a textbook of modern toxicology phần 9 pdf

... substance on a test organism as compared with the effect of a standard preparation of a basic toxicant. Although bioassay has many drawbacks, particularly lack of specificity, it can provide a rapid analysis ... very stagnant conditions are encoun- tered in the water or air. Modeling the transport of a chemical in air is particularly difficult because of the high spatial and...

Ngày tải lên: 14/08/2014, 11:21

... signaling hormones along the cascade (i.e., hypothalamic–pituitary–gonadal axis), and sometimes, a terminal target organ of the signaling pathway (i.e., hypotha- lamic–pituitary–gonadal–hepatic axis). Endocrine ... such as gamma-glutamyl transpeptidase, alkaline phosphatase, and aromatic acid decarboxylase are more preva- lent in cerebral microvessels than in nonneuronal capillaries. Most...

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... AAAAAAAA 3' AG UUU GU AG UAA AAUAA AAAAAAA AG TTT TAA AATAAGT AG Figure 2.2 Transcription, mRNA processing, and translation. DNA sense strand is designated by bold lines, hnRNA and mRNA by thinner ... codon polyadenylation signal translation termination codon TRANSCRIPTION PROCESSING TRANSLATION Amino terminusProtein mRNA hnRNA Met Phe Stop Carboxy terminus ATG GT AUG GU AUG UUU UAA A...

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... clams, and other bivalves of the cold and warm temperate areas of the Atlantic and Pacific Oceans, mainly in Japan and Europe. Only two cases of DSP have been documented in North America. Ciguatera ... associated with cardiovascular effects. Concentrations of 100 ppm can cause headaches, dizziness, nausea, and breathing difficulties. An acute concentration of 1000 ppm is invariably fa...

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... by a peroxidase that uses prostaglandin G as a substrate. In at least some of these cases, the identity of this peroxidase has been established as a prostaglandin synthase. Many of the reactions ... depots. The antimalaria drug quinacrine accumulates due to reversible intracellular binding, and the concentration in the liver can be several thousand times that of plasma. Another...

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... Examination of the term placentas of smoking human mothers revealed a marked stimulation of aryl hydrocarbon hydroxylase and related activities—remarkable in an organ that, in the uninduced state, ... desaturated fatty acids are highly susceptible to free radical attack, neighboring fatty acids are readily affected, and the initial metabolic transformation results in a cas- cade of...

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... MUTAGENICITY Mutagens are chemical and physical agents that are capable of producing a mutation. Mutagens include agents such as radiation, chemotherapeutic agents, and many car- cinogens. A mutation ... cell/hypoxanthine-guanine phosphoribosyl transferase assay, the mouse lymphoma a ssay, the mammalian trans- formation assay, sister chromatid exchange, and the chromosome aberration a...

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... 2, and 3 days. Grading is subjective and based on the appearance of the cornea, particularly as regards opacity; the iris, as regards both appearance and reaction to light; the conjunctiva, as ... exposures. IgE acts as a mediator of allergy and par- asitic immunity. IgA is found in secretions such as mucous, tears, saliva, and milk, as well as serum, and acts locally to block entrance...

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... probably unattainable with birds or wild mammals, even through bobwhite quail and mallards are easily reared in captivity. The genetics of the birds and mammals used are much more variable than are ... environmental contaminant is applied to the leaves of the terrestrial plant sorghum (Sorgum halpense), and then salt marsh caterpillars (Estigmene acrea) are placed on the plants. The larva...

Ngày tải lên: 14/08/2014, 11:21

... mating and migration habits) are considered. Finally, many extrapolation methods are limited by the availability of suitable databases. Although these databases are generally largest for chemical stressors ... human and animal use, and requires proof of both safety and efficacy. This act contains the Delaney Amendment, which states that food additives that cause cancer in humans or animals...

Ngày tải lên: 14/08/2014, 11:21