PubMed Health⌕ Search

Biomedical subjects

G Passavanti

Publications and source records attributed to G Passavanti.

At least 19 recordsLinked to original sources
PubMed2003

Nitrendipine and amlodipine mimic the acute effects of enalapril on renal haemodynamics and reduce glomerular hyperfiltration in patients with chronic kidney disease.

Antihypertensive drugs may have an important effect on glomerular haemodynamics. In chronic nephropathy patients, we compared the effect on glomerular haemodynamics of two second-generation dihydropyridinic agents, nitrendipine and amlodipine, with a first generation dihydropyridinic agent and an ACE-inhibitor, enalapril. In all, 32 patients (pts), divided into four groups, received the different drugs: ENA (enalapril, eight pts), NIF (nifedipine, eight pts), NIT (nitrendipine, eight pts) AML (amlodipine, eight pts). The study assessed the effect on glomerular haemodynamics of a single administration of the test drug in baseline conditions and in glomerular hyperfiltration experimentally induced by amino-acid infusion. The glomerular filtration rate (GFR, measured by inulin clearance), effective renal plasma flow (ERPF, measured by p-aminohippurate clearance), renal vascular resistances (RVR) and filtration fraction (FF) were assessed. Administration of AML and NIT test dose reduced FF, as did ENA, but not NIF, in both baseline (AML: P=0.005; NIT: P=0.02; ENA: P=0.007) and glomerular hyperfiltration conditions (AML: P=0.0003; NIT: P=0.03; ENA: P=0.00006). In baseline conditions, only ENA resulted in a significant drop in the GFR (P=0.008), while NIF, NIT and AML induced a significant increase (P=0.003, 0.03, 0.0001, respectively). However, in hyperfiltration conditions, NIT (0.08) and AML (0.00003) caused a decrease in the GFR, as did ENA (0.0003) but not NIF. In all the experimental conditions, a RVR reduction and an ERPF increase were observed. Single dose of NIT and AML were effective in attenuating the effect of amino-acid infusion on glomerular filtration, similar to ENA; this effect of NIT and AML on the glomerular filtration rate is not observed under basal conditions.

Adult↗
PubMed2003

A rare case of central post-gravid diabetes insipidus.

Central diabetes insipidus (CDI) arising in the puerperal period has been attributed mainly to Sheehan's syndrome or to lymphocytic infundibulo-neurohypophysitis. We report the case of a 24-year-old woman who came to our observation for the appearance, 3 weeks after a normal delivery, of a polyuric-polydipsic syndrome. Measurements of urinary volumes, plasma osmolality and urinary osmolality, in conditions of free water intake, water deprivation and a water deprivation-vasopressin administration test, demonstrated CDI. Brain magnetic resonance imaging showed a normal morphology of the adenohypophysis and total absence of the neurohypophysis. Assays of the pituitary hormones were found to be within normal limits. These results, incompatible with a diagnosis of Sheehan's syndrome and lymphocytic infundibulo-neurohypophysis, excluded all the other known causes of acquired CDI. Our diagnosis was therefore of post-gravid idiopathic CDI. Thus, it is possible that in the puerperal period other diseases of the posterior hypophysis may develop, of unknown etiopathogenesis but equally responsible for CDI.

Adult↗
PubMed1999

Tissular oxygenation and erythrocyte deformability in haemodialyzed patients using different dialytic membranes.

We studied the effect of some dialytic membrane on tissular oxygenation (TO) and erythrocyte deformability (ED). Sixteen patients (10 M and 6 F, aged 59 +/- 12 years) have been submitted to bicarbonate dialysis (BD) and subdivided into four groups (GR) of 4 patients each: GR 1 (hemophan membrane, 35 BD), GR 2 (polyacrylonitrile, PAN AN 69, 42 BD), GR 3 (polysulphone, 38 BD) and GR 4 (polycarbonate, 37 BD). The TO has been detected with the transcutaneous oxygen pressure (Tc pO2) using a transcutaneous oxymeter and the ED has been evaluated with the EMI (Erythrocyte Morphometric Index), which results from the ratio between deformable erythrocytes (bowl shape) and rigid erythrocytes (discocyte shape), for every 100 red cells fixed in vitro with 0.3% glutaraldehyde. The ED was also evaluated using a laser instrument: Laser Optical Rotational Cell Analyser. During BD was observed a significant decrease of Tc pO2 in the 1st hour only in the 1st and 2nd GR and, in contrast with results obtained in the 3rd and 4th GR, in the same GRs the EMI showed a significant reduction of ED at the end of BD. Finally the LORCA results, showing a significant decrease of ED only in the 1st and 2nd GR, confirmed the data obtained with EMI. In conclusion, our study has suggested that hemophan and PAN AN 69 are less biocompatible than polysulphone and polycarbonate membranes according to effects on ED and TO.

Blood Gas Monitoring, Transcutaneous↗
PubMed1992

Chronic glomerulonephritis and exposure to solvents: a case-referent study.

To evaluate the risk of chronic glomerulonephritis in subjects exposed to solvent vapours, a case-referent study was carried out. The case group, including 60 patients (44 men and 16 women) with non-systemic chronic glomerulonephritis, established by biopsy, was compared with 120 control subjects (60 patients with traumatic fractures and 60 patients affected by nephrolithiasis) matched by sex and age. Information on occupational and non-occupational exposure to solvent was obtained by questionnaire. The exposure scores drawn from questionnaires were significantly higher in the case group than in the referent groups for both total and occupational solvent exposure. No significant differences in non-occupational exposure were found. The odds ratio of chronic glomerulonephritis for occupationally exposed (score > 0) was 3.9 (95% confidence interval (95% CI) 1.64-8.33). When IgA nephropathy patients (n = 27) were separately evaluated, an increased risk was found for both total and occupational exposure. Using a logistic regression model, a dose-response effect for occupational exposure was seen. The results support the hypothesis that chronic glomerulonephritis may be related to environmental factors such as exposure to hydrocarbons.

Adolescent↗
PubMed1990

[Permeability of dialysis membranes for endotoxins. Clinical and experimental results].

In the presented investigation in 20 endotoxaemic patients 70 haemodialyses were performed. It was revealed that the prehaemodialyzation LAL positivity in 50 haemodialyses (71%) declined, while no differences were observed in the effectiveness of cuprophan and AN 69 membranes. Research in vitro revealed that LAL positivity of blood which contains endotoxins and is subjected for 300 minutes to haemofiltration remains unaltered; in ultrafiltrates LAL is permanently negative. This is due to a mechanism of endotoxin fragmentation as a result of interaction of blood and membrane. Moreover, the LAL positivity of blood containing lipid A declines gradually when subjected to 80 minutes haemofiltration; the dialyzation permeability for lipid A is then proved by the fact that LAL positivity appears in the ultrafiltrate. From the submitted results ensues that reduction of LAL positivity by haemodialysis occurs as a result of elimination of filtrable endotoxin fragments (lipid A) which are released in the body.

Acute Kidney Injury↗
PubMed1990

Pathophysiology of renal failure in obstructive jaundice.

This paper aims to consider the several factors which may participate in renal failure occurring in surgery in patients with obstructive jaundice. The role of bilirubin and bile acids and the endotoxin effects related to lipid A, the active fragment of bacterial lipopolysaccharides, have been investigated to analyze their responsibility in propensities to hypotension and to postoperative acute renal failure.

Acute Kidney Injury↗
PubMed1989

The permeability of dialytic membranes to endotoxins: clinical and experimental findings.

This study of 20 endotoxemic patients submitted to 70 hemodialyses (HD) found a reduction of the pre-HD limulus amebocyte lysate (LAL) positivity in 50 HD (71%), without appreciable differences in terms of effectiveness between cuprophan and AN 69 membranes. To define the mechanisms responsible for the reduction in LAL positivity during HD, the membranes were used in two in vitro studies, the first of which showed that the LAL positivity of blood containing lipopolysaccharide (LPS), submitted to hemofiltration (HF) for 300 min, remained unchanged and the ultrafiltrate remained constantly LAL negative. These results suggest that the reduction in LAL positivity observed in HD in vivo, an expression of reduced endotoxemia, cannot be attributed either to the filtration of the LPS as such or to its fragmentation following blood-membrane interaction into theoretically less filtrable molecules or to mechanisms of LPS adsorption on the membrane. The in vivo reduction of LAL positivity is more likely due to removal of the filtrable endotoxin fragments already released in the body, like lipid A, the biologically active component of LPS, known to react to LAL. This hypothesis was borne out by the second in vitro study, where the LAL positivity of blood containing lipid A, treated by HF for 80 min, gradually decreased, and dialytic permeability to lipid A was confirmed by the appearance of LAL positivity in the ultrafiltrate.

Clinical Trials as Topic↗
PubMed1989

Pathogenetic aspects of uremic cardiomyopathy.

We have considered just some of the many factors which may affect myocardial function, assessed by means of echocardiography, in uremic patients. Our findings support the view of a multifactorial genesis of the cardiac involvement in uremic patients.

Adult↗
PubMed1988

Endotoxemia in hemolytic uremic syndrome.

Hemolytic uremic syndrome (HUS) was diagnosed and confirmed by renal biopsy in an 18-year-old primigravida at the 13th week of pregnancy. Circulating endotoxin was detected and the endotoxemia was progressively reduced by hemodialysis (HD) performed daily from the 3rd to the 9th day of disease. Complete normalization of the renal function was observed on day 34. The authors emphasize the importance of detecting endotoxemia in HUS in order to initiate dialysis early; at the same time they also discuss the pathogenetic role of endotoxin in this disease.

Abortion, Induced↗