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Biomedical subjects

M de Oliveira

Publications and source records attributed to M de Oliveira.

At least 19 recordsLinked to original sources

Rapid identification of Mycobacteria to the species level using INNO-LiPA Mycobacteria, a reverse hybridization assay.

INNO-LiPA Mycobacteria (LiPA; Innogenetics, Zwijnaarde, Belgium) is a kit for the simultaneous detection and identification of Mycobacterium species in culture and identifies the Mycobacterium tuberculosis complex, the M. avium complex (MAC), and the following Mycobacterium species: M. kansasii, M. avium, M. intracellulare, M. scrofulaceum, M. gordonae, M. xenopi, and the M. chelonae-M. abscessus complex. The assay, which targets the 16S-23S rRNA spacer region, was evaluated on 157 mycobacterial strains that had been identified by conventional techniques and PCR-restriction enzyme analysis of the hsp65 gene (PRA). Forty-seven reference strains consisting of 37 different species and 110 human clinical isolates were submitted to the test, and all were hybridized with the Mycobacterium genus probe (MYC) on the LiPA strip (100% sensitivity). Ninety-four isolates hybridized to their corresponding species- or complex-specific probes; only one isolate phenotypically identified as M. gordonae did not react with its specific probe (99.4% accuracy). Thirty-seven MAC strains were phenotypically identified to the complex level and to the species level by LiPA as M. avium (n = 18) or M. intracellulare (n = 7) or as belonging to the M. avium-M. intracellulare-M. scrofulaceum complex (n = 12). Of the last 12 strains, 10 had M. avium PRA patterns and 2 had M. intracellulare PRA patterns. Three isolates that had been identified as a single species by conventional identification were proven to be mixed cultures by the LiPA assay. The whole procedure can be performed in 1 working day, starting with the supernatant of a small amount of bacterial mass that had been treated by freezing and then boiling.

Bacterial Proteins↗

[Non-infectious thrombotic endocarditis: a case report].

A 48 year-old female patient, admitted with an ischemic stroke, had a transesophageal echocardiogram (TEE) that revealed a dense vegetation in the noncoronary aortic cusp, which was considered the probable source of embolism. The clinical investigation did not identify any other disease or infectious process. However the lack of histologic proof, the absence of fever, the fact that the blood cultures were persistently negative, the patient recovery with no need of antibiotics, and the results of the TEE, are highly suggestive of the presence of a non infectious thrombotic endocarditis. After 18 months of anti-platelet treatment, the patient showed no new embolic episodes and TEE demonstrated the resolution of the vegetation.

Echocardiography, Transesophageal↗

Long-term morbidity in patients suffering a sternal fracture following discharge from the A and E department.

OBJECTIVE: To describe the duration of symptoms and long term outcome in patients who were discharged home from the A and E department having sustained an isolated fracture of the sternum. DESIGN: Postal questionnaire. OUTCOME MEASURES: Patients were asked specific questions regarding advice and analgesia given on discharge, length of time off work, if appropriate, and length of time of symptoms related to the injury. RESULTS: A response rate of 55% was achieved. The majority of patients had been involved in a motor vehicle accident. Chest pain was the predominant persisting symptom lasting for a mean period of 10.9 weeks. Duration of symptoms was significantly prolonged in patients over the age of 50 (p < 0.03). Although injury was more common in females this was not statistically significant (p < 0.09). Advice given regarding rehabilitation was poor and variable. CONCLUSION: Patients suffering a sternal fracture have prolonged symptoms. Those being discharged home from the A and E department are at present being given variable and poor advice. A more formal approach to rehabilitation, analgesia and a letter to the general practitioner outlining prognosis will improve their standard of care.

Accidents, Traffic↗

Increased non-angiotensin II [125I]CGP 42112 binding in rat carotid artery after balloon injury.

In this study, [125I]CGP 42112, a ligand of high affinity and selectivity for the angiotensin II AT2 receptor, was used to detect and quantify a non-angiotensin II binding site in the balloon-injured carotid artery of the rat. The amount of [125I]CGP 42112 binding was significantly enhanced in the adventitia of the injured arteries. Localization of the binding site using emulsion autoradiography and immunocytochemistry suggests that the binding sites may be expressed by macrophages in the inflamed tissue surrounding the injured artery.

Angiotensin II↗

[Restenosis: physiopathology, treatments and prevention].

Despite fifteen years of extensive research, we still do not know how to predict or prevent restenosis. Angioplasty induces lesions in the intima, media and sometimes adventitia, resulting in a cicatricial process comprising proliferation and migration of smooth muscle cells towards the intima and secretion of extracellular matrix, leading to the formation of a neointima. Since angioplasty is associated with the simultaneous development of neointimal hyperplasia and restenosis, a cause and a effect relationship has therefore been proposed between neointimal hyperplasia and restenosis. All the restenosis prevention strategies based on inhibition of smooth muscle cell proliferation, which successfully limited restenosis in animal models have failed in man, due to the hazardous extrapolations from experimental models which are very different from the atheromatous lesions observed in man, rather than to the use of animal models in general. It is reasonable to wonder whether we have not selected the wrong target: is smooth muscle cell proliferation really responsible for restenosis? Experimental results supported by histological and ultrasonographic data in man, show that the cicatricial process which induces restenosis consists of constrictive remodelling, which decreases the perimeter of the external elastic lamina and the lumen. The use of stents appears to be the primary strategy designed to limit restenosis and prevent constrictive remodelling in man, even if it stimulates neointimal hyperplasia. Progress in the understanding of the mechanisms of postangioplasty remodelling open new perspectives in the prevention of restenosis.

Angioplasty, Balloon, Coronary↗

Effects of diltiazem on myocardial ischemia in patients with coronary artery disease.

OBJECTIVES: To evaluate the effect of diltiazem on the characteristics of ischemic episodes detected by Holter monitoring in a group of patients with proven coronary artery disease. SETTING: Department of Cardiology, Santa Marta Hospital, Lisbon. METHODS: Eleven selected out-patients, aged 48 to 79 years, with transient ST-segmental depression on Holter monitoring and proven coronary artery disease, were submitted to a double-blind crossover placebo controlled study, during hospitalization. The total ischemic burden of each patient and an analysis of ischemic episodes were evaluated before and during the drug/placebo phase trial. Three groups of ischemic episodes were considered: group I constituted by 66 episodes found on basal Holter recording; group II by 28 episodes detected during placebo trial and group III by 12 episodes detected during diltiazem trial. RESULTS: A reduction of the number of ischemic episodes was predominantly observed with the diltiazem administration. Statistically significant differences were observed between basal and placebo groups and especially between basal and diltiazem groups concerning the mean maximum ST-segment depression (2.17 vs 1.80; p = 0.030 and 2.17 vs 1.54; p = 0.0091). Significant differences were also obtained between the above mentioned groups concerning the heart rate variation from the onset of ST-segment depression to its maximum depression (13.5 vs 9.69; p = 0.023 and 13.5 vs 2.91; p = 0.01) and from two minutes before the onset of ST-segment depression to its maximum depression (21.2 vs 12.67; p = 0.012 and 21.2 vs 8.75 p = 0.016). CONCLUSIONS: Diltiazem seems to reduce the number of ischemic episodes in patients with coronary artery disease, during hospitalization. The study of its effects on the characteristics of ischemia requires further investigation with a greater number of patients. The limitations of the present study, described in the discussion, must be taken into account in future pharmacological investigations with Holter monitoring.

Aged↗

Baroreceptor reflex control of heart rate during development of coarctation hypertension.

To study whether resetting of the baroreceptors is accompanied by normal reflex activity to the heart, we analyzed time-course changes of pressure, heart rate, baroreceptor reflex sensitivity, and plasma renin activity during the development of coarctation hypertension. Baseline heart rate was measured daily, and plasma renin activity and reflex changes in heart rate (bolus injections of either phenylephrine or nitroprusside, 0.2-25.6 micrograms/kg i.v.) were recorded at different times in coarcted and sham-coarcted rats. Hypertension was stable (approximately 39% from baseline mean arterial pressure of 112 +/- 3 mm Hg), whereas heart rate (333 +/- 4 beats per minute) showed a biphasic behavior: bradycardia at 6 hours (264 +/- 7 beats per minute) and tachycardia at 5 days (418 +/- 14 beats per minute). On day 10 of hypertension, heart rate was normal. Plasma renin activity was markedly increased only after 6 hours (4.9 times). Reflex bradycardia exhibited a progressive impairment: The slopes of the regression lines between changes in heart rate and changes in mean arterial pressure were not significantly reduced at 6 and 48 hours when the resetting was in development (changes of 17% and 28% from a control of -1.89 +/- 0.20 beats per minute/mm Hg) but were significantly depressed after the resetting had been completed (-51% and -56% at 5 and 10 days, respectively). Reflex tachycardia was significantly reduced in all periods studied (75%, 78%, 52%, and 61% at 6 hours and 2, 5, and 10 days, respectively; -3.92 +/- 0.42 beats per minute/mm Hg in sham rats).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Functional significance of premature ventricular complex morphology evaluated during treadmill exercise stress test in patients with coronary artery disease.

OBJECTIVES: To evaluate the relation between premature ventricular complexes morphology and left ventricular myocardial systolic function in patients with proved coronary artery disease. SETTING: Department of Cardiology at General Hospital. METHODS: From 112 patients (pts) with proved coronary artery disease, thirty-three pts with premature ventricular complexes (PVC) detected during treadmill exercise stress test were selected. Two groups of pts were considered: group I-20 pts with regular contour or with a narrow notching (< 40 ms; type I PVC) and group II-13 patients with wide notching (> 40 ms; type II PVC). In each group the following parameters were studied: ejection fraction, QRS duration, duration of exercise, number of metabolic units and the prevalence of ventricular aneurysm and mitral regurgitation. RESULTS: Statistical significant differences were found between group I and II concerning the mean ejection fraction (59.2% vs 48.6%; p < 0.05). The prevalence of ventricular aneurysm and mitral regurgitation was higher in patients with type II ventricular premature complexes (10% vs 30%). CONCLUSION: Particular characteristics of premature ventricular complexes detected during treadmill exercise stress test, in patients with proved coronary artery disease, suggest the presence of left ventricular myocardial systolic dysfunction.

Coronary Disease↗

[Value of two-dimensional echocardiography in the prognosis of patients after acute myocardial infarction].

OBJECTIVES: To evaluate the prognostic importance of two-dimensional echocardiography in patients (pts) with acute myocardial infarction. SETTING: Department of Cardiology in a Central Hospital. METHODS: In 71 pts (63 men and 8 women) aged 35 to 75 years interned with a proved myocardial infarction, a score of left ventricular segmental wall motion was used on echocardiographic examination performed during the late hospital phase, to evaluate left ventricular function. Two groups of pts were considered: group A constituted by 38 pts with complication detected during follow-up that ranged 4 to 18 months; group B by 33 pts with no cardiac events for the same period. The relation of the wall motion score with each group and the location of myocardial infarction was performed. RESULTS: In group A, the mean score index was 1.67 in pts with angina, 1.08 in pts with heart failure and 0.82 in pts who died. The mean score index was 1.25, 1.57 and 1.18 respectively in pts with an anterior, inferior and antero-inferior infarction. In group B, the mean score index was 1.70 in pts with an anterior infarction, 1.85 in those with an inferior infarction and 1.33 in the patient with an antero-inferior infarction. Patients with a non-Q wave infarction had a mean score index of 2. The mean score index was significantly different between group A and B (respectively 1.33 vs 1.79; p less than 0.00001) and a mean score index of 1.53 was considered the mean risk value. CONCLUSIONS: Two-dimensional echocardiography performed during hospital predischarge permits risk stratification after acute myocardial infarction, specially for death and heart failure.

Adult↗

[Hemodynamic assessment after heart transplantation].

OBJECTIVE: Comparative analysis of the results of the hemodynamic evaluations performed at the preoperative period, during the first week and at the end of the first and second years, after orthotopic heart transplantation. DESIGN: Retrospective study of hemodynamic evaluation of patients submitted to orthotopic cardiac transplantation from April 1987 to April 1990. SETTING: Transplanted patients admitted at the cardiology and cardio-toracic surgery departments of the Hospital Santa Marta. PATIENTS: 15 patients (eleven males and four females) aged 21 to 55 years (mean = 33.3 +/- 10.5), with the preoperative diagnosis: dilated cardiomyopathy in 11, ischemic heart disease in three and hypertrophic cardiomyopathy in one patient. All the patients were on triple immunosuppressive therapy (cyclosporine A, azatioprine and prednisolone) at the time of the first week evaluation. Three of the eight patients evaluated at the end of the first year were with double immunosuppressive regimen (without steroids), seven at NYHA functional class I and one patient at class II. The three patients evaluated at the end of the second year were on triple immunosuppressive regimen and in class I. INTERVENTIONS: We considered, preoperatively (PrOp), at the first week (1W), and at the end of the first (1Y) and second (2Y) years: mean right atrial pressure (RA), systolic pulmonary arterial pressure (PAs), mean pulmonary arterial pressure (PAm), pulmonary capillary wedge pressure (PCW), mean systemic arterial pressure (SAm), cardiac index (CI), pulmonary vascular resistance (PVR) and systemic vascular resistance (SVR). At 1Y and 2y there were also considered the left ventricular end-diastolic pressure (LVEDP) and the ejection fraction (Ej). RESULTS: (table; see text) The results found at 2Y were similar to those showed at 1Y. At 1Y and 2Y LVEDP and Ej were normal. CONCLUSIONS: A high prevalence of mild to moderate hemodynamic disturbances characterizes the early post-operative period in cardiac transplantation. Abnormal pressures on right atrium, pulmonary artery, pulmonary capillary wedge pressure, are found on a significant number of patients, and pulmonary and systemic vascular resistances are also elevated. However at the end of the first year there is a significant improvement compared with the first week. Normality is the hallmark of hemodynamic evaluation performed in transplant recipients at the end of the first and second years.

Heart Transplantation↗

Incidence, characteristics and coronariographic significance of myocardial ischemia during daily life in patients with angina pectoris.

OBJECTIVES: To evaluate the incidence, characteristics and angiographic significance of myocardial ischemia detected on Holter monitoring in a group of patients with stable angina pectoris. SETTING: Department of Cardiology of a Central Terciary Hospital. METHODS: In 24 patients (pts) with stable angina pectoris and proven coronary artery disease (11 pts with left main or three vessel disease; 13 pts with one or two vessel disease), a 24 hour Holter monitoring was performed. Two groups of ischemic episodes were considered: Group I with 65 ischemic episodes detected in pts with left main or three vessel disease and group II constituted by 17 ischemic episodes detected in pts with one or two vessel disease. RESULTS: The incidence of myocardial ischemia was 91% in pts with left main or three vessel disease and 46% in pts with one or two vessel disease. Statistically significant differences were seen between group I and II concerning the mean heart rate variation from two minutes before onset of ST-segment depression to its onset (3.5 bpm vs 7.4 bpm; p less than 0.05) and from the onset of ST-segment depression to its maximal depression (6.5 bpm vs 15 bpm; p less than 0.000001). CONCLUSIONS: The presence of myocardial ischemia and some of its characteristics on Holter monitoring seem to have a relation with the severity of coronary artery disease in patients with stable angina pectoris.

Activities of Daily Living↗

[Clinical and hemodynamic efficacy of enalapril in severe congestive heart failure].

OBJECTIVES: Evaluate the clinical and hemodynamic efficacy of enalapril in the treatment of severe congestive heart failure, refractory to the classic therapeutics with diuretics and digitalis. SETTING: Hospitalized patients (pts) of a cardiac department. MATERIAL AND METHODS: 10 pts with a mean age of 57.8 years in whom a Swan-Ganz catheter was placed for 72 hours to monitor the right pressures and cardiac output, with regular control of arterial blood pressure and cardiac frequency. Low doses of enalapril (2.5 mg) were utilized at the start of the treatment and this dose was readjusted depending on the clinic and hemodynamic parameters. RESULTS: the 10 pts had the following characteristics: Basal-mean pulmonary arterial pressure (PAP) 34.1 mmHg, Pulmonary wedge pressure (PWP) 21.1 mmHg, cardiac output (CO) 4.8 l/min, cardiac index (CI) 2.8 l/min/m2. After 72 hours with enalapril treatment, these measurements were: PAP-23.8 mmHg, PWP-12.6 mmHg, CO-5.2 l/min and Cl-3.0 ll/min/m2. These differences were statistically significant. With a follow-up of 18.4 months, there was also a clinical improvement; of the 4 pts in class III, 2 moved to class II and 2 to class I; the 4 pts in class IV 4 moved to class II; two pts had died. CONCLUSIONS: In severe heart failure, the addition of enalapril to the classic therapy has allowed the immediate improvement of the clinical and hemodynamic indexes and this improvement was maintained in the follow-up period.

Aged↗

[Influence of recipient auricular contraction on the left ventricle filling pattern of the transplanted heart studied with pulsed Doppler echocardiography].

OBJECTIVES: to evaluate the influence of recipient atrial contraction (RAC) timing on left ventricular filling pattern (LVFP), assessed by Pulsed Doppler, in orthotopic transplant recipients (OTR). STUDY DESIGN: prospective study of OTR. SETTING: patients (pts) submitted to orthotopic heart transplantation at Hospital de Santa Marta, from April/87 to March/89, in routine evaluation. PARTICIPANTS: nine pts, aged 21 to 55 years (mean = 32 +/- 11), 0.5 to 20 (mean = 7.4 +/- 6.9) months post-operatively. METHODS: in each pt 40 to 60 (mean 52) consecutive cardiac cycles were analysed; five groups (Gr.) were considered, according to RAC (P wave) position in the cardiac cycle: Gr. I--Early systole, GR. II--late systole, Gr. III--early diastole, Gr. IV--late diastole and Gr. V--absent. The following parameters were studied: peak early diastolic mitral flow velocity (Evel), peak late diastolic mitral flow velocity (Avel), ratio Evel/Avel, (E/A) and pressure half time (PHT). RESULTS: 1) Evel and E/A were significantly higher, Avel lower, and PHT shorter, in Gr II and III; 2) Avel was higher and E/A smaller in Gr. IV; 3) no statistically significant differences were found betwenn Gr. I and V, for any of the parameters analised. CONCLUSIONS: the timing of RAC significantly influences LVFP and it must be considered on Echo-Doppler analysis of diastolic function in OTR.

Adult↗

[Biopsy of the right ventricle endomyocardium. Experience at the Santa Marta Hospital].

OBJECTIVE: To review the experience of Santa Marta Hospital in the right ventricle endomyocardial biopsy technique. DESIGN: Retrospective analysis of the results, diagnostic value and complications of the myocardial biopsies performed between April/87 and March/90. PATIENTS AND INTERVENTIONS: 255 biopsies were performed; 221 on 13 patients submitted to orthotopic heart transplantation (nine male and four female, aged between 21 and 55 years old), and the remaining on 34 patients (22 male and 12 female aged between 15 and 64 years old), mainly on cardiomyopathies. RESULTS: In 221 biopsies performed in heart transplant recipients, we found: 109 with no rejection, 21 with moderate rejection, 57 with mild rejection and only one case showed severe rejection. In this group six biopsies were considered inconclusive. In the group of patients not submitted to heart transplantation the histological findings were inespecific in the great majority of the cases. In the 255 procedures four complications were detected (1.56%), with no mortality; two hemopericardium with tamponade (0.78%), one pneumothorax and one atrial fibrillation. CONCLUSIONS: Endomyocardial biopsy essential for histological diagnosis of acute rejection following heart transplantation has revealed to be a save procedure with a small number of complications.

Adolescent↗

Impaired baroreflex control of heart rate in high-renin renal hypertension.

The reflex responses of heart rate (HR) to bolus injection and infusion of phenylephrine and nitroglycerine were studied in rats with one-kidney, one clip (1-K, 1C) hypertension and hypertension produced by aortic ligation. Rats with mild 1-K, 1C hypertension (147 +/- 4 mmHg) and a normal renin-angiotensin system (RAS) activity had normal bradycardic and tachycardic responses, whereas rats with severe hypertension (208 +/- 3 mmHg) and over-active RAS showed impairment (70-80%) of the responses. After 12 days of aortic ligation rats with mild (146 +/- 2 mmHg) and severe (175 +/- 3 mmHg) hypertension exhibited overactivity of the RAS and marked impairment of the baroreflex control of HR. Normalization of RAS activity in rats with mild hypertension 60 days after aortic ligation, coincided with normalization of the bradycardic responses, whereas the abnormality persisted in those rats with severe hypertension in which hyperactivity of RAS also persisted. The response to 20-s carotid occlusion and the HR responses to electrical stimulation of the vagus nerve were normal in rats with renal hypertension, 12 days after aortic ligation. An ether inhalation test produced a marked reduction of 60% in the HR of control awake rats accompanied by a 46 +/- 5 mmHg increase in blood pressure. Reflex pathways other than those through the baroreceptors were largely responsible for the bradycardia since responses remained unchanged in rats with sino-aortic denervation (SAD) or when the pressure increase was prevented by phenoxybenzamine administration.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

The electrostatic molecular potential of tRNAPhe. IV. The potentials and steric accessibilities of sites associated with the bases.

The sites of the 76 nucleic acid bases of tRNAPhe potentially reactive towards electrophiles are studied by calculations on the associated molecular electrostatic potentials and the static steric accessibilities. Each of these sites is treated in its environment within the macromolecule. The influence of various schemes of screening by countercations of the backbone phosphates on the electrostatic potentials is investigated. The possible significance of the potentials and accessibilities in connection with observed chemical reactivities is discussed.

Adenine↗