不同配方益生菌在高脂饮食诱导小鼠肥胖发生中的差异化作用

【目的】基于肠道微生物与宿主代谢的相互关系,研究不同配方的益生菌对小鼠肥胖的影响。【方法】50只C57BL/6J雄性小鼠随机平均分成10组,分别给予正常饲料、高脂饲料以及高脂饲料加8种不同配方的益生菌产品(50亿CFU/只),所有动物连续喂养9周,每周测量小鼠体重1次。最后一周测定空腹血糖、葡萄糖耐量试验(glucose tolerance test,GTT)、血脂相关指标,称取内脏重量,并留取小鼠盲肠内容物,提取小鼠肠道菌群总DNA,利用16S rDNA测序检测相关细菌含量。【结果】部分益生菌可引起小鼠体重增速加快,而部分益生菌可减缓小鼠肥胖和降低内脏脂肪重量,同时缓解高血脂症。丹尼斯克品牌益生菌配方组小鼠肠道中厚壁菌/拟杆菌比例(F/B)是正常饮食组的22.8倍,Akkermansia muciniphila(Akkermansia)细菌含量几乎为0;而菌拉丁品牌益生菌配方组小鼠F/B比例与正常饲料饮食组类似,Akkermansia含量为0.5%,为正常饮食对照组小鼠的一半左右。【结论】益生菌可影响小鼠体重和代谢,但不同配方的益生菌效果截然相反。特定的益生菌配方对肥胖和高血脂的改善可能是由于其选用的菌株本身的特性以及菌株之间的相互配比能够降低小鼠肠道中F/B比例以及升高Akkermansia的含量所带来的。此研究为进一步开发可改善代谢的益生菌产品提供了参考。     

基于16S rRNA测序技术分析乳源性复合益生菌对糖尿病小鼠肠道菌群的影响

该研究旨在从肠道菌群角度研究乳源性复合益生菌对db/db糖尿病小鼠的作用机理。将32只db/db糖尿病小鼠分为模型组,阳性药(二甲双胍)组,复合益生菌高、低剂量组,8只db/m鼠作为正常对照组。采用ELISA法测定糖化血红蛋白(glycosylated hemoglobin,type A1C,HbA1c)、血清总胆汁酸(total bile acid,TBA)、血清胰高血糖素样肽1(glucagon-like peptide 1,GLP-1)水平,采用16S rRNA测序技术分析各组小鼠肠道菌群变化情况。结果显示与模型组相比,高、低剂量复合益生菌均能显著降低HbA1c、血清TBA水平,升高血清GLP-1水平;模型组小鼠肠道菌群结构较正常组发生变化,复合益生菌组小鼠肠道菌群结构较模型组发生变化;在菌属水平,模型组Proteobacteria、Enterobacteriaceae等富集,复合益生菌低剂量组norank＿f＿＿Lachnospiraceae、Lachnospiraceae＿UCG-006、Butyricicoccus、Anaerotruncus等富集,复合益生菌高剂量组Esc...     

氯化两面针碱对小鼠溃疡性结肠炎的干预作用及其机制*

目的:探讨氯化两面针碱(NC)通过靶向miR-31对葡聚糖硫酸钠(DSS)诱发小鼠结肠炎的保护作用及其机制。方法:用1%DSS诱发小鼠溃疡性结肠炎(UC)。30只雄性C57BL/6小鼠随机分为正常对照组(Control)(n=7),DSS组(n=8),DSS+NC组(7.27 mg/kg)(n=8)和NC组(n=7),饮水给予DSS,灌胃给予氯化两面针碱。造模周期为3周,分别为Control组和NC组每天饮用无菌水,DSS组和DSS+NC组第一周饮用1% DSS水,第2周正常饮水,第3周1% DSS水。造模最后一周给予Control组和DSS组小鼠0.5% 羧甲基纤维素钠(CMC-Na)灌胃,DSS+NC组和NC组给予NC灌胃。造模完成后,观察小鼠结肠炎相关的疾病活动指数(DAI),HE染色进行结肠组织病理评分,qPCR检测小鼠结肠组织miR-31的表达水平,Western blot检测小鼠结肠组织炎症蛋白NF-κB和COX-2的表达情况。结果:①与DSS组相比,DSS+NC组的 DAI 显著降低(P＜0.01),结肠病理损伤明显改善;②与Control组相比,DSS组小鼠结肠组织miR-31表达显著升高(P＜0.01),DSS+NC组miR-31的表达水平显著低于DSS组(P＜0.05);③与DSS组相比,DSS+NC组中的炎症蛋白NF-κB和COX-2表达水平显著下降(P＜0.05)。结论:氯化两面针碱对DSS诱导的小鼠溃疡性结肠炎有明显的治疗作用,其抗炎机制与下调miR-31的表达有关。     

腹泻犊牛源大肠杆菌对小鼠的致病性

[背景]建立细菌性动物腹泻模型是研究细菌性腹泻机制及抗腹泻药机理的常用方法.[目的]从临床腹泻犊牛粪便中分离出5株不同血清型大肠杆菌(Escherichia coli),经口灌服小鼠建立与临床犊牛腹泻症状近似的小鼠腹泻模型.[方法]72只昆明小鼠随机分为6组,每组12只,分为正常对照组(NC)、E.coli O1干预组...     

降脂益生菌对非酒精性脂肪性肝病小鼠胆汁酸代谢及转运的影响和机制初探

目的 探讨降脂益生菌(鼠李糖乳杆菌DM9054和植物乳杆菌86066联合制剂)对非酒精性脂肪性肝病(nonalcoholic fatty liver disease,NAFLD)小鼠胆汁酸代谢及转运的影响和可能机制.方法 18只雄性FXR-/-小鼠随机分为3组(n=6):正常饮食组、高脂饮食组和高脂饮食+降脂益生菌组....     

携带IL-10基因的双歧杆菌对 感染后肠易激综合征的治疗作用

目的探讨转基因双歧杆菌对感染后肠易激综合征(PI-IBS)小鼠的治疗作用。方法 50只成年雄性SD小鼠,随机选取10只作为空白对照组(NC组),其余40只PI-IBS模型小鼠随机分为IBS组(IBS组)、双歧杆菌治疗组(BL组)、空质粒双歧杆菌治疗组(BL-0组)和BL-hIL-10治疗组(每组10只)。NC组和IBS组每天予0.2mL PBS灌胃1次;其余三组每天灌胃溶有经0.2%L-Arb诱导24h后的BL、BL-0、BL-hIL-10菌液(双歧杆菌浓度达5×108个/mL)的PBS液0.2mL,每天1次。所有小鼠干预7d后处死,然后行血液及结肠组织学检验。结果 (1)通过评估小鼠疾病活动指数、小鼠脾脏指数和结肠组织HE染色病理学变化,证明口服BL-hIL-10能显著减轻PI-IBS小鼠的炎症症状;(2)BL-hIL-10能升高IL-10比例并降低IL-12的比例,维持Th平衡。结论口服转基因双歧杆菌可以缓解PI-IBS小鼠的炎症反应,其机制可能是通过调节Th平衡来实现。     

益生菌干预对高脂高糖饮食诱导肥胖小鼠肠道菌群及脂代谢影响的研究

目的探讨益生菌干预对高脂高糖饮食诱导肥胖小鼠肠道菌群及脂代谢的影响。方法 C57BL/6J雌性小鼠30只随机分为正常对照组、肥胖组和益生菌干预组,每组10只,分别给予标准饲料、高脂高糖饲料以及高脂高糖饲料同时给予益生菌干预,连续喂养6周,测量并分析三组小鼠的体重。留取小鼠粪便样本,应用PCR-DGGE法分析菌群,应用酶反应比色法分析三组小鼠血脂情况。结果与正常对照组小鼠相比,肥胖小鼠体重明显增加,益生菌干预组小鼠体重略有增加;肥胖组小鼠肠道菌群紊乱,与正常对照组分别聚为两大类,益生菌干预组小鼠肠道菌群与正常对照组聚为一大类。肥胖小鼠血清总胆固醇、低密度脂蛋白含量升高,益生菌干预组小鼠较肥胖组血清总胆固醇、低密度脂蛋白含量降低,但与正常对照组仍有差异。结论高脂高糖饮食诱导肥胖小鼠存在肠道菌群结构失调及脂代谢异常,益生菌干预可以改善肥胖小鼠菌群失调以及脂代谢紊乱。     

益生菌对烧伤大鼠肠道膜菌群和sIgA的影响

目的探索益生菌对严重烧伤大鼠早期肠道菌群的调理作用,为防治肠源性感染寻找新途径.方法选用健康Wistar大鼠100只,体重180～220 g,雌雄各半,随机分为:益生菌治疗组(BR),烧伤对照组(BC)和正常对照组(NC),建立30% Ⅲ°烫伤肠源性感染的动物模型,按时分批活杀取材,检测盲肠膜菌群和肠黏膜sIgA的含量.结果 BC组盲肠中双歧杆菌数量与NC组比较,明显减少(P＜0.01),而BR组与NC组比较,差异无显著性(P＞0.05);BC组肠道中酵母菌和大肠埃希菌与NC比较明显增加,BR组差异无显著性;肠粘液sIgA水平与上述指标有类似变化.结论 30%Ⅲ°烫伤大鼠肠道内容物中,双歧杆菌明显下降,大肠埃希菌、酵母菌迅速过生长,导致肠道微生态失衡,应用BR治疗后,促进肠黏膜机械屏障功能的恢复,调理肠道微生态平衡,对肠黏膜起占位性保护作用,提高了肠道局部和全身益生菌免疫的功能.     

银耳多糖对免疫抑制小鼠肠道菌群的保护作用

目的探究银耳多糖(TP)对环磷酰胺(Cy)造成的免疫抑制小鼠肠道菌群的保护作用。方法将18只SPF级雄性Balb/c小鼠随机分为空白对照(NC)组、模型对照(NaCl+Cy)组和银耳多糖恢复(TP+Cy)组,每组6只。NC组小鼠正常饮食饮水,不做任何处理;NaCl+Cy组小鼠每日腹腔注射环磷酰胺0.04 mg/g(以体质量计算,下同)、灌胃生理盐水0.3 mL;TP+Cy组每日腹腔注射环磷酰胺0.04 mg/g、灌胃银耳多糖0.1 mg/g,观察小鼠皮毛、行为、粪便等状态变化。10 d后处死全部小鼠,无菌条件下采集粪便,应用PCR-DGGE技术进行肠道菌群分析;收集脾、结肠等器官,应用苏木精-伊红染色(HE染色)进行脏器损伤分析。结果与NC组小鼠相比,NaCl+Cy组小鼠脾指数、胸腺指数下降;TP+Cy组小鼠脾指数、胸腺指数与NC组差异无统计学意义。PCR-DGGE结果显示,NaCl+Cy组小鼠肠道菌群多样性增加,优势菌群发生变化,疣微菌和紫单胞菌丰富度增加,乳杆菌、普雷沃菌、海洋螺菌、短杆菌和伯克菌丰富度减少;TP+Cy组小鼠肠道菌群多样性和优势菌群与NC组几乎没有差异。HE染色结果显示,NaCl+Cy组小鼠结肠、脾等脏器均有一定的炎症反应,但是TP+Cy组小鼠脏器未见明显损伤。结论银耳多糖对环磷酰胺造成的免疫抑制小鼠的脏器损伤、肠道菌群改变均有一定的保护作用。     

口服益生菌对妊娠期糖尿病小鼠肠道菌群及调节性免疫细胞的影响

目的探讨口服益生菌对妊娠期糖尿病小鼠肠道菌群及调节性免疫细胞的影响。方法 C57BL/6小鼠30只,分为对照妊娠组(正常妊娠小鼠)、妊娠期糖尿病组(妊娠期糖尿病小鼠)和益生菌组(妊娠期糖尿病小鼠每日在食物中添加益生菌),每组10只。妊娠期糖尿病组和益生菌组20只小鼠构建妊娠期糖尿病小鼠模型;ATB半自动微生物检测系统检测粪便中双歧杆菌、大肠埃希菌和乳杆菌的含量;收集小鼠的心脏血,流式细胞术检测CD4~+CD25~+Foxp3~+调节性T细胞(Treg细胞)、CD4~+CXCR5~+Foxp3~+滤泡调节性T细胞(Tfr细胞)和CD19~+IL-10~+调节性B细胞(Breg细胞)在淋巴细胞中的比例;ELISA检测血清中IL-6、肿瘤坏死因子α(TNF-α)、白介素10(IL-10)和转化生长因子-β(TGF-β)的浓度。结果妊娠期糖尿病组小鼠粪便中双歧杆菌、大肠埃希菌和乳杆菌的含量分别为(5.600±0.922 3)、(10.050±0.769 3)和(4.750±0.621 2)LgCFU(每克粪便湿重中菌落形成单位数的对数值),益生菌组分别为(12.770±1.764 0)、(6.667±0.691 2)和(7.367±0.373 9)LgCFU,两组之间差异有统计学意义(t=3.600,P=0.004 9;t=3.271,P=0.008 4;t=3.609,P=0.004 8);妊娠期糖尿病组淋巴细胞中Treg细胞、Tfr细胞和Breg细胞比例分别为(0.032 0±0.005 35)%、(0.338 7±0.045 51)%和(0.058 8±0.015 81)%,益生菌组为(0.185 0±0.064 33)%、(0.600 3±0.083 26)%和(0.118 2±0.012 90)%,两组之间差异有统计学意义(t=2.370,P=0.039 3;t=2.758,P=0.020 2;t=2.907,P=0.015 6);ELISA结果显示妊娠期糖尿病组小鼠血清中IL-6、TNF-α、IL-10和TGF-β浓度分别为(45.33±5.649)、(470.00±50.130)、(3.43±0.541)和(0.33±0.055)ng/mL,益生菌组为(22.33±4.128)、(223.30±41.280)、(9.05±1.953)和(1.35±0.366)ng/mL,两组之间差异有统计学意义(t=3.287,P=0.008 2;t=3.798,P=0.003 5;t=2.771,P=0.019 8;t=2.766,P=0.019 9)。结论调控肠道菌群可促进妊娠期糖尿病小鼠Treg细胞、Tfr细胞和Breg细胞比例增加,减少炎症反应和维持正常妊娠,研究为妊娠期糖尿病的治疗提供了一个新的方法。     

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.