Informed consent, parental awareness, and reasons for participating in a randomised controlled study

BACKGROUND: The informed consent procedure plays a central role in randomised controlled trials but has only been explored in a few studies on children. AIM: To assess the quality of the informed consent process in a paediatric setting. METHODS: A questionnaire was sent to parents who volunteered their child (230 children) for a randomised, double blind, placebo controlled trial of ibuprofen syrup to prevent recurrent febrile seizures. RESULTS: 181 (79%) parents responded. On average, 73% of parents were aware of the major study characteristics. A few had difficulty understanding the information provided. Major factors in parents granting approval were the contribution to clinical science (51%) and benefit to the child (32%). Sociodemographic status did not influence initial participation but west European origin of the father was associated with willingness to participate in future trials. 89% of participants felt positive about the informed consent procedure; however, 25% stated that they felt obliged to participate. Although their reasons for granting approval and their evaluation of the informed consent procedure did not differ, relatively more were hesitant about participating in future. Parents appreciated the investigator being on call 24 hours a day (38%) and the extra medical care and information provided (37%) as advantages of participation. Disadvantages were mainly the time consuming aspects and the work involved (23%). CONCLUSIONS: Parents' understanding of trial characteristics might be improved by designing less difficult informed consent forms and by the investigator giving extra attention and information to non-west European parents. Adequate measures should be taken to avoid parents feeling obliged to participate, rather than giving true informed consent.     

分子生物学技术在植入前诊断中的应用

植入前诊断是产前诊断非常早的一种方法，目的是放弃携带严重遗传病的胚胎，将健康胚胎植入母体。两种主要的方法是聚合酶链反应（PCR）和荧光原位杂交（FISH）。PCR用于单基因病诊断，FISH用于染色体异常诊断。临床主要应用于存在遗传风险的患者如携带单基因病和染色体易位的患者。随着分子生物学技术的飞速发展，如比较基因组（CGH），全基因组扩增技术（WGA），引物延伸预扩增（PEP），间期核转换技术及DNA芯片技术（DNAchip）等PGD先进检测手段的应用，单细胞用于诊断单基因或多基因突变及染色体疾病，为期不远。     

急性白血病病人GST-π、MRP1表达及其相关性的临床研究

目的：检测急性白血病（acute leukemia，AL）病人谷胱甘肽硫转移酶-π（glutathione—S—transferltse-π，GST-π）、多药耐药相关蛋白1（multi—drug resistance relevant protein 1，MRP1）的表达，探讨二者与AL多药耐药（multi—drug resistance，MDR）的关系及临床意义，明确二者在AL中的表达有无相关性以及两者表达与AL病人临床特征的关系。方法：采用免疫组织化学S—P法检测80例AL病人及30例正常人外周血单个核细胞GST-π、MPP1表达。运用SPSS10．0统计软件，采用X^2检验、四格表精确概率法、t检验、直线相关分析方法统计结果。结果：GST-π、MRP1在难治组的阳性率均高于初治组和完全缓解组；在初治组的阳性率均高于对照组。GST-π、MRP1在AL难治组中的表达具有高度相关性。GST-π、MRP1表达阳性组完全缓解率低于阴性组。GST-π、MRP1的表达与AL难治组病人年龄、性别、骨髓幼稚细胞比例及外周血白细胞计数无关。且两者在急性淋巴细胞白血病（acute lymphoblastic leukemia，ALL）组、急性非淋巴细胞白血病（acute nonlymphoblastic leukemia，ANLL）组表达无差别。结论：GST-π和MRP1的高表达与AL临床耐药有关；GST-π和MRP1在难治组中的表达密切相关；GST-π和MRP1表达阳性的AL病人的完全缓解率明显降低，两者可能是影响AL疗效的重要指标；GST-π和MRP1在难治组表达阳性率与年龄、性别、外周血白细胞计数、骨髓幼稚细胞比例可能无关，且在ALL组与ANLL组中差别无统计学意义。     

氟伐他汀对心衰大鼠基质金属蛋白酶、转化生长因子及左室重构的影响

目的:了解基质金属蛋白酶-2(MMP-2)及转化生长因子-β1(TGF-β1)在心肌梗死大鼠左室重构及心衰发展过程中的改变,以及氟伐他汀的干预作用,探讨心梗后心衰的发生机制。方法:选用雄性SD大鼠67只随机分为假手术组、心梗组和心梗他汀组,经冠状动脉前降支结扎术建立心肌梗死后心衰模型,手术24 h后心梗他汀组大鼠管饲氟伐他汀4 mg·kg-1·d-1,假手术组和心梗组大鼠管饲安慰剂。术后3 d、4周、8周检测大鼠非梗死区心肌MMP-2的含量(Western-blot法)、胶原、TGF-β1的改变(免疫组化法),压力传感器记录左室血流动力学改变。结果:术后各时点非梗死区心肌的MMP-2含量,心梗组及心梗他汀组显著高于假手术组(P<0.05),而心梗他汀组显著低于心梗组(P<0.05);术后各组各时点非梗死区心肌TGF-β1表达的变化趋势与MMP-2相同;与心梗组比较,心梗他汀组术后4周和8周的心功能明显改善,胶原容积分数(CVF)及Ⅰ／Ⅲ型胶原比值(Ratio of type Ⅰ／Ⅲ)降低(P<0.05)。结论:氟伐他汀通过减少非梗死区心肌MMP-2和TGF-β1的含量,而减轻心梗后非梗死区心肌胶原网络的破坏及反应性胶原的过度沉积,从而预防和逆转心室重构,改善心脏功能。     

蟾蜍毒素联合紫杉醇抑制人胃癌MGC803细胞增殖和诱导凋亡的作用

目的探讨蟾蜍毒素联合紫杉醇抑制人胃癌MGC803细胞增殖及诱导凋亡的作用。方法应用MTT法检测不同浓度蟾蜍毒素及紫杉醇单药及联合对胃癌细胞MGC803增殖抑制作用;流式细胞术分析细胞凋亡和周期阻滞;Westernblot法检测C-FLIPL、Caspase-8蛋白的表达。结果(1)蟾蜍毒素及紫杉醇单药均抑制MGC803细胞增殖,呈剂量-时间依赖效应,且联合用药的细胞增殖抑制率明显高于单药组,差异有统计学意义(P<0.05)。24、48及72 h联合指数(CI)分别为0.77、0.86、0.72;(2) 40 nmol/L蟾蜍毒素、25 ng/ml紫杉醇单药及联合作用细胞24 h,流式细胞仪检测凋亡率分别为14.13%、19.74%及53.30%,联合组与单药组比较差异有统计学意义(P<0.05);(3)Western blot结果显示,蟾蜍毒素、紫杉醇单药组及联合组作用细胞24 h后,C-FLIPL蛋白表达依次下降至对照组的78.38%、64.71%、46.73%,Caspase-8蛋白表达上调至对照组的150.25%,156.86%,180.58%。结论蟾蜍毒素协同紫杉醇诱导胃癌MGC803细胞凋亡,且可能与下调C-FLIP、上调Caspase-8蛋白有关。