Safety of dipyridamole testing in patients with cerebrovascular disease.
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Aged↗
Biomedical subjects
G Bisson
Publications and source records attributed to G Bisson.
Cooperative computer system for genome sequence analysis.
Analysis of the huge volumes of data generated by large scale sequencing projects clearly requires the construction of new sophisticated computer systems. These systems should be able to handle the biological data as well as the results of the analysis of this data. They should also help the user to choose the most appropriate method for a simple task and to string together the methods needed to solve a global analysis task. In this paper we present the prototype of a software system that provides an environment for the analysis of large-scale sequence data. In a first approach this environment has been put to the test within the B. subtilis sequencing project. This system integrates both a descriptive knowledge of the entities involved (genes, regulatory signals etc.) and the methodological knowledge concerning an extendable set of analytical methods (i.e. how to solve a sequence analysis problem through task decomposition and method selection). A knowledge representation based on two existing object-oriented models, named Shirka and SCARP, is used to implement this integrated system. In addition, the present prototype provides a suitable user interface for both displaying the results generated by several methods and interacting with the objects. We present in this paper an overview of the knowledge-based models used to build this integrated system, and a description of the way in which biological entities and sequence analysis tasks are represented. We give illustrations of the co-operation between user and system during the problem solving process. Such a system constitutes a computer workbench for molecular biologists studying the genetic programs of living organisms.
Bacillus subtilis↗
APIC: a generic interface for sequencing projects.
In this paper, we describe the APIC graphical interface that aims at displaying the results produced by the genomic sequence analysis methods and at helping a comparison of these results. The major feature of APIC lies in its genericity. As a matter of fact, this interface can obviously be used to visualise genetic or physical maps but it also able to display other kinds of information such as curves or pictures. On the one hand, APIC provides the biologist who builds a new sequence analysis method with a standard interface allowing to display his results. Thus, he can avoid implementing a specific visualisation tool. On the other hand, even when the methods already have their own interfaces, using APIC has the advantage of giving a homogeneous way to compare several results coming from different analysis tools. Moreover, it provides some powerful functions for navigating and browsing into the results.
Base Sequence↗
Rapid washout of technetium-99m-MIBI from a large parathyroid adenoma.
We report a case of rapid 99mTc-methoxyisobutylisonitrile (MIBI) clearance from a parathyroid adenoma. A double-phase 99mTc-MIBI parathyroid scintigraphy was performed on a 62-yr-old female evaluated for primary hyperparathyroidism. A large parathyroid adenoma was visualized caudal to the left lobe of the thyroid gland with an unusually rapid washout of the tracer from tumor tissue. Histologic tissue examination confirmed the presence of a parathyroid adenoma and the absence of oxyphil cells. Care should be taken in interpretation of 99mTc-MIBI parathyroid scintigrams because some adenomas can present a rapid release of the radiotracer in a double-phase study. Technetium-99m-MIBI retention could be related to the number of mitochondria-rich cells in parathyroid adenomas or to hyperplasia.
Adenoma↗
Tl-201 chloride bone marrow uptake in a patient with minor thalassemia.
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Aged↗
Evaluation of a 99mTc-antimyosin kit for myocardial infarct imaging.
The Fab fragment of a mouse monoclonal antibody AM(3-48) that recognizes alpha and beta-heavy chains of human atrial and ventricular myosin and beta-heavy chain of human slow skeletal muscle myosin [CardioVisionTM] was labeled with 99mTc using stannous reductant in a simple, instant kit method. The infarcted heart uptake in dogs of 99mTc-AM(3-48)Fab' was compared with that of established radiopharmaceuticals routinely used for cardiac imaging in humans. The dog infarct was induced by bringing a catheter from the femoral artery to the coronary artery where an artificial blood clot was generated. The 99mTc-AM(3-48)Fab' preparation was selectively taken up by infarcted myocardium, resulting in diagnostic quality images of the infarcted area as early as 6 hour post-injection, rendering CardioVisionTM particularly useful for SPECT imaging. Good agreement was found between the images obtained with 99mTc-Pyrophosphate and those obtained with 99mTc-AM(3-48)Fab', while the infarcted area was clearly delineated as a cold spot with 99mTc-MIBI or 201 Tl-thallous chloride. The biodistribution of 99mTc-AM(3-48)Fab' was also studied in healthy and isoproterenol-infarcted rats, from which dosimetry values in man were extrapolated. The data indicate that the kidneys will receive the highest radiation dose and that they will be the main contributors to the total radiation burden, which was estimated at 0.005 rad/mCi.
Animals↗
Newer technetium-99m--labeled myocardial perfusion imaging agents: clinical indications.
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Coronary Disease↗
Thallium-201-dipyridamole imaging: comparison between a standard dose and a high dose of dipyridamole in the detection of coronary artery disease.
UNLABELLED: The purpose of this study was to compare two different doses of dipyridamole as a pharmacologic stress test for 201Tl imaging. METHODS: Twenty-four patients with significant coronary artery disease (15 had undergone a coronary angiogram and 9 had undergone a previous 201Tl study with a significant lesion) were prospectively studied. Within 1 wk, all patients underwent two 201T-dipyridamole myocardial planar studies, one using a standard dose (STD) and the other, a high dose (HIGH) of dipyridamole. The protocol order was randomly assigned. The STD protocol used a dose of 0.14 mg/kg/min for a duration of 4 min (0.56 mg/kg), and the HIGH protocol used a dose of 0.14 mg/kg min for a duration of 6 min (0.84 mg/kg). The 201Tl was injected 3 min after the end of the dipyridamole infusion. Images, obtained 5 min and 4 hr later, were interpreted (divided into five segments each) by three blinded observers. RESULTS: The STD protocol showed normal, ischemia and scar in 252, 91 and 17 segments, respectively. The HIGH protocol detected 232, 118 and 10 segments, respectively. A side-by-side evaluation was done to evaluate the defect extent subjectively, which was greater with HIGH in 14, equal in six and smaller in four patients. One or more side effects were seen in 14 patients with STD and in 19 with HIGH. Increased heart rate (8 bpm for STD and 19 bpm for HIGH, p < 0.001) was the only significant change seen in the hemodynamic parameters. CONCLUSION: This preliminary study indicates that a high dose of dipyridamole seems to be safe and can be helpful to increase the sensitivity of 201Tl imaging.
Coronary Disease↗
Diffuse lung uptake of technetium-99m sulfur colloid in malaria.
Diffuse lung accumulation of colloid was seen on liver-spleen imaging in a patient during the acute stage of vivax malaria. A repeat study was performed following successful therapy and showed complete disappearance of lung uptake. Possible mechanisms for this unusual observation are discussed, with the conclusion that this phenomenon is probably related to increased reticuloendothelial system activity, due to a malaria-induced increase in the pulmonary macrophages.
Adult↗
Gallium-67 citrate accumulation in a mycotic popliteal artery aneurysm.
A 31-year-old man with bacterial endocarditis developed a mycotic popliteal aneurysm which presented clinically like an acute osteomyelitis. Bone and Ga-67 scanning played a major role in disclosing this unsuspected lesion. Various isotopic techniques proposed for the detection of mycotic aneurysm are reviewed. The potential usefulness of Ga-67 imaging in patients at risk of developing such lesions is discussed.
Adult↗
Imaging the pneumoconioses: a multidisciplinary approach.
The initial early reaction of pulmonary tissue to inorganic dust inhalation is a fibrosing macrophagic alveolitis. This initial pulmonary lesion can be detected by an enhanced gallium 67 pulmonary uptake and analyses of bronchoalveolar lavage. These two techniques can document not only the increased proliferation of macrophages, but also the activation of macrophages to produce excessive amounts of fibronectin and other factors of fibroblastic growth implicated in the pathogenesis of the pneumoconioses. Of equal clinical interest is the development of computed tomography, which has permitted better characterization of the early stages of fibrosis in the pneumoconioses. These refinements in disease recognition will contribute to the earlier detection of pneumoconioses before they become incapacitating. Newer therapeutic methods are also under investigation that could permit inactivation of either the dust itself or the pulmonary macrophage. The coupling of these new diagnostic and therapeutic developments will bring in a new era in occupational pulmonary medicine.
Bronchoalveolar Lavage Fluid↗
[New methods in the early detection of pulmonary fibrosis in asbestosis and silicosis].
Much recent work in thoracic medicine has been slanted towards the early detection of respiratory disease and the prevention of disabling sequelae. In the field of pneumoconioses associated with inhalation of mineral dust the interest of research workers has been largely orientated towards the objectives of early detection and the prevention of fibrotic scarring. To achieve real progress the research workers have used new investigational techniques such as axial tomography of the thorax, quantitative scintigraphy using Gallium-67 and analyses of bronchiolar lavage in parallel with a traditional approach, namely: a clinical examination of the patient, a pulmonary radiograph and respiratory function tests. These studies have enabled further clarification of the specific value of each of these new methods of investigation, whether at the level of early detection, the early recognition of pulmonary fibrosis, the characterisation of the current state of the disease and the prediction of fibrogenic power. Several different forms of intervention on the fibrotic process are currently under trial and may contribute to the prevention of pulmonary fibrosis.
Asbestosis↗
Quantitative gallium 67 lung scan to assess the inflammatory activity in the pneumoconioses.
Gallium 67 lung scan has recently become increasingly used to evaluate the biological activity of alveolitis of interstitial lung diseases and to stage the disease process. In order to have a more precise and objective indicator of the inflammatory activity in the lung, we and others have developed computer-based quantitative techniques to process the 67Ga scan. In this report, we compare the results of three such computer-based methods of analysis of the scans of 38 normal humans and 60 patients suspected to have pneumoconiosis. Results of previous investigations on the mechanisms of 67Ga uptake in interstitial lung disease are reviewed. These data strengthen the view that quantitative 67Ga lung scan has become a standard technique to assess inflammatory activity in the interstitial lung diseases and that computer-based method of analysis of the scan provides an index of inflammatory activity of the lung disease that correlates with lung lavage and biopsy indices of inflammation in the lung tissue.
Asbestosis↗
Gallium-67 uptake in the lung of asbestos exposed sheep: early association with enhanced macrophage-derived fibronectin accumulation.
To evaluate the time course and mechanisms of enhanced 67Ga lung uptake in asbestosis, we exposed two groups of sheep every 2 wk to either 100 ml saline (controls) or 100 mg UICC chrysotile fibers in 100 ml saline. The sheep were evaluated periodically by pulmonary function tests (PFT), thoracic radiograph (TR), 67Ga lung scan bronchoalveolar lavage (BAL), and transbronchial lung biopsy (TLB). By month 24 of the study, 9/15 exposed sheep had developed the initial alveolitis and had significant changes in PFT, TR, and TLB. The other six exposed sheep differed from controls only by a 75% increase in BAL fibronectin until month 30, where significant changes in albumin occurred and 67Ga scan score increased. The nine sheep with alveolitis had significant sustained increases in 67Ga scan and BAL levels from month 6, associated with a 150% increase in BAL fibronectin and other parameters of disease activity changed from month 18 to 30. We concluded that in the sheep model of asbestosis, significant changes in 67Ga scan, 67Ga BAL counts, and excessive elevation of BAL fibronectin preceded other parameters of disease activity. The data suggest that excessively activated macrophages are primarily responsible for the early 67Ga lung uptake.
Animals↗
[The museum of nuclear medicine in the year 2025].
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Humans↗
Ascites and right pleural effusion: demonstration of a peritoneo-pleural communication.
A 54-yr-old female with known liver cirrhosis presented with a right transudative pleural effusion and ascites. To find the source of pleural fluid, [99mTc]sulfur colloid was injected intraperitoneally and a serial imaging study revealed its passage to the right pleural space on 2-hr and 24-hr images. Mechanisms proposed in the formation of pleural effusion in liver cirrhosis are (a) lymphatic drainage and (b) diaphragmatic defect. Radioisotope migration speed may be a clue for differentiating these two mechanisms, being more rapid in the presence of a diaphragmatic defect.
Ascites↗
Clinical features to stage alveolitis in asbestos workers.
To analyze the clinical features of asbestos-induced alveolitis and stage its activity, we evaluated 217 asbestos workers by the usual clinical, radiological, and functional parameters and computerized gallium 67(Ga) lung scan; we obtained bronchoalveolar lavage (BAL) in 33 and lung biopsy in 6. In addition, we scored the profusion of lung rales and correlated it with other parameters of severity of asbestosis. In the 55 workers without asbestosis and normal 67Ga scan, BAL analyses were comparable to those of controls. Of the 56 without asbestosis but increased 67Ga lung uptake, BAL analyses in 8 documented a predominantly macrophagic alveolitis (confirmed on lung biopsy in 3), with the highest levels of BAL fibronectin. In the 106 workers with asbestosis, 67Ga lung uptake was increased in 75; BAL in 17 demonstrated a macrophagic and neutrophilic alveolitis with elevated fibronectin levels. Lung biopsy in 3 of the latter workers documented peribronchiolar fibrosing alveolitis. Rale scores in all workers or in those without asbestosis did not correlate with 67Ga scores; they correlated fairly well with profusion of parenchymal opacities (Rs = 0.42) and rigidity of the lung pressure-volume curve (Rs = 0.39). Thus, 67Ga lung uptake is an early indicator of chronic macrophagic alveolitis in asbestos workers, which usually progresses to asbestosis. In the disease, profusion of lung rales constitutes a simple clinical mode of assessment of disease severity that correlates better with radiological and functional parameters than with parameters of alveolitis.
Adult↗
Gallium-67 thoracic scan and pleural disease in asbestos workers.
We have recently reported that 67Ga scanning in asbestos workers can document excessive uptake of the marker among workers without sufficient criteria for asbestosis, but in our initial report we could not exclude definitely that 67Ga uptake could be related to pleural disease. To further test this hypothesis, we analyzed the 67Ga thoracic scan in relation to profusion scores of pleural disease on chest roentgenogram and CT scan of the thorax in 171 asbestos workers. We found no significant correlation between the 67Ga lung uptake and the radiographic scores of pleural disease. We concluded that pleural plaques are not an active site of 67Ga accumulation and do not contribute significantly to the thoracic uptake of the marker.
Adult↗