Donor's site evaluation after restoration with autografts or synthetic plugs in rabbits

AIM: To investigate donor site's area histological and immunohistochemical knee cartilage appearances after resurfacing iatrogenic defects with biosynthetic plugs orautografts. METHODS: Thirty New Zealand White rabbits were used in this study. A full-thickness cylindrical defect of 4.5 mm(diameter) × 7 mm(depth) was created with a hand drill in the femoral groove of every animal. In Group A(n = 10) the defect of the donor site was re-paired with a biosynthetic osteochondral plug, in Group B(n = 10) with an osteochondral autograft, while in Group C(control group of 10) rabbits were left untreated. RESULTS: Twenty-four weeks postoperatively, smooth articular cartilage was found macroscopically in some trocleas' surfaces; in all others, an articular surface with discontinuities was observed. Twenty-eight out of 30 animals were found with predominantly viable chondrocytes leaving the remaining two-which were found only in the control group- with partially viable chondrocytes. However, histology revealed many statistical differences between the groups as far as the International Cartilage Repair Society(ICRS) categories are concerned. Immunofluoresence also revealed the presence of collagen Ⅱ in all specimens of Group B, whereas in Group A collagen Ⅱ was found in less specimens. In Group C collagen Ⅱwas not found. CONCLUSION: The matrix, cell distribution, subchondral bone and cartilage mineralization ICRS categories showed statistically differences between the three groups. Group A was second, while group B received the best scores; the control group got the worst ICRS scores in these categories. So, the donor site area, when repairing osteochondral lesions with autografting systems, is better amended with osteochondral autograft rather than bone graft substitute implant.

Preliminary Research on a Mesenchymal Stem Cell-model for Screening Traditional Chinese Medicines

The authors focused their attention on the establishment of a mesenchymal stem cell（MSC） model for screening traditional Chinese medicines（TCMs） so as to investigate the effects of Shuanglong Formula（SLF） components（Ginsenosides and salvianolic acids） and ingredients（ginsenoside Rb1 and salvianolic acid B） on cardiomyocyte differentiation from MSCs.The SLF components were analyzed and quantified by HPLC-TOF-MS.Cardiomyocyte differentiation was induced by culturing MSCs in the induction medium supplemented with SLF ingredients,SLF components,5-azacytidine（5-aza）,5-aza＋SLF ingredients and 5-aza＋SLF components,respectively,for up to 30 d,and evulated by the expression of Cardiac-specific myosin heavy chain（MHC） and troponin I（TnI） via immunofluoresent staining.Slow growth rate and changed morphology were observed during cardiomyocyte differentiation.After 20 d of induction,differentiating MSCs were positive for MHC and TnI staining.The effects of SLF components were better than those of SLF ingredients.Taken together,SLF can induce the differentiation of MSCs into cardiomyogenic cells in vitro,and MSCs can be used as a powerful tool for screening TCMs.