Fish, kidneys and stem cells

Teleost fish are unique in that they are able to regenerate many different types of tissues throughout their lives, including cardiac, retinal, and renal (kidney) tissues.  Many of these regenerative abilities occur through the action of stem-cell like populations.  Identifying stem cells in fish may help researchers identify analogous cells in human tissues. 

The ability of some fish to regenerate renal tissues is particularly interesting because there is currently no known kidney or nephron (the functional unit of kidneys) “stem cell” in humans.  A recent paper looked at using zebrafish to try to identify nephron stem cells. 

To find out more, check out my latest post for the Stem Cell Network.

Read Full Post »

Beer, sausage and stem cells

I’m going to Germany in the summer and thought I might get some work done while I’m there.  In between the requisite eating and drinking of course.

If anyone hears about any interesting stem cell related research coming out of Germany, please let me know or send the link to the paper!  I would love to contact researchers for a meet and greet and do a little write-up about their work.  I’ll be in and around Frankfurt, Berlin and Munich over three weeks.

Read Full Post »

RECOMB2011 fail

So I originally planned on writing a quick post promoting RECOMB2011, a conference focusing on computational molecular biology occurring later this month in Vancouver, BC.  I sent the conference organizers an email asking if they had any stem cell related abstracts being presented, explaining that I wrote for a large stem cell organization on stem cell related topics and events.  I also mentioned that I was a programmer/developer who was interested in computational biology.

No response.

I’m a little miffed to say the least.  I included a link to the Stem Cell Network and everything!  If they were not interested or they did not have stem cell topics as part of their conference, a simple “No thanks” would have been sufficient.

Fail.  No link for you!

Read Full Post »

Proposed shark fin legislation in California

The ongoing debate over shark fin soup continues in California with proposed legislation which aims to curtail the import of fins and prevent the brutal practice of “finning”. Currently, it is illegal to bring in sharks without the fins, but a loophole exists which allows for the import of fins from countries such as China and Mexico, where animal protection legislation is lax or non-existent. If passed, California would join Hawaii in the efforts to prevent shark fins from making it into the soup bowl.  The New York Times recently reported on the issue from California, bringing to light many different viewpoints from the Asian community.

I admire many of the opinions expressed by many of the first generation Americans quoted in this article. It is hard to go against family tradition, especially notoriously traditional Asian families. The concerns they express – environmental and ethical – are backed by science and fact. Finning is cruel and wasteful. Finning not only causes the pain of amputation but also condemns the animal to die slowly, either from suffocation or from being defenselessly picked apart by opportunistic scavengers. Ecologically, the removal of the top ocean predator would be devastating in terms of balance.

In contrast, many of the arguments put forth by their elders seem petty if not downright foolish – the notion that we should be free to eat whatever we want, whatever the cost; the idea that tips for waiters would decrease without shark fins for soup; and so on. Pitted against damning evidence that the shark populations is on the brink of disaster, it is hard to find any respect for this viewpoint.

Many groups have used “culture” as reasons for continuing destructive practices – usually in relation to hunting and eating. The whale hunt is another example. Though perhaps less vicious and less wasteful, it ignores the fact that we are still willfully eating species into extinction. We forget that our technological advances and our incredible ability to kill and destroy efficiently has far outstripped that of our long ago ancestors. And for what? A small bowl of soup, gained at the expense of an animal left to die for lack of appendages?

Read Full Post »

Whales and the contradictions of cancer research

I love Carl Zimmer.  I think he’s one of those people who just really get it… and not only does he get it, but he explains things in a way that makes other people get it.

Recently, he published an article on the Loom discussing whales and cancer, based around a recent review published in Trends in Ecology and Evolution.  The basic premise of cancer works like this:

• Over time, cells make mistakes in DNA replication
• Mistakes accumulate and eventually, mistakes will affect some vital process
• This causes cancer

This stands to reason then, that the more cells you have and the longer you live, the more mistakes you will have, and the higher likelihood that you will have cancer.

But if you looked at blue whales, they’re HUGE.  They have a lot of cells and they can live a long time.  Indeed, according to calculations, half of all blue whales should have colorectal cancer.  By the time they reach middle age, ALL of them should be cancer-ridden.  And that’s only one type of cancer!

However, this is not the case.  Indeed, across all studied species, including humans with our often-poor health choices, cancer occurs at a rate of about 30%.  So mice, with their rapid metabolism and short life spans, get cancer at the same rate as whales, with their much slower metabolism and longer life spans.

This suggests that larger animals have evolved mechanisms against cancer that have held it at the approximately 30% mark – regardless of cell number, age or size, which is contradictory to the current paradigms of cancer as a statistical inevitability.  And if that is so, we would be better off studying how larger animals cope with cancer rather than looking at cancer in mice.

That is not to say that we should suddenly be breeding captive whales for laboratory-style research – but so little is known about the health of these animals in the first place, despite the popularity of sea mammals as aquarium entertainment.  A well sequenced genome would be the first informative step – The authors suggest studying the genome to look at differences in cancer defenses among related species with a wide range of sizes, such as whales and dolphins.  Learning more about their health and biology of these animals may yield interesting new avenues in both human health research and animal veterinary medicine.

Zimmer ends his article eloquently:

“But such an undertaking would have to overcome a lot of inertia in the world of cancer research. Cancer biologists don’t look to big animals as models to study–which is one reason there’s not a single fully-sequenced genome of a whale or a dolphin for scientists to look at. For most cancer researchers, mice are the animals of choice.

But if we want to find inspiration for cancer-fighting medicines, mice are the last animal we’d want to consider. It’s like learning how to play baseball from a bench-cooler at a Little League game, when Willie Mays is waiting to dispense his wisdom.”

Again, find the original article at The Loom.

Read Full Post »