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1.
上海市区女性肺癌的家族聚集性研究   总被引:9,自引:1,他引:8  
我们利用在上海市区所开展的一项关于女性肺癌的较大规模人群基础上的病例对照研究资料,分析和评价了一级亲属患肺癌史者其在肺癌发生中的作用。文中重点分析了女性非吸烟者肺癌的材料。结果表明,先证者家系一级亲属患肺癌的风险性是对照组家系一级亲属的近3倍(OR=2.80,95% CI1.68-4.67)。对非吸烟先证者家系而言,比数比为2.62(95%CI1.52-4.5 2)。其中,腺癌、鳞癌、其他类和不明分类的肺癌的OR分别为2.79(95%CI 1.53-5.10)、3.88 (95%CI1.42-10.63)、1.26(95%CI0.27-6.01)、2.52 (95%CI1.16-5.49)。按年龄组分层分析的结果显示,35-59岁组与60-69岁组的比数比分别为4.01 (95%CI1.71-8.97)、 1.89(95%CI0.89-3.98)。非吸烟女性研究对象经多因素非条件logistic回归模型的分析后,比数比OR为2.71(95%CI1.54-4.76),有高度统计学意义。在该多变量回归模型的基础上估计的调整人群归因风险度为5.31%。 Abstract:The data set of a large population-based case-control study of female lung cancer conducted in Shanghai urban was used to investigate the contribution of lung cancer in first-degree relatives to lung cancer risk.The analysis in the paper is emphasized on non-smoking women.The results indicates that the risk of first-degree relatives with lung cancer is increased about 30fold(OR=2.80,95% CI:1.68-4.67),and for non-smoking probands the OR is 2.62(95% CI:1.52-4.52).The odds ratios of adeno-carcinoma,squamous cell carcinoma,others unknown of lung cancer are 2.79(95% CI:1.53-5.10),3.88(95% CI:1.42-10.63),1.26(95% CI:0.27-6.01),2.52(95% CI:1.16-5.49),respectively.For cases of age groups of 35 to 59 and 60 to 69 years of probands,with ORs of 4.01(95% CI:1.79-8.97)and 1.89(95% CI:0.89-3.98)respectively.The odds ratio from multivariable unconditional logistic regression is 2.71(95% CI:1.54-4.76).The estimation of adjusted population attributable risk is 5.31% based on the multivariable logistic regression model analysis.  相似文献   

2.
Summary Identifying regions with the highest and lowest mortality rates and producing the corresponding color‐coded maps help epidemiologists identify promising areas for analytic etiological studies. Based on a two‐stage Poisson–Gamma model with covariates, we use information on known risk factors, such as smoking prevalence, to adjust mortality rates and reveal residual variation in relative risks that may reflect previously masked etiological associations. In addition to covariate adjustment, we study rankings based on standardized mortality ratios (SMRs), empirical Bayes (EB) estimates, and a posterior percentile ranking (PPR) method and indicate circumstances that warrant the more complex procedures in order to obtain a high probability of correctly classifying the regions with the upper 100γ% and lower 100γ% of relative risks for γ= 0.05, 0.1 , and 0.2. We also give analytic approximations to the probabilities of correctly classifying regions in the upper 100γ% of relative risks for these three ranking methods. Using data on mortality from heart disease, we found that adjustment for smoking prevalence has an important impact on which regions are classified as high and low risk. With such a common disease, all three ranking methods performed comparably. However, for diseases with smaller event counts, such as cancers, and wide variation in event counts among regions, EB and PPR methods outperform ranking based on SMRs.  相似文献   

3.
BackgroundAntiretroviral therapy (ART) has reduced AIDS-defining cancer (ADC) mortality, but its effect on non-AIDS-defining cancer (NADC) mortality is unclear. To help inform cancer prevention and screening, we evaluated trends in NADC mortality among people with AIDS (PWA) in the ART era.MethodsThis retrospective cohort study analyzed AIDS surveillance data, including causes of death from death certificates, for PWA in San Francisco who died in 1996–2013. Proportional mortality ratios (PMRs), and year, age, race, sex-adjusted standardized mortality ratios (SMRs) were calculated for 1996–1999, 2000–2005, and 2006–2013, corresponding to advances in ART.ResultsThe study included 5822 deceased PWA of whom 90% were male and 68% were aged 35–54 at time of death. Over time, the PMRs significantly decreased for ADCs (2.6%, 1.4%, 1.2%) and increased for NADCs (4.3%, 7.0%, 12.3%). For all years combined (1996–2013) and compared to the California population, significantly elevated SMRs were observed for these cancers: all NADCs combined (2.1), anal (58.4), Hodgkin lymphoma (10.5), liver (5.2), lung/larynx (3.0), rectal (5.2), and tongue (4.7). Over time, the SMRs for liver cancer (SMR 19.8, 11.2, 5.0) significantly decreased while the SMRs remained significantly elevated over population levels for anal (SMR 123, 48.2, 45.5), liver (SMR 19.8, 11.2, 5.0), and lung/larynx cancer (SMR 5.3, 4.7, 3.6).ConclusionA decline in ADC PMRs and increase in NADC PMRs represent a shift in the cancer burden, likely due to ART use. Moreover, given their elevated SMRs, anal, liver, and lung/larynx cancer remain targets for improved cancer prevention, screening, and treatment.  相似文献   

4.
In recent years, there has been an increased awareness of the potential one-sided nature of many testing problems in applied sciences. Usually, these testing problems can be reduced, either by conditioning on sufficient statistics or by invariant techniques. COX and SOLOMON (1988) considered testing the serial correlation coefficient of a stationary first order autoregressive process and concentrated on four independent samples, with each of size three. We outline a general method for testing the serial correlation coefficient, using locally best invariant, point optimal invariant and locally most mean powerful invariant test procedures. The first procedure optimizes power near the null hypothesis, the second optimizes it at a pre-determined point away from the null while the third optimizes the average curvature of the power hypersurface in the neighbourhood of the null hypothesis.  相似文献   

5.
Despite the success of extensive control measures that have been implemented in China for over 50 years, the number of individuals infected with Schistosoma japonicum remains high in the existing endemic areas. A variance components analysis was undertaken to estimate the heritable and environmental components that contribute to S. japonicum infection in the Poyang Lake region of Jiangxi Province, PR China. The total target population was 3148 from four separate administrative villages. Two thousand seven hundred and five of these comprised 400 families ranging in size from 3 to 188. After adjustments were made for gender, water contact and past history of having had schistosomiasis, the heritable component was estimated to account for as much as 58% of the phenotype variation under the polygenic model. Household was not shown to be an important environmental factor. Incorporating village effects indicated that the results were valid for the total population. We conclude that genetic heritability in this region is high and plays an important role in determining risk of infection with S. japonicum.  相似文献   

6.
The Asia-Pacific region is a home to 60% of the population in the world and to approximately one quarter of people with HIV/AIDS. Close to a million of people has been infected and a half million people died of AIDS annually in Asia,becoming the second largest epicenter of global AIDS epidemic. Molecular epidemiology has been useful tool to track a course of HIV spread. In-depth knowledge from the studies on molecular epidemiology elucidates the dynamics of HIV spread and the interrelationship of epidemics in the different regions in Asia.  相似文献   

7.
The Asia-Pacific region is a home to 60% of the population in the world and to approximately one quarter of people with HIV/AIDS. Close to a million of people has been infected and a half million people died of AIDS annually in Asia, becoming the second largest epicenter of global AIDS epidemic. Molecular epidemiology has been useful tool to track a course of HIV spread. In-depth knowledge from the studies on molecular epidemiology elucidates the dynamics of HIV spread and the interrelationship of epidemics in the different regions in Asia. Foundation items: Grant support from Ministry of Health, Labour and Welfare and Ministry of Education, Science and Technology in Japan; Japanese Foundation for AIDS Prevention.  相似文献   

8.
Simulations are used to compare four statistics for the detection of a quantitative trait locus (QTL) in daughter and grand-daughter designs as defined by Soller and Genizi (1978) and Weller et al. (1990): (1) the Fisher test of a linear model including a marker effect within sire or grand-sire effect; (2) the likelihood ratio test of a segregation analysis without the information given by the marker; (3) the likelihood ratio test of a segregation analysis considering the information from the marker; and (4) the lod score which is the likelihood ratio test of absence of linkage between the marker and the QTL. In all cases the two segregation analyses are more powerful for QTL detection than are either the linear method or the lod score. The differences in power are generally limited but may be significant (in a ratio of 1 to 3 or 4) when the QTL has a small effect (0.2 standard deviations) and is not closely linked to the marker (recombination rate of 20% or more).  相似文献   

9.
BackgroundHigh lipoprotein (a) level is an established cardiovascular risk, but its association with non-cardiovascular diseases, especially cancer, is controversial. Serum lipoprotein (a) levels vary widely by genetic backgrounds and are largely determined by the genetic variations of apolipoprotein (a) gene, LPA. In this study, we investigate the association between SNPs in LPA region and cancer incidence and mortality in Japanese.MethodsA genetic cohort study was conducted utilizing the data from 9923 participants in the Japan Public Health Center-based Prospective Study (JPHC Study). Twenty-five SNPs in the LPAL2-LPA region were selected from the genome-wide genotyped data. Cox regression analysis adjusted for the covariates and competing risks of death from other causes, were used to estimate the relative risk (hazard ratios (HR) with 95% confidence intervals (CI)) of overall and site-specific cancer incidence and mortality, for each SNP.ResultsNo significant association was found between SNPs in the LPAL2-LPA region and cancer incidence or mortality (overall/site-specific cancer). In men, however, HRs for stomach cancer incidence of 18SNPs were estimated higher than 1.5 (e.g., 2.15 for rs13202636, model free, 95%CI: 1.28–3.62) and those for stomach cancer mortality of 2SNPs (rs9365171, rs1367211) were estimated 2.13 (recessive, 95%CI:1.04–4.37) and 1.61 (additive, 95%CI: 1.00–2.59). Additionally, the minor allele for SNP rs3798220 showed increased death risk from colorectal cancer (CRC) in men (HR: 3.29, 95% CI:1.59 – 6.81) and decreased CRC incidence risk in women (HR: 0.46, 95%CI: 0.22–0.94). Minor allele carrier of any of 4SNPs could have risk of prostate cancer incidence (e.g., rs9365171 dominant, HR: 1.71, 95%CI: 1.06–2.77).ConclusionsNone of the 25 SNPs in the LPAL2-LPA region was found to be significantly associated with cancer incidence or mortality. Considering the possible association between SNPs in LPAL2-LPA region and colorectal, prostate and stomach cancer incidence or mortality, further analysis using different cohorts is warranted.  相似文献   

10.
Chen  Xiangpeng  Zhu  Yun  Wang  Wei  Li  Changchong  An  Shuhua  Lu  Gen  Jin  Rong  Xu  Baoping  Zhou  Yunlian  Chen  Aihuan  Li  Lei  Zhang  Meng  Xie  Zhengde 《中国病毒学》2021,36(6):1475-1483
Virologica Sinica - Human respiratory syncytial virus (RSV) is a major pathogen of acute lower respiratory tract infection among young children. To investigate the prevalence and genetic...  相似文献   

11.
张力斌  何明珠  张珂 《生态学报》2023,43(16):6627-6636
氮(N)和磷(P)元素在生态系统的结构和功能、稳定性、服务价值和可持续发展中起着关键作用。但自工业革命以来,全球气候变化受人类活动影响愈加剧烈。气候变化不同程度的影响干旱和半干旱区的氮磷循环过程,进而改变植物个体生物量积累以及植被生产力。因此,探究荒漠植物的生物量积累与分配规律对氮、磷添加的响应机制,有助于深入理解干旱区植物应对大气氮磷沉降等气候变化的适应策略。以荒漠植物柠条锦鸡儿(Caragana korshinskii Kom.,以下简称柠条)为研究对象,通过养分添加控制实验研究柠条地上/地下生物量的积累和分配,揭示其异速生长规律。实验包括3种形态的氮素添加(NH4+、NH4NO3、NO3-)和1种磷素添加(H2PO4-),分别对应4个浓度梯度(4 g/m2、8 g/m2、16 g/m2和32 g/m2)。结果表明,NO3-添加对柠条生物量有显著影响,但不同浓度对柠条生物量的影响无显著差异;单独的NH4+添加对柠条地上/地下部分生长都具有显著抑制作用,且抑制作用与添加浓度呈显著的正相关关系;NH4NO3添加初期对柠条地上/地下生物量均具有促进作用,但这种促进作用会随着柠条生长和后期NH4NO3添加浓度的增加而消失;高浓度NH4NO3添加量(32 g/m2)会抑制柠条的生长。低浓度(4 g/m2、8 g/m2)外源氮添加会使柠条的生物量主要优先配给地下部分;磷添加则会使柠条的生物量分配策略向地上部分倾斜。综上所述,研究结果表明柠条改变地上和地下的生物量分配策略以响应氮或/和磷沉降。这一结论不仅增强了我们对植物生长策略的认识,而且有助于我们揭示全球气候变化条件下干旱地区土壤与植物之间的氮、磷循环和转化。  相似文献   

12.
13.
Rittgen W  Becker N 《Biometrics》2000,56(4):1164-1169
The evaluation of epidemiological follow-up studies is frequently based on a comparison of the number O of deaths observed in the cohort from a specified cause with the expected number E calculated from person years in the cohort and mortality rates from a reference population. The ratio SMR = 100 x O/E is called the standardized mortality ratio (SMR). While person years can easily be calculated from the cohort and reference rates are generally available from the national statistical offices or the World Health Organization (WHO), problems can arise with the accessibility of the causes of death of the deceased study participants. However, the information that a person has died may be available, e.g., from population registers. In this paper, a statistical model for this situation is developed to derive a maximum likelihood (ML) estimator for the true (but unknown) number O* of deaths from a specified cause, which uses the known number O of deaths from this cause and the proportion p of all known causes of death among all decreased participants. It is shown that the standardized mortality ratio SMR* based on this estimated number is just SMR* = SMR/p. Easily computable confidence limits can be obtained by dividing the usual confidence limits of the SMR by the opposite limit of the proportion p. However, the confidence level alpha has to be adjusted appropriately.  相似文献   

14.
通过系统进化树的构建对IPP异构酶的系统发育进行分析研究。结果表明,不同来源的IPP异构酶基因均是单系分支,并且各个分支有着不同进化模式;似然比分析结果发现,绿藻来源的IPP异构酶有9.8%的氨基酸位点经受了正选择的压力,其基因的进化模式不同于高等植物和细菌中的IPP异构酶基因。  相似文献   

15.
郭伟  冯荣锦 《遗传学报》2006,33(1):12-18
在渐近混合模型中,混合现象发生在每一世代,通过对其混合连锁不平衡的理论分析,发现混合连锁不平衡与两个子群体间的基因频率差成正比。基于这一点,构造了一个对重组率严格单调的函数(△ker=△/(p1-p2),其中△代表连锁不平衡),进而据此推断标记基因座与疾病基因座的遗传连锁。应用人类基因组上不连锁的标记基因提供的连锁不平衡信息,基于病人组数据构造了一个准似然比统计量。模拟结果显示,此检验可用于精确的基因定位。文章亦讨论了参数对检验的影响。  相似文献   

16.
Through the theoretical analysis of the admixture linkage disequilibrium (ALD) in the gradual admixture (GA) model, in which admixture occurs in every generation, the ALD is found to be proportional to the difference in marker allele frequencies, p1-p2, between two subpopulations. Based on this property, we can employ a strict monotonic function (Δker=Δ/(p1-p2), where Δ denotes the linkage disequilibrium (LD)) of the recombination fraction between the marker locus and the disease locus to infer the true genetic linkage. We construct a quasi likelihood ratio test (LRT) for the case-only data utilizing the information of unlinked markers in the human genome. The simulation results show that our tests can be used to fine map a disease locus. The effects of parameter values in the ALD mapping are also discussed.  相似文献   

17.
The probability of detecting possible late effects of ionizing radiation in human populations depends on the size of exposure in the study population and on the epidemiologic evaluation method used. This is not only due to the mathematical or statistical properties of the method, but also to the choice of the control population, which may be either external (usually large) or internal (usually not so large). Moreover, the use of a large external control population often results in an increasing influence of selection factors expressing themselves e.g. through the ‘healthy worker’ effect. In this paper three different methods usually employed in follow-up studies are reviewed: the calculation of Standardized Mortality Ratios (SMR), a contingency table analysis based on Person-Years (PY) and the comparison of Cumulative Mean Doses (CMD) within different subcohorts. The methods are illustrated with a simple radiation risk model; nevertheless, most of the conclusions apply to non-radiation risk studies as well. The CMD-method is shown to be heavily selection sensitive.  相似文献   

18.
Advanced-generation domestication programs for forest-tree species has raised some concerns about the maintenance of genetic diversity in forest-tree breeding programs. Genetic diversity in natural stands was compared with two genetic conservation options for a third-generation elite Pinus taeda breeding population. The breeding population was subdivided either on the basis of geographic origin and selection goals (multiple-population or MPBS option) or stratified according to genetic value (hierarchical or HOPE option). Most allelic diversity in the natural stands of loblolly pine is present in the domesticated breeding populations. This was true at the aggregate level for both multiple-population (MPBS) and the hierarchical (HOPE) populations. Individual subpopulations within each option had less genetic diversity but it did not decline as generations of improvement increased. Genetic differentiation within the subdivided breeding populations ranged from 1 to 5%, genetic variability is within each subpopulation rather than among subpopulations for both MPBS (>95%) and the HOPE approaches (>98%). Nei's Gst estimates for amongpopulation differentiation were biased upwards relative to estimates of from Weir and Cockerham (1984).  相似文献   

19.
The family Fagaceae includes several species and presents huge genetic variability. In the last two decades, several genetic studies about phylogenetics and genetic diversity of Fagaceae have emerged. ISSR markers were used to evaluate the genetic diversity of 26 species of Fagaceae belonging to the genera Castanea, Fagus and Quercus. Among several primers tested, 17 were selected for the evaluation of diversity and estimation of genetic relationships. A total of 371 ISSR markers were produced and each primer revealed high polymorphism. Specific ISSR markers for the Quercus infrageneric groups were amplified. ISSRs proved to be a reliable tool for the discrimination of the analyzed species per genus, infrageneric group and/or ecological origin.  相似文献   

20.
Sex allocation theory predicts that parents should bias their reproductive investments toward the offspring sex generating the greatest fitness return. When females are the heterogametic sex (e.g., ZW in butterflies, some lizards, and birds), production of daughters is associated with an increased risk of offspring inviability due to the expression of paternal, detrimental recessives on the Z chromosome. Thus, daughters should primarily be produced when mating with partners of high genetic quality. When female sand lizards (Lacerta agilis) mate with genetically superior males, exhibiting high MHC Class I polymorphism, offspring sex ratios are biased towards daughters, possibly due to recruitment of more Z-carrying oocytes when females have assessed the genetic quality of their partners. If our study has general applicability across taxa, it predicts taxon-specific sex allocation effects depending on which sex is the heterogametic one.  相似文献   

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