Toxicity symptoms

Nickel carbonyl is volatile, has Htde odor, and is extremely toxic. Symptoms of dangerous exposure may not appear for several days. Effective medical treatment should be started immediately. The plant should be designed to ensure containment of nickel carbonyl and to prevent operator contact. 

Infants maybe sensitive to doses of vitamin A [11103-57-4] in the range of 75,000—200,000 lU (22.5—60 mg), although the toxic dose in adults is probably 2—5 million lU (90.6—1.5 g). Intakes in this range from normal food suppHes without oral supplements are simply beyond imagination (79). Vitamin D [1406-16-2] toxicity is much more difficult to substantiate clinically. Humans can synthesize active forms of the vitamin in the skin upon irradiation of 7-dehydrocholesterol. Toxic symptoms are relatively nonspecific, and dangerous doses seem to He in the range of 1000—3000 lU/kg body wt (25—75 flg/kg body wt) (80). Cases of toxicity of both vitamins E and K have been reported, but under ordinary circumstances these vitamins are considered relatively innocuous (81). 

Oral appHcations of 1500 mg/kg/d for two weeks caused death of rats. Repeated oral appHcations (4 wks) of 30 p-L/kg to rats caused no toxic symptoms, 100 pL/kg resulted in minor toxic effects, and 300 pL/kg induced impairment of several organs andlethaHty. Repeated oral appHcations (26 x) of 0.1 mL/kg caused no toxic symptoms in cats or rabbits. Inhalation of 1500 ppm (2 wks) were without effects, whereas in a similar study with... 

Phase II. Initial clinical studies for therapeutic safety and efficacy are performed in volunteer patients who are suffering from the disease for which the dmg has therapeutic promise. Recognition of toxic symptoms and side effects are vital at this point because these may occur here, even when not observed in animal studies or in Phase I. 

The toxic symptoms from inhalation of nickel carbonyl are beUeved to be caused by both nickel metal and carbon monoxide. In many acute cases the symptoms ate headache, di22iQess, nausea, vomiting, fever, and difficulty in breathing. If exposure is continued, unconsciousness follows with subsequent damage to vital organs and death. Iron pentacarbonyl produces symptoms similar to nickel carbonyl but is considered less toxic than nickel carbonyl. 

Feeding experiments with horses seemed to indicate that the alkaloid caused toxic symptoms and loss of hair when large doses were administered. 

The second type of material includes spores, which may or may not produce disease symptoms but which can germinate in the insect gut and give rise to vegetative bacterial cells which in turn may produce, and exoenzymes such as phospholipases (lecithinases) or hyaluronidase. The phospholipases may produce direct toxic symptoms owing to their action on nervous or other phospholipid-containing tissue. Hyaluronidase breaks down hyaluronic acid and produces effects on animal tissue which are morphologically similar to the breakdown of insect gut wall in the presence of microbial insecticide preparations. 

As the drag circulates in the blood, a certain blood level must be maintained for the dragp to be effective When the blood level decreases below the therapeutic level, the drag will not produce the desired effect. Should the blood level increase significantly over the therapeutic level, toxic symptoms develop. Specific therapeutic blood levels are discussed in the subsequent chapters when applicable. 

Most of the organic pollutants described in the present text act at relatively low concentrations because they, or their active metabolites, have high affinity for their sites of action. If there is interaction with more than a critical proportion of active sites, disturbances will be caused to cellular processes, which will eventually be manifest as overt toxic symptoms in the animal or plant. Differences between species or strains in the affinity of a toxic molecule for the site of action are a common reason for selective toxicity. 

Selenium is required, but levels must fall into a narrow window. Both deficiency and toxicity symptoms occur. The element is also used therapeutically in cancer treatment. It is the co-factor of the enzyme glutathione peroxidase which is thought to play an important role in oxygen toxicity. The determination of Se in blood or serum is not easy, as many incorrect, inaccurate and imprecise methods have been published (Magee and James 1994). A suggested procedure for Se in body fluids is based on GF-AAS (Thomassen et al. 1994)- For tissues SS-AAS may be used (Fler-ber 1994a). Recent developments by Turner et al. (1999) show that LC-ICP-MS is sensitive and reproducible at low levels. 

Rubin et al. (14) have shown that 1250 p.p.m. of DDT in the diet of laying hens for 12 weeks produced toxic symptoms and death. In the work reported here the highest level of DDT used was 200 p.p.m. The authors did not observe toxic symptoms at this or lower levels. 

In humans, acute exposure to acrylonitrile results in characteristics of cyanide-type toxicity. Symptoms in humans associated with acrylonitrile poisoning include limb weakness, labored and irregular breathing, dizziness and impaired judgment, cyanosis, nausea, collapse, and convulsions (Baxter 1979). However, the doses that produce these effects were not clearly defined. Workers exposed to 16 to 100 ppm for 20 to 45 minutes complained of headaches and nausea, apprehension and nervous irritation (Wilson et al. 1948). The workers exposed to acrylonitrile vapors fully recovered. In a study with human volunteers exposed to acrylonitrile at doses of 2.3 and 4.6 ppm, no symptoms attributable to effects on the nervous system were observed (Jakubowski et al. 1987). 

Lithium toxicity can occur with serum levels greater than 1.5 mEq/L, but the elderly may have toxic symptoms at therapeutic levels. Severe toxic symptoms may occur with serum concentrations above 2 mEq/L, including vomiting, diarrhea, incontinence, incoordination, impaired cognition, arrhythmias, and seizures. Permanent neurologic impairment and kidney damage may occur as a result of toxicity. 

Akathisia, akinesia, and dysphoria can result in behavioral toxicity. Symptoms may include apathy and withdrawal, and patients may appear... 

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