RESUMO
Breast constitutional density may be altered and increased (acquired density) by hormonal interventions such as hormone replacement therapy (HRT). The effects of endogenous (steroids, prolactin, insulin-like factors...) and exogenous (HRT, levonorgestrel IUD, tibolone, tamoxifen, SERMs) hormones will be reviewed. Continuous combined estrogen-progestin preparations are most likely to cause an increase in density. Estrogen alone and tibolone are less likely to cause an increase in density. The sensitivity and specificity of mammography are decreased, with increased risk of interval carcinoma and rate of short interval follow-up from false positive results. The issue with regards to interruption of the hormonal therapy prior to mammography, and the duration of the interruption, are discussed.
Assuntos
Neoplasias da Mama/induzido quimicamente , Mama , Terapia de Reposição de Estrogênios/efeitos adversos , Hormônios/fisiologia , Mamografia , Adulto , Idoso , Biópsia , Mama/efeitos dos fármacos , Mama/patologia , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Anticoncepcionais Femininos/farmacologia , Diagnóstico Diferencial , Feminino , Hormônios Esteroides Gonadais/fisiologia , Humanos , Dispositivos Intrauterinos , Levanogestrel/farmacologia , Menopausa , Ciclo Menstrual , Pessoa de Meia-Idade , Norpregnenos/farmacologia , Estudos Prospectivos , Ensaios Clínicos Controlados Aleatórios como Assunto , Fatores de Risco , Moduladores Seletivos de Receptor Estrogênico/farmacologia , Sensibilidade e Especificidade , Tamoxifeno/farmacologiaRESUMO
The most important roles of ultrasound in breast imaging include the diagnosis of cysts and the characterization of masses that have been incompletely assessed by mammography. Ultrasonography techniques such as harmonic and compound imaging have recently been introduced and are more efficient than conventional imaging in terms of lesion conspicuity and the characterization of breast nodule. The BI-RADS classification is an important system for describing and classifying breast lesions. With this approach, a population of benign solid breast lesions that does not require biopsy can be accurately defined. Ultrasonography should be performed as first-line examination in juvenile, in pregnant women and in patients with inflammatory syndrome. Ultrasound can detect mammographically occult breast the way they develop.
Assuntos
Neoplasias da Mama/diagnóstico por imagem , Ultrassonografia Mamária , Doenças Mamárias/diagnóstico , Doenças Mamárias/diagnóstico por imagem , Doenças Mamárias/patologia , Neoplasias da Mama/classificação , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/patologia , Feminino , Humanos , Mamografia/métodos , Sensibilidade e Especificidade , Ultrassonografia Mamária/métodosRESUMO
We have investigated the inotropic effects of digoxin, digitoxin and ouabain in cat ventricular muscle under conditions of reduced Na influx in an effort to determine the role of Na in the positive inotropic effect of these cardiac glycosides. When the normal, Na-dependent action potential is inactivated by potassium depolarization, these glycosides retain a positive inotropic effect. In contrast, when muscles are bathed in Na-poor or Na-free solutions, these glycosides do not influence contraction. This suggests that the cardiac glycosides are dependent on Na for their positive inotropic effects.
