焙烧处理HZSM—5对正己烷芳构化及结焦的影响

研究了焙烧温度对ＨＺＳＭ－５分子筛表面性质,正己烷芳构化反应及结焦性能的影响。发现ＨＺＳＭ－５于６５０℃焙烧３ｈ后,在３０ｈ的芳构化反应中,催化剂有良好的活性及抗结焦性能。     

Therapeutic effects of undercorrection by LASIK following RK and PRK for correction of high myopia

WiththeextensivedeveIopmentofradialkerato--tomy(RK)and(photorefractivekeratectomy(PRK),thepostopcrativeundercorrectioncausedbyvarioustypesofcauses,especiallyinthecasesofSD(sphericaldiopter)>--6.0D,hasbecomeaknottyprobleminclinicalpractice.TreatmentofRKorPRKagainwouldprobablyencounterinundercorrec-tion.Moreover,theoperationwascomplicatedandcomplicationsoccurfrequently,especiallyforthosepatientshavingepisodeofhormone--inducedglaucomapreviously.Inourcenter,wecorrectedwlthLASlKandachievedsa…     

Clinical and biochemical characteristics of growth hormone-secreting pituitary tumors

It has been confirmed that gsp oncogene is oneof the main cause of growth- hormone secreting pitu-itary tumor in native acromegaly patients[1] ,but dif-ference in clinical and biochemical characteristics be-tween gsp- positive and gsp- negative patients re-mained unknown. We selected 1 8cases of growthhormone( GH) - secreting pituitary tumors to studytheir clinical and biochemical characteristics.All pa-tients also underwent pituitary function combinativestimulating testto evaluate the pituita…     

Preliminary study on the relationship between cAMP level and gsp expression in cultured human pituitary somatotrophinomas

Growth hormone ( GH) releasing hormone( GHRH) is one of the main hypothalamic hormonewhich regulates the GH secretion depending on theadenylyl cyclase- c AMP- protein kinase A intracellularsignal transduction pathway[1] .GH- releasing peptide( His- D- Trp- Ala- D- Phe- Lys- NH2 ,GHRP- 6) is asynthetic hexapeptide able to strongly stimulate GHsecretion via protein kinase C transduction system[2 ] .Therefore,to gain further insight into the mecha-nisms of action of synthetical GHRP-…     

The role of protein kinase C and its effect on GHRH in the regulation of hormone secretion by somatotrophinomas

In recent years, the most exciting advance inthe research of human pitllitary tumors is the discovery that 30 %--40 % of hfuman pituitary somatotrophinomas carry somatic missense single--basemutations within codons 201 and 227 of the genefor the a--subunit of the stimulatory GTP--bindingprotein, Gs (Gsa). These mutations, termed gsponcogenes, result in constitutive activity of adenylyl cyclase and the subsequent elevations in intracellular cAMP levels are thought to be responsiblefor tumor g…     

大鼠慢性萎缩性胃炎癌前病变气虚血瘀证动物模型的研制

目的 探讨慢性萎缩性胃炎（ＣＡＧ）癌前病变气虚血瘀证动物模型的研制方法。方法 ２５只大鼠随机分为２组,正常对照组不予造模,造模组采用甲硝基亚硝基胍（ＭＮＮＧ）溶液自由饮用,雷尼替西灌胃,饮饱失常的综合法造模２０周,观察２组大鼠周身状况,血液红细胞免疫功能、ＬＰＯ、ＳＯＤ、ＧＳＨ－Ｐｘ、ＴＸＢ２、６－ｋｅｔｏ－ＰＧＦ１α、ＴＸＢ２／６－ｋｅｔｏ－ＰＧＦ１α及胃粘膜病理等变化。结果 模型组大鼠周身状     

OBSCAN-Ⅱ眼前节诊断系统检测正常成人眼角膜最薄点

用OBSCAN-Ⅱ眼前节诊断系统对50例（100眼）正常成人角膜进行全角膜厚度检测,重点观测角膜最薄点的厚度位置。结果表明,角膜最薄点厚度的平均值为(554.33±34.46)μm,与角膜中心点厚度相关系数为0.976,但最大相差值可达23μm,角膜最薄点位置在角膜中心点(0.58±0.26)mm半径范围内,以颞下方为多。结果提示OBSCAN-Ⅱ眼前节诊断系统对角膜最薄点的检测更为精确。     

2158 例神经管缺陷儿的产前B型超声波诊断分析

回顾性分析1990～1993年全国28省、市、自治区233所医院,住院分娩的孕满28周的2158例神经管缺陷儿的产前诊断情况,了解我国神经管缺陷儿产前B型超声波诊断情况.结果显示:我国神经管缺陷产前诊断的比例为61.8%,产前B型超声波诊断的比例为56.5%,其中无脑畸形、脑膜脑膨出、脊髓外翻的产前B型超声波诊断比例分别为66.7% 、62.5%、52.5%.胸段(46.4%)、腰段(43.4%)的脊柱裂产前B型超声波诊断的病例较颈段 (35.5%)、骶段(31.7%)高(P<0.05).省级、市级、县级及部队工矿医院神经管缺陷的产前B型超声波诊断比例分别为55.7%、59.4%、49.0%、57.2%.1991～1993年神经管缺陷产前B型超声波诊断比例分别为53.5%、55.8%、60.7%、54.7%.无脑畸形、脑膜脑膨出、脊髓外翻产前B型超声波诊断的比例较高.     

雌激素和异黄酮类药物对内皮细胞粘附分子CD54表达的影响

为探讨雌激素和异黄酮类药物对内皮细胞粘附分子CD54表达的影响,作者采用10ng/ml肿瘤坏死因子(TNFα)处理人脐静脉内皮细胞6小时,并加用不同浓度的异黄酮(WZ1,WZ2)和雌激素(WZ3,WZ4)进行干预48小时,而后用流式细胞仪定量测定细胞表面粘附分子CD54的表达,并进行统计学分析.结果:①10ng/ml的TNFα可使内皮细胞表面粘附分子CD54的表达升高4倍,与对照组相比具有统计学差异(P＜0.05);②10-10mol/L、10-8mol/L、10-6mol/L异黄酮和异卟黄酮对由TNFα诱导的内皮细胞的CD54表达有轻度促进作用;③哌嗪雌酚酮和雌二醇预处理内皮细胞48小时后再加TNFα激活,内皮细胞表面CD54平均荧光强度与单纯TNFα组相比下降明显(P＜0.05),各浓度组之间不具统计学差异(P＞0.05).以上结果提示:异黄酮和异卟黄酮对内皮细胞粘附分子CD54的表达无抑制作用;哌嗪雌酚酮和雌二醇可在一定程度上抑制CD54的表达,从而为抗粘附疗法提供了一条新思路.     

金属卟啉作为双功能模拟酶的研究

根据超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性结构相似原理,作者首次提出金属卟啉化合物可作为SOD和CAT双功能模拟酶,并对合成的4 种金属卟啉[四-(对磺酸基苯基)卟啉铁、四-(对磺酸基苯基)卟啉铜、四-(对磺酸基苯基)卟啉锰、四-(对磺酸基苯基)卟啉钴]进行了仿SOD和CAT的部分生物学功能检测 .结果显示:核黄素-蛋氨酸光明法证实它们在10-5～10-6mol/L浓度范围内有清除O(*2)-的作用;分光光度法证实它们能催化H2O2 的分解,且分解率随浓度增大而增大;用小鼠肝匀浆法测定4种金属卟啉、SOD和CAT,均表明有良好抗脂质过氧化作用;大鼠心脏缺血再灌注实验表明四-(对-磺酸基苯基)卟啉锰能降低活性氧对心肌的损伤程度, 对再灌注损伤心肌有保护作用.