Federal officials are investigating media reports that a surgeon at Memorial Hermann Hospital in the Texas Medical Center is accused of denying liver transplants to some of his patients. The hospital announced on Thursday it had found evidence that Dr. J. Steve Bynon Jr. had altered transplant databases in order to make some of his patients ineligible for liver transplants. Memorial Hermann suspended its liver and kidney transplant programs this month after discovering irregularities in the databank. The Department of Health and Human Services is looking into the matter.