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Biomedical subjects

Pierre Jouannet

Publications and source records attributed to Pierre Jouannet.

15 recordsLinked to original sources
PubMed2006

Zona pellucida from fertilised human oocytes induces a voltage-dependent calcium influx and the acrosome reaction in spermatozoa, but cannot be penetrated by sperm.

BACKGROUND: The functions of three zona glycoproteins, ZP1, ZP2 and ZP3 during the sperm-zona pellucida (ZP) interaction are now well established in mice. The expression of an additional zona glycoprotein, ZPB/4, in humans, led us to reconsider the classical mouse model of gamete interaction. We investigated the various functions of human ZP (hZP) during the interaction of spermatozoa with fertilised and unfertilized oocytes. RESULTS: The hZP of fertilised oocytes retained their ability to bind sperm (albeit less strongly than that from unfertilized oocytes), to induce an intraspermatic calcium influx through voltage-dependent channels similar to that observed with hZP from unfertilized oocytes and to promote the acrosome reaction at a rate similar to that induced by the ZP of unfertilized oocytes (61.6 +/- 6.2% vs 60.7 +/- 9.1% respectively). Conversely, the rate of hZP penetrated by sperm was much lower for fertilised than for unfertilized oocytes (19% vs 57% respectively, p < 0.01). We investigated the status of ZP2 in the oocytes used in the functional tests, and demonstrated that sperm binding and acrosome reaction induction, but not ZP penetration, occurred whether or not ZP2 was cleaved. CONCLUSION: The change in ZP function induced by fertilisation could be different in human and mouse species. Our results suggest a zona blocking to polyspermy based at the sperm penetration level in humans.

Acrosome Reaction↗
PubMed2006

[Gamete and embryo donations].

Medical taking part in procreation in gamete and embryo donation is recent in France and has been included in the field of medically assisted procreation as defined by a law since 1994. Theses activities are strictly regulated. If procreation using donor sperm has been broadly carried out for 30 years in the CECOS leading to the birth of approximately 40,000 children, oocyte and embryo donation had a more recent and limited development. The main questions to which are faced the couples procreating through gamete and embryo donation is whether their child should be told about its origin since they have to build a parenthood and a filiation which are not first depending on biological and genetic links.

Embryo, Mammalian↗
PubMed2006

Results of assisted reproductive technique in men with cystic fibrosis.

BACKGROUND: Sterility in men with cystic fibrosis (CF) raises the question of the use of assisted reproductive techniques (ART). A multidisciplinary network including adult CF centre and reproductive medicine units was set up to answer requests for ART. METHODS: This retrospective study included 25 men with CF between 1994 and 2004. Clinical status, semen analysis, CF mutations analysis and artificial insemination by donor (AID) or ICSI after surgical retrieval of sperm were monitored. RESULTS: All CF men had azoospermia. Two chose AID first (one delivery); 23 chose ICSI. Sperm were surgically retrieved in 21 cases, and ICSI was performed in 19. Pregnancies occurred in 12 of these 19 couples (63%) (two ectopic pregnancies, two spontaneous abortions, one termination of pregnancy for polymalformed twins and 11 single deliveries in nine couples). Two couples tried AID after ICSI failed; one had twins. Another adopted a child, and two had a spontaneous pregnancy. After a follow-up of 4.1+/-2.3 years, two patients died, two underwent lung transplantation and 21 remained stable. CONCLUSION: ART can help men with CF to become a father, but their health status and short survival need careful counselling and multidisciplinary medical care.

Cystic Fibrosis↗
PubMed2005

Hepatitis C virus in the semen of men coinfected with HIV-1: prevalence and origin.

OBJECTIVE: To compare the prevalence of hepatitis C (HCV) RNA in semen from men infected with HCV and those coinfected with HIV-1/HCV and to study the origin of HCV shed in semen. DESIGN: Two prospective studies (HC EP09 and BINECO) included 120 HCV-positive men, 82 coinfected with HIV-1; all had positive HCV RNA detection in blood. METHODS: Paired blood and semen samples were collected for HCV RNA detection and quantification in seminal plasma and in blood serum; repeated semen samples were obtained for 45 men. HCV RNA was sought in spermatozoa and non-sperm cells. Phylogenetic analysis of the HVR-1 region of HCV compared the quasispecies in blood serum and seminal plasma of two men. RESULTS: HCV RNA was more frequently found in the semen of men coinfected with HIV-1 (37.8%) than in those with only HCV infection (18.4%) (P = 0.033). HCV RNA detection in semen was intermittent and was positive in at least one semen sample of 42.8% of HIV-1/HCV-coinfected men who provided repeated samples. Men with HCV-positive semen had significantly higher HCV load in blood than men with HCV-negative semen (P = 0.038). Phylogenetic comparison of HCV quasispecies in blood and in semen showed no evidence of HCV replication in genital leukocytes; however, a phenetic structure was observed between compartments (P < 0.001). CONCLUSIONS: HCV particles in semen originate from passive passage from blood, with preferential transfer of some variants. Nearly half of HIV-1/HCV-coinfected men may intermittently harbour HCV in their semen. Recommendations of protected sex for HIV-infected individuals should be reinforced.

Adult↗
PubMed2005

No partial DAZ deletions but frequent gene conversion events on the Y chromosome of fertile men.

PURPOSE: Recently, partial DAZ deletions on the Y chromosome were identified in infertile men. To determine the clinical importance of partial DAZ deletion, we studied the number of DAZ copies in a well-defined population of 47 fertile men. METHODS: The number of DAZ gene copies was determined by PCR assays, qualitative and quantitative DNA blot experiments. RESULTS: Using semi-quantitative Southern blot, no partial DAZ deletion was detected in fertile men. In many cases, the results were discordant with the PCR assays and qualitative DYS1-blot experiments suggesting that the molecular events detected by the later methods could reflect gene conversion events. Many fertile men present four copies of the DAZ genes but an atypical organization of this DAZ locus. No difference in sperm concentration and motility in the fertile men were observed according to the different DAZ-haplotypes. CONCLUSION: The different DAZ-haplotypes are compatible with normal spermatogenesis.

Adult↗
PubMed2005

Comparison of three in vitro culture systems for maturation of early preantral mouse ovarian follicles.

The aim of this study was to compare three different culture systems for in vitro follicular growth and oocyte maturation in ovarian follicles of mice in order to assess the technique with the optimal growth and improved rate of meiotic maturation. The three systems tested were culture under oil, on a hydrophobic membrane and on agar respectively. Early preantral follicles were cultured for 12 days in alpha-MEM GlutaMAX medium. Follicular growth, oocyte meiotic maturation, oocyte extrusion, atresia and estradiol production were analysed. Follicular development showed two phases in the three systems, with slow growth before day 5 and subsequent acceleration. The percentage of follicles transferred into oocyte maturation medium was significantly higher after culture under oil. The proportion of oocytes that achieved nuclear maturation (metaphase II) was higher when follicles were cultured under oil or on a hydrophobic membrane than on agar. Our results support the use of culture under oil for in vitro follicular growth from the early preantral stage in order to obtain metaphase II oocytes. Fertilization ability of these oocytes and the capacity to obtain healthy mice in a reproducible manner warrants further investigation.

Agar↗
PubMed2005

[Management of priapism in patients with sickle-cell anaemia].

Sickle-cell anaemia is an autosomal recessive hereditary haemoglobinopathy. Patients with sickle-cell anaemia present a high risk of priapism. At least 40% of sickle-cell patients report episodes of priapism. Priapism in patients with sickle-cell tend to start during childhood and rapidly threaten the erectile prognosis. Apart from specific treatment of sickle-cell anaemia, the urologist must be able to recognize forms of intermittent priapism and promote medical prevention. The urologist must also be able to distinguish low-flow priapism from the rarer high-flow priapism, as the treatments differ. Treatment strategies are increasingly well defined, with an increasingly limited place for surgery.

Anemia, Sickle Cell↗
PubMed2004

How can the genetic risks of embryo donation be minimized? Proposed guidelines of the French Federation of CECOS (Centre d'Etude et de Conservation des Oeufs et du Sperme).

Embryo donation is now an acceptable practice which offers new possibilities to many infertile couples wishing to procreate. In France, embryo donation, like gamete donation, is controlled by law, but its application has been poorly developed because too many questions remained unsolved and because of the lack of practical guidelines. Here we report the results of the debate which took place within the Genetics Commission of the French Federation of CECOS and the proposed recommendations which followed, emphasizing the genetic background to be considered for embryo donation.

France↗
PubMed2004

Mutation analysis of the BOULE gene in men with non-obstructive azoospermia: identification of a novel polymorphic variant in the black population.

The BOULE gene is a member of the 'deleted in azoospermia'DAZ family. As in flies and worms, disruption of the BOULE homologues leads to meiotic defects during the first meiotic division, we screened the coding region of the BOULE gene from 40 infertile men with non-obstructive azoospermia or severe oligoasthenoteratozoospermia by denaturing high-pressure liquid chromatography and direct sequencing in order to make progress in elucidating the aetiology of male infertility. Two infertile patients were heterozygous for a novel G to C transversion in exon 2 resulting in a Q2E amino acid substitution. As these two infertile men were from African origin, screening of fertile African subjects identified this novel variant in two fertile male subjects suggesting that this novel Q2E substitution had non-pathologic role. Taking into account the size of our sample, we conclude that BOULE coding sequence mutations are not an important factor in the aetiology of azoospermia.

Amino Acid Sequence↗
PubMed2003

In vitro follicular growth affects oocyte imprinting establishment in mice.

In vitro folliculogenesis of cryopreserved ovarian tissue could be an effective method for insuring fertility for patients who receive gonadotoxic treatment. Although several culture systems have been described for growing female gametes in vitro, the production of competent oocytes for further development remains a considerable challenge. The purpose of our study was to determine whether maternal primary imprinting progresses normally during mouse oocyte growth in vitro. We analysed the DNA methylation status of differentially methylated regions of the imprinted genes H19, Mest/Peg1 and Igf2R using fully grown germinal vesicle-stage oocytes (fg oocytes) produced by in vitro folliculogenesis from early preantral follicles. When compared to fg oocytes removal from control females, we observed after in vitro development, a loss of methylation at the Igf2R locus in six out of seven independent experiments and Mest/Peg1 locus (one out of seven), and a gain of methylation at the H19 locus (one out of seven). These results provide insight into the dysregulation of the process of primary imprinting during oocyte growth in vitro and highlight the need for effective new biomarkers to identify complete nuclear reprogramming competence after in vitro folliculogenesis.

Animals↗
PubMed2003

Deficit in cytochrome c oxidase activity induced in rat sperm mitochondria by in vivo exposure to zidovudine.

A decreased sperm motility has been reported in men treated with nucleoside analog reverse transcriptase inhibitors (NRTI). Sperm motility is correlated with enzymatic activities of the sperm mitochondrial respiratory chain (MRC), which may be impaired by NRTI. We compared sperm and skeletal muscle MRC and citrate synthase (CS) activities, sperm adenosine triphosphate (ATP) content and sperm motility between rats exposed to zidovudine (AZT) for 10 weeks and controls. Decreased levels of CS-normalized cytochrome c oxidase (COX, the MRC complex IV) activity were observed in the spermatozoa from AZT-treated rats, with no significant decrease in ATP content or motility. In muscle absolute COX activity increased after exposure to AZT but CS-normalized COX activity remained unchanged. These results suggest that exposure to NRTI can induce MRC dysfunction earlier in spermatozoa than in skeletal muscle.

Adenosine Triphosphate↗
PubMed2002

Assisted reproduction in HIV-1-serodifferent couples: the need for viral validation of processed semen.

BACKGROUND: Many HIV-infected men and women have a strong desire for a child. Assisted reproductive technologies (ART) are an option for HIV-serodifferent couples to reduce the risk of HIV transmission from an infected man to the woman. Potential HIV contamination of selected spermatozoa after semen processing is an important issue in this context. METHODS: HIV in processed semen obtained in our laboratory since 1995 were analysed. HIV RNA and DNA detection was performed in the selected spermatozoa of 125 men. HIV RNA was analysed in blood and semen plasma as well as HIV DNA in non-sperm cells. RESULTS: HIV RNA and DNA were detected in the selected spermatozoa of eight and two men (6.4% and 1.6%), respectively. HIV RNA was detected with a median load of 5 copies/10(6) spermatozoa. Six of the eight men were untreated, one was taking nucleoside analogue therapy and one was on highly active antiretroviral treatment (HAART). HIV RNA detection was more likely to be positive in selected spermatozoa of men with high seminal plasma viral load. HIV RNA was detected in 26% and 11% of selected spermatozoa fractions when the seminal plasma load was > 10,000 copies/ml and 20-10,000 copies/ml, respectively, but in none when the seminal plasma tested negative. CONCLUSION: Selected spermatozoa may be positive for HIV RNA detection even in treated patients. Viral validation of processed semen is necessary in ART programmes for serodifferent couples, particularly in men with only partially or poorly controlled HIV infection.

Anti-HIV Agents↗
PubMed2002

The human "prion-like" protein Doppel is expressed in both Sertoli cells and spermatozoa.

The prion-like Doppel protein (Dpl) has many biochemical and structural properties in common with the cellular prion protein (PrP(c)), and the physiological role of neither protein is known. Experimental data suggest either direct or indirect interaction between the two proteins. In this study, we investigated the expression pattern and biochemical characteristics of Dpl in human tissues and in Chinese hamster ovary cells transfected with wild-type or variant human Dpl gene constructs. Human Dpl appears to be a glycosylphosphatidylinositol-anchored glycoprotein with N- and O-linked sugars. It was found on Sertoli cells in the testis, on the flagella of epididymal and mature spermatozoa, and in seminal plasma. Dpl coexists only with N-terminally truncated isoforms of PrP(c) on mature spermatozoa. The localization of human Dpl on both Sertoli cells (somatic cells) and spermatozoa (germinal cells) strongly suggests that this protein may play a major role in human male fertility. Finally, our data indicate that spermatozoa are thus an interesting model for studies of the potential interaction between Dpl and PrP(c).

Animals↗
PubMed2002

Human ovarian tissue cryopreservation: indications and feasibility.

BACKGROUND: The cryopreservation of ovarian tissue may enable women exposed to gonadotoxic treatments to have children at a later date. METHODS: Between April 1998 and October 2000, we evaluated the feasibility of long-term ovarian tissue cryopreservation in 51 women who were all at risk of becoming sterile following treatment. RESULTS: Ovarian tissue was not cryopreserved in 20 cases because of the woman's age or premature ovarian failure. In 31 patients, ovarian tissue was frozen by a slow cooling technique using DMSO and sucrose as cryoprotectants. The patients were aged 2.7-34 years and 16 of them were <18 years old. Cryopreservation could be performed in all cases. Ovarian cortex histology was performed for all patients to evaluate the concentration of follicles. The mean number of primordial and primary follicles per mm(2) was 20.36 +/- 19.03 before 10 years of age, 4.13 +/- 2.9 between 10 and 15 years of age and 1.63 +/- 3.35 after 15 years of age. An average mean number of 26 +/- 8.2 ovarian fragments (range 13-50) were cryopreserved per patient for future autografts or for in-vitro growth of follicles. CONCLUSION: Cryopreservation of ovarian tissue may be systematically proposed to young women and girls at risk of becoming sterile as a result of gonadotoxic treatment.

Adolescent↗