RESUMO
In the decades to come,the increasing development of biotechnology may give a significant boost to bioweapons.Herein,we summarize bioterror attacks and critical laboratory accidents that have happened in the United States since the late 20th Century.Based on this description,we analyze its policies involved and the strategic shift the US government came up with.In view of with the current situation and potential risks of biotechnology,we make recommendations on the administration of Chinese biosafety laboratories and ways of responding to biothreat.
RESUMO
Ricin is a plant toxin isolated from the seed of the castor plant(Ricinus communis). As a typical II ribosome inactivating protein,ricin consists of two polypeptide chains named ricin toxin A chain(RTA)and ricin toxin B chain(RTB),linked via a disulfide bridge. RTB binds to both glycopro?tein and glycolipid at the surface of the target cell and mediates ricin to be endocytosed and transported retro?gradely to the endoplasmic reticulum. After being reduced and retrotranslocated to the cytosol,RTA mediates its toxicity due to its activity of a RNA N- glycosidases. Aside from its main toxic effect of protein synthesis inhibition,ricin also displays other properties that contribute to its toxicity such as inducing apoptosis,cytokine secreting and peroxidation. Ricin is stable and can be easily isolated. It has many routes of intoxication with no specific antidotes. Due to its natural abundance,remarkable toxicity,and the potential to be used in biological warfare as well as terrorist attacks,ricin has been classified as a Category B biothreat agent. Here we reviewed its history as a biothreat agent,constitu?tion,intoxication mechanism,detection methods and the development of specific antitodes.