Desarrollo, análisis y optimización de modelos celulares hepáticos para estudios de fármaco-toxicología y terapia celular

Given the importance of the liver in the metabolism and maintenance of the homeostasis of the organism, many studies have been conducted in the area of toxicology and, more recently, in hepatic cellular therapy. However, the main drawback is the limited availability of viable and functional hepatocytes due to the scarcity of liver tissue. The purpose of this work was based on the development and characterization of hepatic cellular models to become an alternative to hepatocytes in toxicology studies and cellular therapy. To this end, three main objectives have been investigated: 1) to adopt a procedure of hepatocyte isolation from discarded organs for transplantation which determines the optimal conditions for the isolation and culture of hepatocytes, 2) to characterize the cells from the hepatoblastome HepG2, and 3) to develop a hepatogenic differentiation protocol to induce the hepatic differentiation in adipose-derived stem cells (ADSC). In particular, the hepatogenic differentiation of stem cells opens a wide range of possibilities to facilitate the establishment of an adult differentiated cellular model useful for pharmaco-toxicological studies and for hepatic cellular therapy. The use of adult stem cells may allow the establishment of an adult cellular model with properties that others cellular models, like HepG2, do not show. However, it is necessary to optimise the isolation and cryopreservation procedures, as well as the differentiation protocols from adult stem cells and try to acquire a wide knowledge of the cellular and molecular mechanisms that control the transdifferentiation to hepatocytes.Key Words: cellular transplant, esteatosis, human hepatocytes, hepatoblastomes, stem cells.El hígado juega un papel fundamental en el metabolismo de medicamentos y en el mantenimiento de la homeostasis del organismo y, por tanto los modelos celulares hepáticos desempeñan un papel clave para estudios fármaco-toxicológicos y más recientemente en el campo de la terapia celular. Sin embargo, la limitada disponibilidad de hepatocitos viables y funcionales debido a la falta de tejido hepático es la principal limitación para utilizar estos recursos celulares. El objetivo del presente trabajo se ha basado en el desarrollo y caracterización de modelos celulares hepáticos que puedan constituir una alternativa a los hepatocitos para este tipo de aplicaciones. Para ello se han abordado tres estrategias diferentes: 1) optimización del proceso de obtención de hepatocitos a partir de hígados enteros descartados para transplante, determinando las condiciones adecuadas para el aislamiento y cultivo de hepatocitos; 2) caracterización funcional de las células del hepatoblastoma HepG2 y 3) desarrollo de un protocolo para inducir la diferenciación hepatogénica de células madre mesenquimales adultas derivadas de tejido adiposo (ADSC). Para conseguir un buen aprovechamiento de hígados descartados para transplante resulta necesario optimizar los protocolos de aislamiento y criopreservación de hepatocitos. El estudio con células madre adultas se presenta como una alternativa muy válida para la obtención de hepatocitos-like viables y funcionalmente activos útiles a corto plazo en estudios de fármaco-toxicología y en un futuro para terapia celular hepática. El uso de células madre abre un gran abanico de posibilidades facilitando el establecimiento de un modelo celular diferenciado adulto con características que otros modelos celulares, como son el hepatoma humano HepG2, no presentan. No obstante, es necesario adquirir un mayor conocimiento de los mecanismos celulares y moleculares que controlan la transdiferenciación a hepatocitos.Palabras clave: trasplante celular, esteatosis, hepatocitos humanos, hepatoblastomas, células madre

Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight NCD Risk Factor Collaboration (NCD-RisC)

From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions

Worldwide trends in hypertension prevalence and progress in treatment and control from 1990 to 2019: a pooled analysis of 1201 population-representative studies with 104 million participants

Background Hypertension can be detected at the primary health-care level and low-cost treatments can effectively control hypertension. We aimed to measure the prevalence of hypertension and progress in its detection, treatment, and control from 1990 to 2019 for 200 countries and territories. Methods We used data from 1990 to 2019 on people aged 30–79 years from population-representative studies with measurement of blood pressure and data on blood pressure treatment. We defined hypertension as having systolic blood pressure 140 mm Hg or greater, diastolic blood pressure 90 mm Hg or greater, or taking medication for hypertension. We applied a Bayesian hierarchical model to estimate the prevalence of hypertension and the proportion of people with hypertension who had a previous diagnosis (detection), who were taking medication for hypertension (treatment), and whose hypertension was controlled to below 140/90 mm Hg (control). The model allowed for trends over time to be non-linear and to vary by age. Findings The number of people aged 30–79 years with hypertension doubled from 1990 to 2019, from 331 (95% credible interval 306–359) million women and 317 (292–344) million men in 1990 to 626 (584–668) million women and 652 (604–698) million men in 2019, despite stable global age-standardised prevalence. In 2019, age-standardised hypertension prevalence was lowest in Canada and Peru for both men and women; in Taiwan, South Korea, Japan, and some countries in western Europe including Switzerland, Spain, and the UK for women; and in several low-income and middle-income countries such as Eritrea, Bangladesh, Ethiopia, and Solomon Islands for men. Hypertension prevalence surpassed 50% for women in two countries and men in nine countries, in central and eastern Europe, central Asia, Oceania, and Latin America. Globally, 59% (55–62) of women and 49% (46–52) of men with hypertension reported a previous diagnosis of hypertension in 2019, and 47% (43–51) of women and 38% (35–41) of men were treated. Control rates among people with hypertension in 2019 were 23% (20–27) for women and 18% (16–21) for men. In 2019, treatment and control rates were highest in South Korea, Canada, and Iceland (treatment >70%; control >50%), followed by the USA, Costa Rica, Germany, Portugal, and Taiwan. Treatment rates were less than 25% for women and less than 20% for men in Nepal, Indonesia, and some countries in sub-Saharan Africa and Oceania. Control rates were below 10% for women and men in these countries and for men in some countries in north Africa, central and south Asia, and eastern Europe. Treatment and control rates have improved in most countries since 1990, but we found little change in most countries in sub-Saharan Africa and Oceania. Improvements were largest in high-income countries, central Europe, and some upper-middle-income and recently high-income countries including Costa Rica, Taiwan, Kazakhstan, South Africa, Brazil, Chile, Turkey, and Iran. Interpretation Improvements in the detection, treatment, and control of hypertension have varied substantially across countries, with some middle-income countries now outperforming most high-income nations. The dual approach of reducing hypertension prevalence through primary prevention and enhancing its treatment and control is achievable not only in high-income countries but also in low-income and middle-income settings

Efecto de la radiación gamma sobre PEUAPM/MWNTS nanocomposites

Trabajo presentado al XI Congreso Nacional de Materiales celebrado en Zaragoza del 23 al 25 de junio de 2010.El presente trabajo muestra una alternativa a los polietilenos altamente reticulados utilizados como material protésico. Se termoconformaron materiales compuestos de polietileno de ultra alto peso molecular (PEUAPM) con diferentes concentraciones de nanotubos de carbono multicapa (1%%, 3% y 5%peso MWNT). Posteriormente, los composites se irradiaron con radiación gamma a una dosis de 90 kGy. Las propiedades térmicas y microestructurales se determinaron con DSC, SEM y TEM. Los resultados de DSC mostraron que la incorporación de MWNTs reduce la cristalinidad del polímero. Los ensayos de tracción revelaron un aumento significativo en el módulo de Young, así como una compensación de la pérdida de tenacidad que la radiación produce sobre el polietileno, mostrando un efecto sinérgico entre la radiación y los nanotubos de carbono. Este efecto confirma la tendencia a atrapar radicales de los nanotubos de carbono.El presente trabajo ha sido financiado por el proyecto MAT2006-12603-C02-01 del Ministerio de Ciencia e Innovación.Peer reviewe

Association Between Blood Pressure and Mortality in a Spanish Cohort of Persons Aged 65 Years or Over: A Dynamic Model

Introduction and objectives: Few studies have used time-dependent correction to analyze the relationship between blood pressure and all-cause mortality, and to our knowledge none has been performed in older people from the Mediterranean area. This study aimed to estimate the relationship between baseline blood pressure and blood pressure as a time-dependent covariate with the risk of all-cause mortality in a population cohort of persons aged 65 or older in Spain. Methods: Data were taken from the population-based study ''Aging in Legané s'' with 17 years of followup, launched in 1993 in a random sample (n=1560) of persons aged !65 years. Mortality was assessed in 2010. Cox proportional hazards models were fitted to examine the effects on mortality of blood pressure at baseline and of blood pressure as a time-dependent covariate. Results: The lowest mortality was observed at baseline systolic blood pressure of 136 mmHg and timedependent covariate value of 147 mmHg. The highest risk of mortality for time-dependent covariates occurred with systolic blood pressure<115 mmHg and >93 mmHg and diastolic blood pressure<80 mmHg. Diastolic blood pressure over 85 mmHg did not increase the risk of death. Conclusions: Based on the dynamic association between blood pressure and mortality, a U-shaped relationship was found for systolic blood pressure and a negative relationship for diastolic blood pressure and all-cause mortality. The lowest mortality corresponded to a systolic blood pressure level slightly over the diagnostic hypertension value and suggests that a value of 140 mmHg is not adequate as a diagnostic and therapeutic threshold in an elderly population. ß 2012 Sociedad Españ ola de Cardiología. Published by Elsevier Españ a, S.L. All rights reserved. Asociació n entre presió n arterial y mortalidad en una cohorte de individuos de edad igual o superior a 65 añ os de Españ a: un modelo diná mico Palabras clave: Hipertensió n Arterial sisté mica Mayores de 65 añ os Mortalidad R E S U M E N Introducción y objetivos: Son pocos los estudios que han utilizado una correcció n dependiente del tiempo para analizar la relació n entre presió n arterial y mortalidad por cualquier causa, y hasta donde sabemos no se ha realizado ninguno en ancianos del á rea mediterrá nea. El objetivo de este estudio es estimar la relació n que la presió n arterial basal y la presió n arterial como variable dependiente del tiempo tienen con el riesgo de mortalidad por cualquier causa en una cohorte poblacional en Españ a de personas de 65 o má s añ os. Me´todos: Los datos se obtuvieron del estudio de base poblacional «Envejecer en Legané s», con un seguimiento de 17 añ os, que se puso en marcha en 1993 en una muestra aleatoria (n = 1.560) de personas de 65 o má s añ os. Se evaluó la mortalidad en 2010. Se ajustaron modelos de riesgos proporcionales de Cox para analizar los efectos de la presió n arterial basal y la presió n arterial como covariable dependiente del tiempo en la mortalidad. Resultados: El valor mínimo de mortalidad se observó con una presió n arterial sistó lica basal de 136 mmHg y un valor de presió n arterial sistó lica como covariable dependiente del tiempo de 147 mmHg. El riesgo de mortalidad má s alto para la presió n arterial sistó lica como covariable dependiente del tiempo se produjo con valores de presió n arterial sistó lica < 115 y > 193 mmHg y presió n arterial diastó lica < 80 mmHg. Valores de presió n arterial diastó lica > 85 mmHg no aumentaron el riesgo de muerte. Conclusiones: Teniendo en cuenta la relació n diná mica entre la presió n arterial y la mortalidad, nuestros datos muestran una relació n en forma de U para la presió n arterial sistó lica y una relació n negativa par

Photolytic Degradation of Benorylate Effects of the Photoproducts on Cultured Hepatocytes

[EN] The photodegradation of benorylate [4¿-(acetamido)phenyl-2-acetoxybenzoate], a drug frequently used in rheumatoid arthritis therapy, has been examined under different sets of experimental conditions. Several photoproducts have been isolated and identified on the basis of their IR, NMR, and MS spectra. The most significant photochemical process is the photo-Fries rearrangement of benorylate, leading to 5-acetamido-2¿-acetoxy-2-hydroxybenzophenone (1). This compound undergoes a rapid transacylation to the isomeric 5¿-acetamido-2¿-acetoxy-2-hydroxybenzophenone (2). A primary culture of rat hepatocytes has been used to evaluate the possible toxicity of these two benzophenones, keeping in mind the following criteria: leakage of cytosolic enzymes, attachment index to culture plates, gluconeogenesis from lactate and fructose, glycogen balance, and albumin synthesis. At the concentrations assayed, neither of the two major photoproducts of benorylate (benzophenones 1 and 2) had significant toxic effects on liver cells in culture.Financial support Comisión Asesora de Investigación Científica y Técnica (grant no.1325) is gratefully acknowledged.Castell, J.; Gómez-Lechon, M.; Mirabet, V.; Miranda Alonso, MÁ.; Morera Bertomeu, IM. (1987). Photolytic Degradation of Benorylate Effects of the Photoproducts on Cultured Hepatocytes. Journal of Pharmaceutical Sciences. 76(5):374-378. https://doi.org/10.1002/jps.2600760507S37437876

Effects of gamma-irradiation on UHMWPE/MWNT nanocomposites

Ultra high molecular weight polyethylene (UHMWPE) is a polymer that is widely used in industrial and orthopaedic applications. In this work, pristine multiwalled carbon nanotubes (MWCNTs) were incorporated into UHMWPE in different concentrations (1, 3 and 5. wt.%) using a ball milling process. UHMWPE/MWCNT nanocomposites were gamma irradiated at 90. kGy to improve the interaction between MWCNTs and the polymer matrix. Structural, thermal and mechanical characterizations were conducted by means of transmission electron microscopy (TEM), Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA) and uniaxial tensile techniques. Gamma irradiation produced an increase in the melting temperature, crystallinity and temperature of maximum decomposition rate. The irradiation produced a 38% decrease in the toughness of neat UHMWPE. The incorporation of MWCNTs did not significantly affect the melting point of the neat UHMWPE but decreased the degree of crystallinity of the raw UHMWPE, which was related to a reduction in the UHMWPE lamellar density. An increase in thermal stability was also observed for the nanocomposites compared to neat UHMWPE. The tensile tests showed a 38% increase in the Young's modulus in the reinforced nanocomposites and a small decrease in toughness (5%). Gamma irradiation of the nanocomposites increased crystallinity, which was related to an increased lamellar thickness, and also improved their thermal stability. The Young's modulus increased by up to 71% for irradiated nanocomposites and their toughness showed no significant changes in comparison with the non-irradiated nanocomposites. The incorporation of MWCNTs reduced the negative effects of irradiation and compensated for the reduction in toughness. This fact might be attributed to the radical scavenger behaviour of the MWNT as was proved by Electron Spin Resonance (ESR) detection of the radiation-induced radicals. © 2010 Elsevier Ltd.Research funded by the Comisión Interministerial de Ciencia y Tecnología (CICYT), Spain. Project: MAT 2010-16175.Peer Reviewe

Toxic trace elements in maternal and cord blood and social determinants in a Bolivian mining city

This study assessed lead, arsenic, and antimony in maternal and cord blood, and associations between maternal concentrations and social determinants in the Bolivian mining city of Oruro using the baseline assessment of the ToxBol/Mine-Nino birth cohort. We recruited 467 pregnant women, collecting venous blood and sociodemographic information as well as placental cord blood at birth. Metallic/semimetallic trace elements were measured using inductively coupled plasma mass spectrometry. Lead medians in maternal and cord blood were significantly correlated (Spearman coefficient=0.59; p<0.001; 19.35 and 13.50 μg/L, respectively). Arsenic concentrations were above detection limit (3.30 μg/L) in 17.9% of maternal and 34.6% of cord blood samples. They were not associated (Fischer's p=0.72). Antimony medians in maternal and cord blood were weakly correlated (Spearman coefficient=0.15; p<0.03; 9.00 and 8.62 μg/L, respectively). Higher concentrations of toxic elements in maternal blood were associated with maternal smoking, low educational level, and partner involved in mining