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J Schoemaker

Publications and source records attributed to J Schoemaker.

At least 55 records · Page 3Linked to original sources

Serological detection of heat shock protein hsp27 in normal and breast cancer patients.

Heat shock protein Mr 27,000 (hsp27) is found in many human breast cancer cells and tissues; its expression is associated with the presence of estrogen receptors, lower cell proliferation, and resistance to certain chemotherapies. The purpose of this study was to assess whether hsp27 may be present in sera from women with primary breast cancer and to know whether autoantibodies to hsp27 may be found in these patients. The study was performed by Western blot analyzing sera from 42 normal premenopausal women, 20 normal postmenopausal women, and 36 breast cancer patients. hsp27 was clearly detected in sera by immunoblotting but only after immunoprecipitation. The mean hsp27 levels in cancer patients were higher than in the control patients; however, 66% of the breast cancer patients showed hsp27 within the normal range, indicating low sensitivity. Moreover, cancer patients with metastatic disease did not show significantly higher hsp27 levels than cancer patients without metastases. Serum hsp27 levels did not correlate with the hsp27 levels in tumor tissues detected by immunohistochemistry. Elevated CA 15-3 levels were not associated with high hsp27 values. Autoantibodies against hsp27 were not detected by immunoblotting in normal sera and in sera from breast cancer patients. As a consequence, serological determination of this biomarker is unlikely to be of utility in the detection and follow-up of breast cancer patients.

Adult↗

The use of oral contraceptives by adolescents for contraception, menstrual cycle problems or acne.

BACKGROUND: Oral contraceptives are prescribed as contraception but also as therapy for menstrual cycle disturbances and acne. We studied the prevalence of oral contraceptive (OC) use and the indications to start OC use among adolescents. METHODS: A cohort consisting of ninth grade secondary school girls (mean age 15.3+/-0.6 (s.d.) years) answered a questionnaire on their menstrual cycle. OC users were asked about duration and reasons for OC-use and the name of the preparation they used. The influence of calendar age, gynecological age and level of education on the prevalence of OC was studied by multiple logistic regression analysis. RESULTS: The response on the questionnaire was 92%. Of 2248 responders 248 (11%) used oral contraceptives: 74% used low dose 'sub 50' preparations, 3% pills with 50 microg estrogen, 3% tri-phase preparations and 17% pills with antiandrogens. Of girls aged 14, 15 and 16 years 4%, 12% and 28% respectively, used OC. Of the 15-year-olds 31% mentioned contraception as most important reason for OC use, 18% menstrual cycle irregularity, 26% dysmenorrhea, 10% acne and 5% other reasons. Calendar age, gynecological age and level of education were independent variables for OC use in general and for OC use for contraception or dysmenorrhea, but less so for OC use for menstrual cycle irregularity or acne. CONCLUSIONS: During adolescence low dose OC's were frequently used. In The Netherlands OC use among girls aged 15 and 16 years doubled in comparison with 1982. One third of the adolescent OC-users mentioned contraception as most important reason to start OC. Gynecological age (a determinant of biological maturation), calendar age (a determinant of biological maturation and lifestyle in peer groups), and level of education (a determinant of lifestyle in peer groups) were associated with OC use.

Acne Vulgaris↗

Hypothetical risks of twinning in the natural menstrual cycle.

Dizygotic (DZ) twinning is likely the result of multiple ovulation upon multiple ongoing follicle growth. Well known conditions with an increased incidence of DZ twinning are a hereditary trait, high maternal age and ovulation induction treatments. These conditions are clearly related to elevation of Follicle Stimulating Hormone (FSH) at the time of peri-menstrual follicle recruitment. In this contribution, we summarize certain other circumstances that may occur in normal women that could increase twinning rate based on the assumption that the elevation of FSH levels is the principal underlying mechanism in DZ twinning. It is hypothesized that recovery from prolonged hypothalamic amenorrhea in part mimics hormonal sequelae of puberty characterized by temporary overshoot of FSH levels. By deduction, such conditions are recovery from lactational amenorrhea, recovery from use of oral contraceptives and recovery of weight loss amenorrhea. According to the literature, these conditions indeed carry the risk of DZ twinning and all show temporary elevated FSH levels. However, prospective experiments will be needed to prove the relation between this type of DZ twinning and possible patterns of serum FSH that mimic puberty under these circumstances.

Amenorrhea↗

Post-menopausal and chronological age have divergent effects on pituitary and hypothalamic function in episodic gonadotrophin secretion.

OBJECTIVE: Ageing is known to reduce gonadotrophin secretion in post-menopausal women. To what extent the hypothalamus and pituitary are involved in this process is not clear. The aim of this study was to compare pulse characteristics of FSH and LH in relation to chronological and post-menopausal age. Base on the gonadotrophin to GnRH, we assessed the extent to which pituitary and/or hypothalamic ageing is responsible for the observed changes. DESIGN: Blood samples were obtained from post-menopausal women every 10 minutes for 6 hours. Subsequently, 100 micrograms GnRH was administered intravenously and blood samples taken after 30, 60 and 90 minutes. PATIENTS: Twenty healthy women aged 47-72 years and between 1 and 30 years after the menopause. MEASUREMENTS: Plasma LH and FSH were measured by immunoradiometric assay. Pulses were identified by a computerized pulse detection program. End points were the mean number and amplitude of pulses, the mean LH and FSH concentrations during the 6-hour study period and the maximal LH and FSH increments following GnRH. RESULTS: Mean LH and FSH levels did not change with chronological age but the LH pulse frequency declined significantly and the response to GnRH increased. Mean LH levels declined with post-menopausal age without alteration in LH pulse frequency but with a significant decrease in pituitary LH response to GnRH. FSH levels remained unchanged. CONCLUSIONS: Post-menopausal ageing seems to have a major suppressive effect on pituitary gonadotroph function, while chronological ageing mainly affects the hypothalamic regulation of LH secretion.

Aged↗

Impaired reproductive function in women treated for growth hormone deficiency during childhood.

OBJECTIVE: There are limited data which suggest that disturbance of reproductive function may occur in GH-deficient women. We have evaluated the consequences of growth hormone (GH) deficiency on reproductive function in women treated for GH deficiency during childhood. DESIGN: Questionnaires were sent to 73 GH-deficient women who had been treated for GH deficiency during childhood. The response rate was 82%. These 60 women were then visited to obtain further information concerning their reproductive status. During these visits, blood samples were obtained from 39 women, to evaluate their hormonal status, and 29 of them had a standard insulin tolerance test (ITT), as part of an adult GH substitution trial. Paediatric and gynaecological records were evaluated in all 60 women. SUBJECTS: Sixty GH-deficient women treated in childhood for this deficiency were included in the study. The median age at follow up was 27 years (range 20-43). GH treatment had been discontinued for 9 years (range 2-26). MEASUREMENTS: In the questionnaire and during the visit, attention was paid to GH treatment, pubertal development, menstrual cycle disturbances and fertility. In the 39 blood samples IGF-1, IGFBP-3, TSH, T4 and T3 were measured. GH responses were measured by a standard ITT. RESULTS: Thirty-four women showed no spontaneous pubertal development. Of the 26 women who did, menarche occurred in 39% at the age of 16 years or older. At the time of the study, menstrual cycles in these 26 women were as follows: 12 had regular menstrual cycles, three had developed secondary amenorrhoea after discontinuation of GH treatment, five had irregular menstrual cycles and six had oligomenorrhoea. The 34 women with disturbed pubertal development and the three with secondary amenorrhoea were infertile because of hypogonadotrophism. Only 13 out of 60 women desired pregnancy or had been pregnant. Three with regular menstrual cycles had primary infertility. Ten had ovulation induced or IVF. Six of these became pregnant after 1-7 cycles. Three were still under treatment, the duration of their treatment varying from 3 to 7 years. One woman discontinued treatment. At the time of the study, nine women had actually conceived. Five out of ten completed pregnancies resulted in Caesarian sections because of cephalo-pelvic disproportion or arrest of labour. During the ITT three of 29 women showed GH responses exceeding 5 micrograms/l (10 mU/l), ruling out complete GH deficiency. Higher GH peaks (NS), IGF-1 (P , 0.01) and IGFBP-3 (P < 0.01) levels were found in women with regular menstrual cycles, compared to women using sex-steroid substitution and amenorrhoeic women. CONCLUSIONS: From this study, it can be concluded that disturbances in reproductive function can be expected in women treated for GH deficiency during childhood, so it is advisable to inform these women of this possibility and to maintain follow-up after discontinuation of GH treatment. Whether the somatotrophic axis exerts a direct effect on ovarian function or whether more severe GH deficiency is more frequently accompanied by disturbances in gonadotrophin secretion still has to be elucidated.

Adult↗

Specific gonadotrophin-releasing hormone analogue binding predominantly in human luteinized follicular aspirates and not in human pre-ovulatory follicles.

In an attempt to resolve the apparent controversy in the observed effects of gonadotrophin-releasing hormone (GnRH) analogues on the ovary, conventional binding studies were conducted with a GnRH agonist and an antagonist in various ovarian tissues to demonstrate possible GnRH receptor binding. In human luteinized granulosa cells derived from unstimulated in-vitro fertilization cycles, high affinity receptor binding was present in 17 out of 24 patients, while binding was not observed in any of the six pre-ovulatory follicles removed during abdominal surgery. Apparently contradictory observations on the direct ovarian effects of GnRH analogues may be the result of the intermittent presence of high affinity GnRH receptors. Our observations indicate that in the human, high affinity ovarian GnRH receptors are present predominantly in ovarian tissue after the luteinizing hormone surge. We also propose the possibility of regulation and activation of a human follicular GnRH receptor in the ovary as a physiological process which may be influenced pharmacologically.

Adult↗

Premature ovarian failure and ovarian autoimmunity.

Premature ovarian failure (POF) is defined as a syndrome characterized by menopause before the age of 40 yr. The patients suffer from anovulation and hypoestrogenism. Approximately 1% of women will experience menopause before the age of 40 yr. POF is a heterogeneous disorder with a multicausal pathogenesis involving chromosomal, genetic, enzymatic, infectious, and iatrogenic causes. There remains, however, a group of POF patients without a known etiology, the so-called "idiopathic" form. An autoimmune etiology is hypothesized for the POF cases with a concomitant Addison's disease and/or oöphoritis. It is concluded in this review that POF in association with adrenal autoimmunity and/or Addison's disease (2-10% of the idiopathic POF patients) is indeed an autoimmune disease. The following evidence warrants this view: 1) The presence of autoantibodies to steroid-producing cells in these patients; 2) The characterization of shared autoantigens between adrenal and ovarian steroid-producing cells; 3) The histological picture of the ovaries of such cases (lymphoplasmacellular infiltrate around steroid-producing cells); 4) The existence of various autoimmune animal models for this syndrome, which underlines the autoimmune nature of the disease. There is some circumstantial evidence for an autoimmune pathogenesis in idiopathic POF patients in the absence of adrenal autoimmunity or Addison's disease. Arguments in support of this are: 1) The presence of cellular immune abnormalities in this POF patient group reminiscent of endocrine autoimmune diseases such as IDDM, Graves' disease, and Addison's disease; 2) The more than normal association with IDDM and myasthenia gravis. Data on the presence of various ovarian autoantibodies and anti-receptor antibodies in these patients are, however, inconclusive and need further evaluation. A strong argument against an autoimmune pathogenesis of POF in these patients is the nearly absent histological confirmation (the presence of an oöphoritis) in these cases (< 3%). However, in animal models using ZP immunization, similar follicular depletion and fibrosis (as in the POF women) can be detected. Accepting the concept that POF is a heterogenous disorder in which some of the idiopathic forms are based on an abnormal self-recognition by the immune system will lead to new approaches in the treatment of infertility of these patients. There are already a few reports on a successful ovulation-inducing treatment of selected POF patients (those with other autoimmune phenomena) with immunomodulating therapies, such as high dosages of corticosteroids (288-292).

Addison Disease↗

Dendritic cells and macrophages in the pituitary and the gonads. Evidence for their role in the fine regulation of the reproductive endocrine response.

Blood monocytes are able to mature into macrophages as well as into dendritic cells. Dendritic cells and macrophages have mainly been studied for their function in the immune response, e.g. in the presentation of antigens to lymphocytes and in the phagocytosis/degradation of unwanted material. The cells are also, however, important producers of a variety of signalling molecules and hormones and are thus involved in other physiological functions such as wound healing, the regulation of the microcirculation and the regulation of the function and growth of endocrine cells. This review summarizes the existing evidence for a regulatory role of dendritic cells and macrophages in the function and growth of hormone-producing cells of the pituitary-gonadal axis. It focuses on the presence, localization and phenotype of dendritic cells and macrophages in the anterior pituitary and the gonads, the endocrine regulatory role of cytokines produced by these cells and the existence of putative feedback mechanisms between endocrine cells of the pituitary-gonadal axis and dendritic cells and macrophages. The recognition of a 'floating endocrine-regulatory force' of monocyte-derived cells that also plays a role in the initiation of immune responses has implications for our understanding of the pathogenesis of gonadal and pituitary autoimmune reactions.

Animals↗

The role of the GnRH dose and the route of administration on treatment outcome and complications.

A literature review is given on the pulsedose, the pulse interval, the route of administration and the complications of pulsatile GnRH therapy in hypogonadotropic patients. It is concluded that the treatment regimen should be as follows: 1. Start first treatment cycle with a pulsedose of 5 micrograms/pulse and a pulse interval of 120 min. 2. Regardless the outcome of the first treatment cycle, during the second cycle either the dose should be increased to 10 micrograms/pulse or the interval should be reduced to 60 min. 3. Only if insufficient results are obtained with this pulsedose should the dose be increased to a maximum of 20 micrograms/pulse. With respect to the route of administration it is concluded that the choice of the i.v. versus the s.c. route of administration is mainly one of personal preference. Complications are mainly local inflammatory reactions. All other side effects and complications are rare and of minor importance.

Drug Administration Routes↗

Two-step gonadotropin-releasing hormone agonist treatment of uterine leiomyomas: standard-dose therapy followed by reduced-dose therapy.

OBJECTIVE: Gonadotropin-releasing hormone agonist-induced partial pituitary suppression with low-grade estrogen production may be useful in long-term treatment of uterine leiomyomas. STUDY DESIGN: Twenty-seven women with uterine leiomyomas were treated with a standard dose of triptorelin for 8 weeks. Patients were then randomized to use 100, 20, or 5 micrograms of triptorelin until week 26. Uterine and myoma size, pituitary-ovarian function, bone metabolism, and bone mineral density were monitored. RESULTS: During standard treatment uterine size was reduced to 67.1% of baseline. During randomized treatment uterine size was further reduced to 57.8% of baseline. There were no differences in overall volume reduction among the groups. Luteinizing hormone and estradiol levels were restored in a dose-dependent way. Bone mineral density decreased significantly in the highest-dose group at week 26. CONCLUSIONS: This study shows that the beneficial effects of initial high-dose agonist treatment on uterine leiomyomas can be preserved by continued low-dose treatment. Bone mineral density does not seem to change during reduced-dose agonist treatment.

Adult↗

The importance of endogenous feedback for monofollicular growth in low-dose step-up ovulation induction with follicle-stimulating hormone in polycystic ovary syndrome: a randomized study.

OBJECTIVE: To evaluate the role of endogenous feedback in monofollicular growth during low-dose gonadotrophin therapy in polycystic ovary syndrome (PCOS) by measuring FSH levels in a group of patients cotreated with a GnRH agonist (GnRH-a) (group B) compared with patients not cotreated with an agonist (group A). DESIGN: Prospective randomized study. SETTING: University tertiary care Reproductive Endocrinology Unit. PATIENTS: Women with clomiphene citrate-resistant PCOS. MAIN OUTCOME MEASURES: Follicle-stimulating hormone, E2, and inhibin levels, follicular growth. RESULTS: In group A, FSH levels decreased significantly from 7.3 mIU/mL (conversion factor to SI unit, 1.00) at day -5 to 5.9 mIU/mL at day 0 (day that hCG was administered) despite a constant dose, whereas they remained at a level of 7.4 mIU/mL in group B. The rate of monofollicular growth was significantly higher in group A (80%) than in group B (22%). No significant differences in E2 levels or inhibin levels were found between the groups. CONCLUSIONS: The absence of a decrease of FSH during GnRH-a treatment in association with a lower rate of monofollicular growth suggests that endogenous feedback during low-dose step-up ovulation induction in PCOS plays an important role. The absence of this feedback mechanism in the presence of normal inhibin levels suggests that negative feedback control by inhibin during follicular stimulation is minimal.

Adult↗

Quantitative MRI of uterine leiomyomas during triptorelin treatment: reproducibility of volume assessment and predictability of treatment response.

Magnetic resonance (MR) imaging is increasingly applied for the quantitative evaluation of uterine leiomyomas. MR is thought to be more accurate in comparison to ultrasound (US) techniques. MR signal intensity (SI) may prove to be predictive of myoma response to GnRH agonist treatment. This study aimed to evaluate the precision of uterine volume assessment by a parallel planimetric MR method and the accuracy of the ellipsoid formula based calculations from MR and US images. It was also attempted to analyze the precision of MR leiomyoma volume measurements and examine the relation between pretreatment myoma SI patterns and the response to agonist therapy. Twenty-seven women with a myomatous uterus were scanned three times during GnRH agonist treatment for 6 months. T1- and T2-weighted, as well as T1 contrast-enhanced sequences of the uterus were obtained in the transverse and sagittal plane. Abdominal US of the uterus was performed with a conventional sector scanner. By the use of a software system for analysis of three-dimensional images obtained by MR, uterine volume was measured by a parallel planimetric method (MR-ROI) as well as the use of the ellipsoid formula (MR-ELL). Myoma volume was assessed by the MR-ROI method. SI of the myomas was estimated from selected tissue samples as well as from the integral myoma region of interest. By abdominal US, volume was assessed by the ellipsoid equation (US-ELL). Within- and between-observer and method reliability (Rw/Rb) was calculated from mean squares obtained by analysis of variance. For uterine volume assessment, reliability between observers and between methods when the MR-ROI and MR-ELL methods were analyzed was excellent. For the US-ELL measurements, the between-observer reliability was limited. Moreover, the reliability of the US-ELL was low when the MR-ROI method was used as the standard. Myoma volume assessment with the MR-ROI method showed high between-observer and between-method agreement. The myoma/fat SI ratio and the mean SI coefficient of variation failed to show a correlation with the degree of response to triptorelin treatment of individual myomas. In MR uterine volume assessment the MR-ELL method is very accurate compared with the more complicated MR-ROI method. The agreement between MR and US is limited. Therefore, the ellipsoid method on MR images is to be regarded as the method of choice for quantitative assessment of uterine volume response to hormonal treatment. Myoma SI patterns were shown to be of no value in the response prediction of myomas to treatment with GnRH agonists.

Antineoplastic Agents, Hormonal↗

The GnRH challenge test: a quantitative measure of pituitary desensitization during GnRH agonist administration.

OBJECTIVE: The use of GnRH agonists for desensitization of the pituitary is widespread in gynaecological practice. For indications such as contraception and treatment of uterine leiomyomata partial desensitization may suffice. With respect to partial desensitization of the pituitary we have addressed three basic questions: (1) Is the degree of pituitary desensitization dependent on the dose of agonist used? (2) What is the optimal way to measure the degree of pituitary desensitization? (3) Is it possible to create a standard to express the degree of pituitary desensitization? DESIGN AND PATIENTS: Twenty-four women were randomized into 4 groups of 6 women. To achieve pituitary desensitization, the groups received 0.1, 0.25, 0.5 and 1.0 microgram/min GnRH respectively, for 6 weeks. MEASUREMENTS: Pituitary desensitization was measured by gonadotrophin levels and responses to a 100-micrograms bolus of GnRH and an oestradiol benzoate challenge-test. RESULTS: The level of LH and the responses of LH and FSH to the GnRH challenge showed significant dose-dependent suppression. Multiple regression indicated the LH response to the GnRH challenge was the best way to measure pituitary desensitization. From the LH responses to the GnRH-challenge a 'standard curve' was established for the assessment of the degree of pituitary desensitization. CONCLUSION: The LH response to the GnRH challenge test is the best available measure of pituitary desensitization during GnRH agonist treatment.

Adult↗

Short term pituitary desensitization: effects of different doses of the gonadotrophin-releasing hormone agonist triptorelin.

Gonadotrophin-releasing hormone agonists (GnRHa) are used to prevent inadequate luteinizing hormone (LH) surges during ovarian stimulation in in-vitro fertilization (IVF). Dose studies for optimal dose assessment are lacking and unfavourable effects of the agonist on granulosa function and oocyte quality have been suggested. This double-blind randomized study was undertaken to assess the effect of four different doses to triptorelin on the degree of desensitization of the pituitary, and the recovery time of pituitary function after withdrawal of the agonist. Sixty-six regularly cycling women were allocated to a treatment group (n = 32) and a control group (n = 34). To assess the degree of pituitary desensitization and restoration in the treatment group, gonadotrophin releasing hormone (GnRH) challenges (100 microg, i.v.) were performed during treatment (day 17), and 2, 4 and 6 days after discontinuation of treatment. At the same time blood samples for oestradiol and triptorelin concentrations were drawn. In the control group a GnRH test was performed on day 2 of the menstrual cycle. Both pituitary desensitization during and pituitary recovery after agonist treatment, expressed as the LH response to exogenous GnRH, appeared to be dose dependent. As the use of reduced dosages still offers a considerable degree of pituitary suppression, studies on dose adjustments in the use of triptorelin, in ovarian stimulation in IVF are warranted.

Adult↗

The role of follicle-stimulating hormone in the selection of follicles in human ovaries: a survey of the literature and a proposed model.

A review of the literature resulted in a model consisting of three follicle-stimulating hormone (FSH)-related mechanisms of follicle selection in the human ovarian cycle. The FSH-dependent selection of dominant follicles is the result of varying FSH serum levels on the one hand, and a varying follicular sensitivity to FSH on the other hand. The first FSH-related mechanism of follicle selection is the intercycle rise of FSH which induces the ongoing development of a reasonable number of follicles during the early follicular phase. The intercycle FSH level should surpass the FSH threshold of the follicles with the highest FSH sensitivity, but the FSH level should not be too high because many other less sensitive follicles might also be stimulated to develop. The second and third mechanisms act together during the mid- to late follicular phase. During the mid- and late follicular phases, the number of dominant follicles is reduced by the synergistic actions of a decreasing FSH level and the differentiation of the follicular sensitivity to FSH. Follicles destined to become dominant gain sensitivity to FSH, whereas follicles destined to become atretic lose their sensitivity to FSH. This differentiation of follicular sensitivity to FSH is the result of several endo-, para- and autocrine factors which modulate the effect of FSH on the growing follicle. The differentiation of follicular sensitivity to FSH supports the effect of the decreasing FSH level. Only the most sensitive follicle will become dominant. The other follicles will become atretic. The presented model may be of use not only for interpretation of the results of ovarian stimulation, but also to put the growing amount of data on growth factors and other substances which modulate the effects of FSH in the dynamic context of follicle selection.

Female↗

[Use of the pill by adolescents for contraception or as therapy].

OBJECTIVE: To describe frequency of oral contraceptive (OAC) use, indications for OAC use and influence of calender age, gynaecological age (age minus age at menarche) and level of education on OAC use among ninth grade secondary school girls. SETTING: Secondary schools in Amstelland-de Meerlanden, a combined urban and rural region to the south of Amsterdam. METHOD: By questionnaire and individual interview on menstrual cycle pattern and OAC use, school girls were asked about duration and reasons for OAC use and what preparation they used. RESULTS: The response to the questionnaire was 92%, that to the interview 83%. Of the 2248 responders 248 (11%; mean age 15.3 years (SD: 0.6)) used OAC: 74% used low dose 'sub 50' preparations, 3% pills with 50 micrograms oestrogen, 3% 3-phase preparations and 17% pills with antiandrogens. Of girls aged 14, 15 and 16 years 4%, 12% and 28%, respectively, used OAC. Of the 15-year-olds 36% mentioned contraception as most important reason, 20% menstrual cycle irregularity, 28% dysmenorrhoea, 12% acne and 5% other reasons. With multiple logistic regression analysis age, gynaecological age and level of education were independent variables for OAC use in general and for OAC use for contraception or dysmenorrhoea, but less so for OAC use for menstrual cycle irregularity or acne. CONCLUSION: During adolescence low dose OACs are frequently used. Of adolescent OAC users 36% mentioned contraception as most important reason. OAC use in the Netherlands among girls aged 15 and 16 years doubled in comparison with 1982. Gynaecological age and calender age (determinants of biological maturation), and level of education (a determinant of life style) were associated with OAC use.

Acne Vulgaris↗

Exploring the recovery phase after treatment with a gonadotrophin-releasing hormone-agonist for ovulation induction in polycystic ovary syndrome: three pilot trials.

OBJECTIVE: Guided by the favorable results of pulsatile gonadotrophin-releasing hormone (GnRH) in the recovery phase after GnRH agonist (GnRH-a) in PCOS, two hypotheses concerning the recovery phase were tested: (1) The resistance to clomiphene citrate will be broken in the recovery phase. (2) Stimulation with (i) a fixed dose of follicle stimulating hormone (FSH) or (ii) with the GnRH-a itself is equally effective in inducing ovulation as pulsatile GnRH. DESIGN: After discontinuation of a 17-21 days GnRH-a treatment, ovulation induction was attempted with clomiphene citrate (CC) or with a fixed dose of FSH or with GnRH-a itself in three separate pilot trials. A previously reported group of 12 patients, treated with pulsatile GnRH in the recovery phase served as control. PATIENTS: Three groups of six patients having PCOS. The group treated with CC was a selected CC-resistant group. RESULTS: No CC-treated patient ovulated. After FSH stimulation two patients ovulated, and one patient ovulated on stimulation with a low dose of the GnRH-a. Endocrine observations in the recovery phase showed an early rise of FSH as compared to the rise of LH and androgens. CONCLUSION: This study could not demonstrate any effect of the recovery phase with respect to facilitation of follicular growth in PCOS. Both tested hypotheses were rejected: (1) The resistance to CC appeared not to be broken by the GnRH-a treatment and (2) subsequent stimulation with FSH or with the GnRH-a itself were not as effective as stimulation with pulsatile GnRH. An extensive further study of the mentioned modalities did not seem feasible.

Adult↗

Pharmacokinetics of follicle-stimulating hormone: clinical significance.

OBJECTIVE: To review studies that examine the pharmacokinetics and pharmacodynamics of endogenous, as well as several exogenous FSH preparations. DESIGN: Related studies were identified through a computerized bibliographic search. PATIENTS: Initial pharmacodynamic studies were done in animal models and in women and men with either hypogonadotropic hypogonadism or suppressed hypothalamic-pituitary-gonadal axis. More recent studies evaluated FSH pharmacokinetics during ovulation induction treatment in women with normal ovulatory cycles or polycystic ovarian syndrome. RESULTS: Various types of FSH exist according to their sialic acid content. High estrogen levels induce the secretion of less sialylated molecules with higher receptor affinity and an increased clearance rate. It appears that there is a threshold FSH level that should be reached to achieve an ovarian response. A very narrow range exists between the threshold and ceiling level for monofollicular growth. This threshold level is surpassed intentionally during IVF treatment cycles to induce multiple follicular recruitment. The threshold level can change under situations such as polycystic ovaries, perimenopause, oral contraceptives, and GnRH analogue treatment. CONCLUSIONS: To avoid the risk of ovarian hyperstimulation syndrome and multiple pregnancies, careful adjustments of serum FSH levels should be made by fine dosage modifications. By monitoring FSH levels and using less sialylated preparations, the efficacy of the treatment probably will improve.

Animals↗