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.     

基于人工智能的骨龄辅助评价系统对四川地区完全性生长激素缺乏症患儿骨龄研究

目的探讨采用基于"人工智能(AI)的骨龄辅助评价系统(上海初云医疗科技有限公司与四川大学华西第二医院合作开发)"(以下简称为AI系统)对完全性生长激素缺乏症(CGHD)患儿诊断及骨龄评价准确性。 方法选择2014年7月至2019年11月，于四川大学华西第二医院确诊的66例来自四川地区CGHD患儿为研究对象，纳入研究组。选择同期于病例收集医院儿童保健科进行骨龄测定的67例来自四川地区身高达标儿童作为对照，纳入对照组。对每例受试儿进行左手腕关节正位X射线摄片骨龄测定，由2位医师采用《TW₂骨龄评分法中国未成年人南方标准》(以下简称为TW₂CHN)》与《TW₃骨龄评分法标准》(以下简称为TW₃)，盲法评价受试儿TW₂CHN-桡、尺、掌指骨(RUS)与TW₂CHN-腕骨(carpal)、TW₂CHN-20、TW₃-RUS及TW₃-carpal骨龄(以下简称为5种传统骨龄)，以及以同性别、年龄身高达标儿童5种传统骨龄为标准，计算受试儿5种传统骨龄百分位数。同时，采用AI系统分别对每例受试儿采取TW₂CHN与TW₃法，评价其AI-TW₂CHN-RUS、AI-TW₂CHN-carpal、AI-TW₂CHN-20、AI-TW₃-RUS及AI-TW₃-carpal骨龄(以下简称为5种AI骨龄)及其相应百分位数。以上述5种传统骨龄＋5种AI骨龄(以下简称为10种骨龄)相应的P₅₀、P₂₅、P₁₀、P₃值(统称为P_n值)作为诊断CGHD患儿临界值，分别计算其诊断CGHD患儿的敏感度、特异度、约登(Youden)指数、准确率、阳性似然比、阴性似然比、阳性预测值、阴性预测值。采用Kappa值评价2组受试儿5种传统骨龄百分位数与对应的5种AI骨龄百分位数评价结果的一致性，以及2位医师对2组受试儿TW₂CHN-RUS骨龄百分位数评价结果一致性。绘制上述10种骨龄百分位数诊断CGHD患儿的受试者工作特征(ROC)曲线，并计算曲线下面积(AUC)。采用配对t检验，对2组受试儿TW₂CHN骨龄与TW₃骨龄进行比较。本研究遵循的程序符合2013年新修订的《世界医学协会赫尔辛基宣言》要求。2组受试儿年龄、性别构成比等一般临床资料比较，差异均无统计学意义(P>0.05)。 结果①采用10种骨龄的P_n值分别作为诊断CGHD临界值，对133例受试儿CGHD诊断结果显示，除了TW₃-RUS骨龄中，以骨龄≤P₁₀作为诊断CGHD患儿临界值时的诊断准确率最高(85.0%)，TW₂CHN-RUS、TW₂CHN-carpal、TW₂CHN-20、TW₃-carpal、AI-TW₂CHN-RUS、AI-TW₂CHN-carpal、AI-TW₂CHN-20、AI-TW₃-carpal、AI-TW₃-RUS骨龄中，均为以骨龄≤P₂₅作为临界值时，对CGHD的诊断准确率最高，分别为81.9%、75.2%、88.0%、78.2%、75.2%、73.6%、81.2%、72.9%、78.9%。②一致性检验结果显示，2组受试儿TW₂CHN-RUS与AI-TW₂CHN-RUS、TW₂CHN-carpal与AI-TW₂CHN-carpal、TW₂CHN-20与AI-TW₂CHN-20、TW₃-RUS与AI-TW₃-RUS、TW₃-carpal与AI-TW₃-carpal骨龄百分位数评价结果均为中等一致性，Kappa值分别为0.445、0.578、0.570、0.446、0.430(均为P<0.001)。③对2位医师对2组受试儿TW₂CHN-RUS骨龄百分位数评价结果进行一致性检验显示，其Kappa值为0.790(P<0.001)，一致性较高。④绘制10种骨龄百分位数评价结果诊断CGHD的ROC曲线分析结果显示，TW₂CHN-RUS、TW₂CHN-carpal、TW₂CHN-20、TW₃-carpal、TW₃-RUS、AI-TW₂CHN-RUS、AI-TW₂CHN-carpal、AI-TW₂CHN-20、AI-TW₃-carpal、AI-TW₃-RUS骨龄百分位数诊断CGHD患儿的AUC分别为0.932、0.859、0.915、0.895、0.844、0.823、0.805、0.866、0.860、0.764(均为P<0.001)。⑤133例受试儿的TW₃-RUS、TW₃-carpal、AI-TW₃-RUS、AI-TW₃-carpal骨龄，均分别显著低于TW₂CHN-RUS、TW₂CHN-carpal、AI-TW₂CHN-RUS、AI-TW₂CHN-carpal骨龄，并且差异均有统计学意义(t＝21.746、25.287、16.498、9.290，P<0.001)。 结论TW₂CHN法、TW₃法对CGHD患儿骨龄评价及诊断均有临床价值，TW₂CHN-RUS骨龄对于CGDH患儿诊断效能高。四川地区儿童TW₃骨龄较TW₂CHN骨龄低，TW₃法可能不完全适用于四川地区儿童骨龄评价。AI系统对于四川地区CGHD患儿骨龄评价结果与传统骨龄评价结果具有中等一致性，可为临床医师评价受试儿骨龄提供帮助。     

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.     

胶质淋巴系统——脑部疾病机制研究新方向

胶质淋巴系统是一个主要由星形胶质细胞水通道蛋白4介导的依靠动脉、静脉周围血管间隙的脑脊液-脑组织液交换流动的系统，是阿尔茨海默病、脑卒中、帕金森病、失眠、抑郁症等脑病的共同特征，是一条新的脑代谢途径，可以清除包括β-淀粉样蛋白、乳酸在内的代谢产物。本文综合分析了全球有关胶质淋巴系统在脑部疾病的研究，得出：胶质淋巴系统可能为神经退行性疾病等发病机制和诊治策略研究带来新视角；胶质淋巴系统有望为一些脑部疾病诊断提供新的有效证据；胶质淋巴系统可能是脑部疾病治疗给药方式的新途径。