Biomedical subjects
Publications and source records attributed to D S Mendelson.
Nineteen patients with infectious spondylitis were evaluated by computed tomography (CT) and the results were compared with conventional radiography. In each case the diagnosis was established by biopsy. The use of CT in evaluation of the extent of bone and soft tissue involvement as well as its role in differentiating inflammatory from noninflammatory destructive processes is discussed.
Nine patients with malignant external otitis (MEO) were evaluated with Tc-99m bone scans, Ga-67 citrate scans, pluridirectional tomography, and computed tomographic (CT) scans in order to assess the role of each in the diagnosis and management of MEO. The Tc-99m and Ga-67 citrate scans were the most accurate studies in the initial identification of disease activity, while the return to normal or improvement of the Ga-67 citrate scan has been shown to correlate best with clinical resolution of MEO. CT demonstrated soft-tissue disease and central skull base osteomyelitis better than pluridirectional tomography. CT is excellent for localizing and following the progression of bone disease; however, because reossification of the skull base is a very slow process, CT cannot be used to follow accurately regression or inactivity of MEO affecting this area. CT is the best modality for following soft-tissue extension of MEO.
Four patients with mediastinal masses are described. CT examinations demonstrated masses of high attenuation, and solid masses were suspected. At thoracotomy each patient had a cystic mass containing a brownish, turbid, mucoid material. The pathologic diagnosis in each case was a bronchogenic cyst. The possibility of such a cyst should not be excluded because of a high CT number, which reflects the turbid contents of the cyst.
Amiodarone (Cordarone) is an iodinated cardiac antiarrhythmic drug that causes a slate-gray discoloration of the sun-exposed skin and a yellow-brown stippling of the cornea. Histopathologically, biopsy specimens of aminodarone pigmentation sites disclose yellow-brown refractile granules in the reticular dermis. These granules were characterized by transmission electron microscopy as being concentrically arranged intralysosomal inclusions ("myelinlike" bodies) in dermal endothelial cells and perivascular smooth-muscle cells. Electron probe x-ray analysis of these same inclusions disclosed definite peaks for iodine, evidence for the presence of amiodarone or a metabolite of the drug at these sites. Amiodarone, then, concentrates in lysosomes and causes an accumulation of lipids similar to what has been seen with other cationic amphiphilic compounds, such as the glycosphingolipid stored in Fabry's disease. Amiodarone must be recognized as a cause of a drug-induced lipid storage disease with cutaneous and corneal manifestations.
A patient with sarcoidosis is presented, in whom computed tomography demonstrated significant compression of the bronchi by surrounding lymphadenopathy.
Splenosis is an unusual complication of splenic trauma. The computed tomographic (CT) appearance of splenosis is described. One should consider this diagnosis when faced with a history of splenic trauma and multiple round or oval masses at CT.
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A lobar perfusion defect in the presence of a normal arterial phase in the pulmonary angiogram may be due to stasis secondary to compression of a pulmonary vein by a hilar or perihilar mass. In this report we present a patient with metastasis to the right lung and hilum by malignant melanoma. A lobar perfusion defect was present in an area of lung tht appeared normal by radiograph. This defect was shown to be due to stagnating blood flow reflected by delayed intense capillary phase in that lobe and late opacification of the corresponding draining vein.
It has been established that granulocytes generate superoxide (O-2) as well as hydrogen peroxide (H2O2) during phagocytosis. The chemiluminescence (CL) generated by phagocytes appears dependent on these oxygen radicals (or). however, recent studies suggest that oxygen molecules, including singlet oxygen (1O2) or hydroxyl radicals (OH-), may also be generated during phagocytosis and contribute to CL. We have tested this possibility by studying human granulocyte CL in the presence of 0.1 mM sodium azide, a known inhibitor of myeloperoxidase and catalase and a scavenger of 1O2. The effects of azide on CL were correlated with the effects of this compound on hexose monophosphate shunt (hmps) activity, nitroblue tetrazolium (NBT) dye reduction, formate oxidation, and cytochrome c reduction. CL generated by granulocytes during the phagocytosis of zymosan particles was markedly impaired by azide (24% to 47% of control values). On the other hand, phenomena dependent in part on the presence of O2 radicals, i.e., reduction of NBT dye and cytochrome c, were not impaired by the presence of azide. As would be expected, inhibition of catalase by azide virtually abolished the oxidation of formate, but the burst in HMPS activity associated with phagocytosis was augmented further. The latter observation indicated that azide did not impair generation of H2O2 but increased the relative amount detoxified via the HMPS. The experiment provides evidence that radicals other than O-2 and H2O2 are generated during phagocytosis and that these radicals are major contributors to the CL phenomenon.
The role of reduced glutathione in relation to hexose monophosphate shunt activity and peroxide detoxification has been well established in human erythrocytes. Less is known about the content of reduced glutathione in phagocytic leukocytes and the changes that occur during functional activity. We have measured the reduced sulfhydryl content of normal resting human granulocytes and of cells isolated from a patient with chronic granulomatous disease. Normal cells and those from the patient with chronic granulomatous disease contained similar concentrations of reduced sulfhydryls. Stimulation of a phagocytic response by incubation with opsonized zymosan particles resulted in prompt and nearly complete depletion of intracellular glutathione from normal granulocytes. This fall in reduced glutathione concentration was dependent on the phagocytic load. Exposure of chronic granulomatous disease granulocytes to a similar phagocytic load resulted in a slower and less complete fall in reduced glutathione. In normal cells, those from the chronic granulomatous disease patient, and those from an obligate carrier of the disease, the decrement in reduced glutathione during phagocytosis was correlated with oxidation of 14C-1-glucose and 14C-formate, nitroblue tetrazolium reduction, and the chemiluminescence phenomenon.
A 74-year-old woman with secondary erythrocytosis was found to have Howell-Jolly bodies in peripheral blood erythrocytes following acute splenic infarction. The Howell-Jolly bodies were a transitory finding and disappeared six days after the infarction, although the spleen remained abnormal by isotope scanning for several weeks. Careful inspection of the peripheral blood film may be an aid in the diagnosis of acute splenic infarction.
Two cases of giant varices in portal hypertension are presented. Dynamic computed tomography (CT) was useful in establishing that the masses were in fact dilated veins.
Thirteen patients' status post repair of thoracic aortic dissection were studied with both magnetic resonance and angiography. MRI was an accurate modality in identifying residual dissection when aortography was used as the gold standard. MRI can be used as a noninvasive modality for the follow-up of these patients.
Carcinoid tumors of the lung typically arise centrally within the tracheobronchial tree. We report a rare case of a carcinoid tumor presenting as a pleural mass. The classification and X-ray features are described.
Previously unreported, we note the complication of anterior shoulder subluxation that occurred secondary to patient positioning during chest CT examination. Positioning a patient's arms abducted and externally rotated over the head can precipitate anterior shoulder subluxation in patients with anterior shoulder instability.
The CT findings in 16 patients (20 examinations) with proven localized fibrous mesothelioma are described. These lesions proved to be large, uninvasive, sometimes heterogeneous, and enhancing solitary masses. These morphologic findings in an asymptomatic patient should be suggestive of this lesion.
Germ cell tumors (GCT) arising in the testes secondarily involve bowel in 5% of patients (1), and such involvement is usually via extension from adjacent metastatic lymphadenopathy. While this involvement often causes obstruction and gastrointestinal bleeding, radiologic identification of bowel ulceration has not been reported. We report an unusual case of small bowel invasion and ulceration, identified on CT examination, due to adenopathy resulting from testicular carcinoma.