肠道菌群与肿瘤的相关性

人类肠道中有500余种细菌,参与消化、代谢和免疫等生理活动。肠道菌群因其数量庞大、作用显著,被称为人体的"第二基因"。随着研究的不断深入,发现肠道菌群与多种疾病如心脑血管疾病、糖尿病、肥胖、胃肠炎甚至肿瘤的发生息息相关。恶性肿瘤作为一种病死率极高的疾病,近年来与其相关的研究也越来越丰富。研究者们发现,肠道菌群在肺癌、黑色素瘤、消化道肿瘤和血液系统肿瘤等的发生、发展及治疗中发挥着重要的作用,已成为近年来的研究热点。因此,本文对肠道菌群与各类肿瘤的关系研究进展进行综述。     

溃疡性结肠炎肠道菌群及其代谢产物的研究进展

溃疡性结肠炎(UC)是一种病因尚未阐明的慢性非特异性肠道炎症疾病,多认为由易感人群免疫反应紊乱所致,疾病负担重,严重影响生活质量。近年随着人们生活方式的改变与诊断水平的提升,UC发病率和患病率逐年增加。研究显示肠道菌群及其代谢产物在UC的发生发展过程中起着关键作用,包括调节免疫、参与信号转导、保护肠黏膜屏障和营养代谢等,肠道菌群代谢产物的紊乱及微生态的失衡在炎症的形成及发展、免疫应激及稳态等方面产生重要影响。该文对近年来肠道菌群及其代谢产物与UC关系的相关研究作一综述,并探讨基于肠道菌群以及其代谢产物的UC防治策略。     

肠道菌群在慢性肝脏疾病中作用的研究进展

随着肠-肝轴机制研究的不断深入,肠道菌群与多种慢性肝脏疾病如非酒精性脂肪性肝病、酒精性肝病、肝硬化等相关性研究日益增多。肠道菌群通过肠道菌群失调、物质能量代谢改变及免疫反应激活等机制在多种肝脏疾病发生发展中发挥重要作用。本文对肠道菌群与慢性肝脏疾病关系的研究进展进行综述。     

肠道菌群与肿瘤的免疫治疗

肠道菌群是居住于人体肠道内的正常微生物群体。肠道菌群通常与宿主成共生关系,并与宿主的消化、代谢、免疫调节等生理活动息息相关。靶向作用于免疫检查点的免疫检查点抑制剂,作为肿瘤免疫治疗中的新星,有着逆转肿瘤免疫微环境的作用,为肿瘤治疗提供了新的希望。然而研究发现,有部分人群对免疫检查点抑制剂的治疗无响应,而导致其无响应的最主要的原因是肠道菌群的异常。因此,本文对肠道菌群与肿瘤免疫治疗特别是与免疫检查点抑制剂的研究现状进行综述。     

肠道微生态与非消化系统疾病的研究进展

人体肠道微生态系统是人体微生态系统中最大最复杂的一部分,参与机体代谢、免疫等各方面的生理作用。由于内外源性的病理因素导致肠道微生态的破坏可能会引起人体疾病。随着肠道微生态与消化道疾病研究的不断深入,越来越多的学者开始关注肠道微生态与非消化道疾病的相关性。近年来大量研究表明,肠道微生态与肥胖、神经精神病、皮肤病、心脑血管疾病、消化道外肿瘤、感染性疾病和自身免疫病等非消化系统疾病具有相关性。微生态制剂和粪菌移植可以通过调节肠道微生态平衡参与这类疾病的预防和治疗。肠道微生态系统与消化系统疾病的相关性已被广泛研究和阐述,本文侧重对肠道微生态与非消化系统疾病的研究进展进行综述。     

肠黏膜屏障与肠道菌群的相互关系

摘要：人类肠道中微生物群与肠道环境相互作用以维持机体健康。肠黏膜屏障主要由黏液层、肠道菌群、肠道免疫系统和肠上皮细胞本身的完整性等构成。肠道作为直接与大量菌群接触的器官,其屏障功能在肠道健康中的作用尤为显著。肠道菌群与肠道屏障相互作用,保持肠道菌群与肠道屏障相对稳定,肠道菌群参与肠道免疫反应的建立,共同建立机体天然防御系统,在保持肠道免疫的动态平衡中具有重要作用。当两者之间的平衡被打破时,可诱发功能性胃肠病（如肠易激综合征）及免疫相关性疾病（如炎症性肠病）。本文主要阐述肠黏膜屏障与肠道菌群之间的相互关系以及与肠道屏障功能障碍相关的肠道疾病。     

人体肠道微生态与肝脏免疫关系研究进展

人体微生态学是研究微生物与其宿主相互关系的科学,其中肠道微生态对于人体有最直接的作用。肠道微生态是一个被遗忘的"人体新陈代谢器官",具有维持能量稳态等重要的生理作用。肝脏是人类的重要器官,肝脏中四分之三的血液来自于肠道回流血,其中含有肠道中的细菌产物、环境毒素和食物抗原等。因此肝脏与肠道有最直接的关系。人体肠道微生态中的大量微生物不仅参与调控肠道内的免疫应答,还参与调控肝脏等器官的免疫反应,因此肠道微生态与肝脏免疫密不可分。本文就肠道微生态与肝脏免疫的相关性研究作一综述,以期为人体微生态与肝脏免疫的相关研究提供科学依据。     

轮状病毒的动物感染模型

本文综述了以小鼠和兔为主的动物研究模型对轮状病毒（ＲＶ）感染与免疫的研究。根据感染动物排出病毒、血清学免疫反应等指标,可以间接评价ＲＶ口服疫苗、亚单位疫苗肠道外免疫、粘膜－肠道外联合免疫等对肠道的保护作用以及确定保护作用的相关因素和添加佐剂等新方法的效果。     

肠道菌群失调引起类风湿关节炎发病的研究进展

肠道菌群大多与宿主共生进化,菌群结构、数量恒定形成稳态,能有效预防有害病菌的入侵和炎性疾病的发生。目前多项研究结果显示,肠道菌群失调可能与多种疾病相关联,包括2型糖尿病、肥胖症、肝硬化、结直肠癌和类风湿关节炎。有研究表明,肠道菌群是影响类风湿关节炎(rheumatoid arthritis, RA)发病的环境因素,其中涉及的机制有肠道菌群-黏膜稳态的失衡,其不利于肠道适应性免疫的形成,使得免疫系统不能识别常驻菌与致病菌,引起黏膜紊乱;另一种机制是肠道菌群失调激活免疫因子,引起全身免疫反应。由此可见,肠道菌群参与类风湿关节炎的发生、发展,既有肠道黏膜与菌群的局部调节,也有全身性免疫因子的共同参与。本文主要对肠道菌群失调诱导类风湿关节炎发病的相关性研究予以综述,为进一步研究关节炎早期预防及病因治疗提供理论依据。     

肠道菌群与急性肺损伤/急性呼吸窘迫综合征的关系

肠道和肺部具备相似的黏膜结构、生理功能和免疫功能。胃肠道和呼吸道黏膜菌群紊乱影响肠道疾病和急性肺损伤/急性呼吸窘迫综合征(acute lung injury/acute respiratory distress syndrome,ALI/ARDS)发展和预后。当肠道微生物群失调时会导致肠道炎症的发生,诱发肠道免疫反应并增加肠黏膜上皮的通透性,细菌及炎症因子经肠-肺轴或其他路径引发肺部疾病,致使组织器官缺血缺氧,造成肺部疾病预后不良。本文将重点关注肠道菌群失调与ALI/ARDS的关系,阐述肠道菌群失调引发的肠道和肺部慢性炎症,为肠道菌群失调引发肺部疾病的原因及其内在机制的研究提供新思路,为后续治疗提供新的线索。     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.

     

Identification and Characterization of the First Equine Parainfluenza Virus 5

正Dear Editor,Parainfluenza virus 5 (PIV5), known as canine parainfluenza virus in the veterinary field, is a negative-sense,nonsegmented, single-stranded RNA virus belonging to the Paramyxoviridae family (Chen 2018). The virus was first reported in primary monkey kidney cells in 1954 (Hsiung1972), then it has been frequently discovered in various     

Pathogenic Characterization and Full Length Genome Sequence of a Reassortant Infectious Bursal Disease Virus Newly Isolated in Pakistan

<正>Dear Editor,Infectious bursal disease (IBD) is one of the most important diseases of the poultry. The IBD virus (IBDV), a nonenveloped virus belonging to the Birnaviridae family with a genome consisting of two segments of double-stranded RNA (segments A and B), targets B lymphocytes of bursa of Fabricious leading to immunosuppression. In Pakistan,poultry farming is the second biggest industry and IBD is the second biggest disease threating the poultry sector.However, there is limited genome information of IBDV     

Mink Circovirus Can Infect Minks,Foxes and Raccoon Dogs

正Dear Editor,Mink circovirus (MiCV), which is clustered in the genus Circovirus of the family Circoviridae, was first described in minks from farms in Dalian, China in 2013 (Lian et al.2014). The complete single-stranded circular genome of the virus is 1,753 nucleotides long and contains two major open reading frames (ORFs), designated ORF1 (Rep gene)and ORF2 (Cap gene)(Lian et al. 2014; Ge et al. 2018).Sequence analysis has shown that MiCV is most closely     

CypA Regulates AIP4-Mediated M1 Ubiquitination of Influenza A Virus

Cyclophilin A (CypA) is a peptidyl-prolyl cis/trans isomerase that interacts with the matrix protein (M1) of influenza A virus (IAV) and restricts virus replication by regulating the ubiquitin–proteasome-mediated degradation of M1. However,the mechanism by which CypA regulates M1 ubiquitination remains unknown. In this study, we reported that E3 ubiquitin ligase AIP4 promoted K48-linked ubiquitination of M1 at K102 and K104, and accelerated ubiquitin–proteasome-mediated degradation of M1. The recombinant IAV with mutant M1 (K102 R/K104 R) could not be rescued, suggesting that the ubiquitination of M1 at K102/K104 was essential for IAV replication. Furthermore, CypA inhibited AIP4-mediated M1 ubiquitination by impairing the interaction between AIP4 and M1. More importantly, both the mutations of M1 (K102 R/K104 R) and CypA inhibited the nuclear export of M1, indicating that CypA regulates the cellular localization of M1 via inhibition of AIP4-mediated M1 ubiquitination at K102 and K104, which results in the reduced replication of IAV.Collectively, our findings reveal a novel ubiquitination-based mechanism by which CypA regulates the replication of IAV.