Duke Research Blog

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

Author: Sarah Haurin

Long-Term Study Sees the Big Picture of Cannabis Use

Seventy percent of the United States population will have tried marijuana by the age of 30. As the debate on the legalization of the most commonly used illicit drug continues throughout the country, researchers like William Copeland, PhD, and Sherika Hill, PhD, from the Duke Department of Psychiatry and Behavioral Sciences are interested in patterns of marijuana use and abuse in the first 30 years of life.

Marijuana is the most commonly used illicit drug.

The Great Smoky Mountain Study set out in 1992 to observe which factors contributed to emotional and behavioral problems in children growing up in western North Carolina. The study included over 1,000 children, including nearly 400 living on the Cherokee reservation. In addition to its intended purpose, the data collected has proven invaluable to understanding how kids and young adults are forming their relationship with cannabis.

The Great Smoky Mountains Study collected extensive medical and behavioral research from 11 counties in western North Carolina.

Using the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) and patterns of daily use of the drug, Copeland and Hill found some unsurprising patterns: peak use of the drug is during young adulthood (ages 19-21), when kids are moving out of the home to college or to live alone.

But while most people adjust to this autonomy and eventually stop their usage of the drug, a small percentage of users (7%) keep using into their adulthood. Hill and Copeland have observed specific trends that apply both to this chronic user group as well as an even smaller percentage of users (4%) who begin using at a later stage in life than most people, termed the delayed-onset problematic users.

Looking at the demographics of the various types of users, Hill and Copeland found that males are twice as likely to engage in marijuana use to any extent than females. Of those who do use the drug, African Americans are five times more likely to be delayed-onset users, while Native Americans are twice as likely to decrease their use before it becomes problematic.

For both persistent and delayed-onset problematic users, family instability during childhood was 2-4 times more likely than in non-problematic users.

Persistent users were more likely to have endured anxiety throughout childhood, and delayed-onset users were more likely to have experienced some kind of trauma or maltreatment in childhood than other types of users.

The identification of these trends could prove a vital tool in predicting and preventing marijuana abuse, and the importance of this understanding is evidenced in the data collected that elucidates outcomes of marijuana use.

Looking at various measures of social and personal success, the team identified patterns with a resounding trend: recent use of marijuana is indicative of poorer outcomes. Physical health and financial or educational outcomes displayed the worst outcomes in chronic and delayed-onset users. Finally, criminal behavior was increased in every group that used; in other words, regardless of the extent of use, every group with use of marijuana fared worse than the group that abstained.

The results of Copeland and Hill’s work has important implications as legislators debate the legalization of marijuana. While understanding these patterns of use and their outcomes can provide useful insight on the current patterns of usage, decriminalization will certainly change the way marijuana is manufactured and consumed, and will thus also affect these patterns.
By Sarah Haurin

Creative Solutions to Brain Tumor Treatment

Survival rates for brain tumors have not improved since the 1960s; NIH Image Gallery.

Invasive brain tumors are among the hardest cancers to treat, and thus have some of the worst prognoses.

Dean of the Pratt School of Engineering, Ravi Bellamkonda, poses for his portrait inside and outside CIEMAS.

Displaying the survival rates for various brain tumors to the Genomic and Precision Medicine Forum on Thursday, Oct. 26, Duke professor Ravi Bellamkonda noted, “These numbers have not changed in any appreciable way since the 1960s.”

Bellakonda is the dean of the Pratt School of Engineering and a professor of biomedical engineering, but he is first a researcher. His biomedical engineering lab is working toward solutions to this problem of brain tumor treatment.

Unlike many other organs, which can sacrifice some tissue and remain functional, the brain does not perform the same way after removing the tumor. So a tumor without clearly defined boundaries is unsafe to remove without great risk to other parts of the patient’s brain, and in turn the patient’s quality of life.

Bellakonda hypothesized that brain tumors have characteristics that could be manipulated to treat these cancers. One key observation of brain tumors’ behavior is the tendency to form along white matter tracts. Put simply, tumors often spread by taking advantage of the brain’s existing structural pathways.

Bellakonda set out to build a device that would provide brain tumors a different path to follow, with the hope of drawing the tumor out of the brain where the cells could be killed.

The results were promising. Tests on rats and dogs with brain tumors showed that the device successfully guided out and killed tumor cells. Closer examination revealed that the cells killed were not cells that had multiplied as the tumor grew into the conduit, but were actually cells from the primary tumor.

The Bellamkonda lab’s device successfully guided and killed brain tumors in rats.

In addition to acting as a treatment device, Bellakonda’s device could be co-opted for other uses. Monitoring the process of deep brain tumors proves a difficult task for neurooncologists, and by bringing cells from deep within the tumor to the surface, this device could make biopsies significantly easier.

Although the device presents promising results, Bellakonda challenged his lab to take what they have learned from the device to develop a less invasive technique.

Another researcher in the Bellakonda lab, Tarun Saxena, engaged in research to utilize the body’s natural protection mechanisms to contain brain tumors. Creating scar tissue around tumors can trick the brain into treating the tumor as a wound, leading to immunological responses that effectively contain and suppress the tumor’s growth.

Visiting researcher Johnathan Lyon proposed utilizing electrical fields to lead a tumor to move away from certain brain regions. Moving tumors away from structures like the pons, which is vital for regulation of vital functions like breathing, could make formerly untreatable tumors resectable. Lyon’s 3D cultures using this technique displayed promising results.

Another Bellakonda lab researcher, Nalini Mehta, has been researching utilizing a surprising mechanism to deliver drugs to treat tumors throughout the brain: salmonella. Salmonella genetically engineered to not invade cells but to easily pass through the extracellular matrix of the brain have proven to be effective at delivering treatment throughout the brain.

While all of these therapies are not quite ready to be used to treat the masses, Bellakonda and his colleagues’ work presents reasonable hope of progress in the way brain tumors are treated.

By Sarah Haurin

Piloting Aviation Mental Healthcare

With more than 100,000 flights taking off per day, the safety of air travel is a far-reaching issue.

Air travel remains one of the safest forms of transportation, but are there things we can do to make it safer?

While air travel is by far the safest method of transportation — you are more likely to die from a car crash or even a shark attack than from an airplane crash — accidents do happen and can result in highly publicized fatalities.

Chris Kenedi is working with the ICAO to improve treatment of mentally ill pilots.

Auckland Hospital internist and psychiatrist Chris Kenedi, MD, MPH, is working with the International Civil Aviation Organization (ICAO) to improve safety of air travel by focusing on an issue that is usually only questioned in instances of tragedy: the mental health of pilots.

While screening procedures do currently exist, they are not enough for the extent of risk factors that are present in the pilot population.
Being a pilot is a high-stress job. It involves long hours, separation from family, and irregular sleep schedules, all of which can contribute to or exacerbate mental conditions.

Many pilots experiencing symptoms are unwilling to ask for help, because admitting mental illness can lead to a pilot’s license being revoked, which would not only affect financial circumstances but also be felt as a loss of identity.

Although data regarding aviation mental health is sparse, what is available suggests  mental health issues are among the greatest contributing factors to suicide and homicide-suicide incidents of plane accidents.

When Kenedi completed a systematic review of all data on the mental health of pilots and the current standard procedures, he found a deeply flawed system. Case studies of crashes caused by suicidal pilots showed that psychiatrists cleared them for flight even after episodes indicating a much deeper psychological imbalance.

One pilot who drove his car into a barrier, attempted to steal the car of a woman trying to help him, and slit his wrists so deeply that he required two years of rehabilitation before regaining all of his mobility, was diagnosed with a general anxiety disorder and cleared to fly without proper treatment.

In order to prevent further grave oversights, Kenedi suggests requiring the psychiatrist who assesses a pilot’s ability to fly to be separate from the treating psychiatrist. This separation prevents the assessing psychiatrist from having his or her judgement confounded by a relationship with the patient and thus becoming an advocate rather than an impartial assessor.

Kenedi said that alcohol and substance abuse treatments for pilots have been effective, however. Rather than relying on random drug and alcohol tests to disqualify impaired pilots, the system provides non-judgmental treatment and an opportunity to return to piloting.

Kenedi recommends a shift to treating mental illness in pilots in a similar way, so that individuals are not afraid to step forward and ask for help. Educating mental healthcare providers is also important, so that pilots are receiving the best care possible.

With proper resources and treatment, pilots with mental health concerns should be able to maintain their identity as pilots while gaining renewed resilience and support through the mental health system. This shift would hopefully help to prevent some of the small amount of air travel accidents that occur because of pilot issues.

By Sarah Haurin

 

How Climate Change Limits Educational Access

Regions with agricultural economies suffer greatly from climate change.

The effects of climate change can creep into nearly every aspect of life in heavy-hit areas. They may even limit children’s access to education, says Nicholas School of the Environment graduate Heather Randell.

“Investments in education are an important pathway out of poverty, yet lack of access remains a barrier,” Randall said in a presentation to Nicholas School students and faculty.

Randell became interested in the relationship between climate change and education when she visited Ethiopia before pursuing her doctorate. She noticed many school-age kids were working rather than pursuing an education, and began to wonder what factors influence children’s time use.

Heather Randell PhD is a sociologist and demographer for the National Socio-Environmental Synthesis Cener (SESYNC).

Although the UN’s Millennium Development Goals and Beyond 2015 aimed to ensure universal primary education for all school-age children, 20 percent of children in Sub-Saharan Africa were still out of school in 2017.

Using data from the Ethiopian Rural Household Survey, Randell found that when children experience milder temperatures and more ample rainfall during their early life, they are more likely to stay in school longer. This trend can be attributed to the close ties between the economy and climate in agricultural areas like those in rural Ethiopia.

Agricultural economies are inherently dependent on temperature and rainfall. Increased temperature and decreased rainfall lower crop yield, which in turn decreases individual families’ incomes.

Children in Ethiopia are less likely to continue their education if they experienced hotter temperatures and less rainfall in their early childhood.

With less disposable income, families are more likely to spend their money on necessities like food rather than on schooling fees. Families are also more likely to pull children out of school so kids can work and contribute to the diminished family income.

After finding these patterns in Ethiopia, Randell expanded her research to include regions in the tropics, including Central America, the Caribbean, South America, East Africa, West Africa and Southeast Asia. Each of these regions has variations in their typical rainfall and temperatures, but all are inherently susceptible to climate change because of their location near the equator.

From her research in Ethiopia, Randell found two mechanisms by which climate change influences educational outcomes.

Comparing standardized census and climate data from these regions, Randell found a similar pattern, with increased temperature and changes in rainfall being associated with decreased educational outcomes.

This study also found that climate change and its negative effects often outweigh typical advantages that improve educational access, such as parents who have had a longer schooling.

Randell concluded her talk by stating that true and lasting change to educational accessibility will only be brought about by policy change. School must be less expensive and more accessible, and more importantly, livelihood diversification must be taught and encouraged. Families must learn how to generate income in ways other than agriculture so that their income and familial decisions are more resilient to climate variability.

By Sarah Haurin

Rare Cancers and Precision Medicine in Southeast Asia

Data collected through genomics research is revolutionizing the way we treat cancer. But a large population of cancer patients are being denied the benefits of this research.

Patrick Tan MD, PhD is a professor of cancer and stem cell biology at Duke-NUS Medical School in Singapore.

In 2016, less than one percent of all the existing genomic data came from the 60% of the world population living outside of the US, Europe, and Japan. Furthermore, 70% of patients who die from cancer this year will come from Asia, Africa and Central and South America.

Patrick Tan, M.D., Ph.D., and the Duke-National University of Singapore (Duke-NUS) Medical School are key players in an effort to rectify this discrepancy, specifically as it exists in Southeast Asia.

In his talk, sponsored by the Duke Center for Applied Genomics and Precision Medicine, Tan focused specifically on his work in northeast Thailand with cholangiocarcinoma (CCA), or bile duct cancer.

Liver fluke

Liver flukes like this are parasites of fish that migrate to human hosts who eat the fish raw, leading to a form of bile duct cancer.

While CCA is rare in most of the world, it appears at 100 times the global rate in the region of Thailand where Tan and his colleagues work. Additionally, CCA in this region is of a separate and distinct nature.

CCA in this region is linked with a parasitic infection of the bile ducts called a liver fluke.  Residents of this area in Thailand have a diet consisting largely of raw fish, which can be infected by the liver fluke and transmitted to the person who eats the fish.

Because of the poverty in this area, encouraging people to avoid eating raw fish has proven ineffective. Furthermore, healthcare is not readily available, so by the time most patients are diagnosed, the disease has progressed into its later and deadly stage.

The life cycle of liver flukes. (Graphic U.S. Centers for Disease Control)

Tan’s genomic research has discovered certain factors at the gene level that make liver-fluke positive CCA different from other CCA. Thus genomic data specific to this population is vital to improve the outcomes of patients with CCA.

Duke-NUS Precision Medicine (PRISM) has partnered up with the National Heart Research Institute Singapore (NHRIS) in SPECTRA, a program designed to create a database of genomic data from the healthy Asian population. SPECTRA is sequencing the genomes of 5,000 healthy Asians in order to create a baseline to which they can compare the genomes of unhealthy individuals.

These and other programs are part of a larger effort to make precision medicine, or healthcare tailored to an individual based on factors like family history and genomic markers, accessible throughout southeast Asia.

By Sarah Haurin

 

Disaster Plans and the Mentally Ill

Houston, Miami, San Juan — Category 5 hurricanes, the most destructive storm systems, have made a record-breaking 6 landfalls this year. This represents a quarter of the total category 5 hurricane landfalls that the Atlantic has seen since 1851.

With statistics like these, disaster relief plans are becoming more important than ever. But do these plans do enough for marginalized groups, specifically the mentally ill?

Allan K. Chrisman, M.D., believes more can be done. As a career psychiatrist who has been deployed by the Red Cross in the aftermath of storms like Katrina and Matthew, Chrisman has seen and experienced the importance of including the mentally ill in disaster relief plans.

At his talk to physicians in Duke’s Hospital on Sept. 28, Chrisman, an emeritus  professor at Duke, highlighted specific aspects of disaster relief that are not doing enough for the one in four U.S. adults suffering from mental illness each year.

According to Chrisman, this part of the population is often less prepared for impending storms. When storms do hit, existing symptoms can be exacerbated, or new symptoms can appear.  Disruption of routine, inconsistency of taking medication and the overall stress that comes with emergencies all contribute to this exacerbation of mental illness.

While the Red Cross has an “everyone is welcome,” policy for their shelters, not being able to identify the needs of the mentally ill seeking sanctuary limits the organization’s ability to help. As a deployed psychiatrist, Chrisman worked with displaced mentally ill people to ensure they continued to get the care they needed even during the stress of a weather emergency.

One tool used by Chrisman and his colleagues to help these groups is the C-MIST framework. This system categorizes “functional-based needs” based on communication, maintaining health, independence, service and support, and transportation. It seeks to ensure not only that individuals are being given an option for a safe space in the wake of emergencies, but also that these spaces offer them the specific services they require.

Chrisman emphasized the need “to provide round-the-clock access to qualified mental health resources.”

He said that by following these inclusive protocols, disaster relief programs can do even more to protect the most vulnerable parts of the population.

By Sarah Haurin

Happy Patients, Healthy Lungs

Lung-shaped leaves

Evaluating a patient’s mental health before and after lung transplant surgery can help improve long-term outcomes. Source: tikyon, Flickr.

Diseases like Chronic Obstructive Pulmonary Disease (COPD) and Cystic Fibrosis (CF) are hard to treat. Lung transplant is important option for people who do not benefit from other treatments, and understanding the outcomes for these patients is crucial.

Patrick Smith, PhD, a clinical psychologist at Duke Hospital, shared his research into predictors for outcomes of lung transplant with a group of transplant physicians and surgeons at the Duke Hospital on Sept. 14.

“Patients receive transplants to live longer and to feel better,” Smith said.

Focus on the first goal has increased the median survival time after a lung transplant to six years. But Smith began his research because of an interest in the second goal.

An incredibly complex, long, and difficult procedure, transplants require extensive testing and therapies before a patient enters the operating room (OR). Among the pre-operative testing is a mental health assessment to determine if any psychological issues exist that could make recovery more difficult. Mental health issues can affect adherence, or a patient’s commitment to continuing the prescribed post-op medication after release from the hospital.

Smith’s research found that some of these tests can be incredibly useful at predicting outcomes not previously explored; patients who show cognitive impairments before surgery were found to be more likely to fall victim to delirium, a post-operative state of confusion and psychosis that has been linked to an increased risk of complications and death.

While acknowledging the usefulness of pre-operative testing, Smith also pointed out the inadequacy of this model. Failing to continue psychological assessments after the surgery and throughout the recovery means that doctors are missing important clues that could indicate how well patients will recover.

Through his research, Smith has found that the presence of depressive symptoms after transplant is actually a much more useful and accurate tool for predicting risk of mortality than symptoms exhibited before surgery.  

This point is strengthened by a previous study that found that successful treatment of depressive symptoms in liver transplant patients reduced the mortality rate of depressive patients to that of their non-depressive counterparts.

These results are promising for the possibility of improving transplant outcomes; by valuing and treating both pre-operative and post-operative signs of risk, doctors can improve the outcomes for their patients and ensure the limited supply of organs is being used in the best and most successful way possible.

Post by Sarah Haurin

 

 

New Blogger Sarah Haurin, Neuroscience Sophomore With a Thing for Criminal Minds

Hello! My name is Sarah Haurin (rhymes with Heron), and I am a sophomore at Duke. Along with being pre-med, I am pursuing a double major in neuroscience and German. I grew up outside of Philadelphia, Pennsylvania, and I originally fell in love with Duke both because of its vast research opportunities and also its mild winters. In grade school, a requirement to read nonfiction books led me to start reading popular science books for fun. Beginning with books about forensic science and articles about the chemistry of cooking, I soon expanded my interest to include natural and health sciences.

Since then, I have discovered my favorite genres to be abnormal psychology and biomedical research (my favorites being You Are Not So Smart and The Psychopath Whisperer), which interestingly enough make great beach reads (as evidenced by this picture of me from my family’s most recent vacation to Hilton Head Island, SC). In high school, I decided to take this love of reading scientific literature to a new place, and I joined the school newspaper, which allowed me to share recent and exciting findings with my peers through my articles in our health and science pages.

Sarah reading non-fiction at the beach.

I have always loved writing, which is what originally led me to joining my high school newspaper, and through my roles as section editor and eventually editor-in-chief, I came to appreciate the whole writing and publishing process. At Duke, I have written several articles for The Chronicle about the impressive and diverse ongoing research going on here at Duke.

I hope that being a well-rounded person, by allowing myself to enjoy activities not directly related to my majors, will eventually help me to be a better doctor, but for now I just enjoy the ability to combine my loves of writing and science. I hope to be able to further pursue this combination by writing for the Duke Research Blog.

One of the aspects of Duke’s community that I love the most is its diversity, which extends from the people who make up the student and faculty to the passions and interests that they pursue. I hope that writing for the Duke Research Blog will provide me with the opportunity to meet more of the incredibly passionate people who make up Duke’s campus.

Post by Sarah Haurin

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