seminal plasma 18 human 14 male 14 article 12 Male 10 controlled study 10 human cell 10 priority journal 10 spermatozoon 10 Spermatozoa 8 normal human 8 spermatozoon motility 8 Human 6 Humans 6 Semen 6 enzyme activity 6 Article 4 Bovine seminal plasma 4 Chromatography, Gel 4 Chromatography, High Pressure Liquid 4 Glyco)proteins 4 Glycopeptides 4 Hexosaminidase 4 Nor-harmane 4 Sinapinic acid 4 Support, Non-U.S. Gov't 4 UV-MALDITOF MS 4 acrosome 4 asthenospermia 4 beta n acetylhexosaminidase 4