有氧运动对高蛋氨酸饮食大鼠血浆NO、ET和NO/ET系统的影响

目的：探讨有氧运动对高蛋氨酸饮食大鼠血浆总一氧化氮合成酶（T-NOS）、一氧化氮（NO）、内皮素（ET）和NO/ET系统的影响。方法：雄性Wistar大鼠随机分为正常饮食对照组（对照组）、高蛋氨酸饲料组（高蛋氨酸组）和有氧运动＋高蛋氨酸饮食组（运动干预组）。对照组喂饲普通饲料,高蛋氨酸组和运动干预组喂饲含3%蛋氨酸的高蛋氨酸饲料,运动干预组同时每日同时进行90 min无负重游泳运动,实验共8周。分别测定血浆同型半胱氨酸（Hcy）、ET、NO和T-NOS含量。结果：高蛋氨酸组血浆Hcy含量显著高于对照组达2倍以上（P〈0.01）,T-NOS和NO含量显著降低,ET含量显著升高（P〈0.01）,且NO/ET比值均显著降低（P〈0.05）;与高蛋氨酸组相比,运动干预组血浆Hcy含量显著下降（P〈0.05）,T-NOS,NO含量和NO/ET比值显著升高（P〈0.05）,且与对照组相比上述各项指标无显著差异。结论：高蛋氨酸饮食可诱发大鼠高同型半胱氨酸血症,血浆NO/ET失衡;有氧运动可降低高蛋氨酸饮食大鼠血浆Hcy水平,改善NO/ET失衡,预防高同型半胱氨酸血症。     

高蛋氨酸饮食对大鼠血管内皮细胞分泌功能的影响

目的:探讨高蛋氨酸饮食对大鼠血管内皮细胞分泌功能的影响。方法:雄性Wistar大鼠随机分为正常饮食对照组(对照组)和高蛋氨酸饮食组(高蛋氨酸组)。对照组喂饲普通饲料,高蛋氨酸组大鼠喂饲含3%蛋氨酸的饲料,共8周。采用高效液相色谱法测定大鼠血浆同型半胱氨酸含量,以MDA、SOD、NO/ET和t-PA/PAI平衡等指标建立研究平台和内皮功能评价体系,同时以扫描电镜观察主动脉弓血管内皮细胞形态。结果:与对照组相比,高蛋氨酸组血浆Hcy含量显著高于对照组,是对照组的2倍以上;血浆MDA和SOD活力显著升高(P<0.05),t-PA/PAI-1和NO/ET比值均显著降低(P<0.05)。扫描电镜显示高蛋氨酸组大鼠内皮细胞呈典型虫蛀样损害,伴有附壁血栓形成和脂质沉积。结论:高蛋氨酸饮食可诱发大鼠高半胱氨酸血症,Hcy可通过氧化应激机制损伤血管内细胞分泌功能,血浆NO/ET和t-PA/PAI-1系统失衡。     

针刺对胰岛素抵抗模型血管内皮功能的影响

目的:探讨针刺对实验性胰岛素抵抗模型大鼠血管内皮功能的影响.方法:将50只大鼠随机分成空白对照组、模型1组、模型2组、针刺1组、针刺2组,每组10只.采用高脂高糖高盐饲料喂养方法复制胰岛素抵抗模型.造模成功后,空白对照组继续以普通饲料喂养;模型1组继续以高脂高糖高盐饲料饲养;模型2组改为普通饲料喂养;针刺1组继续以高脂高糖高盐饲料喂养2周,同时给予针刺治疗,1次/d;针刺2组给予普通饲料喂养2周,同时给予针刺治疗,1次/d.治疗结束后继续取血观察各组大鼠的FPG、FINS、ISI、PGI2、TXA2、ET、NO的变化.结果:模型1组大鼠的FPG、FINS、ISI、TXA2、ET均较空白对照组升高(P＜0.01),而PGI2、NO低于空白对照组(P＜0.01).FPG、FINS、ISI、TXA2、ET在饮食及针刺联合干预的针刺2组中得到显著的改善,与针刺1组、模型1组及模型2组相比P＜0.01或P＜0.05;针刺1组与模型1组、模型2组相比,P＜0.05,模型2组与模型1组相比,P＜0.05.结论:胰岛素抵抗可造成血管内皮功能的损伤,针刺对胰岛素抵抗血管内皮功能的损伤具有一定的逆转效应,合理饮食可以促进这种效应.     

肾上腺髓质素2的降压作用及其机制

目的:研究肾上腺髓质素2(ADM2)拮抗血管紧张素Ⅱ(AngⅡ)发挥舒张血管的作用及机制。方法:将18只180~200 g雄性SD大鼠随机分为3组(n=6):对照组、AngⅡ(150 ng/(kg·min))组和AngⅡ(150 ng/(kg·min))+ADM2(500 ng/(kg·h))组,采用皮下埋植微量渗透泵的方法给药。2周后颈动脉插管法测量大鼠血压,测定血浆一氧化氮(NO)含量和内皮型一氧化氮合酶(eNOS)活性。DHE染色法检测大鼠动脉壁活性氧产生。制备大鼠离体血管环,观察ADM2的舒血管作用。培养人脐静脉内皮细胞系EA.hy 926,用DCFH-DA荧光探针检测AngⅡ和ADM2对血管内皮细胞活性氧释放的影响。结果:与AngⅡ组相比,ADM2显著降低了大鼠血压,血浆中eNOS活性提高、NO含量增加,血管壁活性氧产生减少。ADM2呈浓度依赖性和内皮依赖性舒张血管环,并明显抑制了AngⅡ引起的血管内皮细胞活性氧产生。结论:ADM2可能通过拮抗AngⅡ诱导的血管内皮氧化应激效应,改善内皮功能,发挥舒张血管、降低血压的作用。     

急性脑梗死患者血管内皮功能及同型半胱氨酸水平的变化

目的探讨急性脑梗死患者的治疗及其血管内皮功能、同型半胱氨酸水平变化。方法选择延安大学附属医院2015年8月至2016年12月收治的98例急性脑梗死患者为观察组,选择同期进行体检的98例健康者为对照组。对比2组患者血管内皮功能、Hcy水平及治疗前后各项指标的变化情况。结果治疗前观察组患者FMD、NO、eNOS水平显著低于对照组(t=-11.310、-7.669、-8.883,P0.05),IMT、Hcy水平高于对照组(t=21.416、24.333,P0.05)。治疗后,观察组患者Hcy水平显著下降(t=14.219,P0.05),NO、eNOS水平升高(t=-9.859、-11.131,P0.05);FMD水平无变化(t=-1.147,P0.05);NIHSS评分下降,BI评分升高(t=10.954、-10.797,P0.05)。结论 ACI患者血管内皮功能出现障碍,Hcy水平显著升高。叶酸及维生素B12临床疗效显著,可有效缓解血管内皮功能障碍,降低Hcy水平,改善患者预后。     

通心络对低氧预适应小鼠神经元超微结构及内皮细胞自修复能力的影响

目的：观察低氧预适应对小鼠脑皮层神经元和内皮细胞超微结构的改变及通心络的作用。方法：40只小鼠随机分为正常对照组、低氧组、低氧预适应组和通心络组（低氧预适应＋通心络）,利用重复低氧5次复制低氧预适应小鼠模型后,记录小鼠每次低氧耐受的时间,观察脑皮层神经元和血管内皮细胞超微结构的改变。结果：随着低氧次数的增加,预适应组和通心络组小鼠耐受时间增加（P〈0．05或P〈0．01）。与预适应组比较,通心络组小鼠耐受时间增加（P〈0．05或P〈0．01）;低氧组小鼠脑皮层内皮细胞和神经元超微结构发生明显改变,预适应组小鼠脑组织神经元及血管内皮细胞超微结构改善,通心络组脑组织神经元及血管内皮细胞超微结构明显改善。结论：低氧预适应显示出机体具有强大的自修复能力,通心络能明显增强机体的自修复能力,提高自适应。     

番茄红素对高同型半胱氨酸血症大鼠血管内皮舒缩功能和纤溶功能的影响

本文研究了补充番茄红素对高同型半胱氨酸血症大鼠血液Hcy的影响,及对血管内皮舒缩功能和纤溶功能的影响。SD大鼠30只,随机分为普通饮食组(C)、蛋氨酸饮食组(M)、蛋氨酸饮食+番茄红素组(ML)。ML组灌胃番茄红素(6.25 mg/kg),每天2 m L,其余组灌胃同等剂量生理盐水,共8周。末次实验后24 h,测试血浆Hcy、TXB2、6-Keto-PGF1α、t-PA和PAI。实验结果表明8周高蛋氨酸饮食可导致大鼠形成高同型半胱氨酸血症,血浆Hcy、TXB2和PAI显著升高(P0.01),6-Keto-PGF1α和t-PA显著降低(P0.01),血管舒缩和纤溶功能紊乱。但8周番茄红素补充可以显著降低血浆Hcy和TXB2,增加6-Keto-PGF1α含量,同时调节t-PA和PAI的活性,改善纤溶功能,预防动脉粥样硬化病的形成。     

长期高饱和、高不饱和脂肪酸饮食诱导胰岛素抵抗大鼠肾动脉舒张和收缩功能的变化

本文旨在探讨长期高饱和、高不饱和脂肪酸饮食诱导胰岛素抵抗（insulin resistance,IR）大鼠。肾动脉舒张和收缩功能的变化。成年Wistar大鼠随机分为对照组、高饱和脂肪酸组和高不饱和脂肪酸组,每组14只。喂养6个月后,用高胰岛素正常葡萄糖钳夹技术的葡萄糖输注率（glucose infusion rate,GIR）评价IR;用尾套法测定大鼠血压,同时比较三组大鼠的体重、血清甘油三酯、游离脂肪酸、胰岛素、空腹血糖和NO代谢产物NO2-／NO3-。大鼠处死后,取肾动脉放入生理盐溶液中,观察血管对各种因子的舒、缩反应。结果显示,喂养6个月后,与对照组大鼠比较,高饱和脂肪酸组和高不饱和脂肪酸组大鼠均出现血压升高、血清甘油三酯升高和胰岛素敏感性降低;体重、空腹血糖、胰岛素和游离脂肪酸均升高（P〈0．01）：而两高脂组间体重、空腹血糖、胰岛素和游离脂肪酸无显著性差异。高饱和脂肪酸组大鼠肾动脉对ACh的内皮依赖性最大舒张反应（Rmax）最低,其次为高不饱和脂肪酸组和对照组：对照组与两高脂组有显著性差异（P〈0．01）,而两高脂组间无显著性差异。血管经L-Arg孵育后,两高脂组肾动脉对ACh的内皮依赖性Rmax均比孵育前增加,经N^ω-吐硝基-L-精氨酸（N^ω-nitro-L-arginine,L-NNA）及美蓝（methyleneblue,MB）孵育后,两高脂组Rmax均比孵育前降低（P〈0．05,P〈0．01）;对照组各孵育液之间无显著性差异（P：〈0．05）。肾动脉对硝普钠的非内皮依赖性Rmax及对去甲肾上腺素的收缩反应,三组间无显著性差异（P〈0．05）。相关分析结果显示,肾动脉对ACh的内皮依赖性Rmax与收缩压、甘油三酯呈明显负相关,与NO2-／NO3-和GIR呈明显正相关,游离脂肪酸与N02-／NO3-呈明显负相关。结果提示,高饱和及高不饱和脂肪酸饮食均可引起高血压及与之密切相关的内皮依赖性血管舒张功能减弱、高脂血症和IR,高脂诱导内皮依赖性血管舒张功能减弱与L-Arg-NO-cGMP通路受损有关。     

超氧阴离子抑制大鼠肠系膜阻力血管内皮依赖性舒张功能

目的:研究超氧阴离子对大鼠肠系膜阻力血管内皮细胞超极化因子(EDHF)和一氧化氮(NO)引起的血管舒张作用的影响及其可能机制.方法:雄性Sprague-Dawley大鼠,取肠系膜血管三级分支约2 mm长血管环,置于DMT 610 M系统,记录张力变化.血管环浴液中加入焦酚建立超氧阴离子损伤模型.结果:焦酚(10,100,300和1 000 μmol/L)可浓度依赖性地引起乙酰胆碱(ACh)诱导的肠系膜阻力血管舒张功能减弱;其中,300 μmol/L焦酚显著减弱肠系膜血管环由ACh诱导的EDHF和NO介导的内皮依赖性血管舒张效应,但对硝普钠和吡那地尔引起的内皮非依赖性的血管舒张作用无明显影响.结论:超氧阴离子可减弱阻力血管内皮依赖性舒张反应,其机制可能与超氧阴离子抑制了阻力血管内皮细胞EDHF和NO的作用有关.     

高同型半胱氨酸血症促进大鼠血管钙化

目的:在大鼠血管钙化模型上,探讨高同型半胱氨酸血症对血管钙化的影响及其作用机制.方法:用维生素D3加尼古丁诱导大鼠血管钙化模型,并给以高蛋氨酸饮食六周诱导大鼠高同型半胱氨酸血症,用高效液相色谱法检测血浆总同型半胱氨酸(Hcy)水平;采用血管组织vonKossa染色、钙含量测定、碱性磷酸酶(ALP)活性和骨钙素(OC)含量测定以判断血管钙化程度,同时测定血浆脂质共轭烯(Diene键)含量反映其脂质过氧化水平.结果:钙化组大鼠血管yon Kossa染色可见大量黑色颗粒沉积,其血管的钙含量,碱性磷酸酶活性及骨钙素含量分别较对照组增加8.09倍、45.57%和2.81倍(P＜0.01).高蛋氨酸饮食的钙化组大鼠血管内钙含量较单纯钙化组增高了34.29%,而碱性磷酸酶活性及骨钙素含量则较单纯的钙化组降低29.13%和74.69%(P＜0.01).钙化组大鼠血浆脂质共轭烯含量与对照组比较无显著性差异,单纯高蛋氨酸饮食和钙化加高蛋氨酸饮食大鼠血浆脂质共轭烯含量较对照组增加了1.93和2.89倍(P＜0.01),而钙化加高蛋氨酸饮食大鼠血浆脂质共轭烯含量较单纯高蛋氨酸饮食大鼠又增加了32.90%(P＜0.01).结论:高同型半胱氨酸血症可以促进血管的钙化,可能与其所致的脂质过氧化程度增强有关.     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.