Rome, September 11 - A group of experts commissioned by the Italian health ministry has submitted a reportedly negative opinion on the controversial Stamina stem-cell treatment, ANSA sources said Wednesday. Italian researchers in July called on the health ministry to stop supporting the treatment after international science journal Nature slammed it as ineffective. The opinion submitted to the health ministry reportedly echoed those findings. Health Minister Beatrice Lorenzin had said the promoter of the Stamina therapy needed to show results of its clinical trials and a detailed protocol. "Nature's report against the Stamina method is very serious and, most of all, raises great concern," said Lorenzin, calling on Davide Vannoni, the president of the Stamina Foundation which developed the therapy, to hand over a protocol without further ado. Paolo Bianco, a top international expert at Rome's La Sapienza University on mesenchymal stem cells, which are used in the therapy, had earlier called on the government to stop the treatment which "should be legally sanctioned by the government and immediately banned from all public hospitals of the national health service". The controversial Stamina therapy questioned by Nature uses the mesenchymal stem cells from bone marrow that differentiate into bone, fat and connective tissue to treat terminally ill patients. Developed by the Brescia-based Stamina Foundation, the treatment was repeatedly banned until the Italian health ministry in March said the therapy could continue in 32 terminal patients, most of them children.