Emerging diseases. Malaysian researchers trace Nipah virus outbreak to bats

Scientists are a step closer to unraveling a medical mystery that killed 105 people in Malaysia last year and destroyed the country's pig industry. The Nipah virus, which caused the disease, most likely originated in a native fruit bat species, Malaysian researchers reported here at a meeting last week. They say the findings will help Malaysian health authorities prevent future outbreaks of the Nipah virus. Others see the case as an argument for expanding research into infections that can leap the boundary between animals and humans.     

一种新型的人畜互传病—立百病

立百病（Nipah disease）是1998年在马来西亚首次发现的一种严重危害猪和人类的病毒性人畜共患病。1998年10月至1999年5月期间，立百病在马来西亚的猪群和人群中大规模暴发流行，并殃及到新加坡，导致105人死亡，116万头猪被捕杀。2000年2月以来，该病再度在马来西亚流行，到目前为止已有1人死亡，1728头猪被捕杀，引起该国和周边国家的广泛关注。一、病 原 学目前对立百病毒了解还不多。起初认为此病毒为日本脑炎病毒，但所有的病毒性脑炎病例中只有15％被证实为日本脑炎，其余85％的病例其病因无法确定。1999年2月，从本病患者血清和病死…     

Genome sequencing. Closing in on a deadly parasite's genome

Extremely difficult to decipher, the genome of Plasmodium falciparum, the most virulent malaria parasite, is already providing targets for new drugs. Next project: the mosquito genome.     

鹅副黏病毒分离株的生物学特性鉴定

从江苏某地患病鹅群的脑、脾病料组织中分离到1株病毒.经过试验鉴定,该毒株具有血凝性,且可被ND标准阳性血清所抑制和中和,而不能被AI(H5亚型与H9亚型)和EDS-76标准阳性血清抑制.人工感染雏鹅,引起100%的发病和死亡,并与自然病例有相似的症状和病变.该野外分离病毒的鸡胚半数致死量为每0.1 mL含有10-9.16,最小致死量病毒致死鸡胚的平均时间(MDT)为58.8 h,1日龄SPF鸡脑内接种致病指数(ICPI)为1.41,电境观察病毒颗粒呈多形性,粒径100～200 nm,有囊膜和纤突.综合上述结果得出,该野外分离病毒为鹅副黏病毒(GPMV)强毒力毒株.人工感染发病的鹅和鸡其临床症状及病理变化均与自然发病鹅的相类似.     

一株分离的鹅副粘病毒的毒力、致病性和传播方式的研究

采用血清学、生物学方法,从一群病死鹅中分离到1株鹅副粘病毒(GPMV)。血清学鉴定表明该分离病毒为禽副粘病毒-I型(PMV-I);毒力测定显示分离病毒GPMV毒力与鸡F48E9毒株的毒力相似;F基因裂解位点序列的分析表明该分离病毒GPMV融合蛋白F裂解位点氨基酸序列为112K-R-Q-K-R-F117。分离病毒GP-MV攻击不同新城疫(ND)抗体水平的雏鸡、蛋鸡和鹅,结果显示分离病毒GPMV与鸡ND强毒株的致病性相似,既可引起鸡、鹅典型的ND,也可引起非典型的ND,其发病率、死亡率、临床症状和病理变化与鸡、鹅本身的免疫状况有关。经不同途经感染试验表明,分离病毒GPMV可通过呼吸道、消化道和直接接触等方式传播给鸡。     

Potato spindle tuber virus: a plant virus with properties of a free nucleic acid

Infectious entities, extractable, with phosphate buffer, from tissue infected with potato spindle tuber virus and inciting symptoms on tomato that are typical of this virus, have properties incompatible with those of conventional virus particles. The infectious particles sediment in sucrose density gradients at approximately the same rate as particles with a sedimentation coefficient of 10S, are insensitive to treatment with organic solvents, and can be concentrated by ethanol precipitation. Treatment with phenol changes neither their infectivity nor their sedimentation properties. Infectivity is insensitive to deoxyribonuclease, but at low ionic strength it is sensitive to ribonuclease. At high ionic strength, infectivity partially survives incubation with ribonuclease. These properties, as well as elution patterns from columns of methylated serum albumin, suggest that the extractable infectious agent may be a double-stranded RNA.