Browsing by Author "Pereira, JM"
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- Carcinoma in situ and early breast carcinoma survey of the Portuguese Senology Society on treatment in Portugal and its evolution between 1985 and 2000Publication . Oliveira, CF; Rodrigues, V; Gervásio, H; Pereira, JM; Albano, J; Amaral, NBy means of a questionnaire sent to Portuguese hospitals which diagnose and treat most female patients with breast cancer, it was intended to assess the situation regarding the treatment of carcinoma in situ and early breast cancer (T1 or T2, N0 or N1), as well as their evolution between 1985 and 2000. The hospital participation rate was 65% and a sample of 865 patients was collected, distributed by the years 1985, 1990, 1995 and 2000. It was observed that, in terms of surgery, there was an increase in conservative surgery, which was over 40% in 2000, as well as an increase in the average of excised axillary lymph nodes. Progress in the surgical approach was similar both in cancer centres and in large and university hospitals, when compared with the other surveyed hospitals. Also, no differences between these two hospital groups in disease-free survival and overall survival were found. Postoperative radiotherapy was employed in more than 90% of the patients submitted to conservative surgery and adjuvant chemotherapy was used in 39% of all the patients, while tamoxifen as adjuvant treatment was used in 58% of the patients.
- Early disrupted neurovascular coupling and changed event level hemodynamic response function in type 2 diabetes: an fMRI studyPublication . Duarte, JV; Pereira, JM; Quendera, B; Raimundo, M; Moreno, C; Gomes, L; Carrilho, F; Castelo-Branco, MType 2 diabetes (T2DM) patients develop vascular complications and have increased risk for neurophysiological impairment. Vascular pathophysiology may alter the blood flow regulation in cerebral microvasculature, affecting neurovascular coupling. Reduced fMRI signal can result from decreased neuronal activation or disrupted neurovascular coupling. The uncertainty about pathophysiological mechanisms (neurodegenerative, vascular, or both) underlying brain function impairments remains. In this cross-sectional study, we investigated if the hemodynamic response function (HRF) in lesion-free brains of patients is altered by measuring BOLD (Blood Oxygenation Level-Dependent) response to visual motion stimuli. We used a standard block design to examine the BOLD response and an event-related deconvolution approach. Importantly, the latter allowed for the first time to directly extract the true shape of HRF without any assumption and probe neurovascular coupling, using performance-matched stimuli. We discovered a change in HRF in early stages of diabetes. T2DM patients show significantly different fMRI response profiles. Our visual paradigm therefore demonstrated impaired neurovascular coupling in intact brain tissue. This implies that functional studies in T2DM require the definition of HRF, only achievable with deconvolution in event-related experiments. Further investigation of the mechanisms underlying impaired neurovascular coupling is needed to understand and potentially prevent the progression of brain function decrements in diabetes.