نتایج جستجو برای: sperm density
تعداد نتایج: 446003 فیلتر نتایج به سال:
The existence of a complex population of mRNA in human sperm is well documented but their role is not yet elucidated. Using discontinuous density gradients, we have isolated high and low motile sperm from the same semen sample. The levels of different transcripts coding for molecules either involved in nuclear condensation (protamines 1 and 2) or in capacitation [endothelial nitric oxide syntha...
Background sperm selection is generally used to describe methods for separation of spermatozoa for in-vitro-assisted reproduction. Few studies reported relation in vivo fertility and semen parameters after selection of fertile spermatozoa; hence, our research attempt to assess different semen parameters after post-thaw (PT) or after selecting sperm sample (SSp), using density gradient separatio...
Background Low-density lipoproteins (LDL) is known to protect boar sperm during freezing–thawing, but little information is known about the effects of LDL extracted from different avian egg yolks on post-thaw boar semen quality. The purpose of this study was to compare and analyze the effects of LDL at various concentrations and different species on boar sperm quality after freezing–thawing. Ma...
BACKGROUND The intra-cytoplasmic sperm injection (ICSI) technique selects sperm according to morphology and motility. However, these parameters cannot predict the chromatin integrity of sperm. Considering the detrimental effects of DNA-damaged sperm on reproductive outcomes, novel sperm selection procedures have been proposed to circumvent the possibility of inseminating DNA-damaged sperm. It h...
Comparative studies documenting a relationship between male gonadal investment and the degree of sperm competition (SC) have usually considered the association between these traits to be driven by qualitative differences in the mating system, such as whether spawning occurs in pairs or groups. However, ecological and demographic differences between conspecific populations may also generate vari...
Males of many species adjust their reproductive behaviour according to the perceived risk of sperm competition. Although this phenomenon is widespread in insects and other animals, the mechanisms that allow mates to assess sperm competition levels remain largely unexplored. In this study, we analysed the mating behaviour of pairs of Tenebrio molitor beetles under three odour treatments represen...
Background: Super-paramagnetic annexin-V conjugated micro-beads are able to eliminate sperm with phosphatidylserine externalization (PSE). PSE is considered as apoptotic sperm. PES positive sperm can be removed from sperm preparations sample to enhance sperm quality for assisted medical procreation. Therefore, the efficiency of this technique over normal sperm processing procedure such as densi...
Management of people infected by HTLV-1 in assisted reproductive technology (ART) is a rare event. Since HTLV is sexually transmitted, HTLV serodiscordant couples have to systematically use condoms. The sperm processing (centrifugation on density gradient) performed for semen of HIV-infected men was applied. Detection of HTLV-1 provirus DNA was negative before and after sperm processing, allowi...
Classic therapies are usually ineffective in the treatment of patients with very poor sperm density. The aim of this study was to determine the effect of acupuncture on these males. Semen samples of 20 patients with a history of azoospermia were examined by light microscope (LM) and scanning electron microscope (SEM), with which a microsearch for spermatozoa was carried out. These examinations ...
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