Bothrops jararaca Peptide with Anti-Hypertensive Action Normalizes Endothelium Dysfunction Involved in Physiopathology of Preeclampsia

Preeclampsia, a pregnancy-specific syndrome characterized by hypertension, proteinuria and edema, is a major cause of fetal and maternal morbidity and mortality especially in developing countries. Bj-PRO-10c, a proline-rich peptide isolated from Bothrops jararaca venom, has been attributed with potent anti-hypertensive effects. Recently, we have shown that Bj-PRO-10c-induced anti-hypertensive actions involved NO production in spontaneous hypertensive rats. Using in vitro studies we now show that Bj-PRO-10c was able to increase NO production in human umbilical vein endothelial cells from hypertensive pregnant women (HUVEC-PE) to levels observed in HUVEC of normotensive women. Moreover, in the presence of the peptide, eNOS expression as well as argininosuccinate synthase activity, the key rate-limiting enzyme of the citrulline-NO cycle, were enhanced. In addition, excessive superoxide production due to NO deficiency, one of the major deleterious effects of the disease, was inhibited by Bj-PRO-10c. Bj-PRO-10c induced intracellular calcium fluxes in both, HUVEC-PE and HUVEC, which, however, led to activation of eNOS expression only in HUVEC-PE. Since Bj-PRO-10c promoted biological effects in HUVEC from patients suffering from the disorder and not in normotensive pregnant women, we hypothesize that Bj-PRO-10c induces its anti-hypertensive effect in mothers with preeclampsia. Such properties may initiate the development of novel therapeutics for treating preeclampsia.

Influences of sex and age on biological rhythms of serum lipids and lipoproteins

Background: Few studies have evaluated seasonal variations of biochemical parameters routinely analyzed in clinical laboratories. Rhythmic patterns for lipids and lipoproteins have been demonstrated and have been the object of research, mainly because of their demonstrated association with coronary artery disease. This study evaluated the occurrence of biological rhythms on serum lipids and lipoproteins and the effects of sex and age on the rhythms in a Brazilian hospital outpatient population. Methods: Retrospective laboratory study was carried out to evaluate the results of total cholesterol (TC), HDL-cholesterol (HDL-C), LDL-cholesterol (LDL-C) and triglycerides (TG), from individuals registered at a university referral hospital over 8years. The studied population was composed of individuals of both sexes and all ages totaling 38,579 participants and 301,934 measurements. Statistical analyses were carried out using the SAS program and the temporal analysis used the Cosinor method. Results: TG rhythm was present only in females. All other parameters were equally rhythmic in both sexes. Regarding age, HDL-C presented rhythms in all age groups, but TC and LDL-C showed seasonality only for those > 13years, TG did not present rhythms in all age groups. Conclusion: Effects of sex and age on biological rhythms detected in TC, LDL-C and HDL-C should be considered a significant cause of pre-analytical variation in these laboratory tests. (C) 2009 Elsevier B.V. All rights reserved.

Cardiac anti-remodelling effect of aerobic training is associated with a reduction in the calcineurin/NFAT signalling pathway in heart failure mice

Cardiomyocyte hypertrophy occurs in response to a variety of physiological and pathological stimuli. While pathological hypertrophy in heart failure is usually coupled with depressed contractile function, physiological hypertrophy associates with increased contractility. In the present study, we explored whether 8 weeks of moderate intensity exercise training would lead to a cardiac anti-remodelling effect in an experimental model of heart failure associated with a deactivation of a pathological (calcineurin/NFAT, CaMKII/HDAC) or activation of a physiological (Akt-mTOR) hypertrophy signalling pathway. The cardiac dysfunction, exercise intolerance, left ventricle dilatation, increased heart weight and cardiomyocyte hypertrophy from mice lacking alpha(2A) and alpha(2C) adrenoceptors (alpha(2A)/alpha(2C)ARKO mice) were associated with sympathetic hyperactivity induced heart failure. The relative contribution of Ca(2+)-calmodulin high-affinity (calcineurin/NFAT) and low-affinity (CaMKII/HDAC) targets to pathological hypertrophy of alpha(2A)/alpha(2C)ARKO mice was verified. While nuclear calcineurin B, NFATc3 and GATA-4 translocation were significantly increased in alpha(2A)/alpha(2C)ARKO mice, no changes were observed in CaMKII/HDAC activation. As expected, cyclosporine treatment decreased nuclear translocation of calcineurin/NFAT in alpha(2A)/alpha(2C)ARKO mice, which was associated with improved ventricular function and a pronounced anti-remodelling effect. The Akt/mTOR signalling pathway was not activated in alpha(2A)/alpha(2C)ARKO mice. Exercise training improved cardiac function and exercise capacity in alpha(2A)/alpha(2C)ARKO mice and decreased heart weight and cardiomyocyte width paralleled by diminished nuclear NFATc3 and GATA-4 translocation as well as GATA-4 expression levels. When combined, these findings support the notion that deactivation of calcineurin/NFAT pathway-induced pathological hypertrophy is a preferential mechanism by which exercise training leads to the cardiac anti-remodelling effect in heart failure.

Power imbalance application region method for distributed synchronous generator anti-islanding protection design and evaluation

This paper presents a novel graphical approach to adjust and evaluate frequency-based relays employed in anti-islanding protection schemes of distributed synchronous generators, in order to meet the anti-islanding and abnormal frequency variation requirements, simultaneously. The proposed method defines a region in the power mismatch space, inside which the relay non-detection zone should be located, if the above-mentioned requirements must be met. Such region is called power imbalance application region. Results show that this method can help protection engineers to adjust frequency-based relays to improve the anti-islanding capability and to minimize false operation occurrences, keeping the abnormal frequency variation utility requirements satisfied. Moreover, the proposed method can be employed to coordinate different types of frequency-based relays, aiming at improving overall performance of the distributed generator frequency protection scheme. (C) 2011 Elsevier B.V. All rights reserved.

Citric acid as anti-hydration additive for magnesia containing refractory castables

Magnesia hydration is a key concern in refractory castable processing. The volumetric expansion that follows this reaction can result in cracks or even explosion during the first heating-up. Citric acid (CA) and other chelants can significantly reduce MgO hydration rate in aqueous suspensions by forming an insoluble magnesium citrate protective coating on the magnesia particles` surface. In the present work, the performance of CA as an anti-hydration additive in refractory castables was evaluated by hydration tests, mechanical strength and apparent volumetric expansion (AVE) measurements and thermogravimetry. The results attained have shown that CA effectiveness depends strongly on the amount added and by the interaction with other raw materials in the composition, in particular calcium aluminate cement. (C) 2011 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

Climate as the most important factor determining anti-fungal biocide performance in paint films

The effect of Pigment Volume Content (PVC) on fungal growth on acrylic paint formulations with and without biocide, exposed to weathering in three different climatic regions in Brazil for four years, was studied Latex paints. with PVC of 30%, 35% and 50%, were applied to autoclaved aerated concrete blocks pre-covered with acrylic sealer and acrylic plaster They were exposed to equatorial, tropical and temperate climates in north, south-east, and south Brazil Cladosporium was the most abundant fungal genus detected in the biofilm on the surfaces of all paint formulations at all sites after four years Heaviest fungal colonization occurred in the tropical south-east and lightest in the temperate south of the country, but more phototrophs, principally cyanobacteria, were detected in the equatorial region PVC and presence of biocides were shown to be of less importance than environmental conditions (irradiance, humidity and temperature) for biofilm formation and consequent discolouration These results have important implications for testing of paint formulations (C) 2010 Elsevier B V All rights reserved

a-SiC : H anti-resonant layer ARROW waveguides

Over the last decades, anti-resonant reflecting optical waveguides (ARROW) have been used in different integrated optics applications. In this type of waveguide, light confinement is partially achieved through an anti-resonant reflection. In this work, the simulation, fabrication and characterization of ARROW waveguides using dielectric films deposited by a plasma-enhanced chemical vapor deposition (PECVD) technique, at low temperatures(similar to 300 degrees C), are presented. Silicon oxynitride (SiO(x)N(y)) films were used as core and second cladding layers and amorphous hydrogenated silicon carbide(a-SiC:H) films as first cladding layer. Furthermore, numerical simulations were performed using homemade routines based on two computational methods: the transfer matrix method (TMM) for the determination of the optimum thickness of the Fabry-Perot layers; and the non-uniform finite difference method (NU-FDM) for 2D design and determination of the maximum width that yields single-mode operation. The utilization of a silicon carbide anti-resonant layer resulted in low optical attenuations, which is due to the high refractive index difference between the core and this layer. Finally, for comparison purposes, optical waveguides using titanium oxide (TiO(2)) as the first ARROW layer were also fabricated and characterized.

Brassinosteroids interact negatively with jasmonates in the formation of anti-herbivory traits in tomato

Given the susceptibility of tomato plants to pests, the aim of the present study was to understand how hormones are involved in the formation of tomato natural defences against insect herbivory. Tomato hormone mutants, previously introgressed into the same genetic background of reference, were screened for alterations in trichome densities and allelochemical content. Ethylene, gibberellin, and auxin mutants indirectly showed alteration in trichome density, through effects on epidermal cell area. However, brassinosteroids (BRs) and jasmonates (JAs) directly affected trichome density and allelochemical content, and in an opposite fashion. The BR-deficient mutant dpy showed enhanced pubescence, zingiberene biosynthesis, and proteinase inhibitor expression; the opposite was observed for the JA-insensitive jai1-1 mutant. The dpyxjai1-1 double mutant showed that jai1-1 is epistatic to dpy, indicating that BR acts upstream of the JA signalling pathway. Herbivory tests with the poliphagous insect Spodoptera frugiperda and the tomato pest Tuta absoluta clearly confirmed the importance of the JA-BR interaction in defence against herbivory. The study underscores the importance of hormonal interactions on relevant agricultural traits and raises a novel biological mechanism in tomato that may differ from the BR and JA interaction already suggested for Arabidopsis.

Immunological responses and cytokine gene expression analysis to Cooperia punctata infections in resistant and susceptible Nelore cattle

Cellular and humoral immune response, as well as cytokine gene expression, was assessed in Nelore cattle with different degrees of resistance to Cooperia punctata natural infection. One hundred cattle (male, weaned, 11-12 months old), kept together on pasture, were evaluated. Faecal and blood samples were collected for parasitological and immunological assays. Based on nematode faecal egg counts (FEC) and worm burden, the seven most resistant and the eight most susceptible animals were selected. Tissue samples of the small intestine were collected for histological quantification of inflammatory cells and analysis of cytokine gene expression (IL-2, IL-4, IL-8, IL-1 2p35, IL-13, TNF-alpha, IFN-gamma, MCP-1, MCP-2, and MUC- 1) using real-time RT-PCR. Mucus samples were also collected for IgA levels determination. Serum IgG1 mean levels against C. punctata antigens were higher in the resistant group, but significant differences between groups were only observed 14 days after the beginning of the experiment against infective larvae (1-3) and 14 and 84 days against adult antigens. The resistant group also presented higher IgA levels against C. punctata (L3 and adult) antigens with significant difference 14 days after the beginning of the trial (P < 0.05). In the small-intestine mucosa, levels of IgA anti-L3 and anti-adult C. punctata were higher in the resistant group, compared with the susceptible group (P < 0.05). Gene expression of both T(H)2 cytokines (IL-4 and IL-13) in the resistant group and T(H)1 cytokines (IL-2, IL-1 2p35, IFN-gamma and MCP-1) in the susceptible group was up-regulated. Such results suggested that immune response to C. punctata was probably mediated by TH2 cytokines in the resistant group and by T(H)1 cytokines in the susceptible group. (C) 2008 Elsevier B.V. All rights reserved.

Effect of Brazil nut supplementation on the blood levels of selenium and glutathione peroxidase in hemodialysis patients

Objective: In patients who have undergone hemodialysis, large amounts of reactive oxygen species (ROS) are produced and, at higher concentrations, ROS are thought to be involved in the pathogenesis of cardiovascular disease. It has been proposed that selenium (Se) may exert an anti-atherogenic influence by reducing oxidative stress. The richest known food source of selenium is the Brazil nut (Bertholletia excelsa, family Lecythidaceae), found in the Amazon region. We evaluated the effect of Brazil nut supplementation on blood levels of Se and glutathione peroxidase (GSH-Px) activity in patients on hemodialysis. Methods: A total of 81 patients on hemodialysis (52.0 +/- 15.2 y old, average time on dialysis 82.3 +/- 91.4 mo, body mass index 24.9 +/- 4.4 kg/m(2)) from the RenalCor and RenalVida Clinics in Rio de Janeiro, Brazil, were studied. All patients received one nut (around 5 g, averaging 58.1 mu g Se/g) a day for 3 mo. The Se concentrations in the nuts and in plasma and erythrocytes were determined by atomic absorption spectrophotometry with hydride generation (Hitachi, Z-500). GSH-Px levels were measured using Randox commercial kits. Results: Plasma Se (18.8 +/- 17.4 mu g/L) and erythrocyte (72.4 +/- 37.9 mg/L) levels were below the normal, range before nut supplementation. After supplementation, the plasma level increased to 104.0 +/- 65.0 mu g/L and erythrocytes to 244.1 +/- 119.5 mg/L (P<0.0001). The activity of GSH-Px also increased after supplementation, from 46.6 +/- 14.9 to 55.9 +/- 23.6 U/g of hemoglobin (P<0.0001). Before supplementation, 11% of patients had GSH-Px activity below the normal range (27.5-73.6 U/g of hemoglobin). After supplementation, all patients showed GSH-Px activity within the normal range. Conclusion: The data revealed that the investigated patients presented Se deficiency and that the consumption of only one Brazil nut a day (5 g) during 3 mo was effective to increase the Se concentration and GSH-Px activity in these patients, thus improving their antioxidant status. (C) 2010 Elsevier Inc. All rights reserved.

Increased electronegative LDL and decreased antibodies against electronegative LDL levels correlate with inflammatory markers and adhesion molecules in hemodialysed patients

Background: Chronic Kidney Disease (CKD) patients present high levels of electronegative LDL (LDL) that can modulate the expression of molecules involved in inflammation and it is closely linked to atherosclerosis. We investigated the association between LDL(-) and inflammatory markers in patients undergoing hemodialysis (HD). Methods: Forty-seven HD patients from a private clinic in Rio de Janeiro, Brazil were studied and compared with 20 age matched healthy individuals. Serum LDL(-) and anti-LDL(-) autoantibody levels were measured by ELISA; TNF-alpha, IL-6, VCAM-1 and ICAM-1 were determined by a multiplex assay kit. Results: HD patients presented higher IL-6 and TNF-alpha concentrations (4.1 +/- 1.6 and 5.5 +/- 2.1 pg/ml, respectively) than healthy subjects (2.6 +/- 0.2 and 2.4 +/- 1.1 pg/ml, respectively) (p = 0.0001). In addition, they presented higher VCAM-1 and ICAM-1 levels and, LDL(-) concentrations were also increased (0.18 +/- 0.12 U/I) when compared to healthy individuals (0.10 +/- 0.08 U/I) (p<0.02). In contrast, the anti-LDL(-) autoantibody levels were lower in HD patients (0.02 +/- 0.01 mg/l) than in healthy subjects (0.05 +/- 0.03 mg/l) (p<0.001). There was a positive correlation between LDL(-) and IL-6 (r = 0.25, p = 0.004) and ICAM-1 (r = 0.36; p = 0.003). There was also a negative correlation between anti-LDL(-) autoantibodies and TNF-alpha (r = -0.37; p = 0.003) and VCAM-1 (r = -0.50; p = 0.0001). Conclusions: The association between LDL(-) and inflammation and the lower levels of anti-LDL(-) autoantibodies are important risk factors related to atherosclerosis in CKD. (C) 2011 Published by Elsevier B.V.

Is serum amyloid A an endogenous TLR4 agonist?

Serum amyloid A (SAA), a classical acute-phase protein, is produced predominantly by hepatocytes in response to injury, infection, and inflammation. It has been shown that SAA primes leukocytes and induces the expression and release of proinflammatory cytokines. Here, we report that SAA induces NO production by murine peritoneal macrophages. Using specific inhibitors, we showed that NO production was dependent on inducible NO synthase thorough the activation of ERK1/2 and p38 MAPKs. Moreover, SAA activity was decreased after proteolysis but not with polymyxin B, a lipid A antagonist. Finally, we found that NO production was dependent on functional TLR4, a receptor complex associated with innate immunity. Macrophages from C3H/HeJ and C57BL/10ScCr mice lacking a functional TLR4 did not respond to SAA stimulation. In conclusion, our study makes a novel observation that SAA might be an endogenous agonist for the TLR4 complex on macrophages. The contribution of this finding in amplifying innate immunity during the inflammatory process is discussed.

Synthetic peptides as an antigenic base in an ELISA for laboratory diagnosts of schistosomiasis mansoni

A pool of five synthetic peptides was used as an antigenic base in an ELISA (ELISA-Pp) for laboratory diagnosis of Schistosoma mansoni. Serum samples were obtained from individuals with acute (n = 23) and chronic (n = 30) schistosomiasis, with other parasitoses (n = 39) or without parasitic infections (n = 100). ELISA-Pp was compared with other immunoenzymatic methods for detection of IgM (IgM-ELISA) or IgG (IgG-ELISA) as well as an immunofluorescence test for detection of IgM antibodies (IgM-IFT). The sensitivity and specificity of ELISA-Pp was 86.8% and 94.2% when tested on the schistosomiasis group and the non-schistosomiasis group, respectively. Comparison of ELISA-Pp with other serological methods resulted in K concordance indices varying from 0.59 to 0.75. Evaluation of anti-peptide IgG antibodies showed higher Levels in patients with acute compared with chronic schistosomiasis (P = 0.001). ELISA-Pp showed satisfactory sensitivity and high specificity and may constitute a potentially useful method for laboratory diagnosis of schistosomiasis mansoni. (c) 2007 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.

Lopap: A non-inflammatory and cytoprotective molecule in neutrophils and endothelial cells

Lopap (Lonomia obliqua prothrombin activator protease) is a member of the lipocalin family isolated from the extract of L obliqua bristles. Lopap displays serine protease-like activities, including coagulation disturbance, cytokine secretion and antiapoptotic activity in human cultured endothelial cells. Here, we have investigated the effects of the recombinant protein (rLopap) on the inflammatory and apoptotic processes of neutrophils and endothelial cells from male Wistar rats. We found that rLopap did not induce in vivo leukocyte-endothelial interactions in the microvasculature, initial steps of leukocyte recruitment during inflammation. Incubation of rLopap with neutrophils or endothelial cells prevented apoptosis evoked by serum deprivation and induced nitric oxide (NO) production in both cell types, and increased the expression of ICAM-1 by endothelial cells. Simultaneous incubation of endothelial cells or neutrophils with rLopap and N(omega)-nitro-L-arginine methyl ester (L-NAME), a non-specific inhibitor of NO synthases, inhibited NO production and impaired the protection on apoptosis. Differently, incubation of endothelial cells with monoclonal antibody anti ICAM-1 did not change the protection on apoptosis evoked by rLopap. Together, these results indicate that rLopap does not display inflammatory properties in vivo but inhibits apoptosis of neutrophils and endothelial cells depending, at least in part, on NO production. (C) 2009 Elsevier Ltd. All rights reserved.

Serum amyloid A induces CCL20 secretion in mononuclear cells through MAPK (p38 and ERK1/2) signaling pathways

Although the serum levels of SAA had been reported to be upregulated during inflammatory/infectious process, the role of this acute-phase protein has not been completely elucidated. In previous studies, we demonstrated that SAA stimulated the production of TNF-alpha, IL-1 beta, IL-8, NO, and ROS by neutrophils and/or mononuclear cells. Herein we demonstrate that SAA induces the expression and release of CCL20 from Cultured human blood mononuclear cells. We also focus on the signaling pathways triggered by SAA. in THP-1 cells SAA promotes phosphorylation of p38 and ERK1/2. Furthermore, the addition of SB203580 (p38 inhibitor) and PD98059 (ERK 1/2 inhibitor) inhibits the expression and release of CCL20 in mononuclear cells treated with SAA. Our results point to SAA as an important link of innate to adaptive immunity, once it might act on the recruitment of mononuclear cells. (C) 2008 Elsevier B.V. All rights reserved.