阴道毛滴虫双链RNA病毒感染及其对甲硝唑耐药性的影响

目的调查河南地区阴道毛滴虫临床分离株阴道毛滴虫病毒感染情况,探索病毒感染对阴道毛滴虫甲硝唑耐药性的影响。方法 TYM(trypticase-yeast extract-maltose)无菌培养基培养阴道毛滴虫临床分离株,达到纯培养后提取虫体总核酸(DNA和RNA),进行1%琼脂糖凝胶电泳分析;连续稀释法测量每株虫体的甲硝唑最小致死浓度。结果对30株阴道毛滴虫总核酸进行电泳,其中6株有5.5 kb双链RNA病毒带,病毒感染率为20.0%。阴道毛滴虫病毒阴性组甲硝唑最小致死浓度为(24.27±20.899)μg/ml,病毒阳性组为(5.68±3.588)μg/ml,差异有统计学意义(t=2.143,P<0.05)。结论河南地区阴道毛滴虫临床分离株中检测到阴道毛滴虫病毒,无阴道毛滴虫病毒寄生的虫体易发生甲硝唑抵抗。     

细胞周期调控因子在消化道肿瘤表达的研究进展

完整的细胞周期包括间期和有丝分裂期(M期),间期包括G1期、S期、G2期,细胞周期得以运行的机制在于一系列细胞周期素(cyclin)时相起伏的调控下,相应的周期素依赖性蛋白激酶( cyclin-dependend-kinase,Cdk)依次激活,驱动细胞由G0、G1、S、G2到M期.细胞周期主要有2个调定点:G1/S期、G2/M期.科学家已发现有几类调控因子在细胞周期中起着重要作用:第一类是对细胞分裂增殖有调控作用的细胞生长因子;第二类为细胞周期调控因子,又称内源性调节因子,是细胞内自己合成的蛋白质.细胞周期调控因子在细胞分裂增殖中发挥重要作用,异常表达致使肿瘤细胞过度分裂及增殖,导致肿瘤扩散及转移.细胞周期调控因子分2类:正调控因子(cyclin-Cdk)可促进细胞通过调定点,而负调控因子(Ckis)则可抑制细胞通过调定点.     

硝唑尼特体外抑杀阴道毛滴虫效果观察

目的观察硝唑尼特体外抑杀阴道毛滴虫效果。方法分别以2、1、0.5、0.25、0.125、0.062 5和0.031 25mg/ml,硝唑尼特作用于阴道毛滴虫携病毒株与无病毒株12和24 h,观察体外抑杀效果。实验以甲硝唑作为药物对照。结果随着药物浓度的增加和作用时间的延长,硝唑尼特对两种虫株的抑制率均增高,显微镜下可见滋养体活力下降,培养基底部有死亡虫体沉淀,染色后可见滋养体细胞质内有空泡,鞭毛脱落,虫体变形,细胞核变形,细胞膜破裂,细胞溶解。经统计学分析,硝唑尼特对阴道毛滴虫两种虫株的抑制率差异无统计学意义(χ2=0.12,P>0.05)。在24 h时,甲硝唑对阴道毛滴虫无病毒株抑制率为81.06%,硝唑尼特(1 mg/ml)对阴道毛滴虫两种虫株的抑制率可达100%,硝唑尼特对阴道毛滴虫无病毒虫株的抑制率显著高于甲硝唑(χ2=4.43,P<0.01)。结论硝唑尼特对阴道毛滴虫两种虫株均有较好的抑杀作用,其中对无毒株阴道毛滴虫的抑杀效果硝唑尼特优于甲硝唑。     

银杏黄酮苷对人巨细胞病毒感染的人脐静脉内皮细胞周期和凋亡的影响

目的:探讨人巨细胞病毒(HCMV)对人脐静脉内皮细胞(HUVEC304)细胞周期和凋亡的影响和机制及银杏黄酮苷对其感染HUVEC304的作用。方法:实验分为4组,分别为正常对照组、银杏黄酮苷组、HCMV感染组、HCMV感染加银杏黄酮苷组。采用流式细胞技术对HCMV感染的体外培养的HUVEC304及银杏黄酮苷对其作用后进行观察和分析。结果:HCMV感染HUVEC304后24h,正常对照组G0/G1期的细胞为74.4%,加入HCMV后为59.3%,较正常对照组降低20.3%(P<0·05)。正常对照组凋亡细胞为8.3%,当加入HCMV后为5.8%,较正常对照组降低30.1%(P<0·01)。银杏黄酮苷可以降低HCMV增加进入S和G2/M期的细胞,HCMV感染的细胞处在G0/G1期的为59.3%,用10-2mol/L银杏黄酮苷后被感染细胞处在G0/G1期的增加为67.5%,较感染组增加13.8%(P<0·05)。银杏黄酮苷可以增加HCMV感染的HUVEC304凋亡水平。HCMV感染后凋亡细胞为5.8%,加入10-2mol/L银杏黄酮苷后凋亡细胞为6.2%,较HCMV组升高6.9%(P<0·05)。结论:HCMV感染HUVEC304后,可以降低HUVEC304停留在G1期的细胞,使进入S和G2/M期的细胞明显增加,表明HCMV感染早期可通过增加G0/G1期细胞进入S和G2/M期,导致细胞最终表现为增殖。应用银杏黄酮苷可以促进细胞从G1期向S和G2/M期的转化和细胞的凋亡。HCMV感染HU-VEC304引起的炎性反应可能影响内皮细胞的功能,导致血栓形成、脂质代谢紊乱,最终参与动脉粥样硬化的形成。而银杏黄酮苷可促进HCMV感染HUVEC304的凋亡,抑制被感染细胞的过度增生,因而可能对防治动脉粥样硬化有一定的作用。     

治糜灵栓体外抗阴道毛滴虫的作用

目的 观察治糜灵栓体外杀灭阴道毛滴虫效果,为临床应用提供依据.方法 以实验药物治糜灵及对照药物甲硝唑配制大豆蛋白胨液体药物培养基,接种临床分离的阴道毛滴虫,培养24 h,观察药物的抗滴虫作用.结果 随着药物作用时间的延长和浓度的增加,滴虫死亡率升高,虫体裂解,密度下降.治糜灵对阴道毛滴虫的最低有效浓度为15 mg/ml.结论 治糜灵对阴道毛滴虫有较强的抑制作用.     

慢性浅表性胃炎脾胃湿热证患者舌苔脱落细胞活动周期的研究

目的 :探讨脾胃湿热证慢性浅表性胃炎患者舌苔脱落细胞与细胞周期活动的关系。方法 :实验分成 4组 :正常对照组、脾气虚组、脾胃湿热组和脾胃湿热治疗组 ,用流式细胞仪检测各组舌苔脱落细胞内 DNA含量。结果 :脾胃湿热组患者 S期细胞高于正常对照组和脾气虚组 ,差异均有显著性意义 (P <0 .0 1,<0 .0 5 ) ;经过清化饮治疗 1个月后 ,脾胃湿热组患者 S期细胞数目下降 ,而 G1 和 G2 加 M期细胞增加 (P <0 .0 5 )。凋亡细胞不论脾胃湿热组还是脾气虚组均高于正常对照组 ,经过治疗后的脾胃湿热组患者 ,虽然细胞周期有改变 ,但凋亡细胞无明显变化。结论 :脾胃湿热证慢性浅表性胃炎患者的舌苔脱落细胞周期中 ,S期细胞最多 ,治疗后 S期细胞减少 ,G1 期、G2 加 M期细胞增加 ;凋亡细胞脾胃湿热组和脾气虚组均高于正常对照组。     

双氢青蒿素对阴道毛滴虫微丝作用的观察

目的　探讨双氢青蒿素对阴道毛滴虫的杀伤效果及作用机制。　方法　用含双氢青蒿素的肝浸汤培养基培养阴道毛滴虫 ,观察药物对滴虫的杀灭效果 ;用激光共聚焦显微镜观察双氢青蒿素作用前后滴虫微丝的变化。　结果　随药物作用时间延长和药物浓度增加 ,阴道毛滴虫死亡率增高。同一时间随着药物浓度的增高 ,虫体死亡率升高 (P <0 .0 1)。作用 6h ,双氢青蒿素 0 .6mg ml虫体死亡率是 2 0 % ,而 1.0mg ml时高达 85 % ;同一药物浓度随着作用时间延长 ,滴虫死亡率也升高 (P <0 .0 5 ) ,药物 0 .8mg ml时 ,6h、8h、10h、12h和 14h死亡率分别是 43 %、68%、86%、97%和 10 0 %。药物作用后滴虫微丝排列疏松 ,有空隙生成。排列杂乱无序。　结论　双氢青蒿素可作用于滴虫微丝结构 ,破坏微丝 ,具有较强的杀滴虫作用。     

细胞周期调控与阿尔茨海默病的研究进展

近年来,随着对细胞周期及其调控研究的深入,人们发现Alzheimer病(AD)发病机制与细胞周期调控有关,提出了AD发病机制另一假说——细胞周期假说,对AD新的防治策略可能有指导性的意义。1　细胞周期细胞周期是指细胞从上一次分裂结束到下一次分裂完成所经历的整个过程。常将细胞周期划分为4个时期:依次为G1期(DNA合成前期)、S期(DNA合成期)、G2 期(分裂前期)和M期(有丝分裂期) ,完成其增殖过程。细胞周期不同时相之间存在着调控点(checkpoint) ,包括G1 / S期调控点、G2 / M期调控点。而这些调控点的通过有赖于细胞周期的主要调节子:细…     

葡萄糖酸-δ-内酯体外抗阴道毛滴虫作用的研究

目的通过对葡萄糖酸-δ-内酯体外抗阴道毛滴虫作用的实验观察,为该药的临床应用提供依据.方法以实验药物葡萄糖酸-δ-内酯及对照药物甲硝唑制成大豆蛋白胨液体药物培养基,接种临床分离的阴道毛滴虫,进行24 h培养,观察药物的抗滴虫作用.结果随着药物作用时间的延长和浓度的增加,滴虫死亡率升高,虫体裂解,密度下降.该药对阴道毛滴虫的最低有效浓度为16 mg/ml.结论葡萄糖酸-δ-内酯对阴道毛滴虫有较强的抑制作用.     

双氢青蒿素与甲硝唑体外抗阴道毛滴虫的电镜观察

目的观察双氢青蒿素与甲硝唑单用和联合用药体外对阴道毛滴虫超微结构的影响。方法在2.5×10~6个/ml滴虫培养液中加入两药合剂(双氢青蒿素0.5 mg/ml和甲硝唑0.002mg/ml),同时设不加药的阴性对照组和单药对照组,即甲硝唑组(5 mg/ml)、双氢青蒿素组(1 mg/ml),37℃培养3.5～5 h,扫描电镜和透射电镜观察阴道毛滴虫超微结构结果扫描电镜观察结果表明,仅用双氢青蒿素作用3.5 h,阴道毛滴虫细胞膜被破坏,部分表膜脱落;仅用甲硝唑作用3.5 h虫体表面结构无变化,作用5 h虫体表面出现许多小泡和小凹,但表膜未见破坏。两药联合作用3.5～4.2 h,阴道毛滴虫表面凹凸不平,出现皱褶、裂隙;细胞膜破损、脱落明显,表面粗糙,呈蜂窝状;细胞内含物从细胞膜裂口处溢出,虫体破裂,其内氢化酶体、核、轴柱和盾等裸露。透射电镜观察结果表明,仅用双氢青蒿素作用3.5 h,阴道毛滴虫膜系统破坏明显,破坏的滴虫细胞质从细胞膜破损处溢出;仅用甲硝唑作用3.5～5 h,细胞质破坏严重,细胞中可见许多空泡、裂隙和无结构区两药联合作用3.5～4.5 h,滴虫表膜破损,细胞内含物破坏严重,出现许多空泡、裂隙,内质网肿胀,氢化酶体膜破损、变形,细胞器大多消失;细胞核变形,核内出现裂隙,核膜受损,甚至消失。结论双氢青蒿素和甲硝唑对阴道毛滴虫的作用部位不同,两药联用可增进对虫体的破坏力。     

抗阴道毛滴虫AP33单克隆抗体的制备及其功能初探

目的 制备阴道毛滴虫（T.υ317株）黏附蛋白抗原（AP33）单克隆抗体并初步分析鉴定其功能。　方法　将制备和纯化的融合黏附蛋白33（rAP33）为抗原，免疫BALB/c小鼠，共免疫3次（抗原含量分别为100、50和100 μg），每次间隔2周，末次免疫后3 d取小鼠脾细胞及SP2/0骨髓瘤细胞在聚乙二醇（PEG1500）作用下进行细胞融合，筛选出高滴度分泌的McAb 杂交瘤细胞株，测定其免疫球蛋白亚类及其效价，蛋白质印迹（Western blotting）分析其特异性，间接免疫荧光实验（IFAT）进行定位，并初步探讨其体外对阴道毛滴虫黏附HeLa细胞的抑制作用。 结果 经筛选获得能稳定分泌抗AP33单克隆抗体的5株（4A2， 4F11， 4F8， 4E7和4H11）杂交瘤细胞株，经免疫球蛋白类型和亚型鉴定为IgG1; ELISA和Western blotting分析显示，5 株单抗均能与重组阴道毛滴虫AP33发生特异性结合；IFAT显示其中4株（4F11， 4F8， 4E7， 4H11）可识别培养的阴道毛滴虫，体外滴虫黏附抑制实验显示终浓度分别为200、200、400和200 μg/ml，该4株单抗体外对滴虫黏附HeLa细胞的抑制率分别为50.08%、65.03%、50.70%和49.08%。 结论 制备的抗重组AP33单克隆抗体，体外对阴道毛滴虫黏附有较好的抑制功能。     

阴道毛滴虫半胱氨酸蛋白酶3基因的克隆、表达与免疫原性分析

目的 研究小鼠对阴道毛滴虫（Trichomonas vaginalis）半胱氨酸蛋白酶3（TvCP3）重组蛋白的免疫应答。 方法 用PCR方法从阴道毛滴虫基因组DNA扩增TvCP3基因编码序列,分别用编码前体酶和成熟酶的基因片段构建重组表达质粒pET28b-TvCP3和pET28b-TvCP3C,转化入大肠埃希菌（E. coli）BL21（DE3）后进行诱导表达,通过金属螯合层析法（immobilized metal affinity chromatography,IMAC）纯化表达产物重组蛋白,复性后免疫BALB/c小鼠。BALB/c小鼠分为TvCP3免疫组、TvCP3C免疫组和对照组3组,每组6只,分别用TvCP3重组蛋白、TvCP3C和PBS免疫小鼠。第1次25 μg/只,福氏完全佐剂乳化;第2次25 μg/只,福氏不完全佐剂乳化;第3次与第4次12.5 μg/只,水剂。前3次免疫间隔2周,第4次间隔1周。末次免疫后1周用ELISA测定血清抗体滴度。采集高滴度小鼠血清制备免疫血清,通过蛋白质印迹（Western blotting）分析抗体所识别的阴道毛滴虫虫体或其分泌物中的特异性抗原组分。 结果 重组表达质粒 pET28b-TvCP3和pET28b-TvCP3C均能在E. coli BL21（DE3）中高效表达,重组蛋白占菌体总蛋白的25%以上;ELISA结果显示,纯化的重组蛋白TvCP3和TvCP3C免疫小鼠4次后血清抗体效价分别达1︰204 800和1︰102 400;Western blotting分析显示,小鼠免疫血清能特异性识别表达产物中的目的蛋白,以及阴道毛滴虫虫体或分泌物中的特异性抗原组分。 结论 重组表达质粒pET28b-Tvcp3和pET28b-Tvcp3C可在E. coli BL21（DE3）中高效表达,纯化的表达产物具有良好的免疫原性。     

阴道毛滴虫低温保存及其影响因素

观察不同浓度二甲亚砜(DMSO)和甘油、不同密度滴虫及不同冻存时间对阴道毛滴虫在-78℃低温保存的影响。阴道毛滴虫的最适冻存密度为(1～2)×106/ml。10%甘油和10%二甲亚砜的冻存效果最好,复苏存活率分别为38.0%和31.7%,两者差异无统计学意义(P0.05)。短期冻存(1～16周)的效果良好,均可在37℃重悬培养至对数生长期。     

铁离子对体外培养的阴道毛滴虫生长的影响

目的研究铁离子对体外培养的阴道毛滴虫生长的影响。方法在TYM(trypticase-yeast extract-maltose)培养基(pH6.0)中,分别加入100、200、300和400μmol/L铁离子,并设不加铁离子组为对照组,阴道毛滴虫初始浓度为1×105/ml,于37℃定量纯培养。采用台盼蓝染色法镜下观察并计数活滴虫数和死滴虫数,绘制生长曲线和存活率曲线,并计算对数生长期内世代时间。通过连续稀释的方法测定在加入200μmol/L铁离子培养基和对照组培养基中甲硝唑对阴道毛滴虫的最小致死浓度(minimal lethal concentration,MLC)。结果在加入100、200、300和400μmol/L铁离子的培养基中,阴道毛滴虫均于40h达最高密度,分别为2.9×106、3.2×106、3.1×106和2.8×106/ml,对照组阴道毛滴虫于54h达最高密度,为2.5×106/ml。400μmol/L铁离子组阴道毛滴虫的世代时间为(6.8±0.7)h,较100～300μmol/L铁离子组的世代时间[(4.8±0.3)、(4.8±0.2)和(5.0±0.4)h]延长(均P﹤0.05),而100～400μmol/L铁离子组的世代时间均短于对照组[(10.2±3.1)h](均P﹤0.05)。在加入200μmol/L铁离子的培养基中阴道毛滴虫的甲硝唑最小致死浓度为(23.44±11.56)μg/ml,显著低于对照组[(31.25±15.44)μg/ml](均P﹤0.05)。结论阴道毛滴虫在加入100～400μmol/L铁离子的TYM培养基中生长较快,且甲硝唑对阴道毛滴虫的最小致死浓度较小。     

紫外线减毒日本血吸虫尾蚴免疫小鼠的细胞免疫应答和细胞因子的动态变化

目的 :检测细胞免疫在血吸虫疫苗保护性免疫中的作用。方法 :用紫外线减毒日本血吸虫尾蚴 300±5条免疫小鼠及日本血吸虫尾蚴 25±3条感染小鼠。于第 2wk、4wk、8wk和 12wk分别用血吸虫成虫抗原(SWAP)、虫卵抗原 (SEA)及丝裂原(ConA或LPS)体外刺激脾细胞和腹腔巨噬细胞(Mφ),观察脾淋巴细胞的增殖反应及 Mφ产生 IL- 1和脾细胞产生 IL- 2的活性的动态变化。结果 :两组鼠的脾细胞于免疫或感染后2wk- 8wk经 SWAP或 SEA刺激 T淋巴细胞增殖反应显著增强,第12wk呈现明显抑制;免疫组的Mφ和脾细胞经SWAP或SEA 刺激于接种后第4wk IL-1 和IL-2 活性均显著增高, 感染组的Mφ和脾细胞经SWAP 刺激IL-1 于第8wk-12wk活性增高、IL-2 于第12wk 活性增高。结论: 提示减毒尾蚴免疫接种能较早地激活T 细胞增殖和细胞因子产生, 在血吸虫保护性免疫中起重要作用。     

Epidemiology of Sexually Transmitted Infections in Rural Southwestern Haiti: The Grand'Anse Women's Health Study

The study attempts to define socioeconomic, clinical, and laboratory correlates in vaginitis and other sexually transmitted infections in rural southwestern Haiti. A convenience sample of subjects recruited from a rural women''s health clinic and attending an established clinic at the Haitian Health Foundation (HHF) clinic was studied. A standardized history and physical examination, including speculum examination, and collection of blood, urine, and vaginal swabs were obtained from the women at the rural clinic. Additional vaginal swab samples only for Nucleic Acid Amplification Test (NAAT) testing were obtained from women at the HHF clinic in Jérémie. Laboratory results from Leon subjects were positive for Gardnerella vaginalis in 41% (41 of 100), Trichomonas vaginalis in 13.5% (14 of 104), Candida sp. in 9% (9 of 100), Mycoplasma genitalium in 6.7% (7 of 104), Chlamydia trachomatis in 1.9% (2 of 104), and Neisseria gonorrhea in 1% (1 of 104) of patients. Human immunodeficiency virus (HIV) antibody tests were negative in 100% (103 of 103) of patients, and syphilis antibody testing was positive for treponemal antibodies in 7.7% (8 of 104) patients. For subjects from the HHF, 19.9% were positive for T. vaginalis, 11.9% were positive for C. trachomatis, 10.1% were positive for M. genitalium, and 4.1% were positive for N. gonorrhea. Infections with G. vaginalis, T. vaginalis, and Candida were the most common. N. gonorrhea, C. trachomatis, Candida sp., T. vaginalis, and M. genitalium infections were associated with younger age (less than 31 years old).     

Effects of paclitaxel in combination with radiation on human head and neck cancer cells (ZMK-1), cervical squamous cell carcinoma (CaSki), and breast adenocarcinoma cells (MCF-7)

: The anticancer drug paclitaxel, a natural product from Taxus brevifolia, is a microtubule-stabilising agent, which has been shown to block different cells in the G2/M phase of the cell cycle and so modulate their radioresponsiveness. We investigated the radiosensitizing potential of paclitaxel in human head and neck cancer cells (ZMK-1), in cervical squamous cell carcinoma cells (CaSki) and in breast adenocarcinoma cells (MCF-7). Methods: ZMK-1 cells were incubated with paclitaxel for 3, 9, or 24 h before irradiation. ZMK-1-, CaSki- and MCF-7 cells were incubated with paclitaxel for 24 h after irradiation. The paclitaxel concentration (70 nM, 7 nM, 0.7 nM) was chosen to obtain equivalent toxicity at the different incubation times (3 h, 9 h, 24 h respectively). Radiation doses were from 0 to 8 Gy. Cell survival was measured by a standard clonogenic assay after a 9-day incubation. Flow cytometry was used to measure the capacity of paclitaxel to cause accumulation of cells in the G2/M phase of the cell cycle. Results: Paclitaxel alone was cytotoxic in a time- and concentration-dependent manner. Up to 36% of the ZMK-1 cells accumulated in G2/M after treatment for 24–36 h. If the cells were incubated with paclitaxel before irradiation the isoeffect enhancement ratios for ZMK-1 cells, determined at the 37% survival level, were 0.81, 1.48 and 1.15 for 3-h, 9-h, and 24-h pre-incubations respectively. For a paclitaxel incubation of 24 h after irradiation, the isoeffect enhancement ratios, determined at the 37% survival level, were 0.72, 0.76 and 1.2 for the ZMK-1, CaSki, and MCF-7 cells respectively. Conclusion: In the three cell lines no radiosensitizing effect of paclitaxel could be demonstrated unambiguously. The use of asynchronized cells or the support of cellular repair mechanisms while the cells are blocked in G2/M could partly explain the results. Received: 24 June 1998 / Accepted: 2 October 1998     

PCR based diagnostic assay targeting the beta tubulin gene for the detection of Trichomonas vaginalis infection in vaginal swab samples of symptomatic and asymptomatic women in India

ObjectiveTo develop an in-house PCR based diagnostic assay for identification of strains isolated from symptomatic and asymptomatic subjects of India, targeting the β-tubulin gene using specific primers.MethodsIn the present study a primer set is designed to target a well-conserved region in the beta-tubulin gene of Trichomonas vaginalis (T. vaginalis). All strains of T. vaginalis were tested and successfully detected by PCR yielding a single predicted product of 198 bp in gel electrophoresis, while there was negative response with DNA from Giardia lamblia, Toxoplasma gondii, Leishmania donovani and Entamoeba histolytica. The sensitivity and specificity for a single T. vaginalis cell per PCR was achieved. Axenic Culture, performed with long term axenized T. vaginalis culture system, was routinely examined to identify T. vaginalis.ResultsThe PCR based investigations with 498 vaginal swab samples from women attending OPD clinics of Halberg Hospital Moradabad and Queen Mary's Hospital, Lucknow, India and 17 long term axenic cultures maintained at PGIMER, Chandigarh, India using primer set BTUB 1 & BTUB 2 showed sensitivity and specificity response of 98% and 100%, respectively, while wet preparation in clinically isolated samples responded up to 62.5%. The PCR product sequencing result of symptomatic strains (SS1) of T. vaginalis (744 bp long) was submitted to NCBI (Accession No: JF513200). It shows maximum identity 98 % with XM_001284521 Trichomonas vaginalis G-3 beta-tubulin (btub) putative partial mRNA.ConclusionsThe data gathered in the present study entail that the diagnosis of T. vaginalis infection by PCR may be established as a sensitive and specific protocol, to be incorporated into a joint strategy for the screening of multiple STDs by employing molecular amplification technique. The merits and precautions of the protocol have been discussed.     

Synergistic anticancer properties of docosahexaenoic acid and 5-fluorouracil through interference with energy metabolism and cell cycle arrest in human gastric cancer cell line AGS cells

AIM: To explore the synergistic effect of docosahexaenoic acid(DHA)/5-fluorouracil(5-FU) on the human gastric cancer cell line AGS and examine the underlying mechanism.METHODS: AGS cells were cultured and treated with a series of concentrations of DHA and 5-FU alone or in combination for 24 and 48 h. To investigate the synergistic effect of DHA and 5-FU on AGS cells, the inhibition of cell proliferation was determined by MTT assay and cell morphology. Flow cytometric analysis was also used to assess cell cycle distribution, and the expression of mitochondrial electron transfer chain complexes(METCs)?Ⅰ, Ⅱ and Ⅴ in AGS cells was further determined by Western blot analysis. RESULTS: DHA and 5-FU alone or in combination could markedly suppress the proliferation of AGS cells in a significant time and dose-dependent manner. DHA markedly strengthened the antiproliferative effect of 5-FU, decreasing the IC50 by 3.56-2.15-fold in an apparent synergy. The morphological changes of the cells were characterized by shrinkage, cell membrane blebbing and decreased adherence. Cell cycle analysis showed a shift of cells into the G0/G1 phase from the S phase following treatment with DHA or 5-FU(G0/G1 phase: 30.04% ± 1.54% vs 49.05% ± 6.41% and 63.39% ± 6.83%, respectively, P 0.05; S phase: 56.76% ± 3.14% vs 34.75% ± 2.35% and 25.63% ± 2.21%, respectively, P 0.05). Combination treatment of DHA and 5-FU resulted in a significantly larger shift toward the G0/G1 phase and subsequent reduction in S phase(G0/G1 phase: 69.06% ± 2.63% vs 49.05% ± 6.41% and 63.39% ± 6.83%, respectively, P 0.05; S phase: 19.80% ± 4.30% vs 34.75% ± 2.35% and 25.63% ± 2.21%, respectively, P 0.05). This synergy was also reflected in the significant downregulation of the expression of METCs in AGS cells.CONCLUSION: Synergistic anticancer properties of DHA and 5-FU may involve interference with energy production of AGS cells via downregulation of METCs and cell cycle arrest.     

护龈灵体外抑杀口腔毛滴虫的研究

以40%～80%5个浓度的乙醇作为溶剂提取护龈灵有效成份,获取40%、50%、60%、70%和80%护龈灵醇提浸膏。实验设40%～80%护龈灵醇提浸膏组、甲硝唑对照组和空白对照组。护龈灵醇提浸膏各组分别再设5个亚浓度组,分别于125μl对数生长期口腔毛滴虫悬液(2×105个/ml)中加入终浓度为6.25、12.5、25、50和100mg/ml的各浓度护龈灵醇提浸膏;甲硝唑组的终浓度为10μg/ml,每组4孔。作用12、24和48h后,采用显微镜计数法检测护龈灵体外杀灭口腔毛滴虫的效果。并采用噻唑蓝(MTT)法检测药物作用24h后各浓度护龈灵醇提浸膏组对口腔毛滴虫的杀灭效果。结果显示,各浓度护龈灵醇提浸膏随着药物浓度的增大或药物作用时间的延长,对口腔毛滴虫的杀灭作用增强。药物浓度为6.25和12.5mg/ml的60%护龈灵醇提浸膏的相对杀虫率,与相同浓度的40%、50%、70%和80%护龈灵醇提浸膏之间的差异有统计学意义(P0.01),提示护龈灵醇提浸膏在体外具有较强的杀灭口腔毛滴虫作用,其中以60%护龈灵醇提浸膏的作用最强。