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Precision health, Research, Science, Transplants

Study: Treatment plans for kidney failure should consider cause and circumstances of disease

Study: Treatment plans for kidney failure should consider cause and circumstances of disease

3349943474_0e1bc4236b_zOne size seldom fits all, so it’s not surprising that one treatment regimen may not suit all patients with the same condition. Now, a new study of end-stage kidney failure shows the importance of taking factors like cause and circumstances of a patient’s disease into account when designing a treatment plan.

The study (subscription required) began when Stanford nephrology fellow Michelle O’Shaughnessy, MD, noted that patients with end-stage kidney-failure usually received the same generic treatment plan (dialysis or a kidney transplant), even though there are different causes of the disease and a patient’s condition can progress to kidney failure via many different routes.

As described in our press release, kidney disease is often caused by diabetes or hypertension, but it can also be caused by glomerular disease, a condition with many distinct subtypes. And:

[E]ach of the many glomerular disease subtypes is unique. In certain subtypes, the immune system attacks the kidneys; in others, it damages the blood vessels.

As a result, the various subtypes are treated using different methods before the kidneys begin to fail. The treatments may include steroids or stronger immunosuppressant medications. The resulting side effects can range from severe infections to diabetes to cancer.

For their work, O’Shaughnessy and her colleagues examined data collected from 84,301 patients with end-stage kidney disease caused by one of six major subtypes of glomerular disease. The results showed that the type of glomerular disease significantly affected how long the patient lived after they developed kidney failure; mortality ranged from 4 percent per year for one type of patient to 16 percent per year for another.

“It’s important to know why one kidney patient does well and another does poorly,” concluded O’Shaughnessy. “If physicians take into consideration what caused the kidneys to fail in the first place and what types of treatments patients received prior to kidney failure, it could possibly improve the patients’ quality of life or increase their life span.”

Previously: Keeping kidney failure patients out of the hospitalStudy shows higher Medicaid coverage leads to lower kidney failure ratesStudy shows higher rates of untreated kidney failure among older adults and Geography may determine kidney failure treatment level
Photo by scribbletaylor

NIH, Pregnancy, Research, Technology, Women's Health

Scientists create a placenta-on-a-chip to safely study process and pitfalls of pregnancy

Scientists create a placenta-on-a-chip to safely study process and pitfalls of pregnancy

2798127284_487b56b9cf_zThese days it seems that just about anything can be recreated on a microchip. But still, I did a double-take when I read about the new way that scientists are using technology to study pregnancy: They’ve created a “placenta-on-a-chip.”

A functioning placenta is critical for a healthy pregnancy because it regulates the flow of nutrients, oxygen and waste products between the mother and fetus. It also controls the fetus’ exposure to bacteria, viruses and other harmful substances. Researchers would like to learn more about how the placenta acts as a “crossing guard” and how it can regulate the body’s traffic so well. Yet, studying the placenta is hard to do because it’s highly variable, and tinkering with the placenta is risky for the fetus.

To overcome these challenges, an interdisciplinary team led by a University of Pennsylvania researcher created a two-chambered microchip that mimics the structure and function of the human placenta. The study was published online in the Journal of Maternal-Fetal and Neonatal Medicine and is reported on in this National Institutes of Health press release:

The device consists of a semi-permeable membrane between two tiny chambers, one filled with maternal cells derived from a delivered placenta and the other filled with fetal cells derived from an umbilical cord.

After designing the structure of the model, the researchers tested its function by evaluating the transfer of glucose (a substance made by the body when converting carbohydrates to energy) from the maternal compartment to the fetal compartment. The successful transfer of glucose in the device mirrored what occurs in the body.

As Roberto Romero, MD, chief of the perinatology research branch at the NIH’s National Institute of Child Health and Human Development, explains in the press release, this new technology could help researchers explore how the placenta works, and what happens when it fails, in ways that couldn’t be safely done before. This, the researchers say, could lead to more successful pregnancies.

Previously: NIH puts focus on the placenta, the “fascinating” and “least understood” organPlacenta: the video game, The placenta sacrifices itself to keep baby healthy in case of starvation, research showsThe placenta sacrifices itself to keep baby healthy in case of starvation, research shows and Program focuses on the treatment of placental disorders
Photo by Jack Fussell

Genetics, HIV/AIDS, Infectious Disease, Research, Stanford News

Study shows toothed whales have persisted millions of years without two common antiviral proteins

Study shows toothed whales have persisted millions of years without two common antiviral proteins

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Our ability to fend off the flu, HIV and other viruses is enhanced when proteins are produced by two “immune genes,” called MX1 and MX2. Other mammals also have these genes, but little is known about the role they play in the immune responses of these animals.

Now a study comparing the genomes and Mx genes of 60 mammal species has revealed a surprising finding: Every species in the study has functioning Mx1 and Mx2 genes except for dolphins, whales and orcas — species from a lineage of toothed whales that’s persisted for roughly 33 million years.

Gill Bejerano, PhD, a geneticist and developmental biologist, graduate student Benjamin Braun and their team wanted to know more about the status and function of Mx genes in non-human mammals. To do this, they examined and compared the part of the genome that contains the Mx genes in 60 different species including humans, cows, whales, dolphins and orcas.

I think this will open up very exciting research avenues, either to better protect the compromised whales, or to study their different viral defenses, and someday add them to our own arsenal.

The study, published this week in the Proceedings of National Sciences, showed that the Mx1 and Mx2 genes in the toothed whales (bottlenose dolphin, orca, Yangtze river dolphin and sperm whale) they tested were non-functional, and couldn’t produce the proteins that help fight viral infections. Bejerano explained the significance of this finding in our press release:

Given how important the Mx genes seem to be in fighting off disease in humans and other mammals, it’s striking to see a species lose them both and go about its business for millions of years.

To find out when in evolutionary history these genes became inactive the researchers compared the genomes of toothed whales to that of their closest ancestors, the baleen whales and hoofed mammals (ungulates). They found that the Mx genes function in baleen whales and hoofed mammals, but not in toothed whales. This means that some — perhaps all — toothed whales likely lost use of their Mx genes when this lineage split off from these ancestors about 33 million years ago (see Fig. 1).

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Behavioral Science, Events, Mental Health, Research, Videos

Stanford bioengineer uses his experience in Iraq to improve research of TBI and PTSD

Stanford bioengineer uses his experience in Iraq to improve research of TBI and PTSD

777423808In 2012, President Obama issued an Executive Order calling for better prevention, diagnosis and treatment of traumatic brain injury (TBI), post-traumatic stress disorder (PTSD) and other mental health conditions. Third-year doctoral student Russell Toll is one of many who is doing research in these areas, and he brings a unique perspective to his work: He’s both a bioengineer and an Army combat veteran.

In 2006, Toll was in charge of a combined tank and infantry platoon stationed in the Diyala River Valley, about an hour northeast from Baghdad, Iraq.

His unit deployed with 14 tanks; they came back with four. Within 15 months, 28 men in his batallion were killed and 132 were severely wounded. A third of his men earned the Purple Heart and his unit — the 1-12 CAV in the 1st Cavalry Division — earned the Valorous Unit Citation for extraordinary heroism.

Now, Toll is working with his graduate advisor, Amit Etkin, MD, PhD, an assistant professor in the Department of Psychiatry and Behavioral Sciences, to identify biomarkers associated with TBI and PTSD. Toll and Etkin will discuss their work at the West Coast preview of the film “Searching for Home: Coming Back from War” next Saturday, June 20, at Stanford’s Cubberley Auditorium.

Recently, I spoke with Toll to learn more about his experience in Iraq and his research.

How did your experience in Iraq inform your understanding of PTSD?

As a platoon leader, all of your thoughts and efforts are focused on keeping your unit safe and getting them home. Only after you get home and decompress do you realize how much [weight] you were carrying.

This is a common experience for many soldiers and people that have lived through a traumatic experience.

At what point in your military career did you become interested in bioengineering and research on TBI and PTSD?

The pivotal point was in 2009 when I visited Walter Reed [National Military Medical Center] to check in on my men. The care they received at the center was excellent, but some of the equipment and technology that was being used to diagnose and treat them seemed like it hadn’t changed since Vietnam.

When I returned to my hotel room at night, I found myself drawing up ways we could address this problem on the backs of napkins. I have a bachelors degree in systems engineering from West Point, and I decided to apply these skills as a graduate student in bioengineering.

What was it like to come to Stanford after spending 15 months in Iraq?

It was a stark transition from the Army to Stanford; I felt like I had just climbed off the tank and stepped straight into systems biology. It sounds funny, but in a way I was able to apply my military training to my graduate studies: I developed cooperative relationships with the “indigenous experts” so I could get help from my classmates. As evidenced by my friends, I’m good at surrounding myself with excellent people. Their tutoring, coaching and friendship — especially that of Shrivats Iyer — was a major reason I was able to make it this far.

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Evolution, Global Health, Medical Education, Research, Stanford News

Stanford med student/HHMI fellow investigates bacteriophage therapy as an alternative to antibiotics

Stanford med student/HHMI fellow investigates bacteriophage therapy as an alternative to antibiotics

IMG_5145 croppedSecond-year medical student Eric Trac isn’t one to shy away from a challenge. Trac’s family is from Vietnam and he didn’t speak much English as a child, but Trac and his mother overcame this hurdle by practicing English and studying together every night until the early morning hours so he could do well at school. Now, just 12 years later, Trac is a Howard Hughes Medical Institute (HHMI) fellow taking on a new kind of challenge: investigating an alternative to antibiotics.

Many people think that antibiotics are the only way to kill bacteria, but this isn’t true. “Before we used antibiotics, we used bacteriophages,” Trac said. “Just like viruses attack people, bacteriophages attack bacteria. In other words, bacteria can get sick as well.”

Bacteriophages have been used since the early 1900s in countries like France, Poland and the U.S. to treat diseases such as cholera and dysentery. But interest in bacteriophage therapy, and its use, declined in the West after antibiotics were discovered in the 1920s. Now that bacteria are becoming increasingly resistant to antibiotics, researchers in the West are taking interest in the decades of bacteriophage research that continued in Eastern Europe and the former Soviet Union long after antibiotics became popular elsewhere. Unfortunately, many of these studies don’t meet the scientific standards (e.g., double blind studies, experimental controls) that Western drug research requires.

So, for his year-long HHMI project, Trac and his mentors, bioengineer and physicist Stephen Quake, PhD, and pediatric pulmonary expert David Cornfield, MD, will test bacteriophage therapy — with the required scientific protocols — to see if it could be a viable, and safe alternative to antibiotics. His project will focus on two common bacteria, Pseudomonas aeruginosa and Staphylococcus aureus, that can cause life-threatening infections, especially in people with cystic fibrosis. “The need for alternative ways to kill these two bacteria is great,” Trac said.

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In the News, Public Health, Research, Sleep

New recommendation: Adults need at least 7 hours of sleep each night

New recommendation: Adults need at least 7 hours of sleep each night

17376155493_6588ac3dcc_zHow much sleep is enough, and is it possible to sleep too much? Until recently, there wasn’t much consensus on sleep guidelines for adults. Now, a new set of recommendations agreed upon by a team of sleep experts helps put these questions to rest: Adults need a minimum of seven hours of sleep each night, preferably more.

These new recommendations, published yesterday in the journal SLEEP (subscription required), were developed by 15 sleep experts in a consensus panel assembled by the American Academy of Sleep Medicine and the Sleep Research Society. One of the panelists was Clete Kushida, MD, PhD, medical director of the Stanford Sleep Medicine Center, and I reached out to him to learn more about their work.

The goal of the panel was to take stock of existing studies on sleep and use the information to come to a consensus on a recommended sleep amount, he told me. To do so, “the panel reviewed and evaluated 5,314 scientific articles on sleep over a 12-month period.”

After examining the literature, the panel concluded that “sleeping six or fewer hours per night is inadequate to sustain health and safety in adults, and [they] agreed that seven or more hours of sleep per night is recommended for all healthy adults.”

Perhaps the most interesting aspect of the recommendations is that they don’t place an upper limit on the amount of sleep. Nine hours is often cited as the maximum amount of time an adult should sleep, yet these new guidelines state that it’s okay for adults to sleep more if needed.

I asked Kushida why the new recommendations do away with the nine-hour sleep limit. Simply put, he said: “Sleeping more than nine hours per night on a regular basis may be appropriate for young adults, individuals recovering from sleep debt, and individuals with illnesses.”

The take-home message is that adults can be healthy on seven hours of sleep each night, but this amount of rest is not ideal. It’s better for adults to sleep more if possible, especially when they’re young, sleep deprived or ill.

Previously: Exploring the history and study of sleep with Stanford’s William DementStanford docs discuss all things sleepBBC study: Oh, what a difference an hour of sleep makes, Study shows seniors sleep better than younger adultsExploring the effect of sleep loss on health and What are the consequences of sleep deprivation?
Photo by Craig Sunter

Medical Education, Medicine and Literature

MeDesign Human Health Book: human anatomy diagrams with sleek new look

MeDesign Human Health Book: human anatomy diagrams with sleek new look


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For many people, the topic of human anatomy evokes feelings of both marvel and dismay. The workings of the body may be a wonder to behold, but their intricacies can be a pain to sort out, remember and explain.

To make human anatomy easier to learn and understand, Bruce Ian Meader, an associate professor at the Rochester Institute of Technology’s Vignelli Center for Design Studies, and his class of 13 first-year graduate students tackled the task of streamlining diagrams of human anatomy in 2014 as part of the School’s Medicine+Design initiative.

For this assignment, the class was given 10 weeks to design several short book chapters that explain systems of the human body for a general audience. To accomplish the task, the class split into small groups to research, write, and design simplified layouts of body systems, such as the brain, eyes, joints and nervous system. Once the book chapters were complete, the students worked together to assemble the chapters into a book they called the MeDesign Human Health Book.

The book is already earning praise and has sparked a second phase for the Medicine+Design initiative in 2015. You can view the entire book online for free at the school’s website.

Previously: University of Glasgow medical student makes learning anatomy a feast for the sensesImage of the Week: A playful take on the human respiratory systemImage of the Week: VeggieanatomyImage of the Week: Quilled anatomyKitchen anatomy: Brain carved from a watermelon
Via Street Anatomy
Artwork courtesy of Bruce Ian Meader and artist Cai Jai

Emergency Medicine, Nutrition, Pediatrics, Rural Health

Study finds arm circumference is accurate measure of malnutrition in children with diarrheal illnesses

Study finds arm circumference is accurate measure of malnutrition in children with diarrheal illnesses

Malnutrition is a leading cause of mortality in children under the age of five, contributing to approximately 3.5 million child deaths worldwide each year. Currently, the World Health Organization and Doctors Without Borders recommend using calculations based on the patient’s body weight or arm circumference to assess their nutritional status. But, it’s not known if they are reliable measures of malnutrition in children that suffer from diarrhea and dehydration — two symptoms that can affect body weight and are common in undernourished kids.

Now, a study (subscription required) published this month in the Journal of Nutrition shows that mid-upper arm circumference can accurately assess malnutrition in children with diarrhea and dehydration and it’s better at assessing malnutrition than weight-based measures.

In the study, Rhode Island Hospital emergency medicine physician Adam Levine, MD, and his team analyzed 721 records of children (under the age of five) who were examined at an urban hospital in Dhaka, Bangladesh for acute diarrhea. They found that measurements based on a child’s mid-upper arm circumference accurately diagnosed malnutrition, but measurements based on weight were unreliable and misdiagnosed about 12-14 percent of the cases when the patient had diarrhea and dehydration.

“Because dehydration lowers a child’s weight, using weight-based assessments in children presenting with diarrhea may be misleading,” Levine said in a press release. “When children are rehydrated and returned to a stable, pre-illness weight, they may still suffer from severe acute malnutrition.”

Since poor nutrition is a common problem in areas where medical resources are limited, the best tools to diagnose malnutrition are effective and inexpensive. Tape measures are cheaper and are often easier to come by than scales, so the results of this study are especially encouraging for people who want the best and most affordable way to measure malnutrition in children. “Based on our results, clinicians and community health workers can confidently use the mid-upper arm measurement to guide nutritional supplementation for children with diarrhea,” said Levine.

Previously: Stanford physician Sanjay Basu on using data to prevent chronic disease in the developing worldMalnourished children have young guts and Seeking solutions to childhood anemia in China
Photo by European Commission DG ECHO

Behavioral Science, Health and Fitness, Obesity, Public Health, Sleep

How insufficient sleep can lead to weight gain

How insufficient sleep can lead to weight gain

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I don’t think I’ve ever met a person who hates sleep and can’t wait to get less of it. Yet, even though most people want more sleep and know it’s important for their health, few people get as much shut-eye as they need. If you’re one of the many who needs a bit more motivation to get to bed earlier, a recent BeWell@Stanford article on how sleep can affect your weight may do the trick.

In the Q&A, sleep expert Emmanuel Mignot, MD, PhD, director of the Stanford Center for Sleep Sciences and Medicine, explains why and how insufficient sleep can increase your risk of weight gain:

It is very clear that if you’re not sleeping enough, you’re putting yourself at risk for increasing your weight.  If you sleep less than six hours a night, you’re likely to have a higher BMI (body mass index). Longitudinal data — and the evidence is quite strong — shows that if you sleep more over time, you’ll lower your BMI, which correlates with weight reduction.

In the first centuries of human life on earth, if humans weren’t sleeping they were probably looking for food or fleeing a predator. Not sleeping enough was a sign that we were in danger or that we were under stress. When we are sleep deprived, we feel hungry. Data indicates that if you sleep less, you eat more, and it disrupts your hormones. This problem is magnified in today’s world because food is too available!

Mignot also discusses the top reasons why people sleep so little, the importance of naps, and how being sleep-deprived skews our perception of doing and performing well. “[W]e have to make sure we don’t burn the candle at both ends, Mignot said. “Sleeping brings creativity, productivity and the ability to perform at a higher level.”

The piece is a quick, and informative, read.

Previously: Exploring the history and study of sleep with Stanford’s William Dement“Father of Sleep Medicine” talks with CNN about what happens when we don’t sleep wellStanford doc gives teens a crash course on the dangers of sleep deprivation, Narcoleptic Chihuahua joins Stanford sleep researcher’s family and More evidence linking sleep deprivation and obesity
Photo by Goodiez

Medical Education, Medical Schools, Mental Health, Stanford News

A call to action to improve balance and reduce stress in the lives of resident physicians

A call to action to improve balance and reduce stress in the lives of resident physicians

4086639111_a7e7a56912_zIn November of 2010, those in Stanford’s general surgery training program experienced an indescribable loss when a recently graduated surgical resident, Greg Feldman, MD, committed suicide. His death wound up being a call to action that brought about the Balance in Life program at Stanford, according to program founder Ralph S. Greco, MD.

With the Balance in Life program now in its fourth year, Greco; chief surgical resident Arghavan Salles, MD, PhD; and general surgery resident Cara A. Liebert, MD, have learned much about the daily stresses that resident physicians face. In a recent published JAMA Surgery opinion piece they wrote:

As physicians, we spend a significant amount of time counseling our patients on how to live healthier lives. Ironically, as trainees and practicing physicians, we often do not prioritize our own physical and psychological health.

A recent national survey found that 40% of surgeons were burnt out and that 30% had symptoms of depression. Another study reported that 6% of surgeons experienced suicidal ideation in the preceding 12 months. Perhaps most startling, there are roughly 300 to 400 physicians who die by suicide per year—the equivalent of 3 medical school graduating classes.

Greco, Salles and Liebert explain that the Balance in Life program is specifically designed to help resident physicians cope with these stresses by addressing the well-being of their professional, physical, psychological and social lives. To accomplish this goal, the program offers mentorship and leadership training activities; dining and health-care options that are tailored to the residents’ busy schedules and needs; confidential meetings with an expert psychologist; and social events and outdoor activities that foster support among residents.

The authors concede that the program may not fix every stressful problem that their residents face, but it does let the residents know that their well-being is important and valued. “This may be the most profound, albeit intangible, contribution of Balance in Life,” the authors write.

Although the program (and the JAMA article) is geared for people in the medical field, it’s not much of a stretch to see how its core principles can apply to any work setting. Learning how to manage stress and reach out to colleagues for support is a valuable skill and, as the authors write, to provide expert care for others you must first take good care of yourself.

Previously: After work, a Stanford surgeon brings stones to lifeSurgeon offers his perspective on balancing life and workProgram for residents reflects “massive change” in surgeon mentality, New surgeons take time out for mental health and Helping those in academic medicine to both “work and live well”
Photo by Gabriel S. Delgado C.

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