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1.
Am Heart J ; 242: 115-122, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34480880

RESUMEN

BACKGROUND: The devastating Coronavirus disease (COVID-19) pandemic is associated with a high prothrombotic state. It is unclear if the coagulation abnormalities occur because of the direct effect of SARS-CoV-2 or indirectly by the cytokine storm and endothelial damage or by a combination of mechanisms. There is a clear indication of in-hospital pharmacological thromboprophylaxis for every patient with COVID-19 after bleed risk assessment. However, there is much debate regarding the best dosage regimen, and there is no consensus on the role of extended thromboprophylaxis. DESIGN: This study aims to evaluate the safety and efficacy of rivaroxaban 10 mg once daily for 35 ± 4 days versus no intervention after hospital discharge in COVID-19 patients who were at increased risk for VTE and have received standard parenteral VTE prophylaxis during hospitalization. The composite efficacy endpoint is a combination of symptomatic VTE, VTE-related death, VTE detected by bilateral lower limbs venous duplex scan and computed tomography pulmonary angiogram on day 35 ± 4 posthospital discharge and symptomatic arterial thromboembolism (myocardial infarction, nonhemorrhagic stroke, major adverse limb events, and cardiovascular death) up to day 35 ± 4 posthospital discharge. The key safety outcome is the incidence of major bleeding according to ISTH criteria. SUMMARY: The MICHELLE trial is expected to provide high-quality evidence around the role of extended thromboprophylaxis in COVID-19 and will help guide medical decisions in clinical practice.1.


Asunto(s)
COVID-19/complicaciones , Inhibidores del Factor Xa/administración & dosificación , Rivaroxabán/administración & dosificación , Trombosis/prevención & control , Adulto , Brasil , Esquema de Medicación , Inhibidores del Factor Xa/efectos adversos , Femenino , Hemorragia/inducido químicamente , Humanos , Masculino , Estudios Prospectivos , Embolia Pulmonar/etiología , Embolia Pulmonar/prevención & control , Rivaroxabán/efectos adversos , Tromboembolia/etiología , Tromboembolia/prevención & control , Trombosis/etiología , Trombosis de la Vena/etiología , Trombosis de la Vena/prevención & control
2.
Parasitology ; 146(11): 1379-1386, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31190664

RESUMEN

Survival and infectivity of trypanosomatids rely on cell-surface and secreted glycoconjugates, many of which contain a variable number of galactose residues. Incorporation of galactose to proteins and lipids occurs along the secretory pathway from UDP-galactose (UDP-Gal). Before being used in glycosylation reactions, however, this activated sugar donor must first be transported across the endoplasmic reticulum and Golgi membranes by a specific nucleotide sugar transporter (NST). In this study, we identified an UDP-Gal transporter (named TcNST2 and encoded by the TcCLB.504085.60 gene) from Trypanosoma cruzi, the etiological agent of Chagas disease. TcNST2 was identified by heterologous expression of selected putative nucleotide sugar transporters in a mutant Chinese Hamster Ovary cell line. TcNST2 mRNA levels were detected in all T. cruzi life-cycle forms, with an increase in expression in axenic amastigotes. Confocal microscope analysis indicated that the transporter is specifically localized to the Golgi apparatus. A three-dimensional model of TcNST2 suggested an overall structural conservation as compared with members of the metabolite transporter superfamily and also suggested specific features that could be related to its activity. The identification of this transporter is an important step toward a better understanding of glycoconjugate biosynthesis and the role NSTs play in this process in trypanosomatids.


Asunto(s)
Aparato de Golgi/metabolismo , Proteínas de Transporte de Monosacáridos/metabolismo , Proteínas Protozoarias/genética , Trypanosoma cruzi/genética , Animales , Células CHO , Cricetulus , Proteínas Protozoarias/química , Proteínas Protozoarias/metabolismo , Análisis de Secuencia de Proteína , Trypanosoma cruzi/metabolismo
3.
J Neurosci ; 36(5): 1590-5, 2016 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-26843640

RESUMEN

Alzheimer's disease (AD) is a neurodegenerative disease in which patients experience progressive cognitive decline. A wealth of evidence suggests that this cognitive impairment results from synaptic dysfunction in affected brain regions caused by cleavage of amyloid precursor protein into the pathogenic peptide amyloid-ß (Aß). Specifically, it has been shown that Aß decreases surface AMPARs, dendritic spine density, and synaptic strength, and also alters synaptic plasticity. The precise molecular mechanisms by which this occurs remain unclear. Here we demonstrate a role for ubiquitination in Aß-induced synaptic dysfunction in cultured rat neurons. We find that Aß promotes the ubiquitination of AMPARs, as well as the redistribution and recruitment of Nedd4-1, a HECT E3 ubiquitin ligase we previously demonstrated to target AMPARs for ubiquitination and degradation. Strikingly, we show that Nedd4-1 is required for Aß-induced reductions in surface AMPARs, synaptic strength, and dendritic spine density. Our findings, therefore, indicate an important role for Nedd4-1 and ubiquitin in the synaptic alterations induced by Aß. SIGNIFICANCE STATEMENT: Synaptic changes in Alzheimer's disease (AD) include surface AMPAR loss, which can weaken synapses. In a cell culture model of AD, we found that AMPAR loss correlates with increased AMPAR ubiquitination. In addition, the ubiquitin ligase Nedd4-1, known to ubiquitinate AMPARs, is recruited to synapses in response to Aß. Strikingly, reducing Nedd4-1 levels in this model prevented surface AMPAR loss and synaptic weakening. These findings suggest that, in AD, Nedd4-1 may ubiquitinate AMPARs to promote their internalization and weaken synaptic strength, similar to what occurs in Nedd4-1's established role in homeostatic synaptic scaling. This is the first demonstration of Aß-mediated control of a ubiquitin ligase to regulate surface AMPAR expression.


Asunto(s)
Péptidos beta-Amiloides/farmacología , Complejos de Clasificación Endosomal Requeridos para el Transporte/metabolismo , Sinapsis/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Péptidos beta-Amiloides/fisiología , Animales , Células CHO , Cricetinae , Cricetulus , Potenciales Postsinápticos Excitadores/efectos de los fármacos , Potenciales Postsinápticos Excitadores/fisiología , Femenino , Humanos , Masculino , Ubiquitina-Proteína Ligasas Nedd4 , Ratas , Receptores AMPA/metabolismo , Sinapsis/efectos de los fármacos , Sinapsis/patología
4.
BMC Microbiol ; 15: 269, 2015 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-26589870

RESUMEN

BACKGROUND: Nucleotide sugar transporters (NSTs) play an essential role in translocating nucleotide sugars into the lumen of the endoplasmic reticulum and Golgi apparatus to be used as substrates in glycosylation reactions. This intracellular transport is an essential step in the biosynthesis of glycoconjugates. RESULTS: We have identified a family of 11 putative NSTs in Trypanosoma cruzi, the etiological agent of Chagas' disease. A UDP-N-acetylglucosamine transporter, TcNST1, was identified by a yeast complementation approach. Based on a phylogenetic analysis four candidate genes were selected and used for complementation assays in a Kluyveromyces lactis mutant strain. The transporter is likely expressed in all stages of the parasite life cycle and during differentiation of epimastigotes to infective metacyclics. Immunofluorescence analyses of a GFP-TcNST1 fusion protein indicate that the transporter is localized to the Golgi apparatus. As many NSTs are multisubstrate transporters, we also tested the capacity of TcNST1 to transport GDP-Man. CONCLUSIONS: We have identified a UDP-N-acetylglucosamine transporter in T. cruzi, which is specifically localized to the Golgi apparatus and seems to be expressed, at the mRNA level, throughout the parasite life cycle. Functional studies of TcNST1 will be important to unravel the role of NSTs and specific glycoconjugates in T. cruzi survival and infectivity.


Asunto(s)
Aparato de Golgi/enzimología , Proteínas de Transporte de Membrana/genética , Trypanosoma cruzi/enzimología , Perfilación de la Expresión Génica , Prueba de Complementación Genética , Aparato de Golgi/genética , Kluyveromyces/genética , Kluyveromyces/metabolismo , Estadios del Ciclo de Vida , Proteínas de Transporte de Membrana/metabolismo , Especificidad por Sustrato
5.
Hum Mol Genet ; 21(21): 4587-601, 2012 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-22843498

RESUMEN

Alzheimer's disease (AD) is a neurodegenerative disease pathologically characterized by amyloid plaques and neurofibrillary tangles in the brain. Before these hallmark features appear, signs of axonal transport defects develop, though the initiating events are not clear. Enhanced amyloidogenic processing of amyloid precursor protein (APP) plays an integral role in AD pathogenesis, and previous work suggests that both the Aß region and the C-terminal fragments (CTFs) of APP can cause transport defects. However, it remains unknown if APP processing affects the axonal transport of APP itself, and whether increased APP processing is sufficient to promote axonal dystrophy. We tested the hypothesis that ß-secretase cleavage site mutations of APP alter APP axonal transport directly. We found that the enhanced ß-secretase cleavage reduces the anterograde axonal transport of APP, while inhibited ß-cleavage stimulates APP anterograde axonal transport. Transport behavior of APP after treatment with ß- or γ-secretase inhibitors suggests that the amount of ß-secretase cleaved CTFs (ßCTFs) of APP underlies these transport differences. Consistent with these findings, ßCTFs have reduced anterograde axonal transport compared with full-length, wild-type APP. Finally, a gene-targeted mouse with familial AD (FAD) Swedish mutations to APP, which enhance the ß-cleavage of APP, develops axonal dystrophy in the absence of mutant protein overexpression, amyloid plaque deposition and synaptic degradation. These results suggest that the enhanced ß-secretase processing of APP can directly impair the anterograde axonal transport of APP and are sufficient to lead to axonal defects in vivo.


Asunto(s)
Enfermedad de Alzheimer , Secretasas de la Proteína Precursora del Amiloide , Precursor de Proteína beta-Amiloide , Transporte Axonal/genética , Enfermedad de Alzheimer/enzimología , Enfermedad de Alzheimer/fisiopatología , Secretasas de la Proteína Precursora del Amiloide/antagonistas & inhibidores , Secretasas de la Proteína Precursora del Amiloide/genética , Secretasas de la Proteína Precursora del Amiloide/metabolismo , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Animales , Transporte Axonal/fisiología , Células Cultivadas , Inhibidores Enzimáticos/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Masculino , Ratones , Mutación , Neuronas/metabolismo , Neuronas/patología
6.
Magn Reson Chem ; 51(2): 69-71, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23225640

RESUMEN

Production of alternative fuels, such as biodiesel, from transesterification of vegetable oil driven by heterogeneous catalysts is a promising alternative to fossil diesel. However, achieving a successful substitution for a new renewable fuel depends on several quality parameters. (1)H NMR spectroscopy was used to determine the amount of methyl esters, free glycerin and acid number in the transesterification of soybean oil with methanol in the presence of hydrotalcite-type catalyst to produce biodiesel. Reaction parameters, such as temperature and time, were used to evaluate soybean oil methyl esters rate conversion. Temperatures of 100 to 180 °C and times of 20 to 240 min were tested on a 1 : 12 molar ratio soybean oil/methanol reaction. At 180 °C/240 min conditions, a rate of 94.5 wt% of methyl esters was obtained, where free glycerin and free fatty acids were not detected.


Asunto(s)
Ácidos/análisis , Biocombustibles , Ésteres/análisis , Glicerol/análisis , Glycine max/química , Aceite de Soja/química , Espectroscopía de Resonancia Magnética
7.
Zootaxa ; 5285(2): 389-396, 2023 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-37518698

RESUMEN

A new species of the genus Distatrix Mason, 1981 (Hymenoptera: Braconidae) from Brazil is described and illustrated. This parasitoid was reared from larvae of Argyrotome paraguayaria Schaus, 1927 (Lepidoptera: Geometridae: Palyadini), feeding on Myrsine umbellata Mart. (Primulaceae). This is the first record of parasitism in the genus.

8.
J Neurosci ; 29(18): 5758-67, 2009 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-19420244

RESUMEN

Many neurodegenerative diseases exhibit axonal pathology, transport defects, and aberrant phosphorylation and aggregation of the microtubule binding protein tau. While mutant tau protein in frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP17) causes aberrant microtubule binding and assembly of tau into filaments, the pathways leading to tau-mediated neurotoxicity in Alzheimer's disease and other neurodegenerative disorders in which tau protein is not genetically modified remain unknown. To test the hypothesis that axonal transport defects alone can cause pathological abnormalities in tau protein and neurodegeneration in the absence of mutant tau or amyloid beta deposits, we induced transport defects by deletion of the kinesin light chain 1 (KLC1) subunit of the anterograde motor kinesin-1. We found that upon aging, early selective axonal transport defects in mice lacking the KLC1 protein (KLC1-/-) led to axonopathies with cytoskeletal disorganization and abnormal cargo accumulation. In addition, increased c-jun N-terminal stress kinase activation colocalized with aberrant tau in dystrophic axons. Surprisingly, swollen dystrophic axons exhibited abnormal tau hyperphosphorylation and accumulation. Thus, directly interfering with axonal transport is sufficient to activate stress kinase pathways initiating a biochemical cascade that drives normal tau protein into a pathological state found in a variety of neurodegenerative disorders including Alzheimer's disease.


Asunto(s)
Axones/metabolismo , Proteínas Asociadas a Microtúbulos/metabolismo , Neuronas/citología , Estrés Fisiológico/fisiología , Proteínas tau/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Factores de Edad , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Animales , Animales Recién Nacidos , Axones/ultraestructura , Células Cultivadas , Citoesqueleto/metabolismo , Citoesqueleto/ultraestructura , Proteínas Fluorescentes Verdes/genética , Hipocampo/citología , Proteínas Quinasas JNK Activadas por Mitógenos/metabolismo , Cinesinas , Quimografía/métodos , Proteínas Luminiscentes/genética , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Microscopía Electrónica de Rastreo/métodos , Proteínas Asociadas a Microtúbulos/deficiencia , Proteínas Mitocondriales/genética , Proteínas Mitocondriales/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Proteínas de Neurofilamentos/metabolismo , Neuronas/ultraestructura , Orgánulos/metabolismo , Orgánulos/ultraestructura , Transporte de Proteínas/genética , Estadísticas no Paramétricas , Transfección/métodos , Proteínas tau/genética
9.
Hum Mol Genet ; 17(22): 3474-86, 2008 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-18694898

RESUMEN

Overexpression of amyloid precursor protein (APP), as well as mutations in the APP and presenilin genes, causes rare forms of Alzheimer's disease (AD). These genetic changes have been proposed to cause AD by elevating levels of amyloid-beta peptides (Abeta), which are thought to be neurotoxic. Since overexpression of APP also causes defects in axonal transport, we tested whether defects in axonal transport were the result of Abeta poisoning of the axonal transport machinery. Because directly varying APP levels also alters APP domains in addition to Abeta, we perturbed Abeta generation selectively by combining APP transgenes in Drosophila and mice with presenilin-1 (PS1) transgenes harboring mutations that cause familial AD (FAD). We found that combining FAD mutant PS1 with FAD mutant APP increased Abeta42/Abeta40 ratios and enhanced amyloid deposition as previously reported. Surprisingly, however, this combination suppressed rather than increased APP-induced axonal transport defects in both Drosophila and mice. In addition, neuronal apoptosis induced by expression of FAD mutant human APP in Drosophila was suppressed by co-expressing FAD mutant PS1. We also observed that directly elevating Abeta with fusions to the Familial British and Danish Dementia-related BRI protein did not enhance axonal transport phenotypes in APP transgenic mice. Finally, we observed that perturbing Abeta ratios in the mouse by combining FAD mutant PS1 with FAD mutant APP did not enhance APP-induced behavioral defects. A potential mechanism to explain these findings was suggested by direct analysis of axonal transport in the mouse, which revealed that axonal transport or entry of APP into axons is reduced by FAD mutant PS1. Thus, we suggest that APP-induced axonal defects are not caused by Abeta.


Asunto(s)
Enfermedad de Alzheimer/genética , Péptidos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Transporte Axonal , Axones/metabolismo , Enfermedad de Alzheimer/metabolismo , Precursor de Proteína beta-Amiloide/genética , Análisis de Varianza , Animales , Axones/patología , Conducta Animal , Cerebro/metabolismo , Drosophila , Miedo , Femenino , Humanos , Inmunohistoquímica , Etiquetado Corte-Fin in Situ , Masculino , Ratones , Ratones Transgénicos , Microscopía Electrónica , Presenilinas/genética , Presenilinas/metabolismo , Transgenes
10.
J Hazard Mater ; 366: 34-38, 2019 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-30500696

RESUMEN

New sodium activated vermiculite was used as Cu2+ adsorbent on water simulating the composition of tailing dam of a copper mine in the north region of Brazil. Starting material was vermiculite applied as thermal insulator and adsorbent of Sigma-Aldrich chemical products packs. Characterization was made by X-ray powder diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), thermogravimetric analysis (TGA) and N2 adsorption-desorption (77 K) to raw vermiculite (VERM) and sodium activated vermiculite (NaVERM) and SEM/EDS and FTIR to by-product metal like-xanthate. Activation process was very successful improving the Cu2+ adsorption in acidic medium by vermiculite from 38 to 79%. A bonus of the activation process was a production of metal like-xanthate (MEX) by hydrometallurgical leaching process.

11.
Front Microbiol ; 8: 299, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28352250

RESUMEN

Salmonella spp. is an important zoonotic pathogen related to foodborne diseases. Despite that quinolones/fluoroquinolones are considered a relevant therapeutic strategy against resistant isolates, the increase in antimicrobial resistance is an additional difficulty in controlling bacterial infections caused by Salmonella spp. Thus, the acquisition of resistance to quinolones in Salmonella spp. is worrisome to the scientific community along with the possibility of transmission of resistance through plasmids. This study investigated the prevalence of plasmid-mediated quinolone resistance (PMQR) in Salmonella spp. and its association with fluoroquinolone susceptibility in Brazil. We evaluated 129 isolates, 39 originated from food of animal sources, and 14 from environmental samples and including 9 from animals and 67 from humans, which were referred to the National Reference Laboratory of Enteric Diseases (NRLEB/IOC/RJ) between 2009 and 2013. These samples showed a profile of resistance for the tested quinolones/fluoroquinolones. A total of 33 serotypes were identified; S. Typhimurium (63) was the most prevalent followed by S. Enteritidis (25). The disk diffusion test showed 48.8% resistance to enrofloxacin, 42.6% to ciprofloxacin, 39.53% to ofloxacin, and 30.2% to levofloxacin. According to the broth microdilution test, the resistance percentages were: 96.1% to nalidixic acid, 64.3% to enrofloxacin, 56.6% to ciprofloxacin, 34.1% to ofloxacin, and 30.2% to levofloxacin. Qnr genes were found in 15 isolates (8 qnrS, 6 qnrB, and 1 qnrD), and the aac(6')-Ib gene in 23. The integron gene was detected in 67 isolates with the variable region between ±600 and 1000 bp. The increased detection of PMQR in Salmonella spp. is a serious problem in Public Health and must constantly be monitored. Pulsed-field gel electrophoresis was performed to evaluated clonal profile among the most prevalent serovars resistant to different classes of quinolones. A total of 33 pulsotypes of S. Typhimurium were identified with a low percentage of genetic similarity (≤65%). This result demonstrates the presence of high diversity in the resistant clones evaluated in this study.

12.
Biota Neotrop. (Online, Ed. ingl.) ; 21(4): e20211207, 2021. tab, graf
Artículo en Inglés | LILACS-Express | LILACS | ID: biblio-1345406

RESUMEN

Abstract: The present study reviews the records of occurrences of fish species found in the Mamirauá Sustainable Development Reserve (MSDR). The reserve is located in a large section of the middle Solimões River basin, in its interflow with Japurá River. For the elaboration of the list of fish species occurring in Mamirauá Reserve, we used a database of different studies on fish communities carried out in the area over the last three decades, in addition to the material deposited in the ichthyological collections of three scientific institutions, the National Institute for Amazon Research - INPA, the Mamirauá Sustainable Development Institute - IDSM and the Science and Technology Museum of the Catholic University of Rio Grande do Sul - PUCRS. The ichthyofauna of the MSDR is composed of 541 species, encompassing 45 families and 15 orders. These correspond to 20% of all valid species known for the entire Amazonia so far. As observed in other studies in the Neotropical Region, the more represented orders were Siluriformes (209 species) and Characiformes (185 species), followed by the Gymnotiformes (78 species). The results presented here demonstrate a considerable increase (86%) in the knowledge about the fish diversity found in Mamirauá Reserve, in relation to its first list of fish species, published in the 90's. This increase reflects not only the growth in number of studies on fish diversity in the area, with new surveys, but also the continuous taxonomic work on the collections, and descriptions of twenty-eight new species, with one hundred and ten type series. Further surveys are expected to take place in the Northwestern, more isolated areas of the Reserve, and will allow the identification of new occurrences, and may even unveil new fish species yet to be described to Science..


Resumo: Este estudo apresenta uma revisão dos registros de ocorrências das espécies de peixes encontradas na Reserva de Desenvolvimento Sustentável Mamirauá (RDSM), ampla área localizada na bacia do Médio Solimões, em seu interflúvio com o Rio Japurá. Para a elaboração da lista de peixes que ocorrem na Reserva Mamirauá foram utilizados os bancos de dados de diferentes estudos sobre comunidades de peixes realizados na área ao longo das últimas décadas, além de informações referentes ao material tombado nas coleções ictiológicas de três instituições científicas, o Instituto Nacional de Pesquisas da Amazônia- INPA,o Instituto de Desenvolvimento Sustentável Mamirauá - IDSM e o Museu de Ciências e Tecnologia da Pontifícia Universidade Católica do Rio Grande do Sul - PUCRS. A ictiofauna da RDSM é composta por 541 espécies, incluindo 45 famílias e 15 ordens. Estes valores correspondem a cerca de 20% de todas espécies válidas conhecidas para toda a Amazônia até o momento. Assim como em outros estudos na região Neotropical as ordens que apresentaram as maiores riquezas foram siluriformes (209 espécies) e Characiformes (185 espécies), seguidas de Gymnotiformes (78 espécies). Os resultados apresentados neste trabalho demonstram um aumento considerável (86%) no conhecimento sobre a diversidade de peixes encontrados na Reserva Mamirauá, em relação à primeira lista de peixes da RDSM, publicada na década de 1990. Este aumento reflete não apenas o crescimento no número de estudos sobre a diversidade de peixes na área, com a ocorrência de novos levantamentos, como também a intensificação dos trabalhos taxonômicos de classificação e descrição de vinte oito novas espécies com cento e dez séries tipos. Novos levantamentos deverão ocorrer nas áreas mais isoladas da Reserva, na sua porção noroeste. Estas atividades permitirão a identificação de novas ocorrências, e podem até revelar espécies novas a serem descritas..

13.
Neotrop. ichthyol ; 18(2): e190008, 2020. tab, graf
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-1135387

RESUMEN

A new species of Odontocharacidium is described from the upper Río Orinoco basin, in Venezuela. The new species is distinguished from its only congener, Odontocharacidium aphanes, by the presence of: the antorbital, the parietal branch of the supraorbital laterosensory canal, the postcleithrum 1, the conspicuous bars extending ventrally below the middle portion of the body posteriorly, and two dark round blotches at the tip of the caudal peduncle. With the recognition of an additional species of Odontocharacidium the diagnostic characters of the genus and the variability in the number of maxillary teeth in specimens are discussed.(AU)


Uma nova espécie de Odontocharacidium é descrita para a bacia do alto rio Orinoco, na Venezuela. A nova espécie se distingue da sua única congênere, Odontocharacidium aphanes, pela presença: do antorbital, do ramo parietal do canal látero-sensorial supraorbital, do pós-cleitro 1, de barras conspícuas estendendo-se ventralmente à porção média do corpo e de duas manchas escuras e arredondadas na margem distal do pedúnculo caudal. Com o reconhecimento de uma espécie adicional de Odontocharacidium, são discutidos os caracteres diagnósticos do gênero e a variação no número de dentes maxilares nos espécimes.(AU)


Asunto(s)
Animales , Characiformes , Identidad de Género , Maxilares , Miniaturización
14.
J Comp Neurol ; 457(4): 384-403, 2003 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-12561078

RESUMEN

Neuronal death occurs during normal development and disease and can be regulated by steroid hormones. In the hawkmoth, Manduca sexta, individual accessory planta retractor (APR) motoneurons undergo a segment-specific pattern of programmed cell death (PCD) at pupation that is triggered directly and cell autonomously by the steroid hormone 20-hydroxyecdysone (20E). APRs from abdominal segment six [APR(6)s] die by 48 hours after pupal ecdysis (PE; entry into the pupal stage), whereas APR(4)s survive until adulthood. Cell culture experiments showed previously that 20E acts directly on APRs to trigger PCD, with intrinsic segmental identity determining which APRs die. The APR(6) death pathway includes caspase activation and loss of mitochondrial function. We used transmission electron microscopy to investigate the ultrastructure of APR somata before and during PCD. APR(4)s showed normal ultrastructure at all stages examined, as did APR(6)s until approximately stage PE. During APR(6) death, there was massive accumulation of autophagic bodies and vacuoles, mitochondria became ultracondensed and aggregated into compact clusters, and ribosomes aggregated in large blocks. Nuclear ultrastructure remained normal, without chromatin condensation, until the nuclear envelope fragmented late in the death process. Light microscopic immunocytochemistry showed that dying APR(6)s were TUNEL-positive, which is diagnostic of fragmented DNA. These observations indicate that the steroid-induced, caspase-dependent, cell-autonomous PCD of APR(6)s is autophagic, not apoptotic, and support an early role for mitochondrial alterations during PCD. This system permits the study of neuronal death in response to its bona fide developmental signal, the rise in a steroid hormone.


Asunto(s)
Apoptosis , Autofagia , Ecdisterona/fisiología , Manduca/crecimiento & desarrollo , Metamorfosis Biológica , Neuronas Motoras/ultraestructura , Animales , Inmunohistoquímica , Etiquetado Corte-Fin in Situ , Microscopía Electrónica , Mitocondrias/ultraestructura , Neuronas Motoras/patología
15.
J Food Prot ; 74(12): 2031-8, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22186042

RESUMEN

The goal of this study was to determine the effects of various levels of gamma irradiation on the phenotypic characteristics of 20 strains of Salmonella Enteritidis inoculated separately into specific-pathogen-free shell eggs. Bacterial strains were inoculated into egg yolks and exposed to (60)Co radiation at doses of 0.49 to 5.0 kGy. The eggs were maintained at 25°C and analyzed for the presence of Salmonella on days 1, 2, 4, and 7, and the recovered Salmonella isolates were characterized biochemically. All strains were resistant to doses of 0.49, 0.54, 0.59, 0.8, and 1 kGy; colony counts were ≥10(5) CFU/ml of egg yolk except for one strain, which was detected at 96 h and at 7 days after irradiation at 1 kGy, with a population reduction of 2 log CFU/ml. For the other evaluated doses, 12 strains (60.0%) were resistant at 1.5 kGy and 7 strains (35.0%) were resistant at 3.0 kGy. Among all analyzed strains, 5.0 kGy was more effective for reducing and/or eliminating the inoculated bacteria; only two (10%) strains were resistant to this level of irradiation. Salmonella colony counts were significantly reduced (P < 0.01) with increasing doses from the day 1 to 7 of observation, when microbial growth peaked. Loss of mobility, lactose fermentation, citrate utilization, and hydrogen sulfide production occurred in some strains after irradiation independent of dose and postirradiation storage time. Increases in antibiotic susceptibility also occurred: seven strains became sensitive to ß-lactams, two strains became sensitive to antifolates, and one strain each became sensitive to fluoroquinolone, phenicol, nitrofurans, tetracyclines, and aminoglycosides. The results indicate that up to 5.0 kGy of radiation applied to shell eggs inoculated with Salmonella Enteritidis at 4 log CFU per egg is not sufficient for complete elimination of this pathogen from this food matrix.


Asunto(s)
Huevos/microbiología , Irradiación de Alimentos , Salmonella enteritidis/efectos de la radiación , Animales , Recuento de Colonia Microbiana , Seguridad de Productos para el Consumidor , Relación Dosis-Respuesta en la Radiación , Contaminación de Alimentos/análisis , Contaminación de Alimentos/prevención & control , Microbiología de Alimentos , Rayos gamma , Humanos , Viabilidad Microbiana , Intoxicación Alimentaria por Salmonella/prevención & control , Organismos Libres de Patógenos Específicos
16.
Rev. bras. enferm ; 48(4): 436-43, out.-dez. 1995.
Artículo en Portugués | LILACS, BDENF - Enfermería | ID: lil-207896

RESUMEN

Este trabalho relata uma experiência vivenciada por mim em um hospital-escola de Belo Horizonte, enquanto acadêmica de enfermagem, durante meu primeiro estágio curricular, cuidando de uma adolescente. Tal relato discute a necessidade do preparo da equipe de saúde no trato com o paciente adolescente, assim como para receber o acadêmico em seu primeiro contato com a prática profissional.


Asunto(s)
Humanos , Femenino , Adolescente , Prácticas Clínicas , Brasil , Educación en Enfermería , Práctica Profesional , Relaciones Enfermero-Paciente
17.
Belo Horizonte; s.n; 2000. 157 p.
Tesis en Portugués | LILACS, BDENF - Enfermería | ID: lil-296305

RESUMEN

Esta pesquisa, apoiada na proposta metodológica da fenomenologia, segundo a modalidade do fenômeno situado, revela a percepçäo do auxiliar de enfermagem como sujeito cuidador de pessoas com queimaduras, internadas na Unidade de Tratamento de Queimados do Hospital de Pronto Socorro Joäo XXIII...


Asunto(s)
Humanos , Quemaduras/enfermería , Asistentes de Enfermería/psicología , Atención de Enfermería/psicología , Relaciones Enfermero-Paciente , Unidades de Quemados , Existencialismo
18.
Belo Horizonte; s.n; 1995. 55 p.
Tesis en Portugués | BDENF - Enfermería | ID: biblio-1035786

RESUMEN

Este trabalho, utilizando a metodologia da pesquisa participante, visou a compreensäo do processo de adolescer segundo a própria lógica do adolescente. Foram entrevistados 11 alunos da 6ª série do primeiro grau da Escola Municipal Pedro Pacheco de Souza, em Contagem - Minas Gerais, sendo 4 meninas e 7 meninos, cuja idade variou de 12 a 14 anos. Utilizando uma entrevista aberta, näo diretiva, tendo como fio condutor a questäo: "O que você sabe e o que gostaria de saber sobre o que está acontecendo com você?" e a partir daí com a problematizaçäo das falas dos adolescentes, emergiram 10 categorias. Estas foram devolvidas ao grupo, em reuniöes subsequentes onde o tema a ser debatido era escolhido a priori. Por esta abordagem metodológica foi possível que o grupo, sujeito do processo de discussäo, passasse de um conhecimento ingênuo, errôneo às vezes, para um conhecer-se crítico, reflexivo e criativo.


Asunto(s)
Masculino , Femenino , Humanos , Adolescente , Conducta del Adolescente , Enfermeras y Enfermeros , Enfermeros
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