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J Parinaud

Publications and source records attributed to J Parinaud.

At least 37 records · Page 2Linked to original sources
PubMed1995

Selection and characterization of human acrosome reacted spermatozoa.

In order to study the characteristics of human acrosome reacted spermatozoa, we developed a method to select them. Spermatozoa, obtained from 20 fertile volunteers, were selected by using GB24 antibody fixed on magnetic immunobeads, after acrosome reaction induced by 50% follicular fluid. Bead-bound spermatozoa were then detached using sheep anti-mouse IGG F(ab')2 antibody. This method allowed recovery of 170 +/- 48 x 10(3) spermatozoa (n = 20), free of GB24 antibody, as assessed by incubation with FITC-rabbit anti-mouse antibody. The percentage of acrosome reacted spermatozoa in the selected population was 88 +/- 3% versus 32 +/- 6% in the whole sperm population. Concerning sperm morphology, the percentage of head abnormalities was lowered (15 +/- 3% versus 20 +/- 3%). The motility of selected spermatozoa was dramatically reduced (7 +/- 3% versus 53 +/- 7% in the whole population) despite no difference in viability (84 +/- 3% versus 80 +/- 4%). However, the viability after an 18 h incubation was very low (1 +/- 0.5% versus 46 +/- 5%). These results show that acrosome reaction occurs in the most morphologically normal spermatozoa and is followed by a loss in motility and a decrease in longevity.

Acrosome↗
PubMed1995

Variations in spontaneous and induced acrosome reaction: correlations with semen parameters and in-vitro fertilization results.

To determine whether variations in spontaneous and induced acrosome reactions are correlated with semen quality, and to identify the inducers of clinical interest, the acrosome reaction, sperm concentration, motility and morphology were recorded in 117 semen samples from patients undergoing an in-vitro fertilization (IVF) attempt. The spontaneous acrosome loss after 24 h incubation in Ménézo B2 medium and after induction by calcium ionophore A23187, progesterone, human follicular fluid, cyclic adenosine 3'-5'-phosphate (cAMP) analogue and phorbol ester (TPA) were measured using the fluorescein isothiocyanate-GB24 antibody. The mean (range) spontaneous acrosome reaction was 3.4 +/- 0.6% (0.0-30.0). Response to the tested inducers was 23.3 +/- 1.6% (0.0-72.0) for calcium ionophore, 5.4 +/- 0.8% (0.0-60.0) for progesterone, 1.0 +/- 0.7% (0.0-24.0) for human follicular fluid, 2.6 +/- 0.7% (0.0-39.0) for the cAMP analogue and 2.3 +/- 0.7% (0.0-31.0) for TPA. The response to calcium ionophore was correlated significantly to sperm concentration, motility and morphology, while the responses to progesterone and TPA were correlated significantly to motility and acrosome morphology. The responses to other inducers were not linked to classic semen parameters. When studying acrosome reaction as a function of IVF results, the responses to calcium ionophore and TPA were discriminant. The results of this study show that the spontaneous acrosome loss and the responses to acrosome reaction inducers are highly variable and partially linked to semen quality. The responses to calcium ionophore and TPA could be of interest in predicting the fertilizing ability in vitro.

Acrosome↗
PubMed1994

Effect of sperm pre-treatments on the results of sub-zonal insemination (SUZI).

Follicular fluid and progesterone, which are present in the natural environment of oocytes, have been reported to induce the acrosome reaction and we compared their use in pretreatment of spermatozoa for human sub-zonal insemination (SUZI). Pre-treatment with follicular fluid (20% v/v) was associated with a higher fertilization rate than pre-incubation with progesterone (1 mmol/l) as assessed by both the embryos/injected oocytes rate (31.7 +/- 6.2% versus 13.5 +/- 5.9%, respectively; P < 0.01) and the male pronuclei/injected spermatozoon rate (10.5 +/- 3.3% versus 3.6 +/- 1.9%, respectively; P < 0.01). Since we have previously reported that pre-treatment with progesterone allowed a higher percentage of live-reacted spermatozoa to be obtained, these results suggest that either progesterone induces modifications of the plasma membrane, which prevent fusion with the oolema, or that follicular fluid not only induces the acrosome reaction but increases the fusion ability by compounds other than progesterone.

Female↗
PubMed1994

Selection and micro-injection of acrosome-reacted human spermatozoa.

A method of selection of acrosome-reacted human spermatozoa is described. Petri dishes were coated with GB24 antibody, specific to the inner acrosomal membrane. The acrosome-reacted spermatozoa were fixed on the antibody and could be removed by aspiration with a micro-pipette. They were then injected into the perivitelline space of hamster eggs in order to check their fertilizing ability. This selection allowed the fertilization rate to be significantly increased (24 versus 7% for control spermatozoa; P < 0.01). This method could enhance the results of human sub-zonal insemination.

Acrosome↗
PubMed1993

Influence of sperm parameters on embryo quality.

OBJECTIVE: To evaluate the influence of sperm defects on embryo quality. DESIGN: Retrospective study. SETTING: In vitro fertilization center. PATIENTS: Embryo transfers (710) from IVF attempts for tubal disease (626) or male infertility (84). MAIN OUTCOME MEASURES: Embryo morphology as a function of causes of infertility, semen, and follicular growth parameters. Embryos were classified into three groups according to their morphology. RESULTS: Transfers of embryos with good morphology were associated to a higher pregnancy rate (34%) than those with intermediate (24%) and poor (10%) morphology. Transfers of embryos with a poor morphology were more frequent (26 of 84 versus 114 of 626) and those with a fair aspect were less frequent (24 of 84 versus 229 of 626) in male infertility than in tubal disease. Embryos with a poor morphology were associated with lower percentage of morphologically normal sperms (62% +/- 19% versus 67% +/- 18%; means +/- SD) and a higher percentage of abnormalities of the postacrosomial region (29% +/- 15% versus 18% +/- 7%). Moreover, sperms with counts < 10 x 10(6)/mL were associated with a lower percentage of embryos with good morphology (18% versus 37%) than sperms with counts > or = 10 x 10(6)/mL. CONCLUSION: Embryo quality is influenced by the semen quality and especially by sperm head abnormalities, suggesting an important role of the male gamete on the early stages of embryogenesis.

Adult↗
PubMed1993

Culture of human preovulatory granulosa cells: effect of extracellular matrix on steroidogenesis.

Human luteal granulosa cells, harvested from preovulatory follicles during in vitro fertilization attempts, were cultured in a serum-precoated substratum ('serum cells') or on a collagen matrix ('collagen cells'). Concerning the 'serum cell' model, E2 secretion was very low in the absence of androgen; when androstenedione was added to the culture medium, cells secreted 180 +/- 52 pmol/ml/24 h of estradiol, 440 +/- 78 pmol/ml/24 h of testosterone and lower quantities of estrone and estriol. Follicle stimulating hormone induced a significant increase in estradiol and estriol, while the secretion of the other steroids was not altered. The secretion of progesterone was 3.15 +/- 1 nmol/ml/24 h and significantly enhanced by luteinizing hormone (+ 95%; P < 0.01). The secretions of 17 alpha-hydroxyprogesterone and 20 alpha-dihydroprogesterone were low and not modified by luteinizing hormone. 'Collagen cells', in basal conditions, showed an increased secretion of estradiol (+ 50%, P < 0.05), became rounded and were less responsive to gonadotropins when compared with 'serum cells'. Thus, the use of a collagen matrix, similarly to gonadotropins, stimulated granulosa cell steroidogenesis in relation to modifications of cell shape. The higher responsiveness of serum cells to gonadotropins makes this model more suitable for physiological and pharmacological studies than the collagen one.

Blood Physiological Phenomena↗
PubMed1993

Comparison between fluorescent peanut agglutinin lectin and GB24 antibody techniques for the assessment of acrosomal status.

In order to compare fluorescent peanut (Arachis hypogaea) agglutinin lectin and GB24 antibody (specific for the inner acrosomal membrane) techniques for the assessment of acrosome reaction, both methods were applied on semen specimens obtained from patients undergoing in-vitro fertilization (IVF). The acrosome status was evaluated after a 4 h incubation in B2 medium with and without calcium ionophore A23187. Results obtained with both techniques were compared and studied as a function of IVF outcome. The percentage of spontaneous acrosome-reacted spermatozoa was higher when assessed by lectin than by GB24 (19 +/- 2% versus 11 +/- 1%; P < 0.001). The difference between the two methods (lectins minus GB24) was significantly higher in abnormal than in normal spermatozoa (10 +/- 2% versus 4 +/- 2%; P < 0.05), but did not significantly correlate with the percentage of acrosomes with abnormal morphology (r = 0.28; NS). When studied in relation to the IVF results, the response to A23187 was higher in successes than in failures (45 +/- 2% versus 34 +/- 4%; P < 0.05) but there was no significant difference between methods. Thus the assessment of acrosome reaction is strongly influenced by the method used, particularly in abnormal spermatozoa. Since the results obtained with lectins were higher in abnormal spermatozoa, GB24 seems to be more effective for assessment of true acrosome reaction.

Acrosome↗
PubMed1993

Effect of clomiphene citrate on sperm cell function.

Experiments were performed to determine time and dose-dependent effects of clomiphene citrate on the function of fertile donor spermatozoa. The percentages of acrosome-reacted, motile and live spermatozoa were assessed. Incubation with clomiphene citrate (1-1000 mumol/l; 1-4 h) induced a dose- and time-dependent increase in the percentage of acrosome-reacted spermatozoa (up to 100%). Acrosome reaction was associated with an impairment of both motility and viability. The maximal value for percentage of live reacted spermatozoa (37 +/- 1%) was obtained when cells were incubated for 1 h with 100 mumol/l of clomiphene citrate. Oestradiol neither affected sperm function when used alone nor inhibited clomiphene action. These results show that clomiphene strongly triggers the acrosome reaction, but that this action is not related to its anti-oestrogenic properties.

Acrosome↗
PubMed1993

Modulation of the steroidogenesis of cultured human granulosa-lutein cells by gonadotropin-releasing hormone analogs.

GnRH analogs are widely used in reproductive medicine to create a hypogonadotropic hypogonadism. However, numerous animal studies have demonstrated a direct regulation of the gonadal function by GnRH. To ascertain this direct ovarian effect in humans, the steroidogenesis of cultured human granulosa cells was studied with or without GnRH and five of its agonists. Buserelin (D-Ser(But)6, desGly10) GnRH ethylamide, leuprorelin (D-Leu6, desGly10) GnRH ethylamide, H4055 (desGly10) GnRH ethylamide, and H4065 (D-Trp6, desGly10) GnRH ethylamide significantly enhanced estradiol secretion. In addition, buserelin induced a significant cell surface decrease that seemed to be mediated by cytoskeleton modifications. The two other molecules, GnRH and triptorelin (D-Trp6) GnRH), had no effect on estrogen secretion at any of the studied concentrations. Thus, despite similar pituitary effects, these agonists did not exhibit the same ovarian action. This may be accounted for by the differences found between pituitary and ovarian receptors. These results suggest that some GnRH analogs can modulate human granulosa cell steroidogenesis at least in the preovulatory period.

Cells, Cultured↗
PubMed1992

Paradoxical ovarian stimulations in the use of LHRH analogs.

In the case of in vitro fertilization, LHRH analogs are used to induce an hypophysary blockage, before the phase of stimulation, via administration of exogenous gonadotropin. During in vitro fertilization attempts using LHRH analogs, the blockage is controlled after 14 days of treatment through measurement of the plasmatic estradiol and pelvic ultra-sonography. In this retrospective study, which concerned 1075 in vitro fertilization cycles, a paradoxical ovarian stimulation with LHRH analogs was observed in 93 cases (8.7%), with high estradiol levels and follicular growth (detected by ultra-sonography), in spite of low FSH and LH levels. In 4 cases, a follicular puncture was performed, which allowed to collect oocytes from which embryos were obtained, thus confirming the observed follicular growth and maturation. The most probable hypothesis explaining this phenomenon seems to be a direct ovarian stimulation, effectuated in vivo by LHRH analogs. This stimulation is only observed in certain patients, and apparently more frequently, with certain LHRH analogs, probably through a variation in the expression of ovarian LHRH receptors.

Estradiol↗
PubMed1992

Paradoxical ovarian stimulations in the use of LHRH analogs.

In the case of in vitro fertilization, LHRH analogs are used to induce a hypophysial blockage before the phase of stimulation, via administration of exogenous gonadotropin. During in vitro fertilization attempts using LHRH analogs, the blockage is controlled after 14 days of treatment by measuring plasmatic estradiol and by pelvic ultrasonography. In this retrospective study, which concerned 1075 in vitro fertilization cycles, a paradoxical ovarian stimulation with LHRH analogs was observed in 93 cases (8.7%) with high estradiol levels and follicular growth (detected by ultrasonography), in spite of low FSH and LH levels. In 4 cases, a follicular puncture was performed, which made it possible to collect oocytes from which embryos were obtained, thus confirming the observed follicular growth and maturation. The most probable hypothesis explaining this phenomenon seems to be direct ovarian stimulation effectuated in vivo by LHRH analogs. This stimulation is only observed in certain patients, and, more frequently it seems, with certain LHRH analogs, which is probably due to a variation in the expression of ovarian LHRH receptors.

Clinical Protocols↗
PubMed1992

Randomized trial of three luteinizing hormone-releasing hormone analogues used for ovarian stimulation in an in vitro fertilization program.

OBJECTIVE: To determine if biochemical differences in luteinizing hormone-releasing hormone analogues (LH-RH-a) have a clinical influence, we studied three of these molecules: buserelin acetate (group B), triptorelin (group T), and leuprorelin (group L). DESIGN: Clinical trial. SETTING: In Vitro Fertilization (IVF) Center. PATIENTS: Two hundred forty-six patients, undergoing their first IVF attempt, were randomly allocated to one group. The analogues were used in a long protocol for ovarian stimulation in an IVF program. RESULTS: After 15 days of LH-RH-a therapy, the follicle-stimulating hormone level was lower in group B (2.9 +/- 1, 4.3 +/- 1.7, 4.8 +/- 2.1 UI/L for B, T, and L groups, respectively; P less than 0.001), although no difference was found in LH and estradiol (E2) levels. After follicular growth stimulation by human menopausal gonadotropins (hMG), E2 level was significantly lower in B group (1,799 +/- 1,101, 2,440 +/- 1,298, 2,137 +/- 1,044 pg/mL for B, T, and L groups, respectively; P less than 0.01), as well as the E2 level per hMG ampule (67 +/- 51, 97 +/- 61, 82 +/- 49 for B, T, and L groups respectively; P less than 0.01). The pregnancy per stimulated cycle rate was not significantly different among the groups. CONCLUSIONS: These results suggest that LH-RH-a could act not only on the pituitary but also on the ovaries. Moreover, these data suggest that buserelin acetate could be preferentially used for high responders and triptorelin for poor responders.

Buserelin↗
PubMed1992

High progesterone concentrations induce acrosome reaction with a low cytotoxic effect.

OBJECTIVE: To determine the optimal conditions to obtain live acrosome-reacted spermatozoa for micromanipulation. DESIGN: Experiments were performed to determine time and dose-dependent effects of calcium ionophore A23187 or steroids on acrosome reaction of fertile donor sperm. The percentages of total reacted and live reacted spermatozoa were assessed with the peanut agglutinin lectin procedure. RESULTS: Incubation with 1 mmol/L progesterone (P) induced 48% +/- 17% acrosome reaction after 6 hours. Motility and viability remained high (49% +/- 3% and 70% +/- 2%, respectively) and thus the percentage of live reacted spermatozoa was 27% +/- 5%. Incubation with A23187 (5 mumol/L for 30 minutes) gave similar results for the percentage of live reacted spermatozoa (26% +/- 4%) but with a lower motility and viability (25% +/- 7% and 53% +/- 2%, respectively; P less than 0.05). CONCLUSIONS: These results show that high concentration of P is an effective way to induce acrosome reaction in preparation for micromanipulation.

Acrosome↗
PubMed1992

Influence of ovarian cysts on the results of in vitro fertilization.

OBJECTIVE: To determine if ovarian cysts are associated with a particular basal endocrine profile and impair follicular growth. DESIGN: Retrospective study. SETTING: In Vitro Fertilization (IVF) Center. PATIENTS: Nine hundred fourteen stimulation cycles stimulated with a combination of luteinizing hormone-releasing hormone analogues (LH-RH-a) and human menopausal gonadotropins (hMG) in a long protocol in an IVF program. RESULTS: After 15 days of LH-RH-a therapy, ovarian cysts (> or = 20 mm) were observed in 8% of cases. These cysts were not related to a particular basal endocrine profile and did not impair follicular growth and IVF results. However, puncturing these cysts enhanced the quality of subsequent follicular growth. On the contrary, cysts appearing during hMG treatment (> or = 25 mm) were related with a lower LH:follicle-stimulating hormone ratio (0.79 +/- 0.52 versus 0.92 +/- 0.74 in absence of cyst) and to a lower ovarian response as assessed by the maximal estradiol level to the total number of hMG ampules ratio (51.6 +/- 36.5 versus 65.9 +/- 47.9 in absence of cyst). However, this difference had no influence on the pregnancy per stimulation rate (18% versus 16% in absence of cyst; not significant). CONCLUSIONS: Results show that the pathogens of ovarian cysts appearing during the blockage phase and during the stimulation phase are different. However, they do not impair the results of IVF, and thus it is not necessary to cancel the attempt in case of ovarian cyst.

Buserelin↗
PubMed1991

The effect of oxytocin on oestradiol-17 beta and testosterone secretion by cultured human granulosa cells.

The effect of oxytocin at different concentrations was tested on the secretion of oestradiol-17 beta and testosterone by cultured human granulosa cells obtained by follicular punctures during in-vitro fertilization (IVF) attempts. Oxytocin had no effect on testosterone secretion, either in the absence or the presence of follicle stimulating hormone (FSH). It had no effect on oestradiol-17 beta in the absence of FSH. However, it decreased the FSH-stimulated secretion of oestradiol-17 beta in a certain number of cases. This inhibitory effect appears to be associated with cells more responsive to FSH and was identified in women found to be successful in achieving pregnancy during IVF attempts.

Androstenedione↗
PubMed1990

Effect of clomiphene citrate on oestrogen secretion by human granulosa cells in culture.

The effect of clomiphene citrate (CC) and 17 beta-oestradiol (E2) on oestrogen secretion was studied in human preovulatory granulosa cells in culture. CC stimulated E2 secretion at 1 and 10 ng/ml (respectively, +36 +/- 14% and +33 +/- 5%) in basal conditions but had no effect on FSH-stimulated E2 secretion. On the other hand, E2 had no effect at any of the tested concentrations (0.1 ng/ml to 1000 ng/ml) on its own production. Since the plasma level of CC obtained in clinical use ranges from 1 to 10 ng/ml, this finding could explain the higher plasma oestrogen levels obtained with CC as compared to human menopausal gonadotrophin.

Androstenedione↗
PubMed1990

Effects of RU486 on progesterone secretion by human preovulatory granulosa cells in culture.

The effects of RU486 on progesterone synthesis were studied in human preovulatory granulosa cells in culture. No effect was observed at 1 and 10 micrograms/mL, but at 100 micrograms/mL, RU486 inhibited the simulation of progesterone secretion induced by LH and cAMP. It is suggested that the main target of RU486 is the cytochrome P450scc function [catalyzing the formation of pregnenolone (D5P) from cholesterol], since no accumulation of D5P or hydroxy derivatives of progesterone was observed. As RU486 is an antiglucocorticosteroid and antiprogesterone agent, the effects of dexamethasone and progesterone were also investigated. Dexamethasone did not modify progesterone secretion, but progesterone inhibited its own synthesis in both the presence and absence of LH. Thus, under these experimental conditions RU486 displayed a progesterone-like effect. However, since the effect of RU486 was observed only at a concentration around 10(-4) M, the mechanism of action may not involve a receptor pathway and may not apply to most clinical circumstances.

Cells, Cultured↗