Repeats in toxin

RTX Repeat in toxins pore-forming toxin of E. coli type (RTX toxin) also... 

Ll, L., Rock, J.L. Nelson, D.R. Identification and charactenzation of a repeat-in-toxin gene cluster in Vibrio ar uillarum. Infect. Inmun. 76, 2620-2632 (2008). 

However, when this experiment was repeated in the presence of GDP/JS in addition to the GTP7S, membranes were obtained which could be ADP-ribosylated and yet had essentially no cyclase activity. With respect to cholera toxin they behaved as if they were responding to the GTPyS and yet their Ns site was clearly occupied by GDP0S. There had to be a second site for ADP-ribosylation. We called this second site S [8]. Presumably when membranes are soaked in GDP S and GTP7S the two sites select different nucleotides ... 

By employing C14-labeled pyrethrum, it has been determined that at 35 °C. the rate of penetration of pyrethrum is more than twice that at 15°C. Cockroaches prostrate at 15 °C. can be returned to normal by transferring them to 35 °C., a process which can be repeated for several hours. Since cockroaches transferred from 35° to 15°C. became prostrate more rapidly than those held continuously at 15°C., the insecticide (or some metabolic toxin) was probably in the vicinity of its site of action at 35 °C. but was ineffective. 

There are reports of the benefits of botulinum toxin in the treatment of cerebral palsy in children. The toxin, produced by Clostridium botulinum, is a powerful and deadly poison, but is also an effective muscle relaxant. It is not licensed for use as such in the UK but is undergoing clinical trials. Current evidence suggests that repeat injections are necessary some 4-6 months after the first. 

Another major change was the shift from extensive use of field laboratory exploration techniques to the laboratory techniques hke ICP-AES and INAA. These produce a higher quality data than had resulted from the dc arc and other field techniques, with respect to both repeatability of measurement and improved detection limits. The metrology laboratory certifications for As and Hg in soils and sediments as key environmental toxins provided strong support to mineral exploration programs. 

In most instances, C. difficile toxin testing of a single stool specimen effectively establishes the diagnosis. Various ELISA kits are available to detect toxin A or toxin B or both. Those that detect both toxin A and B are preferred. Repeated testing can boost sensitivity. 

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