Dynamic response of the occipito-atlanto-axial (C0-C1-C2) complex in right axial rotation.

The torque-angular deformation in right axial rotation until failure of the ligamentous occipito-atlanto-axial complex subjected to variable loading rate (dynamic) axial torque was characterized using a biaxial MTS system. A special fixture and gear box that permitted right axial rotation of the specimen until failure without imposing any additional constraints were used to obtain the data. The specimens were divided into three groups and tested until failure at three different dynamic loading rates: 50, 100, and 400 degrees/s. A previous study by the authors provided data for quasi-static (4 degrees/s) loading conditions. The torque versus rotation curves can be divided into two straight regions and two transition zones. The plots clearly indicated that at loading rates higher than 4 degrees/s, the specimens became stiffer in the region of steadily increasing resistance prior to failure. The increase in stiffness was maximum at 100 degrees/s. The stiffness decreased somewhat at 400 degrees/s in comparison with 100 degrees/s, but this decrease was not significant. The resulting torque-right axial rotation curves were also examined to estimate the magnitude of maximum resistance (torque) and the corresponding angular rotation value. The average maximum resistance torque increased from 13.6 Nm at 4 degrees/s to 27.8 Nm at 100 degrees/s. The corresponding right angular rotation data (65-78 degrees), however, did not show any significant variation with loading rate. Posttest dissection of the specimens indicated that the type of injury observed was related to the rate of axial loading imposed on a specimen during testing.(ABSTRACT TRUNCATED AT 250 WORDS)     

Thrombosis triggered by severe arterial lesions is inhibited by oral administration of a glycoprotein IIb/IIIa antagonist

Platelet aggregation and thrombosis play an important role in the onset of acute coronary events. Regardless of the stimulus for activation, platelet thrombus formation is ultimately regulated through the IIb/IIIa receptor complex. The effects of oral administration of xemilofiban, a non-peptide mimetic of the RGDF sequence of the IIb/IIIa receptor complex, on thrombus formation were evaluated in a canine model. Xemilofiban significantly reduced platelet deposition on severely damaged arterial wall. Platelet deposition was reduced at both low (13 ± 1 from 56 ± 18 × 10⁶ platelets cm⁻²; P  < 0.05) and high (23 ± 2 from 111 ± 21 × 10⁶ platelets cm⁻²; P  < 0.01) shear rates. Platelet deposition was reduced to a monolayer as seen by electron microscopy (platelet–vessel wall interaction). Therefore, the availability of an orally active IIb/IIIa antagonist for chronic use may have significant value in preventing thrombus formation in those clinical situations associated with severe arterial injury, such as atherosclerotic plaque disruption.     

病毒性心肌炎及扩张型心肌病患者心内膜心肌活检标本中免疫球蛋白的检测

对病理学确诊的25例病毒性心肌炎（VMC）和10例扩张型心肌病（DCM）患者心内膜心肌活检标本，运用ABC技术，进行了免疫球蛋白IgG、IgM、IgA和补体C3的检测。结果：20例VMC和9例DCM的标本中，发现了IgG和IgM的沉积，主要分布于心肌肌膜和毛细血管内皮，IgG的肌膜沉积与同步做的病理切片中观察到的心肌细胞坏死和炎性细胞浸润有病理形态学联系。两组患者中均未发现IgA和C3沉积。结果显示，IgG是参与VMC和DCM心肌损伤的主要免疫球蛋白，心肌病变与抗体诱导的免疫反应有关。     

基于多分辨率分析的心电图QRS波检测

从多分辨率分析出发，构造出一个用于心电图R波检测的滤波器，并在此滤波器的基础上提出了一种新的R波检测算法。本文详细论述了滤波器的构造方法和新的R波检测算法的原理及在实现中采用的一些策略，经MIT-BIH标准心律失常数据库验证，该算法对于各种干扰尤其是肌电干扰具有很强的抑制能力。算法实现简单，计算量小，在ECG信号的脱机和实时处理程序中均可使用。     

腹腔镜与开腹胆囊切除胃肠压力变化的临床研究

目的 :从胃肠道压力变化的角度探讨腹腔镜与开腹胆囊切除对胃肠运动功能的影响。方法 :腹腔镜胆囊切除 30例 (男 6例 ,女 2 4例 ,4 7± 4岁 ) ,开腹胆囊切除 30例 (男 9例 ,女 2 1例 ,4 7± 7岁 ) ,分别于手术前 1d行胃电图描记 ,记录术后 3、2 4、4 8、72h胃电图及监测胃窦、十二指肠和空肠压力 (移行性运动复合波 ,MMCⅢ )。结果 :(1)手术前腹腔镜和开腹胆囊切除患者胃电频率差异无显著性 (P >0 .0 5 ) ;(2 )腹腔镜胆囊切除组术后 3、2 4h正常波所占百分比低于术前 ,但差异无显著性 (P >0 .0 5 ) ,术后 4 8h恢复正常 ;(3)开腹胆囊切除组术后起 3h正常波所占百分比明显低于术前 ,差异有显著性 (P <0 .0 1) ,术后 2 4、4 8h正常波的百分比与术前差异无显著性 ,术后 72h恢复正常 ;(4) 2组患者术后胃窦、十二指肠及空肠压力低于健康人群 (P<0 .0 5 ) ;(5 ) 2组胃窦部收缩压力及收缩曲线下面积术后第 1、2、3d较术后 3h明显升高 (P <0 .0 5 ) ,且随时间延长有逐渐增大的趋势 ,腹腔镜组术后 72h恢复正常 ,十二指肠及空肠术后 3d内无明显变化 ;(6 ) 2组间胃电频率 ,胃窦部、十二指肠及空肠压力变化差异无显著性 (P >0 .0 5 ) ,但显示有差别。结论 :腹腔镜与开腹胆囊切除术均可引起胃电频率及胃肠压力变化 ,开     

Dislocation of an upper third molar into the maxillary sinus after a severe trauma: a case report

Abstract – Dental injuries are common following facial trauma. This article presents a rare injury: the dislocation of a third molar into the maxillary sinus after complex mandibular and maxillary tuberosity fractures. The possible mechanism and clinical treatment are discussed.     

IL-2-PE40体外抑制γ-干扰素诱导的角膜内皮细胞MHC抗原表达的研究

目的了解正常大鼠角膜内皮细胞在体外经γ-干扰素诱导后，主要组织相容性复合体（major histoeompatibility complex，MHC）-Ⅰ、Ⅱ类抗原异常表达的情况。并观察比较白细胞介素-2-绿脓杆菌外毒素（interleukin-2-pseudomonas exotoxin40。IL-2-PE40）、环胞霉素A（cyclosporine A，CsA）对角膜内皮细胞MHC-Ⅰ、Ⅱ类抗原异常表达的免疫抑制作用。方法采用ACAS-570黏附式细胞分析仪和免疫荧光技术，对体外原代培养经γ-干扰素诱导后的正常大鼠角膜内皮细胞分成A、B2组进行MHC-Ⅰ、Ⅱ类抗原表达的相对量测定，并在培养液中加入新型免疫抑制剂IL-2-PE40和CsA，进一步测定角膜内皮细胞MHC-Ⅰ、Ⅱ类抗原的表达量。结果未加入γ-干扰素前，MHC-Ⅰ类抗原的表达量为97．8±8．1，MHC-Ⅱ类抗原无表达；经γ-干扰素诱导后，MHC—Ⅰ类抗原的表达量为1006．3±13．2，MHC-Ⅱ类抗原表达量为406．5±10．5，γ-干扰素加入前后MHC-Ⅰ、Ⅱ类抗原比较均有统计学意义（P〈0．05）。IL-2．PE40组MHC-Ⅰ类抗原的表达量为618．2±13．5，MHC-Ⅱ类抗原表达量为204．5±7．8，CsA组MHC-Ⅰ类抗原的表达量为609．5±12．9，MHC-Ⅱ类抗原表达量为198．5±6．9，IL-2．PE40组、CsA组分别与注射用水比较，MHC—Ⅰ、Ⅱ类抗原间均有统计学意义（P〈0．05）。IL-2．PE40组与CsA组比较．MHC—Ⅰ、Ⅱ类抗原间差异无统计学意义（P〉0．05）。结论在体外，γ-干扰素可诱导角膜内皮细胞MHC-Ⅰ、Ⅱ类抗原异常表达；IL-2-PE40及CsA均能不同程度的抑制这种表达。[眼科新进展20ff7；27（3）：170．172]     

聚醋酸乙烯酯与铜（Ⅱ）离子的配位反应及其催化作用

以ＥＳＲ、ＵＶ和ＩＲ表征Ｃｕ（２＋）离子与ＰＶＡＣ的配位反应。根据ＣＵＣｌ２·２Ｈ２Ｏ乙醇溶液与ＰＶＡｃ－ＣｕＣｌ２·２Ｈ２Ｏ乙醇溶液的电导率差值随Ｃｕ（２＋）离子摩尔浓度变化的明显转析点得知，１个Ｃｕ（２＋）离子大约能与ＰＶＡｃ４个链节单元配位。证实ＭＭＡ在Ｃｕ（Ⅱ）－ＰＶＡｃ配合物／Ｎａ２ＳＯ３体系的聚合体是无规ＰＭＭＡ，得率为７０％。讨论了ＭＭＡ在Ｃｕ（Ⅱ）－ＰＶＡｃ配合物／Ｎａ２ＳＯ３体系络合催化引发下的游离基反应历程。     

维胺酯-β-环糊精包合物的研究

应用３因素８水平的均匀设计方法，优化出维胺酯－β－环糊精包合物最佳制备条件，所得包合物的包合率为９９．３％，其表观稳定常数为１３９４Ｍ－１．     

Interdigestive small bowel motility and duodenal bacterial overgrowth in experimental acute pancreatitis

The objective of this study is to investigate the effects of an acute necrotizing pancreatitis (ANP), without biliary obstruction, on the migrating motor complex (MMC), small bowel bacterial overgrowth (SBBO), bacterial translocation (BT) and infection of the pancreas simultaneously. Rats were divided into four groups: mild pancreatitis, control, ANP and sham operated control. Jejunal myoelectrodes were used to measure MMCs. Blood, peritoneal fluid, bile, and abdominal organs were harvested for microbial culturing 72 h after induction of pancreatitis. The splenic portion of the pancreas was taken for histology. During ANP the MMC cycle length was significantly increased from 14.1 +/- 0.2 to 22.4 +/- 1.9 min (P < 0.05). The duodenum of ANP rats was in contrast with the other groups characterized by Enterobacteriacae (> 3 log 10 CFU g-1 in seven of 12 rats, P < 0.05). A positive correlation (r = 0.78, P < 0.01) existed between duodenal Gram-negative and anaerobic flora and the MMC cycle. Correlation between MMC cycle length and BT to the pancreas was positive as well (r = 0.70, P < 0.01). A positive correlation (r = 0.85, P < 0.01) was found between the severity of pancreatitis and duodenal bacterial overgrowth. During ANP without biliary obstruction, the jejunal MMC is disturbed and consequently SBBO occurs. The correlation between the severity of pancreatitis, the disturbance of the MMC and SBBO suggests an important pathophysiological role of the proximal small bowel in the infection of pancreatic necrosis.