Publications by authors named "Marie-Catherine Tessier"
Background: Diabetic retinopathy (DR) affects about 25% of people with diabetes in Canada. Early detection of DR is essential for preventing vision loss.
Objective: We evaluated the real-world performance of an artificial intelligence (AI) system that analyzes fundus images for DR screening in a Quebec tertiary care center.
Most replicated genetic determinants for type 1 diabetes are common (minor allele frequency [MAF] >5%). We aimed to identify novel rare or low-frequency (MAF <5%) single nucleotide polymorphisms with large effects on risk of type 1 diabetes. We undertook deep imputation of genotyped data followed by genome-wide association testing and meta-analysis of 9,358 type 1 diabetes case and 15,705 control subjects from 12 European cohorts.
View Article and Find Full Text PDFAsthma, atopy, and related phenotypes are heterogeneous complex traits, with both genetic and environmental risk factors. Extensive research has been conducted and over hundred genes have been associated with asthma and atopy phenotypes, but many of these findings have failed to replicate in subsequent studies. To separate true associations from false positives, candidate genes need to be examined in large well-characterized samples, using standardized designs (genotyping, phenotyping and analysis).
View Article and Find Full Text PDFPathogenic Escherichia coli 4787 (O115:KV165) causes septicemia in pigs and expresses the fimbriae F165(1) encoded by the foo operon that belongs to the P fimbrial family. fooI and fooB, encoding specific foo regulators, are divergently transcribed; their intergenic region is responsible for the regulation of foo expression. The role of global and local supercoiling (transcription-induced supercoiling within the intergenic region) on the regulation of foo expression was investigated.
View Article and Find Full Text PDFArticle Synopsis
- TAP2 plays a crucial role in transporting antigenic peptides to HLA molecules and has been linked to type 1 diabetes, although the relationship might also involve genes from the HLA DR and DQ regions.
- In humans, different splicing isoforms of TAP2 influence peptide selectivity rather than nonsynonymous single-nucleotide polymorphisms (nsSNPs), which are shown to have affected the rat version of the protein.
- The study finds that specific genetic variants of TAP2, independent of HLA DR-DQ, are associated with type 1 diabetes, suggesting that these variants favor different isoform splicing, which in turn affects peptide selection.
Article Synopsis
- A study linked type 1 diabetes to a specific genetic variant (+6230G>A), but also explored other genetic factors at the 5' end of the CTLA-4 gene to determine their potential contribution.
- Researchers conducted tests on family trios and found that both the +6230G>A variant (G allele) and a polymorphism at the promoter (-319C>T variant) contributed to susceptibility, with significant overtransmission of the C allele from parents.
- Functional studies indicated that the -319C>T variant leads to increased gene expression in immune cells, suggesting it may play an independent role alongside +6230G>A in type 1 diabetes risk.
Article Synopsis
- F165(1) (foo) and CS31A (clp) are bacterial adhesins produced by E. coli strains linked to diarrhea and septicemia in young livestock, regulated by phase variation mechanisms.
- Lrp protein activates transcription of foo and fooI while repressing clp, causing different phase variation patterns: most cells express foo (phase-ON) while clp is mainly phase-OFF.
- Environmental factors like temperature, glucose, and amino acids influence the expression and phase variation of foo and clp, indicating that these adhesins thrive in low-nutrient conditions.
A common T17A polymorphism in the signal peptide of the cytotoxic T-lymphocyte antigen 4 (CTLA-4), a T-cell receptor that negatively regulates immune responses, is associated with risk for autoimmune disease. Because the polymorphism is absent from the mature protein, we hypothesized that its biological effect must involve early stages of protein processing, prior to signal peptide cleavage. Constructs representing the two alleles were compared by in vitro translation, in the presence of endoplasmic reticulum membranes.
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