Search results for "p24"
showing 10 items of 182 documents
Engineering a Circular Riboregulator in Escherichia coli
2020
RNAs of different shapes and sizes, natural or synthetic, can regulate gene expression in prokaryotes and eukaryotes. Circular RNAs have recently appeared to be more widespread than previously thought, but their role in prokaryotes remains elusive. Here, by inserting a riboregulatory sequence within a group I permuted intron-exon ribozyme, we created a small noncoding RNA that self-splices to produce a circular riboregulator in Escherichia coli . We showed that the resulting riboregulator can trans -activate gene expression by interacting with a cis -repressed messenger RNA. We characterized the system with a fluorescent reporter and with an antibiotic resistance marker, and we modeled thi…
Does Probiotic Yeast Act as Antigenotoxin?
2005
The effect of probiotic yeast Saccharomyces boulardii on genotoxicity induced by the well-known mutagen 4-nitroquinoline-N-oxide (4-NQO), as well as antibacterial (furazolidone) and antibiotic (nalidixic acid) drugs, has been studied using the short-term bacterial assay, SOS chromotest, with Escherichia coli PQ 37 as the test organism. It has been shown that S. boulardii possesses antigenotoxic activity, revealed by SOS chromotest, when coincubated with these genotoxins. A weaker antigenotoxic activity against the same compounds was observed with S. carlsbergensis, too.
The formation of hybrid complexes between isoenzymes of glyceraldehyde‐3‐phosphate dehydrogenase regulates its aggregation state, the glycolytic acti…
2019
The glycolytic enzyme glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH) has been traditionally considered a housekeeping protein involved in energy generation. However, evidence indicates that GAPDHs from different origins are tightly regulated and that this regulation may be on the basis of glycolysis‐related and glycolysis‐unrelated functions. In Saccharomyces cerevisiae, Tdh3 is the main GAPDH, although two other isoenzymes encoded by TDH1 and TDH2 have been identified. Like other GAPDHs, Tdh3 exists predominantly as a tetramer, although dimeric and monomeric forms have also been isolated. Mechanisms of Tdh3 regulation may thus imply changes in its oligomeric state or be based in its abil…
SALMO and S3M: A Saliva Model and a Single Saliva Salt Model for Equilibrium Studies.
2014
A model of synthetic saliva (SALMO, SALiva MOdel) is proposed for its use as standard medium inin vitroequilibrium and speciation studies of real saliva. The concentrations come out from the literature analysis of the composition of both real saliva and synthetic saliva. The chief interactions of main inorganic components of saliva, as well as urea and amino acids, are taken into account on the basis of a complex formation model, which also considers the dependence of the stability constants of these species on ionic strength and temperature. These last features allow the modelling of the speciation of saliva in different physiological conditions deriving from processes like dilution, pH, a…
Poly-sarcosine and poly(ethylene-glycol) interactions with proteins investigated using molecular dynamics simulations
2018
Nanoparticles coated with hydrophilic polymers often show a reduction in unspecific interactions with the biological environment, which improves their biocompatibility. The molecular determinants of this reduction are not very well understood yet, and their knowledge may help improving nanoparticle design. Here we address, using molecular dynamics simulations, the interactions of human serum albumin, the most abundant serum protein, with two promising hydrophilic polymers used for the coating of therapeutic nanoparticles, poly(ethylene-glycol) and poly-sarcosine. By simulating the protein immersed in a polymer-water mixture, we show that the two polymers have a very similar affinity for the…
3D polylactide-based scaffolds for studying human hepatocarcinoma processes in vitro
2012
We evaluated the combination of leaching techniques and melt blending of polymers and particles for the preparation of highly interconnected three-dimensional polymeric porous scaffolds for in vitro studies of human hepatocarcinoma processes. More specifically, sodium chloride and poly(ethylene glycol) (PEG) were used as water-soluble porogens to form porous and solvent-free poly(L,D-lactide) (PLA)-based scaffolds. Several characterization techniques, including porosimetry, image analysis and thermogravimetry, were combined to improve the reliability of measurements and mapping of the size, distribution and microarchitecture of pores. We also investigated the effect of processing, in PLA-ba…
Experimental and Modeling Analyses of Human Motion Across the Static Magnetic Field of an MRI Scanner
2021
It is established that human movements in the vicinity of a permanent static magnetic field, such as those in magnetic resonance imaging (MRI) scanners induce electric fields in the human body; this raises potential severe risks of health to radiographers and cleaners exposed routinely to these fields in MRI rooms. The relevant directives and parameters, however, are based on theoretical models, and accurate studies on the simulation of the effects based on human movement data obtained in real conditions are still lacking. Two radiographers and one cleaner, familiar with MRI room activities and these directives, were gait analyzed during the execution of routine job motor tasks at different…
In vitro antibacterial and biofilm inhibitory activity of the sawdust essential oil of Tetraclinis articulata (vahl) against catheter-associated Stap…
2021
Abstract The aim of the present study was to determine the chemical composition, antibacterial and antibiofilm activities of the essential oil of sawdust from root burl wood of T. articulata. Nine strains including 8 clinical isolates from catheters-related infections and one ATCC 25923 were tested. Twenty-seven different compounds were identified by GC–MS in the essential oil of T. articulata extracted by hydrodistillation. Carvacrol and cedrol were the principal compounds representing 34.37 ± 0.07 and 11.07 ± 0.09 respectively. The EO had a strong antibacterial activity against all strains including one Multidrug-Resistant (MDR) and two Methicillin-Resistant S. aureus strains. Inhibition …
Myriocin-induced adaptive laboratory evolution of an industrial strain of Saccharomyces cerevisiae reveals its potential to remodel lipid composition…
2020
The modification of lipid composition allows cells to adjust membrane biophysical properties in response to changes in environmental temperature. Here, we use adaptive laboratory evolution (ALE) in the presence of myriocin, a sphingolipid (SLs) biosynthesis inhibitor, to remodel the lipid profile of an industrial yeast strain (LH) of Saccharomyces cerevisiae. The approach enabled to obtain a heterogeneous population (LHev) of myriocin‐tolerant evolved clones characterized by its growth capacity at high temperature. Myriocin exposure also caused tolerance to soraphen A, an inhibitor of the acetyl‐CoA carboxylase Acc1, the rate‐limiting enzyme in fatty acid de novo production, supporting a ch…
Effect of environmental conditions on the durability of polycarbonate for the protection of cultural heritage sites.
2019
Polycarbonate is a good material for covering and protecting cultural heritage sites because of its durability, mechanical properties, and transparency. However, polycarbonate degrades under environmental weathering with a significant decrease of physical and mechanical properties and loss of transparency. In this work, the contemporary presence of ultraviolet irradiation and different temperature and moisture conditions have been taken into account to study the environmental degradation of this polymer with regard to its mechanical and optical properties. The photo-oxidation reactions cause a decrease in the molecular weight and the formation of many oxygenated species. The hydrolytic sci…