49 resultados para Q_(10)
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Singlet molecular oxygen O(2)((1)Delta(g)) is a potent oxidant that can react with different biomolecules, including DNA, lipids and proteins. Many polycyclic aromatic hydrocarbons have been studied as O(2)((1)Delta(g)) chemical traps. Nevertheless, a suitable modification in the polycyclic aromatic ring must be made to increase the yield of O(2)((1)Delta(g)) chemical trapping. With this goal, an anthracene derivative, diethyl-3,3 '-(9,10-anthracenediyl)bisacrylate (DADB), was obtained from the reaction of 9,10-dibromoanthracene and ethyl acrylate through the Heck coupling reaction. The coupling of ethyl acrylate with the anthracene ring produced a new lipophilic, esterified, fluorescent probe reactive toward O(2)((1)Delta(g)). This compound reacts with O(2)((1)Delta(g)) at a rate of k(r) = 1.69 x 10(6) M(-1) s(-1) forming a stable endoperoxide (DADBO(2)), which was characterized by UV-Vis, fluorescence, HPLC/MS and (1)H and (13)C NMR techniques. The photophysical, photochemical and thermostability features of DADB were also evaluated. Furthermore, this compound has the potential for great application in biological systems because it is easily synthetized in large amount and generates specific endoperoxide (DADBO(2)), which can be easily detected by HPLC tandem mass spectrometry (HPLC/MS/MS).
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Heart failure (HF) is associated with changes in the skeletal muscle (SM) which might be a consequence of the unbalanced local expression of pro- (TNF-alpha) and anti- (IL-10) inflammatory cytokines, leading to inflammation-induced myopathy, and SM wasting. This local effect of HF on SM may, on the other hand, contribute to systemic inflammation, as this tissue actively secretes cytokines. Since increasing evidence points out to an anti-inflammatory effect of exercise training, the goal of the present study was to investigate its effect in rats with HF after post-myocardial infarction (MI), with special regard to the expression of TNF-alpha and IL-10 in the soleus and extensor digitorum longus (EDL), muscles with different fiber composition. Wistar rats underwent left thoracotomy with ligation of the left coronary artery, and were randomly assigned to either a sedentary (Sham-operated and MI sedentary) or trained (Sham-operated and MI trained) group. Animals in the trained groups ran on a treadmill (0% grade at 13-20 m/min) for 60 min/day, 5 days/week, for 8-10 weeks. The training protocol was able to reverse the changes induced by MI, decreasing TNF-alpha protein (26%, P < 0.05) and mRNA (58%, P < 0.05) levels in the soleus, when compared with the sedentary MI group. Training also increased soleus IL-10 expression (2.6-fold, P < 0.001) in post-MI HF rats. As a consequence, the IL-10/TNF-alpha ratio was increased. This ""anti-inflammatory effect"" was more pronounced in the soleus than in the EDL, suggesting a fiber composition dependent response. (C) 2009 Elsevier Ltd. All rights reserved.
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Little information is available concerning early specialization and competitive success in judo across the early training years. Thus, the present objective was to verify the stability of individual competitive performance of a state-level championship for judo athletes who had been previously successful. For this, 406 athletes from six age groups (9 to 20+ years old) of each sex were followed for 10 years. Using recorded data from the Sao Paulo State Judo Federation beginning in 1999, the scores and standings for these judo players were analyzed. The proportion of medal winners during this period was not constant, differing from the grand mean in all groups of both 204 males and 202 females. At the end of this period, only 7% of the male and 5% of the female athletes had maintained their competitive levels. Successful competitive performance in early judo competition was not associated with success later in adulthood.
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PIBIC-CNPq-Conselho Nacional de Desenvolvimento Cientifico e Technologico
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The aim of this study was to examine the influence of the performance level of athletes on pacing strategy during a simulated 10-km running race, and the relationship between physiological variables and pacing strategy. Twenty-four male runners performed an incremental exercise test on a treadmill, three 6-min bouts of running at 9, 12 and 15 km h(-1), and a self-paced, 10-km running performance trial; at least 48 h separated each test. Based on 10-km running performance, subjects were divided into terziles, with the lower terzile designated the low-performing (LP) and the upper terzile designated the high-performing (HP) group. For the HP group, the velocity peaked at 18.8 +/- A 1.4 km h(-1) in the first 400 m and was higher than the average race velocity (P < 0.05). The velocity then decreased gradually until 2,000 m (P < 0.05), remaining constant until 9,600 m, when it increased again (P < 0.05). The LP group ran the first 400 m at a significantly lower velocity than the HP group (15.6 +/- A 1.6 km h(-1); P > 0.05) and this initial velocity was not different from LP average racing velocity (14.5 +/- A 0.7 km h(-1)). The velocity then decreased non-significantly until 9,600 m (P > 0.05), followed by an increase at the end (P < 0.05). The peak treadmill running velocity (PV), running economy (RE), lactate threshold (LT) and net blood lactate accumulation at 15 km h(-1) were significantly correlated with the start, middle, last and average velocities during the 10-km race. These results demonstrate that high and low performance runners adopt different pacing strategies during a 10-km race. Furthermore, it appears that important determinants of the chosen pacing strategy include PV, LT and RE.
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This article describes a study of the behavior of a mixture of amines and amides, commercially known as Dodigen 213-N (D-213 N), as a corrosion inhibitor for ASTM 1010 mild steel in 10% w/w HCl solution. The concentration range used was 1 x 10(-5) M to 8 x 10(-4) M. The weight loss and electrochemical techniques used were corrosion potential measurement, anodic and cathodic polarization curves, and electrochemical impedance spectroscopy (EIS). The solution temperature was 50 +/- A 1 A degrees C and it was naturally aerated. The corrosion potential values shifted to slightly more positive values, thus indicating mixed inhibitor behavior. The anodic and cathodic polarization curves showed that D-213 N is an effective corrosion inhibitor, since both the anodic and the cathodic reactions were polarized in comparison with those obtained without inhibitor. For all concentrations the cathodic polarization curves were more polarized than the anodic ones. The inhibition efficiency was in the range 75-98%, calculated from values of weight loss and corrosion current density, i (corr), obtained by extrapolation of Tafel cathodic linear region.
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We report on the detection of the transport Barkhausen-like noise (TBN) in polycrystalline samples of Bi(1.65)Pb(0.35)Sr(2)Ca(2) Cu(3)O(10+delta) (Bi-2223) which were subjected to different uniaxial compacting pressures. The transport Barkhausen-like noise was measured when the sample was subjected to an ac triangular-shape magnetic field (f similar to 1 Hz) with maximum amplitude B(max) approximate to 5.5 mT, in order to avoid the flux penetration within the superconducting grains. Analysis of the TBN signal, measured for several values of excitation current density, indicated that the applied magnetic field in which the noise signal first appears, B(a)(t(i)), is closely related to the magnetic-flux pinning capability of the material. The combined results are consistent with the existence of three different superconducting levels within the samples: (i) the superconducting grains; (ii) the superconducting clusters; and (iii) the weak-links. We finally argue that TBN measurements constitute a powerful tool for probing features of the intergranular transport properties in polycrystalline samples of high-T(c) superconductors. (C) 2010 Elsevier B.V. All rights reserved.
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Experimental and theoretical studies on the magnetic field dependence of the electrical resistance R(B(a)) and the transport noise (TN) in polycrystalline high-T(c) superconductors subjected to different uniaxial compacting pressures were conducted. X-ray diffraction rocking curves were performed in different surfaces of the samples in order to investigated the degree of texture The results indicated an improvement of the degree of texture with increasing the uniaxial compacting pressure In theoretical simulations of the data, the polycrystalline superconductors were described as a series-parallel array of Josephson devices The intergranular magnetic field is described within the framework of the intragranular flux-trapping model and the distribution of the grain-boundary angles is assumed to follow the Rayleigh statistical function The proposed model describes well the experimental magnetoresistance R(B(a)) data We have found that the behavior of the R(B(a)) curves changes appreciably when different uniaxially compacting pressures are applied to the sample and such a changes are reproduced by the model when different grain-boundary angles distributions are used In addition, changes in the R(B(a)) dependence have their counterparts in the experimental transport noise signals (C) 2009 Elsevier B.V. All rights reserved
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Malnutrition modifies resistance to infection by impairing a number of physiological processes including hematopoesis and the immune response. In this study, we examined the production of Interleukin-4 (IL-4) and IL-10 in response to lipopolysaccharide (LPS) and also evaluated the cellularity of the blood, bone marrow, and spleen in a mouse model of protein-energy malnutrition. Two-month-old male Swiss mice were subjected to protein-energy malnutrition (PEM) with a low-protein diet (4%) as compared to the control diet (20%). When the experimental group lost approximately 20% of their original body weight, the animals from both groups received 1.25 mu g of LPS intravenously. The Cells ill the blood, bone marrow, and spleen were counted, and circulating levels of IL-4 and IL-10 were evaluated in animals stimulated with LPS. Cells from the spleen, bone marrow, and peritoneal cavity of non-inoculated animals were collected for Culture to evaluate the production of IL-4 and IL-10 after stimulating these cells with 1.25 mu g of LPS in vitro. Malnourished animals presented leucopenia and a severe reduction in bone marrow, spleen, and peritoneal cavity cellularity before and after Stimulus with LPS. The circulating levels of IL-10 were increased in malnourished animals inoculated with LPS when compared to control animals, although the levels of IL-4 did not differ. In cells cultured with LPS, we observed high levels of IL-10 in the bone marrow cells of malnourished animals. These findings suggest that malnourished mice present a deficient immune response to LPS. These alterations may be partly responsible for the immunodeficiency observed in these malnourished mice.
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A sensitive and reproducible stir bar-sorptive extraction and high-performance liquid chromatography-UV detection (SBSE/HPLC-UV) method for therapeutic drug monitoring of carbamazepine, carbamazepine-10,11-epoxide, phenytoin and phenobarbital in plasma samples is described and compared with a liquid:liquid extraction (LLE/HPLC-UV) method. Important factors in the optimization of SBSE efficiency such as pH, extraction time and desorption conditions (solvents, mode magnetic stir, mode ultrasonic stir, time and number of steps) assured recoveries ranging from 72 to 86%, except for phenytoin (62%). Separation was obtained using a reverse phase C-18 column with UV detection (210 nm). The mobile phase consisted of water: acetonitrile (78:22, v/v). The SBSE/HPLC-UV method was linear over a working range of 0.08-40.0 mu g mL(-1) for carbamazepine, carbamazepine-10,11-epoxide and phenobarbital and 0.125-40.0 mu g mL(-1) for phenytoin, The intra-assay and inter-assay precision and accuracy were studied at three concentrations (1.0, 4.0 and 20.0 mu g mL(-1)). The intra-assay coefficients of variation (CVs) for all compounds were less than 8.8% and all inter-CVs were less than 10%. Limits of quantification were 0.08 mu g mL(-1) for carbamazepine, carbamazepine-10,11-epoxide and phenobarbital and 0.125 mu g mL(-1) for phenytoin. No interference of the drugs normally associated with antiepileptic drugs was observed. Based on figures of merit results, the SBSE/HPLC-UV proved adequate for antiepileptic drugs analyses from therapeutic levels. This method was successfully applied to the analysis of real samples and was as effective as the LLE/HPLC-UV method. (c) 2008 Elsevier B.V. All rights reserved.
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10-(Octyloxy) decyl-2-(trimethylammonium) ethyl phosphate (ODPC) is an alkylphospholipid that can interact with cell membranes because of its amphiphilic character. We describe here the interaction of ODPC with liposomes and its toxicity to leukemic cells with an ED-50 of 5.4, 5.6 and 2.9 pM for 72 h of treatment for inhibition of proliferation of NB4, U937 and K562 cell lines, respectively, and lack of toxicity to normal hematopoietic progenitor cells at concentrations up to 25 pM. The ED-50 for the non-malignant HEK-293 and primary human umbilical vein endothelial cells (HUVEC) was 63.4 and 60.7 mu M, respectively. The critical micellar concentration (CMC) of ODPC was 200 mu M. Dynamic light scattering indicated that dipalmitoylphosphatidylcholine (DPPC) liposome size was affected only above the CMC of ODPC. Differential calorimetric scanning (DCS) of liposomes indicated a critical transition temperature (T(c)) of 41.5 degrees C and an enthalpy (Delta H) variation of 7.3 kcal mol(-1). The presence of 25 mu M ODPC decreased T(c) and Delta H to 393 degrees C and 4.7 kcal mol(-1), respectively. ODPC at 250 mu M destabilized the liposomes (36.3 degrees C. 0.46 kcal mol(-1)). Kinetics of 5(6)-carboxyfluorescein (CF) leakage from different liposome systems indicated that the rate and extent of CF release depended on liposome composition and ODPC concentration and that above the CMC it was instantaneous. Overall, the data indicate that ODPC acts on in vitro membrane systems and leukemia cell lines at concentrations below its CMC, suggesting that it does not act as a detergent and that this effect is dependent on membrane composition. (C) 2010 Elsevier B.V. All rights reserved.
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Multiple endocrine neoplasia type 2 is characterized by germline mutations in RET. For exon 10, comprehensive molecular and corresponding phenotypic data are scarce. The International RET Exon 10 Consortium, comprising 27 centers from 15 countries, analyzed patients with RET exon 10 mutations for clinical-risk profiles. Presentation, age-dependent penetrance, and stage at presentation of medullary thyroid carcinoma (MTC), pheochromocytoma, and hyperparathyroidism were studied. A total of 340 subjects from 103 families, age 4-86, were registered. There were 21 distinct single nucleotide germline mutations located in codons 609 (45 subjects), 611 (50), 618 (94), and 620 (151). MTC was present in 263 registrants, pheochromocytoma in 54, and hyperparathyroidism in 8 subjects. Of the patients with MTC, 53% were detected when asymptomatic, and among those with pheochromocytoma, 54%. Penetrance for MTC was 4% by age 10, 25% by 25, and 80% by 50. Codon-associated penetrance by age 50 ranged from 60% (codon 611) to 86% (620). More advanced stage and increasing risk of metastases correlated with mutation in codon position (609-620) near the juxtamembrane domain. Our data provide rigorous bases for timing of premorbid diagnosis and personalized treatment/prophylactic procedure decisions depending on specific RET exon 10 codons affected. Hum Mutat 32:51-58, 2011. (C) 2010 Wiley-Liss, Inc.
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P>Context Congenital generalized lipodystrophy, or Berardinelli-Seip syndrome, is a rare autosomal recessive disease caused by mutations in either the BSCL2 or AGPAT2 genes. This syndrome is characterized by an almost complete loss of adipose tissue usually diagnosed at birth or early infancy resulting in apparent muscle hypertrophy. Common clinical features are acanthosis nigricans, hepatomegaly with or without splenomegaly and high stature. Acromegaloid features, cardiomyopathy and mental retardation can also be present. Design We investigated 11 kindreds from different geographical areas of Brazil (northeast and southeast). All coding regions as well as flanking intronic regions of both genes were examined. Polymerase chain reaction (PCR) amplifications were performed using primers described previously and PCR products were sequenced directly. Results Four AGPAT2 and two BSCL2 families harboured the same set of mutations. BSCL2 gene mutations were found in the homozygous form in four kindreds (c.412C > T c.464T > C, c.518-519insA, IVS5-2A > G), and in two kindreds compound mutations were found (c.1363C > T, c.424A > G). In the other four families, one mutation of the AGPAT2 gene was found (IVS3-1G > C and c.299G > A). Conclusions We have demonstrated four novel mutations of the BSCL2 and AGPAT2 genes responsible for Berardinelli-Seip syndrome and Brunzell syndrome (AGPAT2-related syndrome).
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We have shown previously that nitric oxide (NO) controls platelet endothelial cell adhesion molecule (PECAM-1) expression on both neutrophils and endothelial cells under physiological conditions. Here, the molecular mechanism by which NO regulates lipopolysaccharide (LPS)-induced endothelial PECAM-1 expression and the role of interleukin (IL)-10 on this control was investigated. For this purpose, N-(G)-nitro-L-arginine methyl ester (L-NAME; 20 mg/kg/day for 14 days dissolved in drinking water) was used to inhibit both constitutive (cNOS) and inducible nitric oxide (iNOS) synthase activities in LPS-stimulated Wistar rats (5 mg/kg, intraperitoneally). This treatment resulted in reduced levels of serum NO. Under this condition, circulating levels of IL-10 was enhanced, secreted mainly by circulating lymphocytes, dependent on transcriptional activation, and endothelial PECAM-1 expression was reduced independently on reduced gene synthesis. The connection between NO, IL-10 and PECAM-1 expression was examined by incubating LPS-stimulated (1 mu g/ml) cultured endothelial cells obtained from naive rats with supernatant of LPS-stimulated lymphocytes, which were obtained from blood of control or L-NAME-treated rats. Supernatant of LPS-stimulated lymphocytes obtained from L-NAME-treated rats, which contained higher levels of IL-10, reduced LPS-induced PECAM-1 expression by endothelial cells, and this reduction was reversed by adding the anti-IL-10 monoclonal antibody. Therefore, an association between NO, IL-10 and PECAM-1 was found and may represent a novel mechanism by which NO controls endothelial cell functions.
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Background: Epidermodysplasia verruciformis (EV) is a rare genodermatosis with susceptibility to human papillomavirus (HPV) infection, and high risk of skin cancer considered a model of viral oncogenesis. Methods: Fifteen cases of EV plane wart (PW)-type lesions (EV) and 14 cases of PW in healthy individuals were subjected to immunohistochemical technique for cytokeratins (K) 1, 10, 14, 16, 4, involucrin, filaggrin and e-cadherin. Results: K1/10 showed retarded or negative expression in EV, being substituted by K14. Expression of K14 occurred in the basal and suprabasal layers in both groups, but in EV, its expression was observed up to the more superficial layers. Both groups showed positivity for K16 and K4, involucrin expression in lower levels of the spinous layer and unaltered filaggrin expression. E-cadherin expression was diminished at the koilocytotic foci of both lesions, more superficially in EV. Conclusion: Infection by HPV may alter the differentiation status of the epidermis, leading to a major expression of K14, delayed or absent expression of K1/10 and earlier involucrin expression, especially in EV. It also stimulates the expression of K16 and K4. Filaggrin expression is not altered, and e-cadherin is diminished in superficial koilocytotic cells` foci in EV.