Risk factors associated to hospital mortality in patients with acute kidney injury on hemodialysis.

INTRODUCTION: The worldwide incidence of acute kidney injury is 18% and the overall hospital mortality can rise above 50%. In Peru, there are few series about mortality of acute kidney injury in hemodialysis patients. OBJECTIVES: To identify risk factors associated to hospital mortality of acute kidney injury in hemodialysis patients. METHODS: This is a retrospective cohort of patients with acute kidney injury in hemodialysis of Hospital Nacional Edgardo Rebagliati Martins gathered between January 2013 and December 2015. The sample size was 154 patients which allowed a power of 80% and a CI of 95%. ICD-10 codes were used to identify medical records of patients with acute kidney injury (N.17) and hemodialysis (Z.49). The independent variable was oliguria, and the primary outcome was hospital mortality. Poisson regression was used for multivariate analysis. RESULTS: We identified a total of 285 patients; 212 medical records were analyzed and 44 were excluded. Out of the 168 medical records, 129 belonged to living patients and 39 to deceased ones. The overall mortality incidence was 17.2%. The principal etiologies of acute kidney injury while in hemodialysis were sepsis (39.2%), and severe dehydration (10.8%). In the adjusted model, the risk factors associated to hospital mortality of acute kidney injury while in hemodialysis were elevated serum lactate (RR 1.09), elevated serum potassium (RR 0.93), and mean arterial pressure (RR 0.97). CONCLUSIONS: Lactate is an objective parameter that can predict prognosis and contributes to a better management of acute kidney injury in hemodialysis patients. INTRODUCCIÓN: La incidencia de insuficiencia renal aguda a nivel mundial es 18% y la mortalidad intrahospitalaria puede alcanzar más del 50%. En Perú, existen escasos estudios acerca de la mortalidad en pacientes con insuficiencia renal aguda en hemodiálisis. OBJETIVOS: Identificar los factores de riesgo asociados a mortalidad intrahospitalaria en pacientes con insuficiencia renal aguda en hemodiálisis. MÉTODOS: Es una cohorte retrospectiva, en la cual se estudió a los pacientes con insuficiencia renal aguda en hemodiálisis en el Hospital Nacional Edgardo Rebagliati Martins entre enero de 2013 y diciembre de 2015. Se halló un tamaño de muestra de 154 pacientes con una potencia de 80%, y un intervalo de confianza de 95%. Se utilizaron los códigos de la Clasificación Internacional de Enfermedades-10 para identificar las historias clínicas de pacientes con insuficiencia renal aguda (N.17) y hemodiálisis (Z.49). La variable independiente fue oliguria y la variable dependiente fue mortalidad intrahospitalaria. Para el análisis multivariado, se utilizó regresión de Poisson. RESULTADOS: El universo fue de 285 pacientes. Se revisaron 212 historias clínicas y se excluyeron 44. De las 168 historias clínicas estudiadas, 129 pertenecían a pacientes vivos y 39 a fallecidos. La incidencia de mortalidad fue de 17,2%. Las principales causas de insuficiencia renal aguda en hemodiálisis fueron sepsis (39,2%) y deshidratación severa (10,8%). En el modelo ajustado, los factores de riesgo asociados a mortalidad intrahospitalaria de insuficiencia renal aguda en hemodiálisis fueron lactato (riesgo relativo 1,09), potasio (riesgo relativo 0,93), y presión arterial media (riesgo relativo 0,97). CONCLUSIONES: El lactato es un parámetro objetivo que permite predecir el pronóstico y contribuye a un mejor manejo de los pacientes con insuficiencia renal aguda en hemodiálisis.Revisión por paresRevisión por pare

On solvable models of type IIB superstring in NS-NS and R-R plane wave backgrounds

We consider type IIB string in the two plane-wave backgrounds which may be interpreted as special limits of the AdS_3 x S^3 metric supported by either the NS-NS or R-R 3-form field. The NS-NS plane-wave string model is equivalent to a direct generalization of the Nappi-Witten model, with its spectrum being similar to that of strings in constant magnetic field. The R-R model can be solved in the light-cone gauge, where the Green-Schwarz action describes 4 massive and 4 massless copies of free bosons and fermions. We find the spectra of the two string models and study the asymptotic density of states. We also discuss a more general class of exactly solvable plane-wave models with reduced supersymmetry which is obtained by adding twists in two spatial 2-planes.Comment: 36 pages, harvmac. v2: discussion of equivalence of the supergravity parts of the spectra of the NS-NS and R-R models added in sect.5.3; v3: added remark on periodicity of the NS-NS spectrum; v4: minor correction in sect.6.

Supersymmetric solutions of gauged five-dimensional supergravity with general matter couplings

We perform the characterization program for the supersymmetric configurations and solutions of the $\mathcal{N}=1$, $d=5$ Supergravity Theory coupled to an arbitrary number of vectors, tensors and hypermultiplets and with general non-Abelian gaugins. By using the conditions yielded by the characterization program, new exact supersymmetric solutions are found in the $SO(4,1)/SO(4)$ model for the hyperscalars and with $SU(2)\times U(1)$ as the gauge group. The solutions also content non-trivial vector and massive tensor fields, the latter being charged under the U(1) sector of the gauge group and with selfdual spatial components. These solutions are black holes with $AdS_2 \times S^3$ near horizon geometry in the gauged version of the theory and for the ungauged case we found naked singularities. We also analyze supersymmetric solutions with only the scalars $\phi^x$ of the vector/tensor multiplets and the metric as the non-trivial fields. We find that only in the null class the scalars $\phi^x$ can be non-constant and for the case of constant $\phi^x$ we refine the classification in terms of the contributions to the scalar potential.Comment: Minor changes in wording and some typos corrected. Version to appear in Class. Quantum Grav. 38 page

Aplicación del enfoque descendente para la enseñanza de Redes de Computadoras, un estudio comparativo

El enfoque ascendente para la enseñanza de redes fue el que habitualmente se utilizó en las carreras tanto de informática como de ingeniería. Los libros más citados en la bibliografía siguen este enfoque. Algunos autores como Jim Kurose y Keith Ross cuestionaron esto y propusieron el sentido descendente, el cual comienza por las capas superiores para luego adentrarse en los detalles de las capas más bajas, tratando de aprovechar los conocimientos previos de los estudiantes en el uso de aplicaciones de red. En las carreras tradicionalmente se ha utilizado en enfoque ascendente y en particular en la UNSJ, UNSa y UCSAL actualmente se utiliza este nuevo enfoque. Por ello el presente trabajo presenta las experiencias, conclusiones, sugerencias, junto con un estudio comparativo de otras carreras fuera del país, con respecto al modelo de enseñanza de asignaturas sobre Redes de Computadoras.V Workshop de Innovación en Educación en Informática (WIEI).Red de Universidades con Carreras en Informática (RedUNCI

Aplicación del enfoque descendente para la enseñanza de Redes de Computadoras, un estudio comparativo

El enfoque ascendente para la enseñanza de redes fue el que habitualmente se utilizó en las carreras tanto de informática como de ingeniería. Los libros más citados en la bibliografía siguen este enfoque. Algunos autores como Jim Kurose y Keith Ross cuestionaron esto y propusieron el sentido descendente, el cual comienza por las capas superiores para luego adentrarse en los detalles de las capas más bajas, tratando de aprovechar los conocimientos previos de los estudiantes en el uso de aplicaciones de red. En las carreras tradicionalmente se ha utilizado en enfoque ascendente y en particular en la UNSJ, UNSa y UCSAL actualmente se utiliza este nuevo enfoque. Por ello el presente trabajo presenta las experiencias, conclusiones, sugerencias, junto con un estudio comparativo de otras carreras fuera del país, con respecto al modelo de enseñanza de asignaturas sobre Redes de Computadoras.V Workshop de Innovación en Educación en Informática (WIEI).Red de Universidades con Carreras en Informática (RedUNCI

Aplicación del enfoque descendente para la enseñanza de Redes de Computadoras, un estudio comparativo

El enfoque ascendente para la enseñanza de redes fue el que habitualmente se utilizó en las carreras tanto de informática como de ingeniería. Los libros más citados en la bibliografía siguen este enfoque. Algunos autores como Jim Kurose y Keith Ross cuestionaron esto y propusieron el sentido descendente, el cual comienza por las capas superiores para luego adentrarse en los detalles de las capas más bajas, tratando de aprovechar los conocimientos previos de los estudiantes en el uso de aplicaciones de red. En las carreras tradicionalmente se ha utilizado en enfoque ascendente y en particular en la UNSJ, UNSa y UCSAL actualmente se utiliza este nuevo enfoque. Por ello el presente trabajo presenta las experiencias, conclusiones, sugerencias, junto con un estudio comparativo de otras carreras fuera del país, con respecto al modelo de enseñanza de asignaturas sobre Redes de Computadoras.V Workshop de Innovación en Educación en Informática (WIEI).Red de Universidades con Carreras en Informática (RedUNCI

All the supersymmetric solutions of N=1,d=5 ungauged supergravity

We classify the supersymmetric solutions of ungauged N=1 d=5 SUGRA coupled to vector multiplets and hypermultiplets. All the solutions can be seen as deformations of solutions with frozen hyperscalars. We show explicitly how the 5-dimensional Reissner-Nordstrom black hole is deformed when hyperscalars are living on SO(4,1)/SO(4) are turned on, reducing its supersymmetry from 1/2 to 1/8. We also describe in the timelike and null cases the solutions that have one extra isometry and can be reduced to N=2,d=4 solutions. Our formulae allows the uplifting of certain N=2,d=4 black holes to N=1,d=5 black holes on KK monopoles or to pp-waves propagating along black strings.Comment: Some typos fixed and some paragraphs improved. 44 pages, Latex 2e file, no figures. Version to be published in JHE

Chronic Hypoxia Alters Vasoconstrictive Responses of Femoral Artery in the Fetal Sheep

The purpose of this study was to determine if mild hypoxia alters the responsiveness to vasoactive agents in the renal and the femoral arteries in the fetal sheep. Ten pregnant sheep were operated under halothane anesthesia at 116 to 124 days' gestation. A maternal tracheal catheter was placed for infusing compressed air (control group, n=5) or nitrogen (hypoxia group, n=5) starting on post operative day 6 and maintained for 5 days. Femoral and renal arteries were harvested from the fetus to study the constriction response to phenylephrine (PE 10-9 to 10-5 mol/L). To determine the involvement of nitric oxide as a modulator of vessel constriction, N-nitro-L-arginine methyl ester (L-NAME) was used at a concentration of 10-4 mol/L in parallel chambers. In the hypoxia group, maternal Pao2 significantly decreased from a baseline of 110.4±1.4 to 80.5±1.6 (mmHg, p<0.01), fetal Pao2 significantly decreased from a baseline of 20.9±0.3 to 15.5±0.1 (mmHg, p<0.01). Hypoxia was associated with a significant increase in PE maximal response in the absence (184.5±6.6 vs. 146.2±4.3) and presence (166.9±6.3 vs. 145.0±4.5) of L-NAME, and a decrease in EC50 in the absence (6.0±1.1 vs. 27.0±4.1) of L-NAME of femoral arteries. However, there were no significant differences in PE maximal response and EC50 in the absence and presence of L-NAME of renal arteries. We concluded that mild chronic hypoxia seems to increase the fetal femoral artery response to PE, but not in the fetal renal artery. This observation is consistent with a redistribution of cardiac output away from the carcass

Invasive meningococcal disease in three siblings with hereditary deficiency of the 8th component of complement: Evidence for the importance of an early diagnosis

Deficiency of the eighth component of complement (C8) is a very rare primary immunodeficiency, associated with invasive, recurrent infections mainly caused by Neisseria species. We report functional and immunochemical C8 deficiency diagnosed in three Albanian siblings who presented with severe meningococcal infections at the age of 15 years, 4 years and 17 months, respectively. The youngest suffered serious complications (necrosis of fingers and toes requiring amputation). METHODS: Functional activity of the classical, alternative and mannose-binding lectin complement pathways was measured in serum from the 3 siblings and their parents (37-year-old woman and 42-year-old man). Forty healthy subjects (20 males and 20 females aged 4-38 years) served as normal controls. Serum complement factors were measured by haemolytic assays and immunoblotting. Sequence DNA analysis of the C8B gene was performed. RESULTS: Analyses of the three complement pathways revealed no haemolytic activity and also absence of C8beta in serum samples from all three siblings. The genetic analysis showed that the three siblings were homozygous for the p.Arg428* mutation in the C8B gene on chromosome 1p32 (MIM 120960). The parents were heterozygous for the mutation and presented normal complement activities. A 2-year follow-up revealed no further infective episodes in the siblings after antibiotic prophylaxis and meningococcal vaccination. CONCLUSIONS: Complement deficiencies are rare and their occurrence is often underestimated. In presence of invasive meningococcal infection, we highlight the importance of complement screening in patients and their relatives in order to discover any genetic defects which would render necessary prophylaxis to prevent recurrent infections and severe complications