Large-Dynamic-Range Ocular Aberration Measurement Based on Deep Learning with a Shack-Hartmann Wavefront Sensor.

The Shack-Hartmann wavefront sensor (SHWFS) is widely utilized for ocular aberration measurement. However, large ocular aberrations caused by individual differences can easily make the spot move out of the range of the corresponding sub-aperture in SHWFS, rendering the traditional centroiding method ineffective. This study applied a novel convolutional neural network (CNN) model to wavefront sensing for large dynamic ocular aberration measurement. The simulation results demonstrate that, compared to the modal method, the dynamic range of our method for main low-order aberrations in ocular system is increased by 1.86 to 43.88 times in variety. Meanwhile, the proposed method also has the best measurement accuracy, and the statistical root mean square (RMS) of the residual wavefronts is 0.0082 ± 0.0185 λ (mean ± standard deviation). The proposed method generally has a higher accuracy while having a similar or even better dynamic range as compared to traditional large-dynamic schemes. On the other hand, compared with recently developed deep learning methods, the proposed method has a much larger dynamic range and better measurement accuracy.

[Binocular loupe assisted mini-lateral and medial incisions in lateral position for release of elbow stiffness].

Objective: To analyze the effectiveness of binocular loupe assisted mini-lateral and medial incisions in lateral position for the release of elbow stiffness. Methods: The clinical data of 16 patients with elbow stiffness treated with binocular loupe assisted mini-internal and external incisions in lateral position release between January 2021 and December 2022 were retrospectively analyzed. There were 9 males and 7 females, aged from 19 to 57 years, with a median age of 33.5 years. Etiologies included olecranon fracture in 6 cases, elbow dislocation in 4 cases, medial epicondyle fracture in 2 cases, radial head fracture in 4 cases, terrible triad of elbow joint in 2 cases, supracondylar fracture of humerus in 1 case, coronoid process fracture of ulna in 1 case, and humerus fracture in 1 case, with 5 cases presenting a combination of two etiologies. The duration of symptoms ranged from 5 to 60 months, with a median of 8 months. Preoperatively, 12 cases had concomitant ulnar nerve numbness, and 6 cases exhibited ectopic ossification. The preoperative range of motion for elbow flexion and extension was (58.63±22.30)°, the visual analogue scale (VAS) score was 4.3±1.6, and the Mayo score was 71.9±7.5. Incision lengths for both lateral and medial approaches were recorded, as well as the occurrence of complications. Clinical outcomes were evaluated using Mayo scores, VAS scores, and elbow range of motion both preoperatively and postoperatively. Results: The lateral incision lengths for all patients ranged from 3.0 to 4.8 cm, with an average of 4.1 cm. The medial incision lengths ranged from 2.4 to 4.2 cm, with an average of 3.0 cm. The follow-up duration ranged from 6 to 19 months and a mean of 9.2 months. At last follow-up, 1 patient reported moderate elbow joint pain, and 3 cases exhibited residual mild ulnar nerve numbness. The other patients had no complications such as new heterotopic ossification and ulnar nerve paralysis, which hindered the movement of elbow joint. At last follow-up, the elbow range of motion was (130.44±9.75)°, the VAS score was 1.1±1.0, and the Mayo score was 99.1±3.8, which significantly improved when compared to the preoperative ones ( t=-12.418, P<0.001; t=6.419, P<0.001; t=-13.330, P<0.001). Conclusion: The binocular loupe assisted mini-lateral and medial incisions in lateral position integrated the advantages of traditional open and arthroscopic technique, which demonstrated satisfying safety and effectivity for the release of elbow contracture, but it is not indicated for patients with posterior medial heterolateral heterotopic ossification.

Postoperative Prevalence and Risk Factors for Serum Hypokalemia in Patients with Primary Total Joint Arthroplasty.

OBJECTIVE: Regular monitoring of serum potassium after a total joint arthroplasty (TJA) is a form of routine examination that can help detect abnormal serum potassium levels and reduce the incidences of adverse events that may occur on account of postoperative hypokalemia. Previous studies rarely discussed hypokalemia after joint replacement. In the present study, our primary goal was to investigate the incidence and possible risk factors of hypokalemia after a total hip and knee replacement procedure was performed. METHODS: This study included patients who underwent a unilateral total knee or hip arthroplasty in our department between April 2017 and March 2018. Serum potassium levels pre and post operation were collected and retrospectively analyzed. The differences in age, gender, body mass index (BMI), history of diseases, red blood cell (RBC), hemoglobin, hematocrit, glomerular filtration rate, ejection fraction, blood glucose, urine creatinine, urea nitrogen, intraoperative blood loss, operation time, drainage, preoperative potassium, surgery type, were compared between those patients diagnosed with hypokalemia and their non-hypokalemia at different times post surgery. Thereafter, the risk factors of postoperative hypokalemia patients were analyzed using statistical procedure multiple logistic regression model. RESULTS: The risk of hypokalemia after TJA was 53.1%, while, that on the first, third, and fifth day after operation was 12.5%, 40.7%, and 9.6% respectively. The serum potassium level on the first, third, and fifth postoperative days was 3.84 ± 0.32, 3.59 ± 0.34, and 3.80 ± 0.32 mmol/l, respectively. However, the level on the third day appeared to be the lowest (p = 0.015) of them all. The independent risk factors for hypokalemia after a total hip and knee replacement were the level of preoperative serum potassium concentration (p = 0.011), preoperative red blood cells counts (p = 0.027), and history of diabetes (p = 0.007). CONCLUSION: Regular monitoring of serum potassium concentration should be performed post TJA. We need to pay more attention to the patient's preoperative potassium levels along with their red blood cell counts especially in patients diagnosed with type 2 diabetes mellitus.

Kondo scattering in underdoped Nd1-xSrxNiO2 infinite-layer superconducting thin films.

The recent discovery of superconductivity in infinite-layer nickelates generates tremendous research endeavors, but the ground state of their parent compounds is still under debate. Here, we report experimental evidence for the dominant role of Kondo scattering in the underdoped Nd1-xSrxNiO2 thin films. A resistivity minimum associated with logarithmic temperature dependence in both longitudinal and Hall resistivities are observed in the underdoped Nd1-xSrxNiO2 samples before the superconducting transition. At lower temperatures down to 0.04 K, the resistivities become saturated, following the prediction of the Kondo model. A linear scaling behavior [Formula: see text] between anomalous Hall conductivity [Formula: see text] and conductivity [Formula: see text]is revealed, verifying the dominant Kondo scattering at low temperature. The effect of weak (anti-)localization is found to be secondary. Our experiments can help in clarifying the basic physics in the underdoped Nd1-xSrxNiO2 infinite-layer thin films.

Analysis of the curative effect and prognostic factors in patients with scapular fracture with surgical indications after conservative treatment: a case series and clinical outcomes.

Background: The choice of treatment for scapular fractures is a topic worth discussing. The type of scapular fracture is often complex, and more and more scholars prefer surgical treatment to obtain better shoulder joint function. In addition, because of the rich blood supply and muscles of the scapula, some scholars believe that simple suspension can also achieve satisfactory clinical effects. The aim of this study was to investigate the curative effect and prognostic factors of patients with scapular fracture with indications for surgery after receiving conservative treatment. Methods: Patients with scapular fracture who did not receive surgical treatment from July 2016 to May 2021 were recruited from the orthopedic trauma database of Nanjing Gulou Hospital, and the data from patients with indications for surgery were screened out for a retrospective analysis. The data were obtained from the database of orthopaedic trauma patients in Nanjing Drum Tower Hospital. The relevant data were recorded during telephone and video follow-up visits. Linear regression was used to analyze the factors associated with disabilities of the arm, shoulder and hand (DASH) score after receiving conservative treatment. Results: A total of 21 patients were included in the final statistical analysis. All patients were followed up for 31.0±20.3 (range, 6-63) months, aged 52.9±12.7 (range, 27-71) years. All fractures had clinical healing with a 100% recovery satisfaction rate. Outcome measures of efficacy [both DASH scores and visual analogue scale (VAS) scores], were correlated with whether the fracture involved the superior border of the scapular, were not associated with the following variables: age (P=0.18), Injury Severity Score (ISS) score (P=0.10), the glenopolar angle (GPA) value (P=0.76), superior shoulder suspensory complex (SSSC) injury (P=0.82), and glenoid fracture (P=0.84). The range of motion of the affected shoulder was significantly reduced compared to the healthy shoulder (P<0.01), but the range of forward flexion and elevation was not significantly different from that of the healthy shoulder (P>0.05). Patients with fractures not involving the superior border of the scapula had a much lower range of motion in the affected shoulder than in the healthy shoulder during abduction (P<0.05). Conclusions: The range of surgical indications for scapular fractures with scapular fractures involving the lower margin of the scapular can be appropriately narrowed. Some patients with scapular fracture who have surgical indications can regain satisfactory shoulder function after receiving conservative treatment.

Near infrared optically responsive Ag-Cu bimetallic 2D nanocrystals with controllable spatial structures.

The optical properties of cost-effective Ag-Cu bimetallic nanocrystals, with synergistically enhanced catalytic and biological activities, are limited within ultraviolet-visible region due to lack of morphology control. In order to overcome this constraint, two-dimensional (2D) Ag-Cu bimetallic heterostructures were designed and synthesized by a seed-mediated colloidal growth method. The conformal Cu domain was epitaxially deposited on Ag nanoplates with different spatial configuration under retention of their 2D shape. Both of the 2D Ag-Cu core@shell and Janus structures display tunable localized surface plasmon resonance from visible to near infrared regions. The results of catalytic reduction of 4-nitrophenol show that the 2D Ag-Cu core@shell structure has better synergistic catalytic performance than Janus structure and Ag plates. In addition to surface-related synergistically enhanced bactericidal performance, their antibacterial effect can also be significantly enhanced by near infrared light irradiation. These results indicate that 2D Ag-Cu heterostructures can benefit from both synergistically improved surface activity and great optical responsive characteristics.

[Analysis of risk factors of multiple fractures of limbs complicated with pleural effusion].

OBJECTIVE: To explore the risk factors of limb fracture complicated with pleural effusion, and to provide reference for the prevention of pleural effusion. METHODS: From January 2010 to December 2019, 137 patients with multiple limb fractures were treated surgically, including 102 males and 35 females, aged 16 to 92(48.34±15.85) years. Multiple limb fractures were defined as more than two limb fractures in the whole body, so the selected patients had complete clinical, impact and laboratory examination data before operation, including preoperative chest CT, gender, age, body mass index(BMI), hematocrit(HCT), American Society of Anesthesiologists(ASA), injury severity score (ISS), smoking history of operation, history of diabetes, history of hypertension, admission to operation time, fracture site, platelet count, albumin, C-reactive protein and D-dimer. Whether the patient was complicated with pleural effusion, calculate the amount of pleural effusion were recorded, and the relevant risk factors were statistically analyzed. RESULTS: All limb fractures received surgical treatment. The incision healed well after operation, and there were no complications such as wound infection, acute lung injury or acute respiratory distress syndrome. Multivariate regression analysis showed that ISS higher than 16(P=0.000), smoking history(P=0.001) and rib fracture(P=0.000) were the risk factors of multiple limb fractures complicated with pleural effusion. Multivariate linear regression analysis showed that smoking history, ISS and rib fracture were the risk factors for the increase of pleural effusion in multiple limb fractures. CONCLUSION: Multiple fractures of limbs combined with pleural effusion are related to ISS, smoking history and rib fracture;the amount of pleural effusion was related to smoking history, ISS and rib fracture. Patients with multiple fractures with ISS greater than 16, smoking history or rib fracture should be vigilant and intervene as soon as possible to reduce the risk of pleural effusion.

Event-Based Robust Optimal Consensus Control for Nonlinear Multiagent System With Local Adaptive Dynamic Programming.

This article investigates the robust optimal consensus for nonlinear multiagent systems (MASs) through the local adaptive dynamic programming (ADP) approach and the event-triggered control method. Due to the nonlinearities in dynamics, the first part defines a novel measurement error to construct a distributed integral sliding-mode controller, and the consensus errors can approximately converge to the origin in a fixed time. Then, a modified cost function with augmented control is proposed to deal with the unmatched disturbances for the event-based optimal consensus controller. Specifically, a single network local ADP structure with novel concurrent learning is presented to approximate the optimal consensus policies, which guarantees the robustness of the MASs and the uniform ultimate boundedness (UUB) of the neural network (NN) weights' estimation error and relaxes the requirement of initial admissible control. Finally, an illustrative simulation verifies the effectiveness of the method.

External fixation with bone cement implantation for open calcaneal fractures: A case series.

OBJECTIVE: The purpose of this study was to retrospectively evaluate patients who had open reduction, external fixation and bone cement implantation of open calcaneal fractures. METHODS: The records of 14 patients with open calcaneus fractures from January 2015 to January 2019 were reviewed retrospectively. Clinical evaluations consisting of AOFAS, MFS and EQ-5D VAS scores and radiological evaluations consisting of the height, width and length of the calcaneus as well as Bohler's and Gissane angle performed at 3 months, 1 year and the last follow-up postoperatively. Time to surgery, wound complications were recorded. RESULTS: Our study sample consisted of 9 males and 5 females with a mean age of 38.5 ± 9.8 years and a mean follow-up of 31.4 ± 7.7 months. The mean period from injury to surgery was 5.4 ± 1.9 days and the mean duration of hospitalization was 13.2 ± 4.5 days. The AOFAS, MFS and EQ-5D VAS scores were 92.5 ± 10.3, 84.1 ± 9.7 and 86.4 ± 15.1 respectively at the final follow-up. The Bohler's angle increased from (12.9 ± 3.1)° preoperatively to (28.5 ± 6.3)° at the final follow-up (P < 0.001), with the Gissane's angle from (104.5 ± 9.7)° to (116.4 ± 8.9)° (P < 0.001). One patients (7.1%) developed pin infections and one patient (7.1%) suffered from dorso-lateral hindfoot hypoaesthesia. There was complete fracture healing without secondary loss of reduction in all cases. CONCLUSION: External fixation with bone cement implantation is a valid alternative treatment for the management of displaced open calcaneal fractures with a low rate of complications. LEVEL OF EVIDENCE: IV, retrospective case series.

Single volar locking plating for the intra- and extra-articular distal radius fractures with dorsal metaphyseal comminution.

BACKGROUND: Volar locking plating remains a popular method for the surgical management of distal radius fractures. Dorsal metaphyseal comminution (DMC) is a common fracture pattern which weakens the stability during fracture fixation. In this study, we aimed to compare the radiographic and functional outcome of the intra- and extra-articular distal radius fractures with DMC following single volar locking plate fixation. MATERIALS AND METHODS: Patients suffered from a distal radius fracture with DMC were reviewed in the clinical database of the authors' institution between Jan 2016 and Jan 2020. The included patients were classified into the extra-articular (A3) group or the intra-articular (C2 and C3) group according to the AO/OTA system. The radiological parameters, wrist range of motion, and functional outcomes were evaluated following open reduction and volar locking plate fixation. RESULTS: A total of 130 patients were included in this study with a mean follow-up length of 17.2 months. Compared with the A3 fracture group, no significant fracture re-displacement or reduced wrist ROMs was observed in the C2 fractures after 12-month's follow-up. However, significantly decreased volar tilt (P = 0.003) as well as the extension/flexion ROMs were observed in the C3 fractures comparing to the A3 fractures. Most of the patients achieved an excellent (n = 75) or good (n = 51) Gartland and Werley wrist score. Four patients with C3 fractures resulted in a fair functional outcome due to a significant loss of volar tilt during follow-up. CONCLUSIONS: The single volar locking plate fixation provided sufficient stability for distal radius fractures with DMC, and resulted in similar radiological and functional outcomes in the intra-articular distal radius fractures with a simple articular component (C2 fractures) as those in the extra-articular fractures. Considering the intra-articular fractures with multifragmentary articular component (C3 fracture), despite of the subsequent loss of volar tilt, the majority of the patients achieved good to excellent wrist function following single volar locking plating. TRIAL REGISTRATION: This study has been registered on the ClinicalTrials.gov.

Plasma Fibrinogen as a Diagnostic Marker of Infection in Patients with Nonunions.

BACKGROUND: The timely and accurate diagnosis of infected nonunion is challenging, and there is a need for more efficient biomarkers. Previous studies have shown that fibrinogen plays an important role in mediating inflammation in bacterial infections and, therefore, could be a valuable biomarker for infected nonunion. The purpose of this study was to evaluate and compare the performance of plasma fibrinogen and other traditional blood markers for the diagnosis of infected nonunion. MATERIALS AND METHODS: We retrospectively studied 146 patients who underwent surgery for primary nonunion between January 2018 and January 2020. The patients were divided into those with infected nonunion (n = 55) and those with aseptic nonunion (n = 91). The preoperatively analyzed parameters were plasma fibrinogen, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) level, and white blood cell (WBC) count. Receiver operating characteristic (ROC) curve analysis was used to assess the sensitivity and specificity of the biomarkers, and Youden's index was calculated to determine their optimal cut-off values. RESULTS: The plasma fibrinogen values were significantly higher (p < 0.001) in the patients with infected nonunion than in those with aseptic nonunion. ROC curve analysis showed that plasma fibrinogen had a high value of area under the curve (0.816), which indicated that it had good diagnostic ability. Further, at the optimal threshold value of 2.75 g/L, plasma fibrinogen had the highest sensitivity (78.2%; 95% CI = 64.6-87.8) and good specificity (82.4%; 95% CI, 72.7-89.3). CONCLUSION: In comparison to the traditional markers of infection, plasma fibrinogen showed good diagnostic ability for the detection of infected nonunion. It may have potential as a practical and cost-efficient biomarker for the diagnosis of infected nonunion.

BDNF promoted osteoblast migration and fracture healing by up-regulating integrin ß1 via TrkB-mediated ERK1/2 and AKT signalling.

Brain-derived neurotrophic factor (BDNF) has been reported to participate in fracture healing, whereas the mechanism is still unclear. Since osteoblast migration is important for fracture healing, investigating effects of BDNF on osteoblasts migration may help to reveal its mechanism. Here, MC3T3-E1 cells were used in vitro while closed femur fracture mice were applied in vivo. Cells migration was assessed with Transwell assay. The protein expression was analysed by immunoblotting. X-ray and Micro-CT were performed at different time after fracture. Our results showed that BDNF promoted MC3T3-E1 cells migration, integrin ß1 expression and ERK1/2 and AKT phosphorylation. K252a, a specific inhibitor for TrkB, suppressed BDNF-induced migration, integrin ß1 expression and activation of ERK1/2 and AKT. PD98059 (an ERK1/2 inhibitor) and LY294002 (an AKT inhibitor) both inhibited BDNF-induced migration and integrin ß1 expression while integrin ß1 blocking antibody only suppressed cell migration. X-ray and Micro-CT analyses showed that the adenoviral carried integrin ß1 shRNA group had slower fracture healing at 7 and 21 days, but not 35 days compared to the control group. Thus, we proposed that BDNF stimulated MC3T3-E1 cells migration by up-regulating integrin ß1 via TrkB mediated ERK1/2 and AKT signalling, and this may help to enhance the fracture healing.

Incidence of and risk factors for the development of asymptomatic heterotopic ossification after elbow fracture fixation.

OBJECTIVE: This study was performed to investigate the incidence of and risk factors for asymptomatic heterotopic ossification (HO) after open reduction and internal fixation of elbow fractures. METHODS: This retrospective analysis involved 197 patients with elbow fractures treated operatively from 2014 to 2017 at our institution. Patient-related and clinical variables were recorded. Univariate analysis and multivariate logistic regression were performed to reveal independent risk factors for postoperative HO. In addition, a receiver operating characteristic (ROC) curve was performed to assess the ability of risk factors to predict the development of postoperative HO. RESULTS: The overall rate of asymptomatic HO after surgery was 18.78%. The incidence was highest in terrible triad injuries and lowest in capitellum fractures. Independent predictors of asymptomatic HO identified by the multivariate analysis were underlying diseases, fracture dislocation, and a prolonged operative time. The area under the ROC curve for underlying diseases, fracture dislocation, and a prolonged operative time were 0.593, 0.596, and 0.694, respectively. CONCLUSIONS: The incidence of postoperative asymptomatic HO in patients with elbow fractures is high. Clinicians should employ prophylaxis to avoid HO when treating patients with elbow fractures who have underlying diseases, fracture dislocation, or a prolonged operative time.

Usefulness of serum D­dimer for preoperative diagnosis of infected nonunion after open reduction and internal fixation.

PURPOSE: Infected nonunion after open reduction internal fixation (ORIF) is a serious complication. The aim of this study was to evaluate the usefulness of serum D-dimer for preoperative diagnosis of infected nonunion. PATIENTS AND METHODS: Patients undergoing debridement and external fixation for infected nonunion (n=32) and replacement of internal fixation due to aseptic failure (n=34) were enrolled and compared in this retrospective study. The optimum cutoff value of D-dimer for identification of infected nonunion was determined by calculating the Youden J statistic. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of four preoperative laboratory parameters-serum D-dimer level, white blood cell (WBC) count, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP)-for diagnosis of infected nonunion were compared. RESULTS: Serum D-dimer level was significantly higher in patients with infected nonunion than in patients with aseptic nonunion: 2.62 mg/mL (range, 0.13-11.90 mg/mL) vs 0.35 mg/mL (range, 0.07-6.46 mg/mL; p<0.001). WBC count, CRP, and ESR demonstrated sensitivity of 12.5% (95% CI: 4.08-29.93), 40.6% (95% CI: 24.22-59.21), and 56.3% (95% CI: 37.88-73.16), respectively, and specificity of 94.1% (95% CI: 78.94-98.97), 88.2% (95% CI: 71.61-96.16), and 85.3% (95% CI: 68.17-94.46), respectively. Using the Youden index, 1.70 mg/mL was determined as the optimal threshold value for serum D-dimer for the diagnosis of infected nonunion. The sensitivity and specificity of serum D-dimer (>1.70 mg/mL) were 75.0% (95% CI: 56.25-87.87) and 91.2% (95% CI: 75.19-97.69). CONCLUSIONS: Serum D-dimer level may be useful for preoperative prediction of infected nonunion in patients after ORIF.

The association between platelet indices and deep surgical site infection after open induction internal fixation for traumatic limb fractures.

OBJECTIVES: Deep surgical site infection (DSSI) is one of the most serious complications after open induction internal fixation (ORIF) for traumatic limb fractures. In this study, we aimed to investigate the diagnostic role of platelet indices (platelet count [PLT], mean platelet volume [MPV], and platelet distribution width [PDW]) in DSSI. PATIENTS AND METHODS: Data obtained between January 2011 and December 2017 in The Affiliated Drum Tower Hospital of Nanjing University Medical School from cases (n=29) with DSSI and fracture control subjects (n=29) matched for age, gender, and fracture type were analyzed. The white blood cell (WBC) count, neutrophil count, neutrophil percentage, and platelet indices from blood samples were compared between case and control groups. In addition, the cutoff value, sensitivity, and specificity were calculated by receiver-operating characteristic (ROC) curves. RESULTS: No significant differences were detected in demographic features, the WBC count, neutrophil count, neutrophil percentage, and MPV values between two groups (P>0.05). The PLT values were significantly higher in the case group than in the control group (303.00±139.27 vs 196.10±59.61 [109/µL], P=0.001). The PDW values of the case and control groups were 11.77±2.71 and 13.19±2.39%, respectively, and were significantly lower in the case group (P=0.001). ROC curve analysis suggested a cutoff point for PLT as 215.50 (109/µL, larger values indicate pathology) for the diagnosis of DSSI with the sensitivity and specificity of 79.3 and 72.4%, respectively. For PDW, the cutoff point was 10.35% (smaller values indicate patients) for the diagnosis of DSSI with the sensitivity and specificity of 37.9 and 96.6%, respectively. CONCLUSION: Our results suggest that PDW combined with PLT can be used as an important additional test for the diagnosis of DSSI after ORIF for traumatic limb fractures, thus reducing the cost and loss of time.

Inhibiting GIT1 reduces the growth, invasion, and angiogenesis of osteosarcoma.

BACKGROUND: GIT1, a scaffold protein with ubiquitous multi-domain, is involved in many cellular processes. In recent years, it was proved that GIT1 participated in various tumors' growth or metastasis. However, the biological function of GIT1 in osteosarcoma is still unclear. In this study, we aimed to investigate the role and mechanism of GIT1 in osteosarcoma. MATERIALS AND METHODS: Human osteosarcoma tissues were obtained to investigate the distribution of GIT1. Adequate osteosarcoma cells were stably infected with lentivirus to knockdown GIT1 level and then was used to carry out cell invasion and vascular endothelial growth factor (VEGF) assay in vitro. Orthotopic femoral osteosarcoma model was constructed to investigate the growth, invasion, and angiogenesis in vivo. Western blot was used to detect extracellular signal-regulated kinase (ERK1/2) activation and hypoxia-inducible factor-1 (HIF-1α) expression. RESULTS: In this study, we found that GIT1 was distributed in human osteosarcoma tissues and highly expressed in osteosarcoma (OS) cells. Knockdown of GIT1 inhibited cell invasion and VEGF release in vitro and suppressed tumor growth, invasion, and angiogenesis in vivo. Furthermore, knockdown of GIT1 substantially downregulated the protein levels of p-ERK and HIF-1α in OST cells and inhibition of p-ERK by PD98059 could significantly decrease the expression of HIF-1α and concentration of VEGF in GIT1-shRNA-treated cells. CONCLUSION: GIT1 knockdown can effectively inhibit the growth, invasion, and angiogenesis of osteosarcoma. Thus, GIT1 might act as an oncogenic factor in osteosarcoma and could be a potential molecular target for osteosarcoma gene therapy.

Chronic kidney disease can increase the risk of preoperative deep vein thrombosis in middle-aged and elderly patients with hip fractures.

BACKGROUND: Preoperative deep vein thrombosis (DVT) is a common complication in patients with hip fractures. Chronic kidney disease (CKD) as a frequent comorbidity in middle-aged and elderly patients with hip fractures is known to promote a proinflammatory and prothrombotic state. We aimed to identify whether CKD can increase the risk of DVT in middle-aged and elderly patients with hip fractures, as well as identify other risk factors. PATIENTS AND METHODS: We retrospectively studied 248 middle-aged and elderly patients with hip fractures who were admitted to our hospital from January 2016 to June 2017, meeting all the inclusion criteria. Doppler ultrasonography was used to diagnose DVT. Patients with CKD were classified into five stages according to the Kidney Diseases Outcomes Quality Initiative. We identified whether CKD could increase the occurrence of preoperative DVT in middle-aged and elderly patients with hip fractures and further investigated other independent risk factors for preoperative DVT by using univariate and multivariate analyses. RESULTS: The mean estimated glomerular filtration rate was 125.7±41.4 mL/min/1.73 m2. Briefly, 82.3% (n=204) had been diagnosed with normal kidney function, 11.7% (n=29) with mildly decreased kidney function, and 6.0% (n=15) with stage 3 and 4 CKD. In addition, of the 248 patients, 11.7% (n=29) developed DVT before surgery. Independent predictors of preoperative DVT identified by multivariate analyses were age, prolonged bedridden time, increased levels of fibrinogen, and lower estimated glomerular filtration rate. CONCLUSION: CKD can increase the risk rate of preoperative DVT in middle-aged and elderly patients with hip fractures. Additionally, age, prolonged bedridden time, and increased levels of fibrinogen were also independent risk factors for preoperative DVT in these patients. We should take preventive measures for these patients with risk factors in order to reduce the incidence of preoperative DVT.

Risk factors for increased postoperative drainage of calcaneal fractures after open reduction and internal fixation: An observational study.

Sufficient drainage is very important for preventing wound complications after open reduction and internal fixation (ORIF) of calcaneal fractures. However, the drainage amount varies among patients. The objective of this study was to identify factors associated with increased postoperative drainage after ORIF of calcaneal fractures.A retrospective study including 87 patients with 92 calcaneal fractures in our hospital was performed. Patients were divided into 2 groups based on whether they had increased drainage, which was defined as a total drainage of ≥340 mL (50th percentile). We gathered the following data on each patient: age; sex; smoking history; body mass index (BMI); American Society of Anesthesiologists (ASA) classification; fracture type; the time from injury to surgery; operative time; bone grafting; preoperative labs including prothrombin time (PT), activated partial thromboplastin time (APTT), hematocrit, and D-dimer level; and histories for hypertension, diabetes, and heart disease. Univariate analysis and multivariate logistic regression analysis were used to analyze the risk factors associated with increased drainage.Total drainage ranged from 105 to 1185 mL, and the average drainage for this cohort was 393.6 ±â€Š232.4 mL (mean ±â€Šstandard deviation). 57.6% (n = 53) of patients had increased drainage. Smoking history, Sanders type, operative time, and bone grafting were significantly associated with increased drainage on univariate analysis. Multivariate logistic regression analysis then demonstrated that active smoking and higher Sanders type were independent risk factors for increased drainage.Patients with calcaneal fractures who smoked or had a higher level of Sanders type had a higher risk of increased postoperative drainage. Therefore, we suggest that active precautions be taken for these patients to reduce the rate of postoperative wound complications.

BDNF regulates the expression and secretion of VEGF from osteoblasts via the TrkB/ERK1/2 signaling pathway during fracture healing.

Brain­derived neurotrophic factor (BDNF), a member of the neurotropic family, is expressed in osteoblast­like cells of a fracture callus, however, its role in fracture healing remains to be fully elucidated. Osteoblasts isolated from Sprague Dawley rats were stimulated by BDNF in a dose­ and time­dependent manner. Immunoblotting and immunofluorescence was used to detect the expression and distribution of targeted proteins. The concentration of vascular endothelial growth factor (VEGF) released in medium was determined using an ELISA. PD98059 and K252a were used to investigate the signaling pathways that may be involved. The present study demonstrated that BDNF was involved in fracture repair by controlling the expression and secretion of VEGF from osteoblasts, which predominantly drives angiogenesis during fracture healing. Tropomyosin­related kinase B (TrkB), the specific receptor of BDNF, was shown to be expressed at high levels in the osteoblasts. Following BDNF stimulation, TrkB and extracellular signal­regulated kinase 1/2 (ERK1/2) were rapidly activated. The inhibition of TrkB by K252a decreased the expression and secretion of VEGF, and suppressed the phosphorylation level of ERK1/2. PD98059, an antagonist of ERK1/2, elicited the same effects on VEGF from the BDNF­stimulated osteoblasts, however, it did not affect the phosphorylation of TrkB. In conclusion, during fracture healing, BDNF was found to stimulate the expression and secretion of VEGF from osteoblasts via the TrkB/ERK1/2 signaling pathway.