备用根大鼠脊髓后角提取液中神经营养活性组分的分离及生物活性测定

制作备用根大鼠脊髓后角提取液，取其分子量大于10kD的组分进行SDS-聚丙烯酰胺凝胶电泳分析，发现手术侧和非手术侧的电泳区带数目大致相同，但手术侧样品的第四条蛋白质区带扫描的吸收峰面积百分比大于非手术侧样品的第四条区带，两者在量上可能有差别。将手术侧样品经交联葡聚精G-75凝胶层析，得到两个洗脱峰．第一峰洗脱液有促进体外培养的背根节神经元存活及其突起生长的作用，其电泳分析显示4条主带，分子量在40～80kD之间．实验结果提示部分去传入纤维支配的脊髓后角组织含有神经营养活性物质，该物质的分子量约在40～78kD之间．     

大鼠脊髓缺血再灌流时脊髓神经元对躯体和内脏传入刺激的反应

５０只大鼠用乌拉坦麻醉，箭毒制动。通过阻断腹主动脉血流以模拟腰段脊髓的局部缺血和再灌流损伤，玻璃微电极记录Ｌ２节段脊髓单位放电（ＳＣＵＤｓ），观察缺血再灌流时脊髓神经元对腓神经刺激（ＰＮＶ），内脏大神经刺激（ＶＬＮＶ）及两者同时刺激（ＳＶ）的反应。结果在缺血前所记录的１３３个自发放电单位中，对３种刺激均产生兴奋（Ｅ）、抑制（Ｉ）及无反应（ＮＲ）３种形式的反应，表明大鼠Ｌ２节段脊髓存在躯体、内脏和躯体内脏反应性神经元，并有会聚和阻塞现象。在脊髓缺血再灌流时，神经元对ＰＮＶ、ＶＬＮＶ、ＳＶ也产生Ｅ、Ｉ、ＮＲ３种形式的反应，提示脊髓缺血再灌流时神经元对躯体和内脏传入刺激的反应形式不受影响；但缺血时ＳＣＵＤｓ对ＰＮＶ、ＶＬＮＶ产生反应的单位数减少，这表明脊髓缺血损伤时神经元对躯体和内脏传入刺激的反应性减弱，随着缺血损伤加重，脊髓神经元对躯体内脏信号的整合功能下降     

肺移植急性排斥反应及其控制实验研究

观察了大鼠实验性肺移植术后急性排斥反应的病理改变。异系间移植术后２ｄ，移植肺内小血管及支气管周围出现单核细胞浸润。４ｄ上述细胞浸润波及肺泡壁，导致肺泡壁增厚，肺内小静脉系及毛细血管管腔变窄，血流不畅。术后６ｄ，血液循环严重障碍处，肺泡完全坏死，环抱素Ａ可使上述排斥反应得到明显抑制。     

Improved sib-pair linkage test for disease susceptibility loci

An improved sib-pair test for linkage is introduced which is superior to the previously proposed tests. The test is derived from the standard chi-squared goodness of fit statistic by restricting the alternative hypothesis to the genetically possible. Critical values are given and exact power comparisons are made with the previously proposed tests. The new test is shown to be more powerful for finite samples as well as being asymptotically uniformly most powerful. © 1993 Wiley-Liss, Inc.     

刺激视上核对大鼠痛阈及电针镇痛的影响

以钾离子透引起的大鼠甩尾反应为痛指标，观察了电和化学刺激视上核（ＳＯＮ）对大鼠痛阈（ＰＴ）和电针（ＥＡ）镇痛的影响。电刺激ＳＯＮ后，ＰＴ明显高于假刺激组（Ｐ＜０．０５～０．００１），电刺激ＳＯＮ后电针足三里，镇痛效应明显提高，并有明显的量效关系。电刺激ＳＯＮ的近旁部位（０．５—１ｍｍ）对ＰＴ及电针镇痛无明显影响。ＳＯＮ内注射Ｌ－谷氨酸（Ｌ－Ｇｌｕ）后痛阈和电针镇痛效应都明显对照组，也有明显的量效关     

The long-term effect of pinealectomy on the crypts of the rat gastrointestinal tract

Abstract: Previously it has been found that rat small bowel crypt cell hyperplasia occurred several weeks after pinealectomy. To determine if this effect was longer-lasting (because of the possible role of the pineal in bowel malignancy) the crypt cell proliferation rate was determined in rat small bowel and colon 6 months after pinealectomy, using a stathmokinetic technique. Although the hyperproliferative effect of pinealectomy was well maintained in the small bowel crypts after 6 months, the hyper proliferative effect in the colonic crypts was much less marked. There is no obvious explanation for these findings, although it is possible that regional differences in levels of gut neuropeptides or melatonin are involved. The mechanism of the effect of pinealectomy on the crypts remains unexplained—in particular, why the effect is so prolonged.     

Endotoxin-induced uveitis (EIU) in the rat: A study of inflammatory and immunological mechanisms

Endotoxin-induced uveitis (EIU) can be produced by systemic injection of endotoxin (ET). It is not clear yet why exclusive ocular involvement occurs in this model. To clarify this question and to establish the sequence of inflammatory events, EIU was induced in Lewis rats by footpad injection of Salmonella ET. Ocular inflammatory response (anterior chamber cells and proteins), aqueous inflammation mediators (thromboxane B₂, prostaglandin E₂, leukotriene B₄ and substance P) and MHC class 2 (Ia) antigen expression in the ciliary body were monitored for 72 hours. Thromboxane B₂ was detected early in the aqueous humor, peaking already 1 hour after ET injection. Prostaglandin E₂ & leukotriene B₄ peaks and a second peak of thromboxane B₂ were recorded 18 hours after ET-injection, at the time of maximal ocular inflammation. MHC-class 2 expression was first detected in the ciliary body stroma at the vascular level 6 hours after ET injection and was massively expressed in the ciliary body epithelium at 18 and 72 hours. It is hypothetized that ciliary body endothelium is particularly sensitive to the effect of ET and is the site of thrombocyte adherence. Vascular damage leads in succession to cellular infiltration, release of inflammation mediators and disruption of blood-ocular barrier. MHC-class 2 expression is a secondary phenomenon and is probably at the origin of additional tissue damage from immune effector mechanisms.     

Exteroceptive suppression periods in jaw-closing muscles. Variability and relation to experimental pain and sustained muscle contraction

The duration of the late exteroceptive suppression period (ES₂) of temporal muscle EMG activity has been reported to be reduced in patients suffering from chronic tension-type headache. Methods of recording and analysing ES₂ have varied between centers and reproducibility of results within subjects , although insufficiently studied, has generally been poor. ES₂ was investigated in 30 healthy subjects, using a computerized technique of recording, rectifying and averaging the EMG signals. Hour to hour and week to week variations of ES₂ durations were calculated, and the influence of pain during a cold pressor test and of sustained muscle contraction on ES₂ durations was investigated. The intra-individual variation of ES₂ durations was 16.0% from hour to hour and 20.7% from week to week. The inter-individual variation was 36.7%. The present method for analysis of ES₂ periods proved to be reliable, as the intra-observer variation was 4.2% and the inter-observer variation 4.6%. ES₂ periods were significantly shorter on the first compared to the second day of examination ( p = 0.006) and during experimental pain ( p = 0.0005). We recommend the use of the computerized averaging technique in future studies and caution against the dependence of results upon factors such as conditioning and pain.     

Hereditary Hypertriglyceridemic Rat: A New Animal Model of Metabolic Alterations in Hypertension

Hereditary hypertriglyceridemic rats (hHTg) were developed as a new genetic model for the study of relationships between blood pressure (BP) and metabolic abnormalities. This strain has been produced by selective inbreeding from Wistar rats according to the rise of plasma triglycerides induced by a high-sucrose diet. Though hHTg rats display hypertriglyceridemia, impaired glucose tolerrance, hyperinsulinemia, insulin resistance and increased BP even without nutritional stimuli, high sucrose feeding further aggravates these symptoms. High plasma triglycerides levels in hHTg rats seem to be a consequence of their hyperproduction. Impaired insulin action is responsible for the defective glucoregulation in this strain. The loss of insulin responsiveness might be due to a reduction in the number of glucose transporters. Highly significant relationships among plasma triglycerides, ouabain-resistant Na⁺ transport and BP were demonstrated in the hHTg rats. Segregating populations (F2 hybrids) should be used for genetic analysis of the primary role of lipid and/or ion transport abnormalities in the pathogenesis of this form of genetic hypertension.     

Changes of Intestinal Caicitonin Gene-related Peptide in Acute Intestinal Radiation Sickness in Rats

The characteristic distribution of calcitonin gone-related peptide(CGRP)inthe small intestine of rats and its changes in acute intestinal radiation sickness(AIRS)were studied with immunocytochemistry(whole mount stretch preparations of the smallintestine and cryostat sections)and radio-immunoassay.It was found that in all the lay-ers of the intestinal walls,there were large amounts of CGRP immunoreactive(CGRP-I)nerve fibers which existed in especiaUy high density in the myenteric,submucosal andmucosal plexuses.There was also a rather high density of the nerves around the smallvessels of the small intestine and the intestinal crypts.Some CGRP-I neurons were seenin the myenteric and submucosal plexuses.In AIRS,the intestinal CGRP showed a dip-hasic change,in a lower level in the 24th h and a higher level in the 48th and 72nd h af-ter irradiation.The results indicate that CGRP may be related to the regulation of the motility,se-cretion,absorption,sensation,and regional blood flow of the gastrointestinal tract.Pro-bably,CGRP is released under the stress of AIRS and participates in the mechanism ofinjury through many ways especially through the influence on the regional blood flowand the increase of the permeability of blood vessels.