共查询到20条相似文献,搜索用时 0 毫秒
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目的 探讨幽门螺杆菌(H.pylori) vacA s1m2基因型与胃黏膜肠上皮化生(IM)的关系,为萎缩性胃炎治疗及胃癌预防提供依据。方法 选取H.pylori阳性胃镜活检的石蜡包埋标本271例,包括浅表性胃炎76例(伴IM 18例)、萎缩性胃炎56例(伴IM 37例)和胃溃疡139例(伴IM 30例);提取标本中DNA,经巢式PCR方法及琼脂糖凝胶电泳对H.pylori的细胞空泡毒素基因(vacA)基因型进行检测。结果 萎缩性胃炎组中vacA s1m2亚型的检出率为53.6%(30/56),明显高于浅表性胃炎组和胃溃疡组;在271例H.pylori阳性病例中,伴IM组vacA s1m2亚型检出率为62.4%(53/85),明显高于无IM组;萎缩性胃炎病例中伴IM组vacA s1m2亚型检出率为75.7%(28/37),明显高于无IM组,同时高于浅表性胃炎伴IM组和胃溃疡伴IM组。结论 幽门螺杆菌vacA s1m2基因型与胃黏膜肠上皮化生密切相关,vacA s1m2基因型幽门螺杆菌为萎缩性胃炎相关高致病性菌株。 相似文献
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目的 探析期刊人如何在学术不端行为预防过程中起到重要作用。方法 主要采用文献法与逻辑推理法,阐述国际新型学术不端案例及现状,以Transactions on Ultrasonics,Ferroelectrics,and Frequency Control和The American Journal of Preventive Medicine两本国际期刊的编辑经验及Springer和CrossCheck为例,分析了国际期刊及相关机构对学术不端的预防措施,并提出建议。结果结果 通过学术不端现状研究,结合笔者工作经验,从编辑角度分析,提出(1)建立责任心强、专业过硬的期刊人才队伍,(2)建立期刊人自己的监督培训机构,(3)建立相应的惩罚和案例处理机制,以有效预防学术不端现象的发生。结论结论 通过期刊人才建设与素质的提高,可有效预防学术不端行为。 相似文献
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B. Koumar�� M. Achtman F. Bougoudogo M. Cisse J. F. Wang 《Bulletin of the World Health Organization》1996,74(4):375-379
The study deals with 570 strains of Neisseriaceae isolated between 1989 and 1994 in Mali: 396 of the strains were isolated from samples of cerebrospinal fluid and 174 from the throat. Serogroup C accounted for 55% of all strains. Antigenic structure was determined by ELISA, SDS-PAGE and transfer to nitrocellulose membrane for immunoblotting with monoclonal antibodies produced at the Max Planck Institute for Molecular Genetics. For serogroup A, the class 1 protein types found were P1.7 for strains isolated prior to 1994 and P1.9 for strains isolated in 1994. P1.7 is specific to clone IV-1 and P1.9 to clone III-1, which was responsible for the 1994 epidemic. All strains of serogroup C isolated from fluid CSF and most strains isolated from the throat exhibit a new type of class 1 protein which the authors have designated P1.y. P1.y is characteristic of Malian strains of serogroup C; it is rare or absent in strains from other countries (Burkina Faso, Ghana, Italy, USA). The nucleotide sequence of the gene expressing P1.y and the corresponding amino acid sequence were determined at the National Institute for Biological Standards and Control, England. 相似文献
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The missing-indicator method and conditional logistic regression have been recommended as alternative approaches for data analysis in matched case-control studies with missing exposure values. The authors evaluated the performance of the two methods using Monte Carlo simulation. Data were generated from a 1:m matched design based on McNemar's 2 x 2 tables with four scenarios for missing values: completely-at-random, case-dependent, exposure-dependent, and case/exposure-dependent. In their analysis, the authors used conditional logistic regression for complete pairs and the missing-indicator method for all pairs. For 1:1 matched studies, given no confounding between exposure and disease, the two methods yielded unbiased estimates. Otherwise, conditional logistic regression produced unbiased estimates with empirical confidence interval coverage similar to nominal coverage under the first three missing-value scenarios, whereas the missing-indicator method produced slightly more bias and lower confidence interval coverage. An increased number of matched controls was associated with slightly more bias and lower confidence interval coverage. Under the case/exposure-dependent missing-value scenario, neither method performed satisfactorily; this indicates the need for more sophisticated statistical methods for handling such missing values. Overall, compared with the missing-indicator method, conditional logistic regression provided a slight advantage in terms of bias and coverage probability, at the cost of slightly reduced statistical power and efficiency. 相似文献
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《Nutrition Clinique et Métabolisme》2006,20(2):114-117
The metabolic syndrome has a high prevalence in different countries (~ 10% in France). It associates in the same subject central obesity, decrease in HDL cholesterol, increase in plasma triglycérides, glucose intolerance and hypertension. Insulin-resistance is a common featurre even though it has been excluded from the more recent definitions because of the difficulty to assess it in clinical practice. Physiopathology of metabolic syndrome is not univocal. Stress, insulin resistance, central obesity are concerned. Its treatment must associate weight reduction and physical exercise. Fibrates could be of special interest or statins if LDL is elevated. 相似文献
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