ArgD of Mycobacterium tuberculosis is a functional N-acetylornithine aminotransferase with moonlighting function as an effective immune modulator

Mycobacterium tuberculosis (M. tuberculosis) encodes an essential enzyme acetyl ornithine aminotransferase ArgD (Rv1655) of arginine biosynthetic pathway which plays crucial role in M. tuberculosis growth and survival. ArgD catalyzes the reversible conversion of N-acetylornithine and 2 oxoglutarate into glutamate-5-semialdehyde and L-glutamate. It also possesses succinyl diaminopimelate aminotransferase activity and can thus carry out the corresponding step in lysine biosynthesis. These essential roles played by ArgD in amino acid biosynthetic pathways highlight it as an important metabolic chokepoint thus an important drug target. We showed that M. tuberculosis ArgD rescues the growth of ΔargD E. coli grown in minimal media validating its functional importance. Phylogenetic analysis of M. tuberculosis ArgD showed homology with proteins in gram positive bacteria, pathogenic and non-pathogenic mycobacteria suggesting the essentiality of this protein. ArgD is a secretory protein that could be utilized by M. tuberculosis to modulate host innate immunity as its moonlighting function. In-silico analysis predicted it to be a highly antigenic protein. The recombinant ArgD protein when exposed to macrophage cells induced enhanced production of pro-inflammatory cytokines TNF, IL6 and IL12 in a dose dependent manner. ArgD also induced the increased production of innate immune effector molecule NOS2 and NO in macrophages. We also demonstrated ArgD mediated activation of the canonical NFkB pathway. Notably, we also show that ArgD is a specific TLR4 agonist involved in the activation of pro-inflammatory signaling for sustained production of effector cytokines. Intriguingly, ArgD protein treatment activated macrophages to acquire the M1 phenotype through the increased surface expression of MHCII and costimulatory molecules CD80 and CD86. ArgD induced robust B-cell response in immunized mice, validating its antigenicity potential as predicted by the in-silico analysis. These properties of M. tuberculosis ArgD signify its functional plasticity that could be exploited as a possible drug target to combat tuberculosis.     

Functional outcomes and complications after treatment of distal radius fracture in patients sixty years and over: A systematic review and network meta-analysis

AimThis network meta-analysis aims to compare functional outcomes and complications between conservative treatment and surgery for distal radius fractures in patients aged 60 years and over.MethodsWe searched the PubMed, EMBASE, and Web of Science databases for randomized controlled trials (RCTs) assessing the effect of conservative treatment and surgery for distal radius fractures in patients aged 60 years and over. Primary outcomes included grip strength and overall complications. Secondary outcomes included Disabilities of the Arm, Shoulder, and Hand (DASH) scores, Patient-Rated Wrist Evaluation (PRWE) scores, wrist range of motion and forearm rotation, and radiographic assessment. All continuous outcomes were assessed using standardized mean differences (SMDs) with 95% confidence intervals (CIs), and binary outcomes were assessed using odds ratio (OR) with 95% CIs. The surface under the cumulative ranking curve (SUCRA) was used to determine a hierarchy of treatments. Cluster analysis was performed for grouping treatments based on the SUCRA values of primary outcomes.ResultsFourteen RCTs were included to compare conservative treatment, volar lockedplate (VLP), K-wires fixation, and external-fixation. VLP outperformed conservative treatment for 1-year and minimum 2-year grip strength (SMD; 0.28 [0.07 to 0.48] and 0.27 [0.02 to 0.53], respectively). VLP yielded the optimal grip strength at 1-year and minimum 2-year follow-up (SUCRA; 89.8% and 86.7%, respectively). In a subgroup analysis of patients aged 60 to 80 years old, VLP outperformed conservative treatment in DASH and PRWE scores (SMD, 0.33 [0.10, 0.56] and 0.23 [0.01, 0.45], respectively). In addition, VLP had the fewest complications (SUCRA = 84.3%). Cluster analysis suggested that VLP and K-wire fixation were more effective treatment groups.ConclusionEvidence to date demonstrates that VLP provides measurable benefits in grip strength and fewer complications to those 60 years of age and over, and that benefit is not reflected in current practice guidelines. There is a subgroup of patients where K-wire fixation outcomes are similar to those of VLP; defining this subgroup may yield substantial societal benefits.     

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。     

Contributions of the NICHD neonatal research network's generic database to documenting and advancing the outcomes of extremely preterm infants

The Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network (NRN) maintains a database of extremely preterm infants known as the Generic Database (GDB). Begun in 1987, this database now includes more than 91,000 infants, most of whom are extremely preterm (<29 weeks gestation). The GDB has been the backbone of the NRN, providing high quality, prospectively collected data to study the changing epidemiology of extreme prematurity and its outcomes over time. In addition, GDB data have been used to generate hypotheses for prospective studies and to develop new clinical trials by providing information about the numbers and characteristics of available subjects and the expected event rates for conditions and complications to be studied. Since its inception, the GDB has been the basis of more than 200 publications in peer-reviewed journals, many of which have had a significant impact on the field of neonatology.     

刺槐素通过调控TLR4通路对干眼症大鼠的保护作用及其机制研究＊

目的 研究刺槐素对干眼症（DED）大鼠的保护作用及可能的分子机制。方法 60只SD大鼠随机分为空白组（不做处理）；模型组；0.1% SH组；刺槐素0.1%、0.25%、0.5%组。每组10只，除正常组外，每日4次皮下注射12.5 mg/天氢溴酸东莨菪碱（SCOP），共7天。所有的药物均为在眼球表面局部给药，每只眼睛20 μL，每天4次。通过泪液分泌实验检测各组大鼠泪液分泌情况，通过角膜荧光染色检测各组大鼠角膜表面缺损情况，过碘酸雪夫试剂（PAS）染色观察结膜杯状细胞数量，酶联免疫吸附法（ELISA）检测各组大鼠角膜组织中炎症反应和氧化应激相关指标含量。免疫印迹法（Western blot）检测各组大鼠角膜组织中Toll样受体4（TLR4）通路相关蛋白TLR4、髓样分化因子88（MyD88）、核因子κB p65（NF-κB p65）、Pyrin域蛋白3（NLRP3）蛋白表达。结果 与正常组相比，模型组大鼠泪液分泌量、结膜杯状细胞数量明显减少，角膜荧光素染色评分显著升高，但角膜新血管生成评分减少，同时角膜组织中白细胞介素1β（IL-1β）、肿瘤坏死因子α（TNF-α）、IL-10、丙二醛（MDA）水平上调，而超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-Px）含量则下调，TLR4、MyD88、NLRP3、p-NF-κB p65蛋白相对表达量均升高（P<0.05）；与模型组相比，经刺槐素0.25%、0.5%组治疗后，大鼠泪液分泌量、结膜杯状细胞数量明显增加，角膜荧光素染色评分显著降低，角膜新血管生成评分显著增加，同时角膜组织中IL-1β、TNF-α、IL-10、MDA水平下调，而SOD和GSH-Px含量则上调（P<0.05），尤其是刺槐素0.5%组上述指标变化更明显，而且角膜组织中TLR4、MyD88、NLRP3、p-NF-κB p65蛋白相对表达量较模型组显著降低（P<0.05）。结论 刺槐素对干眼症大鼠具有保护作用，其保护机制与抑制干眼症大鼠的氧化应激反应、炎症反应和TLR4/MyD88/NLRP3通路活性有关。     

Methodological advances in the design of peptide-based vaccines

The tremendous advances in genomics, recombinant DNA technology, bioengineering and nanotechnology, in conjunction with the development of high-end computations, have been instrumental in the process of rational design of peptide-based vaccines. The use of peptide vaccines was limited owing to their inherent instability when systemically administered; however, advanced formulation techniques have been developed for their systemic delivery, thereby overcoming their degradation, clearance, cellular uptake and off-target effects. With the rise of sophisticated immunological predictors and experimental techniques, several methodological advances have occurred in this field. This review examines contemporary methods to identify and optimize epitopes, engineer their immunogenic properties and develop their safe and efficient delivery into the host.