Scripps research scientists: Compounds show significant promise against potential bioweapon toxinsFebruary 06, 2007Small molecules could fill therapy gap in nation's bioterrorism defense Because of the high cost and limited applicability of currently available treatments, the newly identified compounds have the potential to fill the existing therapy gap and to provide protection against a bioterrorism attack using the toxin. The study is being published the week of February 5 in an online edition of the Proceedings of the National Academy of Sciences. "Our study is an important milestone in the fight against biological terrorism," said Kim Janda, a Scripps Research scientist who led the study. "These small molecules are the first to show efficacy against this neurotoxin in animal models. Equally important, both have surprisingly simple structures, so their biological activity can be readily optimized. With their different modes of action, they could easily be developed as part of a potent 'cocktail' therapy." Janda said he expects to develop more small molecule candidates as potential botulism treatments. Botulinum neurotoxins, which cause the disease botulism, are some of the most toxic substances known to scientists. One subtype, botulinum neurotoxin A, is a 100 billion times more potent than cyanide and relatively easy to produce, making it a potential biological weapon. Using a multifaceted screening approach, Janda and his colleagues identified the two compounds and tested their efficacy in both cell-based assays and in mice exposed to the toxin. One compound extended survival time by 36 percent (from 484 minutes to 659 minutes) a remarkable achievement considering its simple structure. Moreover, 16 percent of the animals treated with the second molecule survived with no obvious symptoms of botulism. No significant side effects were observed with either molecule. Janda pointed out that the two compounds showed surprisingly little activity in cellular assays, suggesting that these standard cell-based screening methods may miss promising therapeutic candidates. "Our study showed no correlation between cellular activity and in vivo efficacy," Janda said, "which is highly unusual. Clearly, cell-based assays do not provide all the necessary information—animal-based studies are still an essential part of the discovery process. These findings validate our multidisciplinary screening approach to identify unrecognized chemical structures as potential treatments." While research efforts aimed at finding treatments for bioterrorism agents have increased dramatically since September 11, 2001, remarkably few have emerged. There are currently no small chemical molecules approved for treatment of botulism. Botulism is a serious but extremely rare illness. There are seven related botulinum neurotoxins (A through G), although each acts differently and only four attack humans. The toxins kill through paralysis of the respiratory muscles. After attaching themselves to receptors on the neuronal surface—primarily muscle controlling motor neurons activated by acetylcholine, a neurotransmitter—the toxins block the release of acetylcholine proteins, inducing paralysis. Approximately 110 cases of botulism are reported each year in the United States. Scripps Research Institute |
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| Related Botulism Current Events and Botulism News Articles New explanation for nature's hardiest life form Got food poisoning? The cause might be bacterial spores, en extremely hardy survival form of bacteria, a nightmare for health care and the food industry and an enigma for scientists. UI chemists' DNA biosynthesis discovery could lead to better antibiotics Combating several human pathogens, including some biological warfare agents, may one day become a bit easier thanks to research reported by a University of Iowa chemist and his colleagues in the April 16 issue of the journal Nature. Scientists discover new chemical reaction for DNA production in bacteria and viruses A team of researchers has discovered a new chemical reaction for producing one of the four nucleotides, or building blocks, needed to build DNA. Nose-spray vaccine against botulism effective in first tests A preclinical study found a new nasal spray vaccine to provide complete protection against a major botulism toxin, according to a study published today in the Nature journal Gene Therapy. Scientists Reveal Structure of New Botulism Nerve Toxin Subtype cientists at the U.S. Department of Energy's (DOE) Brookhaven National Laboratory have determined the atomic-level structure of a third subtype of botulinum neurotoxin - a deadly toxin produced by certain bacteria that causes the disease botulism, and is also used in cosmetic and therapeutic applications such as reducing wrinkles and calming a hyperactive bladder. Advance offers revolution in food safety testing Microbiologists at Oregon State University have developed a new technology to detect illness-causing bacteria - an advance that could revolutionize the food industry, improving the actual protection to consumers while avoiding the costly waste and massive recalls of products that are suspected of bacterial contamination but are perfectly safe. Even before tomato warning, many Americans lacked confidence in the food safety system A new national study conducted by the Harvard School of Public Health Project on the Public and Biological Security finds that, in spite of a number of food safety incidents in recent years, most Americans remain confident that the food produced in the United States is safe. However, many have concerns about the safety of imported food produced in some other countries. Researchers develop new ultrasensitive assay to detect most poisonous substance known Scientists at City of Hope and the California Department of Public Health have developed a new ultrasensitive assay to detect botulinum neurotoxin. Scientists Determine Drug Target for the Most Potent Botulinum Neurotoxin Botulinum neurotoxin -- responsible for the deadly food poisoning disease botulism and for the beneficial effects of smoothing out facial wrinkles - can also be used as a dreaded biological weapon. Researchers discover pathway to cell size, division Organisms precisely regulate cell size to ensure that daughter cells have sufficient cellular material to thrive or to create specific cell types: a tiny sperm versus a gargantuan egg for example. More Botulism Current Events and Botulism News Articles |
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