Interdisciplinarity and nursing research: opportunities and challenges / Interdisciplinaridade e pesquisa em enfermagem: oportunidades e desafios / La interdisciplinariedad y la investigación en enfermería: oportunidades y desafíos

Interdisciplinary collaboration is widely recognized and considered essential for optimizing the development of knowledge and practice. However, interdisciplinarity is commonly accepted as an unquestioned good; rarely examined as both a source of benefit as well as difficulty for nursing and other disciplines. The aim of this article is to critically examine the opportunities and challenges that interdisciplinarity can provide for research in nursing and other disciplines. Based on a North American perspective, I describe the emergence of uni-disciplinary nursing research and the knowledge exchanges that occurred between nursing and other disciplines. I discuss the rise of interdisciplinary research, outline several examples of nursing participation in interdisciplinarity, and highlight the prominent benefits and difficulties associated with interdisciplinary research. I argue that authentic collaboration is required to conduct meaningful interdisciplinary research and describe how this can be promoted.

Colaboração interdisciplinar é amplamente reconhecida e considerada essencial para a otimização do desenvolvimento do conhecimento e prática. No entanto, a interdisciplinaridade é comumente aceita como um bem inquestionável, raramente examinado tanto como uma fonte de benefícios, bem como dificuldade para a enfermagem e outras disciplinas. O objetivo deste artigo é analisar criticamente as oportunidades e desafios que a interdisciplinaridade pode oferecer para a pesquisa em enfermagem e outras disciplinas. Com base em uma perspectiva norte-americana, descreve-se o surgimento de pesquisas em enfermagem unidisciplinar e as trocas de conhecimento que ocorreram entre a enfermagem e outras disciplinas. Discute-se a ascensão da pesquisa interdisciplinar, delineiam-se vários exemplos de participação da enfermagem na interdisciplinaridade, e destacam-se os benefícios proeminentes e dificuldades associadas com a pesquisa interdisciplinar. Defende-se que a colaboração autêntica é necessária para conduzir a pesquisa interdisciplinar significativa e descreve-se como isso pode ser promovido.

La colaboración interdisciplinaria es ampliamente reconocida y considerada esencial para optimizar el desarrollo del conocimiento y la práctica. Sin embargo, la interdisciplinariedad es comúnmente aceptada como un bien incuestionable; rara vez examinada tanto como una fuente de beneficio, así como de dificultad para la enfermería y otras disciplinas. El objetivo de este artículo es examinar críticamente las oportunidades y desafíos que la interdisciplinariedad puede proporcionar para la investigación en enfermería y otras disciplinas. Sobre la base de una perspectiva norteamericana, describe-se el surgimiento de la investigación en enfermería unidisciplinaria y los intercambios de conocimientos que se produjeron entre la enfermería y otras disciplinas. Se discute el aumento de la investigación interdisciplinaria, esbozan-se varios ejemplos de la participación de enfermería en la interdisciplinariedad, y destacan-se los beneficios y las dificultades asociadas con la investigación interdisciplinaria. Argumenta-sé que se requiere auténtica colaboración para llevar a cabo la investigación interdisciplinaria significativa y describe-se la forma en que esto puede ser promovido. .

El sistema citocromo P450 y el metabolismo de xenobióticos / Cytochrome P450 system and xenobiotic metabolism

Los organismos están constantemente expuestos a una gran variedad de xenobióticos. Las enzimas citocromo P450 participan en la fase I del metabolismo de xenobióticos, incluyendo los fármacos, y en funciones biosintéticas endógenas por reacciones de oxidación, reducción e hidrólisis. En el hombre se estima que pueden metabolizar hasta dos tercios de las drogas y la mayor parte de estas reacciones ocurre en el hígado. Estas enzimas se encuentran en todos los reinos biológicos. Actualmente se conocen más de 18 000 genes citocromo P450 organizados en familias y subfamilias según el porcentaje de identidad de secuencia de sus aminoácidos, y este número aumenta cada año con el hallazgo de nuevas secuencias del genoma. Ellas son una superfamilia de hemoproteínas monooxidasas del sistema oxidasa de función mixta localizadas en las membranas del retículo endoplasmático liso y mitocondrial interna. La diversidad de reacciones que cataliza y su amplia especificidad de sustrato lo destacan como uno de los catalizadores más diversos y versátiles conocidos y juega un papel crítico en la bioquímica, farmacología y toxicología. Se realizó una búsqueda por palabras clave en las bases de datos Pubmed y Medscape en los últimos diez años. También se consultaron sitios de Internet relacionados con investigaciones del citocromo P450 como bases de datos. Esta revisión es una actualización sobre aspectos generales del citocromo P450 y comprende una breve historia de la investigación del citocromo P450, su sistema de nomenclatura estándar; y describe su multiplicidad, la distribución a nivel de órgano y localización subcelular, estructura y función(AU)

The organisms are constantly exposed to a wide array of xenobiotics. Cytochrome P450 enzymes are involved in the phase I of xenobiotic metabolism, including pharmaceuticals, and in endogenous biosynthetic functions through oxidation, reduction reactions and hydrolysis. It is estimated that cytochrome P450 can metabolize up to two-thirds of drugs present in humans and that the bulk of these reactions occur in the liver. These enzymes are found in all biological domains. More than 18 000 cytochrome P450 genes are currently known and arranged into families and subfamilies on the basis of amino acid sequence identity percentage, and this number increases each year as new genome sequences are reported. They are a superfamily of monooxidase hemoproteins in the oxidase system with mixed functions and found on the membranes of the smooth endoplasmic reticulum and in the inner mitochondrial membrane. The diversity of reactions that catalyzes and its extensive substrate specificity turn it into one of the most diverse and versatile catalysts ever known and plays a critical role in biochemistry, pharmacology and toxicology. A keyword search was performed in Pubmed and Medscape databases in the last ten years. Websites related to cytochrome P450 research as databases were also consulted. This updated review covered general aspects of cytochrome P450, a brief history of the research on this enzyme and its standard nomenclature system, and also described its multiplicity, its distribution in body organs and its sub-cellular location, structure and function(AU)

Conceitos e derivação de valores de referência para biomonitorização humana de contaminantes ambientais / Concepts and determination of reference values for human biomonitoring of environmental contaminants

Human biomonitoring (HBM) of environmental contaminants plays an important role in estimating exposure and evaluating risk, and thus it has been increasingly applied in the environmental field. The results of HBM must be compared with reference values (RV). The term "reference values" has always been related to the interpretation of clinical laboratory tests. For physicians, RV indicate "normal values" or "limits of normal"; in turn, toxicologists prefer the terms "background values" or "baseline values" to refer to the presence of contaminants in biological fluids. This discrepancy leads to the discussion concerning which should be the population selected to determine RV. Whereas clinical chemistry employs an altered health state as the main exclusion criterion to select a reference population (that is, a "healthy" population would be selected), in environmental toxicology the exclusion criterion is the abnormal exposure to xenobiotics. Therefore, the choice of population to determine RV is based on the very purpose of the RV to be determined. The present paper discusses the concepts and methodology used to determine RV for biomarkers of chemical environmental contaminants.

Signal transduction by xenobiotics in fish.

Signal transduction by xenobiotics in fish has recently gained much attention. The better known transduction mechanisms are those elicited by organochlorines, organophosphates, carbamates and heavy metals. Organochlorines specifically bind to the membrane bound ouabain sensitive Na+-K+-ATPase affecting neural transmission while the organophosphates and carbamates bind specifically to the membrane bound enzyme acetylcholinesterase again affecting neural transmission. Since the nervous system is one of the important integrative and interactive physiological systems in animals, hypofunction of the nervous system leads to secondary effects in the endocrine system including thyroidal, gonadal, interrenal, pituitary and hypothalamic functions. Even low levels of xenobiotics are efficient enough to bring about remarkable changes in the functional physiology of the non target animals. Heavy metals such as cadmium or mercury belonging to the same group II B in the periodic table probably have a similar mechanism of action. Avidity of these metals to SH-radicals allow them to bind indiscriminately to SH groups in proteins. One pathway of interaction by inorganic mercury with the membrane bound ouabain sensitive Na+-K+-ATPase has been clearly established in fish liver and ovary. Binding of inorganic mercury to the membrane bound enzyme is through sulfhydryl group which inactivates the sodium pump leading to accumulation of the cation in the cytosol. The inorganic mercury is next conjugated by the cytosolar nucleophile, glutathione, and is transported to the nucleus where dissociation occurs and the free metal binds to the metal regulatory element to initiate gene expression. The inducible proteins are 3beta-hydroxysteroid dehydrogenase in the oocyte and metallothionein and C-reactive protein in the liver. The present review deals with the role of xenobiotic as a stress factor.

Biomarcadores de susceptibilidad a metales con énfasis en salud humana / Susceptibility biomarkers of metals: emphasis in human health

Los biomarcadores son variables cuantificables que permiten determinar la exposición, el efecto y/o la susceptibilidad a un tóxico. La mayoría de los biomarcadores estudiados son de exposición y efecto. Mediante los biomarcadores de susceptibilidad pueden evaluarse las interacciones entre ciertos factores genéticos (p. ej. polimorfismos enzimáticos) y externos (p. ej. exposición simultánea a otros agentes, estatus nutricional, etc.). Los metales han ido adquiriendo un creciente interés en relación con la salud ambiental y humana debido a su alta toxicidad y los biomarcadores pueden ser útiles en el desarrollo de estrategias de prevención y diagnóstico temprano de sus eventuales efectos adversos. En el presente trabajo se detallan los efectos de la interacción sinérgica y antagonista de metales, valencia del metal, metalotioneínas, glutation-S-transferasas, enfermedades crónicas, nicotina, edad, sexo, etc., en relación con la susceptibilidad a la toxicidad de metales. Por ej., una deficiencia en Ó1-antitripsina (AAT), un biomarcador de utilidad para detectar individuos hipersensibles a sustancias irritantes del sistema respiratorio (p. ej. Cr, Mn, Pb, Be, etc.) y con elevado riesgo de sufrir de enfisema pulmonar, permite anticipar los riesgos ocupacionales que podrían sufrir individuos con estas características. Los biomarcadores de sustancias potencilamente tóxicas podrían ser de gran utilidad para realizar las reglamentaciones sobre bases científicas, vinculadas con los niveles máximos admisibles de las sustancias en el ambiente