Archives for 2007

In the latest Nature, a group of scientists at Kyoto University claims to have made true embryonic stem cells out of ordinary adult cells by switching off four genes.

In theory, embryonic stem cells can propagate themselves indefinitely and are able to become any type of cell in the body. But so far, the only way to obtain embryonic stem cells involves destroying an embryo, and to get a genetic match for a patient would mean, in effect, cloning that person — all of which raise difficult ethical questions.

[…] Last year, [Shinya] Yamanaka introduced a system that uses mouse fibroblasts, a common cell type that can easily be harvested from skin, instead of eggs4. Four genes, which code for four specific proteins known as transcription factors, are transferred into the cells using retroviruses. The proteins trigger the expression of other genes that lead the cells to become pluripotent, meaning that they could potentially become any of the body’s cells. Yamanaka calls them induced pluripotent stem cells (iPS cells). “It’s easy. There’s no trick, no magic,” says Yamanaka.

The results were met with amazement, along with a good dose of scepticism. Four factors seemed too simple. And although the cells had some characteristics of embryonic cells — they formed colonies, could propagate continuously and could form cancerous growths called teratomas — they lacked others. Introduction of iPS cells into a developing embryo, for example, did not produce a ‘chimaera’ — a mouse carrying a mix of DNA from both the original embryo and the iPS cells throughout its body. “I was not comfortable with the term ‘pluripotent’ last year,” says Hans Schöler, a stem-cell specialist at the Max Planck Institute for Molecular Biomedicine in Münster who is not involved with any of the three articles.

This week, Yamanaka presents a second generation of iPS cells1, which pass all these tests. In addition, a group led by Rudolf Jaenisch2 at the Whitehead Institute for Biomedical Research in Cambridge, Massachusetts, and a collaborative effort3 between Konrad Hochedlinger of the Harvard Stem Cell Institute and Kathrin Plath of the University of California, Los Angeles, used the same four factors and got strikingly similar results.

Assuming that the work translates to humans, which seems likely, the ethical logjam over stem cell research has been definitively broken. Drawing on my own relevant work I can say that the techniques used here are surprisingly simple and easy to translate into a therapy. If so, and plenty of hurdles always lie between proof-of-principle and usable applications, we can soon have a near-endless supply of stem cell lines that carry no more ethical taint than the thousands of ordinary cell lines in common use. Tissue-matching embryonic cells to a patient could prove as simple as a minor skin biopsy. It is not an exaggeration to say that many see the adult-to-stem cell conversion as the Grail of stem cell research.

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Breaking the political logjam could prove as important as the technical advances, although it annoys me immensely that we had one in the first place. Neither scientists, doctors nor sick patients owe any thanks to religious hypocrites and craven politicians who attack stem cell research while giving IVF clinics a pass. More than that, the stem cell issue just helps illustrate the way that the christianist lobby sees human health as a pawn in their ideological agenda. The same activists fought a near-100% effective HPV vaccine because cancer discourages unmarried sex. They primarily support a pointless ban on an abortion procedure because more young women will die of complications. Frankly, pleasing people like that is near the last of my priorities. But if the adult-stem cell conversion technique will advance medical science and also make them go away then consider me doubly pleased.

***Update***

The New York Times report is now online.

Stem Cells Without Embryos?Post + Comments (30)

Credit to the New York Times for adding some perspective to another outside-the-box energy idea, but methinks they miss an important point.

Thanks to the abundance of local droppings, Benson is home to a new $200 million power plant that burns turkey litter to produce electricity. For the last few weeks now, since before generating operations began in mid-May, turkey waste has poured in from nearby farms by the truckload, filling a fuel hall several stories high.

[…] Critics say turkey litter, of all farm animals’ manure, is the most valuable just as it is, useful as a rich, organic fertilizer at a time when demand is growing for all things organic. There is a Web site devoted to detailing the alleged environmental wrongs at the power plant, which detractors consider just another pollutant-spewing, old-technology incinerator dressed up in green clothing.

A related issue is that the electricity is expensive, as called for in a utility contract that led to the plant’s construction, and that it requires a lot of input for a rather small output. Marty Coyne of Platts Emissions Daily, a newsletter that analyzes issues related to the energy markets, said it would take 10 waste-burning plants the size of the one here to equal the energy generated by one medium-size coal-fired plant.

David Morris, vice president of the Institute for Local Self-Reliance, an advocacy group with offices in Minneapolis and Washington, said: “As a matter of public policy, it stinks. The problem is that it’s using a resource in an inefficient way, and required huge subsidies to create a more inferior product than what was already being sold on the market.”

In a sense the inefficiency issue is the least of the problems with burning turkey droppings to make power. Non-renewable energy sources won’t stay cheap forever, so it seems like a perfectly good idea to work out the kinks in whatever renewable sources we can find while power and raw materials are still dirt cheap. When the fuel crunch hits the cost of testing and developing new energy ideas will skyrocket just like everything else. Rather, the problem is that better and more efficient ways to turn droppings into power already exist.

By late this year, Akron hopes to be turning sewage sludge into electricity.

The city and KB Compost Services Inc. began construction in September of a $7 million plant — the first of its kind in the United States — that will rely on bacteria to feed on sludge to produce a gas that can power an electric generator.

The new facility is similar to about 200 plants in Europe and Asia developed by a German company, Schmack Biogas AG.

The basic biogas plant ferments humid organic waste in large anaerobic tanks and puts out rich, sterile fertilizer and methane gas which can be tapped and burned for power. Studies have found that dairy farms can run a power surplus from their own cattle waste without losing the fertilizer benefit, and the system pays for its own startup and maintenance within six years. An even more sensible approach, popular in India, pools the investment in a central plant that collects waste from nearby farms.

For the life of me I will never understand why cities pay good money to import power and to manage waste when the one could help pay for the other. It makes no more sense than the two or three dozen ignored technologies (dear Flagstaff – ever heard of leaky hose irrigation?) which could prolong our time on this blue marble indefinitely.

To illustrate my point, in parts of Colorado the stink from hog farms makes life practically unlivable. North Carolina rivers swell with hog waste on good days and drown in giant floods of the stuff when lagoon dams burst, yet the problem has no need to exist. With a token investment hog farms could have zero waste issues and an electricity bill that pays them money. The same inertia which leads turkey farmers to burn their droppings when they could put out far less CO2 for the same power output and get back good fertilizer works everywhere and every day to ensure that for every ten barrels of oil pumped out of the ground, we piss nine away needlessly.

Alternative Power Plant Is A Double WastePost + Comments (22)