Toxic specificity

For this kind of toxicity specific structural prerequisites arc not required, thus leading to some spread of the compounds in stmctural space. About five of nine layers showed little tendency to duster, some of them with quite specifically acting... 

The development of nucleic acid-based therapeutics is not as straightforward as researchers had initially anticipated. Stability, toxicity, specificity, and delivery of the compounds continue to be challenging issues that need further optimization. In recent years, researchers have come up with intricate solutions that have greatly improved the efficacy of potential antisense, ribozyme, as well as RNAi-based therapeutics. Clinical trials for all these types of nucleic acid-based therapeutics are underway. So far, data from several trials and studies in animal models look promising, in particular, the therapies that trigger the RNAi pathway. However, history has shown that compounds that do well in phase I or phase II clinical trials may still fail in phase III. A striking example is the nonspecific suppression of angiogenesis by siRNA via toII-Iike receptor 3 (Kleinman et al. 2008). It will become clear in the near future which compounds will make it as a new class of antiviral therapeutics. 

Polyester thermosets can be formulated to meet a wide range of flame, smoke, and toxicity specifications. 

Conventional refinery wastewater treatment technology is mainly concerned with removing oU, organics, and suspended solids before discharge. However, because of new stringent discharge requirements for specific toxic constituents as well as whole-effluent toxicity, specific advanced treatment processes are becoming a necessity for many refineries. This section describes the... 

Troester MA, Hoadley KA, Parker JS et al. Prediction of toxicant-specific gene expression signatures after chemotherapeutic treatment of breast eell lines. Environ Health Perspect 2004 112 1607-1613. Yang Y, Blomme EA, Waring IF. Toxicogenomics in drug discovery from preclinical studies to elin-ical trials. Chem Biol Interact 2004 150 71-85. 

Biochemical mechanisms of toxicity specific examples, in Principles of Biochemical Toxicology, 3rd ed., Timbrell, J., Ed., Taylor and Francis, London, 2000, chap. 7, pp. 259-353. 

Immunotoxicity. There are currently no in vivo studies in humans or animals that examined immunocompetence following exposure to DEHP by any route of exposure. No histopathological alterations to organs of the lymphoreticular system due to treatment with DEHP were reported by any animal study. DEHP does bind to mononuclear leukocytes in vitro (Sager and Little 1989) but this is not an inherently toxic phenomenon. The overall evidence suggests that the immune system is not a target for DEHP toxicity. Specific studies addressing this issue do not seem necessary at this time. 

Another consideration for estimating the toxicity of barium, as well as other compounds, is that the toxicity may well be altered by interactions with other toxicants. Specifically, barium would be expected to have reciprocal interactions with other trace metals found in the environment and in human tissues (Berggren et al. 1983 Foster et al. 1977 Jaklinski et al. 1967 Roza and Berman 1971 Schott and McArdle 1974). Considerations of these interactions should be made when designing future tests of barium and other compounds. 

Prediction of acute aquatic toxicity Specific toxicity... 

Plicamycin [plick a MYE sin] (mithramycin) also exerts its cytotoxicity through restriction of DNA-directed RNA synthesis. Resistance is due to P-glycoprotein efflux. Plicamycin has a relative toxic specificity for osteoclasts preventing their resorption, and lowers plasma calcium concentration in hypercalcemic patients—especially those with bone tumors. Toxicities include hemorrhage as well as effects on the bone marrow, liver, and kidneys. 

Strengths and Limitations of the Bois and Paxman Model. The Bois and Paxman model has many aspects which are desirable in a PBPK model. For instance, it specifically addressed metabolism of benzene in the bone marrow, a primary site of toxicity. Specific limitations of the model were not apparent. 

Hematological Effects. Both human and animal studies have shown that benzene exerts toxic effects on various parts of the hematological system. All the major types of blood cells are susceptible (erythrocytes, leukocytes, and platelets). In the less severe cases of toxicity, specific deficiencies occur in individual types of blood elements. A more severe effect occurs when there is hypoplasia of the bone marrow, or hypercellular marrow exhibiting ineffective hematopoiesis so that all types of blood cells are found in reduced numbers. This is known as pancytopenia. A biphasic response (i.e., a hyperplastic effect in addition to destruction of the bone marrow cells) has been observed (Aksoy et al. 1972, 1974 Doskin... 

CrylAa CrylA loop2 Receptor binding, toxicity, specificity Cadherin receptor binding, toxin activation, oligomeric and pre-pore formation, toxin insertion [74,183,184] [61,81]... 

Methyl alcohol is readily absorbed from the gastrointestinal tract, but is very slowly oxidized by the tissues. Approximately 30 percent of the absorbed alcohol remains unoxidized in the tissues 48 hours after ingestion. Roughly 40 percent of the compound is oxidized to formaldehyde and formic acid and a considerable quantity escapes in the exhaled air unchanged. Much of the formic acid formed is excreted in the urine as its sodium and ammonium salts. In addition to the depressant action of methyl alcohol upon the central nervous system, characteristic of the aliphatic alcohols, the compound elicits a definite toxic specificity for the optic nerve. 

Extensive animal research efforts during the 1950s furnished evidence that both psilocybin and psilocin are alkaloids of negligible acute toxicity. Specifically, the dosage of... 

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