Evaluación del efecto de la suplementación del antioxidante astaxantina y la administración de la vacuna tcvac1m en ratones balb/c infectados con trypanosoma cruzi

El conocimiento científico en torno al parásito Trypanosoma cruzi y la enfermedad de Chagas, en la actualidad permite diversificar estrategias que tienen la finalidad de solucionar o aminorar el problema. Entre estas medidas se encuentra el control del vector, desarrollo de agentes farmacológicos y vacunas de nueva generación, así como el uso de tratamientos alternativos que involucran extractos herbolarios con capacidad antiparasitaria. A pesar del poco éxito alcanzado, la OMS aun reporta 8 millones de personas infectadas en el mundo, 25 millones en riesgo de contraer la infección y un registro de 10,000 muertes al año. En este contexto, el problema se ha globalizado ya que recientemente se han registrado casos de Chagas en lugares no endémicos. Actualmente solo los fármacos Nifurtimox y Benznidazol han demostrado eficacia en el tratamiento, sin embargo, su empleo conlleva a efectos adversos cuya severidad es dosis dependiente y proporcional a la cronicidad de la enfermedad. El panorama epidemiológico de esta enfermedad podría ser un gran desafío, debido a la inexistencia de vacunas antiparasitarias efectivas, aunado a la resistencia farmacológica que últimamente se ha reportado en el parasito. Respecto a las estrategias vacunales, se han empleado antígenos de superficie del parásito como vacunas de ADN o proteínas recombinantes, las cuales han demostrado efectos inmunoestimulantes de las respuestas de tipo Th1 y Th2. En algunos casos, se ha controlado la carga parasitaria y el infiltrado inflamatorio, alcanzando mayor sobrevida en modelos de infección experimental. Sin embargo, estas medidas tienen limitantes terapéuticas, debido a que no se logra inmunidad estéril y/o las respuestas inmunitarias específicas son inadecuadas. Recientemente, llama la atención el uso de antioxidantes exógenos como medida terapéutica contra la enfermedad. En esta relación, las vitaminas E y C han demostrado efectos positivos en cuanto a la evolución de la cardiomiopatía chagasica crónica. Tales efectos cardioprotectores, se atribuyen a una disminución en los niveles de estrés y daño oxidativo, los cuales se asocian a la sobre-activación del sistema inmunitario contra la enfermedad de Chagas y/o a los efectos adversos propiciados por terapéutica farmacológica. En la presente investigación evaluamos el efecto de la ASTX in vitro, en parásitos cultivados axénicamente y en co-cultivo con células Vero, e in vivo, donde se evaluó la suplementación de la ASTX en ratones BALB/c infectados con T. cruzi previamente inmunizados con TcVac1M. Los resultados in vitro muestran que la astaxantina tiene efecto detrimental sobre los parásitos, pero no cuando se cultiva con monocapa de células Vero. In vivo, la ASTX no mostró valor terapéutico frente a la infección pues los ratones murieron antes del día 30 después de la infección y no contribuyo en el control de la parasitemia. Sin embargo, se mostró incremento en la infiltración linfo-plasmocítica de tipo focal en corazón, con reducción en el número de nidos de amastigotes, y en bazo los folículos linfoides fueron menos hiperplásicos en comparación con los grupos control. El uso de la vacuna TcVac1M y la suplementación con ASTX, no mostró control en la carga parasitaria y la vacuna por sí sola mostró 50 % de sobrevivencia comparado con el 25 % en los ratones suplementados con ASTX. También se observó una disminución en los niveles de estrés oxidativo y no hubo mejora en la producción de anticuerpos IgG. En tejido cardiaco la suplementación del antioxidante registró nidos de amastigotes con moderada infiltración linfo-plasmocítica, comparado con el grupo control vacunal el cual no registró nidos de amastigotes y el infiltrado fue ligero. De ahí que no se recomienda el uso de la ASTX durante la fase aguda de la infección por T. cruzi, ya sea solo o en combinación con fármacos terapéuticos. La vacuna TcVac1M por si sola induce una buena respuesta inmune contra la infección inducida por T. cruzi en ratones BALB/c. A pesar de lo reportado, son necesario nuevas estrategias vacunales y sería importante evaluar la ASTX en fase crónica de la enfermedad de Chagas y determinar si tiene potencial contra el desarrollo de la cardiomiopatía chagasica.Universidad Autónoma del Estado de México Proy No. 3326/201

Transforming a curriculum to put medical students on the frontline of public health

Medical Schoolhttp://deepblue.lib.umich.edu/bitstream/2027.42/170594/1/SarahContrerasOrtiz_1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/170594/2/SarahContrerasOrtiz_2.pd

TOURISM AND HISTORY WORLD HERITAGE – CASE STUDIES OF IBERO-AMERICAN SPACE

In 2010 traditional Mexican cuisine was declared an Intangible Cultural Heritage of Humanity by UNESCO (United Nations Educational, Scientific and Cultural Organization). This event was significant because it presented the opportunity to commercially capitalise on heritage cuisine (Laborde and Medina, 2015), and it served as a mechanism to promote Mexican cuisine on a global level; while at the same time represented the obligation to create policies for its preservation. Within these preservation efforts, tourism has been conceived as an effective tool for the valuation of this cuisine. Traditional Mexican cuisine is seen as a tourist attraction based on the resources and expertise of the countryǯs principal regional cuisines. (owever, this tourism does not always integrate all the different social actors directly involved with heritage cuisine. On the contrary, the development of an elitist gastronomic tourism may be observed, directed to global or Dzworld-classdz markets.The purpose of this essay is to analyse the relationship between heritage cuisine and tourism, along with its sociocultural implications within the framework of contemporary food consumption. Through an analysis of the language used in tourism advertising platforms and tourism policies, contrasted with ethnographic data, this essay examines the interaction between the actors, products and territories in Mexicoǯs eight gastronomic regions which have become attractions for tourists due to the inclusion of traditional Mexican cuisine in the UNESCO Intangible Cultural Heritage of Humanity List. We conclude that the tourist valuation of cuisine heritage promoted by Mexican institutions reflects a two-fold phenomenon, straddling the divide between economic valuation of agricultural food products and the cultural meaning of regional cuisines

A model for the development of programming courses to promote the participation of young women in STEM

There is a gender gap in science, technology, engineering, and mathematics (STEM), and this is a global problem that affects society. However, it is worth pointing out that the gap is not uniform in all STEM fields. Women’s underrepresentation is more marked in physics, engineering, and computer science fields. Nowadays, the labor market is becoming more competitive, technology-based and demands a diverse workforce. Therefore, it is important to continue promoting the participation of women in STEM, and the universities play a leading role in it. Previous research has shown that early learning experiences in STEM can show female students that they can succeed in this fields. This paper describes a model for developing programming courses for pre-university students to promote the participation of young women in STEM programs. The course was developed in one week, 25 students (16 girls and 9 boys) participated. The instructors of the course were four female professors. The programming language was Python, and the methodology used case-based learning. Both instructors and students gave positive comments on their experience in the course. The proposed model, including instruments, learning resources, and methodology, can be replicated and adapted to be used even in other learning field

New design parameters for biparabolic beach profiles (SW Cadiz, Spain)

165 profiles of seventy-one beaches along the Gulf of Cadiz (SW, Spain) were studied to improve the formulation of the beach profile in tidal seas. Maritime climate, degree of energy exposure and size of the sand grains were taken into account to study the two sections of the biparabolic profile. The objective of the study was the determination of more accurate formulations of the design parameters for the equilibrium profile that involves tidal seas. These formulations were modelled and validated based on existing profiles to quantify the error existing between the real profile and the modelling. This comparative analysis was extended by considering the formulations proposed by other authors. The best results were obtained with the proposal presented herein

A Design Parameter for Reef Beach Profiles—A Methodology Applied to Cadiz, Spain

The southwestern coast of Spain is in a tidal zone (mesotidal) which causes the equilibrium profile to be developed in two different sections: the breakage section and the swash section. These two sections give rise to the typical bi-parabolic profile existing in tidal seas. The existence of areas with reefs/rocks which interrupt the normal development of the typical bi-parabolic profile causes different types of beach profiles. The objective of this article is designing an easy methodology for determining new formulations for the design parameters of the equilibrium profile of beaches with reefs in tidal seas. These formulations are applied on 16 profiles to quantify the error between the real profile data and the modelling results. A comparative analysis is extended to the formulations proposed by other authors, from which it is found that better results are obtained with the new formulations

Improving the volatility of the optimal weights of the Markowitz model

The main practical problems that are faced by portfolio optimisation under the Markowitz model are (i) its lower out-of-sample performance than the naive 1=n rule, (ii) the resulting asset weights with extreme values, and (iii) the high sensitivity of those asset weights to small changes in the data. In this study, we aim to overcome these problems by using a computation method that shifts the smaller eigenvalues of the covariance matrix to the space that houses the eigenvalue spectrum of a random matrix. We evaluate this new method using a rolling sample approach. We obtain portfolios that show both more stable asset weights and better performance than the 1=n rule. We expect that this new computation method will be extended to several problems in portfolio management, thereby improving their consistency and performance

A multi-group SEIRA model for the spread of COVID-19 among heterogeneous populations

The outbreak and propagation of COVID-19 have posed a considerable challenge to modern society. In particular, the different restrictive actions taken by governments to prevent the spread of the virus have changed the way humans interact and conceive interaction. Due to geographical, behavioral, or economic factors, different sub-groups among a population are more (or less) likely to interact, and thus to spread/acquire the virus. In this work, we present a general multi-group SEIRA model for representing the spread of COVID-19 among a heterogeneous population and test it in a numerical case of study. By highlighting its applicability and the ease with which its general formulation can be adapted to particular studies, we expect our model to lead us to a better understanding of the evolution of this pandemic and to better public-health policies to control it