54 research outputs found

    Characterisation of Shiga toxin-producing Escherichia coli O157 strains isolated from humans in Argentina, Australia and New Zealand

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    Background: Shiga toxin-producing Escherichia coli (STEC) is an important cause of bloody diarrhoea (BD), non-bloody diarrhoea (NBD) and the haemolytic uraemic syndrome (HUS). In Argentina and New Zealand, the most prevalent STEC serotype is O157:H7, which is responsible for the majority of HUS cases. In Australia, on the other hand, STEC O157:H7 is associated with a minority of HUS cases. The main aims of this study were to compare the phenotypic and genotypic characteristics of STEC O157 strains isolated between 1993 and 1996 from humans in Argentina, Australia and New Zealand, and to establish their clonal relatedness. Results: Seventy-three O157 STEC strains, isolated from HUS (n = 36), BD (n = 20), NBD (n = 10), or unspecified conditions (n = 7) in Argentina, Australia and New Zealand, were analysed. The strains were confirmed to be E. coli O157 by biochemical tests and serotyping. A multiplex polymerase chain reaction (PCR) was used to amplify the stx1, stx2 and rfbO157 genes and a genotyping method based on PCR-RFLP was used to determine stx1 and stx2 variants. This analysis revealed that the most frequent stx genotypes were stx2/stx 2c (vh-a) (91%) in Argentina, stx2 (89%) in New Zealand, and stx1/stx2 (30%) in Australia. No stx 1-postive strains were identified in Argentina or New Zealand. All strains harboured the eae gene and 72 strains produced enterohaemolysin (EHEC-Hly). The clonal relatedness of strains was investigated by phage typing and pulsed-field gel electrophoresis (PFGE). The most frequent phage types (PT) identified in Argentinian, Australian, and New Zealand strains were PT49 (n = 12), PT14 (n = 9), and PT2 (n = 15), respectively. Forty-six different patterns were obtained by XbaI-PFGE; 37 strains were grouped in 10 clusters and 36 strains showed unique patterns. Most clusters could be further subdivided by BlnI-PFGE. Conclusion: STEC O157 strains isolated in Argentina, Australia, and New Zealand differed from each other in terms of stx-genotype and phage type. Additionally, no common PFGE patterns were found in strains isolated in the three countries. International collaborative studies of the type reported here are needed to detect and monitor potentially hypervirulent STEC clones.Fil: Leotta, Gerardo Anibal. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud “Dr. C. G. Malbrán”; ArgentinaFil: Miliwebsky, Elizabeth S.. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud “Dr. C. G. Malbrán”; ArgentinaFil: Chinen, Isabel. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud “Dr. C. G. Malbrán”; ArgentinaFil: Espinosa, Estela M.. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud “Dr. C. G. Malbrán”; ArgentinaFil: Azzopardi, Kristy. University of Melbourne; AustraliaFil: Tennant, Sharon M.. University of Melbourne; AustraliaFil: Robins Browne, Roy M.. University of Melbourne; AustraliaFil: Rivas, Marta. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud “Dr. C. G. Malbrán”; Argentin

    Manejo del angioedema severo mediante concentrado del inhibidor de C1 A propósito de un caso tras anestesia general

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    El angioedema, también conocido como edema angioneurótico o de Quincke es una enfermedad hereditaria infrecuente transmitida con patrón autosómico dominante. Se caracteriza clínicamente por episodios recurrentes de angioedema sin urticaria debido a un defecto de la enzima Inhibidor de C1 (C1-INH), glicoproteína perteneciente a la superfamilia de las serpinas, sintetizada fundamentalmente en el hígado con acción inhibitoria sobre el sistema del complemento, coagulación, fibrinólisis y sistema de contacto. El déficit de C1-INH activa incontroladamente la vía clásica del complemento, mediado entre otras por la bradicidina (producto del sistema de contacto) como principal mediador vasoactivo involucrado en la aparición del angioedema. Se clasifica en Angioedema tipo I (85%): caracterizado por síntesis disminuida de C1-INH y el Angioedema tipo II (15%): síntesis normal de C1-INH pero ineficaz funcionalmente. Los niveles de C4 estarían disminuidos en ambos tipos. El edema subepitelial no pruriginoso de predominio en cara, extremidades y abdomen es el síntoma fundamental, siendo la afectación laríngea con compromiso de vía aérea la manifestación más grave. Los ataques agudos pueden ser precipitados por diversos desencadenantes, entre ellos destacan los procedimientos quirúrgicos, el trauma físico, estrés emocional y algunos fármacos (por ejemplo IECAs, anticonceptivos con estrógenos o terapia hormonal sustitutiva)

    Manejo del angioedema severo mediante concentrado del inhibidor de C1 A propósito de un caso tras anestesia general

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    El angioedema, también conocido como edema angioneurótico o de Quincke es una enfermedad hereditaria infrecuente transmitida con patrón autosómico dominante. Se caracteriza clínicamente por episodios recurrentes de angioedema sin urticaria debido a un defecto de la enzima Inhibidor de C1 (C1-INH), glicoproteína perteneciente a la superfamilia de las serpinas, sintetizada fundamentalmente en el hígado con acción inhibitoria sobre el sistema del complemento, coagulación, fibrinólisis y sistema de contacto. El déficit de C1-INH activa incontroladamente la vía clásica del complemento, mediado entre otras por la bradicidina (producto del sistema de contacto) como principal mediador vasoactivo involucrado en la aparición del angioedema. Se clasifica en Angioedema tipo I (85%): caracterizado por síntesis disminuida de C1-INH y el Angioedema tipo II (15%): síntesis normal de C1-INH pero ineficaz funcionalmente. Los niveles de C4 estarían disminuidos en ambos tipos. El edema subepitelial no pruriginoso de predominio en cara, extremidades y abdomen es el síntoma fundamental, siendo la afectación laríngea con compromiso de vía aérea la manifestación más grave. Los ataques agudos pueden ser precipitados por diversos desencadenantes, entre ellos destacan los procedimientos quirúrgicos, el trauma físico, estrés emocional y algunos fármacos (por ejemplo IECAs, anticonceptivos con estrógenos o terapia hormonal sustitutiva)

    Expression, regulation and clinical relevance of the ATPase Inhibitory Factor 1 (IF1) in human cancers

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    Recent findings in colon cancer cells indicate that inhibition of the mitochondrial H(+)-adenosine triphosphate (ATP) synthase by the ATPase inhibitory factor 1 (IF1) promotes aerobic glycolysis and a reactive oxygen species (ROS)-mediated signal that enhances proliferation and cell survival. Herein, we have studied the expression, biological relevance, mechanism of regulation and potential clinical impact of IF1 in some prevalent human carcinomas. We show that IF1 is highly overexpressed in most (>90%) of the colon (n=64), lung (n=30), breast (n=129) and ovarian (n=10) carcinomas studied as assessed by different approaches in independent cohorts of cancer patients. The expression of IF1 in the corresponding normal tissues is negligible. By contrast, the endometrium, stomach and kidney show high expression of IF1 in the normal tissue revealing subtle differences by carcinogenesis. The overexpression of IF1 also promotes the activation of aerobic glycolysis and a concurrent ROS signal in mitochondria of the lung, breast and ovarian cancer cells mimicking the activity of oligomycin. IF1-mediated ROS signaling activates cell-type specific adaptive responses aimed at preventing death in these cell lines. Remarkably, regulation of IF1 expression in the colon, lung, breast and ovarian carcinomas is exerted at post-transcriptional levels. We demonstrate that IF1 is a short-lived protein (t(1/2) ∼100 min) strongly implicating translation and/or protein stabilization as main drivers of metabolic reprogramming and cell survival in these human cancers. Analysis of tumor expression of IF1 in cohorts of breast and colon cancer patients revealed its relevance as a predictive marker for clinical outcome, emphasizing the high potential of IF1 as therapeutic target

    Waist circumference percentiles for Hispanic-American children and comparison with other international references

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    Introduction Waist circumference (WC) constitutes an indirect measurement of central obesity in children and adolescents. Objective To provide percentiles of WC for Hispanic-American children and adolescents, and compare them with other international references. Materials and methods The sample comprised 13 289 healthy children between 6 and 18 years coming from public schools of middle and low socioeconomic levels in different parts of Argentina, Cuba, Spain, Mexico, and Venezuela. The LMS method to calculate WC percentiles was applied. Sex and age differences were assessed using Student'sttest and ANOVA (SPSS v.21.0). Comparisons were established with references from the United States, Colombia, India, China, Australia, Kuwait, Germany, Tunisia, Greece, and Portugal. Results WC increases with age in both sexes. Boys show higher WC in P3, P50, and P97. Comparison of 50th and 90th percentiles among populations from diverse sociocultural and geographical contexts shows high variability, not all justified by the measurement method. Discussion and conclusions Specific WC percentiles for sex and age, and P90 cut-off points are provided; these values are potentially useful to assess central obesity in Hispanic-American adolescent children

    Desde la transferencia universitaria hacia la gestión municipal

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    Las profundas y aceleradas transformaciones generan modelos distintos de organización territorial que requieren, por un lado del conocimiento científico y de la valoración del ambiente, y por otro saber actuar en el contexto de las realidades locales y regionales, modificando las formas de accionar de los municipios ante necesidades específicas. El Atlas Digital del Partido de Balcarce (Tomas et al, 2004), surgió a partir de un Proyecto de Extensión del Área de Cartografía del Centro de Geología de Costas y del Cuaternario (C.G.C. y C.). Unidad de investigación, dependiente de la Facultad de Ciencias Exactas y Naturales de la Universidad Nacional de Mar del Plata, Argentina. En el año 2003 se firmó el CONTRATO DE ASESORAMIENTO Y ASISTENCIA TÉCNICA entre la Facultad de Ciencias Exactas y Naturales de la Universidad Nacional de Mar del Plata y la Municipalidad del Partido de Balcarce para la realización del Atlas Digital. El Atlas Digital del Partido de Balcarce ha sido desarrollado por un equipo de trabajo multidisciplinario, integrado por profesionales dedicados a la temática respectiva. Es una obra digital realizada con modernos recursos de captura y administración de la información espacial, obtenida de las fuentes de datos provinciales y nacionales más confiables.Fil: Tomas, Mónica. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Farenga, M. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales; Argentina.Fil: Martínez, Gustavo. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exáctas y Naturales; Argentina.Fil: Massone, H. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales; Argentina.Fil: Cabria, F. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Dillon, G. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Calandroni, M. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Mazzanti, D. Universidad Nacional de Mar del Plata. Facultad de Humanidades; Argentina.Fil: Pastoriza, Elisa. Universidad Nacional de Mar del Plata. Facultad de Humanidades; Argentina.Fil: Pilcic, T. Universidad Nacional de Mar del Plata. Facultad de Humanidades; Argentina.Fil: Lanari, María Estela. Universidad Nacional de Mar del Plata. Facultad de Ciencias Económicas y Sociales; Argentina.Fil: López, María Teresa. Universidad Nacional de Mar del Plata. Facultad de Ciencias Económicas y Sociales; Argentina.Fil: López, J. Universidad Nacional de Mar del Plata. Departamento de Televisión; Argentina.Fil: Salgado, P. Universidad Nacional de Mar del Plata. Departamento de Televisión; Argentina

    Vaccine breakthrough hypoxemic COVID-19 pneumonia in patients with auto-Abs neutralizing type I IFNs

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    Life-threatening `breakthrough' cases of critical COVID-19 are attributed to poor or waning antibody response to the SARS- CoV-2 vaccine in individuals already at risk. Pre-existing autoantibodies (auto-Abs) neutralizing type I IFNs underlie at least 15% of critical COVID-19 pneumonia cases in unvaccinated individuals; however, their contribution to hypoxemic breakthrough cases in vaccinated people remains unknown. Here, we studied a cohort of 48 individuals ( age 20-86 years) who received 2 doses of an mRNA vaccine and developed a breakthrough infection with hypoxemic COVID-19 pneumonia 2 weeks to 4 months later. Antibody levels to the vaccine, neutralization of the virus, and auto- Abs to type I IFNs were measured in the plasma. Forty-two individuals had no known deficiency of B cell immunity and a normal antibody response to the vaccine. Among them, ten (24%) had auto-Abs neutralizing type I IFNs (aged 43-86 years). Eight of these ten patients had auto-Abs neutralizing both IFN-a2 and IFN-., while two neutralized IFN-omega only. No patient neutralized IFN-ss. Seven neutralized 10 ng/mL of type I IFNs, and three 100 pg/mL only. Seven patients neutralized SARS-CoV-2 D614G and the Delta variant (B.1.617.2) efficiently, while one patient neutralized Delta slightly less efficiently. Two of the three patients neutralizing only 100 pg/mL of type I IFNs neutralized both D61G and Delta less efficiently. Despite two mRNA vaccine inoculations and the presence of circulating antibodies capable of neutralizing SARS-CoV-2, auto-Abs neutralizing type I IFNs may underlie a significant proportion of hypoxemic COVID-19 pneumonia cases, highlighting the importance of this particularly vulnerable population

    Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

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    The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

    Global urban environmental change drives adaptation in white clover

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    Urbanization transforms environments in ways that alter biological evolution. We examined whether urban environmental change drives parallel evolution by sampling 110,019 white clover plants from 6169 populations in 160 cities globally. Plants were assayed for a Mendelian antiherbivore defense that also affects tolerance to abiotic stressors. Urban-rural gradients were associated with the evolution of clines in defense in 47% of cities throughout the world. Variation in the strength of clines was explained by environmental changes in drought stress and vegetation cover that varied among cities. Sequencing 2074 genomes from 26 cities revealed that the evolution of urban-rural clines was best explained by adaptive evolution, but the degree of parallel adaptation varied among cities. Our results demonstrate that urbanization leads to adaptation at a global scale

    Atlas digital del Partido de Balcarce Provincia de Buenos Aires, República Argentina

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    El "Atlas Digital del Partido de Balcarce", es un producto digital desarrollado por un equipo multidisciplinario conformado por especialistas en distintas ramas de la ciencia y la tecnología. El contenido del Atlas dividido en distintos niveles temáticos, describe las características físicas, históricas, económicas, demográficas y socioculturales; proporcionando un marco geográfico y territorial de la realidad socioeconómica del Partido de Balcarce, Provincia de Buenos Aires, República Argentina.Fil: Tomas, Mónica. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales; Argentina.Fil: Farenga, M. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales; Argentina.Fil: Bernasconi, M. V. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales; Argentina.Fil: Martínez, G. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales; Argentina.Fil: Massone, H. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales; Argentina.Fil: Cabria, F. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Calandroni, M. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Dillon, G. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Mazzanti, D. Universidad Nacional de Mar del Plata. Facultad de Humanidades; Argentina.Fil: Pastoriza, Elisa. Universidad Nacional de Mar del Plata. Facultad de Humanidades; Argentina.Fil: Pilcic, T. Universidad Nacional de Mar del Plata. Facultad de Humanidades; Argentina.Fil: Espinosa, A. Universidad Nacional de Mar del Plata. Facultad de Humanidades; Argentina.Fil: Lanari, María Estela. Universidad Nacional de Mar del Plata. Facultad de Ciencias Económicas y Sociales; Argentina.Fil: López, María Teresa. Universidad Nacional de Mar del Plata. Facultad de Ciencias Económicas y Sociales; Argentina.Fil: López, J. Universidad Nacional de Mar del Plata. Departamento de Televisión; Argentina.Fil: Salgado, P. Universidad Nacional de Mar del Plata. Departamento de Televisión; Argentina
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