نتایج جستجو برای: sperm density
تعداد نتایج: 446003 فیلتر نتایج به سال:
BACKGROUND Anogenital distance (AGD), a sexually dimorphic measure of genital development, is a marker for endocrine disruption in animal studies and may be shorter in infant males with genital anomalies. Given the correlation between anogenital distance and genital development, we sought to determine if anogenital distance varied in fertile compared to infertile adult men. METHODS A cross se...
BACKGROUND Declining fertility of couples from the fourth decade of life is largely attributable to the drop in female fertility. However, increasing numbers of men, whose fertility theoretically lasts until death, are seeking fertility treatment at older ages, yet there is little information on sperm production and function past the age of 50 years. The few studies of such older men have exami...
Sperm DNA damage has a negative impact on pregnancy rates following assisted reproduction treatment (ART). The aim of the present study was to examine the relationship between sperm DNA fragmentation and live-birth rates after IVF and intracytoplasmic sperm injection (ICSI). The alkaline Comet assay was employed to measure sperm DNA fragmentation in native semen and in spermatozoa following den...
in this paper, a new method is introduced for sperm detection in microscopic images for infertility treatment. in this method, firstly a hypothesis testing function is defined to separate sperms from plasma, non-sperm semen particles and noise. then, some primary candidates are selected for sperms by watershed-based segmentation algorithm. finally, candidates are either confirmed or rejected us...
Background: To establish importance of sperm DNA assessment in resolving the unexplained infertility problem. Materials and Methods: This article is based on the careful observation of texts and papers from 2000-2014 about the DNA damage assessment as a significant parameter of sperm function test. Results: Acidic Aniline blue, Sperm Chromatin Dispersion test(SCD), Malondialdehyde concentration...
This is the first report implementing combined density gradient centrifugation/Zeta (DGC/Zeta) sperm selection procedure for a couple with eleven previous intra cytoplasmic sperm injection/ in vitro fertilization (ICSI/IVF) failure cycles. Semen analysis was carried out according to World Health Organization criteria. Protamine deficiency, DNA fragmentation and morphology were assessed by chrom...
In 1992 Carlsen et al. reported a significant global decline in sperm density between 1938 and 1990 [Evidence for Decreasing Quality of Semen during Last 50 Years. Br Med J 305:609-613 (1992)]. We subsequently published a reanalysis of the studies included by Carlsen et al. [Swan et al. Have Sperm Densities Declined? A Reanalysis of Global Trend Data. Environ Health Perspect 105:1228-1232 (1997...
The evolutionary factors affecting testis size are well documented, with sperm competition being of major importance. However, the factors affecting sperm length are not well understood; there are no clear theoretical predictions and the empirical evidence is inconsistent. Recently, maternal effects have been implicated in sperm length variation, a finding that may offer insights into its evolu...
In a seminal paper, Hammerstein and Parker (1987) described how sex roles in mate searching can be frequency dependent: the need for one sex to perform mate searching is diminished when the opposite sex takes on the greater searching effort. Intriguingly, this predicts that females are just as likely to search as males, despite a higher potential reproductive rate by the latter sex. This predic...
In order to study the genetic control of semen quality parameters, we derived a set of recombinant inbred (RI) mice from crosses between two inbred strains, KE and CBA/Kw, which differ significantly in gamete quality and fertility parameters. In this work, we used male mice from the two parental strains and from ten RI strains to map genes controlling quantitative traits such as sperm mitochond...
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