More Than Human: Embracing The Promise Of Biological Enhancement - Hardcover

Naam, Ramez

 
9780767918435: More Than Human: Embracing The Promise Of Biological Enhancement
Hardcover
ISBN 10: 0767918436 ISBN 13: 9780767918435
Verlag: Doubleday, 2005

Inhaltsangabe

A thought-provoking study of the integration of the fields of biology and technology examines the cutting-edge breakthroughs that can transform the human race, analyzing the ethical dilemmas posed by twenty-first-century science and celebrating the potential of these controversial technologies. 25,000 first printing.

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Über die Autorin bzw. den Autor

RAMEZ NAAM helped develop two of the most widely used pieces of software in the world—Microsoft Internet Explorer and Microsoft Outlook. He serves as an advisor to several technology associations and speaks frequently at technology and futures conferences. He lives in Seattle.

Aus dem Klappentext

A man, blind for twenty years, can see when he puts on a pair of glasses connected to electrodes in his brain.
Gene therapy allows a young woman born with "bubble boy" disease to live normally among her peers.
Life-extension techniques promise to increase human life span by forty years or more.


It sounds like the stuff of science fiction, but these are true phenomena that have recently become hot topics in mainstream media. But while technology is enhancing the lives of many, it has also created a host of controversial capabilities, ranging from cloning to genetic engineering.

Distilling the most cutting-edge achievements being made in labs around the world, BETTER THAN HUMAN offers an exciting tour of the way technology is impacting our lives. Throughout this remarkable trip, Ramez Naam shares an impassioned vision for the future, with revealing insight into the ethical dilemmas posed by twenty-first-century science. Encouraging us to celebrate rather than fear these innovations, his powerful book separates fact from myth with elegant lucidity, arguing that these controversial technologies have the power to transform the human race for the better.

BETTER THAN HUMAN offers much-needed wisdom in the raging debates between technophobes and technophiles, and everyone else seeking to understand the marvelous possibilities that arise when mind meets machine.

Auszug. © Genehmigter Nachdruck. Alle Rechte vorbehalten.

CHAPTER 1
Choosing
Our
Bodies


In 1989, Raj and Van DeSilva were desperate. Their daughter Ashanti, just four, was dying. She was born with a crippled immune system, a consequence of a problem in her genes.

Every human being has around thirty thousand genes. In fact, we have two copies of each of those genes--one inherited from our mother, the other from our father. Our genes tell our cells what proteins to make, and when.
Each protein is a tiny molecular machine. Every cell in your body is built out of millions of these little machines, working together in precise ways. Proteins break down food, ferry energy to the right places, and form scaffoldings that maintain cell health and structure. Some proteins synthesize messenger molecules to pass signals in the brain, and other proteins form receptors to receive those signals. Even the machines inside each of your cells that build new proteins—called ribosomes—are themselves made up of other proteins.

Ashanti DeSilva inherited two broken copies of the gene that contains the instructions for manufacturing a protein called adenoside deaminase (ADA). If she had had just one broken copy, she would have been fine. The other copy of the gene would have made up the difference. With two broken copies, her body didn’t have the right instructions to manufacture ADA at all.

ADA plays a crucial role in our resistance to disease. Without it, special white blood cells called T cells die off. Without T cells, ADA-deficient children are wide open to the attacks of viruses and bacteria. These children have what’s called severe combined immune deficiency (SCID) disorder, more commonly known as bubble boy disease.

To a person with a weak immune system, the outside world is threatening. Everyone you touch, share a glass with, or share the same air with is a potential source of dangerous pathogens. Lacking the ability to defend herself, Ashanti was largely confined to her home.

The standard treatment for ADA deficiency is frequent injections of PEG-ADA, a synthetic form of the ADA enzyme. PEG-ADA can mean the difference between life and death for an ADA-deficient child. Unfortunately, although it usually produces a rapid improvement when first used, children tend to respond less and less to the drug each time they receive a dose. Ashanti DeSilva started receiving PEG-ADA injections at the age of two, and initially she responded well. Her T-cell count rose sharply and she developed some resistance to disease. But by the age of four, she was slipping away, no longer responding strongly to her injections. If she was to live, she’d need something more than PEG-ADA. The only other option at the time, a bone-marrow transplant, was ruled out by the lack of matching donors.

In early 1990, while Ashanti’s parents were searching frantically for help, French Anderson, a geneticist at the National Institutes of Health, was seeking permission to perform the first gene-therapy trials on humans. Anderson, an intense fifth-degree blackbelt in tae kwon do and respected researcher in the field of genetics, wanted to show that he could treat genetic diseases caused by faulty copies of genes by inserting new, working copies of the same gene.

Scientists had already shown that it was possible to insert new genes into plants and animals. Genetic engineering got its start in 1972, when geneticists Stanley Cohen and Herbert Boyer first met at a scientific conference in Hawaii on plasmids, small circular loops of extra chromosomal DNA in which bacteria carry their genes. Cohen, then a professor at Stanford, had been working on ways to insert new plasmids into bacteria. Researchers in Boyer’s lab at the University of California in San Francisco had recently discovered restriction enzymes, molecular tools that could be used to slice and dice DNA at specific points.

Over hot pastrami and corned-beef sandwiches, the two Californian researchers concluded that their technologies complemented one another. Boyer’s restriction enzymes could isolate specific genes, and Cohen’s techniques could then deliver them to bacteria. Using both techniques researchers could alter the genes of bacteria. In 1973, just four months after meeting each other, Cohen and Boyer inserted a new gene into the Escherichia coli bacterium (a regular resident of the human intestine).

For the first time, humans were tinkering directly with the genes of another species. The field of genetic engineering was born. Boyer would go on to found Genentech, the world’s first biotechnology company. Cohen would go on to win the Nobel Prize in 1986 for his work on cell growth factors.

Building on Cohen and Boyer’s work with bacteria, hundreds of scientists went on to find ways to insert new genes into plants and animals. The hard work of genetically engineering these higher organisms lies in getting the new gene into the cells. To do this, one needs a gene vector—a way to get the gene to the right place. Most researchers use gene vectors provided by nature: viruses. In some ways, viruses are an ideal tool for ferrying genes into a cell, because penetrating cell walls is already one of their main abilities. Viruses are cellular parasites. Unlike plant or animal cells, or even bacteria, viruses can’t reproduce themselves. Instead, they penetrate cells and implant their viral genes; these genes then instruct the cell to make more of the virus, one protein at a time.

Early genetic engineers realized that they could use viruses to deliver whatever genes they wanted. Instead of delivering the genes to create more virus, a virus could be modified to deliver a different gene chosen by a scientist. Modified viruses were pressed into service as genetic “trucks,” carrying a payload of genes loaded onto them by researchers; these viruses don’t spread from cell to cell, because they don’t carry the genes necessary for the cell to make new copies of the virus.

By the late 1980s, researchers had used this technique to alter the genes of dozens of species of plants and animals—tobacco plants that glow, tomatoes that could survive freezing, corn resistant to pesticides. French Anderson and his colleagues reasoned that one could do the same in a human being. Given a patient who lacked a gene crucial to health, one ought to be able to give that person copies of the missing gene. This is what Anderson proposed to do for Ashanti.

Starting in June of 1988, Anderson’s proposed clinical protocols, or treatment plans, went through intense scrutiny and generated more than a little hostility. His first protocol was reviewed by both the National Institutes of Health (NIH) and the Food and Drug Administration (FDA). Over a period of seven months, seven regulatory committees conducted fifteen meetings and twenty hours of public hearings to assess the proposal.

In early 1990, Anderson and his collaborators received the final approval from the NIH’s Recombinant DNA Advisory Committee and had cleared all legal hurdles. By spring, they had identified Ashanti as a potential patient. Would her parents consent to an experimental treatment? Of course there were risks to the therapy, yet without it Ashanti would face a life of seclusion and probably death in the next few years. Given these odds, her parents opted to try the therapy. As Raj DeSilva told the Houston Chronicle, “What choice did we have?”

Ashanti and her parents flew to the NIH Clinical Center at Bethesda, Maryland. There, over the course of twelve days, Anderson and his colleagues Michael Blaese and Kenneth Culver slowly extracted some of Ashanti’s blood cells. Safely outside the body, the cells had new, working copies of the ADA gene inserted into them by a hollowed-out virus. Finally,...

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Verlag
Doubleday
Erscheinungsdatum
2005
Sprache
Englisch
ISBN 10 
0767918436
ISBN 13 
9780767918435
Einband
Gebundene Ausgabe
Auflage
1
Anzahl der Seiten
276
Kontakt zum Hersteller
Nicht verfügbar
Verantwortliche Person
Nicht verfügbar

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