Single-center, double-blind, randomized, placebo-controlled pilot study of Canoxidin® for prevention of catheter encrustation in patients with indwelling catheters.

INTRODUCTION AND OBJECTIVES: Long-term use of an indwelling catheter is associated with complications such as catheter encrustation and infection. Canoxidin® is a novel oral treatment that can potentially prevent catheter encrustation, as it contains a urine acidifier and a combination of two crystallization inhibitors. This study aimed to evaluate the effects of Canoxidin® on catheter encrustation in patients with indwelling Foley catheters. PATIENTS AND METHODS: This was a single-center, double-blind, randomized, placebo-controlled study. Neuro-urology patients aged ≥18 years with an indwelling catheter (urethral or suprapubic) were randomized to treatment consisting of either Canoxidin® or placebo for one month. Foley catheters (two per patient, one before treatment and one after treatment) were removed for analysis of the presence and degree of encrustation. RESULTS: A total of 40 patients were enrolled and randomized, 28 of whom had analyzable catheters (13 assigned to Canoxidin® and 15 assigned to placebo). The patients had a mean age of 51.8 years, and eight (28.6%) were female. Two patients (13.3%) in the placebo group and eight patients (61.5%) in the Canoxidin® group experienced an improvement (less encrustation). There was a significant association between Canoxidin® and improvement (odds ratio: 10.4, 95% confidence interval: 1.6 to 66.9, P = 0.016). No adverse effects attributable to the treatment were reported. CONCLUSIONS: The overall rate of catheter encrustation was high among those with indwelling Foley catheters. One-month treatment with Canoxidin® reduced the formation of these encrustations, with an excellent short-term safety profile.

Proteome-wide modulation of S-nitrosylation in Trypanosoma cruzi trypomastigotes upon interaction with the host extracellular matrix.

Trypanosoma cruzi trypomastigotes adhere to extracellular matrix (ECM) to invade mammalian host cells regulating intracellular signaling pathways. Herein, resin-assisted enrichment of thiols combined with mass spectrometry were employed to map site-specific S-nitrosylated (SNO) proteins from T. cruzi trypomastigotes incubated (MTy) or not (Ty) with ECM. We confirmed the reduction of S-nitrosylation upon incubation with ECM, associated with a rewiring of the subcellular distribution and intracellular signaling pathways. Forty, 248 and 85 SNO-peptides were identified only in MTy, Ty or in both conditions, respectively. SNO proteins were enriched in ribosome, transport, carbohydrate and lipid metabolisms. Nitrosylation of histones H2B and H3 on Cys64 and Cys126, respectively, is described. Protein-protein interaction networks revealed ribosomal proteins, proteins involved in carbon and fatty acid metabolism to be among the enriched protein complexes. Kinases, phosphatases and enzymes involved in the metabolism of carbohydrates, lipids and amino acids were identified as nitrosylated and phosphorylated, suggesting a post-translational modifications crosstalk. In silico mapping of nitric oxide synthase (NOS) genes, previously uncharacterized, matched to four putative T. cruzi proteins expressing C-terminal NOS domain. Our results provide the first site-specific characterization of S-nitrosylated proteins in T. cruzi and their modulation upon ECM incubation before infection of the mammalian hosts. SIGNIFICANCE: Protein S-nitrosylation represents a major molecular mechanism for signal transduction by nitric oxide. We present for the first time a proteomic profile of S-nitrosylated proteins from infective forms of T. cruzi, showing a decrease in SNO proteins after incubation of the parasite with the extracellular matrix, a necessary step for the parasite invasion of the host mammalian cells. We also show for the first time nitrosylation of H2B (Cys64) and H3 (Cys126) histones, sites not conserved in higher eukaryotic cells, and suggest that some specific histone isoforms are sensitive to NO signaling. S-nitrosylation in H2B and H3 histones are more abundant in MTy. Moreover, proteins involved in translation, glycolytic pathway and fatty acid metabolism are enriched in the present dataset. Comparison of the SNO proteome and the phosphoproteome, obtained previously under the same experimental conditions, show that most of the proteins sharing both modifications are involved in metabolic pathways, transport and ribosome function. The data suggest that both PTMs are involved in reprogramming the metabolism of T. cruzi in response to environmental changes. Although NO synthesis was detected in T. cruzi, the identification of NOS remains elusive. Analysis in silico showed two genes similar in domains to NADPH-dependent cytochrome-P450 reductase and two putative oxidoreductases, but no oxygenase domain of NOS was mapped in the T. cruzi genome. It is tempting to speculate that NO synthase-like from T. cruzi and its early NO-mediated pathways triggered in response to host interaction constitute potential diagnostic and therapeutic targets.

Where do we aspire to publish? A position paper on scientific communication in biochemistry and molecular biology.

The scientific publication landscape is changing quickly, with an enormous increase in options and models. Articles can be published in a complex variety of journals that differ in their presentation format (online-only or in-print), editorial organizations that maintain them (commercial and/or society-based), editorial handling (academic or professional editors), editorial board composition (academic or professional), payment options to cover editorial costs (open access or pay-to-read), indexation, visibility, branding, and other aspects. Additionally, online submissions of non-revised versions of manuscripts prior to seeking publication in a peer-reviewed journal (a practice known as pre-printing) are a growing trend in biological sciences. In this changing landscape, researchers in biochemistry and molecular biology must re-think their priorities in terms of scientific output dissemination. The evaluation processes and institutional funding for scientific publications should also be revised accordingly. This article presents the results of discussions within the Department of Biochemistry, University of São Paulo, on this subject.

Where do we aspire to publish? A position paper on scientific communication in biochemistry and molecular biology

The scientific publication landscape is changing quickly, with an enormous increase in options and models. Articles can be published in a complex variety of journals that differ in their presentation format (online-only or in-print), editorial organizations that maintain them (commercial and/or society-based), editorial handling (academic or professional editors), editorial board composition (academic or professional), payment options to cover editorial costs (open access or pay-to-read), indexation, visibility, branding, and other aspects. Additionally, online submissions of non-revised versions of manuscripts prior to seeking publication in a peer-reviewed journal (a practice known as pre-printing) are a growing trend in biological sciences. In this changing landscape, researchers in biochemistry and molecular biology must re-think their priorities in terms of scientific output dissemination. The evaluation processes and institutional funding for scientific publications should also be revised accordingly. This article presents the results of discussions within the Department of Biochemistry, University of São Paulo, on this subject.

Antibacterial effect and biocompatibility of a novel nanostructured ZnO-coated gutta-percha cone for improved endodontic treatment.

This work explored a novel approach to enhance the antibacterial activity of commercial Gutta-percha (GP) cones, the most commonly used core filling materials used in endodontic treatment. The reported procedure involved an argon (Ar) plasma treatment (PT) of the GP cone surface, followed by the deposition of a ZnO thin film by magnetron sputtering. The resulting surfaces were evaluated for surface topography, antibacterial activity against Enterococcus faecalis and Staphylococcus aureus, and cytocompatibility with human osteoblastic cells. GP cones treated with NaOCl, a routine chair-side protocol, were also tested as reference. The deposition of a ZnO film on pristine GP cones increased its antibacterial activity. Cones pre-treated with Ar-plasma (PT) and coated with the ZnO thin film presented significantly higher antibacterial activity than that observed on the pristine and, also, compared to the ZnO coated cones. The higher antibacterial activity of PT + ZnO cones appears related to the major effects induced by the PT pre-treatment on the cone surface endowing the deposited ZnO film with a homogeneous nanostructured topography that greatly improved surface reactivity. The modified GP cones maintained an appropriate cytocompatibility with human cells. This novel approach provides ready-to-use cones with enhanced antibacterial activity, improving a strict asepsis protocol during endodontic treatment and preventing secondary endodontic infections.

Assessing epidemiology of leprosy and socio-economic distribution of cases.

Leprosy still represents a serious health problem in a number of countries, including Brazil. Although leprosy has been associated with poverty for a long time, it is still difficult to accurately define this relationship. Here, we evaluated in an endemic municipality the progress from 1995 to 2015 of epidemiological indicators to establish if there were any strong associations between social indicators and the occurrence of leprosy. An ecological study was conducted using the SINAN database (Brazilian leprosy-national notifiable diseases information system) in combination with georeferencing of leprosy cases. The georeferencing used the ArcGis programme and occurrence of cases was evaluated in relation to the Health Vulnerability Index (HVI), an indicator that categorises socio-economic and sanitation factors. The data identified a marked decrease in the overall prevalence of leprosy, a reduction in the new case-detection rate and a reduction in the number of cases with grade 2 disabilities (albeit with transient peaks in 2007 and 2015). Logistic regression analysis showed association of detection rates with elevated HVI. Thus, while the epidemiological indicators point to the elimination of leprosy, there is evidence of hidden cases and an association between higher rates of leprosy detection and greater social vulnerability remain.

Post-Exercise Neurovascular Control in Chronic Heart Failure Patients.

It remains unknown whether or not a reduction in muscle sympathetic nerve activity in heart failure patients is associated over time with the effects of long- or short-term repeated exercise. 10 chronic heart failure patients, age 49±3 years old, functional class I-III NYHA, ejection fraction <40% were randomly submitted to either an acute bout of moderate continuous exercise OR high-intensity interval exercise. Muscle sympathetic nerve activity (microneurography) and forearm blood flow (venous occlusion plethysmography) were evaluated pre- and post-exercise sessions. The moderate exercise consisted of cycle exercise at an intensity corresponding to anaerobic threshold. The interval exercise consisted of a 2-min cycle exercise at intensity corresponding to anaerobic threshold, followed by a 1-min exercise set at respiratory compensation point. Exercise capacity was evaluated by cardiopulmonary exercise test. The caloric expenditure in both sessions was 100 kcal. Baseline muscle sympathetic nerve activity and forearm blood flow levels were not different between sessions. Moderate or high-intensity exercise caused no significant changes in muscle sympathetic nerve activity and forearm blood flow. These findings suggest that the reduction in muscle sympathetic nerve activity and the increase in forearm blood flow provoked by exercise training in chronic heart failure patients are due to cumulative effects over time.

Zika virus infections imported from Brazil to Portugal, 2015.

Zika virus is an emerging arbovirus transmitted by Aedes sp. mosquitoes like the Dengue and Chikungunya viruses. Zika virus was until recently considered a mild pathogenic mosquito-borne flavivirus with very few reported benign human infections. In 2007, an epidemic in Micronesia initiated the turnover in the epidemiological history of Zika virus and more recently, the potential association with congenital microcephaly cases in Brazil 2015, still under investigation, led the World Health Organization (WHO) to declare a Public Health Emergency of International Concern on February 1, 2016. Here, we present the clinical and laboratory aspects related to the first four imported human cases of Zika virus in Portugal from Brazil, and alert, regarding the high level of traveling between Portugal and Brazil, and the ongoing expansion of this virus in the Americas, for the threat for Zika virus introduction in Europe and the possible introduction to Madeira Island where Aedes aegypti is present.

Prokineticin receptor identified by phage display is an entry receptor for Trypanosoma cruzi into mammalian cells.

Trypanosoma cruzi trypomastigotes invade a great variety of mammalian cells, with several molecules being implicated in this complex event. Herein, the sequence GGIALAG present in prokineticin-2 receptor (PKR2), selected by phage display technology, is described as a new T. cruzi receptor for the Tc85 group of glycoproteins belonging to the gp85/TS superfamily and involved in cellular invasion of mammalian hosts. This finding is confirmed by the inhibitory activity of MCF10-A (human mammary) cell invasion by T. cruzi either by anti-PKR2 antibodies (77%) or GGIALAG-synthetic peptide (42%). Furthermore, interference RNA (iRNA) inhibition of PKR2 expression in MCF10-A cells reduces T. cruzi invasion by 50%. The binding site of Tc85 to PKR2 was localized at the C-terminal end of the molecule, upstream of the conserved FLY sequence, previously implicated in parasite cell invasion. PKR2, a receptor formed by seven membrane-spanning α-helical segments, is mainly present in the central nervous system, peripheral organs, and mature blood cells. Due to its wide distribution, PKR2 could be a suitable receptor for T. cruzi natural infection, contributing to the parasite dissemination throughout the mammalian organism. These findings augment the number and diversity of possible in vivo receptors for T. cruzi and reassure the multiplicity of Tc85 binding sites to mammalian hosts.

Contraceptive choices pre and post pregnancy in adolescence.

STUDY OBJECTIVE: The main aim of this study is to evaluate the impact of adolescent pregnancy in the future contraceptive choices. A secondary aim is to verify whether these choices differ from those made after an abortion. DESIGN: Retrospective study. SETTING: Adolescent Unit of a tertiary care center. PARTICIPANTS: 212 pregnant teenagers. INTERVENTIONS: Medical records review. MAIN OUTCOME MEASURES: Intended pregnancy rate and contraceptive methods used before and after pregnancy. For contraceptive choices after pregnancy we considered: Group 1--teenagers who continued their pregnancy to delivery (n = 106) and Group 2--the same number of adolescents who chose to terminate their pregnancy. RESULTS: The intended pregnancy rate was 14.2%. Prior to a pregnancy continued to delivery, the most widely used contraceptive method was the male condom (50.9%), followed by oral combined contraceptives (28.3%); 18.9% of adolescents were not using any contraceptive method. After pregnancy, contraceptive implant was chosen by 70.8% of subjects (P < .001) and the oral combined contraceptives remained the second most frequent option (17.9%, P = .058). Comparing these results with Group 2, we found that the outcome of the pregnancy was the main factor in the choices that were made. Thus, after a pregnancy continued to delivery, adolescents prefer the use of LARC [78.4% vs 40.5%, OR: 5,958 - 95% (2.914-12.181), P < .001)], especially contraceptive implants [70.8% vs 38.7%, OR: 4.371 - 95% (2.224-8.591), P < .001], to oral combined contraceptives [17.9% vs 57.5%, OR: 0.118 - 95% CI (0.054-0.258), P < .001]. CONCLUSION: Adolescent pregnancy and its outcome constitute a factor of change in future contraceptive choice.

How gamma-rays and electron-beam irradiation would affect the antimicrobial activity of differently processed wild mushroom extracts?

AIMS: The effects of irradiation (gamma-rays and electron-beams), up to 10 kGy, in the antimicrobial activity of mushroom species (Boletus edulis, Hydnum repandum, Macrolepiota procera and Russula delica) differently processed (fresh, dried, freeze) were evaluated. METHODS AND RESULTS: Clinical isolates with different resistance profiles from hospitalized patients in Local Health Unit of Mirandela, Northeast of Portugal, were used as target micro-organisms. The mushrooms antimicrobial activity did not suffer significant changes that might compromise applying irradiation as a possible mushroom conservation technology. CONCLUSIONS: Two kGy dose (independently of using gamma-rays or electron-beams) seemed to be the most suitable choice to irradiate mushrooms. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides important results in antimicrobial activity of extracts prepared from irradiated mushroom species.

Estudo etnofarmacológico em entorno de floresta urbana como subsídio para a implantação da Fitoterapia no Sistema Único de Saúde / Ethnopharmacological study surrounding urban forest as a resource for the implementation of herbal medicine in the National Health System

RESUMO O estudo etnofarmacológico pode ser definido como exploração científica interdisciplinar dos agentes biologicamente ativos, tradicionalmente utilizados por populações humanas e que fazem parte de um acervo de conhecimento compartilhado. Desta forma o presente estudo teve como objetivo o estudo etnofarmacológico de plantas medicinais, no entorno de floresta urbana na Reserva Biológica Poço D’Anta em Juiz de Fora/MG visando a implantação da fitoterapia no Sistema Único de Saúde. Para este, realizou-se levantamento com três diferentes amostras: profissionais de saúde, domicílios em geral e especialistas locais. Quanto aos profissionais de saúde, pôde-se constatar que nenhum entrevistado soube conceituar o termo “Fitoterápico” e que não conheciam as políticas vigentes. Constatou-se que há aceitabilidade da implantação de Fitoterapia na saúde pública, porém, o conhecimento do tema é limitado. A partir das entrevistas nos domicílios em geral e com os especialistas locais, selecionou-se um total de 20 espécies botânicas para análise estatística e confirmação farmacológica. Esses resultados possibilitaram confrontar o conhecimento cultural com científico, com base em 14 espécies que poderiam ser cultivadas em horto na Reserva Biologica Poço D´Anta, com base em suas relevâncias locais. Os resultados obtidos podem subsidiar a aproximação do saber popular em relação ao científico, servindo de base para manutenção e fomento da implantação da Fitoterapia no sistema único de saúde.

ABSTRACT The ethnopharmacological study can be defined as an interdisciplinary scientific exploration of biologically active agents, traditionally used by human populations and part of a shared body of knowledge. Thus, the current study focused on the ethnopharmacological research of medicinal plants, in the surroundings of the urban forest in the Biological Reserve PoçoD’Anta in Juiz de Fora / MG, aiming on the implementation of the herbal medicine in the Public Health System. For this purpose, a survey was held with three different groups: health professionals, members of the community and local experts.Concerning the health professionals, it could be verified that none of the participants were able to explain the term Phytotherapic and neither they had knowledge about the relevant and applicable policies.The acceptability for the implantation of Phytotherapy for public health use was observed, but the knowledge about this subject is limited. From the interviews with members of the community and local experts, a total of 20 plant species were selected for a statistical analysis and pharmacological confirmation. These results made possible to compare the cultural knowledge with the scientific one, defining 14 species that could be grown in the garden of the Biological Reserve Poço D’Anta, based on their local relevance. The results can support the approximation of the popular knowledge with the scientific one, providing a basis for the maintenance and promotion of the Phytotherapy in the Public Health System.

Sympatric occurrence of Culex pipiens (Diptera, Culicidae) biotypes pipiens, molestus and their hybrids in Portugal, Western Europe: feeding patterns and habitat determinants.

Culex (Culex) pipiens (Diptera: Culicidae) has two recognized biotypes, pipiens and molestus, which differ in physiology and behaviour; this difference may influence vectorial capacity for West Nile virus (WNV). Our goal was first to determine the presence of Cx. pipiens populations in 31 locations in Portugal and to subsequently analyse their host-feeding preferences and habitat determinants. Molecular identification of Cx. pipiens forms and their hybrids was performed in 97 females; bloodmeal sources were identified in 59 engorged specimens. Overall, 61.9% of specimens were identified as Cx. pipiens f. pipiens, 20.6% as Cx. pipiens f. molestus, and 17.5% as hybrid forms. Culex pipiens f. pipiens fed preferentially on birds, and Cx. pipiens f. molestus on humans. Hybrid forms fed mostly on birds, but human bloodmeals were common. With reference to habitat, Cx. pipiens f. pipiens and hybrid forms were positively correlated with peri-urban habitats. Our results confirm the sympatric presence of different Cx. pipiens biotypes in 14 of the 31 locations studied. Peri-urban areas were a common habitat of all biotypes and may represent zones of hybridization. The feeding preferences and sympatric distribution of the Cx. pipiens biotypes observed in Portugal favour the epizootic circulation of WNV and the occurrence of disease outbreaks of WNV.

Wild mushroom extracts potentiate the action of standard antibiotics against multiresistant bacteria.

AIMS: The main objective of this study was to evaluate the capacity of wild mushroom extracts to potentiate the action of standard antibiotics, through synergisms that allow a decrease in their therapeutic doses and ultimately contribute to the reduction of resistances. METHODS AND RESULTS: Wild mushroom extracts were applied to different multiresistant micro-organisms (Escherichia coli, extended-spectrum beta-lactamase-producing (ESBL) E. coli and methicillin-resistant Staphylococcus aureus (MRSA), combined with commercial antibiotics (penicillin, ampicillin, amoxicillin/clavulanic acid, cefoxitin, ciprofloxacin, cotrimoxazol, levofloxacin). Microdilution method was used to determine minimum inhibitory concentrations (MICs). The results obtained showed higher synergistic effects against MRSA than against E. coli. Mycena rosea and Fistulina hepatica were the best extracts for synergistic effects against MRSA. The efficiency of Russula delica extract against E. coli 1 (resistant to ampicillin, ciprofloxacin and trimethoprim/sulfasoxazole) and E. coli 2 (resistant to amoxicillin/clavulanic acid and ampicillin) was higher than that of Leucopaxillus giganteus extract; nevertheless, the latter extract exhibited better synergistic effects against ESBL E. coli. CONCLUSIONS: This study shows that, similarly to plants, some mushroom extracts can potentiate the action of antibiotics extensively used in clinical practice for Gram-positive or Gram-negative bacteria, with positive action even against multiresistant bacteria. SIGNIFICANCE AND IMPACT OF THE STUDY: Mushroom extracts could decrease therapeutic doses of standard antibiotics and reduce micro-organism's resistance to those drugs.

Impaired post exercise heart rate recovery in anabolic steroid users.

Previous study showed that muscle sympathetic nerve activity (MSNA) was augmented in anabolic steroids users (AASU). In the present study, we tested the hypothesis that the heart rate (HR) responses after maximal exercise testing would be reduced in AASU. 10 male AASU and 10 AAS nonusers (AASNU) were studied. Cardiopulmonary exercise was performed to assess the functional capacity and heart rate recovery. MSNA was recorded directly from the peroneal nerve by microneurography technique. Peak oxygen consumption (VO2) was lower in AASU compared to AASNU (43.66±2.24 vs. 52.70±1.68 ml/kg/min, P=0.005). HR recovery (HRR) at first and second minute was lower in AASU than AASNU (21±2 vs. 27±2 bpm, P=0.02 and 37±4 vs. 45±2 bpm, P=0.05, respectively). MSNA was higher in AASU than AASNU (29±3 vs. 20±1 bursts/min, P=0.01). Further analysis showed a correlation between HRR and MSNA (r=- 0.64, P=0.02), HRR at first minute and peak VO2 (r=0.70, P=0.01) and HRR at second minute and peak VO2 (r=0.62, P=0.02). The exacerbated sympathetic outflow associated with a lower parasympathetic activation after maximal exercise, which impairs heart rate recovery, strengthens the idea of autonomic imbalance in AASU.

Antimicrobial activity of phenolic compounds identified in wild mushrooms, SAR analysis and docking studies.

AIM AND METHODS: Although the antimicrobial activity of extracts from several mushroom species has been reported, studies with the individual compounds present in that extracts are scarce. Herein, the antimicrobial activity of different phenolic compounds identified and quantified in mushroom species from all over the world was evaluated. Furthermore, a structure-activity relationship (SAR) analysis and molecular docking studies were performed, in order to provide insights into the mechanism of action of potential antimicrobial drugs for resistant micro-organisms. RESULTS: 2,4-Dihydroxybenzoic and protocatechuic acids were the phenolic compounds with higher activity against the majority of Gram-negative and Gram-positive bacteria. Furthermore, phenolic compounds inhibited more MRSA than methicillin-susceptible Staphylococcus aureus. MRSA was inhibited by 2,4-dihydroxybenzoic, vanillic, syringic (MICs = 0.5 mg ml(-1) ) and p-coumaric (MIC = 1 mg ml(-1) ) acids, while these compounds at the same concentrations had no inhibitory effects against methicillin-susceptible Staph. aureus. CONCLUSIONS: The presence of carboxylic acid (COOH), two hydroxyl (OH) groups in para and ortho positions of the benzene ring and also a methoxyl (OCH3 ) group in the meta position seems to be important for anti-MRSA activity. SIGNIFICANCE AND IMPACT OF THE STUDY: Phenolic compounds could be used as antimicrobial agents, namely against some micro-organisms resistant to commercial antibiotics.

Clinical presentation and laboratory findings for the first autochthonous cases of dengue fever in Madeira island, Portugal, October 2012.

An outbreak of dengue fever in Madeira island was reported in 2012. Clinical and laboratory findings of the first two laboratory-confirmed autochthonous cases are reported. Both cases had fever (≥38 °C) and petechial rash. Symptoms also included myalgia, asthenia, nausea, vomiting, anorexia, diffuse abdominal pain, and diarrhoea. The two cases were confirmed by serology and one tested positive for a dengue viral sequence. Dengue virus serotype DEN-1 was identified with probable Central or South American origin.

Release of the cytosolic tryparedoxin peroxidase into the incubation medium and a different profile of cytosolic and mitochondrial peroxiredoxin expression in H2O2-treated Trypanosoma cruzi tissue culture-derived trypomastigotes.

Trypanosoma cruzi antioxidant enzymes are among the factors that guarantee parasite survival and maintain infection, enabling T. cruzi to cope with oxidative stress. Herein, the expression of cytosolic (TcCPx) and mitochondrial (TcMPx) tryparedoxin peroxidases was evaluated in tissue culture-derived trypomastigotes upon incubation with different concentrations of H(2)O(2). TcCPx expression slightly increased (5.4%) in cells submitted to 10 µM H(2)O(2) treatment when compared to the control, but decreased when higher H(2)O(2) concentrations (20-50 µM) were employed. Under these conditions, TcMPx expression increased (∼53%) with 10 µM-treatment compared to the control, followed by a reduction that reached ∼46% of the control when using the highest concentration tested. Interestingly, in the supernatant of the incubations, TcCPx, but not TcMPx, was detected, and its levels increased concomitantly with its decreased expression in the intracellular compartment. Our data show that peroxiredoxins in the tissue culture-derived trypomastigote can be modulated under oxidative stress and are present in higher amounts when compared to the epimastigote stage of T. cruzi. Additionally, due to the different expression patterns observed upon H(2)O(2)-treatment, each peroxiredoxin may play a distinct role in protecting the parasite under oxidative stress conditions.

Avaliação do efeito do alho (Allium sativum L. ) sobre o colesterol plasmático em coelhos com hipercolesterolemia induzida / Evaluation of garlic (Allium sativum L. ) effects on the serum cholesterol of rabbits with induced hypercholesterolemia

A utilização de plantas no tratamento de doenças ou como meio curativo é uma tradição popular e altamente difundida, sendo que muitos trabalhos abordam as propriedades terapêuticas e farmacológicas do alho na redução das hiperlipidemias. O objetivo deste estudo foi investigar a influência do extrato aquoso (E.A.) do alho (Allium sativum L.) no tratamento do colesterol plasmático em coelhos com hipercolesterolemia experimental. Os animais foram divididos em G1 (grupo controle) e G2 (grupo tratado com alho). O experimento foi desenvolvido em três fases: na 1ª fase os animais receberam dieta comercial de coelhos para avaliar o nível basal de colesterol nos animais; na 2ªfase, todos os animais passaram a receber dieta suplementada com gema de ovo, até o final do experimento, para desenvolver hipercolesterolemia, e; na 3ª fase os animais do grupo G2 receberam o tratamento com E. A. de alho. O colesterol na 1ª fase foi de 39,94 ± 9,57 mg dL-1. Na 2ª fase houve elevação significativa (p<0,05) no nível de colesterol plasmático nos dois grupos -acima de 100 mg dL-1. Com relação ao tratamento, o alho não promoveu redução no colesterol plasmático dos coelhos, contrapondo os dados da literatura.

The use of plants to treat diseases or even to cure them is a high diffused popular tradition, and several studies discuss the therapeutic and pharmacological properties of garlic in the reduction of hyperlipidaemias. The objective of the present study was to investigate the influence of the aqueous extract of garlic (Allium sativum) to treat the serum cholesterol of rabbits with experimental hypercholesterolemia. The animals were divided into G1 (control group) and G2 (group treated with garlic). The experiment was developed according to 3 phases: during the 1st phase, all animals were provided with a regular diet to evaluate the basal cholesterol; during the 2nd phase, all animals received a supplemented diet until the end of the experiment, in order to develop hypercholesterolemia and, in the 3rd phase, the animals on G2 received the garlic treatment. The cholesterol registered on the 1st phase was 39.94 ± 9.57 mg dL-1. On the 2nd phase, there was an increase on the serum cholesterol level in both groups - higher than 100 mg dL-1. Concerning the treatment, the garlic did not reduce the serum cholesterol in rabbits.

Mechanisms of blunted muscle vasodilation during peripheral chemoreceptor stimulation in heart failure patients.

We described recently that systemic hypoxia provokes vasoconstriction in heart failure (HF) patients. We hypothesized that either the exaggerated muscle sympathetic nerve activity and/or endothelial dysfunction mediate the blunted vasodilatation during hypoxia in HF patients. Twenty-seven HF patients and 23 age-matched controls were studied. Muscle sympathetic nerve activity was assessed by microneurography and forearm blood flow (FBF) by venous occlusion plethysmography. Peripheral chemoreflex control was evaluated through the inhaling of a hypoxic gas mixture (10% O(2) and 90% N(2)). Basal muscle sympathetic nerve activity was greater and basal FBF was lower in HF patients versus controls. During hypoxia, muscle sympathetic nerve activity responses were greater in HF patients, and forearm vasodilatation in HF was blunted versus controls. Phentolamine increased FBF responses in both groups, but the increase was lower in HF patients. Phentolamine and N(G)-monomethyl-l-arginine infusion did not change FBF responses in HF but markedly blunted the vasodilatation in controls. FBF responses to hypoxia in the presence of vitamin C were unchanged and remained lower in HF patients versus controls. In conclusion, muscle vasoconstriction in response to hypoxia in HF patients is attributed to exaggerated reflex sympathetic nerve activation and blunted endothelial function (NO activity). We were unable to identify a role for oxidative stress in these studies.