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Biomedical subjects

S Stefoni

Publications and source records attributed to S Stefoni.

At least 163 records · Page 9Linked to original sources
PubMedDate not supplied

Anticoagulation therapy for the prevention of hemodialysis tunneled cuffed catheters (TCC) thrombosis.

BACKGROUND: Chronic oral anticoagulation is currently used to avoid thrombosis and the malfunction of tunneled cuffed catheters (TCCs) for hemodialysis (HD). The aim of the study was to assess the efficacy of early warfarin administration, after TCC placement, in comparison to its administration after the first thrombosis or malfunction event of the TCC. PATIENTS AND METHODS: One hundred and forty-four chronic dialysis patients, who underwent TCC placement between June 2001 and June 2005, were randomized into two groups: 81 patients, group A, started oral anticoagulation 12 hr after the TCC placement (target international normalized ratio (INR) 1.8-2.5), in association with ticlopidine 250 mg/die; 63 patients, group B, started warfarin after the first thrombosis/malfunction episode (target INR 1.8-2.5) in association with ticlopidine 250 mg/die. The efficacy of oral anticoagulation therapy in preventing TCC thrombotic complications was evaluated in a 12-month follow-up period, after TCC placement, in terms of: a) the number of patients with thrombotic-malfunction events; b) the number of thrombotic-malfunction events with urokinase infusion (events/patient/year); c) intradialytic blood flow rate (BFR, ml/min); d) negative blood pressure (BP) from the arterial line of the TCC (AP, mmHg); e) positive BP, in the extracorporeal circuit from the venous line (VP, mmHg); and f) bleeding complications. RESULTS: Ten patients (12%) in group A showed TCC thrombosis/malfunction vs. 33 patients (52%) in group B (p < 0.01). In group A, 0.16 events of thrombosis/malfunction per patient/year vs. 1.65 in group B (p < 0.001) were ob-served. BFR was respectively 305 +/- 34 vs. 246 +/- 42 ml/min (p < 0.001). AP was -124 +/- 13 in group A vs. -174 +/- 21 mmHg in group B (p < 0.05). VP was 112 +/- 28 in group A vs. 168 +/- 41 mmHg in group B (p < 0.05). No patient showed any bleeding events. CONCLUSIONS: Early warfarin therapy allows a significant reduction in TCC thrombotic complications and an improvement in both arterial and venous fluxes in comparison with the same therapy administered after the first TCC thrombotic/malfunction event. This therapy did not induce any bleeding complications in the patients included in the study.

Administration, Oral↗
PubMedDate not supplied

Reduced albuminuria after dietary protein restriction in insulin-dependent diabetic patients with clinical nephropathy.

Recent clinical investigations have demonstrated that an early restriction of dietary protein intake may reduce the rate of progression of chronic renal failure in humans. In this study the effects of a restricted-protein diet on kidney function in type I diabetic patients with clinical nephropathy were evaluated. Sixteen patients (9 men, 7 women) with mean age 37.1 +/- 9.8 yr, mean duration of diabetes 17.7 +/- 6.6 yr, proteinuria greater than 0.5 g/24 h, and serum creatinine concentration of 0.7-1.9 mg/dl were studied. Patients were randomly divided into two groups. The low-protein diet (LPD) group comprised seven patients who were kept for 4.5 +/- 1 mo on a diet containing 0.71 +/- 0.12 g X kg-1 X day-1 protein. The normal-protein diet (NPD) group comprised nine patients as controls maintained for 11.7 +/- 7 mo on their usual diabetic diet containing 1.44 +/- 0.12 g X kg-1 X day-1 protein. All patients were studied every 1-2 mo. Metabolic control was assessed by evaluation of 5-8 blood glucose determinations/day and by glycosylated hemoglobin, whereas renal function was evaluated by albumin, IgG and beta 2-microglobulin urinary excretion rates, serum creatinine concentration, and creatinine clearance. At each visit, serum concentrations of total protein, albumin, phosphate, calcium, and electrolytes and weight and blood pressure were also measured. A significant reduction (434 +/- 244 to 205 +/- 212 micrograms/min, mean +/- SD) in albumin excretion rate was found in all LPD patients after dietary protein restriction, with a significant reincrease (689 +/- 201 micrograms/min) in the same patients several months after interruption of diet.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Kidney function after improved metabolic control in newly diagnosed diabetes and in diabetic patients with nephropathy.

To evaluate the effect of improved metabolic control on kidney function, urinary excretion rate of beta-2-microglobulin, lysozyme, and gamma-glutamyltransferase were evaluated in nine poorly controlled, newly diagnosed diabetic patients before and during treatment. In six poorly controlled insulin-dependent nephropathic diabetic patients, besides the parameters cited above, urinary albumin excretion rate and IgG/transferrin clearance ratio were further investigated to estimate the permeability and the selectivity of glomerular barrier during conventional treatment and after improvement of the metabolic control by a glucose-controlled insulin infusion system (GCIIS). The improved glycemic control resulted in a significant reduction of urinary beta-2-microglobulin and lysozyme excretion in all diabetic patients. Significant decreases of urinary albumin excretion and of IgG/transferrin clearance ratio (indicating a more selective proteinuria) during strict metabolic control were also observed in nephropathic diabetic patients. The reduction of urinary beta-2-microglobulin and lysozyme excretion indicates that a tubular reabsorptive dysfunction, reversible with the amelioration of glycemic control, can be observed in poorly controlled, newly diagnosed and in insulin-dependent nephropathic diabetic patients during conventional treatment. In the latter patients, the permeability and the selectivity properties of glomerular barrier also improved during GCIIS.

Adult↗
PubMedDate not supplied

[Renal transplantation and malignancies: A single-centre experience (25 years)].

BACKGROUND: The prevalence of post-transplant malignancies, in renal transplant recipients, is higher than that expected in age and sex-matched controls from the general population, and there is a markedly increased incidence of certain cancers. METHODS: In 1137 renal transplant recipients (1020 from cadaveric and 117 from living donors, M/F 771/366) performed at the S. Orsola Renal Transplantation Centre since 10/1976 to 9/2001, we studied the post-transplant cancer prevalence, the correlation between cancer prevalence and population characteristics, the risk factors (smoke, cancer history, positive HBsAg and antiHCV infection) and the immunosuppressive therapy. RESULTS AND CONCLUSIONS: The prevalence of malignancies was 3.86% (52 malignancies in 44 patients). The period between transplant and diagnosis of malignant disease was 59 +/- 85 months. Skin cancer was the most common (n=16; 30.7%), followed by lymphoproliferative disorders (n=8; 15.4%), Kaposi s sarcoma (n=6; 11.5%), uterine cancer (n=6; 11.5%), renal carcinoma of native kidney (n=5; 9.6%), cancer of breast/stomach/pancreas and urinary bladder (n=2; 3.8%) and other cancers (n=5; 9.6%). The mean duration of dialysis before transplantation was longer in cancer patients (41+/- 32.1 vs. 33.5 +/- 32.4 months). We found a correlation between types of malignancies and viral infection in NH-lymphoma (EBV positive 4/4) and skin cancer (HZV positive 13/16). We also detected a correlation between Aza and skin cancer (16/22) and CyA and lymphoproliferative disorders (7/8).

Adult↗
PubMedDate not supplied

[Recurrence of glomerulonephritis in transplanted kidney].

Recent advances in immunosuppressive therapy have dramatically reduced the incidence of acute rejection, thus improving graft survival. As a result, the importance of recurrence of the original nephropathy as a factor affecting the long-term outcome of the graft has grown considerably The incidence of recurrence increases with the increase in graft survival and can currently be estimated between 6 and 15% 10 years after surgery, with great variability among the different histological types of nephropathy. More than 50% of patients with recurrence experience progressive deterioration of graft function, and recurrence of the nephropathy accounts for long-term graft failure in more than 15% of cases. The original disease should be duly considered in all candidates for renal transplantation to identify patients at higher risk for recurrence and to define those treatment protocols devoted to risk reduction. Finally, the risk of disease recurrence should always be included among the parameters used in evaluating a possible transplantation from living donor.

Adult↗
PubMedDate not supplied

[Double renal transplant. Retrospective analysis of data on the patient population with double kidney transplantation in the setting of the AIRT].

BACKGROUND: The number of patients on the waiting list for renal transplantation has progressively increased in the last decade, while the number of potential donors have remained the same. The expansion of the donor pool using marginal donors may represent a possible, although partial solution to this problem. Thus, the aim of the present analysis was to evaluate the graft survival of double renal transplant from marginal donors performed within the Associazione InterRegionale Trapianti (AIRT) and to assess whether this procedure is characterized by an increase in surgical complications. PATIENTS: 79 double renal transplants were performed from January 1st 1999 to December 31st 2002 in three AIRT transplant centers (Bari, Bologna, Torino). Immunosuppressive therapy for all patients included anti-IL-2 receptor antibodies, corticosteroids, tacrolimus and mofetil micophenolate. RESULTS: Graft survival was 90% at 36 months. Acute rejection incidence was 6.4%, while the incidence of surgical complications was 16.6%. CONCLUSIONS: The present study opens new perspectives to overcome the actual shortage of donor kidneys. Indeed, the use of marginal organs for double renal transplantation not suitable for single transplantation may create an additional pool of potential donors and significantly increase the number of kidney transplants.

Aged↗
PubMedDate not supplied

[HCV+ patients on the waiting list for kidney transplantation. Retrospective analysis of data on the patient population with hepatitis C on the waiting list for kidney transplantation in the setting of the AIRT].

BACKGROUND: HCV infection in hemodialysis is still a matter of debate from an epidemiological and clinical point of view. Evaluation criteria for HCV-infected patients as transplant candidates are still not adequately standardized. Aims of the present study were to investigate: 1. the percentage of HCV positive patients on the waiting list of three Italian regions belonging to the Associazione InterRegionale Trapianti (AIRT); 2. to analyze the clinical approach in the evaluation of these patients in the attempt to define national guidelines for their pre- and post-transplant management. PATIENTS: We evaluated 2045 uremic patients on the waiting lists of four transplant centers (Bari, Bologna, Modena, Novara) belonging to AIRT at 31/12/2002. RESULTS: The overall prevalence of HCV positive patients was 14.2%, with a peak in the Puglia waiting list. The most common screening tests were AST and ALT serum levels and viral load (HCV RNA). Although there is a clear evidence that histological parameters are the main diagnostic and prognostic markers, a liver biopsy was performed in only 9.5% of patients. An even smaller percentage of HCV-infected patients underwent anti-viral therapy. CONCLUSIONS: Our retrospective analysis evidenced the need to improve common clinical strategies in approaching HCV-infected canditates to renal transplantation in the attempt to improve their post-transplant outcome.

Adult↗
PubMedDate not supplied

[Malignant neoplasia and kidney transplantation. Retrospective analysis of data on the population having kidney transplantation with de novo neoplasia in the setting of the AIRT].

BACKGROUND: In transplanted patients undergoing immunossuppressive therapy the incidence of malignant neoplasia is 3-4 times higher than in the general population. Aim of the present study was to evaluate the prevalence of different tumours and the links between modulation of immunosuppressive therapy and patient and graft survival. PATIENTS: We evaluated 2029 kidney-transplanted patients from four Transplant Centres (Bari, Bologna, Modena, Novara) belonging to the Associazione InterRegionale Trapianti (AIRT). RESULTS: The incidence of neoplastic disease after transplantation was 3.9% in our population with a median time between transplantation and clinical onset of 23 months. We demonstrated a significant difference in the geographical distribution of different tumours. We did not observe any correlation with specific immunosuppressive drugs. Finally, dramatic reduction of the immunosuppression levels did not modify either the patients' or the graft's survival. CONCLUSIONS: Several factors can influence the post-transplant onset of neoplastic diseases with immunosuppressive therapy playing a pivotal role. The implementation of a National Registry would be the first step in an attempt to optimise immunosuppression in this particular group of patient's.

Humans↗
PubMedDate not supplied

[Long-term use of Profiler in patients with dialysis intolerance: 8 months follow-up].

PURPOSE: A new method of profiled dialysis has been set up for many years in the Department of Nephrology, Dialysis and Renal Transplantation at the University of Bologna. This profiled dialysis is based on the use of a new kinetic mathematical model, in collaboration with the Faculty of Engineering at the University of Bologna, for the elaboration of individual sodium and ultrafiltration profiles. OBJECTIVE: The profiled dialysis aims are: 1) to stabilize the intradialytic blood volume, boosting the refilling of plasma water from the intracellular and the extravascular to the extracellular/intravascular compartments, to balance the ultrafiltration; 2) to counteract the disequilibrium syndrome reducing the shift of water from the extra to the intracellular compartment. The pre-dialysis elaboration of profiles is completely automatic and supported by a computerized programme, Profiler, which has been included in the software of the dialysis machine Bellco Formula 2000 Plus. METHODS: In this prospective and multicenter study, this profiled dialysis, performed according to the Profiler, was continuously applied, for an 8-month period, in a group of 13 hemodialysis (HD) patients with an intolerance to previous dialysis treatment. During the study, the following parameters were evaluated, comparatively, with the patient's basal treatment: a) sodium and water balance; b) percentage incidence of intradialytic complications such as hypotensive events, cramps, headache, and vomiting and; c) metabolic and nutritional status. RESULTS: Results evaluated in comparison with the patient's previous dialysis treatments, demonstrated: a) plasma sodium from 136.8 +/- 3 to 136.8 +/- 1.7 mEq/L (p=ns), dry body weight from 72.2 +/- 19.3 to 71.7 +/- 19.5 kg (p=ns), heart index from 3.7 +/- 0.7 to 3.1 +/- 0.5 L/min/m2 (p=ns), reactance from 5.3 +/- 15 to 4.9 +/- 11 ohm (p<0.05); b) incidence of intradialytic hypotensive events reduced from 64 to 4% (p<0.001), cramps reduced from 8 to 1% (p<0.01); c) plasma albumin from 3.5 +/- 0.2 to 3.7 +/- 0.3 g/dL (p=ns), Kt/Veq from 1.3 +/- 0.1 to 1.36 +/- 0.2 (p=ns). CONCLUSIONS: Patients treated with profiled dialysis had a higher stability of intradialytic blood pressure (BP) achieving a reduction in the incidence of disequilibrium syndrome symptoms, in comparison with previous treatment. These clinical intradialytic improvements were not correlated to clinical, instrumental or biochemical indexes of sodium-water overload nor to a worst dialysis adequacy and nutritional state.

Female↗
PubMedDate not supplied

[Therapy strategies in the prevention of chronic allograft nephropathy].

Chronic allograft nephropathy (CAN) is an anatomical and clinical alteration, characterized by proteinuria, hypertension and a progressive decline in kidney function, which begins at variable times (months, years) and can lead to the loss of the transplanted organ. CAN pathogenesis, which remains to be fully clarified, involves both immunological (early acute rejection, hyperimmunization, HLA-mismatches between donor and recipient, suboptimal immunosuppression, etc) and non-immunological factors (ischemia/reperfusion injury, reduced nephron mass, age differences between donor and recipient, dialysis time, hypertension, dislipidemia, proteinuria, etc). The possible prevention strategies for CAN consist of procedures aimed at the reduction of some potential risk factors: optimization of the conditions for organ explantation, diminution of ischemia/reperfusion injury, aggressive pharmacological treatment of acute rejection episodes, routine utilization of anti-hypertensive and hypolipidemic agents, and appropriate and rational immunosuppressive regimen. Moreover, some categories of immunosuppressive drugs, such as calcineurin inhibitors, can have a nephrotoxic effect, often regardless of therapeutic dosage. The introduction in clinical practice of novel immunosuppressive drugs with no nephrotoxicity, like mycophenolate mofetil and rapamycin, makes therapeutical strategies able to reduce the incidence of CAN feasible.

Chronic Disease↗
PubMedDate not supplied

A real-time analysis of a transplantation program with a personal computer.

This study concerns the use of commercial software (a spreadsheet combined with database and graphic functions) to analyze data on kidney transplantation. The program consists of a section containing (macro) instructions, a section for entering data, a database, a set of spreadsheets (one for each field) with which the statistical calculations and summary tables are executed, and a set of diagrams for the final visual output. Three kinds of data are made available: descriptive statistics, actuarial survival rates, and risk factor evaluation. The program can analyze the importance of the variables considered and estimate the effect of a therapeutic or diagnostic maneuver.

Computer Systems↗
PubMedDate not supplied

Comparative losses of free amino acids and their plasma variations in artificial substitutive programmes for chronic uraemia.

This study provides a comparative evaluation of the losses of free amino acids which take place in the various artificial substitutive therapies for chronic uraemia (conventional haemodialysis, haemofiltration, haemoperfusion, continuous ambulatory peritoneal dialysis, intermittent peritoneal dialysis). The highest loss was found during haemofiltration sessions, the lowest in continuous ambulatory peritoneal dialysis. The differing loss rates do not influence patients' plasma amino acid patterns either in the short or in the long term (up to 12 months). Moreover, no currently available artificial therapy can correct the basic uraemia-related alterations of plasma amino acid patterns.

Adult↗