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.
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To make one of the most sensitive diagnoses, hospitals might do well to call in a computer program. Researchers created a program that can sift through medical records and flag those patients who show signs of domestic violence. While emergency room doctors are always on the lookout for telltale signs, it may be hard to make the diagnosis from one or two isolated incidents. With this program, says lead researcher Ben Reis, “You are potentially able to detect high abuse risk years ahead of time: you don’t wait for a very bad thing to happen” [New Scientist].
Researchers first let the program scan through more than 350,000 medical records which included a substantial number of people who were eventually diagnosed as victims of domestic abuse, and asked the program to look for differences in their medical histories. The computer came up with a collection of risk factors that were highly associated with a future diagnosis.
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Amidst concerns over the safety of DEET, scientists are on the lookout for a new mosquito repellent. Now they may have found a way to keep biting insects at bay–by blocking their olfactory sense, according to a paper published in Nature.
Mosquitoes sense the presence of humans and animals by detecting the carbon dioxide we exhale with each breath. Researchers have found two compounds, 2,3-butanedione and 1-hexanol, that could keep the biters at bay by blocking the insects’ ability to detect this gas. Using these compounds could be advantageous because the amount of chemical required is relatively small…. Further, the chemicals themselves are not complicated to manufacture and are available through conventional sources. “From both perspectives, this adds up to a viable tool in tackling the problems like that of malaria in Africa” [Scientific American], says study coauthor Anandasankar Ray. Considering the number of diseases spread by insects such as mosquitoes–for example, 250 million people contract malaria each year–there’s a lot more at stake here than a few itchy bug bites.
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Birth rates have decreased by about 2 percent in 2008, the first year since the beginning of the decade that rates did not increase, according to statistics from the National Center for Health Statistics. Many experts speculate that this drop is due to the recession. Still, birth rate statistics have not yet been finalized, and some believe that a decrease in immigration could account for the decrease in births.
As any parent knows, children are expensive, so in a shaky economy, it makes sense that fewer people would be having them. “It’s the recession,” said [sociologist] Andrew Hacker… “Children are the most expensive item in every family’s budget, especially given all the gear kids expect today. So it’s a good place to cut back when you’re uncertain about the future” [New York Times]. Perhaps not coincidentally, the two states with the largest decrease in births–California and Florida–are also the ones that faced the biggest problems due to the housing crisis.
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Scientists seem to have finally put to rest a longstanding debate over itchiness: Is the urge to itch a sensation that is simply another interpretation of pain, or a separate feeling altogether? It turns out the two stem from different cells and neural pathways, according to a new study in Science.
To find out whether pain and itchiness are separate sensations, scientists injected mice with a neurotoxin. This toxin homed in on and killed cells that contained active versions of GRPR, a gene that is involved in the sensation of itchiness. (The same research group discovered this itch gene in 2007.) Afterward, the mice could no longer respond to any itchy stimuli. They didn’t flinch. They made no effort to scratch. But they did respond to pain just like other mice do [TIME], showing that the gene needed to be active to transmit itchiness, but not pain. It’s just one study, but it provides strong evidence that itchiness and pain are processed by separate neural pathways.
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An increasingly common surgical procedure for repairing spinal fractures might not be all it’s cracked up to be–in fact, the surgery had the same effect on patient’s pain as a placebo, two studies report in the New England Journal of Medicine.
The technique, called vertebroplasty, involves injecting medical cement into a fractured spine bone to strengthen it. More than 38,000 such procedures are done in the United States every year and the number has been [increasing] rapidly, nearly doubling from 2001 to 2005 [Reuters]. But the new studies showed that the procedure alleviated pain about the same amount as a placebo “surgery,” in which the physicians tapped on the spine and piped in the smell of cement to make groggy volunteer subjects believe they were receiving the real thing.
Researchers found that 36 volunteers who received sham surgery did just as well as 35 who got the real operation. A separate test, of 131 people at 11 medical centers, … also found that sham surgery produced a comparable degree of pain reduction and movement [Reuters].
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Powerful bug repellant DEET may do more than keep mosquitoes and other biting critters at bay–it might cause neurological damage in mammals, according to a study published in BioMed Central Biology.
Developed in 1946 by the U.S. Army, DEET has been used by the public for more than half a century to repel bugs like mosquitoes, along with the diseases they can carry. The new study, however, shows that DEET—aka N,N-diethyl-meta-toluamide—may be harmful for a variety of animal cells. In lab tests, it caused damage to mosquitoes, cockroach nerves, mouse muscles, and enzymes purified from fruit flies and humans. Applications of DEET slowed or halted the actions of the enzyme acetylcholinesterase. This enzyme hangs out between nerve and muscle cells, breaking down a messenger molecule after it has passed information from one cell to another. If this messenger isn’t properly recycled, it can build up and lead to paralysis [Science News].
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Few people enjoy being poked and prodded at the doctor’s office, but we usually assume that those unpleasantries are worth detecting a disease or disorder early on. Unfortunately, though, we might never hear about worrisome test results, according to a new study published in the journal Archives of Internal Medicine. Researchers found that about 7 percent of clinically significant test results are never reported to the patient or that the notification of patients is not documented, largely a result of medical information slipping through the cracks.
The researchers examined the records of 5,434 patients between the ages of 50 and 69 at 19 community-based primary care practices and an additional four academic medical care facilities. The patients were old enough to likely be developing conditions that warranted testing (such as for high cholesterol, impaired blood-sugar control, prostate cancer or waning liver function), but not so old as to be ill enough to make certain of these findings relatively unimportant. Patients’ records were reviewed for any of 10 types of blood tests and for three types of screening exams — mammography, Pap smears and occult blood assays of possible colon cancer. During a yearlong period, the participating practices had prescribed several thousand such tests [Science News]. The researchers found that physicians did not inform patients about abnormal test results about one out of 14 times, or around 7 percent of the time.
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Researchers may have finally figured out the mechanism of the tragic birth defects caused by thalidomide, the drug taken by pregnant women in the late 1950s as a remedy for nausea: It is thought to have inhibited development of new blood vessels at a crucial stage in the pregnancy.
Women usually took the drug at about five to nine weeks into their pregnancy to combat morning sickness, a specific window that lead researcher Neil Vargesson says “is crucial as that is when the limbs of babies are still forming…. The blood vessels involved in this process, at this stage of pregnancy, are still at an immature stage when they rapidly change and expand to accommodate the outgrowing limb” [BBC]. The most common birth defects caused by thalidomide were babies born with stunted or malformed limbs.
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The rate at which infants gain weight in the first six months of their lives is linked to those babies’ risk of becoming obese by age three, a new study has found. Researchers determined that sudden weight gain in early infancy was more important than how much a baby weighed at birth, the weight of the infant’s parents, or the number of pounds put on by the mother during pregnancy. “The perception has been that a chubby baby and a baby that grows fast early in life is healthier and all the baby fat will disappear,” said the paper’s lead author, Dr. Elsie Taveras…. “But [that] is not the case” [Chicago Tribune].
While the researchers note that early childhood obesity does not necessarily lead to obesity later in life, they say it does raise the risks. Obesity rates among U.S. children have doubled in the last 20 years, and almost a third of American children are either overweight or obese. The epidemic of obesity is linked to a host of health problems such as higher risks for heart disease, diabetes and cancer [Reuters].
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Men who are older when they father children tend to have children who score slightly lower on IQ tests and other measures of cognitive function, according to a new study. That conclusion, which researchers called unexpected and startling, adds to a recent surge of evidence that, like women, men also have a biological clock. Older fathers have been linked to a range of health problems, including an increased risk of birth deformities, autism and neuropsychiatric conditions, such as schizophrenia and bipolar disorder…. Experts believe mutations in a man’s sperm, which build over time, may be a factor [BBC News].
However, lead researcher John McGrath says that the findings shouldn’t cause panic. “With respect to childhood intelligence, a vast array of factors is far more powerful than paternal age,” McGrath cautions. These factors include nutrition, health care and family income [Science News]. Researchers say that adjusting for socioeconomic factors like family income lessened the link between paternal age and children’s cognitive scores, but didn’t erase it. The average IQ of a child born to a 20-year-old father was six points higher than that of a child with a 50-year-old father, but adjustments reduced the difference to three points. Researchers say that gap is statistically significant, but is modest in practical terms [Science News].
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Lab rats who were exposed to alcohol while in the womb had a skewed sense of taste and showed a marked preference for ethanol as young rats, researchers say. The findings may shed new light on why human studies have previously linked fetal alcohol exposure to increased alcohol abuse later in life, and to a lower age at which a person first starts drinking alcohol [New Scientist].
The taste of alcohol has both sweet and bitter components, and study coauthor Steven Youngentob wondered whether prenatal exposure could affect how rats respond to those elements. He gave young rats a choice between ethanol, sweet water flavored with sugar, and bitter water flavored with quinine. Those rats whose mothers had consumed alcohol while they were pregnant preferred ethanol and the bitter water. By contrast, rats who were not exposed to alcohol tended to plump for the sweeter alternative [Telegraph].
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Peanut lovers everywhere may have reason to celebrate. Doctors in England believe they have cured the peanut allergy, at least on a temporary basis. Using the simple technique of desensitization, doctors at the Addenbrooke Hospital in Cambridge exposed four children to peanuts over six months, during which time they successfully built up a tolerance. The children were started on 5 milligrams (.02 percent of an ounce) of peanut flour daily and by the end of the trial were able to ingest 880 milligrams a day, the equivalent of 5 whole peanuts. The study, which has been published in Allergy, continues and now includes 20 children between the ages of seven and 17, some of whom are able to ingest 12 peanuts a day. They would be monitored for the next three or four years to assess their tolerance levels, [lead researcher Andrew] Clark said, adding that there was no reason why the clinical trial could not be extended to adults [AFP].
Consultant allergist Pamela Ewan said, “Until now there has been no treatment that has modified the disease. There has only been effective management of the problems” [Medical News Today]. The new research brings hope to the many people, adults as well as children, who suffer from peanut allergy, which most often triggers breathing problems but can also cause potentially fatal anaphylactic shock or cardiac arrest.
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A chemical found in common household products and cosmetics has been linked to a decrease in fertility in women, according to a new study. Researchers examined more than 1,000 pregnant women and found that those exposed to higher levels of perfluorinated chemicals (PFCs) had experienced more difficulty getting pregnant. PFCs are used to make textiles and leather resistant to water, dirt or oil. They are also found in personal care products such as nail polish, dental floss or facial moisturizer. The chemicals resist breakdown and tend to persist in the environment and in the body for decades [Bloomberg]. “If this finding can be replicated, one would have to look for other chemicals to replace these,” [Washington Post] said lead researcher Jorn Olsen. Although experts caution that the correlation doesn’t prove causation, many manufacturers have already taken steps to cut back on PFCs.
Data for the study was taken from 1,240 women in the Danish Birth Cohort when they were six to 12 weeks pregnant. If they reported that it took them longer than 12 months to get pregnant or if they used drugs designed to increase their chances of conceiving, they were considered to have infertility. This is a generally accepted definition of infertility by experts in the field [ABC News]. The women were divided into four groups based on levels of two types of PFCs, perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA), found in their blood. Compared to women in the group with the lowest levels of PFOS, women with higher levels took from 70 percent to 134 percent longer to conceive. For PFOA, women with higher levels took from 60 percent to 154 percent longer to conceive. The researchers accounted for factors such as age and economic and social factors, although they admit that they lacked information on other factors that could influence fertility such as timing and frequency of intercourse and sperm quality.
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The fossilized pelvis of a Homo erectus woman who lived 1.2 million years ago on the banks of an Ethiopian river has been discovered, and while researchers say it casts new light on human evolution, some of their conclusions are challenging previous theories about these early human ancestors. The pelvis reveals a short, squat woman who wasn’t built for long-distance running, but also a woman with a wide birth canal to accommodate big-brained infants.
Study coauthor Scott Simpson says the pelvis’s wide birth canal indicates that hominds’ increasing brain size was a driving factor in human evolution. Getting through the birth canal is “the most gymnastic thing we ever do,” he says. To accommodate big-brained babies, humans must have developed larger and wider birth canals over time, but with few pelvic fossils, researchers had little idea when these changes began. The Busidima pelvis shows that a wide birth canal was already in place 1.2 million years ago [New Scientist].
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