Browsing by Author "Correia, Alexandra"
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- Involvement of the Iron-Regulated Loci hts and fhuC in Biofilm Formation and Survival of Staphylococcus epidermidis within the HostPublication . Oliveira, Fernando; Lima, Tânia; Correia, Alexandra; Silva, Ana Margarida; Soares, Cristina; Morais, Simone; Weißelberg, Samira; Vilanova, Manuel; Rohde, Holger; Cerca, NunoStaphylococcus epidermidis is a major nosocomial pathogen with a remarkable ability to persist on indwelling medical devices through biofilm formation. Nevertheless, it remains intriguing how this process is efficiently achieved under the host’s harsh conditions, where the availability of nutrients, such as essential metals, is scarce. Following our previous identification of two iron-regulated loci putatively involved in iron transport, hts and fhuC, we assessed here their individual contribution to both bacterial physiology and interaction with host immune cells. Single deletions of the hts and fhuC loci led to marked changes in the cell iron content, which were partly detrimental for planktonic growth and strongly affected biofilm formation under iron-restricted conditions. Deletion of each of these two loci did not lead to major changes in S. epidermidis survival within human macrophages or in an ex vivo human blood model of bloodstream infection. However, the lack of either hts or fhuC loci significantly impaired bacterial survival in vivo in a murine model of bacteremia. Collectively, this study establishes, for the first time, the pivotal role of the iron-regulated loci hts and fhuC in S. epidermidis biofilm formation and survival within the host, providing relevant information for the development of new targeted therapeutics against this pathogen
- Metabolic control of T cell immune response through glycans in inflammatory bowel diseasePublication . Dias, Ana M.; Correia, Alexandra; Pereira, Márcia S.; Almeida, Catarina R.; Alves, Inês; Pinto, Vanda; Catarino, Telmo A.; Mendes, Nuno; Leander, Magdalena; Oliva-Teles, MT; Maia, Luís; Delerue-Matos, Cristina; Taniguchi, Naoyuki; Lima, Margarida; Pedroto, Isabel; Marcos-Pinto, Ricardo; Lago, Paula; Reis, Celso A.; Vilanova, Manuel; Pinho, Salomé S.Mucosal T lymphocytes from patients with ulcerative colitis (UC) were previously shown to display a deficiency in branched N-glycosylation associated with disease severity. However, whether this glycosylation pathway shapes the course of the T cell response constituting a targeted-specific mechanism in UC remains largely unknown. In this study, we demonstrated that metabolic supplementation of ex vivo mucosal T cells from patients with active UC with N-acetylglucosamine (GlcNAc) resulted in enhancement of branched N-glycosylation in the T cell receptor (TCR), leading to suppression of T cell growth, inhibition of the T helper 1 (Th1)/Th17 immune response, and controlled T cell activity. We further demonstrated that mouse models displaying a deficiency in the branched N-glycosylation pathway (MGAT5−/−, MGAT5+/−) exhibited increased susceptibility to severe forms of colitis and early-onset disease. Importantly, the treatment of these mice with GlcNAc reduced disease severity and suppressed disease progression due to a controlled T cell-mediated immune response at the intestinal mucosa. In conclusion, our human ex vivo and preclinical results demonstrate the targeted-specific immunomodulatory properties of this simple glycan, proposing a therapeutic approach for patients with UC.
- A methodology for the identification and assessment of the conditions for the practice of outdoor and sport tourism related activities: the case of Northern PortugalPublication . Silva, Goretti; Correia, Alexandra; Rachão, Susana; Nunes, Alcina; Vieira, Elvira; Santos, Sónia; Soares, Luís; Fonseca, Manuel; Ferreira, Fernanda A.; Veloso, Cláudia Miranda; Carrança, Paulo; Fernandes, Paula OdeteTourists’ demand for outdoor sport-related activities has been growing in the last decade, leading to the recognition of the outdoor tourism potential of the development of rural and urban areas where the activities could take place. While the literature has recognized this potential, its features and the existing conditions for its practice are often not fully comprehended, mainly due to the lack of measurement systems and performance indicators. This study addresses this gap by proposing a wide-ranging assessment matrix of nine outdoor-related activities, employing northern Portugal as a study area. Based on an exploratory qualitative analysis employing semi-structured interviews with key stakeholders (public, private and third sector), the main contribution of this study lies in the development of the outdoor tourism assessment matrix (OTAM) to collect data. The OTAM matrix aims to identify and assess the conditions, namely the infrastructure and resources, for the practice of outdoor and sport tourism-related activities within the sustainable development pillars. The nine matrices comprising the OTAM allow the identification of the places where the outdoor activities can be practiced, and the conditions under which they can contribute to the definition of the development strategies of outdoor tourism.
- Outdoor tourism demand segmentation: a case study from North of PortugalPublication . Scalabrini, Elaine; Correia, Alexandra; Nunes, Alcina; Veloso, Cláudia; Vieira, Elvira; Ferreira, Fernanda A.; Silva, Goretti; Fonseca, Manuel; Carrança, Paulo; Santos, Sónia; Fernandes, Paula OdeteThis research aimed to segment the market of visitors who practise outdoor activities in the North region of Portugal based on their motivations. An online survey was conducted between June to September of 2021, with a sample of 200 tourists who realised the region's outdoor activities during this period. The data collected allowed determining factor analysis and the clusters. Two factors: services/hospitality and nature experiences, and three clusters: soft practitioners, radicals, and enthusiasts were delimited. The results show that these groups differ in motivations and practised activities. Segmentation of outdoor tourism demand in North of Portugal should set out marketing and promotion strategies in different destinations, attracting demand from outside the region, and according to their preferences.
- Outdoor tourism in the North of Portugal from the perspective of Tourist Entertainment Companies (TEC)Publication . Martins, Oliva M. D.; Nunes, Alcina; Vieira, Elvira; Rachão, Susana; Correia, Alexandra; Fonseca, Manuel; Silva, Goretti; Santos, Sónia; Veloso, Cláudia; Ferreira, Fernanda A.; Carrança, Paulo; Fernandes, Paula OdeteBased on the perception of those responsible for Tourist Entertainment Companies (TEC), the objective of the research is to contribute to the characterization of Outdoor Tourism (OT). Exploratory qualitative research was carried out through 38 in-depth individual interviews. The territory geography, the experiences, and the internal market were considered relevant aspects. In addition, seasonality and climate were identified as significant factors in defining the offer, which can favour the preservation of the environment. Moreover, the risk of the activities was considered low. The interviewees suggested integrating everyone involved in a network to explore the region's potential, as well as to support activities and promote the region. The radical experience, adventure, and getting out of the routine were identified as motivations for the search, as well as contact with nature and the landscape. The research is limited to the North Region of Portugal, and it brings together the most different needs, desires, and expectations for tourism demand. Strengthening OT can favour employability and, consequently, economic and social balance while promotion of the activity can be explored through the customers' previous experience. The evaluations, testimonials, and word of mouth (WOM) being added value that can be optimized through social networks and digital marketing.
- Preschool hearing screening program: first evidence studyPublication . Neves, Vanessa; Ribeiro, Diana; Oliveira, Natália; Correia, Alexandra; Carvalho, CarlosAccording to the World Health Organization in 2020, 34 million children around the world have deafness or hearing loss, in which 60% of cases can be prevented. This study intends to identify hearing changes in preschoolers who attend the cluster of schools in the Centro Hospitalar Entre Douro e Vouga, CHEDV’s region and to emphasize the value of preschool hearing evaluation in order to prevent longterm effects on the child’s overall development. Currently, this type of screening is not carried out in our country.