[An analysis of donor semen quality in Chongqing Human Sperm Bank].

OBJECTIVE: To evaluate the quality of the donor semen in Chongqing Human Sperm Bank and the influence of age on semen parameters. METHODS: We collected semen samples from 899 donors in Chongqing Human Sperm Bank and divided them into five groups according to the age of the semen donors: 22－25, 26－30, 31－35, 36－40, and >40 years old. Using the Makler Counting Chamber, we measured the semen volume, percentage of progressively motile sperm (PMS), total motile sperm, sperm concentration, total sperm count per ejaculate, and percentage of morphologically normal sperm (MNS). Then, we compared the semen parameters obtained with the fifth percentile and median reference values published in the WHO Laboratory Manual for the Examination and Processing of Human Semen-5th Ed (WHO 5th Ed) and among different age groups using the Kruskall-Wallis H test. RESULTS: The semen volume (1.8 ml), sperm concentration (25.0 × 106/ml), total sperm count (100.7 × 106/ejaculate) and MNS (4.3%) in the semen samples of the 899 donors were obviously higher than the fifth percentile values published in the WHO 5th Ed, and so were the first three parameters (4.0 ml, 88.0 × 106/ml, and 333.7 × 106/ejaculate) than the WHO median reference values. PMS (31.0%) and total motile (38.0%) were lower than the WHO fifth percentile values and so was MNS (11.6%) than the WHO median reference value. PMS (55.0%) and total motile sperm (61.0%), however, were coincident with the median reference values of WHO 5th Ed. Statistically significant differences were observed among the 22－25, 26－30, 31－35, 36－40 and >40 years old groups in perm concentration (88.0 ï¼»1.0－270.0ï¼½ vs 96.0 ï¼»5.0－335.0ï¼½ vs 100.0 ï¼»3.0－200.0ï¼½ vs 105 ï¼»15.0－225.0ï¼½ vs 90.0 ï¼»22.0－159.0ï¼½ × 106/ml, P < 0.05), but not in the semen volume, PMS, total sperm motility, total sperm count or MNS (P > 0.05). CONCLUSIONS: The donor semen in Chongqing Human Sperm Bank is generally of high quality. Sperm concentration significantly increases with age but decreases in men aged >40 years.

[Bacterial culture of donor semen: Analysis of results].

OBJECTIVE: To investigate bacterial infection and the distribution of different bacterial species in the donor semen and the influence of different bacterial counts on semen quality. METHODS: Bacterial colonies in the semen samples from 1 126 donors were counted with the Synbiosis Protocol 3 Automatic Colony Counter and the bacterial species with a colony count ≥104 cfu/ml identified with the VITEK2 Compact Automatic Biochemical Analyzer. The Makler Sperm Counting Board was used to examine the semen quality of the semen samples with a colony count = 0 cfu/ml (n = 22, group A), those with a colony count <104 cfu/ml (n = 22, group B) and those with a colony count ≥104 cfu/ml (n = 22, group C). Univariate analysis was employed for comparison of semen quality among different groups. RESULTS: Among the 1 126 donor semen samples cultured, 5 (0.44%) showed mixed bacterial contamination and 993 (88.58%) showed none but with growth of a certain species of bacteria, 2.22% (22/993) with a colony count ≥104 cfu/ml, mainly including Streptococcus bovis, tiny bacilli, Staphylococcus epidermis, and Staphylococcus aureus, among which gram-positive and gram-negative bacteria accounted for 95.45% (21/22) and 4.54% (1/22), respectively. Compared with group A, groups B and C manifested significantly reduced total sperm count (ï¼»567.5 ± 327.6ï¼½ vs ï¼»421.9 ± 155.9ï¼½ and ï¼»389.9 ± 110.6ï¼½ × 106 per ejaculate, P <0.05) and percentage of progressively motile sperm (ï¼»65.0 ± 6.5ï¼½ vs ï¼»61.0 ± 3.5ï¼½ and ï¼»61.6 ± 4.3ï¼½ %, P <0.05). There were no statistically significant differences among the three groups in the semen liquefaction time, semen pH value, total sperm motility or percentage of morphologically normal sperm (P > 0.05). Of the 284 randomly selected semen samples, 34 (11.97%) were found positive for Ureaplasma urealyticum (UU) and no significant difference was observed in the semen quality between the UU-positive and UU-negative samples (P> 0.05). CONCLUSIONS: The bacteria-positive rate is high in the donor semen and the bacterial species are varied, mainly including gram-positive bacteria. Semen quality is reduced with the increased number of bacterial colonies.

[Analysis of the quality of cryopreserved semen from male cancer patients].

OBJECTIVE: To investigate the semen quality of cancer patients and search for a better way of sperm cryopreservation for them. METHODS: We retrospectively analyzed the quality of the semen from 43 cancer patients under cryopreservation in the Sperm Bank of Zhejiang Province, and compared the semen parameters between the cancer patients and 248 normal donors as well as between the testicular cancer cases (n=22) and non-testicular cancer cases (n=21). RESULTS: The cancer patients exhibited significantly lower semen quality than the normal donors as in sperm concentration (60.90 x 10(6)/ml vs 74.27 x 10(6)/ml), progressive motility (41.07% vs 51.79%), and recovery rate (49.98% vs 57.33%) (all P <0.05). Furthermore, the progressive sperm motility and sperm recovery rate after freezing were significantly decreased in the testicular cancer cases (15.68% and 42.81%) than in the non-testicular cancer cases (28.36% and 57.53%) (both P <0.05). CONCLUSION: Semen quality declines in cancer patients, and therefore early sperm cryopreservation is essential for them. Due to the poor sperm motility and recovery rate of testicular cancer patients after freezing, further investigation is required on the improvement of sperm cryopreservation methods.

CFTR is essential for sperm fertilizing capacity and is correlated with sperm quality in humans.

BACKGROUND: Our previous studies have demonstrated the cystic fibrosis transmembrane conductance regulator (CFTR) is important for capacitation and male fertility in mouse and guinea pig spermatozoa. However, the exact function of CFTR on human sperm fertilizing capacity, and correlation with sperm quality has not been established. The present study may shed light on some unexplained male infertility, and on a possible new method for diagnosis of male infertility and strategy for male contraception. METHODS: To assess the effect of CFTR on human sperm fertilizing capacity, we examined sperm capacitation and the acrosome reaction using chlortetracycline staining, analyzed sperm hyperactivation by computer-assisted semen analysis (CASA), measured intracellular cAMP levels using ElA and evaluated sperm penetration of zona-free hamster eggs assay in fertile men. The percentage of spermatozoa expressing CFTR from fertile, healthy and infertile men (mainly teratospermic, asthenoteratospermic, asthenospermic and oligospermic) was conducted by indirect immunofluorescence staining. RESULTS: Progesterone significantly facilitated human sperm capacitation and ZP3 triggered the acrosome reaction, both were significantly inhibited by CFTR inhibitor-172 (CFTRinh-172; 10 nM-1 microM) in a dose-dependent manner. The presence of 100 nM CFTRinh-172 markedly depressed intracellular cAMP levels, sperm hyperactivation and sperm penetration of zona-free hamster eggs. In addition, the percentage of spermatozoa expressing CFTR in the fertile men was significantly higher than healthy and infertile men categories (P < 0.01). CONCLUSIONS: CFTR is essential for human sperm fertilizing capacity and the impairment of CFTR expression in spermatozoa is correlated with a reduction of sperm quality. These results suggest that defective expression of CFTR in human sperm may lead to the reduction of sperm fertilizing capacity.

Seasonal variation in semen quality in China.

In this study, we assessed the effect of seasonal variation on the semen quality in Chinese by using the average highest temperature (AHT) of the ejaculation day for partitioning season periods. A total of 13 635 semen samples were collected and analysed according to the AHT of the ejaculation day. Semen volume, sperm concentration and the percentage of spermatozoa with normal morphology in midsummer (AHT > 30 °C) were significantly lower than those in other periods of the year. Sperm motility with AHT 10-20 °C in winter and spring was significantly higher than that in other seasons. The percentage of head defects spermatozoa with AHT < 10 °C in winter was significantly lower than that in other periods. We observed that there was a significant effect of season on the semen parameters. Highest environment temperature of the day may be a determining factor for the seasonal variations in semen quality.