Quantitation of seminal factor IX and factor IXa in fertile, nonfertile, and vasectomy subjects: a step closer toward identifying a functional clotting system in human semen

Coagulation factor (F) IX is a zymogen of the plasma serine proteases, one that plays an essential role in the regulation of normal blood coagulation. Congenital defects of FIX synthesis or function cause hemophilia B (originally called hemophilia C). Factor IX is activated by Tissue Factor (TF):FVII/FVIIa complex and FXIa. Subsequent to its activation, FIXa combines with FVIIIa on the platelet surface and activates FX to FXa. Human semen forms a semi-solid gelatinous coagulum, which then liquefies within 5-20 minutes in vitro. In spite of evidence demonstrating the importance of the seminal coagulation and liquefaction process in terms of global fertility and despite the fact that the seminal coagulum is composed of fibrin-like material, it has always been addressed from the perspective of High Molecular Weight Seminal Vesicle (HMW-SV) proteins (Semenogelin I and II) and their cleavage by prostate-specific antigen rather than the conventional hemostatic factors. In this study and as part of our continuing investigation of human seminal clotting factors, we report here on seminal FIX and FIXa in normal, subfertile, and vasectomized subjects. Factors IX and FIXa were studied in a total of 119 semen specimens obtained from subfertile (n=18), normally fertile (n=34), and fertile sperm donors (n=27) and vasectomy subjects (n=40). Seminal FIX and FIXa levels were also measured in a group defined by normality in several parameters derived from the World Health Organization fertility criteria and termed "pooled normal semen parameters." Both FIX and FIXa were quantifiable in human semen. There was a wide individual variation in FIX and FIXa levels within groups. Despite the group size, statistically significant associations with fertility-related parameters were infrequent. There is a positive correlation between FIX and its activation product, FIXa (n=36; r=0.51; P <.05). Factor IXa elevation in the high sperm-clump group was significant (P <.05), and days of abstention correlated with FIXa levels (n=63; r=0.3; P <.05). The key finding of the present study is that both FIX and FIXa are present in concentrations that are not dissimilar to plasma levels and that are apparently functional, as the activated form is also present. This fact, taken with other reports of coagulation factors in semen, raises the likelihood that a functional set of hemostatic coagulation proteins exists in semen, potentially to interact with the HMW-SV proteins and the prostate-specific antigen system.     

Seminal tissue factor revisited

Studies of seminal tissue factor (TF) are few and mostly based on small numbers. Due to the reported lack of factor (F) X in semen, it has been suggested that TF may not have a role in seminal coagulum formation. However, recent identification of a number of haemostatic factors in semen justifies a re-evaluation of its occurrence. Semen specimens were collected from sub-fertile (n = 19), normally fertile (n = 33), semen donors (n = 30) and vasectomized subjects (n = 62), some fractionated into sperm, a prostasome-rich fraction and seminal plasma. Functional and antigenic TF levels were measured and related to conventional fertility parameters. Semen contains high concentration of functional and antigenic TF. Most TF was found in seminal plasma prepared by low-speed centrifugation. When further fractionated by ultracentrifugation much of this may reside in the pellet (prostasomal fraction). It was also detectable on sperm. TF antigen levels were higher in vasectomized subjects than sub-fertile, normally fertile, donor (p = 0.02) and a 'pooled normal semen parameters' (PNSP) stratification (derived from a combination of measurements) (p = 0.06). The sub-fertile group showed a wider variation than normal, donor or the PNSP subjects. Seminal TF antigen levels correlated significantly with sperm agglutination (p = 0.03) and abnormal sperm morphology (p = 0.04). Subjects with anti-sperm antibodies also showed high TF antigen levels. In conclusion, semen contains functional and antigenic TF at high concentrations. A full complement of clotting factors probably exists in semen, so some pro-coagulant role for TF should not be excluded. Decreased seminal TF levels appear to be associated with seminal parameters that are known to favour male fertility.     

Development of normal reference values for seminal reactive oxygen species and their correlation with leukocytes and semen parameters in a fertile population

Although reactive oxygen species (ROSs) are clearly implicated in the pathogenesis of male infertility, few studies have attempted to define the basal levels of ROSs in fertile men. Levels of ROSs are highly influenced by the presence of leukocytes and are associated with decreased seminal parameters. The objective of our study was to determine the normal ROS reference values in neat and washed semen of a fertile population and to correlate the leukocyte concentrations with seminal parameters. We evaluated 114 fertile men seeking vasectomy and 47 subfertile patients as a positive control. All samples were subjected to semen analysis and Endtz testing; chemiluminescence assay was used to determine ROS levels. All seminal parameters were significantly higher in the fertile men than in the subfertile patients. In nonleukocytospermic samples, ROS levels were lower in the fertile men than in the subfertile patients in neat (0.29 [0.18, 0.54] vs 0.94 [0.38, 1.51]) (P = .001) and washed semen (5.73 [1.90, 14.71] vs 23.4 [9.46, 115.55]) (P = .001). Similarly, in samples with leukocytes (Entdz, less than 1 x 10(6)/mL), ROS levels were lower in the fertile men in neat (0.75 [0.27, 1.71] vs 2.0 [0.97, 27.41]) (P = .001) and washed semen (15.85 [4.18, 62.16] vs 239.83 [33.4, 1193.75]) (P < .0001). As expected, samples with leukocytes had significantly higher ROS values in washed and neat semen. In the fertile population, ROSs were positively correlated with leukocytes and negatively correlated with sperm count and motility. In semen samples without leukocytes, the normality cutoff of ROSs was 0.55 x 10(4) counted photons per minute with 76.4% area under the curve (AUC) in the neat samples and 10.0 x 10(4) counted photons per minute with 77% AUC in the washed samples. In semen samples with leukocytes, the cutoff for ROSs in neat samples was 1.25 with 72.7% AUC and 51.5 with 81% AUC in the washed samples. We defined the cutoff levels of ROSs in a fertile population. Seminal leukocyte levels below 1 x 10(6)/mL were associated with increased ROSs. ROS levels were positively correlated with leukocytes and negatively correlated with sperm motility and concentration. Patients with normal seminal parameters and lower seminal leukocyte levels may benefit from therapeutic interventions that improve semen quality.     

Evaluation of tissue factor antigen level in human seminal plasma

We measured the seminal plasma levels of tissue factor (TF) and interleukin-6 (IL-6) in men and examined their relationship with sperm concentration and motility. The study comprised 71 patients in three groups: an infertile group with ( n=11) and without ( n=50) leukocytospermia and a fertile group ( n=10). The seminal plasma levels of TF were significantly higher in the infertile patients than in the fertile ones. The seminal plasma levels of both TF and IL-6 were significantly higher in the infertile patients with leukocytospermia than in those without leukocytospermia. In 54 nonazoopermic cases the seminal plasma levels of TF were significantly correlated with the sperm concentration and sperm motility. Further studies are necessary to clarify the role of TF in human fertilization.     

Seminal Factor VIII and von Willebrand Factor: a possible role of the conventional clotting system in human semen?

Factor (F) VIII circulates in blood complexed with von Willebrand Factor (vWF). Deficiency or defect accounts for haemophilia A and vWF disease. In blood, FVIII functions as a co-factor for FIXa in the activation of FX. Human semen coagulates and liquefies in a process that resembles and has some links with the conventional haemostatic process. A study elsewhere has detected traces, but not measurable levels, of FVIII coagulant activity (FVIII:C). In the present study we have assessed FVIII antigen (FVIII:Ag), FVIII:C and vWF antigen (vWF:Ag) levels in 159 semen specimens obtained from sub-fertile (n = 21), normally fertile (n = 38), fertile donors (n = 32), and vasectomized men (n = 57). Seminal FVIII:Ag levels were also measured in a group defined by several parameters derived from the World Health Organization (WHO) fertility criteria, termed "pooled normal semen parameters" (PNSP). Factor VIII:Ag levels were compared with conventional fertility parameters. In addition, both FVIII:C and vWF:Ag were assessed in a separate group of normal individuals (n = 11). Factor VIII:Ag, FVIII:C and vWF were present and quantifiable in human semen. Factor VIII:Ag levels were significantly lower in vasectomy subjects compared with donors (p = 0.01) or PNSP group (p = 0.01). Several trends taken together suggest an associations between FVIII:Ag and semen quality. Parallel investigations demonstrate FV, FVII, FVIIa, FIX, FIXa, FXa, FXI, FXII, tissue factor (TF) and tissue factor pathway inhibitor (TFPI) in semen. The present report therefore provides further evidence for the presence of a functioning clotting system in human semen.     

Anticoagulant potential of an antibody against factor VII

BACKGROUND: Hypercoagulability often resulting from sepsis, trauma, and other conditions is widely associated with thrombotic and cardiovascular disorders. The development of effective and safe anticoagulation is in great demand to relieve complications and improve human health. OBJECTIVE: We study the anticoagulant potential of a polyclonal antibody to human FVII (anti-hFVII Ab). METHODS AND RESULTS: Preincubating FVII with anti-hFVII Ab, we showed the significantly blocked tissue factor (TF)-dependent FVII activation monitored by a two-stage chromogenic assay. Consistently, the antibody depressed TF/FVII-catalyzed FX activation was shown on Western blotting analysis. As a result, TF procoagulation derived from rabbit brain thromboplastin was prolonged significantly by the preincubation of human normal plasma with the antibody, which mimicked FVII-deficient plasma in a single-stage clotting assay. In contrast, the anti-hFVII Ab had no effect on either FVIIa amidolytic activity or TF/FVIIa binary complex. CONCLUSIONS: Anti-hFVII Ab readily blocked clot formation, which was mediated by the upstream downregulation of the extrinsic coagulation of inhibiting FVII activation. Further research warrants establishing its in vivo application as an anticoagulant.     

The Evaluation of Routine Andrological Parameters in Human Semen/Auswertung der Routine-Parameter der Andrologie am Sperma

A study was carried out to evaluate the andrological parameters in 540 human semen specimens divided into groups according to sperm counts. The parameters were: motility percentage and grade, percentage of viability and of morphologically normal sperm and immature cells. The Duncan multiple range test and the Kruskal-Wallis test with multiple comparison of ranks were used in the statistical analyses. Of particular interest, among other our findings, were the significant differences obtained by comparing the group with sperm counts up to 5 x 10(6) per ml semen and that with counts ranging from 5.1 to 10 x 10(6) per ml semen. This was true for all parameters with the exception of semen volume. Comparison of the oligozoospermic groups (up to 20 x 10(6)/ml) with those having higher sperm counts also showed significant differences. There was a trend towards improvement of the examined parameters with the increase in sperm density, but with a remarkable heterogeneity particularly within the oligozoospermic groups. In all groups motility, viability and morphological normality of sperm showed a positive correlation with each other. "Normal values" of the parameters studied could be derived from scatterplot charts over the entire range of sperm counts and from the statistical evaluation of the grouped material.     

Sialyl transferase in human semen

The activity of the enzyme sialyl transferase, which is responsible for the transfer of sialic acid, has been examined in the following human seminal plasma: (1) originating from semen with sperm counts above 30 X 10(6)/ml and exhibiting normal values of other andrological parameters; (2) from semen with sperm counts below 25 X 10(6)/ml and with other andrological parameters of poor quality; (3) from semen devoid of sperm. Additionally, enzyme activity was examined in fractionated (split) semen. The activity in plasma based on measurement of radioactivity incorporated into asialofetuin, following incubation in the presence of 14C sialic acid, was expressed as cpm both per volume and per mg protein. There was a tendency for decreased activity with the decrease in sperm density of semen. The difference, however, lacked statistical significance. Enzyme activity in split semen was significantly lower in the first than in the second fraction.     

Relationship between seminal plasma interleukin-6 and tumor necrosis factor alpha levels with semen parameters in fertile and infertile men

The levels of two proinflammatory cytokines, namely tumor necrosis factor alpha (TNF-alpha) and interleukin 6 (IL-6), were investigated in seminal plasma (SP) of proven fertile (n=24) and infertile (n=55) men to evaluate the relationship between diagnosis and semen parameters in a prospective study. Infertile men were divided into four groups as follows: (1) varicocele (n=23), (2) 3 months after varicocelectomy (post-varicocele, n=14), (3) male accessory gland infection (MAGI, n=10) and (4) bilateral testicular atrophy (n=8). IL-6 and TNF-alpha levels were similar in the SP of fertile and infertile men. There was a strong correlation between the levels of TNF-alpha and IL-6 in all groups (P<0.001). IL-6 levels were not correlated with seminal parameters (P>0.05). TNF-alpha levels were negatively correlated with the sperm motility and morphology (P<0.05), but there was no correlation with total sperm counts (P>0.05). The mean levels of IL-6 in the SP of the MAGI group was higher than in the other groups but did not reach statistical significance. No variation was found in the SP levels of the proinflammatory cytokines studied between the varicocele and the post-varicocele groups. Our results suggest that IL-6 and TNF-alpha are involved in male fertility. However, their measurement in SP seem to be unsuitable for routine infertility work, perhaps with the exception of men with inflammatory genital diseases.     

Human Seminal Transferrin: Correlation with Seminal and Hormonal Parameters/Transferrin des Spermaplasmas: Beziehungen zwischen den Sperma- und Hormon-Parametern

Transferrin (TF) concentrations were assessed in semen from 10 fertile controls and 79 infertile patients by a radioimmunoassay method. A positive correlation between seminal TF concentration and sperm count was found in the whole sample of patients and within the control group. A statistically significant difference was found between azoospermic and severely oligospermic patients and all the others. No correlation was found with other seminal parameters or hormonal values.     

Secular and seasonal changes in semen quality among young Danish men: a statistical analysis of semen samples from 1927 donor candidates during 1977-1995

The objective of this study was to investigate whether semen quality has changed during the years 1977-1995 in a group of unselected semen donor candidates, and to determine whether semen quality is subject to seasonal variation, by analysis of time- and season-related changes in semen quality using multiple regression and ANOVA. The study was based on analysis of the first semen sample delivered by 1927 semen donor candidates in Copenhagen during the period 1977-1995, with determination of semen volume, sperm concentration, total sperm count, percentage motile spermatozoa, and a semiquantitative sperm motility score. Multiple linear regression analysis with year, sexual abstinence and season as covariates showed a significant increase in mean sperm concentration from 53.0 x 10(6)/mL in 1977 to 72.7 x 10(6)/mL in 1995 (p < 0.0001) and in mean total sperm count from 166.0 x 10(6) to 227.6 x 10(6) (p < 0.0001). Mean semen volume and percentage motile spermatozoa did not change. Sperm motility deteriorated, as the spermatozoa in 74.2% of the samples were of excellent motility in 1977-1980 compared to only 41.9% in 1993-1995 (chi 2 = 130.0, p < 0.0001). Analysis of variance showed significant variation between seasons regarding sperm concentration (p < 0.0001) and total sperm count (p < 0.0001). Highest sperm counts were found in spring, with a mean concentration (95% C.I.) of 77.6 x 10(6)/mL (71.9-83.7), and lowest in summer, with a mean of 57.5 x 10(6)/mL (50.1-65.4). No other semen parameter varied with season. It is concluded that sperm counts increased, whereas sperm motility decreased, in a group of Danish semen donor candidates, from 1977 to 1995. Due to the retrospective design and the anonymity of the donors, we were unable to control for variation in donor age, and we cannot exclude the possibility that some donor candidates were selected by being accepted as donors by other semen donor services in Copenhagen. With these limitations in mind, we suggest our results should be interpreted cautiously and regarded as a contribution to the ongoing dispute on whether or not there is a continuous decrease in sperm quality. The seasonal variations found in sperm concentration and total sperm count were pronounced and were not attributable to seasonal differences in the length of sexual abstinence. Additionally, the same seasonal pattern was observed in five successive year-intervals. These findings strongly indicate that human testicular function is influenced by season, a phenomenon well known in many lower mammals.     

Improvement in the cervical mucus penetration test by using standard sperm control

The objective of the present experiments was to establish an acceptable standard for the cervical mucus penetration test (CMPT) by determining the minimal progressive motile spermatozoa concentration (PMSC) that will yield the highest score for proven fertile donor sperm specimens. For this purpose, fresh and frozen-thawed samples were used. Semen was obtained from 29 fertile donors and different PMSC (8, 10, and 14 x 10(6)/mL) were prepared for each sample. The same mucus specimen was used for testing each sperm sample in the three different dilutions. No difference in the scoring of the CMPT between the fresh vs. frozen-thawed groups was found. When PMSC of 14 x 10(6)/mL was used, almost all specimens scored the highest rank. The present study revealed that only semen samples with a minimal PMSC of 14 x 10(6)/mL cells can be used in the CMPT. The information that the freeze-thaw process does not affect the CMPT results supports the concept of cryopreservation of pooled fertile donor specimens in aliquots with adequate concentration of progressive motile spermatozoa for later use as a CMPT control.     

Have sperm counts deteriorated over the past 20 years in healthy, young Japanese men? Results from the Sapporo area

Changes in semen quality of healthy men is a controversial issue throughout the world. It is suspected that many chemical endocrine disrupters may affect the quality of semen. Although exposure to them may be extensive in Japan, no evidence of changes in semen quality has been reported. In this study, changes in semen volume and sperm counts were analyzed over 20 years in the Sapporo area of Japan. Semen volume and sperm counts were measured in 254 and 457 normal, healthy volunteers who lived in the Sapporo area in 1975-1980 and 1998, respectively. Posters and handbills were used to recruit participants in both studies. Semen samples were collected by masturbation after 3 days or more of abstinence. There was no change in semen volume between 1975-1980 and 1998. Mean sperm counts were 70.9 +/- 47.3 x 10(6)/mL in 1975-1980 and 79.6 +/- 49.3 x 10(6)/mL in 1998. Sperm counts did not decline over about 20 years. No significant correlation between age and sperm counts was recognized in either study. The rates of subjects with oligozoospermia and azoospermia were the same in both studies. In the 1975-1980 study, 34 of 254 (13.4%) participants had a child, and in the 1998 study, 51 of 457 (11.2%) participants had a child. Mean sperm count was significantly (P < .02) lower in the earlier study (66.0 +/- 44.9 x 106/mL) than in the 1998 study (98.7 +/- 60.2 x 10(6)/mL). This is the first reliable report in which changes in sperm counts in Japan were studied. We conclude that there was no evidence of deterioration in sperm counts of normal healthy men who lived in the Sapporo area of Japan over 20 years. However, selection bias in the recruitment of volunteers and the issue of variable abstinence might have affected the results of these studies. Therefore, well-designed prospective studies should be performed in several different regions to extrapolate our results on sperm counts to healthy, young Japanese men in general. Key words: Fertility, endocrine disruptors, seminalysis.     

免疫性不育男性精浆白细胞介素6和可溶性细胞黏附分子1分析

目的:检测男性免疫性不育患者精浆白介素6(IL-6)和可溶性细胞粘附分子1(s ICAM-1)水平,探讨炎症细胞因子与男性免疫性不育的关系。方法:按精子膜表面抗体免疫珠试验结果将临床疑为不育症患者分为免疫性不育组(Ig A或Ig G抗体黏附的精子数≥50%)41例、其他原因不育A组(10%≤Ig A或Ig G抗体黏附的精子数50%)37例,其他原因不育B组(Ig A或Ig G抗体黏附的精子数10%)45例。按白细胞过氧化物酶染色结果将免疫性不育患者分为免疫性白细胞阳性组和免疫性白细胞阴性组;选择同期因女方因素不孕前来检查的生育力评估正常的健康男性31例作为对照组。统计分析各组炎症因子精浆表达水平及精浆主要参数的差异。精液液化时间通过肉眼观察和显微镜进行识别判读,精子浓度及活力用计算机辅助精子分析系统,精子存活率采用低渗膨胀实验(HOS),抗精子抗体采用免疫珠试验(IBT);白细胞过氧化物酶染色采用正甲苯胺法,IL-6和s ICAM-1的含量测定采用酶联免疫吸附(ELISA)法。结果:各不育组与对照组比较,精子存活率和前向运动精子百分率有统计学差异(P0.05或P0.01)。免疫性不育组、其他原因不育A组、其他原因不育B组和对照组精浆IL-6(ng/L)、s ICAM-1(ng/ml)水平分别为37.92±17.01、89.15±41.82,22.23±13.77、67.81±33.24,18.75±14.32、53.25±27.09,9.47±5.76、19.46±9.77。各不育组与对照组比较,IL-6、s ICAM-1均有非常显著性差异(P0.01),免疫性不育组与其他原因不育两组分别比较差异均有统计学意义(P0.05或P0.01)。免疫性白细胞阳性组和免疫性白细胞阴性组精浆IL-6(ng/L)、s ICAM-1(ng/ml)的水平分别为49.25±21.46、104.36±46.41和31.38±15.54、80.38±35.52,两者比较均有统计学差异(P0.05)。结论:男性精浆中IL-6和s ICAM-1升高可能与免疫性不育有关。     

Assessment of seminal plasma laminin in fertile and infertile men

Aim： To assess laminin levels in the seminal plasma of infertile and fertile men, and to analyze the correlation of laminin levels with sperm count, age, sperm motility and semen volume. Methods： One hundred and twenty-five recruited men were equally divided into five groups according to their sperm concentration and clinical examination： fertile normozoospermia, oligoasthenozoospermia, non-obstructive azoospermia （NOA）, obstructive azoospermia （OA） and congenital bilateral absent vas deferens （CBAVD）. The patients＇ medical history was investigated and patients underwent clinical examination, conventional semen analysis and estimation of seminal plasma laminin by radioimmunoassay. Results： Seminal plasma laminin levels of successive groups were： 2.82 ± 0.62, 2.49 ± 0.44, 1.77 ± 0.56, 1.72 ± 0.76, 1.35 ± 0.63 U/mL, respectively. The fertile normozoospermic group showed the highest concentration compared to all infertile groups with significant differences compared to azoospermic groups （P 〈 0.05）. Testicular contribution was estimated to be approximately one-third of the seminal laminin. Seminal plasma laminin demonstrated significant correlation with sperm concentration （r = 0.460, P 〈 0.001） and nonsignificant correlation with age （r = 0.021, P = 0.940）, sperm motility percentage （r = 0.142, P = 0.615） and semen volume （r = 0.035, P = 0.087）. Conelusion： Seminal plasma laminin is derived mostly from prostatic and testicular portions and minimally from the seminal vesicle and vas deferens. Estimating seminal laminin alone is not conclusive in diagnosing different cases of male infertility.     

Seminal plasma transferrin concentration: relationship with seminal parameters and plasma hormone levels.

Seminal plasma transferrin concentrations were determined in 155 infertile male patients and in 15 pregnancy-proven fertile males (control group); then the relationship between these concentrations and seminal parameters and plasma hormone levels was investigated. The concentrations of seminal plasma transferrin in patients with a sperm concentration below 20 x 10(6)/ml were significantly lower than those in the control group (p < 0.01). There was no significant difference in seminal plasma transferrin concentration between patients with a sperm concentration of 40 x 10(6)/ml or more and the control patients. A positive correlation was observed between sperm concentration and seminal transferrin content (r = 0.56; p < 0.05). However, correlations between seminal transferrin concentration and sperm motility and between seminal plasma transferrin content and sperm morphology did not show any significance, nor did the seminal transferrin content correlate with plasma LH, FSH, prolactin or testosterone levels. It, therefore, seems that while transferrin is indicative of certain physiopathological conditions in the germ cells, this protein is not a distinctive marker of the fertility potential of an individual.     

Effect of smoking on seminal plasma ascorbic acid in infertile and fertile males

This work aimed to assess the relationship of seminal ascorbic acid levels with smoking in infertile males. One hundred and seventy men were divided into four groups: nonobstructive azoospermia [NOA: smokers (n = 20), nonsmokers (n = 20)]; oligoasthenozoospermia [smokers (n = 30), nonsmokers (n = 20)]; asthenozoospermia [smokers (n = 20), nonsmokers (n = 20)] and normozoospermic fertile men [smokers (n = 20), nonsmokers (n = 20)]. The patients underwent medical history, clinical examination, conventional semen analysis and estimation of ascorbic acid in the seminal plasma calorimetrically. There was a significant decrease in the mean seminal plasma ascorbic acid levels in smokers versus nonsmokers in all groups (mean +/- SD; 6.03 +/- 2.18 versus 6.62 +/- 1.29, 7.81 +/- 1.98 versus 9.44 +/- 2.15, 8.09 +/- 1.98 versus 9.95 +/- 2.03, 11.32 +/- 2.15 versus 12.98 +/- 12.19 mg dl(-1) respectively). Fertile subjects, smokers or not, demonstrated significant higher seminal ascorbic acid levels than any infertile group. Seminal plasma ascorbic acid in smokers and nonsmokers was correlated significantly with sperm concentration (r = 0.59, 0.60, P < 0.001), sperm motility (r = 0.65, 0.55, P < 0.001) and negatively with sperm abnormal forms per cent (r = -0.53, -0.50, P < 0.001). Nonsignificant correlations were elicited with semen volume (r = 0.2, 0.09) or liquefaction time (r = 0.03, 0.06). It is concluded that seminal plasma ascorbic acid decreased significantly in smokers and infertile men versus nonsmokers and fertile men, and is significantly correlated with the main sperm parameters: count, motility and normal morphology. Also, cigarette smoking is associated with reduced semen main parameters that could worsen the male fertilizing potential, especially in borderline cases.     

Interleukin-6 (IL-6) in seminal plasma of infertile men, and lipid peroxidation of their sperm

Concentrations of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) in seminal fluid, as well as levels of sperm lipid membrane peroxidation, were investigated in fertile and infertile men. Semen samples, obtained by masturbation from 37 infertile and 14 fertile men, were examined for the presence of TNF-alpha and IL-6. The level of lipid peroxidation of the sperm membrane was measured by determining malondialdehyde (MDA) formation. The correlation between the IL-6 and the TNF-alpha concentrations in seminal plasma with the levels of lipid peroxidation of the sperm membranes was statistically evaluated. The IL-6 concentration in seminal plasma of infertile men was significantly higher than that of fertile men (p < .05). Similarly, the level of membrane lipid peroxidation was higher for the semen of infertile men than that of fertile men (p < .001). A significant positive correlation was found between IL-6 levels in seminal plasma and membrane sperm lipid peroxidation (p < .002), but not between this parameter and TNF-alpha levels in seminal plasma. These findings suggest a possible association between IL-6 seminal plasma levels and lipid peroxidation of sperm membrane. Stimulation of reactive species production by human sperm and leucocytes, induced by the high levels of IL-6, could explain these results.     

Evaluation of reference values of standard semen parameters in fertile Egyptian men

The reference values of human semen, published in the WHO's latest edition in 2010, were lower than those previously reported. The objective of this study was to evaluate reference values of standard semen parameters in fertile Egyptian men. This cross‐sectional study included 240 fertile men. Men were considered fertile when their wives had recent spontaneous pregnancies with time to pregnancy (TTP) ≤12 months. The mean age of fertile men was 33.8 ± 0.5 years (range 20–55 years). The 5th percentiles (95% confidence interval) of macroscopic semen parameters were 1.5 ml for volume and 7.2 for pH. The 5th percentiles of microscopic parameters were 15 million/ml for sperm concentration, 30 million per ejaculate for total sperm count, 50% for total motility, 40% for progressive motility, 62% for vitality, 4% for normal sperm forms and 0.1 million/ml for seminal leucocyte counts. In conclusion , fertile Egyptian men had higher reference values of sperm total motility, progressive motility and vitality, and lower reference values for total sperm counts as compared to those determined by the latest edition of the WHO laboratory manual in 2010. Other semen parameters were identical to those defined by the WHO 2010 manual.