益生元对抗生素引起的肠道菌群失调的作用

目的 评价益生元菊糖和大蒜多糖在治疗肠道菌群失调中的作用.方法 72只Balb/c小鼠随机分为6组,随机取出12只作为正常对照组,其余灌胃盐酸林可霉素和头孢曲松钠混合抗生素溶液3d,建立小鼠肠道失调模型后,以生理盐水灌胃作为自然恢复组,其余4组分别灌胃菊糖、低剂量大蒜多糖、高剂量大蒜多糖以及丽珠肠乐5d.受试小鼠无菌取粪,观察各组肠道菌群的数量变化、测量血清IgG,粪便内毒素含量、有机酸含量变化.结果 菊糖和大蒜多糖高剂量灌胃能加速恢复抗生素导致的小鼠肠道菌群失调,这两种益生元对内毒素的清理、免疫力的恢复也有积极的效果,效果均优于丽珠肠乐和自动恢复.结论 益生元有加快肠道菌群恢复和降低抗生素的破坏效果,有益于小鼠肠道健康.     

基于ERIC-PCR指纹图谱技术的小鼠肠道菌群失调分析方法的建立

目的采用常规菌群分析方法和ERIC-PCR技术对正常小鼠和抗生素相关性腹泻小鼠模型分别进行肠道菌群检测,结合细菌培养和DNA指纹图谱检测结果分析小鼠肠道内主导菌群数量和种类的改变情况,建立利用ERIC-PCR技术分析小鼠肠道菌群失调的检测方法。方法先利用常规菌群分析方法鉴定正常小鼠和抗生素相关性腹泻小鼠的菌群状况,再提取其基因组DNA,最后以肠杆菌科基因间重复序列(ERIC)为模板,利用ERIC-PCR方法获得正常小鼠和模型小鼠的肠道菌群指纹图谱,与常规菌群分析结果作比较,验证ERIC-PCR技术的准确性。结果常规菌群分析结果表明四种优势菌群在数量上出现明显的变化,证实造模成功。经ERIC-PCR技术成功获得两组小鼠粪便基因组DNA图谱,两组间呈现具有一定对比性的特异性指纹图谱。结论从小鼠粪便基因组经ERIC-PCR后的图谱中特异性条带的分布、数目和亮度来看,能说明肠道菌群的分布状况存在明显差异,结合常规菌群分析方法作对比,说明ERIC-PCR技术是一种分析小鼠肠道菌群失调高效快捷的检测方法。     

长链菊粉对抗生素处理后小鼠肠道菌群重建的影响

【目的】评价长链菊粉对抗生素致小鼠肠道菌群失调后肠道菌群的恢复情况。【方法】选择50只健康的10周龄BALB/c小鼠,随机分为2组,其中15只为正常对照组,余下35只饮用水中含4种抗生素连续喂养7 d,诱导小鼠肠道菌群严重失调后,再随机分为长链菊粉恢复组(饮用水中添加5%(W/W)长链菊粉)和自发恢复组(饮用水为无菌水),连续处理21 d。受试小鼠在抗生素治疗后的第7天以及恢复喂养的第7、14和21天,取结肠组织进行切片然后进行HE染色分析,无菌取粪便进行16Sr RNA测序分析,观察小鼠肠道组织及菌群恢复情况。【结果】抗生素处理7 d后,小鼠结肠组织有轻微炎症,但肠道菌群严重失调。组织学分析表明,在补充长链菊粉或自发恢复21d后,结肠炎症逐渐减轻;但相比于自发恢复,长链菊粉干预延迟了结肠组织的恢复。16S r RNA基因V3–V4区扩增子测序分析显示无论是长链菊粉补充还是自发恢复都无法在属水平上恢复肠道菌群组成。尤其是长链菊粉的补充,反而导致了某些机会致病菌的选择性扩增,并提高了与肠道菌群相关的疾病途径。【结论】抗生素诱导肠道菌群严重失调后补充长链菊粉会延迟肠道菌群的重建,可能会导致潜在的不良影响。     

中药903对抗生素脱污染小鼠肠道菌群的影响

本实验用抗生素给小鼠肠道脱污染造成肠菌群失调后.用中药903进行调整,旨在用中药903通过扶持肠道内有益菌群,抑制不利菌群,达到恢复微生态平衡的目的。将昆明种小鼠随机分成7组,每组6只小鼠,第1组为正常对照组,喂以与药物同体积的水,其他6组为抗生素脱污染组,联合用硫酸新霉素(20mg/ml)、头孢菌素V钠(20mg/ml)给小鼠灌胃,每天2次,每次0.5ml,连续3天。将6组抗生素脱污染组再分为5组治疗组,和1组抗生素脱污染对照组即自然恢复组。5组治疗组是:中药9031号     

PCR-DGGE技术评价抗生素诱导的肠道菌群失调

目的 利用PCR-DGGE技术结合活菌计数评价抗生素引起的肠道菌群失调.方法 SPF级BALB/c雌性小鼠连续4 d灌胃头孢曲松溶液125 mg/ml,0.4 ml/d,运用基于细菌16S DNA的PCR-DGGE技术结合活菌计数分析小鼠肠道菌群变化.结果 活菌计数结果与PCR-DGGE图谱显示,头孢曲松处理3 d后小鼠肠道菌群出现严重失调.结论 PCR-DGGE技术可直观而灵敏地显示抗生素处理过程中肠道菌群的动态变化,适用于评价抗生素引起的肠道菌群失调.     

中药"神曲"对肠道菌群失调小鼠调整和保护作用的观察

目的研究中药"神曲"在肠道微生态失调中的调整和保护作用.方法使用中药大黄煎剂给小鼠灌胃8 d,造成肠道菌群失调病理模型,将菌群失调小鼠分为5组模型组、自然恢复组、丽珠肠乐组、同仁堂神曲组和复方神曲组.实验动物经不同因素处理后,取结肠内容物、粪便进行菌群培养;取回肠组织进行各项病理指标的测定;取各组小鼠肝脏和结肠标本进行光镜观察.结果治疗组肠道菌群与正常对照组相比无明显变化,与自然恢复组相比差异有显著性(P＜0.05);各治疗组超氧化物歧化酶(superoxide dismutase,SOD)、丙二醛(methyl-di-alde-hyde,MDA)、黄嘌吟氧化酶(xanthine oxidase,XOD)和一氧化氮(NO)水平与正常组相比差异无显著性,与自然恢复组相比差异有显著性(P＜0.05);治疗组肝脏和结肠与正常对照组相比无明显变化,其与自然恢复组相比差异有显著性.结论中药"神曲"对肠道菌群失调动物具有调整和保护作用.     

焦米对番泻叶所致腹泻小鼠的止泻及肠道菌群影响研究

目的考察焦米水对肠道菌群失调性腹泻的调节作用。方法将小鼠分为5组,分别为模型组、正常组和生米组、焦米组、自由恢复组三组实验组,除正常组外,用番泻叶水煎液给小鼠灌胃连续6 d造成小鼠腹泻模型,实验组分别给予生米、焦米及生理盐水作为自由恢复组,每天观察各组小鼠腹泻情况,并且于第2天、第6天取小鼠粪便进行肠道菌群检测,并做菌群计数,数据进行统计学处理。结果成功建立了小鼠肠道菌群失调腹泻模型,焦米组小鼠腹泻较生米组和自由恢复组恢复较快,差异有统计学意义（P〈0.05）。给予生米、焦米的小鼠肠道菌群恢复较快,与自由恢复组相比差异有统计学意义（P〈0.05）,焦米组与生米组相比菌群有一定的提高,但差异无统计学意义（P〉0.05）。结论焦米水能明显的改善小鼠的腹泻症状,焦米有一定的提高小鼠肠道菌群,改善小鼠肠道菌群环境的作用。焦米与生米相比对腹泻小鼠的恢复促进调节作用更好,可能跟米炒焦后所生成的新物质有关。     

海参多糖对小鼠肠道菌群紊乱的恢复作用

目的探究海参多糖对抗生素所致小鼠肠道菌群失衡的调整作用。方法超声浸提法提取海参多糖,硫酸-苯酚法测定多糖含量;通过抗生素连续灌胃1周,构建小鼠肠道紊乱模型;将18只昆明种小鼠随机分为正常对照、自然恢复和海参多糖干预组(每组6只),定期留取粪便,采用PCR-DGGE技术获得肠道菌群分子指纹图谱,进行相似性、多样性及主要差异条带序列的分析。结果提取海参多糖的浓度为1.92 mg/mL;正常对照组小鼠肠道菌群以有益菌,即乳杆菌属和梭菌属占主导地位;而在抗生素干预后,这两种菌的含量明显下降,并伴随检测出致病性卟啉单胞菌属;经海参多糖处理后,有益菌含量有所恢复,有害菌含量降低。结论海参多糖对抗生素所致实验小鼠肠道菌群紊乱有一定的恢复作用。     

ERIC-PCR和PCR-DGGE技术分析壳聚糖对抗生素引起肠道菌群失调小鼠的影响

目的应用肠杆菌基因间重复共有序列基因扩增(ERIC-PCR)和聚合酶链式反应——变性梯度凝胶电泳(PCR-DGGE)分析壳聚糖对抗生素致肠道菌群失调小鼠的影响。方法 SPF级昆明小鼠24只,每组8只,依次分为模型组(N)、壳聚糖高(CS-H)和低浓度组(CS-L),盐酸左氧氟沙星灌胃6d后使用相应药物灌胃24d,收集鼠便,提取粪便细菌DNA,利用ERIC-PCR和PCR-DGGE电泳获得肠道菌群指纹图谱,主成分分析(PCA)和聚类分析(UPGMA)研究肠道菌群整体差异,并鉴定优势条带序列。结果 ERIC-PCR表明菌群失调组小鼠肠道中细菌条带减少明显,以300bp左右的条带为特征条带,PCR-DGGE显示屎肠球菌为优势菌型;壳聚糖灌胃小鼠肠道菌群结构组成发生改变,乳酸菌成为优势菌型。结论壳聚糖扶持乳酸菌等益生菌、抑制肠球菌等病原菌的增殖,起到益生元的作用进而调节肠道微生态均衡。     

流感病毒感染对小鼠肠道菌群的影响及桑叶的调节作用

【摘 要】 目的 探讨流感病毒对肠道菌群的影响以及桑叶提取物在治疗小鼠流感时对肠道菌群的调节作用。方法 将36只小鼠随机分为4组,正常对照组滴鼻生理盐水,其余以流感病毒鼠肺适应株FM1滴鼻3 d,建立流感小鼠模型后,正常对照组和病毒对照组灌胃生理盐水,另2组分别以高剂量(500 mg/kg)和低剂量(100 mg/kg)灌胃桑叶提取物,连续5 d。每天检测小鼠体重,并于病毒感染前、感染后及灌胃处理后3次无菌收集小鼠粪便,培养并计数小鼠粪便中肠杆菌、肠球菌、乳酸杆菌和双歧杆菌。结果 小鼠在感染病毒后体重明显降低,桑叶提取物治疗后体重降低的趋势有所减缓。小鼠肠道菌群在感染流感后有明显的变化,但桑叶提取物治疗后肠道菌群的恢复不明显。结论 流感病毒感染能引起小鼠肠道菌群的失调,桑叶不显示调节肠道菌群的效果,表明其对流感的治疗不通过调节肠道菌群平衡来发挥作用。     

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.     

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     

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.     

鸡传染性法氏囊病病毒研究进展

传染性法氏囊病(Infection bursal disease, IBD)是由鸡传染性法氏囊病毒(Infectious bursal disease virus, IBDV)引起的鸡和火鸡的一种高度接触性传染病,给世界各国的禽养殖业带来了巨大损失.自IBDV发现至今新的变异株不断出现,分子结构的改变导致病毒致病力的改变及宿主对疫苗应答的改变,使得传统的疫苗已不能控制其流行,因此各国学者对其基因组结构和功能进行了广泛深入的研究,并积极研制新型有效的疫苗以达到防治的目的.     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).