Lactobacillus strains reduce the toxic effects of a subchronic exposure to arsenite through drinking water.

The aim of the present study was to determine the efficacy of LAB strains in reducing the intestinal toxicity of arsenite [As(III)] and its tissue accumulation. For this purpose, Balb/c mice were randomly separated in four groups. One group received no treatment (control), one group received only As(III) (30 mg/L) via drinking water and the remaining two groups received As(III) via water and a daily dose of two LAB strains (Lactobacillus intestinalis LE1 and Lacticaseibacillus paracasei BL23) by gavage during 2 months. The results show that both strains reduce the pro-inflammatory and pro-oxidant response observed at the colonic level, partially restore the expression of the intercellular junction proteins (CLDN3 and OCLN) responsible for the maintenance of epithelial integrity, and increase the synthesis of the major mucin of the colonic mucus layer (MUC2), compared to animals treated with As(III) alone. Microbial metabolism of short-chain fatty acids also undergoes a recovery and the levels of fatty acids in the lumen reach values similar to those of untreated animals. All these positive effects imply the restoration of mucosal permeability, and a reduction of the marker of endotoxemia LPS binding protein (LBP). Treatment with the bacteria also has a direct impact on intestinal absorption, reducing the accumulation of As in the internal organs. The data suggest that the protective effect may be due to a reduced internalization of As(III) in intestinal tissues and to a possible antioxidant and anti-inflammatory activity of the bacteria through activation of pathways such as Nrf2 and IL-10. In vitro tests show that the protection may be the result of the combined action of structural and metabolic components of the LAB strains.

Single closed-tube quantitative real-time PCR assay with dual-labelled probes for improved sex determination of equine embryos.

In addition to fulfilling many breeders' curiosity, equine embryonic sex determination can have a profound commercial impact. However, the application of currently described assays for equine embryonic sexing has rendered variable diagnosis and validation rates, with sensitivity being the main problem. In addition, while pregnancy results of in vivo-flushed equine embryos following a needle aspiration biopsy equal those of non-biopsied embryos, the effect on in vitro-produced embryos is unknown. Here, we aimed to develop a highly sensitive and specific assay for equine sex determination that can be directly performed on few embryonic cells, and to test the effect of a needle aspiration biopsy on the viability of the in vitro-produced embryo. To this end, a multiplex quantitative real-time PCR (qPCR) assay with dual-labelled probes was designed to allow the simultaneous generation of both male-specific and control fragments in a single closed-tube reaction, avoiding potential sample loss or contamination. To improve sensitivity, multicopy and polymeric genes were chosen to be specifically amplified, i.e., eight copies of Y-chromosomal ETSTY5 as male-specific and four autosomal UBC monomers as control fragment. Specificity was enhanced by the equine-specific character of ETSTY5 and by using dual-labelled probes. The assay was optimised with equine male and female genomic DNA and demonstrated a 100% accuracy and a >95% qPCR efficiency down to 10 pg of DNA. The assay was subsequently applied to determine the sex of 44 in vitro-produced embryos, collecting trophectoderm biopsies by means of a needle aspiration biopsy and herniating cells. Of all trophectoderm biopsies and herniating cell samples (n = 54), 87% could be diagnosed. Assay results were validated on a second sample obtained from the biopsied embryo (n = 18) or, by ultrasound-based sex determination of the foetus (n = 7) following the transfer of the biopsied embryo to a recipient mare, with about half of the embryos being fillies and colts. The needle aspiration biopsy procedure did not impair initial pregnancy rate or early pregnancy losses as compared to non-biopsied embryos. In conclusion, we report a safe, reliable, fast, and cost-effective assay for equine sex determination which was validated for the sex determination of in vitro-produced embryos based on few embryonic cells, and needle aspiration biopsy did not impair the embryo's viability. The assay and safe biopsy strategy hold potential for other applications.

Intestinal homeostasis disruption in mice chronically exposed to arsenite-contaminated drinking water.

Chronic exposure to inorganic arsenic [As(III) and As(V)] affects about 200 million people, and is linked to a greater incidence of certain types of cancer. Drinking water is the main route of exposure, so, in endemic areas, the intestinal mucosa is constantly exposed to the metalloid. However, studies on the intestinal toxicity of inorganic As are scarce. The objective of this study was to evaluate the toxicity of a chronic exposure to As(III) on the intestinal mucosa and its associated microbiota. For this purpose, BALB/c mice were exposed during 6 months through drinking water to As(III) (15 and 30 mg/L). Treatment with As(III) increased reactive oxygen species (43-64%) and lipid peroxidation (8-51%). A pro-inflammatory response was also observed, evidenced by an increase in fecal lactoferrin (23-29%) and mucosal neutrophil infiltration. As(III) also induced an increase in the colonic levels of pro-inflammatory cytokines (24-201%) and the activation of some pro-inflammatory signaling pathways. Reductions in the number of goblet cells and mucus production were also observed. Moreover, As(III) exposure resulted in changes in gut microbial alpha diversity but no differences in beta diversity. This suggested that the abundance of some taxa was significantly affected by As(III), although the composition of the population did not show significant alterations. Analysis of differential taxa agreed with this, 21 ASVs were affected in abundance or variability, especially ASVs from the family Muribaculaceae. Intestinal microbiota metabolism was also affected, as reductions in fecal concentration of short-chain fatty acids were observed. The effects observed on different components of the intestinal barrier may be responsible of the increased permeability in As(III) treated mice, evidenced by an increase in fecal albumin (48-66%). Moreover, serum levels of Lipopolysaccharide binding proteins and TNF-α were increased in animals treated with 30 mg/L of As(III), suggesting a low-level systemic inflammation.

Telerrehabilitación en personas con enfermedad cardiovascular durante el periodo de aislamiento preventivo obligatorio por COVID-19 en Colombia / Telerehabilitation in people with cardiovascular disease during the period of compulsory preventive isolation by COVID-19 in Colombia

Introducción: La enfermedad cardiovascular es una de las principales causas de morbimortalidad a nivel mundial. Como resultado de la pandemia de COVID-19, muchos programas de rehabilitación han pasado a modelos de entrega remota. La telerrehabilitación es una forma de realizar rehabilitación cardiaca mientras se reduce el riesgo de transmisión del COVID-19. Objetivo Describir los efectos de un programa de ejercicio terapéutico en personas con enfermedad cardiovascular que realizan telerrehabilitación, en el periodo de aislamiento preventivo obligatorio por COVID-19. Materiales y métodos Estudio cuasiexperimental, de 6 meses, en personas con enfermedad cardiovascular que ingresaron a un programa de ejercicio terapéutico asistido por tecnología virtual en una clínica de Cali (Colombia). Resultados De 31 personas, 21 eran hombres. La edad promedio fue de 60,48±11,21 años. Se encontraron diferencias significativas al inicio y al final del estudio en las variables de fracción de eyección del ventrículo izquierdo, frecuencia cardiaca, presión arterial, frecuencia respiratoria, índice de masa corporal, perímetro de abdomen, porcentaje de grasa, porcentaje de masa muscular, colesterol, estado de depresión, distancia recorrida, consumo de oxígeno e índice metabólico (MET), con p<0,05. Conclusión Un programa de ejercicio terapéutico en personas con enfermedad cardiovascular que realizan telerrehabilitación resulta eficaz, al alcanzar las metas de tratamiento (AU)

Introduction: Cardiovascular disease is one of the leading causes of morbidity and death globally. As a result of the COVID-19 pandemic, many rehabilitation programs have shifted to remote delivery models. Telerehabilitation is a way to perform cardiac rehabilitation while reducing the risk of COVID-19 transmission. Objective This study aimed to describe the effects of a physical exercise program in persons with cardiovascular disease who performed telerehabilitation in the period of mandatory preventive isolation due to the COVID-19 emergency. Materials and methods This was a quasiexperimental 6-month study of persons with cardiovascular disease who entered a virtual technology-assisted physical exercise program in a clinic in Cali, Colombia. Results Significant differences were found at the beginning and end of the study in the variables of left ventricular ejection fraction, heart rate, blood pressure, respiratory rate, body mass index, abdominal perimeter, percentage of fat, percentage of muscle mass, cholesterol, state of depression, distance traveled, oxygen consumption and metabolic equivalent (METs), showing p-value <0.05. Conclusions A physical exercise program in persons with cardiovascular disease performing telerrehabilitation proves effective in achieving treatment goals (AU)

Evaluación del perfil de seguridad del medicamento lopinavir/ritonavir (Lpv/r) en los pacientes sospechosos o confirmados por COVID-19 / Evaluation of the safety profile of the drug lopinavir/ritonavir (Lpv/r) in suspected or confirmed COVID-19 patients

Introducción: El nuevo SARS-CoV-2, es el agente causal de la enfermedad COVID-19. La Organización Mundial de la Salud (OMS) ha referenciado el uso del lopinavir/ritonavir (Lpv/r), es un inhibidor de la proteasa del virus de inmunodeficiencia humana adquirida (VIH-1). El estudio clínico de Cao et al., identificó que el uso de Lpv/r no se asociaron con un mayor número de eventos adversos en comparación con el tratamiento estándar.Materiales y métodos: Estudio retrospectivo de farmacovigilancia en una cohorte en pacientes sospechosos o confirmados de COVID-19 en un hospital de tercer Nivel de la Ciudad de México en el periodo 01 abril 2020 al 30 julio 2020. Resultados: El tratamiento de Lpv/r incluyó 140 pacientes, de los cuales 91 pacientes completaron el tratamiento, mientras que 50 pacientes no terminaron el esquema. Los principales motivos de la suspensión del esquema del medicamento fueron: alta por mejoría (11 casos), defunciones (10 casos) y por inicio de ruxolitinib (9 casos). Además, se identificaron 8 reacciones adversas al medicamento, de las cuales 5 son reacciones asociadas a los trastornos gastrointestinales (diarreas) y las otras 3 reacciones asociadas a trastornos hepatobiliares (hipertransaminasemia).Conclusión: El perfil de seguridad del medicamento Lpv/r demostró una coherencia con las observaciones de estudios previos en relación en los eventos adversos presentados de tipo gastrointestinales y hepáticos, estos últimos se encuentran relacionados a interacción fármaco-fármaco, por lo que sugerimos un seguimiento farmacoterapéutico para identificar las interacciones y las reacciones adversas durante el uso Lpv/r. (AU)

Abstract: The new SARS-CoV-2 is the causal agent for COVID-19. The World Health Organization (WHO) referenced the use of lopinavir/ritonavir (Lpv/r), which is a protease inhibitor of human inmunodeficiency virus (HIV-1). The Clinical trial by Cao et al. identified that the use of Lpv/r has not been associated with any increase of adverse drug reactions within compared to the standard of care.Materials and methods: Pharmacovigilance retrospective study of patients suspected or confirmed with COVID-19 in a 3rd level hospital in Mexico City from April, 01 2020 to July, 30 2020.Results: Lopinavir/ritonavir treatment was prescribed 140 patients from which 91 patients completed the treatment, while 50 patients did not completed the treatment. The cause suspensions were: patient discharge for improvement (11 cases), deaths (10 cases) and start of ruxolitinib (9 cases). In addition, were identify 8 adverse drug reaction from which 5 were associated to gastrointestinal disorders (diarrhea) and 3 hepatobiliary disorders (hypertransaminasemia).Conclusion: The safety profile of the Lpv/r demonstrated consistency with the observations of previous studies in relation to gastrointestinal and hepatic adverse events, which were related to drug-drug interaction, so we suggest a pharmacotherapeutic monitoring to identify them as well as adverse drug reactions due to Lpv/r. (AU)

Lipoteichoic acid depletion in Lactobacillus impacts cell morphology and stress response but does not abolish mercury surface binding.

Lipoteichoic acid (LTA) is a key component of the cell wall of most Gram-positive bacteria and plays many structural and functional roles. In probiotic lactobacilli, the function of LTA in mediating bacteria/host cross-talk has been evidenced and it has been postulated that, owing to its anionic nature, LTA may play a role in toxic metal sequestration by these bacteria. However, studies on this last aspect employing strains unable to synthesise LTA are lacking. We have inactivated the LTA polymerase encoding gene ltaS in two different Lactobacillus plantarum strains. Analysis of LTA contents in wild-type and ltaS mutant strains corroborated the role of this gene as a major contributor to LTA synthesis in L. plantarum. The mutant strains displayed strain-dependent anomalous cell morphologies that resulted in elongated or irregular cells with aberrant septum formation. They also exhibited higher sensitivity to several stresses (osmotic and heat) and to antimicrobials that target the cell wall. The toxicity of inorganic [(Hg(II)] and organic mercury (methyl-Hg) was also increased upon ltaS mutation in a strain-dependent manner. However, the mutant strains showed 0 to 50% decrease in their capacity of Hg binding compared to their corresponding parental strains. This result suggests a partial contribution of LTA to Hg binding onto the cell surface that was dependent on the strain and the Hg form.

Heterogeneous mass distribution of the rubble-pile asteroid (101955) Bennu.

The gravity field of a small body provides insight into its internal mass distribution. We used two approaches to measure the gravity field of the rubble-pile asteroid (101955) Bennu: (i) tracking and modeling the spacecraft in orbit about the asteroid and (ii) tracking and modeling pebble-sized particles naturally ejected from Bennu's surface into sustained orbits. These approaches yield statistically consistent results up to degree and order 3, with the particle-based field being statistically significant up to degree and order 9. Comparisons with a constant-density shape model show that Bennu has a heterogeneous mass distribution. These deviations can be modeled with lower densities at Bennu's equatorial bulge and center. The lower-density equator is consistent with recent migration and redistribution of material. The lower-density center is consistent with a past period of rapid rotation, either from a previous Yarkovsky-O'Keefe-Radzievskii-Paddack cycle or arising during Bennu's accretion following the disruption of its parent body.

Macromolecular crowding tunes 3D collagen architecture and cell morphogenesis.

Collagen I is the primary extracellular matrix component of most solid tumors and influences metastatic progression. Collagen matrix engineering techniques are useful for understanding how this complex biomaterial regulates cancer cell behavior and for improving in vitro cancer models. Here, we establish an approach to tune collagen fibril architecture using PEG as an inert molecular crowding agent during gelation and cell embedding. We find that crowding produces matrices with tighter fibril networks that are less susceptible to proteinase mediated degradation, but does not significantly alter matrix stiffness. The resulting matrices have the effect of preventing cell spreading, confining cells, and reducing cell contractility. Matrix degradability and fibril length are identified as strong predictors of cell confinement. Further, the degree of confinement predicts whether breast cancer cells will ultimately undergo individual or collective behaviors. Highly confined breast cancer cells undergo morphogenesis to form either invasive networks reminiscent of aggressive tumors or gland and lobule structures reminiscent of normal breast epithelia. This morphological transition is accompanied by expression of cell-cell adhesion genes, including PECAM1 and ICAM1. Our study suggests that cell confinement, mediated by matrix architecture, is a design feature that tunes the transcriptional and morphogenic state of breast cancer cells.

Effect of subchronic exposure to inorganic arsenic on the structure and function of the intestinal epithelium.

Inorganic arsenic (As), the most toxic form of As found in water and food, is considered a human carcinogen. Numerous studies show its systemic toxicity, describing pathologies associated with chronic exposure. The main pathway of exposure to inorganic As is oral, but many of the events that occur during its passage through the gastrointestinal tract are unknown. This study evaluates the effect of subchronic exposure to inorganic As [As(III): 0.025-0.1 mg/L; As(V): 0.25-1 mg/L, up to 21 days] on the intestinal epithelium, using Caco-2 cells as in vitro model. Inorganic As produces a pro-inflammatory response throughout the exposure time, with an increase in IL-8 release (up to 488%). It also causes changes in the program of cell proliferation and differentiation, which leads to impairment of the cell repair process. In addition, subchronic exposure affects the epithelial structure, causing loss of microvilli, fundamental structures in the processes of intestinal absorption and digestion. Moreover, the exposure affects the epithelial barrier function, evidenced by an increase of Lucifer Yellow transport (103-199%). Therefore, it can be concluded that subchronic exposure to inorganic As can alter intestinal homeostasis, affecting the mucosal layer, which performs the most important functions of the intestinal wall.

Leukocytoclastic vasculitis after influenza vaccination: an allergy assessment

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3D collagen architecture induces a conserved migratory and transcriptional response linked to vasculogenic mimicry.

The topographical organization of collagen within the tumor microenvironment has been implicated in modulating cancer cell migration and independently predicts progression to metastasis. Here, we show that collagen matrices with small pores and short fibers, but not Matrigel, trigger a conserved transcriptional response and subsequent motility switch in cancer cells resulting in the formation of multicellular network structures. The response is not mediated by hypoxia, matrix stiffness, or bulk matrix density, but rather by matrix architecture-induced ß1-integrin upregulation. The transcriptional module associated with network formation is enriched for migration and vasculogenesis-associated genes that predict survival in patient data across nine distinct tumor types. Evidence of this gene module at the protein level is found in patient tumor slices displaying a vasculogenic mimicry (VM) phenotype. Our findings link a collagen-induced migration program to VM and suggest that this process may be broadly relevant to metastatic progression in solid human cancers.

Inside game ball transitions according to players' specific positions in NBA basketball / Transiciones de balón del juego interior en función de la posición específica de los jugadores en baloncesto NBA / Transições da bola de jogo interior de acordo com o jogador posição específica em basquete NBA

The purposes of this study were to identify players' relationships and detecting ball transitions patterns according to their specific position when using inside pass, in the National Basketball Association (NBA) competition. In total, 808 inside passes (ball possession score differences below 10 points) from 25 matches (NBA Playofs, 2011) were analysed through systematic observation. A decision tree analysis (Chi-Squared Automatic Interaction Detection) was used to identify ball transitions patterns regarding specific players' position (roots) and passer-receiver interactions (predictors). We detected strong pass and reception sequences of movements according to players' specific position, especially when including interactions between perimeter and post players. Game conditions such as reception zone, pass distance, reception attitude, and defensive helps were also influenced by players' position. Current results point out the outside-inside coordination as an essential key to success in the NBA. It is recommended developing game dynamics focused in taking advantage of the high- and low-post positions, as well as performing supporting actions in the weak side to enhance inside pass options. These findings may have implications in basketball training and competition process, contributing in a better understanding of collective strategies which leads to an accurate designing of practices task focused on increasing inside game options and players' decision-making according to specific competition constraints (AU)

El objetivo de este estudio fue identificar las relaciones entre los jugadores y detectar los patrones de transición del balón en función de la posición específica de juego durante el uso del pase interior en la National Basketball Association (NBA). Se analizaron un total de 808 pases interiores (diferencia en el marcador por debajo de 10 puntos) correspondientes a 25 partidos (Playofs de la NBA, 2011) a través de observación sistemática. Se utilizó un análisis de árbol decisional (Chi-Squared Automatic Interaction Detection) para identificar los patrones de transición de la pelota en función de la posición específica de los jugadores (raíces) y las interacciones pasador-receptor (predictores). Se detectaron secuencias de movimientos bien definidas entre pasador y receptor de acuerdo a sus posiciones de juego, especialmente si se incluían relaciones entre jugadores del perímetro y del poste. Las condiciones del juego como la zona de recepción, distancia de pase, actitud del receptor, y las ayudas defensivas estuvieron influenciadas por las posiciones de los jugadores. Estos resultados señalan la coordinación del juego exterior-interior como un aspecto esencial para el éxito en la NBA. Se recomienda desarrollar un juego dinámico centrado en aprovechar la ventaja de las posiciones de poste alto y poste bajo, así como realizar acciones de apoyo en el lado débil para aumentar las opciones de pase interior. Las conclusiones del presente estudio podrían por tanto tener implicaciones en el proceso de entrenamiento y competición de baloncesto, contribuyendo al entendimiento de las estrategias colectivas de los jugadores y con ello al diseño de tareas de práctica centradas en el aumento de las opciones de juego interior y a la mejora de la toma de decisiones de los jugadores que respondan a las demandas específicas de la competición (AU)

O objetivo deste estudo foi identificar as relações entre jogadores e detectar padrões de transição da bola de acordo com o jogador posição específica em uso de passe interior em National Basketball Association (NBA). Foram analisados um total de 808 passes interiores (diferença na pontuação abaixo de 10 pontos) por 25 jogos (NBA Playofs, 2011) através da observação sistemática. A análise da árvore de decisão (Chi-Squared Automatic Interaction Detection) foi utilizado para identificar padrões de transição da bola dependendo do jogador posição específica (raízes) e passador-receptor interações (preditoras). Sequências de movimentos bem definidos entre passer e receptor de acordo com suas posições de jogo, especialmente se as relações entre os jogadores de perímetro e poste incluídos foram detectados. As condições de jogo como a área de recepção, distância para passar, atitude do receptor, e as ajudas defensivas foram influenciados pelas posições dos jogadores. Estes resultados indicam a coordenação do jogo de fora para dentro, como um aspecto essencial para o sucesso na NBA. Recomenda-se a desenvolver um jogo dinâmico centrado aproveitar as posições do pólo de poste alto e baixo, bem como as ações de apoio ao lado fraco para aumentar dentro opções de passagem. Os resultados deste estudo poderiam, portanto, ter implicações para o processo de treinamento e competição de basquete, contribuindo para a compreensão das estratégias coletivas dos jogadores e, assim, a prática do design tarefa focada em opções aumentando dentro do jogo e melhorar a tomada de decisão dos jogadores que atendam às demandas específicas da competição (AU)

Gestión de equipos médicos: implementación y validación de una herramienta de auditoría / Health technology management: implementation and validation of an audit tool

Resumen: La auditoría en salud es un proceso dinámico y en continuo avance que permite evaluar y controlar estándares de calidad en las instituciones de salud, sin embargo, la falta de estandarización y confiabilidad de resultados sigue siendo un reto por superar. Este trabajo presenta la validación de un prototipo de herramienta de auditoría para la gestión de equipos médicos la cual se realizó en dos fases: primero durante la implementación en tres hospitales del Área Metropolitana del Valle de Aburra, en Antioquia, Colombia, y posteriormente a través del análisis estadístico del juicio de expertos. Los hallazgos permitieron generar acciones de mejora con base en los informes de fortalezas y debilidades puntuales. Por su parte las mediciones de coeficientes de confiabilidad (Cronbach α= 0.90) y correlación de expertos (Spearman =0.88) indicaron resultados favorables para la herramienta. Además, la medición de promedios, desviaciones estándar y coeficientes de variación para cada ítem de la validación, expuso las mejoras que requiere la herramienta para una versión futura. La propuesta de la herramienta se limita a la regulación en salud Colombiana sin embargo no se aleja del marco normativo internacional, por lo que se considera es un paso relevante importante para convertir las auditorias en salud en procesos estandarizados. Puede concluirse que integrar al ingeniero biomédico en actividades de auditoría de calidad en salud con herramientas confiables ofrece un beneficio importante para la toma de decisiones oportuna en la gestión de los equipos médicos.

Abstract: Audit in health is a dynamic process and continuous advancement that permits to asses monitor and improve quality standards in healthcare institutions; however, the lack of standardization and reliability of results remains a challenge to be overcome. This study presents the validation of a prototype of an audit tool to the management of medical equipment which took place in two phases: first during the implementation in three hospitals in the metropolitan area of Antioquia, Colombia, and subsequently through the statistical analysis of the trial of twelve selected experts. As results audit reports were generated with strengths and weaknesses points, which enabled us to build improvement measures suitable for hospitals. Measurements of coefficients of reliability (Cronbach α= 0.90) and correlation of experts (Spearman =0.88) indicated favorable results for the tool. In addition, the measurement of mean, standard deviations and coefficients of variation for each item of the validation set out the improvements required by the tool for a future version. This tool is limited to the health regulation in Colombia; nevertheless, the tool is an important step to find and transform the health audits in standardized process that can have an objective assessment. To can be concluded to integrate the biomedical engineer in the activities of audit quality on health with reliable tools offers an important benefit for accurate decision making and timely management of the medical equipment.

In Vitro Reduction of Arsenic Bioavailability Using Dietary Strategies.

The main route of human exposure to inorganic arsenic (As) is through the consumption of food and water. Continued exposure to inorganic As [As(III) and As(V)] may cause a variety of diseases, including various types of cancer. The removal of As from these sources is complex, especially for food. One way to decrease As exposure could be by reducing intestinal absorption of it. The aim of this study is to seek dietary strategies (pure compounds, extracts, or supplements) that are capable of reducing the amount of As that is absorbed and reaches systemic circulation. Standard solutions of As(III) and As(V) and bioaccessible fractions of food samples with or without the dietary strategies to be tested were added to colon-derived human cells (NCM460 and HT-29MTX) to determine the apparent permeability (Papp) of As. Results show that transport across the intestinal monolayers is substantial, and the passage of As(III) (Papp = 4.2 × 10-5 cm/s) is greater than that of As(V) (Papp = 2.4 × 10-5 cm/s). Some of the treatments used (iron species, cysteine, grape extract) significantly reduce the transport of both inorganic As standards across the intestinal monolayer, thus decreasing absorption of them. In food samples, the effect of the dietary compounds on inorganic As bioavailability was also observed, especially in the cases of curcumin and cysteine. Compounds that proved effective in these in vitro assays could be the basis for intervention strategies aimed at reducing As toxicity in chronically exposed populations or regular consumers of food products with high As contents.

The use of lactic acid bacteria to reduce mercury bioaccessibility.

Mercury in food is present in either inorganic [Hg(II)] or methylmercury (CH3Hg) form. Intestinal absorption of mercury is influenced by interactions with other food components. The use of dietary components to reduce mercury bioavailability has been previously proposed. The aim of this work is to explore the use of lactic acid bacteria to reduce the amount of mercury solubilized after gastrointestinal digestion and available for absorption (bioaccessibility). Ten strains were tested by addition to aqueous solutions containing Hg(II) or CH3Hg, or to food samples, and submission of the mixtures to gastrointestinal digestion. All of the strains assayed reduce the soluble fraction from standards of mercury species under gastrointestinal digestion conditions (72-98%). However their effectiveness is lower in food, and reductions in bioaccessibility are only observed with mushrooms (⩽68%). It is hypothesized that bioaccessible mercury in seafood forms part of complexes that do not interact with lactic acid bacteria.