Affiliation: | aG. F. Adami is an assistant professor, P. Gandolfo is a graduate student, and N. Scopinaro is an associate professor in the Istituto di Clinica Chirurgica, Universitd di Genova, Genova, Italy;bA. Campostano is in the Divisione di Medicina I, Ospedale S. Martino, Genova, Italy;cG. Ravera is an associate professor and A. R. Petti is a graduate student in the Istituto di Statistica Medica, Universitd di Genova, Genova, Italy |