Citations
All
Search in:AllTitleAbstractAuthor name
Publications
(21K+)
Patents
Grants
Pathways
Clinical trials
Publication
Journal: Environmental Health Perspectives
March/24/2008
Abstract
BACKGROUND
Environmental toxicants are allegedly involved in decreasing semen quality in recent decades; however, definitive proof is not yet available. In 1976 an accident exposed residents in Seveso, Italy, to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD).
OBJECTIVE
The purpose of this study was to investigate reproductive hormones and sperm quality in exposed males.
METHODS
We studied 135 males exposed to TCDD at three age groups, infancy/prepuberty (1-9 years), puberty (10-17 years), and adulthood (18-26 years), and 184 healthy male comparisons using 1976 serum TCDD levels and semen quality and reproductive hormones from samples collected 22 years later.
RESULTS
Relative to comparisons, 71 men (mean age at exposure, 6.2 years; median serum TCDD, 210 ppt) at 22-31 years of age showed reductions in sperm concentration (53.6 vs. 72.5 million/mL; p = 0.025); percent progressive motility (33.2% vs. 40.8%; p < 0.001); total motile sperm count (44.2 vs. 77.5 x 10(6); p = 0.018); estradiol (76.2 vs. 95.9 pmol/L; p = 0.001); and an increase in follicle-stimulating hormone (FSH; 3.58 vs. 2.98 IU/L; p = 0.055). Forty-four men (mean age at exposure, 13.2 years; median serum TCDD, 164 ppt) at 32-39 years of age showed increased total sperm count (272 vs. 191.9 x 10(6); p = 0.042), total motile sperm count (105 vs. 64.9 x10(6); p = 0.036), FSH (4.1 vs. 3.2 UI/L; p = 0.038), and reduced estradiol (74.4 vs. 92.9 pmol/L; p < 0.001). No effects were observed in 20 men, 40-47 years of age, who were exposed to TCDD (median, 123 ppt) as adults (mean age at exposure, 21.5 years).
CONCLUSIONS
Exposure to TCDD in infancy reduces sperm concentration and motility, and an opposite effect is seen with exposure during puberty. Exposure in either period leads to permanent reduction of estradiol and increased FSH. These effects are permanent and occur at TCDD concentrations < 68 ppt, which is within one order of magnitude of those in the industrialized world in the 1970s and 1980s and may be responsible at least in part for the reported decrease in sperm quality, especially in younger men.
Publication
Journal: Endocrinology
December/21/2000
Abstract
Targeted disruption of the receptor for glycoprotein hormone, FSH (FSH-R) causes a gene dose-related endocrine and gametogenic abnormality in female mice. The resulting FSH-R knockout (FORKO) mutants have disordered estrous cycles, ovulatory defects, and atrophic uterus. The heterozygous animals that initially show reduced fertility undergo early reproductive senescence and stop breeding altogether. Lack of FSH-R signaling in females causes severe ovarian underdevelopment producing chronic estrogen deficiency. This was accompanied by increases in serum testosterone levels. Ovarian aromatase gene transcription and translation are unaltered in the mutants. Early loss of estrogen in the null mutants leads to obesity and skeletal abnormalities that intensify with age producing (kyphosis), a hunchback appearance. Both these changes also become apparent in older heterozygous mice coincident with early reproductive senescence. The expression of nuclear estrogen receptor(s) alpha and beta genes and the corresponding proteins in the ovary and uterus of FORKO mice appear to be intact. The loss of ovarian estrogen creates an imbalance in A and B forms of the progesterone receptor in the uterus of both heterozygotes and null mutants. Some of the changes we have documented here in FORKO mice are reminiscent of the ovarian dysfunction and other major symptoms that are usually associated with estrogen deficiency. In null mutants, estradiol-17beta administration promptly induced uterine growth and reversed the accumulation of adipose tissue indicating that estrogen receptors are functional. Thus, the phenotypes evident in these genetically altered FSH-R mutants may provide an experimental system to explore the effects of estrogenic compounds on different targets including the ovary in a nonsurgical setting.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
November/24/1997
Abstract
FSH stimulates antral follicles to grow, but its role in earlier stages, if any, is obscure. Our aim was to determine the follicle stage at which the FSH receptor (FSHr) gene is first expressed. We used a PCR-based strategy to analyze single follicles ranging from primordial to multilaminar stages after isolation from human ovaries. Ovarian tissue was obtained from 11 women (age range, 25-33 yr) undergoing elective cesarean section. Tissue was partially disaggregated in medium containing 1% collagenase, and follicles were manually dissected free of stroma. Follicle stages were confirmed microscopically as primordial (nongrowing), primary (1 layer of cuboidal granulosa cells), or having 2 or more layers of granulosa cells. Rectus muscle and stromal tissue were used as negative controls. Messenger ribonucleic acid (mRNA) from each follicle was reverse transcribed, and the resulting cDNA was amplified by nested PCR using primers for FSHr and actin. None of the 9 primordial follicles expressed FSHr mRNA. Thirty-three percent of the primary and 2-layer follicles were positive for FSHr mRNA (4 of 12 and 3 of 9, respectively), as were 100% (n = 4) of the multilaminar follicles. The difference in FSH expression between the growing and primordial follicles was significant. This study shows for the first time that transcription of the FSHr gene begins at the earliest stages of follicular growth and indicates that FSH may have a hitherto unsuspected physiological role in preantral follicle development. In addition, this study demonstrates the practical feasibility of investigating the expression of other genes during human folliculogenesis.
Publication
Journal: Nature Communications
May/8/2016
Abstract
Polycystic ovary syndrome (PCOS) is a common, highly heritable complex disorder of unknown aetiology characterized by hyperandrogenism, chronic anovulation and defects in glucose homeostasis. Increased luteinizing hormone relative to follicle-stimulating hormone secretion, insulin resistance and developmental exposure to androgens are hypothesized to play a causal role in PCOS. Here we map common genetic susceptibility loci in European ancestry women for the National Institutes of Health PCOS phenotype, which confers the highest risk for metabolic morbidities, as well as reproductive hormone levels. Three loci reach genome-wide significance in the case-control meta-analysis, two novel loci mapping to chr 8p23.1 [Corrected] and chr 11p14.1, and a chr 9q22.32 locus previously found in Chinese PCOS. The same chr 11p14.1 SNP, rs11031006, in the region of the follicle-stimulating hormone B polypeptide (FSHB) gene strongly associates with PCOS diagnosis and luteinizing hormone levels. These findings implicate neuroendocrine changes in disease pathogenesis.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
April/12/1967
Publication
Journal: Journal of Clinical Oncology
June/6/2001
Abstract
OBJECTIVE
Most breast cancer survivors experience hot flashes; many use complementary or alternative remedies for these symptoms. We undertook a randomized clinical trial of black cohosh, a widely used herbal remedy for menopausal symptoms, among breast cancer patients.
METHODS
Patients diagnosed with breast cancer who had completed their primary treatment were randomly assigned to black cohosh or placebo, stratified on tamoxifen use. At enrollment, patients completed a questionnaire about demographic factors and menopausal symptoms. Before starting to take the pills and at 30 and 60 days, they completed a 4-day hot flash diary. At the final visit, they completed another menopausal symptom questionnaire. Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels were measured in a subset of patients at the first and final visits.
RESULTS
Of 85 patients (59 on tamoxifen, 26 not on tamoxifen) enrolled in the study, 42 were assigned to treatment and 43 were assigned to placebo; 69 completed all three hot flash diaries. Both treatment and placebo groups reported declines in number and intensity of hot flashes; the differences between the groups were not statistically significant. Both groups also reported improvements in menopausal symptoms that were, for the most part, not significantly different. Changes in blood levels of FSH and LH also did not differ in the two groups.
CONCLUSIONS
Black cohosh was not significantly more efficacious than placebo against most menopausal symptoms, including number and intensity of hot flashes. Our study illustrates the feasibility and value of standard clinical trial methodology in assessing the efficacy and safety of herbal agents.
Publication
Journal: Molecular Endocrinology
October/15/2003
Abstract
FSH is controlled by a variety of positive and negative stimuli, and the unique FSHbeta-subunit is a major target for this regulation. Activin is a key modulator of FSHbeta transcription and hormone secretion. The signal transduction pathway leading to FSH expression was previously unknown. Here, we show that the transcription factors Smad3 and Smad4 mediate activin-stimulated activity of the rat FSHbeta promoter in a pituitary-derived cell line, LbetaT2. Cells were transiently transfected with the rat FSHbeta promoter fused to a luciferase reporter gene (-338rFSHbeta-Luc), and a minimal activin-responsive region was identified. Transfection of Smad3, but not the highly related Smad2, led to a ligand-independent stimulation of the FSHbeta promoter activity. As expected, activin caused an additional increase of luciferase expression, which was blocked by cotreatment with follistatin. Although Smad4 alone had no effect on FSHbeta transcription, it significantly augmented Smad3 and activin-mediated stimulation of the promoter. A palindromic consensus Smad-binding element in the proximal promoter was found to bind Smad4, and elimination of the region resulted in a loss of activin-mediated FSHbeta transcription. The activin signaling pathway is conserved in a number of cells, but FSHbeta expression is restricted to gonadotropes. A pituitary-specific transcription factor necessary for activin-dependent induction of the FSHbeta promoter has been identified that permits FSHbeta expression in nongonadotrope cells. Pitx2 is a member of Pitx subfamily of bicoid-related homeodomain factors that is required for pituitary development and is present in the adult pituitary. This factor was transfected into LbetaT2 cells, where it caused up-regulation of basal and activin-mediated FSHbeta promoter activity. Furthermore, cotransfection of Pitx2c with Smad3 in kidney-derived TSA cells resulted in activin-regulated FSHbeta response, suggesting its important role in tissue-restricted regulation of FSHbeta by activin. A Pitx2c binding site was identified within the proximal promoter, and elimination of this region also resulted in a loss of activin-regulated FSHbeta promoter activity. Taken together, these studies suggest that the regulation of FSHbeta is dependent on activin-mediated signaling factors in concert with pituitary-derived nuclear regulatory proteins.
Publication
Journal: Fertility and Sterility
December/3/2001
Abstract
OBJECTIVE
To compare reproductive outcome between women with normal ovarian reserve and women with abnormal ovarian reserve.
METHODS
Retrospective.
METHODS
Tertiary care center.
METHODS
Nine thousand eight hundred and two patients who had basal follicle-stimulating hormone (FSH) concentrations measured as part of an infertility evaluation.
METHODS
Monitoring of early pregnancy.
METHODS
Pregnancy loss rates, live birth rates.
RESULTS
Of 1,034 patients with diminished ovarian reserve (DOR) (FSH>> or =14.2 IU/L), 28 (2.7%) conceived. Twenty of these pregnancies (20/28; 71.4%) were lost in the first trimester. Pregnancy loss rates in women with DOR were 57.1% in women <35 years old, 63.5% in women 35-40 years old, and 90.0% in women >40 years old. These rates of pregnancy loss were significantly higher compared to age-matched patients with normal ovarian reserve.
CONCLUSIONS
Women with DOR have exceedingly high rates of pregnancy loss, regardless of age. Women with diminished ovarian reserve should be counseled that, in addition to a low probability of conception, live birth rates are poor.
Pulse
Views:
1
Posts:
No posts
Rating:
Not rated
Publication
Journal: JAMA - Journal of the American Medical Association
October/17/2001
Abstract
BACKGROUND
In reproductive-age women, one of the common adverse effects of chemotherapy and radiotherapy is premature ovarian failure. In addition, a significant number of women experience early menopause due to oophorectomy performed for benign indications.
OBJECTIVE
To develop an ovarian transplantation technique to preserve endocrine function in women undergoing sterilizing radiotherapy and/or chemotherapy, or oophorectomy.
METHODS
Case study of 2 patients in New York who received autologous ovarian transplantation (patient A, November 1999; patient B, April 2000) to the forearm prior to pelvic radiotherapy or after oophorectomy.
METHODS
Patient A is a 35-year-old woman with stage IIIB squamous cell cervical carcinoma and patient B is a 37-year-old woman with recurrent benign ovarian serous cysts.
METHODS
Follicular development evident by ultrasound examination; cyclical production of estradiol and progesterone; restoration of serum follicle-stimulating hormone, luteinizing hormone, and testosterone levels to nonmenopausal range; and disappearance of menopausal symptoms.
RESULTS
Menopause was confirmed immediately after the transplantation in both patients by serum follicle-stimulating hormone measurements (patient A, 47 mIU/mL; patient B, 50.7 mIU/mL). In patient A, follicle development was noted by physical and ultrasound examinations approximately 10 weeks after the transplantation. The mean (SE) follicle-stimulating hormone and luteinizing hormone levels decreased to 8.6 (0.4) mIU/mL and 12.8 (0.8) mIU/mL, respectively. The peripheral estradiol levels showed cyclical variation (mean [SE], 115 [9.2] pg/mL [422 (33.8) pmol/L), and during the 18-month follow-up, a dominant follicle developed each month. The estradiol levels from the right cubital vein were consistent with ovarian vein measurements (mean [SE], 1069 [269] pg/mL [3924 (987.5) pmol/L]). Percutaneous oocyte aspirations yielded a mature oocyte. In patient B, ovarian function was demonstrated by ultrasound visualization of a 9-mm follicle by 6 months after transplantation. Thereafter, the patient had spontaneous menstruation every 25 to 28 days. Ovulation was further confirmed by midluteal progesterone measurements (range, 7-10.1 ng/mL; mean [SE], 8.5 [0.9] ng/mL). Patient B's ovarian graft was still functional 10 months after the transplantation.
CONCLUSIONS
Subcutaneous ovarian transplantation appears to be a relatively simple, novel technique to preserve endocrine function in women undergoing sterilizing cancer therapy or surgery.
Publication
Journal: Frontiers in Neuroendocrinology
December/3/1998
Abstract
Follistatin was first described in 1987 as a follicle-stimulating hormone inhibiting substance present in ovarian follicular fluid. We now know that this effect of follistatin is only one of its many properties in a number of reproductive and nonreproductive systems. A majority of these functions are facilitated through the affinity of follistatin for activin, where activin's effects are neutralized through its binding to follistatin. As such, the interplay between follistatin and activin represents a powerful regulatory mechanism that impinges on a variety of cellular processes within the body. In this review we focus on the biochemical characteristics of follistatin and its interaction with activin and discuss the emerging role of these proteins as potent tissue regulators in the gonad, pituitary gland, pregnancy membranes, vasculature, and liver. Consideration is also given to the larger family of proteins that contain follistatin-like modules, in particular with regard to their functional and structural implications.
Publication
Journal: Journal of Biological Chemistry
June/13/2001
Abstract
The response of granulosa cells to luteinizing hormone (LH) and follicle-stimulating hormone (FSH) is mediated mainly by cAMP/protein kinase A (PKA) signaling. Notably, the activity of the extracellular signal-regulated kinase (ERK) signaling cascade is elevated in response to these stimuli as well. We studied the involvement of the ERK cascade in LH- and FSH-induced steroidogenesis in two granulosa-derived cell lines, rLHR-4 and rFSHR-17, respectively. We found that stimulation of these cells with the appropriate gonadotropin induced ERK activation as well as progesterone production downstream of PKA. Inhibition of ERK activity enhanced gonadotropin-stimulated progesterone production, which was correlated with increased expression of the steroidogenic acute regulatory protein (StAR), a key regulator of progesterone synthesis. Therefore, it is likely that gonadotropin-stimulated progesterone formation is regulated by a pathway that includes PKA and StAR, and this process is down-regulated by ERK, due to attenuation of StAR expression. Our results suggest that activation of PKA signaling by gonadotropins not only induces steroidogenesis but also activates down-regulation machinery involving the ERK cascade. The activation of ERK by gonadotropins as well as by other agents may be a key mechanism for the modulation of gonadotropin-induced steroidogenesis.
Publication
Journal: Journal of Biological Chemistry
February/16/1988
Abstract
We have elucidated the structures of the anionic asparagine-linked oligosaccharides present on the glycoprotein hormones lutropin (luteinizing hormone), follitropin (follicle-stimulating hormone), and thyrotropin (thyroid-stimulating hormone). Purified hormones, isolated from bovine, ovine, and human pituitaries, were digested with N-glycanase, and the released oligosaccharides were reduced with NaB[3H]4. The 3H-labeled oligosaccharides from each hormone were then fractionated by anion-exchange high performance liquid chromatography (HPLC) into populations differing in the number of sulfate and/or sialic acid moieties. The anionic oligosaccharides were further purified as well as structurally characterized using a variety of preparative and analytical techniques, including HPLC, endo- and exoglycosidase digestions, and lectin affinity chromatography. The sulfated, sialylated, and sulfated/sialylated structures, which together comprised 67-90% of the asparagine-linked oligosaccharides on the pituitary glycoprotein hormones, were highly heterogeneous and displayed hormone- as well as animal species-specific features. The sulfated oligosaccharides consisted of hybrid and complex type oligosaccharides with one or two branches terminating in SO4-4GalNAc beta 1,4. In contrast, the sialylated oligosaccharides consisted of a wide array of differing structures containing two or three peripheral branches as well as one, two, or three sialic acid moieties. A previously uncharacterized dibranched oligosaccharide, bearing one residue each of sulfate and sialic acid, was found on all of the hormones except bovine lutropin. In this study, we describe the purification and detailed structural characterizations of the sulfated, sialylated, and sulfated/sialylated oligosaccharides found on lutropin, follitropin, and thyrotropin from several animal species. In the accompanying paper (Green, E.D., and Baenziger, J.U.(1987) J. Biol. Chem. 262, 36-44) we demonstrate the marked quantitative differences among the pituitary glycoprotein hormones in terms of sulfation, sialylation, and underlying oligosaccharide structures, as well as provide evidence for site-specific synthesis of oligosaccharides on individual hormones.
Publication
Journal: Biology of Reproduction
September/12/2006
Abstract
The frequency of gonadotropin-releasing hormone (GNRH1, or GnRH) pulses secreted from the hypothalamus determine the ratios of the gonadotropin subunit genes luteinizing hormone beta (Lhb), follicle-stimulating hormone beta (Fshb) and the common alpha-glycoprotein subunit gene (Cga) transcribed in the anterior pituitaries of mammals. Fshb is preferentially transcribed at slower GNRH1 pulse frequencies, whereas Lhb and Cga are preferentially transcribed at more rapid pulse frequencies. Producing the gonadotropins in the correct proportions is critical for normal fertility. Currently, there is no definitive explanation for how GNRH1 pulses differentially activate gonadotropin subunit gene transcription. Several pathways may contribute to this regulation. For example, GNRH1-regulated GNRH1-receptor concentrations may lead to variable signaling pathway activation. Several signaling pathways are activated by GnRH, including mitogen-activated protein kinase, protein kinase C, calcium influx, and calcium-calmodulin kinase, and these may be preferentially regulated under certain conditions. In addition, some signaling proteins feed back to downregulate their own levels. Other arms of gonadotroph signaling appear to be regulated by synthesis, modification, and degradation of either transcription factors or regulatory proteins. Finally, the dynamic binding of proteins to the chromatin, and how that might be regulated by chromatin-modifying proteins, is addressed. Oscillations in expression, modification, and chromatin binding of the proteins involved in gonadotropin gene expression are likely a link between GNRH1 pulsatility and differential gonadotropin transcription.
Publication
Journal: Journal of Biological Chemistry
May/13/2009
Abstract
Follistatin is a transcriptional target and a modulator of activin action. Through an autocrine/paracrine loop, activin controls follistatin levels and thus regulates its own bioavailability. In gonadotropic alphaT3-1 cells, activin induces follistatin transcription primarily through the action of Smad3 at an intronic Smad-binding element (SBE1). Using a proteomics approach, we searched for endogenous alphaT3-1 proteins that participate in SBE1-mediated transcription. We identified FoxL2, a member of the forkhead family, as a candidate modulator of SBE1 function. Mutations of FoxL2 are associated with the blepharophimosis/ptosis/epicanthus inversus syndrome characterized with craniofacial defects and premature ovarian failure. FoxL2 localizes to alpha-glycoprotein subunit- and follicle-stimulating hormone beta-positive cells of the adult mouse pituitary and is present in alphaT3-1 and LbetaT2 cells, but its pituitary actions remain largely unknown. We have determined that FoxL2 binds to a forkhead-binding element (FKHB) located just downstream of the SBE1 site of the follistatin gene and functions as a Smad3 partner to drive SBE1-mediated transcription in alphaT3-1 cells treated with activin. Chromatin immunoprecipitation assays confirm that endogenous FoxL2 and Smad3 are recruited to the intronic enhancer of the follistatin gene where the SBE1 and FKHB sites are located. Exogenous FoxL2 enhances SBE1-mediated transcription, and short hairpin RNA-mediated knockdown of endogenous FoxL2 protein compromises this effect in alphaT3-1 cells. FoxL2 directly associates with Smad3 but not Smad2 or Smad4. This association between Smad3 and FoxL2 is mediated by the MH2 domain of Smad3 and is dependent on an intact forkhead domain in FoxL2. Altogether, these observations highlight a novel role for FoxL2 and suggest that it may function as a transcriptional regulator and a coordinator of Smad3 targets.
Publication
Journal: Journal of Bone and Mineral Research
March/12/2012
Abstract
Sclerostin is a secreted Wnt antagonist produced almost exclusively by osteocytes that regulates bone mass. However, there is currently limited information on the determinants of sclerostin in a large population-based study. The main objectives of the present study were to: (1) establish reference normative interval values for serum sclerostin in randomly selected healthy premenopausal women; (2) study the changes in serum sclerostin in relation to age in premenopausal and postmenopausal women and the factors that may influence bone turnover; and (3) determine the effect of menopausal status on serum sclerostin. A total of 1803 women were studied (including [n = 1235] premenopausal, and [n = 568] postmenopausal women, respectively, aged 20 to 79 years). A total of 443 healthy premenopausal women (aged 35 to 45 years) were used to establish reference normative intervals for serum sclerostin. All women studied were medically examined and had their bone mineral density values obtained for the lumbar spine (L(1) -L(4) ) and femoral neck according to a detailed inclusion criteria. In all women, values of serum sclerostin increased with increasing age up to the age of 45 years, and remained increased in postmenopausal women. Significant increases were evident in serum sclerostin in postmenopausal women with increasing years since menopause. Using stepwise multiple linear regression analysis, several variables were identified as determinants of serum sclerostin, including age, parathyroid hormone, estradiol (E(2)), and follicle-stimulating hormone (FSH) for premenopausal women; age, FSH, and E(2) for postmenopausal women; and age, serum osteocalcin, FSH, and E(2) in the entire sample studied. Further studies are needed to establish the potential role of this increase in mediating the known age-related impairment in bone formation.
Publication
Journal: Journal of Bone and Mineral Research
July/15/2009
Abstract
The effects of ACE-011 on safety, pharmacokinetics, and bone biomarkers were evaluated in healthy, postmenopausal women. Our data indicate that ACE-011 results in a sustained increase in biomarkers of bone formation and reduction in markers of bone resorption. The activin type IIA receptor (ActRIIA) is the high-affinity receptor for activin. ACE-011 is a dimeric fusion protein consisting of the extracellular domain of the human ActRIIA linked to the Fc portion of human IgG1. ACE-011 binds to activin, preventing activin from binding endogenous receptors. A randomized, double-blind, placebo-controlled study was conducted to evaluate the safety and tolerability of ACE-011. Forty-eight healthy, postmenopausal women were randomized to receive either a single dose of ACE-011 or placebo and were followed for 4 mo. Dose levels ranged from 0.01 to 3.0 mg/kg intravenously and from 0.03 to 0.1 mg/kg subcutaneously. Safety and pharmacokinetic (PK) analyses and the biological activity of ACE-011, as assessed by markers of bone turnover, and follicle stimulating hormone (FSH) levels were measured. No serious adverse events (AEs) were reported. AEs were generally mild and transient. The PK of ACE-011 was linear over the dose range studied, with a mean half-life of 24-32 days. The absorption after subcutaneous dosing was essentially complete. ACE-011 caused a rapid and sustained dose-dependent increase in serum levels of bone-specific alkaline phosphatase (BSALP) and a dose-dependent decrease in C-terminal type 1 collagen telopeptide (CTX) and TRACP-5b levels. There was also a dose-dependent decrease in serum FSH levels consistent with inhibition of activin. ACE-011 is a novel agent with biological evidence of both an increase in bone formation and a decrease in bone resorption. ACE-011 may be an effective therapy in a variety of diseases involving bone loss.
Publication
Journal: American Journal of Clinical Nutrition
October/8/2009
Abstract
BACKGROUND
High-fiber diets have been associated with decreased breast cancer risk, likely mediated by the effect of fiber on lowering circulating estrogen concentrations. The influence of fiber on aspects of reproduction, which include ovulation, has not been well studied in premenopausal women.
OBJECTIVE
The objective was to determine if fiber consumption is associated with hormone concentrations and incident anovulation in healthy, regularly menstruating women.
METHODS
The BioCycle Study was a prospective cohort study conducted from 2004 to 2006 that followed 250 women aged 18-44 y for 2 cycles. Dietary fiber consumption was assessed < or =4 times/cycle by using 24-h recall. Outcomes included concentrations of estradiol, progesterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH), which were measured < or =8 times/cycle, and incident anovulation.
RESULTS
Dietary fiber consumption was inversely associated with hormone concentrations (estradiol, progesterone, LH, and FSH; P < 0.05) and positively associated with the risk of anovulation (P = 0.003) by using random-effects models with adjustment for total calories, age, race, and vitamin E intake. Each 5-g/d increase in total fiber intake was associated with a 1.78-fold increased risk (95% CI: 1.11, 2.84) of an anovulatory cycle. The adjusted odds ratio of 5 g fruit fiber/d was 3.05 (95% CI: 1.07, 8.71).
CONCLUSIONS
These findings suggest that a diet high in fiber is significantly associated with decreased hormone concentrations and a higher probability of anovulation. Further study of the effect of fiber on reproductive health and of the effect of these intakes in reproductive-aged women is warranted.
Publication
Journal: Cancer
March/7/2001
Abstract
BACKGROUND
Therapy with alkylating agents, such as cyclophosphamide, can be associated with irreversible gonadal toxicity in male survivors of adult cancer. To the authors's knowledge the effect of high dose therapy with cyclophosphamide during childhood on adult testicular reproductive and endocrine function has not been established.
METHODS
Gonadal function was studied in 17 adult male survivors of childhood sarcomas treated with high dose pulse cyclophosphamide therapy as part of a VAC (vincristine, actinomycin, and cyclophosphamide) or Adria-VAC (doxorubicin, vincristine, actinomycin, and cyclophosphamide) chemotherapy regimen. Patients answered a questionnaire concerning sexual functioning and underwent a comprehensive physical examination, semen analysis, and hormonal evaluation.
RESULTS
Of the 17 males who underwent semen analysis, 10 (58.8%) had azoospermia, 5 (29.4%) had oligospermia, and only 2 (11.8%) were found to have a normal sperm count. All patients treated prior to the onset of puberty had an abnormal semen analysis. The 2 patients with normal sperm counts received the lowest doses of cyclophosphamide (< 7.5 g/m(2)). The baseline follicle-stimulating hormone level was elevated in only 10 of 14 patients with abnormal sperm counts (71.4%). Testosterone levels were normal in 15 of 16 patients (93.8%); however, the baseline luteinizing hormone (LH) level was elevated in 6 of 15 patients with normal testosterone levels (40%). Gonadotropin-releasing hormone-stimulated LH levels were>> 3 times that of baseline in 13 of /14 patients (92.9%), suggesting some degree of Leydig cell insufficiency.
CONCLUSIONS
The results of the current study show a high risk of gonadal dysfunction in men exposed to cyclophosphamide during childhood as part of a VAC/Adria-VAC chemotherapy regimen. Exposure prior to puberty was not found to be protective, and the risk of infertility appeared to increase with higher doses of therapy. To the authors' knowledge the clinical significance of impaired Leydig cell function beginning at a young age is unknown and merits further study.
Publication
Journal: Human Reproduction
March/6/2000
Abstract
Male reproductive function seems to have deteriorated considerably during the past 4-5 decades. However, studies of the reproductive function in unselected populations have not previously been reported. As the large majority of young men in Denmark are subjected to a compulsory medical examination for military service, this provided a unique opportunity to study the reproductive function in an unbiased population. Altogether 891 young men delivered a blood sample in which reproductive hormones were measured. From 708 of these men data were also obtained on semen quality and testis size. The median sperm concentration was 41 x 10(6)/ml (mean 57.4 x 10(6)/ml). Men with ejaculation abstinence above 48 h had slightly higher sperm concentrations (median 45 x10(6)/ml, mean 63.2 x 10(6)/ml), but even in this subgroup, 21 and 43% respectively had sperm counts below 20 x 10(6)/ml and 40 x 10(6)/ml. Among men with no history of reproductive diseases and a period of abstinence above 48 h, as many as 18 and 40% respectively had concentrations below 20 and 40 x 10(6)/ml. Sperm counts were positively correlated with testis size, percentage normal spermatozoa and inhibin B, and negatively correlated with percentage immotile spermatozoa and follicle stimulating hormone. Possible causes for this high frequency of young men with suboptimal semen quality are obscure and need to be explored. Whether these findings apply for young male populations of comparable countries remains to be seen.
Publication
Journal: Proceedings of the National Academy of Sciences of the United States of America
July/18/1999
Abstract
Bone morphogenetic proteins (BMPs) comprise a large group of polypeptides in the transforming growth factor beta superfamily with essential physiological functions in morphogenesis and organogenesis in both vertebrates and invertebrates. At present, the role of BMPs in the reproductive system of any species is poorly understood. Here, we have established the existence of a functional BMP system in the ovary, replete with ligand, receptor, and novel cellular functions. In situ hybridization histochemistry identified strong mRNA labeling for BMP-4 and -7 in the theca cells and BMP receptor types IA, IB, and II in the granulosa cells and oocytes of most follicles in ovaries of normal cycling rats. To explore the paracrine function of this BMP system, we examined the effects of recombinant BMP-4 and -7 on FSH (follicle-stimulating hormone)-induced rat granulosa cytodifferentiation in serum-free medium. Both BMP-4 and -7 regulated FSH action in positive and negative ways. Specifically, physiological concentrations of the BMPs enhanced and attenuated the stimulatory action of FSH on estradiol and progesterone production, respectively. These effects were dose- and time-dependent. Furthermore, the BMPs increased granulosa cell sensitivity to FSH. Thus, BMPs have now been identified as molecules that differentially regulate FSH-dependent estradiol and progesterone production in a way that reflects steroidogenesis during the normal estrous cycle. As such, it can be hypothesized that BMPs might be the long-sought "luteinization inhibitor" in Graafian follicles during their growth and development.
Publication
Journal: Environmental Health Perspectives
August/23/2011
Abstract
BACKGROUND
In recent decades, young men in some industrialized areas have reportedly experienced a decrease in semen quality.
OBJECTIVE
We examined effects of perinatal dioxin exposure on sperm quality and reproductive hormones.
METHODS
We investigated sperm quality and hormone concentrations in 39 sons (mean age, 22.5 years) born between 1977 and 1984 to mothers exposed to dioxin after the accident in Seveso, Italy (1976), and 58 comparisons (mean age, 24.6 years) born to mothers exposed only to background dioxin. Maternal dioxin levels at conception were extrapolated from the concentrations measured in 1976 serum samples.
RESULTS
The 21 breast-fed sons whose exposed mothers had a median serum dioxin concentration as low as 19 ppt at conception had lower sperm concentration (36.3 vs. 86.3 million/mL; p = 0.002), total count (116.9 vs. 231.1; p = 0.02), progressive motility (35.8 vs. 44.2%; p = 0.03), and total motile count (38.7 vs. 98 million; p = 0.01) than did the 36 breast-fed comparisons. The 18 formula-fed exposed and the 22 formula-fed and 36 breast-fed comparisons (maternal dioxin background 10 ppt at conception) had no sperm-related differences. Follicle-stimulating hormone was higher in the breast-fed exposed group than in the breast-fed comparisons (4.1 vs. 2.63 IU/L; p = 0.03) or the formula-fed exposed (4.1 vs. 2.6 IU/L; p = 0.04), and inhibin B was lower (breast-fed exposed group, 70.2; breast-fed comparisons, 101.8 pg/mL, p = 0.01; formula-fed exposed, 99.9 pg/mL, p = 0.02).
CONCLUSIONS
In utero and lactational exposure of children to relatively low dioxin doses can permanently reduce sperm quality.
Publication
Journal: Fertility and Sterility
March/20/2006
Abstract
OBJECTIVE
To determine the predictive value of antimüllerian hormone (AMH) as a marker for ovarian reserve and to compare its value with the markers currently being used.
METHODS
Prospective analysis.
METHODS
In vitro fertilization (IVF) clinic of a tertiary medical center.
METHODS
Fifty women undergoing assisted reproduction cycles.
METHODS
None.
METHODS
Comparison of day-3 serum AMH levels among women with less than five retrieved oocytes and five or more oocytes. Antral follicle count, mature oocyte count, age, basal follicle-stimulating hormone (FSH), estradiol (E2), maximum serum E2 levels, and pregnancy success were also compared.
RESULTS
The mean serum AMH levels of patients with more than five retrieved oocytes were found to be higher (0.67 +/- 0.41 vs. 0.15 +/- 0.11 pg/mL). Mature oocyte counts, antral follicle counts, and maximum E2 levels were found to be statistically significantly different in the two groups despite similar ages and levels of basal FSH and E2. Although the receiver operator characteristics analysis revealed that the most sensitive and specific indicator of ovarian reserve is the level of AMH, it does not indicate pregnancy success as well when 0.25 pg/mL is taken as a cut-off value.
CONCLUSIONS
These data demonstrate an association between early follicular serum AMH and ovarian response, but no association with pregnancy success.
Publication
Journal: Urology
December/12/2005
Abstract
OBJECTIVE
To compare, in a retrospective study, the ultrasound findings and hormonal changes after testicular sperm extraction (TESE) using the conventional multiple biopsy approach and the more recent microdissection technique. TESE has been performed using the conventional multiple biopsy approach and the more recent microdissection technique.
METHODS
A total of 435 men with nonobstructive azoospermia who had undergone 543 TESE attempts were included in the study. The initial 83 attempts were done using the conventional open technique and the remaining 460 attempts were performed by microdissection. The sperm retrieval rates were compared, as were the complication rates as assessed by ultrasound and endocrinologic evaluations between the two groups.
RESULTS
The retrieval rate by the conventional technique was 32% and by microdissection was 57% (P = 0.0002). In patients with hypospermatogenesis, the retrieval rate differed between the two approaches (P = 0.03). Ultrasound findings demonstrated fewer acute and chronic changes in the microdissection group than in the conventional group (P < 0.05). At 3 to 6 months after surgery, the testosterone levels had dropped to 80% of their pre-TESE levels in both groups (P < 0.01). The levels rose back to 85% after 12 months and to 95% after 18 months. The mean follicle-stimulating hormone levels increased from 22 +/- 2 to 30 +/- 3 IU/L (P = 0.02), and the luteinizing hormone levels increased from 12 +/- 2 to 16 +/- 2 IU/L (P = 0.2).
CONCLUSIONS
TESE has effects on testicular function, but the microdissection procedure is relatively safer than the conventional technique and improves the sperm retrieval rate significantly in patients with nonobstructive azoospermia.
Publication
Journal: Calcified Tissue International
April/21/1997
Abstract
The purpose of this study was to determine the prevalence of osteoporosis, to estimate the bone turnover and hormonal status, and to identify the factors associated with bone disease in patients with end-stage liver disease who were referred for orthotopic liver transplantation. A prospective study was performed on 58 cirrhotic patients (6 with primary biliary cirrhosis, 14 with alcoholic cirrhosis, and 38 with posthepatitic cirrhosis), who were referred for orthotopic liver transplantation. Patients, excluding those with primary biliary cirrhosis, were classified in Child-Pugh groups according to the severity of liver disease (class B [28 patients], class C [24 patients]). Biochemical parameters of bone mineral metabolism and standard liver function tests were measured in all patients. Additionally, serum osteocalcin, urinary hydroxyproline/creatinine ratio, serum intact parathyroid hormone, serum 25-hydroxyvitamin D, serum 1,25-dihydroxyvitamin D, follicle-stimulating hormone, and luteinizing hormone levels were determined in patients and controls within the same age range. Plasma testosterone, sex hormone-binding globulin levels, and free testosterone index were obtained for all men included in the study. Bone mass of the lumbar spine and femur were measured by dual X-ray absorptiometry (DPX-L), and were expressed as a standard deviation of mean values (Z-score) from a sex and age-matched control group. Spinal X-rays were obtained to assess vertebral fractures. Osteoporosis was considered as a factor in spinal bone mineral density with a Z-score below 2 or at least one vertebral fracture. Twenty-five patients (43%) had osteoporosis, with lower bone mass measurements in the lumbar spine than in the femoral neck (P < 0.005). Alcoholic and Child-Pugh C patients showed the lowest femoral bone mineral density values. Cirrhotic patients showed lower osteocalcin levels than controls (14.3 +/- 5.9 vs. 18.2 +/- 8.1 ng/ml; P < 0.05) and showed increased urinary hydroxyproline (125.1 +/- 51.5 vs. 107.9 +/- 26.6 nM/mg creatinine; P < 0.05). Serum 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D and parathyroid hormone levels were significantly lower in cirrhotic patients than in controls (10.3 +/- 9.1 vs. 23.1 +/- 26.6 ng/ml; P = 0.000), (12.9 +/- 9.1 vs. 48.3 +/- 11.5 pg/ml; P = 0.000), (16.6 +/- 9.2 vs. 27.9 +/- 8.2 pg/ml; P = 0.000), with no differences between Child-Pugh groups. Alcoholic Child-Pugh C patients showed the lowest 25-hydroxyvitamin D serum values (4.5 +/- 2.2 ng/ml; P < 0.05). Male patients had lower testosterone levels than controls (302.5 +/- 229.4 vs. 556.7 +/- 146.5 ng/dl; P = 0.000), with increased sex hormone-binding globulin values. Levels of testosterone and gonadotropin were related to Child-Pugh classification. No correlation was found between bone mass and hormonal values. A significant decrease in bone mass, particularly in the lumbar spine, is seen in end-stage cirrhotic patients. Reduced bone formation and significant disorders of bone mineral metabolism, such as vitamin D deficiency, reduced parathyroid hormone levels, and hypogonadism are involved. Moreover, severity and etiology of the liver disease are the main risk factors for developing bone loss and mineral metabolism disorders in patients referred for orthotopic liver transplantation.
load more...