我国家畜猝死症的研究进展

家畜猝死症又称暴死症或急性死亡综合症,它的病因是多方面的,但普遍认为魏氏梭菌感染或与其他病原混合感染是其致病的主要原因.目前,国外对魏氏梭菌外毒素的结构和生物活性研究比较透彻,对魏氏梭菌外毒素的防治研究主要集中在免疫预防方面;国内的研究工作主要是借鉴国外的研究技术和方法,从基因水平上研究了魏氏梭菌主要致死性毒素保护性抗原基因的克隆和表达.综述了我国家畜猝死症的研究进展.     

PRRSV辽宁分离株ORF3基因的克隆与序列分析

以辽宁地区某猪场猪繁殖与呼吸综合征(PRRS)病料为材料,采用RT-PCR方法特异性扩增编码猪繁殖与呼吸综合征病毒(PRRSV)GP3蛋白的ORF3基因全长cDNA,结果该分离株ORF3基因cDNA编码区长765bp,可编码254个氨基酸残基,与美洲型代表株VR-2332和欧洲型代表株LV进行同源性比较,氨基酸同源性分别为87.8%和54.5%,因此推测辽宁分离株属于美洲型。     

低分子右旋糖酐加速尿对肾病综合征患者利尿作用与高凝状态的影响

目的 :探讨低分子右旋糖酐加速尿对肾病综合征 (NS)患者利尿作用与高凝状态的影响。方法 :用随机对照的方法 ,对新入院的住院NS患者使用低分子右旋糖酐加速尿治疗 ,观察其治疗前后的尿量、体重 ,并测定其治疗前后血流变学指标 ,血小板聚集功能、纤溶活性等指标。结果 :NS患者经用低分子右旋糖酐加速尿治疗后较治疗前尿量明显增加 ,体重明显下降 (P <0 .0 1) ,治疗后观察组的尿量、体重与对照组比较差异也有显著性 (P <0 .0 5 )。观察组血浆粘度、全血粘度(高切、低切 )、血栓形成系数、血小板聚集治疗后较治疗前明显好转 (P <0 .0 1) ;对照组治疗前后这些指标无明显变化 (P >0 .0 5 ) ;治疗后观察组与对照组比较差异有显著性 (P <0 .0 5 ,0 .0 1)。组织纤溶酶原激活物 (t PA)、纤溶酶原活化剂抑制物(PAI)、血浆α2 抗纤溶酶 (α2 AP)治疗前后无明显变化 ,与对照组相比差异无显著性 (P >0 .0 5 )。结论 :使用低分子右旋糖酐和速尿联合治疗NS水肿 ,既可达到利尿消肿的目的 ,又有抗凝、降低高凝状态的作用     

132例原发性干燥综合征抗SSA、抗SSB抗体的检测与系统性损害

目的：分析132例原发性干燥综合征(PSS)系统损害与抗SSA、抗SSB抗体之间的关系。方法：采用对流免疫电泳法(CIEE)和免疫印迹(IBT)法检测132例PSS患者血清中抗SSA、抗SSB抗体。结果：PSS患者抗SSA、抗SSB抗体阳性组出现系统性损害发生率75．0％，而阴性组仅为16．7％，两组差异有显著性(P＜0．01)。结论：抗SSA、抗SSB抗体与PSS的系统性损害密切相关，它代表了不同的临床类型，对PSS病情临床评价具有重要的指导意义。     

Secure pacemaker fixation critical for prevention of Twiddler's syndrome

A two year old, female spayed border collie presented three weeks after permanent pacemaker implantation for weakness, lethargy and collapse. Electrocardiogram documented complete (3^rd degree) atrioventricular (AV) block, the absence of pacing and a ventricular escape rhythm. Thoracic radiographs revealed retraction and dislodgement of the passive fixation lead from the right ventricular apex. During a procedure to reposition the lead, it was noted that lead retraction had resulted from rotation of the generator with twisting and entanglement of the lead on itself and around the generator, a complication recognized in human patients as “Twiddlers syndrome”. The pacemaker lead was removed, a new lead securely placed at the right ventricular apex, and the generator was secured into a revised subcutaneous pocket. Pacing was re-established and the Twiddler's syndrome has not reoccurred.     

病原感染条件下中国对虾二倍体和三倍体血液学变化

以热休克诱导获得中国对虾三倍体，通过口服或注射的方式对二倍体和三倍体中国对虾进行了白斑综合征病毒(WSSV)和鳗弧菌感染实验，研究了病原感染前后二倍体和三倍体中国对虾血液学的变化并首次报道了三倍体中国对虾血细胞的组成。实验结果表明：三倍体和二倍体中国对虾均对WSSV敏感，三倍体未显示出明显的抗性。WSSV感染4d后，对虾外周循环系统的血细胞数量明显减少，三倍体和二倍体对虾血细胞数量均降为对照组的10％左右。对虾血细胞组成发生变化，大颗粒细胞明显减少，小颗粒细胞相应增加，而透明细胞所占比例基本不变；大颗粒细胞和小颗粒细胞内颗粒物质均有所减少，出现空泡或细胞外突起等异常结构。注射鳗弧菌感染后两种对虾的血细胞数量均有所减少，血细胞数量的减少与弧菌的注射量呈正相关关系：三倍体中国对虾血细胞组成与二倍体相似，但其密度仅为二倍体的40％左右：本研究结果为三倍体对虾抗逆特性的研究提供了一定依据和参考。     

A synthetic antibacterial peptide from Mytilus galloprovincialis reduces mortality due to white spot syndrome virus in palaemonid shrimp

White spot syndrome virus (WSSV) isolated from Penaeus monodon was found to be highly infective for the western Mediterranean shrimp, Palaemon sp. Using polymerase chain reaction (PCR), it was demonstrated that such shrimp are not naturally carriers of WSSV. Following challenge with virus, mortality reached 100% 3.5-4 days after injection at 22 degrees C. Incubation of infected shrimp at 10 degrees C totally suppressed the mortality which rapidly developed when shrimp were returned to 18 or 22 degrees C. Preincubation of WSSV with mature synthetic mytilin significantly reduced shrimp mortality with a 50% efficient dose of about 5 microM. Survival of shrimp was not due to the development of an active mechanism of defence as re-injection of WSSV produced the same mortality pattern. Mortality was probably due to WSSV replication as dot blot failed to detect viral DNA in the injection sample but was positive 1 day post-injection. Protection by mytilin was by interaction at the virus level, preventing replication as no WSSV nucleic acid was detected by PCR even after 7 days in shrimp injected with WSSV preincubated with 10 or 50 microM mytilin.     

Yellow head-like viruses affecting the penaeid aquaculture industry: a review

This review focuses on relevant scientific information regarding the current knowledge of the yellow head complex viruses, yellow head virus and gill‐associated virus. The yellow head complex viruses have been problematic within the aquaculture industry for over 10 years and still retain their research topicality. Presently, there are numerous research papers from different journals covering the identification, disease expression and spread, pathogenesis, detection, morphology, genomic sequence and protein profiles of the yellow head complex viruses. Indeed, there has been no extensive review to compare these studies, and as a corollary, to assess flaws in contemporary research and knowledge. Additionally, the yellow head complex viruses rank within the top four prawn viruses with respect to disease impact and economic loss. This review collectively reports on all the findings and current methods of research and aims to identify weak areas of research where conclusions have been unjustifiably drawn and furthermore to elucidate areas that have a gap of knowledge.     

乳山对虾养殖场白斑综合征病毒(WSSV)调查研究

2002年采用PCR-核酸探针斑点杂交法检测了乳山对虾养殖场1000余份样品携带白斑综合征病毒(WSSV)的情况。结果显示,639例对虾样品中阳性检出率为26·6%;77例蟹类样品中阳性检出率为18·2%;266例浮游动物样品中阳性检出率为38·3%,3~9月份浮游动物阳性率呈下降趋势,消毒后水体中浮游动物的阳性率仍很高;30例贝类样品检测均为阴性;204例底泥样品中,阳性检出率为17·6%,22例抽滤海水样品检测均为阴性。结果表明,虾、蟹类在传播WSSV中起着重要作用,贝类、海水传播WSSV的可能性很小,浮游动物、底泥在传播WSSV中的作用和机制应引起高度重视。