PCR检测角膜内单疱病毒DNA的实验及临床研究

为了探索单疱病毒性角膜炎的发病机制和快速诊断ＨＳＫ。方法应用多聚酶链反应对感染的ＨＳＫ的２０只纯新西兰白兔和６０例ＨＳＫ患者的角膜进行了单疱病毒－１－ＤＮＡ检测。结果急性感染期的５只兔角膜和１２只人角膜均阳性；用稳定期４５ｄ的兔角供体行部分穿透性角膜移植术，术后５０ｄ１０只兔角膜中７只阳性，稳定期６个月－６年的１８只人角膜片，１２只阳性；３０例临床可疑ＨＳＫ角膜刮取物，２６例阳性；５只未感染ＨＳＫ     

国产鼻喷鲑鱼降钙素治疗骨质疏松性疼痛的疗效观察

目的观察国产鼻喷鲑鱼降钙素治疗骨质疏松性疼痛的疗效。方法采用随机分组对照设计。选择骨质疏松患者53例,随机分为两组,治疗组(30例)给予鼻喷鲑鱼降钙素,20u/次,1次/天,8周为1个疗程,停药后继续观察3周。对照组(23例)口服钙尔奇D片,1片/次,1次/天,共8周;采用国际惯用分级标准对疼痛予以评估。结果治疗组患者的疼痛明显改善,其总有效率为95%;在停药后缓解疼痛的作用仍可维持4周以上,Ⅲ度骨质疏松患者的治疗效果较Ⅰ度和Ⅱ度患者的效果差;对照组症状未见明显改善。结论用国产鼻喷鲑鱼降钙素治疗骨质疏松性骨痛,可明显缓解患者的疼痛症状。     

On the mechanism of increased potassium conductance by the potassium channel opener BRL 34915 in Isolated ventricular myocytes

The potassium conductance increased by BRL 34915 (BRL, cromakalim) was studied in single guinea pig ventricular myocytes by using a whole cell voltage-clamp technique. In control voltage-clamp recordings, the late current-voltage relation showed a distinct inward rectification. BRL (1–100 μM) shortened the action potential and diminished or abolished inward rectification but had no effect on the slope conductance and currents flowing during hyperpolarizing clamp steps. BRL did not decrease the slow inward current but accelerated the time constant of activation and amplitude of the outward current. Cd markedly decreased (0.2 mM) or abolished (0.4–0.6 mM) the slow inward current and BRL induced a faster outward shift of late current to a greater value. Glybenclamide (10 μM), a blocker of ATP-sensitive K⁺ channels, had little effect of its own on action potential, membrane currents, and I-V relation. However, in the presence of BRL, glybenclamide abolished BRL effects on action potential and currents and restored inward rectification. It is concluded that the mechanism by which BRL shortens the action potential is a faster growth of an outward current due to the reduction or abolition of the inward rectification of an ATP-dependent potassium channel. The reduction in force in non-isolated tissues appears to be an indirect result of the action potential shortening and not of a decreased slow inward current.     

Proanthocyanidin: a natural crosslinking reagent for stabilizing collagen matrices

While attempting to find a suitable crosslinking reagent for biopolymers, a naturally occurring proanthocyanidin (PA) obtained from grape seeds was selected to fix biological tissues. The cytotoxicity and crosslinking rate, reflected by the in vitro and in vivo degradation of fixed matrices has been studied. The shrinkage temperature of the fixed bovine pericardium increased from 66 to 86 degrees C. A cytotoxicity assay using fibroblast cultures revealed that PA is approximately 120 times less toxic than glutaraldehyde (GA), a currently used tissue stabilizer. In vitro degradation studies showed that fixed tissue was resistant to digestion by bacterial collagenase. Crosslinks between PA and tissues can be stabilized by decreasing the dielectric constant of the solution during storage. After subcutaneous implantation for periods ranging between 3 and 6 weeks, we found no apparent degradation of the GA- or PA-fixed tissues, whereas fresh tissue controls rapidly disintegrated. Beyond 6 weeks PA crosslinks began to degrade. More fibroblasts migrated and proliferated inside the PA-fixed implants compared with GA counterparts. Tissues crosslinked with PA manifested an enhanced collagen expression and deposition and did not calcify after implantation. GA, on the other hand, even after thorough rinsing continued to be cytotoxic, inhibited collagen synthesis and encouraged dystrophic calcification. Collagen matrices crosslinked with PA are expected to be of value in the design of matrices that will encourage cell ingrowth and proliferation, which are temporary in nature, and that are intended to regenerate or replace missing tissues, which can delay the biogradation of collagen. As such they should be of significant value in the emerging field of tissue engineering.     

The geographical distribution in Sweden of viruses belonging to the Russian spring-summer-louping Ill group

Conclusions NT antibodies to LI virus were found in the sera of Swedish cows from many parts of the country although only exceptionally in the north. The prevalence of positive specimens increased markedly towards the southeast. This geographic distribution apparently fits well with the occurrence of ticks in the country. An analysis, now in progress, of RSSE-LI antibodies in human cases of meningoencephalomyelitis seems to indicate a closely similar distribution of the human RSSE infections. It is thus obvious that the screening of cow sera for LI antibodies provides reliable information as to endemic regions of RSSE-LI-like viruses. There was nothing to suggest that nonspecific reactions occurred or impaired the results; in fact the very uneven geographic distribution of positive specimens, of high as well as low titers, should argue for specificity of the reaction.Aided by a grant from the Swedish National Association against Poliomyelitis.The skilful technical assistance of MissSiri Austrin, MissIngrid Lövhvist, MissBrita Gustafson and Mr.Nils Lundh is gratefully acknowledged.     

CYP17A1基因新突变致17α-羟化酶/17,20-裂解酶部分性缺陷症

目的研究1例17α-羟化酶/17,20-裂解酶部分性联合缺陷症患者CYP17A1基因突变特点,并结合患者的临床表现与基因突变类型初步探讨P450C17酶蛋白的结构与功能的关系。方法收集1例17α-羟化酶/17,20-裂解酶部分性联合缺陷症患者的临床资料及其亲属血标本,提取基因组DNA,设计7对引物扩增CYP17A1基因的8个外显子及外显子与内含子的连接区域,琼脂糖凝胶电泳鉴定PCR产物,产物胶回收后直接做为DNA双链模板测序。DNA双链模板不一致的PCR产物经克隆后测序。测序结果在核苷酸序列数据库进行比较分析。结果患者CYP17A1基因突变检测结果为5994-5995delAT/7541C>T复合杂合子。这两种突变均未见报道。推测5994-5995delAT导致I259H,274X,突变形成的截短蛋白质缺少血红素结合区域,因此是没有功能的;而通过人类P450C17酶计算机模型分析显示7541C>T导致的A398V远离酶的活性中心,推测突变可能使酶的活性减弱,而不是完全地丧失。患者临床表现为有自发不规则月经及轻度高血压、低血钾,结合激素测定结果提示肾上腺和性腺保留部分功能。因而患者的基因型与其临床表型是一致的。结论应进行突变P450C17酶的功能学研究来进一步明确结构改变对功能的影响。     

当归注射液对脑血栓患者花生四烯酸代谢产物和氧自由基水平的影响

目的 :了解当归注射液改善脑循环治疗脑血栓的临床效果。方法 :对 46例脑血栓形成患者应用当归注射液进行治疗 ,对比分析其治疗前后血浆前列环素 (PGI2 )、血栓烷A2 (TXA2 )及自由基水平。结果 :脑血栓形成患者TXA2 、丙二醛 (MDA)明显升高 ,超氧化物岐化酶 (SOD)明显降低。当归注射液治疗后上述改变明显减轻或恢复至正常组水平。结论 :当归注射液能有效调节花生四烯酸代谢产物和氧自由基水平 ,对治疗脑血栓效果明显。     

Characterization of an IgA receptor from group B streptococci: specificity for serum IgA

Some strains of group B streptococci express a cell surface protein which binds IgA. This report describes some properties of such an IgA receptor and compares it with a previously described IgA receptor from group A streptococci. The group B receptor was released in an almost pure form from bacteria incubated at elevated pH, and could be isolated by IgA-Sepharose affinity chromatography. The sequence of the N-terminal 19 amino acid residues was unique. The receptor preferentially binds IgA of human origin, as shown in immunoblotting experiments with purified IgA from nine different species. The affinity constant of the purified receptor for serum IgA was determined to be 3.5 x 10(8) M-1, but for secretory IgA it was too low to allow determination. This result indicates that secretory component and/or J chain interferes with the binding of IgA to this type of bacterial receptor, which may be one of the physiological functions of these polypeptides. A reduction in affinity was also observed for another complexed form of IgA, alpha 1-microglobulin-IgA. The group B receptor is antigenically unrelated to the IgA receptor from group A streptococci (protein Arp), but competitive inhibition experiments indicate that they bind to the same region in IgA. The implications of these findings, and the biological role of bacterial IgA receptors, are discussed.