Abstract. (5R)-5-hydroxytriptolide (LLDT-8) extracts fromTripterygium have anti-inflammatory, antineoplastic and immunity adjustment functions. The present study used a collagen-induced arthritis (CIA) model to evaluate whether LLDT-8 prevents collagen-induced arthritis, and investigated the signaling underlying this. Male Sprague-Dawley rats were induced to generate CIA, mimicking rheumatoid arthritis (RA). The presence of arthritis was determined using RA progression scores. The inflammatory cytokines interleukin (IL)-1β, IL-6 and nuclear factor-κB were detected using enzyme-linked immunosorbent assay kits. Induced nitric oxide synthase (iNOS) and matrix metalloprotease (MMP)-13 protein expression were measured using western blot analysis. Lastly, reverse transcription-quantitative polymerase chain reaction was used to evaluate osteoprotegerin (OPG) and receptor activator of nuclear factor κB (RANK) gene expression. LLDT-8 improved RA progression scores and reduced the incidence and severity of CIA. Furthermore, LLDT-8 administration inhibited collagen-induced inflammation and iNOS protein expression in arthritic rats. The current data indicated that MMP-13 production was suppressed and OPG/RANKL expression was increased by LLDT-8 treatment in the arthritic rat. The present results suggest that LLDT-8 attenuates CIA through OPG/RANK/RANK ligand signaling in a rat model of RA. IntroductionRheumatoid arthritis (RA) is a chronic, systemic autoimmune disease that is characterized by erosive arthrosynovitis (1).The incidence of RA in females is more than that in males, at a ratio of 1:3 (2). The mortality rate of RA in worldwide populations varies from 0.01-0.05%, and prevalence rate is 0.18-1.07% (3). RA is also an impactful disease, resulting in labor loss and disability in China (2). According to US epidemiological investigation over the last 40 years, the difference in mortality rate between RA patients and the general population has increased (4). The risk of cognitive impairment for RA patients is higher than that of the general population (5). The etiology of RA is unclear. Previous studies suggest that RA is associated with genetic factors, infection, immunity and endocrine function (6,7).The main pathological characteristics of RA are hyperplasia of synovial cells and T cell accumulation during inflammation of synovial tissues, accompanied by pannus formation, followed by damage to the cartilage and bone (8). Finally, RA causes joint deformity and functional loss (9). These pathological changes may result from a combination of genetic mutations, activation of protooncogenes, lesions of synoviocytes, release of proinflammatory cytokines by inflammatory cells during infiltration of synovial tissues, chemotactic factors and enzymatic degradation of stromal proteins, amongst other factors (10). The etiology of RA is unclear, but it is universally believed to be a multifactorial disease, associated with genetic, environmental and infective factors (11). Autoimmunity may arise due to genetic factors, or as an ab...

BackgroundKnee valgus and varus morbidity is at the second top place in children lower limb deformity diseases. It may cause abnormal stress distribution. The magnitude and location of contact forces on tibia plateau during gait cycle have been indicated as markers for risk of osteoarthritis. So far, few studies reported the contact stress and force distribution on tibial plateau of valgus knee of children.MethodsTo estimate the contact stresses and forces on tibial plateau of an 8-year old obese boy with valgus knee and a 7-year old healthy boy, three-dimensional (3D) finite element (FE) models of their left knee joints were developed. The valgus knee model has 36,897 nodes and 1,65,106 elements, and the normal knee model has 78,278 nodes and 1,18,756 elements. Paired t test was used for the comparison between the results from the 3D FE analysis method and the results from traditional kinematic measurement methods.ResultsThe p value of paired t test is 0.12. Maximum stresses shifted to lateral plateau in knee valgus children while maximum stresses were on medial plateau in normal knee child at the first peak of vertical GRF of stance phase. The locations of contact centers on medial plateau changed 3.38 mm more than that on lateral plateau, while the locations of contact centers on medial plateau changed 1.22 mm less than that on lateral plateau for healthy child from the first peak to second peak of vertical GRF of stance phase.ConclusionsThe paired t test result shows that there is no significant difference between the two methods. The results of FE analysis method suggest that knee valgus malalignment could be the reason for abnormal knee load that may cause knee problems in obese children with valgus knee in the long-term. This study may help to understand biomechanical mechanism of valgus knees of obese children.

The measurements for gait cycle, cadence, step length, velocity, and number of steps with the GoPro camera are highly consistent with the measurements with the motion analysis system. The measurements for IDEEA3 are consistent with those for the GoPro camera. IDEEA3 can be effectively used in the gait measurement of LSS patients.

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