卷曲乳酸杆菌对Hela细胞的粘附研究

目的研究不同时期的生殖道卷曲乳酸杆菌A7对Hela细胞的粘附性。方法将对数期及稳定期的卷曲乳酸杆菌A7分别与Hela细胞进行粘附试验,经革兰染色后,通过显微计数法计算粘附数。结果处于对数期的卷曲乳酸杆菌A7在粘附时间为3 h时,其效果最佳。结论阴道卷曲乳酸杆菌A7对Hela细胞具有较强的粘附性。     

微管与肿瘤细胞运动——免疫细胞化学研究

运用免疫细胞化学方法对三种不等恶性程度人结肠腺癌细胞株HT-29分化较好,呈上皮样,细胞排列紧密,呈聚集性生长;免疫细胞化学显示;微管不甚明显。SW480及SW620细胞呈梭形。细胞间松散,常呈单个生长,免疫细胞化学显示微管十分丰富,该种形态特征与原发肿瘤恶性程度一致,前为高分化结肠腺癌,后为高恶性度结肠腺癌,具较强转移潜能,加入TGFβ1后,三株细胞均呈生长加速,多见分裂相,但微管未见明显改变,说明细胞快速分裂并非肿瘤浸润的唯一原因,加入道诺红菌素作用后,SW480及SW620微管结构出现明显改变,表现为断裂,卷曲或呈颗粒状。提示道诺红菌素能破坏细胞微管成分,微管的破坏可能抑制肿瘤细胞的转移。     

两种生物状态肠道益生菌的粘附和粘附拮抗效应的对比研究

目的:研究活菌和灭活菌两种生物状态的肠道主要益生菌--德氏乳杆菌、双歧杆菌和肠球菌对肠黏膜上皮细胞粘附性及其对肠道几种常见病原菌的粘附拮抗效应.方法:用光镜和电镜技术分析了两种生物状态的三种益生菌对肠黏膜上皮细胞的粘附指数,通过排除实验、竞争实验和替代实验研究了两种生物状态益生菌对侵袭性大肠埃希菌、产毒性大肠埃希菌和痢疾志贺菌的粘附拮抗效应,应用平板扩散法观察了三种益生菌的代谢乏液对上述肠道病原菌的抑制能力.结果:德氏乳杆菌和肠球菌的灭活状态较活菌状态对肠黏膜上皮细胞的粘附性显著增高,双歧杆菌经灭活后对细胞的粘附性与活菌相比差异无显著性,两种生物状态的三种益生菌对肠道致病菌均具有粘附拮抗作用.滤过后的德氏乳杆菌、双歧杆菌和肠球菌的代谢乏液对侵袭性大肠埃希菌、产毒性大肠埃希菌和痢疾志贺菌均具有较明显的抑制作用,经42℃、65℃和100℃加热不影响德氏乳杆菌和双歧杆菌代谢乏液的抑菌作用.结论:灭活状态的德氏乳杆菌、双歧杆菌和肠球菌是具有潜在开发价值的微生态制剂.     

地高辛对结直肠癌细胞株体外生长的影响

该文研究了地高辛(digoxin)对结直肠癌HT29、SW480和SW620细胞株增殖、迁移和侵袭能力以及上皮–间质转换(epithelial-mesenchymal transition,EMT)的影响。采用MTT检测不同浓度地高辛分别作用于HT29、SW480和SW620细胞株24、48、72 h后的细胞增殖。采用划痕实验测量细胞的迁移率。采用Transwell侵袭实验测定细胞侵袭能力。采用Western blot测定相关上皮–间质转换标志物E-钙黏蛋白(E-cadherin)、N-钙黏蛋白(N-cadherin)、SNAIL、Slug和波形蛋白(vimentin)以及VEGF蛋白质水平。RT-PCR检测地高辛干预细胞后VEGF mRNA水平。结果发现,地高辛能有效抑制HT29和SW480细胞的增殖,且具有浓度和时间依赖性,但对SW620细胞无显著抑制作用。地高辛能够抑制HT29和SW480细胞的迁移和侵袭能力,但对SW620细胞无显著作用。EMT标志物检测结果发现,与对照组相比,HT29和SW480细胞E-钙黏蛋白水平显著升高,N-钙黏蛋白、SNAIL、Slug、波形蛋白水平显著降低,SW620细胞E-钙黏蛋白水平显著升高,Slug蛋白质水平显著降低,但VEGF水平在SW620细胞无明显改变而在HT29和SW480细胞中显著降低。与对照组相比,地高辛干预HT29细胞后,细胞中VEGF mRNA水平明显降低,而SW620细胞无显著变化。结果提示,地高辛能够抑制结直肠癌细胞的增殖,抑制其EMT的发展,对治疗结直肠未转移癌具有更好的潜力。     

乳杆菌抑制金黄色葡萄球菌对HeLa细胞的粘附

对弯曲乳杆菌Lactobacillus crispatus T79-3和T90-1、詹氏乳杆菌Lactobacillus jensenii T118-3和T231-1四株乳杆菌对金黄色葡萄球菌生长的抑制效果以及抑菌成分进行了分析,比较乳杆菌排除、竞争、置换3种不同作用方式对金黄色葡萄球菌粘附HeLa细胞的抑制作用。结果表明4株乳杆菌皆能抑制金黄色葡萄球菌的生长及其粘附HeLa细胞的能力,分析发现4株乳杆菌发挥抑制作用的主要成分是有机酸,同时比较分析乳杆菌3种不同作用方式发现它们对金黄色葡萄球菌粘附HeLa细胞的抑制效果不同,其中,排除作用方式效果最好。另外,乳杆菌对金黄色葡萄球菌粘附HeLa细胞的抑制作用具有浓度依赖性,随着乳杆菌浓度增大,抑制作用增强并逐渐达到饱和。4株乳杆菌中,T79-3粘附能力最强,对金黄色葡萄球菌的抑制作用最强,排除作用方式抑制金黄色葡萄球菌粘附HeLa细胞作用效果较好,提示乳杆菌T79-3有可能作为益生菌防治妇女泌尿生殖道感染。     

S100A9参与介导具核梭杆菌促结肠癌细胞的增殖与迁移的作用

目的:探讨S100A9在具核梭杆菌(Fusobacterium nucleatum,Fn)促结肠癌HCT116和SW480细胞增殖与迁移中的作用。方法:Fn感染HCT116和SW480细胞后,分别采用CCK8实验及Transwell实验检测结肠癌细胞的增殖及迁移能力的变化,采用Real time PCR及Western blot分别检测S100A9基因及蛋白质水平的变化;用S100A9 siRNA转染HCT116和SW480细胞后感染Fn,采用CCK8实验及Transwell实验分别检测两株细胞增殖及迁移能力的变化;利用NF-κB抑制剂BAY 11-7082预处理HCT116和SW480细胞后再感染Fn,采用Real time PCR及Western blot分别检测S100A9基因及蛋白质水平的变化。结果:(1) Fn可促进HCT116和SW480细胞增殖及迁移(P 0.001);(2) Fn感染的HCT116和SW480细胞中S100A9基因及蛋白质水平均较相应对照组明显升高,差异均具有高度显著性(P 0. 01或P 0. 001),即Fn上调S100A9的表达;(3)用S100A9 siRNA下调HCT116和SW480细胞中S100A9表达后,Fn促进这两株细胞增殖及迁移的作用则明显减弱,差异均具有高度显著性(P 0. 001),表明S100A9参与介导Fn的促HCT116和SW480细胞增殖及迁移的作用;(4)在NF-κB通路抑制剂BAY 11-7082预处理的HCT116和SW480细胞组,Fn上调S100A9基因及蛋白质水平的作用明显被逆转,差异均具有高度显著性(P 0. 01或P 0. 001),表明激活NF-κB转录活性是Fn上调S100A9的机制之一。结论:Fn可上调S100A9表达且与NF-κB活化有关,上调S100A9是Fn促结肠癌细胞增殖及迁移的机制之一。     

乳酸菌表面蛋白对免疫细胞的诱导增殖及粘附抑制效应

目的研究表面蛋白在乳酸菌体外粘附和激活免疫细胞中的作用。方法应用5mol/L氯化锂结合盐酸胍提取植物乳杆菌LpYZU09、干酪乳杆菌LcYZU02、鼠李糖乳杆菌LrGG、发酵乳杆菌LfYZU15及戊糖片球菌PpYZU32的表面蛋白,并分析提取物对乳酸菌粘附鼠肠上皮细胞、巨噬细胞和脾细胞的抑制作用及诱导增殖效应。结果表面蛋白对3种细胞粘附菌体均具有显著抑制效应,抑制作用具有细胞和菌株差异性,其中菌株LrGG表面蛋白对巨噬细胞粘附5种菌体普遍显示了较强的抑制作用,抑制率为38.7%~76.0%。不同菌株表面蛋白对肠上皮细胞的诱导增殖指数为0.05~0.35,对巨噬细胞为0.05~0.42,对脾细胞为0.02~0.40,诱导效应具有菌株和剂量依赖性,菌株LrGG的诱导增殖指数显著高于其他四种。结论乳酸菌表面的蛋白类因子在粘附和激活免疫细胞中发挥了重要作用。     

鼠李糖乳杆菌-格氏乳杆菌联用对阴道致病菌的抑制作用

目的本文通过提取细菌基因组进行16S rDNA PCR扩增和测序,分析菌株的进化树分支,鉴定一株乳酸菌菌株RD-0060并检测RD-0060与已有菌株RD-0046联用的抑菌能力和细胞粘附能力。方法结合现有菌株RD-0046(格氏乳杆菌,Lactobacillus gasseri),采用牛津杯法研究RD-0060单菌、RD-0060和RD-0046联用抑制致病菌的能力。通过共培养细菌和阴道上皮细胞VK2/E6E7,研究RD-0060单菌和RD-0060/RD-0046二联菌粘附能力。结果 RD-0060为鼠李糖乳杆菌(Lactobacillus rhamnosus),具有抑制阿托波菌、阴道加德纳菌和常见好氧型病菌的功能,对阴道上皮细胞也有较强的粘附能力;RD-0060和RD-0046二联菌的抑菌效果和细胞粘附能力比单菌株更强。结论鼠李糖乳杆菌和格氏乳杆菌联用能显著抑制阴道致病菌生长,并且能够大量粘附阴道细胞,而且两菌株联用有协同效果,具有良好的临床应用和开发前景。     

新疆传统发酵乳品中益生菌的益生特性

目的以新疆传统发酵乳品中分离得到的14种发酵菌为研究对象,评价14种益生菌自聚集性能、表面疏水性、粘附性等益生特性;评价其抗生素耐药性的安全性能,并筛选对α-葡萄糖苷酶有一定抑制功能的益生菌。方法首先对14种发酵菌α-葡萄糖苷酶抑制率进行检测,然后检测14种发酵菌自聚集性能、表面疏水性和对Caco-2细胞的粘附率,最后进行耐药性试验。结果 14种发酵菌株均有良好的自聚集性能,哈尔滨乳杆菌自聚集性能最好(87.60%±0.16%);14种益生菌对乙酸乙酯有较高的表面疏水性,但对不同有机溶剂疏水性存在差异;乳酸菌中希氏乳杆菌对Caco-2细胞的粘附率最高(8.78%±0.65%)。酵母中乙醇假丝酵母对Caco-2细胞的粘附率最高(2.35%±0.04%)。14种发酵菌对Caco-2细胞的粘附性均大于1%;马乳酒样乳杆菌的α-葡萄糖苷酶抑制率最高(14.55%±0.74%),且除了瑞士乳杆菌(1.87%±0.09%),其他菌株抑制率都达到5%以上。戊糖乳杆菌和高加索乳杆菌对大多数抗生素表现出较高的敏感性,4种酵母对氟胞嘧啶和酮康唑均敏感。结论 10种乳酸菌和4种酵母都具有良好的益生特性,且未见对抗生素、抗真菌药物发生耐药。     

乳杆菌DM8909对金黄色葡萄球菌与阴道上皮细胞粘附影响的研究

本文对乳杆菌ＤＭ８９０９对阴道主要致病菌金黄色葡萄球菌与阴道上皮细胞的粘附影响作了补充实验。将等量ＤＭ８９０９液与金黄色葡萄球菌液同时与上皮细胞粘附进行了观察。结果表明,体外试验中,在ｐＨ７２情况下,乳杆菌与葡萄球菌同时加入时葡萄球菌粘附数量比葡萄球菌单独粘附少（Ｐ＜００１）,乳杆菌与金葡菌粘附数量相差不大（Ｐ＞００５）;乳杆菌与金葡菌先于ｐＨ４５下作用８１２ｈ,然后与上皮细胞同时孵育２小时,粘附的乳杆菌与金葡菌量比ｐＨ７２时均有减少,而金葡菌量比其单独粘附明显减少（Ｐ＜００１）,且明显少于乳杆菌（Ｐ＜００１）。说明乳杆菌能抑制葡萄球菌对阴道上皮细胞的粘附     

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).     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.