Recovery of upland acid grasslands after successful Pteridium aquilinum control: Long-term effectiveness of cutting, repeated herbicide treatment and bruising.

There is a clear need for the development of management strategies to control dominant, perennial weeds and restore semi-natural communities and an important part of this is to know how long control treatments take to be effective and how long they last after treatments stop. Here, we report the results from a 17-year long experiment where we compared the effects of five control treatments on dense Pteridium aquilinum (L. Kuhn) relative to an untreated experimental-control in Derbyshire, UK. The experiment was run in two phases. In Phase 1 (2005-2012) we controlled the P. aquilinum by cutting and bruising, both twice and thrice annually, and a herbicide treatment (asulam in year 1, followed by annual spot-re-treatment of all emergent fronds). In Phase 2 (2012-2021) all treatments were stopped, and the vegetation was allowed to develop naturally. Between 2005 and 2021 we monitored P. aquilinum performance annually and full plant species composition at intervals. Here, we concentrate on analysing the Phase 2 data where we used regression approaches to model individual species responses through time and unconstrained ordination to compare treatment effects on the entire species composition over both Phases. Remote sensing was also used to assess edge invasion in 2018. At the end of Phase 1, a good reduction of P. aquilinum and restoration of acid-grassland was achieved for the asulam and cutting treatments, but not for bruising. In Phase 2, P. aquilinum increased through time in all treated plots but the asulam and cutting ones maintained a much lower P. aquilinum performance for nine years on all measures assessed. There was a reduction in species richness and richness fluctuations, especially in graminoid species. However, multivariate analysis showed that the asulam and cutting treatments were stationed some distance from the untreated and bruising treatments with no apparent sign of reversions suggesting an Alternative Stable State had been created, at least over this nine-year period. P. aquilinum reinvasion was mainly from plot edges. The use of repeated P. aquilinum control treatments, either through an initial asulam spray with annual follow-up spot-spraying or cutting twice or thrice annually for eight years gave good P. aquilinum control and helped restore an acid-grassland community. Edge reinvasion was detected, and it is recommended that either whole-patch control be implemented or treatments should be continued around patch edges.

Change to ecosystem properties through changing the dominant species: Impact of Pteridium aquilinum-control and heathland restoration treatments on selected soil properties.

It is well known that soils are influenced by the plant species that grow in them. Here we consider the effects of management-induced changes to plant communities and their soils during restoration within a 20-year manipulative experiment where the aim was to change a late-successional community dominated by the weed, Pteridium aquilinum, to an earlier-successional grass-heath one. The ecological restoration treatments altered the above- and below-ground components of the community substantially. Untreated plots maintained a dense Pteridium cover with little understory vegetation, cutting treatments produce significant reductions of Pteridium, whereas herbicide (asulam) produced significant immediate reductions in Pteridium but regressed towards the untreated plots within 10 years. Thereafter, all asulam-treated plots were re-treated in year 11, and then were spot-sprayed annually. Both cutting and asulam treatments reduced frond density to almost zero and resulted in a grass-heath vegetation. There was also a massive change in biomass distribution, untreated plots had a large above-ground biomass/necromass that was much reduced where Pteridium was controlled. Below-ground in treated plots, there was a replacement of the substantive Pteridium rhizome mass with a much greater root mass of other species. The combined effects of Pteridium-control and restoration treatment, reduced soil total C and N as and available P concentrations, but increased soil pH and available N. Soil biological activity was also affected with a reduction in soil N mineralization rate, but an increased soil-root respiration. Multivariate analysis showed a clear trend along a pH/organic matter gradient, with movement along it correlated to management intensity from the untreated plots with low pH/high organic matter and treated plots with to a higher pH/lower organic matter in the sequence asulam treatment, cut once per year to cut twice per year. The role that these changed soil conditions might have in restricting Pteridium recovery are discussed.

The role of Pteridium arachnoideum(Kaulf) on the seed bank of the endangered Brazilian Cerrado.

The native bracken (Pteridium arachnoideum) often occurs in mono-specific stands in the Brazilian Cerrado, and this dominance can impact on both the above-ground vegetation and soil seed bank. This study investigated how invasion by this species over a 20-year period changed the seed bank and the relationship between the seed bank and litter mass. We extracted soil samples from three replicated invaded and uninvaded sites, and followed seedling emergence for six months. We collected the above-ground biomass and litter of P. arachnoideum in ten 1m2 plots from three invaded sites. There was no difference between invaded and uninvaded areas in seed bank richness, diversity or overall abundance. The most abundant family was the Melastomataceae, followed by the Poaceae. The Melastomataceae was more abundant in uninvaded sites, but the most common species of this family (Tibouchinastenocarpa) was not affected. The grasses were more common in invaded sites in the rainy season and were affected by heterogeneity in the litter layer. The seed bank could play a role in the recovery of these invaded areas, but the presence of weeds and invasive grasses could constrain their use as a management strategy.

Use of a priori spectral information in the measurement of x-ray flux with filtered diode arrays.

Filtered x-ray diode (XRD) arrays are often used to measure x-ray spectra vs. time from spectrally continuous x-ray sources such as hohlraums. A priori models of the incident x-ray spectrum enable a more accurate unfolding of the x-ray flux as compared to the standard technique of modifying a thermal Planckian with spectral peaks or dips at the response energy of each filtered XRD channel. A model x-ray spectrum consisting of a thermal Planckian, a Gaussian at higher energy, and (in some cases) a high energy background provides an excellent fit to XRD-array measurements of x-ray emission from laser heated hohlraums. If high-resolution measurements of part of the x-ray emission spectrum are available, that information can be included in the a priori model. In cases where the x-ray emission spectrum is not Planckian, candidate x-ray spectra can be allowed or excluded by fitting them to measured XRD voltages. Examples are presented from the filtered XRD arrays, named Dante, at the National Ignition Facility and the Laboratory for Laser Energetics.

A separate mechanism of gonadotropin recovery after pregnancy termination.

To further elucidate the mechanism of return of pituitary secretory function after gestation, eight women were studied for up to 55 days after pregnancy termination. As long as serum estradiol (E2) and progesterone (P) levels were elevated, serum FSH remained low. Four to 6 days after abortion, serum E2 and P decreased to levels seen in the early follicular phase, and thereafter the initial increase in FSH occurred while serum beta-LH remained undetectable. After the initiation of FSH secretion, the levels fluctuated within the normal follicular phase range, resulting in a steady increase of E2 to a mean preovulatory peak of 257 +/- 37 pg/ml at a mean time of 21 +/- 1.3 days after pregnancy termination. This E2 peak was followed by FSH and LH peaks and subsequent ovulation. In contrast to FSH, serum beta-LH levels increased only after PRL-concentrations diminished to 30 ng/ml or less. This initiation of beta-LH secretion followed the advent of FSH secretion in six of eight patients. Therefore, a temporally separate mechanism of FSH and LH secretion after pregnancy termination is theorized. The theory of FSH occurs soon after the E2 and P levels decline while PRL levels are still elevated. However, the secretion of beta-LH increases only after levels have risen from the postabortion decline.

Follicular fluid steroid levels in dysmature and mature follicles from spontaneous and hyperstimulated cycles in normal and anovulatory women.

Follicular maturity and atresia have been defined previously, both hormonally and microscopically, in normal ovulatory women. Ovarian hyperstimulation with clomiphene citrate and human menopausal gonadotropins in normal women is carried out for the purpose of aspirating oocytes from several large follicles for in vitro fertilization. Alterations in follicular fluid (FF) hormone levels occur with hyperstimulation regimens, and some of these large follicles (greater than 18 mm) appear morphologically atretic. We have used the term dysmature to describe those large follicles that have an abnormal oocyte morphological appearance and cannot be fertilized in vitro. Mature follicles have been defined by their size, their oocyte morphological appearance, and their ability to be fertilized in vitro. FF from small (2-3 mm) and large (greater than 18 mm) mature and dysmature follicles were obtained from 10 untreated ovulatory women. Mature and dysmature follicles also were obtained from clomiphene and human menopausal gonadotropin-treated normal (n = 11) and anovulatory (n = 5) women. In untreated cycles, the FF steroid content of the small follicles characterized these follicles to be atretic. FF from dysmature follicles from spontaneous untreated cycles had higher concentrations of dihydrotestosterone, 5 alpha-androstane-3 alpha,17 beta-diol, and 17 beta-estradiol (E2) and lower progesterone (Prog) and Prog to E2 ratios (P less than 0.05). Compared to mature follicles from untreated patients, hyperstimulated mature follicles from ovulatory women had higher FF E2 concentrations and lower Prog to E2 ratios (P less than 0.05). In ovulatory patients, the FF concentrations of testosterone were higher and FF Prog and Prog to E2 ratios were lower (P less than 0.05) in the dysmature than in the mature follicles. Mature follicles from hyperstimulated ovulatory patients and those from hyperstimulated anovulatory patients were similar except for lower FF Prog, higher FF E2, and lower Prog to E2 ratios in the anovulatory group. Dysmature follicles from hyperstimulated anovulatory patients had lower FF androstenedione and dihydrotestosterone, but were generally similar to mature follicles. The percentages of dysmature follicles occurring among all large (greater than 18 mm) follicles that were aspirated were similar in ovulatory (34%) and anovulatory (45%) patients. FF steroid concentrations did not correlate with serum levels of testosterone and E2 at the time of follicle aspiration in any patient group. In conclusion, FF androgen concentrations in hyperstimulated follicles were unrelated to morphological maturity.(ABSTRACT TRUNCATED AT 400 WORDS)

Gonadotropin insufficiency in patients with thalassemia major.

To elucidate whether the cause of sexual maturational arrest in thalassemia major is of hypothalamic or pituitary etiology, three female and two male patients were extensively studied. After the iv administration of 150 micrograms gonadotropin-releasing hormone (GnRH) and 500 micrograms of TRH, all patients demonstrated a minimal LH and no FSH response, with variable PRL and TSH responses. The test was repeated after the patients received 100 micrograms GnRH im daily for 7 days. The LH, FSH, PRL, and TSH responses were similar to those obtained previously. The female patients were then retested twice, after priming with 17 beta-estradiol (2 mg daily for 7 days) and again after treatment with human menopausal gonadotropins. The male patients were treated with hCG and, after testosterone reached normal adult male values, the GnRH-TRH stimulation test was repeated. In both the female and male patients, the pituitary responses remained unchanged. These results demonstrate the presence of primary gonadotropin insufficiency as well as the lack of positive estrogen feedback mechanism in patients with thalassemia major. The site of this abnormality has been demonstrated to be the pituitary gland, since hemosiderosis of the pituitary without hypothalamic involvement has been found at autopsy in one patient.

Identification of proteins in pooled human follicular fluid which suppress follicular response to gonadotropins.

To evaluate the role of nonsteroidal, follicular fluid proteins in folliculogenesis, the 10-55% saturated ammonium sulfate fraction of pooled human follicular fluid was dialyzed against 0.025 M Tris/HCl (pH 7.5) using 10,000 molecular weight exclusion membranes, then passed through agarose immobilized textile dye. Activity was determined by test fraction inhibition of human menopausal gonadotropin (2 U human LH/FSH . day), induced ovarian weight, and serum estradiol increase in hypophysectomized, diethylstilbesterol-treated, 25-day-old female rats. Specific inhibition (89 +/- 6.8% SEM) of ovarian weight increase was found in the material (2 ml) eluted from an Orange A column with KCl (1.5 M, pH 6.8). Inhibitory activity of the Orange A-bound material, which eluted through a standardized Sephadex G-50 column, corresponded to a molecular weight of 13,000-25,000. Isoelectric focusing on a Sephadex G-15 support bed or ampholyte displacement chromatography of Orange A bound material demonstrated inhibitory activity at pH 3.5-4.5 and 6.5-7.0. No demonstrable activity was found in similar fractions eluted through a Concanavalin A-Sepharose 4B column before or after addition of alpha-methyl-D-mannoside (2 M, pH 7). When active fractions were heated (56 C, 1 h) or exposed to trypsin (10 mg/100 ml), activity was lost. When aliquots of the saturated ammonium sulfate-extracted, dialyzed, Orange A-bound eluent were separated by high performance liquid chromatography using gel exclusion columns, activity in the bioassay was recovered in the 13,000-35,000 molecular weight range. Although confirmatory data await further studies, it is tempting to speculate that this protein(s) may be an important inter- and/or intraovarian regulator of follicular response to gonadotropins.

Correlation of human follicular fluid inhibin activity with spontaneous and induced follicle maturation.

We sought to correlate the inhibin activity of individual ovarian follicles (greater than 16 mm in diameter) from untreated (7 patients; 7 follicles), clomiphene-stimulated (150 mg/day; menstrual cycle days 5-9; 9 patients, 14 follicles), and human menopausal gonadotropin (hMG)-stimulated (150 IU/day; menstrual cycle days 3-11; 8 patients; 23 follicles) ovarian cycles and to correlate these results with the follicular fluid (FF) steroid concentration. Follicular aspirates were obtained via laparoscopy from 24 regularly menstruating patients when the diameter of the largest follicle reached 20 mm, as determined by serial ultrasonography. FF concentrations of estradiol, progesterone, testosterone, 17-hydroxyprogesterone, and androstenedione were determined by RIA. Inhibin activity was determined using the inhibition of basal 24-h FSH secretion by dispersed rat anterior pituitary cells. Inhibin values were highest among the follicles aspirated from those patients who received hMG [277 +/- 31 (+/- SE) U/ml] compared to untreated subjects (51 +/- 13 U/ml) or those who received clomiphene (96 +/- 14 U/ml). Estradiol was highest in FF from untreated patients (2295 +/- 1155 ng/ml) compared to levels in patients who received hMG (368 +/- 1.76 micrograms/ml) or clomiphene (1049 +/- 174 ng/ml). FF progesterone values were highest in untreated patients (9.4 +/- 2.59 micrograms/ml) compared to those in hMG-treated (5.04 +/- 1.76 micrograms/ml) and clomiphene-treated patients (7.82 +/- 1.24 ng/ml). FF 17-hydroxyprogesterone values (7.82 +/- 1.24 ng/ml). FF 17-hydroxyprogesterone values were similarly higher in the untreated (1.55 +/- 0.21 micrograms/ml) and clomiphene-treated (2.54 +/- 0.27 micrograms/ml) patients than in the hMG-treated group (0.73 +/- 0.09 micrograms/ml). FF androstenedione (untreated, 50.7 +/- 30 ng/ml; clomiphene-treated, 73.4 +/- 23.4 ng/ml; hMG-treated, 60.2 +/- 19.8 ng/ml) and testosterone (6.66 +/- 2.45, 5.98 +/- 1.46, and 6.39 +/- 2.16 ng/ml, respectively) concentrations in all three patient groups were similar. In untreated patients, there was a highly significant positive correlation between intrafollicular inhibin activity and FF estradiol, testosterone, and androstenedione concentrations and a statistically significant negative correlation between intrafollicular inhibin activity and FF progesterone concentrations. Patients receiving clomiphene therapy demonstrated at least two different response patterns, one with a positive and one a negative correlation between intrafollicular inhibin activity and FF steroid concentrations. The patients receiving hMG therapy had no statistically significant correlation between intrafollicular inhibin

Activity of a human follicular fluid protein(s) in spontaneous and induced ovarian cycles.

Recently, we identified a human follicular fluid protein(s) (FP) which inhibited human menopausal gonadotropin (hMG)-induced rat ovarian weight gain and FSH-induced aromatase. Here, we assessed FP activity from ovulatory patients who were either untreated (n = 7) or received clomiphene (n = 9; 150 mg/day on cycle days 5-9) or hMG (n = 6; 150 IU/day on cycle day 3). Aspirations were performed when one follicular diameter exceeded 20 mm. FP activity was expressed as the percent inhibition of porcine granulosa cell aromatase activity at three concentrations of extracted follicular fluid (range, 1250-10 micrograms; extrapolated to 50 micrograms). Patients receiving hMG or clomiphene had multiple follicles greater than 16 mm in diameter (3.83; 2.66/patient, respectively), while untreated patients had 1 each. FP activity was 14.1 +/- 5.3% (mean +/- SEM) inhibition for untreated, 18.0 +/- 3.4% inhibition for hMG-treated, and 13.7 +/- 5.3% inhibition for clomiphene-treated patients. Follicular fluid estradiol levels from untreated patients (2590 +/- 1221 ng/ml) were greater than estradiol concentrations from hMG-treated (356 +/- 55 ng/ml; P less than 0.01) or clomiphene-treated (1317 +/- 344 ng/ml; P less than 0.05) patients. Progesterone follicular fluid levels were 9.84 +/- 3.3, 5.18 +/- 61, and 11.3 +/- 2.3 micrograms/ml for untreated, hMG-treated, and clomiphene-treated patients, respectively (P less than 0.05). A similar relationship was present with 17-hydroxyprogesterone (untreated, 1.6 +/- 0.2 micrograms/ml; hMG-treated, 0.76 +/- 0.1 micrograms/ml; clomiphene-treated, 2.16 +/- 0.3 micrograms/ml; P less than 0.05). Androstenedione and testosterone follicular fluid levels were similar in all groups (78.9 +/- 23 and 7.09 +/- 2.14 ng/ml, respectively). Untreated patients had a positive correlation between FP and follicular fluid estradiol (r = 0.689; P less than 0.01) and inhibin activity (r = 0.654; P less than 0.05), and a negative correlation between follicular fluid progesterone levels (r = 0.622; P less than 0.05). Patients treated with hMG had a significant negative correlation between FP activity and follicular fluid progesterone levels (r = 0.756; P less than 0.005) and a biphasic correlation with follicular fluid 17-hydroxyprogesterone (r2 = 0.853; P less than 0.0025). Clomiphene-treated patients had biphasic correlations between follicular fluid estradiol and 17-hydroxyprogesterone levels (r2 = 0.853 and P less than 0.0025, and r2 = 0.637 and P less than 0.025, respectively). These findings indicate that the FP activity of the dominant follicle correlates with its state of differentiation, as described by intrafollicular estradiol, progesterone, 17-hydroxyprogesterone levels and inhibin activity. These relationships are in part dependent upon gonadotropin stimulation.

Modelling the luteinizing hormone-releasing hormone pulse generator.

Pituitary hormones are released in pulses as a result of episodic patterns of electrical activity in neuroendocrine neurons. The mechanisms underlying such pulsatility have, however, been difficult to elucidate. For example, the luteinizing hormone-releasing hormone neurons regulating reproductive functioning have a sparse and scattered distribution within the hypothalamus which has made definitive electrophysiological investigation impracticable. Little is known not only of their electrical characteristics, but also of the critical neural components with which they interact to form the so-called "luteinizing hormone-releasing hormone pulse generator". We have used here a neural modelling approach, based on the FitzHugh-Nagumo model of a single neuron, to provide a simple dynamical network model of this neuroendocrine pulse generator. We have found that the minimal components required to generate pulsatile luteinizing hormone secretion arise from combining luteinizing hormone-releasing hormone neurons with reciprocally connected inhibitory interneurons and an external stimulatory input. Local GABA neurons and ascending noradrenergic and/or adrenergic inputs have been used as the biological basis for these respective components. The network displays a wide repertoire of behaviours comparable with experimental observations, including some thought previously to be paradoxical. The capacity of this model network to display complex behavioural features interpretable against experimental evidence suggests that this type of modelling may become a necessary adjunct to empirical studies of pulsatile neuroendocrine systems.

Methods used to improve gamete efficiency.

Male factor infertility accounts for a significant percentage of problems in infertile couples. With clinical utilization of the technologies for selection of good-quality spermatozoa from the ejaculate, our ability to successfully treat the severely affected male factor couple has improved. However, it must be remembered that even with current technologies, fertilization success is reduced in these patients but remains above a 50% level. Other factors that can be used in the future to improve on these statistics are being investigated in regard to the in vitro environment for gametes, that is, the type of culture medium, the methods of coincubation of the sperm and egg, and other methods of enhancement of sperm fertilizing potential. However, methods of sperm preparation will achieve improvement in a percentage of these males treated, and can be used to improve fertilization and pregnancy success. It is important to understand the limitations of the zona-free hamster test, but it is also important to use that test as a screening method for sperm handling. By utilizing the SPA to select out the optimal method of sperm preparation, the fertilization and pregnancy outcome can be improved. Overall, the live-birth rate in male factor infertile couples is lower than non-male-factor couples treated by IVF and GIFT. Until more is known about basic spermatozoal function, and the ability to improve that function in affected males, the live-birth rate should not be expected to change substantially.

Pregnancy complicated by ruptured endometrioma.

Pregnancy complicated by ovarian endometrioma is rare; only four cases have been reported. Although infertility and endometriosis are closely related, endometriosis may be found with pregnancy and, although it has been written that endometriosis will regress with pregnancy, occasionally complications may occur. This report illustrates such a complication with the rupture of an ovarian endometrioma.

Feedback effects of estradiol and progesterone upon gonadotropin and prolactin release.

The relationship between estradiol- and progesterone-mediated gonadotropin release and steroid-induced changes in prolactin levels was investigated in an improved human experimental model. Three women who had undergone bilateral ovariectomy were studied after they had received a subcutaneous implant of one 25-mg estradiol (E2) pellet. Serum E2 levels remained between 60 and 125 pg/ml, and serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH) concentrations were within the normal or slightly elevated range. Serum prolactin (PRL) levels were normal. Each woman received intramuscular injections of gradually increasing doses of estradiol benzoate (E2B) alone and in combination with progesterone (P) in 7 different experiments. An E2B-induced rise in E2 levels comparable to that observed at midcycle elicited a clearly defined LH surge but no change in FSH and PRL. Rising E2 concentrations followed by increasing P levels caused LH and FSH release but no change in PRL. When only P was administered or when serum P levels rose concomitantly with E2 levels, PRL and gonadotropin levels remained unchanged. These data indicate that a surge of E2 similar to that observed at midcycle triggers an acute release of LH only. Moreover, P levels commensurate with those found at mid-cycle facilitate an E2-mediated LH release and induce a concomitant peak in FSH. The lack of a significant increase in PRL levels suggests that different mechanisms are responsible for the pituitary release of PRL and gonadotropins.

Gonadotropin and estradiol levels during ovarian stimulation in women treated with leuprolide acetate.

Levels of FSH, LH, and estradiol (E2) were measured in the serum of 209 gonadotropin-releasing hormone analogue-treated women and in 202 control subjects during the final 5 days of ovarian stimulation in our in vitro fertilization program. Levels of FSH and E2 in serum of gonadotropin-releasing hormone analogue-treated subjects significantly exceeded control values during the sampling period, whereas LH levels were significantly lower. Concentrations of E2 in serum of gonadotropin-releasing hormone analogue-treated and control subjects were similar when corrected for differences in numbers of follicles aspirated at oocyte retrieval (mean of 8.9 and 7.2 follicles per subject, respectively). Pregnancy rates by diagnostic ultrasound were 18 and 11%, respectively, a statistically significant difference.

Effect of suckling on serum prolactin, luteinizing hormone, follicle-stimulating hormone, and estradiol during prolonged lactation.

Eight nursing subjects had serum prolactin (PRL), luteinizing hormone, follicle-stimulating hormone, and estradiol levels studied during the first six months postpartum. Each subject had serum samples obtained just before the initiation of suckling and during the next 120 minutes. Baseline PRL levels were high at ten days postpartum (90.1 ng/mL), then slowly declined but remained elevated at 180 days postpartum (44.3 ng/mL), with the stimulus of suckling being able to double the baseline PRL value throughout the study period. Mean estradiol levels were low at ten days postpartum (7.2 pg/mL), then gradually rose to a mean level of 47.3 pg/mL at 180 days postpartum; however, in four subjects who were amenorrheic during the study period, the mean estradiol levels remained low (4.25 pg/mL), while baseline PRL levels remained high (63.6 ng/mL).

Hyperprolactinemia: comparison of thyrotropic-releasing hormone and tomography.

A group of 95 women with unexplained hyperprolactinemia (over 20 ng/mL) underwent radiologic examination of the sella turcica with hypocycloidal polytomography (N = 58), computed axial tomography (N = 8), or both (N = 29). All patients also underwent a thyrotropin-releasing hormone (TRH) stimulation test, with serum prolactin (PRL) measurement before and 20 and 30 minutes after a 500-micrograms intravenous bolus of TRH. Their PRL responses were compared with those of two control groups, nine normal women in the follicular phase of the menstrual cycle, and 13 women in the first five months of gestation with pregnancy-related hyperprolactinemia. Both control groups exhibited PRL increases with 95% confidence limits at least 200% above baseline levels. In all, 12 patients from the study group also had a normal PRL response (more than a 200% increase) to TRH, and none of these women had tomographic findings consistent with a pituitary tumor. The remaining 83 women all had diminished or absent PRL increases after TRH administration; 46 (55%) of these patients had radiographic evidence of an adenoma, whereas 37 (45%) had no clear signs of a tumor on either polytomography or computed axial tomography. No patient with a baseline PRL level in excess of 60 ng/mL had a normal PRL response to TRH. The results of the study indicate that 1) in patients with PRL between 20 and 60 ng/mL, a normal TRH test can be relied upon to avoid the expense and radiation of tomography (computed axial tomography or polytomography), 2) there is no benefit to be obtained in performing a TRH test in patients with a baseline PRL level over 60 ng/mL, and 3) about 45% of patients with hyperprolactinemia and an abnormal TRH test have a normal computed tomography or polytomography. These patients may have a small adenoma, and thus warrant closer follow-up than patients with a normal TRH test.

Ovarian responses to menopausal gonadotropins in groups of patients with differing basal growth hormone levels.

OBJECTIVE: To investigate the relationship between endogenous serum levels of human growth hormone (hGH) and ovarian response to human menopausal gonadotropins (hMG). DESIGN: Retrospective analysis of patient response to hMG. SETTING: Center for assisted reproductive technology. PATIENTS: Eighty women who had undergone controlled ovarian hyperstimulation with hMG. Basal levels of hGH in sera from 40 of these patients were less than 5.0 microIU/mL (low hGH), values for the remaining 40 were greater than 5.0 microIU/mL (high hGH). Levels of hGH in day 2 sera were analyzed against numbers of oocytes recovered in an additional 182 patients. MAIN OUTCOME MEASURES: Serum estradiol (E2) levels and numbers of oocytes recovered at oocyte pick-up. RESULTS: Average (+/- SE) levels of hGH in sera of high-hGH and low-hGH patients were 10.2 +/- 0.6 and 2.47 +/- 0.3 microIU/mL, respectively (P less than 0.05). Respective peripheral levels of insulin-like growth factor-I were 105.3 +/- 2.9 and 97.2 +/- 2.8 ng/mL. Levels of E2 in serum of high-hGH patients exceeded respective (P less than 0.05) low-hGH values throughout folliculogenesis, and more oocytes were recovered from high-hGH patients (8.1 +/- 0.9 versus 4.7 +/- 0.5 for low-hGH patients; P less than 0.05). Serum progesterone values did not differ. Higher day 2 hGH levels were associated with higher numbers of oocytes recovered after controlled ovarian hyperstimulation. CONCLUSIONS: The present findings indicate that endogenous hGH may augment gonadotropins during follicle recruitment and during multiple folliculogenesis in women. The phase of maximum ovarian sensitivity to hGH/gonadotropin synergism and the nature of synergism remain unclear.

The effect of protein supplementation on single-cell mouse embryos in vitro.

For determination of the effect of protein supplementation on single-cell mouse embryos in vitro, 842 single-cell embryos were cultured initially in protein-free medium for variable periods of time and then transferred to bovine serum albumin (BSA)-supplemented medium. The embryos cultured for 24 hours or longer in protein-free medium demonstrated significantly reduced growth rates. An additional 770 embryos were cultured in BSA-supplemented medium initially and then transferred to human fetal cord serum (HCS)-supplemented medium. Significantly reduced growth rates were observed when transfer from BSA to HCS occurred at 48 hours or earlier, and an increased hatching rate was seen if culture in BSA-supplemented medium continued for up to 57 hours. Another 492 embryos were cultured in HCS-supplemented medium and then transferred to BSA. Significantly reduced growth rates were observed when the transfer occurred at 24 hours or later. HCS was then separated by ultrafiltration (10,000 mol wt cutoff), and 1109 embryos were cultured in the media with BSA, whole HCS, small molecular weight fraction (SMCS), or large molecular weight fraction (LMCS) of HCS or BSA and SMCS. The embryos cultured with SMCS demonstrated a significantly reduced growth rate even if BSA was added in the medium. In summary, it appears that the type and timing of protein supplementation of the culture medium is important to embryo growth. Moreover, it seems that serum contains properties that may even be toxic to embryo survival in vitro.

Growth hormone in serum of women during the menstrual cycle and during controlled ovarian hyperstimulation.

STUDY OBJECTIVE: To investigate the interrelationships between circulating levels of endogenous human growth hormone (hGH), gonadotropins, estradiol (E2), and progesterone (P). DESIGN: Retrospective. SETTING: Assisted reproductive technology center. PATIENTS: Nine normally cycling women from whom blood samples were drawn daily; 18 patients undergoing controlled ovarian hyperstimulation. RESULTS: During the menstrual cycle, average (+/-SE) hGH levels in serum ranged between 7.97 +/- 2.71 microIU/mL on day 11 and 2.11 +/- 0.38 microIU/mL on day 22. Serum hGH levels did not correlate with peripheral levels of follicle-stimulating hormone (FSH), luteinizing hormone, P, or E2 and were related to the serum E2:FSH ratio (adhibited as an index of ovarian response to FSH) on cycle day 10 only. Levels of hGH in sera of patients undergoing controlled ovarian hyperstimulation were near 4 microIU/mL and were directly related to peripheral E2 levels at the time of induction of oocyte maturity. When corrected for differences in follicle number between stimulated patients, changes in serum E2 content were independent of respective hGH levels. CONCLUSION: The findings challenge speculation that endogenous peripheral hGH content might relate to ovarian responsiveness to FSH.