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At least 109 records · Page 6Linked to original sources
PubMed2000

Extracellular presence of reactive oxygen species (ROS) in fresh and frozen-thawed canine semen and their effects on some semen parameters.

The objective of this study was to determine the presence of reactive oxygen species (ROS), especially superoxide anion (O2-), in fresh and frozen-thawed canine semen, its effect on other seminal parameters and whether the freezing-thawing process influences the O2- production rate. A total of 56 mature male domestic dogs were used in this study. Their semen was examined before and after freezing-thawing process. Sperm motility, hypo-osmotic swelling, sperm morphology and O2- extracellular production were measured. The dogs were divided in two groups, with the criterion of the absence or presence of O2- in fresh semen (groups A and B, respectively). Values of group A were compared with the respective values of group B. A significant decrease in motility and percentage of swollen spermatozoa and an increase in morphological abnormalities and O2- production in group B were found in comparison with group A after freezing-thawing process (p < 0.05). It seems that the freezing-thawing process leads to an increase of the O2- production. However, it remains to be documented if the increased concentrations of O2- in canine semen are responsible for the alterations in the seminal parameters observed in this study.

Animals↗
PubMed1991

Cryopreservation of boar semen. II: Effect of cooling rate and duration of freezing point plateau on boar semen frozen in mini- and maxi-straws and plastic bags.

The post-thaw motility and the acrosome integrity of semen from 4 boars frozen with a programmable freezing machine, in mini (0.25 ml) and maxi (5 ml) plastic straws and in 10 x 5 cm Teflon FEP-plastic bags (0.12 mm thick, 5 ml), were compared. The freezing of the semen was monitored by way of thermo-couples placed in the straws and the bags. Three freezing programmes were used, namely A: from +5 degrees C, at a rate of 3 degrees C/min, to -6 degrees C, held for 1 min at -6 degrees C, and followed by a cooling rate of 20 degrees C/min to -100 degrees C; B: a similar curve except that there was no holding time at -6 degrees C and that the cooling rate was 30 degrees C/min, and C: from +5 degrees C to -100 degrees C, with a cooling rate of 35 degrees C/min, followed by storage in liquid N2. Despite the freezing curve assayed, both the mini-straws and the bags depicted much shorter freezing point plateaus as compared to the maxi-straws. Post-thaw sperm motility as well as the amount of normal apical ridges were equally significantly higher when semen was frozen in mini-straws or in bags than in maxi-straws. Significant differences in these post-thawing parameters were obtained between the freezing curves used. The stepwise freezing procedure A appeared as the best alternative for boar semen, considering this in vitro evaluation.

Acrosome↗
PubMed2002

Concordance between semen-derived HIV-1 proviral DNA and viral RNA hypervariable region 3 (V3) envelope sequences in cases where semen populations are distinct from those present in blood.

Sequence analysis of the third hypervariable region (V3) of the envelope gene of the HIV-1 was carried out on HIV proviral and viral populations present in blood and semen. Phylogenetically distinct populations of virus were observed in three of the 10 patients analysed. Although the majority of the viruses were predicted to have an R5 phenotype, amino acid differences between blood and semen-derived virus and provirus sequences were observed at sites previously shown to affect cell tropism. Importantly, the semen proviral population was representative of that observed for cell-free virus. This indicates that seminal fluid mononuclear cells are possible sources for the cell-free virus in found in semen.

Amino Acid Sequence↗
PubMed1997

Presence of 11 beta-hydroxysteroid dehydrogenase in human semen: evidence of correlation with semen characteristics.

11 beta-hydroxysteroid dehydrogenase (11 beta-HSD), the enzyme that catalyzes the conversion of biologically active glucocorticoids to their inactive metabolites, was shown to be located exclusively in Leydig cells of the rat testis, and its appearance was associated with the developmental rise in testosterone. Thus, 11 beta-HSD was suggested to play an important role in maintaining steroidogenesis by inactivating excess cortisol that inhibits testosterone production. Whether equivalent protection from glucocorticoids excess is necessary for spermatogenesis is not known, and we have, accordingly, investigated the 11 beta-HSD activity in ejaculated human semen. Both 11 beta-dehydrogenase (11 beta-DH) and 11 beta-oxoreductase (11-OR) activities of 11 beta-HSD were measurable in semen, although seminal plasma was devoid of 11 beta-HSD activity. Azoospermic specimens were associated with low 11 beta-dehydrogenase activity, indicating the presence of enzyme activity in cells other than spermatozoa. Pure spermatozoa separated on percoll gradient could oxidize corticosterone in the presence of NAD or NADP. Significantly higher 11 beta-DH activity is associated with semen specimens with low sperm count (p < .05) and higher level of morphologically abnormal spermatozoa (p < .05). The presence of 11 beta-HSD in human semen and its association with sperm characteristics thus suggests functional role for glucocorticoid exclusion in the sperm maturation process.

11-beta-Hydroxysteroid Dehydrogenases↗
PubMed1997

Semen parameters in a fertile versus subfertile population: a need for change in the interpretation of semen testing.

This prospectively designed study was conducted to compare a fertile and a subfertile population so as to define normal values for different semen parameters. Semen analyses were performed according to the World Health Organization (WHO) guidelines, except for sperm morphology (strict criteria). In the fertile population (n = 144), all patients had recently achieved pregnancy, within 12 months of unprotected coitus. As subfertile controls we examined semen samples from 143 consecutive men attending our infertility clinic during the same study period. Couples with tubal factor infertility and/or ovulatory disorders were excluded from our study. Using receiver operating characteristic (ROC) curve analysis we determined the diagnostic potential and cut-off values for single and combined sperm parameters. Sperm morphology scored best, with a value of 78% (area under the ROC curve). Summary statistics showed a shift towards abnormality for most semen parameters in the subfertile population. Using the 10th percentile of the fertile population as the cut-off value, the following results were obtained: 14.3 x 10(6)/ml for sperm concentration, 28% for progressive motility and 5% for sperm morphology. Using ROC analysis, cut-off values were 34 x 10(6)/ml, 45% and 10% respectively. Cut-off values for normality were different from those described in the WHO guidelines. Routine bacterial and non-bacterial cultures turned out to be of little prognostic value.

Adult↗
PubMedDate not supplied

Comparison of semen analysis between the two Hamilton-Thorn semen analysers.

This study was designed to assess the reproducibility of the computer-assisted semen analysis (CASA) system. Semen specimens from 41 suspected subfertile patients were analysed on two identical Hamilton-Thorn Motility analysers (HTM, model 2030, version 7). Specimens were analysed after liquefaction at 37 degrees C for 30 min on two HTMs adjusted to the same gate settings and by using the same semen droplet loaded on a Makler counting chamber prewarmed at 37 degrees C. Significant differences were seen in the total sperm count (P < 0.0004), motile sperm count (P < 0.004), amplitude of lateral head displacement (P < 0.0001), linearity (P < 0.01), and beat cross frequency (P < 0.0001) between the two HTMs. No significant differences between the two machines was seen in the case of other sperm motion parameters: percentage motility, average path velocity, straightline velocity, curvilinear velocity, straightness, and progressive motility. Our results indicate that the reproducibility of several semen parameters analysed by HTM is poor, and steps to remedy this problem are necessary.

Autoanalysis↗
PubMed1997

Semen characteristics in HIV-1 positive men and the effect of semen washing.

We have undertaken an analysis of semen from HIV infected men with regard to sperm counts and motility, non-spermatozoal cells, and viral nucleic acid. Regression analysis showed that sperm concentration and motility were positively associated with blood CD4 cell count. By contrast, non-spermatozoal cell concentration (round cells) was inversely related to CD4 count. Extracellular HIV RNA was detected in the majority of semen samples and proviral DNA in a minority. Percoll gradient washing of 12 semen samples yielded six samples containing adequate sperm concentration for analysis. This washing procedure reduced prewash extracellular RNA to below detectable limits in all cases; proviral DNA present in two of the six prewash samples was also reduced to below detectable limits after washing. We conclude that semen washing before artificial insemination may reduce the risk of HIV transmission from an infected man to an uninfected woman. However, further evidence from prospective analyses of such an approach is required.

CD4 Lymphocyte Count↗
PubMed1977

Oestrogen content of semen and the effect of exogenous oestradiol-17beta on the oestrogen and androgen concentration in semen and blood plasma of bulls.

The concentration (mean +/- S.E.M.) of oestrogen in semen (0-89 +/- 0-04 ng/ml) of bulls was 8-9-fold higher than in blood plasma (0-10 +/- 0-01 ng/ml) while the concentration of androgen in semen (1-15 +/- 0-26 ng/ml) was 2-7-fold lower than in blood plasma (3-21 +/- 0-47 ng/ml). This concentration of oestrogen in semen was not influenced by 0,1,3 or 5 false mounts or when ejaculations occurred at 2-min intervals. When 100 mg oestradiol-17beta were injected i.v. the oestrogen level in semen followed that in the plasma.

Androgens↗
PubMed2002

Management of the female stimulus during semen collection and its association with libido re-establishment and semen characteristics of goats.

The effect of management of the female stimulus during semen collection and its association with libido re-establishment and the semen characteristics of sexually mature goats was evaluated. Eight 2-yr-old bucks were individually subjected to 12 weekly trials in which one of the following three treatments was applied alternately. In treatment one, each male performed two ejaculations on an estrus-induced, restrained doe and semen was collected with an artificial vagina (AV). In treatment two, males were collected as in the former treatment, but a different doe served as the stimulus female for the second ejaculation. In treatment three, two restrained does were present while collecting each buck, allowing males to choose which female to mount and serve in each of the two collections. Number of mounts before first ejaculation and reaction times (period from introduction of the ram to the test arena to his first ejaculation) were similar among treatments (P > 0.05). A significant (P < 0.05) decrease was found for number of mounts performed before achieving the second ejaculation and for latency between ejaculations in the third treatment. No differences (P > 0.05) were found for semen volume (0.8+/-0.03, 1.0+/-0.03, and 0.9+/-0.02 mL) or sperm concentration (4.4+/-0.15, 4.6+/-0.13, and 4.4+/-0.86 spermatozoa/mL) among the three treatments or between the first and second collection. However, a trend to decrease volume and concentration was observed. It was concluded that the simultaneous presence of two females while bucks are collected reduced the number of mounts performed before the second ejaculation and the latency between ejaculations.

Animals↗
PubMedDate not supplied

Alteration of semen characteristics and regulatory factors in human semen with bacterial infection.

Semen samples (n = 40) obtained from males attending an infertility clinic were subjected to bacteriological culture and categorized as bacteriologically negative (group I) and bacteriologically positive (group II) depending on the culture positivity. Semen samples from both groups were simultaneously analyzed for routine parameters such as volume, count, motility, viability, morphology, pH, and hypoosmotic swelling. Seminal plasma was assayed for levels of prolactin (PRL), prolactin-suppressing factor (PSF), prostatic inhibin peptide (PIP) and zinc (Zn). Patients in group II (n = 25) showed statistically significant alteration (p < .01) in semen parameters such as motility, percent normal morphological forms, and percent normal HOS test as compared to group I (n = 15). There was a negligible change in the sperm concentration between the two groups. The semen volume, viability, and pH did not show any variation. Among the regulatory factors assayed, there was a significant change in the Zn, PSF (p < .05), and PIP (p = .01), while no such alterations were seen for PRL. The results suggest that bacterial infection affects fertility either by affecting the seminal characteristics directly or by acting on the regulatory systems.

Bacterial Infections↗
PubMed1978

Comparison of two procedures for freezing semen from cocks of high and low fertility with frozen semen.

Semen samples from groups of males chosen for high or low freezability of semen were frozen by two different methods, one using glycerol as the cryoprotectant and the other using DMSO. Fertilizing capacity was highest from semen collected from males of the high group and frozen in the presence of DMSO. Neither semen source nor method of freezing had any influence on the hatch of fertile eggs.

Animals↗
PubMedDate not supplied

Variation in semen parameters derived from computer-aided semen analysis, within donors and between donors.

The development of computer-aided semen analysis (CASA) has made it possible to study sperm motility characteristics objectively and longitudinally. In this 2-year study of 8 sperm donors, we used CASA to measure 7 semen parameters (concentration, percentage of motile spermatozoa, curvilinear velocity, average path velocity, straight-line velocity, amplitude of lateral head displacement, and beat/cross frequency). The frequency distributions of the 7 parameters in the semen samples of each donor were investigated. All parameters but one were normally distributed; concentration was distributed log-normally. Variation within individual donors and between donors was studied. Analysis of variance demonstrated that variation between donors was not explained by the longitudinal variation within individual donors. Variations in motility characteristics between donors were substantial, which may make motility characteristics of limited value as a tool for establishing fertility. Strong correlations were found between the 7 parameters, partly because by definition, motility characteristics are interdependent. Fisher's discriminant analysis demonstrated that each donor appeared to have his own set of semen characteristics and, more specifically, his own motility signature. From this data set it can be predicted that in order to find population means among sperm, it may be more efficient to measure more subjects than to increase the number of samples per subject.

Humans↗
PubMed1983

Has the fertility of Danish men declined through the years in terms of semen quality? A comparison of semen qualities between 1952 and 1972.

The semen analysis of 1,077 men examined in 1952 was compared with the semen analysis of 1,000 men examined in 1972 in order to assess if fertility in Danish men has declined during the period. The men on both occasions were examined because of a fertility problem. In 1952 6.2% of the men had azoospermia compared with 3.9% in 1972 (P less than 0.05). Between 1952 and 1972 there was a fall in sperm count (P less than 0.01, median 73.4, and 54.5 mill/ml), a deterioration in spermatozoa motility (P less than 0.001), an increase in number of abnormal spermatozoa (P less than 0.01, median 26.0%, and 44.8%), and a deterioration in fertility class according to the Hammen system (P less than 0.001). Semen volume and number of immobile spermatozoa did not change. This study of Danish men, like studies from other industrialized countries, indicates a fall in semen quality and male fertility since the early fifties.

Adult↗
PubMed2000

The relationship between semen quality and mineral composition of semen in various ram breeds.

Semen was collected during the breeding season from rams by electroejaculation from two native (13 Najdi and 8 Naemi) and three imported (6 Merino, 7 Somalian and 9 Sudanese) sheep breeds. There was a marked reduction in sperm concentration and the percentage live spermatozoa (p<0.01) produced by the Somalian (Barbari) and Sudanese (Sawakni) breeds. On the other hand, these two breeds showed the highest percentage of spermatozoal individual motility (p<0.05) and the highest concentrations of sodium (Na) chloride (Cl) and inorganic phosphorus (P) in the whole semen, seminal plasma and spermatozoa. Superior sperm density, percentage live spermatozoa and seminal concentrations of potassium (K) and calcium (Ca) were evidenced in the Najdi, Naemi and to a lesser extent, in the Merino rams. The biological effects of these inorganic constituents, together with magnesium (Mg), in the semen on semen quality should be considered in the interpretation of the results obtained in the fertility evaluation of the various ram breeds.

Journal Article↗
PubMedDate not supplied

The application of a simple RIA technique for the detection of 19-OH F1 alpha/F2 alpha prostaglandin, a specific semen marker, in semen contaminated vaginal swabs: time since intercourse studies.

The specificity of the 19-OH F1 alpha/F2 alpha prostaglandin antisera for the detection of semen in seminal/vaginal mixtures, has been evaluated. Using a parallel curve test we found that the antibody showed a high specificity for these seminal prostaglandins in seminal/vaginal mixtures at concentrations of between 2 pg and 40 pg/100 microliter. The precision of the assay has been improved by the use of a donkey-anti-rabbit ferritin-bound second antibody. The application of this detection system makes it possible to complete an assay within 4.5 h. A survey of 50 semen-free vaginal swabs obtained from 3 donors, taken throughout the menstrual cycle, showed no trace of these prostaglandins. They were also not detected in the vaginal secretions of two further donors who were undergoing medication. Using only 10-microliter aliquots of a seminal/vaginal swab extract, prepared in 500 microliter, it was possible to detect semen up to approx. 80 h after one sexual act.

Antibody Specificity↗
PubMed1975

The semen of fertile men. II. Semen characteristics of 100 fertile men.

From a population of men applying for voluntary sterilization, 100 consecutive cases were selected according to the following criteria: (1) each man had fathered at least two children; (2) at the time of the request for a vasectomy the man's wife was pregnant; and (3) a complete prevasectomy semen analysis, including sperm morphology, was available. The usual parameters of human semen evaluation are reported: the mean volume of the ejaculates was 3.3 ml +/- 0.84 SD (range, 0.5 to 11 ml); the mean sperm density was 81 million/ml +/- 57 SD (range, 4 to 318); while the geometric mean, which according to the sample distribution is more representative, was 68. The mean percentage of motile sperm was 63% +/- 16 SD (range, 10 to 95%); the grade of forward progression was 3 +/- 0.55 SD (range, 2 to 4); and for sperm morphology the mean number of sperm with oval heads was 75% +/- 6 SD (range, 21 to 90%). Statistical comparison of these findings with those of our previous study of the semen of 1300 fertile men revealed complete agreement; minor statistical differences, on single parameters, with three similar studies are indicated. A positive relationship between the different variables, sperm density and sperm motility (in percentage of motile sperm and degree of forward motion), as well as between the two variables of sperm motility and sperm morphology to the other variables was confirmed.

Adult↗
PubMed1987

Computerized semen analysis: objective measurement of semen characteristics is biased by subjective parameter setting.

To test the influence of parameter settings on results of automated semen analysis, microscopic images of 43 semen samples were videotaped. Tapes were analyzed by the CellSoft system (CRYO Resources Ltd., New York, NY) at 12 different parameter combinations for gray scale, number of frames analyzed, and minimum number of frames analyzed for velocity measurements. The data indicate that values obtained for concentration, percentage of motile sperm, velocity, and linearity depend, to varying degrees, on the settings of the computer. It is concluded that results of automated semen analysis may not be comparable among different laboratories unless identical parameter settings are used. The need for general agreement of these details among different users is stressed.

Autoanalysis↗