Insufficiency of Mrpl40 disrupts testicular structure and semen parameters in a murine model.

Approximately 31% of patients with 22q11.2 deletion syndrome (22q11.2DS) have genitourinary system disorders and 6% of them have undescended testes. Haploinsufficiency of genes on chromosome 22q11.2 might contribute to the risk of 22q11.2DS. In this study, we used mice with single-allele deletion in mitochondrial ribosomal protein L40 (Mrpl40 +/- ) as models to investigate the function of Mrpl40 in testes and spermatozoa development. The penetrance of cryptorchidism in Mrpl40 +/- mice was found to be higher than that in wild-type (WT) counterparts. Although the weight of testes was not significantly different between the WT and Mrpl40 +/- mice, the structure of seminiferous tubules and mitochondrial morphology was altered in the Mrpl40 +/- mice. Moreover, the concentration and motility of spermatozoa were significantly decreased in the Mrpl40 +/- mice. In addition, data-independent acquisition mass spectrometry indicated that the expression of genes associated with male infertility was altered in Mrpl40 +/- testes. Our study demonstrated the important role of Mrpl40 in testicular structure and spermatozoa motility and count. These findings suggest that Mrpl40 is potentially a novel therapeutic target for cryptorchidism and decreased motility and count of spermatozoa.

[Impact of the freezing-thawing process on human sperm mitochondria].

OBJECTIVE: To study the structure and function of human sperm mitochondria before and after the freezing-thawing process. METHODS: Human sperm from healthy donors were subjected to the slow freezing-thawing process, and the sperm mitochondrion-related indexes compared before and after cryopreservation. The ultrastructural changes of the mitochondria were observed under the projection electron microscope, the mitochondrial membrane potential (MMP) and seminal adenosine triphosphate (ATP) content measured by immunofluorescence labeling and ELISA, respectively, and the sperm oxidative stress related indexes detected before and after sperm cryopreservation. RESULTS: Electron microscopy showed loose structures and widened crests of the sperm mitochondria, some with vacuole-like changes after the freezing-thawing process. The sperm after cryopreservation, compared with those before it, exhibited significantly increased contents of oxygen free radicals (ï¼»11.6 ± 3.8ï¼½% vs ï¼»9.6 ± 4.1ï¼½%, P < 0.05) and malondialdehyde (ï¼»3.2 ± 1.4ï¼½ vs ï¼»2.3 ± 1.2ï¼½ nmol/108, P < 0.05), but decreased antioxidant capacity (ï¼»0.6 ± 0.4ï¼½ vs ï¼»0.9 ± 0.4ï¼½ nmol/108, P < 0.05), superoxide dismutase activity (ï¼»0.9 ± 0.4ï¼½ vs ï¼»9.1 ± 3.9ï¼½ nmol/108, P < 0.05), MMP (ï¼»52.2 ± 6.2ï¼½% vs ï¼»55.7 ± 4.9ï¼½%, P = 0.026) and ATP production (ï¼»56.5 ± 9.0ï¼½ vs ï¼»61.3 ± 10.4ï¼½ pmol/106, P = 0.014). CONCLUSIONS: The freezing-thawing process can cause ultrastructural disorder of human sperm mitochondria, reduce their membrane potential and decrease their ATP production.

[Status quo of autologous sperm preservation in the human sperm bank in Beijing].

OBJECTIVE: To comprehensively analyze the status quo of autologous sperm preservation in the human sperm bank in Beijing and better utilize the existing resources for the preservation of male fertility. METHODS: We retrospectively analyzed the geographical data and semen quality of 251 males with autologous sperm preservation in the Human Sperm Bank, Science and Technology Research Institute, National Health and Family Planning Commission of China from July 2006 to December 2016. RESULTS: The rate of autologous sperm preservation in the Human Sperm Bank was as low as 8.76% between July 2006 and December 2010 but increased annually by 119% on average from 2011 to 2013. Of the 251 males involved, 204 (81.27%) were aged 20－39 years, 175 (69.72%) had bachelor's or master's degree, 223 (88.84%) had no child, 69 (27.49%) got less than 10 tubes of semen samples frozen, and 26 (10.36%) had their semen samples cryopreserved only once. The utilization rate of the cryopreserved sperm was only 5.58 % (n = 14). The main reason for autologous sperm preservation was carcinoma (55.78% ï¼»n = 140ï¼½), including blood cancer (22.31% ï¼»n = 66ï¼½), testicular cancer (13.15% ï¼»n = 33ï¼½) and other cancers (16.33% ï¼»n = 41ï¼½). Compared with the non-cancer males, the cancer patients had a significantly reduced mean sperm concentration (90.45 vs 60.53 ×106/ml, P < 0.05), total sperm count (311.3 vs 175.8 ×106, P < 0.05), percentage of progressively motile sperm (PMS) (49.21% vs 43.55%, P < 0.05) and recovery rate of PMS (68.13% vs 52.17%, P < 0.05). In the subgroups of testicular, blood and other cancers, the sperm concentration averaged 37.68, 57.98 and 90.69 ×106/ml, the semen volume 2.73, 2.82 and 3.41 ml, the total sperm count 93.29, 158.41 and 349.49 ×106, the percentage of PMS 45.32%, 43.47% and 44.49%, and the recovery rate of PMS 48.32%, 50.07% and 61.09%, respectively, the sperm concentration and total sperm count significantly lower in the testicular cancer patients than in the other two groups (P < 0.05). CONCLUSIONS: The number of the cases of autologous sperm preservation in Beijing is increasing year by year, and the majority of them are cancer patients. As most of the cancer patients have missed the best period for sperm preservation, sperm bank workers should endeavor to increase the public awareness of autologous sperm preservation.

Obesity impairs male fertility through long-term effects on spermatogenesis.

OBJECTIVE: This study aimed to investigate the effect and possible underlying mechanisms of high-fat diet-induced obesity on spermatogenesis in male rats. METHODS: A total of 45 male rats were randomly divided into control (n = 15, normal diet) and obesity groups (n = 30, high-fat diet) and were fed for 16 weeks. Body weight and organ indexes were determined after sacrifice. Indicators of reproductive function, including sperm count, sperm motility, apoptosis of spermatogenic cells, and oxidative stress levels, were measured. Serum metabolic parameters and reproductive hormones were also assayed. RESULTS: Compared with the control group, epididymal sperm motility in the obese rats was significantly decreased (P < 0.01). Morphological analysis of the obesity group showed vacuolar changes in seminiferous tubules, spermatogenic cell dysfunction, and increased apoptosis of spermatogenic cells in testicular tissue (P < 0.05). The calculated free testosterone (cFT) concentration in serum was decreased (P < 0.05), whereas the serum sex hormone-binding globulin (SHBG) level was significantly increased (P < 0.01). The superoxide dismutase (SOD) concentration decreased and the malondialdehyde (MDA) concentration increased in testis tissues; however, neither changes were statistically significant (P > 0.05). RESULTS: Nutritional obesity can damage spermatogenesis in male rats due to long-term effects on spermatogenesis.

[Levels of serum reproductive hormones and metabolic syndrome in adult males].

OBJECTIVE: To investigate the prevalence of metabolic syndrome (MS) and its relationship with reproductive hormones in adult males in China. METHODS: Using the cluster and stratified sampling methods, we conducted an investigation among 3 600 adult males aged over 20 years in Hebei, Shaanxi and Jiangsu provinces. We obtained their reproductive hormone levels, biochemical indicators and basic body indexes and compared them between the two groups of subjects. RESULTS: A total of 3 332 valid serum samples were collected, which revealed a prevalence rate of MS of 38.5% in the adult males. Compared with the non-MS subjects, the MS males showed a significantly higher free testosterone index (FTI, 0.39 ± 0.15 vs 0.45 ± 0.19, P < 0.01) but lower levels of total testosterone (TT, ï¼»16.35 ± 4.78ï¼½ vs ï¼»13.37 ± 4.23ï¼½ nmo/L, P < 0.01) and sex hormone-binding globulin (SHBG, ï¼»47.13 ± 20.50ï¼½ vs ï¼»33.32 ± 14.91ï¼½ nmol/L, P < 0.01) and testosterone secretion index (TSI, 3.64 ± 1.92 vs 3.14 ± 1.80, P < 0.01). There were no statistically significant differences between the two groups in the levels of calculated free testosterone (cFT) and LH (P > 0.05). Spearman rank correlation analysis showed that the levels of serum TT and SHBG were correlated with all the indicators of MS (P < 0.01) except systolic blood pressure (SBP), while that of cFT only with the levels of high-density lipoprotein (HDL), fasting blood glucose (FBG) and SBP (P < 0.01). After adjusted for age, smoking, drinking, and body mass index (BMI), all the MS indicators were significantly associated with the SHBG level (P < 0.01), but not high blood pressure with the serum TT level (P > 0.05). After adjusted for the age, smoking, drinking, BMI and TT, the serum SHBG level was the main independent risk factor for MS (OR: 0.965, 95% CI: 0.958－0.973, P < 0.01). CONCLUSIONS: The level of serum cFT is not correlated with while that of SHBG is the main independent risk factor for metabolic syndrome in adult males in China.

[Protective effect of Qilin Pills on the reproductive function of oligoasthenospermia rats].

OBJECTIVE: To study the protective effect of Qilin Pills (QLP) on the reproductive function of rats with oligoasthenospermia (OAS) induced by tripterygium glycosides. METHODS: Twenty-eight male SD rats were randomly divided into a normal control, an OAS model control, a low-dose QLP, and a high-dose QLP group of equal number. OAS models were made in the latter three groups by intragastrical administration of tripterygium glycosides at 40 mg per kg of the body weight per day, and meanwhile the animals in the low- and high-dose QLP groups were treated with QLP at 1.62 and 3.24 g per kg of the body weight per day, respectively, while those in the OAS model group with normal saline, all for 30 consecutive days. Then all the rats were executed for obtaining the testis weight, testis viscera index, epididymal sperm concentration and motility, reproductive hormone levels, and antioxidation indexes and observation of the histomorphological changes of the testis tissue by HE staining. RESULTS: After 30 days of intervention, the low- and high-dose QLP groups, as compared with the OAS model controls, showed significantly improved epididymal sperm concentration (ï¼»14.57 ± 3.95ï¼½ and ï¼»39.71 ± 11.31ï¼½ vs ï¼»4.71 ± 1.25ï¼½ ×106/ml, P <0.05) and motility (ï¼»3.71 ± 1.11ï¼½ and ï¼»4.29 ± 1.80ï¼½ vs ï¼»0.57 ± 0.53ï¼½%, P <0.05), increased levels of sex hormone binding globulin (SHBG) (ï¼»94.83 ± 11.17ï¼½ and ï¼»88.05 ± 9.21ï¼½ vs ï¼»56.74 ± 8.29ï¼½ nmol/L, P <0.05) and free testosterone (FT) (ï¼»27.27 ± 3.63ï¼½ and ï¼»32.80 ± 2.51ï¼½ vs ï¼»22.81 ± 2.75ï¼½ nmol/L, P <0.05), decreased level of follicle-stimulating hormone (FSH) (ï¼»1.49 ± 0.62ï¼½ and ï¼»1.12 ± 0.83ï¼½ vs ï¼»1.71 ± 0.52ï¼½ mIU/ml, P <0.05), but no significant change in the total testosterone (TT) level. Meanwhile, the level of superoxide dismutase (SOD) was markedly elevated in the low- and high-dose QLP groups in comparison with the OAS model control group (ï¼»277.14 ± 15.84ï¼½ and ï¼»299.60 ± 20.83ï¼½ vs ï¼»250.04 ± 31.06ï¼½ U/ml, P <0.05) while that of reactive oxygen species (ROS) remarkably reduced (ï¼»397.61 ± 62.71ï¼½ and ï¼»376.84 ± 67.14ï¼½ vs ï¼»552.20 ± 58.07ï¼½ IU/ml, P <0.05). HE staining showed that QLP intervention significantly increased the layers and quantity of spermatogenic cells in the testicular seminiferous tubules of the OAS rats. CONCLUSIONS: QLP can effectively protect the reproductive system of oligoasthenospermia rats by raising sperm quality, elevating reproductive hormone levels, reducing oxidative stress injury, and improving histomorphology of the testis.

[Serum homocysteine and metabolic syndrome in middle-aged and elderly men].

OBJECTIVE: To investigate the relationship among serum reproductive hormone levels, serum homocysteine (Hcy) levels, metabolic syndrome (MS), and the components of MS in middle-aged and elderly males. METHODS: Using the cluster and stratified sampling methods and a unified structured questionnaire, we conducted a survey among 948 men aged 40 - 80 years in the rural community, measured their basic physical parameters, and obtained their reproductive hormone levels, serum Hcy concentrations, and metabolism-related indicators. We collected 868 valid questionnaires along with their serum samples, divided the subjects into an MS and a non-MS control group in a 1:1 ratio, and measured their serum Hcy concentrations. RESULTS: Among the subjects included, 132 were diagnosed with MS. Nonparametric tests showed statistically significant differences between the MS and non-MS groups in the waist circumference (WC), waist-hip ratio (WHR), body mass index (BMI), systolic blood pressure (SBP), and diastolic blood pressure (DBP) (P < 0.05), but not in age (P > 0.05). Significant differences were also observed between the two groups in the levels of serum tT, SHBG, LH, and FTI (P < 0.05) , but not in the concentrations of serum Hcy (P > 0.05). The concentration of serum Hcy exhibited no correlation with BMI, SBP, DBP, FBG, TG, and HDL-C (P > 0.05) and had no influence on MS. CONCLUSION: The concentration of serum Hcy is not significantly correlated with MS, nor with its components. The levels of male serum reproductive hormones are associated both with MS and with its components.

Is serum sex hormone-binding globulin a dominant risk factor for metabolic syndrome?

This multi-center, cross-sectional study investigated the association between serum testosterone (T) levels, serum sex hormone-binding globulin (SHBG) levels, and the risk of metabolic syndrome (MS) in 3332 adult Chinese men. The prevalence of MS was 34.7%, and men with MS had lower serum levels of total T (TT) and SHBG than those without MS (P < 0.001). There was no significant difference in serum free T (FT) levels between subjects with and without MS (P = 0.627). In logistic regression analysis, the association between MS and serum SHBG levels persisted after adjusting for age, body mass index (BMI), smoking and drinking status, and serum TT (odds ratio [OR] 0.962, 95% confidence interval [95% CI] 0.954-0.969, P< 0.01). However, the association between serum TT level and the risk of MS was weak after adjusting for age, BMI, SHBG level, and smoking and drinking status (OR 0.981, 95% CI 0.960-1.007). Our study reveals that both serum TT and SHBG levels, but not serum FT, are inversely associated with the prevalence of MS and that serum SHBG is an independent and dominant risk factor for MS.

A randomized, controlled, multicenter contraceptive efficacy clinical trial of the intravas device, a nonocclusive surgical male sterilization.

Because of unavoidable complications of vasectomy, this study was undertaken to assess the efficacy and safety of male sterilization with a nonobstructive intravas device (IVD) implanted into the vas lumen by a mini-surgical method compared with no-scalpel vasectomy (NSV). IVDs were categorized into two types: IVD-B has a tail used for fixing to the vas deferens (fixed wing) whereas IVD-A does not. A multicenter prospective randomized controlled clinical trial was conducted in China. The study was comprised of 1459 male volunteers seeking vasectomy who were randomly assigned to the IVD-A (n = 487), IVD-B (n = 485) or NSV (n = 487) groups and underwent operation. Follow-up included visits at the 3 rd -6 th and 12 th postoperative months. The assessments of the subjects involved regular physical examinations (including general and andrological examinations) and semen analysis. The subjects' partners also underwent monitoring for pregnancy by monthly interviews regarding menstruation and if necessary, urine tests. There were no significant differences in pregnancy rates (0.65% for IVD-A, 0 for IVD-B and 0.21% for NSV) among the three groups (P > 0.05). The cumulative rates of complications at the 12 th postoperative month were zero, 0.9% and 1.7% in the three groups, respectively. In conclusion, IVD male sterilization exhibits a low risk of long-term adverse events and was found to be effective as a male sterilization method, similar to the NSV technique. IVD male sterilization is expected to be a novel contraceptive method.

[Serum testosterone reduction and metabolism in aging male rats: correlation and mechanism].

OBJECTIVE: To investigate the mechanism of serum testosterone reduction, its relationship with metabolism, changes in the number and morphology of Leydig cells and endocrine function in aging male rats. METHODS: The levels of serum total testosterone (tT), LH, FSH, HDL, LDL, TG, TC, Glu, INS, IRG and LP were determined in young (9 mo) and aging rats (12, 15, 18 and 21 mo), with 6 in each group. The morphological changes of Leydig cells were observed under the microscope. The concentrations of testosterone secreted from the cultured Leydig cells with the stimulation of hCG and Forskolin were assayed. The apoptosis rates of Leydig cells were detected by TUNEL. The visceral fat was isolated and weighed, and the Lee's index calculated. All the above indexes were recorded and compared among different age groups. RESULTS: The aging rats showed a significant decrease in the levels of serum tT and TSI ([1.26 +/- 0.65] ng/ml and [0.07 +/- 0.65] ng/mIU) as compared with the young rats ([3.24 +/- 0.38] ng/ml and [0.21 +/- 0.01] ng/mIU) (P < 0.01). Obvious differences were found in the morphology of Leydig cells among different age groups. The T secretion of Leydig cells at 24, 48 and 72 h in aging rats was markedly decreased (P < 0.05) while their TUNEL positive rate remarkably increased in the aging rats (17.36% +/- 1.31%) compared with the young ones (7.02% +/- 1.05%) (P < 0.05). There were statistically significant differences between the young and aging rats in all the biochemical parameters including IRG, HDL, LDL, TG, TC and visceral fat content (P < 0.05), except the levels of serum Glu, INS and LP (P > 0.05). CONCLUSION: The serum T level and secreting capacity of Leydig cells are significantly lower in aging rats than in young ones, and the metabolic parameters undergo regular changes with the decreasing level of serum T. The reduction of testosterone in aging male rats may be associated with the decreased secreting capacity and number of Leydig cells and declined function of the pituitary.

[Semen analysis training and its evaluation].

OBJECTIVE: To establish the methods for training green-hand laboratorians in standard semen analysis and evaluating the training results, and afford some reference for internal quality control and training in andrology laboratories in China. METHODS: We trained the green-hand technicians in standard semen analysis recommended by WHO Laboratory Manual for the Examination and Processing of Human Semen (5th ed), and evaluated the training results by assessing the trainees' performance in the examination of sperm concentration and motility by statistic analysis. RESULTS: After training, the coefficients of variation of the semen samples with high, middle and low sperm concentration achieved by the trainees were 7.72% and 3.38% and 4.49%, and those with high, middle and high motility were 7.82%, 8.09% and 6.62%, respectively. We used Bland-Altman's method to evaluate the consistency between the results obtained by the trainees and those by the trainers. For sperm concentration, 4.77% of the datum points were out of the 95% consistency interval, and the absolute value of the biggest difference between the trainees and trainers was 8 x 10(6)/ml within the 95% consistency interval. For sperm motility, 7.15% of the data points were out of the 95% consistency interval, and the absolute value of the biggest difference between the trainees and trainers was 10% within the 95% consistency interval. Two-way analysis of variance showed no significant differences in the results of sperm concentration and motility analyses between the trainees and trainers (P > 0.05). CONCLUSION: Training in standard semen analysis significantly improved the precision of semen analysis among the green-hand laboratorians. The training and assessment methods we established proved to be effective and feasible.

[Effects of abnormal structure of sperm chromatin on the outcome of in vitro fertilization and embryo transfer].

OBJECTIVE: To explore the effects of sperm chromatin structure abnormalities on the outcome of in vitro fertilization and embryo transfer (IVF-ET). METHODS: Sperm DNA fragmentation and chromatin packaging defects were assessed in 136 couples undergoing IVF-ET because of infertility. The relationship between sperm DNA fragmentation, chromatin packaging defects and fertilization rate and clinical pregnancy was evaluated. RESULTS: Both sperm DNA fragmentation and chromatin packaging defect had a negative correlation with fertilization rate (r=-0.198, P<0.05, and r=-0.389, P<0.01, respectively). Both parameters were higher in couples who failed to achieve pregnancy than those who achieved clinical pregnancy (10.74% vs. 5.40%, P<0.01 and 23.58% vs. 11.83%, P<0.01, respectively). CONCLUSION: Abnormality of sperm chromatin structure is one of the reasons for IVF-ET failure. Examination of sperm chromatin structure is helpful in predicting the risk of IVF-ET failure and optimizing treatment of infertility.

[Clinical validation of screening scales for late onset of hypogonadism in Chinese males].

OBJECTIVE: To investigate the incidence of late onset of hypogonadism (LOH) in males as well as the sensitivity, specificity and applicability of the androgen deficiency in aging males (ADAM) questionnaire and the aging males' symptoms (AMS) scale in Chinese males based on the community population data. METHODS: A total of 1 498 old and middle-aged healthy males attended the ADAM and AMS investigations, of whom 434 received the measurement of the concentration of serum reproductive hormones, the positive rate of LOH screening, the rate of androgen deficiency, the clinical incidence of LOH, and the sensitivity and specificity of ADAM and AMS by tT and fT cut-off. The symptom evaluation cut-off value of the AMS score was optimized using the ROC curve. RESULTS: Although 5 of the subjects had previously received irregular testosterone supplement, none of them was given or actively sought for androgen therapy at the time of the investigation. Among the 40 - 69 years old males, the mean positive rates of LOH screening by ADAM and AMS were 80.77% and 32.34%, and the mean androgen deficiency rates obtained by tT and fT cut-off were 14.02% and 43.69%. The mean clinical incidences of LOH in the ADMA- and AMS-positive subjects were 37.85% and 15.42%. According to the fT cut-off, the sensitivities of ADAM and AMS were 86.63% and 35.29%, and their specificities were 24.48% and 63.49%, respectively. The symptom evaluation cut-off value of the AMS score optimized by the ROC curve was 19.5. CONCLUSION: The sensitivity and specificity of ADAM and AMS in the Chinese population are basically consistent with the results of most studies abroad, while the positive rate of LOH screening, the rate of androgen deficiency and the clinical incidence of LOH obviously higher in the former than those reported in other studies. Both ADAM and AMS are applicable to the Chinese population. The former is advantageous for its high sensitivity, time saving and easy operation, and therefore suitable for screening LOH, while the latter can be used for monitoring therapeutic efficacy.

DNA damage and oxidative stress in human liver cell L-02 caused by surface water extracts during drinking water treatment in a waterworks in China.

Because of the daily and life-long exposure to disinfection by-products formed during drinking water treatment, potential adverse human health risk of drinking water disinfection is of great concern. Toxicological studies have shown that drinking water treatment increases the genotoxicity of surface water. Drinking water treatment is comprised of different potabilization steps, which greatly influence the levels of genotoxic products in the surface water and thus may alter the toxicity and genotoxicity of surface water. The aim of the present study was to understand the influence of specific steps on toxicity and genotoxicity during the treatment of surface water in a water treatment plant using liquid chlorine as the disinfectant in China. An integrated approach of the comet and oxidative stress assays was used in the study, and the results showed that both the prechlorination and postchlorination steps increased DNA damage and oxidative stress caused by water extracts in human derived L-02 cells while the tube settling and filtration steps had the opposite effect. This research also highlighted the usefulness of an integrated approach of the comet and oxidative stress assays in evaluating the genotoxicity of surface water during drinking water treatment.

[Changes of serum reproductive hormones with aging among healthy males in a community population of Hebei Province].

OBJECTIVE: To investigate the changes of serum reproductive hormones with male aging and to compare the differences in the hormone levels among different age groups or between township and rural males of the same age group. METHODS: Using cluster and stratified sampling, we recruited 434 healthy old and middle-aged (40-69 years) males, 198 from the township and 236 from the rural communities. We determined the concentrations of serum total testosterone (tT), luteinizing hormone (LH) and sex hormone binding globulin (SHBG), free testosterone (fT), bio-available testosterone (Bio-T), and obtained the testosterone secretion index (TSI) and free testosterone index (fTI). Meanwhile, we included fifty-nine 20-39 years old males from the same communities in a control group. RESULTS: With the increase of age, the serum tT levels did not change significantly, while the levels of serum LH and SHBG increased, and those of fT, Bio-T, TSI and fTI decreased gradually. Statistically significant differences were found among the four different age groups in all the parameters of reproductive hormones (P < 0.01), except in the serum tT level (P > 0.05). The serum tT level was not significantly correlated with aging and LH (P > 0.05). Serum LH and SHBG had a marked positive correlation with aging, and SHBG with LH (P < 0.01), while fT, Bio-T, TSI and fTI were negatively correlated with aging and the LH level (P < 0.01). Serum LH, TSI and fTI showed statistical differences (P < 0.05), while fT and Bio-T exhibited extremely significant differences (P < 0.01) between the township and rural males in the 40 -49 yr group, and in the same age group, the increase rates of serum LH and SHBG and reduction rates of fT, Bio-T, TSI and fTI were higher in the rural men than in the township residents. However, the results were just the opposite in the 50 - 59 and 60 - 69 yr groups. CONCLUSION: The levels of serum LH, SHBG, fT, Bio-T, TSI and fTI changed with aging in a gradientmanner in the old and middle-aged males, but no significant changes were observed in the level of serum tT. There were statistical differences in many parameters of serum reproductive hormones among different age groups or between township and rural males.

[Changes of semen parameters in Chinese fertile men in the past 25 years].

OBJECTIVE: To analyze the changes of seminal parameters in Chinese fertile men during the past 25 years. METHODS: We collected semen samples from 5,834 fertile men in 14 different provinces (including Beijing) between 1980 and 2005 and retrospectively studied their seminal parameters, abstinence durations and total testis volumes by meta-analysis. RESULTS: Compared with the first 15 years, a significant decrease was observed in both sperm density and total number of sperm per ejaculate in the semen samples collected between 1996-2000 (P < 0.0001 and P < 0.05), but not obvious in those between 1996-2000 and after 2005 (P > 0.05). As for sperm motility, no time-related changes were noted (P > 0.05) except a reduction with the increase of age. CONCLUSION: There was a decline in sperm density and total number of sperm per ejaculate in Chinese fertile men over the past 25 years, although not significant in the latter 10 years since 1996, but with no time-related changes in sperm motility.

[Effect of (CAG) n polymorphism of androgen receptor gene on hormonal male contraception].

OBJECTIVE: To study (CAG) n polymorphism of the androgen receptor (AR) gene in responders and non-responders of male volunteers who received testosterone undecanoate intramuscular injection for contraception and to explore the effect of the polymorphism on hormonal male contraception. METHODS: Twenty-nine non-responders and 34 responders were enrolled in this study as a test and a control group respectively. The numbers of CAG sequence repeats were determined by PCR and DNA sequencing, and the effect of (CAG) n polymorphism on hormonal male contraception was analyzed. RESULTS: The means of CAG repeats of the test and the control group were 23.62 and 22.97, with no significant difference in between (P > 0.05). The short CAG repeats (n < or = 22) constituted 51.7% in the test group and 50% in the control, while the long ones (n > 22) accounted for 48.3% and 50% , respectively. The short and the long group had a similar distribution. No association was found between CAG repeats and sperm concentration. With FSH > 0.2 IU/L, the probability of azoospermia in the long CAG repeat group was 1.5 times that of the short one. CONCLUSION: CAG repeats in the AR gene presented polymorphism in the subjects, with no significant difference between the responders and non-responders. Further investigation has yet to be performed into the relationship of hormonal male contraception with CAG repeats or other factors.

Elevated levels of urinary 8-hydroxy-2 -deoxyguanosine, lymphocytic micronuclei, and serum glutathione S-transferase in workers exposed to coke oven emissions.

To investigate associations among occupational exposure to coke oven emissions (COEs), oxidative stress, cytogenotoxic effects, change in the metabolizing enzyme glutathione S-transferase (GST), and internal levels of polycyclic aromatic hydrocarbons (PAHs) in coke oven workers, we recruited 47 male coke oven workers and 31 male control subjects from a coke oven plant in northern China. We measured the levels of 1-hydroxypyrene (1-OHP) and 8-hydroxy-2 -deoxyguanosine (8-OHdG) in urine, micronucleated binucleated cells (BNMNs) in peripheral blood lymphocyte, and GST in serum. Our results showed that the group exposed to COEs had significantly increased levels of 1-OHP [median 5.7; interquartile range (IQR), 1.4-12.0 micromol/mol creatinine] compared with the control group (3; 0.5-6.4 micromol/mol creatinine). In addition, the median levels (IQR) of 8-OHdG, BNMNs, and GST were markedly increased in the exposed [1.9 (1.4-15.4) micromol/mol creatinine; 6 (2-8) per thousand ; 22.1 (14.9-31.2) U/L, respectively] compared with controls [1.3 (1.0-4.0) micromol/mol creatinine, 2 (0-4) per thousand; and 13.1 (9.5-16.7) U/L, respectively]. These results appeared to be modified by smoking. However, multivariate logistic regression analysis revealed that exposure to COEs had the highest odds ratio among variables analyzed and that smoking was not a significant confounder of the levels of studied biomarkers. Overall, the present findings suggest that COE exposure led to increased internal PAH burden, genetic damage, oxidative stress, and GST activity. The consequences of the changes in these biomarkers, such as risk of cancer, warrant further investigations.