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Publication
Journal: Journal of Ovarian Research
April/28/2013
Abstract
BACKGROUND
Cryopreserved ovarian cortical tissue acts as a source of primordial follicles (PF) which can either be auto-transplanted or cultured in vitro to obtain mature oocytes. This offers a good opportunity to attain biological parenthood to individuals with gonadal insufficiency including cancer survivors. However, role of various intra- and extra-ovarian factors during PF growth initiation still remain poorly understood. Ovarian biology has assumed a different dimension due to emerging data on presence of pluripotent very small embryonic-like stem cells (VSELs) and ovarian germ stem cells (OGSCs) in ovary surface epithelium (OSE) and the concept of postnatal oogenesis. The present study was undertaken to decipher effect of follicle stimulating hormone (FSH) and basic fibroblast growth factor (bFGF) on the growth initiation of PF during organ culture with a focus on ovarian stem cells.
METHODS
Serum-free cultures of marmoset (n=3) and human (young and peri-menopausal) ovarian cortical tissue pieces were established. Cortical tissue pieces stimulated with FSH (0.5 IU/ml) or bFGF (100 ng/ml) were collected on Day 3 for histological and molecular studies. Gene transcripts specific for pluripotency (Oct-4A, Nanog), early germ cells (Oct-4, c-Kit, Vasa) and to reflect PF growth initiation (oocyte-specific Gdf-9 and Lhx8, and granulosa cells specific Amh) were studied by q-RTPCR.
RESULTS
A prominent proliferation of OSE (which harbors stem cells) and transition of PF to primary follicles was observed after FSH and bFGF treatment. Ovarian stem cells were found to be released on the culture inserts and retained the potential to spontaneously differentiate into oocyte-like structures in extended cultures. q-RTPCR analysis revealed an increased expression of gene transcripts specific for VSELs, OGSCs and early germ cells suggestive of follicular transition.
CONCLUSIONS
The present study shows that both FSH and bFGF stimulate stem cells present in OSE and also lead to PF growth initiation. Thus besides being a source of PF, cryopreserved ovarian cortical tissue could also be a source of stem cells which retain the ability to spontaneously differentiate into oocyte-like structures in vitro. Results provide a paradigm shift in the basic understanding of FSH action and also offer a new perspective to the field of oncofertility research.
Publication
Journal: Stem Cells and Development
December/23/2015
Abstract
Evidence has accumulated that hematopoietic stem progenitor cells (HSPCs) share several markers with the germline, a connection supported by reports that prolactin, androgens, and estrogens stimulate hematopoiesis. To address this issue more directly, we tested the expression of receptors for pituitary-derived hormones, such as follicle-stimulating hormone (FSH) and luteinizing hormone (LH), on purified murine bone marrow (BM) cells enriched for HSPCs and tested the functionality of these receptors in ex vivo signal transduction studies and in vitro clonogenic assays. We also tested whether administration of pituitary- and gonad-derived sex hormones (SexHs) increases incorporation of bromodeoxyuridine (BrdU) into HSPCs and expansion of hematopoietic clonogenic progenitors in mice and promotes recovery of blood counts in sublethally irradiated animals. We report for the first time that HSPCs express functional FSH and LH receptors and that both proliferate in vivo and in vitro in response to stimulation by pituitary SexHs. Furthermore, based on our observations that at least some of CD45(-) very small embryonic-like stem cells (VSELs) may become specified into CD45(+) HSPCs, we also evaluated the expression of pituitary and gonadal SexHs receptors on these cells and tested whether these quiescent cells may expand in vivo in response to SexHs administration. We found that VSELs express SexHs receptors and respond in vivo to SexHs stimulation, as evidenced by BrdU accumulation. Since at least some VSELs share several markers characteristic of migrating primordial germ cells and can be specified into HSPCs, this observation sheds new light on the BM stem cell hierarchy.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
August/6/1997
Abstract
Granulosa cells in the ovulatory follicle express messenger ribonucleic acid encoding vascular endothelial growth factor (VEGF), an agent that may mediate the neovascularization of the developing corpus luteum, but it is not known whether luteinizing granulosa cells synthesize and secrete VEGF during the periovulatory interval. Studies were designed to evaluate the effects of an in vivo gonadotropin surge on VEGF production by macaque granulosa cells (study 1) and to test the hypothesis that gonadotropins act directly on granulosa cells to regulate VEGF production (study 2). Monkeys received a regimen of exogenous gonadotropins to promote the development of multiple preovulatory follicles. Nonluteinized granulosa cells (i.e. preovulatory; NLGC) and luteinized granulosa cells (i.e. periovulatory; LGC) were aspirated from follicles before and 27 h after an ovulatory gonadotropin bolus, respectively. Cells were either incubated for 24 h in medium with or without 100 ng/mL hCG (study 1) or cultured for 6 days in medium with or without 100 ng/mL hCG or 0.1, 1, 10, and 100 ng/mL of recombinant human LH (r-hLH) or r-hFSH (study 2). Culture medium was assayed for VEGF and progesterone. In study 1, LGC produced 8-fold greater levels of VEGF than NLGC (899 +/- 471 vs. 111 +/- 26 pg/mL, mean +/- SEM; P < 0.05). In vitro treatment with hCG increased (P < 0.05) VEGF production by NLGC to levels that were not different from the LGC incubated under control conditions. In vivo bolus doses of r-hCG (100 and 1000 IU) and r-hFSH (2500 IU) were equally effective in elevating granulosa cell VEGF production. In study 2, in vitro treatment with r-hFSH, r-hLH, and hCG markedly increased (P < 0.05) VEGF and progesterone production by the NLGC in a dose- and time-dependent manner. By comparison, the three gonadotropins (100 ng/mL dose) only modestly increased VEGF and progesterone production by LGC. These experiments demonstrate a novel role for the midcycle surge of gonadotropin (LH/CG or FSH) in primates to promote VEGF production by granulosa cells in the periovulatory follicle. Further, the data demonstrate that FSH-like as well as LH-like gonadotropins directly stimulate VEGF synthesis by granulosa cells.
Publication
Journal: Biology of Reproduction
May/8/2012
Abstract
Copper/zinc superoxide dismutase (CuZn-SOD, SOD1) is one of the major antioxidant enzymes, and is localized in the cytoplasm to scavenge superoxide. To investigate the physiological role of SOD1 in the ovaries, we analyzed the fertility of Sod1-deficient female mice. To evaluate their hormonal metabolism, we measured pituitary and ovarian hormone levels in the plasma of the mutant mice. Plasma follicle-stimulating hormone, luteinizing hormone, and estradiol were not altered in the mutant compared to the wild-type females, while the plasma progesterone level was significantly reduced in the mutant females. Furthermore, the mutant mice showed decreased progesterone secretion under the condition of superovulation. In a histochemical analysis, we observed a remarkable reduction in the corpus luteum area in the mutant ovaries without atrophic changes. The mutant mice also displayed enhanced superoxide generation in the region surrounding the corpora lutea, which was associated with increased apoptotic cells and suppressed vasculature. These results suggested that SOD1 deficiency dysregulated luteal formation because of increased superoxide generation in the ovary. In vitro fertilization experiments showed no abnormal fertilization of Sod1-deficient oocytes. In addition, when Sod1-deficient embryos were transferred into the oviducts of wild-type females, mutant embryos developed at a normal rate, indicating that SOD1 deficiency in embryos did not cause miscarriage in the uterus of wild-type females. These results indicated that increased intracellular ROS impaired luteal formation and progesterone production in the mutant females, thus suggesting that SOD1 plays a crucial role in both the luteal function and the maintenance of fertility in female mice.
Publication
Journal: Fertility and Sterility
January/22/1997
Abstract
OBJECTIVE
To assess the efficacy of a novel protocol-microdose GnRH agonist (GnRH-a), FSH, and GH, for the stimulation of IVF patients who were canceled previously on a standard luteal GnRH-a, FSH, GH protocol.
METHODS
Prospective evaluation using the patient's previous IVF stimulation attempt as historic controls.
METHODS
Private practice assisted reproductive technology center.
METHODS
Thirty-two patients who had prior ovulation induction cycles canceled using luteal phase GnRH-a suppression followed by exogenous gonadotropins and GH.
METHODS
Precycle treatment with oral contraceptives followed by follicular phase administration of 40 micrograms leuprolide acetate every 12 hours beginning on cycle day 3 and FSH supplemented with GH beginning on cycle day 5.
METHODS
Paired analysis of E2 day 5, number of follicles, ampules of FSH required, and cancellation rate. The number of oocytes, embryos, embryo quality, implantation rate, and pregnancy rate (PR) were determined for completed cycles on the microdose GnRH-a, FSH, GH protocol.
RESULTS
Controlled ovarian hyperstimulation was superior during microdose GnRH-a, FSH, GH stimulation when compared with the prior luteal GnRH-a cycle. Specifically, there was a higher E2 response, more oocytes, fewer cycle cancellations, and no premature LH surge or luteinization. The microdose GnRH-a, FSH, GH protocol produced an average of 10 oocytes and a 50% ongoing PR.
CONCLUSIONS
The microdose GnRH-a, FSH, GH protocol is superior to standard protocols for the treatment of patients with decreased ovarian reserve undergoing controlled ovarian hyperstimulation for IVF.
Publication
Journal: Endocrinology
August/31/1976
Abstract
Antisera to oLHbeta subunits were used to identify the gonadotrophic cells in partes distalis and tuberalis of the rhesus monkey pituitary gland. The same cell type in pituitary glands obtained from male and female rhesus monkeys stained with both antisera. Immunocytochemical staining was observed in PAS positive cells that were randomly dispersed throughout the entire pars distalis. The gonadotrophs did not react with antisera to either hTSHbeta or oACTH. These observations indicate that only one gonadotrophic cell type is present in the primate pituitary gland.
Publication
Journal: American Journal of Epidemiology
July/18/2001
Abstract
The purpose of this cross-sectional analysis of women aged 35-49 years from the Third National Health and Nutrition Examination Survey, conducted between 1988 and 1994, was to assess associations with menopausal status based either on menstrual cycle patterns or on elevated (>20 IU/liter) follicle-stimulating hormone. Menstrual cycle-based menopausal status was defined for women who had not had surgical menopause by months since the last period (<2, 2-12, and >12 months for pre-, peri-, and postmenopause, respectively). Logistic regression was adjusted for age, smoking, and unilateral oophorectomy. Higher body mass index >> or =30 kg/m(2) compared with < 25.0 kg/m(2)) was associated with a lower likelihood of elevated follicle-stimulating hormone (odds ratio (OR)=0.6, 95% confidence interval (CI): 0.4, 0.9) but this association was not seen with the menstrual measure of menopause. Exercise (three or more times per week) was associated with a lower likelihood of being postmenopausal on the basis of menstrual (OR = 0.3, 95% CI: 0.2, 0.7) and hormonal (OR = 0.6, 95% CI: 0.4, 1.0) measures. Alcohol use also tended to be associated with postmenopausal status by either measure, but not significantly so. There was little evidence of associations with ethnicity, education, age at menarche, number of livebirths, and oral contraceptive use. Menstrual-based definitions of menopause can be misclassified for women with menstrual irregularity. This might explain why obese women were classified menstrually as menopausal while remaining hormonally premenopausal.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
September/13/2005
Abstract
BACKGROUND
FSH is essential for follicular maturation. Data from ovarian hyperstimulation cycles suggest that FSH action is attenuated by a frequent single nucleotide polymorphism of the FSH receptor gene exchanging Asn for Ser at codon 680.
OBJECTIVE
We hypothesized that the FSH receptor genotype influences menstrual cycle dynamics.
METHODS
Menstrual cycle was monitored from the midluteal phase through ovulation until the consecutive menstruation.
METHODS
The study was conducted at the University research center.
METHODS
Women homozygous for the Asn680 (n = 12) and Ser680 (n = 9) variants with normal menstrual cycles volunteered for the study.
METHODS
There were no interventions.
METHODS
Follicular growth, serum LH, FSH, estradiol, progesterone, inhibin A, inhibin B and antimullerian hormone were measured.
RESULTS
During the luteo-follicular transition, serum levels of estradiol, progesterone, and inhibin A were significantly lower, and FSH started to rise earlier in the Ser680/Ser680 group. FSH levels were steadily and significantly higher, and the mean area under the FSH curve was 31% greater in this group (P < 0.002). No differences were observed in estradiol, inhibin B, and growth velocities of dominant follicles. The time from luteolysis to ovulation was significantly longer in women with the Ser680/Ser680 (13.6 +/- 1.01 d) compared with Asn680/Asn680 (11.3 +/- 0.61 d, P < 0.05) genotype with a significant difference in total menstrual cycle length (29.3 vs. 27.0 d, respectively; P < 0.05).
CONCLUSIONS
The FSH receptor Ser680/Ser680 genotype is associated with higher ovarian threshold to FSH, decreased negative feedback of luteal secretion to the pituitary during the intercycle transition, and longer menstrual cycles.
Publication
Journal: Hormone and Metabolic Research
October/17/2001
Abstract
Normal gonadal function is critically dependent on the integrity of pituitary-gonadal axis, where follicle-stimulating hormone (FSH) plays a key role. In the female, FSH is required for follicular growth, estrogen production and oocyte maturation. Its function is mediated by its specific receptor (FSHR), and defective FSHR has been shown to affect folliculogenesis and ovarian function. In this study, we screened the entire coding region of FSHR gene for pathogenic mutations in women with premature ovarian failure (POF) (n = 16) and polycystic ovary syndrome (PCOS) (n = 124) and found no mutations in these patients. Two known polymorphisms, Thr307Ala and Ser680Asn showed similar distributions of the allelic variations and protein isoforms in PCOS and normal control subjects (n = 236). It appears from this study that mutations in the coding regions of FSHR gene are not a causative factor of the above clinical manifestations in Chinese Singapore women.
Publication
Journal: The Lancet
May/15/1979
Abstract
The effect of cyclical chemotherapy on fertility and gonadal function was investigated in seventy-four male patients who had been treated for advanced Hodgkin's disease. All patients were azoospermic after therapy, and, with a median follow-up period of 27 months (range 1--62 months), only four patients have regained spermatogenesis. Testicular biopsy showed an absence of germinal epithelium without other gross architectural changes. Despite this high degree of infertility, 60% of patients were practising contraception. A decline in libido and sexual performance with frequent long periods of sexual inactivity was noted by most men during therapy. Although some recovery was apparent once therapy was stopped, this was incomplete in approximately half of the patients. Follicle-stimulating-hormone levels were consistently raised after therapy at all periods of study. Median luteinising-hormone levels were at, or just above, the upper limit of normal, and median testosterone levels were normal. Increased prolactin levels were noted in 42% of patients, of whom about a half had an identifiable cause for hyperprolactinaemia. Return of spermatogenesis could not be predicted by serial hormone assessment. Because of the guaranteed infertility and the low frequency and unpredictability of recovery of spermatogenesis, sperm storage should be available for male patients undergoing cytotoxic therapy, since most of these patients may enjoy prolonged survival. Hormone-replacement therapy will usually be unnecessary. However, the probability of major changes in libido and sexual performance should be discussed with patients so that additional stress can be avoided. Contraceptive advice should be available to those who require it.
Publication
Journal: Endocrinology
August/25/2008
Abstract
Estrogen, acting via estrogen receptor (ER)alpha, regulates serum gonadotropin levels and pituitary gonadotropin subunit expression. However, the cellular pathways mediating this regulation are unknown. ERalpha signals through classical estrogen response element (ERE)-dependent genomic as well as nonclassical ERE-independent genomic and nongenomic pathways. Using targeted mutagenesis in mice to disrupt ERalpha DNA binding activity, we previously demonstrated that ERE-independent signaling is sufficient to suppress serum LH levels. In this study, we examined the relative roles of ERE-dependent and -independent estrogen signaling in estrogen regulation of LH, FSH, prolactin, and activin/inhibin subunit gene expression, pituitary LH and FSH protein content, and serum FSH levels. ERE-independent signaling was not sufficient for estrogen to induce pituitary prolactin mRNA or suppress pituitary LHbeta mRNA, LH content, or serum FSH in estrogen-treated ovariectomized mice. However, ERE-independent signaling was sufficient to reduce pituitary glycoprotein hormone alpha-subunit, FSHbeta, and activin-betaB mRNA expression. Together with previous serum LH results, these findings suggest ERE-independent ERalpha signaling suppresses serum LH via reduced secretion, not synthesis. Additionally, ERE-dependent and ERE-independent ERalpha pathways may distinctly regulate steps involved in the synthesis and secretion of FSH.
Publication
Journal: Obstetrics and Gynecology
January/8/1985
Abstract
Eighteen postmenopausal women with severe hot flashes had continuous recordings of finger temperature and skin resistance as objective indexes of flushing episodes, and serial measurements of anterior pituitary hormones as indirect indexes of hypothalamic neurotransmitter activity. Significant increases of growth hormone, adrenocorticotropic hormone (ACTH), and luteinizing hormone (LH) occurred with maximal concentrations at 30, five, and 15 minutes, respectively, after the onset of the skin temperature rises. No significant fluctuations of prolactin (PRL), thyroid-stimulating hormone (TSH), or follicle-stimulating hormone (FSH) were observed. The mean serum cortisol concentration increased 15 minutes after the hot flash, presumably consequent to the preceding elevation of ACTH. Pituitary ACTH release may be secondary to hypothalamic cooling, whereas increased growth hormone and LH output and the thermoregulatory adjustments comprising the flushing episodes are all consistent with cyclic episodes of increased hypothalamic norepinephrine activity.
Publication
Journal: European Journal of Immunology
May/4/1983
Abstract
Rabbit anti-rat anti-human thyrotropin anti-idiotypic antibodies have been raised. These antibodies were active at the thyrotropin (TSH) receptor, in that they inhibited 125I-labeled bovine TSH binding to thyroid plasma membranes, stimulated adenylate cyclase activity through a guanyl nucleotide-dependent mechanism, augmented radioiodide transport into isolated porcine thyroid follicular cells and induced such cultured cells to organize into follicles. Aside from substantiating the expectation that anti-hormone anti-idiotypic antibodies may possess properties of the original hormone, this work raised the possibility that thyroid-stimulating antibodies which cause the hyperthyroidism of Graves' disease may be anti-TSH anti-idiotypic antibodies.
Publication
Journal: Endocrinology
January/4/2004
Abstract
The forkhead family of transcription factors is conserved in evolution and known to play critical roles in the regulation of cellular differentiation and proliferation in many systems. The current studies demonstrate for the first time that forkhead homolog in rhabdomyosarcoma (FKHR) (FoxO1a) is expressed in porcine granulosa cells, and FSH stimulates FKHR phosphorylation and regulates its subcellular localization in this system. RT-PCR and Western blot studies demonstrated that FKHR is expressed and showed no change in FKHR message or protein levels in response to FSH (0-6 h). However, [32p]-orthophosphate labeling of cultured granulosa cells revealed robust phosphorylation after FSH treatment for 30 min. In addition, FSH caused nuclear exclusion of FKHR in these cells, apparently through the phosphatidylinositol 3-kinase signal transduction pathway. The cytosolic accumulation of FKHR protein that was observed in FSH-treated cells both by Western blot and immunohistochemistry was blocked when the cells were preincubated with the phosphatidylinositol 3-kinase inhibitor LY294002. Our data also demonstrate that Akt/protein kinase B, an established kinase for FKHR, is phosphorylated in response to FSH treatment. Interestingly, although FKHR was phosphorylated by 30 min after FSH treatment, the time course for Akt phosphorylation was relatively delayed and sustained. Although these studies do not preclude Akt involvement in FSH-stimulated FKHR phosphorylation, they do suggest that other kinases may contribute to rapid signaling to FKHR. Because FKHR has been shown to activate genes involved in apoptosis and growth inhibition, FSH may promote growth and survival by initiating the phosphorylation of FKHR, causing its nuclear exclusion, and reducing its effect as a cell cycle arrest or death-promoting transcription factor.
Publication
Journal: Best practice & research. Clinical endocrinology & metabolism
July/4/2011
Abstract
The somatotropic axis is the central postnatal regulator of longitudinal growth. One of its major components--growth hormone--is produced by the anterior lobe of the pituitary, which also expresses and secretes five additional hormones (prolactin, thyroid stimulating hormone, follicle stimulating hormone, luteinizing hormone, adrenocorticotropic hormone). Proper development of the pituitary assures the regulation of critical processes such as metabolic control, puberty and reproduction, stress response and lactation. Ontogeny of the adenohypophysis is orchestrated by inputs from neighbouring tissues, cellular signalling molecules and transcription factors. Perturbation of expression or function of these factors has been implicated in the aetiology of combined pituitary hormone deficiency (CPHD). Mutations within the genes encoding for the transcription factors LHX3, LHX4, PROP1, and POU1F1 (PIT1) that act at different stages of pituitary development result in unique patterns of hormonal deficiencies reflecting their differential expression during organogenesis. In the case of LHX3 and LHX4 the phenotype may include extra-pituitary manifestations due to the function of these genes/proteins outside the pituitary gland. The remarkable variability in the clinical presentation of affected patients indicates the influence of the genetic background, environmental factors and possibly stochastic events. However, in the majority of CPHD cases the aetiology of this heterogeneous disease remains unexplained, which further suggests the involvement of additional genes. Identification of these factors might also help to close the gaps in our understanding of pituitary development, maintenance and function.
Publication
Journal: Fertility and Sterility
May/14/1997
Abstract
OBJECTIVE
To analyze the role of serum LH and of E2 secretion on IVF-ET outcome in patients stimulated with FSH.
METHODS
Using data from three studies, we analyzed ovarian response to FSH and IVF-ET outcome from two standpoints: [1] serum LH and [2] serum E2 on the day of hCG administration divided by the number of retrieved oocytes.
METHODS
Twenty-six academic and private clinical centers.
METHODS
Three hundred twenty-three ovulatory patients eligible for IVF-ET.
METHODS
Patients were treated with a GnRH agonist and FSH and underwent IVF-ET.
METHODS
Follicular development, embryos, and pregnancy rate (PR).
RESULTS
Serum LH levels did not correlate significantly with number of oocytes retrieved, E2-oocyte ratio, fertilization rate, or PR. Five patient subpopulations were identified on the basis of E2-oocyte ratios: 0 to 70 (A), 70 to 140 (B), 140 to 210 (C), 210 to 280 (D), and>> 280 (E) pg/mL per oocyte (conversion factor to SI unit, 3.671). Pregnancy rates were significantly different, i.e., 5.3%, 31.3%, 18.1%, 23.9%, and 20.4% for groups A, B, C, D, and E, respectively. Groups were not different in terms of baseline characteristics, number of follicles, fertilization rates, and number of embryos transferred.
CONCLUSIONS
Patients with very low levels of LH respond to FSH alone as well as those with higher LH. The E2-oocyte ratio is a strong index of success rate.
Publication
Journal: Stress
January/26/2003
Abstract
Despite extensive research, the mechanisms by which stress affects reproduction are unknown. Activation of stress systems could potentially influence reproduction at any level of the hypothalamo-pituitary gonadal axis. Nonetheless, the predominant impact is on the secretion of gonadotrophin releasing hormone (GnRH) from the brain and the secretion of the gonadotrophins, luteinizing hormone (LH) and follicle stimulating hormone (FSH), from the gonadotrophs of the anterior pituitary gland. When stress is prolonged, it is likely that secretion of the gonadotrophins will be suppressed but the effects of acute stress or repeated acute stress are not clear. Different stressors activate different pathways for varying durations, and the actions of stress vary with sex and are influenced by the predominance of particular sex steroids in the circulation. The mechanisms by which stress influences reproduction are likely to involve complex interactions between a number of central and peripheral pathways and may be different in males and females. To understand these mechanisms, it is important to determine the stress pathways that are activated by particular stressors and to establish how these pathways affect the secretion and actions of GnRH. Furthermore, there is a need to know how stress influences the feedback actions of gonadal steroids and inhibin.
Publication
Journal: Scandinavian Journal of Work, Environment and Health
March/6/1997
Abstract
OBJECTIVE
The purpose of this study was to describe hematopoietic and reproductive hazards of Korean electronic workers exposed to solvents containing 2-bromopropane.
METHODS
Detailed medical and occupational histories were taken and thorough physical examinations with clinical laboratory tests were done for 33 workers (8 men and 25 women). Previous and present exposure was investigated in detail by industrial hygienists.
RESULTS
Of the 25 female workers, 16 were shown to have secondary amenorrhea with high follicle-stimulating hormone levels, normal prolactin levels, and hot flashes. A total of eight workers with amenorrhea concurrently showed findings of pancytopenia. Among eight male workers, two showed azoospermia and another four showed some degree of oligospermia (normal>> 20 million. ml-1) or reduced sperm motility (normal>> 50%). The bone marrow effects and the testis or ovarian failure was shown to be the main health hazards in this workplace. Except for the cleaning solution containing 97.4% 2-bromopropane, no other known physical or chemical agents could be identified as responsible for the gonadal and bone marrow effects, including ionizing radiation, lead, ethylene glycol ether and its acetates, benzene, and dibromochloropropane.
CONCLUSIONS
No previous studies have reported human toxicity for 2-bromopropane, but the results of this study lead to the tentative conclusion that the causal agent for the gonadal and bone marrow effects among the workers might be 2-bromopropane.
Authors
Publication
Journal: Metabolism: Clinical and Experimental
May/7/1997
Abstract
Sixteen nondiabetic women with polycystic ovary syndrome (PCOS) aged 18 to 33 years were studied before and after 8 weeks on metformin (1.5 g/d) therapy to assess whether reducing hyperinsulinemia would reduce the levels of the major inhibitor of fibrinolysis, antigenic plasminogen activator inhibitor type 1 (PAI-1). Compared with six normal control women, PCOS women had a higher body mass index (BMI), waist to hip ratio, fasting insulin (Izero), insulin area under the curve during oral glucose tolerance testing (IA), glucose area under the curve during oral glucose tolerance testing (GA), IA/GA ratio, PAI-1, luteinizing hormone (LH) and ratio of LH to follicle-stimulating hormone (FSH), and free testosterone, and lower high-density lipoprotein (HDL) cholesterol (all P < .025). On metformin, BMI decreased 1.3% (P = .04), Izero 43% (P = .002), IA 31% (P = .03), GA 11% (P = .02), PAI-1 16% (P = .01), lipoprotein(a) [Lp(a)] 42% (P = .004), free testosterone 46% (P = .0006), LH 44% (P = .004), and the LH/FSH ratio 41% (P = .0001). On metformin, absolute and percent reductions in Izero correlated with absolute and percent reductions in PAI-1 (r = .60, P = .015 and r = .64, P = .008). On metformin, by stepwise multiple regression, the absolute reduction in Izero was a significant determinant of the absolute reduction in PAI-1 (partial R2 = 35%, P = .02), and the percent reduction in Izero was a significant determinant of the percent reduction in PAI-1 (partial R2 = 52%, P = .003). Metformin decreases Izero in hyperinsulinemic PCOS patients, reverses the hyperinsulinemia-driven endocrinopathy, decreases PAI-1, and decreases Lp(a), and should thus reduce the increased risk of atherothrombosis in PCOS.
Publication
Journal: Journal of Clinical Investigation
June/1/1972
Abstract
The interaction of the testis and gonadotropin secretion was studied in 15 men surviving chemotherapy for lymphoma. Azoospermia and complete destruction of all testicular germinal elements were present in 10 of the 15 men; however, Sertoli cells and Leydig cells were present. In these 10 men plasma follicle-stimulating hormone (FSH) levels were fourfold higher than in normal men of similar age whereas luteinizing hormone (LH) levels were normal. In contrast, both FSH and LH were normal in the remaining five men. Three had a full complement of spermatogenic tissue on biopsy and normal sperm concentrations. The other two men were azoospermic; one demonstrated full spermatogenesis in 30% of his tubules; the other had only a few spermatogonia in all tubules. In those patients with lower levels of gonadotropins pituitary insufficiency was excluded by the demonstration of appropriate responsiveness of FSH and LH to clomiphene administration. Similarly, Leydig cell function was normal since plasma testosterone was within the normal range in 13 of the 15 men and only slightly decreased in two. Thus, following chemotherapy, testicular damage was restricted to the germinal tissue, and this in turn was associated with a selective increase in FSH. The source of the FSH inhibitor is either the Sertoli cell or early germinal elements. However, since FSH levels are only half as high as those reported for castrate men, other testicular factors may modify FSH secretion.
Publication
Journal: Environmental Health Perspectives
March/1/2004
Abstract
There is experimental evidence of adverse effects of endosulfan on the male reproductive system, but there are no human data. Therefore, we undertook a study to examine the relationship between environmental endosulfan exposure and reproductive development in male children and adolescents. The study population was composed of 117 male schoolchildren (10-19 years of age) of a village situated at the foothills of cashew plantations, where endosulfan had been aerially sprayed for more than 20 years, and 90 comparable controls with no such exposure history. The study parameters included recording of clinical history, physical examination, sexual maturity rating (SMR) according to Tanner stages, and estimation of serum levels of testosterone, luteinizing hormone (LH), follicle-stimulating hormone, and endosulfan residues (70 study and 47 control subjects). Mean +/- SE serum endosulfan levels in the study group (7.47 +/- 1.19 ppb) were significantly higher (p < 0.001) than in controls (1.37 +/- 0.40 ppb). Multiple regression analysis showed that SMR scoring for development of pubic hair, testes, penis, and serum testosterone level was positively related to age and negatively related to aerial exposure to endosulfan (AEE; p < 0.01). Serum LH levels were significantly positively related to AEE after controlling for age (p < 0.01). The prevalence of congenital abnormalities related to testicular descent (congenital hydrocele, undescended testis, and congenital inguinal hernia) among study and controls subjects was 5.1% and 1.1%, respectively, but the differences were statistically nonsignificant. Our study results suggest that endosulfan exposure in male children may delay sexual maturity and interfere with sex hormone synthesis. Our study is limited by small sample size and nonparticipation.
Publication
Journal: Gynecological Endocrinology
March/10/2008
Abstract
BACKGROUND
Polycystic ovary syndrome (PCOS) is often characterized by chronic oligo- or anovulation (usually manifested as oligo- or amenorrhea), and hyperandrogenism. In addition, 30-40% of PCOS women have impaired glucose tolerance, and a defect in the insulin signaling pathway (inositol-containing phosphoglycan mediators) seems to be implicated in the pathogenesis of insulin resistance. PCOS patients are subfertile as a consequence of such ovulatory disorders and often need drugs, such as clomiphene citrate or follicle-stimulating hormone, for ovulation induction, which increases the risk of multiple pregnancy and ovarian hyperstimulation syndrome. We hypothesized that the administration of an isoform of inositol (myo-inositol), belonging to the vitamin B complex, would improve the insulin-receptor activity, restoring normal ovulatory function.
METHODS
Twenty-five PCOS women of childbearing age with oligo- or amenorrhea were enrolled in the study. Ovulatory disorder due to PCOS was apparently the only cause of infertility; no tubal defect or deficiency of male semen parameters was found. Myo-inositol combined with folic acid (Inofolic) 2 g twice a day was administered continuously. During an observation period of 6 months, ovulatory activity was monitored with ultrasound scan and hormonal profile, and the numbers of spontaneous menstrual cycles and eventually pregnancies were assessed.
RESULTS
Twenty-two out of the 25 (88%) patients restored at least one spontaneous menstrual cycle during treatment, of whom 18 (72%) maintained normal ovulatory activity during the follow-up period. A total of 10 singleton pregnancies (40% of patients) were obtained. Nine clinical pregnancies were assessed with fetal heart beat at ultrasound scan. Two pregnancies evolved in spontaneous abortion.
CONCLUSIONS
Myo-inositol is a simple and safe treatment that is capable of restoring spontaneous ovarian activity and consequently fertility in most patients with PCOS. This therapy did not cause multiple pregnancy.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
May/8/2003
Abstract
To test the hypothesis that estradiol, inhibin A, and inhibin B contribute differentially to FSH negative feedback in specific phases of the menstrual cycle, daily blood samples were obtained across a control cycle and after selective estrogen blockade with tamoxifen. To examine the site of estradiol-negative feedback in control and tamoxifen treatment cycles, early follicular phase GnRH (free alpha-subunit) pulse frequency was assessed in normal women, and FSH levels were examined in GnRH-deficient women in whom hypothalamic output was fixed with GnRH administration. FSH was higher in the early follicular phase in the presence of estrogen receptor blockade (15.7 +/- 3.1 vs. 13.2 +/- 1.9 IU/liter; P < 0.05) but was not increased in the late follicular phase. In the luteal phase, FSH was elevated (10.1 +/- 0.7 vs. 7.3 +/- 0.6 IU/liter; P < 0.01). In normal women, free alpha-subunit pulse frequency increased (7.3 +/- 0.4 vs. 4.8 +/- 0.4 pulses per 8 h; P < 0.003), but in GnRH-deficient women, there was no FSH increase (11.1 +/- 1.6 vs. 12.5 +/- 3.6 IU/liter) in the early follicular phase in the presence of estrogen blockade. In conclusion, estradiol exerts a greater role over inhibin in FSH-negative feedback regulation during the luteal phase and the luteal-follicular transition. In contrast, inhibin A and/or B plays a more critical role as the follicular phase progresses. In addition, these studies support a primary if not exclusive hypothalamic site of estrogen-negative feedback in the early follicular phase.
Publication
Journal: Menopause
January/13/2010
Abstract
OBJECTIVE
The aim of this study was to estimate the probabilities and identify risk factors for entering the menopausal transition and moving into each subsequent transition stage.
METHODS
Estimations of probabilities of entry into each menopausal transition stage and predictors associated with each transition stage were conducted in a population-based cohort of midlife women.
RESULTS
The likelihood of entering the menopausal transition and moving into each subsequent stage was increased for each unit increase in follicle-stimulating hormone (FSH) (P < 0.001) and with each unit decrease in inhibin B (P < 0.001) in the adjusted multivariable model. The largest observed change in average FSH levels was the comparison of women in the late transition (stage 4), with an average of 24.78 mIU/mL, to those in the early transition (stage 3), with 10.38 mIU/mL. Women experiencing this amount of change in FSH had an odds of transitioning from stages 3 to 4 of 1.90 (95% CI, 1.86-1.95). Decreases in inhibin B resulted in odds ratios similar to the magnitude of changes in FSH. Current smoking increased the odds of transition into each stage by approximately 30% (odds ratio, 1.30; 95% CI, 1.28-1.32). Average estradiol levels did not change dramatically between stages. However, higher estradiol significantly increased the odds of entering the transition (P = 0.013). Age and race predicted transitions into some but not all stages. Body mass index, alcohol use, and age at menarche did not predict entrance into any stage of the menopausal transition after adjusting for other study variables.
CONCLUSIONS
These results show that increased FSH, decreased inhibin B, and smoking strongly predict entry into the earliest stages of the menopausal transition as defined by changes in bleeding patterns. African Americans entered the transition before white women, but race did not predict entry into late transition stages. Higher estradiol levels predict entry into the earliest transition stage but not subsequent stages.
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