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Biomedical subjects

H Wajcman

Publications and source records attributed to H Wajcman.

At least 181 records · Page 10Linked to original sources
PubMed1977

Hemoglobin Djelfa beta98 (FG 5) Val leads to Ala: isolation and functional properties of the heme saturated form.

Hemoglobin Djelfa beta98 (FG 5) Val leads to Ala is a neutrally substituted unstable hemoglobin, exhibiting the same gross features as hemoglobin Köln beta98 (FG 5) Val leads to Met. In addition to the presence of a deheminized fraction, a heme saturated abnormal hemoglobin was visualized and isolated by high resolution electrofocusing. By functional studies of the fully heminized form, a slightly increased oxygen affinity, an impairment of heme-heme interaction and a decreased response to organic phosphates were demonstrated. These functional perturbations point out the importance of the beta98 invariant valyl residue, in the quaternary contacts. They can account for the poor oxygen delivery of erythrocytes.

Alanine↗
PubMed1977

Automatic measurement of the oxygen affinity of Cancer magister hemocyanin.

1. The P50 of Cancer Magister hemocyanin in hemolymph was 40.0 mm at 25 degrees C, nmax = 3.9; at 14 degrees C, 15.0 mm and 3.4; and at 10 degrees C. 10.2 mm and 3.3. 2. In the absence of Ca2+ and Mg2+, the P50 at 25 degrees C was in the range of 150 to 250 mm, depending upon pH. 3. Our results show that temperature variation and pH variation may be important factors in the physiological regulation of oxygen delivery in this species. 4. The automatic recording device of Imai et al. (1970) previously used for the study of hemoglobins, was found to be eminently suitable for the study of O2 affinities of hemocyanins.

Animals↗
PubMed1977

[A new case of hemoglobin J Capetown alpha 92 (FG 4) Arg replaced by gln].

Hemoglobin J Capetown was found incidentally in a patient of french origin suffering from urticaria with delayed pressure oedema. Using a preparative finger-print technique, the structural determination was easy. A functional study of the purified component confirmed the high oxygen affinity of hemoglobin J Capetown and demonstrated a low reactivity for organic phosphates. These results may explain the perturbations observed in the whole blood.

Amino Acids↗
PubMed1976

Isoelectrofocusing: a method of multiple applications for hemoglobin studies.

A microanalytical screening of hemoglobins by isoelectric focusing on acryl-amide gel columns is described. Addition of this technique to our regular analytical procedures revealed many mutants, praticularly some neutral ones which were not resolved by other conventional procedures. Extension of this technique to a quantitative scale permitted rapid isolation of some unstable mutants in an almost pure form ready for functional studies. The natural color of the separated components is often indicative of their nature and in cases like the sulfhemoglobin, Hbs M, they are of diagnostic value. The heme-losing, abnormal, unstable mutants, on the addition of external cyanhemin, take them up and change their isoelectric pH. This is an attractive visible procedure for their diagnosis. From all these results, it appears that isoelectric focusing as a single method brings more information than the other conventional procedures and hence can be considered as a semi-routine investigation for hemoglobin studies before deciding on a much longer procedure.

Fetal Hemoglobin↗
PubMed1976

Congenital enzymopenic methaemoglobinaemia. Clinical and biochemical study of a family with three homozygotes.

Three brothers with congenital recessive methaemoglobinaemia without mental retardation were found to be homozygous for NADH diaphorase deficiency. Twelve family members were heterozygous. One of the probands had marked digital clubbing, an unusual feature in this disease. In the probands, the red-cell NADH diaphorase was very low and unstable, whereas in the leucocytes this enzyme was present at a normal level. Isoelectric focusing of haemoglobin in the three probands showed that the alpha-chain was preferentially oxidized spontaneously. This confirms the greater oxidizability of this chain, as already described on isolated chains.

Adolescent↗
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↗