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Biomedical subjects

A Aleixo

Publications and source records attributed to A Aleixo.

13 recordsLinked to original sources
PubMed2003

Expression at mRNA level of cytokines and A238L gene in porcine blood-derived macrophages infected in vitro with African swine fever virus (ASFV) isolates of different virulence.

Porcine macrophage cultures were infected with two ASFV isolates of variable virulence and mRNA levels of several relevant macrophage-derived cytokines were quantified by real time PCR. At six hours post infection, a clear enhancement of mRNA expression of TNFalpha, IL6, IL12 and IL15 was observed in macrophages infected with the low virulent ASFV/NH/P68 (NHV) when compared to those infected with the highly virulent ASFV/L60 (L60). The sequence of the A238L gene homologue to the cellular IkappaB was found identical in both viral isolates and its expression at mRNA level was higher in macrophages infected with NHV when compared to macrophages infected with L60. Furthermore our results suggest a negative correlation between the mRNA expression of A238L gene and the mRNA expression of the above mentioned cytokines (with the exception of IL10) in L60 infected macrophages in opposition to the positive correlation (with exception of the IL1) suggested in NHV infection. Overall, our data strongly emphasize that virulence of ASFV isolates may depend on their capacity to regulate the expression of macrophage-derived cytokines relevant for the development of host protective responses by yet unknown mechanisms triggered by the virus at early stages of the cellular infection.

African Swine Fever↗
PubMed2002

Blood group antigen profile predicted by molecular biology-use of real-time polymerase chain reaction to genotype important KEL, JK,RHD, and RHCE alleles.

The most clinically important blood group systems in transfusion medicine, excluding the ABO system, are the RH, Kell, and Kidd systems. Alloantibodies to antigens of these systems may be produced following blood transfusion or during pregnancy and can result in serious hemolytic transfusion reactions and hemolytic disease of the newborn. We developed rapid and robust techniques for RHD, RHCE, KEL, and JK genotyping with the use of a real-time polymerase chain reaction instrument. Two fluorescence-based methods for the detection of amplification products were used: for KEL1/KEL2, JK1/JK2, and RHE/RHe (exon 5) we used the hybridization probes protocol; for RHC/RHc the analysis was done in sequences of exon 1 for RHC and exon 2 for RHc; and for RHD, analysis was done in sequences of intron 4, exon 7, and exon 4 pseudogene using the SYBR Green I protocol. The genotyping tests were validated with samples from 85 Caucasian Portuguese and 15 Black European blood donors. Complete phenotype-genotype correlations were obtained. The potential use of the presented methods can be predicted in clinical transfusion medicine, allowing appropriate monitoring, early intervention, and improved care. When blood group genotyping techniques are necessary, this methodology is highly competitive for a routine laboratory.

Journal Article↗
PubMed2001

[Coronary angioplasty. Initial experience of the Santa Cruz Hospital].

The initial experience with percutaneous transluminal coronary angioplasty (PTCA) at Santa Cruz Hospital is presented. Between May and November 1984, ten patients with single significant (> 75%) coronary artery obstructions, 8 of the left anterior descending (LAD), 1 of the circumflex (Cx) and one of the right coronary artery (RCA), underwent coronary angioplasty using Gruentzig's technique and steerable catheters. Five patients were cases of chronic stable angina and 5 patients were cases of unstable angina, one of them of acute coronary insufficiency previously treated with intracoronary streptokinase. In every case was possible to cross the lesions which were proximal in 9 cases (7 of the LAD, 1 of the Cx and 1 of the RCA) and distal (LAD) in one case. Primary failure to dilate was seen in 2 cases of unstable angina due to pain and reversible ECG changes. In only 1 case there was occlusion at 9 hours after angioplasty which required emergency bypass operation. Although with a short follow-up, six patients are well and free of symptoms and in only 1 case there was recurrence of angina at four and a half months after PTCA. These results which represent the beginning of the learning curve are considered satisfactory and rewarding.

Adult↗
PubMed2001

Rapid genotyping of the major alleles at the Duffy (FY) blood group locus using real-time fluorescence polymerase chain reaction.

The Duffy blood group system has clinical importance due to involvement in transfusion reactions and hemolytic disease of the newborn. Recently, the molecular basis of the two alleles, FY*A and FY*B (125G>A), and the mutation situated in the promoter region of the FY gene (-33T>C), have been elucidated. In order to develop an accurate, easy, and rapid genotyping method, we describe a procedure using the LightCycler. Samples from 53 Caucasian Portuguese blood donors and 7 black, healthy, European individuals were phenotyped with commercial antisera. DNA was extracted from blood samples and the relevant sequences were amplified with the same cycling conditions, using real-time polymerase chain reaction. The melting point of the FY*A allele was 63 degrees C and of the FY*B allele, 55 degrees C. The allele without mutation at the promoter region had a melting point at 64 degrees C and the FY*B silent allele at 58 degrees C. The results in Caucasian individuals were similar to those found in European and American populations. When FY genotyping techniques are necessary, the methodology described is preferable to conventional methods as it is reliable, high speed, and uses small volumes, providing a highly competitive technology for use by a routine laboratory.

Journal Article↗
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↗
PubMed1989

Detection of rejection after heart transplantation. A computerized precordial mapping experience.

A low-cost modular compact personal computer-based system for surface precordial mapping (SPM) developed by the authors was used to detect rejection periods, documented by endomyocardial biopsy (EB), in heart transplant patients on cyclosporine A therapy. Data were collected with a matrix of 35 Ag-AgCl electrodes positioned over the precordio with anatomical references within 12 hours of EB. For each acquisition the authors computed the root mean square waveform from all signals collected to assess the accuracy of the maximum value of the RMS waveform (mRMS) parameter to detect rejection episodes. A mRMS variation of 20% in consecutive mapping acquisitions was the decision criterion. In EB, only presence or absence of acute rejection was considered. Eleven heart transplant patients were studied and 46 acquisitions were done. The mRMS obtained with SPM showed a sensitivity of 69% and a specificity of 91%, with a positive predictive value of 75% and negative value of 88%. The results indicate that surface precordial mapping may be promising for monitoring rejection.

Adolescent↗
PubMed1989

[Diagnostic value of the submaximal treadmill exercise test in the subacute phase of myocardial infarct].

OBJECTIVES: To assess the diagnostic value of treadmill submaximal exercise testing (TSET), early after myocardial infarction (MI) under medical treatment, evaluating the ST changes predominantly. MATERIALS AND METHODS: 65 patients, 62 males and 3 females, mean age 52 years with demonstrated MI under clinical, electrocardiographic and enzymatic criteria were evaluated with TSET before hospital discharge. Thrombolytic therapy in acute phase of MI was done in 45 of the patients. All patients underwent angiographic studies with left ventriculography and selective coronariography. RESULTS: Of all TSET variables considered (Treadmill time, ST segment, presence of chest pain, systolic pressure, double product and presence of ventricular arrythmias) the single most important predictor for high-risk groups like left main disease and three vessels disease, was ST changes alone or associated with exercise precordial pain, with a sensitivity of 100% to left main and 83% to three vessels disease. In the thrombolytic group we did not find any differences related with reperfusion. IN CONCLUSION: TSET is a useful, noninvasive, and safe method for risk stratification after MI mainly when ST segment changes are considered alone or with stress precordial pain, predicting high risk groups, namely left main or three vessels disease patients.

Adult↗
PubMed1987

Evaluation of 2 intravenous thrombolytic agents (anisoylated plasminogen streptokinase activator complex versus streptokinase) in patients with acute myocardial infarction.

Ten patients with symptoms of acute myocardial infarction of less than 6 hours duration were randomised to receive either anisoylated plasminogen streptokinase activator complex [APSAC] (30U) or streptokinase (1,500,000U) intravenously. The aims of the study were to compare the angiographic patency of the infarct-related coronary arteries and to monitor drug safety and tolerance for up to 24 hours. The left anterior descending artery was occluded in 3, the left circumflex in 3 and right coronary artery in 4 patients. Time between onset of pain and treatment ranged from 150 to 330 minutes. At 90 minutes, 8 patients, 3 of 5 (60%) of the APSAC group and all of the streptokinase group, had patent arteries. No significant differences were found in measurements of coagulation. There were no haemorrhagic complications. One patient of the APSAC group had reinfarction 6 hours after treatment and died in cardiogenic shock. APSAC seems safe and is easier to use than streptokinase, and both agents result in patency in the majority of patients, although too few patients were included to allow a valid comparison. However, thrombolysis should be considered only a temporary solution in acute myocardial infarction, associated mainly with 3-vessel disease.

Aged↗
PubMedDate not supplied

[The diagnostic and prognostic value of the 12-lead electrocardiogram in assessing the severity of coronary disease in the acute phase of an acute myocardial infarct].

UNLABELLED: The conventional twelve-lead electrocardiogram (ECG) still is the cheapest, most used and absolutely essential diagnostic method for the acute phase of myocardial infarction (MI) allowing risk stratification and coronary prognostic evaluation in this phase mainly by the localization of the ST segment depression and/or T wave inversion (ST/T changes) not related to the infarct area in Q-Wave MI or at any localization in case of non-Q wave MI. The etiology and pathophysiology of these ST/T changes in the setting of MI has been controversial. With the objective of determining ECG prognostic and diagnostic value, 70 patients (Pts) (59 men and 11 women, mean age 58 + 13) admitted in the acute phase of MI were studied with revision of acute phase ECG ST/T changes. All patients underwent coronary angiography and ventriculography at the moment of hospital discharge. Patients were divided into two classifications: A) MI localization: A1--Q-wave MI (anterior--20 pts, inferior--29 pts, lateral--1 pt); A2--non-Q wave--20 pts. B) Evidence of ST/T changes outside the infarct area in Q wave MI or at any localization in non-Q wave MI (group B1--with ST/T changes, group B2--without ST/T changes). We correlated the angiographically documented coronary artery disease in groups with ST/T changes and their localization. RESULTS: A1) Anterior MI group: in the 6 pts (30%) with "opposite" (inferior) ST/T changes, right coronary artery (RCA) disease was documented in 5 and in the other 14 patients the RCA did not show significant lesions. Inferior MI group: in the 24 Pts (83%) with "opposite" (precordial) ST/T changes. 23 of them had angiographic correlation (left anterior descending (LAD) and/or circumflex (CX) artery disease). Lateral MI group: one Pt with anterior wall ST/T changes and LAD and CX disease. A2) Non-Q wave group: in 13 pts (87%) the diseased vessels were correlated with the site of ST/T changes. B1) Q-Wave AMI: left main and 3-vessel disease in 2 pts, 3-vessel disease in 17 pts, 2-vessel disease in 9 pts, 1-vessel disease in 2 pts and non-significant disease in one pt. Non-Q wave MI: left main and 3-vessel disease in 1 pt, 3-vessel disease in 7 patients, 2-vessel disease in 3 pts and 1-vessel disease in 4 pts. B2) non-Q Wave MI: 3-vessel disease in 5 pts, 2-vessel disease in 7 pts, 1-vessel disease in 6 pts and non-significant disease in 1 pt. Non-Q wave MI: 2-vessel disease in 2 pts and non-significant disease in 1 pt. IN CONCLUSION: When pts were divided according to MI localization, a correlation was found between the ST/T changes outside the infarct area with CAD in 91% of Pts in the Q-Wave infarction group, with more significance in inferior and lateral MI. In the non-Q wave group, we found correlation between the a coronary lesions and the localization of ST/T changes in 87% of the pts. The pt group with ST/T changes presented, when compared with the pt group without these changes, evidence of more severe coronary artery disease (CAD): 3 vessels or left main with 3 vessel disease. However, only in the Q-Wave infarction group was a statistically significant difference found between the group with ST/T changes compared to the group without these changes, concerning to the existence of more severe coronary disease.

Acute Disease↗