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1.
白藜芦醇生物学活性研究进展   总被引:1,自引:0,他引:1  
白藜芦醇是一种植物抗毒素,主要存在于虎杖、葡萄及花生等有限的植物中,它具有对人体有益的生物学活性,如具有拮抗肿瘤作用、心血管保护作用、抗炎作用、抗病毒作用、神经保护作用、植物雌激素作用和对骨钙的影响等。  相似文献   

2.
提出了以蜡状芽孢杆菌与金矿化作用及有机质、流体矿化系统协同演化作用机制,认为生物矿化作用是随着其他地质作用的发展而不断发展和演化的过程.阐述生物-蜡状芽孢杆菌、有机质、流体矿化及生物矿化作用演化机制,从而把构造演化与生物矿化作用结合起来研究.主要介绍有机流体的主要来源,着重探讨生物矿化作用子系统,其中包括活生物体的作用,有机质的作用及有机流体的相互作用机制.  相似文献   

3.
本通过对目前关于真核基因表达调控方面研究成果的综合分析,提出了真核基因转录的十种负调控机理,即竞争作用、复制作用、隔离作用、隐蔽作用、沉默作用、变构作用、修饰作用、锁合作用、反义作用及转座作用,并引证进行了初步讨论。  相似文献   

4.
非蛋白氨基酸的生物合成及其生物学作用   总被引:3,自引:0,他引:3  
解释了蛋白氨基酸和非蛋白氨基酸,并着重论述了非蛋白氨基酸的生物合成及其生物学作用。非蛋白氨基酸的生物合成主要通过基本氨基酸合成后的修饰、代谢及消旋作用产生,其生物学作用主要表现在能合成其他含氮物质、储藏氮和运输氮、储能、组成细菌细胞壁、毒性作用及药物作用等方面。  相似文献   

5.
植物化感作用的强弱与化感物质的作用浓度相关。化感作用全区间抑制强度指数(Whole-range assessment index)是用于评估植物在一定的化感物质作用范围内所受化感作用总体抑制程度的一种方法。在对非线性剂量响应进行曲线拟合的基础上,本研究应用蒙特卡罗模拟法为计算化感作用全区间抑制强度指数提供了一种科学的数学计算方法,并应用该计算方法分析了番茄水浸提液对生菜、萝卜、白菜、菜心、包心菜、豆角和水稻的化感作用强度。  相似文献   

6.
栀子的综合开发与利用   总被引:9,自引:0,他引:9  
综述了近10年来栀子的研究和综合开发利用情况.中药栀子对消化系统中具明显的胆囊收缩作用和排石利胆作用,对重症急性胰腺炎大鼠具明显的降脂质过氧化物作用和增强胰腺炎时机体的免疫能力.具有保护肝脏和抑制肝癌细胞作用以及对胃机能呈抗胆碱性的抑制作用;在心血管系统中具中枢降压作用、防治动脉粥样硬化及抗血栓作用;还具有中枢镇静镇痛解热作用、抗炎和治疗软组织损伤作用等;栀子中京尼平苷制成的新型复方农业增产剂应用前景广阔;栀子黄色素、栀子蓝色素在食品、医药、饲料、化妆品等行业有广泛的应用;另外对栀子花头香及栀子花精油的研究也有着重要的现实意义.  相似文献   

7.
微生态制剂的临床研究现状   总被引:1,自引:0,他引:1  
在简述微生态制剂的类型和菌种的基础上,从屏障作用、营养作用、免疫调节作用、抗肿瘤作用等方面综述了微生态制剂的作用机制和微生态理论,并从预防治疗各种腹泻、结肠癌、动力障碍性疾病、肝硬化以及某些自身免疫性疾病等方面综述了微生态制剂在临床上的应用,继而指出了应用注意事项,展望了前景。  相似文献   

8.
水稻化感作用的机制与应用的研究进展   总被引:1,自引:0,他引:1  
水稻是我国的主要粮食作物,其与周围植物的相生相克作用(化感作用)得到越来越多的重视.简要介绍了近来国内外对水稻对高等植物的化感作用的研究成果,介绍其化感作用途径、化感物质的分离、鉴定、可能的作用原理及在生产实践中的应用.  相似文献   

9.
花椒总生物碱镇痛、抗炎、止痒作用研究   总被引:1,自引:0,他引:1  
目的:研究花椒生物碱镇痛、抗炎及止痒作用。方法:分别采用热板法考察其镇痛作用二甲苯致炎法考察其抗炎作用、低分子右旋糖酐-40诱发小鼠皮肤瘙痒研究其止痒作用。结果:中、高浓度的花椒生物碱对小鼠热刺激引起的疼痛具有较强的镇痛作用;高浓度的花椒生物碱能较强抑制二甲苯所致小鼠耳肿胀,并能缓解分子右旋糖酐-40诱发的小鼠皮肤瘙痒。具有较强的抗炎、止痒作用。结论:花椒生物碱具有较强的镇痛、抗炎、止痒作用。  相似文献   

10.
■的15株外生菌根真菌在琼脂平板上对6株植物病原菌的拮抗作用试验结果表明,美味红菇、劣味乳菇、毛边滑锈伞、大毒滑锈伞等菌根菌对试验病原菌的营养菌丝具有明显的拮抗作用。菌根菌的培养液中含有抑制根病原菌的活性物质,且对高温稳定。外生菌根菌在纯培养条件下对病原菌的拮抗作用包括菌丝体对峙生长作用,重寄生作用和拮抗活性物质作用。其中菌丝体的重寄生作用在抗病效应中起重要作用。  相似文献   

11.
Indirect immunofluorescence technique with anti-17-39ACTH and anti beta-endorphin sera has allowed us to detect "corticotropic cells" in the anterior and intermediate lobes of the adenohypophysis of the male cat. The corticotropic cells of the anterior lobe are localized in the median zone; they are PAS-positive and appeared intensively coloured in dark blue with the Herlant's tetrachrome. All the cells of the intermediate lobe react with the anti-17-39ACTH serum. Using an anti-beta-endorphin serum, we have observed that all the corticotropic cells of the anterior lobe react; but in the intermediate lobe, only a part of "corticotropic cells" react with the anti-beta-endorphin serum.  相似文献   

12.
A bifunctional chelator 6 was prepared bearing an N2S2 core for binding rhenium or technetium and a carboxylic acid group for conjugation to amino groups of biomolecules. Complexation of 6 with rhenium(V) resulted in two kinetic isomers, anti-7 and syn-7, being formed in approximately equal amounts. Epimerization with 0.5 M NaOH yields a single isomer anti-7, as determined by NMR spectroscopy and single-crystal X-ray analysis. The 99mTc complex was prepared at the tracer level by reaction of the ligand with 99mTcO4-, tin(II) chloride and sodium gluconate giving a mixture of two isomers, but showing a preference for the anti isomer. Chelation in the presence of 1 M NaOH results in anti-8 being formed as the sole product. The bifunctional ability of the ligand was explored by amide formation with (S)-alpha-phenethylamine, either by direct DCC coupling or through the N-hydroxy succinimidyl ester 9 intermediate. The deprotected bioconjugate 11 was complexed with rhenium, yielding similar amounts of two isomeric rhenium complexes, anti-12 and syn-12, which were isolated and characterized by NMR spectroscopy. Treatment of the kinetic mixture of anti-12 and syn-12 with 1 M NaOH resulted in quantitative conversion to a single rhenium complex anti-12. With technetium-99m in 0.1 M sodium acetate, bioconjugate 11 yielded both technetium-99m complexes anti-13 and syn-13, in a 2:1 ratio, respectively. In contrast, complexation in the presence of 1 M NaOH gave only one technetium-99m complex, assigned the structure anti-13.  相似文献   

13.
Seven fungi, which are found to reduce ethyl 3-oxobutanoate in high yields, were tested for their reducing ability for ethyl 2-methyl 3-oxobutanoate. We obtained some interesting findings. In particular, Penicillium purpurogenum reduced ethyl 2-methyl 3-oxobutanoate to the corresponding alcohols with the diastereomer (anti/syn) ratio of 93/7 with the enantiomeric excess of anti-(2S,3S)- and syn-(2S,3R)- hydroxy esters of 90 and >99 ee%, respectively.  相似文献   

14.
Previous purification studies of the 1,4-dihydropyridine receptor associated with the calcium channel of rabbit skeletal muscle had shown that it is composed of a large glycoprotein of Mr 140,000-145,000 associated with a smaller component of Mr 32,000-34,000. Specific antisera have now been prepared against the larger component (anti-140 serum) and the smaller one (anti-32 serum). The specificity of these two antisera has been analyzed by immunoblot assays with microsomal preparations of rabbit skeletal muscle. Under disulfide-reducing conditions the anti-140 serum specifically labeled a polypeptide of Mr 140,000 while the anti-32 serum labeled three polypeptides of Mr 32,000, 29,000, and 26,000. Under nonreducing conditions both the anti-140 and the anti-32 sera specifically recognized a single large polypeptide of Mr 170,000. The same type of approach showed that the dihydropyridine receptor in cardiac and smooth muscles had a polypeptide composition similar to that found in skeletal muscle with a large polypeptide of Mr 170,000-176,000 made of two different chains of about Mr 140,000 and 34,000-32,000 associated by disulfide bridges.  相似文献   

15.
Since some of the conserved antigens between man and phylogenetically lower primate species may be more immunodominant on lymphocytes of the lower primate species, we reasoned that immunization of mice with lymphocytes from lower primates might prove a useful strategy for developing monoclonal antibodies which recognize functionally important structures on both human and nonhuman primate lymphocytes. In employing this approach for the development of monoclonal antibodies, we have developed the antibody anti-2H4 which recognizes a structure on both T on non-T mononuclear cells of a wide array of primate species. 2H4+ rhesus monkey T lymphocytes exhibited a greater proliferative response to lectin and alloantigenic stimulation than 2H4- cells, suggesting that anti-2H4 might separate primate T lymphocytes into functionally distinct cell populations. In fact, helper activity for antibody production by rhesus monkey B lymphocytes in response to pokeweed mitogen (PWM) resided in the 2H4- T-cell population. Furthermore, the 2H4+ T-lymphocyte population activated the suppressor function of T8+ rhesus monkey cells. The fact that the surface antigen which defines this T-cell subset is widely conserved in nonhuman primates suggests that anti-2H4 recognizes a functionally important structure.  相似文献   

16.
Immunological properties of gap junction protein from mouse liver   总被引:9,自引:0,他引:9  
Hepatic gap junctions were purified as plaques from BALB/c mice and separated by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS). Antisera were raised in rabbits and rats against gap junction plaques as well as protein bands of the following apparent molecular weights: 44K to 49K ("dimer" proteins), 26K, and 21K. Using an enzyme immunoassay, we found that the reactivities of the different antisera towards gap junction plaques decreased in the following order: anti-plaque antisera, anti-26K antisera, anti-"dimer" protein antisera, and anti-21K antisera. The gap junction protein bands separated by SDS-polyacrylamide gel electrophoresis were transferred by blotting onto nitrocellulose paper and the immunological cross-reactivities were compared: the anti-26K antisera reated with the dimer protein bands and the 26K band but did not cross-react with the 21K protein band. The rabbit anti-21K antiserum reacted weakly with the 21K protein. The missing immunological cross-reaction of the 26K and the 21K protein band can be most easily explained if both proteins were independent of each other. No inhibition of metabolic cooperation between fibroblastoid mouse 3T6 cells was observed in the presence of Fab fragments prepared from rabbit antiplaque antiserum or from rabbit anti 26K antiserum. When the total proteins of plasma membranes from mouse liver were separated by SDS-polyacrylamide electrophoresis, only the 26K protein reacted with rabbit anti 26K antiserum. This result opens the possibility for direct quantitation of gap junction protein in tissues and cell fractions.  相似文献   

17.
目的:研究自身免疫性疾病患者抗2GP1抗体水平和抗t-PA抗体水平之间的关系。方法:用酶联免疫吸附法(ELISA)检测原发性抗磷脂综合症和红斑狼疮患者(32个狼疮样抗凝物阳性,32个狼疮样抗凝物阴性)与40例健康对照的IgG类抗2GP1和抗t-PA抗体的水平,用竞争ELISA的方法研究抗2GP1抗体与t-PA的互作。结果:64个病人中有8个IgG类抗2GP1和抗t-PA抗体共存,并且这两种抗体的共存和血栓病史显著相关(P=0.02)。我们还发现两个来自病人的抗2GP1抗体能和t-PA交叉互作。但是,在这些病人群体中未发现这两种抗体显著相关。结论:病人体内可能存在能和t-PA交叉互作的抗2GP1抗体。  相似文献   

18.
HBV感染中抗-(抗-HBs)独特型抗体的研究   总被引:1,自引:0,他引:1  
1.75%聚乙二醇(MW6000)沉淀血清免疫复合物后,采用ELISA法检测上清中抗独特型抗体〔抗-(抗-HBs)〕。56例急性HBV感染患者血清IgM抗-(抗-HBs),第一周检出率最高(60.00%),1个月后大部分阴性,IgG抗-(抗-HBs)维持时间略长。IgM抗-(抗-HBs)较HBsAg/IgM和IgM抗-HBc消失早,将有利于急性HBV感染的诊断。27例CAH和29例CPH,IgM和IgG抗-(抗-HBs)阳性率约为38~52%,两型间无显著差异(p>0.5)。3例无症状HBsAg携带者和12例HBsAg血清疫苗接受者血清,抗-(抗-HBs)阴性。115例HBV感染者中,IgM抗-(抗-HBs)阳性者HBsAg阳性率(93.62)显著高于IgM抗-(抗-HBs)阴性者(52.31%),p<0.005;反之,HBsAg阳性血清IgM抗-(抗-HBs)阳性率(55.5S%)显著高于HBsAg阴性血清(9.68%),p<0.005;IgM抗-(抗-HBs)阳性和阴性血清的HBVDNA阳性率有显著差异(p<0.025),IgG反应到类似的结果。以上资料表明,抗-(抗-HBs)提示了一些HBV感染患者体内可能存在一种缺陷的反馈机制,导致抗-HBs产生不足而容许更活跃的HBV复制。本文证明了HBV感染患者血清中存在的抗-(抗-HBs)可能是共同决定簇“a”特异性的,还表明抗-HBs人抗-Id反应可能被纯化人血清HBsAg抑制,提示人抗-(抗-HBs)与抗-HBs结合的位点可能在HBsAg与抗-HBs结合位点内或在其附近,这和一些动物抗-(抗-HBs)的研究结果是一致的。  相似文献   

19.
Cells from mice immune against soluble antigens were tested for their in vitro cytotoxicity against chicken red blood cells (CRBC) coated with these antigens. In parallel, cells from mice immune against allogeneic P815 mastocytoma cells were tested for their in -vitro cytotoxicity against P815 cells. Before the cytotoxicity test, the immune cell populations were fractionated, using four different types of techniques, to check the impact of the removal of given subpopulations of cells on cytotoxic activity.Fractionation on anti-immunoglobulin coated columns did not affect the anti P815 cytotoxicity, but markedly decreased the cytotoxicity against antigen-coated CRBC. The same results were obtained by incubation on a plastic surface and/or an “ironplus-magnet” technique. Preincubation of the cytotoxic cell populations with homologous anti-θ or heterologous anti-T antiserum, plus complement, abolished both types of cytotoxicity. However, preincubation with anti-θ or anti-T antiserum alone, without complement, also blocked the cytotoxicity against antigen-coated CRBC, but not the anti P815 cytotoxicity. In vivo injection of heterologous anti-lymphocyte gammaglobulin completely abolished the anti P815 cytotoxicity, but not the cytotoxicity against antigen-coated CRBC.These results confirm that T cells (thymus-processed lymphocytes) can kill autonomously in the anti P815 system. They also suggest that, in the cytotoxicity against antigen-coated CRBC, as effector cells, (1) non-T cells are involved, (2) T cells might not be involved.  相似文献   

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