5,362 research outputs found
CSF/serum quotient graphs for the evaluation of intrathecal C4 synthesis
<p>Abstract</p> <p>Background</p> <p>Cerebrospinal fluid (CSF)/serum quotient graphs have been used previously to determine local synthesis in brain of immunoglobulins and C<sub>3 </sub>complement component. The aim of this study was to use the same technique to construct quotient graphs, or Reibergrams, for the beta globulin C<sub>4 </sub>and to evaluate the method for assessing intrathecal synthesis in neurological disease.</p> <p>Methods</p> <p>The constants in the previously-defined Reibergram for immunoglobulin IgA were used to calculate the CSF/serum quotient for C<sub>4</sub>. CSF and serum were analyzed for C<sub>4</sub>, IgA and albumin from a total of 12 patients with meningoencephalitis caused by encapsulated microorganisms and 10 subjects without infections or inflammatory neurological disease, some of which had dysfunction of the blood-CSF barrier,</p> <p>Results</p> <p>The formula and C<sub>4 </sub>Reibergram with the constants previously found for IgA, determined the intrathecal C<sub>4 </sub>synthesis in CSF. The intrathecal C<sub>4 </sub>fraction in CSF (C<sub>4 </sub>loc in mg/l) was compared to the C<sub>4</sub>-Index (fraction of CSF: serum for C <sub>4</sub>/fraction of CSF: serum for albumin). There was a significant correlation between the two formulae. The CSF/Serum quotient graph was superior for detecting intrathecal synthesis of C<sub>4 </sub>under variable conditions of blood-CSF barrier permeability.</p> <p>Conclusion</p> <p>The C<sub>4 </sub>Reibergram can be used to quantify the intrathecal synthesis of this component of the complement system in different infectious diseases of the central nervous system and is especially useful for patients with blood-brain barrier dysfunction.</p
Coercive field of ultrathin PbZr0.52Ti0.48O3 epitaxial films
The polarization reversal in single-crystalline ferroelectric films has been investigated experimentally and theoretically. The hysteresis loops were measured for Pb(Zr0.52Ti0.48)O-3 films with thicknesses ranging from 8 to 250 nm. These films were grown epitaxially on SrRuO3 bottom electrodes deposited on SrTiO3 substrates. The measurements using Pt top electrodes showed that the coercive field E-c increases drastically as the film becomes thinner, reaching values as high as E(c)approximate to1200 kV/cm. To understand this observation, we calculated the thermodynamic coercive field E-th of a ferroelectric film as a function of the misfit strain S-m in an epitaxial system and showed that E-th strongly depends on S-m. However, the coercive field of ultrathin films, when measured at high frequencies, exceeds the calculated thermodynamic limit. Since this is impossible for an intrinsic coercive field E-c, we conclude that measurements give an apparent E-c rather than the intrinsic one. An enormous increase of apparent coercive field in ultrathin films may be explained by the presence of a conductive nonferroelectric interface layer. (C) 2003 American Institute of Physics
Relationship between Dyslipidemia and Physical Activity in Mexican Children
Purpose: The purpose of this research was to determine the relationship between physical activity and lipid levels in children 10 to 13 years of age living in Durango, Mexico. Method: Cross-sectional study performed in 823 children (n=428, 52% boys; n=395, 48% girls) enrolled in nine elementary schools. Physical activity was monitored in two ways: a) a questionnaire was used to obtain information about physical activity done in the previous week, and b) steps were counted for 24 hours with a Yamax SW-200 pedometer. A subsample of 425 children provided serum samples to determine total-cholesterol (TC), HDL-cholesterol (HDL-C), LDL-cholesterol (LDL-C) and triglycerides (TG). Results: Over half (52.9%) participated in a sports team inside or outside of school; most (90.9%) reported one sport, with few (9.1%) reporting 2-3 sports. The most commonly reported vigorous PA was: soccer (33%), basketball (24%), jogging (8-12 km/h) (23%), volleyball (17%) and others (3%). Those who participated in a sports team had higher levels of HDL-C and lower TG. Participation in 2 or 3 sports reduced TG levels just over 20%. Boys who reported 30 minutes or more per day of vigorous activity had lower triglyceride levels than those who reported less (p = 0.020). Boys accumulated significantly more steps per day (m=17,030 ± 6444) than girls (m=12,991± 5316; p \u3c 0.001). The prevalence of lipid abnormalities was higher in children with fewer steps. Hypercholesterolemia was lower in boys with the highest number of steps (p = 0.044), in girls the differences were not statistically significant. Hypertriglyceridemia in both sexes was lower in the group with the highest number of steps (
The constant-velocity highly collimated outflows of the planetary nebula He 2-90
We present high-dispersion echelle spectroscopic observations and a
narrow-band [N II] image of the remarkable jet-like features of He 2-90. They
are detected in the echelle spectra in the H-alpha and [N II] lines but not in
other nebular lines. The [N II]/H-alpha ratio is uniformly high, ~1. The
observed kinematics reveals bipolar collimated outflows in the jet-like
features and shows that the southeast (northwest) component expands towards
(away from) the observer at a remarkably constant line-of-sight velocity,
26.0+-0.5 km/s. The observed expansion velocity and the opening angle of the
jet-like features are used to estimate an inclination angle of ~5 degrees with
respect to the sky plane and a space expansion velocity of ~290 km/s. The
spectrum of the bright central nebula reveals a profusion of Fe lines and
extended wings of the H-alpha line, similar to those seen in symbiotic stars
and some young planetary nebulae that are presumed to host a mass-exchanging
binary system. If this is the case for He 2-90, the constant velocity and
direction of the jets require a very stable dynamic system against precession
and warping.Comment: 8 pages (emulate ApJ), 5 figure, 1 tabl
Eficacia y seguridad en condiciones clínicas reales del raltegravir en un hospital de referencia del seguro social peruano
Introduction: Rategravir belongs to integrase inhibitors, being demonstrated and approved by several clinical trials as a powerful and safe antiretroviral drug for the treatment of patients infected with human immunodeficiency virus (HIV), with good tolerance and low toxicity, including in the third line or rescue scheme and it starts when the first and second lineas schemes have failed.Objective: To evaluate the efficacy and safety in real clinical conditions of the use of Raltegravir within the HAART schemes in patients with HIV infection in a reference hospital of social insurance in Peru.Methods: A retrospective observational study was performed in patients with a diagnosis of HIV infection who started treatment within the TARGA scheme based on Raltegravir with follow-up and control at 6 months. We presented summary measures of frequencies and percentages for the qualitative variables, as well as means and standard deviation for the quantitative variables based on the results of the normality tests. The data was processed and analyzed in the statistical software SPSS version 22.Results: The male gender was the most affected with 76% (n = 119) of the total. The most frequent age range was between 45 to 55 years (25.4%, n = 40). The most frequent comorbidities were Diabetes mellitus and arterial hypertension, with exponential reduction in viral load and elevation of CD4 lymphocyte levels.Conclusion: Raltegravir is effective for the treatment of HIV patients.Introducción: El Rategravir pertenece a los inhibidores de integrasas, quedando demostrado y aprobado por diversos ensayos clínicos como un potente antirretroviral seguro y eficaz para el tratamiento de pacientes infectados con el virus de inmunodeficiencia humana (VIH), con buena tolerancia y baja toxicidad, incluyéndose en el esquema de tercera línea o rescate y se inicia cuando los esquemas de primera y segunda línea han fracasado.Objetivo: Evaluar la eficacia y seguridad en condiciones clínicas reales del uso de Raltegravir dentro de los esquemas de la Terapia Antiretroviral de Gran Actividad (TARGA) en pacientes con infección por VIH en un hospital de referencia del seguro social en Perú.Métodos: Se realizó un estudio observacional retrospectivo en pacientes con diagnóstico de infección por VIH que iniciaron tratamiento dentro del esquema TARGA basados en Raltegravir con seguimiento y control a los 6 meses. Se presentaron medidas de resumen de frecuencias y porcentajes para las variables cualitativas, así como medias y desviación estándar para las variables cuantitativas en base a los resultados de las pruebas de normalidad. Los datos fueron procesados y analizados en el software estadístico SPSS versión 22.Resultados: El género masculino fue el más afectado con un 76%(n=119) del total. El rango de edad más frecuente fue el comprendido entre los 45 a 55 años (25,4%; n=40). Las comorbilidades más frecuentes fueron Diabetes mellitus e Hipertensión arterial, con reducción exponencial de la carga viral y elevación de los niveles de linfocitos CD4.Conclusión: El Raltegravir es eficaz para el tratamiento de pacientes VIH
Midwave infrared InAs/GaSb superlattice photodiode with a dopant-free p–n junction
Midwave infrared (MWIR) InAs/GaSb superlattice (SL) photodiode with a dopant-free p–n junction was fabricated by molecular beam epitaxy on GaSb substrate. Depending on the thickness ratio between InAs and GaSb layers in the SL period, the residual background carriers of this adjustable material can be either n-type or p-type. Using this flexibility in residual doping of the SL material, the p–n junction of the device is made with different non-intentionally doped (nid) SL structures. The SL photodiode processed shows a cut-off wavelength at 4.65 μm at 77 K, residual carrier concentration equal to 1.75 × 1015 cm−3, dark current density as low as 2.8 × 10−8 A/cm2 at 50 mV reverse bias and R0A product as high as 2 × 106 Ω cm2. The results obtained demonstrate the possibility to fabricate a SL pin photodiode without intentional doping the pn junction
Replication stress caused by low MCM expression limits fetal erythropoiesis and hematopoietic stem cell functionality
Replicative stress during embryonic development influences ageing and
predisposition to disease in adults. A protective mechanism against
replicative stress is provided by the licensing of thousands of origins
in G1 that are not necessarily activated in the subsequent S-phase.
These `dormant' origins provide a backup in the presence of stalled
forks and may confer flexibility to the replication program in specific
cell types during differentiation, a role that has remained unexplored.
Here we show, using a mouse strain with hypomorphic expression of the
origin licensing factor mini-chromosome maintenance (MCM)3 that limiting
origin licensing in vivo affects the functionality of hematopoietic stem
cells and the differentiation of rapidly-dividing erythrocyte
precursors. Mcm3-deficient erythroblasts display aberrant DNA
replication patterns and fail to complete maturation, causing lethal
anemia. Our results indicate that hematopoietic progenitors are
particularly sensitive to replication stress, and full origin licensing
ensures their correct differentiation and functionality.We thank members of our laboratories for helpful discussions, Marcos
Malumbres (CNIO) for advice on the design of the Mcm3-Lox allele, Isabel
Blanco for her administrative help with mouse work and Soraya Ruiz for
excellent handling of the mouse colony in J.M.'s group. Research was
supported by the Spanish Ministry of Economy and Competitiveness (grants
BFU2013-49153-P and Consolider-Ingenio CSD2007-00015 to J.M.,
SAF2011-23753 to O.F.-C., BFU2012-35892 to J.I.) and RO1 HL092471 to
E.P., S.A. was the recipient of an EMBO short-term fellowship to visit
E.P.'s laboratory at UCSF. We are grateful to Manuel Serrano (CNIO),
Almudena Ramiro (CNIC) and Arkaitz Ibarra (The Salk Institute, USA) for
useful comments on the manuscript.S
The effect of LEDs on biomass and phycobiliproteins production in thermotolerant oscillatoria sp
Featured Application: The selection of LEDs wavelength, intensity, and light: Dark cycle positively enhances the biomass production and phycocyanin synthesis in Oscillatoria sp. This study evaluates the role of different LED lights (white, blue/red), intensity (µmol m−2 s−1), and photoperiod in the production of biomass and phycocyanin-C, allophycocyanin and phycoerythrin (C-PC, APC, and PE respectively) from a novel thermotolerant strain of Oscillatoria sp. Results show that a mixture of white with blue/red LEDs can effectively double the biomass concentration up to 1.3 g/L, while the concentration of the selected phycobiliproteins increased proportionally to biomass. Results also indicate that high light intensities (>120 µmol m−2 s−1) can diminish the final concentration of C-PC, APC, and PE, significantly reducing the overall biomass produced. Finally, the photoperiod analysis showed that longer light exposure times (18:6 h) improved both biomass and phycobiliproteins concentration. These results demonstrate that the application of LEDs to produce a novel strain of Oscillatoria sp can double the biomass concentration, and the photoperiod regulation can eventually enhance the final concentration of specific phycobiliproteins such as APC and PE
Signaling-Biased and Constitutively Active Dopamine D2 Receptor Variant
A dopamine D2 receptor mutation was recently identified in a family with a novel hyperkinetic movement disorder. Compared to the wild type D2 receptor, the novel allelic variant D2-I212F activates a Gαi1β1γ2 heterotrimer with higher potency and modestly enhanced basal activity in human embryonic kidney (HEK) 293 cells and has decreased capacity to recruit arrestin3. We now report that omitting overexpressed G protein-coupled receptor kinase-2 (GRK2) decreased the potency and efficacy of quinpirole for arrestin recruitment. The relative efficacy of quinpirole for arrestin recruitment to D2-I212F compared to D2-WT was considerably lower without overexpressed GRK2 than with added GRK2. D2-I212F exhibited higher basal activation of GαoA than Gαi1 but little or no increase in the potency of quinpirole relative to D2-WT. Other signs of D2-I212F constitutive activity for G protein-mediated signaling, in addition to basal activation of Gαi/o, were enhanced basal inhibition of forskolin-stimulated cyclic AMP accumulation that was reversed by the inverse agonists sulpiride and spiperone and a ∼4-fold increase in the apparent affinity of D2-I212F for quinpirole, determined from competition binding assays. In mouse midbrain slices, inhibition of tonic current by the inverse agonist sulpiride in dopamine neurons expressing D2-I212F was consistent with our hypothesis of enhanced constitutive activity and sensitivity to dopamine relative to D2-WT. Molecular dynamics simulations with D2 receptor models suggested that an ionic lock between the cytoplasmic ends of the third and sixth α-helices that constrains many G protein-coupled receptors in an inactive conformation spontaneously breaks in D2-I212F. Overall, these results confirm that D2-I212F is a constitutively active and signaling-biased D2 receptor mutant and also suggest that the effect of the likely pathogenic variant in a given brain region will depend on the nature of G protein and GRK expression
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