大麻素抑制大鼠三叉神经节神经元ATP激活电流

本文在培养的大鼠三叉神经节(trigeminal ganglion,TG)神经元上采用全细胞膜片钳技术,探讨大麻素对大鼠TG神经元ATP激活电流(ATP-activated currents,IATP)的影响.结果显示(1)胞外给予ATP,大部分受检细胞(67/75,89.33%)可记录到一个内向电流,且具有剂量依赖性.该电流可被P2X嘌呤受体特异性拮抗剂PPADS所阻断.(2)预加WIN55212-2[大麻素受体1(cannabinoid receptor 1,CB1受体)激动剂]可对IATP产生抑制作用,此作用呈剂量依赖性,并可被CB1受体特异性拮抗剂AM281阻断.预加不同浓度的WIN55212-2(1x10-13、1x10-12、1x10-11、1x10-10、1x10-9和1x10-8mol/L)对IATP(1x10-4mol/L ATP)的抑制作用分别为(8.14±3.14)%、(20.11±2.72)%、(46.62±3.51)%、(72.16±5.64)%、(80.21±2.80)%和(80.59±3.55)%.(3)预加WIN55212-2后IATP的浓度-反应曲线明显下移;最大反应浓度时的IATP幅值减小了(58.02±4.21)%,而阈值基本不变;预加WIN55212.2前后曲线的EC50值非常接近(1.15x10-4mol/L vs 1.27x10-4 mol/L).(4)预加forskolin[腺苷酸环化酶(adenylyl cyclase,AC)激动剂]或8-Br-cAMP可以逆转WIN55212-2对IATP的抑制作用.以上结果表明,大麻素可能作用于CB1受体,通过抑制AC-cAMP-PKA途径发挥对IATP的抑制作用.     

线粒体ATP敏感钾通道对大鼠肺动脉平滑肌细胞低氧诱导因子-1α表达及细胞增殖的作用

本文旨在探讨线粒体ATP敏感钾（mitochondrial ATP-sensitive K＋,MitoKATP）通道对大鼠肺动脉平滑肌细胞低氧诱导因子-1α（hypoxia inducible factor-1α,HIF-1α）表达和细胞增殖的影响。原代培养大鼠肺动脉平滑肌细胞,分为常氧对照组、常氧＋diazoxide（MitoKATP通道的选择性开放剂）组、常氧＋5-hydroxydecanoate（5-HD,MitoKATP通道的选择性阻断剂）组、低氧对照组、低氧＋diazoxide组、低氧＋5-HD组,共6组,分别应用罗丹明123荧光技术检测各组大鼠肺动脉平滑肌细胞的线粒体膜电位,免疫组化检测HIF-1α的表达及酶联免疫检测仪检测细胞增殖的变化。结果显示,常氧＋ diazoxide组与常氧对照组比较,罗丹明123荧光、HIF-1α表达及细胞增殖明显增强（P〈0．05）;低氧＋diazoxide组与低氧对照组比较,罗丹明123荧光、HIF-1α表达及细胞增殖明显增强（P〈0.05）：常氧＋5-HD组与常氧对照组比较,罗丹明123荧光、HIF-1α表达、细胞增殖没有明显变化（P〉0．05）;但低氧＋5-HD组与低氧对照组比较,罗丹明123荧光明显减弱、HIF-1α表达及细胞增殖有所减弱（P〈0．05）。结果提示：MitoKATP通道的开放能引起大鼠肺动脉平滑肌细胞线粒体膜去极化,并可以促进HIF-1α的表达及细胞增殖。     

低氧条件下大鼠肺动脉平滑肌细胞中活性氧与低氧诱导因子-1α和细胞增殖的关系

在低氧条件下,观察大鼠肺动脉平滑肌细胞（pulmonary arterial smooth muscle cells,PASMCs）中活性氧（reactive oxygen species,ROS）的变化,探讨ROS的变化是否通过调控低氧诱导因子-4α（hypoxia-inducible factor 1α, HIF-1α）的表达影响PASMCs的增殖。采用组织块法原代培养大鼠PASMCs,分成3组：常氧组（21％O2,24h）,低氧组（5％O2,24h）,低氧＋Mn-TBAP组（5％O2,24h,Mn-TBAP是一种ROS清除剂）。用激光共聚焦显微镜荧光染色法检测细胞内ROS的变化;用RT-PCR和免疫组织化学方法分别测定HIF-1α mRNA和蛋白的表达;用MTT法检测细胞增殖程度。结果显示：（1）低氧组PASMCs内ROS水平明显高于常氧组（P〈0．05）,低氧＋Mn-TBAP组ROS水平明显低于低氧组（P〈0．05）,但仍高于常氧组（P〈0．05）;（2）低氧组及低氧＋Mn-TBAP组的HIF-1α mRNA和蛋白表达均高于常氧组（P〈0．05）,且低氧组表达高于低氧＋Mn-TBAP组（P〈0．05）;（3）低氧组细胞增殖明显高于常氧组和低氧＋Mn-TBAP组（P〈0．05）,低氧＋Mn-TBAP组细胞增殖高于常氧组（P〈0．05）。结果表明：在低氧条件下大鼠PASMCs中ROS水平明显升高,RROS的变化能够调节HIF-1α的表达,进而影响平滑肌细胞的增殖,提示ROS可能在肺动脉高压的发病机制和低氧信号转导中具有重要作用。     

拟环纹狼蛛对褐飞虱的捕食作用及其模拟模型的研究 Ⅳ.单种捕食者-两种猎物系统的模拟模型及其稳定性分析

本文提出了描述单种捕食者-两种猎物系统的模拟模型。在功能反应和选择捕食实验的基础上,应用数值模拟方法分析了模型中各参数对稳定性的影响,以及拟环纹狼蛛-褐飞虱、稻纵卷叶螟三物种系统的稳定性。     

Protection by hydroxychloroquine prevents placental injury in obstetric antiphospholipid syndrome

Obstetric antiphospholipid syndrome (OAPS) is mediated by antiphospholipid antibodies (aPLs, and anti‐β2 glycoprotein I antibody is the main pathogenic antibody), and recurrent abortion, preeclampsia, foetal growth restriction and other placental diseases are the main clinical characteristics of placental pathological pregnancy. It is a disease that seriously threatens the health of pregnant women. Hydroxychloroquine (HCQ) was originally used as an anti‐malaria drug and has now shown benefit in refractory OAPS where conventional treatment has failed, with the expectation of providing protective clinical benefits for both the mother and foetus. However, its efficacy and mechanism of action are still unclear. After clinical data were collected to determine the therapeutic effect, human trophoblast cells in early pregnancy were prepared and treated with aPL. After the addition of HCQ, the proliferation, invasion, migration and tubule formation of the trophoblast cells were observed so that the therapeutic mechanism of HCQ on trophoblast cells could be determined. By establishing an obstetric APS mouse model similar to the clinical situation, we were able to detect the therapeutic effect of HCQ on pathological pregnancy. The normal function of trophoblast cells is affected by aPL. Antibodies reduce the ability of trophoblast cells to invade and migrate and can impair tubule formation, which are closely related to placental insufficiency. HCQ can partially reverse these side effects. In the OAPS mouse model, we found that HCQ prevented foetal death and reduced the incidence of pathological pregnancy. Therefore, HCQ can improve pregnancy outcomes and reverse the aPL inhibition of trophoblast disease. In OAPS, the use of HCQ needs to be seriously considered.     

耐高盐枯草芽孢杆菌XP合成球形纳米硒及其抑制草莓病原真菌生物活性

生物方法合成纳米材料具有低能耗、高安全性以及环境友好等优良特点,因而备受人们关注.利用细菌将硒酸盐或亚硒酸盐还原为单质硒,不仅可以降低硒毒性,而且还能获得价值更高的生物纳米材料.文中选用可耐受高盐环境胁迫的枯草芽孢杆菌亚种Bacillus subtilis subspecies stercoris strain XP构...     

氯通道:在心脏中起何作用?

在心脏中发现氯通道已有十余年,目前已知氯通道是一类成员较多的离子通道超家族。心肌氯通道的作用可能是多重的,由于阻断氯通道或Cl^-替代对心肌的电特性产生明显影响,而心肌氯通道的种类和分布又存在明显的种属差异,提示心肌氯通道的主要作用可能在于调控阳离子通道,或为阳离子通道的正常活动提供一个合适的离子环境。因此,研究氯通道与阳离子通道之间的关系可能有重要的生理和病理生理学意义。     

Protection against oxidative stress by vitamin D in cone cells

Photoreceptor degeneration (PD) refers to a group of heterogeneous outer retinal dystrophies characterized by the death of photoreceptors. Both oxidative stress and inflammation are involved in the pathogenesis of PD. We investigate whether vitamin D has a potential for the treatment of PD by evaluating the anti‐oxidative stress and anti‐inflammatory properties of the active form of vitamin D₃, 1,α, 25‐dihydroxyvitamin D₃, in a mouse cone cell line, 661W. Mouse cone cells were treated with H₂O₂ or a mixture of H₂O₂ and vitamin D; cell viability was determined. The production of reactive oxygen species (ROS) in treated and untreated cells was measured. The expression of key anti‐oxidative stress and inflammatory genes in treated and untreated cells was determined. Treatment with vitamin D significantly increased cell viability and decreased ROS production in 661W cells under oxidative stress induced by H₂O₂. H₂O₂ treatment in 661W cells can significantly down‐regulate the expression of antioxidant genes and up‐regulate the expression of neurotoxic cytokines. Vitamin D treatment significantly reversed these effects and restored the expression of antioxidant genes. Vitamin D treatment also can block H₂O₂ induced oxidative damages. The data suggested that vitamin D may offer a therapeutic potential for patients with PD.