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1.
Mar Environ Res ; 165: 105243, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33476978

RESUMEN

The marine environment is being increasingly modified by the construction of artificial structures, the impacts of which may be mitigated through eco-engineering. To date, eco-engineering has predominantly aimed to increase biodiversity, but enhancing other ecological functions is arguably of equal importance for artificial structures. Here, we manipulated complexity through habitat structure (flat, and 2.5 cm, 5 cm deep vertical and 5 cm deep horizontal crevices) and seeding with the native oyster (Saccostrea glomerata, unseeded and seeded) on concrete tiles (0.25 m × 0.25 m) affixed to seawalls to investigate whether complexity (both orientation and depth of crevices) influences particle removal rates by suspension feeders and colonisation by different functional groups, and whether there are any ecological trade-offs between these functions. After 12 months, complex seeded tiles generally supported a greater abundance of suspension feeding taxa and had higher particle removal rates than flat tiles or unseeded tiles. The richness and diversity of taxa also increased with complexity. The effect of seeding was, however, generally weaker on tiles with complex habitat structure. However, the orientation of habitat complexity and the depth of the crevices did not influence particle removal rates or colonising taxa. Colonisation by non-native taxa was low compared to total taxa richness. We did not detect negative ecological trade-offs between increased particle removal rates and diversity and abundance of key functional groups. Our results suggest that the addition of complexity to marine artificial structures could potentially be used to enhance both biodiversity and particle removal rates. Consequently, complexity should be incorporated into future eco-engineering projects to provide a range of ecological functions in urbanised estuaries.


Asunto(s)
Ecosistema , Ostreidae , Animales , Biodiversidad , Estuarios
2.
Mar Pollut Bull ; 155: 111129, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32469765

RESUMEN

Ten global harbours were assessed for sediment quality by quantifying the magnitude of anthropogenic change and ecological risk. Anthropogenic change (enrichment) was high for Derwent River and Sydney estuary, moderate for Santander Harbour, Rio de Janeiro and Dublin Port, slight for Hong Kong, minimal for Darwin. All 10 enrichment indices used showed similar results. Derwent River sediment was rated at high ecological risk, followed by Sydney and Santander estuaries with moderate risk. Auckland and Darwin sediments exhibited minimal ecological risk and sediment in the remaining harbours (Dublin, Hong Kong, Ravenna, Ria de Vigo and Rio de Janeiro) were assessed at slight ecological risk. The extraordinary variety of environments and types/quantities/qualities of data investigated resulted in as much a critique and development of methodology, as an assessment of human impact, including unique techniques for elemental normalisation and contaminant classification. Recommendations for an improved technical framework for sediment quality assessment are provided.


Asunto(s)
Metales Pesados/análisis , Contaminantes Químicos del Agua/análisis , Monitoreo del Ambiente , Estuarios , Sedimentos Geológicos , Hong Kong , Humanos , Medición de Riesgo , Ríos
3.
Sci Total Environ ; 658: 1293-1305, 2019 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-30677991

RESUMEN

Marine harbours are the focus of a diverse range of activities and subject to multiple anthropogenically induced pressures. Support for environmental management options aimed at improving degraded harbours depends on understanding the factors which influence people's perceptions of harbour environments. We used an online survey, across 12 harbours, to assess sources of variation people's perceptions of harbour health and ecological engineering. We tested the hypotheses: 1) people living near impacted harbours would consider their environment to be more unhealthy and degraded, be more concerned about the environment and supportive of and willing to pay for ecological engineering relative to those living by less impacted harbours, and 2) people with greater connectedness to the harbour would be more concerned about and have greater perceived knowledge of the environment, and be more supportive of, knowledgeable about and willing to pay for ecological engineering, than those with less connectedness. Across twelve locations, the levels of degradation and modification by artificial structures were lower and the concern and knowledge about the environment and ecological engineering were greater in the six Australasian and American than the six European and Asian harbours surveyed. We found that people's perception of harbours as healthy or degraded, but not their concern for the environment, reflected the degree to which harbours were impacted. There was a positive relationship between the percentage of shoreline modified and the extent of support for and people's willingness to pay indirect costs for ecological engineering. At the individual level, measures of connectedness to the harbour environment were good predictors of concern for and perceived knowledge about the environment but not support for and perceived knowledge about ecological engineering. To make informed decisions, it is important that people are empowered with sufficient knowledge of the environmental issues facing their harbour and ecological engineering options.

4.
J Environ Manage ; 230: 488-496, 2019 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-30340122

RESUMEN

Ecological engineering principles are increasingly being applied to develop multifunctional artificial structures or rehabilitated habitats in coastal areas. Ecological engineering initiatives are primarily driven by marine scientists and coastal managers, but often the views of key user groups, which can strongly influence the success of projects, are not considered. We used an online survey and participatory mapping exercise to investigate differences in priority goals, sites and attitudes towards ecological engineering between marine scientists and coastal managers as compared to other stakeholders. The surveys were conducted across three Australian cities that varied in their level of urbanisation and environmental pressures. We tested the hypotheses that, relative to other stakeholders, marine scientists and coastal managers will: 1) be more supportive of ecological engineering; 2) be more likely to agree that enhancement of biodiversity and remediation of pollution are key priorities for ecological engineering; and 3) identify different priority areas and infrastructure or degraded habitats for ecological engineering. We also tested the hypothesis that 4) perceptions of ecological engineering would vary among locations, due to environmental and socio-economic differences. In all three harbours, marine scientists and coastal managers were more supportive of ecological engineering than other users. There was also greater support for ecological engineering in Sydney and Melbourne than Hobart. Most people identified transport infrastructure, in busy transport hubs (i.e. Circular Quay in Sydney, the Port in Melbourne and the Waterfront in Hobart) as priorities for ecological engineering, irrespective of their stakeholder group or location. There were, however, significant differences among locations in what people perceive as the key priorities for ecological engineering (i.e. biodiversity in Sydney and Melbourne vs. pollution in Hobart). Greater consideration of these location-specific differences is essential for effective management of artificial structures and rehabilitated habitats in urban embayments.


Asunto(s)
Biodiversidad , Australia , Ecosistema , Ingeniería , Contaminación Ambiental , Urbanización
5.
Food Chem Toxicol ; 121: 573-582, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30253247

RESUMEN

We analyzed a comprehensive set of contaminants in MON810 and NK603 genetically modified (GM) maize, and their non-GM counterparts, used in a rat feeding study (the GMO90 + project). Both the maize grains and the manufactured pellets were characterized. Only minor differences in contaminant levels between GM and corresponding non-GM harvests were evidenced. Fumonisin and deoxynivalenol mycotoxins were the pollutants present in the highest amounts, with concentrations that were however largely below acceptance reference values. Our data reporting slightly lower levels of fumonisin in MON810 compared to its non-GM counterpart corroborate the lower susceptibility of insect resistant Bt maize to fumonisin-producing fungi. Traces of glyphosate (0.016 mg/kg) were evidenced in grains from NK603 treated crops. Regarding the pellets, analysis of more than 650 potentially toxic substances revealed low amounts of various mycotoxins, pesticides and heavy metals. Concentrations of contaminants quantified in the pellets were however far below the maximum level of residues values set by regulatory agencies, and no substantial differences in contaminants between GM and non-GM pellets were observed. Moreover, when comparing the contamination status of grains and pellets, we demonstrate yet again that characterizing the grains is actually not sufficient to foresee the quality of the produced pellets.


Asunto(s)
Alimentación Animal/análisis , Proteínas Bacterianas/genética , Endotoxinas/genética , Contaminación de Alimentos/análisis , Fumonisinas/química , Proteínas Hemolisinas/genética , Plantas Modificadas Genéticamente , Zea mays/genética , Animales , Toxinas de Bacillus thuringiensis , Dieta , Alimentos Modificados Genéticamente , Ratas , Pruebas de Toxicidad
6.
Arch Toxicol ; 92(9): 2703-2748, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-30132047

RESUMEN

Isoflavones are secondary plant constituents of certain foods and feeds such as soy, linseeds, and red clover. Furthermore, isoflavone-containing preparations are marketed as food supplements and so-called dietary food for special medical purposes to alleviate health complaints of peri- and postmenopausal women. Based on the bioactivity of isoflavones, especially their hormonal properties, there is an ongoing discussion regarding their potential adverse effects on human health. This review evaluates and summarises the evidence from interventional and observational studies addressing potential unintended effects of isoflavones on the female breast in healthy women as well as in breast cancer patients and on the thyroid hormone system. In addition, evidence from animal and in vitro studies considered relevant in this context was taken into account along with their strengths and limitations. Key factors influencing the biological effects of isoflavones, e.g., bioavailability, plasma and tissue concentrations, metabolism, temporality (pre- vs. postmenopausal women), and duration of isoflavone exposure, were also addressed. Final conclusions on the safety of isoflavones are guided by the aim of precautionary consumer protection.


Asunto(s)
Mama/efectos de los fármacos , Isoflavonas/efectos adversos , Isoflavonas/farmacología , Hormonas Tiroideas/metabolismo , Animales , Mama/metabolismo , Densidad de la Mama/efectos de los fármacos , Neoplasias de la Mama/inducido químicamente , Neoplasias de la Mama/epidemiología , Neoplasias de la Mama/prevención & control , Ensayos Clínicos como Asunto , Suplementos Dietéticos , Femenino , Humanos , Isoflavonas/farmacocinética , Glycine max/química , Distribución Tisular
7.
Toxicology ; 385: 28-37, 2017 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-28454766

RESUMEN

Consumers are exposed to low concentrations of a variety of pesticide residues in or on food. Some of them might interfere with the endocrine system. While each individual active substance has been extensively tested for toxicity and safety, potential combination effects possibly resulting from combined exposure to different pesticides have seldomly been tested so far, especially in vivo. Since the adrenal gland is a key endocrine organ, we investigated if and how substances of a group of fungicides presumed to interfere with the biosynthesis of steroid hormones affect this organ when applied individually and in combination in a broad dose range. A 28-day feeding study was conducted in Wistar rats by using three (tri)azole fungicides considered to potentially affect the endocrine system (cyproconazole, epoxiconazole and prochloraz) individually at five dose levels, ranging from 0.9ppm to 2400ppm, and in combination at three dose levels. The parameters analysed included classical toxicology (pathology, histopathology, clinical chemistry) and molecular toxicology endpoints (gene expression arrays and quantitative real time PCR e.g. of Star, HSD3ß, Cyp11a1, Cyp11b1, Cyp11b2, Cyp 21, ApoE), as well as hormone analysis. A dose-dependent decrease in the adrenal gland weight of rats treated with epoxiconazole alone, which was accompanied by an atrophy of the adrenal gland as well as by an increase in the serum cholesterol level and which only became statistically significant at the top dose levels, was observed. These effects were attenuated in the combination experiments, although the same epoxiconazole concentration was used.


Asunto(s)
Glándulas Suprarrenales/efectos de los fármacos , Azoles/toxicidad , Fungicidas Industriales/toxicidad , 3-Hidroxiesteroide Deshidrogenasas/genética , Glándulas Suprarrenales/metabolismo , Glándulas Suprarrenales/patología , Aldosterona/sangre , Animales , Apolipoproteínas E/genética , Colesterol/sangre , Corticosterona/sangre , Sistema Enzimático del Citocromo P-450/genética , Interacciones Farmacológicas , Expresión Génica/efectos de los fármacos , Masculino , Nivel sin Efectos Adversos Observados , Tamaño de los Órganos/efectos de los fármacos , Fosfoproteínas/genética , Progesterona/sangre , Ratas Wistar
8.
Sci Rep ; 6: 36260, 2016 11 08.
Artículo en Inglés | MEDLINE | ID: mdl-27824083

RESUMEN

Coral cover on reefs is declining globally due to coastal development, overfishing and climate change. Reefs isolated from direct human influence can recover from natural acute disturbances, but little is known about long term recovery of reefs experiencing chronic human disturbances. Here we investigate responses to acute bleaching disturbances on turbid reefs off Singapore, at two depths over a period of 27 years. Coral cover declined and there were marked changes in coral and benthic community structure during the first decade of monitoring at both depths. At shallower reef crest sites (3-4 m), benthic community structure recovered towards pre-disturbance states within a decade. In contrast, there was a net decline in coral cover and continuing shifts in community structure at deeper reef slope sites (6-7 m). There was no evidence of phase shifts to macroalgal dominance but coral habitats at deeper sites were replaced by unstable substrata such as fine sediments and rubble. The persistence of coral dominance at chronically disturbed shallow sites is likely due to an abundance of coral taxa which are tolerant to environmental stress. In addition, high turbidity may interact antagonistically with other disturbances to reduce the impact of thermal stress and limit macroalgal growth rates.


Asunto(s)
Antozoos/fisiología , Monitoreo del Ambiente/métodos , Animales , Antozoos/microbiología , Cambio Climático , Arrecifes de Coral , Resistencia a la Enfermedad , Dinámica Poblacional , Singapur
9.
Sci Rep ; 6: 20717, 2016 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-26876092

RESUMEN

While many studies of coral bleaching report on broad, regional scale responses, fewer examine variation in susceptibility among coral taxa and changes in community structure, before, during and after bleaching on individual reefs. Here we report in detail on the response to bleaching by a coral community on a highly disturbed reef site south of mainland Singapore before, during and after a major thermal anomaly in 2010. To estimate the capacity for resistance to thermal stress, we report on: a) overall bleaching severity during and after the event, b) differences in bleaching susceptibility among taxa during the event, and c) changes in coral community structure one year before and after bleaching. Approximately two thirds of colonies bleached, however, post-bleaching recovery was quite rapid and, importantly, coral taxa that are usually highly susceptible were relatively unaffected. Although total coral cover declined, there was no significant change in coral taxonomic community structure before and after bleaching. Several factors may have contributed to the overall high resistance of corals at this site including Symbiodinium affiliation, turbidity and heterotrophy. Our results suggest that, despite experiencing chronic anthropogenic disturbances, turbid shallow reef communities may be remarkably resilient to acute thermal stress.


Asunto(s)
Antozoos/fisiología , Resistencia a la Enfermedad/fisiología , Animales , Arrecifes de Coral , Ecosistema , Calor , Océano Índico
10.
Sci Rep ; 5: 10803, 2015 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-26042834

RESUMEN

The majority of marine invertebrates produce dispersive larvae which, in order to complete their life cycles, must attach and metamorphose into benthic forms. This process, collectively referred to as settlement, is often guided by habitat-specific cues. While the sources of such cues are well known, the links between their biological activity, chemical identity, presence and quantification in situ are largely missing. Previous work on coral larval settlement in vitro has shown widespread induction by crustose coralline algae (CCA) and in particular their associated bacteria. However, we found that bacterial biofilms on CCA did not initiate ecologically realistic settlement responses in larvae of 11 hard coral species from Australia, Guam, Singapore and Japan. We instead found that algal chemical cues induce identical behavioral responses of larvae as per live CCA. We identified two classes of CCA cell wall-associated compounds--glycoglycerolipids and polysaccharides--as the main constituents of settlement inducing fractions. These algae-derived fractions induce settlement and metamorphosis at equivalent concentrations as present in CCA, both in small scale laboratory assays and under flow-through conditions, suggesting their ability to act in an ecologically relevant fashion to steer larval settlement of corals. Both compound classes were readily detected in natural samples.


Asunto(s)
Antozoos/fisiología , Animales , Bacterias , Señales (Psicología) , Larva
11.
Vet Comp Oncol ; 12(2): 149-59, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22882564

RESUMEN

Vineatrol(®) 30 is a grapevine-shoot extract, which contains resveratrol as well as considerable amounts of so-called resveratrol oligomers such as hopeaphenol and r2-viniferin. In this study, we analysed whether the two above-mentioned resveratrol oligomers were able to inhibit the growth of the canine glioblastoma cell line D-GBM and the canine histiocytic sarcoma cell line DH82, compared their potency to inhibit tumour cell growth with that of resveratrol and determined whether the induction of apoptosis via caspase 9 and 3/7 activation underlies the tumour cell growth-inhibiting effect of hopeaphenol and r2-viniferin. Vineatrol(®) 30, resveratrol, hopeaphenol and r2-viniferin inhibited the growth of D-GBM and DH82 cells in a concentration-dependent manner, whereby hopeaphenol and r2-viniferin were more potent than resveratrol itself in inhibiting the growth of the canine tumour cell lines. Moreover, the anti-proliferative effect of both resveratrol oligomers in D-GBM cells is based on their capacity to induce caspase 9 and 3/7 activation.


Asunto(s)
Perros , Glioblastoma/metabolismo , Sarcoma Histiocítico/metabolismo , Polifenoles/química , Estilbenos/química , Estilbenos/farmacología , Animales , Antineoplásicos/química , Antineoplásicos/farmacología , Línea Celular Tumoral , Estructura Molecular , Fenoles , Polifenoles/farmacología , Resveratrol
12.
Clin Nephrol ; 76(5): 354-7, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22000554

RESUMEN

OBJECTIVE: There is no standardized definition of stone free after renal stone surgery. The lack of standardization prompted a review of the current urologic literature, to assess the definitions of stone free status, and how imaging is used to determine stone free status. METHODS: A literature search on PubMed for the MeSH terms for percutaneous nephrolithotomy (PCNL), ureteroscopy with lithotripsy, shock wave lithotripsy (SWL), and laser lithotripsy, published in English between January 2007 and January 2010 was performed. Case reports, articles not evaluating stone free outcomes, and review articles were excluded. Articles were evaluated for the treatment modality, definition of stone free status, and the imaging modality employed to determine stone free status. RESULTS: This search yielded 417 articles of which 249 met inclusion criteria. Stone free was defined in 169 articles (68%). The most common definition of stone free was "no stones" (47%), but a total of seven different definitions were encountered. The most common treatment modality was PCNL (47%), followed by SWL (33%), and URS (13%). The most common detection modality was KUB alone (28%), the second most common being KUB and US combined (22%). CONCLUSIONS: Nearly one-third of articles evaluating surgical management of urinary calculi do not define stone free status; when stone free is defined, there is wide variation as to that definition. Furthermore, vast differences exist in the type of imaging used to define stone free status. The urologic community should standardize the reporting of stone free outcomes in the urologic literature.


Asunto(s)
Cálculos Renales/cirugía , Supervivencia sin Enfermedad , Humanos , Litotricia/métodos , Nefrostomía Percutánea , Ureteroscopía
13.
Phys Rev Lett ; 104(14): 142301, 2010 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-20481933

RESUMEN

This Letter presents the first measurement of event-by-event fluctuations of the elliptic flow parameter v(2) in Au+Au collisions at square root(s(NN))=200 GeV as a function of collision centrality. The relative nonstatistical fluctuations of the v(2) parameter are found to be approximately 40%. The results, including contributions from event-by-event elliptic flow fluctuations and from azimuthal correlations that are unrelated to the reaction plane (nonflow correlations), establish an upper limit on the magnitude of underlying elliptic flow fluctuations. This limit is consistent with predictions based on spatial fluctuations of the participating nucleons in the initial nuclear overlap region. These results provide important constraints on models of the initial state and hydrodynamic evolution of relativistic heavy ion collisions.

14.
Phys Rev Lett ; 104(6): 062301, 2010 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-20366815

RESUMEN

A measurement of two-particle correlations with a high transverse momentum trigger particle (p(T)(trig) > 2.5 GeV/c) is presented for Au+Au collisions at square root(s(NN)) = 200 GeV over the uniquely broad longitudinal acceptance of the PHOBOS detector (-4 < Delta eta < 2). A broadening of the away-side azimuthal correlation compared to elementary collisions is observed at all Delta eta. As in p+p collisions, the near side is characterized by a peak of correlated partners at small angle relative to the trigger particle. However, in central Au+Au collisions an additional correlation extended in Delta eta and known as the "ridge" is found to reach at least |Delta eta| approximately = 4. The ridge yield is largely independent of Delta eta over the measured range, and it decreases towards more peripheral collisions. For the chosen (p(T)(trig) cut, the ridge yield is consistent with zero for events with less than roughly 100 participating nucleons.

15.
Phys Rev Lett ; 102(14): 142301, 2009 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-19392428

RESUMEN

We present the first measurements of the pseudorapidity distribution of primary charged particles in Cu+Cu collisions as a function of collision centrality and energy, sqrt[s_{NN}]=22.4, 62.4, and 200 GeV, over a wide range of pseudorapidity, using the PHOBOS detector. A comparison of Cu+Cu and Au+Au results shows that the total number of produced charged particles and the rough shape (height and width) of the pseudorapidity distributions are determined by the number of nucleon participants. More detailed studies reveal that a more precise matching of the shape of the Cu+Cu and Au+Au pseudorapidity distributions over the full range of pseudorapidity occurs for the same N{part}/2A rather than the same N_{part}. In other words, it is the collision geometry rather than just the number of nucleon participants that drives the detailed shape of the pseudorapidity distribution and its centrality dependence at RHIC energies.

16.
J Exp Biol ; 210(Pt 18): 3228-35, 2007 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-17766300

RESUMEN

Some marine invertebrate larvae expand the range of settlement cues to which they will respond as they age. How do relatively simple larvae achieve such complex changes in behaviour? Larvae of the Australian sea urchin Holopneustes purpurascens settle and metamorphose specifically in response to a settlement cue, dissolved histamine, produced by the host alga Delisea pulchra. Older H. purpurascens larvae appear to accept a wider range of host algae, which contain far less histamine than D. pulchra, than newly competent larvae. We tested the hypothesis that older H. purpurascens larvae accept a greater range of host algae by metamorphosing in response to lower concentrations of histamine. We compared the response of newly competent and older larvae to a range of histamine concentrations in settlement assays. Larval age strongly affected the minimum concentration of histamine that induced metamorphosis in H. purpurascens, with older larvae responding to lower concentrations of histamine than newly competent larvae. Older larvae were more sensitive to lower concentrations of histamine yet still maintained a stringent requirement for exposure to histamine in order to metamorphose. In addition, older larvae metamorphosed after shorter exposure periods to histamine than did younger larvae. By using histamine concentration as a proxy for specific habitat cues, H. purpurascens larvae appear to expand their range of settlement preferences with age by simply changing their sensitivity to a single settlement cue. Overall, our results show that marine invertebrate larvae can exhibit surprisingly complex changes in behaviour via simple changes in their response to a single cue.


Asunto(s)
Conducta Animal/fisiología , Histamina/farmacología , Erizos de Mar/fisiología , Envejecimiento , Animales , Quimiotaxis , Relación Dosis-Respuesta a Droga , Eucariontes/metabolismo , Histamina/metabolismo , Larva , Metamorfosis Biológica/efectos de los fármacos
17.
Phys Rev Lett ; 98(24): 242302, 2007 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-17677957

RESUMEN

This Letter presents measurements of the elliptic flow of charged particles as a function of pseudorapidity and centrality from Cu-Cu collisions at 62.4 and 200 GeV using the PHOBOS detector at the Relativistic Heavy Ion Collider. The elliptic flow in Cu-Cu collisions is found to be significant even for the most central events. For comparison with the Au-Au results, it is found that the detailed way in which the collision geometry (eccentricity) is estimated is of critical importance when scaling out system-size effects. A new form of eccentricity, called the participant eccentricity, is introduced which yields a scaled elliptic flow in the Cu-Cu system that has the same relative magnitude and qualitative features as that in the Au-Au system.

18.
Cell Biol Toxicol ; 23(3): 153-61, 2007 May.
Artículo en Inglés | MEDLINE | ID: mdl-17122891

RESUMEN

In the present study we show that repeated exposure of the rat intestinal epithelial cell line IEC-18 to 2-hydroxyamino-1-methyl-6-phenylimidazo[4,5-b]pyridine (N-OH-PhIP), from a toxicological point of view the most relevant phase-1 metabolite of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP, the main heterocyclic aromatic amine present in processed meat), led to the selection of N-OH-PhIP-resistant IEC-18 cells. This phenomenon was accompanied by a fivefold increase in total glutathione S-transferase (GST) activity, measured with the broad-spectrum substrate 1-chloro-2,4-dinitrobenzene, in the N-OH-PhIP-resistant IEC-18 cells. Furthermore, a Western blotting analysis revealed that the expression of GST subunits A1, A3, A4, M1 and P1 was enhanced in the N-OH-PhIP-resistant IEC-18 cells.


Asunto(s)
Glutatión Transferasa/metabolismo , Imidazoles/toxicidad , Mutágenos/toxicidad , Piridinas/toxicidad , Animales , Secuencia de Bases , Línea Celular , Resistencia a Medicamentos , Células Epiteliales/efectos de los fármacos , Células Epiteliales/metabolismo , Expresión Génica , Glutatión Transferasa/química , Glutatión Transferasa/genética , Íleon/efectos de los fármacos , Íleon/metabolismo , Imidazoles/metabolismo , Carne/análisis , Carne/toxicidad , Mutágenos/metabolismo , Piridinas/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ratas
19.
Prog Mol Subcell Biol ; 42: 55-86, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16805438

RESUMEN

The red alga Delisea pulchra has been a model organism for understanding the ecological role of secondary metabolites as natural antifoulants. Furanones are produced by the plant and delivered to the surface at a concentration where they regulate bacterial colonisation and the settlement of epibiota. This biological understanding has led to the application of furanones as inhibitors of bacterial- and macro-fouling. Furanones inhibit bacterial colonisation and biofilm development through interference with a key bacterial quorum-sensing pathway, the acylated homoserine lactone regulatory system in Gram-negative bacteria. They also interfere with the alternative AI-2 signalling system in Gram-negative and Gram-positive bacteria. Synthetic programs have developed a library of more than 200 furanone and furanone-analogues including surface attached-furanones. These furanone analogues are potent anti-infectives and inhibit pathogenic phenotypes in Gram-negative and Gram-positive bacteria as demonstrated in-vitro using gene microarrays, and in-vivo using mouse models. Additionally, furanones inhibit the expression of bacterial exo-enzymes that actively degrade components of the immune system thereby enhancing the immune response. Surface-attached furanones immobilised on catheters also inhibit bacterial attachment and retain activity for extended periods. Furanones are strong deterrents of the settlement and growth of macrofouling organisms and as such have potential application as a marine antifouling technology. Laboratory antifouling assays have been used to identify effective and safe furanone-analogues while field trials of furanones incorporated into coatings and polymers demonstrate efficacies similar to commercial biocides. Further development is required to control the release of compounds from suitable carriers to extend coating/polymer lifespans. This review summarises the extensive work on furanones focusing on their natural and applied antifouling activities.


Asunto(s)
Antiinfecciosos/química , Antiinfecciosos/farmacología , Furanos/química , Furanos/farmacología , Antiinfecciosos/aislamiento & purificación , Bacterias/efectos de los fármacos , Bacterias/patogenicidad , Biopelículas/efectos de los fármacos , Ecosistema , Furanos/aislamiento & purificación , Modelos Biológicos , Estructura Molecular , Rhodophyta/metabolismo , Rhodophyta/microbiología , Transducción de Señal/efectos de los fármacos
20.
Phys Rev Lett ; 96(21): 212301, 2006 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-16803231

RESUMEN

We present transverse momentum distributions of charged hadrons produced in Cu + Cu collisions at square root of SNN = 62.4 and 200 GeV. The spectra are measured for transverse momenta of 0.25 < pT < 5.0 GeV/c at square root of SNN = 62.4 GeV and 0.25 < pT < 7.0 GeV/c at square root of SNN = 200 GeV, in a pseudorapidity range of 0.2 < eta < 1.4. The nuclear modification factor R(AA) is calculated relative to p + p data at both collision energies as a function of collision centrality. At a given collision energy and fractional cross section, R(AA) is observed to be systematically larger in Cu + Cu collisions compared to Au + Au. However, for the same number of participating nucleons, R(AA) is essentially the same in both systems over the measured range of pT, in spite of the significantly different geometries of the Cu + Cu and Au + Au systems.

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