DNA损伤在衰老相关疾病中的研究进展

DNA损伤是衰老相关疾病领域的研究热点, 可引起细胞周期停滞、凋亡, 加快个体衰老速度、增加衰老相关疾病的患病风险。本文将从细胞衰老和个体衰老两个层面阐述其与衰老之间的研究进展, 并综述其与衰老常见相关疾病(肿瘤、心血管疾病、阿尔茨海默病)及早衰综合征的关系, 为抗衰老研究和临床干预衰老相关疾病提供理论依据。     

Interpretation,pitfalls of biomarkers in diagnosis of invasive fungal diseases

BackgroundInvasive Fungal Diseases (IFD), account for high morbidity and mortality in immunocompromised and seriously ill patients worldwide. Early, faster and accurate diagnosis with timely and appropriate patient management is critical for improved patient outcome and antifungal stewardship. Clinical/radiological presentations in IFD are non-specific and microscopy/culture based tests have low sensitivity and long turnaround time. Biomarkers have clinical utility for diagnosing IFD but their interpretation is not straight forward.ObjectivesThis review discusses the salient characteristics, clinical usefulness and limitations of common biomarkers such as Galactomannan (GM), 1–3, β D glucan (βDG), mannan, anti-mannan antibody (Mn/antiMn), Cryptococcal antigen test (CrAg), Nucleic Acid Amplification (NAA) tests and next generation sequencing for diagnosing IFD.ContentsFungal biomarkers are useful adjuncts as screening and diagnostic tools for IFD and are much more suited for ‘ruling out’ rather than ‘ruling in’ disease. GM, NAA tests are promising biomarkers for screening of invasive Aspergillosis in high risk asymptomatic patients who are not on antifungal therapy and for diagnosis of breakthrough infections in symptomatic patients. 1–3, β D glucan has limitations both as a ‘rule in’ and ‘rule out’ test and is useful in only specific clinical settings. Two consecutive positive 1-3-βDG tests or combined positivity with GM increases its specificity. Mn/antiMn, T2Candida nano diagnostic panel are promising candidates for diagnosing invasive candidiasis. Combining two or more biomarkers improves the sensitivity for prompt initiation of antifungal therapy and the negative predictive value for suspension of empirical treatment.Serum CrAg test is a good ‘rule in’ rather than a ‘rule out’ test in immunocompetent patients but has good diagnostic accuracy in immunocompromised patients. Detection of single nucleotide polymorphisms by next generation sequencing is useful for fungal characterization and identification of host determinants responsible for increased susceptibility to fungal infections but is still in experimental stages.     

Recurrent aseptic liver abscesses in a patient with Crohn’s disease: True infection or a Crohn’s flare?

A liver abscess is identified as a rare extraintestinal manifestation of Crohn’s disease, with an incidence of approximately 150 in 100,000 patients with this condition. In many of these patients, infectious causes are identified, and the patient’s condition is often noted to improve with antibiotics. An aseptic abscess (AA) is an increasingly recognized entity, especially in patients with inflammatory bowel disease, where repetitive evaluations to identify the infectious cause are futile. The average age of diagnosis for an AA is 29 years. The most common site is the spleen, followed by the lymph nodes and then the liver. In this study, we present a unique case of extensive aseptic liver abscesses extending into the pleural cavity in a young patient with Crohn’s disease.     

Left ventricular noncompaction associated with a pathogenic mutation in the MYH7 gene: Known mutation,different phenotype

Left ventricular noncompaction (LVNC) is a genetically heterogeneous cardiomyopathy, with familial and sporadic forms, but genetic testing only identifies a pathogenic mutation in a minority of cases. The main complications are heart failure, embolism and dysrhythmias. Herein we report a familial case of LVNC associated with a mutation in the MYH7 gene and review the literature regarding controversies in LVNC. A 50-year-old woman was referred to the cardiology clinic for palpitations. She underwent echocardiography and cardiac magnetic resonance imaging that revealed mild left ventricular systolic dysfunction and LVNC criteria. She had several episodes of non-sustained ventricular tachycardia and received an implantable cardioverter-defibrillator (ICD). Genetic testing revealed the c.1003G>C (p.Ala335Pro) mutation in the MYH7 gene. Familial screening showed clear genotype-phenotype cosegregation, which provided strong evidence for the pathogenic role of this mutation. To the best of our knowledge, this is the first report of LVNC associated with the p.Ala335Pro mutation in the MYH7 gene. This mutation has been described in hypertrophic cardiomyopathy, suggesting that the same pathogenic sarcomere mutation may be associated with different cardiomyopathies. This case also highlights the current difficulties regarding decisions on ICD implantation for primary prevention of sudden cardiac death in LVNC.     

Orphan drug development: The impact of regulatory and reimbursement frameworks

The enactment of orphan drug-specific legislation pioneered by the USA was subsequently followed by many regions, including the European Union (EU), Australia, Japan, and Taiwan. Here, we discuss the associated regulations established and their impacts in the aforementioned regions, which are among the first with frameworks specific for orphan drugs. Varied scopes of rare diseases or orphan drugs, diverse incentives, and heterogeneous types of reimbursement systems imply the prioritization of the agencies concerned. The numbers of designated and approved drugs reflect the impact of the regulatory and reimbursement frameworks. A comparison of the frameworks and their impact in the respective regions could provide valuable information for developing and improving related frameworks for countries worldwide.     

Paradox of complex diversity: Challenges in the diagnosis and management of bacterial keratitis

Bacterial keratitis continues to be one of the leading causes of corneal blindness in the developed as well as the developing world, despite swift progress since the dawn of the “anti-biotic era”. Although, we have expeditiously developed our understanding about the different causative organisms and associated pathology leading to keratitis, extensive gaps in knowledge continue to dampen the efforts required for early and accurate diagnosis, and management in these patients, resulting in poor clinical outcomes. The ability of the causative bacteria to subdue the therapeutic challenge stems from their large genome encoding complex regulatory networks, variety of unique virulence factors, and rapid secretion of tissue damaging proteases and toxins.In this review article, we provide an overview of the established diagnostic techniques and therapeutics for keratitis caused by various bacteria. We extensively report the recent in-roads through novel tools for accurately diagnosing mono- and poly-bacterial corneal infections. Furthermore, we outline the recent progress by our groups and others in understanding the sub-cellular genomic changes that lead to antibiotic resistance in these organisms. Finally, we discuss in detail, the novel therapies and drug delivery systems in development for the efficacious management of bacterial keratitis.     

基于SSR标记与化学成分构建十堰地区天师栗核心种质库＊

目的 利用筛选出十堰的天师栗中高多态性SSR位点评价天师栗种质资源的遗传多样性，结合有效药用成分含量，构建十堰地区天师栗核心种质库。方法 收集十堰地区114份天师栗种质资源，以七叶树基因组为参考，采用荧光毛细管电泳筛选出高多态性SSR位点，对天师栗种质资源进行遗传多样性分析。利用HPLC测定不同种质干燥娑罗子中七叶皂苷的含量。采用最小距离逐步聚类取样策略（LDSS），根据遗传多样性保留程度初步筛选出核心种质，并对该核心种质与原始种质的遗传多样性参数进行T检验，选择与原种质差异不显著的核心种质为最佳核心种质。结果 筛选出13对高多态性SSR分子标记，遗传多样性评价结果表明十堰地区天师栗种质资源遗传多样性较高，遗传分化较小，存在着较大的基因流，114份种质资源未分为不同的亚群，周家坝和辽叶居群间具有较近的遗传亲缘关系，且周家坝居群娑罗子中的七叶皂苷A及七叶皂苷B含量普遍较高。最终筛选出的核心种质共23份，占总种质资源的20.17%，其中周家坝12份样本、辽叶6份样本、普龄5份样本。结论 将SSR分子标记与主要有效药用成分结合，采用LDSS取样策略构建十堰地区天师栗种质资源核心种质库的方法具有可行性，能够有效的保存与管理天师栗种质资源，也为当地天师栗品种改良、新品种选育研究等提供了研究基础。     

The views of people with a lived experience of deafness and the general public regarding genetic testing for deafness in the reproductive setting: A systematic review

PurposeGenes associated with nonsyndromic hearing loss are commonly included in reproductive carrier screening panels, which are now routinely offered in preconception and prenatal care in many countries. However, there is debate whether hearing loss should be considered a medical condition appropriate for screening. This systematic review assessed research on opinions of those with a lived experience of deafness and the general public regarding genetic testing for deafness in the reproductive setting.MethodsSearch of 5 online databases yielded 423 articles, 20 of which met inclusion criteria. We assessed the quality of each study, extracted data, and performed thematic analysis on qualitative studies.ResultsMost studies indicated interest in the use of prenatal diagnosis for deafness. However, there were mixed views, and sometimes strongly held views, expressed regarding the reproductive options that should be available to those with an increased chance of having a child with deafness. Studies were small, from a limited number of countries, and most were too old to include views regarding preimplantation genetic testing.ConclusionThere is a broad range of views regarding the use of reproductive options for deafness. Further research is essential to explore the benefits and harms of including nonsyndromic hearing loss genes in carrier screening.