Utility of Tissue Similarity Maps Based on Relative Cerebral Blood Volume for Grading Gliomas as Validated by Histological Results

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生命早期抗生素使用与儿童哮喘:因果关系还是混杂效应?

儿童哮喘的发病率逐年上升.基于卫生假说,抗生素使用可能减少了微生物暴露,从而增加了过敏性疾病发生的风险.近十年来,就早期抗生素暴露与儿童哮喘的关系进行的大量的流行病学调查的结果并不一致.大多数回顾性研究发现正相关联系,但前瞻性研究未发现联系或联系强度较弱.逆向因果和指示混淆可部分解释两者的关系,但也难以否定因果关系的存在.     

Population Genetics Identifies Challenges in Analyzing Rare Variants

Geneticists have, for years, understood the nature of genome‐wide association studies using common genomic variants. Recently, however, focus has shifted to the analysis of rare variants. This presents potential problems for researchers, as rare variants do not always behave in the same way common variants do, sometimes rendering decades of solid intuition moot. In this paper, we present examples of the differences between common and rare variants. We show why one must be significantly more careful about the origin of rare variants, and how failing to do so can lead to highly inflated type I error. We then explain how to best avoid such concerns with careful understanding and study design. Additionally, we demonstrate that a seemingly low error rate in next‐generation sequencing can dramatically impact the false‐positive rate for rare variants. This is due to the fact that rare variants are, by definition, seen infrequently, making it hard to distinguish between errors and real variants. Compounding this problem is the fact that the proportion of errors is likely to get worse, not better, with increasing sample size. One cannot simply scale their way up in order to solve this problem. Understanding these potential pitfalls is a key step in successfully identifying true associations between rare variants and diseases.     

In Vivo Kinematics of Functional Ankle Instability Patients and Lateral Ankle Sprain Copers During Stair Descent

Patients with mechanic ankle instability experience increased tibiotalar and subtalar joint laxity. However, in vivo joint kinematics in functional ankle instability (FAI) patients and lateral ankle sprain (LAS) copers, especially during dynamic activities, are poorly understood. Ten FAI patients, 10 LAS copers, and 10 healthy controls were included in this study. A dual fluoroscopic imaging system was used to analyze the tibiotalar and subtalar joint kinematics during stair descent. Five key poses of stair descent were analyzed. Kinematic data from six degrees of freedom were calculated utilizing a solid modeling software. The range of motion and joint positions in each degree of freedom were compared among the three groups. The tibiotalar joints of FAI patients and LAS copers were significantly more inverted than those of healthy controls during the foot strike (p = 0.016, = 0.264). The subtalar joints of FAI patients were significantly more anteriorly translated (pose 2, p = 0.003, = 0.352; pose 3, p < 0.001, = 0.454; pose 4, p = 0.004, = 0.334), inverted (pose 4, p = 0.027, = 0.234; pose 5,p = 0.034, = 0.221), and externally rotated (pose 4, p = 0.037, = 0.217; pose 5; p = 0.004, = 0.331) than those of healthy controls during the mid‐stance and the heel off. The FAI patients showed excessive tibiotalar inversion and subtalar joint hypermobility during stair descent. Meanwhile, the LAS copers maintained subtalar joint stability, and only showed excessive tibiotalar inversion in foot strike. These data provide insight into the mechanisms behind the development of FAI after initial LAS. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1860–1867, 2019     

Antidiabetic activity of Helicteres angustifolia root

Context The root of Helicteres angustifolia L. (Sterculiaceae) has been used as folk herbal drug to treat cancer, bacterial infections, inflammatory, and flu in China. However, there is no report on its antidiabetic activity.

Objective This study evaluates the antidiabetic activity of ethanol extract from H. angustifolia root.

Materials and methods The promoting effect of H. angustifolia root ethanol extract (25, 50, and 100 μg/mL) on glucose uptake was evaluated using HepG2 cell, differentiated C2C12 myotubes, and differentiated 3T3-L1 adipocytes. The antidiabetic activity of the extract was assessed in vivo using STZ-induced diabetic rats by orally administration of the extract (200 and 400?mg/kg b.w.) once per day for 28 d. Blood glucose, TG, TC, TP, HDL-C, UA, BUN, AST, ALT, insulin, and HOMA-IR were analyzed.

Results The results showed that the extract increased glucose uptake in C2C12 myotubes and 3T3-L1 adipocytes with an IC₅₀ value of 79.95 and 135.96 μg/mL, respectively. And about 12%, 19%, and 10% (p < 0.05) in HepG2 cells when compared with the control at the concentration of 25, 50, and 100 μg/mL, respectively. After 28 days’ treatment with the extract, significant reduction was observed in blood glucose, HOMA-IR, TC, TG, UA, BUN, AST, and ALT levels, while the levels of TP and HDL cholesterol increased.

Discussion and conclusion These results suggest that H. angustifolia root ethanol extract possess potent antidiabetic activity, which is the first report on antidiabetic activity of this plant.