BACKGROUND: FG loop (FGL) is a core active peptide fragment of neural cell adhesion molecule (NCAM), which can directly act on fibroblast growth factor receptor 1 (FGFR1) to activate NCAM signal pathway.OBJECTIVE: To observe the effects of synthetic peptides FGL on PC12 cells proliferation and apoptosis.METHODS: ①PC12 cells proliferation and apoptosis: The cultured PC12 cells were divided into control group and experiment group. The experimental group was added with 1% FGL peptide solution. The control group was pre-coated with poly-lysine plates. The cells were cultured 1, 3, 5, 7, 9 d respectively to detect cell proliferation by using Cell Counting Kit-8. ②PC12 apoptosis and nuclear factor kappa B mRNA detection: The PC12 cells were divided into normal group, experimental group and injury group. H2O2 was added into the injury group for 16 hours stimulation. In the experimental group, H2O2 and FGL were used for 16 hours stimulation. The cell apoptosis were detected by flow cytometry; mRNA expression of nuclear factor kappa B was detected by quantitative fluorescent polymerase chain reaction.RESULTS AND CONCLUSION: PC12 cells cocultured with FGL peptide grow well, which indicates that FGL peptides can promote PC12 cell proliferation and inhibit PC12 cell apoptosis, as well as decrease mRNA expression of nuclear factor kappa B.

Objective To investigate the vascular endothelial growth factor (VEGF) expression level by chondrocytes isolated from patients with osteoarthritis (OA) in hip or femoral neck fracture (FNF) and explore the effect of synovial fluid from OA or FNF on secretion of VEGF. Methods The cartilage tissues were collected from 12 patients with OA in hip and 8 patients with FNF. Cartilage was stained with HIM and Safranin O/Fast Green (S/F) method. The damage of cartilage was evaluated using Mankin scores.Cathepsin B which was selected for cell dedifferentiation monitoring marker and VEGF level was detected in the supernatant fluid. The synovial fluid from OA, FNF and DMEM were respectively added to the culture medium to explore their effects on regulating VEGF. Results Cartilage the Mankin scores of OA group were higher than that of FNF group. Chondrocytes gradually lost their original spherical appearance, with Cathepsin B upregulated while VEGF downregulated. The OA synovial fluid can stimulate chongdrocytes to secrete more VEGF than the one from patients with FNF. However, chondrocytes gradually produced less VEGF after passaging. Conclusion Mankin scores had good correlation with chondrocytes' VEGF production in the early stage of primary culture. Chondrocytes showed quick dedifferentiation characteristics in vitro. OA synovial fluid showed abig ger capability in stimulating chondrocytes to express more VEGF, which might indicate that OA synovial fluid participated in the pathological process of OA.

Trypsin as an important serine protease has been widely used in food, pharmaceutical and tanning industries. In this study, we successfully expressed trypsin (cloning from Streptomyces griseus ATCC10137) in Streptomyces lividans TK24 and comparatively investigated its enzymatic properties. Specifically, applying S. griseus ATCC 10137 genome as template, we obtained the sprT gene and sub-cloned it into the expression plasmid pIJ86, generating the recombinant strain S. lividans TK24/pIJ86-sprT. When cultivated in R2YE and SELF, the activity of rSGT reached 9.21 U/mL and 8.61 U/mL, respectively. Meanwhile, the results of the enzymatic analysis showed that rSGT exhibited a higher acid tolerance and a higher specificity to hydrolyze amide bonds compared with bovine trypsin (BT). In addition, Zn2+ and organic solvents up-regulated esterase and amidase of rSGT. Taken together, the results obtained herein provide meaningful information for further modification of rSGT and its industrial application.
Fermentation ; Recombinant Proteins ; biosynthesis ; genetics ; Streptomyces griseus ; enzymology ; Streptomyces lividans ; genetics ; metabolism ; Trypsin ; biosynthesis ; genetics

Objective:To explore the correlation between fibular head height and varus knee osteoarthritis occurrence and severity.Methods:A retrospective analysis was performed on 618 participants (618 knees, 184 males and 434 females, mean age 61.12±10.98 years) who underwent standard weight-bearing full-leg radiographs and were diagnosed as non-knee osteoarthritis or varus knee osteoarthritis from January 2019 to June 2019. Knee osteoarthritis was diagnosed according to Kellgren-Lawrence grading: 0-I grades were diagnosed as non-osteoarthritis, II-IV grades were diagnosed as osteoarthritis. Joint line convergence angle (JLCA), medial proximal tibial angle (MPTA) and hip-knee-ankle angle were measured on X-rays to reflect varus deformity. The fibular head height was defined as the vertical distance from upper edge of fibular head to lateral tibial plateau. Patients were divided into 5 groups according to Kellgren-Lawrence grading. Differences of age, gender, height, weight, body mass index, varus deformity (JLCA, MPTA and hip-knee-ankle angle) between Kellgren-Lawrence 0-IV grades were compared. Ordinal logistic regression was performed to analyze the correlation between fibular head height and Kellgren-Lawrence grades. Pearson's correlation analysis was used for the correlation among fibular head height, JLCA, MPTA and hip-knee-ankle angle, and the main factor of JLCA, MPTA and hip-knee-ankle angle was extracted by factor analysis. Multiple linear regressions were used to analyze the correlation between fibular head height and varus deformity score.Results:There were 68, 66, 97, 98, 289 participants in Kellgren-Lawrence grades 0-IV respectively that was 134 participants were diagnosed as non-osteoarthritis and 484 participants were diagnosed as osteoarthritis. Fibular head height and MPTA showed a decreasing trend ( F=129.076, 24.875; P<0.001) while JLCA and hip-knee-ankle angle showed an increasing trend ( F=414.346, 105.996; P<0.001) with the increase in Kellgren-Lawrence grading. Age, body mass index and fibular head height are influencing factors of Kellgren-Lawrence grading with OR(95%CI) were 1.116(1.093, 1.141), 1.363(1.060, 1.754), 0.617(0.575, 0.662) . Fibular head height was negatively correlated with JLCA and hip-knee-ankle angle ( r=-0.641, -0.478; P<0.001) , respectively, and positively correlated with MPTA ( r=0.320, P<0.001). There were significant correlations between age, fibular head height and the varus deformity score ( β=0.274, -0.457; P<0.001). Conclusion:Fibular head height of patients with varus knee osteoarthritis is lower than that of non-osteoarthritis. In addition to age and body mass index, fibular head height is a risk factor for varus knee osteoarthritis occurrence. The smaller the fibular head height is, the more serious the osteoarthritis severity and varus deformity are.

Objective:To analyze the risk factors for rotator cuff tear and evaluate the corresponding prediction efficacy.Methods:A case-control study was conducted in 69 patients with rotator cuff tear admitted to Affiliated Hospital of Qingdao University from June 2020 to June 2021 (rotator cuff tear group) and 51 normal volunteers or medical examiners (normal control group). There were 55 males and 65 females, with the age range of 34-77 years [(58.2±7.2)years]. Body mass index (BMI) ranged from 19.5-32.4 kg/m 2 [(25.4±2.5)kg/m 2]. Univariate analysis was performed for the correlation of gender, age, history of hypertension, history of smoking, history of diabetes, BMI, angle of humeral greater tuberosity and notch angle of humeral greater tuberosity with rotator cuff tear in the two groups. Factors with statistically significant differences were included in multivariate Logistic regression analysis to determine the independent risk factors for rotator cuff tear. Spearman correlation analysis was used to find factor correlation between the two groups. The receiver operating characteristic (ROC) curve of relevant factors for the diagnosis and prediction of rotator cuff tear was analyzed. Results:Univariate analysis showed that age, angle of humeral greater tuberosity and notch angle of humeral greater tuberosity related to rotator cuff tear (all P<0.05). On the contrary, gender, history of hypertension, history of smoking, history of diabetes and BMI were not correlated with rotator cuff tear (all P>0.05). Multivariate Logistic regression analysis showed significant correlations of angle of humeral greater tuberosity and notch angle of humeral greater tuberosity with rotator cuff tear (all P<0.05). Spearman correlation analysis showed that age was not correlated with angle of humeral greater tuberosity and notch angle of humeral greater tuberosity ( r=0.09, 0.13, all P>0.05), but there was significant positive correlation between angle of humeral greater tuberosity and notch angle of humeral greater tuberosity ( r=0.76, P<0.01). When the optimal cutoff values of angle of humeral greater tuberosity and notch angle of humeral greater tuberosity were 70.05° and 150.55°, the area under the ROC curve (AUC) for predicting rotator cuff tear was 0.79 (95% CI 0.71-0.87, P<0.01) and 0.81 (95% CI 0.74- 0.89, P<0.01). Conclusions:Angle of humeral greater tuberosity and notch angle of humeral greater tuberosity are independent factors for rotator cuff tear, and larger angles suggest higher prevalence of rotator cuff tear. Besides, the notch angle of humeral greater tuberosity has relatively better predictive performance.

Objective:To compare the clinical efficacy between the pressing tendon suture with a lateral anchor and the knotted suture with a lateral anchor in the treatment of severe rotator cuff tear under shoulder arthroscopy.Methods:A retrospective study was conducted of the 42 patients who had been treated at Department of Orthopedic Sports Medicine, Affiliated Hospital to Qingdao University from December 2018 to December 2019 for severe rotator cuff tear. They were 13 males and 29 females, with an age of (58.3±10.1) years (from 32 to 74 years). The injury was on the right side in 26 cases and on the left side in 16 cases. Of them, 22 received pressing tendon suture with a lateral anchor under shoulder arthroscopy and 20 knotted suture with a lateral anchor under shoulder arthroscopy. The flexion, abduction and external rotation of the shoulder, Visual Analog Scale (VAS) pain score, University of California-Los Angeles (UCLA) score, Constant-Murley shoulder score, American Shoulder and Elbow Surgeons (ASES) score and imaging MRI Sugaya grading were compared between the 2 groups 12 months after operation.Results:There was no significant difference in the preoperative general data between the 2 groups, showing comparability between them ( P>0.05). At 12 months after operation, the pressing tendon suture group had better abduction and flexion of the shoulder, a lower VAS pain score and a higher ASES score than the knotted suture group, but the differences were insignificant ( P>0.05). At 12 months after operation, the pressing tendon suture group achieved significantly better external rotation (39.2°±11.7°) and significantly higher UCLA score (28.1±4.7) and Constant-Murley shoulder score (77.0±9.3) than the knotted suture group (29.8°±14.6°, 22.1±5.7 and 66.4±11.0) ( P<0.05). At 12 months after operation, the imaging MRI Sugaya grading was significantly lower for the pressing tendon suture group than that for the knotted suture group ( P<0.05). Conclusion:In the treatment of patients with severe rotator cuff tear under shoulder arthroscopy, the pressing tendon suture with a lateral anchor may lead to better clinical prognosis than the knotted suture with a lateral anchor.

Bone defects caused by different causes such as trauma, severe bone infection and other factors are common in clinic and difficult to treat. Usually, bone substitutes are required for repair. Current bone grafting materials used clinically include autologous bones, allogeneic bones, xenografts, and synthetic materials, etc. Other than autologous bones, the major hurdles of rest bone grafts have various degrees of poor biological activity and lack of active ingredients to provide osteogenic impetus. Bone marrow contains various components such as stem cells and bioactive factors, which are contributive to osteogenesis. In response, the technique of bone marrow enrichment, based on the efficient utilization of components within bone marrow, has been risen, aiming to extract osteogenic cells and factors from bone marrow of patients and incorporate them into 3D scaffolds for fabricating bone grafts with high osteoinductivity. However, the scientific guidance and application specification are lacked with regard to the clinical scope, approach, safety and effectiveness. In this context, under the organization of Chinese Orthopedic Association, the Expert consensus for the clinical application of autologous bone marrow enrichment technique for bone repair ( version 2023) is formulated based on the evidence-based medicine. The consensus covers the topics of the characteristics, range of application, safety and application notes of the technique of autologous bone marrow enrichment and proposes corresponding recommendations, hoping to provide better guidance for clinical practice of the technique.

Infectious bone defect is bone defect with infection or as a result of treatment of bone infection. It requires surgical intervention, and the treatment processes are complex and long, which include bone infection control,bone defect repair and even complex soft tissue reconstructions in some cases. Failure to achieve the goals in any step may lead to the failure of the overall treatment. Therefore, infectious bone defect has been a worldwide challenge in the field of orthopedics. Conventionally, sequestrectomy, bone grafting, bone transport, and systemic/local antibiotic treatment are standard therapies. Radical debridement remains one of the cornerstones for the management of bone infection. However, the scale of debridement and the timing and method of bone defect reconstruction remain controversial. With the clinical application of induced membrane technique, effective infection control and rapid bone reconstruction have been achieved in the management of infectious bone defect. The induced membrane technique has attracted more interests and attention, but the lack of understanding the basic principles of infection control and technical details may hamper the clinical outcomes of induced membrane technique and complications can possibly occur. Therefore, the Chinese Orthopedic Association organized domestic orthopedic experts to formulate An evidence-based clinical guideline for the treatment of infectious bone defect with induced membrane technique ( version 2023) according to the evidence-based method and put forward recommendations on infectious bone defect from the aspects of precise diagnosis, preoperative evaluation, operation procedure, postoperative management and rehabilitation, so as to provide useful references for the treatment of infectious bone defect with induced membrane technique.