Prescription Drug Take-Back Day

prescription bottles
Photograph courtesy of joguldi via a Creative Commons license.

Do you have expired or unused prescription drugs stacked up in your medicine cabinet? It’s not safe to flush them down the toilet or throw them out with the trash. But you can get rid of them safely, easily and for free at sites across the US tomorrow. Yep, it is National Prescription Drug Take-Back Day on Saturday October 26 from 10 am – 2 pm. Drop them off at a local collection site.

Infections During Pregnancy May Increase Autism Risk

B&W photograph of pregnant woman sitting on couch
Photograph courtesy of Stuart Handy via a Creative Commons license.

Every day our brains help us make sense of the world around us, interpreting the things we see, hear, taste, touch, smell and experience. But if someone’s brain has trouble processing this incoming information, it can be hard to communicate, understand or learn.

Autism spectrum disorders (ASD) are characterized by difficulties in social interaction, verbal and nonverbal communication, and repetitive behaviors. These disorders include autism, Asperger syndrome and Pervasive Developmental Disorder-Not Otherwise Specified.

About 1 in 88 children have been identified with an autism spectrum disorder and over 2 million people are affected in the United States, according to the Centers for Disease Control and Prevention. Government statistics also suggest that the proportion of people with autism spectrum disorders have increased 10 to 17 percent annually in recent years. This is in part due to wider awareness and better screening, but the continued increase is not fully understood.

The cause of ASD is also not fully known, but current research indicates that it is likely due to a complex combination of genetic predisposition and environmental risk factors that influence early brain development. Significant environmental risk factors include the advance age of either parent at the time of conception, maternal illness during pregnancy, extreme prematurity, and very low birth weight.

Over 40 years ago, epidemiological studies determined that the risk of having a child with ASD is increased when the mother has an infection early in the pregnancy. Since a wide range of bacterial and viral infections can increase the risk, studies suggest that activation of the mother’s general immune system is responsible. However, scientists do not completely understand how the activated immune system can disrupt normal brain development to cause ASD.

Research at the University of California Davis Center for Neuroscience provides new insight. Recently published in the Journal of Neuroscience, their studies identify a new biological mechanism that links maternal immune activation to neurodevelopmental disorders.

Kimberley McAllister, a senior author of the study, explained in a press release, “This is the first evidence that neurons in the developing brain of newborn offspring are altered by maternal immune activation. Until now, very little has been known about how maternal immune activation leads to autism spectrum disorder and schizophrenia-like pathophysiology and behaviors in the offspring.”

The researchers studied pregnant mice with immune systems that were activated halfway through gestation compared to pregnant control mice without activated immune systems. They found that the mice exposed to a viral infection had offspring with dramatically elevated levels of immune molecules called major histocompatibility complex 1 (MHC1) on their brain surface.

In the affected newborn mice, these high levels of MCH1 disrupted the development of neural cells in the brain. Specifically, the increase in MCH1 interfered with the neurons’ ability to form the synapses that allow neurons to pass electrical or chemical signals to other cells; consequently these offspring had less than half as many synapses than the control offspring. When MCH1 were returned to normal levels in the neurons of maternal immune-activated offspring, the synapses density returned to normal.

However, MCH1 doesn’t work alone. In a series of additional experiments, the researchers identified the new biological signaling pathway that regulates synapses development caused by maternal immune activation. This signaling pathway requires calcineurin, myocyte enhancer factor-2 and MCH1 to limit synapses density.

A better understanding of the underlying biological mechanisms will hopefully lead to the development of improved prenatal health screening, diagnostic tests and eventually therapies for neurodevelopmental disorders.

Of course, not every child of a bacterially or virally infected mother develops a neurodevelopmental disorder like autism. The effect of maternal immune activation depends on a complex interaction involving the strength of the infection and genetic predisposition.

This is a repost of my KQED Science blog.

New Portable Device Quickly Measures Radiation Exposure

Scientists are developing a portable device that can measure a person's radiation exposure in minutes using radiation-induced changes in the concentrations of certain blood proteins. This image shows a magneto-nanosensor chip reader station, chip cartridge, and chip. (Credit: S. Wang)
Scientists are developing a portable device that can measure a person’s radiation exposure in minutes. This image shows a magneto-nanosensor chip reader station, chip cartridge, and chip. (Credit: S. Wang)

Picture the scene of the Fukushima nuclear accident. The Daiichi nuclear reactors were hit by an earthquake of magnitude 9.0 and flooded by the resulting tsunami, which caused a nuclear meltdown and release of radioactive materials. Over 100,000 people were evacuated from their homes due to the threat of radiation contamination.

In a large-scale radiological incident like this, emergency medical personnel need a rapid way to assess radiation exposure so they can identify the people who need immediate care. This radiation-dosimetry technology needs to be sensitive, accurate, fast and easy to use in a non-clinical setting.

Local scientists have developed a small, portable device that can quickly test the level of radiation exposure victims have suffered in such emergencies. This technology was developed by scientists from Berkeley Lab, Stanford University and several other institutions, as reported in a journal article recently published in Scientific Reports. The lead researchers were Dr. Shan Wang from Stanford University and Dr. Andrew Wyrobek from Berkeley Lab.

This new dosimetry device is a novel type of immunoassay. Immunoassays are chemical tests used to detect or measure the quantity of a specific substance in a body fluid sample using a reaction of the immune system. For example, a common immunoassay test for pregnancy measures the concentration of the human chorionic gonadotropin hormone in a woman’s blood or urine sample.

In order to measure a person’s radiation dose, the new device measures a blood sample for the concentration of particular proteins that change after radiation exposure. Scientists, including those in Wyrobek’s group, have previously identified these target proteins as excellent biological markers for radiation dosimetry. Basically, blood exposed to radiation has a special biochemical signature.

But scientists needed more than just target proteins. They also needed an accurate, sensitive way to quickly measure the proteins’ concentrations in a few drops of blood. So at the heart of the new device is a biochip developed by Wang’s group.

The biochip system relies on a sandwich structure where a target protein is trapped between a capture antibody and a detection antibody. The capture antibodies are immobilized on the surface of the biochip sensor. When a drop of blood is placed on the biochip, those antibodies capture the target proteins and the other proteins are washed away. Detection antibodies labeled with magnetic nanoparticles are then added, forming a sandwich structure that traps the target proteins. When an external oscillating magnetic field is then applied, the magnetic nanoparticles generate an electrical signal that is read out. This signal measures the number of magnetic nanoparticles bound to the surface, and this indicates the number of target proteins that have been trapped.

The researchers tested the biochip system using blood from mice that had been exposed to varying levels of radiation. Their novel immunoassay results were validated by comparing them to conventional ELISA immunoassay measurements. Overall the scientists demonstrated that the new biochip dosimetry system is fast, accurate, sensitive and robust. In addition, the whole system is the size of a shoebox so it is very portable.

“You add a drop of blood, wait a few minutes, and get results,” explained Wyrobek in a press release. “The chip could lead to a much-needed way to quickly triage people after possible radiation exposure.” Although the technology is still under development, hopefully it will be available before the next radiological accident or terrorist attack occurs.

For more information about this biochip system, check out my KQED Science blog.

Earworms: Those Intrusive Songs Stuck in Your Head

manic looking man listening to music on headphones
Photograph courtesy of John Hayes Photography via a Creative Commons license.

If you could hear inside my sister’s head, it would often sound like “Deck the halls with boughs of holly, Fa la la la la, la la la la.” For years, she has had this “earworm” – a song that plays in her head without control. Her mind acts like a broken record player that repeatedly plays the same song again and again, especially during quiet times when she is alone.

Having a song stuck in your head is a common experience. Research has shown that 92% of people experience earworms at least once a week. So it isn’t surprising that many myths exist about them. One common belief is that annoying music is more likely to become stuck.  Another is that certain music characteristics, such as simplicity and repetitiveness, cause songs to become intrusive. It is also thought that having earworms is more likely for certain types of people, including musicians and women. Finally, some people believe that interrupting a song creates a sense of incompleteness that leads the song to remain in the consciousness, making it more likely to become an earworm.

Researchers from the psychology department at Western Washington University have investigated these common beliefs about earworms, as reported in a journal article recently published in Applied Cognitive Psychology. They conducted five studies on earworms: an online survey of 299 participants, an experimental diary study of 16 participants, and three lab experiments with 89, 123 or 139 participants.

In the online survey, participants answered questions about their most recent earworm, general music experience and basic demographics. The other research studies used methods to induce earworms. During the lab experiments, participants evaluated three songs, completed a puzzle (maze, Sudoku or anagram), and then reported the extent to which they heard the three songs playing in their heads while completing the puzzle. They completed either an easy or difficult puzzle.

Although annoying songs like advertising jingles can become stuck in someone’s head, this appears to be relatively rare. Researchers found that people generally know and like the songs that become intrusive.

They also found that the intrusive songs are virtually unique to each individual, which suggests that lists of the most potent earworms are misleading. Earworms are mainly formed from recent and repeated exposure to a song, so they’re influenced by listening tastes. This is supported by a previous study that identified music exposure as the primary trigger for earworms, followed by memory triggers.

Researchers found no gender difference in how earworms were experienced. However, musicians did report having earworms more frequently than non-musicians, as did people who listen to music almost constantly.

The researchers also interrupted some of the songs that they played, expecting the interrupted songs to trigger earworms more frequently than the songs played to completion. However, no difference was observed due to song interruption.

Finally, they analyzed how participants responded to completing the different puzzle tasks. Researchers found that the best way to stop an earworm is to perform a verbal task: solve an anagram, have an engaging conversation or read an interesting book. But you don’t want the task to be too easy or too challenging, or your mind will wander and the earworm may return. I guess this means that I should give my sister some engrossing novels and a book of anagrams for her birthday?

For more information about earworms, check out my KQED Science blog.

Spotlight on Red Meat

photo of raw steaks
Photograph courtesy of IwateBuddy via Creative Commons licensing

Overall meat consumption continues to rise in the U.S., and 58% of the meat consumed is red meat. People in the U.S. eat 5 ounces of meat per day on average.

Eating a lot of red meat is known to contribute to heart disease, presumably due to the large amount of saturated fats and cholesterol in the meat. Or that is what we used to think. New research published in Nature Medicine indicates that the real culprit is a chemical in the red meat called L-carnitine. In a series of experiments on humans and mice, researchers found that L-carnitine is broken down by gut bacteria to produce trimethylamine-N-oxide (TMAO), which previous research has linked to heart and artery damage. TMAO alters how cholesterol is metabolized so less is eliminated from the body, allowing more cholesterol to deposit and harden into the artery walls.

But the researchers also found that frequent meat eaters produced significantly more TMAO than vegetarians after consuming the same amount of L-carnitine. For instance, L-carnitine supplements (250 mg) were given to 74 healthy volunteers, including 23 who were long-term vegetarians or vegans. The lab tests showed that consuming L-carnitine increased the level of TMAO in the blood, but meat eaters made far more TMAO than vegetarians or vegans.

Fecal studies also showed that meat eaters and vegetarians had different types of bacteria in their guts, and the meat eaters had more of the bacteria involved in breaking down L-carnitine into TMAO.

“The bacteria living in our digestive tracts are dictated by our long-term dietary patterns,” explained the lead researcher Dr. Stanley Hazen in a press release. “A diet high in carnitine actually shifts our gut microbe composition to those that like carnitine, making meat eaters even more susceptible to forming TMAO and its artery-clogging effects.”

The main food sources for carnitine are red meat and full-fat dairy products. It is also found in fish, poultry, tempeh, wheat, asparagus, avocados and peanut butter. L-carnitine is also commonly available as a dietary supplement, which is advertised as a weight loss and body building tool despite a lack of supporting scientific evidence. Plus L-carnitine is added to many energy drinks.

So eating all this L-carnitine is bad, right? Unfortunately it isn’t that simple.

Carnitine plays a vital and complex role in cardiac metabolism. Some people have diseases that cause a carnitine deficiency, so they need to take carnitine supplements. Studies have also shown that carnitine may help treat some heart conditions, such as angina, arrhythmias, heart attacks and heart failure. For instance, a meta-analysis review study in the Mayo Clinic Proceedings recently showed that taking L-carnitine supplements reduces your risk of ventricular arrhythmias by 65% and risk of angina by 40%, although no reduction in risk was seen for heart attacks and heart failure.

In general, scientific studies have shown both positive and negative effects on cardiac health from taking carnitine supplements. These discrepant findings may be due to differences in how the carnitine is administered and the dose. For instance, carnitine given by an intravenous or intramuscular injection would bypass the gut bacteria, so it may not form TMAO. Larger carnitine studies are needed, which also take into account the volunteers’ long-term diet and the bacteria ecosystem in their guts.

For more information about L-carnitine studies, check out my KQED Science blog.

Air Pollution Lurks Inside Your Home

photo of stir-frying
Photograph by kfisto via Creative Commons licensing.

How would you like a job that involves grocery shopping at Trader Joes with the company credit card and cooking dishes like stir-fry? This describes Tosh Hotchi’s job, but he isn’t a chef. He is part of a research team that studies how to build healthy efficient homes, including how to improve the quality of air inside a home through better ventilation. Hotchi is helping to study a major source of indoor pollutants – cooking.

When people think of air pollution, they usually picture a factory spewing a plume of toxic chemicals. But indoor air pollution causes significant health effects such as respiratory illness, asthma attacks, cancer and premature death. Californians spend over 45 billion dollars each year on these health impacts, according to a study by the California Air Resources Board.

Scientists at the Lawrence Berkeley National Laboratory (Berkeley Lab) have investigated which indoor air pollutants cause the greatest health consequences. In a paper published in Environmental Health Perspectives, they reported that fine particles with a diameter of 2.5 mm or less, formaldehyde and acrolein are the worst indoor contaminants for nonsmoking households.

Fine particulates are found indoors mainly due to cooking, burning candles or incense, and outdoor sources that leak inside. Formaldehyde is mainly emitted by materials used in home construction and furniture, such as particle board, paneling and foam insulation. Acrolein in the home is primarily from cooking, especially oils. All three of these contaminates also come from tobacco smoke.

“Think about what your putting in your home,” says Melissa Lunden, a Berkeley Lab staff engineer. “Most of us have to cook, but do you need the candles, incense and air fresheners? Freshening your air requires taking stuff out, not putting more stuff in.”

Berkeley Lab scientists are now looking for ways to improve indoor air quality, by developing better standards for residential buildings and new tests to measure these hazardous pollutants. Since cooking is a major source of indoor air pollutants, they have also evaluated the effectiveness of cooking exhaust hoods. Their study results showed that indoor air quality can be significantly improved by simply cooking on the back burners of your stove, using higher fan settings, and turning the fan on before you start cooking. Further research on cooking-induced pollutants is underway using a new demonstration kitchen to study real-life cooking conditions. During these studies, Tosh Hotchi’s stir-fry and cookies are just a happy bonus for his coworkers like Melissa Lunden.

For more information about indoor air pollution, check out my KQED Quest blog.

Nerve Stimulation May Prevent Migraines

Photograph of the Cefaly anti-migraine device, courtesy of STX-Medssprl via Creative Commons licensing
Photograph of Cefaly anti-migraine device, courtesy of STX-Med via Creative Commons license

While shopping for groceries at Trader Joes, suddenly your peripheral vision disappears. This could be frightening, but you know what is coming — a one-sided pulsating pain, sensitivity to light and noise, nausea, vomiting and seeing flashing lights. You quickly drive home and cancel your plans, because you have a migraine coming. You need to lie still in a dark quiet room for the next 24 hours.

Migraines affect about 30 million Americans. This means that one in four households in the US have at least one member impaired by migraines. Women are three times more likely to be migraine sufferers than men.

Unfortunately, there is currently no cure for migraines. A migraine diary can help identify the headache triggers to avoid. Medications can also help reduce the number of attacks or ease the symptoms, but these medications are often ineffective or cause unpleasant side effects.

Instead migraine sufferers might find relief from a new non-medicinal alternative, a device called a supraorbital transcutaneous stimulator (STS) that stimulates the nerves around the eyes and forehead. A study recently published in Neurology tested the safety and effectiveness of this STS device designed to prevent migraines.

Conducted by researchers in five specialized headache clinics in Belgium, this study was a randomized controlled trial that compared the STS device with an identical-looking sham device. Study participants were aged 18 to 65 who routinely experienced a minimum of two migraine attacks per month. None of the 67 participants had taken anti-migraine medications in the three months leading up to the study.

Both the STS and sham devices used a self-adhesive electrode placed on the forehead that buzzed identically during treatment. Only the STS devices delivered electrical impulses. The participants wore one of the devices for 20 minutes per day for 90 days.

The participants’ migraine diaries indicated that the number of migraine attacks dropped by at least half for 38% of the participants using the STS device, compared with 12% for those using the sham device. Although the severity of the migraines was not reduced, people using the STS device had fewer days with headache, fewer total migraine attacks, and used fewer pain relief medications each month. Most importantly, there were no adverse effects seen in either group.

The study concluded that treatment with a STS device is “effective and safe as a preventive therapy for migraine.” However, only 67 migraine sufferers have been studied and the use of this device was only examined for three months. Larger studies with longer-term treatment are needed to confirm that this STS device is safe and effective.

For more information about migraines and the STS device, check out my KQED Quest blog.