Experimental and computational studies of sulfided NiMo supported on pillared clay: catalyst activation and guaiacol adsorption sites.

We report on intermediate (oxysulfides) and sulfided structures of NiMo supported on aluminium pillared clay (Al-PILC) during the catalyst activation process and the prefered guaiacol adsorption sites on the sulfided catalyst. In situ X-ray absorption fine structure (XAFS) together with density functional theory (DFT) calculations confirm the existence of ill-defined suboxides (MoOx, NiOx) and the well-known subsulfides (Mo2S9, Ni3S2) at the first stage which, at a later stage in the process, transform into MoS2 with two edges, oxygen-decorated Mo and Ni with zero sulfur coverage. The freshly sulfided NiMoS2 catalyst under sulfiding agents is mainly terminated by Mo-edge surface with 50% sulfur coverage (Mo-S50) with a disordered Ni-edge surface that can be assigned as NiMoS (1̄010). When exposed to an inert atmosphere such as He gas, the Mo and Ni edges evolved partially into new structures of Mo and Ni edges with zero sulfur coverage, labelled as Mo-Bare and Ni-Bare. Guaiacol is often used as a model compound for lignin and a series of calculations of guaiacol on the structural edges of a sulfided NiMoS2 catalyst show relatively good agreement between the observed and calculated inelastic neutron scattering (INS) spectra for Mo-S50, Ni-Bare, and NiMoS (1̄010) where guaiacol weakly chemisorbed via oxygen atom of OH group. The results also confirm that guaiacol is physisorbed on the basal plane of NiMoS2 in a horizontal (flat-lying) configuration via van der Waals interaction at a separation of about 3.25 Å.

[Indications and controindications of hormone replacement therapy in menopause]. / Indicazioni e controindicazioni della terapia ormonale sostitutiva in menopausa

Menopause is a physiological event of women's life that is the end of menstrual cycles and the end of the fertile period. Normally the age at which women reach menopause is between 50 and 52 years, as the world average. Menopause occurs when the functional ovarian reserve is exhausted or can be induced by surgical removal of the ovaries. What follows, however, is the establishment of a state of hypoestrogenism, which potentially affects various organs and systems (genito-urinary system, cardiovascular system, skeleton, skin, brain) and quality of life of women (varying degrees of vasomotor symptoms, vaginal atrophy, osteoporosis). Hormone replacement therapy (HRT), it is based on estrogen or estrogen and progesterone, can be used to compensate for estrogen deficiency and to prevent or limit the damages that may result. During the years, there have been several observational studies designed to identify the risks and benefits arising from the use of postmenopausal hormone replacement therapy, in spontaneous and surgical menopause. In fact, although several studies have shown that women treated with estrogen enjoyed a better overall level of health, over the last decade have raised doubts about the safety of hormone replacement therapy long term. In our study we try to discuss, based on a review of the literature and evidence available to date, what are the present indications and controindications to the use of hormone replacement therapy.

Perfusional evaluation of postesophagectomy gastroplasty with a radioisotopic study.

SUMMARY: Anastomotic fistula represents one of the frequent causes of postoperative morbidity and mortality following transhiatal esophageal resections. The main etiological factor is the ischemia of the gastric tube created for digestive transit reconstruction. Evidence suggests that per operative hypoperfusion can be maintained or even impaired after the surgery. Several methods have been employed in an attempt to assess the blood perfusion of the gastric flap, but they all pose limitations. However, there is a chronological relationship between perfusion assessments, which are almost exclusively performed per operatively, and the occurrence of a leak, which commonly appears several days after the surgery. The authors have developed a method of gastric perfusion evaluation by single photon emission computed tomography scintigraphy, which corrects that temporal matter, allowing the estimation of postoperative gastric perfusion. It is noninvasive, low cost, and may be applied by the time frame when most fistulas occur. High correlation between the event fistula and the low radiotracer uptake in the group of studied patients could be demonstrated. A role in the research of perfusion evaluation of different types of esophageal reconstruction is suggested.

Older adults with history of falls are unable to perform walking and prehension movements simultaneously.

Older adults have a greater incidence of falls, and risk of falls will increase when combining two motor tasks. Thus, it is interesting to investigate the effect of fall history on motor performance in older adults when combining walking with another task such as grasping an object. The aim of this study was to investigate the combined task of walking and prehension with different levels of manual task difficulty in older adults with and without a history of falls. Thirty older adults participated in this study; groups were designated as fallers (n=15) and non-fallers (n=15). Participants were asked to reach-to-grasp a dowel during quiet standing and during walking. Level of manual task difficulty was manipulated by the type of dowel support and obstacles located at different distances to the sides of the dowel. Fall history influenced the performance of this combined task for the most difficult manual conditions. Fallers were able to be identified due to differences in the grasping strategies used while walking compared to non-fallers. In addition, walking and grasping were mutually modulated due to the level of difficulty of the manual task.

Synoviocytes in chronic synovitis in situ and cytokine stimulated synovial cells in vitro neo-express alpha 1, alpha 3 and alpha 5 chains of beta 1 integrins.

The expression of the beta 1 integrins was examined immunohistochemically in synoviocytes from normal synovitis membrane and from chronic synovitis of different aetiology and intensity. Normal synoviocytes were alpha 6 beta 1-positive but lacked alpha 1 through alpha 5. In mild inflammation type A synoviocytes neo-expressed alpha 1, alpha 3, and alpha 5 chains. In severe inflammation both type A and B synoviocytes expressed alpha 3, alpha 4, alpha 5, and alpha 6 chains. The effects of inflammatory cytokines, as single agents or in combination, on the beta 1 integrin expression in cultured normal synoviocytes was determined by immunocytochemistry and flow cytometry. The alpha 1 chain, while absent in unstimulated synoviocytes, was induced by interleukin-1 beta (IL-1 beta), tumour necrosis factor-alpha (TNF-alpha), and interferon-gamma (IFN-gamma). This effect was enhanced by combining IL-1 beta and TNF-alpha. Expression of the alpha 3 chain was up-regulated by IL-1 beta and, more intensely, by IFN-gamma. Transforming growth factor beta (TGF-beta) inhibited the up-regulating effect of IL-1 beta and antagonized the effect of IFN-gamma on alpha 3 chain expression. Expression of the alpha 5 chain was up-regulated significantly by co-stimulation through IL-1 beta together with TGF-beta or TNF-alpha. Thus, the beta 1 integrin profile of cytokine activated synoviocytes in vitro resembled that of synoviocytes in synovitis in situ. These data suggest that IL-1 beta, TNF-alpha, IFN-gamma, and TGF-beta are likely to be among the effectors regulating beta 1 integrin expression in synoviocytes in vivo.

PMA-activation of peripheral blood and tonsillar B lymphocytes induces large adhesive cells reminiscent of large extrafollicular (monocytoid) B cells.

Extrafollicular (EF) B lymphocytes differ in size and morphology depending on the lymphatic organ involved and the kind of inflammatory reaction. On re-evaluating EF B cells in various sites and conditions we discriminated three forms: a small (lymphoid) and intermediate (centrocytoid), and a large (monocytoid) variant. Immunohistochemically, these variants could be discriminated by their differential expression of adhesion molecules CD62L (L-selectin) and CD11c: small EF B cells were strongly L-selectin+ and CD11c-; intermediate cells were moderately CD62L+ and CD11c-; large cells were faintly CD62L+ or - but expressed CD11c. In 72 h cultures of normal peripheral and tonsillar B cells, cross-linking surface immunoglobulin in the presence of interleukin-2 or interleukin-4 led to formation of clusters in vitro together with an increase in cell size and a slight up-regulation of CD11c, as determined by flow cytometry. Stimulation with phorbol 12-myristate 13-acetate (PMA), however, gave rise to large, plastic adherent cells which also showed strong homotypic adhesion, expressed CD62L at minimal levels and CD11c at comparably highest levels and altogether mimicked the large cell variant of EF B cells. We conclude that EF B cells are subjected to cytokine-induced metamorphosis and that differences in cell size and morphology reflect their state of activation and activation-associated adhesion properties. Our data suggest that EF B cells in all anatomical sites are functionally closely related cells which--possibly mediated by CD11c/CD18--may become sessile and proliferate locally once activated by appropriate signals.

Loss of collagen type IV in rheumatoid synovia and cytokine effect on the collagen type-IV gene expression in fibroblast-like synoviocytes from rheumatoid arthritis.

Collagen type IV is a structural matrix protein which contributes to the structural organization of the synovia. In order to characterize the distribution of this protein in synovia with chronic synovitis, collagen type IV was detected by immunochemistry in normal synovia and in synovia from patients with osteoarthritis (OA) and rheumatoid arthritis (RA). A decrease of collagen type IV was observed in synovial layers of rheumatoid synovia, which statistically correlated with the grade of inflammation and with the thickness of the synovial layer. In vitro, we found no differences in the gene expression of collagen type IV in cultures of fibroblast-like synoviocytes (FLS) derived from OA and RA using a reverse-transcriptase polymerase chain reaction. Nevertheless, we observed a downregulating effect of tumor necrosis factor-alpha and interleukin (IL)-1beta on the gene expression of collagen type IV only in FLS isolated from patients with RA. The effect of IL-1beta was dose dependent. In summary, we observed an inflammation-associated decrease of collagen type IV in the synovial layer of rheumatoid synovia. Inflammatory cytokines may play a role in regulating the synthesis of collagen type IV in the rheumatoid process in vivo.

Terminal complement complex in synovial tissue from patients affected by rheumatoid arthritis, osteoarthritis and acute joint trauma.

The C5b-9 complex (Terminal Complement Complex-TCC) is the final product of the terminal complement pathway. In this study, using the monoclonal antibody MCaE11 (specific for a C9 neoantigen) and an immunohistochemical technique, we examined the TCC deposits in synovial tissues from 4 patients affected by rheumatoid arthritis (RA) and 6 patients affected by osteoarthritis (OA). Synovial tissues from 8 patients affected by acute joint trauma were examined as controls. Furthermore, plasma TCC levels were measured in 44 RA patients and 51 controls, using the above mentioned antibody and a sandwich ELISA. Eight synovial fluids were also included in this study. Abundant TCC deposits were detected in the cytoplasm of the synovial lining cells and of large stromal mononuclear cells in all the RA and in 3 out of 6 OA synovial tissues characterized by histological signs of inflammation. No TCC deposits were found in non-inflamed synovial tissues from patients with joint trauma. In agreement with previous observations, the TCC plasma levels found were significantly higher in RA patients than in controls, but no difference was seen between patients with active and non-active disease. The mean TCC level was significantly higher in the synovial fluid than in the plasma, but no correlation emerged between these two series of values. This study shows that: a) the plasma level of TCCs cannot serve as an indicator of disease activity in RA; b) the TCC deposits in synovial tissue correlate well with the extent of inflammatory synovitis, irrespective of whether the synovitis is rheumatoid or osteoarthritic in nature.

MR imaging of rheumatoid hand lesions: comparison with conventional radiology in 31 patients.

The purpose of this study was to evaluate the diagnostic accuracy of magnetic resonance imaging (MRI) in rheumatoid arthritis (RA) by comparing MRI with conventional radiology (CR) findings and by correlating these findings with the clinical and serological profile of the disease. The hands of 31 patients (24 females, 7 males) affected by classical RA were studied using a Magnetom 1.0 T tomograph. Coronal, axial, and/or sagittal SE T1 and GE (FLASH 2D FL: 70 degrees-15 degrees) images were obtained in all patients. Moreover, in 7 patients the MRI study was performed after i.v. injection of Gd DTPA contrast medium (0.2 mM/kg). Ten healthy volunteers were also studied as controls. In all patients a conventional radiological study was performed as well as a clinical and serological investigation. Two blinded observers evaluated the MRI and CR findings and checked 15 elementary pathological lesions, assigning an MRI and a CR score to each patient. MRI provided higher accuracy than CR in detecting rheumatoid soft tissue changes and minimal skeletal lesions, while the opposite was true for severe skeletal lesions. No correlations emerged between the MRI/CR findings and clinical and serological data. This study suggests that MRI and CR are complementary techniques in the evaluation of the anatomical changes in RA.

Seltene Manifestation einer Grossgefassvaskulitis bei|| systemischem Lupus erythematodes.

Case-reports from two female patients with an occlusion||| of the right external iliac artery and femoral artery are presented due to a||| large-vessel vasculitis. Both patients suffered from systemic lupus||| erythematosus This rare manifestation occurred within the first few years of||| the disease and was important for prognosis and further treatment. Other||| manifestations of the disease were general symptoms and polyarthritis. In one||| case the vasculitis was confirmed by histology. A fibrous thickening of the||| intima and a vasculitis of small vessels within the adventitia were the||| prominent feature. This observation supports the idea of small vessel||| vasculitis as the characteristic manifestation in lupus||| erythematosus.

[Molecular mechanisms of cell-cell and cell-matrix interactions in the pathophysiology of rheumatoid arthritis]. / Molekulare Mechanismen der Zell-Zell- und Zell-Matrix-Interaktionen in der Pathophysiologie der Rheumatoiden Arthritis.

The original structure of the synovial membrane is completely destroyed in the rheumatoid synovium and is characterized by mononuclear cell infiltration, synoviocyte proliferation, neo-vascularization, and deposition of extracellular matrix proteins. Adhesion molecules play an important role in the development of these pathologic changes. In this review we discuss the role of the adhesion receptors of the selectin, integrin and immunoglobulin families and of the CD44 molecule in the cell-cell and cell-matrix interaction in the pathogenesis of the inflammatory changes in rheumatoid arthritis.

Methotrexate in patients with moderate systemic lupus erythematosus (exclusion of renal and central nervous system disease).

OBJECTIVES: Methotrexate (MTX) has been used in several autoimmune diseases. Apart from its use in rheumatoid arthritis, MTX has been assessed in small studies in patients with vasculitis, uveitis, and inflammatory bowel disease. The aim of this study was to evaluate the efficacy of MTX in a particular group of patients with systemic lupus erythematosus (SLE). PATIENTS: In an open prospective study 22 patients fulfilling the ACR criteria for SLE were included. Patients had one or more of the following manifestations; active non-destructive polyarthritis, dermatitis, vasculitis of the skin, pleuritis. All patients had been treated with corticosteroids for at least six months without achieving remission. Sixteen patients were taking antimalarial drugs in addition to corticosteroids, which were stopped at the beginning of the trial. Patients with renal and central nervous involvement were excluded from the study. All patients received MTX orally at a dose of 15 mg/week over six months. Corticosteroids were continued. As additional medication only indomethacin up to 100 mg/day was permitted if used before the start of the study. The outcome was evaluated using the SLE disease activity index (SLEDAI). RESULTS: Disease activity was evaluated after six months of MTX treatment. All patients completed the study period. The SLEDAI decreased significantly from mean (SD) 12.2 (3.99) to 4 (3.75) (p = 0.001). The prednisolone dose was reduced from a mean (SD) of 17.4 (12.8) at the beginning to 8.8 (5.36) mg/day at the end point of the study (p = 0.01). MTX was well tolerated. Four patients complained of general malaise. Two patients had transient increases in liver enzymes. In no case did MTX have to be stopped. CONCLUSIONS: In an open prospective study methotrexate was used in SLE patients with particular clinical characteristics. MTX was shown to be effective in reducing disease activity and sparing the dose of corticosteroids. Further controlled studies are necessary.

[Rare manifestation of large vessel vasculitis in systemic lupus erythematosus]. / Seltene Manifestation einer Grossgefässvaskulitis bei systemischem Lupus erythematodes.

Case-reports from two female patients with an occlusion of the right external iliac artery and femoral artery are presented due to a large-vessel vasculitis. Both patients suffered from systemic lupus erythematosus This rare manifestation occurred within the first few years of the disease and was important for prognosis and further treatment. Other manifestations of the disease were general symptoms and polyarthritis. In one case the vasculitis was confirmed by histology. A fibrous thickening of the intima and a vasculitis of small vessels within the adventitia were the prominent feature. This observation supports the idea of small vessel vasculitis as the characteristic manifestation in lupus erythematosus.

Pleural mesothelioma mimics the integrin profile of activated, sessile rather than detached mesothelial cells.

Mesothelial cells (MC) form a polarized monolayer lining serosal cavities. During serositis, the MC lining undergoes hyperplasia, and MC are shed into effusions. During these processes, contact with basement membrane and, ultimately, neighboring cells is at least temporarily lost, suggesting regulated alterations in cell/matrix and cell/cell adhesion. Such interactions are primarily mediated by integrins. Malignant mesothelioma has a growth pattern characterized by lateral, limited invasive but contiguous spread. During serositis, activated MC, both sessile and detached, expressed an extended spectrum of beta1, beta3 and beta4 integrins compared with resting MC, as shown by immunohistology. Malignant mesothelioma had an integrin repertoire and a subcellular distribution resembling that of activated sessile rather than floating MC. In vitro, MC exposed a more comprehensive pattern of integrins than that of the newly established mesothelioma cell lines ME-HD-1 and ME-HD-2, as shown by flow cytometry. MC consistently adhered better than mesothelioma cells to laminin, tenascin, fibronectin and collagen type IV. Adhesion of MC and mesothelioma cells to these matrix proteins was, at least in part, mediated via beta1 integrins. The different integrin profiles and adhesion properties of cultured MC and mesothelioma cells may reflect a limited functional differentiation of the latter.

Differential expression and functional behaviour of the alpha v and beta 3 integrin subunits in cytokine stimulated fibroblast-like cells derived from synovial tissue of rheumatoid arthritis and osteoarthritis in vitro.

OBJECTIVE: The aim of this study was to investigate in situ the expression of the classic vitronectin (VN) receptor consisting of the alpha v and beta 3 subunits in synovial lining cells (SLC) of chronic synovitis occurring in osteoarthritis (OA) and in rheumatoid arthritis (RA). The expression and function of alpha v and beta 3 as VN receptor in cultured fibroblast-like synoviocytes (FBS) derived from patients with OA and RA was also compared. METHODS: Expression of alpha v and beta 3 was examined immunohistochemically in normal synovial tissue and in synovial tissue from patients with OA and RA. The effect of proinflammatory cytokines and of a synovial fluid of a patient with RA on the expression of the alpha v and beta 3 subunits of cultured FBS was determined by flow cytometry. Binding of OA and RA-FBS to VN was quantified using adhesion assays and the effect of interleukin 1 beta (IL1 beta) and tumour necrosis factor alpha (TNF alpha) on adhesion was measured. The specificity of the adhesion was tested by inhibition studies using monoclonal antibodies to integrin subunits. RESULTS: In in situ studies normal SLC showed a parallel distribution of alpha v and beta 3 subunits. OA-SLC strongly and uniformly expressed alpha v whereas RA-SLC showed heterogeneous expression of alpha v. In situ both OA-SLC and RA-SLC lacked the expression of the integrin subunit beta 3. In in vitro studies, OA-FBS and RA-FBS did not differ as regards expression of alpha v and beta 3, and VN attachment. Binding of RA-FBS to VN was partially blocked by antibodies against alpha v, beta 1, and beta 3 subunits, whereas only antibodies against alpha v and beta 3 inhibited the binding of OA-FBS to VN. The proinflammatory cytokines TNF alpha and IL1 beta increased the expression of alpha v and beta 3, and the VN binding of OA-FBS, whereas alpha v and beta 3 expression, and VN binding were downregulated in RA-FBS. Similar effects were found when the synovial fluid of an RA patient was used. CONCLUSION: The integrin subunit beta 3 seems to be one partner but not the major one with which the subunit alpha v forms functional vitronectin receptors in OA-FBS and RA-FBS. The interaction between synovial cells and inflammatory cytokines seems to be different for OA and RA; the basis for this difference, however, remains to be established.

[The significance of cardiolipin antibodies in systemic lupus erythematosus]. / Die Bedeutung von Cardiolipinantikörpern beim systemischen Lupus erythematodes.

The aim of the study was to investigate the frequency and clinical significance of anticardiolipin antibodies (aCL) in systemic lupus erythematosus (SLE). 32 of 100 patients with SLE had positive anticardiolipin antibodies. Increased aCL were associated with thrombosis, thrombocytopenia, miscarriage, vasculitic skin changes and neurological symptoms. The incidence of thrombosis, thrombocytopenia, and neurological symptoms was significantly increased in the aCL-positive group as compared to the aCL-negative group. These findings confirm the results of former investigations and underline the role of aCL in systemic lupus erythematosus.

Increased expression of integrins on fibroblast-like synoviocytes from rheumatoid arthritis in vitro correlates with enhanced binding to extracellular matrix proteins.

OBJECTIVE: To compare in vitro expression of beta 1, beta 3, and beta 4 integrins in normal fibroblast-like synoviocytes (FBS) and in FBS from rheumatoid arthritis (RA) synovium and to investigate the adhesion of normal FBS and RA-FBS to the integrin binding extracellular matrix (ECM) proteins: collagen type IV, fibronectin, laminin, and tenascin. METHODS: Expression of integrin receptors of cultured FBS was detected by flow cytometry. Attachment of FBS to ECM proteins was quantified by adhesion assays. Inhibition studies were performed using monoclonal antibodies to the integrin subunits. RESULTS: Compared with normal FBS, RA-FBS showed increased expression of alpha 1 to alpha 6, beta 1, and beta 4 integrin subunits and enhanced binding of ECM proteins. Binding to ECM proteins was partly or completely blocked by an anti-beta 1 integrin antibody and antibodies to alpha 3, alpha 5, and alpha 6 integrin subunits. The blocking efficiency was significantly (P < 0.05) higher in RA-FBS than in normal FBS. CONCLUSIONS: The enhanced expression of the beta 1 integrin receptors on cultured RA-FBS correlated with increased attachment to ECM proteins. Adhesion of normal and RA-FBS to ECM proteins is mediated through beta 1 integrin receptors. Therefore, the tight binding of rheumatoid FBS to the matrix via beta 1 integrins might play a role in ECM remodelling in the rheumatoid process in vivo.

[Normal synoviocytes and synoviocytes from osteoarthritis and rheumatoid arthritis bind extracellular matrix proteins differently]. / Normale Synoviozyten und Synoviozyten aus Osteoarthritis und rheumatoider Arthritis binden unterschiedlich an extrazelluläre Matrixproteine.

Extracellular matrix proteins are increased in inflammatory synovitis. We showed previously that the in situ expression of the corresponding extracellular matrix receptors (beta 1-integrins) is enhanced in synoviocytes (SC) of synovitis of different etiology (16). To investigate the adhesion of SC to extracellular matrix proteins, we examined the attachment of SC from normal and inflamed synovia to fibronectin, tenascin, laminin and collagen type IV. Compared to normal SC and SC of osteoarthritis, SC of rheumatoid arthritis showed an increased binding to tenascin, laminin, fibronectin and collagen type IV, suggesting a distinctive interaction of SC and extracellular matrix proteins in rheumatoid arthritis. Furthermore, the increased binding of SC of rheumatoid arthritis to extracellular matrix proteins may play a role in tissue remodelling associated with rheumatoid arthritis.

Loss of laminin and of the laminin receptor integrin subunit alpha 6 in situ correlates with cytokine induced down regulation of alpha 6 on fibroblast-like synoviocytes from rheumatoid arthritis.

OBJECTIVE: To investigate in situ the expression of the integrin receptor subunits alpha 6 and beta 1 and the distribution of the ligand laminin in the synovia from osteoarthritis (OA) and rheumatoid arthritis (RA) patients and to study the effect of cytokines and antirheumatic drugs on the expression of the alpha 6 and beta 1 integrin subunits on long term cultures of fibroblast-like synoviocytes (FBS) derived from OA and RA. METHODS: The expression of the alpha 6 and beta 1 integrin subunits and the distribution of laminin were examined immunohistochemically in normal synovia and in synovia from patients with OA and RA. The effect of proinflammatory cytokines (IL1 beta and TNF alpha), and of antirheumatic drugs (salicylic acid, dexamethasone, and methotrexate) on the alpha 6 and beta 1 expression of cultured normal FBS and FBS from patients with OA and RA was determined by flow cytometry. RESULTS: In normal synovia and in OA synovia samples with a low grade of inflammation, synovial lining cells (SLC) showed a parallel expression and distribution of alpha 6 and laminin. In synovia samples of OA with a higher grade of inflammation and in the majority of RA synovia samples laminin was pericellularly distributed in a low number of SLC, whereas alpha 6 was expressed on the surface of a high number of SLC. In RA synovia samples with severe inflammatory changes the gradual loss of laminin generally corresponded to a decrease of the alpha 6 integrin subunit. beta 1 was always strongly expressed in all synovia samples detected. Proinflammatory cytokines up regulated the expression of alpha 6 and beta 1 on OA-FBS, whereas these effectors decreases alpha 6 and beta 1 on RA-FBS. In contrast, antirheumatic drugs, in particular methotrexate and dexamethasone, reduced the expression of alpha 6 and beta 1 on OA-FBS, whereas the same treatment on RA-FBS stimulated the expression of these integrin subunits. CONCLUSION: The gradual loss of laminin in chronic synovitis may contribute to the altered expression of alpha 6 in SLC. IL1 beta and TNF alpha down regulated the expression of the alpha 6 and beta 1 integrin subunits on long term cultures of FBS derived from RA. Therefore, these cytokines may be among the effectors regulating the expression of the alpha 6 integrin subunit in SLC in vivo. As antirheumatic drugs increase the expression of alpha 6 on RA-FBS, the presence of the laminin receptor may confer a protective effect on the synovia in vivo.