USC trustees, in their first public statement since the removal of the university’s longtime student health center gynecologist, said this week they were “troubled” about Dr. George Tyndall’s conduct but have “full confidence” in university President C. L. Max Nikias to carry out a just-released “action plan” to address problems and put better safeguards in place.

The Board of Trustees’ pledge of support for Nikias came amid word that some 200 USC professors have signed a petition demanding the resignation of Nikias, saying he’s “lost the moral authority to lead” in the wake of revelations of years-old misconduct complaints against Tyndall.

In the petition, faculty members wrote that they had come together to “express our outrage and disappointment over the mounting evidence of President Nikias’ failure to protect our students, our staff, and our colleagues from repeated and pervasive sexual harassment and misconduct.”

The letter calling for a regime change at USC — signed by representatives of 14 different schools within the university — called upon Nikias “to step aside, and upon the Board of Trustees to restore moral leadership to the university.”

The developments came a day after six former USC students filed what are believed to be the first lawsuits against the university related to Tyndall’s removal, which the university acknowledged in response to a months-long investigation by the Los Angeles Times.

One of the lawsuits was filed in Los Angeles federal court and proposed class-action status on behalf of former students who were allegedly abused by Tyndall.

In one lawsuit, four women identified only as Jane Does contend that Tyndall forced them to strip naked and groped them under the guise of medical treatment for his “sexual gratification.” The suit also accuses the

university of failing to properly respond to complaints about Tyndall. “Plaintiffs are informed and believe, and on this basis allege, that defendant USC benefited financially from actively concealing myriad complaints of sexual abuse made by its female students against Tyndall by protecting its own reputation and financial coffers,” according to the lawsuit.

Attorney Gloria Allred said she would be filing a similar lawsuit on behalf of a young woman who attended USC.

Tyndall, 71, has denied wrongdoing. In interviews with The Times, the physician defended his medical exams as thorough and appropriate, and said some of his comments to patients were misinterpreted.

Ariela Gross, an expert in race and slavery who holds the title of John B. and Alice R. Sharp Professor of Law and History at USC, helped draft the letter on behalf of the professors, describing it to The Times as “a there’s-no-turning-back, regime-change letter.”

The newspaper reported that she and several law school colleagues began circulating it to tenured professors on Sunday and had little trouble getting signatures.

“There’s a deep well of frustration across the university that the university has lost its way. It is harming our students and it is harming our reputation,” said Gross, who has taught at USC for 22 years.

Nikias last week apologized in writing to women who claim they were abused by Tyndall. The president said he is struggling to understand how the doctor was allowed to continue treating patients for decades.

The subject of numerous complaints from students and staff beginning in the 1990s, Tyndall was removed from the clinic only after a nurse reported him to the rape crisis center two years ago, according to former patients and

staffers interviewed by The Times.

An internal university investigation last year concluded that his pelvic exams were outside the scope of current medical practice and amounted to sexual harassment of students. Campus administrators told The Times they believe the physician had for years been making sexual comments and touching patients inappropriately during the exams.