The changing clinical pattern of Reye's syndrome 1982-1990

OBJECTIVE: To describe trends in the clinical pattern of Reye's syndrome in the British Isles between 1982 and 1990; and to determine the relation between any changes and the June 1986 warnings against the use of aspirin in children. DESIGN: Development, and application to reported cases, of a scoring system designed such that patients showing the typical clinical and pathological features of 'classical' Reye's syndrome scored highly. The relations between 'Reye scores' and a number of explanatory variables were explored using multivariable analysis. SETTING: British Isles. SUBJECTS: 445 cases fulfilling the Reye's syndrome case definition reported to the surveillance scheme between January 1982 and December 1990. MAIN OUTCOME MEASURE: Individual 'Reye score'. RESULTS: Cases with high scores were more likely to have occurred in the 4 1/2 year period before June 1986 compared with the subsequent period (p < 0.006). Numbers of cases in the low and intermediate score categories declined by about 50% after June 1986, whereas those in the high category fell by 79%. High scorers were more likely to have received aspirin (p < 0.0001) and were older than intermediate and low scorers (p < 0.008). No relation was identified between score and season of onset. CONCLUSIONS: The decline in Reye's syndrome after the aspirin warnings cannot be explained entirely, as has been proposed, by improved diagnosis of 'Reye-like' inherited metabolic and other disorders: this would not account for the greater decline of the high scoring subgroup which also contained those cases most likely to resemble 'classical' Reye's syndrome and to have received aspirin. This study provides further evidence for the role of aspirin in a subset of cases meeting the standard diagnostic criteria for Reye's syndrome and supports the need to consider this disorder as a heterogeneous group of conditions including Reye-like inherited metabolic disorders.     

换液频率对骨髓间充质干细胞生物学特性的影响

目的:培养条件是影响骨髓间充质干细胞生物学特性的重要因素。实验考察换液频率对兔骨髓间充质干细胞增殖分化及代谢特性等的影响。方法:实验于2005-03/2005-06在华东理工大学生物反应器工程国家重点实验室完成。①实验材料:1月龄新西兰大白兔购自上海市淞江车墩实验动物良种场。实验过程中对动物处置符合动物伦理学标准。②实验方法:采用密度梯度离心法从兔股骨骨髓中分离得到骨髓间充质干细胞,体外培养扩增后,取生长良好的第3代细胞分别以24,48,72h时间间隔进行换液培养。③实验评估:观察细胞形态学变化,测定细胞生长曲线同时进行乳酸和氨代谢分析,并对几种条件下收获的细胞进行集落形成和成骨分化检测。结果:①每24h换液的细胞最早进入对数生长期,第5天达到增殖顶点,最大细胞数目可达3.44×105,分别是48h和72h换液频率的1.43倍和1.71倍。②每48h换液条件下收获的细胞具有最强的集落形成能力,明显高于每24h和每72h换液条件下收获的细胞。③3种换液频率条件下收获的细胞经成骨诱导后茜素红染色均为阳性,其中每48h换液的细胞胞外钙基质分泌最高。④3种换液频率条件下细胞的代谢曲线无明显差异,乳酸和氨均维持较低浓度,分别在5mmol/L和2mmol/L以下。结论:①换液频率对骨髓间充质干细胞的影响具有双向性。提高换液频率促进骨髓间充质干细胞的增殖,同时也加速了干细胞特性的丢失,导致集落形成能力和成骨分化能力下降。②普遍采用的三四天换液不能提供适合骨髓间充质干细胞生长同时利于干细胞特性维持的营养环境,提示可通过常规培养条件的优化使其有利于骨髓间充质干细胞执行对称的细胞分裂。