A lipophilic free radical initiator, 2,2'-azobis (2,4-dimethylvaleronitrile) (AMVN) enhances caspase-dependent apoptosis induced by hyperthermia.

PURPOSE: A free radical initiator, 2,2'-azobis (2-amidinopropane) dehydrochloride (AAPH), was previously found to enhance apoptosis by hyperthermia. Here, but more lipophilic free radical initiator, 2,2'-azobis (2,4-dimethylvaleronitrile) (AMVN) was investigated for its effects as a possible heat sensitizer. MATERIALS AND METHODS: Human myelogenous monocytic leukaemia U937 cells were treated with hyperthermia combined with a various concentration of AMVN for investigating its ability to induce apoptosis and various parameters to identify the pathway. RESULTS: Combined treatment of hyperthermia and AMVN induced DNA fragmentation markedly, while hyperthermia or AMVN alone induced marginal DNA fragmentation. Fractions of cells showed low mitochondrial membrane potential and increased superoxide production after the combined treatment. Experiments using various caspase inhibitors and a fluorogenic monitor of caspase 3 activities indicated that caspase acts both up- and down-stream of mitochondria. CONCLUSIONS: AMVN is suggested to be a potential heat sensitizer effective at a lower concentration than AAPH. The possible mechanism is discussed.     

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.     

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。     

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。     

黏膜上皮细胞培养模型及其在给药系统评价中的应用

 目的 综述黏膜上皮细胞培养模型的建立、评价、实验方法及在给药系统中的应用,为此方面的研究工作提供参考。方法 查阅、总结近年来国内外有关文献。结果 黏膜上皮细胞培养模型可在体外有效地研究药物及制剂的摄取、代谢、排放、转运以及生物黏附等过程。结论 黏膜上皮细胞培养模型被广泛用于多种给药系统研究中。     

针刺取穴与骨折愈合疗效关系初探

目的:初步探讨针刺取穴与骨折愈合疗效的关系,为临床研究和应用提供参考,方法选用48只体重2.0～2.5 kg的雄性纯种大耳白家兔,手术造成新鲜桡骨骨折模型,用区组随机法分为局部和邻近取穴组(A组)、远道和辨证取穴组(B组)、局部和邻近取穴加远道和辨证取穴组(C组)、空白对照组(D组)共四组,术后第一天开始对治疗组分别做电针治疗,于术后7 d、14 d、28 d取材做血液生化学、生物力学、放射学、组织学的观测.比较各组间上述指标的差别.结果:血清碱性磷酸酶含量14 d时A组和C组明显高于B组和D组(P＜0.01),骨折标本抗弯强度在28 d时A组和C组明显高于B组和D组(P＜0.01),X线量化评分14 d和28d时A组和C组明显高于B组和D组(P＜0.05),在各个时段各个指标A组与C组、B组与D组比较均无显著差异(P>0.05).结论:局部和邻近取穴能明显促进骨折愈合,而且具有操作简便,易于推广等优点,远道和辨证取穴则效果不明显,与前者合用也没有明显增强前者的疗效.