The objectives of this study were to (1) determine the distribution and synthesis of pericellular matrix (PCM) molecules (collagen Ⅵ, collagen Ⅳ and laminin) in rat temporomandibular joint (TMJ) and (2) investigate the effects of PCM molecules on chondrocytes against inflammation in osteoarthritis. Four zones (fibrous, proliferating, mature and hypertrophic) of condylar cartilage and three bands (anterior, intermediate and posterior) of disc were analysed by immunohistochemistry for the presence of PCM molecules in rat TMJs. Isolated chondrocytes were pre-treated with PCM molecules before being subjected to interleukin (IL)-1β treatment to stimulate inflammation. The responses of the chondrocytes were analysed using gene expression, nitric oxide release and matrix metalloproteinase (MMP)-13 production measures. Histomorphometric analyses revealed that the highest areal deposition of collagen Ⅵ (67.4%), collagen Ⅳ (45.7%) and laminin (52.4%) was in the proliferating zone of TMJ condylar cartilage. No significant difference in the distribution of PCM molecules was noted among the three bands of the TMJ disc. All three PCM molecules were expressed intracellularly by chondrocytes cultured in the monolayer. Among the PCM molecules, pre-treatment with collagen Ⅵ enhanced cellular proliferation, ameliorated IL-1β-induced MMP-3, MMP-9, MMP-13 and inducible nitric oxide synthase gene expression, and attenuated the downregulation of cartilage matrix genes, including collagen Ⅰ, aggrecan and cartilage oligomeric matrix protein (COMP). Concurrently, collagen Ⅵ pretreatment inhibited nitric oxide and MMP-13 production. Our study demonstrates for the first time the distribution and role of PCM molecules, particularly collagen Ⅵ, in the protection of chondrocytes against inflammation.

The Academy of Medicine (AMS) and Ministry of Health (MOH) have developed the clinical practice guidelines on Assessment and Management of Infertility at Primary Healthcare Level to provide doctors and patients in Singapore with evidence-based treatment for infertility. This article reproduces the introduction and executive summary (with recommendations from the guidelines) from the AMS-MOH clinical practice guidelines on Assessment and Management of Infertility at Primary Healthcare Level, for the information of SMJ readers. Chapters and page numbers mentioned in the reproduced extract refer to the full text of the guidelines, which are available from the Ministry of Health website: http://www.moh.gov.sg/content/moh_web/healthprofessionalsportal/doctors/guidelines/cpg_medical/2013/cpgmed_infertility.html. The recommendations should be used with reference to the full text of the guidelines. Following this article are multiple choice questions based on the full text of the guidelines.
Evidence-Based Medicine ; Female ; Guidelines as Topic ; Humans ; Infertility ; diagnosis ; therapy ; Male ; Practice Guidelines as Topic ; Primary Health Care ; methods ; standards ; Public Health ; standards ; Singapore