Agentes infecciosos em ateromas coronarianos: um possível papel na patogênese da ruptura da placa e infarto agudo do miocárdio

In this review we report our recent findings of histopathological features of plaque instability and the association with Mycoplasma pneumoniae (MP) and Chlamydia pneumoniae (CP) infection, studying thrombosed coronary artery segments (CAS) of patients who died due to acute myocardial infarction. Vulnerable plaques are known to be associated with fat atheromas and inflammation of the plaque. Here we demonstrated that vulnerability is also related with focal positive vessel remodeling that maintains relatively well preserved lumen even in the presence of large atheromatous plaques. This phenomena may explain why the cinecoronariography may not detect large and dangerous vulnerable plaques. Greater amount of these bacteria in vulnerable plaques is associated with adventitial inflammation and positive vessel remodeling: the mean numbers of lymphocytes were significantly higher in adventitia than in the plaque, good direct correlation was obtained between numbers of CD20 B cells and numbers of CP infected cells in adventitia, and between % area of MP-DNA in the plaque and cross sectional area of the vessel, suggesting a cause-effect relationship. Mycoplasma is a bacterium that needs cholesterol for proliferation and may increase virulence of other infectious agents. In conclusion, co-infection by Mycoplasma pneumoniae and Chlamydia pneumoniae may represent an important co-factor for plaque instability, leading to coronary plaque thrombosis and acute myocardial infarction, since larger amount of these bacteria strongly correlated with histological signs of more vulnerability of the plaque. The search of CMV and Helicobacter pilori in these tissues resulted negative.Nesta revisão relatamos recentes achados nossos sobre aspectos histológicos de instabilidade da placa e a associação com Mycoplasma pneumoniae (MP) e Chlamydia pneumoniae (CP), estudando segmentos de artéria coronária trombosados de pacientes que faleceram por infarto agudo do miocárdio. Placas vulneráveis são conhecidas como sendo placas gordurosas e com inflamação. Aqui demonstramos que a vulnerabilidade está também relacionada com remodelamento positivo do vaso o qual pode preservar a luz do vaso mesmo na presença de uma placa de ateroma grande. Grande quantidade dessas bactérias em placas vulneráveis está associada a inflamação da adventícia e remodelamento positivo do vaso: o número médio de linfócitos foi significativamente maior na adventícia do que na placa, e boas correlações diretas foram obtidas entre os números médios de células B CD20 e os números de células infectadas por CP na adventícia, e entre as % de áreas positivas para MP na placa e as áreas em secção transversal dos respectivos vasos, sugerindo uma relação de causa - efeito entre esses agentes infecciosos e vulnerabilidade da placa. Micoplasma é uma bactéria que necessita colesterol para a proliferação e pode aumentar a virulência de outros agentes infecciosos. Em conclusão, co-infecção por Mycoplasma pneumoniae e Chlamydia pneumoniae pode representar um importante co-fator de instabilidade da placa, levando a trombose da placa coronariana e infarto agudo do miocárdio, pois a maior quantidade dessas bactérias mostrou forte correlação com sinais histológicos de maior vulnerabilidade da placa. A pesquisa nesses tecidos de CMV e Helicobacter pilori foi negativa

Pollutants removal onto novel activated carbons made from lignocellulosic precursors

The adsorption of phenol and mercury from dilute aqueous solutions onto new activated carbons was studied. These included activated carbons produced from novel precursors, namely rapeseed, vine shoots and kenaf, and samples oxidised with nitric acid in liquid phase. The results have shown the significant potential of rapeseed, vine shoots and kenaf for the activated carbon production. The activated carbons produced by carbon dioxide activation were mainly microporous with BET apparent surface area up to 1224m2g-1 and pore volume 0.5cm3g-1. The effects of concentration and pH were studied. The phenol adsorption isotherms at 25ºC followed the Freundlich model with maximum adsorption capacities of approximately 80mgg-1 and 60mgg-1 for the pristine and oxidised activated carbons, respectively. The influence of pH on the phenol adsorption has two trends for pH smaller and bigger than 10. The maximum adsorption capacity of mercury adsorption onto activated carbon made from vine shoots reaches 1103mgg-1. The adsorption depends on the mercury species and the on the adsorbent properties, namely porosity and net surface charge

The involvement of multiple thrombogenic and atherogenic markers in premature coronary artery disease

OBJECTIVE: To examine the association of atherogenic and thrombogenic markers and lymphotoxin-alfa gene mutations with the risk of premature coronary disease. METHODS: This cross-sectional, case-control, age-adjusted study was conducted in 336 patients with premature coronary disease (;50% luminal reduction) or a previous myocardial infarction. The laboratory data evaluated included thrombogenic factors (fibrinogen, protein C, protein S, and antithrombin III), atherogenic factors (glucose and lipid profiles, lipoprotein(a), and apolipoproteins AI and B), and lymphotoxin-alfa mutations. Genetic variability of lymphotoxin-alfa was determined by polymerase chain reaction analysis. RESULTS: Coronary disease patients exhibited lower concentrations of HDL-cholesterol and higher levels of glucose, lipoprotein(a), and protein S. The frequencies of AA, AG, and GG lymphotoxin-alfa mutation genotypes were 55.0%, 37.6%, and 7.4% for controls and 42.7%, 46.0%, and 11.3% for coronary disease patients (p = 0.02), respectively. Smoking, dyslipidemia, family history, and lipoprotein(a) and lymphotoxin-alfa mutations in men were independent variables associated with coronary disease. The area under the curve (C-statistic) increased from 0.779 to 0.802 (

Echocardiographic and hemodynamic determinants of right coronary artery flow reserve and phasic flow pattern in advanced non-ischemic cardiomyopathy

<p>Abstract</p> <p>Background</p> <p>In patients with advanced non-ischemic cardiomyopathy (NIC), right-sided cardiac disturbances has prognostic implications. Right coronary artery (RCA) flow pattern and flow reserve (CFR) are not well known in this setting. The purpose of this study was to assess, in human advanced NIC, the RCA phasic flow pattern and CFR, also under right-sided cardiac disturbances, and compare with left coronary circulation. As well as to investigate any correlation between the cardiac structural, mechanical and hemodynamic parameters with RCA phasic flow pattern or CFR.</p> <p>Methods</p> <p>Twenty four patients with dilated severe NIC were evaluated non-invasively, even by echocardiography, and also by cardiac catheterization, inclusive with Swan-Ganz catheter. Intracoronary Doppler (Flowire) data was obtained in RCA and left anterior descendent coronary artery (LAD) before and after adenosine. Resting RCA phasic pattern (diastolic/systolic) was compared between subgroups with and without pulmonary hypertension, and with and without right ventricular (RV) dysfunction; and also with LAD. RCA-CFR was compared with LAD, as well as in those subgroups. Pearson's correlation analysis was accomplished among echocardiographic (including LV fractional shortening, mass index, end systolic wall stress) more hemodynamic parameters with RCA phasic flow pattern or RCA-CFR.</p> <p>Results</p> <p>LV fractional shortening and end diastolic diameter were 15.3 ± 3.5 % and 69.4 ± 12.2 mm. Resting RCA phasic pattern had no difference comparing subgroups with vs. without pulmonary hypertension (1.45 vs. 1.29, p = NS) either with vs. without RV dysfunction (1.47 vs. 1.23, p = NS); RCA vs. LAD was 1.35 vs. 2.85 (p < 0.001). It had no significant correlation among any cardiac mechanical or hemodynamic parameter with RCA-CFR or RCA flow pattern. RCA-CFR had no difference compared with LAD (3.38 vs. 3.34, p = NS), as well as in pulmonary hypertension (3.09 vs. 3.10, p = NS) either in RV dysfunction (3.06 vs. 3.22, p = NS) subgroups. </p> <p>Conclusion</p> <p>In patients with chronic advanced NIC, RCA phasic flow pattern has a mild diastolic predominance, less marked than in LAD, with no effects from pulmonary artery hypertension or RV dysfunction. There is no significant correlation between any cardiac mechanical-structural or hemodynamic parameter with RCA-CFR or RCA phasic flow pattern. RCA flow reserve is still similar to LAD, independently of those right-sided cardiac disturbances.</p