Summary Matrix metalloproteinases (MMPs) may be important in the destruction of cartilage seen in equine osteoarthritis and may be detectable in synovial fluid. Synovial fluids were obtained from normal equine joints and from joints of horses with aseptic and septic joint diseases. The total MMP gelatinase enzyme activities were measured by gelatin zymography and image analysis of the gels. The bioactivity of gelatinase in synovial fluid was determined by a gelatin degradation ELISA. Potential MMP‐2 & MMP‐9 monomer enzyme activities were significantly elevated in both septic and aseptic joint disease synovial fluids in comparison to fluids from normal joints. The dimer form of MMP‐9 enzyme activity was significantly elevated in fluids from septic joint disease cases in comparison to fluids from normal joints, but not fluids from horses with aseptic joint diseases. MMP‐9 monomer and dimer levels in synovial fluids correlated with the synovial fluid white blood cell count. Using the gelatin degradation ELISA to measure net active gelatinases, significant increases in gelatinase bioactivities were seen in synovial fluids from both aseptic and septic joint disease cases. The enzymes in equine joint diseases were present in a bioactive form, in that they were present in the activated form and present in excess of inhibitors, and could therefore be important in the degradation of articular cartilage in joint disease.

Summary The cellular production by resident articular cells and infiltrating inflammatory cells of the gelatinase matrix metalloproteinases (MMP) was investigated by tissue culture methods and analysis of cell supernatants by gelatin zymography. Peripheral blood neutrophils in short term culture produced MMP‐9, as did peripheral blood monocytes in culture. Isolated articular chondrocytes in monolayer culture produced both MMP‐2 and MMP‐9, although articular cartilage maintained as explant culture produced MMP‐2 alone. Synovial fibroblasts grown in monolayer culture produced MMP‐2 alone, although synovial membrane in explant culture produced both MMP‐2 and the active form of MMP‐2. Lysis of blood polymorph neutrophils produced large quantities of MMP‐9, but lysis of blood monocytes, synovial fibroblasts and articular chondrocytes produced little enzyme indicating that, unlike the other cell types, polymorph neutrophils store MMPs intracellularly. Equine MMP‐2 was purified from synovial fibroblast cell culture supernatant, and equine MMP‐9 from polymorph neutrophil cell culture supernatant, by gelatin‐sepharose affinity chromatography. The 2 enzymes were identified from their molecular weights and by their respective N‐terminal amino acid sequences which showed homology with the enzymes from other species. The demonstration that invasive cells and resident articular cells can produce enzymes which are capable of digestion of certain component molecules of the articular cartilage matrix, shows that therapeutic targeting of these enzymes could be a valid proposition in the prevention of cartilage destruction in osteoarthritis.

No abstract

An epizootic in farmed, market-size rainbow trout in Spain caused by a strain of Carnobacterium piscicola of unusual virulence. Diseases ofAquatic Organisms 17,87-99 UBELS, J. L. & EDELHAUSER, H. F. (1987) Effects of corneal epithelial abrasion on corneal transparency, aqueous humor composition, and lens of fish.

Since the first report of bovine digital dermatitis (DD) in 1974, there is a large body of the literature published; however, effective prevention and control of the disease remain elusive. Although many aspects of the pathogenesis of DD have been investigated, even some of the most basic questions such as the aetiology of this disease remain under debate. Treponema spp. have been strongly associated with DD lesions and occur in abundance in advanced lesions; however, efforts to induce disease with pure cultures of these organisms have been largely underwhelming and inconsistent. Furthermore, although the disease has been presented for several decades, there is limited scientific evidence regarding effective treatment of DD. Apparent discrepancies between effectiveness in vitro and in vivo have challenged the scientific community to identify new potential treatment options. With no treatment resulting in a 100% cure rate, the current expectation is manageable control, but prospects for the eradication of the disease are unlikely using current approaches. In order to develop more effective approaches to control DD on-farm, there is a critical need for a deeper understanding regarding the causation, ecology, transmission and treatment of this disease. In this article, we attempt to provide insights into specific research needs related to DD in order to assist the industry, researchers, pharmaceutical companies and research sponsors with decision-making and identified research gaps.