微生态制剂在老年人肠道菌群失衡中的应用

人类从青年到老年这个过程,随着年龄的增长,退行性和感染性疾病的易感性也增加,其可能与人体肠道菌群失衡有着密切的关系。人体肠道内生理菌群对机体健康具有重要的作用,其变化与宿主的免疫功能、食物、疾病和年龄等有关。了解老年人肠道菌群特点,且在老年人肠道菌群失调相关疾病中合理介入微生态制剂,将大大有利于老年人身体健康。本文就老年人肠道菌群失衡相关疾病以及微生态制剂在这些疾病中的应用进行综述。     

质子泵抑制剂对消化道微生态影响的生物学机制

近年来,消化道微生态的相关研究引起广大研究者注意。研究表明质子泵抑制剂(proton pump inhibitors,PPIs)可通过对消化道微生物产生影响,继而引起消化道微生态发生改变。本文分析了PPIs引起消化道微生物变化的相关疾病及原因,发现PPIs通过抑制中性粒细胞的杀菌活性来破坏炎症反应。此外,PPIs抑制胃酸分泌,导致消化道细菌移位、细菌过度生长、肠道通透性增加、肠道蠕动改变和肠道微生物群被破坏,致使肠道黏膜屏障受损和继发性肠道功能失调,由此引起消化道微生态失衡。     

肠道菌群失衡与急性胰腺炎易位感染的关系

目的探讨急性胰腺炎患者肠道菌群与胰腺炎易位感染的关系。方法前瞻性地募集重症急性胰腺炎患者171名,根据是否发生易位感染,分为急性胰腺炎非感染组(131名)和急性胰腺炎易位感染组(40名),所有入选者入院时收集粪便标本和血清,分别采用实时荧光定量PCR和分光光度法测定肠道菌群组成及肠道屏障功能,探讨肠道菌群与胰腺炎肠道屏障以及易位感染的关系。结果急性胰腺炎易位感染组患者入院时肠道菌群中的肠杆菌以及肠球菌含量较非感染组显著增加,实时荧光定量PCR结果发现感染组患者潜在致病菌如肠球菌、肠杆菌显著高于非感染组,与肠道黏膜屏障功能的内毒素水平、二胺氧化酶活性以及D-乳酸含量显著正相关,而双歧杆菌显著低于非感染组,与内毒素水平、二胺氧化酶活性以及D-乳酸含量显著负相关,结果提示肠道菌群失衡可能是急性胰腺炎易位感染发生的主要原因之一。结论肠道菌群失衡是急性胰腺炎易位感染发生的高危因素,与急性胰腺炎易位感染发生相关。     

肝硬化患者肠道菌群失衡的研究现状

肝硬化是我国的一种常见病,近年来越来越多的研究表明肝硬化及其并发症(如门静脉高压、自发性腹膜炎、肝性脑病及肝癌等)都与肠道菌群失衡有着密切的联系。肝脏和肠道通过"肠-肝轴"紧密联系在一起,肝硬化时因小肠细菌过度生长、肠黏膜屏障功能受损、机体免疫功能下降等因素,导致细菌移位、肠道微生态失衡。而肠道微生态失衡又会使肝功能障碍进一步发展,引起肝性脑病等并发症。本文就目前国内外对肝硬化及其并发症与肠道细菌及真菌菌群失衡的研究进行综述。     

肠道微生态与肠道疾病关系的研究进展

正近年来,国内外学者发现,肠道微生态(intestinal microecology)与消化系统疾病、呼吸系统疾病、心脑血管系统疾病、精神疾病、代谢综合征、过敏性疾病、肿瘤等关系密切。本文将综合国内外最新研究进展,对肠道微生态与肠道疾病的关系做一综述。1 肠道微生态的概述肠道微生态是由肠道菌群及其肠道环境构成,肠道菌群包括至少100万亿个细菌,是人体细胞总数的10倍,分属1000多个种,平均重达2 kg。人体肠道菌群按来源分类,可     

肠道菌群与肠黏膜免疫及相关肠道疾病的研究进展

肠道菌群与肠黏膜免疫之间存在密切的关系,二者相互促进、相互影响,共同维持肠道微生态的平衡,二者失衡可造成肠道器质性及功能性的病变。对肠道菌群、肠黏膜免疫及相关肠道疾病的研究进展作一综述。     

益生菌对急性胰腺炎肠道微生态及屏障功能的影响

急性胰腺炎时肠道厌氧菌比例失调,致病菌过度繁殖,肠屏障功能破坏,细菌或毒素易位,是导致继发感染影响其死亡率的主要因素.近年来,有采用益生菌纠正肠道微生态失衡,维持肠道屏障功能和减少内源性感染的初步报道,并取得了较好的疗效.鉴于急性胰腺炎病程长,肠道屏障功能障碍发生率高,应用益生菌作为急性胰腺炎的辅助治疗,已成为临床医师的关注点.     

肠道菌群:运动健康促进的新靶点

肠道菌群与人体通过广泛信息交流形成互惠共生关系。肠道菌群结构稳定性、菌种多样性和微生态平衡性使其成为人体更易接触和调控的"生理中心",深刻影响人体健康。适宜运动可通过优化肠道菌群,促进宿主肠道微生态健康。以肠道菌群为靶点的运动健康促进研究,为运动与人体健康和疾病研究呈现出新领域。基于宏基因组学、宏转录组学等微生态研究技术,揭示与人体疾病相关的肠道菌群失调,鉴定出疾病相关的特定菌群种类及功能,使得以肠道菌群为靶点的运动精准干预人体健康成为可能。     

益生菌在结直肠癌患者中的应用

结直肠癌(colorectal cancer,CRC)的发病率及病死率在多国多年居高不下,肠道微生态的失衡在CRC的发生发展中所起的作用被许多学者所证实。专家一致认为,积极纠正肠道微生态失衡是可取的。CRC患者术前肠道菌群已经出现改变,术后肠道菌群失衡加重,化疗会进一步加重这种失衡状态。肠道微生态的稳态对机体肠道功能和免疫功能等起着重要作用。益生菌作为一种可调节肠道菌群的微生态制剂,已显现出在CRC患者治疗中的应用价值,现对益生菌在CRC患者中的应用进展作一综述。     

肝硬化自发性腹膜炎患者肠道优势菌群分析初探

目的 探讨肝硬化自发性腹膜炎(SBP)患者肠道优势菌群多样性变化的规律.方法 采集肝硬化SBP初始诊治患者和健康受试者各30例,收集粪便样本,进行PCR-DGGE优势菌群结构分析,并应用定量PCR技术检测肠道内乳杆菌属、双歧杆菌属和肠杆菌科细菌的含量.结果 肝硬化SBP患者肠道优势菌群结构复杂程度明显增多,SBP组和健康对照组患者分别能够聚类到不同的簇中,提示两组受试者肠道优势菌群结构明显不同.定量PCR检测结果发现,肠道优势细菌中双歧杆菌的含量明显下降(7.90±0.96 vs.9.15±1.21),而肠杆菌科细菌的数量明显增多(8.95 ±0.88 vs.7.31±0.40),两组间比较差异具有统计学意义(P＜0.05),这与SBP常见的病原菌有一定的相关性.结论 肝硬化SBP患者肠道优势菌群结构明显变化,双歧杆菌属细菌明显减少,肠杆菌科细菌明显增加,肠道微生态失衡可能是SBP发生的内在原因.     

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.     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8⁺ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8⁺ T cells are involved in the pathogenesis of RE.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.