348 research outputs found

    Προσομοίωση και τεχνοοικονομική αξιολόγηση βιοχημικών διεργασιών δέσμευσης και μετατροπής διοξειδίου του άνθρακα προερχόμενου από απαέρια βιομηχανίας προς χημικές ενώσεις υψηλής αξίας

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    Εθνικό Μετσόβιο Πολυτεχνείο--Μεταπτυχιακή Εργασία. Διεπιστημονικό-Διατμηματικό Πρόγραμμα Μεταπτυχιακών Σπουδών (Δ.Π.Μ.Σ.) “Παραγωγή και Διαχείρηση Ενέργειας

    Urinary Transforming Growth Factor-beta 1 as a marker of response to immunosuppressive treatment, in patients with crescentic nephritis

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    BACKGROUND: Crescentic nephritis is characterized by formation of cellular crescents that soon become fibrotic and result in irreversible damage, unless an effective immunosuppressive therapy is rapidly commenced. TGF-β(1 )is involved in the development of crescents through various pathways. The aim of this study was to identify whether the determination of urinary TGF-β(1 )levels in patients with crescentic nephritis could be used as a marker of response to treatment. METHODS: Fifteen patients with crescentic nephritis were included in the study. The renal expression of TGF-β(1 )was estimated in biopsy sections by immunohistochemistry and urinary TGF-β(1 )levels were determined by quantitative sandwich enzyme immunoassay (EIA). TGF-β(1 )levels were determined at the time of renal biopsy, before the initiation of immunosuppressive treatment (corticosteroids, cyclophosphamide and plasma exchange). Twelve patients with other types of proliferative glomerulonephritis and ten healthy subjects were used as controls. RESULTS: Improvement of renal function with immunosuppressive therapy was observed in 6 and stabilization in 4 patients (serum creatinine from 3.2 ± 1.5 to 1.4 ± 0.1 mg/dl and from 4.4 ± 1.2 to 4.1 ± 0.6 mg/dl, respectively). In 5 patients, with severe impairment of renal function who started on dialysis, no improvement was noted. The main histological feature differentiating these 5 patients from others with improved or stabilized renal function was the percentage patients with poor response to treatment were the percentage of glomeruli with crescents and the presence of ruptured Bowman's capsule and glomerular necrosis. Urinary TGF-β(1 )levels were significantly higher in patients who showed no improvement of renal function with immunosuppressive therapy (930 ± 126 ng/24 h vs. 376 ± 84 ng/24 h, p < 0.01). TGF-β(1 )was identified in crescents and tubular epithelial cells, whereas a significant correlation of TGF-β(1 )immunostaining with the presence of fibrocellular cresents was observed (r = 0.531, p < 0,05). CONCLUSION: Increased TGF-β(1 )renal expression and urinary excretion that is related to the response to immunosuppressive therapy was observed in patients with crescentic nephritis. Evaluation of urinary TGF-β(1 )levels may be proved a useful marker of clinical outcome in patients with crescentic nephritis

    Expression of calponin in periglomerular myofibroblasts of rat kidney with experimental chronic injuries

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    Our previous research demonstrated that calponin-immunoreactivity was localized in myofibroblasts of the periglomerular region of human kidney specimens obtained at the time of transplantation from organ recipients. In the present study we examined calponin expression in two chronic nephropathy models, puromycin aminonucleoside (PAN) nephropathy and subtotal nephrectomy (SNx), to investigate the role of calponin in chronic renal injury. Male Sprague-Dawley rats were used, and both nephropathy models were established at 1, 2, 4, and 8 weeks after surgery. There were no periglomerular calponin-positive cells in sham, PAN 1 and 2 week, and SNx 1, 2, and 4 week groups. In SNx 8 week and PAN 4 and 8 week groups, only a few glomeruli with periglomerular calponin-reactivity, which covered half or a very small part of the periglomerular space, were observed. All glomeruli with periglomerular calponin-reactivity showed sclerotic changes, especially thickening of parietal epithelial cells (PECs). In conjunction with our previous report, this data represents the first documentation of the expression of calponin in renal myofibroblasts. We suggest that interactions between PECs and calponin-positive myofibroblasts may play a key role in the late stage of glomerulosclerosis

    Risk factors for tuberculosis in dialysis patients: a prospective multi-center clinical trial

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    <p>Abstract</p> <p>Background</p> <p>Profound alterations in immune responses associated with uraemia and exacerbated by dialysis increase the risk of developing active tuberculosis (TB) in chronic haemodialysis patients (HDPs). In the current study, was determined the impact of various risk factors on TB development. Our aim was to identify which HDPs need anti-TB preventive therapy.</p> <p>Methods</p> <p>Prospective study of 272 HDPs admitted, through a 36-month period, to our institutions. Specific Relative Risk (RR) for TB was estimated, considering age matched subjects from the general population as reference group. Entering the study all patients were tested with tuberculin (TST). Using Cox's proportional hazard model the independent effect of various risk factors associated with TB development was estimated.</p> <p>Results</p> <p>History of TB, dialysis efficiency, use of Vitamin D supplements, serum albumin and zinc levels were not proved to influence significantly the risk for TB, in contrast to: advanced age (>65 years), BMI, diabetes mellitus, tuberculin reactivity, healed TB lesions on chest X-ray and time on dialysis. Elderly (>70 years old) HDPs (Adjusted RR 25.3, 95%CI 20.4-28.4, P < 0.02), diabetics (Adj.RR 25.3, 95%CI 17.2-21.1, P < 0.03), underweighted (Adj.RR 72.3, 95%CI 65.2-79.8 P < 0.001), tuberculin responders (Adj.RR 41.4, 95%CI 37.9-44.8, P < 0.03), HDPs with fibrotic lesions on chest x-ray (Adj.RR 82.3, 95%CI 51.3-95.5, P < 0.03) and those treated with haemodialysis for < 12 months (Adj.RR 110.0, 95%CI 97.4-135.3, P < 0.001), presented significantly higher specific RR for TB even after adjusting for the effect of the remaining studied risk factors.</p> <p>Conclusion</p> <p>The above mentioned factors have to be considered by the clinicians, evaluating for TB in HDPs. Positive TST, the existence of predisposing risk factors and/or old TB lesions on chest X-ray, will guide the diagnosis of latent TB infection and the selection of those HDPs who need preventive chemoprophylaxis.</p

    Effects of Cyclosporin A Therapy Combined with Steroids and Angiotensin Converting Enzyme Inhibitors on Childhood IgA Nephropathy

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    To evaluate the effects of cyclosporin A (CyA) on clinical outcome and pathologic changes in children with IgA nephropathy (IgAN), we retrospectively evaluated 14 children (mean age 8.9±2.9 yr; eight males, six females) who were treated with CyA and steroids. The starting dose of CyA was 5 mg/kg per day, and the drug level was maintained at 100-200 ng/mL. The mean CyA level was 183.8±48.3 ng/mL (range 120.7-276.0 ng/mL) and the mean duration of CyA therapy was 10.9±1.9 months (range 8-12 months). After CyA therapy the mean 24 hr urinary protein excretion declined from 107.1±35.1 mg/m2/hr to 7.4±2.4 mg/m2/hr (P<0.001) and serum albumin increased from 3.3±0.6 g/dL to 4.3±0.3 g/dL (P<0.001). At a follow-up biopsy the histological grade of IgAN was improved in seven (50%) of the 14 patients, remained the same in three (21%), and was aggravated in four (29%). Serum creatinine, creatinine clearance, and blood pressure did not differ before and after CyA therapy. Two patients (14%) showed CyA-induced nephrotoxicity at the second biopsy. Our findings indicate that CyA therapy may be effective in reducing proteinuria and regressing renal pathology in a subset of children with IgAN
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