Date of Award

6-26-1997

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Physics & Astrophysics

First Advisor

Glenn I. Lykken

Abstract

The focus of this study was to measure alpha and beta emissions of $\sp{210}$Po (alpha emissions), $\sp{210}$Pb and $\sp{210}$Bi (beta emissions) from brain samples which were obtained at autopsy from persons who were clinically diagnosed with Alzheimer's Disease (AD), Parkinson's Disease (PD), or Controls (no known neurological diseases) and cigarette smokers (SMK). The samples were digested, processed and analyzed for alpha and beta emissions.Measurement of alpha and beta radiation activity in tissues can be used to demonstrate prior exposure of tissues to environmental radioisotopes and/or their decay products. In the present study alpha emissions from brain tissues were measured with surface barrier detectors; beta emissions were measured with a liquid scintillation counter. Initial measurements indicate increased level of $\sp{210}$Po (alpha emissions), $\sp{210}$Pb and $\sp{210}$Bi (beta emissions) in patients with AD. Alpha and beta activities in AD brain tissues were approximately two orders of magnitude greater than alpha and beta activity from brain tissues from patients with PD or with no neurological diseases (controls).Because the solubility and the dynamics of binding of radon and its progeny are dependent upon the type of fatty tissue, it was necessary to extract the lipid and protein fractions from the brain tissues (gray and white matter). This allowed comparison of the alpha and beta activities from the two different fractions. After processing and counting each type of fraction, it was found that the majority of the alpha and beta activities came from the protein fraction in the AD brain samples. However, the majority of the alpha and beta emissions came from the lipid fraction in the PD brain, while the lower emissions in the controls were approximately evenly distributed.Alpha particle emissions were consistent with radioactive decay of $\rm\sp{210}Po$ and beta emissions with radioactive decay of $\sp{210}$Pb and $\sp{210}$Bi. It was found that patients with AD and SMK had greater accumulations of $\sp{211}$Pb and/or its daughters in brain tissue than patients with PD or controls.

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