Majority of cancer types due to "bad luck"
Far more types of cancer are due to “bad luck”–random stem cell mutations–than are caused by genetic or environmental factors, according to a study by researchers at the Johns Hopkins Kimmel Cancer Center.
The scientists, who published their report in the journal Science, used scientific literature to analyze 31 types of cancer. They evaluated the stem cell divisions in each type of cancer and compared these rates with the lifetime risk of developing these cancers. And they concluded that random DNA mutations during cell division may account for 65 percent of cancer types compared to 35 percent due to hereditary or environmental factors.
More specifically, the researchers say that cell mutations primarily accounted for 22 of the 31 types of cancer that were analyzed, including ovarian, pancreatic, bone and testicular cancer. Not surprisingly, environmental factors played a more significant role in certain cancers, such as lung cancer, tied to smoking, and skin cancer, linked to sun exposure.
The report also noted that while the majority of cancers are primarily caused by cell mutations, following a poor lifestyle can increase the chances of those mutations occurring.
Scientists able to induce REM sleep
A team of scientists in Massachusetts has been able to trigger REM sleep in mice by shining a light directly onto selected brain cells or neurons.
Using a technology called optogenetics, the researchers at the Massachusetts Institute of Technology and Harvard Medical School first inserted a a protein found in algae into the neurons they wanted to test so that they would be more responsive to light activation. Then, by shining a light on these light-sensitive neurons, they found they could increase the number REM sleep episodes in mice. The duration of the REM sleep episodes, however, could not be controlled.
Many drugs and sleep aids have not been able provide the same benefits humans get from natural sleep. But using techniques such as light activation may be a key development in finding ways to induce more natural sleep in humans.
First “Drunkometer”: Dec. 31, 1938
Thanks to the end of Prohibition and a boom in car sales, drunk driving had become a fast-growing problem in America in the 1930s. But on this New Year’s Eve, police in Indianapolis, Indiana went out armed with a new weapon to fight against people who had gotten behind the wheel after having too much to drink.
It’s a contraption called a “drunkometer” and it’s the invention of an Indiana University chemist named Rolla Harger. He had been working on the device since the early 1930s and had patented it two years earlier. The concept behind the drunkometer was pretty basic. Drivers suspected of being drunk were asked to breathe into a rubber balloon, which was attached to a tube of purple liquid—a weak solution of potassium permanganate in sulphuric acid.
If there was alcohol on their breath, the chemical solution changed color–the darker it got, the more alcohol they had in their system. From the shade of the liquid, the cops could use a simple equation to estimate the alcohol level in a person’s bloodstream. Previously, the only way police could check a driver’s alcohol level was to get a blood or urine sample; Neither was a very practical option on the roadside. While the drunkometer looked a bit like a mini chemistry set, it was portable, able to fit into a small suitcase.
Harger made the device as simple as possible so that judges and juries would understand how it worked and police officers could easily be trained to use it. He also made the drunkometer hard to beat. Experiments showed that no illness affected the result, and that nothing a person might eat - garlic, cloves, strong onions - would make any difference. Once police started using it, the drunkometer was found to have another advantage. A dramatic change in the color of the liquid could often make people admit how much they had drunk.
Sometimes Harger would ride along with the police to see how his invention was being used. What he discovered was that a lot more people were driving drunk than he ever imagined.
The drunkometer was used by police departments all over the country until the 1950s when it was replaced by the breathalyzer, invented by another Indiana University professor, Robert Borkenstein. The breathalyzer is a much smaller and more sophisticated device that uses infrared spectroscopy to measure blood alcohol levels.
According to the Centers for Disease Control and Prevention (CDC), the average drunk driver has driven drunk 80 times before his first arrest.
More slices of history
Specific type of bat may be source of Ebola epidemic
Researchers at the Robert Koch Institute in Berlin say that the source of the Ebola outbreak that has killed more than 7,000 people in Africa appears to be the free-tailed insectivorous bats. Previously, officials believed that people eating fruit bats may have been the cause. But after interviewing residents of the village of Meliandou, where the Ebola epidemic began, researchers found that fruit bats were an unlikely source. The first victim was a two-year-old boy, who transmitted the virus to his three-year-old sister and pregnant mother, all of whom died. If ingestion of fruit bats was the cause, adults would have been infected before or at the same time as the boy. The researchers also discovered that the boy played near a hollow tree which contained a free-tailed bat colony.
Researchers inspected bats and other wildlife in Meliandou as well as neighboring forests and found that that particular species of bats was the most likely source of the Ebola epidemic. Large mammal populations close to Meliandou were also monitored and no evidence of a link to the Ebola outbreak was found.
The Ebola epidemic has affected tens of thousands of people and killed 7,588 people. Several new Ebola vaccines have shown promise in Africa.
Binge drinking hurts immune system in young adults
Here’s yet another reason to avoid getting into a habit of binge drinking–it can impair your the functioning of your immune system, says a new study at Loyola University Chicago Stritch School of Medicine.
In order to evaluate the impact of binge drinking–defined as four drinks for women and five drinks for men over two hours–the researchers recruited eight men and eight women, with a median age of 27, and asked them to drink five shots of vodka within a two-hour period.
They then took blood samples of the participants 20 minutes after they reached peak intoxication. Initially, their immune systems “revved up,” but when more blood was taken two and five hours later, it showed that their immune systems were less active than when they wre sober.
Not only would this make people more likely to develop infections, but it would also reduce the ability of their bodies to recover from the kind of traumatic injuries often associated with binge drinking.
The study was published in the journal Alcohol. The researchers said they next will study how binge drinking may affect the ability of burn victims to heal.
Anxiety drugs may be overprescribed for older women
A lot of older Americans, particularly women, are still being prescribed sedatives and anti-anxiety medications for long periods, even though these drugs are meant for short-term treatment of anxiety and sleep problems.
A recent study, published in JAMA Psychiatry, found that in 2008, 12 percent of American women over 80 were taking benzodiazepines, usually the brands of valium and xanax. These drugs have been linked to an increased risk of both falls and dementia and, according to the American Geriatrics Society, should be avoided in the elderly.
The researchers also found that almost one-third of Americans between the ages of 65 and 80 used tranquilizers on a long-term basis–four months or more.
The researchers at Columbia University Medical Center pointed out that in addition to increasing the chance of falls and impaired thinking, these medications, if taken for long periods, are more likely to become habit-forming and cause serious withdrawlal symptoms if they’re discontinued.