title: Cryogenic preservation of low-quality human semen.
abstract: The article describes the technical strategies for clinical cryogenic preservation of low-quality human semen. To compensate for sperm dilution resulting from the use of a cryogenic medium, ejaculated semen was concentrated before freezing by means of continuous-step density gradient centrifugation. Freezing was simplified by employing the carbon dioxide pellet method with KS-II cryogenic medium, which contains Pluronic F-68, a nonionic detergent, to solubilize egg yolk (a major cryogenic protectant). Semen of less than 50% motility (n = 23) was processed and then cryogenically preserved. Sperm concentration was increased by a factor of 1.8 +/- 0.96 (n = 23). Sperm motility was improved from 35.9% +/- 13.9% to 69.4% +/- 10.8%. Even after thawing 59.4% +/- 17.5% motility remained, with a mean survival rate of 85% +/- 14%. The concentration of sperm and improved sperm motility by the use of the continuous-step density gradient and the high survival rate ensured by the carbon dioxide pellet method with KS-II cryogenic medium compensated for the lowering of sperm quality during cryogenic preservation.
authors.affiliation: Department of Obstetrics and Gynecology, Ichikawa General Hospital, Tokyo Dental College, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Kaneko
authors.forename: T
authors.initials: T
authors.lastname: Kobayashi
authors.forename: H K
authors.initials: HK
authors.lastname: Lee
authors.forename: W K
authors.initials: WK
authors.lastname: Won
authors.forename: T
authors.initials: T
authors.lastname: Oda
authors.forename: Y
authors.initials: Y
authors.lastname: Izumi
authors.forename: T
authors.initials: T
authors.lastname: Ohono
authors.forename: R
authors.initials: R
authors.lastname: Iizuka
mesh_terms: D002499:Centrifugation, Density Gradient; D015925:Cryopreservation / Q000009:adverse effects / Q000379:methods*; D004305:Dose-Response Relationship, Drug; D005990:Glycerol / Q000494:pharmacology; D006801:Humans; D008297:Male; D011060:Poloxalene / Q000494:pharmacology; D012662:Semen Preservation / Q000379:methods*; D013081:Sperm Motility / Q000187:drug effects
chemical_list: D011060:Poloxalene; D005990:Glycerol