489 research outputs found

    Characterization of Oral Enterobacteriaceae Prevalence and Resistance Profile in Chronic Kidney Disease Patients Undergoing Peritoneal Dialysis

    Get PDF
    Chronic Kidney Disease (CKD) is a growing public-health concern worldwide. Patients exhibit compromised immunity and are more prone to infection than other populations. Therefore, oral colonization by clinically relevant members of the Enterobacteriaceae family, major agents of both nosocomial and dialysis-associated infections with frequent prevalence of antibiotic resistances, may constitute a serious risk. Thus, this study aimed to assess the occurrence of clinically relevant enterobacteria and their antibiotic resistance profiles in the oral cavity of CKD patients undergoing peritoneal dialysis (CKD-PD) and compare it to healthy controls. Saliva samples from all the participants were cultured on MacConkey Agar and evaluated regarding the levels of urea, ammonia, and pH. Bacterial isolates were identified and characterized for antibiotic resistance phenotype and genotype. The results showed that CKD-PD patients exhibited significantly higher salivary pH, urea, and ammonia levels than controls, that was accompanied by higher prevalence and diversity of oral enterobacteria. Out of all the species isolated, only the prevalence of Raoultella ornithinolytica varied significantly between groups, colonizing the oral cavity of approximately 30% of CKD-PD patients while absent from controls. Antibiotic resistance phenotyping revealed mostly putative intrinsic resistance phenotypes (to amoxicillin, ticarcillin, and cephalothin), and resistance to sulfamethoxazole (~43% of isolates) and streptomycin (~17%). However, all isolates were resistant to at least one of the antibiotics tested and multidrug resistance isolates were only found in CKD-PD group (31,6%). Mobile genetic elements and resistance genes were detected in isolates of the species Raoultella ornithinolytica, Klebsiella pneumoniae, Klebsiella oxytoca, Escherichia coli, and Enterobacter asburiae, mostly originated from CKD-PD patients. PD-related infection history revealed that Enterobacteriaceae were responsible for ~8% of peritonitis and ~ 16% of exit-site infections episodes in CKD-PD patients, although no association was found to oral enterobacteria colonization at the time of sampling. The results suggest that the CKD-induced alterations of the oral milieu might promote a dysbiosis of the commensal oral microbiome, namely the proliferation of clinically relevant Enterobacteriaceae potentially harboring acquired antibiotic resistance genes. This study highlights the importance of the oral cavity as a reservoir for pathobionts and antibiotic resistances in CKD patients undergoing peritoneal dialysis.This work is a result of the project POCI-01-0145-FEDER-029777, co-financed by Competitiveness and Internationalisation Operational Programme (POCI), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF) and through national funds by the FCT – Fundação para a Ciência e a Tecnologia. CC fellowship was supported by FCT/MCTES scholarship with the reference 2020.08540.BD. This work and CF were financially supported by FEDER through project “Assessing the risks associated with environmental antibiotic resistant bacteria: propagation and transmission to humans” (PTDC/CTA-AMB/28196/2017) – Programa Operacional Competitividade e Internacionalização, and by National Funds from FCT – Fundação para a Ciência e a Tecnologia and was hosted by CBQF through FCT project UIDB/50016/2020

    Repurposing of tamoxifen ameliorates CLN3 and CLN7 disease phenotype

    Get PDF
    Batten diseases (BDs) are a group of lysosomal storage disorders characterized by seizure, visual loss, and cognitive and motor deterioration. We discovered increased levels of globotriaosylceramide (Gb3) in cellular and murine models of CLN3 and CLN7 diseases and used fluorescent-conjugated bacterial toxins to label Gb3 to develop a cell-based high content imaging (HCI) screening assay for the repurposing of FDA-approved compounds able to reduce this accumulation within BD cells. We found that tamoxifen reduced the lysosomal accumulation of Gb3 in CLN3 and CLN7 cell models, including neuronal progenitor cells (NPCs) from CLN7 patient-derived induced pluripotent stem cells (iPSC). Here, tamoxifen exerts its action through a mechanism that involves activation of the transcription factor EB (TFEB), a master gene of lysosomal function and autophagy. In vivo administration of tamoxifen to the CLN7Δex2 mouse model reduced the accumulation of Gb3 and SCMAS, decreased neuroinflammation, and improved motor coordination. These data strongly suggest that tamoxifen may be a suitable drug to treat some types of Batten disease

    Membranes by the Numbers

    Get PDF
    Many of the most important processes in cells take place on and across membranes. With the rise of an impressive array of powerful quantitative methods for characterizing these membranes, it is an opportune time to reflect on the structure and function of membranes from the point of view of biological numeracy. To that end, in this article, I review the quantitative parameters that characterize the mechanical, electrical and transport properties of membranes and carry out a number of corresponding order of magnitude estimates that help us understand the values of those parameters.Comment: 27 pages, 12 figure

    Participation of Candida albicans transcription factor Rlm1 in cell wall biogenesis and virulence

    Get PDF
    Candida albicans cell wall is important for growth and interaction with the environment. RLM1 is one of the putative transcription factors involved in the cell wall integrity pathway, which plays an important role in the maintenance of the cell wall integrity. In this work we investigated the involvement of RLM1 in the cell wall biogenesis and in virulence. Newly constructed C. albicans Δ/Δrlm1 mutants showed typical cell wall weakening phenotypes, such as hypersensitivity to Congo Red, Calcofluor White, and caspofungin (phenotype reverted in the presence of sorbitol), confirming the involvement of RLM1 in the cell wall integrity. Additionally, the cell wall of C. albicans Δ/Δrlm1 showed a significant increase in chitin (213%) and reduction in mannans (60%), in comparison with the wild-type, results that are consistent with cell wall remodelling. Microarray analysis in the absence of any stress showed that deletion of RLM1 in C. albicans significantly down-regulated genes involved in carbohydrate catabolism such as DAK2, GLK4, NHT1 and TPS1, up-regulated genes involved in the utilization of alternative carbon sources, like AGP2, SOU1, SAP6, CIT1 or GAL4, and genes involved in cell adhesion like ECE1, ALS1, ALS3, HWP1 or RBT1. In agreement with the microarray results adhesion assays showed an increased amount of adhering cells and total biomass in the mutant strain, in comparison with the wild-type. C. albicans mutant Δ/Δrlm1 strain was also found to be less virulent than the wild-type and complemented strains in the murine model of disseminated candidiasis. Overall, we showed that in the absence of RLM1 the modifications in the cell wall composition alter yeast interaction with the environment, with consequences in adhesion ability and virulence. The gene expression findings suggest that this gene participates in the cell wall biogenesis, with the mutant rearranging its metabolic pathways to allow the use of alternative carbon sources.This work was supported by CBMA (Centre of Molecular and Environmental Biology) through the FCT (Fundacao para a Ciencia e Tecnologia) project PEst-C/BIA/UI4050/2011. Yolanda Delgado-Silva was supported by an ALbAN scholarship (No E07D400922PE), and Alexandra Correia by SFRH/BD/31354/2006 fellowship. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

    Plantando, colhendo, vendendo, mas não comendo: práticas alimentares e de trabalho associadas à obesidade em agricultores familiares do Bonfim, Petrópolis, RJ.

    Get PDF
    Objetivo: verificar a prevalência de obesidade entre adultos das 86 famílias agricultoras de um bairro de Petrópolis, RJ, e analisar seus determinantes socioculturais. Métodos: estudo quantitativo e qualitativo sobre nutrição, práticas alimentares e de trabalho realizado em 2008. Dados antropométricos foram coletados por inquérito nutricional domiciliar e o material qualitativo por observação participante e entrevistas. Resultados: a prevalência de obesidade foi baixa (9,3%) entre os homens, mas bastante elevada entre as mulheres (29,9%). A prática agrícola local implica em atividade física leve para mulheres e intensa para homens. Essa diferença não é acompanhada na dieta, semelhante para homens e mulheres, com predomínio de alimentos de alto valor calórico. A produção familiar objetiva essencialmente a venda. A agricultura mercantil e a decorrente especialização dos cultivos favorecem comprar alimentos no mercado em vez de produzir para autoconsumo. Conclusão: os aspectos socioculturais e ocupacionais estudados podem ter contribuído para elevar a prevalência de obesidade nas mulheres e podem ser úteis no estudo de outros grupos com características semelhantes. Esta pesquisa ratifica a importância de estudar a obesidade em nível local, integrando abordagens quantitativas e qualitativas para identificar possíveis limitações e portas de entrada para ações de intervenção localmente relevantes

    Fuzzy Free Path Detection from Disparity Maps by Using Least-Squares Fitting to a Plane

    Full text link
    A method to detect obstacle-free paths in real-time which works as part of a cognitive navigation aid system for visually impaired people is proposed. It is based on the analysis of disparity maps obtained from a stereo vision system which is carried by the blind user. The presented detection method consists of a fuzzy logic system that assigns a certainty to be part of a free path to each group of pixels, depending on the parameters of a planar-model fitting. We also present experimental results on different real outdoor scenarios showing that our method is the most reliable in the sense that it minimizes the false positives rate.N. Ortigosa acknowledges the support of Universidad Politecnica de Valencia under grant FPI-UPV 2008 and Spanish Ministry of Science and Innovation under grant MTM2010-15200. S. Morillas acknowledges the support of Universidad Politecnica de Valencia under grant PAID-05-12-SP20120696.Ortigosa Araque, N.; Morillas Gómez, S. (2014). Fuzzy Free Path Detection from Disparity Maps by Using Least-Squares Fitting to a Plane. Journal of Intelligent and Robotic Systems. 75(2):313-330. https://doi.org/10.1007/s10846-013-9997-1S313330752Cai, L., He, L., Xu, Y., Zhao, Y., Yang, X.: Multi-object detection and tracking by stereovision. Pattern Recognit. 43(12), 4028–4041 (2010)Hikosaka, N., Watanabe, K., Umeda, K.: Obstacle detection of a humanoid on a plane using a relative disparity map obtained by a small range image sensor. In: Proceedings of the IEEE International Conference on Robotics and Automation, vol. 1, pp. 3048–3053 (2007)Benenson, R., Mathias, M., Timofte, R., Van Gool, L.: Fast stixel computation for fast pedestrian detection. In: ECCV, CVVT workshop, October (2012)Huang, Y., Fu, S., Thompson, C.: Stereovision-based object segmentation for automotive applications. EURASIP J. Appl. Signal Process. 2005(14), 2322–2329 (2005)Duan, B.B., Liu, W., Fu, P.Y., Yang, C.Y., Wen, X.Z., Yuan, H.: Real-time on-road vehicle and motorcycle detection using a single camera. In: IEEE International Conference on Industrial Technology, pp. 579–584. IEEE (2009)Oliveira L, Nunes, U.: On integration of features and classifiers for robust vehicle detection. In: IEEE International Conference on Intelligent Transportation Systems, pp. 414–419. IEEE (2008)Sun, Z., Bebis, G., Miller, R.: On-road vehicle detection: A review. IEEE Trans. Pattern Anal. Mach. Intell. 28(5), 694–711 (2006)Sun, H.J., Yang, J.Y.: Obstacle detection for mobile vehicle using neural network and fuzzy logic. Neural Netw. Distrib. Process. 4555(1), 99–104 (2001)Hui, N.B., Pratihar, D.K.: Soft computing-based navigation schemes for a real wheeled robot moving among static obstacles. J. Intell. Robot. Syst. 51(3), 333–368 (2008)Menon, A., Akmeliawati, R., Demidenko, S.: Towards a simple mobile robot with obstacle avoidance and target seeking capabilities using fuzzy logic. In: Proceedings IEEE Instrumentation and Measurement Technology Conference, vol. 1–5, pp. 1003–1008 (2008)Moreno-Garcia, J., Rodriguez-Benitez, L., Fernandez-Caballero, A., Lopez, M.T.: Video sequence motion tracking by fuzzification techniques. Appl. Soft Comput. 10(1), 318–331 (2010)Nguyen, T.H., Nguyen, J.S., Pham, D.M., Nguyen, H.T.: Real-time obstacle detection for an autonomous wheelchair using stereoscopic cameras. Conf. Proc. IEEE Eng. Med. Biol. Soc. 2007(1), 4775–4778 (2007)Nguyen, J.S., Nguyen, T.H., Nguyen, H.T.: Semi-autonomous wheelchair system using stereoscopic cameras. In: Annual International Conference of the IEEE Engineering in Medicine and Biology Society, vol. 1–20, pp. 5068–5071 (2009)Grosso, E., Tistarelli, M.: Active/dynamic stereo vision. IEEE Trans. Pattern Anal. Mach. Intell. 17(9), 868–879 (1995)Kubota, S., Nakano, T., Okamoto, Y.: A global optimization for real-time on-board stereo obstacle detection systems. In: IEEE Intelligent Vehicles Symposium, pp. 7–12. IEEE (2007)Ortigosa, N., Morillas, S., Peris-Fajarnés, G., Dunai, L.: Fuzzy free path detection based on dense disparity maps obtained from stereo cameras. Int. J. Uncertain. Fuzziness Knowl.-Based Syst. 20(2), 245–259 (2012)Murray, D., Little, J.J.: Using real-time stereo vision for mobile robot navigation. Auton. Robot. 8(2), 161–171 (2000)Badino, H., Mester, R., Vaudrey, T., Franke, U.: Stereo-based free space computation in complex traffic scenarios. In: IEEE Southwest Symposium on Image Analysis & Interpretation, pp. 189–192 (2008)Hoilund, C., Moeslund, T.B., Madsen, C.L., Trivedi, M.M.: Free space computation from stochastic occupancy grids based on iconic kalman filtered disparity maps. In: Proceedings International Conference on Computer Vision Theory and Applications, vol. 1, pp. 164–167 (2010)Franke, U., Joos, A.: Real-time stereo vision for urban traffic scene understanding. In: IEEE Intelligent Vehicles Symposium, pp. 273–278. IEEE (2000)Wedel, A., Badino, H., Rabe, C., Loose, H., Franke, U., Cremers, D.: B-spline modeling of road surfaces with an application to free-space estimation. IEEE Trans. Intell. Transp. Syst. 10(4), 572–583 (2009)Vergauwen, M., Pollefeys, M., Van Gool, L.: A stereo-vision system for support of planetary surface exploration. Mach. Vis. Appl. 14(1), 5–14 (2003)Tarel, J.P., Leng, S.S., Charbonnier, P.: Accurate and robust image alignment for road profile reconstruction. In: IEEE International Conference on Image Processing, pp. 365–368. IEEE (2007)Kostavelis, I., Gasteratos, A.: Stereovision-based algorithm for obstacle avoidance. In: Lecture Notes in Computer Science, pp. 195–204. Intelligent Robotics and Applications (2009)Cerri, P., Grisleri, P.: Free space detection on highways using time correlation between stabilized sub-pixel precision ipm images. In: IEEE International Conference on Robotics and Automation, pp. 2223–2228. IEEE (2005)Labayrade, R., Aubert, D., Tarel, J.P.: Real time obstacle detection in stereo vision on non-flat road geometry through v-disparity representation. In: IEEE Intelligent Vehicle Symposium, pp. 646–651. INRIA (2002)Ortigosa, N., Morillas, S., Peris-Fajarnés, G., Dunai, L.: Disparity maps for free path detection. In: Proceedings International Conference on Computer Vision Theory and Applications, vol. 1, pp. 310–315 (2010)Ortigosa, N., Morillas, S., Peris-Fajarnés, G.: Obstacle-free pathway detection by means of depth maps. J. Intell. Robot. Syst. 63(1), 115–129 (2011)http://www.casblip.comBach y Rita, P., Collins, C., Sauders, B., White, B., Scadden, L.: Vision substitution by tactile image projection. Nature 221, 963964 (1969)Sampaio, E., Maris, S., Bach y Rita, P.: Brain plasticity: visual acuity of blind persons via the tongue. Brain Res. 908, 204207 (2001)http://www.seeingwithsound.comCapelle, C., Trullemans, C., Arno, P., Veraart, C.: A real-time experimental prototype for enhancement of vision rehabilitation using auditory substitution. IEEE Trans. Biomed. Eng. 45, 12791293 (1998)Lee, S.W., Kang, S.K., Lee, S.A.: A walking guidance system for the visually impaired. Int. J. Pattern Recognit. 22, 11711186 (2008)Chen, C.L., Liao, Y.F., Tai, C.L.: Image-to-midi mapping based on dynamic fuzzy color segmentation for visually impaired people. Pattern Recognit. Lett. 32, 549–560 (2011)Lombardi, P., Zanin, M., Messelodi, S.: Unified stereovision for ground, road, and obstacle detection. In: Proceedings on the Intelligent Vehicles Symposium, 2005, pp. 783–788. IEEE (2005)Yu, Q., Araujo, H., Wang, H.: Stereo-vision based real time obstacle detection for urban environments. In: Proceedings on the International Conference of Advanced Robotics, vol. 1, pp. 1671–1676 (2003)Benenson, R., Timofte, R., Van Gool, L.: Stixels estimation without depth map computation. In: ICCV, CVVT workshop (2011)Li, X., Yao, X., Murphey, Y.L., Karlsen, R., Gerhart, G.: A real-time vehicle detection and tracking system in outdoor traffic scenes. In: Pattern Recognition, 2004. ICPR 2004. Proceedings of the 17th International Conference on, vol. 2, pp. 761–764 (2004)Zhang, Z.Y.: A flexible new technique for camera calibration. IEEE Trans. Pattern Anal. Mach. Intell. 22(11), 1330–1334 (2000)Dhond, U.R., Aggarwal, J.K.: Structure from stereo: a review. IEEE Trans. Syst. Man Cybern. 19, 1489–1510 (1989)Scharstein, D., Szeliski, R.: A taxonomy and evaluation of dense two-frame stereo correspondence algorithms. Int. J. Comput. Vis. 47(1/2/3), 7–42 (2002)Middlebury Stereo Vision Page. http://vision.middlebury.edu/stereo/Birchfield, S., Tomasi, C.: Depth discontinuities by pixel-to-pixel stereo. Int. J. Comput. Vis. 17(3), 269–293 (1999)Lawrence Zitnick, C., Bing Kang, S.: Stereo for image-based rendering using image over-segmentation. Int. J. Comput. Vis. 75(1), 49–65 (2007)Felzenszwalb, P.F., Huttenlocher, D.P.: Efficient belief propagation for early vision. Int. J. Comput. Vis. 70(1), 41–54 (2006)Yang, Q., Wang, L., Yang, R., Stewnius, H., Nistr, D.: Stereo matching with color-weighted correlation, hierarchical belief propagation, and occlusion handling. IEEE Trans. Pattern Anal. Mach. Intell. 31(3), 492–504 (2009)Gehrig, S., Eberli, F., Meyer, T.: A real-time low-power stereo vision engine using semi-global matching. Lect. Notes Comput. Sci. 5815/2009, 134–143 (2009)Wedel, A., Brox, T., Vaudrey, T., Rabe, C., Franke, U., Cremers, D.: Stereoscopic scene flow computation for 3d motion understanding. Int. J. Comput. Vis. 95, 29–51 (2011)Hirschmuller, H.: Stereo processing by semiglobal matching and mutual information. IEEE Trans. Pattern Anal. Mach. Intell. 30(2), 328–341 (2008)Leung, C., Appleton, B., Sun, C.: Iterated dynamic programming and quadtree subregioning for fast stereo matching. Image Vis. Comput. 26(10), 1371–1383 (2008)Hartley, R.I., Zisserman, A.: Multiple view geometry in computer vision, 2nd edn. Cambridge University Press, ISBN: 0521540518 (2004)Spiegel, M.R., Stepthens, L.J.: Statistics, 4th edn. Mc Graw Hill (2008)Kerre, E.E.: Fuzzy sets and approximate reasoning. Xian Jiaotong University Press (1998)Dubois, D., Prade, H.: Fuzzy sets and systems: theory and applications. Academic Press, New York (1980)Lee, C.C.: Fuzzy logic in control systems: Fuzzy logic controller-parts 1 and 2. IEEE Trans. Syst. Man Cybern. 20(2), 404–435 (1990)Fodor, J.C.: A new look at fuzzy-connectives. Fuzzy Sets Syst. 57(2), 141–148 (1993)Nalpantidis, L., Gasteratos, A.: Stereo vision for robotic applications in the presence of non-ideal lightning conditions. Image Vis. Comput. 28(6), 940–951 (2010

    Performance of the CMS Cathode Strip Chambers with Cosmic Rays

    Get PDF
    The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns
    corecore