Diffusion-weighted MR imaging of normal and abnorma scrotum： preliminary results

Magnetic resonance （MR） imaging of the scrotum represents an important supplemental diagnostic tool in the evaluation of scrotal diseases. Diffusion-weighted （DW） MR imaging is a developing technique, proved to improve tissue characterization. We evaluated the feasibility and diagnostic performance of DW MR imaging in the detection and characterization of scrotal lesions. We retrospectively evaluated 31 scrotal lesions （23 intratesticular and 8 extratesticular） in 26 men. All MR examinations were performed on a 1.5-T unit, using a pelvic-phased array coil. DW sequences were obtained using a single shot, multislice spin echo planar diffusion pulse sequence and a b factor of 0 and 900 s mm-2. The DW MR characteristics and the apparent diffusion coefficient （ADC） values of normal scrotal contents and scrotal diseases were evaluated. Comparison between the ADC values of normal scrotum, benign lesions and scrotal malignancies was performed. The accuracy of conventional sequences, DW images alone and DW imaging combined with conventional images in differentiating benign from malignant scmtal lesions was calculated. The ADC values of testicular malignancies were different from those of normal testis and benign intratesticular lesions, and the ADC values of benign extratesticular lesions from those of normal epididymis （P〈0.05）. The overall accuracy of conventional imaging, DW imaging alone and DW MR combined with conventional sequences in the characterization of intratesticular lesions was 91%, 87% and 100%, respectively. Our findings suggest that DW MR imaging and ADC values may provide valuable information in the diagnosis and characterization of scrotal diseases.

Genetic and epigenetic risks of intracytoplasmic sperm injection method

Pregnancies achieved by assisted reproduction technologies, particularly by intracytoplasmic sperm injection （ICSI） procedures, are susceptible to genetic risks inherent to the male population treated with ICSI and additional risks inherent to this innovative procedure. The documented, as well as the theoretical, risks are discussed in the present review study. These risks mainly represent thatconsequences of the genetic abnormalities underlying male subfertility （or infertility） and might become stimulators for the development of novel approaches and applications in the treatment of infertility. In addition, risks with a polygenic background appearing at birth as congenital anomalies and other theoretical or stochastic risks are discussed. Recent data suggest that assisted reproductive technology might also affect epigenetic characteristics of the male gamete, the female gamete, or might have an impact on early embryogenesis. It might be also associated with an increased risk for genomic imprinting abnormalities.

Apparent diffusion coefficient values of normal testis and variations with age

The usefulness of diffusion-weighted magnetic resonance imaging （DWI） in the evaluation of scrotal pathology has recently been reported. A standard reference of normal testicular apparent diffusion coefficient （ADC） values and their variations with age is necessary when interpreting normal testicular anatomy and pathology. We evaluated 147 normal testes using DWI, including 71 testes from 53 men aged 20-39years （group 1）, 67 testes from 42 men aged 40-69 years （group 2） and nine testes from six men older than 70years （group 3）. DWI was performed along the axial plane, using a single shot, multislice spin-echo planar diffusion pulse sequence and b-values of 0 and 900 s mm-2. The mean and standard deviation of the ADC values of normal testicular parenchyma were calculated for each age group separately. Analysis of variance （ANOVA） followed by post hoc analysis （Dunnett T3） was used for statistical purposes. The ADC values （x 10-3 mm2s-1） of normal testicular tissue were different among age groups （group 1：1.08 ± 0.13; group 2：1.15 ±0.15 and group 3：1.31± 0.22）. ANOVA revealed differences in mean ADC among age groups （F= 11.391, P〈 0.001）. Post hoc analysis showed differences between groups 1 and 2 （P= 0.008） and between groups 1 and 3 （P= 0.043）, but not between groups 2 and 3 （P= 0.197）. Our findings suggest that ADC values of normal testicular tissue increase with advancing age.

Potential role of imaging in assessing harmful effects on spermatogenesis in adult testes with varicocele

Varicocele is characterized by an abnormal dilatation and retrograde blood flow in the spermatic veins. Varicocele is the leading correctable cause of male infertility. Although it is highly prevalent in infertile men, it is also observed in individuals with normal fertility. Determining which men are negatively affected by varicocele would enable clinicians to better select those men who will benefit from treatment. To assess the functional status of the testes in men with varicocele, color Doppler sonographic parameters were evaluated. Testicular arterial blood flow was significantly reduced in men with varicocele, reflecting an impairment of spermatogenesis. An improvement in the testicular blood supply was found after varicocelectomy on spectral Doppler analysis. Testicular contrast harmonic imaging and elastography might improve our knowledge about the influence of varicocele on intratesticular microcirculation and tissue stiffness, respectively, providing possible information on the early damage of testicular structure by varicocele. Magnetic resonance imaging(MRI), with measurement of apparent diffusion coefficient has been used to assess the degree of testicular dysfunction and to evaluate the effectiveness of varicocele repair. Large prospective studies are needed to validate the possible role of functional sonography and MRI in the assessment of early defects of spermatogenesis in testes with varicocele.

Phosphatidylethanolamine N-methyltransferase and choline dehydrogenase gene polymorphisms are associated with human sperm concentration

Choline is a crucial factor in the regulation of sperm membrane structure and fluidity, and this nutrient plays an important role in the maturation and fertilizing capacity of spermatozoa. Transcripts of phosphatidylethanolamine N-methyltransferase （PEMT） and choline dehydrogenase （CHDH）, two basic enzymes of choline metabolism, have been observed in the human testis, demonstrating their gene expression in this tissue. In the present study, we explored the contribution of the PEMTand CHDHgene variants to sperm parameters. Two hundred oligospermic and 250 normozoospermic men were recruited. DNA was extracted from the spermatozoa, and the PEMT -774G〉C and CHDH ＋432G〉T polymorphisms were genotyped. The genotype distribution of the PEMT-774G〉C polymorphism did not differ between oligospermic and normozoospermic men. In contrast, in the case of the CHDH ＋432G〉T polymorphism, oligospermic men presented the CHDH432GIG genotype more frequently than normozoospermic men （62% vs. 42%, P〈0.001）. The PEMT774GIG genotype was associated with a higher sperm concentration compared to the PEMT774GIC and 774C/C genotypes in oligospermic men （12.5±5.6× 10^6 spermatozoa m1-1 vs. 8.3±5.2×10^6 spermatozoa m1-1, P〈0.002） and normozoospermic men （81.5±55.6×10^6 vs. 68.1±44.5×10^6 spermatozoa m1-1, P〈0.006）. In addition, the CHDH432G/G genotype was associated with higher sperm concentration compared to CHDH432G.T and 432T/T genotypes in oligospermic （11.8±5.1×10^6 vs. 7.8±5.3×10^6 spermatozoa m1-1, P〈0.003） and normozoospermic men （98.6±62.2×10^6 vs. 58.8±＋33.6×10^6 spermatozoa m1-1, P〉0.001）. In our series, the PEMT-774G〈C and CHDH ＋432G〈T polymorphisms were associated with sperm concentration. This finding suggests a possible influence of these genes on sperm quality.

Evidence of increased chromosomal instability in infertile males after exposure to mitomycin C and caffeine

Aim： To evaluate the genetic instability of 11 fertile and 25 infertile men. Methods： The methodology of sister chromatid exchanges （SCEs） was applied to cultures of peripheral blood lymphocytes, and the levels of SCEss were analyzed as a quantitative index of genotoxicity, along with the values of the mitotic index （MI） and the proliferation rate index （PRI） as qualitative indices of cytotoxicity and cytostaticity, respectively. The genotoxic and antineoplastic agent, mitomycin C （MMC）, and caffeine （CAF） - both well-known inhibitors of DNA repair mechanism - were used in an attempt to induce chromosomal instability in infertile men, so as to more easily detect the probable underlying damage on DNA. Results： Our experiments illustrated that infertile men, compared with fertile ones, demonstrated a statistically significant DNA instability in peripheral blood lymphocytes after being exposed simultaneously to MMC and CAF. Conclusion： The current study showed vividly that there was genetic instability in infertile men which probably contributes to the development of an impaired reproductive capacity. （Asian JAndro12006 Mar; 8： 199-204）

mpact of antioxidants on seminal vesicles function ind fertilizing potential in diabetic rats

Diabetes mellitus significantly affects the male reproduction and sexual function. In the present study, we investigated the diabetes-induced dysfunction of seminal vesicles （SVs） in the diabetes-rat model and the role of antioxidants. Streptozotocin-induced diabetes after 4 weeks caused smaller size of the organs, hypercontractility, histological abnormalities, increased concentrations of malondialdehyde in the serum and tissue, overexpression of oxidative stress markers, and cleaved caspase-3 as identified by immunohistochemistry in the SVs. In addition, diabetes resulted in deceased levels of serum testosterone and no newborns after the mating studies. Antioxidants significantly normalized all the above parameters, except for the severely decreased serum testosterone levels and the negative outcome of the mating studies. The present study gives evidence for the important role of diabetes-induced oxidative stress in the function and structure of these androgen-dependent organs. Antioxidants may be a promising supplementary therapy for diabetic male patients to alleviate ejaculatory disorders but alone is not efficient treatment for the mitigation of infertility.