Antioxidant treatment reduces matrix metalloproteinase-2-induced vascular changes in renovascular hypertension

Mounting evidence indicates that structural and functional vascular changes associated with two-kidney, one-clip (2K-1C) hypertension result, at least in part, from altered activity of matrix metalloproteinases (MMPs). Because MMPs are upregulated by increased formation of reactive oxygen species (ROS), we hypothesized that antioxidant approaches could attenuate the increases in MMP-2 expression/activity and the vascular dysfunction and remodeling associated with 2K-1C hypertension. Sham-operated or 2K-1C hypertensive rats were treated with tempol 18 mg/kg/day or apocyanin 25 mg/kg/day (or vehicle). Systolic blood pressure was monitored weekly. After 8 weeks of treatment, aortic rings were isolated to assess endothelium-dependent and -independent relaxation. Quantitative morphometry of structural changes in the aortic wall was studied in hematoxylin/eosin sections. Aortic and systemic ROS levels were measured using dihydroethidine and thiobarbituric acid-reactive substances, respectively. Aortic MMP-2 levels and activity were determined by gelatin and in situ zymography, fluorimetry, and immunohistochemistry. Tempol and apocyanin attenuated 2K-1C hypertension (181 +/- 20.8 and 192 +/- 17.6 mm Hg, respectively, versus 213 +/- 18 mm Hg in hypertensive controls; both p<0.05) and prevented the reduction in endothelium-dependent vasorelaxation found in 2K-1C rats. Tempol, but not apocyanin (p>0.05), prevented the vascular remodeling found in 2K-1C rats (all p<0.01). Tempol was more effective than apocyanin in attenuating hypertension-induced increases in oxidative stress (both p<0.05), MMP-2 levels, and MMP-2 activity in hypertensive rats (all p<0.05). Our results suggest that antioxidant approaches decrease MMP-2 upregulation and attenuate the vascular dysfunction and remodeling during 2K-1C hypertension. (C) 2009 Elsevier Inc. All rights reserved.

An unusual dimeric guaianolide with antiprotozoal activity and further sesquiterpene lactones from Eupatorium perfoliatum

The CH(2)Cl(2) extract of aerial parts of Eupatorium perfoliatum L. exhibits antiprotozoal activity under in vitro conditions, especially against Plasmodium falciparum (IC(50)=2.7 mu g/ml). The search for active compounds yielded seven sesquiterpene lactones: Four structurally similar guaianolides, one dimeric guaianolide, and two germacranolides. The guaianolides differ in the degree of oxidation at C-14, ranging from a hydroxyl group up to a free carboxylic acid. The dimeric guaianolide, structurally closely related to the monomers, displays an unusual type of interguaianolide linkage between C-14 and C-4. Except for the germacranolide euperfolitin, all STLs described here were hitherto unknown. Furthermore, the flavonoid aglycones eupafolin, hispidulin, patuletin, and kaempferol were identified in the extract, which, except for kaempferol, have not been described as constituents of E. perfoliatum before. The dimeric guaianolide was shown to be the most active constituent against Plasmodium falciparum (IC(50) = 2.0 mu M) and was less cytotoxic against rat skeletal myoblasts (IC(50) = 16.2 mu M, selectivity index of about 8). (C) 2011 Elsevier Ltd. All rights reserved.

Antimicrobial activity of the extract and isolated compounds from Baccharis dracunculifolia D. C. (Asteraceae)

Baccharis dracunculifolia D. C. (Asteraceae) is the most important plant source of the Brazilian green propolis. Since propolis is known for its antimicrobial activity, the aim of this work was to evaluate the showed that the leaves extract of B. dracunculifolia (BdE) presents antifungal and antibacterial activities, especially against Candida krusei and Cryptococcus neoformans, for which the BdE showed IC50 values of 65 mu g mL(-1) and 40 mu g mL(-1), respectively In comparison to the BdE, it was observed that the green propolis extract (GPE) showed better antimicrobial activity, displaying an IC50 value of 9 mu g mL(-1) against C krusei. Also, a phytochemical study of the BdE was carried out, affording the isolation of ursolic acid (1), 2 alpha-hydroxy-ursolic acid (2), isosakuranetin (3), aromadendrin-4`-methylether (4), baccharin (5), viscidone (6), hautriwaic acid lactone (7), and the clerodane diterpene 8. This is the first time that the presence of compounds 1, 2, and 8 in B. dracunculifolia has been reported. Among the isolated compounds, 1 and 2 showed antibacterial activity against methicillin-resistant Staphylococcus aureus, displaying IC50 values of 65 mu g mL(-1) and 40 mu g mL(-1), respectively. 3 was active against C neoformans, showing an IC50 value of 15 mu g mL(-1) and a MIC value of 40 mu g mL(-1), while compounds 4-8 were inactive against all tested microorganisms. The results showed that the BdE, similar to the GPE, displays antimicrobial activity, which may be related to the effect of several compounds present in the crude extract.

A common matrix metalloproteinase (MMP)-2 polymorphism affects plasma MMP-2 levels in subjects environmentally exposed to mercury

Mercury (Hg) exposure is associated with disease conditions, including cardiovascular problems. Although the mechanisms implicated in these complications have not been precisely defined yet, matrix metalloproteinases (MMPs) may be involved. The gene encoding MMP-2 presents genetic polymorphisms which affect the expression and activity level of this enzyme. A common polymorphism of MMP-2 gene is the C(-1306)T (rs 243865), which is known to disrupt a Sp1-type promoter site (CCACC box), thus leading to lower promoter activity associated with the T allele. This study aimed at examining how this polymorphism affects the circulating MMP-2 levels and its endogenous inhibitor, the tissue inhibitor of metalloproteinase-2 (TIMP-2) in 210 subjects environmentally exposed to Hg. Total blood and plasma Hg concentrations were determined by inductively coupled plasma-mass spectrometry (ICP-MS). MMP-2 and TIMP-2 concentrations were measured in plasma samples by gelatin zymography and ELISA, respectively. Genotypes for the C(-1306)T polymorphism were determined by Taqman (R) Allele Discrimination assay. We found a positive association (p = 0.0057) between plasma Hg concentrations and MMP-2/TIMP-2 (an index of net MMP-2 activity). The C(-1306)T polymorphism modified MMP-2 concentrations (p = 0.0465) and MMP-2/TIMP-2 ratio (p = 0.0060) in subjects exposed to Hg, with higher MMP-2 levels been found in subjects carrying the C allele. These findings suggest a significant interaction between the C(-1306)T polymorphism and Hg exposure, possibly increasing the risk of developing diseases in subjects with the C allele. (C) 2011 Elsevier B.V. All rights reserved.

A functional matrix metalloproteinase (MMP)-9 polymorphism modifies plasma MMP-9 levels in subjects environmentally exposed to mercury

Mercury (Hg) exposure causes health problems including cardiovascular diseases. Although precise mechanisms have not been precisely defined yet, matrix metalloproteinases (MMPs) may be involved. The gene encoding MMP-9 presents genetic polymorphisms which affect the expression and activity level of this enzyme. Two polymorphisms in the promoter region [C(-1562)T and (CA)(n)] are functionally relevant, and are implicated in several diseases. This study aimed at examining how these polymorphisms affect the circulating MMP-9 levels and its endogenous inhibitor, the tissue inhibitor of metalloproteinase-1 (TIMP-1) in 266 subjects environmentally exposed to Hg. Blood and plasma Hg concentrations were determined by inductively coupled plasma-mass spectrometry (ICP-MS). MMP-9 and TIMP-1 concentrations were measured in plasma samples by gelatin zymography and ELISA, respectively. Genotypes for the C(-1562)T and the microsatellite (CA)(n) polymorphisms were determined. We found a positive association (P<0.05) between plasma Hg concentrations and MMP-9/TIMP-1 ratio (an index of net MMP-9 activity). When the subjects were divided into tertiles with basis on their plasma Hg concentrations, we found that the (CA)(n) polymorphism modified MMP-9 concentrations and MMP-9/TIMP-1 ratio in subjects with the lowest Hg concentrations (first tertile), with the highest MMP-9 levels being found in subjects with genotypes including alleles with 21 or more CA repeats (H alleles) (P<0.05). Conversely, this polymorphism had no effects on subjects with intermediate or high plasma Hg levels (second and third tertiles, respectively). The C(-1562)T polymorphism had no effects on MMP-9 levels. These findings suggest a significant interaction between the (CA)(n) polymorphism and low levels of Hg exposure, possibly increasing the risk of developing diseases in subjects with H alleles. (c) 2010 Elsevier B.V. All rights reserved.

Mercury Exposure Increases Circulating Net Matrix Metalloproteinase (MMP)-2 and MMP-9 Activities

Mercury (Hg) exposure causes health problems that may result from increased oxidative stress and matrix metalloproteinase (MMP) levels. We investigated whether there is an association between the circulating levels of MMP-2, MMP-9, their endogenous inhibitors (the tissue inhibitors of metalloproteinases; TIMPs) and the circulating Hg levels in 159 subjects environmentally exposed to Hg. Blood and plasma Hg were determined by inductively coupled plasma-mass spectrometry (ICP-MS). MMP and TIMP concentrations were measured in plasma samples by gelatin zymography and ELISA respectively. Thiobarbituric acid-reactive species (TBARS) were measured in plasma to assess oxidative stress. Selenium (Se) levels were determined by ICP-MS because it is an antioxidant. The relations between bioindicators of Hg and the metalloproteinases levels were examined using multivariate regression models. While we found no relation between blood or plasma Hg and MMP-9, plasma Hg levels were negatively associated with TIMP-1 and TIMP-2 levels, and thereby with increasing MMP-9/TIMP-1 and MMP-2/TIMP-2 ratios, thus indicating a positive association between plasma Hg and circulating net MMP-9 and MMP-2 activities. These findings provide a new insight into the possible biological mechanisms of Hg toxicity, particularly in cardiovascular diseases.

Circulating matrix metalloproteinase-8 (MMP-8) and MMP-9 are increased in chronic periodontal disease and decrease after non-surgical periodontal therapy

Background: Periodontal disease shares risk factors with cardiovascular diseases and other systemic inflammatory diseases. The present study was designed to assess the circulating matrix metalloproteinases (MMPs) from chronic periodontal disease patients and, subsequently, after periodontal therapy. Methods: We compared the plasma concentrations of MMP-2. MMP-3, MMP-8, MMP-9, tissue inhibitor of metalloproteinase-1 (TIMP-1) and TIMP-2, and total gelatinolytic activity in patients with periodontal disease (n =28) with those of control subjects (n = 22) before and 3 months after non-surgical periodontal therapy. Results: Higher plasma MMP-3, MMP-8, and MMP-9 concentrations were found in periodontal disease patients compared with healthy controls (all P<0.05), whereas MMP-2, TIMP-1, and TIMP-2 levels were not different. Treatment decreased plasma MMP-8 and MMP-9 concentrations by 35% and 39%, respectively (both P<0.02), while no changes were found in controls. MMP-2, MMP-3, TIMP-1, and TIMP-2 remained unaltered in both groups. Plasma gelatinolytic activity was higher in periodontal disease patients compared with controls (P<0.001) and decreased after periodontal therapy (P<0.05). Conclusions: This study showed increased circulating MMP-8 and MMP-9 levels and proteolytic activity in periodontal disease patients that decrease after periodontal therapy. The effects of periodontal therapy suggest that it may attenuate inflammatory chronic diseases. (C) 2009 Published by Elsevier B.V.

Differences in both matrix metalloproteinase 9 concentration and zymographic profile between plasma and serum with clot activators are due to the presence of amorphous silica or silicate salts in blood collection devices

Matrix metalloproteinases (MMPs) are promising diagnostic tools, and blood sampling/handling alters MMP concentrations between plasma and serum and between serum with and without clot activators. To explain the higher MMP-9 expression in serum collected with clot accelerators relative to serum with no additives and to plasma, we analyzed the effects of increasing amounts of silica and silicates (components of clot activators) in,citrate plasma, serum, and huffy coats collected in both plastic and glass tubes from 50 healthy donors, and we analyzed the effects of silica and silicate on cultured leukemia cells. The levels of MMP-2 did not show significant changes between glass and plastic tubes, between serum and plasma, between serum with and without clot accelerators, or between silica and silicate treatments. No modification of MMP-9 expression was obtained by the addition of silica or silicate to previously separated plasma and serum. Increasing the amounts of nonsoluble silica and soluble silicate added to citrate and empty tubes prior to blood collection resulted in increasing levels of MMP-9 relative to citrate plasma and serum. Silica and silicate added to buffy coats and leukemia cells significantly induced MMP-9 release/secretion, demonstrating that both silica and silicate induce the release of pro- and complexed MMP-9 forms. We recommend limiting the misuse of serum and avoiding the interfering effects of clot activators. (c) 2007 Elsevier Inc. All rights reserved.

The game to play: expanding the co-opetition proposal through the strategic games matrix

Purpose - Using Brandenburger and Nalebuff`s 1995 co-opetition model as a reference, the purpose of this paper is to seek to develop a tool that, based on the tenets of classical game theory, would enable scholars and managers to identify which games may be played in response to the different conflict of interest situations faced by companies in their business environments. Design/methodology/approach - The literature on game theory and business strategy are reviewed and a conceptual model, the strategic games matrix (SGM), is developed. Two novel games are described and modeled. Findings - The co-opetition model is not sufficient to realistically represent most of the conflict of interest situations faced by companies. It seeks to address this problem through development of the SGM, which expands upon Brandenburger and Nalebuff`s model by providing a broader perspective, through incorporation of an additional dimension (power ratio between players) and three novel, respectively, (rival, individualistic, and associative). Practical implications - This proposed model, based on the concepts of game theory, should be used to train decision- and policy-makers to better understand, interpret and formulate conflict management strategies. Originality/value - A practical and original tool to use game models in conflict of interest situations is generated. Basic classical games, such as Nash, Stackelberg, Pareto, and Minimax, are mapped on the SGM to suggest in which situations they Could be useful. Two innovative games are described to fit four different types of conflict situations that so far have no corresponding game in the literature. A test application of the SGM to a classic Intel Corporation strategic management case, in the complex personal computer industry, shows that the proposed method is able to describe, to interpret, to analyze, and to prescribe optimal competitive and/or cooperative strategies for each conflict of interest situation.

Synthesis of homoallylic oxygenated alpha-methylene-gamma-butyrolactones: a model for preparing biologically active natural lactones

In this Letter we describe a 12% overall yield synthesis of a model for homoallylic oxygenated alpha-methylene-gamma-butyrolactones with relative stereochemistry defined by selective hydrogenation with Rh/Al(2)O(3). The synthesis was realized in 9 steps involving simple reactions. (C) 2008 Elsevier Ltd. All rights reserved.

Removal from the Membrane Affects the Interaction of Rat Osseous Plate Ecto-Nucleosidetriphosphate Diphosphohydrolase-1 with Substrates and Ions

We have characterized the kinetic properties of ectonucleoside triphosphate diphosphohydrolase 1 (E-NTPDase1) from rat osseous plate membranes. A novel finding of the present study is that the solubilized enzyme shows high- and low-affinity sites for the substrate in contrast with a single substrate site for the membrane-bound enzyme. In addition, contrary to the Michaelian chraracteristics of the membrane-bound enzyme, the site-site interactions after solubilization with 0.5% digitonin plus 0.1% lysolecithin resulted in a less active ectonucleoside triphosphate diphosphohydrolase, showing activity of about 398.3 nmol Pi min(-1) mg(-1). The solubilized enzyme has M(r) of 66-72 kDa, and its catalytic efficiency was significantly increased by magnesium and calcium ions; but the ATP/ADP activity ratio was always < 2.0. Partial purification and kinetic characterization of the rat osseous plate E-NTPDase1 in a solubilized form may lead to a better understanding of a possible function of the enzyme as a modulator of nucleotidase activity or purinergic signaling in matrix vesicle membranes. The simple procedure to obtain the enzyme in a solubilized form may also be attractive for comparative studies of particular features of the active sites from this and other ATPases.

Surface modification of metals by calcium carbonate thin films on a layer-by-layer polyelectrolyte matrix

A multilayer organic film containing poly(acrylic acid) and chitosan was fabricated on a metallic support by means of the layer-by-layer technique. This film was used as a template for calcium carbonate crystallization and presents two possible binding sites where the nucleation may be initiated, either calcium ions acting as counterions of the polyelectrolyte or those trapped in the template gel network formed by the polyelectrolyte chains. Calcium carbonate formation was carried out by carbon dioxide diffusion, where CO, was generated from ammonium carbonate decomposition. The CaCO3 nanocrystals obtained, formed a dense, homogeneous, and continuous film. Vaterite and calcite CaCO3 crystalline forms were detected. (c) 2007 Elsevier B.V All rights reserved.

Cerium-based phosphors: blue luminescent properties for applications in optical displays

In this paper, we describe the blue photoluminescence (PL) observed in the multi-component oxosalt phosphor GdVO(4)center dot Ce(3+). Different doping concentrations (0.25-1 mol%) and heat treatment (900-1100 degrees C) were used to evaluate which conditions would lead to the most suitable blue phosphor for optimal display performance. The cerium doping concentration influences the profile of the emission spectrum (broad peak at 412 nm under UV excitation at 330 nm), as reflected on the values of chromaticity coordinates. On the basis of luminescent properties, we can conclude that, among the phosphors prepared in this work the most adequate for a blue display is the one obtained via the combustion method using glycine as fuel, a 0.50 mol% cerium doping concentration, and heat treatment at 1000 degrees C.

Development of novel bioanodes for ethanol biofuel cell using PAMAM dendrimers as matrix for enzyme immobilization

This paper describes the preparation and application of a novel bioanode for use in ethanol/O(2) biofuel cells based upon immobilization of alcohol dehydrogenase (ADH) and polyamidoamine (PAMAM) dendrimers onto carbon cloth platforms. The power density measurements indicated a direct relationship between the amount of anchored ADH and the anode power values, which increased upon enzyme loading. The power density values ranged from 0.04 to 0.28 mW cm(-2), and the highest power density was achieved with the bioanode prepared with 28 U of ADH, which provided a power density of 0.28 mW cm(-2) at 0.3 V. The latter power output values were the maximum observed, even for higher enzyme concentrations. Stability of the bioanodes was quite satisfactory, since there was no appreciable reduction of enzymatic activity during the measurements. The method of bioanode preparation described here has proven to be very effective. The PAMAM dendrimer represents a friendly environment for the immobilization of enzymes, and it is stable and capable of generating high power density compared to other immobilization methods. (C) 2010 Elsevier B.V. All rights reserved.

Social Wasp Diversity (Vespidae, Polistinae) in a Forest Fragment in the Northeast of Sao Paulo State Sampled with Different Methodologies

Social wasp diversity in Semideciduous Seasonal Forests of the northeast of Sao Paulo State is poorly known, causing a lack of information on the diversity of these wasps from these areas which have been degraded. The objective of this work was to evaluate the social wasp (Vespidae, Polistinae) diversity in a Semideciduous Seasonal Forest of the northeast of Sao Paulo State and to compare three different kinds of sampling methodology. Surveys were conducted from August 2005 to September 2006 in the interior, edge and matrix of a Semideciduous Seasonal Forest fragment in Patrocinio Paulista city, Sao Paulo State. Three methodologies were used: 1. Active collection in flowers, 2. Searching for nests, 3. Active collection with attractive liquid. Thirty species of social wasps were collected in the fragment, but the diversity was highest in the edge. Active collection with attractive liquid was the most efficient methodology. Despite the high levels of deforestation, forest fragments in Sao Paulo State have a high diversity of social wasps, reinforcing the importance of their preservation.