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Biomedical subjects

C Vigneron

Publications and source records attributed to C Vigneron.

At least 109 records · Page 6Linked to original sources
PubMed1983

Stability and functional properties of haemoglobin freeze-dried in the presence of four protective substances after prolonged storage: dose-effect relationships.

Freeze-dried haemoglobin samples protected during the desiccation by sucrose, arginine aspartate, lysine aspartate, sodium-zinc EDTA and Ficoll 70 have been stored under air at 4 degrees C for 15 months. The analysis showed that sufficient concentrations of sucrose and of the amino-acid salts prevent the oxidation of haemoglobin and maintain its functional properties. Relationships between the concentrations of these compounds and the methaemoglobin levels before and after storage were calculated. They define theoretical concentration points where methaemoglobin would not be found after storage. Sucrose is slightly more effective than the amino-acid, but oppositely, EDTA and Ficoll 70 do not allow prolonged storage of freeze-dried haemoglobin.

Amino Acids↗
PubMed1982

Association of del(11)(p15.1p12), aniridia, catalase deficiency, and cardiomyopathy.

We report another patient with del(11p) and aniridia, catalase deficiency, and cardiomyopathy. This association is confirmed from a review of previously reported cases. Since other dysplasias are known in this syndrome, the hypertrophic cardiomyopathy in del(11p) children may also represent an abnormality of tissue development.

Abnormalities, Multiple↗
PubMed1982

Homozygous deletional alpha + thalassaemia associated with unequal expression of the two remaining alpha 1 genes (alpha 1A and alpha 1Q).

A Cambodian family presenting several haemoglobinopathies, Hb E, Hb Q and alpha + thalassaemia, has been investigated. DNA analysis showed that the thalassaemia syndrome corresponds to a leftward type (4.2 kb) deletional form of alpha + thalassaemia. Genotypes found in the family are: propositus -alpha A/-alpha Q, beta A/beta E., mother and older sister alpha A alpha A/-alpha Q, beta A/beta E., father alpha A alpha A/-alpha A, beta A/beta A. The propositus consistently presents an alpha Q/alpha A chain ratio of 60/40 although both chains are products of alpha 1 loci. The relatively higher expression of the alpha Q chain is not observed in the mother and therefore makes it unlikely to reflect anything other than differential expression of the maternal -alpha Q/ and paternal -alpha A/ haplotypes. This observation raises the possibility that both haplotypes are not strictly identical and that the region of the cross-over event is important for alpha gene expression.

Chromosome Deletion↗
PubMed1981

Freeze-drying of hemoglobin solutions without adjuvant and in presence of glucose, tris, and beta-alanine: a study by electron spin resonance of the oxidized compounds produced.

Hemoglobin cannot be freeze-dried without the presence of protective compounds. Carbohydrates are a well-known example of such compounds, but we have shown that some amine buffer and amino acids are also very effective. The mechanism of action of all these molecules is unknown. We report here experimental data showing that the protective effect is not the result of a direct bond between iron and the protective compound added.

Absorption↗
PubMed1981

[Functional characteristics of granulocytes separated by haemonetic cytapheresis (author's transl)].

Granulocytes have been transfused systematically for several years owing to the utilisation of cells separators. It seems profitable to test these granulocytes from a functional standpoint since they are centrifuged and then collected in plastic bags. Several function tests are used and demonstrate that the quality of these granulocytes is on the average diminished without altering them significantly. Morphological studies complementing these qualitative studies demonstrate membrane fusions and partial degranulation.

Granulocytes↗
PubMed1980

[Effect of the addition of albumin on the preservation of hemoglobin solutions lyophilized in the presence of glucose].

In the case of the clinical use of hemoglobin solution, the possibility of storing this preparation in the lyophilized state will be very useful. Freeze-dried preparations containing glucose alone or associated with albumin (25. 50. 75. 100 g/1) have been stored under air in darkness at room temperature or + 4 degrees C. At room temperature, the study has been stopped after one year in consideration of the important oxidation and denaturation of hemoglobin. The samples stored at low temperature have been studied after two years. With glucose alone, freeze-dried hemoglobin has generally a better stability than the four albumin containing preparations in the different assays (methemoglobin and oxyhemoglobin levels, Hill number, shape of the Barcroft's curve). The p 50 and the oxyphoric capacity are always low. Our hypothesis of an enhancement of hemoglobin stability by albumin in presence of glucose is not confirmed; the denaturation is in correspondence with the albumin concentration.

Freeze Drying↗
PubMed1979

Attempts to use carbodiimide (EDCI) to cross-link hemoglobin for transfusions.

The polymerization of hemoglobin for use as a blood substitute and an oxygen carrier would be of interest because high-mol. wt macromolecules would have a longer vascular retention time than the monomer. We found that the molecules resulting from the treatment of hemoglobin with ethyldimethylaminopropylcarbodiimide did not have a higher mol. wt than free hemoglobin and also had a dissociation curve resembling that of monomers, but seemed more stable.

Carbodiimides↗
PubMed1979

Isoelectrofocusing of erythrocyte galactose 1 phospho uridyl transferase in a family with both galactosemia and Duarte variants.

A family with the presence of the genes for both galactosemia and the Duarte variant is described. Galactose 1 phospho uridyl transferase has been studied not only by electrophoresis on starch gel, but also by isoelectro-focusing on thin-layer acrylamide. Normal and variant transferases were resolved into three bands, the isoelectric point of which was between 5.40 and 5.10 for the normal subjects, and between 5.25 and 4.95 for subjects with the Duarte variant.

Adult↗