4,871 research outputs found

    Mannitol oxidase and polyol dehydrogenases in the digestive gland of gastropods: Correlations with phylogeny and diet

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    Mannitol oxidase and polyol dehydrogenases are enzymes that convert polyalcohols into sugars. Mannitol oxidase was previously investigated in terrestrial snails and slugs, being also present in a few aquatic gastropods. However, the overall distribution of this enzyme in the Gastropoda was not known. Polyol dehydrogenases are also poorly studied in gastropods and other mollusks. In this study, polyalcohol oxidase and dehydrogenase activities were assayed in the digestive gland of 26 species of gastropods, representing the clades Patellogastropoda, Neritimorpha, Vetigastropoda, Caenogastropoda and Heterobranchia. Marine, freshwater and terrestrial species, including herbivores and carnivores were analyzed. Ultrastructural observations were undertake in species possessing mannitol oxidase, in order to investigate the correlation between this enzyme and the presence of tubular structures known to be associated with it. Mannitol oxidase activity was detected in the digestive gland of herbivores from the clades Caenogastropoda and Heterobranchia, but not in any carnivores or in herbivores from the clades Patellogastropoda, Neritimorpha and Vetigastropoda. In most of the species used in this study, dehydrogenase activities were detected using both D-mannitol and D-sorbitol as substrates. Nevertheless, in some carnivores these activities were not detected with both polyalcohols. Ultrastructural observations revealed tubular structures in digestive gland cells of some species having mannitol oxidase activity, but they were not observed in others. Based on our results, we suggest that mannitol oxidase first occurred in a herbivorous or omnivorous ancestor of Apogastropoda, the clade formed by caenogastropods and heterobranchs, being subsequently lost in those species that shifted towards a carnivorous diet.This study was supported by funds provided by the Abel Salazar Institute of Biomedical Sciences (ICBAS) of the University of Porto (Portugal), and by Fundação para a Ciência e Tecnologia (FCT) through the strategic project UID/ MAR/04292/2013 granted to MARE. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

    O papel das associações de pais na educação em ciências: projeto “Ciência & arte nos alimentos”

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    O projeto “Ciência & arte nos alimentos”, aprovado no âmbito do Concurso "Pais com a Ciência", promovido pela Ciência Viva - Agência Nacional para a Cultura Científica e Tecnológica, em colaboração com a CONFAP – Confederação Nacional das Associações de Pais, encontra-se a decorrer, fundamentalmente, no âmbito das Atividades de Tempos Livres desde março 2013 com términus em dezembro 2014. Resultou da parceria estabelecida entre a APEECE de Vila Nova da Barquinha (VNB), o CIEC, o Agrupamento de Escolas de VNB e a Câmara Municipal de VNB, o CIDTFF e o Departamento de Educação da Universidade de Aveiro. O projeto visa fundamentalmente a promoção da cultura científica e tecnológica dos participantes através da exploração de temáticas relacionadas com os alimentos, cujo principal público-alvo são as crianças do 1º CEB

    Use of \u3cem\u3eN\u3c/em\u3e-Alkane Technique to Estimate Sheep Dry Matter Intake

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    Given the complexity of evaluating intake on grazing, some compounds have been studied to promote qualitative and quantitative estimates of animal physiology. In this sense, the technique using n-alkanes as a marker has been used in several animal species, especially in grazing ruminants (Dove and Mayes 1996). By definition, validation under grazing or browsing conditions is not possible, because actual intakes are unknown (Dove and Mayes 2005). Thus, the aim of the study was to evaluate the methodology of n-alkanes to estimate herbage intake by sheep in metabolic cages

    Metal-sensitive and thermostable trypsin from the crevalle jack (Caranx hippos) pyloric caeca: purification and characterization

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    Background: Over the past decades, the economic development and world population growth has led to increased for food demand. Increasing the fish production is considered one of the alternatives to meet the increased food demand, but the processing of fish leads to by-products such as skin, bones and viscera, a source of environmental contamination. Fish viscera have been reported as an important source of digestive proteases with interesting characteristics for biotechnological processes. Thus, the aim of this study was to purify and to characterize a trypsin from the processing by-products of crevalle jack (Caranx hippos) fish.Results: A 27.5 kDa trypsin with N-terminal amino acid sequence IVGGFECTPHVFAYQ was easily purified from the pyloric caeca of the crevalle jack. Its physicochemical and kinetic properties were evaluated using N-alpha-benzoyl-(DL)-arginine-p-nitroanilide (BApNA) as substrate. in addition, the effects of various metal ions and specific protease inhibitors on trypsin activity were determined. Optimum pH and temperature were 8.0 and 50 degrees C, respectively. After incubation at 50 degrees C for 30 min the enzyme lost only 20% of its activity. K-m, k(cat), and k(cat)/K-m values using BApNA as substrate were 0.689 mM, 6.9 s(-1), and 10 s(-1) mM(-1), respectively. High inhibition of trypsin activity was observed after incubation with Cd2+, Al3+, Zn2+, Cu2+, Pb2+, and Hg2+ at 1 mM, revealing high sensitivity of the enzyme to metal ions.Conclusions: Extraction of a thermostable trypsin from by-products of the fishery industry confirms the potential of these materials as an alternative source of these biomolecules. Furthermore, the results suggest that this trypsin-like enzyme presents interesting biotechnological properties for industrial applications.Financiadora de Estudos e Projetos (FINEP/RECARCINE)Petroleo do Brasil S/A (PETROBRAS)Secretaria Especial de Aquicultura e Pesca (SEAP/PR)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundacao de Apoio a Ciencia e Tecnologia do Estado de Pernambuco (FACEPE)Univ Fed Pernambuco, Lab Enzimol LABENZ, Dept Bioquim CCB, BR-50670910 Recife, PE, BrazilUniv Fed Pernambuco, LIKA, BR-50670910 Recife, PE, BrazilUniversidade Federal de São Paulo, Dept Biofis, Escola Paulista Med, BR-04044020 São Paulo, BrazilUniv Fed Pernambuco, Lab Glicoprot, Dept Bioquim CCB, BR-50670910 Recife, PE, BrazilUniversidade Federal de São Paulo, Dept Biofis, Escola Paulista Med, BR-04044020 São Paulo, BrazilWeb of Scienc

    Multiple sclerosis under the age of ten: the challenge of a rare diagnosis in a special population – a case series

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    IntroductionMultiple sclerosis (MS) is a chronic inflammatory demyelinating and degenerative disease of the central nervous system which, when it begins before the age of 18, is defined as paediatric MS. Most common clinical presentations include long tract involvement, brainstem/cerebellum syndromes, optic neuritis and acute disseminated encephalomyelitis. Paediatric-onset MS typically has a more inflammatory-active course and a higher lesion burden in imaging studies, but an extensive post-relapse recovery, with a slower long-term disability progression. The first demyelinating clinical attack occurs before 10 years old in less than 1% of patients, and, in this special population, the condition has particularities in clinical presentation, differential diagnosis, diagnostic assessment, current treatment options and outcome.Clinical casesWe present the cases of four Caucasian children (2 girls) diagnosed with relapsing–remitting MS before the age of ten, with a mean age at the time of the first relapse of 7.4 ± 2.4 years. Clinical presentation included optic neuritis, myelitis, brainstem syndrome, and acute disseminated encephalomyelitis. Baseline MRI identified several lesions, frequently large and ill-defined. Two patients were included in clinical trials and two patients remain in clinical and imaging surveillance.ConclusionDiagnosis of MS before the age of 10 years is rare, but it has significant long-term physical and cognitive consequences, as well as a substantial impact on the current and future quality of life of the child and family. Early and correct diagnosis is essential. Prospective, randomized, large cohort studies are needed to assess the efficacy and safety of disease-modifying treatments in children under the age of ten

    Disentangling the phase sequence and correlated critical properties in Bi0.7La0.3FeO3 by structural studies

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    The authors would like to acknowledge Fundação para a Ciência e Tecnologia (FCT) through projects NORTE/01/0145/FEDER/028538, CERN/FIS-PAR/0005/2017, CERN/FIS-TEC/0003/2019, PTDC/FIS-MAC/29454/2017, and when appropriate cofinanced by ERDF under PT2020 Partnership Agreement: CQVR, projects UID/QUI/00616/2013 and UIDB/QUI/00616/2020; IFIMUP: Norte-070124-FEDER-000070; NECL: NORTE-01-0145-FEDER-022096, UID/NAN/50024/2019, CFisUC: UIDB/04564/2020 and UIDP/04564/2020; CICECO-Aveiro Institute of Materials: UIDB/50011/2020 and UIDP/50011/2020. M.M.G. and B.M. acknowledge the grants from the project PTDC/NAN-MAT/28538/2017.This work addresses the study of the high-temperature phase sequence of Bi0.7La0.3FeO3 by undertaking temperature-dependent high-resolution neutron powder diffraction (NPD) and Raman spectroscopy measurements. A determination of lattice parameters, phase fractions, and modulation wave vector was performed by Pawley refinement of the NPD data. The analysis revealed that Bi0.7La0.3FeO3 exhibits an incommensurate modulated orthorhombic Pn21a(00γ)000 structure at room temperature, with a weak ferromagnetic behavior, likely arising from a canted antiferromagnetic ordering. Above T1=543K, the low-temperature modulated Pn21a(00γ)000 evolves monotonically into a fractionally growing Pnma structure up to TN=663K. At 663 K, the low-temperature canted antiferromagnetic phase is suppressed concurrently with the switching of the former into a nonmodulated Pn21a structure that continues to coexist with the Pnma one, until the latter is expected to reach the 100% fraction of the sample volume at high temperatures above 733 K. The Pn21a space group is obtained from the Pnma one through the Γ4- polar distortion. Neutron diffraction and Raman spectroscopy results provide evidence for the emergence of noteworthy linear spin-phonon coupling. In this regard, magnetostructural coupling is observed below TN, revealed by the relation between the weak ferromagnetism of the canted iron spins and the FeO6 octahedra symmetric stretching mode. The correlation between magnetization and structural results from NPD provides definite evidence for the magnetic origin of the structural modulation. The analysis of the temperature-dependent magnetization and the magnetic peak intensity as well yields a critical exponent (β) value of 0.38. The lower limit of the phase coexistence temperature T1=543K, marking the emergence of the Pnma phase, is also associated with the temperature whereupon the modulation magnitude starts to decrease.Publisher PDFPeer reviewe

    Cytotoxic, antitumor and toxicological profile of Passiflora alata leaf extract

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    Passiflora alata or passion fruit is a native flowering plant from Amazon, geographically spread from Peru to Brazil. The plant has long been used in folks medicine for its pharmacological properties and is included in the Brazilian Pharmacopoeia since 1929. The aim of this study was to evaluate the potential cytotoxic and antitumor activities of Passiflora alata leaf extract (PaLE) in S180-tumor bearing mice. The percentage of cell proliferation inhibition (% CPI) and IC50 in relation to 4 tumor cell lines were determined in PC3, K-562, HepG2 and S180 cell lines using the MTT assay. PaLE showed a CPI > 75% and greater potency (IC50 < 30 µg/mL) against PC3 and S180 cell lines. PaLE showed antitumor activity in treatments intraperitoneally (36.75% and 44.99% at doses of 100 and 150 mg/kg/day, respectively). Toxicological changes were shown in the reduced body mass associated with reduced food consumption, increased spleen mass associated with histopathological increase in the white pulp of the spleen and increased number of total leukocytes with changes in the percentage relationship between lymphocytes and neutrophils. Our outcomes corroborate the conclusion that PaLE has antitumor activity in vitro and in vivo with low toxicity.This research was funded by the Coordenação Aperfeiçoamento de Pessoal de Nivel Superior (CAPES), Fundação de Ámparo à Pesquisa do Estado de Sergipe (FAPITEC) (PROCESSO: 88887.159533/2017-00 extração, encapsulação e caracterização de bioativos para o interesse biotecnologico), Banco do Nordeste (grant FUNDECI/2016.0015), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq 301964/2019-0 Chamada 06/2019, and Chamada CNPq nº 01/2019) and by the Portuguese Science and Technology Foundation (FCT) project UIDB/04469/2020 (strategic fund).info:eu-repo/semantics/publishedVersio
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