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Biomedical subjects

G Piccoli

Publications and source records attributed to G Piccoli.

At least 109 records · Page 6Linked to original sources
PubMed1993

[Abnormal erythrocyte sodium transport in patients with adult polycystic kidney and hypertension].

The aim of this work was to evaluate the intracellular Na concentration, the passive Na permeability and the activity of Na, K pump, Na, K cotransport, Na, Li countertransport in the red cells of patients with autosomal dominant polycystic kidney disease (ADPKD) in relationship with their blood pressure status. Sixteen patients with ADPKD and normal renal function (6 males, 10 females, median age 31.5 years, range 20-42 years) and twenty healthy controls (10 males, 10 females, median age 30 years, range 23-47 years) were studied. Eight ADPKD were hypertensive. The rate constant of ouabain-sensitive Na efflux was lower in hypertensive than in normotensive ADPKD patients. The activity of Na,Li countertransport was significantly higher in hypertensive ADPKD patients than in both normotensive patients and control subjects. A significant inverse correlation was found between Na,Li countertransport activity and the rate constant of ouabain-sensitive Na efflux in fresh red cells (rho = 0.62; p = 0.016). Hypertension in patients with ADPKD and normal renal function is associated with abnormalities of red cell sodium transport: an increase of Na,Li countertransport, possibly primitive, and a reduction of Na,K pump in fresh cells, possibly secondary to a circulating inhibitor.

Adult↗
PubMed1993

Death in conditions of cachexia: the price for the dialysis treatment of the elderly?

Death in conditions of cachexia is increasing in potential dialysis patients, as treated cohorts are aging, the mean age of new patients increased and access to treatment is unlimited. The present study analyzes the clinical features of 417 deaths in conditions of cachexia recorded in 1981 to 1990 in the Dialysis and Transplantation Registry of a northern Italian region, Piedmont (about 4,400,000 inhabitants, 20 dialysis centers; 4,734 patients on file at December 31, 1990; yearly information on 100% of the cases). Death in conditions of cachexia increased from 105 cases in the first four years taken into account (1981 to 1984), to 107 in the last two years (1989 to 1990). Prevalence is higher in the elderly (85% of the death over age 60). Most patients (90.5%) were at high clinical risk. To assess whether the frequency of this diagnosis reflected the wide acceptance of elderly patients for dialysis and was a marked of vascular disease, a specific inquiry was conducted about 107 cachectic deaths recorded from 1989 to 1990: 82.5% of the patients had diffused vascular disease, 11.5% were already cachectic when dialysis was initiated, and 66% were in cachexia at least six months before death. Since mean age of patients dying in condition of cachexia increased from 68.8 in the period of 1981 to 1984 to 70.3 years in 1989 to 1990, and mean time on dialysis from 2.8 years in 1981 to 1984 to 70.3 years in 1989 to 1990, the higher prevalence is not likely to be due to lack of care of elderly patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Aggregation of erythrocyte sodium/lithium countertransport activity in families of patients with immunoglobulin A nephropathy.

1. We evaluated the inheritance of erythrocyte Na+/Li+ countertransport activity in IgA nephropathy by assessing this parameter in 19 patients with biopsy-proven IgA nephropathy and in their 53 relatives (32 parents and 21 siblings). The possible use of erythrocyte Na+/Li+ countertransport activity as a marker of poor prognosis was also evaluated. 2. A significant correlation was found between 'familial' and proband Na+/Li+ countertransport activity, but not between that of spouses. 3. Mean blood pressure, although within the normal range, and Na+/Li+ countertransport activity were significantly higher in patients with proteinuria than in those without proteinuria. 4. Parents of proteinuric patients had a higher Na+/Li+ countertransport activity than parents of non-proteinuric patients. 5. In IgA nephropathy the inheritance of erythrocyte Na+/Li+ countertransport activity was preserved. Therefore genetic factors could play a role in the non-immunological progression of IgA nephropathy.

Adolescent↗
PubMed1992

High resolution of multiple forms of red blood cell enzymes using a Toyopearl DEAE 650 S.

We have investigated a new anion exchange chromatographic support (Toyopearl DEAE 650 S) which simultaneously allows easily to remove hemoglobin from hemolysates and to obtain a very high resolution of enzymes present in multiple forms. The results obtained are better than those obtainable using an anion-exchange HPLC column. The data obtained at analytical level suggest a wider use of this new matrix also for preparative purposes without significant changes in the resolution.

Animals↗
PubMed1992

Preparative purification of pig red blood cell hexokinase type III using a new efficient chromatographic support.

In this paper we report the purification of pig erythrocyte hexokinase type III, at preparative level, using 52 liters of starting material (hemolysate). This was possible using a new efficient anion exchanger support, the Toyopearl DEAE 650 M which allows completely to change the strategy of removing hemoglobin from hemolysates, permitting to handle large amounts of starting material and reducing work would have required months using conventional anion exchanger supports, to only 2-3 days. Furthermore, we have tested the binding of other red blood cell enzymes to the Toyopearl DEAE 650 M, showing a wider potential use of this chromatographic support for their purification at a preparative level.

Animals↗
PubMed1992

Prospective study on captopril renography in hypertensive patients.

Six hundred and sixty-seven hypertensive patients were analyzed by captopril-enhanced scintigraphy. If time to reach maximal activity (Tmax) was > or = 5 min using 99mTc-diethylenetriaminepentaacetic acid (DTPA) or > or = 3 min with 123I-o-iodohippurate (OIH) and 99mTc-mercaptoacetyltriglycine (MAG3) and washout time > or = 15 min, a control study with nifedipine was performed. If the difference between Tmax under captopril and nifedipine premedication was > or = 5 min with 99mTc-DTPA or > or = 3 min with 123I-OIH and 99mTc-MAG3, the renogram was defined highly suggestive of renovascular hypertension. In the evaluation of bilateral abnormalities an additional parameter was considered, i.e. the presence of functional asymmetry of the emuntories susceptible of partial reversal in the control study under nifedipine. Based on these criteria, 58 out of 667 (8.7%) scintigrams were found to be abnormal. Thirty-five of these 58 patients and 32 of the remaining 609 scintigraphically negative cases underwent additional arteriographic examination. A renal vascular stenosis > or = 50% was found in 33 out of 35 (94.2%) patients with positive scintigraphy and in 3 out of 32 patients with negative scintigraphy. By examining results of the 67 patients undergoing arteriography, the sensitivity of captopril-enhanced scintigraphy was estimated to be 91.6%, with a specificity of 93.5%, an accuracy of 92.5%, and predictive values of a positive or negative result of 94.2 and 90.6%, respectively. By restricting analysis to bilateral stenosis, sensitivity was found to be 76.9%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

[Heart valve involvement in systemic lupus erythematosus: an echocardiographic study].

The purpose of this study was to evaluate the spectrum of morphologic and functional cardiac involvement in a selected population of patients with systemic lupus erythematosus (SLE) by means of echocardiography. Thirteen patients (2 male and 11 female) affected by SLE, mean age 41.9 years (range, 21-64), underwent M-Mode, two-dimensional and Doppler echocardiography. Eleven patients had renal disease and 3 of them were undergoing dialysis. One patient had findings of active disease. Six patients had systemic hypertension. None had a history suggestive of rheumatic fever or infective endocarditis. At echocardiographic study nine patients demonstrated findings of valvular involvement. These alterations were defined, according to the echocardiographic features, in two types: vegetation (verrucous Libman-Sacks endocarditis) and thickening. Vegetations were present in 6 patients, involving the mitral valve in all six and the aortic valve in three. The mitral valve vegetations were more frequent on the subannular portion of the posterior leaflet. Seven patients had valvular thickening: involvement of both mitral and aortic valve was present in five, and isolated mitral or aortic valve lesions in the remaining two patients. Combined valvular vegetation and thickening were observed in 4 patients. Eight patients had mild valvular dysfunction on Doppler examination: five isolated mitral regurgitation, two combined mitral and aortic regurgitation and one combined mitral stenosis and regurgitation. In agreement with previous reports, our study shows that valvular involvement in SLE is relatively frequent. Echocardiography can identify additional patterns of valvular lesions different from the known "verrucous Libman-Sacks endocarditis". The degree of valvular dysfunction is not important.

Adult↗
PubMed1992

[Erythrocyte sodium-lithium countertransport in diabetic children: 12 months development and relationship with familial hypertension].

It has been suggested that an increased erythrocyte Na-Li countertransport (Na-Li CNT) rate in patients with IDDM is associated to the risk of developing diabetic nephropathy. Little is known, however, about the possible influence of metabolic control on Na-Li activity. Aims of the study were to evaluate Na-Li CNT at the onset of IDDM and during the remission phase and its relationship with some clinical and metabolic parameters. Twelve insulin-dependent diabetic children (6 males, 6 females; mean age 10 +/- 0.6 years) were studied at the onset and 1, 4, 12 months after the diagnosis; 6 of them had a family history of hypertension. Twelve healthy children (6 males, 6 females; mean age 12 +/- 0.3 years) served as controls. As compared to control subjects (212 +/- 24 mumol/l RBC/h), red cell Na-Li countertransport activity of diabetic children was significantly higher at the onset (354 +/- 31 mumol/l RBC/h) of IDDM and at the first month (348 +/- 36 mumol/l RBC/h). Red cell Na-Li countertransport activity returned toward normal range at the fourth (239 +/- 33 mumol/l RBC/h) and twelfth month (162 +/- 34 mumol/l RBC/h). No correlation was found between the values of red cell Na-Li countertransport activity and those of clinical and biochemical parameters at any time. Patients with hypertensive relatives showed at baseline evaluation a significantly higher red cell Na-Li countertransport activity than those without (436 +/- 28 vs 273 +/- 34 mumol/l RBC/h; p < 0.002). This difference, although not statistically significant, was still evident at the late follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)

Antiporters↗
PubMed1991

Free radicals promote "in vitro" a different intracellular decay of rabbit reticulocyte and erythrocyte glycolytic enzymes.

Rabbit red blood cells (RBC) were exposed in vitro to an oxygen-radical-generating system represented by iron and ascorbic acid. Under these experimental conditions we have investigated the effect of this system on some intracellular rabbit reticulocyte and erythrocyte enzymes. The results obtained have shown a pronounced decay of hexokinase activity both in the erythrocytes and reticulocytes when exposed to these radical species. We have found that the amount of hexokinase inactivated is at least three times higher in a blood sample with a percentage of reticulocytes of 50-60%. This different behaviour of the hexokinase decay in the erythrocytes and reticulocytes could be due to its different intracellular distribution related to the two distinct cells. In addition we have evaluated some important intracellular compounds involved in maintaining the redox and the energetic state of the cell such as the reduced glutathione and the adenine nucleotides and their degradation products, in order to understand if there is any correlation between the hexokinase decay and a change concerning the metabolic conditions of the rabbit reticulocytes and erythrocytes exposed to free radicals.

Animals↗
PubMed1991

The fate of aggregated immunoglobulin A injected in IgA nephropathy patients and healthy controls.

Organ uptake of IgA-containing immunologically active material was studied in humans by intravenous (IV) injection of 131I-labeled heat-aggregated human secretory IgA (HAS-IgA) in nine patients affected by primary IgA nephropathy and 10 normal volunteers. Aggregated secretory IgA was found to be removed almost exclusively by the liver. The peak activity in liver was reached at 21.1 minutes (range, 18 to 26 minutes) in patients and 19 minutes (range, 14 to 22 minutes) in controls. The rate of increase of liver radioactivity was found to be significantly slower in patients (with a mean slope of 5.0; range, 3.4 to 7.1 v 7.6, 5.6 to 11.4; P less than 0.02). The mean liver to precordium ratio at the peak time was significantly lower in patients (mean value, 2.3; range, 1.9 to 3.1) compared with controls (mean value, 3.3; range, 2.4 to 4.0) (P less than 0.02). These data confirm the pivotal role of the liver in the removal of aggregated IgA in humans and the defective clearance capacity of this test probe in IgA nephropathy patients.

Adult↗
PubMed1991

IgA antibodies to dietary antigens and lectin-binding IgA in sera from Italian, Australian, and Japanese IgA nephropathy patients.

We studied serum IgA as antibodies to dietary antigens (Ag), as lectin-binding molecules, and as conglutinin-binding immune complexes (IgAIC) in people from geographical areas in which IgA nephropathy (IgAGN) is particularly frequent. Sera from 63 Italian, 21 Australian, and 25 Japanese patients affected by IgAGN and 24 Italian, 20 Australian, and 40 Japanese healthy controls were studied. Increased values of IgAIC were detected in 42.8% of Italian patients, while only in 23.8% and 8% of Australian and Japanese patients, respectively. Mean values were significantly increased only in Italian patients (P less than 0.0001). Positive values of IgA antibodies against dietary Ag had variable prevalences, but again Italian patients showed the highest frequency, from 19% to 28.5% versus 0 to 38% in Australians and 0 to 16% in Japanese. Mean values of these antibodies were not significantly increased in any patient groups in comparison to the corresponding healthy populations. However, patients with elevated values of IgAIC had significantly higher serum concentrations of antibodies to alimentary components and a linear correlation was found between IgAIC and some IgA antibodies to food components. The relationship between these two series of data was particularly evident for Italian and Australian IgAGN patients. Moreover, the patients with positive data tended to have a cluster of increased levels of IgA antibodies against several alimentary Ag at the same time. A linear correlation was evident between values of IgA antibodies to gluten fractions and to heterologous albumins. None of these correlations was evident among healthy controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Increased sodium-lithium countertransport activity in red cells of IgA nephropathy patients.

The aim of this work was to analyze Na,Li countertransport activity in the erythrocytes from patients with IgA nephropathy, in relationship with their blood pressure status and lipid profile. Forty-nine patients (32 males, 17 females) with biopsy-proven IgA nephropathy and without significant impairment of renal function (serum creatinine less than or equal to 1.4 mg/dl) and 36 normal subjects (21 males, 15 females) were evaluated. Twenty-nine patients with IgA nephropathy were normotensive and 20 hypertensive (diastolic pressure greater than or equal to 95 mm Hg or treated by antihypertensive drugs). Na,Li countertransport was significantly higher in red cells from hypertensive than from normotensive patients (P = 0.002) and normal subjects (P = 0.0001), (values respectively 309 +/- 17; 241 +/- 12 and 211 +/- 11 mumol/liter RBC/hr); normotensive patients with IgA nephropathy did not differ from controls regarding the Na,Li countertransport rate. A multiple stepwise logistic regression analysis with blood pressure status as the dependent variable and Na,Li countertransport activity, age, serum creatinine, proteinuria, cholesterol, triglycerides, plasma potassium and time from onset as independent variables, indicated an independent significant association for Na,Li countertransport (P = 0.002) proteinuria (P = 0.006), plasma potassium (P = 0.006) and age (P = 0.029). Other tested variables were not independently related to blood pressure status. Hyperlipidemic patients (plasma total cholesterol concentration greater than 200 mg/dl and/or plasma triglycerides greater than 172 mg/dl) had an erythrocyte Na,Li countertransport activity significantly higher than normolipidemic (P = 0.005) and controls (P = 0.001) (values respectively 295 +/- 14; 226 +/- 12 and 211 +/- 11 mumol/liter RBC/hr).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Classic and perinuclear anti-neutrophil cytoplasm antibodies and antimyeloperoxidase antibodies in rapidly progressive glomerulonephritis.

Classic anti-neutrophil cytoplasm antibodies (cANCA), perinuclear ANCA (pANCA) and antibodies directed against myeloperoxidase (MPO-Ab) were evaluated in 25 patients with either idiopathic or secondary rapidly progressive glomerulonephritis (RPGN). While cANCA were found almost exclusively in Wegener's granulomatosis, pANCA were detectable in several disorders, including microscopic polyarteritis (mPA), but also idiopathic RPGN. MPO-Ab were frequently found in sera from patients with all types of idiopathic but not of secondary RPGN. These results support the hypothesis that some cases of RPGN are early or limited forms of systematic vasculitis. We then looked for the presence of IgA-ANCA in Henoch-Schoenlein purpura (HSP): we found IgA-ANCA with immunoenzymatic assay but not with immunofluorescence in HSP, in primary IgA-GN and in membranous GN as well, thus suggesting the poor specificity of this type of ANCA. The possible pathologic implications of ANCA were examined in vitro. Serum samples from several patients with ANCA were assessed for their capacity to enhance chemiluminescence generation from resting or PMA-stimulated macrophages. Sera from RPGN and mPA patients displaying anti-MPO activity induced granulocytes to enhance the production of oxygen free radicals, thus suggesting a phlogistic effect of MPO-Ab positive sera.

Adult↗
PubMed1991

What is the role of sensitization in uremic pruritus? An allergologic study.

Patch tests were carried out to evaluate the presence of a sensitization to some components of dialytic circuits in 17 uremic patients complaining of pruritus of unknown origin. Fragments of different dialyzer membranes, of tubing sets, of dialyzer membranes recently resterilized with ethylene oxide and the International Contact Dermatitis Research Group standard series substances were tested. Neither patients nor healthy subjects reacted positively to patch tests, which leads us to question the role of contact allergy in the determination of uremic pruritus.

Adult↗