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"Sequeira, Joana"
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Probing insulin bioactivity in oral nanoparticles produced by ultrasonication-assisted emulsification/internal gelation
by
Oliveira, Claudia
,
Lira, Tammy
,
Veiga, Francisco
in
Alginates - chemistry
,
Animals
,
biopolymers
2015
Alginate-dextran sulfate-based particles obtained by emulsification/internal gelation technology can be considered suitable carriers for oral insulin delivery. A rational study focused on the emulsification and particle recovery steps was developed in order to reduce particles to the nanosize range while keeping insulin bioactivity. There was a decrease in size when ultrasonication was used during emulsification, which was more pronounced when a cosurfactant was added. Ultrasonication add-on after particle recovery decreased aggregation and led to a narrower nanoscale particle-size distribution. Insulin encapsulation efficiency was 99.3%±0.5%, attributed to the strong pH-stabilizing electrostatic effect between insulin and nanoparticle matrix polymers. Interactions between these polymers and insulin were predicted using molecular modeling studies through quantum mechanics calculations that allowed for prediction of the interaction model. In vitro release studies indicated well-preserved integrity of nanoparticles in simulated gastric fluid. Circular dichroism spectroscopy proved conformational stability of insulin and Fourier transform infrared spectroscopy technique showed rearrangements of insulin structure during processing. Moreover, in vivo biological activity in diabetic rats revealed no statistical difference when compared to nonencapsulated insulin, demonstrating retention of insulin activity. Our results demonstrate that alginate-dextran sulfate-based nanoparticles efficiently stabilize the loaded protein structure, presenting good physical properties for oral delivery of insulin.
Journal Article
Second reported outbreak of pneumococcal pneumonia among shipyard employees in Turku, Finland, August–October 2023: a case–control study
2025
In August 2023, the Finnish Institute for Health and Welfare received reports of a potential cluster of pneumococcal pneumonia cases among shipyard employees in Turku, Finland. Considering a similar outbreak in the same shipyard in 2019, we initiated a case–control study to investigate individual and environmental risk factors specific to this occupational setting in order to inform targeted prevention measures. In total, 14 hospitalized cases were identified from 19 August to 15 October 2023. Streptococcus pneumoniae serotypes 4 and 9 V were isolated from blood cultures of seven cases. Eleven cases and 67 controls working at the shipyard were included in the case–control study. Compared with controls, cases were more likely to be living in an apartment/studio or a hotel/hostel, and less likely in a house or with family. Furthermore, cases were more likely to have a shorter duration of employment (< 1 year) at the shipyard compared to controls. Control measures, including an information and a vaccination campaign, were implemented. We emphasize shipyard-wide hygiene improvements and recommend nationwide consideration of expanding pneumococcal vaccination eligibility to all shipyard construction employees as an occupational high-risk group.
Journal Article
Complex Polysaccharide-Based Nanocomposites for Oral Insulin Delivery
by
Ferreri, Maria Cristina
,
Carissimi, Guzmán
,
Villora, Gloria
in
Aggregation
,
alginate polysaccharide nanocomposite
,
Alginates
2020
Polyelectrolyte nanocomposites rarely reach a stable state and aggregation often occurs. Here, we report the synthesis of nanocomposites for the oral delivery of insulin composed of alginate, dextran sulfate, poly-(ethylene glycol) 4000, poloxamer 188, chitosan, and bovine serum albumin. The nanocomposites were obtained by Ca2+-induced gelation of alginate followed by an electrostatic-interaction process among the polyelectrolytes. Chitosan seemed to be essential for the final size of the nanocomposites and there was an optimal content that led to the synthesis of nanocomposites of 400–600 nm hydrodynamic size. The enhanced stability of the synthesized nanocomposites was assessed with LUMiSizer after synthesis. Nanocomposite stability over time and under variations of ionic strength and pH were assessed with dynamic light scattering. The rounded shapes of nanocomposites were confirmed by scanning electron microscopy. After loading with insulin, analysis by HPLC revealed complete drug release under physiologically simulated conditions.
Journal Article
Perceived Acceptability of Organizational Layoffs and Job Alliances During a Recession: A Mapping of Portuguese People's Views
by
Mullet, Etienne
,
Neto, Joana Margarida Sequeira
in
Acceptability
,
Alliances
,
Business and Management
2018
The present study aimed to explore and map the views of Portuguese laypersons regarding the acceptability of downsizing and restructuring measures during a recession. Two hundred and seven participants with various levels of training in economics were presented with a number of realistic scenarios depicting various measures, and were asked to indicate the extent to which they considered them to be acceptable. The scenarios were created by varying three factors likely to have an impact on people's views: the magnitude of a company's reduction in net sales, the magnitude of planned downsizing, and the way in which downsizing would be implemented, either through layoffs, job alliances or both. Six qualitatively different personal positions were found. Four of these following positions were expected: (1) never acceptable (15 %), (2) mainly depends on the magnitude of downsizing (22 %), (3) mainly acceptable (17 %) and (4) job alliance (8 %). Two unexpected positions were also observed: (5) drastic measures (8 %) and (6) undetermined (29 %).
Journal Article
The Functional Topography of the Arabidopsis Genome Is Organized in a Reduced Number of Linear Motifs of Chromatin States
by
Gutierrez, Crisanto
,
Mendez-Giraldez, Raul
,
Peiró, Ramón
in
Antibodies
,
Arabidopsis
,
Chromatin
2014
Chromatin is of major relevance for gene expression, cell division, and differentiation. Here, we determined the landscape of Arabidopsis thaliana chromatin states using 16 features, including DNA sequence, CG methylation, histone variants, and modifications. The combinatorial complexity of chromatin can be reduced to nine states that describe chromatin with high resolution and robustness. Each chromatin state has a strong propensity to associate with a subset of other states defining a discrete number of chromatin motifs. These topographical relationships revealed that an intergenic state, characterized by H3K27me3 and slightly enriched in activation marks, physically separates the canonical Polycomb chromatin and two heterochromatin states from the rest of the euchromatin domains. Genomic elements are distinguished by specific chromatin states: four states span genes from transcriptional start sites (TSS) to termination sites and two contain regulatory regions upstream of TSS. Polycomb regions and the rest of the euchromatin can be connected by two major chromatin paths. Sequential chromatin immunoprecipitation experiments demonstrated the occurrence of H3K27me3 and H3K4me3 in the same chromatin fiber, within a two to three nucleosome size range. Our data provide insight into the Arabidopsis genome topography and the establishment of gene expression patterns, specification of DNA replication origins, and definition of chromatin domains.
Journal Article
Cochineal reds in Iberia and France: a comparative study of 18th century tin-mordant recipes to dye wool
by
Espírito Santo, Mara
,
Sequeira, Joana
,
Díaz Hidalgo, Rafael
in
18th century
,
Age of Enlightenment
,
Analysis
2025
This research was funded by the Portuguese Foundation for Science and Technology (FCT) through the Associate Laboratory for Green Chemistry (LA/P/0008/2020), Research Unit LAQV REQUIMTE (UID/50006/2023), project REVIVE (2022.01243; https://doi.org/10.54499/2022.01243. PTDC), a CEEC junior contract awarded to Paula Nabais (2021.01344.CEECIND/CP1657/CT0028), an Assistant Researcher contract awarded to Joana Sequeira (Wor(l)ds of Cultural Diversity: Dress and Textiles in Portugal, 13th–15th centuries, DOI: 10.54499/2020.02528.CEECIND/CP1600/CT0016.), and two doctoral grants awarded to Luís Gonçalves Ferreira (grant number 2020.04746.BD; https://doi.org/10.54499/2020.04746.BD) and to Mara Espírito Santo (grant number 2024.02894.BD).
Journal Article
Perceived Legitimacy of Executives Bonuses in Time of Global Crisis: A Mapping of Portuguese People's Views
by
Mullet, Etienne
,
Neto, Joana Margarida Sequeira
in
Bonus systems
,
Bonuses
,
Business and Management
2016
The present study aimed to explore and map the views of Portuguese laypersons regarding the legitimacy of bonuses for senior executives. Two hundred eight participants, with various levels of training in economics, were presented with a number of concrete scenarios depicting the circumstances in which senior executives have received bonuses of variable amounts, and they were asked to indicate the extent to which such bonuses may be considered as legitimate. The scenarios were created by varying four factors likely to have an impact on people's views: (a) the extent to which the objectives fixed by the company have been met or not, (b) the global economic context in which the company has performed, (c) the availability of experienced senior executives in the sector under consideration, and (d) the amount of money that has been awarded, in terms of both the euros and multiples of the average worker's pay. Five qualitatively different personal positions were found. The most common positions were that executive bonuses were either never legitimate (30 %) or not very legitimate (25 %). People without any background in economics were more likely to hold these views than people with a background in economics. The remaining 45 % of the participants supported the awarding of bonus, but their support was conditional, and the main condition was the extent to which the company's objectives were met. Thus for most participants, the practice of awarding extra pay to senior executives was either (a) never legitimate, or (b) legitimate only when the company's objectives have been attained, or (c) legitimate only when, even in a time of economic crisis, the company's objectives have been surpassed.
Journal Article
Dipyrone (Metamizole)-Induced Stevens-Johnson Syndrome
by
Ferreira, Sofia
,
Sequeira, Joana
,
Fernandes, Luís
in
Allergy/Immunology
,
Apoptosis
,
Autoimmune diseases
2024
Stevens-Johnson Syndrome (SJS), a severe mucocutaneous hypersensitivity reaction primarily triggered by drugs, poses a low-incidence, high-mortality challenge. This report explores its clinical nuances and emphasizes supportive care as the mainstay of treatment. A 74-year-old female, burdened with a complex medical history, presented with a non-pruritic macular rash escalating to skin and oral mucosal involvement. A recent introduction of dipyrone (metamizole) implicated drug-induced SJS. Histopathological confirmation guided treatment involving supportive care, corticosteroids, and wound care, resulting in clinical improvement. The case underscores the significance of histopathological confirmation and thorough medication history in navigating SJS complexities, especially in patients with comorbidities like connective tissue disease. A successful multidisciplinary approach and the decision for post-discharge monitoring highlight the intricate management challenges. This case illuminates the intricate interplay of medication-induced hypersensitivity, comorbidities, and management challenges in SJS. Optimal outcomes require prompt diagnosis, trigger identification, and a multidisciplinary treatment approach, emphasizing ongoing research and clinical vigilance.
Journal Article
A case report of severe bleeding due to lupus anticoagulant hypoprothrombinemia syndrome
2020
Association of acquired factor II deficiency and lupus anticoagulant is a rare disease that can be related to sudden, severe or fatal haemorrhage. We present a 74-years-old woman with history of myelodysplastic syndrome, admitted to the Emergency Department due to spontaneous mucocutaneous bleeding. Coagulation assays revealed prolonged prothrombin time and activated partial thromboplastin time with evidence of an immediate acting inhibitor. Antithrombotic therapy usage, drug ingestion, disseminated intravascular coagulation, liver dysfunction and sepsis were excluded. Patient was admitted for close monitoring and etiological evaluation. A comprehensive bleeding diathesis workup was performed showing factor II levels severely decreased and transient positive lupus anticoagulant. Immunosuppression with methylprednisolone lasted for 3 days, followed by prednisolone. After 20 days she was discharged and follow-up was scheduled. Early diagnosis of lupus anticoagulant hypoprothrombinemia syndrome is critical, as it may result in fatal complications if not treated appropriately. There is no consensus regarding the best treatment, most being based on immunosuppression.
Journal Article
Pediatric Thyroidectomy: Experience From a Portuguese Hospital
by
De Carvalho Vaz, Ana
,
Mendes, Catarina
,
Oliveira, Maria João
in
Albinism
,
Cellular biology
,
Data collection
2023
Background and objective Pediatric thyroid disease requiring surgery is rare. Thyroid nodules are a frequent indication for surgery and are mostly benign. However, up to 25% of cases can be malignant. In this study, we aimed to describe our center's experience with regard to pediatric thyroid surgery. Methods This was a retrospective transverse study involving pediatric patients who underwent thyroid surgery at a tertiary hospital between January 2010 and December 2021. Results A total of 14 patients underwent 15 surgeries. The main reason for referral to pediatric endocrinology was thyroid nodules (n=10). Thirteen fine needle aspirations (FNAs) were performed, with follicular tumor (n=6) being the most common finding. The median age of patients at surgery was 15.9 years [interquartile range (IQR): 14.0-16.8]. The most common surgical indications were the presence of a follicular tumor on FNA (n=5) and thyroid nodule size causing symptoms (n=5). There was one case of prophylactic thyroidectomy due to the identification of a multiple endocrine neoplasia type 2A (MEN2A) mutation. The most frequently described histopathology results were follicular adenoma (n=6) and colloid nodular goiter (n=6). Three postoperative complications were observed in three different patients: bilateral lesion of the recurrent laryngeal nerve, cervical hematoma, and transient hypoparathyroidism with hypocalcemia. Conclusion In our study, the most frequent surgical indication was a follicular tumor. A good correlation was found between FNA cytology and final histopathology results, which is in accordance with previous studies. This reinforces the importance of FNA in diagnosis and surgical planning. The rate of complications in our study is comparable to that in larger single-center series in the literature.
Journal Article