RESUMEN

Steroid-induced osteonecrosis of the femoral head (SONFH) is the predominant cause of non-traumatic osteonecrosis of the femoral head (ONFH). Impaired blood supply and reduced osteogenic activity of the femoral head are the key pathogenic mechanisms of SONFH. Fibroblast growth factor 23 (FGF23) levels are not only a biomarker for early vascular lesions caused by abnormal mineral metabolism, but can also act directly on the peripheral vascular system, leading to vascular pathology. The aim of this study was to observe the role of FGF23 on bone microarchitecture and vascular endothelium, and to investigate activation of pyroptosis in SONFH. Lipopolysaccharide (LPS) combined with methylprednisolone (MPS) was applied for SONFH mouse models, and adenovirus was used to increase or decrease the level of FGF23. Micro-CT and histopathological staining were used to observe the structure of the femoral head, and immunohistochemical staining was used to observe the vascular density. The cells were further cultured in vitro and placed in a hypoxic environment for 12 h to simulate the microenvironment of vascular injury during SONFH. The effect of FGF23 on osteogenic differentiation was evaluated using alkaline phosphatase staining, alizarin red S staining and expression of bone formation-related proteins. Matrigel tube formation assay in vitro and immunofluorescence were used to detect the ability of FGF23 to affect endothelial cell angiogenesis. Steroids activated the pyroptosis signaling pathway, promoted the secretion of inflammatory factors in SONFH models, led to vascular endothelial dysfunction and damaged the femoral head structure. In addition, FGF23 inhibited the HUVECs angiogenesis and BMSCs osteogenic differentiation. FGF23 silencing attenuated steroid-induced osteonecrosis of the femoral head by inhibiting the pyroptosis signaling pathway, and promoting osteogenic differentiation of BMSCs and angiogenesis of HUVECs in vitro.

Asunto(s)

RESUMEN

Hypoxia can lead to programmed osteoblast death. Prevention of osteoblast apoptosis caused by hypoxia is of great significance in the study of the occurrence and development of bone necrosis. The present study aimed to investigate the effects and mechanism of fibroblast growth factor 23 (FGF23) on hypoxia­induced apoptosis in primary osteoblasts and MC3T3­E1 cells osteoblasts. Cells were transfected with a plasmid carrying the FGF23 gene and a cell model of hypoxia­induced apoptosis was established. FGF23 mRNA levels were measured using reverse transcription­quantitative (RT­q) PCR and western blotting was used to assess protein levels. Apoptosis was analyzed by MTT assay, fluorescein diacetate and ethidium bromide staining, flow cytometry and RT­qPCR and western blotting were used to verify the mRNA and protein levels of apoptosis­ and autophagy­related gene mRNA. The targeted relationship between miR­17­5p and FGF23 was confirmed using the StarBase database, TargetScan database and a luciferase reporter assay. FGF23 decreased cell survival and increased the rate of apoptosis. The mRNA and protein expression of the pro­apoptotic genes Bax and caspases 3 and 9 increased, whereas that of the anti­apoptotic Bcl­2 decreased. The expressions of the autophagy­associated proteins beclin­1, light chain 3­II (LC3­II) and the LC3­II/LC3­I ratio were significantly increased. In addition, a luciferase reporter assay confirmed that FGF23 directly regulated micro RNA (miR)­17­5p. The effects of FGF23 silencing were reversed by miR­17­5p inhibition. FGF23 may regulate hypoxia­induced osteoblast apoptosis by targeting miR­17­5p through the autophagy­signaling pathway. This provides a rationale for FGF23 as a potential therapeutic target for osteonecrosis of the femoral head.

Asunto(s)

RESUMEN

BACKGROUND: Increasing evidences have been indicated that FGF23 is associated with the biological behavior of malignant tumors, but its role in osteosarcoma and the specific mechanism need to be elucidated. The purpose of this study is to investigate the effects of FGF23 on the proliferation, migration and invasion of osteosarcoma cells, and the possible molecular mechanisms. METHODS: Western blot was used to detect differences in FGF23 expression in osteosarcoma cells MG-63 and U2-OS and osteoblasts hFOB1.19. FGF23-overexpressing adenoviruses and FGF-silencing plasmids were transfected into osteosarcoma cells, and transfection efficiency was verified using Western blot. MTT and colony formation assays were performed to detect osteosarcoma cell proliferation. Cell cycle was measured by flow cytometry. Scratch assay, holographic imaging cell analyzer Holomonitor ® M4 and transwell were applied to detect cell migration and invasion. Dual-luciferase reporter assay was performed to validate the interaction between FGF23 and miR-340-5p. Changes in miR-340-5p mRNA levels were measured by QRT-PCR. RESULTS: FGF23 is highly expressed in osteosarcoma cells compared to hFOB1.19. Overexpression of FGF23 significantly promoted the proliferation, migration and invasion of MG-63 and U2-OS cells. MiR-340-5p is a target of FGF23. Transfection of miR-340-5p mimics reversed the promoting effects of FGF23 on proliferation, migration and invasion of MG-63 and U2-OS cells. CONCLUSION: FGF23 promotes osteosarcoma cell proliferation, migration and invasion by targeting miR-340-5p gene expression.

Asunto(s)

RESUMEN

BACKGROUND: Atherosclerosis is a common cardiovascular disease in parrots but the antemortem diagnosis is challenging. In human medicine, computed tomography angiography (CTA) has been used widely for the diagnosis of atherosclerosis. By adjusting the injection rate and total dose of contrast medium, the image quality can be improved. To test the effects of different injection conditions on the image quality of major arteries, 10 African grey parrots (Psittacus erithacus) were used. Three injection rates (0.3, 0.4, 0.5 mL/s) and three doses (740, 370, 222 mg of iodine/bird) were tested while the other variables of the studies were fixed. RESULT: A higher injection dose led to a significantly higher attenuation, image noise and diameter, with a lower signal-to-noise ratio and contrast-to-noise ratio of the six major arteries. The 370 mg of iodine/bird group showed significantly better subjective image quality. Furthermore, with increasing injection rates, the prevalence of heterogeneity decreased. However, we found an increased risk of injection failure for the 0.5 mL/s groups. CONCLUSION: We recommend a combination of 370 mg of iodine/bird with 0.4 mL/s for clinical use to achieve better image quality for CTA.

Asunto(s)

RESUMEN

Objective: Glucocorticoid-induced osteonecrosis of the femoral head is one of the most common causes of nontraumatic osteonecrosis of the femoral head, but its exact pathogenesis remains unclear. The aim of this study was to investigate the role of SIRT6 in the maintenance of bone tissue morphology and structure, intravascular lipid metabolism, and its potential molecular mechanism in glucocorticoid-induced osteonecrosis of the femoral head. Methods: SIRT6 adenovirus was transfected into GIONFH in rats. The microstructure of rat bone was observed by micro-CT and histological staining, and the expression of bone formation-related proteins and angiogenesis-related factors was determined through western blot and immunohistochemistry. Alkaline phosphatase activity, alizarin red staining, and the expression levels of Runx2 and osteocalcin were used to evaluate the osteogenic potential. And in vitro tube formation assay and immunofluorescence were used to detect the ability of endothelial cell angiogenesis. Results: Dexamethasone significantly inhibited osteoblast differentiation, affected bone formation, and destroyed microvessel formation, increased the intracellular Fe2+ and ROS levels and induced the occurrence of ferroptosis. SIRT6 can inhibit ferroptosis and restore the ability of bone formation and angiogenesis. Conclusion: SIRT6 can inhibit the occurrence of ferroptosis, reduce the damage of vascular endothelium, and promote osteogenic differentiation, so as to prevent the occurrence of osteonecrosis of the femoral head.

Asunto(s)

RESUMEN

BACKGROUND: Osteonecrosis of the femoral head (ONFH) is a common hip joint disease, which is more harmful and seriously affects the lives of patients. This study aims to clarify the regulatory mechanism of lncRNA FGD5-AS1 in ONFH. METHODS: The expression of the protein and mRNA was detected by RT-qPCR and Western blot assay. The regulatory mechanism of lncRNA FGD5-AS1 was detected by the dual-luciferase reporter assay, CCK-8 assay, and flow cytometry assay. RESULTS: Dex can inhibit cell proliferation and differentiation and induce apoptosis in hBMSCs in a dose-dependent manner. Overexpression of lncRNA FGD5-AS1 promoted cell proliferation and restrained apoptosis in Dex-treated hBMSCs. In addition, lncRNA FGD5-AS1 acts as a sponge for miR-296-5p. Also, miR-296-5p directly targets STAT3. More importantly, miR-296-5p and STAT3 can affect the function of lncRNA FGD5-AS1 in Dex-treated hBMSCs. CONCLUSION: lncRNA FGD5-AS1 promotes cell proliferation and inhibits apoptosis in steroid-induced ONFH through acting as a sponge for miR-296-5p and upregulation of STAT3.

Asunto(s)

RESUMEN

OBJECTIVE: To investigate the biomechanical and elution properties of meropenem-loaded bone cement. METHODS: Bone cement (Palacos LV) with 5% (2 g/4 0g), 10% (4 g/40 g), and 15% (6 g/40 g) meropenem; 5% (2 g/40 g) and 10% (4 g/40 g) vancomycin; and blank bone cement were prepared in a total of six groups named A2, A4, A6, B2, B4, and A0 (antibiotic-free). 36 cylinder specimens (6-mm diameter and 12-mm height) of all six groups were molded for a compression test. After the compression test, because of mechanical properties below the ISO standard requirements, groups B2, B4 were not subjected to a bending test. So a total of 24 rectangular strip specimens (10-mm width, 75-mm length, and 3.3-mm thickness) for groups A2, A4, A6 and A0 were molded for the bending test. Between-group differences of compressive strength, bending strength and bending modulus were analyzed. The meropenem standard was prepared as a series of standard solutions to calculate the standard curve. At a constant temperature of 37 °C, separately, meropenem-loaded bone cement cylinder specimens (12 mm in diameter and 17 mm in length) of A2, A4 and A6 were serially immersed in saline solution without stirring. The eluent drug concentration at 24, 48, 72 h and 6, 12, 24 days was measured and the drug concentration-time curve of meropenem was constructed. RESULTS: With the exception of groups B2 and B4, all cements compressive strength values were well above the minimum requirement of the ISO 5833 standard (70 MPa). The compressive strength and bending strength values of group A4 were higher than those of group A0 (P < 0.05), but no difference was found between the A0, A2 and A6 groups (P > 0.05). There were no intergroup differences of bending modulus between the A0, A2, A4 and A6 groups (P > 0.05). A standard curve of meropenem was obtained and a regression equation was constructed: Y = 15.0265 X + 13.5218, r = 1.00. At 37 °C, the release of meropenem was rapid during the first 48 h for all A2, A4, A6 samples, and subsequent release continued to decrease. CONCLUSION: When adding up to 15% (6 g/40 g) meropenem to the bone cement, the biomechanical properties were not reduced, and bone cement with 10% (4 g/40 g) meropenem had the best performance. At a constant temperature of 37°C, meropenem can be released from bone cement for up to 24 days.

Asunto(s)

RESUMEN

OBJECTIVE: To investigate the risk factors for, and outcomes of, preoperative asymptomatic pulmonary embolism (PE) in patients ≥60 years old following delayed operation for hip fracture. METHODS: From March 2017 to December 2018, 90 patients aged ≥60 years with hip fracture who suffered a delay in surgery were recruited to this prospective study following admission to our hospital. Computed tomography pulmonary angiography (CTPA) was used to detect preoperative asymptomatic PE and calculated its incidence. Time from injury to admission, baseline characteristics, medical comorbidities, and blood biomarker levels were evaluated as potential risk factors. Logistic regression analysis was used to identify risk factors. Mortality and major bleeding events were recorded and compared between individuals with PE and without. Data were analyzed by t-test, Mann-Whitney U test, χ2 test, Fisher's exact test, and logistic regression analysis. RESULTS: The incidence of preoperative asymptomatic PE was 18.9% (17/90 patients). In the univariate analysis, the risk factors for preoperative asymptomatic PE were male sex, hypertension, cerebrovascular accident, smoking, plasma D-dimer level, potassium level, urea level, creatinine level, and cysteine level. Multivariate logistic regression analysis showed that the risk of preoperative asymptomatic PE was higher in patients with hypertension (odds ratio [OR] = 10.048; 95% confidence interval [CI], 1.118-90.333), cerebrovascular accident (OR = 20.135; 95% CI, 1.875-216.164), smoking (OR = 48.741; 95% CI, 4.155-571.788), high plasma D-dimer levels (OR = 1.200; 95% CI, 1.062-157.300), and high plasma potassium levels (OR = 12.928; 95% CI, 1.062-157.300). All patients were followed up for 21.0 months (range, 2 to 36 months). Mortality within the first year postoperatively was higher in patients with PE (29.41% vs 9.59%, P = 0.046). CONCLUSIONS: In view of the high incidence of preoperative asymptomatic PE and the inferior prognosis in individuals with PE, routine CTPA examination for preoperative asymptomatic PE could be useful for patients aged ≥60 years with hip fracture for whom surgery is delayed.

Asunto(s)

RESUMEN

PURPOSE: A number of studies have discovered various roles of PAK4 in human tumors, including osteosarcoma. However, the exact role of PAK4 in osteosarcoma and its mechanism have yet to be determined. Therefore, this study focused on interrogating the PAK4 effect on the proliferation and migration ability of osteosarcoma and its underlying mechanisms. MATERIALS AND METHODS: Western blot and QRT-PCR were utilized to quantify the PAK4 relative protein and mRNA levels. To measure cellular viability and mobility, the MTT and wound-healing assays were preferred. RESULTS: With the adenovirus-mediated overexpression of PAK4, the proliferation and migration of U2-OS and MG-63 osteosarcoma cells were stimulated. Furthermore, a liposome-mediated knockout of PAK4 will inhibit osteosarcoma cells from proliferating. In terms of mechanism, we observed the positive correlation of PAK4 expression with expression of P21, CyclinD1, CyclinE1, CDK2, and CDK6, which drives G0/G1 to the G2/M phase transition. PAK4 can also activate Erk expression in OS cells and induce EMT. CONCLUSION: Interfering with PAK4 protein expression has been shown to affect osteosarcoma proliferation and migration.

Asunto(s)

RESUMEN

This study aimed to discuss the risk factors of perioperative blood transfusion after the application of proximal femoral nail antirotation (PFNA) in the treatment of elderly patients with femoral intertrochanteric fracture (FIF). Moreover, this study also aimed to analyze the causes of perioperative blood transfusion and provide guidance for clinical treatment.Records of elderly patients with FIF who were treated with PFNA in our hospital from September 2014 to May 2017 were reviewed. They were divided into transfused and nontransfused groups. The Student t test, Chi-squared test, and Fisher exact test were used in univariate analysis of 11 variables. Multivariate logistic regression analysis was performed to analyze the possible risk factors associated with postoperative blood transfusion after the application of PFNA in elderly patients with FIF. Correlations were sought using the Spearman rank correlation analysis.The univariate analysis showed that age, sex, type of fracture, admission hemoglobin (Hb), admission albumin, and intraoperative blood loss were significantly associated with perioperative blood transfusion (P = .000, .019, .000, .000, .000, and .007, respectively). The multivariate logistic regression analysis demonstrated that age (P = .019, odds ratio [OR] = 1.062), type of fracture (P = .001, OR = 4.486), and admission Hb (P = .000, OR = 0.883) were independent risk factors of postoperative blood transfusion. We found a significant positive correlation between perioperative blood transfusion and age (r = 0.264, P = .000) and type of fracture (r = 0.409, P = .000), but a negative correlation between perioperative blood transfusion and admission Hb (r = -0.641, P = .000).The main factors affecting perioperative blood transfusion are age, fracture type, and admission Hb. These results indicate that, in high-risk patients who are older in age, more unstable fractures, and lower admission Hb, monitoring Hb concentrations during the perioperative period is important to correct severe anemia in a timely manner and avoid exacerbating existing underlying diseases and inducing severe complications.

Asunto(s)

RESUMEN

Objective To explore the effects of psychology of caregivers of children with cerebral palsy on family management.Meth-ods From August,2013 to August,2014,the main caregivers of 222 children with cerebral palsy were investigated with questionnaires of de-mography,Connor-Davidson Resilience Scale(CD-RISC),Index of Well-being,Self-rating Anxiety Scale(SAS),Self-rating Depression Scale(SDS)and Family Management Measure(FaMM).Results The scores of Condition Management Ability,View of Condition Impact, Condition Management Effort, Family Life Difficulty and Parental Mutuality of FaMM were higher than the median (t>8.866, P<0.001). The scores of CD-RISC,SAS and SDS were less than the norms of Chinese(t>5.523,P<0.001).Index of Well-being was(7.63±2.96).The factors related with the dimensions of family management included the time of hospitalization of children,the expectation of rehabilitation, the levels of anxiety and psychological resilience,and the index of well-being of the parents(P<0.05).Conclusion The psychology of care-givers of children with cerebral palsy and family management are dissatisfactory,and the psychology may influence family management.