Pentoxifylline reduces inflammation and prevents myocardial perfusion derangements in experimental chronic Chagas' cardiomyopathy

BACKGROUND

Myocardial perfusion defect (MPD) is common in chronic Chagas cardiomyopathy (CCC) and is associated with inflammation and development of left ventricular systolic dysfunction. We tested the hypothesis that pentoxifylline (PTX) could reduce inflammation and prevent the development of MPD in a model of CCC in hamsters.

METHODS AND RESULTS

We investigated with echocardiogram and rest myocardial perfusion scintigraphy at baseline (6-months after T. cruzi infection/saline) and post-treatment (after additional 2-months of PTX/saline administration), female Syrian hamsters assigned to 3 groups: T. cruzi-infected animals treated with PTX (CH + PTX) or saline (CH + SLN); and uninfected control animals (CO). At the baseline, all groups showed similar left ventricular ejection fraction (LVEF) and MPD areas. At post-treatment evaluation, there was a significant increase of MPD in CH + SLN group (0.8 ± 1.6 to 9.4 ± 9.7%), but not in CH + PTX (1.9 ± 3.0% to 2.7 ± 2.7%) that exhibited MPD area similar to CO (0.0 ± 0.0% to 0.0 ± 0.0%). The LVEF decreased in both infected groups. Histological analysis showed a reduced inflammatory infiltrate in CH + PTX group (395.7 ± 88.3 cell/mm2), as compared to CH + SLN (515.1 ± 133.0 cell/mm2), but larger than CO (193.0 ± 25.7 cell/mm2). The fibrosis and TNF-α expression was higher in both infected groups.

CONCLUSIONS

The prolonged use of PTX is associated with positive effects, including prevention of MPD development and reduction of inflammation in the chronic hamster model of CCC.

Distinct Microbial Communities in Dilated Cardiomyopathy Explanted Hearts Are Associated With Different Myocardial Rejection Outcomes

Background

Idiopathic dilated cardiomyopathy (IDCM) myocardial inflammation may be associated with external triggering factors such as infectious agents. Here, we searched if moderate/severe heart transplantation rejection is related to the presence of myocardial inflammation in IDCM explanted hearts, associated with microbial communities.

Method

Receptor myocardial samples from 18 explanted hearts were separated into groups according to post-transplant outcome: persistent moderate rejection (PMR; n = 6), moderate rejection (MR; n = 7) that regressed after pulse therapy, and no rejection (NR; n = 5)/light intensity rejection. Inflammation was quantified through immunohistochemistry (IHC), and infectious agents were evaluated by IHC, molecular biology, in situ hybridization technique, and transmission electron microscopy (TEM).

Results

NR presented lower numbers of macrophages, as well as B cells (p = 0.0001), and higher HLA class II expression (p ≤ 0.0001). PMR and MR showed higher levels of Mycoplasma pneumoniae (p = 0.003) and hepatitis B core (p = 0.0009) antigens. NR presented higher levels of parvovirus B19 (PVB19) and human herpes virus 6 (HHV6) and a positive correlation between Borrelia burgdorferi (Bb) and enterovirus genes. Molecular biology demonstrated the presence of M. pneumoniae, Bb, HHV6, and PVB19 genes in all studied groups. TEM revealed structures compatible with the cited microorganisms.

Conclusions

This initial study investigating on infectious agents and inflammation in the IDCM explanted hearts showed that the association between M. pneumoniae and hepatitis B core was associated with a worse outcome after HT, represented by MR and PMR, suggesting that different IDCM microbial communities may be contributing to post-transplant myocardial rejection.

Morphomolecular Characterization of Serum Nanovesicles From Microbiomes Differentiates Stable and Infarcted Atherosclerotic Patients

Microbial communities are considered decisive for maintaining a healthy situation or for determining diseases. Acute myocardial infarction (AMI) is an important complication of atherosclerosis caused by the rupture of atheroma plaques containing proinflammatory cytokines, reactive oxygen species, oxidized low-density lipoproteins (oxLDL), damaged proteins, lipids, and DNA, a microenvironment compatible with a pathogenic microbial community. Previously, we found that archaeal DNA-positive infectious microvesicles (iMVs) were detected in vulnerable plaques and in the sera of Chagas disease patients with heart failure. Now, we characterize and quantify the levels of serum microbiome extracellular vesicles through their size and content using morphomolecular techniques to differentiate clinical outcomes in coronary artery disease (CAD). We detected increased numbers of large iMVs (0.8–1.34 nm) with highly negative surface charge that were positive for archaeal DNA, Mycoplasma pneumoniae antigens and MMP9 in the sera of severe AMI patients, strongly favoring our hypothesis that pathogenic archaea may play a role in the worst outcomes of atherosclerosis. The highest numbers of EVs <100 nm (exosomes) and MVs from 100 to 200 nm in the stable atherosclerotic and control healthy groups compared with the AMI groups were indicative that these EVs are protective, entrapping and degrading infectious antigens and active MMP9 and protect against the development of plaque rupture.

Conclusion: A microbiome with pathogenic archaea is associated with high numbers of serum iMVs in AMI with the worst prognosis. This pioneering work demonstrates that the morphomolecular characterization and quantification of iEVs in serum may constitute a promising serum prognostic biomarker in CAD.

Advanced Therapies for Ventricular Arrhythmias in Patients With Chagasic Cardiomyopathy: JACC State-of-the-Art Review

Chagas disease is caused by infection from the protozoan parasite Trypanosoma cruzi. Although it is endemic to Latin America, global migration has led to an increased incidence of Chagas in Europe, Asia, Australia, and North America. Following acute infection, up to 30% of patients will develop chronic Chagas disease, with most patients developing Chagasic cardiomyopathy. Chronic Chagas cardiomyopathy is highly arrhythmogenic, with estimated annual rates of appropriate implantable cardioverter-defibrillator therapies and electrical storm of 25% and 9.1%, respectively. Managing arrhythmias in patients with Chagasic cardiomyopathy is a major challenge for the clinical electrophysiologist, requiring intimate knowledge of cardiac anatomy, advanced training, and expertise. Endocardial-epicardial mapping and ablation strategy is needed to treat arrhythmias in this patient population, owing to the suboptimal long-term success rate of endocardial mapping and ablation alone. We also describe innovative approaches to improve acute and long-term clinical outcomes in patients with refractory ventricular arrhythmias following catheter ablation, such as bilateral cervicothoracic sympathectomy and bilateral renal denervation, among others.

Prolonged dipyridamole administration reduces myocardial perfusion defects in experimental chronic Chagas cardiomyopathy

BACKGROUND

Myocardial perfusion defects (MPD) due to coronary microvascular dysfunction is frequent in chronic Chagas cardiomyopathy (CCC) and may be involved with development of myocardial damage. We investigated whether MPD precedes left ventricular systolic dysfunction and tested the hypothesis that prolonged use of dipyridamole (DIPY) could reduce MPD in an experimental model of CCC in hamsters.

METHODS AND RESULTS

We investigated female hamsters 6-months after T. cruzi infection (baseline condition) and control animals, divided into T. cruzi-infected animals treated with DIPY (CH + DIPY) or placebo (CH + PLB); and uninfected animals treated with DIPY (CO + DIPY) or placebo (CO + PLB). The animals were submitted to echocardiogram and rest SPECT-Sestamibi-Tc99m myocardial perfusion scintigraphy. Next, the animals were treated with DIPY (4 mg/kg bid, intraperitoneal) or saline for 30 days, and reevaluated with the same imaging methods. At baseline, the CH + PLB and CH + DIPY groups showed larger areas of perfusion defect (13.2 ± 13.2% and 17.3 ± 13.2%, respectively) compared with CO + PLB and CO + DIPY (3.8 ± 2.2% e 3.5 ± 2.7%, respectively), P < .05. After treatment, we observed: reduction of perfusion defects only in the CH + DIPY group (17.3 ± 13.2% to 6.8 ± 7.6%, P = .001) and reduction of LVEF in CH + DIPY and CH + PLB groups (from 65.3 ± 9.0% to 53.6 ± 6.9% and from 69.3 ± 5.0% to 54.4 ± 8.6%, respectively, P < .001). Quantitative histology revealed greater extents of inflammation and interstitial fibrosis in both Chagas groups, compared with control group (P < .001), but no difference between Chagas groups (P > .05).

CONCLUSIONS

The prolonged use of DIPY in this experimental model of CCC has reduced the rest myocardial perfusion defects, supporting the notion that those areas correspond to viable hypoperfused myocardium.

Dysregulation of microRNAs and target genes networks in human abdominal aortic aneurysm tissues

BACKGROUND

Abdominal aortic aneurysm (AAA) is a pathological enlargement of infrarenal aorta close to the aortic bifurcation, and it is an important cause of mortality in the elderly. Therefore, the biomarker identification for early diagnosis is of great interest for clinical benefit. It is known that microRNAs (miRNAs) have important roles via target genes regulation in many diseases. This study aimed to identify miRNAs and their target genes involved in the pathogenesis of AAA.

METHODS

Tissue samples were obtained from patients who underwent AAA surgery and from organ donors (control group). Quantitative PCR Array was applied to assess 84 genes and 384 miRNAs aiming to identify differentially expressed targets (AAA n = 6, control n = 6), followed by validation in a new cohort (AAA n = 18, control n = 6) by regular qPCR. The functional interaction between validated miRNAs and target genes was performed by the Ingenuity Pathway Analysis (IPA) software.

RESULTS

The screening cohort assessed by PCR array identified 10 genes and 59 miRNAs differentially expressed (≥2-fold change, p<0.05). Among these, IPA identified 5 genes and 9 miRNAs with paired interaction. ALOX5, PTGIS, CX3CL1 genes, and miR-193a-3p, 125b-5p, 150-5p maintained a statistical significance in the validation cohort. IPA analysis based on the validated genes and miRNAs revealed that eicosanoid and metalloproteinase/TIMP synthesis are potentially involved in AAA.

CONCLUSION

Paired interactions of differentially expressed ALOX5, PTGIS, CX3CL1 genes, and miR-193b-3p, 125b-5p, 150-5p revealed a potentially significant role of the eicosanoid synthesis and metalloproteinase/TIMP pathways in the AAA pathogenesis.

Archaea Symbiont of T. cruzi Infection May Explain Heart Failure in Chagas Disease

Background: Archaeal genes present in Trypanosoma cruzi may represent symbionts that would explain development of heart failure in 30% of Chagas disease patients. Extracellular vesicles in peripheral blood, called exosomes (< 0.1 μm) or microvesicles (>0.1 μm), present in larger numbers in heart failure, were analyzed to determine whether they are derived from archaea in heart failure Chagas disease. Methods: Exosomes and microvesicles in serum supernatant from 3 groups were analyzed: heart failure Chagas disease (N = 26), asymptomatic indeterminate form (N = 21) and healthy non-chagasic control (N = 16). Samples were quantified with transmission electron microscopy, flow cytometer immunolabeled with anti-archaemetzincin-1 antibody (AMZ 1, archaea collagenase) and probe anti-archaeal DNA and zymography to determine AMZ1 (Archaeal metalloproteinase) activity. Results: Indeterminate form patients had higher median numbers of exosomes/case vs. heart failure patients (58.5 vs. 25.5, P < 0.001), higher exosome content of AMZ1 antigens (2.0 vs. 0.0; P < 0.001), and lower archaeal DNA content (0.2 vs. 1.5, P = 0.02). A positive correlation between exosomes and AMZ1 content was seen in indeterminate form (r = 0.5, P < 0.001), but not in heart failure patients (r = 0.002, P = 0.98). Higher free archaeal DNA (63.0 vs. 11.1, P < 0.001) in correlation with exosome numbers (r = 0.66, P = 0.01) was seen in heart failure but not in indeterminate form (r = 0.29, P = 0.10). Flow cytometer showed higher numbers of AMZ1 microvesicles in indeterminate form (64 vs. 36, P = 0.02) and higher archaeal DNA microvesicles in heart failure (8.1 vs. 0.9, P < 0.001). Zymography showed strong% collagenase activity in HF group, mild activity in IF compared to non-chagasic healthy group (121 ± 14, 106 ± 13 and 100; P < 0.001). Conclusions: Numerous exosomes, possibly removing and degrading abnormal AMZ1 collagenase, are associated with indeterminate form. Archaeal microvesicles and their exosomes, possibly associated with release of archaeal AMZ1 in heart failure, are future candidates of heart failure biomarkers if confirmed in larger series, and the therapeutic focus in the treatment of Chagas disease.

Persistent Inflammatory Activity in Blood Cells and Artery Tissue from Patients with Previous Bare Metal Stent

BACKGROUND

Studies have pointed out a higher mortality after coronary artery bypass surgery (CABG) in patients with stent.

OBJECTIVE

To evaluate inflammatory markers in peripheral blood cells and in coronary artery tissue samples obtained during CABG in patients with stent compared to controls.

METHODS

The case series consisted of two groups, one with previous stent implantation (n = 41) and one control (n = 26). The expression of the LIGHT, IL-6, ICAM, VCAM, CD40, NFKB, TNF, IFNG genes was analyzed in peripheral blood cells collected preoperatively. The coronary artery was evaluated for: interleukin-6, ICAM, VCAM, CD40, NFKB, TNF-alpha and IFN-gamma by immunohistochemistry. A total of 176 tissue samples were grouped for analysis in: A1- arteries with stent (n = 38); A2- native arteries from patients with stent in another artery (n = 68); and A3- arteries without stent from controls undergoing routinely CABG surgery (n = 70). A significance level of 0.05 was adopted.

RESULTS

Patients with stent showed higher TNF (p = 0.03) and lower CD40 gene expression (p = 0.01) in peripheral blood cells than controls without stent. In coronary artery samples, the TNF-alpha protein staining was higher in the group A1, not only in the intima-media layer (5.16 ± 5.05 vs 1.90 ± 2.27; p = 0.02), but also in the adipose tissue (6.69 ± 3.87 vs 2.27 ± 4.00; p < 0.001). Furthermore, group A1 had a higher interleukin-6 protein staining in adipose tissue than group A3 (p = 0.04).

CONCLUSION

We observed a persistently higher systemic TNF expression associated with exacerbated TNF-alpha and interleukin-6 local production in patients with stents. This finding may contribute to a worse clinical outcome.

Bacteria arise at the border of mycoplasma-infected HeLa cells, containing cytoplasm with either malformed cytosol, mitochondria and endoplasmic reticulum or tightly adjoined smooth vacuoles

A study with transmission electron microscopy of mycoplasma-contaminated HeLa cells using five cell donors referred to as donors A, B, C, D and E, observations are herein presented. Experiments performed with cells from donors B, C and D, revealed the presence of Mycoplasma hyorhinis after PCR and sequencing experiments. Bacteria probably originated from a cytoplasm with compacted tiny granular particles replacing the normal cytosol territories, or from the contact with the cytoplasm through a clear semi-solid material. The compact granularity (CG) of the cytoplasm was crossed by stripes of smooth and rough endoplasmic reticulum cisternae. Among apparently normal mitochondria, it was noted, in variable proportions, mitochondria with crista-delimited lucent central regions that expand to and occupied the interior of a crista-less organelle, which can undergo fission. Other components of the scenarios of mycoplasma-induced cell demolition are villus-like structures with associated 80-200 nm vesicles and a clear, flexible semi-solid, process-sensitive substance that we named jam-like material. This material coated the cytoplasmic surface, its recesses, irregular protrusions and detached cytoplasmic fragments. It also cushioned forming bacteria. Cyst-like structures were often present in the cytoplasm. Cells, mainly apoptotic, exhibiting ample cytoplasmic sectors with characteristic net-like profile due to adjoined vacuoles, as well as ovoid or elongated profiles, consistently appeared in all cells from the last four cell donors. These cells were named “modified host cells” because bacteria arose in the vacuoles. The possibility that, in some samples, there was infection and/or coinfection of the host cell by another organism(s) cannot be ruled out.

Infectious agents is a risk factor for myxomatous mitral valve degeneration: A case control study

BACKGROUND

The etiology of myxomatous mitral valve degeneration (MVD) is not fully understood and may depend on time or environmental factors for which the interaction of infectious agents has not been documented. The purpose of the study is to analyze the effect of Mycoplasma pneumoniae (Mp), Chlamydophila pneumoniae (Cp) and Borrelia burgdorferi (Bb) on myxomatous mitral valve degeneration pathogenesis and establish whether increased in inflammation and collagen degradation in myxomatous mitral valve degeneration etiopathogenesis.

METHODS

An immunohistochemical test was performed to detect the inflammatory cells (CD20, CD45, CD68) and Mp, Bb and MMP9 antigens in two groups. The in situ hybridization was performed to detect Chlamydophila pneumoniae and the bacteria study was performed using transmission electron microscopy. Group 1 (n = 20), surgical specimen composed by myxomatous mitral valve degeneration, and group 2 (n = 20), autopsy specimen composed by normal mitral valve. The data were analyzed using SigmaStat version 20 (SPSS Inc., Chicago, IL, USA). The groups were compared using Student's t test, Mann-Whitney test. A correlation analysis was performed using Spearman's correlation test. P values lower than 0.05 were considered statistically significant.

RESULTS

By immunohistochemistry, there was a higher inflammatory cells/mm2 for CD20 and CD45 in group 1, and CD68 in group 2. Higher number of Mp and Cp antigens was observed in group 1 and more Bb antigens was detected in group 2. The group 1 exhibited a positive correlation between the Bb and MVD percentage, between CD45 and Mp, and between MMP9 with Mp. These correlations were not observed in the group 2. Electron microscopy revealed the presence of structures compatible with microorganisms that feature Borrelia and Mycoplasma characteristics.

CONCLUSIONS

The presence of infectious agents, inflammatory cells and collagenases in mitral valves appear to contribute to the pathogenesis of MVD. Mycoplasma pneumoniae was strongly related with myxomatous mitral valve degeneration. Despite of low percentage of Borrelia burgdorferi in MD group, this agent was correlated with myxomatous degeneration and this may occour due synergistic actions between these infectious agents likely contribute to collagen degradation.

Previous exercise training increases levels of PPAR-α in long-term post-myocardial infarction in rats, which is correlated with better inflammatory response

OBJECTIVE

Exercise is a protective factor for cardiovascular morbidity and mortality, with unclear mechanisms. Changing the myocardial metabolism causes harmful consequences for heart function and exercise contributes to metabolic adjustment modulation. Peroxisome proliferator-activated receptors (PPARs) are also myocardium metabolism regulators capable of decreasing the inflammatory response. We hypothesized that PPAR-α is involved in the beneficial effects of previous exercise on myocardial infarction (MI) and cardiac function, changing the expression of metabolic and inflammatory response regulators and reducing myocardial apoptosis, which partially explains the better outcome.

METHODS AND RESULTS

Exercised rats engaged in swimming sessions for 60 min/day, 5 days/week, for 8 weeks. Both the exercised rats and sedentary rats were randomized to MI surgery and followed for 1 week (EI1 or SI1) or 4 weeks (EI4 or SI4) of healing or to sham groups. Echocardiography was employed to detect left ventricular function and the infarct size. Additionally, the TUNEL technique was used to assess apoptosis and immunohistochemistry was used to quantitatively analyze the PPAR-α, TNF-α and NF-κB antigens in the infarcted and non-infarcted myocardium. MI-related mortality was higher in SI4 than in EI4 (25% vs 12%), without a difference in MI size. SI4 exhibited a lower shortening fraction than EI4 did (24% vs 35%) and a higher apoptosis/area rate (3.97±0.61 vs 1.90±1.82) in infarcted areas (both p=0.001). Immunohistochemistry also revealed higher TNF-α levels in SI1 than in EI1 (9.59 vs 4.09, p<0.001) in infarcted areas. In non-infarcted areas, EI4 showed higher levels of TNF-α and positive correlations between PPAR-α and NF-κB (r=0.75, p=0.02), in contrast to SI4 (r=0.05, p=0.87).

CONCLUSION

Previously exercised animals had better long-term ventricular function post-MI, in addition to lower levels of local inflammatory markers and less myocardial apoptosis, which seemed to be related to the presence of PPAR-α.

Biomechanical Properties and Microstructural Analysis of the Human Nonaneurysmal Aorta as a Function of Age, Gender and Location: An Autopsy Study

INTRODUCTION

The biomechanical failure properties and histological composition of the human nonaneurysmal aorta were studied.

METHODS

Twenty-six human aortas were harvested from fresh cadavers at autopsy. A total of 153 circumferentially oriented strips were obtained from the aortas for biomechanical and histological studies.

RESULTS

The failure load (6.18 ± 2.03 vs. 4.85 ± 2.04 N; p = 0.001), failure tension (19.88 ± 9.05 vs. 14.53 ± 7 N/cm; p = 0.001), failure strain (0.66 ± 0.31 vs. 0.49 ± 0.25; p = 0.003) and amount of elastic fibers (19.39 ± 15.57 vs. 14.06 ± 9.5%; p = 0.011) were all significantly higher for the thoracic than the abdominal aorta. There was a significant negative correlation between age and failure load (R = -0.35; p < 0.0001), failure stress (R = -0.63; p < 0.0001), failure tension (R = -0.52; p < 0.0001) and failure strain (R = -0.8; p < 0.0001). Male aortas had a higher failure load and failure tension than female aortas.

CONCLUSION

The thoracic aorta has a higher strength and elasticity than the abdominal aorta. The elderly have weaker and stiffer aortas than the young. Male aortas are stronger than female aortas.

Histopathological Correlates of Global and Segmental Left Ventricular Systolic Dysfunction in Experimental Chronic Chagas Cardiomyopathy

Background

Chronic Chagas cardiomyopathy in humans is characterized by segmental left ventricular wall motion abnormalities (WMA), mainly in the early stages of disease. This study aimed at investigating the detection of WMA and its correlation with the underlying histopathological changes in a chronic Chagas cardiomyopathy model in hamsters.

Methods and Results

Female Syrian hamsters (n=34) infected with 3.5×10⁴ or 10⁵ blood trypomastigote Trypanosoma cruzi (Y strain) forms and an uninfected control group (n=7) were investigated. After 6 or 10 months after the infection, the animals were submitted to in vivo evaluation of global and segmental left ventricular systolic function by echocardiography, followed by euthanasia and histological analysis for quantitative assessment of fibrosis and inflammation with tissue sampling in locations coinciding with the left ventricular wall segmentation employed at the in vivo echocardiographic evaluation. Ten of the 34 infected animals (29%) showed reduced left ventricular ejection fraction (<73%). Left ventricular ejection fraction was more negatively correlated with the intensity of inflammation (r=−0.63; P<0.0001) than with the extent of fibrosis (r=−0.36; P=0.036). Among the 24 animals with preserved left ventricular ejection fraction (82.9±5.5%), 8 (33%) showed segmental WMA predominating in the apical, inferior, and posterolateral segments. The segments exhibiting WMA, in comparison to those with normal wall motion, showed a greater extent of fibrosis (9.3±5.7% and 7±6.3%, P<0.0001) and an even greater intensity of inflammation (218.0±111.6 and 124.5±84.8 nuclei/mm², P<0.0001).

Conclusions

Isolated WMA with preserved global systolic left ventricular function is frequently found in Syrian hamsters with experimental chronic Chagas cardiomyopathy whose underlying histopathological features are mainly inflammatory.

Infectious agents and inflammation in donated hearts and dilated cardiomyopathies related to cardiovascular diseases, Chagas' heart disease, primary and secondary dilated cardiomyopathies

BACKGROUND

Clinical and experimental conflicting data have questioned the relationship between infectious agents, inflammation and dilated cardiomyopathy (DCM).

OBJECTIVES

The aim of this study was to determine the frequency of infectious agents and inflammation in endomyocardial biopsy (EMB) specimens from patients with idiopathic DCM, explanted hearts from different etiologies, including Chagas' disease, compared to donated hearts.

METHODS

From 2008 to 2011, myocardial samples from 29 heart donors and 55 patients with DCMs from different etiologies were studied (32 idiopathic, 9 chagasic, 6 ischemic and 8 other specific etiologies). Inflammation was investigated by immunohistochemistry and infectious agents by immunohistochemistry, molecular biology, in situ hybridization and electron microscopy.

RESULTS

There were no differences regarding the presence of macrophages, expression of HLA class II and ICAM-I in donors and DCM. Inflammation in Chagas' disease was predominant. By immunohistochemistry, in donors, there was a higher expression of antigens of enterovirus and Borrelia, hepatitis B and C in DCMs. By molecular biology, in all groups, the positivity was elevated to microorganisms, including co-infections, with a higher positivity to adenovirus and HHV6 in donors towards DCMs. This study was the first to demonstrate the presence of virus in the heart tissue of chagasic DCM.

CONCLUSIONS

The presence of inflammation and infectious agents is frequent in donated hearts, in the myocardium of patients with idiopathic DCM, myocardial dysfunction related to cardiovascular diseases, and primary and secondary cardiomyopathies, including Chagas' disease. The role of co-infection in Chagas' heart disease physiopathology deserves to be investigated in future studies.

Synergistic anti-inflammatory effect: simvastatin and pioglitazone reduce inflammatory markers of plasma and epicardial adipose tissue of coronary patients with metabolic syndrome

BACKGROUND

The inappropriate secretion of adipocytokines plays a critical role in chronic inflammatory states associated with obesity-linked type 2 diabetes and atherosclerosis. The pleiotropic actions of simvastatin and pioglitazone on epicardial adipose tissue (EAT) are unknown. This study assessed the anti-inflammatory actions of simvastatin and pioglitazone on EAT in patients with coronary artery disease (CAD) and metabolic syndrome (MS).

METHODS

A total of 73 patients with multivessel CAD who underwent elective bypass grafting were non-randomly allocated to one of four subgroups: Control (n = 17), simvastatin (20 mg/day, n = 20), pioglitazone (15 mg or 30 mg/day, n = 18), or simvastatin + pioglitazone (20 mg/day + 30 mg/day, respectively, n = 18); 20 valvar patients were also included. EAT samples were obtained during surgery. The infiltration of macrophages and lymphocytes and cytokines secretion were investigated using immunohistochemical staining and compared to plasma inflammatory biomarkers.

RESULTS

Simvastatin significantly reduced plasma interleukin-6, leptin, resistin and monocyte chemoattractant protein-1 (p < 0.001 for all); pioglitazone reduced interleukin-6, tumoral necrose factor-alpha, resistin and matrix metalloproteinase-9 (p < 0.001 for all). Simvastatin + pioglitazone treatment further reduced plasmatic variables, including interleukin-6, tumoral necrose factor-alpha, resistin, asymmetric dimethylarginine and metalloproteinase-9 vs. the control group (p < 0.001). Higher plasma adiponectin and lower high sensitivity C-reactive protein concentrations were found simultaneously in the combined treatment group. A positive correlation between the mean percentage systemic and tissue cytokines was observed after treatments. T- and B-lymphocytes and macrophages clusters were observed in the fat fragments of patients treated with simvastatin for the first time.

CONCLUSIONS

Pioglitazone, simvastatin or combination treatment substantially reduced EAT and plasma inflammatory markers in CAD and MS patients. These tissue effects may contribute to the control of coronary atherosclerosis progression.

Do Archaea and bacteria co-infection have a role in the pathogenesis of chronic chagasic cardiopathy?

Chronic cardiopathy (CC) in Chagas disease is a fibrotic myocarditis with C5b-9 complement deposition. Mycoplasma and Chlamydia may interfere with the complement response. Proteolytic enzymes and archaeal genes that have been described in Trypanosoma cruzi may increase its virulence. Here we tested the hypothesis that different ratios of Mycoplasma, Chlamydia and archaeal organisms, which are frequent symbionts, may be associated with chagasic clinical forms.

MATERIALS AND METHODS

eight indeterminate form (IF) and 20 CC chagasic endomyocardial biopsies were submitted to in situ hybridization, electron and immunoelectron microscopy and PCR techniques for detection of Mycoplasma pneumoniae (MP), Chlamydia pneumoniae(CP), C5b-9 and archaeal-like bodies.

RESULTS

MP and CP-DNA were always present at lower levels in CC than in IF (p < 0.001) and were correlated with each other only in CC. Electron microscopy revealed Mycoplasma, Chlamydia and two types of archaeal-like bodies. One had electron dense lipid content (EDL) and was mainly present in IF. The other had electron lucent content (ELC) and was mainly present in CC. In this group, ELC correlated negatively with the other microbes and EDL and positively with C5b-9. The CC group was positive for Archaea and T. cruzi DNA. In conclusion, different amounts of Mycoplasma, Chlamydia and archaeal organisms may be implicated in complement activation and may have a role in Chagas disease outcome.

Particulate emboli capture by an intra-aortic filter device during aortic valve replacement

OBJECTIVE

This study aims to analyze the embolic activity in patients with calcified aortic stenosis who underwent aortic valve replacement using intra-aortic filtration with an EMBOL-X System device (Edwards Lifesciences Inc., Mountain View, CA, USA).

METHODS

From January 2007 to July 2007, 13 consecutive patients with calcified aortic stenosis, who underwent isolated aortic valve replacement using intra-aortic filtration by an EMBOL-X System for 5 minutes after aortic clamp release, were evaluated. Mean patient age was 63.7 years (range 34 to 79 years) and 61.5% were female. The mean bypass time was 60.2 +/- 7.5 minutes (range 45 to 72 minutes) and the mean cross-clamp time was 50 +/- 7.5 minutes (range 35 to 63 minutes). Following removal, each filter was fixed in formalin and analyzed macroscopically with the captured fragments being counted. Histological examinations of the captured material were performed.

RESULTS

There were no strokes or gross neurological events. There were no cases of postoperative renal failure. No deaths were reported during hospitalization. Particulate emboli were found in five (38.5%) of the filters. On histological analysis of the particulate emboli captured, two (40%) contained fibrin, two (40%) presented conjunctive tissue, one (20%) contained red blood cells and in one it was not possible to determine the nature of the particulates captured.

CONCLUSION

The EMBOL-X System device was effective in particulate emboli capture in aortic valve replacement surgery of patients with calcified aortic stenosis.

Clinical, electrocardiographic and echocardiographic findings in significant cardiac amyloidosis detected only at necropsy: comparison with cases diagnosed in life

BACKGROUND

Currently, many cases of heart amyloidosis still fail to be diagnosed.

OBJECTIVE

To disclose factors related to the difficulty in attaining the diagnosis of cardiac amyloidosis.

METHODS

We compared the clinical, electrocardiographic and echocardiographic data of 17 patients in whom amyloidosis was diagnosed only at the necropsy (group I) with data from 9 patients in whom the disease was diagnosed in life (group II). The quantitative variables were compared by t-test and qualitative ones by Fisher's exact test. Significance was set at p< or = 0.05.

RESULTS

The two groups showed differences regarding age (group I: 75.29 +/- 11.61, group II: 58.67 +/- 11.07 years), association with other cardiac disease (group I: 52.94%, group II: 0%), low voltage at the ECG (group I: 17.65%, group II: 66.67%), and diastolic dysfunction at the echocardiogram (group I: 7.69%, group II: 62.50%). Some degree of left ventricular thickening was found in 75% of necropsy cases and 100% of controls (p=0.23), but wall thickness was lower in group I (free left ventricular wall: 1.20 +/- 0.28 cm versus 1.53 +/- 0.18 cm in group II, p=0.01). Systolic dysfunction was present in 57.89% of the cases, without significant difference between the groups.

CONCLUSION

Amyloidosis is diagnosed when the clinical, ECG, and echocardiogram patterns are "typical", but most of the cases fail to be diagnosed, especially in elderly people, due to the association with other cardiac diseases, lack of diastolic dysfunction at the echocardiogram and only a slightly thickened ventricular wall.

Cardiac Magnetic Resonance in Chagas' Disease

American trypanosomiasis (Chagas' disease [CD]) caused by Trypanosoma cruzi is endemic in Latin America, where it is one of the leading causes of death. The involvement of the heart is crucial in the patients' prognosis. Besides lymphocytic myocarditis, cardiomyopathy is associated with several degrees of myocardial fibrosis (MF). Myocardial delayed enhancement by cardiac magnetic resonance (CMR) has been considered the most accurate method to detect MF in ischemic and nonischemic cardiomyopathy, including Chagas' heart disease. Additionally, CMR offers a wide variety of imaging tools to evaluate in detail morphology, the function and other tissue characterization abilities, such as detection of edema and fat. The present article aims to discuss the current clinical applicability of CMR to evaluate CD. We also discuss its future as a screening tool for very early myocardial involvement, which would allow the investigation of new therapeutic methods with potential influence in the natural history of CD.

Influence of chronic liver disease on coronary atherosclerosis vulnerability features

INTRODUCTION

A lower incidence of acute myocardial infarction was reported in patients with chronic liver disease.

OBJECTIVE

To analyze the impact of chronic liver disease on characteristics associated with vulnerability of human coronary artery atherosclerotic plaques.

METHODS

One hundred fourteen hearts were collected from 3 groups of individuals: A--38 chronic liver disease patients who died while on the waiting list for liver transplantation; B--38 individuals who died of natural causes; and C--38 individuals who died of accidental causes. The most obstructed portion of the initial 2-cm segment of coronary arteries was histologically evaluated regarding to plaque area, luminal area, inflammation, percentage of fat, and total vessel area.

RESULTS

The mean age (years) and male frequency in groups A, B and C were, respectively, 52+/-9 and 79%; 52+/-11 and 71%; and 54+/-18 and 89%. The mean area of the plaque and the incidence of severe plaque inflammation in group A were significantly lower (4.2+/-3.2; 13.2%) than those in the other two groups (6.6+/-4.3; 84.2%, and 6.3+/-4.4; 52.6%) p<0.01. The cross-sectional vessel measures were not statistically different regarding to vessel area (10.5+/-4.6; 12.1+/-4.6; 13.0+/-4.4) p=0.08, luminal obstruction (45%+/-15%; 60%+/-20%; 53%+/-20%) p=0.07, and fat area in the plaque (16%+/-17%; 30%+/-24%; 18%+/-18) p=0.37. In conclusion, compared with the general population, chronic liver disease patients have coronary arteries with smaller intimal plaque and less vessel inflammation. These findings favor the concept that hepatic disease patients are less prone to develop complicated coronary atherosclerosis.

Bradykinin B2receptor antagonism attenuates inflammation, mast cell infiltration and fibrosis in remote myocardium after infarction in rats

Bradykinin may interfere with myocardial remodelling by promoting inflammation and mast cell activation or, alternatively, by counteracting angiotensin II-dependent collagen accumulation. The aim of the present study was to investigate the role of bradykinin B2 receptor antagonism in inflammatory and mast cell infiltration, fibroplasia and fibrosis accumulation following myocardial infarction (MI). Myocardial infarction was produced by the ligature of the left coronary artery in male Wistar rats that were 10 weeks of age. Immediately after MI, rats received the B2 receptor antagonist Hoe140 (0.5 microg/kg per min, s.c.) or saline over a period of 3 days, 1 week or 4 weeks, constituting three separate groups and their respective controls. Coronal myocardial tissue sections underwent haematoxylin and eosin, Giemsa and picrosirius red staining, as well as immunohistochemistry for alpha-smooth muscle actin (SMA). Morphometric studies were undertaken in three different myocardial regions: MI, remote non-infarcted subendocardium (non-MI SE) and remote non-infarcted interventricular septum (non-MI IVS). The MI size was comparable between Hoe140-treated groups and their respective controls (day 3: 42 +/- 4%, n = 8, vs 43 +/- 3%, n = 6; week 1: 37 +/- 5%, n = 5, vs 39 +/- 2%, n = 5; week 4: 35 +/- 3%, n = 9, vs 36 +/- 3%, n = 7). At day 3, Hoe140 treatment reduced inflammatory cell reaction within the MI (585 +/- 59 vs 995 +/- 170 cells/mm2; P = 0.02), non-MI SE (77 +/- 12 vs 214 +/- 57 cells/mm2; P = 0.02) and non-MI IVS (93 +/- 16 vs 135 +/- 14 cells/mm2; P = 0.03) regions. Mast cells were reduced within the non-MI IVS region (0.8 +/- 0.1 vs 2.5 +/- 0.4 cells/mm2; P = 0.006), but not within the MI region. In non-MI SE, mast cells were rarely found. At week 1, Hoe140 treatment reduced alpha-SMA-positive myofibroblast infiltration within the MI (2535 +/- 383 vs 5636 +/- 968 cells/mm2; P = 0.01) and non-MI SE (222 +/- 33 vs 597 +/- 162 cells/mm2; P = 0.03) regions. In the non-MI IVS region, alpha-SMA-positive myofibroblasts were rarely found. At week 4, Hoe140 treatment reduced collagen volume fraction within the MI (37 +/- 4 vs 53 +/- 4%; P = 0.03), non-MI SE (1.3 +/- 0.2 vs 2.6 +/- 0.3%; P = 0.001) and non-MI IVS (1.1 +/- 0.2 vs 1.8 +/- 0.2%; P = 0.01) regions. Bradykinin promotes inflammation, fibroplasia and fibrosis after MI. Mast cells may have a role in fibrosis deposition through a bradykinin-related mechanism.

Different patterns of atherosclerotic remodeling in the thoracic and abdominal aorta

PURPOSE

To investigate the relationship between the vascular diameter and the extent and histologic characteristics of atherosclerosis in the thoracic and abdominal aortas of patients who died of atherosclerotic disease.

METHOD

We measured the vascular diameter and evaluated the percentage atrophy of the medial layer of the thoracic and abdominal aortas of 19 patients who died due to atherosclerotic disease. The extent of plaques, calcification, ulceration, thrombosis, and the amount of fat in the plaques were evaluated semiquantitatively.

RESULTS

Atherosclerosis was more severe in the abdominal than the thoracic aorta as indicated by the higher sum of the macroscopic scores (P = .02) and the higher percentage atrophy of the medial layer (P < .001). The diameter of the thoracic, but not of the abdominal aorta, correlated with age (r = 0.56; P = .01), plaque score (r = 0.59; P = .008), calcification score (r = 0.749; P < .001), and fat score (r = 0.48; P = .04). Multiple linear regression showed that age (P = .06) and calcification score (P = .001) were the parameters with the strongest association to thoracic aorta diameter.

CONCLUSION

There are some differences regarding atherosclerosis in the thoracic compared to the abdominal aorta. Progressive thoracic aorta atherosclerosis is associated with fat deposition in the plaques, inducing arterial dilation. In the abdominal aorta, atherosclerosis can either have a similar evolution or be associated with less fat deposition in the arterial wall, which would result in more rigidity, hindering compensatory arterial enlargement.

Polymerase chain reaction in endomyocardial biopsies for monitoring reactivation of Chagas' disease in heart transplantation

Polymerase chain reaction (PCR) has been used to detect microbiological agent recurrence after heart transplantation of viral-induced cardiomyopathies. We report a case of reactivation of Chagas' disease after heart transplantation in which parasites could be detected in the endomyocardial biopsy using hematoxylin-eosin-stained sections, immunohistochemistry, and PCR for Trypanosoma cruzi DNA. Interestingly, PCR results remained positive in the endomyocardial biopsy 53 days after the beginning of successful treatment, pointing to the possibility of chronic persistence of parasites in the myocardium after the reactivation of Chagas' disease.

[Chlamydia pneumoniae and Mycoplasma pneumoniae in calcified nodes of stenosed aortic valves]

OBJECTIVE

We investigated whether Chlamydia pneumoniae (CP) and Mycoplasma pneumoniae (MP) are present in aortic valve stenosis (AS).

METHODS

Immunohistochemistry was utilized to identify CP antigens, in situ hybridization to identify MP DNA, and electron microscopy was used to evaluate the following three groups: Normal - 11 normal autopsy valves; Atherosclerosis - 10 autopsy valves from patients with systemic atherosclerosis and no AS; and AS - 14 surgical specimens of AS analyzed in 3 sub-regions: AS-Preserved - peripheral, preserved regions; AS-Fibrosis - peri-calcified fibrotic tissue; and AS-Calcification - calcified nodules.

RESULTS

The positive area fraction of CP antigen median values were 0.09, 0.30, 0.18, 1.33, and 3.3 in groups Normal, Atherosclerosis, AS-Preserved, AS-Fibrosis, and AS-Calcification, respectively. CP density was significantly greater in Atherosclerosis and AS-Calcification than in Normal (P<0.05). Within the AS group, the amount of CP was greater in the Calcification and Fibrosis regions (P<0.05). MP-DNA positive area fraction (median values) were 0.12, 0.44, 0.07, 0.36, and 1.52 in groups Normal, Atherosclerosis, AS-Preserved, AS-Fibrosis, and AS-Calcification, respectively. The amount of MP-DNA was greater in AS-Calcification than in Normal (P<0.05). Within the AS group, MP-DNA was in larger quantity in the Calcification and Fibrosis regions (P<0.05).

CONCLUSION

AS Calcified nodes present higher concentration of CP and MP suggesting that these bacteria may be associated with the development of calcification and inflammation. This adds novel similarities between AS and the atherosclerosis process, which may have infection mechanisms involved.

Density of Chlamydia pneumoniae is increased in fibrotic and calcified areas of degenerative aortic stenosis

BACKGROUND

The process of aortic degeneration associated with calcified aortic stenosis shares many similarities with coronary artery atherosclerosis. Inflammation and infection are involved in both diseases. Chlamydia pneumoniae has been identified in atherosclerotic plaques. However, the studies about the presence of C. pneumoniae in degenerative aortic stenotic valves are not conclusive.

OBJECTIVE

We investigated whether an association exists between the density of C. pneumoniae and fibrosis or calcification in aortic stenosis.

DESIGN

Autopsy and surgical specimens were divided into 3 groups: Normal, 11 normal autopsy valves Atherosclerosis, 10 autopsy valves from patients with systemic atherosclerosis and no aortic stenosis and Aortic stenosis, 14 surgical specimens of aortic valves replaced due to aortic stenosis.

SETTING

Heart Institute (InCor), University of São Paulo Medical School.

PATIENTS

Aortic valves from patients aged 52+/-16 years, 69+/-9 years, and 71+/-8 years.

INTERVENTION

Specimens were evaluated by immunohistochemical technique (to detect C. pneumoniae antigens), in situ hybridization, and electron microscopy (to quantify the density of C. pneumoniae in the valves).

MEASUREMENTS

The aortic stenosis group was analyzed according to 3 subregions: aortic stenosis-preserved, peripheral preserved regions; aortic stenosis-fibrosis, peri-calcified fibrotic tissue; and aortic stenosis-calcification, calcified nodules.

RESULTS

The median values of C. pneumoniae antigens were 0.09, 0.30, 0.18, 1.33, and 3.3 in groups Normal, Atherosclerosis, Aortic stenosis-preserved, Aortic stenosis-fibrosis, and Aortic stenosis-calcification, respectively. The amount of C. pneumoniae was greater in the Atherosclerosis and Aortic stenosis-calcification groups than in the Normal group (P<0.05). C. pneumoniae was greater in the Aortic stenosis group in the calcified and fibrotic regions than in preserved region (P<0.05).

CONCLUSION

An association was found between the higher density of C. pneumoniae and fibrosis/calcification in stenotic aortic valves.

Trypanosoma cruzi trans-sialidase as a new therapeutic tool in the treatment of chronic inflammatory diseases: possible action against mycoplasma and chlamydia

The present paper proposes a new therapy using Trypanosoma cruzi trans-sialidase to treat diseases with unclear pathogenesis that present in common chronic inflammation and fibrosis. This hypothesis is based on recent findings that co-infection with mycoplasma and chlamydia is present in many of these diseases and that this enzyme was capable to eliminate or decrease the co-infection from the host. We identified that mycoplasmas and chlamydias are present in atherosclerosis, aortic valve stenosis, dilated cardiomyopathy, chronic chagasic myocarditis and cancer. We hypothetized that mycoplasmal infection may induce immunodepression in the host, favoring proliferation of pre-existent chlamydial infection and that elimination of mycoplasma would lead to improvement of the immune system resistance and the control of chlamydial proliferation. Mycoplasma has a particular parasitic relationship with host cells, involving strong adherence of their membranes, making it extremely difficult to eradicate mycoplasmal infection from the host. A new therapeutic approach is suggested using one or more agents that prevent or inhibit the adherence of mycoplasma to host cell membranes by removing sialic acid residues and preventing oxidation of the cells. The use of a neuraminidase enzyme, particularly the T. cruzi trans-sialidase enzyme, associated with treatment using anti-oxidating agents is proposed. Preliminary experimental animal and laboratory tests showed good results. The proposal that trans-sialidase from T. cruzi is efficient in combating co-infection of mycoplasma and chlamydia is based, at least in part, on the observation that chagasic patients suffering from T. cruzi infection present less mycoplasma and chlamydia infection in their tissues. Also, a lower incidence of the diseases above described to be related to mycoplasma infection is observed in chagasic patients. It is also hypothesized that co-infection with mycoplasma and chlamydia may induce oxidation of the host cells. Anti-oxidants such as those present in plant extracts may also be used in the treatment. Other diseases such as chronic hepatitis, glomerulonephritis, Multiple Sclerosis, Alzheimer's Syndrome and idiopathic encephalitis are other examples of chronic diseases where mycoplasma and chlamydia might be present, as they have the characteristics of unknown etiology, persistent chronic inflammation and fibrosis.

Decreased numbers of T-lymphocytes and predominance of recently recruited macrophages in the walls of peripheral pulmonary arteries from 26 patients with pulmonary hypertension secondary to congenital cardiac shunts

INTRODUCTION

In the primary form of pulmonary hypertension (PH), the involvement of inflammation in the physiopathology of the vascular lesions is well established. Its role in secondary PH is yet to be investigated. We quantified the inflammatory cells on the walls of peripheral pulmonary arteries from patients with congenital heart shunts.

METHODS

Twenty-six lung biopsies from patients with increased pulmonary flow and 10 lung fragments from control participants were examined. B-lymphocytes (CD20), T-lymphocytes (CD3), recently recruited macrophages (MAC387) and granulocytes (CD15) were quantified by area of the adventitia in arteries >50 microm. An index of inflammatory cells infiltrating the medial and intimal layers was also determined.

RESULTS

There was no difference in the sum of densities of adventitial inflammatory cells between the groups. A prevalence of MAC387-labeled cells was detected in the PH group and of CD3-labeled cells in the controls. There was a lower density of T-lymphocytes in the PH group (P<.004). Patients with intimal proliferative lesions showed prevalence of MAC387-labeled cells (P=.004). PH participants showed a higher index of MAC387-labeled cells infiltrating the arterial medial and intimal layers (P<.001).

CONCLUSION

The predominance of recently recruited macrophages in the PH group is compatible with ongoing inflammatory reaction in the arterial walls. This could be related to the pathogenesis of the vascular lesions, as a consequence of cytokines produced by the inflammatory cells. The smaller number of adventitial T-lymphocytes in patients with congenital shunts can reflect an impairment of their immune response.

Sequential histologic analysis of the myocardium after dynamic cardiomyoplasty: A study based on right ventricular endomyocardial biopsies

Although dynamic cardiomyoplasty may promote clinical amelioration and mild improvement in left ventricular function in selected patients, whether cardiac reverse remodeling occurs after the procedure is not clear. We did not find histologic differences among right ventricular endomyocardial biopsy specimens taken before and after the surgery at 3 time periods. This result suggests that the procedure has no effect on the microscopic structure of the right ventricular myocardium. However, because reverse remodeling does not necessarily occur concomitantly in both ventricles, our conclusion cannot be extrapolated to the left ventricular chamber.

Thyroid hormone levels in patients with aortic dissection: comparison with controls and correlation with the percentage of the aortic media composed of myxoid deposits

OBJECTIVE

Deposits of myxoid material, similar to myxedema related to thyroid disease, are described in the medial layer of aortas with dissection. We analyzed the clinical or subclinical thyroid dysfunction of patients with this disease and analyzed whether a correlation exists between serum levels of thyroid-related hormones and the myxoid content of the aortic media.

METHODS

We measured, with standard methods, serum levels of triiodothyronine (T3), thyroxine (T4), and thyroid stimulating hormone (TSH) in 28 patients who underwent aortic dissection and free T4 in 20 of them. The same hormones were quantified in 20 control patients matched by sex and age. Results were compared by using the Mann-Whitney test. We also measured the percentage of the aortic media occupied by myxoid material in the surgical specimens of 25 of the patients with aortic dissection and analyzed its correlation with hormone levels by using the Pearson test.

RESULTS

In the 20 pairs in which the amount of hormones was compared, the mean values for T3, T4, free T4, and TSH were 1.22ng/mL, 9.89mcg/dL, 1.18ng/dL, and 5.45 microIU/mL in study patients and 1.15ng/mL, 8.57mcg/dL, 1.32ng/dL, and 2.15 microIU/mL in controls. Neither these differences nor the correlation between the percentage of myxoid content (mean=30%) and the values for T3, T4, free T4, and TSH (mean 1.22ng/mL, 9.44mcg/dL, 1.20ng/dL, and 5.08 microIU/mL, respectively; n= 25) were significant.

CONCLUSION

Our data suggest that serum levels of thyroid hormones have no relation with the myxoid content in the aortic media in cases of aortic dissection.

Pathophysiology of the heart in Chagas' disease: current status and new developments

In the present review we have summarized remarkable historical data on Chagas' disease studies putting special emphasis on histopathological findings and pathogenetic theories as well as recent discoveries based on the use of advanced modern technologies in pathology and immunology. A unified theory that links almost all of these findings is proposed. Chronic cardiac Chagas' disease represents the result of a close interaction between the host and the parasite, causing different clinical pictures: patients with an efficient immune response may adequately circumvent the parasitic infection and the individual will develop the indeterminate form. Deficient immune response of the host and/or a high initial parasitemia favor an immune imbalance that might lead to development of a permanent inadequate immunological response against the parasite. The inflammatory response, which is probably recurrent, undergoing periods of more accentuated exacerbation, is most likely responsible for progressive neuronal damage, microcirculatory alterations, heart matrix deformations and consequent organ failure.

Left ventricular remodeling in hearts with tricuspid atresia: morphologic observations and possible basis for ventricular dysfunction after surgery

OBJECTIVES

This study was undertaken to assess the pattern of left ventricular hypertrophy, the myocardial capillary network, and the extracellular matrix in hearts with tricuspid atresia.

METHODS

We examined 32 hearts with tricuspid atresia and 27 normal hearts from control subjects with similar age and sex distribution. Wall thickness, inlet length, and outlet length were obtained from the left ventricle. Immunohistochemical staining for von Willebrand factor was used to label myocardial capillaries. By means of computer-assisted morphometry, the following data were obtained from the inlet, apex, and outlet of the left ventricle: transverse myocyte diameter, myocyte nuclear volume fraction, capillary volume fraction, interstitial fibrous volume fraction, and endocardial thickness.

RESULTS

The wall thickness in affected hearts was not different from that in control hearts. The left ventricular outlet length was significantly greater in the malformed hearts (P =.005). The myocyte diameter did not differ from that in control hearts. The capillary volume fraction was decreased in the malformed hearts (P <.001). The interstitial fibrous deposition was greater in the malformed hearts at all sites analyzed (P <.001). Fibrosis was greater in the inlet and apex (P =.004) and also in the subendocardial half of the ventricular wall than in the subepicardial half. According to a logistic regression model, age was the only variable associated with the probability of occurrence of fibrosis.

CONCLUSIONS

Our findings in hearts with tricuspid atresia possibly represent chronically induced volume overload in the presence of ischemia, rather than a typical model of volume overload. A decreased capillary volume fraction may indicate a greater susceptibility to ischemia. Fibrous deposition probably occurs early in life.

[Anatomo-clinical correlation. Case 4/2003 - A 61 year-old patient Chagasic woman, with ventricular dysfunction, recurrent ventricular tachycardia and cardiac pacemaker, presented asystole after surgical resection of apical aneurysm]

A 61 year-old Chagasic woman, with previous left ventricular systolic disfunction, ventricular tachychardia and cardiac pacemaker, presented cardiac arrest in asystolia after surgical ressection of apical aneurysm.

Coinfection with Mycoplasma pneumoniae and Chlamydia pneumoniae in ruptured plaques associated with acute myocardial infarction

OBJECTIVE

To study atheromas, Mycoplasma pneumoniae (M. pneumoniae), and Chlamydia pneumoniae (C. pneumoniae).

METHODS

C. pneumoniae was studied with immunohistochemistry and M. pneumoniae with in situ hybridization (ISH), in segments of coronary arteries (SCA) as follows: group A - thrombosed ruptured plaques (TRP) of 23 patients who died due to acute myocardial infarction (AMI); group B - 23 nonruptured plaques (NRP) of group A patients; group C - NRP of 11 coronary patients who did not die due to AMI; and group D - 11 SCA from patients with dilated cardiomyopathy or Chagas' disease without atherosclerosis.

RESULTS

The mean number of C. pneumoniae+ cells/400x in groups A, B, C, and D was, respectively, 3.3 +/- 3.6; 1.0 +/- 1.3; 1.2 +/- 2.4; and 0.4 +/- 0.3; and the percentage of M. pneumoniae area was, respectively, 3.9 +/- 3.5; 1.5 +/- 1.6; 0.9 +/- 0.9; and 0.4 +/- 0.2. More M. pneumoniae and C. pneumoniae were found in of group A than in group B (P<0.01). Good correlation was seen between the area of the vessel and the M. pneumoniae area in the plaque (r = 0.46; P=0.001) and between C. pneumoniae+ cells and CD4+ T lymphocytes (r = 0.42; P<0.01). The number of C. pneumoniae+ cells correlated with CD20+ B cells (r=0.48; P<0.01).

CONCLUSION

M. pneumoniae and C. pneumoniae are more frequently found in TRP correlate with the intensity of the inflammation and diameter of the vessel (positive remodeling).

Coinfection of laboratory rats with Mycoplasma pulmonis and Chlamydia pneumoniae

Routine examinations of conventional outbred Wistar rats in our laboratory showed increased serum levels of alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, and urea. Electron microscopy and specific reactions showed C. pneumoniae and M. pulmonis in lung, liver, spleen, heart, and kidney sections. We could not exclude the fact that other infectious microorganisms detected through routine health surveillance affected the Wistar rat colony; however, we have not identified any of those microorganisms by electron microscopy of the organs listed. Natural coinfection of C. pneumoniae and M. pulmonis can occur in laboratory rats and is associated with histopathological and functional compromise of many organs. Further studies comparing different conventional animals and specific pathogen-free animals are necessary to better understand the present findings and to define whether coinfection influences the results of experimental studies with rats.

Implication of transforming growth factor-beta1 in Chagas disease myocardiopathy

Cardiac dysfunction with progressive fibrosis is a hallmark of Chagas disease. To evaluate the involvement of transforming growth factor (TGF)-beta1 in this disease, TGF-beta1 levels in patients were measured at 3 stages: asymptomatic indeterminate (IND), cardiac with no or slight heart dysfunction (Card 1), and cardiac with moderate or severe heart dysfunction (Card 2). All patients had significantly higher circulating levels of TGF-beta1 than did healthy persons, and 27% of patients in the Card 1 group had higher TGF-beta1 levels than did patients in the IND group. Immunohistochemical analysis of cardiac biopsy specimens showed strong fibronectin staining in the extracellular matrix and staining for phosphorylated Smad 2 (activation of the TGF-beta1 signaling pathway) in cell nuclei. The higher levels of latent TGF-beta1 observed in patients with myocardiopathy, together with intracellular activation of the TGF-beta1 pathway and tissue fibrosis, suggest that TGF-beta1 plays an important role in Chagas disease. TGF-beta1 may represent a new target for preventive and curative treatments of Chagas disease.

Infectious agents in coronary atheromas: a possible role in the pathogenesis of plaque rupture and acute myocardial infarction

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.

Mycoplasma pneumoniae and Chlamydia pneumoniae in calcified nodules of aortic stenotic valves

Aortic Valve Stenosis (AVS) has been explained as an atherosclerotic process of the valve as they often exhibit inflammatory changes with infiltration of macrophages, T lymphocytes and lipid infiltration. The present study investigated whether the bacteria Chlamydia pneumoniae (CP) and Mycoplasma pneumoniae (MP), detected previously in atherosclerotic plaques, are also present in AVS. Ten valves surgically removed from patients with AVS were analyzed by immunohistochemistry, in situ hybridization, and electron microscopy. The mean and standard deviation of the percentage areas occupied by CP antigens and MP - DNA were respectively 6.21 +/- 5.41 and 2.27 +/- 2.06 in calcified foci; 2.8 +/- 3.33 and 1.78+/- 3.63 in surrounding fibrotic areas, and 0.21 +/- 0.17 and 0.12 +/- 0.13 in less injured parts of the valve. There was higher amount of CP and MP in the calcified foci and in the surrounded fibrosis than in more preserved valvular regions. In conclusion, the fact that there were greater amounts of CP and MP in calcification foci of AVS favors the hypothesis that AS is not an inevitable degenerative process due to aging, but rather that it may be a response to the presence of these bacteria, similarly to the morphology detected in atherosclerosis damage.

A possible role for complement in the pathogenesis of chronic chagasic cardiomyopathy

The membrane attack complex (MAC) of complement participates in several inflammatory and proliferative processes by releasing pro-inflammatory cytokines and growth factors from target cells. Chronic Chagasic cardiomyopathy (CCH) is a parasitic dilated cardiopathy, characterized by severe fibrosis and inflammation, which differs from idiopathic dilated cardiomyopathy (DCM). Trypanosoma cruzi, the pathogenic organism of CCH, is a strong complement activator and can also induce alternative pathway activation by mammalian cells. This study explored whether the myocardium in CCH patients has increased MAC deposition, an expression of complement activation, compared to DCM patients. MAC was semi-quantified in endomyocardial human samples (29 CCH subjects, 18 DCM subjects, and four controls) by immunohistochemistry. MAC was present in the sarcolemma of 38% of CCH, 5.5% of DCM (p<0.02), and 0% of controls, and in interstitial inflammatory cells of CCH. No difference was observed in the expression of the complement regulatory protein CD59, indicating that increased MAC deposition is likely to be the result of complement activation rather than decreased protection. It is proposed that the increased MAC deposition found in CCH, but not in DCM or controls, may help to explain the diffuse myocardial fibrosis and inflammation characteristic of the disease.

[Mycoplasma pneumoniae and Chlamydia pneumoniae are associated to inflammation and rupture of the atherosclerotic coronary plaques]

In this review we report recent findings of our lab showing that Mycoplasma pneumoniae and Chlamydia pneumoniae are present in higher amount, associated with adventitial inflammation and positive vessel remodeling, in thrombosed coronary artery segments (CAS) of patients who died due to acute myocardial infarction. CD8T cell was the predominant lymphocytes in the plaque and CD24(B) cell in the adventitia. The mean numbers of lymphocytes were significantly higher in adventitia than in the plaque. Vulnerable plaques were usually associated with focal positive vessel remodeling and large lipidic atheromas. Mycoplasma is the only bacterium that needs cholesterol for proliferation. We hypothesized that the association of Mycoplasma pneumoniae and Chlamydia pneumoniae increases virulence of both bacteria, inducing inflammation and rupture of the plaque. The search of CMV and Helicobacter pylori resulted negative.