Oxytocin May Help Rejuvenate Old Muscles

Posted July 21, 2014 by Jennifer Huber
Categories: Health

Tags: , , , ,

 

muscle cells of old and young mice

The left image shows healthy muscle tissue from a young mouse. The middle image demonstrates that the efficiency of muscle repair mechanisms decreases with age, resulting in a lower density of muscle fibers and increased scar tissue in an old mouse. Injecting oxytocin rapidly rejuvenates the old tissue, as shown on the right image. (Wendy Cousin and Christian Elabd)

From birth until about the age of 30, your muscles continue to grow larger and stronger. But at some point in your 30s, you begin to lose muscle mass and strength which in turn affects your coordination. As part of the natural aging process, this disease, sarcopenia, is most commonly seen in inactive people but it also affects those who remain physically active throughout their lives.

Now UC Berkeley researchers have discovered that oxytocin – the “trust hormone” associated with maternal nurturing, social attachments, childbirth and sex – may combat this age-related muscle wasting. Their new study was recently published in Nature Communications.

Role in Muscle Regeneration

Led by associate professor of bioengineering Irina Conboy, the researchers found in mice that oxytocin is required to maintain healthy muscles, but the level of oxytocin in the blood and the number of oxytocin receptors in muscle stem cells naturally reduce with age. For instance, old (18 to 24 months) mice were found to have 3 times lower circulating levels of oxytocin than young (2 to 4 months) mice.

The research team performed a series of experiments using young and old mice to better understand oxytocin’s role in muscle repair. They injected the mice daily with oxytocin (or a control solution) under the skin for nine consecutive days, while causing a muscle injury midway on day 4. The researchers found that the old mice that received the oxytocin were able to repair their muscle injury at a level comparable to the young mice – far better than the old control group that didn’t get oxytocin. Systemic administration of oxytocin appears to rapidly improve muscle regeneration by enhancing aged muscle stem cell proliferation.

In contrast, the young mice already had sufficient levels of oxytocin and efficient muscle regeneration, so the oxytocin injections had no significant effect. This is important since most molecules that boost tissue repair are also associated with an increased risk of cancer.

“This is good because it demonstrates that extra oxytocin boosts aged tissue stem cells without making muscle stem cells divide uncontrollably,” explained Wendy Cousin, a senior scientist in Conboy’s lab, in a press release.

The researchers also performed similar experiments using mice with an inactivated gene for oxytocin and control mice. At the young age of 3 months, the two groups of mice appeared to have comparable muscle mass and repair efficiency after a muscle injury. However, muscle atrophy and a significant decline in muscle regeneration were observed for the 1-year old adult mice with the disabled oxytocin gene, signifying premature aging due to a lack of oxytocin.

It is unclear how long it will take the researcher to move beyond mice studies to human use. However, oxytocin is already approved by the FDA for clinical use in humans for other applications. For instance, oxytocin is commonly used to help increase contractions and control bleeding during childbirth. So getting approval for human studies should be straightforward once the researchers are ready.

Conboy’s research team is ultimately interested in applications beyond just maintaining healthy muscles. For instance, they are also investigating whether oxytocin could become a viable alternative to hormone replacement therapy to impede the symptoms of male and female aging. They also believe that aging is the underlying cause of a number of chronic diseases, including Parkinson’s and Type 2 diabetes.

Oxytocin Hype

In fact, researchers around the world are studying the use of oxytocin for seemingly every condition imaginable, including using oxytocin nasal spray to alleviate symptoms associated with mental disorders such as autism, schizophrenia and dementia. However, this research currently demonstrates mixed and inconsistent results, particularly regarding oxytocin’s influence on social skills.

The current excitement about oxytocin, particularly as a remedy for autism, could lead to a dangerous situation given the widespread availability of oxytocin supplements – as an accelerator spray, sublingual liquid that is absorbed under the tongue, pills and mouth lozenges. It is important to consult with your doctor before taking oxytocin.

This is a repost of my KQED Science blog.

Bacteria Can Survive for Days inside Airplanes

Posted June 9, 2014 by Jennifer Huber
Categories: Health

Tags: , , , , ,

Girl in seat on commercial airplane (foilman).

If you’re traveling by air on your summer vacation, you may want to think twice about what surfaces you touch inside the airplane cabin. Or better yet, you may want to drive.

Disease-causing bacteria can linger for days on surfaces in airplane cabins, according to new research results from Auburn University, Alabama. The researchers obtained common materials from the airplane cabins of a major airline – armrest, plastic tray table, metal toilet button, window shade, seat pocket cloth, and seat leather. They tested how long bacteria could survive on these surfaces under the standard airplane cabin conditions of low humidity and room temperature, when no cleaning procedures were used.

Specifically, they studied the survivability of two common pathogens: methicillin-resistant Staphylococcus aureus (MRSA) and E. coli O157:H7. They found that MRSA lasted the longest on material from the seat-back pocket, surviving for 7 days. In contrast, E. coli O157:H7 lasted the longest on the armrest material, surviving for 4 days.

Staph skin infections, including MRSA, generally start as small red bumps that often resemble spider bites but these can quickly turn into deep, painful abscesses. Different types of staph bacteria are commonly found on the skin or in the nose of about 30% of the U.S. population, while only 2% of the population are asymptomatic carriers of MRSA. You can get MRSA through direct skin-to-skin contact with an infected wound or by sharing equipment that has touched infected skin. However, these staph bacteria are generally harmless unless they enter the body through a cut or wound, so doctors recommend that you keep wounds covered with dry, clean bandages until healed.

E. coli O157:H7 is a major health problem that affects over 70,000 Americans per year. It causes nausea, vomiting, stomach cramps, fever and bloody diarrhea. The infection can be spread from person to person by fecal contamination, but it usually comes from eating food contaminated with animal or human waste. Doctors recommend eating only well cooked foods, particularly hamburger, and drinking treated pasteurized fluids.

However, MRSA and E. coli O157:H7 are not the most commonly found pathogens on airplanes based on past research studies. For instance, other researchers analyzed samples of 61 commercial airplane air filters to identify all the bacteria present.

“ There have been sequencing studies examining the HEPA filters. And MRSA and E. coli are not the dominant organisms there,” explained graduate student Kiril Vaglenov at a press conference. “But we have to remember that MRSA are often found in humans. So there is a possibility that these pathogens would actually be present in an airplane.”

In addition to testing whether MRSA and E. coli O157:H7 could survive the environmental conditions of the airplane, the University of Auborn researchers also investigated how easily the pathogens could be transferred from each surface onto skin.

“You can divide these surfaces into porous and non-porous surfaces. And the porous surfaces will protect the bacteria more,” said James Barbaree, primary investigator of the study, at the press conference. They found that the bacteria live longer on the porous surfaces like seat-back pocket fabric, but these porous surfaces are less likely to transfer to humans via surface contact. Bacteria are more likely to transfer onto skin from non-porous surfaces, like airplane armrests and tray tables. This is good news for air travelers, since non-porous surfaces are easier to disinfect.

The study was not meant to scare people about the risk. Instead, the investigators wanted to identify potential pathogens and establish a baseline. Their next research challenge is to look at how to eliminate potential pathogens or at least reduce the risk of pathogen transfer from all airplane surfaces.

“We want to look at disinfectant procedures,” said Barbaree at the press conference. “We also want to see if we can put antibacterial compounds into some of the surfaces to try to minimize the existence of the organisms on airplanes.”

Meanwhile, good hygiene is the best way to protect yourself against germs while traveling: cleaning all surfaces with antibacterial wipes, using hand sanitizer after touching surfaces, and washing your hands frequently.

This is a repost of my KQED Science blog.

Prolonged and Heavy Bleeding is Common During Menopause Transition

Posted May 4, 2014 by Jennifer Huber
Categories: Health

Tags: , ,
Woman suffering through a bad menstrual period (bandita/Flickr).

Woman suffering through a bad menstrual period (bandita/Flickr).

I could hear the fear and panic in my friend’s voice over the phone. She was bleeding so heavily that she was debating whether to go to the emergency room, but she wanted my opinion. Was she over-reacting? Was this just a normal part of approaching menopause?

Since menopause is associated with women no longer getting their menstrual period, women transitioning into menopause are often frightened by unpredictable, prolonged or heavy bleeding. The results of a new research study may help alleviate their fears.

Menopause is when a woman stops producing reproductive hormones like estrogen, causing her ovaries to stop producing an egg each month. This occurs on average when a woman is 51 years old, but some women experience menopause in their 30s or 40s.

Perimenopause is the years leading up to menopause, when the body’s hormone levels are erratically fluctuating and dropping. This transition period typically lasts about 4 years, but it can last up to 10 years. During perimenopause, the reduction of reproductive hormones causes physical and emotional symptoms, including:

  • A change in periods – shorter or longer, lighter or heavier, more or less frequent
  • Hot flashes and/or night sweats
  • Trouble sleeping
  • Mood swings
  • Vaginal dryness

How periods change during perimenopause was the focus of a new research study, recently published in BJOG: An International Journal of Obstetrics and Gynaeocology. A collaboration of researchers from several medical institutions performed a long-term study on the bleeding patterns of perimenopausal women to determine what women normally experience.

The researchers used data from the Study of Women’s Health Across the Nation (SWAN), a multi-site longitudinal study of midlife women living in the US. They analyzed the data from the SWAN menstrual calendar substudy conducted from 1996 through 2006 at three locations – northern California, Los Angeles and southeastern Michigan. The research collaboration included investigators from all three regions: University of California Davis, University of California Los Angeles, University of Michigan School of Public Health and University of Massachusetts Medical School.

The participating women completed daily menstrual calendars and provided information monthly on hormone therapy, gynecological procedures, smoking and physical activity. Women taking hormone therapy or hormone birth control were excluded, since these affect ovarian function.

This was the first long-term study to include a large population of 1320 midlife women (aged 42-52) of multiple races: African-American, Japanese, Chinese and white. Previous studies were short and mostly limited to white women.

The researchers found that it’s common for women during perimenopause to experience prolonged bleeding for 10 or more days, spotting for six of more days and/or heavy bleeding for three or more days. Over 90% of the women experienced between one and three episodes of bleeding that lasted at least 10 days in the past three years, and 28% experienced three episodes within a 6-month period.

Similarly, 67% of the women experienced at least three occurrences of spotting for 6 or more days with 24% recording three episodes within a 6-month period. And 35% of women had at least three episodes of heavy bleeding that lasted three or more days, where heavy bleeding was defined as having to change a sanitary product every one to two hours for more than four hours per day.

Very few differences were seen between races. African-American women were less likely to bleed for 10 or more days or to spot for six or more days, compared to white women. And Japanese women were less likely to have three or more days of heavy bleeding, compared to white women.

The researchers hope that their study will help guide both clinicians and patients, by defining “normal” bleeding patterns for women during midlife.

“Women need more descriptive information about the bleeding changes they can expect,” said author and University of Michigan professor Sioban Harlow in a press release. “We need clear guidance to help women understand what changes in bleeding patterns do and do not require medical attention.”

Hopefully this will help concerned women like my friend, by educating them on what to expect.

How Damaged Is Your DNA?

Posted March 17, 2014 by Jennifer Huber
Categories: Health

Tags: , , , , , ,
Summary of the factors that cause DNA damage and the associated diseases. (Courtesy of Sylvain Costes)

Summary of the factors that cause DNA damage and the associated diseases. (Courtesy of Sylvain Costes)

DNA stores the genetic information in each living cell, so its integrity and stability is essential to life.

DNA is constantly being damaged by environmental factors like exposure to ionizing radiation, ultraviolet light and toxins. DNA replication is also prone to error during normal cell division. So your body is busy constantly repairing damaged DNA. However, sometimes this normal DNA repair process fails, causing DNA damage and genetic mutations to accumulate which leads to serious health problems like cancer, immunological disorders and neurological disorders.

If your annual checkup included a simple blood test to determine how much DNA damage you have in your body, you may be able to optimize your long-term health by taking action to minimize DNA damage due to your diet, exercise and environment.

A start-up company called Exogen Biotechnology wants to provide the public with a way to monitor their DNA health, so they can act to reduce their DNA damage. Exogen has developed technology that can rapidly quantify a type of DNA damage called double-strand breaks.

“DNA double-strand breaks are when the two strands of the DNA are cut, so they can move apart,” explained Sylvain Costes, a Staff Scientist at Lawrence Berkeley National Laboratory and co-founder of Exogen.  “This is linked to mutation and chromosome rearrangement, so it’s a big deal – it’s the dangerous type of DNA damage. That’s what we look at.”

Exogen’s DNA damage measurement is based on technology developed over 15 years ago called immunocytochemistry – a technique that uses a primary antibody that recognizes the protein that is repairing the DNA break, along with a secondary fluorescent antibody that binds to the primary antibody. This creates bright spots in the microscope image where there are double-strand DNA breaks, so scientists can take a picture and count the breaks.

Exogen is moving this technique out of the laboratory to make it publicly available. They have significantly improved the technology, so that it’s feasible to rapidly test small blood samples for the level of DNA double-strand breaks. A customer collects tiny blood samples using an in-home kit, combines the blood samples with a fixative solution to preserve them, logs on to the Exogen website to register the samples and complete the questionnaire, and mails the samples to Exogen for analysis.

Exogen tested their new technology in two pilot studies with a total of 97 people. They observed a significant increase in the level of DNA damage with age, where 70 year olds had double the number of DNA double-strand breaks compared to 20 year olds. The four people who had suffered from cancer also had a higher level of DNA damage compared to others in their age group.

“When we did the first pilot study, we saw the excitement of the people,” said Costes. “They realized that this is something totally new; something we know in the research field, but that’s never been given to the people.”

Inspired by the initial pilot studies, Exogen wants to build a large database of DNA damage levels for research purposes so they can better understand the meaning of an elevated level of DNA damage and how certain factors affect DNA health. Of course, their data collection process and database are secure, encrypted and fully HIPAA compliant.

In order to get the necessary blood samples, they are currently running a crowdfunding campaign on Indiegogo. People that donate $99 receive a kit to safely collect three blood samples at home, and then they receive a report on their current level of DNA damage. Exogen is calling the campaign a “citizen science project” since volunteers also fill out questionnaires about their medical history and lifestyle. They’ve already collected $76,000 and the crowdfunding campaign runs through March 26. They plan to spend the money on a microscope and liquid handler, which will allow them to fully automate their system so they can analyze up to 400 blood samples per day.

Currently, Exogen can’t interpret the results or give people advice about how to lower their DNA damage, because the Food and Drug Administration (FDA) hasn’t approved them as a diagnostic test. The goal of the crowdfunding campaign is to collect blood samples from 1000 people so they can go to the FDA.

“Once we have FDA approval, we can start counseling,” said Costes. “Primary care doctors can start engaging and testing it further with their patients, because we’ll provide a guideline to help them understand what it means.”

Costes stressed that their test is very different from genetic testing provided by companies like 23andme. Exogen isn’t looking at the genetic makeup. Instead, they are looking at a physiological response, so they compare it to a cholesterol test.

“To me this is identical to cholesterol,” clarified Costes. “Your genetics places you in a certain range, but your lifestyle can change where you are within that range. In contrast to genetic testing, we feel like this test can bring hope because you have a way to act.”

One of their applications is to determine how DNA damage is affected by lifestyle factors like diet.  Exogen plans to study a group of people for a long time to better understand how DNA damage correlates with specific diseases and with health improvements due to people’s actions. They want to evaluate whether people can improve their DNA health by changing their lifestyle or environment, instead of their fate being driven entirely by genetics.

However, none of the exciting applications can happen until Exogen collects data from a larger number of people. “We need your help to make it happen,” Costes concludes. “We can’t do it alone.”

This is a repost of my KQED Science blog.

Don’t Depend on Diet Drinks To Lose Weight

Posted February 24, 2014 by Jennifer Huber
Categories: Health, Nutrition

Tags: , ,
boxes of diet Coke

Photograph courtesy of Beau B via a Creative Commons license.

Beverages like soda, sports drinks and energy drinks are loaded with sugar and empty calories. Soda is the number one source of added sugar in the American diet, which isn’t surprising since a 20-oz bottle of soda contains about 17 teaspoons of sugar.

So it makes sense that overweight people often turn to diet drinks to help them slim down. But recent research suggests that this weight-loss tactic may backfire.

Researchers from the Johns Hopkins Bloomberg School of Public Health studied the patterns in diet drink consumption and calorie intake among US adults of various body-weight categories. Their results were recently published in the peer-reviewed American Journal of Public Health.

They analyzed data obtained from the National Health and Nutrition Examination Survey (NHANES), which is a population-based survey designed to collect information on the health and nutrition of the US population. The researchers used the NHANES data collected from 1999 through 2010. The study sample consisted of 23,965 adults who reported all of the food and beverages that they had consumed in the previous 24 hours.

The study found that overweight and obese adults drink more diet beverages than healthy-weight adults. Overall, 11% of healthy-weight, 19% of overweight and 22% of obese adults drink diet beverages. This suggests that overweight and obese people may indeed switch to diet drinks to reduce their calorie intake when trying to control or reduce their weight.

Unfortunately, the researchers also found that the overweight and obese diet drinkers made up the calories by eating significantly more food during meals and snacks, in comparison to overweight and obese adults who drank sugar-sweetened beverages. The net increase in daily food consumption associated with diet drink consumption was 88 calories for overweight and 194 calories for obese adults.

In comparison, healthy-weight diet drinkers ate less food calories  – 73 less calories per day – than their counterparts who drank sugar-sweetened beverages.

High doses of artificial sweeteners are found in diet drinks. Earlier research found that the regular consumption of these artificial sweeteners alters the reward a person experiences from sweet tastes and disrupts appetite control. This could explain why the heavy adults who drank diet beverages ate more food calories. But it doesn’t explain why this wasn’t the case for healthy-weight diet drinkers.

Further research is needed to understand both the biological and psychological response to regularly drinking diet beverages with artificial sweeteners. But it is clear that you aren’t going to drop pant sizes by simply switching from Coke to Diet Coke.

“Heavier adults who drink diet beverages will need to reduce their consumption of solid-food calories to lose weight,” concluded the Johns Hopkins researchers. “More research is needed to identify and promote concrete behavioral targets.”

This is a repost of my KQED Science blog.

Science at the Theater: Next Big Tech Idea

Posted February 21, 2014 by Jennifer Huber
Categories: Event, Science Education

Tags: ,

LBNL-logo_BluewWhite

You be the judge! Help pick the next big tech idea that will benefit society.

Five scientists will pitch their technology ideas at the next Science at the Theater, a free public lecture hosted by Lawrence Berkeley National Laboratory. It will be held on Monday, February 24 at 7 pm at the Berkeley Repertory Theater.

The audience and a panel of judges will listen to the scientists’ technology pitches, then vote on which one will help society the most. The topics  that will be discussed are:

  • “Making Better Batteries” by Guoying Chen, Chemist
  • “Tracking and Hacking Personal DNA Damage” by Sylvain Costes, Biohysicist
  • “Making Energy Measurement Stick ” by Steven Lanzisera, Applied Energy Scientist
  • “Molecular Velcro” by Gloria Olivier, Chemist
  • “Dress Code for Martians” by Alex Zetti, Physcist

Free reservations for the event are still available. But hurry, because these events usually fill up.

Expand Your Horizons

Posted February 18, 2014 by Jennifer Huber
Categories: Event, Science Education

Expanding Your Horizons logo

It isn’t too late to sign up for an upcoming Expanding Your Horizons conference. These conferences are designed to inspire middle and high school girls to careers in science, technology, engineering and mathematics. The girls participate in fun hands-on activities led by women role models. For instance, they can spend the day building lego robots and participating in a robot demolition derby.

There are also workshops for parents, including discussions on how best to support your daughter throughout her schooling.

UC Berkeley’s Expanding Your Horizons conference will be held on March 15, 2014 and registration is still open for girls, parents and volunteers. There are also conferences at other Bay Area locations in the spring and fall.


Follow

Get every new post delivered to your Inbox.

Join 65 other followers

%d bloggers like this: