Estrogen therapy in postmenopausal women: effects on cognitive function and dementia

Estrogen and cognitive functioning in women

Research in basic neuroscience has provided biological plausibility for the hypothesis that estrogen replacement therapy (ERT) would protect against cognitive aging in healthy women. The weight of the evidence from randomized controlled trials of estrogen and cognition in women shows that this hormone preferentially protects verbal memory in postmenopausal women, whereas findings from observational studies are less consistent and show a more diffuse effect of estrogen on a range of cognitive functions. There is fairly consistent evidence from epidemiological studies that ERT significantly reduces the risk of Alzheimer's disease (AD) in women. On the other hand, findings from controlled treatment trials of women diagnosed with probable AD failed to show that physiological doses of ERT ameliorate existing deficits in cognitive functioning and/or prevent further deterioration in memory that inevitably occurs in these women over time. Finally, an accumulating body of evidence is beginning to suggest that the immediate postmenopausal period may constitute a critical window for treatment with ERT that maximizes its potential to protect against cognitive decline with aging and/or to reduce the risk of AD.

Effects of hormone replacement therapy on perceptual and cognitive event-related potentials in menopausal insomnia

The influence of a combined estrogen-progestin regimen (Climodien, Lafamme) on auditory event-related potentials (ERPs) was investigated in a double-blind, placebo-controlled, comparative, randomized 3-arm trial phase (Climodien 2/3=estradiol valerate 2 mg+the progestin dienogest 3 mg, EV=estradiol valerate 2 mg, and placebo), followed by an open-label phase in which all patients received Climodien 2/2 (estradiol valerate 2 mg+dienogest 2 mg). Both the double-blind and the open-label phase lasted 2 months. ERPs were recorded from 19 EEG leads in a two-tone odd-ball paradigm in 49 patients aged between 46 and 67 yr with the diagnosis of insomnia (G 47.0) related to postmenopausal syndrome (N 95.1). Climodien reduced standard N1 and target P300 latencies as compared to placebo, while EV did not affect N1 latency but similarly reduced P300 latency. Climodien increased N1, P2 and P300 amplitudes dose-dependently, predominantly at frontal leads. Estrogen alone had only minor effects on ERP amplitudes. The shortening of standard N1 latency and enhancement of N1 and P2 amplitudes indicates a positive effect of Climodien on perceptual processing, most likely due to vigilance improvements also observed in EEG mapping. Concerning target P300, it seems that estradiol is responsible for the improvement in stimulus evaluation time, as reflected by the shortening of the peak latency, while dienogest seems to account for the improvement in cognitive information processing capacity, whereby 3 mg induced a more pronounced augmentation of P300 amplitudes than 2 mg. Based on the spatial distribution of this increase, it can be speculated that Climodien mainly affects the more frontally distributed P3a subcomponent, which is associated with attention and orientation. Furthermore, the observed changes in ERP-components are consistent with recent studies showing significant positive effects of hormone replacement therapy on cholinergic functions. Thus, Climodien seems to be of interest in preventing cognitive decline and treating cognitive disorders in postmenopausal women. Indeed, there is increasing evidence of beneficial effects of estrogen in dementia. Our present findings suggest that the estrogen effects may be augmented by dienogest.

The menopause and HRT. HRT and cognitive decline

It is biologically plausible that hormone replacement therapy (HRT) would be protective against cognitive decline and Alzheimer's disease (AD). We review observational and randomized trials to determine whether HRT might protect against cognitive decline in cognitively unimpaired and demented women. We also address issues of clinical relevance, including duration and type of treatment and patient characteristics, including type of menopause (surgical versus natural), age, education and menopausal symptoms. Differences in participant characteristics and testing methods limit the ability to draw conclusions across randomized studies of HRT in non-demented women. The available evidence suggests no detrimental effect of HRT on cognitive function and inconsistent benefits on verbal memory and reasoning, frontal functions and speeded attention. Meta-analyses of observational trials suggest that HRT protects against the development of AD, but randomized trials indicate no long-lasting benefit in patients with AD. Evidence is insufficient to recommend HRT to maintain cognitive function.

Role of androgens in mild cognitive impairment and possible interventions during andropause

Mild cognitive impairment (MCI) is becoming fashionable as a diagnosis, representing a state of cognitive decline associated with negligible functional loss. MCI is important as it often precedes Alzheimer's disease (AD). Recognizing MCI may lead to preventive strategies that can delay the onset of AD. Many patients who transition into andropause report problems with their memory. There is strong evidence from basic sciences and epidemiological studies that both estrogens and androgens play a protective role in neurodegeneration. The evidence from small prospective clinical trials lends support to the role of hormones in improving cognitive function. The improvement in cognitive function with hormones is subtle and often not measurable on standard neuropsychological batteries. Patients have reported memory improvements in both declarative and procedural domains after being on hormonal replacement. Functional changes and vascular changes can be detected after hormonal replacement with more sophisticated imaging of the brain like positron emission tomography (PET) scans. We hypothesize androgens and perhaps selective androgen receptor modulators as future treatment options for MCI in aging males.

Estrogen activates protein kinase C in neurons: role in neuroprotection

It has been previously demonstrated that estrogen can protect neurons from a variety of insults, including beta-amyloid (Abeta). Recent studies have shown that estrogen can rapidly modulate intracellular signaling pathways involved in cell survival. In particular, estrogen activates protein kinase C (PKC) in a variety of cell types. This enzyme plays a key role in many cellular events, including regulation of apoptosis. In this study, we show that 17beta-estradiol (E2) rapidly increases PKC activity in primary cultures of rat cerebrocortical neurons. A 1 h pre-treatment with E2 or phorbol-12-myristate-13-acetate (PMA), a potent activator of PKC, protects neurons against Abeta toxicity. Protection afforded by both PMA and E2 is blocked by pharmacological inhibitors of PKC. Further, depletion of PKC levels resulting from prolonged PMA exposure prevents subsequent E2 or PMA protection. Our results indicate that E2 activates PKC in neurons, and that PKC activation is an important step in estrogen protection against Abeta. These data provide new understanding into the mechanism(s) underlying estrogen neuroprotection, an action with therapeutic relevance to Alzheimer's disease and other age-related neurodegenerative disorders.

Hormone replacement therapy: current controversies

Postmenopausal hormonal therapy is used to manage the climacteric symptoms that impair the quality of life of a substantial number of women. The difficulty is achieving the desired effects with minimal side-effects and no adverse health risks. Fundamental to this is understanding the physiology of oestrogen in women and the metabolism of the therapeutic compounds. Although the effects of oral oestrogen therapy have been studied extensively, there is insufficient evidence to assess adequately the independent effects of progestin use, other oestrogen compounds, differing doses and duration of treatment. We have reviewed some basic concepts of oestrogen physiology and how these relate to exogenous oestrogen administration, the risks of greatest concern, and the role of androgens and newer treatment alternatives.

Adjuvant breast cancer treatment and cognitive function: current knowledge and research directions

Evidence is mounting that potentially curative systemic adjuvant therapy for early-stage breast cancer may result in cognitive impairment. Five published studies have investigated cognitive function in this setting, and the consistent results of all five studies suggest an adverse effect of adjuvant chemotherapy. These studies are reviewed with particular attention to their methodologic limitations. For example, all five studies used cross-sectional designs, none controlled for possible confounding hormonal factors, and three examined patients who had not received a uniform chemotherapy regimen. The potential roles of chemotherapy-induced menopause and of adjuvant hormonal therapy in cognitive impairment are also discussed. Priorities for future research include confirmation of an effect of adjuvant chemotherapy in a study with a longitudinal design, closer examination of the potential contribution of hormonal factors, and similar studies on the effect of adjuvant therapy on cognitive function in other cancer types. If an effect of systemic adjuvant therapy on cognitive function is confirmed, such an effect will have implications for informed consent. It may also result in incorporation of objective measures of cognition in clinical trials of adjuvant therapy and in the investigation of preventive interventions that might minimize the impact of cognitive dysfunction after cancer treatment.

Are gonadal steroid hormones involved in disorders of brain aging?

Human aging is associated with a decrease of circulating gonadal steroid hormones. Since these hormones act as trophic factors for neurones and glia, it is possible that the decrease in sex steroid levels may contribute to the increased risk of neurodegenerative disorders with advanced age. Sex steroids are neuroprotective in several animal models of central and peripheral neurodegenerative diseases, and clinical data suggest that these hormones may reduce the risk of neural pathology in aged humans. Potential therapeutic approaches for aged-associated neural disorders may emerge from studies conducted to understand the mechanisms of action of sex steroids in the nervous system of aged animals. Alterations in the endogenous capacity of the aged brain to synthesize and metabolize sex steroids, as well as possible aged-associated modifications in the signalling of sex steroid receptors in the nervous system, are important areas for future investigation.

Estrogen replacement improves spatial reference memory and increases hippocampal synaptophysin in aged female mice

Estrogen deficiency during menopause is often associated with memory dysfunction. However, inconsistencies regarding the ability of estrogen to improve memory in menopausal women highlight the need to evaluate, in a controlled animal model, the potential for estrogen to alleviate age-related mnemonic decline. The current study tested whether estrogen could ameliorate spatial reference memory decline in aged female mice. At the conclusion of testing, levels of the presynaptic protein synaptophysin, and activities of the synthetic enzymes for acetylcholine and GABA, were measured in the hippocampus and neocortex. Aged (27-28-month-old) female C57BL/6 mice were given daily subcutaneous injections of 1 microg or 5 microg of beta-estradiol-3-benzoate dissolved in sesame oil. Control mice received daily injections of sesame oil or no injections. Estradiol treatment began 5 days prior to behavioral testing and continued throughout testing. Spatial and non-spatial memory were assessed in the Morris water maze. The 5 microg dose of estradiol significantly improved spatial learning and memory in aged females. The performance of 5 microg females improved significantly more rapidly than that of control females; estradiol-treated females performed at asymptotic levels by session 2. Furthermore, 5 microg females exhibited a more robust spatial bias than controls during probe trials. In contrast, 1 microg of estradiol did not improve spatial task performance. Neither dose affected performance of the non-spatial task. In the hippocampus, synaptophysin was increased in 5 microg females relative to controls. Estrogen did not affect enzyme activities in either brain region. This study is the first to examine the effects of estrogen replacement on spatial reference memory and synaptophysin expression in aged post-estropausal female rodents. The results suggest that: (1) estrogen can profoundly improve spatial reference memory in aged females, and (2) this improvement may be related to increased hippocampal synaptic plasticity, but not modulation of the synthetic enzymes for acetylcholine and GABA.

Estrogen receptor-alpha distribution in the human hypothalamus in relation to sex and endocrine status

The present study reports the first systematic rostrocaudal distribution of estrogen receptor-alpha immunoreactivity (ERalpha-ir) in the human hypothalamus and its adjacent areas in young adults. Postmortem material taken from 10 subjects (five male and five female), between 20 and 39 years of age, was investigated. In addition, three age-matched subjects with abnormal levels of estrogens were studied: a castrated, estrogen-treated 50-year-old male-to-female transsexual (T1), a 31-year-old man with an estrogen-producing tumor (S2), and an ovariectomized 46-year-old woman (S8). A strong sex difference, with more nuclear ERalpha-ir in women, was observed rostrally in the diagonal band of Broca and caudally in the medial mamillary nucleus. Less robust sex differences were observed in other brain areas, with more intense nuclear ERalpha-ir in men, e.g., in the sexually dimorphic nucleus of the medial preoptic area, paraventricular nucleus, and lateral hypothalamic area, whereas women had more nuclear ERalpha-ir in the suprachiasmatic nucleus and ventromedial nucleus. No nuclear sex differences in ERalpha were found, e.g., in the central part of the bed nucleus of the stria terminalis. In addition to nuclear staining, ERalpha-ir appeared to be sex-dependently present in the cytoplasm of neurons and was observed in astrocytes, plexus choroideus, and other non-neuronal cells. ERalpha-ir in T1, S2, and S8 suggested that most of the observed sex differences in ERalpha-ir are "activational" (e.g., ventromedial nucleus/medial mamillary nucleus) rather than "organizational." Species similarities and differences in ERalpha-ir distribution and possible functional implications are discussed.

Neuroinflammation and anti-inflammatory therapy for Alzheimer's disease

Neuroinflammation is now recognized as a prominent feature in Alzheimer's pathology and a potential target for therapy aimed at treatment and prevention of disease. This review provides a synopsis of current information about cellular and molecular mediators involved in Alzheimer's neuroinflammation as well as interactions between these mediators that influence pathology. Anti-inflammatory therapies, particularly nonsteroidal anti-inflammatory drugs, are considered from experimental and clinical perspectives and potential mechanisms underlying their apparent benefits are discussed. Finally, possible protective effects of the inflammatory response in Alzheimer's are described. Taken all together, evidence presented in this review suggests a scheme for Alzheimer's pathogenesis, with neuroinflammation playing a crucial role influencing and linking beta-amyloid deposition to neuronal damage and clinical disease.

A new series of estrogen receptor modulators that display selectivity for estrogen receptor beta

A series of 1,3,5-triazine-based estrogen receptor (ER) modulators that are modestly selective for the ERbeta subtype are reported. Compound 1, which displayed modest potency and selectivity for ERbeta vs ERalpha, was identified via high-throughput screening utilizing an ERbeta SPA-based binding assay. Subsequent analogue preparation resulted in the identification of compounds such as 21 and 43 that display 25- to 30-fold selectivity for ERbeta with potencies in the 10-30 nM range. These compounds profile as full antagonists at ERbeta and weak partial agonists at ERalpha in a cell-based reporter gene assay. In addition, the X-ray crystal structure of compound 15 complexed with the ligand binding domain of ERbeta has been solved and was utilized in the design of more conformationally restrained analogues such as 31 in an attempt to increase selectivity for the ERbeta subtype.

Effects of epoetin alfa on cognitive function, mood, asthenia, and quality of life in women with breast cancer undergoing adjuvant chemotherapy

Several recently published studies describe moderate to severe cognitive dysfunction in breast cancer survivors who were treated with adjuvant chemotherapy 1-5 years before undergoing extensive neuropsychological testing. While these studies are hypothesis-generating and preliminary given their small size and retrospective nature, they consistently suggest that between approximately 15% and 25% of chemotherapy-treated breast cancer patients will have evidence of cognitive dysfunction some years after chemotherapy, compared to about 10% of breast cancer survivors who did not receive chemotherapy. Recent preclinical data strongly suggest that erythropoetin is a potent, endogenous neuroprotective agent that prevents neuronal apoptosis from a variety of insults including hypoxia, trauma, subarachnoidal hemorrhage, and encephalitis. Erythropoietin also appears to enhance learning in a mouse spatial learning maze model. We have conducted a pilot study of epoetin alfa versus placebo in early-stage breast cancer patients who received standard adjuvant anthracycline-based chemotherapy to determine the feasibility of administering standardized neurocognitive assessment tests in the oncology practice setting in order to understand whether the Executive Interview 25 test can detect the subtle cognitive impairment in verbal fluency, attention, and short-term memory observed with chemotherapy, and to assess whether epoetin alfa-treated patients have less evidence of cognitive dysfunction during and 6 months after chemotherapy compared with control-treated patients. We report here the preliminary results of this pilot clinical trial.

The effects of beta-estradiol on SHSY5Y neuroblastoma cells during heavy metal induced oxidative stress, neurotoxicity and beta-amyloid secretion

The role of estrogen as a neurotrophic/neuroprotective agent in neurodegenerative diseases such as Alzheimer's and Parkinson's diseases is increasingly being shown. In this study we examine the neuroprotective effects of beta-estradiol on SHSY5Y neuroblastoma cells which have been exposed to the heavy metals cobalt and mercury. The results show that cobalt and mercury are able to induce oxidative stress and cell cytotoxicity and increase the secretion of beta-amyloid 1-40 and 1-42. These deleterious effects are reversed by the pretreatment of cells with beta-estradiol. It is further shown that beta-estradiol exerts its neuroprotective action through mechanisms which reduce oxidative stress and reduce beta-amyloid secretion. Pre-treatment of the cells with alpha-estradiol did not alleviate the toxic effects of the heavy metals. Our results are significant as they contribute to a better understanding of the mode of action of estrogen with relevance to its use in the treatment of neurodegenerative disorders.

Effect of postmenopausal hormone therapy on cognitive function: the Heart and Estrogen/progestin Replacement Study

PURPOSE

To determine if hormone therapy results in better cognitive function in older postmenopausal women.

SUBJECTS AND METHODS

The Heart and Estrogen/progestin Replacement Study (HERS) was a randomized, placebo-controlled trial involving 2763 women with coronary disease. Women were assigned randomly to conjugated estrogen (0.625 mg) plus medroxyprogesterone acetate (2.5 mg) in one tablet daily or identical placebo; they were followed for a mean (+/- SD) of 4.2 +/- 0.4 years. Participants at 10 of the 20 HERS centers were invited to enroll in the cognitive function substudy. At the end of the trial, we measured cognitive function in 517 women in the hormone group and 546 in the placebo group using six standard tests: the modified Mini-Mental Status Examination, Verbal Fluency, Boston Naming, Word List Memory, Word List Recall, and Trails B. Cognitive function was not measured at baseline.

RESULTS

The mean age of participants at the time of cognitive function testing was 71 +/- 6 years. There were no differences in age-adjusted cognitive function test scores between the two treatment groups, except that women assigned to hormones scored worse on the Verbal Fluency test than women assigned to placebo (15.9 +/- 4.8 vs. 16.6 +/- 4.8, P = 0.02). Adjustment for other potential confounders and restriction of the analyses to women who had been adherent to study medication did not change the results.

CONCLUSION

Among older postmenopausal women with coronary disease, 4 years of treatment with postmenopausal hormone therapy did not result in better cognitive function as measured on six standardized tests. Whether these results also apply to elderly women without coronary disease cannot be determined from this study.

Mood symptoms and cognitive performance in women estrogen users and nonusers and men

OBJECTIVES

Previous studies have suggested sex differences in mood and cognition and that estrogen effects may partially explain such differences. In this study, we explore sex differences for a range of mood symptoms and for neuropsychological performance in men and postmenopausal women and assess the potential influence of estrogen on these measures.

DESIGN

Cross-sectional study of men and women examining mood, neuropsychological test data, and estrogen replacement therapy (ERT) use.

SETTING

Outpatient study at an urban teaching hospital with subjects recruited from the community.

PARTICIPANTS

All subjects (N = 96) were between the ages of 57 and 75 and included 31 women using ERT, 16 non-ERT users, and 49 men. Subjects did not have major depression and were nondemented.

MEASUREMENT

The three groups were compared according to profile of mood states and neuropsychological performance, and statistical analyses were controlled for socioeconomic status, age, and education level.

RESULTS

Female ERT users were less depressed and less angry and performed better on measures of verbal fluency and working memory than the other subject groups.

CONCLUSION

Postmenopausal estrogen use is associated with better mood and cognitive performance on tasks of fluency and working memory. These results suggest that estrogen should be examined as a potentially critical variable influencing late-life sex differences in mood and cognition.

Estrogen and cognitive aging in women

The steady increase in female life expectancy has attracted attention to the importance of preventing cognitive aging and Alzheimer's disease (AD) in women. Evidence from randomized, controlled trials and from cross-sectional and longitudinal studies shows that estrogen-replacement therapy preferentially protects against a decline in verbal memory in healthy postmenopausal women and decreases the risk of AD. Although results are not consistent across studies, they indicate that treatment with estrogen during the postmenopausal years might protect against cognitive aging in women during the latter part of their life.

Thinking preventively about dementia: a review

BACKGROUND

The dementias of late life now constitute a major public health challenge to our society.

OBJECTIVE

To examine the contributions of neuroscience, clinical treatment and health-care policy to the building of a national programme for preventive approaches to dementia.

METHOD

Critical review of the literature, making use of international databases (Medline, Embase, Psychlit) and British official publications.

RESULTS

Recent developments in a number of research fields afford prospects for advances in primary and secondary prevention. These include findings from case-control and cohort studies of associations with earlier head injury and vascular disease, possibilities of pharmacological protection for persons at high risk for Alzheimer's disease, and the use of more effective anti-dementia drugs in the mild to moderate stages of severity. Research aimed at tertiary prevention is lagging behind, but there are some indications that the worst features of late-stage decline could already be mitigated by improvements in community support services and nursing-home care.

CONCLUSIONS

Containment of the growing social and economic burdens of dementia calls for a national policy to ensure that new research findings can be translated into practice and applied to the benefit of all old people who stand in need. For this purpose the most appropriate conceptual framework is supplied by a preventive model, broadly similar to those already developed for some other forms of chronic degenerative disease.

Long-term estrogen therapy worsens the behavioral and neuropathological consequences of chronic brain inflammation

Alzheimer's disease (AD) is accompanied by chronic neuroinflammation and occurs with greater incidence in postmenopausal women. The increased incidence may be delayed by estrogen replacement therapy (ERT). The authors investigated the interaction of chronic ERT and lipopolysaccharide (LPS)-induced neuroinflammation in the female rat. Ovariectomy did not impair water maze performance; however, addition of chronic ERT or neuroinflammation resulted in an impairment that became exacerbated by the simultaneous occurrence of both conditions. Chronic LPS activated microglia, which was not reduced by ERT. Intact females receiving LPS infusion were not impaired in the water maze and had significantly fewer activated microglia. Results suggest that chronic ERT in postmenopausal women may exacerbate the memory impairment induced by the chronic neuroinflammation associated with AD.

Prevention of Alzheimer's disease: where we stand

Alzheimer's disease has been recognized as a major public health issue that will grow in prominence as life expectancy increases and as the shape of population demographics shifts toward expansion in the older age ranges with contraction in younger ages. The magnitude of the problem can be expressed in incidence, prevalence economics, and quality of life. Great strides have been made in understanding and treating this disease, but current clinical management is far from satisfactory and progression seems inevitable once the disease is diagnosed. Such forces in any disease encourage intervention strategies to move from treatment to prevention. However, this vision can only be met with reasonable success when pathology is understood and there is evidence that manipulation of that pathology leads to clinical benefit. This is the challenge that lies ahead to achieve the goal of prevention of Alzheimer's disease. This review begins by examining the progress that has been made in this disease. Current efforts to develop prevention strategies are described and possible agents for future evaluation are discussed.

Cognitive decline among female estrogen users in nursing homes

BACKGROUND

Clinical and epidemiological research has been done regarding the potential therapeutic benefit of estrogen in outpatients with and without dementia; however, the effects of estrogen therapy on cognition in elderly nursing home patients have not been previously examined.

METHODS

This retrospective cohort study compared 191 women estrogen users with 663 women nonestrogen users, matched according to age, nursing home facility, year of assessment, and baseline level of cognitive function. The outcome was decline in cognition, measured by the Cognitive Performance Scale, over a minimum follow-up period of 6 months.

RESULTS

No significant difference was found in the rate of cognitive decline among estrogen users and nonusers.

CONCLUSIONS

Estrogen therapy administered to nursing home residents is not associated with a reduction in cognitive decline. This study lends further support to recent controlled clinical trials that found no benefit for estrogen treatment on cognition in outpatients with dementia.

Oestrogen has neuroprotective effects and may reduce the risk of Alzheimer's disease

Evidence from both animals and humans supports a neuroprotective role of oestrogen. Epidemiological studies showing that oestrogen improves cognitive performance in postmenopausal women, clinical trials showing effects of oestrogen on cognition and data suggesting that oestrogen reduces the risk of Alzheimer's disease (AD) led to the proposal that oestrogen may be effective for improving symptoms or slowing decline in women with AD. Studies evaluating oestrogen as a treatment for AD have been performed with mixed findings. While a few studies have found modest improvements, the results have largely been disappointing. However, many of the studies suffer from substantial methodological problems that leave the findings in question. The role of oestrogen for the prevention or treatment of AD is not yet clear, but large, well-controlled, ongoing trials should provide definitive answers to many questions in the near future.

Barriers to remember: brain-targeting chemical delivery systems and Alzheimer's disease

Brain-targeted chemical delivery systems (CDSs) represent rational drug design attempts not only to deliver but also to target drugs to their site of action. Using a sequential metabolism approach, the special bidirectional properties of the blood-brain barrier can be exploited to smuggle the precursors of therapeutic compounds across the barrier and lock them inside the brain ready for sustained release of the active drugs. Many potential therapeutic applications can be envisioned for such CDSs; here, the potential of brain-targeted estradiol for the prevention and treatment of Alzheimer's disease is reviewed in detail.

Chemoprevention of breast cancer: implications for postmenopausal women

Estrogen administration is associated with reduction in perimenopausal symptoms and the risk for several conditions affecting postmenopausal women. As estrogen administration also increases the risk for breast cancer, a common dilemma facing many women and their physicians is whether to use estrogen replacement therapy (ERT), a selective estrogen receptor modulator (SERM) that antagonises estrogenic effects in breast tissue but retains some estrogen agonist properties in other organs, or neither. For women with average to moderate risk of breast cancer and with perimenopausal symptoms, ERT may be the best short-term choice. For very high-risk women (>1% per year) with menopausal symptoms, alternatives to ERT might be offered and tried first. A diagnosis of ductal carcinoma in situ or invasive breast cancer within the last 2 to 5 years should be considered a relative contraindication for ERT unless the tumour was estrogen receptor negative. High-risk women without menopausal symptoms are the best candidates for the only currently approved drug for breast cancer risk reduction, tamoxifen. Although the drug is approved for women with a 5-year risk of breast cancer > or = 1.7% (0.34% per year), postmenopausal women most likely to experience a favourable benefit/risk ratio are those with a Gail estimated risk of >0.5% per year without a uterus or >1% per year if they retain their uterus. Tamoxifen should not be used in women with prior history of thromboembolic or precancerous uterine conditions. Tamoxifen is often used in Europe in conjunction with transdermal ERT in hysterectomised women without obvious loss of efficacy or increased risk of thromboembolism. Raloxifene is a second generation SERM with estrogen-like agonist effects on bone but with less uterine estrogen agonist activity than tamoxifen. Raloxifene may have less potent breast antiestrogenic effects than tamoxifen, particularly in a moderate- to high-estrogen environment. Raloxifene is approved for use in reducing risk of osteoporosis, but not breast cancer. Whether it is as effective as tamoxifen in reducing breast cancer risk in postmenopausal women is the subject of a current trial. All women regardless of breast cancer risk are advised to employ nonpharmacological risk reduction measures, including normalisation of bodyweight, exercise, adequate calcium and vitamin D intake, and avoidance of smoking and alcohol. The preventive options are best weighed during an individualised consultation where a woman's menopausal symptoms and risk for breast cancer and other diseases can be examined, and the options for improving postmenopausal health can be discussed.

Neuroprotective and neurotrophic efficacy of phytoestrogens in cultured hippocampal neurons

Epidemiological data from retrospective and case-control studies have indicated that estrogen replacement therapy (ERT) can decrease the risk of developing Alzheimer's disease. In addition, ERT has been found to promote cellular correlates of memory and to promote neuronal survival both in vivo and in vitro. Phytoestrogens have been proposed as potential alternatives to ERT. To determine whether phytoestrogens exert estrogen agonist effect in neural tissue, investigations of neuroprotective and neurotrophic efficacy of phytoestrogens were conducted. Six phytoestrogens, genistein, genistin, daidzein, daidzin, formononetin, and equol, were tested for their neuroprotective efficacy against two toxic insults, glutamate excitotoxicity and beta-amyloid(25-35). Neuronal membrane damage was quantitatively measured by lactate dehydrogenase (LDH) release, and neuronal mitochondrial viability was determined by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromid (MTT) assay. Results of these studies demonstrated that all phytoestrogens induced a modest but significant reduction in LDH release following exposure to glutamate and beta-amyloid(25-35). In contrast, none of phytoestrogens induced a significant increase in reduced MTT levels, which occurred in the presence of a full estrogen agonist, 17beta-estradiol. Analysis of the neurotrophic potential of genistein and daidzein, two phytoestrogens that exerted a significant reduction in LDH release, demonstrated that neither of these molecules promoted hippocampal neuron process outgrowth. Results of these analyses indicate that although phytoestrogens exert a neuroprotective effect at the plasma membrane, they do not sustain neuron mitochondrial viability nor do they induce cellular correlates of memory as neurite outgrowth and synaptogenesis are putative mechanisms of memory. Data derived from these investigations would predict that phytoestrogens could exert some neuroprotective effects analogous to that of antioxidants, but that these molecules are not functional equivalents to endogenously active 17beta-estradiol or to estrogen replacement formulations and, therefore, would raise the concern that they may not reduce the risk of Alzheimer's disease or sustain memory function in postmenopausal women.

Achieving and maintaining cognitive vitality with aging

Cognitive vitality is essential to quality of life and survival in old age. With normal aging, cognitive changes such as slowed speed of processing are common, but there is substantial interindividual variability, and cognitive decline is clearly not inevitable. In this review, we focus on recent research investigating the association of various lifestyle factors and medical comorbidities with cognitive aging. Most of these factors are potentially modifiable or manageable, and some are protective. For example, animal and human studies suggest that lifelong learning, mental and physical exercise, continuing social engagement, stress reduction, and proper nutrition may be important factors in promoting cognitive vitality in aging. Manageable medical comorbidities, such as diabetes, hypertension, and hyperlipidemia, also contribute to cognitive decline in older persons. Other comorbidities such as smoking and excess alcohol intake may contribute to cognitive decline, and avoiding these activities may promote cognitive vitality in aging. Various therapeutics, including cognitive enhancers and protective agents such as antioxidants and anti-inflammatories, may eventually prove useful as adjuncts for the prevention and treatment of cognitive decline with aging. The data presented in this review should interest physicians who provide preventive care management to middle-aged and older individuals who seek to maintain cognitive vitality with aging.

Cognitive function effects of suppressing ovarian hormones in young women

OBJECTIVE

To evaluate the effect of a pharmacologically induced, temporary suppression of ovarian hormones on healthy young women's cognitive functioning.

DESIGN

Sixteen healthy women with normal menstrual cycles completed the California Verbal Learning Test, a digit span test, and a verbal fluency test in the follicular phase of a normal menstrual cycle and a second time after four monthly injections of the gonadotropin-releasing hormone (GnRH) agonist. Women were randomly assigned to complete a third testing either after resuming cycles in the follicular phase or after three more injections of the GnRH agonist and while wearing an estradiol patch. The control group consisted of 10 women who were tested three times in the follicular phase of their menstrual cycles.

RESULTS

Results showed no change in cognitive functioning across sessions or groups in women with suppressed ovarian function. Women who had the highest levels of menopausal symptoms when taking the GnRH agonist did not have significantly lower cognitive functioning.

CONCLUSIONS

This study did not find any effect of suppression in ovarian hormones on cognitive performance of young women.

Estradiol, but not raloxifene, improves aspects of spatial working memory in aged ovariectomized rhesus monkeys

Estrogen replacement therapy (ERT) alleviates many postmenopausal symptoms but whether it also benefits cognitive function remains controversial. Further, since estrogen increases the risk of breast and uterine cancers, a new class of compounds, called selective estrogen receptor modulators (SERMs) is being considered as possible alternative to ERT. The SERM raloxifene is particularly interesting because, like estrogen, it improves lipid metabolism and reduces bone loss, without adverse effects on the breast or uterus. Little is known, however, about its effect upon cognitive function. We used a rhesus monkey model of human menopause to examine the effects of ERT and raloxifene on cognitive function. We tested 5 aged females (21-24 years old) ovariectomized long-term (10-16 years) on a battery of age-sensitive tasks, including the Delayed Response (DR), the Delayed Non-Matching-to-Sample-10 min (DNMS-10 min) and the spatial-Delayed Recognition Span Test (DRST). Monkeys were tested 5 days a week on each task for 9 consecutive months, while undergoing treatments with placebo, ethinyl estradiol (EE(2)), and raloxifene in alternating 28-days blocks. EE(2) transiently enhanced the working memory component of the spatial-DRST, but did not affect performance on the other tasks of the battery. Raloxifene had no effect on cognitive performance. These findings indicate that estradiol is able to enhance some aspects of spatial working memory in aged monkeys despite many years of estrogenic deprivation. Further, they suggest that raloxifene does not affect cognitive function after long-term ovarian hormone deprivation.

The relationship of race/ethnicity and social class to hormone replacement therapy: results from the Third National Health and Nutrition Examination Survey 1988-1994

OBJECTIVE

To use a nationally representative sample to examine the prevalence of hormone replacement therapy (HRT) use and its relationship to different markers of social class in American women 60 years of age and older.

DESIGN

Nationally representative cross-sectional survey with an in-person interview and medical examination. Between 1988 and 1994, 3,479 women aged 60 to 90+ years were examined as part of the National Health and Nutrition Examination Survey III. Mexican Americans, non-Hispanic blacks and much older women were oversampled to produce reliable estimates for these groups.

RESULTS

Overall, the number of women who reported ever having used HRT was 37% [confidence interval (CI), 33%-40%] of all women older than 60 years of age; 40% (CI, 37%-41%) of older, non-Hispanic white women; 20% (CI, 14%-25%) of non-Hispanic black women; and 24% (CI, 20%-29%) of Mexican American women. HRT was used by 43% (CI, 38%-47%) of women 60 to 70 years old, 37% (CI, 32%-41%) of those 71 to 80 years old, and 20% (CI, 13%-26%) of women older than 80. HRT use was lowest among women who did not complete high school or among those in the lowest family income categories. Among women more than 60 years old who reported having a hysterectomy, 51% (CI, 47%-55%) reported using HRT, whereas only 20% (CI, 17%-23%) of those who had a natural menopause reported using HRT.

CONCLUSIONS

Although many women can benefit from HRT, the number of American women who report they have ever used it remains low. More research is needed to examine the implications of racial differences in compliance, patient and physician attitudes toward HRT, and possible environmental barriers that may prevent use.

Frontiers in Neuropharmacotherapy Part I: Alzheimer’s Disease and Epilepsy

Cholinesterase inhibitors, and particularly donepezil, are the standard of care in the management of Alzheimer’s disease. Newer agents, such as rivastigmine, galantamine, and metrifonate, provide therapeutic alternatives but have advantages and disadvantages compared with donepezil. Clinical studies and continued research of the pathophysiology of Alzheimer’s disease help define the role of both the newer agents and the original cholinesterase inhibitor, tacrine. Therapies with other mechanisms of action, such as estrogen and nonsteroidal anti-inflammatory drugs (NSAIDs), are also being actively investigated for their effects on cognition. Since 1993, 8 new antiepileptic drugs have been approved by the FDA, including felbamate, gabapentin, lamotrigine, topiramate, tiagabine, and 3 recently introduced agents, oxcarbazepine, levetiracetam, and zonisamide. These second-generation agents are generally more tolerable and have fewer drug interactions than traditional antiepileptics, and some provide alternative mechanisms that may be beneficial in the management of refractory epileptic disorders. However, until clinical experience with the newer antiepileptics accumulates and well-designed comparative trials are conducted, a review of individual studies of the safety and efficacy of the newer agents helps provide the basis for treatment decisions. New information regarding traditional therapies, including new formulations and updated treatment guidelines, also assist clinicians in optimizing antiepileptic therapy.

The effects of estrogen replacement therapy on neuropsychological functioning in postmenopausal women with and without dementia: a critical and theoretical review

We review 42 studies examining the effects of estrogen replacement therapy (ERT) on memory and cognition in nondemented postmenopausal women. Although there are an appreciable number of nonsignificant findings, the number of significant findings favoring ERT users considerably outnumbers the rare findings of better performance in controls. Experimental studies demonstrate a consistent beneficial effect on verbal memory, but these are short-term studies of the more acute effects of ERT. The observational studies suggest that there may be a long-lasting effect of continued ERT on cognitive functioning, but these studies need to be interpreted with caution because of the lack of random assignment and a possible "healthy user bias." We also summarize findings from studies on the effects of ERT on Alzheimer's disease (AD). ERT is associated with a decreased risk for dementia, but there is little evidence for a positive effect on cognition in women with AD. Definitive answers to questions about the long-term effects of ERT on cognitive aging and risk of developing AD should be provided by 3 ongoing clinical trials.

Psychosocial aspects of selected issues in women's reproductive health: current status and future directions

Emphasizing research published in the past decade, this article presents a summary and evaluation of psychosocial investigations of women's reproductive health, with a focus on selected aspects of menstruation, pregnancy and birth, infertility, and menopause. In some areas, studies have focused on negative physical and psychological concomitants of these health issues. However, research reveals substantial individual variability, with most women adapting well to reproductive health changes. Although methodological and conceptual shortcomings have limited firm conclusions, research has advanced our understanding of the multivariate biological, psychological, and social influences on women's reproductive health and associated outcomes. Understanding and promoting women's reproductive health across the lifespan requires biopsychosocial approaches to research.

Impact of progestins on estradiol potentiation of the glutamate calcium response

One mechanism by which estrogen may modulate cognitive function is through potentiation of glutamate-mediated rises in intracellular calcium ([Ca2+]i) with resultant effects on neuronal morphology and signaling. Since progesterone is a component of hormone replacement therapy (HRT), we sought to determine whether therapeutically relevant progestins attenuated or blocked estrogen potentiation of glutamate-induced [Ca2+]i rises. 17beta-estradiol and progesterone, alone or in combination, significantly potentiated the rise in [Ca2+]i. When co-administered, progesterone attenuated the estrogen response to the level seen with progesterone alone. In contrast, medroxyprogesterone acetate (MPA) had no effect when administered alone and completely blocked the 17beta-estradiol-induced potentiation when co-administered. These results may have important implications for effective use of HRT to maintain cognitive function during menopause and aging.

Estrogen and brain vulnerability

Accumulated clinical and basic evidence suggests that gonadal steroids affect the onset and progression of several neurodegenerative diseases and schizophrenia, and the recovery from traumatic neurological injury such as stroke. Thus, our view on gonadal hormones in neural function must be broadened to include not only their function in neuroendocrine regulation and reproductive behaviors, but also to include a direct participation in response to degenerative disease or injury. Recent findings indicate that the brain up-regulates both estrogen synthesis and estrogen receptor expression at sites of injury. Genetic or pharmacological inactivation of aromatase, the enzyme involved in estrogen synthesis, indicates that the induction of this enzyme in the brain after injury has a neuroprotective role. Some of the mechanisms underlying the neuroprotective effects of estrogen may be independent of the classically defined nuclear estrogen receptors (ERs). Other neuroprotective effects of estrogen do depend on the classical nuclear ERs, through which estrogen alters expression of estrogen responsive genes that play a role in apoptosis, axonal regeneration, or general trophic support. Yet another possibility is that non-classical ERs in the membrane or cytoplasm alter phosphorylation cascades, such as those involved in the signaling of insulin-like growth factor-1 (IGF-1). Indeed, ERs and IGF-1 receptor interact in the activation of PI3K and MAPK signaling cascades and in the promotion of neuroprotection. The decrease in estrogen and IGF-1 levels with aging may thus result in an increased risk for neuronal pathological alterations after different forms of brain injury.

Endogenous estradiol and testosterone levels are associated with cognitive performance in older women and men

Relatively few studies have investigated the relationship between endogenous sex steroid levels and cognition in older people and the reported results have been inconsistent. A number of experimental hormone replacement studies have suggested that estrogen replacement in older women enhances cognition, especially verbal memory. In contrast, little research has been done focusing on men. In the current study the association between endogenous sex steroids (estradiol and testosterone) and cognition was investigated in 38 healthy older women (mean age 68 years) and 30 healthy older men (mean age 69 years). Five cognitive tests measuring verbal memory, spatial memory, verbal fluency, mental rotation, and susceptibility to interference were administered. Results revealed that in women higher estradiol levels as well as testosterone levels were associated with better verbal memory (paired associates and estradiol; r =.38, P < 0.05; paired associates and testosterone; r =.33, P < 0.05;). Moreover estradiol, but not testosterone was associated with less susceptibility to interference (Stroop color word test; r = -0.34, P < 0.05). In men the only significant association was a negative correlation between testosterone and verbal fluency (r = -0.38, P < 0.05). The associations observed in this small study support the notion that estradiol is protecting verbal memory and possibly also frontal lobe mediated functions in older women. In contrast to the positive findings in women endogenous sex steroids do not appear to be closely linked to better cognition in older men.

Dementia epidemiology

Determining the incidence and prevalence of dementia is an inexact science. Dementia is difficult to define and detect in the population. Even with the difficulties of determining prevalence and incidence, it is clear that dementia causes a substantial burden on our society. Problems with diagnostic inaccuracy and insidious disease onset influence our ability to observe risk factor associations; factors related to survival may be mistaken for risk/protective factors. Current studies suggest that factors influencing brain development or cognitive reserve may delay the onset of AD, perhaps through a protective mechanism or a delay in diagnosis caused by improved performance on cognitive tests. The recent identification of genes that cause dementia suggests that these genes or their biochemical pathways may be involved in the pathogenesis of nonfamilial cases. The contribution of genes that cause disease in and of themselves may be smaller than that of genes that act to metabolize or potentiate environmental exposures. The interaction between gene and environment should be increasingly well studied in the future. Epidemiology must take advantage of these molecular advances. The tasks of public health and epidemiology should still involve prevention, the nonrandom occurrence of disease, and its environmental context in addition to heredity. The tools to address these tasks should continue to be refined.

The effects of tibolone on mood and libido

OBJECTIVE

To review published data pertaining to the effects of tibolone on sexual parameters, mood, and cognitive function in postmenopausal women.

DESIGN

A review of all relevant published, peer-reviewed studies.

RESULTS

Tibolone is a compound that can be selectively metabolized by individual tissues to its estrogenic, progestogenic, or androgenic metabolites and hence exhibits tissue-specific hormonal effects. Tibolone also lowers sex hormone binding globulin, thus increasing free estradiol and testosterone levels. Tibolone alleviates climacteric vasomotor symptoms and displays a dominant progestogenic effect on the endometrium. Tibolone normalizes the vaginal karyopyknotic and maturation indexes and alleviates symptomatic atrophic vaginitis. Women treated with tibolone report significant reductions in vaginal dryness and dyspareunia, effects that may be secondary to both estrogenic and androgenic actions. Randomized studies indicate tibolone has positive effects on mood compared with placebo and alleviates several adverse mood parameters to a similar extent as conventional hormone replacement therapy. Improved mood is associated with increased plasma beta-endorphin. With respect to cognition, tibolone seems to improve semantic memory but does not significantly improve recognition memory. Tibolone is associated with improvements in sexual function that seem to be greater than those achieved with standard hormone replacement therapy.

CONCLUSION

Published studies indicate beneficial effects of tibolone on both libido and mood, which otherwise significantly compromise physical, psychological, and social well-being. Hence, tibolone provides another option for menopausal women experiencing loss of libido as part of their symptomatology or who have persistent low libido despite adequate estrogen/progestin replacement therapy.

Is pharmacological prevention of Alzheimer's a realistic goal?

A growing body of evidence suggests that several classes of drugs marketed for other indications may be effective in the prevention of Alzheimer's disease. Among the most promising of these are nonsteroidal anti-inflammatory agents, oestrogens (oestrogen replacement therapy) and antioxidant vitamins. Other less well-established candidates include histamine H(2) receptor antagonists (H(2) blockers) and 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins). For each of these, we discuss possible mechanisms for their postulated neuroprotective effects and review the studies suggesting their benefits in Alzheimer's disease. We conclude that nonsteroidal anti-inflammatory drugs and oestrogen replacement therapies may be effective in preventing Alzheimer's disease only if taken during the latent phase of the disease several years prior to the appearance of disturbances. Antioxidants may also prevent Alzheimer's disease, but unlike nonsteroidal anti-inflammatory drugs and oestrogen replacement therapies, they may continue to have beneficial effects even after the clinical onset of the disease. The only way to demonstrate the efficacy of these agents will be through randomised, controlled prevention trials. Such trials are currently underway but conclusive results may not be available for several years. Although intriguing, more studies on the neuroprotective effects of statins and H(2) blockers are needed before trials of these agents are initiated. Finally, there are other classes of pharmacological compounds emerging on the horizon, including folic acid, anti-beta-sheet conformational agents, secretase inhibitors and vaccines, that may soon prove to be effective for the prevention of Alzheimer's disease.

Coronary Heart Disease in Women: Hormone Replacement Therapy

For both primary and secondary prevention of coronary heart disease (CHD), it is prudent to use strategies that are of proven benefit and that do not harm patients. In all women, these strategies include lifestyle approaches such as smoking avoidance, proper nutrition, and regular exercise. Lipid-lowering and blood pressure control with pharmacotherapy are indicated in women who do not meet target lipid or blood pressure levels with lifestyle interventions. For women with CHD, aspirin, beta-blockers, and angiotensin-converting enzyme inhibitors should be considered. Widespread under-use of established preventive therapies has been documented in women. These interventions should be emphasized in clinical practice. For secondary prevention of CHD in women, the American Heart Association (AHA) recommends against initiating hormone replacement therapy (HRT) based on studies that have shown no benefit and early harm. For patients with CHD already on HRT, the decision to continue or stop HRT should be based on established noncoronary benefits and risks and patient preference. There are insufficient data to suggest that HRT should be initiated for the sole purpose of primary prevention of CHD. Because the new AHA guidelines recommend placing significant weight on the noncardiac benefits and risks of HRT, it is important to become familiar with these noncardiac effects. It is also important to understand the evidence supporting the AHA's decision to recommend placing relatively less weight on the cardiac effects of HRT.

Estrogen and the cholinergic system modulate visuospatial attention in monkeys (Macaca fascicularis)

This study determined the effects of estrogen on attention and motor speed in young monkeys (Macaca fascicularis). Performance on visuospatial attention and reaction time motor tasks was measured before ovariectomy, for 2 months after ovariectomy, and at 14 months after treatment with placebo or estrogen replacement therapy (ERT). Release time on invalid trials in the attention task was increased after ovariectomy and was reduced in monkeys treated with ERT. but not placebo. Simple reaction time was not altered after ovariectomy or treatment. The effects of scopolamine on attention, but not memory, in a delayed response task were dependent on estrogen. These observations indicate that loss of estrogen modulates visuospatial attention in primates and that 1 mechanism of this modulation is through the cholinergic system.

Ocorrência e tratamento de quadros depressivos por hormônios sexuais

O processo de envelhecimento promove alterações significativas na produção e no equilíbrio dos níveis circulantes de diversos hormônios sexuais em homens e mulheres. Acredita-se que esses hormônios (estrógenos, progestógenos, testosterona, dehidroepiandrosterona [DHEA]) exercem papel modulador sobre diversas funções psíquicas, particularmente sobre o humor e a cognição. Alterações nesse papel modulador causadas por variações abruptas dos hormônios sexuais circulantes -- como as que ocorrem, por exemplo, durante a transição menopausal -- favorecem o surgimento de queixas depressivas. No entanto, a utilização terapêutica de hormônios sexuais pode promover alívio ou mesmo remissão de sintomas depressivos, como já foi caracterizado com o uso de estradiol em mulheres em perimenopausa e com a administração de testosterona após a menopausa. Este artigo aborda, por revisão da literatura, os diversos papéis atribuídos aos hormônios sexuais no desenvolvimento e tratamento das queixas depressivas. Estudos sobre a eficácia terapêutica de estrógenos, testosterona e DHEA nos quadros depressivos são discutidos de forma crítica. Em essência, existem resultados preliminares bastante promissores, particularmente quanto ao uso de estradiol e testosterona em subpopulações específicas para alívio de sintomas depressivos. Futuras investigações devem melhor definir a utilização de hormônios como agente depressivo monoterápico ou adjuntivo, bem como delinear os riscos e as contra-indicações associados a seu uso.

Resistive index of renal artery and blood pressure in postmenopausal women

Causal association between perimenopausal changes and symptoms and disease is commonly accepted even if not definitely explained. Resistive index (RI) of renal artery assessed by Doppler echography is related to renal function and systemic circulatory adaptation in patients with chronic renal failure and hypertension. Echocardiographic measurement of left ventricular myocardial mass (LVMM) is a useful tool for assessing effects of arterial hypertension on heart. Aim of the study was to assess RI in normotensive postmenopausal women and relationship, if any, with blood pressure and LVMM. We studied 28 normotensive, non-obese postmenopausal women, age 52.21 +/- 5.40 years, with normal creatinine clearance. Renal colour-Doppler echography was performed assessing intra-parenchimal renal artery mean velocity (mVRA) and intra-parenchimal RI [(peak systolic velocity - end diastolic velocity)/peak systolic velocity]. Echocardiography was performed as well. RI of intra-parenchimal renal artery is 0.67 +/- 0.05 and it shows correlations vs. diastolic blood pressure (r=0.41; P<0.03) and vs. mean BP (r=0.47; P<0.01). LVMM has correlation (r=0.41; P>0.03) with RI. Age, body weight, body mass index, menarche age, fertility years and postmenopausal years do not show correlation with RI. Heart rate, creatinine clearance, hemoglobin, serum albumin do not show any correlation with RI. Higher RI is associated with alcohol intake, liver steatosis, biliary gallstones and family history of diabetes mellitus, but not with postmenopausal years, unrespective of surgical or non-surgical menopause. Among echocardiographic measurements only LVMM is correlated with RI; mVRA does not show correlation. LVMM and BP do not show other independent correlation except that the one already reported vs. RI. RI, as a pathophysiological measurement whose increase preludes to arterial hypertension, could help to ascertain perimenopausal women at risk for arterial hypertension and left ventricular hypertrophy, but does not seem directly associated with the loss of ovarian function.

Dual action of estrogen on glutamate-induced calcium signaling: mechanisms requiring interaction between estrogen receptors and src/mitogen activated protein kinase pathway

Conjugated equine estrogens (CEE) is the most widely prescribed pharmaceutical estrogen replacement therapy (ERT) for postmenopausal women in the United States and is the ERT of the Women's Health Initiative. Previous studies from our laboratory have demonstrated that CEE exerts neurotrophic and neuroprotective effects in neurons involved in learning and memory, and which are affected in Alzheimer's disease. The present work demonstrates that CEE potentiated the rise in intracellular calcium ([Ca(2+)](i)) following exposure to physiological concentrations of glutamate. In contrast, the reverse effect occurred in the presence of excitotoxic levels of glutamate exposure, where CEE attenuated the rise in [Ca(2+)](i). Potentiation of the glutamate response was mediated by the NMDA receptor, as the NMDA receptor antagonist MK-801 blocked the CEE-induced potentiation, whereas the L-type calcium channel blocker nifedipine did not. Further, the CEE-potentiated glutamate response was mediated by a src tyrosine kinase, as the tyrosine kinase inhibitor PP2 blocked the potentiation induced by CEE and neurons treated with CEE displayed increased phosphorylated tyrosine. The inhibition by CEE of [Ca(2+)](i) rise in the presence of excitotoxic levels of glutamate was mediated by mitogen activated protein kinase (MAPK), as the protective effect of CEE was blocked by inhibiting MAPK activation with PD98059. These data provide potential mechanisms to explain the cognitive enhancing and neuroprotective effects exerted by ERT.

Neuroactive steroids and central nervous system disorders

Steroid hormones are vital for the cell life and affect a number of neuroendocrine and behavioral functions. In contrast to their endocrine actions, certain steroids have been shown to rapidly alter brain excitability and to produce behavioral effects within seconds to minutes. In this article we direct attention to this issue of neuroactive steroids by outlining several aspects of current interest in the field of steroid research. Recent advances in the neurobiology of neuroactive are described along with the impact of advances on drug design for central nervous system (CNS) disorders provoked by neuroactive steriods. The theme was selected in association with the clinical aspects and therapeutical potentials of the neuroactive steroids in CNS disorders. A wide range of topics relating to the neuroactive steroids are outlined, including steroid concentrations in the brain, premenstrual syndrome, estrogen and Alzheimer's disease, side effects of oral contraceptives, mental disorder in menopause, hormone replacement therapy, Catamenial epilepsy, and neuractive steroids in epilepsy treatment.

Alzheimer's disease through the eye of a mouse. Acceptance lecture for the 2001 Gayle A. Olson and Richard D. Olson prize

There is now ample evidence that beta-amyloid proteins decrease memory. The SAMP8 mouse (P8) develops an early decline in the ability to learn and to retain new information. The studies reviewed here suggest that this is due to overproduction of beta-amyloid. Both antibodies to beta-amyloid and specific antisense to the amyloid precursor protein reverse these deficits in the P8 mouse. This antisense can cross the blood brain barrier. It is hypothesized that the overproduction of beta-amyloid leads to a decline in Delta(9) desaturase activity with an alteration in membrane fatty acids. This results in altered membrane mobility leading to a decline in neurotransmitter activity and a decreased release of acetylcholine. This decreased cholinergic activity results in a decreased ability of the P8 mouse to learn and retain new information.

Do risk factors for Alzheimer's disease predict dementia in Parkinson's disease? An exploratory study

The extent to which concomitant Alzheimer's disease (AD) is etiologically related to the development of dementia in Parkinson's disease (PD) remains controversial. We explored the association of four risk factors associated with AD, including head injury, smoking, hypertension, and diabetes mellitus, with incident dementia in PD. A cohort of 180 nondemented PD patients from the Washington Heights community in northern Manhattan, New York, completed a risk factor questionnaire at baseline and was followed annually with neurological and neuropsychological evaluations. The association of baseline variables with incident dementia was analyzed by using Cox proportional hazards models. All analyses controlled for age at baseline, gender, years of education, duration of PD, and total Unified Parkinson's Disease Rating Scale (UPDRS) motor score at baseline. Of 180 patients (mean age, 71.0 +/- 10.3 years), 52 (29%) became demented during a mean follow-up period of 3.6 +/- 2.2 years. Head injury risk ratio ([RR] 0.9; 95% confidence interval [CI], 0.4-2.2; P = 0.9), hypertension (RR, 0.7; 95% CI, 0.4-1.4, P = 0.3), and diabetes mellitus (RR, 0.8; 95% CI, 0.3-2.3; P = 0.7) were not significantly associated with incident dementia in the Cox models. Patients who reported having ever smoked were at increased risk for the development of dementia compared with nonsmokers (RR, 2.0; 95% CI, 1.0-3.9; P = 0.05). Current smoking was significantly associated with incident dementia (RR, 4.5; 95% CI, 1.2-16.4; P = 0.02), whereas past smoking approached significance (RR, 1.9; 95% CI, 0.9-3.7; P = 0.07). Although an inverse association between smoking and PD has been reported in several studies, our study showed a positive association between smoking and dementia in the setting of PD. The association of smoking with incident dementia in PD deserves further study.

Menopause and perimenopause: the role of ovarian hormones in common neuroendocrine syndromes in primary care

The climacteric and menopause are characterized by erratic fluctuations and decline in ovarian steroid hormones that have broad impact on physical and psychological phenomena leading to a number of clinical syndromes encountered in primary care settings. This endocrine transition is abrupt in women and is not often adequately assessed using objective measures, leading to potential overuse of various medications to treat the physiological and psychological consequences of decline in ovarian hormones. This article reviews such issues and explains how primary care physicians may incorporate the endocrine changes more effectively in their evaluation and treatment of midlife women.