Osteoarthritis of the knee and glucosamine: a commentary

in Osteoporosis International (2006, March), 17(Suppl.1), 111

Osteoarthritis, magnetic resonance imaging, and biochemical markers: a one year prospective study

in Annals of the Rheumatic Diseases (2006), 65(8), 1050-1054

Objective: To investigate the relation between biochemical markers of bone, cartilage, and synovial remodelling and the structural progression of knee osteoarthritis. Methods: 62 patients of both sexes ... [more ▼]

Objective: To investigate the relation between biochemical markers of bone, cartilage, and synovial remodelling and the structural progression of knee osteoarthritis. Methods: 62 patients of both sexes with knee osteoarthritis were followed prospectively for one year. From magnetic resonance imaging ( MRI), done at baseline and after one year, the volume and thickness of cartilage of the femur, the medial tibia, and the lateral tibia were assessed. A whole organ magnetic resonance imaging score ( WORMS) of the knee was calculated for each patient at baseline and at the one year visits. This score consists in a validated, semiquantitative scoring system for whole organ assessment of the knee in osteoarthritis using MRI. Biochemical markers ( serum hyaluronic acid, osteocalcin, cartilage glycoprotein 39 ( YKL-40), cartilage oligomeric matrix protein ( COMP), and C-telopeptide of type I collagen ( CTX-I), and urine C-telopeptide of type II collagen ( CTX-II)) were measured at baseline and after three months. Results: Baseline markers were not correlated with one year changes observed in cartilage volume and thickness. However, an increase in CTX-II after three months was significantly correlated with a one year decrease in mean thickness of medial tibial and lateral tibial cartilage. Patients in the highest quartile of three month changes in CTX-II experienced a mean loss of 0.07 ( 0.08) mm of their medial thickness, compared with a mean increase of 0.05 ( 0.19) mm for patients in the lowest quartile ( p = 0.04) Multiple regression analysis showed that high baseline levels of hyaluronic acid are predictive of a worsening in WORMS ( p = 0.004). Conclusions: These results suggest that a single measurement of serum hyaluronic acid or short term changes in urine CTX-II could identify patients at greatest risk of progression of osteoarthritis. [less ▲]

Osteoblast-related transcription factors Runx2 (Cbfa1/AML3) and MSX2 mediate the expression of bone sialoprotein in human metastatic breast cancer cells

in Cancer Research (2003), 63(10), 2631-2637

Human breast cancers are known to preferentially metastasize to skeletal sites, however, the mechanisms that mediate the skeletal preference (orthotropism) of specific types of cancers remains poorly ... [more ▼]

Human breast cancers are known to preferentially metastasize to skeletal sites, however, the mechanisms that mediate the skeletal preference (orthotropism) of specific types of cancers remains poorly understood. There is a significant clinical correlation between the expression of bone sialoprotein (BSP) and skeletal metastasis of breast cancers. Our laboratory, as well as others, have proposed the concept that skeletal selective metastasis and associated disease may be attributable to a mimicry of skeletal cellular phenotypes by metastasizing cancer cells. We hypothesize that breast cancer cell expression of phenotypic properties of skeletal cell types, including BSP as one component of that phenotype, is the result of ectopic expression or activity of one or more central transcriptional regulators of bone cell gene expression. To test this hypothesis, we examined the molecular mechanisms that regulate bsp expression in human breast cancer cell lines with previously characterized metastatic potentials. Our results demonstrate that the majority of the distal bsp promoter sequences act to repress BSP expression in cancer cells and that most of the promoter activity resides in the proximal -110 by of the bsp promoter. In this region, we identified a putative Runx binding element providing a basis for a mechanism for skeletal gene activation. Our results demonstrate that Runx2 is ectopically expressed in breast cancer cells and that one isoform of Runx2 can activate bsp expression in these cells. In addition, we observe that bsp expression is additionally regulated by the homeodomain factor Msx2, another regulator of osteoblast-associated genes. Thus, this is the first report of osteoblast-related transcription factors being expressed in human breast cancer cells and provides a component of a mechanism that may explain the osteoblastic phenotype of human breast cancer cells that preferentially metastasize to bone. [less ▲]

L'ostéoblaste : une cellule sous pression

Scientific conference (2008)

Les ostéoblastes arthrosiques inhibent la synthèse d’agrécane et stimulent la production de métalloprotéases par les chondrocytes humains

in Revue du Rhumatisme (2004), 71(10-11), 917

Les ostéoblastes des zones sclérosées de l’os sous-chondral arthrosique expriment moins de connexine-43 : une explication possible à la diminution de la sensibilité mécanique de ces cellules

Conference (2011)

Osteochondral plate angiogenesis: A new treatment target in osteoarthritis.

in Joint Bone Spine (2011), 78

Healthy adult joint cartilage contains neither blood vessels nor nerves. Osteoarthritic cartilage, in contrast, may be invaded by blood vessels from the subchondral bone. The mechanisms underlying ... [more ▼]

Healthy adult joint cartilage contains neither blood vessels nor nerves. Osteoarthritic cartilage, in contrast, may be invaded by blood vessels from the subchondral bone. The mechanisms underlying cartilage angiogenesis in osteoarthritis are unclear but may involve hypertrophic chondrocyte differentiation. Active research is under way to identify the factors involved in cartilage angiogenesis. Here, we discuss the pathophysiological mechanisms of osteoarthritic cartilage angiogenesis based on evidence from a systematic literature review of articles retrieved via PubMed and ISI Web of Knowledge. Our conclusions suggest new research perspectives and treatment options. [less ▲]

Osteochondrosis of the sacral bone in a mastiff dog

in Veterinary Record : Journal of the British Veterinary Association (1998)

Osteogenesis imperfecta

Conference (2008, January 25)

L’ostéomalacie : étiologie, clinique, physiopathologie et thérapeutique

in Le Monde Médical de la Femme (1996), 330(23), 18-21