Monthly Archives: April 2017

Scientists Have Removed Heart Disease Defects on Human Embryos

A group of scientists in Oregon has successfully modified the genes of embryos using CRISPR, a cut-and-paste gene-editing tool, in order to correct a genetic mutation known to cause a type of heart defect.

The experiments, which were described today (Aug. 2) in the journal Nature, were conducted by biologist Shoukhrat Mitalipov and colleagues at Oregon Health & Science University in Portland. Mitalipov conducted the experiments on dozens of single-celled embryos, which were discarded before they could progress very far in development, MIT Technology Review reported last week when the results were initially leaked. This is the first time that scientists in the United States have used this approach to edit the genes of embryos.

The CRISPR/Cas9 gene-editing system is a simple “cut and replace” method for editing precise spots on the genome. CRISPRS are long stretches of DNA that are recognized by molecular “scissors” called Cas9; by inserting CRISPR DNA near target DNA, scientists can theoretically tell Cas9 to cut anywhere in the genome. Scientists can then swap a replacement gene sequence in the place of the snipped sequence. The replacement sequence then gets automatically incorporated into the genome by natural DNA repair mechanisms.

In 2015, a group in China used CRISPR to edit several human embryos that had severe defects, though none were allowed to gestate very long before being discarded. The Chinese technique led to genetic changes in some, but not all of the cells in the embryos, and CRISPR sometimes snipped out the wrong place in the DNA.

The new results are a major advance compared with earlier efforts. In the new experiments, scientists eliminated the off-target effects of CRISPR/cas9.

The team used dozens of embryos that were created for in vitro fertilization (IVF), using the sperm of men who had a severe genetic defect. The sperm contained a single copy of the gene MYBPC3, which confers a risk of sudden death and heart failure due to thickening of the heart muscle known as hypertrophic cardiomyopathy.

In the new experiment, the team used Crispr/Cas9 to snip DNA at the location of the defective MYBPC3 gene in the fertilized eggs. Most of the embryos naturally repaired the break in the DNA by substituting the normal version of the gene, which originated in the egg. About two-thirds of the embryos did not contain the mutated version of the gene; and the team also eliminated the risk that some, but not all, of the cells in the embryos contained the edited genes.

In general, editing the germ line — meaning sperm, eggs or embryos — has been controversial, because it means permanently changing the DNA that is passed on from one generation to the next. Some scientists have called for a ban on germ-line editing, saying the approach is incredibly risky and ethically dubious.

However, a National Academy of Sciences report published earlier this year suggested that embryo editing could be ethical in the case of severe genetic diseases, assuming the risks could be mitigated.

Swipe left for sadness: Reminder users report more grief

Swiping through Tinder may be taking a toll on your mental health and self-esteem: A new study finds that Tinder users had lower levels of self-esteem and more body dissatisfaction than people who didn’t use the dating app.

The reason may have to do with the fact that a person’s looks play a major role in Tinder. People accept or reject potential matches based primarily on photos, and sometimes, a short description. And this type of judgment can take a toll, the study found.

Both male and female Tinder users in the study experienced low self-esteem, body shame and negative moods, said lead study author Jessica Strubel, an assistant professor of textiles, merchandising and design at the University of Rhode Island, whose research includes looking at the effects of body image on decision-making. [13 Scientifically Proven Signs You’re in Love]

Strubel has studied the links between Tinder and self-esteem before. In astudy published online earlier this year, she found that male Tinder users had lower self-esteem than men who weren’t on the app.

In the new study, which was presented here today (Aug. 3) at the American Psychological Association’s annual meeting, Strubel and her team again looked at college-age Tinder users — more than 700 female and 120 male students.

Ultimately, they found the same thing as the previous study, with one difference, Strubel told Live Science: Both men and women had similar negative responses, she said. The new study also looked at more factors, including whether Tinder use was associated with a person’s mood and eating habits.

In addition to providing information about their Tinder use, the people in the study also answered questions about their mood, level of body satisfaction, self-esteem, perceived societal pressures to look a certain way and body shame.

About 17 percent of the people in the study used Tinder. Compared with those who didn’t use the app, Tinder users were more likely to report negative feelings. For example, relative to nonusers, Tinder users were more likely to compare themselves to others, feel pressures to look a certain way and experience negative moods.

The researchers also looked at whether Tinder users were more likely to change their eating habits, or “dietary intent.” Here, however, they found no difference between users and nonusers. Dietary intent is related to a person’s body satisfaction, Strubel said. If a person isn’t happy with their body, what will the subsequent behaviors be? she said. But in this case, the findings showed that just because a person is dissatisfied doesn’t necessarily mean that they’re going to change their eating habits.

Still, Strubel stressed that she’s not telling people to stop using Tinder. “I understand … this is the dating world now,” she said. “But we can’t deny what the science says: There are some psychological ramifications to this.”

To limit the possible negative effects of using Tinder, Strubel recommended keeping things in perspective when using the app. For example, keep in mind that the photos you see of others don’t always represent reality; instead, they show a person at their very best.

After Terrorist Attacks, Too Much TV Can Be Dangerous

During a terrorist attack, it may be best to avoid wall-to-wall news coverage, a new study suggests.

Watching television news coverage during terrorist events was associated with higher levels of post-traumatic stress and feelings ofdepression as well as decreased feelings of safety, the researchers found.

In the study, which was presented here today (Aug. 3) at the annual meeting of the American Psychological Association, the researchers focused on a terrorist event that captured news coverage in 2002: a series of sniper attacks in the Washington, D.C., area that killed 10 people and left three others wounded. Local media covered the events extensively as they unfolded. [7 Ways Depression Differs in Men and Women]

“We understand that [the] media plays a critical role in people’s feelings of safety or feelings of threat in the environment,” said lead study author Holly Mash, a research assistant professor of psychiatry at the Uniformed Services University of the Health Sciences in Bethesda, Maryland.

Mash and her colleagues had more than 1,200 people complete online questionnaires about their moods and feelings during the sniper attacks. In addition, the researchers collected data on how much sniper-related TV the people watched each day. The surveys were conducted three weeks after the initial attack but before the two perpetrators were caught.

About 40 percent of the people who completed the surveys reported that they watched at least 2 hours of sniper-related TV each day during the course of the attacks, which lasted for about three weeks, the researchers found.

And the more television a person watched, the more likely the individual was to report symptoms of post-traumatic stress and depression, Mash said. Post-traumatic stress symptoms include negative thoughts,nightmares and avoidance behavior. Depressions symptoms include depressed mood, trouble concentrating, difficultly sleeping and lack of interest in things the person typically enjoys.

The researchers thought that the post-traumatic stress and depression symptoms could stem from feeling less safe, Mash told Live Science. In other words, the less safe a person feels, the more likely he or she is to report symptoms of post-traumatic stress or depression.

And watching more sniper-related TV coverage was also associated with decreased feelings of safety, the researchers found.

Though the study focused on an event that took place in 2002, Mash noted that constant media coverage of terrorist attacks has become a bigger issue since that time. In addition to television coverage, there’s constant internet coverage, which can include unfiltered and sometimes incorrect information, she said.

The findings have implications for media exposure, Mash said, adding that she recommends limiting exposure to only pertinent information about an attack. Still, “that’s tough,” she added.

Friends with Ex Check Your First Motive, Science Says

Can you really stay friends with an ex? It depends on why you want to continue the relationship, a new study finds.

Staying friends with an ex is a “very pervasive phenomenon,” said lead study author Rebecca Griffith, a master’s student in psychology at the University of Kansas. Indeed, previous research suggests that about 60 percent of people maintain a friendship after a breakup, Griffith said.

But these friendships aren’t always successful.

In the study, the researchers developed a way to examine the reasons why a person might stay in a friendship after ending a romantic relationship. In one experiment, which included more than 170 women and more than 110 men, the researchers tried out this new measurement technique, which consisted of several questionnaires. In a second experiment, with nearly 300 women and nearly 250 men, the researchers confirmed that the questionnaires worked. [The Science of Breakups: 7 Facts About Splitsville]

The researchers found that are four main reasons that someone stays friends with an ex after a breakup, said Griffith, who presented the study here on Aug. 4 at the American Psychological Association’s annual meeting.

The first reason is security, Griffith told Live Science. This could mean that a person stays friends with an ex because he or she doesn’t want to lose the ex’s emotional support, advice or trust.

The second reason is that it’s practical to maintain a friendship: Perhaps there are financial reasons to stay friends, or children may be involved, Griffith said.

Third, there’s civility. A person may want to be polite and not hurt the other persons’ feelings, Griffith said.

Finally, some people may still have romantic feelings for an ex.

The researchers found that the reason people choose to remain friends is associated with how long the friendship will last and how positive it will be.

People who stayed friends for practical and civility reasons fared the best, the study found. These friendships lasted long and were considered to be positive, Griffith said. (A positive relationship meant that the friendship made a person feel secure and happy, and a negative relationship meant the person had negative feelings including depression, jealously or a broken heart.)

When people remained friends for reasons related to security, the resulting friendships tended to be positive, the study found. However, security reasons weren’t associated with whether the friendship lasted for a long or short period of time.

As for unresolved romantic desires, this reason was associated with more negative feelings, but “paradoxically,” longer friendships, Griffith said. In other words, “even though you’re not reaping any benefits from the friendship, you tend to stay in [it] longer,” she said.

Broadly speaking, two of the reasons that a person may stay friends with an ex are related to emotional needs (security and unresolved romantic desires) and two of the reasons are not (practical reasons and civility), Griffith said. It’s the non-emotional reasons that are ultimately linked to a more successful friendship, she said.