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.

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.

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.

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.

Accuracy of a method based on atomic absorption spectrometry to determine inorganic arsenic in food: Outcome of the collaborative trial IMEP-41.

A collaborative trial was conducted to determine the performance characteristics of an analytical method for the quantification of inorganic arsenic (iAs) in food. The method is based on (i) solubilisation of the protein matrix with concentrated hydrochloric acid to denature proteins and allow the release of all arsenic species into solution, and (ii) subsequent extraction of the inorganic arsenic present in the acid medium using chloroform followed by back-extraction to acidic medium. The final detection and quantification is done by flow injection hydride generation atomic absorption spectrometry (FI-HG-AAS). The seven test items used in this exercise were reference materials covering a broad range of matrices: mussels, cabbage, seaweed (hijiki), fish protein, rice, wheat, mushrooms, with concentrations ranging from 0.074 to 7.55mgkg(-1). The relative standard deviation for repeatability (RSDr) ranged from 4.1 to 10.3%, while the relative standard deviation for reproducibility (RSDR) ranged from 6.1 to 22.8%.

Arsenic levels in immigrant children from countries at risk of consuming arsenic polluted water compared to children from Barcelona.

Arsenic is a highly toxic element that pollutes groundwater, being a major environmental problem worldwide, especially in the Bengal Basin. About 40% of patients in our outpatient clinics come from those countries, and there is no published data about their arsenic exposure. This study compares arsenic exposure between immigrant and native children. A total of 114 children (57 natives, 57 immigrants), aged 2 months to 16 years, were recruited and sociodemographic and environmental exposure data were recorded. Total arsenic in urine, hair, and nails and arsenic-speciated compounds in urine were determined. We did not find significant differences in total and inorganic arsenic levels in urine and hair, but in organic arsenic monomethylarsenic acid (MMA) and dimethylarsinous acid (DMA) in urine and in total arsenic in nails. However, these values were not in the toxic range. There were significant differences between longer than 5 years exposure and less than 5 years exposure (consumption of water from tube wells), with respect to inorganic and organic MMA arsenic in urine and total arsenic in nails. There was partial correlation between the duration of exposure and inorganic arsenic levels in urine. Immigrant children have higher arsenic levels than native children, but they are not toxic. At present, there is no need for specific arsenic screening or follow-up in immigrant children recently arrived in Spain from exposure high-risk countries.

Toxic trace elements at gastrointestinal level.

Many trace elements are considered essential [iron (Fe), zinc (Zn), copper (Cu)], whereas others may be harmful [lead (Pb), cadmium (Cd), mercury (Hg), arsenic (As)], depending on their concentration and chemical form. In most cases, the diet is the main pathway by which they enter our organism. The presence of toxic trace elements in food has been known for a long time, and many of the food matrices that carry them have been identified. This has led to the appearance of legislation and recommendations concerning consumption. Given that the main route of exposure is oral, passage through the gastrointestinal tract plays a fundamental role in their entry into the organism, where they exert their toxic effect. Although the digestive system can be considered to be of crucial importance in their toxicity, in most cases we do not know the events that occur during the passage of these elements through the gastrointestinal tract and of ascertaining whether they may have some kind of toxic effect on it. The aim of this review is to summarize available information on this subject, concentrating on the toxic trace elements that are of greatest interest for organizations concerned with food safety and health: Pb, Cd, Hg and As.

Control de daño de extremidad pélvica en lesión compleja del pie: Reporte de un caso / Pelvic limb damage control following a complex foot injury: Case report

Las lesiones de la articulación tarsometatarsal (Lisfranc) son producidas en accidentes automovilísticos en más de 20% de los casos, siendo poco común este tipo de trauma y su reducción ha sido reportada en 50% de los casos de manera cerrada. Un paciente masculino de 18 años de edad electricista participa en trauma de alta energía, presentando fractura luxación de Lisfranc expuesta de pie izquierdo grado III B Gustilo y Anderson, siendo sometido a lavado y desbridamiento quirúrgicos, reducción abierta y fijación interna y cobertura cutánea inmediata. Con el tratamiento estricto y los cuidados de las lesiones ortopédicas severas, la proporción de las complicaciones secundarias pueden disminuir. El tratamiento de las lesiones severas de las extremidades incluyendo las óseas combinadas con la de los tejidos blandos (piel, tejido subcutáneo, fascias, uniones músculo-tendinosas, ligamentos, periostio y estructuras neurovasculares), deben seguir un protocolo multidisciplinario: desbridamiento extenso de tejido no viable, erradicación de infecciones y reconstrucción o cobertura de tejidos. Por lo que todo cirujano ortopedista debe tener conocimiento básico del mismo, teniendo vital importancia el manejo adecuado, la técnica precisa para cada caso y el momento preciso para su solución.

More than 20% of the tarsometatarsal joint injuries (Lisfranc injuries) occur during motor vehicle accidents. This kind of trauma is infrequent and in 50% of cases closed reduction is used. A 18 year-old male patient sustained a high-energy trauma resulting in a Gustilo and Anderson III B open Lisfranc fracture dislocation of the left foot. Surgical debridement, open reduction and internal fixation, and immediate skin coverage were performed. The secondary complication rate may decrease with stringent treatment adherence and proper care of severe orthopedic injuries. Treatment of the latter, including bone and soft tissue injuries (skin, subcutaneous tissue, fascias, musculotendinous junctions, ligaments, periosteum, and neurovascular structures) should follow a multidisciplinary protocol: extensive debridement of nonviable tissue, eradication of infections, and tissue reconstruction or coverage. Thus, any orthopedic surgeon should possess basic knowledge of this protocol. Proper management, using the right technique in each case, and the right timing of treatment are of the utmost importance.