New blood test could detect early-stage pancreatic cancer

Posted February 17, 2017 by Jennifer Huber
Categories: Health

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Pancreatic cancer is one of the leading causes of cancer death, because it is seldom detected before the disease has spread to other organs. Only 8 percent of people with pancreatic cancer survive five or more years after diagnosis.

Now, researchers hope to change this bleak scenario with an improved blood test that can detect early-stage pancreatic cancer. A multi-institutional team led by Tony Hu, PhD, an associate professor at Arizona State University, recently reported on their results in Nature Biomedical Engineering.

The researchers first identified the presence of a protein in the blood, called ephrin type-A receptor (EphA2), which is overexpressed by pancreatic tumors. Next, they developed a biosensor using gold nanoparticles that selectively bind to EphA2, changing their light emitting properties. This allowed the team to quantify the amount of EphA2 in a blood sample to see if it is overexpressed.

They validated their biosensor in a pilot study involving 48 healthy people, 59 patients with stage I-III pancreatic cancer and 48 patients with chronic pancreas inflammation. The later condition is often confused with pancreatic cancer using existing diagnostic tests like ultrasound.

The biosensor was able to accurately identify the patients with pancreatic cancer — even those with early stage disease — as well as the patients with chronic pancreas inflammation. If these results are validated with a larger clinical trial, the blood test could screen for pancreatic cancer and could be adapted for other diseases.

“We are now working on lung cancer and lymphoma and have very positive results,” Hu said in a recent news story. “In addition to cancer, we are conducting a project on tuberculosis diagnosis. Theoretically this test could be applied to any type of disease.”

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

Unable to smell? One Stanford researcher is working to improve therapies

Posted February 13, 2017 by Jennifer Huber
Categories: Health

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I don’t often think about my sense of smell, unless I’m given a fragrant flower or walk past someone smoking. But the ability to smell is both critical and underappreciated, according to Zara Patel, MD, a Stanford assistant professor of otolaryngology, head and neck surgery.

A smell begins when a molecule — say, from a flower — stimulates the olfactory nerve cells found high up in the nose. These nerve cells then send information to the brain, where the specific smell is identified. Anything that interferes with these processes, such as nasal congestion or damage to the nerve cells, can lead to a loss of smell.

I recently spoke with Patel about the loss of the sense of smell, a condition known as anosmia.

How does losing the sense of smell impact patients?

“If asked which sense they’d give up first, most people would likely choose their sense of smell. It’s only after the loss of olfaction that its significant impact on our lives is appreciated. Our sense of smell plays a key role in a vast array of basic human interactions, such as what attracts us to sexual partners, what keeps us in committed relationships and how maternal bonding occurs with newborns. It’s also one of our most basic protective mechanisms that allows us to wake up in the midst of a fire and prevents us from eating spoiled food. And importantly — keeping in mind that our ability to taste is highly dependent on our ability to smell — the inability to enjoy food and related social activities often causes social isolation, depression and malnutrition.”

What causes olfactory loss?

“There are over 100 reasons why people can lose their sense of smell. However, the majority of people lose it from sinonasal inflammatory disease, post-viral infections, traumas or tumors. Unfortunately, olfactory loss is often of “idiopathic” origin, meaning we just don’t know what caused it. That is why research in this area is so important.

It’s also important to be treated as early as possible. It is always frustrating to see someone who lost their sense of smell over a year ago, but they weren’t referred to me at the time or were told that nothing could be done. Those are missed opportunities that will negatively impact those patients for the rest of their lives.”

How do you treat patients who can no longer smell?

“The treatment really depends on the reason for loss, and may include surgery or medications. For those who lose the ability to smell after trauma, post-viral infection or when we don’t know why it happened, olfactory training can be used, which is a very simple protocol that patients can do at home. The patients smell several essentials oils in a structured way twice a day, every day, over a long period of time. The oils — rose, eucalyptus, clove and lemon —stimulate different types of olfactory receptor cells in the nose. Although it does not help everyone, it has been shown to be effective in 30 to 50 percent of patients, across multiple origins of loss.

We don’t have an exact understanding of how and why it works. However, a study using functional MRI observed a change in how the brain responds to odors before and after olfactory training. Before the training, there was a chaotic array of random areas lighting up in the brain. After the training, the images showed a renewed pathway to the olfaction center in the brain. We also know that the olfactory nerve has an inherent ability to regenerate. We’re trying to take advantage of this fact and ‘switch on’ those regenerative cells.

I have many patients who have benefited from olfactory training, including some who need their sense of smell for their livelihood — such as chefs or wilderness guides. Being able to get that sense back has allowed them to continue doing what they’re passionate about and has increased their quality of life.”

What are you working on now?

“Although olfactory training has allowed us to help more patients, 30 to 50 percent improvement is still quite low and certainly not the final answer. That’s why the research I’m currently doing has me excited about the potential of using both stem cells and neurostimulation to advance this field. I hope to soon be able to offer alternative interventions to these patients.”

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

Stanford researchers develop simulations to improve heart surgeries

Posted February 9, 2017 by Jennifer Huber
Categories: Health

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MRI or CT scans provide physicians with a detailed picture of their patients’ internal anatomy. Heart surgeons often use these images to plan surgeries.

Unfortunately, these anatomical images don’t show how the blood is flowing through the vessels — which is critical, according to Alison Marsden, PhD, a Stanford associate professor of pediatrics and of bioengineering. In the video above, she explains that many surgeons currently use a pencil and paper to sketch out their surgical plan based on the patient’s images. She hopes to change this.

Marsden and her colleagues at Stanford’s Cardiovascular Biomechanics Computational Lab are developing a new technique — using imaging data and specialized simulation software — to predict what is likely to happen during heart surgery.

“What we’re trying to do is bring in that missing piece of what are these detailed blood flow patterns and what might happen if we go in and make an intervention, for example, opening up a blocked blood vessel or putting in a bypass graft,” Marsden said in a recent Stanford Engineering news story.

Their open source software, called SimVascular, loads the imaging data, constructs a 3D anatomical model of the heart and then simulates the patient’s blood flow. It has already been used to help design the surgical plan for several babies born with a severe form of congenital heart disease, Marsden said. However, more research is needed to determine whether the technique improves patient outcomes before it can be widely used in the clinic.

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

What you need to know about e-cigarettes

Posted February 7, 2017 by Jennifer Huber
Categories: Health

Tags: , , ,

 

Photo by 1503849

Photo by 1503849

E-cigarettes are extremely popular with millions of middle and high school students across the United States. Kids love the flavors — like strawberry, bubble gum, chocolate cake and cotton candy — and blowing vapor into rings. And, they are inundated with ads that tout e-cigarettes as cool, harmless alternatives to cigarettes.

But, not surprisingly, e-cigarettes aren’t really safe. A recent University of California news story outlines ten important facts about e-cigarettes, including how they can harm your health.

One of the biggest health concerns is that e-cigarettes contain nicotine, which is addictive and can lead to the use of traditional cigarettes. “A lot of kids who take up [nicotine-free] vaping are at low risk for smoking, but once they start using e-cigarettes, they are three to four times more likely to start using cigarettes,” said Stanton Glantz, PhD, a tobacco researcher at the University of California, San Francisco, in the article.

In addition, e-cigarettes can contain other harmful ingredients, including:

  • Ultrafine particles that can trigger inflammatory problems and lead to heart and lung disease
  • Toxic flavorings that are linked to serious lung disease
  • Volatile organic compounds
  • Heavy metals, such as nickel, tin and lead

Stanford’s Bonnie Halpern-Felsher, PhD, a developmental psychologist who has studied tobacco use, also commented in the piece:

“Youth are definitely using e-cigarettes because they think they are cool… Adolescents and young adults don’t know a lot about e-cigarettes. They think it’s just water or water vapor. They don’t understand it’s an aerosol. They don’t understand that e-cigarettes can have nicotine. They don’t understand that flavorants themselves can be harmful.”

Furthermore, when e-cigarette users exhale the mainstream vapor containing these toxins, they can cause secondhand health effects.

The article discusses other hazards as well, including the possibility of battery explosion, and the products’ mixed record on helping smokers quit. It concluded with a call for more research to better understand the long-term health effects of e-cigarettes.

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

Stanford researchers map brain circuitry affected by Parkinson’s disease

Posted February 2, 2017 by Jennifer Huber
Categories: Health

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In the brain, neurons never work alone. Instead, critical functions of the nervous system are orchestrated by interconnected networks of neurons distributed across the brain — such as the circuit responsible for motor control.

Researchers are trying to map out these neural circuits to understand how disease or injury disrupts healthy brain cell communication. For instance, neuroscientists are investigating how Parkinson’s disease causes malfunctions in the neural pathways that control motion.

Now, Stanford researchers have developed a new brain mapping technique that reveals the circuitry associated with Parkinson’s tremors, a hallmark of the disease. The multi-disciplinary team turned on specific types of neurons and observed how this affected the entire brain, which allowed them to map out the associated neural circuit.

Specifically, they performed rat studies using optogenetics to modify and turn on specific types of neurons in response to light and functional MRI to measure the resulting brain activity based on changes in blood flow. These data were then computationally modeled to map out the neural circuit and determine its function.

The research was led by Jin Hyang Lee, PhD, a Stanford electrical engineer who is an assistant professor of neurology and neurological sciences, of neurosurgery and of bioengineering. A recent Stanford News release explains the results:

“Testing her approach on rats, Lee probed two different types of neurons known to be involved in Parkinson’s disease — although it wasn’t known exactly how. Her team found that one type of neuron activated a pathway that called for greater motion while the other activated a signal for less motion. Lee’s team then designed a computational approach to draw circuit diagrams that underlie these neuron-specific brain circuit functions.”

“This is the first time anyone has shown how different neuron types form distinct whole brain circuits with opposite outcomes,” Lee said in the release.

Lee hopes their research will help improve treatments for Parkinson’s disease by providing a more precise understanding of how neurons work to control motion. In the long run, she also thinks their new brain mapping technique can be used to help design better therapies for other brain diseases.

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

Too few woman scientists are invited to review academic journal manuscripts

Posted January 31, 2017 by Jennifer Huber
Categories: Science Communication

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As a researcher at Lawrence Berkeley National Laboratory, I reviewed manuscripts for several academic science journals and acted as an editor for an engineering journal.

This makes me an exception, according to a commentary recently published in Nature that reveals a gender bias in the review of scholarly publications. Journals invite too few women to referee, write commentary authors Jory Lerback, a graduate student at the University of Utah, and Brooks Hanson, PhD, director of publications at the American Geophysical Union (AGU).

The peer review process plays a critical role in the validation of research by allowing experts to scrutinize the work of their peers before research results are published. Participating in this review process is also critical to a scientist’s career. The commentary explains:

“Participation as a reviewer for papers and grants has many benefits, particularly for early-career scientists. It is a chance to develop a relationship and make a positive impression with an editor, review-panel member or programme manager, who are typically senior scientists and are in turn likely to be involved in evaluating the reviewer’s future papers and grants.”

Unfortunately, Lerback and Hanson found that women of all ages have fewer opportunities to act as a reviewer for AGU journals.

Using membership and editorial databases, they identified the age and gender of authors, reviewers and editors for AGU manuscripts from 2012 to 2015 — creating a dataset that included more than 24,000 authors, nearly 15,000 reviewers, nearly 100,00 reviewer suggestions by authors and 119,000 reviewer requests by editors.

Analysis of this dataset showed that only 20 percent of reviewers were women, proportionally less than expected as 28 percent of AGU members were female and 27 percent of first authors were female. This difference was observed across all ages, so it was not due to editors seeking more senior reviewers who are predominantly male.

The problem, they found, was due to a gender bias in reviewer selection. At AGU, authors suggest reviewers at submission and editors prepare a final list. However, both authors and editors nominated fewer women to review. Female first authors suggested female reviewers 21 percent of the time, whereas male first authors suggested women just 15 percent of the time. Similarly, female editors recommended female reviewers 22 percent of the time compared to 17 percent for male editors.

Is this just a problem for AGU journals? The authors don’t think so. As the largest Earth and space science society and publisher, they argue that AGU is a good proxy for STEM demographics in the United States. In addition, they suggest that similar problems exist for funding agencies.

The researchers recommend that publishers hire more female editors and train their staff to combat this gender bias.

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

Reimagining Nutrition Education: Doctor-chefs teach Stanford medical students how to cook

Posted January 30, 2017 by Jennifer Huber
Categories: Health, Nutrition, Science Education

Tags: ,
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Photograph courtesy of Michelle Hausman

Stanford medical students still learn traditional topics like anatomy, genetics and neuroscience. But now, they can also learn how to cook, thanks to a new hands-on course developed in part by Stanford’s Michelle Hauser, MD.

A former Le Cordon Bleu chef, Hauser is currently an internal medicine-primary care attending for Stanford residents and a postdoctoral research fellow at the Stanford Prevention Research Center. She teamed up with Stanford pediatrics instructor Maya Adam, MD; physician Tracy Rydel, MD; nutrition researcher Christopher Gardner, PhD; physician-chef Julia Nordgren, MD; and Stanford chef, David Iott, to launch the new class, which is featured in a video.

Hauser said the course aims to teach future clinicians how to cook healthy food, so they can more effectively counsel their patients on nutrition and diet. Intrigued, I spoke with her recently.

Why did you introduce this course?

“Diet is the most significant risk factor for disability and premature death in the US. However, less than one-third of medical school and residency programs offer a dedicated nutrition course to their students. When courses are available, many schools use outdated, overly long and complicated online modules rather than in-person nutrition instruction. They often just focus on nutrients, whereas patients think of nutrition in terms of food. And most schools don’t teach how to effectively counsel patients to change their behavior around eating — people know it is healthy to eat more vegetables, but how do they accomplish this? We need to better prepare physicians to treat the underlying causes of disease and to prevent diet and lifestyle-related diseases from occurring in the first place.”

How can your course help?

“Teaching kitchens are the perfect, hands-on medium to help doctors learn about food. By learning to prepare delicious, healthy food for ourselves, we become healthier — and studies show that physicians with healthy habits are more likely to counsel patients on those habits. Additionally, it’s more fun and memorable to learn about food and nutrition while cooking and sharing meals together than it is to sit in a lecture hall.

As a platform to teach about nutrition, our new teaching kitchen elective focuses on how to prepare healthy meals based on plants and whole foods, a diet that is ideal for the majority of the population. We also teach a concept called the “protein flip” — instead of having the center of your plate be a large piece of meat, you use meat as a garnish for a plate full of plant-based foods, such as vegetables, fruits, whole grains, legumes, nuts and seeds. Think veggie chicken stir-fry with brown rice or a main course salad with a small portion of grilled salmon.

Our sessions use a flipped classroom format. Before class, students view engaging preparatory videos online (and many of these are available through Stanford’s Food and Health series). At Stanford’s teaching kitchen, they watch the chefs’ cooking demonstrations and then lace up their aprons and start chopping and cooking. In addition, Tracy Rydel, Maya Adam, Christopher Gardner and faculty from other medical programs are cooking alongside the medical students to represent the lay cook’s perspective, as well as spread the idea of using teaching kitchens to others in the Bay Area and beyond. At the end of each session, we all share and eat together.”

How do you make healthy food appealing?

“Healthy food has gotten a bad rap for far too long. We need to make sure that healthy food is delicious if we expect people — including ourselves — to eat it so that it can nourish our bodies and prevent nutrition-related chronic diseases. Food is a huge part of all of our cultural identities and is intricately linked with many of our fondest memories. I often see medical professionals in training and in practice tell patients to stop eating a whole variety of things — many with personal and cultural significance — without helping them figure out what and how to eat differently. And these conversations often make it sound like the patient needs a ‘special’ diet inappropriate for the whole family. Instead, we need to celebrate the togetherness of sharing healthy food.

 For the final project, the students will make favorite healthy foods that mean something to them. For instance, I would make hummus, tabouli and falafel wraps (falafels rolled up in warm whole-wheat pita bread with chopped tomatoes, scallions, cucumbers and spring mix drizzled with lemon-tahini sauce). As a vegetarian with a dairy allergy, my Irish-immigrant family’s traditional Christmas dinner normally left me with a lonely potato and a few token veggies. However, a few years back I cooked this Middle Eastern meal for my family and it was a hit. And this year, my mom requested that we make the meal as the centerpiece of our Christmas spread!”

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.


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