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261.
Ricardo H. Taniwaki Christoph D. Matthaei Tatima K. M. Cardoso Silvio F. B. Ferraz Luiz A. Martinelli Jeremy J. Piggott 《Biotropica》2019,51(1):18-27
Tropical streams are one of the most endangered ecosystems in the world due to the constant pressures from human activities. Among these activities, agriculture represents a land use that is crucial for human development but also a key driver of stream degradation and biodiversity decline in the tropics. Against this background, we investigated indirect effects of agriculture (alterations in stream flow and nutrient availability) and climate characteristics (water temperature) on benthic biofilm communities in tropical streams (São Paulo State, Brazil). Three first‐order streams draining catchments dominated by agricultural land use (sugarcane for bioenergy production, pasture) with some remaining riparian forest were studied for 1 year. We focused on the relationships of benthic biofilm biomass, algal biomass, diatom community, and functional structure with streamflow dynamics, nitrate concentrations, and water temperature. Our results indicate that these biological responses were mainly mediated by flow and water temperature and not by resource availability in the studied headwater streams. This result could be explained by the heavy rains and elevated runoff generation in these tropical catchments under agricultural influence, which might override the known effects of nutrient enrichment on benthic biofilm communities. Considering forecast climate and land‐use changes in tropical streams, our findings may suggest potential shifts in benthic biofilm communities, with functional consequences for aquatic food webs in these environments. Abstract in Brazilian Portuguese is available with online material. 相似文献
262.
Brunna Xavier Martins Raul Ferraz Arruda Gildeíde Aparecida Costa Hassan Jerdy Sávio Bastos de Souza Julianna Maria Santos William Rodrigues de Freitas Milton Masahiko Kanashiro Eulógio Carlos Queiroz de Carvalho Nadir Francisca SantAnna Fernanda Antunes Raul Martinez-Zaguilan Sennoune Souad Anna Lvovna Okorokova-Fa?anha Arnoldo Rocha Fa?anha 《Biochimica et Biophysica Acta (BBA)/General Subjects》2019,1863(1):1-12
Background
Metastatic tumor cells have acidic extracellular pH and differential electrochemical H+ gradients generated across their cell membranes by V-type H+-ATPases. This study shows that inhibition of the V-ATPases by the plant-derived monoterpene Myrtenal results in tumor cell death and decreased metastatic dissemination in mice.Methods
The Myrtenal anticancer toxicity was evaluated in vitro using murine (B16F0 and B16F10) and human (SkMel-5) melanoma cell lines, and in in vivo mouse metastatic dissemination model. Proton flux and extracellular acidification were directly evaluated at the surface of living cells using a non-invasive selective ion electrode approach.Results
The inhibition of V-ATPases by 100?μM Myrtenal disrupted the electrochemical H+ gradient across the cell membranes, strongly induced cell death (4–5 fold), and decreased tumor cells migration and invasion in vitro. Myrtenal (15?mg/kg) also significantly reduced metastasis induced by B16F10 in vivo, further reinforcing that V-ATPase is a molecular target to halt the progression of cancers.Conclusions
These data revealed the therapeutic potential of Myrtenal as inhibitor of melanoma progression proposing a mechanism of action by which once inhibited by this monoterpene the proton pumps fail to activate cancer-related differential electrochemical gradients and H+ fluxes across the tumor cell membranes, disrupting pH signatures inherent in tumor progression, resulting in reprogrammed cell death and metastasis inhibition.General significance
The work represents a new mechanistic strategy for contention of melanoma, the most aggressive and deadly form of cutaneous neoplasm, and highlights Myrtenal, other related monoterpenes and derivatives as promising proton pump inhibitors with high chemotherapeutic potential. 相似文献263.
Marina Shinkai Gentil Otto Jeane Gisele Francisco Beatriz Teixeira Gonsalez Lara de Almeida Calvo Eduardo Moré de Mattos Marcílio de Almeida Rafael de Andrade Moral Clarice Garcia Borges Demétrio José Luiz Stape Ricardo Ferraz de Oliveira 《Acta Physiologiae Plantarum》2017,39(9):208
Drought stress promotes biochemical and physiological alterations in plant metabolism that limit growth and yield. This study investigated the accumulation of γ-aminobutyric acid (GABA) in plant tissue, the stomatal conductance (gs) and changes in leaf anatomy in Eucalyptus following drought stress situation. In this study, eight Eucalyptus clones were evaluated under normal water supply (control) and drought stress conditions (stress). For the control treatment, plants were irrigated every day with an automated system until the soil was saturated, and for the stress treatment, drought stress was imposed by non-irrigation of plants, and pots were covered using plastic sheeting to avoid rainfall and humidity. This study has shown that: (1) all clones decreased gs with increasing vapor pressure deficit (D) in both treatments. All plastics and drought-tolerant clones (except GG) presented lower stomatal sensitivity to D under stress conditions than drought-sensitive clones; (2) GABA concentrations increased fast after drought stress, but we could not find correlation with these changes and resistance to water stress; and (3) all clones increased the number of stomata and reduced leaf thickness after water stress. The finding is that GABA is a fast stress-signaling molecule in Eucalyptus, but the response of gs to D is a best physiological variable to differentiate drought-tolerant and drought-sensitive Eucalyptus clones. 相似文献
264.
Daniele Sporck Felipe A. M. Reinoso Jorge Rencoret Ana Gutiérrez José C. del Rio André Ferraz Adriane M. F. Milagres 《Biotechnology for biofuels》2017,10(1):296
Background
New biorefinery concepts are necessary to drive industrial use of lignocellulose biomass components. Xylan recovery before enzymatic hydrolysis of the glucan component is a way to add value to the hemicellulose fraction, which can be used in papermaking, pharmaceutical, and food industries. Hemicellulose removal can also facilitate subsequent cellulolytic glucan hydrolysis.Results
Sugarcane bagasse was pretreated with an alkaline-sulfite chemithermomechanical process to facilitate subsequent extraction of xylan by enzymatic or alkaline procedures. Alkaline extraction methods yielded 53% (w/w) xylan recovery. The enzymatic approach provided a limited yield of 22% (w/w) but produced the xylan with the lowest contamination with lignin and glucan components. All extracted xylans presented arabinosyl side groups and absence of acetylation. 2D-NMR data suggested the presence of O-methyl-glucuronic acid and p-coumarates only in enzymatically extracted xylan. Xylans isolated using the enzymatic approach resulted in products with molecular weights (Mw) lower than 6 kDa. Higher Mw values were detected in the alkali-isolated xylans. Alkaline extraction of xylan provided a glucan-enriched solid readily hydrolysable with low cellulase loads, generating hydrolysates with a high glucose/xylose ratio.Conclusions
Hemicellulose removal before enzymatic hydrolysis of the cellulosic fraction proved to be an efficient manner to add value to sugarcane bagasse biorefining. Xylans with varied yield, purity, and structure can be obtained according to the extraction method. Enzymatic extraction procedures produce high-purity xylans at low yield, whereas alkaline extraction methods provided higher xylan yields with more lignin and glucan contamination. When xylan extraction is performed with alkaline methods, the residual glucan-enriched solid seems suitable for glucose production employing low cellulase loadings.265.
Edmundo Ferraz Nonato Tânia A. S. Brito Paulo Cesar De Paiva Monica A. V. Petti Thais N. Corbisier 《Polar Biology》2000,23(8):580-588
The benthic megafauna from the soft bottoms of the shallow coastal zone of Martel Inlet (Admiralty Bay, King George Island,
South Shetland Islands, Antarctica) was studied during three austral summers (1989/1990, 1990/1991 and 1994/1995) in relation
to the bathymetric features. Surveying and sampling, based on specimen counting and underwater observations, were undertaken
by scuba-diving at depths down to 25 m. The depth zonation appears to be influenced by the nature of the substrate and especially
by the action of the ice. The multiple action of ice flows prevents the occurrence of sessile forms in the shallower areas,
where a low-diversity community, dominated by motile animals, was found. In the area around 18 m in depth, the action of icebergs
generated faunistic and sedimentary patches of impacted and non-impacted areas. The more stable conditions prevailing below
depths of 20–25 m allowed the establishment of a more diversified epifauna, including many sessile forms. The interannual
differences observed in the densities of the mobile isopod Serolis polita may be associated with the summer period when the sampling was undertaken.
Accepted: 1 March 2000 相似文献
266.
Julian Stocker Ana Paula Morel Micaele Wolfarth Johnny Ferraz Dias Liana Appel Boufleur Niekraszewicz Cristina V. Cademartori Fernanda R. da Silva 《Genetics and molecular biology》2022,45(2)
It is essential to determine the basal pattern of different biomarkers for future evaluation of animal health and biomonitoring studies. Due to their great displacement capacity and to being at the top of their food chains, birds of prey are suitable for monitoring purposes. Furthermore, some birds of prey are adapted to using resources in urban places, providing information about this environment. Thus, this study determined the basal frequency of micronuclei and other nuclear alterations in peripheral blood erythrocytes of Falco peregrinus. Hematological and inorganic elements analysis were also performed. For this purpose, 13 individuals (7 females and 6 males) were sampled in private breeding grounds. Micronucleus, nuclear buds, nucleoplasmic bridges, notched nuclei, binucleated cells and nuclear tails were quantified. Inorganic elements detected included the macro-elements Ca, P, Mg, Na, Cl, S and K as well as the micro-elements Fe, Al and Zn. Our study found similar values compared to previous studies determining the reference ranges of hematologic parameters in falcons. The only different value was observed in the relative number of monocytes. Thus, this study is the first approach to obtaining reference values of cytogenetic damage in this species and could be useful for future comparisons in biomonitoring studies. Keywords: Biological monitoring, basal DNA damage, falcon, reference value, hematologyIn recent years, different organisms have provided information about environmental quality (Parmar et al., 2016). Birds of prey due to their great displacement capacity and to being at the top of the food chains are suited for monitoring purposes (Lodenius and Solonen, 2013). Top bird predators have been evaluated regarding exposure to pesticide, metal and other chemical substances (Lodenius and Solonen, 2013; de Wit et al., 2019; Aver et al., 2020; Frixione and Rodríguez-Estrella, 2020). In biomonitoring studies, it is possible to evaluate biomarkers at the molecular, cellular, morphological and physiological levels in different species. Among the available bioassays, there are several that are more invasive or less invasive to animals (Valdes, 2010). A technique that estimates the exposure level in DNA without having to sacrifice the organism exposed is the Erythrocyte Nuclear Abnormalities (ENA) assay. The ENA assay is considered a proper tool for detecting the DNA damage because its analysis includes micronuclei and the other nuclear alterations analyses (Gomes et al., 2015). Most studies about genotoxicity in birds include only micronuclei in analysis, excluding the other nuclear variations, which may be more frequent than micronuclei. Nuclei with smaller or larger evaginations, nuclei with vacuoles and nuclei with a deep slit are alterations that can also be observed (Carrasco et al., 1990; Quero et al., 2016; de Souza et al., 2017; de Faria et al., 2018; Silveira et al., 2022).Some birds of prey, such as Falco peregrinus, have adapted to using resources in urban areas. According to Pollack et al. (2017) these species provide information, especially about the widespread consequences of urbanization, giving an insight into its influence on animal behavior and physiology, as well as guiding investigations in humans. The aim of this study was to determine the frequency of micronuclei and other nuclear alterations in peripheral blood erythrocytes of Falco peregrinus, as a first approach to obtain reference values of cytogenetic damage in this species. Furthermore, knowledge was obtained regarding other physiological parameters, such as hematological analysis and the quantification of inorganic elements.All birds used in this study belong to Criatório Hayabusa - Consultoria Ambiental Ltda., a wildlife center and commercial breeder located in São Francisco de Paula (Rio Grande do Sul, Brazil). The area has approximately 48 ha and is considered to be in an excellent state of conservation, distant from urban areas and areas where crops are cultivated. The individuals are housed in outdoor aviary cages (4 m (width) x 4 m (height) x 4 m (length)) containing a couple of birds each. The birds had been captive for at least four years and were fed daily with Coturnix coturnix and water ad libitum. The sex of the birds was determined through external sexual size dimorphism, wherein the male can carry up to 50% less loads than the female (Mills et al., 2019). In addition, the bird’s age (juvenile/adult) was defined according to information on a metal ring.The procedures involving animals were conducted in compliance with the guidelines approved by the Committee on Ethics in the Use of Animals of the Universidade La Salle (CEUA-UNILASALLE, number 003/2017), and authorized by the Ministry of the Environment (MMA) through the Sistema de Autorização e Informação da Biodiversidade (SISBIO) for scientific activities (number 59921-1).Blood samples of 13 individuals, collected by the center’s veterinarian, were drawn from the ulnar vein of the wing using heparinised syringes. The samples were immediately smeared onto clean glass slides, where two slides were prepared per individual. The slides were sent to the laboratory. Remaining blood samples were also transported to the laboratories at below 8 ºC for the analysis of hematological and inorganic elements. The animals were identified as to sex and age (juvenile/adult). All the birds sampled were apparently healthy, without any signs of illness.In the laboratory, the slides were prepared according to Grisolia and Cordeiro (2000). At least 2,000 erythrocytes for each animal were scored using bright-field optical microscopy at a magnification of ×200-1000. Coded slides were blind-scored by a single observer. The presence of ENA was evaluated according to procedures by Carrasco et al. (1990) and Quero et al. (2016), using mature erythrocytes to estimate the frequency of the following nuclear lesions: (i) micronuclei (MN); (ii) nuclear buds (NBud); (iii) binucleated cell (BN); (iv) nuclear tails (NT); (v) nucleoplasmic (NB); and (vi) Notched (NO).The content of inorganic elements in the blood samples was analyzed by particle-induced X-ray emission (PIXE) (Johansson et al., 1995). As the PIXE system requires the use of solid samples, the blood samples were dried at 60 °C. Once dried, the samples were homogenized and pressed into 2 mm thick pellets before being placed in the target holder inside the reaction chamber (pressure about 10-5 mbar). A 3 MV Tandetron accelerator provided a 2.0 MeV proton beam with an average current of 3 nA at the target. The X-rays produced in the samples were detected by a Si(Li) detector with an energy resolution of ca. 150 eV at 5.9 keV. The spectra were analyzed with the GUPIX software package and the results were expressed in mg/g (Campbell et al., 2000). The same sample was evaluated in three independent analyses in order to obtain mean and standard deviation.The hematological evaluation was carried out in a commercial laboratory (BLUT’S Centro de Diagnóstico, Produtos e Serviços Veterinários, Porto Alegre-RS, Brazil) according to standard methods. Together with the results of the present study, information about other studies were taken as reference to interpret hematologic parameters.The normality of the variables was evaluated using the Kolmogorov-Smirnov test. To compare the parameters of the study population, Studentt-, and Mann-Whitney U non-parametric tests were used. The critical level for rejection of the null hypothesis was considered to be P < 0.05.The interspecific variations in the spontaneous frequencies of nuclear alterations are probably related to the intrinsic individual factors associated with ingestion, accumulation, metabolism and excretion of the xenobiotics to which the organism is exposed daily. Furthermore, the correct functioning of the DNA repair also could be involved in this interspecific response to DNA damage (Jha, 2004). Information on 13 animals sampled is presented in Female (n=7) Male (n=6) Total (n=13) Micronucleus 1.29 ± 1.50 2.00 ± 1.26 1.62 ± 1.39 Nuclear buds 3.14 ± 2.34 1.5 ± 1.52 2.38 ± 2.10 Nucleoplasmic bridges 0.43 ± 0.53 0 0.23 ± 0.44 Nuclear tails 1.14 ± 1.07 0.5 ± 0.55 0.85 ± 0.90 Notched nuclei 0.14 ± 0.38 0.33 ± 0.82 0.23 ± 0.60 Binucleated cells 1.29 ± 1.38 1.17 ± 1.94 1.23 ± 1.59