Objective To investigate effects of physical exercise (PE) on object recognition memory in adult rats of postnatal isoflurane (Iso) exposures.Methods One hundred and ten postnatal 7-day SD rats (P7) were randomly divided into four groups: normal control group (Naive), Naive+PE group (received physical exercise in P21: a treadmill exercise 30min each day, 5 times/week, for 6 weeks), Iso group (three times of 2-hour Iso exposure in P7, P9, and P11), and Iso+PE group (received PE in P21 after postnatal Iso exposures). In P67, behavioral testing was conducted including open field and object recognition task (ORT), recording the time (Discrimination Ratios, DR) that rats spent on exploring each object, evaluating effects of PE on object recognition memory.Results There was no significant difference in influence of PE on open field testing in all of the groups (P>0.05). Compared with Naive, there was no group difference in DR (P>0.05) for all groups, but the DR of Iso male rats was significantly higher than that of Naive female rats in P67, with significant difference (P=0.034). Compared with non-PE groups, whether or not postnatal Iso exposures, the DR of PE male groups was significantly higher (compared with Naive and Iso group:P67,P=0.050,P=0.017; P95,P=0.037,P=0.019); in female rats, the DR for ISO+PE group was lower than that of Iso group in P67 (P=0.036), but the DR of Naive+PE group was higher than that of Naive group in P95 (P=0.004). Compared with male rats, the DR of non-PE female rats was significantly higher in P67 (vis. Naive and Iso group:P=0.022,P=0.011); but in P95, the DR of non-Iso female groups was significantly higher than that of male groups (vis. Naive and Naive+PE:P=0.008,P=0.017).Conclusions There is no obvious impact of postnatal Iso exposures on object recognition memory of adult rats. These Results also indicate that postnatal PE could improve object recognition memory of non-spatial learning in adult rats. In addition, exercise benefits have gender differences.

Objective To investigate effects of isoflurane anesthesia of different time interval on acute injury of brain function in neonatal rats with consistent total time of isoflurane anesthesia. Methods Seven-day neonatal Sprague-Dawley (SD) rats were randomly divided into normal control group (breathe the air), continuous anesthesia group (a single 6-hour exposure to 1.5% isoflurane), and intermittent anesthesia 1 day and 3 days groups (three times of 2-hour exposure to anesthesia with an interval of 1 day or 3 days), 12 rats in each group. The ratio of male to female was 5:7. They underwent the test of learning and memory in the radial arm maze (RAM) 21 days after birth, twice a day for 4 days. The number of entry into wrong arms, number of repeated errors, number of total arm entries, and time for completing the task were recorded for evaluation of effect of neonatal isoflurane on cognitive behavior in rats. Results ① Compared with normal control group, the percentage of number of errors > 3 in anesthesia of 3-day interval group was significantly decreased (33.3% vs. 46.9%, P < 0.05), the percentages of repeated errors > 0 and total arm entries > 8 were significantly increased (33.3% vs. 18.8%, 27.1% vs. 13.5%, both P < 0.05), but there were no statistically significant difference in the percentage of mistake number > 3 between continuous anesthesia group, interval anesthesia 1-day group and the normal control group (44.8%, 44.8% vs. 46.9%), the percentages of number of repeated mistake > 0 and total arm entries > 8 in above three groups were slightly increased as compared with those of normal control group (27.1%, 22.9% vs. 18.8%, 20.8%, 21.9% vs. 13.5%, all P > 0.05). No statistical differences in completing the task among normal control group, continuous anesthesia group, interval anesthesia 1 day and 3 days groups were found (minutes: 1.32±0.91, 1.54±1.05, 1.46±0.86, 1.38±0.79, all P > 0.05). ② It was found by gender analysis that the percentages number of repeated errors > 0 and total arm entries > 8 were significantly lower in female rats than those in the male rats only in normal control group (5.0% vs. 28.6%, P < 0.01; 5.0% vs. 19.6%, P < 0.05). There was no obvious gender difference in exposed groups. ③ Compared between groups of female rats, the percentages of repeated mistake > 0 in continuous anesthesia group, interval anesthesia 1 day and 3 days groups (25.0%, 25.0%, 30.0% vs. 5.0%, P < 0.05 or P < 0.01) and the percentage of total arm entries > 8 in interval anesthesia 1 day and 3 days groups were significantly higher than that of normal control group (22.5%, 25.0% vs. 5.0%, both P < 0.05). No significant difference about the RAM task in male rats of all the four groups was found. Conclusions Different time interval of neonatal isoflurane exposure may develop certain degree of acute brain injury in rats, characterized by cognitive function. Prolongation of the interval time significantly enhanced long-term memory in rats. Multiple neonatal exposures to isoflurane were associated with greater cognitive impairment than a single exposure. In addition, isoflurane can significantly increase cognitional functional disorder in the female, not in the male rats.

Objective To introduce treatment of old scaphoid fractures by internal fixation with common screws which have been modified into compression-like ones.Methods Twenty-five patients with old scaphoid fracture were admitted to our department from January,1995 to December,2002.They were 17 cases of delayed union,and eight cases of non-union and pseudoarticulation formation.All the patients were treated with open re- duction anti internal fixation by modified common cortical bone screws,some threads of which bad been erased so that they could act somewhat like compression ones.The modified screws were driven into the reduced scaphoid by simple surgical instruments to fix and compress the fracture ends.Results Nineteen cases were followed up for one to six years (mean,3 years).Fourteen cases of fracture healed,with an average healing time of 7 months.The mean extension-flexion arc of the injured wrists was between 106 degrees and 128 degrees.Three cases failed to heal,and two cases experienced deformed and sunken proximal scaphoid.Conclusions Common cortical bone screws can be easily changed into compression-like ones to treat old scaphoid fractures and result in satisfactory,clinic outcome.In addition,they are easily available,can be inserted through joint facet with limited negative effect on the joint,and play a double role of compression and fixation.