Faculty

Professor and Chair
Pulmonary and Critical Care Medicine
Dr. Schuller is chair of the Department of Internal Medicine – Transmountain.
He obtained his medical degree from the National Autonomous University of Mexico and went on to complete an internal medicine residency at Sinai Hospital in Detroit, Michigan and a fellowship in pulmonary and critical care medicine at Washington University in St. Louis, Missouri. Dr. Schuller subsequently served on the faculty of Washington University for 14 years, where he held roles as director of the pulmonary consult service at Barnes-Jewish Hospital and director of the pulmonary and critical care fellowship program. He was also the chief of the pulmonary and critical care division and medical director of the intensive care unit at Creighton University Medical Center in Omaha, Nebraska from 2002 until 2012, where he developed a multidisciplinary academic intensivist program with the highest standards for clinical care, medical education and research. Before joining TTUHSC El Paso, Dr. Schuller served as chief of medical critical care and director of a newly developed pulmonary critical care fellowship program at Baylor University Medical Center in Dallas, Texas.

Assistant Professor
Nephrology
Olufemi Aduroja, M.D., M.P.H., is an assistant professor in the Department of Internal Medicine – Transmountain.
Dr. Aduroja is a medical graduate of the College of Medicine of the University of Lagos in Nigeria. He earned an M.P.H. degree from the University of Alabama at Birmingham before pursuing his residency in internal medicine at the Cleveland Clinic. He went to Detroit Medical Center for a fellowship in nephrology, which he completed at the Virginia Commonwealth University. He practices at Texas Tech Physicians of El Paso at Transmountain.
Dr. Aduroja is board certified in nephrology by the American Board of Internal Medicine. He is also a certified hypertension specialist.

Assistant Professor
Gastroenterology
Paul Estrada, M.D., is an assistant professor in the Department of Gastroenterology – Transmountain.
Dr. Estrada was born and grew up in San Antonio, TX. He attended undergraduate at Duke University and went on to complete medical school at Baylor College of Medicine. He then completed residency in Internal Medicine and Fellowship in Gastroenterology at the University of Wisconsin Hospitals and Clinics in Madison, WI, and completed a year of advanced endoscopy training in ERCP and EUS at the same institution.

Assistant Professor
Geriatric Medicine
Dr. Maanit Kohli is an Assistant Professor in the Department of Internal Medicine at Texas Tech University Health Sciences Center El Paso.
Dr. Maanit Kohli is an Assistant Professor in the Department of Internal Medicine at Texas Tech University Health Sciences Center El Paso. He is board-certified in Internal Medicine and Geriatric Medicine. Dr. Kohli's prior faculty appointments include Attending Physician at Drexel University Medical College in Philadelphia and the Icahn School of Medicine at Mount Sinai.
Dr. Kohli completed his medical school from SSR medical College in 2011. He then completed his Internal Medicine residency at Saint Peter's University Hospital in 2018. Notably, in 2018, Dr. Kohli was named Chief Resident during his final year of residency. After that, Dr. Kohli completed the prestigious Geriatric Medicine fellowship with the Brookdale Department of Geriatrics and Palliative Medicine at Icahn School of Medicine at Mount Sinai, NY.
Dr. Kohli takes a keen interest in Medical Education, actively participating in multiple didactic and clinical teaching activities. In addition, he is a recipient of various accolades for his efforts to promote bedside medicine and his volunteer work.
Dr. Kohli is an Associate Member of the Royal College of Physicians of Edinburgh and a member of the American Geriatrics Society, American College of Physicians, and the Society of Bedside Medicine.

Assistant Professor
Pulmonary and Critical Care Medicine
Maria Theresa De Gracia Opina, M.D., is an assistant professor in the Department of Internal Medicine – Transmountain.
Dr. Maria Theresa De Gracia Opina completed residency training in Internal Medicine prior to attending Wake Forest School of Medicine where she completed fellowship in Pulmonary Disease and Critical Care Medicine followed by additional advanced research training through a National Institutes of Health T32-supported post-doctoral research fellowship in Gerontological and Geriatric Research. Her research interests include understanding pulmonary physiology, disease, and the aging lung with a focus in the older adult population. She enjoys teaching. She is also passionate about educating patients and their families and believes that all patients should be a part of the decision-making process in the management of their complex pulmonary disease.

Assistant Professor
Pulmonary and Critical Care Medicine
Bharat Ved Prakash, M.D., is an assistant professor in the Department of Internal Medicine – Transmountain.
He completed his residency in internal medicine at the University of Pittsburgh Medical Center, followed by a fellowship in pulmonary and critical care with a specialization in interventional pulmonary medicine at Wake Forest Baptist Medical Center in Winston-Salem, North Carolina. He brings three years of experience as a practicing pulmonary internationalist and critical care physician to the department. Dr. Prakash is board-certified in internal medicine and pulmonary critical care medicine and serves as the medical director of the intensive care unit at The Hospitals of Providence Transmountain Campus.

Assistant Professor
Oncology/Hematology
Roberto Prieto, M.D., is an assistant professor in the Department of Internal Medicine – Transmountain.
Dr. Prieto earned his medical degree at the Uniformed Services University of the Health Sciences. He completed his residency at Keesler AFB Medical Center and a fellowship at Wilford Hall Medicl Center.
Dr. Prieto is board certified in internal medicine, oncology and hematology.
His clinical expertise includes:
- Lung and head/neck cancer
- Myeloproliferative neoplasia/disorders and lymphoma
- Colon cancer and caners of the upper digestive tract (esophagus, stomach, biliary tree and pancreas)
- Breast cancer, kidney cancer, melanoma
- Thrombophilia (hypercoagulable conditions) and thrombosis of malignancy
- Anemia and disorders of WBCs; thrombocytopenia (DIC, TTP, ITP)

Assistant Professor
General Medicine
Gowri Renganathan, M.D., is an instructor in the Department of General Medicine – Transmountain.
Dr. Renganathan received her medical degree from Stanley Medical College,practice primary care for a few years and went on to pursue Internal Medicine residency training at University of California Los Angeles - Kern Medical. The residency program acknowledged her exemplary service of her patients and honored her with the prestigious "Robert S. Mosser award" for excellence in Internal Medicine. She is passionate about practicing preventive medicine and providing high quality primary care. She enjoys cooking and going on long road trips with family.

Assistant Professor
General Medicine
Lela Ruck, M.D., is an assistant professor in the Department of General Medicine – Transmountain.
Dr. Ruck was born and raised in El Paso. I went to medical school at Texas Tech University Health Sciences Center in Lubbock, TX. I then pursued internal medicine residency at Washington University in St. Louis, MO and subsequently stayed on as faculty in the division of Hospital Medicine where I was a clinical hospitalist for two years before changing tracts to become an academic hospitalist. As an academic hospitalist, I found a passion for teaching residents and medical students. I'm now excited to return home to care for my community. My interests are in caring for the hospitalized patient and helping patients transition from inpatient to outpatient care. I also look forward to continuing to teach new generations of doctors.

Assistant Professor
General Medicine
Program Director - Internal Medicine Residency
Sudhagar Thangarasu, M.D., FACP, is an assistant professor in the Department of Internal Medicine – Transmountain.
Dr. Thangarasu obtained his medical degree from Stanley Medical College at the Tamilnadu Dr.M.G.R Medical University in Chennai, India and went on to get internal medicine residency training at the University of Pittsburgh Medical Center in Pennsylvania.
Crafting an academic career track toward becoming a leading teacher in medicine, Dr. Thangarasu served as an academic hospitalist at the University of Cincinnati Medical Center, where he took a leadership role as medical director of the comprehensive care unit. When he moved to Bakersfield, California, he spearheaded the ambulatory medicine clinics at Kern Medical toward several accomplishments. He then started the new academic hospitalist division and served as division chief, expanding the services. He was a core faculty and associate program director for the internal medicine residency program affiliated with the David Geffen School of Medicine at the University of California-Los Angeles.
Dr. Thangarasu joined TTUHSC El Paso in 2019 as the founding program director of the internal medicine residency at the Transmountain campus of The Hospitals of Providence. He is passionate about delivering high quality care in hospital medicine and designing an innovative residency training curriculum to train the internists of the future. He loves kayaking, hiking and going on long road trips with his family.
Dr. Thangarasu is board certified in internal medicine.

Nurse Practitioner
Cardiology
Lizbeth Castro earned her Bachelor of Science in nursing from the University of Texas at El Paso, followed by her Master's of Science in Nursing from Texas Tech University.
She is a board-certified Adult-Gerontology Acute Care Nurse Practitioner with a specialty in cardiology. She is also fluent in Spanish.

Nurse Practitioner
Internal Medicine
Mohamed Khamsi earned his Bachelor of Science in Nursing from the University of Texas at El Paso, followed by his Master of Science in Nursing from The University of Texas Health Science Center at San Antonio.
He is a board-certified Adult-Gerontology Acute Care Nurse Practitioner.

Nurse Practitioner
Internal Medicine
Erika Meza earned her Bachelor of Science in Nursing from New Mexico State University, followed by her Master of Science in Nursing from the University of Texas at El Paso.
She is a board-certified Adult-Gerontology Acute Care Nurse Practitioner. She is fluent in Spanish.

Nurse Practitioner
Internal Medicine
Itzel Rivera earned her Bachelor of Science and Master of Science in nursing from the University of Texas at El Paso.
She is a board-certified Adult-Gerontology Acute Care Nurse Practitioner. She is fluent in Spanish.