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Biomedical subjects

E Levine

Publications and source records attributed to E Levine.

At least 127 records · Page 7Linked to original sources
PubMed1986

MR imaging and CT of extrahepatic cavernous hemangiomas.

Ten extrahepatic cavernous hemangiomas in seven patients were evaluated by MR and CT. MR was done with a 1.0-T superconducting magnet and spin-echo imaging. The lesions occurred in the musculoskeletal system, parotid gland, and spleen. MR and CT features of hemangiomas were compared, and MR findings in hemangiomas were also compared with those in eight musculoskeletal tumors of nonvascular origin. MR detected 10 hemangiomas, while nine were shown by CT. Also, MR was more accurate than CT in three patients in determining the true extent of hemangiomas. At a pulse-repetition interval of 2000 msec and an echo delay time of 90 msec, all hemangiomas were markedly hyperintense compared with skeletal muscle. Quantitatively, at this pulse sequence, intensity ratios of hemangiomas to skeletal muscle were all seven or greater (mean = 9.89), while the ratios for other tumors were usually less than seven (mean = 5.14). These means differed significantly (p less than .001). Small cavernous hemangiomas were homogeneous, well-defined round or oval lesions, while large hemangiomas consisted of dilated, tortuous vascular channels. Other tumors, however, were usually heterogeneous owing to hemorrhage and necrosis and had irregular margins. MR may, therefore, be useful for distinguishing cavernous hemangiomas from other soft-tissue tumors, particularly sarcomas.

Adolescent↗
PubMed1985

Juxtacortical osteosarcoma: a radiologic and histologic spectrum.

Radiologic and pathologic findings were analyzed in four patients with parosteal osteosarcomas, three with periosteal osteosarcomas and one with a high-grade surface osteosarcoma. Plain film and histologic findings considered together are usually distinctive and permit differentiation of these tumors from each other and from other lesions with which they are frequently confused. Prognosis and management are determined by tumor extent and histologic grade. Computed tomography is more accurate than conventional tomography, angiography, and bone scintigraphy for preoperative determination of tumor extent and for assessing tumor relationships to the bone cortex and medullary cavity. Histologically, parosteal osteosarcomas are usually low-grade, while periosteal and high-grade surface osteosarcomas are generally high-grade tumors and have worse prognoses. High-grade surface osteosarcoma, which is indistinguishable in behavior and histology from classical medullary osteosarcoma, requires more aggressive surgical management than parosteal and periosteal osteosarcomas.

Adolescent↗
PubMed1985

Endothelialization of human collagen surfaces with human adult endothelial cells.

Artificial vascular grafts are currently used to restore blood flow to ischemic tissue. Although the long-term patency of large diameter grafts is relatively acceptable, small diameter (less than 4 mm) grafts exhibit poor long-term patency rates. One technique to create a nonthrombogenic surface on artificial prostheses has been to seed with endothelial cells derived from autologous vessels. We have examined the interaction of human adult endothelial cells with the natural collagen surfaces presented by human amnion. Scanning electron microscopic evaluation revealed that human adult endothelial cells adhered rapidly to both the basement surface (collagen types IV and V) and interstitial surface (collagen types I and III) of amnion. However, the adherence of cells was significantly greater on the basement membrane surface. In addition, human adult endothelial cells rapidly formed close cell-to-cell interactions on basement membrane as compared with cells seeded onto the interstitial surface. These results suggest that seeding of endothelial cells onto artificial surfaces will be facilitated if the surface simulates the natural basement membrane to which endothelial cells natively adhere.

Adult↗
PubMed1985

Adult human endothelial cell compatibility with prosthetic graft material.

We have developed a system for the in vitro evaluation of the interaction of human adult endothelial cells (HAEC) with prosthetic vascular graft material. HAEC, isolated from adult human iliac veins, proliferated vigorously in culture for approximately 70 population doublings. The large number of HAECs produced permitted high-density seeding of prosthetic grafts. Samples of prosthetic material were immobilized on a plastic ring and were used either untreated or coated with extracellular matrix, fibronectin, or plasma. HAEC were seeded at high density and adherence was evaluated by light and electron microscopy after a 2-hr incubation. While essentially no HAEC adhered to untreated grafts, treatment of grafts with either extracellular matrix, plasma, or fibronectin resulted in dramatic adherence of HAEC. The highest density of HAEC adherence was observed on collagen-coated Dacron grafts, and was equal to the cell density observed in confluent monolayers of HAEC grown on gelatin-coated tissue culture plastic. This study demonstrates a method capable of determining HAEC-graft biocompatibility prior to the use of an in vivo system.

Adult↗
PubMed1985

High-density renal cysts in autosomal dominant polycystic kidney disease demonstrated by CT.

Unenhanced abdominal CT scans of 35 patients with autosomal dominant polycystic kidney disease (ADPKD) showed multiple high-density (58-84 HU) renal cysts in 42.9% of patients, occasional high-density cysts in 25.7%, and no high-density cysts in 31.4%. These high-density cysts were usually subcapsular and were more frequent in patients with markedly enlarged kidneys and flank pain at the time of CT. Several were found to contain altered blood on pathological analysis. Follow-up CT often showed a reduction in cyst densities, although some cysts developed mural calcification and calcification of their contents. High-density cysts are probably produced by cyst hemorrhage. This may occur randomly as part of the natural history of the disease or may result from minor trauma to the enlarged kidneys. Renal carcinomas occur rarely in ADPKD and may occasionally be hyperdense. However, high-density cysts may usually be distinguished from carcinomas on CT by their smooth contours, sharp interfaces with renal parenchyma, homogeneity, and lack of contrast enhancement.

Adult↗
PubMed1985

Tumor involvement of peripheral joints other than the knee: arthrographic evaluation.

Arthrography was performed in 24 patients with tumors in the region of the shoulder, elbow, wrist, hip, and ankle. Conventional arthrograms were supplemented by arthrotomograms and/or computed arthrotomograms as necessary. The presence or absence of joint involvement by tumor was correctly identified in 22 of 24 patients (91.7%). It is concluded that arthrography is a reliable method for detecting joint involvement by tumor, and should be performed if plain radiography, conventional tomography, and computed tomography are not definitive in demonstrating joint involvement.

Adolescent↗
PubMed1985

A monoclonal antibody to human platelet glycoprotein IIIa detects a related protein in cultured human endothelial cells.

We have previously described a series of monoclonal antibodies against platelet membrane glycoproteins. Two of the antibodies, B59.2 and B2.12, recognize the glycoprotein IIb-IIIa complex. These two antibodies react specifically with glycoprotein (GP) IIIa, as shown by immunoblotting of sodium dodecyl sulfate-polyacrylamide gels of solubilized platelet membranes. Monoclonal B2.12, but not B59.2, binds to cultured human endothelial cells obtained from umbilical vein, internal iliac artery, and inferior vena cava. At saturation approximately 100,000 binding sites were detected per human umbilical vein endothelial cell. When solubilized radioiodinated cells were chromatographed on a column of agarose-bound B2.12, a single radiolabeled protein was obtained whose apparent molecular weight is slightly larger than that of platelet GP IIIa. This protein incorporated [35S]methionine when endothelial cells were labeled metabolically. These results demonstrate that human endothelial cell membranes synthesize a protein immunologically related to platelet GP IIIa.

Antibodies, Monoclonal↗
PubMed1985

Liver cysts in autosomal-dominant polycystic kidney disease: clinical and computed tomographic study.

Hepatic CT findings were analyzed in 44 patients with autosomal-dominant polycystic kidney disease and were correlated with liver and renal function tests and liver, splenic, and renal CT volume measurements. CT showed many large liver cysts in 31.8% of patients, small liver cysts in 25%, and no liver cysts in 43.2%. Patients with many large cysts often showed increased liver volumes. Splenic volumes did not differ significantly in patients with and without liver cysts, suggesting that portal hypertension is rarely associated with cystic liver disease. There was no correlation between severity of liver involvement and extent of renal cystic disease as determined from urea nitrogen and creatinine levels and renal volumes. Liver function tests were normal except in two patients, one with a cholangiocarcinoma, which may have arisen from a cyst, and the other with an infected liver cyst and chronic active hepatitis. Accordingly, if liver function tests are abnormal, an attempt should be made to identify complications of polycystic liver disease such as tumor, cyst infection, and biliary obstruction. Such complications are rare but may be seen in patients whose lives are prolonged by dialysis and renal transplantation. CT is a useful method for detecting liver cysts and identifying patients at risk for these complications.

Adult↗
PubMed1985

Computed tomography of renal masses.

Computed tomography (CT) has provided a valuable imaging modality for the study of renal masses. Simple cysts are the most common of renal masses, and they are usually readily differentiated by CT from the wide variety of solid tumors that affect the kidneys. This article describes the CT technique which is used for evaluation of renal masses; the CT appearances of such renal tumors as renal cell carcinoma, renal pelvic carcinoma, lymphoma, oncocytoma, and angiomyolipoma and the use of CT in the staging of malignant renal tumors. The CT findings in various renal cystic diseases are also described. The role of CT for evaluating renal masses in relation to such other imaging techniques as sonography and angiography is discussed.

Adenoma↗
PubMed1984

Role of radiologic imaging in management planning of giant cell tumor of bone.

The radiologic studies of 24 patients with giant cell tumors were evaluated with respect to their ability to determine tumor extent and to influence management. Computed tomography (CT) was the most accurate method for detecting soft tissue tumor extension, and conventional tomography was the best technique for evaluating penetration of subarticular cortical bone. Detection of these findings led to performance of en bloc tumor resection rather than curettage and grafting in patients with lower extremity tumors. Arthrotomography was helpful in some instances in detecting cartilage and joint invasion by tumor, joint invasion being an indication for extra-articular rather than transarticular tumor resection. Scintigraphy was not as accurate as conventional tomography or CT in determining intraosseous tumor extent because of increased tracer uptake beyond the true tumor limits in several cases. Angiography has been largely replaced by CT in evaluating giant cell tumors.

Adolescent↗
PubMed1984

Human adult endothelial cell growth in culture.

The purpose of the present study was to culture human adult endothelial cells (HAECs) on a long-term basis in the laboratory. Previous inability to accomplish this has been the major impediment to the in vitro study of endothelialization of prosthetic grafts with human cells, a problem of significant clinical relevance. We have been successful in developing a technique that allows HAECs from human adult arteries, veins, and capillaries to proliferate vigorously in culture for up to 80 population doublings. HAECs are grown on a gelatin surface (medium 199 containing 20% fetal calf serum). Heparin and endothelial cell growth factor (ECGF) are required for optimal growth. With this technique, which will be described in detail, over 10(23) HAECs can be produced from each 1 cm2 of vascular tissue. This makes large numbers of HAECs available for high-density seeding on prosthetic grafts prior to implantation. It also permits for the first time with human cells the in vitro study of prosthetic grafts--HAEC interactions and the factors that enhance optimal growth and adherence to prosthetic materials. It is hoped that identification of the factors promoting graft endothelialization in combination with high-density seeding will lower graft thrombogenicity and therefore result in greater graft longevity than has been possible heretofore.

Adult↗
PubMed1984

Computer graphics for digitally formatted images.

The increasing use of digitally formatted imaging systems requires high-quality interactive gray-scale computer raster graphics systems for the management, display, and analog film recording of digital image and alphanumeric information. These systems are a combination of computer hardware and software and implement a set of graphics protocols. This paper describes a set of interactive graphics protocols that has been developed for clinical use.

Computers↗
PubMed1984

CT of acquired cystic kidney disease and renal tumors in long-term dialysis patients.

The kidneys of long-term dialysis patients frequently demonstrate multiple small acquired cysts and renal cell tumors on pathologic examination. The original kidneys of 30 long-term dialysis patients and six renal transplant patients were evaluated by computed tomography to determine the incidence of these abnormalities. Among dialysis patients, 43.3% had diffuse bilateral cysts, while 16.7% had occasional cysts (fewer than five per kidney), and 40% showed no renal cysts. Seven solid renal tumors were detected in four dialysis patients with renal cysts. Acquired cystic kidney disease tends to result in renal enlargement, is more common in patients who have been maintained on dialysis for prolonged periods, and may lead to spontaneous renal hemorrhage. The six transplant patients showed no evidence of renal cysts, and all had markedly shrunken kidneys. Acquired cystic disease and renal cell tumors in the original kidneys of dialysis patients may be due to biologically active substances that are not cleared effectively by dialysis but that are removed by normally functioning transplant kidneys.

Adult↗