Papers by uriel corona sanchez
Revista de Gastroenterología del Perú, Oct 1, 2012
El Síndrome de Intestino irritable (SII) es una entidad cuya prevalencia varía según el método ut... more El Síndrome de Intestino irritable (SII) es una entidad cuya prevalencia varía según el método utilizado para diagnosticarlo. Objetivo: determinar la prevalencia del SII en Chiclayo-Perú durante el año 2011. Materiales y métodos: población diana: personas entre 18 y 60 años; diseño de estudio: descriptivo transversal. Tamaño muestral: 195 personas, muestreo aleatorio, estratificado multietápico. Se entrevistó casa a casa usando una ficha de recolección de datos basada en los Criterios de Roma III. Se utilizó estadística descriptiva y análisis bivariado para medir asociación entre SII y variables epidemiológicas. Resultados: 200 personas fueron entrevistadas, 76 varones (38%) y 124 mujeres (62%). La media de edad fue 38,8 años ± 12,7. La prevalencia de SII fue de 15%; siendo la localización del dolor más frecuente el mesogastrio (26,7%); predominando las heces "pastosas" (30%) y la "diarrea" (36,7%). 20 personas con SII (66,7%) trabajaban y/o estudiaban. No hubo asociación entre SII y sexo femenino ni "ocupación" (Odds de prevalencia: 1,51; IC95%: 0,31-3,99 y 1,23; IC95%: 0,51-3,15 respectivamente). Conclusiones: la prevalencia de SII en Chiclayo es elevada, más frecuente en mujeres y quienes laboran o estudian; la diarrea, la consistencia pastosa de las heces y el dolor mesogástrico fueron las manifestaciones clínicas más frecuentes. PALABRAS CLAVE: Síndrome de Intestino Irritable, diarrea, prevalencia. Fuente: DECS BIREME
Geochemical indicators of petroleum composition provide especially useful and cost-effective tool... more Geochemical indicators of petroleum composition provide especially useful and cost-effective tools for evaluating reservoir continuity and allocating commingled production (Kaufman et al., 1990; Kaufman et al., 1997; McCaffrey et al., 2006; Hwang et al., 2000). These geochemical tools are highly complementary to engineering methods for deriving reservoir continuity information, and can effectively replace some engineering methods for allocating commingled production (Hwang et al., 1999). Using geochemistry to understand better the characteristics of reservoirs and reservoir fluids allows engineers to maximize the recovery of hydrocarbon fluids in a field and to determine how many wells should be drilled, where wells should be drilled, and how to maximize the production. Results of a case study of a well in the Llanos Basin in Colombia are presented to demonstrate how the gas-chromatographic (GC) fingerprints of oils from the well were evaluated using InfoLogic’s ReserViewTM and OilUnmixerTM software to successfully delineate the producing reservoir intervals, identify vertical reservoir fluid compartments, as well as estimate and monitor the production allocation of a two-zone completion over a seven-month period. The results from the unbiased comparison of the oils using the programs identified the reason for a reduction in production, why the American Petroleum Institute (API) gravity of the commingled oil decreased, and why the gasoil ratio (GOR) increased over the seven-month period. The geochemical approach cost approximately 95 percent less than if three production logging tool (PLT) events had been employed. In the initial discovery stage of the well, four drill stem test (DST) oils were produced in August 2007: DST-1 from the lower zone Upper Cretaceous (two sands), DST2 from the upper Eocene zone (one sand), DST-3 from the upper Eocene zone (three sands – including the one sand from DST-2), and DST-4 that was a combination of the upper zone three sands and the lower zone two sands. The operator initially wanted to determine if there was vertical continuity between the upper and lower zones. A comparison of the gas chromatograms of the oils using InfoLogic’s ReserViewTM software was performed using the DST-3 oil (the upper zone three sands) and the DST-1 oil (the lower zone two sands). Figure 1. For the analytical comparison of oil fingerprints it is critical to ensure that users are comparing the same peaks in each oil. This can be difficult due to the fact that retention times shift slightly from oil to oil. This figure shows how ReserViewTM uses Kovats indices to triangulate on each peak and align them for all oil samples. The software then color codes each peak to allow easy comparison for the user. As seen in Figure 1, ReserViewTM uses Kovats indices to align all the peaks in the oil fingerprints and then color-codes them for easy comparison and visualization. This step is critical in the evaluation process because it compensates for retention time shift and ensures that all calculations are correctly performed on the same peaks across multiple samples. Once the GC range is selected, the user can quickly scan through the carbon ranges to select the peaks to be used for the oil comparison. ReserViewTM then determines the peak height ratios of adjacent peak pairs (Fig. 2). The relative standard deviation (RSD) is calculated for each set of peaks and the RSDs are ranked from largest to smallest. The RSDs indicate the mathematical differences between the oils that cannot readily be observed by just a visual comparison. The peak height ratios from the GC range are then plotted using a star plot, as seen in Figure 3, and on a dendogram, as seen in Figure 4, to provide easy visualization of the similarities or differences between the oils. Both Figures 3 and 4 indicate that the oils are chemically distinct; when these data are considered in light of the field geology and field engineering data, the geochemist can draw the conclusion that there are two vertical reservoir compartments with no fluid communication between the upper and lower zones. It should be noted that in the past, calculations such as these took much more time to perform and were often fraught with errors due to the fact the user could not accurately identify the same peak in multiple chromatograms. With InfoLogic’s ReserViewTM software, a comparison such as this can be performed in a few minutes. Figure 2. ReserViewTM calculates the ratio of peaks within a carbon range (e.g. between nC8-nC-9) by calculating the ratio of the peak heights. ReserViewTM then calculates the Relative Standard Deviation (RSD) and ranks those. These mathematical comparisons allow users to detect differences between oils that cannot be detected visually. Once it was determined that the upper and lower zones were not in vertical communication, geologists could use those same single-zone oils and the commingled oil to allocate quantitatively the contribution…
... Juan Manuel Pérez Suárez Estudios del discurso en Colombia Compiladores Gladys Lucia Acosta .... more ... Juan Manuel Pérez Suárez Estudios del discurso en Colombia Compiladores Gladys Lucia Acosta ... Ricaurte Avendaño La fotografía como dispositivo mágico Gabriel Mario Vélez Salazar Lectura y ... o acerca de las múltiples lecturas de lo real EMa María González Agudelo ...
Números, 2004
Las imágenes hablan por sí solas y una imagen vale más que mil palabras son algunas de las id... more Las imágenes hablan por sí solas y una imagen vale más que mil palabras son algunas de las ideas más frecuentes cuando se trata de definir la relación que existe entre el espectador y la imagen que mira. Esta visión ha sido revisada e incluso refutada por autores como ...
Journal of Biological Chemistry, 2020
Solute carrier family 20 member 2 (SLC20A2) and xenotropic and polytropic retrovirus receptor 1 (... more Solute carrier family 20 member 2 (SLC20A2) and xenotropic and polytropic retrovirus receptor 1 (XPR1) are transporters with phosphate uptake and efflux functions, respectively. Both are associated with primary familial brain calcification (PFBC), a genetic disease characterized by cerebral calcium-phosphate deposition and associated with neuropsychiatric symptoms. The association of the two transporters in the same disease suggests that they jointly regulate phosphate fluxes and cellular homeostasis, but direct evidence is missing. Here, we found that cross-talk between SLC20A2 and XPR1 regulates phosphate homeostasis and identify XPR1 as a key inositol polyphosphate (IP)-dependent regulator of this process. We found that overexpression of wildtype SLC20A2 increases phosphate uptake as expected, but also unexpectedly increases phosphate efflux, whereas PFBC-associated SLC20A2 variants did not. Conversely, SLC20A2 depletion decreased phosphate uptake only slightly, most likely compe...
Scientific Reports, 2019
Primary familial brain calcification (PFBC) is a rare neurological disease characterized by depos... more Primary familial brain calcification (PFBC) is a rare neurological disease characterized by deposits of calcium phosphate in the basal ganglia and other regions of the brain. Pathogenic variants in the XPR1/SLC53A1 gene, which encodes the only known inorganic phosphate exporter, cause an autosomal dominant form of PFBC. These variants are typically located in the SPX N-terminal domain of the protein. Here, we characterize three XPR1 variants outside of SPX in three PFBC patients with an apparently sporadic presentation: c.1375C > T p.(R459C), c.1855A > G p.(N619D) and c.1886T > G p.(I629S), with the latter identified as the first XPR1/SLC53A1 de novo mutation to occur in a PFBC proband. When tested in an in vitro physiological complementation assay, the three XPR1 variants were impaired in phosphate export function, although they were normally expressed at the cell surface and could serve as functional receptors for retrovirus entry. Moreover, peripheral blood cells from th...
Journal of neurology, Jan 26, 2016
Mutations in XPR1, a gene encoding an inorganic phosphate exporter, have recently been identified... more Mutations in XPR1, a gene encoding an inorganic phosphate exporter, have recently been identified in patients with primary familial brain calcification (PFBC). Using Sanger sequencing, we screened XPR1 in 18 unrelated patients with PFBC and no SLC20A2, PDGFB, or PDGFRB mutation. XPR1 variants were tested in an in vitro physiological complementation assay and patient blood cells were assessed ex vivo for phosphate export. We identified a novel c.260T > C, p.(Leu87Pro) XPR1 variant in a 41-year-old man complaining of micrographia and dysarthria and demonstrating mild parkinsonism, cerebellar ataxia and executive dysfunction. Brain (123)I-Ioflupane scintigraphy showed marked dopaminergic neuron loss. Peripheral blood cells from the patient exhibited decreased phosphate export. XPR1 in which we introduced the mutation was not detectable at the cell surface and did not lead to phosphate export. These results confirm that loss of XPR1-mediated phosphate export function causes PFBC, occ...
Nature genetics, Jan 4, 2015
Primary familial brain calcification (PFBC) is a neurological disease characterized by calcium ph... more Primary familial brain calcification (PFBC) is a neurological disease characterized by calcium phosphate deposits in the basal ganglia and other brain regions and has thus far been associated with SLC20A2, PDGFB or PDGFRB mutations. We identified in multiple families with PFBC mutations in XPR1, a gene encoding a retroviral receptor with phosphate export function. These mutations alter phosphate export, implicating XPR1 and phosphate homeostasis in PFBC.
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Papers by uriel corona sanchez