Molecular genotyping

分子分型
  • 文章类型: Journal Article
    葡萄胎是一种异常妊娠,其中存在两个拷贝的父系遗传物质。葡萄胎妊娠分为完全葡萄胎和部分葡萄胎。临床,形态学,细胞遗传学特征通常足以区分它们,但是,了解父系起源以确定诊断和分段所必需的罕见病例?复发性自然流产妇女中因子VLeiden和G20210A凝血酶原多态性的基因突变:一项巴西人群的回顾性研究。
    Hydatidiform mole is an abnormal pregnancy in which two copies of paternal genetic material are present. Molar gestation is divided into complete and partial hydatidiform moles. Clinical, morphological, and cytogenetic characteristics are usually sufficient to distinguish them, but and the rare cases that are necessary to know the paternal origin to establish the diagnosis and segment? Mutations in the Gene for Factor V Leiden and G20210A prothrombin polymorphism in women with recurrent spontaneous abortion: a retrospective study in a Brazilian population.
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  • 文章类型: Journal Article
    将葡萄胎(HM)与非葡萄胎(NM)标本区分开来,并将HM分类为完全葡萄胎(CHM)与部分葡萄胎(PHM)对于临床实践和调查研究很重要。诊断的可重复性问题仍未解决,缺乏基于形态学的诊断准确性是实质性的,具有重要的观察者间变异性,甚至在经验丰富的妇科病理学家之间。在过去的几年中,已经研究了许多辅助技术来完善HM诊断。P57(父系印记,母体表达基因)免疫组织化学,基于CHM的独特遗传学(纯雄激素),PHM(diandric三倍体),和NM标本(双亲,具有等位基因平衡)可以识别CHMs,由于缺乏母体DNA而缺乏p57表达。然而,尽管它在HM诊断中的作用至关重要,它不允许将PHM与NM标本区分开来,由于母体DNA的存在,两者都表达p57。分子基因分型,比较绒毛和蜕膜DNA模式,以确定多态性等位基因的亲本来源和比例,将纯粹的雄激素CHM与二重三倍体PHM区分开来,这两个都来自NM标本。除了声称建立“诊断真相”之外,在使用任何辅助技术时,应牢记罕见CHM和PHM起源中的例外情况和特殊遗传情况。一种算法方法,即使在资源有限的环境中,可以帮助病理学家在妊娠早期流产的诊断困境。
    Distinction of hydatidiform moles (HM) from non-molar (NM) specimens and subclassification of HM as complete hydatidiform mole (CHM) versus partial hydatidiform mole (PHM) are important for clinical practice and investigational studies. The issue of diagnostic reproducibility is still unsolved, the lack of diagnostic accuracy based on morphology is substantial with an important interobserver variability, even between experienced gynecologic pathologists. Many ancillary techniques have been investigated in the last years to refine HM diagnosis. p57 (a paternally imprinted, maternally expressed gene) immunohistochemistry, based on the unique genetics of CHM (purely androgenetic), PHM (diandric triploid), and NM specimens (biparental, with allelic balance) can identify CHMs, which lack p57 expression because of a lack of maternal DNA. However, although its role in HM diagnosis is pivotal, it does not allow the distinction of PHM from NM specimens, both of which express p57 due to the presence of maternal DNA. Molecular genotyping, which compares villous and decidual DNA patterns to determine the parental source and ratios of polymorphic alleles, distinguishes purely androgenetic CHM from diandric triploid PHM, and both of these from NM specimens. Beyond the claim of establishing a \"diagnostic truth\", exceptions and peculiar genetic scenarios in the origin of rare CHM and PHM should be kept in mind when approaching any ancillary technique. An algorithmic approach, even in settings with limited resources, can help the pathologists in the diagnostic dilemma of diagnosis of first trimester abortions.
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  • 文章类型: Journal Article
    The globally distributed \"Beijing\" lineage of Mycobacterium tuberculosis has been associated with outbreaks worldwide. Laboratory based studies have suggested that Beijing lineage may have increased fitness; however, it has not been established whether these differences are of epidemiological significance with regards to transmission. Therefore, we undertook a systematic review of epidemiological studies of tuberculosis clustering to compare the transmission dynamics of Beijing lineages versus the non-Beijing lineages.
    We systematically searched Embase and MEDLINE before 31st December 2018, for studies which provided information on the transmission dynamics of the different M. tuberculosis lineages. We included articles that conducted population-based cross-sectional or longitudinal molecular epidemiological studies reporting information about extent of transmission of different lineages. The protocol for this systematic review was prospectively registered with PROSPERO (CDR42018088579).
    Of 2855 records identified by the search, 46 were included in the review, containing 42,700 patients from 27 countries. Beijing lineage was the most prevalent and highly clustered strain in 72.4% of the studies and had a higher likelihood of transmission than non-Beijing lineages (OR 1·81 [95% 1·28-2·57], I2 = 94·0%, τ2 = 0·59, p < 0·01).
    Despite considerable heterogeneity across epidemiological contexts, Beijing lineage appears to be more transmissible than other lineages.
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  • 文章类型: Journal Article
    BACKGROUND: Distinguishing hydatidiform moles (HMs) from nonmolar specimens and the subclassification of HM are important because complete hydatidiform mole (CHM) is associated with an increased risk of development of gestational trophoblastic neoplasia. However, diagnosis based solely on morphology has poor inter-observer reproducibility. Recent studies have demonstrated that the use of p57KIP2 immunostaining improves diagnostic accuracy for CHM.
    OBJECTIVE: To evaluate the accuracy of p57KIP2 immunostaining compared with molecular genotyping for the diagnosis of CHM.
    METHODS: Major databases were searched from inception to March 2017 using the terms \'hydatidiform mole\', \'p57\', and \'genotyping\', with their variations, and the search limit for the relevant study design.
    METHODS: Any cross-sectional study, case series, case-control study, cohort study, or clinical trial that evaluated the accuracy of p57KIP2 immunostaining for the diagnosis of CHM compared with genotyping was included. Case reports, narrative reviews, expert opinions, and animal testing were excluded.
    METHODS: Extracted accuracy data were tabulated and pooled using a hierarchical bivariate random effects model.
    RESULTS: Bivariate meta-analysis produced a summary sensitivity of 0.984 (95% CI: 0.916-1.000) and specificity of 0.625 (95% CI: 0.503-0.736) with significant heterogeneity for specificity (I2 = 71.8, chi-square P = 0.029). The pooled summary diagnostic odds ratio was 56.54 (95% CI: 11.03-289.74) with no heterogeneity (I2 = 0.00%, chi-square P = 0.67). The diagnostic performance of the test was high with an area under the curve of (AUC) 0.980.
    CONCLUSIONS: p57KIP2 immunostaining is accurate when diagnosing CHM. It can be used as an adjunct test in a combination algorithmic approach.
    UNASSIGNED: A meta-analysis to evaluate the accuracy of p57KIP2 compared with genotyping to diagnose CHM.
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  • 文章类型: Journal Article
    Distinguishing hydatidiform moles (HMs) from non-molar specimens and the subclassification of HM are important because complete hydatidiform mole (CHM) is associated with an increased risk of gestational trophoblastic neoplasia. However, diagnosis based solely on morphology has poor interobserver reproducibility. Recent studies have demonstrated that the use of p57KIP2 immunostaining improves diagnostic accuracy for CHM.
    We will conduct a systematic review of prospective and retrospective studies to evaluate the accuracy of p57KIP2 immunostaining compared with molecular genotyping for the diagnosis of CHM. A high-sensitivity search strategy will be employed in MEDLINE, EMBASE, LILACS, The Grey Literature Report, OpenGrey, OAIster, and Cochrane CENTRAL. Two reviewers will independently screen all identified references for eligibility and extract data. The methodological quality and bias of the included studies will be assessed according to the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool, and the overall quality of evidence will be assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. If a meta-analysis is possible, pooled estimates of sensitivity, specificity, and positive and negative likelihood ratios will be calculated using bivariate random-effects models. Statistical heterogeneity will be evaluated with I 2 statistics and explored through sensitivity analysis.
    There is considerable overlap between the histological features of molar and non-molar pregnancies and between complete and partial HMs, which results in significant interobserver variability in the diagnosis of CHM and its mimics. Therefore, molecular techniques are used to correctly diagnosis and treat CHM. However, these molecular diagnostic methods are technically difficult to perform, relatively costly, and unavailable in most pathology laboratories. According to our results, p57KIP2 immunostaining appears to be a practical and accurate adjunct for the diagnosis of CHM and its mimics because this technique is relatively simple, reliable, cost-efficient, and rapid. This systematic review will help to determine whether p57KIP2 immunostaining is an adequate alternative diagnostic test for CHM.
    PROSPERO CRD42015024181.
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