2型糖尿病易感基因SNP位点对生活方式干预降低血糖应答效果的修饰效应

近年来的研究发现,一些2型糖尿病(type 2 diabetes mellitus,T2DM)易感基因位点不仅与T2DM的发病风险有关,还会影响生活方式干预效果。为进一步探究T2DM易感基因单核苷酸多态性(single nucleotide polymorphism,SNP)位点对生活方式干预降低高危人群血糖应答效果的修饰作用,本课题组在德清农村社区开展了生活方式干预试验(2017年6月~12月,对干预组的研究对象进行强化生活方式干预,对照组仅接受常规健康知识宣教),并对研究对象进行SNP基因分型。研究发现,对于rs9502570,干预组中的CC+CT基因型人群的空腹血糖降低值显著高于TT基因型(P=0.031);干预组中CC+CT基因型人群的糖化血红蛋白值降低值为0.03%,TT基因型人群的糖化血红蛋白值升高了0.27%(P=0.012);CC+CT和TT基因型干预组和对照组的空腹血糖和糖化血红蛋白前后差值差之间也有统计学差异(均为P<0.001)。对于rs10811661,干预组中TT基因型人群的空腹血糖降低值显著高于CC+CT基因型(P=0.021);TT和CC+CT基因型干预组和对照组的空腹血糖前后差值差之间亦有统计学差异(P<0.001)。上述研究结果表明,rs9502570、rs10811661两个位点会在一定程度上修饰高危人群对T2DM生活方式干预降低血糖的应答效果,为今后进一步研制糖尿病高危人群个体化干预措施提供了客观依据。

临床诊断标准实施和全城症状排查对武汉新冠病毒肺炎疫情防控的效果评价

自新型冠状病毒肺炎(coronavirus disease 2019, COVID-19)疫情发生以来,中国大多数的病例集中在武汉市。虽然早期病例数和死亡人数迅速增加,但通过采取多种防控措施,疫情得以快速遏制。纵观全球,疫情已蔓延至全球六大洲的187个国家,确诊病例数已超过300万,这一数字仍在快速增长。在此特殊背景下,有必要对我国疫情防控措施开展科学的、定量的评估,为全球疫情防控提供决策依据。为此,本研究评估了临床诊断标准实施和全城症状排查对武汉市疫情控制的贡献。考虑COVID-19的传播机理、隔离措施等,建立SEIR+Q传播动力学模型。基于武汉市截至2020年2月14日官方公布的每日确诊病例数和未确诊的临床诊断病例数进行建模,并预测2月14日以后的疫情态势。基于实际疫情数据,与模型预测趋势相比较,评价防控措施效果。结果显示,若维持2月14日以前防控措施不变,那么预测将于3月25日和4月29日,每日新增病例数分别降至100例和10例以下,将于5月31日首次现零。而事实上,截至3月6日,武汉市每日新增病例数降至100例以下,截至3月11日降至10例以下,3月18日首次实现零增长,较之模型预测结果分别提前了19 d、49 d和74 d。截至3月30日,实际累计病例数为50 006例,比模型预测值减少19 951例。有效再生数[effective reproductive number, R(t)]分析显示,2月6-10日的第一次全城症状排查后,R(t)显现出下降趋势,2月12-14日的临床诊断标准实施和2月17-19日的第二次全城症状排查后,R(t)显现出较大的降幅,与实际情况较为一致。综上所述,武汉市临床诊断标准的实施和全城症状排查等综合防控措施成效显著,可为世界各国的疫情防控决策提供科学依据。

Three Gorges Dam:the changing trend of snail density in the Yangtze River basin between 1990 and 2019

Background The area of Oncomelania hupensis snail remains around 3.6 billion m^(2),with newly emerging and reemergent habitats continuing to appear in recent years.This study aimed to explore the long-term dynamics of snail density before and after the operation of Three Gorges Dam(TGD).Methods Data of snail survey between 1990 and 2019 were collected from electronic databases and national schistosomiasis surveillance.Meta-analysis was conducted to estimate the snail density.Joinpoint model was used to identify the changing trend and inflection point.Inverse distance weighted interpolation(IDW)was used to determine the spatial distribution of recent snail density.Results A total of 3777 snail survey sites with a precise location of village or beach were identified.For the downstream area,snail density peaked in 1998(1.635/0.11 m^(2),95%CI:1.220,2.189)and fluctuated at a relatively high level before 2003,then declined steadily from 2003 to 2012.Snail density maintained lower than 0.150/0.11 m^(2) between 2012 and 2019.Joinpoint model identified the inflection of 2003,and a significant decreasing trend from 2003 to 2012 with an annual percentage change(APC)being−20.56%(95%CI:−24.15,−16.80).For the upstream area,snail density peaked in 2005(0.760/0.11 m^(2),95%CI:0.479,1.207)and was generally greater than 0.300/0.11 m2 before 2005.Snail density was generally lower than 0.150/0.11 m^(2) after 2011.Snail density showed a significant decreasing trend from 1990 to 2019 with an APC being−6.05%(95%CI:−7.97,−7.09),and no inflection was identified.IDW showed the areas with a high snail density existed in Poyang Lake,Dongting Lake,Jianghan Plain,and the Anhui branch of the Yangtze River between 2015 and 2019.Conclusions Snail density exhibited a fluctuating downward trend in the Yangtze River basin.In the downstream area,the operation of TGD accelerated the decline of snail density during the first decade period,then snail density fluctuated at a relatively low level.There still exists local areas with a high snail density.Long-term control and monitoring of snails need to be insisted on and strengthened.

Using RAPD in Neisseria gonorrhoeae genotyping and transmission detection

The aim of this paper is to develop an applic-able Random Amplified Polymorphic DNAs(RAPD)method for genotyping Neisseria gonorrhoeae strain,and discuss the possibility of using the RAPD method to trace N.gonorrhoeae strain transmission route.Four different pretreatment methods were used on the N.gonorrhoeae genomic DNA component,and the best adaptive extract method was selected for RAPD.Different RAPD primers sequence was used for amplification and their differenti-ating capabilities for N.gonorrhoeae strains were com-pared.Applicable RAPD primer was selected for N.gonorrhoeae genotyping and then applied into transmis-sion detection.The results show that the so called cetyl-trimethylammonium bromide(CTAB)method for extracting genomic DNA could give integrated genomic DNA and give out relatively better RAPD fingerprint maps,subsequently,using selected RAPD primer could give out a group of amplification polymerase chain reac-tion bands.The fingerprint maps from different N.gonor-rhoeae strains were distinctive.Some main segments were common to all the N.gonorrhoeae strains tested.Some segments were different among the N.gonorrhoeae strains.According to the fingerprint maps and similarity index of different N.gonorrhoeae isolates,isolates from a pair of sex-partners were very similar.Based on these findings,the best extracting method and suitable RAPD primer were chosen.The RAPD fingerprint maps could type N.gonorrhoeae effectively and could be used as an additional approach in molecular epidemiology for tracing infection sources.

Omicron:a chimera of two early SARS-CoV-2 lineages

Dear Editor,The outbreak of the COVID‐19 that occurred in late 2019 has posed a remarkable threat to public health around the world.It is known that SARS-CoV-2 is a genetically diverse group that mutates continuously,leading to the emergence of multiple variants.1 Potential variants of concern(VOCs),variants of interest(VOIs),or variants under monitoring(VUMs)are regularly assessed based on the risk posed to global public health.Following the identification of a novel variant in South Africa on 24 November 2021,WHO designated Omicron(clade GRA,PANGO lineage B.1.1.529 and descendants BA.1 and BA.2)as the fifth SARS-CoV-2 VOC 2 days later due to its large number of variations.