日韩av大片在线观看欧美成人不卡|午夜先锋看片|中国女人18毛片水多|免费xx高潮喷水|国产大片美女av|丰满老熟妇好大bbbbbbbbbbb|人妻上司四区|japanese人妻少妇乱中文|少妇做爰喷水高潮受不了|美女人妻被颜射的视频,亚洲国产精品久久艾草一,俄罗斯6一一11萝裸体自慰,午夜三级理论在线观看无码

Prostate-specific antigen （PSA; also known as human kallikrein-related peptidase 3）, a 237-amino-acid glycoprotein （33 kDa） that belongs to the kallikrein serine protease family, is produced by the glandular epithelium of the human prostate and secreted in seminal fluid. PSA plays a principal role in the proteolysis of semenogelins I and II from seminal coagulum. Prostate-specific antigen （PSA） is a serum marker that is widely used for the diagnosis of prostatic diseases. Measurement of the free fraction of total prostate-specific antigen （fPSA%） has been proposed as a useful addition to total PSA for the detection of prostate cancer.