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Cure For Radiation Sickness Found?
Summit writes "A scientist has claimed to have discovered a radioprotectant that all but eliminates acute radiation sickness even in cases of lethal doses of radiation in tests on rats and monkeys, when injected up to 72 hours after exposure. They also claim the drug, a protein, has no observed negative effects in humans. They have not irradiated any people just yet, but if this turns out to be true, it could mean everything from curing cancer to making manned interplanetary space expeditions feasible... not to mention treatment for radiation exposures in nuclear/radiological accidents/attacks. If this drug works, it would mean a true breakthrough as past experiments with radioprotectants were not particularly promising in any respect." The only source for the story at this time is an exclusive in YNet News, a site with the subtitle "Israel At Your Fingertips." Such a radioprotectant would be huge news for Israel. Make of it what you will.
There's more information on Medical News today if anyone wants a more medical take on this and a less ... Israeli interpretation (I don't know about you but I'm not too hung up on what nationality the researchers are and am more so interested in the technical details). Their 2008 annual report sheds a lot of insight on this as well. Although this information has been public knowledge since the beginning of the year, it should be interesting to watch their stock fluctuate throughout today.
My work here is dung.
So this can patch you DNA back together after it's been ripped to shreds?
Pardon me, but I'm a bit sceptical.
"The medication works by suppressing the "suicide mechanism" of cells hit by radiation, while enabling them to recover from the radiation-induced damages that prompted them to activate the suicide mechanism in the first place."
So it turns the cell into a cry for attention?
Seriously though, saving cells damaged by radiation sounds like a shortcut to cancer. Is the claim of 'enabling cells to recover' realistic?
Is that the stuff Helo kept shooting up while he was stranded on Caprica?
No it won't. The damaged is caused by radiation which destroys DNA. Radioactive particles that are helium or larger are stopped by your skin. Smaller particles ionize organic molecules within your body producing highly reactive radicals. Maybe its these radicals you call energetic particles? Anyway even if you remove them the DNA damage from the radiation is still there, and often the extent of the radical damage is beyond the coping mechanism of the cell. Acute damage is in the radiation, radical damage is the slow damage of aging.
Like the GP said, the methods of radiation damage are diverse, it is impossible for there to exist a single pill that treats it from all these aspects. The pill would need to be a cluster of several different types of DNA repair enzymes (to repair DNA damage from all the possible ways of bond damage), as well as being an antioxidant (to absorb radicals) and some sort of protein 'digestant' (to remove the denatured proteins). Since the body took 3+ billion years to come up a couple dozen enzymes to fulfill these purposes, it seem unlikely (downright impossible!) that a single molecule could be created to take their place.
it will just prolong their life and alter the proximal cause of death from radiation sickness to (most likely) a flood of lymphomas.
Assuming they aren't lying about their animal models, this is not the case, nor would one expect it to be.
Apoptosis is a programmed response to generic cellular damage (amongst other things.)
We evolved in a low radiation environment, so there was no selection for more clever apoptosis triggers than, "lots of damage, time to die!" Because such a mechanism would only kill off a cell needlessly now and then, it posed no risk. It was, like so many evolved solutions to problems, good enough.
Unfortunately this generic and rather indiscriminate mechanism is not appropriate to the rare and artificial case of high radiation exposure, in which many cells sustain lots of damage, but most of it reparable. Under these circumstances, turning off apoptosis and letting the expensive machinery of cellular and genetic repair do its thing is more desirable.
It is still likely that there is an elevated long-term risk of cancer comparable to that from high non-lethal doses, but since the usual mechanism of apoptosis will turn back on as the drug clears the system, most of the irreparable cells will off themselves at that time.
Overall, I am cautiously optimistic about this.
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Apoptosis does not occur randomly. You must trigger it. In this case, with ionizing radiation-induced DNA damage, you have MMR proteins and the ATM/ATR system signaling to activate p53-dependent apoptosis. Since there are a number of checkpoints along the way, the cell that proceeds to apoptosis has already failed the evolutionarily-conserved tests for genome integrity and capability to repair its DNA damage.
It's is not feasible, given our knowledge of molecular biology, to prevent apoptosis after massive radiation exposure, without virtually guaranteeing a relatively quick (on the order of weeks to months) death from resultant tumors. The cell death mechanisms are there for a reason.
P.S. If you think dying from multiple foci of aggressive invasive lymphomas over a period of a couple of months is less painful than dying of massive GI epithelial and hematopoietic failure due to radiation sickness over a period of one week or less, then you haven't seen many cancer patients.
My understanding is that apoptosis on a massive scale can outrun the body's ability to repair itself, thus taking down the whole system. Using a drug to limit apoptosis should slow this process down and let the body properly heal. Presumably, cells that are "marked to die" will still ultimately die as the drug is withdrawn - just not all at once.
The researchers agree that cancer is a risk - but they report not having seen any in the lab animals thus far.
W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
... this compound doesn't fix damage done by radiation - rather it prevents the body from killing off the damaged cells, thus preventing radiation sickness. The makers speculate that it will increase cancer risk, but they so far have not observed this in lab animals.
And that seems about right. (Actually it prevents the cells that are damaged from killing THEMSELVES off.)
After an intense dose of ionizing radiation there's a lot of broken stuff hanging around in a cell. Some of this triggers the suicide mechanism. But if the DNA isn't damaged (or isn't damaged in a significant and non-repairable way) by the radiation or the subsequent debris, it can typically recover (if it doesn't "slit its own wrists").
Cell suicide for local damage, to prevent possible cancer from mutated cells, is an appropriate response. But suicide of the bulk of the cells kills the person, when surviving with a somewhat higher cancer risk later is not.
So it seems to me that a drug that temporarily suppresses the mechanism, used to let the body survive a radiation exposure event that would otherwise kill it, is indeed likely to result in a living subject with a somewhat higher cancer risk.
But as I recall the released studies on cancer risks among survivors of single high-dose radiation events - like nuclear lab accidents and Hiroshima/Nagasaki survivors - indicated a very small increase in cancer risk. So not seeing a significant bump in cancer rates among a small sample of lab animals in preliminary tests is hardly surprising.
So the claims seem plausible to me.
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Cells first developed radiation damage mechanism to repair UV damage. When photsynthesis evolved, cells wanted to get closer to the sun, yet avoid the effects of UV radiation in an Earth lacking an ozone layer. Ozone depends on free oxygen in the atmosphere which was scarce in the first half of Earth history.
The second inducement was the incorporation of mitochrondria into eucharyote cells. This gave cells ten times the energy they had before to eventually power animal locomotion. However, mitochrondria spew out all kinds of nasty poisons like free oxygen, protons, and high electric fields. Cells had to develop mechanisms to neutralize these.
It's true that it usually doesn't, but it sometimes CAN. A cell that has minor damage will most certainly be repaired. A cell that has major damage will lyse and hopefully be replaced by new cells. But when all of the cells lyse at once, there is no way to replace them fast enough. If you can keep most of the cells alive long enough for some non-damaged cells to proliferate, then you could theoretically have viable organs at the end.
Normally, it's more energy efficient to convert a damaged cell into basic components that can be reused than repair the cell, but the repair mechanisms do exist. Apoptosis can be halted, and things will go on relatively normally. The damaged cells might not work all correctly, but if faced with the option of 'die' or 'maybe die', I'll choose 'maybe die'. Plus, if the dangerous part of radiation therapy can be averted, the cancer I'm liable to get later is a lot easier to deal with.