Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 133
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
Extremophiles ; 23(3): 359-365, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30810807

RESUMO

The use of stable isotope (SI) labelling and tracing of live diets is currently considered one of the most comprehensive tools to detect their uptake and assimilation by aquatic organisms. These techniques are indeed widely used in nutritional studies to follow the fate of specific microbial dietary components, unraveling trophic interactions. Nevertheless, to the current date our understanding of aquatic trophic relationships has yet to include a whole domain of life, the Archaea. The aim of the present research was, therefore, to describe a halophilic Archaea (haloarchaea) labelling procedure, using the SI 13C and 15N, to enable the application of SI tracing in future studies of haloarchaea consumption by aquatic metazoans. To this end, three 13C enriched carbon sources and two 15N enriched nitrogen sources were tested as potential labels to enrich cells of three haloarchaea strains when supplemented to the culture medium. Our overall results indicate 13C-glycerol as the most effective carbon source to achieve an efficient 13C enrichment in haloarchaea cells, with Δδ13C values above 5000‰ in all tested haloarchaea strains. As for 15N enriched nitrogen sources, both (15NH4)2SO4 and 15NH4Cl seem to be readily assimilated, also resulting in efficient 15N enrichment in haloarchaea cells, with Δδ15N values higher than 20,000‰. We believe that the proposed methodology will allow for the use of SI labelled haloarchaea biomass in feeding tests, potentially providing unambiguous confirmation of the assimilation of haloarchaea biomass by aquatic metazoans.


Assuntos
Biomassa , Isótopos de Carbono/química , Cadeia Alimentar , Halobacteriales/crescimento & desenvolvimento , Marcação por Isótopo/métodos , Isótopos de Nitrogênio/química , Animais
2.
Int Endod J ; 52(7): 1040-1050, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30756431

RESUMO

AIM: To investigate the plasma concentrations of glucose, insulin and tumour necrosis factor-α (TNF-α) of rats with maternal apical periodontitis (AP) and to explore the effect of maternal inflammation on the initial steps of insulin signalling and the inflammatory pathway in the gastrocnemius muscle (GM) and periepididymal white adipose tissue (pWAT) of adult offspring. METHODOLOGY: Fifteen female Wistar rats were distributed into a control group (CN), a group with 1 tooth with AP (1AP) and a group with 4 teeth with AP (4AP). Thirty days following induction of AP, female rats from all groups were mated with healthy male rats. When male offspring reached 75 days of age, plasma concentrations of glucose, insulin and TNF-α were quantified. Insulin resistance was evaluated by the homoeostasis model assessment of insulin resistance (HOMA-IR) index. Phosphorylation status of pp185 tyrosine, insulin receptor substrate 1 (IRS-1) serine, IκB kinase α/ß (IKKα/ß) and c-Jun N-terminal kinase (JNK) in the GM and pWAT were measured by Western blot. Analysis of variance was performed, followed by the Tukey's post hoc test. P values <0.05 were considered to be statistically significant. RESULTS: Maternal AP promoted insulin resistance, impaired the initial steps of insulin signalling, significantly increased plasma concentrations of insulin (P < 0.001) and TNF-α (P < 0.05), and enhanced IKKα/ß phosphorylation in the GM and pWAT (P < 0.05) of adult offspring. However, maternal AP did not affect fasting glycaemia and JNK phosphorylation in the GM and pWAT of adult offspring. CONCLUSIONS: Maternal AP was associated with insulin resistance in adult offspring through alterations in insulin signalling and inflammation pathways. The study provides information on the impact of maternal AP on the development of metabolic alterations such as insulin resistance in adult offspring and reinforces the importance of preventing maternal AP in order to maintain the general health of offspring.


Assuntos
Resistência à Insulina , Periodontite Periapical , Filhos Adultos , Animais , Glicemia , Feminino , Humanos , Masculino , Ratos , Ratos Wistar , Fator de Necrose Tumoral alfa
3.
J Dairy Sci ; 101(11): 10440-10455, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30172395

RESUMO

The objective of the current study was to evaluate the effects of 2 intramammary infusions of lipopolysaccharide (LPS) on inflammatory and reproductive parameters and endometrial gene expression of lactating Holstein cows. At 35 ± 7 d in milk, 20 cows were submitted to a Double Ovsynch program and randomly assigned to control (n = 11) and LPS (n = 9) treatments. Cows from the LPS treatment received 2 intramammary infusions of 25 µg of LPS after morning milking on d 5 and 10 post-AI, whereas control cows were infused with only saline. Blood samples were taken and ultrasound scanning of the ovaries was performed during the entire study before and after AI to determine haptoglobin, tumor necrosis factor-α, and progesterone concentrations as well as response to the hormonal protocol and corpus luteum diameter. Milk yield was evaluated and samples were taken for somatic cell count at 0, 10, 24, 34, and 96 h relative to each infusion. Rumen-reticular temperature was recorded using a rumen-reticular bolus logger and summarized hourly. On d 15 post-AI, uterine flushing for conceptus recovery and endometrial biopsies were performed. Samples of endometrium from cows with positive embryo recovery (control = 5; LPS = 6) were submitted to mRNA extraction and quantitative reverse-transcription PCR analysis of 96 target genes. Haptoglobin concentrations in plasma were greater for LPS treatment (control = 0.24 ± 0.07, LPS = 0.89 ± 0.06 optical density), but tumor necrosis factor-α concentrations were similar (control = 0.67 ± 0.11, LPS = 0.46 ± 0.11 ng/mL) between treatments. Lipopolysaccharide reduced milk yield after treatment (control = 34.3 ± 1.5, LPS = 29.4 ± 1.6 kg/d), whereas somatic cell count (log) was greater in LPS-treated cows until 34 h after infusions (control = 2.3 ± 0.1, LPS = 3.3 ± 0.1 cells/mL of milk). Rumen-reticular temperature of LPS cows was elevated between 5 and 10 h after each infusion compared with control cows (control = 39.5 ± 0.1, LPS = 40.1 ± 0.1°C). Progesterone concentration after AI was unaffected by treatment or pregnancy status as well as corpus luteum diameter and conceptus length on d 15. Lipopolysaccharide treatment altered the expression of 13 key genes in the endometrium (mostly upregulated), whereas another 17 tended to be modulated. Modified gene expression included genes related to immune response (PTX3 = 2.34-fold increase; IL6 = 3.42-fold increase; and TCN1 = 2.52-fold increase), adhesion molecules (CADM3 = 1.93-fold increase; MMP19 = 1.49-fold increase; EMMPRIN = 1.20-fold increase; SELL = 1.91-fold increase), Wnt signaling pathway (WNT2, FZD4, and FZD7, all <1.5-fold increase), and interferon-stimulated genes (BMP15 = 0.27-fold decrease; ISG15 = 2.17-fold increase, and MX2 = 2.23-fold increase). In summary, intramammary infusions of LPS were able to trigger an inflammatory response with no effect on corpus luteum diameter and concentration of progesterone in plasma. However, a limited but important set of modulations in the endometrium gene expression at d 15 of gestation was found.


Assuntos
Regulação da Expressão Gênica/efeitos dos fármacos , Lipopolissacarídeos/administração & dosagem , Mastite Bovina/induzido quimicamente , Leite/metabolismo , Reprodução , Animais , Bovinos , Corpo Lúteo/fisiologia , Endométrio/fisiologia , Feminino , Inflamação/induzido quimicamente , Lactação , Gravidez , Progesterona/sangue , Distribuição Aleatória , Rúmen/fisiologia , Útero/fisiologia
4.
Nutr Metab Cardiovasc Dis ; 27(6): 525-533, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28511902

RESUMO

BACKGROUND AND AIMS: Studies in the paediatric population have shown inconsistent associations between cardiorespiratory fitness and inflammation independently of adiposity. The purpose of this study was (i) to analyse the combined association of cardiorespiratory fitness and adiposity with high-sensitivity C-reactive protein (hs-CRP), and (ii) to determine whether adiposity acts as a mediator on the association between cardiorespiratory fitness and hs-CRP in children and adolescents. METHODS AND RESULTS: This cross-sectional study included 935 (54.7% girls) healthy children and adolescents from Bogotá, Colombia. The 20 m shuttle run test was used to estimate cardiorespiratory fitness. We assessed the following adiposity parameters: body mass index, waist circumference, and fat mass index and the sum of subscapular and triceps skinfold thickness. High sensitivity assays were used to obtain hs-CRP. Linear regression models were fitted for mediation analyses examined whether the association between cardiorespiratory fitness and hs-CRP was mediated by each of adiposity parameters according to Baron and Kenny procedures. Lower levels of hs-CRP were associated with the best schoolchildren profiles (high cardiorespiratory fitness + low adiposity) (p for trend <0.001 in the four adiposity parameters), compared with unfit and overweight (low cardiorespiratory fitness + high adiposity) counterparts. Linear regression models suggest a full mediation of adiposity on the association between cardiorespiratory fitness and hs-CRP levels. CONCLUSIONS: Our findings seem to emphasize the importance of obesity prevention in childhood, suggesting that having high levels of cardiorespiratory fitness may not counteract the negative consequences ascribed to adiposity on hs-CRP.


Assuntos
Adiposidade , Biomarcadores/sangue , Proteína C-Reativa/análise , Aptidão Cardiorrespiratória , Mediadores da Inflamação/sangue , Inflamação/epidemiologia , Obesidade Infantil/epidemiologia , Adolescente , Fatores Etários , Criança , Colômbia/epidemiologia , Estudos Transversais , Feminino , Humanos , Inflamação/sangue , Inflamação/diagnóstico , Inflamação/prevenção & controle , Modelos Lineares , Masculino , Obesidade Infantil/diagnóstico , Obesidade Infantil/fisiopatologia , Obesidade Infantil/prevenção & controle , Prevalência , Fatores de Risco
5.
Int Endod J ; 50(2): 161-166, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26821330

RESUMO

AIM: To evaluate the effects of a long period of oestrogen deficiency on the development of apical periodontitis in rats. METHODOLOGY: Wistar rats (n = 24), 3 months old, evaluated by vaginal cytology, were included in the study. Twelve animals were ovariectomized (OVX group) and the other 12 were sham operated (control group). One hundred and twenty days after castration, the pulps of the left mandibular first molars were exposed to induce the development of apical periodontitis. Body mass was verified on a weekly basis. Following 21 and 40 days of lesion induction, the animals were sacrificed. Blood was collected for biochemical analysis, and mandibles were removed for radiographic analysis. Comparative analysis of the data was performed by the nonparametric Kruskal-Wallis and Dunn's multiple-comparisons tests. The t-test was applied to compare the oestrogen levels between control and OVX groups. RESULTS: Radiographs revealed that apical periodontitis lesions were significantly larger in the 40-day OVX group when compared with both 40-day (P < 0.05) and 21-day (P < 0.001) control groups. Serum oestrogen levels were significantly lower in the OVX group (P < 0.01), confirming the efficacy of castration. Oestrogen deficiency resulted in significantly greater body mass gain (P < 0.01) in 40-day OVX group when compared with 40-day control group. Serum concentrations of calcium were similar between groups (P > 0.05). Alkaline phosphatase levels, although higher in the OVX groups (21 and 40 days), were not significantly different. CONCLUSIONS: Ovariectomized rats had significantly larger apical periodontitis lesions after 40 days of pulp exposure when compared with controls. These findings suggest that bone alterations as a result of long periods of oestrogen deficiency can influence the progression of apical periodontitis.


Assuntos
Estrogênios/deficiência , Periodontite Periapical/etiologia , Animais , Feminino , Ovariectomia , Ratos , Ratos Wistar
6.
J Comput Neurosci ; 41(3): 323-337, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27696002

RESUMO

Zinc, a transition metal existing in very high concentrations in the hippocampal mossy fibers from CA3 area, is assumed to be co-released with glutamate and to have a neuromodulatory role at the corresponding synapses. The synaptic action of zinc is determined both by the spatiotemporal characteristics of the zinc release process and by the kinetics of zinc binding to sites located in the cleft area, as well as by their concentrations. This work addresses total, free and complexed zinc concentration changes, in an individual synaptic cleft, following single, short and long periods of evoked zinc release. The results estimate the magnitude and time course of the concentrations of zinc complexes, assuming that the dynamics of the release processes are similar to those of glutamate. It is also considered that, for the cleft zinc concentrations used in the model (≤ 1 µM), there is no postsynaptic zinc entry. For this reason, all released zinc ends up being reuptaken in a process that is several orders of magnitude slower than that of release and has thus a much smaller amplitude. The time derivative of the total zinc concentration in the cleft is represented by the difference between two alpha functions, corresponding to the released and uptaken components. These include specific parameters that were chosen assuming zinc and glutamate co-release, with similar time courses. The peak amplitudes of free zinc in the cleft were selected based on previously reported experimental cleft zinc concentration changes evoked by single and multiple stimulation protocols. The results suggest that following a low amount of zinc release, similar to that associated with one or a few stimuli, zinc clearance is mainly mediated by zinc binding to the high-affinity sites on the NMDA receptors and to the low-affinity sites on the highly abundant GLAST glutamate transporters. In the case of higher zinc release brought about by a larger group of stimuli, most zinc binding occurs essentially to the GLAST transporters, having the corresponding zinc complex a maximum concentration that is more than one order of magnitude larger than that for the high and low affinity NMDA sites. The other zinc complexes considered in the model, namely those formed with sites on the AMPA receptors, calcium and KATP channels and with ATP molecules, have much smaller contributions to the synaptic zinc clearance.


Assuntos
Modelos Neurológicos , Fibras Musgosas Hipocampais/fisiologia , Sinapses/metabolismo , Zinco/metabolismo , Animais , Cálcio/metabolismo , Ácido Glutâmico/metabolismo , Receptores de AMPA/fisiologia , Receptores de N-Metil-D-Aspartato/metabolismo , Fatores de Tempo
7.
Soft Matter ; 12(1): 77-86, 2016 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-26439171

RESUMO

A one-step melt-mixing method is proposed to study dispersion and re-agglomeration phenomena of the as-received and functionalized graphite nanoplates in polypropylene melts. Graphite nanoplates were chemically modified via 1,3-dipolar cycloaddition of an azomethine ylide and then grafted with polypropylene-graft-maleic anhydride. The effect of surface functionalization on the dispersion kinetics, nanoparticle re-agglomeration and interface bonding with the polymer is investigated. Nanocomposites with 2 or 10 wt% of as-received and functionalized graphite nanoplates were prepared in a small-scale prototype mixer coupled to a capillary rheometer. Samples were collected along the flow axis and characterized by optical microscopy, scanning electron microscopy and electrical conductivity measurements. The as-received graphite nanoplates tend to re-agglomerate upon stress relaxation of the polymer melt. The covalent attachment of a polymer to the nanoparticle surface enhances the stability of dispersion, delaying the re-agglomeration. Surface modification also improves interfacial interactions and the resulting composites presented improved electrical conductivity.

8.
Genet Mol Res ; 15(2)2016 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-27323193

RESUMO

In the face of a possible loss of genetic diversity in plants due the environmental changes, actions to ensure the genetic variability are an urgent necessity. The extraction of Brazilian pepper fruits is a cause of concern because it results in the lack of seeds in soil, hindering its distribution in space and time. It is important to address this concern and explore the species, used by riparian communities and agro-factories without considering the need for keeping the seeds for natural seed banks and for species sustainability. The objective of this study was to evaluate the structure and the genetic diversity in natural Brazilian pepper populations (Schinus terebinthifolius Raddi). Twenty-two alleles in 223 individuals were identified from eight forest remnants located in the states of Minas Gerais, Espírito Santo, and Sergipe. All populations presented loci in Hardy-Weinberg equilibrium deviation. Four populations presented six combinations of loci in linkage disequilibrium. Six exclusive alleles were detected in four populations. Analysis of molecular variance showed the absence of diversity between regions and that between the populations (GST) was 41%. Genetic diversity was structured in seven clusters (ΔK7). Brazilian pepper populations were not structured in a pattern of isolation by distance and present genetic bottleneck. The populations São Mateus, Canastra, Barbacena, and Ilha das Flores were identified as management units and may support conservation projects, ecological restoration and in implementation of management plans for Brazilian pepper in the State of Sergipe.


Assuntos
Anacardiaceae/genética , Variação Genética , Brasil , DNA de Plantas , Marcadores Genéticos , Genótipo , Repetições de Microssatélites
9.
J Contemp Dent Pract ; 17(11): 902-906, 2016 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-27965498

RESUMO

INTRODUCTION: The study aimed to compare the shaping and preservation of the original curvature of simulated curved root canals using the following instruments: Reciproc (Rcp), WaveOne (Wo), and the ProTaper Next system (Ptn). MATERIALS AND METHODS: A total of 45 resin blocks with simulated curved root canals were divided into three groups (n = 15), prepared using the Rcp (R25), Wo (25/0.8), and Ptn (X2) instruments. Standardized photographs were taken before and after canal instrumentation. After the superimposition of the images, the amount of resin removed from the curvature's inner and outer walls was measured at six apical levels, at intervals of 1 mm. The canals' angles of curvature before and after instrumentation were subtracted. RESULTS: There were no significant differences between the instruments in terms of the total amount of resin removed of the inner or outer walls of the apical curvature (p > 0.05). The Rcp instruments provided the best resin removed ratios between the walls. The means of the change in angle were as follows: Wo = 2.15°, Ptn = 0.92°, and Rcp = 0.21°. WaveOne caused significantly higher deviations than Rcp. CONCLUSION: All of the instruments demonstrated a tendency to straighten the simulated root canal. Instruments that use rotary movement achieved an effect similar to that of the reciprocating instruments in relation to change in angle. CLINICAL SIGNIFICANCE: Deviations from the original shape of the root canal could have a negative impact on the quality of a filling and consequently on the success of the endodontic treatment.


Assuntos
Simulação por Computador , Ligas Dentárias/química , Cavidade Pulpar/anatomia & histologia , Preparo de Canal Radicular/instrumentação , Preparo de Canal Radicular/métodos , Tratamento do Canal Radicular/instrumentação , Instrumentos Odontológicos , Desenho de Equipamento , Humanos , Teste de Materiais , Modelos Anatômicos , Níquel , Fotografação , Cimentos de Resina , Rotação , Titânio/química , Ápice Dentário/anatomia & histologia
10.
Genet Mol Res ; 13(4): 8876-87, 2014 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-25366779

RESUMO

Two accessions of ornamental pepper Capsicum annuum L., differing in most of the characters studied, were crossed, resulting in the F1 generation, and the F2 generation was obtained through self-fertilization of the F1 generation. The backcross generations RC1 and RC2 were obtained through crossing between F1 and the parents P1 and P2, respectively. Morpho-agronomic characterization was performed based on the 19 quantitative descriptors of Capsicum. The data obtained were subjected to generation analysis, in which the means and additive variance (σa(2)), variance due to dominance deviation (σd(2)), phenotypic variance (σf(2)), genetic variance (σg(2)) and environmental variance (σm(2)) were calculated. For the full model, we estimated the mean effects of all possible homozygotes, additives, dominants, and epistatics: additive-additive, additive-dominant, and dominant-dominant. For the additive-dominant model, we estimated the additive effects, dominant effects and mean effects of possible homozygotes. The character fruit dry matter had the lowest value for broad sense heritability (0.42), and the highest values were found for fresh matter and fruit weight, 0.91 and 0.92, respectively. The lowest value for narrow sense heritability was for the minor fruit diameter character (0.33), and the highest values were found for seed yield per fruit and fresh matter, 0.87 and 0.84, respectively. The additive-dominant model explained only the variation found in plant height, canopy width, stem length, corolla diameter, leaf width, and pedicel length, but in the other characters, the epistatic effects showed significant values.


Assuntos
Capsicum/genética , Epistasia Genética , Frutas/genética , Característica Quantitativa Herdável , Algoritmos , Capsicum/classificação , Cruzamentos Genéticos , Interação Gene-Ambiente , Genes Dominantes/genética , Genes de Plantas/genética , Variação Genética , Genótipo , Modelos Genéticos , Fenótipo , Autofertilização
11.
Braz J Biol ; 84: e278601, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38422291

RESUMO

The use of biomass for energy production constitutes a promising strategy that warrants the search for new sources of biomass. Elephant grass has been gaining notoriety due to its high dry matter yield and rapid growth. The present study was carried out to quantify the genetic divergence of nine elephant grass half-sib families in order to identify genotypes with greater genetic divergence and productive potential for hybridization, using the hierarchical clustering methodology based on principal components. Half-sib families were generated using genotypes from the Active Germplasm Bank of Elephant Grass. The experiment was laid out in a randomized-block design with nine half-sib families, three replicates, and eight plants per plot. A total of 216 genotypes of elephant grass were evaluated. Principal component (PC), biplot, and hierarchical clustering analyses for diversity estimation were conducted using R software. The first two PCs of biplot analysis accounted for 64% of the cumulative variation. Dry matter yield was the most important trait for genotype discrimination (0.89), followed by plant height (0.67) and stem diameter (0.61) in PC1. In this analysis, the distances between accessions were considered and there were no family links, which indicates the existence of wide variability within the evaluated families, since genotypes belonging to the same family were not grouped together, but rather distributed into different groups. Crosses between genotypes of group three and genotypes of groups one and two are recommended for the development of high-yielding genotypes when aiming at energy production.


Assuntos
Variação Genética , Hibridização Genética , Biomassa , Variação Genética/genética , Genótipo , Fenótipo , Distribuição Aleatória
12.
Br J Cancer ; 109(10): 2646-53, 2013 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-24129247

RESUMO

BACKGROUND: Renal cell tumours (RCTs) are clinically, morphologically and genetically heterogeneous. Accurate identification of renal cell carcinomas (RCCs) and its discrimination from normal tissue and benign tumours is mandatory. We, thus, aimed to define a panel of microRNAs that might aid in the diagnostic workup of RCTs. METHODS: Fresh-frozen tissues from 120 RCTs (clear-cell RCC, papillary RCC, chromophobe RCC (chRCC) and oncocytomas: 30 cases each), 10 normal renal tissues and 60 cases of ex-vivo fine-needle aspiration biopsies from RCTs (15 of each subtype validation set) were collected. Expression levels of miR-21, miR-141, miR-155, miR-183 and miR-200b were assessed by quantitative reverse transcription-PCR. Receiver operator characteristic curves were constructed and the areas under the curve were calculated to assess diagnostic performance. Disease-specific survival curves and a Cox regression model comprising all significant variables were computed. RESULTS: Renal cell tumours displayed significantly lower expression levels of miR-21, miR-141 and miR-200b compared with that of normal tissues, and expression levels of all miRs differed significantly between malignant and benign RCTs. Expression analysis of miR-141 or miR-200b accurately distinguished RCTs from normal renal tissues, oncocytoma from RCC and chRCC from oncocytoma. The diagnostic performance was confirmed in the validation set. Interestingly, miR-21, miR-141 and miR-155 expression levels showed prognostic significance in a univariate analysis. CONCLUSION: The miR-141 or miR-200b panel accurately distinguishes RCC from normal kidney and oncocytoma in tissue samples, discriminating from normal kidney and oncocytoma, whereas miR-21, miR-141 and miR-155 convey prognostic information. This approach is feasible in fine-needle aspiration biopsies and might provide an ancillary tool for routine diagnosis.


Assuntos
Biomarcadores Tumorais , Carcinoma de Células Renais/diagnóstico , Detecção Precoce de Câncer/métodos , Neoplasias Renais/diagnóstico , MicroRNAs/fisiologia , Transcriptoma , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/genética , Carcinoma de Células Renais/genética , Feminino , Humanos , Neoplasias Renais/genética , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Reprodutibilidade dos Testes , Adulto Jovem
13.
J Environ Manage ; 105: 1-11, 2012 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-22507455

RESUMO

Aquatic sediments contaminated with heavy metals originating from mining and metallurgical activities pose significant risk to the environment and human health. These sediments not only act as a sink for heavy metals, but can also constitute a secondary source of heavy metal contamination. A variety of sorbent materials has demonstrated the potential to immobilize heavy metals. However, the complexity of multi-element contamination makes choosing the appropriate sorbent mixture and application dosage highly challenging. In this paper, a strategic framework is designed to systematically address the development of an in-situ sediment remediation solution through Assessment, Feasibility and Performance studies. The decision making tools and the experimental procedures needed to identify optimum sorbent mixtures are detailed. Particular emphasis is given to the utilization and combination of commercially available and waste-derived sorbents to enhance the sustainability of the solution. A specific case study for a contaminated sediment site in Northern Belgium with high levels of As, Cd, Pb and Zn originating from historical non-ferrous smelting is presented. The proposed framework is utilized to achieve the required remediation targets and to meet the imposed regulations on material application in natural environments.


Assuntos
Recuperação e Remediação Ambiental/métodos , Sedimentos Geológicos/química , Metais Pesados/química , Poluentes Químicos da Água/química , Adsorção
14.
Braz J Biol ; 84: e253731, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35019101

RESUMO

Petroleum water soluble fraction (WSF) impairs organisms, but damages may vary among cell and tissue levels. The aim of the present study was to evaluate the acute (24 h, 48 h, 72 h) and subchronic effects (36 days) of WSF (0%, 25% and 100%) in juveniles of the Neotropical top predator fish Hoplias aff. malabaricus. The effects of WSF were evaluated at a molecular level using the comet assay and micronucleus test for genome damage; and at a morphological level through histological identification of liver pathologic lesions. In both acute and subchronic exposure we found low levels of DNA damage (< 10% of comet tail) and non-significant frequency of micronucleus in WSF exposed fish. The most significant liver lesions in WSF exposed fish were fatty vacuolization, hypertrophy and focal necrosis. Since these tissue injuries were progressive and persistent, their irreversibility may negatively affect fish recruitment, even in a such resistant top predator.


Assuntos
Caraciformes , Petróleo , Poluentes Químicos da Água , Animais , Água Doce , Fígado , Petróleo/toxicidade , Poluentes Químicos da Água/toxicidade
15.
J Fish Biol ; 79(2): 546-55, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21781110

RESUMO

The distribution limits in the Atlantic of Callorhinchus callorynchus (Callorhinchidae) and Odontesthes argentinensis (Atherinopsidae) are extended northwards to 22° 22' S and 22° 31' S, respectively, whereas that of Lile piquitinga (Clupeidae) is extended southwards to 22° 22' S. Their occurrence in the north of Rio de Janeiro State is discussed. Remarks on the osteology of O. argentinensis, and morphometric and meristic data of L. piquitinga, are also provided.


Assuntos
Peixes , Animais , Oceano Atlântico , Brasil , Ecossistema , Feminino , Peixes/anatomia & histologia , Geografia
16.
Sci Total Environ ; 764: 142869, 2021 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-33129522

RESUMO

The Vilariça River (located in the northeast of Portugal) is inserted in an agricultural basin and it was chosen to replace the spawning grounds for fish, that was lost due to the construction of dams in the Sabor River. Thus, it is essential to study the effect of agricultural practices on water quality and in the health status of fish. The barbel (Luciobarbus bocagei) and Douro nase (Pseudochondrostoma duriense) were the selected species and the work was developed in two seasons (Summer 2016 and Winter 2017). For that, the histopathological changes of fish gill were used as biomarkers, through a semi-quantitative approach that considers the injuries severity. And the water quality assessment criteria followed the methodologies proposed for classifying the status of surface water bodies from Portugal. The current study showed severe histopathological changes in both species and both seasons, and the water was classified as polluted and extremely polluted in Summer and Winter respectively. The pollution in Summer was due to high temperatures, low dissolved oxygen and major concentration of As and Mn, and in Winter is due to the high concentration of Total Suspended Solids, nitrites and Cd. The increase of values of physico-chemical parameters on the water was caused by the less streamflow and excessive agricultural fertilization in Summer which arrive the river by irrigation, and by the erosion of soil particles with heavy metals associated in Winter. Also, the canonical analysis showed that physico-chemical parameters concentrations in Summer justify the major prevalence of aneurism in barbel and exudate in nase and Winter the major prevalence of hypertrophy in barbel. In conclusion, the study showed that the gill injuries of barbel and Douro nase was correlated with the water quality and it is influenced by seasonal agricultural practices and the flow regime.


Assuntos
Cyprinidae , Poluentes Químicos da Água , Animais , Monitoramento Ambiental , Brânquias/química , Portugal , Rios , Estações do Ano , Poluentes Químicos da Água/análise
17.
Braz J Med Biol Res ; 54(8): e10679, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34037091

RESUMO

In spite of the many studies examining alcohol consumption, recent reviews have indicated that binge drinking has not been extensively studied. Furthermore, it is becoming increasingly clear that sleep is associated with many physiological functions and to drug addictions. The present study aimed to evaluate the relationship between alcohol binge drinking and insomnia in college students of health sciences. All first-year health sciences students (n=286) were evaluated in a cross-sectional study. Envelopes containing the Insomnia Severity Index (ISI), the Alcohol, Smoking, and Substance Involvement Screening Test (ASSIST), and questions capturing sociodemographic data were distributed and collected in classes. It was found that most non-drinkers were female (70.6%), although there were no sex-related differences in the number of binge drinkers (more than 5 drinks on each occasion at least once a week), allowing statistical comparison. The Mann-Whitney U test indicated that the ISI scores were significantly greater in female than male binge drinkers (P=0.014). Moderate or severe insomnia was reported by 23% of the sample, with alcohol being the most frequently associated substance. A specialized intervention was suggested by ASSIST: brief for marijuana (19.2%) and tobacco (23.3%) use, and moderate (31.5%) or intensive (1.4%) for alcohol consumers. The data highlighted the need to pay attention to the habits of college students beyond obtaining scientific information. New data suggesting the influence of genetics on insomnia may be of importance when performing additional studies on the sex differences in alcohol binge drinking.


Assuntos
Consumo Excessivo de Bebidas Alcoólicas , Distúrbios do Início e da Manutenção do Sono , Consumo de Bebidas Alcoólicas/epidemiologia , Consumo Excessivo de Bebidas Alcoólicas/epidemiologia , Brasil/epidemiologia , Estudos Transversais , Feminino , Humanos , Masculino , Distúrbios do Início e da Manutenção do Sono/epidemiologia , Estudantes , Universidades
18.
Cytogenet Genome Res ; 127(2-4): 191-203, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-20215729

RESUMO

Chromosomes of the South American geckos Gymnodactylus amarali and G. geckoides from open and dry areas of the Cerrado and Caatinga biomes in Brazil, respectively, were studied for the first time, after conventional and AgNOR staining, CBG- and RBG-banding, and FISH with telomeric sequences. Comparative analyses between the karyotypes of open areas and the previously studied Atlantic forest species G. darwinii were also performed. The chromosomal polymorphisms detected in populations of G. amarali from the states of Goiás and Tocantins is the result of centric fusions (2n = 38, 39 and 40), suggesting a differentiation from a 2n = 40 ancestral karyotype and the presence of supernumerary chromosomes. The CBG- and RBG-banding patterns of the Bs are described. G. geckoides has 40 chromosomes with gradually decreasing sizes, but it is distinct from the 2n = 40 karyotypes of G. amarali and G. darwinii due to occurrence of pericentric inversions or centromere repositioning. NOR location seems to be a marker for Gymnodactylus, as G. amarali and G. geckoides share a medium-sized subtelocentric NOR-bearing pair, while G. darwinii has NORs at the secondary constriction of the long arm of pair 1. The comparative analyses indicate a non-random nature of the Robertsonian rearrangements in the genus Gymnodactylus.


Assuntos
Cromossomos/genética , Evolução Molecular , Rearranjo Gênico/genética , Lagartos/genética , Animais , Brasil , Bandeamento Cromossômico , Hibridização in Situ Fluorescente , Cariotipagem , Coloração pela Prata , Telômero/genética , Árvores
19.
Tech Coloproctol ; 13(1): 55-9, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19288244

RESUMO

BACKGROUND: Anorectal transplantation is a valid procedure for the treatment of anorectal dysfunction; however, the lack of a suitable animal model has hampered the development of this method. We describe a simple technique for anorectal transplantation in the rat and compare this procedure with colostomy. METHODS: The anorectal segment including the skin surrounding the anus were freed by abdominal and perineal dissection. In a heterotopically transplanted group the segment was exteriorized by the formation of an anus through an abdominal incision. In an orthotopically transplanted group the segment was replaced in its original position and reimplanted by suturing. In another group a distal colostomy was performed. A sham-treated control group (simulated surgical procedure) was also included. Changes in behavior, characteristics of the stool, body weight and survival rate were assessed by daily clinical examination. Moribund animals, those with a weight loss of more than 30%, and those surviving at 1 month were killed by an overdose of anesthetic. The results were analyzed using the Mann Whitney, Student's t and chi-squared tests, and p<0.05 was considered significant. RESULTS: Within 4 days after the operation, animals submitted to orthotopic or heterotopic transplantation had achieved normal defecation, body weight gain and clinical evolution similar to the sham-treated group. The overall mortality in these groups was 4.16%. In contrast, colostomized animals showed a high incidence of diarrhea, intestinal obstruction, stress posture and violent behavior (p

Assuntos
Canal Anal/transplante , Colostomia/métodos , Incontinência Fecal/cirurgia , Reto/transplante , Animais , Defecação , Modelos Animais de Doenças , Incontinência Fecal/fisiopatologia , Masculino , Ratos , Ratos Wistar , Resultado do Tratamento
20.
Braz. j. biol ; 84: e253731, 2024. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1355871

RESUMO

Abstract Petroleum water soluble fraction (WSF) impairs organisms, but damages may vary among cell and tissue levels. The aim of the present study was to evaluate the acute (24 h, 48 h, 72 h) and subchronic effects (36 days) of WSF (0%, 25% and 100%) in juveniles of the Neotropical top predator fish Hoplias aff. malabaricus. The effects of WSF were evaluated at a molecular level using the comet assay and micronucleus test for genome damage; and at a morphological level through histological identification of liver pathologic lesions. In both acute and subchronic exposure we found low levels of DNA damage (< 10% of comet tail) and non-significant frequency of micronucleus in WSF exposed fish. The most significant liver lesions in WSF exposed fish were fatty vacuolization, hypertrophy and focal necrosis. Since these tissue injuries were progressive and persistent, their irreversibility may negatively affect fish recruitment, even in a such resistant top predator.


Resumo A fração solúvel de petróleo (WSF) prejudica os organismos, porém os danos podem variar entre os níveis celular e tecidual. O objetivo do presente estudo foi avaliar o efeito agudo (24 h, 48 h e 72 h) e subcrônico (36 dias) da WSF (0%, 25% e 100%) em juvenis do peixe neotropical predador topo Hoplias aff. malabaricus. Os efeitos da WSF foram avaliados no nível molecular utilizando o ensaio do cometa e o teste do micronúcleo para o dano genômico e no nível morfológico através da identificação histológica de lesões patológicas no fígado. Em ambas exposições (aguda e subcrônica) encontramos baixos níveis de dano no DNA (< 10% de DNA na cauda do cometa) e frequência de micronúcleos não significativa em peixes expostos a WSF. As lesões mais significativas no fígado dos peixes expostos a WSF foram a vacuolização lipídica, hipertrofia e focos de necroses. Como estas lesões foram progressivas e persistentes, sua irreversibilidade pode afetar negativamente o recrutamento dos peixes, mesmo sendo um predador topo resistente.


Assuntos
Animais , Poluentes Químicos da Água/toxicidade , Petróleo/toxicidade , Caraciformes , Água Doce , Fígado
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA