Stanford University – IdeasXChange

Insulin resistance could be explained by gene

Azadeh Kojouri on October 6, 2016

New study finds the mechanism for insulin resistance leading to type 2 diabetes.

Earlier work by Joshua Knowles, MD, PhD, an assistant professor of cardiovascular medicine at Stanford, and his team showed the connection of a human gene, NAT2, variant with insulin resistance in humans.

The fact that type 2 diabetes was caused by insulin resistance was known to researchers for decades. However, the cause for this phenomenon was a mystery.

Insulin, a hormone secreted by the pancreas, helps fat and muscle cells take up glucose from the blood. Insulin resistance is caused when human cells don’t respond to insulin, resulting in the build up of glucose in the blood and subsequently leading to the production of even more insulin.

The cause of insulin resistance is starting to be untangled by a team led by Joshua Knowles. (Photo courtesy of: Stanford University)

“We’ve identified a mechanism for insulin resistance that involves a gene that ties insulin resistance to mitochondrial function, “ said Knowles.

Scientists at the Stanford University School of Medicine and the University of Wisconsin have begun to find the connections between a gene, mitochondria, insulin resistance, and how well the body’s metabolism functions in causing diabetes.

Suppressing a similar gene in mice called Nat1, causes metabolic dysfunction, such as lower insulin sensitivity and higher levels of blood sugar, insulin and triglycerides. In addition, mice without the Nat1 gene gained more weight and showed a decreased ability to use fat for energy.

This new study reveals that suppressing the expression of the Nat1 gene in mice hinders the function of mitochondria. These cell structures make ATP, the energy of cells, without which the cells cannot survive.

Individuals with Insulin resistance don’t necessarily develop type 2 diabetes. However, the condition will result in decreased uptake of sugar by muscle and fat cells leading to cardiovascular disease, inflammation, polycystic ovary syndrome, fatty liver diseases and other health conditions.

Severe Insulin resistance leading to damaged body tissues is common. A study in 2015 estimated that close to 35 percent of US adults are insulin-resistant to a degree to be at a higher risk for diabetes and cardiovascular disease.

Knowles said, the reasons for this skyrocketing increase in the US are poor diet and sedentary habits.

Mom’s voice stimulates a variety of regions in children’s brains

Azadeh Kojouri on May 19, 2016

According to a study by Stanford University School of Medicine, a greater area of children’s brains is activated by their mother’s voice than by the voice of women they don’t know.

Brain regions in children that are strongly activated by the voice of their mothers extend beyond auditory ares to include regions involved in emotion, reward processing, social functions, detection of what is personally relevant and face recognition.

The study found that the strength of connections between the brain regions stimulated by the voice of the child’s mother would predict the child’s social communication abilities.

“Many of our social, language and emotional processes are learned by listening to our mom’s voice,” said lead author Daniel Abrams, PhD, instructor in psychiatry and behavioral sciences. “But surprisingly little is known about how the brain organizes itself around this very important sound source. We didn’t realize that a mother’s voice would have such quick access to so many different brain systems.”

Many years of research has revealed children prefer their mother’s voice. In one classic study, one year old babies sucked harder on their pacifiers once they heard their mother’s voice as opposed to the voice of other woman.

Mother’s voice not only affects the auditory region in the brain of their children but also has an effect on other areas. (Photo courtesy of : www.freeimages.com)

However, the mechanism behind this inclination was not known.

“We want to know: Is it just auditory and voice -selective areas that respond differently, or is it more broad in terms of engagement, emotional reactivity and detection of salient stimuli?”, said senior author Vinod Menon, PhD, professor of psychiatry and behavioral sciences.

This study tested 24 children aged between 7 to 12 with an IQ of at least 80. Children were all raised by their biological mothers and did not have any developmental disorders. Before the brain scans the voice of each mother was recorded saying three nonsense word.

Menon said these nonsense words were used to prevent the activation of a whole different set of circuitry in the brain.

The voice of two mothers whose children were not included in the experiment were recorded to use as controls.

The brain scans, revealed that even from very short clips, less than a second long, the children could distinguish their own mother’s voices with more than 97 percent accuracy.

“The extent of the regions that were engaged was really quite surprising”, said Menon.

“We know that hearing mother’s voice can be an important source of emotional comfort to children,” said Abrams. “Here, we’re showing the biological circuitry underlying that.”

Children whose brains showed a stronger degree of connection between all the different regions while hearing their mother’s voices had the strongest social communication ability.

This finding shows increased brain connectivity between the regions, is a neural fingerprint for increased social communication abilities in children.

Menon said this finding is an important template to examine social communication defects in children with disorders such as autism.

“Voice is one of the most important social communication cues, It’s exciting to see that the echo of one’s mother’s voice lives on in so many brain systems.”

Study: Companies and environmentalists working together can slow deforestation

Azadeh Kojouri on March 2, 2016

According to a Stanford University study, collective efforts to reduce deforestation are more than twice as effective as “confrontational” programs implemented by either nongovernmental organizations or industry.

Various eco-certifications inform consumers of their impact on deforestation. However, there hasn’t been much research on their effectiveness up until now.

The study finds that these certifications have improved forest product sustainability to a great extent.

According to “Impacts of Nonstate, Market-Driven Governance on Chilean forests” published in “Proceedings of The National Academy of Sciences”, Market-driven attempts have reduced deforestation to a great extent, with multi-party collaborations having the greatest impact.

“Our research shows that these market-based conservation efforts have reduced deforestation in Chile,” said lead author Robert Heilmayr, a recent graduate from Stanford’s Emmett Interdisciplinary Program in Environment and Resources, in the paper “Impacts of Nonstate, Market-Driven Governance on Chilean forests” published in “Proceedings of The National Academy of Sciences”

A comparison on the conservation outcomes between CERTFOR, a largely industry developed certification program, Joint Solutions Project (JSP), an NGO-instigated deforestation moratorium and Forest Stewardship Council (FSC), a cooporation between industry and nongovernmental organizations, has provided insight into this issue.

FSC was most successful in reducing deforestation. (Photo Courtesy : www.morguefile.com)

While CERTFOR had 16 percent reduction in deforestation on average, JSP-only participants experienced an average reductions of 20 percent. With 43% reduction in deforestation, FSC resulted in the greatest success.

According to Heilmayr and co-author Eric Lambin,the George and Setsuko Ishiyama Provostial Professor in the School of Earth, Energy & Environmental Sciences, the balance between strict environmental requirements with cost-effective solutions was responsible for FSC’s leading success. This balance creates a notion among participants that their interests have been protected and hence they follow through on requirements.

The analysis also suggests in contrast to government policies, private and market-driven programs are better at lowering deforestation rates in places of high deforestation.

“Traditional conservation policies like national parks often protect remote, pristine locations,” Heilmayr said. “Agreements between companies and environmentalists can reduce deforestation in more threatened forests.”

“In the globalization era, deforestation is increasingly associated with consumption in distant, international markets,” said Lambin . “We need new approaches to environmental governance that regulate the impact of international actors.”

Quality of school impacts economic growth in developing countries: expert

Azadeh Kojouri on February 10, 2016

The quality rather the quantity of education will better a nation’s economy in the developing world according to a Stanford University expert.

“If there is going to be inclusive economic development across the world, attention must focus on school quality and having all students achieve basic skills,” wrote Eric Hanushek, a Stanford economist in a new study published in Science magazine.

The implications are more important for developing countries as these countries lack knowledge-based economies.

Many believe rates of school attendance, student enrollment and years of school to be major factors affecting the economy. However, economic growth is highly dependent on students’ basic skills in math and literacy.

Increasing human capital – the combined economic value of the skills, knowledge and experience within a community – has been misinterpreted in its implementation, according to Hanushek. He said it has led to policies looking to increase head counts, enrollment and retention in schools, ignoring important issues related to increasing skills and knowledge among students.

“We argue that too much attention is paid to the time spent in school, and too little is paid to the quality of the schools and the types of skills developed there,” Hanushek wrote with co-author Ludger Woessmann, an economics professor at the University of Munich.

The study indicates ‘knowledge capital’, cognitive skills of the population, rather than human capital of ‘school attainment’, the highest level of education completed, is the key factor in economic development. The study also finds student enrollment measures have no correlation to how much students are learning.

Track records show, leading world economies are changing to knowledge-based economies.

“They require both the skills to innovative and a highly skilled workforce to execute new designs. As economies move from agriculturally based to manufacturing based to knowledge based, the importance of cognitive skills becomes magnified,” he said.

He also added, job markets rapidly change in growing economies, requiring individuals to adjust to new demands.