There is evidence that fractures heal more rapidly in patients with head injury. We measured the circulating level of
Objectives. Recently, high failure rates of metal-on-metal (MOM) hip implants have raised concerns of cobalt toxicity. Adverse reactions occur to cobalt nanoparticles (CoNPs) and cobalt ions (Co. 2+. ) during wear of MOM hip implants, but the toxic mechanism is not clear. Methods. To evaluate the protective effect of zinc ions (Zn. 2+. ), Balb/3T3 mouse fibroblast cells were pretreated with 50 μM Zn. 2+. for four hours. The cells were then exposed to different concentrations of CoNPs and Co. 2+. for four hours, 24 hours and 48 hours. The cell viabilities, reactive oxygen species (ROS) levels, and inflammatory cytokines were measured. Results. CoNPs and Co. 2+. can induce the increase of ROS and inflammatory cytokines, such as tumour necrosis factor α (TNF-α), interleukin-1β (IL-1β) and
We have undertaken a prospective study in patients with a fracture of the femoral shaft requiring intramedullary nailing to test the hypothesis that the femoral canal could be a potential source of the second hit phenomenon. We determined the local femoral intramedullary and peripheral release of
Objectives. The aim of this study was to investigate the effect of hyperglycaemia on oxidative stress markers and inflammatory and matrix gene expression within tendons of normal and diabetic rats and to give insights into the processes involved in tendinopathy. Methods. Using tenocytes from normal Sprague-Dawley rats, cultured both in control and high glucose conditions, reactive oxygen species (ROS) production, cell proliferation, messenger RNA (mRNA) expression of NADPH oxidase (NOX) 1 and 4,
This study intended to investigate the effect of vericiguat (VIT) on titanium rod osseointegration in aged rats with iron overload, and also explore the role of VIT in osteoblast and osteoclast differentiation. In this study, 60 rats were included in a titanium rod implantation model and underwent subsequent guanylate cyclase treatment. Imaging, histology, and biomechanics were used to evaluate the osseointegration of rats in each group. First, the impact of VIT on bone integration in aged rats with iron overload was investigated. Subsequently, VIT was employed to modulate the differentiation of MC3T3-E1 cells and RAW264.7 cells under conditions of iron overload.Aims
Methods
We describe a model which can be used for in vitro biocompatibility assays of biomaterials. We studied the in vitro response of human osteoarthritis or rheumatoid arthritis fibroblast-like synoviocytes to Al. 2. O. 3. or ZrO. 2. particles by analyzing the production of interleukin-1 (IL-1) and
We have investigated whether the particle-stimulated release of inflammatory cytokines from human primary macrophages in vitro was dependent upon the type of bone cement used. Particles of clinically relevant size were produced from Palacos R without radio-opacifier, Palacos R with BaSO. 4. , Palacos R with ZrO. 2. and from CMW3 which contains BaSO. 4. All four preparations produced significantly greater release of tumour necrosis factor alpha,
Periprosthetic bone loss after total joint arthroplasty is a major clinical problem resulting in aseptic loosening of the implant. Among many cell types, osteoblasts play a crucial role in the development of peri-implant osteolysis. In this study, we tested the effects of calcitriol (1α,25-dihydroxy-vitamin-D. 3. ) and the bisphosphonate pamidronate on titanium-particle- and TNF-α-induced release of
It has been suggested that reamed intramedullary nailing of the femur should be avoided in some patients with multiple injuries. We have studied prospectively the effect of femoral reaming on the inflammatory process as implicated in the pathogenesis of acute respiratory distress syndrome (ARDS) and multiple-organ failure (MOF). We studied changes in the levels of serum
Our aim was to determine whether in vitro studies would detect differences in the cellular response to wear particles of two titanium alloys commonly used in the manufacture of joint replacement prostheses. Particles were of the order of 1 μm in diameter representative of those found adjacent to failed prostheses. Exposure of human monocytes to titanium 6-aluminium 4- vanadium (TiAlV) at concentrations of 4 x 10. 7. particles/ml produced a mean prostaglandin E. 2. release of 2627.6 pM; this was significantly higher than the 317.4 pM induced by titanium 6-aluminium 7-niobium alloy (TiAlNb) particles (p = 0.006). Commercially-pure titanium particles induced a release of 347.8 pM. In addition, TiAlV stimulated significantly more release of the other cell mediators, interleukin-1, tumour necrosis factor and
The pathogenesis of aseptic loosening of total joint prostheses is not clearly understood. Two features are associated with loosened prostheses, namely, particulate debris and movement of the implant. While numerous studies have evaluated the cellular response to particulate biomaterials, few have investigated the influence of movement of the implant on the biological response to particles. Our aim was therefore to test the hypothesis that excessive mechanical stimulation of the periprosthetic tissues induces an inflammatory response and that the addition of particulate biomaterials intensifies this. We allocated 66 adult Beagle dogs to four groups as follows: stable implants with (I) and without (II) particulate polymethylmethacrylate (PMMA) and moving implants with (III) and without (IV) particulate PMMA. They were then evaluated at 2, 4, 6, 12 and 24 weeks. The stable implants were well tolerated and a thin, fibrous membrane of connective tissue was observed. There was evidence of positive staining in some cells for
Given the function of adiponectin (ADIPOQ) on the inflammatory condition of obesity and osteoarthritis (OA), we hypothesized that the ADIPOQ gene might be a candidate gene for a marker of susceptibility to OA. We systematically screened three tagging polymorphisms (rs182052, rs2082940 and rs6773957) in the ADIPOQ gene, and evaluated the association between the genetic variants and OA risk in a case-controlled study that included 196 OA patients and 442 controls in a northern Chinese population. Genotyping was performed using the Sequenom MassARRAY iPLEX platform.Objectives
Methods
The objective of this study was to investigate the therapeutic effect of peripheral blood mononuclear cells (PBMNCs) treated with quality and quantity control culture (QQ-culture) to expand and fortify angiogenic cells on the acceleration of fracture healing. Human PBMNCs were cultured for seven days with the QQ-culture method using a serum-free medium containing five specific cytokines and growth factors. The QQ-cultured PBMNCs (QQMNCs) obtained were counted and characterised by flow cytometry and real-time polymerase chain reaction (RT-PCR). Angiogenic and osteo-inductive potentials were evaluated using tube formation assays and co-culture with mesenchymal stem cells with osteo-inductive medium Objectives
Methods
Excessive mechanical stress on synovial joints causes osteoarthritis
(OA) and results in the production of prostaglandin E2 (PGE2), a
key molecule in arthritis, by synovial fibroblasts. However, the
relationship between arthritis-related molecules and mechanical
stress is still unclear. The purpose of this study was to examine
the synovial fibroblast response to cyclic mechanical stress using
an Human synovial fibroblasts were cultured on collagen scaffolds
to produce three-dimensional constructs. A cyclic compressive loading
of 40 kPa at 0.5 Hz was applied to the constructs, with or without
the administration of a cyclooxygenase-2 (COX-2) selective inhibitor
or dexamethasone, and then the concentrations of PGE2, interleukin-1β (IL-1β),
tumour necrosis factor-α (TNF-α), IL-6, IL-8 and COX-2 were measured.Objective
Method
Several experimental models have been used to produce intravascular fat embolism. We have developed a simple technique to induce fat embolism using corn oil emulsified with distilled water to form fatty micelles. Fat embolism was produced by intravenous administration of these fatty micelles in anaesthetised rats, causing alveolar oedema, haemorrhage and increased lung weight. Histopathological examination revealed fatty droplets and fibrin thrombi in the lung, kidney and brain. The arteriolar lumen was filled with fatty deposits. Following fat embolism, hypoxia and hypercapnia occurred. The plasma phospholipase A2, nitrate/nitrite, methylguidanidine and proinflammatory cytokines were significantly increased. Mass spectrometry showed that the main ingredient of corn oil was oleic acid. This simple technique may be applied as a new animal model for the investigation of the mechanisms involved in the fat embolism syndrome.