Occupational health surveillance of healthcare workers during COVID 19 pandemic: a narrative review.

BACKGROUND AND AIMS: Current literature has increasingly highlighted the risk of spreading the SARS-COV-2 infection in healthcare settings and showed the need for occupational health surveillance of HCWs during the current epidemiological emergency from COVID-19, as a preventive measure to minimize the spread of the infection. The purpose of this narrative review was to evaluate the literature and discover what the latest developments are about the management of the occupational health surveillance of healthcare workers (HCWs) during COVID-19 pandemic. METHODS: We searched for publications in MEDLINE, Pubmed and Google Scholar using selected keywords. Each article was reviewed and categorized into one or more of the following three categories based on its subject matter: early diagnosis of COVID-19 in HCWs, detection of worker susceptibility to severe COVID-19, medical examination of HCWs returning to work after COVID-19. RESULTS: Selected articles showed the RT-PCR test for Sars-CoV-2 as the gold standard to enable rapid identification of infected HCWs; an effective schedule of occupational health surveillance allows the identification of the susceptibility of the workers to severe Covid-19 and protect HCWs returning to work from the disease. CONCLUSIONS: The findings of the present narrative review show the need to strenghten the occupational health surveillance of HCWs during the current COVID-19 pandemic, with the aim not only to contain the spread of the infection in healthcare settings, but also to protect HCWs coming back to work after the disease.

The vascular architecture of the pancreatic islets: A homage to August Krogh.

The vascular network supporting the islets of Langerhans represents a highly specialised system of arterioles, capillaries and venules. Several features of the islet vasculature (density and fenestration of the capillaries) ensure rapid exchange of nutrients and hormones, which is central to the islets' capacity to control of systemic metabolism via reciprocal changes of insulin and glucagon secretion. Here we discuss how changes in islet blood flow may underlie pulsatile insulin secretion, which becomes impaired in type-2 diabetes. Improved understanding of the architecture and regulation of pancreas/islet blood flow may therefore illuminate the causes underlying this common metabolic disorder. The pioneering work of August Krogh on blood flow, oxygen diffusion and capillary anatomy (that was awarded with the Nobel Prize in 1920) is a cornerstone in these efforts and remains relevant to today's research.

Plasma membrane characterization, by scanning electron microscopy, of multipotent myoblasts-derived populations sorted using dielectrophoresis.

Multipotent progenitor cells have shown promise for use in biomedical applications and regenerative medicine. The implementation of such cells for clinical application requires a synchronized, phenotypically and/or genotypically, homogenous cell population. Here we have demonstrated the implementation of a biological tag-free dielectrophoretic device used for discrimination of multipotent myoblastic C2C12 model. The multipotent capabilities in differentiation, for these cells, diminishes with higher passage number, so for cultures above 70 passages only a small percentage of cells is able to differentiate into terminal myotubes. In this work we demonstrated that we could recover, above 96% purity, specific cell types from a mixed population of cells at high passage number without any biological tag using dielectrophoresis. The purity of the samples was confirmed by cytometric analysis using the cell specific marker embryonic myosin. To further investigate the dielectric properties of the cell plasma membrane we co-culture C2C12 with similar size, when in suspension, GFP-positive fibroblast as feeder layer. The level of separation between the cell types was above 98% purity which was confirmed by flow cytometry. These levels of separation are assumed to account for cell size and for the plasma membrane morphological differences between C2C12 and fibroblast unrelated to the stages of the cell cycle which was assessed by immunofluorescence staining. Plasma membrane conformational differences were further confirmed by scanning electron microscopy.

Biomarker-free dielectrophoretic sorting of differentiating myoblast multipotent progenitor cells and their membrane analysis by Raman spectroscopy.

Myoblasts are muscle derived mesenchymal stem cell progenitors that have great potential for use in regenerative medicine, especially for cardiomyogenesis grafts and intracardiac cell transplantation. To utilise such cells for pre-clinical and clinical applications, and especially for personalized medicine, it is essential to generate a synchronised, homogenous, population of cells that display phenotypic and genotypic homogeneity within a population of cells. We demonstrate that the biomarker-free technique of dielectrophoresis (DEP) can be used to discriminate cells between stages of differentiation in the C2C12 myoblast multipotent mouse model. Terminally differentiated myotubes were separated from C2C12 myoblasts to better than 96% purity, a result validated by flow cytometry and Western blotting. To determine the extent to which cell membrane capacitance, rather than cell size, determined the DEP response of a cell, C2C12 myoblasts were co-cultured with GFP-expressing MRC-5 fibroblasts of comparable size distributions (mean diameter ∼10 µm). A DEP sorting efficiency greater than 98% was achieved for these two cell types, a result concluded to arise from the fibroblasts possessing a larger membrane capacitance than the myoblasts. It is currently assumed that differences in membrane capacitance primarily reflect differences in the extent of folding or surface features of the membrane. However, our finding by Raman spectroscopy that the fibroblast membranes contained a smaller proportion of saturated lipids than those of the myoblasts suggests that the membrane chemistry should also be taken into account.