Toxicant organ

It is important to appreciate that the magnitude of the absorbed dose, the relative amounts of bio transformation product, and the distribution and elimination of metaboUtes and parent compound seen with a single exposure, may be modified by repeated exposures. For example, repeated exposure may enhance mechanisms responsible for biotransformation of the absorbed material, and thus modify the relative proportions of the metaboUtes and parent molecule, and thus the retention pattern of these materials. Clearly, this could influence the likelihood for target organ toxicity. Additionally, and particularly when there is a slow excretion rate, repeated exposures may increase the possibiUty for progressive loading of tissues and body fluids, and hence the potential for cumulative toxicity. 

Cumulative organ toxicity also presents a significant obstacle for effective chemotherapy. In many cases, the severity of the toxicity impedes the broader use of an agent. Other specific toxicities are associated with specific agents, for example cardiotoxicity with adriamycin (32), renal toxicity with i7j -platinum (28), and neurotoxicity with vincristine (49). 

For organic toxic chemicals and their degradation products the number of possibilities is very high. The environmental samples composition usually is very complicated. Unambiguous identification needs serial-pai allel strategy of analysis with many-stage crosschecking of data. 

Metabolic differences betw een humans and other animals may account for some of the interspecies differences in specific organ toxicity of trichloroethylene (see below). Among humans, sexual differences due mainly to the effects of body fat content on trichloroethylene absorption are expected based on PBPK modeling (see Section 2.3.5). 

Many chemotherapy agents have significant organ toxicities that preclude using larger and larger doses to treat the cancer. The doses of chemotherapy must be spaced out to allow the patient to recover from the toxicity of the chemotherapy each... 

With the advent of DDT it became possible to think in terms of the eradication of insect pests instead of their control only. Although very lethal organic toxicants such as the pyrethrins and rotenone had been previously employed, their instability under normal conditions of use limited their utility. 

It is not suitable for the removal of nonbiodegradable organics, toxic material, or material whose concentration is too high and thus toxic to bacteria. 

Hickey, R.F., Vanderwilen, J., and Switzenbaum, M.S., The effects of organic toxicants on methane production and hydrogen gas levels during the anaerobic digestion of the waste activated sludge, Water Res., 21, 1417-1427, 1987. 

Target Organ Toxicity. This section focuses on mechanisms for sensitive health effects of major concern for lead—cardiovascular effects, hematological effects, and neurological effects, particularly in children. Bone is a major sink for lead, and there is some limited information regarding the effects of lead on bone and potential mechanisms of action. Renal effects occur at relatively high blood lead levels and evidence of renal carcinogenicity has been demonstrated only in animals mechanisms for these effects will be discussed briefly. 

Laughlin NK University of Wisconsin, Madison, Wl Validate the efficacy of chelation agents such as succimer (dimercaptosuccinic acid, DMSA) not only to reduce body lead stores in young children but also to alleviate neurobehavioral and target organ toxicity (Rhesus monkey) National Institute of Environmental Health Sciences... 

Phospholipidosis is an excessive intracellular accumulation of phospholipids and drug, which is normally reversible after discontinuation of drug treatment. Currently, it is thought that phospholipidosis alone is not toxic per se, but because some compounds cause concurrent phospholipidosis and organ toxicity, avoidance of the issue in drug discovery projects seems prudent [74]. Fortunately, there are clear links between phospholipidosis and physical properties, especially lipophilicity, basicity, and amphiphilicity [75] which allow for good prediction of the risk. 

Burgess [538] has reviewed the charactisation and identification of organic toxicants in marine waters... 

Handy, R.D. 1993. The effect of acute exposure to dietary Cd and Cu on organ toxicant concentrations in rainbow trout, Oncorhynchus mykiss. Aquat. Toxicol. 27 1-14. 

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