Toxicity thallium

MulkeyJP and Oehme FW A review of thallium toxicity. Vet Hum Toxicol 35 445-453, 1993... 

Cs) and urinary thallium concentrations can guide the recommended duration of therapy. Adjunctive supportive care for possible acute radiation illness (137Cs) or systemic thallium toxicity should be instituted as needed. 

Unlike exposure to most metal salts, gastrointestinal symptoms of thallium toxicity are relatively minor, and constipation is more characteristic than diarrhea. The major manifestations of toxicity consist of a rapidly progressive, ascending, extremely painful sensory neuropathy and alopecia. Other potential symptoms of overexposure are nausea, diarrhea, abdominal pain, and vomiting seizure, tremor and psychosis. Thallium is one of the most toxic of all metals. It is a cumulative poison with an estimated lethal dose of 8-20 mg kg in humans. It is difficult to predict the out come of thallium poisoning. With high exposure, death results very soon. 

Hoffman RS (2003) Thallium toxicity and the role of Prussian blue in therapy. Toxicology Review IT. 29-40. 

The mechanism of thallium toxicity at the molecular level in animals and humans seems to be analogous to the enzyme-inhibiting effects of lead and mercury, and an oxidative stress, resulting in a general histotox-icity (Table 22.2) (Repetto et al. 1998, Leung and Ooi 2000, Appenroth and Winnefeld... 

Tab. 22.2 Mechanisms of thallium toxicity. (Adapted from Repetto etal. 1998.)...

In animal experiments with chronic ingestion of small amounts of thallium, damage and changes in the mitochondrial system of nervous cells have also been observed. Humans exposed chronically to small amounts of thallium revealed not the typical symptoms of thallium toxicity, the most consistent findings being polyneuropathy and psychiatric changes (Kazantzis 1986). 

Appeneoth D and Winneeeld K (1999) Reconsideration of some hypotheses on the mechanism of thallium toxicity in rats with special respect to ribo-fiavin and glutathione. Nephrol Dial Transplant 14 (Suppl 4) 16-18. 

Leung KM and Ooi VEC (2000) Studies on thallium toxicity, its tissue distribution and histopathological effects in rats. Chemosphere 41 155 — 159. 

I. Mechanism of toxicity. The mechanism of thallium toxicity is not known. It appears to affect a variety of enzyme systems, resulting in generalized cellular poisoning. Thallium metabolism has some similarities to that of potassium, and it may inhibit potassium flux across biological membranes by binding to Na-K ATP transport enzymes. 

Detailed accounts of the clinical progression of thallium toxicity have been published [20-26]. With acute exposure one of the main symptoms is constipation without response to laxatives, presumably due to iliad paralysis. A neuropathic pain develops in the lower extremities and soles of the feet. Extreme abdominal and retrosternal pains develop, along with sleeplessness and excessive thirst. Other symptoms and findings include paresthesia in the extremities, ptosis, fever, conjunctivitis, anhydrosis, and stomatitis. 

The Tl derivatives are excellent electrophiles that are used in organic synthesis for reactions with olefins and aromatics. In particular, the trifluoroacetate T1 (TFA)3 allows to carry out highly regioselective aromatic electrophilic substitution reactions in trifluoroacetic acid (see Chap. 17.3.2). It is probable that thallium toxicity will limit this use in the future. 

Cvjetko, R, Cvjetko, I., Pavlica, M., 2010. Thallium toxicity in humans. Arh. Hig. Rada. Tolsikol 61,111-119. 

Riyaz, R., Pandalai, S.L., Schwartz, M., et al, 2013. A fatal case of thallium toxicity challenges in management. J. Med. Toxicol. 9, 75-78. Rodrlguez-Mercado, J.J., Altamirano-Lozano, M.A., 2013. Genetic toxicology of thallium a review. Drug Chem. Toxicol. 36, 369-383. 

Galvan-Arzate S, Santamaria A. Thallium toxicity. Toxicol. Lett. 1998 99 1-13. 

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