DNA repair gene XRCC3 Thr241Met polymorphism and hepatocellular carcinoma risk

The DNA repair genes have been indicated as candidates in the risk of hepatocellular carcinoma (HCC). Published data on the association between X-ray repair cross-complementing group 3 (XRCC3), a critical member of the DNA repair genes, and HCC risk were contradictory. The aim of this meta-analysis was to assess the effect of XRCC3 Thr241Met polymorphism on HCC risk by pooling available data from published case–control studies. We calculated the pooled odds ratio (OR) with the corresponding 95 % confidence interval (95 % CI) to estimate the effect. Based on the inclusion criteria, six individual studies with 2,288 cases and 3,170 controls were included into our study. Overall, significant association between the XRCC3 Thr241Met variant and HCC risk was observed under the following contrast models (OR_{Met vs. Thr}?=?1.68, 95 %CI 1.08–2.62; OR_{MetMet vs. ThrThr}?=?5.54, 95 %CI 3.09–9.94; OR_{MetMet vs. ThrThr?+?ThrMet}?=?5.70, 95 % CI 4.24–7.64). Besides, the pooled ORs indicated that the XRCC3 Thr241Met polymorphism exerted risk effect on the HCC pathogenesis among Asians. Additionally, when stratifying by the status of smoking and hepatitis B virus infection, the XRCC3 Thr241Met variant was significantly associated with HCC risk among the HBsAg (+) individuals but not the HBsAg (?) individuals, smokers, and non-smokers. The present meta-analysis suggests that the XRCC3 Thr241Met polymorphism is an independent risk factor for HCC, particularly among Asians and the HBsAg (+) individuals.     

Phenobarbital use and neurological problems in FMR1 premutation carriers

Fragile X Syndrome (FXS) is a neurodevelopmental disorder caused by a CGG expansion in the FMR1 gene located at Xq27.3. Patients with the premutation in FMR1 present specific clinical problems associated with the number of CGG repeats (55–200 CGG repeats). Premutation carriers have elevated FMR1 mRNA expression levels, which have been associated with neurotoxicity potentially causing neurodevelopmental problems or neurological problems associated with aging. However, cognitive impairments or neurological problems may also be related to increased vulnerability of premutation carriers to neurotoxicants, including phenobarbital. Here we present a study of three sisters with the premutation who were exposed differentially to phenobarbital therapy throughout their lives, allowing us to compare the neurological effects of this drug in these patients.     

Cadmium accumulation,sub-cellular distribution and chemical forms in rice seedling in the presence of sulfur

Changes in cadmium (Cd) accumulation, distribution, and chemical form in rice seedling in the joint presence of different concentrations of sulfur (S) remain almost unknown. Therefore, the indoor experiments were performed to determine the accumulation, sub-cellular distribution and chemical forms of Cd under three S levels in rice seedling for the first time. The result showed that Cd accumulation in rice roots was more than in shoots. Sub-cellular distribution of Cd in rice roots and shoots indicated that the largest proportion of Cd accumulated in cell walls and soluble fractions. As S supply increased, the proportion of Cd in cell walls reduced, while it increased in the soluble fractions. The majority of Cd existed in inorganic form, and then gradually changed to organic forms that included pectates and proteins with increased S supply. The results showed that S supply significantly influenced Cd accumulation, distribution, and chemical forms, suggesting that S might provide the material for the synthesis of sulfhydryl protein and thereby affect Cd stress on plants. These observations provided a basic understanding of potential ecotoxicological effects of joint Cd and S exposure in the environment.     

烟台15种海产品中锑含量分析

目的测定烟台市15种海产品中锑的含量,评价污染状况,探讨每人每日摄入限量。方法采用氢化物原子荧光光谱法测定烟台市15种海产品中锑的含量。结果所检测海产品中锑平均含量为6.3μg/kg,各种海产品的锑含量均低于香港公众健康与市政服务条例评价标准,且总体分布远离标准限值。单因子污染指数评价结果显示,各种海产品中锑含量均处于正常水平。蛏子中的平均含量高于其他海产品(F=118.497,P<0.05)。蛏子的每人每日允许摄入量男性、女性分别为1.81和1.61kg。结论烟台市15种海产品中均检出锑,但均未受到污染。海产品的允许摄入量较高,食用安全风险较低。     

咪唑安定对氯胺酮诱导的大鼠脑扣带回内c-fos表达的影响

目的观察咪唑安定对氯胺酮诱导大鼠扣带回c-fos基因表达的影响。方法SD大鼠20只，随机分为对照组、咪唑安定组、氯胺酮组和咪唑安定＋氯胺酮Ⅰ、Ⅱ组（MKI、Ⅱ组），每组4只。MKⅠ组、Ⅱ组分别腹腔注射眯唑安定2．5、5mg／kg，5min后，腹腔注射100mg／kg氯胺酮。对照组、氯胺酮组、眯唑安定组分别腹腔注射生理盐水、100mg／kg氯胺酮、咪唑安定5mg／kg。2h后，取脑，冰冻切片，进行Fos蛋白免疫组织化学染色。结果氯胺酮组Fos蛋白免疫组织化学阳性神经元（FLIN）明显多于对照组、咪唑安定组（P〈0．01）；MKⅠ组、Ⅱ组FLIN均少于氯胺酮组（P〈0．01），而且MKII组明显少于MKI组（P〈0．01）。结论咪唑安定可能通过剂量依赖的抑制氯胺酮诱导的c-fos在扣带回的表达，减轻或消除氯胺酮的精神副作用。