Establishment and evaluation of an automatic method for seminal plasma gamma-L-glutamyl transpeptidase detection / 中华男科学杂志

<p><b>OBJECTIVE</b>To establish an automatic method for seminal plasma gamma-L-glutamyl transpeptidase (GGT) detection and evaluate its accuracy, repeatability and linear range.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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%.</p><p><b>CONCLUSION</b>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.</p>

Advances in researches on polymorphonuclear neutrophil elastase in semen / 中华男科学杂志

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 / 中华男科学杂志

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>