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Nina Cheung, M.D.

Medical Director & Physician

Dr. Cheung is the Medical Director and Consulting Physician
of our Primary Care Unit, with oversight of occupational medicine,
worker’scompensation, DOT drug screening, provider scheduling, co-
ding, and billing across three locations. Previously, she was an award-winning phys-
ician at Hahnemann University Hospital and Drexel University College of Medicine in
Philadelphia, Pennsylvania. Dr. Cheung is passionate about promoting health awareness
through community outreach and public speaking. She also has a gift for developing caring
and knowledgeable healthcare professionals through training and mentorship.

Dr. Cheung holds medical licenses in three states and is certified by the American Board of Internal Medicine. Additionally, she is a Certified Medical Examiner, Medical Review Officer, and Breath Alcohol Technician. She earned a Doctor of Medicine Degree from Drexel University College of Medicine and a Bachelor’s Degree from the University of the Sciences.

Robert Antonio

Robert Antonio DaSilva, M.D.


Dr. DaSilva is a highly educated staff physician specializing in urgent care. Since 1996, he has provided care for adult, geriatric, and pediatric patients in both emergency room and ambulatory care clinic settings at St. Vincent’s Hospital, Midtown Health Center, and La Clinica del Barrio in New York. He also served as a clinical instructor and preceptor for the residents and medical students in the Pediatric and Internal Medicine clinics and inpatient wards at Metropolitan Hospital/ New York Medical College.

Dr. DaSilva is licensed in both New Jersey and New York, and holds certifications by the American Board of Internal Medicine and the American Board of Pediatrics. He earned a Doctor of Medicine Degree from the Mt. Sinai School of Medicine and a Bachelor’s Degree from S.U.N.Y. at Binghamton. Among his many credentials include DEA and CDS registrations and FMCSA, BLS, PALS, and ACLS certifications. His broad training ranges from CDC concussion and NYS DOH infection control to mandated reporting.

John Murphy

John Murphy, MD


John Murphy is a Board Certified Physician in the State of New Jersey, committed to providing compassionate, urgent, and state-of-the-art medical care to the community. His expertise and dedication is demonstrated through nearly 20 years of experience as a Private Practice Physician in New Jersey and New York.

Prior to joining Astra Health as a Private Practice Physician, Dr. Murphy was a Clinical Faculty member for 14 years in the Family Medicine Residency Program at Hoboken University Medical Center. Previously, he served as a Private Practice Physician for 6 years at Downtown Integrated Medical Services in Brooklyn, New York.

Dr. Murphy earned a Doctor of Medicine Degree from the University of Medicine and Dentistry of New Jersey in 1997 and completed his internship/residency at St. Mary Hospital in New Jersey. Additionally, he holds a Bachelor of Science in Electrical Engineering from Rutgers College of Engineering in New Jersey.

Saima Butt

Saima Butt, M.D.


Dr. Butt is a staff physician providing services that include urgent care, occupational medicine, worker’s compensation, and DOT physicals. She has treated obstetric, pediatric, adolescent, adult, and geriatric patients in inpatient, outpatient, and emergency care settings for over ten years. She is a skilled communicator and educator who speaks five languages and has a special interest in community outreach, preventative health, women’s health, urgent care, and teaching.

Dr. Butt was a family physician and partner in a large physician-owned medical group in Indiana and completed a family medicine residency at Ball Memorial Hospital in Indiana. She holds a Doctor of Medicine Degree from the Universidad Technologica de Santiago (Dominican Republic) and a Bachelor’s Degree from Loyola University (Illinois).

Heather DeNigris

Heather DeNigris, PA-C

Physician Assistant

Heather DeNigris is a Certified Urgent Care Physician Assistant servicing patients in Basking Ridge, Hoboken, and Bayonne, New Jersey. Her diverse career spans extensive clinical clerkships at New York hospitals, private practices, long-term care facilities, and medical centers, in the areas of Emergency Medicine, Surgery, Internal Medicine, Psychiatry, Primary Care, Pediatric Medicine, Geriatrics, and OBGYN. Heather also worked as a Family Medicine Physician Assistant and Medical Technologist in award-winning, state-of-the-art environments such as Newark Beth Israel Medical Center and Memorial Sloan Kettering Cancer Center.

Heather holds Physician Assistant licenses and Laboratory Technologist certifications in both New Jersey and New York. She earned Bachelor’s and Master’s Degrees in Physician Assistant Studies from Touro College (New York) as well as joint Bachelor’s Degrees in Clinical Laboratory Sciences from Rutgers University (New Jersey). She is a Drug Enforcement Administration Certified Medical Prescriber and a DOT Nationally Certified Medical Examiner. Additional certifications include ACLS, BLS, and PLS.

Tiffany Johnson

Tiffany Johnson, PA-C, MPAS

Physician Assistant

Tiffany Johnson is a Certified Physician Assistant specializing in urgent and primary care for adults and children, inc luding sick visits, laceration repair, x-rays, splinting, worker’s compensation, occupational medicine, and DOT physicals. In her previous role as a Senior Physician Assistant at South Shore Medical Care in New York, she was acknowledged for consistently exceeding quality, time, and service standards.

Tiffany’s dedication to a healthcare career is evidenced by multiple degrees and credentials, in cluding ACLS, BLS, DOT, and ACSM concussion certifications. She graduated cum laude from Touro College of Health Sciences in New York, earning a Master’s Degree in Physician Assistant Studies and a Bachelor’s Degree in Health Sciences. She also holds a Bachelor’s Degree in Neuroscience from Muhlenberg College in Allentown, Pennsylvania. Tiffany is licensed by the National Committee on Certification of Physician Assistants and the State Board of Physician Assistant Examiners in both New Jersey and New York.

Lorraine Saunders

Lorraine Saunders, PA-C

Physician Assistant

Lorraine Saunders has been a highly respected Physician Assistant in the States of New Jersey and New York since 1995. Known for her empathy, compassion, focus, and patience, Lorraine has provided care to adult, pediatric, mentally ill, high acuity, and low acuity patients in medical centers, physician practices, acute care settings, and trauma centers.

As a flexible and supportive team player, Lorraine consistently takes on added responsibilities and leadership roles. During her 7-year tenure at Raritan Bay Medical Center, Lorraine created schedules for physician assistants and nurse practitioners, and initiated a shadowing and mentoring program for new students. While managing critical care patients in the Department of Emergency Medicine at Brookdale University Medical Center for 12 years, Lorraine trained medical students and physician assistant students.

A proud member of the military forces since 2000, Lorraine earned the rank of Major in the Army National Guard Medical Service Corps. She developed efficacious treatment plans for injured soldiers and served as a liaison between the higher command in Iraqi, the soldiers, and their families at Walter Reed Army Medical Center.

In addition to a Bachelor’s Degree in Health Sciences from Touro College, Lorraine holds a Juris Doctor from Pace University School of Law.

Ghulam Mehmood

Ghulam Mehmood, PA-C

Physician Assistant

Ghulam Mehmood is a highly educated Urgent Care Physician Assistant with a Master’s Degree and certifications in Basic Life Support, Advanced Cardiac Life Support, Infection Control, Child Abuse/Neglect, and HIPAA.

Ghulam has treated patients as an Orthopedic Physician Assistant at New York Ortho Care since 2014, with surgical privileges in New York-Presbyterian/Lower Manhattan Hospital, Wyckoff Heights Medical Center, Midtown Surgical Center, and Surgicare of Jersey City. He is an active member of the Physician Assistants in Orthopaedic Surgery and American Academy of Physician Assistants.

While earning a Master of Science in Physician Assistant Studies from New York Institute of Technology, Ghulam was elected Class President and received an award for Physician Assistant Leadership. Additionally, he holds a Bachelor of Science in Psychology from City University of New York Brooklyn College. During his academic years, Ghulam worked as a research assistant, tutor, and was selected to present a publication for peer review by the Editorial Board of the Journal of American Academy of Physician Assistants.