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To study the effect of low-dose (rate) radiation on human health, we analyzed chromosomes of peripheral lymphocytes of residents in a high background radiation area (HBRA) and compared the results with those obtained from residents in a control area (CA) in Guangdong Province, China. Unstable types of chromosome aberrations (dicentrics and rings) were studied in 22 members of eight families in HBRA and 17 members of five families in CA. Each family consists of three generations. On average 2,600 cells per subject were analyzed. 27 adults and six children in HBRA and 25 adults and eight children in CA were studied with respect to translocations. On average 4,741 cells per subject were examined. We found an increase of the frequency of dicentrics and rings in HBRA, where the natural radiation level is three to five times higher than in the control area. But the increase of translocations in HBRA was within the range of individual variation in the controls.

A simple, rapid and accurate liquid chromatography - tandem mass spectrometry method was developed and validated for the quantification of acetazolamide in beagle plasma using sulfadiazine as the internal standard. After extraction by acetonitrile, the analytes were separated by a rapid gradient elution with acetonitrile and water as the mobile phase on a SHIMADZU VP-ODS C18 column and then detected by an API 4000 triple-quadrupole mass spectrometer using electrospray ionization in negative ion mode. Multiple reaction monitoring was performed on the ion transitions of m/z 220.9→83.3 (acetazolamide) and m/z 248.9→185.0 (sulfadiazine). The plasma concentration of acetazolamide in beagle dogs showed good linearity over the range of 0.20~50 μg/mL, and the intra- and inter-day variations were small with high accuracy and absolute recovery. Both analytes can maintain stable during the whole experimental process. The developed method was successfully applied to the pharmacokinetic study of acetazolamide extended-release capsules after oral administration to beagle dogs.

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