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Biomedical subjects

B Ringelhann

Publications and source records attributed to B Ringelhann.

At least 37 records · Page 2Linked to original sources
PubMed1977

Homozygotes for the hereditary persistence of fetal hemoglobin: the ratio of G gamma to A gamma chains and biosynthetic studies.

Two sons of a previously reported Ghanaian homozygote for the hereditary persistence of fetal hemoglobin (HPFH) (Ringelhann et al., 1970) also are HPFH homozygotes. In addition, another unrelated adult Ghanaian homozygote has been detected. All of these Ghanaian homozygotes as well as three American Black HPFH homozygotes have the G gamma A gamma type of HPFH with a G gamma to A gamma ratio of about 3:2, in contrast to an Asiatic Indian homozygote who has the G gamma type. Globin chain synthesis in HPFH homozygotes is unbalanced, with a gamma/alpha ratio of 0.6 or less, whereas it is balanced in heterozygotes according to most reports.

Child↗
PubMed1977

Hemoglobin alpha chain deficiency in black children with variable quantities of hemoglobin Bart's at birth.

Hematologic and globin chain synthesis studies have been made in 21 children, aged 2 to 6 years, many of their parents, and several normal adults and alpha-thalassemia heterozygotes. At birth, 11 children had about 5% hemoglobin (Hb) Bart's, 5 had about 2% Hb Bart's, and 5 had no trace of Hb Bart's. A significant decrease in mean corpuscular volume. (MCV) and mean corpuscular hemoglobin (MCH) values and an increase in the beta/alpha ratio was observed in the first group; microcytosis and hypochromia were absent in the children of the second group although the beta/alpha ratio was significantly increased. The alpha chain deficiency is familial. Increased alpha/alpha ratios were present in many parents although only two parents of children with 5% Hb Bart's at birth had hematologic findings suggestive of the presence of the same type of defect as observed in the children with the larger amount of Hb Bart's at birth.

Adult↗
PubMed1976

A new look at the protection of hemoglobin AS and AC genotypes against plasmodium falciparum infection: a census tract approach.

A total of 4,097 randomly selected children under 5 years in Accra, Ghana were investigated for Hb type, malarial parasite species, and parasite density. Even though malarial infection rates in this metropolitan population were lower as compared to holoendemic areas, the differential survival of Hb S carriers was confirmed. In addition, similar but less pronounced survival effects were seen in Hb C heterozygotes. Hb S carriers had the highest infection rates. More females than males were infected. Individuals with a moderate parasite count (less than 50,000/ml) were seen more commonly amoung AS and AC individuals as compared to AA controls. It is postulated that heterozygotes have a better immunological defense against the deleterious effects of P. falciparum infection because persistent parasitemia stimulates antibody production.

Age Factors↗
PubMed1975

Futher investigations of the gamma-chaina in a ghanaian adult, homozygous for hereditary perisitence of fetal haemoglobin. Isolation of gamma CB-3 peptides and Ggamma:Agamma ratio determination in human Hb E.

The gamma-chain in a Ghanain homozygous for hereditary persistence of fetal haemoglobin was considered to be of the Ggamma type on the basis of the amino acid analysis of gammaTp XIV (gamma133-144) of the Hb F of this subject [1]. Recently, the sequence of residues gamma134-137 of the gamma-chain of this subject was determined and found to contain some alanine at position gamma136. It is therefore of the Ggamma + Agamma type. A rapid technique for the isolation of gammaCB-3 (gamma134-146) peptides in human fetal haemoglobin for Ggamma:Agamma ratio determination is described.

Adult↗
PubMed1975

Hereditary persistence of fetal hemoglobin, beta thalassemia, and the hemoglobin delta-beta locus: further family data and genetic interpretations.

Three Negro kindreds with hereditary persistence of fetal hemoglobin (HPFH) alone and in combination with various other hemoglobin abnormalities including beta thalassemia are presented. Among 11 offspring of two women heterozygous for both HPFH and the delta chain mutation Hb B2, five inherited the HPFH gene and six inherited the Hb B2 gene. In another kindred, a man inferred to be heterozygous for both HPFH and Hb C had six children; three offsprivg obtained the Hb C gene and three the HPFH gene. Similarly, a woman heterozygous for both Hb S and HPFH transmitted the Hb S gene to one of her two children and the HPFH gene to the other. Thus among 19 offspring, no crossovers between the HPFH locus or the Hb delta-beta locus were observed. These and earlier data are compatible with deletion of the Hb beta and delta loci as the primary event to explain the genetic origin of HPFH. Genetic considerations indicate that the finding of a single person with a hematologically normal phenotype among offspring of heterozygotes for both the African type of HPFH and a Hb beta or Hb delta structural abnormality would invalidate the deletion model.

Adolescent↗