553 research outputs found

    The chromatin remodeling factor CHD8 interacts with elongating RNA polymerase II and controls expression of the cyclin E2 gene

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    CHD8 is a chromatin remodeling ATPase of the SNF2 family. We found that depletion of CHD8 impairs cell proliferation. In order to identify CHD8 target genes, we performed a transcriptomic analysis of CHD8-depleted cells, finding out that CHD8 controls the expression of cyclin E2 (CCNE2) and thymidylate synthetase (TYMS), two genes expressed in the G1/S transition of the cell cycle. CHD8 was also able to co-activate the CCNE2 promoter in transient transfection experiments. Chromatin immunoprecipitation experiments demonstrated that CHD8 binds directly to the 5′ region of both CCNE2 and TYMS genes. Interestingly, both RNA polymerase II (RNAPII) and CHD8 bind constitutively to the 5′ promoter-proximal region of CCNE2, regardless of the cell-cycle phase and, therefore, of the expression of CCNE2. The tandem chromodomains of CHD8 bind in vitro specifically to histone H3 di-methylated at lysine 4. However, CHD8 depletion does not affect the methylation levels of this residue. We also show that CHD8 associates with the elongating form of RNAPII, which is phosphorylated in its carboxy-terminal domain (CTD). Furthermore, CHD8-depleted cells are hypersensitive to drugs that inhibit RNAPII phosphorylation at serine 2, suggesting that CHD8 is required for an early step of the RNAPII transcription cycle

    Thermal and current flow effects of a capacitive–resistive electric transfer application protocol on chronic elbow tendinopathy. A cadaveric study

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    Lateral elbow tendinopathy, or “tennis elbow”, is a pathology that affects around 1.3% of the general population. Capacitive–resistive electric transfer therapy aims to provoke temperature and current flow changes in superficial and deep tissues. The aim of this in vitro study was to analyze the thermal behavior and transmission of electric current on the superficial and deep tissues of the elbow during the application of different modalities of a capacitive–resistive electric transfer treatment protocol for chronic elbow tendinopathy. A cross-sectional study was designed; five fresh cryopreserved cadavers (10 elbows) were included in this study. A 30 min intervention was performed based on a protocol commonly used in clinics for the treatment of chronic lateral elbow tendinopathy by diathermy using the “T-Plus.” Common extensor tendon, radiohumeral capsule, and superficial temperatures were registered after each application for the duration of the 30 min treatment protocol. During all applications, we observed a current flow of over 0.03 A. The protocol showed a statistically significant increase in superficial temperature by 24% (5.02¿) (p < 0.005), the common extensor tendon by 19.7% (4.36¿) (p < 0.007), and the radiohumeral joint capsule by 17.5% (3.41¿) (p < 0.005) at the end of the 30 min protocol compared with the baseline temperature. The different applications of the protocol showed specific effects on the temperature and current flow in the common extensor tendon and radiohumeral capsule. All applications of the protocol produced a current flow that is associated with the generation of cell proliferation. These results strengthen the hypothesis of cell proliferation and thermal changes in deep and distal structures. More studies are needed to confirm these results

    A simulational and theoretical study of the spherical electrical double layer for a size-asymmetric electrolyte: the case of big coions

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    Monte Carlo simulations of a spherical macroion, surrounded by a size-asymmetric electrolyte in the primitive model, were performed. We considered 1:1 and 2:2 salts with a size ratio of 2 (i.e., with coions twice the size of counterions), for several surface charge densities of the macrosphere. The radial distribution functions, electrostatic potential at the Helmholtz surfaces, and integrated charge are reported. We compare these simulational data with original results obtained from the Ornstein-Zernike integral equation, supplemented by the hypernetted chain/hypernetted chain (HNC/HNC) and hypernetted chain/mean spherical approximation (HNC/MSA) closures, and with the corresponding calculations using the modified Gouy-Chapman and unequal-radius modified Gouy-Chapman theories. The HNC/HNC and HNC/MSA integral equations formalisms show good concordance with Monte Carlo "experiments", whereas the notable limitations of point-ion approaches are evidenced. Most importantly, the simulations confirm our previous theoretical predictions of the non-dominance of the counterions in the size-asymmetric spherical electrical double layer [J. Chem. Phys. 123, 034703 (2005)], the appearance of anomalous curvatures at the outer Helmholtz plane and the enhancement of charge reversal and screening at high colloidal surface charge densities due to the ionic size asymmetry.Comment: 11 pages, 7 figure

    Flavonoid and Capsaicinoid Contents and Consumption of Mexican Chili Pepper (Capsicum annuum L.) Landraces

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    There is insufficient evidence to identify the precise health effects of chili pepper consumption. However, there is evidence of their topical use as an analgesic to decrease pain from rheumatoid arthritis, osteoarthritis, neuralgias, neuropathic diabetes, neuronal dysfunctions and inflammation, among others. In this work, the diversity and variety of consumed forms of chilis in Mexico, flavonoid and capsaicinoid content in fruits, and their potential health uses are documented, based on various research results and bibliographic information. In Mexico, more than 150 landraces of wild and cultivated origins are consumed and preserved and are distributed throughout the country; the greatest diversity is concentrated in the central and south-southeastern regions. Consumption per capita in urban households is from 8 to 9 kg, and in rural communities, it varies from 14 to 17 kg. Chili peppers contain up to 23 flavonoids and 20 capsaicinoids, differing among landraces because of crop management, maturation of fruits, postharvest management and ecological-environmental influences. Flavonoids and capsaicinoids confer antioxidant, anticarcinogenic properties on the fruit and have lipolytic and preventative effects on chronic degenerative diseases. However, in vitro and in vivo experimental trials of capsaicinoids and flavonoids with beneficial effects must be conducted with regard to human health

    Factores de riesgo asociados a la seroprevalencia de lentivirus en rebaños ovinos y caprinos del noreste de México

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    A cross-sectional study was conducted with the purpose of determinate the risk factors associated with the serological frequency of small ruminant lentivirus (SRLV) in sheep and goats from northeastern Mexico. From 128 herds, 71 of goats, 32 of sheep and 25 mixed herds (goats + sheep), 768 individual sera were collected from animals ≥1 yr old. From each herd, 4 to 5 serum samples were mixed and analyzed by ELISA to identify antibodies against SRLV glycoprotein 135. Samples were obtained from randomly selected animals in 2019 and 2020. A questionnaire was applied to the producers and the data were analyzed to determine the risk factors associated with herd seropositivity by logistic regression. The proportion of seropositive herds, overall, was estimated at 50.6 %. According to the type of herd, seropositivity in goat herds was 62.0 %, in sheep herds 25.4 % and 50.2 % in mixed herds. The risk factors associated with the presence of antibodies against SRLV were the presence of animals with arthritis, veterinary care, reuse of needles, nerve alterations, low pregnancy rate, type of herd and mastitis. Serological frequency indicates a high endemicity of SRLV in small ruminant herds from northeastern Mexico.Se realizó un estudio transversal con el propósito de determinar los factores de riesgo asociados a la frecuencia serológica de Lentivirus de los pequeños rumiantes (LvPR) en ovinos y caprinos del noreste de México. De 128 rebaños, 71 de caprinos, 32 de ovinos y 25 mixtos (caprinos + ovinos), se recolectaron 768 sueros individuales de animales ≥1 año de edad. De cada rebaño 4 a 5 muestras de suero fueron mezcladas y analizadas por ELISA para identificar anticuerpos contra la glucoproteína 135 del LvPR. Las muestras se obtuvieron de animales seleccionados al azar en los años 2019 y 2020. Se aplicó un cuestionario a los productores y los datos se analizaron para determinar los factores de riesgo asociados a la seropositividad del rebaño mediante regresión logística. La proporción de rebaños seropositivos en general fue estimada en 50.6 %. Acorde al tipo de rebaño la seropositividad en rebaños caprinos fue de 62.0 %, en ovinos de 25.4 % y de 50.2 % en rebaños mixtos. Los factores de riesgo asociados a la presencia de anticuerpos contra el LvPR fueron presencia de animales con artritis, asistencia veterinaria, reutilizar agujas, alteraciones nerviosas, bajo índice de preñez, tipo de rebaño y mastitis. La frecuencia serológica indica una alta endemicidad del LvPR en rebaños de pequeños rumiantes del noreste de México

    SEROPREVALENCIA DE Toxoplasma gondii EN LLAMAS DE DOS FUNDOS GANADEROS DE LA PROVINCIA DE MELGAR, PUNO

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    El objetivo del estudio fue determinar la seroprevalencia del Toxoplasma gondii en llamas hembras de dos fundos ganaderos de la provincia de Melgar, Puno. Se colectaron sueros sanguíneos de 284 animales para la detección de anticuerpos mediante el método de Inmunofluorescencia Indirecta (IFI). El 47.5 ± 5.8% (135/284) del total de las muestras presentaron anticuerpos. La frecuencia de reactores se incrementó en relación directa con la edad de los animales (nacimiento-2 años: 33.8 ± 11.0%; >2 a 4 años: 51.2 ± 10.8; >4 a 6 años: 56.8 ± 14.6%; y >6 años: 50.6 ± 10.5%). Se encontraron diferencias estadísticas (p<0.05) en la frecuencia de reactores entre fundos. Además, se halló que la variable edad y zona de muestreo representan un factor de riesgo para la infección con T. gondii (p<0.0001).The aim of this study was to determine the seroprevalence of Toxoplasma gondii in female llamas from two farms located in the Melgar province, Puno. A total of 284 blood samples were tested using the indirect immunofluorescence test (IFAT) to detect antibodies against T. gondii. The results showed that 47.5 + 5.8% (135/284) of the samples had antibodies and they increased with age. The seroprevalence from birth till 2 years, 2- 4 years, >4-6 years, and >6 years was 33.8 ± 11.0, 51.2 ± 10.8, 56.8 ± 14.6, and 50.6 ± 10.5%, respectively. There were significant differences (p<0.05) in the frecuency of female reactors between farms. Age and farm variables were considered as risk factors for the infection with Toxoplasma gondii (p<0.0001)

    Electron transport measurements in liquid xenon with Xenoscope, a large-scale DARWIN demonstrator

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    The DARWIN observatory is a proposed next-generation experiment with 40 tonnes of liquid xenon as an active target in a time projection chamber. To study challenges related to the construction and operation of a multi-tonne scale detector, we have designed and constructed a vertical, full-scale demonstrator for the DARWIN experiment at the University of Zurich. Here, we present the first results from a several-months run with 343kg of xenon and electron drift lifetime and transport measurements with a 53cm tall purity monitor immersed in the cryogenic liquid. After 88days of continuous purification, the electron lifetime reached a value of (664±23)μs. We measured the drift velocity of electrons for electric fields in the range (25–75) V/cm, and found values consistent with previous measurements. We also calculated the longitudinal diffusion constant of the electron cloud in the same field range, and compared with previous data, as well as with predictions from an empirical model

    Reconstrucción de la evolución molecular de la infección actual por el virus linfotrópico humano tipo I en Colombia.

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    The human T-lymphotropic virus type I (HTLV-I) infection is a public health problem in many endemic areas of Colombia. The subtyping of HTLV-I was based on the analysis of restriction fragment length polymorphisms (RFLP) in 3'LTR proviral DNA. From 31 HTLV-I isolates collected throughout Colombia, a RFLP analysis in a 737 bp 3'LTR fragment was performed. Fifty-eight percent (18/31) were identified as the Cosmopolitan subtype a, 19.4% (6/31) in the West African subtype b, 12.9% (4/31) in the Cosmopolitan subtype b and 9.6% (3/31) in the West African subtype c. The phylogenetic analysis of 3'LTR nucleotide sequences indicated that all the isolates in the current study were in the subgroup B or Japanese, in contrast with the highly divergent isolates from native Amerindians grouped in subgroup a or Transcontinental. The supported hypothesis was that of a post-Columbus introduction of virus represented in the African-American communities of the Colombian South Pacific. Some viral isolates from Colombian native Amerindians exhibited a nucleotide variation compatible with a Paleolithic introduction of the virus. The genetic diversity of HTLV-I in Colombia is complex and probably represents several independent introductions of lymphotropic virus.La infección por el virus linfotrópico humano tipo I (HTLV-I) es un problema de salud pública en varias zonas endémicas de Colombia. La subtipificación del HTLV-I se basa en los análisis de polimorfismos en el tamaño de fragmentos de restricción (RFLP) de la región 3?LTR del ADN proviral. A partir de 31 aislamientos de HTLV-I recolectados en diferentes regiones del territorio nacional se realizó un análisis de RFLP en un fragmento de ADN de 737 pb de la región LTR. El 58,1% (18/31) se incluyó dentro del subtipo Cosmopolita a; el 19,4% (6/31) en el Africano b; el 12,9% (4/31) en el Cosmopolita b, y el 9,6% (3/31) en el Africano c. Con base en análisis filogenéticos de secuencias nucleotídicas del 3?LTR, se demostró que los aislamientos colombianos incluidos en este trabajo se ubicaron dentro del subgrupo B o japonés, lo cual muestra gran divergencia con aquellos aislamientos de indígenas colombianos previamente reportados que se incluyeron dentro del subgrupo A o transcontinental. Nuestros datos apoyan la hipótesis de una introducción poscolombina del HTLV-I a Colombia que estaría representada en las comunidades negras de la costa del Pacífico del sur de Colombia que tuvieron ancestros africanos. Algunos aislamientos virales de indígenas colombianos mostraron una variación nucleotídica compatible con una introducción paleolítica. En su conjunto, los resultados obtenidos permiten postular que la actual diversidad genética del HTLV-I en Colombia es compleja y es el resultado de varios eventos de introducción, temporalmente separados
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