School of Medicine
Showing 81-100 of 149 Results
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Adel Mutahar
Postdoctoral Scholar, General and Vascular Surgery
BioDr. Adel Z. I. Mutahar is a postdoctoral researcher in the Department of Surgery at Stanford University, working under the mentorship of Dr. Frederick M. Dirbas. His research focuses on translational breast cancer biology and emerging radiotherapy technologies, with an emphasis on tumor–microenvironment interactions, immuno-oncology, and preclinical therapeutic development. His academic journey spans three countries—beginning in Yemen, advancing through India, and now progressing at Stanford—reflecting his commitment to impactful cancer research and global scientific advancement.
Dr. Mutahar began his career in Yemen, earning his Bachelor’s degree in Medical Laboratory Sciences before joining Abs Community College as a faculty member. From 2007–2013, he held several academic leadership roles, including Academic Director, Head of Evaluation, and Assistant Dean of Students, where he modernized curriculum, expanded hands-on diagnostic training, and strengthened laboratory education infrastructure in resource-limited settings. His work contributed to building a more skilled medical diagnostics workforce and improving pathways for laboratory science education.
Awarded a prestigious national merit scholarship, Dr. Mutahar continued his graduate and doctoral training in India, completing his M.S. and Ph.D. in Biotechnology with a focus on triple-negative breast cancer. During his doctoral work, he developed 3D tumor spheroid models and combinatorial therapeutic strategies, demonstrating synergy between anti-angiogenic agents and chemotherapy in TNBC. He further advanced this research by creating an orthotopic murine model to investigate metastatic progression and demonstrated that knockdown of the MTA1 gene in mesenchymal stem cells (MSCs) significantly suppressed TNBC invasion, angiogenesis, and metastatic spread, introducing a promising stromal-targeted therapeutic concept for aggressive breast cancer. This work earned recognition through travel grants, conference presentations, and a Best Poster Award. His scientific adaptability was further demonstrated during the COVID-19 pandemic, when he uncovered a novel interaction between SARS-CoV-2 Spike RBD and VEGF signaling.
At Stanford, his work emphases on FLASH radiotherapy, an ultrahigh-dose-rate modality with the potential to widen the therapeutic window by minimizing normal-tissue toxicity while maintaining tumor control. Working within Dr. Dirbas’s translational breast oncology program, Dr. Mutahar employs patient-derived xenografts, orthotopic murine models, spatial transcriptomics, single-cell RNA sequencing, and immune profiling to dissect the biological mechanisms governing treatment response. His research integrates multi-omics analysis to map early and late radiotherapy injury pathways—including senescence, apoptosis and fibrosis. His goal is to develop mechanism-driven radio-immunotherapy strategies and durable FLASH-RT combination regimens that can be translated into clinical trials for breast cancer, improving therapeutic durability, minimizing toxicity, and ultimately enhancing patient outcomes.
Dr. Mutahar’s long-term vision is to establish an independent laboratory at the intersection of radiobiology, immuno-oncology, and translational therapeutics. Guided by Dr. Dirbas’s mentorship and shaped by multidisciplinary experience across three continents, he aims to develop biologically informed treatment strategies that eradicate tumors while preserving normal tissue and immune integrity—ultimately improving quality of life and survival for women with aggressive breast cancers. -
Aussama Nassar, MD, MSc,FACS, FRCSC
Clinical Associate Professor, Surgery - General Surgery
BioDr. Nassar is board-certified in both General Surgery and Surgical Critical Care in the United States and Canada, underscoring his exceptional expertise in these fields. He holds a Master of Science in Health Science Education from McMaster University, Canada, further solidifying his strong academic foundation.
Currently, Dr. Nassar serves as the inaugural Director of the Emergency General Surgery Service and the Director of the Surgical Critical Care Fellowship Program at Stanford University. He is also the founder and director of the Surgery Resident Coaching Program. With over 12 years of clinical and academic experience at premier tertiary care referral centers across North America, Dr. Nassar brings unparalleled knowledge and leadership to his roles.
Dr. Nassar's clinical interests include trauma, acute care surgery, critical care, and a particular focus on abdominal wall reconstruction. As a dedicated clinician-educator, he is a certified simulation educator and serves as a course director for ATLS and ASSET programs. His research is centered on advancing surgical education, with an emphasis on fostering the development of non-technical skills in surgical training.
In addition to his educational initiatives, Dr. Nassar is actively engaged in developing innovative assessment tools for surgical trainees and addressing burnout among physicians and healthcare professionals. With a strong national and international presence, Dr. Nassar continues to shape the future of surgical education and healthcare delivery through his leadership, research, and advocacy. -
Kenneth Nieser
Postdoctoral Scholar, General Surgery
BioKen Nieser is a postdoctoral research fellow through the Big Data-Scientist Training Enhancement Program (BD-STEP) at the Palo Alto VA and in the Department of Surgery, Stanford School of Medicine. Ken received a BA in Physics and Mathematics from Swarthmore College and a PhD in Epidemiology with a minor in Statistics from the University of Wisconsin-Madison. During his PhD, Ken developed and applied statistical methods for improving algorithmic fairness of data analyses used to inform screening and treatment of mental illnesses. These projects included development of an approach for detecting sample subsets with differential psychological symptom patterns and a sample representation reweighting method for improving the precision of subgroup-specific treatment effect estimation.
Ken’s current research interests are in health care inequities, quality measurement, and algorithmic fairness. During his fellowship, Ken will be working on investigating the statistical reliability of quality measures and decomposing health care disparities to provide practical information for resolving inequities, with applications in mental health care and surgical care. -
Jeffrey Norton, MD
Robert L. and Mary Ellenburg Professor of Surgery, Emeritus
Current Research and Scholarly InterestsInterleukin-12 is a Th1 cytokine. It is important in the cell mediated immune response. We are investigating its role as an anti-tumor cytokine to augment the immune response against cancer. We are planning a human trial.
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Hang T Pham
Research Specialist, Surgery - General Surgery
Current Role at StanfordStanford School of Medicine: Senior Research Scientist
Stanford Prevention Policy Modeling Lab: Affiliated Member (https://ppml.stanford.edu/people/hang-pham) -
George A. Poultsides, MD, MS
Stanford Department of Surgery Professor
Current Research and Scholarly InterestsClinical trials of experimental diagnostics and therapeutics; outcomes analysis following combined modality treatment of hepatic, pancreatic, and gastrointestinal malignancies.
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Carla Pugh, MD, PhD
Thomas Krummel Professor
Current Research and Scholarly InterestsThe Technology Enabled Clinical Improvement (T.E.C.I.) Center is a multidisciplinary team of researchers dedicated to the design and implementation of advanced engineering technologies that facilitate data acquisition relating to clinical performance.
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Dan Riskin
Clinical Professor (Affiliated), Surgery - General Surgery
Staff, Surgery - General SurgeryBioDr. Riskin is a Clinical Professor of Surgery. His research interests include healthcare quality, technology, and policy. With a focus on translational research, developed products are in use by leading health systems and insurers influencing the care of millions of patients.
Dr. Riskin's medical credentials include a MD from Boston University, residency in surgery at UCLA, and fellowship in critical care and acute care surgery at Stanford University. He is board-certified in four specialties, including surgery, critical care, palliative care, and clinical informatics. His business training includes a MBA with a focus in bioinformatics from the Massachusetts Institute of Technology and the Stanford Biodesign Innovation Fellowship. -
Brian Ruhle, MD, MS
Clinical Assistant Professor, Surgery - General Surgery
BioDr. Ruhle is a board-certified surgeon with dual fellowship training in bariatric and minimally invasive surgery from Stanford Health Care and endocrine surgery from UCLA Health. He also serves as a clinical assistant professor in the Department of Surgery, Division of General Surgery at Stanford University School of Medicine.
Dr. Ruhle specializes in bariatric (weight loss) surgery, foregut (upper digestive tract) surgery, and abdominal wall reconstruction. He uses leading-edge laparoscopic and robotic surgical techniques to help patients achieve sustainable weight loss and improve obesity related health conditions. His expertise in advanced minimally invasive procedures offers patients significant benefits, including faster recoveries, reduced pain, and shorter hospital stays.
Dr. Ruhle’s research interests span a wide range of topics in metabolic and bariatric surgery. His studies have explored combination therapy for obesity management, improved screening and treatment of endocrine disorders, and optimizing outcomes in thyroid and parathyroid surgery. He has published his findings in numerous peer-reviewed journals, including Surgery, Journal of Gastrointestinal Surgery, Blood, and Journal of the American College of Surgeons.
During his surgical training, Dr. Ruhle presented at prominent national and regional meetings, including the annual meetings of the American Association of Endocrine Surgeons and American College of Surgeons Clinical Congress. His presentations have addressed innovative topics such as using GLP-1 agonists (medications that help regulate blood sugar and reduce appetite) before bariatric surgery. His presentations have also addressed improving screening protocols for hyperaldosteronism (high blood pressure caused by the excess production of the hormone aldosterone).
Dr. Ruhle is a member of the American Association of Endocrine Surgeons, American Society for Metabolic and Bariatric Surgery, Clinical Association of California Endocrinologists, and Society of American Gastrointestinal and Endoscopic Surgeons. -
Alejandra Ruiz
Postdoctoral Scholar, General Surgery
BioDr. Alejandra Ruiz is a physician scientist with experience in high-complexity medical settings, including oncology and intensive care. She is a strong advocate for integrative care, addressing both physical and mental health needs. Currently, Dr. Ruiz is a postdoctoral researcher in both the Department of of Emergency Medicine and the Department of Surgery, where she investigates the barriers faced by underserved communities when seeking health care while developing strategies to improve access and connection to health services. Deeply committed to community based participatory research and health advocacy, Dr. Ruiz is dedicated to creating sustainable pathways for underserved populations to receive comprehensive care.
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Yann Sakref
Postdoctoral Scholar, General Surgery
BioYann Sakref is a Postdoctoral Scholar in General Surgery at Stanford University, working within the Knowlton Lab. With a passion for interdisciplinary sciences and advancing medical biotechnology and patient care, Yann is developing clinical and AI solutions as part of an ARPA-H-funded project under Dr. Knowlton's supervision. His work focuses on creating computer vision models for surgical assistance and contributing to the collaborative development of innovative tools by working closely with clinical, engineering, and AI teams. He also works closely with collaborators at the S-SPIRE Center.
