水苏糖及其功能的研究进展

随着现代社会的发展,人们对健康的要求日益增高,对生活质量也有了很高的要求.与此同时,健康食品也成为了现代社会的一个热潮,受到社会的广泛关注.水苏糖是唇形科水苏属植物中天然存在的能显著促进人体肠道有益菌群增值的功能性低聚糖,被誉为"天然超强双歧因子"[1].被美国FAD认定为GRAS(一般安全无毒食品)的低聚糖产品.上世纪80年代开始,日本人就开始研究水苏糖的功能.水苏糖与其他功能性低聚糖相类似,它不为人体肠胃消化液所分解,能被人体肠道内的双歧杆菌、乳酸杆菌等有益菌群所利用,促进这些有益菌的增值[2].此外,水苏糖还能抑制腐败菌,如大肠埃希菌和产气荚膜梭菌的生长,从而抑制腐败菌代谢所产生的酚、氨、吲哚等有害物质.且根据食品安全性毒理学评价程序和方法( GBl5193-2003)中急性毒性分级标准判定,水苏糖属实际无毒级[3].本文就水苏糖对肠道菌群的影响以及其产生的作用进行综述.     

几种益生元制剂对肠道菌群作用效果的研究

目的探讨几种益生元制剂对肠道菌群作用效果。方法通过体外实验和体内试验。结果低聚果糖、水苏糖、低聚木糖、低聚异麦芽糖均能促进双歧杆菌和乳杆菌的增殖,并能够酸化肠道的pH;能够显著提高肠道的B／E值（肠道内双歧杆菌和肠杆菌数量log值的比值）,增加肠道中有益菌的比例,有益于稳定肠道的微生态平衡。结论这几种益生元制剂对肠道菌群有较好的调节作用。     

中药提取物水苏糖对实验性肝硬化大鼠血浆内毒素及肠道菌群的影响

目的探讨中药提取物水苏糖对肝硬化大鼠血浆内毒素及肠道菌群的影响.方法36只SD大鼠随机分为正常对照组（n=6）,模型组,预防组,晚期治疗组.采用CCL4复合因素法建立肝硬化模型;实验第9周末处死所有大鼠,观察药物对肝硬化大鼠内毒素,肠道菌群,AST、ALT肝功能及肝组织病理学等的影响.结果中药提取物水苏糖对内毒素及其它指标都有明显的改善,预防组,晚期治疗组病理都有改善,预防组优于治疗组.结论中药提取物水苏糖能有效调整肝硬化肠道菌群失调,并降低血浆内毒素.对肝脏有保护作用.     

天然多糖对肠道菌群调节作用的研究进展

综述了天然多糖对肠道菌群调节作用的研究现状,为天然多糖对肠道菌群调节的深入研究提供科学依据。     

长康双歧菌增殖胶囊对肠道菌群影响的研究

目的 研究以苏糖为主要功能组分的长康双歧菌增殖胶囊的特性及功效。方法 通过实验鼠及志愿者进行调节肠道菌群试验,观察该微生态制剂的作用。结果 小鼠肠道内双歧杆菌数量明显增加;受试人群肠道内肠杆菌、拟杆菌数量明显减少,肠球菌、乳酸杆菌、双歧杆菌数量明显增加,产气莱膜梭菌数量增加。结论 以水苏糖为主要功能组分的长康双歧菌增殖胶囊具有调节肠道菌群、改善肠道内环境的功能。     

孕妇肠道菌群与婴幼儿肠道菌群及肥胖的关系研究进展

女性妊娠过程中,身体的生殖、消化、内分泌等系统会发生一系列变化,孕妇的肠道菌群也会发生相应变化。母亲肠道菌群与子代肠道菌群密切相关,婴幼儿生命早期肠道菌群的来源主要有母亲肠道菌群、母亲阴道菌群和母亲体表菌群,出生以后婴幼儿肠道菌群的定殖主要受喂养方式、生活环境、抗生素暴露等因素的影响。此外,人体肠道菌群功能强大,其可通过调节人体营养物质吸收和外周器官的代谢而成为影响肥胖的一种重要的内环境因素。综述孕妇妊娠期间包括孕早期、孕中期、孕晚期肠道菌群的变化和影响婴幼儿肠道菌群定殖的主要因素,以及对子代肥胖的影响,以期为临床医务人员对预防和控制婴幼儿肥胖提供参考。     

肠道菌群功能与影响因素研究进展

人体肠道作为一种营养丰富的天然环境有多达100兆个微生物,其中绝大多数存于结肠内,密度接近1011~1012/m L。人类肠道内的微生物多样性是微生物菌落和宿主共同进化的结果,自然选择和进化使肠道菌群与宿主处于一种动态平衡且稳定的关系。文章综述了肠道菌群对宿主可能产生的影响以及引起肠道菌群发生改变的某些因素,肠道微生物影响宿主的代谢、营养吸收、免疫功能以及神经功能调节,而饮食及其他条件又能引起肠道菌群的改变。深入分析肠道菌群的具体结构、探索不同微生物在宿主体内究竟发挥着怎样的作用以及如何充分利用微生物的不同特性改善人类健康应成为今后研究的重点方向。     

蜜蜂肠道菌群结构功能研究进展

在长期的共同进化中,肠道菌群与其宿主形成了紧密的联系,为宿主提供了许多有益的作用。作为一种社会性昆虫,蜜蜂的生活习性为其肠道菌群提供了良好而稳定的传播途径,因此,蜜蜂与其肠道菌群形成了一种紧密的互惠互利共生关系。近年来,随着对蜜蜂肠道菌群了解的不断加深,对蜜蜂肠道菌群功能的研究也不断深入,大量研究表明蜜蜂的肠道菌群在宿主食物的消化代谢、宿主免疫的激活和抵抗致病菌、调节宿主生理等方面都有着重要的作用,同时破坏肠道菌群的稳定对蜜蜂的健康有着明显的负面影响。本文对近年来西方蜜蜂肠道菌群功能研究进行了总结,旨在为进一步深入探索蜜蜂肠道菌群与其宿主的相互作用及在养蜂生产上应用肠道菌群防控疾病提供参考。     

运动与肠道菌群的相关性

肠道菌群与人体互相依存,与机体的感染、营养、免疫及代谢密不可分,在某些疾病的预防和治疗中有着非常重要的作用。肠道菌群具有易变性,它的种类和数量是由遗传和环境因素共同决定的,环境因素主要包括宿主健康状态和生活方式等。近来发现,生活方式与代谢性疾病的发生发展密切相关,而这些代谢性疾病的发生发展都与肠道菌群的改变有关。本研究就机体不同代谢状态下肠道菌群的变化以及运动这种生活方式直接对肠道菌群的影响进行综述。     

天然药物通过重构肠道菌群减少动脉粥样硬化风险的研究进展

动脉粥样硬化(atherosclerosis,AS)是冠心病(coronary atherosclerotic heart disease,CAD)的发病基础。参与AS形成的原因有很多,近年来的研究表明依赖肠道菌群的胆碱代谢物氧化三甲胺(trimethylamine oxide,TMAO)也与AS的发生、发展有关。天然药物具有生物多效性,有研究表明其中的多酚类成分可通过影响肠道菌群的多样性减少AS的风险。本文就天然药物与肠道菌群和AS关系的研究进展进行综述。     

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.