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Biomedical subjects

L Vettore

Publications and source records attributed to L Vettore.

At least 37 records · Page 2Linked to original sources
PubMed1983

Micro-chromatographic measurement of hemoglobin A1 in uremia.

In an investigation of the reliability of the measurement of HbA1 by microcolumn chromatography for monitoring glucose metabolism in chronic renal failure, measurements were made in 96 uremic patients. Thirty-one patients were undialyzed, 42 patients including 10 with primary diabetes mellitus were on hemodialysis, and 23 patients were on continuous ambulatory peritoneal dialysis (6 with primary diabetes mellitus). Significantly raised HbA1 values were observed in all groups, whether their glucose tolerance was normal or decreased. Azotemia was not statistically correlated either with HbA1 values, or with glucose tolerance. Dialyzed primary diabetic patients showed HbA1 levels which were significantly higher than those in non-diabetics, but some overlap was evident. The results suggest that the increased values of HbA1 in uremic patients depend on the plasma concentration of either glucose which leads to the formation of glycosylated Hb or of urea which leads to the formation of carbamylated Hb. These are indistinguishable by microcolumn chromatography. Therefore this method cannot be recommended for evaluation of glucose metabolism in uremic patients.

Adolescent↗
PubMed1982

Erythrocyte cation content, globin chain synthesis and glucose metabolism in dysmyelopoietic syndromes.

Red blood cells (RBC) from 13 patients suffering from dysmyelopoietic syndromes (DMPS) have been studied. About half of these subjects showed an abnormal Na+ and K+ leakage of their RBC, which were incubated at 37 degrees C for 24 h. The mean rate of the glycolytic pathway increased significantly and the glycolysis values correlated well with the Na+ gain. Moreover, 9 out of the 13 patients showed an abnormal biosynthetic ratio of haemoglobin chains in their reticulocytes. Since the multiple defects in DMPS erythrocytes do not seem clearly linked by cause-effect relationships, they probably derive from several cooperating factors in pathological erythroid precursors, leading to RBC membrane damage.

Aged↗
PubMed1980

A new density gradient system for the separation of human red blood cells.

A new density system for the separation of human red blood cells by density-gradient centrifugation is described. The gradient medium is made with colloidal silica particles coated with polyvinylpyrrolidone suspended in aqueous solution of meglamine diatrizoate. By this method, more than 10 red-cell fractions can be separated. These show different ages (by creatine content and 59Fe in vivo labelling) and different characteristics (ie, potassium content). A 40-fold enrichment in reticulocytes can be obtained in the top layers, with a great improvement of specific activity in labelling procedures of newly synthesized globin chains. The method is simple, rapid, inexpensive, reliable, nontoxic for erythrocytes, and is suitable for globin synthesis and other studies of erythrocyte metabolism.

Cell Separation↗
PubMed1979

Evaluation of the scintigraphic technique for detecting bone metastases in 100 breast cancer patients.

In an attempt to evaluate the utility of bone scintigraphy for the diagnosis and follow-up of skeletal metastases, radioisotopic scan (total body) by 99mTc has been performed on 100 patients suffering from breast cancer in various stages. The radiographic control followed the scan on the basis of clinical or scintigraphic suspicion of bone lesions. Twenty-one patients showed metastases by scan, and in all but 2 the radiography was concordantly positive; in 22 subjects scintigraphy and radiology demonstrated non-malignant lesions. Both scan and radiology were used to explore 169 metastatic localizations, with concordant results in 45% of the sites; however, 7% of the sites with discordant results became positive for metastasis by radiology some months after the scan positivity. The false-negative results were more frequent in the radiographic study (27%) than with the scintigraphic scan (21%). The latter technique was unable to detect osteoblastic lesions in particular. The scintigraphic test also gave reliable results in the follow-up procedure, frequently anticipating the radiological modifications of metastatic lesions. In conclusion, bone scan often appears to be more accurate and preocious than the roentgengraphic test in the detection and the follow-up of skeletal metastatic lesions; it suggests the utility of the bone scan as a preliminary test, which allows a more rational use of the radiology.

Bone Neoplasms↗
PubMed1978

The diagnostic value of serum copper levels and other hematochemical parameters in malignancies.

An increase in the serum copper (Cu++) level has been described as a sensitive index of disease activity in several hematologic and nonhematologic malignancies. In order to explore the diagnostic value of Cu++ compared to other hematochemical parameters frequently abnormal in malignancies, Cu++, serum alpha2 globulin (alpha2), plasmatic fibrinogen (Fibr), the erythrocyte sedimentation rate (ESR), and serum iron (Fe++) have been detected and evaluated in 267 patients affected with the following diseases: Hodgkin's lymphoma (HL), non-Hodgkin's Lymphomas (NHL), Acute Leukemias (AL), Chronic Myeloid Leukemia (CML), Chronic Lymphocytic Leukemia (CLL), Myeloma (MM), and Breast Cancer (BC). The best correlation between Cu++ increase and disease activity has been found in HL, NHL, AL, and BC. In these diseases, when the considered parameters were compared, Cu++ and ESR showed a similar pattern, i.e., a high frequency of abnormalities in active disease. It is concluded that Cu++ represents a good complement to some other aspecific parameters in evaluating the activity and diffusion of neoplasias and the therapeutic results, particularly in HL, NHL, AL and BC.

Alpha-Globulins↗
PubMed1978

Standardization of a simple method for the estimation of haemoglobin A2.

An improved method for the estimation of haemoglobin A2, at the same time precise, simple and cheap, is proposed. Haemoglobin A is separated from haemoglobin A2 by electrophoresis on Cellogel in discontinuous buffer at alkaline pH. The strips of cellulose acetate containing the haemoglobin fractions are completely dissolved in 80% acetic acid. The percentage of haemoglobin A2 present in each sample is calculated from the values for the spectrophotometric absorbance at 396 nm. The average percentage of haemoglobin A2 (+/- standard deviation) determined by this method was 2.31 +/- 0.37 in 51 normal subjects, and 4.64 +/- 0.53 in 29 subjects with heterozygous beta-thalassaemia.

Electrophoresis, Cellulose Acetate↗
PubMed1977

The canine erythroid cell system: a new model for study of regulatory mechanism in hemoglobin synthesis.

The total methodology for a new mammalian erythroid cell system which permits direct investigation of the terminal stages of hemoglobin synthesis and assembly is described. The canine system allows quantitative separation of native heme containing alpha and beta chains which recombine to for tetrameric hemoglobin with normal functional properties (n = 2.17). These chains can be utilized for investigation in a cell-free system in which the rates of synthesis of alpha and beta chains are equal (alpha/beta = 0.96 +/- 0.05). Methodology for the quantitative separation of globin allows study of the effects of balanced and unbalanced globin chain synthesis in both the intact cells and the cell-free system.

Animals↗
PubMed1977

Increased potassium permeability induced in vitro by menadione in normal human red cells.

Normal red blood cells, preincubated for 75 min with 1.15 mM menadione sodium bisulfite lose potassium and water on subsequent incubation at 37 degrees C for 24 h without menadione. The potassium loss is increased by addition of calcium and prevented by addition of glucose. Since normal red cells treated with menadione behave like untreated hypochromic cells, both from beta-thalassaemia or iron deficiency anaemia in respect to membrane permeability to potassium, it may be supposed that menadione induces in normal red cells an abnormality similar to that naturally occurring in hypochromic cells.

Calcium↗
PubMed1977

Increased potassium permeability by calcium in hypochromic red blood cells.

The red blood cell (RBC) content of Na+ and K+ were measured both on fresh cells from normal, heterozygous beta-thalassaemic and iron-deficiency-anaemic subjects, and on the same cells incubated for 24 h, at 37 degrees C, either in presence or in absence of Calcium (Ca2+). Ca2+ 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 Ca2+, 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 37 degrees C, possibly removing Ca2+ bound to the cell membrane. The results suggest that Ca2+ 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.

Anemia, Hypochromic↗
PubMed1977

Permeability of membrane to potassium in hypochromic red cells with different specific density.

In hypochromic anaemias (heterozygous beta-thalassaemia and iron deficiency anaemia) ligher red cells lose more K+ than heavier ones, following incubation at 37 degrees C for 24 h. Both in the light and heavy fractions two subpopulations of cells with different permeability to K+ can be separated by a new centrifugation after incubation. On the basis of the results, a relationship between K+ permeability and probability of survival in hypochromic cells is suggested.

Anemia, Hypochromic↗
PubMed1977

Effects of dipyridamole on sodium and potassium content of human red blood cells.

The effects of dipyridamole on potassium and sodium content of human red blood cells from normals or from patients with hypochromic anaemia, and of normal red cells pretreated with menadione, have been studied. Dipyridamole added to the incubation medium decreases the loss of potassium and the accumulation of sodium in all three types of red cells incubated at 37 degrees C for 24 h, either with or without calcium. The possible mechanism underlying these effects of dipyridamole is discussed.

Anemia, Hypochromic↗