Our Staff

Our Physicians & Staff

Leatrice Chang, M.D.
Leatrice Chang, M.D.

Attended Tufts University of Boston, graduated in 1979 and was board certified in Family Practice in 1982. She is on staff at Summit Medical Center of Oakland and John Muir Medical Center in Walnut Creek.

Mei Chow Kwan, M.D.
Mei Chow Kwan, M.D.

Graduated from University of Hong Kong in 1986, completed her residencies in affiliation with Johns Hopkins University and Tufts University. She is Board Certified in Internal Medicine, and is an Assistant Clinical Professor at UCSF. She’s been in practice in Walnut Creek since 1994 and is on staff at John Muir Medical Center. Her breadth of practice involves Internal Medicine, Women’s Health and common psychological issues. She like gardening, travelling and arts. She believes in active, balanced, positive living, regular health maintenance and proactive measures to enjoy our health and to minimize the use of medications. Dr. Chow Kwan is fluent in Mandarin and Cantonese.

Mary Lowen, M.D.
Mary Lowen, M.D.

Attended medical school at the University of Kansas. Dr. Lowen performed her postgraduate work at the University of Irvine in 1977. Dr. Lowen started practicing medicine in 1978. Dr. Lowen is also a fellow of AAFP and is board certified in family practice.

Jolanta Omski, M.D.
Jolanta Omski, M.D.

Attended Univ. of California San Diego. She received her medical degree from Karol Maroinkowski University of Medical Science, Poznan, Poland in 1999. She completed a three year residency in Family Practice at the University of North Dakota and is Board Certified in Family Practice.

Maeve O’Regan, M.D.
Maeve O’Regan, M.D.

Dr. O’Regan attended the University of Cape Town, South Africa and practiced medicine in Cape Town until moving to the United States. She spent three years at Highland Hospital in Oakland, CA and became board certified in Internal Medicine in 1997. She enjoys hiking, kayaking and quilting in her spare time.

Catherine Wang, M.D.
Catherine Wang, M.D.

Received her medical degree from UMDNJ - New Jersey Medical School in 1998 and completed her residency in family practice at UCSF Family and Community Medicine Residency Program in 2001. She is Board Certified in Family Practice and member of the American Academy of Family Physicians (AAFP) and California Academy of Family Physicians (CAFP). She and her husband Dave reside in Walnut Creek with their 2 daughters. She enjoys hiking, running, tennis, and music.

Diane Wight, M.D.
Diane Wight, M.D.

Attended U.C. Berkeley in 1974 - 1977. Dr. Wight studied pre medicine with a major in Spanish. She received her medical degree from the Medical Academy of Warsaw, Poland in 1983. She completed a 3-year residency in Family Practice in 1986 at the Williamsport Hospital in Williamsport, PA. and is Board Certified in Family Practice.

Our Staff