News Highlights - August 18, 2026
Announcements
Bickel to Focus on Research after Stepping Down as Chief of Endocrinology
After nearly 14 years as Chief of the Division of Endocrinology, Perry Bickel, M.D., will step down from the role effective Sept. 1 to devote more time to his research.
Dr. Bickel joined UT Southwestern in 2012 and has led the Division through a period of growth across its clinical, research, and educational missions. Under his leadership, the Division expanded its clinical programs and developed collaborations across departments, divisions, and clinical sites to improve endocrine and diabetes care. The Division also launched new programs in obesity medicine, diabetes care, and interventional thyroid procedures while recruiting and developing faculty who have become leaders within UT Southwestern and the broader endocrinology community.
An internationally recognized physician-scientist, Dr. Bickel holds the Daniel W. Foster, M.D., Distinguished Chair in Internal Medicine and leads a research program focused on the mechanisms of cellular lipid metabolism. His work has advanced understanding of how cells store, mobilize, and utilize fat and has helped define the role of lipid droplets as active regulators of metabolism rather than passive storage sites. Among his most significant contributions are pioneering discoveries involving the Perilipin family of lipid droplet proteins, including Perilipin 5, which have provided important insights into the regulation of mitochondrial function, energy balance, obesity, and diabetes.
Dr. Bickel has also made significant contributions to the Department’s educational mission, including serving as Program Director of the Endocrinology, Diabetes, and Metabolism Fellowship, where he led a comprehensive redesign of the fellowship curriculum. He continues to serve as Associate Program Director of the NIH-supported Endocrine and Metabolism Training Grant and has mentored numerous fellows, graduate students, and junior faculty.
“Dr. Bickel has provided thoughtful and effective leadership to the Division of Endocrinology while maintaining an internationally recognized research program,” said Samir M. Parikh, M.D., Chair of Internal Medicine. “His contributions to our clinical, research, and educational missions have strengthened the Division and the Department, and I am deeply grateful for his partnership, counsel, and friendship.”
Sadia Ali, M.D., M.B.A., an Associate Professor of Internal Medicine and Clinical Chief of Endocrinology, will serve as Interim Chief of the Division. In addition to serving as Medical Director of the Endocrinology Subspecialty Clinic, Dr. Ali previously served as Service Chief for Endocrinology at Parkland and has played a key role in expanding access to endocrine care and advancing clinical initiatives across the health system. ■
Dr. Parikh holds the Donald W. Seldin Distinguished Chair in Internal Medicine and the Ruth W. and Milton P. Levy, Sr. Chair in Molecular Nephrology.
Kudos
Taylor Selected for Second Leadership Program
Trini Taylor, M.H.A., a Senior Division Operations Administrator with oversight of the Divisions of Allergy and Immunology, Cardiology, Digestive and Liver Diseases, Infectious Diseases & Geographic Medicine, Vascular Medicine, and the Center for Hypothalamic Research, has been selected for the Korn Ferry Leadership U for Humanity Cohort, a six-month leadership development program that includes executive coaching, virtual learning sessions, and career development opportunities. She was nominated by the National Association of Health Services Executives (NAHSE).
The program is intended for high-potential professionals and includes a competitive application process. Participants are nominated by partner organizations such as NAHSE and engage in a structured curriculum focused on leadership, communication, team development, and change management.
The scholarship is Taylor's second leadership-focused award of 2026 and reflects her continued commitment to professional development and lifelong learning. ■
Research Report
Letter Raises Concerns About Impact of Immigration Policy on Physician Workforce
A new research letter published in JAMAunderscores the essential role immigrant physicians play in the U.S. internal medicine workforce and raises concerns about how changes in immigration policy could affect physician availability and patient access to care. The study was co-authored by Salahuddin “Dino” Kazi, M.D., Professor in the Division of Rheumatic Diseases, Vice Chair of Education, and Director of the Internal Medicine Residency Program, along with colleagues from the American Board of Internal Medicine and UC San Francisco.
Analyzing data from nearly 250,000 board-certified internal medicine physicians, the authors found that almost half of actively practicing internists certified since 1990 were born outside the United States. More than one-third were both foreign-born and international medical graduates (IMGs). Dependence on immigrant physicians was even more pronounced in several subspecialties, with foreign-born IMGs accounting for more than half of physicians in nephrology, geriatrics, and sleep medicine.
The study also found that internal medicine relies on non-U.S. citizen IMGs more heavily than many other specialties. In the 2026 Main Residency Match, non-U.S. citizen IMGs filled nearly one-third of first-year internal medicine residency positions, a substantially higher proportion than in pediatrics, family medicine, psychiatry, surgery, or emergency medicine, according to the authors.
“The study highlights how deeply U.S. internal medicine depends on immigrant physicians and how changes in immigration policy could affect the physician workforce and access to care,” Dr. Kazi said.
Unlike studies that rely on practice location, this research used Medicare claims data to identify the physicians who actually cared for patients. The analysis found that patients from underserved communities make up a larger share of the patient panels of foreign-born IMGs than of other physician groups. Compared with U.S.-born physicians trained in the United States, foreign-born IMGs cared for higher proportions of Black, Latino, low-income, and dually eligible Medicare-Medicaid beneficiaries, as well as patients living in medically underserved areas.
“By examining claims data, we were able to better understand who these physicians are caring for,” Dr. Kazi said. “The findings show that immigrant physicians disproportionately serve patients from underserved communities, suggesting that disruptions to this workforce could have the greatest impact on populations that already face barriers to accessing care.”
The authors concluded that recent immigration policy changes could have significant implications for internal medicine subspecialties that rely heavily on immigrant physicians and could further exacerbate disparities in access to care among underserved populations. ■
Study Reveals How the Immune System Responds to Tuberculosis
A new study led by Beatriz Dias, Ph.D., an Instructor in the Division of Infectious Diseases and Geographic Medicine, has identified a protein that helps the immune system recognize and respond to tuberculosis (TB), one of the world’s leading infectious disease killers.
For the study, published in The Journal of Immunology, Dr. Dias and colleagues in the Michael Shiloh lab, examined a protein called sorting nexin 5 (SNX5), which helps move materials within cells. While SNX5 was already known to play a role in antiviral defenses, its role in fighting bacterial infections such as TB was not well understood. The researchers found that SNX5 serves as a previously unrecognized regulator of a key immune process known as MHC class II antigen presentation, which helps coordinate the body's response to infection.
“The findings show that SNX5 is a previously unrecognized regulator of MHC class II antigen presentation during Mycobacterium tuberculosis infection,” said Dr. Dias. “By linking the cell's protein-sorting component to antigen presentation and inflammation, this work provides new insight into how the immune system responds to tuberculosis.”
Using mouse models and laboratory experiments, the researchers found that animals lacking SNX5 became sicker and died sooner after TB infection than mice with normal levels of the protein. Surprisingly, both groups carried similar amounts of tuberculosis bacteria, suggesting that the difference was not the body's ability to control the infection itself but rather how the immune system responded to it. Mice lacking SNX5 developed greater inflammation in their lungs, which can contribute to tissue damage and worsen disease outcomes.
“What was particularly striking is that the mice lacking SNX5 carried the same bacterial burden as control animals but experienced greater mortality and lung inflammation,” Dr. Dias said. “This suggests the defect lies not in controlling the pathogen itself, but in the body’s ability to tolerate infection and limit tissue damage.”
The team discovered that SNX5 plays an important role in a process called antigen presentation. This process allows immune cells to display pieces of bacteria on their surface, helping other immune cells recognize a threat and mount a response. When SNX5 was absent, immune cells were less effective at presenting tuberculosis antigens and activating infection-fighting CD4-positive T cells.
Further experiments showed that SNX5 helps load protein fragments onto molecules known as MHC class II, which are essential for alerting the immune system to infection. Without SNX5, this process was impaired, leading to weaker communication between immune cells.
The findings uncovered a previously unknown role for SNX5 in antibacterial immunity and provide new insight into how the immune system responds to tuberculosis. According to the researchers, a better understanding of these pathways could help identify new approaches for reducing harmful inflammation and improving immune responses during TB infection.
“A better understanding of these pathways may ultimately help identify new approaches to reduce harmful inflammation while preserving protective immune responses during infection,” said Michael Shiloh, M.D., Ph.D., Professor of Internal Medicine and the study’s senior author. He also noted that the project was inspired in part by his collaboration with the late Beth Levine, M.D., whose pioneering work in autophagy, membrane trafficking, and host defense helped shape the study’s scientific direction.
Other contributors from the Shiloh lab included Kubra Naqvi, Ph.D., postdoctoral fellow; Victoria Ektnitphong, M.S., Research Associate; Samuel Alvarez-Arguedas, Ph.D., Instructor; Kathryn Rahlwes, Ph.D., former postdoctoral fellow; and Priscila Campos, Ph.D., Instructor.■
Dr. Shiloh holds the James P. Luby Professorship in Infectious Diseases.
Education & Training
Department to Celebrate GME Professionals on Aug. 21
The Department will recognize its 28 graduate medical education (GME) program coordinators and educational administrators on Aug. 21 as part of GME Professionals Day, a national observance honoring the individuals who help support residency and fellowship training programs.
Working across the Department’s residency and fellowship programs, GME professionals oversee accreditation activities, coordinate educational experiences, support trainees and faculty, and manage the day-to-day operations that keep training programs running effectively.
“Our GME coordinators and educational support team contribute to a strong record of educational excellence at UT Southwestern,” said Marc Valerin, Ph.D., M.B.A., M.A.D.R., Manager of Educational and Alumni Affairs. “Their efforts help ensure compliance with Accreditation Council for Graduate Medical Education (ACGME) requirements while fostering an environment in which residents and fellows can succeed.”
The institution and its ACGME-accredited training programs maintain Continuing Accreditation status, with many programs receiving commendations for meeting institutional, common, and specialty requirements. Additionally, several members of the GME team have earned Training Administrators of Graduate Medical Education (TAGME) certification, including Lilibeth Goode, who achieved certification earlier this year.
Observed annually on the third Friday in August, GME Professionals Day recognizes the administrators, coordinators, designated institutional officials, and others who support physician training programs nationwide. Department leaders encourage faculty, residents, fellows, and staff to take a moment to thank the GME professionals whose expertise and dedication help shape the next generation of physicians. ■
In Case You Missed It
Singal Contributes to New Consensus Framework on Liver Cancer Care
A multidisciplinary group of liver cancer experts, co-led by Amit Singal, M.D., M.S., a Professor in the Division of Digestive and Liver Diseases, Chief of Hepatology and Director of the Liver Tumor Program, has developed a new framework to help physicians choose the most appropriate treatment for hepatocellular carcinoma (HCC), the most common type of liver cancer. Published in Hepatology, the framework was created to reflect the growing number of treatment options now available and the way liver cancer is treated in today’s clinical practice.
“Treating liver cancer has become increasingly complex as new therapies have emerged in recent years,” said Dr. Singal, who also serves as Interim Chief of the Division of Digestive and Liver Diseases and Director of the William and Liza Lee Center for Liver Disease and Transplant Research. “Existing treatment guidelines do not always account for differences in tumor behavior, disease severity, or newer treatment approaches.”
To address those gaps, 20 experts from across North America worked together to develop a consensus-based system that combines the best available evidence with real-world clinical experience.
Known as BEACON-HCC, the framework helps physicians match patients with treatments based on factors such as the size and number of tumors, whether the cancer has spread into blood vessels or beyond the liver, and the patient's liver function. It also incorporates newer treatment options, including advanced radiation therapies and combinations of local and systemic treatments, which are playing a growing role in liver cancer care.
One of the study’s most important findings was that the recommendations generated by BEACON-HCC closely matched the treatment decisions made by independent liver cancer specialists. In a test involving 29 real-world patient cases, the framework agreed with expert recommendations nearly 97% of the time, compared with about 72% for a commonly used international treatment system.
“We already follow this framework in our Liver Tumor Program,” Dr. Singal said. “It provides a more flexible and personalized approach to treatment planning by considering both the biological characteristics of a patient’s cancer and the range of therapies available today.”
Additional studies are planned to further validate the framework in clinical practice. ■
Dr. Singal is a Dedman Family Scholar in Clinical Care and holds the Willis C. Maddrey, M.D. Distinguished Chair in Liver Disease.