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Biomedical subjects

J Sedat

Publications and source records attributed to J Sedat.

At least 19 recordsLinked to original sources
PubMed2002

Endovascular treatment of ruptured intracranial aneurysms in patients aged 65 years and older: follow-up of 52 patients after 1 year.

BACKGROUND AND PURPOSE: We sought to describe the clinical outcome and results obtained in the endovascular therapy of ruptured cerebral aneurysms in the elderly over an 8-year period. We compared endovascular therapy results in patients aged > or =65 and <65 years. METHODS: During 1993-1999, 52 patients aged 65 to 85 years (mean age, 71.5+/-4.7 years) were embolized with the use of Guglielmi detachable coils (group I). During the same period, 143 patients aged <65 years (mean age, 47+/-11 years) with ruptured cerebral aneurysm were treated with the same technique (group II). A clinical assessment was made on admission with the Hunt and Hess (HH) classification and again in the 12th month with the Glasgow Outcome Scale (GOS), with arteriographic control in months 3 and 12. RESULTS: In group I, clinical grades on admission were as follows: HH 1, 9.5%; HH 2, 33%; HH 3, 21%; HH 4, 34.5%; HH 5, 2%. Outcome was favorable in 48% of patients (GOS 1 or 2); the mortality rate was 23%. No rebleeding was observed. Patients presenting lesions > or =10 mm had an unfavorable outcome in >77% of cases. Thromboembolic complications were present in 13% of cases. In group II, clinical grades on admission were as follows: HH 1, 14.5%; HH 2, 47%; HH 3, 11%; HH 4, 24%; HH 5, 3.5%. Favorable outcome (GOS 1 or 2) was observed in 77% of cases, with 14% mortality. Complications due to the endovascular procedure were present in 4.2% of cases. Patients with HH grades 1 or 2 on admission showed a positive outcome (GOS 1 or 2) in 77% of cases in group I and in 88.5% of cases in group II. Mortality was 9% in the first subgroup compared with 2.8% in the second. Patients who had a high clinical grade on admission (HH 4 or 5) showed a favorable outcome (GOS 1 or 2) in 16% of cases in group I compared with 41% in group II. CONCLUSIONS: Endovascular treatment of ruptured intracranial aneurysms in patients aged > or =65 years appears to be effective against rebleeding and represents an alternative to surgery. However, perioperative thromboembolic complications are more frequent in the elderly population.

Adolescent↗
PubMed1995

[Giant bronchopyocele. General and radiological characteristics. Apropos of a case].

A case of giant bronchocele is reported. This lesion is due to a mucus and pus filled dilatation of the bronchial tree proximal to a stenosis. The latter can be either congenital or acquired, or in the context of a diffuse bronchopathy, which can be responsible for a functional stenosis. Both plain radiography and computed tomography findings are diagnostic. The etiology of the abnormality however represents an important problem to be solved. Further, a thoractomy is often necessary, except in those case arising in the context of a diffuse bronchopathy, which usually resolve either spontaneously or following medical treatment.

Bronchi↗
PubMed1994

Magnetic resonance imaging of von Meyenburg complexes: report of a pathologically documented case.

Von Meyenburg complexes (VMC) are rare malformations of the bile ducts. They are usually associated with adult dominant polycystic disease (ADPCD). Although generally benign, they may give rise to cholangiocarcinomas. Herein, we report the third MR documented case of VMC. The comparative diagnostic value of ultrasound (US), computed tomography (CT), and magnetic resonance (MR) examinations is discussed.

Aged↗
PubMed1994

[1,5 Tesla MRI in focal nodular hyperplasia. Review of the literature apropos of 7 cases].

Six patients with 7 focal nodular hyperplasia lesions were investigated with 1.5 Tesla magnetic resonance imagery (MRI). Surgical specimens were obtained in all cases and histological examination confirmed the diagnosis of focal nodular hyperplasia. In all cases, the tumour was isointense on the T1 weighted sequences. On the T2 weighted sequences in six cases, the tumour gave a hypersignal compared with the surrounding healthy liver tissue. Central scar tissue was found in all the lesions. On the T2 weighted images, the center gave a hypersignal 4 times and a hyposignal 3 times. Gadolinium injection on the echo gradient sequences (GRASS) showed product uptake suggestive of vessels within the central scar in one case. The report in the literature confirm the variability of focal nodular hyperplasia depending on the magnetic field used. In 1.5 Tesla MRI an isointense signal on at least one sequence would appear to be sufficient for the diagnosis of focal nodular dysplasia if the tumour is homogeneous and if the central scar is hyperintense in T2 sequences.

Adolescent↗
PubMed1993

Chest wall invasion by bronchogenic carcinoma: evaluation with MR imaging.

The value of magnetic resonance (MR) imaging and the roles of various pulse sequences and contrast medium enhancement in detection of chest wall invasion were evaluated in 34 patients with primary bronchogenic carcinoma. Results were correlated with clinical data and computed tomographic studies. MR imaging criteria of parietal invasion included signal intensity identical to that of the tumor on T1-weighted images, intraparietal hyperintense signal of the tumor on T2-weighted images, and intraparietal enhancement with T1-weighted imaging and gadoterate meglumine administration. Twenty patients had parietal involvement, and MR imaging was positive in 18 of the 20 (sensitivity, 90%). Two false-positive errors occurred among the 14 patients without parietal involvement (specificity, 86%). T2-weighted sequences had a sensitivity of 65% (11 of 17 cases). Contrast-enhanced and non-contrast-enhanced T1-weighted sequences had the same sensitivity, but contrast medium uptake was revealed in two patients without parietal involvement. Good spatial resolution appears to be the main factor for detection of parietal invasion.

Adult↗
PubMed1993

[Kaposi sarcoma of the lungs in patients with acquired immunodeficiency syndrome (AIDS). Thoracic radiography and scanning].

Twenty-four patients with AIDS presenting with Kaposi's sarcoma of the lung were retrospectively studied to assess the merits of thoracic radiographs and of CT for the diagnosis of this disease. Evidence for Kaposi's sarcoma of the lung was given by a characteristic fiberendoscopic appearance in 10 cases and by the histologic diagnosis in 14 cases. All patients had chest radiographs and 14 patients a concomitant thoracic CT study. Chest radiographs showed perihilar opacities in 18 patients, nodules in 8, mediastinal and/or hilar adenopathies in 2 and pleural effusion in 16. Comparison of the patients who had had thoracic radiographs and a CT scan showed better detection of adenopathies, described in 2 cases on chest radiographs and 7 on CT scans, and of nodules, detected in 5 cases on chest radiographs and 6 on CT scans. In 12 patients with perihilar opacities on thoracic radiographs, CT provided a better view of the peribronchovascular distribution of these opaque areas. In 1 patient, CT showed peribronchovascular thickening while radiographs were normal. In 1 patient, both examinations were normal. This study emphasizes the merits of thoracic radiographs and, even more, of CT for the diagnosis of Kaposi's sarcoma of the lung. Peribronchovascular thickening appears to be a characteristic sign that is well analyzed with computed tomography. Since histological evidence of Kaposi's sarcoma is rarely obtained because of the aggressive nature of biopsies in such patients, CT has an important role for the diagnosis of this condition.

AIDS-Related Opportunistic Infections↗
PubMed1990

Anatomical study of the temporal lobe. Correlations with nuclear magnetic resonance.

Following a brief review of embryogenesis and phylogenesis, the different anatomical structures of the temporal lobe of the brain are described. This lobe has 4 surfaces: lateral, inferomedial, superomedial and superior. The first 2 surfaces, visible on the lateral and inferior aspects of the cerebral hemisphere, are composed of 5 temporal gyri. The superomedial and superior surfaces do not show and must be made visible by a digital or instrumental manipulation. The hippocampal formation, surrounded by the temporal horn of the lateral ventricle medially, the choroid and transverse fissures laterally and the amygdaloid complex anteriorly, forms the superomedial surface and represents the "rhincendephalic" part of the temporal lobe. The superolateral surface, which is the superior surface of the first temporal gyrus, is buried deeply in the fissure of Sylvius and is divided into 3 parts: the planum polare, the gyri of Heschl and the planum temporale. Two categories of fibres are present in the white matter of the temporal lobe: projection fibres (acoustic radiation, optic radiation, temporo-pontine tract, temporo-thalamic fasciculus) and association fibres (cingulum, anterior longitudinal, uncinate, superior occipitofrontal, superior longitudinal fasciculi). The anatomical temporal lobe exploration by MRI was carried out with inversion-recovery sequences performed in all three dimensions. The authors describe the advantages and limitations of MRI and indicate the most appropriate plane(s) for the study of the various temporal structures, with emphasis on coronal on coronal and sagittal sections.

Adult↗
PubMed1983

Nuclear structure: determination of the fate of the nuclear envelope in Drosophila during mitosis using monoclonal antibodies.

Libraries of monoclonal antibody against nuclear proteins of Drosophila melanogaster have been established recently to investigate nuclear structure and function. Some of the antibodies have been characterized as being directed against the nuclear envelope. Further studies detailed in this paper describe the fate of the nuclear envelope during mitosis. Indirect immunofluorescence staining of whole developing Drosophila embryos has been used as a system in which nuclear events can be studied both synchronously and in a longitudinal gradient of mitotic structures. The results show a pattern of breakdown and reconstruction of the nuclear envelope in which the antigen is always present in particulate structures. In addition, the processes of antigen rearrangement are shown to be spatially determined throughout mitosis.

Animals↗
PubMed1980

Soft x-ray lithographic studies of interphase chromosomes.

Soft x-ray absorption lithograph patterns of purified interphase human nuclei and chromosome arrays, imaged on PMMA resists, were examined by scanning EM. The patterns obtained were compared to those utilizing more conventional sources, including transmission EM, scanning EM, high voltage EM, and various light microscopic techniques. The x-ray resist images revealed orderly arrays of absorption profiles in the 3-dimensional specimen with both mild and more extensive developments of the resist. Dense chromatin at the edge of interphase nuclei revealed aligned periodic peaks on the order of 2200 A diameter, with substructure. The periodicity and alignment of interphase chromosomes were entirely consistent with birefringent data on nuclei indicating a high degree of 3-dimensional order. This degree of 3-dimensional order was observed in nuclei containing essentially DNA and histones with only very few other minor (probably structural) proteins. Sonication and nuclease treatment to disperse interphase chromosomes revealed similar absorption periodicities in individual chromosome fibers. Analysis of x-ray absorption profiles thus appears to offer significant new insights into the ordered structure of these defined biological specimens.

Cell Cycle↗
PubMed1977

High-resolution soft x-ray microscopy.

X-ray micrographs of biological materials have been obtained with a resolution better than 100 angstroms by using x-ray resist as the recording medium. A high-resolution scanning electron microscope with a short-focal-length final lens, operating in the "low-loss" mode, is used to make the smallest features in the x-ray replica visible.

Animals↗