The Journal of Bone and Joint Surgery. British Volume
There are differences of opinion about the pathogenesis of Perthes' disease. All are agreed that it is due to ischaemia, but the cause of this and the size and number of infarctions are in dispute. Through the generosity of the contributors six whole femoral heads and core biopsies of five other cases have been studied radiographically and histologically. The findings ranged from an ischaemic arrest of ossification in the capital articular cartilage without infarction to multiple complete infarctions of the epiphysial bone.
The present study was aimed to establish the efficacy of Jeevaneeya Rasayana (JR), an ayurvedic polyherbal formulation, in adjuvant-induced arthritic (AIA) rat model with reference to mediators of inflammation. The methanolic (MJR), ethanolic (EJR), and water extracts (WJR) of JR were prepared and their anti-inflammatory activity in carrageenan-induced acute model was evaluated. MJR at a dose of 25 mg/kg showed significantly higher anti-inflammatory effect than EJR, WJR, and standard drug diclofenac. MJR also significantly decreased the paw edema in AIA rats.
Glucosamine represents one of the most commonly used drugs to treat osteoarthritis. However, mechanisms of its antiarthritic activities are still poorly understood. The present study identifies a novel mechanism of glucosamine-mediated anti-inflammatory activity. It is shown that both glucosamine and N-acetylglucosamine inhibit IL-1beta- and TNF-alpha-induced NO production in normal human articular chondrocytes.
BACKGROUND: Articular cartilage from patients with osteoarthritis is characterized by a decreased concentration and reduced size of glycosaminoglycans. Degeneration of the cartilage matrix is a multifactorial process, which is due in part to accelerated glycosaminoglycan catabolism. Recently, we have demonstrated that hexosaminidase represents the dominant glycosaminoglycan-degrading glycosidase released by chondrocytes into the extracellular compartment and is the dominant glycosidase in synovial fluid from patients with osteoarthritis.
Glucose serves as the major energy substrate and the main precursor for the synthesis of glycosaminoglycans in chondrocytes. Facilitated glucose transport represents the first rate-limiting step in glucose metabolism. This study examines molecular regulation of facilitated glucose transport in normal human articular chondrocytes by proinflammatory cytokines. IL-1beta and TNF-alpha, and to a lesser degree IL-6, accelerate facilitated glucose transport as measured by [(3)H]2-deoxyglucose uptake.
American Journal of Physiology. Endocrinology and Metabolism
Articular cartilage is an avascular, non-insulin-sensitive tissue that utilizes glucose as the main energy source, a precursor for glycosaminoglycan synthesis, and a regulator of gene expression. Facilitated glucose transport represents the first rate-limiting step in glucose metabolism. Previously, we demonstrated that glucose transport in chondrocytes is regulated by proinflammatory cytokines via upregulation of GLUT mRNA and protein expression.
OBJECTIVE: The mechanisms by which chondrocytes convert biomechanical signals into intracellular biochemical events are not well understood. In this study, we sought to determine the intracellular mechanisms of the magnitude-dependent actions of mechanical signals. METHODS: Chondrocytes isolated from rabbit articular cartilage were grown on flexible membranes. Cells were subjected to cyclic tensile strain (CTS) of various magnitudes in the presence or absence of interleukin-1beta (IL-1beta), which was used as a proinflammatory signal for designated time intervals.
Osteoarthritis and cartilage / OARS, Osteoarthritis Research Society
OBJECTIVES: Physical therapies are commonly used for limiting joint inflammation. To gain insight into their mechanisms of actions for optimal usage, we examined persistence of mechanical signals generated by cyclic tensile strain (CTS) in chondrocytes, in vitro. We hypothesized that mechanical signals induce anti-inflammatory and anabolic responses that are sustained over extended periods. METHODS: Articular chondrocytes obtained from rats were subjected to CTS for various time intervals followed by a period of rest, in the presence of interleukin-1beta (IL-1beta).
Complementary and alternative medicine products are increasingly being used for the treatment of autoimmune diseases. However, the mechanisms of action of these agents are not fully defined. Using the rat adjuvant arthritis (AA) model of human rheumatoid arthritis, we determined whether the ethanol extract of Celastrus aculeatus Merr. (Celastrus), a Chinese herb, can down-modulate the severity of AA, and also examined the Celastrus-induced changes in immune responses to the disease-related antigen mycobacterial heat-shock protein 65 (Bhsp65).
OBJECTIVE: Osteoarthritis (OA) of the knee causes significant morbidity and current medical treatment is limited to symptom relief, while therapies able to slow structural damage remain elusive. This study was undertaken to evaluate the effect of glucosamine and chondroitin sulfate (CS), alone or in combination, as well as celecoxib and placebo on progressive loss of joint space width (JSW) in patients with knee OA.