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Semen

About: Semen is a research topic. Over the lifetime, 14571 publications have been published within this topic receiving 407739 citations. The topic is also known as: come & ejaculate.


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Journal ArticleDOI
TL;DR: There is ample evidence that WBC can affect sperm function and further studies are needed to define cofactors that increase or decrease the risk of sperm damage by WBC.

382 citations

Journal ArticleDOI
TL;DR: The data clearly demonstrate that DNA fragmentation, as determined by the TUNEL assay, is predictive for pregnancy in IVF, which implies that spermatozoa with DNA fragmentation can still fertilize an oocyte but that when paternal genes are "switched on," further embryonic development stops, resulting in failed pregnancy.

380 citations

Journal ArticleDOI
TL;DR: The data show no decline in sperm counts over a 25-year period in 1,283 men who banked sperm before vasectomy at three distinct geographical sites in the United States.

379 citations

Journal ArticleDOI
TL;DR: The high levels of ROS production and DNA damage observed in immature spermatozoa may be indicative of derangements in the regulation of spermiogenesis, which is implicated in the pathogenesis of male infertility.
Abstract: BACKGROUND: Reactive oxygen species (ROS)-induced damage of membrane phospholipids and DNA in human spermatozoa has been implicated in the pathogenesis of male infertility. In this study, variations in ROS production, DNA structure (as measured by the sperm chromatin structure assay) and lipid composition, were studied in human spermatozoa at different stages of maturation. METHODS: Sperm subsets were isolated by discontinuous density gradient centrifugation of semen samples obtained from healthy donors and from infertility patients. RESULTS: DNA damage and ROS production were highest in immature spermatozoa with cytoplasmic retention and abnormal head morphology, and lowest in mature spermatozoa. Docosahexaenoic acid and sterol content were highest in immature germ cells and immature spermatozoa, and lowest in mature spermatozoa. The relative proportion of ROS-producing immature spermatozoa in the sample was directly correlated with DNA damage in mature spermatozoa, and inversely correlated with the recovery of motile spermatozoa. There was no correlation between DNA damage and sperm morphology in mature spermatozoa. CONCLUSIONS: The high levels of ROS production and DNA damage observed in immature spermatozoa may be indicative of derangements in the regulation of spermiogenesis. DNA damage in mature spermatozoa may be the result of oxidative damage by ROS-producing immature spermatozoa during sperm migration from the seminiferous tubules to the epididymis.

373 citations

Journal ArticleDOI
TL;DR: The evidence for the lower temperature of the testes of many mammals is summarized, and the reasons suggested for the descent of thetestes into a scrotum are discussed.
Abstract: The evidence for the lower temperature of the testes of many mammals is summarized, and the reasons suggested for the descent of the testes into a scrotum are discussed. Descriptions are given of the various techniques used for studying the effects of heat on the testis, whole body heating, local heating of the testes (by inducing cryptorchidism, scrotal insulation or immersion of the scrotum in a water bath), and heating of tissue or cell preparations in vitro. The effects of heat are discussed, effects on the testis (weight, histology, physiology, biochemistry and endocrinology), on the numbers and motility of spermatozoa in rete testis fluid and semen, on fertilizing ability of spermatozoa and on the subsequent development of the embryos produced when spermatozoa from heated testes are used to fertilize normal ova. The possible mechanisms for the damaging effects of heat are discussed, as well as the importance of heat-induced abnormalities in male reproduction in domestic animals and humans.

372 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20241
2023973
20222,093
2021538
2020530
2019498