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Biomedical subjects

J Lecomte

Publications and source records attributed to J Lecomte.

At least 253 records · Page 14Linked to original sources
PubMed1976

Isolation of anti-haemagglutinin antibodies with an influenza A virus immunoadsorbent.

The X-31 strain of influenza A (H3N2) virus has been covalently bound to CNBr activated agarose for the separation of anti-haemagglutinin antibodies. The virus immunoadsorbent was used repeatedly under high ionic strength alkali buffer and acid conditions without altering appreciably its antibody binding capacity. Sequential elution of bound anti-haemagglutinin antibodies with increasing concentrations of sodium iodide has enabled the physical separation of antibody populations with low and high avidity for the virus immunoadsorbent. In haemagglutination inhibition (h1) assays, the less avid population reacted only with the homologous X-31 virus, wheras the more avid antibody population reacted both with the homologous and the related cross-reactive A/England/42/72 (H3N2) strains. Sequential elution under acid conditions did not completely remove the bound anti-haemagglutinin antibodies and those eluted retained little of their anti-haemagglutinin activity. From a practical point of view, given a specific antiserum, it is feasible to use whole virus as an immunoadsorbent for the purpose of isolating populations of antibodies of different avidities and cross-reactivities. Furthermore, sodium iodide as an eluting agent has proved most effective in recovery of active and stable antibodies from the agarosebound virus.

Agglutinins↗
PubMed1976

Kappa chain (V kappa III) subgroup-related activity in an idiotypic anti-cold agglutinin serum.

In a search for H- or L-chain-related cross-idiotypic specificity among human anti-I and anti-i cold agglutinins, two idiotypic antisera raised against the IgMkappa cold agglutinin Da were tested for their binding activity to isolated cold agglutinin H and L chains. Negligible H-chain binding activity was found, but there was high-titre L-chain binding activity in one of the antisera. This was an unsuspected VkappaIII subgroup activity which enabled the classification of VkappaIII proteins into three subgroups. The kappa chains of five out of six anti-I and anti-i cold agglutinins belonged to the antigenically most active VkappaIII subgroup. Absorption of the idiotypic antiserum with a Bence Jones protein of this latter subgroup did not appreciably alter the precipitating cross-idiotypic activity of the antiserum when tested with intect cold agglutinins. However, these studies do not rule out the possible existence of a VkappaIII subgroup-associated conformational antigen in an intact Fab region, which is seen as a 'cross idiotypic' antigen by heterologous (rabbit anti-human) antisera.

Agglutinins↗
PubMed1976

[Decrease in maximum consumption of oxygen after blockage of beta-andrenergic receptors].

VO2 max, maximum oxygen uptake, has been measured in 4 normal young men, before and after beta-adrenergic blockade (0.5 to 5 mg Pindolol by mouth). Pindolol induces bradycardia and reduces VO2 max. A statistically significant positive correlation appears between posology of Pindolol and bradycardia, this posology and reduction of VO2 max, and finally between bradycardia and reduction of VO2 max. These correlations indicate that the reduction of VO2 max is best explained by a circulatory limitation of oxygen supply to active muscles.

Adult↗
PubMed1976

[Antigenicity of drugs used in anesthesiology].

The authors studies the factors involved in the antigenicity of the principal medications used in anaesthetics, including general anaesthesia, local anaesthetics and muscle relaxants. Any attempt at establishing a correlation between the chemical properties of these medications and their haptenic power would seem difficult by virtue of the fact that the complications seen in clinical practice are characterised by their rarity. The latter may be explained either on the basis of a low haptenic power of the substances or by the fact of their administration which is rarely repeated after a short time interval. Finally, the difficulties of this correlation are even further increased by the fact that the haptenic power is not always due to the medication itself, but sometimes to one of its metabolites.

Anesthetics↗