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Search Results: 1 - 10 of 8334 matches for " Jose Yuste "
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Serum Amyloid P Aids Complement-Mediated Immunity to Streptococcus pneumoniae
Jose Yuste,Marina Botto,Stephen E Bottoms,Jeremy S Brown
PLOS Pathogens , 2007, DOI: 10.1371/journal.ppat.0030120
Abstract: The physiological functions of the acute phase protein serum amyloid P (SAP) component are not well defined, although they are likely to be important, as no natural state of SAP deficiency has been reported. We have investigated the role of SAP for innate immunity to the important human pathogen Streptococcus pneumoniae. Using flow cytometry assays, we show that SAP binds to S. pneumoniae, increases classical pathway–dependent deposition of complement on the bacteria, and improves the efficiency of phagocytosis. As a consequence, in mouse models of infection, mice genetically engineered to be SAP-deficient had an impaired early inflammatory response to S. pneumoniae pneumonia and were unable to control bacterial replication, leading to the rapid development of fatal infection. Complement deposition, phagocytosis, and control of S. pneumoniae pneumonia were all improved by complementation with human SAP. These results demonstrate a novel and physiologically significant role for SAP for complement-mediated immunity against an important bacterial pathogen, and provide further evidence for the importance of the classical complement pathway for innate immunity.
Streptococcus pneumoniae: from molecular biology to host-pathogen interactions
Pedro Garcia,Miriam Moscoso,Violeta Rodriguez-Cerrato,Jose Yuste
Journal of Applied Biomedicine , 2010,
Abstract: Streptococcus pneumoniae is the main cause of community acquired pneumonia and also produces meningitis,bacteremia, and otitis media, among others. Worldwide, these infections are the cause of substantial morbidityand mortality. Many different virulence factors have been described and most of them are surface-locatedmacromolecules, namely, the capsular polysaccharide and various pneumococcal proteins. Cell wallhydrolases (CWHs) specifically cleave covalent bonds of the peptidoglycan and associated polymers: mostCWHs are choline-binding proteins (CBPs) and are among the most well-known surface proteins.Pneumococcal CBPs have been investigated due to their role in pathogenesis and as candidate antigens forimproved vaccines. Among the complex host-parasite interactions characteristic of pneumococcal disease,nasopharyngeal colonization is the first step. CBPs appear to play a central role in the development of thecarrier state, possibly by affecting biofilm formation and development. Although the role of biofilms in thepathogenesis of some chronic human infections is currently widely accepted, the molecular bases underlyingthe formation of pneumococcal biofilms are only recently being studied. Among therapeutic strategies tocombat multidrug-resistant pneumococcal infections, the use of purified phage- or bacteria-encoded CWHsboth in vitro and in animal models is under investigation.
Nasopharyngeal Colonization and Invasive Disease Are Enhanced by the Cell Wall Hydrolases LytB and LytC of Streptococcus pneumoniae
Elisa Ramos-Sevillano, Miriam Moscoso, Pedro García, Ernesto García, Jose Yuste
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0023626
Abstract: Background Streptococcus pneumoniae is a common colonizer of the human nasopharynx and one of the major pathogens causing invasive disease worldwide. Dissection of the molecular pathways responsible for colonization, invasion, and evasion of the immune system will provide new targets for antimicrobial or vaccine therapies for this common pathogen. Methodology/Principal Findings We have constructed mutants lacking the pneumococcal cell wall hydrolases (CWHs) LytB and LytC to investigate the role of these proteins in different phases of the pneumococcal pathogenesis. Our results show that LytB and LytC are involved in the attachment of S. pneumoniae to human nasopharyngeal cells both in vitro and in vivo. The interaction of both proteins with phagocytic cells demonstrated that LytB and LytC act in concert avoiding pneumococcal phagocytosis mediated by neutrophils and alveolar macrophages. Furthermore, C3b deposition was increased on the lytC mutant confirming that LytC is involved in complement evasion. As a result, the lytC mutant showed a reduced ability to successfully cause pneumococcal pneumonia and sepsis. Bacterial mutants lacking both LytB and LytC showed a dramatically impaired attachment to nasopharyngeal cells as well as a marked degree of attenuation in a mouse model of colonization. In addition, C3b deposition and phagocytosis was more efficient for the double lytB lytC mutant and its virulence was greatly impaired in both systemic and pulmonary models of infection. Conclusions/Significance This study confirms that the CWHs LytB and LytC of S. pneumoniae are essential virulence factors involved in the colonization of the nasopharynx and in the progress of invasive disease by avoiding host immunity.
Non-O1 Vibrio cholerae inguinal skin and soft tissue infection with bullous skin lesions in a patient with a penis squamous cell carcinoma
Aitziber Aguinaga, María E Portillo, Jose R Yuste, Jose L del Pozo, Emilio García-Tutor, Jose L Pérez-Gracia, José Leiva
Annals of Clinical Microbiology and Antimicrobials , 2009, DOI: 10.1186/1476-0711-8-17
Abstract: Vibrio cholerae is mainly related to water sources [1]. Contaminated seawater exposure or contaminated seafood ingestion are frequently associated with diarrhoea and/or extraintestinal infections such as otitis media, skin and soft tissue infections (SSTI) and bacteremia [1,2]. Vibrio spp. is a pathogen rarely isolated in cancer patients, and in most cases it is associated with haematological diseases. Although the clinical picture may have a wide range in Vibrio spp. SSTI, bullous lesions are almost exclusively associated with V. vulnificus infection [3,4] and have rarely been reported with non-O1 V. cholerae infections [4,5].We report here the case of a non-O1 V. cholerae SSTI presenting bullous skin lesions in a diabetic patient with a solid tumour.A 36-year-old patient from the Canary Islands (Spain) with controlled type II diabetes mellitus was diagnosed with a moderately differentiated squamous cell carcinoma of the penis in December 2006 in his local hospital. The patient underwent a partial penectomy. In the initial follow-up after surgery, the abdominal CT and granulation tissue were normal. The patient had been exposed to seawater and seafood from December 2006 to October 2007 when bullous skin lesions were observed in both inguinal regions during a examination. Lesions were fitted with inguinal metastases, and the patient underwent inguinal surgery followed by radiotherapy.In November 2007 he was admitted to our hospital for a second consultation. Physical examination showed stinking lesions in both inguinal regions with cellulitis and bullae. Patient underwent an abdominal computed tomography (CT) scan with contrast that revealed the existence of several large necrotic adenopathies in the inguinal, scrotal and pubic areas (Figure 1). A right abdominal wall nodule and a left groin abscess extending from psoas muscle to skin were also observed. A CT scan of the chest showed pulmonary lesions compatible with metastases. Initial laboratory findings showed in
Brain Diseases in Mesopotamian Societies
Piedad Yuste
Brain. Broad Research in Artificial Intelligence and Neuroscience , 2010,
Abstract: In ancient Mesopotamia were not practiced neither autopsies nor dissections, so the internal organs of human body were known only from occasional inspections on wounds and injuries. The brain was considered as a part of the head and was not related to mental activity. However, Babylonian and Assyrian physicians were able to identify the symptoms of many diseases that affect this organ. We will make here a brief overview of them.
Circuit neuroscience: the road ahead
Rafael Yuste
Frontiers in Neuroscience , 2008, DOI: 10.3389/neuro.01.017.2008
Abstract: It is difficult to write about grand challenges in our field without pontificating or pretending to show a degree of certainty in assessing the field that I do not possess. I would rather comment on a few of the issues that particularly worry me. Therefore, this article is just a snapshot of our field now, as I see it, and encourage readers to read it as the opinion of just one of their colleagues.
Effects of Streptococcus pneumoniae Strain Background on Complement Resistance
Catherine Hyams, Sophia Opel, William Hanage, Jose Yuste, Katie Bax, Birgitta Henriques-Normark, Brian G. Spratt, Jeremy S. Brown
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0024581
Abstract: Background Immunity to infections caused by Streptococcus pneumoniae is dependent on complement. There are wide variations in sensitivity to complement between S. pneumoniae strains that could affect their ability to cause invasive infections. Although capsular serotype is one important factor causing differences in complement resistance between strains, there is also considerable other genetic variation between S. pneumoniae strains that may affect complement-mediated immunity. We have therefore investigated whether genetically distinct S. pneumoniae strains with the same capsular serotype vary in their sensitivity to complement mediated immunity. Methodology and Principal Findings C3b/iC3b deposition and neutrophil association were measured using flow cytometry assays for S. pneumoniae strains with different genetic backgrounds for each of eight capsular serotypes. For some capsular serotypes there was marked variation in C3b/iC3b deposition between different strains that was independent of capsule thickness and correlated closely to susceptibility to neutrophil association. C3b/iC3b deposition results also correlated weakly with the degree of IgG binding to each strain. However, the binding of C1q (the first component of the classical pathway) correlated more closely with C3b/iC3b deposition, and large differences remained in complement sensitivity between strains with the same capsular serotype in sera in which IgG had been cleaved with IdeS. Conclusions These data demonstrate that bacterial factors independent of the capsule and recognition by IgG have strong effects on the susceptibility of S. pneumoniae to complement, and could therefore potentially account for some of the differences in virulence between strains.
Enhanced In Vivo Activity of Cefditoren in Pre-Immunized Mice against Penicillin-Resistant S. pneumoniae (Serotypes 6B, 19F and 23F) in a Sepsis Model
Fabio Cafini,Jose Yuste,Maria-Jose Giménez,David Sevillano,Lorenzo Aguilar,Luis Alou,Elisa Ramos-Sevillano,Martha Torrico,Natalia González,Ernesto García,Pilar Coronel,Jose Prieto
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0012041
Abstract: Specific antibodies are likely to be present before S. pneumoniae infection. We explored cefditoren (CDN) total and free values of serum concentrations exceeding the MIC (t>MIC) related to efficacy in a mice sepsis model, and the effect of specific gammaglobulins on in-vitro phagocytosis and in-vivo efficacy.
Accuracy of an Immunochromatographic Diagnostic Test (ICT Malaria Combo Cassette Test) Compared to Microscopy among under Five-Year-Old Children when Diagnosing Malaria in Equatorial Guinea
José-Luis Portero,Maria Rubio-Yuste,Miguel Angel Descalzo,Jose Raso,Magdalena Lwanga,Jaquelina Obono,Gloria Nseng,Agustin Benito,Jorge Cano
Malaria Research and Treatment , 2010, DOI: 10.4061/2010/858427
Abstract: Conventional malaria diagnosis based on microscopy raises serious difficulties in weak health systems. Cost-effective and sensitive rapid diagnostic tests have been recently proposed as alternatives to microscopy. In Equatorial Guinea, a study was conducted to assess the reliability of a rapid diagnostic test compared to microscopy. The study was designed in accordance with the directives of the Standards for Reporting Diagnostic Accuracy Initiative (STARD). Peripheral thick and thin films for the microscopy diagnosis and a rapid immunochromatographic test (ICT Malaria Combo Cassette Test) were performed on under five-year-old children with malaria suspicion. The ICT test detected Plasmodium spp. infection with a sensitivity of 81.5% and a specificity of 81.9% while P. falciparum diagnosis occurred with a sensitivity of 69.7% and a specificity of 73.7%. The sensitivity of the ICT test increased with higher parasitemias. The general results showed little concordance between the ICT test and microscopy (kappa = 0.28, se: 0.04). In Equatorial Guinea, the ICT Malaria Combo Cassette Test has proven to be an acceptable test to detect high P. falciparum parasitemias. However, the decrease of sensitivity at medium and low parasitemias hampers that ICT can replace properly performed microscopy at present in the diagnosis of malaria in children. 1. Background The current malaria control strategies are mainly based on early diagnosis and a correct treatment of the cases. These are essential to reduce the fatal outcome of the disease [1]. However, the weakness of the health systems in many endemic countries, particularly at the peripheral level, means that the malaria diagnosis has to be based on clinical criteria. Taking into account that other infectious diseases course with signs and symptoms like malaria, a high percentage of overdiagnosis can be expected in a tropical area [2–4]. The growing resistance to drugs commonly used for malaria treatment (chloroquine, quinine, and sulphadoxine-pyrimethamine), due to their abusive use in the past, and the arrival of artemisinin-based combination therapies (ACTs), which are more expensive than the former, mean that the methods to diagnose malaria are once again back in the spotlight. Microscopy and the use of rapid diagnostic tests (RDTs) are currently considered to be the two diagnostic procedures with the greatest impact on controlling malaria [5]. Microscopy can be a highly useful diagnostic tool, as in expert hands it can detect up to 50 parasites per l (0.001% parasitemia) and identify the plasmodia in 98% of the
Wireless Intelligent Sensors Management Application Protocol-WISMAP
Juan Carlos Cuevas-Martinez,Manuel Angel Gadeo-Martos,Jose Angel Fernandez-Prieto,Joaquin Canada-Bago,Antonio Jesus Yuste-Delgado
Sensors , 2010, DOI: 10.3390/s101008827
Abstract: Although many recent studies have focused on the development of new applications for wireless sensor networks, less attention has been paid to knowledge-based sensor nodes. The objective of this work is the development in a real network of a new distributed system in which every sensor node can execute a set of applications, such as fuzzy ruled-base systems, measures, and actions. The sensor software is based on a multi-agent structure that is composed of three components: management, application control, and communication agents; a service interface, which provides applications the abstraction of sensor hardware and other components; and an application layer protocol. The results show the effectiveness of the communication protocol and that the proposed system is suitable for a wide range of applications. As real world applications, this work presents an example of a fuzzy rule-based system and a noise pollution monitoring application that obtains a fuzzy noise indicator.
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