Biomedical subjects

Christian Couture

Publications and source records attributed to Christian Couture.

9 recordsLinked to original sources

PubMed2026

Genome-wide association meta-analysis of eating behavior traits revealed one susceptibility locus for emotional eating.

In order to identify new and genome-wide significant loci for eating behavior traits (cognitive restraint, uncontrolled eating and emotional eating), we conducted a meta-GWAS with seven studies of European ancestry (n = 11,250). Eating behavior was assessed using the Three-Factor Eating Questionnaire. Genotype effects of single studies were estimated using additive models adjusting for age, sex, BMI, and principal components and single study results were combined by fixed-effect meta-analysis.For cognitive restraint and uncontrolled eating, no genome-wide significant association could be detected. For emotional eating, one genomic region on chromosome 5 comprising two polymorphisms attained genome-wide significance (P = 4.0×10-8 for rs6877636 and P = 3.2×10-8 for rs6897090). The minor alleles were associated with higher emotional eating scores (β=0.093 ± 0.017), with a similar direction of effect in each study. Both SNPs, in near perfect linkage disequilibrium, mapped to RP11-24P24.1, a processed pseudogene of ornithine decarboxylase 1 (ODC1). Enrichment analysis revealed a significant overlap between genome-wide BMI-associated variants and nominal emotional eating variants, supporting the hypothesis that shared genetic factors may influence both eating behavior traits and obesity risk. Finally, we observed a number of interesting associations reaching suggestive significance (P < 10-6) involving BMI candidate genes, including a suggestive association between FTO variants and cognitive restraint (rs9922708, β = 0.069, P = 5.9×10-7).In conclusion, our meta-GWAS identified for the first time a robust chromosomal region associated with emotional eating in seven studies. Given that emotional eating strongly influences body weight but is often stigmatized, recognizing genetic susceptibility to certain eating behaviors may help reduce stigma and alleviate guilt.

Journal Article↗

PubMed2025

Polygenic prediction of body mass index and obesity through the life course and across ancestries.

Polygenic scores (PGSs) for body mass index (BMI) may guide early prevention and targeted treatment of obesity. Using genetic data from up to 5.1 million people (4.6% African ancestry, 14.4% American ancestry, 8.4% East Asian ancestry, 71.1% European ancestry and 1.5% South Asian ancestry) from the GIANT consortium and 23andMe, Inc., we developed ancestry-specific and multi-ancestry PGSs. The multi-ancestry score explained 17.6% of BMI variation among UK Biobank participants of European ancestry. For other populations, this ranged from 16% in East Asian-Americans to 2.2% in rural Ugandans. In the ALSPAC study, children with higher PGSs showed accelerated BMI gain from age 2.5 years to adolescence, with earlier adiposity rebound. Adding the PGS to predictors available at birth nearly doubled explained variance for BMI from age 5 onward (for example, from 11% to 21% at age 8). Up to age 5, adding the PGS to early-life BMI improved prediction of BMI at age 18 (for example, from 22% to 35% at age 5). Higher PGSs were associated with greater adult weight gain. In intensive lifestyle intervention trials, individuals with higher PGSs lost modestly more weight in the first year (0.55 kg per s.d.) but were more likely to regain it. Overall, these data show that PGSs have the potential to improve obesity prediction, particularly when implemented early in life.

Adolescent↗

PubMed2006

Myocardial dysfunction in polymyositis.

Myocardial involvement in polymyositis is occasionally suspected, but symptomatic cardiac dysfunction is rarely reported. Described in the present report is a 48-year-old woman with a two-year history of polymyositis who suddenly developed near fatal ventricular arrhythmia, and a 56-year-old man with a relapsing polymyositis who developed severe systolic dysfunction. These two cases emphasize the importance of systematic cardiac evaluation when the diagnosis of polymyositis is initially made and the necessity of re-evaluating cardiac function, even in the presence of clinical remission and normalization of creatine phosphokinase with treatment.

Cardiomyopathies↗

PubMed2004

Chyloptysis in adults: presentation, recognition, and differential diagnosis.

Chyloptysis is a rare finding, and the accompanying respiratory symptoms are usually nonspecific. The recognition of the chylous nature of the sputum is requisite for proper diagnosis, especially if chyloptysis is not accompanied by chylous pleural effusion. The key to the differential diagnosis of chyloptysis is to consider illnesses that can induce reflux of chyle into the bronchial tree. There are two mechanisms postulated: the first requires the presence of an abnormal communication between the bronchial tree and the lymphatic channels, and the second requires a bronchopleural fistula in the context of a chylous pleural effusion. Chyloptysis in adults should prompt assessment for evidence of lymphatic obstruction from trauma, radiation, and malignancy, and to exclude diseases with known association with chyloptysis, ie, lymphangioleiomyomatosis, yellow nail syndrome, or thoracic lymphangiectasis. A lymphangiogram is recommended to define the abnormality. In the case of lymphangiectasis, patients respond to either dietary modification and/or ligation of the thoracic duct.

Adult↗

PubMed2003

Histopathology of bronchiolar disorders.

Bronchiolar pathologic lesions result from the interplay between inflammatory and mesenchymal cells following injury to bronchioles. Offending agents include viruses, bacteria, fungi, cigarette smoke, toxic inhalants, inorganic dusts, allergens, and systemic or localized autoimmune or inflammatory processes. Bronchiolar pathologic lesions also arise in the context of allograft transplantation and pathology of the large airways and in the setting of an idiopathic disorder. Given the great variety of sources of injury and diversity of clinical, radiological, and functional patterns that result, it is no surprise that most morphological abnormalities of the bronchioles are not specific. They thus represent a diagnostic challenge to the surgical pathologist, and the necessity of a multidisciplinary (clinical/radiological/pathologic) approach cannot be overemphasized. After a survey of the normal histology of bronchioles, we present a pragmatic classification that reflects the spectrum of bronchiolar pathology, illustrating the intimate interdependence of clinical, radiological, and pathologic findings in assessing the significance of bronchiolar lesions. This classification is intended to be applicable to surgical pathology material that can be correlated with clinical disease syndromes. It includes asthma-associated bronchiolar changes, chronic bronchitis/emphysema-associated bronchiolar changes, cellular bronchiolitis, respiratory bronchiolitis, bronchiolitis obliterans with intraluminal polyps/ BOOP, constrictive bronchiolitis, mineral dust small airway disease, peribronchiolar fibrosis and bronchiolar metaplasia, and bronchiolocentric nodules.

Journal Article↗

PubMed2003

Human intestinal anisakiosis due to consumption of raw salmon.

Anisakiosis is a parasitic infection that follows consumption of raw or insufficiently pickled, salted, smoked, or cooked wild marine fish infected with Anisakis sp. larvae. We report a case of intestinal anisakiosis in a 50-year-old man from Quebec who presented with abdominal pain and peripheral eosinophilia after eating raw wild-caught salmon from the Pacific Ocean off Canada. Abdominal CT scan showed bowel distension proximal to a segmental jejunal wall thickening, which was resected. The jejunum segment showed a localized area of serositis with mucosal edema and a submucosal abscess rich in eosinophils surrounding a parasite consistent with the third larval stage of Anisakis sp. Diagnostic morphologic characteristics included an unpaired excretory gland (renette cell), Y-shaped lateral epidermal cords, no apparent reproductive system, and a ventriculus (glandular esophagus). These features and the absence of lateral alae excluded Ascaris sp. The absence of ventricular appendage and intestinal cecum excluded other anisakids of the genera Pseudoterranova and Contracaecum. As the popularity of eating raw fish is growing in North America, anisakiosis may be diagnosed more frequently in surgical specimens. This parasitic infection should be considered in the differential diagnosis of acute abdominal syndromes and eosinophilic infiltrates of the stomach, small intestine, colon, omentum, and mesentery, especially with a history of raw marine fish consumption.

Animals↗

PubMed2003

[Unusual parosteal osteochondromatous proliferation or Nora's tumor. A clinicopathological analysis of 4 cases].

Nora's lesion, also known as bizarre parosteal osteochondromatous proliferation (B.P.O.P.), involves mostly the small tubular bones of the hands and feet. Histologically, it is characterized by a proliferation of chondroid, bony and fibrous tissues, sometimes with high cellular density, bizarre chondrocytes but is devoid of cellular atypia and necrosis. Distinct blue color is noted at the interface of bone and cartilage. The most important lesions that present differential diagnostic problems are chondrosarcoma, parosteal osteosarcoma and florid reactive periostitis. The lesion is benign but may recur locally in as many as 55%. The clinical and pathological findings of four cases of Nora's lesion are presented.

Adolescent↗

PubMed2002

Effect of treatment delay on outcome of patients with early-stage head-and-neck carcinoma receiving radical radiotherapy.

PURPOSE: Access to radiotherapy (RT) has been considerably reduced in Quebec since the late 1980s. The aim of the present study was to analyze the impact of delaying treatment on the outcome of patients with early head-and-neck squamous cell carcinomas. MATERIALS AND METHODS: This retrospective analysis examined the outcome for all 623 patients with early-stage disease (T1-2, N0-1) who received radical RT between 1988 and 1997 at the Hotel Dieu of Quebec Hospital. Delay was defined as the time from initial evaluation by a radiation oncologist to the beginning of RT. Delay intervals were divided as follows: <30 days, 31-40 days, and >40 days. RESULTS: A delay of >40 days was significantly associated with an increased risk of local and neck failure and poorer survival relative to patients treated in <30 days or between 31 and 40 days. The adjusted hazard ratio and (in parentheses) the 95% confidence interval was 2.6 (1.07-6.4), 2.73 (1.38-5.4), and 1.7 (1.1-2.6), respectively, for local failure, neck failure, and survival. In the subgroup of patients with T2N0 disease, delaying RT for >30 days was associated with a poor outcome, as measured by the same end points. CONCLUSION: Delaying RT had a deleterious effect on these patients. RT should be started as soon as possible in patients with squamous cell carcinoma of the head and neck, preferably within 20-30 days after evaluation by a radiation oncologist.

Aged↗

PubMed2002

p53 and Ki-67 as markers of radioresistance in head and neck carcinoma.

BACKGROUND: p53 and Ki-67 are regarded as potential interesting predictors of radioresistance, although their exact influence awaits confirmation on a large cohort of uniformly treated patients. METHODS: In a retrospective cohort of 304 patients with squamous cell carcinoma of the head and neck who were treated with radical radiotherapy, the expression levels of p53 and Ki-67 were assessed by immunohistochemistry. Local control and survival curves were generated for p53 and Ki-67 using the Kaplan-Meier method. The difference between curves was calculated in univariate and multivariate analyses. RESULTS: The overexpression of p53 was associated with local treatment failure (P = 0.01) but not with survival (P = 0.09). In a Cox analysis, p53 overexpression remained an independent predictor of local failure, with a relative risk of local failure of 1.5 (P = 0.05). Low proliferation (Ki-67 < 20%) was a significant factor in local failure for patients with tumors of the oral cavity only (P = 0.01). Patients with both unfavorable immunohistochemical markers (p53 overexpression and low proliferation) had a 45% rate of local control compared with a 67% rate for all other combinations (P = 0.002). This association was even more significant in patients with T1-T2 lesions (45% vs. 77%; P = 0.0002). CONCLUSIONS: The results support the role of p53 as an independent predictor of local failure in patients with squamous cell carcinoma of the head and neck who are treated by radical radiotherapy, suggesting that it may predict radioresistance. Combined with p53, Ki-67 may help in the better selection of patients for radiotherapy, especially for patients with early-stage tumors. Prospective studies are now needed to confirm these results and to define better the role of these markers in the management of patients with head and neck carcinoma.

Adult↗