Differential arthritogenicity of Staphylococcus aureus strains isolated from biological samples

Background Staphylococcus aureus is the most common agent of septic arthritis that is a severe, rapidly progressive and destructive joint disease. Superantigens produced by S. aureus are considered the major arthritogenic factors. In this study, we compared the arthritogenic potential of five superantigen-producing staphylococcal strains. Methods Male C57BL/6 mice were intravenously infected with ATCC 19095 SEC+, N315 ST5 TSST-1+, S-70 TSST-1+, ATCC 51650 TSST-1+ and ATCC 13565 SEA+ strains. Clinical parameters as body weight, arthritis incidence and clinical score were daily evaluated. Joint histopathological analysis and spleen cytokine production were evaluated at the 14th day after infection. Results Weight loss was observed in all infected mice. ATCC 19095 SEC+, N315 ST5 TSST-1+ and S-70 TSST-1+ were arthritogenic, being the highest scores observed in ATCC 19095 SEC+ infected mice. Intermediate and lower clinical scores were observed in N315 ST5 TSST-1+ and S-70 TSST-1+ infected mice, respectively. The ATCC 13565 SEA+ strain caused death of 85% of the animals after 48 h. Arthritis triggered by the ATCC 19095 SEC+ strain was characterized by accentuated synovial hyperplasia, inflammation, pannus formation, cartilage destruction and bone erosion. Similar joint alterations were found in N315 ST5 TSST-1+ infected mice, however they were strikingly more discrete. Only minor synovial proliferation and inflammation were triggered by the S-70 TSST-1+ strain. The lowest levels of TNF-α, IL-6 and IL-17 production in response to S. aureus stimulation were found in cultures from mice infected with the less arthritogenic strains (S-70 TSST-1+ and ATCC 51650 TSST-1+). The highest production of IL-17 was detected in mice infected with the most arthritogenic strains (ATCC 19095 SEC+ and N315 ST5 TSST-1+). Conclusions Together these results demonstrated that S. aureus strains, isolated from biological samples, were able to induce a typical septic arthritis in mice. These results also suggest that the variable arthritogenicity of these strains was, at least in part, related to their differential ability to induce IL-17 production.

Comparative study by computed radiography, histology, and scanning electron microscopy of the articular cartilage of normal goats and in chronic infection with caprine arthritis-encephalitis virus

In the northeast of Brazil, caprine arthritis-encephalitis (CAE) is one of the key reasons for herd productivity decreasing that result in considerable economic losses. A comparative study was carried out using computed radiography (CR), histological analysis (HA), and scanning electronic microscopy (SEM) of the joints of CAE infected and normal goats. Humerus head surface of positive animals presented reduced joint space, increased bone density, and signs of degenerative joint disease (DJD). The carpal joint presented no morphological alterations in CR in any of the animals studied. Tarsus joint was the most affected, characterized by severe DJD, absence of joint space, increased periarticular soft tissue density, edema, and bone sclerosis. Histological analysis showed chronic tissue lesions, complete loss of the surface zone, absence of proteoglycans in the transition and radial zones and destruction of the cartilage surface in the CAE positive animals. Analysis by SEM showed ulcerated lesions with irregular and folded patterns on the joint surface that distinguished the limits between areas of normal and affected cartilage. The morphological study of the joints of normal and CAE positive goats deepened understanding of the alteration in the tissue bioarchitecture of the most affected joints. The SEM finding sustained previous histological reports, similar to those found for rheumatoid arthritis, suggesting that the goat infected with CAE can be considered as a potential model for research in this area.

Joint loading decreased by inexpensive and minimalist footwear in elderly women with knee osteoarthritis during stair descent

Objective Previous studies indicate that flexible footwear, which mimics the biomechanics of walking barefoot, results in decreased knee loads in patients with knee osteoarthritis (OA) during walking. However, the effect of flexible footwear on other activities of daily living, such as descending stairs, remains unclear. Our objective was to evaluate the influence of inexpensive and minimalist footwear (Moleca) on knee adduction moment (KAM) during stair descent of elderly women with and without knee OA. Methods. Thirty-four elderly women were equally divided into an OA group and a control group (CG). Stair descent was evaluated in barefoot condition, while wearing the Moleca, and while wearing heeled shoes. Kinematics and ground reaction forces were measured to calculate KAM by using inverse dynamics. Results. The OA group experienced a higher KAM during midstance under the barefoot condition (233.3%; P = 0.028), the Moleca (379.2%; P = 0.004), and heeled shoes (217.6%; P = 0.007). The OA group had a similar knee load during early, mid, and late stance with the Moleca compared with the barefoot condition. Heeled shoes increased the knee loads during the early-stance (versus barefoot [16.7%; P < 0.001] and versus the Moleca [15.5%; P < 0.001]), midstance (versus barefoot [8.6%; P = 0.014] and versus the Moleca [9.5%; P = 0.010]), and late-stance phase (versus barefoot [10.6%; P = 0.003] and versus the Moleca [9.2%; P < 0.001]). In the CG, the Moleca produced a knee load similar to the barefoot condition only during the early-stance phase. Conclusion. Besides the general foot protection, the inexpensive and minimalist footwear contributes to decreasing knee loads in elderly women with OA during stair descent. The loads are similar to the barefoot condition and effectively decreased when compared with heeled shoes.

Correlation between maxillofacial radiographic features and systemic severity as sickle cell disease severity predictor

This study was conducted to investigate the relationship among radiographic features observed on panoramic radiographs of sickle cell disease patients and analyze their relationship with history of systemic severity of the disease. Panoramic radiographs of 71 subjects with sickle cell disease were evaluated for the presence of the following radiographic bony alterations: radiopaque areas, increased spacing of bony trabeculae, horizontal arrangement of bony trabeculae and corticalization of mandibular canal. History of clinical systemic severity was assessed through direct questioning about the frequency of vaso-occlusive crisis, history of stroke, clinical jaundice, femur head necrosis, and leg ulceration. Chi-square or Fisher's exact test were applied in order to analyze possible associations between radiographic features and history of complications, with < 0.05 significance level. Increased spacing of bony trabeculae was statistically associated with absence of corticalization of mandibular canal ( < 0.01) and horizontal arrangement of bony trabeculae ( = 0.04). Statistically significant associations were demonstrated between history of clinical jaundice and presence of increased spacing of bony trabeculae ( = 0.02) and between history of stroke and presence of horizontal arrangement of bony trabeculae ( = 0.04). Based on the results of the current study, maxillofacial radiographic features may be associated with clinical parameters of systemic complications in sickle cell disease patients. The relationship between radiographic features and history of complications associated with clinical severity of sickle cell disease has not been demonstrated in the literature. Acknowledgment of such possible association may help establish prognosis and influence clinical treatment of systemic and oral complications.

Determinants of discordance in patients' and physicians' rating of rheumatoid arthritis disease activity

Objective To assess the determinants of patients' (PTGL) and physicians' (MDGL) global assessment of rheumatoid arthritis (RA) activity and factors associated with discordance among them. Methods. A total of 7,028 patients in the Quantitative Standard Monitoring of Patients with RA study had PTGL and MDGL assessed at the same clinic visit on a 0-10-cm visual analog scale (VAS). Three patient groups were defined: concordant rating group (PTGL and MDGL within >= 2 cm), higher patient rating group (PTGL exceeding MDGL by > 2 cm), and lower patient rating group (PTGL less than MDGL by > 2 cm). Multivariable regression analysis was used to identify determinants of PTGL and MDGL and their discordance. Results. The mean +/- SD VAS scores for PTGL and MDGL were 4.01 +/- 2.70 and 2.91 +/- 2.37, respectively. Pain was overwhelmingly the single most important determinant of PTGL, followed by fatigue. In contrast, MDGL was most influenced by swollen joint count (SJC), followed by erythrocyte sedimentation rate (ESR) and tender joint count (TJC). A total of 4,454 (63.4%), 2,106 (30%), and 468 (6.6%) patients were in the concordant, higher, and lower patient rating groups, respectively. Odds of higher patient rating increased with higher pain, fatigue, psychological distress, age, and morning stiffness, and decreased with higher SJC, TJC, and ESR. Lower patient rating odds increased with higher SJC, TJC, and ESR, and decreased with lower fatigue levels. Conclusion. Nearly 36% of patients had discordance in RA activity assessment from their physicians. Sensitivity to the "disease experience" of patients, particularly pain and fatigue, is warranted for effective care of RA.

Comparison between innominate osteotomy and arthrodistraction as a primary treatment for Legg-Calve-Perthes disease: a prospective controlled trial

Legg-Calv,-Perthes (LCP) disease is currently managed by mechanical containment of the femoral head in the hip socket. As evidence suggests that hip distraction may offer a new treatment strategy, we used arthrodistraction as a primary treatment for active forms of LCP disease and prospectively compared the results with the Salter innominate osteotomy. A total of 54 children, six years or older of both genders with severe forms of LCP disease in the stages of necrosis or revascularisation, were enrolled. Patients were submitted to either Salter innominate osteotomy (n = 28) or hip arthrodistraction (n = 26). Final radiographs were used to evaluate the Mose index, Wiberg angle, extrusion index and the Stulberg et al. classification. There were no significant differences in gender, age, lateral pillar classification and average follow-up time between the two groups. The osteotomy group progressed without major complications, but children in the joint distraction group experienced episodes of pin tract pain and infection, leading to the early removal of the external device in one case. Two patients developed joint stiffness, treated by physiotherapy or manipulation, and one child developed subluxation of the femoral head. The average time in distraction was 4.44 months (2.53-7.23 months). In the final evaluation the osteotomy group showed better containment of the femoral head. The Mose index and the Stulberg et al. classification were statistically similar between the two groups. Despite similar final radiological results, arthrodistraction was associated with a higher morbidity. Consequently, we do not recommend hip distraction as a primary treatment for the early stages of LCP disease.