4,963 research outputs found

    Osmotic forces are not critical for Ca 2+ -induced secretion from permeabilized human neutrophils

    Full text link
    In order to examine the role of osmotic forces in degranulation, the effects of solutes and osmolality on granule secretion were explored using both FMLP-stimulated, intact neutrophils and Ca 2+ -stimulated, permeabilized cells. We employed a HEPES-based buffer system which was supplemented with: (a) permeant (KCl or NaCI) or impermeant (Na-isethionate or choline-CI) ions, or (b) permeant (urea) or impermeant (sucrose) uncharged solutes. Intact and permeabilized cells had significantly different solute requirements for degranulation. FMLP-stimulated release from intact cells was supported by NaCI or Na-isethionate > KCl > choline-Cl or sucrose > urea. In contrast, the rank order of Ca 2+ -stimulated release from permeabilized cells was choline-C > Na-isethionate, KCl, or NaCl > sucrose > urea. Hypo-osmotic conditions caused increased levels of background granule release from both intact and permeabilized neutrophils. However, hypo-osmolality inhibited both FMLP-stimulated degranulation from intact cells and Ca 2+ -induced release from permeabilized neutrophils. While hyperosmotic conditions inhibited stimulated release from intact cells, this inhibition was much less pronounced in permeabilized cells when the granules were directly exposed to these solutions. In fact, hyperosmotic sucrose greatly enhanced Ca 2+ -induced secretion. Although isolated specific and azurophil granules showed some lytic tendencies in hypo-osmotic buffers, the overall stability of the isolated granules did not indicate that swelling alone could effect degranulation. These results suggest that degranulation in permeabilized cells is neither due to nor driven by simple osmotic forces (under resting or stimulated conditions) and emphasize differences obtained by bathing both the granules and plasma membrane (as opposed to membranes alone) in various solutes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/49877/1/1041350204_ftp.pd

    Progression of a large syphilis outbreak in rural North Carolina through space and time: Application of a Bayesian Maximum Entropy graphical user interface

    Get PDF
    In 2001, the primary and secondary syphilis incidence rate in rural Columbus County, North Carolina was the highest in the nation. To understand the development of syphilis outbreaks in rural areas, we developed and used the Bayesian Maximum Entropy Graphical User Interface (BMEGUI) to map syphilis incidence rates from 1999–2004 in seven adjacent counties in North Carolina. Using BMEGUI, incidence rate maps were constructed for two aggregation scales (ZIP code and census tract) with two approaches (Poisson and simple kriging). The BME maps revealed the outbreak was initially localized in Robeson County and possibly connected to more urban endemic cases in adjacent Cumberland County. The outbreak spread to rural Columbus County in a leapfrog pattern with the subsequent development of a visible low incidence spatial corridor linking Roberson County with the rural areas of Columbus County. Though the data are from the early 2000s, they remain pertinent, as the combination of spatial data with the extensive sexual network analyses, particularly in rural areas gives thorough insights which have not been replicated in the past two decades. These observations support an important role for the connection of micropolitan areas with neighboring rural areas in the spread of syphilis. Public health interventions focusing on urban and micropolitan areas may effectively limit syphilis indirectly in nearby rural areas

    Bilingualism and language in children with autistic spectrum disorder: a systematic review

    Get PDF
    Introducción La comunicación y el lenguaje de las personas con trastorno del espectro autista (TEA) son algunos de los aspectos que más frecuentemente se ven alterados en este trastorno del neurodesarrollo. Cuando un niño que recibe el diagnóstico de TEA vive en un entorno bilingüe, los padres con frecuencia manifiestan su preocupación sobre si sus hijos deberían aprender dos idiomas simultáneamente y acuden a especialistas para ser aconsejados al respecto. A pesar de que no exista evidencia de sus efectos negativos, algunos profesionales se han mostrado en desacuerdo. Este trabajo pretende conocer si el bilingüismo afecta al lenguaje de niños con TEA. Desarrollo Se ha realizado una revisión de la literatura científica publicada en cuatro bases de datos y siguiendo una serie de criterios se han seleccionado 12 artículos publicados en revistas científicas. Participaron 328 niños diagnosticados con TEA (169 bilingües y 159 monolingües) con edades entre los 3 y 12 años, evaluados con diferentes pruebas de lenguaje receptivo y expresivo que abarcan áreas diversas. La evaluación se realizó de modo directo a los niños, aunque también se evaluaron indirectamente a los padres en algunos trabajos. Conclusiones Se ha comprobado en esta revisión que existe acuerdo sobre que el bilingüismo no supone ninguna dificultad adicional para el desarrollo del lenguaje de niños con TEA a partir de los 3 años

    On benevolence and love of others

    Get PDF
    Hobbes is famous for his insights into the impact of man’s fear, glory and greed on war and peace, not for his views on the bearing of men’s benevolence on the commonwealth. Are Hobbesian people even capable of love of others? In the literature, we find two main answers: one view is that Hobbes ruled out the possibility of disinterested benevolence among men; the other is that Hobbes considered actions driven by genuine benevolence possible but uncommon. After reviewing in broad outlines the two above positions, this chapter seeks to demonstrate the claim that Hobbes did not consider relevant to establish if men are capable of genuine benevolence or not, because he maintained that benevolent men can be as inept as egoists in differentiating apparent and real good for themselves and their loved ones and the effect of misguided altruism on the commonwealth is as damaging as the effect of ill-advised egoism.Postprin

    American Gut: an Open Platform for Citizen Science Microbiome Research

    Get PDF
    McDonald D, Hyde E, Debelius JW, et al. American Gut: an Open Platform for Citizen Science Microbiome Research. mSystems. 2018;3(3):e00031-18

    A communal catalogue reveals Earth's multiscale microbial diversity

    Get PDF
    Our growing awareness of the microbial world's importance and diversity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about microbial life on Earth. Here we present a meta-analysis of microbial community samples collected by hundreds of researchers for the Earth Microbiome Project. Coordinated protocols and new analytical methods, particularly the use of exact sequences instead of clustered operational taxonomic units, enable bacterial and archaeal ribosomal RNA gene sequences to be followed across multiple studies and allow us to explore patterns of diversity at an unprecedented scale. The result is both a reference database giving global context to DNA sequence data and a framework for incorporating data from future studies, fostering increasingly complete characterization of Earth's microbial diversity.Peer reviewe
    corecore