44 research outputs found

    Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

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    In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

    Effect of metyrapone on the pituitary-adrenal axis in depression: relation to dexamethasone suppressor status.

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    It has been suggested that the well-documented hypercortisolaemia found in a proportion of patients with severe depression occurs either in response to excessive secretion of corticotrophin-releasing hormone-41 (CRH-41) from the hypothalamus, or as a consequence of up-regulation of pituitary CRH-41 receptors. The attenuation of the normal ACTH response to CRH-41 in these subjects is thought to result from inhibition of corticotrophin secretion by elevated cortisol levels. We tested these hypotheses by examining ACTH responses to metyrapone, an 11 beta-hydroxylase inhibitor which blocks the formation of cortisol, followed by CRH-41 in 15 severely depressed in-patients diagnosed according to DSM-IIIR criteria. Patients were assigned to two groups according to their response to overnight administration of 1 mg dexamethasone: suppressors (8) and nonsuppressors (7). A third group consisted of 6 healthy matched controls. Metyrapone 750 mg was given 4-hourly for 24 h and samples were taken for cortisol and ACTH. Six of the original 15 patients (3 from each group) were given a bolus dose of 100 micrograms human CRH-41 intravenously after 24 h of metyrapone, and ACTH levels were measured over 2 h. Falls in circulating cortisol in response to metyrapone were similar in all three groups. However, we found exaggerated rises in ACTH amongst the nonsuppressors, as compared to the suppressors and the control group, after metyrapone.(ABSTRACT TRUNCATED AT 250 WORDS

    Infecção urinária em menores de 15 anos: etiologia e perfil de sensibilidade antimicrobiana em hospital geral de pediatria Urinary tract infection in children under 15 years: etiology and antimicrobial susceptibility in a children's hospital

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    OBJETIVO: Descrever a prevalência dos principais agentes etiológicos de infecção urinária comunitária em crianças menores de 15 anos e analisar o perfil de sensibilidade antimicrobiana do principal agente, Escherichia coli. MÉTODOS: Estudo retrospectivo conduzido a partir de uroculturas com crescimento de agente único, com unidades formadoras de colônia maior ou igual a 10(5)/mL. A população selecionada foi atendida no Pronto Atendimento de Pediatria do Hospital Universitário da Universidade de São Paulo entre janeiro de 2006 e dezembro de 2007. Para analisar o perfil de sensibilidade de E. coli, foram excluídos casos com infecção urinária de repetição e/ou portadores de uropatias. RESULTADOS: Dos 176 casos de infecção urinária, 133 (76%) ocorreram no sexo feminino e 43 (24%) no masculino. A faixa etária de maior prevalência das infecções urinárias foi a de menores de dois anos, com 84 casos (48%). Escherichia coli foi o principal agente isolado (122 culturas - 69% do total). Foram encontrados altos índices de sensibilidade antimicrobiana de E. coli às cefalosporinas de segunda e terceira geração (cefuroxima e ceftriaxona, 100%), aos aminoglicosídeos (amicacina, 100%; gentamicina, 96,4%), ao ácido nalidíxico (97,3%), à nitrofurantoina (98,2%) e às quinolonas (ciprofloxacina e norfloxacina, 98,2%); sensibilidade moderada à cefalosporina de primeira geração (cefalotina, 78,4%); baixa sensibilidade à ampicilina (38,7%) e ao sufametoxazol-trimetoprim (55%). CONCLUSÕES: E. coli continua sendo a bactéria mais prevalente das infecções urinárias comunitárias. Conhecendo a baixa sensibilidade in vitro dessa bactéria à sulfametoxazol-trimetoprim e à ampicilina, recomenda-se que tais drogas não sejam eleitas para a terapêutica inicial.<br>OBJECTIVE: To describe the prevalence of the most frequent etiological agents of community acquired urinary tract infection in children under the age of 15 years, as well as to analyse the antimicrobial susceptibility patterns of the most prevalent pathogen, Escherichia coli. METHODS: Retrospective study conducted from urine cultures of a single bacterial species, at a concentration > 10(5) colonies forming units/mL. The children included in the study were treated in the Pediatric Emergency Care Unit of the University Hospital of the University of Sao Paulo from January, 2006 to December, 2007. In order to analyze Escherichia coli antimicrobial susceptibility patterns, cases with recurrent urinary tract infection and/or carriers of uropathy were excluded. RESULTS: Among 176 urinary tract infection patients, 133 (76%) were females. Children less than two years old presented the highest prevalence of urinary tract infection (84 cases; 48%). E. coli was the main agent (122 cultures - 69% of the total). There were high rates of E. coli antimicrobial susceptibility to second and third-generation cephalosporins (cefuroxime and ceftriaxone, 100%), aminoglycosides (amikacin, 100%, gentamicin, 96.4%), nalidixic acid (97.3%), nitrofurantoin (98.2%) and quinolones (ciprofloxacin and norfloxacin, 98.2%); moderate susceptibility to first-generation cephalosporin (cephalothin, 78.4%); low susceptibility to ampicillin (38.7%) and sufamethoxazole-trimethoprim (55%). CONCLUSIONS: E. coli remains the most prevalent bacterial pathogen of community acquired urinary tract infection. Given the low in vitro susceptibility of these bacteria to sulfamethoxazole-trimethoprim and ampicillin, these drugs should not be elected as the initial choice for treatment

    Macrofossil floras of the Latady Basin, Antarctic Peninsula

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    New collections of plant material from the Merrick and Sweeney Mountains provide further evidence of Jurassic floral diversity in the Antarctic Peninsula. Eighteen taxa are recognised, including sphenophytes (Equisetum), ferns (Cladophlebis, Sphenopteris, Coniopteris), Bennettitales (Otozamites, Zamites, Ptilophyllum, Dicytozamites, Williamsonia), conifers (Pagiophyllum, Brachyphyllum, Elatocladus), and other seed plants (Taeniopteris, Archangelskya, Pachypteris). Many of these species occur in floras from the Botany Bay Group (Early–Middle Jurassic), and other Late Jurassic to Early Cretaceous sites across the Antarctic Peninsula. The plant material from the Latady Basin occurs in two main associations with distinct floristic compositions that reflect local environmental and taphonomic conditions. The richest localities occur in the deltaic settings, where paleosoil and leaf litter layers are preserved. In contrast, relatively little plant material is found in the wholly marine units such as those from the Hauberg Mountains

    The diversity of Australian Mesozoic bennettitopsid reproductive organs

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    Several dispersed reproductive organs of bennettitopsid gymnosperms are described and illustrated from Triassic to Cretaceous strata of Australia: Williamsonia eskensis sp. nov. (Middle Triassic), Williamsonia ipsvicensis sp. nov. (Upper Triassic), Williamsonia durikaiensis sp. nov. (Lower Jurassic), Williamsonia sp. (Lower Jurassic), Williamsonia rugosa sp. nov. (Middle Jurassic), Williamsonia gracilis sp. nov. (Lower Cretaceous), Cycadolepis ferrugineus sp. nov. (Lower Jurassic), Cycadolepis sp. (Lower Cretaceous), and Fredlindia moretonensis Shirley 1898 comb. nov. (Upper Triassic). Among these, W. eskensis appears to represent the oldest bennettitalean reproductive structure yet identified. Although global floras expressed less provincialism during the Mesozoic and many genera are cosmopolitan, Australian bennettopsid species appear to have been endemic based on the morphological characters of the reproductive structures. Bennettopsids have a stratigraphic range of around 210 million years in Australia and are widely and abundantly represented by leaf fossils, but only around 20 specimens of reproductive structures, of which half are attributed to Fredlindia, have been recovered from that continent’s geological archive. The extremely low representation of reproductive organs vis-à-vis foliage is interpreted to reflect a combination of physical disintegration of the seed-bearing units while attached to the host axis and, potentially, extensive vegetative reproduction in bennettopsids growing at high southern latitudes during the Mesozoic.Other funding from:National Science Foundation (project #1636625)German Research Council (DFG KR2125/3)Friends of the Swedish Museum of Natural History (Riksmusei Vänner, Stockholm)SYNTHESYS (AT-TAF 467)</p

    Imaging of Jurassic fossils from the Talbragar Fish Bed using fluorescence, photoluminescence, and elemental and mineralogical mapping

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    <div><p>The Talbragar Fish Bed is one of Australia’s most important Jurassic deposits for freshwater fishes, land plants and aquatic and terrestrial insects. The site has yielded many well preserved fossils, which has led to the formal description of numerous new species and higher taxa. The excellent preservation of many fossils has allowed detailed anatomical studies, e.g. of the early teleost fish <i>Cavenderichthys talbragarensis</i> (Woodward, 1895). Here we report on the fluorescent characteristics and mineral composition of a range of Talbragar fossils. Most specimens fluoresce under ultraviolet, blue and green light. Elemental and mineralogical analyses revealed that the Talbragar fossils consist predominantly of quartz (SiO<sub>2</sub>), a mineral that is likely to account for the observed fluorescence, with trace kaolinite (Al<sub>2</sub>Si<sub>2</sub>O<sub>5</sub>(OH)<sub>4</sub>) in some of the fish fossils. Rock matrices are predominantly composed of quartz and goethite (FeO(OH)). Closer inspection of a plant leaf (<i>Pentoxylon australicum</i> White, 1981) establishes fluorescence as a useful tool for the visualisation of anatomical details that are difficult to see under normal light conditions.</p></div
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