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Serum bile acids (SBAs) are suggested as a potentially sensitive and specific indicator of liver function which, accordingly, could provide an early indication of hepatobiliary dysfunction. This offers advantages over more traditional parameters of liver integrity/function. Recent studies have shown that occupational exposure to low levels of halogenated aliphatic or non-halogenated aromatic solvents is associated with significant increases in SBA levels. As this has often been evident in the absence of any effect on conventional parameters of hepatobiliary integrity/function, elevated SBA levels may well be regarded as a sensitive biological marker of exposure/effect of these compounds. In addition, it may be considered that they provide an early indicator of solvent-induced changes in hepatobiliary function. Extensive studies with experimental animals have also provided supporting evidence for these observations in solvent-exposed individuals. Investigations of the mechanisms at cellular and subcellular levels by which these increases occur have suggested that these effects are likely to be the result of selective, dose-related and reversible inhibition of bile acid uptake at the sinusoidal domain of the hepatocyte plasma membrane. Increased concentrations of SBA under low levels of exposure to different solvents have been demonstrated to be a short-lived and reversible effect which is not accompanied by any other evidence of liver damage. Therefore, it could be assumed that it is unlikely that there would be pathological sequelae to these effects, although the longer term ramifications of such effects have not been thoroughly investigated. Nevertheless, the available evidence indicates that investigation of SBA in solvent-exposed workers could provide useful indications of exposure and effect. [ABSTRACT FROM AUTHOR]

DNA adducts resulting from carcinogenic chemicals are becoming more frequently used as a powerful biomarker to determine the extent of exposure. The available techniques for determination of bulky DNA adducts can be classified into four m ajor groups, these being immunological assay, fluorescence techniques, chromatography/m ass spectrom etry and the 32P-postlabelling technique. In this review, the features of current techniques and the combined applications are summarized and compared. Among the available techniques, the 32P-postlabelling assay seems to best meet the application criteria overall. In particular, 32P-postlabelling is the most suitable technique for the detection of bulky DNA adducts induced by unknown environmental and occupational chemicals or m ixtures. [ABSTRACT FROM AUTHOR]