Biomedical subjects

T Meloni

Publications and source records attributed to T Meloni.

At least 91 records · Page 5Linked to original sources

PubMed1980

gamma chain composition in five Italian newborns heterozygous for Hb F Malta G gamma-117 His leads to Arg.

The percentage of Hb F Malta G gamma-177 His replaced by Arg and the gamma chain composition have been evaluated at birth and at different times after birth in five Italian newborns heterozygous for this variant. The percentage of Hb F Malta ranged at birth from 24% to 31% of the total Hb F, while the average G gamma/A gamma chain ratio was about 7/3, overlapping the values observed in normal newborns. T gamma chains were detected in three out of five newborns, with a percentage of about 10% of the total Hb F. After birth the Hb F Malta declined faster than the total Hb F; thus, the Hb F decrease during the first 45 d of life is mainly due to the switch-off of the G gamma locus containing the Hb F Malta gene.

Aging↗

PubMed1980

alpha-Thalassaemia and hyperbilirubinaemia in G-6-PD-deficient newborns.

53 newborn infants with both G-6-PD deficiency (29 male hemizygotes and 24 female heterozygotes) and alpha-thalassaemia, and 120 newborn infants with only the enzymatic defect (60 male hemizygotes and 60 female heterozygotes) were studied. 12 of those with both G-6-PD deficiency and alpha=thalassaemia, and 32 of those with only G-6-PD deficiency showed hyperbilirubinaemia. alpha-Thalassaemia does not seem to be implicated in the development of hyperbilirubinaemia in G-6-PD-deficient newborns.

Female↗

PubMed1980

Coexistence of three hemoglobins with different alpha-chains in two unrelated children (with family studies indicating polymorphism in the number of alpha-globin genes in the Sardinian population).

In each of two families from Sardinia, Italy, we have found segregation for two alpha-chain hemoglobin variants, which we have identified as G Philadelphia [alpha 68 (E17) Asn leads to Lys] and J Sardinia [alpha 50 (CE8) His leads to Asp], respectively. One family also shows segregation for the beta-thalassemia trait. One subject in one family and two subjects in the other family have in their red cells both hemoglobin variants, G and J, in addition to HbA. One of the subjects, a newborn baby, has six major hemoglobin components; alpha 2A beta 2, alpha 2A gamma 2, alpha 2G beta 2, alpha 2G gamma 2, alpha 2J beta 2, alpha 2J gamma 2. These three cases are to be added to three previous cases in the literature in whom three different alpha-chains have been found in the same blood. These findings prove that the alpha-chain locus is duplicated in the Sardinian population, as it is in other populations. The relative amounts of the various hemoglobin species found in members of our two families, through three and four generations respectively, suggest that chromosomes with and without duplication may coexist in the same population.

Blood Protein Electrophoresis↗

PubMed1979

Favism: erythrocyte metabolism during haemolysis and reticulocytosis.

The reduced activity of glucose-6-phosphate dehydrogenase (D-glucose-6-phosphate; NADP+ 1-oxidoreductase; G6PF) in Mediterranean erythrocytes explains the precarious equilibrium of the hexose monophosphate pathway (HMP) and the susceptibility of these cells to haemolytic agents. G6PD-deficient erythrocytes, in steady-state conditions, have a low NADPH/NADP+ ratio, thus allowing the HMP to operate at its maximal intracellular rate and to compensate the intrinsic erythrocyte enzyme deficiency. Studies started soon after accidental intake of fava beans by sensitive G6PD-deficient subjects demonstrate a decrease of both NADPH/NADP+ ratio and reduced glutathione. The metabolic effects induced by fava beans may be attributed to oxidative stress probably associated with an inhibitor effect of some unknown metabolite on the HMP. The availability of erythrocytes from subjects recovering from haemolysis with high reticulocyte counts and increased G6PD activity, provides new information on the rate of synthesis as well as on the in vivo decay of the mutant enzyme. Correlation of G6PD activity to reticulocyte count and extrapolation to an ideally homogenous population of reticulocytes reveal that the mutant enzyme is synthesized at a nearly normal rate. Furthermore, the present correlation allows an estimate of the in vivo half-life of Mediterranean G6PD. The rate of decline of about 8 d observed in this study well correlates to the intracellular metabolic aspects of G6PD Mediterranean erythrocytes.

Adolescent↗

PubMed1979

Serum glutamic oxalacetic transaminase, glutamic pyruvic transaminase, gamma-glutamyl transpeptidase and glutamic dehydrogenase levels in favism.

Serum GOT, GPT, gamma-GT and GLDH were determined in 15 G-6-PD-deficient subjects during a hemolytic crisis and hemoglobinuria due to ingestion of fresh fava beans. The same G-6-PD-deficient subjects were studied again 2 months after the crisis, when they were asymptomatic. 15 normal healthy children served as controls. A statistically significant increase, above normal, in serum GOT, GLDH and gamma-GT was observed in the favic subjects during the crisis. All the values reverted to normal in the asymptomatic period.

Alanine Transaminase↗

PubMed1978

Salicylamide glucuronide formation in newborn babies with G-6-PD deficiency.

Salicylamide glucuronide formation has been studied in 23 newborn babies with erythrocyte G-6-PD deficiency and in 15 normal newborns on the first day of life. Glucuronide formation was significantly lower (p less than 0.001) in the former in comparison with the controls. In the newborns with G-6-PD deficiency who subsequently became hyperbilirubinemic an even lower mean glucuronide formation was observed (p less than 0.01) in respect to the non-jaundiced G-6-PD-deficient newborns.

Glucosephosphate Dehydrogenase Deficiency↗

PubMed1978

Thyrotropin, prolactin and growth hormone response to synthetic thyrotropin-releasing hormone in newborn infants.

The effects of 50 microgram synthetic thyrotropin-releasing hormone (TRH) intravenously on thyrotropin (TSH), prolactin (PRL) and growth hormone (GH) levels were studied in 8 normal male newborns during the first hours of life. Mean plasma GH concentrations were similar to baseline values during the period of study; on the contrary, plasma PRL and TSH values increased in all infants after TRH administration. These data demonstrate a normal pituitary reserve of PRL and TSH in the early period of human life.

Growth Hormone↗

PubMed1978

Agar in control of hyperbilirubinemia of full-term newborn infants with erythrocyte G-6-PD deficiency.

40 full-term newborn infants with erythrocyte glucose-6-phosphate dehydrogenase (G-6-PD) deficiency were used for a study concerning the effectiveness of agar per os in preventing severe hyperbilirubinemia. 20 randomly selected neonates were given agar (1 g/kg/day) orally in 4 daily doses from their 1st to their 5th day of life. 20 infants were not treated and served as controls. Three exchange transfusions were performed in the experimental as well as in the control group. According to these results, agar does not seem to be effective in preventing severe hyperbilirubinemia, which frequently occurs in newborn infants with erythrocyte G-6-PD deficiency.

Administration, Oral↗

PubMed1978

Effect of LRH on gonadotropin secretion in newborn male infants.

The concentrations of LH and FSH were measured in eight male newborn babies, aged 4-6 h, before and after the administration of 25 micrograms synthetic LHR. A comparison was performed with six control newborns receiving normal saline. Both LH and FSH rose significantly in all subjects after LHR administration. Their values were significantly higher than those observed during the control study. These data demonstrate sensitivity of the pituitary gonadotropes to synthetic LHR and a pubertal-type response to LH in the early hours of human life.

Follicle Stimulating Hormone↗

PubMed1978

Dynamic evaluation of prolactin secretion during the early hours of life in human newborns.

PRL secretion was evaluated in 30 human newborns during the early hours of life. Both levodopa and pyridoxine administration failed to suppress PRL release in all subjects. Synthetic TRH elicited a constant, prompt increase in PRL levels. No significant changes were observed after somatostatin injections. These results demonstrate normal pituitary PRL reserve in newborns. The failure to respond to levodopa and pyridoxine administration might reflect partial immaturity of the pituitary dopaminergic receptors.

Humans↗

PubMed1978

Action of somatostatin, levodopa and pyridoxine on growth hormone (GH) secretion in newborn infants.

We studied the effect of i.v. levodopa, pyridoxine and synthetic somatostatin in 28 normal babies during the first hours of life. Somatostatin caused a decrease in GH levels in all infants; in addition, both levodopa and pyridoxine infection paradoxically suppressed GH secretion in all subjects. It is concluded that in the first hours of life GH secretion can be suppressed by synthetic somatostatin as well as by levodopa and pyridoxine administration.

Depression, Chemical↗

PubMed1976

Salicylamide-Glucuronide formation in children with favism and in their parents.

Salicylamide-glucuronide formation has been determined in 27 children who underwent a favism crisis, 25 parents, and in 25 normal children who served as controls. A highly significant mean lower glucuronide formation was observed in the favism group in respect to the controls. The difference between fabic children and their parents was significant, and between parents and controls there was no significant difference.

Child↗

PubMed1975

Haptoglobin, hemopexin, hemoglobin and hematocrit in newborns with erythrocyte glucose-6-phosphate dehydrogenase deficiency.

Hemolysis was studied in 40 G-6-PD-deficient newborn infants, half of whom had bilirubin blood levels within the normal range whereas the others, who were hyperbilirubinemic, underwent exchange transfusion. Hemoglobin, hematocrit, hemopexin and haptoglobin showed no or little differences between either of the two groups and the controls. The findings confirm the authors' assumption expressed elsewhere that this form of hyperbilirubinemia is not hemolytic in nature.

Bilirubin↗

PubMed1974

Phototherapy for neonatal hyperbilirubinemia in mature newborn infants with erythrocyte G-6-PD deficiency.

Phototherapy was employed in treatment of newborn infants with erythrocyte G-6-PD deficiency whose serum bilirubin concentrations exceeded 10 mg/100 ml on the second or third day of life. Exchange transfusions were required for two of the 12 treated babies and for six of the 12 control infants. It is noteworthy that exposure to light did not affect the erythrocyte GSH content nor did it increase hemolysis.

Bilirubin↗

PubMed1974