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Biomedical subjects

J B Wilson

Publications and source records attributed to J B Wilson.

At least 253 records · Page 14Linked to original sources
PubMed1981

Quantitation of three types of gamma chain of HbF by high pressure liquid chromatography; application of this method to the HbF of patients with sickle cell anemia or the S-HPFH condition.

A modification of a high pressure liquid chromatographic (HPLC) procedure is described that enables the complete separation and quantitation of the A gamma T, A gamma I, and G gamma chains in human fetal hemoglobin. The method, which is fast and accurate, requires 5 to 2000 micrograms Hb F. The purity of the Hb F is not essential and admixture of up to 70% adult Hb does not interfere with the determination. The method has been applied to the Hb F of 64 Black SS patients and 7 persons with the Hb S-HPFH (G gamma A gamma type) conditions. (A) Both "adult" G gamma to A gamma (2:3) and "newborn" G gamma to A gamma (3:2) ratios were observed in adult SS patients, 8 yr and older. Only 12% of the SS patients had the "newborn" ratio. This high G gamma to A gamma ratio may be due to a modification of the genetic switch mechanism that regulates the change of this ratio after birth. (B) Intermediate G gamma to A gamma ratios were only found in young SS patients, 5 yr of age or less. The results suggest a delayed switch of the newborn leads to adult ratio in sickle cell anemia. (C) The A gamma T chain was present in only 6% of all SS patients. One patient is homozygous for this variant chain. (D) Three of the 7 subjects with Hb S-HPFH were positive for the A gamma T chain. Its percentage was low, which suggests that the A gamma T chain gene is in trans of the HPFH determinant. (E) Quantitation of the three gamma chain types is also possible in the Hb F from Hb S heterozygotes with (nearly) normal Hb F levels. Such an analysis is useful for an evaluation of genetic conditions involving variations in the production of (different types of) Hb F.

Adolescent↗
PubMed1980

Carboxymethyl-cellulose microchromatography for the quantitation of hemoglobin Bart's (gamma 4) and its use in the detection of the alpha-thalassemia conditions.

A modification of an existing (micro) CM-cellulose chromatographic procedure is introduced for the quantitation of hemoglobin Bart's (or gamma 4) in blood samples of newborn babies. Normal newborn with four active alpha chain genes (alpha alpha/alpha alpha) have small amounts (average 0.55%) of this abnormal hemoglobin while increased percentages are present in newborn with an alpha-thalassemia-2 heterozygosity (alpha 0 alpha/alpha alpha; average 1.55%) or an alpha-thalassemia-2 homozygosity (alpha 0 alpha/alpha 0 alpha; average 4.65%). The identification of hemoglobin Bart's in normal newborn was made by high-performance liquid chromatography, and the absence of contaminating non-hemoglobin proteins was confirmed by electrophoresis and additional chromatographic experiments. This rapid procedure is useful for the detection and differentiation at time of birth of the different alpha chain deficiencies which are common among various populations in the world.

Chromatography↗
PubMed1980

Hemoglobinopathies observed in the population of the Southeastern United States (SE-USA).

A survey of nearly 250,000 citizens of Georgia and South Carolina conducted during the past twenty years has led to the detection of over 40 abnormal hemoglobins and several additional hemoglobinopathies. The presence of some of these hemoglobin abnormalities cause (severe) clinical symptoms but others remain undetected unless a specific search is initiated. The incidence of Hb S varies slightly among the populations of different areas, and appears to be the highest in the coastal counties of Georgia and South Carolina. A survey of over 17,000 persons of mainly high school and college age has shown that a significant number of cases with clinically significant hemoglobinopathies will remain undetected unless such surveys are actively promoted.

Adolescent↗
PubMed1980

Adult and fetal hemoglobin production in erythroid colonies from subjects with beta-thalassemia or with hereditary persistance of fetal hemoglobin (HPFH).

The synthesis of alpha and non-alpha chains (beta, delta, G gamma, and A gamma) was studied in cultures of peripheral blood mononuclear cells from eleven beta-thalassemia heterozygotes, two HPFH heterozygotes, and one HPFH homozygote. The synthesis of Hb F in the thalassemia colonies (average value: 12.6%) was comparable to that in normal adult colonies (average value: 12.6%) was comparable to that in normal adult colonies (average value: 12.2%). The percent G gamma chain in the Hb F varied greatly but a relationship between the G gamma chain percentage in the Hb F from colonies and that from peripheral blood was established. The relative synthesis of Hb A2 in colonies of beta-thalassemia heterozygotes (average value: 5.8%) was 1.6 times as much as that in colonies of normal adults (average value: 3.6%). Hb A2 and Hb A were absent in the colonies of the HPFH homozygote. The alpha/non-alpha (i.e., beta, gamma, and delta) ratio of the hemoglobins in the cultured cells of the beta-thalassemia heterozygotes and the alpha/beta and alpha/beta ratios of isolated Hb A and Hb A2 were about one (range 0.74 to 1.38). The alpha/gamma ratio of the Hb F synthesized in BFUe-derived colonies of the HPFH homozygote, however, was 1.5. These results suggest a deficiency in the in vitro culture system resulting in decreased levels of alpha-mRNA or in a partial inhibition of initiation of protein synthesis which is known to reduce the synthesis of alpha chains more than that of the beta chains.

Adult↗
PubMed1980

The determination of the percentages of G gamma and A gamma chains in human fetal hemoglobin by HPLC.

A newly developed HPLC procedure (1) was used to study the percentages of G gamma and A gamma chains in the Hb F from newborn and patients with sickle cell anemia. The method gives data comparable to those obtained with a more laborious chemical procedure. However, the presence of the A gamma T chain, i.e., the A gamma chain with an Ile replaced by Thr substitution at position 75, interferes with the determination of the G gamma to A gamma ratio because the A gamma T and G gamma chains have the same chromatographic mobility.

Anemia, Sickle Cell↗
PubMed1980

Angina audit.

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Aged↗
PubMed1979

Separation of tryptic peptides of normal and abnormal alpha, beta, gamma, and delta hemoglobin chains by high-performance liquid chromatography.

High-performance liquid chromatography (HPLC) was used to separate tryptic peptides of the normal alpha, beta, gamma, and delta chains of human hemoglobins A, F, and A2 and of the abnormal chains of 25 hemoglobin variants. In addition, the separation of chymotryptic peptides of the oxidized core of the normal alpha chain by HPLC was evaluated. HPLC has several advantages over conventional methods used for the separation of proteolytic fragments of hemoglobin chains. The method is fast, and reproducible, and requires only small quantities of material. Several peptides are eluted as single zones, thus eliminating the need of rechromatography for further purification. Characteristic changes in the elution pattern of the peptides often indicate specific modifications.

Chromatography, High Pressure Liquid↗
PubMed1979

The chemical heterogeneity of human hemoglobin F. Direct evidence for the existence of three types of gamma chain, the G gamma I, A gamma I, and A gamma T chains.

Direct evidence is presented for the existence of three types of gamma chain of human hemoglobin F. A modification of a CM-cellulose chromatographic method has allowed the incomplete separation of these gamma chains while high pressure liquid chromatography and fingerprint analyses of tryptic peptides of zones of the isolated gamma chains, and amino acid analyses of isolated peptides were used to identify the chains. These studies have shown that the presence of a glycyl residue in position 136 (G gamma chain) is directly related to that of an isoleucyl residue in position 75 (I gamma chain), thus indicating the existence of an G gamma I chain, and that the presence of an alanyl residue in position 136 (A gamma chain) can be related to that of an isoleucyl residue in position 75, thus suggesting the existence of an A gamma I chain. When the isoleucyl residue at positive 75 is replaced by a threonyl residue, invariably it is related to the alanyl substitution at position 136 (A gamma T chain). These data support indirect evidence from case analyses and family studies which were published before, and indicate that the T gamma chain is an allele of the A gamma which should be renamed the A gamma T chain.

Adult↗
PubMed1979

Epilepsy.

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Asphyxia↗