RESUMO
Reproduction is a critical part of an animal's life history, but one which incurs significant costs to survival and future reproductive potential. These physiological consequences are likely to be influenced by context - for example, if an individual is subject to environmental stressors, physiological and behavioral changes associated with reproduction may be altered. Glucocorticoids, hormones produced as part of the physiological response to stressors, may alter how reproduction affects female physiology and behavior, and therefore the outcomes of reproductive trade-offs. Glucocorticoids prioritize immediate survival over reproduction, for example through changes in immune function, metabolic rate, and foraging, which may reduce energy expenditure or increase energy gain. However, we previously found that female eastern fence lizards (Sceloporus undulatus) experiencing elevated glucocorticoid levels during gestation were nevertheless able to maintain reproductive output and body condition. Here we investigate compensatory mechanisms by which eastern fence lizard females may maintain reproduction under experimental increases in a glucocorticoid, corticosterone (CORT). We found that, although CORT-treated females had similar immune function and behavior, they had reduced metabolic rates 3-5 days post-parturition compared to control females. Given that CORT-treated females spent a similar time basking and had equal food intake compared to control females, we suggest that the reduced metabolic rate is a mechanism by which CORT-treated females maintain their energy balance and reduce the energetic costs of gestation during periods of stress. This study suggests that physiological responses to reproduction may be context-dependent and could act to minimize costs of reproduction in situations where CORT is elevated (such as during periods of environmental stress).
Assuntos
Glucocorticoides , Lagartos , Animais , Corticosterona/metabolismo , Corticosterona/farmacologia , Feminino , Glucocorticoides/metabolismo , Glucocorticoides/farmacologia , Número de Gestações , Lagartos/fisiologia , Parto , GravidezRESUMO
Hemorrhagic transformation of ischemic stroke has devastating consequences, with high mortality and poor functional outcomes. Animal models of ischemic stroke also demonstrate the potential for hemorrhagic transformation, which complicates biochemical characterization, treatment studies, and hinders poststroke functional outcomes in affected subjects. The incidence of hemorrhagic transformation of ischemic stroke in animal model research is not commonly reported. The postmortem brain of such cases presents a complex milieu of biomarkers due to the presence of healthy cells, regions of varying degrees of ischemia, dead and dying cells, dysregulated metabolites, and blood components (especially reactive Fe species released from lysed erythrocytes). To improve the characterization of hemorrhage biomarkers on an ischemic stroke background, we have employed a combination of histology, X-ray fluorescence imaging (XFI), and Fourier transform infrared (FTIR) spectroscopic imaging to assess 122 photothrombotic (ischemic) stroke brains. Rapid freezing preserves brain biomarkers in situ and minimizes metabolic artifacts due to postmortem ischemia. Analysis revealed that 25% of the photothrombotic models had clear signs of hemorrhagic transformation. The XFI and FTIR metabolites provided a quantitative method to differentiate key metabolic regions in these models. Across all hemorrhage cases, it was possible to consistently differentiate otherwise healthy tissue from other metabolically distinct regions, including the ischemic infarct, the ischemic penumbra, blood vessels, sites of hemorrhage, and a region surrounding the hemorrhage core that contained elevated lipid oxidation. Chemical speciation of deposited Fe demonstrates the presence of heme-Fe and accumulation of ferritin.
Assuntos
Isquemia Encefálica , AVC Isquêmico , Acidente Vascular Cerebral , Animais , Biomarcadores , Isquemia Encefálica/complicações , Isquemia Encefálica/diagnóstico por imagem , Hemorragia/complicações , Humanos , AVC Isquêmico/diagnóstico por imagem , Imagem Multimodal , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/epidemiologiaRESUMO
BACKGROUND: In recent years, serious adverse effects to children from exposure to single-use detergents sacs (SUDS) have been recognized. While most exposures result in minor symptoms, there have been serious outcomes. This study aims to classify which types of serious outcomes follow SUDS exposures, and to assess, if possible, differences in toxicity between various SUDS products. METHODS: An observational case series with data collected retrospectively was performed for cases of SUDS exposures reported to a statewide poison system's records database from 1 January 2012 to 31 March 2013. Cases were identified and analyzed for clinical details and trends. A statewide database was queried for cases involving the American Association of Poison Control Centers (AAPCC) product-specific codes for SUDS products using following search terms: laundry pods, the AAPCC product-specific codes for Tide Pods, Purex Ultrapacks, ALL Mighty Pacs, and a unique agent code (AAPCC ID: 6903138; Generic: 077900) created by AAPCC to track SUDS exposures. RESULTS: A total of 804 cases of exposures to SUDS were identified, the majority of which were exploratory ingestions in young children with a median age of 2 years. Serious adverse effects resulted from 65 (9%) exposures and 27 (3%) exposures resulted in admission to hospital. Binary logistic regression demonstrated that the presence of central nervous system (CNS) or respiratory system effects were associated with more severe outcomes, with a model accuracy of 96.4%. There were significant differences in morbidity among the three most common brand-name products: when compared with Tide Pods, odds ratios (OR) and 95% confidence intervals (CI) for severe outcome and admission rate were significantly greater following Purex Ultrapack exposures (severity OR 5.1 [CI: 2.13-12.23]; admission OR 10.36 [CI: 3.23-33.22]) and ALL Mighty Pac exposures (severity OR 11.22 [CI: 4.78-28.36]; admission OR 15.20 [CI: 5.01-46.12]). CONCLUSIONS: Serious complications from exposure to SUDS occur in a small number of exposures for unclear reasons. Respiratory and CNS effects are associated with more severe outcomes. Some brand-name products are associated with a relatively higher risk of severe adverse effects and rates of admission.
Assuntos
Detergentes/efeitos adversos , Centros de Controle de Intoxicações , Adolescente , Criança , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Modelos Logísticos , Estudos Retrospectivos , Estados UnidosRESUMO
Quantitative absorption measurements in CH(2)F(2) in the vicinity of 9-microm P-branch CO(2) laser lines made using a 300-MHz tunable-waveguide CO(2) laser gave rise to the observation of six new far-infrared laser lines. The strength of two of these lines is comparable with that of the strongest transitions reported so far in CH(2)F(2). Four of the lines have been assigned to molecular transitions.
RESUMO
The Fourier-transform method is often used to evaluate fringe patterns. The fundamental limitations of its accuracy are examined. Special filter functions leading to an improved spatial definition and a fringe-extrapolation algorithm that reduces the errors at the border of the pattern are presented. Numerical simulations predict an accuracy of the phase evaluation of less than 6 mrad under certain conditions. We investigated the reproducibility by experiments with a Michelson interferometer. Deviations of approximately 10 mrad were found. In a second test a Ronchi ruling was imaged, and a well-defined phase change was introduced. We deduce an accuracy of less than 5 mrad rms.