Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
Más filtros

País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Ecotoxicol Environ Saf ; 113: 248-58, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25521339

RESUMEN

Produced water is the main discharge stream from oil and gas production. For offshore activities this water is usually discharged to the marine environment. Produced water contains traces of hydrocarbons such as polycyclic aromatic hydrocarbons as well as alkylphenols, which are relatively resistant to biodegradation and have been reported to cause adverse effects to marine organisms in laboratory studies. For management of produced water, risk-based tools have been developed using toxicity data for mainly non-Arctic species. Reliable risk assessment approaches for Arctic environments are requested to manage potential impacts of produced water associated with increased oil and gas activities in Arctic regions. In order to assess the applicability of existing risk tools for Arctic areas, basic knowledge on the sensitivity of Arctic species has to be developed. In the present study, acute and chronic toxicity of artificial produced water for 6 Arctic and 6 temperate species was experimentally tested and evaluated. The hazardous concentrations affecting 5% and 50% of the species were calculated from species sensitivity distribution curves. Hazardous concentrations were compared to elucidate whether temperate toxicity data used in risk assessment are sufficiently representative for Arctic species. From the study it can be concluded that hazardous concentration derived from individual species' toxicity data of temperate and Arctic species are comparable. However, the manner in which Arctic and non-Arctic populations and communities respond to exposure levels above established thresholds remains to be investigated. Hence, responses at higher levels of biological organization should be studied to reveal potential differences in sensitivities to produced water between Arctic and non-Arctic ecosystems.


Asunto(s)
Clima Frío , Peces , Invertebrados , Pruebas de Toxicidad Aguda , Pruebas de Toxicidad Crónica , Aguas Residuales/toxicidad , Animales , Regiones Árticas , Copépodos , Crangonidae , Crassostrea , Diatomeas , Ecosistema , Ambiente , Peces Planos , Gadiformes , Mytilus edulis , Perciformes , Contaminación por Petróleo , Fenoles/toxicidad , Hidrocarburos Policíclicos Aromáticos/toxicidad , Medición de Riesgo , Agua
2.
J Toxicol Environ Health A ; 77(9-11): 557-73, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24754392

RESUMEN

Offshore oil and gas drilling processes generate operational discharges such as produced water (PW), a complex mixture of seawater with polycyclic aromatic hydrocarbons (PAH) and alkylphenols (AP). Some of these compounds may interact with the endocrine system of marine organisms and alter reproductive functions. In this study, polar cod were exposed for up to 28 d to a mixture of PAH, alkylated PAH, and AP simulating the composition of North Sea PW, at low and high concentrations (1:2000 and 1:1000 dilution of the original concentrate, respectively). Potential adverse effects of PW on polar cod physiology were investigated through biomarkers of biotransformation (hepatic ethoxyresorufin O-deethylase [EROD] activity and bile PAH metabolites), endocrine disruption (plasma vitellogenin [VTG] levels and sex steroid concentrations), and gonad histology. Plasma sexual steroid levels in fish were not markedly affected by PW exposure, while higher plasma VTG concentrations were measured in females exposed to the high PW treatment for 7 and 28 d. In males exposed to the higher PW concentration, inhibition of spermatogenesis was observed after 28 d in addition to increase of melano-macrophage occurrence in testis. Females exposed to the high PW treatment for 21 d showed a significant increase of atresia incidence. Finally, a significant decrease in oocyte number was observed in high PW exposed female ovaries after 28 d of exposure.


Asunto(s)
Exposición a Riesgos Ambientales/análisis , Gadiformes/fisiología , Reproducción/efectos de los fármacos , Contaminantes Químicos del Agua/toxicidad , Animales , Bilis/metabolismo , Biomarcadores/sangre , Citocromo P-450 CYP1A1/metabolismo , Disruptores Endocrinos/toxicidad , Sistema Endocrino/efectos de los fármacos , Sistema Endocrino/metabolismo , Femenino , Hígado/efectos de los fármacos , Hígado/metabolismo , Masculino , Mar del Norte , Ovario/efectos de los fármacos , Ovario/metabolismo , Hidrocarburos Policíclicos Aromáticos/toxicidad , Agua de Mar/química , Esteroides/sangre , Testículo/efectos de los fármacos , Testículo/metabolismo , Vitelogeninas/sangre
3.
J Toxicol Environ Health A ; 74(7-9): 555-68, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21391098

RESUMEN

The past decades of monitoring discharges from oil and gas industry have revealed that although there are indications of adverse effects in tissues of aquatic organisms, little is known about their temporal development. Furthermore, observations in wild-caught individuals have not been clearly reproduced in laboratory studies or caging studies, and vice versa, and the results are therefore not easily interpretable. There is clearly a need for exposure studies designed for monitoring the development of effect markers in individual fish over chronic periods to low contaminant levels. Through repetitive nondestructive sampling, the progression of effects may be monitored in individuals, significantly reducing the number of fish needed in exposure studies. A laboratory exposure study was designed to be able to monitor selected parameters in individual Atlantic cod (Gadus morhua). Passive integrated transponders in combination with visible implant elastomers were used to study individual fish during the exposure period (44 wk). Fish were measured (weight and length) and a blood sample was taken for analysis of hematocrit, DNA damage (micronucleus), and oxidative stress (total oxyradical scavenging capacity) at up to seven time points. There were no apparent adverse effects of treatments on the health of experimental fish, frequency of micronucleated erythrocytes, or oxidative stress in whole blood. It is possible that the time scale was not sufficient for development and detection of parameters included here or that red blood cells may not be a suitable matrix for the selected analyses. Future studies need to include other parameters in blood to investigate their sensitivity to low-concentration exposures.


Asunto(s)
Monitoreo del Ambiente/métodos , Gadus morhua/metabolismo , Residuos Industriales/análisis , Contaminantes Químicos del Agua/toxicidad , Animales , Biomarcadores/sangre , Biomarcadores/metabolismo , Peso Corporal/efectos de los fármacos , Daño del ADN , Disruptores Endocrinos/análisis , Disruptores Endocrinos/toxicidad , Eritrocitos/efectos de los fármacos , Industria Procesadora y de Extracción , Femenino , Gadus morhua/sangre , Masculino , Estrés Oxidativo , Petróleo , Fenoles/análisis , Fenoles/toxicidad , Hidrocarburos Policíclicos Aromáticos/análisis , Hidrocarburos Policíclicos Aromáticos/toxicidad , Agua de Mar/química , Contaminantes Químicos del Agua/análisis
4.
Ecotoxicol Environ Saf ; 74(3): 355-65, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21040973

RESUMEN

The present study aimed to assess the ecological situation in the Pechora River Basin (east part of Sub-Arctic Russia) using histopathologies of fish and to relate fish health to environmental quality. This paper reports histopathological alterations of fish kidney, liver, and gills and their association with chemical contamination of the Pechora River. A variety of histopathological changes was found. Differences between studied species and sites of the Pechora River with regard to the type, prevalence, and severity of lesions were studied. The types of the lesions indicated that fish respond to both direct toxicant effects of contaminated water and sediment, and secondary stress effects caused by factors such as parasitism. The structural modifications found in this study are a result of acute damage associated with short-term exposure as much as chronic response due to long-term pollution.


Asunto(s)
Cyprinidae/fisiología , Ríos/química , Salmonidae/fisiología , Contaminantes Químicos del Agua/toxicidad , Animales , Biodiversidad , Cyprinidae/metabolismo , Monitoreo del Ambiente , Branquias/efectos de los fármacos , Branquias/metabolismo , Branquias/patología , Riñón/efectos de los fármacos , Riñón/metabolismo , Riñón/patología , Hígado/efectos de los fármacos , Hígado/metabolismo , Hígado/patología , Salmonidae/metabolismo , Contaminantes Químicos del Agua/análisis
5.
Mar Environ Res ; 140: 468-477, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30220411

RESUMEN

The present study investigates the potential long-term physiological effects on maturing polar cod (Boreogadus saida), an Arctic key species, after an acute exposure (48 h) to environmentally realistic concentrations of either mechanically dispersed oil (MDO), chemically dispersed oil (CDO) or burned oil residues (BO) (N = 58-60 per treatment). Following exposure, fish were monitored in a common tank supplied with clean water for a seven-month period coinciding with the period of reproductive development. Females exposed to BO residues were more frequently found in an earlier phase of gonadal maturation compared to unexposed females while no effects of different oil spill response (OSR) actions were seen in the reproductive development of males. Mechanically and chemically dispersed oil induced a transient short-term reduction in growth in the first week post-exposure. Overall, no significant long-term effects of exposure were seen in growth or mortality. Ultimately, this study provides information for the assessment of population consequences of different OSR actions as part of a net environmental benefit analysis.


Asunto(s)
Gadiformes/fisiología , Petróleo/toxicidad , Pruebas de Toxicidad Aguda , Contaminantes Químicos del Agua/toxicidad , Animales , Citocromo P-450 CYP1A1 , Femenino , Masculino , Contaminación por Petróleo , Hidrocarburos Policíclicos Aromáticos/toxicidad
6.
Environ Sci Pollut Res Int ; 23(21): 21441-21450, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27507142

RESUMEN

This study evaluated the sensitivity of the wolfish Anarhichas denticulatus exposed to crude oil, comparing the effects of mechanically dispersed versus chemically dispersed oil using sub-lethal endpoints. To test the toxicity of this controversial technique, two experiments involving exposure of the organisms for 48 h were conducted. The first experiment assessed the effects of oil exposure on biomarker responses. The second experiment monitored the growth of juveniles over 5 weeks after exposure. Overall, this study demonstrated that polycyclic aromatic hydrocarbon (PAH) biliary metabolites, ethoxyresorufin-O-deethylase (EROD), and acetylcholinesterase (AChE) are appropriate biomarkers to assess exposure of A. denticulatus. Growth rate, both in length and weight, was significantly higher in control compared to oil exposure treatments. The lack of differences between chemically and mechanically dispersed oils in biomarker response and growth suggests that dispersant application is no more toxic than the natural oil dispersion. The results indicate the potential for population-level effects resulting from exposure to oil.


Asunto(s)
Perciformes/crecimiento & desarrollo , Petróleo/toxicidad , Hidrocarburos Policíclicos Aromáticos/toxicidad , Contaminantes Químicos del Agua/toxicidad , Acetilcolinesterasa/metabolismo , Animales , Biomarcadores/metabolismo , Citocromo P-450 CYP1A1/metabolismo , Hígado/efectos de los fármacos , Hígado/enzimología , Perciformes/metabolismo , Petróleo/análisis , Hidrocarburos Policíclicos Aromáticos/análisis , Agua de Mar/química , Pruebas de Toxicidad , Contaminantes Químicos del Agua/análisis
7.
Aquat Toxicol ; 75(4): 354-73, 2005 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-16242792

RESUMEN

Enzymatic defenses involved in protection from oxygen radical damage were determined in gills and mantle of Bathymodiolus azoricus collected from three contrasting Mid-Atlantic Ridge (MAR) hydrothermal vent fields (Menez-Gwen, Lucky Strike and Rainbow). The activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidases (GPx) (total and Se-dependent), and levels of total oxyradical scavenging capacity (TOSC), metallothioneins (MT) and lipid peroxidation (LPO) were determined in B. azoricus tissues and the impact of metal concentrations on these antioxidant systems and lipid peroxidation assessed. SOD, CAT, TOSC, MTs and LPO levels were higher in B. azoricus gills while glutathione peroxidases (total and Se-dependent) were higher in the mantle, and with the exception of CAT, were of the same order of magnitude as in other molluscs. TOSC levels from Menez-Gwen indicate that the vent environment at this site is less stressful and the formation of ROS in mussels is effectively counteracted by the antioxidant defense system. TOSC depletion indicates an elevated ROS production in molluscs at the other two vent sites. Cytosolic SOD, GPx and LPO were more relevant at Lucky Strike (Bairro Alto) where levels of essential (Cu and Zn) and toxic metals (Cd and Ag) were highest in the organisms. CAT activity and LPO were predominant at the Rainbow vent site, where an excess of Fe in mussel tissues and in vent fluids (the highest of all three vent sites) may have contributed to increased LPO. Therefore, three distinct pathways for antioxidant enzyme systems and LPO based on environmental metal speciation of MAR vent fields are proposed for Bathymodiolus gills. At Menez-Gwen, TOSC towards peroxyl and hydroxyl radicals and peroxynitrite are predominant, while at Lucky Strike cytosolic SOD activity and GPx are the main antioxidant mechanisms. Finally at Rainbow, catalase and lipid peroxidation are dominant, suggesting that resistance of mussels to metal toxicity at these vent fields decreases in the sequence Menez-Gwen > Lucky Strike and Rainbow.


Asunto(s)
Bivalvos/enzimología , Peroxidación de Lípido/fisiología , Metales Pesados/toxicidad , Agua de Mar/química , Análisis de Varianza , Animales , Océano Atlántico , Bivalvos/fisiología , Catalasa/metabolismo , Depuradores de Radicales Libres/metabolismo , Geografía , Branquias/enzimología , Glutatión Peroxidasa/metabolismo , Peroxidación de Lípido/efectos de los fármacos , Metalotioneína/metabolismo , Análisis de Componente Principal , Superóxido Dismutasa/metabolismo
8.
Aquat Toxicol ; 61(1-2): 1-13, 2002 Nov 13.
Artículo en Inglés | MEDLINE | ID: mdl-12297367

RESUMEN

Increasing industrial activity in the European Arctic has raised concerns of the potential anthropogenic impact of chemicals on this polar marine ecosystem. For the past 20 years or so, biomarkers have been developed to provide early-warning signals of detrimental impacts of chemicals on the marine ecosystem, however, most biomarker methods have been established for organisms living in temperate rather than polar waters. Little is known about biomarker responses in organisms living within the temperature range of -1.88 to +5 degrees C. In this study, established biomarkers from temperate studies were tested on the Arctic spider crab Hyas araneus to validate their use in polar ecosystems. H. araneus is common in Svalbard fjord (Norway), although it is a temperate water species occurring from northern Spain to Svalbard at depths from 10 to 1200 m. In this paper, the effects of oil were investigated at 2 degrees C via two routes: (i) injection and (ii) contaminated sediment. After 2 weeks of exposure, heart rate, oxygen consumption and total oxyradical scavenging capacity (TOSC) were measured in the same individuals. In both methods of contaminant exposure, heart rate showed a significant increase compared with the control (P < 0.0001, n = 7); mean heart rate values (+/- S.D.) of H. araneus were 49.06 (+/- 13.72), 57.56 (+/- 7.28) and 63.30 (+/- 6.57) beats per minute in control, injected and sediment-treated groups, respectively. Respiration of H. araneus was not affected significantly by either oil treatment (P > 0.05), but two individuals (n = 8) showed a marked increase in oxygen uptake in the sediment-exposed group. The basal oxygen consumption of control H. araneus was lower (0.025 mg O(2) g wet wt.(-1) h(-1)) than reported for H. araneus living in temperate water. Although TOSC of H. araneus was not affected significantly by either exposure treatment (P > 0.05) the mean TOSC value in the sediment-exposed group was lower than the control, indicating some saturation of the oxyradical scavenging system. Results indicate that although low temperature appears to be the main factor reducing the bioavailability of polycyclic-aromatic hydrocarbons, the relatively low metabolic rate of Arctic H. araneus is also implicated in decreased uptake and metabolism of oil compounds into reactive oxygen species (ROS).


Asunto(s)
Braquiuros/fisiología , Exposición a Riesgos Ambientales , Consumo de Oxígeno , Hidrocarburos Policíclicos Aromáticos/efectos adversos , Contaminantes Químicos del Agua/efectos adversos , Animales , Biomarcadores/análisis , Radicales Libres , Sedimentos Geológicos/química , Frecuencia Cardíaca , Respiración
9.
Sci Total Environ ; 308(1-3): 221-34, 2003 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-12738215

RESUMEN

Expanding industrial activity (notably oil and gas exploration) in the Arctic requires assessment of the potential impact of chemicals on marine organisms living in seawater at low temperature. The bivalve Mya truncata is common in Svalbard fjord (Norway) where it experiences low temperature throughout the year. To measure the impact of polycyclic aromatic hydrocarbons (PAH) on M. truncata, the responses of three biomarkers [total oxyradical scavenging capacity-assay (TOSC), plasma membrane stability of haemocytes and respiration rates] were investigated from bivalves exposed to sediment contaminated with a PAH mixture (crude oil). After two weeks of exposure to the contaminated sediment, TOSC showed no change. The high TOSC value (4010+/-1339 unit mg(-1) protein) of Mya truncata (control group) is thought to protect biomolecules with a low turnover rate efficiently in a low food availability environment. In the exposed bivalves, the haemocyte cellular membranes were significantly destabilised compared with controls (P<0.05). Respiration rate of control and PAH-exposed individuals (0.055+/-0.020 mg O(2) dw(-1) h(-1)) was similar and relatively low as is typical for polar bivalves, reflecting a strategy to minimise energy expenditure to cope with 9 months of starvation. Bioaccumulation of PAH by M. truncata was also low, due probably to a combination of low metabolic rate and reduced solubility of the oil compounds at low temperature. Data indicated an uptake of mainly low molecular weight compounds (two and three ring molecules). A good correlation of logBAF(lipid) (bioaccumulation factor) and logK(ow) (octanol/water partitioning coefficient) was shown (r(2)=0.87). Tissue sensitivity and/or functional differences (digestive gland vs. haemocytes), PAH uptake route (dietary vs. gills), the low metabolic rate of M. truncata and the low environmental temperature (reducing the bioavailability of PAH) are factors that help explain these findings.


Asunto(s)
Bivalvos , Exposición a Riesgos Ambientales , Hidrocarburos Policíclicos Aromáticos/farmacocinética , Animales , Regiones Árticas , Disponibilidad Biológica , Biomarcadores/análisis , Monitoreo del Ambiente , Sedimentos Geológicos , Peso Molecular , Petróleo , Hidrocarburos Policíclicos Aromáticos/efectos adversos , Hidrocarburos Policíclicos Aromáticos/análisis , Solubilidad , Temperatura , Distribución Tisular
10.
Mar Environ Res ; 58(2-5): 615-8, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15178088

RESUMEN

Environmental concern for the deep-sea ecosystem is increasing as contaminants, originating from anthropogenic activities, have been detected in deep-sea biota. However, little is known on the xenobiotics metabolising capability of deep-sea fauna. In this study, the deep-sea amphipod Eurythenes gryllus was selected as sentinel species to measure the total oxyradical scavenging capacity (TOSC). Individuals of E. gryllus were sampled at 2000 m depth in the Arctic Ocean. The TOSC assay was measured on the cytosolic fraction and the soluble fraction (3 kDa) of the digestive gland and on the cell-free haemolymph toward peroxyl, hydroxyl and peroxynitrite radicals according to the method of Winston et al. [Free Radical Biology and Medicine 24 (3) (1998) 480] and Regoli and Winston [Toxicology and Applied Pharmacology 156 (1999) 96]. These results provide the first baseline data set for total antioxidant capacity in a deep-sea amphipod.


Asunto(s)
Anfípodos/metabolismo , Monitoreo del Ambiente , Depuradores de Radicales Libres/metabolismo , Animales , Regiones Árticas , Hemolinfa/metabolismo , Radical Hidroxilo/metabolismo , Hígado/metabolismo , Océanos y Mares , Peróxidos/metabolismo , Ácido Peroxinitroso/metabolismo
11.
Mar Environ Res ; 58(2-5): 781-5, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15178113

RESUMEN

The effect of temperature on the heart rate (fH) of Carcinus maenas exposed to a sublethal nominal concentration (0.5 mg l(-1)) of copper is reported. Adult, intermoult males (4 cm carapace width) were collected from Stavanger Fjord (Norway) in August (seawater TEMPERATURE=17 degrees C) and maintained in the laboratory (fed ad libitum) at 5, 15 and 25 degrees C for 7 days. Following this holding period, crabs were exposed to waterborne copper at the same temperature. After 3 days of exposure, individual fH was measured using the non-invasive Computer Aided Physiological MONitoring system (CAPMON) method. Copper-exposed individuals demonstrated significantly increased fH compared with controls at 5 and 25 degrees C (P<0.01). It is inferred that physiological function in C. maenas may be more vulnerable to copper contamination at seasonal temperature extremes (5 and 25 degrees C) than at the 'standard' test temperature (15 degrees C). Additionally, cardiac arrest observed at 5 degrees C is interpreted as a physiological response to limit copper uptake while the erratic fH in the 25 degrees C group reflected enhanced copper toxicity.


Asunto(s)
Braquiuros/efectos de los fármacos , Cobre/toxicidad , Frecuencia Cardíaca/efectos de los fármacos , Temperatura , Animales , Braquiuros/fisiología , Paro Cardíaco/inducido químicamente , Frecuencia Cardíaca/fisiología , Masculino , Noruega , Agua de Mar
12.
Mar Environ Res ; 50(1-5): 325-9, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11460712

RESUMEN

Expanding industrial activities in the Arctic require an urgent assessment of the toxicity of chemicals at low temperatures. Organisms acclimatized to low temperature exhibit specific adaptations. For example, the amount of unsaturated lipids is increased to maintain the fluidity of the cell membranes. It has been hypothesized that such temperature-induced alterations in membrane lipid composition may affect the stability of lysosomal and cell membranes in the common mussel, Mytilus edulis, an organism exposed to seasonal temperature extremes. As mussels may be exposed to petroleum compounds along industrialized coastlines, we tested the combined effects of exposure to low temperature and the petroleum compound, phenanthrene, on haemocyte membrane stability. Test animals, acclimated to either 0 or 10 degrees C, were exposed to phenanthrene (0 = control or 500 micrograms l-1) and haemocytes were examined using the neutral red retention assay (lysosomal stability) and a fluorescence assay (cell membrane stability). At 0 degree C, lysosomal and cell membranes from uncontaminated mussels were destabilized compared with 10 degrees C (P = 0.0005). No significant effects (P > 0.05) of phenanthrene were detected at either temperature. Possible mechanisms underlying membrane destabilization include a weaker physical resistance of the membrane due to a higher amount of unsaturated lipids, a potentially higher level of reactive oxygen radicals at low temperature and the higher susceptibility of unsaturated lipids to oxidative stress. More work is required to better understand the consequences of this membrane destabilization at low temperature on the susceptibility of the organism to pollutants.


Asunto(s)
Adaptación Fisiológica , Bivalvos/fisiología , Frío , Hemocitos/fisiología , Fenantrenos/toxicidad , Contaminantes Químicos del Agua/toxicidad , Animales , Bivalvos/efectos de los fármacos , Membrana Celular/efectos de los fármacos , Membrana Celular/fisiología , Colorantes Fluorescentes , Hemocitos/efectos de los fármacos , Membranas Intracelulares/efectos de los fármacos , Membranas Intracelulares/fisiología , Lisosomas/efectos de los fármacos , Lisosomas/fisiología , Permeabilidad
13.
Mar Environ Res ; 54(3-5): 425-30, 2002.
Artículo en Inglés | MEDLINE | ID: mdl-12408597

RESUMEN

Industrial activities, notably oil and gas industries, are expanding in the Arctic. Most of the biomarkers were developed using temperate organisms living at temperatures above 10 degrees C. Little is known about the biomarker responses of organisms living between -1.88 and 5 degrees C. Therefore, assessment of the toxicity of chemicals to cold-water adapted species is required. In this study, the Arctic scallop, Chlamys islandicus, was selected as a key species for bio-monitoring because of wide distribution in Arctic waters and its commercial value. Test animals, stored in seawater at 2 degrees C, were injected with benzo(a)pyrene (diluted in cod liver oil 5 mg ml(-1)) in the adductor muscle every 24 h for four days giving a final dose of 0, 74 and 90.6 mg kg(-1) wet weight for control, low and high dose, respectively. The biomarkers used were total oxyradical scavenging capacity (TOSC) in the digestive gland and cell membrane stability of haemocytes. TOSC values were significantly reduced (ca. 30%) in exposed groups (P < 0.05), indicating a depletion in oxyradical molecular scavengers. The antioxidant defences appeared to be overwhelmed by the reactive oxygen species as the plasma membranes of haemocytes were destabilised (P < 0.05) probably due to lipid peroxidation. These data indicate that reactive oxygen species (ROS) were produced by Arctic scallops via the metabolisation of benzo(a)pyrene at 2 degrees C.


Asunto(s)
Benzo(a)pireno/efectos adversos , Membrana Celular/patología , Depuradores de Radicales Libres/análisis , Moluscos/fisiología , Estrés Oxidativo , Contaminantes Químicos del Agua/efectos adversos , Adaptación Fisiológica , Animales , Antioxidantes/análisis , Regiones Árticas , Benzo(a)pireno/metabolismo , Biomarcadores/análisis , Frío , Hemocitos/fisiología , Contaminantes Químicos del Agua/metabolismo
14.
Aquat Toxicol ; 127: 21-35, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22310169

RESUMEN

In the Barents Sea, the limited data on biological relevant indicators and their responses to various anthropogenic stressors have hindered the development of a consistent scientific basis for selecting indicator species and developing practical procedures for environmental monitoring. Accordingly, the main aim of the present study was to develop a common set of baseline values for contaminants and biomarkers in three species, and to identify their strengths and limitations in monitoring of the Barents Sea. Blue mussel (Mytilus edulis), Icelandic scallop (Chlamys islandica) and Atlantic cod (Gadus morhua) were sampled from a north Norwegian fjord in March, June, September and December 2010. Digestive glands from the bivalve species and liver from Atlantic cod were analysed for biomarkers of oxidative stress (catalase [CAT], glutathione peroxidase [GPX], glutathione-S-transferase activities [GST], lipid peroxidation as thiobarbituric reactive substances [TBARS] and total oxyradical scavenging capacity [TOSC]), biotransformation (ethoxyresorufine-O-deethylase activity [EROD]) and general stress (lysosomal membrane stability [LMS]). Concentrations of polycyclic aromatic hydrocarbons (PAHs) and metals in the bivalves and PAH metabolites in fish bile were quantified. Finally, energy reserves (total lipids, proteins and carbohydrates) and electron transport system (ETS) activity in the digestive gland of the bivalves and liver of Atlantic cod provided background information for reproductive cycle and general physiological status of the organisms. Blue mussel and Icelandic scallop showed very similar trends in biological cycle, biomarker expression and seasonality. Biomarker baselines in Atlantic cod showed weaker seasonal variability. However, important biological events may have been undetected due to the large time intervals between sampling occasions. Physiological biomarkers such as energy reserves and ETS activity were recommended as complementary parameters to the commonly used stress biomarkers, as they provided valuable information on the physiological status of the studied organisms. Interpretation of the seasonality in oxidative stress biomarkers was in general difficult but TOSC and lipid peroxidation were preferred over the antioxidant enzyme activities. This study is the first reporting seasonal baseline in these three species in a sub-Arctic location. Overall, the Icelandic scallop was considered the most adequate organism for environmental monitoring in the Barents Sea due to the interpretability of the biomarker data as well as its abundance, ease to handle and wide distribution from the southern Barents Sea to Svalbard.


Asunto(s)
Biomarcadores/análisis , Monitoreo del Ambiente , Gadus morhua/fisiología , Mytilus edulis/fisiología , Pectinidae/fisiología , Estaciones del Año , Animales , Gadus morhua/metabolismo , Mytilus edulis/metabolismo , Océanos y Mares , Pectinidae/metabolismo , Contaminantes Químicos del Agua/toxicidad
18.
J Clin Psychopharmacol ; 12(4): 273-5, 1992 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-1527231

RESUMEN

Eight schizophrenic inpatients participated in a 2-week double-blind crossover study to test the efficacy of methylphenidate treatment for patients on a stabilized neuroleptic dose. All were young men with a childhood history of hyperactivity. The instruments used, the Brief Psychiatric Rating Scale, Scale for Assessment of Positive Symptoms, Scale for Assessment of Negative Symptoms, and Nurses Observation Scale for Inpatient Evaluation, showed no significant differences between stimulant and placebo conditions. One patient suffered a repeated pressor effect and was removed from the protocol. However, staff and self-report found some improvement in 3 patients and a slight worsening in 1.


Asunto(s)
Metilfenidato/uso terapéutico , Esquizofrenia/tratamiento farmacológico , Adulto , Método Doble Ciego , Humanos , Masculino , Escalas de Valoración Psiquiátrica , Psicología del Esquizofrénico
19.
Aten Primaria ; 8(9): 682, 684-6, 1991 Oct.
Artículo en Español | MEDLINE | ID: mdl-16989054

RESUMEN

OBJECTIVE: An evaluation of the programme with respect to the objective set for the year 1989 and a comparison with the evaluation results from previous years. DESIGN: It is a retrospective diachronic study, by observation. LOCATION: The study was carried out in the primary health area in the basic health zone of La Chana in the Granada North health district. PATIENTS: All pregnancies attended in the basic health zone during 1989. FIGURES AND PRINCIPAL RESULTS: 223 women reached the end of the pregnancy in 1989 of whom 207 joined the programme. The level of puerperal visits (83.5% of the pregnancies) and the coverage of the programme (59.4%) were below target. Other indicators were above target. The average number of visits per pregnancy has reduced over the years (5.5 in 1987; 4.5 in 1988; 4.4 in 1989), while the percentage for risk levels has been maintained. CONCLUSIONS: The programme seems valid but could be improved, particularly where coverage is concerned. Analysis and comparison of results with previous years highlights the lack of coordination existing between the different levels of attendance. Finally we have to point out that we are unaware of the quality of attention which is received, and this aspect should receive serious study.


Asunto(s)
Atención Prenatal/estadística & datos numéricos , Atención Prenatal/normas , Evaluación de Programas y Proyectos de Salud , Femenino , Humanos , Embarazo , España
20.
Aten Primaria ; 10(4): 726-9, 1992 Sep 15.
Artículo en Español | MEDLINE | ID: mdl-1420792

RESUMEN

OBJECTIVE: Determine the quality of prenatal assistance by means of an audit. DESIGN: This is a retrospective and longitudinal observational study. SITE. At the Primary Attention level, at the "La Chana" Health Centre, Granada. PATIENTS: 514 mothers-to-be. MAIN MEASUREMENTS AND RESULTS: The completion rate of the programme was studied via twelve indicators. Gynecological examination during the first visit (37.74%), serology of infections and toxoplasma (32%) and AgHBs (14.28%) were the indicators least carried out. Gestatory age (98.84%) probable date of the birth (98.45%) and arterial blood pressure (96.7%) were those most frequently carried out. CONCLUSIONS: Motivation exists in the Primary Attention team to record complete medical histories. Need to: unify therapeutic diagnostic criteria, increase coordination between the different levels of attention, and carry out audits more often, to evaluate the quality of attention given objectively.


Asunto(s)
Atención Prenatal , Atención Primaria de Salud , Calidad de la Atención de Salud , Humanos , Estudios Longitudinales , Atención Prenatal/métodos , Atención Primaria de Salud/métodos , Estudios Retrospectivos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA