Characterization Of Osteoarthritis Research Articles

Characterization of Osteoarthritis in a Medial Meniscectomy-Induced Animal Model Using Contrast-Enhanced X-ray Microtomography.

The aim of this study was to clarify degradation characteristics in each tissue of the knee complex of a medial meniscectomy (MMx)-induced knee osteoarthritis (KOA) animal model using classical methods and an alternative comprehensive evaluation method called contrast-enhanced X-ray micro-computed tomography (CEX-μCT), which was developed in the study. Surgical MMx was performed in the right knee joints of five male Wistar rats to induce KOA. At four weeks post-surgery, the synovitis was evaluated using quantitative polymerase chain reaction (qPCR). Degradations of the articular cartilage of the tibial plateau were evaluated using classical methods and CEX-μCT. Evaluation of the synovitis demonstrated significantly increased expression levels of inflammation-associated marker genes in MMx-treated knees compared with those in sham-treated knees. Evaluation of the articular cartilage using classical methods showed that MMx fully induced degradation of the cartilage. Evaluation using CEX-μCT showed that local areas of the medial cartilage of the tibial plateau were significantly reduced in MMx-treated knees compared with those in sham-treated knees. On the other hand, total cartilage volumes were significantly increased in MMx-treated knees. On the basis of the findings of this study, the method could be relevant to study new treatments in KOA research.

Characterization of osteoarthritis in patients with diabetes mellitus type 2

Characterization of osteoarthritis in patients with diabetes mellitus type 2

Spatial variations in magnetic resonance-based diffusion of articular cartilage in knee osteoarthritis

PurposeTo evaluate a pulse sequence combining stimulated echo diffusion preparation with a 3D segmented spoiled gradient echo (SPGR) acquisition for diffusion tensor imaging (DTI) of knee cartilage in healthy and osteoarthritis (OA) populations for early diagnosis and characterization of OA. MethodsDiffusion-weighted images of 40 subjects (20 healthy, 20 OA) at baseline and 20 subjects (10 healthy, 10 OA) at one year were obtained. The subjects were classified according to Kellgren Lawrence (KL) and whole organ magnetic resonance imaging scoring (WORMS) method acquired at 3T. Cartilage full thickness and laminar mean diffusivity (MD) and fractional anisotropy (FA) values were quantified. The reproducibility of MD and FA values was assessed in five healthy human subjects based on test–retest scans. ResultsIn general, the full thickness MD values were higher in subjects with knee OA compared to healthy controls in both the baseline and follow up cohort. Laminar analysis MD and FA results were significantly different (p<0.05) between the bone-articular and articular layer with the articular layer having higher MD and lower FA value compared to the bone layer. The global reproducibility error was 6.5% for MD and 11.6% for FA. ConclusionThe diffusion-weighted stimulated echo-based sequence may be used as a valuable tool for early diagnosis and characterization of knee OA at 3T in the future.

Characterization of the cartilage DNA methylome in knee and hip osteoarthritis.

ObjectiveThe aim of this study was to characterize the genome-wide DNA methylation profile of chondrocytes from knee and hip cartilage obtained from patients with osteoarthritis (OA) and hip cartilage obtained from patients with femoral neck fracture, providing the first comparison of DNA methylation between OA and non-OA hip cartilage, and between OA hip and OA knee cartilage.MethodsThe study was performed using the Illumina Infinium HumanMethylation450 BeadChip array, which allows the annotation of ∼480,000 CpG sites. Genome-wide methylation was assessed in chondrocyte DNA extracted from 23 hip OA patients, 73 knee OA patients, and 21 healthy hip control patients with femoral neck fracture.ResultsAnalysis revealed that chondrocytes from the hip cartilage of OA patients and healthy controls have unique methylation profiles, with 5,322 differentially methylated loci (DMLs) identified between the 2 groups. In addition, a comparison between hip and knee OA chondrocytes revealed 5,547 DMLs between the 2 groups, including DMLs in several genes known to be involved in the pathogenesis of OA. Hip OA samples were found to cluster into 2 groups. A total of 15,239 DMLs were identified between the 2 clusters, with an enrichment of genes involved in inflammation and immunity. Similarly, we confirmed a previous report of knee OA samples that also clustered into 2 groups.ConclusionWe demonstrated that global DNA methylation using a high-density array can be a powerful tool in the characterization of OA at the molecular level. Identification of pathways enriched in DMLs between OA and OA-free cartilage highlight potential etiologic mechanisms that are involved in the initiation and/or progression of the disease and that could be therapeutically targeted.

Characterization of osteoarthritis in cats and meloxicam efficacy using objective chronic pain evaluation tools

This study aimed to characterize osteoarthritis (OA)-related chronic pain and disability in experimental cats with naturally occurring OA. Peak vertical ground reaction force (PVF), accelerometer-based motor activity (MA) and the von Frey anesthesiometer-induced paw withdrawal threshold were used to define OA and to test the efficacy of meloxicam. A diagnosis of OA was based on radiographic and orthopedic examinations. Cats with OA (n=39) and classified as non-OA (n=6) were used to assess the reliability and sensitivity of the parameters to assess OA over 3weeks while being administered placebo medication. A randomised parallel design study was then used to investigate the effects on OA of daily oral meloxicam treatment for 4weeks at different dose rates (0.025mg/kg, n=10mg/kg; 0.04mg/kg, n=10; 0.05mg/kg, n=9), compared to cats administered a placebo (n=10).The test–retest repeatability for each tool was good (intra-class correlation coefficient ⩾0.6). The PVF and the von Frey anesthesiometer-induced paw withdrawal threshold discriminated OA (P<0.05). Meloxicam did not add to the PVF improvement observed in placebo-treated cats during the treatment period (adj-P⩽0.01). The 0.025 and the 0.05mg/kg meloxicam-treated cats experienced a higher night-time (17:00–06:58h) MA intensity during the treatment period compared to the placebo period (adj-P=0.04, and 0.02, respectively) and this effect was not observed in the placebo group. The high allodynia rate observed in the 0.04mg/kg meloxicam-treated group may explain the lower responsiveness to the drug. The von Frey anesthesiometer-induced paw withdrawal threshold demonstrated no responsiveness to meloxicam. The results from this study indicated that daily oral meloxicam administration for 4weeks provided pain relief according to night-time MA.