Objective To study the effects of formaldehyde inhalation on spatial learning abilities and hippocampal neurotransmitters levels of mice, and to explore the neurotoxic mechanism. Methods Three groups of male Kunming mice were exposed to different concentrations (0, 1.34 and 4.02 mg/m3) of gaseity formaldehyde, 4 h/day, for 7 consecutive days,and their behavior when they learned to perform a water labyrinth task and hippocampal neurotransmitters levels were tested. Results There was no significant difference was seen in swimming duration among groups. While on days 5 and 7, mice in group of 4.02 mg/m3 formaldehyde exposure made notable more swimming errors (P

Objective This study aimed to investigate the incidence and the cause for duodenalbiliary reflux and reflux cholangitis after metallic stent placement in distal common bile duct Methods After percutaneous transhepatic bile duct puncture and biliary outside drainage was performed, 16 cases with malignant distal biliary stricture underwent metallic stent placement in distal common bile duct Before stent placement, the routine laboratory studies including leukocyte, neutrophil percentage and the levels of total bilirubin and direct bilirubin in blood were performed for all patients. Two to five days [ an average of (3.3 ±0. 9) days ] after stent implantation, the above indexes were tested again, and 1 ml of water containing 185 MBq of 99Tcm-DTPA was given orally before extubation, then 99Tcm radioactivity in the bile was detected 2 hours later. For the measurement data obtained from the experiment, t test or Wilcoxon signed rank test was adopted to compare them, and P ＜ 0. 05 was considered to be statistically different Results In 14 cases, radioactivity was successfully detected in the bile 2-5 days after stent implantation. Twelve of them was detected to have radioactivity in the bile 2 hours before extubation with duodenal-biliary reflux. The technetium count in the bile accounted for 1.82% of the total intake dose. There was no radioactivity in the bile in 2 cases. In 14 patients, there were no symptoms of cholangitis such as high fever, chills, increased jaundice, and so on after stent implantation. The mean of white blood cell count was (7.59 t2. 62) × 109/L, and the median of neutrophil percentage was 0. 74. Compared with those before stent implantation, the difference did not reach statistical significance ( t = 0. 423, Z = 1. 036, P ＞ 0. 05 ).After stent implantation, the median of total bilirubin and direct bilirubin were significantly lower, which were 92. 2 and 74. 3 μmol/L. Compared with those before stenting,the difference was statistically significant (Z= -3. 170, -3. 170, P ＜0.05). Conclusions There is a high incidence of duodenal-biliary reflux after stent implantation in distal common bile duct in the early stage. However, there is no simultaneous cholangitis caused by duodenal-biliary reflux.