The U.S. Justice Department has officially instructed federal prosecutors around the country to stop going after medical marijuana users who are complying with state laws. A total of 14 states now have some provisions for medical marijuana use.
A memo from Deputy Attorney General David Ogden said it was “unlikely to be an efficient use of limited federal resources” to prosecute “individuals with cancer or other serious illnesses who use marijuana as part of a recommended treatment regimen” [The Wall Street Journal]. The memo emphasized, however, that prosecutors should continue to target drug traffickers and distributors who use state laws as a cover for illegal activity.
Supporters of the policy change say it represents a new emphasis on violent crime and the sale of illicit drugs to children…. But some local police and Republican lawmakers criticized the change, saying it could exacerbate the flow of drug money to Mexican cartels, whose violence has spilled over the Southwestern border [Washington Post].
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Image: flickr / Neeta Lind
For many rape cases, the only leads investigators have to follow are the clues spelled out by a DNA sample. If after years the DNA isn’t matched to a suspect the case goes cold and the victim never has closure. A few years ago, when there was still a statute of limitations for rape in New York City, prosecutors devised a clever way to side-step the ticking clock—they decided to simply indict the DNA profile. Since then, New York City prosecutors have secured 117 indictments of DNA samples in rape cases, linked 18 of those profiles to specific people, and obtained 13 convictions, either through trials or negotiated pleas. Five cases are pending [The New York Times].
Called John Doe DNA indictments, the strategy is also used in a handful of other states to help solve sex crimes, and its success has prompted officials to expand DNA indictments to other types of crimes. In New York, authorities are now collecting more DNA evidence from the scenes of everyday crimes. They hope to use DNA to help solve unsolved crimes from the past that are subject to a statute of limitations, like burglary, robbery or serial car theft [The New York Times]. Opponents of John Doe DNA indictments say the passage of time, along with fading memories and disappearing witnesses, hinders the defendant’s ability to mount a defense, and that old DNA samples are subject to depredation and mishandling. However New York officials counter by saying it’s irresponsible to ignore genetic evidence, especially with modern molecular biology tools.
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Image: flickr / [puamelia]
Look into the future and see the women of tomorrow! A new study predicts that future women will be a tad shorter, heavier, and more fertile—that is, if the women who are currently most successful at producing children are any indication. The team studied 2238 women who had passed menopause and so completed their reproductive lives…[and] tested whether a woman’s height, weight, blood pressure, cholesterol or other traits correlated with the number of children she had borne. They controlled for changes due to social and cultural factors to calculate how strongly natural selection is shaping these traits [New Scientist].
Their results show that shorter, heavier women tend to have more children, as do women with lower blood pressure and cholesterol. If the mothers pass on these traits for 10 generations, the average woman in 2409 will be 2 centimetres shorter and 1 kilogram [about 2 pounds] heavier than she is today. She will bear her first child about 5 months earlier and enter menopause 10 months later [New Scientist]. A two-centimeter decrease over 400 years may be a modest change, but the researchers say it’s evolution in action. The study will be published in Proceedings of the National Academy of Sciences.
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With a little deception and an fMRI machine, scientists have traced the placebo effect to the spinal cord, according to new research published in the journal Science. The placebo effect, of course, is the well-known phenomenon in which patients who think they are getting medical treatment report that they feel better, even when they get only a sugar pill or other fake therapy [Los Angeles Times]. To test the limits of the placebo effect, researchers applied an anesthetic “lidocaine” cream to one arm, and a “control” cream to the other, making sure to tell the subjects which cream was which. The researchers applied a hot stimulus for 20 seconds to the skin where the each cream was applied. Participants said the “lidocaine” cream reduced pain by an average of 26 percent.
This would all be fairly straightforward had the researchers not been lying to their test subjects. You see, neither cream had active ingredients. They also primed a response by turning down the painful heat for the painkiller cream in a first test run, and so tricked volunteers into thinking that the cream would work the next time. But actual tests with an MRI scanner on involved the same level of heat for both creams. Volunteers nonetheless reported less pain with the painkiller cream [Popular Science].
The fMRI data backed up the participants’ pain perception. Normally when a person experiences pain, the dorsal horn area of the spinal cord near the lower neck will appear to be on fire with activity, but the fMRI scans showed nerve activity was reduced significantly when subjects believed they were getting the anesthetic [Reuters]. The researchers say this indicates that “psychological factors” can have an effect on pain outside of the brain. They hope to develop new treatments that can exploit the placebo effect’s painkiller effect.
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Image: flickr / fbaett
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.
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Sigh. Less than three weeks after health officials convened a press conference in Thailand to announce a rare piece of good news in the hunt for an HIV vaccine, some scientists are asking whether the results were overstated.
The large clinical trial of the vaccine was a modest success, but it was plenty exciting for HIV vaccine researchers who have been waiting for years for any sign of progress. The U.S. Army and Thai researchers who collaborated on the trial found that the vaccine lowered the risk of infection by about 31% — a “modest benefit,” they said, but one that was statistically significant, suggesting the finding was not a fluke [The Wall Street Journal, blog]. But the press conference did not trumpet another analysis of the data, which included only those volunteers who carefully followed the experiment’s rules and got the full regimen of six shots at the right times. This second analysis showed a 26 percent rate of protection, and a much higher chance that the benefit was a fluke.
Some scientists say both analyses should have been revealed during the September announcement, and claim that the way the press conference was handled further undermines the research. “The press conference was not a scholarly, rigorously honest presentation,” said one leading HIV/AIDS investigator, who like others asked that his name not be used. “It doesn’t meet the standards that have been set for other trials, and it doesn’t fully present the borderline results. It’s wrong” [ScienceInsider].
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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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A new genetic analysis has confirmed that the “royal disease” suffered by the male descendants of Queen Victoria was in fact a rare type of hemophilia, the genetic disease marked by a deficiency in blood clotting. Queen Victoria had several sons that died from blood loss after seemingly minor injuries. The disease spread as her descendants married into other royal families across Europe, altering Western history.
Based on the sons’ reported symptoms, modern researchers had already hypothesized that the royals had hemophilia, but there was never any concrete evidence. Now, new DNA analysis on the bones of the last Russian royal family, the Romanovs, indicates the Royal disease was indeed hemophilia, a rare subtype known as hemophilia B [ScienceNOW Daily News]. The genotyping study was published in the journal Science.
To pinpoint the exact form of the disorder, the scientists extracted DNA from the skeletal remains of Queen Victoria’s great grandson Crown Prince Alexei of Russia’s Romanov family and decoded the genetic information. (The bones were found in 2007, and it was only earlier this year that they were confirmed to have belonged to the murdered prince, who was killed during the Russian revolution.) The new analysis discovered a mutation in a gene on the X chromosome that codes for the production of Factor IX, a substance that causes blood to clot [BBC News]. Since the mutation is on the X chromosome, the disease is carried by females but usually shows up only in male descendants, because they don’t have a second X chromosome with a working copy of the gene. Researchers say the finding of hemophilia B in the Romanov’s closes the case on the cause of “royal disease.”
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Image: State Archives of the Russian Federation
Sufferers of the baffling ailment known as chronic fatigue syndrome, take hope: For the first time, there’s good evidence that the symptoms aren’t just in your head, and experimental treatments may be coming soon.
Over the past few decades, the syndrome has been a source of intense frustration both to patients diagnosed with it and doctors who try to treat it. The diffuse collection of symptoms can include incapacitating fatigue, muscle aches, headaches, problems with concentration. Doctors, meanwhile, have been mystified by the cause of the symptoms, and some have suggested that it’s a psychiatric problem, leading to the coining of the dismissive label “yuppie flu.”
Now, researchers report that 68 of 101 patients with the syndrome, or 67 percent, were infected with an infectious virus, xenotropic murine leukemia virus-related virus, or XMRV. By contrast, only 3.7 percent of 218 healthy people were infected. Continuing work after the paper was published has found the virus in nearly 98 percent of about 300 patients with the syndrome, said Dr. Judy A. Mikovits, the lead author of the paper [The New York Times]. While it hasn’t been proven that the virus causes the syndrome, the link opens new avenues of research and treatment.
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Two researchers have reviewed the body of research on the effects of birth control pills on both women and men’s perceptions of attractiveness, and have come to some provocative conclusions. Women on the pill are less attracted to hyper-masculine men, they found, and don’t show the typical propensity towards men who are genetically dissimilar from themselves. In addition, women on the pill may lack the attractiveness edge that’s associated with ovulation, the study found.
An alarmist, tabloid-esque summary of the findings might read like this: Pill-taking women aren’t hotties, and they pick girlie men who are likely to give them ugly babies. But of course, there’s a lot more complexity to the findings. The contraceptive pill alters monthly fluctuations in hormones associated with the menstrual cycle, mimicking the more stable hormonal conditions associated with pregnancy [New Scientist]. While mounting evidence suggests that having one’s hormonal levels smoothed out in this way alters some of the laws of attraction between men and women, scientists hasten to add that hormones aren’t everything.
The new study (pdf), published in Trends in Ecology and Evolution, looked first at research that’s been conducted on women’s preferences for men. Women who aren’t on the pill have shown a preference for certain types of men while they’re ovulating: they prefer men with more traditionally masculine facial features, and have also been shown to prefer the smell of men who are genetically dissimilar (which in humanity’s earlier days, when inbreeding was a danger, would have been an advantage). Women on the pill don’t show these same preferences. But many would argue that personality is a far better way to choose a life partner than what they smell like. One recent study involving speed-dating experiments suggested that although women might say they prefer the scent of men with dissimilar immune systems, this doesn’t correspond with the men they actually chose to go out with [New Scientist].
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A new study may have hit upon another way to improve stem cells‘ ability to help repair damaged tissue. While stem cells can rapidly grow into any kind of new tissue, they aren’t always able to encourage new blood vessels to grow so that the tissue stays alive. But in a new study, published in the Proceedings of the National Academy of Sciences, scientists describe a way around the problem. The researchers used nanoparticles to ferry a key gene into the stem cells, which caused the cells to recruit new blood vessels, thus fueling tissue growth.
The nanoparticles carried a gene (VEGF) that is known to stimulate new blood vessel growth. When the modified cells were injected into mice whose hind limbs had been injured, the tissue that regrew to repair the damage had three times the blood vessel density of similar tissue in mice given unmodified cells. Four weeks later, only 20 per cent of the mice given modified cells had lost limbs, compared with 60 per cent in mice that received unmodified cells [New Scientist].
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Swine flu vaccines have arrived! Or more accurately, limited amounts of the first available vaccine, a nasal spray, have been delivered to distribution points around the country, and several states began vaccinating health care workers and young children on Monday. It’s not a moment too soon: The Centers for Disease Control and Prevention have announced that flu is now widespread in most of the United States. The infections are “overwhelmingly” pandemic H1N1 influenza, commonly known as swine flu. The flu season generally lasts well into May, so many months of uncertainties lie ahead [Los Angeles Times].
CDC director Thomas Frieden says that so far, vaccine “demand is outstripping supply, but we expect that fairly soon supply will be outstripping demand.” … Over the next two to three weeks, tens of millions of additional doses will become available [Los Angeles Times]. The injectable form of the vaccine will be ready for distribution next week.
Now that the vaccines have been successfully hustled off the assembly lines, the next daunting challenge for public health officials is convincing people to go get vaccinated. Myths and worries about the vaccine have spread on talk radio and anti-vaccine Web sites [The New York Times], with even celebrities like Bill Maher unhelpfully chiming in via Twitter. At a Tuesday press conference, Frieden strongly refuted one of the most commonly voiced concerns: that in rushing the vaccine through production, it wasn’t properly tested for safety.
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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].
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Babies born in rich nations today have the best shot at becoming centenarians. That’s if current life expectancy trends continue, according to the study published in The Lancet.
Not only will these babies live longer, but they’ll be healthier well into old age. The researchers based their projections on a case study of Germany that showed that by 2050, its population will be substantially older and smaller than now — a situation it said was now typical of rich nations [Reuters]. In the United States, half of the babies born in 2007 are expected to live to a ripe 104 years old. The authors credited improvements in health care, medicine, and lifestyle, as well as a drop in infant mortality rates, for increased life spans.
Data from more than 30 developed countries shows that since 1950 the probability of surviving past 80 years of age has doubled for both sexes [BBC News]. However, the study cautions that despite improved life expectancies, an increase in cancer, cardiovascular disease and other chronic illnesses has risen with aging populations [ABC News]. As citizens get older and require more medical care, the increased life expectancies may place a burden on society. Already, many countries are pushing to extent the retirement age to grapple with the costs.
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Image: flickr / Will Foster
A team of researchers recently discovered that Tamiflu, the leading flu-fighting drug, is accumulating in rivers downstream from sewage-treatment plants in Kyoto. How is this possible? Tamiflu’s active ingredient, oseltamivir phosphate, is excreted in the urine of people taking the medication. Concerns are now building that birds, which are natural influenza carriers, are being exposed to waterborne residues of Tamiflu’s active form and might develop and spread drug-resistant strains of seasonal and avian flu [Science News]. The resistant virus strains would be of the conventional seasonal or avian flu variety, not the H1N1 swine flu strain that is currently pandemic in humans. Seasonal flu, however, kills thousands of people each year.
Study coauthor Gopal Ghosh explains that the team took measurements during normal flu season, and found concentrations that seem “high enough to lead to antiviral resistance in waterfowl” [Science News]. Computer models show that oseltamivir phosphate will survive sewage treatment, but it should break down when exposed to sunlight and its concentrations should decrease by half every three weeks. The high concentrations were found during a period where 1,738 flu cases were reported in Kyoto, according to the study, published in the journal Environmental Health Perspectives. In the United States, Tamiflu is only recommended for the very sick or those with compromised immune system, while Japan has a more liberal policy.
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Image: flickr / law_keven
