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D Chardonnens

Publications and source records attributed to D Chardonnens.

At least 19 recordsLinked to original sources
PubMed2006

Contraceptive counselling and social representations: a qualitative study.

BACKGROUND: Contraceptive use is a complex issue and several studies have been conducted in an effort to understand user behaviour. It is of interest to explore the representations of professionals who give advice on contraception, since their views could have an impact on contraceptive use. METHODS: Individual in-depth interviews of 65 healthcare professionals likely to provide contraceptive advice to patients at a Swiss maternity unit. RESULTS: 83% of healthcare professionals interviewed were favourable to contraception in general while being highly critical of its practical efficacy. The methods most often spontaneously cited were oral contraceptive pills, male condom, intrauterine devices and hormonal implants. Theoretically, all methods should be proposed during contraceptive counselling but in practice interviewees have different social representations of user groups and associate them with specific contraceptive methods. Personal experience appears to play a bigger role than scientific knowledge. CONCLUSIONS: The counsellor's social representations probably play an important role in determining user behaviour. These representations should be taken into consideration in the training of healthcare professionals in this field.

Adult↗
PubMed2003

Possible interactions between leptin, gonadotrophin-releasing hormone (GnRH-I and II) and human chorionic gonadotrophin (hCG).

Leptin is a metabolic signal to the reproductive axis, where it increases the plasma levels of luteinising hormone (LH) and follicle stimulating hormone (FSH). Since the placental regulation of human chorionic gonadotrophin (hCG) mimics that of the pituitary LH, we undertook this study to see if leptin could be involved in the secretion and synthesis of hCG in first-trimester trophoblast. We incubated cytotrophoblastic cells (CTB) with GnRH-I or GnRH-II, for 4 or 48 h and collected the media at different times thereafter. GnRH-II was more potent than GnRH-I when incubated for 4 h with CTB. Leptin secretion, as measured at 4 h, was significantly stimulated by GnRH-II. When measured at 24 h leptin values were also increased as compared to controls. Neither GnRH-I, nor GnRH-II had any effect on leptin secretion when incubated for 48 h with CTB. Leptin was also added to perifused placental explants, and samples (in which hCG was measured) were collected every 3 min. Leptin significantly stimulated hCG secretion by explants and induced a pulse of hCG immediately (within 6 min) after its injection, increasing significantly the area under the curve (P=0.04) and the amplitude (P=0.02) of hCG pulses. We conclude that GnRH-II is more effective than GnRH-I in stimulating leptin secretion. This difference could be explained by the existence of two different types of placental GnRH receptors or two different pathways of GnRH degradation. Furthermore, we observe that leptin has a significant stimulatory effect on hCG pulsatility.

Chorionic Gonadotropin↗
PubMed2003

Modulation of placental vascular endothelial growth factor by leptin and hCG.

Vascular endothelial growth factor (VEGF) has been identified as an endothelium-specific mitogen and inducer of angiogenesis and endothelial cell survival. Leptin and hCG have also been suggested as possible regulators of angiogenesis in various models. In-vivo and in-vitro assays revealed that leptin has an angiogenic activity and that the vascular endothelium is a target for leptin. Thus, we hypothesized that products of cytotrophoblastic cells may play a role in placental angiogenesis and we therefore investigated the effects of leptin and hCG on cytotrophoblast VEGF secretion. We incubated cytotrophoblastic cells (CTB) with recombinant human leptin (rhLept) (0-4 pg/ml) or hCG (0-30000 IU/ml) for 4 h. rhLept significantly stimulated hCG (P = 0.0045) and decreased VEGF release (P = 0.0008) by CTB in a concentration-dependent manner. On the other hand, increasing concentrations of hCG (0-30000 IU/ml), induced a significant inhibition of leptin secretion (P = 0.0028) and a marked dose-dependent stimulation of VEGF(165) secretion (P < 0.0001). We observed an increase of >1000-fold in basal trophoblastic VEGF secretion with physiological concentrations of hCG in vitro. An inhibitory effect of hCG on trophoblastic leptin secretion was also observed, suggesting that hCG might exert a possible negative feedback on trophoblastic release of leptin. We hypothesize that trophoblastic products such as hCG and leptin are probably involved in the control of VEGF secretion at the maternal-fetal interface.

Chorionic Gonadotropin↗
PubMed2002

Localization of tyrosine phosphorylated proteins in human sperm and relation to capacitation and zona pellucida binding.

Mammalian sperm must undergo a process known as capacitation before fertilization can take place. A key intracellular event that occurs during capacitation is protein tyrosine phosphorylation. The objective of this study was to investigate and visualize protein tyrosine phosphorylation patterns in human sperm during capacitation and interaction with the zona pellucida. The presence of specific patterns was also assessed in relation to the fertilizing capacity of the spermatozoa after in vitro fertilization. Protein tyrosine phosphorylation was investigated by immunofluorescence. Phosphorylation increased significantly with capacitation and was localized mainly to the principal piece of human sperm. Following binding to the zona pellucida, the percentage of sperm with phosphotyrosine residues localized to both the neck and the principal piece was significantly higher in bound sperm than in capacitated sperm in suspension. When the percentage of principal piece-positive sperm present after capacitation was <7%, fertilization rates after in vitro fertilization were reduced. Different compartments of human spermatozoa undergo a specific sequence of phosphorylation during both capacitation and upon binding to the zona pellucida. Tyrosine phosphorylation in the principal and neck piece may be considered a prerequisite for fertilization in humans.

Female↗
PubMed2001

Effects of human hydrosalpinx fluid on in-vitro murine fertilization.

Patients with hydrosalpinges show a decrease of both fertility and clinical outcome of IVF and embryo transfer treatment. Several reports have demonstrated the negative effects of hydrosalpinx fluid (HSF) on embryo development and implantation. The aim of this study was to determine whether human HSF, collected from infertile patients, might exhibit a deleterious effect on gametes and fertilization using a murine IVF system. Murine gametes were co-incubated during IVF until first cleavage with human HSF diluted to 50% from four patients (HSF1-4). It was demonstrated that HSF affected fertilization, as determined by the count of the 2-cell embryos. Pre-incubation of spermatozoa with HSF during capacitation significantly lowered the percentage of 2-cell embryos (P < 0.05). While HSF1-3 had no significant effect on motility and viability of spermatozoa, HSF4 almost completely affected their survival. In contrast, pre-incubation of ovulated oocytes surrounded by their cumulus cells with HSF before IVF did not impede first cleavage. Taken together, these results suggest that HSF has a cytotoxic effect on spermatozoa and/or impairs the fertilization process, probably by altering capacitation/acrosome reaction and/or ligand(s)-receptor(s) interactions. Hydrosalpinges may be partly associated with sterility through HSF inhibitory effects on fertilization.

Animals↗
PubMed2001

Comparison of the effects of GnRH-I and GnRH-II on HCG synthesis and secretion by first trimester trophoblast.

Gonadotrophin-releasing hormone (GnRH) is an important factor in the regulation of the synthesis and secretion of gonadotrophins from the pituitary gland. An isoform of this decapeptide, GnRH-II, with an amino acid sequence 70% homologous to GnRH-I, has been recently described. Since the physiological effects of GnRH-II are not yet known, we undertook the present study to see whether GnRH-II could be involved in the secretion and synthesis of HCG in first trimester trophoblast. We incubated cytotrophoblastic cells (CTB) with GnRH-I or GnRH-II, for 4 or 96 h and collected the media at different times thereafter. We also performed experiments with placental tissue, where GnRH-I or GnRH-II was added to perifused placental explants, and samples were collected every 3 min. Total amounts of human chorionic gonadotrophin (HCG) were measured in all samples by enzyme-linked immunosorbent assay. GnRH-I was more potent than GnRH-II when incubated for 4 h with CTB, as indicated by increased HCG secretion at 8 h and at 24 h. GnRH-I, but not GnRH-II, down-regulated HCG secretion when incubated for 96 h. GnRH-I significantly increased HCG secretion by the explants, while GnRH-II had a lesser effect. Both induced a pulse of HCG immediately after their injection. Our data show that GnRH-I has more effect than GnRH-II on HCG synthesis and secretion. This difference could be explained by different pathways of GnRH degradation, different receptor affinities, or even by different types of placental GnRH receptor.

Cells, Cultured↗
PubMed2000

A case of 45,X Turner syndrome with spontaneous ovulation proven by ultrasonography.

A well-documented case of non-mosaic Turner syndrome, with spontaneous pubertal development and ovulatory cycles is reported. Mosaicism could be excluded both by karyotyping of 172 metaphases of blood lymphocytes and fibroblasts, and by fluorescence in situ hybridization, using an X-centromeric probe, in 200 blood lymphocyte nuclei. This Turner syndrome patient underwent normal pubertal development, with spontaneous menarche at 14 years, followed by regular monthly periods. Hormonal measurements performed during puberty were consistent with the patient's pubertal development. At the age of 26 years the patient was referred for complete fertility evaluation. Detailed hormonal analyses were performed in a given cycle. They showed midluteal phase estradiol and progesterone values within the range corresponding to normal ovulation and corpus luteum function. In the same cycle, pelvic ultrasonography was also performed at days 13, 15 and 18. It demonstrated a spontaneous ovulation, with follicular rupture that occurred between days 15 and 18. This is the first report of a spontaneous ovulation in Turner syndrome evidenced, not only by hormonal analysis, but also by ultrasonographic demonstration of follicular rupture.

Adult↗
PubMed1999

Modulation of human cytotrophoblastic leptin secretion by interleukin-1alpha and 17beta-oestradiol and its effect on HCG secretion.

To investigate the role of leptin during pregnancy, we assessed leptin production by pure cultured human cytotrophoblastic cells (CTB), its regulation by cytokines and 17beta-oestradiol and its effects on human chorionic gonadotrophin (HCG) secretion. Purified CTB from first trimester placenta were incubated in duplicates in the presence or absence of cytokines or 17beta-oestradiol. Medium was harvested on day 2 and the culture stopped on day 4. Results were corrected for protein content of each individual well and expressed as percent of controls per day (mean +/- SEM). Basal CTB leptin production was 25.2 +/- 2.6 (ng/mg prot). In comparison with controls, leptin production was stimulated to 320 +/- 16% (P < 0.0001) and 195 +/- 3.2% (P < 0.0004) by 3 and 10 ng/ml of interleukin-1alpha respectively. 17beta-oestradiol 10(-6) to 10(-9) mol/l increased basal leptin production 5-9-fold, while 10(-5) mol/l had no such effect. Basal CTB HCG secretion was 5722 +/- 1055 (mIU/mg prot). There was a dose-dependent leptin-induced increase in HCG secretion (P = 0.0039) reaching a 5-fold increase with a leptin concentration of 1 microg/ml (P < 0.006). Gonadotrophin-releasing hormone (GnRH) 8.5 x 10(-8) mol/l significantly increased HCG secretion to 140 +/- 21% of controls (P = 0.031). Cetrorelix (0.1 microg/ml) inhibited leptin-induced HCG secretion (P = 0.0028).

Cells, Cultured↗
PubMed1999

Effects of tumour necrosis factor-alpha, interleukin-1 alpha, macrophage colony stimulating factor and transforming growth factor beta on trophoblastic matrix metalloproteinases.

The aim of this study was to determine the effects of tumour necrosis factor alpha (TNF), interleukin-1 alpha (IL-1alpha), macrophage colony-stimulating factor (MCSF) and transforming growth factor beta (TGFbeta) on the secretion of matrix metalloproteinases (MMP), human chorionic gonadotrophin (HCG) and fetal fibronectin (fFN) by purified first trimester cytotrophoblastic cells (CTB) in vitro. CTB were obtained from legal abortions and cultured in vitro in the presence or absence of the different cytokines. Secreted gelatinases were analysed in the culture supernatants by zymography, by measurements of the total gelatinolytic activity and by enzyme immunoassays. HCG and fFN were measured by commercially available immunoassays. TNF increased the total gelatinolytic activity by increasing MMP-9 activity (P = 0.025-0.0177) but decreased MMP-2 activity (P < 0.03) and immunoreactivity (P < 0.05), fFN (P < 0.02) and HCG (P < 0.01). IL-1alpha significantly increased the secretion of fFN (P < 0.02), the activity (P < 0.02) and immunoreactivity (P < 0.05) of MMP-9 but had no effect on the other parameters. MCSF increased MMP-9 immunoreactivity (P < 0.05) and moderately decreased HCG. TGFbeta inhibited total gelatinolytic activity, MMP-9 activity and immunoreactivity, but was without effect on MMP-2 concentrations and activity. TGFbeta decreased HCG (P < 0.041) and increased fFN (P < 0.042). Our results indicate that TGFbeta, TNF and IL-1alpha are important regulators of trophoblastic MMP secretion.

Cells, Cultured↗
PubMed1999

[Blepharophimosis-ptosis-epicanthus inversus associated with infertility].

Blepharophimosis-ptosis-epicanthus syndrome (BPES) is a rare genetic condition occurring sporadically and transmitted by autosomal dominant inheritance. Type I BPES is associated with a high incidence of menstrual irregularities and infertility. Its clinical presentation is attributed to either an ovarian resistance to gonadotropins or to a true premature menopause. Two pathophysiological underlying mechanisms have been proposed: one suggests that one or more mechanisms lead to inhibition of early follicular development or follicule atresia. The other raises the possibility that BPES results from microdeletion of genetic material containing at least 2 independent genes. We report a familial case of BPES identified at birth and who required several surgical procedures. Several members of the patient's family are also affected. Early recognition of this condition may allow appropriate counselling and/or treatments including egg donation in case of hypergonadotropic hypogonadism.

Adult↗
PubMed1998

The apparent late half-life of human chorionic gonadotropin (hCG) after surgical treatment for ectopic pregnancy. A new approach to diagnose persistent trophoblastic activity.

OBJECTIVE: The disappearance kinetic of human chorionic gonadotropin (hCG) follows a biexponential decay with a rapid initial fall followed later by a slow disappearance. This kinetic is characterised by two half-lives: an early and a late. The objective of this study was to determine if and which half-life could be used clinically to detect persistent trophoblast after conservative surgery in patients with ectopic pregnancy. DESIGN: Retrospective analysis of patients having undergone salpingostomy by laparoscopy for an ectopic tubal pregnancy between January 1990 and October 1993. SETTING: Gynaecology Department of an University Hospital. PATIENTS: 104 women with diagnosed tubal ectopic pregnancy were treated by salpingostomy performed under laparoscopy. In seven cases, persistent trophoblast was diagnosed on the basis of plateauing or increasing peripheral hCG values. MAIN RESULTS: From the individual disappearance curves of hCG we calculated the early half-life (early T0.5, from samples obtained between 0 and 48 h postsurgery) and the late half-life (late T0.5, from samples obtained between 2 and 7 days postsurgery). Late T0.5 but not early T0.5 were significantly (P<0.0001 and P=0.416 respectively) longer in women (n =7) in whom a persistent trophoblast was diagnosed. Early T0.5 was dependant on the preoperative value of hCG, whereas late T0.5 was independent. We propose to use late T0.5 as a parameter to follow ectopic pregnancies after treatment.

Chorionic Gonadotropin↗
PubMed1998

Triptorelin acetate administration in early pregnancy: case reports and review of the literature.

When using a long protocol with cycle day 23 gonadotrophin-releasing hormone agonists (GnRH-a) administration, an elevated estradiol level or a missed period 10-14 days after initiating pituitary downregulation should alert the physician to the possibility of a pregnancy. We report 4 pregnancies occurring during pituitary downregulation with Triptorelin acetate in 366 in-vitro fertilization (IVF) cycles resulting in 3 deliveries of 4 normal neonates at term and 1 first trimester abortion. This supports published data reporting a 1% spontaneous pregnancy incidence in women undergoing pituitary desensitization GnRH-a during the luteal phase prior to planned IVF treatment, a 15.9% abortion rate and a 1.7% malformation rate. Our cases together with other published data suggest that pregnancy outcome is not adversely affected by GnRH-a administration during the luteal phase of the conception cycle. However, long term follow-up of these babies is still lacking and the number of reported cases is too small adequately to rule out the possibility of any detrimental effect related GnRH-a administration in pregnancy.

Abortion, Spontaneous↗
PubMed1998

Early cleavage of human embryos to the two-cell stage after intracytoplasmic sperm injection as an indicator of embryo viability.

In-vitro fertilization (IVF) embryos are selected for transfer on the basis of morphology and rate of development. However, when a number of embryos have similar characteristics, the selection of the best embryos is left to chance. Recently, we proposed a simple, novel method to overcome this problem, based on pre-selection of embryos cleaving early to the two-cell stage. In this study we have adopted the same method to choose embryos fertilized after intracytoplasmic sperm injection (ICSI). Fertilized embryos that had cleaved to the two-cell stage by 27 h post-injection were designated as 'early cleavage' embryos, while those that had not yet reached the two-cell stage were designated as 'no early cleavage'. In all cases, the early cleavage embryos were transferred when available. Early cleavage was observed in 54 (61.4%) of the 88 cycles assessed. There were significantly (P = 0.04) more clinical pregnancies in the early cleavage group, 14/54 (25.9%), compared with the no early cleavage group 2/34 (3.2%). No differences between the groups were found when comparing key parameters (age, stimulation protocol and semen characteristics) of the couples. Using the ICSI technique, we have shown that early cleavage to the two-cell stage is not influenced by the timing of fertilization, and is more likely due to intrinsic factors within the oocyte or embryo that promote embryo cleavage after fertilization.

Cleavage Stage, Ovum↗
PubMed1998

The rate of development and time of transfer play different roles in influencing the viability of human blastocysts.

Improved embryo culture protocols now render more feasible the possibility of obtaining human blastocysts after in-vitro fertilization. In this study we present: (i) results of blastocyst development from supernumerary embryos after co-culture on green monkey kidney epithelial cells and (ii) pregnancy rates after transfer of frozen blastocysts. In addition, we have examined the influence of the day of blastocyst freezing and the day of transfer after the luteinizing hormone (LH) peak on pregnancy and implantation rates. Of 423 supernumerary embryos, 200 developed to the blastocyst stage (47.3%). By days 5 and 6, 67% of the blastocysts had reached the blastocyst stage, and were frozen, compared to 28.5% by day 7. When we compared the cases where only blastocysts frozen on days 5 and 6 were transferred compared to those frozen and transferred on or after day 7 the pregnancy rates were 7/18 (38.9%) and 1/16 (6.2%) respectively. In contrast, when we examined the influence of the day of transfer we found that pregnancies were established from day 5 up to day 9 post LH peak. Based on these results, we suggest that every attempt should be made to increase the development rate of supernumerary embryos to the blastocyst stage, as it appears that the quality of blastocysts transferred, as shown in this study by rate of development, plays a more crucial role than the timing of transfer.

Animals↗
PubMed1998

Blastocyst development from supernumerary embryos after intracytoplasmic sperm injection: a paternal influence?

The success of intracytoplasmic sperm injection (ICSI) warrants further study on the role of paternal factors in early human embryogenesis. To investigate whether poor sperm parameters can influence embryo development, we examined the development of ICSI-fertilized embryos to the blastocyst stage. We present results of blastocyst development from supernumerary ICSI embryos after co-culture on monkey kidney epithelial cells. In addition, we compare the development of supernumerary embryos to the blastocyst stage after ICSI and in-vitro fertilization (IVF). Of 168 supernumerary ICSI embryos, 45 (26.8%) developed to blastocysts. Sperm concentration and morphology did not influence blastocyst development. In contrast, blastocysts arose from spermatozoa that had a significantly higher (P = 0.015) forward progressive motility compared with spermatozoa from those patients who failed to produce blastocysts (42.7% versus 28.2%, respectively). Overall the rate of embryo development to the blastocyst stage after ICSI was lower (26.8%) than that after IVF (47.3%). When the rate of blastocyst development was calculated for patients with three or more supernumerary embryos, it remained significantly higher for the IVF patients than for the ICSI patients (45.6% versus 30.0%). There was no significant difference in the mean cell number and quality of the supernumerary embryos between the IVF and ICSI patients. This study confirms previous reports that have postulated that abnormal spermatozoa may manifest a negative paternal effect on preimplantation embryo development.

Blastocyst↗
PubMed1998

Modulation of human chorionic gonadotrophin bioactivity during the first trimester of pregnancy.

The objective of this study was to evaluate the bioactivity of human chorionic gonadotrophin (HCG) during first trimester pregnancy. This was done by means of a retrospective analysis of sera from patients with first trimester normal intrauterine and ectopic pregnancies. Serum samples were obtained from 38 women with amenorrhoea of <10 weeks. From these, 19 had a normal intrauterine pregnancy (IUP) and 19 an ectopic pregnancy (EP). Cases were allocated to either low serum immunoreactive HCG (HCGi), intermediate HCGi or high HCGi concentrations (HCGi <5000 mUI/ml, between 5000 and 40,000 mIU/ml and >40,000 mIU/ml respectively). HCGi and oestradiol were measured by enzyme immunoassays and bioactive HCG by the mouse Leydig cell bioassay. All results were analysed by analysis of variance and unpaired Student's t-test. There was a significant difference between bioactive to immunoreactive HCG ratios (b/i ratio) between the subgroups of low, intermediate and high HCGi concentrations. Lower b/i ratios were found when HCGi concentrations were high (HCG b/i mean +/- SEM: high subgroup, 0.33 +/- 0.07 versus low subgroup: 1.50 +/- 0.12; P < 0.0001). Furthermore, the b/i ratios were inversely correlated with oestradiol (P < 0.0001) and HCGi (P < 0.0001) concentrations but not with gestational age. There was no difference in the b/i ratios when comparing IUP with EP. It is concluded that, in first trimester pregnancies, there is a likely modulation of HCG bioactivity which is inversely correlated with HCGi and oestradiol concentration. The underlying mechanisms and their physiological relevance remain to be elucidated.

Animals↗