Publications by authors named "Velard F"

Background: Cystic Fibrosis-related Bone Disease is an emerging challenge faced by 50 % of adult people with cystic fibrosis (CF). The multifactorial causes of this comorbidity remain elusive. However, congenital bone defects have been observed in animal models with CFTR mutations, suggesting its importance.

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Cutibacterium acnes is a commensal Gram-positive anaerobic bacterium that can also act as an opportunistic pathogen in various diseases, particularly in prosthetic joint infections (PJI). Throughout this review, we delve into the current understanding of the intricate interactions between C. acnes and host cells and discuss bacterial persistence in the host.

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Introduction: is a commensal skin bacterium that is involved in bone prosthesis infections (BPIs) and presents low-grade clinical symptoms. has been thought to escape the immune system at bone sites.

Material And Methods: Our study was carried out on a laboratory strain and two BPI-related clinical strains, one of which surprisingly induced clinical symptoms of inflammation in the patient.

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Background: The bacterial persistence, responsible for therapeutic failures, can arise from the biofilm formation, which possesses a high tolerance to antibiotics. This threat often occurs when a bone and joint infection is diagnosed after a prosthesis implantation. Understanding the biofilm mechanism is pivotal to enhance prosthesis joint infection (PJI) treatment and prevention.

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Infection and inflammation are two key features to consider to avoid septic or aseptic loosening of bone-implanted biomaterials. In this context, various approaches to fine-tune the biomaterial's properties have been studied in order to modulate the crosstalk between immune and skeletal cells. Cation-doping strategies for tuning of calcium phosphates properties has been evidenced as a promising way to control the biomaterial-induced inflammatory process, and thus improving their osteoimmunomodulatory properties.

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The sterilization of medical devices is paramount to achieve an acceptable level of sterility assurance and to prevent hospital-acquired infections. However, some medical devices cannot be sterilized by usual processes such as autoclave (AC) and gamma-ray irradiation (GI). A new non-thermal plasma (NTP) process using sealed bag that preserves the sterile state of the devices could be used as an alternative sterilization method.

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The major role and implication of bacterial biofilms in the case of bone and prosthesis infections have been highlighted and often linked to implant colonization. Management strategies of these difficult-to-treat infections consist in surgeries and antibiotic treatment, but the rate of relapse remains high, especially if , a high-virulent pathogen, is involved. Therapeutic approaches are not adapted to the specific features of biofilm in bone context whereas infectious environment is known to importantly influence biofilm structure.

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Infections, which interfere with bone regeneration, may be a critical issue to consider during the development of biomimetic material. Calcium phosphate (CaP) and type I collagen substrates, both suitable for bone-regeneration dedicated scaffolds, may favor bacterial adhesion. possesses adhesins that allow binding to CaP or collagen.

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Osteoblasts are bone-forming and highly active cells participating in bone homeostasis. In the case of osteomyelitis and more specifically prosthetic joint infections (PJI) for which () is mainly involved, the interaction between osteoblasts and results in impaired bone homeostasis. If, so far, most of the studies of osteoblasts and interactions were focused on osteoblast response following direct interactions with co-culture and/or internalization models, less is known about the effect of osteoblast factors on biofilm formation.

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In inflammatory diseases, polymorphonuclear neutrophils (PMNs) are known to produce elevated levels of pro-inflammatory cytokines and proteases. To limit ensuing exacerbated cell responses and tissue damage, novel therapeutic agents are sought. 4aa and 4ba, two pyridazinone-scaffold-based phosphodiesterase-IV inhibitors are compared in vitro to zardaverine for their ability to: (1) modulate production of pro-inflammatory mediators, reactive oxygen species (ROS), and phagocytosis; (2) modulate degranulation by PMNs after transepithelial lung migration.

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Article Synopsis
  • The study investigates the production of hemicellulolytic enzymes by the bacterium Thermobacillus xylanilyticus, which produces a key enzyme (Tx-xyn11) but suffers from variability in enzyme production among individual cells.
  • Experiments showed that after 23.5 generations of culturing on xylan, there was a significant decline (about 75%) in xylanase activity and gene expression, linked to shifts in cellular populations with differing growth characteristics.
  • Further investigations indicated that a specific subpopulation of bacterial cells, which did not sporulate, had lower enzyme activity and a longer lag phase, highlighting the importance of understanding cell diversity for improving enzyme production.
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Osteosarcoma is a rare primary bone cancer that mostly affects children and young adults. Current therapeutic approaches consist of combining surgery and chemotherapy but remain unfortunately insufficient to avoid relapse and metastases. Progress in terms of patient survival has remained the same for 30 years.

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species is an important threat for hospital healthcare because of frequent colonization of indwelling medical devices such as bone and joint prostheses through biofilm formations, leading to therapeutic failure. Furthermore, bacteria within biofilm are less sensitive to the host immune system responses and to potential antibiotic treatments. We suggested that the periprosthetic bone environment is stressful for bacteria, influencing biofilm development.

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Because of their long lifespan, matrix proteins of the vascular wall, such as elastin, are subjected to molecular aging characterized by non-enzymatic post-translational modifications, like carbamylation which results from the binding of cyanate (mainly derived from the dissociation of urea) to protein amino groups. While several studies have demonstrated a relationship between increased plasma concentrations of carbamylated proteins and the development of cardiovascular diseases, molecular mechanisms explaining the involvement of protein carbamylation in these pathological contexts remain to be fully elucidated. The aim of this work was to determine whether vascular elastic fibers could be carbamylated, and if so, what impact this phenomenon would have on the mechanical properties of the vascular wall.

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Cyclic nucleotide phosphodiesterase type 4 (PDE4), which controls the intracellular level of cyclic adenosine monophosphate (cAMP), has aroused scientific attention as a suitable target for anti-inflammatory therapy of respiratory diseases. This work describes the development and characterization of pyridazinone derivatives bearing an indole moiety as potential PDE4 inhibitors and their evaluation as anti-inflammatory agents. Among these derivatives, 4-(5-methoxy-1-indol-3-yl)-6-methylpyridazin-3(2)-one possesses promising activity, and selectivity towards PDE4B isoenzymes and is able to regulate potent pro-inflammatory cytokine and chemokine production by human primary macrophages.

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Cystic fibrosis (CF)-related bone disease has emerged as a significant comorbidity of CF and is characterized by decreased bone formation and increased bone resorption. Both osteoblast and osteoclast differentiations are impacted by cystic fibrosis transmembrane conductance regulator (CFTR) mutations. The defect of CFTR chloride channel or the loss of CFTRs ability to interact with other proteins affect several signaling pathways involved in stem cell differentiation and the commitment of these cells toward bone lineages.

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role is well described during acne but remains a mystery regarding its implication in bone and prosthesis or cerebrospinal fluid shunt infections. The main issue is that these low-grade symptom infections are difficult to diagnose and lead to irreversible and grave sequelae for patients. Consequently, there is an urgent need to find new biomarkers to accelerate the diagnosis of disease, an issue addressed by Beaver et al.

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Osteopenia and increased fracture rates are well-recognized in patients with cystic fibrosis (CF) disease. In CF pathology, F508del is the most common CFTR mutation, with more than 85% of patients carrying it on at least one allele. The underlying molecular defect in CFTR caused by the F508del-CFTR mutation in osteoclastogenesis, i.

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Chondrocyte apoptosis may have a pivotal role in the development of osteoarthritis. Interest has increased in the use of anti-apoptotic compounds to protect against osteoarthritis development. In this work, we investigated the effect of adrenomedullin (AM), a 52 amino-acid hormone peptide, and a 31 amino-acid truncated form, AM(22-52), on chondrocyte apoptosis.

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(1) Background: A suitable scaffold with adapted mechanical and biological properties for ligament tissue engineering is still missing. (2) Methods: Different scaffold configurations were characterized in terms of morphology and a mechanical response, and their interactions with two types of stem cells (Wharton's jelly mesenchymal stromal cells (WJ-MSCs) and bone marrow mesenchymal stromal cells (BM-MSCs)) were assessed. The scaffold configurations consisted of multilayer braids with various number of silk layers ( = 1, 2, 3), and a novel composite scaffold made of a layer of copoly(lactic acid--(e-caprolactone)) (PLCL) embedded between two layers of silk.

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, belonging to the Apicomplexa phylum, is a cosmopolitan protozoan parasite that affects at least 30% of the world's population. In West Africa, the leaves and bark of the tree species (DC.) Guill.

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Background: The lack of cystic fibrosis transmembrane conductance regulator (CFTR) function causes cystic fibrosis (CF), predisposing to severe lung disease, reduced growth and osteopenia. Both reduced bone content and strength are increasingly recognized in infants with CF before the onset of significant lung disease, suggesting a developmental origin and a possible role in bone disease pathogenesis. The role of CFTR in bone metabolism is unclear and studies on humans are not feasible.

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The purpose of this systematic review was to establish if patients suffering from periodontal diseases present differences in the expression or production of cationic antimicrobial peptides in saliva, gingival fluid, and periodontal tissues. Periodontal diseases are among the most common chronic diseases worldwide and share similar etiological or risk factors (genetic and/or environmental) with other systemic disorders. Over the last decade, an increasing number of publications have suggested the implication of antimicrobial peptides (AMPs) in periodontal and oral tissues conditions.

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Background: Carcinogenesis occurs in elastin-rich tissues and leads to local inflammation and elastolytic proteinase release. This contributes to bioactive matrix fragment (Matrikine) accumulation like elastin degradation products (EDP) stimulating tumour cell invasive and metastatic properties. We previously demonstrate that EDPs exert protumoural activities through Hsp90 secretion to stabilised extracellular proteinases.

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Prosthesis and joint infections are an important threat in public health, especially due to the development of bacterial biofilms and their high resistance to antimicrobials. Biofilm-associated infections increase mortality and morbidity rates as well as hospitalization costs. Prevention is the best strategy for this serious issue, so there is an urgent need to understand the signals that could induce irreversible bacterial adhesion on a prosthesis.

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