气象因素对钉螺密度变化的影响分析

目的 研究自然条件下气象因素对钉螺密度变化的影响,为控制血吸虫病及其钉螺扩散提供科学依据。方法 收集1990－2014年湖北省潜江市春季查螺资料及地面气象观测数据,采用一阶自回归分析方法对实际钉螺密度进行趋势拟合与分解,利用相关分析法对钉螺密度变化率与不同时段、不同气象要素进行相关性分析。结果 对钉螺密度影响最大的气象因子是温度,其次为降水;其中1月平均最低气温和冬季平均最低气温分别是钉螺密度变化率、活螺框变化率影响最大的温度因子;1月平均最低温度升高(或降低)1 ℃,将会导致钉螺密度上升(或下降) 5.080%～6.710%;冬季平均最低温度升高(或降低)1 ℃,活螺框变化率上升(或下降)15.521%～15.928%。降水对钉螺密度影响最大的时段是上年11月至当年4月,该时段内降水偏少20%以上,有利于降低钉螺密度。9－11月日照与钉螺密度变化率、活螺框变化率存在一定相关性。在相关分析基础上分别建立了钉螺密度变化率、活螺框变化率与气象因子的统计回归模型。结论 在12月到来之前清除有螺区杂草有利于降低地表温度和土壤水分含量,能取得一定的灭螺效果。伴随全球气候变化湖北省冬季温度升高趋势明显,可能引发钉螺密度升高。     

乳腺癌耐药蛋白的表达及其与核转录因子snail相关性的临床研究

目的：探讨乳腺癌耐药蛋白（BCRP）的表达,分析其与核转录因子snail的相关性及BCRP介导肿瘤耐药的分子机制。方法：应用免疫组化方法检测87例乳腺癌组织和35例癌旁组织中BCRP和snail的表达情况,分析其与乳腺癌临床病理因素的关系及BCRP与snail的相关性。结果：BCRP和snail在乳腺癌组织中的阳性率分别32．18％和85．06％,BCRP与年龄、肿瘤大小及TNM分期无关,与组织学分级、ER表达和淋巴结转移相关;snail与患者年龄、肿瘤大小、组织学分级、ER表达无关,而与TMN分期、淋巴结璜移正相关;相关分析显示BCRP与snail表达的存在密切相关性（x^2=35267,P〈001,r=O643）。结论：BCRP参与了乳腺癌的进展;snail是乳腺癌上皮-间质转换（EMT）过程中的一个重要调节因素,促进了EMT的发生,介导了BCRP介导的多药耐药。     

Comparative population genetics of two invading ticks: Evidence of the ecological mechanisms underlying tick range expansions

Two species of ixodid tick, Ixodes affinis Neumann and Amblyomma maculatum Koch, are simultaneously expanding their ranges throughout the mid-Atlantic region of the US. Although we have some understanding of the ecology and life history of these species, the ecological mechanisms governing where and how new populations establish and persist are unclear. To assess population connectivity and ancestry, we sequenced a fragment of the 16S mitochondrial rRNA gene from a representative sample of individuals of both species from populations throughout the eastern US. We found that despite overlapping host preferences throughout ontogeny, each species exhibited very different genetic and geographic patterns of population establishment and connectivity. I. affinis was of two distinct mitochondrial clades, with a clear geographic break separating northern and southern populations. Both I. affinis populations showed evidence of recent expansion, although the southern population was more genetically diverse, indicating a longer history of establishment. A. maculatum exhibited diverse haplotypes that showed no significant relationship with geographic patterns and little apparent connectivity between sites. Heteroplasmy was also observed in the 16S mitochondrial rRNA gene in 3.5% of A. maculatum individuals. Genetic evidence suggests that these species rely on different key life stages to successfully disperse into novel environments, and that host vagility, habitat stability and habitat connectivity all play critical roles in the establishment of new tick populations.     

血水草生物碱对钉螺生殖腺超微结构的影响

目的观察血水草生物碱对钉螺生殖腺的影响,探讨血水草生物碱杀灭钉螺的作用机理.方法用血水草生物碱浸泡钉螺48 h,解剖钉螺,取雌、雄生殖腺以常规方法制作电镜切片,用日立H-600型透射电镜观察组织结构变化.结果血水草生物碱浸泡后,钉螺卵细胞明显萎缩,精原细胞固缩.结论血水草生物碱对钉螺的生殖腺造成严重损伤.     

A multi-group model of Schistosoma japonicum transmission dynamics and control: model calibration and control prediction

Previously we formulated a quantitative model to characterize site-specific schistosomiasis transmission. In this paper, we present a procedure to calibrate the model to data collected in endemic villages of south-western Sichuan, China, with the objective of reducing parametric uncertainty to allow the model to describe local transmission with relative confidence. A Bayesian approach using local epidemiological data and expert opinion is employed to calibrate the model. Results indicate that, after calibration, the output uncertainty is reduced substantially. The calibrated model is then used for prediction of the effects of different intervention options. Simulations reflect a bimodal transmission in both human (early summer and early fall) and snail (late summer and late fall) infections in this area, for which there is some field evidence. Also shown in the simulations are relatively high reinfection rates following chemotherapy in these endemic villages. These results suggest that a sustainable control strategy is essential in reducing transmission, and that transmission can be reduced by chemotherapy, focal snail (e.g. snail clusters) control, and egg control. Our work demonstrates the feasibility of characterizing site-specific schistosomiasis transmission using a mathematical model and a calibration approach that integrates diverse field data, and the use of the calibrated model to design control strategies.     

高原缓丘区不同土地利用方式钉螺分布与人工林抑螺效果

目的为高原缓丘区兴林抑螺提供造林模式。方法在已营建抑螺防病林（示范区）和未营建抑螺防病林（对照区）样地上按原利用方式调查钉螺,分析营造抑螺防病林对钉螺的影响。结果对照区活螺框出现率和活螺密度分别为26.81%和0.94只/0.1m2,8类土地利用方式环境钉螺活螺框出现率和活螺密度差异均有统计学意义（F=11.29、12.71,P均〈0.01）,渍水低地、水田和水旱轮作地钉螺数量较大,旱作农地和林地钉螺数量较少。与造林前相比,抑螺防病林营造5年后活螺框出现率和活螺密度降低幅度在62.70%～89.98%和74.03%～94.00%。与对照区相比,示范区活螺框出现率和活螺密度分别下降了52.04%～87.36%和52.20%～95.45%。结论高原缓丘区抑螺防病林的营建可有效控制钉螺。     

南水北调东线一期工程血吸虫病监测预警研究 Ⅲ监测预警指标和风险评估研究

目的建立南水北调东线工程血吸虫病监测预警指标体系,为东线工程血吸虫病传播风险评估和制订应急预案提供科学依据。方法采用专家咨询法和流行病学多维综合评价等方法对东线工程血吸虫病监测预警指标进行评估,以确定预警指标。结果评估研究了53个监测预警指标,其中一级指标3个,二级指标10个,三级指标40个。结果表明钉螺是南水北调东线工程血吸虫病监测预警的主要指标,其中又以钉螺孳生位置最为重要。据此建立了东线工程4个血吸虫病监测预警等级,分别为Ⅰ级：钉螺扩散进入输水河道渠首（一级泵站上）;Ⅱ级：里运河钉螺扩散越过N 32°54;′Ⅲ级：里运河钉螺扩散越过N 33°03′或越过金湖站;Ⅳ级：钉螺扩散越过N 33°15′或越过洪泽站。同时确定了4个人畜感染指标为重要的指示性指标。根据各项指标间关系,确定了东线工程血吸虫病传播风险评估方法。结论初步确定了钉螺为主、人畜感染为辅的监测预警指标体系和东线工程血吸虫病传播风险评估方法。     

普通克立格法预测江宁县江滩钉螺分布

目的　探讨江宁县江滩钉螺孳生分布的预测方法。　方法　以变异函数分析江宁县江滩钉螺分布的空间自相关性,并以此为基础用普通克立格法 (OrdinaryKriging)预测江宁县江滩钉螺的分布。　结果　 2000年江宁县江滩钉螺分布呈空间自相关性,其变异函数为球型模型,且当距离小于0.0301时,钉螺空间分布变异与距离有关。进一步以此为基础用普通克立格法建立了江宁县江滩钉螺分布预测图,交叉核验显示预测图是对江滩钉螺分布最优无偏估计,预测模型的决定系数R2=0.973。　结论　普通克立格法能有效利用监测资料预测江宁县江滩钉螺的分布状况。     

钉螺在巢湖生存繁殖的模拟试验

目的探讨钉螺在巢湖生存繁殖的可能性。方法在巢湖湖区马尾河口划定一区域,模拟巢湖环境为试验区;在血吸虫病流行区无为县姚沟镇划定一区域,模拟血吸虫病流行区环境为对照区,开展现场模拟环境钉螺生存繁殖试验。同时收集巢湖流域生态环境资料。结果巢湖流域气象条件适合钉螺生存繁殖;2007年6-12月,试验区和对照区钉螺存活率差异无统计学意义（P均〉0.05）;2007年7-12月,在试验区和对照区均捡获子代钉螺;研究期间试验区和对照区土壤湿度差异无统计学意义（U=10.00,P=0.073）。结论钉螺能够在模拟巢湖环境中生存繁殖。今后应加强对巢湖潜在钉螺孳生环境的监测,以防钉螺向湖区扩散。