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Biomedical subjects

G Piccoli

Publications and source records attributed to G Piccoli.

At least 163 records · Page 9Linked to original sources
PubMed1986

[Microscopic analysis of saphenous veins used for aortocoronary bypass].

The Authors describe a study performed on a sample of 88 saphenous veins used as aorto-coronary bypass grafts. The patients underwent surgery in the Department of Cardiovascular Surgery of Ancona from Jan. 1981 to Dec. 1984. The morphological analysis (light and electron microscope) was conducted with a comparative method between two surgical techniques (ST). The first refers (Group I) to 1981-82, the second (Group II) to 1983-84. In Group I the veins were taken with a conventional surgical technique. In Group II the ST was performed using an atraumatic procedure, topic vasodilators, distension of the vein with autologous blood and driving pressure less than 150 mmHg, and storage of the vein in blood at room temperature. The results show that in Group II there is better preservation of the endothelial venous layer. The distending pressure of the venous graft (less than 150 mmHg) and prevention of venous spasm were statistically relevant (p less than 0.05). The AA. conclude that vein graft damage during surgery can be avoided by means of the following procedures: dissection of the vein with atraumatic technique; prevention of venous spasm with topic vasodilators; distension of the vein at pressure less than 150 mmHg.

Coronary Artery Bypass↗
PubMed1985

Evaluation of ouabain-insensitive red blood cell cation transport in uremic patients.

The authors present the results of a simultaneous assay of: intracellular Na+ and K+ concentrations, Na+ and K+ outward bumetanide-sensitive effluxes (Na+, K+ cotransport), Na+ efflux stimulated by extracellular Li+ (Na+, Li+ countertransport), and ouabain- and bumetanide-resistant Na+ and K+ effluxes (passive membrane permeability) performed in red blood cells from 15 uremic patients an regular hemodialysis and from 12 normal subjects, with an established flux assay. Na+ and K+ effluxes by the Na+, K+ cotransport system were significantly (p less than 0.01) lower in uremic patients then in normals (219 +/- 37 vs 82 +/- 17 mumol/l RBC/h and 251 +/- 29 vs 139 +/- 14 mumol/l RBC/h respectively). In normal subjects the bumetanide sensitive Na+ and K+ effluxes were strongly (r = 0.89; p less than 0.01) intercorrelated; and the intracellular Na+ concentration was related to the outward Na+ cotransport flux (r = 0.53; p approximately 0.05). Among uremic patients these correlations were not found. Na+ and K+ intracellular concentrations, passive Na+ and K+ permeability, and Na+, Li+ countertransport activity were not different among uremic patients and normal controls. In conclusion, in uremic dialyzed patients, red blood cell Na+, K+ cotransport activity is quite uniformly suppressed. The possible pathogenesis of this disfunction is still speculative and deserves further studies.

Adult↗
PubMed1985

Presence and origin of IgA1- and IgA2-containing circulating immune complexes in chronic alcoholic liver diseases with and without glomerulonephritis.

Levels of IgA-containing circulating immune complexes (IgAIC) and their content of IgA1 and IgA2 subclasses were determined in chronic alcoholics with various degrees of liver damage and with or without associated glomerulonephritis. In patients with chronic alcoholic liver diseases, significantly increased IgAIC mean values were found independent of the presence of renal involvement, while in chronic alcoholics without biochemical evidence of liver damage IgAIC levels were normal. Both IgA subclasses were evidenced in IgAIC with an IgA pattern similar to that found in secretions, in agreement with the impaired liver clearance of IgAIC derived from intestinal mucosa. Nevertheless, no significant correlation between IgAIC and markers of hepatocytolysis or of cholestasis was found. One cannot therefore rule out the hypothesis of increased IgA synthesis in alcoholic liver disease due to abnormal alimentary antigen challenge and pathologic lymphocytic responsiveness. Finally, high IgAIC levels were found not only in patients with IgA glomerular deposits, but also in patients without clinical evidence of renal involvement.

Adult↗
PubMed1985

In vitro study of Fc-receptor function in autoimmune diseases.

A simple test for studying in vitro Fc-receptor function of mononuclear phagocytes is described. Immune phagocytosis is analyzed as a dynamic phenomenon by using nearly pure suspensions of monocytes incubated for diverse times with autologous erythrocytes sensitized with highly purified IgG. In a series of normal volunteers and patients with vasculitis a strict correlation has been found between this in vitro assay and the measure of splenic clearance of IgG-coated red blood cells (RBC), the classical approach for studying in vivo macrophage Fc-receptor function by using sodium chromate 51Cr as tag. The use of this in vitro assay appears to be valuable mainly in cases requiring repeated measurements of Fc-receptor function for monitoring the course of disease or the effects of therapy.

Autoimmune Diseases↗
PubMed1985

Effects of an intravenous saline load on erythrocyte sodium transport in normal human subjects.

The effects of a 2 litre intravenous infusion of saline (0.9% NaCl solution) over 3 h on erythrocyte transmembrane sodium transport were studied in 12 normal human subjects. After saline infusion a significant (P less than 0.01) reduction of both outward Na+,K+ pump- and Na+,K+ cotransport-mediated Na+ effluxes was observed. The Na+,Li+ countertransport rate and the passive Na+ permeability did not change. The incubation of the subjects' erythrocytes, obtained on a separate occasion, with their own plasma taken after the saline infusion, induced an inhibition of both Na+,K+ pump and Na+,K+ cotransport outward sodium fluxes. The percentage decrease after incubation was closely correlated with the percentage reduction induced by the saline infusion in vivo (r = 0.93 for the pump and r = 0.96 for cotransport; P less than 0.01). These data suggest that extracellular fluid volume expansion affects the release of circulating factors modulating sodium transport by the Na+,K+ pump and by Na+,K+ cotransport.

Adult↗
PubMed1985

Immunological monitoring of plasma exchange in primary IgA nephropathy.

Plasma exchange (PE) has recently been proposed for primary immunoglobulin (Ig)-A nephropathy (PIgAGN) with progressive course. To develop suitable guidelines for PE in these cases, the authors evaluated the clinical usefulness of some immunological parameters in five patients with PIgAGN treated with PE combined with immunosuppressive drugs and small doses of corticosteroids. These parameters included the levels of IgA-containing immune complexes (IgAIC) by a specific conglutinin assay, the function of the mononuclear phagocyte system (MPS) by the in vivo clearance of IgG-sensitized erythrocytes, and complement activation as determined by C3d measurement. HLA types were also determined. Three patients had an acute nephritic syndrome with a rapidly progressive course, one of them showing sclerotic histologic changes. The two other cases had a relentless progression toward renal failure. In the patient with sclerotic PIgAGN, the MPS function was normal and the IgAIC and C3d levels were low throughout the treatment. In the other four cases, the high IgAIC and C3d levels and the MPS dysfunction found before treatment markedly improved after several PEs. The immunological parameters remained normal during the post-PE follow-up in two cases with acute nephritic syndrome and rapidly progressive course, but worsened again in two cases with a relentless course, particularly in one who possessed the B8/DR3 HLA type. Immunological monitoring including IgAIC, C3d, and MPS function is proposed, in addition to histological and clinical evaluation, as a guideline for PE in PIgAGN with evolving course.

Adolescent↗
PubMed1985

Plasmapheresis in a patient with rapidly progressive idiopathic IgA nephropathy: removal of IgA-containing circulating immune complexes and clinical recovery.

Primary IgA nephropathy is generally considered a benign disease, but progression to renal failure is not uncommon and a rapidly progressive course is observed in some cases, especially when extensive epithelial crescents are present. Circulating IgA-containing immune complexes (IgAIC) seem to play the most important pathogenetical role, hence the authors adopted plasmapheretic treatment in association with immunosuppressive drugs for 1 patient affected by primary IgA nephritis, with florid crescents and progressive renal failure. IgAIC decreased significantly after each plasma exchange and finally returned to normal values; over the same period urinary protein loss and heavy microscopic hematuria gradually disappeared and renal function was completely recovered.

Antigen-Antibody Complex↗
PubMed1985

Acute effects of hemodialysis on erythrocyte sodium fluxes in uremic patients.

The acute effects of both acetate and bicarbonate hemodialysis on erythrocyte transmembrane sodium fluxes were investigated in 15 patients with chronic uremia. We observed a significance (p less than 0.01) stimulation of the Na+,K+ pump in both procedures, with a significant correlation to the amount of fluid removed during hemodialysis (r = 0.56, p less than 0.03). Outward Na+ cotransport fluxes significantly rose (p less than 0.05) after acetate hemodialysis and decreased (p less than 0.05) after bicarbonate hemodialysis. Minor and not significant pre- and posthemodialysis bidirectional changes were observed as regards the intraerythrocyte Na+ and K+ concentration, passive Na+ and K+ permeability, and Na+,Li+ countertransport. Hemodialysis may acutely affect the erythrocyte sodium pump and cotransport fluxes, possibly through the modulation of hormonal factors triggered by the extracellular volume changes.

Acetates↗
PubMed1985

Circulating Fc-receptor blocking factors in IgA nephropathies.

Twenty-one patients with primary IgA nephropathy, 7 patients with Henoch-Schönlein nephritis and 4 patients with IgA nephropathy associated to alcoholic liver cirrhosis were tested for Fc-receptor phagocyte function by measuring the clearance of radiolabelled IgG-sensitized erythrocytes in vivo and the immune phagocytosis by monocytes in vitro. Meanwhile IgG-, IgA-, IgA1-, IgA2-, containing immune complexes, the complement components C3, C4, C3d and the HLA-A, B, DR phenotype were determined. The patients with major urinary abnormalities were well discriminated from those with only minimal hematuria by a defective macrophage function (p less than 0.01) and high levels of IgA immune complexes (p less than 0.02). Since non HLA-A, B, C, DR phenotype was prevalent in patients who had defective Fc-receptor function, whereas a significant correlation was found between Fc-receptor impairment and levels of IgA immune complexes, it appears likely that circulating blocking factors, possibly related to IgA containing immune materials, may impair macrophage function in IgA nephropathies.

Adolescent↗
PubMed1985

Plasma exchange in progressive primary IgA nephropathy.

Five patients with progressive primary IgA nephropathy (PIgAGN) were treated by plasma-exchange (PE) combined with immunosuppressive drugs. Circulating IgA-containing immune complexes (IgAIC), detected by a specific conglutinin solid phase assay, were monitored. Two patients with acute nephritic syndrome and rapidly progressing course, crescent formations and high levels of IgAIC had substantial lasting clinical improvement after several PE, with a fall in IgAIC levels. Another rapidly progressive case with marked sclerotic changes and a longer history of nephritic syndrome, but with normal levels of IgAIC, did not show any clinical improvement after PE. Two patients with a PIgAGN diagnosed several years before and presenting slowly evolutive course had no substantial clinical benefit from PE treatment. IgAIC levels, very high before PE temporarily decreased, but returned to the previous values after the end of the treatment. We conclude that PE combined with immunosuppressive treatment may be of clinical benefit for cases with acute nephritic syndrome of recent onset who still have high levels of IgAIC, even when important crescent formations are present.

Adolescent↗