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Biomedical subjects

C Fortier

Publications and source records attributed to C Fortier.

At least 19 recordsLinked to original sources
PubMed2002

Two novel CD1 E alleles identified in black African individuals.

CD1 gene (CD1A to CD1E) products are involved in non-peptide antigen presentation, such as lipids and glycolipids, to T cells. With a similar function to MHC, namely antigen presentation, these genes nevertheless displayed a much lower level of polymorphism as compared to MHC. We report here two additional CD1E variants identified in black African individuals, designated herein CD1E*05 and CD1E*06. While the former differs from the common (wild type) allele sequence by two substitutions at nucleotide positions 217 and 229 of exon 2, the latter only by a single base change at position 91 of exon 3. These substitutions lead to amino acid changes at position 73 and 77 of the alpha1 domain in the former and at position 30 of the alpha2 domain in the latter. Identification of these additional variants suggests that the CD1 locus, especially the CD1E gene, is much more polymorphic than previously assumed.

Africa↗
PubMed2001

A new HLA-Cw allele (Cw*1510), identified in a French Caucasian individual.

A novel HLA-Cw*15 allele, Cw*1510, found in a French Caucasian bone marrow recipient is described. Nucleotide sequence of the new variant is identical to the common Cw*15021 DNA sequences except nucleotides at positions 32 and 61 of exon 2. While the first difference is silent, the second cause substitution of an Histidine by an Arginine at amino acid position 21 of the alpha1 heavy chain domain.

Alleles↗
PubMed2000

A novel HLA-B*39 allele (HLA-B*3916) due to a rare mutation causing cryptic splice site activation.

A novel HLA-B*39 variant, found in an African patient with sickle cell anemia undergoing bone marrow transplantation is described. Initially suspected by inconsistent serological typing (B-blank, Bw6), then recognized by PCR-SSP, and finally characterized by nucleotide sequencing, this novel allele is designated HLA-B*3916. It differs from HLA-B*3910 by a point mutation (G to C) at position 17 of exon 3 causing glutamine to histidine change at codon 96 of alpha(2) domain, a conserved position among HLA class I alleles. cDNA sequence analysis further revealed the presence of both normally and abnormally spliced mRNA species in established cell lines. The abnormal species correspond to partial truncation of exon 3 presumably due to the nucleotide change in exon 3, which constitutes a new consensus acceptor splice site within this exon. We postulate that the observed blank is essentially the consequence of qualitative change in a critical region of this novel antigen as abnormal mRNA species are relatively less abundant than normal species. Because the residue 96 of the HLA class I heavy chain is directly involved in interaction with alpha(2)m, another interesting possibility is that an aminoacid change in this position would perturb such interaction and consequently could affect the serological specificity of B*3916, or its expression or both.

Amino Acid Sequence↗
PubMed2000

A novel HLA-B*51 allele (B*5116) identified by nucleotide sequencing.

We report here an additional HLA-B*51 variant designated HLA-B*5116. Detected by an abnormal serological reactivity pattern, this variant was identified as a B*51 allele by polymerase chain reaction using sequence-specific primers (PCR-SSP) and characterized by nucleotide sequencing. The new variant sequence match closely with the classical HLA-B*5101 excepted two adjacent nucleotide substitutions at positions 216 and 217 of the third exon and the subsequent Leucine to Glutamic acid change at codon 163 of the alpha2 domain (CTG-->GAG). This new variant was not detected in three different ethnic groups (French, Algerian and Lebanese) suggesting a very rare frequency.

Alleles↗
PubMed1999

Characterization of a novel HLA-Cw*04 variant in a Laotian family: HLA-Cw*0406.

The sequence of a new HLA-Cw*04 allele has been identified in a Laotian family. This allele, designated Cw*0406, differs from Cw*0403 by a single nucleotide substitution at codon 156 (CGG-->CTG) in the alpha2 domain, leading to an amino acid change from Arginine to Leucine. Further screening by specific amplification of two ethnically different populations, i.e. French (n=150) and Lebanese (n=100), provided no case of Cw*406, suggesting that the distribution of this allele may be restricted.

Alleles↗
PubMed1995

HLA-Cw allele analysis by PCR-restriction fragment length polymorphism: study of known and additional alleles.

We describe a technique for HLA-Cw genotyping by digestion of PCR-amplified genes with restriction endonucleases. Locus-specific primers selectively amplified HLA-Cw sequences from exon 2 in a single PCR that avoided coamplification of other classical and nonclassical class I genes. Amplified DNAs were digested with selected enzymes. Sixty-three homozygous cell lines from International Histocompatibility Workshop X and 113 unrelated individual cells were genotypes for HLA-Cw and compared with serology. The present protocol can distinguish 23 alleles corresponding to the known HLA-Cw sequences. Genotyping of serologically undetectable alleles (HLA-Cw Blank) and of heterozygous cells was made possible by using this method. Six additional HLA-Cw alleles were identified by unusual restriction patterns and confirmed by sequencing; this observation suggests the presence of another family of allele-sharing clusters in the HLA-B locus. This PCR-restriction endonuclease method provides a simple and convenient approach for HLA-Cw DNA typing, allowing the definition of serologically undetectable alleles, and will contribute to the evaluation of the biological role of the HLA-C locus.

Alleles↗
PubMed1993

Acquired resistance and persistence of Candida albicans following oral candidiasis in the mouse: a model of the carrier state in humans.

In our experimental model of oral candidiasis in the CD1 mouse, the primary infection showed reproducible Candida overgrowth kinetics with a peak level on day 5 of the infection. After day 7, the population stabilized at about 300 colony-forming units per excised mucosal tissue. The primary infection triggered an inflammatory response that resolved in under 8 days. At this point, the histological pattern of the mucosa reached a new equilibrium between recruited and resident mononuclear cells. The primary infection also rapidly stimulated cellular immunity, as measured from day 4 by a delayed-type hypersensitivity footpad reaction. Following a second topical challenge with Candida 30 days after the primary infection, the infection was barely detectable and a typical local delayed-type hypersensitivity reaction occurred between 24-72 h. It is proposed that acquired resistance, in conjunction with low-level persistence of Candida in our model, mimics the carrier state in sensitized humans.

Animals↗
PubMed1990

Experimental oral candidosis in the mouse: microbiologic and histologic aspects.

A model of oral candidosis was developed in order to investigate histologic and microbiologic aspects of this host-parasite interaction under controlled experimental conditions. Normal adult CD-1 mice were inoculated by the topical application of 10(8) Candida albicans blastospores, and oral colonization was monitored by the quantitative culturing of saliva samples and of digested oral mucosa. Tissue sections of the mucosa were examined in a kinetic study ranging from 2 h to 13 days postinoculation. We report here that oral colonization by C. albicans can be induced in normal adult mice without the use of any compromising agent and that the animals recover from this mucosal infection following a reproducible pattern. Temporal analysis of the oral histopathology showed that distinct patterns of inflammation are associated with particular stages in the development of the infectious foci. This experimental model offers a means of further investigating the host-parasite interactions involved in the onset and development of oral candidosis.

Animals↗
PubMed1990

Two neglected categories of immigrants to Canada: temporary immigrants and returning Canadians.

Results are presented from an attempt to improve Canadian statistics on international migration so as to comply with U.N. guidelines by including data on long-term residents with temporary status and Canadian citizens and permanent residents returning from abroad. "The estimation procedures involve extensive operations on three Canadian administrative data systems: the Visitors Immigration Data System of Employment and Immigration Canada; the Family Allowances Files of Health and Welfare Canada; and the Customs and Excise Files of Revenue Canada. These data are used to produce the number of immigrants in both of the neglected categories, as well as to calculate the geographic (origin and destination) and demographic (sex, age, marital status) structures of these groups. Results of the analysis of estimates for the period 1982-1988 show that, due to their size and characteristics, both of these neglected categories of immigrants constitute a significant part of immigration to Canada, and their importance has and will continue to increase over time."

Americas↗
PubMed1989

The limits of the DNase I-sensitive domain of the human apolipoprotein B gene coincide with the locations of chromosomal anchorage loops and define the 5' and 3' boundaries of the gene.

In eukaryotic cells, chromatin is organized as domains or loops that are generated by periodic attachment of the chromatin fiber to protein components of a nuclear matrix, or scaffold. These chromosomal loops may have a function in gene regulation. The length of the chromatin domain encompassing the human apolipoprotein B gene was studied by determining the locations of nuclear matrix attachment sites as well as the boundaries of the DNase I-sensitive domain in cells that express the gene (such as HepG2 and CaCo-2 cells) and in those that do not (HeLa cells). Three nuclear matrix attachment regions (MARs) of the human apolipoprotein B gene have been localized: a 3' -proximal MAR, between nucleotides +43,186 and +43,850; a 5' -proximal MAR, between nucleotides -2,765 and -1,801; and a 5' -distal MAR, between nucleotides -5,262 and -4,048. Both the 3' -proximal and the 5' -distal MARS were present in cells that express the gene (HepG2 and CaCo-2 cells) as well as in cells that do not (HeLa cells), whereas the 5' -proximal MAR was detected only in HepG2 cells. These MARs were located at the bases of chromosomal loops in histone-extracted nuclei in all three cell lines. Various classes of A/T-rich sequences resembling the recognition site for topoisomerase II were present within the MAR-containing fragments. The boundaries of the DNase I-sensitive domain coincide with the positions of the 3' -proximal and 5' -distal matrix attachment sites. These results suggest the existence of a 47.5-kilobase domain that represents a topologically sequestered functional unit containing the coding region and all known cis-acting regulatory elements of the human apolipoprotein B gene.

Apolipoproteins B↗
PubMed1989

Tissue-specific undermethylation of DNA sequences at the 5' end of the human apolipoprotein B gene.

The methylation-sensitive restriction endonucleases HpaII and HhaI and the methylation-insensitive enzyme MspI were used to examine the methylation status of the 5' end of the human apolipoprotein B gene in cells in which the gene is transcriptionally active, such as HepG2 and CaCo-2 cells, and in HeLa cells, which do not express the gene. Several CCGG and GCGC sequences present in the region from -899 to +121 relative to the transcriptional start of the gene were undermethylated in HepG2 and CaCo-2 cells but methylated in HeLa cells. Because the region between -899 and +121 had previously been shown to exhibit tissue-specific promoter activity and to contain many DNaseI- and micrococcal nuclease-hypersensitive sites (Levy-Wilson, B., Fortier, C., Blackhart, B.D., and McCarthy, B.J. (1988) Mol. Cell. Biol. 8, 71-80), the current results suggest a correlation between undermethylation and nuclease sensitivity at the 5' end of the apolipoprotein B gene and expression of the gene.

Apolipoproteins B↗
PubMed1989

[Evaluation of the quality of 1986 census data by age and sex at the national level].

"The purpose of the present study is to compare the [Statistics Canada method of reverse record check] estimates of undercoverage, by age and sex, with estimates produced using other sources of data, specifically: final postcensal estimates; estimates produced by the component method (for cohorts since 1961); and estimates produced through use of administrative data from Family Allowance (ages 0-14) and Old Age Security (ages 65+). Results indicate that, even though the estimates of the level of undercoverage by age differ depending on the source and/or method, the same general trend is observed. Using the average of such figures, for example, can yield an estimate of the 'actual' size of the Canadian population as of June 1, 1986." (SUMMARY IN ENG AND SPA)

Age Factors↗
PubMed1988

DNase I- and micrococcal nuclease-hypersensitive sites in the human apolipoprotein B gene are tissue specific.

We have mapped the DNase I- and micrococcal nuclease-hypersensitive sites present in the 5' end of the human apolipoprotein B (apo-B) gene in nuclei from cells expressing or not expressing the gene. Four DNase I-hypersensitive sites were found in nuclei from liver-derived HepG2 cells and intestine-derived CaCo-2 cells, which express the apo-B gene, but not in HeLa cells, which do not. These sites are located near positions -120, -440, -700, and +760 base pairs relative to the transcriptional start site. Undifferentiated CaCo-2 cells exhibited another site, near position -540. Six micrococcal nuclease-hypersensitive sites were found in nuclei from HepG2 and CaCo-2 cells, but not in HeLa cells or free DNA. These sites are located near positions -120, -390, -530, -700, -850, and +210. HepG2 cells exhibited another site, near position +460. Comparison of the DNA sequence of the 5' flanking regions of the human and mouse apo-B genes revealed a high degree of evolutionary conservation of short stretches of sequences in the immediate vicinity of each of the DNase I- and most of the micrococcal nuclease-hypersensitive sites.

Apolipoproteins B↗
PubMed1988

[The impact on nuptiality of unbalanced sex distribution in the marriage market. Interpretation problems].

"The impact of sex disparities in numbers on the various sex specific ratios, traditionally used in nuptiality analysis, is not clear. Most authors consider that individuals pertaining to the sex group which is in minority on the marriage market, will tend to marry sooner and at [a] higher rate, and vice versa. There are however many counter-examples. Actually, a comparative analysis of the various results obtained so far is meaningless. There is indeed no agreement on the definition of the marriage market and the unbalance of sexes, nor on the way to measure it." The focus of the study is worldwide, with emphasis on data concerning Canada. (SUMMARY IN ENG AND SPA)

Americas↗
PubMed1988

[On the subject of l'école de Paris : Reference point for psychosomatic consultation.].

In his report, the author suggests that psychoanalysts working in hospitals must deal with the distinct nature of the psychoanalytic listening of somatic patients. The author defines the theoretic base for psychoanalytic listening as psychosomatics (as opposed to psychosomatic medicine). The author presents two models from which descend all the various psychoanalytic approaches of psychosomatic clinics. Emphasis is mostly placed on contributions made by the Ecole de Paris : the importance given to sensorimotor manifestations ; the evolutionist point of view ; the development of an original psychosomatic nosography, inspired by psychoanalysis ; and the somatization processes. The study covers a wide range of aspects, namely theoretical and clinical considerations of allergy as a structural phenomenon and as a way of relating to the world ; operational thinking in its proper historical context ; essential depression as a notion of great importance in psychosomatics. The author finally draws a profile of the various forms of psychoanalytic treatments offered to somatic patients.

English Abstract↗
PubMed1987

DNA sequence of the human apolipoprotein B gene.

The sequence of the human apolipoprotein B gene comprises 43 kb divided into 29 exons, one of which is unusually long and contains 7572 bp. Comparison of the gene sequence with four complete and three partial cDNA sequences published elsewhere reveals a total of 60 nucleotide substitutions and 39 amino acid substitutions and one small deletion in the signal peptide.

Amino Acid Sequence↗
PubMed1986

[Acute rheumatic fever in Martinique. Epidemiological, clinical and biological study].

An epidemiological and clinical survey of rheumatic fever was carried out in Martinique. The clinical manifestations, portal of entry and socio-economic facilitating factors appeared to be the same as those observed in metropolitan France when the disease occurred with a similar frequency. The prevalence and severity of rheumatic fever in Martinique are still high (in 1982, 49 new cases in a population of 300,000, including 12 with severe carditis), but they tend to diminish as the eradication campaign goes on. The reasons for the persistence of the disease and the problems encountered in the eradication campaign are discussed in the light of epidemiological data collected during the last 3 years.

Adolescent↗