【来源】Science, Vol 304, Issue 5674, 1097 , 21 May 2004
【原文】What a difference a year makes. This time in 2003, severe acute respiratory syndrome (SARS) was spreading like wildfire, and researchers barely knew what they were up against. Today, the disease is gone, and researchers are elucidating some of its most intimate details. At a recent meeting* here, they reported progress--and some setbacks--in everything from molecular biology to epidemiology to drug development.
Only four mini-outbreaks have occurred since SARS was vanquished worldwide. Three of those were the result of labs failing to contain the virus (Science, 30 April, p. 659)--a record that many scientists fear may erode public support for research on SARS and other agents. "It's terrible news for all of us," says Luis Enjuanes of the Universidad Autonoma in Madrid.
The one natural outbreak since last summer, which sickened four people in the southern province of Guangdong in December and January, has provided intriguing new clues into the virus's epidemiology. Genomic analysis of the virus isolated from one of the patients showed that it was highly similar to a virus isolated from a masked palm civet, bolstering suspicions that civets transmit the disease to humans. But researchers do not think civets are the elusive natural hosts of the SARS virus because, as another study showed, civets suffer symptoms when experimentally infected. A natural host would normally be symptom-free.
Adding another wrinkle to SARS's confusing epidemiology, Lin Lifeng of the Center for Disease Control and Prevention in Guangzhou showed that the genetic signature of the virus has been detected in the lungs of three out of six rats caught in the building where one of the four recent patients lived. The patient had disposed of a dead rat shortly before getting sick, Lin said, suggesting that the animals may be carriers just like civets. If true, that would pose the specter of a continuous urban source of new infections, says Enjuanes, but much more study is needed. The researchers have not shown that the virus replicates in or is transmitted among rats, for instance.
On the vaccine front, meanwhile, news was sobering. A flurry of vaccine studies began almost immediately after last year's outbreak, and China has embarked on human trials. But experts fear that some vaccines might worsen the disease rather than prevent it, a phenomenon seen in cat coronavirus vaccines (Science, 13 February, p. 944). Now a study by Cao Jingxin of the National Microbiology Laboratory in Winnipeg, Canada, and his colleagues adds weight to those worries. The SARS virus, the group found, can cause mild liver inflammation in ferrets; that damage was much more serious if animals were first given a candidate SARS vaccine based on a vaccinia virus. "This is another warning sign," Cao says: "Be very careful before you put anything into large numbers of humans."
In terms of therapeutics, virologist Berend Jan Bosch of Utrecht University, the Netherlands, showed that peptides resembling part of the virus's "spike" protein can inhibit the fusion of the virus and its host cell in vitro. And a team at the University of Leuven, Belgium, reported that a compound that produces nitric oxide inhibits virus replication as well.
But without new outbreaks, researchers say it's hard to see a market for new therapeutics. Even well-established drugs that show promise against SARS may not get their chance. A recent study, for instance, showed that one type of interferon- could prevent a SARS-like disease in monkeys (Science, 27 February, p. 1273). According to in vitro studies presented by Lawrence Stanton of the Genome Institute of Singapore, several other commercially available varieties of interferon- and - showed a "nice potent inhibition of the SARS virus" as well. "You'd think the interferon companies would be very interested" in planning a clinical trial, Stanton said. Not so, he discovered recently: "They have adopted a wait-and-see attitude."
【翻译】SARS爆发一年后，世界上有什么变化呢！在2003年的这个时候，严重急性呼吸系统综合症（SARS）像野火一样蔓延开来，一时间研究人员手足无措。今天，SARS已经去了，研究人员正在试图阐释它的一些细节问题。在最近的一次会议上，SARS研究人员报告了最新的进展和研究中的挫折，其涉及的领域包括分子生物学、流行病学以及新药的开发。
自从在全世界范围内SARS被征服以后，仅有四次小规模的爆发。其中三次是由于实验室对病毒的保存不当引起的，这也是许多科学家害怕的，因为这会损害公众对SARS及其相关研究的支持。“这对我们任何人来说都是非常可怕的消息”，马德里Autonoma大学的Luis Enjuanes说。
从去年夏天以来，仅在去年12月至今年1月间，中国南方的广东省发生一次自然爆发，共有4人被感染。这次爆发给流行病学提供了有趣的新线索。从一患者体内得到的病毒的基因组学分析表明它与假脸狸猫身上分离的病毒非常相似，这支持了狸猫将病毒传播给人的假设。但是研究人员并不认为狸猫是SARS病毒的自然宿主，因为另一研究表明，狸猫在实验条件下感染病毒后也有相应的发病症状，而通常自然宿主是不会有感染症状的。 2 1 2 下一页 尾页
【原文】What a difference a year makes. This time in 2003, severe acute respiratory syndrome (SARS) was spreading like wildfire, and researchers barely knew what they were up against. Today, the disease is gone, and researchers are elucidating some of its most intimate details. At a recent meeting* here, they reported progress--and some setbacks--in everything from molecular biology to epidemiology to drug development.
Only four mini-outbreaks have occurred since SARS was vanquished worldwide. Three of those were the result of labs failing to contain the virus (Science, 30 April, p. 659)--a record that many scientists fear may erode public support for research on SARS and other agents. "It's terrible news for all of us," says Luis Enjuanes of the Universidad Autonoma in Madrid.
The one natural outbreak since last summer, which sickened four people in the southern province of Guangdong in December and January, has provided intriguing new clues into the virus's epidemiology. Genomic analysis of the virus isolated from one of the patients showed that it was highly similar to a virus isolated from a masked palm civet, bolstering suspicions that civets transmit the disease to humans. But researchers do not think civets are the elusive natural hosts of the SARS virus because, as another study showed, civets suffer symptoms when experimentally infected. A natural host would normally be symptom-free.
Adding another wrinkle to SARS's confusing epidemiology, Lin Lifeng of the Center for Disease Control and Prevention in Guangzhou showed that the genetic signature of the virus has been detected in the lungs of three out of six rats caught in the building where one of the four recent patients lived. The patient had disposed of a dead rat shortly before getting sick, Lin said, suggesting that the animals may be carriers just like civets. If true, that would pose the specter of a continuous urban source of new infections, says Enjuanes, but much more study is needed. The researchers have not shown that the virus replicates in or is transmitted among rats, for instance.
On the vaccine front, meanwhile, news was sobering. A flurry of vaccine studies began almost immediately after last year's outbreak, and China has embarked on human trials. But experts fear that some vaccines might worsen the disease rather than prevent it, a phenomenon seen in cat coronavirus vaccines (Science, 13 February, p. 944). Now a study by Cao Jingxin of the National Microbiology Laboratory in Winnipeg, Canada, and his colleagues adds weight to those worries. The SARS virus, the group found, can cause mild liver inflammation in ferrets; that damage was much more serious if animals were first given a candidate SARS vaccine based on a vaccinia virus. "This is another warning sign," Cao says: "Be very careful before you put anything into large numbers of humans."
In terms of therapeutics, virologist Berend Jan Bosch of Utrecht University, the Netherlands, showed that peptides resembling part of the virus's "spike" protein can inhibit the fusion of the virus and its host cell in vitro. And a team at the University of Leuven, Belgium, reported that a compound that produces nitric oxide inhibits virus replication as well.
But without new outbreaks, researchers say it's hard to see a market for new therapeutics. Even well-established drugs that show promise against SARS may not get their chance. A recent study, for instance, showed that one type of interferon- could prevent a SARS-like disease in monkeys (Science, 27 February, p. 1273). According to in vitro studies presented by Lawrence Stanton of the Genome Institute of Singapore, several other commercially available varieties of interferon- and - showed a "nice potent inhibition of the SARS virus" as well. "You'd think the interferon companies would be very interested" in planning a clinical trial, Stanton said. Not so, he discovered recently: "They have adopted a wait-and-see attitude."
【翻译】SARS爆发一年后，世界上有什么变化呢！在2003年的这个时候，严重急性呼吸系统综合症（SARS）像野火一样蔓延开来，一时间研究人员手足无措。今天，SARS已经去了，研究人员正在试图阐释它的一些细节问题。在最近的一次会议上，SARS研究人员报告了最新的进展和研究中的挫折，其涉及的领域包括分子生物学、流行病学以及新药的开发。
自从在全世界范围内SARS被征服以后，仅有四次小规模的爆发。其中三次是由于实验室对病毒的保存不当引起的，这也是许多科学家害怕的，因为这会损害公众对SARS及其相关研究的支持。“这对我们任何人来说都是非常可怕的消息”，马德里Autonoma大学的Luis Enjuanes说。
从去年夏天以来，仅在去年12月至今年1月间，中国南方的广东省发生一次自然爆发，共有4人被感染。这次爆发给流行病学提供了有趣的新线索。从一患者体内得到的病毒的基因组学分析表明它与假脸狸猫身上分离的病毒非常相似，这支持了狸猫将病毒传播给人的假设。但是研究人员并不认为狸猫是SARS病毒的自然宿主，因为另一研究表明，狸猫在实验条件下感染病毒后也有相应的发病症状，而通常自然宿主是不会有感染症状的。 2 1 2 下一页 尾页