Browsing by Issue Date, starting with "2021-08-17"
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- Lower melanoma pulmonary metastatic burden in obese mice: role of FGF-21Publication . Fonseca, Magda; Soares, Raquel; Coelho, PedroObesity is a risk factor for malignant melanoma. The lungs are main target organs for metastization and their immune response is a key modulator of this mechanism. The concept that the metastatic potential of some types of cancer is reduced or inhibited by obesity, known as the obesity paradox, drives major concerns on the prognosis of metastasized patients. The aim of this study was to investigate how high-fat diet (HFD)-induced obesity affects melanoma metastization. C57Bl6/J mice were fed with HFD or standard diet for 180 days and inoculated intravenously with B16F10 melanoma cells. Upon 21 days of inoculation, lung tissue of overweight and lean mice was assessed for histology and immunohistochemistry assays. Adipokine antibody arrays were performed in mice serum. In vitro RAW 264.7 macrophage cultures were established and incubated with FGF-21 and/or lipopolysaccharide (LPS). Conditioned media was added to B16F10 cells for viability quantification. HFD-fed mice presented a reduced number of metastases with lower proliferative rates. The high content of inflammatory foci observed in noninoculated obese mice was significantly decreased upon B16F10 inoculation, concurrent with a slight fibrosis reduction. Plasma levels of fibroblast growth factor-21 (FGF-21), an endocrine regulator, were elevated in noninoculated HFD mice and the expression of FGF receptor 1 (FGFR-1) was significantly upregulated after inoculation. FGF-21 reduced melanoma viability in LPS-stimulated macrophages. Altogether, these findings suggest that higher amounts of FGF-21 are able to counterbalance the proinflammatory effects associated with obesity, protecting the lungs from melanoma metastization.
- Psychometric properties of the portuguese version of the occupational fatigue exhaustion/recovery (OFER) scale among industrial shift workersPublication . Santos, Joana; Ramos, Catarina; Silva, André; Amorim, Sara; Winwood, Peter; Alberto Alves Carvalhais, CarlosReliable and valid instruments are essential for understanding fatigue in occupational settings. This study analyzed the psychometric properties of the Portuguese version of the Occupational Fatigue Exhaustion/Recovery (OFER). A cross-sectional study was conducted with 260 workers (M = 46.52 ± 13.16 years) from a textile industry, exposed to shift work. Convergent and discriminant validity, internal consistency reliability and exploratory and confirmatory factor analysis were performed. Results showed an adequate fit to data (χ2 (84) = 209,102, CFI = 0.936, GFI = 0.902, RMSEA = 0.076 CI90% (0.063–0.089)), yielding a 13-item, three factor structure. Two items were removed due to low factor loading. The OFER presented an adequate internal consistency, with the subscales presenting good reliability values (Chronic Fatigue (α = 0.81), Acute Fatigue (α = 0.84) and Recovery between Shifts (α = 0.77)). Findings suggest that the Portuguese version of OFER can be a useful tool to assess occupational fatigue of shift workers and prevent work related injuries.
- Detection of alexandrium minutum dinoflagellate in environmental samples using electrochemPublication . Morais, Stephanie L.; Barros, Piedade; Santos, Marlene; Delerue-Matos, Cristina; Gomes, Andreia C.; Barroso, M. FátimaDinoflagellates are aquatic microorganisms that inhabit both salt and fresh waters. These microorganisms are mostly harmless, however, under certain conditions, some species rapidly re produce forming water blooms that not only discolor the waters but also compromise the health of every organism in the vicinity, as some dinoflagellates produce potent toxins deemed unsafe for human health (e.g. Alexandrium minutum). In this work, a disposable electrochemical genosensor for the detection of the toxic dinoflagellate Alexandrium minutum was developed. The analytical plat form methodology consisted in a sandwich format heterogeneous hybridization of complementary DNA sequences assay. The 70 bp A. minutum-specific targeting probe, the 45 bp fluorescein isothi ocyanate-labelled signaling DNA probe and the 25 bp thiolated-DNA-capture probe were designed, after analyzing public databases. To maximize the complementary DNA hybridization and to avoid the formation of strong secondary structures, a mixed mercaptohexanol (MCH) and self-assembled monolayer (SAM) A. minutum-specific DNA-capture probe was immobilized onto disposable screen-printed gold electrodes (SPGE). Using chronoamperometric measurements, the enzymatic amplification of the electrochemical signal was obtained with a concentration range from 0.12 to 1.0 nM, a LD of 24.78 pM with a RSD < 5.2 %. This electrochemical genosensor was successfully applied to the selective analysis of the targeted A. minutum specific region of denatured genomic DNA, ex tracted from toxic dinoflagellates present in the Atlantic Ocean.