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Biomedical subjects

S F de Oliveira

Publications and source records attributed to S F de Oliveira.

13 recordsLinked to original sources
PubMed1997

Sera from chronic chagasic patients with complex cardiac arrhythmias depress electrogenesis and conduction in isolated rabbit hearts.

BACKGROUND: Immune dysfunction has long been proposed as a mechanism for the etiopathogenesis of the chronic phase of Chagas' disease. Antibodies of chagasic patients have been shown to interfere with electric and mechanical activity of embryonic myocardial cells in culture. Here, we demonstrate that antibodies derived from a group of chronic chagasic patients are able to induce disturbances in the electrogenesis and conduction in isolated adult rabbit hearts. METHODS AND RESULTS: Sera from chronic chagasic patients with complex cardiac arrhythmias (ChA+) decreased heart rate (from 131+/-26 to 98+/-37 bpm [mean+/-SD]; n=6; P<.05) in isolated rabbit hearts when perfused at a dilution of 1:100 (vol:vol) by the Langendorff method. Sera from another experimental group of four chronic chagasic patients without complex arrhythmias (ChA-) and two control groups composed of five Wolff-Parkinson-White (WPW) syndrome patients and five orthopedic surgery patients did not affect heart rate when tested under similar conditions. In addition, sera from five of six ChA+ patients and from one WPW patient induced AV conduction blockade. Effects of the sera from ChA+ patients are due to their IgG fractions. Both serum and IgG effects are blocked by atropine (10 micromol/L). CONCLUSIONS: Antibodies of ChA+ patients decrease heart rate and induce AV conduction block in isolated adult rabbit hearts through activation of muscarinic receptors.

Adult↗
PubMed1993

Prognostic significance of silent myocardial ischemia after a first uncomplicated myocardial infarction.

Forty asymptomatic patients were studied after a first uncomplicated myocardial infarction. They were 36 men and 4 women, with a mean age of 52.6 yr; the location of myocardial infarction was in the anterior wall in 18 (45%) patients and in the inferior wall in 22 (55%). The patients were submitted to: (1) 48-h Holter monitoring, during the 2nd and 8th weeks after the acute event; (2) exercise testing during the same periods; (3) cardiac catheterization and coronary arteriography. Patients with clinical conditions associated with cardiac rhythm disturbances or repolarization abnormalities were excluded. The electrocardiographic methods identified 11 (27.5%) patients with silent myocardial ischemia. Patients with and without silent ischemia were similar in relation to sex, age, coronary risk factors, arrhythmias, left ventricular function and follow-up. Patients with silent ischemia had more inferior wall myocardial infarctions, but the difference was not statistically significant. Patients with silent ischemia had significantly more extensive coronary artery disease (45.5% multivessel disease) when compared to those without ischemia (14.8% multivessel disease) (p < 0.05). After a 2-yr follow-up, 4 (36.4%) patients with and 1 (3.4%) without silent ischemia had a coronary event (p < 0.05). Kaplan-Meier analysis demonstrated a significantly higher cumulative probability of not experiencing a new coronary event for the patients without silent ischemia (96.5%) as compared to those with silent ischemia (62.3%) (p < 0.01). Our results suggest that silent myocardial ischemia after a first uncomplicated myocardial infarction carries an adverse prognosis and should be routinely investigated.

Adult↗
PubMed1993

[Hemodynamic variable analysis in patients with systemic arterial hypertension undergoing physical exercise].

PURPOSE: To verify the exercise-induced hemodynamic changes in moderate hypertensive patients. METHODS: Twenty nine patients were studied and they were submitted to cycloergometer supine exercise (50w and 100w) during cardiac catheterization. The hemodynamic variables were measured: cardiac index (CI), stroke volume (SV), systemic arterial resistance (SAR), pulmonary arterial resistance (PAR), wedge pressure (WP), right atrial pressure (RA), systolic arterial pressure (SP), diastolic arterial pressure (DP), mean arterial pressure (MP) and heart rate (HR). To evaluate the cardiac function, the patients were divided in two groups: GI with CI > 2.5 ml/min/m2 and GII CI < 2.5 ml/min/m2. RESULTS: During exercise, patients from GI and GII were similar-according to MAP, RA, WP, and HR. On the other hand, GI and GII exhibited different (#) behavior regarding SV, PAR and SAR. During the three exercise conditions, rest (R), 50w and 100w it was observed: a) PAR-R = 50 = 100 (GI); b) MP, PAR, WP, SV, SAR-R #50 #100 (GI); c) HR, PAR and SAR-R #50 #100 (GII). There was no correlation between the cardiac function (CI, SV) and the circulatory adjustment (PAR and SAR) or the pressure curve (SP, DP, MP) and HR. CONCLUSION: The results suggest that the cardiac function of GI patients depends, mainly, on the inotropism, while in GII patients it depends on the decrease of the afterload (PAR and SAR). Those changes may appear even in the late exercise stage (100w), with a bias to attain the GI levels. Those observations suggest functional changes in vasomotor tone of GII patients.

Adult↗
PubMed1991

[Variability of the heart rate and silent ischemia after myocardial infarction].

PURPOSE: To show a possible relation between heart rate and silent myocardial ischemia. METHODS: Forty-nine ischemic episodes were registered in six patients during a total period of 576-hour Holter monitoring. Those patients were selected from a group of 40 asymptomatic individuals after a first uncomplicated myocardial infarction; 11 (27.5%) showed ischemia during daily activities or exercise, the six selected patients had myocardial ischemia on Holter monitoring. RESULTS: The silent episodes consisted 92% of the total ischemic burden; they lasted from 1 min 30 s to 20 min and the ST-segment depression varied from -1.1 mm to 3.3 mm. Thirty-five (72%) episodes occurred at rest or during light physical activities; nine (18.5%) occurred between 7:00 AM and 12:00 PM; eight (16.5%), between 12:00 PM and 6:00 PM; 17 (35%) between 6:00 PM and 12:00 AM and 15 (30%), between 12:00 AM and 7:00 AM. There was no significant change (more than 20%) in heart rate at the onset of ischemic episodes in relation to the heart rate 1 minute before (94.63 +/- 9.79 bpm and 99.47 +/- 10.99 bpm, respectively). Complex ventricular arrhythmias occurred in all patients and only one of them had an episode of nonsustained ventricular tachycardia related to silent ischemia. CONCLUSION: Our results suggest that there is no relation between heart rate, arrhythmias and silent ischemia.

Arrhythmias, Cardiac↗
PubMed1991

[Pseudoaneurysm of the left ventricle resected 20 years after acute myocardial infarction].

A 67 year-old-man suffered an uncomplicated myocardial infarction twenty years ago. By January 1990 an abnormal cardiac contour was noted on a chest radiography. Contrast ventriculography revealed a pseudoaneurysm of the left ventricle. The patient underwent open heart surgery and remains asymptomatic 12 months after surgery. This is the longest time interval between the myocardial infarction and successful surgery that has been reported.

Aged↗
PubMed1990

Organization of intermediate filaments and their association with collagen-containing phagosomes in mouse decidual cells.

We have analyzed the distribution of intermediate filaments (IF) in the cytoplasm of mature decidual cells of mice. IF were scattered throughout the cytoplasm of these cells although there was a preferential accumulation around the nuclei. In many cells a large area of the cytoplasm was occupied by a rich network of IF that extended from the perinuclear region toward the cell surface. Thin bundles of IF crossed the cytoplasm without a preferential orientation. IF were also seen in close association with nuclear pore complexes, gap junctions, mitochondria, and lysosomes. A very developed network of IF surrounded phagosomes that contained collagen fibrils. Longitudinal and cross sections of these phagosomes showed a very close association of IF with the phagosome membrane.

Animals↗
PubMed1990

[Severe pulmonary embolism in a single lung].

A 68 years old white man complaining of hemoptysis in the last 2 months was admitted for evaluation. He was a heavy smoker and thorax radiography as week as CT Scan showed a 5 cm mass in the right pulmonary hilum. Endoscopy with biopsy demonstrated an adenocarcinoma of middle lobe. He was operated on and a tumor was found in the middle lobe with invasion of the other two lobes and pericardium. A right pneumectomy was performed. In the 10th postoperative day the patient sustained a pulmonary thromboembolism. A pulmonary scintigraphy showed hypoperfusion of large areas of left lung. He was medically treated and had a good response. The patient was discharged in the 22nd postoperative day. Pulmonary thromboembolism in bowen more severe in patients with single lung, nevertheless the recovery of this patients was good with early diagnosis and treatment.

Adenocarcinoma↗
PubMedDate not supplied

The Awá-Guajá Indians of the Brazilian Amazon. Demographic data, serum protein markers and blood groups.

The South-American Indian group Awá-Guajá, currently living in the State of Maranhão (Northeastern Brazil), is one of the most recently contacted Indian groups of the Brazilian Amazon. This group is made up by three partially isolated villages named Awá, Guajá and Juriti, and is characterized by having a young population, in which 47.6% of the individuals range from 0 to 14 years old. The sex ratios (male/female) for people of reproductive age are 1.13 for Awá village, 2.00 for Guajá, 3.33 for Juriti and 1.61 for the tribe as a whole. Fst and heterogeneity analysis show that, despite the small differences observed among villages for the eight genetic systems analyzed, the Awá-Guajá tribe is constituted of only one population. Furthermore, comparisons between Awá-Guajá and Urubú-Kaapor tribes indicate that they are still isolated genetically, in spite of the fact that they share territories.

Adolescent↗