Papers by Giancarlo Falezza
Arteriosclerosis, thrombosis, and vascular biology, 2005
The Italian journal of gastroenterology
Osteocalcin, a recently identified protein, is produced by osteoblasts in the bone tissue. Its pl... more Osteocalcin, a recently identified protein, is produced by osteoblasts in the bone tissue. Its plasma level is a good marker of bone metabolism and is reduced in the presence of 'osteodystrophia', commonly found in cholostatic liver diseases. We assayed plasma osteocalcin levels in 20 cirrhotic patients and compared the values with those of 22 healthy controls. In the same patients we also measured the liver function, clotting and mineral metabolism indexes and calcitonin plasma levels. Osteocalcin levels were significantly lower in liver disease patients than in controls (5.53 ng/ml S.D. 2.57 vs 7.79 ng/ml S.D. 2.23; p less than 0.01) and calcitonin plasma levels were much higher in cirrhotics (130.18 pg/ml S.D. 212.30 vs 28.9 pg/ml S.D. 13.09; p less than 0.05). We think that the low osteocalcin levels observed in cirrhotics may be a consequence of "hepatic osteodystrophy" due to low vitamin D and calcium plasma levels.
Scandinavian Journal of Haematology, 2009
Stroma from normal, AET-treated and PNH red cells and their KCI-extracts (partially purified on S... more Stroma from normal, AET-treated and PNH red cells and their KCI-extracts (partially purified on Sephadex G-200) are able to trigger the activation of the alternative complement pathway. This fact has been demonstrated by: 1the lysis of PNH cells incubateld in serum treated with stroma from normal or PNH-RBC or with their extracts; the addition of Mg2+ or Ca2+ or of their chelators (EDTA, EGTA) to the extract-treated serum enhances or abolishes the lysis 2the reduction of complement activity in fresh serum incubated for 60' with PNHextract 3the appearance of C3 breakdown products in serum incubated with PNH-extract, demonstrated by crossed immunoelectrophoresis. In contrast, the same stroma (or extract) inhibits the sucrose lysis test, in which the lysis takes place through the classical complement pathway. N o differences on the complement activation were observed between PNH and normal RBC stroma and between their chromatographic extracts. These findings may suggest the possible role of diurnal variation of Mgz+ and Ca2+ concentration in precipitating haemolytic attacks and the possibility that small amount of circulating red cell stroma might maintain the haemolysis of PNH RBC.
Scandinavian Journal of Haematology, 2009
The red blood cell (RBC) content of Na' and K+ were measured both on fresh cells from normal, het... more The red blood cell (RBC) content of Na' and K+ were measured both on fresh cells from normal, heterozygous P-thalassaemic and iron-deficiency-anaemic subjects, and on the same cells incubated for 24 h, at 37O C, either in presence or in absence of Calcium (Caz+). Caz+ did not increase membrane permeability to Na+, but increased the K loss, both from normal cells and to a greater degree much more from hypochromic cells. Glucose largely prevented the K' loss from hypochromic cells incubated either in absence or in presence of Caz+, probably maintaining an adequate level of ATP during the incubation. EDTA only partially decreased the permeability to K' in hypochromic cells incubated for 24 h at 37O C, possibly removing CaZ+ bound to the cell membrane. The results suggest that Caz+ does not represent the primary cause of K leak in hypochromic cells, but it is able to enhance a pre-existing peculiar abnormality of the cell membrane when the ATP level slows down.
Clinica Chimica Acta, 1977
The phosphorylation state of the proteins in hereditary spherocytosis erythrocyte membranes, incu... more The phosphorylation state of the proteins in hereditary spherocytosis erythrocyte membranes, incubated in the presence of [-Y-~~P]ATP, appears to be different from that in normal ones. This is indicated by the finding that in the two types of erythrocyte membranes the ratios between the 32P-labeling of their phosphorylserine and phosphorylthreonine residues were different.
British Journal of Haematology, 1973
ABSTRACT
British Journal of Haematology, 1974
ABSTRACT
Acta Haematologica, 2009
The uptake of choline was studied in different types of paroxysmal nocturnal hemoglobinuria (PNH)... more The uptake of choline was studied in different types of paroxysmal nocturnal hemoglobinuria (PNH)-like RBC obtained from normal human erythrocytes by the action of different sulfhydryl compounds. The results were compared with the uptake of choline in true PNH cells and in normal reticulocytes. The PNH-like cells which better mimicked true PNH were those prepared using acetylcysteine. Indeed these erythrocytes displayed a capacity to incorporate choline against a concentration gradient exactly as PNH cells exposed to either acetylcholine or choline. The uptake of choline by by the other PNH-like cells differed from that of PNH erythrocytes in several ways. The results suggest that every sulfhydryl compound induces a different damage on RBC membrane.
Minerva medica, Jan 8, 1982
Clinical history and morbid anatomy findings of a new case of ataxia-telangiectasia are reported.... more Clinical history and morbid anatomy findings of a new case of ataxia-telangiectasia are reported. A 26 years old man, with overt signs of the disease since the age of 8, died for decompensated cirrhosis; in the last year he suffered for cerebral haemorrhage; post-mortem examination showed venous angiectasias in cerebral white matter that caused two macroscopical areas of haemorrhagic infarction and multiple pin-pointed haemorrhages. We suggest that longer survival of patients with A.T., due to better management of infectious complications, permits the appearance of vascular abnormality not only in skin and mucosae, but also in deep organs, generally protected from environmental damages.
Clinica Chimica Acta, 1979
The protein kinase activity located in the cytosol of hereditary spherocytosis erythrocytes is du... more The protein kinase activity located in the cytosol of hereditary spherocytosis erythrocytes is due to multiple forms which can be resolved by Sepharose 6B filtration at high ionic strength into two fractions phosphorylating the whole casein on different sites. The membr~e-bound protein kinases, solubili~ed by 0.7 M NaCf, display an elution volume from Sepharose column and a phosphorylation behaviour towards casein quite similar to those of the more retarded fraction of hemolysate , When compared with the multiple protein kinase forms from normal human erythrocytes, no significant difference has been found.
Acta Haematologica, 2009
2-Mercaptopropionylglycine (2-MPG) transformed normal red blood cells (RBCs) into paroxysmal noct... more 2-Mercaptopropionylglycine (2-MPG) transformed normal red blood cells (RBCs) into paroxysmal nocturnal haemoglobinuria (PNH)-like RBCs in vitro, depending on the concentration, pH and time of incubation. The incorporation of radioactive choline in the presence of acetylcholine was reduced, as in RBCs treated with aminoethylisothiouronium salt (AET). In contrast, the uptake in the presence of choline differed when the RBCs were incubated with the two compounds, being reduced in AET-treated RBCs and increased in 2-MPG-treated ones. As true PNH RBCs incorporated to a higher extent the radioactivity in the presence of both acetylcholine and choline, 2-MPG-treated RBCs seemed to resemble the PNH RBCs better than the AET-treated ones. Present results suggest the possibility of modifying selectively the activity of acetylcholinesterase and the transport of choline through the cell membrane.
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Papers by Giancarlo Falezza