 According to a popular account that Popa repeatedly challenged, Rainer had claimed the discovery of the hypophyseal portal system some years before Popa and Fielding.In January 1936, together with writers Mihail Sadoveanu, George Topîrceanu and Mihai Codreanu, Popa founded "Însemnări Ieșene" ("Recordings from Iași"), a magazine of commentary.With his intercession, the original group grew to include other intellectuals, including philosopher Ion Petrovici and physician-novelist I. I. Mironescu.