Naked Mole Rat: a mighty survivor both hairless and nearly blind
Courtesy MissTessmacherThe naked mole rat (Heterocephalus glaber) is truly one of the most remarkable animals on this earth. On average 3 inches long and weighing just over an ounce, one would not think this creature so high and mighty. However, its unusual traits have brought it under more medical scrutiny and established an ever increasing presence in research laboratories. Stories have rung for years about how the only species to survive a world Armageddon would be cockroaches and rats. My money is on the naked mole rat.
While called a rat, they are one of 37 species of mole rats globally and are more closely related to guinea pigs and porcupines than other Rodentia. Limited to parts of East Africa, they spend their lives under ground in a highly social commune of individuals, all governed by a queen. This is very similar to the eusociality seen in bees and ants. The queen is the only female to breed, with all other individuals serving as guards or workers. This unusual social life for a mammal in a colony can lead to fierce competitions among females when the old queen dies. It may take days or weeks of power struggle before life in the colony returns to normal.
In search of plant tubers for sustenance, they dig through the dirt with their teeth, developing a system of burrows that can carry on for miles. One of the naked mole rats remarkable features is its ability to survive in the high carbon dioxide environments of these tunnels. Their extremely low metabolic rate and high absorption of oxygen allow them to overcome the limitations of the cramped and congested space. Research has found that these mole rats are void of a pain transmitter called Substance P found in other mammals, and have an uncanny resistance to the oxidative stress of daily metabolism.
Researchers hope this could lead to new insights into the process of aging. Captive research colonies have had individuals live as long as 28 years. That is more than nine times as long as a research mouse! This longevity and unique durability lead even more scientists to consider the naked mole rat for captive study populations in the fight against other afflictions like stroke and cancer. If these superman-like traits haven’t given you a deeper appreciation for such a tiny hairless creature, perhaps you just need a clever ditty to sing their praises. Oh! …you so UGLY!
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Playing with fire: Delicious fire.
Courtesy eshermanThe people of the world wait, their breath held, their tongues clenched between their teeth, open cans of Fresca frozen halfway to their mouths. What do you mean, JGordon? Does soda give me cancer? Or not?
Well?!
Don’t worry, folks. It’s mostly “or not.” Or is it? Or not.
You may have heard (or read—I call it “hearing with your eyes”) that soft drinks might raise your chances of developing cancer. That was probably hard to hear (or read—I call “listening through your face-holes”), because I know you’re generally pro-soda, and generally anti-cancer, and you had been living your life in the hope that there would never be any conflict between the two. You can probably go on living like that, because it’s unlikely that pop is really going to give you cancer, but you should be aware that the world is a complicated place, and your soda and your cancer are sadly not excluded from the complications.
See, a the results of a study out of the University of Minnesota were recently published claiming that there seemed to be a link between the regular consumption of soft drinks (sugar-sweetened carbonated beverages) and a higher incidence of pancreatic cancer. Pancreatic cancer isn’t one of the fun cancers (like, ah, cancer of the… nothing). Although relatively rare, the three-year survival rate for people diagnosed with pancreatic cancer is about 30%, and the survival rate after five years is only 5%.
The study was based on a 14-year survey of 60,524 men and women in Singapore. Of that group, 142 people developed pancreatic cancer. Examining the lifestyles of those who did and did not develop cancer, the researchers found that people who drank two or more soft drinks a week (5 was the average) had an 87% increase in their chances of getting cancer. And because Singapore is a fairly wealthy country with good health care, the scientists think that the results could apply fairly well to western countries as well.
Oh, no! Right? I can’t give up RC Cola!
Well… eh. The thing to keep in mind is it’s all very complicated. Even if there was a direct link between sift drink consumption and pancreatic cancer, your chances of developing the cancer, even as a soda drinker, would still be very small. But, the thing is, there isn’t necessarily a direct link between the two; there’s an association here, but maybe not a causal link. That is, people who drink soda are more likely to get pancreatic cancer, but we don’t know it’s the soda that causes the cancer.
Soft drink consumption itself was associated with behavior like smoking and red meat consumption, so it’s difficult to say that it’s just the soft-drinking (as it were) that contributes to the increased cancer risk.
Researchers do think, however, that it’s possible that soda could be involved in a causal relationship with the cancer. The high sugar levels in soda probably contribute to increased insulin production and presence in the body, which may contribute to pancreatic cancer cell growth. The study also found, however, that there was no association between fruit juice consumption and pancreatic cancer, which sort of makes me wonder. Lots of fruit juice, after all, is very sugary (even if it’s not quite so sweet as most soda). So does it have something to do with the type of sweetener used? Most soda in this country is sweetened with corn syrup, but that’s not necessarily the case in other countries (see Coca Cola for an example), and there’s some debate as to how the body might react to different sweeteners.
Anyway, you aren’t completely taking your life in your hands if you finish that can of Fresca. (Fresca was probably a bad example, seeing as how it uses artificial sweeteners, and will probably give you a totally different kind of cancer.) You’re better off just taking the dip out of your mouth. It’s gross with Fresca anyhow.
Nanosensors measure cancer biomarkers in blood
For the first time, a team led by Yale University researchers has used nanosensors to measure cancer biomarkers in whole blood. The new device is able to read out biomarker concentrations in a just a few minutes. Extremely small concentrations are being measured, the equivalent of detecting a single grain of salt within a swimming pool size volume of liquid.
"The new device could also be used to test for a wide range of biomarkers at the same time, from ovarian cancer to cardiovascular disease, Reed said. Science Daily.
Learn more by reading paper published in Nature Nanotechnology
Authors of the paper, "Label-free biomarker detection from whole blood", include Eric Stern, Aleksandar Vacic, Nitin Rajan, Jason Criscione, Jason Park, Mark Reed and Tarek Fahmy (all of Yale University); Bojan Ilic (Cornell University); David Mooney (Harvard University).
Distinct components within the sensor perform purification and detection. A microfluidic purification chip simultaneously captures multiple biomarkers from blood samples and releases them, after washing, into purified buffer for sensing by a silicon nanoribbon detector. This two-stage approach isolates the detector from the complex environment of whole blood, and reduces its minimum required sensitivity by effectively pre-concentrating the biomarkers. Nature Nanotechnology, Dec 13, 2009
Breast x-ray
Courtesy kristiewellsLately, there’s been a lot of hoopla in the news about the over-screening of certain cancers, particularly breast and prostrate cancers. Back in October, an opinion piece published in the journal of the American Medical Association (JAMA) by researchers at the University of California, San Francisco and San Antonio’s University of Texas Health Science Center, called for rethinking in the screening guidelines for those two cancers. Although the researchers admit the regular screenings are beneficial, Laura Esserman, MD at UCSF says, “The benefit is not nearly as much as we hoped and comes at the cost of over diagnosis and over treatment.”
In a New York Times story about the report, Dr. Otis Brawley, chief medical officer of the American Cancer Society (ACS) is quoted saying “We don’t want people to panic, but I’m admitting that American medicine has over-promised when it comes to screening. The advantages to screening have been exaggerated.”
The report went on to say the ACS was “quietly working on a message, to put on its Web site early next year, to emphasize that screening for breast and prostate cancer and certain other cancers can come with a real risk of over treating many small cancers while missing cancers that are deadly.”
But the American Cancer Society responded with a claim that, despite the headlines, it wasn’t changing its guideline recommendations regarding screenings, and continued to stress that a mammogram was still “one of the best things a woman can do to protect her health.”
The story resurfaced again in late November when the United States Preventive Services Task Force issued new recommendations regarding breast cancer screenings, calling for postponing initial mammograms for women until the age of 50 rather than 40. The task force, a federal advisory board, made its decision to change the guidelines after reviewing evidence presented to it by a team of oncologists. The American Cancer Society opposes the new guidelines.
This whole story is somewhat confusing. And it’s that confusion that causes some in medical community to worry.
“I am concerned that the complex view of a changing landscape will be distilled by the public into yet another ‘screening does not work’ headline,” said Dr. Colin Begg a biostatistican at New York’s Memorial Sloan-Kettering Cancer Center. “The fact that population screening is no panacea does not mean that it is useless.”
On a recent post on the KevinMD blogsite, Dr. Amy Tuteur tries to unravel some of the confusion explaining why some medical experts think aggressive screening (and severe treatment) for breast and prostate cancer has done little to lower the death rate from these particular cancers. The PSA test, for instance, is utilized much more often in the United States than it is in the United Kingdom to screen for prostate cancer, yet the death rate from the cancer in each country is pretty much the same. It should be noted that for some cancers regular screenings are making a difference. Colon and cervical cancers are often treated successfully with early detection and by removal of cancerous or pre-cancerous tissue.
The problem is not all cancers behave the same way. Some can start small, grow slowly and if caught in the early stages, be treated (or removed) before they become fatal. And that’s been the classic cancer treatment paradigm for a long time. If all cancers behaved this way, aggressive screenings would be the way to go. But over the past decades doctors and researchers have learned a lot more about cancer biology. They now know certain cancers can erupt suddenly and explosively and become fatal very quickly. Others can appear and remain dormant - sometimes for years - and never become a problem during the lifetime of the patient. But because screening practices have become more agressive, more of the non-fatal tumors are being spotted and treated unnecessarily. At the same time the screenings can sometimes be missing some of the aggressive cancers because they’re detected too late to treat. What’s needed is for doctors to be able to find a way to determine which tumors will become fatal.
“Without the ability to distinguish cancers that pose minimal risk from those posing substantial risk and with highly sensitive screening tests, there is an increased risk that the population will be over-treated.” --Dr. Laura Esserman
This topic is of interest to me, particularly this month, because December is when I get to subject myself to various post-cancer screenings (CT scan, blood and urine tests) and an annual visit to my oncologist. Three years ago I had my first colonoscopy. I was 54 years old at the time, and 4 years beyond the recommended age for a first colonoscopy. Although no cancer or pre-cancerous polyps were found in the colon, during the procedure the gastroenterologist – who, lucky for me, was thorough enough to go beyond the end of the large colon - discovered a tumor at the very beginning of my small intestine. It turned out to be a rare cancer that can usually be cured with surgery if it’s not too advanced. In researching it, I read that it is usually a slow-growing cancer – you can have it for years without experiencing any symptoms - but the surgeon told me it could also be very aggressive. It just depends. Getting it removed was the most prudent thing to do (it’s amazing how quickly you want to rid it from your body when you learn you have cancer), so I had the surgery and fortunately the tumor was still contained and the cancer hadn’t spread elsewhere. No chemotherapy or radiation was necessary (my type of cancer doesn’t respond to it), and I’ll be considered cancer-free if I pass my annual screenings for four years. I just passed my third checkup on Wednesday.
But here’s my point: when I was first diagnosed, one of my friends chastised me for waiting so long to have my first colonoscopy. I admit I dragged my feet, despite my doctor’s recommendation. It’s my nature to avoid dealing with unpleasant things. But who knows? Had I not delayed having the procedure done, maybe the carcinoid tumor in my small intestine would have been too small to be detectable during a colonoscopy, and then much more advanced (or completely gone on its own) by the time I had my next screening. I have no way of knowing if that would be the case. But I’m not saying I’ll continue to buck my doctors’ recommendations for screenings (my oncologist set me up for another colonoscopy next month - so I got that going for me), but I can’t help but think – at least in my case – maybe some of it did come down to luck and timing.
MORE INFO
CNN story
Time magazine story
Huffington Post story
Cancer screening guidelines at About.com
He looks happy, but it's a facade: He's very worried about phthalates, BPAs, and his manliness. (Good thing that's a glass bottle.)
Courtesy sirgabeThere’s something I want to get out of the way straight off the bat: the original title for this post was “Monday Nutrition Extravaganza: Chemicals in your food, playing with your manhood!” And while that has a certain whimsical charm, a re-read revealed hidden, disturbing meaning in those words. And I didn’t want to subject you Buzzketeers to that. I just thought you should know.
So, moving on, what’s this stuff playing with our manhood, now?
Chemicalz in our foodz! And stuff.
Earlier today, I came across this study about how there seems to be a correlation between high levels of chemicals call phthalates in pregnant mothers’ urine, and a lowered incidence of “masculine play” in their male children. (“Girls’ play behavior” didn’t seem to be affected.)
Interesting, interesting.
Phthalates are a group of chemicals added to plastics to make them softer and more pliable. We all like soft plastic—no one is arguing that!—but phthalates are all over the place, and increased exposure to them (all sorts of products and packaging use phthalates) is raising concerns about how those chemicals affect us, particularly during childhood development. See, phthalates are antiandrogens, meaning that they mess with the way your body works with hormones like testosterone. Testosterone plays an important role in how we physically develop, and perhaps in how we act. The boys whose mothers had higher levels of a couple kinds of phthalates demonstrated less “male-typical” behavior. The study looked a preferred toy types (trucks versus dolls), activities (“rough-and-tumble play”), and “child characteristics.”
Now, these are slightly sticky things to go judging kids on. Some folks might argue that these characteristics aren’t linked to biology so much as social conditioning. And it feels a little weird quantifying characteristics in children (and, let’s be honest here, characteristics which may not have a solidly identified “norm,” but nonetheless have all sorts of social and sexual baggage that we are uncomfortable with and often deal with in the worst ways). However, there does seem to be some statistical association here, whatever the causal relationship is. One hypothesis is that phthalates alter fetal production of testosterone at an important period of development, affecting “brain sexual differentiation.” It’s not so hard to imagine—a year ago I did a post on how certain common chemicals in pregnant mothers seemed to be causing penis deformities in their male children. The culprit there? Phthalates. The women in that story, however, had had exceptionally high exposure to phthalates (their jobs had them in constant contact with phthalate-containing hairspray), so it’s probably not something to lose sleep over, but it’s worth knowing.
And while phthalates aren’t supposed to be in food packaging, the next article I came across (this is an extravaganza, after all) deals with another plastic additive, BPA, that is found in food packaging, and which may also cause some hormone-related havoc.
BPA has come up on Science Buzz before. It’s in all sorts of packaging and bottles (it’s the reason your over protective mother doesn’t want you to use nalgene bottles) and it may affect tissue development, potentially increasing cancer risks.
We don’t care about that, though, right? Sure, cancer is out there, but in the future, not right now, you know? I know. But BPA’s latest appearance in the news may bring some immediacy to the concern over its use. Concern for some people. For men, I mean.
Chemical BPA in workers related to sex problems, says the Washington Post. “Sex problems”? We don’t want those! Chinese men working in a factory that uses BPA were found to have high rates of sexual problems. (I won’t be defining what “sexual problems” are because whatever you just imagined was probably correct.) Now, these guys have BPA levels about 50 times higher than the average American. But, still, something like 90% of Americans have detectable levels of BPA in their urine. Again, probably nothing to lose a lot of sleep over, but something worth knowing about. This professor is of the opinion that BPAs should be banned, even though most of us will probably never be exposed to dangerous levels of it, because a) it’s not a natural part of our diet; b) it’s not actually necessary in plastics processing; c) it accumulates in the body, and we still don’t know what level at which it begins to become harmful (ask those Chinese guys); and d) it’d be relatively easy to get it out of the food and water supply, unlike some other potentially harmful chemicals.
Accepting that scientific studies are necessarily very focused to eliminate variables, both of these stories still left me wondering what affect phthalates and BPAs have on women and girls. On one hand, one tries to avoid the mindset that average human physiology=male physiology, but on the other hand it’s usually just males that have penises, making their medical problems a little more hilarious.
There are so many… things out there, and they’re all doing… stuff! Interesting to know.
Pancreatic Cancer
Courtesy jasoneppink
Patrick Swayze dies from pancreatic cancer
A close friend of mine died from pancreatic cancer last year. Last week Patrick Swayze died from pancreatic cancer. Approximately 42,000 people in the U.S. will be diagnosed with pancreatic cancer this year. Nearly all of them will die within a year of its discovery. My friend had less than 3 months. With pancreatic cancer, by the time you supect something is wrong, it is too late.
Earlier cancer detection needed
What is needed is a test to detect cancer early from a urine, saliva, or blood sample. I recently wrote about a Lung cancer breathalyzer test.
MicroRNA in body fluids provides early cancer detection
A similar approach might work for pancreatic and other types of cancer. Certain small pieces of genetic code called microRNA have been associated with various cancers.
For pancreatic cancer, scientists have cataloged dozens of microRNAs whose levels are different than in healthy samples.
Out of the dozens of choices, researchers at the University of Texas M. D. Anderson Cancer Center picked four microRNAs to measure. Not only did the group detect these microRNAs circulating in the blood, they found their levels were higher in the blood of pancreatic cancer patients compared with healthy control subjects. Their results were published last week in Cancer Prevention Research. Scientific American
Learn more about microRNA markers for pancreatic cancer
MicroRNAs in Blood May be Biomarkers of Pancreatic Cancer National Institue of Health
Nano technology makes detecting lung cancer easy and affordable
Breathalyzer
Courtesy mrjorgen The breath of people who have lung cancer is different than those who don't. For years scientists have been perfecting techniques that determines what exactly is different.
Expensive and complicated tools like gas chromatographs and mass spectrometers were used to identify and measure 42 volatile organic compounds that represent lung cancer biomarkers. Sensors were designed to react to four of these compounds.
Gang Peng of the Israel Institute of Technology in Haifa and colleagues have now developed what they say is an inexpensive, portable sensor technology that can quickly distinguish between the breath of lung cancer patients and healthy people. New York Times
How lung cancer detectors work
Tiny gold nano size beads were coated with organic compounds that would react with the four lung cancer biomarkers. The particles were deposited as a thin film between two electrodes. The breath of someone with lung cancer reacts with the chemicals in the gold beads, changing their electrical resistance.
Learn more
Physics World has a more complete explanation of how gold nano beads sense lung cancer.
The abstract of the research paper titled "Diagnosing lung cancer in exhaled breath using gold nanoparticles can be found in Nature Nanotechnology.
A British woman is expecting the birth of a baby next week. Not so unusual, except that doctors screened the baby, through preimplantation genetic diagnosis (PGD), to be sure that he or she is free of a gene that causes breast cancer.
According to the article,
"The husband's grandmother, mother, sister and a cousin have been diagnosed with the disease [in their 20s].
While a daughter could have been affected by breast cancer herself if she carried the gene, a son could have been a carrier and passed it on to his daughters.
Mr Serhal said: 'The whole objective of this exercise is not just to make sure the child doesn't have the gene, but to stop the transmission from generation to generation.'"
Of course, the PGD doesn't guarantee that if the baby is a girl, she'll never develop breast cancer. There are other genetic and environmental causes for the disease. But at least she won't have the mutant gene that makes breast cancer a 50-80% certainty.
There's more on Buzz about PGD...
Students at Rice University are attempting to brew beer that contains resveratrol, a chemical that lowers the risk of heart disease and cancer. They plan to genetically engineer yeast, which is used in fermentation, to produce the chemical.
No word on how one can sign up to be a test subject.
Who is this?: "My... brain tumor"? No, I think you must have the wrong number.
Courtesy MikeSchinkelI’m not sure if it has come up on Buzz before, but there has been a long-running disagreement in the scientific community as to whether or not cell phone use increases your chances of developing cancer. (“Long running” relative to how long cells have been around, anyway.) Industry studies done ten years ago even suggested that there may be a link between cell phones and brain tumors, but other research completed since then has cast some doubt on those findings. The idea we’ve been left with, for the most part, seems to be that cell phones are more or less safe.
The debate has just recently been reignited, however. A group of scientists has warned congress that the studies denying a cell phone/cancer link may be severely lacking, an that new studies are demonstrating a pretty solid connection between exposure to the magnetic fields emitted by cell phones and the development of brain tumors.
The majority of studies used in the argument against a health link, the scientists point out, define “regular cell phone use” as once a week—far less than the average cell phone use currently. The group also draws on the analogy of cigarettes: it took 50 years for the health community to establish a convincing link between cigarette smoking and lung cancer, but that’s not something anyone would even question today. Scientists have had a far shorter time to study the long-term effects of cell phone use, and a brain tumor can take “dozens of years to develop,” so they argue that cell phone use should be treated with caution.
Several warning studies were shown to the congressional committee. Surveys from Scandinavia, where cell phones were first developed, showed that cell phone users were twice as likely to develop a tumor on the auditory nerves of the ear they usually held their phone to, compared to the other ear. An Israeli study showed that heavy cell phone users were 50 % more likely to develop salivary gland tumors. Recently published English research demonstrated that adolescents who started using cell phones before the age of 20 were five times more likely to develop brain cancer by 29 than those who didn’t use cell phones—all on the side of the head where they used their phones.
Kids are particularly vulnerable to cell phone emissions—the radiation penetrates far deeper into their brains than it does to adult users.
The goal of the scientists was to encourage further studies on the health effects of cell phone use, and to urge the Federal Communications Commission—in charge of monitoring setting limits to exposure to the radio spectrum—to review their standards.
It’s something to think about though, isn’t it, Buzzketeers? Something to think about while you’re trying to fall asleep, and you’ve got a head ache just on the right side…
What do you think? Would you change your cell phone use based on something like this? Or do you think people should wait for more information before they start changing their behavior? Or is this just a reason to text even more?
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