Aim. The aim of this study was to gain insight into the in vivo expression of virulence and metabolic genes of Staphylococcus aureus in a prosthetic joint infection in a human subject. Method. Deep RNA sequencing (RNA-seq) was used for transcriptome profile of joint fluid obtained from a patient undergoing surgery due to acute S. aureus prosthetic joint infection. The S. aureus
Treatment of segmental bone defects remains a major clinical problem, and innovative strategies are often necessary to successfully reconstruct large volumes of bone. When fractures occur, the resulting hematoma serves as a reservoir for growth factors and a space for cell infiltration, both crucial to the initiation of bone healing. Our previous studies have demonstrated very clear ultrastructural differences between fracture hematomas formed in normally healing fractures and those formed in segmental bone defects. However, there is little information available regarding potential differences in the underlying
Purpose. Traumatic articular cartilage (AC) defects are common in young adults and frequently progresses to osteoarthritis. Matrix-Induced Autologous Chondrocyte Implantation (MACI) is a recent advancement in cartilage resurfacing techniques and is a variant of ACI, which is considered by some surgeons to be the gold standard in AC regeneration. MACI involves embedding cultured chondrocytes into a scaffold that is then surgically implanted into an AC defect. Unfortunately, chondrocytes cultured in a normoxic environment (conventional technique) tend to de-differentiate resulting in decreased collagen II and increased collagen I producing in a fibrocartilagous repair tissue that is biomechanically inferior to AC and incapable of withstanding physiologic loads over prolonged periods. The optimum conditions for maintenance of chondrocyte phenotype remain elusive. Normal oxygen tension within AC is <7%. We hypothesized that hypoxic conditions would induce
Background. Current treatments for the prevention of thromboembolism include heparin and low-molecular weight heparins (LMWHs). A number of studies have suggested that long term administration of these drugs may adversely affect osteoblasts and therefore, bone metabolism. Xarelto(tm) (Rivaroxaban) is a new anti-thrombotic drug for the prevention of venous thromboembolism in adult patients undergoing elective hip and knee replacement surgery. The aim of this in vitro study was to investigate the possible effects of rivaroxaban on osteoblast proliferation, function, matrix mineralisation and
The bioactive polyetheretherketone (PEEK) was fabricated by the combination of PEEK and CaO-SiO. 2. particles, which formed hydroxyapatite on its surfaces in simulated body fluid and showed good mechanical propeties. The study revealed osteoblast-like cell proliferation and
A randomised controlled trial was conducted using a rabbit model of a complex contaminated extremity war wound. Compared to saline soaked gauze dressings Inadine (iodine) and Acticoat (nanocrystalline silver) had significantly lower levels of Staphylococcus aureus after 7 days while Activon Tulle (Manuka honey) had significantly higher levels. Molecular level analysis of the wound was conducted. Plasma cytokines of interest were assayed using ELISA and levels of expression of relevant tissue genes measured using PCR following RNA extraction. Appreciable levels of Interleukins 4 and 6 and Tumour Necrosis Factor-α were identified in plasma with significantly higher levels of IL-4 and TNFα detected in the Activon Tulle group. In tissue TNFα, Matrix metalloproteinase-3 and the ratio of Matrix metalloproteinase-9 to Tissue Inhibitor of Matrix metalloproteinase-1 were significantly higher in tissue injured limbs than the uninjured limbs with no significant differences between groups. Interpretation of these results is challenging. IL-4 has been associated with transition from pathological inflammation to repair and TNFα with impaired healing. However, Activon Tulle had significantly higher levels of S. aureus and we found no differences in observational, histology, haematology or tissue
Aim. The diagnosis of periprosthetic joint infection (PJI) in total joint arthroplasty (TJA) remains a serious clinical challenge. Nowadays, limited biomarkers associated with PJI are available. We investigated therefore the utility of
Aims. This study explored the shared genetic traits and molecular interactions between postmenopausal osteoporosis (POMP) and sarcopenia, both of which substantially degrade elderly health and quality of life. We hypothesized that these motor system diseases overlap in pathophysiology and regulatory mechanisms. Methods. We analyzed microarray data from the
Osteoarthritis (OA) is a disease of the synovial joint with synovial inflammation, capsular contracture, articular cartilage degradation, subchondral sclerosis and osteophyte formation contributing to pain and disability. Transcriptomic datasets have identified genetic loci in hip and knee OA demonstrating joint specificity. A limited number of studies have directly investigated transcriptional changes in shoulder OA. Further,
Periosteum is important for bone homoeostasis
through the release of bone morphogenetic proteins (BMPs) and their
effect on osteoprogenitor cells. Smoking has an adverse effect on
fracture healing and bone regeneration. The aim of this study was
to evaluate the effect of smoking on the expression of the BMPs
of human periosteum. Real-time polymerase chain reaction was performed
for BMP-2,-4,-6,-7
Giant cell tumors of bone (GCTs) are locally aggressive tumors with recurrence potential that represent up to 10% of primary tumors of the bone. GCTs pathogenesis is driven by neoplastic mononuclear stromal cells that overexpress receptor activator of nuclear factor kappa-B/ligand (RANKL). Treatment with specific anti-RANKL antibody (denosumab) was recently introduced, used either as a neo-adjuvant in resectable tumors or as a stand-alone treatment in unresectable tumors. While denosumab has been increasingly used, a percentage of patients do not improve after treatment. Here, we aim to determine molecular and histological patterns that would help predicting GCTs response to denosumab to improve personalized treatment. Nine pre-treatment biopsies of patients with spinal GCT were collected at 2 centres. In 4 patients denosumab was used as a neo-adjuvant, 3 as a stand-alone and 2 received denosumab as adjuvant treatment. Clinical data was extracted retrospectively. Total mRNA was extracted by using a formalin-fixed paraffin-embedded extraction kit and we determined the transcript profile of 730 immune-oncology related genes by using the Pan Cancer Immune Profiling panel (Nanostring). The
Periprosthetic joint infection (PJI) is a potentially devastating complication of joint replacement surgery. Osteocytes comprise 90–95% of all cells in hard bone tissue, are long-lived and are becoming increasingly recognised as a critical cell type in the regulation of bone and systemic physiology. The purpose of this study was to examine role of these cells in PJI pathophysiology and aetiology, with the rationale that their involvement could contribute to the difficulty in detecting and clearing PJI. This study examined the ability of human osteocytes to become infected by Staphylococcus aureus and the responses of both the host cell and pathogen in this scenario. Several S. aureus (MRSA) strains were tested for their ability to infect human primary osteocyte-like cells in vitro and human bone samples ex vivo. Bone biopsies were retrieved from patients undergoing revision total hip arthroplasty for either aseptic loosening associated with osteolysis, or for PJI. Retrieved bacterial colony number from cell lysates and colony morphology were determined.
Adolescent idiopathic scoliosis (AIS) is a poorly understood progressive curvature of the spine. The 3-dimmensionnal spinal deformation brings abnormal biomechanical stresses on the load-bearing organs. We have recently reported for the first time the presence of facet joint cartilage degeneration comparable to age-related osteoarthritis in scoliotic adolescents. To better understand the degenerative mechanisms and explore new therapeutic possibilities, we focused on Toll-like receptors (TLRs) which are germline-encoded pattern recognition receptors that recognize pathogens and endogenous proteins such as fragmented extracellular matrix components (alarmins) present in intervertebral discs (IVD) and articular cartilage. Once activated, they regulate the production pro-inflammatory cytokines, proteases and neurotrophins which can lead to matrix catabolism, inflammation and potentially pain. These mechanisms have however not been studied in the context of AIS or facet joints. Facet joints of AIS patients undergoing corrective surgery and of cadaveric donors (non-scoliotic) were collected from consenting patients or organ donors with ethical approval. Cartilage biopsies and chondrocytes were isolated using 3mm biopsy punches and collagenase type 2 digestion respectively. qPCR was used to assess
Aim. In vivo biofilm models play major role to study biofilm development, morphology, and regulatory molecules involve in biofilm. Due to ethical restrictions, the use mammalian models are replaced with other alternative models in basic research. Recently, we have developed insect infection model G. mellonella larvae to study implant associated biofilm infections. This model organism is easy to handle, cheap and ethical restriction free and could be used for the high through put screening of antimicrobial compounds to treat biofilm. To promote the use of this model in basic research we aimed to validate this based on the typical biofilm features such as less susceptible to the antibiotics, complexity of the biofilm structure and
Tenomodulin (Tnmd) is the best known mature tendon factor for tendon and ligament tissues with reported important regulatory roles1. In addition, Tnmd C-terminal cysteine-rich domain has been descibed to exert anti-angiogenic functions in in vitro angiogenic assays as well as in vivo models of tendon injury and age-associated cardiac valve diseases1, 2. Interestingly, Tnmd expresson in the intervertebral disc (IVD), which is normally avascular tissue, has been also suggested3. Hence, the purpose of this study was first, to map the exact expression pattern of Tnmd during IVD development and aging and second, by implementing Tnmd-knockout mouse model, to examine if Tnmd plays a role in IVD homeostasis. Histological analyses (hematoxylin/eosin, Safranin O, CD31 for endothelium, TUNEL for apoptosis and type X collagen and Runx2 for hypetrophy) were performed on Tnmd −/−, Tnmd −/− and chondromodulin I Chmd 1 −/− (Tnmd only homolog) double knockout and wild type mice WT (n = three to five) to examine IVD degeneration. Real time PCR was implemented to explore
Osteoarthritis (OA) is a chronic degenerative joint disorder that affects millions of people. There are currently no therapies that reverse or repair cartilage degradation in OA patients. Link N (DHLSDNYTLDHDRAIH) is a naturally occurring peptide that has been shown to increase both collagen and proteoglycan synthesis in chondrocytes and intervertebral disc cells [1,2]. Recent evidence indicates that Link N activates Smad1/5 signaling in cultured rabbit IVD cells presumably by interacting with the bone morphogenetic protein (BMP) type II receptor [3], however, whether a similar mechanism exists in chondrocytes remains unknown. In this study we determined whether Link N can stimulate matrix production and reverse degradation of human OA cartilage under inflammatory conditions. OA cartilage was obtained from donors undergoing total knee arthroplasty with informed consent. OA cartilage/bone explants and OA chondrocytes were prepared from each donor. Cells were prepared in alginate beads (2×106 cells/mL) for
The detailed biomechanical mechanism of annulus fibrosus under abnormal loading is still ambiguous, especially at the micro and nano scales. This study aims to characterize the alterations of modulus at the nano scale of individual collagen fibrils in annulus fibrosus after in-situ immobilization, and the corresponding micro-biomechanics of annulus fibrosus. An immobilization model was used on the rat tail with an external fixation device. Twenty one fully grown 12-week-old male Sprague-Dawley rats were used in this study. The rats were assigned to one of three groups randomly. One group was selected to be the baseline control group with intact intervertebral discs (n=7). In the other two groups, the vertebrae were immobilized with an external fixation device that fixed four caudal vertebrae (C7-C10) for 4 and 8 weeks, respectively. Four K-wires were fixed in parallel using two aluminum alloy cuboids which do not compress or stretch the target discs. The immobilized discs were harvested and then stained with hematoxylin/eosin, scanned using atomic force microscopy to obtain the modulus at both nano and micro scales, and analyzed the
Polyethylene wear-debris induced inflammatory osteolysis is known as the main cause of aseptic loosening and long term revision total hip arthroplasty. Although recent reports suggest that antioxidant impregnated ultra-high molecular weight polyethylene (UHMWPE) wear-debris have reduce the osteolytic potential in vivo when compared to virgin UHMWPE, little is known about if and/or how PE rate of oxidation affects osteolysis in vivo. We hypothesized that oxidized UHMWPE particles would cause more inflammatory osteolysis in a murine calvarial bone model when compared to virgin UHMWPE. Male C57BL/6 eight weeks old received equal amount of particulate debris overlaying the calvarium of (n=12/group): sham treatment (no particles), 2mg (6,75×107 particles/mg) of endotoxin-free UHMWPE particles (PE) or of endotoxin-free highly oxidized-UHMWPE (OX) particles. In vivo osteolysis was assessed using high resolution micro-CT and inflammation with L-012 probe dependent luminescence. At day 10, calvarial bone was examined using high resolution micro-CT, histomorphometric, immunohistochemistry analyses and qRT-PCR to assess OPG, RANK, RANK-L, IL-10, IL-4, IL-1b and TRAP
The poor prognosis of patients with soft-tissue sarcoma as not changed in the past several decades, highlighting the necessity for new therapeutic approaches. T-cell based immunotherapies are a promising alternative to traditional cancer treatments due to their ability to target only malignant cells, leaving benign cells unharmed. The development of successful immunotherapy requires the identification and characterization of targetable immunogenic tumor antigens. Cancer-testis antigens (CTA) are a group of highly immunogenic tumor-associated proteins that have emerged as potential targets for CD8+ T-cell recognition. In addition to identifying a targetable antigen, it is crucial to understand the tumor immune microenvironment. The level of immune infiltration and mechanisms of immune suppression within the tumor play important roles in the outcome of immunotherapy. The goal of this study is to identify targetable immunogenic antigens for T-cell based immunotherapy and to characterize the tumor immune microenvironment in human dedifferentiated liposarcoma (DDLS) by Nanostring and IHC. To assess the complexity of the human DDLS tumor immune microenvironment and to identify target antigens we used the nCounter NanoString platform to generate a
Introduction. Improvements in material properties of total joint prostheses and methods of fixation mean that arthroplasty is the most effective means of restoring mobility in osteoarthritic patients. Aseptic loosening is the major cause of long-term failure of prostheses. Cobalt particles may act directly on osteoblasts, decreasing bone formation and potentially playing a role in osteolysis and aseptic loosening. Objectives. To assess