Biomedical subjects

Isabel Monteiro

Publications and source records attributed to Isabel Monteiro.

5 recordsLinked to original sources

PubMed2005

Diffusion tensor imaging of frontal white matter microstructure in early Alzheimer's disease: a preliminary study.

Several investigators have suggested that the pathological progression of Alzheimer's disease appears to recapitulate the developmental maturation pattern, a process termed retrogenesis. Diffusion tensor imaging was used to test the hypothesis that the microstructural integrity of superior frontal and temporal white matter, one of the last regions to mature, would be reduced in vivo in early Alzheimer's disease. Five consecutive slices, from the orbitofrontal to periventricular frontal regions, as well as temporal and corpus callosal white matter regions, were sampled. Fractional anisotropy, mean diffusivity, axial diffusion, and radial diffusion of 10 patients with early Alzheimer's disease and 10 age-similar healthy control subjects were compared. Patients with Alzheimer's disease were found to have significantly reduced fractional anisotropy, increased mean diffusivity, and increased radial diffusion in superior frontal white matter. These data suggest that the integrity of periventricular frontal white matter rather than orbitofrontal white matter appears to be altered in early Alzheimer's disease and that the white matter abnormalities involve compromised myelin, consistent with the retrogenesis theory.

Aged↗

PubMed2005

Pulmonary embolism associated with a large tricuspid-related mass.

The case of a 43-year-old man with diabetes and alcoholism admitted to the emergency room with shock, fever, pleuritic chest pain and systemic symptoms is presented. Laboratory tests revealed anemia, leukocytosis, thrombocytopenia, high sedimentation rate and D-dimers, hypoxemia and hypocapnea. He also had sinus tachycardia, rSR' in V1 and an opacity on the periphery of the right pulmonary field. Blood and urine cultures were negative, as were serological markers. The echocardiogram showed a large mass adhering to the tricuspid valve, suggestive of myxoma. The patient underwent surgery, and anatomopathological examination of the mass showed it to be a bacterial vegetation, with no agent isolated. It is pointed out that differential diagnosis is difficult between a myxoma with systemic symptomatology associated with a possible pulmonary embolism, and tricuspid endocarditis with negative blood culture associated with a septic pulmonary embolism, which turned out to be the diagnosis in this patient.

Adult↗

PubMed2002

Erythrocyte damage and leukocyte activation in ischemic stroke.

BACKGROUND: The traditional lipid risk factors can only predict some of the cardiovascular events. Our work has focused on new potential biological markers of risk, namely leukocyte activation and erythrocyte membrane damage, in ischemic stroke cases. METHODS: Besides the traditional lipid profile, we evaluated the plasma levels of elastase and lactoferrin as markers of leukocyte activation, and membrane band 3 protein profile and membrane bound hemoglobin as markers of erythrocyte damage. Total and differential leukocyte counts and erythrocyte counts, hematocrit and hemoglobin concentrations were also evaluated. The lipid study included the evaluation of triglycerides, total cholesterol, high-density lipoprotein cholesterol (HDLc), low-density lipoprotein cholesterol (LDLc), apolipoprotein AI (Apo AI) and B (Apo B), and lipoprotein (a) (Lp(a)). The work was performed in a control group (n=29) with no history of cardiovascular events, presenting normal hematological and lipid values, and in a pathologic group (n=21) of ischemic stroke cases diagnosed by computed tomographic imaging. RESULTS: We found that ischemic stroke was associated with significantly higher values of leukocytes, which seem to be activated, as shown by significant higher levels of elastase and lactoferrin. This activation seems to impose erythrocyte damage, as suggested by a significant increase in membrane bound hemoglobin and by a different band 3 profile. CONCLUSIONS: Our data suggest that plasma levels of elastase and lactoferrin, together with levels of erythrocyte membrane bound hemoglobin and band 3 profile, could be used as powerful new markers of risk for cardiovascular events.

Adult↗

PubMedDate not supplied

Transesophageal echocardiography in an emergency setting. A district general hospital experience.

Transesophageal echocardiography is an extremely useful technique for the study of various cardiovascular pathologies. In the particular setting of emergency, it is of great value for prompt diagnosis and appropriate therapy. It was our aim to evaluate, in our hospital, the benefits obtained by the use of transesophageal echocardiography in an emergency setting. We retrospectively studied patients who underwent transesophageal echocardiography (TEE) in an emergency setting, from June 1997 to December 2002, evaluating demographic characteristics, indication to perform TEE, benefit obtained (diagnosis or exclusion of initial diagnosis), and technique-related complications. There were 97 transesophageal echocardiograms performed in an emergency setting in the period under consideration, accounting for 19.3% of the total number of exams. Fifty-two patients (53.6%) were male, mean age 63.9 +/- 12.7. Nineteen patients (19.6%) were on assisted ventilation. The indications to perform TEE were: possible massive or submassive pulmonary thromboembolism in 32 patients (33.0%); suspected aortic dissection in 19 (19.6%); shock with inconclusive transthoracic echocardiogram in ten (10.3%); possible endocarditis in eight (8.2%); possible prosthetic valve dysfunction in seven (7.2%); intracardiac mass in six (6.2%); search for cardiac source of embolism in five (5.2%); possible mechanical complication of acute myocardial infarction in four (4.1%); pre-electrical cardioversion study in four patients with atrial fibrillation (4.1%); and suspected congenital heart disease in two (2.1%). TEE examination yielded additional information and helped in the therapeutic decision in 88 patients (90.7%), leading to a diagnosis in 49 (50.6%), which was different from the initial diagnostic hypothesis in four, and exclusion of the suspected diagnosis in 39 (40.1%). There was only one minor complication (1.0%) and no TEE-related mortality. We concluded that transesophageal echocardiography is an extremely useful and safe cardiovascular diagnostic technique in an emergency setting in a district general hospital, enabling a diagnosis to be reached or excluded in almost all patients, which is essential for implementing appropriate therapy.

Adult↗

PubMedDate not supplied

Aortic dissection.

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Adult↗