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Biomedical subjects

J Constans

Publications and source records attributed to J Constans.

At least 181 records · Page 10Linked to original sources
PubMed1981

Gc, Tf, Hp subtype and alpha 1-antitrypsin polymorphisms in a Pygmy Bi-Aka sample.

Protein polymorphism is studied in more than 900 serum samples during different investigations conducted in a Bi Aka Pygmy group. The Gc, Tf and alpha 1-antitrypsin subtype polymorphisms were determined after isoelectric focusing while the haptoglobins alpha and alpha 2-peptides were studied on PAGE. A high frequency of the Hp2 gene is noted while Hp1F and Hp1S gene frequencies are similar. According to the Gc1S and Gc2 gene frequencies this group falls within the cluster of the melanoderm populations such as the Sara, Bantu and Peulhs. The two subtypes of TfC1 and TfC2 are present in this sample. TfC3 is absent. The TfD1 variant frequency is one of the highest observed in African groups. The alpha 1-antitrypsin polymorphism corresponds to the presence of the three PiM subtypes. No other variants are observed, neither PiS nor PiZ. For the first time a highly significant association is described between the TfD1 and Gc1A1 (GcAb) genes. Family pedigrees do not permit the ascertainment of the linkage between the two loci.

Black People↗
PubMed1981

Haptoglobin polymorphism among Saharian and West African groups. Haptoglobin phenotype determination by radioimmunoelectrophoresis on Hp O samples.

The haptoglobin (Hp) polymorphism is investigated in 11 African groups living in an area from the Algerian Sahara to Central Africa. More than 4,000 samples were examined. In the Saharian samples, the Hp1 gene frequency is higher than in any other African group. From north to south, a decrease in the Hp1 gene frequency is observed; in the Pygmy sample only, this frequency is lower than the frequency of the Hp2 gene. By means of a sensitive radioimmunoelectrophoresis, the presence of a residual Hp in Hp O sera in which the Hp polymorphism can also be determined can be revealed. Absence of Hp 1-1 and significant excess of Hp 2-2 individuals were observed. More Hp 2-1M phenotypes were detected in the Hp O population than in the non-Hp O population examined. In the Hp O samples, the influence of the phenotype distribution on the Hp gene frequencies is discussed. The heavy polymers of the Hp related to the presence of the alpha 2 chain (Hp2 gene product) are involved only in the biological mechanisms responsible for the presence of Hp O and Hp 2-1 M phenotypes among African groups.

Africa, Central↗
PubMed1980

Gc (vitamin D binding protein) subtype polymorphism and variants distribution among Saharan, Middle East, and African populations.

This article presents the results obtained by electrophoretic analysis of the group specific component polymorphism in more than 1,250 serum samples from populations living in the Sahara, the Middle East, and equatorial Africa. In addition to the alleles Gc1F and Gc1s, five variants, including one previously unknown, were found. The distribution of the alleles herein described permits speculation on exchanges and relations among the groups considered. The lowest frequencies of the gene Gc2 correspond to regions where sunlight is stronger. There is also a north-south gradient in the Gc1F gene frequency. This seems to parallel the gradient seen in skin pigmentation.

Africa, Northern↗
PubMed1980

A new procedure for the determination of transferrin C (Tf C) subtypes by isoelectric focusing. Existence of two additional alleles, Tf C4 and Tf C5.

Isoelectric focusing (IEF) is widely used for the determination of serum protein polymorphisms in forensic investigations. Because of non-genetic heterogeneity of some proteins and of protein-ligand dissociation observed after IEF standardization of procedures is necessary. In this article the authors point out the main difficulties encountered in studying the transferrin subtype polymorphism and describe a new and sensitive method. Two new Tf C subtypes were observed: Tf C4 in North American, Bolivian and Brazilian Indians, Tf C5 in Black Americans, both with polymorphic allele frequencies. In a Pyrenean population the allele frequencies for Tf C1, Tf C2 and Tf C3 were quite similar to those observed in a German population sample.

Alleles↗
PubMed1980

Pi M4: an additional Pi M subtype.

The authors studied Pi polymorphism using the Separator isofocusing method with slight modification. A new Pi allele was observed. Family pedigrees confirmed co-dominant inheritance with other Pi alleles. According to the electrophoretic mobility of its isoprotein bands, and to its frequency (0.04) this new allele is considered as a fourth Pi M subtype: Pi M4.

Alleles↗
PubMed1980

HLA-a, B typing in Basque and other Pyrenean populations.

Fourteen HLA-A and 18 HLA-B antigens were studied in three samples of Pyrenean populations: 198 unrelated individuals of a "Pays Basque" group; 212 non-Basque individuals from a valley in Bearn, l'Ouzom; and 73 non-Basque individuals from the neighboring valley of Bareges. The results in the Basque and the non-Basque people from l'Ouzom were comparable: the gene frequencies of HLA-A29, Aw19.2, B17 were increased and the haplotypes HLA-Aw19.2, B18; A29, B12; A2, B5; A1, B17 were found frequently with a striking linkage disequilibrium; HLA-B18 had an increased gene frequency in all these Pyrenean populations, while Bw35 was frequent in l'Ouzom and Bareges, but not among the Basques. The characteristics of Bareges were very different: the gene frequencies of HLA-A2, A11, B7 were increased while the frequency of HLA-B5 was low; the most characteristic haplotypes were HLA-A2, B12; A2, B18; A11, Bw35; A11, B27. It is interesting to note discrepancies between ethnic and HLA classification of the Basques and the non-Basque population of l'Ouzom. The HLA characteristics are quite different in the Hareges sample, more closely resembling those of Northern Europe.

Ethnicity↗
PubMed1980

High frequency of the properdin factor Bf F1 and its linkage to HLA in French Basques.

We studied 201 unrelated French Basque individuals for HLA and Bf polymorphisms. The haplotypes of eighty-seven of them were deduced from family studies. The results show the frequency of the Bf F1 allele (0.1393) which is the highest one currently reported. They confirm the high frequencies of HLA-Aw19.2 and B18 previously reported in that population and show that a whole haplotype with strong linkage disequilibria, namely Aw19.2, Cw5, B18, Bf F1, DRw3 is frequent. On the other hand, the gene frequency of Bf S is decreased (0.5497) as compared with the other European Caucasoïd populations, while a slight increase in the Bf F gene frequency (0.2960) appears. These results point out that it is of importance to consider the genetic background choosing the population where linkage disequilibria are to be studied.

Alleles↗
PubMed1980

Study of red blood cell and serum enzymes in five Pyrenean communities and in a Basque population sample.

Until recently, no data on genetic polymorphisms in the populations living on the northern side of the Pyrenees have been available, except for the Basques. Several investigations were done lately on rural communities in various geographic zones in the Pyrenees from the eastern to the western part. In this paper, the results for the following enzyme polymorphisms are reported: acid phosphatases, AK, ADA, PGM1 and PGM2, 6PGD, NADH diaphorase, SOD, MDH, TGP, G6PD, C5 esterase (E2 locus), serum cholinesterase (E1 locus). Significant variation in gene frequencies was observed over the distinct geographic zones for the main polymorphic system. Furthermore, some rare alleles were found: a new G6PD variant (Luz-Saint-Sauveur), the presence of ADA3 and ADA5 alleles in two groups of the Central Pyrenees, a Dia2 gene among Basques and in the Pays de Sault, a high rate of Ea1 allele in the Basque group. The values obtained for the degree of heterozygosity are in agreement with the relative isolation of the different groups studied and confirm the importance of sociocultural factors in the evolution of the genetic background of rural communities in Europe.

Acid Phosphatase↗
PubMed1980

Erythrocyte glyoxalase I and esterase D polymorphisms in four French populations.

The genetic polymorphism of two new erythrocyte markers GLO I (EC 4.4.1.5) and esterase D (EC 3.1.1.1) has been investigated in four French populations: Basques and Toulouse groups (southwest area), Lille and Strasbourg (northern and eastern part of the territory). The distribution of GLO I and EsD alleles within these communities has shown some significant differences. Basques samples are characterized by the highest frequency of EsD1 gene (0.911) and the lower rate of GLO1 (0.364). The observed data are compared with other results previously reported in France and in Western European populations.

Electrophoresis, Starch Gel↗
PubMed1980

Familial alpha-1-antitrypsin dificiency with Pi-Z and a new Pi-Gcler variant.

A case of familial deficiency in alpha-1-antitrypsin connected with Pi-0Z gene led to the finding of a new Gcler variant partly deficient, the electrofocusing pattern of which, located between that of G and I variants, was modified after neuraminidase digestion. A study of three generations shows that Gcler variant is transmitter according to an autosomally codominant mode. Moreover serum trypsin inhibitory capacity and concentration of ten proteins have been measured in this family. Except the known relation between serum alpha-1-antitrypsin level and trypsin inhibitory, capacity, only serum IgA showed a significant correlation with serum alpha-1-antitrypsin in the deficient group with Pi-Z allele.

Blood Proteins↗
PubMed1980

[Polymorphism of plasma cholinesterase in Pyrennees populations. Problems in geographic hematology and pharmacogenetics].

Plasma cholenesterase is classified among blood markers whose genetic variation in man was discovered during past years. To look broadly at the characteristics of this system two main fields are now well established: geographical hematology and pharmacogenetics. In the present work the results of the study of that enzyme are reported in 2 400 individuals belonging to distinct Pyrenean communities. On geographical hematology the data obtained show the existence of a genetic polymorphism, the extent of which has a significant variation in the different areas. The E1a gene reaches the highest frequency (7.7%) in the central part of the Pyrénées (Lux Saint-Sauveur Valley): the rate decreases in Toulouse (3%) and in the Basques (2.3%). The E1s allele was found in the Basques with a frequency of 2.13% value which gives a peculiar feature to this group when compared to other Pyrenean populations. The E1f gene was seldom discovered in the samples studied. These data fill a gap in mapping the distribution of blood markers in France. On pharmacogenetics, the gene frequencies observed at the E1 locus were used for the likelihood of findings genotypes with a sensitivity to suxamethonium or other chemicals. Such a sensitivity cannot be underestimated in some groups (central part of Pyrénées, Basques). In medical practice a molecular abnormality of cholinesterase may be detected after apnea due to suxamethonium administration during anesthesia or in some cases of toxic syndromes induced by chemical compounds (agricultural or industrial products), inhibition of Cholinesterase.

Alleles↗
PubMed1978

[Study of the Gc protein in several French population samples : genetic polymorphism by isoelectrofocusing and quantitative results].

The authors describe the results obtained in an examination by isoelectrofocusing of more than 1,000 serum samples from various regions in France. The autochthonous populations of the north side of the Pyrénées are characterized by a high frequency of the gene Gc2 and a very low frequency of the Gc1F gene. This distinguishes them from the other groups studied (southwestern, northwestern and eastern France). The quantitative analysis of the data emphasizes the difference. These results can only be explained by the interdependance of the genetic and metabolic factors.

Adult↗
PubMed1978

Analysis of the Gc polymorphism in human populations by isoelectrofocusing on polyacrylamide gels. Demonstration of subtypes of the Gc allele and of additional Gc variants.

For the study of the group-specific component (Gc) system, serum samples were examined by polyacrylamide gel electrophoresis and by a newly developed immunofixation isoelectrofocusing procedure. Thereby, a greater extent of polymorphic variation was revealed than was known previously. The allele Gc1 could be subdivided into the alleles Gc1F and Gc1S. The distribution of Gc1 subtypes was very different in three populations (Pygmies, Amerindians, and Pyreneans) examined. New variants of the Gc1 and Gc2 genes were also described in the Amerindians and in the Pygmy population, respectively.

Alleles↗
PubMed1978

GcT (Toulouse): a fast variant of the groupspecific system in an Pyrenean family.

In the course of a genetic investigation carried out in a Pyrenean population, a family with a new allele of the Gc system was found. Electrophoretic analysis revealed a faster migrating variant with a double band pattern. Presumably, this variant represents a mutant of the Gc1 allele. The variant is transmitted as an autosomal codominant trait. This additional allele at the Gc locus is named GcT (TcToulouse).

Alpha-Globulins↗