1,883 research outputs found

    Primer registro del Caracol Viajero invasor Melanoides tuberculata (Gastropoda: Thiaridae) en San Luis Potosí, México

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    Background: The species red-rimmed melania Melanoides tuberculata Müller, 1774 is native to Asia and Africa. Due to the aquarium trade, its worldwide distribution has widely increased. In Mexico, its presence in the wild has been documented since 1973 in different Mexican states. Goals: Document the first record of the presence of the species in the state of San Luis Potosí. Methods: During 2015 - 2018, different perennial water bodies were sampled in San Luis Potosí, and the presence or absence of the species was recorded. Photographic images of the exotic snail were taken for taxonomic identification and specimens collected in the study were deposited at the Colección Nacional de Moluscos – Instituto de Biología (UNAM). Results: On June 16, 2017, some individuals were found in an area near the town of San Francisco de Asís, municipality of Rioverde. Conclusions: This study contributes to the knowledge of the dispersal of the exotic red-rimmed melania in Mexico and is the first record of its presence in the state of San Luis Potosí. We consider that the current incidence of the exotic snail in the state is low. Because of its high dispersion potential, however, it could be a risk for native aquatic fauna, considering its role as an intermediate host of parasitic diseases of wild bird and fish species.Antecedentes: El caracol viajero o malasio Melanoides tuberculata Müller, 1774, es un especie dulceacuíco­la originaria de Asia y África. Esta especie de caracol se ha comercializado por la actividad de acuarismo; sin embargo, por desgracia, se han presentado liberaciones accidentales y deliberadas de individuos en lugares donde no existían, lo cual ha provocado un incremento en su distribución mundial. En México, desde 1973 se ha documentado la presencia de poblaciones silvestres en diferentes estados del país. Objetivos: Documen­tar el primer registro de la presencia de la especie en el estado de San Luis Potosí, México. Métodos: Durante los años de 2015 a 2018 fueron muestreados diferentes cuerpos de agua permanentes en el altiplano poto­sino y la región media del estado de San Luis Potosí para registrar la presencia o ausencia de la especie. En los sitios donde se registró la presencia de caracoles se procedió a colectar algunos ejemplares, los cuales fueron utilizados para las identificaciones taxonómicas y después resguardados en la Colección Nacional de Moluscos del Instituto de Biología (UNAM). Resultados: El 16 de junio de 2017 en un canal próximo al pobla­do de San Francisco de Asís, municipio de Rioverde, se registró la presencia de individuos vivos del caracol viajero. Conclusiones: El presente estudio contribuye al conocimiento de la dispersión del caracol viajero dulceacuícola exótico M. tuberculata en México y representa el primer registro de su presencia en el estado de San Luis Potosí. Consideramos que la incidencia real del caracol exótico en el estado es baja, pero debido a su alto potencial de dispersión, podría ser un riesgo para la fauna acuática nativa, ya que es un huésped intermedio de enfermedades parasitarias de aves silvestres y especies de peces

    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

    The A54T polymorphism in the FABP2 gene and its relationship with obesity

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    Introduction: Obesity is a complex, multifactorial, and mostly preventable disease affecting, along with overweight, more than a third of today’s world population. Variations in the nucleotide sequence of both metabolic and appetite control genes have been counted among these non-modifiable factors and are associated with BMI, lipidic profile, and abdominal circumference alterations. Methods: An analytical, non-experimental, and transversal research was done with the purpose to assess the presence of A54T polymorphism in the FABP gene in a sub-sample from the Maracaibo City Metabolic Syndrome Prevalence Study. Results: 154 individuals eight subjects were carriers of the A54Tpolymorphism, namely, a genotypic frequency of 5.19 %, with a sex distribution of 50 % for women (n=4) and 50 % (n=4) for men. In respect of alleles similarity degree, 75 % (n=6) were homozygous, and 25 % (n=2) were heterozygous. Obesity diagnosis throughout BMI was only present in 12.50 % (n=1) of the A54T carriers. Conversely, 25 % (n=2) of the carriers were overweighed; 50 % (n=4) were presented as normal-weight people; and only 12.50 % (n=1), in one underweighted person. Conclusion: As in many other studies, we do not find an association between Ala54Thr polymorphism and obesity. This result reinforces the fact of the multifactorial character of these diseases and a carrier state of this polymorphism is not necessarily to experience a higher obesity risk, at least, in our environment.La obesidad es una enfermedad compleja, multifactorial y en su mayor parte prevenible que afecta, a más de un tercio de la población mundial actual. Las variaciones en la secuencia de nucleótidos de los genes de control del metabolismo y del apetito se consideran hasta ahora como factores no modificables y se asocian con alteraciones del IMC, del perfil lipídico y de la circunferencia abdominal. Métodos: Se realizó una investigación analítica, no experimental y transversal con el propósito de evaluar la presencia del polimorfismo A54T en el gen FABP en una submuestra del Estudio de Prevalencia del Síndrome Metabólico de la Ciudad de Maracaibo. Resultados: De los 154 individuos de la submuestra ocho sujetos fueron portadores del polimorfismo A54T, es decir, una frecuencia genotípica de 5,19 %, con una distribución por sexo de 50 % para las mujeres (n=4) y 50 % (n=4) para los hombres. Con respecto al grado de similitud de los alelos, el 75 % (n=6) eran homocigotos y el 25 % (n=2) heterocigotos. El diagnóstico de obesidad a lo largo del IMC sólo estuvo presente en el 12,50 % (n=1) de los portadores de A54T. Por el contrario, el 25 % (n=2) de los portadores tenían sobrepeso; el 50 % (n=4) se presentaron como personas de peso normal; y sólo el 12,50 % (n=1) en la categoría de peso insuficiente. Conclusión: No se encontró una asociación entre el polimorfismo de Ala54Thr y la obesidad. Este resultado refuerza el carácter multifactorial de estas enfermedades y que un estado portador de este polimorfismo no es causa necesaria para padecer obesidad, al menos, en nuestro medio

    Ultra-deep 31.0-50.3 GHz spectral survey of IRC+10216

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    51 pags., 43 figs., 3 tabs.Context. The carbon-rich envelope of the asymptotic giant branch star CW Leo, IRC+10216, is one of the richest molecular sources in the sky. Available spectral surveys below 51 GHz are more than 25 years old, and new work is needed. Aims. Characterizing the rich molecular content of this source, specially for heavy species, requires carrying out very sensitive spectral surveys at low frequencies. In particular, we have achieved an rms in the range 0.2-0.6mK per MHz. Methods. Long Q band (31.0-50.3 GHz) single-dish integrations were carried out with the Yebes-40m telescope using specifically built receivers. The most recent line catalogs were used to identify the lines. Results. The data contain 652 spectral features, corresponding to 713 transitions from 81 species (we count the isomers, isotopologs, and ortho/para species separately). Only 57 unidentified lines remain with signal-to-noise ratios ≤3. Some new species and/or vibrational modes have been discovered for the first time with this survey. Conclusions. This IRC+10216 spectral survey is by far the most sensitive survey carried out to date in the Q band. It therefore provides the most complete view of IRC+10216 from 31.0 to 50.3 GHz, giving unique information about its molecular content, especially for heavy species. Rotational diagrams built from the data provide valuable information about the physical conditions and chemical content of this circumstellar envelope.We thank Ministerio de Ciencia e Innovación of Spain for funding support through projects PID2019-106110GB-I00, PID2019- 107115GB-C21/AEI/10.13039/501100011033, PID2019-106235GB-I00, and grant FJCI-2016-27983 for CB. We also thank ERC for funding through grant ERC-2013-Syg-610256-NANOCOSMOS. M.A. thanks MICIU for grant RyC2014-16277

    Scutoids are a geometrical solution to three-dimensional packing of epithelia

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    As animals develop, tissue bending contributes to shape the organs into complex three-dimensional structures. However, the architecture and packing of curved epithelia remains largely unknown. Here we show by means of mathematical modelling that cells in bent epithelia can undergo intercalations along the apico-basal axis. This phenomenon forces cells to have different neighbours in their basal and apical surfaces. As a consequence, epithelial cells adopt a novel shape that we term “scutoid”. The detailed analysis of diverse tissues confirms that generation of apico-basal intercalations between cells is a common feature during morphogenesis. Using biophysical arguments, we propose that scutoids make possible the minimization of the tissue energy and stabilize three-dimensional packing. Hence, we conclude that scutoids are one of nature's solutions to achieve epithelial bending. Our findings pave the way to understand the three-dimensional organization of epithelial organs

    Perfiles serológicos de hepatitis B en donantes de sangre con anti-HBc reactivos

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    Objetivo Determinar los perfiles serológicos para el virus de hepatitis B, en donantes de sangre anti-HBc reactivo y antígeno de superficie no reactivo, provenientes de cuatro ciudades del paísMétodos Se realizó un estudio prospectivo transversal, durante un período de 17 meses, aplicando el perfil serológico completo de la hepatitis B, en muestras de donantes con anti-HBc reactivo y antígeno de superficie de hepatitis B no reactivo. Los resultados fueron analizados utilizando Microsoft® Excel y Epiinfo V 3.5.1.Resultados Se encontró que el 75 % de los donantes reactivos para anti-HBc en los bancos de sangre, presentaban algún marcador adicional de exposición para el VHB; el 1,3 % de los donantes presentaban marcadores serológicos de infección crónica por hepatitis B y un caso que resultó reactivo solamente para antígeno de superficie de hepatitis B. Se halló perfil de vacunación en el 6,1 % de donantes, que fueron reactivos solamente para anticuerpo contra antígeno de superficie.Conclusiones. Se ratifica la importancia de la tamización de anti-HBc, a los donantes de sangre

    Role of Endocrine-Disrupting Chemicals in the Pathogenesis of Non-Alcoholic Fatty Liver Disease: A Comprehensive Review

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    Non-alcoholic fatty liver disease (NAFLD) is considered the most common liver disorder, affecting around 25% of the population worldwide. It is a complex disease spectrum, closely linked with other conditions such as obesity, insulin resistance, type 2 diabetes mellitus, and metabolic syndrome, which may increase liver-related mortality. In light of this, numerous efforts have been carried out in recent years in order to clarify its pathogenesis and create new prevention strategies. Currently, the essential role of environmental pollutants in NAFLD development is recognized. Particularly, endocrine-disrupting chemicals (EDCs) have a notable influence. EDCs can be classified as natural (phytoestrogens, genistein, and coumestrol) or synthetic, and the latter ones can be further subdivided into industrial (dioxins, polychlorinated biphenyls, and alkylphenols), agricultural (pesticides, insecticides, herbicides, and fungicides), residential (phthalates, polybrominated biphenyls, and bisphenol A), and pharmaceutical (parabens). Several experimental models have proposed a mechanism involving this group of substances with the disruption of hepatic metabolism, which promotes NAFLD. These include an imbalance between lipid influx/efflux in the liver, mitochondrial dysfunction, liver inflammation, and epigenetic reprogramming. It can be concluded that exposure to EDCs might play a crucial role in NAFLD initiation and evolution. However, further investigations supporting these effects in humans are required

    Author Correction: Scutoids are a geometrical solution to three-dimensional packing of epithelia.

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    The original version of this Article contained an error in ref. 39, which incorrectly cited 'Fristrom, D. & Fristrom, J. W. in The Development of Drosophila melanogaster (eds. Bate, M. & Martinez-Arias, A.) II, (Cold spring harbor laboratory press, 1993)'. The correct reference is 'Condic, M.L, Fristrom, D. & Fristrom, J.W. Apical cell shape changes during Drosophila imaginal leg disc elongation: a novel morphogenetic mechanism. Development 111: 23-33 (1991)'. Furthermore, the last sentence of the fourth paragraph of the introduction incorrectly omitted citation of work by Rupprecht et al. The correct citation is given below. These errors have now been corrected in both the PDF and HTML versions of the Article. Rupprecht, J.F., Ong, K.H., Yin, J., Huang, A., Dinh, H.H., Singh, A.P., Zhang, S., Yu, W. & Saunders, T.E. Geometric constraints alter cell arrangements within curved epithelial tissues. Mol. Biol. Cell 28, 3582-3594 (2017)
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