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SCIENTISTS WORK ON ANTI-RADIATION VACCINE
Nuclear danger in Japan threatens world public, as the world of science celebrates an important innovation.
Russian scientists developed a vaccine protecting against radiation.
The vaccine, developed by joint work of the Russian Academy of Sciences and NASA, proved to be successful on animals which exposed to the radiation level, with which they could live no longer than seven days.
The anti-raditation vaccine made positive effect also on human cells. A Russian researcher in the project said they succeeded even in the situations where the radiation level was ten thousand times higher than normal.
It may take years to complete some necessary testing and the vaccine is not available for clinical use for the time being.
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HOW MUCH RADIATION IS DANGEROUS?
Here are some facts about radiation and the health dangers it poses:
* Radiation is measured using the unit sievert, which quantifies the amount absorbed by human tissues. One sievert is 1,000 millisieverts and 1 million microsieverts.
* People are constantly exposed to some level of natural radiation. They also get exposed to tiny amounts through sitting in airplanes, routine chest or dental x-rays, and larger amounts through medical tests such as CT-scans and MRIs. A single-organ CT scan, for example, gives a radiation dose of about 6,900 microsieverts.
* On Sunday afternoon, radiation levels in central Tokyo were around 0.16 microsieverts per hour. That is a level experts describe as minimal, and just below the global average of naturally occurring background radiation of 0.17-0.39 per hour, a range given by the World Nuclear Association. It is also significantly lower than the cosmic radiation of up to 7 microsieverts per hour experienced on a Tokyo-New York flight.
Below are different levels of massive radiation exposure in a single dose -- all measured in millisieverts -- and their likely effects on humans, as published by the U.S. Environmental Protection Agency:
- 50-100: changes in blood chemistry
- 500: nausea, within hours
- 700: vomiting
- 750: hair loss, within 2-3 weeks
- 900: diarrhea
- 1,000: hemorrhage
- 4,000: possible death within 2 months, if no treatment
- 10,000: destruction of intestinal lining, internal bleeding and death within 1-2 weeks
- 20,000: damage to the central nervous system and loss of consciousness within minutes, and death within hours or days
Sources: Reuters, Taiwan Atomic Energy Council, World Nuclear Association, US Department of Transportation, US Environmental Protection Agency
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Radiats Biol Radioecol. 2007 May-Jun;47(3):286-91.
Mechanisms of action for an anti-radiation vaccine in reducing the biological impact of high dose and dose-rate, low-linear energy transfer radiation exposure.
Maliev V, Popov D, Casey RC, Jones JA.
Vladicaucasian Scientific Center, Russian Academy of Sciences, Biotechnology Departament, Russia.
Abstract
The development of an anti-radiation vaccine could be very useful in reducing acute radiation syndromes. Existing principles for the treatment of acute radiation syndromes are based on the amelioration of progressive pathophysiological changes, using the concept of replacement therapy. Active immunization by small quantities of the essential radiation-induced systemic toxins of what we call the Specific Radiation Determinant (SRD) before irradiation increased duration of life among animals that were irradiated by lethal or sub-lethal doses of gamma-radiation. The SRD toxins possess antigenic properties that are specific to different forms of acute radiation sickness. Intramuscular injection of larger quantities of the SRD toxins induce signs and symptoms in irradiated naive animals similar to those observed in acute radiation syndromes, including death. Providing passive immunization, at variable periods of time following radiation, with preparations of immune-globulins directed at the SRD molecules, can confer some protection in the development of clinical sequelae in irradiated animals. Improved survival rates and times were observed in animals that received lower, sublethal doses of the same SRDs prior to irradiation. Therefore, active immunization can be induced by SRD molecules as a prophylaxis. The protective effects of the immunization begin to manifest 15-35 days after an injection of a biologically active SDR preparation. The SRD molecules are a group of radiation toxins with antigenic properties that correlate specifically with different forms of radiation disease. The SRD molecules are composed of glycoproteins and lipoproteins that accumulate in the lymphatic system of mammals in the first hours after irradiation, and preliminary analysis suggests that they may originate from cellular membrane components. The molecular weight of the SRD group ranges from 200-250 kDa. The SRD molecules were isolated from the lymphatic systems of laboratory animals that were irradiated with doses known to induce the development of cerebral (SRD-1), non-specific toxic effects (SRD-2), gastrointestinal (SRD-3) and hematological (bone marrow) (SRD-4) syndromes. Our results suggest that an anti-radiation vaccine can be developed for prophylactic use against radiation damage induced by acute exposure to significant doses of low Linear Energy Transfer (LET) radiation for humans, including nuclear power workers, commercial and military pilots, cosmonauts/astronauts, nuclear-powered engine vessel operators and possibly even the civilian population in the case of a nuclear terrorism event.
PMID: 17867496 [PubMed - indexed for MEDLINE]
