Effect of various stabilizing agents on Imperata cylindrica grass pollen allergen extract

BACKGROUND: Allergen extracts are unstable, heat labile or susceptible to proteases. Stability of allergen extracts is important for proper diagnosis and therapy of allergic disorders. OBJECTIVE: The present study was undertaken to determine the preservation and stabilization conditions of Imperata cylindrica (Ic) grass pollen extract. METHODS: The Ic extract was kept with 0.1 mepsilon-aminocaproic acid (EACA), 0.75 m sucrose, 5% glycerol, 0.03% human serum albumin (HSA) or 0.4% phenol for different time periods. The extracts were stored for 3, 6 and 12 months each at 4 degrees C, 4 degrees C with daily exposure to room temperature (RT) for 1 h, and RT. The quality of extracts was analysed by SDS-PAGE, Western blot, ELISA, ELISA inhibition and skin test. RESULTS: Extracts kept with EACA and sucrose retained most of the protein bands followed by glycerol as determined by SDS-PAGE and Western blot during all storage periods and conditions in comparison with standard extracts. The extracts kept with HSA, phenol and without preservative (WP) showed protein degradation below 33 kDa after 3 months storage at all conditions. However, a 67-kDa allergen was stable in these extracts. EACA extract required 75 to 120 ng of protein for 50% inhibition in IgE binding under different conditions, whereas standard extract required 70 ng for the same. ELISA also demonstrated high allergenic reactivity of EACA extract. ID test on allergy patients with EACA extract demonstrated same allergenic potency as that of standard extract. CONCLUSION: EACA is the best preservative/stabilizing agent of Ic pollen extract, followed by sucrose and glycerol. Ic extract kept with phenol, HSA and without preservative showed degradation within 3 months. EACA preserved extract is equally potent as that of standard extract up to 1 year's storage.     

转录信号传导子和激活子3信号传导通路调控选择性环氧化酶2抑制剂抗结肠癌的机制

目的探究转录信号传导子和激活子3(Stat3)信号传导通路与选择性环氧化酶2(COX-2)抑制剂抗结肠癌细胞株HT-29机制的关系,明确COX-2抑制剂抗结肠癌细胞内信号传导机制。方法将选择性COX-2抑制剂NS-398,作用于结肠癌细胞系HT-29,运用MTT法检测细胞增殖状态;流式细胞仪观察NS-398对细胞凋亡的影响,进一步用RT-PCR检测药物作用前后HT-29中COX-2mRNA的表达;ELISA法测定体系前列腺素E2(PGE2)水平;Westernblot检测药物作用前后Stat3通路相关蛋白JAK2、Stat3的磷酸化活性和cyclinD1、Bcl-2的表达。结果结肠癌细胞系HT-29中COX-2mRNA呈高表达,NS-398呈时间、剂量依赖性方式抑制HT-29细胞增殖,促进其凋亡。NS-398使HT-29细胞COX-2mRNA和PGE2表达水平显著下降。同时p-JAK2、p-Stat3、cyclinD1、Bcl-2表达水平随作用时间延长而下降。结论癌基因Stat3信号传导通路调控了NS-398抗结肠癌的细胞内信号传导机制,最终通过其下游靶基因cyclinD1、Bcl-2影响结肠癌细胞系HT-29的增殖与凋亡。     

EFFECTS OF A SYNTHESIZED PHOSPHODIESTERASE INHIBITOR, ZSY-27, ON PANCREATIC EXOCRINE SECRETION OF THE DOG

The effects of a synthesized phosphodiesterase inhibitor, ZSY-27, on the secretion of pancreatic juice were investigated in dog isolated and blood-perfused pancreas, and compared with those of secretin and dopamine. Intravenous administration of ZSY-27 (0.3-1 mg/kg) elicited increases in pancreatic secretion. Intra-arterial (i.a.) administration of ZSY-27 (0.1-1 mg) also elicited increased secretion. The secretory activity of ZSY-27 (1 mg) was approximately equal to that of 0.1 units of secretin and 2.5 micrograms of dopamine. The concentration of bicarbonate in the pancreatic juice induced by ZSY-27 i.a. was increased, but the protein concentration was not increased significantly. These effects are analogous to those of secretin and dopamine. ZSY-27-induced pancreatic secretion was not modified by pretreatment with phentolamine, propranolol, atropine, sulpiride and cimetidine. Secretin-induced secretion was significantly potentiated by infusion of ZSY-27 (25 micrograms/min) but dopamine-induced one was not. These results suggest that ZSY-27 increases pancreatic secretion acting directly on the ductular cells of the dog pancreas, at least in part, through the increase of intracellular cyclic AMP concentration by inhibiting phosphodiesterase activity.     

Disposition of a silicon-containing amide, an inhibitor of acyl-CoA: cholesterol acyltransferase, in dog and rat

The pharmacokinetics of 3-(decyldimethylsilyl)-N-[2-(4-methylphenyl)-1-phenylethyl]propanamide (DMPP), an inhibitor of acyl-CoA:cholesterol acyltransferase, have been studied in the dog and the rat using 14C and 3H dual-labelled drug. In both species, gastrointestinal absorption of DMPP was slow and incomplete, amounting to approximately 20 per cent of the oral dose given in corn oil. In the rat, use of PEG-400, Tween 80, ethanol, and aqueous CMC as vehicles resulted in similar or lower absorption than corn oil. Absorbed DMPP was rapidly and extensively distributed to body tissues. Data from the rat showed highest concentrations of radioactivity in the liver and spleen, while concentrations in the adrenals and lung also markedly exceeded circulating radioactivity levels. In both dog and rat. DMPP was completely metabolized prior to excretion. The routes of biotransformation involved hydrolysis of the amide bond, oxidation of the phenyl ring, and degradation of the decyldimethylsilyl propanoyl moiety. The metabolites of DMPP were excreted slowly, predominantly in the faeces. The elimination half-life of 14C was 105 h in the dog and 83 h in the rat, while that of 3H was approximately 32 h in both species.     

还原型谷胱甘肽对大鼠肝星状细胞TIMP—1表达的影响

目的 研究还原型谷胱甘肽对大鼠肝星状细胞（hepatic stellate,cells,HSC)中金属蛋白酶1组织抑制因子（TIMP－2）表达的影响。从分子和蛋白水平探讨还原型谷胱甘肽对大鼠肝纤维化的作用和可能机制。方法 采用50％CCl4制备大鼠肝纤维化模型，在造模过程中给予还原型谷胱甘肽进行干预。应用RT－PCR才Western Blot技术，在分子和蛋白水平检测体外分离大鼠HSC中的TIMP－1的表达情况。结果 还原型谷胱甘肽干预组与模型组和正常对照组相比，HSC中TIMP的表达降低（P＜0．05）。结论 还原型谷胱甘肽的干预可下调大鼠HSC中TIMP－1的表达，对实验性肝纤维化起到减轻作用。     

防止银器文物变色的唑系复合缓蚀剂Ⅰ. 缓蚀剂成膜处理工艺与防变色性能的评定

:通过按正交法设计的紫外光照曝露等加速大气腐蚀实验 ,研究了用于防止银变色的唑系复合缓蚀剂成膜处理的工艺 ,并评定其对模拟文物银试片的防变色性能。采用极化曲线和交流阻抗Nyquist图 ,讨论了防变色作用的电化学机理。实验结果表明 ,缓蚀剂 PMTA、MBI和 MBO具有较好的协同作用 ,银试片在 5 0°C、p H 3.0、组分 MBO∶ PMTA∶ MBI为 1∶ 1 .7∶ 3(摩尔比 )、复合缓蚀剂浓度为 0 .0 1 89mol/L的溶液中 4h成膜处理后 ,经 48h硫华气氛和 36h紫外光曝露腐蚀实验 ,无色斑出现 ,表明缓蚀膜明显地提高了银试片的抗变色能力     

纤溶酶原激活物抑制物-1基因4G/5G基因型分布频率与心肌梗死和脑梗死相关性初步分析

目的研究我国汉族人纤溶酶原激活物抑制物-1基因启动子区-675位4G/5G(单鸟嘌呤核苷酸插入/缺失)基因多态性与心肌梗死和脑梗死的等位基因特异性的相关性.方法以等位基因特异性聚合酶链反应(AS-PCR)扩增56例心肌梗死患者,54例脑梗死患者,83例无关健康对照个体的基因组DNA,鉴定PAl-1 4G/5G基因型及分布频率,常规方法检验研究个体的主要临床和生化指标.结果PAI-1基因启动子区4G/5G基因多态性在心肌梗死,脑梗死患者组中的分布频率与对照组明显不同.在心肌梗死组中,4G/4G基因型分布频率(71.40%)比对照组(30.12%)显著增加(P＜0.001),杂合型4G/5G基因型分布频率(25.00%)比对照组(62.65%)明显降低;而在脑梗死组中,4G/4G,4G/5G基因型分布频率(分别为20.37%,55.56%)均比对照组(分别为30.12%,62.65%)低,5G/5G基因型明显增加(24.07%vs7.32%,P＜0.001).而且心梗组中血浆PAI-1活性水平随着4G等位基因的减少而降低;脑梗死组中,血浆PAI-1活性水平随着5G等位基因的升高而增加.心肌梗死、脑梗死患者组中的血浆PAI-1活性水平,甘油三酯水平和血糖水平都比对照组明显升高(分别为P＜0.001,P＜0.05,P＜0.001).结论本研究表明,中国汉族人PAI-1基因启动子区4G/5G基因多态性可能和心肌梗死、脑梗死发生的危险性相关,4G/5G基因多态性可能是一种重要的遗传性血栓性疾病的危险因子.     

Distribution of calcium-activated neutral protease inhibitor in the central nervous system of the rat.

The ubiquitous existence of calcium-activated neutral protease (CANP, calpain), an enzyme whose activity is regulated by calcium ions and a specific endogenous CANP inhibitor (calpastatin), is well known. Although there has been much investigation concerning the distribution and role of CANP, investigations of the distribution of the CANP inhibitor using immunohistochemical techniques are rare. We made antiserum against a 40K fragment of cDNA corresponding to two C-terminal repeats of rat liver CANP inhibitor expressed in Escherichia coli. Using this antiserum, we examined the distribution of CANP inhibitor in the rat central nervous system by the ABC technique and compared it with the distribution of CANP. Neurons and glias were stained, with the cytosol stained diffusely and the cell membranes stained clearly and strongly. Axons and myelin were stained faintly, but nuclei and vessels were not stained. The distribution of CANP inhibitor was thus found to be similar to that of CANP.     

用于筛选天然产物中脲酶抑制剂的脲酶活性测试方法的建立

抑制幽门螺杆菌产生的脲酶具有治疗胃炎和消化性溃疡的作用。用酚红指示剂和Ｂｅｒｔｈｅｌｏｔ试剂在９６孔培养板上检测重组脲酶活性，其灵敏度指标酚红法每ｍｇ酶蛋白引起的每分钟吸光度变化。△Ａ为６．９，而Ｂｅｒｔｈｅｌｏｔ法每ｍｇ酶蛋白引起的每分钟吸光度比值变化△Ａ为３１３。结果表明用Ｂｅｒｔｈｅｌｏｔ试剂检测重组脲酶活性适宜在９６孔培养板上大规模筛选天然产物中的脲酶抑制剂。