•The relationship between cage-E and the biomechanical properties of TLIF was successfully determined based on logarithmic regression and finite element analyses.•The established functional equations ...provide a way to directly guide the rapid development and optimization of novel cage materials.•As cage-E increased from 0.1 to 110 GPa, the risks of cage subsidence and pseudarthrosis and the mechanical requirement of the cages decreased, whereas the risk of instrumentation failures simultaneously increased.
Conventional method for evaluating the biomechanical effects of a specific elastic modulus of cage (cage-E) on spinal fusions requires establishing a “one-on-one” biomechanical model, which seems laborious and inefficient when dealing with the emergence of numerous cage materials with various cage-Es. We aim to offer a much convenient method to instantly predicting the biomechanical effects of any targeted cage-E on transforaminal lumbar interbody fusion (TLIF) by using a parametric finite element (FE) analysis to determining the regression relationship between cage-E and biomechanical properties of TLIF.
A L4/5 FE TLIF construct was modeled. Cage-E was linearly increased from 0.1 GPa (cancellous bone) to 110 GPa (titanium alloy). The function equations for assessing the influence of cage-E on the biomechanical indexes of TLIF were established using a logarithmic regression analysis.
As cage-E increased from 0.1 GPa to 110 GPa, all the biomechanical indexes initially increased or decayed rapidly, and then slowed over time. Logarithmic regression models and functional equations were successfully established between cage-E and these indexes (P<0.0001). Their determination coefficients ranged from 0.72 to 0.99. The range of motions decreased from 0.37–1.10° to 0.20–1.07°. The mean stresses of the central and peripheral grafts reduced from 0.10–0.41 and 0.25–0.42 MPa to 0.03–0.04 and 0.19–0.27 MPa, respectively. In addition, the maximum stresses of the screw-bone interface and posterior instrumentation reduced from 11.76-25.04 and 8.91–84.68 MPa to 9.71–18.92 and 6.99–70.59 MPa, respectively. Finally, the maximum stresses of the cage and endplate increased from 0.28-1.35 MPa and 3.90–8.63 MPa to 14.86–36.16 MPa and 11.01–36.55 MPa, respectively.
The decrease of cage-E reduces the risks of cage subsidence, cage breakage, and pseudarthrosis, while increasing the risk of instrumentation failure. The logarithmic regression models optimally demonstrate the relationship between cage-E and biomechanical properties of TLIF. The functional equations based on these models can be adopted to predict the biomechanical effects of any targeted cage-Es on TLIF, which effectively simplifies the procedures for the biomechanical assessments of cage materials.
A potential load-bearing bone substitution and repair material, that is, carbon fiber (CF)-reinforced magnesium-doped hydroxyapatite (CF/Mg-HAs) composites with excellent mechanical performance and ...tailored biological properties, was constructed via the hydrothermal method and spark plasma sintering. A high-resolution transmission electron microscopy (TEM) was employed to characterize the nanostructure of magnesium-doped hydroxyapatite (Mg-HA). TEM images showed that the doping of Mg-induced distortions and dislocations in the hydroxyapatite lattice, resulting in decreased crystallinity and enhanced dissolution. Compressive strengths of 10% magnesium-doped hydroxyapatite (1Mg-HAs) and CF-reinforced 1Mg-HAs (CF/1Mg-HAs) were within the range of that of cortical bone. Compared with 1Mg-HAs, the fracture toughness of CF/1Mg-HAs increased by approximately 38%. The bioactivity, biocompatibility, and osteogenic induction properties of Mg-HAs and CF/Mg-HAs composites were evaluated in vitro using simulated body fluid (SBF) immersion, cell culture, osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs), and expression of genes associated with osteogenesis. When Mg-HAs were immersed in SBF, Mg
continued to release for up to 21 days. Mg-HAs demonstrated a satisfactory ability to induce apatite formation in comparison with HAs. The cell proliferation and morphology on CF/1Mg-HAs were similar to those of 1Mg-HAs, suggesting that adding CF had no adverse effect on cellular activity. The expression levels of osteogenesis-related genes osteocalcin (
), osteopontin (
), and runt-related transcription factor 2 (
) on 1Mg-HAs were significantly higher at days 3 and 7 than those on HAs and 0.5Mg-HAs groups. This finding suggests that a certain amount of Mg doping had beneficial influences in the different stages of osteogenic differentiation and could induce osteogenic differentiation of BMSCs. The new bone volume to total volume ratio of implanted 1Mg-HAs (30.9% ± 4.1%) and CF/1Mg-HAs (25.4% ± 5.4%) was remarkably higher than that of HAs (21.6% ± 3.9%). 1Mg-HAs and CF/1Mg-HAs tailored an ideal effect of new bone information and implant osseointegration. The excellent mechanical performance and tailored biological properties of CF/Mg-HAs were attributed to nano Mg-doped HA, CF reinforcing, refined microstructure, and controlled composition.
Hydroxyapatite （HA, Ca10（PO4）6（OH）2） coating was fabricated on pure Ti （TA2） by laser cladding technology. The phase structure, microstructure, microhardness and electrochemical behavior of the laser ...cladded HA coating in artificial body fluid were investigated. The results show that the HA coating is mainly composed of highly crystallized HA. A transitional layer between HA coating and Ti substrate is formed. Microhardness measurement shows the gradually increasing of microhardness from 150 HV at TA2 substrate to 600 HV at transitional layer, and followed by a decreasing to 400 HV at HA coated layer. Electrochemical corrosion tests show that the HA coating has higher open circuit potential , lower corrosion current density and corrosion rate in comparison to the TA2 substrate.
SNAP-25 is one of the key proteins involved in formation of soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complexes that are at the core of hormonal secretion and ...synaptic transmission. Altered expression or function of SNAP-25 can contribute to the development of neuropsychiatric and metabolic disease. A dominant negative (DN) I67T missense mutation in the b-isoform of SNAP-25 (DN-SNAP25mut) mice leads to abnormal interactions within the SNARE complex and impaired exocytotic vesicle recycling, yet the significance of this mutation to any association between the central nervous system and metabolic homeostasis is unknown.
Here we explored aspects of metabolism, steroid hormone production and neurobehavior of DN-SNAP25mut mice.
DN-SNAP25mut mice displayed enhanced insulin function through increased Akt phosphorylation, alongside increased adrenal and gonadal hormone production. In addition, increased anxiety behavior and beigeing of white adipose tissue with increased energy expenditure were observed in mutants.
Our results show that SNAP25 plays an important role in bridging central neurological systems with peripheral metabolic homeostasis, and provide potential insights between metabolic disease and neuropsychiatric disorders in humans.
•Dominant negative SNAP-25 results in enhanced insulin action in mice•Dominant negative SNAP-25 results in increased adrenal and hormonal production•Mice with dominant negative SNAP-25 display increased anxiety•Dominant negative SNAP-25 causes increased energy expenditure and beigeing of fat
Cannabidiol, a major component of marijuana, protects nerves, and exerts antispasmodic, anti-inflammatory and anti‑anxiety effects. In the current study, the protective effect of cannabidiol was ...observed to prevent hydrogen peroxide (H2O2)‑induced apoptosis, inflammation and oxidative stress in nucleus pulposus cells. Nucleus pulposus cells were isolated from rats and cultured in vitro, and H2O2 was used to construct the nucleus pulposus cell model. Cell viability of the nucleus pulposus cells was assessed using a 3‑(4,5-dimethylthiazol-2-yl)-2,5‑diphenyltetrazolium bromide assay. The ratio of apoptotic cells, and caspase‑3 or cyclooxygenase‑2 (COX‑2) mRNA expression was analyzed by annexin V‑fluorescein isothiocyanate/propidium‑iodide staining and reverse transcription‑quantitative polymerase chain reaction, respectively. The quantities of interleukin (IL)‑1β and interleukin‑6 were measured using a series of assay kits. B-cell lymphoma 2 (Bcl‑2) and inducible nitric oxide synthase (iNOS) protein expression levels were analyzed using western blotting. The present study identified that cannabidiol enhanced cell viability and reduced apoptosis in H2O2‑treated nucleus pulposus cells in vitro using a lumbar disc herniation (LDH) model. In addition, cannabidiol reduced caspase‑3 gene expression and augmented the Bcl‑2 protein expression levels in the nucleus pulposus cells following H2O2 exposure. Pre‑treatment with cannabidiol suppressed the promotion of COX‑2, iNOS, IL‑1β and IL‑6 expression in the nucleus pulposus cells following H2O2 exposure. Taken together, these results suggest that cannabidiol potentially exerts its protective effect on LDH via the suppression of anti‑apoptosis, anti‑inflammation and anti‑oxidative activities in nucleus pulposus cells.
Low levels of the indispensable trace element selenium (Se) can cause oxidative stress and disrupt environmental homeostasis in humans and animals. Selenoprotein S (Selenos), of which Se is a key ...component, is a member of the selenoprotein family involved in various biological processes. This study aimed to investigate whether low-level SELENOS gene expression can induce oxidative stress and decrease the antioxidative capacity of chondrocytes. Compared with control cells, SELENOS-knockdown ATDC5 cells showed substantially higher dihydroethidium, reactive oxygen species and malondialdehyde levels, and lower superoxide dismutase (SOD) expression. Knockout of the gene in C57BL/6 mice increased the 8-hydroxy-2-deoxyguanosine level considerably and decreased SOD expression in cartilages relative to the levels in wild-type mice. The results showed that the increased nuclear factor erythroid 2-related factor 2/heme oxygenase-1 signaling mediated by low-level SELENOS expression was involved in oxidative damage. The proliferative zone of the cartilage growth plate of SELENOS-knockout mice was shortened, suggesting cartilage differentiation dysfunction. In conclusion, this study confirmed that low-level Selenos expression plays a role in oxidative stress in cartilages.
Epigenetic targets of polyphenols in cancer Yang, Pinglin; He, Xijing; Malhotra, Anshoo
Journal of environmental pathology, toxicology and oncology,
2014, Letnik:
33, Številka:
2
Journal Article
Recenzirano
Interest in dietary polyphenols has recently increased greatly owing to their antioxidant capacity and their possible beneficial implications in various pathological states, including cancer. ...Polyphenols are a group of chemicals found in many fruits, vegetables, and plants and have the ability to remove free radicals from the body. In the last 2 decades, the numbers of reports on the potential health benefits of polyphenols have increased. This review provides the available scientific data that justify importance of polyphenols in correlation with epigenetics to fight against carcinogenesis. Epigenetics involves genetic control by mechanisms other than DNA sequence. These epigenetic mechanisms have ability to switch on or off various important genes influencing the process of cancer. Furthermore, due to the reversible nature of these epigenetic mechanisms, they are influenced by a variety of dietary polyphenols. This review focuses on the dietary polyphenols that significantly affect these epigenetic mechanisms to mitigate carcinogenesis.
The aim of our study was to evaluate the clinical efficacy of posterior vs. anterior instrumentation for the treatment of spinal tuberculosis in adults.
The electronic databases such as PubMed, ...MEDLINE, Springer, EMBASE, Google scholar, and Cochrane library were searched to select the potentially relevant reports that compared the efficacy of posterior instrumentation group (group A) with anterior instrumentation group (group B) in the treatment of spinal tuberculosis. Outcome assessments were correction of angle, loss of correction, fusion rate of the grafting bone, and complications after surgery.
This meta-analysis included four trials published between 2006 and 2012, involving 291 adult patients (group A, 154; group B, 137) with spinal tuberculosis. The overall meta-analysis showed that there were no significant differences (P>0.01) between group A and group B in correction of angle and loss of correction at final follow-up after operation The pooled WMD (weighted mean difference) of group A and group B was 2.85 (95% CI (confidence interval) = -1.25~6.94) and 1.14 (95% CI=-3.07~5.34), respectively. Besides, no significant differences (P>0.01) were observed in fusion rate of the grafting bone and complications after operation between group A and group B, and the pooled ORs (odds ratio) were 0.65 (95% CI=-0.23~1.85) and (95% CI=-0.19~1.50), respectively.
Our results suggested that the posterior instrumentation appeared to have the same clinical outcome with the anterior instrumentation in the treatment of the adult patients with spinal tuberculosis.
To compare the effectiveness between paratricipital approach and chevron olecranon V osteotomy approach for the treatment of type C3 (AO/OTA) distal humeral fractures and investigate the details of ...operation.
Between April 2010 and September 2016, 36 type C3 (AO/OTA) distal humeral fractures were treated with open reduction and bicolumnar orthogonal locking plating fixation by paratricipital approach and chevron olecranon V osteotomy approach respectively. The patients were divided into 2 groups by approach, there were 17 cases in paratricipital group (group A) and the bicolumns and distal humeral joint surface were exposed by traction of triceps and olecranon, and the distal humeral joint surface of the 19 cases in chevron olecranon V osteotomy group (group B) were exposed by osteotomy of the olecranon and reversing of triceps. There was no significant difference in gender, age, dominant side, interval between injury and surgery, causes of injury between 2 groups (
>0.05). Patients were followed up, the post
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