999 resultados para ELISA anti-GP43


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The lack of a clear correlation between the levels of antibody to pertussis antigens and protection against disease lends credence to the possibility that cell-mediated immunity provides primary protection against disease. This phase I comparative trial had the aim of comparing the in vitro cellular immune response and anti-pertussis toxin (anti-PT) immunoglobulin G (IgG) titers induced by a cellular pertussis vaccine with low lipopolysaccharide (LPS) content (wP(low) vaccine) with those induced by the conventional whole-cell pertussis (wP) vaccine. A total of 234 infants were vaccinated at 2, 4, and 6 months with the conventional wP vaccine or the wP(low) vaccine. Proliferation of CD3(+) T cells was evaluated by flow cytometry after 6 days of peripheral blood mononuclear cell culture with stimulation with heat-killed Bordetella pertussis or phytohemagglutinin (PHA). CD3(+), CD4(+), CD8(+), and T-cell receptor gamma delta-positive (gamma delta(+)) cells were identified in the gate of blast lymphocytes. Gamma interferon, tumor necrosis factor alpha, interleukin-4 (IL-4), and IL-10 levels in super-natants and serum anti-PT IgG levels were determined using enzyme-linked immunosorbent assay (ELISA). The net percentage of CD3(+) blasts in cultures with B. pertussis in the group vaccinated with wP was higher than that in the group vaccinated with the wP(low) vaccine (medians of 6.2% for the wP vaccine and 3.9% for the wP(low) vaccine; P = 0.029). The frequencies of proliferating CD4(+), CD8(+), and gamma delta(+) cells, cytokine concentrations in supernatants, and the geometric mean titers of anti-PT IgG were similar for the two vaccination groups. There was a significant difference between the T-cell subpopulations for B. pertussis and PHA cultures, with a higher percentage of gamma delta(+) cells in the B. pertussis cultures (P < 0.001). The overall data did suggest that wP vaccination resulted in modestly better specific CD3(+) cell proliferation, and gamma delta(+) cell expansions were similar with the two vaccines.

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Background. Oxidative stress is a significant contributor to cardiovascular diseases (CVD) in haemodialysis (HD) patients, predisposing to the generation of oxidized low-density lipoprotein (oxLDL) or electronegatively charged LDL subfraction. Antioxidant therapy such as alpha-tocopherol acts as a scavenger of lipid peroxyl radicals attenuating the oxidative stress, which decreases the formation of oxLDL. The present study was designed to investigate the influence of the alpha-tocopherol supplementation on the concentration of electronegative low-density lipoprotein [LDL(-)], a minimally oxidized LDL, which we have previously described to be high in HD patients. Methods. Blood samples were collected before and after 120 days of supplementation by alpha-tocopherol (400 UI/day) in 19 stable HD patients (50 +/- 7.8 years; 9 males). The concentrations of LDL(-) in blood plasma [using an anti-LDL- human monoclonal antibody (mAb)] and the anti-LDL(-) IgG auto-antibodies were determined by ELISA. Calculation of body mass index (BMI) and measurements of waist circumference (WC), triceps skin folds (TSF) and arm muscle area (AMA) were performed. Results. The plasma alpha-tocopherol levels increased from 7.9 mu M (0.32-18.4) to 14.2 mu M (1.22-23.8) after the supplementation (P = 0.02). The mean concentration of LDL(-) was reduced from 570.9 mu g/mL (225.6-1241.0) to 169.1 mu g/mL (63.6-621.1) (P < 0.001). The anti-LDL(-) IgG auto-antibodies did not change significantly after the supplementation. The alpha-tocopherol supplementation also reduced the total cholesterol and LDL-C levels in these patients, from 176 +/- 42.3 mg/dL to 120 +/- 35.7 mg/dL (P < 0.05) and 115.5 +/- 21.4 mg/dL to 98.5 +/- 23.01 mg/dL (P < 0.001), respectively. Conclusion. The oral administration of alpha-tocopherol in HD patients resulted in a significant decrease in the LDL(-), total cholesterol and LDL-C levels. This effect may favour a reduction in cardiovascular risk in these patients, but a larger study is required to confirm an effect in this clinical setting.

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In this study, in vitro anti-T. cruzi activity assays of nifuroxazide (NX) analogues, such as 5-nitro-2-furfuryliden and 5-nitro-2-theniliden derivatives, were performed. A molecular modeling approach was also carried out to relate the lipophilicity potential ( LP) property and biological activity data. The majority of the NX derivatives showed increased anti-T. cruzi activity in comparison to the reference drug, benznidazole (BZN). Additionally, the 5-nitro-2-furfuryliden derivatives presented better pharmacological profile than the 5-nitro-2-theniliden analogues. The LP maps and corresponding ClogP values indicate that there is an optimum lipophilicity value, which must be observed in the design of new potential anti-T. cruzi agents. (c) 2009 Elsevier Ltd. All rights reserved.

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Leaf fractions of Wilbrandia ebracteata were investigated for anti-ulcerogenic effects in ethanol and indomethacin-induced gastric ulcer assays in mice. Protective anti-ulcer effects were detected only in the ethanol-induced ulcer assay effects after pre-treatment with MeOH extract, MeOH chlorophyll-free, chlorophyll residue, HEX, DCM, aqueous MeOH fraction, ethyl acetate (EtOAc) and aqueous fractions. A potent anti-ulcerogenic effect was determined after pre-treatment of animals with EtOAc fraction, which was fractionated for isolation of active constituents. Seven flavonoids, 3`,4`,5,6,7,8-hexahydroxyflavonol, orientin, isoorientin, vitexin, isovitexin, luteolin, 6-methoxi-luteolin were isolated from the leaves of W. ebracteata (Cucurbitaceae) by chromatographic methods and identified by their spectral data. The data suggest that flavonoids are active anti-ulcerogenic compounds from leaves of W. ebracteata. The ability of scavenging free radicals was evaluated by DPPH reduction assay by TLC of flavonoids isolated.

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Seroprevalence of Toxocara and Taenia solium and risk factors for infection with these parasites were explored in a long-term rural settlement in Sao Paula state, Brazil. An ELISA for the detection of anti-Toxocara IgG and IgE and anti-T. solium cysticerci was standardized using Toxocara excretory-secretory antigens (TES) obtained from the cultured second-stage larvae of T. canis and by vesicular fluid antigen from Taenia crassiceps cysticerci (VC). For cysticercosis, the reactive ELISA samples were assayed by Western blot using 18 kDa and 14 kDa proteins purified from VF. Out of 182 subjects, 25 (13.7%,) presented anti-Toxocora IgG and it positive correlation between total IgE and the reactive index of specific anti-TES IgE (P=0.0265) was found amongst the subjects found seropositive for anti-Toxocara IgG. In these individuals 38.0%. showed ocular manifestations. The frequency of anti-T. solium cysticerci confirmed by Western blot wits 0.6%, Seropositivity for Toxocara was correlated with low educational levels and the owning of dogs. Embryonated eggs of Toxocara spp. were found in 43.3% of the analysed areas.

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The seroprevalence of Toxocara canis and risk factors for infection with this parasite were explored in a rural settlement in Sao Paulo state, Brazil. Total IgA and IgE levels in 79 subjects were determined by turbidimetry and chemiluminescence, respectively. Total counts of leucocytes and erythrocytes and differential counts of leucocytes were made by flow cytometry. ELISA for the detection of anti-Toxocara IgG, IgA and IgE were standardized using Toxocara excretory-secretory antigens (TES) obtained from the cultured second-stage larvae of T. canis. Seventeen (21.5%) of the subjects were found positive for anti-Toxocara IgG, with no significant differences in such seropositivity with age or gender. Thirty (38%) of the subjects showed eosinophilia and 70 (89%) had elevated levels of total IgE. Among the 17 subjects found seropositive for anti-Toxocara IgG, the percentage of leucocytes represented by eosinophils (P=0.0069) and total levels of IgE (P=0.0452) were positively correlated with the levels of anti-TES IgE. Although anti-TES IgA was detected in 10 (59%) of the subjects, there was no significant correlation between the levels of total IgA and those of Toxocara-specific IgA. Only one of the 17 subjects found positive for anti-Toxocara IgG had attended a secondary school and all but two belonged to households with monthly incomes of < U.S.$100. In the study community at least, seropositivity may be related to poor living standards and lack of basic sanitary conditions. The presence of anti-Toxocara IgE and IgA may facilitate the diagnosis of toxocariasis and may well be useful for monitoring the success of treatment.

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The tamarind (Tamarindus indica L) is indigenous to Asian countries and widely cultivated in the American continents. The tamarind fruit pulp extract (ExT), traditionally used in spices, food components and juices, is rich in polyphenols that have demonstrated anti-atherosclerotic, antioxidant and immunomodulatory activities. This study evaluated the modulator effect of a crude hydroalcoholic ExT on some peripheral human neutrophil functions. The neutrophil reactive oxygen species generation, triggered by opsonized zymosan (OZ), n-formyl-methionyl-leucyl-phenylalanine (fMLP) or phorbol myristate acetate (PMA), and assessed by luminol- and lucigenin-enhanced chemiluminescence (LumCL and LucCL, respectively), was inhibited by ExT in a concentration-dependent manner. ExT was a more effective inhibitor of the PMA-stimulated neutrophil function [IC(50) (in mu g/10(6)cells) = 115.7 +/- 9.7 (LumCL) and 174.5 +/- 25.9 (LucCL)], than the OZ- [IC(50) = 248.5 +/- 23.1 (LumCL) and 324.1 +/- 34.6 (LucCL)] or fMLP-stimulated cells [IC(50) = 178.5 +/- 12.2 (LumCL)]. The ExT also inhibited neutrophil NADPH oxidase activity (evaluated by O(2) consumption), degranulation and elastase activity (evaluated by spectrophotometric methods) at concentrations higher than 200 mu g/10(6) cells, without being toxic to the cells, under the conditions assessed. Together, these results indicate the potential of ExT as a source of compounds that can modulate the neutrophil-mediated inflammatory diseases. (C) 2008 Elsevier Ltd. All rights reserved.

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Phospholipase A(2) (PLA(2), EC 3.1.1.4), a major component of snake venoms, specifically catalyzes the hydrolysis of fatty acid ester bonds at position 2 of 1,2-diacyl-sn-3-phosphoglycerides in the presence of calcium. This article reports the purification and biochemical/functional characterization of BmooTX-I, a new myotoxic acidic phospholipase A(2) from Bothrops moojeni snake venom. The purification of the enzyme was carried out through three chromatographic steps (ion-exchange on DEAE-Sepharose, molecular exclusion on Sephadex G-75 and hydrophobic chromatography on Phenyl-Sepharose). BmooTX-I was found to be a single-chain protein of 15,000 Da and pI 4.2. The N-terminal sequence revealed a high homology with other acidic Asp49 PLA(2)S from Bothrops snake venoms. It displayed a high phospholipase activity and platelet aggregation inhibition induced by collagen or ADP. Edema and myotoxicity in vivo were also induced by BmooTX-I. Analysis of myotoxic activity was carried out by optical and ultrastructural microscopy, demonstrating high levels of leukocytary infiltrate. Previous treatment of BmooTX-1 with BPB reduced its enzymatic and myotoxic activities, as well as the effect on platelet aggregation. Acidic myotoxic PLA(2)S from Bothrops snake venoms have been little explored and the knowledge of its structural and functional features will be able to contribute for a better understanding of their action mechanism regarding enzymatic and toxic activities. (C) 2008 Elsevier Ltd. All rights reserved.

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Scorpion stings are a public health problem in Brazil, with most incidents involving the species Tityus serrulatus. Some T serrulatus toxins may act as immunogens for the production of a specific anti-venom, but many of the component toxins remain poorly characterized. Here, we describe the immunological characteristics of the toxin Ts1 (also known as TsVII and Ts-gamma) and evaluate production of neutralizing antibodies against the crude venom of T serrulatus. Recombinant Ts1 with one copy (Ts1((1))) or two copies in tandem (Ts1((2))) was expressed in BL21 (DE3) cells. Rabbits and mice were immunized with the recombinant proteins (inclusion bodies) and then tested for production of neutralizing antibodies. Neutralization assays showed that anti-Ts1((1)) and anti-Ts1((2)) protected animals challenged with T serrulatus crude venom and native Ts1 Thus, Ts1 could be used in a mixed ""cocktail"" of immunogens for T serrulatus anti-venom production. (C) 2008 Elsevier Ltd. All rights reserved.

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Guttiferone-A (GA) is a natural occurring polyisoprenylated benzophenone with cytotoxic action in vitro and anti-tumor action in rodent models. We addressed a potential involvement of mitochondria in GA toxicity (1-25 mu M) toward cancer cells by employing both hepatic carcinoma (HepG2) cells and succinate-energized mitochondria, isolated from rat liver. In HepG2 cells GA decreased viability, dissipated mitochondrial membrane potential, depleted ATP and increased reactive oxygen species (ROS) levels. In isolated rat-liver mitochondria GA promoted membrane fluidity increase, cyclosporine A/EGTA-insensitive membrane permeabilization, uncoupling (membrane potential dissipation/state 4 respiration rate increase), Ca(2+) efflux, ATP depletion, NAD(P)H depletion/oxidation and ROS levels increase. All effects in cells, except mitochondrial membrane potential dissipation, as well as NADPH depletion/oxidation and permeabilization in isolated mitochondria, were partly prevented by the a NAD(P)H regenerating substrate isocitrate. The results suggest the following sequence of events: 1) GA interaction with mitochondrial membrane promoting its permeabilization; 2) mitochondrial membrane potential dissipation; 3) NAD(P)H oxidation/depletion due to inability of membrane potential-sensitive NADP(+) transhydrogenase of sustaining its reduced state; 4) ROS accumulation inside mitochondria and cells; 5) additional mitochondrial membrane permeabilization due to ROS; and 6) ATP depletion. These GA actions are potentially implicated in the well-documented anti-cancer property of GA/structure related compounds. (C) 2011 Elsevier Inc. All rights reserved.

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Nemorosone, a natural-occurring polycyclic polyprenylated acylphloroglucinol, has received increasing attention due to its strong in vitro anti-cancer action. Here, we have demonstrated the toxic effect of nemorosone (1-25 mu M) on HepG2 cells by means of the MTT assay, as well as early mitochondrial membrane potential dissipation and ATP depletion in this cancer cell line. In mitochondria isolated from rat liver, nemorosone (50-500 nM) displayed a protonophoric uncoupling activity, showing potency comparable to the classic protonophore, carbonyl cyanide m-chlorophenyl hydrazone (CCCP). Nemorosone enhanced the succinate-supported state 4 respiration rate, dissipated mitochondrial membrane potential, released Ca(2+) from Ca(2+)-loaded mitochondria, decreased Ca(2+) uptake and depleted ATP. The protonophoric property of nemorosone was attested by the induction of mitochondrial swelling in hyposmotic K(+)-acetate medium in the presence of valinomycin. In addition, uncoupling concentrations of nemorosone in the presence of Ca(2+) plus ruthenium red induced the mitochondrial permeability transition process. Therefore, nemorosone is a new potent protonophoric mitochondrial uncoupler and this property is potentially involved in its toxicity on cancer cells. (C) 2010 Elsevier B.V. and Mitochondria Research Society. All rights reserved.

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Objectives In the present study we investigated the anti nociceptive, anti-inflammatory and antipyretic effects of 7-hydroxycoumarin (7-HC) in animal models. Methods The effects of oral 7-HC were tested against acetic acid-induced writhing, formalin test, tail flick test, complete Freund`s adjuvant (CFA)-induced hypemociception, carrageenan-induced paw oedema, lipopolysaccharide-induced fever and the rota rod test. Key findings 7-HC (3-60 mg/kg) produced a dose-related antinociception against acetic acid-induced writhing in mice and in the formalin test. In contrast, treatment with 7-HC did not prevent thermal nociception in the tail flick test. A single treatment with 7-HC, 60 mg/kg, produced a long-lasting antinociceptive effect against CFA-induced hypernociception, a chronic inflammatory pain stimulus. Notably, at 60 mg/kg per day over 4 days the administration of 7-HC produced a continuous antinociceptive effect against CFA-induced hypernociception. 7-HC (30-120 mg/kg) produced anti-inflammatory and antipyretic effects against carrageenan-induced inflammation and lipopolysaccharide-induced fever, respectively. Moreover, 7-HC was found to be safe with respect to ulcer induction. In the rota rod test, 7-HC-treated mice did not show any motor performance alterations. Conclusions The prolonged antinociceptive and anti-inflammatory effects of 7-HC, in association with its low ulcerogenic activity, indicate that this molecule might be a good candidate for development of new drugs for the control of chronic inflammatory pain and fever.

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We describe herein an evaluation of the trypanocidal effect of eight piperamides (1-8) isolated from Piper tuberculatum bearing dihydropyridone, piperidine, and isobutyl moieties against epimastigote forms of Trypanosoma cruzi, the causative agent of Chagas` disease. Based on such results, three hydrogenated and two hydrolyzed derivatives (10-14) were prepared and evaluated as well. The dihydropyridone amides (1-3) displayed higher anti-trypanosomal activity. The (Z)-piplartine (1) showed higher activity with a 50% inhibition concentration (IC(50)) value of 10.5 mu M, almost four times more potent than the positive control, benznidazole (IC(50) = 42.7 mu M), and should be further evaluated as a suitable hit for the design of new antiprotozoal agents.

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In this study, fluid precursor formulations for subcutaneous injection and in situ formation of hexagonal phase gels upon water absorption were developed as a strategy to sustain the release of naltrexone, a drug used for treatment of drug addiction. Precursor formulations were obtained by combining BRIJ 97 with propylene glycol (PG, 5-70%, w/w). To study the phase behavior of these formulations, water was added at 10-90% (w/w), and the resulting systems were characterized by polarized light microscopy. Two precursor formulations containing BRIJ:PG at 95:5 (w/w, referred to as BRIJ-95) and at 80:20 (w/w, referred to as BRIJ-80) were chosen. Naltrexone was dissolved at 1% or suspended at 5% (w/w). Precursor formulations were transformed into hexagonal phases when water content exceeded 20%. Water uptake followed second-order kinetics, and after 2-4 h all precursor formulations were transformed into hexagonal phases. Drug release was prolonged by the precursor formulations (compared to a drug solution in PBS), and followed pseudo-first order kinetics regardless of naltrexone concentration. The release from BRIJ-80 was significantly higher than that from BRIJ-95 after 48 h. The relative safety of the precursor formulations was assessed in cultured fibroblasts. Even though BRIJ-95 was more cytotoxic than BRIJ-80, both precursor formulations were significantly less cytotoxic than sodium lauryl sulfate (considered moderate-to-severe irritant) at the same concentration (up to 50 mu g/mL). These results suggest the potential of BRIJ-based precursor formulations for sustained naltrexone release. (C) 2011 Elsevier By. All rights reserved.

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In addition to known heliangolides, a new eudesmanolide was isolated from the leaf rinse extract of Viguiera robusta (Asteraceae). Structural elucidation was based oil spectral analysis. It is the first report on eudesmanolides in members of the subgenus Calanticaria of Viguiera. In this work, the main isolated compound, the furanoheliangolide budlein A, besides its previously, reported in vitro and in vivo anti-inflammatory activities, inhibited human neutrophil elastase release. The inhibition was at the concentration of (16.83 +/- 1.96) mu M for formylated bacterial tripeptide (fMLP) stimulation and (11.84 +/- 1.62) mu M for platelet aggregation factor (PAF) stimulation, being slightly less active than the reference drug parthenolide. The results are important to demonstrate the potential anti-inflammatory activities of sesquiterpene lactones and corroborate the previous studies using other targets.