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Los gestágenos clásicamente han sido relacionado con el cáncer mamario. Por esto, cuando se requiere indicar un anticonceptivos hormonal en una paciente tratada por cáncer de mama, surge la opción del uso de anticonceptivos con gestágenos solos (POP). Algunos estudios sugieren un rol protector de los gestágenos en el cáncer de mama: 1) La progesterona inhibe la proliferación mamaria inducida por el estradiol. 2) Induce apoptosis celular, inhibiendo la síntesis de las proteínas antiapoptóticas, 3) Inhibe enzimas que aumentan la concentración de estrógenos en la mama. Contrariamente, otras investigaciones muestran una acción favorecedora del cáncer de mama: 1) La actividad mitótica en las mamas es máxima durante la fase lútea, período en que predomina la progesterona. 2) En cultivos celulares los gestágenos estimulan la proliferación de algunas líneas celulares de cáncer de mama. 3) El uso de anticonceptivos orales con progestágenos y la medroxiprogesterona de depósito aumentan en mujeres jóvenes el riesgo de cáncer mamario. 4) En el reemplazo hormonal postmenopáusico varios estudios sugieren que la medroxiprogesterona incrementa el riesgo oncogénico. Conclusión: No existen datos que permitan afirmar con certeza que el uso de POP no tiene riesgos en pacientes con cáncer de mamaEstrogens classically have been related to breast cancer. For this reason, when a hormonal contraceptive needs to be prescribed in a patient for breast cancer. Progestin Only Pill (POP) as an option arises. Some studies suggest a protective rol of progestins for breast cancer: 1) Progesterone inhibits mammary proliferation induced by estradiol, 2) It induces cellular apoptosis, inhibiting the synthesis of antiapoptotic proteins, 3) It inhibits enzymes that increase estrogenic concentration in breast. Contrarily, other investigations show a favorable action for breast cancer: 1) Mitotic activity in the breast is increased during the luteal phase, period in which progesterone prevails, 2) In cellular cultures progestins stimulate the proliferation of some lines of breast cancer cells, 3) The use of oral contraceptives with progestins and medroxyprogesterone increases in young women the risk for breast cancer, 4) In postmenopausal hormonal replacement, several studies suggest that medroxyprogesterone increases oncogenic risk. Conclusion: There are no convicing data confirming that the use of POP has no risk for patients with breast cancer

The Madeira Airport runway has recently been extended with a 1,000 m long structure over the Atlantic Ocean supported by concrete columns. To prevent aircraft from falling down special lateral reinforced concrete safety barriers were designed. In order to study the efficiency of these barriers in accident situations, small-scale models of the runway, safety barriers, and most frequent aircraft were tested at the Structures and Materials Resistance Laboratory of IST (Instituto Superior Tecnico), in collaboration with LNEC (the Portuguese National Laboratory of Civil Engineering), the Airbus Company, TAP (Air Portugal), and the Madeira airport authorities (ANAM). The paper presents this study, including an initial evaluation of a set of aircraft accident related statistics from the International Civil Aviation Organization (ICAO) databases, the results of the tests performed at the TAP simulator of Airbus A-320, and the preparation and main results of the experimental small-scale tests at IST. It was concluded that, under specific conditions, the designed safety barriers were efficient in preventing aircraft from falling during landing and takeoff accidents. CE Database subject headings: Safety; Barriers; Airport runways; Accidents; Model tests; Aircraft.

Objective: The aim of this study was to design and validate a questionnaire to measure perceived symptoms associated with antihypertensive drugs (PERSYVE). Methods: The PERSYVE development and validation included four stages: 1) item development (bibliographic review and questionnaire elaboration); 2) face and content validation; 3) field testing (pre-test); and 4) test-retest validation, assessment of internal consistency (Cronbach’s alpha) and reproducibility over time (intraclass correlation coefficient and Cohen’s kappa coefficient). Results: PERSYVE is divided into six sections according to results obtained from the literature review: (1) drug adherence, (2) perceived symptoms and how they affect quality of life (five-point Likert scale), (3) communication with health professionals, (4) perception of symptoms as adverse reactions, (5) influence on therapy compliance, and (6) adoption of non-pharmacological methods for blood pressure control. Content and face validation of the questionnaire led to some vocabulary changes and the introduction of section 2.1. Field-testing (n=26) revealed high comprehensibility of the questions. The Cronbach's alpha, calculated for section 2 (five-point Likert scale) was 0.850. PERSYVE was reproducible (n=167): kappa values presented fair to substantial reproducibility and, in section 2, ICC values resulted in good to excellent reproducibility. Conclusion: Results showed that PERSYVE is a well-structured, objective, patient-friendly, valid and reliable questionnaire. PERSYVE can be a very useful instrument in hypertensive patients’ monitoring and in the screening of adverse effects.

This paper deals with the oscillations of bridge stay cables that may be excited by wind or by traffic-induced periodic motions of the deck and/or towers. A theoretical model is developed for the study of nonlinear oscillations in inclined stay cables as a result of small anchorage motions. Laboratory tests are performed to check the validity of the model in some particular situations. Approximate analytic formulas and numerical solutions are obtained for the cable transverse displacements and the corresponding axial force oscillations. The behavior of inclined stay cables is interpreted by comparison with similar horizontal or vertical cables subjected to appropriate components of the excitation. It is shown that reasonably small anchorage amplitudes may lead to important cable oscillations when conditions are met for lower-order classical or parametric resonance of the cables.