Sniffing Out Cancer
Makarand writes "Researchers at the Univeristy of Rome are developing an
electronic nose that
can sniff out cancer by sampling people's breath. The instrument uses sensors
that respond to the presence of chemical compounds in the patient's breath.
For example, lung cancer patients exhale alkanes and benzene derivatives
which the electronic nose will try to detect. The sensors are quartz crystal
sensors coated with a substance that binds to a range of organic chemicals.
If certain molecules in the breath bind to this surface coating they change
the natural vibration frequency of the crystal."
Cheap tests are what HMOs love. If this test could be run for $5 a patient, they could add it to twice-yearly checkup for people over 55 and catch tumors when they are small and more cheaply removed. I kinda shrug when they invent new million dollar procedures for helping with a disease as they won't be in widespread use for many years, but cheap accurate tests like these could be saving thousands of lives a year, in just a few years. This seems very cool.
It seems likely it comes at a cost though. The accuracy of chemical detection they are talking about would make for some damnably accurate breath and air analysis tools. I certainly hope we resolve our most recent bout of prohibition in the states before Breathalyzers that can detect days old residue in the lungs are on the hip of every officer in the state.
My grandmother did this for 20+ years. As head matron of a major metropolitan hospital, she learned that patients suffering from certain ailments exuded certain odors through their pores and often their breath too. My girlfriend, a nurse, told me something similar. The skin is one of the body's organs for expelling toxins, so it's no surprise that we can tell what toxins are in a person's body, for example, by sniffing them.
Pre-employment "drug" tests have been used to screen women for pregnancy, so I have no doubt that a cancer-detecting breathalyzer will be used to screen for other expensive conditions (or at least certify them as "pre-existing" and thus not covered by the company).
Scientists restrict study to entire physical universe; creationist
Sure would make the news easier to take from a dog than some weird machine.
One of my grandmothers died of lung cancer and I lived with her during her last days. I could smell a light flowery fragrance every time she coughed.
I am surprised that someone actually thought of using this as test for cancer, although I did suspect a link earlier.
Dogs have been able to do this for a long time. Several (under controlled, restricted, scientific circumstances) tests show that they (the dogs) can be taught this - a lot easier and cheaper than trying to build an electronic nose.
... "Hey - it can be done"
But
I remember a couple of years ago seeing this documentary with a computer wine taster. It would sniff the vapors coming off of a glass of wine and identify the vintage. There are professional winetasters (humans) that do the same thing for a living ... needless to say they had one of these winetasters on the show and the computer was more accurate than him. I'm glad they found a practical application of this idea, since, although the technology was cool in this wine example it seemed rather pointless ... except to piss off the human winetaster.
Quoth:
2) Biosensors and Bioelectronics is not a very disciplined journal, AFAIK (those in the field please correct me if I've been misinformed); you find a lot of good work in second tier journals, don't get me wrong, but you also find a lot of crap.
3) My dad does measurements of breath alkanes; ethane is produced by oxidized fatty acids, so it is a marker for patients with high tissue free radicals (what some people call "oxidative stress" even though there is no reason to think it is harmful, in and of itself.) They are highly variable - diabetics, for example, exhale a lot of them.
4) "e-nose"? Anyone who'd use that name has to be a sheister.
The good and new comes from no quarter where it is looked for, and is always something different from what is expected.
You mean benzpyrene. 3,4-benzpyrene looks like a base, chemically, and gets built into the DNA of the cells it comes into contact with. Basically, it's like writing random data on your hard drive. Each cigarette smoked causes about 20,000 mutations, but most of the time they are corrected by error correction mechanisms in the DNA replication process.
Did you know you can fertilize your lawn with used motor oil?
>The idea that dogs can distinguish between cancerous and non-cancerous tissue first surfaced in the United States in 1989, when a woman said that her border collie-doberman cross had spotted a skin tumour on her leg.
There may have been more than one such case. I read about a woman whose dog became obsessed with a mole on her back. One day when she was outside sunbathing her normally loving dog bit the area where the mole was. That got her to the doctor, who treated the bite and sent the mole to the pathologist. Melanoma.
My question is, how did the dog know that the abnormal smell was (A) important, (B) a problem?
... I remember interviewing a gent who was developing saliva testing techniques for the same purpose. His contention was that the digestive system affects and is affected by all the other systems in the body. The advantage is that it is also in contact with the external environment. As such it is a bellwether of interaction with the external environment (chemicals in air show up in saliva) and internal environment (breath, blood). A Google on "diagnosis using saliva" turns up some interesting stuff.
w w/465/textbook/otherprojects/senses_97/olfaction.h tml)
I'm not sure that sampling the breath is easier than sampling saliva but this site has a nice intro (http://www.bae.ncsu.edu/bae/research/blanchard/w
with a competitors technique here:
http://www.theinquirer.net/?article=6588
"Consensus" in science is _always_ a political construct.
Ok, it was 9 years ago, but the subject of it changed from possibilities of sensors array processing to trying to cope with the fact that those sensors were exhibiting horrible sensibility drift over time.
Because the main problem with those sensors is that they are using a chemical compounds that binds the gas molecule. To simplify, the weight of the bound gas molecules increases the load of the crystal, thus affecting its frequency response.
The main problem of such a system is that the binding tends to have permanent effects, thus altering durably the sensor response over time, up until it becomes unusable or exhibit too different a behavior for its signal to be processed efficiently.
What usually happens is that a misinformed journalist just happens to hear about that "famous new electronic nose"...
But up to now, such noses failed to find any industrial applications, just because of the sensivity drift. I clearly remember reading some literature from that Di Natale guy 9 years ago, making the same bold claims.
If someone from the italian team reads /., I will be greatly interested by there take on the drift matter.
[Pruneau
I'd have to agree that easier detection would almost certainly increase screening rates. According to the American Gastroenterology Association, only 30% of people who should be screened for colon cancer actually get the screening.
As someone with two second-degree relatives with colon cancer, this is something that's personally very important. I'd rather blow on the cancer detector than get medieval with the colonoscope.
At the same time, lets be reasonable.
When you blow your liver apart from drinking too much you fundamentaly rank lower on the transplant list than the 8 year old girl down the hall suffering from a bizarre liver failure.
I'm not saying that hospitals should turn away lung cancer patients who smoked a lot or something like that. I'm not sure I'm ok with my tax dollars going to bail them out of their highly self destructive habit though.
Of course, in a system where you don't want some disgruntled govt beurocrat making the calls it's better to fund than not to fund.
Killfile(TGK)
No trees were killed in the creation of this post. However, many electrons were inconvenienced.
I wouldn't want to try, but I think some UK scientists are trying to train dogs to do that(detect prostate cancer; not exactly in your ass, but close enough). Jay Leno's been mocking that all week. Go me, I get my health news from Jay Leno . . . wh00t
Or maybe I get it from the BBC too:
http://news.bbc.co.uk/1/hi/england/2006037.stm