Growing new limbs in birds and people.

Growing new limbs in birds and people.

Growing new limbs in birds and people.

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Science, technology, and life.
Nov. 22 2006 7:43 AM

Chickenstein

Growing new limbs in birds and people.

(For the latest Human Nature columns on cybersex, Rush Limbaugh, and biotech politics, click here.)

Scientists chopped off part of a chick embryo's wing and grew it back. They did it by boosting production of proteins that spur limb growth. Frogs and salamanders can regrow limbs, but until now, we thought chickens couldn't. Theory: Evolution has turned off the ability to regrow limbs in many species, but the ability's still there, if we can figure out how to tweak the genes. Happy spin: By tweaking cells from your arm stump, we can turn them into stem cells and regrow your arm. Horror spin: There's a reason why evolution turned off these genes: Cells from some chicks in the experiment became cancerous, and other chicks "sprouted several appendages." (WSJ link requires subscription.) (For previous updates on growing livers, bladders, and meat in labs, click here, here, and here.)

William Saletan William Saletan

Will Saletan writes about politics, science, technology, and other stuff for Slate. He’s the author of Bearing Right.

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An executive embezzled $1.8 million and successfully blamed the crime on Paxil. Prosecutors asked for a jail sentence of at least three and a half years, but defense lawyers presented studies and expert testimony to show that Paxil can cause people with bipolar disorder to behave uncontrollably. A federal judge sentenced the defendant to one year of home detention with five years of probation. Compassionate view: It says on the Paxil box that such drugs can impair your judgment. Cynical view: No more Paxil for judges. (For Human Nature's takes on alcohol as a defense in the Mark Foley case, click here and here. For a previous update on Patrick Kennedy blaming his car crash on Ambien, click here.)

Government agencies want an alcohol sensor in every car. First stage: "Ignition interlock" devices (which prevent the car from starting if the driver flunks a breath test) for anyone convicted of drunk driving. Next stage: Passive sensors for everyone. Current devices include an ignition-blocking keychain Breathalyzer and a gizmo that sends light through your skin and measures the refraction. Future devices will monitor "involuntary eye movements and eye closure that can indicate drowsiness." Rationales: 1) This will save lives. 2) License suspensions and jail threats have failed. 3) The public supports it. 4) We can do this voluntarily, e.g., by offering insurance discounts for cars with sensors. 1) Charging higher premiums if you refuse a sensor is not voluntary. 2) The public also supports trading the Bill of Rights for $20,000. 3) If you're drunk, just get your sober buddy to blow into the Breathalyzer and away you go. (For previous updates on alcohol inhalers and arrests for drinking in bars, click here and here. For Human Nature's takes on alcoholism as a criminal defense, click here and here.)

Iowa is promoting deer hunting to feed people. Problem 1: Exploding deer population destroyed crops and caused car accidents. Problem 2: More families had trouble buying food. Solution: The state allows more deer hunting, charges an extra fee for the licenses, and uses the money to process the meat for human consumption. Deer donations to food banks have tripled to a quarter of a million pounds of venison. Sample participants: Sportsmen Against Hunger, Farmers and Hunters Feeding the Hungry. Rationales: 1) It's good conservation. 2) It's good sportsmanship. 3) It's cheaper than buying beef. 4) When you see a hungry person with deer meat, you've "just looked into the eyes of Jesus." Rebuttal: So has the deer. (WSJ link requires subscription.) (For Human Nature's takes on hunting and eating animals, click here and here.)

The FDA lifted its ban on cosmetic silicone breast implants, but only if you're 22 or older. Until now, anyone could get saline implants, but silicone was allowed only for reconstruction after mastectomy or injury. Official rationale for lifting the ban: Studies show "no convincing evidence that breast implants are associated" with cancer or other diseases. Unofficial rationale: Yeah, they might leak, but the technology's improving, and what the hell, silicone looks and feels more like the real thing. (Rationale for the age restriction: You shouldn't get implants till your breasts are fully developed.) Critique: Corporations 1, safety 0. Defense: If women think the natural look is worth MRI's, leakage, and follow-up surgery, who are we to say no? (For previous updates on teen breast implants and breast piercing, click here and here.)

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China admitted it gets most of its transplant organs from executed prisoners. According to Amnesty International, China carried out more than 80 percent of last year's executions worldwide. Two weeks ago, the government announced judicial reforms that would sharply reduce executions; surgeons worry this will cut off the country's organ supply. China also admitted many organs are sold to foreigners who pay big bucks to jump the long line of Chinese waiting for organs. Government's spins: 1) We're coming clean about these practices so we can change them. 2) We've already banned organ sales. Critics' rebuttals: 1) The government's coming clean because the facts got out despite its censorship. 2) The ban on sales doesn't cover military and police hospitals, where prisoners' organs are most likely to show up. (For previous updates on organs from Chinese prisoners, click here and here.)

Resveratrol doubles endurance in mice. This is the same stuff that neutralized the bad consequences of fatty food in a recent mouse study (extending the lives of fat-eating mice by 15 percent). In the new study, resveratrol-fed mice built more energy capacity and athletic muscle, burned more fat, and lowered their weight and their heart rates. Genetic evidence suggests this or related drugs might similarly help humans. One company says demand for its resveratrol pills has multiplied by 2,400 in the two weeks since the previous resveratrol study came out. Skeptics' warnings: 1) We don't know whether this will work in humans. 2) To get a dosage equivalent to what the mice got, you'd need way more resveratrol than you could get from today's pills, much less from red wine. 3) We don't know whether such a dosage is safe in humans. 4) If it works, athletes may use it to cheat. Researchers' rejoinders: 1) Of course they'll use it, and we're using it already, since it "makes you look like a trained athlete without the training." 2) "This is the first example of a drug that can apparently affect the whole aging process." 3) If it's unsafe or ineffective in humans, we know how to find similar drugs that will work for us. (For the most recent update on resveratrol, click here. For Human Nature's takes on athletic enhancement, click here and here. For life extension, click here.)

A new robot can recognize when it's injured and change its behavior to compensate. Animals do this all the time, but previous robots have shown little or no adaptability. This robot was designed to observe the consequences of its movements, infer how its limbs work, and adjust when the consequences change. Key test: When its creators shortened one of its legs, it changed the way it walked. Sci-fi spin: It's self-aware! Realistic spin: It's self-modifying. Upbeat spin: It's an early model for explorer robots that must handle surprises on other planets without human aid. Nightmare scenario 1: Adaptive, self-modifying robots will treat human interference as just another challenge to overcome. Scientists' rejoinder: "We just pull the plug out of the robot." Nightmare scenario 2: Your plug-pulling habit is just another challenge. (For Human Nature's take on remote-controlled killing, click here. For automated polling, click here.)

A High Court judge ruled that Ireland's constitutional "right to life of the unborn" doesn't apply to frozen embryos. Context: A woman petitioned to implant IVF embryos conceived with her husband, who has since separated from her and doesn't want them implanted. Ruling: "There has been no evidence ... to establish that it was ever in the mind of the people voting on the Eighth Amendment to the Constitution that 'unborn' meant anything other than a fetus or child within the womb." Therefore, if you want to guarantee embryos a right to life, pass a law. Irish health minister's reaction: This may affect how we regulate IVF. Catholic archbishop's reaction: "Human life must be respected and protected absolutely from the moment of conception." American rejoinder: Welcome to judicial restraint, pro-lifers. (For Human Nature's takes on IVF embryo rights in the United States and Italy, click here and here.)

A British bioethics council opposes routine lifesaving care for babies gestated less than 22 weeks. The influential Nuffield Council on Bioethics says intensive care for such babies should require a parental request and doctors' approval, since survivors at this gestational age are "extremely rare" and often have grave disabilities. But the council also opposes affirmative steps to kill the babies. Council's  rationale: "We don't think it is always right to put a baby through the stress and pain of invasive treatment if the baby is unlikely to get better and death is inevitable." Pro-lifers' reaction: This is "eugenics" and "a further step towards active killing of disabled newborns." Catholic bishops' reaction: 1) It's OK to "withdraw medical treatment when it is judged to be futile or unduly burdensome." 2) The council rightly "reaffirms the validity of existing law prohibiting euthanasia, and upholds the vital and fundamental moral principle that the deliberate taking of innocent human life is always gravely wrong." British Medical Association's reaction: Every case is different, so we don't like drawing a universal line at 22 weeks. (For Human Nature's take on late-term fetal pain, click here. For previous updates on preemies, click here, here, and here.)

Latest Human Nature columns: 1) The mortal combat of biotech politics. 2) Rush Limbaugh's reality problem. 3) Pills, booze, and Mark Foley's abuser. 4) The perils of policing cybersex. 5) Pro-lifers against contraception. 6) The first penis transplant. 7) Is eugenics better than sex? 8)  Buried alive in your own skull. 9) The global explosion of fat.