Toxicity from stimulants

Ipecac is prepared from the dried roots and rhizomes of Cephaelis ipecacuanha (Brot.) A. Rich, and contains the alkaloids emetine [483-18-1] (17) and cephaeJine [483-17-0] (18) in a ratio between 2 1 and 4 1. It has been used extensively in cough preparations and is beheved to act by gastric reflex stimulation. Toxic effects include vomiting, irritation of the gastrointestinal tract, and cardiac arrhythmias (19). Ipecac symp is available over-the-counter in the United States only in 30-mL containers for use as an emetic in treating poisonings. 

The immunotoxicology of metals in fishes has been reviewed elsewhere [74-76, 45], Overall, the immune systems of fishes are highly sensitive to metals, although the effects are not always suppression of immune functions. Burnett [76] demonstrated that low levels of metals increased intracellular calcium, increased protein phosphorylation, and stimulated lymphocyte proliferation in fish. Since most metals are toxic to both the nervous system and the immune system, a neuroendocrine-immune link to immuno-toxicity from metal exposure is likely. 

Infiltration (i.e., the injection of local anesthetics under the skin) of the surgical site provides adequate anesthesia if contiguous structures are not stimulated. Since the onset of local anesthesia is rapid, the surgical procedures can proceed with little delay. Minimally effective concentrations should be used, especially in extensive procedures, to avoid toxicity from overdosage. 

Glycidol is an eye, lung, and skin irritant. The pure compound caused severe but reversible corneal injury in rabbit eyes (ACGIH 1986). Exposure to its vapor caused irritation of lung in mice, resulting in pneumonitis. There is no evidence of any cumulative toxicity. From the limited toxicity data, it appears that the health hazard to humans from its exposure is, primarily, respiratory irritation, stimulation of the central nervous system, and depression. 

Electrodes are the direct interface between the biological structures (auditory neurons) and the electronic system in the CFs. Stimulation electrodes inject charge into the tissue to functionally excite the nerves by electrical stimulation. In other words, electrodes measure the electric potential for charge transfer between solid metal state and electrolyte solution in liquid state inside the cochlea. For better stability implants electrode properties must be evaluated with respect to a biocompatible application for optimum stability, efficacy and life time with a minimum of toxicity. From the material point of view the requirements of an ideal electrode [8-10] might be summarized as follows ... 

The toxic effects of synthetic polymers include inhibition of hepatic microsomal oxidase enzymes, stimulation of liver transaminases, hepatosplenomegaly, thymic involution, anaemia, and decrease in bone marrow cells Fortunately, many neutral synthetic polymers do not show toxic effects. For those polymers which exhibit toxic effects, e.g. polyanions, it is sometimes possible to separate the toxicity from antitumour, antiviral and immunological effects In general the toxicity of polyanions increases with molecular weight (particularly for M > 50,000). 

Extraction procedure (EP toxicity is determined (in the United States) fi om a laboratory procedure that stimulates leaching from a disposal site under actual disposal conditions. Regulations compare the results from this test with the national interim Primary Drinking Water Standards. (PDWS) (see Table 4-5) to determine whether a waste is hazardous. A waste is hazardous if it produces an EP toxicity value that is 100 times the PDWS under specified laboratory testing conditions. 

In the case of T-2 toxin the toxicity increased with the temperature from 10 to 15°Cand then decreased to show a stimulation of the light emission at 25° C. This effect was found to be independent of the exposure time. HT-2 toxin and DAS, however, showed the opposite pattern with decreasing toxicity from 10 to 15°C and increasing toxicity at higher temperature. For DON, the toxicity i ncreased with temperature at all exposure times. An overview of the observed toxicity temperature dependencies is given in FIGURE 4. 

Reactions at the aromatic nucleus that are quite different from the usual mild condensations and rearrangements which apparendy generate the typical alkaloids already discussed must be iavolved. Securinine (137) is reported to stimulate respiration and increase cardiac output, as do many other alkaloids, but it also appears generally to be less toxic (98). 

Barium metal and most barium compounds are highly poisonous. A notable exception is barium sulfate which is nontoxic because of its extreme iasolubihty ia water. Barium ion acts as a muscle stimulant and can cause death through ventricular fibrillation of the heart. Therefore, care must be taken to avoid contact with open areas of the skin. Workers must wear respirators (of type approved for toxic airborne particles), goggles, gloves, and protective clothing at all times. The toxic barium aluminate residue obtained from barium production is detoxified by reaction with a solution of ferrous sulfate and converted iato nontoxic barium sulfate. According to OSHA standards, the TWA value for Ba and Ba compounds ia air is 0.5 mg/m. ... 

Soluble Compounds. The mechanism of barium toxicity is related to its ability to substitute for calcium in muscle contraction. Toxicity results from stimulation of smooth muscles of the gastrointestinal tract, the cardiac muscle, and the voluntary muscles, resulting in paralysis (47). Skeletal, arterial, intestinal, and bronchial muscle all seem to be affected by barium. 

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