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Biomedical subjects

S Stefoni

Publications and source records attributed to S Stefoni.

At least 19 recordsLinked to original sources
PubMed1992

Epidemiology of hepatitis C in a population of hemodialysis patients.

A search for antibodies against hepatitis C virus (HCV) was performed in 185 patients on chronic hemodialysis by means of 1st and 2nd generation ELISA tests. Immunoblot assays were performed on positive sera. This study shows a 38% prevalence of HCV-positive patients in our dialysis population according to the 2nd generation ELISA test which shows a higher specificity and sensitivity when compared to the 1st generation one (38 vs. 20%). A correlation was found between the prevalence of HCV-positive patients and how long they had been on dialysis and how many blood transfusions they had received.

Cross Infection↗
PubMed1992

Phosphate removal by resin hemoperfusion efficacy and biocompatibility of a new exchange resin.

A new coated anionic exchange resin for blood purification specifically designed to remove phosphates was experimentally employed in animals. 3 pigs, in which uremia had been surgically induced, underwent 6 extracorporeal hemoperfusion sessions (2 per pig) with a cartridge containing 100 gr of resin. The phosphate clearance proved satisfactory, values being 120 ml/min after 10' and around 80 ml/min after 2 hours. The biocompatibility of the resin and of the coating membrane was satisfactory. The negligible variation in pH and plasma bicarbonate during all sessions confirmed the low absorption by the tested resin of other blood anions competing with phosphate.

Animals↗
PubMed1992

Hemoperfusion with a new anion exchange resin corrects the metabolic alkalosis in pyloric stenosis: an experimental demonstration.

An experimental model of hypertrophic pyloric stenosis was made by suture of the pyloric wall and gastrostomy in 10 rabbits under general anesthesia. Blood sampling indicated severe alkalosis and hypochloremia 3h 30 min after surgery. To correct the derangement, we tested an ion exchange resin (Dowex SAR), coated with a methacrylic hydrogel. A cartridge containing 18 g of this resin was inserted in an extracorporeal circuit. This chloride charged resin achieved uptake of HCO3- ions, and elution of Cl- ions. The electrolytic balance was fully restored after 10 min of treatment.

Alkalosis↗
PubMed1991

Validity of flow cytometry for cross-match evaluation in clinical renal transplantation.

This paper reports a 2-year experience of more than 5,000 cross-match tests for renal transplantation. Tests were performed by means of both standard light microscopy and an innovatory method based on flow cytometry, an up-to-date investigative technique for computerized analysis of individual cell characteristics. Flow cytometry allowed a better detection of weak positive reactions (false-negative cross-matches) than light microscopy, thus reducing the risk of selecting candidates with donor presensitization. Transplant clinical outcome supported the value of this original and advanced technological method.

Antibodies↗
PubMed1991

Cellular immunology in regular dialysis: a biological model for biocompatibility evaluation.

Cellular immunity represents an interesting biological model for biocompatibility evaluation of artificial materials owing to its sensitivity to contact with the external environment and its capability of modulating response reactions to foreign agents. Advanced methodologies such as flow cytometry and the immunoenzyme techniques in particular have given new insights into lymphocyte structure and functions, enabling analysis of the in vivo modification of these cells. By means of these sophisticated techniques we investigated lymphocyte activation and proliferation during one single haemodialysis session. Findings clearly show that increases in HLA antigen density (class I and II), DNA synthesis, and interleukin-2 receptor serum concentration (Il-2R) take place during the dialysis procedure, and reach their maximum during the first hour of extracorporeal circulation. The relationship between dialysis procedure and cellular immunity appears noticeable and is of potential value in the evaluation and quantification of the biocompatibility of different dialysis membranes.

Adult↗
PubMed1986

Use of defibrotide in renal transplantation in man.

In transplanted patients graft rejection is the most frequent complication in the first year after surgery. Vascular lesions (necrosis, intimal proliferation, thrombosis) are signs of poor prognosis and lead to irreversible loss of renal function and graft removal in most cases. The problem of vascular rejection is still not solved and the results of therapy unsatisfactory, both because of inadequacy of diagnosis and/or inadequacy of available therapy. The role of prevention, very likely the best approach, is still sub judice. In an attempt to explore the validity of prevention, 22 transplanted patients (group A) were given a new antithrombotic agent (defibrotide) immediately after surgery, and the results were compared with those of a well-matched group of 30 patients on dipyridamole (group B). Follow-up lasted 6-19 months (mean 9.9) for group A; 5-21 months (mean 12) for group B. In group A, 8 patients (36%) had rejection episodes. Antirejection therapy was followed by recovery of renal function in all cases. In group B, 9 patients (29%) had rejection crises and graft removal was necessary in 7 instances due to severe vascular lesions. At the end of follow-up, all patients treated with defibrotide had normally functioning grafts: among the 30 patients on dipyridamole, 22 (73%) had satisfactory graft function.

Clinical Trials as Topic↗
PubMed1986

Biocompatibility of charcoal hemoperfusion. Effects of long-term treatment on lymphocyte characteristics and function.

Biocompatibility of charcoal hemoperfusion was studied in a group of 15 uremic patients, evaluating the effects of long-term treatment on some structural and functional parameters of circulating lymphocytes: in vivo distribution of T-cell subsets; surface T3, T4 and T8 antigen expression, in vivo and in vitro DNA synthesis. A comparative analysis was performed with patients on conventional dialysis using cuprophan membranes.

Antigens, Surface↗