Using a Virtual Reality Tool to Provide Primary Prevention Training in the Construction Field Following a Periodic Medical Visit: Cross-Sectional Study.

BACKGROUND: The construction field is highly concerned with the risk of work-related accidents, and training employees is difficult due to their small numbers in most companies. OBJECTIVE: This study aimed to study the impact of a virtual reality (VR) training tool following a periodic occupational health medical visit on the feeling of personal effectiveness in preventing occupational risks related to co-activity on a construction site. METHODS: We conducted a cross-sectional study with employees who had a periodic medical visit between April 1, 2022, and October 13, 2022, in a French occupational health service specializing in the construction field (Services Médicaux Interentreprises Bâtiment Travaux Publics [SMIBTP]). The employees were divided into 2 groups according to the training received: a medical visit alone or coupled with a session with a VR tool. We compared the scores for a "feeling of self-efficacy in occupational risk prevention" using the Fisher exact test. RESULTS: Of the 588 employees included, 210 had a medical visit alone, and 378 had a medical visit coupled with VR training. Training with the VR tool was associated with an increased "feeling of self-efficacy in occupational risk prevention." The employees who benefited from the training reported a willingness to apply the advice given on prevention to a greater extent than those who did not, and they believed that risks on the worksite could be reduced using this tool. CONCLUSIONS: Using VR training as a complement to periodic medical visits in an occupational health service improves the feeling of personal effectiveness in occupational risk prevention at the end of the training. If this trend is confirmed over a longer period of time, it could be an easily accessible prevention lever for employees in the future.

[End of career and end of exposure visits]. / Visites de fin de carrière et de fin d'exposition.

END-OF-CAREER AND END-OF-EXPOSURE VISITS Many legislative changes have been introduced in recent months concerning the activity of occupational physicians. Particular emphasis has been placed on the traceability of exposure and the resulting medical follow-up with the creation of end-of-career and end-of-exposure visits. These new features imply changes in terms of post-occupational monitoring in particular, but other appointments are obviously possible for workers in conjunction with their prevention and occupational health service.

VISITES DE FIN DE CARRIÈRE ET DE FIN D'EXPOSITION De nombreux changements législatifs ont eu lieu ces derniers mois concernant l'action des médecins du travail. Un accent particulier a été mis sur la traçabilité des expositions et la surveillance médicale qui en découle avec la création des visites de fin de carrière et de fin d'exposition. Ces nouveautés impliquent des modifications en matière de surveillance post-professionnelle notamment ; d'autres rendez-vous restent évidemment possibles pour les travailleurs, en lien avec leur service de prévention et de santé au travail.

Diamidines versus Monoamidines as Anti-Pneumocystis Agents: An in Vivo Study.

Some compounds articulated around a piperazine or an ethylenediamine linker have been evaluated in vitro to determine their activity in the presence of a 3T6 fibroblast cell line and an axenic culture of Pneumocystis carinii, respectively. The most efficient antifungal derivatives, namely N,N'-bis(benzamidine-4-yl)ethane-1,2-diamine (compound 6, a diamidine) and N-(benzamidine-4-yl)-N'-phenylethane-1,2-diamine (compound 7, a monoamidine), exhibited no cytotoxicity and were evaluated in vivo in a rat model. Only the diamidine 6 emerged as a promising hit for further studies.

Design and evaluation of a 6-mer amyloid-beta protein derived phage display library for molecular targeting of amyloid plaques in Alzheimer's disease: Comparison with two cyclic heptapeptides derived from a randomized phage display library.

Amyloid plaques are the main molecular hallmark of Alzheimer's disease. Specific carriers are needed for molecular imaging and for specific drug delivery. In order to identify new low molecular weight amyloid plaque-specific ligands, the phage display technology was used to design short peptides that bind specifically to amyloid-beta protein, which is the principal component of amyloid plaques. For this purpose, a phage display library was designed from the amino acid sequence of amyloid-beta 1-42. Then, the diversity was increased by soft oligonucleotide-directed mutagenesis. This library was screened against amyloid-beta 1-42 and several phage clones were isolated. Their genomes were sequenced to identify the displayed peptides and their dissociation constants for amyloid-beta 1-42 binding were evaluated by ELISA. The two best peptides, which are derived from the C-terminus hydrophobic domain of amyloid-beta 1-42 that forms a beta-strand in amyloid fibers, were synthesized and biotinylated. After confirming their binding affinity for amyloid-beta 1-42 by ELISA, the specific interaction with amyloid plaques was validated by immunohistochemistry on brain sections harvested from a mouse model of Alzheimer's disease. The thioflavin T aggregation assay has furthermore shown that our peptides are able to inhibit the amyloid fiber formation. They are not toxic for neurons, and some of them are able to cross the blood-brain barrier after grafting to a magnetic resonance imaging contrast agent. To conclude, these peptides have high potential for molecular targeting of amyloid plaques, either as carriers of molecular imaging and therapeutic compounds or as amyloid fiber disrupting agents.

In vitro biomedical applications of functionalized iron oxide nanoparticles, including those not related to magnetic properties.

Superparamagnetic iron oxide nanoparticles (SPION) are very promising contrast media, especially for molecular imaging, due to their superior NMR efficacy. They even have wider biomedical applications such as in drug and gene delivery, tissue engineering and bioseparation, or as sensitive biological nanosensors. By coupling them to affinity ligands, SPION can bind to drugs, proteins, enzymes, antibodies or nucleotides. For in vitro biomedical applications, the detection of molecular interaction is possible by using a diversity of systems capable of sensing the magnetic properties of these materials. The goal of the present work was to develop and validate various in vitro biomedical applications of ultrasmall superparamagnetic particles of iron oxide (USPIO), including some that are not related to their magnetic properties. USPIO coated with dextran, starch or bisphosphonate exposing carboxylate groups were synthesized and some of them were functionalized by conjugating various biomolecules, such as biotin, streptavidin and apoptosis, or VCAM-1 specific peptides. The in vitro biomedical applications assessed in the present work included: (1) the relaxometric measurement of antibody concentration, cell receptor expression, molecular interaction, and enzymatic activity in aqueous suspensions; (2) MRI visualization of cells and detection of molecular interaction in an ELISA system; (3) ELISA applications of USPIO derivatives; and (4) detection of specific biomolecules by histochemistry. Our results confirm that rapid and simple in vitro detection of a diversity of functionalized SPION with relevance in medicine is possible by the existing NMR techniques and by chemical staining reactions. The protocols can be applied to minimally prepared biological samples (e.g. whole blood, blood plasma or serum, cell suspensions, biopsies, histological preparations, etc.), and often do not need complicated systems of signal amplification. The use of SPION labeled compounds could furthermore contribute to cost reductions in the diagnosis and in patient care.

How to quantify iron in an aqueous or biological matrix: a technical note.

Iron oxide (nano)particles are powerful contrast agents for MRI and tags for magnetic cellular labeling. The need for quantitative methods to evaluate the iron content of contrast media solutions and biological matrixes is thus obvious. Several convenient methods aiming at the quantification of iron from iron oxide nanoparticle-containing samples are presented.

DUX4c is up-regulated in FSHD. It induces the MYF5 protein and human myoblast proliferation.

Facioscapulohumeral muscular dystrophy (FSHD) is a dominant disease linked to contractions of the D4Z4 repeat array in 4q35. We have previously identified a double homeobox gene (DUX4) within each D4Z4 unit that encodes a transcription factor expressed in FSHD but not control myoblasts. DUX4 and its target genes contribute to the global dysregulation of gene expression observed in FSHD. We have now characterized the homologous DUX4c gene mapped 42 kb centromeric of the D4Z4 repeat array. It encodes a 47-kDa protein with a double homeodomain identical to DUX4 but divergent in the carboxyl-terminal region. DUX4c was detected in primary myoblast extracts by Western blot with a specific antiserum, and was induced upon differentiation. The protein was increased about 2-fold in FSHD versus control myotubes but reached 2-10-fold induction in FSHD muscle biopsies. We have shown by Western blot and by a DNA-binding assay that DUX4c over-expression induced the MYF5 myogenic regulator and its DNA-binding activity. DUX4c might stabilize the MYF5 protein as we detected their interaction by co-immunoprecipitation. In keeping with the known role of Myf5 in myoblast accumulation during mouse muscle regeneration DUX4c over-expression activated proliferation of human primary myoblasts and inhibited their differentiation. Altogether, these results suggested that DUX4c could be involved in muscle regeneration and that changes in its expression could contribute to the FSHD pathology.

Magnetic labeling of non-phagocytic adherent cells with iron oxide nanoparticles: a comprehensive study.

Small particles of iron oxide (SPIO) and ultrasmall particles of iron oxide (USPIO), inducing a strong negative contrast on T(2) and T(2)*-weighted MR images, are the most commonly used systems for the magnetic labeling of cultured cells and their subsequent detection by magnetic resonance imaging (MRI). The purpose of this work is to study the influence of iron incubation concentration, nanoparticle size and nanoparticle coating on the magnetic labeling and the viability of non-phagocytic adherent cells in culture. The magnetic labeling of 3T6 fibroblasts was studied by T(2)-weighted MRI at 4.7 T and by dosing-or cytochemical revealing-of iron through methods based on Perl's Prussian blue staining. Cells were incubated for 48 h with increasing iron concentrations of SPIO (25-1000 microg Fe/ml Endorem. Sinerem, a USPIO (20-40 nm) coated with neutral dextran, and Resovist (65 nm), a SPIO bearing an anionic carboxydextran coating, were compared with Endorem (dextran-coated, 80-150 nm) as magnetic tags. The iron loading of marrow stromal cell primary cultures (MSCs) isolated from rat femurs was compared with that of 3T6 fibroblasts. The SPIO-labeling of cells with Endorem was found to be dependent on the iron incubation concentration. MSCs, more sparsely distributed in the culture, exhibited higher iron contents than more densely populated 3T6 fibroblast cultures. A larger iron loading was achieved with Resovist than with Endorem, which in turn was more efficient than Sinerem as a magnetic tag. The magnetic labeling of cultured non-phagocytic adherent cells with iron oxide nanoparticles was thus found to be dependent on the relative concentration of the magnetic tag and of the cells in culture, on the nanoparticle size, and on the coating type. The viability of cells, estimated by methods assessing cell membrane permeability, was not affected by magnetic labeling in the conditions used in this work.