实验高压电烧伤深筋膜微循环动态变化及意义

目的研究肢体高压电烧伤后深筋膜微循环变化规律。方法将28只家兔随机分成实验组与对照组。实验组家兔的右下肢采用1万伏额定电压 ,77mA电流及通电5s的方法制作单侧后肢电烧伤模型 ,对照组采用假电的方法制作单侧后肢假电烧伤模型 ,两组均采用“滴水开窗法”制作左侧下肢远端深筋膜微循环观测窗 ,并采用WX -9B型多部位微循环显微仪及其图像处理系统在通电前、通电后即刻、通电后30min、2、4、6h观测微动脉、毛细血管、后微静脉、微静脉的形态、流态、管周状态。结果肢体高压电烧伤后 ,微血管形态在30min内可观测到显著性变化 (P<0.05) ,表现为血管密度减小 ,微动脉、毛细血管、微静脉收缩 ,后微静脉扩张 ,微动脉、毛细血管均在6min以后变得不清以致模糊(P<0.05)、后微静脉、微静脉分别在2h、30min以后变得不清(P<0.05)。微血管内的流态以白微栓的变化可见规律性 ,即白微栓在电后2h开始出现 ,4h迅速达高峰 ,6h又有快速下降的趋势。微静脉和后微静脉在通电30min后有渗出(P<0.05) ,只有后微静脉在通电后2h有出血(P<0.05)。结论电烧伤后存在全身性反应 ,其在肢端深筋膜微循环的表现是一个阶段性加重的过程 :第一阶段电烧伤后30min内为缺血型微循环障碍 ,第二阶段微循环障碍包含两个方面 :其一是微血管的出血     

Skin ligaments: regional distribution and variation in morphology

Skin ligaments (SL) (L. retinacula cutis) are present extensively in the face, hands, feet, and in breast tissue, but have seldom been reported elsewhere in the body. The traditional histological view of the subcutaneous region is that it comprises a matrix of loose connective tissue devoid of fibrous specializations. The purpose of this study was to determine the structure and distribution of skin ligaments. Eight embalmed cadavers (3 males, 5 females, 69-90 years of age) were used in this study. Tissue was prepared using the E12 plastination technique. Macroscopic and microscopic examination demonstrated the widespread presence in the limbs and most of the rest of the body of fibrous strands linking the base of the dermis and the superficial fibers of the underlying deep fascia. The morphology and distribution of these skin ligaments were similar in the individuals examined. Variations in the structure of the skin ligaments depended on the presence of underlying muscle, neurovascular bundles, intermuscular septa and adipose tissue. We conclude that skin ligaments are complex fibrous structures that are present over most of the body. They form an extensive peripheral network in the subcutaneous fat. These 'ligaments' seem to provide an anchorage of skin to deep fascia that is flexible and yet resistant to mechanical loading from multi-directional forces. The use of the E12 plastination technique coupled with fluorescent confocal microscopy has been of benefit in visualizing and delineating SLs from other soft tissue structures in three planes.     

Effects of local nerve cooling on conduction in vagal fibres shed light upon respiratory reflexes in the rabbit

In ten vagus nerves the effect of local cooling on the compound action potential was studied in the temperature range of 34 to 0 °C in spontaneously breathing, anaesthetized rabbits. The mean temperature at which the myelinated (A) fibres were completely blocked, was 10.2±2.4 °C (mean ± S.D.). In nine nerves, local vagus cooling to 0 °C failed to block all non-myelinated (C) fibres. In one nerve, total blocking occurred at 2.0 °C. We conclude that in the rabbit, the earlier found increase in tonic activity of the diaphragm following lung inflation or deflation during bilateral local vagus cooling to a temperature between 8 and 0 °C is due to afferent impulses in vagal C fibres.     

腰方肌阻滞对腹腔镜肝切除术后急性疼痛影响的回顾性研究

目的　回顾性分析腰方肌阻滞对腹腔镜肝切除术后急性疼痛的影响。 方法　选取2018年1~8月于我院行择期腹腔镜肝切除术患者24例，平均分为2组，对照组仅采用全凭静脉麻醉，腰方肌组采用腰方肌阻滞（quadratus lumborum block，QLB）联合全凭静脉麻醉，两组术后镇痛方案均为自控静脉镇痛（patient controlled intravenous analgesia，PCIA）。麻醉期间常规监测患者心率、血压、脉搏氧饱和度，采用腰方肌阻滞的患者在阻滞完成后15 min记录阻滞平面。分别于术前、术后2 h、术后8 h、术后12 h、术后24 h和术后48 h对患者进行VAS评分。记录患者术中和术后PCIA阿片类药物消耗情况及术后48 h内恶心呕吐、尿潴留、瘙痒和呼吸抑制等并发症发生情况。 结果　腰方肌组患者在术后2、8、12 h 3个时间点VAS评分显著低于对照组，差异具有统计学意义（P<0.05）。腰方肌组12名患者最高阻滞平面为T6（T6~10），最低阻滞平面为L1（T12~L1）。与对照组相比，腰方肌组术中和术后PCIA阿片类药物消耗均显著减少，差异具有统计学意义（P<0.05）。 结论　腰方肌阻滞能够有效缓解腹腔镜肝切除术患者术后急性期疼痛，减少围术期阿片类药物用量。     

腹腔镜下左半结肠切除术相关筋膜平面的解剖观察

目的：探讨左半结肠切除术相关筋膜的解剖学特点和外科平面的鉴别方法。临床资料和方法：2003-2004年南方医院普通外科施行的腹腔镜左半结肠切除术15例，病例均为左半结肠癌。对腹腔镜下左半结肠后外侧、中线侧和直肠后外侧相关筋膜的解剖特点和镜下定位标志进行观察和描述。结果：在乙状结肠第一曲外侧缘肠壁与左侧腰大肌筋膜之间存在一个固定的粘连带，它是左侧Toldt’s线的尾侧端点。左半结肠系膜后外侧存在肾前筋膜；中线侧存在主动脉前筋膜；直肠系膜后外侧存在盆筋膜壁层。这三个部位的筋膜相互延续。结论：乙状结肠和左侧腰大肌筋膜之间的粘连带是左半结肠切除术外侧分离的起点。肾前筋膜是衬贴于左半结肠和直肠系膜后面的一层连续筋膜，在不同的解剖位置有不同的表现形式。左半结肠切除术的外科平面统一于结直肠系膜与连续的肾前筋膜之间。     

Autoantibody response to the Ro/La particle may predict outcome in neonatal lupus erythematosus.

This study was undertaken to determine the role of antibodies against both recombinant Ro (r-Ro) and La (r-La) proteins and polypeptides derived from the recombinant La protein in predicting fetal and neonatal outcome in children at risk to develop neonatal lupus erythematosus (NLE). All sera were obtained in the perinatal period and quantitative ELISA assays were used. We collected 41 maternal sera within 2 months of delivery of a child with NLE (21 with congenital heart disease block (CHB) and 20 with dermatologic NLE) and 19 sera from anti-Ro and/or anti-La antibody-positive mothers with systemic lupus erythematosus (SLE) who delivered a child without NLE. All sera were tested for anti-r-La and anti-r-Ro antibodies by ELISA, and most sera were tested for antibodies directed against La polypeptides by immunoblot. We found significantly higher anti-r-La antibody levels in the sera from mothers of children with NLE compared with sera from mothers of unaffected children (0.67 +/- 0.43 versus 0.14 +/- 0.30; P < 0.0001). There was a statistically significant difference in the mean anti-r-La levels between the sera of mothers of children with CHB compared with dermatologic NLE (0.51 +/- 0.45 versus 0.83 +/- 0.37 respectively; P = 0.0091). When we examined antibodies directed against the recombinant 52-kD Ro protein, there was a statistically significant elevation of titres in the sera of mothers of NLE children (0.77 +/- 0.35) compared with non-NLE mothers (0.29 +/- 0.39; P < 0.0001). There was no difference in the r-Ro levels between mothers of children with dermatologic NLE compared with CHB (0.82 +/- 0.37 versus 0.71 +/- 0.74; P = 0.32). When we examined polypeptides derived from the recombinant La protein, the mean number of polypeptides recognized by sera from mothers of children with NLE was significantly higher than the mean number of polypeptides recognized by sera from mothers of unaffected children (5.1 +/- 0.54 versus 2.3 +/- 0.54 respectively; P < 0.001). More importantly, when we examined the individual polypeptides, we found that only sera from mothers of children with NLE and not from mothers of unaffected children recognized a polypeptide designated DD (30% versus 0%, respectively). These studies indicate that the autoantibody response to the Ro/La particle can differentiate sera from mothers of children with NLE and sera from mothers of unaffected children. Furthermore, there was a difference in the anti-La autoantibody response between mothers of children with CHB and dermatologic NLE.(ABSTRACT TRUNCATED AT 400 WORDS)     

耳大神经及腮腺筋膜解剖的再认识与腮腺切除手术的改良

目的：对耳大神经及腮腺筋膜解剖进行再认识，由此改良腮腺切除手术方法。方法：解剖成人尸体10侧，术中活体解剖20侧，对耳大神经和腮腺筋膜的解剖要素进行观察。根据观察结果进行改良腮腺切除术14例，即在腮腺筋膜表面翻瓣后，由前向后另翻腮腺筋膜瓣，切除腮腺后将筋膜瓣复位缝合，完整保留耳大神经和腮腺筋膜。结果：耳大神经在下颌角水平之上0-2cm依次分耳后、耳垂、耳前支，神经主干末段和分支起始段均分布于腮腺筋膜浅层表面，后者致密，其致密纤维包裹在神经周围。改良手术后2例（14．3％）发生轻度Frey’s综合征，无1例发生术区皮肤长期麻木、长期面瘫、涎瘘及肿瘤复发。结论：耳大神经各分支和腮腺筋膜具有不可代替的解剖生理功能，改良术式能将两者完好保留，显著降低术后并发症。     

Fast and slow blockades of the inward-rectifier K+ channel by external divalent cations in guinea-pig cardiac myocytes

The present patch-clamp study shows that external Mg²⁺, Ca²⁺ and Sr²⁺ decrease the unit amplitude of inward current through the inward-rectifier K⁺ channel in a concentration-dependent manner. Sr²⁺ produces a voltage-dependent flickering block as well, and the fractional electrical distance between the external orifice and the Sr²⁺ binding site () is 0.73. The decrease of unit amplitude is reversible and voltage independent while it does not increase the noise level on the open-channel current. Unit current decreased by Mg²⁺ or Ca²⁺ has a longer mean open time, which is inversely proportional to the unit amplitude. External Mg²⁺ does not decrease the amplitude of unit outward current. A surface potential shift, measured using voltage-dependent Cs⁺ block (=1.60), failed to explain the current decrease. Therefore, we conclude that (1) the external divalent cations cause an extremely fast channel block, which appears as a decreased amplitude of the unit current on the recording system; (2) the blocking site (fast site) is present near the external orifice of the channel, and it is separate from the blocking site (slow site) to which Cs⁺ and Sr²⁺ bind.     

颈深筋膜及筋膜间隙的计算机三维重建

目的 :对颈深筋膜及深筋膜间隙进行计算机三维重建以显示其立体结构。方法 :用生物塑化技术制作薄层断面标本 ,在SGI工作站上 ,采用双线提取筋膜及间隙轮廓的方法对颈深筋膜及其间隙进行了三维重建。结果 :重建出咽后间隙、颈动脉间隙和内脏间隙及颈部的大血管和重要器官。重建结构均能单独显示、任意搭配显示或总体显示 ,可在三维空间位置上绕任意轴旋转任意角度。结构 :用双线法提取筋膜及间隙轮廓 ,能重建出筋膜间隙并能同时清楚显示间隙内的结构 ,为筋膜间隙的计算机三维重建提供了一种新的方法     

Mechanisms of the inhibition of Shaker potassium channels by protons

Potassium channels are regulated by protons in various ways and, in most cases, acidification results in potassium current reduction. To elucidate the mechanisms of proton-channel interactions we investigated N-terminally truncated Shaker potassium channels (K_v1 channels) expressed in Xenopus oocytes, varying pH at the intracellular and the extracellular face of the membrane. Intracellular acidification resulted in rapid and reversible channel block. The block was half-maximal at pH 6.48, thus even physiological excursions of intracellular pH will have an impact on K⁺ current. The block displayed only very weak voltage dependence and C-type inactivation and activation were not affected. Extracellular acidification (up to pH 4) did not block the channel, indicating that protons are effectively excluded from the selectivity filter. Channel current, however, was reduced greatly due to marked acceleration of C-type inactivation at low pH. In contrast, inactivation was not affected in the T449V mutant channel, in which C-type inactivation is impaired. The pH effect on inactivation of the wild-type channel had an apparent pK of 4.7, suggesting that protonation of extracellular acidic residues in Kv channels makes them subject to pH regulation.