BACKGROUND:Freeze-dried bone has strong immunogenicity due to insufficient removal of xenoantigen.Deproteinized bone and completely-decalcified bone have weak antigenicity,but the fomer has no osteoinductive property,and the latter has poor biomechanical property,so both of tem are limited in clinical application.OBJECTIVE:To observe the change of rabbit peripheral blood T lymphocyte subsets after transplantation of tissue engineered bone constituted by partially-decalcified freeze-dried bone scaffold and the histological changes of transplanted tissue.DESIGN,TIME AND SETTlNG:Randomized grouping,controlled animal observation.Performed in the State Key Laboratory of Biotherapy(I.E.Department of Stem cells and Tissue Engineering),Huaxi Hospital,Sichuan University between June 2006 and June 2007.MATERlALS:Tissue-engineered bone was in vitro constructed using osteoblasts.Which were derived from rabbit periosteum and used as seeding cells,and xenogeneic cancellous bone,which were antigen self-digested,partially-decalcified freeze-dried bone.METHODS:Forty-eight rabbits were randomly divided into the following 4 groups,with 12 rabbits in each group:partially-decalcified freeze-dried bone group(partially-decalcified bone group),tissue engineered bone group,autogenous bone group.And allogeneic bone group.Partially-decalcified freeze-dried bone,tissue engineered bone,autogenous bone,and allogeneic bone were respectively implanted into the 1 cm segmental defect in rabbit radius in above-mentioned groups.MAINOUTCOME MEASURES:Prior to and 1,2,and 4 weeks after implantation,the change of rabbit peripheraI blood T lymphocyte subsets were examined by flow cytometry；At 2,4,8,and 12 weeks after implantation,osteogenesis of the 4 materials was examined by routine histological examination.RESULTS:①In the partially-decalcifled bone group,peripheral blood CD4+and CD8+1r lymphocytes were significantly increased at 1 and 2weeks afterimplantationthan priortoimplantation(P<0.05).At 4 weeks after implantation.CD4+T lymphocytes were increased,but not significantly,compared with prior to implantation(P>0.05).In the autogenous bone group,CD4’and CD8+T lymphocytes were increased,but not significantly(P>0.05).In the allogeneic bone group,CD4’and CD8+T lymphocytes were significantly increased at weeks 1,2,and 4 after implantation than prior to implantation and the synchroale phase in the other groups(P<0.05).②inthetissue engineeredbonegroup,at week 2 after implantation,osteoblasts and chondroblasts were visible in the material porous,in addition,a new mixed tissue containing bone and cartilage formed and surrounded by osteoclasts,and partial rack was destroved and absorbed.At week 4,newly formed bone had turned into woven bone.At week 8.Lamellar bone was foand.And partially-decalcified freeze-dried bone was completely degraded and absorbed.At week 12,the implant had been completely substituted by lamellar bone,and medullary cavity was recanalized.CONCLUSION:Tissue-engineered bone constituted by taking partially-decalcified freeze-dried bone as scaflfold led to an increase in peripheral blood T lymphocytes,but which did not influence its good repair capabmtv of bone defects.

Objective:This study aims at exploring the groin area, the ulnar side of the wrist, and the medial plantar side as a more optimal donor area for repairing children’s hand volar skin defects.Methods:From December 2017 to December 2018, clinical data of children with palmar skin defects of hands who underwent full-thickness skin grafting in the Department of Burn and Plastic Surgery, Children’s Hospital Affiliated to Chongqing Medical University, were retrospectively analyzed. All skin grafts survived utterly. According to the donor site of full-thickness skin graft, the children were divided into three groups: the groin, ulnar wrist, and medial plantar skin donor group. The PANTONE skin tone guide measured the color difference between the full-thickness skin graft and the surrounding skin. The postoperative scars of the recipient and donor areas were scored by the Patient and Observer Scar Assessment Scale. Meanwhile, the postoperative effect and parents’ satisfaction with recipient and donor areas were evaluated. Kruskal Wallis rank-sum test and Mann Whitney U test were used for measurement data. Fisher’s exact test was used for counting data. A P-value <0.05 was considered significant. Results:A total of 68 children were enrolled, including 44 males and 24 females. The mean age was (3.19 ± 2.74) years (ranging from 6 months to 14 years). Among them, 37 children’s palmar skin defects were reconstructed by full-thickness skin grafts from the inguinal region, 19 from the ulnar side of the wrist, and 12 from the medial side of the plantar. The final follow-up time was from 7 months to 18 months, with an average of (14.07±2.94) months. There were significant differences among the three groups in the pigmentation of skin grafts and parents’ satisfaction ( P<0.01). The color difference of medial plantar skin donor group and ulnar wrist skin donor group was small, and the groin skin donor group had the most obvious color difference of skin graft. The satisfaction of parents in the medial plantar skin donor group was the best, followed by the ulnar wrist skin donor group, and the groin skin donor group had the worst satisfaction of parents. There was no significant difference in scar evaluation in recipient and donor areas among the three groups( P>0.05). Among the parents’ satisfaction ratings in the receiving area of the three groups, the medial plantar group had the highest proportion of excellent, followed by the ulnar wrist group and the groin group. There were significant differences among the three groups( P<0.01). Conclusions:The full-thickness skin graft harvested from the medial plantar and ulnar side of the wrist are better choices for small or medium-sized palmar skin defects in children than the inguinal area with superior aesthetics. The medial plantar area is recommended as a donor site for the palmer skin defects in hands, choosing the ulnar aspect of the wrist is more appropriate for the defects in the lateral fingers.

Objective:This study aims at exploring the groin area, the ulnar side of the wrist, and the medial plantar side as a more optimal donor area for repairing children’s hand volar skin defects.Methods:From December 2017 to December 2018, clinical data of children with palmar skin defects of hands who underwent full-thickness skin grafting in the Department of Burn and Plastic Surgery, Children’s Hospital Affiliated to Chongqing Medical University, were retrospectively analyzed. All skin grafts survived utterly. According to the donor site of full-thickness skin graft, the children were divided into three groups: the groin, ulnar wrist, and medial plantar skin donor group. The PANTONE skin tone guide measured the color difference between the full-thickness skin graft and the surrounding skin. The postoperative scars of the recipient and donor areas were scored by the Patient and Observer Scar Assessment Scale. Meanwhile, the postoperative effect and parents’ satisfaction with recipient and donor areas were evaluated. Kruskal Wallis rank-sum test and Mann Whitney U test were used for measurement data. Fisher’s exact test was used for counting data. A P-value <0.05 was considered significant. Results:A total of 68 children were enrolled, including 44 males and 24 females. The mean age was (3.19 ± 2.74) years (ranging from 6 months to 14 years). Among them, 37 children’s palmar skin defects were reconstructed by full-thickness skin grafts from the inguinal region, 19 from the ulnar side of the wrist, and 12 from the medial side of the plantar. The final follow-up time was from 7 months to 18 months, with an average of (14.07±2.94) months. There were significant differences among the three groups in the pigmentation of skin grafts and parents’ satisfaction ( P<0.01). The color difference of medial plantar skin donor group and ulnar wrist skin donor group was small, and the groin skin donor group had the most obvious color difference of skin graft. The satisfaction of parents in the medial plantar skin donor group was the best, followed by the ulnar wrist skin donor group, and the groin skin donor group had the worst satisfaction of parents. There was no significant difference in scar evaluation in recipient and donor areas among the three groups( P>0.05). Among the parents’ satisfaction ratings in the receiving area of the three groups, the medial plantar group had the highest proportion of excellent, followed by the ulnar wrist group and the groin group. There were significant differences among the three groups( P<0.01). Conclusions:The full-thickness skin graft harvested from the medial plantar and ulnar side of the wrist are better choices for small or medium-sized palmar skin defects in children than the inguinal area with superior aesthetics. The medial plantar area is recommended as a donor site for the palmer skin defects in hands, choosing the ulnar aspect of the wrist is more appropriate for the defects in the lateral fingers.