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D Labie

Publications and source records attributed to D Labie.

At least 109 records · Page 6Linked to original sources
PubMed1976

A case of hemoglobin M Boston. New data about valency hybrids brought by isoelectrofocusing study.

In Hemoglobins M, as the result of a mutation theheme iron of the abnormal chain is atabilized in an oxidized form unable to carry oxygen. In this paper, we discuss the case of hemoglobin M Boston characterizing this abnormal hemoglobin as valency hybrid by spectral studies and utilising this mutant as a marker, in isoelectricfocusing, we bring the arguments that the two intermediary bands of oxidation correspond to alpha2+beta2+2 and alpha2+2beta2+3 We also indicate that the abnormal spectrum of Hb M interferes with the estimation of methemoglobin, giving erroneous values. We have shown that isoelectric focusing and subsequent scanning give a definite idea about the amount of abnormal chain present.

Densitometry↗
PubMed1975

Isolation and functional characterization of hemoglobin Casper: beta106(G8) Leu replaced by Pro.

Hemoglobin Casper (beta106Leu replaced by Pro) can be separated from hemoglobin (Hb) A by isoelectric focusing on polyacrylamide gel. This abnormal hemoglobin was estimated to be 30% of teh total by both isoelectric focusing and heat lability kinetics. Its oxygen equilibrium curves indicate a high oxygen affinity, low degree of subunit interaction, and a decreased Bohr effect. Mixtures of Hb Casper and Hb A appear to bind oxygen as if no hybrid molecules exist.

Diphosphoglyceric Acids↗
PubMed1975

Hemoglobin Cochin-Port-Royal: consequences of the replacement of the beta chain C-terminal by an arginine.

Hemoglobin Cochin Port-Royal beta 146 (HC3) His yields Arg is the second example in which the beta C-terminal residue is replaced. Owing to the known importance of His beta 146 in the co-operative effects of hemoglobin, the functional properties of this variant were carefully studied. It had a normal Hill coefficient but a reduced alkaline Bohr effect. However, the reduction in Bohr effect is less than the halving predicted from previous mutants and modified hemoglobins.

Amino Acid Sequence↗
PubMed1975

Abnormal hemoglobin synthesis in some leukemic patients.

Hemoglobin chain synthesis during leukemic processes has been studied on patients having fetal hemoglobin. All cases showed the following abnormalities : (1) a relatively increased synthesis of the beta chain ; (2) an important increase of the free dimeric precursors pool, with, most of the time, a predominance of alpha chain. If the first point suggests an alpha-thalassemia feature, the presence of free alpha chains shows evidence for a more complex mechanism not only due to a decrease of messenger RNA. The hypothesis of a clonal disorder could neither be demonstrated nor ruled out. The observed abnormalities could be due to a defect in a alpha chain depending regulation mechanism.

Carbon Radioisotopes↗
PubMed1975

A new case of haemoglobin Bucuresti in a Cuban family: further functional studies.

A new case of haemoglobin Bucuresti beta 42 (CD1) Phe yields Leu is described in a Cuban family. The functional studies confirm the results already described--a low oxygen affinity and a decreased haem-haem interaction. In addition to this, the reactivity for 2, 3 diphosphoglycerate (2, 3 DPG) was shown to be normal. The instability is mostly due to a fast rate of haemichromes formation.

Adult↗
PubMed1975

[Molecular evolution].

The molecular evolution is considered in several protein families. It can be studied with the data of an entirely known structure, like in hemoglobin or cytochrome, or of only partial structural data, as for proteases or immunoglobulins. In the case of isozymes the study of physico-chemical and kinetic properties is more indirect. Finally, it is shown that the molecular mechanisms are always the same, happening probably at the same frequency, the differences being due to a variable selection by molecular constraints and adaptation to the environment.

Biological Evolution↗
PubMedDate not supplied

Homozygous cases for hemoglobin J Mexico (alpha54 (E3)Gln replaced by Glu) evidence for a duplicated alpha gene with unequal expression.

Hemoglobin J Mexico has been found in five generations of a large Algerian family. Nine subjects have 55% Hb J although their parents, siblings and offspring may have 31%, the usual quantity found in heterozygotes. Those with 55% Hb J are considered to be homozygous for a chromosome carrying both a normal alpha chain locus and a locus for alphaJ. The proportion of the abnormal hemoglobin in all the subjects is in favor of an unequal expression of both loci, the amount of protein synthesis directed by the alpha J gene being greater than that directed by the alpha A. In two heterozygotes a slightly higher proportion of the Hb J (38%) suggests the presence of a single normal alpha chain locus in trans. An associated alpha-thalassemia was excluded by biosynthetic studies in this family.

Genes↗