Standardization and quality control for the determination of alpha-glucosidase in seminal plasma

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.

A survey on the status of semen analysis in 118 laboratories in China

Collecting baseline information on how laboratories perform testing is a reasonable first step towards establishing intra- and inter-laboratory standardization and quality control for semen analysis. We carried out a survey of the laboratories performing the testing in Mainland China. A questionnaire, composed of 36 questions covering all aspects of semen analysis, was designed, and a copy was distributed to each of the 145 laboratories. Of these, 118 laboratories completed the questionnaires. The survey results showed that semen volume was measured visually in 53.6% (59/110) of the responding laboratories, and 70.9% (73/103) of laboratories analysed incompletely liquefied semen without any treatment. In addition, both manual-microscopic and computer-assisted semen-analysis systems were applied to analyse sperm concentration, motility and morphology. However, more than five methods were employed in routine sperm staining. An enzyme-linked immunosorbent assay was commonly used for determining whether antisperm antibodies were present. Several seminal biochemical markers were analysed in only 27.1% (32/118) of the responding laboratories. Generally, there was a lack of intra- and inter-laboratory quality control measures for semen analysis in all laboratories responding to this survey. In conclusion, the methods of semen analysis and the interpretation of test results in the surveyed laboratories differed markedly. In particular, many laboratories employed methods other than those recommended by the World Health Organization Laboratory Manual for the Examination of Human Semen and Spermcervical Mucus Interaction (1999). These findings suggest an urgent need for the standardization of semen analysis with acceptable quality controls for each parameter to make the results repeatable and meaningful.

Preliminary investigations on the standardisation and quality control for the determination of ?-glutamyltranspeptidase activity in seminal plasma

The present study was designed to assess the effects of centrifugation velocity, standing time after dilution, freezing-thawing and chymotrypsin on the determination of gamma-glutamyltranspeptidase (gamma-GT) activities in seminal plasma, and to establish an instruction for the standardisation and quality control for the determination of gamma-GT within the same laboratory and among different laboratories. The gamma-GT level and sperm concentration of each of 72 samples of seminal plasma obtained by centrifugation at 1000 g for 10 min or 3000 g for 15 min were assayed. In addition, gamma-GT activities in diluted seminal plasma with different standing time and in samples with or without chymotrypsin were measured. The results showed that there was a significant difference of gamma-GT levels in seminal plasma obtained by centrifugation at different velocities (P < 0.001), and that gamma-GT activities in seminal plasma measured after standing for 30 min after dilution were notably lower than those measured immediately after dilution (P < 0.001). However, the data indicated that both chymotrypsin and freezing-thawing had no apparent effect on the determination of seminal gamma-GT. In conclusion, standing time after dilution and centrifugation velocity should be standardised, and frozen seminal plasma could serve as quality control products for the determination of gamma-GT activity among different laboratories.