Ejaculated mammalian sperm must acquire fertilization capacity after residing into the female reproductive tract, a process collectively known as capacitation. Cholesterol efflux was required for sperm maturation. Different from flagellated sperm, C. elegans sperm are crawling cells. C. elegans sperm are highly enriched with cholesterol though this animal species lacks biosynthetic pathway for ...

Phosphorylation of tyrosine residues on sperm proteins is one important intracellular mechanism regulating sperm function that may be a meaningful indicator of capacitation. There is substantial evidence that cryopreservation promotes the capacitation of sperm and this cryocapacitation is frequently cited as one factor associated with the reduced longevity of cryopreserved sperm in the female r...

BACKGROUND We evaluated the impact of using ICSI for assisted fertilization on first trimester survival rates of singleton gestations among an unselected infertile population. METHODS The 1244 singleton gestations achieved by ICSI were segregated according to underlying infertility aetiology, with 55.0% having male factor, 3.6% endometriosis, 4.3% polycystic ovarian disease, 9.1% tubal factor...

Twelve Charolais bulls were ejaculated once weekly (1• and 10 bulls six times weekly (6• from puberty to 2 years of age to determine the effect of age and ejaculation frequency on semen characteristics, sperm output and testes growth; 6• weekly sperm output at 2 and 3 years of age was determined for each of the 22 bulls. Significant increases as bulls aged were found in sperm concentration, spe...

Four distinct studies were carried out using two data sets of percutaneous epididymal sperm aspiration (PESA) and intracytoplasmic sperm injection (ICSI) procedures performed from March 1993 to January 1997. In study A, an analysis of 181 ICSI treatment cycles following PESA revealed a successful epididymal sperm retrieval rate of 83%. It confirmed that PESA is an effective sperm retrieval meth...

BACKGROUND Detection of apoptosis in sperm samples may help evaluate sperm quality. Recently, it has been suggested that in some ejaculated sperm populations, apoptosis is caspase dependent. The aim of this study was to investigate the presence of activated caspases and examine possible correlations with apoptosis and sperm parameters in semen samples prepared for IVF. METHODS To detect activ...