荠苧黄酮通过抑制氧化应激和炎症改善高原缺氧诱导的小鼠脑组织损伤

为了阐明荠苧黄酮对高原缺氧致脑组织损伤的保护作用和可能机制,本研究利用建立的低压低氧诱导脑组织损伤模型,考察了芥苧黄酮对高原缺氧小鼠脑组织中氧化应激和炎性因子等相关生化指标和蛋白表达的影响。结果发现:经荠苧黄酮预处理能够显著降低低压低氧小鼠脑组织中ROS、MDA和IL-1β、IL-6和TNF-α含量,提高SOD、CAT和GSH-Px等抗氧化酶的活性和GSH水平,降低IL-1β和TNF-α蛋白表达,提高SOD1和CAT蛋白表达。综上所述,荠苧黄酮对高原缺氧诱导脑组织损伤的保护作用与清除自由基、抑制炎性因子的释放、降低脑组织氧化应激和炎性反应有关。     

硫氧还蛋白系统与高氧肺损伤

动物实验和临床研究表明,长期高浓度供氧可引起新生儿尤其早产儿产生氧化应激性损伤,多数学者认为这种氧化应激损伤在高氧肺损伤发生发展中起关键作用. 高氧时,氧化应激对肺泡Ⅱ型上皮细胞(alveolar epithelial cell type Ⅱ,AECⅡ)的影响包括对肺泡上皮细胞的损伤和对肺泡上皮细胞的保护.AECⅡ存活与凋亡有赖于细胞内的氧化还原状态, 通过改变细胞内的氧化还原状态可干预氧化应激.硫氧还蛋白系统( thioredoxin system )在生物体内通过抗氧化和氧化还原调节, 在基因表达、信号转导、细胞生长、细胞凋亡等方面起重要作用.     

肌肉萎缩与氧化应激

肌肉是机体具有收缩性的组织,它的主要功能是通过力量产生引起机体各部位的运动.肌肉萎缩是肌肉质量和力量丧失,肌肉活动功能减退的一种反应,在许多生理和病理情况下都可以出现.肌肉萎缩时不仅表现为肌肉结构形态的变化,如肌肉的重量和体积减少,肌纤维类型改变,最主要是肌肉蛋白质水解作用增强、合成减少.氧化应激是机体氧化产物超过机体抗氧化防御能力一种应激状态,可以导致细胞、组织和器官的损伤.大量证据表明,氧化应激参与肌肉萎缩的致病过程.探讨氧化应激在肌肉萎缩中的作用,对了解肌肉萎缩的致病机制有重要作用.本文对氧化应激和肌肉萎缩的关系,氧化应激参与肌肉萎缩时的蛋白质水解途径,以及连接氧化应激和肌肉萎缩的两个重要细胞信号转导通路做一简要综述.     

血红素氧合酶-1 与肺纤维化

血红素氧合酶-1(Hene Oxygenase-1)是一种氧化应激反应蛋白,广泛存在全身各组织器官。HO-1及催化产物组成了重要的内源性保护系统,具有调控炎症、抗氧化损伤及抗细胞凋亡等作用,对于组织器官具有保护作用。肺纤维化发病机制复杂,氧化应激是肺纤维化的致病机制之一。HO-1是一种重要的抗氧化剂,其通过多种途径参与致病,在肺纤维化致病过程中发挥重要作用。     

定量蛋白质组学在急性高原病研究中的应用进展

急性高原病(acute mountain sickness,AMS)是人体急性暴露于高原低压低氧环境后出现多系统生理紊乱的临床综合征。定量蛋白质组学技术可以系统定量并描述机体蛋白质组成和动态变化规律,近年来在多种疾病的预防、诊断、治疗和发生机制等方面研究应用广泛。本文系统综述了定量蛋白质组学技术及其在AMS的预防、诊断、治疗和急进高原习服机制研究中的应用进展,以期为AMS的发病机制、提前干预、临床治疗和AMS的蛋白质组学研究提供参考。     

血红素氧合酶-1与肺纤维化

血红素氧合酶-1（Hene Oxygenase-1）是一种氧化应激反应蛋白,广泛存在全身各组织器官。HO-1及催化产物组成了重要的内源性保护系统,具有调控炎症、抗氧化损伤及抗细胞凋亡等作用,对于组织器官具有保护作用。肺纤维化发病机制复杂,氧化应激是肺纤维化的致病机制之一。HO-1是一种重要的抗氧化剂,其通过多种途径参与致病,在肺纤维化致病过程中发挥重要作用。     

间歇性低氧适应的心脏保护

间歇性低氧（intermittent hypoxia,IH）是指一定时间间断地暴露于低氧环境,而其余时间处于常氧环境。IH是机体某种生理和病理状态下的低氧形式。研究表明：间歇性低氧适应（IHadaptation）,类似缺血预适应（ischemic preconditioning,IPC）和长期高原低氧适应（long-termhigh-altitude hypoxic adaptation,LHA）,具有明显的心脏保护作用,表现为增强心肌对缺血／再灌注损伤的耐受性、限制心肌梗死面积和形态学改变、抗细胞凋亡、促进缺血／再灌注心脏舒缩功能的恢复,以及抗心律失常。尽管IH对心脏的保护作用不容质疑,但其作用机制远未阐明。IH心脏保护作用可能涉及氧的运输、能量代谢、神经体液调节、抗氧化酶、应激蛋白、腺苷系统、ATP敏感钾通道、线粒体及其钙调控、一氧化氮和蛋白激酶等多方面机制,并受低氧处理方式、动物年龄和性别等因素影响。IH心脏保护持续时间明显长于IPC,而对机体的不良影响远小于LHA,具有潜在的应用价值。     

复方中药制剂在寒冷诱导机体损伤中作用及其机制

目的:研究寒冷所诱导的机体损伤作用,明确寒冷引发机体损伤的部分机制以及预防性药物对机体处于寒冷环境中的保护作用。方法:通过低温试验、ATP检测、电镜观察等确定寒冷对机体造成的损伤;通过总抗氧化能力、CAT含量、谷胱甘肽过氧化物酶含量、SOD水平、MDA水平等的检测确定氧化应激在寒冷暴露对机体损伤中的作用及机制;并确证复方中药制剂在寒冷损伤氧化应激状态下对机体的保护作用。结果:1.急性-15±1℃寒冷环境暴露可引起机体内肝脏组织能量代谢障碍,ATP生成减少,肝细胞线粒体损伤,溶酶体增多等机体损伤的现象;2.寒冷应激可导致机体的总抗氧化能力、CAT显著减少,而氧化应激终产物之一的丙二醛(malondialdehyde,MDA)显著增多(说明肝脏组织出现明显的氧化应激过程),并且出现抗氧化能力下降。3.预先给予药物干预后,机体抗氧化能力显著增加。结论:1.寒冷可以诱导机体肝脏明显损伤。2.氧化应激是寒冷诱导机体损伤的关键机制之一。3.复方中药制剂可以增加机体在寒冷应激条件下的抗氧化能力,从而产生保护作用。     

硫氧还蛋白系统在COPD抗氧化中的作用研究进展

硫氧还蛋白系统是由硫氧还蛋白（thioredoxin,Trx）,硫氧还蛋白还原酶（thioredoxinreductase,TrxR）和还原型辅酶Ⅱ（NADPH）组成的多功能小分子蛋白系统,广泛表达的硫氧还蛋白作为蛋白质二硫键的还原酶,它参与很多生理过程,并发挥重要生物学功能,包括调节机体的氧化还原反应、抑制细胞凋亡、调节转录因子DNA结合活性以及免疫应答等,其中一重要作用是参与调节细胞氧化还原状态以对抗氧化应激。因此在一些炎症性疾病如慢性阻塞性肺疾病、急性呼吸窘迫综合征、肺间质疾病、哮喘、肺结节病等的发生发展中扮演重要角色,本文对硫氧还蛋白系统在慢性阻塞性肺疾病中的抗氧化作用作一综述。     

硫氧还蛋白系统在COPD抗氧化中的作用研究进展

硫氧还蛋白系统是由硫氧还蛋白(thioredoxin,Trx)、硫氧还蛋白还原酶(thioredoxin reductase,TrxR)和还原型辅酶Ⅱ(NADPH)组成的多功能小分子蛋白系统,广泛表达的硫氧还蛋白作为蛋白质二硫键的还原酶,它参与很多生理过程,并发挥重要生物学功能,包括调节机体的氧化还原反应、抑制细胞凋亡、调节转录因子DNA结合活性以及免疫应答等,其中一重要作用是参与调节细胞氧化还原状态以对抗氧化应激。因此在一些炎症性疾病如慢性阻塞性肺疾病、急性呼吸窘迫综合征、肺间质疾病、哮喘、肺结节病等的发生发展中扮演重要角色,本文对硫氧还蛋白系统在慢性阻塞性肺疾病中的抗氧化作用作一综述。     

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.     

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.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.