397 research outputs found

    Prescripción off-label de medicamentos: Definición y consideraciones ético-regulatorias en Argentina

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    Physicians are empowered to prescribe medications in a different manner than that it was approved by the regulatory agency, this means, outside of what is indicated in their package insert, for a specific patient. This may lead to the use of the drug in an indication other than that approved; or, in the same approved indication, but in a different subgroup of patients; or under different conditions. Off-label indications are the sole responsibility of the treating physician. So we wonder what precautions the professional should take in the prescriptive act, what rights the patient has in this regard, if said treatment should also be covered by medical insurance and what actions should the State take, if applicable, as the ultimate guarantor of the health of people residing in Argentina. The need and the special circumstances surrounding health issues determine that the prescription of off-label drugs is ethically and regulatory permissible. This must occur under certain conditions, arranged by the physician himself, but also from the authorities, in order to coordinate the participation of various actors in the system and the application of monitoring tools and favor adequate scientific information, all of which will support the off-label use of drugs to provide rational access in a specific case and accepted by the patient.Los médicos están facultados para prescribir medicamentos en una manera diferente a la aprobada por la agencia reguladora, es decir, por fuera de lo indicado en su prospecto, para un paciente determinado. Ello puede derivar en el uso del medicamento en una indicación distinta a la aprobada; o, en la misma indicación aprobada, pero en un distinto subgrupo de pacientes; o bien, bajo condiciones diferentes. Las prescripción fuera de prospecto o indicaciones “off-label” son de exclusiva responsabilidad del médico tratante. Entonces nos preguntamos qué precauciones debe adoptar el profesional en el acto prescriptivo, qué derechos tiene el paciente al respecto, si dicho tratamiento debe ser igualmente cubierto por el seguro médico y qué acciones debe tomar el Estado, en caso de corresponder, como garante último de la salud de las personas residentes en Argentina. La necesidad y las especiales circunstancias que rodean los temas de salud determinan que es ética y regulatoriamente permisible la prescripción de medicamentos fuera de prospecto u off label. Ello debe darse bajo condiciones determinadas, dispuestas por el mismo médico tratante, pero también desde las autoridades, a fin de coordinar la participación de diversos actores del sistema y la aplicación de herramientas de monitoreo y de favorecer la información científica adecuada, todo lo cual respaldará el uso fuera de prospecto u off label de medicamentos para brindar acceso racional en un caso en concreto y aceptado por el paciente

    XIX Asamblea general de la SAPSE

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    Ningun

    El sistema internacional de unidades y las mediciones eléctricas

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    We constantly use the results of measurements to trade, to take decisions, to reach compatibility between elements or to evaluate risks. The International System of Units (SI) is essential to express these results in a clear and comparable way. The SI is part of a diplomatic convention whose objective is to achieve international compatibility for trade, science, and sustainable development. Recently, a new definition of the SI has been approved, in which the system is defined in terms of seven reference constants whose numerical values are established by convention. In this way, the kilogram is disconnected from an artifact, the ampere from a theoretical experiment, and the kelvin and mole leave the definitions based on the property of a substance. Now, all the units of the system can be derived from the reference constants. The aim of this redefinition is to reach long-term stability, consistency, and coherence of the system, and to create a formal framework that fosters the growth of science and technology. This article focuses on the effects of redefinition in electrical units.Constantemente utilizamos los resultados de medidas para comercializar, tomar decisiones, compatibilizar elementos o valorar riesgos. El Sistema Internacional de Unidades (SI) es imprescindible para expresar los resultados de manera clara y comparable. El SI es el resultado de una convención diplomática cuyo objetivo es lograr la compatibilidad internacional de las mediciones para el comercio, la ciencia y el desarrollo sustentable. Recientemente, se aprobó una nueva definición del SI, en la cual el sistema es definido en términos de siete constantes de referencia cuyo valor numérico es establecido por convención. De esta manera, se dejó de lado la definición del kilogramo basada en un artefacto, la definición del ampere basada en un experimento teórico, y la definición del kelvin y del mol basadas en propiedades de sustancias. Ahora, cualquier unidad del sistema puede ser derivada a partir de las constantes de referencia. Esta redefinición tiene como objetivo la estabilidad a largo plazo, la consistencia y la coherencia del sistema, adecuándose a las necesidades de los usuarios y brindado un marco formal para potenciar el crecimiento de la ciencia y la tecnologı́a. En este artículo, se dará especial atención a los efectos de la redefinición en las unidades eléctricas

    Population Structure and Spatial Pattern in the Dioecious Shrub Ceratiola ericoides

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    The dioecious shrub Ceratiola ericoides (Florida rosemary) dominates xeric, infrequently burned Florida scrub vegetation, often to the near-exclusion of other woody species. We studied the spatial pattern, age, sex and size structure of four populations in Florida, USA: two coastal scrub populations subject to recurrent local disturbances due to sand movement, and two inland scrub populations in sites periodically burned by stand-replacing fires. The age structure of individual genets was estimated from node counts and used to describe the age structure of the populations. The sex ratio of males to females was not significantly different from 1:1, except within a female- biased coastal population subject to frequent sand movement. Node counts indicated that the mean age for reproductive individuals was 15 - 16 yr for the inland populations and 13 - 16 yr for the coastal populations. In all sites, there was no difference in mean age between males and females. Vegetative reproduction was uncommon except for the least-disturbed coastal population where 72 % of the reproductive individuals originated through layering. Individuals were generally randomly dispersed at the coastal sites, whereas significant aggregation of males and females occurred in the inland sites where the populations were initiated following fire. Seedling recruitment was continuous in the disturbed coastal scrub site, where 35 % of the individuals were juveniles. Most juveniles were dispersed from 0.5 to 0.75 m around females. At one of the inland sites, where juveniles comprised 11 % of the population, juveniles were clustered at 0.25 to 5.75 m around females. Coastal populations were all-aged, while inland populations were uneven-aged. Recruitment appears to follow periods of disturbance; infrequent fire in the inland populations and continuous sand movement on the coast are factors initiating recruitment

    Introgression of apomixis into sexual species is inhibited by mentor effects and ploidy barriers in the Ranunculus auricomus complex

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    Background and Aims Apomictic plants maintain functional pollen, and via pollination the genetic factors controlling apomixis can be potentially transferred to congeneric sexual populations. In contrast, the sexual individuals do not fertilize apomictic plants which produce seeds without fertilization of the egg cells. This unidirectional introgressive hybridization is expected finally to replace sexuality by apomixis and is thought to be a causal factor for the wide geographical distribution of apomictic complexes. Nevertheless, this process may be inhibited by induced selfing (mentor effects) of otherwise self-incompatible sexual individuals. Here whether mentor effects or actual cross-fertilization takes place between diploid sexual and polyploid apomictic cytotypes in the Ranunculus auricomus complex was tested via experimental crosses. ¿ Methods Diploid sexual mother plants were pollinated with tetra- and hexaploid apomictic pollen donators by hand, and the amount of well-developed seed compared with aborted seed was evaluated. The reproductive pathways were assessed in the well-developed seed via flow cytometric seed screen (FCSS). ¿ Key Results The majority of seed was aborted; the well-developed seeds have resulted from both mentor effects and cross-fertilization at very low frequencies (1.3 and 1.6% of achenes, respectively). Pollination by 4x apomictic pollen plants results more frequently in cross-fertilization, whereas pollen from 6x plants more frequently induced mentor effects. ¿Conclusions It is concluded that introgression of apomixis into sexual populations is limited by ploidy barriers in the R. auricomus complex, and to a minor extent by mentor effects. In mixed populations, sexuality cannot be replaced by apomixis because the higher fertility of sexual populations still compensates the low frequencies of potential introgression of apomixi

    Effects of Plant Sex on Range Distributions and Allocation to Reproduction

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    Despite an abundance of theory, few empirical studies have explored the ecological and evolutionary consequences of sex. We used a comparative phylogenetic approach to examine whether transitions between sexual and asexual reproduction are associated with changes in the size and distribution of species’ geographical ranges, and their investment in reproduction. Here, we reconstructed the phylogeny of the genus Oenothera sections Oenothera and Calylophus (Onagraceae), which contain 35 sexual and 30 functionally asexual species. From each species, we collected data on the geographical distribution and variation in plant traits related to reproduction. Functionally asexual species occurred at higher latitudes, but did not differ in range size, compared with sexual species. Transitions to asexuality were associated with decreased investment in floral structures, including the length of petals, floral tubes and styles. Decreased anther size and increased seed size within asexual species also suggest altered allocation to male and female fitness. The observed range shifts are consistent with superior colonization of environments by asexual species following glaciation, and the observed changes in reproductive allocation support predictions made by models relating to the evolution of selfing. Our results suggest that the evolutionary consequences of asexual reproduction might be less restrictive than previously thought

    Can plantations develop understory biological and physical attributes of naturally regenerated forests?

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    With an increasing proportion of natural forests being replaced by plantations, there is a need to determine their potential to fulfill ecological purposes other than wood production. This study evaluated the extent to which deciduous and coniferous plantations develop understory attributes comparable to those of naturally regenerated stands. A functional group approach was used to synthesise species responses in terms of their ecological traits. Multivariate analyses of ecological traits revealed 16 emergent groups that shared common traits associated with a similar life history strategy. Responses of these groups, understory structure, and understory environmental conditions to plantation types and stand stages were analyzed and compared to naturally regenerated stands. Clear associations of trait responses to stand developmental stages and plantation types emerged. Light-demanding and wind-dispersed species groups were associated with early-successional stages, while woody groups, ferns and ant-dispersed spring-flowering herbs were associated with late-successional stages. Analyses also revealed an indicator group associated with old naturally regenerated forest. The understory functional groups and environmental conditions of deciduous plantations converged toward those of old naturally regenerated forests. However, understory structure in deciduous plantations remained poorly developed and richness of the indicator group was low compared to unplanted stands. Conifer plantations, currently the most common plantation type in the northern hardwood biome, showed a completely different pathway of understory development. Modifications to current plantation management practices are proposed to help recreate or maintain natural understory biological and physical attributes

    Recovery of the herbaceous layer in the young silver birch and black alder stands that developed spontaneously after a forest fire

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    The studies, which were conducted in southern Poland, focused on the recovery of the herb layer in 17-year-old post-fire silver birch and black alder forests. Although both types of stands, which are of the same age, developed spontaneously, the alder stands occupied damper sites (with thicker A horizons that survived the fire) than those in the birch forests. We surveyed the migration rates of 44 woodland species, primarily ancient woodland indicators, into both forests and the potential differences in these rates depending on their moisture regime and the community type represented by unburned forests, which were treated as the source of the woodland species pool. Additionally, the role of local depressions with high humidity that were covered by post-fire alder woods in the colonization process, as well as species survivorship and recolonisation, were estimated. Woodland species showed diverse migration paces among the sites; most of them migrated faster on more fertile sites with a higher humidity. Small patches of post-fire alder woods contributed to the recolonisation process since many woodland species in the herb layer survived the fire due to its high humidity, which inhibited the intensity of the forest fire. The recovery of woodland species in post-fire woods is the combined effect of regeneration, which relies on autochthonic propagules, and secondary succession, which is based on allochthonic propagules. Local depressions, which provide refuges for fire-sensitive, dispersal-limited species, contribute to their survivorship and thus to the successive recovery of herbaceous layers after a fire
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