Browsing by Author "Barbosa, A"
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- Alergia alimentar a rosáceas e frutos secos: a propósito de um caso clínicoPublication . Carrapatoso, I; Tavares, B; Pereira, C; Rodrigues, F; Barbosa, A; Chieira, C
- Aortic Valve Disease and Vascular Mechanics: Two-Dimensional Speckle Tracking Echocardiographic AnalysisPublication . Leite, L; Teixeira, R; Oliveira-Santos, M; Barbosa, A; Martins, R; Castro, G; Gonçalves, L; Pego, MPURPOSE: Degenerative aortic valve disease (AVD) is a complex disorder that goes beyond valve itself, also undermining aortic wall. We aimed to assess the ascending aortic mechanics with two-dimensional speckle tracking echocardiography (2DSTE) in patients with aortic regurgitation (AR) and hypothesized a relationship with degree of AR. Aortic mechanics were then compared with those of similarly studied healthy controls and patients with aortic stenosis (AS); finally, we aimed to assess the prognostic significance of vascular mechanics in AVD. METHODS: Overall, 73 patients with moderate-to-severe AR and 22 healthy subjects were enrolled, alongside a previously examined cohort (N = 45) with moderate-to-severe AS. Global circumferential ascending aortic strain (CAAS) and strain rate (CAASR) served as indices of aortic deformation; corrected CAAS was calculated as CAAS/pulse pressure (PP). Median clinical follow-up was 438 days. RESULTS: In patients with severe (vs. moderate) AR, CAASR (1.53 ± 0.29/sec vs. 1.90 ± 0.62/sec, P < 0.05) and corrected CAAS (0.14 ± 0.06%/mmHg vs. 0.19 ± 0.08%/mmHg, P < 0.05) were significantly lower, whereas CAAS did not differ significantly. Measurers of aortic mechanics (CAAS, corrected CAAS, CAASR) differed significantly (all P < 0.01) in patients with AS and AR and in healthy subjects, with lower values seen in patients with AS. In follow-up, survival rate of AVD patients with baseline CAASR >0.88/sec was significantly higher (log rank, 97.4% vs. 73.0%; P = 0.03). CONCLUSIONS: Quantitative measures of aortic mechanics were lower for AS patients, suggesting a more significant derangement of aortic elastic properties. In the context of AVD, vascular mechanics assessment proved useful in gauging clinical prognosis.
- Circumferential vascular strain rate to estimate vascular load in aortic stenosis: a speckle tracking echocardiography studyPublication . Teixeira, R; Monteiro, R; Baptista, R; Barbosa, A; Leite, L; Ribeiro, M; Martins, R; Cardim, N; Gonçalves, LEvaluation of vascular mechanics through two-dimensional speckle-tracking (2D-ST) echocardiography is a feasible and accurate approach for assessing vascular stiffening. Degenerative aortic stenosis (AS) is currently considered a systemic vascular disease where rigidity of arterial walls increases. To assess the circumferential ascending aorta strain rate (CAASR) in thoracic aortas of patients with AS, applying 2D-ST technology. 45 patients with indexed aortic valve areas (iAVA) ≤0.85 cm(2)/m(2) were studied. Global CAASR served to assess vascular deformation. Clinical, echocardiographic, and non-invasive hemodynamic data were collected. A follow up (955 days) was also performed. Average age of the cohort was 76. ± 10.3 years, with gender balance. Mean iAVA was 0.43 ± 0.15 cm(2)/m(2). Waveforms adequate for determining CAASR were found in 246 (91 %) of the 270 aortic segments evaluated, for a mean global CAASR of 0.74 ± 0.26 s(-1). Both intra- and inter-observer variability of global CAASR were deemed appropriate. CAASR correlated significantly with age (r = -0.49, p < 0.01), the stiffness index (r = -0.59, p < 0.01), systemic arterial compliance and total vascular resistance. There was a significant positive correlation between CAASR, body surface area (BSA), iAVA, and a negative relationship with valvulo-arterial impedance and E/e' ratio (r = -0.37, p = 0.01). The stiffness index was (β = -0.41, p < 0.01) independently associated with CAASR, in a model adjusted for age, BSA, iAVA and E/e'. Patients with a baseline CAASR ≤0.66 s(-1) had a worse long-term outcome (survival 52.4 vs. 83.3 %, Log Rank p = 0.04). CAASR is a promising echocardiographic tool for studying the vascular loading component of patients with AS.
- Cytogenetic analysis of spontaneously activated noninseminated oocytes and parthenogenetically activated failed fertilized human oocytes--implications for the use of primate parthenotes for stem cell productionPublication . Almeida-Santos, T; Dias, C; Henriques, P; Brito, R; Barbosa, A; Regateiro, FJ; Almeida-Santos, APURPOSE:Spontaneous parthenogenetically activated noninseminated oocytes and failed fertilized oocytes after ART activated by puromycin were studied to assess cleavage ability and the cytogenetic constitution of the resulting embryos. METHODS: Failed fertilized oocytes were exposed to puromycin, and whenever activation occurred, they were further cultured until arrest of development. FISH was used to assess the ploidy of spontaneous (group A) and induced parthenotes (group B). RESULTS: The mean number of oocytes exposed to puromycin and the percentage and type of activation were identical in IVF and ICSI patients. The more frequent types of activation were one or two pronuclei and one polar body suggesting that retention of the second polar body is a common event after parthenogenetic activation. CONCLUSIONS: Retention of the second polar body and chromosome malsegregation were observed after parthenogenetic activation, either spontaneous or induced by puromycin. This means that using parthenogenetic embryos for stem cell research will require great care and attention.