257 research outputs found

    SP-Sephadex equilibrium chromatography of bradykinin and related peptides: Application to trypsin-treated human plasma

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    An analytical method is deseribed for the separation of bradykinin, Lys-bradykinin, and Met-Lys-bradykinin by equilibrium chromatography on SP-Sephadex C-25 eluted in 0.02 Tris-HCl buffer, pH 8.10, 0.12 NaCl. A second elution buffer, 0.02 Tris-HCl buffer, pH 7.70, 0.06 NaCl, serves as a second parameter for the identification of bradykinin and also separates the hormone from plasma bradykinin-potentiating peptides. Ten to one-hundred nanomoles of each peptide can be recovered in high yields, identified by elution position, and measured by bioassay with the isolated guinea pig ileum. The identification of bradykinin as the peptide released by trypsin acting on acid-denatured plasma is documented as an illustration of the method

    Influence Networks in the Foreign Exchange Market

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    Random walker in a temporally deforming higher-order potential forces observed in financial crisis

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    Basic peculiarities of market price fluctuations are known to be well described by a recently developed random walk model in a temporally deforming quadric potential force whose center is given by a moving average of past price traces [Physica A 370, pp91-97, 2006]. By analyzing high-frequency financial time series of exceptional events such as bubbles and crashes, we confirm the appearance of nonlinear potential force in the markets. We show statistical significance of its existence by applying the information criterion. This new time series analysis is expected to be applied widely for detecting a non-stationary symptom in random phenomena.Comment: 5 pages, 13 figure

    Histone deacetylase 2–mediated deacetylation of the glucocorticoid receptor enables NF-κB suppression

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    Glucocorticoids are the most effective antiinflammatory agents for the treatment of chronic inflammatory diseases even though some diseases, such as chronic obstructive pulmonary disease (COPD), are relatively glucocorticoid insensitive. However, the molecular mechanism of this glucocorticoid insensitivity remains uncertain. We show that a defect of glucocorticoid receptor (GR) deacetylation caused by impaired histone deacetylase (HDAC) 2 induces glucocorticoid insensitivity toward nuclear factor (NF)-κB–mediated gene expression. Specific knockdown of HDAC2 by RNA interference resulted in reduced sensitivity to dexamethasone suppression of interleukin 1β–induced granulocyte/macrophage colony-stimulating factor production. Loss of HDAC2 did not reduce GR nuclear translocation, GR binding to glucocorticoid response element (GRE) on DNA, or GR-induced DNA or gene induction but inhibited the association between GR and NF-κB. GR becomes acetylated after ligand binding, and HDAC2-mediated GR deacetylation enables GR binding to the NF-κB complex. Site-directed mutagenesis of K494 and K495 reduced GR acetylation, and the ability to repress NF-κB–dependent gene expression becomes insensitive to histone deacetylase inhibition. In conclusion, we show that overexpression of HDAC2 in glucocorticoid-insensitive alveolar macrophages from patients with COPD is able to restore glucocorticoid sensitivity. Thus, reduction of HDAC2 plays a critical role in glucocorticoid insensitivity in repressing NF-κB–mediated, but not GRE-mediated, gene expression

    Antioxidant dietary deficiency induces caspase activation in chick skeletal muscle cells

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    Apoptosis and necrosis are two distinct forms of cell death that can occur in response to different agents and stress conditions. In order to verify if the oxidative stress induced by dietary selenium and vitamin E deficiencies can lead muscle cells to apoptosis, one-day-old chicks were reared using diets differing in their vitamin E (0 or 10 IU/kg) and selenium (0 or 0.15 ppm) supplementation. Chick skeletal muscle tissue was obtained from 28-day-old animals and used to verify apoptosis occurrence based on caspase activity detection and DNA fragmentation. Antioxidant deficiency significantly increased caspase-like activity assessed by the hydrolysis of fluorogenic peptide substrates (Abz-peptidyl-EDDnp) at lambdaexc = 320 nm and lambdaem = 420 nm. Proteolytic activation was not accompanied by typical internucleosomal DNA fragmentation detected by field inversion gel electrophoresis. Although the general caspase inhibitor N-benzyloxycarbonyl-Val-Ala-Asp(O-Me) fluoromethyl ketone (Z-VAD-fmk) (0 to 80 muM) did not block caspase-like activity when preincubated for 30 min with muscle homogenates, the hydrolyzed substrates presented the same cleavage profile in HPLC (at the aspartic acid residue) when incubated with the purified recombinant enzyme caspase-3. These data indicate that oxidative stress causes caspase-like activation in muscle cells and suggest that cell death associated with exudative diathesis (dietary deficiency of selenium and vitamin E) can follow the apoptotic pathway.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de BioquímicaUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de BiofísicaUniversidade de São Paulo Faculdade de Zootecnia e Engenharia de Alimentos Departamento de CiênciasUNIFESP, EPM, Depto. de BioquímicaUNIFESP, EPM, Depto. de BiofísicaSciEL

    Delineating Genetic Alterations for Tumor Progression in the MCF10A Series of Breast Cancer Cell Lines

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    To gain insight into the role of genomic alterations in breast cancer progression, we conducted a comprehensive genetic characterization of a series of four cell lines derived from MCF10A. MCF10A is an immortalized mammary epithelial cell line (MEC); MCF10AT is a premalignant cell line generated from MCF10A by transformation with an activated HRAS gene; MCF10CA1h and MCF10CA1a, both derived from MCF10AT xenografts, form well-differentiated and poorly-differentiated malignant tumors in the xenograft models, respectively. We analyzed DNA copy number variation using the Affymetrix 500 K SNP arrays with the goal of identifying gene-specific amplification and deletion events. In addition to a previously noted deletion in the CDKN2A locus, our studies identified MYC amplification in all four cell lines. Additionally, we found intragenic deletions in several genes, including LRP1B in MCF10CA1h and MCF10CA1a, FHIT and CDH13 in MCF10CA1h, and RUNX1 in MCF10CA1a. We confirmed the deletion of RUNX1 in MCF10CA1a by DNA and RNA analyses, as well as the absence of the RUNX1 protein in that cell line. Furthermore, we found that RUNX1 expression was reduced in high-grade primary breast tumors compared to low/mid-grade tumors. Mutational analysis identified an activating PIK3CA mutation, H1047R, in MCF10CA1h and MCF10CA1a, which correlates with an increase of AKT1 phosphorylation at Ser473 and Thr308. Furthermore, we showed increased expression levels for genes located in the genomic regions with copy number gain. Thus, our genetic analyses have uncovered sequential molecular events that delineate breast tumor progression. These events include CDKN2A deletion and MYC amplification in immortalization, HRAS activation in transformation, PIK3CA activation in the formation of malignant tumors, and RUNX1 deletion associated with poorly-differentiated malignant tumors

    Estudo dos doenças sexualmente transmissíveis no município de Londrina, Paraná, Brasil: III. A prevalência da gonorréia em 1976-1977

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    This study of the prevalence of gonorrhea in Londrina, Paraná shows - from data obtained from four of the city's major laboratories - that 1993 out of every 100,000 people are infected with gonorrhea. Analysis of public health services found them inadequate for control of this and other venereal diseases.Estudou-se o problema das doenças sexualmente transmissíveis a nível local, a partir de informações colhidas em 4 grandes laboratórios da cidade. Estimou-se que a prevalência de gonorréia, para um ano compreendido entre 1976 e 1977, foi de 1993,0 casos por 100.000 habitantes, valores esses dezenas de vezes maior àqueles apresentados pelas estatísticas oficiais. Analisando os serviços existentes, concluiu-se que no município não existem condições atuais para um adequado controle da doença

    Sorotipos, "mating type" e ploidia de amostras de C. neoformans isoladas de pacientes no Brasil

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    Serotype, mating type and ploidy of 84 strains of Cryptococcus neoformans isolated from 61 AIDS and 23 non-AIDS patients admitted in a tertiary teaching hospital in São Paulo, Brazil were examined. Among 61 strains isolated from AIDS patients, 60 strains were var. grubii (serotype A). Only one strain was var. gattii (serotype B). No var. neoformans (serotype D) was found. Among 23 strains isolated from non-AIDS patients, 15 were var. grubii (serotype A) and the remaining 8 were var. gattii, all of which were serotype B. Seventy-three of the 75 serotype A strains were the heterothallic alpha type (MATalpha) and the remaining 2 were untypable (asexual). Most of the MATalpha strains (69/73) were haploid and the remaining 4 strains were diploid. Similarly, both of the 2 asexual strains among the 75 serotype A strains were haploid. There were no alpha-mating type (MATalpha) strains among the 84 isolates. All of the 8 var. gattii strains were serotype B and haploid. Among a total of 84 strains tested, neither serotype AD nor serotype D were found. Neither triploid nor tetraploid were found. These results suggest that the serological, sexual and ploidy characteristics in C. neoformans strains isolated from AIDS patients in São Paulo were rather simple, whereas strains isolated from non-AIDS patients presented serotype A and B with predominance of serotype A.Foram estudados os sorotipos, "mating type" e ploidia de 84 amostras de C. neoformans isoladas de 61 pacientes com AIDS e 23 não-AIDS em São Paulo. Das amostras isoladas de pacientes com AIDS, 60 foram identificadas como var. grubii (sorotipo A) e 1 como var. gattii (sorotipo B). Não houve isolamento do sorotipo D. Entre as amostras isoladas, de pacientes não-AIDS, 15 foram de var. grubii (sorotipo A) e as 8 restantes de var. gattii, todos do sorotipo B. Setenta e três dos 75 sorotipos A foram identificadas como cepas heterotálicas do fenótipo alfa (MATalfa) e as 2 remanescentes não-tipáveis (assexuada), eram haplóides. A maioria das cepas MATalfa (69/73) era haplóide sendo 4 diplóide. Não houve o isolamento de fenótipo a (MATa) entre as 84 cepas analisadas. Todas as 11 amostras de var. gattii eram do sorotipo B e haplóides. Não foram observados os sorotipos AD e C, nem células triplóides ou tetraplóides entre as 84 amostras estudadas. Os resultados sugerem, que as características sorológicas, sexuais e de ploidia de C. neoformans, isoladas de pacientes com AIDS em São Paulo, são particularmente simples, a maioria do sorotipo A, enquanto que nos pacientes não-AIDS foram observados tanto os sorotipos A quanto o B
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