نتایج جستجو برای: ejaculated sperm
تعداد نتایج: 36986 فیلتر نتایج به سال:
Although successful fertilization depends on timely encounters between sperm and egg, the decoupling of mating and fertilization often confers reproductive advantages to internally fertilizing animals. In several vertebrate groups, postcopulatory sperm viability is prolonged by storage in specialized organs within the female reproductive tract. In birds, ejaculated sperm can be stored in a quie...
Background: Infertility is estimated to affect up to 15% of couples of reproductive age, and male factors contribute to 50% of these cases. Globozoospermia syndrome is a severe form of teratozoospermia, with an incidence of less than 0.1%. It is characterized by round sperm head. The most prominent feature of globozoospermia is the malformation of the acrosome, which is totally absent in the to...
Single structural defects involving the totality of ejaculated sperm are among rare cases of untreatable human male infertility. This form of infertility is of genetic origin and is generally transmitted as an autosomal recessive traits. Acrosome agenesis or globozoospermia results from perturbed expression of nuclear proteins or from an altered Golgi-nuclear recognition during spermiogenesis. ...
Because of the presence of sperm-storage tubules (SST) in the utero-vaginal junction (UVJ) in the oviduct, once ejaculated sperm have entered the female reproductive tract, they can survive for a prolonged time in domestic birds, although the specific mechanisms involved in the sperm uptake into, maintenance within, and controlled release from the SST remain to be elucidated. In this report, we...
BACKGROUND The effects of cryoinjury were determined simultaneously on the mitochondrial function, motility, morphology and viability of ejaculated human sperm. METHOD Rhodamine 123 (R123) uptake (% of sperm) and stain intensity were used to determine sperm mitochondrial activity before and after cryopreservation from the semen of 50 men attending for infertility investigation. Morphology was...
BACKGROUND Isolation of sperm suitable for ICSI from fresh or frozen-thawed testicular sperm extraction (TESE) can be facilitated by mechanical or enzymatic processing of the samples. METHODS A retrospective multicentre study was initiated to compare these two approaches. Eleven German centres provided data on their TESE cycles performed during the period 1996/1997. Quality of retrieved sperm...
Dysfunctional spermatozoa maturation is the main reason for the decrease in sperm motility and morphology in infertile men. Ejaculated spermatozoa from healthy fertile men were separated into four fractions using three-layer density gradient. Proteins were extracted and bands were digested on a LTQ-Orbitrap Elite hybrid mass spectrometer system. Functional annotations of proteins were obtained ...
OBJECTIVE To examine the presence of cleaved poly(ADP-ribose) polymerase(s) (cPARP) in ejaculated spermatozoa and determine cPARP levels following exposure to chemical or oxidative stress. DESIGN Prospective pilot study. SETTING Tertiary care academic hospital. PATIENT(S) Eight healthy men. INTERVENTION(S) Semen specimens were collected, prepared with double-density-gradient centrifugat...
BACKGROUND We have investigated the expression of voltage-gated sodium channels in human spermatozoa and characterized their role in sperm motility. METHODS Freshly ejaculated semen was collected from thirty normozoospermic human donors, with each donor supplying 2 different samples. Reverse transcription-polymerase chain reaction (RT-PCR) and immunofluorescence techniques were used to detect...
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