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Biomedical subjects

R Ragni

Publications and source records attributed to R Ragni.

At least 19 recordsLinked to original sources

[Analysis of cause of death in the 1st and last periods of the Piedmontese Dialysis and Transplantation Registry].

The aim of this study is to assess the mortality causes in dialysis in the Piedmont Region, using the data of the Dialysis and Transplantation Register (DTR). Data of a 15-year use of the DTR regarding 5519 hospital dialysis admissions were considered. Mortality seems to be particularly due to cardiac causes analyzing, also the incidence of other causes of death such as: cachexia, sudden death and infection causes.

Adolescent↗

[Patients with neoplastic disease or older than 80 years of age: dialysis survival].

In several European countries, including Italy, the resident population is ageing. This process is at the basis of the progressive increase in incidence of new elderly patients starting dialysis and, to a lesser degree, of patients affected by severe comorbid conditions, such a neoplasia. The aim of the study was an analysis of the situation in Piedmont (Northern Italy, 4,400,000 inhabitants): out of 4483 new entries in 1981-1993, 192 were aged 80 years and 87 were affected by renal neoplasia or by multiple myeloma. Incidence of patients aged 80 increased throughout the period; use of high tolerance techniques increased in the meantime allowing an improvement in survival results. The high incidence of vasculopathic patients and the high rates of death from cachexia pinpoint how much still has to be done in the field of prevention, even before dialysis starts.

Age Factors↗

[Diabetes mellitus is currently one of the most frequent causes or associated causes of uremia. Data from the Piedmont registry of dialysis and transplantation (update, December 1993)].

A regular dialytic treatment of diabetic patients is until accepted from about twenty years in many areas. Aim of this work was a retrospective analysis of main clinical and survival data of diabetic patients (diabetic nephropathy or diabetes as comorbidous factor = 659 cases) admitted for dialysis in Piedmont (Northern Italy Region about 4,400,000 inhabitants) in the period 1981-1993 (functional recovery and follow-up < 1 month excluded). A progressive increment in incidence of diabetic patients was seen mostly in the aged. At 12/31/1993, 263 of 2404 patients admitted for dialysis were diabetics (10.9%); the majority of them was treated in Hospital Centers with bicarbonate haemodialysis (54.4%), while a small group was treated with CAPD (12.9%). During the years ¿80 was seen a progressive leaving of CAPD as first choice method in this population and in the last period the orienteering is the utilization of mixed methods (diffusive-convective as first choice). As regards the survival are not prominent significant differences between this cohort and the cohort affected by vasculopathy as comorbidous factor (86.2 and 54.2% in diabetics vs 78.6 and 55.2% in patients affected by vasculopathy at 1 and 3 years--p = 0.3481; patients aged 45-64 years). In conclusion the cohort of diabetic patients represent a good marker of the clinical problems of the elder population with high clinic risk, in progressive increasing in our Region.

Adult↗

[Anti-HCV antibodies in chronically dialyzed uremic patients. 1-year follow-up study].

The sera of 109 patients undergoing chronic haemodialysis treatment were reexamined after one year in order to assess changes in the anti-HVC antibody pattern in the intervening period, June 1992-June 1993. Using the ELISA II generation test, positive cases were found to have risen from 57 to 63 (from 52.3% to 57.8%); the Riba II test showed 60 positive cases (previously 52) with 3 undetermined (previously 5). The incidence of biochemical indicators of necrosis and/or cholestasis, negative in HCV patients, also presents a particular positivity (44%) in the presence of four antibody fractions. These data confirm the importance of serial determinations in anti-HCV antibody time, even if they do not correlate directly with the presence of the virus in the circulation and hence with its infecting capacity, the marker for which should be sought in the polymerase chain reaction.

Adult↗

[Choice of dialysis methods as initial substitutive treatment: trends in the last 10 years].

The authors report data from the Regional Piedmontese Registry about the evolution of choices concerning dialytic therapy in the 20 regional dialysis Units during the years 1981-1990. They confirm a scale-down of acetate dialysis that is replaced with bicarbonate dialysis; besides a limited use of convective dialysis whereas peritoneal dialysis is steady. At the same time they remark an increase in admittance to dialysis and older patients.

Adult↗

Production of tumor necrosis factor-alpha in patients on hemodiafiltration.

The systemic production of tumor necrosis factor (TNF)-alpha was evaluated in uremic patients before and after hemodiafiltration (HDF) and paired filtration dialysis (PFD) and in the interdialytic period. Both HDF and PFD were performed using polysulfone dialyzers with either standard or ultrapure dialysis fluid. TNF-alpha was quantitated by using a specific biological assay based on its cytotoxic effect on a TNF-sensitive human melanoma cell line SK-MEL-109. Postdialytic mean plasma TNF-alpha levels decreased, albeit not significantly, in regard to predialytic values. These results differ from those obtained in patients on HDF using other high-permeability membranes such as polymethylmethacrylate and polyacrylonitrile (AN 69) as recently described by us. Of interest, the adoption of ultrapure dialysis fluid resulted in a marked reduction in the interdialytic production of TNF-alpha. These results suggest that the enhanced production of TNF-alpha in patients dialyzed with high-permeability membranes is mainly dependent upon the bacteriological purity of dialysis fluid.

Adult↗

The role of intravascular coagulation in pregnancy related acute renal failure.

Pregnancy-related acute renal failure (ARF) can include reversible tubular necrosis as well as irreversible cortical necrosis. Though pathogenetic mechanism are not fully understood, disseminated intravascular coagulation (DIC) probably plays a primary role. We report 25 cases of pregnancy-related ARF: 13 were associated with preeclampsia or eclampsia and 12 with obstetric complications. The following parameters were studied: partial thromboplastin, prothrombin and thrombin time, fibrinogen, anti-thrombin III and FDP levels, platelet count, whole blood clot lysis time and area, fragmented red cells (schistocytes) in the blood smear, hemoglobin, aptoglobin and LDH concentrations. DIC was scored in arbitrary units ranging from 12 to 36 and related to the clinical picture, renal outcome and the treatment employed. Five patients had irreversible renal damage, while 19 recovered fully; one patient died and no renal histology was available. The DIC score did not seem to have a significant relation to the severity of renal damage.

Acute Kidney Injury↗

Clinical and therapeutic correlations in consumption coagulopathy of obstetric acute renal failure.

Heparin has been proposed following the supposed role of disseminated intravascular coagulation (DIC) in the pathologies associated with the consumption coagulopathies such as obstetric acute renal failure (ARF), whilst antifibrinolytic agents could be advocated to stop a simultaneous triggered fibrinolysis. Out of 26 obstetric ARF DIC may be demonstrated in 10 and supposed in 6 patients who developed severe post-partum uterine bleeding. Therapeutic schedules employing heparin or antifibrinolytic agents early post-partum do not seem to change either the behaviour of laboratory parameters (showing a DIC partial resolution within 48 hours), or heavy bleeding in respect to the patients treated with supportive therapies alone. Furthermore, heparin administered during the following days does not seem to be a crucial factor in the renal recovery, and is often followed by severe haemorrhagic complications. Fresh frozen plasma after aprotinin is able to stop bleeding in the presence of persisting signs of consumption without damaging renal recovery.

Acute Kidney Injury↗

Direct interaction between polymorphonuclear neutrophils and cuprophan membranes in a plasma-free model of dialysis.

Plasma-free, purified, normal, human polymorphonuclear neutrophils (PMN) were recirculated for 60 minutes in an experimental model of dialysis using cuprophan membranes and acetate or bicarbonate dialysate. At different time intervals, the intracellular contents of PMN-derived cationic proteins (NCP), the release of lysosyme, beta-glucuronidase and PAF as well as the occurrence of PMN and platelet aggregating activities in the supernatants were evaluated. The formation of PMN aggregates, the depletion of intracellular contents of NCP together with the release of lysosomal constituents occurred early (5-10 min) in the course of recirculation. These events were concomitant with the occurrence of PMN aggregating activity in the supernatants due to the release of NCP, as it was antagonised (30-40%) by a rabbit anti-human NCP, and to the release of PAF which also accounted for the platelet aggregating activity that was independent from both adenosine diphosphate and cyclo-oxygenase inhibitors. These data suggest that direct interaction occurs between human PMN and cuprophan in in vitro conditions in the absence of plasma factors and point to a role for cellular mediators in the pathogenesis of the intravascular alterations occurring early in haemodialysis.

Cell Aggregation↗

Hemofiltration in diabetic uremic patients.

The increasing number of Diabetic Uremic Patients (DUP) starting the substitutive treatment (ST) constitutes a difficult and often disappointing problem in terms of efforts, clinical results and side-effects. While treatment of these patients by C.A.P.D. is well documented, the adoption of Hemofiltration (HF), has been, up to now scarcely considered. In order to define the potentialities of a HF policy in the treatment of these patients, data from 6 DUP treated with postdilutional HF for a 10.6 months/patient period were collected on a multi-center basis and retrospectively examined. Good results were achieved in terms of vascular stability, control of arterial hypertension and of retinopathy, clinical complications and hospitalization rate. Although C.A.P.D. may represent a first choice treatment for DUP with residual function, satisfactory glicemic control, difficult blood access and a motivation to full autonomization, HF may constitute a logical alternative when C.A.P.D. should be unmanageable (visus impairment, history of repeated peritonitis and dismetabolism, considerable weight gain): an integration of HF and C.A.P.D. can assure PDU with a continuative treatment.

Blood↗

[Renal tolerance for aminoglycosides].

Tissue pharmakinetics, morphology of renal lesions and clinical picture of aminoglycoside-induced tubulopathy are described. Almost completely filtered by the glomerulus, they are eliminated in active form and about a third are reabsorbed along the proximal convoluted tubule, thus reaching maximum concentration in the renal cortex in the sixth hour as the drug disappears from the circulation. They are located inside the lysosomes of the convoluted tubule cells where some typical formations called myeloid bodies are present. Cellular lesions are, however, only produced by high doses after, first, clinical manifestations of tubular disturbance such as polyuria, tubular proteinuria, enzymuria, followed, if the toxic insult persists, by renal insufficiency. This can present clinically as progressive renal function deterioration dependent on the dose-time factor. This deterioration is usually not oliguric and it may also present as a sudden oliguric renal insufficiency. The now fully documented risk factors are discussed as well as the duration of treatment (not more than 11 days), the dosage (3 mg/kg/die), the dosage intervals, the age factor (the elderly being shown to be more highly sensitive to the drug), the association with other aminoglycosides or diuretics or cephalosporin. It is very important to diagnose already existing nephropathies or renal insufficiency, in which case dosages must be appropriately reduced. The nephrological history of the patient and control of urea and creatinine clearances before the start of treatment (in addition, obviously, to functional control of the eighth pair of cranial nerves) are essential for all patients receiving courses of aminoglycoside therapy. It is also necessary to check renal function by daily measurements of creatinaemia and urine. These precautions are valid for all aminoglycosides including those that have come on to the market most recently.

Acute Kidney Injury↗

[Renal tubular damage after rapid intravenous contrast study with iopamidol].

Reference is made to results obtained in 53 nephropathics in the study of urinary elimination of alphaglycosidase and lysozyme before and after rapid contrastography with sodium and meglumine diatrizoate and with iopamidol. A statistically significant difference in alphaglycosidase was evident with both media, whereas no change was noted for lysozyme. As far as the evaluation of alphaglycosidase was concerned, the tubular alteration induced by each medium was the same in terms of statistical comparison of the mean differences before and after urography.

Contrast Media↗

Heparin is unable to prevent contact activation by three different membranes.

In spite of the anticoagulant activity of heparin platelet deposition and contact activation of coagulation occurs during dialysis. We have studied platelet counts, fibrinogen, platelet factor 4, beta-thromboglobulin, thromboxane B2, FRA, C3d and kallikrein values, whole blood and euglobulin lysis times and membrane areas in haemodialysis using cuprophan and cellulose acetate and in haemofiltration with polyacrilonitrile. Deposits on all the three membranes included leucocytes, platelets and fibrin. The coagulation and fibrinolytic systems are activated more intensively with cellulose acetate and more prolongedly with polyacrilonitrile. Platelet factor 4 and beta-thromboglobulin increases suggest platelet activation, only partially dependent on arachidonic acid-mediated pathway as thromboxane B2 is not increased. The complement system is activated whereas serum kallikrein does not alter, suggesting that platelets rather than factor XII are crucial in contact activation.

Adolescent↗