907 research outputs found

    Evidence that human and equine erythrocytes could have significant roles in the transport and delivery of amino acids to organs and tissues

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    Erythrocytes have a well-defined role in the gaseous exchange of oxygen and carbon dioxide in the mammalian body. The erythrocytes can contain more than half of the free amino acids present in whole blood. Based on measures showing that venous erythrocyte levels of amino acids are much less than arterial erythrocyte levels, it has previously been proposed that erythrocytes also play a role in the delivery of amino acids to tissues in the body. This role has been dismissed because it has been assumed that to act as an amino acid transport vehicle, the erythrocytes should release their entire amino acid content in the capillary beds at the target tissues with kinetic studies showing that this would take too long to achieve. This investigation set out to investigate whether the equine erythrocytes could rapidly take up and release smaller packages of amino acids when exposed to high or low external concentrations of amino acids, because it seemed very unlikely that cells would be able to release all of their amino acids without serious impacts on osmotic balance. Freshly prepared erythrocytes were placed in alternating solutions of high and low amino acid concentrations in PBS to assess the capacities of these cells to rapidly take up and release amino acids depending on the nature of the external environment. It was found that amino acids were rapidly taken up and released in small quantities in each cycle representing 15% of their total load in equine erythrocytes and 16% in human erythrocytes. The capacity for rapid uptake/release of amino acids by equine and human erythrocytes provided evidence to support the theory that mammalian erythrocytes have a significant role in transport of amino acids from the liver to tissues, muscles and organs

    Evaluation of the online management course from the perspective of former students

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    Objective To evaluate the online course from the perspective of e-learners as well as the relation between variables. Method A quantitative, descriptive and exploratory study. Results After three years, the satisfaction rates in the three listed categories presented an average rate higher than 75%. The coefficients indicated a high consistency of the questionnaire. Considering the overall rates in the three years period, the Instructor Performance category presented the highest rate. Strong associations between Self-Assessment and Instructor Performance, Self-Evaluation and Program of the Course and Instructor performance and Program of the course were identified. There was no association between the three categories mentioned with any other variables existing in the study. Conclusion E-learners expressed satisfaction with the course that means favored the interaction and the promotion of collective knowledge in nursing management. Also aspects need to be improved, especially the training of the instructor to mediate discussions and encourage student involvement throughout the course.info:eu-repo/semantics/publishedVersio

    Transport of Live Cells under Sterile Conditions Using a Chemotactic Droplet

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    © 2018 The Author(s). 1-Decanol droplets, formed in an aqueous medium containing decanoate at high pH, become chemotactic when a chemical gradient is placed in the external aqueous environment. We investigated if such droplets can be used as transporters for living cells. We developed a partially hydrophobic alginate capsule as a protective unit that can be precisely placed in a droplet and transported along chemical gradients. Once the droplets with cargo reached a defined final destination, the association of the alginate capsule and decanol droplet was disrupted and cargo deposited. Both Escherichia coli and Bacillus subtilis cells survived and proliferated after transport even though transport occurred under harsh and sterile conditions

    Oral glucose tolerance testing at 1 h and 2 h: relationship with glucose and cardiometabolic parameters and agreement for pre-diabetes diagnosis in patients with morbid obesity

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    Background: One hour plasma glucose concentration (1hPG) during an oral glucose tolerance test (OGTT) may be an alternative to 2-h plasma glucose concentration (2hPG) in the identification of individuals at increased risk of hyperglycaemia, although its role is not fully understood. Aim: We aim to investigate the relationship of these measures with other glucose parameters, as well as their relationship with cardiometabolic risk markers and the level of agreement for prediabetes mellitus diagnosis, in a sample of patients with morbid obesity. Methods: We retrospectively evaluated 656 patients with morbid obesity without diagnosed diabetes. To define prediabetes with 2hPG, 2022 American Diabetes Association guidelines criteria were used, while for 1hPG, glucose ≥ 155 mg/dL was considered. Cohen’s Kappa coefficient was used to assess the agreement between both measures of prediabetes mellitus diagnosis. Results: A Cohen’s Kappa coefficient of 0.405 (p < 0.001) was obtained. The 1hPG were positively correlated with homeostatic model assessment for insulin resistance (HOMA-IR) (ρ = 0.281, p < 0.001), fasting plasma glucose (FPG) (ρ = 0.581, p < 0.001), glycated haemoglobin (Hb1AC) (ρ = 0.347, p < 0.001) and were negatively correlated with homeostatic model assessment for cell-β function (HOMA-β) (ρ = −0.092, p = 0.018). 2hPG were also correlated with the same parameters, except for HOMA-β. Conclusion: A fair agreement between 1 and 2hPG was verified. 1hPG criteria may be a useful indicator of β-cell dysfunction and insulin resistance in patients with morbid obesity without diabetes diagnosis. © 2022, The Author(s).Funding text 1: We would like to acknowledge the support of all the endocrinologists, surgeons and nutritionists of the Multidisciplinary Group for Surgical Management of Obesity.; Funding text 2: Isabel Maia holds a PhD Grant (ref: SFRH/BD/117371/2016) co-funded by the Foundation for Science and Technology—FCT (The Portuguese Ministry of Science, Technology and Higher Education) and the POCH/FSE programme

    Supramolecular Presentation of Hyaluronan onto Model Surfaces for Studying the Behaviour of Cancer Stem Cells

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    The supramolecular presentation of extracellular matrix components on surfaces provides a platform for the investigation and control of cell behavior. Hyaluronan (HA) is one of the main components of the extracellular environment and has been shown to play an important role in different cancers and their progression. However, current methods of HA immobilization often require its chemical modification. Herein, a peptide-based self-assembled monolayer (SAM) is used as an anchor to immobilize unmodified HA on a bare gold surface, as demonstrated by the quartz crystal microbalance with dissipation monitoring. Peptide-HA surfaces show increased roughness and greater hydrophobicity when compared to poly-D-lysine/HA surfaces, as measured by atomic force microscopy and water contact angle, respectively. Additionally, the peptide SAM can be micro-contact printed and used to restrict the presentation of HA to specific regions, thereby creating HA patterned surfaces to examine cell behavior. When used for cell culture, these surfaces result in altered adhesion and migration of LUC4 head and neck squamous cell carcinoma cells. These biomimetic surfaces can provide insights into the role of HA in cancer and other diseases and be used as a platform for the development of cell sorting devices.C.O’M. thanks The Queen Mary Institute of Bioengineering and the Engineering and Physical Sciences Research Council for financial support through a Ph.D. studentship (Award number 1502316). J.B. gratefully acknowledges the financial support by Fundação para a Ciência e a Tecnologia (FCT), I.P., through individual contract (CEECIND/03202/2017). This work was also funded by national funds (OE), through FCT, I.P., in the scope of the framework contract foreseen in the numbers 4, 5, and 6 of the article 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of July 19. The authors also acknowledge the financial support from the EU-funded project “SuprHApolymers” (PCIG14-GA-2013-631871).publishe

    Beta Cell Function as a Baseline Predictor of Weight Loss After Bariatric Surgery

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    Background: Obesity is a multifactorial disease, which is strongly associated to other metabolic disorders. Bariatric surgery is the most effective treatment of morbid obesity. The role of beta cell function in weight loss after bariatric surgery is uncertain. Aim: To evaluate the association between beta cell function and percentage of total body weight loss (TBWL%) 1, 2, 3, and 4 years after bariatric surgery in patients with morbid obesity. Methods: Retrospective longitudinal study in patients with morbid obesity followed in our center between January 2010 and July 2018. Patients were excluded if they had diabetes at baseline or missing data on the needed parameters. We evaluated baseline Homeostatic Model Assessment of IR, Homeostatic Model Assessment of ß-cell function (HOMA-beta), Quantitative Insulin Sensitivity Check Index, and Matsuda and DeFronzo index, and TBWL% at years 1 to 4. Linear regression models were used to evaluate the association of indexes of insulin resistance with TBWL% (unadjusted and adjusted for age, sex, BMI, and type of surgery). Results: There were 1,561 patients included in this analysis. HOMA-beta was negatively associated with TBWL% at second, third, and fourth years post-surgery (ß = -1.04 [-1.82 to -0.26], p<0.01; ß = -1.16 [-2.13 to -0.19], p=0.02; ß = -1.29 [-2.64 to 0.06], p=0.061, respectively). This was not observed in the first year post-surgery nor for the other indexes. Glycemia at baseline was positively associated to EWL% at second and third years post-surgery. Conclusion: ß-cell function at baseline seems to be associated to long-term weight loss, explicitly after the first year post bariatric surgery. This might be a helpful predictor of weight loss in clinical practice.The authors would like to thank all the CRIO group members for following these patients: John Rodrigues Preto; Eduardo Jorge Lima da Costa; Hugo Miguel Santos Sousa; André Manuel Costa Pinho; Carla Cristina Oliveira Rodrigues Teixeira Galego; Maria Flora Ferreira Sampaio Carvalho Correia; Cidália Fátima Castro Carção Gil; Diva Bizarro Figueiredo Melim; Eduardo Gil Ferreira Rodrigues Pinto; Marco António Costa Silva; Cristina Sarmento Pontes Martins; Luis Miguel Gonçalves Pereira; Inês Vasconcelos Sousa Magalhães; Isabel Maria Boavista Vieira Marques Brandão; Sertório Manuel Freitas Andrade, and Patrícia Maria Lopes Nunes. The authors would also like to thank the patients and the hospital for their support. The authors would like to thank to Associação dos Amigos do Serviço de Endocrinologia do Hospital de S. João
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