Small arteries in peripheral lymph nodes: a specific US sign of lymphomatous involvement

Fifty-seven patients with palpably enlarged peripheral lymph nodes underwent detailed ultrasonographic (US) examination with a 5.0-MHz and a 7.5-MHz probe. In 32 of 36 patients with malignant lymphoma (12 with Hodgkin disease, 24 with non-Hodgkin lymphoma) US showed a hypoechoic mass with a centrally located tubular structure. Pathologic examination showed that this structure correlated with small intact arterial vessels encased by confluent lymphomatous masses. This sonographic finding was not seen in patients with carcinomatous metastatic lesions to the lymph nodes (nine patients) or benign lymphadenitis (12 patients). The detection with US of small arteries within enlarged lymph nodes may indicate nodal infiltration by malignant lymphoma.     

Peripheral cholangiocarcinoma and clonorchiasis: CT findings

Sixteen patients with peripheral cholangiocarcinoma of the liver were examined with computed tomography (CT). None of the 16 patients presented with jaundice or had documented cirrhosis. On scans obtained both before and after the injection of contrast material, the tumors were depicted as low-attenuation masses in all cases, with wide variations in homogeneity. The tumor margin was irregular in 12 cases, and there was minimal contrast enhancement of the tumor in 14 cases. In 11 (69%) patients, CT demonstrated masses of markedly low attenuation, which corresponded to areas of diffuse microcystic change seen at histologic examination of resected specimens. In ten (63%) patients, the results of stool or intradermal tests for Clonorchis sinensis were positive. In all ten cases of clonorchiasis, mild, diffuse dilatation of the intrahepatic bile ducts was seen in addition to the low-attenuation masses, but there was no dilatation of the extrahepatic biliary tree. In five of the ten patients with clonorchiasis, stippled or aggregated, powderlike areas of high attenuation were seen on precontrast CT scans; at pathologic examination, those areas were found to be mucin. Extrahepatic metastases were demonstrated in ten (63%) patients. Peripheral cholangiocarcinoma should be the primary diagnostic consideration when these characteristic CT findings are detected in a noncirrhotic patient.     

Hepatic micrometastases in the rat: ferrite-enhanced MR imaging

A rat tumor model was used to evaluate the ability of ferrite-enhanced magnetic resonance (MR) imaging to demonstrate hepatic metastases smaller than 1 cm. Twenty-eight rat livers were inoculated with 5 X 10(5) mammary carcinoma cells and imaged with a 0.6-T MR system. Non-enhanced and ferrite-enhanced images were analyzed and correlated with autopsy findings for each rat. Lesion detection rates correlated closely with cancer-to-liver contrast-to-noise ratios. Ferrite-enhanced MR imaging demonstrated significantly more lesions than non-enhanced imaging (P less than .05) and decreased the threshold size for lesion detectability (less than 2 mm). Ferrite also enabled more accurate measurements of the lesions (r = .96).     

Neutrophils adherent to a nonphagocytosable surface (glomerular basement membrane) produce oxidants only at the site of attachment

Adherence of neutrophils to glomerular basement membrane containing immunoglobulin G aggregates was accompanied by a marked increase in oxygen uptake (eightfold). Very little of the O2 consumed was recovered as superoxide, measured by cytochrome c reduction, or as H2O2, measured with horseradish peroxidase and scopoletin. When neutrophils were incubated with the basement membrane preparation in the presence of cerium chloride to detect H2O2, electron micrographs showed cerium perhydroxide deposits in the contact area between the cells and the basement membrane, but not on the remainder of the cell surface. The results imply that superoxide is produced only where the plasma membrane is in contact with the basement membrane matrix, and that it mostly breaks down to H2O2 or undergoes other reactions at this site. The longer lifetime of H2O2 compared with that of superoxide allows some of the H2O2 produced to be detected in the medium. The results also suggest that the area of contact between the neutrophil and surfaces such as basement membrane is inaccessible to proteins in the medium, eg, cytochrome c. Circulating scavengers such as superoxide dismutase or catalase, or proteolytic inhibitors, may therefore be unable to control events occurring at this site.     

Captopril once daily in patients with essential hypertension and hyperuricaemia

Captopril (Capoten; Squibb) 100 mg was given as once-daily monotherapy in 20 patients with hypertension and hyperuricaemia. Ten patients (group A) maintained a low-sodium diet (60-100 mmol/d) throughout the study and 10 (group B) continued their usual high-sodium (200-300 mmol/d) diet. After 4 weeks of active treatment supine blood pressure in group A decreased from 192 +/- 5/119 +/- 3 mmHg to 144 +/- 3/95 +/- 3 mmHg (P less than 0,001), whereas pressures in group B varied between 168 +/- 5/115 +/- 3 mmHg and 160 +/- 6/113 +/- 4 mmHg (not significant). Serum urate values fell from 0,46 +/- 0,02 mmol/l to 0,35 +/- 0,02 mmol/l (P less than 0,001) and 0,53 +/- 0,02 mmol/l to 0,46 +/- 0,03 mmol/l (P less than 0,05) in the same groups. Captopril exerted an antihypertensive effect in patients receiving a low-sodium diet, suggesting a relationship with angiotensin II and/or aldosterone; effects on serum urate levels appeared to be independent of diet.     

Selective flow cytometric sorting of viable dopamine neurons

Flow cytometry has been revealed as a powerful technique for studying cell populations. The availability of the method to identify, analyze and isolate specific populations of central nervous system cells will be of great aid for studying the in vivo (i.e. neural transplants) and in vitro (i.e. cell cultures) behavior of these cells. The present report describes the analysis and cell sorting of a population of retrogradely fluorescence-labeled dopamine-containing neurons from ventral mesencephalon. Dopamine neurons were identified by immunohistochemical localization of neuron-specific enolase and tyrosine hydroxylase. After being maintained in culture, this relatively pure population differentiates toward a mature phenotype bearing a prominent neuropil.     

Rhinocerebral mucormycosis: A case report with magnetic resonance imaging findings

Mucormycosis is a rare fungal disease most often encountered in patients who are diabetic, immunocompromised, severely burned, orwho have a history of intravenous drug abuse. Intracranial presentation includes the isolated cerebral and the more common rhinocerebral forms. The computed tomography picture in mucormycosis is well documented. The magnetic resonance (MR) findings associated with mucormycosis have not been previously described. We report a case of rhinocerebral mucormycosis in a poorly controlled diabetic man where the MR findings of cavernous sinus thrombosis and thrombosis of the cavernous portion of the internal carotid artery demonstrated progression of the patient's disease in spite of his stable clinical course. The results of the MR findings directly altered the patient's therapy, thus leading to a favorable outcome.     

Primary tumors of the patella

This study reports 42 cases of histologically proven and radiographically correlated primary patellar tumors. Despite diverse histologic diagnoses, the radiographic appearances of benign as opposed to malignant patellar neoplasms are essentially indistinguishable. Although the literature suggests that giant cell tumor is the most frequent benign tumor of the patella, the most common benign neoplasm in this series is chondroblastoma (16 cases). Only four primary malignant lesions were encountered, three cases of lymphoma and one case of hemangioendothelioma. Since 38 (90%) of the 42 cases were benign, a benign etiology should be strongly favored, notwithstanding the radiographic appearance, whenever a primary patellar tumor is encountered.The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the Department of the Army or the Department of Defense.