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。     

Acute hypercalcemia, pancreatic duct permeability, and pancreatitis in cats

We investigated the effects of hypercalcemia on pancreatic duct permeability and pancreatitis in cats. Acute hypercalcemia was maintained by an infusion of calcium gluconate; controls received saline solution. Chronic hypercalcemia was maintained by diet and by vitamin D and dihydrotachysterol injections. Portal venous blood was analyzed for large dextran molecules that had been perfused through the pancreatic duct. In a separate group of hypercalcemic animals, we perfused the duct with activated pancreatic enzymes to induce acute pancreatitis. After 24 hours of hypercalcemia, dextrans were detected in the portal venous blood of 6 of 11 hypercalcemic and none of the 6 control animals (p less than 0.05). After 12 hours of hypercalcemia, dextrans were detected in all 7 hypercalcemic and 1 of 7 control animals (p less than 0.001). The degree of pancreatic inflammation was greater in the 12-hour animals than in the controls (p less than 0.001). After 14 days of hypercalcemia, however, there were no differences in dextran permeability or pancreatitis in experimental or control animals. Our results indicate that acute hypercalcemia increases the permeability of the pancreatic duct to molecules the size of pancreatic enzymes. This could be important in the pathogenesis of acute pancreatitis associated with hypercalcemic states.