PubMed Health⌕ Search

Biomedical subjects

J C Hoffman

Publications and source records attributed to J C Hoffman.

At least 55 records · Page 3Linked to original sources
PubMed1983

Work in progress. Intra-arterial digital subtraction angiography: evaluation in 150 patients.

As part of an ongoing study comparing digital subtraction angiography (DSA) with conventional film-screen angiography, 150 patients were examined with arterial contrast material injections and digital filming techniques alone or combined with conventional angiography. Of 247 injections, the DSA study was good or excellent in 236, approaching the quality of conventional angiography for visualization of vessels greater than 1 mm in size. Advantages included improved vascular detail in selected areas such as the skull base, visualization of minimal contrast concentration in diseased vessels or postoperatively, and imaging of vessels distal to stenoses without the hazards of selective catheterization. DSA permitted rapid positioning under fluoroscopic control, instantaneous viewing of subtracted images, and reduced technologist time and film costs. Contrast material volume was reduced by 40 to 60%, allowing multiple studies in one sitting and study of patients with renal compromise.

Angiography↗
PubMed1983

Clinical indications for computer-assisted myelography.

Computer-assisted myelography (CAM) is a technique in which computed tomography (CT) is combined with the intrathecal administration of metrizamide to demonstrate the spinal cord and surrounding structures. This retrospective study of 139 CAMs performed at Emory University Hospital included 125 CAMs that were preceded by routine metrizamide myelography (secondary CAM). The remaining 14 CAMs were primary studies without concomitant myelography. These CAMs and conventional myelograms were reviewed to provide indications for the use of CAM as a replacement for other radiodiagnostic studies or as an adjunct to radiological diagnosis. Eighty-one CAMs (58%) were positive for some pathological process. Of the 69 secondary CAMs demonstrating a pathological condition, 46 (67%) revealed some aspect of the lesion not apparent on routine metrizamide myelography. In no case with positive myelography was CAM negative. However, conventional myelography often added valuable diagnostic information. Although high resolution CT has allowed limited visualization of the spinal cord, CAM is often indicated for cases in which diagnosis requires more definition of cervicomedullary, extradural, intradural, extramedullary, and intramedullary lesions. Our clinical review found CAM to be extremely useful in the diagnostic evaluation of pathological conditions involving the spine and spinal cord and suggests clinical indications for the use of CAM based upon selected illustrative cases. Furthermore, CAM seemed to be superior to other radiological procedures in certain instances, such as in cases of spinal dysraphism and in the evaluation of lesions at the foramen magnum. Until more experience is obtained using spinal CT and CAM, CAM should not replace myelography altogether. The present study indicates that, rather than replacing conventional CT and myelography, CAM should be used as a primary study in situations where it has been shown to be superior and as a complementary study when other neurodiagnostic examinations are equivocal or nondiagnostic.

Adult↗
PubMed1982

Quantitation of a 55K cellular protein: similar amount and instability in normal and malignant mouse cells.

Quantitative expression of a specific 55,000 (55K)-molecular-weight cellular protein was studied in two groups of mouse embryo fibroblast (clonal) cells originating from two parent clones, one of which possessed high tumorigenicity and the other of which possessed very low tumorigenicity. From the clone with low tumorigenicity, tumor lines and clones were obtained by selecting rare spontaneously transformed highly tumorigenic (mutant) cells. Cells were labeled during exponential growth for 3 h at 37 degrees C, with [35S]methionine, and the cellular 55K protein was immunoprecipitated with a monoclonal antibody and quantitated. There were low and approximately equal amounts of 55K protein in cells (clones) with both low and high tumorigenicity from both groups of cells, and there was no correlation at all between quantitative expression of 55K protein and of cellular tumorigenicity. There was approximately 10- to 20-fold more 55K protein in all simian virus 40-transformed T antigen-positive derivative clones, as shown previously. The T antigen-negative revertant tumor lines and clones obtained by an immunological in vivo selection method had low amounts of 55K protein, similar to the parent cell before simian virus 40 transformation. In all of the T antigen-negative cells, including the highly tumorigenic cells, degradation (turnover?) of the 55K protein was rapid, and a half-life of 15 to 60 min was estimated from pulse-chase experiments. In all of the T antigen-positive cells the 55K protein was stable (half-life greater than 10 h). In primary cells established from the tumors induced by highly tumorigenic cells there was a very low or no detectable amount of the 55K protein. This is in contrast to the primary cells obtained from early murine embryos in which we have reported high amounts of (stable) 55K proteins.

Animals↗
PubMed1982

Supratentorial subarachnoid epithelial cyst: case report and ultrastructural study.

Supratentorial epithelial cysts are rare entities that have evoked controversy regarding their pathogenesis. Recent ultrastructural studies have failed to resolve this controversy. We present a case report and an ultrastructural study of such a cyst. The cyst wall was lined by columnar epithelial cells with prominent cilia and microvilli at their apical surface. They were joined by well-developed junctional complexes and contained abundant intracytoplasmic, electron-dense, granular material, some of which was membrane-bound. These ultrastructural findings suggest that epithelial cysts are derived from elements of the embryological tela choroidea.

Adult↗
PubMed1982

Complications of detachable balloon catheter technique in the treatment of traumatic intracranial arteriovenous fistulas.

As carotid-cavernous sinus fistulas (CCSF) are not life-threatening, therapeutic attempts should carry a very low morbidity and mortality. The authors believe that utilization of detachable balloons is the treatment of choice for CCSF, although this procedure is not without risk. Seven patients have been treated for high-flow traumatic intracranial fistulas over the past 2 years with detachable balloons using a coaxial catheter system. This paper presents several complications that have been encountered during this experience, and advances suggestions regarding treatment and avoidance of potential complications.

Adolescent↗
PubMed1982

Gray-scale ultrasonic demonstration of peripancreatic adenopathy.

The ultrasonic appearance of peripancreatic adenopathy in ten patients is described. The enlarged nodes may appear as well-defined, echo-poor, ovoid or rounded masses in a retropancreatic location, or they may surround and silhouette the region of the pancreatic head and body. The former appearance should be easy to differentiate from primary pancreatic neoplasm, but with a confluent mass of peripancreatic nodes it may be impossible to exclude pancreatic disease.

Adult↗
PubMed1981

Transient diffuse computed tomographic scan enhancement in multifocal seizures.

Previous reports have documented transient angiographic and nucleotide brain scan abnormalities in patients with focal seizures. We describe transient diffuse cortical computed tomographic scan enhancement in a 1-year-old infant with repetitive multifocal seizures. Similar scan abnormalities may be seen in certain asphyxiated infants and occasionally in victims of child abuse. The implications of these findings are discussed.

Electroencephalography↗
PubMed1981

Intraventricular neuroblastoma in a patient wit von Hippel-Lindau's disease. Light and electron microscopic study.

Cerebral neuroblastoma is a rare neoplasm that has not previously been associated with a phakomatosis. We report a case of an intraventricular neuroblastoma in a patient with Von Hippel-Lindau's disease. The neoplasm consisted of process-forming cells containing clear vesicles, dense-cored granules and microtubules. An unusual finding was the presence of intertwining cytoplasmic processes, apparently representing aberrant process formation. We suggest that this case represents a cerebral neuroblastoma occurring as an unusual manifestation of a phakomatosis.

Adult↗
PubMed1981

Delayed hypersensitivity to myxoviruses and myxovirus vaccines in the guinea pig.

Influenza, mumps and measles viruses were examined for their ability to induce in guinea pigs homologous and cross-reactive delayed hypersensitivity. A majority of the animals skin tested with homologous and a portion of the animals skin tested with heterologous viruses and vaccines developed positive reactions. Findings with the heterologous preparations suggest that the observed cross-reactive hypersensitivity might be due to shared antigens of viral or substrate origin in the influenza, mumps and measles preparations. The present findings in guinea pigs suggest that the adverse effects, attributed in whole or in part to induced hypersensitivity, observed in man following injection of killed influenza, mumps and measles vaccines could be due to cross-reactive delayed hypersensitivity resulting from the use of these preparations.

Animals↗
PubMed1981

Brainstem evaluation with CT cisternography.

Seventy-eight positive contrast computed tomography (CT) cisternograms were reviewed to assess the normal anatomy of the brainstem and its surrounding cisterns. Normal brainstem and cisternal anatomy was found to be constant and symmetrical. The review included six patients with brainstem gliomas and five patients with extraaxial masses. In these patients CT cisternography accurately identified mass formation and permitted the confident distinction of extraaxial from intra-axial masses. CT cisternography is a safe and accurate method for evaluating the anterior compartment of the posterior fossa. This procedure is particularly applicable to those cases where conventional CT yields insufficient diagnostic information.

Adolescent↗
PubMed1980

Hereditary spinal arachnoid cysts, distichiasis, and lymphedema.

Familial congenital spinal arachnoid cysts causing progressive paraplegia are reported in two adolescent siblings as part of a hereditary syndrome. The other features of this unusual dominantly inherited disorder include double rows of eyelashes, partial ectropion of the lower eyelids, and acquired late-onset lymphedema of the lower extremities. The siblings' mother, who had roentgenographic evidence of a similar intraspinal lesion, was free of neurological symptoms but had the other characteristic features. Surgical treatment of the arachnoid cysts improves the progressive paraplegia.

Adolescent↗