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991.
目的 :检测大肠癌组织中胀亡细胞及MMP - 2。方法 :应用透射电镜和免疫组化方法检测 5 1例大肠癌组织中胀亡细胞和MMP - 2的表达。结果 :①大肠癌组织中可检测到不同时期的胀亡细胞。②大肠癌组织中MMP- 2表达率 5 4 .9% (2 8/ 5 1 ) ,明显高于正常大肠粘膜 (P <0 .0 5 )。③MMP - 2在淋巴结转移组的阳性表达率为 6 9.5 7% (1 6 / 2 3) ,明显高于无淋巴结转移组的 4 2 .86 % (1 2 / 2 8) ;有淋巴结转移组胀亡指数明显低于无淋巴结转移组 (P<0 .0 5 )。④MMP - 2表达阳性组OI高于MMP - 2阴性组。结论 :大肠癌组织中存在胀亡细胞和MMP - 2的表达 ,2者关系密切 ,且均与大肠癌的转移有关。 相似文献
992.
Keratinocyte intercellular adhesion molecule (ICAM)-I expression is induced by interferon (IFN)-gamma. It has been previously reported that IFN-beta suppresses IFN-gamma-induced ICAM-I expression in A431 cells, a human squamous cell carcinoma cell line. In this study, the suppression mechanisms were investigated at the post second messenger level. Both 12-O-tetradecanoylphorbol-13-acetate (TPA) and calcium ionophore (A23187) induce ICAM-I expression in A431 cells. ICAM-I expression induced by either was not suppressed with cotreatment with IFN-beta. Furthermore, IFN-beta did not inhibit the translocation of protein kinase C (PKC) by TPA. It appears that the pathways involved in ICAM-I expression induced by activation of PKC or increased in intracellular Ca++ are not affected by IFN-beta. 相似文献
993.
目的:探讨联合应用成纤维细胞介导IL2和IL3的基因疗法对骨髓移植(BMT)后荷瘤小鼠抗肿瘤作用的效果及机理。方法:将分别转染IL2基因及IL3基因的NIH3T3细胞以单独或联合方式移植至BMT的荷瘤小鼠腹腔内8d后,取出小鼠骨髓细胞检测杀伤活性的变化以及IL2受体的表达,并观察荷瘤小鼠的存活期。结果:IL3基因治疗虽然可加速BMT后造血重建过程,但对骨髓细胞的NK、LAK活性具有一定的抑制作用;IL2基因治疗可明显提高骨髓细胞的杀伤活性;联合应用基因治疗后荷瘤小鼠骨髓NK、LAK活性及骨髓细胞CD25表达升高,明显延长大剂量化疗后接受BMT的荷瘤小鼠的存活期。结论:联合应用IL2和IL3的基因疗法能协同提高骨髓细胞IL2受体表达水平,提高骨髓细胞毒活性,增强BMT后的抗肿瘤效果。 相似文献
994.
锌离子对大鼠海马突触体Ca^2+—Mg^2+ATP酶活性及蛋白合成的影响 总被引:5,自引:0,他引:5
行为实验己经证明,锌过多或缺锌均可影响脑功能。锌作为体内重要的微量元素,影响多种酶的活性及蛋白质和核酸的台成。本实验通过体外分离大鼠脑海马突触体,观察不同浓度锌离子对Ca2 -Mg2 ATP酶的活性和3H-Leu掺入突触蛋白合成的影响.结果表明:1.锌离子浓度在25μmol/L时增加该酶的活性(<0.01),并促进3H-Leur掺入蛋白质的合成(<0.05)。2.锌离子在50,100,200μmol/L的较高浓度时对Co2 -M2 ATP酶的活性有显著的抑制作用(分别为:P<0.05.P<0.01,P<0.01),仅200μmol/L对3H—Leu掺入突触蛋白合成有抑制作用。本研究提示:适量的锌对突触体功能的维持是必要的,但剂量过高则起相反作用。 相似文献
995.
中国人丙型肝炎病毒囊膜蛋白2HVR1 cDNA的序列分析 总被引:1,自引:0,他引:1
目的:了解中国HCV流行株高变区1(HVR1)的特点。方法:对来自山东(SD)、上海(SH)两地患者血清RNA进行逆转录-巢式PCR,扩增HCV囊膜蛋白2基因片段,用PCR直接测序法对该片段进行序列测定。结果:(1)扩增片段(命名为P388)对应于日本HCV-J株序列核苷酸1439 ̄1826位(氨基酸位371 ̄498);(2)中国人HCV HVR1位于氨基酸位384 ̄410,与发表的HCVⅡ型HV 相似文献
996.
Csar O. García A. Kanbour-Shakir Hua Tang Jos F. Molina Luis R. Espinoza Azzudin E. Gharavi 《American journal of reproductive immunology (New York, N.Y. : 1989)》1997,37(1):118-124
PROBLEM: Immunization with β2-glycoprotein I (β2GPI) induces antiphospholipid antibodies (aPL) in normal mice and rabbits. Recently we reported early onset of autoimmunity in MRL/++ mice following immunization with β2GPI. There is a close association between aPL with thrombosis, recurrent fetal loss, and intrauterine growth retardation. In this study we evaluated the effect of β2GPI-induced aPL on pregnancy outcomes in an inbred strain of mice (PL/J). METHOD: Three groups of seven-week-old female PL/J mice (12 per group) were studied. Group A was immunized with β2GPI and group B with ovalbumin; group C was not immunized. After two booster injections, the mice were tested for aPL, anti-DNA by ELISA, and for ANA by indirect immunofluorescence. Platelet count and pregnancy outcomes were studied at the age of 14 weeks. RESULTS: The aPL and anti-DNA levels were higher at 12 and 14 weeks in group A; the optical densities (OD) were 1.72±0.6 and 0.699±0.25 for group A, 0.091 ±0.040 and 0.230±0.47 for group B, and 0.0435±0.003 and 0.119±0.026 for group C (comparing group A with groups B and C combined, P<0.001). ANA titers rose in groups A and B by age, but they were significantly higher at 14 weeks in group A. The mean titers were 1/286, 1/90, and 1/16 for A, B, and C, respectively (P<0.001). The platelet counts were not significantly different among the three groups. The litter size was significantly smaller in group A, as evidenced by the numbers of viable fetuses among the mice that became pregnant in each group: 0.75, 2.45, and 5.5 in groups A, B, and C, respectively. Seven pregnant mice in group A had complete resorption, seven pregnant mice in group B showed focal (partial) resorption areas, and only one mouse in group C had complete resorption of the embryos, as shown by histopathological studies, although the fecundity rate was similar in the three groups. CONCLUSION: Our data suggest a pathogenic role for β2GPI-induced aPL in the development of experimental models of APS in PL/J mice. 相似文献
997.
人重组C3片段通过IL-2自分泌效应对CTLL-2细胞产生促增殖作用 总被引:1,自引:0,他引:1
目的研究补体C3片段的体外生物学活性及其作用机理,进一步探讨C3片段与免疫细胞的关联。方法利用重组DNA技术表达纯化C3活性片段(命名为C33),观察其对IL-2依赖性的小鼠杀伤性T细胞株CTLL-2细胞的促增殖效应,并通过抗体封闭途径和分子杂交技术研究C33作用的机理。结果发现C33蛋白对CTLL-2细胞具有明显的促增殖作用,并呈剂量依赖关系;这一作用能够部分地被抗小鼠CD11b抗体所封闭,能够完全被抗小鼠IL-2抗体所封闭;分子杂交显示C33蛋白能够明显刺激CTLL-2细胞的IL-2mRNA表达。结论人重组C3片段C33可通过IL-2的自分泌效应对CTLL细胞产生促增殖作用,补体受体CR3参与这一作用。 相似文献
998.
H. Gron R. Pike J. Potempa J. Travis I. B. Thøgersen J. J. Enghild S. V. Pizzo' 《Journal of periodontal research》1997,32(1):61-68
Porphyromonas gingivalis is closely associated with the development of some forms of periodontitis. The major cysteine proteinases released by this bacterium hydrolyze peptide bonds only after arginyl (gingipain R) or lysyl residues (gingipain K). No target protein inhibitors have been identified for either enzyme, leading us to investigate their inhibition by human plasma α2 -macroglobulin (α2 M). Both 50- and 95 kDa gingipain R were efficiently inhibited by α2 M, whereas the catalytic activity of gingipain K could not be eliminated. All 3 enzymes were, however, inhibited by a homologous macroglobulin from rat plasma, α1 -inhibitor-3 a-Macroglobulins must be cleaved in the so-called "bait region" in order to inhibit proteinases by a mechanism involving physical entrapment of the enzyme. A comparison of the aminio acid sequences of the 2 macroglobulins indicates that the lack of lysyl residues within the bait region of α2 M protects Lys-specific proteinases from being trapped. On this basis, other highly specific proteinases might also not be inhibited by α2 M, possibly explaining the inability of the inhibitor to control proteolytic activity in some bacterially induced inflammatory states, despite its abundance (2-5 mg/ml) in vascular fluids. 相似文献
999.
Previous study has shown that α2D-adrenoceptors are involved in modulation of peristalsis in the rat ileum. The aim of the present study was to determine the
tissue location of α-adrenoceptors in the rat ileum by using a recently devised method. The pre-synaptic α-adrenoceptors were
characterised by measuring the potencies of agonists to inhibit transmurally-evoked (1 ms pulses, 10 Hz, 8-10 s trains) contractions
of the longitudinal and circular muscles and the affinities of antagonists. Post synaptic α-adrenoceptors were identified
by screening agonists and antagonists in carbachol-contracted tissues. In the circular muscle the order of potencies for inhibiting
transmurally-induced contraction was: clonidine ≥ oxymetazoline ≥ UK 14,304 ≥ guanfacine > talipexole > phenylephrine > azepexole.
The potency ratios relative to clonidine correlated to those previously derived using the rat ileum peristaltic reflex preparation.
Most of the α-adrenoceptor agonists, however, caused only small inhibitions of the longitudinal muscle contraction in response
to transmural stimulation, except phenylephrine and azepexole. RX 821002, yohimbine, rauwolscine, BRL 44408, phentolamine,
idazoxan, ARC 239, and prazosin inhibited the effect of clonidine on the circular muscle response with apparent pKB values best correlated with pKB or pKi values derived from the rat ileum peristaltic reflex preparation and other tissues known to have the α2D-subtype. The rank order of potencies at inhibiting carbachol-induced responses of both muscle layers was: phenylephrine ≥
oxymetazoline > clonidine ≥ talipexole > azepexole >> guanfacine. UK 14,304 was inactive up to 10 μM. The EC50 value of each agonist on the longitudinal muscle was not significantly different to the corresponding value on the circular
muscle. Prazosin was more potent than yohimbine at inhibiting the relaxant effect of phenylephrine in both muscle layers of
carbachol-contracted tissues. It is concluded that the recently identified α2D-adrenoceptors of the rat ileum are located on cholinergic neurons controlling circular muscle contraction. The study also
demonstrated the presence of postsynaptic α1-adrenoceptors involved in mediating relaxation in both muscle layers.
Received: 4 November 1996 / Accepted: 10 April 1997 相似文献
1000.
兴奋性氨基酸类神经毒剂与粉防己碱(tetrandrine,Tet)共同作用于原代培养胎鼠大脑皮层神经元24小时,发现107,106mol·L1Tet明显降低50μmol·L1谷氨酸(glutamate,Glu),300μmol·L1βNmethylaminoLalanine(BMAA,NMDA受体激动剂)和20μmol·L1βNoxalylaminoLalanine(BOAA,nonNMDA受体激动剂)导致的培养液乳酸脱氢酶(lactatedehydrogenase,LDH)活性的增高;细胞形态损害减轻,细胞数量增加。对20μmol·L1NMDA介导的神经元损伤改变无影响。提示Tet对某些Glu类神经毒剂引起的胎鼠大脑皮层神经元损伤有一定保护作用,其机制可能是抑制细胞膜上的Na+通道开放,阻止膜去极化而影响电压依赖性Ca2+通道启动。对NMDA受体可能亦有一定作用。 相似文献