Disparate exposure to physically demanding working conditions in France.

BACKGROUND: Our study was aimed at examining disparate exposure to physically demanding working conditions in France, a key objective being to identify the types of employees/jobs requiring high-priority preventive actions. METHODS: We analyzed the data from the 2017 French nationwide cross-sectional survey (SUMER) on occupational hazards to which French employees in various sectors were subjected. The prevalence of several types of physically demanding working conditions (lifting of heavy loads, awkward body postures, vibrations, noise, and extreme temperatures) was explored. Potential associations of individual and job characteristics with these factors of hardship at work were studied by multivariate logistic regression. RESULTS: In total, 48% of employees were exposed to at least one physically demanding working condition and 24.8% were exposed to multiple constraints. While managers and intellectual professionals were exposed relatively infrequently to physical constraints, blue-collar workers experienced the highest frequency of exposure. On the one hand, the role of company size depended on the factor of hardship at work considered; on the other hand, employees in large-scale companies were generally less exposed. As expected, employees in the construction industry were the most exposed to physical constraints; that said, our results also show that some activities in the services sector (e.g., personal care, administrative and support services) were quite significantly affected by a wide array of physically demanding working conditions. CONCLUSION: Notwithstanding the establishment in France of Plans de Santé au travail (preventive workplace health and safety plans), occupational risks were found to be high, and above all, they were unevenly distributed among the various socio-professional categories, and strongly contributed to social inequalities in health. Our results identify the types of publics to be designated as high-priority targets for preventive measures aimed at reducing the adverse impacts of physically demanding working conditions and the incidence of associated musculoskeletal disorders.

[Methods for the analysis and treatment of cost data by micro- and gross-costing approaches]. / Méthodes d'analyse et de traitement des données de coût : approches par « micro-costing ¼ et « gross-costing ¼.

This work addresses the analysis of individual cost data in the setting of interventional or observational studies using statistical analysis software once the costs per patient have been estimated. It is in fact necessary to be able to present and describe data in an appropriate manner in each of the studied health strategies and to test whether the difference in costs observed between treatment groups is due to chance or not. Furthermore, cost analysis differs from conventional statistical analysis in that cost data have a certain number of specific properties, including their use by health decision-makers. This work also addresses the difficulties that generally arise in regard to the distribution of cost; it explains why the mathematical average constitutes the only relevant measure for economists; and it outlines which analyses are required for inter-strategy cost comparisons. It also covers the issue of missing or censored data, features that are inherent to information collected regarding costs and to sensitivity analyses.

Subcellular distribution of calponin and caldesmon in rat hippocampus.

Caldesmon and calponin are two actin- and calmodulin-binding proteins involved in the 'actin-linked' regulation of smooth muscle and non-muscle Mg(2+)-actin-activated myosin II ATPase activity. In the present report we show that caldesmon and calponin are present in the post-synaptic side of symmetric synapses and accumulate in the post-synaptic densities of asymmetric synapses. Caldesmon- and calponin-immunoreactivities are also observed at the plasma membrane of the hippocampal neurones. Finally, while caldesmon seems strictly distributed to neurones, acidic calponin is present in both neurones and astrocytes.

Beta-actin immunoreactivity in rat microglial cells: developmental pattern and participation in microglial reaction after kainate injury.

In the present study we investigated the developmental and post-injury pattern of beta-actin immunoreactivity in rat brain. Our data suggest that beta-actin is higher in microglia-macrophages than in any other central nervous system cell type, including neurons and astrocytes. We also show that beta-actin immunoreactivity is particularly high in ameboid-macrophagic cells, suggesting a role on the plastic changes that these cells experience during maturation or after activation.

Acidic calponin immunoreactivity in postnatal rat brain and cultures: subcellular localization in growth cones, under the plasma membrane and along actin and glial filaments.

Acidic calponin, an F-actin-binding protein, is particularly enriched in brain, where calponin protein and mRNA are mainly expressed by neurons. The presence of calponin immunoreactivity in cultured astroglial cells has been reported, but the presence of acidic calponin in astrocytes in vivo appears equivocal. For the present study, we raised a specific polyclonal antibody against the 16-residue synthetic peptide covering the sequence E311-Q326 (EYPDEYPREYQYGDDQ) situated at the carboxy-terminal end of rat acidic calponin, and we investigated the cellular and subcellular localization of the protein in the developing central nervous system. Our results show that acidic calponin is particularly enriched in: (i) growth cones and submembranous fields of maturing cerebellar and cortical cells, where it codistributes with microfilaments and (ii) glial cells in vivo, including radial glia, glia limitans, Bergmann glia and mature astrocytes, and ex vivo, where acidic calponin strongly colocalizes with intermediate glial fibrillary acidic protein (GFAP) and vimentin filaments. Finally, up to four acidic calponin subtypes with different isoelectric point (pI) values were identified by two-dimensional gel electrophoresis of cerebellar and hippocampal extracts. The more acidic isoforms were developmentally regulated. As only one single mRNA for acidic calponin has been identified, these isoforms must reflect postsynthesis changes probably related to the particular functions of acidic calponin in maturing cells. Although brain acidic calponin's exact role remains uncertain, the present data suggest that it is involved in neuronal and glial plasticity.

Distribution of caldesmon and of the acidic isoform of calponin in cultured cerebellar neurons and in different regions of the rat brain: an immunofluorescence and confocal microscopy study.

Caldesmon and calponin are two F-actin-binding and calcium-calmodulin-dependent proteins. In smooth muscle and nonmuscle cells both proteins are localized on actin filaments. Using one- or two-dimensional gel electrophoresis followed by the Western blot technique, and by immunofluorescence studies, we have given evidence that calponin is also present in rat and pig brain. In the present study, for the first time, we demonstrate caldesmon- and calponin-specific immunoreactivities in cerebellar cultured neurons. In the rat central nervous system these antibodies mainly stain neuronal cell bodies and dendrites. By confocal analysis we observed that calponin and caldesmon are located in the actomyosin domain although the total actin and myosin were not saturated. In many cases it is clear that these two proteins are adjacent rather than superimposed in the same domain of the cell. These results are compatible with the functional role of caldesmon and calponin in the regulation of the actomyosin activity as described by others and suggest that they are part of the contractile apparatus of neural cells.