肠道菌群在代谢手术改善肥胖代谢性疾病中的研究进展

肥胖不仅是体内脂肪细胞的增加,而且是机体代谢状态的异常改变,导致肥胖患者出现2型糖尿病、非酒精性脂肪性肝病、心血管疾病和多囊卵巢综合征等代谢紊乱性疾病。代谢手术在减重的同时,能够治疗和缓解由肥胖导致的相关疾病。对代谢手术改善肥胖及其合并症的机制研究发现,肠道微生物在术后显著改变,这促使肠道菌群及其代谢产物（短链脂肪酸和胆汁酸）等成为代谢手术改善代谢效应机制研究的热点。随着粪菌移植和口服益生菌治疗肥胖及其合并症的报道,进一步验证了肠道菌群在改善肥胖及其相关并发症中发挥有益作用。本综述将总结肠道菌群在代谢手术领域中的最新研究进展。     

Akkermansia muciniphila作为下一代益生菌的潜力

近年诸多证据表明肠道菌群在相当程度上介导了机体的代谢健康和疾病风险。Akkermansia muciniphila（A. muciniphila）是一种重要的肠道微生物，于2004年首次被发现。在肥胖、糖尿病和肿瘤等代谢及炎症性疾病患者体内A. muciniphila的含量显著降低，增加肠道中的该菌可有效改善疾病状况，作用机制可能与A. muciniphila增强肠道黏膜屏障功能，抑制微生物移位，降低系统炎症等相关。因此，本文就A. muciniphila与疾病的相关性、作用机制以及其作为下一代益生菌的潜力进行综述，以期为该菌的开发和应用提供参考。     

肠道菌群对2型糖尿病的调节机制

2型糖尿病(type 2 diabetes mellitus,T2DM)是一种遗传和环境因素共同作用的复杂的代谢性疾病,约占糖尿病患者总数的90％以上。以往,人们一直认为导致T2DM发生的肥胖是外部因素所致,但目前已有证据表明,身体内部因素同样是导致肥胖的诱因之一。人体微生物群的最新研究表明,个体肠道中的特定菌群可能促进肥胖、炎症或胰岛素抵抗的发生,最终诱发T2DM。这使得肠道菌群及其在T2DM中的作用以及肠道益生菌的潜在治疗价值成为T2DM领域中的一个重要研究方向。本综述旨在通过研究健康人群和T2DM患者肠道菌群的分布,探讨肠道菌群与T2DM的相互作用及调节机制。     

丁酸菌与老年肠道功能的相关性

丁酸菌是一种专性厌氧芽胞杆菌,是以丁酸为主要代谢产物的益生菌,可定植于人体肠道,在某种程度上与乳酸菌有协同作用,可抑制人肠道内有害菌的生长、促进营养物质的吸收、改善肠道功能等。本研究主要对丁酸菌在临床中的应用研究进展进行综述,尤其是对丁酸菌与老年人肠道功能的相关性进行阐述,并展望丁酸菌对老年慢性疾病如糖尿病、心血管疾病、老年痴呆、风湿性疾病及骨质疏松症防治的研究未来。     

基于调节肠道菌群的功能性低聚糖改善肥胖的研究进展

肥胖是机体脂肪积聚过多的一种典型的能量过剩疾病,是导致2型糖尿病和心血管疾病等一系列代谢性疾病的主要原因之一,已成为威胁全球健康的重大公共卫生问题。肠道菌群作为机体能量代谢调控的重要参与者,在肥胖及相关代谢性疾病的发生发展中起着关键作用,通过饮食干预调节肠道菌群,进而改善机体健康状况将是未来的研究热点之一。已有研究表明,功能性低聚糖作为一类典型的新型益生元,可调节肠道菌群结构及其代谢产物的水平,影响机体能量代谢过程,改善肥胖及相关代谢性疾病。本文主要对肠道菌群在肥胖中的潜在作用机制,以及常见功能性低聚糖调节肠道菌群改善肥胖的作用效果进行综述,以期为通过靶向肠道菌群精准干预肥胖及相关代谢性疾病提供一些新的潜在防治策略。     

肠道菌群在糖尿病发生发展中的作用机制研究进展

糖尿病已经成为严重威胁人类健康的疾病之一。目前已有研究证明肠道菌群在糖尿病的发生、发展中发挥着重要作用。肠道菌群在人体中处于动态平衡,但容易受到饮食、环境、细菌的相互作用以及抗菌药物等多种因素的影响。肠道菌群的变化可以导致肥胖、胰岛素抵抗、肠道渗透压改变以及代谢性内毒素血症等,从而促进糖尿病(1型及2型)的发生、发展,而益生菌在预防糖尿病的发生和改善糖尿病预后中的作用不可小视。本文从糖代谢、脂代谢、免疫及并发症等方面分析肠道菌群影响糖尿病发生发展的机制。     

2型糖尿病肠道菌群研究进展

2型糖尿病是一种常见的慢性消耗性疾病,其发病机制十分复杂,流行病学研究表明,肥胖、高热量饮食、体力活动不足及年龄增大是2型糖尿病最主要的环境因素。它是一种以胰岛素抵抗和胰岛素分泌不足为特征的代谢性疾病。肠道菌群作为进入人体的一个重要环境因素,肠道微生物的菌群变化影响宿主能量物质的吸收,调节肠道的分泌功能和非特异性免疫功能,从营养、代谢、疾病等各方面与我们生命活动相关。肠道菌群已成为我们身体的一部分,影响宿主的免疫,在肥胖、糖尿病、代谢综合征等疾病中都具有非常重要的作用。     

肠道菌群影响宿主肥胖的研究进展

越来越多的研究结果表明,肠道菌群与宿主消化、呼吸、内分泌、心血管、神经等系统发生的疾病密切相关。目前,全世界患肥胖和Ⅱ型糖尿病的人逐渐增多。肠道菌群的平衡有利于维持宿主正常的能量代谢过程,而肠道菌群失调使机体产生慢性炎症反应及胰岛素抵抗,从而导致肥胖和Ⅱ型糖尿病等代谢性疾病的发生。本文综述了肠道菌群影响肥胖的机制,以及通过调控肠道菌群改善肥胖的方法。     

益生菌与中药在改善肥胖中的研究进展

近些年来,越来越多的研究发现肠道菌群在肥胖的发生发展中起重要作用.研究证实口服益生菌制剂,可以有效的改善肥胖,而中国传统中药在治疗肥胖上也具有独特优势.本文就肠道菌群与肥胖的发生发展的关系,益生菌、中药以及其相互作用在改善肥胖中的研究进展做一综述.     

脑-肠轴在缺血性脑卒中及其并发症中的机制探索与应用展望

脑卒中严重危害人类健康,是我国单一病种致死与致残首因.预防脑卒中事件及其并发症,改善患者疾病结局,是神经病学领域的研究重点.肠道菌群可通过免疫、内分泌和神经等通路,直接或间接影响大脑功能和宿主行为.最新研究表明,脑卒中发生前基础疾病,急性期脑缺血事件,以及卒中后并发症,均与肠道菌群紊乱存在因果关联.本综述讨论了肠道菌群在脑卒中危险因素例如肥胖、糖尿病、高血压与动脉粥样硬化等疾病中的病因角色;急性缺血性脑卒中存在由脑到肠,再由肠到脑的因果交互驱动新机制;肠道菌群及其代谢产物参与了脑卒中相关并发症,如脑卒中后抑郁、认知障碍、感染与睡眠障碍等研究进展.此外,益生菌干预等新型疗法有潜力改善脑卒中危险因素、事件与并发症的结局,但仍需进一步的基础与临床研究探究益生菌的作用机制与应用价值.脑卒中系列疾病中大脑与肠道存在互作机制,肠道菌群及其代谢物扮演了重要角色,阐明脑-肠轴相关机制对脑卒中及其并发症的预防、诊断和治疗具有重要意义.     

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.