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Categorization and Analysis of Primary Care mHealth Apps Related to Breast Health and Breast Cancer: Systematic Search in App Stores and Content Analysis. JMIR Cancer 2023; 9:e42044. [PMID: 37676704 PMCID: PMC10514767 DOI: 10.2196/42044] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 12/04/2022] [Accepted: 02/22/2023] [Indexed: 02/24/2023] Open
Abstract
BACKGROUND Breast cancer is the most common cause of cancer mortality among women globally. The use of mobile health tools such as apps and games is increasing rapidly, even in low- and middle-income countries, to promote early diagnosis and to manage care and support of survivors and patients. OBJECTIVE The primary objective of this review was to categorize selected mobile health apps related to breast health and prevention of breast cancer, based on features such as breast self-examination (BSE) training and reminders, and to analyze their current dissemination. An ancillary objective was to highlight the limitations of existing tools and suggest ways to improve them. METHODS We defined strict inclusion and exclusion criteria, which required apps to have titles or descriptions that suggest that they were designed for the general public, and not for patients with breast cancer or health workers. Apps that focused on awareness and primary care via self-check were included, while those that focused on topics such as alternative treatments and medical news were excluded. Apps that were not specifically related to breast cancer were also excluded. Apps (in any language) that appeared in the search with keywords were included. The database consisted of apps from AppAgg and Google Play Store. Only 85 apps met the inclusion criteria. Selected apps were categorized on the basis of their alleged interactive features. Descriptive statistics were obtained, and available language options, the number of downloads, and the cost of the apps were the main parameters reviewed. RESULTS The selected apps were categorized on the basis of the following features: education, BSE training, reminders, and recording. Of the 85 selected apps, 72 (84.7%) focused on disseminating breast cancer information. BSE training was provided by only 47% (n=40) of the apps, and very few had reminder (n=26, 30.5%) and recording (n=11, 12.9%) features. The median number of downloads was the highest for apps with recording features (>1000 downloads) than those with education, BSE training, reminder, and recording features (>5000 downloads). Most of these apps (n=74, 83.5%) were monolingual, and around 80.3% (n=49) of these apps were in English. Almost all the apps on Google Play Store were free of charge. CONCLUSIONS Although there exist several apps on Google Play Store to promote awareness about breast health and cancer, the usefulness of most of them appears debatable. To provide a complete breast health package to the users, such apps must have all of the following features: reminders or notifications and symptom recording and tracking. There is still an urgent need to scientifically evaluate existing apps in the target populations in order to make them more functional and user-friendly.
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Can atmospheric pollutants influence menstrual cycle function? ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 257:113605. [PMID: 31806466 DOI: 10.1016/j.envpol.2019.113605] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 11/08/2019] [Accepted: 11/09/2019] [Indexed: 06/10/2023]
Abstract
A few experimental studies suggest that atmospheric pollutants could affect the endocrine system, and in particular stress hormones and the hypothalamic-hypophyseal-ovarian axis, which could in turn influence menstrual cycle function. We aimed to study the possible short-term effects of atmospheric pollutants on the length of the follicular and luteal phases and on the duration of the menstrual cycle in humans. To do so, from a nation-wide study on couples' fecundity, we recruited 184 women not using contraception who collected urine samples at least every other day during one menstrual cycle, from which a progesterone metabolite was assayed, allowing estimation of the duration of the follicular and luteal phases of the cycle. Atmospheric pollution (nitrogen dioxide and particulate matter with an aerodynamical diameter below 10 μm, PM10) levels were estimated from a dispersion model with a 1-km resolution combined with permanent monitoring stations measurements, allowing to estimate exposures in the 30-day, 1-10 and 11-30-day periods before the start of the menstrual cycle. Regression models allowed to quantify the change in cycle duration associated with atmospheric pollutants and adjusted for potential confounders. Follicular phase duration increased on average by 0.7 day (95% confidence interval, CI, 0.2; 1.3) for each increase by 10 μg/m3 in NO2 concentration averaged over the 30 days before the cycle and by 1.6 day (95% CI, 0.3; 2.9) for each increase by 10 μg/m3 in PM10. There was no strong evidence of associations of exposures in this time window with luteal phase or with total menstrual cycle durations (p > 0.2). Exposures in the 1-10 day period before the cycle start were also associated with increased follicular phase duration. This study is one of the first prospective studies to suggest short-term alterations in follicular phase duration following atmospheric pollutants exposure.
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Mechanisms of coronary complications after the arterial switch for transposition of the great arteries. J Thorac Cardiovasc Surg 2013; 145:1263-9. [DOI: 10.1016/j.jtcvs.2012.06.009] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Revised: 05/11/2012] [Accepted: 06/08/2012] [Indexed: 01/22/2023]
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Individual predictions based on nonlinear mixed modeling: application to prenatal twin growth. Stat Med 2012; 31:1986-99. [PMID: 22388672 DOI: 10.1002/sim.5319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2010] [Revised: 12/16/2011] [Accepted: 12/22/2011] [Indexed: 11/07/2022]
Abstract
The assessment of growth during fetal life and childhood commonly relies upon cross'sectional reference ranges or centiles. However, individual sequential predictions may help the timewise assessment of a growth process. In twin pregnancies for example, which are at risk of growth restriction, such predictions may improve the detection of abnormal trajectories. In this article, we present a simple forecasting method, assuming that a given normal individual behaves in the same way as a reference population. We consider, as a prediction in a given individual, the forecast of a future observation conditional to any previous observation and a set of population parameters obtained by nonlinear mixed modeling in a reference population. We suggest an estimator for this prediction without resorting to linear approximation and show that it enjoys interesting asymptotics when the amount of observations increases over time. We use two independent real datasets of twin pregnancies with normal growth and outcome to illustrate the application of such predictions in prenatal growth. We consider the first dataset as a reference dataset and model it using a two'level nonlinear model. We perform illustration and validation of predictions on the second dataset.
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Safety and accuracy of 64-slice computed tomography coronary angiography in children after the arterial switch operation for transposition of the great arteries. JACC Cardiovasc Imaging 2009; 1:331-9. [PMID: 19356445 DOI: 10.1016/j.jcmg.2008.02.005] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2007] [Revised: 02/19/2008] [Accepted: 02/29/2008] [Indexed: 11/29/2022]
Abstract
OBJECTIVES We investigated the accuracy of 64-slice computed tomography (CT) angiography, as compared to invasive angiography, to evaluate reimplanted coronary arteries in children after arterial switch operation (ASO) for transposition of the great arteries (TGA). BACKGROUND Assessment of the integrity of reimplanted coronary arteries is crucial for long-term outcome after ASO for TGA. Noninvasive tests have limited accuracy for detecting significant coronary lesions, and invasive coronary angiography is usually required in this setting. METHODS One hundred thirty consecutive children, after ASO for TGA (age 5.6 +/- 1.1 years), underwent conventional invasive coronary angiography and coronary CT angiography using a 64-slice scanner. The ability of CT to detect significant coronary stenoses (>30% diameter reduction) of the coronary ostia and proximal segments, and other abnormalities of the coronary arteries was analyzed by blinded comparison to the invasive coronary angiogram. RESULTS The CT was fully evaluable in 126 of 130 patients (97%), allowing assessment of ostia and proximal segments of all coronary arteries. The CT correctly detected all 12 patients (9.2%) in whom invasive coronary angiography had identified significant coronary lesions, with a sensitivity, specificity, and negative predictive value of 100%. In addition, CT showed nonsignificant coronary lesions (<30% luminal narrowing) in 6 patients and allowed determination of the underlying reasons for coronary luminal narrowing, such as stretching or compression of the re-implanted coronary arteries caused by their anatomic relationship to the adjacent great vessels. CONCLUSIONS 64-slice CT coronary angiography performs as well as invasive angiography for detecting significant coronary lesions in the majority of children who have undergone the arterial switch procedure for TGA. CT also provides information on the underlying mechanism of coronary luminal narrowing.
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Evaluation of fetal pulmonary vasculature by power Doppler imaging in congenital diaphragmatic hernia. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2004; 23:1011-1017. [PMID: 15284457 DOI: 10.7863/jum.2004.23.8.1011] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
OBJECTIVE To evaluate the feasibility of prenatal power Doppler imaging of pulmonary arteries in congenital diaphragmatic hernia and to study its potential to predict outcome. METHODS A prospective observational study was conducted. Forty-two cases of congenital diaphragmatic hernia (32 left and 10 right) without associated anomalies were analyzed. Qualitative evaluation of pulmonary vasculature was based on power Doppler imaging performed at 26 to 38 weeks. The pulmonary arteries were studied in the lung contralateral to the hernia. Pulmonary Doppler angiography was considered satisfactory when 3 levels of bifurcation defining 3 distinct segments of the pulmonary arteries were imaged and was otherwise considered poor. We also recorded the gestational age at diagnosis, side of the hernia, abdominal circumference below the third percentile, amniotic fluid volume, lung/thoracic area ratio, left/right ventricle ratio, and, in left-sided hernias, stomach position, and we carried out a multivariate analysis to determine the contribution of each factor to predict neonatal mortality. RESULTS More than 3 divisions of the fetal pulmonary arteries were imaged in 20 cases; 1 or 2 divisions or none were imaged in 22. Neonatal mortality was significantly greater when fewer than 3 divisions of the pulmonary arteries were imaged (18 [82%] of 22) than when 3 divisions could be identified on power Doppler imaging (5 [25%] of 20; P = .0005). However, the lung/thoracic area ratio was the only factor that remained significantly associated with mortality in the multivariate analysis. CONCLUSIONS An altered pulmonary power Doppler image is associated with neonatal mortality, but estimation of the lung area remains the best predictor of neonatal outcome.
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[It is not advisable to prescribe hormonal replacement therapy to a woman with proliferative mastopathy with atypia]. GYNECOLOGIE, OBSTETRIQUE & FERTILITE 2002; 30:335-9. [PMID: 12043511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
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Analysis of postpartum lactational amenorrhoea in relation to breast-feeding: some methodological and practical aspects. J Biosoc Sci 2001; 33:529-49. [PMID: 11683223 DOI: 10.1017/s0021932001005296] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A large multicentre epidemiological study was carried out by WHO between 1991 and 1995 to analyse the duration of lactational amenorrhoea in relation to breast-feeding. The main results of this analysis, which used classical statistical modelling, have been already published. However, some specific aspects of the postpartum fertility amenorrhoea and breast-feeding covariates, and more specifically the observed progressive exhaustion of the breast-feeding inhibitory effect on the reproductive axis, may justify a closer look at the validity of the statistical tools. Indeed, as has already been emphasized, analysis of large longitudinal data sets in reproduction often faces three difficulties: (i) the precise determination of the event of interest, (ii) the way to handle the time evolution of both the studied variables and their effect on the event of interest and (iii) the often discrete nature of the data and the associated problem of tied events. The first objective of the present work was to give additional insights into the estimation and quantification of the dynamics of the effect of breast-feeding over time, considering this covariate either as fixed or time-dependent. The second objective was to show how to perform the analyses using corresponding adapted procedures in widely available statistical packages, without the need for acquiring particular programming skills.
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Resumption of luteinizing hormone pulsatility and hypogonadotropic hypogonadism after endoscopic ventriculocisternostomy in a hydrocephalic patient. Fertil Steril 2001; 76:390-3. [PMID: 11476794 DOI: 10.1016/s0015-0282(01)01877-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
OBJECTIVE To study gonadotropin pulsatility before and after surgical cure of hydrocephalus. DESIGN Case report. SETTING Department of Endocrinology and Centre d'Investigations Cliniques, Necker Hospital, Paris, France. PATIENT(S) A 29-year-old woman who presented with secondary amenorrhea. INTERVENTION(S) The patient underwent an endoscopic ventriculocisternostomy that led to restoration of normal menses and resolution of hypogonadism. MAIN OUTCOME MEASURE(S) A gonadotropin pulse study was performed before and 2 and 5 months after surgery. RESULT(S) No LH pulse was observed before surgery. Emergence of pulsatility was observed 2 months after surgery, and pulses became clearly individualized after 5 months. CONCLUSION(S) This observation strongly suggests that amenorrhea, in case of chronic hydrocephalus, is indeed due to a hypothalamic dysfunction of the GnRH pulse generator.
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Abstract
OBJECTIVE To study the potential for prenatal magnetic resonance imaging to predict pulmonary hypoplasia in congenital diaphragmatic hernia. DESIGN Prospective observational study. SETTING Tertiary care centre. PARTICIPANTS Thirteen cases of congenital diaphragmatic hernia (11 left, 2 right) without associated anomalies and 74 controls. METHODS Measurements by magnetic resonance imaging of fetal lung volume were achieved. In the control fetuses, a regression analysis was performed to associate fetal lung volume with gestational age. This yielded a formula allowing calculation of the expected fetal lung volume as a function of gestational age. In the cases with congenital diaphragmatic hernia, the observed/expected fetal lung volume ratio was compared with perinatal outcome. MAIN OUTCOME MEASURES Neonatal mortality and pulmonary hypoplasia, which was defined as lung/body weight ratios less than 0.012. RESULTS The expected fetal lung volume was derived from the following formula: Fetal lung volume (mL) = exp (1.24722 + 0.08939 x gestational age in weeks). The observed/expected fetal lung volume ratio was significantly lower in congenital diaphragmatic hernia (median: 0.31, range: 0.06-0.63), than in controls (median: 0.99, range: 0.42-1.94). This ratio was significantly less in the infants with congenital diaphragmatic hernia who died (median: 0.26, range: 0.06-0.63) compared with those who survived (median: 0.46, range: 0.35-0.56). The observed: expected fetal lung volume ratio was significantly correlated with the post mortem lung: body weight ratio. CONCLUSION In isolated congenital diaphragmatic hernia, fetal lung volume measurement by magnetic resonance imaging is a potential predictor of pulmonary hypoplasia and postnatal outcome. Further studies are required to establish the clinical value of magnetic resonance imaging for the prenatal assessment of fetal lungs.
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Abstract
During the terminal part of their development, ovarian follicles become totally dependent on gonadotropin supply to pursue their growth and maturation. Both gonadotropins, follicle-stimulating hormone (FSH) and luteining hormone (LH), operate mainly through stimulatory G protein-coupled receptors, their signal being transduced by the activation of the enzyme adenylyl cyclase and the production of second-messenger cAMP. In this paper, we develop a mathematical model of the dynamics of the coupling between FSH receptor stimulation and cAMP synthesis. This model takes the form of a set of nonlinear, ordinary differential equations that describe the changes in the different states of FSH receptors (free, bound, phosphorylated, and internalized), coupling efficiency (activated adenylyl cyclase), and cAMP response. Classical analysis shows that, in the case of constant FSH signal input, the system converges to a unique, stable equilibrium state, whose properties are here investigated. The system also appears to be robust to nonconstant input. Particular attention is given to the influence of biologically relevant parameters on cAMP dynamics.
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Screening for Down syndrome using first-trimester ultrasound and second-trimester maternal serum markers in a low-risk population: a prospective longitudinal study. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2001; 18:26-31. [PMID: 11489221 DOI: 10.1046/j.1469-0705.2001.00457.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
OBJECTIVES To compare nuchal translucency and second-trimester maternal serum measurements as alternative methods of antenatal screening for Down syndrome in a low-risk population and to evaluate the consequence of combining the results in the estimation of risk. DESIGN In a consecutive series of 4130 women aged less than 38 years with a singleton pregnancy, we examined both the detection rate of Down syndrome by nuchal translucency measurement at 10-14 weeks and maternal serum screening by human chorionic gonadotrophin and alpha-fetoprotein at 14-18 weeks. Women with a nuchal translucency measurement of > or = 3 mm and women with a maternal serum screening-derived risk > or = 1/250 were recommended to have amniocentesis. A second-trimester detailed ultrasound scan was also performed in all women. The outcome of all pregnancies was recorded prospectively and the detection rate and false-positive rate of different screening strategies were retrospectively analyzed. RESULTS Out of the 4130 pregnancies that were followed (mean maternal age, 30.1 years), 12 cases of Down syndrome were observed (0.28%), all detected prenatally. Seven of 12 cases had a nuchal translucency measurement of > or = 3 mm (58%), and six out of 10 cases with available maternal serum screening had a calculated risk of > or = 1/250 (60%). Four of the five Down syndrome cases with a nuchal translucency measurement of < 3 mm were detected by subsequent maternal serum screening. At a threshold giving 5% of positive tests, the sensitivity of nuchal translucency, maternal serum screening and combined risk screening were 75%, 60% and 90%, respectively. CONCLUSIONS In screening for Down syndrome, an approach which combines the results from first-trimester nuchal translucency and second-trimester biochemistry is effective and increases the detection rate compared to the use of any single test. However, this strategy is likely to raise the false-positive rate and the interpretation of maternal serum screening-derived risk should be combined with the first-trimester nuchal translucency measurement.
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Abstract
Evidence in favour of an association of breastfeeding with a breast cancer risk reduction remains limited and inconsistent. To evaluate the relation between breastfeeding and breast cancer, a meta-analysis based on a review of the literature was carried out, using as variables ever/never breastfeeding and duration of breastfeeding. Menopausal status at the time of diagnosis of breast cancer was considered to be a potential effect modifier. Only case-control studies could be included in the final analysis. A slight but significant decreased risk of breast cancer was observed in ever breastfeeding, compared with never breastfeeding parous women, using both the fixed and random-effect models. This decrease was more pronounced in non-menopausal women at the time of diagnosis of breast cancer and in long-term breastfeeding women. Hence, breastfeeding appeared to be a protective factor but was of small magnitude compared with other known risk factors for breast cancer. Whether this result should imply a modification in the attitude of both health care providers and women towards breastfeeding, which represents one of the few identified protective factors which is under the control of the mother, and is thus (theoretically) modifiable, remains questionable.
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[Oral contraception and genetic factors in breast cancer: characteristics and limits of case-only studies]. Rev Epidemiol Sante Publique 2000; 48:294-303. [PMID: 10891789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
The analysis of the interaction between environmental and genetic factors is a matter of increasing interest in cancerology. More particularly the discovery of the BRCAx family and the high cumulated incidence of familial breast cancers related to mutations of these proteins raised the issue of the differential effect of long term and/or early exposure to oral contraceptives in the presence of these mutations. The classical case-control design assumes the presence of a control group, which can be sometimes difficult to obtain from both the technical and ethical points of view. Case-only or case-case studies, which are based only on series of cases, making them apparently attractive, have been proposed to analyze more specifically the interaction term. The aim of the present paper is to review and discuss the methodological basis and main assumptions of the case-only design, and their applicability to breast cancer studies. The measure of the interaction between an environmental factor and a susceptibility genetic factor differs in an important aspect from the measure of the association between an environmental factor and a acquired tumoral genetic factor; this aspect is reminded.
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Ketamine-induced general anesthesia is compatible with gonadotropin-releasing hormone pulse generator activity in gonadectomized rats: prospects for detailed electrophysiological studies in vivo. Brain Res 1999; 841:197-201. [PMID: 10547003 DOI: 10.1016/s0006-8993(99)01820-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Previous studies on the mediobasal hypothalamus (MBH) of rats, rhesus monkeys and goats have detected episodic increases in multiunit activity (MUA volleys) which immediately precede a pulse of luteinizing hormone (LH). These volleys are considered to reflect the activity of the gonadotropin-releasing hormone (GnRH) pulse generator. Our understanding of this system would be greatly enhanced if it were possible to study the electrophysiological aspects of this system at the single cell level; such an approach requires anesthesia of the animals (as in the classic studies on the oxytocin and vasopressin systems). Although it is widely held that anesthetic agents disrupt the processes regulating LH release, little is known about their specific effects on the dynamics of this system. Using on-line electrophysiological techniques in addition to subsequent radioimmunoassay for LH, we have found that anesthesia by ketamine is compatible with the continued production of MUA volleys and LH pulses in gonadectomized rats. In contrast to the hypothermia induced by the LH pulse-suppressing anesthetic sodium pentobarbitone, a small rise in core temperature occurs following ketamine. The present findings offer the prospect of detailed electrophysiological analysis of GnRH pulse generator activity in rats maintained under general anesthesia.
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Percutaneous progesterone use and risk of breast cancer: results from a French cohort study of premenopausal women with benign breast disease. CANCER DETECTION AND PREVENTION 1999; 23:290-6. [PMID: 10403900 DOI: 10.1046/j.1525-1500.1999.99032.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Percutaneous progesterone topically applied on the breast has been proposed and widely used in the relief of mastalgia and benign breast disease by numerous gynecologists and general practitioners. However, its chronic use has never been evaluated in relation to breast cancer risk. The association between percutaneous progesterone use and the risk of breast cancer was evaluated in a cohort study of 1150 premenopausal French women with benign breast disease diagnosed in two breast clinics between 1976 and 1979. The follow-up accumulated 12,462 person-years. Percutaneous progesterone had been prescribed to 58% of the women. There was no association between breast cancer risk and the use of percutaneous progesterone (RR = 0.8; 95% confidence interval 0.4-1.6). Although the combined treatment of oral progestogens with percutaneous progesterone significantly decreased the risk of breast cancer (RR = 0.5; 95% confidence interval 0.2-0.9) as compared with nonusers, there was no significant difference in the risk of breast cancer in percutaneous progesterone users versus nonusers among oral progestogen users. Taken together, these results suggest at least an absence of deleterious effects caused by percutaneous progesterone use in women with benign breast disease.
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[Hereditary risks of breast cancer. Interaction of genetic factors and hormonal factors]. ANNALES D'ENDOCRINOLOGIE 1999; 59:465-9. [PMID: 10189989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
The association between risk of breast cancer and familial risk is well documented. The first observation was described by Paul Broca around 1850 from his own family. Germinal mutations have been estimated to account for 5 to 10% of breast cancer cases. However, some questions remains unclear in this context of a multifactorial disease. Even if the rise in breast cancer risk associated with BRCAx mutations is well established, the place of a genetic factor among other factors risks of breast cancer remains unclear. The interaction between genetic, environmental and hormonal factors is an important problem. More particularly the effect of oral contraceptives and hormonal replacement therapy in women with or without hereditary susceptibility of breast cancer needs to be addressed.
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Abstract
Analysis and characterization of neuronal discharge patterns are of interest to neurophysiologists and neuropharmacologists. In this paper we present a hidden Markov model approach to modeling single neuron electrical activity. Basically the model assumes that each interspike interval corresponds to one of several possible states of the neuron. Fitting the model to experimental series of interspike intervals by maximum likelihood allows estimation of the number of possible underlying neuron states, the probability density functions of interspike intervals corresponding to each state, and the transition probabilities between states. We present an application to the analysis of recordings of a locus coeruleus neuron under three pharmacological conditions. The model distinguishes two states during halothane anesthesia and during recovery from halothane anesthesia, and four states after administration of clonidine. The transition probabilities yield additional insights into the mechanisms of neuron firing.
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[Importance of ultradian rhythms in endocrinology]. PATHOLOGIE-BIOLOGIE 1996; 44:585-91. [PMID: 8977915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Biological rhythms have been reported for a long time in endocrinology. However, their real study started in the late 60's when the possibility of repeatedly measuring the hormonal signal directly in blood over extended periods of time became available. Although episodic secretory fluctuations have been reported for the majority of hormones, and more specifically peptidic hormones, in mammals, organised secretory episodes on a regular or quasi-regular ultradian basis are less common. Their importance, which is directly connected to the number and the processing of the corresponding receptors on the target cells, is illustrated by the paradigm of the pulsatile release of the gonadotropin hormones. Hormonal ultradian rhythms should be considered both from the nosological and therapeutical point of view.
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Insulin-induced hypoglycemia decreases luteinizing hormone secretion in the castrated male rat: involvement of opiate peptides. Neuroendocrinology 1996; 64:49-56. [PMID: 8811666 DOI: 10.1159/000127097] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Insulin-induced hypoglycemia (IIH) has been reported to inhibit luteinizing hormone (LH) secretion in ovariectomized ewes as well as in intact or gonadectomized female rhesus monkeys. An infusion of naloxone, a specific opiate receptor antagonist, while able to prevent this inhibitory effect in ewes, was ineffective in monkeys, suggesting a difference in the mechanisms involved in the response to IIH in these two species. The present study was designed to investigate the influence of this stimulus on the dynamics of LH release and the possible activation of an opioidergic pathway in the long-term castrated male rat. Blood samples were collected every 7 min, for several hours, in freely-moving rats bearing a jugular cannula. The intravenous injection of 0.4 IU of insulin triggered an acute hypoglycemia and reduced LH release. In contrast, during a continuous intravenous naloxone infusion (0.5 mg/kg/h), insulin, while still lowering the glycemia, failed to affect the LH secretory pattern. In a control experiment, naloxone infusion alone had no significant effect on mean LH concentration and pulse intervals. These experiments indicate that, in long-term gonadectomized male rats, IIH impairs the LH secretory pattern, and that endogenous opioid peptides are involved in this response.
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Combined curative radiation therapy alone in (T1) T2-3 rectal adenocarcinoma: a pilot study of 29 patients. Radiother Oncol 1996; 38:131-7. [PMID: 8966225 DOI: 10.1016/0167-8140(95)01673-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
AIM Analysis of a pilot study including 29 consecutive patients with high surgical risk or refusal of colostomy treated with radiation therapy alone with curative intent. PATIENTS Between 1986 and 1992, 29 patients were treated for infiltrating adenocarcinoma of the rectum. Median age was 72 years. Transrectal ultrasound staging was used in 24 patients (T1, 2; T2, 14; T3, 13; N0, 23; N1, 6). In 20 patients the lower border of the tumor was at 5 cm or less from the anal verge and in 19 patients the diameter exceeded 3 cm. CEA was elevated in seven cases. TREATMENT Contact X-ray (50 kV) was given first (70 Gy/3 fractions). External beam radiation therapy used a three-field technique in the prone position. Accelerated schedule (39 Gy/13 fractions/17 days) with a concomitant boost "field within the field' (4 Gy/4 fractions). Six weeks later an iridium-192 implant was performed in 21 (20 Gy/22 h). RESULTS Median follow-up time was 46 months. Overall and specific survival at 5 years was 68% (SE = 0.09) and 76% (SE = 0.08). Local control was obtained in 21/29 patients (72%). There was one grade 2 rectal bleeding and five grade 2 rectal necroses. The overall tolerance was good in these frail patients. DISCUSSION For T2. T3 or T1 > 3 cm diameter rectal adenocarcinoma, where contact X-ray alone is not recommended, a combined treatment with radiation therapy alone is able to give good local control with acceptable toxicity. This treatment should be restricted to inoperable patients.
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Abstract
Using chronically implanted microelectrodes, multiunit electrical activity (MUA) was recorded from the arcuate nucleus of freely moving gonadectomized male rats. Intermittent increases in MUA activity (MUA volleys) closely associated with luteinizing hormone pulses measured in the peripheral circulation were observed, which confirms that this experimental approach can be used for monitoring the activity of the gonadotropin-releasing hormone-associated hypothalamic pulse generator in the male rat. The mean MUA volley frequency was 22.2 min (range 13-38 min), whereas the mean MUA volley duration was 2.7 +/- 0.8 min (standard deviation). In addition to a large inter-individual variability. MUA volley intervals also showed an important intra-individual variability. This observation suggests that, beside the mean frequency of pulse generator activation, the degree of variability in gonadotropin-releasing hormone-associated pulse generator activity might be an additional relevant parameter in the characterization of the reproductive function in the male rat.
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Stochastic modeling of the hypothalamic pulse generator activity. THE AMERICAN JOURNAL OF PHYSIOLOGY 1994; 267:E795-800. [PMID: 7977733 DOI: 10.1152/ajpendo.1994.267.5.e795] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Luteinizing hormone (LH) is released by the pituitary in discrete pulses. In the monkey, the appearance of LH pulses in the plasma is invariably associated with sharp increases (i.e, volleys) in the frequency of the hypothalamic pulse generator electrical activity, so that continuous monitoring of this activity by telemetry provides a unique means to study the temporal structure of the mechanism generating the pulses. To assess whether the times of occurrence and durations of previous volleys exert significant influence on the timing of the next volley, we used a class of periodic counting process models that specify the stochastic intensity of the process as the product of two factors: 1) a periodic baseline intensity and 2) a stochastic regression function with covariates representing the influence of the past. This approach allows the characterization of circadian modulation and memory range of the process underlying hypothalamic pulse generator activity, as illustrated by fitting the model to experimental data from two ovariectomized rhesus monkeys.
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Progestogen use and decreased risk of breast cancer in a cohort study of premenopausal women with benign breast disease. Br J Cancer 1994; 70:270-7. [PMID: 8054275 PMCID: PMC2033511 DOI: 10.1038/bjc.1994.291] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
A cohort study of 1,150 premenopausal French women with benign breast disease diagnosed in two breast clinics between 1976 and 1979 was carried out to analyse the relationship between progestogen use and the risk of breast cancer. The follow-up accumulated 12,462 person-years. The risk of breast cancer was estimated using a Poisson regression analysis on person-time data and the proportional hazards model. In the latter analysis, cumulated progestogen use and age were considered as time-varying covariables and adjustment was performed on the main risk factors for breast cancer. Neither overall progestogen use nor the duration of use was found to be significantly associated with the risk of breast cancer. When progestogens were classified into two categories according to their hormonal potency (19-nortestosterone derivatives vs other progestogens), 19-nortestosterone derivative use was found to be significantly associated with a lower risk of breast cancer. In the adjusted model, the corresponding risk of breast cancer was 0.48 (95% confidence interval 0.25-0.90). In addition, there was a linear trend in the decrease of the relative risk of breast cancer with the duration of use (P = 0.02). These results do not support the hypothesis that progestogens might increase the breast cancer risk. They suggest, instead, that treatment with 19-nortestosterone derivatives might have a beneficial effect on the risk of breast cancer in women with benign breast disease.
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Age-related changes of the population of human ovarian follicles: increase in the disappearance rate of non-growing and early-growing follicles in aging women. Biol Reprod 1994; 50:653-63. [PMID: 8167237 DOI: 10.1095/biolreprod50.3.653] [Citation(s) in RCA: 260] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The effect of aging on the number of non-growing follicles (NGF) and early-growing follicles (EGF) was studied in humans through use of a database obtained by pooling two subsets of ovarian pairs (2 x 43 pairs) collected in two distinct populations. A previously suggested model of exponential regression of NGF counts in relation to the subject's age was tested but did not adequately fit the observed data points. This lack of fit is attributable mainly to the existence of a significant relation between a woman's age and the corresponding NGF count decay rate. Consequently, various regression models were tested. Two different periods of decay rate were observed for each population of small follicles. The first corresponds to younger ages with a decay rate that is slow for both types of follicles, although faster for NGF than for EGF. The second period corresponds to older ages with an accelerated decay rate that appears similar for NGF and EGF. The changing points were found at 38.0 +/- 2.4 and 39.0 +/- 1.9 yr (mean +/- SD) for NGF and EGF, respectively. Extrapolation of the fitted model suggested the presence of approximately 402,000 healthy NGF per ovary at birth and a total exhaustion of the follicular stock at around 74 yr of age. These results support the view that depletion of the NGF pool is caused mainly by atresia in younger women but mainly by entrance of NGF into the growing pool in older women. The mechanisms triggering accelerated entrance into the growth phase of NGF are discussed in relation to the previously reported increase in FSH plasma levels that starts in the late thirties, approximately, and precedes the menopausal period by several years.
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26
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[Adjuvant treatments in digestive cancers. General principles]. GASTROENTEROLOGIE CLINIQUE ET BIOLOGIQUE 1994; 18:710-713. [PMID: 7875438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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27
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[Socioeconomic stakes of menopause: evaluation of the cost-effectiveness studies]. LA REVUE DU PRATICIEN 1993; 43:2665-9. [PMID: 8146568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The extension of hormonal replacement therapy to all women after their menopause as a preventive action is becoming a major public health issue. Cost-effectiveness analysis represents an appropriate tool to address the economical aspects of this issue. Out of the 3 studies reported in the past recent years on this topic, the Oxford Hormone Therapy Group study is the only one to take into account all possible outcomes of the hormonal replacement therapy. Its conclusions, however, cannot be extended directly to other countries, as the hormonal replacement therapy may differ in many aspects, like: 1) the chemical nature, metabolism and mode of administration of the hormones used, both as regard the oestrogen component and the progestative one; 2) the acceptability of the therapy in relation to its side effects; 3) the age-specific morbi-mortality data in relation to hip fractures, breast cancer and cardiovascular diseases.
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Abstract
In the course of previous studies using continuous monitoring of the electrophysiological correlates of GnRH pulse generator activity, characterized by episodic increases in hypothalamic multiunit electrical activity (MUA volley), it was noticed that the nocturnal slowing of pulse generator frequency was an acute phenomenon observable in the first MUA volleys after the lights were turned off, as was the increase in frequency when the lights were turned on in the morning. This suggested that the reduction in pulse generator frequency at night may not be the consequence of an intrinsic diurnal rhythm, but an effect of light per se. Indeed, as reported herein, such an effect was observed when the lights were turned on or off at times other than the normal illumination period (normal light schedule, lights on from 0700-1900 h). That this was not simply a response to arousal was shown by awakening the animals with loud recorded noises in total darkness at the same unaccustomed times without a resulting change in frequency. This suggests that the effect of light is specific, perhaps mediated by the retino-hypothalamic tract. This direct action of light, however, is superimposed upon a diurnal rhythm, as shown by a reduction in pulse generator frequency during the subjective night when the monkeys were kept in constant light or constant darkness.
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Ovarian control of gonadotropin hormone-releasing hormone pulse generator activity in the rhesus monkey: duration of the associated hypothalamic signal. Neuroendocrinology 1993; 57:588-92. [PMID: 8367027 DOI: 10.1159/000126411] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The activity of the GnRH pulse generator in the rhesus monkey is associated with abrupt increases in multiunit electrical activity (MUA) volleys recorded from the mediobasal hypothalamus that precede each pulse of LH in the peripheral circulation. In long-term ovariectomized animals the duration of these MUA volleys is 10-25 min and consists of a brief initial 'overshoot' followed by a plateau phase that ends in a rapid decline to baseline activity. In intact monkeys, however, the MUA volley lasts only 1-3 min, a duration equivalent to the overshoot in ovariectomized animals. In addition, the maximal frequency of neuronal activity during each MUA volley is reduced in normal animals when compared to castrates. As shown in earlier studies, estradiol given to ovariectomized monkeys causes a reduction in the duration of MUA volleys to that characteristic of intact animals within 3-5 h. In contrast to this acute effect of estradiol, the increase in MUA volley duration following ovariectomy is a gradual phenomenon, 4-6 weeks being required to achieve the MUA volley duration observed in long-term ovariectomized monkeys. A similar slow time course was observed for the increase in maximal neuronal frequency during each MUA volley. This protracted effect of ovariectomy on MUA volley duration and firing rate may be the consequence of hypothalamic remodelling but this consideration must be tempered by the observation that estradiol reverses these phenomena within hours.
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[Presentation of results of a general review]. ANNALES DE MEDECINE INTERNE 1993; 144:282-289. [PMID: 8368722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Effects of naloxone on estrogen-induced changes in hypothalamic gonadotropin-releasing hormone pulse generator activity in the rhesus monkey. Neuroendocrinology 1993; 57:115-9. [PMID: 8479607 DOI: 10.1159/000126349] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
In the ovariectomized rhesus monkey, estradiol (E2) markedly reduces the frequency of the GnRH pulse generator as monitored by LH pulse frequency and the concurrent changes in hypothalamic electrical activity, an action mimicked by morphine. In addition, the duration of the increments in multiunit electrical activity (MUA volleys) that precede each LH pulse is decreased by estrogen administration, an action also shared by morphine. The role of endogenous opioids in these actions of E2 was investigated in 8 ovariectomized animals restrained in primate chairs. They were fitted with indwelling cardiac catheters and with bilateral arrays of recording electrodes chronically implanted in the mediobasal hypothalamus. Physiological serum E2 levels achieved by subcutaneous implantation of E2-containing Silastic capsules increased MUA volley interval from 50.8 +/- (SEM) 1.6 min in the control period to 81.1 +/- 6.2 min following E2. Mean MUA volley duration decreased from 21.9 +/- 1.0 to 13.0 +/- 0.7 min. The placement of empty Silastic capsules had no effect on MUA volley duration or interval. Naloxone administration (2.5 mg bolus followed by a 1 mg/h infusion lasting 4-8 h) completely (n = 4) or partially (n = 2) blocked the effects of E2 on MUA volley interval in 6 of the 8 monkeys, and was without effect in the remainder. In contrast, however, naloxone had little or no effect on the action of E2 on MUA volley duration, (13.0 +/- 0.7 vs. 14.0 +/- 0.9 min). These findings suggest that the inhibitory action of E2 on GnRH pulse generator frequency, like that of all other gonadal steroids studied to date, may be mediated by endogenous opioids.(ABSTRACT TRUNCATED AT 250 WORDS)
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Abstract
The identification of discrete hormonal secretory pulses is of critical importance in clinical endocrinology. Pulses are defined as sudden increases in hormone concentration followed by exponential decay. We propose a model-based iterative procedure for pulse detection in pulsatile hormone time series. Our model is seen to be analogous to the model for innovation outliers in autoregressive series, and outlier detection techniques for pulse identification are adapted to the endocrine context. An original feature of the procedure is that it distinguishes between true pulses and gross observation outliers in the series. Simulation experiments are used to investigate the behaviour of the method under physiologically or clinically relevant circumstances. Five experimental endocrine series from rhesus monkeys, where the times of the pulses are known from the concomitant recording of the electrical activity of the hypothalamus, are analysed.
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Abstract
The female reproductive axis in mammals is a highly complex dynamic system which goes through different transient or absorbent states during the course of a life-time. Little is known about the mechanisms controlling this system during fetal life and at birth, although it has been shown in numerous species, including primates, that the whole machinery is already functioning (Brooks et al., 1990; Plant, 1986). After a delay ranging from a few days to a few weeks, according to the species, the reproductive axis becomes quiescent and activity apparently resumes only at the time of puberty. Here again understanding of the phenomenon is still limited (Ojeda, 1991).
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Cyclical mastalgia as a marker of breast cancer susceptibility: results of a case-control study among French women. Br J Cancer 1992; 65:945-9. [PMID: 1616869 PMCID: PMC1977766 DOI: 10.1038/bjc.1992.198] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
A matched case-control study in a population of urban, non-menopaused women living in Paris was performed between 1983 and 1985 to investigate the risk of breast cancer (BC) in relation to various factors with a particular interest in the effect of the use of oral contraceptive (OC) and the existence of cyclical mastalgia (CM). Two hundred and ten non-menopaused women, less than 45 years old, with newly diagnosed BC were compared to 210 controls from the same geographic area matched on year of birth, age, education level and age at first full term pregnancy (FFTP), when justified. The adjusted Relative Risk of BC (RRa) was significantly increased for a total duration of OC use longer than 72 months (RRa 2.80; 95% CI 1.56-5.01), as well as the RRa for OC use above 48 months before FFTP (3.26 95% CI 1.37-7.76) and, to a lesser extent, the RRa for OC use above 48 months after FFTP (2.02 95% CI 1.07-3.84) respectively. Adjustment was performed on familial history of BC, personal history of Benign Breast Disease (BBD), age at menarche. A previous history of cyclical mastalgia was found to be associated with an increased risk of BC. The significant increase remained after adjustment on the previously mentioned confounding factors and OC use: RRa 2.12; 95% CI (1.31-3.43). Under a precise definition related to the hormonal environment, mastalgia appear to be an interesting marker of breast cell susceptibility, the importance of which can only be validated by prospective studies.
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Abstract
Fertility was evaluated in 53 female patients with late-onset adrenal hyperplasia (LAH) due to 21-hydroxylase deficiency. The majority of patients (n = 33) were seen for isolated postpubertal hirsutism, 9 patients consulted for sterility, and 11 for irregular menstrual cycles. At the time of diagnosis, the ages of patients ranged from 15-40 yr (mean +/- SD, 24.6 +/- 5.2). No patient had major signs of virilization. The plasma 17-hydroxyprogesterone level was higher than normal in all patients (26.8 +/- 18.9 nmol/L; range, 3.4-139.4) and dramatically increased to 140.1 +/- 80.6 nmol/L (range, 35.2-324.2) after ACTH treatment. Plasma androgen levels were high (testosterone, 3.25 +/- 2.03 nmol/L; delta 4-androstenedione, 13.65 +/- 5.60 nmol/L). Plasma basal and LHRH-stimulated values were normal for FSH and high for LH. Basal and TRH-stimulated plasma PRL levels were normal. Among these 53 LAH patients, only 20 desired a pregnancy. These had a total of 38 pregnancies. Ten patients became pregnant before the diagnosis of LAH and without any treatment; they had a total of 18 pregnancies, 12 of which were successful. Moreover, 19 normal pregnancies without any spontaneous abortion were carried to term by 14 of 16 hydrocortisone-treated patients. One patient needed the association of one cure of clomiphene citrate. Hypofertility in LAH patients seems, therefore, to be relative. Its mechanism is hormonal, with anovulation or dysovulation, due to the continuous steroid feedback of adrenal origin on the hypothalamo-pituitary axis. Hydrocortisone is the appropriate treatment in most cases, reducing adrenal androgen overproduction and relieving hypothalamic-pituitary gonadotropin function, thereby making possible cyclic ovarian activity and ovulations.
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Radiotelemetric monitoring of hypothalamic gonadotropin-releasing hormone pulse generator activity throughout the menstrual cycle of the rhesus monkey. Endocrinology 1991; 129:1207-14. [PMID: 1874166 DOI: 10.1210/endo-129-3-1207] [Citation(s) in RCA: 92] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Continuous monitoring of the electrophysiological manifestations of GnRH pulse generator activity was achieved by radiotelemetry throughout the menstrual cycles of unrestrained rhesus monkeys. The characteristic increases in hypothalamic multiunit activity (MUA volleys) associated with each LH pulse measured in the peripheral circulation were of lower frequency during the luteal phase than in the follicular phase of the cycle. Multiunit activity volley frequency increased as functional luteolysis progressed and achieved maxima of approximately one volley per hour within the first few days of the follicular phase. Unexpectedly, a dramatic decline in pulse generator frequency was observed coincidentally with the initiation of the preovulatory LH surge. Evidence is presented to support the conclusion that this deceleration of pulse generator activity is the consequence of the preovulatory rise in plasma estrogen concentration. As reported in women, a significant reduction in GnRH pulse generator frequency was observed at night during the follicular phase, but not during the luteal phase, of the menstrual cycle.
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Effects of gonadotrophin releasing hormone antagonist and agonist on the pulsatile release of gonadotrophins and alpha-subunit in postmenopausal women. Clin Endocrinol (Oxf) 1991; 34:477-83. [PMID: 1716186 DOI: 10.1111/j.1365-2265.1991.tb00328.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
OBJECTIVE The present study was designed to further assess the mechanism of action of GnRH and GnRH analogues. DESIGN AND PATIENTS Both the Nal-Glu GnRH antagonist and the D-Trp6 GnRH agonist were administered sequentially to nine normal, post-menopausal women. MEASUREMENTS A baseline study of pulsatile LH, FSH and free alpha-subunit secretion was performed, with sampling every 10 min for 8 h, and then repeated 8 h after a single subcutaneous injection of Nal-Glu GnRH antagonist (5 mg). Sampling was repeated 21 days after the intramuscular injection of a depot preparation of D-Trp6 GnRH (3.75 mg) in the same women. RESULTS The baseline sampling period showed synchronous pulses of LH and free alpha-subunit. The antagonist Nal-Glu decreased plasma LH (71%) and free alpha-subunit (43%). However, with the single dose of 5 mg, pulsatile LH and free alpha-subunit release were not completely suppressed and remained temporally correlated. The GnRH agonist had a potent inhibitory action on plasma immunoreactive LH (IRMA) (93%). In contrast, it increased the mean plasma levels of free alpha-subunit from 1.66 +/- 0.01 to 5.06 +/- 0.02 micrograms/l (205%). The pulsatile secretory patterns of both LH and free alpha-subunit were abolished by the agonist. Immunoreactive FSH levels were decreased by the antagonist (24%) and suppressed by the agonist (93%). CONCLUSIONS The pulsatile study confirms the different mechanism of action of GnRH analogues. Following antagonist administration, low amplitude free alpha-subunit pulses persist and are synchronous with residual LH pulses. In contrast, LH and free alpha-subunit are not maintained under agonist treatment. These data provide evidence for the differential regulation of LH and free alpha-subunit by GnRH.
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Duration of phasic electrical activity of the hypothalamic gonadotropin-releasing hormone pulse generator and dynamics of luteinizing hormone pulses in the rhesus monkey. Proc Natl Acad Sci U S A 1990; 87:8580-2. [PMID: 2236069 PMCID: PMC55000 DOI: 10.1073/pnas.87.21.8580] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The secretion of luteinizing hormone (LH) by the pituitary gland is a pulsatile phenomenon. In the rhesus monkey, each pulse of LH in the peripheral circulation is associated with a characteristic increase in multiunit electrical activity (MUA) recorded from the medial basal hypothalamus. These "volleys" of electrical activity initiate the release of gonadotropin-releasing hormone (GnRH) into the pituitary portal circulation from the terminals of neurosecretory cells. Their duration varies from 1-3 min in normal, adult intact females to 10-25 min in long-term ovariectomized monkeys. A variety of pharmacological interventions also modify volley duration. The purpose of this investigation was to determine the physiological significance of alterations in volley duration. The dynamics of LH pulses in ovariectomized animals were observed in a number of experimental circumstances in which MUA volley duration was reduced from a maximum of 23 min to a minimum of 4 min without significantly altering their frequency. The magnitude of each LH pulse was assessed by calculating the area under the curve delineated by the time course of LH above baseline. In eight experiments, a linear regression of these values on volley duration failed to reveal a significant correlation between MUA volley duration and the magnitude of LH pulses. These results suggest that all of the GnRH secreted per pulse is released at the onset of each MUA volley, the remainder of the increase in electrical activity having no further action on GnRH secretion, although effects on other systems cannot be excluded.
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Duration and frequency of multiunit electrical activity associated with the hypothalamic gonadotropin releasing hormone pulse generator in the rhesus monkey: differential effects of morphine. Neuroendocrinology 1990; 52:225-8. [PMID: 2120605 DOI: 10.1159/000125590] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The effects of morphine on the frequency and duration of the characteristic bursts or 'volleys' of multiunit electrical activity (MUA) associated with pulsatile pituitary luteinizing hormone (LH) secretion were studied in unanesthetized ovariectomized rhesus monkeys bearing bilateral arrays of electrodes implanted in the mediobasal hypothalamus. Morphine administration resulted in a dose-dependent decrease in MUA volley duration and frequency. When morphine was infused at 10 micrograms/kg/h, the inhibiting effect on volley duration was observed without a change in volley frequency. It is concluded that the frequency and duration of hypothalamic MUA volleys associated with pulsatile LH secretion may be independently regulated.
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Corticotropin-releasing factor and gonadotropin-releasing hormone pulse generator activity in the rhesus monkey. Electrophysiological studies. Neuroendocrinology 1990; 52:133-7. [PMID: 2125701 DOI: 10.1159/000125563] [Citation(s) in RCA: 95] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The effect of corticotropin-releasing factor (CRF) on the hypothalamic gonadotropin-releasing hormone (GnRH) pulse generator, the central neuronal system governing pulsatile pituitary luteinizing hormone (LH) secretion, was studied electro-physiologically in 6 ovariectomized rhesus monkeys bearing bilateral arrays of recording electrodes implanted in the mediobasal hypothalamus. 'Volleys' of increased multiunit activity (MUA) were recorded for 6-10 h in animals placed in primate chairs. The circulating concentrations of LH and cortisol were determined by radioimmunoassay in blood samples taken every 10 min for 3-4 h prior to the administration of CRF (200 micrograms, i.v.) and for 3-6 h thereafter. CRF resulted in a significant decrease in the frequency of pulse generator activity in 4 of 6 animals, a significant decrease in the duration of MUA volleys and a rise in circulating cortisol levels in all 6 monkeys. Treatment with metyrapone (30 mg/kg, i.m.), an inhibitor of adrenal steroidogenesis that prevented the CRF-induced rise in serum cortisol levels, did not reverse the inhibitory effects of CRF on the frequency or duration of MUA volleys. The opiate antagonist naloxone (0.8 mg/kg, i.v., 10 min prior to CRF followed by 0.8 mg/kg/h infusion) blocked the effects of CRF on MUA volley frequency in 2 of 3 animals, but failed to block the effect of CRF on MUA volley duration, suggesting that endogenous opioids may mediate the action of CRF on pulse generator frequency but not on duration.
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Abstract
Thirty late-onset adrenal hyperplasia patients consulting for isolated hirsutism were randomly divided into two groups; group 1 (n = 16) was treated with hydrocortisone in order to suppress androgen adrenal secretion, and group 2 (n = 14) received cyproterone acetate (CPA) antiandrogen therapy to inhibit peripheral androgen activity. The clinical and hormonal effects of each type of treatment were evaluated. Before treatment, the clinical and hormonal profiles of the two patient groups did not differ significantly. Excellent clinical evolution in terms of the regression of hirsutism was observed in the CPA-treated patients (54% decrease in the clinical score in 1 yr), in contrast with the slight decrease in hirsutism (26%) after hydrocortisone treatment. In hydrocortisone-treated patients, plasma androgen decreased to normal levels: testosterone from 3.05 +/- 1.45 to 1.46 +/- 0.42 nmol/L and delta 4-androstenedione from 13.6 +/- 4.1 to 6.33 +/- 1.47 nmol/L. Conversely, in CPA-treated patients, only a slight decrease in testosterone from 2.98 +/- 1.98 to 2.29 +/- 0.64 nmol/L and in delta 4-androstenedione from 12.9 +/- 5.9 to 9.86 +/- 2.23 nmol/L was observed. This slight decrease in plasma androgens contrasts with the rapid clinical improvement after CPA. These results emphasize the importance of peripheral receptivity to androgens in the clinical expression of hyperandrogenism. Moreover, they indicate that peripheral antiandrogen therapy may be more appropriate in late-onset adrenal hyperplasia patients than conventional adrenal inhibition using cortisone therapy.
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The use of the antiprogestin RU486 (mifepristone) as an abortifacient in early pregnancy--clinical and pathological findings; predictive factors for efficacy. Contraception 1990; 41:221-43. [PMID: 2323217 DOI: 10.1016/0010-7824(90)90065-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
RU486, a potent antiprogesterone steroid was administered to 124 women requesting therapeutic abortion. All were less than 49 days from their last menstrual period. Ten of these subjects (Group I) received high doses of RU486 in a decremental dose regimen (400, 300, 200 and 100 mg/day) over 4 successive days and 14 received 50 mg/day for 7 days (Group II). A further 50 subjects (Group III) received 100 mg/day for seven days and the remaining 50 subjects (Group IV) received 450 mg in a single dose. In the first three groups, half the daily dose was given in the morning and the remainder in the evening. Blood was collected before, and on Days 4 and 7 and then once a week after commencing therapy until disappearance of circulating beta HCG. In addition to beta HCG, estradiol-17 beta (E2), progesterone (P), cortisol, and various metabolic and hematological parameters were measured. Plasma RU486 concentrations were also assayed in Group II, III and IV subjects on Day 7 of therapy and in some cases on Days 14 and 21. Ultrasonography was performed in all cases on Day 1 and on Day 14. All the patients bled within five days following RU486 administration, for 1 to 21 days. A complete abortion occurred in 60% in Group I, 50% in Group II, 86% in Group III, and 80% in Group IV. The difference between the last two groups and the first two was significant at p less than 0.01. The non-responders were submitted to a uterine vacuum aspiration. A stepwise discriminant analysis was performed and indicated that the best predictors of the outcome of therapy were beta HCG values and the gestational sac diameter. With these criteria, the prediction was accurate in 86.4% of the cases. The best results were obtained in the cases where the ultrasonic measurement of gestational sac was under 10 mm in diameter and the initial beta HCG values under 15,000 mIU/ml. Among the observed side effects were moderate pelvic cramps (20.9%), nausea (27%), fainting (4.8%); 61.3% of the women complained of fatigue. Heavy bleeding occurred in 15.3% of the women but only one of them required blood transfusion. In the patients with complete abortion, beta HCG values decreased to below 500 mIU/ml by Day 14 (but in 11 cases values fell below 2,000 mIU/ml only by Day 21). Plasma estradiol and progesterone also fell. Cortisol levels increased during therapy especially in subjects of Group I, but returned to basal values after termination of treatment.(ABSTRACT TRUNCATED AT 400 WORDS)
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Abstract
In a case-control study, 178 women diagnosed with fibroadenoma (FA) between 1976 and 1982 were compared with 178 age-matched controls in order to assess the risk factors for FA. Women who had a previous diagnosis of breast disease were excluded. The odds ratios (OR) of FA were calculated for different risk factors of breast disease from bivariate analysis as well as multivariate regression analysis. The highest ORs were found for a previous premenstrual mastalgia before first childbirth and a familial history (FH) of breast cancer (BC). Oral contraceptive (OC) use before a first full-term pregnancy (FFTP) does not modify this risk. Also current use of standard oral contraceptives (SOC) containing 50 micrograms of ethinyl estradiol per pill appeared to be protective and the correlation with FA was negative. These findings underline: (a) the predictive value of premenstrual mastalgia for the subsequent development of breast disease; (b) only current high-dose OC use is protective.
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Effects of a pure antiandrogen on gonadotropin secretion in normal women and in polycystic ovarian disease. Fertil Steril 1989; 52:42-50. [PMID: 2744186 DOI: 10.1016/s0015-0282(16)60786-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
To assess the role of androgens in gonadotropin regulation in women, we studied the effects of a pure nonsteroidal antiandrogen, Anandron (Cassenne, Paris, France). Nine normally cycling women (group 1) with acne and/or seborrhoea and nine patients with polycystic ovarian disease (PCOD) (group 2) received Anandron (100 mg twice a day) and a placebo. Both treatments were administered orally, in a cross-over randomized design, for two consecutive cycles (group 1) or months (group 2) separated by one cycle or 1 month. Luteinizing hormone (LH) pulse frequency and amplitude (cluster analysis), basal and gonadotropin-releasing hormone (GnRH)-stimulated plasma LH/follicle-stimulating hormone (FSH) levels were determined on day 5 of each treatment or placebo cycle. On days 5, 10, 20, and 24 of each cycle or month, plasma estradiol (E2), estrone (E1), testosterone (T), dihydrotestosterone (DHT), androstenedione (A), dehydroepiandrosterone sulfate (DHAS), sex hormone-binding globulin (SHBG) levels, and urinary androstanediol glucuronide (3 alpha-diol G) were measured. Plasma progesterone (P) levels were determined on days 20 and 24 of each cycle (group 1) and on days 5, 10, 20, and 24 (group 2). In both groups, seborrhea and acne decreased markedly within the first month and practically disappeared after 2 months of Anandron treatment. No adverse side effects were reported. None of the normal patients had any disturbance of menstrual cycles as assessed by basal body temperature shift, ultrasonography, and plasma P levels. In PCOD patients, cycles remained anovulatory.(ABSTRACT TRUNCATED AT 250 WORDS)
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Clobazam increases pulsatile luteinizing hormone secretion in normal men. ACTA ENDOCRINOLOGICA 1989; 120:485-9. [PMID: 2566248 DOI: 10.1530/acta.0.1200485] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
To investigate the effects of the 1,5-benzodiazepine, clobazam, on LH secretion in normal men, LH pulsatile secretion was defined after oral administration of 40 mg of clobazam or a placebo to 6 healthy male volunteers, according to a randomized cross-over design. LH pulse frequency increased significantly from a mean of 3.8 (range 3-5) pulses/8 h after placebo, to a mean of 5 (range 4-7) pulses/8 h (P less than 0.05), after clobazam. Mean LH concentrations and peak amplitudes did not change significantly. These results suggest that clobazam mediates its effects on LH secretion at the hypothalamic level by increasing the frequency of episodic GnRH release.
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[A program for biexponential decreases]. JOURNAL DE TOXICOLOGIE CLINIQUE ET EXPERIMENTALE 1987; 7:239-46. [PMID: 3694554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Biological effects of estradiol-17 beta in postmenopausal women: oral versus percutaneous administration. J Clin Endocrinol Metab 1986; 62:536-41. [PMID: 3080464 DOI: 10.1210/jcem-62-3-536] [Citation(s) in RCA: 182] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
To determine whether the route of administration or the type of estrogen used in estrogen replacement therapy (ERT) is more important in avoiding effects on hepatic function, 24 postmenopausal women were studied before and at the end of 2 months of oral or percutaneous administration of the same estrogen, estradiol-17 beta (E2). The treatments studied were oral micronized E2, 2 mg/day (9 women); oral E2 valerate, 2 mg/day (5 women), and percutaneous E2, 3 mg/day (10 women). Specific plasma biological and biochemical markers of estrogenic action were evaluated, namely, E2, estrone (E1), LH, FSH, sex steroid binding protein (SBP), renin substrate, antithrombin activity, and lipoproteins (high density lipoprotein cholesterol, low density lipoprotein cholesterol, very low density lipoprotein triglycerides). Both oral and percutaneous administration of E2 increased plasma E2 levels up to midfollicular values and decreased LH and FSH levels into the same range. Oral administration of E2 led to substantial increases in plasma E1, SBP, renin substrate, and VLDL levels, whereas AT decreased significantly. Percutaneous administration of E2 led to a physiological plasma E1/E2 ratio and did not induce any change in hepatic proteins. These data suggest that the route of administration of E2 determines the biochemical response to ERT in postmenopausal women. SBP is the most sensitive marker of the liver action of estrogen, and triglycerides also are simple and useful markers for this effect. Percutaneous E2 therapy is an effective method of ERT, and has no measurable effects on hepatic markers of estrogen action.
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Abstract
We studied the incidence of late-onset adrenal hyperplasia as a cause of hirsutism, its association with the major histocompatibility complex, and its clinical expression. Twenty-four of 400 women seen because of hirsutism were found to have late-onset adrenal hyperplasia, diagnosed on the basis of a high plasma level of 17-hydroxyprogesterone, and its marked increase after ACTH stimulation. The degree of hirsutism varied widely. Plasma antigen levels were high, especially the level of androstenedione, whereas 5 alpha-reductase activity, considered to be a good index of peripheral androgen utilization, showed frequent normal or low values. The 24 patients were genotyped, along with 84 family members, and plasma hormones were measured in the family members. We found a high correlation between late-onset adrenal hyperplasia and HLA antigens B14 and Aw33. Similar biologic profiles were observed in the patients and those of their siblings who were HLA identical (n = 9), confirming that late-onset adrenal hyperplasia is linked to the histocompatibility complex. These nine siblings had no hirsutism. We therefore conclude that the role of skin sensitivity to androgens is important in determining the clinical expression of this disorder.
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[Should one operate on bifocal tubal lesions in 1984? Apropos of 54 cases]. JOURNAL DE GYNECOLOGIE, OBSTETRIQUE ET BIOLOGIE DE LA REPRODUCTION 1984; 13:925-32. [PMID: 6543367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
Abstract
We have analysed 54 cases where the patients had two lesions in the tubes and were treated with microsurgery. The results of histological examinations show that chronic salpingitis in the major lesion. Infection was the aetiological cause in 76% of the cases. The results of microsurgical treatment are poor with a low rate of intra-uterine pregnancy: [19.4% (0.08-0.42) at 24-30 months for pregnancies that were continuing and for abortions, 11.7% (0.04-0.33) at 24-30 months using actuarial techniques for estimating pregnancies that were continuing]. There was a high risk of extra-uterine pregnancy [35% (0.18-0.58) at 24-30 months]. These results make us wonder whether microsurgery or in vitro fertilisation should be the treatment of preference in these cases where the tubes are affected in two areas.
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