Knee osteoarthritis(KOA)is a common chronic degenerative bone and joint disease characterized by degeneration and wear of knee cartilage.It is commonly found in middle-aged and elderly people and seriously impacts on their lower limb activity and quality of life.At present,the treatment of early and middle stage KOA mainly relies on the conservative methods such as oral medication,joint injection,topical patches and traditional Chinese medicine.Platelet rich plasma(PRP),as an autologous platelet concentrate,is rich in various growth factors and has no risk of immune rejection.In recent years,it has been widely used in the repair of bone,joint,and soft tissue injuries.However,the short biological half-life of growth factors in PRP and the fluidity of injection sites can result in insufficient binding force,short action time,poor target therapy efficacy,and the need for repeated injections in the joint cavity,which will increase the risk of iatrogenic infections.Hydrogels are cross-linked polymer networks containing water,and their high histocompatibility and drug release have attracted much attention.The slow and continuous release of drug is achieved by loading PRP onto hydrogel.Its unique adhesion reduces the flow of drug in the joint,thus extending the local action time of PRP and reducing the need for repeated injection.This article reviews the biological characteristics of PRP and hydrogel,the mechanism of action and clinical application of PRP loaded hydrogel in the treatment of KOA,and analyzes the existing problems and challenges,aiming to provide more effective treatment options for KOA patients through the in-depth discussion of this new treatment method.

Previous studies have shown that PTPRZ1 has a regulatory effect on PI3K/AKT signaling pathway and has the potential to be-come a new protein regulating fibroblasts.Oral mucosal fibroblasts were randomly divided into control group,ANE group,ANE+ov-PT-PRZ1 group and ANE+ov-NC group.Cell viability and apoptosis,expression of PTPRZ1,PI3K and AKT were detected.Mice with oral submucosal fibrosis were established and the expressions of PI3K and AKT were detected.The overexpression of PTPRZ1 can regulate the apoptosis and activity of oral mucosal fibroblasts induced by ANE in a dose-dependent manner,and PTPRZ1 can regulate oral mucosal fi-broblasts by activating the PI3K/AKT signaling pathway of oral mucosal fibroblasts,promoting fibrosis and aggravating the disease.

Previous studies have shown that PTPRZ1 has a regulatory effect on PI3K/AKT signaling pathway and has the potential to be-come a new protein regulating fibroblasts.Oral mucosal fibroblasts were randomly divided into control group,ANE group,ANE+ov-PT-PRZ1 group and ANE+ov-NC group.Cell viability and apoptosis,expression of PTPRZ1,PI3K and AKT were detected.Mice with oral submucosal fibrosis were established and the expressions of PI3K and AKT were detected.The overexpression of PTPRZ1 can regulate the apoptosis and activity of oral mucosal fibroblasts induced by ANE in a dose-dependent manner,and PTPRZ1 can regulate oral mucosal fi-broblasts by activating the PI3K/AKT signaling pathway of oral mucosal fibroblasts,promoting fibrosis and aggravating the disease.

Along with the increasing quantity of patients with end-stage liver diseases year by year, as an efficacious treatment, the safety and efficacy of liver transplantation are critical issues to be considered. In addition, liver transplant techniques have become a new research hot spot. In recent years, liver transplant techniques are constantly innovating and developing with the unremitting efforts of researchers. Researchers have successively developed multiple liver transplant techniques, such as split liver transplantation, ischemia-free liver transplantation, liver xenotransplantation, domino liver transplantation, delayed total hepatectomy combined with liver resection and segment Ⅱ-Ⅲ liver transplantation, heterotopic auxiliary liver transplantation on splenic fossa and magnetic anastomosis. It has laid a foundation for expanding the donor pool, improving clinical efficacy of liver transplantation and enhancing the quality of life of liver transplant recipients. In this article, the exploration, development, innovation and improvement of liver transplant techniques were reviewed and prospected, aiming to provide reference for clinical application of liver transplantation.

Objective:To compare the biomechanical properties of dynamic hip screw (DHS), traditional cannulated compression screw (CCS) configuration, traditional CCS configuration+medial locking plate and compression buttress screw (CBS) in the treatment of femoral neck fracture by finite element analyses.Methods:A simulation model of Pauwels type Ⅲ femoral neck fracture with discontinuous medial cortex was established by the finite element method. The maximum displacement, maximum principal stress, normal form equivalent stress, hip varus angle and fracture end stress were compared between DHS (group A), traditional CCS configuration (group B), traditional CCS configuration+medial locking plate (group C) and CBS (group D) in the simulation model.Results:In the internal fixation model in groups A, B, C and D, respectively, the maximum displacement of the femur was 0.41 mm, 2.04 mm, 0.94 mm and 0.30 mm; the maximum displacement of internal fixation 0.34 mm, 1.18 mm, 0.84 mm and 0.22 mm; the peak normal form stress of internal fixation 83.6 MPa, 231.4 MPa, 259.8 MPa and 194.8 MPa; the maximum principal stress of internal fixation 52.3 MPa, 216.3 MPa, 151.7 MPa and 74.6 MPa; the maximum normal form stress of the femur 101.1 MPa, 282.3 MPa, 100.5 MPa and 181.2 MPa; the maximum principal stress 99.7 MPa, 201.0 MPa, 60.9 MPa and 56.1 MPa; the axis angle of the femoral neck after loading 179.55°, 176.97°, 179.66° and 179.64°; the normal form equivalent stress at the fracture end ranged from 42.0 to 50.0 MPa, from 258.7 to 282.3 MPa, from 50.8 to 58.1 MPa, and from 45.3 to 60.4 MPa.Conclusion:Considering stability, stress distribution and prevention of hip varus and femoral neck shortening, CBS may be a choice treatment for femoral neck fracture because it is comparable to DHS in mechanical stability.

Hepatocellular carcinoma (HCC) is the fifth most common cancers worldwide, which ranks as the second of cancer-related death. Each year, more than half of the new and death cases occur in China. Vascular invasion is one of the important biological characteristics of HCC. HCC with portal vein tumor thrombus is closely related to the prognosis of patients, but there is no consensus on the best treatment method.Based on domestic and foreign literatures, the authors discuss the current status and progress of treatment for HCC with portal vein tumor thrombus, in order to explore the optimal treatment.

Objective:To examine the effect of the "four-steps" treatment on infectious pancreatic necrosis(IPN).Methods:The data of 207 patients who were diagnosed with IPN from January 2013 to December 2017 at Department of Pancreaticobiliary Surgery, the First Affiliated Hospital of Harbin Medical University were analyzed retrospectively. Among 207 patients, 132(63.8%) were males and 75(36.2%) were females. The median age was 45 years old (range: 19 to 80 years old). One hundred and fifty-eight patients(76.3%) suffered severe acute pancreatitis and 49 patients(23.7%) suffered moderately severe acute pancreatitis. Percutaneous catheter drainage(PCD) was performed on all the patients(Step 1). Patients received "four-steps" minimally invasive treatment strategy in step-up group(173 patients). The following steps after PCD were mini-incision access pancreatic necrosectomy(MIAPN) (Step 2), sinus tract endoscopic debridement and(or) PCD for residual infections(Step 3) and finally conventional open pancreatic necrosectomy(OPN) (Step 4). Patients(34 cases) received conventional open pancreatic necrosectomy after invalided PCD in OPN group. The perioperative parameters and prognosis were compared between Step-up group and OPN group. Normally distributed quantitative variables were analyzed by t-test, non-normally distributed quantitative variables were analyzed by Wilcoxon chi-square test and categorical variables were analyzed by χ 2 test or Fisher exact test, respectively. Results:The basic characteristics of the two groups of patients were similar, but the referral rate of patients and the rate of preoperative 3 days organ failure in the OPN group were significantly higher than those of step-up group patients(47.1% vs. 28.9%, χ 2=4.313, P=0.038; 26.5% vs. 9.2%, χ 2=2.819, P=0.011). The frequency of PCD and the number of PCD tube (root) were less than those in the step-up group(1(1) vs. 2(1), Z=-3.373, P=0.018; 2(1) vs. 3(2), Z=-2.208, P=0.027). Compared with the OPN group, the interval time from onset to surgery and the MIAPN operation time were significantly shorter in the step-up group(29(15) days vs. 36(17)days, Z=-0.567, P=0.008; 58(27)minutes vs. 90(56)minutes, Z=-3.908, P<0.01); postoperative mortality was lower(5.8% vs.17.6%, χ 2=4.070, P=0.044); the overall incidence of postoperative complications was reduced(23.1% vs. 55.9%, χ 2=14.960, P<0.01) and the incidence of new-onset organ failure was decreased after operation in the step-up group(37.5% vs.47.4%, χ 2=7.133, P=0.007). The incidence of local abdominal complications (pancreatic fistula, intra-abdominal hemorrhage, gastrointestinal fistula) showed no significant difference between the two groups ( P>0.05). Fewer patients required ICU treatment after operation in the step-up group compared with OPN group(22.0% vs. 44.1%, χ 2=6.204, P=0.013). Patients in the Step-up group has shorter hospital stay than patients in OPN group (46(13) days vs. 52(13)days, Z=-1.993, P=0.046). Conclusions:The clinical effects of "four-steps" exhibited the superiority of minimally invasive treatment of IPN.And MIAPN is a simple, safe and effective procedure to remove pancreatic necrotic tissue and decrease complications.

Objective:To examine the effect of the "four-steps" treatment on infectious pancreatic necrosis(IPN).Methods:The data of 207 patients who were diagnosed with IPN from January 2013 to December 2017 at Department of Pancreaticobiliary Surgery, the First Affiliated Hospital of Harbin Medical University were analyzed retrospectively. Among 207 patients, 132(63.8%) were males and 75(36.2%) were females. The median age was 45 years old (range: 19 to 80 years old). One hundred and fifty-eight patients(76.3%) suffered severe acute pancreatitis and 49 patients(23.7%) suffered moderately severe acute pancreatitis. Percutaneous catheter drainage(PCD) was performed on all the patients(Step 1). Patients received "four-steps" minimally invasive treatment strategy in step-up group(173 patients). The following steps after PCD were mini-incision access pancreatic necrosectomy(MIAPN) (Step 2), sinus tract endoscopic debridement and(or) PCD for residual infections(Step 3) and finally conventional open pancreatic necrosectomy(OPN) (Step 4). Patients(34 cases) received conventional open pancreatic necrosectomy after invalided PCD in OPN group. The perioperative parameters and prognosis were compared between Step-up group and OPN group. Normally distributed quantitative variables were analyzed by t-test, non-normally distributed quantitative variables were analyzed by Wilcoxon chi-square test and categorical variables were analyzed by χ 2 test or Fisher exact test, respectively. Results:The basic characteristics of the two groups of patients were similar, but the referral rate of patients and the rate of preoperative 3 days organ failure in the OPN group were significantly higher than those of step-up group patients(47.1% vs. 28.9%, χ 2=4.313, P=0.038; 26.5% vs. 9.2%, χ 2=2.819, P=0.011). The frequency of PCD and the number of PCD tube (root) were less than those in the step-up group(1(1) vs. 2(1), Z=-3.373, P=0.018; 2(1) vs. 3(2), Z=-2.208, P=0.027). Compared with the OPN group, the interval time from onset to surgery and the MIAPN operation time were significantly shorter in the step-up group(29(15) days vs. 36(17)days, Z=-0.567, P=0.008; 58(27)minutes vs. 90(56)minutes, Z=-3.908, P<0.01); postoperative mortality was lower(5.8% vs.17.6%, χ 2=4.070, P=0.044); the overall incidence of postoperative complications was reduced(23.1% vs. 55.9%, χ 2=14.960, P<0.01) and the incidence of new-onset organ failure was decreased after operation in the step-up group(37.5% vs.47.4%, χ 2=7.133, P=0.007). The incidence of local abdominal complications (pancreatic fistula, intra-abdominal hemorrhage, gastrointestinal fistula) showed no significant difference between the two groups ( P>0.05). Fewer patients required ICU treatment after operation in the step-up group compared with OPN group(22.0% vs. 44.1%, χ 2=6.204, P=0.013). Patients in the Step-up group has shorter hospital stay than patients in OPN group (46(13) days vs. 52(13)days, Z=-1.993, P=0.046). Conclusions:The clinical effects of "four-steps" exhibited the superiority of minimally invasive treatment of IPN.And MIAPN is a simple, safe and effective procedure to remove pancreatic necrotic tissue and decrease complications.

Objective To investigate the advantage of the technique of static compression screws with medial support using one ordinary cannulated compression screw (OCCS) and 2 headless cannulated compression screws (HCCSs) in reducing complications in the treatment of vertical femoral neck fractures.Methods From December 2014 to July 2017,79 patients were treated at Department of Orthopaedics,The Sixth People's Hospital of Shanghai for vertical femoral neck fractures.They were 51 men and 28 women,aged from 20 to 65 years (average,49.1 years).Their injury involved 45 left sides and 34 right sides.Of them,37 were treated with one OCCS at the top and 2 HCCSs at the bottom of a triangle arrangement for fixation of the vertical femoral neck fracture (the experimental group);the other 42 were treated with 3OCCSs at a triangle arrangement for fixation of the vertical femoral neck fracture (the control group).Their fracture healing and complications were followed up at postoperative 6 weeks,3,6 12,18,24 months and any time of discomfort by anteroposterior and lateral X-ray films of the knee joint.Results The 2 groups were compatible due to insignificant differences between their preoperative general data (P ＞ 0.05).This cohort was followed up for 9 to 24 months (average,17.5 months).Of them,52 achieved fracture union.Of the 27 patients who failed,8 were in the experimental group (21.6％) and 19 in the control group (45.2％),showing a significant difference in the rate of failure between the 2 groups (P ＜ 0.05).In the experimental group,the rate of nonunion was 8.1％ (3/37),the rate of implant failure 18.9％ (7/37),and the rate of fermoral neck varus 8.1％ (3/37),all significantly lower than those in the control group [26.2％ (11/42),40.5％ (17/42) and 23.8％ (13/42),respectively] (P ＜0.05).Conclusion For treatment of vertical femoral neck fractures,the technique of static compression screws with medial support is not only easy but also leads to a lower rate of complications.

Objective:To investigate the significance of periodontal treatment on the levels of MMP-3 and IFN-γin the serum of patients with oral lichen planus(OLP) and chronic periodontitis(CP) before and after treatment.Methods:60 patients with erosion OLP and CP were divided into 2 groups randomly (n =30).The patients in experimental group received basic periodontal treatment combined with drug therapy,those in control group received drug therapy only.Before and after treatment the periodontal indexes of PD,AL,BI and PLI were measured in the experimental group,the levels of MMP-3 and IFN-γ in serum were tested by ELISA in the 2 groups,the differences of the data between 2 groups were statistically analysed.Results:After treatment the periodontol indexes were decreased in the experimental group(P ＜ 0.05),the serum MMP-3 and IFN-γ levels were lower than those before treatment in 2 groups(P＜0.05),and the decline of MMP-3 and IFN-γ in experimental group was more obvious than those in the control group (P＜0.05).Conclusion:Periodontal initial therapy has positive influence on the treatment of OLP and can reduce the level of inflammation.