Showing papers on "Semen published in 1998"
TL;DR: The study suggests that the current WHO guidelines for normal semen quality should be used with caution, as some men with sperm counts above the lower limit of the normal range defined by WHO may in fact be subfertile.
703 citations
TL;DR: The results suggest that when poor-quality semen samples are used for ICSI, there is a greater likelihood that some sperm selected for injection, despite appearing normal, contain fragmented DNA.
485 citations
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
TL;DR: The results indicate that human sperm chromatin becomes cross-linked under conditions of oxidative stress and exhibits increased DNA strand breakage, yet the rate of pronucleus formation is no different from that of untreated control cells.
Abstract: We present the first evidence that genetically damaged human spermatozoa are able to form normal pronuclei in oocytes after intracytoplasmic sperm injection (ICSI). The role of reactive oxygen species (ROS) as a cause of chromatin and DNA damage is well recognized. The same class of molecule can be found in the semen of males with severe infertility, who remained infertile until the advent of ICSI. In this study we have investigated the role of ROS in the induction of chromatin damage, DNA strand breakage and the subsequent ability of spermatozoa to decondense and form pronuclei after ICSI. Spermatozoa from normozoospermic men participating in our research programme were exposed to oxidizing environments created by co-incubation with hydrogen peroxide, reduced nicotinamide adenine dinucleotide phosphate (NADPH) or activated white cells. The subsequent ability of the spermatozoa to decondense in vitro was examined using sequential incubations in EDTA, dithiothreitol and sodium dodecyl sulphate, and the amounts of DNA strand breakage were assessed using an in-situ nick translation protocol. Finally, cells exposed to hydrogen peroxide, NADPH and activated leukocytes were microinjected into hamster oocytes, and their ability to decondense and form normal pronuclei was determined. The results indicate that human sperm chromatin becomes cross-linked under conditions of oxidative stress and exhibits increased DNA strand breakage, yet the rate of pronucleus formation is no different from that of untreated control cells. The ability of genetically damaged spermatozoa to achieve normal fertilization following ICSI has implications for the practice of this form of assisted conception therapy.
358 citations
TL;DR: Both qualitative and quantitative virologic measurements were compared between blood and genital compartments for 128 men infected with human immunodeficiency virus type 1 to address several controversial issues concerning HIV-1 shedding in semen and to obtain further information about the distribution of virus between these two compartments.
Abstract: Both qualitative and quantitative virologic measurements were compared between blood and genital compartments for 128 men infected with human immunodeficiency virus type 1 (HIV-1) to address several controversial issues concerning HIV-1 shedding in semen and to obtain further information about the distribution of virus between these two compartments. Evidence for viral compartmentalization was suggested by earlier studies that noted the poor correlation between blood and seminal virus load, phenotype, and genotype. Further support for this viral compartmentalization was based on the following observations between semen and blood: lack of association between culturability of virus in semen and viral RNA level in blood, discordant distribution of viral phenotypes, discordant viral RNA levels, a weak correlation between viral RNA level in semen and CD4 cell count in blood, differences in the biologic variability of viral RNA levels, and differences in the virus load response to antiretroviral therapy.
299 citations
TL;DR: Only recently have amplification methods been established to detect viruses in semen with high sensitivity and specificity, and it is unclear if these infections significantly contribute to male infertility.
Abstract: Bacterial and viral infections of the genital tract may be important aetiological factors for male infertility. Infectious processes may lead to deterioration of spermatogenesis, impairment of sperm function and/or obstruction of the seminal tract. Detection of bacteria in semen does not necessarily signify infection since bacteriospermia may represent contamination, colonization or infection. Reported prevalence of Ureaplasma urealyticum in human semen varies from 10 to 40%. Enterobacteria can even be found in up to 90% of semen samples depending on the sensitivity of detection methods used. Chlamydia trachomatis is the most frequent sexually transmitted bacterial organism in industrialized countries. It is suggested that its main influence is due to sexual transmission resulting in tubal disease and subsequent infertility in the female partner rather than a direct influence on male reproductive functions. The effect of leukocytospermia on male fertility is controversial. This is probably due to different detection methods, different populations studied and to the fact that leukocyte subtypes in semen may have different functions. In addition to potentially negative effects, leukocytes may even have protective effects on spermatozoa. Only recently have amplification methods been established to detect viruses in semen with high sensitivity and specificity. It is unclear if these infections significantly contribute to male infertility.
298 citations
TL;DR: The results suggest that when poor-quality semen samples are used for ICSI, there is a greater likelihood that some sperm selected for injection, despite appearing normal, contain fragmented DNA.
282 citations
01 Jan 1998
TL;DR: The chapter describes the traits, which determine male reproductive success in reptiles, and ongoing sexual selection on such traits arising from variance in mating success, and investigates which of these traits and selective events of reptiles qualify as particularly suitable research models.
Abstract: The chapter describes the traits, which determine male reproductive success in reptiles, and ongoing sexual selection on such traits arising from variance in mating success. It also investigates which of these traits and selective events of reptiles qualify as particularly suitable research models. It exemplifies the factors that determine the outcome of contests between males over sexual partners, and how females influence the outcome of male reproductive success by selecting a mating choice. The morphology of copulatory organs, time in coitus, and testis size may covary within, and differ between, reptilian groups. However, major importance for a male's probability of paternity, is how spermatozoa survive during prolonged storage in the female reproductive tract, and to what extent the seminal products and the chemical compounds produced by the female influence the motility of his spermatozoa within the female reproductive tract. In mammals, the intrauterine transport of semen may be rapid (minutes) and the ovulation occurs within hours or days, whereas in reptiles this transport is relatively slow and ovulation may not follow until weeks later.
271 citations
TL;DR: Genetics, management, and environmental factors clearly contribute to semen production in Holstein bulls and generally improved significantly with age of young bulls.
253 citations
TL;DR: A significant increase in the levels of ROS generated by samples prepared by swim-up from a washed pellet compared with spermatozoa isolated directly from seminal plasma is demonstrated and strategies should be developed for minimizing collateral DNA damage.
Abstract: Before the advent of intracytoplasmic sperm injection (ICSI) semen preparation techniques focused on the need to sustain the fertilizing potential of the spermatozoa particularly by reducing oxidative stress. However, for severely oligozoospermic patients treated by ICSI, sperm preparation protocols are used which aim to maximize sperm recovery rather than sperm function. In this study we have examined the impact of different sperm preparation techniques on oxidative stress, sperm motion and DNA integrity. Reactive oxygen species (ROS) generation was monitored using luminol-dependent chemiluminescence, seminal antioxidant activity was assessed using a total reactive antioxidant potential (TRAP) assay while sperm motility and DNA damage were evaluated using computer assisted semen analysis and in-situ nick translation respectively. The results demonstrate a significant increase in the levels of ROS generated by samples prepared by swim-up from a washed pellet compared with spermatozoa isolated directly from seminal plasma. This oxidative stress was associated with a highly significant increase in the level of DNA damage sustained by the spermatozoa while the quality of sperm motility remained largely unchanged. These results suggest that if repeated centifugation protocols are to be used to prepare spermatozoa, strategies should be developed for minimizing collateral DNA damage.
212 citations
TL;DR: It is concluded that, in addition to maintaining the fertilizing capacity of bull semen at levels comparable to those observed with standard freezing diluent, Biociphos plus also prevents microbiological contamination by bacteria or mycoplasma, both of which are generally present in the various commercially available sources of egg yolk.
TL;DR: The absence of genotypic changes consistent with protease inhibitor resistance in the semen, despite their presence in blood plasma, suggests the possibility of limited penetration of these agents into the male genital tract on incompletely suppressive antiretroviral therapy.
Abstract: Objectives: To evaluate blood and genital secretions from HIV-infected men for HIV-1 resistant to antiretroviral agents. Design: A longitudinal study of 11 men with HIV infection and persistent detectable HIV RNA levels in blood and semen on antiretroviral therapy. Methods: HIV-1 from the blood and seminal plasma, obtained before the initiation of a new therapeutic regimen and on therapy, were evaluated by population-based sequencing of reverse transcriptase (RT) and protease RNA for the development of resistance to antiretroviral therapy. The genetic relatedness of sequences over time was compared. Results: RT genotypic resistance markers were present in seminal plasma at baseline in three out of six individuals with previous RT inhibitor experience. Eight out of 10 men, from whom the viral sequence was available on new therapy, demonstrated the evolution of new resistance mutations in the blood or seminal plasma, or both. The evolution of resistance mutations in blood and semen were frequently discordant, although over time similar patterns were seen. In two individuals, protease inhibitor resistance mutations evolved in the blood but not in the major variant in seminal plasma. Comparisons of the viral sequences between blood and seminal plasma from six men revealed two patterns. Three men showed a clustering of sequences from blood and semen. Three had sequences that appeared to evolve separately in the two compartments. Conclusions: HIV-1 variants with genotypic resistance markers are present in the male genital tract and evolve over time on incompletely suppressive antiretroviral therapy. The absence of genotypic changes consistent with protease inhibitor resistance in the semen, despite their presence in blood plasma, suggests the possibility of limited penetration of these agents into the male genital tract. Sexual transmission of resistant variants may have a negative impact on treatment outcome in newly infected individuals and on the spread of the diseases within a population. Therapeutic strategies that fully suppress HIV-1 in the genital tract should be a public health priority.
TL;DR: It is suggested that the plasmalemma, the acrosome, and the mitochondria of unfrozen spermatozoa varied as to their functional status, while the cryopreservation process resulted in a more uniform status of sperm organelles.
Abstract: Flow cytometry was used to compare the functional status of fluorescently stained sperm organelles from 12 Holstein bulls after storage for 24 h at 5 degrees C and after cryopreservation. The organelle-specific stains, SYBR-14 and LysoTracker Green DND-26, identified spermatozoa with intact plasmalemma and those with intact acrosomes, respectively. The mitochondria-specific stain, 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolyl-carbocyan ine iodide (JC-1), identified two populations of spermatozoa. One population stained red-orange because the JC-1 accumulated in the mitochondria as aggregates (characteristic of cells exhibiting a high membrane potential); a second population stained green because of JC-1 monomers within the mitochondria (characteristic of cells exhibiting a lower membrane potential). Analysis of variance revealed that within bulls, the properties of sperm viability, intact acrosomes, and mitochondrial status differed in spermatozoa stored for 24 h (p 0.11). Linear regression analyses resulted in significant models in which the proportions of stained spermatozoa stored for 24 h were indicative of those proportions observed in the cryopreserved fractions. These findings suggest that the plasmalemma, the acrosome, and the mitochondria of unfrozen spermatozoa varied as to their functional status. The cryopreservation process, however, resulted in a more uniform status of sperm organelles.
TL;DR: It is unlikely that restriction of SI variants from the male genital tract accounts for the observed NSI transmission bias, and no evidence for a semen-specific signature amino acid sequence was detected.
Abstract: Genital secretions are the source of a majority of human immunodeficiency virus type 1 (HIV-1) infections. Culturable HIV-1 (23, 59) and proviral DNA (21, 37) have been detected in the nonspermatozoal mononuclear cell fraction of semen, which includes CD4+ lymphoid cells, monocytes, and macrophages (2, 54). Cell-free virions, measured as viral RNA, are also found in seminal fluid (20, 21, 37).
Heteroduplex tracking analyses of PCR-amplified HIV-1 env sequences from donor-recipient sexual transmission pairs revealed distinctions between viral variant populations in plasma, peripheral blood mononuclear cells (PBMC), seminal cells, and seminal fluid (62). In three of five cases, virus in semen mononuclear cells was the most closely related to that transmitted to the recipient, and hence these cells were implicated as a likely vehicle for transmission (62). Drug resistance mutations in HIV populations are also unequally distributed in the blood and semen (29). Genetic differences were also found between proviral variants in peripheral blood and those in genital secretions in one study of women infected with HIV-1 envelope sequence subtypes A and D (41). Distinctions between viral populations in other anatomical sites have also been noted (14, 24, 27).
Early following infection with envelope subtype B virus via homosexual or perinatal contact, intravenous drug use, and blood transfusion, individuals harbor viruses in their blood that are homogeneous over the V3 region of the envelope protein (8, 10, 30, 36, 39, 47, 57, 60, 61). V3 loop sequences are also relatively conserved between individuals early following infection and correspond to a macrophage-tropic or non-syncytium-inducing (NSI) signature sequence (6, 35, 47, 53, 60), despite the fact that the donor may harbor a highly differentiated virus population in the blood (56, 62). A simultaneously greater amount of viral genetic diversity has been reported in the gag gene at these early times (60, 61). This observation led to the hypothesis that selection may occur for the dissemination of a subset of variants with a particular envelope-mediated phenotype, possibly macrophage tropism. With the recognition of the existence of HIV coreceptors, this could also correspond to a tropism for coreceptors of the CC-chemokine receptor class or exclusion of the viruses that utilize CXCR-4 (1, 12, 13, 18). It is also possible that macrophage-tropic HIV variants are more likely to be found in, and thereby transmitted from, the genital compartment, since, in contrast to the balance in the blood, a greater number of monocytes and macrophages are found in semen (2, 54).
In contrast to other modes of transmission, complex HIV-1 envelope sequence populations have been reported in one study of recently seroconverting women heterosexually infected with subtype A or D (41). Sexual transmission from men requires infection of cells in or migrating to seminal fluid or cell-free transfer of virus to this compartment. A comparison of blood and semen viral populations may therefore indicate whether virus in the male genital tract commingles with that of blood or corresponds to a compartmentalized subset or distinct population of variants. In this report, we describe a cross-sectional study of proviral sequences in peripheral blood and nonspermatozoal semen cells from five HIV-1 subtype B-infected individuals. Strong evidence for nonrandom distribution of virus variants between the two compartments and of a more restricted founder population accounting for the semen provirus population was found in all three of the patients who also harbored virus with mutations characteristic of a syncytium-inducing (SI) viral genotype. However, no evidence was found for restriction of the SI genotype from the semen.
TL;DR: Tests for HIV-1 with the use of the polymerase chain reaction technique on the semen fraction obtained after washing appears to prevent infection in the inseminated woman.
TL;DR: It is established that the 26-kDa fertility-associated protein in bull seminal plasma is lipocalin-type PGD synthase, and it is speculated that this protein may play an important role in both the development and the maturation of sperm.
Abstract: The objective of this study was to characterize a 26-kDa seminal plasma protein previously shown to be prevalent in bulls of high fertility Spots of this protein, excised and electroeluted from two-dimensional SDS-PAGE gels, were used for N-terminal amino acid sequencing and for preparation of antiserum in rabbits The N-terminal amino acid sequence (ALQPNFEEDKFLGRWFTSGL) was 75% identical and 100% homologous to lipocalin-type prostaglandin (PG) D synthase isolated from human cerebrospinal fluid (CSF) Western blots of purified 26-kDa protein cross-reacted with polyclonal antibodies against lipocalin-type PGD synthase isolated from rat brain and human CSF Immunoreactive bands at 26 kDa appeared in Western blots of seminal plasma and cauda epididymal fluid (CEF) A 29-kDa band appeared in blots of rete testis fluid (RTF) PGD synthase activity was detected in seminal plasma, CEF, and RTF The cDNA for bovine lipocalin-type PGD synthase, isolated by reverse transcription-polymerase chain reaction, contained a coding region of 573 base pairs corresponding to 191 amino acids The amino acid sequence was 63-80% identical to that of the enzyme of other mammals These results establish that the 26-kDa fertility-associated protein in bull seminal plasma is lipocalin-type PGD synthase Although we do not yet know the role of lipocalin-type PGD synthase in the male genital tract, we speculate that this protein may play an important role in both the development and the maturation of sperm
TL;DR: The results suggest that the combined analysis of sperm linear-motility patterns, swim-up separated sperm motility and absolute ZBA can provide a valuable assessment of the fertilizing capacity of AI bull semen.
Abstract: The present study examined the relationship between bull sperm characteristics immediately post-thaw and some characteristics registered after swim-up, including the ability of spermatozoa to bind to homologous zona pellucidae (ZP) in vitro, and fertility after artificial insemination (AI) of 9426 females. Frozen-thawed semen from 22 AI bulls of the Swedish Red and White Breed, represented by 43 different frozen batches (1-4 batches/bull, 2 consecutive ejaculates/batch), was examined with the aim of determining concentration, motility patterns, morphology and membrane integrity. In addition, the frozen-thawed spermatozoa were subjected to a swim-up procedure and those separated in this way were tested with two assays of sperm-binding to the ZP of homologous oocytes in vitro (ZBA), using either a relative ZBA index against a control bull of proven high fertility or absolute binding (Absolute ZBA). The correlations of the various sperm traits and 56-day non-return rates (NRR) after field AI were retrospectively examined as single traits and as combinations of traits (combined measures), including regression analysis of significant traits. Among the sperm characteristics, positively significant (p < 0.01) correlations with NRR were found for linear motility post-thawing (r = 0.45-0.59) and the concentration of motile spermatozoa after swim-up (r = 0.43-0.63). Results obtained with the absolute ZBA approach were significantly (p < 0.05) correlated with NRR (r = 0.50), whereas the correlation between NRR and the ZBA index was not significant. The use of combined measures of sperm traits, including the ability to bind to ZP, showed a stronger predictive correlation with NRR (r = 0.68-0.75), compared with single traits. The results suggest that the combined analysis of sperm linear-motility patterns, swim-up separated sperm motility and absolute ZBA can provide a valuable assessment of the fertilizing capacity of AI bull semen.
TL;DR: A positive correlation was found between immature spermatozoa, as evaluation by PI staining, and cells with depolarized mitochondria, as evaluated by JC-1 staining; suggesting that spermutozoa defective for nuclear maturity could be functionally defective cells.
TL;DR: It is concluded that in severe asthenozoospermia, ultrastructural examination of spermatozoa has an effective prognostic value, identifying two syndromes with very different flagellar alterations and fertility potentials.
Abstract: An ultrastructural study of spermatozoa in a series of 247 severely asthenozoospermic patients disclosed two kinds of anomalies. The first was dysplasia of the fibrous sheath, a primary defect of spermatozoa with hypertrophy and hyperplasia of the fibrous sheath, associated axonemal anomalies, familial incidence and chronic respiratory disease. The patients could be divided into two subgroups: the complete form (all spermatozoa affected) and the incomplete form (alterations in 70-80% spermatozoa). There were no spontaneous or in-vitro fertilization (IVF) pregnancies. Intracytoplasmic sperm injection (ICSI) in six patients resulted in successful fertilizations, but only two pregnancies were obtained. These features configure a phenotype that suggests a genetic origin. The second anomaly was non-specific flagellar anomaly (NSFA), random secondary flagellar alterations affecting variable numbers of spermatozoa, without respiratory disease or familial incidence. 54 men with NSFA were followed for 2-6. years. Of these, 18 achieved conception, either spontaneous or by means of assisted fertilization, followed by 14 pregnancies and 12 live births. Their sperm motility significantly increased during the follow-up period. In the remaining 36 men motility did not change during the follow-up period and there were no fertilizations or pregnancies. We conclude that in severe asthenozoospermia, ultrastructural examination of spermatozoa has an effective prognostic value, identifying two syndromes with very different flagellar alterations and fertility potentials.
TL;DR: The most sensitive sperm : ova ratio for monitoring pollutant effects on fertilization success was 1500 : 1, which corresponds to half the minimal amount that yields a high fertilization rate in artificial insemination.
Abstract: The optimal ratio of spermatozoa : egg (15 000 : 1) for artificial insemination of African catfish Clarias gariepinus gave fertilization and hatching rates of 80 and 67%, respectively. Below a sperm : ova of 3000 : 1 fertilization success decreased significantly. Excessive sperm (>15 000 : 1) partly inhibited fertilization success. Sperm motility was decreased significantly by 0·001 mg 1−1 Hg2+ as HgCl2, but its effect on fertilization was dependent on the sperm : ova ratio, since excess sperm masked the effect of the pollutant. The most sensitive sperm : ova ratio for monitoring pollutant effects on fertilization success was 1500 : 1, which corresponds to half the minimal amount that yields a high fertilization rate in artificial insemination. There was a good correlation between fertilization and hatching rates (r=0·83; P<0·05). Although both fertilization and hatching rates provide equally good indicators of fertilization success, the more rapid fertilization rate test is recommended since it requires only 12 h.
TL;DR: The data demonstrate that, contrary to previous recommendations, infertile men with azoospermia and high FSH values should be reconsidered for testicular biopsy, provided that tissue samples can be cryopreserved for later TESE/ICSI treatment.
Abstract: Spermatozoa recovered from testicular biopsies can be used through intracytoplasmic sperm injection (ICSI) to achieve a pregnancy. To assess the likelihood of successful testicular sperm extraction (TESE) in men suffering from severe oligo- or azoospermia, bilateral biopsy specimens were obtained. Following semi-thin sectioning, the morphology of testicular samples was graded according to a modified Johnsen score. TESE was performed in parallel to this histological examination. The number of isolated spermatozoa was assessed in a semiquantitative way. From 103 patients investigated, 64 (62.1%) showed azoospermia in a preceding semen analysis and 29 (28.2%) patients had sperm concentrations between 0.1 and 1 x 10(6)/ml. In 10 patients who had higher sperm counts, most spermatozoa were non-motile. Spermatozoa could be detected after TESE in the testicular tissue of 49 (77%) azoospermic men. When follicle stimulating hormone (FSH) concentration was normal, most patients had detectable spermatozoa after TESE. Nearly one-third of patients with mildly elevated FSH had no spermatozoa. Thirty-nine percent of patients in whom FSH was elevated to more than twice normal and 50% of patients with grossly elevated FSH had no detectable spermatozoa. In all, 82.8% of men with sperm concentrations between 0.1 and 1x10(6)/ml in their ejaculate showed spermatozoa in the tissue sample after TESE. Our data demonstrate that, contrary to previous recommendations, infertile men with azoospermia and high FSH values should be reconsidered for testicular biopsy, provided that tissue samples can be cryopreserved for later TESE/ICSI treatment.
TL;DR: The role played by environmental factors, such as ions, in the activation of sperm motility and metabolism of different species of invertebrates and vertebrates is reviewed.
Abstract: In most species, once formed in the testis, spermatozoa are bathed in a fluid where they remained immobile and with a very low level of metabolism. This immotile status is understandable in view of the need to preserve the sperm energy reserve and to decrease the risk of alteration to membranes, internal structures and biochemical compounds by endogenous oxidizing agents produced by mitochondrial activity. This quiescent phase can be of different lengths and finishes when the semen is released into the external environment where the spermatozoa become motile and metabolically active. For invertebrates, and some fish, sexual activity is generally seasonal and fertilization is external. Spermatozoa, once differentiated in the gonad, remain there completely quiescent until they are released into the external medium, which is either fresh water or sea water. Dilution of the testicular fluid surrounding the spermatozoa allows the initiation of motility and metabolism. In fact, this seminal fluid has an inhibitory effect on sperm activity. For birds and mammals (including humans), the situation is much more complex. In these species, sperm production is almost continuous although for some of them, seasonal variations occur. When spermatozoa are released from the Sertoli cells, they are rapidly exported from the testis to the epididymis where the composition of the surrounding medium is profoundly modified. For most species, the spermatozoa remain immobile in the lower part of the epididymis, even though they have gained the capability to be fully motile as shown by dilution in an adequate medium. In vivo, motility is activated when the spermatozoa are mixed with secretions from the different accessory glands during ejaculation. This paper will review the role played by environmental factors, such as ions, in the activation of sperm motility and metabolism of different species of invertebrates and vertebrates. Special attention is given to changes in sperm internal pH, its regulation and role in the activation of sperm axonemal movement.
TL;DR: The laboratory evaluation of semen collected during the period of breeding indicated effects of boar on ejaculate volume, total number of sperm per ejaculate, motility, and the percentage of sperm with normal morphology, indicating that morphological characteristics are a useful measure of semen quality.
Abstract: The reliability of using different in vitro-derived measures of sperm quality to predict boar fertility was examined. On three occasions during a 20-wk period of breeding, special collections of the first sperm-rich fraction of the ejaculate from six boars were carried out. After in vitro capacitation procedures, three dilutions (5 x 10(5), 1.25 x 10(5), and 3.125 x 10(4) sperm/mL) of these semen samples were used in a standardized in vitro fertilization (IVF) test with oocytes recovered from prepubertal slaughterhouse ovaries and matured in vitro. Routine assessments of sperm motility, concentration, and morphology were also carried out for all collections used for AI during the 20-wk period. Semen from the same ejaculate, processed according to normal commercial practice using the AndroHEP extender, was used to inseminate equal numbers of recently weaned sows with either 3 x 10(9) or 2 x 10(9) total sperm, three times during the estrous period. Data from a total of 444 sows were used to determine boar fertility; between 12 and 54 sows were bred with each semen dose across the six boars. All measures of sperm fertilizing ability in vitro were different among boars (all P < .05) and use of different semen dilutions for IVF allowed further discrimination of apparent sperm quality among boars. The laboratory evaluation of semen collected during the period of breeding indicated effects of boar on ejaculate volume, total number of sperm per ejaculate, motility, and the percentage of sperm with normal morphology (all P < .01). Sperm dose used in AI had no effect on farrowing rate (80.7 vs 81.5%), but the lower AI dose resulted in a reduction (P < .05) in total numbers born (10.8 vs 10.0). For all three semen dilutions, estimated potential embryo production rate accounted for up to 70% of the variation in litter size obtained with 3 x 10(9) sperm per AI dose, and the number of sperm attached per oocyte was a major factor accounting for variation in litter size obtained with 2 x 10(9) sperm per AI dose. These IVF variables may, therefore, be effective indicators of boar sperm quality for use in AI. With 2 x 10(9) sperm per AI dose, the percentage of sperm with normal morphology also explained a large part of the variance in litter size born (R2 = .59), indicating that morphological characteristics are a useful measure of semen quality.
TL;DR: Serum and semen from 90 anti-HCV-positive drug users were tested for HCV and HGV/GBV-C RNAs by polymerase chain reaction (PCR) assay, hybridization, and sequence analysis and results agree with the low risk of sexual transfer of HCV.
Abstract: The identification of hepatitis C virus (HCV) in semen remains controversial and that of hepatitis G virus (HGV) or GB virus C (GBV-C) has never been investigated. Serum and semen from 90 anti-HCV-positive drug users were tested (27 infected with HIV) for HCV and HGV/GBV-C RNAs by polymerase chain reaction (PCR) assay, hybridization, and sequence analysis. Semen was processed into round cells, seminal plasma, and spermatozoa. Fifty-six patients were HCV-viremic, but HCV-RNA was not identified in their seminal fractions. However, PCR inhibitors were found in the semen of 34 of these men. Twenty-eight patients had HGV/GBV-C RNA in their blood and for 24 of them, ejaculates were available for analysis. HGV/GBV-C RNA was found in the seminal plasma of 6 of 12 samples free from PCR inhibitors. These results agree with the low risk of sexual transfer of HCV and provide preliminary evidence for the presence of HGV/GBV-C in semen.
TL;DR: The processes leading to hyperactivation and to the membrane changes associated with capacitation are not tightly interlinked and this finding is considered to be due to hyperactivated motility being associated with flagellar movement, while the CTC assay assesses changes in the Ca2+ levels of the sperm head plasma membrane.
Abstract: While hyperactivated motility is known to be a concomitant of capacitation, and a prerequisite for fertilization, the specific interdependence of capacitation and hyperactivation in human spermatozoa has not been investigated. This study was designed to determine the effect of seminal plasma contamination on the expression of hyperactivated motility and the relationship between hyperactivation and capacitation, since seminal plasma contains decapacitation factor(s). Seminal plasma was obtained by centrifugation of aliquots of liquefied semen layered over 1.5 ml 40.5% Percoll and mixed with human tubal fluid (HTF) medium containing 30 mg/ml human serum albumin (HSA) (HTF) to a final concentration of 5% (v/v) seminal plasma (SP). Motile spermatozoa were isolated from the remainder of the semen by swim-up into either HTF or SP medium. Samples were taken from each treatment immediately post-harvest (0 h) and after 60 min at 37 degrees C (1 h) for hyperactivation and capacitation assessment. The treatments were then divided into two portions, centrifuged and resuspended in either HTF or SP, giving HTF control and SP control treatments and two crossover treatments, 1 h HTF then 1 h SP (H/SP) and 1 h SP then 1 h HTF (SP/H). All tubes were incubated for a further 60 min at 37 degrees C before aliquots were taken for hyperactivation and capacitation assessments. Hyperactivation was estimated using an IVOS v10.6t (Hamilton Thorne Research, Beverly, MA, USA) 60 Hz CASA instrument, and capacitation was estimated using the chlortetracycline (CTC) method. The presence of seminal plasma in the capacitation medium for 60-120 min post-swim-up inhibited the development of hyperactivated motility. This inhibition was reversible, and was not prevented by preincubation for 1 h in HTF medium. There was no difference in the CTC binding patterns between treatments at 2 h, indicating that the capacitation-associated membrane changes were not affected by the presence of a low concentration of seminal plasma. There was no correlation between percentage capacitated and percentage hyperactivated spermatozoa for any treatment. Since the proportions of hyperactivated spermatozoa and capacitated spermatozoa were not related, we conclude that the processes leading to hyperactivation and to the membrane changes associated with capacitation are not tightly interlinked and consider this finding to be due to hyperactivated motility being associated with flagellar movement, while the CTC assay assesses changes in the Ca2+ levels of the sperm head plasma membrane.
TL;DR: It is concluded that morphologically abnormal spermatozoa are excluded from the accessory sperm population based upon severity of head shape distortion.
TL;DR: Computer-assisted sperm-motion analysis was used to determine the effects of IGF-I and IGF-II on bovine sperm motility parameters, and it was found that both IGFs increased sperm Motility and straight-line velocity relative to the control.
Abstract: Insulin-like growth factor I (IGF-I) has been identified in human seminal plasma. This study was conducted to determine whether IGF-I is present in bovine seminal plasma, whether sperm cells express the IGF-I receptor (IGF-IR), and whether IGF-I affects sperm motility. Semen samples were collected from bulls by electroejaculation and maintained at 378C, and motility of sperm was assessed. After centrifugation to separate sperm cells from seminal plasma, the seminal plasma was submitted to a validated heterologous RIA for IGF-I. Significant concentrations of IGF-I (116.29 6 40.83 ng/ml expressed as mean 6 SD) were measured in bovine seminal plasma. Sperm cells were washed with buffer and subjected to either radioreceptor assay (RRA) or immunocytochemistry (IC). RRA revealed a single high affinity for the IGF-IR with a Kd of 0.83 nM as determined by the computer program LIGAND. IC, using three monoclonal antibodies, localized the IGF-IR to the acrosomal region of the sperm. Computer-assisted sperm-motion analysis was used to determine the effects of IGF-I and IGF-II on bovine sperm motility parameters. Both IGF-I and IGF-II increased sperm motility and straight-line velocity (p , 0.05) relative to the control. The presence of IGF-IR on sperm, the presence of IGF-I in semen, and the ability of IGF-I to stimulate sperm motility provide evidence that the IGF system may be involved in the fertilization process in the bovine species.
TL;DR: The specific localization of eNOS to human spermatozoa suggests that nitric oxide may be involved in normal sperm physiology, however, aberrant patterns of sperm eNos expression are associated with decreased sperm motility, possibly through the generation of excessive cytotoxic oxidants.
TL;DR: The data suggest that saliva may be more important than semen or stool in the sexual transmission of HHV-8, and raises the question as to why there is no evidence for bloodborne virus transmission.
Abstract: Human herpesvirus 8 (HHV-8) has been proposed as a sexually transmitted etiologic agent of Kaposi’s sarcoma (KS). In this study, by use of a sensitive polymerase chain reaction assay, HHV-8 DNA was detected in the skin lesions (92%), normal skin (23%), peripheral blood mononuclear cells (PBMC) (46%), plasma (7%), saliva (37%), and semen (12%) but not stool samples from KS patients. The average number of HHV-8 copies per microgram of positive target DNA was 64,000, 9000, 40, 33,000, and 300 for skin, PBMC, plasma, saliva, and semen samples, respectively. Only 1 non-KS donor sample, of saliva, was positive for HHV-8. Sequencing showed 5% divergence among HHV-8 strains. The data suggest that saliva may be more important than semen or stool in the sexual transmission of HHV-8. The relatively high prevalence of HHV-8 in PBMC raises the question as to why there is no evidence for bloodborne virus transmission. Kaposi’s sarcoma (KS) occurs as a mild indolent disease in immunocompetent persons but is an aggressive, lethal disease in immunosuppressed patients, particularly those infected with human immunodeficiency virus (HIV) [1]. Epidemiologic studies suggest that KS is a sexually transmitted disease caused by the newly discovered human herpesvirus 8 (HHV-8) [1, 2]. Subsequently, HHV-8 has been shown to be associated with numerous other tumors, including body cavity lymphomas, angiosarcomas and hemangiomas, premalignant Bowen’s disease, malignant squamous cell carcinomas, and actinic keratosis [2]. HHV-8 positivity has been shown to be more closely linked to HIV-positive patients with homosexuality or bisexuality as their major risk factor for HIV than to patients with other risks [2]. Hence, it has been suggested that HHV-8 may be a sexually transmissible virus, particularly via anal intercourse. The fact that HHV-8 can be found in semen samples and in individual spermatozoa and mononuclear cells present in semen has supported this hypothesis [3]. However, in large-scale or smaller matched studies, the prevalence of HHV-8 in semen has been equal to or less than that found in peripheral blood mono
TL;DR: Aluminium may be one of the environmental pollutants causing impaired semen quality and a high concentration of aluminium in spermatozoa was correlated with decreased sperm motility.
Abstract: Aluminium, cadmium and lead concentrations in the spermatozoa and seminal plasma of 27 employees of two industrial companies, a refinery and a polyolefin factory, and 45 consecutive sperm donor candidates at a sperm bank were studied using atomic absorption measurements. The relationship between metal concentration and parameters of semen analysis was studied. A high concentration of aluminium in spermatozoa was correlated with decreased sperm motility. The concentrations of cadmium and lead were low and did not show any correlation with parameters of semen analysis. Aluminium may be one of the environmental pollutants causing impaired semen quality. The mean sperm concentrations were similar in the factory employees (96 x 10 6 /ml), in the sperm donor candidates of the comparison group (104 x 10 6 /ml) and in 352 donor candidates at the sperm bank of the Family Federation of Finland (107 x 10 6 /ml) between May 1993 and May 1995.