Organ shortage.

Fourteen-year-old Sean McCallum lay in a hospital bed waiting for a new heart. A virus had severely weakened his own heart. Without a transplant, Sean would die.

Sean's case is not unusual. Every day seven people die while waiting for organ transplants, says Esther Benenson of the United Network for Organ Sharing. The problem, says Ramesh Kumar of Nextran, a genetic-engineering company developing new transplant techniques, is that "there just aren't enough human organs to go around."

Now Kumar and other scientists say they've found a solution: Alter the genetic makeup of certain animals so their organs can be transplanted into humans. With this gene-altering technique, Kumar says "we may be using pig hearts for transplants by the year 2000."

That prospect has stirred up controversy among "animal-rights" activists. Should the research go forward? Read on, then debate and decide.

SHORT SUPPLY

Last year, organ transplants saved 16,000 American lives, says Last Swasey, education coordinator for the New York Regional Transplant Program. But thousands more people died because of a severe organ shortage.

The problem: To get an organ for transplant, you have to wait for someone with a healthy organ to die. "Ninety-five percent of transplant organs come from people who die from head injuries - from a car accident or shooting," says Swasey.

Many people don't consider donating their organs, or they don't let loved ones know they are willing. And surviving relatives must give consent for organ donation - often not the first thing on their minds after an unexpected death in the family. By using animal organs instead, says Kumar, "thousands of lives could be saved."

ALTERED ORGANS

Transplanting animal organs into humans is not as simple as it sounds. For one thing, the human immune system doesn't react well to "foreign" body parts, those with a different genetic makeup. Our immune systems sometimes even reject organs from other, unrelated humans.

When immune cells recognize the tissues that make up these body parts as different, they produce proteins that attack and eventually destroy the foreign tissue - just like they would destroy a germ. Because animals like pigs are quite different from humans, their organs would probably trigger a very strong immune rejection.

That's why scientists are working to make animal organs more acceptable to the human body. How? By changing the animals' genes.

Last June, scientists at Duke University genetically altered a pig's heart. "We injected human DNA [genes] into the cells of a fetal pig," says Dr. Jeffrey Platt, one of the researchers. The DNA snippet contains information that identifies the pig's organs as "human" instead of "pig," says Platt. This way, there will be less chance of a human's immune system rejecting the pig's organs if they're used for transplants when the pig is born.

So far, scientists have transplanted pig hearts with human genes into mice and baboons. They say the results of these preliminary tests in animals have been promising. They still have a lot of work to do, however, before testing these transgenic (from two species) organs in humans.

ANIMAL OUTRAGE

But animal-rights activists say the whole idea of using animal organs, particularly the current genetic research, is cruel and unjust.

"Animals don't exist as tools for human beings, or [for] replacement parts," Brebner of PETA (People for the Ethical Treatment of Animals). Brebner is opposed to anything that violates the basic nature of animals - especially changing their genes.

Others believe transplanting animal organs into humans is drastic and unnecessary. "Millions spent on breeding cows and pigs for their organs could be better spent on health education and prevention programs," says Andrew Kimbrell, author of The Human Body Shop: The Engineering and Marketing of Life, a book that criticizes the new technology. Seventy-five percent of the heart and liver disease cases that lead to a need for organ transplant are preventable, says Kimbrell. The key, he says, is to convince people to eat healthfully, and not to smoke or drink alcohol. Scientists could also use research funds to improve the efficiency and reliability of artificial organs.

Though new inventions and prevention programs may help, transplant educator Larry Swasey believes that spending money to encourage more people to donate their organs is an even better idea. "Each year we lose 50,000 to 80,000 organs because doctors don't notify us about deaths, or because families say no," says Swasey, who had a heart transplant seven years ago. "If we educated enough people [about organ donations], we could take everyone who needed an organ off the waiting list in a year."

Sean McCallum, now 18, was one of the lucky ones. He got off the list when he received a human heart. But he says he wouldn't care if his new heart had come from another species. "As long as it worked as well as a human's," he says, "I wouldn't have a problem with it."

What do you think?

Should other

species' organs

be transplanted

into humans?

YES "If the animals are treated properly and people don't mind having animal parts inside them." Sekena Price Age 18 Bronx, NY

NO "You're trying to save one life while taking away another." Randy Navarrette Age 14 Escondido, CA

YES "Only if [the organ transplant] had a chance of really prolonging the human's life, not just extending it for a short while." Clint Dunn Age 14 Itta Bena, MS

NO "The animal will definitely die and it's uncertain if the human will live." Jamie Desena Age 13 Wellington, FL