Cinnamaldehyde Alleviates Bone Loss by Targeting Oxidative Stress and Mitochondrial Damage via the Nrf2/HO-1 Pathway in BMSCs and Ovariectomized Mice.

Osteoporosis (OP) is typically brought on by disruption of bone homeostasis. Excessive oxidative stress and mitochondrial dysfunction are believed to be the primary mechanisms underlying this disorder. Therefore, in order to restore bone homeostasis effectively, targeted treatment of oxidative stress and mitochondrial dysfunction is necessary. Cinnamaldehyde (CIN), a small molecule that acts as an agonist for the nuclear factor erythroid 2-related factor (Nrf2), has been found to possess antiapoptotic, anti-inflammatory, and antioxidant properties. We found that CIN, while rescuing apoptosis, can also reduce the accumulation of reactive oxygen species (ROS) to improve mitochondrial dysfunction and thus restore the osteogenic differentiation potential of BMSCs disrupted by hydrogen peroxide (H2O2) exposure. The role of CIN was preliminarily considered to be a consequence of Nrf2/HO-1 axis activation. The ovariectomized mice model further demonstrated that CIN treatment ameliorated oxidative stress in vivo, partially reversing OVX-induced bone loss. This improvement was seen in the trabecular microarchitecture and bone biochemical indices. However, when ML385 was concurrently injected with CIN, the positive effects of CIN were largely blocked. In conclusion, this study sheds light on the intrinsic mechanisms by which CIN regulates BMSCs and highlights the potential therapeutic applications of these findings in the treatment of osteoporosis.

A Novel Anti-Osteoporosis Mechanism of VK2: Interfering with Ferroptosis via AMPK/SIRT1 Pathway in Type 2 Diabetic Osteoporosis.

Type 2 diabetic osteoporosis (T2DOP) is a chronic bone metabolic disease. Compared with traditional menopausal osteoporosis, the long-term high glucose (HG) microenvironment increases patients' risk of fracture and osteonecrosis. We were accumulating evidence that implicated ferroptosis as a pivotal mechanism of glucolipotoxicity-mediated death of osteocytes and osteoblast, a novel form of programmed cell death resulting from uncontrolled lipid peroxidation depending on iron. Vitamin K2 (VK2), a fat-soluble vitamin, is clinically applied to prevent osteoporosis and improve coagulation. This study aimed to clarify the role and mechanism of VK2 in HG-mediated ferroptosis. We established the mouse T2DOP model by intraperitoneal injection of streptozotocin solution and a high-fat and high-sugar diet. We also cultured bone marrow mesenchymal stem cells (BMSCs) in HG to simulate the diabetic environment in vitro. Based on our data, VK2 inhibited HG-mediated bone loss and ferroptosis, the latter manifested by decreased levels of mitochondrial reactive oxygen species, lipid peroxidation, and malondialdehyde and increased glutathione in vitro. In addition, VK2 treatment was capable of restoring bone mass and strengthening the expression of SIRT1, GPX4, and osteogenic markers in the distal femurs. As for further mechanism exploration, we found that VK2 could activate AMPK/SIRT1 signaling, and knockdown of SIRT1 by siRNA prevented the VK2-mediated positive effect in HG-cultured BMSCs. Summarily, VK2 could ameliorate T2DOP through the activation of the AMPK/SIRT1 signaling pathway to inhibit ferroptosis.

Application of interpretable machine learning algorithms to predict distant metastasis in osteosarcoma.

BACKGROUND: Osteosarcoma is well-established as the most common bone cancer in children and adolescents. Patients with localized disease have different prognoses and management than those with metastasis at the time of diagnosis. The purpose of this study was to explore potential risk factors for metastatic disease. METHODS: The Surveillance, Epidemiology, and End Results (SEER) Program database was used to identify patients diagnosed with osteosarcoma between 2004 and 2015. We developed prediction models for distant metastasis using six machine learning (ML) techniques, including logistic regression (LR), support vector machine (SVM), Gaussian Naive Bayes (GaussianNB), Extreme Gradient Boosting (XGBoost), random forest (RF), and k-nearest neighbor algorithm (kNN). The adaptive synthetic (ADASYN) technique was used to deal with imbalanced data. The Shapley Additive Explanation (SHAP) analysis generated visualized explanations for each patient. Finally, the average precision (AP), sensitivity, specificity, accuracy, F1 score, precision-recall curves, calibration plots, and decision curve analysis (DCA) were conducted to evaluate the models' effectiveness. RESULTS: The six machine learning algorithms achieved AP of 0.661-0.781 for predicting distant metastasis. The RF model yielded the best performance with an accuracy of 71.8 percent and an AP of 0.781 and was highly dependent on tumor size, primary surgery, and age. SHAP analysis provided model-independent interpretation, highlighting significant clinical factors associated with the risk of metastasis in osteosarcoma patients. CONCLUSIONS: An accurate machine learning-based prediction model was established for metastasis in osteosarcoma patients to help clinicians during clinical decision-making.

Application of machine learning model to predict lacunar cerebral infarction in elderly patients with femoral neck fracture before surgery.

BACKGROUND: Femoral neck fracture and lacunar cerebral infarction (LCI) are the most common diseases in the elderly. When LCI patients undergo a series of traumas such as surgery, their postoperative recovery results are often poor. Moreover, few studies have explored the relationship between LCI and femoral neck fracture in the elderly. Therefore, this study will develop a ML (machine learning)-based model to predict LCI before surgery in elderly patients with a femoral neck fracture. METHODS: Professional medical staff retrospectively collected the data of 161 patients with unilateral femoral neck fracture who underwent surgery in the Second Affiliated Hospital of Wenzhou Medical University database from January 1, 2015, to January 1, 2020. Patients were divided into two groups based on LCI (diagnosis based on cranial CT image): the LCI group and the non-LCI group. Preoperative clinical characteristics and preoperative laboratory data were collected for all patients. Features were selected by univariate and multivariate logistic regression analysis, with age, white blood cell (WBC), prealbumin, aspartate aminotransferase (AST), total protein, globulin, serum creatinine (Scr), blood urea nitrogen (Bun)/Scr, lactate dehydrogenase (LDH), serum sodium and fibrinogen as the features of the ML model. Five machine learning algorithms, Logistic regression (LR), Gradient Boosting Machine (GBM), Extreme Gradient Boosting (XGBoost), Random Forest (RF), and Decision tree (DT), were used in combination with preoperative clinical characteristics and laboratory data to establish a predictive model of LCI in patients with a femoral neck fracture. Furthermore, indices like the area under the receiver operating characteristic (AUROC), sensitivity, specificity, and accuracy were calculated to test the models' performance. RESULTS: The AUROC of 5 ML models ranged from 0.76 to 0.95. It turned out that the RF model demonstrated the highest performance in predicting LCI for femoral neck fracture patients before surgery, whose AUROC was 0.95, sensitivity 1.00, specificity 0.81, and accuracy 0.90 in validation sets. Furthermore, the top 4 high-ranking variables in the RF model were prealbumin, fibrinogen, globulin and Scr, in descending order of importance. CONCLUSION: In this study, 5 ML models were developed and validated for patients with femoral neck fracture to predict preoperative LCI. RF model provides an excellent predictive value with an AUROC of 0.95. Clinicians can better conduct multidisciplinary perioperative management for patients with femoral neck fractures through this model and accelerate the postoperative recovery of patients.

CORM-3 Attenuates Oxidative Stress-Induced Bone Loss via the Nrf2/HO-1 Pathway.

Bone metabolism occurs in the entire life of an individual and is required for maintaining skeletal homeostasis. The imbalance between osteogenesis and osteoclastogenesis eventually leads to osteoporosis. Oxidative stress is considered a major cause of bone homeostasis disorder, and relieving excessive oxidative stress in bone mesenchymal stem cells (BMSCs) is a potential treatment strategy for osteoporosis. Carbon monoxide releasing molecule-3 (CORM-3), the classical donor of carbon monoxide (CO), possesses antioxidation, antiapoptosis, and anti-inflammatory properties. In our study, we found that CORM-3 could reduce reactive oxygen species (ROS) accumulation and prevent mitochondrial dysfunction thereby restoring the osteogenic potential of the BMSCs disrupted by hydrogen peroxide (H2O2) exposure. The action of CORM-3 was preliminarily considered the consequence of Nrf2/HO-1 axis activation. In addition, CORM-3 inhibited osteoclast formation in mouse primary bone marrow monocytes (BMMs) by inhibiting H2O2-induced polarization of M1 macrophages and endowing macrophages with M2 polarizating ability. Rat models further demonstrated that CORM-3 treatment could restore bone mass and enhance the expression of Nrf2 and osteogenic markers in the distal femurs. In summary, CORM-3 is a potential therapeutic agent for the treatment of osteoporosis.

Development of a nomogram to predict surgical site infection after closed comminuted calcaneal fracture.

BACKGROUND: Compared with open comminuted calcaneal fractures, less emphasis is placed on postoperative surgical site infection (SSI) of closed comminuted calcaneal fractures. This study aimed to identify the risk factors associated with SSI and build a nomogram model to visualize the risk factors for postoperative SSI. METHODS: We retrospectively collected patients with closed comminuted calcaneal fractures from the Second Affiliated Hospital of Wenzhou Medical University database from 2017 to 2020. Risk factors were identified by logistics regression analysis, and the predictive value of risk factors was evaluated by ROC (receiver operating characteristic curve). Besides, the final risk factors were incorporated into R4.1.2 software to establish a visual nomogram prediction model. RESULTS: The high-fall injury, operative time, prealbumin, aspartate aminotransferase (AST), and cystatin-C were independent predictors of SSI in calcaneal fracture patients, with OR values of 5.565 (95%CI 2.220-13.951), 1.044 (95%CI 1.023-1.064), 0.988 (95%CI 0.980-0.995), 1.035 (95%CI 1.004-1.067) and 0.010 (95%CI 0.001-0.185) (Ps < 0.05). Furthermore, ROC curve analysis showed that the AUC values of high-fall injury, operation time, prealbumin, AST, cystatin-C, and their composite indicator for predicting SSI were 0.680 (95%CI 0.593-0.766), 0.756 (95%CI 0.672-939), 0.331 (95%CI 0.243-0.419), 0.605 (95%CI 0.512-0.698), 0.319 (95%CI 0.226-0.413) and 0.860 (95%CI 0.794-0.926), respectively (Ps < 0.05). Moreover, the accuracy of the nomogram to predict SSI risk was 0.860. CONCLUSIONS: Our study findings suggest that clinicians should pay more attention to the preoperative prealbumin, AST, cystatin C, high-fall injury, and operative time for patients with closed comminuting calcaneal fractures to avoid the occurrence of postoperative SSI. Furthermore, our established nomogram to assess the risk of SSI in calcaneal fracture patients yielded good accuracy and can assist clinicians in taking appropriate measures to prevent SSI.

Risk Factors for Pulmonary Embolism in ICU Patients: A Retrospective Cohort Study from the MIMIC-III Database.

Pulmonary embolism (PE) is a common and potentially lethal form of venous thromboembolic disease in ICU patients. A limited number of risk factors have been associated with PE in ICU patients. In this study, we aimed to screen the independent risk factors of PE in ICU patients that can be used to evaluate the patient's condition and provide targeted treatment. We performed a retrospective cohort study using a freely accessible critical care database Medical Information Mart for Intensive Care (MIMIC)-III. The ICU patients were divided into two groups based on the incidence of PE. Finally, 9871 ICU patients were included, among which 204 patients (2.1%) had pulmonary embolism. During the multivariate logistic regression analysis, sepsis, hospital_LOS (the length of stay in hospital), type of admission, tumor, APTT (activated partial thromboplastin time) and platelet were independent risk factors for patients for PE in ICU, with OR values of 1.471 (95%CI 1.001-2.162), 1.001 (95%CI 1.001-1.001), 3.745 (95%CI 2.187-6.414), 1.709 (95%CI 1.247-2.341), 1.014 (95%CI 1.010-1.017) and 1.002 (95%CI 1.001-1.003) (Ps < 0.05). ROC curve analysis showed that the composite indicator had a higher predictive value for ICU patients with PE, with a ROC area under the curve (AUC) of 0.743 (95%CI 0.710 -0.776, p < 0.001). Finally, sepsis, tumor, platelet count, length of stay in the hospital, emergency admission and APTT were independent predictors of PE in ICU patients.

The efficacy of Schroth exercises combined with the Chêneau brace for the treatment of adolescent idiopathic scoliosis: a retrospective controlled study.

PURPOSE: We aimed to determine the global effects of the Chêneau brace combined with Schroth exercises on adolescent idiopathic scoliosis (AIS). METHODS: We analyzed 192 patients with AIS who underwent the Chêneau brace treatment alone or combined with Schroth best practice (SBP) from June 2013 to October 2019. There were 138 patients in the Brace group and 54 patients in the Brace + SBP group. Radiographs were obtained at various treatment durations. Answers to the health-related quality of life (HRQoL) questionnaire were recorded before the intervention and at the time of treatment wean. RESULTS: The Cobb angle (-3.55°; p < 0.001) and C7-CSVL (-3.03 mm; p < 0.001) significantly decreased in the Brace + SBP group. Thoracic kyphosis (TK) decreased in both the Brace + SBP group (-1.85°; p = 0.0152) and the Brace group (-5.06; p < 0.001). Changes before and after treatment of TK were significantly different between groups (p < 0.001). The 22-item Scoliosis Research Society function score, self-image, mental health, and EuroQol 5-Dimension scores were significantly higher in the Brace + SBP group. The satisfaction score was higher in the Brace + SBP group (3.77 ± 0.63 vs. 3.13 ± 0.79; p < 0.001). CONCLUSIONS: Compared to bracing alone, the Schroth exercises plus bracing had a better effect on coronal balance. Schroth exercises improve flatback deformity caused by bracing and positively influence the HRQoL in AIS patients who received the Chêneau brace treatment.Implications for RehabilitationBracing and physiotherapy are common treatments for adolescent idiopathic scoliosis (AIS).The Chêneau brace treatment causes flatback deformity and muscle stiffness in AIS patients.The Schroth method helps patients increase muscle strength, halt curve progression, increase vital capacity, and maintain improved posture.The Schroth exercises could improve flatback deformity caused by bracing and positively influence the health-related quality of life in AIS patients who received the Chêneau brace treatment.

Apelin-13 induces mitophagy in bone marrow mesenchymal stem cells to suppress intracellular oxidative stress and ameliorate osteoporosis by activation of AMPK signaling pathway.

Osteoporosis is characterized by impaired bone metabolism. Current estimates show that it affects millions of people worldwide and causes a serious socioeconomic burden. Mitophagy plays key roles in bone marrow mesenchymal stem cells (BMSCs) osteoblastic differentiation, mineralization, and survival. Apelin is an endogenous adipokine that participates in bone homeostasis. This study was performed to determine the role of Apelin in the osteoporosis process and whether it affects mitophagy, survival, and osteogenic capacity of BMSCs in in vitro and in vivo models of osteoporosis. Our results demonstrated that Apelin was down-regulated in ovariectomized-induced osteoporosis rats and Apelin-13 treatment activated mitophagy in BMSCs, ameliorating oxidative stress and thereby reviving osteogenic function via AMPK-α phosphorylation. Besides, Apelin-13 administration restored bone mass and microstructure as well as reinstated mitophagy, enhanced osteogenic function in OVX rats. Collectively, our findings reveal the intrinsic mechanisms underlying Apelin-13 regulation in BMSCs and its potential therapeutic values in the treatment of osteoporosis.

Proanthocyanidins-Mediated Nrf2 Activation Ameliorates Glucocorticoid-Induced Oxidative Stress and Mitochondrial Dysfunction in Osteoblasts.

The widespread use of therapeutic glucocorticoids has increased the frequency of glucocorticoid-induced osteoporosis (GIOP). One of the potential pathological processes of GIOP is an increased level of oxidative stress and mitochondrial dysfunction, which eventually leads to osteoblast apoptosis. Proanthocyanidins (PAC) are plant-derived antioxidants that have therapeutic potential against GIOP. In our study, a low dose of PAC was nontoxic to healthy osteoblasts and restored osteogenic function in dexamethasone- (Dex-) treated osteoblasts by suppressing oxidative stress, mitochondrial dysfunction, and apoptosis. Mechanistically, PAC neutralized Dex-induced damage in the osteoblasts by activating the Nrf2 pathway, since silencing Nrf2 partly eliminated the protective effects of PAC. Furthermore, PAC injection restored bone mass and promoted the expression of Nrf2 in the distal femur of Dex-treated osteoporotic rats. In summary, PAC protect osteoblasts against Dex-induced oxidative stress and mitochondrial dysfunction via the Nrf2 pathway activation and may be a promising drug for treating GIOP.

Vitamin K2 Can Rescue the Dexamethasone-Induced Downregulation of Osteoblast Autophagy and Mitophagy Thereby Restoring Osteoblast Function In Vitro and In Vivo.

Chronic long-term glucocorticoids (GC) use is associated with glucocorticoid-induced osteoporosis (GIOP) by inhibiting the survival and impairing the functions of osteoblasts. Autophagy and mitophagy play key roles in osteoblast differentiation, mineralization and survival, and mounting evidence have implicated osteoblast autophagy and mitophagy as a novel mechanism in the pathogenesis of GIOP. Vitamin K2 (VK2) is an essential nutrient supplement that have been shown to exert protective effects against osteoporotic bone loss including GIOP. In this study, we showed that the glucocorticoid dexamethasone (Dex) deregulated osteoblast autophagy and mitophagy by downregulating the expression of autophagic and mitophagic markers LC3-II, PINK1, Parkin. This consequently led to inhibition of osteoblast differentiation and mineralization function in vitro. Interestingly, co-treatment with VK2 significantly attenuated the Dex-induced downregulation of LC3-II, PINK1, Parkin, thereby restoring autophagic and mitophagic processes and normal osteoblastic activity. In addition, using an established rat model of GIOP, we showed that VK2 administration can protect rats against the deleterious effects of Dex on bone by reinstating autophagic and mitophagic activities in bone tissues. Collectively, our results provide new insights into the role of osteoblast autophagy and mitophagy in GIOP. Additionally, the use of VK2 supplementation to augment osteoblast autophagy/mitophagy may significantly improve clinical outcomes of GIOP patients.

Imperatorin promotes osteogenesis and suppresses osteoclast by activating AKT/GSK3 ß/ß-catenin pathways.

Osteoporosis is caused by disturbance in the dynamic balance of bone remodelling, a physiological process, vital for maintenance of healthy bone tissue in adult humans. In this process, a new bone is formed by osteoblasts and the pre-existing bone matrix is resorbed by osteoclasts. Imperatorin, a widely available and inexpensive plant extract with antioxidative and apoptotic effects, is reported to treat osteoporosis. However, the underlying mechanism and specific effects on bone metabolism have not been elucidated. In this study, we used rat bone marrow-derived mesenchymal stem cells and found that imperatorin can activate RUNX2, COL1A1 and osteocalcin by promoting the Ser9 phosphorylation of GSK3ß and entry of ß-catenin into the nucleus. Imperatorin also enhanced the production of phospho-AKT (Ser473), an upstream factor that promotes the Ser9 phosphorylation of GSK3ß. We used ipatasertib, a pan-AKT inhibitor, to inhibit the osteogenic effect of imperatorin, and found that imperatorin promotes osteogenesis via AKT/GSK3ß/ß-catenin pathway. Next, we used rat bone marrow-derived monocytes, to check whether imperatorin inhibits osteoclast differentiation via AKT/GSK3ß/ß-catenin pathway. Further, we removed the bilateral ovaries of rats to establish an osteoporotic model. Intragastric administration of imperatorin promoted osteogenesis and inhibited osteoclast in vivo. Our experiments showed that imperatorin is a potential drug for osteoporosis treatment.

A nomogram to predict prognosis in Ewing sarcoma of bone.

OBJECTIVE: This study was designed to develop a nomogram for assessing the survival of patients with Ewing sarcoma (ES). METHODS: Data from patients diagnosed with ES between 2004 and 2013 were collected from the Surveillance, Epidemiology, and End Results (SEER) database. Based on patient registration, the primary cohort was divided into a training set (n = 479, data from 17 cancer registries) and a validation set (n = 137, data from 1 cancer registry). Then, the prognostic effects of variables were analyzed using Kaplan-Meier method and Cox proportional hazard model. Moreover, nomograms were established for estimating 3- and 5-year overall survival (OS) and cancer-special survival (CSS) based on Cox regression model. Last, nomogram was validated by training set and validation set. RESULTS: According to the multivariate analysis of training set, nomogram which combined age, race, stage, tumor site, tumor size and chemotherapy was identified. The internal bootstrap resampling approach suggested the nomogram had sufficient discriminatory power with the C-index of OS: 0.754 (95% CI, 0.705-0.802) and CSS: 0.759 (95% CI, 0.700-0.800). The calibration plots also demonstrated good consistence between the prediction and the observation. CONCLUSION: Our nomogram is a reliable and powerful tool for distinguishing and predicting the survival of ES patients, thus helping to better select medical examinations and optimize treatment options in collaboration with medical oncologists and surgeons.

Combined treatment with vitamin K2 and PTH enhanced bone formation in ovariectomized rats and increased differentiation of osteoblast in vitro.

Osteoporosis is accompanied by insufficient osteogenic capacity. Several lines of evidence suggested that solutions to enhance osteoblastogenesis were important strategies for osteoporotic bone defect repair. This study investigated the effect of combined treatment with vitamin K2 and PTH on bone formation in calvarial bone defect in osteoporotic rats and its influence on osteoblast in vitro. Bilateral ovariectomy was used in SPF Sprague Dawley rats to generate an osteoporosis model. Subsequently, a calvarial defect model was established and all osteoporotic rats were randomly assigned to the following groups: control, VK (vitamin K2, 30 mg/kg everyday), PTH (recombinant human PTH (1-34), 60 µg/kg, three times a week) or VK + PTH (vitamin K2, 30 mg/kg everyday plus PTH, 60 µg/kg three times a week) for 8 weeks. In vitro, bone marrow-derived stem cells (BMSCs) were cultured and treated with vitamin K2, PTH or vitamin K2+PTH. ALP staining and western blot were performed to observe the influence of combined treatment on BMSCs. Bone formation within calvarial defect were assessed by serum γ-carboxylated osteocalcin (Gla-OC), micro-CT, histological and immunofluorescent labeling. In this study, combined treatment of PTH and vitamin K2 showed positive effects on preventing bone loss in femurs in OVX rats. Combined treatment increased serum Gla-OC and promoted bone formation in osteoporotic calvarial bone defects. Immunohistochemistry showed that OCN and RUNX2 were more highly expressed in the VK + PTH group than in the control groups. In vitro studies results suggested that combined treatment with PTH and vitamin K2 increased expression of ALP, BMP2 and RUNX2 in BMSCs. Our data suggested that the combination of vitamin K2 and PTH increased differentiation of osteoblast and had a synergistic effect on bone formation in osteoporotic calvarial bone defect.

Combined treatment with Cinnamaldehyde and ß-TCP had an additive effect on bone formation and angiogenesis in critical size calvarial defect in ovariectomized rats.

Accumulating evidence suggests that improvements in osteogenesis and angiogenesis play an important role in repairing osteoporotic bone defects. Cinnamomum cassia (C. cassia), a traditional Chinese medicinal herb, is reported to show anabolic effects on osteoblasts. However, whether C. cassia could actually repair bone defects in osteoporotic conditions remains unknown. The purpose of this study was to evaluate the effect of combined treatment with Cinnamaldehyde (main oil isolated from the C. cassia) and ß-tricalcium phosphate (ß-TCP) on bone formation and angiogenesis in critical size calvarial defects in ovariectomized (OVX) rats. Using a previously established OVX model, 5 mm critical size calvarial defect was established in OVX rats. All OVX rats were then randomly divided into OVX group (OVX rats + empty defect), TCP group (OVX rats + ß-TCP), and CTCP group (Cinnamaldehyde 75 mg/kg/day for 12 weeks + ß-TCP). Twelve weeks after treatment, according to Micro-CT and HE staining, combination of Cinnamaldehyde and ß-TCP had an additive effect on bone regeneration compared with other groups (p < 0.05). Based on dynamic fluorochrome-labelling analysis, Cinnamaldehyde+ß-TCP continuously promoted new bone mineralization compared with other groups at each time point (p < 0.05). Microfil perfusion suggested that CTCP group showed more neovascularization compared with other groups (p < 0.05). Immunohistochemical assay supported the findings that Cinnamaldehyde+ß-TCP enhanced expression of OCN, VEGF and CD31. The present study demonstrated that combined treatment with Cinnamaldehyde and ß-TCP promoted bone formation and angiogenesis in osteoporotic bone defects, which provides a promising new strategy for repairing bone defects in osteoporotic conditions.

Effects of combined menaquinone-4 and PTH1-34 treatment on osetogenesis and angiogenesis in calvarial defect in osteopenic rats.

PURPOSE: The aim of this study was to evaluate the effect of combining human parathyroid hormone (1-34) (PTH1-34; PTH) and menaquinone-4 (MK-4) on calvarial bone defect repair in osteopenic rats. METHODS: Fourteen week olds were subject to craniotomy for the establishment of osteopenic animal models fed through a chronically low-protein diet. After that, critical calvarial defect model was established and all rats were randomly divided into four groups: sham, MK-4, PTH, and PTH + MK-4. The animals received MK-4 (30 mg/kg/day), PTH1-34 (60 µg/kg, three times a week), or PTH1-34 (60 µg/kg, three times a week) plus MK-4 (30 mg/kg/day) for 8 weeks, respectively. Serum γ-carboxylated osteocalcin (Gla-OC) levels, histological and immunofluorescent labeling were employed to evaluate the bone formation and mineralization in calvarial bone defect. In addition, Microfil perfusion, immunohistochemical, and micro-CT suggested enhanced angiogenesis and bone formation in calvarial bone healing. RESULTS: In this study, treatment with either PTH1-34 or MK-4 promoted bone formation and vascular formation in calvarial bone defects compared with the sham group. In addition, combined treatment of PTH1-34 plus MK-4 increased serum level of Gla-OC, improved vascular number and vascular density, and enhanced bone formation in calvarial bone defect in osteopenic conditions as compared with monotherapy. CONCLUSIONS: In summary, this study indicated that PTH1-34 plus MK-4 combination therapy accelerated bone formation and angiogenesis in calvarial bone defects in presence of osteopenia.

Chitosan oligosaccharide promotes osteoclast formation by stimulating the activation of MAPK and AKT signaling pathways.

Chitosan Oligosaccharide (COS) has been widely used for the systemic treatment of clinical diseases such as bone tissue engineering. However, its influence on osteoclast formation, which plays a critical role in bone homeostasis, has never been investigated. The aim of this study was to investigate the effect of chitosan oligosaccharide on differentiation of osteoclast. Using cell counting kit-8, tartrate-resistant acid phosphatase staining, reverse transcription­quantitative polymerase chain reaction assay and western blot analysis, we demonstrated that chitosan oligosaccharide cannot inhibit RANKL-induced osteoclast precursor proliferation but does promote osteoclast differentiation by stimulating the activation of p38/mitogen-activated protein kinase (MAPK), c-Jun N-terminal kinase (JNK)/MAPK, extracellular signal-regulated kinase (ERK)/MAPK and protein kinase B (AKT) without affecting nuclear factor kappaB (NF-kB) signaling pathways. Based on the promoting effect of chitosan oligosaccharide on osteoclast differentiation, we suggest that this property of chitosan oligosaccharide may have potential detrimental effect on bone homeostasis.

Baicalin is an inhibitor of subgroup J avian leukosis virus infection.

Avian leukosis virus subgroup J (ALV-J) can cause great economic losses to the poultry industry worldwide. Baicalin, one of the flavonoids present in S.baicalensis Georgi, has been shown to have antiviral activities. To investigate whether baicalin has antiviral effects on the infection of ALV-J in DF-1 cells, the cells were treated with baicalin at different time points. We found that baicalin could inhibit viral mRNA, protein levels and overall virus infection in a dose- and time-dependent manner using a variety of assays. Baicalin specifically targeted virus internalization and reduced the infectivity of ALV-J particles, but had no effect on the levels of major ALV-J receptor and virus binding to DF-1 cells. Collectively, these results suggest that baicalin might have potential to be developed as a novel antiviral agent for ALV-J infection.

Effects of combined human parathyroid hormone (1-34) and menaquinone-4 treatment on the interface of hydroxyapatite-coated titanium implants in the femur of osteoporotic rats.

The objective of this study was to investigate the effects of human parathyroid hormone (1-34) (PTH1-34; PTH) plus menaquinone-4 (vitamin K2; MK) on the osseous integration of hydroxyapatite (HA)-coated implants in osteoporotic rats. Ovariectomized female Sprague-Dawley rats were used for the study. Twelve weeks after bilateral ovariectomy, HA-coated titanium implants were inserted bilaterally in the femoral medullary canal of the remaining 40 ovariectomized rats. All animals were then randomly assigned to four groups: Control, MK, PTH and PTH + MK. The rats from groups MK, PTH and PTH + MK received vitamin K2 (30 mg/kg/day), PTH1-34 (60 µg/kg, three times a week), or both for 12 weeks. Thereafter, serum levels of γ-carboxylated osteocalcin (Gla-OC) were quantitated by ELISA and the bilateral femurs of rats were harvested for evaluation. The combination of PTH and MK clearly increased the serum levels of Gla-OC (a specific marker for bone formation) compared to PTH or MK alone. The results of our study indicated that all treated groups had increased new bone formation around the surface of implants and increased push-out force compared to Control. In addition, PTH + MK treatment showed the strongest effects in histological, micro-computed tomography and biomechanical tests. In summary, our results confirm that treatment with PTH1-34 and MK together may have a therapeutic advantage over PTH or MK monotherapy on bone healing around HA-coated implants in osteoporotic rats.

Negative voltage modulated multi-level resistive switching by using a Cr/BaTiOx/TiN structure and quantum conductance through evidence of H2O2 sensing mechanism.

Negative voltage modulated multi-level resistive switching with quantum conductance during staircase-type RESET and its transport characteristics in Cr/BaTiOx/TiN structure have been investigated for the first time. The as-deposited amorphous BaTiOx film has been confirmed by high-resolution transmission electron microscopy. X-ray photo-electron spectroscopy shows different oxidation states of Ba in the switching material, which is responsible for tunable more than 10 resistance states by varying negative stop voltage owing to slow decay value of RESET slope (217.39 mV/decade). Quantum conductance phenomenon has been observed in staircase RESET cycle of the memory devices. By inspecting the oxidation states of Ba+ and Ba2+ through measuring H2O2 with a low concentration of 1 nM in electrolyte/BaTiOx/SiO2/p-Si structure, the switching mechanism of each HRS level as well as the multi-level phenomenon has been explained by gradual dissolution of oxygen vacancy filament. Along with negative stop voltage modulated multi-level, current compliance dependent multi-level has also been demonstrated and resistance ratio up to 2000 has been achieved even for a thin (<5 nm) switching material. By considering oxidation-reduction of the conducting filaments, the current-voltage switching curve has been simulated as well. Hence, multi-level resistive switching of Cr/BaTiOx/TiN structure implies the promising applications in high dense, multistate non-volatile memories in near future.