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Biomedical subjects

C Natta

Publications and source records attributed to C Natta.

7 recordsLinked to original sources
PubMed1979

Plasma levels of tocopherol in sickle cell anemia subjects.

Plasma tocopherol levels of less than 0.8 microgram/g lipid were considered indicative of a vitamin E-deficient status. Based on this criterion, 10 out of 13 sickle cell anemia patients who were not in crisis, were considered deficient in vitamin E as compared to none of 24 normal control subjects. Sickle cell anemia patients treated with 150 IU vitamin E (dl-alpha-tocopheryl acetate) three times a day for 1 to 2 months had plasma tocopherol levels similar to control subjects. The possible role of vitamin E status on the manifestation of sickle cell anemia is discussed. The present study confirmed the vitamin E-deficient status of subjects with beta-thalassemia. Six of seven patients with beta-thalassemia had tocopherol levels of less than 0.8 mg/g lipid.

Adolescent↗
PubMed1979

Heterogeneity of DNA fragments associated with the sickle-globin gene.

We have examined the genetic polymorphism previously reported to be associated with the sickle-cell (beta s) gene. The polymorphism involves an alteration of the DNA sequence 3' to the beta-globin gene as detected with the restriction endonuclease, Hpa I. In normal individuals, the beta-globin gene is contained within a DNA fragment of 7.6 kilobases (kb), whereas 87% of individuals with sickle-cell anemia have been reported to have the beta s-gene associated with a 13.0-kb Hpa I fragment. We have studied this polymorphism in 31 New York Black individuals homozygous for sickle-cell anemia to ascertain its genetic and biochemical significance and to evaluate its potential use in the prenatal diagnosis of sickle-cell disease. Our results show only a 58% association of the beta s-gene and the 13.0-kb Hpa I fragment, as well as the presence of additional variants involving the Hpa I site. In addition, the 13.0-kb fragment is also found associated with the beta c- and beta A-genes. Thus, the Hpa I polymorphism probably represents a change in DNA not specifically associated with the beta s-gene, and appears to antedate the beta s-and beta c-mutations.

Anemia, Sickle Cell↗
PubMed1978

Failure of the alpha-thalassemia gene to decrease the severity of sickle cell anemia.

A 15-yr-old black male with homozygous sickle cell disease was severely growth retarded and had a chronic hemolytic anemia requiring transfusions. Globin chain synthetic studies of both peripheral blood reticulocytes and bone marrow cells revealed a ratio of alpha to betas globin synthesis (alpha/betas ratio) of 0.5, indicating the presence of an alpha-thalassemia gene. Messenger RNA isolated from the bone marrow of the patient was translated in the wheat germ cell-free system, and the globin synthesized had an alpha/betas ratio of 0.7. The hemolysate prepared from incubated bone marrow cells was fractionated on a Sephadex G100 column. The results showed that there was a peak of radioactivity that eluted after the hemoglobin peak. When this pooled peak was analyzed by CMC chromatography, the alpha/betas ratio was 0.9. These globin intermediates, probably dimers, may have contributed to the hemolysis in this patient.

Adolescent↗
PubMed1976

Quantitation of human gamma globin genes and gamma globin mRNA with purified gamma globin complementary DNA.

Complementary DNA (cDNA) specific for gamma-globin nucleotide sequences has been prepared by hybridizing total cDNA made from cord blood messenger RNA (mRNA) as template to an excess of normal adult human globin mRNA and recovering the single-stranded cDNA from hydroxylapatite. The specificity of the gamma cDNA for gamma mRNA sequences is strongly supported by the hybridization of this cDNA at low Cot values (Co, concentration of RNA and t, time in seconds) to RNA samples containing large amounts of functional gamma globin mRNA and the lack of hybridization to RNA samples containing little, if any, gamma-globin mRNA. The absence of cross-hybridization of gamma cDNA with alpha, beta, and delta mRNAs is demonstrated by the complete hybridization of the gamma cDNA to mRNA samples completely lacking either alpha or beta and delta mRNA. An estimate of the number of gamma-globin genes in human cellular DNA was obtained by hybridization of purified gamma cDNA to DNA from spleen and white blood cells of normal and beta-thalassemia subjects and measurement of the percent of gamma cDNA hybridized at saturation. The results indicate that there are between one and two gamma-globin genes per total haploid gene DNA equivalent obtained from both normal and beta-thalassemia subjects. These values are consistent with genetic evidence for the presence of multiple gamma gene loci in human cells. The finding that the number of gamma-globin genes in beta-thalassemia DNA is similar to that in nonthalassemia DNA indicates that a deletion of gamma-globin genes cannot account for either the inadequate gamma-globin synthesis or indirectly for the decreased or absent beta-globin synthesis in beta-thalassemia cells.

Amino Acid Sequence↗
PubMed1975

Relative numbers of human globin genes assayed with purified alpha and beta complementary human DNA.

Purified alpha and beta globin complementary DNAs (cDNAs) have been separated from total radioactively labeled human globin cDNA using mRNA purified from liver of a hydrops fetalis (alpha thalassemia). The beta cDNA hybridizes to the hydrops fetalis mRNA while the alpha cDNA remains single-stranded. the purified alpha and beta cDNAs were assayed for their purity by their hybridization to mRNA prepared from reticulocytes of nonthalassemia, alpha thalassemia, and beta thalassemia subjects. The results indicate that the separated cDNAs are selective in hybridization to alpha or beta globin mRNAs, respectively. The previously reported deficiency of globin mRNA in thalassemia cells has been confirmed with these purified cDNAs. The purified alpha and beta cDNAs were hybridized to cellular DNA to non-thalassemia, beta+ thalassemia, and hydrops fetalis (alpha thalassemia) DNA. The alpha cDNA hybridized to hydrops fetalis liver DNA to a much lower extent that beta cDNA, confirming the previously reported deletion of alpha globin genes in hydrops fetalis. By contrast, both the alpha and beta DNA probes hybridized to the same extent to spleen DNA from non-thalassemia and from beta+ thalassemia patients. Between two and five globin genes in non-thalassemia and beta+ thalassemia DNA hybridize to beta cDNA and one to five to alpha cDNA. These studies indicate that in beta+ thalassemia, there is no detectable deletion in beta globin genes. The genetic defect in beta+ thalassemia appears to be due to either repression of transcription of beta globin genes or abnormal processing of beta globin mRNA.

Bone Marrow↗