恶性疟原虫abstrakt同源基因的克隆及DEAD盒家族蛋白的序列分析

DEAD盒蛋白家族的ATP依赖性的RNA解旋酶类参与细胞内几乎所有的RNA代谢过程 ,在几乎所有生物的细胞生长发育过程中扮演着众多不可或缺的角色。在本实验中 ,通过PCR和探针杂交相结合的筛选方法 ,筛选恶性疟原虫 (Plasmodiumfalciparum)的基因组文库 ,克隆了FH1F———abstrakt同源基因的完整序列。通过搜索已经完成测序的恶性疟原虫基因组数据库 ,推测FH1F序列定位在第 5条染色体上。FH1F全长2 80 4bp,包含一个 1 1 6 1bp的完整阅读框 ,编码一个由 386个氨基酸组成的蛋白。对FH1F蛋白序列用BlastP进行搜索和分析以及用DNAStar与许多典型的DEAD盒蛋白序列进行比对分析 ,结果均提示FH1F蛋白应该是DEAD盒家族的一个Abstrakt蛋白。另一方面 ,用DNAStar对已知所有完整的DEAD盒蛋白进行详细的序列分析以及用Mega对这些序列进行系统发育研究的结果都显示 :DEAD盒家族的蛋白聚类成为若干不同的亚群 ;与DEAD盒蛋白的一般保守序列相比 ,Abstrakt,eIF 4A ,Vasa ,P6 8等不同亚群的DEAD盒蛋白在保守区具有各自不同的结构特征。本文对不同的DEAD盒蛋白的结构特征进行了总结并试图给出不同亚群分类上的结构标准 ,对Abstrakt蛋白在本应高度保守的位点上异常于其它DEAD盒蛋白的氨基酸残基的取代也进行了相关的初步分析     

牙龈卟啉杆菌W83单克隆抗体的研制与鉴定

牙龈类杆菌曾是重要的产黑色素类杆菌群菌株,最近重新命名为牙龈卟啉杆菌,该菌为牙周病龈下菌斑中关键性厌氧菌,与成人慢性牙周炎的发生、发展有密切关系。作者用牙龈卟啉杆菌侵袭型菌株W83,作为免疫原,通过免疫小鼠、细胞融合、筛选、克隆化,最后得到一株能够稳定分泌抗牙龈卟啉杆菌W83的单克隆抗体杂交瘤细胞系,经鉴定该单抗特异性良好,可用于临床该菌的检出和生态学研究。     

Linkage disequilibrium over short physical distances measured in sheep using a high‐density SNP chip

The extent of linkage disequilibrium (LD) between genetic loci has implications for both association studies and the accuracy of genomic prediction. To characterise the persistence of LD in diverse sheep breeds, two SNP genotyping platforms were used. First, existing SNP genotypes from 63 breeds obtained using the ovine SNP50 BeadChip (49 034 loci) were used to estimate LD decay in populations with contrasting levels of genetic diversity. Given the paucity of marker pairs separated by short physical distances on the SNP50 BeadChip, genotyping was subsequently performed for four breeds using the recently developed ovine HD BeadChip that assays approximately 600 000 SNPs with an average genomic spacing of 5 kb. This facilitated a highly accurate estimate of LD over short genomic distances (<30 kb) and revealed LD varies considerably between sheep breeds. Further, sheep appear to contain generally lower levels of LD than do other domestic species, likely a reflection of aspects of their past population history.     

农药亚致死剂量对小菜蛾及优姬蜂种群动力学的影响(英文)

本研究通过用农药农蒙特(25×10~(-6))和氯氰菊酯(20×10~(-6))处理,采用生命表技术和控制效应来评判农药亚致死剂量对田间小菜蛾和优姬蜂种群动力学的影响。结果表明,农蒙特和氯氰菊酯对优姬蜂种群的控制效应大于对小菜蛾种群的控制效应,寄生在农蒙特处理的小菜蛾幼虫体内的优姬蜂幼虫的死亡率显著地高于氯氰菊酯处理的和对照的,表现出农蒙特对寄生蜂影响的深远性。     

Reduction in Malaria Incidence following Indoor Residual Spraying with Actellic 300 CS in a Setting with Pyrethroid Resistance: Mutasa District,Zimbabwe

Background

More than half of malaria cases in Zimbabwe are concentrated in Manicaland Province, where seasonal malaria epidemics occur despite intensified control strategies. Recently, high levels of pyrethroid and carbamate resistance were detected in Anopheles funestus, the major malaria vector in eastern Zimbabwe. In response, a single round of indoor residual spraying (IRS) using pirimiphos-methyl (an organophosphate) was implemented in four high burden districts of Manicaland Province from November 1, 2014 to December 19, 2014. The objective of this study was to evaluate the effect of this programmatic switch in insecticides on malaria morbidity reported from health care facilities in Mutasa District, one of the worst affected districts in Manicaland Province.

Methods

The number of weekly malaria cases for each health facility 24 months prior to the 2014 IRS campaign and in the subsequent high transmission season were obtained from passive case surveillance. Environmental variables were extracted from remote-sensing data sources and linked to each health care facility. Negative binomial regression was used to model the weekly number of malaria cases, adjusted for seasonality and environmental variables.

Results

From December 2012 to May 2015, 124,206 malaria cases were reported from 42 health care facilities in Mutasa District. Based on a higher burden of malaria, 20 out of 31 municipal wards were sprayed in the district. Overall, 87.3% of target structures were sprayed and 92.1% of the target population protected. During the 6 months after the 2014 IRS campaign, a period when transmission would have otherwise peaked, the incidence of malaria was 38% lower than the preceding 24 months at health facilities in the sprayed wards.

Conclusions

Pirimiphos-methyl had a measurable impact on malaria incidence and is an effective insecticide for the control of An. funestus in eastern Zimbabwe.     

基质金属蛋白酶在乳腺癌上皮间质转化中的作用

基质金属蛋白酶(matrix metalloproteinase,MMP)能够分解并修饰细胞外基质及细胞连接,促进上皮细胞从周围组织中分离出来。在乳腺癌中MMP表达量升高,刺激肿瘤发生,引起癌症细胞的入侵和转移。上皮细胞-间质细胞转化(epithelial-mesenchymal transition,EMT)的激活与肿瘤的发生也有关。最近的研究表明MMP在乳腺的发育和致病的EMT过程中充当促进因子和介质的角色。本文主要概括最新的关于MMP是如何调节乳腺癌细胞的运动、入侵和EMT所驱动的乳腺癌发育的研究,为更好地理解MMP在乳腺癌发病过程中的作用提供依据。     

神经元迁移的细胞和分子机制

在脑的发育过程中,神经元的正确迁移是正常脑组织发生的一个必不可少的环节。在过去的几十年中,通过不同的学科方法,对于神经元迁移的机制有了较好的理解。在细胞水平上,神经元迁移需要3个重复事件的精确调控;在分子水平,与神经元迁移相关的胞外信号分子已经被鉴定,而且大量的胞内信号通路也已经被阐明。     

Depressive symptoms and gender differences in older adults in Hong Kong during the COVID-19 pandemic: a network analysis approach

Background: The 2019 novel coronavirus disease (COVID-19) outbreak had a detrimental impact on the mental health of older adults. This study evaluated the central symptoms and their associations in the network of depressive symptoms and compared the network structure differences between male and female older adults in Hong Kong.Methods: Altogether, 3,946 older adults participated in this study. We evaluated the centrality indicators for network robustness using stability and accuracy tests, and examined the potential differences between the structure and connectivity of depression networks in male and female older adults.Results: The overall prevalence of depressive symptoms was 43.7% (95% CI=40.6-46.7%) in males, and 54.8% (95% CI=53.1-56.5%) in females (P<0.05). Sad Mood, Guilt, Motor problems and Lack of Energy were influential symptoms in the network model. Gender differences were found in the network global strength, especially in the following edges: Sad Mood--Guilt, Concentration--Guilt, Anhedonia--Motor, Lack of Energy--Suicide, Appetite--Suicide and Concentration--Suicide.Conclusions: Central symptoms in the depressive symptom network among male and female older adults may be prioritized in the treatment and prevention of depression during the pandemic.