A Fluorogenic Pseudoinfection Assay to Probe Transfer and Distribution of Influenza Viral Contents to Target Vesicles.

Fusion of enveloped viruses with endosomal membranes and subsequent release of the viral genome into the cytoplasm are crucial to the viral infection cycle. It is often modeled by performing fusion between virus particles and target lipid vesicles. We utilized fluorescence microscopy to characterize the kinetic aspects of the transfer of influenza viral ribonucleoprotein (vRNP) complexes to target vesicles and their spatial distribution within the fused volumes to gain deeper insight into the mechanistic aspects of endosomal escape. The fluorogenic RNA-binding dye QuantiFluor (Promega) was found to be well-suited for direct and sensitive microscopic observation of vRNPs which facilitated background-free detection and kinetic analysis of fusion events on a single particle level. To determine the extent to which the viral contents are transferred to the target vesicles through the fusion pore, we carried out virus-vesicle fusion in a side-by-side fashion. Measurement of the Euclidean distances between the centroids of superlocalized membrane and content dye signals within the fused volumes allowed determination of any symmetry (or the lack thereof) between them as expected in the event of transfer (or the lack thereof) of vRNPs, respectively. We found that, in the case of fusion between viruses and 100 nm target vesicles, ∼39% of the events led to transfer of viral contents to the target vesicles. This methodology provides a rapid, generic, and cell-free way to assess the inhibitory effects of antiviral drugs and therapeutics on the endosomal escape behavior of enveloped viruses.

Prevention of Gestational Diabetes Mellitus (GDM) and Probiotics: Mechanism of Action: A Review.

BACKGROUND: Gestational Diabetes Mellitus (GDM) is a health problem that is increasing around the world. INTRODUCTION: Prevention of GDM, rather than treatment, could have several benefits in terms of both health and economic cost. Even a slight reduction in maternal glucose in non-diabetic women, particularly in women at high risk for GDM, may have significant benefits for pregnancy results and the future health of off-springs. Probiotics are a relatively new intervention, which are assessed by mothers' metabolism, and can reduce blood sugar levels, prevent gestational diabetes and reduce the maternal and fetal complications resulting from it. The aim of this study was to review the studies on the prevention of gestational diabetes and assess the potential beneficial effects of probiotics on gestational diabetes and their possible mechanism of action. METHODS: Articles compiled through clinical trials indexed in PubMed, Science Direct, Cochran, and Medlib between 2000 and 2017, with the keywords probiotics, prevention, and gestational diabetes mellitus were selected. RESULTS: Considering the potential of probiotics in the modulation of gut microbiota, naturalization increases intestinal permeability, regulation of pro-inflammatory mediators' secretion and thereby controlling local and systemic inflammation results in decreasing intestinal permeability, enhancing the immune system. It likely has the ability to prevent or control diabetes during pregnancy although confirmatory studies are still needed. CONCLUSION: Experimental and clinical evidence support the supposition that the modulation of the gut microbiota via probiotic microorganisms could be effective in the prevention of gestational diabetes mellitus.