Biomedical subjects

M Hartshorne

Publications and source records attributed to M Hartshorne.

9 recordsLinked to original sources

PubMed2001

Potential uses of computed tomography-SPECT and computed tomography-coincidence fusion images of the chest.

The ability to fuse (or merge) data sets from SPECT and coincidence nuclear medicine scans with computed tomographic images combines physiologic information from the former method with the superior anatomic resolution of the latter technique. In many cases, this allows more definitive diagnosis than can be obtained by simple visual comparison of nuclear medicine images and conventional cross-sectional imaging. The technique may be used in the staging and follow-up of lung carcinoma, pulmonary carcinoid, and lymphoma. It may also aid in the interpretation of perfusion defects in Tc-99m MAA lung scanning, aid in the interpretation of ground-glass opacity in selected cases of chest high-resolution computed tomography, and aid in the diagnosis of some mediastinal masses (e.g., intrathoracic goiters). In this nuclear medicine atlas, the method used to create fusion images in the chest is described, and examples of fusion imaging with radiopharmaceuticals are given that may be of clinical use in chest disease.

Humans↗

PubMed1999

PLG microparticles stabilised using enteric coating polymers as oral vaccine delivery systems.

Novel poly(dl-lactide-co-glycolide) microparticles for oral vaccine delivery were formulated using the enteric polymers Eudragit L100-55 and carboxymethylethylcellulose (CMEC) as stabilisers. To serve as a control, microparticles were also produced using the conventional PVA surfactant. In all three cases the antigen, ovalbumin (OVA)-loaded microparticles produced were less than 5 microm in diameter and had a spherical, smooth rounded appearance. The presence of surfactants at the microparticle surface was demonstrated by the surface analysis techniques, XPS and SSIMS. Incubation of microparticles with solutions of pepsin or trypsin led to the removal of a proportion of the antigen associated with all three systems. However, in three CMEC-stabilised microparticle formulations and one of three Eudragit formulations, a high percentage of the associated antigen was protected from removal by a solution of pepsin at pH 1.2 compared with the PVA-stabilised microparticles. In addition, with certain CMEC and Eudragit formulations a degree of protection was also afforded to the associated OVA against removal by trypsin at pH 7.4. Following the incubation of microparticles in simulated gastric fluid a higher percentage of intact antigenic OVA was detected in microparticles stabilised using CMEC than in the PVA- and Eudragit- stabilised formulations. Oral immunisation of mice with OVA-loaded microparticles stabilised using either of the three surfactants led to the induction of specific serum IgG and salivary IgA antibodies. Significantly higher levels of specific salivary IgA antibody to OVA were measured in mice immunised with the CMEC-stabilised microparticles than with the other two formulations. This novel approach in PLG microparticle formulation may have potential in increasing the efficacy of microparticulate systems for the oral administration of vaccines.

Administration, Oral↗

PubMed1999

Retrograde perfusion of the spinal cord during aortic crossclamping: initial observations in the swine model.

BACKGROUND: Retrograde perfusion has emerged as a useful technique for the preservation of the heart and brain when arterial circulation is interrupted. Herein, this study was designed to test the hypothesis that retrograde perfusion of the azygos vein is sufficient to maintain viability of the spinal cord during aortic occlusion in the swine model. METHODS: Female swine, 17 to 22 kg, underwent left thoracotomy, creation of a shunt between the aortic arch and the azygos vein, and aortic crossclamping for 60 minutes: the shunt was open in the retrograde perfusion group (n = 5) and closed in the control group (n = 4). The animals were evaluated for neurologic function for 8 days and killed. Spinal cords were processed for histologic examination. Additional animals underwent left thoracotomy and injection of a casting solution in the azygos vein (n = 2), left thoracotomy and angiography of the azygos vein (n = 2), and a compartmentalization procedure to separate the azygos vein from the caval system followed by angiography (n = 2). RESULTS: Differences in the neurologic (2-sample t test, P =.11) and histologic (2-sample t test, P =.65) scores of retrograde perfusion and control groups were likely due to chance. Casting and angiography groups showed extensive collaterals between azygos and caval systems, only partially interrupted by compartmentalization. CONCLUSIONS: Retrograde perfusion does not protect the spinal cord from ischemic injury. The collateral network between the azygos and caval systems prevents the oxygenated blood from reaching the cord. Surgical separation between the 2 systems was only partially successful in this study.

Angiography↗

PubMed1998

I-131 uptake in the breast for thyroid cancer surveillance with biopsy-proven benign tissue.

A 37-year-old woman was seen for recurrent papillary carcinoma of the thyroid after thyroidectomy. After repeated surgery and I-131 therapy, follow-up I-131 scanning and thyroglobulin levels were negative. Subsequent I-131 surveillance, however, demonstrated bilateral breast uptake. A biopsy taken of this area in the right breast proved that the increased uptake was secondary to benign disease.

Adult↗

PubMed1974