(AP) -- As U.S. doctors in Guatemala were wrapping up one of the most unethical medical experiments they had ever conducted, a Guatemalan medical official praised the lead researcher as noble and thanked him profusely.
The Guatemalan official's praising letter from more than 60 years ago is among thousands of documents released Tuesday concerning the doctor who led the study that infected Guatemalan prison inmates and mental patients with syphilis in the 1940s.
The records released by the National Archives reveal new information about Guatemalan officials' involvement in the research, though it's not clear if they were aware of all the details of what the U.S. doctors were doing.
The papers that belonged to U.S. Public Health Service researcher Dr. John C. Cutler were formerly housed at the University of Pittsburgh but lay in obscurity until a medical historian discovered them. Her finding made international news in October, when the U.S. government acknowledged the research had taken place and apologized for it.
Both President Barack Obama and Secretary of State Hillary Rodham Clinton called Guatemala's president, Alvaro Colom, to personally apologize.
Guatemalan Embassy official Fernando de la Cerda said his country hadn't known anything about the experiment until Clinton made the call.
But the records indicate that just as the experiment was buried by government medical officials in the United States, it was also known and them apparently forgotten in Guatemala.
Indeed, it was a Guatemalan who first proposed the country as a setting for the research. The idea came from Dr. Juan Funes, chief of the venereal disease control division of Guatemala's national health service, who had been assigned to a public health lab in New York for a year, Cutler wrote in a summary of the study.
From 1946-48, the U.S. Public Health Service and the Pan American Sanitary Bureau worked with several Guatemalan government agencies to do studies - paid for by the U.S. government - involving deliberately exposing test subjects to sexually transmitted diseases.
Researchers attempted to infect about 700 prostitutes, prisoners and mental patients with syphilis. About 770 tests subjects, including soldiers, were exposed to gonorrhea.
Patients were treated with penicillin. Among the goals of the research was to see how well differing dosages of penicillin worked against different venereal diseases.
But Cutler's records were not kept with other government documents, and his summaries of the work apparently were never published in a medical journal.
U.S. researchers were in firm control of the research, and it's not clear if each Guatemalan official involved knew all the details of the U.S. doctors' work. The director of the mental hospital - who gave permission for his patients to be study participants - apparently did not know they were being given the disease, noted Susan Reverby, the Wellesley College historian who discovered the study records.
But there's no record of any Guatemalan's expressing ethical qualms with what they did know about.
Quite the opposite: Dr. Roberto Robles Chinchilla, the medical administrator of the Penetenciaria Central de Guatemala, wrote Cutler to express "our everlasting gratitude" for the "the noble and gentlemanly way in which you have alleviated the sufferings" of prisoners at the penitentiary.
"You have really been a philanthropist," he wrote in December 1948, as Cutler was finishing the main part of his research there.
The perception of philanthropy was understandable. The U.S. research money paid for a new laboratory in the headquarters building of Guatemela's national public health service.
At the meagerly equipped insane asylum where much of the syphilis research was conducted, U.S. research money paid for sorely-needed anti-epileptic medications, metal cups and plates, a new large refrigerator and even a movie projector for the residents' entertainment.
Patients who participated were rewarded with cigarettes, not to mention recognition and attention that they had not previously gotten at the understaffed facility. Some were so exuberant they kept trying to return to doctors for additional blood draws or other procedures, Cutler wrote.
But it's doubtful they understood the potential harms they were facing from being infected. Some mental patients did not even know their own names, he wrote.
Cutler later was involved in the infamous Tuskegee study, a different form of research in which black men in Alabama who already had syphilis were followed but not treated.
In 1990, Cutler donated a collection of roughly 12,000 pages of correspondence, reports, photographs, and patient records to the University of Pittsburgh. Cutler died in 2003.
The National Archives announced the records going online with a press release. "This is one more example of National Archives employees' commitment to openness and transparency," Archivist of the United States David S. Ferriero said in a prepared statement.