358 results match your criteria: "Centre LOEX de l'Université Laval[Affiliation]"

Introduction: Recent findings show that visible light, particularly blue light, stimulates melanogenesis in human skin, though the underlying mechanisms remain debated. This study aimed to determine the cell damage threshold of non-ionizing blue light on keratinocytes while preserving their ability to stimulate melanogenesis.

Methods: Human keratinocytes (N = 3) and melanocytes (N = 3) were isolated from skin samples of varying Fitzpatrick skin phototypes and irradiated with blue light (λpeak = 457 nm) and UVA light (λpeak = 385 nm).

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Over the last decades, the human species has seen an increase in the incidence of pathologies linked to the genitourinary tract. Observations in animals have allowed us to link these increases, at least in part, to changes in the environment and, in particular, to an increasing presence of endocrine disruptors. These can be physical agents, such as light or heat; natural products, such as phytoestrogens; or chemicals produced by humans.

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Article Synopsis
  • Uropathogenic bacteria are the primary cause of urinary tract infections (UTIs), which affect over 50% of women and can recur in up to 30% of patients, causing increased social and economic burdens.
  • Current treatments for recurrent UTIs are ineffective, prompting the need for better research models.
  • A new human-derived 3D bladder mucosa model was developed using tissue engineering, allowing researchers to study the stages of UTIs, including bacterial adhesion and re-emergence, using specific strains of bacteria for infection.
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Generation of a control induced pluripotent stem cell line (CBRCULi014-A) derived from the lymphoblastoid cells of a pediatric individual.

Stem Cell Res

December 2024

CERVO Brain Research Centre, Institut Universitaire en Santé Mentale de Québec, Quebec City, QC G1J 2G3, Canada; Department of Medicine, Faculty of Medicine, Université Laval, Quebec City, QC G1V 06A, Canada. Electronic address:

Lymphoblastoid cell lines serve as a readily and continuous resource for generating induced pluripotent stem cells (iPSCs), enabling the modeling of various genetic disorders in vitro. When investigating congenital and infantile diseases, age-matched controls derived from pediatric individuals are typically necessary, yet they may be scarce or difficult to obtain. Here, the Sendai virus system was employed to introduce reprogramming factors into lymphoblastoid cells derived from an apparently healthy 4-year-old female.

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Epigenetic memory of radiotherapy in dermal fibroblasts impairs wound repair capacity in cancer survivors.

Nat Commun

October 2024

Dermatology and Venereology Division, Department of Medicine Solna, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.

Radiotherapy (RT), a common cancer treatment, unintentionally harms surrounding tissues, including the skin, and hinders wound healing years after treatment. This study aims to understand the mechanisms behind these late-onset adverse effects. We compare skin biopsies from previously irradiated (RT) and non-irradiated (RT) sites in breast cancer survivors who underwent RT years ago.

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Differential Nitric Oxide Responses in Primary Cultured Keratinocytes and Fibroblasts to Visible and Near-Infrared Light.

Antioxidants (Basel)

September 2024

Centre de Recherche en Organogénèse Expérimentale de l'Université Laval/LOEX, Université Laval, Quebec City, QC G1V 0A6, Canada.

NO is a crucial signaling molecule involved in skin health, the immune response, and the protection against environmental stressors. This study explores how different wavelengths of light, namely blue (455 nm), red (660 nm), and near infrared (NIR, 850 nm), affect nitric oxide (NO) production in skin cells. Primary keratinocytes and fibroblasts from three donors were exposed to these wavelengths, and NO production was quantified using a DAF-FM fluorescent probe.

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Calcium handling abnormalities increase arrhythmia susceptibility in DMSXL myotonic dystrophy type 1 mice.

Biomed Pharmacother

November 2024

Cardiovascular Research Program, VA New York Harbor Healthcare System, New York, NY, USA; Department of Medicine, Cell Biology and Pharmacology, State University of New York Downstate Health Sciences University, New York, NY, USA; Department of Medicine, NYU Langone School of Medicine, New York, NY, USA. Electronic address:

Background: Myotonic dystrophy type 1 (DM1) is a multiorgan disorder with significant cardiac involvement. ECG abnormalities, including arrhythmias, occur in 80 % of DM1 patients and are the second-most common cause of death after respiratory complications; however, the mechanisms underlying the arrhythmogenesis remain unclear. The objective of this study was to investigate the basis of the electrophysiological abnormalities in DM1 using the DMSXL mouse model.

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Choroidal melanocyte secretome from cultured cells and tissue-engineered choroid models exposed to acute or chronic oxidative stress.

Exp Eye Res

December 2024

Centre de recherche du Centre Hospitalier Universitaire (CHU) de Québec-Université Laval, Axe Médecine Régénératrice, Hôpital du Saint-Sacrement, Québec, Canada; Centre de recherche en Organogénèse Expérimentale de l'Université Laval/LOEX, Québec, Canada; Département d'Ophtalmologie et d'oto-rhino-laryngologie-chirurgie cervico-faciale, Faculté de Médecine, Université Laval, Québec, Canada. Electronic address:

The choroid, located between the retina and the sclera, is a vascularized and pigmented connective tissue, playing a crucial role in providing oxygen and nutrients to the outer layers of the retina, and in absorbing excessive light. How choroidal melanocytes (CMs) participate in tissue homeostasis through paracrine signaling with neighboring cells is poorly understood. In this study, using two-dimensional and three-dimensional models, we aimed to identify proteins secreted by CMs under different oxidative stress conditions.

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Background: The aim was to estimate direct medical costs of men and women patients by age group related to cardiovascular diseases (coronary heart disease, strokes) in the province of Quebec, Canada from the economic perspective of the healthcare public system, encompassing five cost components: physician fees, hospitalization (hospital stay, intensive care stay), emergency visits and medication costs.

Methods: This matched case-control study involved secondary data from a longitudinal cohort study (1997-2018) of 4584 white-collar workers. Participants were followed for a four-year period.

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The Coronavirus Disease 2019 (COVID-19), caused by virus SARS-CoV-2, is characterized by massive inflammation and immune system imbalance. Despite the implementation of vaccination protocols, the accessibility of treatment remains uneven. Furthermore, the persistent threat of new variants underscores the urgent need for expanded research into therapeutic options for SARS-CoV-2.

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The corneal endothelium is responsible for pumping fluid out of the stroma in order to maintain corneal transparency, which depends in part on the expression and activity of sodium-potassium pumps. In this study, we evaluated how physiologic pressure and flow influence transcription, protein expression, and activity of Na+/K+-ATPase. Native and engineered corneal endothelia were cultured in a bioreactor in the presence of pressure and flow (hydrodynamic culture condition) or in a Petri dish (static culture condition).

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Adaptation of a standardized self-reported cost questionnaire specific for the severe burn injury population (BI-CoPaQ).

Burns

December 2024

Department of Social and Preventive Medicine, Faculty of Medicine, Université Laval, 1050 Avenue de la Médecine, Université Laval, Québec, QC G1V 0A6, Canada; Centre de Recherche du CHU de Québec-Université Laval, Hôpital du Saint-Sacrement, 1050, Chemin Ste-Foy, Québec, QC G1S 4L8, Canada; Centre de recherche en organogénèse expérimentale de l'Université Laval/LOEX, 1401 18e Rue, Québec, QC G1J 1Z4, Canada. Electronic address:

Severe burn injuries (SBIs) are known to pose a significant burden on patients, caregivers, and the healthcare system. Yet, scarce data on the short and long-term clinical and economic impacts of these injuries limit the development of evidence-informed strategies and policies to better care for these patients. To fill in this gap, we adapted a previously validated self-reported out-of-pocket cost measurement questionnaire, the Cost for Patients Questionnaire (CoPaQ), to the severe burn injury survivor context.

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During embryogenesis, cells arrange into precise patterns that enable tissues and organs to develop specialized functions. Despite its critical importance, the molecular choreography behind these collective cellular behaviors remains elusive, posing a major challenge in developmental biology and limiting advances in regenerative medicine. By using the mouse hair follicle as a mini-organ system to study the formation of bud-like structures during embryonic development, our work uncovers a crucial role for the Rho GTPase regulator ARHGEF3 in hair follicle morphogenesis.

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Hypertrophic scarring is a common complication in severely burned patients who undergo autologous skin grafting. Meshed skin grafts tend to contract during wound healing, increasing the risk of pathological scarring. Although various technologies have been used to study cellular contraction, current methods for measuring contractile forces at the tissue level are limited and do not replicate the complexity of native tissues.

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Synergistic Toxicity of Pollutant and Ultraviolet Exposure from a Mitochondrial Perspective.

Int J Mol Sci

August 2024

Centre de Recherche du CHU de Québec, Université Laval, Axe Médecine Régénératrice, Hôpital du Saint-Sacrement, Québec, QC G1S 4L8, Canada.

Ultraviolet (UV) exposure and atmospheric pollution are both independently implicated in skin diseases such as cancer and premature aging. UVA wavelengths, which penetrate in the deep layers of the skin dermis, exert their toxicity mainly through chromophore photosensitization reactions. Benzo[a]pyrene (BaP), the most abundant polycyclic aromatic hydrocarbon originating from the incomplete combustion of organic matter, could act as a chromophore and absorb UVA.

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Background: The upper respiratory mucosa plays a crucial role in both the physical integrity and immunological function of the respiratory tract. However, in certain situations such as infections, trauma, or surgery, it might sustain damage. Tissue engineering, a field of regenerative medicine, has found applications in various medical fields including but not limited to plastic surgery, ophthalmology, and urology.

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History-restricted marginal structural model and latent class growth analysis of treatment trajectories for a time-dependent outcome.

Int J Biostat

November 2024

Département de médecine sociale et préventive, Université Laval, Centre de recherche du CHU de Québec - Université Laval, Axe santé des populations et pratiques optimales en santé, Québec, QC, Canada.

Article Synopsis
  • Researchers introduced a new method combining latent class growth analysis (LCGA) with nonparametric history-restricted marginal structural models (HRMSM) to address limitations of the previous LCGA-MSM framework for time-dependent outcomes.
  • The study is the first to apply HRMSMs to time-to-event data while proposing a new causal parameter to resolve interpretation issues typically seen in survival analysis.
  • Simulation results showed that both g-computation and pooled longitudinal targeted maximum likelihood estimation (LTMLE) yielded unbiased estimates, while also revealing that higher statin adherence in older Quebecers correlated with reduced risks of cardiovascular disease and all-cause mortality.
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The immunogenicity of allogeneic skin fibroblasts in transplantation has been controversial. Whether this controversy comes from a natural heterogeneity among fibroblast subsets or species-specific differences between human and mouse remains to be addressed. In this study, we sought to investigate whether fibroblasts derived from either adult or neonatal human skin tissues could induce different immune responses toward phagocytosis and T cell activation using in vitro co-culture models.

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Tension directs cancer cell migration over fiber alignment through energy minimization.

Biomaterials

December 2024

Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, 37235, USA. Electronic address:

Cell migration during many fundamental biological processes including metastasis requires cells to traverse tissue with heterogeneous mechanical cues that direct migration as well as determine force and energy requirements for motility. However, the influence of discrete structural and mechanical cues on migration remains challenging to determine as they are often coupled. Here, we decouple the pro-invasive cues of collagen fiber alignment and tension to study their individual impact on migration.

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Microvesicles (MVs) are a subtype of extracellular vesicles that can transfer biological information from their producer cells to target cells. This communication can in turn affect both normal and pathological processes. Mounting evidence has revealed that dermal wound myofibroblasts (Wmyo) produce MVs, which can transfer biomolecules impacting receptor cells such as human dermal microvascular endothelial cells (HDMECs).

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Microvesicles (MVs) are a subtype of extracellular vesicles that can transfer biological information over long distances, affecting normal and pathological processes including skin wound healing. However, the diffusion of MVs into tissues can be impeded by the extracellular matrix (ECM). We investigated the diffusion of dermal wound myofibroblast-derived MVs into the ECM by using hydrogels composed of different ECM molecules such as fibrin, type III collagen and type I collagen that are present during the healing process.

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Recent Advances in Molecular and Genetic Research on Uveal Melanoma.

Cells

June 2024

Department of Ophthalmology and Otorhinolaryngology-Cervico-Facial Surgery, Faculty of Medicine, Université Laval, Quebec City, QC G1V 0A6, Canada.

Uveal melanoma (UM), a distinct subtype of melanoma, presents unique challenges in its clinical management due to its complex molecular landscape and tendency for liver metastasis. This review highlights recent advancements in understanding the molecular pathogenesis, genetic alterations, and immune microenvironment of UM, with a focus on pivotal genes, such as /, , and , and delves into the distinctive genetic and chromosomal classifications of UM, emphasizing the role of mutations and chromosomal rearrangements in disease progression and metastatic risk. Novel diagnostic biomarkers, including circulating tumor cells, DNA and extracellular vesicles, are discussed, offering potential non-invasive approaches for early detection and monitoring.

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Antiproliferative and Anti-Inflammatory Effects of the Polyphenols Phloretin and Balsacone C in a Coculture of T Cells and Psoriatic Keratinocytes.

Int J Mol Sci

May 2024

Centre de Recherche en Organogénèse Expérimentale de l'Université Laval/LOEX, Axe Médecine Régénératrice, Centre de Recherche du CHU de Québec-Université Laval, 1401 18e Rue, Quebec City, QC G1J 2Z4, Canada.

Plaque psoriasis is a chronic inflammatory skin disease causing red inflamed lesions covered by scales. Leukocytes, including dendritic cells and T cells, participate in the inflammation of the skin by producing multiple cytokines, thus contributing to the hyperproliferation of keratinocytes. Lack of effectiveness and toxic side effects are the main concerns with conventional treatments, and research involving new antipsoriatic molecules is essential.

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