肾脏微血管内的压力分布与ANP的作用

本实验在40只大鼠经伺服零测压技术测定的肾脏微血管内压力分布及其ANP的作用均随血管树各段的口径变化而改变。分析小球前各段血管的压力降所占动脉总压降的比例得知:小叶间动脉占总压降的88％。肾小球毛细血管和出球小动脉亦具有较大的压力降。正常对照情况下,肾小球前血管内的压力分布与内径呈直线相关(r=0.869,n=65,P<0.01),其回归方程为平均压()=34.71±0.798×血管内径(D)。给ANP后肾小球前血管内的压力与内径仍呈直线相关(r=0.931,P<0.01),回归方程式为()=38.53+0.765D,其曲线右上移。本文结果提示,肾小球前微血管内压力分布与血管内径密切相关。小叶间动脉的阻力较大。     

升压治疗急性脑缺血再灌注损伤保护作用的实验研究

目的:探讨升压治疗局灶性脑缺血的保护作用及治疗的维持时间。方法:采用大鼠局灶性脑缺血再灌注模型,40只大鼠随机分为五组:模型对照组(A)、升压维持15min组(B)、维持45min组(C)、维持90min组(D)和120min组(E),观察各组神经功能评分、脑梗死体积和病理学改变。结果:神经功能缺损评分B、C、D组明显低于A组;B、C、D、E各组脑梗死体积明显低于A组,C、D、E组明显低于B组;各治疗组组织病理学改变比对照组轻,B组最轻。结论:缺血3h再灌注时,升压维持时间在2h以内对脑损伤有保护作用,升压最佳维持时间是15min。     

视网膜节细胞与视交叉上核AVP神经元联系的研究Ⅱ.假狂犬病毒顺行追踪与免疫荧光双重标记

为进一步揭示视网膜节细胞与视交叉上校精氨酸血管加压素神经元间有无直接的联系，本文将假狂犬病毒注入大鼠眼球内通过顺行追踪结合免疫荧光双重标记法观察到：（1）视交叉上核神经元被病毒感染的时间始于病毒注入后56h，并随存活时间的延长而增多；（2）呈绿色荧光的病毒感染神经元见于双侧视交叉上核，注射对侧优于同侧，主要位于视交叉上核的腹外侧部和嘴侧份，个别散在于二者之外;（3）视交叉上核内个别病毒感染的神经元可同时呈精氨酸血管加压素的红色荧光，此类双标神经元系病毒由视网膜节细胞顺行运输并跨突触传给视交叉上核的精氨酸血管加压素神经元所致。表明视网膜节细胞与视交叉上核的精氨酸血管加压素神经元间有直接的突触性联系。这一结果为视交叉上核节律机制和精氨酸血管加压素神经元的机能调控提供了进一步研究的线索。     

LHRH药代动力学试验

目的:研究黄体激素释放激素(Luteinizinghormone releasinghormone,LHRH)在大鼠体内的药动学规律。方法:用氯胺T法将125I标记到LHRH分子上(放化纯度96.2%),14只SD大鼠随机分为大剂量、小剂量组,每组7只,分别肌肉注射125I LHRH(小剂量组0.5mg.kg,大剂量组1.00mg.kg),给药后在21个不同时间点逐一取各鼠尾动脉血做放射性测定。结果:大鼠试验结果显示,大剂量组t1/2平均为67.83±20.84h;小剂量组半衰期平均为64.68±22.90h。LHRH的药—时曲线符合二室模型,大剂量LHRH和小剂量LHRH的主要药动学指标差别不大。结论:LHRH在大鼠体内的消除模式为二室模型,为一级动力学消除。     

Expression of alpha-smooth muscle actin by and contraction of cells derived from synovium

Cells derived from synovium have drawn interest as donor cells for articular cartilage tissue engineering because they have been implicated in certain cartilage repair processes in vivo and the chondrogenic potential of the cells has been demonstrated in vitro. Studies have demonstrated that several other types of musculoskeletal connective tissue cells--including chondrocytes, fibrochondrocytes, ligament fibroblasts and osteoblasts, and mesenchymal stem cells can express the gene for the contractile actin isoform, alpha-smooth muscle actin (SMA), and can contract analogs of extracellular matrix in vitro. Although the physiological roles of SMA-enabled contraction of these cells have yet to be established, cell-mediated contraction of scaffolds employed for tissue engineering can alter the pore diameter of the matrix and distort its overall shape, and thus needs to be addressed. Toward this goal, the objective of this study was to investigate the expression of SMA by synovial cells and to evaluate their contraction of collagen-glycosaminoglycan (GAG) scaffolds. Synovial membranes obtained from the knees (stifle joints) of six adult dogs were evaluated for the presence of SMA by immunohistochemistry. Cells isolated from the synovial tissue were expanded through seven passages in monolayer culture, with samples from each passage allocated for Western blot analysis of SMA. Cells from passage 4 were seeded into porous type I collagen-GAG matrices and cultured for 4 weeks. Synovial cell-mediated contraction of the scaffolds was determined by measuring the diameters of the cell-seeded scaffolds and nonseeded controls every other day. Synovium-derived cells cultured as micropellets or in collagen-GAG matrices were incubated in chondrogenic medium with and without fetal bovine serum and evaluated for chondrogenesis by type II collagen immunohistochemistry. Immunohistochemistry revealed the presence of SMA in some cells (less than 10% of the cells) in the intimal layer of synovium from four of the five animals analyzed. Western blot analysis demonstrated a regular increase in the amount of SMA in the synovium-derived cells with passage number. Synovial cell-mediated contraction of the collagen-GAG scaffolds reached a value of 43% of the original diameter after 4 weeks, comparable to that found with other musculoskeletal cell types. Incubation of micropellet cultures of synovium-derived cells with chondrogenic medium revealed trace amounts of type II collagen production by immunohistochemistry. The findings of this study indicate that control of SMA-enabled contraction may be important when employing synovial cells for cartilage repair procedures, and warrant further investigation into the physiological role of SMA expression in synovial cells.     

Adelta and C primary afferents convey dorsal root reflexes after intradermal injection of capsaicin in rats

Antidromic activity was recorded in anesthetized rats from single afferent fibers in the proximal ends of cut dorsal root filaments at the L(4-6) level and tested for responses to acute cutaneous inflammation produced by intradermal injection of capsaicin. This antidromic activity included low-frequency spontaneous firing and dorsal root reflex (DRR) discharges evoked by applying von Frey hairs to the skin of the foot. DRRs could be recorded from both small myelinated (Adelta) and unmyelinated (C) afferent fibers, as well as from large myelinated (Abeta) fibers. After capsaicin was injected intradermally into the plantar skin of the foot, a significant enhancement of DRR activity was seen in Adelta and C fibers but not in Abeta fibers, and this increase lasted for approximately 1 h. This study supports the hypothesis that centrally mediated antidromic activity in Adelta and C primary afferent fibers contributes to the development of neurogenic inflammation, presumably by release of inflammatory substances in the periphery.     

牦牛主动脉瓣叶的流变学性质

作者研究了牦牛主动脉瓣叶的单向拉伸和应力松弛行为。发现在生理应变范围内,试件的应力应变曲线斜率在纤维方向比其垂直方向约大20倍,瓣叶对应变速率不很敏感。在分析瓣叶的松弛行为时应用了冯元桢[9](1972)提出的松弛模型,根据实验结果,得到了牦牛主动脉瓣叶的归一化松弛函数。     

丹酰氯柱前衍生人尿液多胺高效液相色谱(HPLC)快速测定

建立了丹酰氯柱前衍生HPLC法测定人尿中多胺含量的方法。以己二胺为内标 ,uBondapak -C18(2 5 0× 4.6mm ,10um)为固定相 ,甲醇和水为流动相 ,梯度洗脱 ,柱温 5 0℃ ,流速 1ml/min ,荧光检测器测得腐胺 (PUT)、精脒 (SPD)和精胺(SP)三者回收率为PUT 97%、SPD 98%、SP 10 3% ,回归方程线性良好 ( 均大于 0 99) ,分析时间约 9min。该法简洁 ,快速 ,灵敏度高 ,重现性好 ,可有效分析人尿及其他生物样品中的多胺含量     

Characterization of a neurotoxigenic Clostridium butyricum strain isolated from the food implicated in an outbreak of food-borne type E botulism.

Neurotoxigenic Clostridium butyricum was isolated from the food implicated in an outbreak of clinically diagnosed type E botulism in China. PCR assay showed that the isolate (LCL 155) contained the type E botulinum toxin gene. This appears to be the first report of neurotoxigenic C. butyricum causing food-borne botulism.