Recuento de neutrófilos asociado al fenotipo Duffy nulo / Neutrophil count associated with the Duffy phenotype null

Introducción. El fenotipo Duffy nulo es una variante de la normalidad de los antígenos de membrana de las células sanguíneas que ocasiona la forma más frecuente de neutropenia congénita a nivel mundial. Los individuos que la poseen, mayoritariamente provenientes de regiones de África subsahariana, presentan de forma persistente recuentos de neutrófilos por debajo del rango normal, sin que esto implique aumento en el riesgo de infecciones. Caso clínico. Presentamos un lactante, seguido en nuestro Servicio de Neonatología, por neutropenia persistente desde el nacimiento, hijo de una madre procedente de Guinea Ecuatorial. Tras varias analíticas se pudo comprobar el diagnóstico de neutropenia congénita asociada a Duffy nulo a través de inmunofenotipo de sangre periférica. La evolución del niño fue satisfactoria y no presentó ninguna complicación por su neutropenia. Conclusiones. Se debe clasificar la Neutropenia Congénita Asociada a Duffy Nulo (DANC, en sus siglas en inglés) como un polimorfismo genético que genera una variante de la normalidad, adecuando los rangos de los recuentos de neutrófilos a la misma. No se ha visto aumento en el riesgo de infecciones o enfermedades autoinmunes, ni alteraciones en la función de los neutrófilos. Considerar a estos pacientes con los rangos normales de la mayoría de la población tiene consecuencias como pruebas innecesarias, exclusión de ensayos clínicos o no administración de tratamientos oncológicos (AU)

Introduction. The Duffy-null phenotype is a variant of normal blood cell membrane antigens that causes the most frequent form of congenital neutropenia worldwide. Individuals who have it, mostly from sub-Saharan Africa, persistently have neutrophil counts below the normal range, without this implying an increased risk of infections. Case report. We present a child, followed in our Neonatology Service, due to persistent neutropenia from birth, son of a mother from Equatorial Guinea. After several tests, the diagnosis of congenital neutropenia associated with Duffy null could be verified through peripheral blood immunophenotyping. The evolution of the child was satisfactory and he did not present any complications due to his neutropenia Conclusions. Duffy-Null Associated Congenital Neutropenia (DANC) should be classified as a genetic polymorphism that generates a variant of normality, adapting the ranges of neutrophil counts to it. There has been no increase in the risk of infections or autoimmune diseases, nor alterations in the function of neutrophils. Considering these patients within the normal ranges of the majority of the population has consequences such as unnecessary tests, exclusion from clinical trials, or non-administration of oncological treatments (AU)

Effect of tri- and tetravalent metal doping on the electrochemical properties of lanthanum tungstate proton conductors.

Rare-earth tungstates (La(28-y)W(4+y)O(54+δ)□(2-δ)) have attracted attention recently because of their relatively high proton-electron conductivity and high stability in a CO2 environment. Since doping on the tungsten-site may increase the conductivity, a new series of compounds with composition La(5.5)W(1-x)M(x)O(11.25-δ) (M = Al, Ti and Zr; x = 0, 0.05 and 0.10) have been investigated. The crystal structure of these materials has been studied using X-ray and time-of-flight neutron powder diffraction by Rietveld analysis. The concentration of oxygen vacancies for hydration in the structure has been indirectly determined by thermogravimetric analysis, and the total conductivity in several pO2, pH2O and pD2O atmospheres has been studied by impedance spectroscopy. An increase in the conductivity is observed, ranging from 4.1 mS cm(-1) for the undoped sample to 9.2 mS cm(-1) for La(5.5)W(0.9)Ti(0.1)O(11.25-δ), in wet N2 at 800 °C.

Novel microstructural strategies to enhance the electrochemical performance of La0.8Sr0.2MnO3-δ cathodes.

Novel strategies based on spray-pyrolysis deposition are proposed to increase the triple-phase boundary (TPB) of La0.8Sr0.2MnO3-δ (LSM) cathodes in contact with yttria-stabilized zirconia (YSZ) electrolyte: (i) nanocrystalline LSM films deposited on as-prepared YSZ surface; (ii) the addition of poly(methyl methacrylate) microspheres as pore formers to further increase the porosity of the film cathodes; and (iii) the deposition of LSM by spray pyrolysis on backbones of Zr0.84Y0.16O1.92 (YSZ), Ce0.9Gd0.1O1.95 (CGO), and Bi1.5Y0.5O3-δ (BYO) previously fixed onto the YSZ. This last method is an alternative to the classical infiltration process with several advantages for large-scale manufacturing of planar solid oxide fuel cells (SOFCs), including easier industrial implementation, shorter preparation time, and low cost. The morphology and electrochemical performance of the electrodes are investigated by scanning electron microscopy and impedance spectroscopy. Very low values of area specific resistance are obtained, ranging from 1.4 Ω·cm(2) for LSM films deposited on as-prepared YSZ surface to 0.06 Ω-cm(2) for LSM deposited onto BYO backbone at a measured temperature of 650 °C. These electrodes exhibit high performance even after annealing at 950 °C, making them potentially suitable for applications in SOFCs at intermediate temperatures.

Proton conductors based on alkaline-earth substituted La(28-x)W(4+x)O(54+3x/2).

Lanthanum tungstates, "La6WO12", are mixed ion proton-electronic conductors with very interesting properties for technological applications and better phase stability compared to alkaline earth perovskites. A new series of compounds La(27.04-x)M(x)W(4.96)O(55.44-x/2□8.56+x/2) (M = Ca(2+), Sr(2+) and Ba(2+)) are investigated with the aim of increasing the concentration of oxygen vacancies and studying their effects on the structure and transport properties. The materials have been studied by high-resolution laboratory X-ray powder diffraction and scanning electron microscopy combined with energy dispersive spectroscopy (EDS). High temperature X-ray powder diffraction and thermal analysis in wet and dry N2 gas did not show any evidence of phase transition up to 800 °C. The total conductivity was studied by impedance spectroscopy under dry and wet atmospheres and as a function of the oxygen partial pressure. The electronic contribution to the conductivity was determined by the Hebb-Wagner polarization method. The generation of extrinsic vacancies in the lattice with alkaline earth doping leads to a decrease of the ionic conductivity for high doping level, suggesting a proton trapping mechanism.

Knowledge acquisition and information searching strategies in diagnostic decision making.

The effect of three learning procedures on diagnostic information searching strategies was investigated. Undergraduate students acquired an artificial knowledge domain through either a Taxonomic-, Inductive-, or Case-oriented knowledge acquisition procedure. The use of the competing-hypotheses heuristic as a practical strategy to guide decision making in the face of uncertainty, was compared among the three learning conditions and between each condition and a non-learning control group using the method developed by Kern and Doherty (1982) and Wolf et al. (1985). The small instruction intervention had an effect on the diagnostic nature of subjects' information-searching strategies. Subjects in the Inductive-learning condition exhibited a stronger tendency to seek diagnostically worthless information than the other learning conditions. The outcomes are considered relevant to the nature of expertise in decision making, and to the effect of instruction methodologies on the knowledge representations available to diagnostic classification and decision-making processes.

Residency performance of graduates from a problem-based and a conventional curriculum.

Performance of 130 graduates in residency from a community-oriented, problem-based medical curriculum, and from a parallel, conventional track, were compared on eight dimensions: knowledge, communication with patients, independent learning ability, teamwork, patient education, critical thinking ability, attention to health care costs, and self-assessment. Ratings were obtained from three evaluators: a doctor-supervisor, a nurse and the resident him/herself. The study was undertaken to identify differences between graduates from the two curricular tracks. Differences were observed in the areas of health care costs (supervisors) and communication with patients (residents), and a trend was observed in patient education (supervisors) and knowledge (nurses), The outcomes of the study are discussed in light of the literature on residency performance, and in terms of the educational experiences that characterize the two medical curricula.