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1.
Environ Res ; 251(Pt 1): 118549, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38412915

RESUMO

Antimicrobial Resistance (AMR) poses a global threat to both human health and environmental well-being. Our study delved into Costa Rican wildlife reserves, uncovering a substantial human impact on these ecosystems and underscoring the imperative to pinpoint AMR hotspots. Embracing a One Health perspective, we advocated for a comprehensive landscape analysis that intricately intertwined geographic, climatic, forest, and human factors. This study illuminated the link between laboratory results and observed patterns of antimicrobial use, thereby paving the way for sustainable solutions. Our innovative methodology involved deploying open-ended questions to explore antimicrobial usage across livestock activities, contributing to establishing a comprehensive methodology. Non-invasive sampling in wildlife emerged as a critical aspect, shedding light on areas contaminated by AMR. Feline species, positioned at the apex of the food chain, acted as sentinels for environmental health due to heightened exposure to improperly disposed waste. Regarding laboratory findings, each sample revealed the presence of at least one antimicrobial resistance gene (ARG). Notably, genes encoding resistance to tetracyclines dominated (94.9%), followed by beta-lactams (75.6%), sulfonamides (53.8%), aminoglycosides (51.3%), quinolones (44.9%), phenicols (25.6%), and macrolides (20.5%). Genes encoding polymyxins were not detected. Moreover, 66% of samples carried a multi-resistant microbiome, with 15% exhibiting resistance to three antimicrobial families and 51% to four. The absence of a correlation between forest coverage and ARG presence underscored the profound human impact on wildlife reserves, surpassing previous estimations. This environmental pressure could potentially modify microbiomes and resistomes in unknown ways. As not all antimicrobial families encoding ARGs were utilized by farmers, our next step involved evaluating other human activities to identify the primary sources of contamination. This comprehensive study contributed crucial insights into the intricate dynamics of AMR in natural ecosystems, paving the way for targeted interventions and sustainable coexistence.


Assuntos
Ecossistema , Animais , Costa Rica , Antibacterianos/farmacologia , Gatos , Monitoramento Ambiental/métodos , Farmacorresistência Bacteriana , Humanos
2.
Clin Neurophysiol ; 151: 28-40, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37146531

RESUMO

OBJECTIVE: This study aims 1) To analyse differences in resting-state electroencephalogram (rs-EEG) spectral features of Parkinson's Disease (PD) and healthy subjects (non-PD) using Functional Data Analysis (FDA) and 2) To explore, in four independent cohorts, the external validity and reproducibility of the findings using both epoch-to-epoch FDA and averaged-epochs approach. METHODS: We included 169 subjects (85 non-PD; 84 PD) from four centres. Rs-EEG signals were preprocessed with a combination of automated pipelines. Sensor-level relative power spectral density (PSD), dominant frequency (DF), and DF variability (DFV) features were extracted. Differences in each feature were compared between PD and non-PD on averaged epochs and using FDA to model the epoch-to-epoch change of each feature. RESULTS: For averaged epochs, significantly higher theta relative PSD in PD was found across all datasets. Also, higher pre-alpha relative PSD was observed in three of four datasets in PD patients. For FDA, similar findings were achieved in theta, but all datasets showed consistently significant posterior pre-alpha differences across multiple epochs. CONCLUSIONS: Increased generalised theta, with posterior pre-alpha relative PSD, was the most reproducible finding in PD. SIGNIFICANCE: Rs-EEG theta and pre-alpha findings are generalisable in PD. FDA constitutes a reliable and powerful tool to analyse epoch-to-epoch the rs-EEG.


Assuntos
Doença de Parkinson , Humanos , Doença de Parkinson/diagnóstico , Reprodutibilidade dos Testes , Eletroencefalografia
3.
Polymers (Basel) ; 13(23)2021 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-34883567

RESUMO

Polysaccharide coated nanoparticles represent a promising class of environmentally friendly latex to replace those stabilized by small toxic molecular surfactants. We report here an in situ formulation of free-surfactant core/shell nanoparticles latex consisting of dextran-based diblock amphiphilic copolymers. The synthesis of copolymers and the immediate latex formulation were performed directly in water using a photo-initiated reversible addition fragmentation chain transfer-mediated polymerization induced self-assembly strategy. A hydrophilic macromolecular chain transfer-bearing photosensitive thiocarbonylthio group (eDexCTA) was first prepared by a modification of the reducing chain end of dextran in two steps: (i) reductive amination by ethylenediamine in the presence of sodium cyanoborohydride, (ii) then introduction of CTA by amidation reaction. Latex nanoparticles were then formulated in situ by chain-extending eDexCTA using 2-hydroxypropyl methacrylate (HPMA) under 365 nm irradiation, leading to amphiphilic dextran-b-poly(2-hydroxypropyl methacrylate) diblock copolymers (DHX). Solid concentration (SC) and the average degree of polymerization - Xn-- of PHPMA block (X) were varied to investigate their impact on the size and the morphology of latex nanoparticles termed here SCDHX. Light scattering and transmission electron microscopy analysis revealed that SCDHX form exclusively spherical nano-objects. However, the size of nano-objects, ranging from 20 nm to 240 nm, increases according to PHPMA block length.

4.
Tissue Cell ; 69: 101483, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33444959

RESUMO

Diabetes mellitus (DM) is a metabolic disease associated with several intestinal disorders. S-methyl cysteine sulfoxide (SMCS) ​​is an amino acid present in Allium cepa L with hypoglycemic effects. However, the effects of SMCS on diabetic intestinal changes are unknown. Thus, we aimed to investigate the effects of SMCS on duodenal morphology and immunomodulatory markers in diabetic rats. Twenty-six rats were divided into three groups: control (C), diabetic (D) and diabetic +200 mg/kg SMCS (DSM). DM was induced by intraperitoneal injection of streptozotocin (50 mg/kg). After 30 days, duodenum samples were processed to assess histopathological and stereological alterations in volume, villus length, and immunohistochemical expression of NF-kB, IL-10, BCL-2, and caspase-3. SMCS reduced hyperglycemia and mitigated the increase in total reference volume of the duodenum, the absolute volume of the mucosa, and the length of the intestinal crypts in the DMS group when compared to D. IL-10 immunostaining was reduced in D when compared to C, while NF-kB was increased in D in comparison to the other groups. SMCS ​​supplementation could decrease the NF-kB immunostaining observed in D. Positive staining for BCL-2 and caspase-3 were not statistically different between groups. In summary, SMCS decreased hyperglycemia and mitigated the morphological changes of the duodenum in diabetic animals, and these beneficial effects can be partially explained by NF-kB modulation.


Assuntos
Cisteína/análogos & derivados , Diabetes Mellitus Experimental/patologia , Duodeno/patologia , Animais , Peso Corporal/efeitos dos fármacos , Cisteína/farmacologia , Ingestão de Líquidos/efeitos dos fármacos , Duodeno/efeitos dos fármacos , Comportamento Alimentar/efeitos dos fármacos , Masculino , Ratos Wistar
5.
Endosc Int Open ; 8(4): E525-E533, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32258375

RESUMO

Background and study aims A universal European training program in gastroenterology and hepatology is currently not available. The European Board of Gastroenterology and Hepatology (EBGH) has produced guidance regarding expected competencies for European gastroenterology trainees but it is unclear whether these have been incorporated in national curricula. The aim of this study was to provide an in-depth assessment of training and research opportunities, professional activities and of socioeconomic aspects of gastroenterology training across Europe through a web-based 90-point questionnaire. Materials and methods Physicians in their last year or who had recently finished their training, from 16 European countries, were invited to answer the questionnaire. Results A total of 144 physicians answered the survey. A minimum number of procedures is required before completing training in nine of 16 countries (56 %). Overall, European trainees dedicate a median of 12 months (IQR 6-25) of their training period to endoscopy and a median of 3 months (IQR 0-6) to ultrasound. Training in interventional endoscopy was not always exhaustive, as about 50 % of participants performed fewer of several interventional procedures than was recommended by EBGH, most participants did not perform endoscopic hemostasis or endoscopic mucosal resection, and nearly a half of participants had no access to pancreatobiliary endoscopy training. Finally, up to 13 % of residents complete their training without the supervision of a mentor. Conclusion In this large European survey, deep gaps and considerable differences in several gastroenterology training activities were found both among and within 16 European countries. Homogenization of educational programs and training opportunities across Europe is therefore necessary.

6.
Radiology ; 295(2): 307-313, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32125255

RESUMO

Background The risks associated with MRI in individuals who have implanted cardiac devices are thought to arise from the interaction between the implanted device and static, gradient, and radiofrequency magnetic fields. Purpose To determine the relationship between the peak whole-body averaged specific absorption rate (SAR) and change in magnetic field per unit time (dB/dt), maximum specific energy dose, imaging region, and implanted cardiac device characteristics and their function in patients undergoing MRI. Materials and Methods This prospective observational cohort study was conducted from October 16, 2003, to January 22, 2015 (https://ClinicalTrials.gov, NCT01130896). Any individual with an implanted cardiac device who was referred for MRI was included. Clinical MRI protocols without SAR restriction were used. Exclusion criteria were newly implanted leads, abandoned or epicardial leads, and dependence on a pacemaker with an implantable cardioverter defibrillator without asynchronous pacing capability. For each MRI pulse sequence, the calculated whole-body values for SAR, dB/dt, and scan duration were collected. Atrial and ventricular sensing, lead impedance, and capture threshold were evaluated before and immediately after (within 10 minutes) completion of each MRI examination. Generalized estimating equations with Gaussian family, identity link, and an exchangeable working correlation matrix were used for statistical analysis. Results A total of 2028 MRI examinations were performed in 1464 study participants with 2755 device leads (mean age, 67 years ± 15 [standard deviation]; 930 men [64%]). There was no evidence of an association between radiofrequency energy deposition, dB/dt, or scan duration and changes in device parameters. Thoracic MRI was associated with decreased battery voltage immediately after MRI (ß = -0.008 V, P < .001). Additionally, right ventricular (RV) lead length was associated with decreased RV sensing (ß = -0.012 mV, P = .05) and reduced RV capture threshold (ß = -0.002 V, P < .01) immediately after MRI. Conclusion There was no evidence of an association between MRI parameters that characterize patient exposure to radiofrequency energy and changes in device and lead parameters immediately after MRI. Nevertheless, device interrogation before and after MRI remains mandatory due to the potential for device reset and changes in lead or generator parameters. © RSNA, 2020 See also the editorial by Shellock in this issue.


Assuntos
Desfibriladores Implantáveis , Imageamento por Ressonância Magnética/métodos , Marca-Passo Artificial , Segurança do Paciente , Idoso , Protocolos Clínicos , Segurança de Equipamentos , Feminino , Humanos , Masculino , Estudos Prospectivos , Ondas de Rádio
7.
J Vet Med Sci ; 81(9): 1351-1354, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31366815

RESUMO

Intestinal smooth muscle hypertrophy and hyperplasia has been described in human and several mammal species. In birds, only one case of intestinal smooth muscle hyperplasia has been reported. This paper describes the anatomopathological and histological findings of three cases of intestinal smooth muscle hypertrophy/hyperplasia in two different avian species belonging to the family Gallinidae and Columbidae. Grossly, it involved all tracts of the small intestine. Histologically, hyperplasia involved the mucosal villi, muscularis mucosa and inner and outer layers of the tunica muscularis. Hypertrophy was apparently detected only in the inner circular muscle layer. Lack of submucosal plexuses was also observed in all three animals. The results confirm the remarkable histological difference between mammals and avian species and show as these pathological changes can occur in different species of birds.


Assuntos
Enteropatias/veterinária , Músculo Liso/patologia , Animais , Doenças das Aves/patologia , Galinhas , Columbidae , Feminino , Hiperplasia , Hipertrofia , Enteropatias/patologia , Intestino Delgado/patologia , Masculino
8.
Cien Saude Colet ; 23(6): 1763-1776, 2018 Jun.
Artigo em Português, Inglês | MEDLINE | ID: mdl-29972485

RESUMO

In recent years the international debate about universality in health has been marked by a polarization between ideas based on a universal system, and notions proposing universal health coverage. The concept of universal coverage has been disseminated by international organizations and has been incorporated into health system reforms in several developing countries, including some in Latin America. This article explores the assumptions and strategies related to the proposal of universal health coverage. Firstly, a comparison is provided of the models of universal health coverage and universal health systems. This is followed by a contextualization of the international debate, including examples of different health systems. Finally, the implications of the proposal of universal coverage for the right to health in Brazil are discussed. The analysis of different concepts of universality and the experiences of different countries shows that health insurance-based models, either social or private, are not as satisfactory as public, universal health systems. Greater understanding about ongoing international projects is essential in order to identify the possibilities represented by the consolidation of the Unified Health System (SUS) in Brazil, as well as the risks of dismantling the SUS.


Nos últimos anos, acirrou-se o debate internacional sobre diferentes concepções de universalidade em saúde, polarizado nas propostas de sistema universal versus cobertura universal em saúde. A concepção de cobertura universal tem sido difundida por organizações internacionais e incorporada às reformas dos sistemas de saúde de alguns países em desenvolvimento, inclusive na América Latina. O artigo explora os pressupostos e as estratégias relacionados à proposta de cobertura universal de saúde. Inicialmente contrastam-se as concepções de universalidade nos modelos de cobertura universal e de sistemas universais de saúde. A seguir, contextualiza-se o debate internacional, incluindo exemplos de diferentes sistemas de saúde. Por fim, discutem-se as implicações da concepção de cobertura universal para o direito à saúde no Brasil. A análise das diferentes concepções de universalidade e das experiências de países evidenciam que arranjos de seguros (privados ou sociais) não superam as fortalezas de sistemas públicos universais de saúde. A compreensão dos projetos em disputa no cenário internacional é fundamental para identificar possibilidades e ameaças à consolidação do Sistema Único de Saúde no Brasil.


Assuntos
Seguro Saúde/organização & administração , Programas Nacionais de Saúde/organização & administração , Cobertura Universal do Seguro de Saúde , Brasil , Países em Desenvolvimento , Reforma dos Serviços de Saúde , Humanos , América Latina
9.
Ciênc. Saúde Colet. (Impr.) ; 23(6): 1763-1776, jun. 2018. tab
Artigo em Português | LILACS | ID: biblio-952653

RESUMO

Resumo Nos últimos anos, acirrou-se o debate internacional sobre diferentes concepções de universalidade em saúde, polarizado nas propostas de sistema universal versus cobertura universal em saúde. A concepção de cobertura universal tem sido difundida por organizações internacionais e incorporada às reformas dos sistemas de saúde de alguns países em desenvolvimento, inclusive na América Latina. O artigo explora os pressupostos e as estratégias relacionados à proposta de cobertura universal de saúde. Inicialmente contrastam-se as concepções de universalidade nos modelos de cobertura universal e de sistemas universais de saúde. A seguir, contextualiza-se o debate internacional, incluindo exemplos de diferentes sistemas de saúde. Por fim, discutem-se as implicações da concepção de cobertura universal para o direito à saúde no Brasil. A análise das diferentes concepções de universalidade e das experiências de países evidenciam que arranjos de seguros (privados ou sociais) não superam as fortalezas de sistemas públicos universais de saúde. A compreensão dos projetos em disputa no cenário internacional é fundamental para identificar possibilidades e ameaças à consolidação do Sistema Único de Saúde no Brasil.


Abstract In recent years the international debate about universality in health has been marked by a polarization between ideas based on a universal system, and notions proposing universal health coverage. The concept of universal coverage has been disseminated by international organizations and has been incorporated into health system reforms in several developing countries, including some in Latin America. This article explores the assumptions and strategies related to the proposal of universal health coverage. Firstly, a comparison is provided of the models of universal health coverage and universal health systems. This is followed by a contextualization of the international debate, including examples of different health systems. Finally, the implications of the proposal of universal coverage for the right to health in Brazil are discussed. The analysis of different concepts of universality and the experiences of different countries shows that health insurance-based models, either social or private, are not as satisfactory as public, universal health systems. Greater understanding about ongoing international projects is essential in order to identify the possibilities represented by the consolidation of the Unified Health System (SUS) in Brazil, as well as the risks of dismantling the SUS.


Assuntos
Humanos , Cobertura Universal do Seguro de Saúde , Seguro Saúde/organização & administração , Programas Nacionais de Saúde/organização & administração , Brasil , Reforma dos Serviços de Saúde , Países em Desenvolvimento , América Latina
10.
United European Gastroenterol J ; 5(5): 750-755, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28815040

RESUMO

One of the aims of the Young Talent Group (YTG) is to make United European Gastroenterology (UEG) more attractive for young fellows interested in gastroenterology, and to involve them actively in UEG activities, by collaborating with young GI sections (YGIS) across Europe. Therefore, the YTG launched a survey to collect up-to-date information on YGISs belonging to UEG National Societies. The Friends of YTG were chosen as the target population and received a web-based questionnaire concerning their personal information, the structure of YGIS in their respective country, the YGIS' support mechanisms for young trainees, and ideas on how to improve them. Overall, 24 of 29 Friends answered the survey (83%). Among the Societies surveyed, only half have a young section. Typically, YGIS are supported, but not influenced, by National Societies through several initiatives. Results of the survey suggest that a lack of funding, of harmonised education, and of active roles available within National Societies, were the concerns most prevalent among young fellows. Our survey shows that the development of YGIS is being hindered by organisational, financial, and political issues. The YTG believes that a close collaboration between National Societies, UEG, and the YTG is necessary in order to offer young fellows the most productive and professionally satisfying future possible.

12.
Heart Rhythm ; 8(12): 1942-9, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21798226

RESUMO

BACKGROUND: A need exists to develop alternative approaches to VT ablation that provide an improved delineation of the arrhythmogenic substrate. OBJECTIVE: The aim of this study was to evaluate the hypotheses that: (1) the heterogeneous zone (HZ, a mixture of normal-appearing tissue and scar) in magnetic resonance imaging (MRI) contains the critical isthmus(es) for ventricular tachycardia (VT), (2) successful ablation of VT would include ablation in the HZ, and (3) inadequate ablation of HZ allows for VT recurrence. METHODS: MRI and an electrophysiology study (EP) were performed in a model of chronic myocardial infarction in 17 pigs. In animals that were inducible for VT, ablations were done guided by standard EP criteria and blinded to the MRI. After ablation, electroanatomic mapping results were co-registered with MRI. RESULTS: In 8 animals, 22 sustained monomorphic VTs were generated. The HZ was substantially larger in inducible (n = 8) compared with noninducible animals (n = 9) [25% ± 10% vs 13% ± 5% of total scar, respectively, P = .007]. Acutely, all targeted VTs were successfully ablated, and postprocedure analysis showed that at least 1 ablation was in the HZ in each animal. In 5 animals, a second EP and MRI were performed 1 week after ablation. Three animals had inducible VTs, and MRI showed that the HZ had not been completely ablated. In contrast, the 2 animals without inducible VT revealed no remaining HZ. CONCLUSION: These findings show that MRI can define an HZ and determine the location of ablated lesions. The HZ may be a promising ablation target to cure ischemic VTs. Remnants of HZ after ablation may be the substrate for clinical relapses.


Assuntos
Técnicas Eletrofisiológicas Cardíacas , Imageamento por Ressonância Magnética , Infarto do Miocárdio/complicações , Taquicardia Ventricular/patologia , Taquicardia Ventricular/fisiopatologia , Animais , Ablação por Cateter , Cicatriz/patologia , Gadolínio , Valor Preditivo dos Testes , Suínos , Taquicardia Ventricular/etiologia , Taquicardia Ventricular/cirurgia
13.
Phys Chem Chem Phys ; 13(10): 4452-62, 2011 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-21264385

RESUMO

Specific and reversible binding of guest molecules from a solution to a surface pre-treated with host molecules is a recent and active field of research. Self-assembled monolayers may result from supramolecular interactions, adding distinct functionalities to the surface. In this frame, the first compared study is given here of the anchoring on the technologically relevant Cu surface of calix[4]arene receptors and calix[6]arene-based rotaxanes and pseudorotaxanes. These molecules, which belong to the most representative classes of compounds in supramolecular chemistry, have been chosen for their synthetic accessibility and versatility, which make them useful building blocks for the synthesis of new advanced supramolecular structures. Covalent functionalisation of calix[4,6]arenes on Cu was reached via a dip-coating procedure, optimizing the various synthetic aspects in order to obtain good coverages and copper passivation. Molecular adhesion has been demonstrated by the presence and relative quantitation of XPS signals from specific elements in the molecules. We have successfully tested the combination of different functionalities by producing a mixed film, prepared by ligand exchange of calix[4]arene with undecanethiol. The availability of the calix[4]arene cavity to reversibly host further species after anchoring on Cu has been demonstrated by a sequence of uptake and release cycles with pyridinium salts. Rotaxane and pseudorotaxane species, composed of a calix[6]arene wheel functionalized with N-phenylurea groups on the upper rim, and a viologen-containing axle, have been anchored on Cu via the SH-termination of the axle. XPS demonstrated the successful self-assembly of fully threaded rotaxanes and pseudorotaxanes from their solutions and the controlled release upon biasing of full rotaxanes and of the pseudorotaxane wheel.

14.
J Nanosci Nanotechnol ; 11(10): 9333-9, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22400346

RESUMO

We report the first compared study of the anchoring mode of calix[6]arene derivatives and pseudorotaxanes on Si(100) and polycrystalline Cu. Calixarenes have been chosen for their flexibility as linkers, being, i.a., efficient building blocks for the constructing of molecular devices based on pseudorotaxanes and rotaxanes. A covalent functionalization on Si or Cu surfaces requires the molecules to be differently modified: thiol (-SH) or C double bond C terminations are respectively suitable for Cu or H-Si(100). Anchoring on Cu was reached by dipping a clean substrate in a calix[6]arene-SH solution, while a wet-chemistry recipe was followed for Si(100), combined with an extra-mild photochemical activation via visible light. Molecular adhesion onto either surfaces has been demonstrated by the presence of XPS signals from specific elements in the molecules: calix[6]arene designed for H-Si were derivatized with NO2 groups on the upper rim of the calix, while the S atom was used as the molecular identifier on Cu. A further extension is represented by the anchoring reaction of rotaxanes on Si(100) and Cu surfaces. A pseudorotaxane species was first formed in solution by reacting a calix[6]arene "wheel," bearing three N-phenylureido groups on the upper rim, with viologen (4,4'-bipyridinium) containing axle. The resulting species has then been anchored on either Cu and Si via its distinct termination of the axle. This two-step reaction has produced a threaded pseudorotaxane covalently bound to either surfaces, as shown by XPS results. These species are ready to respond to external stimuli. We also cross-checked the two different anchoring groups for their reactivity on Cu and Si surfaces. No molecular uptake was observed when two solutions, containing calixarenes with the anchoring arms intended either for Si or Cu surfaces, were exchanged.

15.
Circ Arrhythm Electrophysiol ; 3(5): 521-9, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20657028

RESUMO

BACKGROUND: Failure to achieve properly localized, permanent tissue destruction is a common cause of arrhythmia recurrence after cardiac ablation. Current methods of assessing lesion size and location during cardiac radiofrequency ablation are unreliable or not suited for repeated assessment during the procedure. MRI thermography could be used to delineate permanent ablation lesions because tissue heating above 50°C is the cause of permanent tissue destruction during radiofrequency ablation. However, image artifacts caused by cardiac motion, the ablation electrode, and radiofrequency ablation currently pose a challenge to MRI thermography in the heart. In the current study, we sought to demonstrate the feasibility of MRI thermography during cardiac ablation. METHODS AND RESULTS: An MRI-compatible electrophysiology catheter and filtered radiofrequency ablation system was used to perform ablation in the left ventricle of 6 mongrel dogs in a 1.5-T MRI system. Fast gradient-echo imaging was performed before and during radiofrequency ablation, and thermography images were derived from the preheating and postheating images. Lesion extent by thermography was within 20% of the gross pathology lesion. CONCLUSIONS: MR thermography appears to be a promising technique for monitoring lesion formation and may allow for more accurate placement and titration of ablation, possibly reducing arrhythmia recurrences.


Assuntos
Arritmias Cardíacas/diagnóstico , Temperatura Corporal/fisiologia , Ablação por Cateter , Imageamento por Ressonância Magnética/métodos , Cuidados Pré-Operatórios , Termografia/métodos , Animais , Arritmias Cardíacas/fisiopatologia , Arritmias Cardíacas/cirurgia , Diagnóstico Diferencial , Modelos Animais de Doenças , Cães , Prognóstico , Prevenção Secundária
16.
Phys Chem Chem Phys ; 12(32): 9230-8, 2010 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-20582359

RESUMO

Copper corrosion in alkaline solutions is inhibited by the formation of self-assembled monolayers of aromatic thiols, made of either benzenethiol or 2-naphthalenethiol or 4-acetamidothiophenol. Electrochemical experiments, based on voltammetry and impedance spectroscopy, point out the much lower reactivity of copper surfaces towards oxidation, when covered by compact adlayers of the above molecules bonded through the S atom. The peculiar shape and peak position in the voltammetric reduction of residual oxides grown on modified metal surfaces suggest that they are due to Cu(I) suboxides, probably grown on reactive metal defects. XPS experiments have confirmed that the aromatic adlayers are still covering most of the Cu surface even after 1 h immersion in 0.5 M NaOH. The main changes in Auger and XP spectra indicate the formation of much less Cu(2)O in the protected samples than in the corresponding bare Cu aged in NaOH. From the experimental data the presence of defective copper oxides on modified Cu has been deduced.

17.
Phys Chem Chem Phys ; 11(48): 11624-30, 2009 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-20024435

RESUMO

The adsorption of aromatic thiols on Cu and the SAM film stability in acidic solutions have been studied by XPS, contact angle and electrochemical techniques. Three short molecules, benzenethiol (BT), 2-naphthalenethiol (2-NT) and 4-acetamidothiophenol (4-AA), were selected as representatives of aromatic thiols to highlight the effect of aromatic rings and hydrophilic terminal groups on the copper protection. All the three molecules form stable S-Cu bonds as a consequence of their adsorption process on polycrystalline copper. Although none of them provides a full copper passivation, the adsorbed films persist without major degradation on Cu electrodes even after 12 h immersion in 0.5 M sulfuric acid. Comparing the freshly prepared adsorbed films, the larger 2-NT molecule provides a better Cu passivation, but the shorter BT molecule favours a higher surface coverage. The terminal groups of 4-AA are responsible for a higher Cu surface wettability in water, compared to that with SAMs of the other molecules, and allow for an easier charge-transfer to the electrolyte and for a higher electrochemical capacitance. After long enough ageing, however, the 4-AA-based molecular films are able to self-organize and to provide a steadily improving copper passivation. Adlayers of the BT and 2-NT molecules, on the contrary, over a long time tend to protect less and less the Cu substrate, probably because of progressive electrolyte infiltration.

18.
Circulation ; 120(14): 1426-35, 2009 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-19770397

RESUMO

BACKGROUND: We investigated the effects of intra-cardiopulmonary resuscitation (CPR) hypothermia with and without volume loading on return to spontaneous circulation and infarction size in an ischemic model of cardiac arrest. METHODS AND RESULTS: Using a distal left anterior descending artery occlusion model of cardiac arrest followed by resuscitation with a total of 120 minutes of occlusion and 90 minutes of reperfusion, we randomized 46 pigs into 5 groups and used myocardial staining to define area at risk and myocardial necrosis. Group A had no intervention. Immediately after return of spontaneous circulation, group B received surface cooling with cooling blankets and ice. Group C received intra-CPR 680+/-23 mL of 28 degrees C 0.9% normal saline via a central venous catheter. Group D received intra-CPR 673+/-26 mL of 4 degrees C normal saline followed by surface cooling after return of spontaneous circulation. Group E received intra-CPR and hypothermia after return of spontaneous circulation with an endovascular therapeutic hypothermia system placed in the right atrium and set at a target of 32 degrees C. Intra-CPR volume loading with room temperature (group C) or iced saline (group D) significantly (P<0.05) decreased coronary perfusion pressure (group C, 12.8+/-4.78 mm Hg; group D, 14.6+/-9.9 mm Hg) compared with groups A, B, and E (20.6+/-8.2, 20.1+/-7.8, and 21.3+/-12.4 mm Hg). Return of spontaneous circulation was significantly improved in group E (9 of 9) compared with groups A plus B and C (10 of 18 and 1 of 8). The percent infarction to the area at risk was significantly reduced with intra-CPR hypothermia in groups D (24.3+/-4.2%) and E (4+/-3.4%) compared with groups A (72+/-5.1%) and B (67.3+/-4.2%). CONCLUSIONS: Intra-CPR hypothermia significantly reduces myocardial infarction size. Elimination of volume loading further improves outcomes.


Assuntos
Reanimação Cardiopulmonar/métodos , Parada Cardíaca/terapia , Hipotermia Induzida/métodos , Animais , Circulação Sanguínea/fisiologia , Pressão Sanguínea , Reanimação Cardiopulmonar/instrumentação , Cateterismo/instrumentação , Cateterismo/métodos , Modelos Animais de Doenças , Artéria Femoral/fisiologia , Hipotermia Induzida/instrumentação , Infarto do Miocárdio/patologia , Suínos , Sístole , Função Ventricular Esquerda/fisiologia
19.
Circ Res ; 101(9): 939-47, 2007 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-17916777

RESUMO

In catheter ablation of scar-related monomorphic ventricular tachycardia (VT), substrate voltage mapping is used to electrically define the scar during sinus rhythm. However, the electrically defined scar may not accurately reflect the anatomical scar. Magnetic resonance-based visualization of the scar may elucidate the 3D anatomical correlation between the fine structural details of the scar and scar-related VT circuits. We registered VT activation sequence with the 3D scar anatomy derived from high-resolution contrast-enhanced MRI in a swine model of chronic myocardial infarction using epicardial sock electrodes (n=6, epicardial group), which have direct contact with the myocardium where the electrical signal is recorded. In a separate group of animals (n=5, endocardial group), we also assessed the incidence of endocardial reentry in this model using endocardial basket catheters. Ten to 12 weeks after myocardial infarction, sustained monomorphic VT was reproducibly induced in all animals (n=11). In the epicardial group, 21 VT morphologies were induced, of which 4 (19.0%) showed epicardial reentry. The reentry isthmus was characterized by a relatively small volume of viable myocardium bound by the scar tissue at the infarct border zone or over the infarct. In the endocardial group (n=5), 6 VT morphologies were induced, of which 4 (66.7%) showed endocardial reentry. In conclusion, MRI revealed a scar with spatially complex structures, particularly at the isthmus, with substrate for multiple VT morphologies after a single ischemic episode. Magnetic resonance-based visualization of scar morphology would potentially contribute to preprocedural planning for catheter ablation of scar-related, unmappable VT.


Assuntos
Ablação por Cateter/efeitos adversos , Cicatriz/etiologia , Cicatriz/patologia , Imageamento por Ressonância Magnética/métodos , Taquicardia Ventricular/etiologia , Taquicardia Ventricular/patologia , Animais , Cicatriz/fisiopatologia , Eletrodos , Miocárdio/patologia , Sus scrofa , Taquicardia Ventricular/fisiopatologia
20.
Cad. saúde colet., (Rio J.) ; 11(1): 93-112, jan.-jun. 2003. tab
Artigo em Português | LILACS | ID: lil-352165

RESUMO

Este artigo resulta da aplicaçäo do método formalizado de previsäo de cenários de Godet à realidade do Programa de Saúde da Família. Compöe-se de uma síntese do método, da contextualizaçäo histórica da proposiçäo do Programa de Saúde da Família (PSF) e da análise prospectiva do PSF. O exercício se desenvolve em 7 passos e ao final define-se um cenário central, um otimista e um pessimista. Entre as variáveis consideradas, evidencia-se o controle social e flexibilidade para adaptaçäo local como as que desempenham papel mais estratégico para o sucesso do programa.


Assuntos
Saúde da Família , Planos e Programas de Saúde , Planejamento Estratégico
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