Are CT scans putting thousands of people in unnecessary jeopardy for cancers and death? That was the suggestion by two new studies out this week, leaving radiologists scrambling to explain the true level of danger to worried patients.
A CT scan, also known as computed tomography, gives doctors a view inside the body, often eliminating the need for exploratory surgery. But CT scans involve a much higher radiation dose than conventional X-rays. A chest CT scan exposes the patient to more than 100 times the radiation dose of a typical chest X-ray [Reuters]. However, a study out of the University of California, San Francisco says, we might not have as good a handle on CT radiation as we thought. The researchers found that radiation differed greatly between machines, and some emitted 13 times more than others.
(more…)
In the not too distant future, testing for certain cancers may be completed in less time than it takes to watch an episode of Scrubs. A new portable device, expected to be about the size of a paperback book, works by detecting biomarkers in the blood, substances that suggest that a patient is diseased. The sensor, which uses nanotechnology, is so accurate that it could pick up a grain of salt in a swimming pool, claim the researchers [Telegraph]. With just a small amount of blood and 20 minutes, doctors can have an electronic read out of biomarker concentrations at their fingertips. The research, led by Mark Reed at Yale University, may lead to quick, easy, and low-cost cancer tests.
Reed says the technology would be ideal for measuring lung cancer biomarkers in a phlegm sample, or colon or ovarian cancer biomarkers in a blood sample, making their technology the first to measure biomarkers from normal samples of bodily fluids. Previous technologies work in much the same way, but can only detect biomarkers in purified solutions, not the real thing — meaning fluid samples from patients [U.S. News and World Report]. The applications aren’t limited to cancer biomarker measurements; the researchers say they could also measure cardiovascular disease biomarkers in small blood samples. The scientists have published their research in the journal Nature Nanotechnology.
Related Content:
80beats: Nanoparticles + Stem Cells = Faster Healing Wounds
80beats: Golden Nanocages Could Deliver Cancer Drugs to Tumors
DISCOVER: The Era of Nanoparticle Drugs Begins With Erection Cream
Image: Mark Reed / Yale University
Last week DISCOVER brought you the sad and somewhat counter-intuitive study that suggested loneliness could actually be “contagious” and spread across a social network. Now more bad news for the lonely. In a study (in press) in the Proceedings of the National Academy of Sciences, another team of researchers argues that, in rats at least, loneliness can increase cancer incidence.
The scientists separated their test rats at birth, keeping them either in groups of five or alone. Those kept alone had a 135% increase in the number of mammary tumours, a 8,391% increase in the size of tumours and a 3.3-fold increase in the relative risk of malignancy [Nature News]. They also showed higher levels of the hormone corticosterone, which is connected to stress.
(more…)
One of the persistent fears of our modern era is that cell phone radiation may cause brain tumors. But here’s some good news: A team of researchers in northern Europe, however, has now combed through three decades of cancer registries and found no increase in the rate of brain tumors in the five to 10 years following widespread cell phone adoption in that region [Scientific American]. The researchers, from the Institute of Cancer Epidemiology in Copenhagen, studied 20 to 79 year old men and women from Denmark, Finland, Norway, and Sweden, and paid special attention to cancer rates during the cell phone boom of the mid-1990s. The researchers published their analysis in the Journal of the National Cancer Institute.
Overall the study found that cancer rates were unchanged from the period before mobile phones were widely used. The study was based on 59,684 brain tumour cases diagnosed over 30 years from 1974 to 2003 among 16 million adults. During this time, the incidence rate of cancers known as gliomas increased gradually by 0.5% per year among men and by 0.2% per year among women. For cancers known as meningioma, the incidence rate increased by 0.8% among men and, after the early 1990′s, by 3.8% among women [BBC News]. The researchers say the larger meningioma increase in women is due to the greater age of the women in this group.
(more…)
It started as an observation in a Seattle cancer ward, where oncologist Marc Chamberlain noticed that his male patients were often receiving steadfast support from their wives, while his female patients often didn’t have husbands hovering at their bedsides. Based on this anecdotal evidence, Chamberlain decided to investigate divorce rates among couples where one person had recently been diagnosed with a serious illness. His findings raise troubling questions about the loyalty of the male sex.
The study included diagnoses of both cancer and multiple sclerosis and found an overall divorce rate of nearly 12 percent, which is similar to that found in the normal population. But when the researchers looked at gender differences, they found the rate was nearly 21 percent when women were the patients compared with about 3 percent when men got the life-threatening diagnosis. The researchers suggest men are less able to commit, on the spot, to being caregivers to a sick partner, while women are better at assuming such home and family responsibilities [LiveScience]. However, the study did find that the divorce rate was lower in longer marriages.
(more…)
When 3-year-old Mark Blinder developed pain in his right arm, doctors diagnosed him with Ewing’s sarcoma, a rare bone tumor. Chemotherapy wasn’t working and radiation would have destroyed the growth plates in his bones. So instead of amputating the arm, doctors tried an experimental approach–implanting an artificial, expandable bone made of titanium and cobalt chrome, designed specifically for Mark. The bone, produced by the company Biomet Inc., is small enough to fit inside the 3-year-old’s arm, but should be sturdy enough to last his entire life. Most artificial bones are used to replace only part of a bone, so they are glued securely to remaining bone. In Mark’s case, the entire humerus was being removed, so the prosthetic had to be attached to soft tissue [Los Angeles Times].
To install the bone, doctors first had to remove the tumor by carving out the fat around it, a process one of the doctor’s likened to carving out a peach pit without ever touching the pit. The surgery was a success but Mark, who is now 4 years old, underwent chemotherapy as a precaution. Mark is gradually relearning how to use his arm. He’s moving his wrist and fingers, can pick up small objects, and is receiving physiotherapy to rebuild strength and flexibility in the elbow and shoulder. He won’t ever regain full function in those joints, but he is using the arm more each day, his mother said [Los Angeles Times]. He will have to undergo three or four minor surgeries over the years so doctors can extend the prosthetic bone as he grows–but since the only other option open to Mark was amputating his arm completely, he probably won’t complain.
Related Content:
Science Not Fiction: Dr. Terminator: The Prosthetics Designer Who Makes Sci-Fi Sculptures
DISCOVER: High Powered Prosthetics: a bionic muscle 100 times stronger than yours
DISCOVER: Neural Prosthetics may be the next frontier
Image: iStockphoto
Cancer treatment in the future could have dramatically reduced side effects if new nanotechnology research proves useful. Heat-sensitive nanoparticles might be able to deliver drugs to a targeted location in the body—to a tumor, say—and release them on cue, a sought-after goal of biomedical research.
One research team has developed nanoparticle cages that can be stuffed with tiny amounts of drugs that are only released on demand. These “nanocages” are cubes of gold, with sides about 50-billionths of a meter long and holes at each corner. They are easily made, using silver particles as a mold, and then coated with strands of a smart polymer. The polymer strands are normally extended and bushy and cover the holes in the cube. But when heated the strands collapse, leaving the holes open and allowing the drug inside to escape [The New York Times]. The researchers say they can engineer the nanocages to stick to tumors.
Doctors could release the packaged drugs whenever they want, just by zapping the cages inside the patient’s body with near-infrared light. Near-infrared wavelengths are not greatly absorbed by body tissues, so light from a near-infrared laser could penetrate a couple of inches inside the body, but they are absorbed by gold [The New York Times]. Researchers could design the cages to fall apart at just a few degrees above normal body temperature, so they only spill their contents where the heat is applied; they could also alter the drug’s rate of release by adjusting the laser’s intensity. The technology, described in the journal Nature Materials, could help cut down on the side effects of today’s treatments which are often caused by toxic drugs coursing through the body.
Related Content:
DISCOVER: The Era of Nanoparticle Drugs Begins With Erection Cream
80beats: Nanoparticles + Stem Cells = Faster Healing Wounds
80beats: Did Chinese Factory Workers Die From Inhaling Nanoparticles?
80beats: Nanoscale Origami: A Box—With Lock & Key—Made Entirely of DNA
80beats: Nanoparticle “Smart Bomb” Could Stop Cancer’s Spread
Image: Younan Xia, Washington University in St. Louis
The naked mole rat is a species with a long list of peculiarities. The mole rat is about the same size as the more hirsute wild mouse, but lives seven times as long, sometimes reaching the ripe old age of 28. The creatures almost never poke their noses beyond the snug confines of their burrows and tunnels, and instead live out their lives underground in the dark. They’re also the only mammals who have a social structure that resembles an ants’ nest or beehive, where only one dominant female mates and reproduces.
Finally–and this is the part that most interests researchers–naked mole rats never get cancer.
A new study in the Proceedings of the National Academy of Sciences probed the mole rats’ robust good health, and determined how they beat cancer. The naked mole rat’s cells hate to be crowded, it turns out, so they stop growing before they can form tumors…. Normal human and mouse cells will grow and divide in a petri dish until they mash tightly against one another in a single, dense layer–a mechanism known as “contact inhibition.” Naked mole rat cells are even more sensitive to their neighbors, the researchers found. The cells stop growing as soon as they touch [ScienceNOW Daily News]. Researchers hope that the mechanism can one day lead to novel treatments for cancer, where cancerous cells won’t stop multiplying and form tumors.
(more…)
For all those patients who shudder at the thought of getting a colonoscopy and stubbornly refuse to make that appointment, there may soon be an alternative. Italian researchers have invented a “spider pill” that can be swallowed like a normal pill, but which later crawls through the intestines to check for signs of colon cancer. The researchers say the spider pill could be a great advance, because while the long and flexible endoscopes typically used in colonoscopies are very effective, many people balk at having a tube run through them.
The tiny bot contains a camera so doctors can monitor its progress through the digestive system (as demonstrated in this video). Once it hits the colon, doctors use a wireless link to command it to unfold its eight legs, and then order it to and fro so they can carefully check for polyps or tumors. Pills containing cameras already exist, but this is believed to be the first that can be controlled after it has been swallowed. Once the examination has finished, the spider pill exits the body naturally [Telegraph]. So far, the device has only been tested on pigs.
The researchers also invented a related device to survey the stomach, which contains more liquid than the intestines. That little bot uses propellers instead of legs to get around.
Related Content:
80beats: The World’s Smallest Motor Could Propel a Medical “Microbot” Through Arteries
80beats: Swallow This: New Electronic iPill Delivers Drugs On Command
DISCOVER: Robodoc
In very rare cases, the womb is a dangerous place for a developing fetus. Researchers have found that pregnant women can pass on cancer cells to their unborn babies, if those cancer cells carry a particular genetic mutation. The new study resolves a longstanding puzzle, because in theory any cancer cells that manage to cross the placenta into the baby’s bloodstream should be targeted for destruction by the child’s immune system. But there are records of 17 cases of a mother and baby appearing to share the same cancer – usually leukaemia or melanoma [BBC News].
In the study, which will be published in Proceedings of the National Academy of Sciences, researchers used a genetic “fingerprinting” technique to match the cancer cells found in a mother and baby. The case, involving a Japanese mother aged 28 and her daughter, revealed that both patients’ leukaemic cells carried the identical mutated cancer gene BCR-ABL1 even though the infant had not inherited this gene [The Times]. This meant that the child, who was diagnosed with cancer at the age of 11 months, could not have developed leukemia independently.
(more…)
The Nobel Prize for medicine has been awarded to three U.S. researchers who probed the mechanism of cellular division, and whose work opened new avenues both in the fight against cancer and attempts to slow aging. The prize will be shared by Australia-born Elizabeth Blackburn, Carol Greider, and London-born Jack Szostak.
The three researchers solved the mystery of how chromosomes, the rod-like structures that carry DNA, protect themselves from degrading when cells divide. The Nobel citation said the laureates found the solution in the ends of the chromosomes — features called telomeres that are often compared to the plastic tips at the end of shoe laces that keep those laces from unraveling [AP].
(more…)
The first scientific autopsy on an ancient Egyptian mummy, performed back in 1825, might have botched the cause of death. The original ruling was that the mummified woman, Irtyersenu, died of ovarian cancer, but a new study strongly suggests she died of tuberculosis [BBC News]. The original autopsy was performed by one Dr. Augustus Bozzi Granville, a surgeon and a gynecologist (and apparently a fan of infectious diseases; he personally overcame bouts with malaria, bubonic plague and yellow fever).
Irtyersenu is a remarkable specimen in that she was mummified with her organs intact. Most mummies have their organs removed or dissolved inside their bodies prior to mummification. Dr. Granville was correct in detecting that the mummified woman had an ovarian tumor—but later studies determined it was benign. Granville studied her pelvic bone and also determined the woman to be an overweight mother between the ages of 50-55 when she died.
(more…)
The presidential panel that recently evaluated the U.S. plan for manned spaceflight declared that “Mars is the ultimate destination for human exploration,” but stressed the financial and technical difficulties that must be overcome before a boot can be planted on that red soil. Now, the New Scientist calls attention to the greatest technical hurdle: protecting astronauts from radiation during their trips to Mars.
The radiation comes in the form of cosmic rays, which are actually speeding protons and heavier atomic nuclei that rain onto our solar system from all directions. They can slice through DNA molecules when they pass through living cells and the resulting damage can lead to cancer [New Scientist]. The residents of Earth and the temporary lodgers at the International Space Station are protected from the rays by the Earth’s magnetic field, but astronauts heading to Mars would have no natural protection. Aluminum or plastic shielding on a spacecraft would have to be impractically thick to safeguard astronauts, and other solutions, like the creation of a miniature magnetic field around the spaceship, are still being developed.
(more…)
This year, the most prestigious medical awards in the United States have been given to two stem cell researchers, three cancer researchers, and one New York City mayor. Each year, the three prestigious Lasker Awards are given to those who have made great progress in combatting human disease, and they come with a prize of $250,000 in each category. They are sometimes called “America’s Nobels,” in part because 76 Lasker laureates have gone on to receive the Nobel Prize [USA Today].
The basic medical research prize went to John Gurdon and Shinya Yamanaka; although their breakthroughs were separated by 50 years, both researchers’ work led to the current technique of turning ordinary skin cells into multipurpose stem cells. Lasker Foundation president Maria Freire explains that Gurdon’s work showed that the nucleus of every cell retains a latent ability to become any other cell type and Yamanaka showed how that capacity can be unleashed…. “These two pieces of research allow us to understand different aspects of stem cells,” she said. “I think it could lead to personalized replacement therapy to fix cells or damaged tissue” [Bloomberg].
(more…)
Over the past four years, a controversy has erupted over whether to routinely give girls the new vaccine against the human papillomavirus (HPV), a sexually transmitted virus that can cause genital warts and cervical cancer. Now we can have the debate all over again–but this time, with boys. An advisory panel of the Food and Drug Administration has recommended that the vaccine be made available for boys as well. While boys are obviously not at risk for cervical cancer, HPV can give them genital warts and, in very rare cases, can lead to anal or penile cancer.
The pharmaceutical giant Merck makes the first HPV vaccine available in the United States, Gardasil, which is considered most effective when given to young people who aren’t yet sexually active and therefore haven’t yet encountered the virus. But analyst Tim Anderson says that the regime of three shots over six months may deter some customers. “You are asking a healthy teen to come to the doctor three times in six months,” Mr. Anderson said…. “Pretty much no healthy teen would ever do that, let alone to come back and get a shot” [The New York Times]. It may be a particularly hard sell because most cases of genital warts clear up naturally, and because anal and penile cancers are so rare–each year they’re diagnosed in about 2,100 and 1,300 American men respectively.
Related Content:DISCOVER: How We Got the Controversial HPV Vaccine
DISCOVER: The Battle Over the Cervical Cancer Vaccine Heats Up
80beats: Male Circumcision Cuts Risk of HIV, Herpes, and HPV Transmission
80beats: Nobel Prize for Medicine Awarded to Virus Hunters
Image: flickr / lu_lu
