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Biomedical subjects

R Ferreira

Publications and source records attributed to R Ferreira.

At least 19 recordsLinked to original sources
PubMed1996

Influence of coronary lesions morphology on treadmill exercise stress testing after acute myocardial infarction.

OBJECTIVES: To evaluate the influence of infarct related artery lesion morphology on the exercise stress test performed after a first myocardial infarction. METHODS: We reviewed coronary angiography and the exercise stress test performed before discharge from hospital in 105 consecutive patients (91.4% male, mean age 49.6 +/- 9.2 years) with first acute myocardial infarction. Complex coronary lesions were defined by the presence of one of the following characteristics: ulcers, thrombus, shoulders, irregularities and eccentricity. According to either the existence or absence of complex coronary lesions, two groups were considered: Group I--42 patients with complex coronary lesions, and Group II--47 patients without these characteristics in coronary angiogram. Sixteen pts (14%) were excluded because the infarct related artery was occluded or existence of complex lesions in other coronary artery not related to the infarct. Left ventricular systolic function was analyzed using the "CASS score". Exercise stress test performed between the 10th and the 15th day after myocardial infarction, using Bruce protocol, were reviewed. The following parameters were analyzed: exercise time, number of metabolic equivalent units (METS), maximal heart rate attained, double product variation and number of patients with significant ST segment depression and/or angina. RESULTS: No statistically significant differences between the two groups were obtained as far as age, sex, left ventricular function, number of diseased vessels and lesions severity. From the analysis of ergometric parameters we did not find any difference between the two groups of patients about exercise time (Group A--8.37 +/- 2.6 versus (vs) Group B 8.38 +/- 3.18), METS (Group A--8.22 +/- 2.87 vs Group B--8.13 +/- 2.97), maximal heart rate (Group A--88.2% vs Group B--87.5%) and double product variation (Group A--14547 +/- 5492 vs Group B--14553 +/- 5387). However, the number of ischemic response (defined by usual criteria of St-segment depression and/or angina) was significantly greater in patients with complex coronary lesions (ST--segment depression: Group A--26 pts vs Group B--19 pts, p < 0.05/Angina: Group A--16 pts vs Group B--4 pts, p < 0.001). Thus, complex coronary lesions are related to a high incidence of residual ischemic phenomena detected by electrocardiographic exercise stress test performed on predischarge period of acute myocardial infarction. Further studies will be necessary to show the prognostic value of particular angiographic characteristics found in coronary plaques.

Adult↗
PubMed1995

A polyomavirus enhancer mutant confers ubiquitous high transcriptional efficiency to the SV40 late promoter.

To identify expression plasmids with high efficiency of transcription and with a broad tissue and cell range, we have constructed a recombinant vector combining the late SV40 promoter and the polyomavirus regulatory region derived from a mutant (PyNB11/1) which displays a very wide host range. We show that these recombinant enhancer-promoters are efficient drivers for heterologous gene transcription and expression in vitro in all mouse and human cells tested. The most active combination we identified contained the mutant enhancer (PyNB11/1) in the late orientation. This construct was able to promote a high efficiency of expression without significant fluctuation between cells of different tissutal origin or different differentiative stage. A possible interpretation of these results is discussed.

3T3 Cells↗
PubMed1995

Recurrent and novel LDL receptor gene mutations causing heterozygous familial hypercholesterolemia in La Habana.

The molecular basis of familial hypercholesterolemia (FH) in three families of Spanish descent from La Habana was investigated by the candidate gene approach. The Arg3500Gln mutation of apolipoprotein B-100 was not found. Identification of low density lipoprotein receptor (LDLR) gene haplotypes segregating with FH guided the characterisation of three point mutations by automated sequencing. One, a Val408-->Met missense mutation, a founder mutation in Afrikaner FH patients, was recurrent, being associated with a distinct DNA haplotype. The other two, Glu256-->Lys and Val776-->Met missense mutations, were novel and modified highly conserved residues. These mutations were absent in normolipidemic subjects and were associated in heterozygous carriers with twice the cholesterol levels observed in non-carriers. Noticeably, cardiovascular complications were rarely observed in older heterozygotes, even in those with the Afrikaner FH-2 mutation. These findings confirm the molecular heterogeneity of LDLR gene mutations causing FH and the variability of their expression across different populations.

Adolescent↗
PubMed1995

[Experience of the exclusive use of arteries in myocardial revascularization].

OBJECTIVES: To present the initial experience of a surgical team from Santa Marta Hospital using exclusive arterial grafts on coronary bypass surgery. SETTING: Cardiology and Cardiothoracic Departments. POPULATION AND METHODS: From November 1987 to May 1994, 176 consecutive patients were submitted to surgical myocardial revascularization with the exclusive use of arterial grafts. The patients were operated by one cardiothoracic surgical team. A revision of clinical and angiographic characteristics of the patients was done along with the surgical procedure and intrahospital morbidity. After hospital discharge, follow-up was done by direct evaluation and/or by a questionnaire made using phone or letter on a periodical basis. RESULTS: The medium number of coronary bypasses performed were 2.07 +/- 0.8. The left internal mammary artery was the vessel more frequently used, specially to the myocardial area supplied by the left coronary descending artery. The right internal mammary artery was the second arterial graft more currently used. Gastroepiploic artery was utilized preferentially to coronary arteries supplying the inferior wall of the heart. Hospital mortality was 3.4%-6 patients. One hundred twenty patients have a normal life, without physical restrictions, 25% of the patients have symptoms of angina that is severe in 9. Mean follow-up time was 34 +/- 10 months. IN CONCLUSION: Coronary artery bypass surgery with exclusive use of arterial grafts can be executed with an acceptable mortality and low morbidity rates, even in urgent cases, with relieve of cardiac symptoms and good quality of life.

Adult↗
PubMed1995

Wall motion abnormalities and late ventricular arrhythmia during the predischarge phase of acute myocardial infarction.

BACKGROUND: Left ventricular wall aneurysm is a complication of acute myocardial infarction which has been considered a precipitating factor of cardiac failure and ventricular arrhythmia. We have evaluated the relation between severe left ventricular wall motion abnormalities and ventricular arrhythmia. METHODS: During a two-year period 146 patients admitted to a coronary care unit with acute myocardial infarction were studied. Radionuclide angiography performed within the second and the fourth weeks was used to analyse phase and wall motility changes, and patients were divided into three groups: 1) Hypokinesia and/or akinesia localized to one segment: with no or slight changes in phase image--102 patients; 2) Aneurysm: left ventricular deformity with well-defined chromatic changes in phase image--19 patients; and 3) Dyskinesia and/or extensive akinesia of two or more segments: phase image with diffuse heterogeneous changes--25 patients. Ventricular arrhythmia was studied using Holter electrocardiography taken during the second week of acute myocardial infarction. Three rhythmic profiles were considered: no premature ventricular contractions--41 patients; with three or more than three premature ventricular contractions per hour--38 patients; repetitive premature ventricular contractions--20 patients. RESULTS: Premature ventricular contractions were absent in 31 (30%) of the patients with hypokinesia/localized akinesia vs 8 (42%) of the patients with aneurysm, and vs 2 (8%) of the patients with dyskinesia/extensive akinesia. Premature ventricular contractions were frequent (> or = 3/h) in 22 (22%) of the patients with hypokinesia/localized akinesia vs 4 (21%) of the patients with aneurysm (p = 0.35; NS), and vs 12 (48%) of the patients with dyskinesia/extensive akinesia (p=0.003). Repetitive premature ventricular contractions were present in 10 (10%) of the patients with hypokinesia/localized akinesia vs 2 (11%) of the patients with aneurysm, and vs 8 (32%) of the patients with dyskinesia/extensive akinesia (p=0.008). CONCLUSIONS: We conclude that the presence of aneurysm was not associated with a higher occurrence of ventricular arrhythmia, but patients with dyskinesia/extensive akinesia had a higher occurrence of ventricular arrhythmia, > or = 3 premature ventricular contractions per hour and repetitive premature ventricular contractions. Our results suggest that ventricular arrhythmia is related to functionally severe wall motion abnormalities, and not to anatomical discriminants. This finding leads us to suggest different electrophysiological mechanisms behind these two entities.

Adult↗
PubMed1995

[Acute aortic dissection. Therapeutic strategies and results].

OBJECTIVE: To analyse early and medium-term results of patients (pts) with acute aortic dissection (DAO) regarding the importance of the different therapeutic modalities adopted. DESIGN: Retrospective study of the cases with DAO admitted in the cardiology intensive care unit of Santa Marta Hospital. POPULATION: 46 pts (aged 25 to 80 years) with the diagnosis of DAO from January/1989 throughout December/1993. RESULTS: early mortality rate (30 days) was 36%. DAO type A Two cases were treated only with medical therapy for they suffer from severe associated pathology. Twenty eight pts were treated surgically. In this group mortality concerning time passed from the beginning of the symptoms throughout the surgery was: < 24 h-31%, 24-72 h-40%, > 72 h-63%. Among 17 discharged pts mortality occurred in 7% during the first year. DAO type B In pts with uncomplicated Stanford type B DAO survival was 90%. Emergency surgery was performed in pts who developed complications such as rupture of the aorta, occlusion of major arteries or extension of dissection. In this particular group mortality was 66%. Among 11 discharged pts with type B DAO 9% died within one year. During the follow-up period of 17.4 +/- 14.8 months one third of the pts discharged from hospital had clinical events. CONCLUSION: despite new advances in diagnostic and therapeutic approaches, DAO still's reported as a relatively high hospital mortality situation. Remove pts to an institution with ability to perform quickly the correct diagnosis and treatment becomes essential. Clinical presentation, type of DAO, surgery timing when indicated and major complications were of particular importance in the prognosis of pts with DAO. The frequency of cardiovascular events in pts who left the hospital alive emphasized the need to maintain blood pressure within normal limits.

Acute Disease↗
PubMed1995

[Acute myocardial infarct: apropos a clinical case].

The AA describe a clinical case of acute myocardial infarction (A.M.I.) with prodromal angina and an initial diagnosis based exclusively on clinical criteria; the patient was submitted to thrombolysis and had recurrent angina which led to the performance of rescue percutaneous coronary angioplasty (P.T.C.A.) that was successful. The clinical situations that may precede A.M.I. are discussed and the importance of the clinical presentation in its diagnosis are stressed. The indications and benefits of rescue P.T.C.A. are also discussed and the AA. conclude that the patients with prodromata of A.M.I. must be kept under clinical observation, so that prompt necessary therapeutic measures may be undertaken and that rescue P.T.C.A. is a therapeutic option of proven clinical benefit.

Diagnosis, Differential↗
PubMed1995

On the statistical distribution of amino acid residue in randomly synthesized peptides.

The probability of randomly synthesized peptides having an excess of a given residue Ri (nRi > N/2; N = size of the peptide) decreases strongly with peptide size. For a strong specific interaction of a Ri, rich peptide with a given sequence of a ribotide chain, peptides should be reasonably large. We discuss how a compromise can be achieved that may have had an important role on the origin of the genetic code.

Amino Acids↗
PubMed1994

Results from a reference laboratory for prenatal diagnosis of sickle cell disorders in Cuba.

A nationwide programme for the prevention of sickle cell (SS and SC) disorders was initiated in Cuba in 1983. Couples at risk were identified by screening pregnant women and the partners of those who carry an abnormal haemoglobin, followed by genetic counselling and the offer of prenatal diagnosis. Prenatal diagnosis was performed in one laboratory, which had carried out 1068 prenatal tests for Hb SS and SC disorders by the end of 1992. The centralization of the service has permitted rapid identification and resolution of problems.

Amniocentesis↗
PubMed1994

Genetic analysis of Cuban autosomal dominant polycystic kidney disease kindreds using RFLPs and microsatellite polymorphisms linked to the PKD1 locus.

We report on linkage analysis and haplotype characterization in 12 Cuban families with autosomal dominant polycystic kidney disease (ADPK) using PKD1-linked markers. They included both standard restriction fragment length polymorphisms (26.6., BLu24, and pGGG1) as well as microsatellite polymorphisms (CW2, 16AC2.5, and SM6). All of the examined families were fully informative for genetic diagnosis and no evidence of unlinked families was found. Analysis of two recombination events places PKD1 distal to the marker BLu24 and reduces the size of the region likely to contain the disease gene by approximately 300 kb. The allele frequencies of each marker were similar in the ADPKD and normal populations.

Alleles↗