DADS对人小细胞肺癌NCI-H446细胞系增殖抑制的研究

目的：研究二烯丙基二硫（diallyldisulfide,DADS）对人小细胞肺癌NCI．H446细胞增殖的抑制作用,并探讨其作用机制。方法：体外培养NCI-H446细胞,采用MTT、细胞计数实验方法检测DADS抑制NCI—H446细胞增殖;通过HE染色和AO—EB荧光染色方法,观察DADS处理后NCI—H446细胞的形态学改变。结果：MTT结果显示：DADS作用于NCI—H446细胞48h后,代谢MTT的能力明显降低,显示出较强的细胞毒性反应,IC50值介于20-40μg／ml之间。细胞计数结果表明：DADS作用于NCI—H446细胞后,随DADS浓度增加NCI—H446细胞倍增时间延长。HE染色显示：NCI—H446细胞经DADS处理24h后,与对照组相比,细胞体积变小,胞浆丰富,细胞核变小,染色变淡。AO-EB荧光染色显示：NCI-H446细胞经DADS处理24h后,与对照组相比,细胞皱缩、呈圆形,胞质黄色或橘红色,细胞核或细胞质内可见致密浓染的黄绿色或橘红色荧光,并可见橘红色碎片且随DADS浓度增加,随DADS浓度增加细胞密度逐渐减少。结论：DADS能抑制体外培养的NCI—H446细胞增殖,作用效果与药物浓度及作用时间相关。     

二烯丙基二硫对人白血病K562细胞增殖及Bcl-2表达的影响

目的:探讨二烯丙基二硫(DADS)对白血病K562细胞增殖的影响,以及Bcl-2表达的调节作用.方法:用DADS预处理白血病K562细胞构建细胞模型,MTT法分别检测不同DADS浓度(5 gmL-1、10 g mL-1、20 g mL-1、40 g mL-1)和不同处理时间(6h、12h、24h、48h)细胞增殖情况,IC50浓度处理白血病K562细胞之后,Western blot和RT-PCR检测Bcl-2蛋白和mRNA表达水平.结果:MTT结果显示DADS能够抑制白血病K562细胞的增殖,且呈剂量和时间依赖性;IC50浓度的DADS处理K562细胞24小时后,Bcl-2蛋白和mRNA的表达量显著减少.结论:DADS可显著抑制K562细胞增殖,而这一作用可能与Bcl-2表达下调有关.     

温热抑制人胃癌SGC7901细胞增殖、迁移

目的探讨温热对人胃癌SGC790l细胞增殖、迁移的影响。方法对照组常温(37℃)下培养人胃癌SGC790l细胞,实验组43℃水浴加热0.5h、1h、2h、3h后培养24h,采用倒置显微镜观察胃癌细胞的形态结构变化;Hoechst-33258荧光染色观察细胞核的变化;四甲基偶氮唑盐比色法(MTT)检测细胞增殖抑制;细胞划痕愈合实验观察温热对胃癌细胞的运动迁移能力的影响;体外细胞侵袭实验(Transwell实验)观察温热对胃癌细胞侵袭能力的影响。结果温热后细胞明显皱缩、变圆及细胞漂浮,3h大部分细胞漂浮;荧光染色显示温热后部分细胞核内出现浓染致密的颗粒块状荧光,胞核固缩、染色质高度凝聚和碎裂;MTT实验提示温热可明显抑制SGC790l细胞生长;细胞划痕实验发现SGC790l细胞温热1h、2 h后细胞迁移距离均明显小于对照组,温热3h后细胞基本未发生迁移;Transwell实验提示SGC790l细胞温热后细胞侵袭能力明显下降。结论温热对胃癌SGC790l细胞具有明显的杀伤作用,温热可明显抑制胃癌SGC790l细胞增殖和侵袭迁移能力。     

五步蛇毒AAVC-I对人口腔鳞癌细胞的增殖抑制作用

目的观察祁门五步蛇毒抑瘤组分I(Agkistrodon acutus venom component-I, AAVC-I)对人口腔鳞癌Tca8113细胞的增殖抑制及凋亡的影响。方法以离子交换和凝胶过滤法从安徽祁门五步蛇粗毒中分离纯化五步蛇毒AAVC-I。常规培养口腔鳞癌Tca8113细胞,观察正常细胞形态学。实验分为对照组(加入等量细胞培养液)和实验组(分别加入AAVC-I 2.5、5.0、10.0μg/ml)。采用MTT法检测不同浓度(2.5、5.0、10.0μg/ml)的AAVC-I对Tca8113细胞24、48及72 h的增殖抑制率,倒置显微镜观察不同浓度AAVC-I处理后的细胞形态变化,透射电镜及AO/EB双荧光染色观察AAVC-I对细胞凋亡的影响,并与对照组进行比较。结果与对照组比较,实验组AAVC-I对Tca8113细胞增殖具有明显抑制作用(P0.05);AAVC-I处理后,倒置显微镜下可见明显细胞凋亡现象,电镜下可见细胞核染色质、胞质浓缩及凋亡小体;AO/EB双荧光染色可见细胞膜完整,细胞核致密浓染,染成黄绿色荧光的早期凋亡细胞及细胞膜破损,细胞核浓聚及偏移,呈橘红色荧光的晚期凋亡细胞。结论祁门五步蛇毒AAVC-I能抑制人口腔鳞癌Tca8113细胞生长增殖,诱导其凋亡。     

紫花牡荆素诱导人肝癌HepG2细胞凋亡的研究

目的：研究紫花牡荆素（Casticin）对肝癌HepG2细胞增殖抑制和凋亡诱导的作用,并探讨其作用机制。方法：用终浓度为0、0.5、1.0、2.0umol/L的Casticin作用于HepG2细胞,于12、24、48h后采用MTT法检测细胞增殖抑制率;Hoechst33342核染色,观察细胞形态学变化;24h后收集各组肝癌HepG2细胞,流式细胞术检测细胞周期及凋亡率;RT-PCR检测survivin mRNA表达。结果：MTT法检测显示,Casticin对肝癌HepG2细胞有增殖抑制作用,并存在浓度和时间依赖关系;Hoechst33342染色后,可见核染色质凝集,凋亡细胞呈致密浓染,与对照组相比,Casticin处理后凋亡细胞比例增加;Casticin作用24h后,细胞被阻滞于G2/M期,随药物质量浓度的增加,细胞凋亡率逐渐增加;RT-PCR结果显示,Casticin下调肝癌HepG2细胞survivin mRNA表达。结论：Casticin在体外对肝癌HepG2细胞有明显的增殖抑制和凋亡诱导作用,初步推断Casticin诱发肝癌细胞凋亡与其对survivin基因表达的抑制有关。     

Fractalkine对大鼠肺动脉平滑肌细胞增殖的影响

目的：观察fractalkine（FKN）对体外培养的大鼠肺动脉平滑肌细胞（PASMCs）增殖的影响。方法：体外培养大鼠PASMCs,加入不同浓度（10-^10、10-^9和10-^8 mol／L）的FKN处理12h、24h和48h,采用四唑盐（MTT）法检测细胞增殖,流式细胞术（FCM）检测细胞周期。结果：MTT试验显示FKN显著促进大鼠PASMCs增殖,此作用呈浓度依赖性。FCM分析显示FKN使S期细胞比例和增殖指数P1值增加。FKN处理PASMCs 12h后,其S期细胞比例和H值即出现增加,24h达高峰。结论：FKN呈浓度依赖方式促进大鼠PASMCs增殖。     

冬凌草甲素对人结肠癌细胞株HCT116生长的影响及其机制研究

目的：研究冬凌草甲素（ORI）对人结肠癌细胞株HCT116生长的影响及其可能机制。方法：以体外培养的HCT116细胞为研究对象,给予不同浓度（0、2.5、5、10、20μM）ORI处理HCT116细胞不同时间（0、24、48、72 h）,通过MTT法检测其对HCT116细胞增殖的影响,DAPI染色观察其对细胞核的形态的影响,western blot检测细胞内β-catenin、c-myc蛋白表达的变化。结果：1ORI可显著抑制HCT116细胞的增殖,且此作用随着浓度和作用时间的增加或延长而增强（P〈0.05）。2ORI处理HCT116细胞24小时后,细胞核固缩的百分率随药物作用浓度的增加而增加。35、10、20μM ORI处理HCT116细胞24小时后,细胞内的β-catenin、c-myc蛋白水平均显著下调,且随着ORI浓度的增加逐渐减少。结论：ORI能以浓度和时间依赖性的方式抑制HCT116细胞的增殖,其机制可能与Wnt/β-catenin信号通路有关。     

口蹄疫病毒前导蛋白(Lpro)致牛肾细胞(MDBK)作用的形态学观察

为探讨口蹄疫病毒Lpro致MDBK细胞病变效应中的形态学变化,本实验在成功构建可稳定表达口蹄疫病毒Lpro目的基因的MDBK细胞系的基础上,人工诱导Lpro表达后,采用光学显微镜观察、Hoechst33258染色、AO-EB染色、DNALadder等进行检测,研究口蹄疫病毒Lpro致MDBK细胞的病变效应。结果显示,MDBK细胞系在诱导表达口蹄疫病毒Lpro24h后,光学显微镜下细胞形态表现为细胞体积缩小、核浓缩、细胞周围出现透明圈等现象;Hoechst33258染色检测呈现典型的细胞核浓缩和梅花状核碎裂;诱导表达Lpro36h后,AO-EB染色显示早期病变细胞核染亮绿色呈致密斑块或碎片状,晚期病变细胞核染橘黄色呈致密斑块;DNA凝胶电泳显示可见的DNALadder"梯状"条带。证明口蹄疫病毒Lpro在体外可诱导MDBK细胞发生凋亡。     

蓖麻根提取物对HepG2,NCI-H460和SGC-7901细胞增殖及凋亡作用的影响

探讨蓖麻根不同提取物对肝癌HepG2细胞株、肺癌NCI-H460细胞株和胃癌SGC-7901细胞株增殖及其凋亡的影响.采用MTT法检测蓖麻根不同提取物处理48h、72h对HepG2细胞、NCI-H460细胞和SGC-7901细胞增殖的抑制率;Hoechst 33258荧光染料染色法观察HepG2细胞凋亡,流式细胞术检测...     

二烯丙基二硫化合物对食管癌Eca109细胞抑制作用

[目的]探究二烯丙基二硫化合物(DADS)对人食管癌细胞Eca109生长活性、增殖抑制及细胞周期的影响。[方法]以不同浓度的DADS处理Eca109细胞,MTT法检测细胞的生长曲线和增殖抑制率;流式细胞仪(FCM)测定细胞周期阻滞情况。Hoechst33258染色法并在荧光显微镜下观察细胞形态变化。[结果]DADS呈时间和剂量依赖性抑制Eca109细胞生长,272μmo L/L DADS作用Eca109细胞72 h,细胞增殖抑制率达到64.3%,IC50为100μmo L/L;荧光显微镜及流式细胞术结果显示DADS促使Eca109细胞形态发现显著变化,且出现凋亡小体,同时呈剂量依赖性阻滞细胞周期进程于G2/M期。[结论]大蒜DADS抗肿瘤的机制可能是通过细胞增殖抑制促使细胞发生形态变化,并将细胞周期阻滞在G2/M期,最终导致肿瘤细胞发生凋亡。     

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.     

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.     

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.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8⁺ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8⁺ T cells are involved in the pathogenesis of RE.     

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).     

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.