Lining Layer Thickness Research Articles

A study to analyze the pattern of synovial lesions from synovial biopsies in a tertiary care centre.

Synovium has been documented as a primary site of inflammation and a major effector organ in a variety of joint diseases. Study of simple technique like synovial biopsy can help in early diagnosis and treatment of diseases significantly improving outcome of patient in cases of rheumatoid arthritis, osteoarthritis, etc., Only limited data exist on utility of synovial biopsies. To analyze the pattern of synovial lesions to differentiate between different kinds of arthritis. Also, to identify early stages of arthritis so as to prevent unnecessary invasive surgical procedure. It's a retrospective study to analyze 103 cases of synovial lesions diagnosed in last five years at a tertiary care orthopedic center. All synovial biopsies obtained mainly by open method and few by arthroscopic method, that came to the Dept of Pathology were included. Lesions were classified into four categories that is, inflammatory joint diseases, degenerative joint diseases, tumor-like conditions and tumors. Age group most affected was between 61 and 70 years, with male predominance. Osteoarthritis (OA) was the most common histopathological diagnosis. Early OA tissues showed greater lining layer thickness, vessel proliferation, and inflammation, while surface fibrin deposition along with fibrosis was noted in later stages. The histo-morphological observations made in this study may have important therapeutic implications for some patients during the early evolution of arthritis and could prevent unnecessary operative intervention of later stages.

FRI0508 Correlation of power doppler ultrasonographic findings with site-matched histopathology of the synovial tissue

BackgroundUltrasonography (US) has been recently established as an imaging modality to evaluate inflamed joints of patients with rheumatoid arthritis (RA). It is reported that power doppler ultrasonography (PDUS) is capable...

Influence of the Lining on the Thermal Behaviour of a Teeming Ladle

Exact knowledge of the thermal behaviour of the steelmaking ladle is essential for an effective performance of the secondary metallurgical treatment. In order to predict the influence of working parameters, some thermal ladle models have already been developed and presented. The development of new complicated thermal ladle models or the mathematical description of modelling are important. Nevertheless exact model studies of the influencing factors on the thermal state of the ladle are of similar significance. Especially for ladle modernisation concepts, when the lining layer thickness is changed or new refractory materials are used, the question arises if there is an influence of modernisation on the thermal state of the ladle, heat losses or steel melt temperature. The selected refractory materials represent a decisive factor. The thermal properties of the wear‐resistant lining influence the temperature changes and heat losses in the ladle, whereas the properties of the back and insulating lining are accountable for the steel shell temperature of the ladle. The thermal state of the ladle as a function of the real inner ladle lining has already been investigated. The present work is concentrated on the influence of the real back lining and insulating lining.

Reduction of synovial sublining layer inflammation and proinflammatory cytokine expression in psoriatic arthritis treated with methotrexate.

Methotrexate is one of the most commonly used disease-modifying antirheumatic drugs in the management of psoriatic arthritis (PsA). Despite the differences between the inflammation in PsA and rheumatoid arthritis (RA), the effects of methotrexate on the synovium have been described solely in RA. In this study, we sought to determine the effects of methotrexate on the inflammatory infiltrate and on cytokine and metalloproteinase gene expression in the synovium of PsA patients. Ten patients with PsA (median duration 18 months) underwent arthroscopy and synovial biopsy of an inflamed knee before and after clinical improvement induced by methotrexate. Immunohistologic analysis was performed using antibodies to CD3, CD4, CD8, CD68, factor VIII, vascular cell adhesion molecule, E-selectin, and intercellular adhesion molecule (ICAM). Matrix metalloproteinase 3 (MMP-3) and tissue inhibitor of metalloproteinases 1 (TIMP-1) messenger RNA (mRNA) were quantified by competitive reverse transcription-polymerase chain reaction (RT-PCR). Interleukin-1alpha (IL-1alpha), IL-1beta, IL-2, IL-4, IL-5, IL-8, IL-10, IL-12p35, IL-12p40, IL-15, interferon-gamma (IFNgamma), and tumor necrosis factor alpha (TNFalpha) mRNA expression was quantified by real-time PCR. Patients received a median methotrexate dosage of 13.75 mg/week (range 7.5-15) for a median of 11.5 months (range 7-14 months). The Ritchie Articular Index, swollen joint count, and Disease Activity Score were significantly reduced. There was a decrease in all immunohistologic staining, although this was statistically significant only for CD3, CD4, CD8, CD68, E-selectin, and ICAM. Despite clinical improvement in all patients, there was a residual T cell infiltrate in all synovial biopsy tissues. The synovial lining layer thickness, but not hypervascularity, was significantly reduced. There was also a significant reduction in MMP-3, but not TIMP-1, expression. Before treatment, PsA synovium was characterized by a predominant expression of the proinflammatory cytokines IL-15, IFNgamma, IL-1beta, and TNFalpha and the antiinflammatory cytokine IL-10. Methotrexate reduced synovial IL-1alpha, IL-1beta, IL-8, IL-10, IL-15, IFNgamma, and TNFalpha mRNA expression, but the effect was significant only for IL-8. Methotrexate produced a clinical response in PsA by reducing, but not abolishing, the inflammatory infiltrate, adhesion molecule expression, and MMP-3 and proinflammatory cytokine gene expression, particularly IL-8, in the synovium. Methotrexate did not reduce hypervascularity, which is a prominent differentiating feature of PsA synovium.

Treatment-induced remission in rheumatoid arthritis patients is characterized by a reduction in macrophage content of synovial biopsies.

To document the change in synovial membrane macrophage and T-lymphocyte content in rheumatoid arthritis (RA) patients who achieve remission induced by disease-modifying anti-rheumatic drugs (DMARDs). Arthroscopic synovial biopsies were taken from four to seven sites around a knee joint in 13 patients with RA before and at regular intervals after commencing treatment with a DMARD. The cellular content of synovial membrane biopsies taken at regular intervals for a period of up to 3 yr after commencing treatment was quantitated by routine histopathology and immunohistochemical labelling with anti-macrophage (CD68) and anti-T lymphocyte (UCHL-1) antibodies. Synovial biopsies were quantitated with a validated semiquantitative scoring system and video image analysis. Nine patients obtained clinical remission, as defined by American College of Rheumatology (ACR) criteria. The changes that occurred in the synovial biopsies included a reduction in lining layer thickness, reduced vascularity and cellular infiltrate. The most significant reduction in cellular infiltrate was in the lining layer macrophages, with less dramatic change in the subintimal macrophage infiltrate. Although there was a reduction in CD45 Ro-positive T lymphocytes in the synovial membranes of patients who attained ACR-defined disease remission, it was less significant than the reduction in macrophage content of the synovial membranes and tended to plateau at a reduced level of T-cell infiltration. Remission in RA patients is characterized by a predominant reduction in macrophage content of the synovial membrane, suggesting that current DMARDs may target this cell and its inflammatory mediators.

Immunomodulatory effects of anti-tumor necrosis factor alpha therapy on synovium in spondylarthropathy: histologic findings in eight patients from an open-label pilot study.

To assess the effects of treatment with anti-tumor necrosis factor alpha (anti-TNFalpha) on synovial histology in patients with spondylarthropathy (SpA) in order to confirm the effect on peripheral synovitis and to investigate the immunologic mechanisms involved in anti-TNFalpha therapy. Patients with treatment-resistant SpA were treated with infliximab (5 mg/kg) at weeks 0, 2, and 6 in an open-label pilot study. In 8 patients, synovial biopsy tissues obtained at baseline, week 2, and week 12 were used for histologic and immunohistochemical evaluation. In all 8 patients (3 with ankylosing spondylitis, 1 with undifferentiated SpA, and 4 with psoriatic arthritis), there was a clear clinical improvement in the peripheral arthritis after anti-TNFalpha therapy. Histologic analysis of the synovial biopsy tissues indicated that the synovial lining layer thickness tended to decrease, with a significant reduction of CD55+ synoviocytes, at week 12. In the sublining layer, vascularity was reduced at week 12, with a decreased endothelial expression of vascular cell adhesion molecule 1 but not intercellular adhesion molecule 1, platelet endothelial cell adhesion molecule 1, and E-selectin. Although at week 2 and week 12, the number of neutrophils and CD68+ macrophages in the sublining layer was decreased, the overall degree of inflammatory infiltration remained unchanged. This could be related to the lymphocyte infiltration since at week 12, only CD4+ cells (but not CD3+, CD45RO+, and CD8+ cells) tended to decrease, while CD20+ lymphocytes and plasma cells were clearly increased. The reduction in lining layer thickness, vascularity, and infiltration with neutrophils and macrophages paralleled the beneficial effect of anti-TNFalpha therapy on peripheral synovitis in 8 patients with different subtypes of SpA. The adhesion molecule expression, T cell infiltration, and, most important, B cell infiltration seemed to contrast with previous observations in RA. Although these preliminary data need to be confirmed in a larger cohort, they suggest distinct immunomodulatory mechanisms of anti-TNFalpha in SpA.

Macrophage-derived cytokine and nuclear factor kappaB p65 expression in synovial membrane and skin of patients with psoriatic arthritis.

Monocyte-derived cytokines are important mediators in synovitis and represent novel therapeutic targets. This study was undertaken to analyze their expression in synovial membrane (SM) of patients with psoriatic arthritis (PsA) compared with that in skin of patients with PsA and SM of patients with rheumatoid arthritis (RA). Multiple synovial biopsy samples (24 from patients with PsA, 20 from patients with RA, 5 from patients with osteoarthritis [OA]) and skin biopsy samples (lesional and perilesional skin from 25 PsA patients) were obtained. Standard leukocyte antigens, cytokines (tumor necrosis factor alpha [TNFalpha], interleukin-1apha [IL-1alpha], IL-1beta, IL-15, and IL-10) and the transcription factor nuclear factor KB (NF-kappaB; active p65 subunit) were localized and quantified immunohistochemically by light microscopy and digital image analysis. Sublining cellular infiltration, lymphoid aggregation, and vascularity were similar in PsA and RA SM. Lining layer thickness was greater in RA SM, associated with more CD68+ macrophages. In PsA SM, TNFalpha, IL-1alpha, IL-1beta, IL-15, and IL-10 were primarily localized to lining layer and perivascular macrophages, as were cells expressing the active subunit of NF-kappaB (p65). TNFalpha, IL-1p, and IL-15 expression in PsA lining layer was less than that in RA lining layer, likely reflecting lower macrophage numbers. In sublining areas, levels of TNFalpha and IL-15 were lower in PsA patients than in RA patients, whereas IL-lalpha and IL-1beta expression was equivalent. IL-10 was identified at similar levels in RA and PsA SM lining layer and sublining. Expression of NF-kappaB (p65) was equal in lining layer from both patient groups, but lower in PsA than RA sublining. Histologic findings did not correlate with clinical parameters of disease. Cytokine expression in skin did not correlate directly with that in SM. Cytokine expression was greater in PsA and RA SM than in OA SM. This study shows, for the first time, that monocyte-derived cytokines are found in PsA SM and demonstrates the relative paucity of the antiinflammatory cytokine IL-10 in PsA skin and SM. Significant divergence from RA SM expression was observed, despite similar clinical and demographic features in the 2 patient groups.

Alveolar lining layer is thin and continuous: low-temperature scanning electron microscopy of rat lung.

The low-temperature electron microscope, which preserves aqueous structures as solid water at liquid nitrogen temperature, was used to image the alveolar lining layer, including surfactant and its aqueous subphase, of air-filled lungs frozen in anesthetized rats at 15-cmH2O transpulmonary pressure. Lining layer thickness was measured on cross fractures of walls of the outermost subpleural alveoli that could be solidified with metal mirror cryofixation at rates sufficient to limit ice crystal growth to 10 nm and prevent appreciable water movement. The thickness of the liquid layer averaged 0.14 micron over relatively flat portions of the alveolar walls, 0.89 micron at the alveolar wall junctions, and 0.09 micron over the protruding features (9 rats, 20 walls, 16 junctions, and 146 areas), for an area-weighted average thickness of 0.2 micron. The alveolar lining layer appears continuous, submerging epithelial cell microvilli and intercellular junctional ridges; varies from a few nanometers to several micrometers in thickness, and serves to smooth the alveolar air-liquid interface in lungs inflated to zone 1 or 2 conditions.

Production of angiotensin converting enzyme by rheumatoid synovial membrane.

Vascular proliferation and mononuclear cell infiltration are prominent changes observed in synovium from actively inflamed joints of patients with rheumatoid arthritis. Angiotensin converting enzyme (ACE) is a halide activated peptidase produced mainly by endothelial cells and by activated monocytes. It has been proposed that levels of ACE activity in synovial fluid might reflect changes in membrane vascularity, the degree of monocyte infiltration, or the thickness of the lining layer. In this study, ACE activity in serum and synovial fluid samples from 18 patients with inflammatory arthritis was measured and compared with levels in 12 control subjects with non-inflammatory arthritis. Although serum levels were similar in the two groups, ACE activity in synovial fluid was significantly increased in the group with inflammatory arthritis compared with controls (mean (SE) 37 (5) v 19 (3)). Staining of synovial membranes from patients with rheumatoid arthritis with a monoclonal antibody to ACE localised ACE to the endothelium and to mononuclear cells of macrophage origin. ACE activity was then measured in supernatants of synovial membrane from patients with rheumatoid arthritis after one and seven days of culture. A significant increase in ACE activity was observed after seven days of culture (mean (SE) day 1, 17 (5) v day 7, 25 (3)). Levels of ACE activity, however, did not correlate with the lining layer thickness, with the number of macrophages per square millimetre, nor with the number of blood vessels per square millimetre of synovial tissue. No correlation was observed either between levels of ACE in the supernatant of synovial membrane and levels of interleukin 1 or interleukin 6. In conclusion, ACE is produced by the synovial membrane of patients with rheumatoid arthritis and is localised to monocytes and endothelial cells. Levels of activity do not directly reflect membrane vascularity, monocyte or macrophage number, or the thickness of the lining layer.