253 research outputs found
Inclusiones parasitarias compatibles con Ehrlichia spp. Y Hepatozoon canis concomitantes en un neutrófilo
Se describe el caso clínico de una Cócker de 5 años de edad que llegó a nuestro centro veterinario con sintomatología compatible con ehrlichiosis, detectándose, en un frotis sanguíneo, la presencia en un mismo neutrófilo de una mórula de Ehrlichia y un gametocito de Hepatozoon canis. El animal respondió favorablemente al tratamiento con doxiciclina, dipropionato de imidocarb y atropina. La última reorganización taxonómica del género Ehrlichia ha dividido este género en tres; género Anaplasma, género Neorickettsia y género Ehrlichia, de forma que el clínico veterinario debe conocer las especies de Ehrlichia más frecuentes en su zona de trabajo, la sintomatología asociada y los hallazgos de laboratorio típicos de cada especie para poder llegar a un diagnóstico etiológico final de ehrlichiosis. La serología (junto a otras pruebas de laboratorio) es el método más utilizado para el diagnóstico final de ehrlichiosis, siendo necesario conocer bien sus beneficios y limitaciones porque nos puede llevar a diagnosticar fundamentalmente, falsos negativos. Además, es difícil saber con exactitud qué especie de Ehrlichia ha provocado la enfermedad debido a las reacciones serológicas cruzadas entre algunas especies próximas filogenéticamente. Por eso, con el fin de conocer exactamente la especie de Ehrlichia involucrada en la infección, se puede recurrir a la ayuda de técnicas de diagnóstico molecular.
Neutron background at the Canfranc Underground Laboratory and its contribution to the IGEX-DM dark matter experiment
A quantitative study of the neutron environment in the Canfranc Underground
Laboratory has been performed. The analysis is based on a complete set of
simulations and, particularly, it is focused on the IGEX-DM dark matter
experiment. The simulations are compared to the IGEX-DM low energy data
obtained with different shielding conditions. The results of the study allow us
to conclude, with respect to the IGEX-DM background, that the main neutron
population, coming from radioactivity from the surrounding rock, is practically
eliminated after the implementation of a suitable neutron shielding. The
remaining neutron background (muon-induced neutrons in the shielding and in the
rock) is substantially below the present background level thanks to the muon
veto system. In addition, the present analysis gives us a further insight on
the effect of neutrons in other current and future experiments at the Canfranc
Underground Laboratory. The comparison of simulations with the body of data
available has allowed to set the flux of neutrons from radioactivity of the
Canfranc rock, (3.82 +- 0.44) x 10^{-6} cm^{-2} s^{-1}, as well as the flux of
muon-induced neutrons in the rock, (1.73 +- 0.22(stat) \+- 0.69(syst)) x
10^{-9} cm^{-2} s^{-1}, or the rate of neutron production by muons in the lead
shielding, (4.8 +- 0.6 (stat) +- 1.9 (syst)) x 10^{-9} cm^{-3} s^{-1}.Comment: 17 pages, 8 figures, elsart document class; final version to appear
in Astroparticle Physic
Status and preliminary results of the ANAIS experiment at Canfranc
ANAIS (Annual Modulation with NaI's) is an experiment planned to investigate
seasonal modulation effects in the signal of galactic WIMPs using up to 107 kg
of NaI(Tl) in the Canfranc Underground Laboratory (Spain). A prototype using
one single crystal (10.7 kg) is being developed before the installation of the
complete experiment; the first results presented here show an average
background level of 1.2 counts/(keV kg day) from threshold (Ethr~4 keV) up to
10 keV.Comment: 3 pages, 2 figures, talk delivered at the 7th International Workshop
on Topics in Astroparticle and Underground Physics (TAUP 2001), September
2001, Laboratori Nazionali del Gran Sasso, Italy (to appear in the Conference
Proceedings, Nucl. Phys. B (Proc. Suppl.)
Visitantes florales y potencial polinizador de trichocentrum stramineum orquídea amenazada y endémica de Veracruz
Trichocentrum stramineum es una orquídea endémica del centro de Veracruz y en categoría de riesgo como amenazada según la NOM-059-SEMARNAT-2010 por la reducción poblacional donde habita. Poca información se ha generado de esta orquídea en la literatura especializada y hasta antes del presente trabajo se desconocían sus visitantes florales y su potencial polinizador. De 2014 a 2017, se realizaron observaciones directas e indirectas a las inflorescencias de T. stramineum para registrar los visitantes florales y determinar al potencial polinizador en dos localidades de su distribución geográfica. Se registraron dos especies de visitantes florales en la localidad 1 y tres en la localidad 2. La abeja Centris nitida (Apidae) fue observada efectuando la remoción y deposición de los polinios de T. stramineum en ambas localidades. La abeja Centris tarsata (Apidae) fue observada un par de ocasiones en cada localidad sin que realizara remoción ni deposición de los polinios. La avispa Polybia sp., fue observada en dos ocasiones sólo en la localidad 2 sin llevar a cabo la remoción de polinios. La orquídea T. stramineum presenta un sistema especializado de polinización al depender solo de una especie para la fecundación de las flores. Los registros del polinizador de T. stramineum son los primeros en obtenerse y documentarse para esta orquídea
Site-to-site interdomain communication may mediate different loss-of-function mechanisms in a cancer-associated NQO1 polymorphism
Disease associated genetic variations often cause intracellular enzyme inactivation, dysregulation and instability. However, allosteric communication of mutational effects to distant functional sites leading to loss-of-function remains poorly understood. We characterize here interdomain site-to-site communication by which a common cancer-associated single nucleotide polymorphism (c.C609T/p.P187S) reduces the activity and stability in vivo of NAD(P)H:quinone oxidoreductase 1 (NQO1). NQO1 is a FAD-dependent, two-domain multifunctional stress protein acting as a Phase II enzyme, activating cancer pro-drugs and stabilizing p53 and p73a oncosuppressors. We show that p.P187S causes structural and dynamic changes communicated to functional sites far from the mutated site, affecting the FAD binding site located at the N-terminal domain (NTD) and accelerating proteasomal degradation through dynamic effects on the C-terminal domain (CTD). Structural protein:protein interaction studies reveal that the cancer-associated polymorphism does not abolish the interaction with p73a, indicating that oncosuppressor destabilization largely mirrors the low intracellular stability of p.P187S. In conclusion, we show how a single disease associated amino acid change may allosterically perturb several functional sites in an oligomeric and multidomain protein. These results have important implications for the understanding of loss-of-function genetic diseases and the identification of novel structural hot spots as targets for pharmacological intervention
Ciclo de vida y control de la mariposa asiática de los cítricos, Papilio demoleus (Lepidoptera: Papilionidae), una nueva plaga invasiva en Puerto Rico.
The arrival of the invasive Asian lime swallowtail, Papilio demoleus L., in Puerto Rico has prompted the need for a better understanding of its life cycle, and its control options under local citrus-producing conditions. Our results show that P. demoleus has a life cycle of approximately 30 days. From oviposition, eggs hatch in three days. Larval instar durations are 3, 2, 3, 3, and 5 d for larval stages 1 to 5, respectively. Pupal stage lasts approximately 12 days. Head capsule measurements for instars 1 to 4 are similar in males and females. Last instar females tend to be larger than males. Our data suggest that 12 or more generations are possible under local conditions. Acute stomach toxicity tests on third instar larvae indicate that spinosad and Bacillus thuringiensis subs, kurstaki cause 100% mortality in most concentrations tested. Other insecticides were not effective. Possible advantages of using these products are discussed in light of initiatives to use reduced risk pesticides and biologically-based pesticides.La llegada en el 2006 de la mariposa asiática de los cítricos Papilio demoleus L. a Puerto Rico ha generado interés en conocer detalles sobre su control y sobre su ciclo biológico. Este trabajo estuvo dirigido a describir su ciclo de vida bajo condiciones locales, y a determinar, mediante pruebas de laboratorio, qué plaguicidas biológicos o de riesgo reducido serían efectivos en el manejo de sus poblaciones. Encontramos que en Puerto Rico, la mariposa tuvo un ciclo de vida de alrededor de 30 días. La etapa de huevo dura tres días; los estadios de los estados larvales 1 al 5 son de 3, 2, 3,3 y 5 d, respectivamente; el estado de pupa, 12 días. Las cápsulas cefálicas de las hembras de último estado tienden a ser más grandes que las de los machos. Nuestros datos apuntan hacia la posibilidad de 12 o más generaciones al año de P. demoleus en Puerto Rico. Las pruebas de toxicidad aguda estomacal de terceros estados larvales indican que spinosad y Bacillus thuringiensis subs, kurstaki tienen mortalidades típicas de 100%. Otros plaguicidas probados, como la azadirachtina y una mezcla de piretrinas con rotenona, no fueron tan efectivos. Las posibles ventajas al uso de estos plaguicidas se discute a la luz de iniciativas para fomentar el uso de plaguicidas de "riesgo reducido" en cultivos como los cítricos
Status of IGEX dark matter search at Canfranc Underground Laboratory
One IGEX 76Ge double-beta decay detector is currently operating in the
Canfranc Underground Laboratory in a search for dark matter WIMPs, through the
Ge nuclear recoil produced by the WIMP elastic scattering. In this talk we
report on the on-going efforts to understand and eventually reject the
background at low energy. These efforts have led to the improvement of the
neutron shielding and to partial reduction of the background, but still the
remaining events are not totally identified. A tritium contamination or
muon-induced neutrons are considered as possible sources, simulations and
experimental test being still under progress. According to the success of this
study we comment the prospects of the experiment as well as those of its future
extension, the GEDEON dark matter experiment.Comment: 6 pages, 3 figures, talk given at 4th International Workshop on the
Identification of Dark Matter, York, September 200
Enhanced vulnerability of human proteins towards disease-associated inactivation through divergent evolution
Human proteins are vulnerable towards disease-associated single amino acid replacements affecting protein stability and function. Interestingly, a few studies have shown that consensus amino acids from mammals or vertebrates can enhance protein stability when incorporated into human proteins. Here, we investigate yet unexplored relationships between the high vulnerability of human proteins towards disease-associated inactivation and recent evolutionary site-specific divergence of stabilizing amino acids. Using phylogenetic, structural and experimental analyses, we show that divergence from the consensus amino acids at several sites during mammalian evolution has caused local protein destabilization in two human proteins linked to disease: cancer-associated NQO1 and alanine: glyoxylate aminotransferase, mutated in primary hyperoxaluria type I. We demonstrate that a single consensus mutation (H80R) acts as a disease suppressor on the most common cancer-associated polymorphism in NQO1 (P187S). The H80R mutation reactivates P187S by enhancing FAD binding affinity through local and dynamic stabilization of its binding site. Furthermore, we show how a second suppressor mutation (E247Q) cooperates with H80R in protecting the P187S polymorphism towards inactivation through long-range allosteric communication within the structural ensemble of the protein. Our results support that recent divergence of consensus amino acids may have occurred with neutral effects on many functional and regulatory traits of wild-type human proteins. However, divergence at certain sites may have increased the propensity of some human proteins towards inactivation due to disease-associated mutations and polymorphisms. Consensus mutations also emerge as a potential strategy to identify structural hot-spots in proteins as targets for pharmacological rescue in loss-of-function genetic diseases.Spanish Ministry of Economy and Competitiveness, MINECO (BIO 2015 66426-R to JMSR, CTQ 2015-64445-R to JLN, ‘Factoría Española de Cristalización’, Consolider-Ingenio 2010 to JAG and SAF2015-69796 to ES), Junta de Andalucia (P11-CTS-07187 to ALP) and FEDER fun
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