Duke Research Blog

Following the people and events that make up the research community at Duke.

Category: Medicine (Page 1 of 17)

Pinpointing Where Durham’s Nicotine Addicts Get Their Fix

DURHAM, N.C. — It’s been five years since Durham expanded its smoking ban beyond bars and restaurants to include public parks, bus stops, even sidewalks.

While smoking in the state overall may be down, 19 percent of North Carolinians still light up, particularly the poor and those without a high school or college diploma.

Among North Carolina teens, consumption of electronic cigarettes in particular more than doubled between 2013 and 2015.

Now, new maps created by students in the Data+ summer research program show where nicotine addicts can get their fix.

Studies suggest that tobacco retailers are disproportionately located in low-income neighborhoods.

Living in a neighborhood with easy access to stores that sell tobacco makes it easier to start young and harder to quit.

The end result is that smoking, secondhand smoke exposure, and smoking-related diseases such as lung cancer, are concentrated among the most socially disadvantaged communities.

If you’re poor and lack a high school or college diploma, you’re more likely to live near a store that sells tobacco.

If you’re poor and lack a high school or college diploma, you’re more likely to live near a store that sells tobacco. Photo from Pixabay.

Where stores that sell tobacco are located matters for health, but for many states such data are hard to come by, said Duke statistics major James Wang.

Tobacco products bring in more than a third of in-store sales revenue at U.S. convenience stores — more than food, beverages, candy, snacks or beer. Despite big profits, more than a dozen states don’t require businesses to get a special license or permit to sell tobacco. North Carolina is one of them.

For these states, there is no convenient spreadsheet from the local licensing agency identifying all the businesses that sell tobacco, said Duke undergraduate Nikhil Pulimood. Previous attempts to collect such data in Virginia involved searching for tobacco retail stores by car.

“They had people physically drive across every single road in the state to collect the data. It took three years,” said team member and Duke undergraduate Felicia Chen.

Led by UNC PhD student in epidemiology Mike Dolan Fliss, the Duke team tried to come up with an easier way.

Instead of collecting data on the ground, they wrote an automated web-crawler program to extract the data from the Yellow Pages websites, using a technique called Web scraping.

By telling the software the type of business and location, they were able to create a database that included the names, addresses, phone numbers and other information for 266 potential tobacco retailers in Durham County and more than 15,500 statewide, including chains such as Family Fare, Circle K and others.

Map showing the locations of tobacco retail stores in Durham County, North Carolina.

Map showing the locations of tobacco retail stores in Durham County, North Carolina.

When they compared their web-scraped data with a pre-existing dataset for Durham County, compiled by a nonprofit called Counter Tools, hundreds of previously hidden retailers emerged on the map.

To determine which stores actually sold tobacco, they fed a computer algorithm data from more than 19,000 businesses outside North Carolina so it could learn how to distinguish say, convenience stores from grocery stores. When the algorithm received store names from North Carolina, it predicted tobacco retailers correctly 85 percent of the time.

“For example we could predict that if a store has the word “7-Eleven” in it, it probably sells tobacco,” Chen said.

As a final step, they also crosschecked their results by paying people a small fee to search for the stores online to verify that they exist, and call them to ask if they actually sell tobacco, using a crowdsourcing service called Amazon Mechanical Turk.

Ultimately, the team hopes their methods will help map the more than 336,000 tobacco retailers nationwide.

“With a complete dataset for tobacco retailers around the nation, public health experts will be able to see where tobacco retailers are located relative to parks and schools, and how store density changes from one neighborhood to another,” Wang said.

The team presented their work at the Data+ Final Symposium on July 28 in Gross Hall.

Data+ is sponsored by Bass Connections, the Information Initiative at Duke, the Social Science Research Institute, the departments of mathematics and statistical science and MEDx. This project team was also supported by Counter Tools, a non-profit based in Carrboro, NC.

Writing by Robin Smith; video by Lauren Mueller and Summer Dunsmore

Not Your Basic Bench: Zebrafish Reveal Secrets of the Developing Gut

Our intestine is a highly complex organ – a tortuous, rugged channel built of many specialized cell-types and coated with a protective, slimy matrix. Yet the intestine begins as a simple tube consisting of a central lumen lined by a sheet of epithelial cells, which are smooth cells that lie on the surface of the lumen. These intestinal epithelial cells are central players in many human diseases.

A portrait of Daniel Levic

Daniel Levic, a postdoctoral research associate in the department of cell biology at the Duke University Medical Center.

Daniel Levic of the Bagnat Lab is using zebrafish as experimental models to understand how intestines are formed in hopes of finding new ways to combat disease. He wants to learn how the intestinal lumen forms during early development, and how intestinal epithelial cells take on their physiological functions.

Levic, a postdoctoral research associate in the department of cell biology at the Duke University Medical Center, focuses on projects in both basic and translational science. Daniel uses zebrafish to analyze the formation of the lumen and the polarity of epithelial cells — how specialized they are for carrying out different functions —  at the genetic and cellular level. He focuses on how membrane proteins are sorted into different, specialized domains of the cell surface and how this process affects intestinal formation. Additionally, Daniel studies how inflammation is evaded in intestinal epithelial cells in Crohn’s disease using a combination of patient biopsy samples and animal studies in zebrafish. This project is a collaborative effort aided by clinicians and human geneticists at the Duke University Medical Center.

A microscope image of a zebrafish gut

The developing gut of a zebrafish, magnified.

Though complex human diseases can’t be fully mimicked in animal models like zebrafish, this type of research can be extremely useful. These model organisms can be used to study the basic, fundamental cellular mechanisms that ultimately underlie disease. An example is Daniel’s work on Crohn’s disease, where he is trying to understand how inflammatory signaling networks become activated, specifically in intestinal epithelial cells. This problem is difficult, if not impossible, to address using exclusively human biopsy samples.

Overall, Daniel hopes that his translational research will provide new knowledge of the role of intestinal epithelial cells in Crohn’s disease and provide biomarkers that will aid clinicians in predicting how patients will respond to therapeutic interventions. Daniel’s research and basic science research are rapidly changing the way we diagnose disease, treat patients, and interact with the world around us.

Guest post by Vaishnavi Siripurapu

Lemur Research Gets a Gut Check

Baby Coquerel’s sifaka

Clinging to her mom, this baby Coquerel’s sifaka represents the only lemur species at the Duke Lemur Center known to fall prey to cryptosporidium, a microscopic parasite that causes diarrhea that can last for a week or more. The illness wipes out much of the animals’ gut microbiome, researchers report, but fecal transplants can help them recover. Photo by David Haring, Duke Lemur Center.

DURHAM, N.C. — “Stool sample collector” is not a glamorous way to introduce oneself at a party. But in the course of their research, gut microbiologists Erin McKenney and Lydia Greene have spent a lot of time waiting for animals to relieve themselves.

They estimate they have hundreds of vials of the stuff, from a dozen primate species including lemurs, baboons and gorillas, sitting in freezers on the Duke University campus.

The researchers aren’t interested in the poop per se, but in the trillions of bacteria inhabiting the gastrointestinal tract, where the bugs help break down food, produce vitamins and prevent infection.

A few years ago, McKenney and Greene started collecting stool samples at the Duke Lemur Center to see how the microbial makeup of lemurs’ guts varies from birth to weaning, and as their diets change over the seasons. And what happens when they get sick?

Illustration of Cryptosporidium, a widespread intestinal parasite that causes diarrhea in people, pets, livestock and wildlife worldwide. Courtesy of the U.S. Centers for Disease Control.

Illustration of Cryptosporidium, a widespread intestinal parasite that causes diarrhea in people, pets, livestock and wildlife worldwide. Courtesy of the U.S. Centers for Disease Control.

Between 2013 and 2016, ten of the lemurs they were studying contracted cryptosporidium, or “crypto” for short, a waterborne parasite that causes diarrhea in people, pets, livestock and wildlife worldwide.

All of the infected animals were Coquerel’s sifakas — the only lemur species out of roughly 20 at the Duke Lemur Center known to fall prey to the parasite — and most of them were under five years old when they fell ill.

Animals that tested positive were moved into separate holding areas away from other animals and visitors. Keepers wore protective suits, gloves, face masks and booties while working in the animals’ enclosures to prevent infection.

All of the animals eventually recovered. Along the way, six of the affected animals were treated with antibiotics, and three were also fed a slurry of saline and feces from a healthy relative.

McKenney and Greene collected stool samples before, during and after infection for up to two months. They used a technique called 16S ribosomal RNA sequencing to identify the types of bacteria in the samples based on their genes, and compared the results with those of 35 unaffected individuals.

In a healthy gut microbiome, “good” bacteria in the gut compete with “bad” microbes for space and nutrients, and secrete substances that inhibit their growth.

The guts of sick and recovering sifakas are host to a very different assortment of microbes than those of unaffected animals, the researchers found.

Not surprisingly, both crypto infection, and antibiotic treatment, wiped out much of the animals’ gut flora — particularly the bacterial groups Bifidobacterium, Akkermansia, Succinivibrio and Lachnospiraceae.

Even after the infections cleared, most animals took another several weeks to stabilize and return to normal levels of gut biodiversity, with younger animals taking longer to recover.

The only animals that made a full comeback within the study period were those that received a fecal transplant, suggesting that the treatment can help restore gut bacterial diversity and speed recovery.

The patterns of gut recolonization following crypto infection mirrored those seen from birth to weaning, said McKenney, now a postdoctoral researcher at North Carolina State University.

The researchers hope their findings will help control and prevent crypto outbreaks in captive primates. Because lemurs are more closely related to humans than lab mice are, the research could also help scientists understand how the gut microbiome protects humans from similar infections and facilitates recovery.

“Thanks to bioinformatics and advances in sequencing, the microbiome gives us a window into the health of these animals that we’ve never had before,” said Greene, a graduate student in ecology at Duke.

They published their findings June 15, 2017, in the journal Microbial Ecology in Health and Disease.

Duke evolutionary anthropology professors Christine Drea and Anne Yoder were senior authors on this study. This research was supported by the National Science Foundation (1455848) and the Duke Lemur Center Directors Fund.

CITATION:  “Down for the Count: Cryptosporidium Infection Depletes Gut Microbiota in Coquerel’s Sifakas,” Erin McKenney, Lydia Greene, Christine Drea and Anne Yoder. Microbial Ecology in Health and Disease, June 15, 2017. http://dx.doi.org/10.1080/16512235.2017.1335165

Post by Robin Smith, science writer, Office of News & Communications

If the Cancer Doesn’t Kill You, the Drug Prices Might

The medical community is growing alarmed about a creeping malady that can diminish the quality of life for patients in treatment and even shorten their lives.

It’s found everywhere in the United States, but not to the same degree in other developed countries. They’re calling it “Financial Toxicity.”

Yousuf Zafar is an oncologist and health policy researcher.

A cancer diagnosis more than doubles an American’s chance of declaring bankruptcy, Duke medical oncologist  Yousuf Zafar, MD, MHS,  told an audience of nursing faculty and students at a May 10 luncheon lecture sponsored by the Duke Center for Community and Population Health Improvement. And that bankruptcy, in turn, has been shown to decrease survival rates.

In addition to treating cancer patients, Zafar studies access to care and the cost of care at the Duke Cancer Institute, the Sanford School of Public Policy, and the Margolis Center for Health Policy.

Zafar told personal stories of two patients who waved off treatments because of the financial hardship they feared.

Gleevec (Imatinib) is an oral chemotherapy made by Novartis.

One of them had a job with health insurance, but no prescription drug coverage, which put him on the hook for $4,000 in medications to treat his rectal cancer for just a few weeks. Had either the patient or Dr. Zafar brought the topic up, the costs might have been avoided, but they never talked about money, he said.

The other patient passed up another round of treatment for his pancreatic cancer, for fear of the bills his family would be saddled with when he died.

Chemotherapy for cancer would typically cost $100/month in the 1970s, Zafar said. But today that figure can be “ten, or tens, of thousands per month.” (Inflation would make that 1970 dollar about $6, not $600.)

“Pricing in the European Union and the rest of the world is a completely different picture,” he said.  In the US, pricing “simply reflects what the market will bear.”

Another source of the steep climb is the advent of biologic drugs, which are expensive to develop, use and store, but offer more targeted therapy for individual patients. One of the most successful of these is Gleevec (Imatinib) an oral chemotherapy that became 158 percent more expensive from 2007 to 2014, Zafar said.

If you do a Google search for Gleevec, the first thing you find is a Novartis page with the headline “Understand Your Out-Of-Pocket Costs For Gleevec” that includes a link to financial assistance resources.

In the face of outrageous costs and questionable benefits, a treatment team in many cases can help patients find other means of support or alternative treatments to achieve the same end with less financial damage. But they have to have the conversation, Zafar said. He’d like to see Duke’s Cancer Center become the first in the country to be totally transparent about costs, but he acknowledged that it may be a difficult quest.

To help enable those conversations, Zafar developed a mobile app called Pathlight to help patients make more informed decisions and plan better for the financial burden of treatment. For some of the technology used in the project, Zafar has partnered with a software company called Vivor, which has found innovative ways to help patients navigate to financial assistance programs. That part of the project is supported by the NIH’s National Cancer Institute.

Even for people not in treatment, drugs have become more costly. Healthcare premiums rose 182 percent from 1999 to 2013, with workers paying an increasing share of the cost of their own employee health plans.

Is this any way to run a health system?

“I don’t have all the answers – I don’t think anybody does,” Zafar said. “But I think we need to move toward a single-payer system.”

Post by Karl Leif Bates

 

Closing the Funding Gap for Minority Scientists

DURHAM, N.C. — The barriers to minority students in science, technology, engineering and math (STEM) don’t go away once they’ve finished school and landed a job, studies show. But one nationwide initiative aims to level the playing field once they get there.

With support from a 3-year, $500,0000 grant from the National Science Foundation, assistant professors and postdoctoral fellows who come from underrepresented minorities are encouraged to apply by May 5 for a free grant writing workshop to be held June 22-24 in Washington, D.C..

It’s no secret that STEM has a diversity problem. In 2015, African-Americans and Latinos made up 29 percent of the U.S. workforce, but only 11 percent of scientists and engineers.

A study published in the journal Science in 2011 revealed that minority scientists also were less likely to win grants from the National Institutes of Health, the largest source of research funding to universities.

Based on an analysis of 83,000 grant applications from 2000 to 2006, the study authors found that applications from black researchers were 13 percent less likely to succeed than applications from their white peers. Applications from Asian and Hispanic scientists were 5 and 3 percent less likely to be awarded, respectively.

Even when the study authors made sure they were comparing applicants with similar educational backgrounds, training, employers and publication records, the funding gap persisted — particularly for African-Americans.

Competition for federal research dollars is already tough. But white scientists won 29 percent of the time, and black scientists succeeded only 16 percent of the time.

Pennsylvania State University chemistry professor Squire Booker is co-principal investigator of a $500,000 initiative funded by the National Science Foundation to help underrepresented minority scientists write winning research grants.

“That report sent a shock wave through the scientific community,” said Squire Booker, a Howard Hughes Medical Institute investigator and chemistry professor at Pennsylvania State University. Speaking last week in the Nanaline H. Duke building on Duke’s Research Drive, Booker outlined a mentoring initiative that aims to close the gap.

In 2013, Booker and colleagues on the Minority Affairs Committee of the American Society for Biochemistry and Molecular Biology decided to host a workshop to demystify the grant application process and help minority scientists write winning grants.

Grant success is key to making it in academia. Even at universities that don’t make funding a formal requirement for tenure and promotion, research is expensive. Outside funding is often required to keep a lab going, and research productivity — generating data and publishing results — is critical.

To insure underrepresented minorities have every chance to compete for increasingly tight federal research dollars, Booker and colleagues developed the Interactive Mentoring Activities for Grantsmanship Enhancement program, known as IMAGE. Program officers from NIH and NSF offer tips on navigating the funding process, crafting a successful proposal, decoding reviews and revising and resubmitting. The organizers also stage a mock review panel, and participants receive real-time, constructive feedback on potential research proposals.

Participants include researchers in biology, biophysics, biochemistry and molecular biology. More than half of the program’s 130 alumni have been awarded NSF or NIH grants since the workshop series started in 2013.

Booker anticipates this year’s program will include more postdoctoral fellows. “Now we’re trying to expand the program to intervene at an earlier stage,” Booker said.

To apply for the 2017 workshop visit http://www.asbmb.org/grantwriting/.  The application deadline is May 5.

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Post by Robin Smith

Bass Connections and GHANDI – Understanding Disability from a Global Perspective

Duke prides itself on being a research institution that is not only intellectually curious, but also extremely interdisciplinary. Through Duke’s Bass Connections initiative, students and faculty come together in project teams that tackle complex issues using multiple disciplines and approaches. The program held its annual fair last week to showcase its work and to get new students connected with these exciting projects.

How does it work?

Graduate students, undergraduates, and faculty members apply for a research project in any of these five areas: Brain and Society, Information Society & Culture, Global Health, Education & Development, and Energy. Once accepted, group members work on a year-long research project, that often includes a field work component. One project in particular that combines many disciplines and interests to address an issue of global importance GANDHI, a Global Health project that studies disability from multiple cultural perspectives.

What is GANDHI?

GANDHI team members meet with Dr. Rune Simeonsson at UNC to discuss the WHO ICF-CY (International Classification of Functioning – Children and Youth), a document he helped co-write that provides a framework for diagnosing and addressing disability.

The Global Alliance on Disease and Health Innovation (GANDHI) was created in 2016 to support disabled individuals by providing them with the community reintegration tools necessary to live a healthy, comfortable life. Yukhai Lin, a Duke undergrad and GANDHI team member, shared that many hospital systems are not good at helping those the disabled reintegrate themselves in their community, and often forget about their patients after they are released. The research team recognized this flaw, and began a thorough data collection process to understand the reason for this lack of care. In the fall of 2016, team members took a seminar course, “Living with Disability Around the Globe”, in which they were paired with global partners in ten different countries to examine disability from a more specific context. In this interdisciplinary class, team members not only strengthened their knowledge of disability and its implications on global societies, but they were also able to develop strong research skills, for they ultimately synthesized their findings by creating a thorough comparison of disability in each of the countries studied.

The team also attended a conference in New Orleans to network with organizations that were conducting similar research. Lin said she interviewed doctors from The Netherlands, as well as leaders of influential health organizations to holistically understand the issues that come with helping the disabled. The team hopes to present their findings at a forum this spring, and, like many other Bass Connection projects, will continue throughout the 2017-2018 academic year. They encourage all to apply, and hope to broaden the scope of their research by adding countries in Southeast Asia and creating new opportunities for fieldwork. Some eager students have already showed interest in going to China to interview families with disabled members, says Lin.

Other Bass Connections projects at the fair spread across all disciplines, ranging from the development of effective chemotherapy drugs to the study of urban development in cities across the globe. But, what all projects share in common is a strong emphasis on research that is hands-on, collaborative, and relevant to society.

 

Post by Lola Sanchez-Carrion

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