Navegando por Palavras-chave "zinc"

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    The C-terminus of murine S100A9 inhibits spreading and phagocytic activity of adherent peritoneal cells
    (Birkhauser Verlag Ag, 2005-05-01) Pagano, R. L.; Sampaio, S. C.; Juliano, L.; Juliano, M. A.; Giorgi, R.; Butantan Inst; Universidade Federal de São Paulo (UNIFESP)
    Objective and design: in the present study, the effect of a synthetic peptide (H-92-G(102)) identical to the C-terminus of murine S100A9 (mS100A9p) was investigated on adherent peritoneal cell function.Materials and methods: for in vitro assays, peritoneal cells were obtained from the abdominal cavity of mice and incubated, with the different concentrations of mS100A9p, for 1 h, and then their spreading and phagocytosis activities were evaluated. for ex-vivo assays, cells obtained from animals treated for 1 h with the peptide were submitted to the mannose-receptor phagocytosis assay. Shorter homologue peptides to the C-terminus of mS100A9p were also evaluated on in vitro phagocytosis assays of Candida albicans particles.Results: mS100A9p reduced both the spreading index and phagocytic activity, in vitro and ex-vivo, independent of the receptor evaluated. the homologue peptide corresponding to the H-92-E-97 region of mS100A9p, the zinc-binding motif, was responsible for such an effect.Conclusion: These results suggest a modulator effect of the C-terminus of S100A9 protein on the function of adherent peritoneal cells.
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    Copper and zinc intake and serum levels in patients with juvenile rheumatoid arthritis
    (Nature Publishing Group, 2003-05-01) Amancio, Olga Maria Silverio [UNIFESP]; Chaud, Daniela Maria Alves [UNIFESP]; Yanaguibashi, Gianni [UNIFESP]; Hilário, Maria Odete Esteves [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Objective: To evaluate the copper and zinc intake and serum levels in patients with juvenile rheumatoid arthritis (JRA), considering the pauci and polyarticular types, the disease activity and duration, the number of inflamed joints and the use of corticosteroids therapy.Design: Cross-sectional study with control group.Setting: Outpatients of the pediatric rheumatology public health clinic, of the Universidade Federal de São Paulo/Escola Paulista de Medicina, Brazil.Subjects: Forty-one patients with JRA were evaluated and 23 patients' brothers, as a control group. Interventions: Copper and zinc intake evaluation by Food Register method. Copper and zinc serum levels by atomic absorption spectrophotometry.Results: the disease activity did not determine difference in copper (P = 0.624) and zinc (P = 0.705) intake, being predominantly below the Recommended Dietary Allowances. the serum copper in relation to control was statistically greater (P = 0.018), showing that the number of inflamed joints is statistically significantly related with its variation (P = 0.001). the serum zinc was not different either in relation to control (P = 0.940) or to the disease characteristics.Conclusions: the evaluation of copper intake seems to be of fundamental importance. It may influence the efficiency of the organic serum response. More research is needed to indicate, with security, adequate zinc intake.
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    Effect of end-stage renal disease and diabetes on zinc and copper status
    (Humana Press Inc, 2006-07-01) Batista, Maria Nazare; Cuppari, Lilian; Campos Pedrosa, Lucia de Fatima; Almeida, Maria Das Gracas; De Almeida, Jose Bruno; Queiroz de Medeiros, Anna Cecilia; Canziani, Maria Eugienia F.; Universidade Federal de São Paulo (UNIFESP); Univ Fed Rio Grande Norte
    The aim of this study was to compare the nutritional status of zinc and copper in patients with and without diabetes submitted to chronic hemodialysis. Thirty-three patients with type 2 diabetes (DM group), 30 nondiabetic patients (NDM group), and 20 healthy individuals (control group) were studied. Plasma, erythrocyte, and urinary zinc and plasma copper were obtained from atomic absorption spectrophotometry and ceruloplasmin by immunonephelometry. the anthropometric parameters were similar among the groups. Plasma zinc was lower and erythrocyte zinc was higher in the DM and NDM groups in relation to the control group. No difference in urinary zinc was observed comparing the groups. Plasma copper was higher in the DM group when compared to the NDM and control groups. Ceruloplasmin was similar in the three groups. Serum urea was a positive independent determinant of plasma zinc concentrations. the determinants of erythrocyte zinc were MAMC midarm muscle circumference and Kt/V dialysis adequacy. the determinants of plasma copper concentration were serum creatinine and serum glucose. the results of this study demonstrate an alteration in the distribution of zinc in patients with chronic kidney disease (CKD) independently of the presence of DM. Also, the status of copper seems not to be influenced by CKD, but only by the metabolic derangements associated with diabetes.
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    Effects of zinc on cell-mediated immunity in chronic hemodialysis patients
    (Humana Press Inc, 2004-06-01) Ribeiro, RCJ; Sales, VSF; Neves, FDR; Drabe, S.; Brandao-Neto, J.; Univ Fed Rio Grande Norte; Universidade de Brasília (UnB); Universidade Federal de São Paulo (UNIFESP)
    Thirteen healthy subjects and 20 hemodialysis patients were studied to observe the delayed hypersensitivity skin tests (DHSTs) and phytohemagglutinin (PHA)-stimulating lymphocyte blastogenesis. Significant differences were observed between the groups. Controls had a higher proportion of positive skin reaction than hemodialysis patients in relation to Escherichia coli (p<0.01) and tuberculin (PPD) (p<0.05). Regarding lymphocyte blastogenesis stimulated by phytohemagglutinin (PHA), cell proliferation was more accentuated in controls than hemodialysis patients (p<0.05). On the other hand, serum zinc was elevated in controls (78 +/- 8 mug/dL) in comparison to hemodialysis patients (71 +/- 33 mug/dL) (p<0.05). of the 20 hemodialysis patients, 8 patients were maintained on long-term hemodialysis before and after zinc therapy, with the aim of studying DHST and PHA-stimulating lymphocyte blastogenesis. There was a significant improvement of DHST response to E. coli antigen after 100 d of zinc treatment (p<0.01), and with the discontinuation of therapy, the DHST responses decreased back to the initial values (p<0.05). Zinc administration also increased the lymphocyte proliferation induced by PHA from 31386 +/- 3974 to 42480 +/- 5242 cpm (mean +/-SD) (p<0.05). These results indicated that zinc therapy improved in vivo and in vitro DHST and lymphocyte function of hemodialysis patients and that its discontinuation suppressed all of the benefits observed.
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    Eficácia da suplementação oral de zinco no tratamento do zumbido: revisão sistemática de ensaios clínicos randomizados pela metodologia da colaboração cochrane
    (Universidade Federal de São Paulo (UNIFESP), 2013-11-27) Person, Osmar Clayton [UNIFESP]; Torloni, Maria Regina Torloni [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Introduction: Zinc is an important oligoelement involved in several physiological functions including central neurotransmission. Abnormal zinc physiology has been associated with the onset of tinnitus and systematic administration of zinc has been tested as an alternative treatment for this disorder by several investigators over the last decades. Objectives: To assess the effectiveness and safety of oral zinc supplementation in the treatment of tinnitus. Methods: We conducted systematic searches for randomised controlled trials, in August 2013, that compared zinc supplementation versus placebo for tinnitus in adults (18 years and over). Four electronic databases were searched for relevant studies (Cochrane Central Register of Controlled Trials – CENTRAL- from inception to 2013, PUBMED (1966-2013), EMBASE (1974-2013) and LILACS (1982-2013). There were no language, publication year or publication status restrictions. Two researches independently extracted data and assessed the quality of the studies. Results: Three trials involving a total of 276 patients were included. The quality of these trials in general was moderate. All studies assessed the effect of zinc supplementation on improvement of tinnitus. Tinnitus loudness was evaluated only in two studies (228 patients). There is difference between the groups treated with zinc and placebo (RR=2,32; CI 95% 1,17,4,60) for improvement of tinnitus. For tinnitus loudness, there is no differences between the groups treated and control (MD-0,77; CI 95% -6,35,4,81). Conclusions: Statistical analyses indicate improvement of tinnitus in patients treated with zinc. However, due to small number of trials, the evidence is limited and should be taken with caution. For tinnitus loudness there is no evidence of improvement with zinc supplementation. 8
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    Ferro, cobre e zinco em adolescentes no estirão pubertário
    (Sociedade Brasileira de Pediatria, 2002-01-01) Urbano, Marcia R.d. [UNIFESP]; Vitalle, Maria Sylvia de Souza [UNIFESP]; Juliano, Yara; Amancio, Olga Maria Silverio [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Universidade de Santo Amaro Faculdade de Medicina
    Objective: to examine iron, copper and zinc nutritional status and their correlation with Body Mass Index (BMI), serum and dietetic levels in adolescents during the pubertal growth spurt. Methods: a descriptive cross-sectional study involving a sample of 47 adolescents out of 360 patients (19 boys, whose ages ranged from 12.3 to 16 years and 28 girls, whose ages ranged from 11.1 to 13.6 years), who were seen at a clinic for adolescents from March to December 1999. The variables analyzed were: Diet (24 hours Dietary Recall, Food Frequency Intake Questionnaire and Food Register Methods) to determine iron, copper and zinc intake; anthropometry (weight and height) to check BMI; biochemistry (measure of serum iron level through a Diagnóstica kit in vitro; ferritin through Immulite kit, and atomic absorption spectrophotometry for biochemical evaluation of serum iron, ferritin, copper and zinc. Spearman coefficient correlation was used for statistical analysis. Results: forty seven adolescents during pubertal growth spurt showed adequate ingestion: iron (95% and 36%), copper (53% and 57%) and zinc (21% and 21%) in males and females, respectively. Most of them were eutrophic according to the BMI percentiles. Biochemically, boys presented normal values for serum iron and zinc in the whole sample, 95% for copper and 84% for ferritin. Girls also presented normal values for iron and zinc values in the whole sample, 96.4% for copper and 96% for ferritin. There were no statistically significant correlation between BMI and serum Fe, ferritin, Cu and Zn concentrations and between serum concentration and dietetic ingestion of the studied minerals, neither between serum iron and ferritin. Conclusions: it is not clear if serum levels of Zn and Cu are floating during the growth process or if each adolescent has a stable level of these minerals during the pubertal growth spurt. Normal Fe, Cu and Zn serum levels in most adolescents evaluated may reflect the organism ability to accomplish homeostatic adjustments.
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    High molecular weight kininogen as substrate for cathepsin B
    (Walter de Gruyter & Co, 2004-06-01) Barros, NMT; Tersariol, ILS; Oliva, MLV; Araujo, M. S.; Sampaio, CAM; Juliano, L.; Motta, G. da; Universidade Federal de São Paulo (UNIFESP); UMC
    We investigated the influence of pH and divalent cations (Zn2+, Mg2+ and Ca2+) on high molecular weight kininogen processing by cathepsin B. At pH 6.3, high molecular weight kininogen is hydrolyzed by cathepsin B at three sites generating fragments of 80, 60 and 40 kDa. Cathepsin B has kininogenase activity at this pH which is improved in the absence of divalent cations. At pH 7.35, high molecular weight kininogen is slightly cleaved by cathepsin B into fragments of 60 kDa, and cathepsin B kininogenase activity is impaired. Our results suggest that high molecular weight kininogen is a substrate for cathepsin B under pathophysiological conditions.
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    Plasma zinc, copper, and erythrocyte superoxide dismutase in children with phelylketonuria
    (Elsevier B.V., 1999-06-01) Fisberg, R. M.; Da Silva-Femandes, M. E.; Fisberg, M.; Schmidt, B. J.; Universidade Federal de São Paulo (UNIFESP)
    Children with phenylketonuria (PKU) are treated with semisynthetic diets restricted in phenylalanine (PHE). the formulae must supply those trace elements and vitamins that are usually supplied by whole protein foods. We studied the effects of phenylalaline restricted diets in 42 children with PKU (P) and 31 normal (N) children, aged 1-12 y, divided into two groups (below and above 7 y). Plasma zinc and copper were analyzed by means of atomic spectrophotometry, and superoxide dismutase (CuZnSOD) activity was measured in erythrocytes, through NET inhibition and its profile, as determined by isoelectric focalization. Plasma zinc of PKU children greater than or equal to 7 years old was significantly lower than that in the control group (17 mu mol/L versus 20 mu mol/L) but still within the normal range; in children <7 years no substantial differences were found between the two groups. Plasma copper was not statistically different between PKU and normal children. Qualitative activity of CuZnSOD presented the same electrophoretic profile in both normal and PKU. Quantitative activity was not different in both P (1210 U/g Hb <7 versus 1328 U/g hemoglobin (Hb) greater than or equal to 7) and N (1675 U/g Hb <7 versus 1367 U/g Hb greater than or equal to 7). We concluded that children with PKU presented normal mean levels of zinc and copper, with preserved function, measured by enzyme activity. (C) Elsevier Science Inc. 1999.
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    Transthyretin is a metallopeptidase with an inducible active site
    (Portland Press Ltd, 2012-05-01) Liz, Marcia A.; Leite, Sergio C.; Juliano, Luiz [UNIFESP]; Saraiva, Maria J.; Damas, Ana M.; Bur, Daniel; Sousa, Monica M.; IBMC; Universidade Federal de São Paulo (UNIFESP); Univ Porto; Actel Pharmaceut Ltd
    TTR (transthyretin) was found recently to possess proteolytic competency besides its well-known transport capabilities. It was described as a cryptic serine peptidase cleaving multiple natural substrates (including beta-amyloid and apolipoprotein A-I) involved in diseases such as Alzheimer's disease and atherosclerosis. in the present study, we aimed to elucidate the catalytic machinery of TTR. All attempts to identify a catalytic serine residue were unsuccessful. However, metal chelators abolished TTR activity. Proteolytic inhibition by EDTA or 1,10-phenanthroline could be reversed with Zn2+ and Mn2+. These observations, supported by analysis of three-dimensional structures of TTR complexed with Zn2+, led to the hypothesis that TTR is a metallopeptidase. Site-directed mutagenesis of selected amino acids unambiguously confirmed this hypothesis. the TTR active site is inducible and constituted via a protein rearrangement resulting in similar to 7% of proteolytically active TTR at pH 7.4. the side chain of His(88) is shifted near His(90) and Gin(92) establishing a Zn2+-chelating pattern HXHXE not found previously in any metallopeptidase and only conserved in TTR of humans and some other primates. Point mutations of these three residues yielded proteins devoid of proteolytic activity. Glu(72) was identified as the general base involved in activation of the catalytic water. Our results unveil TTR as a metallopeptidase and define its catalytic machinery.
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    Zinc nutritional status and its relationships with hyperinsulinemia in obese children and adolescents
    (Humana Press Inc, 2004-08-01) Marreiro, DDN; Fisberg, Mauro [UNIFESP]; Cozzolino, SMF; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP); Sao Marcos Univ
    A perturbation of zinc metabolism has been noted in subjects with obesity. the present work intends to investigate whether the zinc nutritional status is associated with hyperinsulinemia in obesity. A study was carried out in a group of obese children and adolescents (n=23) and compared to a control group (n=21), both between 7 and 14 yr of age. Software analyzed diet information from 3-d food records. Body composition was evaluated by body mass index (BMI), bioelectrical impedance, and skin-fold measurements. Zinc nutritional status was evaluated by Zn determination in plasma, erythrocyte, and 24-h urine, by atomic absorption spectrophotometry (lambda=213.9 nm). Insulin was measured by radioimmunoassay (Linco Res). Diets consumed by both groups had marginal concentrations of zinc. Zinc concentrations in plasma and erythrocytes were significantly lower in the obese group. Urinary zinc excretion and serum insulin were significantly higher in the same group, although the insulinemia and the parameters of zinc nutritional status were not significantly correlated. As a result, considering that zinc is part of the synthesis and secretion of this hormone, an assessment is necessary of the possible participation of the oligoelement in the mechanisms of insulin resistance, commonly present in obese patients.
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    Zinc nutritional status in obese children and adolescents
    (Humana Press Inc, 2002-05-01) Marreiro, Dilina do Nascimento; Fisberg, Mauro [UNIFESP]; Cozzolino, Silvia Maria Franciscato; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP); Sao Marcos Univ
    Studies in animals and humans have corroborated that zinc (Zn) metabolism is altered in obesity. The present work intends to evaluate the Zn nutritional status in obese children and adolescents by the determination of some biochemical parameters and analyses of the diets. The investigation was carried out in a group of obese children and adolescents (n = 23) and compared to a control group (n = 21), both between 7 and 14 yr of age. A software analyzed diet information from 3-d food records. Body composition was evaluated by body mass index, bioelectrical impedance, and skinfold measurements. Zinc nutritional status was evaluated by Zn determination in plasma, erythrocyte, and 24-h urine, by atomic absorption spectrophotometry (lambda = 213.9 nm). Diets consumed by both groups had marginal concentrations of zinc. Zinc concentrations in plasma and erythrocytes were significantly lower in the obese group. Urinary zinc excretion was significantly higher in the same group. The results allowed one to conclude that zinc nutritional status in obese individuals is altered.