Fertilité et cancer du testicule. Impact des traitements

Objectives

To study the fertility of patients with testicular cancer.

Population and Method

The fertility of a consecutive series of 489 men treated for germ cell tumour of the testis in the Midi-Pyrénées region, between 1978 and 1998, was investigated by means of a questionnaire sent by mail to the patients. A participation rate of 95% was obtained.

Results

Information concerning fertility was obtained for 446 men. 90.1% of patients who had tried to have children prior to their testicular cancer had succeeded, but only 61.8% of men were able to have a child after treatment of their cancer. Radiotherapy and surgery of residual masses appear to be more harmful to fertility than BOE chemotherapy.

Conclusion

The population of men treated for testicular cancer present a high risk of infertility, as the fertility of these men decreases by about 30% after treatment.     

La vitalité des spermatozoïdes

Most of the numerous techniques used to assess sperm viability only have research applications, while only two classical tests, i.e. eosin-Y and hypo-osmotic swelling test (HOST), are currently used in routine sperm analysis to determine the percentage of viable sperm. A viability rate below 50% of living sperm defines necrozoospermia, a condition whose clinical significance is fairly difficult to assess as the mechanisms of sperm cell death are still poorly understood. However, even when a precise cause for necrozoospermia cannot be identified, abnormal viability requires further andrological investigations with particular emphasis on clinical and laboratory signs of chronic infection of the male reproductive tract. Intracytoplasmic sperm injection (ICSI) can yield very good pregnancy rates, even in couples with the most severe forms of male infertility. However, when no motile sperm are available after sperm preparation, the outcome of ICSI is seriously impaired, probably because of a high risk of injecting dead sperm. In these patients, sperm viability could therefore be assessed by the hypo-osmotic swelling test in order to select only viable sperm for ICSI. However, the long incubation time of sperm in the hypo-osmotic solution, as recommended in the classical HOST procedure, has been shown to be detrimental to the spermatozoa. A single sperm test able to assess the viability of each individual spermatozoon within microdroplets covered by mineral oil therefore seems to be preferable. This selection procedure is less suitable in the case of immotile frozen-thawed sperm, as viability does not appear to be reliably predicted by HOST in cryopreserved sperm. Examination of sperm viability now also evaluates programmed cell death or apoptosis, as apoptotic alterations can be detected in spermatozoa by several techniques. The percentage of apoptotic sperm is correlated with deficient sperm parameters and poor outcome of assisted reproductive techniques. More effective selection procedures are therefore needed in order to identify spermatozoa not only with intact membranes but also with an intact genome to be used for ICSI.     

Pollen pool heterogeneity in jack pine (Pinus banksiana Lamb.): a problem for estimating outcrossing rates?

Summary Pollen pool heterogeneity, which violates an assumption of the mixed-mating model, is a major potential problem in measuring plant mating systems. In this study, isozyme markers were used to examine pollen pool heterogeneity in two natural populations of jack pine, Pinus banksiana Lamb., in northwestern Ontario, Canada. Population multilocus estimates of outcrossing rate ranged from 0.83 to 0.95 and differed significantly between populations. Single-tree multilocus outcrossing rates were found to be homogeneous among trees in both populations. Computer simulation studies indicated that a consanguineous pollen pool (pollen gametes related to the mother tree) was capable of biasing population outcrossing estimates downward. Random pollen pool heterogeneity (uncorrelated with maternal genotypes) did not appear to affect population outcrossing estimates in the simulations. Heterogeneity G-tests and Spearman rank tests showed that pollen pool heterogeneity existed in the two natural populations examined; however, it did not have a major effect on population outcrossing estimates, since the consanguineous pollen pool detected was probably a relatively minor component of the outcross pollen pool in both populations. In addition, heterogeneity G-tests were found to be not sensitive in detecting pollen pool heterogeneity caused by consanguineous pollen pool.     

Hochstaudengesellschaften des Landschaftsschutzgebietes Jizerské hory

In the protected landscape region of Jizerské hory Mts., the following tall-herb communitíes of the suballianceFilipendulenion (all.Calthion) were ascertained and studied:Lysimachio vulgari-Filipenduletum Bal.-Tul. 1978.Valeriano officinali-Filipenduletum Siss. inWesthoff et al. 1946,Chaerophyllo hirsuti-Filipenduletum Niemann, Heinrich etHilbig 1973,Cirsio, heterophylli-Filipenduletum Neuhäusl etNeuhäuslová-Novotná 1975, andTrollio altissimi-Filipenduletum Bal.-Tul. inRybní?ek. et al. 1984. Close relationships were found between the communities composition and the environmental factors. Of these, the following were studied: Altitude, substrate, climate, inclination and axposition, moisture, humus content and quality, pH, content of exchangeable H⁺ and Al³⁺, end content of nitrogen. Relations to the reconstructed natural vegetation were also taken into account.     

Activité des groupes de travail

Sans résumé

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Activité des groupes de travail

     

Beltrania penzig : B. magnoliae sp. nov., avec clé d'identification des espèces

Beltrania Penzig : B. magnoliae sp. nov., with a taxonomic key to species. Beltrania magnoliae sp. nov., from decaying leaves of Magnolia gradiflora L. (Magnoliaceae) from south-west of France, is described in vivo and in vitro. It can be distinguished by having one kind of setae, straight sparsely verrucose, conidiophores often branched from the base, separating cells not observed in vivo. A taxonomic key to species in the genus is proposed.     

Anomalies des autosomes et infertilité masculine

Spermatogenesis impairment is frequently associated with autosomal rearrangements. A meiotic study was performed on testicular biopsies of men ascertained through primary fertility and found to be heterozygous for reciprocal translocation, Robertsonian translocations, inversions and extra chromosomes. Pairing failure at meiosis as well as intimate associations between rearranged autosomes and the XY bivalent have been discussed as a cause of gametogenic arrest.