【特刊综述】雄激素对骨骼肌的作用：对乏力的发展和治疗的意义

雄激素对骨骼肌合成有明显影响,随着年龄增大,雄激素的下降常伴随肌量和肌力的下降。这种肌量和肌功能的下降,被称为少肌症或肌体老化,是老年人体质弱化（男性化减退）进展的关键事项。也是导致快速机能衰退及其不良后果的关键。雄激素水平下降对老年男性体质弱化（男性化减退）的潜在影响和对躯体功能的促进治疗作用无疑已经引起了相当的关注。本综述概述了近期关于肌肉老化、少肌症、老年体质弱化的概念、定义,并评估了关于雄激素和老年体质弱化的研究进展。近期源于观测性和介入性研究的证据强烈支持雄激素对老年男性肌量的作用,但雄激素对肌力和特有的躯体功能的效用并不明确。研究显示,雄激素治疗在老年男性中通常有良好的耐受性,而近期的研究则关注于雄激素的高剂量治疗和对于心血管风险较高人群的治疗。雄激素受体调节剂（SARMs）的初期试验研究显示传统雄激素治疗对于老年患者在肌量和肌功能方面有相同的效用。将来的重要研究方向包括利用这类雄激素治疗并结合适用于不同老年患者群体促进躯体功能的运动训练,同时将更多地关注近期关于激素水平、身体成分及躯体功能间关系的观测性（回顾性）研究。     

首发脑卒中患者康复锻炼行为执行意向及影响因素分析

目的 了解首发脑卒中患者康复锻炼行为执行意向水平及其影响因素,为脑卒中患者康复锻炼行为的干预提供参考.方法 采用一般资料调查表、中文版脑卒中康复自我效能量表、社会支持量表、自行设计的脑卒中患者康复锻炼行为执行意向问卷对177例首发脑卒中患者进行调查.结果 首发脑卒中患者康复锻炼行为执行意向得分62.69±17.27.回...     

DSA引导下血管腔内成形术治疗下肢动脉硬化闭塞症的临床研究

目的:探讨DSA引导下血管腔内成形术(TA)治疗下肢动脉硬化闭塞症(ASO-LE)的临床效果.方法:2017年3月至2019年4月,手术治疗的ASO-LE患者93例,依据治疗方式的不同分为A组(行TA,=49)和B组[行下肢动脉旁路移植术(LEABG),=44],两组患者均在数字减影血管造影(DSA)引导下进行.对比两...     

Novel Strategy to Engineer Trachea Cartilage Graft With Marrow Mesenchymal Stem Cell Macroaggregate and Hydrolyzable Scaffold

Limited donor sites of cartilage and dedifferentiation of chondrocytes during expansion, low tissue reconstruction efficiency, and uncontrollable immune reactions to foreign materials are the main obstacles to overcome before cartilage tissue engineering can be widely used in the clinic. In the current study, we developed a novel strategy to fabricate tissue‐engineered trachea cartilage grafts using marrow mesenchymal stem cell (MSC) macroaggregates and hydrolyzable scaffold of polylactic acid–polyglycolic acid copolymer (PLGA). Rabbit MSCs were continuously cultured to prepare macroaggregates in sheet form. The macroaggregates were studied for their potential for chondrogenesis. The macroaggregates were wrapped against the PLGA scaffold to make a tubular composite. The composites were incubated in spinner flasks for 4 weeks to fabricate trachea cartilage grafts. Histological observation and polymerase chain reaction array showed that MSC macroaggregates could obtain the optimal chondrogenic capacity under the induction of transforming growth factor‐β. Engineered trachea cartilage consisted of evenly spaced lacunae embedded in a matrix rich in proteoglycans. PLGA scaffold degraded totally during in vitro incubation and the engineered cartilage graft was composed of autologous tissue. Based on this novel, MSC macroaggregate and hydrolyzable scaffold composite strategy, ready‐to‐implant autologous trachea cartilage grafts could be successfully fabricated. The strategy also had the advantages of high efficiency in cell seeding and tissue regeneration, and could possibly be used in future in vivo experiments.     

Correction to: Gyral-sulcal contrast in intrinsic functional brain networks across task performances

Brain Imaging and Behavior - A Correction to this paper has been published: https://doi.org/10.1007/s11682-020-00426-z     

Predicting RNA secondary structure based on the class information and Hopfield network

One of the models for RNA secondary structure prediction is to view it as maximum independent set problem, which can be approximately solved by Hopfield network. However, when predicting native molecules, the model is not always accurate and the heuristic method of Hopfield network is not always stable. It is because that the class information is lost and the accuracy is not determined by the number of base pairs only. Secondary structures of non-coding RNAs are believed conservative on the same class. However, software and web servers nowadays for RNA secondary structure prediction do not consider the class information. In this paper, we involve class information in the initialization of Hopfield network. When the initialization is improved, the promising experimental result shows the efficacy and superiority of our proposed methods.     

Laminar-flow immediate-overlay hepatocyte sandwich perfusion system for drug hepatotoxicity testing

Drug hepatotoxicity testing requires in vitro hepatocyte culture to maintain the long-term and stable liver specific functions. We developed a drug testing platform based on laminar-flow immediate-overlay hepatocyte sandwich perfusion culture. The immediate-overlay sandwich (collagen-coated porous polymeric membrane as top overlay) protects the cells and integrity of the top collagen matrix from the impact of flow. A bioreactor was designed that allowed proper control of shear stress and mass transfer. The culture parameters such as the optimal perfusion initiation time and flow rate were systematically and mechanistically determined. The optimized system could re-establish hepatocyte polarity to support biliary excretion and to maintain other liver specific functions, such as the biotransformation enzyme activities, for two weeks that extended the usable in vitro hepatocyte-based drug testing window. When the perfusion cultured hepatocytes from days 7 or 14 were used for drug testing, the APAP-induced hepatotoxicity measurements were more sensitive and consistent over time than the static culture control, enabling further exploitations in large-scale drug testing applications.     

Use of E mu-PIM-1 transgenic mice short-term in vivo carcinogenicity testing: lymphoma induction by benzo[a]pyrene, but not by TPA

E mu-pim-1 transgenic mice are predisposed to develop lymphomas. Due to their low spontaneous tumour incidence and their increased sensitivity towards the lymphomagen ethylnitrosourea these mice may present an interesting model for short-term carcinogenicity testing. Here, we report on the further exploration of this transgenic mouse model with two additional carcinogens known to have, among others, the lymphohaematopoietic system as target, i.e. benzo[a]pyrene (B[a]P) and 12-O-tetradecanoylphorbol-13-acetate (TPA). B[a]P, given three times a week (by gavage) for 13 weeks at 4.3, 13 or 39 mg/kg body weight, resulted in a dose-related increase in lymphomas up to a 90% incidence in E(mu)-pim-1 mice during the observation period of 40 weeks. B[a]P also induced tumours of the forestomach within this observation period, though at a lower incidence and apparently equally effective in wildtype and transgenic mice. TPA, on the other hand, was unable to induce lymphomas (or tumours in any other organ) in either transgenic or wildtype animals within the observation period of 44 weeks, when applied dermally at the maximum tolerated dose of 3 microg/mouse, twice a week for 35 weeks. Molecular analysis showed that B[a]P-induced lymphomas in transgenic mice were of T-cell origin, 80% of which had elevated levels of c-myc expression. None of the lymphomas had increased N-myc expression and mutation analysis of the ras-gene family revealed a K-ras mutation in only one out of eight tumours investigated. Also, none of the lymphomas showed aberrant expression of p53 as determined by immunohistochemistry. It is concluded that the E mu-pim-1 mouse model will not be very suitable for short-term carcinogenicity testing in general: only genotoxic chemicals that have the lymphohaematopoietic system as target for carcinogenesis in wild- type mice, appear to be efficiently identified.