Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0039730 (thalassemia)
 10,305 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The heterogeneity of residue 136 of the gamma-chain of human hemoglobin has been determined for a patient afflicted with severe alpha-thalassemia. Separation of the cord blood sample into the various constituent hemoglobins A, F, FI and Bart's were done on a column packed with DEAE Sephadex. The amount of glycine or alanine at position 136 was determined for hemoglobins F, FI and Bart's. The ratios determined for all three hemoglobins indicated that the G gamma/A gamma ratio is the same for all three fractions and is similar to that observed in normal cord blood samples.
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PMID:Heterogeneity of fetal hemoglobin in severe alpha-thalassemia. 48 8

Clinical and haematological findings of 164 Turkish beta-thalassaemic heterozygotes with increased Hb-A2 are presented. The series comprised of 19 children, 81 females and 64 males. The majority of these thalassaemic individuals were asymptomatic and only 4 of them had slight or moderate splenomegaly. The mean values of haemoglobin concentration, PCV, MCH and MCHC were significantly lower than those of the corresponding normal controls. Erythrocytosis was present in 33% of them. Hb-A2 values ranged between 3.8 and 6.1%, and between 3.8 and 6.5% as assessed by the methods of DEAE- or DE-cellulose chromatography, respectively. Hb-F was found to be above the normal range in 15.1%. It is established that beta-thalassaemia with increased Hb-A2 is the most frequent variety of thalassaemia in Turkey (80%) and both beta+- and beta0-thalassaemia genes were present in this country. The regional distribution of beta-thalassaemia in Turkey is also presented and the origin of beta-thalassaemia genes in Turkish people is discussed.
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PMID:beta-Thalassaemia with increased haemoglobin A2 in Turkey. A study of 164 thalassaemic heterozygotes. 48 27

Microcolumn chromatography and a new test tube method for quantitation of hemoglobin A2 were compared with column chromatography on DEAE-Sephadex, starch block and cellulose acetate electrophoresis to ascertain their relative accuracy, precision, reproducibility and speed. One hundred seventy-four blood specimens, including 90 samples from genetically proven beta-thalassemia heterozygotes were examined. The mean Hb A2 values in normal and beta-thalassemia heterozygotes were: 2.3% and 4.7%, respectively, determined by microcolumn chromatography; 2.3% and 4.9%, respectively, determined by a new test tube method; 2.5 and 4.6%, respectively, determined by column chromatography on DEAE-Sephadex; 2.6% and 4.8%, respectively, determined by starch block electrophoresis; and 2.4% and 4.8%, respectively, determined by cellulose acetate electrophoresis. Although all five methods were found to be reliable and reproducible, the microcolumn chromatographic method and the newly developed test tube method using DE-52 cellulose are the most rapid, reproducible, economical, and well suited for large scale surveys. By microcolumn chromatography, 7,953 school children and 2,710 other cases were screened for the quantity of Hb A2. In these samples, 578 beta-thalassemia heterozygotes were detected.
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PMID:An evaluation of the methods for quantitation of hemoglobin A2: results from a survey of 10,663 cases. 60 18

Iron binding in the sera of 35 patients with beta thalassaemia major and intermedia was studied. In patients receiving regular blood transfusions since infancy transferrin was completely saturated and about 2.7--7.1 mumol/l of the serum iron could be removed by dialysis or ultrafiltration in the presence of a chelating agent or by filtration on DEAE-Sephadex-catecholdisulphonic acid columns. In contrast, less than 1.0 mumol/l of transferrin bound iron was removed when subjected to the same procedures. The non-specific iron of thalassaemic sera could no longer be demonstrated after incubation with normal serum. These findings indicate that non-specific iron is a chelatable with normal serum. These findings indicate that non-specific iron is a chelatable compound which is readily available for transferrin binding. In view of the known toxicity of unbound iron, its identification in thalassaemic sera might be of relevance to the pathogenesis of tissue damage and the protective effect of iron chelating therapy in this disease.
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PMID:Non-specific serum iron in thalassaemia: an abnormal serum iron fraction of potential toxicity. 70 45

The ethnic and demographic characteristics of the Nice region are predisposing factors in the locally increased frequency of Thalassemia. The use of electronic blood-cell counters has enabled us to pick out easily all those patients presenting with microcytosis. In these patients, foetal hemoglobin, electrophoresis on cellulose acetate and level of hemaglobin A2 by the technique of miniature chromatography on DEAE-cellulose have been analyzed. 270 heterozygotes thalassemics were found in 900 examinations. The statistical study shows an incidence 2% of beta-thalassemia in the Nice region.
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PMID:[Frequency of thalassemia in the South-East of France]. 101 16

Nontransferrin-bound iron (NTBI) was separated from transferrin bound iron (TBI) by DEAE-Sephadex-CDS filtration. TBI is eluted with Tris-NaCl buffer, NTBI that is retained on the column is eluted with citric acid. NTBI was identified in serum from thalassemia and sickle cell patients. Normal serum contained less than 6% NTBI as compared with 15-18% in patient's sera. NTBI levels were decreased significantly after 8 hr chelation with deferoxamine (DFO).
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PMID:Nontransferrin-bound serum iron in thalassemia and sickle cell patients. 379 14

In contrast to findings in the thalasemia syndromes, studies of globin synthesis in subjects with structurally abnormal hemoglobins have generally revealed equal production of alpha and beta polypeptide chains. However, in the present investigation of globin biosynthesis in vitro in blood and marrow from two subjects heterozygous for unstable hemoglobin Leiden, beta6 or 7 Glu --> O, a significant excess of alpha-chain production was revealed. A mother and daughter of northern European ancestry with mild compensated hemolytic anemia were found to have 25% hemoglobin Leiden. Increased hemolysis occurred after the ingestion of a sulfonamide and during infections. Normal levels of hemoglobin A2, 3.0 and 2.7%, and hemoglobin F, 0.8 and 0.6%, were found in the two subjects. Similar percentages of the minor hemoglobins were demonstrated in other family members without hemoglobin Leiden. After incubation of peripheral blood with [(3)H]-leucine, the beta(A)/beta(Leiden) synthesis ratio was 1.3, and the specific activity of beta(Leiden) was 1.3-2 times beta(A). These results indicate preferential destruction of the unstable hemoglobin Leiden. However, in contrast to previous studies of other unstable hemoglobins, there was excess synthesis of alpha-chains. The total beta/alpha synthesis ratio was 0.47-0.63 in peripheral blood and 0.82 in marrow. A pool of free alpha-chains was demonstrated by starch gel electrophoresis and DEAE column chromatography. The synthesis of globin chains was balanced in family members without hemoglobin Leiden. This degree of predominance of alpha-chain synthesis in subjects with hemoglobin Leiden resembles the findings in heterozygous beta-thalassemia. However, the relatively normal hemoglobin content of the cells with this abnormal hemoglobin suggests the possibility of an absolute excess alpha-chain production in the hemoglobin Leiden syndrome.
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PMID:Imbalance in alpha and beta globin synthesis associated with a hemoglobinopathy. 443 Jul 24

We have investigated the use of a high-performance liquid chromatographic (HPLC) column packed with a unique weak cation exchanger prepared by coating silica with poly(aspartic acid) for hemoglobin analysis. The complete separation of hemoglobin Bart's F, A0, A2, S, C, D, E, G, SG, Winnipeg and Sealy was achieved by gradient elution within 30 min. The high resolution made it possible to distinguish hemoglobin variants such as Bart's, AC, AD, AE, AG, AS, ASG, CC, SC, SS, Winnipeg, Sealy and beta-chain variants with thalassemia such as S/beta +, S/beta 0 and S(C)-beta + thalassemia. Comparison of DEAE-cellulose column chromatography and our HPLC method for the quantitation of hemoglobin A2 yielded a good correlation. Hemoglobins A2, C and E are completely resolved on PolyCAT A columns in contrast to both cellulose acetate electrophoresis and DEAE-cellulose column chromatography. The high resolution of the system and the accuracy of the method combined with complete automation make this procedure useful for diagnosis of hemoglobin disorders in both a research and clinical laboratory environment.
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PMID:High-performance liquid chromatography of human hemoglobins on a new cation exchanger. 663 Mar 48

Two alpha-chain variants, Hb G-Philadelphia and Hb Matsue-Oki, were present in members of a relatively large black family from South Carolina. The four Hb G-Philadelphia heterozygotes averaged 35.6% Hb G, suggesting the presence of an alpha-thalassemia-2 condition in cis to the Hb G mutation, which was confirmed by DNA structural analysis. The seven Hb Matsue-Oki heterozygotes averaged 22.2% Hb MO and likely have four active alpha-chain genes. One infant was a compound heterozygote for the two Hb variants which could not be separated from each other. The quantity of Hb G plus Hb MO was 58% by DEAE-cellulose chromatography and 69% by chain analyses. These results and the family data indicate that this child had three active alpha-chain genes, of which one regulated the synthesis of the normal alpha chain, one was mutated to give the alpha G chain, and one to give the alpha MO chain. The amino acid substitutions in Hb G-Philadelphia and Hb Matsue-Oki are located in the tryptic peptide alpha T-9, which is 29 amino acid residues long. Structural analyses of these abnormalities made use of high-pressure liquid chromatography for the separation of both tryptic and thermolytic peptides and of a highly sensitive ultra-micro sequencing procedure. Although the alpha 68 Asn replaced by Lys substitution is readily demonstrable in Hb G-Philadelphia the elucidation of the alpha 75 Asp replaced by Asn replacement in Hb Matsue-Oki was greatly facilitated by the use of these microprocedures.
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PMID:Identification of hemoglobin G-Philadelphia (alpha 68 Asn replaced by Lys) and hemoglobin Matsue-Oki (alpha 75 Asp replaced by Asn) in a black infant. 681 90

Even if different methods were employed in Hb A2 level detection, so far the borderline values between normal and pathological "range" depend on the different laboratories and techniques. The Authors report here an investigation carried out on Hb A2 levels using two different methods: the chromatographic technique by DEAE cellulose column, and the cellulose acetate electrophoresis. The investigation regards 46 normal and 50 beta-thalassemia obligate carrier samples. The results demonstrate that chromatographic technique provides a lowest misclassification rate with a greater reliability. Therefore the use of the microchromatographic procedure for beta-thalassemia screening is recommended.
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PMID:[HbA2 evaluation: comparison between microchromatography on a DEAE cellulose column and conventional cellulose acetate electrophoresis]. 730 17


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