The purpose of this study is to determine how reliable and reproducible these measurements are and also to define a "normal" value or range of values in healthy people. It is our hope that after we are able to define the normal range of values for oxidative stress we can then look at people with the aforementioned diseases and measure their levels of oxidative stress looking for a correlation between the two. If we can show a direct correlation between level of oxidative stress and these diseases we can begin trying to develop medicines that can target this area and hopefully prevent or lessen the degree of these diseases.