Tomorrow is World AIDS Day, and as I was researching this week's podcast on that topic, I came across something remarkable - the acronym GRID. It was actually the original name for what is today known as AIDS, but what it stands for shocked me: Gay Related Immune Deficiency. Some called it GRID. Others called it Gay Compromise Syndrome or even "gay cancer."

These names didn't reflect hatred or disapproval but rather a limited understanding of the origins and scope of the disease. But 25 years later, knowing what we know now, it really shook my sensibilities. You see, I was born in 1982, the year after AIDS was first reported, so I guess by the time I was old enough to understand this tragic disease, the world understood it better too, and had given it a much more appropriate name.

Now, more than 40 million people worldwide - straight and gay - are living with HIV/AIDS. And 25 million others have already died from the disease, and in many sub-Saharan African countries, AIDS affects more than 20 percent of the population. Those are mind-blowing numbers! Think of it this way: The only thing affecting that many people in the United States is obesity.

But coming up with a better name is not all that's been done in 25 years. Faster diagnostic tests, better treatments and researchers around the world working towards a cure are a good start. We can only hope that the attention paid to the disease each December 1 will bring us closer to eradicating a global killer.

Make sure to check out the "Paging Dr. Gupta" podcast on iTunes and CNN.com/health for some tips on how to prevent the spread of HIV/AIDS.

Video gaming is an amazing industry. It generates about $13 billion a year, which rivals Hollywood. Many video games can be a lot of fun and even provide some benefit for children, such as improvements in focus and concentration. Still, there have been lingering questions about the association between particularly violent video games and subsequent violent real-life behavior. To try to find the answer, the American Academy of Pediatrics looked at more than 1,000 studies, including reports from the Surgeon General's office. Its conclusion: there is a link between violent media images such as video games and aggressive behavior in some children.

Now, for the first time, a study has probed deep in the brain to figure out what is really happening when teenagers play these violent video games. Researchers found that teenagers who played particularly violent video games showed more activation in an area of the brain called the amygdala. This is an area responsible for conflict response and emotional arousal. Additionally, these same teens showed dampening in areas of the brain responsible for inhibitions. So it seemed the violent video games caused both an increase in conflict and emotional behavior while making these kids less inhibited.

To many parents, that sounds like a prescription for disaster. It's important to remember that realistic video games can provide an almost parallel reality for young children who haven't yet had a lot of real life experiences. So, you should choose wisely when purchasing these games, much in the same way you would prohibit children from watching certain movies. And spend some time watching or even playing these games with your children - you will get a better idea of how much impact these games might have. And as we head into the holiday season, I'm curious about any other strategies parents have when buying these games for their kids.

As a doctor, I know one of the most frightening things for a patient to hear is "you might have cancer." I have had to deliver that news on countless occasions, and I know it leads to lots of worry, lost sleep and anxiety. In the case of breast cancer, 80 percent of lesions biopsied are found to be benign. That's good news for a lot of women, but it may also mean that too many breast biopsies are performed. So for years, doctors have been looking for ways to cut that number down. And they may have discovered an answer, called elasticity imaging. The results of a small study on this technology were presented this week at a meeting of the Radiological Society of North America.

Elasticity imaging is really no different from a conventional ultrasound for a patient. As with an ultrasound, the test is completely noninvasive and involves no needles. The difference lies in what happens to the images after that. While an ultrasound is very good at detecting an abnormality in the breast, adding "elasticity" software helps better define the characteristics of those lesions. So, for example a harmless breast cyst would have one distinctive appearance and a malignant tumor would look strikingly different. The hope is that one day a biopsy could be called off, based on ultrasound images alone. We are not there yet.

Your doctor, like most doctors, will probably want to see more studies before they are comfortable trusting this technology. The existing study results, though, are very good. Out of 80 women with 123 suspicious masses, elasticity imaging correctly identified 17 of 17 malignant tumors and 105 of 106 benign lesions. One downside of ultrasound imaging is that it depends very much on the operator's skill - so these terrific results might vary from hospital to hospital.

Still, it is hard to argue with data that are almost as accurate as a biopsy. Almost.

Today one of the heroes in the fight against AIDS, Father Angelo D'Agostino, is being buried in Nairobi, Kenya. The 80-year old was an American, a doctor and a feisty Jesuit priest who fought tirelessly for children in Kenya orphaned by AIDS. "Father D'Ag" rescued his kids from the streets of Nairobi, from hospitals where they had been abandoned and from families that could no longer care for them. He built an orphanage called Nyumbani, which means "home" in Swahili.

His legacy will live on. Even this week, a new village at Nyumbani is opening to care for more AIDS orphans. But as we approach World AIDS Day this Friday, it's an appropriate time to think about the work that is still needed.

According to a new report from the United Nations, every eight seconds a person is infected with HIV somewhere in the world. The numbers are staggering: 40 million people are living with HIV today, and 25 million others have already died in the epidemic's 25 years. The disease has slashed life expectancies, especially in sub-Saharan Africa, where most infections occur in people ages 15-44. Some countries are at risk of losing entire generations, often the most productive people in the prime of their lives - teachers, workers who keep an economy strong, and parents. They leave behind about 12 million children who may not have a home, an education, or perhaps, a future, unless more Father D'Ags come along.

There's much work to be done.

Autism is being diagnosed in more children than ever - 1 in 166, according to the CDC. The disorder affects a 1.5 million people, a number that could grow to 4 million in the next decade, according to the Autism Society of America.

Since we first aired our program on autism last summer, a few things have changed. Back then, autism groups had high hopes for more funding to find the disorder's cause. In August, the Senate passed the "Combat Autism Act," which authorized nearly $1 billion over five years for research. The House was expected to take the issue up this fall. That didn't happen. However, the chairman of the committee where the bill got stuck is still hoping for a compromise in December, before congressional leadership changes hands.

In October, researchers from Vanderbilt University reported that a child with two copies of a specific gene mutation is twice as likely to develop autism than one without the mutations. A month earlier, a study from Israel suggested that if a father is over 40 at conception, his child's risk for autism goes up, possibly because sperm from older men may have more genetic defects. These are just a few more parts of the puzzle of autism spectrum disorders. There are still too many pieces missing.

Tune in to House Call this weekend at 8:30 a.m. ET for more on the causes of autism and the tolls it takes on families. Our guest is Dr. Anshu Batra from Cedars-Sinai Medical Center in Los Angeles, California. In addition to specializing in treating children with autism, she's the mother of two autistic children.

Also this weekend at 8 p.m. ET, watch CNN Presents: Autism Is A World, a rare look at autism through the words of a young woman who lives with it.

This week, I am taking my first full week off this year. My wife could not be more delighted, and I have spent most of today tickling the baby and going for a long run with my dog. Still, I wanted to take a few moments to thank all of you - the readers, the viewers, the bloggers and the simply curious.

At CNN, we are committed to the very highest quality health and medical news. With dozens of hard-working producers in various cities across the country, we are investigating, examining and reporting the news and making sure you are equipped every day with information that you can truly use. And, you show up to watch every single time. In fact I just learned that the premiere of our documentary on happiness last Sunday was the most watched show in its time slot among cable news networks. Amazing. Thanks so much for that.

I have also had a chance to reflect on this past year. CNN has sent me all over the world, including most recently to Africa, specifically Chad and the Congo, to cover the atrocities of war. I have seen things this year that I will never forget. They are terrible, awful things and the truth is, I don't want to forget.

You see, it would be easy to forget; to simply come home, hug my daughter and move on with my life. This year, I have learned that we should not be thankful because we have somehow been dealt a better hand in life. Instead, we should be thankful because we can help those out who are less fortunate. So, this Thanksgiving, the lost boys of Sudan, the famished women I met in Chad, the wounded babies in a Beirut nursery and the brave hospital workers in Haifa all will be on my mind. Please know that I am most thankful to be able to share these stories with the world, in the hope that these people get the help they need and deserve.

For those of you looking for a TV alternative on Thanksgiving Day, CNN is offering four hours of Dr. Sanjay Gupta.

At 2 p.m. ET, "Genius - The Quest for Extreme Brain Power." It's an hourlong look at what it means to be a genius and how you and your children can tap the genius within.

Up next at 3 p.m., Dr Gupta explores "Sleep" - and the link between sleep and your health; what your dreams are telling you, and how to get the best night's sleep possible.

At 4 p.m. there's "Happiness and Your Health - The Surprising Connection" offers an in-depth look at the importance of happiness. Find out how you can be happy - from some of the happiest people on the planet.

At 5 p.m., watch "Memory" - what it is, how to fine tune it and how to keep it as you age.

And for the podcasters out there, don't forget to check out this week's "Paging Dr. Gupta" podcast on the woes of holiday indigestion, and how best to avoid it! You can download it on iTunes or on CNN.com/Health

Happy Thanksgiving to all, and to all...a good meal!

In advance of Thanksgiving, we wanted to find out whether food grown and sold in your own state or region is safer to eat than the food shipped from across the country or overseas.

Our food travels an average 1,500 miles before it gets to our table, and problems can also hitch a ride.

Three people died and 200 were sickened recently after fresh spinach was contaminated with E. coli bacteria. That spinach made it on the menu in dozens of states before it was traced to a farm in California.

I paid a visit to the Georgia Farmers Market just south of Atlanta to find out whether locally grown food is safer. Even at this time of year, food grown in Georgia such as turnip greens and tomatoes are brought to the market and sold to the public or processed on site to be sent to supermarkets and restaurants across the southeast.

Tommy Irvin, commissioner of Georgia's Department of Agriculture, says distance doesn't necessarily mean risk. Locally grown food will be fresher and buying it will help your area's economy but it all comes down to how the food is handled.

Irvin has these simple hints:

- Wash hands often and thoroughly while preparing food

- Clean produce by rubbing briskly under running water to remove dirt and microorganisms

- Cook food to a minimum of 165 degrees, killing all bacteria and viruses

Irvin says fresh or frozen, organic or not... the safety of the produce and the meat you put on your table this Thanksgiving depends on YOU! Food can be perfectly safe on the trip from the field to your kitchen but if you don't go the extra step of washing and preparing or cooking it properly... foodborne illnesses could to come to dinner along with Aunt Ethel.

Socrates was fascinated with the concept of happiness. For our reporting on the subject we talked with experts who are doing work a lot like his - the "new" happiness philosophers, if you will. Most, but not all, work in a field known as positive psychology.

At the University of North Carolina-Chapel Hill, positive psychologist Barbara Fredrickson teaches freshmen how to be happy. Her students learn to savor moments to "extend the goodness" of an experience - for example, not multi-tasking while they're talking on the telephone to people they care about. "Once people learn to appreciate that positive emotions are beneficial to them... it calls us to pay more attention to those moments and not just rush through them," she said.

Dacher Keltner, a positive psychologist with the University of California-Berkeley, says our disposition has an almost "snowball-like" effect on our future. Studies suggest hostile, violent kids often carry their negativity through life, he notes. The same connection applies to happy children.

Barry Kerzin is a doctor but also a monk. Using meditation he can generate positive feelings in his brain by manipulating his thoughts. His good feelings show up in brain scans. I watched him do this for more than three hours inside an MRI machine. He came out tired but blissful. "Meditation is always helpful to calm the mind," he said. He says he's happier now than before he was a monk.

If you're unhappy or depressed, feeling better is a real possibility.

Tune in this Sunday at 10 p.m. Eastern for Dr. Gupta's in-depth report on happiness and its surprising connections to your health.

I thought producing this week's House Call on happiness would be pretty simple, but as it turns out, happiness is a tricky business. Research shows that happy people live longer, laughing can lower your blood pressure and optimists beat out pessimists in a number of health measures.

Being a perfectionist, I thought perhaps we should strive to be happy all the time - after all it's good for your health! However, our guest, Harvard professor Daniel Gilbert, says not so fast. He says we're not programmed to be happy all the time, so people shouldn't strive for constant happiness. Anxiety, anger, and fear all play critical rolls in our survival. Gilbert's example: If you were happy all the time, you might happily let your child go out at 3 a.m. for bread in a bad part of town.

During Gilbert's interview with Dr. Gupta, he talked about where Americans go wrong in their pursuit of happiness. In fact, he said, we don't even know what makes us happy.

Tune in to House Call this weekend at 8:30 am Eastern and hear what this expert says is the key for finding your bliss.

I've never been one to preach to my patients. For the most part, they already know if they should lose weight, exercise more or stop smoking. Still, I do think I wouldn't be doing my job if I didn't occasionally provide gentle reminders. As it turns out, for the last 30 years, I've had some help.

Yes, today marks the 30th anniversary of the Great American Smokeout, sponsored by the American Cancer Society. Literally millions of smokers will say "no thanks" to cigarettes for at least 24 hours. There will be public service announcements, parades, rallies, athletic events and ceremonies with celebrities encouraging people to quit. One year, a national sandwich shop even gave out "cold turkey" sandwiches to smokers who turned in at least a half a pack of cigarettes. The hope is that this one day will push smokers who want to quit in the right direction.

Whether from the Smokeout or increased awareness over the years, we are seeing some positive signs. Recently, we became a nation with a higher number of former smokers (46.5 million) compared with active smokers (45.1 million). Also, in 1964, when the first surgeon general's report came out, there were only 500 community smoking bans. Today, there are 2,300 communities and 18 states with such ordinances. Unfortunately, there are still negative signs as well. We are no longer seeing significant declines in smoking rates among high school students, who represent the next generation of smokers.

Different things work for different people and you will never hear me preach about quitting. You already know what is best. I'm eager to hear how some of you have overcome the habit or are working at it.

Happiness and your health has been the subject of many of Dr. Gupta's appearances on CNN this week, leading up to his special report "Happiness and Your Health, The Surprising Connection" (Sunday, 10 p.m. Eastern).

But in addition to what's on TV, our weekly podcast Paging Dr. Gupta which I just posted on iTunes and CNN.com , has more information on what it takes to be happy. Did you know that a Pew Research Center survey found that being religious or Republican makes it more likely that you'll be happy? And if you're in your 20s as I am, chances are you're not as happy as people in other age groups! I happily disagree, but the studies actually show that men in their 60s are the happiest.

You'll also find great information and some really good pictures of happy people at CNN.com/Happiness, and you can even take a survey on what makes you happy.

Today is day three of the blog, and so far you've sent us some excellent comments, so keep them coming! Please note that although we'll post as many responses as possible, not every response will appear.

All this week, I have been reporting a series of stories about happiness. Now, admittedly, I wasn't sure what to expect when I started investigating this six months ago. And, in full disclosure, as a neurosurgeon, I like objective facts - and I wasn't sure I would find them in the world of happiness. My producers will tell you I was surprised. So, I decided to share a little bit about what I learned.

This morning, I filed a story about the meaning of smiles. Instinctively, most of us can tell when a smile is genuine or fake. We can also usually tell when a person is really happy, or not. But, what is it that we are really seeing?

Well, turns out it's hard to pretend that you're happy when you are not. In a true smile, there are some telltale muscle movements that are almost reflexive in nature. As the corners of the lips go up, there is an almost simultaneous contraction of the muscles under the eye, called the orbicularis oculi. What's even more fascinating is that with a true smile, researchers have found, the area of the brain most associated with happiness, the left frontal lobe, lights up.

Other little signs include a slight pouching under the eyes, which is impossible to reproduce, unless you are truly happy. I tried and couldn't do it. There is also a little crinkle in the cheek - again, hard to fake. Now, if you're like me, you'll probably dig out your own yearbook photo and start analyzing.

Still skeptical? Well, get this: According to our smile expert and his studies, those with genuine smiles in their college yearbook photos were significantly more likely to be happier a full 30 years later. So, if you do look at those old photos, let me know what you find.

Make sure to tune into CNN this Sunday night at 10pm Eastern for my full, in-depth report on happiness and the surprising connections to your health.

A couple of points seemed especially interesting to me about treating heart attacks in time - a story I was researching for a piece on "Paula Zahn Now" for tonight...

The first one is the bad news: Currently, there's no reliable way for a patient to select a hospital that is trained to treat heart attacks and give emergency balloon angioplasties in under the recommended 90 minutes. Only a few hospitals in the country - 1/3 of them - treat at least half of their emergency angioplasty patients in under an hour and a half. Until U.S. hospitals uniformly adopt procedures to minimize the time spent on these patients and make these measures public, heart attack patients are taking a bit of a gamble when it comes to choosing a hospital . How do you know when the odds are going to be stacked against you?

The other part - the good news - is that hospitals that are learning and changing their procedures to treat heart attack patients quickly may not only help save an additional thousand lives in the ER every year, but they may actually be able to "erase" the heart attack altogether. Meaning in some cases, when hospitals manage to open up the arteries quickly (like, say, in under an hour), subsequent heart function tests may not show that there was any damage to the heart muscle, as if the patient had never had the heart attack in the first place! This translates to reduced risk of heart problems in the future, a quicker recovery time, as well as other long-term heart health benefits. And, most of the changes that need to be made are focused on how the cardiac treatment team communicates and organizes itself - so it's not going to cost a lot for hospitals to implement these systemic improvements.

With increased awareness on the part of the hospitals, and a few inexpensive changes in the ER, more Americans can live longer and healthier lives in the aftermath of a heart attack.

If you heard the news this morning about red meat and breast cancer, you may have immediately dismissed it. "I have heard it all before," you thought to yourself. Well, I want you to reconsider, especially if you are a woman in your 20's, 30's or 40's. In a nutshell, the study looked at 90,000 women and found those who ate more red meat almost doubled their risk of developing a specific type of breast cancer, called hormone receptor positive cancer, over the next 12 years.

To be fair, it is really hard to do a study like this. This study was based on questionnaires asking people to remember what they ate and how much. I can barely remember what I had last night, let alone last month. And, we are not really sure why red meat would be linked to breast cancer. It could have something to do with certain compounds in the meat that are released in the cooking process. It could also have to do with the fact that certain cattle are often given hormones in their feed, which could fuel the breast cancer to grow.

Now, Americans eat more red meat than the rest of the world. And, yes, most of us already know we should probably cut down for a variety of reasons. But, here's what I find interesting - there are so many things out there affecting our likelihood of cancer that we can't control, such as family history, but we are starting to accumulate lots of evidence about things we can control. Now, if you had a juicy cheeseburger last night, don't worry - you still have a very low likelihood of ever getting breast cancer. But, here is yet another good reason to cut down

I was engaged in a spirited conversation with a producer as I left CNN for Emory University to check out new technology designed to help our returning warriors through Post Traumatic Stress Disorder. We were discussing what we would do if the researchers put me through the virtual reality therapy and nothing happened. After all, I had been in the Iraq war zone for only a few weeks back in 2003, nothing like the extended tours of duty of our service men and women. This, paired with the usual journalist's approach of "prove it" when it comes to new therapies, led us both to question whether we would have any video to put on the air after this trip to see Dr. Gerardi at Emory.

I wasn't ready for what would happen to my mind and body. Through this technology, which is like a video game and experienced by the patient wearing a wired-up helmet, I truly relived some of the most terrifying moments of my life, those moments when I really thought I was going to die. I could feel my heart pound and my hands shake as the therapist continued to remind me that the purpose of the simulation is to let me experience those moments as realistically as possible, but in a safe place.

I was overwhelmed by my response to this experimental treatment. I felt so out of control with real feelings of helplessness and despair at first. I felt more in control after going through the simulation a couple more times. And that's the goal - to help the military men and women, whose lives are on the line, come home and be in control of their memories and fears.

My experience gave me a new respect for the mental enemies faced by our troops and a new appreciation for the work of those trying to help them.

Tune into Anderson Cooper 360 tonight at 11 PM Eastern to see more about the experience of soliders who return from the war, only to fight equally challenging battles at home.