Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
1.
Psychopharmacology (Berl) ; 179(3): 652-61, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15672272

RESUMO

RATIONALE: The potential to improve cognition in older women with estrogen or estrogen/progesterone therapy is currently a matter of intense debate. Only a few studies conducted so far have used electrophysiological indicators of cognitive information processing as outcome measures in randomised placebo controlled studies. OBJECTIVES: This study was undertaken to measure changes in event-related potentials (ERPs) after short (4 weeks) or prolonged (24 weeks) hormone treatment in older women. METHODS: A randomised, double-blind, placebo-controlled study in hysterectomized older women (aged 58-75 years) was performed (n = 51). The participants received orally estradiol (2 mg estradiol valerate), estradiol plus progesterone (100 mg micronized progesterone) or placebo for 24 weeks. Using four different paradigms, early and late ERPs were assessed at baseline and after 4 and 24 weeks of treatment. RESULTS: Strong hormone increases were observed in the two active treatment groups. However, no significant effects on any of the assessed ERPs were observed in either of the two treatment groups. Similar non-significant findings were obtained for reaction time and error rate. CONCLUSIONS: Estradiol or estradiol/progesterone treatment appears to have no strong effects on several ERP markers of information processing in older hysterectomized women. The current negative findings might suggest a reduced sensitivity of the aged brain to gonadal steroids.


Assuntos
Estrogênios/administração & dosagem , Potenciais Evocados/efeitos dos fármacos , Histerectomia , Progesterona/administração & dosagem , Idoso , Método Duplo-Cego , Quimioterapia Combinada , Potenciais Evocados/fisiologia , Feminino , Humanos , Pessoa de Meia-Idade , Pós-Menopausa/efeitos dos fármacos , Pós-Menopausa/fisiologia , Tempo de Reação/efeitos dos fármacos , Tempo de Reação/fisiologia
2.
Atherosclerosis ; 154(2): 387-98, 2001 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-11166771

RESUMO

The oxidation hypothesis of atherosclerosis implies that antioxidants are able to inhibit lipoprotein oxidation in the arterial wall and thereby retard atherogenesis. Since most of the animal studies performed have used very high doses of antioxidants, it is to date unknown whether antioxidants are effective antiatherosclerotic agents when given in pharmacological doses. Here we addressed this question using homozygous Watanabe heritable hyperlipidaemic (WHHL) rabbits as an animal model of atherosclerosis. The rabbits were divided into four groups, each consisting of ten animals. They received either a standard diet or a diet containing 4.3 mg ubiquinone-10, or 4.3 mg vitamin E or 15 mg probucol/kg body weight daily. After 12 months, the extent of aortic atherosclerosis was assessed as the intima thickness, media thickness and intima-to-media ratio in 14 cross sections equally distributed over the whole aorta. To evaluate the antioxidant effects of the diet, lipophilic and hydrophilic antioxidants, lipids, fatty acids and plasma oxidizability were measured after 0, 3 and 6 months of feeding. We found that supplementation with probucol significantly decreased aortic intima-to-media ratio compared to controls. The antiatherosclerotic action of probucol was accompanied by its beneficial action on plasma oxidizability and some plasma antioxidants. No decrease in aortic atherosclerosis was measured in ubiquinone-10- and vitamin E-supplemented rabbits, despite the fact that both antioxidants decreased plasma oxidizability and ubiquinone-10 increased the plasma levels of antioxidants. Taken together, these data suggest that pharmacological doses of probucol retard atherogenesis in WHHL rabbits by an antioxidant mechanism, while ubiquinone-10 and vitamin E at these dosages are ineffective in this highly hyperlipidaemic model. The measurement of some oxidation-related parameters in plasma, such as lipophilic antioxidants, polyunsaturated fatty acids and lipoprotein oxidizability, may be useful in assessing the risk of atherogenesis in humans.


Assuntos
Antioxidantes/administração & dosagem , Arteriosclerose/prevenção & controle , Hiperlipidemias/terapia , Oxirredução/efeitos dos fármacos , Administração Oral , Animais , Anticolesterolemiantes/administração & dosagem , Anticolesterolemiantes/farmacocinética , Antídotos/administração & dosagem , Antídotos/farmacocinética , Antioxidantes/farmacocinética , Aorta/efeitos dos fármacos , Aorta/patologia , Arteriosclerose/sangue , Arteriosclerose/etiologia , Arteriosclerose/patologia , Dieta , Relação Dose-Resposta a Droga , Ácidos Graxos Insaturados/sangue , Hiperlipidemias/sangue , Hiperlipidemias/complicações , Lipoproteínas/sangue , Probucol/administração & dosagem , Probucol/farmacocinética , Coelhos , Túnica Íntima/efeitos dos fármacos , Túnica Íntima/patologia , Ubiquinona/administração & dosagem , Ubiquinona/farmacocinética , Vitamina E/administração & dosagem , Vitamina E/farmacocinética
3.
Eur J Endocrinol ; 150(3): 243-55, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15012607

RESUMO

Evidence for a role of ovarian factors in the growth of metastatic breast cancer was first recognized over 100 years ago. Today, anti-estrogens are central to the treatment of breast cancer of all stages. We now understand that the action of estrogen is mediated by the estrogen receptors (ER) which are members of the nuclear receptor family of ligand-regulated transcription factors. In this article we review the molecular mechanisms through which ER activates transcription of target genes and through which available anti-estrogens mediate their therapeutic effects. We discuss possible mechanisms of failure of treatment with current anti-estrogens and how newer anti-estrogens under development attempt to address these problems. In addition an expanded view of the molecular mechanisms of estrogen action is leading to the development of novel selective ER modulators or SERMs.


Assuntos
Antineoplásicos Hormonais/farmacologia , Neoplasias da Mama/metabolismo , Antagonistas de Estrogênios/farmacologia , Receptores de Estrogênio/fisiologia , Animais , Antineoplásicos Hormonais/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Antagonistas de Estrogênios/uso terapêutico , Receptor alfa de Estrogênio , Receptor beta de Estrogênio , Feminino , Humanos , Camundongos , Cloridrato de Raloxifeno/farmacologia , Cloridrato de Raloxifeno/uso terapêutico , Ratos , Receptores de Estrogênio/química , Receptores de Estrogênio/genética , Receptores de Estrogênio/metabolismo , Tamoxifeno/farmacologia , Tamoxifeno/uso terapêutico
4.
J Steroid Biochem Mol Biol ; 88(2): 131-42, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15084345

RESUMO

The physiological effects of progesterone are mediated by the progesterone receptor (PR) isoforms PRA and PRB, transcribed from a single gene, under control of two distinct promoters. Both the isoforms display different, promoter- and cell line-specific transactivation properties. Upregulation of both isoforms in response to estradiol stimulation has been described, although the two promoters contain no classical estrogen response element (ERE). Therefore, we decided to investigate the regulation of PRB-expression through distinct estrogen receptor (ER)-isoforms: ERalpha and ERbeta We demonstrate, that in HeLa cells treated with E2, PRB promoter activity was enhanced (five-fold) by ERalpha, but not by ERbeta. ERbeta was also unable to stimulate activity of the PRB promoter in BT20 and Ishikawa cells, where ERalpha induced reporter activity by two-fold. Deletion of the AF1-but not AF2 domain from ERalpha resulted in loss of the transactivation potential in all cell lines tested. Furthermore, in BT20 cells deletion of the AF2 domain of ERalpha resulted in stronger transcriptional activation than that mediated through wild-type ERalpha. In SK-BR-3 cells both ERs repressed PRB promoter activity and this repression was enhanced by co-transfection of SRC1. However, strong estrogen-dependent stimulation was observed after deletion of AF2. We conclude that PRB expression is stimulated by ERalpha but not ERbeta in an unique, AF1-dependent but AF2-independent mechanism.


Assuntos
Estradiol/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Receptores de Estrogênio/fisiologia , Receptores de Progesterona/genética , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Receptor alfa de Estrogênio , Células HeLa , Humanos , Regiões Promotoras Genéticas , Ativação Transcricional
5.
Biofactors ; 6(2): 99-109, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9259991

RESUMO

Lipoprotein oxidation induced in vitro in whole plasma is expected to be a more relevant model of the lipoprotein oxidation in the arterial wall than the in vitro oxidation of single isolated lipoproteins, e.g., low density lipoprotein (LDL). However, it is unclear, whether the oxidizability of whole plasma may serve as an adequate measure of the oxidizability of plasma lipoproteins. We measured the oxidizability of whole plasma diluted 150-fold as an absorbance increase at 234 nm known to reflect the level of conjugated dienes in the samples. Plasma oxidation was induced by Cu(II), 2,2'-azobis-(2-amidinopropane) hydrochloride (AAPH), lipoxygenase or myeloperoxidase+H2O2. Oxidizability of human plasma measured in the presence of Cu(II) was found to correlate with the oxidizability of LDL measured in the common Cu(II)-based LDL oxidation assay. The plasma oxidizability also correlated positively with plasma oxidizable fatty acid and negatively with plasma antioxidant content. Supplementation of human plasma with different antioxidants (albumin, urate, ascorbate, bilirubin, alpha-tocopherol and ubiquinol-10) in vitro decreased its oxidizability. Supplementation of Watanabe heritable hyperlipidaemic rabbits with different antioxidants (vitamin E, ubiquinone-10, probucol, carvedilol) in vivo lowered the oxidizability of rabbit plasma in comparison with rabbits fed standard diet. When plasma from hyperlipidaemic patients with or without coronary heart disease and from age-matched healthy controls was studied, the plasma oxidizability was found to be highest in the patients with coronary heart disease and lowest in the controls. Taken together, these data indicate that the plasma oxidation assay (i) provides information similar to that obtained using the common LDL oxidation assay, (ii) upgrades the latter, taking into account the effect of hydrophilic antioxidants on lipoprotein oxidation and characterizing the oxidizability of all plasma lipoproteins, and (iii) offers important practical advantages, such as fast and simple sample processing, low amount of plasma required and avoidance of artefactual oxidation during lipoprotein isolation. We propose the measurement of plasma oxidizability at 234 nm as an adequate practical index of the oxidizability of plasma lipoproteins.


Assuntos
Antioxidantes/metabolismo , Hiperlipidemias/sangue , Lipoproteínas LDL/sangue , Lipoproteínas/sangue , Oxidantes , Amidinas , Animais , Antioxidantes/análise , Carotenoides/sangue , Cobre , Ácidos Graxos não Esterificados/sangue , Humanos , Peróxido de Hidrogênio , Hiperlipidemias/genética , Lipoxigenase , Oxirredução , Peroxidase , Coelhos , Análise de Regressão , Ubiquinona/análogos & derivados , Ubiquinona/sangue , Vitamina E/sangue , beta Caroteno/sangue
6.
Gynecol Oncol ; 89(2): 334-7, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12714000

RESUMO

BACKGROUND: Herpes gestationis (HG) is a rare, recurrent, pruritic, vesicobullous dermatosis occurring predominantly in pregnancy and seldom in early puerperium. Reports of the association of HG with choriocarcinoma are extremely rare and this case highlights such a possible link. CASE: This case focuses on the late postpartal manifestation of HG being associated with metastatic high-risk choriocarcinoma. Direct immunofluorescence was used to verify the diagnosis of HG. Symptomatic therapy with corticosteroids and antihistamines alleviated the pruritic symptoms associated with HG, but only the recurrent course of chemotherapy for the choriocarcinoma resulted in complete disappearance of all signs and symptoms of the HG. CONCLUSION: The time course of this case highlights once again the possible association of HG as a paraneoplastic syndrome of choriocarcinoma.


Assuntos
Coriocarcinoma/complicações , Síndromes Paraneoplásicas/complicações , Penfigoide Gestacional/complicações , Neoplasias Uterinas/complicações , Adulto , Feminino , Humanos , Gravidez
7.
Horm Metab Res ; 33(8): 451-7, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11544557

RESUMO

Proliferation of breast and endometrial cells is under the control of ovarian steroid hormones (SHs) such as oestrogen and progesterone. They mediate diverse physiological functions via interaction with nuclear-localised steroid hormone receptors (HRs). The SH receptor complex modifies the expression of SH-regulated genes by binding to conserved binding sites in their promoter region or through cross-talk with other transcription factors. In non-malignant tissues, HRs are in balance with other factors regulating proliferation, differentiation and apoptosis. While dysfunction of the regulatory mechanisms is a part of malignant transformation, functional SH receptors can promote growth of SH-responsive tumours. Therefore, anti-hormones that block the interaction of steroid hormones with the SH receptor are useful tools for the treatment of SH-responsive carcinomas. However, a portion of ER-positive breast cancers and most endometrial cancers do not respond to anti-oestrogens and continued treatment results in hormone resistance, mostly without loss of the ER. This review focuses on the mechanisms of action of hormones and anti-hormones in breast and endometrial carcinomas.


Assuntos
Neoplasias da Mama/metabolismo , Neoplasias do Endométrio/metabolismo , Moduladores de Receptor Estrogênico/metabolismo , Estrogênios/metabolismo , Receptores de Estrogênio/metabolismo , Animais , Sítios de Ligação/fisiologia , Neoplasias da Mama/tratamento farmacológico , Progressão da Doença , Neoplasias do Endométrio/tratamento farmacológico , Moduladores de Receptor Estrogênico/uso terapêutico , Feminino , Expressão Gênica/fisiologia , Antagonistas de Hormônios/metabolismo , Hormônios/metabolismo , Humanos , Receptor Cross-Talk/fisiologia , Receptores de Esteroides/metabolismo , Esteroides/metabolismo , Fatores de Transcrição/metabolismo
8.
Oncology ; 60(3): 199-206, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11340370

RESUMO

PURPOSE: Breast cancer (BC) is the most frequent female carcinoma and the major cause of death in women aged 35--50 years. The total number of patients surviving BC and especially the morbidity rate of patients below the age of 55 years has increased significantly in the last several years. As a consequence, the number of BC patients suffering from the long-term effects of estrogen deficiency due to adjuvant treatment is increasing. At present, hormone replacement therapy (HRT) following BC treatment is applied individually and mainly depends on the severity of postmenopausal symptoms (PMS) experienced by these patients. PATIENTS AND METHODS: In a retrospective study (total n = 185 BC patients, 64 with and 121 without HRT), the effect of HRT during or after adjuvant therapy [chemotherapy and/ or (anti-) hormonotherapy] has been investigated. The surveillance period was up to 60 months. Evaluated were HRT effects on (1) PMS measured by a comprehensive life quality questionnaire, (2) bone mineral density (BMD) measured by osteodensitometry and (3) morbidity as well as mortality rates. RESULTS: Both groups did not differ with regard to tumor stage, lymph node involvement, metastasis, grading, and steroid hormone receptor status. A reduction in PMS was significant in women taking HRT (p < 0.001), especially in the subgroup of women < or =50 years (p < 0.0001). For both age groups, the median reduction in BMD (z-score) was less in women receiving HRT (< or =50 years: without HRT -1.99 vs. with HRT -0.95, p < 0.05; >50 years: without HRT -2.29 vs. with HRT -1.19, p < 0.01). There were no statistically significant differences regarding morbidity and mortality (p = 0.29). CONCLUSION: In this study of BC patients, the use of HRT shows positive effects on PMS and BMD. There was no significant influence on morbidity or mortality. However, a reevaluation of HRT in the routine management of BC patients should await the results of prospective randomized trials.


Assuntos
Densidade Óssea/efeitos dos fármacos , Neoplasias da Mama/terapia , Terapia de Reposição de Estrogênios , Pós-Menopausa , Adulto , Idoso , Neoplasias da Mama/etiologia , Terapia de Reposição de Estrogênios/efeitos adversos , Feminino , Humanos , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Estudos Retrospectivos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA