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Biomedical subjects

M Mendes

Publications and source records attributed to M Mendes.

At least 37 records · Page 2Linked to original sources
PubMed1995

[The evolution of the arterial pressure during a stress test in patients with hypertrophic myocardiopathy].

OBJECTIVES: To study the exercise blood pressure response in patients with hypertrophic cardiomyopathy (HC) and its relationship with sudden death. DESIGN: Retrospective study. POPULATION: We studied 51 patients (P) with HC: 18 women and 33 men. Their average age was 45 +/- 14 years, with a mean follow-up of 55 +/- 37 months. METHODS: Every patient had been subjected to a treadmill stress-test, a 24-hour Holter monitoring and an echocardiographic examination. Particular emphasis was given to blood pressure increments (BPI) during stress-test, the existence of premature ventricular contractions with a frequency of 10 or more per hour (PVC > or = 10), the occurrence of couplets (C) and/or non-sustained ventricular tachycardia (NSVT) on a 24-hour Holter. Finally, the finding of systolic anterior motion (SAM) of the mitral valve, in the routine echocardiogram, was valued. RESULTS: Four patterns of BPI were identified: "1": normal evolution (27 P); "2": plateau type increment (16 P); "3": fall in blood pressure during exercise (6 P); "4": abnormal BPI during recovery (2 P). Two groups were considered: group N-normal BPI, group A-patients with abnormal blood pressure responses. There were no significant differences among therapeutic agents, between the two groups, when the stress-test was performed. SAM was found in 21 P. Only 8 P registered ventricular arrhythmias, half of them with NSVT. No statistical relations were found between BPI and P age, the presence of SAM, PVC > or = 10, C, or NSVT. We found 78% of P in group N in NYHA class I. In contrast, in group A only 46% were in class I (p = 0.04). Only one death, of non cardiac cause, occurred (group A). CONCLUSIONS: There is a large number of patients with HC and abnormal BPI. This is, seemingly, not influenced either by a dynamic left ventricular gradient or by ventricular ectopic beat occurrence. However, a relation appears to exist between the abnormal response and functional class, not explained by the usual (noninvasive) clinical tests.

Adult↗
PubMed1994

[Does the modified Bruce protocol induce physiological stress equal to that of the Bruce protocol?].

OBJECTIVE: To determine if the physiological stress induced by the modification of Bruce protocol used in our hospital is equivalent to the original protocol. DESIGN: Retrospective analysis of clinical history, physical examination and stress test of apparently healthy individuals submitted to cardiac check up. SETTING: Outpatient private cardiological clinical. PARTICIPANTS: Sequential sampling of 80 individuals apparently healthy, submitted to cardiac check-up between April 1988 and September 1992. MATERIAL AND METHODS: Comparison of heart rate, blood pressure and double product progression, as well as time of exercise of individuals studied by the Bruce protocol (group A: n = 51) with the same data of individuals tested by the modified Bruce protocol (group B: n = 29). MEASUREMENTS AND MAIN RESULTS: The first stage of group A protocol provokes a superior physiologic stress than group B protocol, since there are bigger increments on heart rate (28.8 +/- 9.9 vs. 20.2 +/- 11.2 bpm; p < 0.01), blood pressure (27.0 +/- 11.3 vs. 14.3 +/- 11.4 mmHg; p < 0.0001) and, consequently, higher double products. In submaximal stages with the same speed and grade on the treadmill the hemodynamical stress is similar in both groups. At peak exercise, group A attains higher values on systolic blood pressure (197.1 +/- 9.5 vs. 188.8 +/- 10.4 mmHg; p < 0.001), double product (34330.4 +/- 2191.8 vs. 33060.9 +/- 2049.8; p = 0.01) and corrected exercise time also higher than estimated (929 +/- 91 vs. 818 +/- 94 sec; p = 0.02). It could be found that more individuals on group A (76% vs. 48%; p = 0.02) could complete the stage of 6.8 Km/h x 16% (stage IV on Bruce protocol and V on modified Bruce protocol. CONCLUSIONS: Modified Bruce protocol has a lighter initial increment, but decreases moderately the capacity of peak exercise due to peripheral fatigue secondary to the first stage of low intensity. Bruce protocol has a higher initial increment but permits to attain higher peak exercise intensities. Bruce protocol seems more adequate to individuals with good physical capacity and the modified Bruce protocol to individuals moderately limited in their functional capacity due to bad physical fitness or illness.

Adult↗
PubMed1993

[Nitrates in the treatment of chronic stable angina].

The use of nitrates in chronic stable angina is reviewed, with special emphasis on everyday clinical practice. The expectable benefits are referred, namely symptoms improvement and objective reduction os ischemia in the stress test and Holter monitoring. The use of nitrates in acute angina and in prophylaxis of chronic ischemia as well as their adverse effects are also discussed. Nitrates efficacy is compared against beta-blockers and calcium antagonists. In conclusion, nitrates have a moderate efficacy and should be used in association with other anti-ischemic drugs, in eccentrical therapeutical schemes with a free interval between doses.

Adrenergic beta-Antagonists↗
PubMed1993

[Prognosis in unstable angina as a function of the clinical presentation].

OBJECTIVE: To assess the prognosis of Unstable Angina according to its clinical presentation using Braunwald's Classification. DESIGN: Retrospective study of hospital admissions from January 1982 to September 1990. SETTING: Coronary Care Unit and a Cardiology Department of a Central Hospital. PATIENTS: There were 132 patients, 109 men and 23 women, with a mean age of 56 +/- 9 years, all submitted to cardiac catheterization at least 90 days after hospital admission followed up during 34.2 +/- 24.2 months. MATERIAL AND METHODS: Patients were divided in three groups according to the clinical presentation of Unstable Angina: Group A--Aggravated Chronic Angina and/or "De Novo" Angina; Group B--Angina at Rest but not in the last 48 hours, and Group C--Angina at Rest in the last 48 hours. Group A was also sub-divided, and the patients with Unstable Angina after myocardial infarction were excluded. The previous clinical profile was evaluated as well as the circumstances in which Unstable Angina occurred, need of Coronary Care Unit, angiographic findings and follow-up. RESULTS: Within the 132 patients, 86 were in the group A, (59 with Aggravated Angina and 27 with "De Novo" Angina), 11 in group B, and 35 in group C. The group with Aggravated Angina had higher incidence of previous myocardial infarction and bypass surgery (p < 0.01 and p = 0.05), compared to group with "De Novo" Angina and B, and also three vessels disease associated to ventricular dysfunction. "Culprit Lesion" appeared more frequently as eccentric type I in group A, and as concentric in group C. Revascularization procedures were performed in 95 patients (CABG in 66 and PTCA in 29) being respectively: 21 and 6 were urgent, 19 and 18 were elective and 26 and 5 were late procedures. CABG were more frequent in group A. There were 73 major cardiac events in 44 patients (8 deaths, 12 myocardial infarction and 53 new episodes of Unstable Angina), which were more frequent in group with Aggravated Angina and group C. The chance of patients with major cardiac events was in a 78 months follow-up, about 25% for group with "De Novo" Angina, 50% for patients with Aggravated Chronic Angina, and was greater than 75% in patients with Angina at Rest and episodes in the last 48 hours (p < 0.05)--Log-rank Test. The worse prognosis was seen in patients with Aggravated Chronic Angina, when a gathering of clinic patterns of Braunwald's classification were present. CONCLUSIONS: In summary, the group with Aggravated Angina and group C had more severe disease, required more urgent CABG and PTCA, and had also a higher incidence of cardiac events. The group with better prognosis was the group with "De Novo" Angina, which should be distinguished of the group with Aggravated Angina who was the worst prognosis.

Aged↗
PubMed1990

Comparison of the effects of a controlled-release formulation of isosorbide-5-mononitrate and conventional isosorbide dinitrate on exercise performance in men with stable angina pectoris.

Thirty-three men with stable exercise-induced angina pectoris entered a randomized, double-blind, crossover study in which controlled-release isosorbide-5-mononitrate 60 mg once daily was compared with conventional isosorbide dinitrate 20 mg 3 times daily. Each drug was given for 2 weeks. Twenty-eight patients completed the study and data on exercise variables are available in 23 patients. Treatment with either drug resulted in significant antianginal effects, when measured 6 hours after a single dose and after 2 weeks of therapy compared with baseline placebo; however, there were significantly fewer signs of myocardial ischemia during treatment with isosorbide-5-mononitrate. There was no evidence of tolerance to either drug treatment but a significant attenuation of resting blood pressure (but not of exercise blood pressure) was observed with both drugs. Headache was the only clinically significant adverse event during therapy and it occurred more frequently in the isosorbide dinitrate treatment group (p less than 0.05 vs placebo); 3 such patients had to withdraw from the study because of headache. Thus, once-daily, controlled-release isosorbide-5-mononitrate appears as effective as conventional isosorbide dinitrate 3 times daily in patients with stable angina pectoris. The once-daily administration is convenient and improves patient compliance.

Angina Pectoris↗
PubMed1990

[Effects of coronary surgery on silent ischemia].

In order to assess the effects of coronary artery bypass surgery on silent myocardial ischemia, we studied a group of 39 consecutive patients, 38 male and 1 female with a mean age of 56 + 7 years, with stable chronic angina pectoris, by 48 hours-Holter monitoring and maximal treadmill exercise test before and after operation. The reduction of angina was 92% (p less than 0.0001) and of ischemia 57% (p less than 0.0001) after operation. Silent myocardial ischemia was detected in 21 patients (54%) before operation, 13 by Holter, 4 by exercise test and 4 by the two methods. After operation 13 patients (36%) continue to have silent ischemia depicted in 7 by Holter and in 7 by exercise test. No new patient developed silent ischemia after operation. The group of patients with silent ischemia preoperatively was not significantly different from the group without silent ischemia based on clinical and angiographic characteristics, results of surgery and exercise test parameters with exception of ST segment depression. In conclusion, silent myocardial ischemia may persist after successful coronary artery bypass surgery for the relief of angina pectoris, and should be monitored by serial Holter recordings and treated medically, if its prognosis and consequences proved to be similar to manifest symptomatic ischemia.

Adult↗
PubMed1985

The functional and histological basis for graft-versus-host-induced immunosuppression.

The GvH reaction resulting from the injection of parental strain cells into adult F1 hybrids suppresses both cell-mediated and humoral immune responses and is dependent on the donor-host combination and the number of parental cells used to induce the GvH reaction. The early suppression is due, at least in part, to the increased number of macrophages and the activation of suppressor macrophages which act directly on the T-helper cell and perhaps the B-cell as well. The macrophage suppression is associated with an increase in PGE production. The long-term T-cell immunodeficiency is mediated by GvH-induced thymic dysplasia resulting in a block or an arrest in T-cell differentiation and deficient IL-2 production. The B-cell immunodeficiency is associated with both a decrease in B-cell production from lymphoid progenitors and a decrease in CFU-s production. The GvH reaction induces 2 types of thymic lesion, a stress-related effect causing atrophy of the thymic cortex and a cytolytic process causing severe-to-moderate lesions in the thymic medulla as a consequence of injury to medullary epithelial cells and a loss of Hassall's corpuscles (thymic dysplasia). By employing the NK-cell-deficient beige mutation, it was shown that the severe-to-moderate thymic medullary lesions occurred in F1 mice only in those transplant situations in which the donor inoculum was of the +/bg genotype, regardless of the genotype of the recipient. It is proposed that activation of parental T cells may contribute to the early immunosuppressive events; however, the relatively permanent immunosuppression appears to be associated with NK-like effector cells which are capable of causing injury to lymphoid and epithelial tissue, especially epithelium of the thymic medulla. These studies raise the possibility that the GvH reaction may contribute to some T- and B-cell immunodeficiencies observed in the SCID and AIDS syndromes, as well as in patients following bone marrow transplantation.

Animals↗
PubMed1980

Susceptibility of brain and skin to bacterial challenge.

The brain is a uniquely protected organ. Once the protective barriers are overcome, the brain is susceptible to bacterial infection. Using a reproducible rat model, the susceptibility of brain tissue to challenge by S. aureus or E. coli was quantitatively compared to that of skin. Brain was significantly more susceptible to the presence of bacteria than was the skin of the scalp. The development of infection in skin required at least 10(5) organisms, while brain infection could be produced with as few as 100 organisms.

Animals↗
PubMed1979

Production of experimental brain abscess in the rat.

Experimental evaluation of brain abscess has been inhibited by the lack of a simple and reproducible model in small animals. A stereotaxic headholder and slow infusion of 1 microliter of saline, containing a known number of bacteria, were used to produce brain abscess consistently in the rat. The natural history of the brain abscess produced by this technique closely simulated that found in the human clinical situation.

Animals↗
PubMed1977

Persistence of in vitro lymphocyte response to tuberculin skin test negative children immunized with BCG in infancy.

PPD stimulated lymphocyte reactivity was tested in 119 children aged 11 to 12 years. The lymphocyte responses was evaluated by measuring the extent of tritiated thymidine incorporation by cultured cells. In a group of sixty-four tuberculin negative children who had been BCG vaccinated in the neonatal period, lymphocyte response was significantly greater than in a group of non-vaccinated tuberculin negative children matched for sex. The highest reactivity appeared in another group of children vaccinated in infancy and tuberculin positive. Lymphocytes from BCG vaccinated children retain some sensitivity to tuberculin even years after the BCG vaccination and even at the time when the skin reactivity disappeared.

BCG Vaccine↗