胃癌病人NK细胞活性变化机理的初步研究

应用~(51)Cr释放试验和效靶结合试验,同时测定了正常人和胃癌病人外周血NK细胞活性与靶结合细胞数(TBC),研究了正常人及病人血浆对NK细胞功能的影响。发现正常人NK细胞活性与靶结合细胞数之间的关系呈直线正相关,但在NK活性降低的病人中靶结合细胞数却无明显改变,二者无相关性,而病人的血浆对正常人外周血NK活性则有明显的抑制作用(P<0.05),且抑制率与胃癌人NK细胞活性存有着负相关的关系,提示胃癌病人血浆具有抑制NK细胞活性的物质。     

辛伐他汀对CD40L介导的ECV-304细胞E选择素表达及粘附功能的影响

目的研究在人脐静脉内皮细胞中3-羟-3-甲基戊二酰辅酶A(HMG-CoA)还原酶对CD40/CD40L系统介导的粘附分子表达的影响,及对淋巴细胞与内皮细胞的粘附功能的影响。方法采用人脐静脉内皮细胞株ECV-304,CD40L干预,使之与其表面的CD40作用,用不同浓度辛伐他汀或辛伐他汀(5μmol.L-1)+甲羟戊酸干预,流式细胞术和RT-PCR检测干预前后E选择素(E-Selectin)的表达,流式细胞术检测CD40L介导的淋巴细胞与内皮细胞的粘附功能。结果不同浓度辛伐他汀可下调CD40L介导的E-Selectin的表达,并呈一定的剂量依赖性。甲羟戊酸(400μmol.L-1)抑制了辛伐他汀(5μmol.L-1)对E-Selectin表达的下调作用。辛伐他汀可降低CD40L介导的淋巴细胞与内皮细胞的粘附功能。结论他汀类药物的抗炎作用与抑制CD40-CD40L系统有关,其机制是通过抑制HMG-CoA还原酶而发挥作用的。     

Chronotropic and inotropic effects of histamine in developing chick heart: differential mechanisms before and after hatching

Chronotropic and inotropic effects of histamine were examined in isolated atrial and ventricular preparations from embryonic and hatched chicken hearts. Histamine produced positive chronotropic and inotropic responses both in embryonic and hatched hearts. The responses to histamine in middle embryonic myocardia, which were observed in the micromolar range, were antagonized by H₂ antagonists but not by H₁, H₃ antagonists and propranolol. Isobutylmethylxantine, an inhibitor of phosphodiesterase, produced a leftward shift of the concentration-response curve for the chronotropic effect of histamine in the embryo. The responses to histamine in myocardia from hatched chicks, which were observed in the milimolar range, appeared concurrently with the responses to tyramine during development and were antagonized by beta adrenoceptor antagonists but not by any of the histamine antagonists. The positive inotropic response to histamine in hatched ventricular preparations were greatly attenuated by reserpine pretreatment or in the presence of desipramine. Thus, we demonstrated that exogenously applied histamine produces positive chronotropic and inotropic responses in developing chicken hearts and that the mechanisms are different between embryonic and hatched chicks: direct action on H₂ receptors in the embryonic heart and release of norepinephrine from sympathetic nerve terminals in hatched hearts.     

核黄素等抗甲基苄基亚硝胺的致细胞突变作用

采用ＣＨＯ细胞ＨＧＰＲＴ位点突变测定系统观察了核黄素、尼克酰胺和锌等微量营养素对甲基苄基亚硝胺（ＭＢＮＡ）致细胞突变作用的影响。结果表明，在ＲＰＭＩ１６４０培养基中添加核黄素（２．６～１３．０μｍｏｌ／Ｌ）或尼克酰胺（４０～１２０μｍｏｌ／Ｌ）可显著抑制ＭＢＮＡ的致细胞突变作用。联合应用核黄素、尼克酰胺和锌效果更佳。提示：核黄素等微量营养素可能具有阻止细胞癌变的作用，为应用微量营养素干预治疗癌变过程提供了一定的理论依据。     

Synthesis and post-translational modification of the androgen receptor in LNCaP cells

Androgen receptor synthesis and modification were studied in the human LNCaP cell line. Immunoblotting with a specific polyclonal antibody showed that the androgen receptor migrated as a closely spaced 110–112 kDa doublet on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) gels. Most of the receptor protein is present in the higher molecular mass form. Pulse labelling experiments with [³⁵S]methionine showed that the androgen receptor is synthesized as a single 110 kDa protein which is rapidly converted to a 112 kDa protein. Alkaline phosphatase treatment of cytosols from [³⁵S]methionine pulse labelled cells caused a gradual elimination of the 112 kDa isoform with a concomitant increase of the 110 kDa isoform. This indicates that the observed 110 to 112 kDa upshift of the newly synthesized androgen receptor reflects receptor phosphorylation. Both isoforms can bind hormone and can undergo a hormone dependent transformation to a tight nuclear binding form, indicating that the 110 to 112 kDa conversion is not an obligatory step for hormone binding or receptor transformation.     

In Vitro Growth of Thymic Tumor Cell Lines from Xenopus

A spontaneous lymphoid thymus tumor was discovered in a male Xenopus of the MHC ff genotype. The tumor cell can be transplanted in histocompatible larval ff hosts, but not in ff adults unless irradiated (3000 rad). The tumor is rejected by allogeneic hosts. The tumor cells express neither markers of the B-cell lineage nor MHC encoded molecules; they express only markers of the T-cell lineage. Its lymphoid population is clonal as revealed by the existence of a stable rearrangement pattern of the immunoglobulin genes. Cell lines growing continuously in vitro have been derived from the tumor.     

在无血清培养基中代谢副产物对杂交瘤细胞生长代谢的影响 I.乳酸的作用

研究了无血清批培养中乳酸对杂交瘤细胞生长代谢的影响，当乳酸浓度低于5．3mmol/L时，乳酸对细胞生长和代谢无明显影响，当乳酸浓度在10mmol/L-25mmol/L时，对杂交瘤细胞的生长代谢有弱抑制，当乳酸浓度高于34mmol/L时，对细胞生长代谢有较明显的抑制。     

Cytoprotective effect of epidermal growth factor on acid- and pepsininduced damage to rat gastric epithelial cells: Roles of Na+/H+ exchangers

We have previously established a cell damage model, with damage induced by either acid or pepsin treatment for 30 min, involving a rat gastric epithelial cell line (RGM1). In the present study, pretreatment of cells with epidermal growth factor (EGF; 0.1–10ng/mL) or sucralfate (0.1–3 mg/mL) for 4 h prevented such cell damage in a concentration-dependent manner. Protection of cells by these drugs was not affected by pretreatment with indomethacin (10⁻⁵ mol/L) for 4 h. Removal of Na⁻, but not Ca²⁺, from the acidified medium totally abolished the inhibitory effect of EGF, but not that of sucralfate. Genistein (a tyrosine kinase inhibitor) apparently reduced the inhibitory effect of EGF. DNA synthesis by RGM1 cells did not increase when cells were incubated with EGF for 4 h. We conclude that both EGF and sucralfate protect RGM1 cells from acid- and pepsin-induced damage and that the mechanism of protection by EGF against acid-induced damage seems to be via activation of Na⁺/H⁺ exchangers.     

复合维生素对抗体形成细胞的影响

单独一种维生素缺乏对免疫功能的影响已有较多研究报道,但维生素缺乏一般不会单独发生,为此本实验研究了维生素A、E、B_2、B_6及叶酸供给不足(1/3生理需要量)、加倍补充(2倍和3倍生理需要量)后对小鼠抗体形成细胞的复合效应。动物喂养6周(不足纠正组喂8周),结果显示,不足组抗体形成细胞显著低于对照组,而2倍、3倍组则显著升高,不足组补充正常量维生素后,抗体形成细胞升高超过对照组,与2倍量组无显著差异;另外,该几种维生素对肝脏RNA、脾脏DNA、RNA及肝脏蛋白质均有明显影响,且抗体形成细胞的变化与核酸、蛋白质含量改变相平行,提示后者可能是维生素作用于体液免疫系统的生化机制。     

人HLA半相合混合脐血在SCID小鼠移植的实验研究

目的：探讨不同供者来源脐血混合移植的可行性和植入特性。方法：分别将两份人HLA半相合混合脐血或单份脐血输入经亚致量照射后的严重联合免疫缺陷（SCID）小鼠，观察两组脐血在SCID小鼠体内的植入状况及多系造血重建特性。结果：混合脐血和单份脐血移植均可在受鼠体内植入，形成供－受混合嵌合体，并能重建多系造血，存活率和植入率无统计学意义（P＞0．05）。用多聚酶链反应－序列特异性寡核苷酸（PCR－SSO）探针检测人HLA－DQB1基因发现，HLA半相合混合脐血移植可有1份或2份脐血植入，其中造血祖细胞含量和体外克隆形成能力高者，更易于植入，造血重建特性与单一脐血移植比较无统计学意义。结论：HLA半相合人混合脐血可同时在SCID小鼠体内植入，形成来自供－受三者的多嵌合状态，并能重建造血及免疫功能。