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J Sevin

Publications and source records attributed to J Sevin.

17 recordsLinked to original sources
PubMed1995

The human myelin oligodendrocyte glycoprotein (MOG) gene: complete nucleotide sequence and structural characterization.

Human myelin oligodendrocyte glycoprotein (MOG), a myelin component of the central nervous system, is a candidate target antigen for autoimmune-mediated demyelination. We have isolated and sequenced part of a cosmid clone that contains the entire human MOG gene. The primary nuclear transcript, extending from the putative start of transcription to the site of poly(A) addition, is 15,561 nucleotides in length. The human MOG gene contains 8 exons, separated by 7 introns; canonical intron/exon boundary sites are observed at each junction. The introns vary in size from 242 to 6484 bp and contain numerous repetitive DNA elements, including 14 Alu sequences within 3 introns. Another Alu element is located in the 3'-untranslated region of the gene. Alu sequences were classified with respect to subfamily assignment. Seven hundred sixty-three nucleotides 5' of the transcription start and 1214 nucleotides 3' of the poly(A) addition sites were also sequenced. The 5'-flanking region revealed the presence of several consensus sequences that could be relevant in the transcription of the MOG gene, in particular binding sites in common with other myelin gene promoters. Two polymorphic intragenic dinucleotide (CA)n and tetranucleotide (TAAA)n repeats were identified and may provide genetic marker tools for association and linkage studies.

Base Sequence↗
PubMed1994

Comparison of psychotic and autistic children using behavioral observation.

The purpose of this study was to assess the relationship between autism and childhood psychosis. Fifteen children with psychotic symptoms were compared to 15 children with autism, using two observational measures, the Ritvo-Freeman Real Life Rating Scale (RLRS) and the Childhood Autism Rating Scale (CARS), which rate subjects on behaviors pathognomic to autism. In comparison to autistic persons, psychotic individuals were judged to have better language and social skills. In addition, autistic persons were also rated as having more difficulty adapting to new situations and appeared more "autistic-like." Overall scores on the CARS and RLRS were significantly different between the two groups, indicating that these two assessment instruments may be useful in differential diagnosis. However, 20% of the psychotic subjects received pervasive developmental disorder diagnoses, indicating that there may be a relationship between those two disorders.

Autistic Disorder↗
PubMed1993

An alternative method for T-cell receptor repertoire analysis: clustering of human V-beta subfamilies selected in responses to staphylococcal enterotoxins B and E.

We have designed a convenient procedure for the analysis of V beta repertoire expression in polyclonal T-cell populations. In this procedure T-cell RNA is converted to cDNA, polydC-tailed with terminal deoxynucleotidyl transferase and submitted to one-side specificity PCR amplification with a constant region oligonucleotide primer. The amplified material is then analysed by reverse spot-test hybridization: after 32P-labelling, the amplification product is put to hybridize on a membrane where specially designed V beta subfamily-specific probes are immobilized. The radioactivity fixed on each probe can then be easily quantified and the signal obtained is directly proportional to the initial amount of homologous RNA. We applied this technique to the study of V beta gene selection following T-cell stimulation by staphylococcal enterotoxins B and E. We show that with these toxins two almost non-overlapping sets of T-cells are recruited and that this selection is likely to be dependent on specific amino acid residues shaping the fourth complementarity determining region of the TCR-beta chain. These residues constitute two tandemly-conserved tripeptide sequences (Asp39Pro40Gly41)-(Val69Ser70Arg71) and (Arg66Phe67Ser68)-(Asp88Ser89Ala90) in the SEB- and the SEE-responsive V beta gene clusters respectively.

Amino Acid Sequence↗
PubMed1991

Phosphoglucomutase-1 subtypes in two populations in Adriatic islands: presence of PGM1*W3 (PGM1*7+) allele.

Allele frequencies at the phosphoglucomutase-1 (PGM1) locus have been investigated in two Croatian (Yugoslavian) populations from neighboring islands, Silba and Olib. The genotype distributions are significantly different though the two islands are only 2 km apart. In the light of demographic and historical data, a few hypotheses explaining these results are discussed. A rare variant, PGM1*W3, usually found in Asia, is present in 4 inhabitants from the Olib island.

Alleles↗
PubMed1989

Human red-cell acid phosphatase (ACP1): a new mutant (ACP1*KUK) detected by isoelectric focusing, kinetics of thermostability and substrate activity.

A new rare mutant of the red-cell acid phosphatase (ACP1) is described using conventional gel electrophoresis and isoelectric focusing migration. According to the electrophoretic patterns obtained, the new mutant ACP1* KUK is different from the ACP* H and ACP1* A' variants already described. The enzyme activities and the thermostability curves definitively confirm the existence of a new variant. The transmission of this mutant was followed through a pedigree of three generations. The family originated from Czechoslovakia. The frequency of the variant is probably less than 0.001.

Acid Phosphatase↗
PubMed1988

Population polymorphism of the GLO1 enzyme. Identification of two new variants.

A new electrophoretic technique for the determination of the glyoxalase I (GLO1) polymorphism on mixed agarose and starch gel is applied to the genetic study of "Provinces Françaises" and some other human populations. Four rare electrophoretic variants are revealed; two of them (GLO1*4, GLO1*5), both new, are discussed. In the "Provinces Françaises" the mating GLO1 2-1 x GLO1 2-1 shows an irregular segregation of the GLO1 alloenzymes.

Africa, Western↗
PubMed1981

Isoelectric focusing of human phosphoglucomutase: data on the distribution of variant phenotypes in three population sample from South West France.

Leukocyte lysates obtained from blood specimens of individuals from Central and Western Pyrenean groups (Barèges and Basques) and from the population of Toulouse city have been typed for PGMa1 isozymes using isoelectric focusing (pH range: 3-9.5) in polyacrylamide gels. The determination of usual PGM1 phenotypes was simultaneously performed on red cells by starch gel electrophoresis. Significant differences were found between the three communities. In Barèges samples only 6 of the 10 phenotypes known at PGMa1 locus have been observed. In the same group, 36 mating types were studied in distinct families. The segregation of the phenotypes in an agreement with the codominant inheritance of the alleles. In Basques the gene frequencies showed intermediate values between Toulouse and Barèges. PGMa2 reaches a higher frequency in the latter community (0.306). In the Toulouse population sample the results are comparable with those previously published in western Europeans. The present data provide additional information on the usefulness of the new PGM system detected by isoelectrofocusing in human genetics.

Electrophoresis, Polyacrylamide Gel↗
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

[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↗
PubMed1979

Population genetic studies of the Aka pygmies (Central Africa): a survey of red cell and serum enzymes.

Blood samples collected in a single Pygmy tribe, the Aka, living in Bokoka district (Central African Empire) were investigated with respect to the phenotype and gene frequencies of the following 12 enzyme systems: acid phosphatase, adenosine deaminase, adenylate kinase, carbonic anhydrase, esterase D, glucose-6-phosphate dehydrogenase, malate dehydrogenase, phosphoglucomutase 1, phosphoglucomutase 2, phosphogluconate dehydrogenase, superoxide dismutase and serum cholinesterase variants (locus E1 and E2). The data obtained in the study of genetic polymorphisms of this isolated and inbred population show a specific pattern with the following characteristics: the very low frequency of PGDB and pa alleles; the existence of two rare PGM variants at the PGM2 locus, typical PGM26Pyg (4.2%) and PGM29 (0.2%); the high frequency of the pr allele (10.8%) and CAII2 (8.22%) and ESD2 genes (18.4%). Furthermore, at the G6PD locus four distinct alleles have been found: the negroid GdA- (4%) and GdA+ (16%), the common GdB+ (79.2%)--, and the rare Gd+Ibadan Austin (0.7%). Cholinesterase typings disclosed the presence of the uncommon E1f and E1s genes distributed within a single breeding unit. The results are compared with other data previously reported on South African Khoisan and some Negroid populations; the particular genetic background of Pygmies is discussed.

Black People↗
PubMedDate not supplied

Plasma cholinesterase variants in population samples from south-west France.

The results of a study of distribution of plasma cholinesterase types in some Pyrenean groups (south-west of France) are reported. The samples examined were collected in several rural communities. The individuals tested were natives from the different areas. The data show significant differences between the geographic zones. At E1 locus the frequency of Ea1 gene reaches higher values in Luz Saint-Sauveur valley (7.7%). Among Basques and other groups this allele remains in the range of other caucasoid populations. A relatively high frequency of Es1 allele (2.1%) is found in Basques. The Ef1 gene was only found at a low rate in one community. At E2 locus, E+2 frequency is roughly similar to the values observed in Europeans except for Basque, Capcir and Toulouse people who share significantly lower values.

Adult↗
PubMedDate not supplied

Comparison of TCR-alpha beta sequences of cross-reactive anti-DR alloreactive T-cell clones: identification of possible contact residues based on charge complementarity between TCR chains and DR determinants.

We analysed alloreactive T-cell clones selected for their differential recognition of DR variants differing in the third hypervariable region (hvr) of the DRB1 gene (amino acid positions 67-70-71). This polymorphism leads to two main hvr3 types: a basic form (Leu67-Gln70-Arg/Lys71) and an acidic form (Ile67-Asp70-Glu71) where residue 70 is probably directly accessible to the TCR on DR beta chains. The TCRs have been sequenced. Three DRw13-reactive clones use similar V alpha 2 and V beta 13 gene family members but differ mainly by their cross-reactivity towards acidic or basic DR4 variants and by the sequence of CDR3 on their TCR alpha and/or beta chains. One anti-DRw13 clone cross-reacts with most specificities sharing the DRw13 type of hvr3 and reciprocally one anti-DRBon (DRB1*0103) clone cross-reacts with DRw13. These two clones use similar V beta genes and share negative charges in CDR2 alpha at position 56. They also share these negative charges in CDR2 alpha with two other clones reacting specifically with DRBon, the acidic variant of DR1. We hypothesized that the selective recognition of positively or negatively charged residues on the DR beta chain would necessitate reciprocal charges on the TCR complementarity determining regions (CDRs) responsible for this interaction. This facilitated identification of those residues of the TCR that possibly interact with the hvr3 determinant of HLA-DR. From these observations the mechanisms allowing the recognition of alloantigens by these T-cell clones are discussed.

Amino Acid Sequence↗
PubMedDate not supplied

Abnormal T cell receptor V beta gene expression in the peripheral blood and synovial fluid of rheumatoid arthritis patients.

OBJECTIVE: The aim of this study was to assess T cell receptor V beta-gene expression in the peripheral blood and synovial fluid of rheumatoid arthritis patients. METHODS: Cytometric analysis was performed on peripheral blood and synovial fluid lymphocytes from 12 patients using a restricted set of V beta-specific monoclonal antibodies (to V beta 5.1-3, V beta 6.7 and V beta 8). In 5 patients the expression of the V beta 1 through V beta 20 gene families was also analysed, using a recently described method based on a one-side-specificity polymerase chain reaction coupled to reverse dot hybridization. RESULTS: Cytometric analysis failed to show any consistent difference in the expression of V beta 5, 6 and 8 between the two compartments on the one hand, or between the peripheral blood of normal individuals and patients on the other hand. The PCR/dot hybridization method did not demonstrate a significant difference in the V beta repertoires between peripheral blood and synovial fluid samples from arthritis patients. However, in all patients the V beta 6, 13 and/or 14 families were expressed to a high level, so that these families frequently represented over 40% of the V beta 1-20 repertoire in both compartments, instead of the approximately 20% seen in normal peripheral blood samples. CONCLUSION: We conclude that V beta 6, 13 and 14 are overexpressed in both the peripheral blood and synovial fluid of rheumatoid arthritis patients compared to normal samples.

Arthritis, Rheumatoid↗