Life Lines - The Podcast of The American Physiological Society

What would it be like to live without being able to detect any odors? For one thing, Thanksgiving would be much less enjoyable, perhaps disturbingly so. In this episode, we talk to Robert I. Henkin of the Taste and Smell Clinic in Washington, D.C., who will tell us why people lose their sense of smell and how his research can help some people restore it. (Begins at: 02:03)The Buzz in Physiology features studies on a simple test that may determine arterial stiffness in adults older than 40, and a look at a 1950s program that tested the fitness of women to become astronauts. (Begins at: 00:43)

Dean Franklin developed the first instruments to measure blood flow and the changes in diameter of the pulsating heart in conscious animals. He also pioneered the use of radio waves to measure heart and blood vessel function without wiring the body to the instrument. Dusty Sarazan, a former student of Dean Franklin, explains how these inventions led to the non-invasive cardiovascular monitoring instruments we have today. You can find the full article on Dean Franklin here and a press release here. (Begins at 02:22)A program note: We misspoke when we mentioned that physiologists made an important discovery after a giraffe frightened an instrumented baboon. In fact, a leopard had frightened the baboon.The Buzz in Physiology(Begins at 00:52) A study on how exercise helps prevent weight regain after dieting finds that exercise reduces the drive to overeat, causes the body to burn fat before burning carbohydrates and prevents an increase in the number of fat cells during weight regain.A study on how alcohol can disrupt circadian rhythm finds that chronic drinking blunts the biological clock's ability to synchronize daily activities to light, disrupts natural activity patterns and continues to affect the body's clock even days after the drinking ends.

You've heard the word telecomm? In this episode, we are going to coin a new word: elecomm, shorthand for elephant communication. Caitlin O'Connell-Rodwell is a Stanford University professor and the author of The Elephant's Secret Sense, published by the University of Chicago Press. Dr. O'Connell-Rodwell discovered that elephant vocalizations travel through the ground, sometimes for great distances. Other elephants pick up these seismic communications and understand them. There are links to videos of three of Dr. O'Connell-Rodwell's elephant communication experiments on her website, www.utopiascientific.org or by clicking here, here and here. (Begins at 2:44)From the Buzz in Physiology (Begins at 1:13): Divers who held their breath for several minutes had elevated levels of S100B (a protein found after cell injury) in their bloodstream, which suggests that holding one's breath for a long time disrupts the blood-brain barrier. However, the appearance of the protein was transient and leaves open the question of whether lengthy breath holding can damage the brain over the long term, according to the Lund University researchers.And drinking beetroot juice boosts stamina and could help you exercise for up to 16% longer, according to a study from the University of Exeter. The study shows how the nitrate contained in the juice leads to a reduction in oxygen uptake, making exercise less tiring.You can read the press releases on these studies: FreedivingBeetroot

There is nothing like a good laugh, is there? It not only feels great to laugh, it can feel great to hear other people laugh. Beyond brightening the mood, can laughter provide tangible health benefits?Lee Berk of Loma Linda University in California has done a series of studies on laughter and its possible physiological effects. We will talk to him about his latest study, done over the course of a year with diabetic patients. (Begins at 3:50)In this month’s Buzz in Physiology (begins at 0:51), we look at studies that provide possible explanations for:

1. Why pregnant Andean give birth to larger babies at high altitude, compared to European women
2. How certain side effects in some medical procedures may trace back to a solvent found in plastic tubing

Total Time: 9:47

Celiac Update. Celiac disease is an uncontrolled immune response to wheat gluten and similar proteins of rye and barley. In those who have celiac disease, gluten can damage the small intestine, inhibit nutritional uptake and lead to malnutrition. Among the symptoms are diarrhea, stomach pain, fatigue, weight loss and slow growth. One study estimated that 1 in 133 people in the U.S. population have celiac disease. Many people do not know they have it, sometimes because there are no symptoms. Because celiac disease has a genetic component, there can be a much higher prevalence of the disease within families.Three years ago, a group of Dutch researchers led by Frits Koning of the Leiden University Medical Center published a study on an enzyme that showed promise as a treatment for celiac disease. The enzyme, prolyl endoprotease, or PEP, could quickly break down gluten in the stomach before it ever reached the small intestine, where it causes damage. In this episode, we ask Frits Koning to update us on his research. (Begins at 2:45)Total Time: 11:20