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Archive for May, 2009

There are two general types of prostate cancer, and one of them is very aggressive. Unfortunately for some men, that means surgery is no longer an option by the time it gets noticed. Fortunately, some great forward strides have been made on this front at the Mayo Clinic to give these men a fighting chance.

Dr. Kwon called Dr. Allison and designed the trial together. The idea: use androgen ablation or hormone therapy to ignite an immune approach — a pilot light — and then, after a short interval of hormone therapy, introduce an anti-CTLA-4 antibody that acts like gasoline to this pilot light and overwhelms the cancer cells. MDX-010 (now called Ipilimumab) is the clinical antibody being tested in the Mayo trial.

This has been tested on two patients so far, with very good results, but some caution is in order.

Both investigators are quick to point out that the outcomes in these two patients need to be validated in further studies. Plans are already underway for extended trials at Mayo Clinic to determine the dosage to optimize this therapy and explain how this combined treatment actually works.

“It’s important for us to understand the mechanism of favorable response in these patients,” says Dr. Blute. “This could have significant implications for other forms of cancer, including hormone-sensitive forms, such as breast and ovarian cancer.

Go read the source material for a detailed account of the patients experiences, and to learn a little more about the treatment.

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Cognitive declines are an unfortunate side effect of aging. For scientists to better understand how to prevent it from happening they look to those lucky few who age and remain mentally sharp. One particular group being studied are people over the age of 90 who live in a retirement community.

Laguna Woods Village, a sprawling retirement community of 20,000 south of Los Angeles, is at the center of the world’s largest decades-long study of health and mental acuity in the elderly. Begun by University of Southern California researchers in 1981 and called the 90+ Study, it has included more than 14,000 people aged 65 and older, and more than 1,000 aged 90 or older.

A favorite game requiring a sharp memory is contract bridge. Since forming new memories is one of the first things to be impaired with the onset of dementia, routine players can easily tell when another member begins to have problems.

“When a partner starts to slip, you can’t trust them,” said Julie Davis, 89, a regular player living in Laguna Woods. “That’s what it comes down to. It’s terrible to say it that way, and worse to watch it happen. But other players get very annoyed. You can’t help yourself.”

The real question researchers are trying to answer is whether people who stay involved in mentally engaging activities, such as playing bridge, doing crossword puzzles, or socializing keep themselves sharp as a result of their activities or if they participate in those things because they are already mentally fit. In some cases there appears to be a genetic component.

In studies of the very old, researchers in California, New York, Boston and elsewhere have found clues to that good fortune. For instance, Dr. Kawas’s group has found that some people who are lucid until the end of a very long life have brains that appear riddled with Alzheimer’s disease. In a study released last month, the researchers report that many of them carry a gene variant called APOE2, which may help them maintain mental sharpness.

Dr. Nir Barzilai of the Albert Einstein College of Medicine has found that lucid Ashkenazi Jewish centenarians are three times more likely to carry a gene called CETP, which appears to increase the size and amount of so-called good cholesterol particles, than peers who succumbed to dementia.

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Before you get all grossed out and try to blame us for losing your lunch, take a moment to ponder the seriousness of this question. At some point in our evolutionary history, it made sense for us to lose body hair. The advantage in having little or no body hair has to do with the human ability of running upright. We are actually the most energy efficient runners (next to dogs) in the animal kingdom, and one way such a thing is possible is through an efficient cooling system, via sweat. Sweating works much more effectively without fur getting in the way of course.

Now, back to our original question.

Robin Weiss, a virologist at University College London, had an intimate revelation in the shower recently.

Public hair, he decided, developed as a sexual ornament. It became bushy and prominent after our ancestors split from non-human primates, he says, when we lost most of our other body hair. As it disappeared, human pubic hair acquired a new role as a prominent sexual ornament, a visual signal of sexual maturity and possibly a reservoir for sexual pheromones.

This theory is actually supported by examining the DNA of lice, both the human and gorilla versions.

Our ancestors and those of gorillas went their separate evolutionary ways at least 7 million years ago. But the lice that infect gorillas and modern humans didn’t become different species until much later – around 3.3 million years ago, as revealed through research in 2007 by David Reed of the University of Florida Natural History Museum in Gainesville.

Reed argues that gorilla lice crossed over to humans through incidental contact, such as humans sleeping in an abandoned gorilla nest. Weiss argues that the pubic hair in humans evolved to become coarser, which gave the gorilla lice something to get a grip on.

To back up his case Weiss visited zoos to peer at the groins of our closest relatives. He noticed that in other great apes, hair in the pubic region was if anything much finer and shorter than elsewhere on the body – the opposite of the human situation. It supported his argument that human pubic hair is different and probably unique, both in its evolution and in its physical appearance and purpose.

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This is a serious question.

From an evolutionary standpoint, it might make sense for women to devote their cellular efforts to reproduction instead of developing an energy-hogging brain, Ward suggested. Females of plenty of other species make this compromise, so why not humans?

The answer is that human females with larger brains had a significant fitness advantage, probably due to the complexity of human social interaction.

Developing big brains must have helped women pass on their genes, she reasoned. One possible explanation is that these larger, more connected brains helped ancestral females navigate an increasingly social world, where gaining benefits from other humans is just as important to survival as traits that improve fitness more directly, such as a strong immune system.

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