Toxicants that disturb the

Toxicants that disturb the action of hormones involved in reproduction and development are of particular ecotoxicological significance. Endocrine disrupters may bind to hormone receptor sites, thus interfering with the essential functions of the endocrine system. Endocrine disrupters may... 

Toxicants that disturb the electrolytic or osmotic balance or the pH... 

Clinical studies with streptovaricins have been Umited. The most significant toxicity reported in the clinical studies has been gastrointestinal disturbances. However, indications are that the toxicity does not result from the individual streptovaricins but from some impurity in some fermentation lots (85). 

Finally, it should be noted that although the arbitrary activity of 10 g ion/1 represents a very low concentration of metal ions it could be significant in certain circumstances, e.g. lead at that concentration would render potable water toxic. It should also be noted that if the equilibrium is continuously disturbed, e.g. by a flowing solution, significant amounts of metal will corrode even at an equilibrium activity of 10 g ion/1. 

Host cells are killed by cytotoxic T-ceUs or natural kiUer cells by the processes of necrosis or apoptosis. Necrosis leads to release of cell contents that can sufficiently disturb the tissue to initiate a local inflammatory response. However, the cell killed by apoptosis is then phagocytosed, which does not cause local disturbance, so that inflammation does not occur (Chapter 20). Apoptosis is achieved by two mechanisms release of toxic granules by the cytotoxic cells or by the binding of the cytotoxic ceU to the host ceU, via its death receptor protein (see below). 

Toxic material was placed many years ago in the sediments of a lake. Sedimentation since that time has continued their burial. Now, a harbor authority would like to put in ship piers with pilings that may disturb the toxic compounds in the sediments. You would like to know if the concentrations of the toxic compound have reached a sufficient level that the pilings will create an environmental threat. Which equation would you use for a quick, first estimate (See Figure E2.3.1.)... 

After a week s therapy, if a small quantity of alcohol is consumed by the patient, it produced unpleasant toxic reactions such as flushing, palpitation, nausea, vomiting throbbing headache, uneasiness, dizziness, visual disturbances, fall in blood pressure and even collapse. The patient thus realizes that during the treatment he can not tolerate even a small amount of alcohol and would abstain from alcohol drinking. 

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