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1.
Br J Surg ; 2021 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-34165555

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.

2.
J Anat ; 233(5): 567-579, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30073651

RESUMO

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 , Animais
3.
Bull Entomol Res ; 108(3): 380-387, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28920566

RESUMO

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 Vetores
4.
Genet Mol Res ; 15(1)2016 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-26909904

RESUMO

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 Genética
5.
Genet Mol Res ; 13(4): 8962-70, 2014 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-25366787

RESUMO

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 Espécie
6.
Genet Mol Res ; 13(1): 1650-60, 2014 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-24535897

RESUMO

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 Espécie
7.
Genet Mol Res ; 13(4): 10332-40, 2014 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-25501245

RESUMO

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 radiação
8.
Genet Mol Res ; 13(4): 9005-18, 2014 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-25366791

RESUMO

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 & desenvolvimento
9.
Ecotoxicology ; 22(10): 1538-54, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24142132

RESUMO

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/análise
10.
Arch Environ Contam Toxicol ; 64(1): 97-109, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23052360

RESUMO

Transitional waterbodies, such as estuaries, are highly diversified environments with respect to ecology, geophysics, and nature of anthropogenic impacts. This spatial heterogeneity may pose important constraints when developing monitoring programmes for aquatic pollution. The present study compared three distinct coastal ecosystems located in Southern Portugal (subjected to different anthropogenic stressors), namely, two estuaries and a coastal lagoon, through the characterisation of sediment contamination and a biomarker approach to an important commercial clam (Ruditapes decussatus) obtained from local fishing grounds. The results showed high heterogeneity of sediment contamination for both estuaries and a marked distinction between industrially and agriculturally influenced areas as well as between natural and artificialized sites. Hydrodynamics and oceanic influence (in essence dictating sediment type) play a major role in environmental quality. Environmental heterogeneity constituted an important confounding factor for biomarker analysis in the clams' digestive glands since the animals appeared to respond to their immediate surroundings' characteristics rather than the geographical area where they were collected from, despite the relative distance to pollution hot spots. Still, oxidative stress biomarkers (lipid peroxidation and catalase activity) could correlate with each other and to both organic and metallic contamination, whereas metallothionein-like protein induction failed to correlate to any class of sediment toxicants (albeit metals being the most representative pollutants) and appeared to be strongly affected (unlike the previous) by clam size and probably other unknown internal and external variables, among which contaminant interactions should play a major role.


Assuntos
Bivalves/metabolismo , Ecossistema , Monitoramento Ambiental/métodos , Poluentes Químicos da Água/toxicidade , Animais , Biomarcadores/metabolismo , Ecotoxicologia , Peroxidação de Lipídeos/efeitos dos fármacos , Metalotioneína/metabolismo , Portugal , Poluentes Químicos da Água/metabolismo
11.
Fish Physiol Biochem ; 39(2): 143-58, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22752339

RESUMO

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.


Assuntos
Apoptose/efeitos dos fármacos , Cádmio/toxicidade , Linguados , Poluentes Químicos da Água/toxicidade , Animais , Relação Dose-Resposta a Droga , Brânquias/efeitos dos fármacos , Brânquias/patologia , Células Caliciformes/efeitos dos fármacos , Células Caliciformes/patologia , Técnicas Histológicas/veterinária , Marcação In Situ das Extremidades Cortadas/veterinária , Rim/efeitos dos fármacos , Rim/patologia , Fígado/efeitos dos fármacos , Fígado/patologia , Senegal , Baço/efeitos dos fármacos , Baço/patologia , Estatísticas não Paramétricas
12.
Ecotoxicology ; 18(8): 1011-7, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19621256

RESUMO

The toxicity of bleached Kraft pulp mill effluents (BKME) is usually attributed to chemical compounds which are produced and released throughout various stages of pulp and paper production. The main objective of the present work was to detect sub-lethal responses of goldfish (Carassius auratus) to secondary treated BKME which was treated with Rhizopus oryzae. A total of 96 carps (C. auratus; 11 +/- 3 g) were exposed to different concentrations of the post-treated effluent (0, 1, 10, 25, 50, and 100%), in 28 days semi-static tests. Several biomarkers were then evaluated to assess the toxicological effects: induction of CYP1A (metabolic processes of organic compounds in liver), change in steroid profiles (11-Ketotestosterone, 17beta-estradiol), histopathology of liver and gonads and somatic indices (GSI, HSI) for endocrine disruption and other physiological disturbances. The most significant results show an induction of CYP1A in both sexes and a decrease of 17beta-estradiol concentrations in females. Histopathological changes such as liver tissue degeneration were observed in fish exposed to 50 and 100% of the BKME. Although the BKME was biologically treated there are some chemical compounds in the effluent that are capable to affect fish physiology, however, a clear evidence for endocrine disruption was not found.


Assuntos
Resíduos Industriais/efeitos adversos , Fígado/efeitos dos fármacos , Rhizopus/metabolismo , Poluentes Químicos da Água/toxicidade , Animais , Biomarcadores , Citocromo P-450 CYP1A1/efeitos dos fármacos , Citocromo P-450 CYP1A1/metabolismo , Indução Enzimática/efeitos dos fármacos , Feminino , Carpa Dourada/metabolismo , Hormônios Esteroides Gonadais/metabolismo , Fígado/metabolismo , Masculino , Papel
13.
Aquat Toxicol ; 214: 105260, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31336222

RESUMO

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/toxicidade
14.
Sci Rep ; 9(1): 12930, 2019 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-31506557

RESUMO

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 , Animais
16.
Nephron Clin Pract ; 109(2): c95-9, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18596378

RESUMO

BACKGROUND: Anemia with low serum erythropoietin (EPO) is common in Portuguese transthyretin V30M amyloid polyneuropathy (FAP). Low EPO production can be observed before clinical disease. Renal amyloidosis is observed in FAP, mainly in the medulla. Renal manifestations correlate with glomerular and vascular involvement, but not with tubulointerstitial deposition. To evaluate the potential role of renal amyloid deposits in the genesis of the EPO defect in FAP, we analyzed the renal biopsies of 12 patients (5 males, 7 females, aged from 29 to 54 years) with a clinical evolution varying from 3 to 12 (mean 5.4 +/- 2.8) years. METHODS: Formalin-fixed, paraffin-embedded sections of renal biopsies were stained by Congo red. Amyloid deposits were assessed by a semiquantitative method based on the percentage of amyloid deposition in each renal structure. Hemoglobin, creatinine, urea, EPO and proteinuria were concomitantly evaluated and correlated with the pathological findings. RESULTS: Renal amyloid deposits were observed in all biopsies analyzed, independently of the neuropathy score. Low serum EPO levels were not related with either the amount of amyloid deposition or the renal clinical manifestations. CONCLUSION: Impairment of EPO production in FAP is not directly related to renal amyloid deposits and more studies are needed to clarify this question.


Assuntos
Neuropatias Amiloides Familiares/metabolismo , Amiloide/metabolismo , Angiopatia Amiloide Cerebral/metabolismo , Eritropoetina/metabolismo , Rim/metabolismo , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
17.
Micron ; 39(6): 690-7, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18036825

RESUMO

Several aspects of the modelling of the energy loss near edge structure (ELNES) using the Wien2k code and the Telnes program are discussed in this paper. A case study with ground state, partial and full core-hole calculations of wurtzite AlN was performed and the results were compared with experimental transmission electron microscopy data. The best agreement with the experimental observations was obtained for the full core-hole case. Changes in the ELNES spectra for various core-hole charges are explained by investigating the site and symmetry projected density of states. Directionally resolved N K-edge ELNES of AlN are discussed and the magic angle beta approximately 2.5mrad is identified which is in a good agreement with other theoretical predictions. Finally, preliminary results on a compositional study of Al(x)Ga(1-x)N are explored.


Assuntos
Compostos de Alumínio/química , Gálio/química , Microscopia Eletrônica de Transmissão/métodos , Elétrons , Nanoestruturas/química
18.
Ecotoxicol Environ Saf ; 71(1): 117-24, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17617458

RESUMO

Metallothionein (MT) in the liver of gilthead seabreams (Sparus aurata L., 1758) exposed to Sado estuary (Portugal) sediments was quantified to assess the MT induction potential as a biomarker of sediment-based contamination by copper (Cu), cadmium (Cd), lead (Pb) and arsenic (As). Sediments were collected from two control sites and four sites with different levels of contamination. Sediment Cu, Cd, Pb, As, total organic matter (TOM) and fine fraction (FF) levels were determined. Generalized linear models (GLM) allowed integration of sediment parameters with liver Cu, Cd, Pb, As and MT concentrations. Although sediment metal levels were lower than expected, we relate MT with liver Cd and also with interactions between liver and sediment Cu and between liver Cu and TOM. We suggest integrating biomarkers and environmental parameters using statistical models such as GLM as a more sensitive and reliable technique for sediment risk assessment than traditional isolated biomarker approaches.


Assuntos
Sedimentos Geológicos/química , Fígado/efeitos dos fármacos , Fígado/metabolismo , Metalotioneína/metabolismo , Metais/toxicidade , Dourada/metabolismo , Animais , Fígado/química , Metais/análise , Metais/metabolismo , Portugal , Rios , Poluentes Químicos da Água/química , Poluentes Químicos da Água/toxicidade
19.
Sci Rep ; 8(1): 7635, 2018 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-29769587

RESUMO

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/metabolismo
20.
Clin Cancer Res ; 6(4): 1557-62, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10778989

RESUMO

Topoisomerase I (Topo I) is overexpressed in cancer colon tissues compared with normal colon tissues. Several anti-Topo I inhibitors are already successfully used in the clinic. We illustrate here the antiproliferative activity of a new class of Topo I inhibitors, i.e., E-ring-modified camptothecins with enhanced lactone stability (L. Lesueur-Ginot et al., Cancer Res., 59: 2939-2943, 1999). Forty-three human colon cancers were obtained from surgical resection and maintained under organotypical culture conditions for 48 h. Cell proliferation was assessed in these ex vivo tumor tissue cultures by tritiated thymidine autoradiography. As a validation of the methodology, we first analyzed in our model the antiproliferative activity of two clinically active topoisomerase II (Topo II) inhibitors, Adriamycin and etoposide, which are not active for colon cancers; and three Topo I inhibitors, camptothecin (CPT) and two clinically active compounds (especially for colon cancers), i.e., topotecan and the active metabolite of irinothecan, SN-38. We then compared the antiproliferative activity of CPT, topotecan, and SN-38 against those of two investigational E-ring-modified camptothecins, i.e., BN80245 and BN80915. Three concentrations (1, 10, and 100 nM) were studied for each compound. The results indicate that the three Topo I inhibitors used as references, i.e., CPT, irinothecan, and SN-38, were much more active than the two Topo II inhibitors, i.e., Adriamycin and etoposide, with SN-38 being the most efficient. The two investigational compounds BN80245 and BN80915 exerted higher antiproliferative activity than the three anti-Topo I reference compounds, with the highest activity observed for BN80915.


Assuntos
Antineoplásicos/farmacologia , Camptotecina/análogos & derivados , Neoplasias do Colo/tratamento farmacológico , Inibidores Enzimáticos/farmacologia , Inibidores da Topoisomerase I , Biópsia , Camptotecina/farmacologia , Divisão Celular/efeitos dos fármacos , Colo/efeitos dos fármacos , Colo/patologia , Neoplasias do Colo/patologia , Técnicas de Cultura , DNA Topoisomerases Tipo I/metabolismo , Relação Dose-Resposta a Droga , Doxorrubicina/farmacologia , Etoposídeo/farmacologia , Humanos , Irinotecano , Timidina/metabolismo , Topotecan/farmacologia , Trítio , Células Tumorais Cultivadas
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