The protective effect of vitamin E against oxidative damage caused by formaldehyde in the testes of adult rats

Aim： To investigate the effect of formaldehyde （FA） on testes and the protective effect of vitamin E （VE） against oxidative damage by FA in the testes of adult rats. Methods： Thirty rats were randomly divided into three groups： （1） control; （2） FA treatment group （FAt）; and （3） FAt ＋ VE group. FAt and FAt ＋ VE groups were exposed to FA by inhalation at a concentration of 10 mg/m^3 for 2 weeks. In addition, FAt ＋ VE group were orally administered VE during the 2-week FA treatment. After the treatment, the histopathological and biochemical changes in testes, as well as the quantity and quality of sperm, were observed. Results： The testicular weight, the quantity and quality of sperm, the activities of superoxide dismutase （SOD）, glutathione peroxidase （GSH-Px） and glutathione （GSH） were significantly decreased whereas the level of malondialdehyde （MDA） was significantly increased in testes of rats in FAt group compared with those in the control group. VE treatment restored these parameters in FAt ＋ VE group. In addition, microscopy with hematoxylin-eosin （HE） staining showed that seminiferous tubules atrophied, seminiferous epithelial cells disintegrated and shed in rats in FAt group and VE treatment significantly improved the testicular structure in FAt ＋ VE group. Conclusion： FA destroys the testicular structure and function in adult rats by inducing oxidative stress, and this damage could be partially reversed by VE.

Effects of simulated microgravity on antioxidant system in testis of adult rats

Objective： To study the effects of simulated microgravity induced by tail-suspension on histological structures and antioxidant system in testis of adult rats. Methods： Forty Spraque-Dawley adult male rats were randomly divided into four groups, two experimental groups and two synchronic control groups. Rats in the two experimental groups were tail-suspended for 14 d and 28 d respectively, then serum hormone, testicular morphology and biochemical changes were evaluated. Results： Compared with the synchronic controls, serum testosterone （T） levels and testicular superoxide dismutase （SOD） significantly decreased（P 〈 0.05）, while testicular malondialdehyde（MDA） significantly increased （P 〈 0.05） in tail-suspended rats. The changes were more prominent in the 28 d tail-suspended rats. In addition, hematoxylin and eosin （HE） staining showed that seminiferous tubules atrophied, spermatogenic cells decreased, and seminiferous epithelial cells disintegrated and shed, abnormal multinucleated giant cells appeared and the lumina were azoospermic in tail-suspended rats. ConcIusion： Simulated microgravity induced by tailsuspension has a harmful effect on male reproduction of adult rats by decreasing the ability of testicular antioxidant defense.

The expression of Usp26 gene in mouse testis and brain

Deubiquitinating enzymes （DUBs） play an important role in ubiquitin-dependent processes as negative regulators of protein ubiquitination. Ubiquitin-specific protease 26 （USP26） is a member of this family. The expression of Usp26 in mammalian testis and in other tissues has yet to be fully elucidated. To study the expression of Usp26 mRNA and protein in various murine tissues, reverse transcription （RT）-PCR and immunohistochemistry analyses were carried out. The RT-PCR analysis showed that the Usp26 transcript was expressed in all of the tested tissues. USP26 protein localization was examined by immunohistochemistry, and it was shown that USP26 was not detectable at 20 days postpartum, with the expression restricted to the cytoplasm of condensing spermatids （steps 9-16）, Leydig cells and nerve fibers in the brain. In addition, the USP26 protein was detected at moderate levels in myocardial ceils, the corpus of epidydimis, epithelium of the renal tubules and the seminal gland of postnatal day 35 mice. Its spatial and temporal expression pattern suggests that Usp26 may play an important role in development or function of the testis and brain. Further research into these possibilities is in progress.

EFFECT OF SIMULATED WEIGHTLESSNESS ON REPRODUCTION OF ADULT MALE RATS

Objective To study the effects of simulated weightlessness induced by tail-suspension on reproduction in adult male rats and its mechanisms. Methods Twenty Spraque-Dawley adult male rats were randomly divided into two groups: the experimental group and control group. Rats in the experimental group were tail-suspended for 14 days. After the treatment, the weight and morphology of testis, the quantity and quality of sperm, the level of serum testosterone and the apoptosis rate of testicular cells were observed. Results Compared with the control, the testicular weight, the quantity and quality of sperm, the level of serum testosterone significantly decreased (P<0.05) while the apoptosis rate of testicular cells significantly increased (P<0.05) in tail-suspended rats. In addition, hematoxylin and eosin (HE) staining showed that seminiferous tubules atrophied, spermatogenic cells decreased, seminiferous epithelial cells disintegrated and shed, and the lumina were azoospermic. Conclusion Simulated weightlessness induced by tail-suspension has a harmful effect on male reproduction of adult rats by increasing the apoptosis of testicular cells.

Application of human growth hormone to patients with polycystic ovary syndrome during in vitro fertilization

Objective:To observe the effect of applying human growth hormone during in vitro fertilization to patients with polycystic ovary syndrome(PCOS) Methods:One hundred and twenty-one cycles of in vitro fertilization and embryo transfer in PCOS patients with anovulation from Dec.2008 to Nov.2010 were studied retrospectively.Of these 121 cycles,48 were with treatment of growth hormone(GH group),73 without GH treatment(control group).The dose of gonadotropin(Gn),the number of retrieved oocytes,good-quality embryo rate,implantation rate,frozen embryo rate,and pregnancy rate were compared. Results:The dosage of Gn was slightly higher in GH group than that in control group(29.18±8.33 vs.23.43±8.68 ampoullas,4U/ampoulla) and the number of retrieved oocytes in GH group were slightly less than that in control group(10.73±6.0 vs.14.0±8.57),but there were no significant differences(P>0.05).The good-quality embryo rate(59.1%vs.33.3%),frozen embryo rate(87.5%vs.58.9%),pregnancy rate(56.5%vs. 35.3%) and implantation rate(35.3%vs.20.4%) in GH group were all significantly higher than those in control group(P<0.05). Conclusion:Early usage of GH in the ovarian hyperstimulation in PCOS patients could significantly improve good-quality embryo rate,implantation rate and pregnancy rate.

Urodynamic Characteristics of Awake Rats under Retrained versusFreely Moving Condition：Using a Novel Model

Urodynamic investigation in conscious rats is widely employed to explore functional bladder disorders of various etiologies and pathogeneses. Rats can be placed in restraining cages or wide cabinets where they are allowed to move freely during cystometry. However, the requirements of special devices hampered the application of urodynamic test in freely moving rats, and whether the restraint has any effects on urodynamic parameters in conscious rats remains obscure. In the present study, we described a novel approach for urodynamic investigation in both restrained and freely moving conscious rats. In addition, we for the first time systematically compared the urodynamic parameters of rats in the two conditions. With the current method, we successfully recorded stable and repeatable intravesical pressure traces and collected expected reliable data, which supported the idea that the restraint does not affect the activity of the micturition reflex in rats, provided sufficient and appropriate measures could be applied during cystometry. Fewer technique problems were encountered during urodynamic examination in restrained rats than in freely moving ones. Taken together, conscious cystometry in rats placed in restraining cages with proper managements is a reliable and practical approach for evaluating the detrusor activity and bladder function.

Novel mutations in ubiquitin-specific protease 26 gene might cause spermatogenesis impairment and male infertility

Aim： To study the incidence of single nucleotide polymorphisms in ubiquitin-specific protease 26 （USP26） gene and its involvement in idiopathic male infertility in China. Methods： Routine semen analysis was performed. Infertility factors such as immunological, infectious and biochemical disorders were examined to select patients with idiopathic infertility. DNA was isolated from peripheral blood of the selected patients and control population, which were examined for mutations using polymerase chain reaction-single strand conformation polymorphism analysis. Furthermore, nucleotide sequences were sequenced in some patients and controls. Results： Of 41 infertile men, 9 （22.0%, P = 0.01） had changes in USP26 gene on the X chromosome. A compound mutation （364insACA; 460G→A） was detected in 8 patients （19.5%, P = 0.01） and a 1044T→A substitution was found in 1 patient （2.4%, P 〉 0.05）. All three variations led to changes in the coding amino acids. Two substitutions predict some changes： 460G→ A changes a valine into an isoleucine, and 1044T → A substitutes a leucine for a phenylalanine. Another insertion of three nucleotides ACA causes an insertion of threonine. No other changes were found in the remaining patients and fertile controls. Conclusion： The USP26 gene might be of importance in male reproduction. Mutations in this gene might be associated with male infertility, and might negatively affect testicular function. Further research on this issue is in progress.

Study on HBV Vertical Transmission via the in vitro Fertilization (IVF) Technique

Objective To study the hepatitis B virus （HBV） vertical transmission via infected spermatozoa. Methods Eighteen male patients with HBV infection who underwent in vitro fertilization （IVF） were studied, 5 HBV negative patients were selected as the control. Fluorescence in situ hybridization （FISH） analysis using the partial-length HBV DNA as the hybridization probe was performed to explore the existence of HBV DNA in the sperm and in the host embryonic genome. Results FISH showed that 5 of 18 patients＇ sperm presented positive signals and 2 of 18 embryos presented positive signals, while no positive signals were found in control group. Conclusion The HBV DNA was found in human sperm and embryos of HBV patients. These results provide direct evidence that HBV DNA could transmit to foetus via human infected spermatozoa.