162 research outputs found
Practices and cultures of adaptive governance for rapidly eroding Portuguese coastlines
Portuguese coasts, which are among the most energetic and eroded coastal stretches in Europe, have experienced intense urban and tourist pressure over the last decades. 80% of the coastal population and 85% of GDP are concentrated on coastal stretches. 50% of the urban areas are located within 13km of the coastline, and coastal erosion reaches retreats over 220m in the last 50 years.info:eu-repo/semantics/publishedVersio
Formaldehyde's genotoxicity effects in pathology anatomy technologists and medical pathologists
Formaldehyde (FA) had been considered to be carcinogenic by the International Agency for Research on Cancer (group1), on the basis of sufficient evidence both in humans and in experimental animals, making it a subject of major environmental concern, especially in the occupational context. Manifold in vitro studies clearly indicated that FA is genotoxic, inducing various genotoxic effects in proliferating cultured mammalian cells. Cytokinesis-blocked micronucleus (CBMN) assay is used extensively in molecular epidemiology, and the chromosomal alterations most reported and studied by the CBMN are: micronucleus (MN), nucleoplasmic bridges (NPB) and nuclear buds (NBUDs). The pathology anatomy laboratories are work places that manipulate routinely FA and pathology anatomy technologists and pathologists contact daily with this chemical compound particularly in the macroscopic exam and grossing procedures.
The aim of this study was to identify genotoxicity biomarkers in the set workers groups, such as micronucleus (MN), nucleoplasmic bridges (NPB) and nuclear buds (NBUD) in peripheral blood lymphocytes
Molecular and functional characterization of grapevine NIPs through heterologous expression in aqy-null Saccharomyces cerevisiae
Plant Nodulin 26-like Intrinsic Proteins (NIPs) are multifunctional membrane channels
of the Major Intrinsic Protein (MIP) family. Unlike other homologs, they have low intrinsic water
permeability. NIPs possess diverse substrate selectivity, ranging from water to glycerol and to
other small solutes, depending on the group-specific amino acid composition at aromatic/Arg (ar/R)
constriction. We cloned three NIPs (NIP1;1, NIP5;1, and NIP6;1) from grapevine (cv. Touriga
Nacional). Their expression in the membrane of aqy-null Saccharomyces cerevisiae enabled their
functional characterization for water and glycerol transport through stopped-flow spectroscopy.
VvTnNIP1;1 demonstrated high water as well as glycerol permeability, whereas VvTnNIP6;1 was
impermeable to water but presented high glycerol permeability. Their transport activities were
declined by cytosolic acidification, implying that internal-pH can regulate NIPs gating. Furthermore,
an extension of C-terminal in VvTnNIP6;1M homolog, led to improved channel activity, suggesting
that NIPs gating is putatively regulated by C-terminal. Yeast growth assays in the presence of diverse
substrates suggest that the transmembrane flux of metalloids (As, B, and Se) and the heavy metal (Cd)
are facilitated through grapevine NIPs. This is the first molecular and functional characterization of
grapevine NIPs, providing crucial insights into understanding their role for uptake and translocation
of small solutes, and extrusion of toxic compounds in grapevineinfo:eu-repo/semantics/publishedVersio
Use of European pulses to produce functional beverages – From chickpea and lupin as dairy alternatives
Consumption of plant based products as dairy alternatives is increasing steeply. This diet transition can only be
achieved if these products keep the nutritional value and meet consumer’s sensory acceptance. This work aimed
to evaluate the decrease of the “beany” flavour and of raffinose, stachyose and verbascose contents in EU pulse
beveragés production, and also the best lactic fermentation conditions of the beverages, towards chickpea- and
lupin-based yoghurts, with rheology properties similar to the commercial soy yoghurts. The reduction of “beany”
volatile compounds of chickpea and lupin beverages during processing was confirmed through GC–MS analysis.
Soaking and cooking processes were effective in removing flatulence sugars with almost 48% loss from the initial
content in lupin beverage. The fermentation conditions at 40 ◦C, 12 h and 2% (w/v) of starter concentration
evidenced the best viscoelastic structure and flow properties. The lupin yoghurt-type showed a similar gel
structure to commercial soy yoghurt.info:eu-repo/semantics/publishedVersio
Exposição profissional a formaldeído em laboratórios de anatomia patológica: que realidade em Portugal?
O formaldeído é um gás incolor, solúvel na água e que reage rapidamente com o local de contacto. É utilizado nos laboratórios de Anatomia Patológica (AP) como fixador de células e tecidos - importante local de exposição ocupacional ao formaldeído, nomeadamente por médicos patologistas, técnicos de AP e auxiliares de acção médica. Objectivos do estudo: conhecer a exposição a formaldeído nos laboratórios hospitalares de Anatomia Patológica em Portugal; comparar a frequência de MN em linfócitos do sangue periférico e em células esfoliadas da mucosa bucal dos trabalhadores expostos a formaldeído nos laboratórios de AP – patologistas, técnicos de AP e auxiliares com controlos
Genotoxicity biomarkers in occupational exposure to formaldehyde: the case of histopathology laboratories
Formaldehyde, classified by the IARC as carcinogenic in humans and experimental animals, is a chemical agent that is widely used in histopathology laboratories. The exposure to this substance is epidemiologically linked to cancer and to nuclear changes detected by the cytokinesis-block micronucleus test (CBMN). This method is extensively used in molecular epidemiology, since it provides information on several biomarkers of genotoxicity, such as micronuclei (MN), which are biomarkers of chromosomes breakage or loss, nucleoplasmic bridges (NPB), common biomarkers of chromosome rearrangement, poor repair and/or telomere fusion, and nuclear buds (NBUD), biomarkers of elimination of amplified DNA.
The aim of this study is to compare the frequency of genotoxicity biomarkers, provided by the CBMN assay in peripheral lymphocytes and the MN test in buccal cells, between individuals occupationally exposed and non-exposed to formaldehyde and other environmental factors, namely tobacco and alcohol consumption.
The sample comprised two groups: 56 individuals occupationally exposed to formaldehyde (cases) and 85 unexposed individuals (controls), from whom both peripheral blood and exfoliated epithelial cells of the oral mucosa were collected in order to measure the genetic endpoints proposed in this study.
The mean level of TWA8h was 0.16±0.11ppm (<detection limit until 0.51 ppm) and the mean of ceiling values was 1.14±0.74ppm (0.18–2.93 ppm). All genotoxicity biomarkers showed significant increases in exposed workers in comparison with controls (Mann–Whitney test, p < 0.002) and the analysis of confounding factors showed that there were no differences between genders.
As for age, only the mean MN frequency in lymphocytes was found significantly higher in elderly people among the exposed groups (p = 0.006), and there was also evidence of an interaction between age and gender with regards to that biomarker in those exposed.
Smoking habits did not influence the frequency of the biomarkers, whereas alcohol consumption only influenced the MN frequency in lymphocytes in controls (p = 0.011), with drinkers showing higher mean values. These results provide evidence of the association between occupational exposure to formaldehyde and the presence of genotoxicity biomarkers
Effects of the interaction of tobacco smoke and alcohol consumption on buccal micronucleus in workers exposed occupationally to formaldehyde
Occupational exposure to formaldehyde (FA) has been shown to induce nasopharyngeal cancer and has been classified as carcinogenic to humans (group 1) on the basis of sufficient evidence in humans. Tobacco smoke has been associated to a higher risk of development of cancer, especially in the oral cavity, larynx and lungs, as these are places of direct contact with many carcinogenic tobacco’s compounds. Alcohol is a recognized agent that influence cells in a genotoxic form, been citied as a strong agent with potential in the development of carcinogenic lesions. Epidemiological evidence points to a strong synergistic effect between cigarette smoking and alcohol consumption in the induction of cancers in the oral cavity. Approximately 90% of human cancers originate from epithelial cells. Therefore, it could be argued that oral epithelial cells represent a preferred target site for early genotoxic events induced by carcinogenic agents entering the body via inhalation and ingestion. The MN assay in buccal cells was also used to study cancerous and precancerous lesions and to monitor the effects of a number of chemopreventive agents
From chickpea and lupin as dairy alternatives
Funding text This work was supported by the FCT Project PTDC/BAA-AGR/28370/2017: “Bebida de proteína vegetal a partir de leguminosas europeias com potencial bioativo”; and also through the research unit UID/AGR/04129/2020 – LEAF.Consumption of plant based products as dairy alternatives is increasing steeply. This diet transition can only be achieved if these products keep the nutritional value and meet consumer's sensory acceptance. This work aimed to evaluate the decrease of the “beany” flavour and of raffinose, stachyose and verbascose contents in EU pulse beveragés production, and also the best lactic fermentation conditions of the beverages, towards chickpea- and lupin-based yoghurts, with rheology properties similar to the commercial soy yoghurts. The reduction of “beany” volatile compounds of chickpea and lupin beverages during processing was confirmed through GC–MS analysis. Soaking and cooking processes were effective in removing flatulence sugars with almost 48% loss from the initial content in lupin beverage. The fermentation conditions at 40 °C, 12 h and 2% (w/v) of starter concentration evidenced the best viscoelastic structure and flow properties. The lupin yoghurt-type showed a similar gel structure to commercial soy yoghurt. © 2022publishersversionpublishe
Insights into the selectivity mechanisms of grapevine NIP aquaporins
Nodulin 26-like intrinsic proteins (NIPs) of the plant aquaporin family majorly facilitate the
transport of physiologically relevant solutes. The present study intended to investigate how substrate
selectivity in grapevine NIPs is influenced by the aromatic/arginine (ar/R) selectivity filter within
the pore and the possible underlying mechanisms. A mutational approach was used to interchange
the ar/R residues between grapevine NIPs (VvTnNIP1;1 withUniversidade de Lisboa, VvTnNIP6;1,
and VvTnNIP2;1 with VvTnNIP5;1). Their functional characterization by stopped-flow spectroscopy
in Saccharomyces cerevisiae revealed that mutations in residues of H2/H5 helices in VvTnNIP1;1 and
VvTnNIP6;1 caused a general decline in membrane glycerol permeability but did not impart the
expected substrate conductivity in the mutants. This result suggests that ar/R filter substitution could
alter the NIP channel activity, but it was not su cient to interchange their substrate preferences.
Further, homology modeling analyses evidenced that variations in the pore radius combined with
the di erences in the channel’s physicochemical properties (hydrophilicity/hydrophobicity) may
drive substrate selectivity. Furthermore, yeast growth assays showed that H5 residue substitution
alleviated the sensitivity of VvTnNIP2;1 and VvTnNIP5;1 to As, B, and Se, implying importance
of H5 sequence for substrate selection. These results contribute to the knowledge of the overall
determinants of substrate selectivity in NIPsinfo:eu-repo/semantics/publishedVersio
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