Portada

Fotografia: Joan Sarria

Portada

Fotografia de portada: Campanar de Sant Corneli i Sant Cebrià Autor: Joan Sarria

Discrete Choice Models with Random Parameters in R: The Rchoice Package

Rchoice is a package in R for estimating models with individual heterogeneity for both cross-sectional and panel (longitudinal) data. In particular, the package allows binary, ordinal and count response, as well as continuous and discrete covariates. Individual heterogeneity is modeled by allowing the parameter associated with each observed variable (e.g., its coefficient) to vary randomly across individuals according to some pre-specified distribution. Simulated maximum likelihood method is implemented for the estimation of the moments of the distributions. In addition, functions for plotting the conditional individual-specific coefficients and their confidence interval are provided. This article is a general description of Rchoice and all functionalities are illustrated using real databases

Un paller a Tavertet i Puigdelaguardiola al fons.

Fotografia de portada Autor: Joan Sarria

Random Parameters and Spatial Heterogeneity using Rchoice package in R

This study focus on models with spatially varying coefficients using simulations.  As shown by Sarrias (2019), this modeling strategy is intended to complement the existing approaches by using variables at micro level and by adding flexibility and realism to the potential domain of the coefficient on the geographical space. Spatial heterogeneity is modelled by allowing the parameters associated with each observed variable to vary “randomly” across space according to some distribution. To show the main advantages of this modeling strategy, the Rchoice package in R is used

Validation and optimization of omnipolar technology in ventricular ablation procedures

Treballs Finals de Grau d'Enginyeria Biomèdica. Facultat de Medicina i Ciències de la Salut. Universitat de Barcelona. Curs: 2022-2023. Tutora/Directora: Garre, Paz, Vázquez, SaraThis project aims to improve the effectiveness of ventricular tachycardia (VT) ablation procedures by accurately mapping the reentrant channels responsible for the arrhythmia. The study compares different mapping techniques, including bipolar, orthogonal, and omnipolar signals, using the HD Grid catheter and the EnSite X system. Electro-Anatomical Maps (EAMs) created through these techniques are evaluated for their accuracy in identifying channels by comparing them with Cardiac Magnetic Resonance (CMR) maps. The project's findings demonstrate that the omnipolar map, optimized with specific thresholds, exhibits higher correlation with the CMR map, offering reliable and accurate information about the cardiac tissue. Moreover, the comparisons are done also between layers of the ventricle’s heart, the layer 50 (which is an average of the pixels of layers 10- 50) is identified as the most informative layer, and expanded maximum thresholds allow for a comprehensive understanding of ventricular tissue. The results validate the superiority of the omnipolar technology and emphasize the need for further research and collaboration to advance the field of VT ablation procedures

Caracterización in vitro de nanopartículas dirigidas a marcadores de Cancer Stem Cells en líneas celulares de cáncer microcítico de pulmón

El cáncer de pulmón es la principal causa de muerte por cáncer en todo el mundo. A pesar de las diferentes terapias comúnmente utilizadas para tratar el cáncer de pulmón, el pronóstico de los pacientes sigue siendo pobre. Diversos trabajos han propuesto que muchos tipos de cáncer, incluyendo el cáncer de pulmón, pueden ser promovidos por las células madre del cáncer (CSC, del inglés Cancer Stem Cell). Las CSCs son un subconjunto de células indiferenciadas con la capacidad de iniciar la formación de tumores, proliferar y diferenciarse ampliamente. Se piensa que el crecimiento y / o la recurrencia del cáncer puede estar impulsado por este grupo de células. También están involucradas en las resistencias a la radioterapia y la quimioterapia. Los sistemas de liberación de fármacos a nanoescala están evolucionando rápidamente y pueden ofrecer un enfoque innovador para superar la resistencia de las CSCs a los fármacos así como reducir la frecuencia de recidivas. Recientemente, las estrategias basadas en nanopartículas han demostrado un aumento de la eficacia terapéutica y la reducción de los efectos secundarios adversos, en comparación con los métodos terapéuticos clásicos. Varios estudios han respaldado a la bomba ABCG2, al receptor CXCR4 y al CD44 como posibles marcadores de CSC en el cáncer microcítico de pulmón. Los objetivos directos de este trabajo son determinar la presencia de estos marcadores en la superficie de las distintas líneas celulares pulmonares, estudiar la capacidad y especificidad de unión de las nanopartículas a las diferentes dianas y caracterizar la internalización de dichas nanopartículas, con el fin de desarrollar un sistema de direccionamiento de fármacos que eliminaría selectivamente las CSCs.Lung cancer is the leading cause of cancer death worldwide. Although many therapies are commonly used to treat lung cancer, the prognosis remains poor. Several studies have suggested that many types of cancer, including lung cancer, can be promoted by cancer stem cells (CSC). CSCs are a subset of undifferentiated with the ability to initiate the tumor, proliferation and differentiation. It is thought that growth and / or recurrence of cancer may be driven by this group of cells. They are also involved in drug resistance. The nanoscale drug delivery systems are evolving rapidly and can offer an innovative approach to overcome drug resistance of the CSC and reduce the frequency of recurrences. Recently, nanoparticles based strategies have demonstrated increased therapeutic efficacy and reduced adverse side effects, compared with those of traditional therapeutic methods. Several studies have supported the ABCG2 pump, the CXCR4 receptor and CD44 as potential markers of CSCs in small cell lung cancer. The objectives of this study are to determine the presence of these markers on the surface of different lung cell lines, and to study binding specificity of nanoparticles to different targets and characterizing their internalization, in order to develop a drug targeting system which selectively eliminate CSCs.Universidad de Sevilla. Máster en Investigación Médica: clínica y experimenta

GMM Estimators for Binary Spatial Models in R

Despite the huge availability of software to estimate cross-sectional spatial models, there are only few functions to estimate models dealing with spatial limited dependent variable. This paper fills this gap introducing the new R package spldv. The package is based on generalized methods of moment (GMM) estimators and includes a series of one- and two-step estimators based on different choices of the weighting matrix for the moments conditions in the first step, and different estimators for the variance-covariance matrix of the estimated coefficients. An important feature of spldv is that users can estimate the spatial Durbin model and compute the direct, indirect, and total effects in a friendly and flexible way

Multinomial Logit Models with Continuous and Discrete Individual Heterogeneity in R: The gmnl Package

This paper introduces the package gmnl in R for estimation of multinomial logit models with unobserved heterogeneity across individuals for cross-sectional and panel (longitudinal) data. Unobserved heterogeneity is modeled by allowing the parameters to vary randomly over individuals according to a continuous, discrete, or discrete-continuous mixture distribution, which must be chosen a priori by the researcher. In particular, the models supported by gmnl are the multinomial or conditional logit, the mixed multinomial logit, the scale heterogeneity multinomial logit, the generalized multinomial logit, the latent class logit, and the mixed-mixed multinomial logit. These models are estimated using either the maximum likelihood estimator or the maximum simulated likelihood estimator. This article describes and illustrates with real databases all functionalities of gmnl, including the derivation of individual conditional estimates of both the random parameters and willingness-to-pay measures

CD5L promotes M2 macrophage polarization through autophagy-mediated upregulation of ID3

CD5L (CD5 molecule-like) is a secreted glycoprotein that controls key mechanisms in inflammatory responses, with involvement in processes such as infection, atherosclerosis, and cancer. In macrophages, CD5L promotes an anti-inflammatory cytokine profile in response to TLR activation. In the present study, we questioned whether CD5L is able to influence human macrophage plasticity, and drive its polarization toward any specific phenotype. We compared CD5L-induced phenotypic and functional changes to those caused by IFN/LPS, IL4, and IL10 in human monocytes. Phenotypic markers were quantified by RT-qPCR and flow cytometry, and a mathematical algorithm was built for their analysis. Moreover, we compared ROS production, phagocytic capacity, and inflammatory responses to LPS. CD5L drove cells toward a polarization similar to that induced by IL10. Furthermore, IL10- and CD5L-treated macrophages showed increased LC3-II content and colocalization with acidic compartments, thereby pointing to the enhancement of autophagy-dependent processes. Accordingly, siRNA targeting ATG7 in THP1 cells blocked CD5L-induced CD163 and Mer tyrosine kinase mRNA and efferocytosis. In these cells, gene expression profiling and validation indicated the upregulation of the transcription factor ID3 by CD5L through ATG7. In agreement, ID3 silencing reversed polarization by CD5L. Our data point to a significant contribution of CD5L-mediated autophagy to the induction of ID3 and provide the first evidence that CD5L drives macrophage polarization.Peer ReviewedPostprint (published version