RESUMO
BACKGROUND: Surgery is the primary treatment that can offer potential cure for gastric cancer, but is associated with significant risks. Identifying optimal surgical approaches should be based on comparing outcomes from well designed trials. Currently, trials report different outcomes, making synthesis of evidence difficult. To address this, the aim of this study was to develop a core outcome set (COS)-a standardized group of outcomes important to key international stakeholders-that should be reported by future trials in this field. METHODS: Stage 1 of the study involved identifying potentially important outcomes from previous trials and a series of patient interviews. Stage 2 involved patients and healthcare professionals prioritizing outcomes using a multilanguage international Delphi survey that informed an international consensus meeting at which the COS was finalized. RESULTS: Some 498 outcomes were identified from previously reported trials and patient interviews, and rationalized into 56 items presented in the Delphi survey. A total of 952 patients, surgeons, and nurses enrolled in round 1 of the survey, and 662 (70 per cent) completed round 2. Following the consensus meeting, eight outcomes were included in the COS: disease-free survival, disease-specific survival, surgery-related death, recurrence, completeness of tumour removal, overall quality of life, nutritional effects, and 'serious' adverse events. CONCLUSION: A COS for surgical trials in gastric cancer has been developed with international patients and healthcare professionals. This is a minimum set of outcomes that is recommended to be used in all future trials in this field to improve trial design and synthesis of evidence.
RESUMO
The aim of this paper was to evaluate the effects of including virginiamycin (VM), sodium monensin (MON) or the association (VM+MON) in the energetic mineral supplement, on the intake and performance of beef cattle on pasture. Forty Nellore heifers with 24 months of age and initial body weight (BW) of 251.5±16.6kg, were distributed in four treatments in a randomized block design. Treatments consisted of adding VM, MON or VM+MON to the supplement (CONT). Additive concentrations were defined to reach a dose of 40 to 45mg/100kg BW. The herbage allowance was not a limiting factor for the animals' intake. Supplement intake was lower than expected, with 33.0, 18.8 and 26.3mg per 100kg BW for VM, MON and VM+MON, respectively. Dry matter intake (DMI, mean=2.65% BW) and animal performance were not affected by the inclusion of additives. The average daily gain (ADG) was 0.561kg/animal day-1. The inclusion of additives in energetic mineral supplement does not affect the DMI and the ADG of grazing animals. The variability in supplement intake and daily dose intake of additives may have influenced the performance of the animals. Monensin inclusion presented the less expensive supplementation cost, due to reduction in supplement intake without changing weight gain.(AU)
Objetivou-se avaliar o efeito da inclusão dos aditivos virginiamicina (VM), monensina sódica (MON) e associação (VM+MON) no suplemento energético-mineral sobre o consumo e desempenho de bovinos manejados em pastagem de Urochloa Brizantha cv. Marandu. Foram utilizadas 40 novilhas Nelore com 24 meses de idade e peso corporal (PC) inicial médio de 251,5+16,6kg distribuídas em delineamento em blocos ao acaso com quatro tratamentos. Os tratamentos consistiam de suplemento energético-mineral (CONT) acrescido de VM, MON ou VM+MON. A oferta de forragem não limitou o consumo dos animais. O consumo dos aditivos foi de 0; 33,0; 18,8 e 26,3mg por 100kg de PC para CONT, VM, MON e VM+MON, respectivamente. O consumo de matéria seca e o desempenho dos animais não foram afetados pela inclusão dos aditivos. O ganho médio diário dos animais foi de 0,561kg dia -1 , sem diferença entre os tratamentos. A inclusão de aditivos no suplemento energético-mineral não alterou o CMS e o desempenho dos animais em pastejo. A variabilidade no consumo de suplemento e na dose ingerida dos aditivos pode ter influenciado o desempenho dos animais.(AU)
Assuntos
Animais , Feminino , Bovinos , Monensin/administração & dosagem , Aumento de Peso , Virginiamicina/administração & dosagem , Ionóforos , Aditivos Alimentares/administração & dosagemRESUMO
True green pigments in the animal kingdom are scarce and are almost invariably porphyrinoids. Endogenous porphyrins resulting from the breakdown of haem are usually known as "bile pigments". The pigmentation of intertidal Polychaeta has long gained attention due to its variety and vivid patterning that often seems incompatible with camouflage, as it occurs with Eulalia viridis, one of the few truly green Polychaeta. The present study combined UV and bright-field microscopy with HPLC to address the presence and distribution of pigments in several organs. The results showed two major types of porphyrin-like pigments, yellowish and greenish in colour, that are chiefly stored as intraplasmatic granules. Whereas the proboscis holds yellow pigments, the skin harbours both types in highly specialised cells. In their turn, oocytes and intestine have mostly green pigments. Despite some inter-individual variation, the pigments tend to be stable after prolonged storage at -20 °C, which has important implications for future studies. The results show that, in a foraging predator of the intertidal where melanins are circumscribed to lining the nervous system, porphyrinoid pigments have a key role in protection against UV light, in sensing and even as chemical defence against foulants and predators, which represents a remarkable adaptive feature.
Assuntos
Anelídeos/fisiologia , Organismos Aquáticos/fisiologia , Heme/metabolismo , Melaninas/metabolismo , Pigmentos Biológicos/fisiologia , Porfirinas/metabolismo , AnimaisRESUMO
Due to the role of Cytochrome P450, Family 1, Subfamily A (CYP1A) in the detoxification of many polycyclic aromatic hydrocarbons (PAHs), there has been an effort to characterise the gene and the products from its expression in organisms that are relevant for biomonitoring and toxicity testing procedures. Nonetheless, the existence of functional homologues in aquatic invertebrates is not entirely consensual, especially in bivalve molluscs, which pose as one of the most important models for aquatic toxicologists, especially mytilids. After isolation and sequencing of CYP1A-like mRNA from the Mediterranean mussel, Mytilus galloprovincialis, phylogenetics incorporating homologues from molluscs and other eumetazoans, vertebrates included, yielded notorious similarity to sequences belonging to the CYP2 Family. Altogether, the findings further indicate that CYP1A-like CYPs may be absent in bivalves, in lieu of Families CYP2, 3 and 4, suggesting caution when interpreting data from common biomarkers of exposure to aromatic hydrocarbons that have been developed for CYP1A activity and expression in higher deuterostomes.
Assuntos
Citocromo P-450 CYP1A1/genética , Família 2 do Citocromo P450/genética , Mytilus/enzimologia , Mytilus/genética , Animais , Sequência de Bases , Citocromo P-450 CYP1A1/metabolismo , Família 2 do Citocromo P450/metabolismo , Filogenia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Poluentes Químicos da Água/toxicidadeRESUMO
Eulalia viridis is a marine Polychaeta of the rocky intertidal that, despite its simple anatomy, is an active predator of much larger invertebrates, from which it extracts pieces of soft tissue through suction. This uncanny feeding strategy triggered the pursuit for the morphological mechanisms that enable adaptation to its environment. The evaluation of the worm anatomy and microanatomy, combining electron and optical microscopy, revealed a series of particular adaptations in the epidermis and in the proboscis (the heavily muscled eversible pharynx). Besides its function in feeding, the proboscis is the main sensory organ, being equipped with numerous sensorial papillae holding chemoreceptors. Additionally, the proboscis possesses tentacles that become exposed when the organ is everted. These provide fast release of mucus and toxins, from mucocytes and special serous cells, respectively (the latter involving both merocrine and apocrine processes), whenever contact with a prey occurs. In its turn, the epidermis provides protection by cuticle and mucus secretion and has a sensorial function that may be associated to the worm's uncommon green pigment cells. Eulalia viridis presents a series of elegant adaptive tools to cope with its environment that are evolutionarily designed to counterbalance its relatively simple body plan.
Assuntos
Adaptação Biológica , Epiderme/anatomia & histologia , Faringe/anatomia & histologia , Poliquetos/anatomia & histologia , AnimaisRESUMO
Motivated by biotechnological prospects, there is increasing evidence that we may just be scraping the tip of the iceberg of poisonous marine invertebrates, among which the Polychaeta are promising candidates for bioprospecting. Here we show that an inconspicuous phyllodocid uses toxins in its uncanny feeding strategy. The worm, a jawless active predator characterised by its bright green colour, preys on larger invertebrates (including conspecifics) by extracting tissue portions with its powerful proboscis through suction. The animal is even able to penetrate through the valves and plates of live molluscs and barnacles. Observations in situ and a series of experiments demonstrated that the worm compensates its simple anatomy with secretion of a novel toxin, or mixture of toxins, referred to by us as "phyllotoxins". These are carried by mucus and delivered via repeated contact with the tip of the proboscis until the prey is relaxed or immobilised (reversibly). Proteolytic action permeabilises material to toxins and softens tissue to enable extraction by suction. The findings show that toxins are a major ecological trait and therefore play a key role in evolutionary success and diversification of Polychaeta, demonstrating also that understanding adaptative features may become the best showcase for novel animal toxins.
Assuntos
Evolução Biológica , Bivalves/efeitos dos fármacos , Muco/metabolismo , Poliquetos/fisiologia , Comportamento Predatório/efeitos dos fármacos , Toxinas Biológicas/farmacologia , Animais , Ecologia , Comportamento Alimentar , Muco/química , Poliquetos/metabolismoRESUMO
Natural enemies are exposed to insecticide sprays for herbivorous species and may evolve field resistance to insecticides. Natural enemies selected for resistance in the field, however, are welcome for pest control. The susceptibility of 20 populations of Eriopis connexa from various crop ecosystems to λ-cyhalothrin was tested. Three bioassays were conducted: (i) topical treatment with lethal dose (LD)50 previously determined for populations considered standard for susceptibility (LD50S) and for resistance (LD50R) to λ-cyhalothrin at technical grade; (ii) dose-mortality assay to calculate the LD for populations exhibiting significant survival to the LD50R; and (iii) determination of survival when exposed to dried residues at field rates. Among the 20 tested populations, seven populations did not survive or survival rates were lower than 10% when treated with LD50R; three populations survived >20%, but lower than 50%; while ten populations exhibited equal or greater survival rates compared with the 50% expected survival for the LD50R. Thus, these ten populations were subjected to dose-mortality response, and the LD50 values varied from 0.046 to 5.44 µg a.i./insect with resistance ratio of 8.52- to 884.08-folds. Adults from these ten populations that were ranked as resistant according to the LD50R exhibited survival from 44.5 to 100% exposed to the lowest and from 38.8 to 100% exposed to the highest field rates of λ-cyhalothrin, respectively. Otherwise, the remaining ten populations ranked as susceptible according to the LD50R showed survival from 3.3 to 56% exposed to the lowest and from 0 to 17.7% exposed to the highest field rates of λ-cyhalothrin, respectively. Therefore, 50% of the tested E. connexa populations exhibited field-evolved resistance to λ-cyhalothrin and the use of a discriminatory LD50 for resistance matched the survival obtained when exposed to the insecticide field rates.
Assuntos
Evolução Biológica , Besouros , Nitrilas , Piretrinas , Animais , Resistência a Inseticidas , Dose Letal Mediana , Controle Biológico de VetoresRESUMO
Pneumocephalus is defined as the presence of air in any of the intracranial compartments. Its most frequent causes are trauma and cranial surgery. Clinical signs occur as a result of increased intracranial pressure and vary with the location and extent of the lesion. A case involving a seven-month-old female Saint Bernard, who suffered cranial trauma caused by a bite to the face at ten days of age and had presented with seizures and localized pain four months previously is reported. A computed tomography scan of the skull revealed a nasocephalic mass with low contrast enhancement, bone lysis, and hypodensity (-940 Hounsfield units) of the lateral and third ventricles, indicating intraventricular pneumocephalus. During surgery, a fragment of the mass was collected for histopathological examination, which demonstrated the presence of multifocal areas of necrosis. The computed tomography (CT) is a reliable method for the characterization of intracranial lesions and diagnosis of pneumocephalus, whose occurrence must be considered in pathological processes in which there is increased intracranial pressure and in patients undergoing certain surgical procedures and anesthetic specific, and CT is indicated as a monitoring tool for these patients.(AU)
Pneumoencéfalo é definido como a presença de gás em quaisquer dos compartimentos intracranianos e possui como causas mais frequentes o traumatismo e cirurgias cranianas. Os sinais clínicos ocorrem como consequência do aumento de pressão intracraniana e variam conforme o local e a extensão da lesão. Relata-se o caso de uma cadela de sete meses de idade, da raça São Bernardo, que sofreu trauma por mordedura em face, quatro meses antes, apresentando crises convulsivas e sensibilidade dolorosa local desde então. O exame tomográfico do crânio revelou massa nasoencefálica com baixa captação de contraste, lise óssea e hipodensidade (-940HU) dos ventrículos laterais e terceiro ventrículo encefálico, caracterizando pneumoencéfalo intraventricular. Foi realizada intervenção cirúrgica e coleta de fragmento da massa para exame histopatológico, que demonstrou existência de necrose multifocal. O exame de tomografia computadorizada (TC) é um método confiável para a caracterização de lesões intracranianas e diagnóstico de pneumoencéfalo, cuja ocorrência deve ser considerada em processos patológicos nos quais há aumento da pressão intracraniana e em pacientes submetidos a alguns procedimentos cirúrgicos e anestésicos específicos, sendo a TC indicada como ferramenta de monitoramento desses pacientes.(AU)
Assuntos
Animais , Cães , Encéfalo/cirurgia , Traumatismos Craniocerebrais/diagnóstico , Traumatismos Craniocerebrais/veterinária , Necrose , Tomografia Computadorizada por Raios X/veterináriaRESUMO
Pneumocephalus is defined as the presence of air in any of the intracranial compartments. Its most frequent causes are trauma and cranial surgery. Clinical signs occur as a result of increased intracranial pressure and vary with the location and extent of the lesion. A case involving a seven-month-old female Saint Bernard, who suffered cranial trauma caused by a bite to the face at ten days of age and had presented with seizures and localized pain four months previously is reported. A computed tomography scan of the skull revealed a nasocephalic mass with low contrast enhancement, bone lysis, and hypodensity (-940 Hounsfield units) of the lateral and third ventricles, indicating intraventricular pneumocephalus. During surgery, a fragment of the mass was collected for histopathological examination, which demonstrated the presence of multifocal areas of necrosis. The computed tomography (CT) is a reliable method for the characterization of intracranial lesions and diagnosis of pneumocephalus, whose occurrence must be considered in pathological processes in which there is increased intracranial pressure and in patients undergoing certain surgical procedures and anesthetic specific, and CT is indicated as a monitoring tool for these patients.
Pneumoencéfalo é definido como a presença de gás em quaisquer dos compartimentos intracranianos e possui como causas mais frequentes o traumatismo e cirurgias cranianas. Os sinais clínicos ocorrem como consequência do aumento de pressão intracraniana e variam conforme o local e a extensão da lesão. Relata-se o caso de uma cadela de sete meses de idade, da raça São Bernardo, que sofreu trauma por mordedura em face, quatro meses antes, apresentando crises convulsivas e sensibilidade dolorosa local desde então. O exame tomográfico do crânio revelou massa nasoencefálica com baixa captação de contraste, lise óssea e hipodensidade (-940HU) dos ventrículos laterais e terceiro ventrículo encefálico, caracterizando pneumoencéfalo intraventricular. Foi realizada intervenção cirúrgica e coleta de fragmento da massa para exame histopatológico, que demonstrou existência de necrose multifocal. O exame de tomografia computadorizada (TC) é um método confiável para a caracterização de lesões intracranianas e diagnóstico de pneumoencéfalo, cuja ocorrência deve ser considerada em processos patológicos nos quais há aumento da pressão intracraniana e em pacientes submetidos a alguns procedimentos cirúrgicos e anestésicos específicos, sendo a TC indicada como ferramenta de monitoramento desses pacientes.
Assuntos
Animais , Cães , Encéfalo/cirurgia , Necrose , Traumatismos Craniocerebrais/diagnóstico , Traumatismos Craniocerebrais/veterinária , Tomografia Computadorizada por Raios X/veterináriaRESUMO
The objective of this study was to assess the efficiency of a modification of the simulated individual best linear unbiased prediction (BLUPIS) procedure, which is used for the approximation of classic individuals (BLUPI) for selection between and within sugarcane families. A total of 110 full-sib families were employed in an experiment initiated in 2007 using a randomized block design with five replicates. The variable tons of stalks per hectare was measured from a plot containing 20 plants. The modified BLUPIS (BLUPISM) procedure showed a 0.98 correlation with BLUPI, thus demonstrating great efficiency in selecting individuals in sugarcane families during the initial phase of genetic breeding programs.
Assuntos
Cruzamento , Modelos Genéticos , Saccharum/genética , Seleção GenéticaRESUMO
Liver and gonad histopathology, biometric parameters and hepatic metal bioaccumulation were assessed monthly over a one-year period in common soles from the Basque continental shelf, in order to determine baseline levels and confounding factors within biomonitoring studies. Biometric parameters and hepatic metal bioaccumulation varied according to season and gender. Accordingly, hepatic histopathological traits presented seasonal variations related to the reproductive cycle. However, the hepatic histopathological index showed that seasonality and gender were not significant confounding factors. Conversely, the gonad histopathological index was modulated by season and gender. As for organ comparison, the liver endured more severe histopathological damage than the gonad. In brief, the sampling period and gender may not affect the estimation of hepatic histopathological indices for biomonitoring purposes. Nonetheless, due to different sensitivities to environmental 'noise' variables, the sampling period and gender differentiation should be thoroughly considered for the assessment of gonad histopathology, biometrics and metal bioaccumulation.
Assuntos
Exposição Ambiental , Monitoramento Ambiental/métodos , Linguados/metabolismo , Metais/metabolismo , Poluentes Químicos da Água/metabolismo , Fatores Etários , Animais , Feminino , Gônadas/metabolismo , Gônadas/patologia , Fígado/metabolismo , Fígado/patologia , Masculino , Medição de Risco , Estações do Ano , Fatores Sexuais , EspanhaRESUMO
The black oat (Avena strigosa Schreb) is commonly used for forage, soil cover, and green manure. Despite its importance, little improvement has been made to this species, leading to high levels of genotypic disuniformity within commercial cultivars. The objective of this study was to evaluate the efficiency of different doses of gamma rays [(60)Co] applied to black oat seeds on the increase of genetic variability of agronomic traits. We applied doses of 0, 10, 50, 100, and 200 Gy to the genotype ALPHA 94087 through exposure to [(60)Co]. Two experiments were conducted in the winter of 2008. The first aimed to test forage trait measurements such as plant height, dry matter yield, number of surviving tillers, and seedling stand. The second test assessed seed traits, such as yield and dormancy levels. Gamma irradiation seems not to increase seed yield in black oats, but it was effective in generating variability for the other traits. Tiller number and plant height are important selection traits to increase dry matter yield. Selection in advanced generations of mutant populations can increase the probability of identifying superior genotypes.
Assuntos
Avena/genética , Variação Genética/efeitos da radiação , Sementes/genética , Avena/efeitos da radiação , Raios gama , Fenótipo , Dormência de Plantas/efeitos da radiação , Locos de Características Quantitativas/genética , Plântula/efeitos da radiação , Sementes/efeitos da radiaçãoRESUMO
Superior inbred clones selected in S1 families can integrate an individual reciprocal recurrent selection program in sugarcane by eliminating the genetic load of the population and exploring superior hybrid combinations. Molecular markers can be used for reliable identification of the true selfing-derived clones in these S1 populations. The objective of this study was to confirm true self-fertilized individuals in sugarcane families using microsatellite markers aimed at the use of self-fertilized plants in an individual reciprocal recurrent selection strategy. Self-fertilized individuals from five cultivars were genotyped with eight simple sequence repeat (SSR) markers. The markers generated 62 polymorphic markers, with an average of seven polymorphic alleles across the cultivars tested. Three loci revealed highly informative bands and were used to assess the level of selfing in five S1 families. Selfing in these families ranged from 71.7 to 97.6%. The SSR loci provide a reliable and accurate method to identify S1 progenies in sugarcane crosses and can be used as a tool to assist selection strategies in sugarcane breeding programs.
Assuntos
Repetições de Microssatélites/genética , Saccharum/genética , Seleção Genética , Autofertilização/genética , Cruzamento/métodos , Cruzamentos Genéticos , DNA de Plantas/genética , Genótipo , Polinização/genética , Reação em Cadeia da Polimerase , Polimorfismo Genético , Reprodutibilidade dos Testes , Saccharum/classificação , Especificidade da EspécieRESUMO
The success of the development of new sugarcane varieties is associated with the ability to correctly select the genitor. The aim of this study was to evaluate the genetic diversity between 113 clones and sugarcane varieties using the Ward-modified location model procedure with added information about the coefficient of parentage and endogamy. In this study, data was used from 100 experiments that evaluated clones; the experimental phase was conducted in 70 places between the years 2002 and 2009 on the outlining in random blocks. According to the diversity analysis, 3 groups formed: G1, G2, and G3, which were composed of 58, 8, and 47 genotypes, respectively. The clones of groups G1 and G3 were the most outstanding. Thus, biparental crossbreeding involving clones and varieties of these 2 groups can efficiently obtain transgressive genotypes. Knowledge of the heterotypic groups indicated by the Ward-modified location model method, along with the parentage information, will make it a lot easier to define the desirable and undesirable crossbreeds for public and private breeding programs that develop sugarcane varieties.
Assuntos
Cruzamento/métodos , Variação Genética , Modelos Genéticos , Saccharum/genética , Brasil , Células Clonais/metabolismo , Genótipo , Fenótipo , Reprodutibilidade dos Testes , Saccharum/classificação , Saccharum/crescimento & desenvolvimentoRESUMO
We evaluated the genetic diversity of 77 clones of sugarcane used in crosses made by the Brazilian interuniversity network for the development of the sugar/energy sector (RIDESA) breeding program. Characterization of the genotypes was carried out at the ratoon stage, based on eight morphological traits and seven agronomic traits. Diversity analysis was carried out beginning with the Ward-Modified Location Model. The ideal number of groups was three. Groups 1, 2, and 3 were composed of 37, 21, and 19 accessions, respectively. Group 1 was formed entirely of commercial varieties (hybrids of advanced generations) and elite clones, with the exception of the old varieties 'Caiana Fita' and 'Cana Blanca' (hybrids of Saccharum officinarum). In general, group 2 had more divergent accessions regarding origin, including L60-14, NG57-6, TUC77-42, IN84-105 (hybrid of S. officinarum), and 28NG289 (species of S. robustum). Group 3 was formed entirely of commercial varieties and elite clones from the RIDESA program, with the exception of genotypes Co285 (India), Q124 (Australia) and VAT90-212 (unknown origin). The analysis based on the Ward-Modified Location Model procedure resulted in an adequate and clearly discriminating grouping of sugarcane accessions, allowing the use of all the available information about the genotypes, in a mix of continuous and categorical variables.
Assuntos
Cruzamento , Variação Genética , Saccharum/genética , Brasil , Análise por Conglomerados , Genótipo , Fenótipo , Especificidade da EspécieRESUMO
Estuarine sediments may be reservoirs of hydrophilic and hydrophobic pollutants, many of which are acknowledged genotoxicants, pro-mutagens and even potential carcinogens for humans. Still, studies aiming at narrowing the gap between ecological and human health risk of sediment-bound contaminant mixtures are scarce. Taking an impacted estuary as a case study (the Sado, SW Portugal), HepG2 (human hepatoma) cells were exposed in vitro for 48 h to extracts of sediments collected from two areas (urban/industrial and Triverine/agricultural), both contaminated by distinct mixtures of organic and inorganic toxicants, among which are found priority mutagens such as benzo[a]pyrene. Comparatively to a control test, extracts of sediments from both impacted areas produced deleterious effects in a dose-response manner. However, sediment extracts from the industrial area caused lower replication index plus higher cytotoxicity and genotoxicity (concerning total DNA strand breakage and clastogenesis), with emphasis on micronucleus induction. On the other hand, extracts from the rural area induced the highest oxidative damage to DNA, as revealed by the FPG (formamidopyrimidine-DNA glycosylase) enzyme in the Comet assay. Although the estuary, on its whole, has been classified as moderately contaminated, the results suggest that the sediments from the industrial area are significantly genotoxic and, furthermore, elicit permanent chromosome damage, thus potentially being more mutagenic than those from the rural area. The results are consistent with contamination by pro-mutagens like polycyclic aromatic hydrocarbons (PAHs), potentiated by metals. The sediments from the agriculture-influenced area likely owe their genotoxic effects to metals and other toxicants, probably pesticides and fertilizers, and able to induce reactive oxygen species without the formation of DNA strand breakage. The findings suggest that the mixtures of contaminants present in the assayed sediments are genotoxic to HepG2 cells, ultimately providing a useful approach to hazard identification and an effective line-of-evidence in the environmental monitoring of anthropogenically-impacted coastal ecosystems.
Assuntos
Monitoramento Ambiental/métodos , Estuários , Sedimentos Geológicos/química , Mutagênicos/toxicidade , Poluentes Químicos da Água/toxicidade , Linhagem Celular Tumoral , Ensaio Cometa , Dano ao DNA , Humanos , Estresse Oxidativo , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , PortugalRESUMO
Complex toxicant mixtures present in estuarine sediments often render contaminant screening unfeasible and compromise determining causation. HepG2 cells were subjected to bioassays with sediment extracts obtained with a series of progressively polar solvents plus a crude extract. The sediments were collected from an impacted area of an estuary otherwise regarded as pristine, whose stressors result mostly from aquaculture effluents and hydrodynamic shifts that enhance particle deposition. Compared to a reference scenario, the most polar extracts yielded highest cytotoxicity while higher genotoxicity (including oxidative damage) was elicited by non-polar solvents. While the former caused effects similar to those expected from biocides, the latter triggered effects compatible with known pro-mutagens like PAHs, even though the overall levels of toxicants were considered of low risk. The results indicate that the approach may constitute an effective line-of-evidence to infer on the predominant set of hazardous contaminants present in complex environmental mixtures.
Assuntos
Bioensaio , Monitoramento Ambiental/métodos , Estuários , Sedimentos Geológicos/química , Mutagênicos/toxicidade , Poluentes Químicos da Água/toxicidade , Linhagem Celular Tumoral , Dano ao DNA , Humanos , Hidrocarbonetos Policíclicos Aromáticos/toxicidadeRESUMO
For the purpose of biomonitoring, species that combine ecological and commercial importance may provide a link between ecological and human health risk. The common cuttlefish, Sepia officinalis, holds both characteristics in south-western Europe, albeit remaining unsurveyed in ecotoxicological studies. Cuttlefish collected from an impacted estuary in SW Portugal and a reference location off the coast were analysed for a battery of biomarker responses in the digestive gland and gills. The contrast to reference animals revealed that biomarker responses, especially those related to oxidative stress, were consistent with sediment contamination by PAHs, even in a situation that combines complex toxicant mixtures, moderate levels of contamination and high ecotoxicological diversity. However, environmental parameters related to the differences between shore and estuarine habitats should not be overruled. Also, digestive gland metallothionein retained significant specificity to metals even though previous studies in the area with clams and fish failed to trigger a conclusive response. The highest net differences in biomarker responses were detected in the gills, likely indicating higher sensitivity to environmental stressors. Still, the digestive gland responses were overall the most consistent with sediment contamination and effectively differentiated between estuarine industrial- and rural-impacted sites. The results indicate that S. officinalis may be a candidate to meet the European Union's requirements for efficient biomonitoring programmes, with the additional importance of being cosmopolitan, abundant, commercially valuable and combining the molluscan biology that has been granting bivalves their high value for biomonitoring with foraging behaviour, thus better able to reflect anthropogenic stressors impacting a wider area than sedentary organisms. Nevertheless, further investigations in unpolluted sites are needed to better evaluate the background levels of biomarker responses in the species.
Assuntos
Monitoramento Ambiental/métodos , Trato Gastrointestinal/metabolismo , Brânquias/metabolismo , Sepia/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Biomarcadores/metabolismo , Estuários , Cromatografia Gasosa-Espectrometria de Massas , Sedimentos Geológicos/análise , Humanos , Portugal , Medição de Risco/métodos , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Poluentes Químicos da Água/análiseRESUMO
A histopathological screening was performed on juvenile Senegalese soles exposed to environmentally realistic concentrations of waterborne Cd (0.5, 5 and 10 µg L(-1)) for 28 days. The severity and dissemination of histopathological changes were variable and limited to the kidney, liver, spleen, gills and skin goblet cells. Contradicting available literature that refers the liver as the most affected organ upon acute exposure and the kidney following chronic exposure, the liver was the most impacted organ (even at the lowest concentration), in a trend that could relate to the duration of exposure and Cd concentration. The most noticeable hepatic alterations related to inflammation, although hepatocellular alterations like lipidosis and eosinophilic foci also occurred. The trunk kidney of exposed fish endured moderate inflammation, apoptosis and necrosis, however, without a clear time-dependent effect. The spleen of fish subjected to the highest concentrations revealed diffuse necrotic foci accompanied by melanomacrophage intrusion. The gills, albeit the most important apical uptake organ of dissolved toxicants, sustained only moderate damage, from epithelial hyperplasia and pavement cell detachment to the potentially more severe chloride cell alterations. In the skin, an increase in goblet cell size occurred, most notoriously correlated to Cd concentration at earlier stages of exposure. The results show that a metal-naïve juvenile fish can endure deleterious effects when exposed to low, ecologically relevant, concentrations of a common toxic metal and that the pattern of Cd-induced histopathological alterations can be complex and linked to organ-specific responses and metal translocation within the organism.