胸腺素对增强Sarcoma180小鼠免疫力的研究

本文报道小鼠荷瘤后,随肿瘤细胞的增长,瘤鼠体重、瘤重、脾重及脾细胞数/克,胸腺重及胸腺细胞数/克,有丝分裂指数的变化,并用~3H-TdR掺入法测定胸腺淋巴细胞在ConA作用下的淋转反应,从酵母多糖混合玫瑰花形成试验观察胸腺淋巴细胞亚群的动态变化;同时,观察外源性胸腺素在胸腺淋巴细胞增殖速度和抑癌观察中的作用,结果表明:外源性胸腺素对S_(180)小鼠胸腺淋巴细胞具有增殖作用,并提高瘤鼠免疫力,从而抑制瘤细胞的增殖。     

胸腺素对荷瘤小鼠胸腺淋巴细胞有丝分裂指数影响的研究

本文报道胸腺素对荷瘤小鼠胸腺淋巴细胞有丝分裂指数的影响。实验结果表明,注射胸腺素的实验组胸腺淋巴细咆有丝分裂指数均高于对照组,其中不同瘤龄之间有一定差异。     

龙葵多糖对荷瘤小鼠脾指数和胸腺指数的影响

研究龙葵多糖对荷瘤小鼠脾指数和胸腺指数的影响,从免疫学角度初步探讨龙葵多糖的抗肿瘤药效学作用.实验采用MTT法观察龙葵多糖对Hep G-2和SGC-7901两种人肿瘤细胞的生长抑制作用.测定S180小鼠瘤重,H22荷瘤小鼠生存时间以及胸腺指数、脾指数等.实验结果表明龙葵多糖对Hep G-2细胞和SGC-7901细胞的IC50分别为189.60μg/m L和186.56μg/m L.龙葵多糖能够显著降低S180荷瘤小鼠平均瘤重,与阴性对照组比较具有显著性差异(P0.01),龙葵多糖能明显延长H22荷瘤小鼠的生存时间(P0.05或P0.01),显著提高荷瘤小鼠的胸腺指数和脾指数(P0.05或P0.01).表明龙葵多糖的肿瘤作用是通过改善机体免疫力实现的,而不是通过细胞毒作用发挥的.     

超强静磁场对小鼠抗氧化和免疫功能的影响

研究超强静磁场对一周龄小鼠抗氧化和免疫功能的影响.采用磁感应强度为12 T的超强静磁场分别照射小鼠8,12,16 h,照射结束后6,12,24 h,分别取肝脏检测过氧化氢酶（CAT）、谷胱甘肽过氧化物酶（GSH-Px）的活力和丙二醛（MDA）含量,取胸腺和脾脏,测定胸腺、脾脏指数和脾淋巴细胞增殖率.结果表明,超强静磁场可以显著提高小鼠肝脏的CAT和GSH-Px的活力,降低MDA含量,提高机体处理自由基的能力,减少脂质过氧化产物的生成;磁场显著提高小鼠的脾淋巴细胞增殖率,脾脏和胸腺指数也有所升高.试验表明,超强静磁场可以提高机体的抗氧化能力和免疫功能,从而增强机体抗病能力,对延缓衰老有积极作用.     

壳寡糖抗肿瘤和免疫调节作用的实验研究

研究壳寡糖抗肿瘤的作用和免疫调节作用.应用SRB法对壳寡糖进行体外抗肿瘤作用研究,对S180荷瘤小鼠的瘤重和胸腺及脾指数进行了的观察,同时观察了壳寡糖体外对小鼠腹腔巨噬细胞吞噬中性红能力的影响.壳寡糖体外对肿瘤生长的抑制作用不明显,体内实验表明壳寡糖能抑制S180小鼠的瘤重.壳寡糖能显著提高荷瘤小鼠的胸腺指数和脾指数.壳寡糖体外实验能提高小鼠腹腔巨噬细胞吞噬中性红的能力.提示壳寡糖有可能是通过调节荷瘤小鼠免疫力实现抗肿瘤作用的.     

扶正升血颗粒对荷H22瘤小鼠免疫功能影响的实验研究

目的:通过观察扶正升血颗粒对荷H22瘤小鼠免疫器官(胸腺、脾脏)重量、脾淋巴细胞增殖活性及细胞因子(IL-2)分泌的影响,探讨扶正升血颗粒对荷瘤小鼠免疫系统的调节作用.方法:采用荷H22(肝癌)实体瘤小鼠模型,用免疫器官重量法计算胸腺指数(TI)和脾脏指数(SI),用MTT比色法测定淋巴细胞增殖反应,用双抗体夹心ELISA法测定脾淋巴细胞培养上清液中IL-2的浓度.结果:扶正升血颗粒大、中、小剂量组荷瘤小鼠胸腺指数、脾脏指数均高于模型组,其中大剂量组TI、SI分别为18.9mg/10g、76.3mg/10g,较模型组分别增长36.0％、17.9％(p＜0.05);中剂量组TI为18.0mg/10g,较模型组增长29.5％(p＜0.05).扶正升血颗粒各剂量组荷瘤小鼠脾淋巴细胞增殖活性均高于模型组,以大剂量组作用最优,与模型组比较有显著性差异(p＜0.05).扶正升血颗粒各剂量组小鼠脾淋巴细胞培养上清液中IL-2的浓度均较模型组增高,大剂量组IL-2的浓度为61.6pg/ml,与模型组比较有显著性差异(p＜0.05).结论:扶正升血颗粒对荷H22瘤小鼠免疫器官胸腺、脾脏具有增重作用,能够增强脾淋巴细胞增殖活性,促进荷瘤小鼠细胞因子IL-2的分泌,表明扶正升血颗粒能明显增强荷瘤小鼠机体的免疫功能.     

沼泽红假单胞菌对小鼠免疫功能影响的试验研究

为探讨沼泽红假单胞菌对动物免疫功能的影响,采用不同菌液浓度的沼泽红假单胞菌饲喂小鼠,检测小鼠免疫器官(脾脏和胸腺)实质重量、巨噬细胞吞噬能力、外周血淋巴细胞转化率以及肠黏膜SIgA等指标,分析沼泽红假单胞菌对试验小鼠免疫功能的影响.结果显示,饲喂沼泽红假单胞菌可促进小鼠的体重增长,脾脏和胸腺的重量增加(P0.05);促进机体巨噬细胞吞噬率、淋巴细胞转化率以及肠黏膜SIgA的变化(P0.05).结论:采用沼泽红假单胞菌饲喂小鼠可提高其机体的免疫能力.     

文蛤多肽粉对人肝癌细胞SMMC-7721的抑制作用及免疫调节作用

将文蛤肉以复合胰蛋白酶酶解,经喷雾干燥工艺得到了文蛤多肽粉,研究文蛤多肽粉对肝癌细胞的抑制作用和对昆明种小鼠的急性毒理作用和免疫调节作用,结果显示文蛤多肽粉对体外培养的肝癌细胞SMMC-7721具有明显的杀伤作用,使细胞变形以至破裂从而抑制癌细胞的生长,抗肿瘤作用明显;文蛤多肽粉给药组的胸腺指数和脾脏指数较空白对照组明显升高,提示文蛤多肽粉能促进小鼠胸腺和脾脏的生长发育,增强免疫力.     

老年人的自我保健与肝肾的关系

机体的免疫系统有抵抗外来病原微生物侵袭的防御作用和监视、杀灭体内出现的癌变细胞、清除体内衰老死亡细胞的功能,也即免疫监视和免疫自稳作用。衰老而病往往由于人体免疫力逐渐降低导致的结果。随着年龄的老化,人体各系统器官功能也随之退化,中枢性免疫器官胸腺萎缩,继而人体内具有免疫活性的 T 淋巴细胞减少,专门杀死癌细胞的自然杀伤细胞数量和功能也会相应改变。于是,机体对细菌、病毒感染的防御能力下降,易患各种感染性疾病,且一旦感染,病程迁     

外源性补充Tα1对运动性免疫抑制发展过程中胸腺组织细胞的抗凋亡效应

研究了补充Tα1(胸腺素α1)对大鼠胸腺形态、结构与淋巴细胞凋亡的影响,分析了补充Tα1后改善运动性免疫抑制(Exercise-induced immunosuppression)的机制。将雄性SD大鼠48只,分为单纯运动组和运动+Tα1组。运动方案采用6周活动跑台递增负荷运动,分别在第0、2、4、6周末次运动后48h取材。结果发现,单纯运动组大鼠胸腺形态不断萎缩,胸腺结构发生进行性破坏,且细胞凋亡显著增加。补充Tα1后,大鼠胸腺形态结构明显改善,细胞凋亡情况显著降低。补充Tα1能够保护胸腺形态结构的完整性,减少胸腺细胞凋亡,有效提升机体的抗氧化能力,改善运动免疫抑制的程度。     

羊栖菜多糖对荷瘤小鼠红细胞膜Na+,K+-ATPase活性的影响

报道了羊栖菜多糖 （SFPS）对S180A小鼠,EAC小鼠,L615 小鼠红细胞膜Na+,K+-ATPase的活性的影响。结果表明：SFPS能明显抑制S180A小鼠,EAC小鼠,L615小鼠红细胞膜Na+,K+-ATPase的活性。本文结果提示,SFPS 的这一作用可能是其促进荷瘤小鼠红细胞免疫功能的机理之一。     

Phenotypic differences between alpha beta versus beta T-cell receptor transgenic mice undergoing negative selection

T-cell differentiation in the thymus is thought to involve a progression from the CD4-CD8- phenotype through CD4+CD8+ intermediates to mature CD4+ or CD8+ cells. There is evidence that during this process T cells bearing receptors potentially reactive to 'self' are deleted by a process termed 'negative selection' One example of this process occurs in mice carrying polymorphic Mls antigens, against which a detectable proportion of T cells are autoreactive. These mice show clonal deletion of thymic and peripheral T-cell subsets that express the autoreactive V beta 3 segment of the T-cell antigen receptor, but at most a two-fold depletion of thymic cells at the CD4+CD8+ stage. By contrast, transgenic mice bearing both alpha and beta chain genes encoding autoreactive receptors recognizing other ligands, show severe depletion of CD4+CD8+ thymocytes as well, suggesting that negative selection occurs much earlier. We report here the Mls 2a/3a mediated elimination of T cells expressing a transgene encoded V beta 3-segment, in T-cell receptor alpha/beta and beta-transgenic mice. Severe depletion of CD4+CD8+ thymocytes is seen only in the alpha/beta chain transgenic mice, whereas both strains delete mature V beta 3 bearing CD4+ and CD8+ T cells efficiently. We conclude that severe CD4+CD8+ thymocyte deletion in alpha/beta transgenic mice results from the premature expression of both receptor chains, and does not reflect a difference in the timing or mechanism of negative selection for Mls antigens as against the allo- and MHC class 1-restricted antigens used in the other studies.     

Thymocyte subpopulation enriched for progenitors with an unrearranged T-cell receptor beta-chain gene

The development of T cells within the thymus is not well understood. It is known that thymocytes are derived from a progenitor cell in the bone marrow, the prothymocyte, and that cells in the subcapsular area of the thymus can give rise to progeny in both the cortex and the medulla. However, it is not clear whether all medullary thymocytes are necessarily derived from cortical cells. In particular, it has been difficult to distinguish intrathymic progenitor cells. Recently, however, Lesley et al. have defined a thymocyte subpopulation which can be isolated by treatment of the thymus with cytotoxic anti-Thy-1 antibodies and that seems to be enriched for thymocyte progenitors as measured first by its ability to repopulate transiently the thymus of an irradiated host, and second, by its high content of cells bearing Pgp-1 (refs 10, 11), a cell-surface glycoprotein of relative molecular mass 95,000 that is present on most or all prothymocytes of the bone marrow and on fetal thymocytes, but on only a few per cent of cells in the adult thymus. We show here that the gene encoding the beta-chain of the T-cell receptor for antigen, which is rearranged during T-cell ontogeny, is predominantly in the germline configuration in these cells.     

钙调素拮抗剂对荷瘤小鼠主要器官钙调素（CaM）水平的影响

本文采用磷酸二酯酶（ＰＤＥ）法,测定了小檗胺衍生物ＥＢＢ对荷Ｓ１８０瘤小鼠的主要器官和瘤体ＣａＭ含量的影响。实验结果表明,ＥＢＢ具有使荷瘤后小鼠脑、肺、肝、脾、肾五个主要器官ＣａＭ由不正常趋向正常的能力,而已知抗肿瘤药物丝裂霉素和环磷酰胺单独使用时此种能力较弱,但这两种抗肿瘤药物与ＥＢＢ联合作用时,能使荷瘤鼠诸器官的ＣａＭ水平趋向正常。结果提示,专一性强的ＣａＭ拮抗剂在抑制肿瘤的同时可能还具有维护     

The generation of mature T cells requires interaction of the alpha beta T-cell receptor with major histocompatibility antigens

THE T-cell repertoire within an individual is biased to recognize antigen in the context of self major histocompatibility complex (MHC) antigens. This is thought to depend on a process of positive selection during development. Support for this notion has recently been obtained in experiments using transgenic mice bearing genes for T-cell receptors (TCR) of defined specificity: T cells expressing the introduced genes form the main part of the mature T-cell population only in mice that express the appropriate MHC product. We have now extended these observations using TCR transgenic mice homozygous for the severe combined immunodeficiency (SCID) mutation which are defective in the rearrangement of both TCR and immunoglobulin genes. In this case mature thymocytes develop only in transgenic mice that express the MHC product which restricts the specificity of the transgenic TCR. This shows that the interaction of the alpha beta TCR with thymic MHC antigen is essential for the development of mature T cells. Furthermore, the peripheral lymph nodes of such mice are underdeveloped, suggesting that the peripheral expansion of mature T cells may require interactions with other lymphocytes expressing a range of receptors.     

维生素E对小白鼠骨髓细胞染色体畸变效应的实验研究

灌胃有毒源污水或皮下注入苯诱发小白鼠骨髓细胞染色体畸变率分别为4.0%和5.0%,4h后灌胃维生素E,染色体畸变率分别下降为1.0%和1.5%,P相似文献   

造血重建小鼠骨髓中成纤维细胞的起源

选择Y染色体特异的性别决定基因(Sry)作为新的细胞遗传标志,采用PCR技术对小鼠骨髓细胞重建造血的性能和造血重建小鼠骨髓中成纤维细胞的起源进行研究.将正常雄鼠骨髓细胞输注给经致死剂量射线照射的受体雌性小鼠,PCR技术检测结果表明,在活存小鼠的骨髓、脾脏、胸腺和淋巴结中均具有供体起源的细胞.而正常雄鼠或5-氟尿嘧啶处理的雄鼠骨髓细胞输注给受体雌性小鼠后,造血重建小鼠骨髓中的成纤维细胞则为受体起源.由此可见,小鼠骨髓中的成纤维细胞与造血细胞具有不同的起源.     

Participation of CD4 coreceptor molecules in T-cell repertoire selection.

During thymocyte development, progenitor cells bearing both CD4 and CD8 coreceptor molecules mature into functional T lymphocytes that express these proteins in a mutually exclusive way. Although T-cell specificity is determined primarily by the structure of the T-cell antigen receptor (TCR) heterodimer, a developmentally regulated process acts to ensure that cells bearing class II-restricted TCRs are CD4+ and those bearing class I-restricted TCRs express only CD8. To investigate this maturation process, we have engineered transgenic mice in which CD4 is expressed in all thymocyte subsets and in all peripheral T cells. Peripheral CD4+8+ T lymphocytes from these mice react with both class I and class II alloantigens. Moreover, expression of the CD4 transgene disrupts the positive selection of doubly transgenic thymocytes bearing a class I-restricted TCR specific for the male (H-Y) antigen. Hence the CD4 coreceptor participates directly in T-cell repertoire selection.