The Medical Opinion Marketplace

Mathias A. Masem, MD, is an orthopaedic surgeon specializing in hand surgery and upper-extremity orthopaedic care, including elbow conditions and peripheral nerve disorders. With more than 20 years of experience performing surgery of the hand and upper extremities, he treats a wide range of problems affecting function, comfort, and performance for patients with traumatic injuries, overuse conditions, and complex reconstructive needs. Dr. Masem earned his medical degree at the University of Minnesota. He completed internship training in general surgery at UCSF Benioff Children’s Hospital Oakland and continued postgraduate training at UCSF, including general surgery training and an orthopaedic surgery residency. He pursued advanced subspecialty education with hand surgery fellowship training in Oakland and additional clinical and research fellowship training in hand and upper-extremity surgery and microsurgery at Massachusetts General Hospital and Harvard Medical School. He also spent two years in Switzerland as an orthopaedic research physician at the University of Bern and the Laboratory for Experimental Surgery. Board certified in orthopaedic surgery and surgery of the hand, Dr. Masem serves as Chief of Hand Surgery at Alta Bates Summit Medical Center. He is an Assistant Clinical Professor in the UCSF Department of Orthopaedic Surgery, contributes to fellowship training, and has authored publications and delivered lectures in upper-extremity surgery. He also consults on hand and upper-extremity injuries for University of California, Berkeley athletic teams.

Mathias A. Masem, MD, is a board-certified orthopaedic surgeon with advanced certification in surgery of the hand. He serves as an Assistant Clinical Professor in the UCSF Department of Orthopaedic Surgery and provides specialized care for conditions affecting the hand, elbow, and peripheral nerves, with an emphasis on upper-extremity function, reconstruction, and recovery. Dr. Masem earned his medical degree from the University of Minnesota and completed orthopaedic surgery residency training at UCSF Medical Center. He pursued additional fellowship training in hand surgery, including hand, upper-extremity, and microsurgery training associated with Massachusetts General Hospital and Harvard Medical School, as well as advanced hand surgery fellowship training in Oakland. His work also includes orthopaedic research experience in Switzerland, with appointments at the University of Bern and the Laboratory for Experimental Surgery in Davos. Dr. Masem has held key clinical leadership roles, including Chief of the Division of Hand Surgery and immediate past Chairman of the Department of Orthopedic Surgery at Alta Bates Summit Medical Center. He also serves as a consultant for hand and upper-extremity injuries for University of California, Berkeley athletic teams. His scholarly contributions include peer-reviewed publications in leading medical journals.

Michael E. Hebrard, MD, is a physician specializing in Pain Medicine within the field of Physical Medicine and Rehabilitation. He is board certified by the American Board of Physical Medicine and Rehabilitation. Dr. Hebrard focuses on the evaluation and non-surgical management of pain conditions, with an emphasis on restoring function and improving quality of life through individualized, rehabilitation-oriented care. His approach commonly includes careful diagnostic assessment and coordination with other clinicians and therapies, such as physical therapy and related medical specialties, to support comprehensive pain management. Dr. Hebrard completed his medical education at Creighton University School of Medicine and subsequently completed residency training at Stanford University Medical Center. He is affiliated with Alta Bates Summit Medical Center (Summit Campus). In addition to his clinical work, he has held leadership roles within a California-based medical organization in the physical medicine and rehabilitation space. Public listings indicate he speaks English and may also offer care in additional languages such as Spanish or Russian.

Timothy Shen, M.D., is a Physical Medicine & Rehabilitation physician who focuses on restoring function and improving quality of life for people dealing with pain and musculoskeletal conditions. He earned his medical degree from Tufts University School of Medicine and completed residency training in Physical Medicine & Rehabilitation at the University of Michigan. Dr. Shen is board certified in Physical Medicine & Rehabilitation and has been affiliated with Alta Bates Summit Medical Center (Summit Campus). Dr. Shen’s clinical interests include pain medicine and comprehensive rehabilitation care, with an emphasis on thoughtful evaluation and individualized treatment planning. His work is informed by both clinical experience and contributions to the medical literature, including co-authoring a peer-reviewed case report in the Archives of Physical Medicine and Rehabilitation. He is a member of the American Academy of Physical Medicine and Rehabilitation and is known for a patient-centered approach that integrates rehabilitation strategies, function-focused goals, and pain management options. Dr. Shen provides care in the East Bay and is also associated with practice in Sonoma, California. He offers care in English and Spanish.

Joseph B. Marzouk, MD, is an infectious disease physician based in Oakland, California, with a clinical focus that includes HIV medicine and complex infectious diseases. He earned his undergraduate degree from Princeton University and received his medical degree from Boston University School of Medicine. Dr. Marzouk completed internal medicine internship and residency training at Wayne State University–affiliated hospitals, including service as a chief medical resident, and went on to complete fellowship training in infectious diseases at the University of California, San Francisco. Board certified in Internal Medicine and Infectious Disease by the American Board of Internal Medicine, Dr. Marzouk also holds the HIV Specialist credential from the American Academy of HIV Medicine and certification in infection prevention through the Certification Board of Infection Control. He is a Fellow of the Infectious Diseases Society of America and a Fellow of the American College of Physicians. In addition to patient care, Dr. Marzouk has held leadership roles within hospital infectious disease services and has served as a medical director for infection prevention and control. He also provides infectious disease expert review and testimony services in medico-legal settings.

David Pingitore, PhD, ABPP, CBIS, is a clinical psychologist in Oakland, California. He has been associated with an incorporated clinical psychology practice in the Oakland area and has provided psychological services that include independent psychological evaluations and related forensic consultation. His board certification (ABPP) and CBIS credential reflect advanced professional training and experience in psychological practice. In addition to clinical work, Dr. Pingitore has been listed in professional contexts involving expert evaluation services, supporting legal, administrative, and disability-related decision-making when objective psychological assessment is required. Public payer listings have indicated participation with Medicare through acceptance of Medicare assignment. Dr. Pingitore previously held a California psychologist license; public records from the state licensing board report that his license was voluntarily surrendered and accepted by the board, and a separate state notice documents a provider suspension related to California workers’ compensation. Prospective patients and referral sources may wish to confirm current practice status and available services through standard verification channels.

Stephen E. Francis, PhD, is a California-licensed psychologist specializing in clinical neuropsychology. He is board-certified in clinical neuropsychology by the American Board of Professional Neuropsychology and is a fellow of the American College of Professional Neuropsychology. Dr. Francis provides comprehensive neuropsychological and psychological assessment services, with clinical experience evaluating and treating concerns related to traumatic brain injury, chronic pain, PTSD, anxiety, and stress-related disorders. Dr. Francis earned his PhD in Clinical Psychology from the California Institute of Integral Studies, following an MS in Psychology from the University of the Pacific and a BA in Psychology from the University of Oregon. He completed advanced postdoctoral training in neuropsychology, including a postdoctoral certificate from Fielding Graduate University and a postdoctoral fellowship at Laguna Honda Hospital in San Francisco. In addition to clinical practice, Dr. Francis offers forensic neuropsychology services, including independent medical examinations, expert witness consultation, and evaluations relevant to personal injury and workers’ compensation matters, such as fitness-for-duty and malingering-related assessments. His professional leadership experience includes serving as Chief of Neuropsychology at a rehabilitation hospital. He is an active member of major professional organizations in neuropsychology and psychology.

Mariam Hasan, M.D., is an internal medicine physician with a focus in hospital medicine. She provides comprehensive adult care, emphasizing evidence-based evaluation and management of complex medical conditions in the inpatient setting and supporting safe transitions of care. Dr. Hasan completed her medical education at Dow University of Health Sciences and pursued internal medicine residency training at Alameda County Medical Center in Oakland. She is board certified in Internal Medicine. Dr. Hasan is recognized for a patient-centered approach that values clear communication, shared decision-making, and attention to each patient’s clinical goals and social context. She supports diverse patient communities and is able to care for patients in multiple languages, including English, Hindi, Punjabi, and Urdu. Her clinical work is complemented by scholarly interest in care delivery innovation, including research related to patient satisfaction with teleconsultation in internal medicine outpatient settings. Dr. Hasan is affiliated with Contra Costa Regional Medical Center and holds medical licensure in California and additional U.S. states.

Dr. Jess H. Ghannam, PhD, is a California-licensed clinical neuropsychologist. He is affiliated with the UCSF Institute for Global Health Sciences within the School of Medicine, where his work bridges clinical care, education, and global health. Dr. Ghannam’s clinical interests include behavioral medicine and the psychological impact of chronic medical illness, with experience supporting individuals living with conditions such as chronic pain, cancer, and HIV/AIDS. Dr. Ghannam’s research focuses on the long-term health consequences of war and displacement, including the psychological and psychiatric effects of armed conflict on children. He has contributed to peer-reviewed work examining trauma and mental health in conflict-affected communities. In addition to his academic work, Dr. Ghannam has developed community health clinics in the Middle East that emphasize community-based treatment programs for families in crisis. He has served as a consultant to organizations supporting torture survivors and has worked with international agencies and NGOs assisting refugees and displaced communities. At UCSF, Dr. Ghannam also develops culturally respectful training programs and supports learners across disciplines. His institutional leadership includes directing the UCSF Scholars at Risk Program and serving in faculty leadership and campus climate roles.

Dr. Aubrey Swartz is a board-certified orthopaedic surgeon with extensive experience caring for patients with musculoskeletal conditions, with particular involvement in the evaluation and treatment of spine- and back-related disorders. He earned his medical degree from the University of California, Irvine School of Medicine and completed postgraduate training that included an internship at USC/LAC+USC Medical Center, surgical residency training at Cedars-Sinai Medical Center, and orthopaedic surgery residency training at the University of Miami/Jackson Health System. In addition to his medical training, Dr. Swartz holds a Doctor of Pharmacy (PharmD), reflecting a strong foundation in medication science and its role in patient care. Dr. Swartz has been associated with professional leadership through the American Back Society, supporting ongoing education and interdisciplinary collaboration in back and neck care. He is affiliated with multiple hospital systems, including UCSF Health St. Mary’s Hospital, Highland Hospital, and several medical centers in the Central Valley. Dr. Swartz is licensed to practice in California, Washington, and Oregon, and he speaks both English and Spanish. His approach emphasizes thorough diagnosis, evidence-based treatment, and individualized care for patients seeking relief and improved function.