Using immunity to block conception
Article Abstract:
Scientists have been trying to develop a vaccine against eggs or sperm that could be used as a long-term type of contraception. If antibodies are made against and react with the egg or sperm, fertilization would not be able to occur. The studies have been difficult because it is not known what proteins on the egg or sperm should be used to stimulate the immune system to produce antibodies. Problems have also existed concerning the development of an autoimmune response, in which the immune system reacts against the body, which can lead to a diseased state. However, it is now predicted that this type of vaccine could be available by the year 2000. The problem with autoimmunity has been overcome by immunizing females against sperm. Using guinea pigs as a animal model, female animals immunized against sperm have been rendered infertile for up to 18 months. The same type of study will begin in baboons and then, with the Food and Drug Administration's approval, trials can begin in humans. Other researchers have selected certain proteins on the egg that do not cause an autoimmune response, which could lead to vaccination involving eggs. Although such a vaccine would result in long-term contraception, the process is considered reversible, as the antibody levels would eventually - between two and five years - decrease to levels that would no longer be effective. In Australia, a trial is being conducted of a vaccine against a hormone necessary for the implantation of the fertilized egg in the uterus. However, because the egg is already fertilized, this vaccine is considered an abortive procedure, making its use controversial in the United States. (Consumer Summary produced by Reliance Medical Information, Inc.)
Publication Name: Science
Subject: Science and technology
ISSN: 0036-8075
Year: 1991
User Contributions:
Comment about this article or add new information about this topic:
Making plants aluminum tolerant
Article Abstract:
Researchers in Mexico are using genetic engineering to develop crops that tolerate soils with high aluminum content. A gene for aluminum tolerance would be especially beneficial in developing countries in the tropics, which have acidic soils with soluble aluminum.
Publication Name: Science
Subject: Science and technology
ISSN: 0036-8075
Year: 1997
User Contributions:
Comment about this article or add new information about this topic:
Designing therapies that target tumor blood vessels
Article Abstract:
Several new potential cancer therapies aim to cut off the blood flow to cancerous tumors. One therapy attempts to prevent tumors from growing blood vessels to begin with, while the other attempts to block blood vessels to the tumor that have already grown.
Publication Name: Science
Subject: Science and technology
ISSN: 0036-8075
Year: 1997
User Contributions:
Comment about this article or add new information about this topic:
- Abstracts: Innovative immunity: a biological trick offers a promise for making vaccines from RNA. Gene therapy setback: a tragic death clouds the future of an innovative treatment method
- Abstracts: Quantum teleportation. Quantum seeing in the dark. A do-it-yourself quantum eraser
- Abstracts: Monitoring Earth's vital signs. Methane, plants and climate change. The physical science behind climate change
- Abstracts: Tapping the code; encryption. 24 hours in space. Arsenal of the sun
- Abstracts: Pressure to change. In the land of the dreamtime. Side splitting; jokes, ice water and magnetism can change your view of the world - literally