From: Adam McLean [mailto:email@example.com]
Sent: Tuesday November 20, 2001 11:33 PM
To: Canadian Nuclear Discussion List
Subject: [cdn-nucl-l] Another new use for Nuclear Waste!
Posted on CBC on November 16, 2001 and at:
Human trials in the next few MONTHS?! Wow.
Radioactive atoms blast cancer from inside
Last Updated: Fri Nov 16 15:06:56 2001
NEW YORK - Scientists say they've discovered a method using nuclear waste to
attack cancer cells without harming healthy tissue.
Adam & group,
This is another example of CBC's journalistic spin.
As usual, the public gets to read BS, instead of learning something. ( Astronomer Carl Sagan said that "we are made of star stuff," but a more accurate statement would have been that "we are made of nuclear waste" -- the ashes left over from the nuclear fusion reactions of a supernova explosion billions of years ago....)
FYI, here is some more info (+ more spin) on this (not so new) research:
Sunday July 30, 2000
Nuclear Waste May Help Cancer
OAK RIDGE, Tenn. (AP) - Locked away for more than 40 years in guarded concrete vaults at the Oak Ridge National Laboratory may be the key to a promising new therapy for cancer patients.
The lab's 11/2-ton cache of weapons-grade uranium-233, until now considered waste, is the nation's only readily available source for a potent isotope that can kill leukemia cells without harming healthy cells.
``It is kind of like a little bomb going off that you can target right to that cancer cell,'' the lab's program manager Jim Rushton said.
Researchers at Memorial Sloan-Kettering Cancer Center in New York are developing the ``alpha particle immunotherapy'' and last year completed initial human tests.
The isotope bismuth-213 was attached to an antibody designed to carry the alpha-emitting isotope to the cancer. The tests were to see if the treatment did more harm than good in acute myeloid leukemia patients.
The results were a surprise. Not only was the therapy safe, but leukemia cells were eliminated in the blood stream and reduced in the bone marrow of 13 of the 18 patients taking part, said Dr. Joseph Jurcic, one of the researchers.
``We really think it has broad implications for the whole field of oncology, not just for leukemia,'' he said.
The researchers don't envision bismuth therapy replacing chemotherapy or surgery. Rather they see its potential in ``cleaning up residual cancer cells that are remaining behind after primary treatments,'' he said.
This is no small challenge. Jurcic said only 30 percent to 40 percent of acute leukemia patients are cured by chemotherapy.
``The majority of these patients go into remission with chemotherapy, but they relapse because of these residual cells. That's where we think the bismuth is going to be particularly useful.''
This fall, Sloan-Kettering, under the watch of the National Cancer Institute, plans to start a second phase of testing with 35 to 40 patients to measure the therapy's effectiveness. The trials could last three years.
``The advantage of alpha-emitters is that they deposit a large amount of energy in a very small area of tissue,'' said Dr. Jorge Carrasquillo, deputy chief of nuclear medicine at the National Institutes of Health.
Attaching the bismuth to antibodies that can carry the radiation dose straight to diseased cells is an ``innovative treatment,'' and Sloan-Kettering is leading the way, he said.
``Of course it is too early to tell the final role,'' Carrasquillo said, ``but it certainly is a strategy worth pursuing.''
The problem was getting more bismuth-213, an exotic isotope with a 46-minute half-life, which makes it perfect for injecting into patients because it quickly dissipates but makes it difficult to acquire.
Bismuth-213 can be obtained in what physicists describe as a decay chain from uranium-233. First, thorium-229 is extracted, then actinium-225 is taken from that and then the bismuth is extracted from the actinium.
The search for thorium led to the uranium-233 stockpile in Oak Ridge.
Energy Secretary Bill Richardson agreed last month at the behest of Sen. Fred Thompson, R-Tenn., and Rep. Joe Knollenberg, R-Mich., to double the supply of bismuth-213 by 2002 for the Sloan-Kettering research.
Rushton said only 1 percent of the available bismuth-213 has been recovered from Oak Ridge. The total of bismuth-213 there is infinitesimally small - so small that it is measured by its radioactivity instead of its weight.
A typical shipment to Sloan-Kettering ``is literally a spot of material that is dried in the bottom of a vial. It looks like the vial is empty,'' Rushton said.
But researchers believe there is enough high-powered bismuth-213 at Oak Ridge to treat up to 100,000 cancer patients a year.
Oak Ridge's uranium-233 was made at the government's weapons fuel production plants in South Carolina and Washington state in the 1950s and 1960s. However, it was never intended for bombs, rather to fuel commercial nuclear plants.
At the time, uranium sources were scarce and nuclear power generation looked full of promise.
``But nuclear power did not grow as rapidly as the too-cheap-to-meter advocates had said, and people found all kinds of uranium out there,'' Rushton said. ``The price fell and the economic need for this as an alternative fuel never developed.''
And so the uranium-233, considered more hazardous than enriched uranium for weapons - which also is stored in Oak Ridge - has remained at the Oak Ridge lab complex. It costs $15 million a year to store, and some experts estimate it will cost even more to dispose of.
Although the bismuth extraction will not reduce the volume of uranium-233, it at least gives value to the uranium's manufacture, Rushton said.
``We spent a lot of money making this stuff,'' he said. ``If we had disposed of all this 10 years ago, we wouldn't have the option to look at bismuth-213 today.''
Nat Post Nov 16 2001
Tiny 'Trojan horse' device zaps cancer then disappears
Tested on mice: New approach delivers an atom of radioactive material
Margaret Munro, National Post
In a development reminiscent of a miniaturized Raquel Welch navigating through the bloodstream in Fantastic Voyage, researchers have developed tiny injectable "nanogenerators" that slip into cancer cells, blast them with radiation and then disappear from the body without a trace.
The devices, which contain a single but potent radioactive atom inside a molecular cage, appear to have cured prostate cancer and leukemia in mice with no apparent side effects, the New York researchers report today in the journal Science.
Dr. David Scheinberg and his colleagues at the Memorial Sloan-Kettering Cancer Center have also shown the devices can invade and destroy several varieties of human cancer in test tubes.
Though cautious about reading too much into the results, the doctors say the work is so promising they hope to try injecting the mini-cancer blasters into human patients next year. And they talk of one day mass-producing the devices and shipping them around the world for use.
The editors of Science liken the action of the nanogenerators to a "Trojan horse attack on cancer cells" and have flagged the work as an important development in the race to devise minuscule -- or "nano" -- cancer therapies.
Several teams around the world are engineering devices -- one group at the University of Michigan is trying to develop what they describe as injectable "nano-bombs" -- to maximize cancer destruction while minimizing side effects.
The New York team says its "nanogenerators" produced dramatic results in mice with prostate cancer and leukemia. Most of the mice had their lives extended after a single treatment and many appeared cancer free.
At the heart of the nanogenerators is a radioactive atom called actinium-225. It is stuffed inside a molecular cage that is attached to antibodies, which latch on to cancer cells. Actinium-225, a waste by-product of nuclear weapons and energy programs, gives off high-energy alpha particles that can destroy DNA and proteins.
The way nanogenerators slip inside the cancer cells makes them very efficient killers.
"If the atom is sitting on the outside of the cell, the alpha particle can travel in any direction, and it kills the cell only a fraction of the time," says Dr. Michael McDevitt, lead author of the Science report. "If the generator is inside the cell, every particle will be effective."
The doctors say actinium-225, which loses most of its radioactive punch after 10 days, would eventually disintegrate and be flushed from the body with the dead cancer cells. "The atoms decay to a stable substance, which has no effect on the body due to the tiny quantities," Dr. Scheinberg says.
And the travel range of the alpha particles given off by actinium-225 is very short. So the nanogenerators should do little harm as they travel through the blood before latching on to and entering cancer cells, he says.
Some researchers talk of one day reducing cancer therapy to a few injections of nano-devices. Dr. Scheinberg, chief of leukemia service, is making no such predictions. "It is never so simple," he says.
But he and his colleagues do believe nanogenerators may make cancer treatment less toxic, without the hair loss and nausea common to cancer therapies now in use.