Ruth Rothstein, retired chief executive officer of Mount Sinai Hospital in Chicago and former head of the Cook County Bureau of Health Services, died Aug. 4 at age 90.

Rothstein was somewhat of a legend in Chicago, a dynamic and tough advocate for the poor. A native of Brooklyn, she moved to Chicago in 1950 as a union organizer. Her health care career began as a lab technician at a union HMO. She moved on to the lab at Chicago's Jackson Park Hospital, and then became director of the personnel office, which hospital leaders created at her behest.

According to the Chicago Tribune, in the 1960s, Rothstein was turned down for the job she applied for at Mount Sinai Hospital and was offered a secretarial position instead because she had no college degree. "I don't type," she told the director. She did get an administrative post there in 1966 and worked her way up to president and CEO in 1977. She retired in 1991, and became chief of the Cook County Bureau of Health Services, now called the Cook County Health and Hospitals System, where she helped develop a system of primary health care clinics for the poor and spearheaded construction of the John H. Stroger Hospital. She was behind the creation of a clinic for patients with HIV, AIDS and other infectious diseases, the Ruth M. Rothstein CORE Center. She retired from the Cook County position in 2004 after turning 80. Until her death, she served on the board of the Rosalind Franklin University of Medicine and Science.

Rothstein's husband, David B. Rothstein, died in 1984. She is survived by her son Jonathan; her daughter, Martha; her grandson, Max; and two brothers, Larry Merson and Jack Merson.