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Coronavirus disease 2019 (COVID-19) is a new infectious respiratory disease that has caused the ongoing global pandemic. The primary purpose of this article is to describe evolving clinical epidemiology of COVID-19, including 1) infection and testing, 2) clinical spectrum including classification of clinical type, asymptomatic cases, severe cases and comorbidity, and clinical and immunological response, 3) regional variation in clinical presentation, 4) population distribution by age, sex, and occupation, and finally, 5) case-fatality. This content may provide important information on detailed clinical type and presentation of the disease, in which appropriate clinical outcomes can be derived for developing prevention strategies and clinical studies or trials that aim to test potential therapeutics or products for different patient populations.

Background: Both genetic and epidemiological studies have indicated that environmental factors play an essential role in the development of autism spectrum disorder (ASD). We conducted this study to identify maternal exposure to environmental factors, in particular during the fetal development or perinatal period, associated with ASD. Methods: Two independent samples of children with ASD and typical developed (TD) were from distinct regions in China. Multiple logistic regression analysis was performed to identify factors associated with ASD in each sample and then in the combined sample. Results: Five factors were consistently associated with ASD in both samples. In the combined sample, maternal chemical exposure (odds ratio [OR] =4.50; 95% CI: 2.38-8.52), use of medication (OR = 3.19; 95% CI: 2.19-4.65), maternal infection (OR = 2.68; 95% CI: 1.99-3.61), threatened abortion (OR = 2.37; 95% CI: 1.61-3.50), and induced abortion before having the child (OR = 2.07; 95% CI: 1.65-2.60) showed strong associations with ASD; moreover, five factors explained 10-15% of the variation in the risk of ASD. A significant interaction between maternal infection and the use of medication during pregnancy was consistently detected in both independent and combined samples together. Conclusion: Two novel risk factors of maternal chemical exposure and induced abortion may have important implications for understanding the etiology of ASD, particularly in China. Prospective studies are needed to validate these findings, and necessary interventions are recommended to reduce the risk of ASD. KEYWORDS Autism spectrum disorder, chemical exposure, induced abortion, maternal infection

Background: Gastroschisis has increased globally over recent decades and this increase is not explained by demographic changes in maternal age. Implicated risk factors for this increase include lifestyle behaviors, environmental exposures, low-er socioeconomic status, lower body mass index, poor nutrition, smoking tobacco, using illicit drugs, alcohol, or analgesics and genitourinary infections. Methods: Selective review of the literature. Results: Present hypotheses would only suggest avoidance of suspect exposures as protective interventions. To identify safe and efficacious protective therapies, new cellular/molecular modes-of-action need to be considered. Plausible develop-mental modes-of-action include a) changes in epigenetic programming of relevant stem or progenitor cells; b) mechanical forces (cellular mechanosensitivity and mechanotransduction) signaling; and c) ephrin–Eph receptor multimodal signali-ng. These developmental modes-of-action present plausible options for “druggable” molecules that could be developed into protective or mitigative therapeutic agents for gastroschisis. Conclusion: Possible interventions for modifiable factors in gastroschisis include 1) Delay childbearing. 2) Improve nutri-tion for younger gravidas. 3) Pre-conceptional counseling to reduce embryonic exposures to the range of implicated lifest-yle, environmental and medical factors. 4) Urge research colleagues to investigate the cellular and molecular mechanisms underlying gastroschisis and to translate those insights into one or more safe and efficacious preventive or mitigative thera-pies.

Transparency in reporting the results of clinical and preclinical research is critical for unbiased publications. Funding agencies, publishers, and regulators have the responsibility to advocate and implement reporting standards for rigorous design. While individual study protocols may have included these standards, the items reported in the respective publications have often been inconsistent or lack transparency. This editorial intends to provide some specific guidelines for reporting results of clinical research with standards required for rigorous study design. We recommend that reporting clinical research should include sufficient information on study design and analysis plan that contains data processing, quality assurance, and appropriate methods used for rigorous statistical analysis or modeling. Any discrepancy between publications and original study design should be disclosed and discussed. Additionally, recent advances in the analysis of outcome with repeated measurements and statistical modeling should be employed to obtain unbiased estimates. Finally, we briefly discuss some issues reporting real-world evidence in clinical research.

The neonatal hormone environment influences the sexually differentiated patterns of development. Estrogens, derived from intracerebral aromatization, promote male pattern development of the central nervous system. The purpose of this study was to determine the effects of neonatal exposure to environmental estrogens on luteinizing hormone (LH) secretion and development of the sexually dimorphic nucleus of the medial preoptic area (SDN-POA) in castrated adult rats. Neonatal rats of both sexes received injections of either corn oil, 0.1 microgram diethylstilbestrol (DES), 3 micrograms beta-sitosterol (B1), 30 micrograms beta-sitosterol (B2), 0.1 microgram coumestrol (C1), 1 microgram coumestrol (C2), or 10 micrograms coumestrol (C3) on Day 1-10 of life and were castrated on Day 21. Right heart catheters were placed on Day 42, and GnRH (50 ng/kg) was administered. Blood was sampled for LH at 0-, 5-, 10-, 15-, and 30-min intervals. All doses of beta-sitosterol and coumestrol elicited increased basal levels of LH in females. In males, B1, B2, C2, and C3 increased basal levels of LH. The GnRH-induced LH increase was prevented in females treated with diethylstilbestrol and 10 micrograms of coumestrol. Males in all treatment groups exhibited GnRH-induced LH surges. The animals were sacrificed by decapitation on Day 49. Volumes of the SDN-POA of the groups were compared. Treatment with the agents did not result in significantly increased SDN volume in females; nor was there a difference in SDN size among the male groups. These data show that exposure to environmental estrogens early in development alters both postpubertal pituitary response to GnRH and basal LH secretion in females and alters only basal LH secretion in males. No significant enlargement (i.e., masculinization) of the SDN-POA was exhibited.

Since presentation of our view of translational developmental toxicology in 2013, numerous investigations from a wide range of approaches have added to the evidence underlying our core premise; namely that as the potential adverse developmental effects from a range of exposures are progressively defined, preventative or mitigative therapies can be conceived, assessed and ethically implemented. The spectrum of studies reported in recent years span a wide range of exposure categories and various developmental outcomes ranging from molecular and cellular to the organismal level up to and including human behavior. Since human exposures to chemicals, physical agents and social factors are inevitable, the human fetus is subject to effects that can have lifelong consequences. In order to apply the translational concept to developmental toxicology, established or potential therapeutic obstetrical, neonatal, childhood and adolescent interventions will be required. Those that undergo testing during developmentally sensitive intervals will likely derive from generally-regarded-as-safe (GRAS) or well-established/repurposed pharmaceutical options. Ultimately if we are to translate environmental health discoveries into safe and effective interventions, we must assert and characterize valid, applicable therapies such as GRAS treatments and eventually “ethical pharmaceuticals” for the protective care of these highly vulnerable young people. We can create a safe and efficacious environmental health portfolio of interventional options to improve human health that include both reduction/avoidance of exposure and specific preventative/mitigative/restorative therapeutics. In this chapter we will broadly update new insights that have been gained over the last 2 years regarding the progress of translational developmental toxicology toward becoming a therapeutic discipline.

Background: The association of DDT (dichlorodiphenyltrichloroethane) with breast cancer is controversial, but animal studies directly linking DDT to risk are lacking. Concerns with DDT reside in its environmental persistence, bioaccumulation in breast adipose tissue, and endocrine-disrupting actions. Whereas most attention has been focused on estrogenic congeners, we tested the cancer-inducing potential of the antiandrogen, p,p´-DDE [1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene], the most prevalent and persistent DDT metabolite. Objectives: We aimed to determine whether developmental exposure to p,p´-DDE stored in adipose tissue surrounding the cancer-prone mammary epithelium of MMTV-Neu mice influences tumor development. Methods: For localized delivery, Elvax 40P pellets containing p,p´-DDE were implanted into the mammary fat pads of prepubertal female mice. We compared mammary tumor development with p,p´-DDE with development in response to its estrogenic isomer, o,p´-DDE [1,1-dichloro-2-(o-chlorophenyl)-2-(p-chlorophenyl) ethylene], and a mixture of both isomers. Results: p,p´-DDE implants significantly accelerated mammary tumor onset compared with vehicle Elvax implants. o,p´-DDE had similar results, but only at ≤ 10 months of age. Lipid-adjusted levels of p,p´-DDE in mammary adipose tissue and serum in young mice were within the ranges of human exposure, whereas concentrations in aged mice were low to undetectable. Exposure to a 2:1 ratio of p,p´-DDE:o,p´-DDE did not result in the younger latency observed with the individual isomers. Conclusions: p,p´-DDE exposure at concentrations relevant to human exposure accelerates mammary carcinogenesis in mice, possibly through hormonal and/or other actions. These data suggest that DDE exposure would promote, but not cause, mammary tumorigenesis. Developmental exposure in immature mammary tissue continues to affect tumor onset even after p,p´-DDE levels have declined. Future studies are needed to determine whether early exposure to p,p´-DDE correspondingly predisposes women to early-onset breast cancer.

Ovarian hormones regulate pituitary gonadotropin secretion across the menstrual cycle via negative and positive feedback mechanisms. The contribution of individual hormones is complex and is a continuing area of research.The aim of the study was to identify relationships between LH/FSH and estradiol, progesterone, inhibin A, inhibin B, and anti-Mullerian hormone (AMH) in ovulatory menstrual cycles across reproductive age.Serum ovarian and pituitary hormones were studied in a group of young (35 yr; n = 21) and older (45 yr; n = 55) women. The slopes of the regression lines relating the ovarian and pituitary hormones were determined by multiple linear regression analysis and expressed with 95% confidence intervals for each ovarian hormone, with FSH and LH as independent variables. Both simultaneous and delayed (time lagged) relationships were examined.Clear associations were evident for the lagged prediction of FSH, with significant negative associations being evident with inhibin B and AMH in the follicular phase and with estradiol, inhibin B, progesterone, and AMH in the luteal phase. For the lagged prediction of LH, significant positive and negative associations were observed with estradiol and inhibin B, respectively, in the follicular phase and a negative association with progesterone and inhibin B in the luteal phase.It is concluded that in the follicular phase, inhibin B is a major feedback regulator of FSH and may also be a negative feedback regulator of LH. AMH may be indirectly involved in FSH regulation.

To date, the endocrine changes accompanying female reproductive aging have been quite variable and unpredictable. The first standardized guidelines were drawn up at the Stages of Reproductive Aging Workshop (STRAW) in 2001. The present investigators attempted to describe comprehensively the endocrinological features associated with STRAW stages. Healthy women 21-35 and 45-55 years of age submitted 3 blood samples each week during a single menstrual cycle. The 21 younger women served as mid-reproductive age (MRA) controls with regular menstrual cycles. The 56 older women were classified at STRAW stage 3, late reproductive age (LRA) with regular cycles (n = 16); STRAW stage 2, early menopause transition (EMT) with cycles of varying length (n = 17); and STRAW stage 1, late menopause transition (LMT) with at least 1 intermenstrual interval of 60 days or longer (n = 23). The numbers of anovulatory cycles were 9, 1, 0, and 2, respectively, in the LMT, EMT, LRA, and MRA groups. Ovulatory-cycle levels of follicle-stimulating hormone (FSH), luteinizing hormone, and estradiol all increased with the progression of STRAW stage. Mean luteal-phase levels of serum progesterone declined. Early-cycle (ovulatory and anovulatory) levels of inhibin B declined steadily across STRAW stages, and it was largely undetectable during elongated ovulatory and anovulatory cycles in the menopausal transition. Levels of anti-Mullerian hormone decreased markedly by as much as 15-fold across the STRAW stages. These findings, although not conclusive, suggest that both inhibin B and anti-Mullerian hormone may be preferable to FSH for predicting STRAW stage with respect to the onset and progression of the menopausal transition.

The National Toxicology Program (NTP) and the National Institute of Environmental Health Sciences (NIEHS) established the NTP Center for the Evaluation of Risks to Human Reproduction (CERHR) in June 1998. The purpose of CERHR is to provide timely, unbiased, scientifically sound evaluations of human and experimental evidence for adverse effects on reproduction and development caused by agents to which humans may be exposed. Hydroxyurea was selected for evaluation by a CERHR expert panel because of (1) its increasing use in the treatment of sickle cell disease in children and adults, (2) knowledge that it inhibits DNA synthesis and is cytotoxic, and (3) published evidence of its reproductive and developmental toxicity in rodents. Hydroxyurea is FDA-approved for reducing the frequency of painful crises and the need for blood transfusions in adults with sickle cell anemia who experience recurrent moderate-to-severe crises. Hydroxyurea is used in the treatment of cancer, sickle cell disease, and thalassemia. It is the only treatment for sickle cell disease aside from blood transfusion used in children. Hydroxyurea may be used in the treatment of children and adults with sickle cell disease for an extended period of time or for repeated cycles of therapy. Treatment with hydroxyurea may bemore » associated with cytotoxic and myelosuppressive effects, and hydroxyurea is mutagenic.« less

In addition to estrogen dependence, endometriosis is characterized by chronic pelvic inflammation. The impact of the chronic pelvic inflammatory state on other organ systems and women’s health is unclear. Endometriosis associated chronic inflammation and potential adverse health effects across the lifespan render it imperative for renewed research vigor into the identification of novel biomarkers of disease and therapeutic options. Herein we propose a number of opportunities for research and development of new therapeutics to address the unmet needs in the treatment of endometriosisper seand its ancillary risks for other diseases in women across the lifespan.

This study determined the impact of breastfeeding on hypoestrogenic symptoms among women in the postpartum period and correlated these findings with the Estrogen Threshold Hypothesis, which postulates that the hypoestrogenic symptoms experienced are related to circulating estrogen levels.Using a survey instrument that combined previously validated assessments of postpartum mood changes and menopausal symptoms, women were evaluated in the immediate postpartum period, prior to hospital discharge, and at 3 and 6 weeks postpartum. Each time period was analyzed independently, in a cross-sectional design, where women were categorized as "breastfeeding" or "bottle feeding."Of 236 women recruited, 171 (72.5%) intended to breastfeed, and 62 (26.3%) intended to bottle feed. At both the 3- and 6-week postpartum evaluations, a similar percentage of women in the breastfeeding and bottle-feeding groups reported hot flashes. However, breastfeeding women were more likely to report vaginal dryness than those who did not breastfeed: 20/150 (13.3%) versus 3/80 (3.8%) at 3 weeks, p0.05; 25/143 (17.5%) versus 2/87 (2.3%) at 6 weeks, p0.001.The Estrogen Threshold Hypothesis accurately predicts the findings of increased reported vaginal dryness but not hot flashes during lactation.

Ovarian endometriomas are a common manifestation of endometriosis that can represent a more severe stage of the disease. There is much debate over the treatment of these cysts in infertile women, particularly before use of assisted reproductive technologies. Evidence exists that supports surgical excision of ovarian endometriomas, as well as evidence that cautions against surgical intervention. Certain factors need to be examined closely before proceeding with surgery or continuing with expectant management. These include the patient’s symptoms, age, ovarian reserve, size and laterality of the cyst, prior surgical treatment, and level of suspicion for malignancy. The most recent evidence appears to suggest that certain patient profiles may benefit from proceeding directly to in vitro fertilization (IVF). These include symptomatic infertile patients, especially those that are older, those that have diminished ovarian reserve, those that have bilateral endometriomas, or those that have had prior surgical treatment. Although endometriomas can be detrimental to the ovarian reserve, surgical therapy may further lower a woman’s ovarian reserve. Nevertheless, the presence of an endometrioma does not appear to adversely affect IVF outcomes, and surgical excision of endometriomas does not appear to improve IVF outcomes. Regardless of treatment plan, infertile patients with endometriomas must be counseled appropriately before choosing either treatment path.

A panel convened by the Harvard Center for Risk Analysis (HCRA) evaluated the weight of evidence for potential developmental and reproductive toxicity of bisphenol A (BPA, CASRN 80-05-7) in animals at doses well below the Lowest Observed Adverse Effect Level (LOAEL) of 50 mg/kg-day previously identified by the U.S. Environmental Protection Agency (US EPA) and even US EPA's reference dose (RfD) of 0.05 mg/kg-day. The effects are hypothesized to occur through an endocrine-modulating mode of action, specifically through estrogen receptors. The panel focused on potential male reproductive effects but also examined other endpoints possibly associated with hormone-like effects. The review considered studies published through April 2002. A formal deliberation framework focused on consistency, generalizability, and biological plausibility. The panel found no consistent affirmative evidence of low-dose BPA effects for any endpoint. Inconsistent responses across rodent species and strains made generalizabi...

The human population in the industrialized world is ubiquitously exposed to complex mixtures of persistent pollutants that contaminate food, water, and air. A large number of these contaminants have been shown to cause significant toxicity to the hypothalamic-pituitary-thyroid (HPT) axis in laboratory animal studies, through a variety of mechanisms, although these effects occur at levels of exposure greatly in excess of common human exposure. While many of the mechanisms of thyroid toxicity of these substances are potentially complementary, little is known of the degree of interaction of common persistent contaminants on responses of the HPT axis. To investigate the potential effects of a complex, environmentally relevant mixture on the HPT axis, sexually mature male rats were administered a mixture of 16 common organochlorines (dichlorodiphenoxytrichloroethane [DDT], p,p'-dichlorodiphenoxydichloroethylene [p,p'-DDE], hexachlorobenzene [HCB], tetrachlorodibenzo-p-dioxin [TCDD], polychlorinated biphenyls [PCBs], methoxychlor, endosulfan, heptachlor, hexachlorocyclohexane, dieldrin, aldrin, mirex, and several chlorinated benzenes, and metal contaminants [lead, cadmium]). The doses of the mixture that were administered were related to minimum risk levels or tolerable daily intakes of these substances, as derived by risk assessment with the 1x, 10x, 100x, and 1000x groups receiving mixture components at doses equivalent to 1x, 10x, 100x, or 1000x the minimum risk level (or tolerable daily intake, reference dose), respectively. After 70 daily treatments by gavage, endpoints related to circulating thyroid hormone (serum thyroxine [T(4)], triiodothyronine [T(3)], thyroid stimulating hormone [TSH], and serum T(3) uptake [T(3)-up]), thyroid gland histomorphology (thyroid follicle cross sectional area, epithelial height, follicle roundness or aspect ratio, colloid/epithelial ratio) and hepatic metabolism of thyroid hormone (UDP-glucuronyl transferase [UGT] and outer-ring deiodinase [ORD]) were assessed. All examined endpoints were significantly altered by the mixture albeit with great variability between endpoints in the sensitivity. While most endpoints examined did not show significant changes at mixture doses below 1000x, 2 endpoints, TSH and hepatic outer ring deiodinase activity, were significantly increased and decreased, respectively, by 1x dose and showed dose-related increases in severity with increasing dose. Median thyroid follicle cross sectional area was also increased by the lowest dose of the mixture but decreased with subsequent increases in dose until, at the highest dose, this parameter was significantly reduced relative to control. The relative sensitivity of endpoints of thyroid function in detecting toxicity of the mixture was TSH = ORD = median follicle area >> T(3) > all other endpoints. These results demonstrate that low doses of ubiquitous environmental contaminants can alter HPT physiology in sexually mature males.

BACKGROUND Oral contraceptive (OC) use is associated with a reduced risk of ovarian cancer. An OC component, progestin, induces apoptosis in the primate ovarian epithelium. One regulator of apoptosis is transforming growth factor-beta (TGF-beta). We determined the effect of progestin on TGF-beta expression in the primate ovarian epithelium and examined the relationship between TGF-beta expression and apoptosis. METHODS Female cynomolgus macaques were randomly assigned to receive a diet for 35 months containing no hormones (n = 20); the OC Triphasil (n = 17); or each of its constituents, ethinyl estradiol (estrogen, n = 20) or levonorgestrel (progestin, n = 18 ), alone. Ovarian sections were immunostained with monoclonal antibodies against TGF-beta1 or TGF-beta2 plus TGF-beta3 (TGF-beta2/3) isoforms. The expression of TGF-beta isoforms in four ovarian compartments (epithelium, oocytes, granulosa cells, and hilar vascular endothelium) was compared among treatment groups. The association between TGF-beta expression and apoptosis, as determined by morphology and histochemistry, was examined in ovarian epithelium. All statistical tests were two-sided. RESULTS Compared with ovaries from the control and estrogen-only-treated monkeys, the ovaries of progestin-treated monkeys showed 1) a marked decrease in the expression of TGF-beta1 and a concomitant increase in the expression of the TGF-beta2/3 isoforms in the ovarian epithelium (P

If endocrine active chemicals (EACs) adversely affect human development, then there must be evidence of effects in animal models at properly scaled levels of exposure during pertinent sensitive periods as derived from quantified exposures of the human fetus. Our recent studies attempt to address both effects and exposures. First Study: Dams were gavaged from Gestation Day (GD) 14 through weaning on Post-Natal Day (PND) 21 with either corn oil alone (unexposed controls) or Low DES (0.5 mg/kg BW); High DES (5.0 mg/kg BW); GEN (15 mg/kg BW); GEN + DES (GEN at 15 mg/kg BW and DES at 0.5 mg/kg BW). No treatments affected duration of gestation, litter size or birth anogenital distance / birth body weights ((bAGD/bBW) or ratios of bAGD/cube root of bBW of pups of either sex. The ratio of weaning AGD to weaning body weight (wAGD/wBW) differed significantly between the control group and each of the estrogenic treatments in both sexes with larger wAGD/wBW values associated with each of the estrogenic treatments. Ma...

Oral contraceptive (OC) therapy has long been known to produce hypoandrogenemia. However, androgens are not part of any OC therapy available to women. This project was designed to evaluate the effects of low-estradiol containing OC, with or without methyltestosterone (MT), on cell proliferation and progesterone receptor (PgR) expression in mammary gland epithelia of virgin female rats. Sixty rats were divided into four groups. One group received OCs, whereas a second group received OC plus MT. A third group of rats was treated with an antiandrogen to mimic the hypoandrogenemic effects caused by OC therapy. All treated groups were compared with age-matched untreated controls. After 15 weeks of treatment, no inflammatory, precancerous, or cancerous lesions were observed in any treatment group. OC plus MT therapy caused significant suppression of epithelial proliferation, a reduction in the number of proliferating cell nuclear antigen-labeled cells, and an increase in the number of PgR-labeled cells. Our results suggest that a medication containing an estrogen-progestin-androgen combination has antiproliferative effects in mammary glands of experimental animals that could prove to have breast-protective potential in women.

OBJECTIVE The apoptosis pathway is a vital mechanism in vivo that functions to eradicate genetically damaged cells prone to malignancy. The purpose of this study was to determine whether oral contraceptives, which confer significant protection against subsequent epithelial ovarian cancer, induce apoptosis in the ovarian epithelium. METHODS Female cynomolgus macaques (N = 75) were randomized to receive a diet for 35 months containing either no hormones, the oral contraceptive Triphasil (Wyeth-Ayerst Laboratories, Philadelphia, PA), the estrogenic component of Triphasil (ethinyl estradiol) alone, or the progestin component of Triphasil (levonorgestrel) alone, each administered in a cyclic fashion. At study termination, the animals underwent ovariectomy and the ovarian epithelium was examined morphologically and immunohistochemically for apoptosis. The percentage of ovarian epithelial cells undergoing apoptosis was measured in each animal and compared between the treatment groups. RESULTS The median percentage of ovarian epithelial cells undergoing apoptosis by treatment was control (3.8%), ethinyl estradiol (1.8%), Triphasil (14.5%), and levonorgestrel (24.9%). Compared with control and ethinyl estradiol-treated monkeys, a statistically significant increase in the proportion of apoptotic cells was noted in the ovarian epithelium of monkeys treated with the oral contraceptive Triphasil (P < or = .01) or levonorgestrel (P < .001), with a maximal effect (six-fold) seen in the group treated with levonorgestrel alone. CONCLUSION Oral contraceptive progestin induces apoptosis in the ovarian epithelium. Given the importance of the apoptosis pathway for cancer prevention, an effective chemopreventive strategy may be possible using progestins or other agents that selectively induce apoptosis in the ovarian epithelium to prevent the development of ovarian cancer.

Mathematical models of the hypothalamus-pituitary-ovarian axis in women were first developed by Schlosser and Selgrade in 1999, with subsequent models of Harris-Clark et al. (Bull. Math. Biol. 65(1):157–173, 2003) and Pasteur and Selgrade (Understanding the dynamics of biological systems: lessons learned from integrative systems biology, Springer, London, pp. 38–58, 2011). These models produce periodic in-silico representation of luteinizing hormone (LH), follicle stimulating hormone (FSH), estradiol (E2), progesterone (P4), inhibin A (InhA), and inhibin B (InhB). Polycystic ovarian syndrome (PCOS), a leading cause of cycle irregularities, is seen as primarily a hyper-androgenic disorder. Therefore, including androgens into the model is necessary to produce simulations relevant to women with PCOS. Because testosterone (T) is the dominant female androgen, we focus our efforts on modeling pituitary feedback and inter-ovarian follicular growth properties as functions of circulating total T levels. Optimized parameters simultaneously simulate LH, FSH, E2, P4, InhA, and InhB levels of Welt et al. (J. Clin. Endocrinol. Metab. 84(1):105–111, 1999) and total T levels of Sinha-Hikim et al. (J. Clin. Endocrinol. Metab. 83(4):1312–1318, 1998). The resulting model is a system of 16 ordinary differential equations, with at least one stable periodic solution. Maciel et al. (J. Clin. Endocrinol. Metab. 89(11):5321–5327, 2004) hypothesized that retarded early follicle growth resulting in “stockpiling” of preantral follicles contributes to PCOS etiology. We present our investigations of this hypothesis and show that varying a follicular growth parameter produces preantral stockpiling and a period-doubling cascade resulting in apparent chaotic menstrual cycle behavior. The new model may allow investigators to study possible interventions returning acyclic patients to regular cycles and guide developments of individualized treatments for PCOS patients.

Contemporary translational biomedical research strives to move from discoveries in models (in silico, in vitro and in vivo) into human clinical trials to expeditiously develop specific therapeutics. Translational toxicology must similarly strive to identify applicable therapeutics that can safely and effectively mitigate potential harm from exposures. Since human exposures to chemicals, physical agents and social factors are inevitable, the human fetus is subject to effects that can have lifelong consequences. In order to apply the translational concept to developmental toxicology, we are guided by the modest number of established and accepted obstetrical therapeutics used primarily for fetal benefit. These established or potential therapeutic obstetrical interventions suggest that early steps into testing or implementing developmental translational toxicology therapies during the in utero and early neonatal period will likely derive from Generally-Recognized-As-Safe (GRAS) options. If we are to translate environmental health discoveries into safe and effective interventions, we must assert and characterize valid, applicable therapies such as GRAS treatments and eventually “ethical pharmaceuticals” for the protective care of these highly vulnerable young patients. We can create a safe and efficacious environmental health portfolio of interventional options to improve human health that include both reduction/avoidance of exposure and specific preventative/mitigative/restorative therapeutics.

Many edible plants contain natural estrogens called phytoestrogens. These compounds possess mixed estrogen agonist-antagonist properties that are organ-specific in vivo. We have focused on estrogenic soybean isoflavones because of their potential extensive dietary availability. In this article, we review the clinical and experimental evidence for the possible benefits and risks of ingestion of estrogenic isoflavones throughout the life span, and highlight areas needing further elucidation.

Exposure to naturally occurring estrogens during critical periods of development can alter morphologic and physiologic markers of sexual differentiation. The current experiment characterizes the effects of in utero treatment with genistein, an isoflavonoid phytoestrogen, on birth weight, anogenital distance (AGD) at birth. GnRH stimulated luteinizing hormone (LH) secretion, volume of the sexually dimorphic nucleus in the preoptic area of the hypothalamus (SDN-POA), puberty onset, and vaginal cyclicity. Pregnant Charles River CD rats were injected sc daily on gestation day 16-20 with either 25,000 micrograms genistein (G25), 5,000 micrograms genistein (G5), 5 micrograms diethylstillbestrol (DES), 50 micrograms estradiol benzoate (E), or corn oil alone for controls. Birth weights and anogenital distance was taken and exposed progeny were subsequently used in two experiments. In Experiment 1 intra-atrial catheters were placed in adult castrated rats, GnRH was given iv, serial blood samples were drawn and sera were assayed for LH by radioimmunoassay (RIA). Brains obtained by subsequent decapitation were saved for histology. In Experiment 2, females were monitored for timing of vaginal opening as a marker of puberty onset, and vaginal smears were taken to monitor cyclicity. G25-treated females and DES- and E-treated animals of both sexes had decreased weights at birth compared with controls. G5- and E-treated animals of both sexes and DES males had smaller AGD than controls. No significant differences in pituitary responsiveness to GnRH were found among treatment groups. There was a nonsignificant decrease in SDN-POA volume in G5-treated females while DES- and E-treated females had increased SDN-POA volume compared with controls. G5-treated females had delayed puberty onset, and DES-treated females had atypical vaginal cycles in comparison with controls. The results confirm that prenatal exposure to estrogens in the environment can influence sexual differentiation. Our previous experiments have demonstrated that castrate female rats exposed as neonates to genistein have decreased pituitary responsiveness to GnRH challenge and enlarged SDN-POA volume in comparison with controls. Prenatal genistein at these dosages did not significantly alter these markers. However, genistein did mimic other estrogens' effects on AGD and birth weight and had a unique influence on puberty onset. Not only are genistein's effects different from other estrogens, but dosage and timing of exposure during development appear to be important factors in genistein's ability to modify these end points.

The estrogen receptor α (ERα) splicing variant with an in-frame deletion of exon 3 (ERΔ3) is frequently expressed in the normal breast, but its influence on tumorigenesis has not been explored. In vitro, ERΔ3 has dominant negative activity, suggesting it may suppress estrogen stimulation in the breast. ERΔ3 may inhibit classical signaling on estrogen response element (ERE)-regulated genes as well as activate non-classical pathways at Sp1 and AP-1 sites. Transgenic mice were developed that express mouse ERΔ3 in all tissues examined, including the mammary gland. To investigate if ERΔ3 expression affects tumorigenesis, ERΔ3 mice were crossbred with MMTV-Neu mice. Mammary tumor onset was significantly delayed in ERΔ3/Neu versus MMTV-Neu females and metastatic incidence and burden was significantly reduced. Consequently, ERΔ3 expression suppressed tumor development and metastasis in this aggressive model of HER2/Neu-positive breast cancer. To determine if ER ligands with anticancer activity may augment ERΔ3 protection, the bitransgenic mice were treated with tamoxifen and soy isoflavones starting at age 2 months. Soy protein with isoflavones (181 mg/1,800 kcal) did not affect tumor development in MMTV-Neu or ERΔ3/Neu mice; however, metastatic progression was not inhibited in soy-treated ERΔ3/Neu mice, as it was in untreated ERΔ3/Neu mice. In contrast, tamoxifen (20 mg/1,800 kcal) significantly enhanced tumor prevention in ERΔ3/Neu versus MMTV-Neu mice (98 % vs. 81 % tumor free). The results in ERΔ3/Neu mice demonstrate that ERΔ3 influences estrogen-dependent mammary carcinogenesis and, thus, may be protective in women expressing ERΔ3 in the breast. However, exposure to different estrogens may augment or block its beneficial effects.

Objective To test the hypothesis that high galactose consumption and low activity of galactose-1-phosphate uridyl transferase (transferase) is associated with early ovarian senescence among nongalactosemic women. Design Cross-sectional study. Data collection consisted of a self-administered questionnaire with sections on diet (food frequency data to measure galactose consumption), reproductive, and medical histories. One blood sample was collected to measure FSH and transferase activity; FSH was used as a measure of ovarian senescence. Among women who were having menstrual periods at least every 8weeks, the blood sample was drawn in the early follicular phase (days 2 to 4) of a menstrual cycle. Participants Two hundred ninety-five women volunteers ages 38 to 49years who had not had a hysterectomy or oophorectomy were recruited through posters and advertisements. Main Outcome Measure Serum FSH concentrations. Results Controlling for age, smoking, and body mass, transferase activity and FSH were unrelated. However, FSH levels were 29% higher (95% confidence intervals, 9% to 52%) among women who reported consuming ≥6g galactose/d. Conclusion These data do not support the hypothesis that low transferase activity represents a genetic predisposition for early ovarian senescence, as measured by FSH levels in women ages 38 to 49years. However, the hypothesized positive association between galactose consumption and FSH was supported.

Quantification of exposure to environmental contaminants such as endocrine active chemicals (EACs) during critical periods of development, particularly in utero, remains largely unexplored. Therefore, we tested the hypothesis that EACs can be detected and quantified in second trimester human amniotic fluid. Amniotic fluid was obtained from women (n=175) undergoing routine amniocentesis between 14 and 21 weeks gestation. Samples were assayed by gas chromatography/mass spectrometry (GC/MS) for common organochlorine contaminants and dietary phytoestrogens. The DDT metabolite p,p'-DDE was found in approximately 25% of amniotic fluid samples (mean±S.D., 0.15±0.06 ng/ml) whereas the dietary phytoestrogens, genistein and or daidzein were found in 96.2% of samples tested (0.94±0.91 and 1.08±0.91 ng/ml, respectively). Our results demonstrate that: (1) human amniotic fluid is a suitable biological medium to evaluate developmental exposure to EACs, and (2) fetuses are exposed to biologically active levels of EACs in mid pregnancy.

Objective To determine the predictive value of preovulatory serum concentrations of P, E 2 , and LH for pregnancy achieved with IUI after superovulation with and without adjunctive leuprolide acetate (LA) therapy. Design Randomized, crossover study of superovulation with and without LA therapy. Setting Infertility clinic. Patients Subfertile patients referred for superovulation and IUI. Main Outcome Measures Preovulatory serum concentrations of P, E 2 , and LH on the day of hCG administration; pregnancy. Results Preovulatory serum concentrations of P, E 2 , and LH had equivalent predictive value for pregnancy during cycles stimulated without LA therapy. No single parameter was particularly useful in clinical decision making. Threshold P concentrations proposed in other studies as useful in predicting pregnancy did not correlate with cycle fecundity. The predictive value of preovulatory concentrations of P during superovulation with adjunctive LA therapy was significantly worse than P concentrations during superovulation without LA therapy. Conclusions Preovulatory serum P, E 2 , and LH concentrations in superovulation and IUI are not helpful in determining prognosis for pregnancy. The relative utility of predictive parameters may vary for different treatment regimens.

The effects of neonatal diethylstilbestrol (DES) exposure on the volume of the sexually dimorphic nucleus of the preoptic area of the hypothalamus (SDN-POA) and on GnRH-stimulated LH secretion were investigated in castrated female rats of known anogenital distance (AGD) at birth. The AGD was measured in females on the day of birth, and 0.1 μg DES or corn oil was injected from Days 1 through 10 of life. The volume of the SDN-POA was significantly larger in animals that had received DES than in those that had received corn oil. The largest SDN-POA volumes were seen in DES-treated animals that had long (>1.4 mm) AGDs, and the smallest volumes in corn oil-treated females that had short (≤1.4 mm) AGDs

Neonatal diethylstilbestrol (DES) exposure diminishes pituitary responsiveness to GnRH in castrated postpubertal rats 4 h after placement of intra-atrial cannulae under ketamine anesthesia. Ketamine anesthesia has been reported to blunt the preovulatory LH surge in female rats and to decrease baseline LH levels in males immediately following administration, although its effect lasted less than 2 h. It is not known what impact ketamine has on baseline LH levels or on GnRH-stimulated LH release in estrogen-exposed castrated rats. This study was designed to determine 1) whether the changes in GnRH-induced LH secretion in DES-exposed castrated rats are partially attributable to a direct effect of ketamine; 2) the gender-specific effects of ketamine on LH secretion; and 3) the DES-dependent effects of ketamine on LH secretion. In this experiment we ascertained the effect of ketamine anesthesia for right heart cannulation on LH levels in male and female 42-day-old castrated rats that were exposed to either corn oil or DES (0.1 jpg/day) on Days 1 through 10 of life. LH secretion in DES-exposed animals increased, in contrast to that in control animals, immediately (< 10 min) after anesthesia and cannulation. Mean LH levels in DES-exposed females were lower than in controls before GnRH administration and were blunted following GnRH. While ketamine and catheterization were associated with decreased LH titer in males, the extent of that decrease was not dependent on exposure to DES. Both sexes and exposure groups achieved baseline catheter LH values by 4 h. This experiment demonstrates that 1) the pituitary response to ketamine anesthesia and catheterization depends on gender and neonatal DES exposure and 2) the previously reported decreases in GnRH-induced LH secretion due to neonatal treatment with DES cannot be attributed to ketamine-induced suppression of basal gonadotropin secretion.

Estrogen exposure during critical periods of development promotes androgenization of the brain, which is reflected in altered morphology, behavior, and cyclic hormone secretion in females. Previous work in our laboratory demonstrated that neonatal female rats injected with pharmaceutical or naturally occurring estrogens had decreased GnRH-induced LH secretion and increased volume of the SDN-POA as 42 day castrates. The current experiment defines the dose-response characteristics of neonatal exposure to the isoflavonoid phytoestrogen genistein (G) on pituitary sensitivity to GnRH and SDN-POA volume. Litters of rat pups received subcutaneous injections of either corn oil, 1, 10, 100, 200, 400, 500, or 1000 micrograms of G on days 1 to 10 of life. The litters were ovariectomized and weaned on day 21. On day 42 blood was drawn from right atrial catheters immediately prior to, 5, 10, 15, and 30 min following a single injection of 50 ng/kg of GnRH. Only the 10 micrograms dose of G was associated with increased pituitary response to GnRH, while progressive increases in exposure levels of G were associated with decreasing LH secretion. The SDN-POA volume was increased in only the 500 micrograms and 1000 micrograms exposure groups compared to controls. The results confirm that low doses of G have nonandrogenizing, pituitary-sensitizing effects, while higher doses of G mimic the more typical effects of estrogens. The use of both morphologic and physiologic end points more completely defines the reproductive consequences of environmental estrogen exposure during critical periods of CNS development.

Lactoferrin (LTF), an iron-binding glycoprotein present in most exocrine secretions and in the secondary granules of polymorphonuclear leucocytes (PMN), is regulated by estrogen in the mouse reproductive tract. We investigated the expression of LTF mRNA and protein during the natural estrous cycle to increase our understanding of how this uterine secretory protein is regulated under physiological conditions. There was a positive correlation between LTF mRNA expression in the genital tract and serum estradiol (E2) concentrations. When E2 peaked in proestrus, LTF mRNA and protein were expressed in the uterus; however, during metestrus, when both E2 and progesterone levels were high, LTF mRNA was expressed, while LTF protein was decreasing. LTF protein expression may be hindered by progesterone or some other local factor in the endometrial epithelium after ovulation. Immunohistochemistry demonstrated two distinct staining patterns for LTF in the vaginal and endometrial epithelium. In one staining pattern, the colorimetric reaction was noted over the cytoplasm, and in the other, the nuclear region stained more intensely. This suggests the possibility that in addition to its known role as a secretory protein, LTF may be transported to the nucleus, serving an autocrine role. Our results also indicated that LTF protein is a useful marker for tracking PMN. Nonproliferating epithelial cells in the vagina and endometrium may synthesize chemotactic and/or adhesion molecules for PMN.

The neonatal hormone environment determines the sexually differentiated pattern of brain growth. Estrogens, derived from intracerebral aromatization of testosterone, promote male sexual central nervous system (CNS) development. Developing animals may also encounter estrogens from plant, fungal, and xenobiotic sources (environmental estrogens). The purpose of this study was to assess the effects of environmental estrogens on the physiology and morphology of the hypothalamus and pituitary. Neonatal rats received injections of either corn oil, 0.1 microgram diethylstilbestrol (DES), 100 micrograms genistein (G100), 1000 micrograms genistein (G1000), 100 micrograms zearalenone (Z100), or 1000 micrograms zearalenone (Z1000) on Days 1-10 of life and were castrated on Day 21. On Day 42, right heart catheters were placed, GnRH (50 ng/kg) was administered, and blood was sampled for LH at 0, 5, 10, 15, and 30 min. Females exposed neonatally to DES, G1000, Z100, and Z1000 showed significantly decreased pituitary responsiveness to GnRH, whereas G100 increased GnRH-induced LH secretion. Males exposed neonatally to G100 also showed increased pituitary response to GnRH, and the remaining estrogen-exposed groups of males exhibited either decreased tonic LH or attenuated GnRH-stimulated LH secretion. The animals were killed by decapitation on Day 49. Volumes of the sexually dimorphic nucleus of the preoptic area (SDN-POA) of the exposed groups were compared. In females, DES, G1000, and Z1000 increased SDN volume; Z100 and G100 had no effect. There was no difference in SDN size among the male groups. These data show that exposure to environmental estrogens early in development alters postpubertal pituitary response to GnRH and "androgenizes" the SDN-POA.

The endocrine function of the ovary after menopause is perhaps less well understood than at any other time in the female life cycle. To evaluate the hormonal function of the ovary further at this stage of life, reproductive hormone levels were measured in 11 postmenopausal women admitted to the gynecologic oncology service for pelvic surgery which would involve bilateral oophorectomy. Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels, along with estradiol, testosterone, dehydroepiandrosterone sulfate (DHEA-S), and androstenedione levels, were measured preoperatively, on Postoperative Days 1 and 4, and at 6 weeks following surgery. Testosterone and androstenedione levels fell by half in these patients, whereas estradiol levels were unaffected. LH and FSH showed a fall in the immediate postoperative period, with a subsequent return to baseline levels by 6 weeks after surgery. DHEA-S levels were unaffected by surgery. There are no discernible differences in subjective menopausal symptoms postoperatively in postmenopausal women undergoing bilateral oophorectomy compared to their preoperative state. The data show that the long-held but inadequately proven thesis that postmenopausal oophorectomy dramatically reduces androgen levels is in fact true. This is further evidence that the postmenopausal ovary is an important source of potent and potentially aromatizable androgens.

An assessment battery including standardized measures of behavioral and psychosocial factors associated with other chronic pain conditions was administered to 102 women scheduled for laparoscopic surgery. Surgeons who were blinded to the patient's self-reported pain data completed the American Fertility Society classification for endometriosis and adhesions on the basis of observed physical disease. Although American Fertility Society classification scores were significantly related to self-assignment into pain or no-pain groups, the extent of physical disease evaluated by this procedure was not significantly correlated with ratings of pain levels or a number of indexes of impairment. The group of patients with laparoscopically diagnosed pathologic conditions reported higher pain levels and greater interference than the group who reported pain and had negative laparoscopic results; however, some women with observable pathologic conditions reported no pain symptoms.

The menopausal transition is characterized by irregular menstrual cycles and unpredictable hormone levels, including dramatic swings in estradiol (E2). An increasing number of studies have found variable high E2 and low luteal phase progesterone occur with progression of Stages of Reproductive Aging Workshop (STRAW)stage, but the cause remains unclear. To explore the causes of the erratic changes in E2, individual within-cycle secretion patterns of E2, progesterone, follicle-stimulating hormone, luteinizing hormone, inhibin A, and inhibin B were explored in detail.Blood samples taken three times per week over 1 1/3 menstrual cycles from 77 women aged 21 to 55 classified as mid-reproductive age (STRAW stages 5 and 4; n = 21), late-reproductive age (STRAW stages 4 and 3; n = 16), early menopausal transition (STRAW stage 2; n = 17), and late menopausal transition (STRAW stage 1; n = 23) were analyzed.Eleven of the 29 (37%) early and late menstrual transition ovulatory cycles exhibited a specific pattern of E2 secretion that was characterized by a second increase in E2 during the mid- and late luteal phases and that continued to a peak during the subsequent menstrual phase. This second rise and fall in E2 was typical in appearance of a normal follicular phase, except that it was superimposed on an existing ovulatory cycle(specifically during the luteal and menstrual phases). The pattern was therefore referred to as a luteal out-of-phase(LOOP) follicular event. In four of these LOOP cycles, a luteinizing hormone peak and ovulatory episode followed the second E2 peak early in the subsequent cycle. Compared with the typical ovulatory cycles, the cycles with LOOP events exhibited lower luteal phase progesterone, higher early cycle follicle-stimulating hormone, and lower early cycle inhibin B. They were also associated with abnormally short (21 d) or long (40 d) cycle length.Many of the marked increases in ovulatory cycle E2 and cycle irregularities during the menopausal transition may be due to LOOP events and appear to be triggered by prolonged high follicular phase follicle-stimulating hormone levels.

To characterize menstrual cycles in women in late reproductive age and the menopause transition, based on changes in serum hormone levels.Serum levels of estradiol, progesterone, follicle-stimulating hormone (FSH), luteinizing hormone, inhibin A, inhibin B, and antimüllerian hormone, as previously reported as mean data grouped according to the Stages of Reproductive Aging Workshop proposals, were analyzed in 55 women aged 45 to 55 and compared with those in 21 women aged 21 to 35.The ovulatory cycles in the older women were divided into three types. Type 1 cycles (n = 14, 33%) were those with hormone concentrations similar to the women aged 21 to 35 except for 20-fold lower antimüllerian hormone levels. Type 2 cycles (n = 24; 53%) had increased FSH, decreased inhibin B, and increased FSH-to-inhibin B ratios but normal estradiol and progesterone levels. Type 3 cycles had the same characteristics as type 2 cycles (n = 5; 12%) in addition to lower luteal phase progesterone and increased luteinizing hormone.The changes in hormone levels indicated in cycle types 1 to 3 closely reflect the changes in ovarian-pituitary activity as menopause approaches and are likely to be directly attributable to a decrease in ovarian follicle reserve. The findings suggest that FSH-to-inhibin B ratios and antimüllerian hormone are distinct early indicators of the menopause transition and are likely to be useful biomarkers of impending menopause. Furthermore, this classification may provide an improved basis for the study of reproductive endocrine disorders associated with the menopause transition.

Little data exist on the effects of adjunctive therapy with leuprolide acetate (LA) in the luteal phase of women with polycystic ovary syndrome (PCOS) undergoing ovulation induction with human menopausal gonadotropin (hMG). Additionally, it is not known whether gonadal steroid concentrations in the luteal phase of induced cycles in PCOS are predictive of pregnancy. In this prospective, randomized study comparing cycles using hMG alone (n=26) with cycles using hMG with LA (n=33), no differences were noted between treatment groups in progesterone (P), estradiol (E 2 ), and P:E 2 ratios on luteal days 3, 6, and 9. When all treatment cycles were pooled, there were no differences in P, E 2 , or P:E 2 ratios, comparing conception and nonconception cycles. We conclude that adjunctive therapy with LA in PCOS patients undergoing ovulation induction with hMG does not alter the luteal phase concentrations of P, E 2 , and P:E 2 . Furthermore, no correlation was found between the serum concentrations of these luteal phase steroids and cycle fecundity.

In this special issue, we have secured a series of insightful articles from experts in this field of research and care to address endometriosis from a broad and longitudinal perspective. Specifically, this special issue brings forward several articles with novel insights into the pathogenesis of endometriosis and addressing the state-of-the-art in clinical markers of endometriosis. We think this collection of papers will help focus attention on how the adverse health impacts of endometriosis often compromise our patients in diverse ways for years to decades of their lives. The cumulative impact of endometriosis on the health of women across the lifespan can be parsed into two sets of issues, namely, those of (1) assessment and treatment of the pelvic/intraperitoneal compartment and (2) potentially systemic more remote risks, in terms of location (other tissues/organs) and time in the lifespan. As the guest editors for this special issue, we offer a plea to you, our colleagues. Endometriosis is indeed a disease with unique pathophysiology but can we please abandon use of terms implying that it is a disease of deep “enigmatic” mystery? We know that it is a subchronic to chronic predominantly intraperitoneal, often progressive and destructive, inflammatory disease that has a massive impact on the health of many postpubertal women. Given the known role of chronic inflammation as a prominent factor in the occurrence of numerous other diseases, we must determine the extent to which this process in the intraperitoneal compartment does or does not “spill over” into systemic inflammation that creates broader health risks. It is only with a comprehensive perspective that we can develop and implement a coherent strategy for care of those who suffer from endometriosis. “It is our view that there are ample opportunities to pursue research regarding the impact of endometriosis across the lifespan and to pursue development of a number of therapeutics that could plausibly be expected to be both safe and beneficial for women suffering with this disease. This is not an argument for taking our eye off the prize meaning endometriosis as the primary disease; rather we owe it to each of our patients to consider all of the impacts at all times in life that this disease may incur. We urge deeper and broader understanding of such risks and pursuit of safe and effective interventions for the care of our patients” [1]. Claude L. Hughes Warren G. Foster Sanjay K. Agarwal Liselotte Mettler

Our commentary describing the extensive new literature reporting low-dose effects of bisphenol A (BPA) in experimental animals (vom Saal and Hughes 2005) was written in response to a report from the Harvard Center for Risk Analysis (HCRA) by Gray et al. (2004), who concluded that “the weight of the evidence for low-dose effects [of BPA] is very weak.” The HCRA report was funded by the American Plastics Council and involved a selective review of only 19 of a much larger number of studies that could have been reviewed. In our commentary we showed that a comprehensive review of the now extensive literature concerning studies in experimental animals that used doses of BPA within the range of human exposure led to exactly the opposite conclusion from that reached in the HCRA report (Gray et al. 2004), which was released 2.5 years after it was written. At this time there are only two published epidemiologic studies showing a relationship between blood levels of BPA and diseases in humans. In his letter, Politch focuses his attention on a single study by Takeuchi et al. (2004) that describes a relationship between BPA in blood and polycystic ovary disease (PCOS) in Japanese women. In a second recently published article, Sugiura-Ogasawara et al. (2005) reported a relationship between blood levels of BPA and recurrent miscarriage in Japanese women. Politch seeks to deflect attention from the central issue of our review by focusing only on the study by Takeuchi et al. (2004) and stating that such studies “cannot address causal relationships” and suggesting that “appropriately controlled” human studies are required. We are certain that readers of Environmental Health Perspectives (EHP) realize that these are criticisms that can be directed at all epidemiologic studies, which can never achieve the control required in laboratory experiments. Additionally, there is always some risk in arguing the methodologic details of a peer-reviewed publication in one field of scientific research (epidemiology) when the commentator’s core expertise (biopsychology) lies elsewhere. Most importantly, based on his criticism of the levels of BPA reported in the blood of women by Takeuchi et al. (2004), Politch appears to be unaware of the large literature concerning the levels of BPA in human blood, urine, and tissues from studies conducted in different regions of the world reporting virtually identical mean and/or median values. For example, in a recent study at the Centers for Disease Control and Prevention, Calafat et al. (2005) found BPA in 95% of the human urine samples they assayed—in the same range reported in human blood in other studies (e.g., Schonfelder et al. 2002; Tan and Mohd 2003). All of this published literature is listed in a document available on the University of Missouri Endocrine Disruptor web site (Endocrine Disruptors Group 2005). One point-of-view expressed by Politch that we strongly support is the proposition that human studies linking developmental exposure with adult disease are also required, based on the extensive evidence that the developing fetus and neonate are the most vulnerable to endocrine disruption. We hope that the planned National Children’s Study will address this issue and begin to characterize which exposures are and are not consequential for human health. In the absence of such a study, which will take decades to complete, we rely on experimental studies in animals to make decisions regarding the potential hazards posed by chemicals. Our comment that the epidemiologic evidence “adds to our concern” about the potential hazards posed to humans by BPA hardly qualifies as justification for the criticism that we “overstated the importance” of this or any other single study. Our concern about the potential hazards of BPA to humans is justified by the fact that the limited epidemiologic studies do follow and generally support findings from over 125 experiments with laboratory animals showing that low doses of BPA cause adverse effects on a wide range of outcomes. We also pointed out in our article (vom Saal and Hughes 2005) that 100% of the studies showing significant effects of BPA in laboratory animals were funded by government agencies, and 100% of the studies funded by chemical corporations conclude that the same low doses of BPA do not cause significant effects. What is crucial in relation to the critique by Politch is that the two epidemiologic studies relating BPA in blood to diseases in women are consistent with the findings from studies of the hazards of BPA in animals at doses that lead to blood levels in animals within and below those detected in human blood.

Young women with galactosemia experience ovarian failure at a very early age raising concern about the ovarian toxicity of galactose. While galactose may be present in the diet as a monosaccharide, it is predominantly derived from cleavage of the disaccharide lactose within the intestine. Our previous studies in animals have shown that high galactose diets inhibit ovarian follicular development and long-term exposure to high lactose diets retards growth of rats. The objective of the present study was to determine whether galactose exposure in the form of dietary lactose mimics the effects found previously with diets rich in galactose. Sixty female Long-Evans rats (25-day-old) were randomly assigned to two groups and fed a control diet (41.9% glucose in AIN93G [American Institute of Nutrition], CON) before lactose treatment. Unilateral ovariectomy (uOVX) was performed on half of the rats in each group to determine baseline ovarian follicle numbers. The study diet was a high lactose diet (HLD) containing 41.9% lactose in AIN93G. Study diet exposure started 1 month after uOVX (3 months old) and continued for 7 months in the treatment group. The control group remained on the 41.9% glucose diet throughout. Vaginal cytology, ovarian morphometric analyses, and serum concentrations of estradiol and progesterone were examined. Long-term exposure to the HLD decreased the body weights of animals and progesterone concentrations in the serum but produced no harmful effects on ovarian morphology or function. Beginning at 5 months of age (two months of lactose treatment) increasing numbers of females began to cycle irregularly but there was no difference between the glucose and lactose diet groups. These negative findings imply that administration of galactose in the form of lactose seems to be much less toxic than when galactose is fed to animals. From a human health perspective, these results are somewhat reassuring, since in general, women eat lactose-containing foods rather than foods that contain large amounts of free galactose.

Clinical evidence suggests an association between galactosemia and premature ovarian failure, but the mechanism is still not fully understood. Growth differentiation factor-9 (GDF-9) is thought to be an obligatory growth factor during the gonadotropin-independent phase of folliculogenesis. The objective of this study was to examine the effects of galactose on initiation of folliculogenesis in the peripubertal interval and the connection between galactose toxicity and GDF-9 expression in the ovary. After immature Long-Evans rats (n = 10) were fed a diet consisting of 20% galactose for 19 days, whole body, ovary and uterine weights were measured. Serum estradiol and progesterone concentrations were measured by radioimmunoassay. Ovarian follicles were counted by morphometric analysis and GDF-9 expression was investigated by immunohistochemistry and immunoblot assay. Galactose treatment did not affect the onset of puberty as marked by the time of vaginal opening. The galactose diet significantly decreased the number of healthy growing follicles. The results of immunoblot assay showed that both bands corresponding to propeptide and mature forms of GDF-9 decreased with the galactose diet about 90 and 70%, respectively. The results of immunohistochemical staining showed that the GDF-9 positive follicle number and the ratio of GDF-9 positive to GDF negative (primordial/non-growing) follicles significantly decreased with this high galactose diet. The present study suggests that a high galactose diet inhibits follicular development, possibly through down-regulation of GDF-9 in the rat ovary, implying that GDF-9 may be involved in galactose-related ovarian toxicity.

Objective Developmental exposure to dioxin-like compounds has been associated with cognitive and motor impairments in children. These toxicants have been shown to be thyroid toxicants in animal studies. Therefore, the objective of this study was to quantify the overall dioxin-like activity in maternal serum and determine the association between dioxin-like activity and thyroid hormone levels. Study design Cross-sectional examination of serum from pregnant women (n = 150) attending a prenatal diagnosis clinic between January 2002 and December 2003. Results Serum dioxin-like activity was measured in 145 of 150 (96.7%) maternal serum samples. The mean (± SEM) serum lipid-adjusted dioxin-like activity was 0.34 ± 0.01 pg/g. Multiple regression analysis failed to demonstrate a relationship between maternal serum dioxin-like activity and serum thyroid hormone levels. Conclusion Dioxin-like activity is quantifiable in an overwhelming majority of second-trimester maternal serum samples but there was no relationship between dioxin-like activity and thyroid hormone levels in our study population.

Reproductive and developmental disorders are significant public health problems, with implications for the public in terms of both quality of life issues and economic costs. Congress passed a law i...

As an outgrowth of our interest in the potential toxicity of dietary galactose, we investigated the metabolic effects of high lactose diets in Long-Evans female rats. Seventy-five Long-Evans female rats (25-day-old) were randomized to receive one of 3 diets for 7 months: glucose diet (CON); low lactose diet (10.5%, LLD); or a high lactose diet (41.9%, HLD). Necropsy was performed seven months after randomization. HLD animals had significantly lower body weights than controls (P < 0.01). These animals continued to grow, however at a retarded rate compared to the CON group. The HLD group also had significantly lower triglyceride and non-esterified fatty acid levels than the CON group (P < 0.01 and P < 0.05). Serum glucose concentrations were lower in the HLD group compared to CON animals (P < 0.05), while serum insulin levels were lower than both the LLD and CON animals (P < 0.01 and P < 0.05). Leptin exhibited a similar trend. Thyroid studies revealed no difference in TSH between groups. Free T4 was significantly higher in HLD rats compared to LLD and CON rats while free T3 was lower in the HLD group (P < 0.05). This indicates a possible impairment in T4 to T3 conversion. Our data suggests that a long-term high lactose diet is associated with a decrease in insulin and leptin levels, and an increase in the insulin to glucose ratio. However, these changes are seen in the presence of a decreased body mass. A significant effect on thyroid hormone metabolism is also seen, and may be an adaptive mechanism in lactose-fed rats.

In a related reproductive toxicology study designed to investigate the effects of in utero exposure to environmental toxicants and potential interaction with postnatal genistein, gross enlargement of thoracic mammary glands was observed in female offspring at 200 days of age. Therefore, the objective of this study was to analyze the effect of in utero exposure to a mixture of toxicants on mammary gland morphology. Time-mated Sprague-Dawley rats were treated on days 9-16 of gestation with vehicle or a mixture of environmental toxicants at 1x the acceptable daily intake. Furthermore, it is unclear whether postnatal exposure to phytoestrogens in soy formulas poses breast cancer benefit or risk, and potential interactions with environmental toxicants are unknown. Therefore, half the female pups from each treatment group received either subcutaneous vehicle or genistein (10 microg/g body weight [bw]/day) on postnatal days 2-8. Following necropsy at 200 days of age, a pathologist, blinded to treatment groups, examined mammary gland histopathology. Only mild histological changes were found in mammary glands of rats exposed to the mixture in utero while pronounced ductal hyperplasia, lactational changes, and fibrosis were observed in mammary glands from the genistein group and were more prominent in the mixture + genistein group. Mammary glands of the control group were histologically normal. Collectively, our results reveal that postnatal exposure to pharmacological levels of genistein induces profound morphological changes in the mammary glands of adult female rats, and that high levels of phytoestrogens possess the potential to modulate the toxicological effects of toxicant mixtures.

Soy has received attention as an alternative to conventional hormone replacement therapy (HRT) largely because it is a unique dietary source of isoflavones. Isoflavones are diphenolic compounds that have both hormonal and nonhormonal properties and are considered to be selective estrogen receptor modulators. The estrogen-like effects of isoflavones in combination with the low reported frequency of hot flushes in Japan has prompted investigation of the effect of soy on menopausal symptoms. The purpose of this review is to evaluate the efficacy of soyfoods and isoflavone supplements for the alleviation of hot flushes. Nineteen trials (13 using a parallel design) involving more than 1,700 women were identified. Six trials were excluded from analysis: two that involved breast cancer patients, two that reported data on severity but not hot flush frequency, one that was not blinded, and one that did not include a control group. Based on a simple regression analysis of the remaining data set (13 trials), there was a statistically significant relationship (P =.01) between initial hot flush frequency and treatment efficacy. Initial hot flush frequency explained about 46% of the treatment effects, and hot flush frequency decreased by about 5% (above placebo or control effects) for every additional initial hot flush per day in women whose initial hot flush frequency was five or more per day. Although conclusions based on this analysis should be considered tentative, the available data justify the recommendation that patients with frequent hot flushes consider trying soyfoods or isoflavone supplements for the alleviation of their symptoms.

The human diet contains numerous endocrine-active compounds that influence mammalian physiology. The effects of these dietary compounds may be mediated by interaction with well-characterized intracellular hormone receptors or by other effects on patterns of endogenous hormone production, metabolism, target tissue signaling, growth, or differentiation. Because humans evolved as omnivores, the spectrum of dietary compounds that can be tolerated at modest levels of intake without frank toxicity is broad. Modest intake of these diverse nonnutritive endocrine-active compounds offers potential human health benefits through modulation of metabolic and hormonal responses, especially in sedentary individuals consuming a highly refined diet.

Human populations throughout the world are exposed daily to low levels of environmental contaminants. The consequences of potential interactions of these compounds to human endocrine, reproductive, and immune function remain unknown. The current study examines the effects of subchronic oral exposure to a complex mixture of ubiquitous persistent environmental contaminants that have been quantified in human reproductive tissues. The dosing solution used in this study contained organochlorines (2,3,7,8-tetrachlorodibenzo-p-dioxin [TCDD], polychlorinated biphenyls [PCBs],p,p'-dichlorodiphenoxydichloroethylene [p,p'-DDE],p,p-dichlorodiphenoxytrichloroethane [p,p'-DDT], dieldrin, endosulfan, methoxychlor, hexachlorobenzene, and other chlorinated benzenes, hexachlorocyclohexane, mirex and heptachlor) as well as metals (lead and cadmium). Each chemical was included in the mixture at the minimum risk level (MRL) or tolerable daily intake (TDI) as determined by the U.S. EPA or ATSDR or, for TCDD, at the no observable effect level (NOEL) used to calculate the TDI. Sexually mature male rats were exposed to this complex mixture at 1, 10, 100, and 1000 times the estimated safe levels daily for 70 days. On day 71, all animals were sacrificed and a variety of physiological systems assessed for toxic effects. Evidence of hepatotoxicity was seen in the significant enlargement of the liver in the 1000x group, reduced serum LDH activity (100x), and increased serum cholesterol and protein levels (both 1000x). Hepatic EROD activities were elevated in animals exposed to10x and above. The mixture caused decreased proliferation of splenic T cells at the highest dose and had a biphasic effect on natural killer cell lytic activity with an initial increase in activity at 1x followed by a decrease to below control levels in response to 1000x. No treatment-related effects were seen on bone marrow micronuclei, daily sperm production, serum LH, FSH, or prolactin levels or weights of most organs of the reproductive tract. The weights of the whole epididymis and of the caput epididymis were significantly decreased at 10x and higher doses, although no effect was seen on cauda epididymal weight. The sperm content of the cauda epididymis was increased at the 1x level but not significantly different from control at higher dose levels. A slight, but significant, increase in the relative numbers of spermatids was seen in the animals from the 1000x group with a trend towards reduced proportion of diploid cells at the same dose. Only minor, nondose related changes were seen in parameters related to condensation of chromatin, as determined by flow cytometry, in epididymal sperm. We conclude that the mixture induced effects on the liver and kidney and on general metabolism at high doses but caused only minor effects on immune function, reproductive hormone levels, or general indices of reproductive function measures. These data suggest that additive or synergistic effects of exposure to contaminants resulting in residue levels representative of contemporary human tissue levels are unlikely to result in adverse effects on immune function or reproductive physiology in male rats.