Hugo Carrasco - Academia.edu (original) (raw)

Papers by Hugo Carrasco

The American Journal of Tropical Medicine and Hygiene, 1999

The persistence of Trypanosoma cruzi tissue forms was detected in the myocardium of seropositive ... more The persistence of Trypanosoma cruzi tissue forms was detected in the myocardium of seropositive individuals clinically diagnosed as chronic chagasic patients following endomyocardial biopsies (EMBs) processed by immunohistochemical (peroxidase-anti-peroxidase [PAP] staining) and molecular (polymerase chain reaction [PCR]) techniques. An indirect immunofluorescent technique revealed antigenic deposits in the cardiac tissue in 24 (88.9%) of 27 patients. Persistent T. cruzi amastigotes were detected by PAP staining in the myocardium of 22 (84.6%) of 26 patients. This finding was confirmed with a PCR assay specific for T. cruzi in 21 (91.3%) of 23 biopsy specimens from the same patients. Statistical analysis revealed substantial agreement between PCR and PAP techniques (k ϭ 0.68) and the PCR and any serologic test (k ϭ 0.77). The histopathologic study of EMB specimens from these patients revealed necrosis, inflammatory infiltrates, and fibrosis, and made it possible to detect heart abnormalities not detected by electrocardiogram and/or cineventriculogram. These indications of myocarditis were supported by the detection of T. cruzi amastigotes by the PAP technique or its genome by PCR. They suggest that although the number of parasites is low in patients with chronic Chagas' disease, their potential for heart damage may be comparable with those present during the acute phase. The urgent necessity for testing new drugs with long-term effects on T. cruzi is discussed in the context of the present results.

The American Journal of Tropical Medicine and Hygiene, 2001

Inapparent infections of Trypanosoma cruzi were detected in symptomless seropositive people livin... more Inapparent infections of Trypanosoma cruzi were detected in symptomless seropositive people living in close proximity, and under the same conditions of risk, to patients with acute Chagas disease. Similar infections were also detected in sera samples of people from 25 villages of western Venezuela where Chagas disease is endemic. Seropositivity in all the 1,251 studied samples was established by use of 3 serological methods (direct agglutination test, indirect immunofluorescence antibody test, and enzyme-linked immunosorbent assay). Each seropositive sample was tested for detection of anti-T. cruzi-specific immunoglobulin (Ig) M and IgG levels and specific T. cruzi infection by molecular methodology (polymerase chain reaction assay). The combined analysis of the serologic (IgM and IgG levels), molecular (specific T. cruzi DNA), and statistical findings demonstrated the existence of a different stage of T. cruzi infection in asymptomatic patients, which is suggested to be recognized as inapparent infection. Its definition, significance, and comparison with typical Chagas disease phases are presented, and its potential epidemiological importance is discussed. * DAT ϭ direct agglutination test; ELISA ϭ enzyme-linked immunosorbent assay; IFAT ϭ indirect immunofluorescence antibody test; Ig ϭ immunoglobulin. † Became symptomatic 3 months after detection of inapparent infection.

International Journal of Cardiology, 1997

During the last 8 years 58 acute cases of Chagas' disease were studied. Patients from an ... more During the last 8 years 58 acute cases of Chagas' disease were studied. Patients from an endemic area of the state of Barinas, Venezuela, showed fever (98%) and circulating forms of T. cruzi (100%), and were treated with oral benznidazole. The recorded mortality was 8.6%. Acute myocarditis was constantly found either in myocardial biopsies or at necropsy, even in patients without any other sign of cardiac compromise (36%), which was detected by chest X-ray in 58%, by 2D echocardiography in 52%, by resting ECG in 41% and by clinical findings in 27.5% of the patients. Cardiomegaly was due to pericardial effusion rather than ventricular dilatation in most instances. Treatment eliminated parasitemia but negativized serology in only 20% of patients. It also appeared to have little influence on the ongoing myocarditic process, emphasizing the need for better therapeutic schedules, able to avoid or control the early appearance of immunologic mechanisms and microcirculatory damage involved in the future development of chronic chagasic myocarditis.

International Journal of Cardiology, 1983

Arquivos Brasileiros de Cardiologia, 2013

Background: In hypertrophic cardiomyopathy (HCM), the degree of left ventricular hypertrophy (LVH... more Background: In hypertrophic cardiomyopathy (HCM), the degree of left ventricular hypertrophy (LVH) could influence the development of ventricular arrhythmias. Objective: In HCM, analyze the association between the occurrence of ventricular arrhythmias on Holter electrocardiogram (Holter ECG) and the degree of LVH determined by maximum wall thickness (MWT) and mass index (MI) on echocardiography. Methods: Fifty-four consecutive patients with HCM underwent 24-hour Holter ECG and echocardiography for assessment of degree of LVH through MWT and MI. Two levels were established for the occurrence of ventricular arrhythmias: I-isolated or paired extrasystoles and II-non-sustained ventricular tachycardia (NSVT). Results: In 13 patients (24%) with NSVT (level II), there was a higher frequency of left ventricular (LV) MWT ≥ 21 mm (n = 10, 77%, 25 ± 4 mm) and LVMI≥144g/m² (n = 10, 77%, 200 ± 30 g/m²), in comparison with those presenting with only extrasystoles (level I) (n = 41, 76%), in which these measures were identified in, respectively, 37 % (n = 15, 23 ± 1 mm), p = 0.023, and 39% (n = 16, 192 ± 53 g / m²) of the cases p = 0.026. The cutoff values mentioned were determined by the ROC curve with a 95% confidence interval. NSVT was more common in patients with LVMWT ≥ 21 mm and LVMI ≥ 144 g/m² (8 of 13, 62%) than in those with one (4 of 13, 31%) or none (1 of 13; 8%) echocardiographic variables above cutoff values (p = 0.04). Conclusion: In HCM, the occurrence of ventricular arrhythmias on Holter-ECG was associated with the degree of LVH assessed by echocardiography through MWT and MI (Arq Bras Cardiol. 2013; 100(5):452-459).