OBJECTIVE: To determine whether gelatinase A (MMP-2) plays a significant role in the pathogenesis of Sjögren's syndrome (SS) with or without HTLV-I infection. METHODS: We examined 24 patients with SS (14 HTLV-I-seropositive and 8 HTLV-I-seronegative). Labial salivary gland tissue samples were analysed immunohistochemically using anti-MMP-2 monoclonal antibodies. RESULTS: In normal salivary glands, MMP-2 expression was not detected. All biopsy samples of 8 SS patients with HTLV-I-associated myelopathy (HAM) and 3 of 6 HTLV-I-seropositive SS patients without manifestation of HAM stained positively for MMP-2. However, the other samples were negative for MMP-2. CONCLUSION: Our study showed the MMP-2 expression in labial salivary glands of HTLV-I seropositive SS patients, especially in all SS patients with HAM. The presence of MMP-2 in the salivary glands of these patients suggests that it may play a role in cellular infiltration and destruction in salivary glands of SS.

Adult↗

PubMedDate not supplied

IL-1-mediated expression of membrane type matrix-metalloproteinase in rheumatoid osteoblasts.

OBJECTIVE: To determine whether the activation of metalloproteinases can be achieved by the interaction of the inflammatory cytokine, IL-1 beta, with rheumatoid osteoblasts. RESULTS: MMP-2 is not secreted by rheumatoid osteoblasts as a proenzyme; however, IL-1 beta stimulation induced the secretion of MMP-2 as an active form from rheumatoid osteoblasts. This MMP-2 activating activity was detected significantly in IL-1 beta-stimulated rheumatoid osteoblasts. In support of this result, IL-1 beta stimulation induced the expression of membrane type matrix-metalloproteinase (MT-MMP), a newly-identified MMP-2 specific activator, in rheumatoid osteoblasts. CONCLUSION: These results suggest that IL-1 beta induces MMP-2 activation in part by up-regulating MT-MMP expression and represents a new mechanism for cytokine-mediated articular destruction in RA.

Arthritis, Rheumatoid↗

PubMedDate not supplied

The metabolism of roxatidine acetate hydrochloride. Liberation of deuterium from the piperidine ring during hydroxylation.

The metabolism of roxatidine acetate hydrochloride (RA), a new histamine-2 receptor antagonist, was studied by GC/MS in rats and dogs in vivo. The co-administration of 14C-RA and RA-d10 labeled with deuterium in the piperidine ring expedited the isolation and identification of 15 urinary metabolites. The major metabolites in both animals were M-1, M-8, M-10, and M-11; M-4 could be found only in the rat. The aromatic and piperidine ring-hydroxylated metabolites were found in small amounts in both species. Following the administration of RA-d10 to rats and dogs, oxygenated metabolites on the piperidine ring, such as M-3 and M-4, were isolated and their analysis indicated the unexpected loss of three or four deuterium atoms from the ring. Also, first and second isotope effects were observed on the conversion rate in vivo and retention time in HPLC, respectively.

Administration, Oral↗