3,343 research outputs found

    Tomato Juice Consumption Modifies the Urinary Peptide Profile in Sprague-Dawley Rats with Induced Hepatic Steatosis

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    Non-alcoholic fatty liver disease (NAFLD) is the most common liver disorder in Western countries, with a high prevalence, and has been shown to increase the risk of type 2 diabetes, cardiovascular disease (CVD), etc. Tomato products contain several natural antioxidants, including lycopene—which has displayed a preventive effect on the development of steatosis and CVD. Accordingly, the aim of the present work was to evaluate the effect of tomato juice consumption on the urinary peptide profile in rats with NAFLD induced by an atherogenic diet and to identify potential peptide biomarkers for diagnosis. Urine samples, collected weekly for four weeks, were analyzed by capillary electrophoresis (CE) coupled to a mass spectrometer (MS). A partial least squares-discriminant analysis (PLS-DA) was carried out to explore the association between differential peptides and treatments. Among the 888 peptides initially identified, a total of 55 were obtained as potential biomarkers. Rats with steatosis after tomato juice intake showed a profile intermediate between that of healthy rats and that of rats with induced hepatic steatosis. Accordingly, tomato products could be considered as a dietary strategy for the impairment of NAFLD, although further research should be carried out to develop a specific biomarkers panel for NAFLD

    Land use change in a Mediterranean metropolitan region and its periphery: Assessment of conservation policies through CORINE land cover data and Markov models

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    Sustainable territorial management requires reliable assessment of the impact of conservation policies on landscape structure and dynamics. Euro-Mediterranean regions present a remarkable biodiversity which is linked in part to traditional land use practices and which is currently threatened by global change. The effectiveness of one-decade conservation policies against land use changes was examined in Central Spain (Madrid Autonomous Community). A Markov model of landscape dynamics was parameterized with CORINE Land Cover information and transition matrices were obtained. The methods were applied in both protected and unprotected areas to examine whether the intensity and direction of key land use changes —urbanisation, agricultural intensification and land abandonment— differed significantly depending on the protection status of those areas. Protected areas experienced slower rates of agricultural intensification processes and faster rates of land abandonment, with respect to those which occurred in unprotected areas. It illustrates how simple mathematical tools and models —parameterized with available data— can provide to managers and policy makers useful indicators for conservation policy assessment and identification of land use transitions

    Impaired Mesopic Visual Acuity in Eyes with Early Age-Related Macular Degeneration

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    Purpose.: To determine photopic and mesopic distance high-contrast visual acuity (HC-VA) and low-contrast visual acuity (LC-VA) in eyes with early age-related macular degeneration (AMD). Methods.: Measurements were made in 22 subjects with early AMD and 28 healthy control subjects. Inclusion criteria included a photopic HC-VA of 20/25 or better. Distance VA was measured using HC (96%) and LC (10%) Bailey-Lovie logMAR letter charts under photopic (85 cd/m2) and mesopic (0.1–0.2 cd/m2) luminance conditions. Results.: Mean mesopic distance HC-VA and LC-VA were significantly worse (0.1 logMAR and 0.28 logMAR, respectively) in the early AMD group than in the control group. Under mesopic conditions, the mean difference between LC-VA and HC-VA was significantly greater in the early AMD (0.45 logMAR) than the control group (0.27 logMAR). Mean differences between mesopic versus photopic HC-VA and mesopic versus photopic LC-VA were significantly greater in the early AMD than the control group (0.13 and 0.32 logMAR of difference between the means, respectively). Sensitivity and specificity were significantly greater for mesopic LC-VA than for mesopic HC-VA (Receiver Operating Characteristics, area under the curve [AUC], 0.94 ± 0.030 and 0.76 ± 0.067, respectively). AUC values for photopic HC-VA and LC-VA were below 0.70. Conclusions.: Visual acuity testing under low luminance conditions emerged as an optimal quantitative measure of retinal function in early AMD

    Effect of Charge Substitutions at Residue His-142 on Voltage Gating of Connexin43 Channels

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    AbstractPrevious studies indicate that the carboxyl terminal of connexin43 (Cx43CT) is involved in fast transjunctional voltage gating. Separate studies support the notion of an intramolecular association between Cx43CT and a region of the cytoplasmic loop (amino acids 119–144; referred to as “L2”). Structural analysis of L2 shows two α-helical domains, each with a histidine residue in its sequence (H126 and H142). Here, we determined the effect of H142 replacement by lysine, alanine, and glutamate on the voltage gating of Cx43 channels. Mutation H142E led to a significant reduction in the frequency of occurrence of the residual state and a prolongation of dwell open time. Macroscopically, there was a large reduction in the fast component of voltage gating. These results resembled those observed for a mutant lacking the carboxyl terminal (CT) domain. NMR experiments showed that mutation H142E significantly decreased the Cx43CT-L2 interaction and disrupted the secondary structure of L2. Overall, our data support the hypothesis that fast voltage gating involves an intramolecular particle-receptor interaction between CT and L2. Some of the structural constrains of fast voltage gating may be shared with those involved in the chemical gating of Cx43

    Direct Evidence of the Exfoliation Efficiency and Graphene Dispersibility of Green Solvents toward Sustainable Graphene Production

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    Achieving a sustainable production of pristine high-quality graphene and other layered materials at a low cost is one of the bottlenecks that needs to be overcome for reaching 2D material applications at a large scale. Liquid phase exfoliation in conjunction with N-methyl-2-pyrrolidone (NMP) is recognized as the most efficient method for both the exfoliation and dispersion of graphene. Unfortunately, NMP is neither sustainable nor suitable for up-scaling production due to its adverse impact on the environment. Here, we show the real potential of green solvents by revealing the independent contributions of their exfoliation efficiency and graphene dispersibility to the graphene yield. By experimentally separating these two factors, we demonstrate that the exfoliation efficiency of a given solvent is independent of its dispersibility. Our studies revealed that isopropanol can be used to exfoliate graphite as efficiently as NMP. Our finding is corroborated by the matching ratio between the polar and dispersive energies of graphite and that of the solvent surface tension. This direct evidence of exfoliation efficiency and dispersibility of solvents paves the way to developing a deeper understanding of the real potential of sustainable graphene manufacturing at a large scale

    Molecular studies of phages-Klebsiella pneumoniae in mucoid environment: innovative use of mucolytic agents prior to the administration of lytic phages

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    Mucins are important glycoproteins that form a protective layer throughout the gastrointestinal and respiratory tracts. There is scientific evidence of increase in phage-resistance in the presence of mucin for some bacterial pathogens. Manipulation in mucin composition may ultimately influence the effectiveness of phage therapy. In this work, two clinical strains of K. pneumoniae (K3574 and K3325), were exposed to the lytic bacteriophage vB_KpnS-VAC35 in the presence and absence of mucin on a long-term co-evolution assay, in an attempt to mimic in vitro the exposure to mucins that bacteria and their phages face in vivo. Enumerations of the bacterial and phage counts at regular time intervals were conducted, and extraction of the genomic DNA of co-evolved bacteria to the phage, the mucin and both was performed. We determined the frequency of phage-resistant mutants in the presence and absence of mucin and including a mucolytic agent (N-acetyl L-cysteine, NAC), and sequenced them using Nanopore. We phenotypically demonstrated that the presence of mucin induces the emergence of bacterial resistance against lytic phages, effectively decreased in the presence of NAC. In addition, the genomic analysis revealed some of the genes relevant to the development of phage resistance in long-term co-evolution, with a special focus on the mucoid environment. Genes involved in the metabolism of carbohydrates were mutated in the presence of mucin. In conclusion, the use of mucolytic agents prior to the administration of lytic phages could be an interesting therapeutic option when addressing K. pneumoniae infections in environments where mucin is overproduced.The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This study has been funded by Instituto de Salud Carlos III (ISCIII) through the projects PI19/00878 and PI22/00323 and co-funded by the European Union, and by the Study Group on Mechanisms of Action and Resistance to Antimicrobials, GEMARA (SEIMC). (SEIMC, http://www.seimc.org/). This research was also supported by CIBERINFEC (CIBER21/13/00095) and by Personalized and precision medicine grant from the Instituto de Salud Carlos III (MePRAM Project, PMP22/00092). MT was financially supported by the Miguel Servet Research Programme (SERGAS and ISCIII). OP, LF-G, and ML were financially supported by the grants IN606A-2020/035, IN606B-2021/013, and IN606C-2022/002, respectively (GAIN, Xunta de Galicia). IB was financially supported by the pFIS program (ISCIII, FI20/00302). Finally, to thank to PIRASOA laboratory which is the reference laboratory for molecular typing of nosocomial pathogens and detection of mechanisms of resistance to antimicrobials of health interest in Andalusia, Virgen Macarena Hospital, Seville, to send us the clinical isolates. Thanks to Alvaro Pascual and Luis Martínez-Martínez from Virgen Macarena Hospital, Seville and Reina Sofia Hospital, Cordoba.S

    Increase in Incidence Rates and Risk Factors for Multidrug Resistant Bacteria in Septic Children: A Nationwide Spanish Cohort Study (2013–2019)

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    Drug-resistant bacteria; Sepsis; SurveillanceBacterias resistentes a los medicamentos; Sepsis; VigilanciaBacteris resistents als medicaments; Sèpsia; VigilànciaThe emergence of multidrug-resistant (MDR) bacteria in children is a growing concern, particularly among septic patients, given the need for first-right dosing. Our aim was to determine the incidence rates and factors associated with MDR-sepsis in the pediatric intensive care unit (PICU), using data from the Spanish ENVIN-HELICS PICU registry between 2013 and 2019. The rate of MDR bacteria among septic children ranged between 5.8 and 16.2% throughout this study period, with a significant increase since 2015 (p = 0.013). MDR-gram-negative bacteria (92%), particularly EBL-Enterobacterales (63.7%), were the most frequent causative microorganisms of MDR-sepsis. During this study period, sixteen MDR-sepsis (32.6%) corresponded to intrahospital infections, and 33 (67.4%) had community-onset sepsis, accounting for 10.5% of the overall community-onset sepsis. Independent risk factors associated with MDR-sepsis were antibiotics 48 h prior to PICU admission (OR 2.38) and PICU onset of sepsis (OR 2.58) in >1 year-old children, and previous malnourishment (OR 4.99) in <1 year-old children. Conclusions: There was an alarming increase in MDR among septic children in Spain, mainly by gram-negative (ESBL-Enterobacterales), mostly coming from the community setting. Malnourished infants and children on antibiotics 48 h prior to PICU are at increased risk and therefore require closer surveillance

    Proteomic Study of the Interactions between Phages and the Bacterial Host Klebsiella pneumoniae

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    Phages and bacteria have acquired resistance mechanisms for protection. In this context, the aims of the present study were to analyze the proteins isolated from 21 novel lytic phages of Klebsiella pneumoniae in search of defense mechanisms against bacteria and also to determine the infective capacity of the phages. A proteomic study was also conducted to investigate the defense mechanisms of two clinical isolates of K. pneumoniae infected by phages. For this purpose, the 21 lytic phages were sequenced and de novo assembled. The host range was determined in a collection of 47 clinical isolates of K. pneumoniae, revealing the variable infective capacity of the phages. Genome sequencing showed that all of the phages were lytic phages belonging to the order Caudovirales. Phage sequence analysis revealed that the proteins were organized in functional modules within the genome. Although most of the proteins have unknown functions, multiple proteins were associated with defense mechanisms against bacteria, including the restriction-modification system, the toxin-antitoxin system, evasion of DNA degradation, blocking of host restriction and modification, the orphan CRISPR-Cas system, and the anti-CRISPR system. Proteomic study of the phage-host interactions (i.e., between isolates K3574 and K3320, which have intact CRISPR-Cas systems, and phages vB_KpnS-VAC35 and vB_KpnM-VAC36, respectively) revealed the presence of several defense mechanisms against phage infection (prophage, defense/virulence/resistance, oxidative stress and plasmid proteins) in the bacteria, and of the Acr candidate (anti-CRISPR protein) in the phages. IMPORTANCE Researchers, including microbiologists and infectious disease specialists, require more knowledge about the interactions between phages and their bacterial hosts and about their defense mechanisms. In this study, we analyzed the molecular mechanisms of viral and bacterial defense in phages infecting clinical isolates of K. pneumoniae. Viral defense mechanisms included restriction-modification system evasion, the toxin-antitoxin (TA) system, DNA degradation evasion, blocking of host restriction and modification, and resistance to the abortive infection system, anti-CRISPR and CRISPR-Cas systems. Regarding bacterial defense mechanisms, proteomic analysis revealed expression of proteins involved in the prophage (FtsH protease modulator), plasmid (cupin phosphomannose isomerase protein), defense/virulence/resistance (porins, efflux pumps, lipopolysaccharide, pilus elements, quorum network proteins, TA systems, and methyltransferases), oxidative stress mechanisms, and Acr candidates (anti-CRISPR protein). The findings reveal some important molecular mechanisms involved in the phage-host bacterial interactions; however, further study in this field is required to improve the efficacy of phage therapy.This study was funded by grant PI19/00878 and PI22/00323 awarded to M.T. within the State Plan for R1D1I 2013-2016 (National Plan for Scientific Research, Technological Development, and Innovation 2008-2011) and cofinanced by the ISCIII-Deputy General Directorate for Evaluation and Promotion of Research/European Regional Development Fund “A Way of Making Europe” and Instituto de Salud Carlos III FEDER, Spanish Network for the Research in Infectious Diseases (REIPI; RD16/0016/0006 and RD16/0016/0008), CIBERINFEC (CIBER21/13/00012, CB21/13/00049, CIBER21/13/00084, and CIBER21/13/00095), and Personalized Medicine Project (MePRAM; PMP/00092) and also by the Study Group on Mechanisms of Action and Resistance to Antimicrobials, GEMARA (SEIMC; http://www.seimc.org/). M.T. was financially supported by the Miguel Servet Research Program (SERGAS and ISCIII). I.B. was financially supported by pFIS program (ISCIII, FI20/00302). O.P., L.F.-G., and M.L. were financially supported by grants IN606A-2020/035, IN606B-2021/013, and IN606C-2022/002, respectively (GAIN; Xunta de Galicia). The authors acknowledge CESGA (www.cesga.es) in Santiago de Compostela, Spain, for providing access to computing facilities and the RIAIDT-USC analytical facilities. Finally, We thank researchers from the Spanish Network of Bacteriophages and Transducer Elements (FAGOMA) for contributing the lytic phages. I.B., L.B., O.P., and L.F.-G. developed the experiments, analyzed the results, and wrote the original manuscript. M.L., C.O.C. and A.B.P. helped to prepare the visual presentation of the results. F.F.C., Á.P., L.M.-M., and J.O.-I. rewrote the manuscript. M.T. financed and directed the experiments and supervised the writing of the originalmanuscript. We declare that there are no conflicts of interest.S
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