20 research outputs found
Chemical composition and cytotoxic activity of Lepechinia speciosa (St. Hill) Epling
No full textThe cell viability of Lepechinia speciosa (St. Hill) Epling fractions was measured by cell membrane integrity (lactate dehydrogenase assay) on rat basophilic leukemia cells (RBL-2H3). All fractions and extract tested (100 μg/ml) increased the release of lactate dehydrogenase (LDH), being the ethyl acetate and dichloromethane fractions with LDH release of 94.5% and 91.2%, respectively. As these fractions showed decrease of cell viability, the antiproliferative activity on human breast adenocarcinoma cells (MCF-7) through sulphorhodamine B (SRB) assay was performed with them. The dichloromethane fraction (50 μg/ml) displayed the maximum activity (95% of inhibition) (IC50 = 1.99 ± 0.06 μg/ml). From this fraction was obtained a mixture containing two triterpenes (ursolic and oleanolic acids) and one fatty acid (palmitic acid), which were identified by gas chromatography coupled to mass spectrometry (GC-MS) and had their structures confirmed by 13C NMR. Rosmarinic acid and verbascoside were isolated from the ethyl acetate fraction and had their structures confirmed by 1H NMR.Colegio de Farmacéuticos de la Provincia de Buenos Aire
Do Border Crossings Contribute to Underage Motor-Vehicle Fatalities?
No full textCurrently, Michigan residents can avoid the national drinking age of 21 by crossing into Ontario where the drinking age is 19. This paper explores the impact that border crossings, connecting areas with different minimum legal drinking ages (MLDA), have on motor-vehicle fatalities. We analyze border crossings connecting Michigan to Ontario, as well as to its surrounding states in the period in which Michigan’s MLDA was raised to 21. Using a “differences-in-differences-in-differences” approach we find that the MLDA change did not contribute to increased underage fatalities in border crossing counties.
Do border crossings contribute to underage motor-vehicle fatalities? An analysis of Michigan border crossings
No full textDo border crossings contribute to underage motor-vehicle fatalities? An analysis of Michigan border crossings
No full textCurrently, Michigan residents can avoid the national drinking age of 21 by crossing into Ontario, where the drinking age is 19. This paper explores the impact that border crossings, connecting areas with different minimum legal drinking ages (MLDA), have on motor-vehicle fatalities. We analyse border crossings connecting Michigan to Ontario as well as to its surrounding states in the period in which Michigan's MLDA was raised to 21. Using a `differences-in-differences-in-differences' approach, we find that the MLDA change did not contribute to increased underage fatalities in border-crossing counties.
Exploiting knowledge of immune selection in HIV-1 to detect HIV-specific CD8 T-cell responses
No full textSince HLA-restricted cytotoxic T-cell responses select specific polymorphisms in HIV-1 sequences and HLA diversity is relatively static in human populations, we investigated the use of peptide epitopes based on sites of HLA-associated adaptation in HIV-1 sequences to stimulate and detect T-cell responses ex vivo. These "HLA-optimised" peptides captured more HIV-1 Nef-specific responses compared with overlapping peptides of a single consensus sequence, in interferon-γ enzyme linked immunospot assays. Sites of immune selection can reveal more immunogenic epitopes in HLA-diverse populations and offer insights into the nature of HLA-epitope targeting, which could be applied in vaccine design
La anorexia por actividad desde el punto de vista del análisis experimental del comportamiento
No full textEn este artículo se describe el síndrome de anorexia en humanos. Se analiza la similitud funcional entre el modelo animal de actividad anorexia y patología humana. Además, se describe la teoría de la actividad de la anorexia por Epling y Pierce (1992) para mostrar el desarrollo de esta patología en humanos. También se presentan las teorías más relevantes que han tratado de explicar el origen de la anorexia de actividad. Por último, se resume el análisis experimental de la contribución del comportamiento a la evaluación y el tratamiento de la anorexia de actividad en humanos.In this paper anorexia syndrome in humans is described. Functional similarity between an animal model of activity anorexia and human pathology are analyzed. Moreover, abiobehavioral theory of activity anorexia by Epling and Pierce (1992) is described to showdevelopment of this pathology in humans. The most relevant theories which have tried toexplain the origin of activity anorexia are presented, too. At last, experimental analysis ofbehavior contribution to the evaluation and treatment for activity anorexia in humans areoutlined
Phylogenetische und taxonomische Untersuchungen an der Subtribus Menthinae (Lamiaceae, Nepetoideae, Mentheae) unter besonderer Berücksichtigung des Satureja-Komplexes
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