The effects of microcystin-LR on the mRNA expression levels of base excision repair genes and genes related to apoptosis / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the effects of microcystin-LR (MCLR) on the expression of base excision repair genes and genes related to apoptosis.</p><p><b>METHODS</b>The BRL-3A cells were exposed to different concentrations of MCLR for various periods of time and the cell viability was measured by MTT. The mRNA expression was determined with the quantitative real-time polymerase chain reaction (QRT-PCR).</p><p><b>RESULTS</b>The viability of BRL-3A cells significantly reduced in a concentration- and time-dependent manner. In 30 µg/ml group, the mRNA expression level (1.327 ± 0.028) of p53 increased significantly at 24 h after exposure, as compared with the other groups (1.005 ± 0.117, 0.862 ± 0.154, 1.028 ± 0.056 and 1.015 ± 0.091) (P < 0.05). The mRNA expression levels (5.080 ± 0.729, 5.820 ± 0.373, 6.018 ± 0.359 and 6.183 ± 0.515) of Bax in all exposure groups were significantly higher than that (1.024 ± 0.277) in control group at 24 h after exposure. However, the Bax mRNA expression level (0.604 ± 0.146) in the 30 µg/ml group at 72 h after exposure was significantly lower than those (1.004 ± 0.107, 0.811 ± 0.142, 0.855 ± 0.101 and 0.814 ± 0.056) in other groups (P < 0.05). When compared with control group (1.006 ± 0.132) and 1 µg/ml group (1.034 ± 0.241), the mRNA expression level (0.488 ± 0.147) of PARP1 in 30 µg/ml group at 48 h after exposure decreased significantly (P < 0.05). Furthermore, the mRNA expression levels (0.594 ± 0.180, 0.491 ± 0.015 and 0.305 ± 0.091) of JWA, XRCC1 and PARP1 in 30 µg/ml group at 72 h after exposure decreased significantly, as compared with the other groups (P < 0.05).</p><p><b>CONCLUSION</b>The induction of gene expression is a transient phenomenon that occurred at different times of exposure for different genes. Inhibition of MCLR on the base excision repair gene expression may play important role in the course of MCLR promoting liver tumor.</p>

A hospital-based case-control study on influencing factors of nonalcoholic fatty liver disease / 中华肝脏病杂志

<p><b>OBJECTIVES</b>To investigate the influencing factors of nonalcoholic fatty liver disease (NAFLD).</p><p><b>METHODS</b>A hospital-based case-control study was conducted in patients with NAFLD and controls without NAFLD in a hospital from January to August in 2007. All data were analyzed by SPSS 13.0 software.</p><p><b>RESULTS</b>One-way analysis of variance found that the two groups were significantly different in cigarette smoking, alcohol and tea comsumption, movement index, speed of food intake, frequency of social engagement, kinds of edible oil, marine products, family history of NAFLD, hypertension, higher blood sugar, abnormality of blood fat, higher level of ALT, higher level of AST, hyperuricemia, obesity, decrease of high density lipoprotein (HDL), and increase of low density lipoprotein. By non-conditional logistic stepwise regression analysis, 12 of 18 factors were used to construct a model, ten of which were the risk factors and two were protective factors of NAFLD. Risk factors included obesity (OR=6.35), hypertension(OR=3.82), dyslipidemia (OR=2.95), decrease of HDL (OR=2.85), hyperglycemia (OR=2.82), increase of ALT (OR=2.80), hyperuricemia (OR=2.35), HBsAg positive (OR=1.99), family history of fatty liver (OR=1.79) and frequently intake of marine products (OR=1.58), and protective factors included tea drinking (OR=0.72) and exercise (OR=0.90).</p><p><b>CONCLUSIONS</b>There are many influencing factors of NAFLD, and life styles are the key factors. Genetic background may also play some roles in NAFLD.</p>