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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 0.05). Results Nutritional obesity can damage spermatogenesis in male rats due to long-term effects on spermatogenesis.

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.

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.

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.

Cyclooxygenase-2 (cox-2) overexpression has been observed in several types of human cancers and has been implicated in carcinogenesis. To elucidate the role of cox-2 in esophageal carcinogenesis, we evaluated the expression of cox-2 in normal squamous epithelium squamous epithelial dysplasia (n=47), and squamous cell carcinoma of the esophagus (n=86) by immunohistochemistry, reverse transcription-PCR assay, and western blotting. A significant overexpression of cox-2 was observed in esophageal squamous dysplasia and squamous cell carcinoma compared with normal squamous epithelium. The immunoreactive score of cox-2 expression, an index determined by intensity and positivity of cox-2 staining, was 0.71 +/- 0.46 (mean +/- SD) in normal squamous esophagus, 2.19 +/- 1.79 in squamous epithelial dysplasia, and 2.67 +/- 1.77 in squamous cell carcinoma. The results of immunohistochemistry were confirmed by a reverse transcription-PCR assay and western blotting analysis. Cox-2 expression level was correlated with proliferation activity assessed by proliferating cell nuclear antigen (PCNA) index and MIB-1 index in dysplastic lesion (r=0.55, P0.01 with PCNA and r=0.72, P0.01 with MIB-1) and carcinoma (r=0.56, P0.01 with PCNA and r=0.72, P0.01 with MIB-1). Elevated cox-2 expression was associated with high p53 expression (p0.001) but not with clinicopathological features including age, sex, tumor size, histological grade, lymph node metastasis, and TNM stage. The results indicated that cox-2 may be involved in an early stage of squamous carcinogenesis of the esophagus, and that cox-2 overexpression was related to cell proliferation in esophageal squamous dysplasia and squamous cell carcinoma.

Background: The purpose of the present paper was to study the expression of cyclooxygenase-2 (COX-2) in normal squamous epithelium, squamous dysplasia and squamous cell carcinoma (SCC) of the esophagus, to elucidate the role of COX-2 in esophageal carcinogenesis, and to evaluate the in vitro effect and mechanism of a COX-2 inhibitor, NS-398, in inducing growth inhibition and apoptosis of human esophageal cancer cells. Methods: Biopsy specimens of esophageal dysplasia (n = 21), and surgical resections of SCC (n = 37) were compared with normal esophagus (n = 37) and analyzed by RT-PCR. Human esophageal cells were used for the study. Anti-proliferative effect was measured by MTT, apoptosis was determined by DNA fragmentation assay. Results: Marked COX-2 expression was shown in SCC and esophageal squamous dysplasia, and no marked COX-2 expression was observed in the normal squamous epithelium, respectively. NS-398 could inhibit esophageal cells growth in a dose-dependent manner, induce apoptosis, and elevate caspase-3 activity in vitro. Conclusions: This study provides evidence that COX-2 is upregulated in the majority of cases of squamous dysplasia and SCC of esophagus, and that NS-398 can inhibit growth and induce apoptosis via activating caspase-3 activity in vitro. These results suggest that selective inhibitors of COX-2 may be an effective preventive and therapeutic option for esophageal carcinoma.

To investigate the effect of X-ray repair cross complementing 1 (XRCC1) genetic polymorphisms on esophageal cancer risk, we determined XRCC1 polymorphisms at codon 194 (Arg→Trp) and codon 399 (Arg→Gln) in 135 patients with esophageal squamous cell carcinoma (ESCC) and 152 normal controls from hospitals. Although polymorphism at codon 194 was not associated with risk for ESCC, we found that the frequency of XRCC1 399 Gln/Gln genotype in ESCC patients (14.1%) was significantly higher than that in normal controls (3.3%), and that XRCC1 399 Gln/Gln genotype was associated with an increased risk of ESCC (odds ratio (OR)=5.15, 95% confidence interval (CI): 2.42–0.93). In addition, we found that the risk for smoker increased 4.2-fold than non-smokers in the 399 Gln/Gln genotype (OR=4.20, 95% CI: 2.37–7.44). These results suggest that XRCC1 399 Gln/Gln genotype may contribute to the risk of ESCC and modify risk associated with smoking.

Dear Editor, We are very glad to see that the Asian Journal of Andrology published a Special Issue on Semen Analysis in 21st Century Medicine, which well revealed some behind-the-scene controversies of the 5th edition of the WHO laboratory manual for the examination and processing of human semen 1. Three articles from the special issue, two on the reference values of semen parameters 2, 3 and another presenting the investigation results of 118 laboratories performing semen analysis in Mainland China 4, are very thought-provoking and we would like to share some of our views on these topics. First, we noticed that the lower limit of the reference values of semen parameters in the 5th edition of the manual is reduced. Can this reduction reflect a genuine decline in semen quality? We are doubtful on this point. The reasons for the reduction vary from the variations in population selection, and the biases in methodologies of measurement and data processing to the recommended application of 'stricter criteria'. It has been a long time since the change in semen quality of healthy men become a controversial issue throughout the world. There is no definite conclusion on the trend of overall semen quality, owing to the differences in study design, definition of normal men, specimen collection methods, methods used for measurement of sperm and for statistical analysis, selection biases, measurement errors, regional differences, and other factors such as age, years spent in semen collection, the period of abstinence, etc. In addition, researches on change of semen quality are only retrospective analyses. Various insurmountable biases and confounding factors also make the conclusion poorly reliable. Although careful efforts were made to reduce the biases in some studies, discrepancies in results still remained. With the publication of the 5th edition of the WHO manual, more concerns and debates would be aroused. So far, it is not yet known whether the reduced lower limit of the reference values can indicate the decline in semen quality, but strictly evidence-based study design, standardization of measurement criteria and quality control (QC) of semen analysis would explain the reduction in the lower limit. Second, we think it is necessary to establish the reference intervals for values of semen parameters based on a fertile population using the time-to-pregnancy method in China. Semen quality is commonly taken as a surrogate indicator of male fertility, reproductive toxicology, epidemiology and pregnancy risk assessments. Reference intervals for values of semen parameters from a fertile population and the standardization of procedures for the examination of human semen given in the 5th edition of the manual provide a realistic basis for medical professionals all over the world, especially in China, where more than one-fifth of the world population inhabits. China is in urgent need of reference values of semen parameters derived from fertile Chinese men, which calls for a prospective, multi-center and nation-wide population-based study. Such a large-scale study will provide evidence for the prognosis of fertility, diagnosis of infertility and impact of environmental factors on human existence. It will also be helpful for the State Food and Drug Administration of China to establish medical guidelines for male fertility regulation. Third, internal and external QC of semen analysis need to be further improved. Semen analysis is used widely and has a significant role in the assessment of male fertility. There have been reports on the absence of standardization on semen analysis 5, 6, 7, 8 and obvious differences among laboratories 9, 10, 11, and some researchers have called for a comprehensive QC 12, 13, 14, 15, 16. The lack of consistency and standardization 17 incurs difficulties for clinicians to interpret or compare the results of semen analysis from different laboratories. Therefore, improvements in the following aspects would help improve the quality of semen analysis and ensuring the reliability of the results: using accredited and standard measurement, implementing internal QC and external QC. Finally, the criterion for determining an eligible donor in China should be revised accordingly to elevate the present poor eligibility after comprehensive investigations. The current quality requirements for an eligible donor's semen as per the Essential Criterion and Technical Specification of the Human Sperm Bank, issued by the Ministry of Health of China, are based on the 4th edition manual. With the reduction in certain semen parameters such as semen concentration, motility and semen volume in the 5th edition, we believe that studies on the reference intervals for values of semen parameters from fertile men must be carried out before any modification of the criteria is made in China. Such expanded studies would lead experts to conduct extensive discussions and would thus provide informative suggestions for policy makers before making any modification in the criteria of the human sperm bank in China.