The man overseeing the Gates Foundation’s multi-billion-dollar global health initiative helped plan an aggressive effort to squelch a researcher trying to warn the public of possible dangerous side effects to the drug Avandia, newly released e-mails show. In 2006, the Gates Foundation picked Dr. Tachi Yamada to oversee its $5.7 billion global health portfolio, which funded efforts to combat some of the biggest public health problems facing the human race: HIV/AIDS, tuberculosis and malaria. But in 1999, Yamada worked for pharmaceutical giant SmithKline Beecham, and he faced a very different problem: a medical researcher named Dr. John Buse had identified what he thought were potential signs of dangerous side effects to the firm’s new diabetes drug, Avandia, which was awaiting approval by the Food and Drug Administration. He was discussing those concerns in public presentations, at a potential cost of billions to the company’s value. A spokesperson for the Gates Foundation declined to comment and referred questions to David Marriott, a crisis management specialist hired by Dr. Yamada. Marriott said that Yamada was out of the country and could not respond. A spokeswoman for GlaxoSmithKline, Nancy Pekarek, said she did not know "what anybody said or did not say to Dr. Buse," but "we regret if he feels that anybody at any time said something that would have been contrary to the spirit of what we believe is open and scientific debate." Click Here for Full Blotter Coverage. According to e-mails recently released by Sen. Charles Grassley, R-Iowa, Yamada participated in an internal discussion among top SmithKline Beecham executives on how to handle Buse’s concerns. The executives debated whether to sue Buse, "warn" him against continuing to speak about his findings or complain to or even "threaten" his superiors. In one e-mail to Yamada, with the subject line "Avandia Renegade," an executive writes to say that some colleagues want "to write him a firm letter" to "warn him about doing this again." The possible "punishment," the executive wrote, would be "that we will complain up his academic line and to the…bodies that accredit his activities." The downside of complaining to Buse’s superiors, he wrote, was that "we don’t really do too much work at UNC to make any threats." In his response, Yamada suggested the company either sue Buse or launch a campaign to discredit his findings. "One [course of action] is to sue [Buse] for knowingly defaming our product," Yamada wrote. "The other is to launch a well-planned offensive on behalf of Avandia so that listeners begin to understand…there are two sides to this story." Read the ‘Avandia Renegade’ e-mails. Grassley released the e-mails as part of a speech on the Senate floor Sept. 12, inserting the documents themselves into the Congressional Record. They were previously reported on in New Scientist magazine. Earlier this year, Buse alleged that in 1999 company executives made thinly veiled suggestions that they might sue him after he expressed concern about potential dangers of Avandia. Buse told Congress a SmithKline Beecham executive telephoned Buse’s supervisor at UNC to say Buse was a "liar," and that Buse would be held liable for the billions of dollars in value SmithKline Beecham lost as a result of his findings. Yamada has not publicly commented on Buse’s allegations. Buse’s study concluded that Avandia use could lead to an increased risk of a heart attack. He spoke about his findings before the American Diabetes Association and another group, prompting the actions from Yamada and other executives. Shortly afterward, Buse agreed to sign a "clarifying statement" for investors written by SmithKline Beecham, he told Congress in June. He has since distanced himself from his earlier findings and said he bears "no ill will" towards the company. Earlier this year, he became president of the American Diabetes Association. GlaxoSmithKline, and other major drugmakers, contributes more than $1 million annually to the group. In May, the New England Journal of Medicine published an analysis underscoring the risk of heart disease to Avandia users. In July, a German researcher concluded Avandia was linked to heart disease and bone fractures, and increased users’ chances of developing edema, or swelling. GlaxoSmithKline maintains that Avandia is safe, although critics continue to call for the drug to be taken off the market. In July, a Food and Drug Administration panel recommended keeping the drug available, with a strengthened warning label. The internal e-mails released by Grassley also call into question statements made by GlaxoSmithKline president Dr. Jean-Pierre Garnier, who was copied on the e-mails. Garnier has denied the threats happened, since the episode came to light this year when Buse testified before a congressional committee about the affair. "We don’t threaten people," Garnier told the Times of London newspaper in June. In July, he told the Philadelphia Inquirer that "he was not present and did not know what his executive had said," the paper reported. The company did not make Mr. Garnier available for comment. Click Here to Register for Blotter Alerts.