Browsing by Issue Date, starting with "2020-06"
Now showing 1 - 10 of 70
Results Per Page
Sort Options
- Cancer patient experience in a nuclear medicine department: comparison between bone scintigraphy and 18F-FDG PET/CTPublication . Grilo, Ana Monteiro; Vieira, Lina Oliveira; Carolino, Elisabete; Costa, Melissa; Galaio, Salomé; Melo, Inês; Geão, Ana; Santos, Andrea; Colarinha, PaulaObjective: To assess the emotional impact on cancer patients undergoing Nuclear Medicine scans and identify how professionals can improve patient experience. Methods: 94 patients undergoing a Bone Scan (BS) or a Positron emission tomography/Computed Tomography (18F-FDG PET/CT) completed two Scan Experience Questionnaires and the State Anxiety Inventory (STAI-S) prior to the scan and after image acquisition. Results: Before the exam, the mean anxiety levels were higher for the BS patients compared to the 18F-FDG PET/CT group. For the post-scan STAI-S mean score, the opposite is true. Both groups experienced a reduction in levels of anxiety after the scan (BS - STAI score pre-scan = 51.75, and post-scan = 36.70; 18F-FDG PET/CT - STAI score pre-scan = 44.67, and post-scan = 38.82). The greatest anxiety factor for the BS group was the duration of the exam - 5.34 ± 2.08 (mean ± SD), while for the 18F-FDG PET/CT group it was the result - 5.40±1.80 (mean ± SD). Conclusion: Patients undergoing NM exams in an oncological context revealed significant anxiety levels prior to and after their scans. However, the BS and 18F-FDG PET/CT have different triggers. It is of extreme importance that healthcare professionals are aware of these peculiarities and adjust their procedures accordingly.
- Corneal tomography in osteogenesis imperfectaPublication . Barão, R.; Marques, R. E.; Mano, S. S.; Firmino, Patrícia; Poças, Ilda Maria; Rodrigues, W.; Fonseca, A. C.; Guerra, P.Osteogenesis Imperfecta (OI) is a rare genetic disorder with musculoskeletal manifestations and some ocular features, such as the presence of blue sclerae, corneal thinning, altered corneal biomechanics, and rare reports of keratoconus (KC). Corneal tomography is essential for KC screening and a BAD_D score over 1,6 and 2,6 is highly sensitive and specific for the detection of subclinical KC and keratoconic corneas, respectively. This study aims to explore the corneal tomographic characteristics of OI patients.
- Glucose homeostasis in obese women is not associated to unacylated ghrelin plasma levelsPublication . Veiga, Luisa; Brito, Miguel; Silva, Carina; Silva-Nunes, JoséIntroduction: Unacylated ghrelin (UAG) is the major form of circulating ghrelin. Initially considered as a nonfunctional peptide, soon after, UAG has been associated with an insulin-sensitizing action and to negative action on energy balance. The aim of this study was to analyze the association between the serum levels of UAG and glucose metabolism parameters in obese women, independently from the eventual influence of anthropometrics. Methods: One hundred lean and 254 obese Caucasian women were studied. Each woman was characterized by anthropometrics, fasting glucose, insulin, HbA1c, and UAG. In addition, obese women were subjected to a classic oral glucose tolerance test (oGTT) to assess glucose and insulin at 120 minutes. Insulin resistance was assessed by the homeostasis model assessment (HOMA-IR). Obese women were classified into three glycemic status subgroups (normoglycemia, prediabetes, and diabetes) according to HbA1c and fasting, and oGTT glucose values. Results: In comparison with the lean group, significantly lower levels of UAG were observed in obese women. However, no significant difference was observed through obesity classes I to III. UAG levels were not significantly different among glycemic status subgroups and did not show any association with glucose, insulin, HOMA-IR, or HbA1c. Conclusions: Although anthropometry can influence the level of the unacylated form of ghrelin, UAG plasma levels do not associate with glucose homeostasis parameters.
- Natural compounds with the capacity to reactivate the gene of gamma-globin and induction of fetal hemoglobin: in vitro testPublication . Matos, Elisabete Cristina Conceição de; Brito, Miguel; Ribeiro, EdnaABSTRACT - β-hemoglobinopathies are the most common recessive genetic diseases worldwide. Currently available treatments for these disorders are expensive and associated with severe side effects. Pharmacological reactivation of Fetal Hemoglobin (HbF) is seen as a promising therapeutic strategy. Hydroxyurea (HU), a potent ribonucleotide reductase inhibitor, is the only Food and Drug Administration (FDA) approved HbF inducing agent. However, its cytotoxicity, potential carcinogenicity, and variable clinical effects limit severely its use. Identification of novel agents, with higher HbF inducing activity, lower cytotoxicity, and availability in low-income countries, such as natural compounds, has become a great challenge today. Here, we performed an assessment of potential transcriptional effects induced by two natural bioactive compounds, namely Genistein (GN) a naturally occurring flavonoid found in soybean and soy derivates, and Epigallocatechin-3-gallate (EGCG) the major polyphenol component of green tea, in globin and HbF regulators/silencer genes. K562 cell line was exposed for 72 and 96 hours to three different concentrations of GN and EGCG that mimic cellular exposure in vivo after supplementation (100 ƞg/ml, 250 ƞg/ml and 500 ƞg/ml), and 25 μg/ml HU was used as a positive control. Cell viability and proliferation were measured and the transcriptional effects of GN and EGCG on α, β, and γ-globin genes, as well as the HbF regulators genes BCL11A and KLF1, were evaluated by qRT-PCR using specific primers. Our results demonstrated that both compounds impact cellular metabolism and proliferation with no cytotoxic effects and have a potential specific molecular target for BCL11A with associated downregulation, without altering KLF1 levels. GN and EGCG also affected globin expression levels in a dose and time-dependent manner. Interestingly, transcriptional analysis of both compounds revealed non-monotonic dose-responses (NMDRs). Overall, our preliminary study sustains the potential of these compounds for γ-globin reactivation and consequently HbF induction, which indicates that GN and EGCG may be potential candidates for new therapeutic strategies. Further research must be performed in order to assess the effectiveness of HbF induction and the underlying molecular mechanisms.
- Temperature distribution of a Fast-Field Cycling Nuclear Magnetic Resonance relaxometer's electromagnet with reduced volumePublication . Videira, P.; Sebastião, P.; Roque, A.; Sousa, D. M.; Fernandes, A.; Margato, ElmanoThe temperature distribution of a Fast Field Cycling (FFC) Nuclear Magnetic Resonance (NMR) electromagnet plays an important role in the operation of this type of apparatus. The designed electromagnet presents a reduced volume and is iron and copper based, fulfilling the technical requirements for the magnetic field. With this solution, it is possible to increase the overall performance in comparison with former similar FFC relaxometers. Electromagnet's simulation results evaluating the temperature distribution, heating effects and cooling requirements are presented.
- HIV, hepatitis B virus, hepatitis C virus, and syphilis among pregnant women attending antenatal care in Luanda, Angola: seroprevalence and risk factorsPublication . Sebastião, Cruz S.; Neto, Zoraima; Jandondo, Domingos; Mirandela, Marinela; Morais, Joana; Brito, MiguelInfectious diseases during pregnancy remain a public health concern, especially in a resource-limited setting. The study aimed to determine the seroprevalence and determinants of HIV and co-infection with hepatitis B virus (HBV), hepatitis C virus (HCV), and syphilis among pregnant women attending antenatal care in Luanda, the capital city of Angola. A cross-sectional study was conducted with 1612 pregnant women screened for HIV during antenatal care. HIV-reactive were also screened for HBV, HCV, and syphilis using immunoassay kits. A logistic regression model, adjusted odds ratios (AOR) and their 95% confidence interval (CI) were calculated with a level of significance set at 5%. The overall seroprevalence of HIV was 2.6%. About 13% of HIV-positive pregnant women were coinfected. From which, 7.5% were reactive to HBV and 5% to syphilis. There was no reactivity to HCV. Pregnant women younger aged than 25 years were significantly protected from HIV-infection (AOR, 0.43 [95% CI, 0.20-0.91], P = .026). The co-infection was 1.3 times (AOR, 0.04-41.0) in younger aged than 25 years, 7.0 times (AOR, 0.50-99.2) to residents in urbanized areas, and 1.4 times (AOR, 0.10-20.9) in pregnant women with a high educational level. In conclusion, infectious diseases are a public health burden among pregnant women in Luanda. However, include an integrated antenatal screening mainly in urbanized areas is crucial to reduce the spread of infectious diseases in different communities of Angola.
- Desnutrição, sarcopenia e COVID-19 no idoso: evidência científica da suplementação de vitamina DPublication . Henriques, Inês; Cebola, Marisa; Mendes, LinoIntrodução: Na pandemia de COVID-19, os idosos são considerados uma população de risco acrescido. Situação que se agrava na presença de desnutrição e sarcopenia. A vitamina D pode ser uma potencial adjuvante na prevenção e tratamento de doentes com infeções virais respiratórias, que normalmente apresentam baixos níveis de vitamina D. A suplementação de vitamina D em doentes com COVID-19, poderá ser um passo importante na prevenção e disseminação da infeção. Objetivos: Analisar a evidência sobre a suplementação de vitamina D em idosos com desnutrição, sarcopenia e COVID-19. Metodologia: Analisar a literatura publicada na base de dados eletrónica Pubmed nos últimos 5 anos, utilizando as palavras-chave “covid-19”, “elderly”, “malnutrition”, “sarcopenia” e “vitamin D”. A pesquisa foi realizada entre abril e maio de 2020. Resultados: A suplementação de vitamina D, em caso de carência, demonstrou um efeito benéfico na melhoria da função muscular e na redução da severidade e mortalidade por infeções respiratórias. Quando associada à proteína e ao exercício físico, apresentou um possível efeito sinérgico na quantidade e qualidade muscular. Em doentes com COVID-19, nas quais foram relatadas concentrações mais baixas de 25 (OH) D, verificou-se um aumento da mortalidade e da incidência da doença. Conclusões: A evidência existente é pouco conclusiva e não é suficiente para estabelecer uma relação direta entre a deficiência de vitamina D e o risco de incorrer em COVID-19 no futuro. São necessários ensaios clínicos na população humana para estudar essa hipótese e inclusive perceber a influência da malnutrição e sarcopenia.
- Growth theory under heterogeneous heuristic behaviorPublication . Gomes, OrlandoOver the last decades, conceptual frameworks formulated to address the dynamics of economic growth have hypothesized, discussed and tested a large number of different assumptions concerning the role of capital accumulation, labor productivity, learning-by-doing, formal education, innovation, and diffusion of ideas. Underlying all these theoretical contributions is, on the demand side, a pervasive and apparently unshakable structure of analysis: economic agents invariably set an optimal intertemporal consumption plan which allows then to maximize utility over an infinite horizon. Such behavior, however, suggests a planning ability that agents often lack. In fact, household decisions are frequently designed on the basis of heuristics or rules-of-thumb that, although not optimal, are reachable under the cognitive constraints typically faced by human beings. This paper revisits some of the most prominent models of the mainstream growth theory, taking a specific heuristic to account for consumption-savings decisions. The heuristic, which allows for the consideration of distinct profiles of saving behavior across individual agents, is a static rule, which might suggest a return to a Solow-like growth analysis. Notwithstanding, the adopted rule-of-thumb encloses a series of novel and relevant implications for growth theory. Such implications are duly highlighted and discussed in this study.
- Phenolic profile and biological activities of decoctions from Santolina impressa, a Portuguese endemic speciesPublication . Rodrigues, Ana M.; Fale, Pedro; Madeira, Paulo; Pacheco, Rita; Florêncio, Maria Helena; Ascensão, Lia; Serralheiro, Maria LuisaSantolina impressa Hoffmanns & Link is an aromatic Asteraceae species endemic to the southwest of Portugal. It is used in folk medicine as an herbal tea for gastrointestinal ailments and mouthwash antiseptic. The present study aimed to relate the chemical composition of decoctions from the aerial parts S. impressa with their antiacetylcholinesterase, antioxidant, antimicrobial and cytotoxic activities, in an attempt to explain the traditional use of this species. LC–MS/MS analysis identified chlorogenic acid and cynarin as the main components. Antimicrobial activity of the extracts was investigated against two cariogenic bacteria:- Streptococcus sobrinus and Streptococcus mutans, and these decoctions were not cytotoxic towards Caco-2 and HepG2 cell lines. Decoctions from capitula and stems/leaves showed high AChE inhibition, with IC50 values of 328 μg/mL and 579 μg/mL, respectively. The antioxidant activity measured using the DPPH radical scavenging assay showed an EC50 of 14.7 μg/mL and 12.9 μg/mL for capitula and stems/leaves extracts, respectively. The biological activities were kept constant after in vitro digestive process and the HPLC analysis did not indicate changes in the extract’s chemical composition. The results may explain the traditional use of S. impressa decoctions for digestive problems and as a mouthwash antiseptic.
- Experimental analysis of wave energy converters concentrically attached on a floating offshore platformPublication . Kamarlouei, M.; Gaspar, José; Calvário, Miguel; Hallak, T. S.; Mendes, Mário J. G. C.; Thiebaut, F.; Soares, Carlos GuedesThis paper presents an initial experimental study of wave energy converters concentrically arranged and attached on a floating offshore platform model. The 1:27 scale model, has been designed, built and tested, in two main situations, without and with twelve cone shape wave energy converters. To simulate the power take-off system in each wave energy converter, rotational friction dampers have been installed on the joints of the floaters arms to the platform deck. The experimental results show that the interaction between buoys and platform have a positive effect on the platform heave and pitch motions. However, the reduction in heave and pitch motions of the platform, after installing the wave energy converter array, depends on the damping of the equivalent power take-off system. Thus, the effect of dampers in the motion of buoys is presented to allow an initial understanding of the required damping range of the power take-off system and related control strategies.