Deep learning radiomics under multimodality explore association between muscle/fat and metastasis and survival in breast cancer patients.

Sarcopenia is correlated with poor clinical outcomes in breast cancer (BC) patients. However, there is no precise quantitative study on the correlation between body composition changes and BC metastasis and survival. The present study proposed a deep learning radiomics (DLR) approach to investigate the effects of muscle and fat on distant metastasis and death outcomes in BC patients. Image feature extraction was performed on 4th thoracic vertebra (T4) and 11th thoracic vertebra (T11) on computed tomography (CT) image levels by DLR, and image features were combined with clinical information to predict distant metastasis in BC patients. Clinical information combined with DLR significantly predicted distant metastasis in BC patients. In the test cohort, the area under the curve of model performance on clinical information combined with DLR was 0.960 (95% CI: 0.942-0.979, P < 0.001). The patients with distant metastases had a lower pectoral muscle index in T4 (PMI/T4) than in patients without metastases. PMI/T4 and visceral fat tissue area in T11 (VFA/T11) were independent prognostic factors for the overall survival in BC patients. The pectoralis muscle area in T4 (PMA/T4) and PMI/T4 is an independent prognostic factor for distant metastasis-free survival in BC patients. The current study further confirmed that muscle/fat of T4 and T11 levels have a significant effect on the distant metastasis of BC. Appending the network features of T4 and T11 to the model significantly enhances the prediction performance of distant metastasis of BC, providing a valuable biomarker for the early treatment of BC patients.

Intramedullary Nailing Versus Open Reduction and Plate Fixation for Lateral Malleolar Fractures: A Meta-Analysis.

The fixation for lateral malleolar fracture in ankle fractures is still controversial. The purpose of this meta-analysis is to compare clinical and radiological outcomes between intramedullary nail (IMN) and plate for lateral malleolar fractures in ankle fractures. The PubMed, EMBASE, and Cochrane Library were searched for randomized controlled trials (RCTs) from databases inception to June 2023. Data on outcomes were extracted and the methodological quality of the included studies were assessed. A meta-analysis was performed using RevMan 5.3 software when the data extracted from included studies could be synthesized. Seven RCTs were included. The methodological quality of the included studies was moderate to high. The meta-analysis results showed that the infection rate of the IMN group was significantly lower than that of the plate group (RR = 0.38; 95%CI 0.18-0.82; p = .01). There were no significant differences between the 2 groups in Olerud and Molander Ankle Score (OMAS), union rate, radiological outcomes, nerve injury rate, reoperation rate, loss of reduction, and total complication rate. Our present meta-analysis demonstrated that the IMN might be a better method for the fixation of lateral malleolar fracture in ankle fracture, as the infection rate was significantly lower than a plate.

Pectoralis muscle predicts distant metastases in breast cancer by deep learning radiomics.

BACKGROUND: Sarcopenia is associated with a poor prognosis in patients with breast cancer (BC). Currently, there are few quantitative assessments carried out between muscle biomarkers and distant metastasis using existing methods. PURPOSE: To assess the predictive value of the pectoralis muscle for BC distant metastasis, we developed a deep learning radiomics nomogram model (DLR-N) in this study. MATERIAL AND METHODS: A total of 493 patients with pathologically confirmed BC were registered. Image features were extracted from computed tomography (CT) images for each patient. Univariate and multivariate Cox regression analyses were performed to determine the independent prognostic factors for distant metastasis. The DLR-N was built based on independent prognostic factors and CT images to predict distant metastases. The model was assessed in terms of overall performance, discrimination, calibration, and clinical value. Finally, the predictive performance of the model was validated using the testing cohort. RESULTS: The developed DLR-N combined multiple radiomic features and clinicopathological factors and demonstrated excellent predictive performance. The C-index of the training cohort was 0.983 (95% confidence interval [CI] = 0.969-0.998) and the C-index of the testing cohort was 0.948 (95% CI = 0.917-0.979). Decision curve analysis (DCA) showed that patients could benefit more from incorporating multimodal radiomic features into clinicopathological models. CONCLUSIONS: DLR-N verified that there were biomarkers at the level of the fourth thoracic vertebra (T4) that affected distant metastasis. Multimodal prediction models based on deep learning could be a potential method to aid in the prediction of distant metastases in patients with BC.

Does Distal Clavicle Resection Decrease Pain or Improve Shoulder Function in Patients With Acromioclavicular Joint Arthritis and Rotator Cuff Tears? A Meta-analysis.

BACKGROUND: Acromioclavicular joint arthritis is a common, painful, and often missed diagnosis, and it often accompanies other shoulder conditions such as rotator cuff disease. Whether distal clavicle resection is important to perform in patients undergoing surgery for rotator cuff tears and concomitant acromioclavicular joint arthritis is controversial. QUESTIONS/PURPOSES: The purpose of this study was to perform a systematic review and meta-analysis of randomized controlled trials (RCTs) to evaluate the effect of distal clavicle resection on (1) outcome scores; (2) shoulder ROM, joint pain or tenderness, and joint instability; and (3) risk of reoperation among patients treated surgically for rotator cuff tears who had concomitant acromioclavicular joint arthritis. METHODS: We systematically searched the PubMed, EMBASE, and Cochrane databases to find RCTs that met our eligibility criteria, which, in summary, (1) compared rotator cuff repair plus distal clavicle resection with isolated rotator cuff repair for patients who sustained a full- or partial-thickness rotator cuff tear and concomitant acromioclavicular joint arthritis; and (2) the followup period was at least 2 years. Two reviewers screened the studies, extracted the data and evaluated the methodological quality, and performed data analysis. Statistical heterogeneity among studies was quantitatively evaluated with the I index. No heterogeneity was detected (I = 0%; p = 0.75) in terms of acromioclavicular joint pain or tenderness, Constant score, forward flexion, external rotation, and risk of reoperation, so fixed-effect models were used in these endpoints. Heterogeneity was moderate for the American Shoulder and Elbow Surgeons (ASES) score (I = 53%; p = 0.12) and low for the visual analog scale (VAS) score (I = 35%; p = 0.22), so random-effect models were used in these endpoints. Subgroup analysis was stratified by the symptom of acromioclavicular joint arthritis. Three RCTs with 208 patients were included. We evaluated the risk of bias using the Cochrane risk-of-bias tool; in aggregate, the three RCTs included showed low to intermediate risk, although not all parameters of the Cochrane tool could be assessed for all studies. RESULTS: There was no difference between the distal clavicle resection plus rotator cuff repair group and the isolated rotator cuff repair group in ASES score (mean difference =1.41; 95% confidence interval [CI], -3.37 to 6.18; p = 0.56) nor in terms of the VAS score and Constant score. Likewise, we found no difference in ROM of the shoulder (forward flexion, internal rotation, and external rotation) or acromioclavicular joint pain or tenderness between the groups (pooled results of acromioclavicular joint pain or tenderness: risk ratio [RR], 1.59; 95% CI, 0.67-3.78; p = 0.30). Acromioclavicular joint instability was only detected in the rotator cuff repair plus distal clavicle resection group. Finally, we found no difference in the proportion of patients undergoing repeat surgery between the study groups (pooled results of risk of reoperation for the rotator cuff repair plus distal clavicle resection and isolated rotator cuff repair: one of 52 versus two of 78; RR, 0.86; 95% CI, 0.11-6.48; p = 0.88). CONCLUSIONS: Distal clavicle resection in patients with rotator cuff tears did not result in better clinical outcome scores or shoulder ROM and was not associated with a lower risk of reoperation. Distal clavicle resection might cause acromioclavicular joint instability in patients with rotator cuff tears and concomitant asymptomatic acromioclavicular joint arthritis. Arthroscopic distal clavicle resection is not recommended in patients with rotator cuff tears and concomitant acromioclavicular joint arthritis. Additional well-designed RCTs with more participants, long-term followup, and data on patient-reported outcomes are needed. LEVEL OF EVIDENCE: Level I, therapeutic study.

Subcutaneous fat predicts bone metastasis in breast cancer: A novel multimodality-based deep learning model.

OBJECTIVES: This study explores a deep learning (DL) approach to predicting bone metastases in breast cancer (BC) patients using clinical information, such as the fat index, and features like Computed Tomography (CT) images. METHODS: CT imaging data and clinical information were collected from 431 BC patients who underwent radical surgical resection at Harbin Medical University Cancer Hospital. The area of muscle and adipose tissue was obtained from CT images at the level of the eleventh thoracic vertebra. The corresponding histograms of oriented gradients (HOG) and local binary pattern (LBP) features were extracted from the CT images, and the network features were derived from the LBP and HOG features as well as the CT images through deep learning (DL). The combination of network features with clinical information was utilized to predict bone metastases in BC patients using the Gradient Boosting Decision Tree (GBDT) algorithm. Regularized Cox regression models were employed to identify independent prognostic factors for bone metastasis. RESULTS: The combination of clinical information and network features extracted from LBP features, HOG features, and CT images using a convolutional neural network (CNN) yielded the best performance, achieving an AUC of 0.922 (95% confidence interval [CI]: 0.843-0.964, P< 0.01). Regularized Cox regression results indicated that the subcutaneous fat index was an independent prognostic factor for bone metastasis in breast cancer (BC). CONCLUSION: Subcutaneous fat index could predict bone metastasis in BC patients. Deep learning multimodal algorithm demonstrates superior performance in assessing bone metastases in BC patients.

[Retracted] Tanshinone­IIA attenuates the deleterious effects of oxidative stress in osteoporosis through the NF­κB signaling pathway.

Following the publication of this paper, it was drawn to the Editor's attention by a concerned reader that the images shown in Fig. 1E to represent the results from osteoclast differentation experiments were strikingly similar to data appearing in different form in another article written by different authors at different research institutes [Yang Y, Su Y, Wang D, Chen Y, Wu T, Li G, Sun X and Cui L: Tanshinol attenuates the deleterious effects of oxidative stress on osteoblastic differentiation via Wnt/FoxO3a signaling. Oxid Med Cell Longev 6: 351895, 2013]. Owing to the fact that the contentious data in the above article had already been published prior to its submission to Molecular Medicine Reports, the Editor has decided that this paper should be retracted from the Journal. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive a reply. The Editor apologizes to the readership for any inconvenience caused. [Molecular Medicine Reports 17: 6969­6976, 2018; DOI: 10.3892/mmr.2018.8741].

Plate versus screws fixation for the posterior malleolar fragment in trimalleolar ankle fractures.

BACKGROUND: The fixation methods of posterior malleolar fracture (PMF) in trimalleolar ankle fractures is still controversial. We aim to compare clinical and radiological outcomes between plate fixation and screws fixation for PMF in trimalleolar ankle fractures. METHODS: Literature search was performed through PubMed, EMBASE, Cochrane Library and CNKI database from databases inception to May 2022 to identify randomized controlled trial (RCT) and comparative clinical study in English or Chinese. A meta-analysis was performed using RevMan 5.1 software, and systematic review was performed when the data extracted from included studies could not be synthesized. RESULTS: Two RCTs and six cohort studies were included. The meta-analysis results showed that articular step-off or gap in plate fixation was superior to antero-posterior screws fixation (RR = 0.28; 95%CI: 0.11, 0.76; P = 0.01). there were no significant differences in American Orthopaedic Foot & Ankle Society scores (MD = -0.19; 95%CI: -2.43, 2.05; P = 0.87), arthritis (RR = 1.67; 95%CI: 0.61, 4.55; P = 0.32), infection and total complication (RR = 1.42; 95%CI: 0.89, 2.25; P = 0.14). CONCLUSION: Plate fixation might have better articular step-off or gap, compared with "A to P" screws fixation for the posterior malleolus in trimalleolar ankle fractures. Screw fixation could achieve shorter surgical time than plate fixation. However, no significant differences were found in AOFAS scores, arthritis, infection, sural nerve injury and total complication during the comparisons.

Biomechanical Study of Intramedullary Versus Extramedullary Implants for Four Types of Subtrochanteric Femoral Fracture.

OBJECTIVES: To compare the biomechanical performance of proximal femoral nail anti-rotation (PFNA), the "upside-down" less invasive plating system (LISS), and proximal femoral locking plate (PFLP) in fixing different fracture models of subtrochanteric fractures. METHODS: Thirty composite femurs were divided into three equal groups (PFNA, PFLP, and reverse LISS). The implant-femur constructs were tested under axial compression load (0-1400 N) from models I to IV, which represented the Seinsheimer type I subtrochanteric fracture, type IIIa subtrochanteric fracture with the posteromedial fragment reduced; type IIIa subtrochanteric fracture with the posteromedial fragment lost; and type IV subtrochanteric fracture, respectively. Axial stiffness was analyzed for each group. Each group was then divided into two subgroups, one of which underwent torsional and axial compression failure testing, while the other subgroup underwent axial compression fatigue testing. The torsional stiffness, failure load, and cycles to failure were analyzed. RESULTS: PFNA had the highest axial stiffness (F = 761.265, p < 0.0001) and failure load (F = 48.801, p < 0.0001) in model IV. The axial stiffness and failure load of the PFLP were significantly higher than those of the LISS (p < 0.0001, p = 0.001). However, no significant difference in axial stiffness was found between models I to III (model I: F = 2.439, p = 0.106; model II: F = 2.745, p = 0.082; model III: F = 0.852, p = 0.438) or torsional stiffness in model IV (F = 1.784, p = 0.187). In fatigue testing, PFNA did not suffer from construct failure after 90,000 cycles of axial compression. PFLP and LISS were damaged within 14,000 cycles, although LISS withstood more cycles than PFLP (t = 3.328, p = 0.01). CONCLUSION: The axial stiffness of the three implants was similar in models I to III. The biomechanical properties of PFNA were the best of the three implants in terms of axial stiffness, failure load, and fatigue testing cycles in model IV. The axial stiffness and failure load of the PFLP were better than those of the reverse LISS, but PFLP had fewer cycles in the fatigue tests than the reverse LISS.

Multiple cannulated screw fixation of femoral neck fractures with comminution in young- and middle-aged patients.

OBJECTIVE: To investigate the distribution and influence of comminution in femoral neck fracture (FNF) patients after cannulated screw fixation (CSF). METHODS: From January 2019 to June 2020, a total of 473 patients aged 23-65 years with FNF treated by CSF were included in the present study. Based on location of the cortical comminution, FNF patients were assigned to two groups: the comminution group (anterior comminution, posterior comminution, superior comminution, inferior comminution, multiple comminutions) or the without comminution group. The incidence of postoperative complications, quality of life and functional outcomes was recorded at 1-year follow-up. RESULTS: Comminution was more likely to appear in displaced FNF patients (86.8%) compared with non-displaced FNF patients (8.9%), and the rate of comminution was closely associated with Pauwels classification (3.2% vs 53.5% vs 83.9%, P < 0.05). The incidence of osteonecrosis of the femoral head (ONFH, 11.3% vs 2.9%, P < 0.05), nonunion (7.5% vs 1.7%, P < 0.05), femoral neck shortening (21.6% vs 13.4%, P < 0.05) and internal fixation failure (11.8% vs 2.9%, P < 0.05) was significantly higher in FNF patients with comminutions, especially with multiple comminutions, than those without. Furthermore, there was a significant difference in the Harris hip score (HHS, 85.6 ± 15.6 vs 91.3 ± 10.8, P < 0.05) and EuroQol five dimensions questionnaire (EQ-5D, 0.85 ± 0.17 vs 0.91 ± 0.18, P < 0.05) between FNF patients with comminution and those without. There was no significant difference in Visual analogue scale scores (VAS, 1.46 ± 2.49 vs 1.13 ± 1.80, P > 0.05) between two groups at 1 year post-surgery. CONCLUSION: Comminution is a risk factor for postoperative complications in young- and middle-aged patients with displaced and Pauwels type III FNF who undergo CSF. This can influence the recovery of hip function, thereby impacting quality of life. Further evaluation with a more comprehensive study design, larger sample and long-term follow-up is needed.

Romosozumab versus Teriparatide for the Treatment of Postmenopausal Osteoporosis: A Systematic Review and Meta-analysis through a Grade Analysis of Evidence.

OBJECTIVE: To provide a systematic review about the efficacy and safety of romosozumab and teriparatide for the treatment of postmenopausal osteoporosis. METHOD: Randomized controlled trials (RCTs) were searched from electronic databases, including PubMed (1996 to June 2019), Embase (1980 to June 2019), Cochrane Library (CENTRAL, June 2019), Web of Science (1998 to June 2019), and others. The primary outcomes included the following: the percentage change in bone mineral density of lumbar spine and total hip from baseline at month 6 and month 12 in each group. The secondary outcomes included the following: the percentage change in bone mineral density of femoral neck from baseline at month 6 and month 12 in each group and the incidence of adverse events at month 12 in each group. RESULTS: Four studies containing 1304 patients met our selection criteria. The result of our analysis indicated that romosozumab showed better effects in improving BMD of lumbar spine (month 6: MD = 3.54, 95% CI [3.13, 3.94], P<0.001; month 12: MD = 4.93, 95% CI [4.21, 5.64], P<0.001), total hip (month 6: MD = 2.27, 95% CI [0.62, 3.91], P = 0.007; month 12: MD = 3.17, 95% CI [2.68, 3.65], P<0.001), and femoral neck (month 6: MD = 2.30, 95% CI [0.51, 4.08], P = 0.01; month 12: MD = 3.04, 95% CI [2.29, 3.78], P<0.001). Also, the injection-site reaction was less (month 12: RR = 2.84, 95% CI [1.22, 6.59], P = 0.02), but there were no significant difference in the incidence of serious adverse events (month 12: RR = 0.78, 95% CI [0.46, 1.33], P = 0.37) and death (month 12: RR = 0.61, 95% CI [0.08, 4.62], P = 0.63). CONCLUSION: Based on the available studies, our current results demonstrate that romosozumab was better than teriparatide both in terms of efficacy and side effects.

MicroRNA-1 Modulates Chondrocyte Phenotype by Regulating FZD7 of Wnt/ ß-Catenin Signaling Pathway.

OBJECTIVE: Osteoarthritis (OA) is an incurable joint disease characterized by pronounced pain. MicroRNAs constitute epigenetic mechanisms that may affect OA progression by contributing to changes in chondrocyte phenotype. This study investigates for the first time whether there is a link between miRNA-1 (miR-1) and OA pathogenesis, and the molecular mechanisms involved. DESIGN: OA-associated gene expression, including MMP-13, ADAMTS5, and COL2A1 was compared in chondrocytes from non-OA and OA cartilage, and in SW1353 cells over- and underexpressing miR-1. Bioinformatics and luciferase reporter assay were conducted to confirm whether FZD7 was a target of miR-1. The effects of miR-1 on FZD7 expression and downstream Wnt/ß-catenin signalling were investigated. RESULTS: Non-OA and OA chondrocytes differed significantly in the expression of miR-1 and OA-associated genes. MiR-1 over- and underexpression in SW1353 cells, respectively, reduced and enhanced gene expression associated with cartilage catabolism. FZD7, which has an important role in the Wnt/ß-catenin signaling pathway, was shown to be a potential target of miR-1. MiR-1 binding to FZD7 increased the levels of phosphorylated (inactivated) ß-catenin, thereby preventing downstream ß-catenin signaling. CONCLUSIONS: Inhibition of Wnt/ß-catenin signaling by miR-1 in chondrocytes may attenuate the expression of genes that regulate the activity of catabolic enzymes. This finding may be useful for future investigations of molecular targets for OA treatment.

Intramedullary versus extramedullary fixation in the treatment of subtrochanteric femur fractures: A comprehensive systematic review and meta-analysis.

OBJECTIVE: This meta-analysis aimed to compare the clinical outcomes of intramedullary fixation with the extramedullary fixation in the surgical management of subtrochanteric fractures by analyzing relevant randomized controlled trials (RCTs) and retrospective cohort studies (RCSs). METHODS: The PubMed, Embase, Cochrane Library, Wanfang database, and Chinese National Knowledge Infrastructure (CNKI) were searched from their inception till June 29, 2020. Two reviewers extracted the data, including operation time, intraoperative blood loss, fluoroscopy time, length of stay, union time, nonunion rate, infection rate, implant failure rate, reoperation rate, Harris hip score, and mortality rate. The Cochrane risk-of-bias tool and the Newcastle-Ottawa quality assessment scale were used to evaluate the methodological quality of RCTs and RCSs, respectively. Statistical heterogeneity was quantitatively evaluated with the I2 statistic. RESULTS: There were no significant differences in operation time, intraoperative blood loss, average length of stay in hospital, infection rate, implant failure rate, Harris hip scores, and mortality rate. Intramedullary nail could achieve shorter union time (MD=-1.77, 95% CI -3.40~-0.14, p=0.03), lower nonunion rate (RR=0.36, 95%CI 0.14~0.97, p=0.04), and reoperation rate (RR=0.46, 95% CI 0.24~0.89, p=0.02) than extramedullary fixations. The subgroup analysis indicated that intramedullary nail was superior than extramedullary fixations in operation time, reoperation rate, and Harris hip scores in the ≥60-year subgroup. However, the intraoperative blood loss in intramedullary nail group was significantly higher than that of extramedullary fixation group in the <60-year subgroup. CONCLUSION: The results of this study have revealed that intramedullary fixation can confer shorter union time, lower nonunion, and reoperation rates compared with extramedullary fixations. Therefore, intramedullary fixation should be considered as the first selection for the treatment of patients with subtrochanteric fractures. LEVEL OF EVIDENCE: Level II, Therapeutic study.

A long non-coding RNA, HOTAIR, promotes cartilage degradation in osteoarthritis by inhibiting WIF-1 expression and activating Wnt pathway.

BACKGROUND: Long noncoding RNAs (lncRNAs) are recently found to be critical regulators of the epigenome. However, our knowledge of their role in osteoarthritis (OA) development is limited. This study investigates the mechanism by which HOTAIR, a key lncRNA with elevated expression in OA, affects OA disease progression. RESULTS: HOTAIR expression was greatly elevated in osteoarthritic compared to normal chondrocytes. Silencing and over-expression of HOTAIR in SW1353 cells respectively reduced and increased the expression of genes associated with cartilage degradation in OA. Investigation of molecular pathways revealed that HOTAIR acted directly on Wnt inhibitory factor 1 (WIF-1) by increasing histone H3K27 trimethylation in the WIF-1 promoter, leading to WIF-1 repression that favours activation of the Wnt/ß-catenin pathway. CONCLUSIONS: Activation of Wnt/ß-catenin signalling by HOTAIR through WIF-1 repression in osteoarthritic chondrocytes increases catabolic gene expression and promotes cartilage degradation. This is the first study to demonstrate a direct link between HOTAIR, WIF-1 and OA progression, which may be useful for future investigations into disease biomarkers or therapeutic targets.

Reference markers of bone turnover for prediction of fracture: a meta-analysis.

OBJECTIVE: To explore whether bone turnover biomarkers (BTMs), i.e., C-terminal telopeptide of type I collagen (CTX) and procollagen type I aminoterminal propeptide (PINP), are associated with fracture. METHODS: We searched electronic database including PubMed, Embase and Cochrane Library, and the reference lists of relevant articles published from inception to August 22, 2018. An updated meta-analysis was performed to assess the prediction value of CTX and PINP in fracture. RESULTS: Nine articles met our inclusion criteria and were included in the meta-analysis. The crude and adjusted effect size between PINP and fracture were extracted from two and five studies, respectively. PINP was not associated with fracture incidence without adjusting covariates (crude GR, 1.03; 95% CI, 0.91-1.17). After adjusting for potential confounders, PINP demonstrated a significant positive association with fracture (adjusted GR, 1.28; 95% CI, 1.15-1.42). In the subgroup analysis of studies after adjusting covariates, there were significant associations in women. Both the crude (1.16, 95%CI, 1.04-1.20) and adjusted GR (1.20, 95%CI, 1.05-1.37) shown positive relationships between CTX and fracture, which were extracted from four and six studies, separately. The sensitivity analysis confirmed the stability of the results. In the subgroup analysis of studies after adjusting covariates, there were significant associations in the subgroups of elderly, female, and hip fracture patients. CONCLUSIONS: Our results indicate a statistically significant but modest association between BTMs (s-PINP or s-CTX) and future fracture risk after adjusting for BMD and clinical risk factors. The causal relationship between the two clinical conditions requires future validation with more standardized studies. REGISTRATION NUMBER: CRD42018107879.

The effect of tail suspension and treadmill exercise on LRP6 expression, bone mass and biomechanical properties of hindlimb bones in SD rats.

Purpose: To investigate whether mechanical load regulates LRP6 expression and whether different intensities of treadmill exercise have different effects on LRP6 expression and the biomechanical properties of hindlimb bones in Sprague-Dawley (SD) rats. Methods: Fifty-six three-month-old virgin female SD rats were randomly divided into seven groups (n=8). Each group was subjected to tail suspension, free physiological activity or different intensities of treadmill exercise according to the experimental design for four or eight weeks. Rats were sacrificed after the intervention based on experimental design, and fresh femurs, tibias and fibulas were harvested for molecular biological analysis, biomechanical testing and micro-CT analysis. Results: LRP6 expression and the Wnt/ß-catenin pathway activity decreased, and bone mass and biomechanical properties decreased after loss of mechanical stimulation. For disuse osteoporosis, even physiological activity could improve LRP6 expression, Wnt/ß-catenin pathway activity, bone mass and biomechanical properties. Compared with physiological activity, treadmill exercise had better and faster effects on bone recovery. Compared with the Low intensity Exercise Group (LE group), the Medium intensity Exercise Group (ME group) and High intensity Exercise Group (HE group) had higher LRP6 expression, bone mass and biomechanical properties, while there were no significant difference between the ME group and HE group. Conclusions: Mechanical load appears to be a regulator of LRP6 expression, and it further affects the Wnt/ß-catenin pathway activity and bone mass. The LRP6 expression, bone mass and biomechanical properties gradually improve as treadmill exercise intensity increases, while there is no significant difference between the ME group and HE group.

Tanshinone­IIA attenuates the deleterious effects of oxidative stress in osteoporosis through the NF­κB signaling pathway.

Osteoclasts are responsible for bone resorption caused by bone microstructural damage and bone-related disorders. Evidence shows that tanshinone IIA (Tan­IIA), a traditional Chinese medicine, is used clinically as a drug for the treatment of cardiovascular and cerebrovascular diseases. However, the efficacy and mechanism underlying the effect of Tan­IIA on the viability of osteoclasts remain to be fully elucidated. The present study investigated the therapeutic effects of Tan­IIA on osteoblast differentiation and oxidative stress in vitro and in vivo. Cell viability was analyzed and oxidative stress was examined in the osteoblasts. Wnt1sw/sw mice were used to investigate the therapeutic effects of Tan­IIA on spontaneous tibia fractures and severe osteopenia. The bone strength, collagen and mineral were examined in the tibia. Osteoblast activity was also analyzed in the experimental mice. The Tan­IIA­induced differentiation of osteoclasts and the mechanism of action were investigated in osteocytes. The data showed that Tan­IIA treatment improved cell viability. The data also demonstrated that Tan­IIA decreased the levels of H2O2, accumulation of reactive oxygen species and apoptosis of osteoblasts. Tan­IIA inhibited the deleterious outcomes triggered by oxidative stress. In addition, Tan­IIA inhibited the activation of nuclear factor (NF)­κB and its target genes, tumor necrosis factor (TNF)­α, inducible nitric oxide synthase and cyclooxygenase 2, and increased the levels of TNF receptor­associated factor 1 and inhibitor of apoptosis protein­1/2 in the osteocytes. Furthermore, it was shown that Tan­IIA reduced the propensity to fractures and severe osteopenia in mice with osteoporosis. Tan­IIA also exhibited improved bone strength, mineral and collagen in the bone matrix of the experimental mice. It was found that the Tan­IIA­mediated benefits on osteoblast activity and function were through the NF­κB signaling pathway. Taken together, the data obtained in the present study suggested that Tan­IIA had protective effects against oxidative stress in osteoblastic differentiation in mice with osteoporosis by regulating the NF­κB signaling pathway.

Tormentic acid inhibits IL-1ß-induced chondrocyte apoptosis by activating the PI3K/Akt signaling pathway.

Interleukin-1ß (IL-1ß) accelerates degradation of the cartilage matrix and induces apoptosis of chondrocytes. Tormentic acid (TA) is a triterpene isolated from the stem bark of the Vochysia divergens plant, which has been demonstrated to exert in vitro inhibitory activity against hepatocyte apoptosis. However, the effects of TA on IL­1ß­induced apoptosis of human chondrocytes remain unclear. Therefore, the present study investigated the in vitro effects of TA on human osteoarthritic chondrocyte apoptosis cultivated in the presence of IL­1ß. Human chondrocytes were pretreated with or without various concentrations of TA and then co­incubated in the absence or presence of IL­1ß for 24 h. Cell viability was determined using the MTT assay, and cell apoptosis was detected using a Nucleosome ELISA kit. Caspase­3 activity was detected using a caspase­3 colorimetric assay kit. The levels of B­cell lymphoma 2 (Bcl­2)­associated X protein (Bax), Bcl­2, phosphorylated (p)­phosphoinositide 3­kinase (PI3K), PI3K, p­protein kinase B (Akt) and Akt were measured by western blotting. The results revealed that pretreatment with TA inhibited IL­1ß­induced cytotoxicity and apoptosis in chondrocytes. In addition, TA pretreatment increased B­cell lymphoma (Bcl)­2 expression, and decreased caspase­3 activity and Bax expressionin human chondrocytes. In addition, pretreatment with TA markedly increased the expression of p­PI3K and p­Akt in IL­1ß­induced chondrocytes. Collectively, these results indicate that TA inhibits IL­1ß­induced chondrocyte apoptosis by activating the PI3K/Akt signaling pathway. Therefore, TA may be considered a potential therapeutic target for the treatment of osteoarthritis.

LncRNA-H19 Modulates Wnt/ß-catenin Signaling by Targeting Dkk4 in Hindlimb Unloaded Rat.

OBJECTIVE: To investigate the biological functions of long noncoding RNA-H19 (H19) in the pathogenesis of disuse osteoporosis (DOP). METHODS: Fifty-four male Sprague Dawley (SD) rats were randomly divided into three groups: baseline control (BC, 6), age-matched control (AC, 24), and hindlimb unloading (HLU, 24). The rats in the BC group were sacrificed at the beginning of the experiment, while the AC and HLU rats were sacrificed at different times (7, 14, 21 and 28 days after HLU). The DOP model was verified by micro-CT scan, and quantitative real-time polymerase chain reaction (qRT-PCR) was used to quantify the expression of osteogenic genes (OPG, RunX2 and OPG). Gene sequencing and bioinformatic analysis were performed to find H19 target genes and the associated signaling pathway, which were first verified on tissue samples. Further verification was performed by knocking down the H19 and related gene in rat osteoblast cell line (UMR106 cell). Then, the changes of associated signaling pathway and osteogenic function were examined to confirm the prediction of the bioinformatic analysis. RESULTS: Micro-CT scans and quantitative real-time polymerase chain reaction (qRT-PCR) tests showed progressively deteriorated trabecular bone and decreased level of osteogenic genes in the metaphysis of distal femur during HLU, indicating the successful establishment of a DOP model. According to RNA sequencing, 1351 mRNA and 464 lncRNA were abnormally expressed in response to mechanical unloading, in which the H19 decreased 2.86 fold in HLU rats. There were 1426 mRNA predicted to be the target genes of H19, and KEGG pathway analysis suggested that Wnt signaling pathway (Wnt signaling) was the top pathway responsible for these target genes. In the Wnt-associated genes targeted by H19, 11 were differentially expressed between HLU and AC rats, among which Dkk4 increased 2.44 fold in HLU rats when compared to normal controls. These results of sequencing and bioinformatic analysis were confirmed by the low expression of H19, overexpression of Dkk4 and inhibited Wnt signaling observed in DOP rats. Subsequent in vitro cell assay further demonstrated that knockdown of H19 led to upregulation of Dkk4, and inhibition of Wnt signaling and osteogenic function in UMR106 cell. These effects can be greatly reversed after application of knocking down Dkk4. CONCLUSION: Our findings demonstrated that low expression of H19, induced by mechanical unloading, leads to development of DOP through inhibition of Wnt signaling by promoting Dkk4 expression.

Biomechanical effect of interspinous process distraction height after lumbar fixation surgery: An in vitro model.

Pedicle screw fixation may induce abnormal activity at adjacent segment and accelerate the degeneration of lumbar vertebrae. Dynamic stabilizers could provide an intermediate solution between conservative treatment and fusion surgery. Lumbar vertebral segment cephalad to instrumented fixation was the most common localization of adjacent segment degeneration. The aim of this study is to explore the use of interspinous process devices in the lumbar vertebral segment cephalad to fixation segment in changing the mechanical distribution and limiting abnormal activity of the spine. Eight specimens were tested in the following groups: intact group, instability group (bilateral facetectomy at L3-L4), fixation group (bilateral facetectomy and pedicle screw fixation at L3-L4), and hybrid fixation group (fixation at L3-L4 and simulating interspinous device implantation of 6, 8, 10, 12, 14, 16, and 18 mm at L2-L3). Range of motion, motion of vertebral body, and strain distribution change were recorded. The range of motion in extension with 16- and 18-mm hybrid constructs was significantly lower than intact, instability, and fixation groups. In flexion and lateral bending, the strain values of L4 inferior articular process with 18-mm hybrid construct have a significant difference compared with other groups. In axial rotation, under the condition of a contralateral state, the strain values of L2 superior articular process with 18-mm hybrid construct have a significant difference compared with intact and fixation groups. The strain value of the L4 inferior articular process had negative correlation with height distraction in three dimensions, except extension. A negative correlation between the strain value of the L2 superior articular process and distraction height was found in contralateral bending and contralateral axial rotation. Interspinous process devices above the fixation segment can change the mechanical distribution of the spine and limit activity in some of the segments of the spine, which may delay the degeneration of the adjacent segment.

Biomechanical Evaluation of Four Methods for Internal Fixation of Comminuted Subtrochanteric Fractures.

Subtrochanteric fractures are common and result in significant morbidity and mortality. Various kinds of implants have been used to fix it. The aim of this study was to compare the biomechanical performance of PFN, DHS, DCS, and the PFLP in the treatment of subtrochanteric comminuted fractures.A total of 32 antiseptic human femurs from 16 donors were randomly allocated to 4 groups for fixation with PFN, DHS, DCS, and PFLP. A 2-cm cylindrical bone fragment was removed 1 cm below the lesser trochanter to simulate OTA/AO 32-C3.2 post instrumentation fracture. All specimens in single-leg stance situation were preloaded 5 times at 100 N in the axial direction to eliminate the time effect of relaxation and settling, followed by cyclic testing at a rate of 1 Hz with stepwise increasing load. Keeping the valley load at a constant level of 100 N during the entire cyclic test, the peak load, starting at 200 N, was increased by 100 N at 300-cycle steps until a maximum of 1500 cycles or until failure of the bone-implant construct occurred. Each specimen was kept unloaded under 100 N compression for 30 minutes between the 300-cycle steps.Femoral head displacement after 1500 cycles was 1.09 mm ±â€Š0.13 for PFN, 1.78 mm ±â€Š0.25 for DHS, 2.63 mm ±â€Š0.46 for DCS, and 2.26 mm ±â€Š0.16 for PFLP, with significant difference between any 2 implants (P < 0.01). The required load to reach 1-mm femoral head displacement was 563.04 N ±â€Š158.34 for PFN, 485.73 N ±â€Š147.27 for DHS, 258.44 N ±â€Š97.23 for DCS, and 332.68 N ±â€Š100.34 for PFLP. Significant differences were detected between any 2 implants (P < 0.001), except between DCS and PFLP and between DHS and PFN. The number of cycles until 1-mm femoral head displacement was 1458 ±â€Š277 for PFN, 908 ±â€Š184 for DHS, 369 ±â€Š116 for DCS, and 603 ±â€Š162 for PFLP. Significant differences were detected between any 2 implants (P < 0.01), except between DCS and PFLP.From biomechanical point of view, comminuted subtrochanteric fractures OTA/AO 32-C3.2 revealed in the current test setup highest fixation strength with PFN, followed by DHS, PFLP, and DCS.