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Publication
Journal: Archives of Medical Research
April/29/2004
Abstract
BACKGROUND
Our objective was to develop a new animal model for the study of polycystic ovaries by using the non-steroidal aromatase inhibitor, letrozole.
METHODS
Thirty four rats were divided into four groups, including a control group of 10 rats that received vehicle only (1% aqueous solution of carboxmethlycellulose [CMC]) once daily orally (p.o.) and three treatment groups of eight rats each that were administered letrozole at concentrations of 0.1 or 0.5 or 1 mg/kg p.o. dissolved in 1% CMC (2 mL/kg) once daily. The treatment period was 21 days. During this period, vaginal smears were collected daily for estrus cycle determination. On the day subsequent to last letrozole dose administration, rats were killed; uteri and ovaries were then excised and weighed. Serum hormone levels and histologic changes in ovaries were examined.
RESULTS
When compared to control group, ovaries from study groups showed high incidence of subcapsular ovarian cyst and capsular thickening together with incomplete luteinization and decreased number of corpora lutea. Letrozole treatment brought about dose-dependent suppression of uterine weight despite having no significant effect on ovarian weight. Although serum estradiol and progesterone levels were reduced in a dose-dependent manner, testosterone levels were elevated as were levels of luteinizing hormone (LH). Serum follicle-stimulating hormone (FSH) levels were markedly increased at higher doses of letrozole (0.5 and 1.0 mg/kg), contrary to low dose of letrozole (0.1 mg/kg) at which slight decrease was observed.
CONCLUSIONS
Despite the fact that this is not a fully convincing model for the study of polycystic ovaries or of polycystic ovary syndrome (PCOS) as a whole, this animal model in several ways is similar to the human polycystic ovary syndrome.
Publication
Journal: Osteoporosis International
October/29/2006
Abstract
We tested the hypothesis that higher serum osteocalcin and urinary N-telopeptide of type I collagen (NTx) concentrations would be found in women with increasing cycle irregularity or increased follicle stimulating hormone concentrations. We studied 2,375 pre- and early perimenopausal women from the Study of Women's Health Across the Nation (SWAN), aged 42-52 years, who self-identified their race/ethnic origin as African-American (28.3%), Caucasian (49.4%), Japanese (10.5%) or Chinese (11.8%). Outcome measures were serum osteocalcin, a measure of bone formation, and NTx, a measure of bone resorption. The explanatory variables were menopausal status, based on self-reported regularity of menstrual bleeding, and circulating endogenous hormone concentrations including estradiol (E(2)), testosterone (T), sex hormone binding globulin (SHBG) and follicle stimulating hormone (FSH) concentrations. Additionally, we evaluated the association of the bone turnover markers with the Free Androgen Index (FAI) and the Free Estradiol Index (FEI), ratios of total testosterone and estradiol concentrations to SHBG, respectively. Higher FSH concentrations were associated with higher NTx concentrations ( beta=0.003, partial r2=2.1%, p<0.0001), both before and after adjusting for other covariates (total explained variability of 9%). Higher FSH concentrations were also associated with higher osteocalcin concentrations ( beta=-0.216, partial r2=4.1%, p<0.0001, total explained variability of 15.4%). There were no significant associations of the bone turnover markers with other endogenous hormones, following adjustment for covariates. Mean osteocalcin and NTx values were not significantly different in premenopausal women compared to early perimenopausal women. In these pre- and early perimenopausal women, higher FSH concentrations, but not other serum reproductive hormone concentrations, are positively associated with greater bone turnover prior to the last menstrual period.
Publication
Journal: Proceedings of the National Academy of Sciences of the United States of America
June/1/1976
Abstract
Gangliosides inhibit 125I-labeled thyrotropin binding to the thyrotropin receptors on bovine thyroid plasma membranes, on guinea pig retro-orbital tissue plasma membranes, and on human adipocyte membranes. This inhibition by gangliosides is critically altered by the number and location of the sialic acid residues within the ganglioside structure, the efficacy of inhibition having the following order: GD1b greater than GT1 greater than GM1 greater than GM2 = GM3 greater than GD1a. The inhibition results from the interaction of thyrotropin and gangliosides, rather than the interaction of membrane and gangliosides. Fluorescence studies show that the inhibition is associated with a distinct conformational change of the thyrotropin molecule and that the progression from a "noninhibitory conformation" to an "inhibitory conformation" parallels exactly the order of effectiveness in inhibiting 125I-labeled thyrotropin binding. The ganglioside inhibition of 125I-labeled thyrotropin binding appears to be hormonally specific in that it is not affected by albumin, glucagon, insulin, prolactin, follicle-stimulating hormone, growth hormone, or corticotropin. The possibility that a ganglioside or ganglioside-like structure is a component of the thyrotropin receptor is suggested by the finding that gangliosides more complex than N-acetylneuraminylgalactosylglucosylceramide are present in bovine thyroid membranes in much higher quantities than have been previously found in extraneural tissue. The finding that the B component of cholera toxin, which also interacts with gangliosides, has a peptide sequence in common with the beta subunit of thyrotropin, suggests that thyrotropin and cholera toxin may be analogous in their mode of action on the membrane.
Publication
Journal: Molecular and Cellular Endocrinology
March/4/2007
Abstract
A number of signaling proteins have been demonstrated to interact with follicle stimulating hormone (FSH) receptor (FSHR), including APPL1, 14-3-3tau and Akt2. To further define the repertoire of proteins involved in FSH-induced signal transduction, several signaling and adapter proteins were examined for the ability to associate with FSHR. This report shows that, in addition to APPL1, FSHR interacts with FOXO1a and APPL2. Moreover, APPL1 and APPL2 associate with one another via the N-terminus of APPL1, presumably via the Bin-Amphiphysin-Rvs (BAR) domain. The interactions between FSHR and APPL2 and between FSHR and FOXO1a evidently are distinct since FOXO1a does not associate with either APPL1 or with APPL2. Though APPL1 and APPL2 show some similarity in primary sequence, APPL1 associates with Akt2, whereas APPL2 does not. This is the first documented difference in function between APPL1 and APPL2. These results suggest that FSHR, APPL1, APPL2, Akt2 and FOXO1a are organized into distinct scaffolding networks in the cell. Accordingly, the spatial organization of signaling and adapter proteins with FSHR likely facilitates and finely regulates the signal transduction induced by FSH.
Publication
Journal: The Lancet
June/6/2001
Abstract
BACKGROUND
Infertility is a common late effect of chemotherapy and radiotherapy, and has a substantial effect on the quality of life for young survivors of cancer. For men, semen cryopreservation is a simple way of preserving reproductive potential but for women, storage of mature eggs rarely proves successful, and the alternative-immediate in vitro fertilisation with cryopreservation of embryos-is not always appropriate. Reimplantation of cryopreserved ovarian tissue has been shown to restore natural fertility in animals. We applied this technique in a woman who had received sterilising chemotherapy for lymphoma.
METHODS
A 36-year-old woman underwent a right oophorectomy with cryopreservation of ovarian cortical strips before receiving high-dose CBV chemotherapy for a third recurrence of Hodgkin's lymphoma. 19 months later, when serum sex steroid analysis confimed a postmenopausal state, two ovarian cortical strips were thawed and reimplanted-one onto the left ovary and another at the site of the right ovary.
RESULTS
7 months after reimplantation of ovarian cortical strips, the patient reported resolution of hot flashes and, for the first time, oestradiol was detected in the serum. This finding was associated with a decrease in the concentrations of follicle-stimulating hormone and luteinising hormone, and ultrasonography revealed a 10 mm thick endometrium, a poorly visualised left ovary, and a 2 cm diameter follicular structure to the right of the midline. The patient had one menstrual period, but by 9 months after the implantation, her sex steroid concentrations had returned to those seen with ovarian failure.
CONCLUSIONS
Orthotopic reimplantation of frozen/thawed ovarian cortical strips is a well tolerated technique for restoring ovarian function in women treated with sterilising chemotherapy for cancer.
Publication
Journal: Clinical Pharmacology and Therapeutics
December/22/2003
Abstract
OBJECTIVE
The popular herbal remedy St John's wort is an inducer of cytochrome P450 (CYP) 3A enzymes and may reduce the efficacy of oral contraceptives. Therefore we evaluated the effect of St John's wort on the disposition and efficacy of Ortho-Novum 1/35 (Ortho-McNeil Pharmaceutical, Inc, Raritan, NJ), a popular combination oral contraceptive pill containing ethinyl estradiol (INN, ethinylestradiol) and norethindrone (INN, norethisterone).
METHODS
Twelve healthy premenopausal women who were using oral contraception (>3 months) received a combination oral contraceptive pill (Ortho-Novum 1/35) for 3 consecutive 28-day menstrual cycles. During the second and third cycles, the participants received 300 mg St John's wort 3 times a day. The serum concentrations of ethinyl estradiol (day 7), norethindrone (day 7), follicle-stimulating hormone (days 12-16), luteinizing hormone (days 12-16), progesterone (day 21), and intravenous and oral midazolam (days 22 and 23) were determined in serial blood samples. The incidence of breakthrough bleeding was quantified during the first and third cycles.
RESULTS
Concomitant use of St John's wort was associated with a significant (P <.05) increase in the oral clearance of norethindrone (8.2 +/- 2.7 L/h to 9.5 +/- 3.4 L/h, P =.042) and a significant reduction in the half-life of ethinyl estradiol (23.4 +/- 19.5 hours to 12.2 +/- 7.1 hours, P =.023). The oral clearance of midazolam was significantly increased (109.2 +/- 47.9 L/h to 166.7 +/- 81.3 L/h, P =.007) during St John's wort administration, but the systemic clearance of midazolam was unchanged (37.7 +/- 11.3 L/h to 39.0 +/- 10.3 L/h, P =.567). Serum concentrations of follicle-stimulating hormone, luteinizing hormone, and progesterone were not significantly affected by St John's wort dosing (P>>.05). Breakthrough bleeding occurred in 2 of 12 women in the control phase compared with 7 of 12 women in the St John's wort phase. The oral clearance of midazolam after St John's wort dosing was greater in women who had breakthrough bleeding (215.9 +/- 66.5 L/h) than in those who did not (97.5 +/- 37.2 L/h) (P =.005).
CONCLUSIONS
St John's wort causes an induction of ethinyl estradiol-norethindrone metabolism consistent with increased CYP3A activity. Women taking oral contraceptive pills should be counseled to expect breakthrough bleeding and should consider adding a barrier method of contraception when consuming St Johns wort.
Publication
Journal: International Journal of Cancer
October/4/2004
Abstract
Because of large intra-individual variation in hormone levels, few studies have investigated the relation of serum sex hormones to breast cancer (BC) in premenopausal women. We prospectively studied this relation, adjusting for timing of blood sampling within menstrual cycle. Premenopausal women (5,963), recruited to the Hormones and Diet in the Etiology of Breast Tumors (ORDET) cohort study, provided a blood sample in the 20-24th day of their menstrual cycle. After 5.2 years of follow-up, 65 histologically confirmed BC cases were identified and matched individually to 4 randomly selected controls. Sera, stored at -80 degrees C, were assayed blindly for dehydroepiandrosterone sulfate, total and free testosterone (FT), androstenedione, androstanediol-glucoronide, progesterone, 17-OH-progesterone, sex hormone-binding globulin, follicle-stimulating hormone (FSH) and luteinizing hormone (LH). Fifty-five cases had information for multivariate analyses. Compared to controls, BC cases had shorter cycles and intervals between blood sampling and bleeding, and lower LH and FSH. FT was significantly associated with BC risk: relative risk (RR; adjusted for age, body mass index and ovarian cycle variables) of highest vs. lowest tertile was 2.85 [95% confidence interval (CI) = 1.11-7.33, p for trend = 0.030]. Progesterone was inversely associated with adjusted RR for highest vs. lowest tertile of 0.40 (95% CI = 0.15-1.08, p for trend = 0.077), significantly so in women with regular menses, where adjusted RR was 0.12 (95% CI = 0.03-0.52, p for trend = 0.005). These findings support the hypothesis that ovarian hyperandrogenism associated with luteal insufficiency increases the risk of BC in premenopausal women.
Publication
Journal: Osteoporosis International
March/19/2003
Abstract
We evaluated bone mineral density (BMD), hormone concentrations and menstrual cycle status to test the hypothesis that greater variations in reproductive hormones and menstrual bleeding patterns in mid-aged women might engender an environment permissive for less bone. We studied 2336 women, aged 42-52 years, from the Study of Women's Health Across the Nation (SWAN) who self-identified as African-American (28.2%), Caucasian (49.9%), Japanese (10.5%) or Chinese (11.4%). Outcome measures were lumbar spine, femoral neck and total hip BMD by dual-energy X-ray densitometry (DXA). Explanatory variables were estradiol, testosterone, sex hormone binding globulin (SHBG) and follicle stimulating hormone (FSH) from serum collected in the early follicular phase of the menstrual cycle or menstrual status [premenopausal (menses in the 3 months prior to study entry without change in regularity) or early perimenopause (menstrual bleeding in the 3 months prior to study entry but some change in the regularity of cycles)]. Total testosterone and estradiol concentrations were indexed to SHBG for the Free Androgen Index (FAI) and the Free Estradiol Index (FEI). Serum logFSH concentrations were inversely correlated with BMD (r = -10 for lumbar spine [95% confidence interval (CI): -0.13, -0.06] and r = -0.08 for femoral neck (95% CI: -0.11, -0.05). Lumbar spine BMD values were approximately 0.5% lower for each successive FSH quartile. There were no significant associations of BMD with serum estradiol, total testosterone, FEI or FAI, respectively, after adjusting for covariates. BMD tended to be lower (p values = 0.009 to 0.06, depending upon the skeletal site) in women classified as perimenopausal versus premenopausal, after adjusting for covariates. Serum FSH but not serum estradiol, testosterone or SHBG were significantly associated with BMD in a multiethnic population of women classified as pre- versus perimenopausal, supporting the hypothesis that alterations in hormone environment are associated with BMD differences prior to the final menstrual period.
Publication
Journal: Analytical Chemistry
April/11/2007
Abstract
Mass spectrometry is emerging as a versatile analytical tool for profiling glycan and glycopeptide structures. While the interpretation of MS data remains a challenging and difficult task, substantial efforts have been made to develop informatics tools to alleviate MS data interpretation. Here, we present a web-based tool, GlycoPep DB, designed to facilitate compositional assignment for glycopeptides by comparing experimentally measured masses to all calculated glycopeptide masses from a carbohydrate database with N-linked glycans. GlycoPep DB is an advance over current tools to assign N-linked glycans because it uses a concept of "smart searching", where only biologically relevant carbohydrate compositions are searched, when matching carbohydrate compositions with the MS data making glycopeptide compositional assignment more efficient. This is in contrast to currently used tools, where many implausible glycan structures are present in the search output, but fewer biologically relevant glycan motifs are predicted. The utility of GlycoPep DB is illustrated in the analysis of glycopeptides derived from a proteolytic digest of follicle stimulating hormone.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
October/31/2007
Abstract
OBJECTIVE
This study aimed to analyze under which conditions quiescent stem cells derived from human goiters can be propagated to outgrow and whether these cells have retained the capacity to differentiate into thyroid cells.
METHODS
Stem cells were isolated by fluorescence-activated cell sorting as a side population by the Hoechst 33342 efflux technique. Growth pattern of stem cells and cocultures of stem cells with thyrocytes grown as monolayer and in Matrigel was investigated. Expression of stem cell markers, endodermal markers, and thyroid-specific markers was analyzed by RT-PCR. In stem cell-derived thyrocytes, embedded in collagen to form follicles, TSH-dependent (125)iodide uptake was measured.
RESULTS
Stem cells were isolated as a side population from a non-side population fraction that consisted of endodermal marker-positive cells and thyroid cells. Intense growth stimulation of stem cells in coculture with thyrocytes resulted in formation of nonadherent, three-dimensional spheres that consisted of highly proliferating stem cells with their characteristic expression profiles. In response to TSH and serum, sphere-derived progenitor cells differentiated into thyrocytes that expressed paired box gene 8, thyroglobulin, sodium iodide symporter, thyroid-stimulating hormone receptor, and thyroperoxidase mRNA and showed TSH-dependent (125)iodide uptake.
CONCLUSIONS
Quiescent stem cells derived from goiters can be propagated to form spheres that consist of highly proliferating stem cells that are able to differentiate TSH dependently into thyroid cells. Compared with thyrocytes, stem cells display a much higher proliferation rate on acute growth stimulation, which may suggest a putative role of the offspring of stem cells in the chronic growth factor-stimulated nodular transformation of the thyroid.
Publication
Journal: Endocrinology
February/17/1997
Abstract
The Ob gene product, leptin, is secreted by adipocytes and is required for fertility in the mouse. Leptin-deficient mice are obese and infertile, symptoms reminiscent of polycystic ovary syndrome (PCOS). Prior studies have shown that serum leptin levels are elevated in a significant sub-population of anovulatory women with PCOS, suggesting that elevated leptin levels may adversely affect ovarian function. Since leptin receptor mRNA has been detected in the ovary, this study was designed to test the hypothesis that leptin may impair granulosa cell (GC) estradiol-17 beta (E2) production by a direct mechanism. GC were isolated from the ovaries of 26-day-old Sprague-Dawley rats, and were cultured (60,000 GC/well) in 96-well plates in the presence and absence of ovine FSH (0.001-100 ng/ml) and androstenedione (0.1 microM), with and without recombinant murine leptin (0.1-100 ng/ml) for 48 h. Leptin alone had no effect on E2 production. FSH caused a dose-related increase in E2 production by GC (ED50 = 1.9 +/- 0.4 ng/ml). Addition of leptin did not alter FSH-stimulated B2 levels. Concomitant treatment with FSH and IGF-I (30 ng/ml) augmented maximal FSH-dependent E2 production five-fold. Leptin caused a dose-dependent (IC50 = 2.7 +/- 0.6 ng/ml) inhibition (30-50%) of the IGF-I increase in FSH-stimulated E2 production. The inhibitory effect of leptin was specific for E2 production since there was no effect on basal, FSH-, or FSH+ IGF-I-dependent progesterone levels. The results of this study demonstrate that leptin can directly impair the IGF-I-mediated augmentation of FSH-stimulated E2 synthesis by GC. These data raise the possibility that high leptin levels may contribute to infertility in some women with PCOS by counteracting the sensitizing effects of IGF-I in dominant follicles.
Publication
Journal: Endocrinology
November/5/1974
Publication
Journal: Journal of Clinical Investigation
November/11/1998
Abstract
A single natural loss of function mutation of the follicle stimulating hormone receptor (FSHR) has been described to date. Present in the Finnish population it markedly impairs receptor function, blocking follicle development at the primary stage and presenting as primary amenorrhea with atrophic ovaries. When Western European women with this phenotype were examined for FSHR mutations the result was negative, suggesting that other etiologies corresponding to this clinical pattern are markedly more frequent. We now describe a novel phenotype related to mutations provoking a partial loss of function of the FSHR. A woman with secondary amenorrhea had very high plasma gonadotropin concentrations (especially FSH), contrasting with normal sized ovaries and antral follicles up to 5 mm at ultrasonography. Histological and immunohistochemical examination of the ovaries showed normal follicular development up to the small antral stage and a disruption at further stages. The patient was found to carry compound heterozygotic mutations of the FSHR gene: Ile160Thr and Arg573Cys substitutions located, respectively, in the extracellular domain and in the third intracellular loop of the receptor. The mutated receptors, when expressed in COS-7 cells, showed partial functional impairment, consistent with the clinical and histological observations: the first mutation impaired cell surface expression and the second altered signal transduction of the receptor. This observation suggests that a limited FSH effect is sufficient to promote follicular growth up to the small antral stage. Further development necessitates strong FSH stimulation. The contrast between very high FSH levels and normal sized ovaries with antral follicles may thus be characteristic of such patients.
Publication
Journal: Human Reproduction
September/11/2011
Abstract
BACKGROUND
The vitamin D receptor (VDR) is expressed in human spermatozoa, and VDR-knockout mice and vitamin D (VD) deficiency in rodents results in impaired fertility, low sperm counts and a low number of motile spermatozoa. We investigated the role of activated VD (1,25(OH)(2)D(3)) in human spermatozoa and whether VD serum levels are associated with semen quality.
METHODS
Cross-sectional association study of semen quality and VD serum level in 300 men from the general population, and in vitro studies on spermatozoa from 40 men to investigate the effects of VD on intracellular calcium, sperm motility and acrosome reaction. All men delivered samples for routine semen analysis and blood for measurements of follicle stimulating hormone, Inhibin B, 25-hydroxy-VD, albumin, alkaline phosphatase, calcium and parathyroid hormone (PTH).
RESULTS
In the association study, 44% were VD insufficient (<50 nM), and VD was inversely correlated with PTH (P < 0.0005). VD serum levels correlated positively with sperm motility and progressive motility (P < 0.05), and men with VD deficiency (<25 nM) had a lower proportion of motile (P = 0.027), progressive motile (P = 0.035) and morphologically normal spermatozoa (P = 0.044) compared with men with high VD levels (>75 nM). 1,25(OH)(2)D(3) increased intracellular calcium concentration in human spermatozoa through VDR-mediated calcium release from an intracellular calcium storage, increased sperm motility and induced the acrosome reaction in vitro.
CONCLUSIONS
1,25(OH)(2)D(3) increased intracellular calcium concentration, sperm motility and induced the acrosome reaction in mature spermatozoa, and VD serum levels were positively associated with sperm motility, suggesting a role for VD in human sperm function.
Publication
Journal: Experimental Biology and Medicine
May/25/2005
Abstract
Given the close relationship among neuroendocrine systems, it is likely that there may be common signals that coordinate the acquisition of adult reproductive function with other homeostatic processes. In this review, we focus on central nervous system insulin-like growth factor-1 (IGF-1) as a signal controlling reproductive function, with possible links to somatic growth, particularly during puberty. In vertebrates, the appropriate neurosecretion of the decapeptide gonadotropin-releasing hormone (GnRH) plays a critical role in the progression of puberty. Gonadotropin-releasing hormone is released in pulses from neuroterminals in the median eminence (ME), and each GnRH pulse triggers the production of the gonadotropins, luteinizing hormone (LH) and follicle-stimulating hormone (FSH). These pituitary hormones in turn stimulate the synthesis and release of sex steroids by the gonads. Any factor that affects GnRH or gonadotropin pulsatility is important for puberty and reproductive function and, among these factors, the neurotrophic factor IGF-1 is a strong candidate. Although IGF-1 is most commonly studied as the tertiary peripheral hormone in the somatotropic axis via its synthesis in the liver, IGF-1 is also synthesized in the brain, within neurons and glia. In neuroendocrine brain regions, central IGF-1 plays roles in the regulation of neuroendocrine functions, including direct actions on GnRH neurons. Moreover, GnRH neurons themselves co-express IGF-1 and the IGF-1 receptor, and this expression is developmentally regulated. Here, we examine the role of IGF-1 acting in the hypothalamus as a critical link between reproductive and other neuroendocrine functions.
Publication
Journal: Biology of Reproduction
September/20/2005
Abstract
Gonadotropins, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) play critical roles in vertebrate reproduction. In the present study, we cloned and characterized zebrafish FSHbeta (fshb), LHbeta (lhb), and GTHalpha (cga) subunits. Compared with the molecules of other teleosts, the cysteine residues and potential glycosylation sites are fully conserved in zebrafish Lhb and Cga but not in Fshb, whose cysteines exhibit unique distribution. Interestingly, in addition to the pituitary, fshbeta, lhbeta, and cga were also expressed in some extrapituitary tissues, particularly the gonads and brain. In situ hybridization showed that zebrafish fshbeta and lhbeta were expressed in two distinct populations of gonadotrophs in the pituitary. Real-time reverse transcription-polymerase chain reaction (RT-PCR) analysis revealed that all the three subunits increased expression before ovulation (0100-0400) when the germinal vesicles in the full-grown follicles were migrating toward the periphery, but the levels dropped at 0700, when ovulation occurred. Recombinant zebrafish FSH (zfFSH) and LH (zfLH) were produced in the Chinese hamster ovary (CHO) cells and their effects on the cognate receptors (zebrafish Fshr and Lhr) tested. Interestingly, zfFSH specifically activated zebrafish Fshr expressed together with a cAMP-responsive reporter gene in the CHO cells, whereas zfLH could stimulate both Fshr and Lhr. In conclusion, the present study systematically investigated gonadotropins in the zebrafish in terms of their structure, spatial-temporal expression patterns, and receptor specificity. These results, together with the availability of recombinant zfFSH and zfLH, provide a solid foundation for further studies on the physiological relevance of FSH and LH in the zebrafish, one of the top biological models in vertebrates.
Publication
Journal: Journal of Urology
February/3/2009
Abstract
OBJECTIVE
We explored the efficacy of selenium and/or or N-acetyl-cysteine for improving semen parameters in infertile men, and the associations among semen quality and the concentrations of selenium and N-acetyl-cysteine in seminal plasma.
METHODS
The study included 468 infertile men with idiopathic oligo-asthenoteratospermia who were randomized to receive 200 microg selenium orally daily (selenium group of 116), 600 mg N-acetyl-cysteine orally daily (N-acetyl-cysteine group of 118), 200 microg selenium plus 600 mg N-acetyl-cysteine orally daily (selenium plus N-acetyl-cysteine group of 116) or similar regimen of placebo (control group of 118) for 26 weeks, followed by a 30-week treatment-free period. These patients provided blood samples for the measurement of serum testosterone, estradiol, follicle-stimulating hormone, luteinizing hormone, prolactin, inhibin B, selenium and N-acetyl-cysteine. Semen samples were also obtained for routine semen analysis, and the measurement of seminal plasma selenium and N-acetyl-cysteine.
RESULTS
In response to selenium and N-acetyl-cysteine treatment serum follicle-stimulating hormone decreased but serum testosterone and inhibin B increased. All semen parameters significantly improved with selenium and N-acetyl-cysteine treatment. Administering selenium plus N-acetyl-cysteine resulted in additive beneficial effects. A significant positive correlation existed between the seminal plasma concentrations of selenium and N-acetyl-cysteine, and semen parameters. A strong correlation was observed between the sum of the selenium and N-acetyl-cysteine concentrations, and mean sperm concentration (r = 0.67, p = 0.01), sperm motility (r = 0.64, p = 0.01) and percent normal morphology (r = 0.66, p = 0.01).
CONCLUSIONS
These results indicate that supplemental selenium and N-acetyl-cysteine improve semen quality. We advocate their use for male infertility treatment.
Publication
Journal: Journal of Biological Chemistry
November/23/2000
Abstract
AP1 transcription factors control rapid responses of mammalian cells to stimuli that impact proliferation, differentiation, and transformation. To determine which AP1 factors are present in and regulated by hormones in ovarian cells during specific stages of proliferation and differentiation, we used both in vitro and in vivo models, Western blotting, immunohistochemistry, DNA binding assays, and transfections of AP1 promoter-reporter constructs. The expression patterns of Jun and Fos family members in response to hormones (follicle-stimulating hormone (FSH), luteinizing hormone (LH), and cAMP) were distinct. JunB, c-Jun, c-Fos, and Fra2 were rapidly but transiently induced by FSH in immature granulosa cells. JunD and Fra2 were induced by LH and maintained as granulosa cells terminally differentiated into luteal cells. Forskolin and phorbol myristate acetate acted synergistically to enhance transcription of an AP1(-73COL)-luciferase construct. JunD appears to be one mediator of this effect, since JunD was a major component of the AP1-DNA binding complex in granulosa cells, and menin, a selective inhibitor of JunD, blocked transcription of -73COL-luciferase. Thus, FSH and LH via cAMP induce specific AP1 factors, the AP1 expression patterns are distinct, and that of JunD and Fra2 correlates with the transition of proliferating granulosa cells to terminally differentiated, non-dividing luteal cells.
Publication
Journal: Obesity Reviews
May/11/2011
Abstract
Leptin is a pleiotropic cytokine-like hormone that is involved in the regulation of energy intake and expenditure, neuroendocrine function, immunity and lipid and glucose metabolism. The few humans with genetically based leptin deficiency provide a unique model to assess those effects. We have identified five Turkish patients (one male and two female adults; one boy and one girl) with congenital leptin deficiency due to a missense mutation in the leptin gene. Four of these patients were treated with physiological doses of recombinant methionyl human leptin. Body composition, brain structure and function, behaviour, immunity and endocrine and metabolic parameters were evaluated before and during treatment. Our results showed that leptin has peripheral, hypothalamic and extra-hypothalamic effects. Within the endocrine system, leptin regulates the circadian rhythms of cortisol, thyroid-stimulating hormone, luteinizing hormone and follicle-stimulating hormone. In the brain, leptin controls energy balance and body weight, and plays a role on neurogenesis and brain function. Leptin is a key element of the adiposinsular axis, enhances immune response, and regulates inflammation, coagulation, fibrinolysis and platelet aggregation. Our 10-year experience in treating these unique patients provided valuable data on the peripheral and central effects of leptin. Those results can be taken into account for the development of leptin-based therapies for other diseases.
Publication
Journal: Journal of Neurotrauma
May/13/2012
Abstract
Experimental traumatic brain injury (TBI) studies report the neuroprotective effects of female sex steroids on multiple mechanisms of injury, with the clinical assumption that women have hormonally mediated neuroprotection because of the endogenous presence of these hormones. Other literature indicates that testosterone may exacerbate injury. Further, stress hormone abnormalities that accompany critical illness may both amplify or blunt sex steroid levels. To better understand the role of sex steroid exposure in mediating TBI, we 1) characterized temporal profiles of serum gonadal and stress hormones in a population with severe TBI during the acute phases of their injury; and 2) used a biological systems approach to evaluate these hormones as biomarkers predicting global outcome. The study population was 117 adults (28 women; 89 men) with severe TBI. Serum samples (n=536) were collected for 7 days post-TBI for cortisol, progesterone, testosterone, estradiol, luteinizing hormone (LH), and follicle-stimulating hormone (FSH). Hormone data were linked with clinical data, including acute care mortality and Glasgow Outcome Scale (GOS) scores at 6 months. Hormone levels after TBI were compared to those in healthy controls (n=14). Group based trajectory analysis (TRAJ) was used to develop temporal hormone profiles that delineate distinct subpopulations in the cohort. Structural equations models were used to determine inter-relationships between hormones and outcomes within a multivariate model. Compared to controls, acute serum hormone levels were significantly altered after severe TBI. Changes in the post-TBI adrenal response and peripheral aromatization influenced hormone TRAJ profiles and contributed to the abnormalities, including increased estradiol in men and increased testosterone in women. In addition to older age and greater injury severity, increased estradiol and testosterone levels over time were associated with increased mortality and worse global outcome for both men and women. These findings represent a paradigm shift when thinking about the role of sex steroids in neuroprotection clinically after TBI.
Publication
Journal: Osteoporosis International
October/5/2000
Abstract
Bone loss before and around the time of menopause is not well characterized by longitudinal studies. We measured bone mineral density at various skeletal sites--total body, femoral neck, trochanter, anteroposterior (AP) and lateral spine, and forearm--with dual-energy X-ray absorptiometry in a large prospective cohort of 272 untreated pre- and perimenopausal women aged 31-59 years, at 1 year intervals for 3 years. Sex steroids and the following markers of bone remodeling were measured: serum osteocalcin (OC), procollagen I carboxyterminal extension peptide, bone alkaline phosphatase (BAP) and urinary crosslinks (CTX and NTX). Seventy-six women were classified as perimenopausal and 196 as premenopausal. Over the 3 years, premenopausal women had no significant bone loss at any site and a small but significant increase in bone mineral density at the trochanter, total hip, AP spine and radius. Perimenopausal women significantly lost bone from cancellous and cortical sites, i.e., the femoral neck, trochanter and lumbar spine. In perimenopausal women with increased follicle stimulating hormone, the rate of bone loss at the femoral neck correlated negatively with OC and BAP. In perimenopausal women, serum estradiol levels decreased during the 3 years of follow-up and bone loss from the trochanter and the AP spine was correlated with serum estradiol after 3 years. In conclusion, among premenopausal women there is no bone loss. In contrast, there is a rapid and diffuse bone loss in perimenopausal women, related to decreased estrogen secretion. Bone markers may be useful to identify these women losing bone.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
September/23/1991
Abstract
The recent availability of both cordocentesis, a low risk and effective technique for fetal blood sampling, and ultrasensitive/highly specific two-site immunofluorometric assays (IFMA) for pituitary and chorionic glycoprotein hormone (I-LH, I-FSH, and I-CG) measurement prompted us to study the maturation of hypothalamic-pituitary-gonadal function in 114 normal human fetuses (49 females and 65 males) from 17-40 weeks gestation. The subjects were selected from 216 consecutive cordocenteses carried out for rapid karyotyping and diagnosis of fetal infection or hematological disorders. In addition, FSH bioactivity (B-FSH) was measured by rat Sertoli cell aromatase induction assay, glycoprotein hormone alpha-subunit (alpha-SU) by RIA, and circulating free testosterone (fT) by direct analog technique. No significant cross-reactions were recorded in the different measurement methods. In particular, alpha-SU did not interfere in any IFMA, and CG cross-reactivity in LH IFMA was 0.5%. Circulating I-LH, I-FSH, and B-FSH levels at 17-24 weeks gestation were significantly higher in female than in male fetuses (I-LH, 48 +/- 4 vs. 6.3 +/- 0.7 U/L; I-FSH, 35 +/- 2 vs. 0.7 +/- 0.1 U/L; B-FSH, 131 +/- 17 vs. 43.4 +/- 5.4 U/L). During the last weeks of gestation, a significant decrease in I-LH and I-FSH levels was seen in both female and male fetuses (I-LH, 0.24 +/- 0.05 and 1.0 +/- 0.3 U/L; I-FSH, 0.45 +/- 0.1 and 0.5 +/- 0.1 U/L), while serum B-FSH remained elevated, but the previously recorded difference between sexes disappeared (54.3 +/- 7.2 and 58.7 +/- 7.3 U/L). Circulating I-CG and alpha-SU levels at midgestation were elevated in both female and male fetuses (I-CG, 117 +/- 29 and 191 +/- 44 U/L; alpha-SU, 143 +/- 16 and 105 +/- 9 micrograms/L, respectively) and decreased thereafter (I-CG, 42 +/- 9 and 26 +/- 6 U/L; alpha-SU, 60 +/- 15 and 37 +/- 6 micrograms/L). Serum fT levels at midgestation were significantly lower in females than in males (4.3 +/- 0.9 vs. 10.0 +/- 0.8 pmol/L) and increased until term, when the difference between sexes disappeared (16.2 +/- 1.8 vs. 17.6 +/- 1.6 pmol/L).(ABSTRACT TRUNCATED AT 400 WORDS)
Publication
Journal: Occupational and Environmental Medicine
October/24/2002
Abstract
OBJECTIVE
To evaluate effects of exposure to bisphenol A diglycidyl ether (BADGE) on urinary excretion of bisphenol A, and plasma gonadotrophic hormones and testosterone in male epoxy resin sprayers.
METHODS
Cross sectional study of 42 workers whose job was to spray epoxy resin hardening agents including BADGE and mixed organic solvents, and 42 matched control workers without BADGE use in the same machine plants.
RESULTS
Concentrations of urinary bisphenol A were higher in the epoxy resin sprayers (median 1.06 micro mol/mol creatinine) compared with the controls (median 0.52 micro mol/mol creatinine). Urinary metabolite concentrations of organic solvents used were all higher in the epoxy resin workers compared with the controls. Endocrinological examination showed different concentrations of follicle stimulating hormone (FSH) between the epoxy sprayers (median 5.3 mIU/ml) and the controls (median 7.6 mIU/ml). FSH showed a mild correlation with urinary bisphenol A, but not with the metabolites of organic solvents. Luteinising hormone and free testosterone concentrations did not differ between the two groups.
CONCLUSIONS
BADGE may generate bisphenol A endogenously. Results suggest that bisphenol A may disrupt secretion of gonadotrophic hormones in men. The clinical significance of endocrine disrupting effects by bisphenol A should be further investigated in male workers exposed to bisphenol A.
Publication
Journal: Sleep
January/8/2009
Abstract
OBJECTIVE
To relate reproductive hormones (and the preceding 7-year rates of their change) to objectively and subjectively assessed sleep measures, independent of age, vasomotor symptom frequency, depressive symptoms, and body size.
METHODS
A cross-sectional sleep substudy nested in the Study of Women's Health Across the Nation (SWAN), a longitudinal study of the menopausal transition.
METHODS
Community-based.
METHODS
365 Caucasian, African American, and Chinese women.
RESULTS
Sleep duration, continuity, and architecture were measured during two nights of in-home polysomnography (PSG) studies. Participants completed the Pittsburgh Sleep Quality Index (PSQI) for sleep quality, sleep diaries for medication, vasomotor symptoms, lifestyle information and questionnaires for depressive symptoms. Blood collected annually in the years prior to sleep study was assayed for follicle stimulating hormone (FSH), estradiol (E2), and total testosterone (T). More rapid rate of FSH change was significantly associated with higher delta sleep percent, longer total sleep time (TST), but less favorable self-reported sleep quality (PSQI). Baseline E2 was modestly and negatively associated with sleep quality. Women in the lowest total testosterone quartile at baseline had more wake time after sleep onset (WASO) than women in the highest quartile. Lower E2/T ratio, an index reflecting the increasing androgenic environment with the menopause transition, was associated with less WASO.
CONCLUSIONS
More rapid rate of FSH change was associated with longer sleep duration but poor sleep quality. Women with higher T or who were closer to the completion of the transition process (as indexed by a lower E2/T) had less sleep discontinuity (less WASO).
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