新疆昆仑雪菊水提物对 小鼠肠道菌群的调节作用

目的 研究新疆昆仑雪菊水提物对小鼠肠道菌群的影响。方法 C57BL/6小鼠,雄性,8周龄,40只,分为4个组(每组10只):高、中、低三个剂量组和空白对照组,给药14 d,收集给药前后小鼠粪样,16S rDNA实时荧光定量PCR法测定粪样中肠杆菌、肠球菌、乳杆菌和产气荚膜梭菌水平。结果 与空白对照组比较,中剂量组小鼠肠道粪样中乳杆菌显著增多(t=-2.503,P0.05),低剂量组与高剂量组变化不显著;与空白对照组比较,其他组小鼠肠道中肠杆菌属、肠球菌属和产气荚膜梭菌水平均无显著变化。结论 参照《保健食品检验与评价技术规范—2003版》之"调节肠道菌群作用检验方法",新疆昆仑雪菊水提物对小鼠肠道菌群具有一定的调节作用。     

鲍鱼内脏酶解物可调节肠道菌群及短链脂肪酸缓解小鼠系统低度炎症

为探究鲍鱼内脏酶解物对辣椒素诱导的系统低度炎症模型小鼠炎性因子、肠道菌群及短链脂肪酸的影响,将30只雄性小鼠随机分为6组：空白对照组、辣椒素致炎模型组、鱼油对照组、鲍鱼内脏酶解物低、中、高剂量组（0.30、0.60、1.20 g /(kg·d)）,干预7 d后,ELISA法检测小鼠血清中肿瘤坏死因子-α（TNF-α）、白细胞介素-1β（IL-1β）、白细胞介素-6（IL-6）、白细胞介素-10（IL-10）,鲎试剂法测定小鼠血清中细菌脂多糖（LPS）的含量,16S rRNA基因高通量测序和生物信息学方法考察小鼠肠道菌群的结构组成,GC-MS法测定小鼠粪便中短链脂肪酸的含量。结果显示,辣椒素模型组小鼠血清中TNF-α、IL-6和LPS含量显著升高,肠道菌群OTUs数显著降低,菌群各门、属水平比例存在显著变化,其中寡养单胞菌属（Stenotrophomonas）和棒状杆菌属(Corynebactrium)等有害相对丰度显著增加,粪便中的乙酸、丙酸以及总短链脂肪酸含量显著降低,异戊酸含量显著升高,而经鲍鱼内脏酶解物干预后,小鼠血清中IL-1β、IL-6和LPS含量显著降低,肠道中乳杆菌属（Lacbobacillus）、阿洛巴氏菌属(Allobaculum)、拟杆菌属(Bacteroides)和瘤胃球菌属(Ruminococcus)等短链脂肪酸产生相关细菌的相对丰度显著增加,寡养单胞菌属和棒状杆菌属相对丰度显著降低,乙酸、丙酸和总短链脂肪酸的含量显著升高,异戊酸含量显著降低。鲍鱼内脏酶解物可以调节肠道菌群结构和肠道短链脂肪酸组成缓解机体系统低度炎症反应。     

三联益生菌对便秘小鼠肠道推进功能改善及其对 小鼠肠道菌群调节作用的研究

目的研究新型嗜酸乳杆菌NCFM-乳双歧杆菌Bi-07-鼠李糖乳杆菌NH001三联益生菌制剂对便秘小鼠小肠蠕动的促进作用,以及其对小鼠肠道菌群构成比例的调节作用。方法小肠推进率实验:将50只KM小鼠适应性饲养后随机分为空白对照组、模型对照组和低中高三个剂量组。空白对照组和模型对照组给予蒸馏水,低中高剂量组每天分别给予0.165、0.330、0.990g/(kg·bw)益生菌制剂,灌胃14d后使用复方地芬诺酯建立小鼠便秘模型观察小肠墨汁推进率;肠道菌群调节作用实验:将42只BALB/c小鼠中随机抽取10只作为自身对比空白组,适应性饲养后将所有小鼠随机分为空白对照组和低中高三个剂量组,空白对照组给予蒸馏水,各剂量组以相同剂量给予益生菌制剂灌胃。自身对比空白组于灌胃前无菌采集小鼠直肠粪便,所有小鼠灌胃30d后无菌采集直肠粪便,使用16SrDNA基因测序对粪便中菌群DNA进行多样性及各水平菌群物种测定。结果高剂量组便秘小鼠小肠推进率显著高于模型对照组(P0.05);各剂量组肠道菌群多样性、双歧杆菌属、乳杆菌属数量较灌胃前显著增加(P0.05),大肠埃希菌属、梭菌属、肠球菌属较灌胃前显著降低(P0.05)。结论三联益生菌能够有效促进便秘小鼠肠道蠕动能力,改善便秘症状;同时对小鼠肠道菌群结构有调节作用。     

基于气相色谱法分析T2DM患者粪便中SCFAs水平与HbA1c的相关性

目的研究2型糖尿病患者粪便中6种短链脂肪酸水平与糖化血红蛋白的相关性。方法采用气相色谱法检测粪便中短链脂肪酸的含量,并对方法学进行考察。选取2018年在本院查体的2型糖尿病患者57例,根据糖化血红蛋白水平将其分为高糖化组(糖化血红蛋白7.0,28例)与低糖化组(糖化血红蛋白≤7.0,29例)。应用气相色谱法检测两组患者粪便中6种短链脂肪酸水平,并分析6种短链脂肪酸水平与糖化血红蛋白的相关性。结果低糖化组患者粪便中乙酸、丙酸、丁酸、戊酸水平显著高于高糖化组(均P0.05),异丁酸与异戊酸水平差异无统计学意义(均P0.05)。Pearson相关性分析结果表明:在2型糖尿病患者中,糖化血红蛋白与粪便中乙酸呈负相关(r=-0.540 1,P0.000 1),与丙酸呈负相关(r=-0.358 1,P=0.006 2),与丁酸呈负相关(r=-0.421 7,P=0.001 1),与戊酸呈负相关(r=-0.326 8,P=0.042 3),与异丁酸、异戊酸无相关性。结论 2型糖尿病患者粪便中短链脂肪酸水平与糖化血红蛋白存在一定的相关性,短链脂肪酸水平的下降可能是影响血糖控制不佳的主要原因。     

长短链菊粉对抗生素诱导肠道菌群紊乱小鼠调节作用的研究

目的采用头孢曲松钠诱发小鼠肠道菌群紊乱建立模型,观察不同剂量长短链菊粉对抗生素诱导的肠道菌群紊乱小鼠的调节作用。方法 2g/(kg·d)头孢曲松钠灌胃小鼠,连续8d,诱导小鼠肠道菌群紊乱,然后将菌群紊乱小鼠分为低剂量短链菊粉处理组、高剂量短链菊粉处理组、低剂量长链菊粉处理组、高剂量长链菊粉处理组和自然恢复组,连续处理2周,采用PCR-DGGE和菌落计数的方法观察各组小鼠肠道菌群的恢复情况。结果抗生素处理后,小鼠肠道菌群与正常小鼠相比具有显著差异,菌群条带数明显减少(P0.05),有益菌肠杆菌、乳酸杆菌、双歧杆菌和消化球菌含量明显减少(P0.05),条件致病菌葡萄球菌和铜绿假单胞菌含量明显增多(P0.05);经菊粉处理后,小鼠的肠道菌群恢复效果明显好于自然恢复组(P0.05),其中长链菊粉处理组优于短链菊粉处理组,且高剂量长链菌粉处理组恢复程度优于低剂量长链处理组。结论菊粉能够有效调节抗生素引起的肠道菌群紊乱,而长链菊粉的调节作用优于短链菊粉,且高剂量更有效。     

小鼠肠道菌群代谢产物与糖尿病的相关性研究

目的研究糖尿病小鼠粪便中肠道菌群代谢产物与血糖之间的相关性,探讨肠道菌群与糖尿病之间的关系。方法采用高脂饮料喂养加腹腔注射链脲佐菌素(STZ)的方法建立糖尿病小鼠模型;将实验动物随机分为正常组、高脂组、糖尿病组及模型给药组,连续给药5周后,采血测血糖血脂,同步收集动物粪便,测粪便中短链脂肪酸(Short-chain fatty acids,SCFA)及D-乳酸。SCFA的检测使用气相色谱法,D-乳酸的检测使用紫外酶促法。结果糖尿病组小鼠粪便中乙酸、丙酸和正丁酸含量明显低于正常组及高脂组(P<0.01),D-乳酸含量明显高于正常组及高脂组(P<0.01);给药组乙酸、丙酸和正丁酸含量明显高于糖尿病组(P<0.01),D-乳酸含量明显低于糖尿病组(P<0.01)。给药组丙酸、正丁酸的含量与正常组间差异无统计学意义(P>0.05),但乙酸的含量仍低于正常组(P<0.01),D-乳酸的含量仍高于正常组(P<0.01)。结论糖尿病小鼠粪便中的肠道菌群代谢产物与血糖之间存在着密切的关系,代谢产物的差异性,提示肠道菌群的差异性,反映出糖尿病小鼠存在肠道菌群紊乱。     

维吾尔族新发2型糖尿病患者肠道 乳杆菌属和多形拟杆菌的定量研究

目的定量研究维吾尔族新发2型糖尿病(T2DM)患者和糖耐量正常(NGT)人群肠道中乳杆菌属(Lactobacillus genus)和多形拟杆菌(Bacteroides thetaiotaomicron)的相对水平。方法严格按照纳入标准、排除标准收集维吾尔族新发T2DM患者96例,NGT 98例。提取所有研究对象的粪便细菌总DNA后,采用16SrDNA基因实时荧光定量PCR(Real-time PCR)对乳杆菌属和多形拟杆菌的水平进行定量检测;运用Pearson相关性分析乳杆菌属与研究对象的BMI、腰围、臀围、收缩压(SBP)、舒张压(DBP)、空腹血糖(FBG)、甘油三酯(TG)、总胆固醇(TC)、高密度脂蛋白(HDL-C)和低密度脂蛋白(LDL-C)的相关性。结果 16SrDNA基因Real-time PCR结果显示:(1)与新疆维吾尔族NGT组相比,乳杆菌属水平在新发T2DM中较低,差异有统计学意义(t=8.557,P=0.000)。但是多形拟杆菌在两组差异无统计学意义(t=0.524,P=0.601);(2)新疆维吾尔族上述人群肠道中乳杆菌属水平与FBG呈负相关(r=-0.334,P=0.000),腰围呈负相关(r=-0.170,P=0.018),TC呈负相关(r=-0.178,P=0.013),TG呈负相关(r=-0.157,P=0.030),收缩压呈负相关(r=-0.255,P=0.000)。结论 Lactobacillus genus水平在肠道中降低可能与2型糖尿病的发病,血糖和血脂代谢有关,其机制需进一步研究探讨。     

采用高通量测序技术 研究抗生素对小鼠肠道菌群的影响

目的探讨不同浓度抗生素对小鼠肠道菌群多样性和结构的影响,并预测相关功能变化。方法 15只SPF级ICR小鼠随机分为正常组、低浓度抗生素组和高浓度抗生素组,连续灌胃5 d后,采集小鼠新鲜粪便样本。利用Illumina MiSeq测序平台,对细菌的16S rRNA V3-V4区进行高通量测序,并对测序的结果进行生物信息学分析。结果高、低浓度抗生素组小鼠肠道菌群组成与正常组存在明显差异。与正常组相比,高剂量组小鼠肠道肠球菌属、志贺埃希菌属相对丰度显著升高(t=-2.71,P=0.026;t=-2.30,P0.05);分节丝状菌属、拟普雷沃菌属相对丰度显著降低(t=2.88,P=0.020;t=2.49,P=0.037),理研菌属极显著降低(t=3.79,P=0.005)。低剂量组小鼠肠道菌群变形菌纲成为优势菌,芽胞杆菌属、粪球菌_2、苏黎世杆菌属、普雷沃菌属_2、普雷沃菌属_7、志贺埃希菌属、沙雷菌属和放线菌属等相对丰度显著升高(均P0.05);梭杆菌属、泛菌属极显著升高(t=-3.19,P=0.013;t=-3.50,P=0.008);分节丝状菌属、理研菌属相对丰度显著降低(t=2.69,P=0.028;t=2.33,P=0.048)。PICRUSt功能预测分析显示,抗生素组显著增加人类疾病、细胞过程和环境信息处理功能层的基因拷贝数,显著降低有机系统、遗传信息处理和代谢功能层的基因拷贝数。结论广谱抗生素能破坏小鼠肠道的微生态平衡,有必要深入研究抗生素对心血管、免疫性、感染性及神经退行性疾病发展的潜在作用。     

两色金鸡菊醇提物对2型糖尿病小鼠肠道菌群的影响

目的探讨两色金鸡菊醇提物,肠道菌群和2型糖尿病(T2DM)之间的可能联系。方法收集模型组(A),两色金鸡菊醇提物高剂量组1.8 g/kg(B),两色金鸡菊醇提物中剂量组1.2 g/kg(C),二甲双胍对照组0.2 g/kg(D),空白对照组(E)粪便样本,采用16S r DNA实时荧光定量PCR技术检测粪便样本中球形梭菌与多形拟杆菌的水平;运用Pearson分析方法,对目标菌属水平与各组小鼠的空腹血糖(FBG)做相关性分析。结果 1与正常组比较,模型组中球形梭菌与多形拟杆菌水平均增高(P=0.017,P=0.002)。2两色金鸡菊醇提物高剂量组与模型组相比,球形梭菌与多形拟杆菌的水平下降,且有统计学差异(2周:P=0.027,P=0.006;4周:P=0.007,P=0.012)。3球形梭菌水平、多形拟杆菌水平均与FBG水平呈正相关。结论两色金鸡菊醇提物对2型糖尿病小鼠肠道菌群存在着一定的影响且与其血糖水平存在相关性。     

去卵巢小鼠肠道菌群和血脂的变化

目的探讨去卵巢对小鼠肠道菌群和血脂的影响。方法 12只10周龄C57BL/6小鼠随机分为2组:假手术组(SHAM组)和去卵巢组(OVX组),每组6只,进行12周的喂养。每2周测定小鼠体质量,12周后测肝脏指数、血清三酰甘油水平和游离脂肪酸水平,小肠进行病理学检查,收集小鼠粪便并在Illumina MiSeq测序平台进行16S rRNA基因测序检测。结果与SHAM组相比,OVX组小鼠体质量、肝脏指数、血清三酰甘油水平和游离脂肪酸水平明显增加(t=4.745,t=15.090,t=11.140,t=4.038,均P0.01)。与SHAM组相比,OVX组小鼠肠道Shannon Wiener指数明显降低(t=4.520,P0.01);在SMB53属(P=0.001)、拟杆菌属(P=0.017)、优杆菌属(P=0.018)、粪球菌属(P=0.019)、赖氨酸芽胞杆菌属(P=0.020)的丰度上差异有统计学意义。结论去卵巢小鼠血脂升高和肠道菌群失衡,提示肠道菌群可能是预防和治疗雌激素缺乏后脂质代谢异常的潜在靶点。     

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.     

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     

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.