Human cartilage grown on a lab chip
Scientists have for the first time grown living human cartilage on a laboratory chip and say that it could eventually be used to replace damaged or deteriorated cartilage for people with osteoarthritis or soldiers with battlefield injuries.
Researchers from the University of Pittsburgh School of Medicine used human stem cells, a scaffold and biological factors to make the stem cells grow into cartilage. While providing growth factors to the stem cells, they used the scaffold to give the cartilage the desired shape and structure. One of the factors which made the experiment successful was that the researchers used visible light to grow the stem cells, whereas previous experiments required UV light, which can harm living cells.
By growing the human cartilage on a laboratory chip, the researchers said they will be able to examine how cartilage disintegration—a marker of osteoarthritis—occurs and develop new drugs to treat it. Osteoarthritis is one of the leading causes of physical disability in the United States and currently has no cure.
The ultimate goal, the researchers said, is to be able to allow doctors to create on a 3-D printer new cartilage to fit where it’s needed on a patient’s body.
Low exposure to rural microbes raises risk of asthma, allergies
People who live in urban areas may be more at risk of asthma and allergies, due to lower exposure to “healthy microbes” found in rural settings, according to new research.
A team of researchers from the University of Colorado Boulder aimed to find an explanation for previous studies that have determined that people of lower socioeconomic status are more prone to asthma, allergies and other inflammatory disorders. The Colorado researchers focused on the effect of certain microbes and infections—particularly those that have existed for many years—and found that they have an anti-inflammatory effect and can suppress the kind of inflammation that can cause asthma and allergies.
The findings, published in the journal Clinical & Experimental Immunology, showed that while the beneficial anti-inflammatory microbes exist today in rural areas, they are largely absent in most developed areas. Because people of lower socioeconomic status typically live in urban areas, they are less exposed to the rural microbes and therefore are more prone to inflammatory diseases, researchers said.
The scientists concluded that because it’s not realistic to expect people in cities to increase their exposure to rural microbes, they should instead focus on reducing their exposure to modern diseases by paying close attention to hygiene issues.
Drinking more coffee could lower diabetes risk
Drinking more coffee consistently could reduce risk of type 2 diabetes, according to new research.
Scientists from Harvard School of Public Health collected observational data from three large prospective studies conducted in the U.S. Collectively, the studies provided data on diet, lifestyle, medical conditions and chronic diseases among adults over the course of 20 years. Using the data, the researchers were able to analyze the effects of coffee consumption during a four-year period.
The researchers found that the participants who increased their coffee intake by on average one-and-a-half cups per day for four years reduced their risk of type 2 diabetes by 11 percent in the subsequent four years, compared to those who made no changes in coffee consumption. They also found that the participants who decreased their coffee intake by on average two cups per day increased their risk of type 2 diabetes by 17 percent. The “high-stable consumers”—people who consistently consumed three or more cups of coffee per day—had the lowest risk of type 2 diabetes, which was 37 percent lower than that of “low-stable consumers”—people who consistently consumed one cup or less per day. The results applied only to caffeinated coffee and did not apply to tea or decaf coffee.
The findings, published in the journal Diabetologia (the journal of the European Association for the Study of Diabetes) add to previous evidence that coffee consumption habits are related to diabetes risk.
Scientists say "female intuition" may begin in womb
Exposure to testosterone in the womb may predispose people to either a more intuitive or reflexive mindset as an adult, according to a new study.
Scientists from the University of Granada, the Barcelona Pompeu Fabra University and the Middlesex University of London focused on the effects of prenatal testosterone exposure on intuitive thought—defined as the processing of information automatically and unconsciously, requiring little cognitive effort and sometimes referred to as “female intuition.” The researchers recruited more than 600 students from the University of Granada Faculty of Economics and Studies.
First, in order to determine how much testosterone the students were exposed to in the womb, the researchers used a method called the second-to-fourth digit ratio, which works by dividing the length of the forefinger by the length of the ring finger on the same hand. Researchers said that this method is a widely accepted marker for prenatal testosterone exposure, and it is understood that the lower the ratio, the greater the amount of prenatal testosterone exposure and the less intuitive the cerebral disposition. Men tend to have a lower average second-to-fourth digit ratio and therefore are less intuitive, researchers said.
The study’s participants then took a cognitive reflection test (CRT). In order to score well on a CRT, the test taker must be able to recognize that the first answer that jumps into his or her head is incorrect, and then override the intuitive response with one based on more reflection. Previous studies have shown that men generally score better on a CRT because they are more likely than women to respond in a reflexive way, rather than in an intuitive way.
The results, published in the journal Psychoneuroendocrinology, found that the women who had a lower—or more “masculine”—digital ratio than their female counterparts performed as well as the men did on the CRT. The findings suggest that women in particular who have relatively high prenatal exposure to testosterone may be predisposed to having less intuition and a more reflexive mindset, the researchers concluded.
Walking boosts creative thinking
Walking more may help stimulate a person’s ability to think creatively, concludes a new study from Stanford University.
Scientists recruited 176 college-aged adults and had them take a test of their divergent thinking creativity—the ability to generate ideas by thinking of multiple possible solutions. The test entailed thinking of multiple uses for different objects under a time limit. Test scores were based on novelty—whether other participants thought of the same idea—and appropriateness—whether the ideas were realistic.
The researchers had the study’s participants take the test while walking or sitting under various conditions. The subjects either walked outdoors or indoors or were pushed in a wheelchair for between five and 16 minutes.
The results of the study showed that the majority of the participants scored an average of 60 percent higher on the test when they were walking rather than sitting. Researchers said that creative thinking seemed to be boosted while walking either outdoors or indoors and also that creative thinking levels remained elevated for a period of time after a walk.
The study’s findings, published in the Journal of Experimental Psychology: Learning, Memory and Cognition, provided more evidence of the importance of fitting physical activity into the day. Researchers are now planning to investigate why walking seems to only benefit the thought processes involved in divergent thinking.
First U.S. heart transplant: May 3, 1968
Dr. Denton Cooley, already recognized as a top-notch heart surgeon makes history when he performs the first heart transplant in the U.S. at St. Luke’s Hospital in Houston, Texas. The patient is a 47-year-old man named Everett Thomas who’s dying of a rheumatoid heart condition, the donor, a 15-year-old girl who had committed suicide. Though her brain had stopped functioning, the teenager’s heart is still beating and Cooley moves quickly to transfer the organ.
The procedure worked well enough for Thomas to leave the hospital and live for another seven months. And although the world’s first heart transplant had actually occurred in South Africa the previous December, Cooley rapidly became a leader in the revolutionary surgery, performing 22 more transplants over the next year, including three within one five-day period.
Cooley had already refined surgical techniques to correct congenital heart anomalies in infants and children, to bypass clogged coronary arteries and to repair aortic aneurysms. He had helped perfect methods for repairing and replacing diseased heart valves. He also helped develop the heart/lung machine, which makes modern cardiac surgery possible.
In 1969, he took another groundbreaking step, performing the world’s first operation in which an artificial heart was implanted in a human—a suitable heart wasn’t available. The patient lived only 65 hours, but Cooley was celebrated as a cardiac surgery pioneer.
He did, however, come under harsh criticism from his former associate, Dr. Michael DeBakey, another world-renown surgeon who felt that Cooley had unethically used an artificial heart that the two of them had developed together. That sparked one of the medical community’s most famous feuds—the two didn’t speak for almost 40 years, making up just a year before DeBakey died at the age of 99 in 2008.
From the 1960s through the turn of the 21st century, Cooley and his team at the Texas Heart Institute, which he opened in Houston, performed more than 100,000 open heart surgeries. Cooley himself personally repaired 12,000 aortic aneurysms during his career. His autobiography, published in 2012, is titled “100,000 Hearts: A Surgeon’s Memoir.”
Once, when testifying at a trial, a lawyer asked Cooley if he considered himself the best heart surgeon in the world. When he answered, “Yes,” the attorney replied, “Don’t you think that’s being rather immodest?” To which Cooley responded, “But remember I’m under oath.”
During the 2000 U.S. presidential election, George W. Bush asked Cooley to review the medical records of vice presidential candidate Dick Cheney, who had a long history of heart problems. Cooley said Cheney could handle the role.
Today, about 3,500 heart transplants are done every year, most of them—2,000 to 2,300—in the U.S. And the survival rate continues to increase. Now about 73 percent of male heart recipients live at least five years; the figure for women is slightly lower, about 69 percent. The longest living heart transplant patient was Tony Huesman, who died of cancer in 2009, 31 years after receiving his heart.
Among the recipients of a heart transplant in 2012 was the man whose records Cooley had checked out in 2000–former Vice President Dick Cheney.
Cooley didn’t put down his scalpel until his 87th birthday. Now 94, he still lives in Houston.