农业生产上几种重要的赤霉属真菌研究进展

赤霉属真菌大多是农业生产上具有破坏性的植物病原真菌。选取几种在农业生产上重要的赤霉属真菌来阐述该属在系统发生,生物学和化学上的多样性,并且比较了它们在分类学、遗传学、植物病理学和真菌毒理学方面的差异。虽然它们是非常近缘的赤霉属各种,但在繁殖方式、地理分布、寄主范围、植物致病机理、毒素和其他生物活性代谢物的产生方面都有所不同。     

Herpesviral abortion in domestic animals

Abortion or neonatal disease may follow infection with several α, β and γ-herpesviruses. The α-herpesvirus, equid herpesvirus-1 (EHV-1), causes single or epizootic abortions or neonatal deaths in equids, and the closely related virus EHV-4 causes sporadic equine abortions. In cattle, the α-herpesviruses, bovine herpesvirus-1 (infectious bovine rhinotracheitis virus) and bovine herpesvirus-5 (bovine encephalitis virus), and a γ-herpesvirus, bovine herpesvirus-4, have all been implicated as causes of abortion. In pigs, suid herpesvirus-1 (SHV-1: pseudorabies virus), an α-herpesvirus, and SHV-2 (porcine cytomegalovirus), a β-herpesvirus, each cause abortion or neonatal piglet losses. Caprine herpesvirus-1, canine herpesvirus and feline herpesvirus-1, all α-herpesviruses, cause abortions or neonatal deaths in goats, dogs and cats, respectively. This review discusses the pathogenesis, pathology and laboratory diagnosis of these herpesviral abortions and neonatal diseases, with an emphasis on experimental studies of each disease. Alternative reviews covering other aspects of each infection, such as the genetic and antigenic structure of the viruses, host immune responses and approaches to vaccination and disease control are indicated at appropriate points in the text. nts in the text.     

Inclination and Anteversion of Collum Femoris in Hip Dysplasia and Coxarthritis

Madsen, J.S. and E. Svalastoga: Inclination and anteversion of collum femoris in hip dysplasia and coxarthritis. Acta vet. scand. 1994, 35, 115-119.–Femoral neck angles were measured radiographically in 41 dogs examined for hip dysplasia. Steep femoral neck inclination was found to be a phenomenon of hip dysplasia and coxofemoral joint laxity. The altered biomechanics of a steep femoral neck inclination may be a factor in the pathogenesis of hip dysplasia and secondary osteoarthritis.     

水貂阿留申病发病机理的研究进展

水貂阿留申病是由阿留申病病毒引起的一种可对水貂养殖业造成严重损失的传染病。该病困扰动物医学界多年 ,始终未得到攻克。近年来随着分子生物学技术的发展 ,国内外学者对该病分子水平的发病机理有了更多的认识 ,研究内容主要集中在与水貂阿留申病发病密切相关的抗病毒抗体、病毒核酸的晚启动子P3 6及其顺式作用元件(cis acting)、结构蛋白VP2等方面。文章对以上研究进展进行了详细的归纳总结与分析 ,并在此基础上提出了尝试使用反义RNA或干扰RNA对该病进行预防、治疗的设想 ,以期今后对阿留申病的继续深入研究能有所帮助。     

脓毒血症致急性肾损伤及右美托咪定保护作用机制研究进展

脓毒血症可造成机体多器官、组织继发性损伤,其中肾脏是最易受其侵害脏器之一。脓毒血症致急性肾损伤(Septic acute kidney injury,SAKI)是病患预后不良、高死亡率主要原因,但SAKI发病机制、治疗药物作用靶位以及保护作用尚不明确。以往认为SAKI主要由肾脏血流动力学改变导致肾小管上皮细胞坏死造成,近年研究发现,血流动力学改变并非其最主要病理生理机制,还包括由内毒素介导的炎症反应、肾脏细胞凋亡、凝血功能异常致肾小球内栓塞以及坏死细胞造成肾小管阻塞等。右美托咪定(Dexmedetomidine,DEX)对SAKI具一定保护作用,其保护机制尚无定论,多集中在抑制肾脏炎性因子产生,减轻氧化应激反应及细胞凋亡等方面。DEX具体分子作用机制和药效靶位尚不清楚,有待进一步研究。     

Rabies – epidemiology,pathogenesis, public health concerns and advances in diagnosis and control: a comprehensive review

Rabies is a zoonotic, fatal and progressive neurological infection caused by rabies virus of the genus Lyssavirus and family Rhabdoviridae. It affects all warm-blooded animals and the disease is prevalent throughout the world and endemic in many countries except in Islands like Australia and Antarctica. Over 60,000 peoples die every year due to rabies, while approximately 15 million people receive rabies post-exposure prophylaxis (PEP) annually. Bite of rabid animals and saliva of infected host are mainly responsible for transmission and wildlife like raccoons, skunks, bats and foxes are main reservoirs for rabies. The incubation period is highly variable from 2 weeks to 6 years (avg. 2–3 months). Though severe neurologic signs and fatal outcome, neuropathological lesions are relatively mild. Rabies virus exploits various mechanisms to evade the host immune responses. Being a major zoonosis, precise and rapid diagnosis is important for early treatment and effective prevention and control measures. Traditional rapid Seller's staining and histopathological methods are still in use for diagnosis of rabies. Direct immunofluoroscent test (dFAT) is gold standard test and most commonly recommended for diagnosis of rabies in fresh brain tissues of dogs by both OIE and WHO. Mouse inoculation test (MIT) and polymerase chain reaction (PCR) are superior and used for routine diagnosis. Vaccination with live attenuated or inactivated viruses, DNA and recombinant vaccines can be done in endemic areas. This review describes in detail about epidemiology, transmission, pathogenesis, advances in diagnosis, vaccination and therapeutic approaches along with appropriate prevention and control strategies.     

猪脑心肌炎病毒感染对iNOS mRNA转录水平的影响

为研究iNOS在猪脑心肌炎病毒(EMCV)致病机制中的作用,本研究将猪源EMCV GXLC株人工感染小鼠、仔猪,观察临床症状和病理变化,检测心、脑组织中iNOS mRNA转录水平。试验结果表明,小鼠和仔猪感染EMCV后均出现明显的临床症状、剖检及组织病理学变化显示心、脑组织的病理炎症分值显著增加;心、脑组织中的iNOS mRNA转录水平显著上调,并且转录水平上调的峰值与感染小鼠、仔猪出现明显临床症状、严重病理损害及小鼠死亡高峰存在明显的时间相关性,与心、脑组织的病理炎症分值成线性正相关。表明组织中iNOS的过量表达与感染动物的发病和死亡密切相关,iNOS在EMCV致病机制中发挥重要作用。     

利用gusA基因在水稻组织中示踪和定量水稻白叶枯病菌的方法

 水稻白叶枯病菌(Xanthomonas oryzae pv. oryzae, Xoo)从自然孔口水孔或者伤口处侵入水稻叶片,在维管束中定殖、繁殖和扩展,引起典型的叶枯症状。可视化这个动态的病程过程和快速定量水稻组织中细菌的群体是Xoo-水稻互作研究中亟待突破的技术难点。本研究在PXO99^A菌株中表达gusA基因,将其置于lacZ启动子、hrpX启动子和不含有(T₁)₄终止子的hrpX启动子下,构建了3个示踪菌株PXO99^A_GUSRBS、PXO99^A_GUSX和PXO99^A_GUSX-。水稻上毒性测定结果显示,这3个示踪菌株与野生型PXO99^A展现相同的毒性。利用示踪菌株,通过注射接种法,能够观察到Xoo在水稻维管束中定殖和扩展的动态变化;通过喷雾接种法,能够观察到Xoo从叶尖或者叶缘侵入水稻叶片引起发病的特性;发现PXO99^A_GUSX和PXO99^A_GUSX-比PXO99^A_GUSRBS能够更加灵敏地反映这些病程。同时发现,PXO99^A_GUSRBS的细菌数量与受其侵染的水稻组织的GUS活性显著正相关。本研究也评价了利用GUS活性测定法精确和快速地定量水稻组织中细菌群体的可行性。以上结果表明这套GUS系统是非常有效的,能够示踪病原菌的侵染过程和监测细菌在水稻组织中的群体数量,这将为Xoo-水稻互作研究提供有力的技术支持。     

Pleurotus ostreatus对线虫作用机理的研究

 本文详细地研究了粗皮侧耳(Pleurotus ostreatus)对线虫(Panagrellus redivivus)的致病过程、线虫感病症状及菌丝与线虫的相互作用。探明了粗皮侧耳对线虫致病的实质是杀主寄生,菌丝分泌的毒素首先将线虫击倒并杀死,然后菌丝从线虫体孔侵入,或靠酶和机械力的作用从表皮侵入,最后消解、吸收和利用线虫。一般菌丝与线虫接触1~5min线虫被击倒,20~30min卵和幼虫解体,4~6h成虫死亡,12h后菌丝侵入虫体营腐生生活。菌丝也可不侵染线虫,仅靠毒素将线虫杀死,在酶的协同作用下将线虫分解,直接吸收利用线虫。若菌丝分泌的毒素不足以杀死线虫,纵然菌丝与线虫充分接触也不能侵染活线虫。试验还表明,该菌平板培养产生的毒素,除去菌丝也能杀死线虫。     

尖孢镰孢菌致病机理及相关致病基因研究进展

尖孢镰孢菌是农作物和园艺作物上为害最严重的土传病原物之一,目前仍缺乏有效的防治措施,而明确其致病机理被认为是开发新的且有效的防治技术的重要基础。本文从尖孢镰孢菌产生毒素、尖孢镰孢菌细胞壁降解酶、尖孢镰孢菌对寄主的定植及对植物防卫物质的解毒等角度阐述了尖孢镰孢菌致病机理,总结了近几年克隆的15个尖孢镰孢菌致病相关基因、基因功能以及筛选致病基因的策略;概括了研究致病机理和致病基因的意义。