Early-onset osteoarthritis of mouse temporomandibular joint induced by partial discectomy.

OBJECTIVE: The objective of this study is to characterize mouse temporomandibular joint (TMJ) following partial discectomy, since there is no documentation of whether or not partial discectomy can induce early-onset osteoarthritis (OA) in mouse TMJ. METHODS: Partial discs of TMJ in mice were removed by microsurgery. Histology was performed to characterize articular cartilages from the TMJ of mice. The morphology of the articular cartilages was evaluated using a modified Mankin scoring system. Immunohistostaining was carried out to examine the expression of discoidin domain receptor 2 (Ddr2), a type II collagen receptor, matrix metalloproteinase-13 (Mmp-13), and Mmp-derived type II collagen fragments in the articular cartilage of condyles from the mouse TMJ. RESULTS: Articular cartilage degeneration was seen in the mouse TMJ post-discectomy, including increased proteoglycan staining in the extracellular matrix at 4 weeks, the appearance of chondrocyte clusters at 8 weeks, reduced proteoglycan staining and fibrillation at 12 weeks and the loss of articular cartilage at 16 weeks. Increased immunostaining for Ddr2, Mmp-13, and Mmp-derived type II collagen fragments was detected. CONCLUSION: Results indicate that partial discectomy induces early-onset OA in mouse TMJ and that increased expression of Mmp-13, likely due to the elevated expression of Ddr2, may be one of the factors responsible for the early-onset OA in mouse TMJ.

[Ulcer perforating into the free peritoneum. Review of 70 cases]. / Ulcère perforé en péritoine libre. Revue de 70 cas.

We retrospectively studied a series of 70 patients admitted between 1977 and 1982 with an acute perforated ulcer. As compared to available data our patient's population is characterized by elevated mean age and by important delay between onset of symptoms and admission. Clinical diagnosis supported by plain X-rays and laboratory was confirmed in 91%. In one patient only, treatment was purely conservative; nine vagotomies, four gastrectomies and fifty-six suture plication were performed. Hospital stage was short (mean: 13,5 days) despite 37% morbidity. Mortality (10%) was close correlated with age and delay between onset of symptoms and treatment.