OMAHA, Neb.—The University of Nebraska is investigating questions raised about the integrity of a study conducted by researchers at its Medical Center.

The study was done by five researchers affiliated with the Nebraska medical school and two from Temple University School of Medicine in Philadelphia.

They studied the role of some proteins involved in a lung complication associated with the AIDS virus, the Lincoln Journal Star reported. An abstract of the study said results suggested that artificially manipulating a cellular switch could help people recover from swelling by inflamed tissue that surround lung air sacs.

The American Journal of Respiratory and Critical Care Medicine published the study online in February. But a posting on its website says questions have arisen about data that accompanied the study article.

The journal posted an "expression of concern" on Aug. 1 and said it is withholding print publication of the article, pending the inquiry by the University of Nebraska.

Temple spokeswoman Rebecca Harmon said Thursday that she couldn't immediately comment.

Sheila Wrobel, chief compliance officer at the University of Nebraska Medical Center, told The Associated Press that the university began its inquiry in late July and has 60 days under federal rules to determine whether a full investigation is warranted. This initial inquiry could also confirm the validity of the research.

Wrobel said it's very unusual for questions like this to come up about research.

"Anytime a university that's a grantee, or that's involved in research receives allegations of potential misconduct, they have an obligation to conduct an inquiry and assess the facts to maintain the integrity of the science," Wrobel said.

The American Lung Association and the U.S. National Institutes of Health paid for the study in question, so University of Nebraska officials are following federal guidelines for the inquiry.

If a full investigation is required and UNMC investigators believe misconduct was involved, the individual researchers could be suspended from receiving federal research money and the UNMC might be asked to refund the original grant.