保存血小板的体外评估:是否有希望预见输入后血小板的生存和功能

输入病人体内的血小板的循环能力和功能与体外保存损害和受者的体内环境有关。患有血小板减少症的住院病人,体内影响血小板存活和功能的因素比体外保存损害的影响更重要。然而人们长久以来一直认为,预测血小板成分在体内的作用可以为现行的输血措施提供有价值的参考,也可能进一步提高临床疗效,同时更有效的管理血小板贮存。确实,新的病原菌灭活方法推动了临床应用,同时可能使浓缩血小板保存更安全、保存时间更长,精确评定临床有意义的浓缩血小板质量。 保存血小板在输血后的存活和功能差异较大。如果血小板处理小心,也没有长时间保存(采集后24—48小时内)便很快     

The association between leisure time physical activity and smoking in adolescence: An examination of potential mediating and moderating factors

Background: Although physical activity has been associated negatively with smoking in adolescence, the association is not well understood. Purpose: This study examines the relationship between adolescents’ leisure time physical activity and smoking behavior, while considering BMI, weight concern, sense of coherence, and physically active self-concept as potential mediating and moderating variables. Method: Data were obtained through a postal survey among 3,940 Danes aged 16 to 20. Bivariate and multivariate logistic regressions were performed to identify significant associations as well as mediating and moderating effects. Results: In the bivariate model, leisure time physical activity was negatively associated with smoking; adolescents who were active at least one hour per week were up to half as likely to smoke as inactive adolescents. In the adjusted model, however, the association disappeared. Further analyses revealed that physically active self-concept acted both as a mediator and as a moderator of the studied relationship. Conclusion: The data suggest that participation in leisure time physical activity is indeed inversely associated with adolescent smoking, but only when physical activity is perceived as an important part of the self. Hence, interventions designed to promote physical activity among youth may also aim to boost physically active self-concepts. This research was conducted with financial support from the Danish National Board of Health and the Danish Cancer Society.     

香烟提取物诱导牛冠状动脉内皮细胞损伤的机制

目的通过观察香烟提取物对牛冠状动脉内皮细胞(BCAEC)的损伤作用,为研究吸烟与心血管疾病之间的关系提供依据。方法以吸烟者体内通常的尼古丁浓度为基准,分别用尼古丁、香烟主流烟雾提取物(MSW)和侧流烟雾提取物(SSW)对 BCAEC 进行染毒(尼古丁染毒终浓度分别为1×10~(-5)、0.8×10~(-5)、0.9×10~(-5)mol/L),用显微数码成像系统记录细胞形态变化,检测凋亡细胞与坏死细胞的发生比例,测定 caspase 酶活力。结果经尼古丁、MSW 处理的 BCAEC 形态上发生凋亡样变化,处理24 h 后凋亡细胞发生率为5.89%和11.94%。而 SSW 处理后的 BCAEC 呈坏死样变化.处理24 h 后62.84%的细胞发生坏死。尼古丁和 MSW 可诱导 caspase-3活力增高。结论香烟提取物可诱导牛冠状动脉内皮细胞损伤,MSW 可引起细胞凋亡,SSW 导致细胞坏死,caspase-3的激活可能是香烟提取物诱导牛冠状动脉内皮细胞凋亡的机制。