Requirements for Kill

An entirely different type of contamination arises from the presence of microbiota in a product. As in the case of chemical contamination, compendial requirements for microbiological purity exists. Pharmacopoeial standards vary from country to country, and manufacturers must use the specifications and kill times that meet local requirements. As of this writing, the criteria in the British Pharmacopoeia are more stringent than those estabUshed by the CTFA, which are stricter than those in the United States Pharmacopoeia. In order to meet commonly accepted standards of microbial purity, manufacturing faciUties must be periodically cleaned and all products that can support microbial growth must contain an effective preservative (6). 

With certain Lepidoptera, the crystalline protein alone is not sufficiently toxic to cause a quick kill, and the normal course of tissue invasion by viable bacilli must take place to kill the host. Indeed, this is probably required for the bulk of susceptible Lepidoptera. However, the ability of crystal alone to produce kill (and similar singular action of another toxin produced by these bacilli on flies) places the compounds within the realm of true toxicants and mandates their consideration as chemical entities. 

The new continuous casting processes, in contrast to ingot cast products, provide tin mill products which are exceptionally clean and formable. The deoxidizing processes required for continuous casting involve either aluminum or silicon killing, which adds aluminum or silicon to the steel. Experience with type D steels indicates that the added aluminum will not cause a corrosion problem. Laubscher and Weyandt (18) have shown that the silicon found in silicon killed, continuous cast, heavily coated ETP will not adversely affect the corrosion performance of plain cans packed with mildly acid food products in which tin usually protects steel. The data on enameled cans is not definitive. Additional published data are required to determine whether or not silicon actually reduces the performance of enameled cans made from enameled, heavily coated, silicon killed, continuous cast ETP. 

Palytoxin is probably one of the most potent toxins known to humans. Intravenous LD q values in the sue species that have been studied are consistently less than 0.5 ig/kg. In addition, palytoxin possesses a speed of action and other pharmacologic properties that are markedly different from those exhibited by other toxic materials. For example, when injected iv or sc, palytoxin is extremely toxic yet when given po or ir, it is relatively non-toxic. It is also very interesting that the doses of palytoxin required to kill are somewhat different in anesthetized vs. unanesthetized animals. 

Sakaida, S., Kyle, M. and Farber, J.L. (1990). Autophagic degradation of protein generates a pool of ferric iron required for the killing of cultured hepatocytes by an oxidative stress. Mol. Pharmacol. 37, 435-442. 

Median Lethal Dose (MLD)—Dose of radiation required to kill, within a specified period (usually 30 days), 50% of the individuals in a large group of animals or organisms. Also called the LD50, or LD50/30 if for 30 days.. 

In passively immunized neonatal rats, Tyv-specific antibodies exclude larvae from the epithelium (Appleton et al., 1988), where large numbers of excluded larvae become entrapped in mucus (Carlisle et al., 1991a). Similarly, when immune adult rats are challenged with larvae, many luminal parasites are observed entrapped in mucus (Lee and Ogilvie, 1982 Bell et al, 1984). Larvae are neither injured nor killed by mucus entrapment, which is reversible and is not a requirement for expulsion (Carlisle et al., 1990). Rather, mucus appears to participate in expulsion by temporarily confining larvae to the lumen, thus facilitating their elimination from the intestine by normal physiological processes. 

LD50 Amount of liquid or solid material required to kill half of the exposed population. Values are for ingestion (Ing), percutaneous (Per) exposures, and subcutaneous injection (Sub). These values are expressed as total grams per individual. 

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