Human papillomavirus in high- and low-risk areas of oesophageal squamous cell carcinoma in China

To examine the potential roles of human papillomavirus (HPV) in oesophageal squamous cell carcinoma (ESCC) development, we examined the presence of HPV DNA in paraffin-embedded ESCC tissues collected from two areas with different ESCC incidence rates in China, that is, Gansu (n=26) and Shandong (n=33), using PCR with SPF10 primers, or PCR with GP5+/GP6+ primers combined with Southern blot hybridisation. HPV genotype was determined by the INNO-LiPA HPV genotyping kit. HPV DNA was detected in 17 cases (65%) in Gansu, where ESCC incidence is much higher than in Shandong, where HPV was positive in two samples (6%). HPV genotypes 16 and 18 were detected in 79 and 16% of HPV-positive samples, respectively. Real-time PCR analysis suggested the presence of integrated form of HPV DNA in all the HPV-16-positive samples, but its viral load was estimated to be only <1-2 copies cell(-1). We could not detect HPV 16/18 E6 protein expression by immunostaining in any of the HPV-16-positive samples. Neither p16(INK4a) nor p53 expression was related to HPV presence in ESCCs. Further studies seem warranted to examine the possible aetiological roles of HPV in ESCC.     

Abnormality of synaptic vesicular associated proteins in cerebral cortex and hippocampus after microwave exposure

Studies were performed to determine the effects of microwave on synaptic vesicles and the expression of synaptic vesicular associated proteins including synapsin I, VAMP‐2, syntaxin, and synaptophysin. 25 Wistar rats were exposed to microwave which the average power density was 30 mW/cm², and whole body average specific absorption rate was 14.1 W/kg for 5 min. Synaptosome preparations in the cerebral cortex and hippocampus were obtained by isotonic Percoll/sucrose discontinuous gradients at 6 h, 1, 3, and 7 days after radiation. The expression of synaptic vesicular associated proteins was measured using Western blots and image analysis. The interaction between VAMP‐2 and syntaxin was examined by coimmunoprecipitation analysis. Synapsin I in the cerebral cortex were decreased at 3 days (P < 0.01) after radiation and in the hippocampus increased at 1 day (P < 0.01), decreased at 3 days (P < 0.01), increased again at 7 days (P < 0.01) after exposure, compared with the sham‐treated controls. Synaptophysin were increased in 1–7 days (P < 0.01) after exposure in the cerebral cortex and hippocampus. VAMP‐2 were decreased at 1 and 3 days (P < 0.01) and syntaxin were decreased in 6 h to 3 days (P < 0.01) after radiation in the cerebral cortex and hippocampus. The interactions between VAMP‐2 and syntaxin were decreased at 3–7 days (P < 0.01) after radiation in the cerebral cortex and hippocampus, compared with the sham‐treated controls. These results suggest that 30 mW/cm² (SAR 14.1 W/kg) microwave radiation can result in the perturbation of the synaptic vesicles associated proteins: synapsin I, synaptophysin, VAMP‐2, and syntaxin. The perturbation could induce the deposit of synaptic vesicle, which might be relative to the dysfunction of the synaptic transmission, even the cognition deficit. Synapse 63:1010–1016, 2009. © 2009 Wiley‐Liss, Inc.     

The establishment of a portable high sensitivity exhaled thoron activity measurement system.

A portable system, using electrostatic collection, for the measurement of exhaled thoron activity in humans is described, together with details of the basic theory, equipment, calibration procedures, measurement and preliminary use. The portable system built on experience at the Argonne National Laboratory (ANL) to achieve a reduction in measurement time from 30 h to 200 min, and to increase the total efficiency of the system from 50% (at ANL) to 70%. The limit of detection of the system (2sigma above zero) is 0.007 Bq of thoron activity outside the body. The total standard error of this system is 47% for a thorium lung burden of 0.22 Bq. The average background of this scintillation detector was 0.003 counts min(-1).     

高天然放射性本底地区是研究小剂量电离辐射人群健康影响的重要场所

目的 在高天然放射性本底地区(HBRA)进行小剂量电离辐射对人群健康影响的研究需要分析这类研究的有利条件、薄弱环节和目前存在的问题,从而能获得有效的资料,并能有针对性地进行深入研究。方法 作者选择中国的高本底辐射研究组在广东省阳江[阳东县、阳西县]内的HBRA和相邻的对照地区(恩平县内)所获得的流行病学资料作为一项实例进行分析。高本底辐射研究组从1972年起采用动态人口和定群人口观察染色体畸变率、突变性疾病发生率和癌症死亡率以及相关的剂量学和混淆因素的研究。从1991年开始,研究组与日本体质研究会进行合作研究。结果 对环境的和宿主的诱突因素进行分类研究证明它们在高本底和对照地区是可比的；染色体畸变率在一定剂量以上时随剂量增加而增加；但HBRA遗传性疾病和先天性畸形总患病率不高于对照。HBRA的癌症死亡率与对照相比,相对危险(总的死亡率和按部位分的癌死亡率)小于1或接近1.作者引用了该研究组两种理论分析(修改的微剂量学理论和“有利与有害作用”竞争的假说).结论 在小剂量低剂量率长期作用下,照射剂量与群体的突变性疾病发生率或癌症死亡率不呈现“线性、无阈”的关系。在小剂量电离辐射作用下,人体出现有利的因素(如免疫能力增强)和不利的因素(如染色体畸变频率增加〕,结合与人体的防御、修复功能柑结合,有利困素很可能占主导地位,这类研究已经并继续取得有用的资料。     

典型居室内氡子体的特性

用瞬时和连续两种方法对澳大利亚一所典型住房室内氡子体的特性进行了初步调查, 两种方法的结果符合得很好。氡予体平衡因子在0.17至0.49之问, 瞬时和连续测量的均值和标准偏差分别为0.28±0.06和0.32±0.39ɑ潜能浓度(PAEC)的未结合态份额(fp)在0至80%之间, 两种方法的均值在白天均为14%, 而用连续方法测得的24小时均值为24%。测量表明, PAEC粒度呈双态分布, 其峰的几何均值分别在0.5至1.2nm和85至200nm之间。根据测量结果用Jarues—Birchall和Jacobi—Eisfeld两个剂量模型计算了有效剂量当量转换因子。