Leptospira spp y leptospirosis humana

Resumen Introducción. La leptospirosis, enfermedad bacteriana zoonótica y emergente más importante en el mundo, es causada por las especies patógenas de Leptospira spp. Objetivo. Revisar información reciente sobre Leptospira spp. y  leptospirosis humana con énfasis en América y Colombia. Metodología. Revisión de artículos indexados en PubMed, relacionados con la microbiología,  epidemiología, presentación clínica en humanos, diagnostico, tratamiento y prevención  de la enfermedad (vacunas). Resultados. Veinte especies de Leptospira spp han sido descritas;  se ha determinado la secuencia del ADN genómico de algunas cepas patógenas, la función de la mayoría de los genes involucrados en su patogénesis permanece desconocida. La leptospirosis humana presenta un rango de síntomas que van desde una fiebre indiferenciada hasta una ictericia, hemorragia, fallas renales y pulmonares severas. La administración temprana e intravenosa de penicilina G es requerida para reducir las tasas de mortalidad, pero los antibióticos pueden no ser efectivos en la enfermedad pulmonar severa. En las Americas, las areas de alto riesgo son Brasil, Centro América y el Caribe. Pocos estudios han sido  realizados en Colombia. La prueba serológica de oro, la microaglutinación  tiene alta sensibilidad y especificidad cuando se usan baterías de serovariedades locales pero es serogrupo específica. Las vacunas generan respuestas específicas para la serovariedad usada, pero no previenen la infección o trasmisión. Conclusiones. Problemas en el diagnóstico de laboratorio de la leptospirosis conllevan a un sub-registro en el número de casos; altas tasas de mortalidad asociadas a  fallas renal y pulmonar son resultado de las dificultades en el manejo de los casos

Information Quality in Latin American Digital Native Media: Analysis Based on Structured Dimensions and Indicators

The current communicative ecosystem has profoundly transformed journalistic work and the media, generating with great eagerness the emergence of digital native media that do not follow the logic of their conventional peers. Although the advent of these media is not entirely negative, as they create multiple voices that contribute to pluralism, their quality has undoubtedly been questioned on several academic fronts. This work analyzes the most important Latin American digital native media by number of accesses (traffic), using a taxonomy of evaluation of dimensions of the informative quality, in which aspects such as informative sources, uses of international news agencies, correction of contents and factuality levels, ideological plurality in their opinion contents, among others, are taken into consideration. Of the emerging results, the ‘use of statistical indicators’ was the least rated (32.5%), mainly due to a lack of data journalism in the media studied. It is also worth noting that the indicator ‘comments and monitoring’ obtained the second-lowest rating, indicating an absence of conversation between the media and its audience through the comments section of each content

Antioxidant Capacity and Antimicrobial Activity of Commercial Samples of Guava Leaves (\u3cem\u3ePsidium guajava\u3c/em\u3e)

Psidium guajava is a small tree native to South and Central America. Guava leaves have traditionally been used for treating different illnesses. These benefits can be attributed to phenolics and flavonoids produced by guava. The chemical composition of guava leaf extracts was correlated with biological activity. Total phenolics, total flavonoids, ABTS/DPPH, TZM-bl, plaque reduction, XTT, spectrophotometric and Kirby-Bauer assays were used to test phenols, flavonoids, antioxidant properties, antiviral activity, cytotoxicity, and antibacterial activity, respectively. The median cytotoxicity concentration and half-maximal effective concentration values were obtained in order to determine antiviral selectivity against human immunodeficiency virus type 1 and herpes simplex virus type 1. Antibacterial activity against Escherichia coli and Bacillus subtilis were evaluated using a spectrophotometric assay and Kirby-Bauer test. The guava leaf extracts had a high phenol (0.8 to 2.1 GAE mg/mL) and flavonoid (62.7 to 182.1 Rutin Eq mg/g DW) content that correlated with high antioxidant capacity and selective antiviral activity (therapeutic index values above 10). Results of antibacterial tests indicated that the extracts have activity against gram-negative and gram-positive bacteria

Long-Chain Acyl Coenzyme A Synthetase 1 Overexpression in Primary Cultured Schwann Cells Prevents Long Chain Fatty Acid-Induced Oxidative Stress and Mitochondrial Dysfunction

Aims: High circulating long chain fatty acids (LCFAs) are implicated in diabetic neuropathy (DN) development. Expression of the long-chain acyl-CoA synthetase 1 (Acsl1) gene, a gene required for LCFA metabolic activation, is altered in human and mouse diabetic peripheral nerve. We assessed the significance of Acsl1 upregulation in primary cultured Schwann cells. Results: Acsl1 overexpression prevented oxidative stress (nitrotyrosine; hydroxyoctadecadienoic acids [HODEs]) and attenuated cellular injury (TUNEL) in Schwann cells following 12?h exposure to LCFAs (palmitate, linoleate, and oleate, 100??M). Acsl1 overexpression potentiated the observed increase in medium to long-chain acyl-carnitines following 12?h LCFA exposure. Data are consistent with increased mitochondrial LCFA uptake, largely directed to incomplete beta-oxidation. LCFAs uncoupled mitochondrial oxygen consumption from ATP production. Acsl1 overexpression corrected mitochondrial dysfunction, increasing coupling efficiency and decreasing proton leak. Innovation: Schwann cell mitochondrial function is critical for peripheral nerve function, but research on Schwann cell mitochondrial dysfunction in response to hyperlipidemia is minimal. We demonstrate that high levels of a physiologically relevant mixture of LCFAs induce Schwann cell injury, but that improved mitochondrial uptake and metabolism attenuate this lipotoxicity. Conclusion: Acsl1 overexpression improves Schwann cell function and survival following high LCFA exposure in vitro; however, the observed endogenous Acsl1 upregulation in peripheral nerve in response to diabetes is not sufficient to prevent the development of DN in murine models of DN. Therefore, targeted improvement in Schwann cell metabolic disposal of LCFAs may improve DN phenotypes. Antioxid. Redox Signal. 21, 588?600.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140243/1/ars.2013.5248.pd

Genome-Wide DNA Methylation Profiling of Human Diabetic Peripheral Neuropathy in Subjects with Type 2 Diabetes Mellitus

DNA methylation is an epigenetic mechanism important for the regulation of gene expression, which plays a vital role in the interaction between genetic and environmental factors. Aberrant epigenetic changes are implicated in the pathogenesis of diabetes and diabetic complications, but the role of DNA methylation in diabetic peripheral neuropathy (DPN) is not well understood. Therefore, our aim in this study was to explore the role of DNA methylation in the progression of DPN in type 2 diabetes. We compared genome-wide DNA methylation profiles of human sural nerve biopsies from subjects with stable or improving nerve fibre counts to biopsies from subjects with progressive loss of nerve fibres. Nerve fibre counts were determined by comparing myelinated nerve fibre densities between an initial and repeat biopsy separated by 52 weeks. Subjects with significant nerve regeneration (regenerators) and subjects with significant nerve degeneration (degenerators) represent the two extreme DPN phenotypes. Using reduced representation bisulfite sequencing, we identified 3,460 differentially methylated CpG dinucleotides between the two groups. The genes associated with differentially methylated CpGs were highly enriched in biological processes that have previously been implicated in DPN such as nervous system development, neuron development, and axon guidance, as well as glycerophospholipid metabolism and mitogen-activated protein kinase (MAPK) signalling. These findings are the first to provide a comprehensive analysis of DNA methylation profiling in human sural nerves of subjects with DPN and suggest that epigenetic regulation has an important role in the progression of this prevalent diabetic complication

Genome sequence alterations detected upon passage of Burkholderia mallei ATCC 23344 in culture and in mammalian hosts

BACKGROUND: More than 12,000 simple sequence repeats (SSRs) have been identified in the genome of Burkholderia mallei ATCC 23344. As a demonstrated mechanism of phase variation in other pathogenic bacteria, these may function as mutable loci leading to altered protein expression or structure variation. To determine if such alterations are occurring in vivo, the genomes of various single-colony passaged B. mallei ATCC 23344 isolates, one from each source, were sequenced from culture, a mouse, a horse, and two isolates from a single human patient, and the sequence compared to the published B. mallei ATCC 23344 genome sequence. RESULTS: Forty-nine insertions and deletions (indels) were detected at SSRs in the five passaged strains, a majority of which (67.3%) were located within noncoding areas, suggesting that such regions are more tolerant of sequence alterations. Expression profiling of the two human passaged isolates compared to the strain before passage revealed alterations in the mRNA levels of multiple genes when grown in culture. CONCLUSION: These data support the notion that genome variability upon passage is a feature of B. mallei ATCC23344, and that within a host B. mallei generates a diverse population of clones that accumulate genome sequence variation at SSR and other loci

Glycerol Valorization towards a Benzoxazine Derivative through a Milling and Microwave Sequential Strategy

Glycerol and aminophenol intermolecular condensation has been investigated through a milling and microwave-assisted sequential strategy, towards the synthesis of a benzoxaxine derivative. Mechanochemical activation prior to the microwave-assisted process could improve the probability of contact between the reagents, and greatly favors the higher conversion of aminophenol. At the same time, following a mechanochemical–microwave sequential approach could tune the selectivity towards the formation of a benzoxazine derivative, which could find application in a wide range of biomedical area

Evaluación del bienestar animal por medio De indicadores conductuales durante el Sacrificio de bovinos

La legislación Colombiana establece los lineamientos para el sacrificio de bovinos, el cual debe garantizar un procedimiento humanitario, además de cumplir con ciertos parámetros de calidad del producto final. El objetivo del estudio fue evaluar la eficiencia en la insensibilización en dos plantas de sacrificio como indicador de bienestar animal. Se evaluó la insensibilización de 1343 bovinos. Como variables se emplearon los signos de pérdida de sensibilidad (reflejo corneal, intentos de incorporarse, vocalizaciones y respiración rítmica) e indicadores conductuales de pérdida de Bienestar Animal (BA) (resbalones, caídas, vocalizaciones, saltos y marcha hacia atrás). Se midió el tiempo de retraso en la insensibilización, el número de disparos por animal, la localización correcta del impacto y el tiempo entre insensibilización y sangría. El 96.5% de los bovinos colapsaron inmediatamente después de recibir el primer impacto, sin embargo, el 23.6% (n=307) de éstos recuperó la sensibilidad antes de la sangría, debido al amplio intervalo de tiempo entre la insensibilización y la sangría superior a los 60 segundos (98.7%). Se encontró asociación significativa entre el retraso en la insensibilización y el número de eventos conductuales (p<0.01). Asimismo, se hallaron diferencias para los indicadores conductuales entre las plantas de sacrificio (p<0.01), encontrándose mayor incidencia en la planta A, la cual contaba con un método de sujeción de cabeza en el cajón de insensibilización, pero no de cuerpo. De otra parte, se observaron malas prácticas de manejo y conducción de los animales en la planta B como sujetar y empujar el animal con la picana eléctrica. Se concluye que en las plantas evaluadas el bienestar animal durante el sacrificio de bovinos es deficiente, se hace necesario la capacitación del personal, mejoras en la infraestructura y la implementación de indicadores de evaluación. AbstractColombian laws establish the guidelines for slaughtering of cattle which have to f guarantee a humane procedure, besides complying with some quality parameters for the final product. The objective of this study was to evaluate efficiency of the stunning process in two slaughterhouses as an indicator of animal welfare. Stunning was evaluated in 1343 bovines. Signs of loss of consciousness (corneal reflex, attempts to head up, vocalizations and rhythmic breathing) as well as behavioral indicators of Animal Welfare (AW) loss (slipping, falling, vocalizations, jumping and backward movements) were assessed to identify animal welfare standards. Besides, the stunning delay, the number of shots per animal, the appropriate location of the shots and the interval between shot and bleeding were measured. Although, 98.5% of animals collapsed immediately after receiving the first shot, 23.6% (n=307) recovered sensitivity before bleeding, because of the wide interval between stunning and bleeding which was higher than 60 seconds (98.7%). There was a significant association between stunning delay and the number of behavioral events counted (p<0.01). Moreover, differences in the behavioral indicators among the slaughterhouses evaluated were found (p<0.01) showing greater incidence in slaughter house “A” which had a head fixation system, but not one to hold still the entire body of the animal. Aversive behavioral responses were encountered in plant “B”, such as the use of cattle prods to hold and push the animal while it was in the stunning box. The results indicate that in the slaughterhouses evaluated animal welfare during slaughtering is defficient and it is necessary to implement personnel training, improvement of infrastructure and evaluation indicators. La legislación Colombiana establece los lineamientos para el sacrificio de bovinos, el cual debe garantizar un procedimiento humanitario, además de cumplir con ciertos parámetros de calidad del producto final. El objetivo del estudio fue evaluar la eficiencia en la insensibilización en dos plantas de sacrificio como indicador de bienestar animal. Se evaluó la insensibilización de 1343 bovinos. Como variables se emplearon los signos de pérdida de sensibilidad (reflejo corneal, intentos de incorporarse, vocalizaciones y respiración rítmica) e indicadores conductuales de pérdida de Bienestar Animal (BA) (resbalones, caídas, vocalizaciones, saltos y marcha hacia atrás). Se midió el tiempo de retraso en la insensibilización, el número de disparos por animal, la localización correcta del impacto y el tiempo entre insensibilización y sangría. El 96.5% de los bovinos colapsaron inmediatamente después de recibir el primer impacto, sin embargo, el 23.6% (n=307) de éstos recuperó la sensibilidad antes de la sangría, debido al amplio intervalo de tiempo entre la insensibilización y la sangría superior a los 60 segundos (98.7%). Se encontró asociación significativa entre el retraso en la insensibilización y el número de eventos conductuales (p<0.01). Asimismo, se hallaron diferencias para los indicadores conductuales entre las plantas de sacrificio (p<0.01), encontrándose mayor incidencia en la planta A, la cual contaba con un método de sujeción de cabeza en el cajón de insensibilización, pero no de cuerpo. De otra parte, se observaron malas prácticas de manejo y conducción de los animales en la planta B como sujetar y empujar el animal con la picana eléctrica. Se concluye que en las plantas evaluadas el bienestar animal durante el sacrificio de bovinos es deficiente, se hace necesario la capacitación del personal, mejoras en la infraestructura y la implementación de indicadores de evaluación. AbstractColombian laws establish the guidelines for slaughtering of cattle which have to f guarantee a humane procedure, besides complying with some quality parameters for the final product. The objective of this study was to evaluate efficiency of the stunning process in two slaughterhouses as an indicator of animal welfare. Stunning was evaluated in 1343 bovines. Signs of loss of consciousness (corneal reflex, attempts to head up, vocalizations and rhythmic breathing) as well as behavioral indicators of Animal Welfare (AW) loss (slipping, falling, vocalizations, jumping and backward movements) were assessed to identify animal welfare standards. Besides, the stunning delay, the number of shots per animal, the appropriate location of the shots and the interval between shot and bleeding were measured. Although, 98.5% of animals collapsed immediately after receiving the first shot, 23.6% (n=307) recovered sensitivity before bleeding, because of the wide interval between stunning and bleeding which was higher than 60 seconds (98.7%). There was a significant association between stunning delay and the number of behavioral events counted (p<0.01). Moreover, differences in the behavioral indicators among the slaughterhouses evaluated were found (p<0.01) showing greater incidence in slaughter house “A” which had a head fixation system, but not one to hold still the entire body of the animal. Aversive behavioral responses were encountered in plant “B”, such as the use of cattle prods to hold and push the animal while it was in the stunning box. The results indicate that in the slaughterhouses evaluated animal welfare during slaughtering is defficient and it is necessary to implement personnel training, improvement of infrastructure and evaluation indicators.

Invoking Chiral Vector Leptoquark to explain LFU violation in B Decays

LHCb has recently reported more than $2\sigma$ deviation from the Standard Model prediction in the observable $R_{J/\psi}$. We study this anomaly in the framework of a vector leptoquark along with other lepton flavor universality violating measurements which include $R_{K^{(*)}}$, and $R_{D^{(*)}}$. We show that a chiral vector leptoquark can explain all the aforementioned anomalies consistently while also respecting other experimental constraints

Early life metal dysregulation in amyotrophic lateral sclerosis

ObjectiveDeficiencies and excess of essential elements and toxic metals are implicated in amyotrophic lateral sclerosis (ALS), but the age when metal dysregulation appears remains unknown. This study aims to determine whether metal uptake is dysregulated during childhood in individuals eventually diagnosed with ALS.MethodsLaser ablation- inductively coupled plasma- mass spectrometry was used to obtain time series data of metal uptake using biomarkers in teeth from autopsies or dental extractions of ALS (n = 36) and control (n = 31) participants. Covariate data included sex, smoking, occupational exposures, and ALS family history. Case- control differences were identified in temporal profiles of metal uptake for individual metals using distributed lag models. Weighted quantile sum (WQS) regression was used for metals mixture analyses. Similar analyses were performed on an ALS mouse model to further verify the relevance of dysregulation of metals in ALS.ResultsMetal levels were higher in cases than in controls: 1.49 times for chromium (1.11- 1.82; at 15 years), 1.82 times for manganese (1.34- 2.46; at birth), 1.65 times for nickel (1.22- 2.01; at 8 years), 2.46 times for tin (1.65- 3.30; at 2 years), and 2.46 times for zinc (1.49- 3.67; at 6 years). Co- exposure to 11 elements indicated that childhood metal dysregulation was associated with ALS. The mixture contribution of metals to disease outcome was likewise apparent in tooth biomarkers of an ALS mouse model, and differences in metal distribution were evident in ALS mouse brains compared to brains from littermate controls.InterpretationOverall, our study reveals direct evidence that altered metal uptake during specific early life time windows is associated with adult- onset ALS.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155978/1/acn351006_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155978/2/acn351006.pd