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Biomedical subjects

A S Luís

Publications and source records attributed to A S Luís.

At least 19 recordsLinked to original sources
PubMed1999

[The effect of sex and menopause on basal blood levels of homocysteine and after methionine loading].

INTRODUCTION AND OBJECTIVES: We have already proved that basal and after load homocysteinemia are risk factors for vascular disease and it is also known that premenopausal women are relatively protected against this disease. The objective of this paper was the assess whether there are any differences in the plasma levels of homocystein which might contribute to explain the differences in the incidence of vascular diseases found in both sexes. PATIENTS AND METHODS: Two hundred and four patients (153 males) without previous vascular disease were enrolled in the study. These patients were participating in a screening program for cardiovascular risk factors in a central hospital in Lisbon. We evaluated the basal homocysteinemia and homocysteinemia 6 hours after an oral load with methionine (0.1 g/kg body weight). Basal and after load homocysteinemia in men and women, as well as in women before and after menopause, was compared. Because homocysteinemia does not have a normal distribution, we used non-parametric statistical tests, namely the Mann-Whitney test. RESULTS: Men had higher values for basal homocysteinemia than women (mean and standard deviation)--9.64 +/- 3.15 versus 8.56 +/- 2.82 mumol/l, (p = 0.0018)--as well as for after load homocysteinemia--24.40 +/- 7.84 versus 23.71 +/- 10.16 mumol/L, non significant difference. Premenopausal women (n = 42) had lower basal homocysteinemia values than post menopausal women (n = 9)--8.41 +/- 3.02 versus 9.23 +/- 1.38 mumol/L, p < 0.05--and similarly after load homocysteinemia values--23.86 +/- 10.65 versus 23.01 +/- 7.47 mumol/L. CONCLUSIONS: Basal homocysteinemia is significantly higher in men than in women. After menopause, basal homocysteinemia levels increase significantly in women, approaching those in men. The levels of after load homocystein are not dependent on sex or pre- or postmenopausal condition. Homocysteinemia might explain, at least partly, the differences in the incidence of vascular disease in both sexes and the increased vascular risk in postmenopausal women.

Administration, Oral↗
PubMed1999

[Homocysteinemia and vascular disease--a new risk factor is born].

In recent years there has been growing evidence that high levels of plasmatic homocysteine constitute an independent risk factor for early cardiovascular disease. In this article we review the main theories of atherosclerosis which take into account the proteins, namely homocysteine, homocysteine metabolism, the cause that may be responsible for high levels of homocysteinemia, the pathophysiologic mechanisms of vascular lesion induced by hyperhomocysteinemia, the clinical evidence that homocysteinemia constitutes a vascular risk factor and finally, the evidence that it is possible to control homocysteinemia with supplementation of co-factors of homocysteine metabolism, namely vitamin B6, B12 or folic acid.

Arteriosclerosis↗
PubMed1998

[Myocardial viability. Concept, physiopathology. Methods and diagnostic value].

The purpose of this study is to describe the concept and physiopathology of myocardial viability to provide rational use of diagnostic methodologies and their value. Great relevance has been given to the diagnosis of myocardial viability since it was published in 1982, because of the consequences of therapeutic decisions and prognostic evaluation on the patient's quality of life. The cost/benefit values of these methodologies must be adequate in clinical terms and carefully assessed.

Echocardiography↗
PubMed1995

[Severe poisoning by organophosphate compounds. An analysis of mortality and of the value of serum cholinesterase in monitoring the clinical course].

Ingestion of organophosphate (OP) compounds usually results in severe poisoning. We undertook a retrospective study of 52 consecutive patients admitted with severe OP poisoning to determine the value of serum cholinesterase (SChE) in monitoring clinical course. Considering survivors and non-survivors, we evaluate clinical and laboratory baseline characteristics, severity scores (APACHE II, SAPS II), atropine rate (mg/h), SChE evolution at 24, 72 and 120 h and final SChE (SChE at the day of discharge or death). Mortality in the ICU was 28.9% (n = 15). In both groups SChE showed a trend to increase. In survivors, SChE recovery was statistically significant for SChE 24h-SChE 72 h, SChE 24 h-SChE 120 h and SChE initial-SChE 120 h (p = 0.008, p = 0.00003, p = 0.0002 respectively). In this group a simultaneous decrease in atropine requirements was registered. In non-survivors, the rate of atropine remained unchanged up to 120 h. Three groups could be defined in non-survivors according to their final SChE and day of death. Non-survivors-1 (death in the first 24h; 2 patients) and non-survivors-2 (death after the first 24 h; 5 patients) had a final SChE below 10% of normal SChE activity and statistically different from survivors' final SChE. Non-survivors-3 (8 patients) had a final SChE similar to the survivors and death was due to sepsis and multiple organ failure (MOF). We conclude that SChE is useful in OP poisoning diagnosis and also in monitoring clinical course. SChE recovery above 10% of normal seems to correlate with good prognosis. Sepsis and MOF were important determinants of mortality.

Acute Disease↗
PubMed1994

[Homocysteinemia as a risk factor in early cerebrovascular disease].

PURPOSE: To determine whether hyperhomocysteinemia represents a risk factor of early thrombotic cerebrovascular disease. METHOD: In a group of patients under 55 years of age (n = 33, 19 males) which had suffered a stroke from 3 months to 1 year before the study, defined by clinical criteria and presence of cerebral infarction confirmed by tomography, without history or predisposition to embolic disease. The patients were matched with a group of normal controls of checkup program, in terms of age, and sex. Patients and controls with a history of alcoholism, clinical or laboratory signs of renal or hepatic insufficiency or with a history of recent ingestion of Group B vitamins were excluded since these conditions would influence homocysteinemia levels. We measured the plasmatic basal homocysteinemia of patients and controls (HC) and 6 hours later a methionine overload of 0.1 g/Kg body weight (LOAD HC). RESULTS: Patients; Controls; Signific.; Age 46.0 +/- 7.7; 45.9 +/- 7.8; NS; Basal HC. 10.1 +/- 3.4; 8.5 +/- 1.7; p < 0.05; Load HC 28.0 +/- 7.6; 22.7 +/- 5.5; p < 0.01. CONCLUSION: In this study hyperhomocysteinemia appears as a risk factor for thrombotic cerebrovascular disease before the age of 55;-The measurement of homocysteinemia after the methionine loading test was more discriminative than the basal measurement;-A larger number of patients and controls will be necessary to establish the relative importance of homocysteinemia among other vascular risk factors in cerebrovascular disease.

Adult↗
PubMed1994

[Heart failure and the clinician at the end of the 20th century].

Congestive heart failure represents a clinical syndrome whose symptoms and signs result from different etiopathogenic and pathophysiological mechanisms. Diagnosing congestive heart failure remains mainly a matter for accurate clinical methodology. Therapeutical approaches to congestive heart failure require a profound knowledge of the behaviour of each system and mechanism involved in the process, namely neurohumoral activation, dysautonomia and endothelial responses, besides renal, skeletal muscle, cardiac and pulmonary participation. So, the treatment of congestive heart failure is always multifactorial. Preventing heart failure requires also an accurate knowledge of those mechanisms, in order to apply the most appropriate measures to stop vascular and cardiac remodeling.

Autonomic Nervous System Diseases↗
PubMed1994

[Homocysteinemia as a risk factor for early myocardial infarct--a case-control study].

PURPOSE: To investigate if hyper-homocysteinemia represents an independent risk factor of early coronary disease. METHODS: We studied a group of patients under 45 years old, that suffered a myocardial infarction from 3 months and 1 year before the study. The patients were matched with a group of normal controls of a check-up program, in terms of age, sex, smoking habits, presence of hypertension, obesity, (Quetelet Index), presence of diabetes, basal glycemia, total cholesterol, LDL and HDL cholesterol. Later we measured to patients (Pts) and controls (Cts) the plasmatic basal homocysteinemia (B HC) and 6 hours after a methionine overload of 0.1 g/kg body weight (L HC). RESULTS: [table: see text] CONCLUSIONS: In this study hyper-homocysteinemia appears as an independent risk factor of early coronary disease. The measurement of homocysteinemia after the methionine loading test was more discriminative than the basal measurement.

Adult↗
PubMed1994

[The evaluation of the hemodynamic effects of captopril one year after a myocardial infarct].

In the present study, the authors evaluate the haemodynamic effects of continuous captopril therapy during one-year after a first anterior myocardial infarction (MI). Haemodynamic measurements are made during the first 48 hours after de MI and repeated one year later. Patients are divided in two groups: The first group had therapy with acetylsalicylic acid (ASA) and isosorbide dinitrate (ISDNI) and the second group had therapy with ASA, ISDNI and captopril. From their results the authors conclude that captopril helps peripheral resistances elevations, and that this is one of the mechanisms by which it can have a favourable effect after an anterior MI.

Adult↗
PubMed1993

[Unstable angina. An evaluation of a diagnostic and therapeutic methodology].

The authors describe the diagnostic and therapeutic management of 55 patients with the diagnosis of unstable angina admitted at a medical intensive care unit. According to Braunwald classification, 52 patients had primary angina and the remaining three had post-infarction angina. Risk stratification was based on non invasive procedures such as 2D echocardiogram and exercise test after clinical stabilization. Coronary angiography was performed in all patients. Most of the patients needed revascularization: 62% by percutaneous transluminal coronary angioplasty (PTCA) and 13% were submitted to coronary artery by-pass graft (CABG). None of the patients died during hospitalization.

Adult↗
PubMed1993

[Risk stratification in non-Q-wave myocardial infarct].

There was been some controversy about non-Q wave myocardial infarction, its evolution and prognosis. The most recent studies showed that, in spite of the low immediate mortality in non-Q wave myocardial infarction, the long-term risk of ischaemia, reinfarction or sudden death is equal or even greater than in the Q-Wave myocardial infarction. In order to define an adequate ischaemic risk stratification strategy in the post non-Q wave myocardial infarction without complications, the authors studied 21 patients who were submitted to treadmill exercise test and coronary angiography within 30 days after the acute event. Of the 17 patients with positive stress testing, 14 showed significant relationship between ischaemic area detected in the stress testing and the anatomic localization and severity of the lesions in the coronary angiography (chi 2 = 14,875; p < 0.006). Revascularization therapy (PTCA or bypass surgery) was very high in this group of patients (47.6%). From the date obtained the authors conclude that it is not necessary to use invasive studies in every patient that has suffered from non-Q wave myocardial infarction without complications, since the stress testing showed high sensitivity (94.4%), specificity (75%) and high predictive value (100%) in the ischaemic risk stratification.

Chi-Square Distribution↗
PubMed1993

["Severe" congestive heart failure at a medical center].

UNLABELLED: Heart failure (HF) is a dynamic clinical syndrome depending on multiple hemodynamic and neurohormonal factors. This syndrome concerns not only left ventricular systolic dysfunction but also left ventricular diastolic dysfunction and right ventricular dysfunction. Clinical features and therapeutic approaches are different for each of them. NYHA class IV is just one of the various prognostic factors of heart failure; consequently, severe heart failure is not synonymous of NYHA class IV. OBJECTIVE: To study hospitalised patients with heart failure in NYHA class IV, in order to characterise the predominant dysfunction, and analyze evolution and mortality. DESIGN: A retrospective analysis of a prospective study. SETTING: Hundred and eight hospitalised patients (1985-89). Patients with chronic obstructive pulmonary disease and acute myocardial infarction were excluded. PATIENTS: Sixty nine patients: 29 female and 40 male, aged 18 to 81 years old (m = 59 +/- 15.5). METHODS: Patients were clinically examined and had chest radiographs, electrocardiogram and M + 2D mode echocardiogram. Three groups were identified: Group I-patients with predominant left ventricular systolic dysfunction; Group II-patients with predominant left ventricular diastolic dysfunction; Group III-patients with predominant right ventricular dysfunction. RESULTS: 41% of the patients had coronary artery disease; 44%, valvular heart disease; 11.8% dilated cardiomyopathy; 8.7% hypertrophic cardiomyopathy; 8.7% hypertensive cardiomyopathy. Fifty five percent of the patients were in group I and the major aetiology were coronary artery disease and valvular heart disease; 25% of the patients were in group II and the major aetiology were coronary artery disease and hypertrophic cardiomyopathy; 20% of the patients were in group III, all had valvular heart disease. The global mortality during the hospitalisation period was 15.9%, mostly group III (29%) and II (17%). CONCLUSIONS: Heart failure patients in NYHA class IV formed an heterogeneous group, requiring individualised therapeutic approaches. Left ventricular systolic dysfunction was the major pathophysiological mechanism, however, diastolic dysfunction and right ventricular dysfunction were frequent. Coronary artery disease presented as a frequent aetiology of heart failure, resulting in diastolic and/or systolic dysfunction. Valvular heart disease can be present as left ventricular systolic or diastolic dysfunction or as a right ventricular dysfunction, depending on the valvulopathy and the time of evolution. Echocardiography, in association with clinical features, has been very useful for each patient approach, allowing HF aetiology and pathophysiological mechanisms characterisation. The low mortality observed in this study was related certainly to the correction of precipitating factors, together with early etiologic diagnosis and pathophysiological characterisation, and adequate individualised treatment.

Adolescent↗