RESUMEN
A 33-year-old woman presented with an ectopic pregnancy without any complaints. Laparoscopy was performed since a tubal pregnancy was expected. However, both fallopian tubes appeared normal and it was not possible to differentiate accurately between a pregnancy in a non-communicating horn and a pregnancy in a bicornuate uterus. We therefore performed MRI which showed a thin myometrium around the pregnancy. In order to differentiate between a communicating and a non-communicating uterine horn the authors performed a hysteroscopy. Since there was only one cervical os, and an entrance to the second uterine cavity was not seen along the cervical canal, it was concluded that this pregnancy was situated in a non-communicating rudimentary horn. The non-communicating uterine horn, with the pregnancy in situ, was completely removed. Since a pregnancy in a bicornuate uterus is viable in contrast to a pregnancy in a non-communicating horn, accurate diagnosis is important.
Asunto(s)
Histeroscopía , Complicaciones del Embarazo/diagnóstico , Útero/anomalías , Adulto , Femenino , Humanos , EmbarazoRESUMEN
BACKGROUND AND OBJECTIVE: Despite published guidelines, a proportion of red blood cell (RBC) transfusions seem unnecessary. To evaluate the indications for and the appropriateness of RBC transfusions in the postpartum patient, we performed a retrospective audit over a 1-year period in two Dutch hospitals. STUDY DESIGN AND METHODS: Observational study of transfused obstetric patients, admitted in 2006 to the Departments of Obstetrics of a university and a general hospital, was carried out. Relevant clinical and laboratory data were recorded. The appropriateness of RBC transfusions was assessed using the national and age-based transfusion guidelines for the general population; for the studied group the transfusion threshold haemoglobin (Hb) value was 6.4 g/dl for non-massive and 8.1 g/dl for massive blood loss. From these we derived target Hb levels. RESULTS: Ninety patients received one or more RBC units within 48 h of delivery. Mean pretransfusion Hb level was 6.9 [SD 1.2] g/dl. Median number of transfusions was 2. Mean Hb level at discharge was 9.7 [SD 1.1] g/dl. Taking threshold Hb and the derived target Hb level into account, 68% (n = 61) of the patients may have received one or more RBC units inappropriately. Of 311 RBC units transfused, 143 units (46%) were possibly inappropriate, partly due to over-transfusion. CONCLUSION: A significant proportion of postpartum RBC transfusions are possibly inappropriate, partly due to over-transfusion. If current guidelines would be more specific, in particular, with respect to the target Hb levels, the total amount of RBC transfusions may be considerably decreased.
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Transfusión de Eritrocitos/estadística & datos numéricos , Hemorragia Posparto/terapia , Adulto , Femenino , Hemoglobinas/análisis , Humanos , Periodo Posparto , Guías de Práctica Clínica como Asunto , Estudios Retrospectivos , Procedimientos InnecesariosRESUMEN
OBJECTIVE: We investigated the serum phytosterol responses of heterozygous relatives of sitosterolemia patients to diets enriched in phytosterols or stanols. DESIGN: Randomized double-blind crossover design. SETTING: Muenster, Germany. SUBJECTS: Eight heterozygous and 13 control subjects were recruited. One heterozygote and three controls dropped out. INTERVENTIONS: Seven heterozygotes and 10 controls received daily portions of margarine containing 2 g of plant sterols, 2 g of stanols or a control margarine for 6 weeks each in a randomized order. These phases were intercepted by wash-out periods of 6 weeks each. RESULTS: Compared to the control period, serum phytosterol concentrations increased overall by more than 20% when subjects consumed the plant sterol margarine (F((1,15))=8.719, P=0.01), with no significant difference between heterozygotes (mean +14.5 (s.d. 17.2) micromol/l, +23.0%) and controls (+4.9 (9.9) micromol/l, +20.5%; F((1,15))=2.168, P=0.162), but decreased when subjects consumed the stanol-enriched margarine (F((1,15))=12.124, P=0.003), again to a similar extent in heterozygotes (-34.2 (41.2) micromol/l, -54.2%) and controls (-12.2 (9.2) micromol/l, -50.6%; F((1,15))=2.729, P=0.119). The lowest total serum concentrations of cholesterol and phytosterols were seen after the diet enriched in stanols. Serum stanol concentrations increased on this diet, but on a very low level and never exceeded 0.05% of serum cholesterol levels in any subject. CONCLUSIONS: Serum phytosterol concentrations increased only moderately in heterozygotes consuming a diet enriched in phytosterols, indicating that they retained considerable capacity to excrete phytosterols even at higher intakes.
Asunto(s)
Anticolesterolemiantes/administración & dosificación , Anticolesterolemiantes/sangre , Margarina , Fitosteroles , Sitoesteroles/sangre , Adulto , Colesterol/sangre , Estudios Cruzados , Método Doble Ciego , Ésteres , Femenino , Alemania , Humanos , Masculino , Fitosteroles/administración & dosificación , Fitosteroles/sangre , Sitoesteroles/administración & dosificación , Esteroles/administración & dosificación , Esteroles/sangreRESUMEN
An 82-year-old postmenopausal woman presented with severe clinical hyperandrogenism related to testosterone overproduction, possibly as a result of a mucinous cystadenoma. The cystadenoma was successfully removed in toto. The patient was discharged in good health. Plasma testosterone levels normalised 6 weeks after surgery. Ovarian mucinous cystadenomas are a rare cause ofhyperandrogenism.
Asunto(s)
Cistoadenoma/complicaciones , Neoplasias Ováricas/complicaciones , Testosterona/sangre , Virilismo/etiología , Anciano de 80 o más Años , Cistoadenoma/metabolismo , Cistoadenoma/cirugía , Femenino , Humanos , Neoplasias Ováricas/metabolismo , Neoplasias Ováricas/cirugía , Resultado del TratamientoRESUMEN
Allogeneic stem cell transplantation (allo-SCT) is considered the most potent postremission therapy for acute myeloid leukemia (AML). Its superior antileukemic activity is largely ascribed to the powerful graft-versus-leukemia (GvL) effects exerted by donor lymphocytes. However, due to considerable treatment-related lethality the gains in relapse prevention do not necessarily translate into survival advantages in the overall patient population. Therefore, allo-SCT for adult patients with AML in first complete remission (CR1) is currently recommended only for younger and medically fit patients who are at intermediate to high risk of relapse and have an HLA-identical sibling donor. Stem cell allografting from alternative donors in CR1 is considered an option for high risk patients as defined by cytogenetic abnormalities or incomplete response after one course of induction chemotherapy and should usually be performed in the context of a clinical protocol.
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Trasplante de Médula Ósea , Leucemia Mieloide/cirugía , Trasplante de Células Madre , Trasplante Homólogo , Enfermedad Aguda , Supervivencia sin Enfermedad , Alemania , Humanos , Leucemia Mieloide/mortalidad , Factores de Tiempo , Acondicionamiento Pretrasplante/métodosRESUMEN
This review examines the evidence for the effects of tibolone on bone. Tibolone is a synthetic steroid with a mixed (estrogenic-progestogenic-androgenic) hormonal profile. Data suggest a complex receptor-mediated as well as metabolic regulation of the activity of tibolone at target tissue level. It has been shown that tibolone can prevent axial and appendicular bone loss induced by ovariectomy and/or a low calcium diet in young and mature rats. In addition, tibolone increases trabecular and cortical bone mineral density in rats with established osteopenia. In the rat, treatment with tibolone results in an increased strength of the femoral neck and of the vertebral body, similar to that found with estrogens. The protective effect on bone can be blocked by antiestrogens, indicating that the effect is estrogen receptor-mediated. Clinical trials have shown that loss of bone in the spine and proximal hip can be prevented with tibolone 2.5 mg/day in early- and late-postmenopausal women. In addition, a dose of 1.25 mg/day seems also to be effective, especially in late-postmenopausal women. In women with established osteoporosis, bone density of the axial and appendicular skeleton increases with tibolone. In comparative studies, tibolone 2.5 mg/day seems to be as effective as conventional hormone replacement therapy regimens. There are no direct comparative studies between tibolone and bisphosphonates or raloxifene. Furthermore, to establish the efficacy of tibolone for prevention of osteoporotic fractures, studies of the magnitude of reduction in fracture risk remain to be conducted. Finally, tibolone seems to be effective in preserving bone density in patients treated with gonadotropin-releasing hormone agonist.
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Anabolizantes/uso terapéutico , Terapia de Reemplazo de Hormonas , Norpregnenos/uso terapéutico , Osteoporosis Posmenopáusica/prevención & control , Anabolizantes/farmacología , Animales , Densidad Ósea/efectos de los fármacos , Ensayos Clínicos como Asunto , Femenino , Humanos , Norpregnenos/farmacología , RatasRESUMEN
Glucocorticoids (GCs) exacerbate various insults to the hippocampus but the exact molecular mechanisms of this GC activity is not known. GCs can suppress the activity of the redox-sensitive nuclear factor NF-kappaB, which potentially serves neuroprotective functions. Employing electrophoretic mobility shift assays and transfection assays using a NF-kappaB-dependent reporter plasmid, we demonstrate that the increased oxidative stress sensitivity of clonal mouse hippocampal HT22 cells caused by GCs is associated with the suppression of NF-kappaB. GCs increased the expression of IkappaBalpha, the physiological inhibitor of NF-kappaB. Downregulation of NF-kappaB activity after overexpression of a dominant-negative mutant form of IkappaBalpha results in an increased sensitivity to oxidative stress. We conclude that the suppression of the basal NF-kappaB activity contributes to the enhanced vulnerability of neuronal cells to oxidative stress caused by GCs.
Asunto(s)
Células Cultivadas/efectos de los fármacos , Dexametasona/toxicidad , Hipocampo/efectos de los fármacos , FN-kappa B/efectos de los fármacos , Neuronas/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Animales , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/genética , Células Cultivadas/citología , Células Cultivadas/metabolismo , Proteínas de Unión al ADN/efectos de los fármacos , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Regulación hacia Abajo/efectos de los fármacos , Regulación hacia Abajo/fisiología , Hipocampo/citología , Hipocampo/metabolismo , Ratones , FN-kappa B/metabolismo , Neuronas/citología , Neuronas/metabolismo , Estrés Oxidativo/fisiología , Regiones Promotoras Genéticas/efectos de los fármacos , Regiones Promotoras Genéticas/fisiología , Receptores de Glucocorticoides/efectos de los fármacos , Receptores de Glucocorticoides/metabolismo , Transcripción Genética/efectos de los fármacos , Transcripción Genética/fisiología , TransfecciónRESUMEN
OBJECTIVE: To investigate a potential correlation between vaginal bleeding and oestradiol (E2) levels/endometrial morphology in early postmenopausal women using tibolone (Livial(R)). METHODS: A 2-year randomised placebo-controlled study of 94 healthy women, 1-3 years after spontaneous menopause, receiving either placebo (n=23), 1.25 mg/day (n=36) or 2.5 mg/day (n=35) tibolone. Episodes of vaginal bleeding throughout the 2-year study period were recorded. Age, age of menopause, months since menopause and body mass index were recorded. Serum E2 levels were assessed at baseline and at 3-month intervals throughout the study period. In case of vaginal bleeding, endometrium morphology was assessed by Vabra Curettage. RESULTS: Fifty-one percent (n=18, P<0.05) of women in the 2.5 mg/day tibolone group and 44% (n=16, P=0.07) in the 1.25 mg/day tibolone group presented with at least one period of vaginal bleeding, compared with 22% (n=5) in the placebo group. The women who bled in the placebo group were younger (P<0.01), had menopause at an earlier age (P<0.05), had a shorter duration since menopause (P<0.05) and had a higher median E2 serum level prior to bleeding (P<0.05). In contrast, in both tibolone groups, no determinants could be found for the vaginal bleeding. Ninety percent of the first bleedings occurred within 9 months after starting the treatment. At Vabra endometrium sampling, there was no evidence of endometrial stimulation. CONCLUSIONS: In the present study, early postmenopausal women using 1.25 or 2.5 mg/day tibolone are 2-2.5 times more likely to present with vaginal bleeding compared with placebo (P<0.05) without evidence of higher serum E2 levels or endometrial stimulation.
Asunto(s)
Endometrio/efectos de los fármacos , Estradiol/sangre , Norpregnenos/farmacología , Posmenopausia , Hemorragia Uterina/inducido químicamente , Densidad Ósea/efectos de los fármacos , Endometrio/patología , Femenino , Humanos , Persona de Mediana Edad , Norpregnenos/efectos adversosRESUMEN
The neuropeptide CRH is the central regulator of the hypothalamic-pituitary-adrenal (HPA) stress response system and is implicated in various stress-related conditions. In the neurodegenerative disorder Alzheimer's disease (AD), levels of CRH are decreased. AD pathology is characterized by the deposition of the nonsoluble amyloid beta protein (A beta), oxidative stress, and neuronal cell death. Employing primary neurons and clonal cells, we demonstrate that CRH has a neuroprotective activity in CRH-receptor type 1 (CRH-R1)-expressing neurons against oxidative cell death. The protective effect of CRH was blocked by selective and nonselective CRH-R1 antagonists and by protein kinase A inhibitors. Overexpression of CRH-R1 in clonal hippocampal cells lacking endogenous CRH-receptors established neuroprotection by CRH. The activation of CRH-R1 and neuroprotection are accompanied by an increased release of non-amyloidogenic soluble A beta precursor protein. At the molecular level CRH caused the suppression of the DNA-binding activity and transcriptional activity of the transcription factor NF-kappaB. Suppression of NF-kappaB by overexpression of a super-repressor mutant form of IkappaB-alpha, a specific inhibitor of NF-kappaB, led to protection of the cells against oxidative stress. These data demonstrate a novel cytoprotective effect of CRH that is mediated by CRH-R1 and downstream by suppression of NF-kappaB and indicate CRH as an endogenous protective neuropeptide against oxidative cell death in addition to its function in the HPA-system. Moreover, the protective function of CRH proposes a molecular link between oxidative stress-related degenerative events and the CRH-R1 system.
Asunto(s)
Precursor de Proteína beta-Amiloide/metabolismo , Hormona Liberadora de Corticotropina/metabolismo , FN-kappa B/antagonistas & inhibidores , Neuronas/metabolismo , Estrés Oxidativo , Animales , Apoptosis/efectos de los fármacos , Butionina Sulfoximina/farmacología , Células Cultivadas , Cerebelo/citología , Cerebelo/efectos de los fármacos , Cromatina/efectos de los fármacos , Hormona Liberadora de Corticotropina/genética , Proteínas de Unión al ADN/antagonistas & inhibidores , Inhibidores Enzimáticos/farmacología , Hipocampo/efectos de los fármacos , Humanos , Peróxido de Hidrógeno/farmacología , Etiquetado Corte-Fin in Situ , Ratones , FN-kappa B/metabolismo , Neuronas/citología , Neuronas/efectos de los fármacos , Oxidantes/farmacología , Hipófisis/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Receptores de Hormona Liberadora de Corticotropina/antagonistas & inhibidores , Receptores de Hormona Liberadora de Corticotropina/metabolismo , Transcripción GenéticaRESUMEN
OBJECTIVE: Assessment of loss of bone density (BD) 1 year after a 2-year period of hormone replacement therapy (HRT) with two doses of Tibolone as compared to placebo in early post-menopausal women. METHODS: Sixty-four out of 84 women (1-3 years following spontaneous menopause) who completed a 2-year randomised, placebo controlled study to evaluate effects of Tibolone participated in this follow-up study. Quantitative computed tomography was used to exclusively measure trabecular BD, microdensitometry of the mid-phalangeal shaft was used for estimation of cortical BD and biochemical markers of bone metabolism were assessed, 1 year after discontinuation of Tibolone. The study group received either placebo (n = 16), 1.25 mg/day Tibolone (n = 25) or 2.5 mg/day Tibolone (n = 23). RESULTS: Observations revealed a significantly greater decrease in trabecular BD during the post-trial year in both treatment groups compared to the placebo group (for 1.25 mg/day Tibolone, -6.0%, 95% CI -8.4 to -3.5; for 2.5 mg/day Tibolone, -10.0%, 95% CI: -12.9 to -6.9). In contrast, there was no significant difference in loss of phalangeal BD in both treatment groups compared to placebo. Biochemical markers (serum alkaline phosphatase, urinary excretion of hydroxyproline and calcium) do not suggest an increased bone turnover comparing Tibolone groups to placebo, 1 year after cessation of Tibolone. CONCLUSION: The present study suggests an increased loss of trabecular but not cortical BD as compared to the placebo group in the first year after cessation of HRT with Tibolone in early post-menopausal women.
Asunto(s)
Anabolizantes/farmacología , Densidad Ósea/efectos de los fármacos , Resorción Ósea/metabolismo , Terapia de Reemplazo de Estrógeno , Norpregnenos/farmacología , Método Doble Ciego , Femenino , Estudios de Seguimiento , Humanos , Persona de Mediana EdadRESUMEN
gamma-Aminobutyric acid type A (GABAA) receptor subtypes containing the alpha6-subunit are generally thought to be insensitive to the action of benzodiazepine agonists. We describe the specific binding of the benzodiazepine agonist flunitrazepam to alpha6beta2gamma2-containing GABAA receptors, which has not been observed before and differs from previous reports. With the whole-cell voltage-clamp technique, we observed a functional discrimination between alpha1beta2gamma2- and alpha6beta2gamma2-receptors. Different benzodiazepines had different effects on GABA-evoked chloride currents. The agonist flunitrazepam had an inverse agonistic effect, whereas the antagonist flumazenil increased GABA-induced chloride currents. The action of flunitrazepam on the channel activity of alpha6beta2gamma2-receptors was opposite to its action on alpha1beta2gamma2-receptors. We conclude that flunitrazepam can act as either an agonist or an inverse agonist, depending on the GABAA receptor configuration.
Asunto(s)
Canales de Cloruro/fisiología , Flunitrazepam/farmacología , Agonistas del GABA/farmacología , Receptores de GABA-A/fisiología , Ácido gamma-Aminobutírico/farmacología , Marcadores de Afinidad , Azidas/farmacología , Benzodiazepinas/farmacología , Sitios de Unión , Unión Competitiva , Línea Celular , Canales de Cloruro/efectos de los fármacos , Flunitrazepam/metabolismo , Agonistas de Receptores de GABA-A , Humanos , Riñón , Cinética , Sustancias Macromoleculares , Potenciales de la Membrana/efectos de los fármacos , Receptores de GABA-A/química , Proteínas Recombinantes/agonistas , Proteínas Recombinantes/metabolismo , TransfecciónRESUMEN
The present randomized, double-blind, placebo-controlled, 2-year study is the first to evaluate the effect of 1.25 and 2.5 mg tibolone daily oral administration on trabecular and cortical bone loss in early postmenopausal women. Ninety-four healthy, normal weight, nonsmoking women participated 1-3 years following spontaneous menopause. Twenty-three subjects were randomized to the placebo group, 36 to the 1.25 mg/day tibolone group, and 35 to the 2.5 mg/day tibolone group. Bone density was assessed at 6 month intervals. Spinal trabecular bone density (BD) was measured with quantitative computed tomography. Phalangeal cortical BD was measured by radiographic absorptiometry. The 2-year change vs. baseline in the placebo group for trabecular BD was -6.4% (95% confidence interval -8.1 to -4.7). Cortical BD did not change significantly. At 24 months both tibolone groups showed a statistically significantly higher trabecular [9.4% (6.6-12.2) for the 1.25 mg group and 14.7% (11.8-17.5%) for the 2.5 mg group] and phalangeal BD [4.4% (1.5-7.4) for the 1.25 mg group and 6.8% (3.8-9.8) for the 2.5 mg group] as compared to the placebo group. After 2 years of tibolone in both regimes, trabecular and phalangeal BD was significantly higher as compared to pretreatment values. At 24 months the 2.5 mg group showed a significantly higher trabecular (p < 0.001) but not phalangeal (p = 0.064) BD compared to the 1.25 mg group. Tibolone prevents early postmenopausal bone loss by inducing an increase in trabecular and phalangeal BD.
Asunto(s)
Anabolizantes/uso terapéutico , Densidad Ósea/efectos de los fármacos , Norpregnenos/uso terapéutico , Osteoporosis Posmenopáusica/prevención & control , Absorciometría de Fotón , Anabolizantes/administración & dosificación , Anabolizantes/farmacología , Análisis de Varianza , Biomarcadores/sangre , Femenino , Humanos , Estudios Longitudinales , Persona de Mediana Edad , Norpregnenos/administración & dosificación , Norpregnenos/farmacología , Osteoporosis Posmenopáusica/tratamiento farmacológicoRESUMEN
Neuroactive steroids rapidly alter neuronal excitability through their action via the cell surface. The 3 alpha-hydroxy ring A-reduced pregnane steroids enhance gamma-aminobutyric acid (GABA)-mediated Cl- currents while pregnenolone sulfate and dehydroepiandrosterone sulfate may exert functional antagonistic properties. Based on our previous findings that the 3 alpha-hydroxy ring A-reduced pregnane steroids allotetrahydroprogesterone and allotetrahydrodeoxycorticosterone may regulate gene expression via the progesterone receptor after intracellular oxidation, we have characterized the effects of a series of natural and synthetic neuroactive steroids at the genomic level using a cotransfection system with various steroid receptor expression vectors and a reporter gene in a human neuroblastoma cell line. Pregnanolone and pregnenolone were able to activate both the chicken and the human progesterone receptor while the synthetic 3 alpha-hydroxylated derivative alphaxalone and dehydroepiandrosterone were active via the chicken progesterone receptor but devoid of transcriptional activity via the human progesterone receptor. Moreover, the antiglucocorticoid activity of dehydroepiandrosterone reported at the systemic level could not be reconstituted in the cellular cotransfection system. None of the neuroactive steroids bound directly to steroid receptors. Thus, their genomic activity appears to be mediated via intracellular metabolization. This study provides evidence for differential genomic effects of neuroactive steroids in a structure-specific and species-specific way that may have impact on the development of these steroids for therapeutic application.
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Neuronas/efectos de los fármacos , Receptores de Progesterona/efectos de los fármacos , Esteroides/farmacología , Animales , Pollos , Deshidroepiandrosterona/farmacología , Humanos , Receptores de Progesterona/análisis , Receptores de Progesterona/metabolismo , Esteroides/metabolismo , Relación Estructura-Actividad , Transcripción Genética/efectos de los fármacos , Células Tumorales CultivadasRESUMEN
Skin and bone both contain primarily type I collagen in connective tissue matrices and are assumed to be related due to this common organic constituent. The purpose of this study was to investigate whether skin thickness measurements by ultrasound (US) could be used for screening for low bone mass. In 94 healthy, white, non-smoking women, 1-3 years postmenopause, the thickness of the skin of the left upper arm and forearm was measured by ultrasound (US). These measurements were compared with values of bone mineral density (BMD) as measured by quantitative computed tomography (QCT) of the lumbar spine and quantitative video micro-densitometry (QMD) of the hand. The correlation found between US skin thickness measurements and BMD results was of low magnitude and not significant. It is concluded that US measurements of skin thickness cannot be used to screen early postmenopausal women for low bone mass.
Asunto(s)
Densidad Ósea , Posmenopausia , Piel/diagnóstico por imagen , Huesos/diagnóstico por imagen , Estudios Transversales , Femenino , Humanos , Persona de Mediana Edad , Tomografía Computarizada por Rayos X , UltrasonografíaRESUMEN
We characterized the pharmacological profiles of the human mineralocorticoid and glucocorticoid receptor for 11 natural and synthetic steroids regarding binding pharmacology, intracellular localization of hormone-receptor complexes, and agonistic or antagonistic properties at the gene expression level. The sex steroid progesterone bound with an affinity (ki < 0.01 nM) even higher than that of aldosterone to the human mineralocorticoid receptor and effectively antagonized the effect of aldosterone via the human mineralocorticoid receptor in functional co-transfection assays. This indicates that progesterone has potent antimineralocorticoid properties, while its antiglucocorticoid effects were less pronounced. The partial agonistic activities of antihormones in this assay suggest a direct interaction of antihormone-receptor complexes with the response elements on the DNA. These results are supported by immunofluorescence studies, in which both unliganded human mineralocorticoid and glucocorticoid receptors were distributed throughout the cytoplasm and nucleus, whereas agonist- as well as antagonist-receptor complexes showed an exclusively nuclear localization. These results contribute to the understanding of antihormone pharmacology and increase our understanding of the role of human mineralocorticoid and glucocorticoid receptors in physiological processes during different endocrine states.
Asunto(s)
Receptores de Glucocorticoides/efectos de los fármacos , Receptores de Mineralocorticoides/efectos de los fármacos , Aldosterona/metabolismo , Animales , Unión Competitiva/efectos de los fármacos , Citosol/enzimología , Técnica del Anticuerpo Fluorescente , Genes Reporteros , Humanos , Ligandos , Luciferasas/biosíntesis , Virus del Tumor Mamario del Ratón/enzimología , Virus del Tumor Mamario del Ratón/genética , Ratones , Neuroblastoma/metabolismo , Plásmidos , Progesterona/farmacología , Esteroides/metabolismo , Esteroides/farmacología , Células Tumorales CultivadasRESUMEN
OBJECTIVES: Is there an influence of oral contraceptive use, parity and lactation on early postmenopausal bone mass? Is assessment of reproductive history, body weight in combination with biochemical markers of bone metabolism suitable to predict lumbar bone mass soon after menopause? STUDY DESIGN: A cross-sectional study in 94 healthy, normal weight, non-smoking women, 1-3 years after spontaneous menopause. Bone mineral density (BMD) of the lumbar spine was measured with single energy quantitative computed tomography. RESULTS: Multiple regression analysis showed that only total duration of lactation and alkaline phosphatase (AP) levels are independently related to trabecular BMD (P = 0.001 and P = 0.002 respectively). AP was also associated with cortical BMD (P = 0.003). Assessment of reproductive history, body mass index and biochemical markers of bone metabolism could only account for 17% of the variation of trabecular BMD observed in the study population. CONCLUSION: This study suggests that total duration of lactation rather than parity is associated with trabecular BMD of the spine. Clinical assessment of risk factors unsuccessfully predicts lumbar BMD in healthy, early postmenopausal women.