La sélection des spermatozoïdes à fort grossissement permet-elle une diminution de la fréquence des aneuploïdies spermatiques?

Severe male infertility concerns two categories of men. Men with abnormal karyotype, who represent 2 to 14% of infertile men and who can produce sperm cells carrying unbalanced chromosomes related to the patients initial chromosomal reorganization inducing a variable risk of transmission of the abnormality to their conceptus. The second category is men with a normal karyotype but an increased rate of spermatic aneuploidy in a context of severe oligo- and/or asthenozoospermia and men from couples in implantation failure. ICSI is the standard Assisted Medical Reproductive technique for most of these 2 categories despite the obvious increased chromosomal risk. This raises the question of how to morphologically identify sperm cells with abnormal chromosome content during ICSI ? Unfortunately, no relationship has yet been found between sperm morphology in the ICSI sperm fraction (×200) and their chromosome content. Nevertheless, since the end of the 1990s, Bartoov’s team has developed MSOME (Motile Sperm Organelle Morphology Examination) consisting of high-power examination of sperm cells up to × 12,250. This technique was indicated for cases of repeated ICSI failures and appeared to increase pregnancy rates. But was this improvement due to better selection of the chromosomal content of sperm cells to be injected? The present study addressed this question by estimating the value of MSOME in the selection of euploid sperm cells in 2 groups of patients known to have an increased rate of sperm aneuploidy. Group 1 was composed of 2 patients with normal karyotype who presented a macrocephalic sperm syndrome with more than 99% of aneuploid sperm. Group 2 was composed of 11 patients with abnormal karyotype: 6 patients with reciprocal translocation and 5 patients with Robertsonian translocation. The purpose of this study was to compare spermatozoa aneuploidy rates in fresh semen, to those obtained after ICSI selection (×200) and MSOME selection (×6000). Three specific steps of the protocol were (1) all sperm cells selected in MSOME were “top sperm cells“ (2) fixation of selected sperm cell (average loss of 15% during FISH washes) (3) FISH results were validated by two different examiners. FISH analysis of X, Y and 18 chromosomes showed that MSOME eliminates polyploid and diploid sperm cells in patients with macrocephalic sperm syndrome, but the 6 sperm cells selected were all haploid and aneuploid. FISH analysis of X, Y and 18 chromosomes of all other patients did not show any influence of the selection method on the aneuploidy rate. For the 5 subjects with a Robertsonian translocation, the global results of FISH analysis paradoxically showed a significant decrease of the euploidy rate in MSOME selection. The global results of FISH analysis for the 6 patients with mutual reciprocal translocations, showed that the various mutual translocations were not modified between whole sperm and the 2 selection methods. On the other hand, a significant decrease of adjacent 1 and 2 segregation frequency was observed between whole sperm and MSOME selection, associated with a significant increase of 3:1 segregation frequency suggesting that the segregations which modify the structure of chromosomes, for example adjacent 1 and 2 segregations, would induce visible morphological modifications selected by MSOME. We hypothesized that the efficacy of spermatic apoptosis could be modulated by morphology but also by the chromosome contents of the sperm cell. In conclusion, MSOME does not provide any guarantee of the normal chromosome contents of the TOP selected sperm cell. However, these results obtained in a small series of patients suggest that MSOME can eliminate some chromosome abnormalities (adj1 and 2) which would alter sperm nuclear structures.     

Imagerie des glandes annexes de la voie séminale

Ultrasonography (US) is presently routine part of the investigation of infertile men with low volume ejaculate. It provides excellent depiction of the congenital or acquired obstructive lesions of the reproductive system, particulary in its distal part. For 10 years, we performed a US examination of the kidneys, the scrotum contents and transrectal US (TRUS) in every case a excretory cause of male hypofertility could be suspected. In selected patients, MR imaging (with endorectal coil) appears usefull. We describe the normal and abnormal anatomy of the epididymis, vas deferens, seminal vesicle (SV) and ejaculatory ducts in male infertility with US and MRI. Dilatation of the small ducts in the epididymis and sometimes in the testis at scrotal US is suggestive of a downstream obstacle. Sometimes these dilatation could appear as small hypoechoic areas in the epididymis. In contrast, post-inflammatory changes are hyperechoic but often associated with dilatations. TRUS permits to confirm the absence of the vas deferens in congenital bilateral absence of vas deferens (CBAVD): it shows the absence of the ampullae and severe abnormalities of the SV. In case of unilateral absence of the vas deferens, the association with a homolateral kidney agenesis does not lead to the screening for mutations in the cystic fibrosis gene, but suggests a wolffian duct abnormality. MRI (with endorectal coil) is indicated when TRUS is unconclusive. Scrotal US permits to guide semen aspiration and TRUS is indicated to eliminate a distal obstruction when a surgical anastomosis is planed. TRUS (as well as scrotal US) can suggest an obstacle when dilatation of one or several segments of the seminal tract is observed. Sometimes the cause is obvious with imaging: CBAVD, prostatic cyst, inflammatory and post-infectious changes, lithiasis etc. However, it remains many cases where US is only one component of the therapeutic decision, besides clinical examination, sperm count, FSH level and biochemical sperm markers.     

Contribution a la connaissance des propriétés du virus de la densonucléose

Résumé Le virus de la densonucléose est thermorésistant. Il n'est pas inactivé après traitement avec des solvants de lipides. Aucun pouvoir hémagglutinant n'a été mis en évidence avec des érythrocytes d'espèces variées. Ces propriétés sont comparées à celles desParvovirus.

---

Summary The densonucleosis virus is thermoresistant. It is not inactivated after treatment with lipid solvents. Attempts to demonstrate hemagglutination of DNV, using different erythrocytes, were unsuccessful. These properties are compared to those of Parvoviruses.