Browsing by Author "Silva, Mariana"
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- Development of biosensors for functional textile applicationsPublication . Nascimento, Ana; Abreu, Cristina; Silva, Mariana; Leite, Bárbara; Rouly, Simon; Ferraz, Ricardo; Costa, Miguel; Prudêncio, Cristina; Parente, Elsa; Vieira, MónicaSARS-CoV-2, the cause of the disease COVID-19, has a high level of contagiousness, and has been verified as a major epidemiological threat. In order to reduce the spread of the virus, the entire population was advised to use personal protective equipment, among which are the face masks. The eficacy of masks depend on the time of use, amount of moisture and contact with infectious agents. The objective of this study is the development of a colorimetric biosensor, based on biological reactions that detect a given analyte through color change. This biosensor will be incorporated in a textile surface, with the capacity of direct indication of the protection effectiveness of the face masks, giving the user information about the filtration level of the equipment, with a humidity sensor; and of the contamination space, with a sensor to detect the presence of the virus. Thus, a biosensor for SARS-CoV-2 is intended to indicate the contact with the virus. It was developed based on gold nanoparticles functionalized with sialic acid, to be coupled with a humidity biosensor and previously presented to scientific community. The humidity biosensor is intended to contribute to reduce the risk spread and contagion of the disease, by monitoring the effectiveness of the protection of the masks, since humidity causes the degradation of the filtering quality of the masks. For the development of the humidity biosensor, two approaches were adapted: clay and silica mesoporous, which will be impregnated, together with the SARS-CoV-2 biosensor, on a textile surface, and then incorporated into the textile mask. The developed biosensor appears to be more reliable through silica-based technology with methylene blue dye, is aligned with the Portuguese standard for textile face masks that indicate up to 4 hours of use and [85±5]% of maximum relative humidity, as maximum levels expected for the inutilization of the masks. After reaching this humidity the biosensor changes color, indicating to us the need for mask replacement.
- Dor musculosquelética lombar e qualidade de vida em praticantes de musculaçãoPublication . Alves, André; Silva, Mariana; Nascimento, Ana Paula; Bohn, Lucimére; Miranda, LeonorA prática de musculação aparece ligada a benefícios para a saúde e bem-estar, mas também surge associada a queixas de dor musculoesquelética lombar (Scriven et al., 2004), podendo estas ter impacto na participação ocupacional e na qualidade de vida (QdV). A terapia ocupacional, tanto numa perspetiva de prevenção como de intervenção, visa a promoção da participação ocupacional e da qualidade de vida (Gomes et al., 2004).
- Overexpression of tumour-associated carbohydrate antigen sialyl-Tn in advanced bladder tumoursPublication . Ferreira, José Alexandre; Videira, Paula; Lima, Luís; Pereira, Sofia; Silva, Mariana; Carrascal, Milene; Severino, Paulo; Fernandes, Elisabete; Almeida, Andreia; Costa, Céu; Vitorino, Rui; Amaro, Teresina; Oliveira, Maria José; Reis, Celso; Dall'Olio, Fabio; Amado, Francisco; Santos, LúcioLittle is known on the expression of the tumour-associated carbohydrate antigen sialyl-Tn (STn), in bladder cancer. We report here that 75% of the high-grade bladder tumours, presenting elevated proliferation rates and high risk of recurrence/progression expressed STn. However, it was mainly found in non-proliferative areas of the tumour, namely in cells invading the basal and muscle layers. STn was also found in tumour-adjacent mucosa, which suggests its dependence on a field effect of the tumour. Furthermore, it was not expressed by the normal urothelium, demonstrating the cancer-specific nature of this antigen. STn expression correlated with that of sialyltransferase ST6GalNAc.I, its major biosynthetic enzyme. The stable expression of ST6GalNAc.I in the bladder cancer cell line MCR induced STn expression and a concomitant increase of cell motility and invasive capability. Altogether, these results indicate for the first time a link between STn expression and malignancy in bladder cancer. Hence, therapies targeting STn may constitute new treatment approaches for these tumours.
- Perceptions of music students about the effects of loud music and protective practicesPublication . Rodrigues, Matilde; Silva, Mariana; Silva, Paula; Gomes, Rui; Prior, Ana; Ignacio, OctavioAs with professional musicians, also students can be exposed to dangerous sound pressure levels in the course of their academic activity, which can result in hearing damages. However, there are very few studies focused on the problem of music students’ exposure to loud music, particularly about the students’ perceptions and behaviours. In view of this, this study attempts to analyse the perceptions of the students about loud music risks, as well as to characterize their preventive behaviours and health effects. To analyse this issue, a questionnaire was developed and applied to music students of a secondary school. 123 students participated in the study. The results showed that most of students perceive ensemble classes and group study as noisy. However, several students assessed the sound levels in the different classes and in the additional study as low or moderate. Brass and percussion were identified as the noisiest instruments and strings were perceived as producing low and moderate sound pressure levels. The results also showed that only a part of the students were concerned with the health effects related to the exposure to high sound levels and the majority reported do not use hearing protection, since they never tried to use it or they seen it as non-necessary. The findings of this study showed that music students are not entirely aware of the risks associated with the exposure to high noise levels in the course of their practice and a strategy to improve protective behaviours need to be implemented in the music schools.
- Qualidade do sono e dor lombar inespecífica em trabalhadores portuguesesPublication . Almeida, Paula; Figueiras, Benedita; Silva, Mariana; Faria, Brígida Mónica; Bohn, Lucimére; Miranda, LeonorO sono tem um papel fundamental na saúde e no desempenho das atividades de vida diária, tal como o trabalho, e podem ser comprometidos pela dor. A dor lombar inespecífica tem sido referida como uma das maiores justificações para a incapacidade no trabalho.
- Response of high-risk of recurrence/progression bladder tumours expressing sialyl-Tn and sialyl-6-T to BCG immunotherapyPublication . Lima, Luís; Severino, Paulo; Silva, Mariana; Miranda, Andreia; Tavares, Ana; Pereira, Sofia; Fernandes, Elisabete; Cruz, Ricardo; Amaro, Teresina; Reis, Celso; Dall'Olio, Fabio; Amado, Francisco; Videira, Paula; Santos, Lúcio; Ferreira, José AlexandreHigh risk of recurrence/progression bladder tumours is treated with Bacillus Calmette-Guérin (BCG) immunotherapy after complete resection of the tumour. Approximately 75% of these tumours express the uncommon carbohydrate antigen sialyl-Tn (Tn), a surrogate biomarker of tumour aggressiveness. Such changes in the glycosylation of cell-surface proteins influence tumour microenvironment and immune responses that may modulate treatment outcome and the course of disease. The aim of this work is to determine the efficiency of BCG immunotherapy against tumours expressing sTn and sTn-related antigen sialyl-6-T (s6T). METHODS: In a retrospective design, 94 tumours from patients treated with BCG were screened for sTn and s6T expression. In vitro studies were conducted to determine the interaction of BCG with high-grade bladder cancer cell line overexpressing sTn. RESULTS: From the 94 cases evaluated, 36 had recurrence after BCG treatment (38.3%). Treatment outcome was influenced by age over 65 years (HR=2.668; (1.344-5.254); P=0.005), maintenance schedule (HR=0.480; (0.246-0.936); P=0.031) and multifocality (HR=2.065; (1.033-4.126); P=0.040). sTn or s6T expression was associated with BCG response (P=0.024; P<0.0001) and with increased recurrence-free survival (P=0.001). Multivariate analyses showed that sTn and/or s6T were independent predictive markers of recurrence after BCG immunotherapy (HR=0.296; (0.148-0.594); P=0.001). In vitro studies demonstrated higher adhesion and internalisation of the bacillus to cells expressing sTn, promoting cell death. CONCLUSION: s6T is described for the first time in bladder tumours. Our data strongly suggest that BCG immunotherapy is efficient against sTn- and s6T-positive tumours. Furthermore, sTn and s6T expression are independent predictive markers of BCG treatment response and may be useful in the identification of patients who could benefit more from this immunotherapy.