Rise In Estradiol Research Articles

Early puberty of farmed tambaqui (Colossoma macropomum): Possible influence of male sexual maturation on harvest weight

Tambaqui is the main native fresh water fish in Brazilian aquaculture. Despite the increasing production of tambaqui (annual growth of approximately 8%), no study has addressed the effects of farming on tambaqui's reproductive physiology and growth performance. As part of an institutional portfolio that aims to increase the production of tambaqui per area of cultivation, the present work details the tambaqui's gametogenesis and steroidogenesis during 10months of farming, until they reached the market size. Spermatogenesis is very precocious (750g fish) and apparently is a rapid and constant process in tambaqui testes, with major concentration of mature fish in August. On the other hand, oogenesis is a much longer process that starts only in fish at around 1200g and does not complete before harvesting (no mature female observed). The plasmatic concentration of sex steroids is very similar among immature male and female tambaqui. However, testosterone and estradiol rise in parallel with testis development while only the second rises with ovarian primary growth. Concentration of 17α-hydroxyprogesterone remains at basal levels during spermatogenesis of farmed tambaqui, but it slightly increases during oocyte primary growth. At harvest, the biometrical analysis reveals that female and male tambaqui yield different gutted weight in the order of 16% in favor of the former. Most probably due to the precocious gonad maturation that farmed males go through (5m old), females are heavier at harvest (12m old) and therefore stand out as the most profitable gender to be produced in the tambaqui farming industry.

The effect of a rise or fall of serum estradiol the day before oocyte retrieval in women aged 40-42 with diminished egg reserve

Purpose: To determine the effect of a drop in serum estradiol the day after injection of human chorionic gonadotropin (hCG) in in vitro fertilization-embryo transfer (IVF-ET) cycles in women aged 40-42 with diminished oocyte reserve. Materials and Methods: Retrospective study with further requirement that the female partner had a day 3 serum follicle stimulating hormone (FSH) of ≥ 12 miU/mL and ≤ five antral follicles. Results: A drop in serum estradiol the day after hCG injection is not associated with a lower chance of pregnancy compared to those women whose serum estradiol increases. However, their chances of releasing the oocyte before retrieval is significantly higher. Conclusions:A drop in serum estradiol in women of advanced reproductive age with diminished oocyte reserve should not signal the need to cancel the retrieval.

The effects of estradiol on mood and behavior in human female adolescents: a systematic review.

Mood disorders and health risk behaviors increase in adolescence. Puberty is considered to contribute to these events. However, the precise impact of pubertal hormone changes to the emergence of mood disorders and risk behaviors is relatively unclear. It is important that inappropriate attribution is not made. Our aim was to determine what is known about the effect of endogenous estradiol on human adolescent girls' mood and behavior. The databases searched were MEDLINE, Embase, PsycINFO, Education Resources Information Center (ERIC), Pre-MEDLINE, Web of Science, and Scopus for all dates to October 2014. For inclusion, contemporaneous hormone and mood or behavioral assessment was required. Data were extracted following a template created by the authors. Fourteen studies met our inclusion criteria. There was some consistency in findings for mood and estradiol levels, with associations between estradiol and depression and emotional tone and risk taking. Results were less consistent for studies assessing other mood and behavioral outcomes. Most studies were cross-sectional in design; assay methodologies used in older studies may lack the precision to detect early pubertal hormone levels. Three longitudinal and several cross-sectional studies indicate potential associations between estradiol and certain mood or affective states, especially depression and mood variability though there are insufficient data to confirm that the rise in estradiol during puberty is causative. We believe that it is important for health professionals to take care when attributing adolescent psychopathology to puberty hormones, as the current data supporting these assertions are limited.

Neurokinin B: a new player in immune/inflammatory stress-mediated suppression of reproduction.

Both immune/inflammatory and psychosocial stressors have profound effects on suppressing reproduction. Suppressing reproduction in times of stress, such as when fighting infection, or due to other environmental factors such as overcrowding, is an important shift of survival functions for a species, especially those with longer gestation periods or parental investment in rearing of offspring (1). Among other effects on reproduction, stress acts through glucocorticoids to decrease LH pulsatile secretion (2, 3). Immune/inflammatory stress, such as that induced by lipopolysaccharide (LPS) derived from Gramnegative bacteria, suppresses the GnRH and LH surge during the early preovulatory estradiol rise in sheep (4), and this suppression is independent of prostaglandins (5). In contrast, prostaglandins are mediators of LPS-induced suppression of GnRH and LH pulsatile secretion during the luteal phase in ewes (6). Cortisol treatment mimics the suppressive effects of LPS, but blocking cortisol production does not prevent LPS-induced suppression of LH pulses (7). Until now, it has not been clear which neural pathways mediate stress-induced suppression of GnRH and LH. Neurons in the arcuate nucleus of the hypothalamus coexpress kisspeptin, neurokinin B (NKB), and dynorphin A (8). Of the peptides produced by the arcuate kisspeptin, NKB, dynorphin (KNDy) neurons, NKB appears unique in differentially modulating GnRH and LH secretion based on the steroid milieu. Both NKB and a selective neurokinin-3 receptor (NK3R) agonist have differential effects on GnRH and LH secretion, depending on the gonadal state of the subjects treated (9). For example, in female gonadal-intact, estradiol-treated rats and sheep, and pubertal rats, NKB or NK3R agonist treatment increases GnRH and LH secretion, whereas in ovariectomized rats, these same treatments suppress GnRH or LH secretion (reviewed in Reference 9). During fasting, another type of stressor, the increase of LH in response to NK3R agonist treatment is even greater in pubertal rats compared with ad libitum feeding (10). In contrast, responses to kisspeptin or dynorphin or agonists that bind to their cognate receptors, G protein-coupled receptor 54 and -opioid receptor (KOR), respectively, are more consistent across the reproductive cycle (8). In this issue, Grachev et al (11) report the results of a series of experiments that link the suppression of reproduction by immune/inflammatory stress with the NKB/ NK3R pathway in female rats. They first determined whether NK3R or KOR, the receptor for which dynorphin has the greatest affinity, were necessary for the LPS-induced suppression of LH pulses or increases in corticosterone (CORT) concentrations (11). Administration of the KOR antagonist nor-BNI did not reverse the effects of LPS on either LH pulsatility or CORT secretion, whereas the NK3R antagonist (SB222200) did reverse the suppression of LH pulsatility, although CORT remained elevated (11). This suggests that immune/inflammatory stress acts upstream of NKB to increase CORT secretion, and the effects of CORT on LH pulsatility are at least in part mediated through NK3R-containing neurons (11). Administration of LPS stimulates other factors involved in the immune/inflammatory response, including prostaglandins and ILs (12). In sheep, blocking prostaglandin synthesis reverses the LPS-induced suppression of LH in the luteal (6) but not the follicular phase (5). In women with polycystic ovary syndrome, a disorder including failure to ovulate and development of large cystic

Developmental programming: Prenatal BPA treatment disrupts timing of LH surge and ovarian follicular wave dynamics in adult sheep

Developmental exposure to BPA adversely affects reproductive function. In sheep, prenatal BPA treatment induces reproductive neuroendocrine defects, manifested as LH excess and dampened LH surge and perturbs early ovarian gene expression. In this study we hypothesized that prenatal BPA treatment will also disrupt ovarian follicular dynamics. Pregnant sheep were treated from days 30 to 90 of gestation with 3 different BPA doses (0.05, 0.5, or 5mg/kgBW/day). All female offspring were estrus synchronized and transrectal ultrasonography was performed daily for 22days to monitor ovarian follicular and corpora lutea dynamics. Blood samples were collected to assess preovulatory hormonal changes and luteal progesterone dynamics. Statistical analysis revealed that the time interval between the estradiol rise and the preovulatory LH surge was shortened in the BPA-treated females. None of the three BPA doses had an effect on corpora lutea, progestogenic cycles, and mean number or duration of ovulatory and non-ovulatory follicles. However, differences in follicular count trajectories were evident in all three follicular size classes (2–3mm, 4–5mm, and ≥6mm) of prenatal BPA-treated animals compared to controls. Number of follicular waves tended also to be more variable in the prenatal BPA-treated groups ranging from 2 to 5 follicular waves per cycle, while this was restricted to 3 to 4 waves in control females. These changes in ovarian follicular dynamics coupled with defects in time interval between estradiol rise and preovulatory LH release are likely to lead to subfertility in prenatal BPA-treated females.

Individualized Treatment from Theory to Practice: The Private Case of Adding LH during GnRH Antagonist-based Stimulation Protocol.

The study evaluated the proportion of patients whose pituitary glands respond with a sharp decrease in luteinizing hormone (LH) levels when exposed to a conventional dose of 0.25 mg gonadotropin releasing hormone (GnRH) antagonist in a prospective, single-center, non-randomized, proof-of-concept study. Fifty women eligible for in vitro fertilization (IVF) received recFSH (Gonal-F) from day 2 or 3 of menstrual period. Basal estradiol, progesterone, and LH were measured on the same day and 4–5 days later—immediately before GnRH antagonist 0.25 mg administration, and 24 hours after its administration. Responders were defined as “normal” if 24 hours after the first GnRH antagonist injection, LH level was ≥50% of the pre-injection level and as “over-suppressed” if it was <50% of the pre-injection level. Twelve patients (26% of the total) were “over-suppressed” with a mean LH level of 37% of the level 24 hours earlier. These patients also demonstrated a significant decrease in estradiol rise during the first 24 hours after initial antagonist administration. This effect was reversed for the rest of the stimulation period during which recLH (Luveris, 150 IU/day) was added to the “over-suppressed.” If proven advantageous in terms of pregnancy rate, this approach to individualized treatment would be easy to implement. Trial registration: ClinicalTrials. gov Identifier: NCT01936077.

Aromatase inhibitor treatment with an intravaginal device and its effect on pre-ovulatory ovarian follicles in a bovine model.

BackgroundLetrozole, a non-steroidal aromatase inhibitor, prevents the body from producing its own estrogen. The objectives of the present study were to test the hypotheses that letrozole treatment, initiated prior to selection of the preovulatory dominant follicle, will induce the growth of more than one follicle to a pre-ovulatory size, and will delay ovulation.MethodsPost-pubertal beef heifers were given two luteolytic doses of PGF (12 h apart) and monitored by ultrasonography for ovulation. Five to eight days later, ovarian follicular wave emergence was synchronized by ultrasound-guided transvaginal follicular ablation (Day 0=wave emergence) and a luteolytic dose of PGF was given 60 and 72 h later. On Day 1, heifers were divided randomly into two groups (n=15/group) and an intravaginal device containing 1 g of letrozole or a blank device (control) was inserted. The intravaginal devices were removed on Day 7, or at the time of ovulation, whichever occurred first. Transrectal ultrasonography and blood sample collection were performed daily from the day of ablation to 12 days after subsequent ovulation.ResultsThe mean (+/-SEM) interval from device placement to ovulation was longer in letrozole-treated animals compared to controls (6.1+/-0.25 vs 5.1+/-0.26 days, respectively; P<0.01). Single dominant follicles were present in both groups. The day-to-day diameter profiles of the dominant follicles of the ovulatory wave were larger (P<0.05) and the maximum diameters greater in letrozole-treated heifers (14.6+/-0.51 vs 12.4+/-0.53 mm, respectively; P<0.01). The diameter profile of the corpus luteum (CL) that formed after treatment did not differ between groups; however, plasma progesterone concentrations were higher (P<0.01) in heifers treated with letrozole. Estradiol concentrations were reduced following letrozole treatment (P<0.05), although a preovulatory rise of estradiol occurred in both groups.ConclusionsAdministration of letrozole with an intravaginal device during growth of the ovulatory follicle delayed ovulation by 24 h and resulted in the formation of a CL that secreted higher levels of progesterone. A sustained-release intravaginal device may be useful for the development of an aromatase inhibitor-based protocol to control ovulation for herd synchronization and to enhance fertility by increasing circulating progesterone concentrations during the first 7 days post-ovulation in cattle.

Effect of multiparity on morphometry and oestrogen receptor expression of pelvic and perineal striated muscles in rabbits: is serum oestradiol relevant?

ObjectiveTo determine changes in morphometry and expression of oestrogen receptors (OR) in the pubococcygeus and bulbospongiosus muscles, and the concentration of serum oestradiol associated with multiparity. Study designTwelve chinchilla-breed female rabbits were divided into multiparas who had undergone four consecutive deliveries and age-matched virgin nulliparas. Pubococcygeus and bulbospongiosus muscles were surgically removed from each rabbit and processed histologically. Fibre cross-sectional area, number of peripheral nuclei, and expression of ORα and ORβ were measured for each muscle. Serum samples were obtained and the concentration of serum oestradiol was quantified. ResultsMultiparity increased (p≤0.05) fibre cross-sectional area and the number of peripheral nuclei per fibre in pubococcygeus muscle, but not in bulbospongiosus muscle. Expression of both ORα and ORβ was high (p≤0.05) in both muscles from multiparous rabbits. A rise in serum oestradiol was measured at the end of the second pregnancy, which was absent (p≤0.05) at the end of the fourth pregnancy. The concentration of serum oestradiol was similar (p>0.05) in nulliparous and multiparous rabbits. ConclusionsMultiparity caused morphometric changes in pubococcygeus muscle but not in bulbospongiosus muscle. As OR expression was high for both muscles, some properties related to fibre composition or muscle physiology could be affected. The finding that serum oestradiol was not elevated at the end of the fourth pregnancy could be related to changes in pelvic and perineal muscles associated with multiparity.

Fertility preservation in young breast cancer patients: addressing individual patient needs

SUMMARY In female patients, infertility may be regarded as an essential loss of femininity and infertility after cancer, and is known to be associated with psychosocial distress. Fertility preservation is thus an important issue for young women diagnosed with breast cancer. Nevertheless, breast cancer patients have traditionally not been offered the most well-established methods for fertility preservation, such as embryo and oocyte freezing, as a rise in estradiol during standard stimulation protocols has been regarded as potentially deleterious in these patients. Alternative protocols for stimulation, such as those using tamoxifen and aromatase inhibitors, have therefore been developed. Protocols including aromatase inhibitors have been demonstrated to be more effective than those using tamoxifen in terms of the number of oocytes and embryos obtained, while maintaining estradiol levels within the normal range of a menstrual cycle. Cryopreservation of immature oocytes and ovarian cortical tissue are methods that are still under development. Reports of children born after application of these experimental methods are currently increasing and these methods are thus gaining a place within the options for fertility preservation in breast cancer patients.

As proteínas de relógios e o eixo hipotálamo-hipófise-gonadal de fêmeas de roedores

The components of hypothalamus-pituitary-gonadal axis release their products in a circadian-temporal window; this is crucial for the reproductive success in either spontaneous or inducible ovulators. The preovulatory surge of luteinizing hormone (LH) is preceded by a hypersecretion of the gonadotrophin-releasing hormone (GnRH). In rodents, it is already known that the timed, preovulatory activation of GnRH-secreting neurons depends on a complex interacting neuroendocrine mechanism involving two cyclic signals: an ovarian estradiol rise in plasma levels during the follicular phase of the estrous cycle and a neural signal from the suprachiasmatic nuclei (SCN). Evidences supporting the hypothesis that the hypothalamic-pituitary axis function depends on the integrity of an autoregulatory loop of expression of clock proteins on each of its components are increasing. This review discusses these evidences

Earlier Puberty in Girls, or Earlier Pubertal Changes? The Hormone Story

Recent studies have noted earlier onset of pubertal changes in girls. Earlier studies have noted increases in adrenal hormones prior to increases in the sex steroids in the peripubertal period. It is unclear if or how these events are related to each other, except through this temporal relationship. Longitudinal observation study, conducted between the years 2004-2011. Participants were recruited between ages 6 and 7, and seen every six months. Trained and certified female examiners evaluated height, weight, and maturation status, and a fasting blood specimen was collected. Serum was analyzed for selected hormones every six months, beginning 30 months prior to, and extending to 6 months after, breast development. Androstenedione, estradiol, estrone, and testosterone serum concentrations were measured by high performance liquid chromatography (HPLC) with tandem mass spectrometry. Dehydroepiandrosterone-sulfate (DHEAS) and sex hormone binding globulin (SHBG) were also measured. There were 252 girls included in the analyses. Serum concentrations of DHEAS rose 24 months before breast development; androstenedione and estrone between 12 to 18 months before breast development; whereas estradiol and testosterone rose, and SHBG fell between 6 to 12 months before breast development. Girls with greater body mass index had lower concentrations of estradiol at onset of breast development as well as six months after pubertal onset. The rise in serum estrone and DHEAS concentrations occurred prior to serum estradiol concentrations, and the rise in serum estradiol occurred prior to breast development. Similar to postmenopausal women, peripubertal girls appear to have peripheral conversion of adrenal androgens to estrone prior to pubertal onset, which could account for earlier age of pubertal changes without earlier activation of the hypothalamic-pituitary-ovarian axis. An additional mechanism would be the exposure to a class of endocrine disrupting chemicals called obesogens, resulting in an increase in adipocyte number and/or adipocyte dysregulation.

Abolition of endocrine dimorphism in hyperthyroid males? An argument for the positive feedback effect of hyperoestrogenaemia on LH secretion

Our aim was (i) to investigate the hypothalamo-hypophyseal-gonadal axis in hyperthyroid Indian males, (ii) to rule out the modulatory role of adrenal steroids on it and (iii) to determine if the simultaneous rise in oestradiol and luteinising hormone (LH) in hyperthyroid males is due to a positive feedback action of oestradiol on pituitary LH release. Age- and BMI-matched men were divided into two groups, I, euthyroid subjects (n = 17) and II, hyperthyroid patients (n = 12) on the basis of their thyroid hormone levels. Serum levels of thyroid-stimulating hormone, triiodothyronine, thyroxine, LH, follicle-stimulating hormone (FSH), prolactin, E(2), T, P(4), sex hormone binding globulin and dehydroepiandrosterone sulphate (DHEAS) were assayed. Mean levels of T and E(2) were approximately two times higher in group II in comparison with group I. DHEAS levels were similar in both groups ruling out any adrenal involvement. Mean serum LH level was 2.6 folds higher in group II in comparison with group I. Mean serum levels of FSH were higher in group II, it was marginally nonsignificant. On the basis of these and previous observations, we hypothesise that endocrinological dimorphism in human male and female is not rigid; a sustained rise in serum oestradiol probably induces a positive feedback action on pituitary leading to elevated gonadotrophin levels.

FOXO Transcription Factors and their Role in Disorders of the Female Reproductive Tract

All fundamental reproductive events in the human ovary and uterus, including ovulation, implantation and menstruation, are dependent upon profound tissue remodelling, characterized by cyclical waves of cell proliferation, differentiation, recruitment of inflammatory cells, apoptosis, tissue breakdown and regeneration. Although the rise and fall in ovarian hormones, estradiol and progesterone, orchestrate these reproductive events, FOXO transcription factors, an evolutionary conserved subfamily of forkhead transcription factors, have emerged major downstream effector molecules, capable of integrating hormonal cues with a variety of stress, growth factor and cytokine signal transduction pathways. The ability of FOXOs to regulate seemingly opposing cellular responses, ranging from cell cycle arrest and oxidative stress responses to differentiation and apoptosis, renders these transcription factors indispensable for cyclic tissue remodelling in the reproductive tract. Aberrant expression or perturbed activity of FOXO transcription factors are increasingly linked to prevalent reproductive disorders, such as endometriosis, endometrial cancer, primary ovarian insufficiency and pregnancy failure, which in turn highlights their potential as therapeutic targets.

Salivary estradiol, interleukin-6 production, and the relationship to substrate metabolism during exercise in females

Estradiol (E(2)) has been documented to have anti-inflammatory effects on the immune system. Interleukin-6 (IL-6), is classified as a "myokine", and has known metabolic consequences. Thus, the purpose of this study was to determine the effects of menstrual phase and exercise on the interaction of E(2) and IL-6, and the role of IL-6 in substrate metabolism. Ten female subjects completed three separate testing sessions: baseline evaluation, and 1h of treadmill exercise at 65% of peak [Formula: see text] during both the midfollicular (MF) and midluteal (ML) menstrual phases. Saliva was collected prior to, during, and post-exercise for determination of E(2) and IL-6. Expired gases and an additional saliva sample were collected 30min post-exercise. No significant differences were observed in any of the measured variables across menstrual phase. Exercise resulted in an acute rise in estradiol and IL-6; however, E(2) was not related to IL-6 at baseline or in response to exercise. IL-6 remained elevated at the end of exercise and was found to be related to energy expenditure from fat, and to total energy expenditure at 60min, and 30min post-exercise. No relationships were found between the anti-inflammatory estrogen E(2) and the cytokine IL-6. However, relationships were found between IL-6 and indices of substrate metabolism. Based on the data from the current research, IL-6 likely plays a metabolic role in healthy individuals during exercise when released from the muscle as a result of reduced energy availability, acting as a "myokine", in comparison to inflammation-induced IL-6 release.

Fertility Preservation in Women With Breast Cancer

Fertility preservation is an important issue for young women diagnosed with breast cancer. The most well-established options for fertility preservation in cancer patients, embryo and oocyte cryopreservation, have not been traditionally offered to breast cancer patients as estradiol rise during standard stimulation protocols may not be safe for those patients. Potentially safer stimulation protocols using tamoxifen and aromatase inhibitors induce lower levels of estradiol whereas similar results in terms of number of oocyte and embryo obtained to standard protocols. Cryopreservation of immature oocytes and ovarian cortical tissue, both still experimental methods, are also fertility preservation options for breast cancer patients.

Isometric Knee-Extension and Knee-Flexion Torque Production During Early Follicular and Postovulatory Phases in Recreationally Active Women

Acute decreases in strength have been associated with risky biomechanical strategies that might predispose one to injury. Whether acute changes in thigh muscle torque occur across the menstrual cycle remains equivocal. We compared maximal voluntary isometric contraction (MVIC) torque of the knee flexors and extensors between the early follicular (EF) and either the early luteal (EL) or midluteal (ML) phases, which were confirmed by serum hormone concentrations. We expected that MVIC torques would increase from the EF to the EL phase after estradiol peaked and before increased exposure to progesterone. Cohort study. Applied Neuromechanics Research Laboratory. Seventy-one recreationally active women (age range, 18-30 years). The MVICs were measured 1 day during menses and 1 day during the 8 days after ovulation. Participants were grouped by the hormone profile of their luteal test days as EL phase, ML phase, or anovulatory cycle. The MVIC torque of knee flexors and extensors (Nm/kg), estradiol (pg/mL), progesterone (ng/mL), and testosterone (ng/dL). We tested 29 women during their EL phases, 32 during their ML phases, and 10 during anovulatory cycles. Although we observed relatively large individual changes in sex hormone concentrations and MVIC torques across the 2 test sessions, we observed no difference in MVIC torque between test phases (F(1,68) = 1.17, P = .28) or among groups by test phase (F(2,68) = 0.31, P = .74). Thigh MVIC torque did not change from time of menses (when estradiol and progesterone were lowest) to time in the luteal phase after an unopposed estradiol rise or combined estradiol and progesterone rise. However, these findings were limited to MVIC torque production measured at 2 different times, and further research examining these relationships at multiple times and using other measures of neuromuscular function is needed.

The normal menstrual cycle in women

The menstrual cycle in women is characterised by high variability in cycle length (26–35 days), 5-day menses, a fertile phase from 5 days before to the day of ovulation, and low fertility which is dependent on cycle length and age. All women show an FSH rise at the luteal–follicular transition, stimulating a cohort of follicular growth and inhibin B secretion in the early follicular phase. The ovulatory dominant follicle (DF) is selected in the mid-follicular phase, and as this DF grows it increasingly secretes oestradiol and inhibin A for a week before ovulation. Gonadotrophin responsiveness, IGF binding protein expression and degradation, and vascularisation have been identified to be crucial for DF selection and progression. Two-thirds of women show two follicle waves and 1/3 show 3 follicle waves per cycle. Three-wave women have longer cycles, and a later oestradiol rise and LH surge. The corpus luteum secretes progesterone, oestradiol and inhibin A in response to LH pulses, and reaches its peak in terms of size, secretions, and vascularization 6–7 days after ovulation. Luteal regression is passive and independent of the uterus, but can be prevented by hCG, the luteotrophic signal from the trophoblast, from 8 days after conception. Reductions in systemic steroid and protein hormone concentrations may be responsible for the FSH rise characteristic of premenopausal women. The functional layer of the endometrium shows steroid hormone-dependent proliferation, differentiation, and shedding in the absence of the trophoblast. Menstruation is initiated by progesterone responsive decidual cells, and executed by PGE and PGF2α, vasoconstriction and matrix metalloprotease secretion by leukocytes. Ovarian function and also hormone fluctuations during the menstrual cycle are similar to oestrous cycles of cows and mares, justifying research into comparative aspects of menstrual and oestrous cycles in monovulatory species.

Double GnRH-antagonist dose before HCG administration may prevent OHSS in oocyte-donor cycles: a pilot study

This pilot study evaluated the possibility of preventing early ovarian hyperstimulation syndrome (OHSS) by increasing the daily dose of gonadotrophin-releasing hormone (GnRH) antagonist administration (to twice a day) in oocyte-donor cycles stimulated with the antagonist protocol. The study included 72 oocyte donors who underwent ovarian stimulation using the GnRH antagonist protocol and might have had their cycle cancelled because of ovarian hyper-response. All women were donors presenting a rapid rise of oestradiol > or = 3000 pg/ml early in the stimulation period with more than 15 follicles of < or = 15 mm in diameter. By decreasing the rFSH dose to 75 IU a day with an additional daily dose of GnRH antagonist (0.25 mg twice a day), the oestradiol concentrations were lowered or reached a plateau before human chorionic gonadotrophin was given. A marked decrease in oestradiol concentrations and ovarian volume was observed on the day of oocyte retrieval and 3 days post retrieval. None of the donors needed coasting, were cancelled or developed OHSS. In over-responding oocyte donors, by increasing the usual GnRH-antagonist dose to twice a day during ovarian stimulation, the oestradiol rise can be blocked while a minimal follicular stimulation may continue without the risk of developing OHSS or affecting the outcome.

Influence of Nest Deprivation on Behaviour, Hormonal Concentrations and on the Ability to Resume Incubation in Domestic Hens (Gallus domesticus)

In this study, we investigated the influence of the length of nest deprivation period (3 vs. 6 d) on the ability to renest of incubating hens. We focused on the hens' behaviour, particularly on nesting and calls, on their prolactin, luteinizing hormone (LH) and oestradiol concentrations. Nest deprivation induced a drop of prolactin and an increase of LH plasmatic concentrations in hens. These changes in circulating pituitary hormones were followed by changes in ovarian function: the persistent rise of plasmatic oestradiol gave evidence of the resumption of ovarian activity. After nest deprivation, the number of clucks increased significantly and food calls appeared; these results demonstrate that ‘maternal’ calls can be emitted outside the maternal context. Our results suggest that the onset of typical maternal calling is strongly controlled by internal state such as plasmatic hormonal concentrations, independently of social stimulation. None of the 10 hens deprived for 6 d resumed incubation when given the opportunity, whereas, after a 3 d deprivation period, three out of 10 hens renested and two hens incubated sporadically and then gradually abandoned their nests. Long periods of nest deprivation appear to disrupt the habits of sitting and nesting. Before nest reopening, all the hens presented low levels of plasmatic prolactin. Plasma prolactin concentrations of the renesting hens increased after nest boxes were reopened and returned to levels found in incubating hens. We suggest that pituitary prolactin rather than plasmatic prolactin is responsible for the maintenance of incubating potential in hens deprived of their nests.

Early Puberty in Internationally Adopted Girls: Hormonal and Clinical Markers of Puberty in 276 Girls Examined Biannually over Two Years

Background and Aims: Retrospectivestudies have indicated that internationally adopted girls are at high risk of developing precocious puberty. Hypothetically, this could be due to selection bias. The aim of this study was to determine age at reaching pubertal milestones in healthy internationally adopted girls in a prospective, clinical study. Methods: A longitudinal cohort study including 276 randomly recruited internationally adopted girls. At baseline, age ranged from 4 to 13 years. Participants were followed with biannual examinations over a period of 2 years. Examinations included height, weight, Tanner staging, blood sampling and bone age assessment. Age distribution at entering pubertal stages B2–B5 (breast development), PH1–PH5 (pubic hair development) and menarche was estimated by probit analysis. Data were compared to a reference population of Danish-born girls, studied cross-sectionally. Results: Mean age at B2+ was 9.5 years (95% prediction interval 7.1–12.0 years) and mean age at menarche was 12.1 (10.2–14.0) years in adopted girls, which was significantly lower compared to the reference group (p < 0.0003). 16% of adopted girls entered stage B2 before 8 years of age. The puberty-related rise in LH, FSH and estradiol was detected at earlier ages in adopted girls compared to the reference group. Conclusion: Internationally adopted girls have a significantly higher risk of precocious pubertal maturation compared to Danish-born girls.