Physician Assistant Faculty and Staff

Rasha Abdrabou received her Master’s in Public Health in 2002 and her Doctorate in Public Health in 2009, both from Loma Linda University.  She has since taught in undergraduate and graduate programs at various universities, including Cal Baptist University, Cal State Dominguez and West Coast University. She has also worked in the field of community nutrition for various public health programs such as Healthy Smiles, Early Head Start and Champions for Change.  She returned to Loma Linda University in 2018 as full-time faculty for the Physician Assistant Department, and assumed the position of Department Chair in 2023.  Dr. Abdrabou is also Director of Education Assessment, a position that focuses on ensuring the delivery of quality education standards and the continuous improvement of the clinical and didactic curricula. Dr. Abdrabou’s research interests include applying public health practices in clinical settings and development, implementation and dissemination of interventions to combat chronic disease.  She is also interested in pedagogical research centered around practices of learning and teaching assessments.

Courtney Marquez received her Bachelor of Science degree in Kinesiology with a concentration in Clinical Exercise Science and Minor in Sociology from California State University, Fullerton in 2009. She obtained her Master's degree in Physician Assistant Sciences in 2014 from Loma Linda University and has worked in General Pediatrics since graduation.  She returned to Loma Linda University in 2015 as full-time faculty, where she has worked both didactically and clinically for the Physician Assistant Department.  Professor Marquez currently serves as the Program Director, where her duties include overseeing program accreditation as well as the didactic and clinical phases of the program.  She provides lectures in Preventive Medicine, Physical Diagnosis, Clinical Medicine, Pediatrics and PA Professional Issues. Additionally, she facilitates the Inter-Professional Education Workshop during the didactic phase of the program. She plans to pursue her doctorate degree in 2021.

Wessam Labib graduated from the University of Illinois, Chicago, Family Medicine Residency program in 2008. Simultaneously, he received a Master’s of Public Health in Health Policy and Administration that same year.  In 2009, he completed a Geriatric Medicine Fellowship at UCLA and a Medical Student Education Fellowship from the Society of Teachers of Family Medicine in 2012. Currently, he practices Family/Geriatric Medicine at the Loma Linda University Family Medical Group. He is also Director of the Adult Specialty Clinic (ASC) - Memory clinic.  He is an Assistant Professor for the Department of Family Medicine, School of Medicine and School of Nursing. He is also the Geriatric Medicine Rotations Director – Family Medicine Residency.  He is the Director of Medical Student Education – Department of Family Medicine and was appointed the PA program Medical Director in 2016.  He is passionate about education and believes strongly in the value of the multidisciplinary approach to education and to healthcare.

Catherine Oms was raised locally and graduated from Loma Linda Academy in 1997. She received an Associate's Degree in Nursing from Southwestern Adventist University in 1999. She obtained her Bachelor's Degree in Kinesiology from Cal State University, San Bernardino in 2003, both Master's Degree in Physician Assistant Sciences in 2007 and Doctoral degree in Public Health with an emphasis in Preventive care in 2020 from Loma Linda University. Since that time, she has worked in pediatrics, women's health, family practice and prevention/wellness specialties. She completed the OB/GYN Residency Program for PA's from Arrowhead Medical Center in 2009. She returned to Loma Linda University in 2011 as full-time faculty and since then has served the program as Didactic Coordinator, Associate Program Director and Department Chair. Currently, her responsibilities include assisting the didactic team program needs, implementing the mission and vision of the institution and participate in teaching and research possibilities.

Heather Cabrera received her Bachelor of Science degree in Biology with a concentration in Cellular and Developmental Biology from California State University, Fullerton. Immediately following graduation from CSU Fullerton, she was invited to join the part time faculty as an instructor for the Biology department’s Anatomy Lab. She later obtained her Master’s degree in Physician Assistant Sciences in 2017 from Loma Linda University and has worked as a PA in both the Emergency and Primary Care settings since graduation. Her passion for education led her back to Loma Linda University in 2022 where she is now full-time faculty for the Physician Assistant program. As a Didactic Coordinator, her responsibilities focus on coordinating and teaching Pathophysiology throughout the didactic phase as well as advising the current PA students in their clinical and didactic years. She has plans to pursue her Doctoral degree in the future.

Rokaya Hijaz received her bachelor’s degree in Molecular and Cellular Biology from the University of California, Berkeley in 2014. Following graduation, she served as an educator at Chaffey College’s Success Center where she provided support to students in chemistry and biology courses. In 2020, She obtained her master’s degree in Physician Assistant Studies from Western University of Health Sciences. Since that time, she has worked primarily in acute care settings including emergency medicine and urgent care. Her passion for education led her to join the Loma Linda Physician Assistant program in 2023 as a full-time assistant professor. Her responsibilities include teaching Clinical Medicine to students in the didactic year and advising students in the clinical year.

Nicholas Walther received his Bachelor of Science degree in Kinesiology from California State University, Northridge in 2011. He obtained his Master’s degree in Physician Assistant Sciences in 2015 from Loma Linda University and has worked in Emergency and Family Medicine and currently works in the Urgent Care. He returned to Loma Linda in 2023 as a full-time Didactic Coordinator for the Physician Assistant program. His responsibilities include teaching Diagnostic Techniques throughout the didactic year.

Tunde Hrotko was born and raised in Southern California, where she earned her bachelor’s degree in Food and Nutrition Sciences from Cal Poly Pomona in 2001.  She then completed her dietetic internship program at LAC + USC Medical Center and became a Registered Dietitian in 2002.  She worked as a Clinical Registered Dietitian and Director of Food and Nutrition Services for a total of  9 years until deciding to become a Physician Assistant.  She received her Master’s degree in Physician Assistant Sciences from Loma Linda University in 2013.  Since that time, she has worked in private practice Gastroenterology and Neurosurgery at Loma Linda Medical Center.  She joined the Loma Linda Physician Assistant program in 2022 as a full-time faculty Clinical Coordinator and continues to work in Gastroenterology as well.  Her duties include coordinating and evaluating students in clinical rotations and clinical site development and retention.

Gary Walker graduated from the University of California, San Diego with a Bachelor of Science degree in Physiology and Neuroscience in 1995.  He completed his Physician Assistant studies from the George Washington University in Washington DC with a Master of Health Science degree in 1997.  He has worked in Family Medicine, Emergency Medicine and Surgery, specifically in a surgical subspeciality of Urology.  He then began working at Loma Linda University Physician Assistant Program as Adjunct Faculty teaching various topics in Clinical Medicine and Diagnostic Techniques.  In 2022, he was full-time at the University of La Verne Physician Assistant Program as Director of Didactic Education.  He then transferred to Loma Linda University PA program in 2024.  He is passionate about educating students to be the best Physician Assistants possible to bridge the gap in medicine that PA’s are equipped to fill.

Dr. Bethania Siviero received her Master of Science in Geology and her PhD in Biology (emphasis in Paleontology) in 2012 and 2019 respectively, from Loma Linda University (LLU).  Between 2019 to 2021, she advanced her training as a post-doctoral researcher in Molecular Paleontology with the Department of Biochemistry at LLU. During this time, she has instructed the Clinical Anatomy course for the Physician Assistant program at LLU (2017-present). Currently, Dr. Siviero is a full-time faculty member at LLU with the School of Medicine, Department of Pathology and Human Anatomy, and teaches Gross Anatomy (2021- present). She also has a secondary appointment with the Department of Earth and Biological Sciences at LLU. Her research is in Paleopathology, where she is currently examining different types of lesions found in fossil skeletal remains from a Cretaceous bonebed.

Lillian Luna earned her Associate of Business Administration degree in 2006 from San Joaquin Valley College and went on to receive a Bachelor of Science in Business Management from the University of Phoenix in 2011. She joined Loma Linda University’s Physician Assistant (PA) program in 2015, where she collaborates with all teams to drive program development, ensure continued progression, and enhance overall functionality. Her responsibilities encompass accreditation, managing grants, admissions, and alumni relations.  Prior to joining the University, Lillian built a strong foundation in both academic and admissions roles.

Alfonso Martin Jr. earned his Master’s in Education from the University of La Verne 2024, where he also completed his undergraduate studies in 2020. With a strong background in higher education, he has worked with various institutions. Alfonso has extensive experience in student services, academic resources, and program development. He has been actively involved in coordinating Physician Assistant student clinical rotations, ensuring the successful placement and training of students in healthcare settings. His expertise extends into faculty development, career services, and student success initiatives. In addition to his work in education, Alfonso has a background in surgical technology, holding Certified Surgical Technologist (CST) credentials, and has contributed to program oversight and accreditation efforts in healthcare-related academic programs. His leadership style is hands-on and student-centered, influenced by his military service in the U.S. Army, where he cultivated a strong work ethic, discipline, and a commitment to mentorship. Alfonso is a member of the National Honor Society for Educators and the National Society of Leadership and Success. His professional interests include stakeholder management, curriculum development, and fostering partnerships between academic institutions and industry leaders to enhance student career outcomes.

Christian Figueroa joined the PA Department January 2024. His wealth of experience has allowed him to seamlessly transition into our program. His primary responsibilities include providing administrative support to the faculty and staff, application service, and coordinating student recruitment and events. Christian consistently demonstrates a commitment to excellence in all aspects of his role as an Administrative Secretary.