In August 2007, John Pedersoli was in the middle of coaching a soccer practice when his wife came to tell him his father, who suffered from Alzheimer's disease, had disappeared.

Pedersoli wasn't alarmed. He assumed he would find his father walking around his Lanham neighborhood, just like the previous times his father had gone missing.

Now it has been nearly two years since Waldir Pedersoli, who was 75 and had trouble walking and seeing at the time of his disappearance, vanished on Aug. 24, 2007. Investigators say they have no new information, and family members are losing hope that he will be found alive.

"The difficult part is that there are absolutely no leads at all, not a shred of evidence, not a clue from anyone," said John Pedersoli, 49, of Greenbelt.

The family plans to hold a vigil Monday, on the two-year anniversary of Waldir Pedersoli's disappearance, to remember him at the neighborhood crossroads where he disappeared, said Waldir Pedersoli's wife, Heleni Pedersoli.

Sept. 5 is the couple's 50th wedding anniversary.

Heleni Pedersoli, 68, said she plans to mark the day by attending church and praying for closure.

"For me, I am not a widow and I'm not married. Where am I?" she said.

Before Waldir Pedersoli was diagnosed with Alzheimer's disease in 2004, he was a veterinary medicine professor at Auburn University in Alabama from 1967 to 1987. He moved to Prince George's County in 1988 to work for the Food and Drug Administration in Beltsville and retired in the late 1990s.

The case is open and classified as a missing person's case, but no new information has surfaced since early 2008, said Officer Evan Baxter, a spokesman for the Prince George's County Police Department. Baxter said investigators declined to give details on information they have found.

"There's no reason to believe he's dead," Baxter said. "We're just waiting."

Waldir Pedersoli had wandered from his home in the 9400 block of Presley Place in Lanham before, members of his family said.

The day Waldir Pedersoli disappeared, he was being watched by his youngest son, Marcello Pedersoli, 43, who lived in the family's home at the time. Marcello Pedersoli, who now lives in Florida, told family members and police that he went downstairs to watch television at about 3 p.m. while his father napped upstairs. About an hour later, Marcello checked on his father and found him missing.

After searching the house and neighborhood, the family called police, who arrived at about 5:30 p.m. and scoured the area for hours. They returned the next day with members of Mid Atlantic Regional Search and Rescue, a New Jersey-based volunteer group that assists in missing person searches.

The rescue team's trained bloodhounds didn't track Waldir Pedersoli past the corner of Presley and Good Luck roads, leading investigators to believe that a motorist picked him up, John Pedersoli said. Waldir Pedersoli's family also suspects he may have boarded a local Metro bus.

His daughter, Miriam Pinheiro, 48, of Beltsville said she is surprised no one saw her father vanish during rush hour.

"As time passes you get less and less confident that he's going to be found," Pinheiro said. "We just don't really think he's alive because of the health problems. It's possible, I guess. It would be a miracle."

Pinheiro said her father wore an Alzheimer's bracelet with contact information. If someone had picked her father up, they likely would have seen the bracelet, she said.

Heleni Pedersoli said her husband still recognized his family, but he often became spatially disoriented, not knowing his way around his home and then wandering outside. Before his disappearance he had reverted to speaking his native Portuguese.

"We really expect the worst, but we would really like to have closure," she said.

John Pedersoli said he is trying to find normalcy.

"It's a true mystery," he said. "Now it's just a waiting game — waiting and hoping that something, someday is going to show up."

To read about Pedersoli's story, visit the America's Most Wanted Web site at www.amw.com/missing_persons/case.cfm?id=65154. Anyone with information is asked to call 800-27463-88 or submit a tip online.

E-mail Liz Skalski at eskalski@gazette.net.