606 research outputs found

    Combined antimicrobial use of essential oils and bacteriocin bacLP17 as seafood biopreservative to control Listeria monocytogenes both in planktonic and in sessile forms

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    The antilisterial activity of Thymus vulgaris, Salvia officinalis essential oils (EOs) and bacteriocin bacLP17 (previously isolated from seafood) was determined, using the compounds alone and in combination. The Disk Diffusion, Minimal Inhibitory Concentration (MIC) and Agar Well Diffusion assays were used to evaluate the effectiveness of the compounds against 12 Listeria monocytogenes in planktonic form, whereas the anti-Listeria biofilm activity was determined against the same strains in optical density (O.D.) at 570 nm, with crystal violet staining method. The lowest MIC values resulted for T. vulgaris EO and bacLp17 (0.5 μl/ml and 2 μl/ml, respectively). The combinations with the best results, expressed as FIC-Index, were T. vulgaris/S. officinalis EOs and EOs/bacLp17. The anti-biofilm activity of single EOs and bacLP17 was similar, whereas the combined use of the two kinds of EOs led to a synergistic activity. Lastly, the best anti-biofilm effect was observed with the combination bacLP17/S. officinalis and bacLP17/T. vulgaris, compared to both control and the single use of the EOs. The present study suggests that the combination of natural compounds such as T. vulgaris, S. officinalis EOs and bacLp17 may be a useful approach to the control of planktonic and sessile cells of L. monocytogenes in seafood products

    Ready-to-eat sandwiches as source of pathogens endowed with antibiotic resistance and other virulence factors

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    The aim of this study was to evaluate and characterize the bacterial load present in twenty-four Ready-To-Eat (RTE) sandwiches, purchased at refrigerated vending machines and supermarkets in the province of Modena (Italy). We isolated 54 bacterial strains, including pathogens of interest in food safety, such as Listeria, Staphylococcus, Enterococcus, Yersinia, Aeromonas and Acinetobacter spp. Phenotypic tests have been performed on these pathogens to detect the presence of virulence factors, such as gelatinase production and hemolytic capability. To test their antibiotic resistance features, the minimum inhibitory concentration (MIC) against eight commonly used antibiotics (Amikacin, Ciprofloxacin, Ampicillin, Oxacillin, Imipenem, Tetracycline, Erythromycin and Vancomycin) was also evaluated. The results showed that among the 54 isolates, fifty percent (50%) belonged to harmless microorganisms (Leuconostoc and Lactococcus), whereas the remaining fifty percent (50%) included pathogenic bacteria (Listeria ivanovii, Listeria monocytogenes, Staphylococcus aureus, Yersinia, and Citrobacter spp.), species responsible for pathologies often difficult to treat due to the presence of antibiotic resistance features. This study demonstrates the importance of thorough controls, both during the production and marketing of RTE food like sandwiches, to avoid reaching the infectious load and the onset of pathologies, particularly dangerous for old and immunocompromised patients

    Synchronous bilateral Warthin's tumours of the parotid glands: a case report

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    Warthin's tumour is the most frequent monomorphic adenoma of the major salivary glands, representing about 2-15% of all parotid tumours. Most of the multifocal Warthin's tumours are unilateral, whereas bilateral Warthin's tumours are far less common; bilateral Warthin's tumours are metachronous with few synchronous cases having been described in the literature. The Authors present an interesting case of simultaneously occurring bilateral Warthin's tumours growing in the parotid glands

    Controversial Aspects Displayed by Enterococci: Probiotics or Pathogens?

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    For centuries, selected Enterococci, facultative anaerobic, nonspore-forming Gram-positive bacteria belonging to the Lactic Acid Bacteria (LAB), have been widely used in the production of a variety of fermented and nonfermented food products ranging from dairy and meat products to vegetable and sea foods. Enterococci have also properties that are of technological interest in the food industry, and some strains have been used as probiotics for the maintenance of normal intestinal microbiota, stimulation of the immune system, and improvement of the nutritional value of foods and feeds in humans and animals However, following the emergence of antibiotic-resistant (AMR) enterococci and particularly of the vancomycin-resistant enterococci (VRE), these microorganisms have turned from generally recognized as safe (GRAS) for human consumption to significant pathogens threatening human health and thriving in the hospital environment. Thus, recently the trend of using enterococci as probiotics for human consumption is in debate due to the controversial aspects of these bacteria which appear to be “friends and foes

    u-RANIA: a neutron detector based on \mu -RWELL technology

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    In the framework of the ATTRACT-uRANIA project, funded by the European Community, we are developing an innovative neutron imaging detector based on micro-Resistive WELL (μ\mu -RWELL) technology. The μ\mu -RWELL, based on the resistive detector concept, ensuring an efficient spark quenching mechanism, is a highly reliable device. It is composed by two main elements: a readout-PCB and a cathode. The amplification stage for this device is embedded in the readout board through a resistive layer realized by means of an industrial process with DLC (Diamond-Like Carbon). A thin layer of B4_4C on the copper surface of the cathode allows the thermal neutrons detection through the release of 7^7Li and α\alpha particles in the active volume. This technology has been developed to be an efficient and convenient alternative to the 3^3He shortage. The goal of the project is to prove the feasibility of such a novel neutron detector by developing and testing small planar prototypes with readout boards suitably segmented with strip or pad read out, equipped with existing electronics or readout in current mode. Preliminary results from the test with different prototypes, showing a good agreement with the simulation, will be presented together with construction details of the prototypes and the future steps of the project.Comment: Prepared for the INSTR20 Conference Proceeding for JINS

    The alpha-7 nicotinic acetylcholine receptor is involved in a direct inhibitory effect of nicotine on GnRH release : In vitro studies

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    The activation of nicotinic cholinergic receptors (nAChR) inhibits the reproductive axis; however, it is not clear whether nicotine may directly modulate the release of hypothalamic gonadotropin-releasing hormone (GnRH). Experiments carried out in GT1-1 immortalized GnRH neurons reveal the presence of a single class of high affinity \u3b14\u3b22 and \u3b17 nAchR subtypes. The exposure of GT1-1\ua0cells to nicotine does not modify the basal accumulation of GnRH. However, nicotine was found to modify GnRH pulsatility in perifusion experiments and inhibits, the release of GnRH induced by prostaglandin E1 or by K(+)-induced cell depolarization; these effects were reversed by D-tubocurarine and \u3b1-bungarotoxin. In conclusion, the results reported here indicate that: functional nAChRs are present on GT1-1\ua0cells, the activation of the \u3b1-bungarotoxin-sensitive subclass (\u3b17) produces an inhibitory effect on the release of GnRH and that the direct action of nicotine on GnRH neurons may be involved in reducing fertility of smokers

    MiR-128 up-regulation inhibits Reelin and DCX expression and reduces neuroblastoma cell motility and invasiveness

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    MicroRNAs are a class of sophisticated regulators of gene expression, acting as post-transcriptional inhibitors that recognize their target mRNAs through base pairing with short regions along the 3'UTRs. Several microRNAs are tissue specific, suggesting a specialized role in tissue differentiation or maintenance, and quite a few are critically involved in tumorigenesis. We studied miR-128, a brain-enriched microRNA, in retinoic acid-differentiated neuroblastoma cells, and we found that this microRNA is up-regulated in treated cells, where it down-modulates the expression of two proteins involved in the migratory potential of neural cells: Reelin and DCX. Consistently, miR-128 ectopic overexpression suppressed Reelin and DCX, whereas the LNA antisense-mediated miR-128 knockdown caused the two proteins to increase. Ectopic miR-128 overexpression reduced neuroblastoma cell motility and invasiveness, and impaired cell growth. Finally, the analysis of a small series of primary human neuroblastomas showed an association between high levels of miR-128 expression and favorable features, such as favorable Shimada category or very young age at diagnosis. Thus, we provide evidence for a role for miR-128 in the molecular events modulating neuroblastoma progression and aggressiveness

    Limits on light-speed anisotropies from Compton scattering of high-energy electrons

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    The possibility of anisotropies in the speed of light relative to the limiting speed of electrons is considered. The absence of sidereal variations in the energy of Compton-edge photons at the ESRF's GRAAL facility constrains such anisotropies representing the first non-threshold collision-kinematics study of Lorentz violation. When interpreted within the minimal Standard-Model Extension, this result yields the two-sided limit of 1.6 x 10^{-14} at 95% confidence level on a combination of the parity-violating photon and electron coefficients kappa_{o+} and c. This new constraint provides an improvement over previous bounds by one order of magnitude.Comment: 4 pages, 4 figure

    A new limit on the light speed isotropy from the GRAAL experiment at the ESRF

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    When the electrons stored in the ring of the European Synchrotron Radiation Facility (ESRF, Grenoble) scatter on a laser beam (Compton scattering in flight) the lower energy of the scattered electron spectra, the Compton Edge (CE), is given by the two body photon-electron relativistic kinematics and depends on the velocity of light. A precision measurement of the position of this CE as a function of the daily variations of the direction of the electron beam in an absolute reference frame provides a one-way test of Relativistic Kinematics and the isotropy of the velocity of light. The results of GRAAL-ESRF measurements improve the previously existing one-way limits, thus showing the efficiency of this method and the interest of further studies in this direction.Comment: Proceed. MG12 meeting, Paris, July, 200
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