BOSTON — About half of the state's primary care practices are closed to new patients and wait times to see a primary care physician remain long, according to the results of an annual survey released Monday by the Massachusetts Medical Society. According to the survey of 1,137 doctor's offices, 51 percent of family physicians and 45 percent of internists are accepting new patients. Family physicians and internists are the two most common types of general practitioners. The results are similar to last year's survey that found 50 percent of family doctors and 51 percent of internists open to new patients in Massachusetts.