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Biomedical subjects

A T Pereira

Publications and source records attributed to A T Pereira.

14 recordsLinked to original sources
PubMed2000

Tissue Doppler imaging in different locations of the mitral annulus: all different or all the same?

BACKGROUND: The assessment of the mitral annulus motion with tissue Doppler imaging is claimed to be an accurate method to quantify global left ventricular systolic and diastolic function. However, it is not yet perfectly defined which site of the annulus must be selected. Familial amyloidotic polyneuropathy of the Portuguese type (FAP) is an hereditary systemic disease in which diastolic dysfunction may occur. AIM: 1--To determine if in FAP patients the mitral annulus motion is independent of the selected site. 2--To compare pulsed wave Doppler parameters with tissue Doppler parameters in the different annular sites. METHODS: Of 24 FAP patients studied, 14 were included. In each patient we performed conventional transmitral pulsed wave Doppler and tissue Doppler in the 4 sites of the mitral annulus and measured the velocities of the rapid filling wave e, of the atrial contraction wave a and calculated e/a ratio. RESULTS: According to the transmitral inflow profile, patients were divided in 2 groups: Group I--normal global diastolic function and Group II--abnormal relaxation. Group I--33% of these patients showed e/a > 1 in the four sites and 67% showed e/a > 1 in at least 1, but not in all the sites. The rate of normal sites per patient was 3.1. Group II--25% of these patients showed e/a < 1 in the 4 sites of the annulus and 75% had e/a < 1 in at least 1, but not in all the sites analysed. The rate of abnormal sites/patient was 3.1. in this group. When conventional and tissue Doppler data were compared (bland and altman) the septal portion of the annulus was the one with the best correlation. CONCLUSIONS: 1--The assessment of the mitral annulus motion with tissue Doppler imaging is dependent on the site selected for study. 2--The septal site was the one that showed the highest correlation and concordance between pulsed wave Doppler and tissue Doppler. 3--The relative number of normal versus abnormal sites was determinant of the transmitral pattern. 4--Tissue Doppler imaging identified: a) among patients until now classified as normal diastolic function, a subgroup of patients with abnormal function in some sites of the annulus and b) among patients with abnormal relaxation, a subgroup with normal diastolic function in some sites of the annulus.

Adult↗
PubMed2000

[Diastolic dysfunction and left ventricular hypertrophy in familial amyloidotic polyneuropathy: a cause-effect relationship?].

UNLABELLED: TTR Met30 Familial Amyloidotic Polyneuropathy of the Portuguese type (FAP) is an incapacitating and lethal hereditary disorder that affects predominantly young adults of both genders. Portuguese type FAP patients have sensory, motor and autonomic polyneuropathy. The generalised systemic amyloid infiltration involves the heart, leading to the characteristic granular bright sparkling echocardiographic pattern. LV wall thickening occurs in the late phases of the disease. LV diastolic dysfunction has been reported in the absence of systolic dysfunction; an abnormal diastolic transmitral flow pattern assessed by pulsed wave Doppler (PW) was described. PW is very much dependent on load conditions. Tissue Doppler imaging (TDI) has been used as a more reliable method to assess long axis diastolic function. OBJECTIVE: 1--To identify the incremental value of TDI in the assessment of diastolic function in FAP. 2--To correlate diastolic pattern abnormalities and left ventricular mass index (LVMI) in FAP patients. METHODS: We performed a prospective evaluation of 24 consecutive FAP patients and selected 14 (sinus rhythm, age < 45 years). Diastolic function was assessed by PW and classified as normal (GI-E/A > 1) or abnormal (GII-E/A < 1). TDI was performed in 4 sites of the mitral annulus (septum, lateral, inferior, anterior). Velocities of the rapid filling wave (E') and atrial contraction wave (A') were measured and E'/A' calculated. In each site we considered the TDI as normal (E'/A' > 1) or abnormal (E'/A' < 1). The LVMI was calculated by Devereux's formula. RESULTS: Age, gender and heart rate were similar in both groups. TDI at the septal mitral annulus was normal in all of the GI patients (E'/A': 1.29 +/- 0.19) and suggestive of abnormal LV relaxation in all of the GII patients (E'/A': 0.82 +/- 0.11, p < 0.0001). TDI revealed abnormal diastolic pattern when a restricted number of sites of the mitral annulus were assessed, even in GI patients and before PW abnormalities occurred. Fractional shortening (FS) and LVMI were similar in GI and GII (FS-GI: 45.5 +/- 5.3, GII 43.5 +/- 8.1%, p: NS; LVMI--GI: 66 +/- 9.3, GII: 67 +/- 3.0 g/m2 p: NS). CONCLUSION: The assessment of mitral annulus motion has introduced new data in the study of diastolic function of FAP patients. An abnormal LV relaxation pattern occurred early in the evolution of the disease in patients with normal LVMI and systolic function.

Adult↗
PubMed1995

[Sudden death in hypertrophic myocardiopathy].

Sudden death is a very important event in the natural history of hypertrophic cardiomyopathy. Although its physiopathology is not still fully understood, there are several potential mechanisms to explain it, such as electrical, ischemic and hemodynamic events. It is thought that these mechanisms vary from patient to patient and that more than one mechanism may coexist in a specific patient. Risk factors for sudden death in hypertrophic cardiomyopathy are clinical, genetical and electrical. Risk stratification implies aggressive investigation (electrophysiological study and/or forearm plethysmography during exercise and/or tilt test) in order to identify the most probable mechanism involved in each case and to select individualized preventive measures (pharmacological, surgical, implantable cardioverter defibrillator). The role of amiodarone is still controversial because of contradictory results with this drug in this illness.

Amiodarone↗
PubMed1995

[The treatment of obstructive hypertrophic myocardiopathy refractory to medical therapy].

Until a few years ago, therapy of refractory Hypertrophic Obstructive cardiomyopathy was mainly surgical--Morrow's myotomy/myectomy or mitral valve replacement. Despite the good results of these techniques, they are not free of mortality and morbidity. In the last years a new and promising therapy has been developed: the Dual Chamber Pacemaker. Technically easier and less invasive than surgery, this therapy has achieved better results and lower mortality and morbidity during the follow-up.

Cardiomyopathy, Hypertrophic↗
PubMed1991

[Visualization of thrombi in the left auricular appendix using transesophageal echocardiography. Apropos of a clinical case].

A case of Transesophageal Echocardiography (T.E.E.) Assessment of "Rheumatic Mitral Stenosis" is presented. T.E.E. has been recently referred as having superior resolution than transthoracic Echocardiography on the detection of thrombi. In the presented case a thrombi was detected in the left atrial appendage. This fact has allowed a better planning of surgery.

Echocardiography↗
PubMed1989

Plasmid analysis of 219 methicillin-resistant Staphylococcus aureus strains with uncommon profiles isolated in Lisbon.

During the years 1986 and 1987, 219 methicillin-resistant Staphylococcus aureus (MRSA) strains were isolated in a Lisbon hospital. Antimicrobial susceptibilities and genetic analysis showed that resistance to penicillin, methicillin, erythromycin (inducible phenotype), tetracycline, gentamicin, tobramycin, kanamycin, streptomycin, neomycin and trimethoprim were chromosomally encoded. Plasmid DNA was absent from 38.8% of the isolates. Constitutive erythromycin resistance was coded by three plasmids of c. 2.3 Md, c. 2.0 Md and c. 1.6 Md. Chloramphenicol resistance was mediated by two plasmids of c. 2.9 Md and c. 1.8 Md. Small cryptic plasmids of c. 1.65 Md, c. 1.2 Md and c. 1.0 Md were also detected. The majority of the strains revealed antigen 17, were lysed by phages 75, 89 and/or 85, and were either devoid of plasmid DNA, or possessed a c. 1.6 Md plasmid coding for constitutive erythromycin resistance or a c. 1.0 Md cryptic plasmid. These observations cannot rule out that the MRSA Lisbon isolates are a homogeneous group of strains that might have a common origin, and seem to be different from MRSA recently isolated in other countries.

DNA, Bacterial↗
PubMed1989

Diversity of plasmids in Staphylococcus saprophyticus isolated from urinary tract infections in women.

A group of 150 Staphylococcus saprophyticus strains isolated from urinary tract infections in women were included in this study. Antimicrobial susceptibility tests showed that these isolates were sensitive to most antimicrobial agents. All strains were sensitive to penicillin, cephalothin, gentamicin, kanamycin, trimethoprim and nitrofurantoin. Resistance to tetracycline was present in 10.6% of the strains, to chloramphenicol in 4%, to erythromycin in 1.3% and to streptomycin in 1.3%. All strains were resistant to cadmium chloride as well as to novobiocin and nalidixic acid. Plasmid analysis showed that 82% of the strains harboured plasmids, some of them with complex plasmid profiles. Most plasmids were considered to be cryptic, although antibiotic resistance plasmids were identified in 18 isolates. Tetracycline resistance was encoded by a plasmid of c. 2.8 MDa, chloramphenicol resistance by a plasmid of c. 2.9 MDa and erythromycin resistance by a plasmid of c. 1.6 MDa. Streptomycin resistance could not be linked to the presence of any specific plasmid. Plasmid profiling seemed to be a good method for differentiating among S. saprophyticus strains.

Drug Resistance, Microbial↗
PubMed1987

Mannose inhibition as a significant marker for differentiating among novobiocin-resistant staphylococci of relevance in clinical microbiology.

A specific method for the identification of Staphylococcus saprophyticus among novobiocin-resistant species isolated from man is described. The test is based on novobiocin resistance, non-fermentation of D-mannose and early inhibition with late secondary growth on glucose/mannose + novobiocin agar plates. On this medium novobiocin-resistant Staphylococcus cohnii showed a confluent, continuous and homogeneous growth after 24 h which remained unchanged at 48 h whether or not it fermented D-mannose, whereas novobiocin-resistant Staphylococcus xylosus fermented D-mannose. These results are discussed in relation to a possible causal role of PTS enzymes and phosphomannose isomerase deficiency in mannose inhibition.

Drug Resistance, Microbial↗
PubMed1986

Methicillin-resistant Staphylococcus aureus: a 6-month survey in a Lisbon paediatric hospital.

The prevalence of nasal colonization and infection with methicillin-resistant Staphylococcus aureus (MRSA) among patients and staff was studied in a section of a Paediatric Surgical Unit in Lisbon between February and July 1985. Nasal colonization was demonstrated in 41% of burned patients, 5% of non-burned patients and 35% of the nurses. Infection by MRSA occurred in 30% of the burns. The isolates had identical serological patterns, slight differences on phage typing and were resistant to methicillin, cephalosporins, tetracycline, erythromycin and aminoglycosides. A chloramphenicol resistance plasmid of 3 Md was present in those isolates which were chloramphenicol resistant and a small plasmid of 1.7 Md which coded for constitutive erythromycin resistance was present in many isolates. Gentamicin, tetracycline and inducible erythromycin resistance were chromosomal. Several reasons for the apparent low virulence of the isolates are discussed. Attempts to control the outbreak by the discharge of colonized or infected patients, improvement of nursing practices and treatment with temporary removal from work of the colonized nurses did not eliminate the organism from the unit.

Burns↗
PubMed1985

Infection with methicillin-gentamicin-resistant Staphylococcus aureus strains in a paediatric surgical unit in Lisbon.

The first description in Portugal of the spread of a methicillin-gentamicin resistant Staphylococcus aureus (MGRSA) epidemic strain in a hospital unit is reported. Ten in-patients, out of a selected group of 200, were colonized by the epidemic strain. The strain was also isolated from one burn and from the nose of three nurses. Possible reasons for the apparent reduced communicability and low virulence of the multi-resistant strain are presented.

Cross Infection↗
PubMed1981

Further studies on antigen variation in Staphylococcus aureus.

The plating of successive Staphylococcus aureus subcultures of daily transfers proved that discontinuous variation resembling a genetic mutation and selective outgrowth of the variant are responsible for antigen variation. Every subculture of S. aureus, when repeatedly transferred, contained a mixture of cells with original antigen 17 (or 13) and final antigen 1 (or 3) that are relevant for research, serological diagnosis, and epidemiological study of staphylococcal diseases.

Antigens, Bacterial↗
PubMed1975

[Arterial vascularization of the sino-auricular node of the heart in dogs].

In order to study the arterial blood supply of the sinus atrial node in the Dog, the authors have performed the post-mortem injection of the arterial branches going to this node. They observed 65 cases and they came to the following conclusions: in 31 cases (47.7%) the sinus atrial node is supplied by the artery of the sinus atrial node and by the anterior atrial artery, branch of the circumflex; in 20 cases (30.8%) besides the two arteries already mentioned there was also the anterior branch from the first portion of the right coronary artery; in 13 cases (20%) the sinus atrial node was exclusively supplied by the artery of the sinus atrial node and in one case (1.5%) it was supplied only by the first anterior atrial branch of the circumflex artery. Their findings are different from those of other authors and they attribute the failure in provoking experimental ischemia of the sinus atrial node in the Dog, to the rich blood supply of this node and to the different origins of the vessels supplying it.

Animals↗