肠道菌群在脊髓损伤后胃肠道炎症反应中的研究进展

脊髓损伤(spinal cord injury, SCI)目前尚无有效的治疗手段。脊髓损伤后,患者常伴有严重的胃肠功能障碍,严重影响患者的生活质量。研究发现,脊髓损伤后肠道菌群的紊乱和脊髓损伤后的胃肠道功能障碍密切相关。因此,本文围绕脊髓损伤后肠道菌群的变化,探讨肠道菌群在迷走神经、下丘脑-垂体-肾上腺和肠道菌群代谢物3个途径中发挥的作用,及与胃肠道炎症反应相关的研究进展。     

肠道菌群影响脊髓损伤后焦虑情绪的研究进展

脊髓损伤作为一种严重的创伤性应激可以引发焦虑情绪,对患者心理健康造成极大影响。研究发现,脊髓损伤后肠道菌群失调与焦虑情绪的发生存在密切联系,因此本文从5-羟色胺系统失调、多巴胺系统失调、脑源性神经营养因子缺乏及炎症反应4个方面,探讨脊髓损伤后肠道菌群改变影响焦虑情绪发生的机制,为今后治疗脊髓损伤后焦虑情绪的深入研究和药物开发提供理论依据。     

肠道菌群与肿瘤化疗之间的互作关系

化疗药物的应用是当今治疗恶性肿瘤的主要方法之一。近年来,随着对人体微生物研究的不断深入,肠道菌群在疾病的诊断和治疗中发挥越来越重要的作用。肠道菌群具有调节炎症反应、维持肠道屏障功能稳定和调节免疫反应的作用,其菌株可能作为一种潜在的肿瘤诊断标志物。肠道菌群与化疗药物之间的关系越发紧密,如肠道菌群如何影响化疗药物的作用效果,恶心、呕吐、便秘、骨髓抑制等化疗药物的毒副作用对肠道菌群又有何种影响,应用益生菌后肠道菌群如何变化以及对化疗药物毒副作用有何影响。因此,本文回顾了化疗药物与肠道菌群相互作用研究的进展,希望为国内学者提供肠道菌群和癌症化疗之间关系的理论基础,并为治疗癌症提供新的研究思路。     

肠道菌群与神经系统疾病

人类肠道菌群是数以万亿的细菌组成的高度多样化的生态系统,菌群失调与多个系统疾病有关联。肠道菌群通过菌群-肠-脑轴与神经系统多途径双向互作,能引起神经免疫炎症反应、肠黏膜和血脑屏障功能改变、直接刺激迷走神经和肠道神经系统脊神经、神经内分泌-下丘脑-垂体-肾上腺轴,造成神经系统疾病。肠道菌群的代谢产物也有一定的作用。文中综述自闭症谱系障碍、多发性硬化、帕金森病、癫痫、吉兰巴雷综合征、阿尔茨海默病、视神经脊髓炎、肝性脑病、肌萎缩侧索硬化、精神分裂症、抑郁症、慢性疲劳综合征、亨廷顿病、脑卒中等肠道菌群改变特征及其干预措施的研究进展。目前肠道菌群的研究还处在初级阶段,因果关系和机制方面的研究比较少,这对精准实施菌群临床干预措施具有重要意义,期待将来有所突破成为一些神经系统疾病治疗的新路径。     

肠道菌群与精神分裂症的研究进展

精神分裂症是一种精神障碍疾病。除了遗传因素外,一些环境因素也参与了精神分裂症的发生,肠道微生物群是近年来发现的主要影响因素之一。研究表明,精神分裂症患者肠道菌群普遍发生了紊乱,肠道菌群通过肠-脑轴影响神经功能和疾病。肠道菌群可以通过影响神经系统发育、免疫和代谢功能来诱导精神分裂症的发生,肠道菌群可能是精神分裂症防治的有效靶点,调节肠道菌群可能是防治精神分裂症的一种潜在方法。本文就精神分裂症的易感因素、肠道菌群在精神分裂症中的作用、机制以及防治策略等方面的研究进展进行综述。     

化疗对肠道菌群及血清5-羟色胺水平的影响

化疗不仅导致肠黏膜炎和5-羟色胺(5-HT)水平的异常,也会诱发肠道菌群失衡。平衡状态下的微生物是一道生物屏障,菌群失衡可加剧肠道炎症。近期研究发现,5-HT的水平受肠道菌群的调节。因此,化疗引起的5-HT水平改变可能与肠道菌群的异常有关。本研究主要探讨肠道菌群通过何种途径影响化疗后肠黏膜炎和5-HT水平,为临床上以益生菌调节肠道菌群来改善化疗后的胃肠道反应提供依据。     

肠道屏障损伤及细菌移位在焦虑抑郁症诱导退行性神经症中的机制

肠道屏障是脑-肠道交互作用的晴雨表。健全的肠道屏障对于维系肠道内微生态,抵御外源性病原体的侵入至关重要。焦虑抑郁症能够损害肠道屏障,破坏肠道菌群平衡。肠道屏障损伤引起肠道渗透性升高,肠腔细菌移位,促使外源性病原体进入血液循环和神经系统,启动系统性炎症反应。炎症反应对脑神经的损伤是诱导阿尔茨海默病和帕金森症发生、发展的主要原因。肠道屏障损伤还会破坏原有的肠道菌群结构,造成肠道菌群失调,不仅进一步损伤肠道屏障,还影响神经组织的结构和功能,是阿尔茨海默病和帕金森症形成的另一因素。此综述依据近年来的相关研究,从肠道屏障损伤的角度阐述了焦虑抑郁症触发退行性神经症的机制,强调维护肠道屏障功能在预防退行性神经疾病中具有重要的临床意义。     

口腔及肠道菌群与冠心病关系的研究进展

冠心病是由多种病理因素引起的复杂疾病,严重威胁人类健康,其机制尚未完全阐明。近年来,研究表明冠心病与口腔和肠道菌群密切相关。菌群失调导致的炎症反应、氧化应激反应、脂质代谢失调和氧化三甲胺累积是参与冠心病发生的主要风险因素。此外,口腔菌群与肠道菌群相关,参与冠心病的发生与发展。中医治疗疾病的优势在于辨证论治,而证型的判断缺乏客观标准。多项研究应用口腔菌群或肠道菌群分析了疾病的中医证型。本文系统地阐述了口腔菌群和肠道菌群在冠心病发病机制中的作用,阐述了不同中医证型冠心病菌群分析的研究进展,为临床开展此类研究提供参考。     

肠道菌群与神经精神系统疾病研究进展

过去,我们认为大脑通过激素、神经系统调控胃肠道功能。现在,越来越多的研究聚焦于脑肠轴(brain-gut-axis)。该通路的重要参与者——肠道菌群(gut microbiota)也可以通过肠道神经系统、神经内分泌系统以及神经免疫系统调控大脑功能,进而影响疾病的发生发展,如癫痫、阿尔茨海默症、自闭症、情绪障碍等。总而言之,肠道菌群可能是情绪、认知、疼痛、饮食习惯、睡眠等的关键调节者,并且可能参与了从情感性疾病到神经系统疾病(如癫痫、阿尔茨海默症和自闭症等)的发生发展。研究肠道菌群与人类癫痫、神经退行性疾病以及精神疾病的相互作用关系及其机制,对重新认识神经精神相关疾病的发生发展、优化治疗措施至关重要。     

肠道菌群调节与缺血性脑卒中的中西医治疗研究进展CSCD

肠道菌群与大脑之间通过肠道菌群-肠-脑轴进行双向调节。研究表明,肠道菌群与缺血性脑卒中(ischemic stroke,IS)密切相关,肠道菌群失调通过影响血压、动脉粥样硬化、免疫、神经内分泌和炎症等途径干预IS的发生发展。IS发生后的自主神经功能紊乱和应激反应等又会导致肠道菌群失调,进一步加重脑损伤。因此,肠道菌群可能是临床预防和治疗IS的一个潜在靶点。本文综述了基于肠道菌群调节的中西医结合治疗IS的研究进展,对益生菌、粪菌移植、抗生素及中药在调节肠道菌群,改善IS脑损伤的作用及潜在机制方面进行深入探讨,以期为IS的药物干预研究提供新的视角。     

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.