A new technique for analysis of human sperm morphology in unstained cells from raw semen.

Sperm morphology analysis is a fundamental component of semen analysis, but its real significance has been clouded by the plethora of techniques used for its evaluation. Most involve different fixation and staining procedures that induce artefacts. Herein we describe Trumorph (Proiser R+D, Paterna, Spain), a new method for sperm morphology analysis based on examination of wet preparations of spermatozoa immobilised, after a short 60°C shock, in narrow chambers and examined by negative phase contrast microscopy. A range of morphological forms was observed, similar to those found using conventional fixed and stained preparations, but other forms were also found, distinguishable only by the optics used. The ease of preparation makes the Trumorph a robust method applicable for the analysis of living unmodified spermatozoa in a range of situations. Subsequent studies on well-characterised samples are required to describe the morphology of spermatozoa with fertilising potential.

Comparison of gene expression of the oncogenic Wnt/ß-catenin signaling pathway components in the mouse and human epididymis.

ß-catenin is an integral part of the Wnt signaling pathway and has been linked to tumorigenesis and multiple developmental processes. The high ß-catenin expression with low tumor incidence in the human epididymis is thus intriguing. In the present study, the ß-catenin gene and protein was found to be highly expressed in the murine caput epididymidis, and the protein mainly localized along the lateral plasma membranes of adjacent epithelial cells throughout both human and mouse epididymides. Furthermore, the adult mouse epididymis was found to express almost all the Wnt/ß-catenin signaling pathway genes that were determined previously by our group in the human organ. Despite the differences in epididymal structure, the similar location of ß-catenin and the high concordance of this pathway's components' gene expression in both the adult human and mouse epididymides make the mouse a suitable animal model for studying the anti-tumor mechanism of the epididymis. In addition, both the mRNA and protein expression of ß-catenin shared a similar spatial expression as the mRNA of Ros1, a proto-oncogene and a key developmental regulator of the initial segment of the mouse epididymis. The observations on the parallel temporal expression of ß-catenin and Ros1 during postnatal development raise the possibility that the canonical Wnt signaling pathway has an additional role in the postnatal development of mouse epididymis.

Epididymal research: more warp than weft?

From a review of some aspects of epididymal structure, function and research done largely in my research area over the last 50 years, I conclude that more is known than is understood of sperm maturation and storage in the epididymis. Highly qualified technicians have not always applied sophisticated modern techniques in well-considered experiments to physiologically relevant and properly-prepared samples, so that our understanding of the biological problem of the nature of the epididymal epithelial influence on maturing epididymal spermatozoa has not kept pace with the outpouring of data generated, much of which is difficult to interpret. We stand at a crossroads of where to aim our limited resources and personnel: should we continue new technology-led studies in many directions, backtrack to test hypotheses and fill in gaps in our knowledge, or consider more biological directions to our research?

Semen quality: variations among fathers and effects of moderate alcohol drinking.

Semen analysis results from over 750 fathers in the USA demonstrated marked differences in the quality of semen from men at different locations and of different ethnic groups. Another paper failed to demonstrate any effects of moderate alcohol consumption during the week before provision of an ejaculate on semen quality and few on serum hormones, of over 8300 men in Europe and the USA. While these observations are interesting, the reasons for regional and ethnic differences in semen quality of fathers are unclear. Although, there was no attempt to confirm the participant-provided level of alcohol consumption, an increase in serum testosterone in the men at the higher end of alcohol intake is compatible with an alcohol effect on liver metabolism, although whether alcohol intake was the cause of higher testosterone, or men with higher androgen levels consume more alcohol, is not known.

Ten years' experience with an external quality control program for semen analysis.

OBJECTIVE: To gauge the performance of laboratories and impact of the German semen analysis external quality control program (QuaDeGA) over its first 10 years. DESIGN: Retrospective analysis of QuaDeGA's twice yearly distribution of fixed semen samples and electronic material documenting sperm motility. Ranking of each participant's responses was determined according to their relation to a "target window." SETTING: Multicenter. PAITENT(S): Healthy donors. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Laboratory performance, World Health Organization (WHO) adherence. RESULT(S): Over 19 runs, there was a steady increase of participants (280 laboratories), the largest group being private urologic practices. Although use of WHO-recommended Neubauer chamber (from 33% to 55%) and diluent (from 11% to 32%) increased, the opposite occurred with morphology staining protocols (from 41% to 19%). Overall, <8% of laboratories truly followed WHO guidelines. Median-based comparisons, replacing reference laboratories, resulted in a merging of performance rankings regardless of the protocols used. CONCLUSION(S): Adherence to WHO recommendations is low, with the majority of laboratories using methods expressly opposed by the guidelines. Participation in QuaDeGA was found to improve the performance of the laboratories involved in the program. However, the use of median-based ranking, while decreasing the extent of variance between laboratories, brings into question the significance of the rankings.

Why are epididymal tumours so rare?

Epididymal tumour incidence is at most 0.03% of all male cancers. It is an enigma why the human epididymis does not often succumb to cancer, when it expresses markers of stem and cancer cells, and constitutively expresses oncogenes, pro-proliferative and pro-angiogenic factors that allow tumour cells to escape immunosurveillance in cancer-prone tissues. The privileged position of the human epididymis in evading tumourigenicity is reflected in transgenic mouse models in which induction of tumours in other organs is not accompanied by epididymal neoplasia. The epididymis appears to: (i) prevent tumour initiation (it probably lacks stem cells and has strong anti-oxidative mechanisms, active tumour suppressors and inactive oncogene products); (ii) foster tumour monitoring and destruction (by strong immuno-surveillance and -eradication, and cellular senescence); (iii) avert proliferation and angiogenesis (with persistent tight junctions, the presence of anti-angiogenic factors and misplaced pro-angiogenic factors), which together (iv) promote dormancy and restrict dividing cells to hyperplasia. Epididymal cells may be rendered non-responsive to oncogenic stimuli by the constitutive expression of factors generally inducible in tumours, and resistant to the normal epididymal environment, which mimics that of a tumour niche promoting tumour growth. The threshold for tumour initiation may thus be higher in the epididymis than in other organs. Several anti-tumour mechanisms are those that maintain spermatozoa quiescent and immunologically silent, so the low incidence of cancer in the epididymis may be a consequence of its role in sperm maturation and storage. Understanding these mechanisms may throw light on cancer prevention and therapy in general.

Vitamin K requirement and reproduction in bromadiolone-resistant Norway rats.

BACKGROUND: Nucleotide polymorphisms in the VKORC1 gene can be linked to anticoagulant rodenticide resistance in Norway rats (Rattus norvegicus Berkenhout). This provides a fitness advantage to rats exposed to anticoagulant actives, but may also cause fitness costs. The vitamin K requirement and reproductive parameters of bromadiolone-resistant rats (Westphalian resistant strain; VKOR variant Tyr139Cys) and bromadiolone-susceptible Norway rats were compared. RESULTS: At vitamin K deficiency, blood clotting times increased in all homozygous resistant males within 8 days and in 80% of homozygous resistant females within 15 days. There was little effect on blood clotting in heterozygous males and no effect in heterozygous females and VKOR wild-type individuals. Litter size was about 20% higher in sensitive pairs compared with resistant pairs. Testes growth, male gonad weight, sperm motility and testis cell concentration were unaffected by the mutation. CONCLUSIONS: The VKOR variant Tyr139Cys causes considerable physiological cost in Norway rats in terms of vitamin K requirement and reproduction. This may affect the distribution and spread of resistant individuals in the wild. Decreased litter size of resistant parents seems to be due to lowered female reproductive performance, as there was no significant effect of the mutation on any aspects of male reproduction considered, but this requires further study.

Semen quality and fertility in adult long-term survivors of childhood acute lymphoblastic leukemia.

OBJECTIVE: To assess testicular function and its determinants in adult survivors of childhood acute lymphoblastic leukemia (ALL) at a median time of 20 years after ALL therapy. DESIGN: Prospective investigation. SETTING: University hospital. PATIENT(S): Fifty-one male long-term survivors and 56 age-matched controls (median age of survivors at ALL diagnosis was 5 years, range: 1 to 15 years, and at the study 29 years, range: 26 to 38 years). INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Testicular size (mean value of both testicular volumes), serum hormone concentrations, semen quality, and number of children fathered correlated with ALL therapy. RESULT(S): Survivors treated with 0-10 g/m(2) of cyclophosphamide had sperm quality and fertility rates comparable with those of controls, but the serum free-testosterone in the survivors treated with cyclophosphamide was lower than in controls (median: 213 pmol/L, range: 189-260 vs. 296 pmol/L, range: 242-338, respectively). Cranial irradiation without cyclophosphamide did not affect semen quality, fertility, or testosterone levels. None of the survivors of a high cumulative dose of cyclophosphamide (>20 g/m(2)) and testicular irradiation (10-24 Gy) had fathered a child. Testicular size was shown to be better than serum inhibin B in predicting nonazoospermic semen samples or fertility. CONCLUSION(S): Treatment of childhood ALL with 0-10 g/m(2) of cyclophosphamide and cranial irradiation does not affect fertility or semen quality but may impair long-term Leydig cell function.