Thursday, December 15, 2005

Some stories never get old...

...especially if you haven't heard them before. The story of a king finally gets told some 2000 years later thanks to the amazing discovery of an ancient Mayan mural dating back to 100 B.C. Click on the image below, courtesy of National Geographic, for more info...

Photo: Maya mural of San Bartolo

Also, interestingly, the "Body Worlds" exhibit which was in Chicago earlier this year, has started stirring up controvery in Florida, and now in New York. The bodies are from Chinese prisoners and unidentified bodies that no one claimed. The issue is that the people whose bodies are being used never gave any informed consent to donate their bodies to science or for such an exhibit.

Back in July, I expressed my own concerns about the commercialization and public display of the bodies. The organizers of the display state that they obtained the bodies legally from the Chinese government. The exhibit has attracted record audiences and as a result, the museums don't seem to be saying much at all about the ethics of the situation. Guess money talks loud enough for them...

Monday, December 12, 2005

Growing out a little heart...

I attended a fascinating lecture today by Dr. Joshua Hare, MD, from Johns Hopkins University here at the University of Chicago. He talked about research he is doing using stem cells from bone marrow to repair hearts damaged by heart attacks.

While the public debate over embryonic stem cells continues to rage, many researchers are avoiding that ethical quagmire altogether and simply using the stem cells that already exist in the body for their research. It has long been known that some adult stem cells exist in the bone marrow because they are responsible for generating new white and red blood cells, which the body is continually replenishing as old ones die out.

Embryonic stem cell researchers would contend that adult stem cell are not as useful as the embryonic ones because they are too mature (or differentiated). They believe that only embryonic stem cells that will allow us to achieve the goal of "regrowing" organs damanged by injury or disease.

In his presentation, however, Dr. Hare pointed out that one of the biggest problems with embryonic stem cells is that they tend to form teratomas, a type of tumor. Adult stem cells, when implanted or injected into damaged tissue, do not seem to be as likely to form such teratomas.

Dr. Hare discussed his research in which they took a certain type of adult stem cells from the bone marrow, called mesenchymal stem cells (MSCs), and injected them into heart tissue that was damaged by a heart attack. Tissue that is damaged by a heart attack is dead tissue, because it no longer receives any blood flow. This dead tissue can no longer contract, or beat, and is usually weaker than the remaining heart tissue.

After about two months, Dr. Hare's team found that new heart tissue had grown in the spot where the mesenchymal cells were injected. Not only that, but this new tissue was actively beating, in sync with the rest of the heart! An area of the heart that was totally dead and not beating had regained its function and started contracting again.

The question for Dr. Hare and his team is whether this new tissue is the result of the MSCs transforming into cardiac myocytes (the cells that make the heart beat) or whether the MSCs stimulate the heart to produce these myocytes.

This second hypothesis comes from the fact that adult stem cells have been discovered in the heart. In 2004, research by Messina established the existence of cardiac adult stem cells. This was a major breakthrough because the prevailing dogma has been that our organs are "terminally differentiated", that they have reached the limit of their maturation, and thus do not have adult stem cells. Messina's research, and research like hers, is starting to reveal that stem cells may be more ubiquitous than previously imagined and that our organs may be more flexible and dynamic than we ever thought.

Dr. Hare's technique of injecting MSCs into damaged cardiac tissue (called "cellular cardiomyoplasty") is exciting because it offers the chance for therapy that actually reverses the damage of a heart attack. This is far ahead of current therapy which assumes that a heart attack will cause a certain amount of irreversible damage (depending on how large the heart attack is) with therapy aimed to minimize its progression. This has given rise to the concept of "cardiac regenerative therapy" in which one can actually regenerate at least some of the dead tissue and its function.

These initial experiments were done in pigs and Dr. Hare and his team have already moved into Phase I clinical trials, to see if they can replicate their success in humans. If so, it heralds an exciting new era of treatment in medicine.


1. "Cardiac repair with intramyocardial injectionof allogeneic mesenchymal stem cells after myocardial infarction." Luciano C. Amado et al. Proc Natl Acad Sci USA. 2005 Aug 9;102(32):11474-9.

2. "Isolation and expansion of adult cardiac stem cells from human and murine heart." Elisa Messina et al. Circ Res. 2004 Oct 29;95(9):911-21.

Sunday, December 11, 2005

Diet Coke vs Coke Zero: what's the diff?

I drank some Coke Zero this weekend for the first time. I know, very adventurous...

[Dude, man, I had a great weekend.
No way bro, what'd you do? Surf on Lake Michigan? Parachute off the Hancock?
Naw dude. I did the Zero.
You did the Zero! Bro, you know you can't be doin' that stuff. Whoa. The Zero.]

While I was drinking it, though, I couldn't help but wonder, how's it different than Diet Coke? I thought maybe it was a little sweeter, but couldn't be sure. So I did some investigation and, luckily, there is a blog devoted to dieting, called Diet Blog.

And they cleared it up for me: Coke Zero has half the aspartame and more of acesulfame potassium (called ace-k in diet lingo), another sweetner.

The same blog also has a post about how Coke is going to come out with a coffee drink that is half cola and half coffee, called Coca Cola Blak. Yep, those of you mixing your Starbucks and your Coca Cola can now come out of the closet. Coke's going to do it for you...

My current favorite diet drink: 7UP Plus Island Fruit. Technically, not diet, but only 10 calories per 8oz and it has calcium with 5% fruit juice. It's yummy.

Thursday, December 08, 2005

Snowed in...

From the inside looking out, the snow that is steadily falling tonight looks wonderful, fat big flakes plopping down on the ground, blanketing everything in the powdery snow. Tree branches, that have long been bare, seem adorned with glistening silver, and the dusty brown sidewalks are carpeted with white, inviting someone to be the first to leave their footprints. Even the streets cratered with potholes are filled in tonight, making the roads look like smooth paths suitable for a sleigh ride (...but which are probably better traversed with a Hummer...)

I reflect on all this tonight because I have the time to do so. I'm at the U of C these days, into my second week of a heart failure/transplant rotation, and the marvellous snowfall has also shut down traffic on the highways, with the local traffic report indicating that it will take me more than 3 hours to get home, for a commute that normally takes 45 minutes to an hour.

As I walked to the Regenstein library, I had a few moments to realize how utterly transforming and beautiful the snow really is. And I also realized how it's been a while since I've noticed that; for perhaps the past few years, I looked at snowfall as a nuisance that slushed up the roads and added an hour or two to my commute.

I find that kinda sad really, I mean I remember how much I used to love playing in the snow as a kid and how snowfall was about the most exciting thing that could happen in the winter. It has been a long while since I've built a snow fort, a snow man or even had a good old-fashioned snowball fight.

So it was nice to be on campus, to walk through the snow and just enjoy it. Let it snow, let it snow, let it snow. I'll deal with the commute in the morning.