BACKGROUND:The enamel matrix derivative has been used in the clinical treatment of severe periodontitis; however, the mechanism(s) by which enamel matrix derivative promotes periodontal regeneration is stil obscure. OBJECTIVE:To explore the effects of enamel matrix derivatives on the differentiation and proliferation of periodontal ligament stem cels. METHODS:Periodontal ligament stem cels were isolated and identified from human teeth. Cloning forming efficiency, surface antigen expression and pluripotency were detected and identified. Enamel matrix derivatives with different concentrations (20, 50, 100 mg/L) were used to culture periodontal ligament stem cels for 2 and 4 weeks. Colagen synthesis and mineralized nodule formation were detected using Trichrom staining and Von Kosa’s staining, respectively; real-time RT-PCR was employed to detect expressions of colagen type I, osteocalcin, and RUX2; MTT and cel growth rate assay were used to detect the proliferation of periodontal ligament stem cels. RESULTS AND CONCLUSION:Periodontal ligament stem cels were spindle-shaped and showed a higher colony forming efficiency than periodontal ligament cels. The expressions of surface antigens of periodontal ligament stem cels-CD105, CD29, CD45, CD44 were respectively 99.8%, 99.7%, 1.26%, 98.8%, indicating periodontal ligament stem cels have the multilineage differentiation potential. Enamel matrix derivatives improve the colagen synthesis and mineralization nodule formation of periodontal ligament stem cels in a time-dose dependent manner. They also can improve the expression of osteogensis-related genes colagen type I, osteocalcin, RUX2 and proliferation of periodontal ligament stem cels.

Different varieties of Terminalia chebula Retz. were identified by DNA finger prints, andat the same time, some problems encountered during the application of RAPD for the identification ofTCM were studied. The polymorphic features of DNA finger prints of different species were compared.Results of the study showed that they were differently related in heredity which can provide a basis for thedifferentiation of one species from the other. Means for the solution of problems arised during RAPD ap-plication were suggested. It was concluded that RAPD is an effective method to identify T. chebula from itsconfusable varieties.

Objective To evaluate the effects of transforming growth factor β1 (TGF-β1 )on migration, adhesion and proliferation of periodontal ligament stem cells (PDLSCs)and explore the mechanisms of PDLSCs-induced periodontal remodeling.Methods PDLSCs were isolated and identified from human teeth.The effect of TGF-β1 on migration of PDLSCs was evaluated using transwell migration assay.Cells attachment assay was used to test the effect of TGF-β1 on the adhesion of PDLSCs.In addition,the effect of TGF-β1 on the proliferation of PDLSCs was evaluated by MTT and cell growth rate assay.Results The results showed that TGF-β1 induced the migration of PDLSCs in a dose-dependent manner,improved the adhesion and proliferation of PDLSCs.So we propose that TGF-β1 may promote periodium remodeling by inducing PDLSCs migration,following adhesion and proliferation in these areas.Conclusion This study demonstrated for the first time that TGF-β1 increases the adhesion and migration of PDLSCs in vitro .The signal pathway is involved in the TGF-β1-induced migration of PDLSCs and the mechanical-chemical interaction during the orthodontic periodontal remodeling will be researched in our further studies.

Objective:To evaluate the effects of amelogenin(AML)on the migration,adhesion and proliferation of periodontal liga-ment stem cells(PDLSCs).Methods:PDLSCs were cultured with AML at 0.25,50 amd 100 μg/ml respectively.The migration, adhesion and proliferation of the cells were examined by wound healing migration assay,transwell migration assay,attachment assay, MTT assay and cell counting,respectively.Results:AML induced the migration of PDLSCs in a dose-dependent manner(P <0.05), increased the adhesion and proliferation of PDLSCs(P <0.05).Conclusion:AML may promote the migration,adhesion and prolifer-ation of PDLSCs.

ObjectiveTo analyze the obvious and hidden preoperative and intraoperative blood loss during treatment of the intertrochanter fracture with proximal femoral nail anti-rotation (PFNA) so as to provide necessary data support for clinical perioperative treatment.MethodsThe clinical data of 216 patients with intertrochanteric fractured treated with PFNA between December 2005 and September 2010 were analyzed retrospectively.An analysis was done on preoperative and postoperative blood routine, perioperative and postoperative blood loss and transfusion, perioperative obvious and hidden blood loss and perioperative and postoperative blood transfusion.ResultsThe average blood loss was 48.9ml during operation, with no blood transfusion.Obvious hemochrome decrease (＜9 g/L) was found in 42 patients at 2-4 days after operation and the patients received blood transfusion for mean 300 ml.The mean obvious blood loss was 62.3 ml, while the mean hidden blood loss was 385 ml in all the patients.There was no obvious difference between males and females.ConclusionThe intertrochanter fracture is mostly seen in the elder patients.Compared with the minimal invasive operation, PFNA has more hidden blood loss, as indicates that much attention should be paid to the vital signs of the patients after surgery for prevention of the complications.

Objective:To identify the characteristics and risk factors of the refractures after percuta-neous kyphoplasty ( PKP) and percutaneous vertebroplasty ( PVP) .Methods:A retrospective analysis of 148 patients who had undergone PKP or PVP between March 2006 and October 2013 inPeking University People’ s Hospital was conducted.In the study, 29 patients with 42 refractured vertebra and 119 patients without refracture were included.All the patients were observed for a time of (34.4 ±26.8) months. Clinical, imaging and procedure related factors ( gender, age, height, weight, body mass index, the level of the injured vertebra, the time interval between the procedure and the refracture, the level of the refractured vertebra, the bone cement volume injected, performed PKP or PVP,performed unilateral or bilateral, the percentage of anterior vertebral height restoration, the correction of the Cobb angle, cement diffusion, bone mineral density, presence or absence of diabetes mellitus, history of fractures of the whole body, anti-osteoporosis treatment, cement leakage) for each group were analyzed by Cox propor-tional hazards regression analysis.Results:Of all the patients,16 (55.17%, 16/29) had refractures in the adjacent vertebra, and 13 (44.83%, 13/29) had refractures in the nonadjacent vertebra.Refrac-tures within 3 months accounted for 31.03%(9/29) of all the refractures, and within 1 year accounted for 55.17%(16/29).Both older age (P=0.027, HR=1.051, 95%CI=1.006-1.098) and a his-tory of fractures of the whole body (P=0.012, HR=0.386, 95%CI=0.184-0.812) were statistical-ly significant as the independent risk factors for predicting refractures.Others were not associated with re-fractures ( P>0.05) .Conclusion:Older age and a history of fractures of the whole body are the inde-pendent risk factors of the refractures after PKP and PVP.The mechanism of the refractures after PKP and PVP is mainly the natural development of osteoporosis.

Objective To evaluate the treatment of radial head fracture of different type. Methods The clinical data of 80 radial head fracture cases from November, 1999 to December,2009 were collected and analyzed retrospectively. Among the 80 cases,12 cases received conservative treatment( all type Mason Ⅰ ) ;48 cases received open reduction internal fixation (ORIF) (4 case type Mason Ⅰ ,15 cases type Mason Ⅱ ,24 cases type Mason Ⅲ,5 cases type Mason Ⅳ ); 12 cases received removing radial head ( 4 cases type Mason Ⅲ and 8 cases type Ⅳ ).8 cases received artificial joint replacement ( 8 cases type Mason Ⅳ ). Results All cases were followed up for 1.0 -4. 1 years. According to the Mayo Elbow Performance Index, the excellent and good rate of treatment in nonoperative,ORIF,excision of the radial head as well as artificial joint replacement was 83.3 % (10/12) ,87.5 %(42/48) ,75.0% (9/12) and 100. 0% (8/8) ,respectively. Conclusions Conservative treatment can be selected for type Mason Ⅰ ;Open reduction and internal fixation can be selected for type Mason Ⅱ , type Mason Ⅲ and part of type Mason Ⅳ. The excision of radial head or mental prosthesis replacement is alternative for type Mason Ⅳ for those can not be treated with open reduction and internal fixation.

Objective:To investigate the characteristics and perioperative management of hemophilia patients with fracture.Methods:Retrospectively, we analyzed 8 patients with hemophilia combined with fracture, who were admittted to our department from 2005 to 2013.Six patients were with hemophilia A and two with hemophilia B;Based on the severity of hemophilia, 2 cases were light, 3 moderate and 3 severe;Based on the location of fracture, 4 cases were femoral neck fractures, 1 femoral intertrochanteric fracture, 1 bilateral distal femur fractures, 1 tibiofibula fracture, and 1 humerus intercondylar fracture. Blood coagulation factor replacement therapy was conducted preoperatively, intraoperatively and postoper-atively, All the patients underwent closed or open reduction and internal fixation or joint replacement. Also, we analyzed the perioperative complications and observed whether the fracture healed.Results:The average age was 33.5 years (14 to 47 years); In 6 cases, fractures occurred at femur, accounting for 75%of all the fractures; Femoral neck fracture was treated by closed reduction and hollow screws fixation;Femoral intertrochanteric fracture, distal femur fracture, and tibiofibula fracture were treated by open reduction and internal fixation with plate;Humerus intercondylar fracture was treated by elbow joint replacement.Intraoperative bleeding was from 50 to 600 mL, an average of 262 mL;Perioperatively, the average use of FⅧ/activated prothrombin complex concentrates ( APCC) was 358 U/kg (125 to 554 U/kg) .Postoperatively, poor wound healing was observed in 2 patients, and the condition improved after symptomatic treatment; In patients with internal fixation, all the fractures united, and the average hea ling time was 14 weeks.No complications such as fixation loosening or rupture occurred after internal fixation.Conclusion:Hemophilia combined with fracture mainly occurred in the young, and the site of fracture was given priority to femur.With perfect preoperative preparation, on the basis of the replace-ment therapy, hemophilia combined with fractures was safe for surgical treatment, and postoperative frac-tures healing wasgood.But the risk of poor wound healing was high.

Objective To treat radial head fractures with open reduction and internal fixation, removal of the radial head and artificial joint replacement based on different fracture types to discuss the outcome of these methods and summarize optimal strategy for treatment of radial head fractures. Meth-ods A retrospective study was done on data of 47 patients with 48 radial head fractures treated in our de-partment from November 1999 to May 2008. Among them, nine patients were treated conservatively (all type Mason Ⅰ fractures), 28 treated with open reduction and internal fixation (one patient with type Ma-son Ⅰ fracture, 14 with type Mason Ⅱ and 13 with type Mason Ⅲ), eight with removal of radial head (three patients with type Mason Ⅲ fractures and five with type Ⅳ) and three with artificial joint replace-ment (all type Mason Ⅳ fractures). Results All patients were followed up for average 2.8 years (1-4.4 years). Two patients treated with artificial joint replacement were followed up for six months and three months respectively. According to the Mayo Elbow Performance Index, the excellence rate was 8/9 in conservative treatment, 82% (23/28) in open reduction and internal fixation, 6/8 in removal of the radial head and 3/3 in artificial joint replacement respectively. Conclusions The radial head fracture should be given anatomical reduction for early functional exercise. Conservative treatment can be used for type Mason Ⅰ fractures, open reduction and internal fixation for type Mason Ⅱ , type Mason Ⅲ fractures and part of type Mason Ⅳ fractures. The removal of radial head or mental prosthesis replacement are al-ternative for parte of type Mason Ⅳ fractures that can not attain stable fixation through open reduction and internal fixation.