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Teratogens are substances that may cause birth defects via a toxic effect on an embryo or foetus. Wikimedia Commons has media related to Teratogens . See also the categories Carcinogens and Mutagens
Teratology is the study of abnormalities of physiological development in organisms during their life span. It is a sub-discipline in medical genetics which focuses on the classification of congenital abnormalities in dysmorphology caused by teratogens and also in pharmacology and toxicology.
Susceptibility to teratogenesis varies with the developmental stage at the time of exposure to an adverse influence. There are critical periods of susceptibility to agents and organ systems affected by these agents. Teratogenic agents act in specific ways on developing cells and tissues to initiate sequences of abnormal developmental events.
During pregnancy, a woman can also be exposed to teratogens from contaminated clothing or toxins within the seminal fluid of a partner. [38] [30] [39] An additional study found that of 200 individuals referred for genetic counseling for a teratogenic exposure, 52% were exposed to more than one potential teratogen. [40]
Given that retinoic acid (RA) regulates numerous embryonic and differentiation processes, one of the proposed mechanisms for the teratogenic effects of ethanol is a competition for the enzymes required for the biosynthesis of RA from vitamin A. Animal research demonstrates that in the embryo, the competition takes place between acetaldehyde and ...
Maitotoxin has been shown to be more than one hundred thousand times as potent as VX nerve agent. [1] Maitotoxin is so potent that it has been demonstrated that an intraperitoneal injection of 130 ng /kg was lethal in mice. [ 2 ]
They are a class of sympathomimetic agents, each acting upon the beta adrenoceptors. [2] In general, pure beta-adrenergic agonists have the opposite function of beta blockers : beta-adrenoreceptor agonist ligands mimic the actions of both epinephrine - and norepinephrine - signaling, in the heart and lungs, and in smooth muscle tissue ...
Genotoxicity is the property of chemical agents that damage the genetic information within a cell causing mutations, which may lead to cancer. While genotoxicity is often confused with mutagenicity, all mutagens are genotoxic, but some genotoxic substances are not mutagenic. The alteration can have direct or indirect effects on the DNA: the ...