卷曲乳杆菌对三种结肠上皮细胞的粘附性

目的研究卷曲乳杆菌对3种结肠上皮细胞(SW480细胞、SW620细胞、LOVO细胞)的粘附性。方法将处于对数生长期的卷曲乳杆菌A7分别与SW480细胞、SW620细胞、LOVO细胞进行体外粘附试验,革兰染色后显微镜观察卷曲乳杆菌A7对3种结肠上皮细胞的粘附结果并计数。结果卷曲乳杆菌A7对3种结肠上皮细胞的粘附均具有显著性,其中对于SW480细胞和LOVO细胞的粘附性明显高于SW620细胞。结论卷曲乳杆菌A7对SW480细胞、SW620细胞、LOVO细胞均具有较强的粘附性,提示该菌株有望成为肠道益生菌的新成员。     

多糖类益生元的筛选及凝结芽孢杆菌体外发酵特性北大核心

【目的】探究9种多糖对凝结芽孢杆菌(Bacillus coagulans)的增殖、产酶特性的影响。【方法】将凝结芽孢杆菌分别添加至菊粉多糖(inulin polysaccharide)、刺五加多糖(Eleutherococcus senticosus polysaccharide)、壳寡糖(chitosan oligosaccharide)、防风多糖(Saposhnikovia divaricata polysaccharide)、低聚木糖(xylo-oligosaccharide)、黄芪多糖(Astragalus polysaccharide)、甘露糖(D-mannose)、白术多糖(Atractylodes macrocephala Koidz polysaccharide)和玉屏风多糖(Yu Ping Feng polysaccharide)为唯一碳源的培养基中,通过菌株生长、酶活性及其体外厌氧发酵等作为指标,筛选出最优益生元。【结果】凝结芽孢杆菌能很好地利用防风多糖、黄芪多糖、白术多糖和玉屏风多糖;添加量为4%的防风多糖和白术多糖,pH差值差异最大,蛋白酶活性差异显著(P<0.05)。体外发酵乳酸活性和总蛋白酶活性均提高,4%白术多糖的乳酸和总蛋白酶活性差异显著(P<0.05);肠道内容物发酵液16S rRNA基因高通量测序结果表明,与对照组比较,添加黄芪多糖、防风多糖、甘露糖3种益生元发酵凝结芽孢杆菌显著降低了气单胞菌(Aeromonas)、α-变形菌(α-Proteobacteria)、链球菌(Streptococcus)、志贺氏杆菌属(Shigella)等致病菌的相对丰度,提高了乳杆菌(Lactobacillus)、厚壁菌门(Firmicutes)、乳酸乳球菌(Lactococcus lactis)、产酸杆菌(Acidobacteria)的相对丰度。【结论】凝结芽孢杆菌发酵4%白术多糖具有较好的产酶性能与益生特性,二者协同发酵添加至饲料中具有较好的发展潜力。     

几丁聚糖对双歧杆菌体外生长的影响

目的观察几丁聚糖对双歧杆菌是否有增菌作用。方法应用分光光度比色法分析几丁聚糖对双歧杆菌体外生长作用的影响,并与中药黄芪对该菌的作用进行比较。结果与对照组比较,几丁聚糖和黄芪浓度分别为2.5 mg/mL和62.5 mg/mL时,对双歧杆菌有明显的增殖作用（P〈0.05）。比较两种药物在该浓度时对双歧杆菌的生长作用,虽然黄芪的增殖作用高于几丁聚糖,但差异无统计学意义（P〉0.05）。结论 2.5 mg/mL剂量的几丁聚糖体外能够促进双歧杆菌的生长。     

两种乳酸菌胞外多糖对人体粪便菌群的影响

目的 在体外利用7名志愿者的新鲜粪便作为来源,选择菊粉作为对照,研究干酪乳杆菌LC2W与鼠李糖乳杆菌Y37胞外多糖对人体肠道菌群的影响.方法 利用PCR-DGGE(变性梯度凝胶电泳)方法分析样品中菌群组成,高效液相色谱分析培养前后胞外多糖组分变化.结果 与菊粉相比,粪便菌群在添加乳杆菌胞外多糖培养后,Parabacteroides类群细菌明显增加,4名志愿者粪便样品中出现明显的双歧杆菌条带,两种乳杆菌胞外多糖对粪便菌群的影响差异无统计学意义;而添加菊粉培养后,Bacteroides类群细菌的条带明显增加.两种乳杆菌胞外多糖中主要是大分子量的部分被利用.结论 干酪乳杆菌LC2W与鼠李糖乳杆菌Y37的胞外多糖在体外有调节粪便菌群的作用.     

乳杆菌胞外多糖对人体粪便菌群及其产生短链脂肪酸的影响

目的在体外利用7名志愿者的新鲜粪便作为来源,选择菊粉作为对照,研究干酪乳杆菌LC2W与鼠李糖乳杆菌Y37胞外多糖对人体肠道菌群的影响。方法利用PCR-DGGE(变性梯度凝胶电泳)方法分析样品中菌群组成,采用高效液相色谱的方法分析短链脂肪酸组成。结果与菊粉相比,粪便菌群在添加乳杆菌胞外多糖培养后,可以促进短链脂肪酸的生成,保持肠道菌群的多样性。结论干酪乳杆菌LC2W与鼠李糖乳杆菌Y37的胞外多糖在体外有调节粪便菌群的作用。     

黄芪多糖对三硝基苯磺酸诱导溃疡性结肠炎大鼠的保护作用

本研究探讨黄芪多糖(APS)对2,4,6-三硝基苯磺酸(TNBS)诱导溃疡性结肠炎(UC)大鼠的保护作用。将72只SD大鼠随机分为正常组、模型组、柳氮磺胺吡啶(SASP)阳性组、APS低、中、高剂量组(100、200、400mg·kg-1),每组12只,除正常组外,每组以150mg·kg-1 TNBS乙醇溶液灌肠制备大鼠结肠炎模型。造模24h后,SASP阳性组及黄芪多糖组分别给予相应的药物进行灌胃干预,每日1次,连续给药14d。研究过程中观察大鼠体重、评价其活动指数(DAI)及结肠黏膜损伤(CMDI),并于给药结束后检测大鼠血清和组织中的炎症因子及生化指标。结果表明,黄芪多糖可以显著改善UC大鼠活动指数,减轻大鼠黏膜损伤,且APS高剂量组大鼠组织中丙二醛(MDA)、髓过氧化物酶(MPO)水平相比模型对照组显著降低,超氧化物歧化酶(SOD)水平显著增加(p<0.05);同时血清中炎症因子TNF-α、IL-6含量相比模型对照组显著降低,IL-10含量显著增加(p<0.05)。因此,黄芪多糖对TNBS诱导的大鼠溃疡性结肠炎具有一定的保护作用。     

黄芪多糖与枸杞多糖联用对小鼠肝组织损伤的保护作用

探究黄芪多糖与枸杞多糖对四氯化碳(CCl_4)所致小鼠急性肝损伤的协同保护作用。采用CCl_4诱导小鼠急性肝损伤,动物处死后取血液测定血清中谷丙转氨酶(ALT)、谷草转氨酶(AST)活性,取肝脏计算肝指数并制备肝匀浆测定其中谷胱甘肽(GSH)活力、丙二醛(MDA)含量,并对小鼠肝脏进行组织切片观察,评价黄芪多糖与枸杞多糖联用对小鼠肝组织的保护效果。实验显示,黄芪多糖与枸杞多糖各配比(LBP 50 mg/kg+APS 100,LBP 70 mg/kg+APS 400,LBP 350 mg/kg+APS 800)均能显著抑制CCl_4急性肝损伤所引起的MDA含量、肝脏指数、ALT和AST活性的升高(p0.05),有效地提高肝脏中GSH的含量,减轻小鼠的肝组织损伤程度。本研究表明黄芪多糖与枸杞多糖联用对CCl_4诱导的小鼠急性肝损伤有明显的保护作用。     

发酵麸皮多糖酶辅助提取工艺优化及其生物活性研究

通过响应面法优化提取发酵麸皮多糖的工艺,并评价其体外益生和抗氧化活性。以发酵麸皮多糖的得率为响应值,采用纤维素酶酶解与水浴浸提相结合的方法提取发酵麸皮多糖,以纤维素酶添加量、料液比、水浴浸提温度、水浴浸提时间为试验因素建立数学模型,筛选最佳提取工艺条件。通过测定还原力、DPPH和·OH自由基的清除能力对比发酵和未发酵麸皮多糖的体外抗氧化活性,并通过测定嗜酸乳杆菌、植物乳杆菌、两歧双歧杆菌的生长对比发酵和未发酵麸皮多糖的体外益生活性。结果表明,发酵麸皮多糖最佳提取工艺为:料液比1∶16(w/v),酶添加量1 000 U/g,水浴浸提温度90℃,水浴浸提时间60 min,在此条件下发酵麸皮多糖的得率实测值为73. 35%。发酵麸皮多糖具有较强的DPPH和·OH自由基的清除能力,可促进嗜酸乳杆菌、植物乳杆菌和两歧双歧杆菌的生长。     

阴道中益生特性乳杆菌的分离与功能评价

目的分离健康女性阴道中的乳杆菌并鉴定其益生特性,为开发治疗妇科疾病的复方益生菌制剂提供新型菌株。方法采集健康女性阴道分泌物并分离筛选乳杆菌,通过16SrDNA序列分析鉴定乳杆菌分离株,并对其产酸性能、产H2O2能力、抑菌能力、产生物膜能力进行检测。结果从50名健康女性阴道内共分离出179株乳杆菌,其中卷曲乳杆菌101株、詹氏乳杆菌42株、格氏乳杆菌26株、植物乳杆菌5株、唾液乳杆菌3株以及干酪乳杆菌2株。179株乳杆菌中有146株具有产酸能力,发酵液pH值的最低的5株菌分别为卷曲乳杆菌J3、卷曲乳杆菌J8、詹氏乳杆菌J87,植物乳杆菌J75以及格氏乳杆菌J35,其pH分别为4.20、4.23、4.24、4.26及4.36;产H2O2弱阳性菌株有87株、阳性有37株、强阳性有9株,这9株菌分别为卷曲乳杆菌J3、卷曲乳杆菌J8、卷曲乳杆菌J20、詹氏乳杆菌J87,詹氏乳杆菌J90、詹氏乳杆菌J15、格氏乳杆菌J11、植物乳杆菌J75、植物乳杆菌J69以及植物乳杆菌J40;能拮抗大肠埃希菌的菌株有115株、拮抗金黄色葡萄球菌的有84株、拮抗白假丝酵母的有52株;经统计,对三者同时有拮抗作用且作用最强的只有6株,分别为卷曲乳杆菌J3、卷曲乳杆菌J50、卷曲乳杆菌J62、詹氏乳杆菌J87、詹氏乳杆菌J16和格氏乳杆菌J66;不同乳杆菌产生物膜能力数值范围在1.0~5.4,卷曲乳杆菌、詹氏乳杆菌、干酪乳杆菌的生物被膜形成能力显著高于其他三种菌(P0.05)。在全部179株菌中,卷曲乳杆菌J3和詹氏乳杆菌J87既具有强的产酸能力和产过氧化氢能力,又有较强抑菌活性,同时产生物膜能力也最强。结论卷曲乳杆菌J3和詹氏乳杆菌J87具有优良的生物学特性,有望成为用于治疗妇科疾病微生态制剂的备选菌株。     

黄芪多糖抗小鼠疲劳的作用机制研究

目的:探讨黄芪多糖对小鼠的抗疲劳作用及机制。方法:该研究分为实验组和对照组两组,实验组设置三组剂量0.2,0.05,0.0125 g/kg对小鼠连续灌胃28天,对照组给予蒸馏水灌胃,进行负重游泳试验计算游泳力竭时间,并检测小鼠全血中血糖,血中乳酸含量,肝脏超氧化物歧化酶(SOD)、丙二醛(MDA)、乳酸脱氢酶(LDH)含量及肌组织中糖原储备量。结果:1).与对照组相比较,黄芪多糖低剂量、高剂量组小鼠负重游泳时力竭时间明显延长;2).中剂量组小鼠运动后肝脏SOD活力值比对照组明显增高,高剂量组肌糖原的储存量明显升高,而低剂量组乳酸明显降低。结论:黄芪多糖具有抗疲劳作用,可能通过增加抗氧化酶类SOD活性、减少乳酸的产生及增加肌糖原能量储存等途径起作用。     

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.