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A Delbaere

Publications and source records attributed to A Delbaere.

At least 19 recordsLinked to original sources
PubMed2005

Impact of various endocrine and paracrine factors on in vitro culture of preantral follicles in rodents.

Folliculogenesis is a complex process regulated by various paracrine and autocrine factors. In vitro growth systems of primordial and preantral follicles have been developed for future use of immature oocytes, as sources of fertilizable oocytes and for studying follicular growth and oocyte maturation mechanisms. Rodents were often chosen for in vitro follicular culture research and a lot of factors implicated in folliculogenesis have been identified using this model. To date, the mouse is the only species in which the whole process of follicular growth, oocyte maturation, fertilization and embryo transfer into recipient females was successfully performed. However, the efficiency of in vitro culture systems must still be considerably improved. Within the follicle, numerous events affect cell proliferation and the acquisition of oocyte developmental competency in vitro, including interactions between the follicular cells and the oocyte, and the composition of the culture medium. Effects of the acting factors depend on the stage of follicle development, the culture system used and the species. This paper reviews the action of endocrine, paracrine factors and other components of culture medium on in vitro growth of preantral follicles in rodents.

Animals↗
PubMed2004

Acute eosinophilic pneumonia associated with intramuscular administration of progesterone as luteal phase support after IVF: case report.

We report two cases of acute eosinophilic pneumonia induced by i.m. administration of progesterone used as luteal phase support after IVF. For both patients, the symptoms began 3 weeks after the first injection of progesterone. Both patients were in respiratory distress, and one of them required ventilatory assistance for a week, with 5 days in the intensive care unit. Symptoms improved as the i.m. form was shifted to a vaginal form of progesterone together with the administration of corticosteroids. Sesame oil (used as excipient) and benzyl alcohol (used as preservative) could both be incriminated in the development of the hypersensitivity reaction. The need for luteal phase support is clearly established in IVF cycles with GnRH agonist protocols, and progesterone is the generally recommended compound. However, there is no definitive consensus regarding the optimal route of administration of progesterone. These two cases of acute drug-induced disease show that the use of i.m. progesterone can be associated with a severe morbidity in otherwise healthy young patients. This is an additional argument to advocate the use of vaginal progesterone as luteal support in IVF.

Acute Disease↗
PubMed2004

Effect of insulin-like growth factor-I during preantral follicular culture on steroidogenesis, in vitro oocyte maturation, and embryo development in mice.

Insulin-like growth factor-I (IGF-I) is involved in the regulation of ovarian follicular development and has been shown to potentiate the FSH responsiveness of granulosa cells from preantral follicles. The aim of the present study was to investigate the effect of IGF-I during preantral follicular culture on steroidogenesis, subsequent oocyte maturation, fertilization, and embryo development in mice. Preantral follicles were isolated mechanically and cultured for 12 days in a simplified culture medium supplemented with 1% fetal calf serum, recombinant human FSH, transferrin, and selenium. In these conditions, follicles were able to grow and produce oocytes that could be matured and fertilized. The first experiment analyzed the effect of different concentrations of IGF-I (0, 10, 50, or 100 ng/ml) added to the culture medium on the follicular survival, steroidogenesis, and the oocyte maturation process. The presence of IGF-I during follicular growth increased the secretion of estradiol but had no effect on the subsequent oocyte survival and maturation rates. In the second experiment, IGF-I (0 or 50 ng/ml) was added to the culture medium during follicular growth, oocyte maturation, or both, and subsequent oocyte fertilization and embryo development rates were evaluated. Oocyte fertilization rates were comparable in the presence or absence of IGF-I. However, the blastocyst development rate was enhanced after follicular culture in the presence of IGF-I. Moreover, the total cell number of the blastocysts observed after differential labeling staining was also higher when follicles were cultured or matured in the presence of IGF-I.

Animals↗
PubMed2004

New insights into the pathophysiology of ovarian hyperstimulation syndrome. What makes the difference between spontaneous and iatrogenic syndrome?

The recent identification of mutations in the FSH receptor gene, which display an increased sensitivity to hCG and are responsible for the development of spontaneous ovarian hyperstimulation syndrome (OHSS), provides for the first time the molecular basis for the physiopathology of spontaneous OHSS. Based on these recent findings, this paper underlines the differences between spontaneous and iatrogenic OHSS and proposes a model to account for the different chronology between the two forms of the syndrome. In the iatrogenic form, the follicular recruitment and enlargement occur during ovarian stimulation with exogenous FSH, while in the spontaneous form, the follicular recruitment occurs later through the stimulation of the FSH receptor by pregnancy-derived hCG. In both forms, massive luteinization of enlarged stimulated ovaries ensues, inducing the release of vasoactive mediators, leading to the development of the symptoms of OHSS.

Female↗
PubMed2002

[Turner's syndrome and oocyte donation].

This paper reviews literature about oocyte donation for patients with Turner's syndrome and reports the experience of our center. Before contemplating pregnancy, it is essential to perform a careful evaluation of the cardiovascular system, the renal system, the thyroid status and the glucose tolerance. Different studies have reported a suboptimal response of the endometrium of women with Turner's syndrome to oestrogen therapy, and suggested that higher doses of estrogens may be necessary to achieve appropriate endometrial preparation. Pregnancy rate per transfer following oocyte donation is around 30% for patients with Turner's syndrome, comparable to the one observed for patients with other conditions requiring oocyte donation. Miscarriage rate is however higher (40-50%) after oocyte donation in Turner's syndrome, and could be related to the presence of a hypoplastic uterus along with hypovascularization. During pregnancy, cardiovascular complications are potentially the most severe, such as the exacerbation of a preexisting hypertension and the dissection of aortic aneurysms. There is a high rate of Caesarean section among Turner's syndrome patients, the main reason being fetopelvic disproportion. Regarding the increased obstetrical risks in Turner's syndrome patients, the selective transfer of one embryo should ideally be performed in order to avoid additional risks associated with multiple pregnancies. In our center, 9 patients with a Turner's syndrome had 15 cycles of oocyte donation. Five pregnancies were obtained among which three were evolutive. The outcome of oocyte donation cycles were comparable for patients with a Turner's syndrome and for patients with other indications of oocyte donation.

Abortion, Spontaneous↗
PubMed2002

Effect of preantral follicle isolation technique on in-vitro follicular growth, oocyte maturation and embryo development in mice.

BACKGROUND: The use of mechanical and enzymatic techniques to isolate preantral follicles before in-vitro culture has been previously described. The aim of this study was to assess the effect of the isolation procedure of mouse preantral follicles on their subsequent development in vitro. METHODS: Follicles were isolated either mechanically or enzymatically and cultured using an individual non-spherical culture system. Follicular development and steroidogenesis, oocyte in-vitro maturation and embryo development were assessed for both groups. RESULTS: After 12 days of culture, follicles isolated mechanically had a higher survival rate but a lower antral-like cavity formation rate than follicles isolated enzymatically. Enzymatic follicle isolation was associated with a higher production of testosterone and estradiol compared with mechanical isolation. A stronger phosphatase alkaline reaction was observed after enzymatic isolation, suggesting that follicles isolated enzymatically had more theca cells than those isolated mechanically. However, both isolation techniques resulted in similar oocyte maturation and embryo development rates. CONCLUSIONS: Enzymatic follicular isolation did not affect theca cell development. Follicular steroidogenesis was enhanced after enzymatic isolation but the developmental capacity of oocytes was comparable to that obtained after mechanical isolation.

Animals↗
PubMed2002

[The gynecology-obstetrics department].

The scientific and clinical activities of the Department of Obstetrics and Gynaecology have involved the three main subdivisions: the gynecological surgery, the obstetrics and fetal medicine, the endocrinology and the reproductive medicine. Minimal invasive surgery including laser assisted laparoscopy or robotic assisted surgery has been particularly developed. Endometriosis, a frequent and sometimes particularly invasive disease, and oncologic surgeries have been developed in collaboration with the digestive surgery department. The department has also contributed to the comprehension and treatment of prenatal pathologies such as premature labor and deliveries or the gestational diabetes. The department has supported the development of techniques to study the fetal well-being in utero: the prenatal echography, the chorionic villous sampling, the amniotic puncture or the cordocentesis for prenatal genetic diagnosis or fetal infectious contaminations, the CMV transmission more specifically. In endocrinology and reproductive medicine, the department has mainly developed the in vitro fertilization techniques. The prolonged embryo culture, the study of preimplantation embryo metabolism, the preimplantation genetic diagnosis and the cryopreservation of ovarian fragments to preserve fertility in women undergoing oncologic treatments represent the more recent developed topics. Finally, the security of viral transmission in assisted procreation and the treatment of these patients with chronic viral diseases (Hepatitis C or HIV) are another domain with important scientific activity.

Belgium↗
PubMed2001

[Medically assisted reproduction and the desire for a child by HIV infected couples: has the time for a change in attitude come?]].

Today, in developed countries, many HIV-infected people remain in good health thanks to antiviral medication. A growing number of them want to have children. Medical possibilities for preventing contamination of the partners of seropositive men through assisted reproduction and of children thanks to antiviral medicines during pregnancy are summarized. These changes result in ethical considerations which lead the authors to question the conventional systematic medical advise against pregnancy and has encouraged them to assist reproduction for a number of these couples. Today, the balance between the importance of the message of prevention and the benefit for patients of being assisted in their desire for a child has tilted towards medical intervention. It would seem legitimate today to intervene in the most favourable situations rather than see these couples take the risk of spontaneous conception outside health care structures. This implies to adapt medical structure (separate laboratory, appropriate procedure, precise protocols). This approach, which is coherent from the scientific point of view, respects both the autonomy of people carrying HIV as well as the essential interest for the child, in "being" born uninfected and also has the enormous advantage of allowing access to parenthood without destroying the consistency of the message of prevention of sexual contamination.

Anti-HIV Agents↗
PubMed2001

ART in HIV-infected couples: has the time come for a change of attitude?

Today, in developed countries, many HIV-infected people remain in good health thanks to antiviral medication. A growing number of them want to have children. Medical possibilities for preventing contamination of the partners of seropositive men, through assisted reproduction, and of children thanks to antiviral medicines during pregnancy, are summarized. These changes result in ethical considerations which lead the authors to question the conventional systematic medical advice against pregnancy and has encouraged them to assist reproduction for a number of these couples. Today, the balance between the importance of the message of prevention and the benefit for patients of being assisted in their desire for a child has tilted towards medical intervention. It would seem legitimate today to intervene in the most favourable situations rather than see these couples take the risk of spontaneous conception outside health care structures. This implies the need to adapt medical structures (separate laboratory, appropriate procedure, precise protocols). This approach, which is coherent from the scientific point of view, respects both the autonomy of people carrying HIV as well as the essential interests of the child, in being born uninfected, and also has the enormous advantage of allowing access to parenthood without destroying the consistency of the message of prevention of sexual contamination.

Attitude of Health Personnel↗
PubMed1999

Differential response to exogenous and endogenous activin in a human ovarian teratocarcinoma-derived cell line (PA-1): regulation by cell surface follistatin.

The activin/follistatin system is implicated in growth and differentiation of various cell types. Follistatin (FS), through binding and neutralizing activin, plays a major role in the regulation of activin bioavailability. We previously reported that ovarian PA1 cells constitutively secrete FS and show a decreased proliferation rate in response to exogenous activin only if cell surface associated FS is first removed by heparin treatment. These observations suggest that cell-associated FS prevents exogenous activin from accessing its receptor. We hypothesized that cell surface FS would differentially regulate the bioavailability of endogenous and exogenous activin in these cells. To examine the effect of endogenous activin, PA1 cells were stably transfected with an activin betaA-subunit complementary DNA (cDNA). The proliferation rate of five activin-secreting clones was measured by [3H]thymidine incorporation and compared with the proliferation rate of untransfected cells. In clones secreting levels of activin ranging from 22.6 +/- 7.1 to 42.4 +/- 9.9 ng/ml, proliferation was decreased by 31-72% at 96 h of culture, whereas one cell line secreting lower levels of activin (0.4 +/- 0.1 ng/ml) proliferated similarly to the untransfected cells, in which activin was not detectable. To further assess activin signaling, wild-type PA1 cells and activin-secreting clones were transiently transfected with an activin response element-luciferase reporter construct. Basal luciferase activity was 6-fold higher in activin-secreting clones than in wild-type PA1 cells. Exogenous activin (100 ng/ml) increased the transcriptional response of wild-type PA1 cells by 3-fold but did not increase reporter activity in activin secreting clones. Interestingly, the transcriptional response in activin secreting clones was always greater than the basal or activin-stimulated response in wild-type cells. Furthermore, we found that FS was removed from the cell surface by lipofectamine used for these transfections. Therefore, these results show that activation of the luciferase reporter gene occurs under conditions in which proliferation is affected, suggesting that the antiproliferative effect of activin could be due to a direct stimulation of activin signaling pathways. In summary, as opposed to exogenous activin, endogenous activin decreased proliferation of PA1 cells even in the presence of cell surface associated FS. These results are consistent with a model in which FS acts as a barrier for exogenous (endocrine-paracrine) but not for endogenous (autocrine) activin. In addition, the higher PA1 cell responsiveness to endogenous compared with exogenous activin, suggests that activin overexpression in PA1 cells may up-regulate an activin signaling component, or down-regulate an activin signaling inhibitor.

Activins↗
PubMed1999

[In vitro fertilization at the Erasme Hospital: 10 years and 1000 pregnancies later...].

This contribution summarize ten years of in vitro fertilization of clinical work. Activity growth, improvements of results (mean fertilization rate increased from 45% to 58%, fertilization failure dropped from 18% to 7%, pregnancy chances gains 9% to reach 44% per trial) and new treatments possibilities (severe male infertility) thanks to the ICSI technic were the major characteristics of this last ten years. The original anonymous oocyte donation program with donors permutation initiated as soon as 1990 has imposed itself due to it's exceptional efficiency with a pregnancy rate of 95% per oocyte pick up on a population of 46 donors and 145 recipient cycles. Thanks to the large population studied (4028 cycles, 1071 pregnancies), the tendencies in human fecundity (impact of age) and the risks linked to multiples pregnancies could be highlighted, stressing the importance of future developments presented in the other contributions following this general presentation of results.

Adult↗
PubMed1999

[Evolution of ovarian stimulation in in vitro fertilization].

This paper reviews the different treatments of ovarian stimulation for in vitro fertilization (IVF). It emphasizes the recent development of new molecules, including recombinant gonadotrophins and GnRH antagonists. Because of their higher purity, recombinant gonadotrophins are theoretically less immunogenic than the urinary forms. Their preparation mode ensures a better batch to batch consistency. Their clinical use in IVF seems to be associated with a higher number of developing follicules and retrieved oocytes, but pregnancy rates are comparable to those obtained after ovarian stimulation with urinary gonadotrophins. The GnRH antagonists induce a direct inhibition of the pituitary gonadotrophin secretion. In association with an ovarian stimulation with gonadotrophins, they efficiently prevent premature LH surges when administered during the end of the follicular phase. The GnRH antagonists are still in clinical evaluation phase and the optimal protocol and dose still to be defined. They should become available in the coming year. The risks related to the controlled hyperstimulation together with the reduction of the number of transferred embryos has recently led "soft stimulation" to a reevaluation of the stimulation protocols towards a simplified procedure. However, the validity of this attitude could be in opposition with the wish to limit the number of transferred embryos since embryo quality seems to be directly related to the total number of embryos.

Clomiphene↗
PubMed1999

[Aspects of scientific research and technical progress in human fertility].

The development of an outstanding in vitro fertilization program greatly benefits from the contribution of research because it remains an unfailing source of questions on human reproduction, as much in the fields of physiology and pathology as in those of psychology and sociology. This paper shows five major themes that are tackled by the laboratory of biology and psychology of human fertility and the Fertility Clinic, whether it's endocrinology (the ovarian renin and angiotensin regulation), cellular metabolism (embryo metabolism), genetics (preimplantation genetic diagnosis) or cancerology (ovarian tissue conservation before or after chemo- or radiotherapy), all of these are crossed by the fifth (the psychological and ethical aspects of in vitro fertilization) which gives a human dimension to the biological work, since it's a very special biology that it's our own reproduction, the very base of the specie's survival.

Cryopreservation↗
PubMed1998

Short-term medical complications of 1500 oocyte retrievals for in vitro fertilization and embryo transfer.

OBJECTIVE: To evaluate the different short-term complications after in vitro fertilization and embryo transfer. DESIGN: a retrospective study on 7 years in the fertility clinic of an university hospital. MATERIALS AND METHODS: Short-term medical complications were analysed after 1500 transvaginal ultrasonographically guided oocyte retrievals. RESULTS: Ovarian hyperstimulation syndrome (1.8%), pelvic infections (0.4%), intraperitoneal bleeding (0.2%) and adnexal torsions (0.13%) were observed. One case of adnexal torsion occurred during pregnancy (0.18%). Two unusual case of bowel endometriosis were encountered (0.13%). CONCLUSIONS: Short-term medical complications after in vitro fertilization and embryo transfer are rare (2.8%). This contrast with the high rate of multifetal pregnancies which increases maternal and perinatal morbidity and mortality and must be considered as the major complication of in vitro fertilization treatment.

Adnexal Diseases↗
PubMed1997

Features of the Renin-angiotensin system in ascites and pleural effusion during severe ovarian hyperstimulation syndrome.

PURPOSE: The purpose of this work was to investigate the ovarian renin-angiotensin system (RAS) during severe ovarian hyperstimulation syndrome (OHSS) with ascites and pleural effusion. METHODS: Two patients who developed severe OHSS after ovarian stimulation for in vitro fertilization were investigated. Both patients presented ascites and pleural effusion. Blood, ascites, and pleural fluid were simultaneously sampled during therapeutic paracentesis and thoracocentesis. Renin activity, active renin, prorenin, and angiotensin II immunoreactivity (Ang II-ir) were measured simultaneously in plasma, ascites, and pleural fluid. RESULTS: Prorenin, renin activity, active renin, and Ang II-ir levels were much higher than normal plasmatic laboratory norms in the three compartments. Prorenin and Ang II-ir levels were the highest in the ascites, while they were in the same range in the pleural fluid and in the plasma. CONCLUSIONS: The present findings provide additional evidence for the ovarian origin of the prorenin and Ang II-ir in the ascites of severe OHSS.

Adult↗
PubMed1997

Increased angiotensin II in ascites during severe ovarian hyperstimulation syndrome: role of early pregnancy and ovarian gonadotropin stimulation.

OBJECTIVE: To investigate the implications of the ovarian renin-angiotensin system (RAS) in the pathophysiology of the ovarian hyperstimulation syndrome (OHSS) in relation to gonadotropin stimulation and early pregnancy. DESIGN: A controlled clinical study comparing blood and simultaneously sampled peritoneal fluid (PF) from patients with severe OHSS and from controls without OHSS. SETTING: University Hospitals. PATIENT(S): Eleven patients with severe OHSS, 8 patients with ascites of other origin, 9 patients with a first-trimester pregnancy, and 15 patients stimulated with gonadotropins for IVF. MAIN OUTCOME MEASURE(S): Angiotensin II immunoreactivity was measured in blood and PF and analyzed by high-performance liquid chromatography (HPLC) in ascites from OHSS. RESULT(S): Angiotensin II immunoreactivity (pg/mL; mean +/- SE) was highest in the ascites from pregnant OHSS (1,669 +/- 418), reaching levels 5 times higher than in the plasma (331 +/- 61) and 100 times higher than in control ascites (17 +/- 6.7). Angiotensin II immunoreactivity was elevated in the PF during early pregnancy (211 +/- 68) and after gonadotropin stimulation (244 +/- 41) and was higher than in the plasma in both groups. Analysis by HPLC showed that the majority of Ang II immunoreactivity in the ascites of OHSS was because of true Ang II. CONCLUSION(S): Severe forms of OHSS, especially those associated with pregnancy, are consistently characterized by huge concentrations of Ang II immunoreactivity in the ascites, proved to be true Ang II by HPLC analysis. This may be due to the synergistic effects of exogenous and endogenous hCG on the ovarian RAS.

Adult↗
PubMed1997

Prorenin and active renin concentrations in plasma and ascites during severe ovarian hyperstimulation syndrome.

The pathophysiology of ovarian hyperstimulation syndrome (OHSS) remains unclear. Several lines of evidence indicate that OHSS is associated with a stimulation of the renin-angiotensin system (RAS), but its functional significance as well as its role in the pathogenesis of the syndrome are not yet determined. OHSS is associated with high plasma and ascitic concentrations of total renin, renin activity (RA) and angiotensin II (Ang II). Their ovarian or renal origin is, however, still a matter of debate. To clarify these issues further, total renin, active renin, prorenin, RA and aldosterone were measured in plasma and ascites of nine patients who developed severe OHSS after in-vitro fertilization. Blood and ascites were sampled simultaneously during therapeutic paracentesis. Total renin and prorenin concentrations were significantly higher in the ascites (mean concentration +/- SE respectively of 5920 +/- 1430 mIU/l and 5250 +/- 1350 mIU/l) than in the plasma (respectively 3060 +/- 740 mIU/l and 2000 +/- 460 mIU/l) (P = 0.020 and 0.017 respectively). Conversely, active renin and RA concentrations tended to be lower, although not statistically significantly so in the ascites (respectively 670 +/- 190 mIU/l and 47 +/- 11 ng Ang I/ml/h) than in the plasma (respectively 1060 +/- 370 mIU/l and 75 +/- 21 ng Ang I/ml/h). Aldosterone concentrations were significantly higher in the serum (2609 +/- 374 pg/ml) than in the ascites (2025 +/- 347 pg/ml) (P = 0.015). The concentration gradient between plasma and ascites for total renin and prorenin supports the hypothesis of their ovarian origin in ascites and, to a large extent, in plasma, while it is likely that the high plasma active renin and RA concentrations reflect a peripheral activation of the RAS. In conclusion, the present findings are consistent with a marked stimulation of both ovarian and renal RAS during OHSS.

Adult↗