乳酸杆菌发酵滤液对人宫颈癌细胞株Hela细胞的抑制作用

目的观察乳酸杆菌DM9811发酵滤液及其主要成分对宫颈癌细胞株Hela细胞的体外增殖的影响,探索乳酸杆菌发酵滤液对宫颈癌细胞是否有抑制作用及解析作用的有效成分。方法用MTr法研究不同浓度乳酸杆菌DM9811发酵滤液在不同时间对Hela细胞的抑制作用,在此基础上研究脂肪酸、菌体核酸在不同时间对Hela细胞的抑制作用。结果不同浓度乳酸杆菌DM9811发酵滤液及相关物质在不同时间对Hela细胞的抑制作用显示：（1）乳酸杆菌DM9811发酵滤液各浓度组对Hela细胞的生长均有抑制作用,且这种抑制作用呈剂量-时间依赖方式。24、48、72h达到半数抑制率的发酵滤液浓度分别为8．9％、5．3％、3．8％。（2）乳酸杆菌DM9811发酵滤液脂肪酸对Hela细胞的生长有一定抑制作用,抑制率在7．0％～34．0％。（3）乳酸杆菌DM9811菌体核酸对Hela细胞的生长有抑制作用,抑制率为9．7％-53．4％,呈剂量一时间依赖方式。72h达到半数抑制率核酸的浓度为5．5μg/ml。结论乳酸杆菌DM9811发酵滤液对Hela细胞的生长具有显著的抑制作用,其中脂肪酸组分是有效成分之一。     

乳酸杆菌发酵液RNA的抗肿瘤及对巨噬细胞功能的调节作用

目的研究乳酸杆菌DM9811发酵滤液中存在的100200 bp长的RNA片段（Ls-RNA）的免疫调节与抗肿瘤作用。方法采用中性红吞噬试验检测巨噬细胞吞噬功能,用L929细胞检测TNF,用免疫保护试验检测体内抗肿瘤作用。结果Ls-RNA可增强脾巨噬细胞的吞噬活性,对小鼠肝癌Hca-F的生长有抑制作用,延长小鼠的存活时间,但对TG诱导的腹腔巨噬细胞产生TNF无明显调节作用。结论Ls-RNA有一定免疫调节和抗肿瘤作用。     

口服乳酸杆菌对实验动物免疫功能及肠道正常菌群的影响

本文报告C_(57)BL/6小鼠口服乳酸杆菌后,脾细胞和胸腺细胞的增殖反应,腹腔巨噬细胞的C_3b受体活性及其对L_(929)细胞的细胞毒性作用都明显增强。停用乳酸杆菌10天后,以上免疫指标又恢复到正常水平。其次,Wister大鼠口服乳酸杆菌后,检查粪便菌群中几种厌氧菌和需氧菌的活菌数目,结果表明对厌氧菌群的生长有扶持作用,对需氧菌群的生长则起限制作用,这提示有利于宿主调整肠道正常菌群的平衡。     

乳酸杆菌发酵滤液对人宫颈癌细胞株Hela细胞的细胞周期和细胞凋亡的影响

目的观察乳酸杆菌DM9811发酵滤液对宫颈癌细胞株Hela细胞的细胞周期和细胞凋亡的影响,探索乳酸杆菌发酵滤液对宫颈癌细胞作用的可能机制。方法用光镜、电镜和流式细胞仪分析不同浓度乳酸杆菌DM9811发酵滤液对Hela细胞凋亡的诱导效果;用流式细胞仪分析不同浓度乳酸杆菌DM9811发酵滤液对Hela细胞细胞周期的影响。结果（1）乳酸杆菌DM9811发酵滤液可诱导宫颈癌Hela细胞凋亡。形态学观察处理后的Hela细胞,可见细胞变形,细胞皱缩,体积变小,细胞间隙增大,细胞核固缩。流式细胞仪分析,1%、2%的乳酸杆菌DM9811发酵滤液在48、72h可诱导Hela细胞凋亡;5%的乳酸杆菌发酵滤液在24、48和72h均可诱导Hela细胞凋亡。（2）乳酸杆菌DM9811发酵滤液阻滞宫颈癌Hela细胞于S期,不同浓度的乳酸杆菌发酵滤液作用24、48和72h均可使S期细胞比阴性对照组增多。结论乳酸杆菌DM9811发酵滤液可诱导部分Hela细胞凋亡,其对Hela细胞的生长抑制作用可能通过S期阻滞实现。     

Ag85ADNA疫苗对荷瘤鼠Th1细胞免疫功能的影响

为了探讨肌肉注射Ag85A DNA疫苗能否在肿瘤宿主,一个低细胞免疫应答的机体内激发Th1型细胞免疫应答,将6~8周龄BALB/c雌性小鼠随机分成实验组(Ag85A-V1Jns.tPA组),空质粒组(V1Jns.tPA组)和生理盐水组3组,将生长旺盛的Meth-A细胞接种于各组小鼠右侧背部皮下,每只小鼠2×105个细胞,1d后于小鼠大腿肌肉内分别注射100μL Ag85A-V1Jns.tPA(1 g/L),V1Jns.tPA(1 g/L)或生理盐水。每10 d 1次,共3次,于末次注射后第8 d,无菌取脾,分离细胞进行培养。检测NK细胞活性以及脾细胞培养上清中IFN-γ含量。结果显示:实验组平均NK细胞杀伤率以及脾细胞培养上清中IFN-γ含量较空质粒组和生理盐水组均显著增高,而空质粒组和生理盐水组之间未见有意义的变化。提示肌肉注射Ag85A DNA疫苗可以提高Meth-A纤维肉瘤荷瘤小鼠Th1细胞免疫功能。     

双歧杆菌培养滤液中核酸的提取及对肠癌细胞cAMP,cGMP的影响

实验观察了对数期长双歧杆菌、青春双歧杆菌培养滤液中提取的总核酸对肠癌细胞ｃＡＭＰ、ｃＧＭＰ的影响。结果发现,双歧杆菌培养中滤液中存在大量核酸,将双歧杆菌培养滤中的核提取纯化作用于大肠癌细胞ＣＣＬ１８７,ｃＡＭＰ增高,ＣＧＭＰ没有变化,提示核酸可能作为细胞膜外的第一信使物质腺苷环化酶活性。     

乳酸杆菌造成的微环境对阴道毛滴虫的影响

目的:研究乳酸杆菌产生的微环境对阴道毛滴虫的影响,为新型微生态制剂的开发提供可靠依据.方法:于滴虫生长高峰期分别将0.25 ml,0.5 ml,1.0 ml,2.5 ml已培养、鉴定好的浓度为3.0×108/ml乳酸杆菌加入到最适pH值肝浸汤培养基中,观察不同乳酸杆菌浓度的培养基中滴虫死亡情况.结果:乳酸杆菌浓度为0.5×108/ml与0.14×108/ml、0.27×108/ml、1.0×108/ml比较,在其浓度为0.5×108/ml时滴虫的死亡率明显要高.结论:体外试验中对阴道毛滴虫生长的抑制作用最强的乳酸杆菌浓度为0.5×108/ml.     

维生素E对免疫功能的影响

适当剂量的维生素Ｅ（ＶＥ）,能增强抗体和补体的产生以及抗体对抗原的应答反应,促进淋巴细胞的增殖、分化和细胞因子的产生,提高免疫细胞的细胞毒作用和吞噬细胞的吞噬作用。ＶＥ缺乏或过量,能抑制机体的免疫机能,降低对疾病的抵抗能力。     

激光对机体免疫功能的影响

激光对机体免疫功能的影响黄瑜峰,黄卓正广西医科大学附属肿瘤医院５３００２１近十年多来激光技术在临床医学上的应用日益广泛,弱激光照射治疗某些疾病国内外均有许多成功的报道,但对其作用机理目前尚未十分清楚。为此,促使人们探讨弱激光治疗的作用机制进行了多方面...     

乳杆菌对数生长期培养基滤液核酸组分分析

目的通过对乳杆菌对数生长期培养基滤液中核酸组分的分析,阐明乳杆菌DM9811对数生长期培养基滤液中核酸的性质。方法应用核酸的分离、纯化及电泳分析技术。结果乳杆菌对数生长期培养基滤液中核酸组分为RNA,其片段大小为100 bp左右。乳杆菌对数生长期培养基滤液中核酸组分为RNA,为对数期产生且呈时间依赖关系。结论核酸组分不仅仅是遗传信息的载体,还可能作为有效的信息分子。     

乳酸杆菌DM8909胞壁肽聚糖对小鼠阴道感染的免疫调节作用

目的 通过对小鼠阴道组织的细胞因子测定来反映乳酸杆菌肽聚糖对阴道局部的免疫调节作用.方法 6～8周龄昆明小鼠共36只,随机分为6组,每组6只,A组为正常对照组,其余各组用抗生素和大肠埃希菌EPEC104造成小鼠阴道感染模型后分别给予不同处置,其中B组为患病组,C组为自然恢复组,D组为生理盐水治疗组,E组乳酸杆菌治疗组,F组乳酸杆菌肽聚糖治疗组;对各组采用ELISA(酶联免疫吸附法)来测定小鼠阴道局部组织的细胞因子IL-2及IL-10的水平.结果 (1)各研究组中IL-2的水平:与A组比较,B、C、D组IL-2的水平明显升高,差异有统计学意义(P＜0.01),E、F组差异无统计学意义(P＞0.05);与B组比较,A、E、F组IL-2水平明显降低,差异有统计学意义(P＜0.01),C、D组差异无统计学意义(P＞0.05);而E组和F组比较差异也无统计学意义(P＞0.05).(2)各研究组中IL-I0的水平:与A组比较,B组IL-10的水平明显降低,差异有统计学意义(P＜0.0l),C、D组IL-10水平下降,差异有统计学意义(P＜0.05),E、F组差异无统计学意义(P＞0.05);与B组比较,A、E、F组明显升高,差异有统计学意义(P＜0.01),B、D组差异无统计学意义(P＞0.05);而E组和F组比较差异无统计学意义(P＞0.05).结论 乳酸杆菌肽聚糖作为乳酸杆菌免疫调节主要成分,通过影响细胞因子的表达,对阴道感染起到了免疫调节作用.     

从土壤中提取细菌和芽孢核酸用于PCR的研究

本文探讨了土壤中提了细菌及其芽孢DNA用于PCR扩增检测的方法,我们采用的碘化钠裂解,玻璃粉吸附方法,可以有效提取和纯化土壤中的细菌及芽孢的核酸,操作简便,不需要特殊设备,提取的核酸可直 用于PCR扩增反应,我们用炭疽芽孢杆菌A16R疫苗株的芽孢的类鼻疽伯克霍尔德氏菌污染土壤,使用这一方法从中提取核酸,并用于PCR扩增,证实了该方法的实用性。     

Biochemistry of selenium-derivatized naturally occurring and unnatural nucleic acids

Selenium (Se) can provide unique biochemical and biological functions, and properties to macromolecules, including protein and RNA. Although Se has not yet been found in DNA, identification of the presence of Se in natural tRNAs has led to discovery of the naturally occurring 2-selenouridine and 5-[(methylamino)methyl]-2-selenouridine (mnm(5)se(2)U). The Se-atoms at C(2) of the modified uridines are introduced by 2-selenouridine synthase via displacement of the S-atoms in the corresponding 2-thiouridine nucleotides of the tRNAs, and selenophosphate is used as the Se donor. The research indicated that mnm(5)se(2)U is located at the first or wobble position of the anticodons in several bacterial tRNAs, including tRNA(Lys), tRNA(Glu), and tRNA(Gln). The 2-seleno functionality on this modified nucleotide probably improves the translation accuracy and/or efficiency. These observations in vivo suggest that the presence of Se can provide natural RNAs with useful properties to better function and survival. To further investigate the biochemical and structural properties of Se-derivatized nucleic acids (SeNA), we have pioneered chemical and enzymatic synthesis of Se-derivatized nucleic acids, and introduced Se into both RNA and DNA at a variety of positions by atom-specific replacement of oxygen. This review outlines the recent advancements in chemical and biochemical syntheses, and studies of SeNAs, and their potential applications in structural and functional investigation of nucleic acids and their protein complexes.     

The effects of pH and salts on nucleic acid partitioning during phenol extraction

The partitioning of nucleic acids is sensitive to pH during phenol extraction. However, the exact effects of pH on phenol extraction had not been systematically investigated, and the mechanism of which were not fully elucidated. In this paper, we showed that the partitioning of nucleic acids was determined neither solely by the pH of the aqueous buffer being used, nor by the “pH of the phenol”; the latter is a completely wrong conception. We demonstrated that a key determinant for nucleic acid partitioning during phenol extraction was the equilibrated pH of the aqueous phase, which should be defined as the pH of phenol extraction. For example, when 50?mM NaAc-HAc buffer at pH of 3.47 was mixed with an equal volume of water-saturated phenol, the equilibrated pH of aqueous phase would be raised to ～3.84. At this pH, almost all of genomic DNA partitioned into the phenol phase, and genomic DNA-free total RNA was retained in the aqueous phase. Several salts were found affecting the partitioning of nucleic acids during phenol extraction in different manners. Based on these results, a low-cost and efficient method for genomic DNA-free total RNA extraction was developed.     

乳杆菌活菌制剂对细菌性阴道病局部免疫的调节

目的检测正常人和细菌性阴道病(BV)患者治疗前后阴道局部细胞因子的变化,探讨乳杆菌活菌制剂对女性生殖道免疫的影响,为阴道微生态平衡与阴道黏膜免疫屏障的关系的研究提供一定的依据。方法用乳杆菌活菌制剂治疗BV,通过酶联免疫吸附试验法即ELISA法来检测BV患者治疗前后及正常健康妇女阴道局部细胞因子sIgA、IL-2、IL-13的水平。结果 sIgA、IL-13水平治疗前组较对照组明显升高(P<0.01),治疗后组较治疗前组水平下降(P<0.05),治疗后组较对照组水平升高(P>0.05);IL-2水平治疗前组较对照组明显降低,治疗后组较治疗前组明显升高(P<0.05),治疗后组较对照组下降(P<0.05)。结论 BV患者阴道局部免疫功能发生了改变;乳杆菌活菌制剂对BV患者阴道局部免疫具调节作用.     

Tube gel isotachophoresis: A method for quantitative isolation of nucleic acids from diluted solutions

The technique of isotachophoresis is intended for separation of molecules having different electrophoretic mobilities in a nonhomogeneous electric field. Since the mobility of nucleic acids in water solutions is uniform and does not depend on their size (because of a uniform distribution of negatively charged phosphate groups along the molecule), isotachophoresis will concentrate rather than separate them in the mobile borderline zone between the rapid (Cl⁻) and the slow (β-alanine⁻) anions. This idea served as the basis for elaboration of a novel method for isolation of nucleic acids from diluted solutions. Advantages of the method include quantitative yield (regardless of molecule size), high degree of concentration, and the ability to visually monitor the process. The method may find applications in nucleic acid isolation from highly degraded forensic and clinical samples, from bodily fluids in particular, and thereby promote development of this important direction of diagnostics.     

A simple method for large-scale purification of nucleic acids from plants using calcium phosphate-type monetite

Curently, the literature describes several nucleic acids purification methods, depending on the application and the required level of purity. These methods range from simple to complex and are mostly adapted for relatively small scale preparations. As an alternative, we developed in the present work an efficient, rapid, and up-scalable nucleic acids purification method based on the synthesis of a solid Calcium Phosphate-Type Monetite support (CPTM). The synthesis of the CPTM was optimized with regards to the calcium/phosphate (Ca/P) ratio and to sonication parameters (amplitude and time), and phase purity was resolved using X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Analysis revealed the crystalline purity of the monetite phase and the identity of the matrix, and showing no secondary phases. Nucleic acids adsorption to the CPTM matrix was assessed under optimal conditions of buffering, ionic strength, pH, and flow rate, and the elution was carried out through a phosphate ions gradient that allowed an earlier elution of contaminants. We applied this purification method on several plants material, and results demonstrate that CPTM is a good matrix for nucleic acids purification from complex biological and environmental samples     

Potentiometric characterization of ethidium bromide and of its reactions with nucleic acids

A liquid membrane electrode that allows the concentration of ethidium ion (Ed(+)) to be measured selectively and accurately in the range of 0.1 microM to 5 mM is made. For Ed(+) concentrations less than 1 microM or more than 0.1 mM, the trend is no longer linear, and the causes of this behavior are discussed. The mean activity coefficient of ethidium bromide exhibits deviations from the Debye-Huckel limiting law that are interpreted in terms of aggregate formation. The stability constants for Ed(2)(2+) and Ed(2)Br(+) are 230 kg mol(-1) and 3.0 x 10(4) kg(2) mol(-2), respectively. In NaCl solutions, clusters involving up to 4 Ed(+) units are detected and their stability constants are evaluated. The intercalation of ethidium into poly(A).poly(U) in 1M NaCl is investigated by the above electrode, and the results are compared with those obtained by spectrophotometry. The data are analyzed in terms of Scatchard plots. The potentiometric method is more accurate than the spectrophotometric one at low values of the binding degree (r) where negative deviations from linearity are observed. The deviations are ascribed to a cooperative behavior rather than to artifacts caused by minor systematic errors.