The research protocol was approved by the Veteran Affairs and Stanford Institutional Review Boards and informed consent for testing was obtained from all patients.
El protocolo de investigación fue aprobado por el Comité de Ética del Veteran Affairs Health Care System y de la Stanford University School of Medicine.
O protocolo de pesquisa foi aprovado pelo Veteran Affairs e Comitê de Ética Institucional de Stanford e termo de consentimento livre e informado foi obtido de todos os pacientes.