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Y Aubard

Publications and source records attributed to Y Aubard.

At least 37 records · Page 2Linked to original sources
PubMed2000

Hyperhomocysteinemia and pregnancy--review of our present understanding and therapeutic implications.

Homocysteine results from the transmethylation of methionine. Its metabolism depends primarily on three enzymes and several vitamin cofactors. Genetic abnormality in these enzymes or deficiency of these vitamins lead to hyperhomocysteinemia (HHCh). HHCh is usually biologically defined by a fasting value >15 micromol/l. HHCh belongs among the congenital hypercoagulable states and is a long-known vascular disease risk factor. The discovery that HHCh may also be responsible for several pregnancy complications has only recently been made. Studies in this area are still scarce and report on limited numbers of patients. It nevertheless appears clear that HHCh is associated with the syndromes of repeated miscarriage, pre-eclampsia, placenta abruptio, thromboembolic events, neural tube defects, and perhaps with fetal death-in-utero and intra-uterine growth retardation. Supplementation with vitamin B9 can reduce plasma HC levels, and is thus recommended in patients with HHCh. The prevention of thromboembolic events during pregnancy by anticoagulant treatment is also desirable in these patients.

Abortion, Habitual↗
PubMed2000

Comparison of follicle steroidogenesis from normal and polycystic ovaries in women undergoing IVF: relationship between steroid concentrations, follicle size, oocyte quality and fecundability.

Studies of ovarian stimulation for IVF have suggested a relationship between follicle size and pregnancy rates. Furthermore the follicular endocrine environment is correlated with oocyte quality. The aim of this study was first to verify the relationship between follicular steroid content, follicular size, oocyte maturity and fertilization outcome in women with normal ovaries following recombinant human FSH (rhFSH). Secondly this study was extended to women with polycystic ovarian syndrome (PCOS). Fifty-nine patients (31 normal, 28 PCOS) underwent conventional IVF with rhFSH induction. Follicular diameter was classified as small (8-13 mm) or large (>14 mm) and sex steroid content was analysed for each group. Oocyte maturity was studied according to nuclear maturation the day after fertilization. In both ovulation groups, 17 beta-oestradiol and progesterone concentration were significantly higher in large follicles with meiotically competent oocytes compared with those containing meiotically incompetent oocytes. Testosterone levels were increased in PCOS follicles compared with normal patients, with no difference between corresponding sub-groups of follicles with meiotically competent oocytes. The relationship between follicle size and embryo development showed that 14 mm could be a threshold value following rhFSH induction in normal or PCOS women.

Adult↗
PubMed2000

[Heterotopic pregnancy: a report of 5 cases and review of the literature].

Heterotopic pregnancy, also called combined pregnancy, associates extra-uterine pregnancy and intra-uterine pregnancy. We report five cases of heterotopic pregnancy illustrating this condition and reviewed the recent literature from 1994 to 1999. We compared the results of this review with earlier data in the literature from 1971 to 1993. We observed that therapeutic management of the extra-uterine pregnancy and course of the intra-uterine pregnancy have changed little over this period. Conversely, the frequency of heterotopic pregnancy has steadily increased since the development of medically assisted reproduction, although spontaneous cases continue to occur. The diagnosis of heterotopic pregnancy is often difficult as the symptomatology is often misleading. Transvaginal ultrasound generally gives the diagnosis which may be confirmed by laparoscopy, allowing treatment of the extra-uterine pregnancy. Maternal and intra-uterine fetal prognosis depends on early diagnosis which should be made, if possible, prior to termination of the extra-uterine pregnancy.

Adult↗
PubMed2000

[Hyperhomocysteinemia and pregnancy: a dangerous association].

Homocysteine results from the demethylation of the essential amino acid methionine. Its metabolism depends primarily on three enzymes and several vitamin cofactors (vit. B6, B9 and B12). Genetic abnormality in these enzymes or deficiency of these vitamins lead to Hyperhomocysteinemia. Hyperhomocysteinemia belongs among the congenital thrombophilies and is a long-known vascular disease risk factor. The discovery that hyperhomocysteinemia may also be responsible for several pregnancy complications has only recently been made. Studies in this area are still scarce and report on limited numbers of patients. It nevertheless appears clear that HHCh is associated with the syndromes of repeated miscarriage, pre-eclampsia, placenta abruptio, thromboembolic events, neural tube defects, and perhaps with fetal death-in-utero and intra-uterine growth retardation. Supplementation with vitamin B9 can reduce plasma HC levels, and is thus recommended in patients with HHCh. The prevention of thromboembolic events during pregnancy by anticoagulant treatment is also desirable in these patients.

Abortion, Habitual↗
PubMed2000

[Are there indications for cryogenically preserving ovarian tissue in gynecologic oncology?].

One of the essential goals of ovarian tissue cryopreservation is to preserve the fertility of young women who will be undergoing sterilizing anticancer treatments, as cryopreservation of sperm serves in men. However, maturation of gametes after thawing has not yet been realized in humans and pregnancies have only been obtained in animal models. It is nonetheless possible today to cryopreserve the ovarian tissue of patients who have nothing to lose as their follicular reserve would in any case be destroyed or severely depleted by cancer treatment. In gynecologic oncology, ovarian tissue cryopreservation may be performed when curative or prophylactic ovariectomy must be undergone, or when chemotherapy with high-dose alkylating agents is planned, particularly in cases requiring chemotherapy combined with pelvic radiation. These clinical situations may be encountered in young women and especially in girls with early-onset forms of ovarian, cervical, uterine, or vaginal cancers. These situations, nevertheless, remain rare as gynecological cancers occur most often in the post-menopausal woman.

Cryopreservation↗
PubMed1999

Orthotopic and heterotopic autografts of frozen-thawed ovarian cortex in sheep.

Freezing ovarian cortex is a new option to preserve the fertility of young patients undergoing cancer treatment or in women facing premature menopause. However, the best way to use this banked tissue remains unclear. The function of heterotopic and orthotopic autografts of frozen-thawed ovarian cortex of sheep was compared in the present study. Fresh and frozen-thawed fragments of ovarian cortex were autografted on the uterine horn of six ewes (orthotopic grafts) and under the skin of the belly in nine ewes (heterotopic grafts). In both orthotopic and heterotopic grafts, the resumption of follicular growth and ovulation was monitored. In orthotopically grafted ewes, fertility was recorded. Oocytes from both types of grafts were collected, matured and fertilized in vitro. In both fresh and frozen-thawed grafts follicular growth resumed normally; preantral and antral follicles were first detectable 4 and 10 weeks respectively following grafting but only 5% of the primordial follicles appeared to have survived. This confirms that grafting procedures are more deleterious for follicle survival than cryopreservation. Although ovulation resumed in most ewes, none of the ewes grafted orthotopically became pregnant at a synchronized mating. Seven months following grafting, oocytes could be collected from heterotopic and orthotopic grafts, matured and some of them fertilized, but none developed to the blastocyst stage. Heterotopic grafting may be an alternative to orthotopic grafting to preserve fertility provided follicle survival in the grafts is markedly improved.

Animals↗
PubMed1999

Recombinant human follicle stimulating hormone versus human menopausal gonadotrophin induction: effects in mature follicle endocrinology.

To investigate follicular effects of recombinant human follicle stimulating hormone (rhFSH) induction on women with polycystic ovary syndrome (PCOS), steroid content was compared in mature follicles obtained using a long luteinizing hormone-releasing hormone agonist plus rhFSH or human menopausal gonadotrophin (HMG) in PCOS women and controls participating in an in-vitro fertilization programme. Follicular fluids (144 samples) were collected at oocyte retrieval by individual selective aspiration. Oocyte maturity and fecundability were assessed. Plasma and intrafollicular 17beta-oestradiol, progesterone, testosterone concentrations were assayed individually. No significant difference was seen in oocyte maturity and fecundability between PCOS and controls following rhFSH, or between PCOS rhFSH and HMG group. 17beta-oestradiol, testosterone and progesterone concentrations were lower in PCOS follicular fluid following rhFSH than HMG but the difference was not significant. Progesterone concentration, 17beta-oestradiol/progesterone, 17beta-oestradiol/testosterone were significantly different between the two induction groups, for PCOS fertilized oocyte follicles (P = 0.01, P < 0.05 and P < 0.05 respectively). Steroidogenic enzymatic activity seems to be regulated in healthy follicular cells in PCOS as well as in normal patients upon ovarian induction. Following rhFSH, higher PCOS follicular progesterone concentrations leading to a theoretically increased fecundability could suggest that recombinant FSH is a better inducer which needs to be confirmed.

Adult↗
PubMed1998

Cryopreservation of immature human oocytes and ovarian tissue: an emerging technology?

OBJECTIVE: To review the potential for cryopreserving immature follicles either in situ or after isolation from ovarian stroma and to consider the options for fertility by transplantation or in vitro follicle growth. DESIGN: The problems of storing embryos and mature (metaphase II) oocytes were considered in light of the needs of patients to protect fertility before undergoing potentially sterilizing therapy for cancer. The evidence from the experimental biology literature showing that immature oocytes (prophase I) in primordial follicles can be cryopreserved successfully and transplanted to produce fertile eggs was reviewed. The review, which was compiled from MEDLINE and other bibliographic databases, is intended to emphasize the practical opportunities for this technology and the need for future research rather than to be a comprehensive treatment of the subject. CONCLUSION(S): The disappointing results obtained with the cryopreservation of oocytes at metaphase II and ethical concerns about embryo storage are giving impetus to the banking of ovarian tissue for patients who require conservation of fertility. The numbers of needy patients are growing as long-term survivorship after high-dose chemotherapy and bone marrow transplantation rises. More speculatively, if ovarian tissue banking becomes a proven effective method, young, healthy women may request storage of ovarian biopsy samples to keep their reproductive options open in midlife when oocyte fertility is declining. Although the cryotechnology is not yet perfected, the major question now is how to use the tissue most effectively after thawing. For the present, ovarian tissue cryopreservation is still at the experimental stage, but it holds the promise of valuable applications.

Cellular Senescence↗
PubMed1998

Conservation of the follicular population in irradiated rats by the cryopreservation and orthotopic autografting of ovarian tissue.

AIM: To preserve the follicular population in rats prior to abdominal irradiation by the orthotopic autografting of ovarian cortical slices (frozen/thawed) in one of two cryoprotective agents (CPAs). The proportion of follicular survival will be quantified at autopsy and a comparison will be made of the two CPAs. METHOD: Thirty Wistar rats, aged 38-39 days, were unilaterally ovariectomised. The ovaries of twenty animals were slow-cooled in either 1.5 M dimethylsulphoxide (DMSO; group B) or 1.5 M ethylene glycol (EG; group C). The ovaries of the remaining ten animals (group A) were fixed and histologically examined to determine a fresh follicle count. The contralateral ovary was irradiated with a single dose of 2.5 Gy. Frozen tissue (from groups B and C) was thawed rapidly and autografted into the irradiated ovarian bursa. All animals were mated eighteen days after grafting and were sacrificed eighteen days later. At autopsy, the number of embryos was counted and the ovarian weights recorded, before the tissue was prepared histologically for quantification of follicular survival. RESULTS: There was no significant difference in the pregnancy rate in the three groups and, although there was a higher number of embryos in the irradiated control group A compared with groups B and C, the difference was not significant. The follicle count in groups B and C was significantly higher than in group A. In group A, the percentage of growing follicles was higher than in groups B and C and the fresh ovary. CONCLUSIONS: Autografting frozen/thawed ovarian tissue preserved a proportion of the follicular population in irradiated rats. There was no significant difference in the numbers of follicles surviving cryopreservation in the two CPAs. Since the irradiated rats were not totally sterilised, we cannot conclude that cryopreserved grafts can restore fertility.

Animals↗
PubMed1998

Double maternal seroconversion to cytomegalovirus and Toxoplasma gondii.

BACKGROUND: We report the first case of a double maternal seroconversion for Toxoplasma gondii (TG) and cytomegalovirus (CMV) diagnosed during pregnancy. CASE: One case is reported of a female patient referred for seroconversion in response to TG in the 27th week of gestation. A search for foetal involvement revealed signs of non-specific foetal infection without any TG-related lesions. Tests were carried out for another foeto-maternal infectious disease and maternal seroconversion in response to CMV was discovered with virus in the amniotic fluid. The foetus developed hydrocephalus and intracranial calcifications and the pregnancy was terminated at the parents' request. CMV-induced multiple organ involvement without any signs of Toxoplasma gondii-related involvement were noted in the foetus. CONCLUSIONS: This case indicates that a search should be made for another infectious disease likely to involve the foetus when non-specific signs of infection in the foetus are present, even though maternal seroconversion has been recognized.

Adult↗
PubMed1998

[The cervix uteri in pregnancy].

It is during labor that the most dramatic changes to the cervix are apparent, yet the cervix begins its process of adapting early on in pregnancy. From an anatomic perspective, the gravid cervix is changed little in the beginning of pregnancy. It is strikingly less muscular than the rest of the uterus and its connective tissue is comprised essentially of collagen fibers and a matrix rich in proteoglycans. Cervical maturation begins imperceptibly during pregnancy but does not become noticeable until shortly before labor. These changes result from biochemical modifications of the cervical constituents with dissolving of collagen fibers and changes in the respective levels of different proteoglycans. The regulation of this maturation is still poorly understood; steroid hormones, prostaglandins, and collagenases have all been implicated. The effacement and dilatation of the cervix occur with labor. Effacement corresponds with thinning and opening of the internal os and dilatation corresponds with opening of the external os. These phenomena are passive, resulting from physical pressure from fetal engagement under the effects of uterine contractions. Our material understanding of cervical maturation and dilatation are still insufficient, for although we are better and better able to guide the induction and course of labor, it still is impossible for us to arrest premature cervical maturation in the setting of a threatened abortion or premature delivery.

Cervix Uteri↗
PubMed1998

The presence in human serum of a circulating soluble leukemia inhibitory factor receptor (sgp190) and its evolution during pregnancy.

The specific binding of leukemia inhibitory factor (LIF) or oncostatin-M (OSM) to transmembrane gp190 or gp130 leads to their oligomerization which is necessary for signal transduction. Although, sgp190 and sgp130 counterparts also exist, their biological significance remains to be determined. Interestingly, sgp190 forms have been identified in large amounts in normal mouse sera but so far not in human sera. During gestation, murine sgp190 increases 20-fold to 30-fold, while sgp190 RNA levels increase mostly in the liver, uterus and placenta. Sandwich ELISAs were used to detect the presence and follow the evolution of LIF concentrations and its sgp190 receptor subunit in the sera of healthy pregnant and non-pregnant women. The LIF concentrations in whole blood of pregnant women were significantly lower than those of non-pregnant women, whereas they returned to these latter values soon after delivery. In 51 non-pregnant women, the mean sgp190 concentration was 4.3 0.3 ng/ml. It rose slowly but steadily, increasing 4-fold from the 4th to th 34th week of amenorrhea, at which time, it accelerated more rapidly until reaching 41 weeks of amenorrhea, 12 times the mean control value. Several hours prior to delivery, the sgp190 concentration dropped sharply before returning to control levels 2 days later. The marked increase of sgp190 measured in pregnant women extends to humans the observation previously made in mice and suggests a pivotal role for this cytokine system not only during implantation and early embryo development but also throughout pregnancy and more specifically in the biological function of placenta.

Adult↗
PubMed1997

[Early menopause].

Early menopause due to an exhaustion of the ovarian follicles before the age of 40 years occurs in approximately 1% of women in this age range. Clinical signs of estrogen deficiency with amenorrhea and sterility are usually confirmed by hypergonadotrope hypogonadism at laboratory tests. The syndrome is to be differentiated from gonadotrophine resistant ovaries and rare gonadotrope adenomas. Ovary biopsy shows more or less complete destruction of the follicles. There are many causes of early menopause including abnormal number or structure of chromosome X in 15-20% of the cases. Certain metabolic disorders and viral infections can also be incriminated. Finally surgery, radiotherapy or chemotherapy can be the cause of iatrogenic menopause. To determine prognosis, the woman's follicular capacity must be estimated. Estrogen therapy is currently the best choice to preserve chances for ovulation and pregnancy. When there is no remaining follicular capacity, ovum donation may be a solution. Finally, all patients should be given hormone substitution therapy due to the long-term risk of estrogen-progesterone deficiency.

Biopsy↗
PubMed1997

[Primary cytomegalovirus infection and pregnant women: epidemiological study on 1100 women at Limoges].

During 13 months, 1101 women attending for antenatal care at Limoges University Hospital were prospectively studied to determine the prevalence of Cytomegalovirus (CMV) antibodies: 47.9% of these women were CMV seropositive. Ethnic group was strongly associated with CMV status: 42.6% of metropolitan and 94.5% of immigrant women were seropositive. Seropositivity was associated with increasing parity and older age. The risk of a susceptible woman to acquire CMV infection during pregnancy is 0.7%. Among the 4 seroconversions, 3 children were infected, with developmentally and neurologically normal status in one case, moderate ear damage in an other case and a disseminated infection in the third case requiring a provoked abortion.

Adult↗
PubMed1997

[Folates and the neural tube. Review of the literature].

There are two types of neural tube fusion abnormality (NTFA)--craniorachischisis and rachischisis--with a prevalence of 11.2/10,000 in continental Europe. Their prevalence varies widely and is influenced by many factors, including geographical, racial and seasonal components. The transmission of NTFAs is usually polygenic and affected by many factors, and far more rarely of the mendelian monogenic type. The occurrence of NTFAs has been shown to be due to folic acid (FA) deficiency. First suspected in 1965, FA deficiency was proved to be a cause of NTFAs both occurring and recurring in the 1980s. FA deficiency might act by preventing the remethylation of homocysteine to methionine, the latter is known to play an essential role in fusion of the neural tube in animals. Primary prevention of NTFAs therefore requires that FA supplementation be given to women planning a pregnancy and after conception. Two possible ways of preventing FA deficiency can be envisaged, ie. via folic acid supplementation or systemic enrichment of the basic diet. Neither of the two alternatives is sufficient by itself and probably a combination of the two would provide the best means of preventing neural tube defects.

Animals↗