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Biomedical subjects

C Natta

Publications and source records attributed to C Natta.

At least 19 recordsLinked to original sources
PubMed1988

Low serum levels of carotenoids in sickle cell anemia.

Serum carotenoids, tocopherols and retinol were analyzed in patients with sickle cell anemia (SCA) and in control subjects. The data show the following: the serum levels of the major carotenoids, alpha and beta carotene, cryptoxanthin, lycopene lutein, alpha tocopherol and retinol were significantly lower in SCA patients. These findings reflect an additional abnormality of the antioxidant system in SCA patients. Gamma tocopherol, on the other hand, was significantly elevated, consistent with the previously reported reciprocal relationship between serum alpha and gamma tocopherols. Thus, these data taken together with the earlier findings on the lower levels of plasma alpha tocopherol and ascorbic acid suggest that the entire antioxidant system may be compromised in SCA patients. This may contribute in part to the phenotypic expression of the condition.

Anemia, Sickle Cell↗
PubMed1985

Compartmentalization of iron in sickle cell anemia--an autopsy study.

In autopsy studies of two sickle cell anemia (SCA) patients, iron was totally absent from all organs in one case in which the serum ferritin had been low, while the other patient demonstrated hepatic, splenic, and renal siderosis but no iron stores in the bone marrow. Serum ferritin had been very high in this case. These findings suggest that in SCA bone marrow biopsy may be an unreliable means to determine iron stores, but rather the ferritin level should be used.

Adult↗
PubMed1983

A family study of IgG subclasses in sickle cell anemia.

Three siblings with sickle cell anemia were studied immunologically and hematologically. Their patterns of Protein A-Sepharose chromatography distribution showed considerable heterogeneity, particularly with respect to the IgG2 and IgG3 subclasses, even though their hematological make up was similar. An attempt was made to correlate their IgG2: IgG1 subclass ratios with their clinical history of recurrent bacterial infections, as well as a possible compensatory IgG3 heterogeneity.

Adult↗
PubMed1981

Glutathione peroxidase activity in whole blood of patients with sickle cell anaemia.

Whole blood glutathione peroxidase was found significantly increased relative to controls in a group of 21 black patients with sickle cell anaemia. One control group consisted of 15 normal black subjects. A second control group, consisting of 21 black patients with various abnormal haemoglobins including alpha-thalassaemia, also showed a tendency to enhanced glutathione peroxidase activity, confirming previous reports that elevated glutathione peroxidase levels are secondary to a variety of haemolytic conditions, rather than typical of sickle cell anaemia.

Anemia, Sickle Cell↗
PubMed1980

Preferential binding of beta C relative to beta S globin to stroma in hemoglobin SC disease.

Globin synthesis was measured in blood samples of four patients with hemoglobin SC Disease. In the stroma-free supernatant, globin synthesis was balanced with alpha/(beta S + beta C) = 1. In the exhaustively washed stroma, there was a preferential binding of beta chains to stroma, similar to that reported for Sickle Cell Anemia. However, while the beta S/beta C ratio was balanced in the supernatant (0.8-0.9), the beta S/beta C ratio of the stroma varied from 0.2 to 0.4. Therefore, beta C is bound to stroma in preference to beta S in hemoglobin SC disease. These findings are consistent with the concept that binding of globin to stroma is related to the electrophoretic charge of the hemoglobin.

Anemia, Sickle Cell↗
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↗
PubMed1974

Preferential binding of beta s globin chains associated with stroma in sickle cell disorders.

Sickle cell anemia (SS) is associated with abnormalities of the red cell membrane and decreased red cell deformability. The present study assesses globin chain binding to stroma in SS, sickle cell trait (AS), and nonsickling (AA) cells. The results indicate that there is preferential binding of newly synthesized beta(S) globin to red cell stroma in SS cells and preferential binding of beta(S) to stroma compared to beta(A) in AS cells. These studies show that beta(S) globin binding to stroma accompanies the membrane abnormalities in SS and AS patients.

Anemia, Sickle Cell↗