La regulación del transporte de L-arginina vía HCAT-1 por insulina involucra activación diferencial de los subtipos A y B de receptores de insulina y receptores de adenosina en células endoteliales de vena umbilical humana de diabetes gestacional

Tesis descargada desde el repositorio de la Pontificia Universidad Católica de Chile: https://repositorio.uc.cl/handle/11534/4954Diabetes gestacional (DG) aumenta el transporte de L-arginina en la macrocirculación de la placenta. Insulina activa receptores de insulina (IRs) los cuales estimulan el transporte de Larginina via transportadores de aminoácidos catiónicos tipo 1 humano (hCAT-1) y la síntesis de óxido nítrico en células endoteliales de la vena umbilical humana (HUVEC) de embarazos normales, pero reduce el aumento inducido por DG sobre el transporte de L-arginina. Este efecto de insulina podría resultar de una expresión y activación diferencial de las isoformas A (IR-A) y B (IR-B) del receptor de insulina, involucrando mecanismos transcripcionales asociadas a la activación de la proteína específica 1 (Sp1). Como se ha propuesto que los efectos biológicos de insulina son regulados por receptores de adenosina, en este estudio se analizó si el aumento de la expresión y actividad de hCAT-1 causado por DG es bloqueado por insulina mediante activación diferencial de IR-A y/o IR-B, un mecanismo regulado por activación de receptores de adenosina en cultivos primarios de HUVEC. La actividad del transporte de L-arginina, la expresión de hCAT-1 y la unión de Sp1 están aumentadas en DG, efecto que es revertido por insulina. El efecto de insulina en DG requirió de la actividad de receptores de adenosina A1, un fenotipo que fue similar al observado en células knock-down para IR-B. En HUVEC normales, insulina aumentó la actividad del transporte de L-arginina, la expresión de hCAT-1 y la unión de Sp1 al promotor de SLC7A1, efectos que requirieron de la actividad del receptor de adenosina A2A. Sin embargo, el efecto de insulina fue bloqueado en HUVEC knock-down para IR-A y/o IRB. En conclusión, insulina revierte el efecto de diabetes gestacional vía IR-A sobre la actividad y expresión de hCAT-1, un mecanismo dependiente de receptores de adenosina A1 en HUVEC de DG. Sin embargo, insulina aumenta la actividad y expresión de hCAT-1, dependiendo de la actividad de receptores de adenosina A2A en HUVEC de embarazos normales.Gestational diabetes (GD) increases L-arginine transport in the placenta macrocirculation. Insulin activates insulin receptors (IRs) which stimulate L-arginine transport via human cationic amino acids transporters type 1 (hCAT-1) and nitric oxide synthesis in human umbilical vein endothelial cells (HUVEC) from normal pregnancies, but insulin reduces GD-increase Larginine transport. This insulin effect could be a result of differential expression and activation of the insulin receptor isoforms A (IR-A) and B (IR-B), involving transcriptional mechanisms associated with specific protein 1 (Sp1). As it has been proposed that the biological effects of insulin are regulated by adenosine receptors, in this study we analized whether insulin reverses GD-increase hCAT-1 activity and expression through differential IR-A and/or IR-B activation amd this mechanism is regulated by adenosine receptors in HUVEC. Herein, we demonstrated that L-arginine transport activity, hCAT-1 expression and Sp1-binding to promotor SLC7A1 are increased in GD, effects reverse by insulin. This insulin effect requires A1 adenosine receptor activity in GD, a phenotype that was similarly observed in cells knocked-down for IR-B. In normal HUVEC, insulin increased L-arginine activity, hCAT-1 expression and Sp1-binding to promotor SLC7A1, effects that required adenosine receptor A2A activity. However, these insulin effects were blocked in HUVEC knock-down for IR-A and/or IR-B. In conclusion, insulin via IR-A reverses the GD-increase in hCAT-1 activity and expression, a mechanism that is A1- adenosine receptor dependent in GD derived cells. However, insulin increases hCAT-1 activity and expression, through an A2A-adenosine receptor dependent mechanism in HUVEC from normal pregnancies

Marketing y turismo rural: una aplicación metodológica en la provincia de Córdoba

El presente estudio trata de determinar los factores que influyen la demanda del turismo rural en Andalucía, así como las estrategias de marketing que se han de aplicar para modificar dichos factores, todo ello complementado con una investigación de campo en la provincia de Córdoba donde se ha estimado a través de modelos econométricos la influencia de la publicidad en la demanda de turismo rural, así como el grado de satisfacción respecto al destino turístico escogido.In this study we try to establish the different factors which have an influence on the demand of rural tourism in Andalusia, and, at the same time, the marketing strategies we must put into practice in order to modify these factors. Moreover, we complement it with a field research in the province of Cordoba where some econometric models have estimated the influence of advertising on the demand of rural tourism and the degree of satisfaction related to the chosen tourist destination

Avión no tripulado de ensamble modular

Un vehículo aéreo no tripulado que comprende: un fuselaje; un tren de aterrizaje fijo; un ala principal unida a la parte superior trasera del fuselaje; un motor eléctrico en la parte frontal del fuselaje; una hélice conectada al motor; una viga de cola que se extienden hacia atrás desde el fuselaje; y un empenaje en T invertida unido al extremo posterior de la viga de cola; en donde el ala principal perfil alar GOE198, y una relación entre el coeficiente de sustentación y el coeficiente de arrastre (CD/CL) máximo igual o mayor a 75; en donde dicha relación entre el coeficiente de sustentación y el coeficiente de arrastre se encuentra entre un número de Reynolds de 200000 y 400000, - en donde el empenaje se une de forma removible al extremo posterior de la viga de cola y dicho empenaje comprende un estabilizador vertical en línea con dicha viga de cola, un timón de cola conectado con el módulo de control, un estabilizador horizontal y un timón de profundidad, en donde el estabilizador vertical y el estabilizador horizontal comprenden un perfil alar simétrico; y en donde el ala principal se une de forma removible mediante un acople deslizable en la viga central y acoples deslizables cercanos a los bordes de ataque y de fuga, junto con medios de aseguramiento para evitar el desensamble accidental del ala en vuelo.Modelo de Utilida

Experimental and theoretical characterization of the Zn - Zn bond in [Zn2(η5-C5Me5)2]

The existence and characterization of a bond between the Zn atoms in the recently synthesized complex [Zn2(5-C5Me5)2], as well as between Zn and ligand C atoms is firmly based on neutron diffraction and low-temperature X-ray synchrotron diffraction experiments. The multipolar analysis of the experimental electron density and its topological analysis by means of the Atoms in Molecules (AIM) approach reveals details of the Zn - Zn bond, such as its open-shell intermediate character (the results are consistent with a typical metal-metal single bond), as well as many other topological properties of the compound. Experimental results are also compared with theoretical ab initio calculations of the DFT (density functional theory) and MP2 (Mller-Plesset perturbation theory) electron densities, giving a coherent view of the bonding in the complex. For instance, charges calculated from the AIM approach applied to the atomic basin of each Zn atom are, on average, +0.72 e from both the experimental and the theoretical electron density, showing a moderate charge transfer from the metal, confirmed by the calculated topological indexes.Ministerio de Educación y Ciencia MAT2006-0199

Integrating curriculum-based dynamic assessment in computerized adaptive testing: Development and predictive validity of the EDPL-BAI battery on reading competence

In recent decades, there have been significant changes in the conceptualization of reading as well as in the perception of how this activity should be assessed. Interest in the analysis of reading processes has led to the emergence of new explanatory models based primarily on the contributions of cognitive psychology. In parallel, there have been notable advances in measurement procedures, especially in models based on Item Response Theory (IRT), as well as in the capacity and performance of specific software programs that allow data to be managed and analyzed. These changes have contributed significantly to the rise of testing procedures such as computerized adaptive tests (CATs), whose fundamental characteristic is that the sequence of items presented in the tests is adapted to the level of competence that the subject manifests. Likewise, the incorporation of elements of dynamic assessment (DA) as the prompts are gradually offered allows for obtaining information about the type and degree of support required to optimize the subject’s performance. In this sense, the confluence of contributions from DA and CATs offers a new possibility for approaching the assessment of learning processes. In this article, we present a longitudinal research developed in two phases, through which a computerized dynamic adaptive assessment battery of reading processes (EDPL-BAI) was configured. The research frame involved 1,831 students (46% girls) from 13 public schools in three regions of Chile. The purpose of this study was to analyze the differential contribution on reading competence of dynamic scores obtained in a subsample composed of 324 (47% girls) students from third to sixth grade after the implementation of a set of adaptive dynamic tests of morpho-syntactic processes. The results achieved in the structural equation modeling indicate a good global fit. Individual relationships show a significant contribution of calibrated score that reflects estimated knowledge level on reading competence, as well as dynamic scores based on the assigned value of graduated prompts required by the students. These results showed significant predictive values on reading competence and incremental validity in relation to predictions made by static criterion tests

New arthroscopic portal for performing tenotomy/tenodesis procedures on the long head of the biceps brachii tendon

AbstractBackgroundShoulder arthroscopy is the standard technique for performing procedures involving the intertubercular groove. Current techniques continue to produce excessive soft tissue manipulation and neurovascular injury.Materials and methodsA cross-sectional, observational and descriptive study was conducted on a cohort of 24 shoulders following the standard surgical protocol and using punch dissection. The neurovascular structures with risk of damage by the standard lateral portal were evaluated during the study to establish a secure area for a new arthroscopic portal. Finally, the safety of the new proposed site was evaluated.ResultsThe presence of 24 venous structures, with a mean diameter was 1.05mm (SD: 0.71) was documented. A tendency was observed in locating these structures in the lower half of the dissecting field for the left shoulders and a hypovascular area between the 7 and 10h circle dissected relative to the right shoulder. The new site was determined at a point 1.5cm anterolateral to the anterolateral border of the acromion at an angle of 60° to the horizontal axis of the acromion and towards the intertubercular groove of the humerus.ConclusionsThe methodology used in this study is innovative, reproducible and applicable for the study of all existing shoulder arthroscopic portals procedures, as well as any joint. The results provided by this study will be helpful for clinicians to improve tenotomy/tendon tenodesis procedures of the long head of the biceps brachii tendon

Conduits for myocardial revascularization grafts: the importance of morphology and imaging

The therapeutic options for patients with multivessel coronary artery disease, consist of pharmacological treatment, percutaneous coronary intervention and coronary artery bypass graft surgery. The ultimate goal of this surgery is to achieve complete revascularization with conduits that remain permeable for the remainder of the life of the patient. Some of the conduits used in this type of surgery, are the great saphenous vein, the internal thoracic artery, the radial artery and the ulnar artery. For a vascular conduit to be selected as a coronary revascularization graft, it must exhibit the following characteristics: sufficient length, lumen diameter and thickness of the vessel wall. It must also have minimal in situ ischemic consequences and an acceptable permeability over time of the conduit. Recent literatures of these conduits, as well as the importance of morphological and imaging studies are reviewed in this article

Mycobacterium tuberculosis TLR2 agonists LprA, LM and Man-LAM induce notch1 and socs3 transcription

"Mycobacterium tuberculosis employs a number of strategies to subvert host signaling events, leading to its persistence within macrophages. Upon infection, Mycobacterium bovis BCG induce the expression of suppressor of cytokine signaling 3 (socs3), in a Toll-like receptor 2 (TLR2)-Notch1-dependent manner. Purified phosphatidyl inositol di-mannosides (a TLR2 agonist) act as an inducer for the Notch1-socs3 pathway. This prompted us to analyze other TLR2 agonists seeking for additional molecules that may affect this pathway. We found that lipoprotein LprA, as well as glycolipids lipomannan (LM), and mannose-capped lipoarabinomannan (ManLAM) treatment of murine macrophages resulted in stimulation of notch1 and socs3 transcription.

No association of the dopamine D2 receptor genetic bilocus score (rs1800497/rs1799732) on food addiction and food reinforcement in Chilean adults

Purpose: Different systems regulate food intake. In the reward system, dopamine (DA) is the main neurotransmitter, and a variety of genetic variants (rs1799732 and rs1800497) are associated with addiction. Addiction is a highly polygenic disease, where each allelic variant adds a small amount of vulnerability. Polymorphisms rs1799732 and rs1800497 are associated with eating behavior and hedonic hunger, but links to food addiction remain unclear.Aim: To evaluate the association between the bilocus profile (rs1799732-rs1800497) of the dopaminergic pathway with food reinforcement and food addiction in Chilean adults.Methods: A cross-sectional study recruited a convenience sample of 97 obese, 25 overweight, and 99 normal-weight adults (18–35 years). Anthropometric measurements were performed by standard procedures and eating behavior was assessed using the: Food Reinforcement Value Questionnaire (FRVQ) and Yale Food Addiction scale (YFAS). The DRD2 genotypes were determined by TaqMan assays (rs1800497 and rs1799732). A bilocus composite score was calculated.Results: In the normal weight group, individuals who were heterozygous for the rs1977932 variant (G/del) showed higher body weight (p-value 0.01) and abdominal circumference (p-value 0.01) compared to those who were homozygous (G/G). When analyzing rs1800497, a significant difference in BMI was observed for the normal weight group (p-value 0.02) where heterozygous showed higher BMI. In the obese group, homozygous A1/A1 showed higher BMI in comparison to A1/A2 and A2/A2 (p-value 0.03). Also, a significant difference in food reinforcement was observed in the rs1800497, where homozygous for the variant (A1A1) show less reinforcement (p-value 0.01).In relation to the bilocus score in the total sample, 11% showed “very low dopaminergic signaling”, 24.4% were “under”, 49.7% showed “intermediate signaling”, 12.7% showed “high” and 1.4% showed “very high”. No significant genotypic differences were observed in food reinforcement and food addiction by bilocus score.Conclusions: The results indicate that the genetic variants rs1799732 and rs1800497 (Taq1A) were associated with anthropometric measurements but not with food addiction or food reinforcement in Chilean university students. These results suggest that other genotypes, such as rs4680 and rs6277, which affect DA signaling capacity through a multilocus composite score, should be studied. Level V: Evidence obtained from a cross-sectional descriptive study