Biomedical subjects

E B Spencer

Publications and source records attributed to E B Spencer.

4 recordsLinked to original sources

PubMed1999

Optimizing contrast-enhanced abdominal CT in infants and children using bolus tracking.

OBJECTIVE: Manual administration of IV contrast material results in unpredictable injection rates. Our purpose was to determine the effect of bolus tracking on overall abdominal helical CT scan quality, particularly on hepatic enhancement, in children with manually administered contrast media. MATERIALS AND METHODS: We compared 33 abdominal helical CT scans of 29 children in whom bolus tracking was used with 22 CT scans of a control group of 21 children in whom bolus tracking was not used. All contrast material was administered by manual injection. Qualitative assessment was made of organ and vessel enhancement and overall scan appearance. Quantitative assessment using region-of-interest cursors was performed at three anatomic levels, and the results for the two groups of children were compared. RESULTS: Qualitative comparison of enhancement parameters between the bolus tracking group (number given first) and the control group (number given second) yielded the following: splenic artifact in 9% versus 23% (p = .24); inferior vena cava flow artifact in 3% versus 27% (p = .01); scanning during the nephrographic phase in 89% versus 59% (p = .02); and good quality grade in 79% versus 64% (p = .23). Significantly greater hepatic enhancement (as measured in mean Hounsfield units) was achieved in the bolus tracking group than in the control group at the superior (48.5 versus 28.6; p < .001), middle (47.9 versus 32.3; p < .001), and inferior (48.2 versus 36.5; p = .01) levels. Hepatic enhancement increased significantly from the superior to the inferior level in the control group (p < .02), whereas enhancement was homogeneous in the bolus tracking group (p > .50). CONCLUSION: Bolus tracking provides improved contrast enhancement, including significantly greater hepatic enhancement, during abdominal helical CT in children in whom the rate of injection of contrast material is unpredictable.

Child↗

PubMed1997

Internet image database: development and implementation.

The widespread acceptance of World Wide Web (WWW) hypermedia protocols allows rapid cross-platform development of database interfaces. Using the WWW as the interface promotes easy integration of databases with other publicly available Internet resources. We present our experience with an image database search program (IDBS) developed on the PC platform using freely available UNIX development tools. The database routines were written in PERL. The image database program provides a familiar user interface to a collection of clinical images stored in digital form, either on local media or on the Internet. The design goals of the project and the strategies used to meet them are presented. The source code and a demonstration database are available on the Internet at http:/(/)www.webmedix.com/idbs.

Computer Communication Networks↗

PubMed1997

Recent progress in radioimmunotherapy for cancer.

Radioimmunotherapy allows for the delivery of systemically targeted radiation to areas of disease while relatively sparing normal tissues. Despite numerous challenges, considerable progress has been made in the application of radioimmunotherapy to a wide variety of human malignancies. The greatest successes have occurred in the treatment of hematologic malignancies. Radioimmunotherapy, with or without stem-cell transplant support, has produced substantial complete remission rates in chemotherapy-resistant B-cell lymphomas. Nonmyeloablative regimens have shown so much promise that they are now being tested as initial therapy for low-grade B-cell lymphomas. Although solid tumor malignancies have been less responsive to radioimmunotherapy, encouraging results have been obtained with locoregional routes of administrations, especially when the tumor burden is small. Greater tumor-to-normal tissue ratios are achievable with regional administration. Even with intraperitoneal and intrathecal administration, bone marrow suppression remains the dose-limiting toxicity. Ongoing research into new targeting molecules, improved chelation chemistry, and novel isotope utilization is likely to extend the applications of this strategy to other tumor types. The potential for radioimmunotherapy will be enhanced if this modality can be optimally adapted for integration with other agents and if the administration method can be tailored to the type and distribution of malignancy.

Hematologic Neoplasms↗

PubMed1993

Brain acetyl-CoA carboxylase: isozymic identification and studies of its regulation during development and altered nutrition.

Acetyl-CoA carboxylase, the rate-limiting enzyme of fatty acid synthesis, exists as an oligodendrocyte-associated enzyme in brain and plays an important role in supplying fatty acid for myelination. Rat brain acetyl-CoA carboxylase (ACC) has been identified as a single isozyme of M(r) = 265,000 daltons, indistinguishable immunologically from the isozyme in rat adipose tissue and liver. Total activity of brain ACC declines from birth to 4 weeks of age in the newborn rat. This change in activity can entirely be accounted for by changes in enzyme content, not enzyme specific activity, and is paralleled by decreases in ACC mRNA. In contrast, cardiac, skeletal muscle and liver ACC does not change in content over this developmental period. Unlike ACC in liver and adipose tissue, the enzyme content and specific activity of brain ACC is invariant during various states of nutrition. These data indicate that the brain ACC is subject to unique regulation, as compared to non-neural enzyme. The mechanisms underlying the control of neural ACC activity may be important to understanding the process of myelination during development and to a more general understanding of the factors regulating ACC expression/activity in other tissues.

Acetyl-CoA Carboxylase↗