Designing cells to deliver drugs
Article Abstract:
Gene therapy is a relatively new branch of medical science; its goal is to cure disease by repairing defective genes. Genetic diseases are caused by an abnormality of a gene that directs the production of an essential substance in the body; a gene may be thought of as a blueprint for the manufacture of an important protein. For example, children who lack the correct gene to make adenosine deaminase have ineffective immune systems; adenosine deaminase is required by the lymphocytes responsible for immune function. The strategy that gene therapists hope to use is to isolate and clone (reproduce) the healthy gene and then to introduce the clone into the patient with the genetic disease. The correct gene could be inserted into the stem cells, important parent blood cells from which the red and white blood cells descend. The correction would be passed down to future generations of blood cells and would cure the patient. However, scientists are having great difficulty obtaining the scarce stem cells which they had hoped would facilitate this gene therapy. While these technical hurdles are being addressed, researchers are seeking other genetic engineering techniques for curing disease. The focus has been temporarily moved from repairing the patient's own gene to trying to stimulate certain body cells to manufacture the proteins lacking with a particular disease. The special cells would produce and then deliver "genetic drugs" in the body. This technology could treat a wide variety of illnesses and is not limited to genetic diseases. The genetic drug delivery system could carry antitumor agents to cancerous growths or deliver a steady dose of soluble CD4, a protein that blocks the AIDS (acquired immunodeficiency syndrome) virus. Unfortunately, experiments in the field of human gene therapy face stringent regulations and reviews before they are approved; to date, only one such project has been launched. (Consumer Summary produced by Reliance Medical Information, Inc.)
Publication Name: Science
Subject: Science and technology
ISSN: 0036-8075
Year: 1989
User Contributions:
Comment about this article or add new information about this topic:
Gore Tex organoids and genetic drugs
Article Abstract:
Scientists are in the early stages of developing artificial organs called organoids, which they hope will deliver drugs within the human body. The first organoid has been implanted into a rat's abdomen and is acting as an extra liver. The artificial liver is growing blood vessels that extend into the rat's own liver and connect the two organs; blood supply to the organoid is essential to its function. Surprisingly, the organoid is made up of angel-hair Gore-Tex, a tough synthetic fiber, and two natural substances. These substances are collagen, a fibrous protein found in connective tissues such as ligaments, and heparin-binding growth factor-1, which stimulates the growth of blood vessels. Since the organoid and natural liver are linked by a network of blood vessels, drugs or other substances needed by the patient can be delivered from the organoid into the body. One major goal of the application of this new technology is to supply CD4 to AIDS (acquired immunodeficiency syndrome) patients; CD4 is a protein that prevents the AIDS virus from infecting body cells. The advantage of this drug delivery system over the usual means of administering drugs is that the organoid can supply a continuous, steady dose of medication. These experiments are part of a new branch of medical research called gene therapy. The drugs to be delivered by the organoids will be genetically engineered substances; the organoid cells will contain genes that direct the manufacture of proteins the patient needs to fight or cure the illness. (Consumer Summary produced by Reliance Medical Information, Inc.)
Publication Name: Science
Subject: Science and technology
ISSN: 0036-8075
Year: 1989
User Contributions:
Comment about this article or add new information about this topic:
A genetic shield to prevent emphysema?
Article Abstract:
Many people with emphysema, a chronic lung disease, lack a particular protein that protects the lining of the respiratory tract. Because they lack this protein, alpha-1 antitrypsin, the delicate membranes lining the lungs are vulnerable to attack by a natural substance, neutrophil elastase. Most people have enough alpha-1 antitrypsin to counteract the destructive properties of neutrophil elastase. But with the alpha-1 antitrypsin deficiency of emphysema, lung tissue becomes riddled with small holes that eventually make breathing impossible. Patients with emphysema caused by alpha-1 antitrypsin deficiency experience deteriorating pulmonary function which progressively deprives body organs of needed oxygen; patients rarely live beyond the age of 60. To protect their lungs, these individuals need the gene that directs the manufacture of alpha-1 antitrypsin; genes contain the blueprint for production of essential proteins. Patients with this disorder generally have a mutated (defective) gene that suppresses alpha-1 antitrypsin production. Researchers hope to put the normal gene into an aerosol medication which patients could spray into their lungs. The correct gene would be carried in the aerosol spray by T lymphocytes (cells from the immune system). This technique has been successful in mice. Because of these advances, this type of emphysema may be one of the first diseases to be cured by human gene therapy. (Consumer Summary produced by Reliance Medical Information, Inc.)
Publication Name: Science
Subject: Science and technology
ISSN: 0036-8075
Year: 1989
User Contributions:
Comment about this article or add new information about this topic:
- Abstracts: Sweeping court decision could crush smog plans, rein in TRI and wetlands rules. U.K. businesses propose greenhouse gas emissions trading scheme
- Abstracts: Field guide to the new biology lab. Great books and city crops. Sun-stains
- Abstracts: Follow the mercury. Green chemistry: Progress and challenges
- Abstracts: Superimposing ultrasonic waves on the dies in tube and wire drawing. Optimal blank design of arbitrary shapes by the sensitivity method
- Abstracts: AIDS drug trials enter new age. New AIDS drugs take careful aim. Trials and tribulations of AIDS drug testing