نتایج جستجو برای: sperm density
تعداد نتایج: 446003 فیلتر نتایج به سال:
BACKGROUND There are reports showing that l-carnitine alone or in combination with other micronutrients improve sperm parameters. However, comparative studies are still lacking. This study was carried out to compare the short term effects of a combination of eight micronutrients including l-carnitine vs. a mono-substance (l-carnitine alone) on sperm parameters. METHODS This was a prospective,...
There is a fundamental body of evidence suggesting that activated apoptosis signaling in ejaculated human sperm negatively influences their fertilization potential. However, it is still controversial whether this apoptotic signaling is a relic of an abortive apoptosis related to spermatogenesis or if it should be regarded as a functional preformed pathway in mature sperm leading to stereotypica...
Evidence is increasing that the integrity of sperm DNA may also be related to implantation failure and recurrent miscarriage (RM). To investigate this, the sperm DNA fragmentation in partners of 35 women with recurrent implantation failure (RIF) following in vitro fertilization, 16 women diagnosed with RM and seven recent fathers (control) were examined. Sperm were examined pre- and post-densit...
The number of mating partners an individual has within a population is a crucial parameter in sex allocation theory for simultaneous hermaphrodites because it is predicted to be one of the main parameters influencing sex allocation. However, little is known about the factors that determine the number of mates in simultaneous hermaphrodites. Furthermore, in order to understand the benefits obtai...
Low-density lipoprotein (LDL) extracted from hen egg yolk has recently been considered to be superior to whole egg yolk in sperm cryopreservation of various animal species. Meanwhile, there was a notion that high-density lipoprotein (HDL) in egg yolk may have a negative effect on post-thaw survival. The role of LDL and HDL in sperm cryopreservation of rhesus monkeys has not been explored. The p...
introduction: cd59 is a complement control protein (ccp) wich exhibits its inhibitory functions by prevention of complement attack complex (max) formation. the aim of this normozoospermia, olig-astheno and azoospermia. materials and methods: the semen of 57 individual were grouped to normozoospermia (8), asthenozoospermia (21), oligo-astenozoospermia (16), and azoospermia (12) according to who ...
BACKGROUND We hypothesized that C. borivilianum root, known to improve male reproductive performance, prevents impairment in characteristics, morphology and elevation of oxidative stress in sperm of diabetics. We therefore investigated the effect of aqueous root extract of C. borivilianum on these parameters in diabetic rat model. METHODS C. borivilianum root aqueous extract (250 and 500 mg/k...
The present study was designed to evaluate kinematic response of sperm cell to low-density lipoproteins (LDL) in fresh diluted, short-term (4°C) or long-term (-196°C) stored semen. Four healthy bucks of similar age and weight were selected as semen donor. The semen was collected twice a week using artificial vagina. The semen after initial evaluation was pooled and divided into three aliquots, ...
Traditionally, the diagnosis of male infertility has relied upon microscopic assessment and biochemical assays to determine human semen quality. The conventional parameters given most importance have been the concentration, motility, and morphology of sperm in the ejaculate. Most laboratories also include 'sperm suitability' tests where the subpopulations of sperm more likely to finish the mara...
Theory assumes that postcopulatory sexual selection favors increased investment in testes size because greater numbers of sperm within the ejaculate increase the chance of success in sperm competition, and larger testes are able to produce more sperm. However, changes in the organization of the testes tissue may also affect sperm production rates. Indeed, recent comparative analyses suggest tha...
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