The increased leptin levels in SF point toward a local effect of leptin in articular cartilage, while the observed intrajoint differences of leptin and Ob-Rb mRNA expression may be related to the grade of cartilage destruction. The observed production of IL-1beta, MMP-9 and MMP-13 by chondrocytes after leptin treatment indicates a pro-inflammatory and catabolic role of leptin on cartilage metabolism. Furthermore, the observed correlation of leptin's mRNA expression with BMI suggests that leptin may be a metabolic link between obesity and OA.
We have used RT-PCR and GFP-mediated uorescence to analyse the regulation of PrfA-dependent virulence genes of Listeria monocytogenes during proliferation in mammalian host cells. Our data show that most of the PrfA-regulated virulence genes are more eciently expressed, as measured by transcript levels, when L. monocytogenes is grown in macrophages and macrophage-like cells rather than in epithelial cells, hepatocytes or endothelial cells. The promoters for hly and plcA are predominantly activated within the phagosomal compartment, while those for actA and inlC are predominantly activated in the host cell cytosol. Expression of actA and plcB precedes that of inlC after infection of epithelial cells and macrophages. Little transcription of inlA or inlB is observed in epithelial cells and there is only slightly more in macrophages. In both cell types the level of transcription of the inlAB operon is lower than is seen under extracellular growth conditions in rich media, which is compatible with the assumption that InlA and InlB are not required during intracellular growth of the bacteria. Activation of the PrfA-independent iap promoter is also low during intracellular growth, although the gene product (p60) is required for cell viability. The levels of the PrfA-dependent virulence gene transcripts do not correlate with the amount of prfA transcript present, which is low under all intracellular conditions analysed, suggesting that the prfA transcript is either highly unstable in bacteria that are growing intracellularly, or that the small amount of PrfA produced is highly activated by additional component(s).
Background The ''terrible triad'' of the elbow is a complex injury that can lead to pain, stiffness, and posttraumatic arthritis if not appropriately treated. The primary goal of surgery for these injuries is to restore stability of the joint sufficient to permit early motion. Although most reports recommend repair and/or replacement of all coronoid and radial head fractures when possible, a recent cadaveric study demonstrated that type II coronoid fractures are stable unless the radial head is removed and not replaced. Questions/purposes The purposes of this study were to determine the (1) range of motion; (2) clinical scores using the Disabilities of the Arm, Shoulder and Hand (DASH) and the Broberg-Morrey questionnaires; and (3) rate of arthritic changes, heterotopic ossification (HO), or elbow instability postoperatively in patients whose terrible triad injuries of the elbow included Reagan-Morrey type I or II coronoid fractures that were treated without fixation. Methods Between April 2008 and December 2010, 14 consecutive patients were treated for acute terrible triad injuries that included two Regan-Morrey type I and 12 Regan-Morrey type II coronoid fractures. Based on the senior author's (DGS) clinical experience that coronoid fractures classified as such do not require fixation to restore intraoperative stability to the posterolaterally dislocated elbow, all injuries were treated by the senior author with a surgical protocol that included radial head repair or prosthetic replacement and repair of the lateral ulnar collateral ligament (LUCL) followed by intraoperative fluoroscopic examination through a range of 20°to 130°of elbow flexion to confirm concentric reduction of the ulnohumeral joint. Using this protocol, intraoperative stability was confirmed in all cases without any attempt at coronoid or anterior capsular repair. Repair of the medial collateral ligament or application of external fixation was not performed in any case. All patients were available for followup at a minimum of 24 months (mean, 41 months; range, 24-56 months). The mean patient age was 52 years (range, 32-58 years). At the followup all patients were evaluated clinically and radiographically by the senior author. Outcome measures included elbow range of motion, forearm rotation, elbow stability, and radiographic evidence of HO or arthritic changes using the Broberg and Morrey scale. Elbow instability was defined as clinical or radiographic evidence of recurrent ulnohumeral dislocation or subluxation at final followup. Clinical outcomes were assessed with the patient-reported DASH questionnaire and the physician-administered Broberg-Morrey elbow rating system. Results The mean arc of ulnohumeral motion at final followup was 123°(range, 75°-140°) and mean forearm Each author certifies that he or she, or a member of his or her immediate family, has no funding or commercial associations (eg, consultancies, stock ownership, equity interest, patent/licensing arrangements, etc) that might pose a conflict of interest in connectio...
The aim of this study is to establish a new experimental model of hematogenous implant-related infection (IRI) by a communityacquired methicillin-resistant S. aureus (CA-MRSA) strain. Cylindrical porous tantalum intramedullary implants were inserted in the proximal right tibia of 30 male white rabbits after administration of antibiotic prophylaxis. Four weeks later and without antibiotic prophylaxis, 20 animals received 1 ml of inoculum of two different concentrations (study groups A and B) of CA-MRSA strain through an ipsilatelar femoral artery catheter. The remaining 10 received normal saline instead (control group C). Surviving animals were sacrificed 4 weeks later. Sterile bone, bone marrow biopsies, and implants were harvested for culture and histological evaluation. Ten animals receiving 5 Â 10 8 cfu/ml (group A) died within 48-72 h due to septic shock. Blood cultures were positive; histology demonstrated acute infection. Ten animals received bacterial load of 3 Â 10 8 cfu/ml (group B) and all survived; two had negative Gram-stain and cultures but PCR and RT-PCR results demonstrated the viability of the microorganisms, while periprosthetic osteolysis and histological evaluation indicated subacute osteomyelitis; eight animals established periprosthetic infection, osteomyelitis, and septic arthritis documented by positive Gram-stain, cultures, subperiosteal reaction, and chronic infection on histology. Control group specimens demonstrated no signs of infection. Histopathological semiquantitative scoring was used to compare the three groups. Comparison of groups A and B with control group and between group A and B showed statistically significant difference ( p < 0.05) in all parameters except for periosteal reaction between groups B and C ( p ¼ 0.354). This novel, reproducible experimental model will facilitate the study of hematogenous CA-MRSA IRIs. ß
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