ATP-dependent para-aminohippurate transport by apical multidrug resistance protein MRP2

BACKGROUND: Para-aminohippurate (PAH), a widely used model substrate for organic anion transport in proximal tubule epithelia, was investigated as a substrate for the apical multidrug resistance protein MRP2 (symbol ABCC2). This ATP-dependent export pump for anionic conjugates and additional amphiphilic anions was cloned recently and localized to the apical membrane of proximal tubules in human and rat kidney. METHODS: Membrane vesicles from HEK-MRP2 cells containing recombinant human MRP2 and from control vector-transfected HEK-Co cells were incubated with various concentrations of [3H]PAH, and the net ATP-dependent transport into inside-out vesicles was determined. Comparative studies were performed with membrane vesicles containing recombinant human MRP1. RESULTS: Transport rates at 10 micromol/L PAH were 21.9 +/- 1.9 and 1.6 +/- 0.4 pmol x mg protein-1 x min-1 (means +/- SEM, N = 10) with membrane vesicles from HEK-MRP2 and HEK-Co cells, respectively. The Km value for PAH was 880 micromol/L. The high-affinity substrate leukotriene C4 and the inhibitor of MRP-mediated transport, MK571, inhibited MRP2-mediated transport of PAH (100 nmol/L) with IC50 values of 3.3 and 4.0 micromol/L, respectively. The nephrotoxic mycotoxin ochratoxin A inhibited MRP2-mediated PAH transport with an IC50 value of 58 micromol/L. Ochratoxin A was itself a substrate for MRP2. CONCLUSIONS: PAH is a good substrate for the ATP-dependent export pump MRP2. The localization and function of MRP2 indicate that this unidirectional transport protein contributes to the secretion of PAH and other amphiphilic anions into the lumen of kidney proximal tubules.     

胞嘧啶脱氨基酶／5—氟胞嘧啶系统对人胰腺癌细胞恶性增？…

目的 探讨大肠杆菌胞嘧啶脱氨基酶（ＣＤ）／５－氟胞嘧啶（５－ＦＣ）系统对人胰腺癌细胞的体内外生长抑制作用。方法 将含ＣＤ基因的重组逆转录病毒载体导入人胰腺癌细胞形成转化细胞系、对转化细胞进行体内外药物敏感实验,包括：（１）计算转化细胞在前体药物５－ＦＣ作用下的细胞生长抑制率和克隆形成抑制率;（２）ＭＴＴ法检测旁观者效应;（３）观察５－ＦＣ对转化细胞裸鼠移植瘤的抑制作用。结果 转化细胞在５－ＦＣ作用     

鼻咽分泌物中β2微球蛋白测定的临床意义

To study its clinical significance, beta 2-microglobulin (beta 2-MG) in nasopharyngeal secretion was examined using radioimmunoassasy methods in 73 patients with nasopharyngeal carcinoma (NPC), 30 with chronic nasopharyngitis and 30 normal control subjects. In 31 NPC patients, the examination was repeated before and after radiotherapy. The average concentrations of beta 2-MG were 4.87 +/- 2.51 mg/L in NPC group, 1.05 +/- 0.64 mg/L in chronic nasopharygitis group, and 0.85 +/- 0.32 mg/L in the control. The beta 2-MG concentration was higher in the NPC patients than in both chronic pharyngitis patients and normal subjects (P < 0.01). The concentration was lowered down in NPC patients after radiotherapy, and remained high when the treatment failed to control the condition. It seems that beta 2-MG level in nasopharyngeal secretion is closely related to the prognosis and recurrence of nasopharyngeal carcinoma.     

对41例儿童旋毛虫病的临床观察

为了解儿童旋毛虫病的临床特征，对１９９２～１９９５年就诊的４１例儿童旋毛虫病进行分析。结果表明，患儿来自河南６个地区，主要因食猪肉馅饺子、烤羊肉串或食涮猪肉而感染。冬季为本病的高发季节。患儿平均年龄为８．８岁，男女之比为２．７１。长期发热和嗜酸性粒细胞增多为本病的主要表现，仅少数患儿有肌痛、胃肠道症状和皮疹。眼睑水肿仅见于发病早期。血清学检查对诊断本病有重要意义。预防本病的关键措施是加强肉检和改变不良的饮食习惯。     

DETECTION OF HUMAN TELOMERASE ACTIVITY BY TELOMERASE TRAP-ELISA ASSAY

ＤＥＴＥＣＴＩＯＮＯＦＨＵＭＡＮＴＥＬＯＭＥＲＡＳＥＡＣＴＩＶＩＴＹＢＹＴＥＬＯＭＥＲＡＳＥＴＲＡＰ—ＥＬＩＳＡＡＳＳＡＹＷｅｉＬｉｘｉｎ卫立辛ＷｕＭｅｎｇｃｈａｏ吴孟超ＹａｎＺｈｅｎｌｉｎ阎振林ＳｈｅｎＦｅｎｇ沈锋ＸｉｅＴｉａｎｐｅｉ谢天培Ｑｉａ...     

促黄体生成激素释放激素激动剂对卵巢上皮性癌增殖影响

了解促黄体生成激素释放激素激动剂（丙氨瑞林）对人卵巢上皮性癌HO－8910细胞的作用。方法：用MTT比色法和计细胞分裂指数方法，检测与不同浓度丙氨瑞林（0．1－1000nmol／L）共同培养48小时后的人卵巢上皮性癌HO－8910细胞。结果：丙氨瑞林可抑制癌细胞的增殖，使核分裂指数明显降低，与对照比较P＜0．01，MTT比色结果显示抑制作用存在着量效关系，10nmol／L浓度的丙氨瑞林可明显抑制HO－8910细胞的增殖，与对照比较差异有显著性意义（P＜0．05）。结论：丙氨瑞林在体外可明显抑制HO－8910细胞的增殖。     

慢性鼻窦炎的定义及发病因素浅析

长期以来对于慢性鼻窦炎的定义一直缺乏统～认识，这阻碍了人们对其病因、病理生理学的深入研究。近年来，随着鼻科学及相关基础学科的发展，人们对慢性鼻窦炎的定义展开了广泛的讨论，同时认识到慢性易窦炎是多种因素相互影响、相互作用的结果，临床上针对这些环节进行综合治疗有助于提高疗效、减少复发。1慢性耳塞炎的定义定义慢性鼻窦炎的关键在于区分急性和慢性鼻窦炎。现代观点认为区别急性与慢性疾病应根据病理学表现而非严格的时间考虑[1]，故一些学者将慢性鼻窦炎定义为粘膜存在明显的、持续的、不可逆的损伤、通过保守治疗难以解决…     

超选择动脉栓塞治疗血管搏动性耳鸣（附2例报告）

采用数字减影血管造影技术超选择性动脉栓塞治愈２例血管搏动怀耳鸣，并就发病原因、机理、治疗措施、临床特征进行讨论。     

听力正常人畸变产物耳声发射的基本特性

利用动态分析仪ＩＬＰＯ－９２，对４８例听力正常人在４组不同原始刺激强度下进行畸变产物耳声发射检查，结果发现平均ＤＰＯＡＥｓ图呈双叶型轮廓：在１．５ｋＨｚ和５ｋＨｚ附近。     

超声法提取绞股蓝总皂甙的工艺研究

本实验证明，超声法可以提高绞股蓝总皂甙的提取率，最佳提取工艺为超声高频提取3次，每次80min，得率为1．226％。