赛赓啶对 KBV200细胞多药抗性的逆转作用

研究赛赓啶对KB_V200细胞多药抗性的逆转作用及逆转机制。在KB_V200细胞,采用MTT法,测出赛赓啶对长春新碱、阿霉素和鬼臼乙叉甙耐药的逆转系数分别为5.5,2.0和1.9,而对5-氟尿嘧啶、美法仑的细胞毒性作用无明显影响,表明赛赓啶为多药抗性逆转剂。荧光分光光度法测定表明,赛赓啶可使KB_V200细胞内阿霉素蓄积量增加。流式细胞荧光测定显示赛赓啶可增加罗丹明123的蓄积并减慢其外排。免疫细胞化学及狭缝杂交表明赛赓啶不影响KB_V200细胞的P-糖蛋白染色深度和 mdr1 RNA 表达水平。以上结果提示赛赓啶的多药抗性逆转机制是抑制P-糖蛋白泵的功能。     

华蟾蜍毒素对离体豚鼠输精管的作用

华蟾蜍毒素(华蟾素)使离体豚鼠输精管产生剂量依赖性收缩反应,利血平化豚鼠输精管及冷藏输精管对华蟾素反应减弱。给酚妥拉明、维拉帕米后,输精管对华蟾素反应均受抑制,溴苄胺可使反应潜伏期缩短。结果提示华蟾素收缩输精管反应可能与其促进肾上腺素能神经末稍NA释放有关。     

Cell-volume-dependent vascular smooth muscle contraction: role of Na+, K+, 2Cl− cotransport, intracellular Cl− and L-type Ca2+ channels

This study elucidates the role of cell volume in contractions of endothelium-denuded vascular smooth muscle rings (VSMR) from the rat aorta. We observed that hyposmotic swelling as well as hyper- and isosmotic shrinkage led to VSMR contractions. Swelling-induced contractions were accompanied by activation of Ca²⁺ influx and were abolished by nifedipine and verapamil. In contrast, contractions of shrunken cells were insensitive to the presence of L-type channel inhibitors and occurred in the absence of Ca²⁺_o. Thirty minutes preincubation with bumetanide, a potent Na⁺,K⁺,Cl^– cotransport (NKCC) inhibitor, decreased Cl^–_i content, nifedipine-sensitive ⁴⁵Ca uptake and contractions triggered by modest depolarization ([K⁺]_o=36 mM). Elevation of [K⁺]_o to 66 mM completely abolished the effect of bumetanide on these parameters. Bumetanide almost completely abrogated phenylephrine-induced contraction, partially suppressed contractions triggered by hyperosmotic shrinkage, but potentiated contractions of isosmotically shrunken VSMR. Our results suggest that bumetanide suppresses contraction of modestly depolarized cells via NKCC inhibition and Cl^–_i-mediated membrane hyperpolarization, whereas augmented contraction of isosmotically shrunken VSMR by bumetanide is a consequence of suppression of NKCC-mediated regulatory volume increase. The mechanism of bumetanide inhibition of contraction of phenylephrine-treated and hyperosmotically shrunken VSMR should be examined further.     

椎管内肿瘤26例围手术期的护理

0　引言　手术切除椎管内肿瘤是唯一有效的治疗方法 .由于病变部位的特殊性 ,手术难度大、危险性大 ,术后易出现神经损伤、脊髓缺血、水肿 ,发生呼吸障碍、高热、消化道出血、四肢瘫痪或截瘫等严重并发症 .其护理工作也具有一定的复杂性和特殊性 .1　临床资料　我院 2 0 0 0 - 0 5 / 11收治椎管内肿瘤患者 2 6 (男19,女 7)例 ,年龄 9～ 6 1岁 .颈椎段 14例 ,胸椎段 6例 ,腰椎段 5例 ,骶管内 1例 . 7例为转移瘤 ,2例为原发性胶质瘤 ,其余均为良性肿瘤 .本组患者以颈段椎管内肿瘤居多 (5 4% ) .2　讨论　为使患者安全渡过围手术期 ,术前健康教…     

抗补体蛋白对大鼠局灶脑缺血损伤的作用

0　引言　近年来脑缺血损伤的早期炎症受到重视 .有学者观察到在人脑梗塞部位白细胞集聚 ,临床预后与梗塞部位的白细胞数量有关 ,白细胞多者预后差 [1 ] .还有文献描述了大鼠持续性脑缺血损伤中的多形核中性细胞反应的时间过程 ,收稿日期 :1999-0 3 -2 6;　修回日期 :1999-0 5 -13基金项目 :国家自然科学基金资助项目 ( 3 9170 3 15 ) ;全军医药卫生科研基金资助项目 ( 92 5 0 5 2 )作者简介 :刘　立 ( 195 8-) ,男 (汉族 ) ,江苏省无锡市人 .副教授 ,博士 .Tel.( 0 2 9) 3 3 74819缺血 30 min就可以观察到多形核中性细胞于缺血部位的微血…     

Expression and characterization of Gag protein of HIV-1（CN） in Pichia pastoris

To express the core protein of HIV-1 of Chinese prevalent strain （HIV-1 （CN）） in Pichia pastoris, the fulllength gag gene was inserted into the secretory expression vector pHILS1. Linearized recombinant plasmid pHILGAG by Sail was electrotransformed into the yeast strain GS115, and the yeast transformants were identified by PCR. To induce the interest protein to be expressed, the PCR positive transformants were inoculated in the medium of BMGY and BMMY, mRNA of the strain was detected by RT-PCR, and the expressed protein was analyzed by SDS-PAGE, Western blotting and thin layer scanning. mRNA （1.3 kb） was amplified by RT-PCR. SDS-PAGE and Western blotting analysis showed that the molecular mass of the expressed protein was 55 kD, which was similar to the expected value, and the expressed protein could react with McAb to HIV-1 p24. Thin layer scanning analysis demonstrated that the whole amount of the expressed protein was approximately 13 % of the soluble protein in the supernatant. The recombinant yeast had good genetic stability. The optimal expression conditions of the engineering yeast were as follows： BMMY medium, 80-90% of dissolved oxygen, 1% methanol, and 3-day-cultivation course. Gag proteins were expressed under the optimal expression condition and purified via gel filtration chromatography. The purity of the interest protein was up to 85 %. After the purified proteins were inoculated into BALB/c mice, the anti-HIV-1 antibodies in the immunized mice could be detected by Western blotting.     

DNA vaccination using bacillus Calmette-Guerin-DNA as an adjuvant to enhance immune response to three kinds of swine diseases

In order to enhance the immune efficacy of DNA vaccination, experiments were conducted to investigate the regulating effects of Bacillus Calmette-Guerin （BCG）-DNA as an adjuvant on immune responses of mice against foot-and-mouth disease （FMD）, Aujeszky＇s disease （AID） and classical swine fever （CSF）. BCG-DNA was purified from BCG by ion-exchange chromatography. Three DNA vaccines （pVSG, pVgD and pVE2） against the respective infection were constructed, and BCGDNA was coimmunized to mice by muscle injection. The results showed that titres of specific immunoglobulin （Ig）G to the vaccines mounted remarkably in the sera of the adjuvant covaccinated mice （P〈0.01）. Antibody isotype IgG2a and IgG1 also increased, respectively, in mice coimmunized with BCG-DNA compared with those of the control groups （P〈0.01）. Cellular immune cytokine interferon-gamma and cytotoxic T lymphocytes were detected in coimmunized BCG-DNA groups （P〈0. 05）. Whereas interleukin-4, humoral immune cytokine, was not significant （P〉 0. 05）. These results suggest that codelivery of BCG-DNA with DNA vaccines against FMD, AjD and CSF can enhance the induction of antigen-specific, especially, cell-mediated immunity.