首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 78 毫秒
1.
目的:脂肪细胞分化障碍是肥胖引发胰岛素抵抗的途径之一,观察中药姜黄提取物姜黄素对3T3-L1前脂肪细胞增殖分化的影响,在细胞水平分析姜黄素防治糖尿病可能的机制。方法:实验于2005-12/2006-03在哈尔滨医科大学营养与食品卫生学教研室完成。以3T3-L1前脂肪细胞为靶细胞,在常规培养时,分别加入0,5,10,15,20,25,30,35,40,50,80和100μmol/L浓度的姜黄素(购自美国Sigma公司),每个剂量设12个平行孔,培养3d,在此期间,分别在24,48,72h时,于姜黄素各剂量组中分别选取4个平行孔,以MTT法测定其增殖情况。在诱导分化时,设一组空白对照,实验组与诱导液同步加入0,2.5,5,10,15和20μmol/L的姜黄素,于诱导分化的第6天,采用油红O染色方法测定3T3-L1前脂肪细胞分化程度。结果:①姜黄素作用3T3-L1前脂肪细胞48h,5,10μmol/L剂量组的细胞吸光度值与空白对照相比显著增加(0.67±0.01,0.69±0.02,0.57±0.01,P<0.01),15μmol/L剂量组细胞吸光度值与空白对照相比差异无显著性意义(0.54±0.01,P>0.05),其余剂量组(20,25,30,35,40,50,80和100μmol/L)细胞吸光度值显著降低(0.53±0.01,0.47±0.01,0.42±0.03,0.45±0.03,0.18±0.01,0.2±0.01,0.16±0.04,0.44±0.05,P<0.01)。②姜黄素作用细胞48h时,促进或抑制细胞增殖的作用最强,40μmol/L以上浓度的姜黄素出现细胞毒性作用,大部分细胞成片脱落死亡。72h时,15~35μmol/L姜黄素组细胞的生长率有所增加,而40μmol/L以下姜黄素处理组细胞生长率仍维持在较低水平。③脂肪细胞油红O染色分光光度法结果显示2.5,5,10,15和20μmol/L姜黄素剂量组的细胞吸光度值与空白对照相比显著增加(0.38±0.05,0.49±0.04,0.56±0.06,0.75±0.06,0.77±0.1,0.83±0.06,0.38±0.05,P<0.05~0.01)。结论:不同浓度姜黄素对3T3-L1前脂肪细胞具有促进增殖和抑制增殖双重作用,低浓度姜黄素促进细胞增殖,高浓度姜黄素抑制细胞增殖。姜黄素通过促进3T3-L1前脂肪细胞的分化,从而增加脂肪细胞对胰岛素的敏感性,这可能是其防治糖尿病的机制之一。  相似文献   

2.
目的:观察中药提取物姜黄素联合肿瘤坏死因子相关凋亡诱导配体对肺癌细胞株A549生长抑制率和对细胞凋亡相关因子表达的影响,探索姜黄素改善肺癌A549细胞对肿瘤坏死因子相关凋亡诱导配体抵抗的机制。方法:实验于2003—10/2004-10在上海东方医院中心实验室完成。用购于中科院上海细胞所肺腺癌细胞株A549,将培养的A549细胞暴露于姜黄素、肿瘤坏死因子相关凋亡诱导配体及两者联合中,分4组,每组6孔,姜黄素组(40μmol/L姜黄素)、肿瘤坏死因子相关凋亡诱导配体组(25μg/L肿瘤坏死因子相关凋亡诱导配体)、联合组(40μmol/L姜黄素与25μg/L肿瘤坏死因子相关凋亡诱导配体联合)、对照组(RPMI1640细胞培养液)。①用四氮唑蓝法测定姜黄素组、肿瘤坏死因子相关凋亡诱导配体组以及联合组的吸光值,根据吸光度值计算肺癌细胞株A549细胞生长抑制率。②应用ApoAlert半胱氨酸天冬氨酸蛋白酶系列比色法凋亡相关蛋白半胱氨酸天冬氨酸蛋白酶3,半胱氨酸天冬氨酸蛋白酶8表达。③反转录聚合酶链反应测定凋亡调控蛋白bel-2/bax的表达。结果:①抑制率:肿瘤坏死因子相关凋亡诱导配体对肺腺癌A549细胞的抑制明显低于姜黄素,25μg/L肿瘤坏死因子相关凋亡诱导配体作用24h细胞抑制率仅有(2.65&;#177;1.416)%;两药联合对肺腺癌A549细胞的抑制作用明显增加[高达(30.97&;#177;1.318)%,P〈0.011。②凋亡相关因子:联合组半胱氨酸天冬氨酸蛋白酶3、半胱氨酸天冬氨酸蛋白酶8表达明显高于姜黄素组、肿瘤坏死因子相关凋亡诱导配体组、对照组[联合组:(50.77&;#177;0.812),(73.31&;#177;0.730)μmol/L;姜黄素组:(23.61&;#177;0.398),(26.84&;#177;1.511)μmol/L;肿瘤坏死因子相关凋亡诱导配体组:(9.63&;#177;1.024),(14.21&;#177;0.138)μmol/L;对照组:(3.69&;#177;0.486),(2.87&;#177;0.633)μmol/L,P〈0.011;联合组、姜黄素组的bel-2/bax明显高于肿瘤坏死因子相关凋亡诱导配体组(2.55&;#177;0.138,2.24&;#177;0.197,0.58&;#177;0.046,P〈0.01)。结论:肺癌A549细胞对肿瘤坏死因子相关凋亡诱导配体细胞耐受,姜黄素可能通过调整bcl-2/bax的表达,进而激活半胱氨酸天冬氨酸蛋白酶家族,增加肿瘤坏死因子相关凋亡诱导配体的敏感性。  相似文献   

3.
目的:观察低氧培养对大鼠肺动脉平滑肌细胞增殖的影响。以及Na^+/H^+交换抑制剂HMA对此增殖效应的抑制作用。 方法:实验于2004-12/2005-06在第四军医大学病理生理学教研室完成。健康SD大鼠2只,分离培养肺动脉平滑肌细胞,选择3-6代生长良好的细胞在常氧(O2的体积分数为0.21)或低氧(O2的体积分数为0.02)条件下培养,并分别给予0.3,1,3和10μmol/L等不同浓度的HMA(n=8),采用噻唑蓝比色实验和测定细胞总蛋白含量的方法观察细胞增殖情况,同时光镜观察细胞形态并测定培养液上清乳酸脱氢酶活力以反映药物的非特异性细胞毒作用。 结果:实验所用细胞样本均进入结果分析。①体积分数为0.02氧浓度较体积分数为0.05氧浓度下培养的大鼠肺动脉平滑肌细胞生长曲线抬高,低氧刺激24h增殖达到高峰。②体积分数为0.05血清培养使此增殖效应更为显著[噻唑蓝光吸收值无血清常氧组(0.238&;#177;0.011),无血清低氧组(0.280&;#177;0加9),体积分数为0.05血清常氧组(0.313&;#177;0.013),体积分数为0.05血清低氧组(0.389&;#177;0.011)]。③HMA可以抑制增殖,显著降低噻唑蓝吸光度值[对照组(0.391&;#177;0.011),0.3μmol/L组(0.377&;#177;0.010),1μmol/L组(0.328&;#177;0.012),3μmol/L组(0.289&;#177;0.006),10μmol/L组(0.246&;#177;0.007)]。④细胞总蛋白含量也显著降低[对照组、0.3μmol/L组、1μmol/L组、3μmol/L组、10μmol/L组分别为(193.30&;#177;8.51).(177.63&;#177;821),(166.84&;#177;9.48),(155.72&;#177;10.46)和(135.13&;#177;10.30)mnol/L]。⑤各浓度处理组细胞形态无改变,培养液上清乳酸脱氢酶活力也无明显变化[对照组、0.3μmol/L组、1μmol/L组、3μmol/L组、10μmol/L组分别为(212.23&;#177;8.44),(208.80&;#177;6.37),(209.79&;#177;7.12),(208.77&;#177;7.33),(215.42&;#177;7.81)U/L],细胞无明显损伤。 结论:0.3-10μmol/L浓度的Na^+/H^+交换抑制剂HMA可以有效抑制低氧刺激的大鼠肺动脉平滑肌增殖,此作用不是非特异的细胞毒作用所致。  相似文献   

4.
目的:分析蛋白酶体抑制剂lactacystin(乳胞素)与多巴胺能神经元变性死亡的关系,为帕金森病的治疗探索新的思路。方法:实验于2005-03/11在国家人类基因组北方研究中心完成。实验细胞人神经母细胞瘤细胞系SH—SY5Y由北京神经科学研究所提供。用50μmol/L6-羟基多巴胺处理的多巴胺能神经细胞系SH—SY5Y作为帕金森病的细胞模型,于对数生长期时接种到培养皿、6孔板、96孔板中,24h后分不同组给药处理:对照组,50μmol/L6-羟基多巴胺组;50μmol/L6-羟基多巴胺加0.1μmol/L lactacystin组、50μmol/L6-羟基多巴胺加0.25μmol/L lactacystin组、50μmol/L6-羟基多巴胺加0.5μmol/L lactacystin组。镜下细胞计数,计算细胞存活率=活细胞数/对照组活细胞数&;#215;100%。磺酰罗丹明B法测定细胞括力,在酶联免疫检测仪测定吸光度值,检测波长为540nm。吸光度值=实验组细胞孔吸光度值-空白孔细胞吸光度值。取8复孔读数均值。细胞活性=实验孔吸光度值/平行对照孔吸光度值&;#215;100%结果:①50μmol/L6-羟基多巴胺组对细胞有明显毒性,细胞存活率与对照组相比只有(51,31&;#177;3.52)%,加用0.1,0.25,0.5μmol/L lactacystin后,细胞存活率分别提高到(72.16&;#177;97)%,(82.36&;#177;3.78)%,(91.44&;#177;3.06)%,各组之间差异有统计学意义(P〈0.05)。而单用0.5μmol/L的lactacystln对细胞存活率无明显影响。②50μmol/L6-羟基多巴胺组对细胞有明显毒性可表现为细胞数量的减少,6-羟基多巴胺组细胞存活率只是对照组的(47.33&;#177;3.25)%,加用0.1,0.25,0.5μmol/L的lactacystin后,细胞存活率分别提高到(69.67&;#177;2.13)%,(80.38&;#177;1.12)%,(90.59&;#177;2.01)%,各组之间差异有统计学意义(P〈0.05)。而单用0.5μmol/L的lactacystin对细胞存活率无明显影响。③正常培养的神经元细胞密度大,轮廓清晰,突起明显,胞体折光性好,6-羟基多巴胺处理的神经元,多数细胞死亡,残存细胞突起缩短或消失,胞体皱缩,轮廓不清,胞体折光性差,6-羟基多巴胺加lactacystin处理的细胞细胞密度和形态介于前二者之间。结论:蛋白酶体抑制剂对多巴胺能神经元有保护作用,可能是通过阻断细胞凋亡,但确切机制有待于进一步的研究  相似文献   

5.
大豆苷元对原代培养大鼠成骨细胞功能的影响   总被引:2,自引:0,他引:2  
目的:了解大豆苷元对原代培养大鼠成骨细胞增殖、分化、钙含量及矿化功能的影响。 方法:实验于2004—08/2005—06在北京同仁医院检验科完成。选取出生24h以内的SD大鼠30只,断颈处死,无菌取头盖骨,获取成骨细胞进行培养。分为对照组、大豆苷元10μmol/L组、大豆苷元5μmol/L组和大豆苷元1μmol/L组。应用四甲基偶氮唑盐法、对硝基苯磷酸盐法、原子吸收分光光度法及茜素红染色方法观察大豆苷元对体外培养成骨细胞的增殖、碱性磷酸酶表达、基质钙含量及矿化结节形成的影响。 结果:①各浓度组与对照组相比均可增加吸光度值,刺激成骨细胞的增殖,其中大豆苷元10μmol/L组与对照组相比,差异有显著性意义(大豆苷元10μmol/L组为0.82130&;#177;0.10130,大豆苷元5μmol/L组为0.66370&;#177;0.04749,大豆苷元lμmol/L组为0.67750&;#177;0.05392,对照组为0.66250&;#177;0.07382。P〈0.005)。②各浓度组大豆苷元作用于成骨细胞48h,均可使碱性磷酸酶活性增加,差异有显著性意义(大豆苷元10μmol/L组为1.10917&;#177;0.34190,大豆苷元5μmol/L组为0.97433&;#177;0.33267.大豆苷元1μmol/L组为0.84033&;#177;0.20408,对照组为0.55050&;#177;0.15489,P〈0.005或0.02);各浓度组大豆苷元作用于成骨细胞72h,均可使碱性磷酸酶活性增加,差异有显著性意义(大豆苷元10μmol/L组为1.04667&;#177;0.12217,大豆苷元5μmol/L组为0.95000&;#177;0.07330,大豆苷元lμmol/L组为1.07700&;#177;0.14704.对照组为0.81867&;#177;0.07829,P〈0.005或0.02)。③各浓度组大豆苷元处理细胞18d,可增加细胞基质钙含量,其中大豆苷元5μmol/L组与对照组相比,差异有显著性意义[大豆苷元10μmol/L组(0.69975&;#177;0.13809)mg/L,大豆苷元5μmol/L组(1.01225&;#177;0.13277)mg/L,大豆苷元1μmol/L组(0.70375&;#177;0.07146)mg/L,对照组(0.60000&;#177;.10494)mg/L,P〈0.005]。④大豆苷元1μmol/L和5μmol/L组处理细胞18d,形成矿化结节数高于对照组[大豆苷元5μmol/L组(182.7&;#177;30.1)个,大豆苷元1μmol/L组(117.0&;#177;41.9)个,对照组(74.7&;#177;9.5)个,P〈0.0051。 结论:大豆苷元具有刺激成骨细胞增殖,提高碱性磷酸酶活性、细胞基质钙含量及矿化结节形成的数量的作用。  相似文献   

6.
背景:他汀类药物可以通过阻断甲羟戊酸的合成,抑制某些膜联结蛋白的翻译后修饰,从而阻断某些细胞内信号传导通路,抑制多种细胞的增殖。目的:探讨辛伐他汀对肺成纤维细胞的增殖、胶原合成及基质金属蛋白酶2分泌的影响。设计:完全随机设计,对照实验。单位:中国协和医科大学阜外心血管病医院器官移植研究室。材料:实验于2004—06/2004—10在中国协和医科大学北京协和医院心内科实验室完成。培养的新生SD大鼠的肺成纤维细胞,根据培养液中加入的干预药物浓度不同而分为辛伐他汀0,1,5,10,50μmol/L及辛伐他汀50μmol/L+甲羟戊酸200μmol/L组。方法:用消化法培养新生SD大鼠的肺成纤维细胞,给予不同浓度的辛伐他汀干预。四氮唑蓝比色法检测细胞增殖,细胞免疫组化法测定细胞胶原的合成,酶联免疫吸附法测定细胞培养上清液基质金属蛋白酶2的含量。主要观察指标:不同浓度辛伐他汀及辛伐他汀加甲羟戊酸干预后肺成纤维细胞增殖和胶原合成能力,以及基质金属蛋白酶2分泌量。结果:①辛伐他汀5,10,50μmol/L组四氮唑蓝比色A490值,肺成纤维细胞表达Ⅰ,Ⅲ型胶原的平均吸光度值(A值)及培养上清液中的基质金属蛋白酶2含量明显低于辛伐他汀0μmol/L组(0.520&;#177;0.010,0.334&;#177;0.011,0.260&;#177;0.012,0.111&;#177;0.011;0.508&;#177;0.011,0.324&;#177;0.014,0.232&;#177;0.015,0.083&;#177;0.015;0.445&;#177;0、017,0.305&;#177;0.015,0.216&;#177;0.015,0.068&;#177;0.012;0.561&;#177;0.013,0.361&;#177;0.012,0.289&;#177;0.012,0.140&;#177;0.013,t=3.359~8.111,P&;lt;0.05~0.01)。②辛伐他汀50μmol/L+甲羟戊酸200μmol/L组四氮唑蓝比色A490值,肺成纤维细胞表达Ⅰ,Ⅲ型胶原的平均吸光度值(A值)及培养上清液中的基质金属蛋白酶2含量明显高于辛伐他汀50μmol/L组(0.567&;#177;0.015,0.354&;#177;0.014.0.283&;#177;0.012,0.138&;#177;0.011,t=4.715—10.950,P&;lt;0.01)。结论:辛伐他汀能抑制肺成纤维细胞增殖和胶原合成,并可减少基质金属蛋白酶2的分泌,抑制肺成纤维细胞黏附迁移功能,并可通过影响甲羟戊酸通路而具有抗细胞增殖作用。  相似文献   

7.
目的:探讨复方水蛭合剂对局灶性脑缺血细胞因子免疫损伤的保护作用。方法:Wistar大鼠正常组6只,空白对照组12只,复方水蛭合剂组36只。检测大鼠大脑中动脉缺血后6,24h脑组织匀浆白细胞介素1、肿瘤坏死因子、一氧化氮的变化及复方水蛭合剂对其影响。结果:大鼠大脑中动脉缺血后6,24h模型组脑组织匀浆肿瘤坏死因子、白细胞介素1、一氧化氮[6h:(73.47&;#177;7.04)kIU/L(0.87&;#177;0.05)μg/L(89.07&;#177;6.69)μmol/L,24h:(90.75&;#177;7.63)kIU/L(0.98&;#177;0.07)μg/L(114.16&;#177;9.03)μmol/L]明显比正常组[(57.55&;#177;4.85)kIU/L(0.70&;#177;0.09)μg/L(51.43&;#177;5.49)μnol/L]高(P<0.01),大、中剂量复方水蛭合剂组明显比空白对照组低(P<0.05~0.01)。病理形态学检查:大、中剂量复方水蛭合剂组与空白对照组比较均较轻。结论:复方水蛭合剂对脑缺血所致的细胞因子的免疫损伤有保护作用。  相似文献   

8.
目的:观察盐酸氟桂利嗪对同型半胱氨酸诱导的人脐静脉内皮细胞株黏附分子表达的影响。 方法:实验于2005-02/08在西京医院神经内科实验室完成。人脐静脉内皮株细胞培养,取第4—7代指数生长期细胞,接种到96孔板,24h细胞贴壁后换液,加入药物处理,随机分为正常对照组、同型半胱氨酸组及盐酸氟桂利嗪组3组,正常对照组,仅予空白RPMI-1640培养基培养24h;同型半胱氨酸组,分别加入终浓度为100μmol/L、200μmol/L、500μmol/L.1000μmol/L的同型半胱氨酸培养24h;盐酸氟桂利嗪组:加入终浓度为10μmmol/L盐酸氟桂利嗪及终浓度分别为100μmol/L、200μmol/L、500μmol/L、1000μmol/L的同型半胱氨酸,培养24h。以上每组各种浓度共8孔。用ELISA法检测各组不同培养条件下可溶性细胞间黏附分子1和可溶性血管细胞黏附因子1的吸光度值(波长490nm)。 结果:同型半胱氨酸组中随着培养液同型半胱氨酸浓度的增加可溶性细胞间黏附分子1的吸光度值从(0.143&;#177;0.013)增至(0.175&;#177;0.006),与对照组相比差异有显著性意义(P〈0.01);可溶性血管黏附分子1从(0.112&;#177;0.008)增至(0.147&;#177;0.014).与对照组相比差异有显著性意义(P〈0.01);10μmmol/L的盐酸氟桂利嗪+100μmol/L同型半胱氨酸组与相同浓度的同型半胱氨酸组相比吸光度值也减少.差异无显著性意义(P〉0.05);10μmmol/L的盐酸氟桂利嗪+200μmol/L、500μmol/L、1000μmol/L同型半胱氨酸组的吸光度均低于相同浓度的同型半胱氨酸组.差异有显著性意义(P〈0.01);表明盐酸氟桂利嗪明显抑制同型半胱氨酸所诱导的可溶性细胞间黏附分子1和可溶性血管细胞黏附因子1的表达。 结论:盐酸氟桂利嗪能够减少同型半胱氨酸引起的人脐静脉内皮细胞株黏附分子的上调,可能对细胞具有保护作用。  相似文献   

9.
目的:以在某种程度上可反映成骨细胞增殖的成骨样细胞UMR106为靶细胞,考察蛇床子素对其细胞形态、增殖率和分化程度的影响。方法:实验于2003-03/2004—03,在中国人民武装警察部队医学院药物化学教研室药物活性筛选室进行。以大鼠成骨肉瘤细胞系UMR106为靶细胞,以雌二醇1&;#215;10^-8mol/L为阳性对照,同时设空白对照组,蛇床子素干预组分为1&;#215;10^-8mol/L,1&;#215;10^-7mol/L,1&;#215;10^-6mol/L3个浓度组。①调整细胞浓度为4&;#215;10^-7L^-1,接种于12孔培养板上。48h后,倒置显微镜下观察细胞形态变化。②调整细胞浓度为2&;#215;10^7L^-1,接种于96孔培养板,采用四唑盐法测定各孔的吸光度,计算平均增殖率。③调整细胞浓度为2&;#215;10^7L^-1,接种于24孔培养板,磷酸对硝基苯基质动力学法测定细胞内外碱性磷酸酶括性。上述实验每组均设8个复孔。结果:①培养基中加入蛇床子素培养48h后,与对照组相比UMR106细胞数量明显增多,核分裂期多见,1&;#215;10^-6mol/L,1&;#215;10^-7mol/L组可见细胞重叠生长,分泌基质堆积明显。②UMRl06细胞经蛇床子素处理48h后,相对于对照组,1&;#215;10^-6mol/L组增殖率为52%,1&;#215;10^-7mol/L组为37%,1&;#215;10^-8mol/L组为16%。3个给药组与对照组相比差异均有显著性(t=37.36,14.94,6.81,P〈0.01)。③UMR106细胞经蛇床子素1&;#215;10^-6mol/L和经雌二醇1&;#215;10^-8mol/L处理24h和48h后。细胞内碱性磷酸酶活性均显著高于对照组[(825.17&;#177;1234),(775.16&;#177;8.67),(715.14&;#177;14.17)μkat/g;(2415.48&;#177;15.84),(2355.47&;#177;5.67),(2285.49&;#177;7.67)μkat/g;t=16.56,10.22;20.89,34.90,P〈0.01]。④UMR106细胞在浓度为1&;#215;10^-6,1&;#215;10^-7mol/L的蛇床子素及雌二醇10^-8mol/L培养24h后,细胞外碱性磷酸酶活性显著高于对照组[(781.66&;#177;50),(733.15&;#177;15.34),(728.81&;#177;9.84),(652.80&;#177;11.34)μkat/g;t=22.56,11.9,14.32,P〈0.01]。结论:蛇床子素可剂量依赖地促进UMR106细胞的增殖,刺激UMR106细胞的碱性磷酸酶活性,提示其可能具有直接促进成骨细胞增殖、分化的作用。  相似文献   

10.
活血化瘀药对大鼠脑缺血再灌注血管源性脑水肿的影响   总被引:5,自引:0,他引:5  
目的:探讨预防性应用活血化瘀药对大鼠脑缺血—再灌注所致血管源性脑水肿的作用。方法:大鼠138只单纯随机分为:对照组;假手术组;低剂量短时干预组;高剂量短时干预组;低剂量长时干预组和高剂量长时干预组,采用线栓法制备大鼠大脑中动脉阻塞模型。测定大鼠神经功能缺损程度,检测脑水含量、血清及脑匀浆一氧化氮含量及光镜、电镜的病理改变。结果:药物干预组鼠神经功能缺损程度较对照组轻(P&;lt;0.01),药物干预组血清一氧化氮含量:假手术组(106.5&;#177;7.5)μmol/L,低剂量短时干预组(94.6&;#177;7.9)μmol/L,高剂量短时干预组(104.7&;#177;6.1)μmol/L,低剂量长时干预组(104.6&;#177;5.6)μmol/L,高剂量长时干预组(112.6&;#177;9.3)μmol/L较对照组(85.7&;#177;6.1)μmol/L高,差异有显著性意义(t=-7.673~-2.832.P&;lt;0.05),脑匀浆一氧化氮含量:假手术组(46.9&;#177;7.8)μmol/L,低剂量短时干预组(85.9&;#177;5.2)μmol/L,高剂量短时干预组(86.7&;#177;5.3)μmol/L,低剂量长时干预组(81.6&;#177;3.9)μmol/L,高剂量长时干预组(65.5&;#177;7.2)μmol/L较对照组(99.8&;#177;2.6)μmol/L低(t=7.011~20.361,P&;lt;0.01),病理损害较对照组轻。结论:活血化瘀药能减少缺血再灌注大鼠脑的一氧化氮产生,降低血管源性脑水肿的程度,减轻神经细胞损伤,具有抗缺血再灌注损伤作用。  相似文献   

11.
A marked deficiency of 3-hydroxy-3-methylglutaryl coenzyme A lyase activity is present in cultured skin fibroblasts from a baby with 3-hydroxy-3-methylglutaric aciduria.  相似文献   

12.
Concentrations of 3'-fluoro-3'-deoxythymidine (FDT) and 3'-deoxy-2',3'-didehydrothymidine (D4T) in plasma declined in a biexponential fashion. Total clearance of D4T (1.75 +/- 0.22 liters/h/kg; mean +/- standard deviation) was significantly greater than that of FDT (1.19 +/- 0.19 liters/h/kg) owing to greater renal and nonrenal clearances of the former. Steady-state volumes of distribution of FDT (1.20 +/- 0.12 liters/kg) and D4T (1.07 +/- 0.15 liters/kg) were similar.  相似文献   

13.
3'-Fluoro-3'-deoxythymidine and 3'-deoxy-2',3'-didehydrothymidine are nucleoside analogs which inhibit human and simian immunodeficiency virus in vitro. The pharmacokinetic properties of these compounds in rhesus monkeys after intravenous, oral, and subcutaneous administration of the drug were compared. Half-lives, total clearances, and steady-state volumes of distribution of the two drugs were determined. The half-lives for the drugs by the different routes were between 0.58 and 1.4 h. Oral bioavailability of 3'-deoxy-2',3'-didehydrothymidine was incomplete, with an average of 42% +/- 15% of the dose reaching the systemic circulation. Absorption of 3'-fluoro-3'-deoxythymidine after oral administration was variable, with bioavailability ranging from 21 to 95%. Bioavailability after subcutaneous administration ranged from 59 to 77% for 3'-deoxy-2',3'-didehydrothymidine and from 52 to 59% for 3'-fluoro-3'-deoxythymidine. The ratio of concentrations in cerebrospinal fluid and serum for the drugs was about 0.15 at 1 h after drug administration and was independent of the route of administration, suggesting that a nucleoside carrier-mediated process is involved in the transport of these compounds to the central nervous system. Because of the similar metabolism of nucleoside analogs in monkeys and humans, the potential glucuronide formation was assessed. Whereas the glucuronide of 3'-fluoro-3'-deoxythymidine was readily detected in urine, the amount of 3'-deoxy-2',3'-didehydrothymidine glucuronidated was small or not detectable in one-half of the urine samples. Pharmacokinetic parameters for the two drugs were similar to each other and analogous to those for 3'-azido-3'-deoxythymidine in monkeys, suggesting that the same dose and scheduling of the drug can be used for all three compounds in prophylactic and therapeutic efficacy drug studies in rhesus monkeys.  相似文献   

14.
3-Deazaguanine (ICN 4221), 3-deazaguanosine (ICN 4793), and 3-deazaguanylic acid (ICN 5412) represent a new class of synthetic guanine analogs having antiviral activity. In vitro, nine ribonucleic acid and seven deoxyribonucleic acid viruses were inhibited, including influenza, parainfluenza, rhino-, vesicular stomatitis, adeno-, herpes-, cytomegalo-, vaccinia, pseudorabies, and myxoma viruses. They were effective orally against influenza types A and B and parainfluenza type 1 (Sendai) virus infections in mice, with a therapeutic index of 16 against the latter two viruses. The course of herpes encephalitis was altered only when the drugs were applied directly into the brain. In addition, these drugs were effective inhibitors of Friend leukemia virus-induced splenomegaly in mice; treatment also produced extensions of life in these animals.  相似文献   

15.
1. 3-Methylcrotonylglycine was identified in urine from an infant with 3-hydroxy-3-methylglutaric aciduria. 2. The concentration of 3-methylcrotonylglycine in urine was approximately one sixth of that of the other metabolite of 3-methylcrotonyl-CoA, 3-hydroxyisovaleric acid. 3. The presence of both metabolites in the infant's urine indicates an inhibition of 3-methylcrotonyl-CoA carboxylase activity in tissues of the infant.  相似文献   

16.
目的 探讨亚急性甲状腺炎的病因、临床表现、诊断及治疗。方法 对33例患者的病史,临床表现,实验室资料及治疗进行总结分析。结果 患病的女性多见,占78.7%,病前无上怂病史记载:所有病例均有甲状腺肿大并触痛,彩超均有甲状腺肿大伴低回声,所有患者经口服泼尼松治疗效果好。结论 为减少漏诊、误诊,对咽痛伴发热病例,按上感治疗无效且持续时间较长应警惕本病。注意触诊甲状腺有无肿痛并进行必要的辅助检查。肾上腺糖皮质激素是治疗本病唯一确切有效药物。  相似文献   

17.
18.
Hybrid organic–inorganic lead halide perovskites have been investigated extensively within the last decades, for its great potential in efficient solar cells and as an ideal light source. Among the studies on stimulated emission (SE), the emission is either out-of-plane for polycrystalline films or in-plane with randomly aligned single microcrystals and nanowires. In this work, we revealed in-plane propagation of SE from bromine-based perovskite polycrystalline thin films (CH3NH3PbBr3, or MAPbBr3). The output from in-plane SE is an order higher than the out-of-plane emission. It is proposed that large crystalline flakes in the films lead to the in-plane lasing phenomena. The output coupling can be found at grain boundaries, intergrain gaps, and artificial structures. Simulative results support the experimental phenomenon that large crystalline grains are profitable for in-plane propagation and over 90% photons can be sufficiently outcoupled when the gap is larger than a micron. Considering the fabrication and handling convenience, we propose that the MAPbBr3 thin films can be easily integrated for in-plane applications as the light source for photonic chips etc.

MAPbBr3 perovskite thin film contains large crystal flakes, which support the in-plane stimulated emission and its propagation within these polycrystalline films. The emission scatters at the natural or artificial edge of the film.  相似文献   

19.
A new assay has been developed for 3-hydroxy-3-methylglutaryl-CoA lyase, the final enzyme in the leucine degradative pathway. The assay was performed by incubating lysates of fibroblasts with [glutaryl-3-14C](d,l)-3-hydroxy-3-methylglutaryl coenzyme A. The products were analysed by high performance liquid chromatography with continuous liquid scintillation counting. This provided simultaneous identification and quantification of one of the enzymatic products, [3-14C] acetoacetic acid. The mean 3-hydroxy-3-methylglutaryl-CoA lyase activity in fibroblasts from five controls was 732 ± 81 (SD) pmol/min · mg protein. Using this assay, we have studied skin fibroblasts cultured from a patient with 3-hydroxy-3-methylglutaric aciduria and found 3% of normal 3-hydroxy-3-methylglutaryl-CoA lyase activity. The activities in skin fibroblasts cultured from the parents were 46 and 53% of control activity which is consistent with heterozygocity. Kinetic studies of 3-hydroxy-3-methylglutaryl-CoA lyase in skin fibroblasts cultured from two normal subjects yielded Km values of 14.4 and 18.8 μmol/l for 3-hydroxy-3-methylglutaryl-CoA.  相似文献   

20.
Time response and light yield are two of the most important features of a scintillation detector, and are mostly determined by the luminescence properties of the scintillator. Here we have investigated the radioluminescence (RL) characteristics of a single-crystalline hybrid lead halide perovskite at both room temperature and low temperature. A dual-channel single photon correlation (DCSPC) system with a vacuum chamber is employed for the measurement. A rise time faster than 100 ps and several times enhancement of the crystal scintillation performances at low temperature have been observed. These behaviors demonstrated that bulk solution-grown single crystals of hybrid lead halide perovskites (MAPbCl3 and Br-doped MAPbBr0.08Cl2.92, where MA = CH3NH3) can serve as stable scintillating materials for pulsed gamma detectors. In addition, this work provides a pathway for perovskite application and also attracts attention to investigating low-temperature scintillators.

Time response and light yield are two of the most important features of a scintillation detector, and are mostly determined by the luminescence properties of the scintillator.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号