Our Medical Providers

Dr. Silva was born and raised in Boyle Heights. He graduated from Abraham Lincoln High School, enjoyed playing football and was class president his senior year. He attended UC Riverside and received his Bachelor of Science degree in 1992. He went on to UC Davis medical school, receiving his MD degree in 1998. Dr. Silva completed his internship and residency program at White Memorial Medical Center and Family Care Specialists group. He is currently a hospitalist at White Memorial Medical Center and at Monterey Park Hospital in addition to his private practice here at Mosaic Family Care. It was always his dream to start a clinic here in his own home town, and in 2001, alongside Dr. Lisa Ma, his dream was finially realized. 

Dr Ma graduated with honors from the University of California, Riverside; earned her Medical Degree at Loma Linda University, School of Medicine; and completed her Family Medicine residency at (nearby) White Memorial Medical Center. Born in Cincinnati, Ohio, Dr Ma comes from a diverse cultural background and speaks fluent English, medical Spanish, basic Japanese and Chinese. In addition to her training in traditional medicine, Dr. Ma has also pursued furthering education in natural remedies and has developed a unique holistic skill set with a focus in integrative care. She is far from your average physician and believes she was placed on this earth to help others. In this pursuit, Dr. Ma organizes yearly aid trips to Mexico which include medical, dental, and construction assistance to under-served communities.  

Dr. Hector Castillo is Board Certified by the American Board of Family Medicine.  He graduated from Occidental College where he received a Bachelor of Arts in Biology.  He graduated from Keck School of Medicine at USC.

He has been in practice for 14 years.

He is currently a primary care physician and a hospitalist.  Dr. Castillo serves on multiple clinical leadership committees at White Memorial Medical Center and at AltaMed Health Services.  He is a proud husband and father of three wonderful children.  He coaches flag football and enjoys time with his family.

 Dr. Cowan (DNP) was born in California and raised by her Thai mother who served as an RN in charge of a community hospital. Dr. Cowan’s mother was a “hero” in her eyes. She watched her mother integrate herbs, vitamins and natural remedies with traditional medical treatments to better balance the body and treat diseases for the patients she worked with and treated. Dr. Cowan learned and embraced this holistic model from her “hero” and wanted to create this same model as she developed her own practice moving forward.  Dr. Cowan has a solid background in both conventional medicine and integrative medicine, making it easy for her to practice both areas optimally and provide the best approach for her patients. Dr. Cowan attended Frontier Nursing University earning her Doctorate of Nursing Practice. She completed her residency with Mosaic Family Clinic and soon after joined the practice.  

Dr.Leslie Klein was born and raised in Los Angeles. She majored in Biophysics at UC Berkeley, graduating in 1989, then completed her D.O. medical degree at Western University of Health Sciences in Pomona, CA. Her Family Practice Residency was at Whittier Presbyterian Hospital in Whittier, CA.. She speaks Spanish and some Sign Language. She has spent a lot of time in jungles and remote areas of Latin America, Asia, and Africa, and also diving and swimming in oceans ! She still loves  traveling, gardening ( has a food forest ) and swimming with fish and whales.

James was born in So Cal, raised in Boyle Heights and the San Gabriel Valley.  He has 25+ years of experience as an RN, 7+ years as a Nurse Practitioner.  He has graduated from CSULA 2009 with an MSN, Family Nurse Practitioner focus, ANCC certified. His FNP experience includes Urgent Care, Family Practice, and Pediatrics. He enjoys working with children and their families.  His passio includes mountain biking, trail running, volunteering, video games, and exploring California.