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Biomedical subjects

G Perona

Publications and source records attributed to G Perona.

At least 55 records · Page 3Linked to original sources
PubMed1982

Detection of normal and malignant megakaryocytes by anti beta-thromboglobulin serum. An immunofluorescence study.

An antiserum to beta-thromboglobulin was used in immunofluorescence to detect normal and malignant megakaryocytes. In normal peripheral blood and bone marrow smears, only platelets and megakaryocytes were specifically stained by this antiserum. Among 25 cases of acute lymphoid and non-lymphoid leukaemia, only 2 exhibited a clear positivity in a % of blasts, thus proving their megakaryocytic origin. This method is proposed as a simple and useful tool to detect normal and malignant megakaryocytes on smears.

Adult↗
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

Serum selenium levels in malignant lymphoproliferative diseases.

Serum selenium levels were measured in 38 patients with malignant lymphoproliferative diseases (MLD) and in 34 non-hospitalized healthy individuals. Selenium was determined by proton induced x-ray emission. In Hodgkin's disease and non-Hodgkin malignant lymphoma the mean serum levels of selenium were not different from those of the control group. On the contrary lowered mean serum selenium concentrations were observed in the group with chronic lymphocytic leukaemia (5.2 +/- 0.7 microgram/100 ml) as compared to normal individuals (7.9 +/- 0.3 microgram/100 ml). The difference is highly significant (P less than 0.005). A second selenium test was made in 11 out of the 38 patients within 8 weeks from the beginning of radiotherapy or chemotherapy; unchanged levels were found.

Adolescent↗
PubMed1979

Neonatal erythrocyte glutathione peroxidase deficiency as a consequence of selenium imbalance during pregnancy.

The red blood cell (RBC) glutathione peroxidase (GSH-Px) activity and routine haematological parameters were measured in 38 healthy north Italian full-term pregnant women and in their newborn infants. In 31 pairs the serum selenium concentration was also measured. Data were compared with those of 20 normal adult controls (10 males and 10 females). Newborn infants exhibited significantly lower RBC GSH-Px activity and serum selenium concentrations than adult controls. Pregnant women had serum selenium values intermediate between those of adult female controls and their newborn infants. In both the pregnant women and newborns the RBC GSH-Px activity correlated with the level of selenium in serum which suggests that the neonatal RBC GSH-Px deficiency may be partially due to insufficient availability of selenium during pregancy. Factors other than selenium concentration, e.g. hormonal and genetic, might also affect the RBC GSH-Px activity as suggested by sex differences and mother/child concordances in enzyme activity found in our cases.

Adolescent↗
PubMed1978

In vivo and in vitro variations of human erythrocyte glutathione peroxidase activity as result of cells ageing, selenium availability and peroxide activation.

Cases showing erythrocyte glutathione peroxidase (GSH-Px) defects have been previously described. Our experiments demonstrate that a number of non genetic factors may influence the GSH-Px activity in human erythrocytes. Selenium administration in vivo was followed in four subjects by elevation in erythrocyte GSH-Px activity ranging from 30% to 1400%. Selenium operates mainly in the bone marrow erythroblasts by facilitating the synthesis of active GSH-Px molecules; experiments in vivo demonstrate that, in the youngest erythrocytes, selenium can raise the enzyme activity, but by a different mechanism. The reticulocyte GSH-Px activity appears to depend on selenium availability and may vary over a wide range. In some normal and iron deficient subjects the GSH-Px activity in the youngest erythrocyte fraction was equal or lower than that previously found in whole erythrocytes of patients affected by haemolytic anaemia. During erythrocyte life, GSH-Px activity may either diminish or increase, and these variations are inversely related to the initial GSH-Px activity in youngest cells. In vitro experiments with the addition of acetyl-phynyl-hydrazine strongly suggest that elevation of GSH-Px activity may be due to allosteric enzyme activation by activated oxygen.

Anemia, Hypochromic↗
PubMed1977

Erythrocytic glutathione peroxidase: its relationship to plasma selenium in man.

Erythrocytic glutathione-peroxidase (GSH-Px) activity and plasma selenium concentrations were measured in 14 patients: 7 with iron deficiency and 7 with raised serum iron levels. The decreased enzymatic activity in iron deficiency was confirmed. Plasma selenium was significantly lower in patients with lower serum iron; furthermore there is a significant correlation between serum iron and plasma selenium concentrations. Another correlation even more significant was found between plasma selenium and enzyme activity in all the cases we studied. These data suggests that the importance of iron for GSH-Px activity may be merely due to its relationship with selenium and that plasma selenium concentration may be of critical importance for enzyme activity.

Anemia, Hypochromic↗
PubMed1976

Plasma iron and erythrocytic glutathione peroxidase activity. A possible mechanism for oxidative haemolysis in iron deficiency anemia.

The red cell glutathione-peroxidase (GSH-Px) activity of 9 normal subjects is compared with that of 15 cases of iron deficiency anaemia and with 13 cases of heterozygous beta-thalassemia with the same degree of anaemia and hypochromia. 2 cases of sideroblastic anaemia with high serum iron levels were also examined. Enzymatic activity was found to be significantly decreased in iron deficiency anaemia (about 55% of normal range), while it was not affected in heterozygous beta thalassaemia and it was increased in the 2 cases of sideroblastic anaemia. Moreover, GSH-Px activity exhibited a significant correlation with serum iron levels in all the patients studied. The observed modifications in GSH-Px activity are not correlated with erythrocyte ageing because reticulocyte-poor fractions exhibited GSH-Px activity which was not significantly reduced in respect of the reticulocyte-rich ones. These data seem to suggest that iron has a crucial connection with erythrocyte GSH-Px and that the enzyme deficiency may be of some importance in explaining the decreased red cell survival observed in severe iron-deficiency anaemias.

Anemia, Hypochromic↗