Development of a radioimmunoassay for human seminal plasma inhibin.

Using a homogeneous inhibin preparation from human seminal plasma with a molecular weight of about 19 000, a sensitive and specific radioimmunoassay (RIA) for inhibin has been developed. None of the purified hormones tested, such as LH, FSH and prolactin from different species, showed any cross-reaction in this RIA. Steroid hormones such as testosterone, dihydrotestosterone, oestradiol-17 beta and progesterone did not interfere with the assay. The antiserum had an affinity constant (Ka) of 2.379 X 10(9). The assay sensitivity was 10-15 ng per tube and the intra- and inter-assay coefficients of variation were 5-7% (n = 6) and 15% (n = 10) respectively. The recovery for inhibin added to the serum of a castrated man was 95-110%. Using this RIA, inhibin levels in various biological fluids and tissues were measured. Normo-spermic semen contained significantly higher levels of inhibin than did oligospermic semen. Human prostate contained a substantial quantity of inhibin. Monkey semen, rat serum, and bovine, ovine and porcine follicular fluids cross-reacted in the RIA, while ram testicular inhibin and bull semen did not do so. In developing (9-28 days of age) male rats, circulating inhibin levels showed an inverse relationship with serum FSH levels. In female rats of this age endogenous inhibin concentrations changed in parallel with those of serum FSH.     

Assessment of acrosomal integrity of vervet monkey spermatozoa after cryopreservation

Cryopreservation of Vervet monkey semen caused a highly significant reduction in the percentage of normal acrosomes and a highly significant increase in the percentage of mildly damaged, severely damaged, and lost acrosomes. This was demonstrated by staining ten post-thaw semen samples, which enabled a visualization of the acrosomal damage. The incidence of post-thaw intact acrosomes in this cryopreservation method was found to be similar to that reported for man and cynomolgus monkey semen.     

The transport of chemicals in semen

Three mechanisms have been proposed for exposure of the conceptus to chemicals in semen: access of chemicals to the maternal circulation after absorption from the vagina, direct chemical exposure of the conceptus following transport from the vagina to the uterine cavity, and delivery to the egg and subsequent conceptus of chemical bound to the sperm cell. We review published data for each of these three mechanisms. Human seminal fluid chemical concentrations are typically similar to or lower than blood concentrations, although some antimicrobial agents achieve higher concentrations in semen than in blood. Vaginal absorption of medications has been shown to occur, although the vehicles in which these medications are delivered to the vagina may maintain contact with the vaginal epithelium to a greater extent than does semen. Assuming total absorption of a seminal dose of a chemical with a high semen:blood concentration ratio, distribution within the recipient woman would result in a blood concentration at least three orders of magnitude lower than that in the man. Direct delivery of seminal chemicals into the uterine cavity of humans has not been shown to occur, although it may occur in species such as the rat in which seminal fluid has access to the uterine cavity. Chemicals in or on human sperm cells have been demonstrated with respect to tetracycline and cocaine in vitro and aluminum, lead, and cadmium in vivo. The in vitro cocaine study offers sufficiently quantitative data with which to predict that oocyte concentrations would be five orders of magnitude lower than blood concentrations associated with cocaine abuse, assuming a maximally cocaine-bound sperm were capable of fertilizing. Thus, even using liberal assumptions about transmission of chemicals in semen or sperm, predicted exposure levels of a pregnant woman or of the conceptus are three or more orders of magnitude lower than blood concentrations in the man whose semen is the putative vehicle for chemical transport.     

HIV-specific CD8+ lymphocytes in semen are not associated with reduced HIV shedding

Sexual contact with HIV-infected semen is a major driving force behind the global HIV pandemic. Little is known regarding the immune correlates of virus shedding in this compartment, although HIV-1-specific CD8+ T cells are present in semen. We collected blood and semen from 27 chronically HIV-infected, therapy-naive men without common sexually transmitted infections or urethral inflammation and measured HIV-1 RNA viral load and cytokine/chemokine levels in both compartments. HIV-1 RNA levels were 10-fold higher in blood than semen, but discordantly high semen shedding was associated with higher semen levels of the proinflammatory cytokines IL-6, IL-8, IL-12, and IFN-gamma. Virus-specific CD8+ T cell epitopes were mapped in blood by IFN-gamma ELISPOT, using an overlapping HIV-1 clade B peptide matrix, and blood and semen CD8+ T cell responses were then assayed ex vivo using intracellular IFN-gamma staining. HIV-specific CD8+ responses were detected in 70% of semen samples, and their frequency was similar to or higher than blood. There was no correlation between the presence of virus-specific CD8+ T cells in semen and levels of HIV-1 RNA shedding. Among participants with detectable CD8+ IFN-gamma semen responses, their relative frequency was not associated with reduced HIV-1 RNA shedding, and their absolute number was correlated with higher levels of HIV-1 RNA semen shedding (r = 0.6; p = 0.03) and of several proinflammatory cytokines. Neither the presence nor the frequency of semen HIV-specific CD8+ T cell IFN-gamma responses in semen correlated with reduced levels of HIV RNA in semen.     

Phosphorus-31 nuclear magnetic resonance studies of spermatozoa from the boar, ram, goat and bull

1. Phosphorus-31 nuclear magnetic resonance spectroscopy (31P-NMR) was utilized to examine semen and spermatozoa isolated from boars, rams, goats and bulls. 2. Whole semen was found to contain high but variable levels of glycerylphosphocholine, most of which was located in the seminal plasma rather than in the spermatozoa. 3. Spermatozoa concentrated into a pellet were found to contain resonances for inorganic phosphate, phosphomonoesters including fructose-1,6-bisphosphate and glucose-6-phosphate, and free nucleotide triphosphate peaks. 4. A broad resonance was observed from 30 to -25 ppm which originated partly from nucleotide tri- and diphosphates. 5. No high energy molecules such as phosphoarginine or phosphocreatine which could act as energy shuttles were observed.     

Flucloxacillin,a New Isoxazolyl Penicillin,Compared with Oxacillin,Cloxacillin, and Dicloxacillin

Flucloxacillin, a new isoxazole penicillin, is active against penicillinase-producing strains of Staphylococcus aureus and is well absorbed in man after oral and intramuscular administration. Compared with isoxazole penicillins in current clinical use—namely, oxacillin, cloxacillin, and dicloxacillin—flucloxacillin has proved as active against Gram-positive cocci, including penicillin-resistant staphylococci. The extent of binding of flucloxacillin to the protein of human serum was similar to that of oxacillin and cloxacillin and less than that of dicloxacillin. In man flucloxacillin given orally produced total and free serum levels higher than those obtained with oxacillin and cloxacillin; total serum levels similar to those of dicloxacillin, and free levels greater than those of dicloxacillin. Similarly, after intramuscular injection the free serum levels of flucloxacillin were higher than those of oxacillin, cloxacillin, and dicloxacillin.     

The effect of gossypol in cottonseed meal on performance and on hematological and semen traits in postpubertal Brahman bulls

The effects of a cottonseed meal diet containing high levels of free gossypol on hematological traits, including erythrocyte osmotic fragility and semen characteristics, were examined during an 11-week period. Eight Brahman bulls were randomly assigned to 1 of 2 groups. The control group (n=4) was fed a mixture of soybean meal and corn. The treated group (n=4) was fed a mixture of cottonseed meal and corn. Both groups were allowed hay free choice. The treated group consumed 8.2 g of free gossypol per bull per day. The percentage of normal spermatozoa was lower (P<0.01) in the treated than in the control group from Week 5 (49+/-9.8 vs 83+/-3.2%), which was primarily influenced by changes in mid piece morphology in the treated bulls. Erythrocyte osmotic fragility was higher (P<0.001) in the treated than in the control group over the entire study period, although group values diverged more acutely from Week 7 of treatment. Sperm motility was lower (P=0.04) in treated bulls than in control bulls at Week 9 (52+/-9.8 vs 82+/-6.2%). These data suggest that concurrent discernable changes in bull erythrocyte osmotic fragility and in semen characteristics can occur following commencement of a diet containing 8.2g of free gossypol per day.     

steve bAccumulation of nerve growth factor and its receptors in the uterus and dorsal root ganglia in a mouse model of adenomyosis

Background

The pregnancy hormone human chorionic gonadotropin (hCG) and its free subunits (hCG alpha, hCG beta) are produced in the male reproductive tract and found in high concentrations in seminal fluid, in particular hCG alpha. This study aimed to elucidate changes in peptide hormone profiles in patients showing abnormal semen analyses and to determine the genuineness of the highly abundant hCG alpha.

Methods

Seminal plasma was obtained from 45 male patients undergoing semen analysis during infertility workups. Comprehensive peptide hormone profiles were established by a panel of immunofluorometric assays for hCG, hCG alpha, hCG beta and its metabolite hCG beta core fragment, placental lactogen, growth hormone and prolactin in seminal plasma of patients with abnormal semen analysis results (n = 29) versus normozoospermic men (n = 16). The molecular identity of large hyperglycosylated hCG alpha was analyzed by mass-spectrometry and selective deglycosylation.

Results

hCG alpha levels were found to be significantly lower in men with impaired semen quality (1346 +/- 191 vs. 2753 +/- 533 ng/ml, P = 0.022). Moreover, patients with reduced sperm count had reduced intact hCG levels compared with normozoospermic men (0.097 +/- 0.022 vs. 0.203 +/- 0.040 ng/ml, P = 0.028). Using mass-spectrometry, the biochemical identity of hCG alpha purified from seminal plasma was verified. Under non-reducing conditions in SDS-PAGE, hCG alpha isolated from seminal plasma migrated in a manner comparable with large free hCG alpha with an apparent molecular mass (Mr, app) of 24 kDa, while hCG alpha dissociated from pregnancy-derived holo-hCG migrated at approximately 22 kDa. After deglycosylation with PNGase F under denaturing conditions, all hCG alpha variants showed an Mr, app of 15 kDa, indicating identical amino acid backbones.

Conclusions

The findings indicate a pathophysiological relevance of hCG, particularly its free alpha subunit, in spermatogenesis. The alternative glycosylation pattern on the free large hCG alpha in seminal plasma might reflect a modified function of this subunit in the male reproductive tract.     

Effect of Mycoplasma bovis and Mycoplasma bovigenitalium in semen on fertilization and association with in vitro produced morula and blastocyst stage embryos

Frozen-thawed bovine semen contaminated with Mycoplasma bovis (M. bovis) or Mycoplasma bovigenitalium (M. bovigenitalium) at either a high (10(6) CFU/mL) or low (10(4) CFU/mL) concentration was used for bovine oocyte insemination. The resulting embryos were washed 10 times as recommended by the International Embryo Transfer Society (IETS) prior to isolation of agent. A total of 1494 oocytes was inseminated with contaminated sperm cells and 855 oocytes with uninfected control semen. There was a significantly higher proportion of embryos that developed to the blastocyst stage in control than in the mycoplasma exposed groups (P<0.05). Isolation of motile spermatozoa by swim-up procedure prior to insemination did not render sperm cells free of Mycoplasma spp. Although M. bovis was isolated from all washed embryos after the high exposure level, it was found in only 60% of the samples after the low exposure level. In contrast, M. bovigenitalium was isolated from 70 and 12% of washed embryos exposed to the high and low levels of microorganism, respectively. Using scanning electron microscopy, both microorganisms were detected in association with the surface of zona pellucida-intact embryos and with sperm cells. These results indicate that mycoplasmas present in semen can be transmitted through the IVF system and infect embryos. Furthermore, the experiments showed that supplementation of culture media with standard antibiotics and washing embryos as recommended by IETS were not effective in rendering IVF embryos free from M. bovis and M. bovigenitalium.     

Effect of egg yolk lipids on the freezing of goat semen

Jamunapari goat buck semen contained both phospholipase and lysophospholipase activities which remained active during dilution (Step I) with diluents containing egg yolk, cooling to 5 degrees C (Step II), glycerolization and equilibration (Step III) and freezing and thawing (Step IV). A quantitative estimate of the phosphatidyl choline and phosphatidyl ethanolamine before and after freezing revealed that the lipids in egg yolk added to dilute goat semen were not hydrolysed to lysophospholipids and free fatty acids. Seminal plasma was, therefore, not removed and goat semen was frozen in egg yolk citrate-glucose, egg yolk-tris and skim milk-egg yolk. Dilution of goat semen 20 times with the three extenders containing 7% glycerol and an equilibration time of 3 h yielded optimum results. A comparative evaluation of freezing in the three diluents based on the assessment of sperm motility, live sperm count and acrosomal damage showed egg yolk-tris to be best extender for the successful freezing of goat semen. Insemination trials conducted with frozen semen and the number of actual kiddings yielded a fertility rate of approximately 81% in our study.     

Flow of blood to the ovaries of ewes throughout the estrous cycle: Niswender,G.D., R.T. Moore,A.M. Akbar,T.M. Nett and M.A. Diekman: Biol. Repr., 13: 381, 1975. Department of Physiology and Biophysics,Colorado State University,Fort Collins,Colorado 80523

This study was undertaken to determine whether a specific antimycoplasmal immune response could be detected in the male bovine genital tract and to better define mechanisms of immunity at that site. Specific $\text{Mycoplasma agalactiae}$ subsp. $\text{bovis}$ agglutinins were titrated in the serum, semen and preputial mucus extracts of two bulls with $\text{M. agalactiae}$ induced chronic seminal vesiculitis and of one normal control bull. Titers from infected bulls averaged 64 for serum, 1024 for semen and <8 for preputial mucus extracts whereas the control bull titers were 16 for serum, <8 for semen, and <8 for preputial mucus extracts. Because of the high semen agglutinin titers from infected bulls it was proposed that semen titers may be more useful diagnostically than serum titers.Studies of immunoglobulin levels in semen revealed that IgA, IgG₁ and IgG₂ levels were all much higher in infected bulls than in the control bull. These high semen IgA levels together with the high semen agglutinin titers indicated a local secretory immune response in genital tracts of infected bulls.     

Baisse de la production et de la qualite spermatique chez l’homme: Facteurs de variation et problemes méthodologiques

In the last few years, the possible decline of human semen quality as well as the important geographical variations of semen quality have been discussed in several scientific articles. In a meta-analysis of 61 publications worldwide, Carlsen et al. found a trend of decreasing sperm count over the past 50 years. This work has been at the origin of many commentaries and controversy. Two kinds of questions were mainly raised: Is the phenomenon real? what could be the reason(s) for such a decline? Many sceptical attitudes facing the conclusions of Carlsen et al. came from the fact that the studies included in the meta-analysis were done in various countries at different times, that the men studied could be very heterogeneous in term of fertility status and that the sample sizes of many studies were very low. It was also advocated that the results could be influenced by cofactors as the man’s age or the duration of sexual abstinence before semen collection or by differences in the methodologies used to analyse the semen samples in the various centers. Interestingly, several retrospective studies from a single centre were published after the meta-analysis of Carlsen reporting data from different groups of men recruited during more than 10 years periods in the last decades. Some of these studies found a decline of sperm concentration while for others, no secular modification of sperm concentration could be observed. It was also noticed important differences between values of semen characteristics in these various studies raising the question of geographical or regional differences besides the secular trend observed. Most of the published studies were very imprecis or poor of information concerning the men included in the study, the technical conditions used for semen analysis, the statistical methods used and the interpretation of the data. We discuss here some of the data of these studies in the context of the actual debate on the modifications of semen quality with the aim to pin-point the methodological bias contributing to the variation in the evaluation of semen quality. Moreover we also discuss the current data on the factors related to the men and their environment which could modulate sperm production and quality. It is mandatory to determine if the man’s reproductive function is influenced by environmental factors and if yes how they act. May be one of the main interest of the ongoing debate will be to develop basic and prospective epidemiological research in the field.     

Motility and fertility of alginate encapsulated boar spermatozoa

Ejaculated boar spermatozoa are vulnerable to cold shock. Prolonged storage of boar spermatozoa at low temperatures reduces survival rate, resulting in a bottleneck for the extension of artificial insemination in pig husbandry. This study evaluated whether alginate microencapsulization processing can improve the longevity of boar spermatozoa stored at 5 degrees C and the fertility of microencapsulated spermatozoa in vivo. Sperm-rich fraction semen from three purebred boars were concentrated and microencapsulated using alginate at 16-18 degrees C, and then were stored at 5 degrees C. Following storage for 1, 3 and 7 days, the microcapsule was taken out to assess sperm release under 37 degrees C incubation with or without 110 rpm stirring. The percentage of sperm released from microcapsules with 110 rpm stirring was higher than without stirring (81 versus 60%) after 24h of incubation. In another experiment, semen was also microencapsulated to evaluate the sperm motility. The motility of spermatozoa was assessed at 10 min, 8, 24, 32, 48, 56 and 72 h following incubation at 37 degrees C for nine consecutive days. The fertility of the free and microencapsulated semen was assessed by inseminating sows, and the reproductive traits (conception rate, farrowing rate, and litter size) were recorded. The motility of encapsulated spermatozoa was significantly higher than that of free semen after 8h incubation at 37 degrees C after storing for over three days (P<0.05). No significant difference existed in conception rate, farrowing rate, and litter size between the microencapsulated and non-encapsulated semen after four days of storage. In conclusion, microencapsulation can increase the longevity of boar spermatozoa and may sustain in vivo ova fertilization ability.     

The relationship between sperm DNA fragmentation,free radicals and antioxidant capacity with idiopathic repeated pregnancy loss

More than two consecutive miscarriages in less than 20 weeks of gestation is defined as recurrent spontaneous miscarriage. Various causes such as uterine anatomical anomalies, genetic factors, and infectious and endocrine disorders have been reported for RPL. However, approximately 50% of the causes are unknown, which can be due to male factors. Several studies have been done on semen parameters to determine the unknown causes and risk factors for miscarriages, however, only studying common semen parameters have not been sufficient. In this study, the relationship between sperm DNA fragmentation, the amount of free radicals, and total antioxidant capacity (TAC) in semen have been considered as a risk factor for spontaneous miscarriage. Semen samples were collected from 42 men whose partners had a history of spontaneous miscarriage and 42 fertile men as the control group. Volume, pH, viscosity, concentration, and motility of semen, as well as sperm morphology were measured. Sperm DNA fragmentation was analyzed by the sperm chromatin structure assay (SCSA) and TUNEL methods, the amount of sperm free radicals was measured by the luminescence method and the total amount of semen antioxidant was measured using the TAC kit. The results have shown that sperm motility in the experimental group was significantly less than the control group (P?=?0.001). The percentage of sperm DNA fragmentation and the amount of free radicals in the experimental group were significantly higher than the control group (P?<?0.001). The total amount of antioxidant was lower in the experimental group compared to the control. Spouses of men with lower sperm motility and higher DNA fragmentation had a higher chance of spontaneous miscarriage when compared to the control group. The results of this study support the hypothesis that sperm DNA fragmentation is a major contributor to spontaneous miscarriage.The relationship between SDF, ROS and TAC with RPL.     

Late failure of vasectomy after two documented analyses showing azoospermic semen.

From April 1970 to December 1980, 14 047 men underwent vasectomy for sterilisation under local anaesthetic at this clinic. In each man sterility was confirmed by two analyses of semen showing azoospermia. Allowing for a minimum follow up of three years, the wives of six of these men subsequently became pregnant between 16 months and three years after vasectomy. Analyses of semen confirmed recanalisation of the vasa deferentia in all six men. Only five similar cases initially fulfilling the same criteria for sterility have previously been reported. Full account of the rare possibility of recanalisation should be taken both when couples are counselled preoperatively and when pregnancy occurs after the male partner has been confirmed to be sterile.     

Follistatin supplementation during in vitro embryo culture improves developmental competence of bovine embryos produced using sex-sorted semen

Using sex-sorted semen to produce offspring of desired sex is associated with reduced developmental competence in vitro and lower fertility rates in vivo. The objectives of the present study were to investigate the effects of exogenous follistatin supplementation on the developmental competence of bovine embryos produced with sex-sorted semen and possible link between TGF-β regulated pathways and embryotrophic actions of follistatin. Effects of follistatin on expression of cell lineage markers (CDX2 and Nanog) and downstream targets of SMAD signaling (CTGF, ID1, ID2 and ID3) and AKT phosphorylation were investigated. Follistatin was supplemented during the initial 72?h of embryo culture. Exogenous follistatin restored the in vitro developmental competence of embryos produced with sex-sorted semen to the levels of control embryos produced with unsorted semen, and comparable results were obtained using sorted semen from three different bulls. The mRNA abundance for SMAD signaling downstream target genes, CTGF (SMAD 2/3 pathway) and ID2 (SMAD 1/5 pathway), was lower in blastocysts produced using sex-sorted versus unsorted semen, but mRNA levels for CDX2, NANOG, ID1 and ID3 were similar in both groups. Follistatin supplementation restored CTGF and ID2 mRNA in blastocysts produced using sex-sorted semen to levels of control embryos. Moreover, levels of phosphorylated (p)AKT (Ser-473 and Thr-308) were similar in embryos derived from sex-sorted and unsorted semen, but follistatin treatment increased pAKT levels in both groups. Taken together, results demonstrated that follistatin improves in vitro development of embryos produced with sex-sorted semen and such effects are associated with enhanced indices of SMAD signaling.     

Apoptotic-like changes in the spermatozoa of fresh and stored boar semen and the quality of embryos produced in vivo

The aim of this study was to determine the apoptotic-like changes in the spermatozoa of fresh and stored boar semen and to investigate the relationship between this phenomenon and the quality of embryos produced in vivo. The experiments were divided into two series. In the first series, ten ejaculates were collected from five boars, which were crossbreeds of the Polish Landrace and Large White breeds. The semen was stored as a liquid until Day A (the day on which sperm motility decreased to 30%). Three fluorescence methods were used to evaluate semen quality: an assay to assess the early changes in sperm membrane integrity using the fluorophore YO-PRO-1, an assay for phosphatidylserine (PS) translocation across the plasma membrane using fluorescein-labeled annexin-V and the mitochondrial-specific probe JC-1 (5,5',6,6'-tetrachloro-1,1',3,3' tetraethylbenzimidazolylcarbocyanine iodide) for measuring changes in mitochondrial membrane potential. Our results showed that liquid preservation of boar semen causes apoptotic-like changes in the sperm, and a significant increase in both: apoptotic sperm (YO-PRO-1(+)/PI(-)) and early apoptotic sperm (annexin-V(+)/PI(-)) were observed between Day 0 (fresh semen) and Day A only in semen from three of the five boars. In the second series of experiments, the semen from boar nos. 1, 2, and 3 was selected for insemination of superovulated gilts. The fertilizing capacity of fresh and stored semen with different levels of apoptotic spermatozoa was measured based on the morphology and the number of cells of embryos that were obtained after insemination with this semen. Our studies indicated no significant differences in the fertilization rate of gilts after insemination with fresh and stored semen with increased levels of apoptotic spermatozoa. After insemination with stored semen, a significantly greater number of degenerated embryos were observed, but the morphologically normal blastocysts obtained after insemination with either fresh or stored semen had a similar number of nuclei.     

Serum and semen levels of immunoreactive prolactin, LH and FSH in normospermic, oligospermic and azoospermic men with obstructive infertility prior to and after vasoepididymostomy.

Attempts were made to validate RIA for prolactin (PRL), LH and FSH in semen from normospermic, oligospermic and azoospermic subjects. The RIA used to measure PRL and LH in semen fulfilled the criteria of reliability, whereas low levels of FSH in semen precluded the validation of FSH assay in semen. Semen levels of PRL and LH were significantly (P < 0.05) higher than serum levels in all groups of subjects investigated. Semen levels of FSH in azoospermic men after vasoepididymostomy (VEA), were significantly (P < 0.05) higher compared to azoospermic men prior to surgery. Serum levels of PRL were significantly higher (P < 0.05) in normospermic men compared to oligospermic and azoospermic men prior to and after surgery. Semen levels of PRL in normospermic men were comparable with oligospermic and azoospermic subjects prior to and after surgery. Serum levels of LH in oligospermic and azoospermic men who did not undergo surgery and in men reporting oligospermia after VEA were comparable to normospermic subjects but in men showing azoospermia post surgically, serum LH levels were significantly (P < 0.005) elevated. Semen levels of LH in men reporting azoospermia before surgery and in subjects showing oligospermia or azoospermia post surgically were significantly lower (P < 0.05) compared to men with normal sperm count. Serum levels of FSH were significantly elevated (P < 0.05) compared to semen levels in oligospermic men prior to surgery but this increase was not seen in post VEA subjects. These results were discussed.     

Detection of Neospora caninum in the semen and blood of naturally infected bulls

A prospective study was designed to investigate the presence of Neospora caninum in semen and blood of eight bulls seropositive to N. caninum using nested-PCR procedures. Positive semen and blood samples were bioassayed in a BALB/c nu/nu mouse model. Specific anti-N. caninum serological and interferon-gamma (IFN-gamma) responses were also studied. In parallel, five seronegative bulls acted as non-infected controls. All bulls were located in a collaborating AI centre and monitored for 22 weeks. Six of eight seropositive bulls showed N. caninum DNA in their semen and/or blood samples at some time during the course of the study. In all positive semen samples, we consistently found Neospora-DNA in the cell fraction and not in seminal plasma. Parasite load, as determined by a real-time PCR in nested-PCR positive semen samples, ranged from 1 to 10 parasites/ml. We found no association between the presence of N. caninum DNA in semen and blood. N. caninum could not be detected in the BALB/c nu/nu mice inoculated with PCR-positive semen or blood samples. Specific IgG antibody levels in seropositive bulls fluctuated over time, at times falling below cut-off level. The response was predominantly IgG2, with significant differences compared to control bulls (P < 0.05). The overall mean specific IFN-gamma response in seropositive bulls was also higher than those observed in the control group (P < 0.05), although extensive variation in individual responses was observed among bulls and over time. No significant association was found between bulls showing Neospora DNA in semen, blood, or both, and specific IgG, IgG1, IgG2, IgM and IgA levels or IFN-gamma response. This study is the first to report the presence of Neospora DNA in semen and blood of naturally-infected bulls. Our observations indicate intermittent presence of N. caninum in blood and semen and shedding in semen in low numbers.     

不育男性患者和健康男性血液与精浆中微量元素含量的对比分析

目的:研究不育患者精浆和血液中微量元素的含量,为男性不育的诊断和治疗提供理论依据。方法:对73例正常生育组男性和265例男性不育患者的精浆和血液中的锌、铁、铜、钙、镁、镉进行检测分析,分析两组血液和精浆微量元素的差异。结果:不育组患者精浆和血液中锌的含量明显低于正常对照组,铜、镉离子含量明显高于正常对照组,与正常对照组比较均有显著性差异(P<0.01);而两组中的钙、铁、镁的含量接近,差异无统计学意义(P>0.05)。不育组患者精浆中的锌元素水平明显高于血液锌含量,而血液中的镉含量明显高于精浆中的镉含量,差异有明显的统计学意义(P<0.05)。结论:精浆和血液中锌、铜、镉的变化与男性不育密切相关。