荧光原位杂交技术分析人结肠菌群方法研究

建立荧光原位杂交技术分析人体内结肠菌群的方法。取受试者新鲜粪便 ,选用 5种特异性的 16SrRNA寡核苷酸探针 ,检测粪便样本收集后的保存时间、温度 ,离心条件及样本固定液存放时间对杂交计数结果的影响。结果建立最佳实验条件为 :粪便样本收集后应尽快在 4℃下保存 ,放置时间不要超过 12小时即作处理 ;样本的适宜离心条件为 70 0g 2分钟 ;样本用多聚甲醛固定后在 - 80℃下存放时间不要超过 5个月。该方法具有较好的稳定性 ,可以有效地检出个体之间结肠菌群的差异。     

US and UK versions of the EQ-5D preference weights: Does choice of preference weights make a difference?

Background Most US studies that estimate EQ-5D index score generally apply the UK preference weights. We compared the validity of a newly-developed US weights to the UK weights for use of EQ-5D as a measure of health-related quality of life. Methods Data were collected from a randomized clinical trial for patients with HIV (n = 1,126) in the US. Convergent validity was examined by comparing Pearson correlations of EQ-5D index scores with the MOS-HIV Health Survey scale scores and Physical and Mental Health Summary (PHS, MHS) scores using the US and UK weights. Known-groups validity of EQ-5D US versus UK index scores was compared using clinical variables (CD4+ cell count and HIV viral load), and the MOS-HIV PHS and MHS. Score changes in the EQ-5D index from baseline to week 50 were examined using effect size (ES) estimates. Results The mean EQ-5D index scores was slightly higher using US weights than UK weights (0.87 vs. 0.84, respectively). The correlation coefficient for EQ-5D utilities using the US and UK weights was 0.98. The correlations of EQ-5D index scores with the MOS-HIV scores were moderate and similar using the US and UK weights. The EQ-5D index scores discriminated equally well for both versions between levels of CD4+ count, HIV viral load, and PHS and MHS scores (P < 0.05), suggesting equivalent known-groups validity. The changes in EQ-5D index scores from baseline to week 50 were similar for both versions (ES: 0.21 vs. 0.22 for US and UK, respectively), suggesting equivalent responsiveness to score changes. Conclusions EQ-5D index scores generated using UK and US preference weights showed equivalent psychometric properties. For assessing treatment benefit in a single population, the use of either the UK or US weights as a measure of HRQOL will not change inferences. However, for comparisons across US and UK populations, the choice between these two weights should be based on their relevance to the study population.