DEAR ABBY: More than 10,000 baby boomers in the U.S. turn 65 every day, and enter the "age of risk" for Alzheimer's disease. I have witnessed the devastating effects of this disease in my work as a neurologist, as a clinical researcher, and sadly, in my own family.

The good news is that we are now starting prevention trials to try to stop memory loss before it begins! The A4 (Anti-Amyloid Treatment in Asymptomatic Alzheimer's) Study is the first clinical trial designed for people who have the earliest signs of Alzheimer's disease beginning in the brain, but don't yet have any symptoms of the disease. The A4 Study is enrolling healthy 65- to 85-year-olds across the country who may be at risk for memory loss due to Alzheimer's disease.

I feel a new sense of hope, but we really need volunteers to join us. Our motto for the A4 Study is "Now is the time," and now really is the time to make a difference in defeating Alzheimer's disease. I hope your readers who are interested will call (toll-free) (844) 247-8839 or visit A4study.org to receive more information or to join us. -- REISA SPERLING, M.D., PROJECT DIRECTOR, HARVARD MEDICAL SCHOOL

DEAR DR. SPERLING: I'm pleased to alert my readers to your clinical trial. Living to a "ripe old age" can be a mixed blessing because the older we get, the greater the likelihood of Alzheimer's disease entering the picture.

Readers, Dr. Sperling is looking for subjects with a family history of Alzheimer's disease or who, through prescreening, have been discovered to have amyloid plaques forming in the brain. There are more than 65 study sites throughout the U.S. and several in Canada, so you may be able to find a location near you.

DEAR ABBY: I have been somewhat taken aback by two retirement party invitations I received lately. Both require an "entrance fee" of $15 to $20. I have never heard of or experienced something like this before. When I retired from teaching 10 years ago, I held my own retirement party at my home. I supplied the food and beverages and requested "no gifts, please."

Is there a new custom that requires people to pay an admission price to a party? If someone pays to go to the party, is he/she also expected to bring a gift? Honestly, I'm a little put off being asked to pay to celebrate my friends' retirements. Should I be, or is this an appropriate request? -- WONDERING IN OHIO

DEAR WONDERING: I don't blame you for feeling put off. I don't know who is supposedly giving the parties for your friends, but if you're being asked to pay for your food and beverages, it appears that no host is. If you pay to attend these parties, your presence should be your gift. And if you choose not to go, I wouldn't blame you.

DEAR ABBY: My ex-husband had an affair with a woman who was one of my dearest friends. My heart is broken; my marriage is over. I have lost my home and my friend. It has been a struggle for me to recover.

My daughter, with whom I am very close, continues to have a relationship with this woman. While I know it's not my place to tell her who to be friends with (she's 22), I can't help but feel betrayed.

My daughter is pregnant, and this woman seems to be attempting to play mother and push her way into every detail of my daughter's pregnancy. It's extremely upsetting to me to have to share one more thing with her. She already took my home and husband; I would like to keep my daughter and grandbaby. What to do? -- THE REAL GRANDMA-TO-BE

DEAR REAL GRANDMA: Although you cannot cut this woman completely out of your life because she is now with your ex, calmly discuss this with your daughter. She may have reasons that you are unaware of for wanting to include the woman to the extent that she has.

DEAR ABBY: We need help with our dad. Many of his grandchildren participate in sports. For some reason, he thinks it's perfectly fine to sit in the stands surrounded by people he doesn't know and loudly criticize the other players.

We talk to him before the games. We remind him that he's sitting by these players' parents and what he's doing is not cool. Some of the parents become quite emotional if things don't go well and Dad doesn't need to be doing this. Yet he continues.

Have you any ideas on getting Grandpa to keep his opinions to himself? We don't want to ban him from games and treat him like a 5-year-old who can't behave, since he is still able to travel to see us for these visits. We try to sit away from others, but it's not always possible. -- EMBARRASSED IN HOUSTON

DEAR EMBARRASSED: You already know the answer to your problem, and I do not understand why you haven't taken action. Was your father always this way, or has he become demented? When an adult acts like a 5-year-old and behaves inappropriately after having been cautioned against it, there is cause for concern.

If he is unable to control his behavior at those games, instead of being allowed to ruin them for everyone within earshot, he should absolutely be banned from attending. If you won't do it for the sake of the players and other parents, then do it for your father's safety because one of these days, an irate parent or relative may punch his lights out.

DEAR ABBY: My niece was married by a justice of the peace in October. She and her husband are having a church wedding this summer. What would be the proper date to recognize on a gift? -- DONNA IN NORTH CAROLINA

DEAR DONNA: If you are having the wedding gift engraved, you should ask your niece which date she and her husband would prefer.

DEAR ABBY: My husband and I have been into swinging for 20 years. Everything has always been "no strings attached." I was with one man several times before he married his current wife. She's very religious, not into swinging and doesn't know he is.

I'm so attracted to "Nick" that I dream about him and have met him outside our marriages. I know it's wrong, but I can't keep him out of my mind. My husband doesn't know, and I know it would hurt him deeply. Should I tell Nick, or quit writing him on our swinging site? -- DESPAIR DOWN SOUTH

DEAR DESPAIR: And what have you to gain by revealing your feelings? If you think it would make Nick leave his wife, forget it. Because you know it would hurt your husband -- although I'm having trouble understanding why, because you're swingers -- I recommend you refrain from causing him pain.

DEAR ABBY: My family has been put in a difficult position. Last year, a woman my brother had a one-night-stand with became pregnant. I have heard from more than one person that she's known as the town tramp or "crazy."

We're sure she planned it because he makes a good living and can support the child financially, and she insisted on keeping the baby. My brother, God bless him, is doing what's necessary, although having a child with a woman he has come to despise weighs heavily on him.

How should we, his family, handle this? At this point, I have no interest in laying eyes on her or her baby, blood kin or not. I feel no affinity for the child because I know my brother didn't want it. Maybe in time, I could find a way to know this child, but for now my anger prevents it. -- LIVID SISTER IN TEXAS

DEAR LIVID: None of this is the fault of the baby. No one forced your brother to sleep with the "town tramp." I respect him for living up to his responsibilities to his child.

You have nothing to lose by being kind to your nephew/niece and his/her mother. Frankly, it appears she could use befriending, and in the years ahead that baby may need a stabilizing female influence.

DEAR ABBY: My new father-in-law always greets me with a hug and a kiss on the mouth. I come from a family who doesn't kiss on the lips, and I find it extremely awkward. I'm not sure how to handle the situation.

I don't want to bring it up to him because I'm afraid it would be offensive. I have mentioned it to my husband, who kind of shrugged it off, saying his father is "old school." I have started turning my head when we greet so that he hits my cheek instead of my mouth. Please advise me on how to deal with this. -- TURNING A CHEEK IN MICHIGAN

DEAR TURNING: I think you're handling the situation well. If your father-in-law asks why you're turning your head, all you have to do is smile and say you save kisses on the mouth for your husband.

P.S. I don't know what "old school" your father-in-law attended, but I wouldn't set foot on that campus.