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。     

Repeated unilateral epidural blockade

Unilateral epidural analgesia occurring in a parturient three times in successive pregnancies is reported. Possible causes are reviewed, and clinical and radiological evidence in support of the most likely explanation are presented.     

N-acetyl-L-aspartate and other amino acid metabolites in Alzheimer's disease brain: a preliminary proton nuclear magnetic resonance study.

We used proton nuclear magnetic resonance spectroscopy in this preliminary study of perchloric acid extracts of 12 Alzheimer's disease (AD) and five control brain samples to measure the relative levels of taurine, aspartate, glutamine, glutamate, gamma-aminobutyric acid (GABA), and the putative neuronal marker, N-acetyl-L-aspartate (NAA). We found no significant changes in taurine, aspartate, or glutamine. NAA was lower in AD compared with control, and this decrease correlated with the number of senile plaques and neurofibrillary tangles in adjacent tissue sections. GABA levels also were lower in AD brain. Glutamate levels were greater in AD than control and showed a close, inverse correlation with NAA levels. These findings suggest that the decrease in NAA reflects neuronal loss and that remaining neurons could be exposed to a relative excess of glutamate and a relative lack of GABA. If present in the neurotransmitter pool, this imbalance could result in neurotoxic cell damage. This hypothesis is further supported by in vitro and in vivo phosphorus 31 nuclear magnetic resonance findings.