Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 30
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Plants (Basel) ; 12(20)2023 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-37896085

RESUMO

Anthropogenic behaviors are causing the severe build-up of heavy metal (HM) pollutants in the environment, particularly in soils. Amongst a diversity of remediation technologies, phytoremediation is an environmentally friendly technology that, when coupling tolerant plants to selected rhizospheric microorganisms, can greatly stimulate HM decontamination of soils. Maize (Zea mays) is a plant with the reported capacity for HM exclusion from contaminated soil but also has energetic importance. In this study, Zea mays was coupled with Rhizophagus irregularis, an arbuscular mycorrhizal fungus (AMF), and Cupriavidus sp. strain 1C2, a plant growth-promoting rhizobacteria (PGPR), as a remediation approach to remove Cd and Zn from an industrial contaminated soil (1.2 mg Cd kg-1 and 599 mg Zn kg-1) and generate plant biomass, by contrast to the conservative development of the plant in an agricultural (with no metal pollution) soil. Biomass production and metal accumulation by Z. mays were monitored, and an increase in plant yield of ca. 9% was observed after development in the contaminated soil compared to the soil without metal contamination, while the plants removed ca. 0.77% and 0.13% of the Cd and Zn initially present in the soil. The resulting biomass (roots, stems, and cobs) was used for biogas generation in several biomethane (BMP) assays to evaluate the potential end purpose of the phytoremediation-resulting biomass. It was perceptible that the HMs existent in the industrial soil did not hinder the anaerobic biodegradation of the biomass, being registered biomethane production yields of ca. 183 and 178 mL of CH4 g-1 VS of the complete plant grown in non-contaminated and contaminated soils, respectively. The generation of biomethane from HM-polluted soils' phytoremediation-derived maize biomass represents thus a promising possibility to be a counterpart to biogas production in an increasingly challenging status of renewable energy necessities.

2.
Biomedicines ; 9(8)2021 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-34440085

RESUMO

Alzheimer's disease (AD) is characterized by the accumulation of extracellular plaques composed by amyloid-ß (Aß) and intracellular neurofibrillary tangles of hyperphosphorylated tau. AD-related neurodegenerative mechanisms involve early changes of mitochondria-associated endoplasmic reticulum (ER) membranes (MAMs) and impairment of cellular events modulated by these subcellular domains. In this study, we characterized the structural and functional alterations at MAM, mitochondria, and ER/microsomes in a mouse neuroblastoma cell line (N2A) overexpressing the human amyloid precursor protein (APP) with the familial Swedish mutation (APPswe). Proteins levels were determined by Western blot, ER-mitochondria contacts were quantified by transmission electron microscopy, and Ca2+ homeostasis and mitochondria function were analyzed using fluorescent probes and Seahorse assays. In this in vitro AD model, we found APP accumulated in MAM and mitochondria, and altered levels of proteins implicated in ER-mitochondria tethering, Ca2+ signaling, mitochondrial dynamics, biogenesis and protein import, as well as in the stress response. Moreover, we observed a decreased number of close ER-mitochondria contacts, activation of the ER unfolded protein response, reduced Ca2+ transfer from ER to mitochondria, and impaired mitochondrial function. Together, these results demonstrate that several subcellular alterations occur in AD-like neuronal cells, which supports that the defective ER-mitochondria crosstalk is an important player in AD physiopathology.

3.
Environ Pollut ; 287: 117553, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34175520

RESUMO

DNA damage and changes in proteome response can occur as a consequence of UV light exposure. The emerging light-emitting diodes (LEDs) can be acquired with different wavelengths. In this study, LEDs that emit at 255 nm and 265 nm were selected to test the DNA damage and proteome response after inactivation of A. fumigatus, A. niger and A. terreus spiked into filtered surface water. Additionally, photoreactivation and dark repair studies were performed to evaluate the potential ability of the spores to recover after UV exposure. Results showed that both LEDs were able to induce the formation of cyclobutane pyrimidine dimers in A. fumigatus and A. terreus whereas, for A. niger, the formation of cyclobutane pyrimidine dimers was only detected when the LEDs that induced inactivation (that emit at 265 nm) were used. Proteome response showed that UV radiation treatment triggered different types of stress response, mainly concerning the protection from oxidative stress by A. fumigatus and A. terreus. Photoreactivation was detected for all the species except A. niger and, no dark repair was observed.


Assuntos
Desinfecção , Proteoma , Aspergillus , Dano ao DNA , Raios Ultravioleta , Água
4.
Biomedicines ; 9(5)2021 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-34066918

RESUMO

This study aims to evaluate whether mitochondrial changes occur in the early stages of bipolar disorder (BD). Using fibroblasts derived from BD patients and matched controls, the levels of proteins involved in mitochondrial biogenesis and dynamics (fission and fusion) were evaluated by Western Blot analysis. Mitochondrial membrane potential (MMP) was studied using the fluorescent probe TMRE. Mitochondrial morphology was analyzed with the probe Mitotracker Green and mitophagy was evaluated by quantifying the co-localization of HSP60 (mitochondria marker) and LC3B (autophagosome marker) by immunofluorescence. Furthermore, the activity of the mitochondrial respiratory chain and the glycolytic capacity of controls and BD patients-derived cells were also studied using the Seahorse technology. BD patient-derived fibroblasts exhibit fragmented mitochondria concomitantly with changes in mitochondrial dynamics and biogenesis in comparison with controls. Moreover, a decrease in the MMP and increased mitophagy was observed in fibroblasts obtained from BD patients when compared with control cells. Impaired energetic metabolism due to inhibition of the mitochondrial electron transport chain (ETC) and subsequent ATP depletion, associated with glycolysis stimulation, was also a feature of BD fibroblasts. Overall, these results support the fact that mitochondrial disturbance is an early event implicated in BD pathophysiology that might trigger neuronal changes and modification of brain circuitry.

5.
Sci Rep ; 10(1): 15688, 2020 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-32973337

RESUMO

Vitis vinifera, one of the most cultivated fruit crops, is susceptible to several diseases particularly caused by fungus and oomycete pathogens. In contrast, other Vitis species (American, Asian) display different degrees of tolerance/resistance to these pathogens, being widely used in breeding programs to introgress resistance traits in elite V. vinifera cultivars. Secondary metabolites are important players in plant defence responses. Therefore, the characterization of the metabolic profiles associated with disease resistance and susceptibility traits in grapevine is a promising approach to identify trait-related biomarkers. In this work, the leaf metabolic composition of eleven Vitis genotypes was analysed using an untargeted metabolomics approach. A total of 190 putative metabolites were found to discriminate resistant/partial resistant from susceptible genotypes. The biological relevance of discriminative compounds was assessed by pathway analysis. Several compounds were selected as promising biomarkers and the expression of genes coding for enzymes associated with their metabolic pathways was analysed. Reference genes for these grapevine genotypes were established for normalisation of candidate gene expression. The leucoanthocyanidin reductase 2 gene (LAR2) presented a significant increase of expression in susceptible genotypes, in accordance with catechin accumulation in this analysis group. Up to our knowledge this is the first time that metabolic constitutive biomarkers are proposed, opening new insights into plant selection on breeding programs.


Assuntos
Suscetibilidade a Doenças , Regulação da Expressão Gênica de Plantas , Expressão Gênica , Micoses/genética , Oomicetos , Doenças das Plantas/microbiologia , Vitis/microbiologia , Biomarcadores , Metabolômica , Micoses/metabolismo , Doenças das Plantas/genética
6.
BMJ Open ; 10(8): e036413, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32788187

RESUMO

INTRODUCTION: Cataract is the leading cause of blindness globally and a major cause of vision impairment. Cataract surgery is an efficacious intervention that usually restores vision. Although it is one of the most commonly conducted surgical interventions worldwide, good quality services (from being detected with operable cataract to undergoing surgery and receiving postoperative care) are not universally accessible. Poor quality understandably reduces the willingness of people with operable cataract to undergo surgery. Therefore, it is critical to improve the quality of care to subsequently reduce vision loss from cataract. This scoping review aims to summarise the nature and extent of the published literature on interventions to improve the quality of services for primary age-related cataract globally. METHODS AND ANALYSIS: We will search MEDLINE, Embase and Global Health for peer-reviewed manuscripts published since 1990, with no language, geographic or study design restrictions. To define quality, we have used the elements adopted by the WHO-effectiveness, safety, people-centredness, timeliness, equity, integration and efficiency-to which we have added the element of planetary health. We will exclude studies focused on the technical aspects of the surgical procedure and studies that only involve children (<18 years). Two reviewers will screen all titles/abstracts independently, followed by a full-text review of potentially relevant articles. For included articles, data regarding publication characteristics, study details and quality-related outcomes will be extracted by two reviewers independently. Results will be synthesised narratively and presented visually using a spider chart. ETHICS AND DISSEMINATION: Ethical approval was not sought, as our review will only include published and publicly accessible information. We will publish our findings in an open-access peer-reviewed journal and develop an accessible summary of the results for website posting. A summary of the results will be included in the ongoing Lancet Global Health Commission on Global Eye Health. REGISTRATION DETAILS: Open Science Framework (https://osf.io/8gktz).


Assuntos
Extração de Catarata , Catarata , Catarata/terapia , Criança , Atenção à Saúde , Saúde Global , Humanos , Literatura de Revisão como Assunto , Visão Ocular
7.
Chem Res Toxicol ; 33(4): 915-932, 2020 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-32138518

RESUMO

Glucan (from Alcaligenes faecalis) is a polymer composed of ß-1,3-linked glucose residues, and it has been addressed in different medical fields, namely in nanotechnology, as a vaccine or a drug delivery system. However, due to their small size, nanomaterials may present new risks and uncertainties. Thus, this work aims to describe the production of glucan nanoparticles (NPs) with two different sizes, and to evaluate the influence of the NPs size on immunotoxicity. Results showed that, immediately after production, glucan NPs presented average sizes of 129.7 ± 2.5 and 355.4 ± 41.0 nm. Glucan NPs of 130 nm presented greater ability to decrease human peripheral blood mononuclear cells and macrophage viability and to induce reactive oxygen species production than glucan NPs of 355 nm. Both NP sizes caused hemolysis and induced a higher metabolic activity in lymphocytes, although the concentration required to observe such effect was lower for the 130 nm glucan NPs. Regarding pro-inflammatory cytokines, only the larger glucan NPs (355 nm) were able to induce the secretion of IL-6 and TNF-α, probably due to their recognition by dectin-1. This higher immunomodulatory effect of the larger NPs was also observed in its ability to stimulate the production of nitric oxide (NO) and IL-1ß. On the contrary, a small amount of Glu 130 NPs inhibited NO production. In conclusion, on the safe-by-design of glucan NPs, the size of the particles should be an important critical quality attribute to guarantee the safety and effectiveness of the nanomedicine.


Assuntos
Morte Celular/efeitos dos fármacos , Glucanos/toxicidade , Leucócitos Mononucleares/efeitos dos fármacos , Nanopartículas/química , Nanopartículas/toxicidade , Alcaligenes/química , Sobrevivência Celular/efeitos dos fármacos , Glucanos/síntese química , Glucanos/química , Humanos , Leucócitos Mononucleares/imunologia , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Tamanho da Partícula , Espécies Reativas de Oxigênio/metabolismo
8.
J Environ Manage ; 257: 109982, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31868642

RESUMO

Salt-affected soils are a major problem worldwide for crop production. Bioinocula such as plant growth-promoting bacteria (PGPB) and arbuscular mycorrhizal fungi (AMF) can help plants to thrive in these areas but interactions between them and with soil conditions can modulate the effects on their host. To test potential synergistic effects of bioinoculants with intrinsically different functional relationships with their host in buffering the effect of saline stress, maize plants were grown under increasing soil salinity (0-5 g NaCl kg--1 soil) and inoculated with two PGPB strains (Pseudomonas reactans EDP28, and Pantoea alli ZS 3-6), one AMF (Rhizoglomus irregulare), and with the combination of both. We then modelled biomass, ion and nutrient content in maize plants in response to increasing salt concentration and microbial inoculant treatments using generalized linear models. The impacts of the different treatments on the rhizosphere bacterial communities were also analyzed. Microbial inoculants tended to mitigate ion imbalances in plants across the gradient of NaCl, promoting maize growth and nutritional status. These effects were mostly prominent in the treatments comprising the dual inoculation (AMF and PGPB), occurring throughout the gradient of salinity in the soil. The composition of bacterial communities of the soil was not affected by microbial treatments and were mainly driven by salt exposure. The tested bioinocula are most efficient for maize growth and health when co-inoculated, increasing the content of K+ accompanied by an effective decrease of Na+ in plant tissues. Moreover, synergistic effects potentially contribute to expanding crop production to otherwise unproductive soils. Results suggest that the combination of AMF and PGPB leads to interactions that may have a potential role in alleviating the stress and improve crop productivity in salt-affected soils.


Assuntos
Micorrizas , Bactérias , Raízes de Plantas , Salinidade , Solo , Microbiologia do Solo , Zea mays
10.
J Med Chem ; 60(2): 568-579, 2017 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-28098449

RESUMO

Inhibiting glucose reabsorption by sodium glucose co-transporter proteins (SGLTs) in the kidneys is a relatively new strategy for treating type 2 diabetes. Selective inhibition of SGLT2 over SGLT1 is critical for minimizing adverse side effects associated with SGLT1 inhibition. A library of C-glucosyl dihydrochalcones and their dihydrochalcone and chalcone precursors was synthesized and tested as SGLT1/SGLT2 inhibitors using a cell-based fluorescence assay of glucose uptake. The most potent inhibitors of SGLT2 (IC50 = 9-23 nM) were considerably weaker inhibitors of SGLT1 (IC50 = 10-19 µM). They showed no effect on the sodium independent GLUT family of glucose transporters, and the most potent ones were not acutely toxic to cultured cells. The interaction of a C-glucosyl dihydrochalcone with a POPC membrane was modeled computationally, providing evidence that it is not a pan-assay interference compound. These results point toward the discovery of structures that are potent and highly selective inhibitors of SGLT2.


Assuntos
Chalconas/farmacologia , Diabetes Mellitus Tipo 2/tratamento farmacológico , Glucosídeos/farmacologia , Inibidores do Transportador 2 de Sódio-Glicose , Chalconas/síntese química , Chalconas/toxicidade , Glucosídeos/síntese química , Glucosídeos/toxicidade , Células HEK293 , Humanos , Membranas Artificiais , Simulação de Acoplamento Molecular , Fosfatidilcolinas/química , Transportador 1 de Glucose-Sódio/antagonistas & inibidores , Transportador 2 de Glucose-Sódio
11.
Eur J Cancer Prev ; 26(2): 135-143, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-26895574

RESUMO

The objective was to quantify thyroid cancer incidence and mortality trends in Portugal. The number of thyroid cancer cases and incidence rates were retrieved from the Regional Cancer Registries for the period 1989-2011. The number of deaths and mortality rates were obtained from the WHO cancer mortality database (1988-2003 and 2007-2012) and Statistics Portugal (2004-2006; 1988-2012 by region). Joinpoint regression of the standardized incidence and mortality rates was performed. A significant, rapid and continued increase in incidence was observed for both sexes in each of the Regional Cancer Registries, with annual per cent changes (APCs) ranging between 2 and 9. Incidence in Portuguese women is higher than estimates for the world and Europe. Mortality decreased for women (APC: -1.5), with the greatest decrease in the North, and increased marginally for men (APC: +0.2), with a greater increase in the South. The significant increases in incidence in Portugal are predominantly because of the increase in incidence among women from the North. These trends, combined with an overall low mortality and high 5-year relative survival, raise concerns on the extent to which overdiagnosis may be taking place. Further research is needed, quantifying the importance of the most likely determinants of these trends as well as the extent and potentially deleterious effects of overdiagnosis and overtreatment in the Portuguese setting.


Assuntos
Neoplasias da Glândula Tireoide/diagnóstico , Neoplasias da Glândula Tireoide/mortalidade , Feminino , Humanos , Incidência , Masculino , Mortalidade/tendências , Portugal/epidemiologia
12.
Environ Sci Pollut Res Int ; 23(7): 6940-50, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26676544

RESUMO

The use of heavy metals (HM) contaminated soils to grow energy crops can diminish the negative impact of HM in the environment improving land restoration. The effect of two PGPR (B1--Chryseobacterium humi ECP37(T) and B2--Pseudomonas reactans EDP28) and an AMF (F--Rhizophagus irregularis) on growth, Cd and Zn accumulation, and nutritional status of energy maize plants grown in a soil collected from an area adjacent to a Portuguese mine was assessed in a greenhouse experiment. Both bacterial strains, especially when co-inoculated with the AMF, acted as plant growth-promoting inoculants, increasing root and shoot biomass as well as shoot elongation. Cadmium was not detected in the maize tissues and a decrease in Zn accumulation was observed for all microbial treatments in aboveground and belowground tissues--with inoculation of maize with AMF and strain B2 leading to maximum reductions in Zn shoot and root accumulation of up to 48 and 43%, respectively. Although microbial single inoculation generally did not increase N and P levels in maize plants, co-inoculation of the PGPR and the AMF improved substantially P accumulation in roots. The DGGE analysis of the bacterial rhizosphere community showed that the samples inoculated with the AMF clustered apart of those without the AMF and the Shannon-Wiener Index (H') increased over the course of the experiment when both inoculants were present. This work shows the benefits of combined inoculation of AMF and PGPR for the growth energy maize in metal contaminated soils and their potential for the application in phytomanagement strategies.


Assuntos
Mineração , Micorrizas/fisiologia , Rizosfera , Microbiologia do Solo , Poluentes do Solo/análise , Zea mays/crescimento & desenvolvimento , Biodegradação Ambiental , Biomassa , Cádmio , Glomeromycota , Metais Pesados/análise , Desenvolvimento Vegetal , Raízes de Plantas , Rhizobium , Solo , Zea mays/química
13.
Environ Sci Pollut Res Int ; 21(16): 9742-53, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24764002

RESUMO

Zea mays (L.) is a crop widely cultivated throughout the world and can be considered suitable for phytomanagement due to its metal resistance and energetic value. In this study, the effect of two plant growth-promoting rhizobacteria, Ralstonia eutropha and Chryseobacterium humi, on growth and metal uptake of Z. mays plants in soils contaminated with up to 30 mg Cd kg(-1) was evaluated. Bacterial inoculation increased plant biomass up to 63% and led to a decrease of up to 81% in Cd shoot levels (4-88 mg Cd kg(-1)) and to an increase of up to 186% in accumulation in the roots (52-134 mg Cd kg(-1)). The rhizosphere community structure changed throughout the experiment and varied with different levels of Cd soil contamination, as revealed by molecular biology techniques. Z. mays plants inoculated with either of the tested strains may have potential application in a strategy of soil remediation, in particular short-term phytostabilization, coupled with biomass production for energy purposes.


Assuntos
Cádmio/isolamento & purificação , Rhizobium/metabolismo , Poluentes do Solo/isolamento & purificação , Zea mays/crescimento & desenvolvimento , Biodegradação Ambiental , Cádmio/metabolismo , Poluição Ambiental , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/microbiologia , Rizosfera , Solo , Microbiologia do Solo , Poluentes do Solo/metabolismo , Zea mays/efeitos dos fármacos , Zea mays/microbiologia
14.
J Environ Manage ; 128: 877-82, 2013 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-23880431

RESUMO

The main aim of this study was to investigate the performance of an aerobic granular sludge sequencing batch reactor (AGS-SBR) receiving water streams supplied with different loads of Zn(2+) (50 and 100 mg L(-1)) during an operation of 866 cycles (ca. 109 days). When the metal was not fed, chemical oxygen demand (COD), PO4(3-) and NH4(+) were efficiently removed, with efficiencies of 56, 23 and 72% respectively. DGGE profiles showed that Zn(2+) supply negatively affected the bacterial diversity and community structure of the granules. Consequently, the shock loadings with Zn(2+), particularly at the higher levels (100 mg L(-1)), affected the nutrient removal in the AGS-SBR, although the reactor still generally complied with admissible legal values concerning organic matter, nitrogen and Zn. Simultaneous removal of PO4(3-) and TSS in such conditions needs further refining but the application of aerobic granular SBR in the treatment of Zn(2+) contaminated wastewaters seems viable.


Assuntos
Reatores Biológicos/microbiologia , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/química , Zinco/metabolismo , Compostos de Amônio/química , Compostos de Amônio/metabolismo , Bactérias/efeitos dos fármacos , Bactérias/genética , Biodiversidade , Análise da Demanda Biológica de Oxigênio , Fosfatos/química , Fosfatos/metabolismo , RNA Ribossômico 16S , Eliminação de Resíduos Líquidos/instrumentação , Zinco/isolamento & purificação , Zinco/farmacologia
15.
Chemosphere ; 92(1): 74-83, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23582407

RESUMO

Plant growth promoting bacteria (PGPR) may help reducing the toxicity of heavy metals to plants in polluted environments. In this work the effects of inoculating metal resistant and plant growth promoting bacterial strains on the growth of Helianthus annuus grown in Zn and Cd spiked soils were assessed. The PGPR strains Ralstonia eutropha (B1) and Chrysiobacterium humi (B2) reduced losses of weight in metal exposed plants and induced changes in metal bioaccumulation and bioconcentration - with strain B2 decreasing up to 67% Zn accumulation and by 20% Zn bioconcentration factor (BCF) in the shoots, up to 64% Zn uptake and 38% Zn BCF in the roots, and up to 27% Cd uptake and 27% Cd BCF in plant roots. The impact of inoculation on the bacterial communities in the rhizosphere of the plant was also assessed. Bacterial community diversity decreased with increasing levels of metal contamination in the soil, but in rhizosphere soil of plants inoculated with the PGPR strains, a higher bacterial diversity was kept throughout the experimental period. Inoculation of sunflower, particularly with C. humi (B2), appears to be an effective way of enhancing the short term stabilization potential of the plant in metal contaminated land, lowering losses in plant biomass and decreasing aboveground tissue contamination.


Assuntos
Cádmio/metabolismo , Helianthus/metabolismo , Poluentes do Solo/metabolismo , Zinco/metabolismo , Biodegradação Ambiental , Biomassa , Cádmio/química , Cupriavidus necator/isolamento & purificação , Cupriavidus necator/metabolismo , Helianthus/química , Helianthus/crescimento & desenvolvimento , Raízes de Plantas/química , Raízes de Plantas/metabolismo , Brotos de Planta/química , Brotos de Planta/metabolismo , Rizosfera , Microbiologia do Solo , Poluentes do Solo/química , Zinco/química
16.
Sci Total Environ ; 414: 63-7, 2012 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-22115613

RESUMO

Cadmium is one of the most toxic heavy metals and its accumulation in the upper layers of forest soils affects plants, microorganisms and their interactions. Adequate strategies for the reforestation of metal contaminated sites are of vital importance. The aim of this work was to evaluate the response of Pinus pinaster seedlings to Cd exposure and to assess the effect of inoculation with two selected ectomycorrhizal fungi, Suillus bovinus and Rhizopogon roseolus on that response. Seedlings were exposed to soil contaminated at 15 and 30 mg Cd kg(-1). Shoot biomass of P. pinaster decreased ca. 36% when exposed to 15 mg Cd kg(-1). Overall, colonization by S. bovinus significantly enhanced shoot development up to 30% in contaminated soil while colonization by R. roseolus produced no significant effect at both Cd concentrations tested and significantly increased the level of Cd in the shoots at both Cd concentrations. Metal accumulation in the shoots and roots of non-inoculated and S. bovinus-inoculated seedlings increased at the higher Cd levels whereas R. roseolus-inoculated seedlings were not sensitive to Cd variation in the soil. The results from our research show that inoculation with ECM fungi has a significant impact on metal uptake and development of P. pinaster seedlings; the differential response induced by the two tested species highlights the importance of selecting the appropriate strains for nursery inoculation, and, as such, this biological tool ought to be considered in reforestation processes of heavy metal contaminated areas by woody species.


Assuntos
Basidiomycota/fisiologia , Cádmio/toxicidade , Micorrizas/fisiologia , Pinus/efeitos dos fármacos , Pinus/microbiologia , Poluentes do Solo/toxicidade , Simbiose , Análise de Variância , Biomassa , Cádmio/farmacocinética , Recuperação e Remediação Ambiental/métodos , Pinus/crescimento & desenvolvimento , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Plântula/microbiologia , Poluentes do Solo/farmacocinética
17.
Rev Port Cardiol ; 30(10): 763-9, 2011 Oct.
Artigo em Português | MEDLINE | ID: mdl-22118127

RESUMO

INTRODUCTION: LDLr-/- mice are spontaneously hyperlipidemic and resistant to the development of neointimal lesions. OBJECTIVES: This study aimed to determine the factor that prevents the inflammatory process and neointimal lesions and insulin resistance in LDLr-/- mice. METHODS: Three groups of 3-month-old male mice were used: wild-type mice (WT group); LDLr-/- mice fed a standard diet (S group); and LDLr-/- mice fed a high-fat diet (HF group). After 15 days, blood was collected for analysis of plasma lipids, glucose and insulin. The HOMA index was calculated to determine insulin resistance. The heart and aorta were removed for histological study. Histological sections of the heart were processed immunohistochemically with anti-CD40L antibodies to evaluate the inflammatory process. Histological sections of the aorta were stained with hematoxylin/eosin and picrosirius red to assess morphological and morphometric alterations. RESULTS: The S mice were resistant to the inflammatory process, as shown by low immunoreactivity to CD40L, with high plasma HDL levels, and did not develop insulin resistance, even with moderate hyperlipidemia compared to WT. The HF mice showed severe hyperlipidemia, increased cardiac immunoreactivity to CD40L, pronounced morphological changes in the aortic wall and insulin resistance, associated with a decrease in plasma HDL levels, compared to S. This severe hyperlipidemia in the HF mice can be considered the major metabolic factor inducing oxidative stress in the cardiovascular system, increasing the lipid peroxidation of HDL and hence its removal by the liver, with consequent lowering of plasma HDL levels. CONCLUSION: High HDL plasma levels are a protective factor against the development of cardiovascular inflammation and insulin resistance in LDLr-/- mice, preventing the development of neointimal lesions.


Assuntos
Hiperlipidemias/sangue , Inflamação/sangue , Lipoproteínas HDL/fisiologia , Animais , Sistema Cardiovascular/patologia , Humanos , Hiperlipidemias/complicações , Inflamação/etiologia , Inflamação/prevenção & controle , Lipoproteínas HDL/sangue , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neointima/patologia
18.
Int Microbiol ; 14(3): 155-62, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22101413

RESUMO

Oenococcus oeni is an alcohol-tolerant, acidophilic lactic acid bacterium that plays an important role in the elaboration of wine. It is often added as a starter culture to carry out malolactic conversion. Given the economic importance of this reaction, the taxonomic structure of this species has been studied in detail. In the present work, phenotypic and molecular approaches were used to identify 121 lactic acid bacteria strains isolated from the wines of three winemaking regions of Portugal. The strains were differentiated at the genomic level by M13-PCR fingerprinting. Twenty-seven genomic clusters represented by two or more isolates and 21 single-member clusters, based on an 85% similarity level, were recognized by hierarchic numerical analysis. M13-PCR fingerprinting patterns revealed a high level of intraspecific genomic diversity in O. oeni. Moreover, this diversity could be partitioned according to the geographical origin of the isolates. Thus, M13-PCR fingerprint analysis may be an appropriate methodology to study the O. oeni ecology of wine during malolactic fermentation as well as to trace new malolactic starter cultures and evaluate their dominance over the native microbiota.


Assuntos
DNA Bacteriano/genética , Microbiologia de Alimentos , Genoma Bacteriano , Genômica , Oenococcus/genética , Vinho/microbiologia , Impressões Digitais de DNA , DNA Bacteriano/classificação , Fermentação , Variação Genética , Família Multigênica , Oenococcus/classificação , Oenococcus/enzimologia , Oenococcus/isolamento & purificação , Filogenia , Filogeografia , Reação em Cadeia da Polimerase , Portugal
19.
Int. microbiol ; 14(3): 155-162, sept. 2011. ilus, tab
Artigo em Inglês | IBECS | ID: ibc-98738

RESUMO

Oenococcus oeni is an alcohol-tolerant, acidophilic lactic acid bacterium that plays an important role in the elaboration of wine. It is often added as a starter culture to carry out malolactic conversion. Given the economic importance of this reaction, the taxonomic structure of this species has been studied in detail. In the present work, phenotypic and molecular approaches were used to identify 121 lactic acid bacteria strains isolated from the wines of three winemaking regions of Portugal. The strains were differentiated at the genomic level by M13-PCR fingerprinting. Twenty-seven genomic clusters represented by two or more isolates and 21 single-member clusters, based on an 85% similarity level, were recognized by hierarchic numerical analysis. M13-PCR fingerprinting patterns revealed a high level of intraspecific genomic diversity in O. oeni. Moreover, this diversity could be partitioned according to the geographical origin of the isolates. Thus, M13-PCR fingerprint analysis may be an appropriate methodology to study the O. oeni ecology of wine during malolactic fermentation as well as to trace new malolactic starter cultures and evaluate their dominance over the native microbiota (AU)


No disponible


Assuntos
Oenococcus/isolamento & purificação , Vinho/microbiologia , Biota , Portugal , Ácido Láctico/análise , Variação Genética , Bacteriófago M13/ultraestrutura
20.
J Hazard Mater ; 191(1-3): 277-86, 2011 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-21592655

RESUMO

Great attention is focused on the microbial treatment of metal contaminated environments. Three bacterial strains, 1C2, 1ZP4 and EC30, belonging to genera Cupriavidus, Sphingobacterium and Alcaligenes, respectively, showing high tolerance to Zn and Cd, up to concentrations of 1000ppm, were isolated from a contaminated area in Northern Portugal. Their contribution to Zn and Cd removal from aqueous streams using immobilised alginate, pectate and a synthetic cross-linked polymer was assessed. In most cases, matrices with immobilised bacteria showed better metal removal than the non-inoculated material alone. For the immobilisation with all the polymers, 1C2 was the strain that increased the removal of Zn the most, whereas EC30 was the most promising for Cd removal, especially when combined with the synthetic polymer with up to a ca. 11-fold increase in metal removal when compared to the polymer alone. Removal of individual metals from binary mixtures showed that there was differential immobilisation. There was greater removal of Cd than Zn (removals up to 40% higher than those showed for Zn). The results show that metal contaminated environments constitute a reservoir of microorganisms resistant/tolerant to heavy metals that have the capacity to be exploited in bioremediation strategies. Capsule immobilisation of bacteria in the naturally occurring alginate and pectate and in a synthetic cross-linked polymer increased the Zn and Cd removal abilities from single and binary contaminated waters; the applications with the synthetic polymer were the most promising for Cd and Zn removal in single and binary mixtures.


Assuntos
Bactérias/metabolismo , Metais Pesados/isolamento & purificação , Polímeros/química , Bactérias/crescimento & desenvolvimento , Metais Pesados/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...