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Objective: To analyse the relationship between male infertility and chromosomal translocations, and the influence of different types of chromosomal translocations on semen quality, testicular volume and hormone levels. Methods: A retrospective cohort of infertile men was recruited for chromosomal analysis using standard Giemsa stain banding. Physical examinations, semen analysis, hormonal analysis and the detection of azoospermia factor (AZF) microdeletions were carried out. Men with normal fertility were used as controls. Results: Among the 1056 infertile men, 22 had chromosomal translocations (2.1%), including seven with Robertsonian translocations (0.7%), 11 with autosome- autosome reciprocal translocations (1.0%) and four with gonosome-autosome reciprocal translocations (0.4%). Left and right testicular volumes of patients with chromosomal translocations were significantly smaller than those in the fertile control group. There were no significant differences in hormone levels between patients with chromosomal translocations and fertile controls, except for significantly lower testosterone levels in patients with Robertsonian and gonosome- autosome reciprocal translocations compared with the controls. All AZF microdeletion analyses showed normal results. Conclusions: Chromosomal translocations may cause reductions in testicular volume and testosterone level, which may impact spermatogenesis, resulting in azoospermia or oligozoospermia and male infertility.

OBJECTIVE: To determine characteristics of classical and partial deletions of the Y chromosome azoospermia factor (AZF) region transmitted from father to son by natural fertilization. METHODS: Patients from northeastern China with primary male infertility ( n = 10) and their fathers were investigated. Healthy fertile men and women were recruited as positive and negative controls, respectively. The Y chromosome microdeletions were detected by polymerase chain reaction. Serum concentrations of reproductive hormones were determined by electrochemiluminescence immunoassay and enzyme-linked immunosorbent assay. RESULTS: Expansions of microdeletions were observed in seven father-son pairs; de novo microdeletions were found in the remaining three father-son pairs. The Y chromosome microdeletions were larger in sons than in their fathers. Patients with infertility had significantly higher levels of follicle stimulating hormone and lower levels of inhibin B than fertile men. CONCLUSIONS: The Y chromosome micro deletions were transmitted from father to son via natural transmission. These microdeletions may expand during transmission or arise de novo, possibly resulting in reduced fertility.

This study investigated the effects of Ureaplasma urealyticum infection and raised seminal leucocyte levels on sperm morphology in 967 infertile males and 201 fertile healthy volunteers. U. urealyticum infection led to a significant decrease in the percentage of morphologically normal sperm in infertile males. There was a clear correlation between U. urealyticum infection, raised seminal leucocytes and abnormal sperm morphology. The percentage of morphologically normal sperm was significantly lower in U. urealyticum-positive than U. urealyticum-negative infertile males or fertile controls. The percentage of morphologically normal sperm was lowest in U. urealyticum-positive males with raised seminal leucocytes. Previous studies have found raised seminal leucocyte levels to be associated with reactive oxygen species. The authors suggest that oxidative stress contributes to the effects of U. urealyticum on sperm morphology. In conclusion, U. urealyticum infection can negatively affect sperm morphology and this study provided two possible mechanistic explanations.

The aim of this study was to investigate the effect of cigarette smoking on seminal plasma zinc levels and sperm parameters, and to examine the role of seminal plasma zinc. Semen samples from 79 non-smokers and 68 smokers were obtained. There was a significant decrease in seminal plasma zinc in smokers and a clear correlation between seminal plasma zinc levels and the extent of smoking. Sperm parameters (concentration, motility and morphology) among smokers were significantly lower in comparison to non-smokers. These parameters were also significantly decreased among smokers with abnormal zinc levels, while there was no significant difference between non-smokers with normal zinc and non-smokers with abnormal zinc levels. As previous studies have shown that seminal plasma zinc is associated with a decrease of anti-oxidant defences, seminal plasma zinc could be a contributor to the effects of cigarette smoking on sperm parameters. In conclusion, cigarette smoking can affect sperm parameters and this study may help towards providing a mechanistic explanation.