38 resultados para investigation of head-first binding of substrate with the phe557 mutant soybean lipoxygenase-1

em Repositório Institucional UNESP - Universidade Estadual Paulista "Julio de Mesquita Filho"


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A disposable pencil graphite electrode modified with dsDNA was used in combination with square wave voltammetry in order to evaluate the interaction of DNA with the textile dyes Disperse Orange 1 (DO1) and Disperse Red 1 (DR1), and with the products of their electrolysis. Significant changes in the characteristic oxidation peaks of the guanine and adenine moieties of immobilized dsDNA were observed after incubation of the modified electrode for 180 s in solutions of the dyes in their original forms. The same was observed using the electrolysis products obtained by oxidation and reduction conversions. The oxidation peak currents of the guanine and adenine moieties decreased when the concentrations of DO1 and DR1 were increased up to 5.0 × 10 -6 and 1.0 × 10-6 mol L-1, respectively; the signal decreases were more pronounced after interaction with the oxidized dyes, compared to the reduced compounds. The interactions between DNA and DO1, DR1, and the electrolyzed dyes were further investigated by UV-vis spectrophotometry in solution, and different effects such as hypochromism and hyperchromism were observed in the resulting DNA spectra. The investigated interactions showed clear evidence of changes in the DNA structure, and suggested a predominant intercalation mode leading to damage in the biomolecule. © 2013 Elsevier B.V.

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To evaluate the prevalence of metabolic disorders in patients with staghorn calculi treated at the Regional Center of Lithiasis Metabolic Studies in central region of Såo Paulo State, Brazil. Between February 2000 and February 2008, 630 patients with urinary calculi were evaluated in the lithiasis outpatient clinic. Thirty-seven of them had staghorn calculi (35 women and 2 men). The inclusion criteria for the metabolic investigation included the absence of urological manipulation 30 days before the examination, negative urine culture and creatinine clearance > 60 mL/min. The protocol for metabolic investigation consisted of qualitative search for cystinuria. Two non-consecutive 24-hour urine samples collected to measure calcium, phosphorus, uric acid, sodium, potassium, magnesium, oxalate and citrate, and serum calcium levels, phosphorus, uric acid, sodium, potassium, magnesium, chloride, parathormone and urine pH. Among patients with lithiasis, 5.9% (37/630) had staghorn calculus and in 48.6% (18/37) were diagnosed with urinary infection. The females were predominant for 94.5% of cases. The calculi were unilateral in 31 of cases and bilateral in six. Metabolic abnormalities were found in 68.2% of patients with hypercalciuria (64.2%) and hypocitraturia (53.3%) being the most common disorders. The presence of metabolic disorders in nearly 70% of patients with staghorn calculus reinforces the necessity for evaluation of these patients. The diagnosis and treatment of identified metabolic abnormalities can contribute to the prevention of recurrent staghorn calculi.

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The objective of this study was to evaluate the chemical alterations of the substrate in the cultivation of peppers grown in coconut husk fiber, in a protected environment. Initially, 160 pepper plants ('Eppo') were divided into four blocks, where two pots per block were analyzed every 21 days after transplanting. The cultivation of pepper was carried out in plastic pots of 13 L, containing coconut husk fiber, and placed in double rows with a spacing of 0.5×0.8 m between single rows and 1.10 m between double rows. After removal of the plants from the pots, individual samples of substrate (approximately 1 L) were collected from each pot and dried at ambient temperature. The levels of Ca, Mg, S, Cl, Na, B, Fe, Mn, Cu and Zn were determined for all periods of the cultivation. These analyses were performed using the method of extraction 1:1.5 v/v. There was an increase in the levels of all the nutrients evaluated. Further studies should be conducted to develop a better nutrient solution.

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A model for pulmonary paracoccidioidomycosis in the hamster is described. The disease was induced by intratracheal inoculation of 1.7 x 10(5) viable yeast forms of P. brasiliensis. Lung histopathology, dissemination lesions and humoral and cellular immune responses were investigated at intervals up to 24 weeks after infection. Humoral immunity was studied by immunodiffusion and complement fixation tests. Cell-mediated immunity was evaluated in vitro by the macrophage migration inhibition test in the presence of phytohaemagglutinin and P. brasiliensis soluble antigen, and in vivo by the paracoccidioidin test. Thirty out of 35 infected animals (85.7%) developed pulmonary paracoccidioidomycosis. Dissemination lesions were observed in regional lymph nodes (82.8%), liver (8.5%) and spleen (5.7%). Lung involvement was mainly around bronchi and vessels. Regional lymph nodes were severely involved from the fourth week on, acquiring a pseudotumoral aspect at later stages. Specific antibodies were detected from the fourth week on, with titres increasing progressively. The cellular immune response to phytohaemagglutinin was intact throughout the experiment and the response to P. brasiliensis antigen was already detectable by the second week and remained positive to the end of the experiment. The skin test became positive from the fourth week on. Inoculation by the intratracheal route represents a highly effective way of infecting hamsters with P. brasiliensis, with the induction of localized disease, good antibody production and intact cell immunity.

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The structural evolution on the drying of wet sonogels of silica with the liquid phase exchanged by acetone, obtained from tetraethoxisilane sonohydrolysis, was studied in situ by small-angle x-ray scattering (SAXS). The periods associated to the structural evolution as determined by SAXS are in agreement with those classical ones established on basis of the features of the evaporation rate of the liquid phase in the obtaining of xerogels. The wet gel can be described as formed by primary particles (microclusters), with characteristic length a ∼ 0.67 nm and surface which is fractal, linking together to form mass fractal structures with mass fractal dimension D=2.24 in a length scale ξ∼6.7 nm. As the network collapses while the liquid/vapor meniscus is kept out of the gel volume, the mass fractal structure becomes more compacted by increasing D and decreasing ξ, with smoothing of the fractal surface of the microclusters. The time evolution of the density of the wet gels was evaluated exclusively from the SAXS parameters ξ, D, and a. The final dried acetone-exchanged gel presents Porod's inhomogeneity length of about 2.8 nm and apparently exhibits an interesting singularity D →3, as determined by the mass fractal modeling used to fit the SAXS intensity data for the obtaining of the parameters ξ and D.

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We report the results of a search for a narrow resonance decaying into two photons in 1.1fb-1 of data collected by the D0 experiment at the Fermilab Tevatron Collider during the period 20022006. We find no evidence for such a resonance and set a lower limit on the mass of a fermiophobic Higgs boson of mhf>100GeV at the 95% C.L. This exclusion limit exceeds those obtained in previous searches at the Fermilab Tevatron and covers a significant region of the parameter space B(hf→I I ) vs mhf which was not accessible at the CERN Large Electron-Positron Collider. © 2008 The American Physical Society.

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BACKGROUND: Leprosy can have its course interrupted by type 1 and 2 reactional episodes, the last named of erythema nodosum leprosum (ENL). Thalidomide has been the medication of choice for the control of ENL episodes since 1965. OBJECTIVES: These episodes can repeat and cause damages to the patient. In order to prevent these episodes, an extra dose of 100 mg/day thalidomide was used during six months, followed by a follow-up period of six more months after thalidomide discontinuation. METHODS: We included 42 patients with multibacillary (MB) leprosy who had episodes of ENL. They were male and female patients aged between 18 and 84 years. RESULTS: Of the 42 patients, 39 (92.85%) had the lepromatous form and three (7.15%) had the borderline form. We found that 100% of patients had no reactional episode during the use of the drug. During the follow-up period after thalidomide discontinuation, 33 (78.57%) patients had no reactional episode and nine (21.43%), all of them with the lepromatous form, had mild episodes, which were controlled using non-steroidal anti-inflammatory. There were no thalidomide-related side effects. CONCLUSION: A maintenance dose of 100 mg/day of thalidomide showed to be effective to prevent repeated type 2 reactional episodes of ENL.

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For any finite commutative ring B with an identity there is a strict inclusion B[X; Z(0)] subset of B[X; Z(0)] subset of B[X; 1/2(2)Z(0)] of commutative semigroup rings. This work is a continuation of Shah et al. (2011) [8], in which we extend the study of Andrade and Palazzo (2005) [7] for cyclic codes through the semigroup ring B[X; 1/2; Z(0)] In this study we developed a construction technique of cyclic codes through a semigroup ring B[X; 1/2(2)Z(0)] instead of a polynomial ring. However in the second phase we independently considered BCH, alternant, Goppa, Srivastava codes through a semigroup ring B[X; 1/2(2)Z(0)]. Hence we improved several results of Shah et al. (2011) [8] and Andrade and Palazzo (2005) [7] in a broader sense. Published by Elsevier Ltd

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NAPc2, an anticoagulant protein from the hematophagous nematode Ancylostoma caninum evaluated in phase-II/IIa clinical trials, inhibits the extrinsic blood coagulation pathway by a two step mechanism, initially interacting with the hitherto uncharacterized factor Xa exosite involved in macromolecular recognition and subsequently inhibiting factor VIIa (K-i = 8.4 pM) of the factor VIIa/tissue factor complex. NAPc2 is highly flexible, becoming partially ordered and undergoing significant structural changes in the C terminus upon binding to the factor Xa exosite. In the crystal structure of the ternary factor Xa/NAPc2/selectide complex, the binding interface consists of an intermolecular antiparallel beta-sheet formed by the segment of the polypeptide chain consisting of residues 74-80 of NAPc2 with the residues 86-93 of factor Xa that is additional maintained by contacts between the short helical segment (residues 67-73) and a turn (residues 26-29) of NAPc2 with the short C-terminal helix of factor Xa (residues 233-243). This exosite is physiologically highly relevant for the recognition and inhibition of factor X/Xa by macromolecular substrates and provides a structural motif for the development of a new class of inhibitors for the treatment of deep vein thrombosis and angioplasty. (c) 2006 Elsevier Ltd. All rights reserved.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Lead lanthanum zirconate titanate (PLZT) thin films with stoichiometry (9/65/35) were prepared by a dip-coating process using a polymeric organic solution. The solution viscosity was adjusted in the range of 15-56 cP. Silicon (100) substrates were previously cleaned and then immersed in the solution. The withdrawal speed of substrate from the solution was adjusted within a range of 5 to 20 mm/min. The coated substrates were thermally treated in the 450-700 degreesC temperature range. Surface roughness and crystallization of these films are strongly dependent on the annealing conditions. Infrared and X-ray diffraction data for PLZT powders heat-treated at 650 degreesC for 3 h show that the material is free of carbonate phases and crystalline. (C) 2001 Elsevier B.V. B.V. All rights reserved.

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The 43,000-molecular-weight (43K) soluble glycoprotein was detected in sera of patients with paracoccidioidomycosis by the immunoblot technique by using as the probe rabbit monospecific antisera to this fraction. The 43K antigen was present before treatment in sera of patients with the acute (juvenile) form; it started to disappear from circulation after 10 months of chemotherapy, and it was undetectable afer 2 years of treatment. In the chronic cases, the 43K antigen was detected in patients without treatment, and it was absent in the healed cases. The detection of the 43K protein specific to Paracoccidioides brasiliensis may be important for its diagnostic value as well as for modulation of the host immune response.

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Transitional cell carcinoma (TCC) of the bladder is a neoplasm with variability in its clinical behavior. Although there are several studies correlating stage and ABO isoantigen expression with invasiveness, there is no single predictor factor to assess the potential invasiveness, especially in the low grade, non-invasive TCC. In the present study we evaluated the correlation of histological grade plus stage and the expression of beta human chorionic gonadotropin (beta-hCG), in 100 cases of TCC, with the clinical behavior. These features were correlated with tumor progression in patients with at least two years of follow up. We observed more aggressiveness in G4 group (high grade and invasive) (93% had tumor progression) when compared to G1 group (low grade and superficial) (11% had tumor progression). However in 25.5% of the TCC cases (groups G2: low grade and invasive and G3: high grade and superficial) the clinical behavior was intermediate, showing some limitation in using grading and staging only, as a predictive factor. There was an expression of beta-hCG in 21.4% of the cases in up to 25% of the tumor cells without any trophoblastic morphology. These beta-hCG producing TCC had a strong correlation with aggressiveness: 39.1% and 12.8% of the TCC expressed beta-hCG with and without tumor progression, respectively.

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In canine visceral leishmaniasis (CVL), the abnormalities most commonly observed in clinical examination on the animals are lymphadenomegaly and skin lesions. Dogs are the main domestic reservoir for the protozoon Leishmania (L.) chagasi and the skin is the main site of contamination by the vector insect. Some protozoa use apoptosis as an immunological escape mechanism. The aim of this study was to correlate the presence of apoptosis with the parasite load and with the inflammatory response in the skin and lymph nodes of dogs naturally infected with Leishmania (L.) chagasi. Thirty-three dogs from the municipality of Araçatuba (São Paulo, Brazil) were used, an endemic area for CVL. Muzzle, ear and abdominal skin and the popliteal, subscapular, iliac and mesenteric lymph nodes of symptomatic (S), oligosymptomatic (O) and asymptomatic (A) dogs were analyzed histologically. The parasite load and percentage apoptosis were evaluated using an immunohistochemical technique. Microscopically, the lymph nodes presented chronic lymphadenitis and the skin presented plasmacytic infiltrate and granulomatous foci in the superficial dermis, especially in the ear and muzzle regions. The inflammation was most severe in group S. The parasite load and apoptotic cell density were also greatest in this group. The cause of the lymphoid atrophy in these dogs was correlated with T lymphocyte apoptosis, thus leaving the dogs more susceptible to CVL. The peripheral lymph nodes presented the greatest inflammatory response. Independent of the clinical picture, the predominant inflammatory response was granulomatous and plasmacytic, both in the skin and in the peripheral lymph nodes. The ear skin presented the greatest intensity of inflammation and parasite load, followed by the muzzle skin, in group S. The ear skin area presented a non-significant difference in cell profile, with predominance of macrophages, and a significant difference from group A to groups O and S. It was seen that in these areas, there were high densities of parasites and cells undergoing apoptosis, in group S. The association between apoptosis and parasite load was not significant in the lymph nodes, but in the muzzle regions and at the ear tips, a positive correlation was seen between the parasite load and the density of cells undergoing apoptosis. The dogs in group S had the highest parasite load and the greatest number of apoptotic cells, thus suggesting that the parasite had an immune evasion mechanism, which could be proven statistically in the skin. © 2012 Elsevier B.V.