Factors related to Glycophorin A mutation frequency of workers exposed to benzene / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To analyze related factors which affect GPA mutation frequency of workers exposed to benzene, with the Glycophorin A (GPA) mutation assay and explore the possibility of GPA mutation frequency as an index of predicting the risk of benzene poisoning.</p><p><b>METHODS</b>The erythrocytes were bound with fluorescent-labeled monoclonal antibody after isolated and fixed from the peripheral blood, and then the GPA mutation assay was performed using the flow cytometry (FCM). The related factors of GPA mutation frequency were analyzed by statistical methods.</p><p><b>RESULTS</b>The GPA mutation frequency of chronic benzene poisonings was significantly higher than that of their controls (P < 0.05). Significant direct correlation was found between age, length of service, accumulative exposure score and the GPA mutation frequency of workers exposed to benzene (P < 0.01). However, there was significantly inverse correlation between the 3AB index and the GPA mutation frequency (GPAN0: r(s) = -0.589, P < 0.01, GPANN: r(s) = -0.615, P < 0.01). In the multiple factor regression analysis on GPA mutation frequency, benzene exposure and individual susceptibility both entered model of multiple factors analysis, the coefficient of determination of benzene-exposed workers was 0.819.</p><p><b>CONCLUSION</b>Exposure to benzene and individual susceptibility are the most important factors that affect GPA mutation frequency. GPA mutation frequency increases with the benzene exposure and individual susceptibility.</p>

Detection of DNA injury and repair with single cell gel electrophoresis radiation in biodosimetry / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the relationship between DNA repair in vitro and in vivo after irradiation, and to describe the curves of DNA repair which can improve the accuracy of radiation dose estimation.</p><p><b>METHODS</b>The DNA double-strand break in lymphocytes of human and mouse was detected using neutral single cell gel electrophoresis (SCGE) after radiation and the curves of DNA repair individually were estimated, which were compared later.</p><p><b>RESULTS</b>Along with the time lapsing, the DNA repair of human peripheral blood and mice increased significantly and the residual damage decreased gradually, which showed significant time-effect relationship. The curve of DNA repair in vitro of human lymphocytes presented the same log model as that of mouse DNA repair in vivo. The curve showed as followed respectively: Mice: Y(TM) = 55.8256 - 10.792 lnX (R(2) = 0.629, P < 0.01) and Y(OTM) = 25.4173 - 4.5273 lnX (R(2) = 0.661, P < 0.01); Human: Y(TM) = 30.242 7 - 7.383 6 lnX (R(2) = 0.686, P < 0.01) and Y(OTM) = 17.9772 - 3.9125 lnX (R(2) = 0.752, P < 0.01).</p><p><b>CONCLUSION</b>The curve of DNA repair in vitro of human lymphocytes could be considered in biodosimetry estimation because the process of DNA repair in vitro could display the repair level and speed of DNA double-strand break in vivo.</p>

The application of single-cell gel electrophoresis to the diagnosis of fanconi anemia / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore the feasibility of single-cell gel electrophoresis (SCGE) as one of lab tests to examine DNA breakage for the diagnosis of Fanconi anemia (FA). Case Record A 4-year-and-10-month old boy presented with cryptorchism, deformities of both thumbs and esotropia of right eye. He developed thrombocytopenia and anemia when he was 3 year- and -2-month old. He was clinically diagnosed as FA.</p><p><b>METHODS AND RESULTS</b>DNA breakage of peripheral white blood cells from the patient and his parents was examined with SCGE. The percentages of cells with chromosome breakage (comet-tail positive cells) were 100%, 90% and 52% for the patient,his father and mother, respectively, while that were only 2% and 5% in two normal same-age children (P <0. 001). The micronucleus-positive lymphocytes was 6.74% in the patient, being also much higher than normal value (0.40%).</p><p><b>CONCLUSION</b>SCGE disclosed DNA breakage in the patient with FA, suggesting that it could be used as a test for determining DNA breakage of FA.</p>