An ab initio study on the electronic excited states and photodissociation mechanism of bromocarbene molecule.

We used the internally contracted explicitly correlated multireference configuration interaction (icMRCI-F12) method combined with Davidson correction to conduct a high-precision ab initio study of CHBr. The spin-orbit coupling (SOC) is incorporated into the calculation. The 21 spin-free states split into 53 spin-coupled states of CHBr. The vertical transition energies and oscillator strengths are obtained of these states. The SOC effect on the equilibrium structures and the harmonic vibrational frequencies of the ground state X1A', the lowest triplet state a3A'' and the first excited singlet state A1A'' is investigated. The results reveal a significant effect of the SOC on the bond angle and the frequency of the bending mode of a3A''. The potential energy curves of electronic states of CHBr as functions of the H-C-Br bond angle, C-H bond length, and C-Br bond length, respectively, are also investigated. Based on the calculated results, the interactions between electronic states and photodissociation mechanism involved in CHBr in the ultraviolet region are explored. Our theoretical studies will shed light on the complicated interactions and dynamics of the electronic states of bromocarbenes.

HMGB1 can activate cartilage progenitor cells in response to cartilage injury through the CXCL12/CXCR4 pathway.

INTRODUCTION: Recent studies have suggested that cartilage progenitor cells (CPCs) could be activated and differentiated into chondrocytes to produce matrix and to restore the integrity of damaged cartilage after injury. However, the mechanism involved in CPC activation upon damage is still unclear. This study aims to investigate the role of high mobility group box chromosomal protein 1 (HMGB1) in both activation and migration of CPCs during cartilage injury. MATERIAL AND METHODS: Explants harvested from mature bovine stifle joints were used for impact injury. The proliferation and migration of CPCs were examined via confocal imaging. Gene and protein expression of Hmbg1, Cxcl12, and Cxcr4 was also examined by quantitative polymerase chain reaction (qPCR), ELISA, and western blot. Each experiment was repeated 3 times. ANOVA and Student's t-test were performed for statistical analysis. RESULTS: HMGB1 released from dead and damaged chondrocytes after an impact injury could activate CPCs in the superficial zone of cartilage and promote their migration and proliferation to injury sites. However, the block of HMGB1 activation with its specific binding inhibitor glycyrrhizin inhibits the proliferation and migration of CPCs. Further investigations demonstrate that HMGB1 promotes CPCs migration through the pathway of C-X-C motif chemokine 12 (CXCL12) and its receptor CXCR4. Quantitative analysis of HMGB1 in cell culture medium also indicates that CPCs may have a self-activation property after the HMGB1 released from dead cells has been exhausted. CONCLUSION: HMGB1 is a pivotal factor that could enhance the migration and proliferation of CPCs through the CXCL12/CXCR4 pathway after cartilage injury, which could provide useful information for cartilage repair and osteoarthritis treatment.

Overexpression of Wnt7b antagonizes the inhibitory effect of dexamethasone on osteoblastogenesis of ST2 cells.

INTRODUCTION: It is well established that glucocorticoid-induced osteoporosis is highly associated with preosteoblast differentiation and function. This study is based on the premise that Wnt7b can promote bone formation through Wnt signalling pathway because it can stimulate preosteoblast differentiation and increase its activity. However, it is unknown whether Wnt7b can rescue the inhibited osteoblast differentiation and function caused by exogenous glucocorticoid. MATERIAL AND METHODS: In this study we used Wnt7b overexpression ST2 cells to explore whether Wnt7bcan rescue the inhibited osteoblast differentiation and function, which can provide strong proof to investigate a new drug for curing the glucocorticoid induced osteoporosis. RESULTS/CONCLUSION: We found that Wnt7b can rescue the suppressed osteoblast differentiation and function without cell viability caused by dexamethasone.

[Study on the length and quality of prostate biopsy tissue strips].

OBJECTIVE: To improve the diagnostic yield of prostate biopsy, which we can achieve by puncture more sites and number of cores, another way to obtain more tissue is to take longer tissue strips. In this study, we evaluated the effect of strip length on cancer diagnosis by needle biopsy and derived a cutoff value of strip length to improve cancer detection. METHODS: The pathological reports of 754 patients with suspected prostate cancer who underwent transperineal prostate biopsy were retrospectively analyzed. The age, serum prostate specific antigen (PSA), prostate volume, Gleason score and tissue strip length were analyzed. The length of the tissue strip was compared between the biopsy positive patients and the biopsy negative patients, and the patients were divided into group A（biopsy positive group）and group B（biopsy negative group）, respectively. Statistical analysis of tissue strip lengths was performed to determine cutoff values for biopsy length quality. RESULTS: A total of 10 556 tissue strips were obtained from 754 patients, and 45.1 % of the patients were pathologically diagnosed as prostate cancer. The median length of the tissue strip was 10.5 (9.5, 12.5) mm, the median age was 69 (64,75) years, the median PSA was 12.4 (8.6, 20.8) µg/L, and the median prostate volume was 44.8 (30.5, 64.4) ml. The median length of tissue strips in group A and group B was 11 (10,13) mm and 10 (9,12) mm, respectively. Receiver operating characteristic (ROC) curve analysis was performed on the length of tissue strips in all cases, and the cutoff value of quality assurance was 11.8mm, the area under curve (AUC) was 0.82, and the cut-off value of quality assurance was 11.8mm. Sensitivity 71.4%, specificity 73.8%(P<0.001). CONCLUSIONS: In transperineal prostate biopsy, the cancer detection rate of tissue strips may increase with length. The results of ROC analysis showed that 11.8 mm was used as the cut-off value for quality assurance.

Efficacy and safety of platelet-rich plasma combined with hyaluronic acid versus platelet-rich plasma alone for knee osteoarthritis: a systematic review and meta-analysis.

PURPOSE: To systematically evaluate the curative efficacy and safety of platelet-rich plasma (PRP) combined with hyaluronic acid (HA) in the treatment of knee osteoarthritis (KOA), comparing with platelet-rich plasma alone. METHODS: Cochrane Library, PubMed, China National Knowledge Infrastructure (CNKI) and Embase were searched for randomized controlled trials (RCTs) and cohort studies regarding the efficacy and safety of platelet-rich plasma (PRP) combined with hyaluronic acid (HA) in the treatment of knee osteoarthritis (KOA) comparing with platelet-rich plasma alone before January 15, 2022. The methodological quality of the ultimately included studies was assessed comprehensively, and meta-analysis was implemented using RevMan 5.3 software. RESULTS: Thirteen articles (9 RCTs, 4 cohort studies), including 1118 patients, were covered. There was no significant difference between the PRP + HA therapy and PRP-alone therapy in VAS scores at 3 months, 6 months and 12 months, WOMAC total scores at 3 months and KOOS at 1 month and 6 months. Compared with PRP-alone therapy, PRP + HA therapy was associated with significantly better improvement in VAS scores at 1 month, WOMAC total scores at 6 months, KOOS at 3 months, IKDC scores at 6 months and Lequesne index scores at 3 and 6 months. However, the smallest treatment effect of VAS scores, WOMAC total scores, KOOS and IKDC scores did not exceed the minimum clinically important difference (MCID). However, PRP + HA therapy got a greater reduction in the rate of adverse events, compared with PRP-alone therapy. CONCLUSION: The results of this meta-analysis indicated that PRP + HA therapy was not found to be superior to PRP-alone therapy in pain relief and function improvement for patients with KOA. However, combined PRP with HA injections was generally safer than PRP injections alone, by assessing the incidence of adverse events.

Biomechanical study on parallel cannulated compression screw combined with medial buttress plate fixation and F-type cannulated compression screw fixation in Pauwels III femoral neck fracture：A finite element analysis. / å¹³è¡Œç©ºå¿ƒåŠ åŽ‹èžºé’‰è”åˆå† ä¾§æ”¯æ’‘é’¢æ¿ä¸ŽFåž‹ç©ºå¿ƒåŠ åŽ‹èžºé’‰å›ºå®šPauwels IIIåž‹è‚¡éª¨é¢ˆéª¨æŠ˜ç”Ÿç‰©åŠ›å­¦ç‰¹æ€§çš„æœ‰é™å ƒåˆ†æž.

OBJECTIVES: Pauwels III fracture is a kind of femoral neck fractures, in which the angle of the fracture line in the coronal plane and the upper edge of the acetabulum is more than 50°. Internal fixation for the treatment of femoral neck fractures is largely performed by cannulated compression screw (CCS), dynamic hip screw, or locking plate. This study aims to compare the biomechanical properties of parallel CCS combined with medial buttress plate fixation and F-type CCS fixation in the treatment of Pauwels III femoral neck fracture by finite element modeling and to determinate the most suitable procedure for such fractures. METHODS: A 52-year-old male volunteer, 176 cm in height and 72 kg in weight, with no history of hip joint, was selected. X-ray and CT examination confirmed that the morphology and bone condition of the right hip of the volunteer were normal. A simulation model of Pauwels III femoral neck fracture was established from the collected CT data of the right proximal femur of the volunteer by the finite element method. Four internal fixations were developed to treat the finite element model: Three CCSs in an inverted triangular parallel configuration combined with medial buttress plate model served as Group A, 2 CCSs in a vertical parallel configuration combined with medial buttress plate model served as Group B, 2 CCSs in a horizontal parallel configuration combined with medial buttress model served as Group C, and the "F" shaped CCS model served as Group D. The distribution of stress, the peak stress, the distribution and maximum of displacement of internal fixations and fracture ends in different models were evaluated. RESULTS: For Groups A, B, C, and D, the peak stresses on the internal fixation were 362.74, 586.84, 558.25, and 208.66 mPa, respectively, all of which occurred near the fractures and the stress distribution in Group D was the most uniform. The maximum displacements of internal fixations in Groups A, B, C, and D were 0.39, 0.45, 0.44, and 0.41 mm, respectively; the peak stresses on the fracture ends were 70.62, 98.48, 55.84, and 65.39 mPa, respectively, all of which were concentrated on the base of femoral neck and lateral cortex of the femoral shaft, and the stresses of Groups C and D were more evenly distributed than those of Groups A and B. The maximum displacements of fracture ends in Groups A, B, C, and D were 0.44, 0.52, 0.50, and 0.44 mm, respectively. CONCLUSIONS: The biomechanical stability of F-type CCS fixation is similar to that of 3 CCSs in an inverted triangular parallel configuration combined with medial buttress plate, with a better dispersion of stress. F-type CCS fixation may be a well option for the treatment of femoral neck fracture of Pauwels III.

The Effect of Bisphosphonates on Fracture Healing Time and Changes in Bone Mass Density: A Meta-Analysis.

Background: Osteoporosis is a common complication of acute fracture, which can lead to fracture delayed union or other complications and resulting in poor fracture healing. Bisphosphate is a common anti-osteoporosis drug, but its application in fracture patients is still controversial because of its inhibitory effect on bone resorption. Method: Studies were acquired from literature databases in accordance with established inclusion criteria. Standard mean difference (SMD) and 95% confidence intervals (Cls) were calculated to evaluate the effectiveness of the bisphosphonates treatment in fracture patients. Data analysis was conducted with the Review Manager 5.4.1 software. Results: A total of 16 studies involving 5022 patients obtained from selected databases were examined. As expected, bisphosphate had no significant effect on fracture healing time, but it could significantly increase BMD and prevent osteoporosis. Meanwhile, bisphosphate can inhibit both bone resorption and bone formation markers, resulting in low bone turnover state. Conclusion: This meta-analysis showed that bisphosphonate have no significant effect on fracture healing time but they do increase the changes in BMD and reduce bone synthesis and resorption markers. Early application of bisphosphonates after injury in the appropriate patient population should be considered.

Relationship between lipid metabolism and Hedgehog signaling pathway.

The Hedgehog (Hh) signaling pathway is highly conserved signaling pathway in cells. Steroids was found to play a vital role in Hh signaling pathway and aberrant Hh signaling was found to lead a series of disease correlate with abnormal lipid metabolism. This paper aimed to elucidate the relationship between lipid metabolism and Hedgehog signaling pathway.

Identification of genes and pathways associated with subchondral bone in osteoarthritis via bioinformatic analysis.

Osteoarthritis (OA) is a high prevalent musculoskeletal problem, which can cause severe pain, constitute a huge social and economic burden, and seriously damage the quality of life. This study was intended to identify genetic characteristics of subchondral bone in patients with OA and to elucidate the potential molecular mechanisms involved. Data of gene expression profiles (GSE51588), which contained 40 OA samples and 10 normal samples, was obtained from the Gene Expression Omnibus (GEO). The raw data were integrated to obtain differentially expressed genes (DEGs) and were further analyzed with bioinformatic analysis. The protein-protein interaction (PPI) networks were built and analyzed via Search Tool for the Retrieval of Interacting Genes (STRING). The significant modules and hub genes were identified via Cytoscape. Moreover, Gene Ontology (GO) and Kyoto Encyclopaedia of Genes and Genomes (KEGG) enrichment analysis were performed. Totally 235 DEGs were differentially expressed in the subchondral bone from OA patients compared with those of normal individuals, of which 78 were upregulated and 157 were downregulated. Eight hub genes were identified, including DEFA4, ARG1, LTF, RETN, PGLYRP1, OLFM4, ORM1, and BPI. The enrichment analyses of the DEGs and significant modules indicated that DEGs were mainly involved in inflammatory response, extracellular space, RAGE receptor binding, and amoebiasis pathway. The present study provides a novel and in-depth understanding of pathogenesis of the OA subchondral bone at molecular level. DEFA4, ARG1, LTF, RETN, PGLYRP1, OLFM4, ORM1, and BPI may be the new candidate targets for diagnosis and therapies on patients with OA in the future.

Is hip fracture surgery safe for patients on antiplatelet drugs and is it necessary to delay surgery? A systematic review and meta-analysis.

BACKGROUND: Hip fractures are common and account for a large proportion of orthopedic surgical admissions in elderly patients. However, determining the timing for surgery has been controversial for patients who develop hip fractures while on antiplatelet treatment. METHODS: Computerized databases for studies published from the inception date to January 2020, including the Cochrane Library, PubMed (Medline), EMBASE, Web of ScienceTM, ClinicalTrials, ClinicalKey, and Google Scholar, were searched using the keywords "Hip AND Fracture", "Antiplatelet", "Antithrombocyte", "Platelet aggregation inhibitors", "Aspirin", "Plavix", and "Clopidogrel". RESULTS: In total, 2328 initial articles were identified. Twenty-four studies with 5423 participants were ultimately included in our analysis. Early surgery was associated with an increased transfusion rate in the antiplatelet group compared to the non-antiplatelet group (OR = 1.21; 95% CI, 1.01 to 1.44; p = 0.03). Early surgery for hip fracture patients on antiplatelet therapy was associated with a greater decrease in hemoglobin compared to delayed surgery (WMD = 0.75; 95% CI, 0.50 to 1.00; p < 0.001). However, early surgery appeared to decrease the length of hospitalization (WMD = - 6.05; 95% CI, - 7.06 to - 5.04; p < 0.001) and mortality (OR = 0.43; 95% CI, 0.23 to 0.79; p = 0.006). CONCLUSION: It is unnecessary to delay surgery to restore platelet function when patients with hip fractures receive antiplatelet therapy. Furthermore, early surgery can significantly reduce mortality and hospital stay, which is conducive to patient recovery. Future randomized trials should determine whether the results are sustained over time.