Percorrer por tipo de recurso "conference poster"
A mostrar 1 - 3 de 3
Resultados por página
Opções de ordenação
- Functional Impact Of APOB Variants In Familial HypercholesterolemiaPublication . Ferreira, Maria Simões; Ramos, Diana; Rato, Inês; Jannes, Cinthia E.; Larrea-Sebal, Asier; Martín, César; Bourbon, Mafalda; Alves, Ana CatarinaFamilial hypercholesterolemia (FH) is an inherited condition of lipid metabolism characterized by increased levels of LDL cholesterol, and APOB variants are responsible for 5%-10% of FH cases. The majority of APOB variants are missense, but nonsense variants and small indels in exon 29 were also identified in individuals with FH phenotype and can be the cause of disease. The aim of this project was to study functionally APOB variants identified in individuals clinical diagnosed with FH in our cohort. LDL was isolated through sequential ultracentrifugation. CHO-ldlA7 cells were transfected with wt LDLR plasmid and incubated with FITC-labeled LDL to determine LDL binding and uptake by flow cytometry. ED-LDLR fragments purified from HEK293 cells were incubated with the APOB variants and antibodies, to determine apoB affinity for LDLR by ELISA assay. Recently we assessed 8 variants: p.(Gln4316*) presented reduced affinity for the LDLR, impairing the binding of apoB to LDLR; p.(Ala1393Val), p.(Asp1456Asn), p.(Met2042Thr), p.(Asp2213del), p.(Ile3374Thr), p.(Val4295Leu) and p.(Arg4519Thr) do not appear to impact apoB's binding to the LDL receptor. Functional studies are essential for assessing the pathogenicity of genetic variants and are one of the key criteria for their classification. These analyses provide crucial data for creating personalized therapeutic strategies. Our goal is to increase the number of characterized variants, beginning with 15 more variants from the Portuguese FH Study.
- Longitudinal dynamics of humoral immunity among health care workers in Portugal using mixed effects modellingPublication . Saraiva, Ana Leonor; Afreixo, Vera; Machado, Ausenda; Gaio, VâniaIntroduction: The emergence of COVID-19 in 2019 led to the rapid development of vaccines and diagnostic tests. To assess antibody responses in healthcare workers (HCWs), a 2021–2022 cohort study was conducted across three Portuguese hospitals. Antibody levels were measured at six intervals: pre-vaccination, post-first dose, at 3, 6, and 12 months after the second dose, and post-booster. Each hospital utilized a different assay: Abbott’s CMIA,, Roche’s Elecsys® ECLIA, and Siemens’ ADVIA Centaur®, leading to challenges in data comparability. The study aimed to harmonize serological data across these hospitals and, through mixed-effects modeling, jointly analyze the longitudinal dynamics of humoral immunity among HCWs in Portugal. Methods: To ensure adequate conversion of antibody titers from different laboratory methods, quantile harmonization, and Deming regression were applied. After harmonization, linear mixed-effects models (LMER) assessed the relationship between antibody levels and covariates, accounting for fixed and random effects. The models included variables such as prior infection, age, hospital, smoking status, contact with COVID-19 patients, and chronic conditions. Sensitivity analyses included models excluding outliers, removing influential points, and applying multiple imputation for missing data. Results: The mixed-effects models demonstrated significant increases in antibody levels following vaccination (β = 21,234; 95% CI: 14,014–28,454; p < 0.001), with an even greater rise observed after the booster dose (β = 33,185; 95% CI: 25,939–40,430; p < 0.001) when compared to the pre-vaccination baseline. Significant differences between hospitals were also evident, as Roche’s Elecsys® ECLIA showed a notably smaller increase at 3 months compared to Abbott’s CMIA (β = -3,285; 95% CI: -5,511 to -1,058; p = 0.004). Interaction plots highlighted how covariates influenced antibody levels over time, revealing higher antibody responses post-vaccination and booster among individuals with prior infection, younger age groups, non-smokers, healthcare workers with direct patient contact, and those without chronic conditions. Sensitivity analyses, such as removing outliers and influential points and applying multiple imputation for missing data, confirmed the robustness and reliability of these findings. Conclusions: The harmonization of antibody measurements enabled a clear evaluation of immune response dynamics among healthcare workers. Vaccination and booster doses significantly increased antibody levels, while differences between hospitals and individual characteristics influenced the magnitude of these responses. These findings enhance our understanding of factors shaping humoral immunity and may guide future vaccination strategies.
- The spread of Aedes albopictus in Portugal: an update of its geographic and seasonal distributionPublication . Costa Osório, Hugo; Soares, Patricia; Freitas, R.; Fernandes, R.; Zé-Zé, Líbia; Amaro, Fátima; Alves, Maria JoãoOver the last two decades, the invasive mosquito Aedes albopictus has spread across Europe. Portugal was the last country in southern Europe to report this species, which was first detected in 2017 under the National Vector Surveillance Network—REVIVE. Despite all the measures taken, its distribution has increased rapidly and in 2023, it was introduced in Lisbon, a major urban centre. As Ae. albopictus is a competent vector for dengue, Zika and chikungunya viruses, monitoring its geographic distribution and seasonal dynamics is crucial for public health risk assessment.