Objective To explore the influence of hyperbaric oxygen therapy (HBOT) on the learning and memory ability using a rat model of vascular dementia (VD).Methods Sixty Sprague-Dawley rats were selected and divided into a normal group,a sham operation group,a VD group and an HBOT group,each of 15 rats using a random number table.The improved four-vessel method was used to establish a VD model in all except the rats in the normal group,but for the sham operation group,the vertebral artery was not subjected to firing and the arteria carotis communis was not clipped.The HBOT group was then given HBOT for 7 days.The Morris water maze test was used to evaluate their learning and memory ability of all 4 groups.Results Compared to the normal group,the mean escape latency of the sham operation group,the VD group and the HBOT group was significantly longer in each case (P＜0.05).Their platform quadrant crossing times were also significantly less,and their quadrant swimming distance as a proportion of their total swimming distance was significantly smaller (P＜0.05).Compared with the sham operation group,the mean escape latency of the VD and HBOT groups was significantly longer (P＜0.05),the times of crossing platform quadrant were less and their quadrant swimming distance was a smaller proportion of their total swimming distance.As compared with the VD group,the mean escape latency of the HBOT group was significantly shorter [(25.73±6.20) s],the average platform quadrant crossing times were significantly more [(9.51±2.25) times] and the platform quadrant swimming distance of the HBOT group was significantly longer [(494.72±208.26)],representing a significantly larger proportion of the total swimming distance [(28.71 ± 5.32) ％] (P＜0.05).Conclusion HBOT can effectively improve learning and memory in vascular dementia,at least in rats.

Objective To establish a rabbit model of facial skin lifting and to evaluate the skin lifting effects of absorbable soft tissue plastic belt, and to provide experimental basis for clinical application of this plastic belt.Methods 36 Japanese white rabbits were randomly divided into model control group (n=6) and plastic belt lifting group (n=30). The model control group received only facial skin resection surgery, while the plastic belt lifting group had facial skin resection and plastic belt implantation.The changes of rabbit general status, skin lifting effects, performance of plastic belt and pathological changes of subcutaneous tissue after implantation were determined during the 4 weeks after surgery. Results The rabbit skin wound was healed within 3-7 days after surgery without infection.Meanwhile, the plastic belts did not show shifting or rupture, and only whitening around the perforations was observed in the two groups.Compared with the model control group, the MA and MB distances in the plastic belt lifting group were significantly lower ( P<0.01 ) , while the biological tension of plastic belts in the facial skin lifting rabbit models was significantly increased with the extension of time after implantation (P<0.01), and the biological tension was 18.62 N at 4 weeks after transplantation. In addition, the tensile intensities of perforations and plate in the two groups were significantly reduced at 4 weeks postoperatively (P<0.01), the tensile intensity of perforations and plate in the two groups were maintained at 35.07 N and 53.31 N, respectively, and the perforations/plate tensile intensity ratio of the two groups remained unchanged during 4 weeks after transplantation ( P >0.05 ) .Moreover, the molecular weight ( Mw ) , peak molecular weight ( Mp ) , Z molecular weight (Mz) and viscosity were gradually decreased along with the time passing after implantation (P<0.01), and its dispersion Mz/Mw ratio was also gradually decreased from 2 weeks after implantation (P<0.01), and no obvious pathological changes were found after subcutaneous implantation of the plastic belts.Conclusions We have successfully established a facial skin lifting rabbit model, and the plastic belt can obviously lift the facial skin fascia system and keep intact more than 4 weeks in the body.Therefore, this plastic belt can be applied for anti-wrinkle facial soft tissue lifting against the skin damage caused by aging.