molecular diagnostic methods

  • 文章类型: Journal Article
    脊髓小脑共济失调(SCAs)是一种罕见的常染色体显性神经退行性疾病。迄今为止,已经表征了大约50种不同的SCA亚型。SCA的流行类型通常是PolyQ起源的,其中疾病病理是多个谷氨酰胺残基被编码到疾病蛋白上的结果,导致扩张。SCAs2和3是最常见的诊断亚型,其中受影响的患者表现出某些特征性的生理表现,如步态共济失调和构音障碍。然而,其他临床体征是这些亚型所独有的.最近,已经开发了多种分子诊断方法来鉴定和表征这些亚型。尽管取得了这些进步,SCAs的分子病理学仍然未知。为了进一步理解神经退行性SCAs2和3的机制,基于患者来源的诱导多能干细胞(iPSC)的建模是一个引人注目的途径。我们涵盖了以下基于iPSC的SCA亚型2和3的体外疾病建模的现状,连同创建的细胞系列表,以及研究结果与个性化自体治疗的相关性。
    Spinocerebellar ataxias (SCAs) are a rare autosomal dominant neurodegenerative disorder. To date, approximately 50 different subtypes of SCAs have been characterized. The prevalent types of SCAs are usually of PolyQ origin, wherein the disease pathology is a consequence of multiple glutamine residues being encoded onto the disease proteins, causing expansions. SCAs 2 and 3 are the most frequently diagnosed subtypes, wherein affected patients exhibit certain characteristic physiological manifestations, such as gait ataxia and dysarthria. Nevertheless, other clinical signs were exclusive to these subtypes. Recently, multiple molecular diagnostic methods have been developed to identify and characterize these subtypes. Despite these advancements, the molecular pathology of SCAs remains unknown. To further understand the mechanisms involved in neurodegenerative SCAs 2 and 3, patient-derived induced pluripotent stem cell (iPSC)-based modelling is a compelling avenue to pursue. We cover the present state of iPSC-based in-vitro illness modelling of SCA subtypes 2 and 3 below, along with a list of cell lines created, and the relevance of research outcomes to personalized autologous therapy.
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  • 文章类型: Journal Article
    常规尿液培养方法的局限性可以通过使用非培养方法如聚合酶链反应(PCR)和下一代测序(NGS)来避免。然而,在这种情况下,这些方法的有效性仍然存在争议。符合PRISMA的搜索在MEDLINE/PubMed上进行,EMBASE,WebofSciences,和Cochrane数据库,直到2023年3月。所包括的文章将PCR或NGS与常规尿液培养物进行了比较,以检测尿路感染(UTI)。RevMan进行了荟萃分析,Cochrane偏差风险评估工具评估了研究质量。该荟萃分析包括总共10项涉及1,291名个体的选定研究。研究发现,PCR对诊断UTI具有99%的灵敏度和94%的特异性。此外,显示NGS对鉴定UTI具有90%的灵敏度和86%的特异性。PCR检测革兰氏阳性菌的比值比(OR)为0.50(95%置信区间[CI]0.41-0.61),而NGS检测革兰氏阴性菌的OR为0.23[95%CI0.09-0.59]。UTI通常由革兰氏阴性细菌如大肠杆菌和革兰氏阳性细菌如葡萄球菌和链球菌引起。PCR和NGS是可靠的,无培养分子诊断方法,尽管价格昂贵,由于其高灵敏度和特异性,对UTI诊断和预防至关重要。
    The limitations of conventional urine culture methods can be avoided by using culture-independent approaches like polymerase chain reaction (PCR) and next-generation sequencing (NGS). However, the efficacy of these approaches in this setting is still subject to contention. PRISMA-compliant searches were performed on MEDLINE/PubMed, EMBASE, Web of Sciences, and the Cochrane Database until March 2023. The included articles compared PCR or NGS to conventional urine culture for the detection of urinary tract infections (UTIs). RevMan performed meta-analysis, and the Cochrane Risk of Bias Assessment Tool assessed study quality. A total of 10 selected studies that involved 1,291 individuals were included in this meta-analysis. The study found that PCR has a 99% sensitivity and a 94% specificity for diagnosing UTIs. Furthermore, NGS was shown to have a sensitivity of 90% for identifying UTIs and a specificity of 86%. The odds ratio (OR) for PCR to detect Gram-positive bacteria is 0.50 (95% confidence interval [CI] 0.41-0.61), while the OR for NGS to detect Gram-negative bacteria is 0.23 [95% CI 0.09-0.59]. UTIs are typically caused by Gram-negative bacteria like Escherichia coli and Gram-positive bacteria like Staphylococci and Streptococci. PCR and NGS are reliable, culture-free molecular diagnostic methods that, despite being expensive, are essential for UTI diagnosis and prevention due to their high sensitivity and specificity.
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  • 文章类型: Journal Article
    随着人们越来越关注B组链球菌(GBS)感染及其对围产期妊娠的不利影响,包括感染,早产,新生儿败血症,和脑膜炎,迫切需要在所有怀孕阶段推广GBS筛查。这项研究的目的是建立一个独立于设备的,快,敏感,视觉GBS检测方法。利用重组酶聚合酶等温扩增(RPA)的特点,nfo核酸酶裂解碱基类似物(四氢呋喃,THF)现场,以及横向流动色谱条(LFS)的可视化读取的优势,开发了一种GBS检测方法。这种方法集中在由cfb基因编码的Christie-Atkins-Munch-Petersen因子的保守区域,对GBS特异的毒力基因。两个正向引物,两个生物素标记的反向引物,设计了一种异硫氰酸荧光素(FITC)标记和C3间隔区阻断的探针。该研究涉及优化引物对和探针组合,确定最佳反应温度和时间,评估特异性,分析检测限,并对87例围产期孕妇阴道拭子进行了检测。结果表明,GBS-RPA-LFS的视觉检测方法,使用cfb-F1/R2/P1引物探针,可以在39°C至42°C的温度下在15分钟内检测到GBS。此外,该方法仅特异性扩增GBS,不会与乳酸菌等病原体发生交叉反应,卷曲乳杆菌,白色念珠菌,单核细胞增生李斯特菌,小肠结肠炎耶尔森氏菌,肺炎克雷伯菌,阴沟肠杆菌,Freundii柠檬酸杆菌,溶藻弧菌,副溶血性弧菌,鼠伤寒沙门氏菌,金黄色葡萄球菌,铜绿假单胞菌,或者阴道毛滴虫.它可以检测到每个反应最少100个拷贝。在临床98个孕妇阴道拭子样本中,GBS-RPA-LFS法与TaqMan实时荧光定量法的符合率为95.92%。总之,本研究成功建立了RPA和LFS联合GBS原位检测平台,反应时间短,高灵敏度,高特异性,便携性,和设备独立性,为临床GBS筛查提供了可行的策略。
    With growing concerns about Group B streptococcal (GBS) infections and their adverse effects on perinatal pregnancies, including infection, premature delivery, neonatal septicemia, and meningitis, it is urgent to promote GBS screening at all pregnancy stages. The purpose of this study is to establish a device-independent, fast, sensitive, and visual GBS detection method. Taking advantage of the characteristics of the recombinase polymerase isothermal amplification (RPA), the activity of the nfo nuclease cleavage base analog (tetrahydrofuran, THF) site, and the advantages of visual reading of the lateral flow chromatography strip (LFS), a GBS detection method was developed. This method focused on the conservative region of the Christie-Atkins-Munch-Petersen factor encoded by the cfb gene, a virulence gene specific to GBS. Two forward primers, two biotin-labeled reverse primers, and one fluorescein isothiocyanate (FITC)-labeled and C3spacer-blocked probe were designed. The study involved optimizing the primer pair and probe combination, determining the optimal reaction temperature and time, evaluating specificity, analyzing detection limits, and testing the method on 87 vaginal swabs from perinatal pregnant women. The results showed that the visual detection method of GBS-RPA-LFS, using the cfb-F1/R2/P1 primer probe, could detect GBS within 15 min at the temperature ranging from 39°C to 42°C. Furthermore, the method specifically amplified only GBS, without cross-reacting with pathogens like Lactobacillus iners, Lactobacillus crispatus, Candida albicans, Listeria monocytogenes, Yersinia enterocolitica, Klebsiella Pneumoniae, Enterobacter cloacae, Citrobacter freundii, Vibrio alginolyticus, Vibrio parahaemolyticus, Salmonella typhimurium, Staphylococcus aureus, Pseudomonas aeruginosa, or Trichomonas vaginalis. It could detect a minimum of 100 copies per reaction. In clinical 98 samples of vaginal swabs from pregnant women, the agreement rate between the GBS-RPA-LFS method and TaqMan real-time fluorescence quantification method was 95.92%. In conclusion, this study successfully established a combined RPA and LFS GBS in situ detection platform, with short reaction time, high sensitivity, high specificity, portability, and device independence, providing a feasible strategy for clinical GBS screening.
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  • 文章类型: English Abstract
    Molecular analysis of disseminated tumour cells (DTC) may aid in predicting the course of the disease and response to therapies in individual patients. It has been shown in bladder cancer and many other cancer types that the presence of disseminated tumour cells or occult micrometastases in bone marrow or lymph nodes is associated with shorter survival. This type of analysis is particularly important for patients who have been declared disease-free after postsurgery histopathological and clinical imaging analysis. However, comprehensive molecular analysis of disseminated tumour cells is challenging due to the low amount of material and great heterogeneity of the disease. Therefore, currently the routine molecular analysis of these cells is hardly possible in daily clinical practice. Nevertheless, we see daily advances in clinical utility of analysis of cellular or cell-free liquid biopsy analytes taken before, during or after surgery. These advances will enable an integration of translational research workflows into clinical decision-making.
    UNASSIGNED: Disseminierte Tumorzellen (DTC) und deren molekulare Analyse können prognostische Aussagen über den Verlauf einer Tumorerkrankung und dessen Therapieansprechen preisgeben. Bei Urothelkarzinom und vielen anderen Tumorentitäten konnte bereits gezeigt werden, dass ein Vorliegen von disseminierten Tumorzellen oder okkulten Mikrometastasen im Knochenmark (KM) oder in Lymphknoten (LK) mit einem schlechteren Gesamtüberleben vergesellschaftet ist. Vor allem bei Patienten, welche nach histopathologischer und radiologischer Diagnostik als „tumorfrei“ eingestuft werden, spielen diese Erkenntnisse eine wichtige Rolle. Aufgrund der Heterogenität der Tumorerkrankungen und der eingeschränkten Gewebeverfügbarkeit ist eine umfassende molekulare Analyse disseminierter Tumorzellen eine große Herausforderung für die Wissenschaft. Eine routinemäßige Entnahme inklusive Analyse dieser Zellen ist im klinischen Alltag nur schwer möglich. Dennoch haben Analysen von zellulären und zellfreien Flüssigbiopsien (vor, während und nach durchgeführten Eingriffen) einen zunehmenden Stellenwert in der klinischen Praxis. Diese Fortschritte können in der Zukunft in den translationalen Arbeitsablauf im klinischen Alltag implementiert werden.
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  • 文章类型: Journal Article
    BACKGROUND: The brown planthopper, Nilaparvata lugens (Stål), is one of the most notorious pests of rice throughout Asia. The brown planthopper has developed high resistance to imidacloprid, a member of neonicotinoid insecticides. Several genes and mutations conferring imidacloprid resistance in N. lugens, especially in eastern and southeastern Asia populations, have been reported. Thus, the key mechanisms of imidacloprid resistance need to be examined.
    RESULTS: RNA-seq analyses revealed that only one cytochrome P450 monooxygenase gene, CYP6ER1, was commonly upregulated in the five resistant strains tested. Sequences of CYP6ER1, which were highly expressed in the imidacloprid-resistant strains, contained a three-nucleotide deletion in the coding region, and amino acid substitutions and deletion, compared to that in an imidacloprid-susceptible strain. RNAi-mediated gene knockdown of CYP6ER1 increased imidacloprid susceptibility in a resistant strain. Further, we established two simple and convenient PCR-based molecular diagnostic methods to detect the CYP6ER1 locus with the three-nucleotide deletion. Using these methods, the resistance of F2 progenies derived from the crosses of F1 siblings from susceptible and resistant parents was analyzed, showing that the imidacloprid resistance had a relationship to the CYP6ER1 locus with the three-nucleotide deletion.
    CONCLUSIONS: The overexpression of a variant CYP6ER1 with amino acid substitutions and deletion was involved in imidacloprid resistance in N. lugens. Based on these findings, molecular diagnostic methods have been developed and are promising tools for monitoring imidacloprid resistance in paddy fields. © 2020 Society of Chemical Industry.
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  • 文章类型: Evaluation Study
    Genotypic methods have considerably improved the diagnosis of multidrug-resistant (MDR) tuberculosis. One of these tests is Anyplex II MTB/MDR/XDR (Anyplex). Our aim was to evaluate the diagnostic performance of this multiplex PCR.
    We conducted our study on 47 MDR tuberculosis and 14 pan-susceptible strains. We evaluated the ability of Anyplex to detect resistance mutations in rpoB (rifampin [RIF]), katG and inhA (isoniazid [INH]), gyrA (fluoroquinolones [FLQ]), and rrs and eis (aminoglycosides [AMG]). We used the agar proportion method as gold standard. We also studied concordance with GenoType MTBDRplus (first line drugs) and MTBDRsl (second line drugs). DNA sequencing was applied to clarify discrepancies.
    All pan-susceptible strains were susceptible by Anyplex. Sensitivity and specificity of Anyplex for detection of resistance mutations were 97.9% and 100%, respectively, for RIF, 91.5% and 100% for INH, 80% and 100% for FLQ, and 50% and 99.7% for AMG. Concordance with GenoType was perfect for RIF, INH, and FLQ (kappa score, k=1.0) and moderate for AMG (k=0.48). Sensitivity and specificity for detection of MDR tuberculosis were 89.4% and 100%, respectively. DNA sequencing of the phenotypically resistant strains considered as susceptible by Anyplex, confirmed no mutations in the corresponding genes.
    Anyplex is a reliable assay for the detection of MDR tuberculosis and shows excellent concordance with GenoType. Anyplex reduces the time to diagnosis of MDR tuberculosis strains, as it is recommended by current guidelines on control of tuberculosis.
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  • 文章类型: Journal Article
    人类诺如病毒是一组折磨所有年龄组的人的病毒因子。这些病毒现在被认为是全世界非细菌性急性胃肠炎和食源性病毒疾病的最常见病原体。然而,在过去的几十年中,它们被认为在急性胃肠炎的疾病负担中起着无关紧要的作用,直到最近出现了新的和更敏感的分子诊断方法.分子诊断方法的可用性和应用导致临床对诺如病毒的检测得到加强,食物和环境样本,显着增加诺如病毒作为流行性和散发性急性胃肠炎的病原体的认识。本文旨在总结最近为开发检测和表征人类诺如病毒的分子方法所做的努力。
    Human noroviruses are a group of viral agents that afflict people of all age groups. The viruses are now recognized as the most common causative agent of nonbacterial acute gastroenteritis and foodborne viral illness worldwide. However, they have been considered to play insignificant roles in the disease burden of acute gastroenteritis for the past decades until the recent advent of new and more sensitive molecular diagnostic methods. The availability and application of the molecular diagnostic methods have led to enhanced detection of noroviruses in clinical, food and environmental samples, significantly increasing the recognition of noroviruses as an etiologic agent of epidemic and sporadic acute gastroenteritis. This article aims to summarize recent efforts made for the development of molecular methods for the detection and characterization of human noroviruses.
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