Lab Members

Ali Rezaie, MD, MSc, FRCP(C)

Medical Director, GI Motility

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Ali Rezaie, MD, MSc, FRCP(C), is board certified in Gastroenterology and Internal Medicine by Royal College of Physicians and Surgeons of Canada and American Board of Internal Medicine. He earned his medical degree from the Shahid Behesti University of Medical Sciences in Tehran, Iran. Further he obtained a master's of science degree in epidemiology and administrative data analysis at the University of Calgary, Canada. His primary research interests involve irritable bowel syndrome, motility disorders of patients with inflammatory bowel disease and population-based data analysis.

Nipaporn Pichetshote, MD

Assistant Medical Director, GI Motility

Stacy Weitsman, MS

Research Associate, Program Coordinator Email:

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Stacy Weitsman, MS, is currently the coordinator for GI Motility Program. With more than 10 years experience in research and 50 co-authored peer reviewed journal articles and abstracts, she oversees both the clinical and basic science sections of the program. She earned her bachelor's of science degree in biochemistry from Indiana University and a master's degree in biochemistry from the University of California, Riverside. Prior to joining the Pimentel Laboratory, Weitsman was the coordinator for the Clinical Translational Science Institute (Cedars-Sinai/Harbor-UCLA), the research team leader in obstetrics and gynecology at Cedars-Sinai and the lead technician for the Department of Hematology and Oncology at UCLA.

Gillian Barlow, PhD

Project Scientist Email:

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Gillian Barlow, PhD, is a project scientist for the Medically Associated Science and Technology Program at Cedars-Sinai. She obtained her bachelor of science from Dublin City University in Ireland, where she majored in genetics and immunology, and subsequently earned her doctorate in molecular biology from University College Dublin. Her fields of expertise include molecular biology and molecular genetics, and she is highly experienced in cell culture and the generation and analysis of knockout and transgenic mouse models. Barlow's research interests include the roles of the gut microbiome in metabolism and weight gain, and in gastrointestinal conditions such as irritable bowel syndrome. Prior to joining the GI Motility Program, she was a research scientist at the Division of Molecular Neurogenetics in the Cedars-Sinai Department of Pediatrics. There she worked on the molecular genetics of Down syndrome, and later worked at the Division of Reproductive Endocrinology and Infertility in the Department of Obstetrics and Gynecology, where she worked on female infertility and premature ovarian failure. Barlow has held grants from the American Heart Association and has been a co-investigator on grants from the Eunice Kennedy Shriver National Institute of Child Health and Human Development. She has co-authored more than 30 peer-reviewed papers and five book chapters.

Benjamin Basseri, MD

Clinical Researcher Email:

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Benjamin Basseri, MD, is board certified by the American Board of Internal Medicine in Internal Medicine and Gastroenterology and Hepatology. He grew up in Santa Monica and received his undergraduate and medical education from UCLA. He completed his Internal Medicine residency at Cedars-Sinai, and completed his education with a fellowship in Gastroenterology and Hepatology at UCLA. Basseri has received special training to focus on GI motility disorders. He expands his medical education by attending seminars, including Digestive Disease Week, the American College of Gastroenterology Annual Meeting, as well as the Neurogastroenterology and Motility Scientific Meeting. He applies this knowledge and treats his patients using a variety of techniques. He is widely published and has received numerous awards. Basseri currently practices at Cedars-Sinai. His research and clinical interests include small intestinal bacterial overgrowth in IBS, GERD, esophageal diseases, and fecal microbiota transplant.

Walter Morales

Research Associate, Project Manager Email:

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Walter Morales earned his bachelor's degree from the UCLA. He has more than five years of experience in conducting both clinical and basic science research. Currently, he is the project manager for the Pimentel Laboratory.

Kathleen Shari Chua

Research Associate, Clinical Coordinator Email:

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Kathleen Shari Chua earned her bachelor's degree from Florida Atlantic University. She has more than five years of experience in coordinating clinical research studies that are investigator initiated as well as multi-centered clinical trials. In addition to working with the GI motility team, she also works closely with many of the team's collaborators.

Emily Rooks

Research Associate Email:

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Emily Rooks earned her BA in psychology from Touro College Los Angeles in 2011. She then joined the University of New England for pre-medical study. Rooks began at Cedars-Sinai as a volunteer working in the Pimentel Laboratory with the research team on a Campylobacter jejuni rat model for post-infectious IBS. Her current focus aims toward understanding the role of the Cdt-B toxin in post-infectious IBS and the subsequent pathophysiological effect on the gut, specifically Vinculin expression and localization.

Zachary Marsh

Research Associate Email:

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Zachary Marsh earned his bachelor's degree in psychobiology from the UCLA. From 2004–present, he works as an ADHD coach and mentor, guiding individuals suffering from the behavioral manifestations and life skill deficits hindering those with this disorder. He volunteered at Children's Hospital of Los Angeles from 2010–2012 assisting child development specialists and facilitating "play therapy" with ill children. He has been a research assistant at Cedars-Sinai in the Pimentel Laboratory since 2012 studying pro-inflammatory mediator expression in rat IBS models. His current focus centers on microbial gut population alterations in post-infectious IBS.

Eric Shah, MD

Resident Email:

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Eric Shah, MD, began working with the GI Motility Program as a medical student at Texas Tech University and has since participated in several research projects. He is currently an internal medicine resident at Cedars-Sinai.

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Prathyusha Dasari

Student Research Intern Email:

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SungChul Park

Visiting Scientist Email: