Microsoft Word Kurzweil, Ray The Singularity Is Near doc

Somatic Gene Therapy 
(gene therapy for nonreproductive cells). This is the holy grail of bioengineering, which will 
enable us to effectively change genes inside the nucleus by "infecting" it with new DNA, essentially creating new 
genes.
30
The concept of controlling the genetic makeup of humans is often associated with the idea of influencing new 
generations in the form of "designer babies." But the real promise of gene therapy is to actually change our adult 
genes.
31
These can be designed to either block undesirable disease-encouraging genes or introduce new ones that slow 
down and even reverse aging processes. 
Animal studies that began in the 1970s and 1980s have been responsible for producing a range of transgenic 
animals, such as cattle, chickens, rabbits, and sea urchins. The first attempts at human gene therapy were undertaken in 
1990. The challenge is to transfer therapeutic DNA into target cells that will then be expressed at the right level and at 
the right time. 
Consider the challenge involved in effecting a gene transfer. Viruses are often the vehicle of choice. Long ago 
viruses learned how to deliver their genetic material to human cells and, as a result, cause disease. Researchers now 
simply switch the material a virus unloads into cells by removing its genes and inserting therapeutic ones. Although 
the approach itself is relatively easy, the genes are too large to pass into many types of cells (such as brain cells). The 

---

process is also limited in the length of DNA it can carry, and it may cause an immune response. And precisely where 
the new DNA integrates into the cell's DNA has been a largely uncontrollable process.
32
Physical injection (microinjection) of DNA into cells is possible but prohibitively expensive. Exciting advances 
have recently been made, however, in other means of transfer. For example, liposomes—fatty spheres with a watery 
core—can be used as a "molecular Trojan horse" to deliver genes to brain cells, thereby opening the door to treatment 
of disorders such as Parkinson's and epilepsy.
33
Electric pulses can also be employed to deliver a range of molecules 
(including drug proteins, RNA, and DNA) to cells.
34
Yet another option is to pack DNA into ultratiny "nanoballs" for 
maximum impact.
35
The major hurdle that must be overcome for gene therapy to be applied in humans is proper positioning of a gene 
on a DNA strand and monitoring of the gene's expression. One possible solution is to deliver an imaging reporter gene 
along with the therapeutic gene. The image signals would allow for close supervision of both placement and level of 
expression.
36
Even faced with these obstacles gene therapy is starting to work in human applications. A team led by University 
of Glasgow research doctor Andrew H. Baker has successfully used adenoviruses to "infect" specific organs and even 
specific regions within organs. For example, the group was able to direct gene therapy precisely at the endothelial 
cells, which line the inside of blood vessels. Another approach is being developed by Celera Genomics, a company 
founded by Craig Venter (the head of the private effort to transcribe the human genome). Celera has already 
demonstrated the ability to create synthetic viruses from genetic information and plans to apply these biodesigned 
viruses to gene therapy.
37 
One of the companies I help to direct, United Therapeutics, has begun human trials of delivering DNA into cells 
through the novel mechanism of autologous (the patient's own) stem cells, which are captured from a few vials of their 
blood. DNA that directs the growth of new pulmonary blood vessels is inserted into the stem cell genes, and the cells 
are reinjected into the patient. When the genetically engineered stem cells reach the tiny pulmonary blood vessels near 
the lung's alveoli, they begin to express growth factors for new blood vessels. In animal studies this has safely reversed 
pulmonary hypertension, a fatal and presently incurable disease. Based on the success and safety of these studies, the 
Canadian government gave permission for human tests to commence in early 2005.