ABSTRACT
OBJECTIVE: To evaluate the effect of cryopreservation on sperm motility and viability and to assess sperm DNA fragmentation and oxidation in men undergoing infertility investigation before and after cryopreservation in liquid nitrogen. DESIGN: Analysis of cryopreservation effects on sperm DNA integrity. SETTING: Laboratory of Histology-Embryology of medicine faculty, Sfax, Tunisia. PATIENT(S): Fifteen semen samples from men undergoing infertility investigation. INTERVENTION(S): Neat semen samples were cryopreserved in liquid nitrogen using a commercial freezing medium (SpermFreeze, Fertipro, Belgium) according to the manufacturer's instructions. Samples were thawed at room temperature. MAIN OUTCOME MEASURE(S): Sperm DNA fragmentation was assessed using terminal deoxynucleotidyl transferase (Tdt) mediated dUTP nick end labeling and sperm DNA oxidation was determined using a fluorescent assay (OxyDNA test) for the detection of 8-oxoguanine. Evaluation of DNA fragmentation and oxidation rates was carried out before and after cryopreservation using flow cytometry. RESULT(S): A significant decrease in sperm motility and viability was observed after cryostorage. In addition, sperm DNA fragmentation and DNA oxidative damage increased significantly after cryopreservation/thaw. CONCLUSION(S): Cryopreservation has deleterious effects on sperm DNA by inducing DNA fragmentation and oxidation but the mechanisms underlying such damages need to be elucidated by further investigations.
Subject(s)
Cryopreservation , DNA Fragmentation , Oxidative Stress , Spermatozoa/pathology , Adult , Flow Cytometry , Guanine/analogs & derivatives , Guanine/metabolism , Humans , In Situ Nick-End Labeling , Male , Middle Aged , Sperm Count , Sperm Motility , Spermatozoa/metabolism , TunisiaABSTRACT
Heparin, which is used at high doses in hemodialysis patients, may induce antibodies favoring thromboembolic complications. We prospectively investigated the prevalence of heparin-induced platelet-reactive antibodies in a cohort of 38 pediatric hemodialysis patients, by means of heparin/platelet factor 4 (H/PF4) ELISA and heparin-induced platelet activation assay (HIPA). We also assessed other acquired and congenital hypercoagulable states. Heparin-induced antibodies were detected in 13 and 21% of patients with HIPA and ELISA, respectively. Anti-H/PF4 antibodies were negatively correlated with the number of hemodialysis sessions. These antibodies disappeared after a median time of 6 months despite continuing heparin treatment. The prevalence of antiphospholipid antibodies was 21% (anticardiolipin 10.5%, anti-beta2GPI 13%, and lupus anticoagulant 5%). Blood levels of homocysteine, factor VIII, and fibrinogen were significantly higher and factor II levels were significantly lower in hemodialysis patients than in controls, whereas factor VII, factor IX, and natural coagulation inhibitor levels were similar in patients and controls. Overall, 26 of 38 patients had at least one biomarker of hypercoagulability, but only 1 patient, without anti-H/PF4 antibodies, presented with thrombosis. In conclusion, heparin induces the transient production of anti-H/PF4 antibodies in children undergoing hemodialysis, but other abnormalities probably contribute to hypercoagulability. These findings may help to improve the diagnosis and management of thrombotic events in hemodialysis patients.
