RESUMEN
Imaging findings of pneumonia are diverse, with frequent overlap between the various infectious etiologies of pneumonia, as well as various other disease conditions, including inflammatory conditions, vasculitis, and malignancy. In the appropriate clinical context, a number of imaging findings and the patterns that they form on imaging may provide clues that enable radiologists and clinicians to narrow the differential diagnostic considerations. Although a definite diagnosis can rarely be provided based on imaging findings alone, the combination of clinical, imaging, and laboratory findings are usually sufficient for accurate diagnosis and management decisions. It is important for radiologists to recognize the wide variety of imaging patterns that occur with different causes of pneumonia, and recognize specific imaging signs of certain infections when present, thereby facilitating diagnosis and optimizing patient care.
Asunto(s)
Neumonía , Vasculitis , Diagnóstico Diferencial , Humanos , Neumonía/diagnóstico por imagen , Tomografía Computarizada por Rayos XRESUMEN
This study was designed to characterize metabolic responses of meniscal tissue explants to injury and inflammation. We hypothesized that impact injury and interleukin (IL-1ß) stimulation of meniscal explants would result in significant increases in matrix metalloproteinase (MMP) activity and relevant cytokine production compared to controls. Mature canine meniscal explants (n = 9/group) were randomly assigned to: (i) IL-1ß (0.1 ng/ml) treated (IL); (ii) 25% strain (25); (iii) 75% strain (75); (iv) 25% + IL-1ß (25IL); (v) 75% + IL-1ß (75IL); or (vi) 0% + no IL-1ß control (NC). Explants were impacted at 100 mm/s to 0%, 25%, or 75% strain and then cultured for 12 days with or without 0.1 ng/ml rcIL-1ß. Media were refreshed every 3 days and analyzed for MMP activity, ADAMTS-4 activity, MMP-1, MMP-2, MMP-3, GAG, NO, PGE2 , IL-6, IL-8, MCP-1, and KC concentrations. Treatment with IL-1ß alone significantly increased NO, PGE2, general MMP activity, IL-6, IL-8, KC, and MCP-1 media concentrations compared to negative controls. Impact at 75% significantly increased PGE2, IL-6, IL-8, and KC media concentrations compared to negative controls. The combination of IL-1ß and 75% strain significantly increased production of PGE2 compared to IL-1ß or 75% strain alone. Impact injury to meniscal explants ex vivo is associated with increased production of pro-inflammatory mediators and degradative enzyme activity, which are exacerbated by stimulation with IL-1ß. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2657-2663, 2018.
Asunto(s)
Citocinas/metabolismo , Mediadores de Inflamación/metabolismo , Meniscos Tibiales/metabolismo , Lesiones de Menisco Tibial/metabolismo , Animales , Perros , Técnicas In Vitro , Inflamación/metabolismo , Metaloproteinasas de la Matriz/metabolismoRESUMEN
This article identifies the potential mechanisms of action for meniscal degeneration in response to joint inflammation and potential contributions of the meniscus to the development and progression of osteoarthritis (OA). It was hypothesized that interleukin-1ß (IL-1ß) stimulation of meniscal explants would result in significant increases in nitric oxide (NO), matrix metalloproteinase (MMP) production and activity, and relevant cytokine production compared with controls. Canine meniscal explants (4 mm) were cultured for 21 days with (IL-1) or without (negative control [NC]) 50 ng/mL rcIL-1ß (n = 6/group). Media were changed every 3 days and analyzed for MMP activity, ADAMTS-4 activity, MMP-1, MMP-2, MMP-3, MMP-9, MMP-13, NO, prostaglandin E2 (PGE2), IL-6, IL-8, monocyte chemotactic protein-1 (MCP-1), and keratinocyte-derived chemokine (KC) concentrations. Media NO and PGE2 concentrations were significantly higher in the IL-1 group at all time points except for days 9 and 12. The concentrations of MMP-13 were significantly higher in the IL-1 group at days 3, 6, 9, and 12. The production of MMP-2 was significantly lower in the IL-1 group on days 3 through 15. ADAMTS4 activity was significantly higher in the IL-1 group on days 6 through 18. MMP-3 concentrations and general MMP activity were significantly higher in the IL-1 group at all time points. Concentrations of IL-6, IL-8, MCP-1, and KC were significantly higher in the IL-1 group at most time points. Glycosaminoglycans (GAG) content decreased significantly (p = 0.009) in the IL-1 group compared with the NC group. Proinflammatory mediators appear to directly influence degradative processes in the meniscus, which in turn contribute to development and progression of OA by production of proinflammatory and degradative mediators. These findings have important clinical implications for the management of the degenerative meniscus and the osteoarthritic knee.