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In the aftermath of the pandemic, teleworking in Portugal maintains a very high standard of adherence among workers and employers, with the contribution of dedicated legal frameworks, as these new ways of working continue to encourage innovative workspace configurations in the territories, triggering new urban dynamics, particularly significant to our observation. The thematic dossier opening this 46th issue of CIDADES, Comunidades e Territórios offers a set of contributions on this issue. “W...

Dissertação de Mestrado Integrado em Medicina Veterinária, na área científica de Clínica RESUMO - O politrauma é uma condição comum de emergência em animais de companhia, que está frequentemente associada a uma elevada taxa de morbilidade e de mortalidade comparativamente a traumas menores. O presente estudo foi realizado numa amostra de 20 cães politraumatizados (N=20), de ambos os géneros, admitidos no Centro de Medicina Veterinária Anjos de Assis – CMVAA, e teve como objetivos caracterizar a amostra do ponto de vista epidemiológico para os parâmetros de idade, género, raça, tipo de trauma, causa de trauma, e taxa de sobrevivência ao momento da alta clínica; e determinar qual a relação entre os parâmetros do cálcio ionizado (iCa) e o dióxido de carbono total (tCO2), e se eles possuem algum valor como indicadores de prognóstico em cães politraumatizados em relação à taxa de sobrevivência. De acordo com os resultados a amostra foi equitativa para ambos os géneros, teve uma média de idade de 6.5 ± 2 anos, a maioria dos doentes eram sem raça definida, o tipo de trauma mais frequente foi o rodoviário e apresentaram uma taxa de sobrevivência de 75%. Os resultados apontam para uma associação significativa (p = 0.001) do iCa e do tCO2 com a taxa de sobrevivência, assim como a existência de uma forte correlação negativa entre os dois parâmetros, podendo os mesmo funcionarem como indicadores de prognóstico em cães politraumatizados ABSTRACT - Preliminary study of the variation of total carbon dioxide and ionized calcium in polytraumatized dogs and their roles as prognostic factors - Polytrauma is a common emergency condition in small animals that is frequently associated with higher morbidity and mortality rates compared to minor trauma. The present study was carried out in a sample of 20 polytraumatized dogs (N=20), of both genders, admitted to Centro de Medicina Veterinária Anjos de Assis – CMVAA, and aimed to characterize the sample for age, gender, breed, type of trauma, cause of trauma, and survival rate to clinical discharge; and to determine the correlation between ionized calcium (iCa) and total carbon dioxide (tCO2) , and the value of this 2 parameters as prognostic indicators in polytraumatized dogs in relation to the survival rate. According to the results the sample was equitable for both genders, had a mean age of 6.5 ± 2 years, most patients were mixed breed, the most frequent type of trauma was motor vehicle accident, and the survival rate was 75%. The results point to a significant association (p = 0.001) between iCa and tCO2 and the survival rate as well as the existence of a strong negative correlation between the two parameters which my function as prognostic indicators in polytraumatized dogs N/A

IgG molecules are crucial for the human immune response against bacterial infections. IgGs can trigger phagocytosis by innate immune cells, like neutrophils. To do so, IgGs should bind to the bacterial surface via their variable Fab regions and interact with Fcγ receptors and complement C1 via the constant Fc domain. C1 binding to IgG-labeled bacteria activates the complement cascade, which results in bacterial decoration with C3-derived molecules that are recognized by complement receptors on neutrophils. Next to FcγRs and complement receptors on the membrane, neutrophils also express the intracellular neonatal Fc receptor (FcRn). We previously reported that staphylococcal protein A (SpA), a key immune-evasion protein of Staphylococcus aureus, potently blocks IgG-mediated complement activation and killing of S. aureus by interfering with IgG hexamer formation. SpA is also known to block IgG-mediated phagocytosis in absence of complement, but the mechanism behind it remains unclear. In this study, we demonstrate that SpA blocks IgG-mediated phagocytosis and killing of S. aureus and that it inhibits the interaction of IgGs with FcγRs (FcγRIIa and FcγRIIIb, but not FcγRI) and FcRn. Furthermore, our data show that multiple SpA domains are needed to effectively block IgG1-mediated phagocytosis. This provides a rationale for the fact that SpA from S. aureus contains four to five repeats. Taken together, our study elucidates the molecular mechanism by which SpA blocks IgG-mediated phagocytosis and supports the idea that in addition to FcγRs, the intracellular FcRn is also prevented from binding IgG by SpA.

Starting the summer of 2022, a time traditionally marked by the return of emigrants to Portugal for the holidays, the 44th issue of CIDADES, Comunidades e Territórios presents a thematic dossier dedicated to Return migration to Portugal, organized by Liliana Azevedo, Amandine Desille and Filipa Pinho. Revisiting the past to understand the present is not just a support subtitle to the dossier’s theme. It is above all an approach to overcome the less worked research perspectives on return migra...

Antibiotic resistance is a major problem for public health. Staphylococcus aureus, commonly known as “multi-drug resistant bacterium” or simply as “super bug”, is one of the pathogens for which new antibiotics and other therapeutic options are urgently needed. S. aureus can cause mild to life-threatening diseases that include skin and soft tissue infections, pneumonia, infective endocarditis, osteomyelitis and sepsis. Although our immune defenses protect our body from invading bacteria, some pathogens, like S. aureus, have evolved strategies to evade the host immune system. One particularly important immune evasion factor of S. aureus is staphylococcal protein A (SpA). SpA binds to the constant region of antibodies to prevent phagocytic cells from recognizing S. aureus. Antibodies have a variable and a constant region. The variable region can recognize antigens that are secreted by the bacteria, or that are exposed on their surfaces. When antibodies bind to surface antigens via their variable region, their constant region can trigger bacterial clearance by inducing complement activation and by interacting directly with immune cells, like neutrophils. Decoration of the bacteria with antibodies and complement proteins is essential for their recognition by phagocytic cells. Upon recognition, these cells engulf and kill the bacteria intracellularly. In this thesis, we focused on understanding how SpA, by binding to the constant region of antibodies, interferes with antibody- and complement-mediated phagocytosis of S. aureus. The here gained knowledge provides a rationale for optimizing antibody therapies against S. aureus, as alternatives to antibiotics.