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Biomedical subjects

G Saglio

Publications and source records attributed to G Saglio.

At least 217 records · Page 12Linked to original sources
PubMed1986

3' c-myc rearrangement in a human leukemic T-cell line.

The human leukemic T-cell line Hut 78, derived from a patient suffering from Sézary syndrome and expressing a mature postthymic membrane phenotype, shows a c-myc rearrangement beginning within 500 base pairs immediately 3' to the c-myc exon 3. Chromosome analysis of the Hut 78 reveals the presence of a hyperdiploid karyotype with a large number of markers and rearrangements, though trisomy is the only cytogenetic anomaly involving chromosome 8. Moreover, as the abnormal c-myc appears to be duplicated, a duplication of the chromosome 8 carrying the abnormal c-myc probably occurred. Unlike four other human leukemic T-cell lines tested, the Hut 78 cells express a high amount of c-myc transcript, suggesting that the 3' c-myc anomaly may cause a deregulation of the expression of this gene.

Base Sequence↗
PubMed1984

Initiation codon mutation as a cause of alpha thalassemia.

Cloning and sequence analysis of the alpha-globin genes from a Sardinian patient with the nondeletion type of hemoglobin-H disease revealed a new type of thalassemia lesion. A mutation in the alpha 2-globin gene changes the initiation codon ATG to ACG and abolishes the function of this gene. Globin mRNA output from the affected alpha 2 locus is decreased relative to the alpha 1 locus. The mutation is detectable in genomic DNA by restriction analysis with the enzyme NcoI. Of the seven Sardinian patients with nondeletion alpha thalassemia screened with this enzyme, six had the initiation codon lesion.

Base Sequence↗
PubMed1984

The beta-globin gene in Sardinian delta beta 0-thalassemia carries a C----T nonsense mutation at codon 39.

Sardinian delta beta 0-thalassemia is an inherited syndrome characterized by the inactivity of the beta-globin gene and the persistent activity of the fetal gamma-globin genes, particularly the A gamma-globin gene. Previous mapping studies with restriction enzymes failed to show any abnormality in the non-alpha globin gene cluster. We have now examined the possibility that this syndrome might result from a single rather than two different defects. Restriction enzyme polymorphisms linked to the delta beta 0-thalassemic non-alpha globin fragments were defined providing the basis for cloning the delta beta 0-thalassemic beta-globin gene from the DNA of a heterozygous patient. This gene appears to carry a C----T single mutation causing the appearance of a stop codon at amino acid position 39 of the beta-globin gene. This mutation was previously reported in beta 0-thalassemic patients, in linkage with different haplotypes. We conclude that Sardinian delta beta 0-thalassemia is the result of two separate mutations, the former one (unknown) responsible for persistent expression of gamma-globin genes, the latter for beta 0-thalassemia.

Base Sequence↗
PubMed1984

A molecular study of a family with Greek hereditary persistence of fetal hemoglobin and beta-thalassemia.

A family was studied in which two inherited defects of the non-alpha-globin cluster segregate: Greek hereditary persistence of fetal hemoglobin (HPFH) and beta-thalassemia. Fragments of the non-alpha-globin cluster from two patients were cloned in cosmid and phage lambda vectors, and assigned to either the HPFH or beta-thalassemic chromosome on the basis of the demonstration of a polymorphic BglII site in the HPFH gamma-globin cluster. The thalassemic beta-globin gene carries a mutation at nucleotide 1 of the intervening sequence I, known to cause beta zero-thalassemia; the beta-globin gene from the HPFH chromosome is entirely normal, both in the intron-exon sequence and in 5' flanking regions required for transcription. As the compound HPFH/beta-thalassemia heterozygote synthesizes HbA, these data prove that the HPFH beta-globin gene is functional, although at a decreased rate; its lower activity is likely to be due to a distant mutation. The HPFH A gamma-globin gene shows only two mutations: a T----C substitution in the large intervening sequence (responsible for the BglII polymorphic site) and a C----T substitution 196 nucleotides 5' to the cap site; the 5' flanking sequence is normal up to -1350 nucleotides upstream from the gene. Circumstantial evidence suggests that the mutation at -196 may be responsible for the abnormally high expression of the A gamma-globin gene.

Base Sequence↗
PubMed1983

Fetal haemoglobin synthesis following fetal liver transplantation in man.

Transplantation of haematopoietic tissue from the fetus to the adult is of considerable clinical and theoretical interest. In particular it could help to understand whether the haemoglobin switch is under the influence of environmental factors or inherently programmed in the haemopoietic cell population. In the present study we have monitored haemoglobin synthesis following fetal liver transplantation (FLT) in a patient with acute leukaemia after intensive chemoradiotherapy. 28 days following FLT, the haemoglobin synthesis showed a predominantly fetal haemoglobin pattern, as determined by globin chain synthesis of bone marrow cells and by the peroxidase anti-peroxidase (PAP) method applied to bone marrow sections treated with anti-fetal haemoglobin antibodies. These findings demonstrate that, in man, fetal haemopoietic cells, transplanted into an adult environment, do not immediately switch to the production of adult haemoglobin.

Bone Marrow↗
PubMed1982

Preferential induction of fetal versus embryonic globin chains in human leukemic cell lines.

By use of a newly developed technique combining affinity chromatography of hemoglobin on haptoglobin-Sepharose and IEF of globin chains, we analyzed the globin synthetic pattern of human K562 cells in both the basal state and after addition of several potential inducers. Hemin only was found effective: its addition at 50 microM results in a quantitative increase of globin chain synthesis (from 0.3 to 1% up to 5%) and a qualitative "switch" with a striking increase of alpha and a decrease of epsilon and zeta chains (relative to the prevailing gamma chains). This system, in which hemin induces changes that mimic to some extent the normal embryonic-fetal switch, might therefore provide a cellular model for investigating molecular mechanisms of globin gene regulation. In addition similar results were obtained with a different human myeloid leukemia cell line, the KG1, thus raising the possibility that the expression of embryonic globin genes in malignant cells might not be simply the consequence of abnormal gene expression but rather reflect a possibly physiological differentiation phenomenon.

Animals↗
PubMed1982

Molecular comparison of delta beta-thalassemia and hereditary persistence of fetal hemoglobin DNAs: evidence of a regulatory area?

The hematological phenotypes of several Mediterranean patients with delta beta-thalassemia and hereditary persistence of fetal hemoglobin have been characterized. Although clinical and hematological characteristics are essentially superimposable in all heterozygous delta beta-thalassemics, these patients show typical G gamma/A gamma ratios in their Hb F, ranging from approximately 0.07 in Sardinian to approximately 0.15 in Sicilian and approximately 0.35 in Spanish patients. A gamma Sardinian-(isoleucine-75 leads to threonine) is found in Spanish patients and accounts for all of the A gamma production in heterozygotes, indicating that persistent production of gamma chains occurs cis to the delta beta-thalassemia gene. The molecular heterogeneity of these conditions is demonstrated by restriction enzyme mapping of DNA; Sicilian and Calabrian patients show a deletion starting from the delta-globin intron and extending several kilobases 3' to the beta-globin gene; in Spanish patients the deletion starts approximately 2-3 kilobases 5' to the delta-globin gene and extends well beyond the beta-globin gene. Comparison of these deletions with previously described ones in Negro and in a new Southern Italian case of hereditary persistence of fetal hemoglobin suggests that the deletion of a region centered at a cluster of repetitive sequences approximately 3.5 kilobases 5' to the delta-globin gene may be critical for the persistent expression of high levels of gamma-globin in hereditary persistence of fetal hemoglobin compared to delta beta-thalassemia. The concept that the deletion or mutation of specific areas (rather than nonspecific changes brought about by large deletions in the globin cluster) is important in determining the persistent expression of gamma-globin genes is supported by the finding of a nondeletion type of delta beta-thalassemia in Sardinians.

Chromosome Deletion↗
PubMed1982

G gamma and a gamma globin chain synthesis in bone marrow and peripheral blood of beta-thalassaemia homozygotes.

G gamma, A gamma and beta globin chain synthesis has been investigated in the peripheral blood and bone marrow from eight beta-thalassaemia homozygotes. In five out of eight cases total gamma chain synthesis was higher in the peripheral blood than in the bone marrow; in seven out of eight cases A gamma chain synthesis was markedly higher in the marrow than in the peripheral blood. These data suggest that ineffective erythropoiesis selects F-cells synthesizing the largest amounts of G gamma chains, while A gamma producing cells are preferentially destroyed in the marrow.

Adolescent↗
PubMed1982

Chemotherapy of advanced non-Hodgkin lymphomas: a report of 35 cases.

Thirty-five patients with stage III and IV non-Hodgkin lymphomas, classified according to Lennert have been treated by combination chemotherapy (CVP). Total remission (complete plus partial) was obtained in 68.5% of the cases and complete remission in 28.5%; 73% of the favorable types and 55% of the unfavorable histologic types achieved tumor response: the difference was not statistically significant, perhaps because of the limited number of cases. Median survival was 14 months for the unfavorable histologic types and 28 months for the favorable types; longer survivals were obtained in patients who achieved complete remission. CHOP regimen after CVP in patients refractory to this type of treatment was not satisfactory in our patients.

Antineoplastic Agents↗
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

Analysis of the gamma chains in a homozygote for HPFH Negro type and in three related heterozygotes.

The gamma-chain structure of a homozygote for HPFH Negro type, previously described by Acquaye and co-workers, and of 3 heterozygotes of the same family has been evaluated. G gamma and A gamma chains were present in a ratio of fetal type (7/3) in the homozygote and in ratios of 2/3 and 1/1 in the heterozygotes, in agreement with data of the literature. T gamma chains were absent in all the cases. Our results, compared with those previously reported for Negro and Greek HPFH, suggest that the T gamma gene is never linked with the HPFH determinant.

Amino Acids↗