233 research outputs found

    Heavy Metals in Liver of the Franciscana Dolphin, Pontoporia blainvillei, from the Southern Coast of Buenos Aires, Argentina

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    The present study shows the considerable concentrations of heavy metals found in the liver of franciscana dolphins (n=24) by-caught between 2001 and 2007 in four localities of Buenos Aires province. Concentration of heavy metals such as Zn, Cu, Pb, Cd and Ni were manifested in the four assessed localities, yet Cr was only detected in one of them, Necochea city. Differences according localities (Necochea and Claromecó) were found for Zn, Ni, Pb and Cu concentration. It was found that Cd concentrations were significantly different between maturity stages, yet positive correlated with age, total length and body weight. A positive correlation between Ni-Cd and a negative between Cu-Ni concentrations were registered. Based on these results, it is feasible to conclude that, not only the area of origin, but also total length, age and mainly the feeding habit, have taken part of this heavy metals accumulation in franciscana dolphins’ liver. Keywords: Argentina, Buenos Aires, franciscana, heavy metals, Pontoporia blainvillei.

    Dominance of the planktonic diatom Thalassiosira minima in recent summers in the Bahia Blanca Estuary, Argentina

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    The diatom Thalassiosira minima was first recorded in the Baha Blanca Estuary in 1992. In 19921993 it exhibited a broad seasonal occurrence. A recent survey (20062007) showed a seasonal appearance restricted mainly to summer together with a greater relative abundance within the phytoplankton. A close connection was found with warmer, more saline and highly turbid conditions experienced in recent summers in the estuary. Whether these changes will impact the estuary trophic dynamics remains an open question

    Structure of a clade C HIV-1 gp120 bound to CD4 and CD4-induced antibody reveals anti-CD4 polyreactivity

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    Strategies to combat HIV-1 require structural knowledge of envelope proteins from clade C viruses, the most common in the world. We present the first crystal structure containing a clade C gp120 envelope. The structure, a complex between gp120, the host receptor CD4, and the CD4-induced antibody 21c, reveals that the 21c epitope involves contacts with gp120, a non-self antigen, and with CD4, an auto-antigen. Binding studies using wild-type and mutant CD4 showed that 21c Fab binds CD4 in the absence of gp120, and that binding of 21c to clade C and HIV-2 gp120s requires the crystallographically-observed 21c-CD4 interaction. Additional binding data suggested a role for the gp120 V1V2 loop in creating a high-affinity, but slow-forming, epitope for 21c after CD4 binds. This study represents the first visualization of a potentially autoreactive antibody Fab complexed with both self and non-self antigens

    Estrategia de resolución del problema de ruteo de vehículos aplicado a la recolección y transporte de residuos patológicos generados en establecimientos de salud

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    Las principales actividades vinculadas a la logística de la gestión de residuos patológicos son las operaciones seguras de recolección, transporte y descarga en los sitios de tratamiento de estos materiales. La coordinación de los tiempos de estas operaciones es esencial para evitar la proliferación de enfermedades entre el personal de salud, los trabajadores encargados de la gestión y la comunidad en general. La coordinación de las diferentes actividades involucradas resulta en un problema complejo de toma de decisiones, más aún si se considera el comportamiento estocástico de la generación de residuos patológicos. En este contexto, el trabajo presenta un modelo matemático mixto entero lineal basado en el concepto de robustez ligera y una estrategia de resolución computacionalmente eficiente para el problema de operación regular de recolección y transporte hasta su lugar de tratamiento de residuos patológicos generados en establecimientos de salud, como hospitales y sanatorios. El problema consiste en un problema de ruteo de vehículos del tipo capacitado y con viajes múltiples. Los problemas de ruteo de vehículos son caracterizados como NP-hard de optimización combinatoria. Por lo tanto, los resolvedores comúnmente usados para resolver problemas de Programación Matemática Enteros, usualmente fallan en encontrar una solución óptima en un tiempo de ejecución razonable. De aquí la necesidad de implementar alguna técnica particular que permita resolver el problema en tiempo eficiente. En el trabajo se aborda un caso real tomado de la literatura y se detalla la metodología de resolución propuesta.The main activities related to pathological waste management logistics are the safe operations of collection, transport and unloading at treatment sites for these materials. The coordination of the times of these operations is essential to avoid the proliferation of diseases among health personnel, workers in charge of management and the community in general. The coordination of the different activities involved results in a complex decision-making problem, even more so if the stochastic behavior of pathological waste generation is considered. In this context, the work presents a linear integer mixed mathematical model based on the concept of light robustness and a computationally efficient solution strategy for the problem of regular operation of collection and transport, to its place of treatment, of pathological waste generated in health establishments, such as hospitals and sanatoriums. The problem consists of a vehicle routing problem of the type capacitated and with multiple trips. Vehicle routing problems are characterized as combinatorial optimization NP-hard. Therefore, the solvers commonly used to solve Integer Mathematical Programming problems usually fail to find an optimal solution in a reasonable execution time. Hence the need to implement some particular technique that allows solving the problem in an efficient time. The paper deals with a real case taken from the literature and details the proposed resolution methodology.Sociedad Argentina de Informática e Investigación Operativ

    Maternal but Not Paternal Association of Ambulatory Blood Pressure With Albumin Excretion in Young Offspring With Type 1 Diabetes

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    OBJECTIVE: Familial predisposition to hypertension has been associated with the development of diabetic nephropathy in adults, but there are limited data in adolescents. Our aim was to assess whether parental ambulatory blood pressure (ABP) was associated with ABP and albumin excretion in young offspring with type 1 diabetes. RESEARCH DESIGN AND METHODS: Twenty-four-hour ABP monitoring was performed in 509 young offspring (mean +/- SD age 15.8 +/- 2.3 years) with type 1 diabetes, 311 fathers, and 444 mothers. Systolic (SBP) and diastolic blood pressure (DBP) measurements during 24 h, daytime, and nighttime were calculated. Three early morning urinary albumin-to-creatinine ratios (ACRs), A1C, and anthropometric parameters were available for the offspring. RESULTS: All paternal ABP parameters, except for nighttime SBP, were independently related to the offspring's ABP (24-h SBP beta = 0.18, 24-h DBP beta = 0.22, daytime SBP beta = 0.25, daytime DBP beta = 0.23, and nighttime DBP beta = 0.18; all P < 0.01). Maternal 24-h DBP (beta = 0.19, P = 0.004), daytime DBP (beta = 0.09, P = 0.04), and nighttime SBP (beta = 0.24 P = 0.001) were related to the corresponding ABP parameter in the offspring. Significant associations were found between the offspring's logACR and maternal ABP. The association with 24-h DBP (beta = 0.16, P = 0.02), daytime DBP (beta = 0.16 P = 0.02), and nighttime DBP (beta = 0.15 P = 0.03) persisted even after adjustment for the offspring's ABP. Mothers of offspring with microalbuminuria had higher ABP than mothers of offspring without microalbuminuria (all P < 0.05). CONCLUSIONS: In this cohort, parental ABP significantly influenced offspring blood pressure, therefore confirming familial influences on this trait. In addition, maternal ABP, particularly DBP, was closely related to ACR in the offspring, suggesting a dominant effect of maternal genes or an effect of the intrauterine environment on microalbuminuria risk

    Medication adherence during adjunct therapy with statins and ACE inhibitors in adolescents with type 1 diabetes

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    OBJECTIVE: Suboptimal adherence to insulin treatment is a main issue in adolescents with type 1 diabetes. However, to date, there are no available data on adherence to adjunct noninsulin medications in this population. Our aim was to assess adherence to ACE inhibitors and statins and explore potential determinants in adolescents with type 1 diabetes. RESEARCH DESIGN AND METHODS:There were 443 adolescents with type 1 diabetes recruited into the Adolescent Type 1 Diabetes Cardio-Renal Intervention Trial (AdDIT) and exposed to treatment with two oral drugs—an ACE inhibitor and a statin—as well as combinations of both or placebo for 2–4 years. Adherence was assessed every 3 months with the Medication Event Monitoring System (MEMS) and pill count. RESULTS: Median adherence during the trial was 80.2% (interquartile range 63.6–91.8) based on MEMS and 85.7% (72.4–92.9) for pill count. Adherence based on MEMS and pill count dropped from 92.9% and 96.3%, respectively, at the first visit to 76.3% and 79.0% at the end of the trial. The percentage of study participants with adherence ≥75% declined from 84% to 53%. A good correlation was found between adherence based on MEMS and pill count (r = 0.82, P < 0.001). Factors associated with adherence were age, glycemic control, and country. CONCLUSIONS: We report an overall good adherence to ACE inhibitors and statins during a clinical trial, although there was a clear decline in adherence over time. Older age and suboptimal glycemic control at baseline predicted lower adherence during the trial, and, predictably, reduced adherence was more prevalent in subjects who subsequently dropped out

    Increasing the Potency and Breadth of an HIV Antibody by Using Structure-Based Rational Design

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    Antibodies against the CD4 binding site (CD4bs) on the HIV-1 spike protein gp120 can show exceptional potency and breadth. We determined structures of NIH45-46, a more potent clonal variant of VRC01, alone and bound to gp120. Comparisons with VRC01-gp120 revealed that a four-residue insertion in heavy chain complementarity–determining region 3 (CDRH3) contributed to increased interaction between NIH45-46 and the gp120 inner domain, which correlated with enhanced neutralization. We used structure-based design to create NIH45-46^(G54W), a single substitution in CDRH2 that increases contact with the gp120 bridging sheet and improves breadth and potency, critical properties for potential clinical use, by an order of magnitude. Together with the NIH45-46–gp120 structure, these results indicate that gp120 inner domain and bridging sheet residues should be included in immunogens to elicit CD4bs antibodies

    Iron and Calcium Biomineralizations in the Pampean Coastal Plains, Argentina: Their Role in the Environmental Reconstruction of the Holocene

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    Biomineralizations are biogenic composites, crystalline or amorphous,produced by the metabolic activity of organisms distributed all over the world. Theaim of this work was to evaluate the presence of iron and calcium biomineralizationsand their influence in the physicochemical and mineralochemical variations inpaleo and actual pedosedimentary sequences of the coastal plains in Mar Chiquita.The complex interaction of calcium with iron biomineralizations, as framboidal andpoliframboidal pyrites associated with gypsum, barite, calcite, halite, and iron oxyhydroxides,have demonstrated the active and complex biogeochemistry that occursin the temperate?wet paleoesturaries and estuaries of the coastal Pampean Plains.Particularly the consequences that different human activities could have.Fil: Osterrieth, Margarita Luisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Frayssinet, Celia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Geología de Costas y del Cuaternario. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto de Geología de Costas y del Cuaternario; ArgentinaFil: Frayssinet, Lucrecia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin

    Restricting HIV-1 pathways for escape using rationally designed anti–HIV-1 antibodies

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    Recently identified broadly neutralizing antibodies (bNAbs) that potently neutralize most HIV-1 strains are key to potential antibody-based therapeutic approaches to combat HIV/AIDS in the absence of an effective vaccine. Increasing bNAb potencies and resistance to common routes of HIV-1 escape through mutation would facilitate their use as therapeutics. We previously used structure-based design to create the bNAb NIH45-46G54W, which exhibits superior potency and/or breadth compared with other bNAbs. We report new, more effective NIH45-46^(G54W) variants designed using analyses of the NIH45-46–gp120 complex structure and sequences of NIH45-46^(G54W)–resistant HIV-1 strains. One variant, 45-46m2, neutralizes 96% of HIV-1 strains in a cross-clade panel and viruses isolated from an HIV-infected individual that are resistant to all other known bNAbs, making it the single most broad and potent anti–HIV-1 antibody to date. A description of its mechanism is presented based on a 45-46m2–gp120 crystal structure. A second variant, 45-46m7, designed to thwart HIV-1 resistance to NIH45-46G54W arising from mutations in a gp120 consensus sequence, targets a common route of HIV-1 escape. In combination, 45-46m2 and 45-46m7 reduce the possible routes for the evolution of fit viral escape mutants in HIV-1_(YU-2)–infected humanized mice, with viremic control exhibited when a third antibody, 10–1074, was added to the combination
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