高糖对体外培养Schwann细胞生长及细胞外信号调节激酶1／2磷酸化的影响

目的:探讨高糖对体外培养Schwann细胞生长及细胞外信号调节激酶(ERK)磷酸化的影响.方法:按照培养液中葡萄糖浓度的小同,分为对照组与高糖组.用MTT法检测Schwann细胞生长情况;用ELISA法检测对照组与高糖组ERK1/2磷酸化的程度,以及加入神经源性一氧化氮合成酶(nNOS)抑制剂后ERK1/2磷酸化的程度.结果:高糖浓度下,细胞虽有增殖但幅度及时程明显低于对照组,高糖抑制Schwann细胞生长;随着精浓度的升高.ERK1/2磷酸化的程度逐渐增加,并与加入nNOS抑制剂有相似的表现.结论:高糖抑制Schwann细胞生长,并且降低nNOS的量,减弱一氧化氮(NO)对ERK1/2的抑制作用,导致ERK1/2磷酸化水平升高.     

经皮穿刺椎间盘髓核摘除术入路的研究

为提供椎间盘髓核摘除术形态学依据，在7具成人横断面标本上观察测量了L1～L5椎间盘平面经皮穿刺椎间盘髓核摘除术的进针点、角度和深度。发现在L1～L3、L4～L5椎间盘髓核的穿刺点以距后正中线8～10cm，9～11cm，穿刺角度以46．7°～59．5°，穿刺深度为110．2～128．9mm为最宜。     

Regulation of the association between PSTPIP and CD2 in murine T cells

Prominent in T cells and natural killer cells, CD2 binding protein 1 (CD2BP1) plays an important role in CD2-mediated adhesion and signal transduction. In the current study, we investigated CD2 and PSTPIP (proline, serine, threonine phosphatase interacting protein, murine homologue of CD2BP1) interactions in purified mouse splenic T cells. PSTPIP associated with CD2 in both resting and activated T cells. Following various stimuli, such as concanavalin A, anti-TCRbeta, anti-CD3epsilon, anti-CD3epsilon/phorbol myristate acetate (PMA), IL-2, or PMA/ionomycin, PSTPIP and CD2 expression, as well as their association, increased in a time-dependent fashion. While PSTPIP expression and CD2 expression were comparable across most groups, the PSTPIP-CD2 association stimulated by anti-CD3epsilon alone was significantly greater than with other stimuli. Stimulation by anti-CD3epsilon plus anti-CD28 induced even greater PSTPIP-CD2 association than anti-CD3epsilon treatment alone, indicating that CD28 initiated signals are involved in regulating this interaction. There was no direct association between CD3epsilon or CD28 and PSTPIP. Tyrosine phosphorylated PSTPIP bound poorly to CD2 compared to dephosphorylated PSTPIP, and protein tyrosine phosphatase was shown to affect both phosphorylation of PSTPIP and the CD2-PSTPIP association. In addition to CD2, PSTPIP associated with CD4, CD8, CD54, and CD62L. CD2 and CD4 ligation reciprocally regulated their association with PSTPIP. These findings indicate that T cell activation, particularly through the CD3 and CD28 signal transduction pathways, regulates PSTPIP-CD2 interactions. PSTPIP likely has additional broader effects through interactions with CD4, CD8, CD54, and CD62L, and this may influence T cell responses to antigen.     

Identification of a novel mutation in patients with medium-chain acyl-CoA dehydrogenase deficiency

A novel mutation was identified in two unrelated patients with medium-chain acyl-CoA dehydrogenase deficiency. First, a 19-year-old Caucasian female presented with a devastating illness, resulting in sudden death in adulthood which is unusual. The second patient, now a 3.5-year-old male, presented at 17 months of age with a hypoglycemic seizure and dehydration. Sequence analysis revealed a novel mutation G617T in exon 8 resulting in an arginine to leucine substitution at codon 206 (R206L). Both patients were compound heterozygous for this G617T and the common mutation A985G.     

大鼠再生肝对二乙基亚硝胺启动作用的敏感性

目的比较再生肝和正常肝对二乙基亚硝胺（ＤＥＮ）启动作用的敏感性。方法以２／３肝叶切除后８周末的大鼠为实验组,正常大鼠为对照组,作如下比较：肝重、常规组织学检查及３Ｈ－ＴｄＲ掺入试验;用修改的Ｓｏｌｔ－Ｆａｒｂｅｒ模型,通过对ＧＧＴ阳性癌前病灶的体视学测量,观察肝脏对ＤＥＮ的启动效应;在体内和体外（无血清原代培养肝细胞）经ＤＥＮ攻击后,以核酸原位缺口标记方法观察肝细胞ＤＮＡ的损伤程度。结果２／３肝叶切除后８周末的实验组肝脏的修复过程已完成,未见肝细胞继续增生的表现;经ＤＥＮ攻击后,实验组肝癌前病灶在数密度和体积密度上都显著高于对照组;无论在体内或体外接受ＤＥＮ攻击后,实验组肝细胞ＤＮＡ的损伤程度都显著大于对照组。结论即使再生过程已经完成,再生肝仍比正常肝具有较高的致癌敏感性,这与再生肝肝细胞在ＤＥＮ攻击后其ＤＮＡ损伤较重相关。     

Intradialytic systolic blood pressure variation can predict long-term mortality in patients on maintenance hemodialysis

International Urology and Nephrology - It is unclear which time-points of intradialytic blood pressure (BP) best predict prognosis. Thus, it is important to assess the association between different...     

An Environmental Dilemma for China During the COVID-19 Pandemic: The Explosion of Disposable Plastic Wastes

Plastic pollution control has been on top of the political agenda in China. In January 2020, China announced a phased ban on the production and usage of various types of single-use plastics as a solution to environmental pollution problems. However, the outbreak of COVID-19 seems to be a new obstacle to the ban on single-use plastic products. To basically satisfied the daily necessities and contain the spread of SARS-CoV-2 under the background of the regular epidemic prevention and control in China, online ordering, contactless delivery and wearing mask have become an important and feasible way of daily life. However, the unrestrained use of disposable plastic bags, lunch boxes and masks within the nationwide quarantine leads to hundreds of millions of plastics wastes every day. The potential environmental pollution caused by the use of disposable plastic products during the pandemic should arouse social concern. The Chinese government should manage environmental protection in parallel with anti-pandemic endeavors as the situation of the pandemic evolves.

     

步枪立姿射击稳定性的力学特征

射击运动技术是衡量运动员水平的关键，它对运动员姿态控制的稳定性有相当高的要求。本文以步枪立姿运动为例，分析其姿态控制的力学特征，运用运动稳定性原理，求得人体上躯干最佳姿态控制角，并论证了人体躯干长度，前臂长度对稳定性的影响。最后将理论结果与对一些国内外著名运动员实测参数比较分析，证明了理论结论与实际基本相符。     

RNA silencing: a conserved antiviral immunity of plants and animals

RNA silencing is a novel RNA-guided gene regulatory mechanism operational in a wide range of eukaryotic organisms from fission yeast, plants, to mammals. This article reviews the recent progress on aspects of RNA silencing that are related to its biological function as a conserved antiviral immunity of plants and animals, and highlights features of this novel antiviral response in invertebrate animals as compared to the known innate and adaptive immunities. Finally, we discuss evidence that suggests a natural antiviral role for RNA silencing in vertebrates as well as experimental approaches that may facilitate the identification of first mammalian viral suppressors of RNA silencing.