Nine cases of accidental exposure to dimethyl sulphate--a potential chemical weapon

Dimethyl sulphate (DMS) is an innocuous appearing, widely used, and highly toxic chemical. It is used both as a methylating agent in industrial chemical synthesis and in medical laboratories for chemical cleavage of DNA. It is readily absorbed through the skin, mucous membranes, and gastrointestinal tract. Delayed toxicity allows potentially fatal exposures to occur prior to development of any warning symptoms. Toxicity is manifested initially by mucosal inflammation of eyes, nose, oropharynx, and airways. This can progress to severe airway oedema and necrosis, and non-cardiogenic pulmonary oedema. Other systemic effects include convulsions, delirium, coma, and renal, hepatic, and cardiac failure. All these features make DMS a potential chemical weapon. We report nine cases of varying degrees of inhalational exposure to DMS, occurring as a result of a single chemical spillage incident in the United Kingdom. Industrial poisoning is surprisingly rare and there are few previous reports in the literature outside China.

Biological fate of sulphur mustard: identification of valine and histidine adducts in haemoglobin from casualties of sulphur mustard poisoning

1. Analytical methods were developed for the detection of N-terminal valine and histidine adducts in haemoglobin alkylated with sulphur mustard. 2. N-(2-hydroxyethylthioethyl)-N-terminal valine was selectively cleaved from globin with the Edman reagent pentafluorophenyl isothiocyanate. The resulting thiohydantoin derivative was analysed by high resolution gc-ms using negative ion chemical ionization. An alternative procedure, involving acid hydrolysis of globin to its constituent amino acids and conversion of the adduct to its di-TBDMS derivative, was less sensitive. 3. N-(2-hydroxyethylthioethyl)histidine was analysed, after acid hydrolysis of globin, as its fluorenylmethyloxycarbonyl derivative by lc-ms-ms using electrospray ionisation and selected reaction monitoring. 4. N-(2-hydroxyethylthioethyl)valine and (2-hydroxyethylthioethyl)histidine were detected in globin isolated from a rat treated percutaneously with sulphur mustard, and in globin from five blood samples collected from human casualties of sulphur mustard poisoning. The adducts are proposed as biological markers of sulphur mustard poisoning. in addition to urinary metabolites and DNA adducts.

N-alkylvaline levels in globin as a new type of biomarker in risk assessment of alkylating agents

Adducts with the N-terminal valine of erythrocyte globin can serve as individual biomarkers of systemic and cellular exposure to endogenous and exogenous alkylating agents. In contrast to "detoxification markers" of this kind of mecapturic acids derived from alkylation of glutathione, individual N-alkylations of valine in globin reflect the formally "toxifying" part of the stress due to alkylating agents transformed into the ultimate toxicant. Thus, in contrast to the traditional methods of biological monitoring this approach enables a better evaluation of systemic exposure to reactive agents, adapted more sensibly to the exposure situation over the whole life span of erythrocytes, and it can serve as a specific biomarker of exposure for the purpose of health surveillance in occupational medicine. An individual evaluation of exposures in comparison with the range of corresponding background levels is discussed from the point of view of supplementary risk assessment in medical surveillance of occupationally exposed persons.

[Complete change of the cell composition of the liver parenchyma following exposure to dipin and partial resection]

The phenomenon of total replacement of preexisting and damaged hepatocytes in mice were demonstrated by the method of autoradiography. Adult mice were injected an alkylating drug Dipin 2 h prior to partial hepatectomy and then proliferating cells were labelled by means of multiple injections of 14C-thymidine. Dipin in combination with mitotic stimulation induced multiple mitotic aberrations in proliferating hepatocytes resulting in degeneration, death and then elimination of prelabelled liver cells. New parenchymal tissue originated from non-labelled preneoplastic nodules. These hepatocyte nodules grew in size, propagated and 8-10 months later completely replaced the preexisting hepatocytes.