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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: It is concluded that inhibin B of testicular origin is present in normal human seminal plasma, but with a very wide range in concentration, and may reflect the functional state of the seminiferous epithelium.
Abstract: In men, inhibin B is the circulating isoform involved in the regulation of follicle stimulating hormone (FSH) secretion. Within the testis, inhibin B may have a role in Sertoli and germ cell interactions, thus secretion into seminal plasma may reflect seminiferous tubule function. Using specific immunoassays, inhibin B was present in seminal plasma in fertile men (n = 105) and in unselected men attending an infertility clinic (n = 174) with a wide range in concentration from undetectable (<15 pg/ml) up to 54,100 pg/ml (geometric mean 280 pg/ml). There was a highly significant correlation between seminal plasma inhibin B concentration and sperm concentration (r = 0.46, P < 0.001), but no correlation with percentages of spermatozoa with progressive motility or normal morphology. Inhibin A and isoforms containing pro and alphaC immunoreactivity were not detectable. In post-vasectomy seminal plasma samples (18 of 20) inhibin B was undetectable, indicating that the testis is the predominant source. In unselected men attending an infertility clinic, inhibin B was undetectable in 17% (present in remainder; maximum concentration 26,200 pg/ml; mean 263 pg/ml), with a highly significant correlation between seminal plasma inhibin B and sperm concentration (r = 0.55, P < 0.0001). In men with oligo/ azoospermia (sperm concentration <20 x 10(6)/ml), seminal plasma inhibin B concentrations were lower in those with elevated plasma FSH concentrations (mean values 42 and 205 pg/ml, P < 0.05). Inhibin alpha and betaB subunits were localized predominantly in Sertoli and Leydig cells, using immunohistochemistry. We conclude that inhibin B of testicular origin is present in normal human seminal plasma, but with a very wide range in concentration, and may reflect the functional state of the seminiferous epithelium.

96 citations

Journal ArticleDOI
TL;DR: The fertilizing ability of human spermatozoa is related to sperm morphology, attributes of sperm movement and reactive oxygen species production and time delay between testing and IVF did not appear to affect predictive accuracy.
Abstract: To examine the diagnostic significance of several criteria of semen quality and to determine whether their prognostic value is eroded by the time interval between assessment and the attempt at in-vitro fertilization (IVF) with embryo transfer, 73 couples undergoing IVF and embryo transfer therapy were studied. The ability of human spermatozoa to achieve fertilization in vitro was examined in relation to the conventional semen profile, sperm morphology, the computer-aided assessment of sperm movement, ionophore-induced acrosome reaction, acridine orange staining, and chemiluminescent signals induced by phorbol ester and N-formyl-methionyl-leucyl-phenylalanine (FMLP). Spermatozoa were examined both in semen and after preparation on Percoll, some weeks prior to IVF. Fertilization rates were noted to be significantly correlated with elements of sperm movement characteristics, sperm morphology, and reactive oxygen species generation. Prediction of fertilization rates in a stepwise multiple regression analysis was obtained using four variables: sperm morphology, FMLP-induced chemi-luminescence and sperm movement characteristics (beat cross frequency and straightness) (r approximately 0.5). When multiple logistic regression analysis was used to predict which samples would achieve fertilization rates above and below a 50% threshold, three variables of predictive value including linearity, average path velocity and FMLP-induced chemiluminescence were selected. Combination of these variables classified the samples achieving good or poor fertilization with an overall accuracy of 83.6%. The time interval between semen assessment and IVF had little effect on the predictive value of these tests. In conclusion, the fertilizing ability of human spermatozoa is related to sperm morphology, attributes of sperm movement and reactive oxygen species production. The time delay between testing and IVF did not appear to affect predictive accuracy.

96 citations

Journal ArticleDOI
TL;DR: According to this multiparametric definition, induction of hyperactivity increased significantly (P < 0.0001) the fraction of hyperactive spermatozoa in semen samples and the threshold values of the following four parameters were well suited for differentiating between hyperactive and non-hyperactive boar spermatozosa.
Abstract: Hyperactivity, a form of sperm motility characterized by vigorous flagellar movements, has been proposed as essential for fertilization in mammals. The objective of the present study was to establish a method for inducing hyperactivity in vitro in boar spermatozoa and to define threshold values to differentiate between hyperactive and non-hyperactive spermatozoa by computer-assisted sperm analysis (CASA) as a prerequisite for analyzing the energy metabolism during hyperactivity. In TALP-HEPES medium, non-frozen boar spermatozoa were stimulated to hyperactivity by 50 micromol l(-1) Ca2+ within 15 min at 37 degrees C if 5 micromol l(-1) of the Ca2+ ionophore A23187 was present. If 25% seminal plasma was present, boar spermatozoa required higher Ca2+ concentrations (about 700 micromol l(-1)) for hyperactivity. Under both conditions, immobilization and head-to-head agglutination were low so that hyperactive spermatozoa could be analyzed for at least 40 min. The transition from normal to hyperactive movement was characterized by an increase in flagellar beat angle from 49 degrees +/- 12 degrees to 200 degrees +/- 36 degrees (n = 32) and a decrease in flagellar curvature ratio from 0.89 +/- 0.04 to 0.47 +/- 0.11 (n = 32). For quantification of hyperactive boar sperm, kinematic parameters of hyperactive and non-hyperactive spermatozoa were measured by CASA and statistically evaluated (receiver operating characteristic (ROC) curve analysis). The threshold values of the following four parameters were well suited for differentiating between hyperactive and non-hyperactive boar spermatozoa (ROC curve analysis: > 50% specificity at 100% sensitivity). Hyperactive boar spermatozoa showed mean lateral head displacement > 3.5 microm, curvilinear velocity > 97 microm s(-1), linearity < 32% and wobble < 71%. According to this multiparametric definition, induction of hyperactivity increased significantly (P < 0.0001) the fraction of hyperactive spermatozoa in semen samples from 5.1 +/- 4.3% (n = 13) to 48.3 +/- 6.6% (n = 7) in the absence and to 44.2 +/- 7.6% (n = 10) in the presence of 25% seminal plasma, while the overall percentage of motile spermatozoa did not change significantly.

96 citations

Journal ArticleDOI
TL;DR: The developmental fate of male and female cells in the ovary and testis was evaluated by injecting blastodermal cells from Stage X chicken embryos into recipients at the same stage of development to form same‐sex and mixed‐sex chimeras.
Abstract: The developmental fate of male and female cells in the ovary and testis was evaluated by injecting blastodermal cells from Stage X (Eyal-Gliadi and Kochav, 1976: Dev Biol 49:321-337) chicken embryos into recipients at the same stage of development to form same-sex and mixed-sex chimeras. The sex of the donor was determined by in situ hybridization of blastodermal cells to a probe derived from repetitive sequences in the W chromosome. The sex of the recipient was assigned after determination of the chromosomal composition of erythrocytes from chimeras at 10, 20, 40, and 100 days of age. If the sex chromosome complement of all of the erythrocytes was the same as that of blastodermal cells from the donor, the sex of the recipient was assumed to be the same as that of the donor. Conversely, if the sex-chromosome complement of a portion of the erythrocytes of the chimera differed from that of the donor blastodermal cells, the sex of the recipient was assumed to differ from that of the donor. Injection of male blastodermal cells into female recipients produced both male and female chimeras in equal proportions whereas injection of female cells into male recipients produced only by male chimeras. One phenotypically male chimera developed with a left ovotestis and a right testis although sexual differentiation was usually resolved into an unambiguous sexual phenotype during development when ZZ and ZW cells were present in a chimera. Donor cells contributed to the germline of 25-33% of same-sex chimeras whereas 67% of male chimeras produced by injecting male donor cells into female recipients incorporated donor cells into the germline. When ZW cells were incorporated into chimeric males, W-chromosome-specific, DNA sequences were occasionally present in DNA extracted from semen. To examine the potential of W-bearing spermatozoa to fertilize ova, males producing ZW-derived offspring and semen in which W-chromosome-specific DNA was detected by Southern analysis were mated to sex-linked albino hens. Since sex-linked albino female progeny were not obtained from this mating, it was concluded that the W-bearing sperm cells were unable to fertilize ova. The production of Z-derived, but not W-derived, offspring from ZW spermatogonia indicates that female primordial germ cells can become spermatogonia in the testes. In the testes, ZW spermatogonia enter meiosis I and produce functional ZZ spermatocytes. The ZZ spermatocytes complete the second meiotic division, continue to differentiate during spermiogenesis, and leave the seminiferous tubules as functional spermatozoa. By contrast, the WW spermatocytes do not appear to complete spermiogenesis and, therefore, spermatozoa bearing the W-chromosome are not produced. When cells from male embryos were incorporated into a female chimera, ZZ "oogonia" were included within the ovarian follicles and the chromosome complement of genetically male oogonia was processed normally during meiosis. Following ovulation, the male-derived ova were fertilized and produced normal offspring. This is the first reported evidence that genetically male avian germ cells can differentiate into functional ova and that genetically female germ cells can differentiate into functional sperm.

96 citations

Journal ArticleDOI
TL;DR: These data indicate profound differences in sperm from two siblings with complete round-headed sperm syndrome, which may be responsible for the syndrome and necessitate individual screening of affected individuals because the pattern of expression appears highly variable.

95 citations


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