Showing papers on "Semen published in 1994"

Conventional in vitro fertilization versus intracytoplasmic sperm injection for patients requiring microsurgical sperm aspiration

Abstract: Intracytoplasmic sperm injection (ICSI) has been successful in cases of extreme oligoasthenozoospermia in achieving pregnancies via in-vitro fertilization (IVF) with the lowest imaginable sperm counts. In azoospermia caused by congenital bilateral absence of the vas deferens (CBAVD), it has been shown that epididymal spermatozoa can be retrieved in large numbers, but fertilization rates using conventional IVF are low. Furthermore, no fertilization has ever been possible using testicular spermatozoa with conventional IVF. In the most extreme case of absence of the epididymis, spermatozoa can only be retrieved from macerated testicular biopsy specimens. In such cases, all that can be seen are free-floating Sertoli cells with many spermatids attached, and only occasional spermatozoa per high power field which have only the barest, occasional, slightly twitching motion. The objective of the present study was to determine whether ICSI could achieve better results than conventional IVF with microsurgical aspiration of spermatozoa (MESA). ICSI (using epididymal or testicular spermatozoa) from men with CBAVD or irreparable obstructive azoospermia, achieved good fertilization and normal embryos in 82% of cases, compared to 19% with conventional IVF. There was an overall fertilization rate of 45%, with 85% progressing to normally cleaving embryos using ICSI, compared to 6.9% using conventional IVF. The pregnancy rate with ICSI/MESA was 47% per stimulated cycle (normal delivery rate was 30%), compared to 4.5% with conventional IVF. These results were achieved in patients who had consistently failed to fertilize in previous cycles with MESA and conventional IVF.(ABSTRACT TRUNCATED AT 250 WORDS)

Leukocytic infiltration into the human ejaculate and its association with semen quality, oxidative stress, and sperm function

Abstract: Immunocytochemical techniques have been used to monitor the size and composition of the leukocyte population in unfractionated human semen samples and sperm populations generated by Percoll gradient centrifugation. The characteristics of the leukocyte population have then been related to the quality of the semen profile, the production of reactive oxygen species, and the functional competence of the spermatozoa. A majority (97%) of the ejaculates examined contained leukocytes, and in 82.4% the major cell type was the granulocyte. Small numbers of T cells, B cells, and monocytes/macrophages could also be found in 62%, 43%, and 21% of samples, respectively, and patients were occasionally identified in whom one of these cell types became the predominant leukocyte species. Although a subpopulation of patients was identified in whom the infiltration of multiple leukocyte species was positively correlated with the concentrations of spermatozoa and precursor germ cells in semen, in general, the presence of leukocytes, to the point of leukocytospermia, did not significantly influence any component of the semen profile. Similarly, the fertilizing potential of the washed spermatozoa, as assessed by in vitro tests of the acrosome reaction and sperm-oocyte fusion, was not correlated with the concentration of seminal leukocytes. In contrast, the carryover of leukocytes into the washed sperm preparations profoundly influenced the fertilizing potential of the spermatozoa via mechanisms that were associated with the production of reactive oxygen species. These results have implications for the diagnostic significance of leukocyte contamination in the context of male infertility and assisted conception.

Sperm displacement without sperm transfer in drosophila melanogaster.

Abstract: In this paper we show that when Drosophila melanogaster females are mated twice, the semen of the second male causes a reduction of the effective number of resident sperm from the previous mating. This is demonstrated by two different kinds of experiments. In one set of experiments, mated females were remated to two different kinds of sterile males, one with normal semen and the other with deficient semen. The effect on the resident sperm was determined from the number of remaining progeny after mating to the sterile male, with the result that the normal semen reduced the amount of resident sperm in comparison with matings to the males with deficient semen. The second set of experiments employed interrupted matings. These experiments were based on the observation that semen is delivered before sperm during the first 5 min of copulation. The second matings were interrupted instantly, 2 min, and 4 min after the initiation of copulation. Compared to the instant interruptions, the two later interruptions had the effect of reducing the amount of resident sperm. The results of these two experiments clearly indicate that a sperm-incapacitation process plays a role in the well-documented phenomenon of sperm displacement (last-male advantage) in this species. Such a process could play a role in sperm displacement in the many cases where the mechanism is unknown.

Excretion of porcine reproductive and respiratory syndrome virus in semen after experimentally induced infection in boars.

Abstract: Four boars intranasally inoculated with porcine reproductive and respiratory syndrome (PRRS) virus were monitored for 56 days after exposure for changes in semen characteristics and for the presence of virus in the semen. Clinically, 2 of 4 boars had mild respiratory signs of 1 day's duration after infection. Changes in appetite, behavior, or libido were not detected. All boars seroconverted on the indirect fluorescent antibody and serum virus neutralization tests by day 14 after inoculation. Virus was isolated from serum between days 7 and 14 after inoculation. During the monitoring period, semen volume decreased and pH correspondingly increased; however, this change began 7 to 10 days prior to infection. Differences in sperm morphologic features, concentration, or motility between the preinfection and postinfection samples were not observed. The PRRS virus was detected in semen at the first collection in each of the 4 boars (ie, 3 or 5 days after challenge exposure). Virus was detected in nearly all semen samples collected from the 4 infected boars through days 13, 25, 27, and 43, respectively. Neither gross nor microscopic lesions attributable to PRRS virus were observed in tissues collected at the termination of the experiment (day 56), and virus isolation results from reproductive tissues were negative.

Major proteins of bovine seminal vesicles bind to spermatozoa.

Abstract: Bovine seminal vesicles synthesize a family of closely related proteins, namely BSP-A1, BSP-A2, BSP-A3, and BSP-30-kDa (collectively called BSP proteins). Recently, we showed that these proteins bind specifically to choline phospholipids. Since this class of phospholipids is the major phospholipid fraction of the spermatozoan membrane, we investigated the binding of BSP proteins to spermatozoa. Polyclonal antibodies against purified BSP proteins raised in rabbits were used to detect these antigens in bovine epididymal and ejaculated spermatozoa as well as in bovine seminal plasma. Comparison of spermatozoa taken from the caudae epididymides with ejaculated spermatozoa through use of various techniques, namely, surface labeling followed by immunoprecipitation and immunoblotting, showed that epididymal spermatozoa are devoid of BSP proteins whereas ejaculated spermatozoa possess membrane-bound BSP proteins. Through use of the indirect immunofluorescence technique, the ejaculated spermatozoa of bull were characterized by an immunoreaction restricted to the midpiece, acrosome, and postacrosomal region, but no specific immunostaining could be found on the surface of epididymal spermatozoa. Surface-labeled BSP proteins on spermatozoa could not be displaced with buffers containing high salt concentration (1 M NaCI), but could be displaced specifically with phosphorylcholine (alone or in combination with urea). The data indicate that the BSP proteins that are secretory products of the seminal vesicles bind to the sperm surface upon ejaculation.

Survival of ram spermatozoa at high dilution: protective effect of simple constituents of culture media as compared with seminal plasma

Abstract: During incubation of ram spermatozoa at 1 x 10(7) cells mL-1 or less in a simple HEPES-buffered saline medium, high levels of cell death were detected using propidium iodide as a probe of viability (membrane integrity): some 70% of the cells died during 3 h incubation at 37 degrees C. Because the conditions of incubation were similar to those encountered during manipulations for in vitro fertilization, this phenomenon was investigated further. If ram spermatozoa were diluted in an equivalent sucrose-based medium, or if the saline medium was supplemented with 10% seminal plasma, survival was greatly improved (only 5-15% died during a 3-h incubation at 37 degrees C); the protective effect of seminal plasma resided in a 5-10 kDa fraction. Sperm death in the basal saline medium was strongly dependent on cell concentration below 5 x 10(7) spermatozoa mL-1 whereas little effect of concentration was seen in the sucrose medium or in the presence of seminal plasma. The presence of Ca2+ (2 mM), EGTA (1 mM) or mercaptoethanol (1 mM) enhanced sperm survival in saline medium, but no effect was gained by replacing NaCl with KCl, and neither BSA nor fetal calf serum were beneficial. However, when a combination of pyruvate (1 mM), lactate (21.7 mM), Mg2+ (0.4 mM), phosphate (0.3 mM) and Ca2+ (2 mM) was included in the saline medium (to render it similar to Tyrode's medium), cell survival was greatly improved (12% died during the 3-h incubation).(ABSTRACT TRUNCATED AT 250 WORDS)

Relationship between biochemical constituents of fish semen and fertility: the effect of short-term storage

Abstract: Spermatozoa and seminal plasma obtained from rainbow trout and whitefish were analyzed in respect to their aspartate aminotransferase (AspAT) and alkaline phosphatase activities. In particular, the experiments characterized AspAT optimum pH, optimization of assay conditions and action of coenzyme, pyridoxal 5-phosphate (vitamin B6). The effect of short-term semen storage at 0°C on biochemical indicators and fertilization rate was examined in both species. The concentrations of reduced and oxidized ascorbic acid in seminal plasma of both species were several folds higher than in spermatozoa and blood plasma of fish. Highly significant correlations were found for both species between AspAT activity (sperm or seminal plasma) and fertilization rate (% of eyed-stage or hatched embryos). For rainbow trout, highly significant correlations were found between sperm concentration, motility and fertilization rate. These results suggest that several biochemical indicators of seminal plasma can be used as measures of sperm quality of fish. Some common biochemical parameters for fish and mammal's semen provide evidence for using fish sperm as a model in biomedical research.

Sperm recovery techniques to maximize fertilizing capacity

Abstract: Because seminal plasma contains factors that inhibit the fertilizing ability of spermatozoa, it is essential that spermatozoa be separated from it quickly and efficiently. Although the success of a sperm preparation method is often assessed by the yield of motile spermatozoa, the choice of a method also depends on its technical complexity, the materials and apparatus required and time costs. Any exposure of spermatozoa during preparation to factors that may cause iatrogenic sperm dysfunction must obviously be avoided. Consequently, methods involving centrifugal washing prior to the selection of motile spermatozoa should be avoided. Direct swim-up from semen is the simplest way to obtain highly motile sperm populations and can be a very rapid procedure with normal semen samples. Two-layer discontinuous Percoll gradients give excellent yields when the lower layer contains 81% (v/v) Percoll. However, for severely asthenozoospermic cases the results can be disappointing and a Nycodenz gradient may be better, although the 'mini-Percoll' technique might be useful if special care is taken to protect the spermatozoa from damage induced by free radicals. In such cases the migration-sedimentation approach can also be successful. Abnormal samples, especially those with increased viscosity, may benefit from prior dilution with culture medium, or even chymotrypsin-induced liquefaction, before density gradient centrifugation. Finally, pharmacological stimulation of sperm motility may increase yields but, for in vitro fertilization (IVF), such spermatozoa must be used to inseminate oocytes as soon as possible after exposure to the stimulant, although after its removal.

Effect of natural antioxidants tocopherol and ascorbic acids in maintenance of sperm activity during freeze-thaw process.

Abstract: Excessive generation of reactive oxygen species and increased peroxidation of the phospholipids in the membrane is proposed as a biochemical basis for the reduced activity of spermatozoa in cryopreserved semen. The possible role of alpha-tocopherol (VE) and ascorbic acid (VC) in improving the quality of frozen semen was investigated. Semen samples were divided into aliquots and frozen in freezing media with and without VC or VE. Sperm parameters, including motility after thawing and also at 2 h, % grade A motility (rapid and linear forward progression), and hypoosmotic swelling (HOS) scores, were measured in all samples. Vitamin C did not result in any improvement in sperm parameters studies. Vitamin E improved the post-thaw motility minimally. This improvement, although statistically significant, was actually very small. There were, however, wide variations between the samples. The motility improvement was considered in 5 of 12 samples, and HOS improved in some of the samples tested with VE. Future studies are needed to determine if these antioxidants can produce a consistent improvement in some individuals rather than help the majority of patients.

Effect of sperm washing on levels of reactive oxygen species in semen

Abstract: The possibility was evaluated that the production of reactive oxygen species (ROS) by human sperm is stimulated by the repeated cycles of centrifugation and resuspension involved in conventional sperm preparation. ROS generation by human sperm was monitored before and after the washing of sperm from 55 men (43 men with suspected subfertility and 12 normal volunteers). The ROS activity of all 55 specimens before washing was inversely correlated with original sperm motility (r = .278, p < .05). The mean level of ROS activity was significantly higher after washing than before processing (p < .05) for the 26 specimens with normal sperm motility, the 20 specimens with normal sperm morphology, and the 12 specimens with both normal motility and normal morphology. In contrast, the mean ROS level was not significantly changed after washing in the 27 specimens with poor sperm motility, the 16 specimens with abnormal sperm morphology, or the 13 specimens with both abnormal motility and abnormal morphology. It would appear that repeated centrifugation, resuspension, and vortexing cause excessive generation of ROS in the motile sperm population of the washed specimen. Washing procedures involving excessive manipulation of sperm may, in fact, cause the most harm to motile sperm, i.e., those that the method is trying to select. Procedures that minimize multiple centrifugation, resuspension, and vortexing steps should therefore be used for the preparation of semen specimens for assisted-reproduction techniques.

Detection and biologic characterization of infectious HIV-1 in semen of seropositive men

Abstract: OBJECTIVE Factors that influence the infectivity of an individual and the impact of antiviral treatment on infectivity are not well defined. This study investigated the value of a sensitive method for detecting infectious HIV in semen for use as a marker for infectivity. DESIGN A cross-sectional study of infectious HIV in the semen of 33 HIV-positive men. METHODS A sensitive method for detecting infectious HIV in semen was used. The correlation of culture in semen with clinical and laboratory data was investigated. Biological phenotypes of isolates from blood and semen were tested using an MT-2 assay. RESULTS HIV cultures from seminal cells were positive in 18 patients (55%) and in one patient from seminal plasma. Higher recovery rates of HIV from semen correlated with a low CD4 count (80% in patients with a CD4 count > 100 x 10(6)/l versus 33% in patients with a CD4 count < 100 x 10(6) cells; P < 0.025) and symptomatic disease (78 versus 27% in asymptomatic patients; P < 0.01). Recovery of HIV from semen was independent of presence or absence of plasma viremia and the biological phenotype of blood isolates. Ten patients with syncytium-inducing (SI) isolates in their blood had positive semen cultures for HIV. Seven of the 10 patients had SI isolates recovered from their semen, whereas three had non-SI isolates only. CONCLUSION Data from partner studies show higher rates of HIV transmission for patients with low CD4 counts and symptomatic disease. The compatibility of epidemiologic data with our finding that significantly more HIV is recovered in semen from patients with advanced disease, suggests that HIV culture of semen samples may provide a useful surrogate marker to measure infectivity in clinical studies. Further studies are needed to define the inoculum required to transmit HIV and to study the impact of sexually transmitted diseases and HIV-1 phenotype on semen infectivity.

Effect of cadmium and cigarette smoking on human semen quality

Abstract: OBJECTIVE: In recent years, there have been many nonconclusive studies on cigarette smoking and sperm quality. Few studies, if any, have attempted to implicate any decrease of sperm quality. The aim of this study was to examine the relationship between cigarette smoking, blood and seminal plasma concentrations of cadmium and lead, and sperm quality. METHODS: A total of 184 males who were undergoing initial screening for infertility were included in the study. Tests conducted included semen characteristics (volume, total sperm count, sperm viability, motility and morphology of spermatozoa), and blood and seminal plasma concentrations of lead and cadmium. RESULTS: More than 50% and 70% of the subjects had normal sperm density and motility, respectively. The mean concentrations of lead in blood (PbB) and seminal plasma (PbS) were 7.09 micrograms/dL and 12.98 micrograms/L, respectively, while the mean concentrations of cadmium in blood (CdB) and seminal plasma (CdS) were 0.95 micrograms/L, and 0.58 micrograms/L, respectively. Significant correlations were observed between CdB and cigarette-years and sperm density (negative). CdS was significantly correlated with cigarette-years and sperm volume (negative). Significant trends were observed for different categories of cigarette-years with CdB, CdS and sperm density. CONCLUSION: Cigarette smoking appears to affect sperm density, especially in heavy smokers. Cadmium (present) in cigarettes could be a possible causative agent for the low sperm density among smokers.

Increased Levels of Interleukin‐6 in Seminal Plasma of Infertile Men

Abstract: The presence of various cytokines, namely the tumor necrosis factor (TNF-alpha), interferon (IFN-gamma), and interleukins (IL-1 beta and IL-6), was investigated in seminal plasma of fertile, infertile, and immunoinfertile men using specific immunoradiometric assays. TNF-alpha and IL-1 beta were not detected. IFN-gamma was detected, but the differences between the levels of fertile and infertile/immunoinfertile were not significant (P > 0.05). IL-6 was detected in seminal plasma with significantly higher levels in infertile/immunoinfertile men compared to those of fertile men. IL-6 was also present in sera, and interestingly, the levels in sera were lower than those in seminal plasma. IL-6 levels in seminal plasma correlated significantly with some sperm parameters and penetration rates in the human sperm penetration assay (SPA). These findings suggest that IL-6 is associated with infertility and may be of importance in specific diagnosis and treatment of male infertility.

Improved diagnosis of male fertility potential via a combination of quantitative ultramorphology and routine semen analyses.

Abstract: The aim of this study was to develop a new male fertility diagnostic profile based on quantitative ultramorphology parameters and to determine the contribution of this profile to the enhancement of the routine semen analysis index reported previously. Semen samples from 208 males of known fertility and suspected infertility were evaluated for the ultrafine structure of the following sperm cell organelles: acrosome, post-acrosomal lamina, nucleus, neck, axonema, mitochondrial and fibrous sheaths. For each of these organelles, four pathological states (agenesis, incomplete genesis, malformation and degradation) and an intact state were defined. A quantitative ultramorphology index based on the incidence of intact nucleus, acrosome and fibrous sheath malformations enabled high accuracy in the classification (97% sensitivity and 90% specificity) of 74% of the cases. A combined semen quality index based on a proportional combination of the semen analysis and quantitative ultramorphology indices was found to increase the percentage of cases classified correctly to 80%. It was proposed that semen specimens of males whose fertility status cannot be predicted clearly using routine semen analysis should be fixed and sent for quantitative ultramorphology analysis to specialized laboratories so that their fertility potential can be determined more accurately using the semen quality index.

The outcome of widespread use of semen from a bull persistently infected with pestivirus.

Abstract: During the certification of the bulls at an artificial breeding centre for freedom from pestivirus infection, a single viraemic bull was identified, and further testing confirmed that it was persistently infected. The two-year-old bull was healthy and of similar bodyweight to its peers. Its semen was of normal quality on the basis of density, motility and morphological criteria. Approximately 600 doses of semen had been distributed for sire evaluation purposes to 97 dairy farms. An examination of the breeding records indicated a first service conception rate of 38 per cent. All but one of the 162 cows inseminated with the bull's semen were seropositive compared with 95 of 143 cows (66.4 per cent) inseminated with semen from other bulls. Virological studies of the 61 calves sired by the persistently infected bull revealed that two were persistently infected, but that the others were healthy and uninfected. It was concluded that the semen from this bull was a potential source of pestivirus infection for 'clean' herds.

Drugs in Semen

Abstract: Over the past 50 years, a decline in the quality of semen has been observed, possibly resulting in a reduction in male fertility. Among the factors affecting semen quality, exposure to drugs is of particular importance. It is known that drugs can be transported to the seminal plasma, which is made up of secretions from the various accessory genital glands. There is evidence that many drugs enter the male genitourinary tract by an ion-trapping process. Lipid solubility and the degree of ionisation of the drug, which depend on the pH of plasma and seminal fluid, are important factors in this process. To date, few studies have been conducted on this topic. Pharmacokinetic evaluation of the fluids of the male accessory gland have been performed in the case of chloroquine and caffeine only, while the effects of mesalazine (5-aminosalicylic acid), sulfasalazine, salicylate, propranolol, diltiazem, flunarizine, verapamil, caffeine and nicotine on sperm physiology and morphology have been examined. Although data from the literature are scarce and incomplete, it is evident that many drugs can be excreted into semen. These drugs may interfere with the most common semen characteristics, potentially resulting in a male-mediated teratogenic effect, or local and systemic responses in female recipients. Therefore, it may be advisable to include, in the processes of drug development, pharmacokinetic evaluation of a drug in the semen and analysis of standard microscopic parameters of the semen. This is particularly important for drugs known to concentrate in the semen.