Analysis of human sperm DNA fragmentation index (DFI) related factors: a report of 1010 subfertile men in China.

BACKGROUND: Many factors may lead to sperm DNA damage. However, it is little known that the correlations of sperm DNA damage with obesity-associated markers, and reproductive hormones and lipids levels in serum and seminal plasma. METHODS: In our prospective study, a total of 1 010 subfertile men, aged from 18 to 50 years old, were enrolled from August 2012 through June 2015. Their obesity-associated markers, semen parameters, sperm acrosomal enzyme activity, seminal plasma biochemical markers, and reproductive hormones and lipids levels in serum and seminal plasma were detected. Sperm DNA fragmentation index (DFI) was determined by sperm chromatin structure assay. The correlations between DFI and each of the above-mentioned variables were analyzed. RESULTS: Spearman correlation analysis showed that sperm DFI was positively related to age and abstinence time (P<0.001). Sperm DFI was also positively related to semen volume and percent of abnormal sperm head (P<0.001), while negatively related to sperm concentration, progressive motility (PR), sperm motility, total normal-progressively motile sperm count (TNPMS), percent of normal sperm morphology (NSM), percent of intact acrosome and acrosomal enzyme activity (P<0.001). Sperm DFI was positively related to seminal plasma zinc level (P<0.001) but unrelated to seminal plasma total α-glucotase, γ-glutamyl transpeptidase (GGT) and fructose levels. There was no any correlation between sperm DFI and obesity-associated markers such as body mass index (BMI), waist-to-hip ratio (WHR), waist circumference (WC) and waist-to-height ratio (WHtR), and serum lipids levels, but there was positive correlation between sperm DFI and seminal plasma triglyceride (TG) and total cholesterol (TC) levels (P<0.001). Sperm DFI was positively related to serum luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels and seminal plasma FSH and estradiol (E2) levels (P<0.001), but unrelated to serum and seminal plasma testosterone (T) levels. The multivariate regression analysis for the variables which were significantly correlated with sperm DFI in Spearman correlation analysis showed that age, semen volume, sperm concentration, progressive motility, TNPMS and intact acrosome were independently correlated with sperm DFI. CONCLUSIONS: There are many potential factors associated with sperm DFI, including age, abstinence time, spermatogenesis and maturation, seminal plasma lipids and reproductive hormones levels. However, the potential effects of seminal plasma lipids and reproductive hormones on sperm DNA damage need still to be demonstrated by the studies with scientific design and a large size of samples.

Accuracy Evaluation of The Depth of Six Kinds of Sperm Counting Chambers for both Manual and Computer-Aided Semen Analyses.

BACKGROUND: Although the depth of the counting chamber is an important factor influencing sperm counting, no research has yet been reported on the measurement and comparison of the depth of the chamber. We measured the exact depths of six kinds of sperm counting chambers and evaluated their accuracy. MATERIALS AND METHODS: In this prospective study, the depths of six kinds of sperm counting chambers for both manual and computer-aided semen analyses, including Makler (n=24), Macro (n=32), Geoffrey (n=34), GoldCyto (n=20), Leja (n=20) and Cell-VU (n=20), were measured with the Filmetrics F20 Spectral Reflectance Thin-Film Measurement System, then the mean depth, the range and the coefficient of variation (CV) of each chamber, and the mean depth, relative deviation and acceptability of each kind of chamber were calculated by the closeness to the nominal value. Among the 24 Makler chambers, 5 were new and 19 were used, and the other five kinds were all new chambers. RESULTS: The depths (mean ± SD, µm) of Makler (new), Macro and Geoffrey chambers were 11.07 ± 0.41, 10.19 ± 0.48 and 10.00 ± 0.28, respectively, while those of GoldCyto, Leja and Cell-VU chambers were 23.76 ± 2.15, 20.49 ± 0.22 and 24.22 ± 2.58, respectively. The acceptability of Geoffrey chambers was the highest (94.12%), followed by Macro (65.63%), Leja (35%) and Makler (20%), while that of the other two kinds and the used Makler chamber was zero. CONCLUSION: There existed some difference between the actual depth and the corresponding nominal value for sperm counting chambers, and the overall acceptability was very low. Moreover, the abrasion caused by the long use, as of Makler chamber, for example, may result in unacceptability of the chamber. In order to ensure the accuracy and repeatability of sperm concentration results, the depth of the sperm counting chamber must be checked regularly.

Relationship between Lipids Levels of Serum and Seminal Plasma and Semen Parameters in 631 Chinese Subfertile Men.

OBJECTIVE: This prospective study was designed to investigate the relationship between lipids levels in both serum and seminal plasma and semen parameters. METHODS: 631 subfertile men were enrolled. Their obesity-associated markers were measured, and semen parameters were analyzed. Also, seminal plasma and serum TC, TG, HDL and LDL and serum FFA, FSH, LH, total testosterone (TT), estradiol (E2) and SHBG levels were detected. RESULTS: Seminal plasma and serum TG, TC and LDL levels were positively related to age. Serum TC, TG and LDL were positively related to obesity-associated markers (P < 0.001), while only seminal plasma TG was positively related to them (P < 0.05). For lipids levels in serum and seminal plasma, only TG level had slightly positive correlation between them (r = 0.081, P = 0.042). There was no significant correlation between serum lipids levels and semen parameters. However, seminal plasma TG, TC, LDL and HDL levels were negatively related to one or several semen parameters, including semen volume (SV), sperm concentration (SC), total sperm count (TSC), sperm motility, progressive motility (PR) and total normal-progressively motile sperm counts (TNPMS). Moreover, seminal plasma TG, TC, LDL and HDL levels in patients with oligospermatism, asthenospermia and teratozoospermia were higher than those with normal sperm concentration, motility or morphology. After adjusting age and serum LH, FSH, TT, E2 and SHBG levels, linear regression analysis showed that SV was still significantly correlated with seminal plasma LDL (P = 0.012), both of SC and TSC with seminal plasma HDL (P = 0.028 and 0.002), and both of PR and sperm motility with seminal plasma TC (P = 0.012 and 0.051). CONCLUSION: The abnormal metabolism of lipids in male reproductive system may contribute to male factor infertility.

A Pilot Comparative Study of 26 Biochemical Markers in Seminal Plasma and Serum in Infertile Men.

INTRODUCTION: The relationships of the biochemical components in seminal plasma and serum, and their origins and physiological effects in male reproductive system have been poorly understood. METHODS: Based on the calibration and quality control measures, 26 biochemical markers, in seminal plasma and serum samples from 36 male infertility patients with nonazoospermia were detected and compared. RESULTS: Only PA was undetectable in all seminal plasma samples. There were significant differences of all other 24 biochemical markers in seminal plasma and serum (P < 0.05) except for UA (P = 0.214). There were rich proteins in seminal plasma, and globulin accounted for about 90%. There were also abundant enzymes in seminal plasma, and the activities of ALT, AST, AKP, GGT, LDH, CK, and αHBDH in seminal plasma were significantly higher than those in serum while ADA was inversely lower. There were relatively low levels of Glu, TG, TC, and hsCRP in seminal plasma, but Glu was undetectable in 8 of 36 cases. CONCLUSIONS: The differences of the levels of biochemical markers in seminal plasma and serum might be associated with the selective secretion of testis, epididymis and male accessory glands, and the specific environment needed for sperm metabolism and function maintenance.

[Correlations of 24 biochemical markers in seminal plasma with routine semen parameters].

OBJECTIVE: To investigate the correlations of 24 biochemical markers in the seminal plasma with routine semen parameters. METHODS: According to the WHO5 standards, we analyzed the routine semen parameters of 66 subfertile men, including the semen volume, sperm concentration, total sperm count, sperm motility, and the percentage of progressively motile sperm (PR). Based on the calibration and quality control measures and using an automatic biochemistry analyzer or electrolyte analyzer, we detected 24 biochemical markers in the seminal plasma of the patients, including total protein (TP), albumin (Alb), globulin (Glb), uric acid (UA), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (AKP), γ-glutamyltransferase (GGT), lactate dehydrogenase (LDH), creatine kinase (CK), alpha hydroxybutyrate dehydrogenase (αHBDH), adenosine deaminase (ADA), glucose (Glu), triglyeride (TG), total cholesterol (TC), urea nitrogen (UN), creatinine (Cr), high-sensitive C-reactive protein (hsCRP), K+, Na+, Cl- , Ca, Mg, and phosphorus (P). Then we analyzed the correlations of the 24 biochemical markers with routine semen parameters. RESULTS: The levels of the TP, Alb, and Glb proteins in the seminal plasma were positively correlated with sperm concentration, so was that of Alb with the total sperm count, and the AST and LDH activities with sperm concentration and total sperm count. The AKP activity in the seminal plasma was correlated negatively with the semen volume, but positively with sperm motility. The αHBDH activity exhibited a positive correlation with both sperm concentration and total sperm count, with a coefficient of correlation (r) above 0.7. The UN level was correlated negatively with the semen volume, so was the Cr level with the semen volume, sperm concentration, and total sperm count, and the Glu level with sperm concentration and total sperm count. The TG level was correlated positively with the semen volume, but negatively with sperm motility. The levels of seminal plasma ALT, GGT, ADA, UA, TC, CK, and hsCRP showed no correlation with the above-mentioned semen parameters. None of the seminal plasma K+, Na+, Ca, Mg, and P levels was found correlated with semen parameters except the Cl- level, which was negatively correlated with the semen volume. CONCLUSION: Many biochemical markers in the seminal plasma are closely related to routine semen parameters, indicating that these biochemical components may play roles in spermatogenesis, sperm maturation, and physiological metabolism.

[Establishment and evaluation of an automatic method for seminal plasma gamma-L-glutamyl transpeptidase detection].

OBJECTIVE: To establish an automatic method for seminal plasma gamma-L-glutamyl transpeptidase (GGT) detection and evaluate its accuracy, repeatability and linear range. METHODS: We detected the GGT activity in the seminal plasma by rate assay, and established the detection parameters on an automatic biochemical analyzer. Then, we evaluated the reagent blank absorbance, accuracy, repeatability and linear range of the automatic method, and compared the results obtained from the method and the seminal plasma GGT detection kit (Xindi Biological Pharmaceutical Engineering Co., Ltd, Nanjing, China) commonly used in clinical laboratories. RESULTS: The average absorbance of reagent blank was 0.0476, and the average change rate of blank absorbance (deltaA/min) was 0.000168. The coefficients of variation (CV) for 3 seminal plasma samples with high, middle and low GGT activity detected for 10 times, respectively, were 0.26%, 4.83% and 1.60%. The accuracy of the automatic method was evaluated by a comparison test, and the relative deviation for each concentration point of 40 seminal plasma samples ranged from 13.38% to 11.05%, which met the requirement of < 15%. There was a good linear relationship (r > 0.99) when the seminal plasma GGT activity was between 299 and 1 833 U/L. A significant positive correlation was found between the seminal plasma GGT detection kit (a colorimetric method) as the control and the automatic method as the test reagent in the results of 115 seminal plasma samples (r = 0.981, P < 0.01), with a Kappa value of 0.776 (P < 0.05) and a coincidence rate of 90.43%. CONCLUSION: The established automatic method to detect seminal plasma GGT activity has a low reagent blank, good repeatability and accuracy, and fine concordance with the colorimetric method commonly used in clinical laboratories. It is simple, rapid and suitable for screening large numbers of samples, avoids the necessity of diluting the seminal plasma sample, and saves a lot of manpower and reagents.

[Influence of the depth of the sperm counting chamber on sperm motility].

OBJECTIVE: To investigate the influence of the depth of the sperm counting chamber on sperm motility. METHODS: We measured the depths of sperm counting chambers using the Filmetrics F20 Spectral Reflectance Thin-Film Measurement System. Then, according to the WHO5 manual, we analyzed 36 semen samples for the percentages of progressively motile sperm (PR) and non-progressively motile sperm (NP) and sperm motility (PR + NP) with the Ruiqi CFT-9201 computer-aided sperm analysis system, and compared the results of analysis. RESULTS: The depths of the 4 sperm counting chambers were 9.8, 12.7, 15.7 and 19.9 microm, respectively, and the obtained PR were (44.00 +/- 11.63), (41.96 +/- 12.62), (40.86 +/- 11.71) and (37.78 +/- 11.38)%, NP (13.54 +/- 3.01), (14.13 +/- 2.94), (14.91 +/- 3.02) and (16.53 +/- 2.77)%, and sperm motility (57.53 +/- 11.06), (56.08 +/- 11.97), (55.78 +/- 11.55) and (54.31 +/- 12.11)% from the 4 chambers, respectively. The depth of the sperm counting chamber was correlated negatively with PR (r = -0.993, P < 0.05) and sperm motility (r = -0.978, P < 0.05), but positively with NP (r = 0.989, P < 0.05). There were statistically significant differences between the 9.8 microm and 19.9 microm deep chambers in PR and NP (P < 0.05) though not in sperm motility among the 4 chambers of different depths. CONCLUSION: The impact of the depth of the sperm counting chamber on sperm motility should not be ignored, for the deviation of the results from the chambers of different depths may lead clinicians to incorrect diagnosis and consequently inappropriate therapeutic approaches. Different reference ranges of sperm motility need to be normalized in correspondence to the depths of sperm counting chambers.

[Advances in researches on polymorphonuclear neutrophil elastase in semen].

Reproductive tract infection is one of the important factors of male reproduction. Polymorphonuclear neutrophil elastase (PMNE) in semen, as a marker of male reproductive tract inflammation, especially recessive infection, potentially affects male fertility. The concentration of PMNE in semen is correlated significantly not only with semen white blood cell count and seminal plasma ROS level, but also with the levels of other inflammation related cytokines, such as IL-6, IL-8, and TNF-alpha. Furthermore, PMNE has a negative impact on sperm quality by decreasing sperm motility, increasing the percentage of morphologically abnormal sperm and interfering with DNA integrity. PMNE inhibitors in semen can form a compound with PMNE, and the imbalanced proportions of the two may promote the development of chronic inflammation, and consequently lead to male infertility. At present, PMNE in semen is detected mainly by enzyme immunoassay, but this method still needs to be standardized, and the diagnostic standards to be unified.

[Preparation and identification of recombinant human neutrophil elastase].

OBJECTIVE: To prepare a purified recombinant human neutrophil elastase (HNE) using genetic engineering technology, and pave the way for the preparation of the antibody to HNE and establishment of semen HNE detection methods. METHODS: HNE mRNA was obtained from human peripheral blood granulocytes with specific HNE primers, and the cDNA of HNE was cloned into the plasmid pGEX-2T to derive a recombinant plasmid pGEX-2T/HNE. After PCR identification, double-enzyme digestion and gene sequencing, the recombinant plasmid was transferred into competent Escherichia coli DH5alpha and further induced to express the recombinant fusion protein GST/HNE by isopropyl beta-D-thiosulfate galactosidase (IPTG). The recombinant fusion protein was cleaved by thrombin and further purified with glutathione agarose beads to obtain purified recombinant HNE. RESULTS: The recombinant plasmid pGEX-2T/HNE was successfully prepared and transferred into E. coli DH5o; the expression of the recombinant fusion protein GST/ HNE was successfully induced by IPTG at 18 degrees C overnight; and the purified recombinant protein HNE was successfully obtained by thrombin cleavage and purification of glutathione agarose beads. CONCLUSION: The acquirement of purified recombinant HNE has prepared the ground for the preparation of the antibody to HNE and establishment of semen HNE detection methods.