Doctors explore use of mismatched heartsTue, 13 Feb 2007 02:26:25 GMTBy LAURAN NEERGAARD, AP Medical Writer WASHINGTON - Connor Geddes was 13 days old when surgeons gave him a new heart that didn't match his blood type — deliberately. Connor, now 11 months old and thriving, is one of several dozen babies around the world to have received mismatched hearts, part of a slowly growing movement to increase these tiniest patients' survival by taking advantage of a lag in their immune systems. Now the nation's transplant network is expanding that effort, saying youngsters may be candidates for an incompatible heart up to age 2. It's the first step in a new push by the United Network for Organ Sharing to decrease the number of children who die awaiting an organ transplant, a toll particularly high for infants and toddlers. "It will not happen overnight," cautioned Dr. Stuart Sweet of Washington University in St. Louis, chairman of UNOS' pediatric transplant committee. But the new heart guidelines "have the potential for significantly impacting the number of patients who die on the waiting list." If the policy sounds counterintuitive, well, it is: Implant a mismatched heart in an adult, and he or she will die rapidly. That happened in 2003, when surgeons in North Carolina accidentally gave a teenager the wrong-type heart and lungs. But babies' immune systems must learn to recognize and attack an organ of a different blood type, a process that's turning out to be more gradual than scientists long thought. Transplant a heart before the baby starts making antibodies that will attack a mismatched organ, and he or she survives as well as babies given matching hearts, says Dr. Lori West, the Canadian surgeon who pioneered incompatible transplants in Toronto in the late 1990s. Those babies still need immune-suppressing drugs for life — blood type is just one form of organ rejection. But given the scarcity of tiny hearts, the mismatch option was good news. In 2005, the last count available, 45 children under age 2 died while awaiting a new heart. As of last month, 74 youngsters under 2 were on the waiting list. About one in 5,000 children are born with a heart defect so bad that they'll need a transplant in the first year or two of life. Yet few babies die of conditions that allow their hearts to be donated. Still, until recently, U.S. transplant centers were reluctant to try mismatched hearts. UNOS began allowing them as a last resort for infants, under age 1, in 2002; only 19 were performed through 2005. The concern: whether children really fare well years after getting a mismatched heart, or if rejection just sets in later. But in the last year — with some of West's initial patients now surviving a decade — that worry is fading. Now the question is who's a good candidate for a mismatched heart, says Dr. Steve Webber, cardiology chief at Children's Hospital of Pittsburgh. "We know we can't do it in adults, but what's the cutoff?" asks Webber. "Nobody knows for sure." Babies begin producing antibodies to different blood types between 5 months and 2 1/2 years of age — it varies widely from child to child, says West, now at the University of Alberta's Stollery Children's Hospital. Only a few of the 90 or so mismatched heart transplants performed worldwide have occurred past a child's first birthday, the oldest in a 30-month-old in Britain. Still, age is just a rough marker for antibody production, West stresses. Blood tests to check antibodies are the real key. Hence the new U.S. policy, adopted last fall and to go into effect later this year. It expands use of mismatched hearts up to age 2, as long as antibody tests show the toddlers are candidates. For now, many transplant centers are like Webber's, trying their first mismatched transplants in babies before working up to toddlers. Last March, Connor Geddes of Erie, Pa., became Pittsburgh's first of five such transplants. His heart's left side was too small to pump. Doctors said Connor wouldn't live long enough to await a heart that matched his Type A blood, but they had a heart from a Type B donor available. "It still amazes me," says Carrie Geddes. "When we talk to people, friends, and tell them, nobody really realizes that can happen." Eleven months later, Connor shows no sign of rejection and happily totters after his older brothers. His tracheotomy tube — from lungs were weakened by heart-pumping machines while he awaited the transplant — is to be removed soon, and the scar on his chest is barely visible. UNOS' Sweet calls the heart policy "a first step in what we really think is a long process in improving wait-list mortality for all children." At a first-of-its-kind meeting March, UNOS will take a hard look at hurdles to improving child organ donation, especially for babies and toddlers. One problem is that when grieving parents consent to a donation, organs aren't always recovered, perhaps because the local transplant center didn't immediately see a good recipient, Sweet says. "It doesn't mean there is no patient suitable for that organ in the whole United States," he says. "There are organs out there that if we find the right recipient, they could be transplanted. Even if it's one at a time, I'm willing to work on that." ___ EDITOR'S NOTE — Lauran Neergaard covers health and medical issues for The Associated Press in Washington. Male sweat can boost arousal in womenTue, 13 Feb 2007 02:26:41 GMTBERKELEY, Calif. - A chemical in male sweat can boost mood, brain activity and sexual arousal in heterosexual women, according to a new study released just in time for Valentine's Day. The study offers the first direct evidence that humans secrete a scent that can affect the physiology of the opposite sex, said researchers at the University of California, Berkeley. Their findings were published this week in The Journal of Neuroscience. "This is the first time anyone has demonstrated that a change in women's hormonal levels is induced by sniffing an identified compound of male sweat," said study leader Claire Wyart, a postdoctoral fellow at UC Berkeley. "There is much more going on than we think when we are smelling body odor." The study conducted last year involved 48 undergraduate women who took 20 sniffs from a bottle containing androstadienone, a compound found in male perspiration and other bodily secretions. The researchers measured the women's levels of the stress hormone cortisol and compared them to the women's responses to a control odor. Cortisol levels in the women rose within about 15 minutes of inhaling the androstadienone scent and remained elevated for more than an hour, UC Berkeley researchers found. They also discovered that blood pressure, heart rate and breathing increased, mood improved and sexual arousal was boosted. While the compound can make women feel more positive and sexually aroused, it's still unclear how it affects their behavior, Wyart said. "Humans are more complex," she said. "You cannot expect them to have stereotypical responses like rodents." HIV patients Marijuana eases foot painTue, 13 Feb 2007 01:36:18 GMTBy PAUL ELIAS, AP Biotechnology Writer SAN FRANCISCO - Smoking marijuana eased http://www.neurology.org British chain sells Valentine Viagra OTCMon, 12 Feb 2007 19:55:31 GMTBy MARIA CHENG, AP Medical Writer LONDON - A gimmick timed for Valentine's Day, or a dangerous medical precedent? Britain's biggest pharmacy chain, Boots, will start selling Viagra over the counter at some stores on Feb. 14 — a day also designated in Britain as National Impotence Day. Doctors are warning of the hazards of making the erectile dysfunction drug freely available to men — especially those with medical conditions such as diabetes or heart problems. "This sets a very bad precedent and should not be condoned," said Dr. Andrew McCullough, a sexual health expert at New York University Medical Center. "This system is basically prescribing medication without doctors." Under the scheme, men age 30 to 65 who want the impotence-fighting drug will have a one-hour consultation with a pharmacist, who will take their medical history and check blood pressure, cholesterol and glucose levels. If no medical red flags are raised, the men can buy four Viagra pills for $97. For a refill, they will have to see a private doctor. "We're increasing access to Viagra for men who may be too embarrassed to talk about it with their general physician," Boots spokeswoman Clare Stafford said Monday. But doctors fear the practice could lead to major health problems being overlooked — and set a bad precedent for other countries. In many cases, sexual dysfunction is an indicator of an underlying disease, such as heart failure or diabetes. Viagra — readily available on the Internet without prescription — was developed by Pfizer Inc. in 1996. It is one of the world's top-selling drugs but is classified as a prescription drug worldwide. Though it is safe and effective, possible rare side effects include vision impairment, heart problems and stroke. Patrons at a London bar were largely sympathetic to the idea of making the drug available without prescription. "It's fair play," said Jason Whelan, 30, who was having a beer with friends. He was quick to say he didn't need the drug — yet. "Come later in life, there's nothing wrong with it," he said. Doctors believe the system might lead patients to believe that a quick pharmaceutical fix is just as effective as seeing a physician. "There is more to solving sex problems than giving men Viagra," said Dr. David Ralph, a consultant urologist at University College London. Ralph said the plan would undermine the potential for physicians to make a comprehensive diagnosis, which might even pick up health problems of the men's sexual partners. "If men can just get Viagra at the pharmacy, we are losing the chance to do proper health screening," he said. In recent years, Boots has introduced similar initiatives with other drugs, such as those for weight loss, hair retention and the morning-after pill. According to the regulations of the European Medicines Agency, which supervises drug use in Europe, Viagra should be available to men only under medical guidance. "Our stance is clear: Viagra is a prescription drug," said Monika Bernstetter, an agency press officer. "But it's up to member states how they implement prescriptions." Boots' pilot program at three Manchester-based branches is expected to last six months. The pharmacy will then consider expanding it to other stores. ___ AP writer Raphael G. Satter in London contributed to this report. |
