE₂）、白细胞介素-17A（IL-17A）预测老年髋关节置换术患者术后谵妄（POD）的临床研究。方法：选取2020年1月～2022年7月四川大学华西医院收治的276例老年髋关节置换术患者，根据是否发生POD分为POD组和非POD组。计算术前mFI，采用酶联免疫吸附法检测血清PGE₂、IL-17A水平。分析老年髋关节置换术患者POD的影响因素，采用受试者工作特征（ROC）曲线分析mFI和血清PGE₂、IL-17A水平对老年髋关节置换术患者POD的预测价值。结果：276例老年髋关节置换术患者POD发生率为17.03%（47/276）。与非POD组比较，POD组mFI和血清PGE₂、IL-17A水平升高（P＜0.05）。多因素Logistic回归分析显示，年龄、糖尿病、脑卒中、mFI、PGE₂、IL-17A为老年髋关节置换术患者POD的独立危险因素（P＜0.05）。ROC曲线分析显示，mFI联合血清PGE₂、IL-17A预测老年髋关节置换术患者POD的曲线下面积（AUC）大于mFI、PGE₂、IL-17A单独预测（P＜0.05）。结论：mFI和血清PGE₂、IL-17A水平升高与老年髋关节置换术患者POD独立相关，mFI联合血清PGE₂、IL-17A预测老年髋关节置换术患者POD的价值较高，可能成为老年髋关节置换术患者POD的辅助预测指标。     

术前血清Lp-PLA2、sST2水平与急性冠状动脉综合征患者PCI术后冠状动脉慢血流/无复流的关系研究

摘要 目的：探讨急性冠状动脉综合征（ACS）患者术前血清脂蛋白相关磷脂酶A2（Lp-PLA2）、可溶性生长刺激表达基因2蛋白（sST2）表达情况,分析术前血清Lp-PLA2、sST2与经皮冠脉介入术（PCI）术后冠状动脉慢血流/无复流（CSF/CNF）的关系。方法：选择2019年9月至2022年9月在徐州医科大学附属连云港医院心内科进行PCI治疗的ACS患者386例为ACS组,根据术后心肌梗死溶栓实验（TIMI）血流分级分为CSF/CNF组（138例）和正常血流组（248例）;另选择同期在本院体检的健康对象174例为健康对照组。采用酶联免疫吸附法（ELISA）检测ACS患者术前及健康志愿者体检时血清Lp-PLA2、sST2水平,比较ACS组与健康对照组血清Lp-PLA2、sST2水平。采用单因素及多因素logistic回归模型分析CSF/CNF的影响因素,采用受试者工作特征（ROC）曲线分析术前血清Lp-PLA2、sST2对ACS患者PCI术后CSF/CNF的预测价值。结果：术前血清Lp-PLA2、sST2水平ACS组高于健康对照组（P＜0.05）;单因素分析结果显示,CSF/CNF组术前血肌酐（Scr）、超敏C反应蛋白（hs-CRP）、D-二聚体（D-D）、Lp-PLA2、sST2水平均高于正常血流组（P＜0.05）;多因素logistic回归模型分析结果显示,术前血清Lp-PLA2、sST2水平升高是ACS患者PCI术后发生CSF/CNF的独立危险因素（P＜0.05）。ROC曲线分析结果显示,两指标联合预测ACS患者PCI术后CSF/CNF的曲线下面积（AUC）显著高于术前血清Lp-PLA2、sST2单独检测。结论：PCI术后发生CSF/CNF的ACS患者术前血清Lp-PLA2、sST2水平异常升高,术前检测血清Lp-PLA2、sST2能较准确预测CSF/CNF,两者联合检测的预测效能更高。     

术前AGR、NLR、FOXQ1联合检测对低位直肠癌根治性切除手术患者术后复发的预测价值

摘要 目的：探讨术前白蛋白-球蛋白比值（AGR）、中性粒细胞-淋巴细胞比值（NLR）、叉头框蛋白Q1（FOXQ1）联合检测对低位直肠癌根治性切除手术患者术后复发的预测价值。方法：选取2017年3月至2019年4月重庆市第九人民医院就诊的拟行低位直肠癌根治性切除手术患者110例,术前均检测血清AGR、NLR、FOXQ1水平。随访3~48个月,中位随访时间为25.5个月,失访9例,101例根据术后复发情况将患者分为复发组（n=16）和未复发组（n=85）。比较两组患者术前血清AGR、NLR、FOXQ1水平,收集患者的临床资料,以Logistic回归分析探讨低位直肠癌患者术后复发的危险因素,绘制受试者工作曲线（ROC）判定术前血清AGR、NLR、FOXQ1水平对低位直肠癌患者术后复发的预测价值。结果：复发组术前血清AGR水平低于未复发组,术前血清NLR、FOXQ1水平高于未复发组（P<0.05）;复发组患者肿瘤细胞分化程度为低分化、TNM分期为Ⅲ期、糖链抗原19-9（CA19-9）阳性占比高于未复发组（P<0.05）,复发组术后化疗占比低于未复发组（P<0.05）;Logistic回归分析结果显示,TNM分期为Ⅲ期、细胞分化程度为低分化、术前血清AGR降低、NLR升高、FOXQ1升高均为低位直肠癌患者术后复发的危险因素（P＜0.05）;ROC曲线结果显示,术前血清AGR、NLR、FOXQ1水平及三者联合对低位直肠癌患者术后复发的预测的曲线下面积（AUC）值分别为0.738、0.747、0.731、0.842。结论：术前检测血清AGR、NLR、FOXQ1水平对低位直肠癌根治性切除术患者术后复发预测具有一定的价值,且联合的预测价值更高。     

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.