Cytoskeleton changes and impaired motility of monocytes at modelled low gravity

Summary.: Investigations performed in space have shown that gravity changes affect important cellular mechanisms like proliferation, differentiation, genetic expression, cytoskeletal architecture, and motility in lymphocytes, monocytes, and other mammalian cells. In particular, a dramatic depression of the mitogenic in vitro activation of human peripheral blood lymphocytes was observed at low gravity. The hypothesis of the present work is that a reduced interaction between T lymphocytes and monocytes, essential for the second signalling pathway, might be one of the reasons for the observed depression of the in vitro activation of human lymphocytes. Cell motility and with it a continuous rearrangement of the cytoskeletal network within the cell is essential for cell-to-cell contacts. Whereas nonactivated lymphocytes in suspension are highly motile at low gravity, no data are available so far on the motility of adherent monocytes. It thus can be argued that impaired monocyte locomotion and cytoskeletal changes could be responsible for a reduced interaction of monocytes with T lymphocytes. In this study, the locomotion ability of J-111 cells, an adherent monocyte cell line, attached to colloidal gold particles on coverslips and exposed to modelled low gravity in the random positioning machine was found to be severely reduced compared with that of controls and the structures of actin, tubulin, and vinculin were affecte

New perspective for an old drug: Can naloxone be considered an antioxidant agent?

Background: Experimental evidence indicates that Naloxone (NLX) holds antioxidant properties. The present study aims at verifying the hypothesis that NLX could prevent oxidative stress induced by hydrogen peroxide (H2O2) in PC12 cells.Methods: To investigate the antioxidant effect of NLX, initially, we performed electrochemical experiments by means of platinum-based sensors in a cell-free system. Subsequently, NLX was tested in PC12 cells on H2O2induced overproduction of intracellular levels of reactive-oxygen-species (ROS), apoptosis, modification of cells' cycle distribution and damage of cells' plasma membrane.Results: This study reveals that NLX counteracts intracellular ROS production, reduces H2O2-induced apoptosis levels, and prevents the oxidative damage-dependent increases of the percentage of cells in G2/M phase. Likewise, NLX protects PC12 cells from H2O2- induced oxidative damage, by preventing the lactate dehydrogenase (LDH) release. Moreover, electrochemical experiments confirmed the antioxidant properties of NLX.Conclusion: Overall, these findings provide a starting point for studying further the protective effects of NLX on oxidative stress

Effective SARS-CoV-2 antiviral activity of hyperbranched polylysine nanopolymers

The coronavirus pandemic (COVID-19) had spread rapidly since December 2019, when it was first identified in Wuhan, China. As of April 2021, more than 130 million cases have been confirmed, with more than 3 million deaths, making it one of the deadliest pandemics in history. Different approaches must be put in place to confront a new pandemic: community-based behaviours (i.e., isolation and social distancing), antiviral treatments, and vaccines. Although behaviour-based actions have produced significant benefits and several efficacious vaccines are now available, there is still an urgent need for treatment options. Remdesivir represents the first antiviral drug approved by the Food and Drug Administration for COVID-19 but has several limitations in terms of safety and treatment benefits. There is still a strong request for other effective, safe, and broad-spectrum antiviral systems in light of future emergent coronaviruses. Here, we describe a polymeric nanomaterial derived from l-lysine, with an antiviral activity against SARS-CoV-2 associated with a good safety profile in vitro. Nanoparticles of hyperbranched polylysine, synthesized by l-lysine's thermal polymerization catalyzed by boric acid, effectively inhibit the SARS-CoV-2 replication. The virucidal activity is associated with the charge and dimension of the nanomaterial, favouring the electrostatic interaction with the viral surface being only slightly larger than the virions' dimensions. Low-cost production and easiness of synthesis strongly support the further development of such innovative nanomaterials as a tool for potential treatments of COVID-19 and, in general, as broad-spectrum antivirals. This journal i

Evaluation of a real time pcr system for detection of Escherichia coli O157:H7 in ground beef

La infección por Escherichia coli O157:H7 es causa de diarrea con o sin sangre, colitis hemorrágica y síndrome urémico hemolítico (SUH) en humanos. El principal reservorio animal de E. coli O157:H7 son los bovinos y la carne bovina molida es una potencial fuente de infección. El objetivo de este trabajo fue evaluar un sistema comercial de PCR en tiempo real para la detección de E. coli O157:H7. Se determinó límite de detección, selectividad y robustez. Se contaminaron experimentalmente 50 muestras de carne molida bovina con 10 cepas de E. coli O157:H7 (10, 100 y 1000 UFC/25 g) y 20 cepas de bacterias no-E. coli O157:H7 (1000 UFC/25 g). El límite de detección dependió de la cepa analizada, el valor mínimo fue 6,1 UFC/25 g. La robustez fue óptima al modificar diferentes variables. Se obtuvo 100% de inclusividad y 100% de exclusividad. La técnica evaluada es una alternativa apropiada para la detección de E. coli O157:H7 a partir de carne bovina molida.Shiga toxin-producing Escherichia coli (STEC) cause non-bloody or bloody diar- rhea, hemorrhagic colitis and hemolytic uremic syndrome (HUS) in humans. Cattle are a major animal reservoir for E. coli O157:H7 and the ground beef are a potential source of infection. The aim of the present study was to evaluate a real time PCR commercial system for detection of E. coli O157:H7. Detection limit, selectivity and robustness were established. Fifty samples of ground beef were experimentally contaminated with 10 E. coli O157:H7 strains (10, 100 y 1000 CFU/25 g) and 20 non-E. coli O157:H7 strains (1000 CFU/25 g). The detection limit depended on the strain analyzed, the minimum values was 6,1 cfu/15 g. A good robustness was observed when different variables were introduced. Inclusivity and exclusivity were of 100%. The evaluated technique is an appropriate alternative for detection of E. coli O157:H7 from ground beef.Facultad de Ciencias Veterinaria

Evaluation of a real time pcr system for detection of Escherichia coli O157:H7 in ground beef

La infección por Escherichia coli O157:H7 es causa de diarrea con o sin sangre, colitis hemorrágica y síndrome urémico hemolítico (SUH) en humanos. El principal reservorio animal de E. coli O157:H7 son los bovinos y la carne bovina molida es una potencial fuente de infección. El objetivo de este trabajo fue evaluar un sistema comercial de PCR en tiempo real para la detección de E. coli O157:H7. Se determinó límite de detección, selectividad y robustez. Se contaminaron experimentalmente 50 muestras de carne molida bovina con 10 cepas de E. coli O157:H7 (10, 100 y 1000 UFC/25 g) y 20 cepas de bacterias no-E. coli O157:H7 (1000 UFC/25 g). El límite de detección dependió de la cepa analizada, el valor mínimo fue 6,1 UFC/25 g. La robustez fue óptima al modificar diferentes variables. Se obtuvo 100% de inclusividad y 100% de exclusividad. La técnica evaluada es una alternativa apropiada para la detección de E. coli O157:H7 a partir de carne bovina molida.Shiga toxin-producing Escherichia coli (STEC) cause non-bloody or bloody diar- rhea, hemorrhagic colitis and hemolytic uremic syndrome (HUS) in humans. Cattle are a major animal reservoir for E. coli O157:H7 and the ground beef are a potential source of infection. The aim of the present study was to evaluate a real time PCR commercial system for detection of E. coli O157:H7. Detection limit, selectivity and robustness were established. Fifty samples of ground beef were experimentally contaminated with 10 E. coli O157:H7 strains (10, 100 y 1000 CFU/25 g) and 20 non-E. coli O157:H7 strains (1000 CFU/25 g). The detection limit depended on the strain analyzed, the minimum values was 6,1 cfu/15 g. A good robustness was observed when different variables were introduced. Inclusivity and exclusivity were of 100%. The evaluated technique is an appropriate alternative for detection of E. coli O157:H7 from ground beef.Facultad de Ciencias Veterinaria

"In vivo" physiological experiments in simulated microgravity conditions on rat bon marrow cells mineralization

The main goal of this research is to further contribute to the validation of the clinostat Random Positioning Machine (RPM) for "in vivo" experiments by studying bone marrow cells mineralization in the rat. These cells were obtained from the bone shafts of the femora and cultured for 13 days. The production of calcified matrix was analyzed by Alizarin Red staining demostrating that calcium deposition was significantly decreased in RPM samples. Moreover, we demostrated what Alkaline phosphatase (ALP) activity, a marker of osteoblastic phenotype, is down regulate by simulated microgravity. Also in vitro experiments in coltured osteoblasts (first subcolture) exposed to RPM for 9 days confirm a strongly decreased mineralization and differentiation