OBJECTIVE To study the resistance of human spermatozoa to cryoinjury in repeated cycles of thaw-refreezing by using the fast liquid nitrogen vapor method. MATERIALS AND METHODS Semen specimens were obtained from sixteen normal and oligozoospermic individuals who required disposal at the sperm bank. Five of them had testicular cancer. Specimens were thawed and an aliquot was removed for analys...

BACKGROUND Spermatozoa have to traverse the cumulus oophorus before fertilization in vivo. Evidence suggests that the cumulus oophorus plays an important role in the fertilization process. We describe the establishment of a capillary-cumulus oophorus model with which to study the action of cumulus mass on the function of human spermatozoa. METHODS Human cumulus oophorus was aspirated into a g...

This study demonstrates the presence of [3H]-progesterone binding protein on the cell surface of human spermatozoa. The binding protein is masked and is exposed after treatment of spermatozoa with surfactants such as digitonin. Specific binding of [3H]-progesterone is observed after the washed spermatozoa or the crude cell membrane fractions are treated with 0.1% digitonin at 0-4 degrees C for ...

The effects of follicle stimulating hormone (FSH) treatment on the quality of human spermatozoa were assessed by examining the ultrastructure and the function of infertile human spermatozoa using a previously-defined formula. Using the spermatozoa as an andrological monitor shows that the therapeutic effect of FSH depends on the type of sperm defect. The response to FSH is, in many cases, posit...

objective(s):althoughroutinely applied in assisted reproductive technology, human sperm cryopreservation is not a completely successful procedure. adverse effects of cryopreservation on the fertilization capacity, motility, morphology, and viability of spermatozoa have been proven; cryopreservation has also shown a role in sperm dna fragmentation and infertility. the post-thaw survival of sperm...

DNA damage is frequently encountered in spermatozoa of subfertile males and is correlated with a range of adverse clinical outcomes including impaired fertilization, disrupted preimplantation embryonic development, increased rates of miscarriage and an enhanced risk of disease in the progeny. The etiology of DNA fragmentation in human spermatozoa is closely correlated with the appearance of oxi...

BACKGROUND Sperm aster organization during bovine and human fertilization requires a paternally-derived centriole that must first disengage from the sperm tail connecting-piece. We investigated the participation of the 26S proteasome in this process. METHODS Proteasome localization and enzymatic activity were studied in normal and pathological human spermatozoa by immunocytochemistry and enzyme...

Mammalian sperm acrosomes contain a trypsin-like protease called acrosin which causes limited and specific hydrolysis of the extracellular matrix of the mammalian egg, the zona pellucida. Acrosin was localized on hamster, guinea-pig and human sperm using monoclonal and polyclonal antibodies to human acrosin labelled with colloidal gold. This was visualized directly with transmission electron mi...