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G R Honig

Publications and source records attributed to G R Honig.

At least 55 records · Page 3Linked to original sources
PubMed1979

Structural bases of the inhibitory effects of hemoglobin F and hemoglobin A2 on the polymerization of hemoglobin S.

We have previously found that the inhibitory effect of hemoglobin F (Hb F) on the polymerization of Hb S proceeds via the formation of asymmetrical hybrid tetramers of the type alpha2betasgamma. Examination of the gelling properties of binary mixtures of Hb S and several Hb variants now shows that, among the gamma chain amino acid residues that differ from those of the beta chain, residues gamma80 (EF4) and gamma87 (F3) are at least partly responsible for this inhibition. Furthermore, we find that mixing Hb A2(alpha2delta2) with Hb S strongly inhibits gelling to an extent similar to that seen with Hb S/Hb F mixtures; this inhibition is attributable to amino acid differences between the delta and beta chain sequences at positions delta22 (B4) and delta87 (F3). Therefore, residues 22, 80, and 87 of the beta chain appear to be involved in intermolecular contact sites that stabilize the deoxy Hb S polymers.

Amino Acid Sequence↗
PubMed1979

Sickle cell syndromes. III. Silent-carrier alpha-thalassemia in combination with hemoglobin S and hemoglobin C.

Silent carrier alpha-thalassemia was identified in two individuals, one with sickle-cell trait and the other hemoglobin (Hb) C trait. Both are parents of a child with characteristic hematologic features of the Hb SC-alpha thalassemia syndrome, including microcytosis and an unbalanced pattern of globin synthesis. In contrast to the typical findings that accompany heterozygous Hb S or Hb C with concomitant alpha-thalassemia trait, neither of the parents had microcytosis nor a percent of the abnormal hemoglobin in their erythrocytes that was below the normal range. In both, however, globin synthesis of peripheral blood reticulocytes was unbalanced, consistent with mild alpha-thalassemia. These findings suggest that the alpha-thalassemia silent carrier may be hematologically indistinguishable from the nonthalassemic individual, even when hemoglobin S or C are present.

Anemia, Sickle Cell↗
PubMed1979

Sickle cell anemia in two White American children: essential laboratory criteria for diagnosis.

A number of hematologic disorders share diagnostic and clinical features of sickle cell anemia but have significantly different genetic implications and prognosis. Because of these differences, the establishment of a precise diagnosis is essential for the child in whom any form of sickle cell disease is identified. To illustrate the requirements for a definitive laboratory diagnosis of sickle cell anemia, this report presents the approach to establishing this diagnosis in two white American patients. From a review of the literature, these patients appear to be the only white Americans with sickle cell anemia in whom the diagnosis has been unequivocally established.

Anemia, Sickle Cell↗
PubMed1978

beta-Thalassemia arising as a new mutation in an American child.

A 6-year-old child of northern European ancestry was found to have microcytic, hypochromic anemia with an elevated level of hemoglobin A2 and an unbalanced pattern of globin chain synthesis characteristic of beta-thalassemia trait. Hematologic and globin synthesis studies of both parents yielded entirely normal results. Identification of the mother and father as the biological parents was established with a high order of reliability by determination of erythrocyte, serum, and HLA genetic markers. These findings suggest that the picture of beta-thalassemia observed in this child represents a new mutation.

Child↗
PubMed1978

Unbalanced globin chain synthesis by Hb Lincoln Park (anti-Lepore) reticulocytes.

Hemoglobin synthesis was studied in vitro in reticulocytes from a patient with the anti-Lepore variant Hb Lincoln Park. Incorporation of L-leucine-3H into the alpha and beta delta chains of Hb Lincoln Park was substantially less than the incorporation into the corresponding globin chains of Hb A, with the rate of synthesis of the beta delta chain being similar to that of the delta chain of Hb A2. Synthesis of the alpha and total non-alpha globin components was unbalanced, with a substantial excess of alpha chain synthesis. These findings help to explain the mild hemolytic disease present in individuals with this hemoglobin variant.

Globins↗
PubMed1978

Sickle cell syndromes. II. The sickle cell anemia-alpha-thalassemia syndrome.

Five American black patients, ages 1 to 16 years, with the sickle cell anemia-alpha-thalassemia syndrome are described. Each patient had persistent microcytosis not explained by iron deficiency, and in each family the presence of alpha-thalassemia in combination with sickle cell trait was demonstrated in one of the parents. In one patient, in whom the diagnosis of sickle cell anemia was established at birth, an elevated level of Barts (gamma4) hemoglobin was also found. In these patients levels of alkali-resistant hemoglobin and reticulocyte counts were similar to those of sickle cell anemia patients of comparable age; however, stained smears of their peripheral blood rarely showed the presence of irreversibly sickled cells. No major ameliorative effect of the alpha-thalassemia on the clinical expression of the sickle cell disease of these patients was evident.

Adolescent↗
PubMed1978

Hemoglobin Lincoln Park: a betadelta fusion (anti-Lepore) variant with an amino acid deletion in the delta chain-derived segment.

An electrophoretically slow-moving hemoglobin variant was identified in three members of a family originating from Southern Mexico. The variant, Hb Lincoln Park, made up approximately 14% of the total hemoglobin and appeared to have normal stability and functional properties. None of the individuals in whom the abnormal hemoglobin was present was anemic, but each had a mildly elevated reticulocyte count. Structural data suggest that the non-alpha chain of Hb Lincoln Park represents a betadelta gene-fusion product, with normal beta chain structure of the amino-terminal portion of the chain and delta sequences subsequently, the crossover point occurring between animo acid residues 22 and 50. An additional abnormality is the deletion of valine-137, a component of the delta gene-derived segment of the betadelta chain. To account for the development of this abnormal globin chain, a series of intergenic crossovers is proposed; the first, a nonhomologous crossover between the beta and delta genes, presumably gave rise to the betadelta fusion gene; two additional crossovers, one of them unequal, may then have occurred between the same beta and delta genes to produce the amino acid deletion.

Adult↗
PubMed1976

Sickle cell syndromes. I. Hemoglobin SC-alpha-thalassemia.

Hematologic and globin synthesis studies were performed in a black American family in which the genes for alpha-thalassemia and hemoglobins (Hb) S and C were segregating. The following distribution of these abnormalities was found: father, sickle cell trait + alpha-thalassemia; mother, HbC trait + alpha-thalassemia, propositus, HbSC + alpha-thalassemia; older sibling, alpha-thalassemia trait; and younger sibling, hemoglobin H disease. The child with HbSC-alpha-thalassemia demonstrated more severe anemia and a more hemolytic picture than is typical of HbSC disease. Her erythrocytes exhibited decreased osmotic fragility in comparison with HbSC erythrocytes, but had an indistinguishable oxygen equilibrium curve and 2, 3-diphosphoglycerate (2, 3-DPG) level. Erythrocyte sickling in the patient, however, was significantly reduced, with less than 35% sickle forms observed at nearly complete oxygen desaturation. The sibling with hemoglobin H disease exhibited 26% Bart's (gamma4) hemoglobin at birth, a level comparable with that seen in infants with HbH disease in Far Eastern populations. At age 5 months typical findings of mild hemoglobin H disease appeared, with HbH making up 6.5% of the total hemoglobin.

Anemia, Sickle Cell↗
PubMed1976

Sickling syndromes in children.

The sickle cell syndromes comprise a highly diverse group of disorders which have in common the presence of sickle hemoglobin in the blood erythrocytes. The establishment of a precise diagnoffort involving both the patient and his family, but because of the important differences in prognosis and management of these various syndromes, an accurate diagnosis is of fundamental importance. Definitive therapy has not yet been developed for any of these disorders, but with the application of available forms of treatment these patients can be benefited substantially.

Adolescent↗
PubMed1975

Hemoglobin J-Chicago (beta76(E20) Ala yields Asp): a new hemoglobin variant resulting from substitution of an external residue.

An electrophoretically fast-moving hemoglobin variant was found in a 2-yr-old boy who was referred for evaluation with findings of iron deficiency anemia. The anemia was corrected, and no hematologic abnormality remained after treatment with iron. Oxygen affinity of the blood was normal, and no evidence was found of instability of the variant hemoglobin. Structural studies demonstrated a substitution of aspartic acid for alanine at beta76 (E20). This change did not appear to cause any functional disruption of the hemoglobin in this patient, as would be predicted by the position of the affected animo acid residue on the surface of the molecule.

1-Propanol↗
PubMed1974

Sites of acetylation of sickle cell hemoglobin by aspirin.

Aspirin acetylates a variety of sites on both the alpha and beta chains of hemoglobin S. Nevertheless, the vast majority of acetyl groups become attached to three loci: betaLys 59, betaLys 144, and alphaLys 90. These observations reveal some molecular details of this transacylation reaction and suggest interesting possibilities for its extension to other acylsalicylates with a variety of different structures.

Aspirin↗