The resolution of mixtures of viable mammalian cells into homogeneous fractions by zonal centrifugation.

Large-scale separation of mixtures of mammalian cells was obtained with the A-1X zonal centrifuge rotor and density gradients consisting of Ficoll dissolved in modified Eagle's MEM suspension-culture medium. The cells remained viable as tested by plating efficiency or by motility observed with time-lapse photography. Rabbit thymocyte and HeLa cell mixtures were separated with 99 and 89 per cent purity, respectively. Mixtures of thymocytes and suspension-cultured, human acute leukemia cells (Roswell Park strain LKID) were separated with 93 and 91% purity, respectively. HeLa cells were isolated 92% pure from a mixture with horse leukocytes. A book of charts giving the sedimentation position and velocity versus time of cells in the A rotor under standard conditions of gradient composition, angular velocity, and temperature was prepared with the use of a computer program based on the differential sedimentation equation. The charts are used to estimate the centrifugation time necessary for maximum separation of cells. The success achieved in separating mixtures of cells points to the future possibility of large-scale fractionation of solid tissues, especially tumor tissues, into preparations cf viable cells of a single type.

Computed tomography of the normal pericardium.

Computed tomographic (CT) scans of 100 patients were reviewed to establish the normal thickness of the pericardium. The pericardium was identified in 95 of 100 patients. The mean width of the thinnest portion of the pericardium was 2.0 +/- 0.6 mm (1 SD) in males (N = 46) and 2.3 +/- 0.5 mm (1 SD) in females (N = 49). The mean width of the combined series was 2.2 +/- 0.6 mm (N = 95). In none of the 95 hearts reviewed was the width of the thinnest portion of the pericardium greater than 4 mm. Focal changes in width of the pericardium were a normal finding in patients without documented pericardial disease.

Sequential feline esophageal nutrient blood flow: perfusion measurements in vivo.

The utilization of a catheter semiconductor beta detector (CASRAD) to perform in vivo, sequential, esophageal nutrient blood flow distribution studies in cats is described. A diffusable radioisotope, Rubidium 86 (86Rb), was injected intravenously and the CASRAD placed within the esophageal lumen. The distribution of 86Rb remained stable within the feline esophagus for sufficient time to allow for counting at 1.5 cm levels in the esophagus. The accuracy limitations of the CASRAD system were assessed by comparing the in vivo, recorded distribution of 86Rb with the esophageal distribution of 86Rb as determined by a well-type scintillation counter. The distribution throughout most of the esophagus was similar by both techniques. Sequential esophageal studies performed with the CASRAD showed less variability than existed in the biological differences between cats and the methodology of obtaining and counting tissue by well-type scintillation counter (mean coefficient of variation 11.6% versus coefficient of variation 23.1%).

Diameter of arterial microvessels trapping 8--10 micron, 15 micron and 25 micron microspheres as determined by vital microscopy of the hamster cheek pouch.

An assumption inherent in the use of microsphere methodology for measuring regional blood flow is that microspheres are removed from the circulation by impacting in arterial vessels of approximately their own diameter. We investigated the in vivo relationship between the diameter of varying size microspheres and the calibre of trapping microvessels within the hamster cheek pouch. Intracardiac injection of 8-10, 15 +/- 5, 25 +/- 5 micron carbonized microspheres with diversion of the cardiac output into the bracheocephalic trunk provided direct, in vivo visualization of the impaction sites of these various size microspheres within the cheek pouch microvasculature. Fifteen micron microspheres usually impacted at the orifice or neck of small arterioles and protruded into the lumen of the parent vessel. Eight to ten micron microspheres lodged in vessels with a mean diameter of 11.5 +/- SD 3.4 micron indicating that they usually impacted primarily in terminal arterioles.

Tumefactive extramedullary hematopoiesis of the stomach.

A 3 X 4 cm submucosal gastric mass of extramedullary hematopoeitic tissue occurred in a patient with chronic myelogenous leukemia. Such stomach masses have been misinterpreted as malignant tumor. Tumefactive extramedullary hematopoiesis of the stomach is an infrequent occurrence in patients with extramedullary hematopoiesis but should be considered in the differential diagnosis of patients known to have this condition.

Secondary esophageal tumors.

Secondary esophageal carcinoma usually originates from a primary site in either the lung or breast and produces obstruction and symptoms that frequently mimic a benign esophageal stricture or primary esophageal carcinoma. Esophagoscopy shows a smooth identation, usually covered with normal mucosa; the appearance resembles a benign esophageal stricture. Esophageal biopsy in patients with secondary tumors is often negative for carcinoma. The radiologist plays a significant diagnostic role by his ability to show that the cause of the stricture is extramucosal and may be due to a secondary carcinoma involving the esophagus.

Computed tomography of the abnormal pericardium.

Computed tomographic (CT) findings in 18 patients with documented pericardial disease are reported. The pericardium appears as a thin, curvilinear, 1- to 2-mm-thick density best seen anterior to the right ventricular part of the heart. Pericardial abnormalities detected by CT include effusions, thickening, calcification, and cystic and solid masses. Computed tomography is complimentary to echocardiography in its ability to more accurately characterize pericardial effusions, masses, and pericardial thickening.

Multiple "bull's-eye" lesions in gastric lymphoma.

Three adolescent patients with multiple gastric target lesions and gastric lymphoma are reported. Each had either histiocytic or poorly differentiated lymphoma. The literature was reviewed to ascertain whether multiple gastric lymphomatous target lesions were confined to adolescent patients or to patients with a particular histologic subtype. Review of 119 cases in the literature did not support either hypothesis.

Non-beta islet cell tumor calcification assoicated with Zollinger-Ellison syndrome and multiple endocrine adenomatosis.

The radiographic triad of a calcified pancreatic mass, duodenal ulcers, and nephrocalcinosis should suggest the Zollinger-Ellison syndrome, as part of the multiple endocrine adenomatosis complex. The clinical and radiographic features of the entity are described in this case report.

Profile roentgenographic features of benign greater curvature ulcers.

Certain roentgenographic features have been considered typical of benign gastric ulcers, based almost entirely on studies of the lesser curvature. However, these features frequently are not present on the profile view in benign greater curvature ulcers. Moreover, features stated to suggest malignancy in gastric ulcers are commonly simulated by benign greater curvature ulcers. The authors reviewed the profile roentgenographic features of 19 benign greater curvature ulcers and found that they often appeared to be intraluminal and had shouldered edges due to spasm of the surrounding circular muscles. In 6 patients the adjacent gastric contour was scalloped. These features frequently cause radiologists to misinterpret benign greater curvature ulcers as malignant.