Research Briefs

Using single-cell sequencing and spatial transcriptomics in lung cancer tissue, researchers at the Geisel School of Medicine at Dartmouth, led by Principal Investigator Claudia Jakubzick, PhD, discovered that macrophages divide labor inside the tumor partially based on location. 

They also found that it’s possible to target these macrophage subpopulations. In a cancer vaccine mouse model, the researchers found that administering maraviroc, an FDA-approved HIV drug, substantially reduced the levels of the macrophages that promote tumor growth. 

The results, published in Nature Immunology in March 2026, could allow researchers to create better, more precise treatments that target harmful immune cells rather than eliminating entire immune cell populations. 

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Improving Emergency Care for Rural Youth at Risk of Suicide

Adolescents in rural communities are twice as likely to die by suicide as their urban counterparts. Youth in rural areas often rely on emergency departments for mental health crises, yet these departments are not always well equipped to help. 

To improve crisis care in rural areas, researchers at the Geisel School of Medicine at Dartmouth, Dartmouth Health Children’s, and Dartmouth Health, led by JoAnna K. Leyenaar, MD, MPH, PhD, a pediatric hospitalist at Dartmouth Hitchcock Medical Center and the Batalden Distinguished Chair in Healthcare Improvement at The Dartmouth Institute for Health Policy & Clinical Practice, with the assistance of Geisel medical students Nikolas G. Hernandez MED ’28, Alyssa Helmling MED ’28, and Emma Jacobs MED ’28, developed the Plan & Protect program. 

This safety planning program, tailored to the needs and lived experiences of rural youth, provides digital resources for emergency departments in rural areas that may have limited resources. By interviewing adolescents ages 12 to 17, the researchers narrowed in on simple, engaging tools that allowed for more user-centered interventions specific to rural youth who face challenges including stigma, a need for connection, and privacy concerns. 

The program was presented at the Pediatric Academic Societies 2026 Meeting, held in Boston in April 2026, and at the Vermont Medical Society 2025 conference, where the team received the first-place oral presentation award. 

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Keeping the Weight Off After GLP-1s

GLP-1 medications like Ozempic, popular for treating obesity and type 2 diabetes, can be tremendously successful in helping patients lose weight. However, they’re not a cure: Within 18 months of stopping medication, most former GLP-1 patients regain the pounds they had shed. 

But a new study led by Dartmouth Health gastroenterologist Shelby A. Sullivan, MD, identified a procedure that can help those patients keep the weight off. Known as duodenal mucosal resurfacing, this procedure targets the innermost lining of the small intestine, using heat to burn off unhealthy parts of the lining that are commonly caused by the typical Western diet. 

In a clinical trial presented at the Digestive Disease Week conference in Chicago in May 2026, patients who underwent duodenal mucosal resurfacing kept off over 80% of the weight they had lost on GLP-1s. Following the patients over six months after the procedure also showed that the difference in regained weight between the treated and control groups increased, suggesting that the procedure can help with longer-term weight maintenance. The trial also showed no serious complications, and recovery time from the procedure was only a day to recoup from anesthesia. These findings could bring hope to patients wishing to stop taking GLP-1s long-term, whether due to side effects, cost, or other reasons. 

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Video Games Designed to Reduce Teen Depression

Video games get a bad rap, but new research found that educational games can be highly effective in treating and preventing depression in adolescents. Led by Lynn Fiellin, MD, professor at the Geisel School of Medicine at Dartmouth, the researchers tracked more than 500 high school students to see the effects of playing an hour of video games per day for six weeks.  

In the study, half of the students played commercial role-playing games and half played PlaySmart, a digital game with therapeutic content developed by the researchers themselves. In PlaySmart, players navigate tasks and choices, like identifying signs of depression or turning to an adult for help, ultimately making better choices that lead to more positive outcomes. 

A year later, teenagers in the PlaySmart group reported fewer depressive symptoms and better attitudes toward seeking psychological care. The results, published in August 2026 in JAMA Network Open, were as good as or better than general school-based programs. The researchers believe that behavioral games like PlaySmart have tremendous potential in helping more adolescents access care, especially in places where traditional mental health services are limited or stigmas are high. 

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Alpha-gal Syndrome Can Cause Severe Allergic Reactions After Transfusions 

Alpha-gal syndrome—the tickborne disease best known for triggering life-threatening meat allergies—can increase risks to some patients receiving blood plasma and platelet transfusions, according to new research led by Dartmouth Health and the Geisel School of Medicine at Dartmouth.