Noninvasive assessment of inspiratory muscle neuromechanical coupling during inspiratory threshold loading

Diaphragm neuromechanical coupling (NMC), which reflects the efficiency of conversion of neural activation to transdiaphragmatic pressure (Pdi), is increasingly recognized to be a useful clinical index of diaphragm function and respiratory mechanics in neuromuscular weakness and cardiorespiratory disease. However, the current gold standard assessment of diaphragm NMC requires invasive measurements of Pdi and crural diaphragm electromyography (oesEMGdi), which complicates the measurement of diaphragm NMC in clinical practice. This is the first study to compare invasive measurements of diaphragm NMC (iNMC) using the relationship between Pdi and oesEMGdi, with noninvasive assessment of NMC (nNMC) using surface mechanomyography (sMMGlic) and electromyography (sEMGlic) of lower chest wall inspiratory muscles. Both invasive and noninvasive measurements were recorded in twelve healthy adult subjects during an inspiratory threshold loading protocol. A linear relationship between noninvasive sMMGlic and sEMGlic measurements was found, resulting in little change in nNMC with increasing inspiratory load. By contrast, a curvilinear relationship between invasive Pdi and oesEMGdi measurements was observed, such that there was a progressive increase in iNMC with increasing inspiratory threshold load. Progressive recruitment of lower ribcage muscles, serving to enhance the mechanical advantage of the diaphragm, may explain the more linear relationship between sMMGlic and sEMGlic (both representing lower intercostal plus costal diaphragm activity) than between Pdi and crural oesEMGdi. Noninvasive indices of NMC derived from sEMGlic and sMMGlic may prove to be useful indices of lower chest wall inspiratory muscle NMC, particularly in settings that do not have access to invasive measures of diaphragm function.Peer ReviewedPostprint (published version

Study of Fucoidans as Natural Biomolecules for Therapeutical Applications in Osteoarthritis

[Abstract] Osteoarthritis (OA) is the most prevalent articular chronic disease. Although, to date there is no cure for OA. Fucoidans, one of the main therapeutic components of brown algae, have emerged as promising molecules in OA treatment. However, the variability between fucoidans makes difficult the pursuit of the most suitable candidate to target specific pathological processes. By an in vitro experimental approach in chondrocytes and fibroblast-like synoviocytes, we observed that chemical composition of fucoidan, and specifically the phlorotannin content and the ratio sulfate:fucose, seems critically relevant for its biological activity. Nonetheless, other factors like concentration and molecular weight of the fucoidan may influence on its beneficial effects. Additionally, a cell-type dependent response was also detected. Thus, our results shed light on the potential use of fucoidans as natural molecules in the treatment of key pathological processes in the joint that favor the development of rheumatic disorders as OA.Xunta de Galicia; ED431G2019/0

Using Chemical Modeling to Asses Water Quality in the Raigón Aquifer System in Southern Uruguay

The Raigón aquifer is an important groundwater system in southern Uruguay. The increasing use of groundwater resources in the last decades has provoked changes in the concentration of many elements which are strongly related to anthropogenic pollution sources. Concentration levels are useful to detect changes in reservoir status but it is also necessary to analyze their chemical significance in order to make an accurate assessment of the sources of contamination and the causes of changes. In this work we use the available thermodynamic data to calculate chemical speciation on these groundwater samples. Trace elements present as anions, in particular Se and Mo, are especially focused to show the chemical modeling possibilities. Both elements form anionic species, predominantly MoO42- and SeO42-. Results show that these anions interact in solution and are greatly influenced by the concentration of the abundant calcium ion. Localized changes in pH can strongly affect the situation. The same is observed with the pE parameter, but only in the case of Se. Chemical speciation of trace elements is in general highly dependent on pH, pE and concentration of major elements. In consequence, for a fixed analytical total concentration, these parameters can markedly change the situation, affecting the mobility, the bioavailability and environmental fate of these elements. The strategy employed in this work can also be extended to the study of many other environmental water scenarios.The authors are grateful to CSIC (Programa de Apoyo a Grupos) and ANII (Project FCE_2011_6491), Uruguayan organizations, for financial support.Peer Reviewe

In vitro study of the therapeutic potential of brown crude fucoidans in osteoarthritis treatment

[Abstract] Osteoarthritis, one of the most common joint degenerative pathologies, still has no cure, and current treatments, such as nonsteroidal anti-inflammatory drugs, can cause serious adverse effects when taken for a long time. Brown seaweed crude fucoidans are used for the clinical treatment of several pathologies. In this study, the therapeutical potential of these biocompounds was analyzed in primary chondrocytes and the 260TT human chondrocyte cell line. Crude fucoidan from Undaria pinnatifida (Up) and Sargassum muticum (Sm) was obtained by different extraction techniques (microwave-assisted extraction, pressurized hot-water extraction, ultrasound-assisted extraction) and chemically and structurally characterized by Fourier transform infrared spectroscopy, high-performance size-exclusion chromatography, proton nuclear magnetic resonance, and scanning electron microscopy. Once cell viability was confirmed in chondrocytes treated with crude fucoidans, we evaluated their anti-inflammatory effects, observing a significant reduction in IL-6 production stimulated by IL-1β. Findings were confirmed by analysis of IL-6 and IL-8 gene expression, although only fucoidans from Up achieved a statistically significant reduction. Besides this, the antioxidant capacity of crude fucoidans was observed through the upregulation of Nrf-2 levels and the expression of its transcriptional target genes HO-1 and SOD-2, with compounds from Up again showing a more consistent effect. However, no evidence was found that crude fucoidans modulate senescence, as they failed to reduced β-galactosidase activity, cell proliferation, or IL-6 production in chondrocytes stimulated with etoposide. Thus, the findings of this research seem to indicate that the tested crude fucoidans are capable of partially alleviating OA-associated inflammation and oxidative stress, but fail to attenuate chondrocyte senescence

Spreadsheet for the simulation of artificial neural networks (ANNs)

La utilización de Redes de Neuronas Artificiales (RNA) en problemas de predicción de series de tiempo, clasificación y reconocimiento de patrones ha aumentado considerablemente en los últimos años. Programas informáticos de matemáticas de propósito general tales como MATLAB, MATHCAD y aplicaciones estadísticas como SPSS y S-PLUS incorporan herramientas que permiten implementar RNAs. A esta oferta de software hay que añadir programas específicos como NeuralWare, EasyNN o Neuron. Desde un punto de vista educativo, el acceso de los estudiantes a estos programas puede ser difícil dado que no están pensadas como herramientas didácticas. Por otro lado, las hojas de cálculo como Excel y Gnumeric incorporan utilidades que permiten implementar RNAs y son de fácil acceso para los estudiantes. El objetivo de este trabajo es proporcionar un pequeño tutorial sobre la utilización de Excel para implementar una RNA que nos permita ajustar los valores de una serie de tiempo correspondiente a actividad cerebral alfa y que permita al alumno entender el funcionamiento de estos dispositivos de cálculo.In recent years, the use of Artificial Neural Networks or ANNs has increased considerably to solve prediction problems in time series, classification and recognition of patterns. General-purpose mathematical programs such as MATLAB, MATHCAD and mathematical and statistical programs such as SPSS and S-PLUS incorporate tools that allow the implementation of ANNs. In addition to these, specific programs such as NeuralWare, EasyNN, or Neuron, complete the software offer using ANNs. From an educational point of view, an aspect that concerns the authors of this work, student access to these programs can be expensive or, in sorne case, unadvisable given the few possibilities they provide as didactic instruments. These programs are usually easy to use but do not facilitate the understanding of the technique used. On the other hand, spreadsheets like Excel or Gnumeric incorporate tools that allow all of the necessary calculations to implement an ANN. These programs are user-friendly to the point that they are used by university laboratories, as well as psychology, economic science, and engineering students, to mention a few. This paper provides a small tutorial on the use of a spreadsheet, specifically Excel, to implement an ANN to adjust the values of a time series corresponding to cerebral alpha activity

Noninvasive assessment of neuromechanical coupling and mechanical efficiency of parasternal intercostal muscle during inspiratory threshold loading

This study aims to investigate noninvasive indices of neuromechanical coupling (NMC) and mechanical efficiency (MEff) of parasternal intercostal muscles. Gold standard assessment of diaphragm NMC requires using invasive techniques, limiting the utility of this procedure. Noninvasive NMC indices of parasternal intercostal muscles can be calculated using surface mechanomyography (sMMGpara) and electromyography (sEMGpara). However, the use of sMMGpara as an inspiratory muscle mechanical output measure, and the relationships between sMMGpara, sEMGpara, and simultaneous invasive and noninvasive pressure measurements have not previously been evaluated. sEMGpara, sMMGpara, and both invasive and noninvasive measurements of pressures were recorded in twelve healthy subjects during an inspiratory loading protocol. The ratios of sMMGpara to sEMGpara, which provided muscle-specific noninvasive NMC indices of parasternal intercostal muscles, showed nonsignificant changes with increasing load, since the relationships between sMMGpara and sEMGpara were linear (R2 = 0.85 (0.75–0.9)). The ratios of mouth pressure (Pmo) to sEMGpara and sMMGpara were also proposed as noninvasive indices of parasternal intercostal muscle NMC and MEff, respectively. These indices, similar to the analogous indices calculated using invasive transdiaphragmatic and esophageal pressures, showed nonsignificant changes during threshold loading, since the relationships between Pmo and both sEMGpara (R2 = 0.84 (0.77–0.93)) and sMMGpara (R2 = 0.89 (0.85–0.91)) were linear. The proposed noninvasive NMC and MEff indices of parasternal intercostal muscles may be of potential clinical value, particularly for the regular assessment of patients with disordered respiratory mechanics using noninvasive wearable and wireless devices.Peer ReviewedPostprint (published version

Homocistinuria y Acidemia Metilmalónica (CbIC) de evolución fatal en un recién nacido

La forma CblC de la Acidemia Metilmalónica (AMMC CbIC) es un error congénito del metabolismo intracelular de la cobalamina. Los síntomas clínicos consisten en descompensación neurológica y síntomas sistémicos. Describimos la evolución clínica y bioquímica en una paciente con inicio neonatal del defecto CblC. Recién nacido a termino, mujer, con peso al nacer de 2290 g. A los pocos día de vida presentó hipotonía, hipoactividad y succión dificultosa. Alos 13 días de vida se ingresó en UCIN presentando letargia, hipotonía, hipotermia y signos de afectación neurológica de tronco encefálico, además hiperlactacidemia y alteraciones del recuento celular. La RNM junto con los síntomas clínicos nos surgirieron una patología mitocondrial. Los ácidos orgánicos mostraron un importante aumento del ácido metilmalónico con homocistinemia y homocistinuria, sospechándose un defecto del metabolismo de la cobalamina que se comprobó in vitro. En el estudio mutacional se confirmó el diagnostico de AMM CbIC. A pesar de una buena respuesta bioquímica al tratamiento con cobalamina la paciente mantuvo un deterioro neurológico progresivo con éxitus a los 2 meses de vida. Se concluye que la AMMC, variante CblC, se puede presentar con retraso en el desarollo, lactacidemia y alteración en los parámetros hematológicos. A pesar de la normalización de los parámetros bioquímicos presentó una progresión de la enfermedad que la condujo al éxitus. Se especula la posibilidad de que existan otros factores fisiopatológicos que influyen en una mala evolución.The CblC form of methylmalonic acidemia with homocistinuria (MMA CblC) is a rare condition which results from impaired biosynthesis of methylcobalamin and adenosylcobalamin. The clinical phenotype implies neurological decompensation and systemic symptoms. We describe the clinical course and biochemical evolution of a girl with neonatal onset of the CblC variant. The female patient was delivered at term and weighed 2290 gr. The mother noticed hypotonia, hypoactivity and lack of sucking from very early on. At the 13 th day of life the patient was admitted to our hospital at the NICU. Lethargy, hypotonia, hipothermia, central ataxic breathing were the main symptoms. Initial blood profile pointed moderate hyperlactacidemia and alterations of blood cell count. RMN and the clinical profile suggested a mitochondrial disease. The metabolic profile, showed methylmalonic aciduria, with homocystinemia and homocystinuria suggesting a intracellular defect of cobalamin metabolism. The diagnosis of a MMA CbIC variant was confirmed by the propionate test in vitro and the genetic study. After treatment with cobalamin, levels of methylmalonic acid and homocysteine normalized, but the patient suffered progressive neurological deterioration with secondary multiorgan failure and death at two months of age. We conclude that Methylmalonic Aciduria with combined homocystinuria, CblC variant, may present with developmental delay, minor dysmorphology, moderate hyperlactacidemia and alteration of hematologic parameters. In spite of a normalization of biochemical parameters the disease led to a fatal outcome. We therefore think that in presence of a dysfunction of intracellular cobalamin, other physiological alterations leading to a fatal evolution might be possible

In situ monitoring of PTHLH secretion in neuroblastoma cells cultured onto nanoporous membranes

In this work, we propose for the first time the use of anodic aluminum oxide (AAO) nanoporous membranes for in situ monitoring of parathyroid hormone-like hormone (PTHLH) secretion in cultured human cells. The biosensing system is based on the nanochannels blockage upon immunocomplex formation, which is electrically monitored through the voltammetric oxidation of Prussian blue nanoparticles (PBNPs). Models evaluated include a neuroblastoma cell line (SK-N-AS) and immortalized keratinocytes (HaCaT) as a control of high PTHLH production. The effect of total number of seeded cells and incubation time on the secreted PTHLH levels is assessed, finding that secreted PTHLH levels range from approximately 60 to 400 ng/mL. Moreover, our methodology is also applied to analyse PTHLH production following PTHLH gene knockdown upon transient cell transfection with a specific silencing RNA (siRNA). Given that inhibition of PTHLH secretion reduces cell proliferation, survival and invasiveness in a number of tumors, our system provides a powerful tool for the preclinical evaluation of therapies that regulate PTHLH production. This nanoporous membrane - based sensing technology might be useful to monitor the active secretion of other proteins as well, thus contributing to characterize their regulation and function

Functionalization of a Few-Layer Antimonene with Oligonucleotides for DNA Sensing

This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Applied Nano Materials, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see: https://pubs.acs.org/doi/abs/10.1021/acsanm.0c00335Antimonene, a novel group 15 two-dimensional material, is functionalized with an oligonucleotide as a first step to DNA sensor development. The functionalization process leads to a few-layer antimonene modified with DNA that after deposition on gold screen-printed electrodes gives a simple and efficient DNA electrochemical sensing platform. We provide theoretical and experimental data of the DNA–antimonene interaction, confirming that oligonucleotides interact noncovalently but strongly with antimonene. The potential utility of this antimonene-based sensing device is assessed using, as a case of study, a sequence from the BRCA1 gene as the target DNA. The selectivity of the device allows not only recognition of a specific DNA sequence but also detection of a mutation in this gene associated with breast cancer, directly in clinical samplesThe Ministerio de Ciencia Innovación y Universidades (Grants CTQ2017-84309-C2-1-R, MAT2016-77608-C3-1-P, PCI2018-093081, JTC2017/2D-Sb&Ge, and FIS2016-80434-P), Generalitat Valenciana (Grant APOSTD/2017/010), and CAM (Grants TransNANOAVANSENS and 2017-T1/BIO-5435) are gratefully acknowledged. We also acknowledge the María de Maeztu Programme for Units of Excellence in R&D (MDM-2014-0377), the Fundación Ramón Areces, and the computer resources and assistance provided by the Centro de Computación Científica of the Universidad Autónoma de Madri