466 research outputs found

    Biochemical and aggregation analysis of Bence Jones proteins from different light chain diseases

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    Deposition of immunoglobulin light chains is a result of clonal proliferation of monoclonal plasma cells that secrete free immunoglobulin light chains, also called Bence Jones proteins (Bence Jones proteins). These Bence Jones proteins are present in circulation in large amounts and excreted in urine in various light chain diseases such as light chain amyloidosis (AL), light chain deposition disease (LCDD) and multiple myeloma (MM). BJP from patients with AL, LCDD and MM were purified from their urine and studies were performed to determine their secondary structure, thermodynamic stability and aggregate formation kinetics. Our results show that LCDD and MM proteins have the lowest free energy of folding while all proteins show similar melting temperatures. Incubation of the BJP at their melting temperature produced morphologically different aggregates: amyloid fibrils from the AL proteins, amorphous aggregates from the LCDD proteins and large spherical species from the MM proteins. The aggregates formed under in vitro conditions suggested that the various proteins derived from patients with different light chain diseases might follow different aggregation pathways

    Crustal structure across the Costa Rican Volcanic Arc

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    Author Posting. © American Geophysical Union, 2013. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry, Geophysics, Geosystems 14 (2013): 1087–1103, doi:10.1002/ggge.20079.Island arcs are proposed to be essential building blocks for the crustal growth of continents; however, island arcs and continents are fundamentally different in bulk composition: mafic and felsic, respectively. The substrate upon which arcs are built (oceanic crust versus large igneous province) may have a strong influence on crustal genesis. We present results from an across-arc wide-angle seismic survey of the Costa Rican volcanic front which test the hypothesis that juvenile continental crust is actively forming at this location. Travel-time tomography constrains velocities in the upper arc to a depth of ~15 km where average velocities are <6.5 km/s. The upper 5 km of crust is constrained by velocities between 4.0 and 5.5 km/s, which likely represent sediments, volcaniclastics, flows, and small intrusions. Between 5 and 15 km depth, velocities increase slowly from 5.5 to 6.5 km/s. Crustal thickness and lower crustal velocities are roughly constrained by reflections from an inferred crust-mantle transition zone. Crustal thickness beneath the volcanic front in Costa Rica is ~40 km with best-fit average lower-crustal velocities between 6.8 and 7.1 km/s. Overall, velocities across the arc in central Costa Rica are at the high-velocity extreme of bulk continental crust velocities and are lower than modern island arc velocities, suggesting that continental compositions are created at this location. These data suggest that preexisting thick crust of the Caribbean Large Igneous Province has a measurable effect on bulk composition. This thickened arc crust may be a density filter for mafic material and thereby support differentiation toward continental compositions.Funding was provided by the NSF-MARGINS and ODP programs, under NSF grant OCE-0405654 and project Nº 113- A4-408 from the University of Costa Rica.2013-10-2

    TOXOPLASMOSIS IN MEXICO: EPIDEMIOLOGICAL SITUATION IN HUMANS AND ANIMALS

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    Seroepidemiology of Toxoplasma gondii infection in pregnant women in a public hospital in northern Mexico

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    BACKGROUND: Toxoplasma gondii (T. gondii) infection in pregnant women represents a risk for congenital disease. There is scarce information about the epidemiology of T. gondii infection in pregnant women in Mexico. Therefore, we sought to determine the prevalence of T. gondii infection and associated socio-demographic, clinical and behavioural characteristics in a population of pregnant women of Durango City, Mexico. METHODS: Three hundred and forty three women seeking prenatal care in a public hospital of Durango City in Mexico were examined for T. gondii infection. All women were tested for anti-T. gondii IgM and IgG antibodies by using IMx Toxo IgM and IMx Toxo IgG 2.0 kits (Abbott Laboratories, Abbott Park, IL, USA), respectively. Socio-demographic, clinical and behavioural characteristics from each participant were also obtained. RESULTS: Twenty one out of the 343 (6.1%) women had IgG anti-T. gondii antibodies. None of the 343 women had IgM anti-T. gondii antibodies. Multivariate analysis using logic regression showed that T. gondii infection was associated with living in a house with soil floor (adjusted OR = 7.16; 95% CI: 1.39–36.84), residing outside of Durango State (adjusted OR = 4.25; 95% CI: 1.72–10.49), and turkey meat consumption (adjusted OR = 3.85; 95% CI: 1.30–11.44). Other characteristics as cat contact, gardening, and food preferences did not show any association with T. gondii infection. CONCLUSION: The prevalence of T. gondii infection in pregnant women of Durango City is low as compared with those reported in other regions of Mexico and the majority of other countries. Poor housing conditions as soil floors, residing in other Mexican States, and turkey meat consumption might contribute to acquire T. gondii infection

    The Effect of Nanoparticles on Amyloid Aggregation Depends on the Protein Stability and Intrinsic Aggregation Rate

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    Nanoparticles interfere with protein amyloid formation. Catalysis of the process may occur due to increased local protein concentration and nucleation on the nanoparticle surface, whereas tight binding or a large particle/protein surface area may lead to inhibition of protein aggregation. Here we show a clear correlation between the intrinsic protein stability and the nanoparticle effect on the aggregation rate. The results were reached for a series of five mutants of single-chain monellin differing in intrinsic stability toward denaturation, for which a correlation between protein stability and aggregation propensity has been previously documented by Szczepankiewicz et al. [Mol. Biosyst 2010 7 (2), 521-532]. The aggregation process was monitored by thioflavin T fluorescence in the absence and presence of copolyrneric nanoparticles with different hydrophobic characters. For mutants with a high intrinsic stability and low intrinsic aggregation rate, we find that amyloid fibril formation is accelerated by nanoparticles. For find the opposite-a retardation of amyloid fibril formation by nanoparticles. Moreover, both catalytic and inhibitory effects are most pronounced with the least hydrophobic nanoparticles, which have a larger surface accessibility of hydrogen-bonding groups in the polymer backbone

    Differences in Immunoglobulin Light Chain Species Found in Urinary Exosomes in Light Chain Amyloidosis (AL)

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    Renal involvement is a frequent consequence of plasma cell dyscrasias. The most common entities are light chain amyloidosis, monoclonal immunoglobulin deposition disease and myeloma cast nephropathy. Despite a common origin, each condition has its own unique histologic and pathophysiologic characteristic which requires a renal biopsy to distinguish. Recent studies have shown urinary exosomes containing kidney-derived membrane and cytosolic proteins that can be used to probe the proteomics of the entire urinary system from the glomerulus to the bladder. In this study, we analyzed urine exosomes to determine the differences between exosomes from patients with light chain amyloidosis, multiple myeloma, monoclonal gammopathy of undetermined significance, and non-paraproteinemia related kidney disease controls. In patients with light chain amyloidosis, multiple myeloma and monoclonal gammopathy of undetermined significance, immunoreactive proteins corresponding to monomeric light chains were found in exosomes by western blot. In all of the amyloidosis samples with active disease, high molecular weight immunoreactive species corresponding to a decamer were found which were not found in exosomes from the other diseases or in amyloidosis exosomes from patients in remission. Few or no light chains monomeric bands were found in non-paraproteinemia related kidney disease controls. Our results showed that urinary exosomes may have tremendous potential in furthering our understanding of the pathophysiology and diagnosis of plasma cell dyscrasia related kidney diseases

    ABORDAJE FISIOTERAPEUTICO DE UN PACIENTE CON NEUMONIA ADQUIRIDA EN LA COMUNIDAD: ESTUDIO DE CASO

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    La neumonía es un proceso inflamatorio del parénquima pulmonar con una prevalencia importante en la primera infancia que depende de la edad, la constitución del paciente y de la etiología que la origina (1). Junto con la malnutrición y las enfermedades diarreicas  agudas se constituyen una de las principales causas de morbilidad y mortalidad de origen infeccioso en la población infantil menor de 5 años, convirtiéndose en un importante problema de salud pública

    PLAN DE ACCIÓN PARA LA CONSERVACIÓN DEL AGUARÁ GUAZÚ EN SANTA FE VERSIÓN 01 PERÍODO 2009 – 2014

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    El presente plan fue realizado usando de base los capítulos 1, 2, 3 y 4 del trabajo: Estado  de  conocimiento  y  conservación  del  aguará  guazú  (Chrysocyon  brachyurus)  en  la  provincia  de Santa Fe, Argentina. . Se tomó como base orientaciones generales de Margoluis y Salafsky (1998) y en la estructura general se siguió de modelo práctico a Jiménez Pérez (2006). Para asignar la prioridad se utilizaron las categorías desarrolladas por el Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renováveis (Baz Hughes, et al. 2006), estas son: Esencial: una actividad específica cuyo cumplimiento es necesario para evitar una declinación de las poblaciones que pueda llevar a la extinción de la especie en la naturaleza y/o en cautiverio. Alta: una actividad específica cuyo cumplimiento es necesario para evitar una declinación poblacional de más del 20% de una población en 20 años o menos. Media: una actividad específica cuyo cumplimiento es necesario para evitar una declinación poblacional de hasta el 20% de una población en 20 años o menos. Baja: una actividad específica cuyo cumplimiento es necesario para prevenir declinaciones poblacionales  locales o que se estima que dicha acción apenas tiene un pequeño impacto sobre las poblaciones en un área grande. Se trata de una planificación para cinco años pues la experiencia indica que a Santa Fe le falta mucho  trabajo  y experiencia para  fortalecer  su  forma de  ver  y de actuar en  la  recuperación de  las especies amenazadas.  Por ejemplo muchas de  las amenazas  indirectas (generadoras de amenazas directas) que afectan a esta especie son producto de  la  falta de coordinación, compromiso, metas y objetivos comunes entre  los profesionales de  la conservación, sea sociedad civil u organismos estatales. Es así como se pretende en un corto plazo y monitoreando constantemente, las acciones y sus resultados, lograr un plan a futuro de mediano y largo plazo.Fil: Biassati, R. Secreataría de Medio Ambiente de Santa Fe; ArgentinaFil: Larriera, Alejandro. Secretaría de Medio Ambiente de Santa Fe; ArgentinaFil: Mosso, E.. Secretaría de Medio Ambiente de Santa Fe; ArgentinaFil: Rozztti, J.C.. Secretaría de Medio Ambiente de Santa Fe; ArgentinaFil: Moggia, L.. Secretaría de Medio Ambiente, Santa Fe; ArgentinaFil: Pautasso, A.. Museo de Cs Naturales Florentino Ameghino; ArgentinaFil: Nebozuk, M. A.. Museo Provincial de Ciencias Naturales Ángel Gallardo; ArgentinaFil: Walker, C.. Universidad Nacional del Litoral; ArgentinaFil: Ramirez, C.. Universidad Nacional del Litoral; ArgentinaFil: Mirol, P.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Raimondi, Vanina Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Beldomenico, Pablo Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Santa Fe. Instituto de Ciencias Veterinarias del Litoral; Argentina. Laboratorio de Ecología de Enfermedades; ArgentinaFil: Eberhardt, María Ayelen Teresita. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Santa Fe. Instituto de Ciencias Veterinarias del Litoral; Argentina. Laboratorio de Ecología de Enfermedades; ArgentinaFil: Manzzoli, D.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Santa Fe. Instituto de Ciencias Veterinarias del Litoral; Argentina. Laboratorio de Ecología de Enfermedades; ArgentinaFil: Correa, A.. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias; ArgentinaFil: Terragona, E.. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias; ArgentinaFil: Magni, C.. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias; ArgentinaFil: Alvarado, S.. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias; ArgentinaFil: Barengo, E.. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias; Argentin

    The impact of the COVID-19 pandemic on the mental health of healthcare workers:study protocol for the COVID-19 HEalth caRe wOrkErS (HEROES) study

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    BACKGROUND: Preliminary country-specific reports suggest that the COVID-19 pandemic has a negative impact on the mental health of the healthcare workforce. In this paper, we summarize the protocol of the COVID-19 HEalth caRe wOrkErS (HEROES) study, an ongoing, global initiative, aimed to describe and track longitudinal trajectories of mental health symptoms and disorders among health care workers at different phases of the pandemic across a wide range of countries in Latin America, Europe, Africa, Middle-East, and Asia. METHODS: Participants from various settings, including primary care clinics, hospitals, nursing homes, and mental health facilities, are being enrolled. In 26 countries, we are using a similar study design with harmonized measures to capture data on COVID-19 related exposures and variables of interest during two years of follow-up. Exposures include potential stressors related to working in healthcare during the COVID-19 pandemic, as well as sociodemographic and clinical factors. Primary outcomes of interest include mental health variables such as psychological distress, depressive symptoms, and posttraumatic stress disorders. Other domains of interest include potentially mediating or moderating influences such as workplace conditions, trust in the government, and the country’s income level. RESULTS: As of August 2021, ~ 34,000 health workers have been recruited. A general characterization of the recruited samples by sociodemographic and workplace variables is presented. Most participating countries have identified several health facilities where they can identify denominators and attain acceptable response rates. Of the 26 countries, 22 are collecting data and 2 plan to start shortly. CONCLUSIONS: This is one of the most extensive global studies on the mental health of healthcare workers during the COVID-19 pandemic, including a variety of countries with diverse economic realities and different levels of severity of pandemic and management. Moreover, unlike most previous studies, we included workers (clinical and non-clinical staff) in a wide range of settings. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00127-021-02211-9
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