Cerebrovascular disease is currently one of the major diseases that result in the deaths of human.Its incidence elevates year by year,and there is a trend of younger.Stroke in young adult accounts for 25％ ～ 33％ in all stroke patients.Once a young man has a stroke,his quality of life will drop dramatically,and it will also bring a heavy burden to the family and society.Therefore,the etiologies of stroke in young adults should be summarized in order to achieve early diagnosis and early treatment.It is very important for improving of their prognoses.Cryptogenic stroke accounts for about 30％ in all strokes.The possible etiologies of cryptogenic stroke in young adults include heart diseases,arthritis,artery dissection,obstructive sleep apnea syndrome,and drug abuse,etc.

In order to explore the effects of diet and nutritional factors on breast cancer incidence, a case-control study was conducted in Tianjin. The study consisted of 244 cases diagnosed between September 1986 and September 1987 and equal number of matched controls from patients other than breast cancer in general hospital.The socio-demographic data, histories of menstruation and reproduction etc were collected by interview. The interview on diet was conducted by recalling the frequencies and amounts of various foods eaten one year prior to the diagnosis' of their current diseases. Data were analysed by using a nutrient-estimate program and conditional logistic regression model, chi square test and u-test.After adjusting for confounding factors, the results showed that high fat, high calorie, high monounsaturated fatty acid and low vitamin C intakes were risk factors for female breast cancer. High fat percentage of energy and low vegetable intake were associated with increased risk for breast cancer.