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Biomedical subjects

J B Wilson

Publications and source records attributed to J B Wilson.

At least 271 records · Page 15Linked to original sources
PubMed1979

The synthesis of fetal hemoglobin types in red blood cells and in BFU-E derived colonies from peripheral blood of patients with sickle cell anemia, beta+ - and delta beta-thalassemia, various forms of hereditary persistence of fetal hemoglobin, normal adults and newborn.

The biosynthesis of two types of human fetal hemoglobin (Hb F), namely Hb F with G gamma chains having glycine in position 136 and Hb F with A gamma chains having alanine in position 136, was studied in blood samples and in cultures of erythroid precursors from blood of patients with different hemoglobinopathies. High pressure liquid chromatography (HPLC) was adapted to allow the separation of the methionyl-containing tryptic peptides G gamma T-15 and A gamma T-15 (which include the Gly leads to Ala polymorphism at position 136) from a digest of microquantitites of 35S-methionyl labelled Hb F. This method was sensitive enough to quantitate the relative production of the G ygamma and A gamma chains by erythroid colonies derived from cloned Burst Forming Units (bfu-e) which were cultured for 16 days on methylcellulose. The production of Hb F in these colonies was generally higher than the level of Hb F in blood except for subjects with the G gamma A gamma-HPFH heterozygosity. The G gamma to A gamma ratio in the Nb F produced in cultures of cells from G gamma delta beta-thalassemia or G gamma-HPFH heterozygotes was lower and that from A gamma-HPFH heterosygotes was higher than the ratios in the Hb F of the corresponding peripheral blood cells. Mixtures of G gamma and A gamma chains were present in cell cultures of SS patients, beta+-thalassemia homozygotes and G gamma A gamma-HPFH heterozygotes in a ratio similar to that in the Hb F of mature red cells. These data suggest that erythroblasts in BFU-E derived colonies reactivate all available gamma chain structural genes, both in cis and in trans to the abnormal determinant. Hb F biosynthesis by adult blood samples concerns primarily the G gamma chains. This was particularly striking for blood samples in which erythroblasts were absent and the biosynthesis took place in fetal reticulocytes. Thus, the F-retuculocytes in blood of A gamma-HPFH heterozygotes with about 5% Hb F of the A gamma type produced primarily Hb F with G gamma chains. Similar differences were observed for G gamma A gamma-HPFH heterozygotes and, less strinkingly, for SS patients. A satisfactory explanation for this observation has not yet been obtained.

Adult↗
PubMed1979

Hemoglobin Riyadh-beta 0-thalassemia in an Indian family.

An Indian (Asian) patient with compound heterozygosity for Hb Riyadh and beta 0-thalassemia is described. Hb Riyadh forms about 95% of the hemoglobin present. The clinico-pathological picture is identical to that of simple beta-thalassemia trait confirming the harmless nature of the substitution beta 120(GH3) Lys leads to Asn.

Adult↗
PubMed1979

The structure of goat hemoglobins. V. A fourth beta chain variant (beta-D-Malta; 69 Asp is replaced by Gly) with decreased oxygen affinity and occurring at a high frequency in Malta.

During a survey of hemoglobin types in goats in the Republic of Malta a variant (Goat Hb D-Malta) was discovered which differs from normal goat Hb A by the substitution of an aspartyl residue in position beta 69 (E13) by a glycyl residue. The gene frequency of the beta D allele was 0.255; 29 homozygous Hb D goats were present among 327 animals sampled. Homozygous Hb D goats also produce Hb C, whose beta chains are the product of a non-allelic beta C structural gene. Goat Hb D-Malta has a distinctly decreased affinity for molecular oxygen.

Amino Acid Sequence↗
PubMed1979

Hb P-Nilotic in association with beta0-thalassemia: cis-mutation of a hemoglobin betaA chain regulatory determinant?

Hb P-Nilotic which is produced by a hybrid of beta and delta genes was found in several members of a Sudanese family, three of whom had an associated beta-thalassemia. Chemical analyses confirmed the crossover between positions 22 and 50 of the beta delta P chain. The Hb p-Nilotic heterozygote had completely normal hematology, but the patients with the Hb P-Nilotic--beta-thalassemia condition had moderately severe clinical and hematological abnormalities which were considerably more pronounced than those in the father who had a beta-thalassemia heterozygosity. The absolute cellular contents of normal and abnormal non-alpha chains in these subjects and the results of in vitro chain synthesis analyses suggested that the thalassemia gene in this family is of the beta0 type and that the beta A gene which is present in cis to the beta delta P gene is incapable of being stimulated when the beta0-thalassemia determinant is present in trans. It is proposed that a number of recombination events produced a beta delta P hydrid gene with duplication of the beta A gene in cis as well as a change in an untranscribed strand of DNA which controls the expression of the beta A gene.

Bone Marrow↗
PubMed1978

ATP, trehalose, glucose and ammonium ion localization in the two cell types of Dictyostelium discoideum.

Ultra-microfluorometric techniques were adapted to follow several compounds related to energy metabolism through the developmental cycle of Dictyostelium discoideum. Each compound (ATP, trehalose, glucose, and ammonium ion) was found to be present in stalk and/or spore cells. The accumulation of NH4+ was interpreted as an indication of protein degradation, a source of energy in this organism. During the early stages of differentiation NH4+ was localized only in prestalk cells. However, it accumulated in spore cells during culmination such that levels were comparable in the two cell types by the end of development. Trehalose, an energy source for germinating spores, was found in both cell types but was preferentially degraded in stalk cells late in development. Glucose, the degradation product of trehalose, was localized in prestalk cells and varied inversely with trehalose levels. ATP was not localized in a specific cell type during development. However, ATP declined in stalk cells at an earlier stage of development.

Adenosine Triphosphate↗
PubMed1978

Hb Nottingham (alpha2beta2 (FG5) 98 val leads to gly) in a Caucasian male: clinical and biosynthetic studies.

A second instance of the unstable mutant Hb Nottingham (alpha2beta2 (FG5) 98 Val leads to Gly) is reported in a 7-year-old boy. Because of splenomegaly, cholelithiasis, and frequent episodes of abdominal pain, he underwent a splenectomy and cholecystectomy at age 6. The surgery resulted in both an amelioration of his RBC destruction and an acceleration of his rate of growth.

Child↗
PubMed1978

Hemoglobin Hofu or alpha 2 beta 2 [126 (H4) Va1 leads to Glu] found in combination with hemoglobin S.

Hb Hofu, alpha 2 beta 2 [126 (H4) Va1 leads to Glu], was found in 10 members of 2 apparently unrelated Valmiki families in central India. None showed evidence of hemolysis and hemoglobin levels were normal in most. In two individuals, Hb Hofu occurred in combination with Hg S, but neither had clinical manifestations of sickle cell disease. In samples containing Hb Hofu, the isopropanol precipitation test was positive. Quantitation of the hemoglobin fractions by DEAE-cellulose chromatography showed that Hb Hofu constituted a mean of 23--25% of the total whether in combination with Hb A or Hb S.

Female↗
PubMed1978

Variability in the interaction of beta-thalassemia with the alpha-chain variants Hb G-Philadelphia and Hb Rampa.

Two unrelated families are reported in which beta-thalassemia trait occurred with a heterozygosity of Hb G-Philadelphia (alpha2 68(E17)Asn leads to Lys beta2) in one family and with Hb Rampa (alpha2 95(G2)Pro leads to Ser beta2) in the other. The percentage of Hb G-Philadelphia was not influenced by the simultaneous presence of a beta-thalassemai determinant, but that of Hb Rampa was descreased from 20% in the simple heterozygote to about 6% in persons with the Hb Rampa-beta-thalassemia combination. Data from in vitro recombination experiments with isolated alpha X, alpha A, and beta A chains, with heme attached, indicated a preferential formation of Hb A over Hb Rampa but not over Hb G-Philadelphia in conditions of relative beta-chain deficiency. This suggests that the rate of assembly of monomers to form dimers or tetramers can be an important mechanism of controlling the quantity of certain hemoglobin variants with critical substitutions in heterozygotes.

Adolescent↗
PubMed1977

Biosynthetic and structural studies of hemoglobin in a patient with congenital dyserythropoietic anemia type I.

A 25 year old woman with congenital dyserythropoietic anemia (CDA) Type I is described. Typical morphologic abnormalities of the erythroid precursors in the bone marrow by light and electron microscopy, marked ineffective erythropoiesis and iron loading were present, Globin chain synthetic ratios as well as functional and structural studies on the patients hemoglobin were normal, ruling out the presence of thalassemia or a mutant hemoglobin which can both give rise to morphologic and clinical features similar to CDA. The laboratory findings on this patient and family members and a brief review of the literature are presented.

Adult↗