Accepted for Publication: May 16, 2011.
Author Contributions:Study concept and design: Martins. Acquisition of data: Martins, Varma, Elias, and Markmann. Analysis and interpretation of data: Martins. Drafting of the manuscript: Martins and Varma. Critical revision of the manuscript for important intellectual content: Elias and Markmann. Study supervision: Martins, Varma, Elias, and Markmann.
Financial Disclosure: None reported.