Effect of mussel reproductive status on biomarker responses to PAHs: Implications for large-scale monitoring programs.

Biomarkers are useful tools to assess biological effects of pollutants and have been extensively used in monitoring programs to determine ecosystem health. In these programs, a wide range of environmental conditions are covered and sometimes, obtained data are difficult to interpret because of natural variables are affecting biomarker responses. Among these variables, mussels reproductive status has been considered one of the most changing variables between sites in a monitoring survey. Thus, the main aim of this work was to identify the effect that mussel reproductive status has on biomarker responses. For that purpose, mussels sampled at two periods in the reproductive cycle (reproductive and resting stages) were conditioned to the same laboratory conditions and exposed to fluoranthene (FLU) for three weeks. Studied biomarkers covering a wide range of organism responses were included: bioaccumulation, physiological rates (clearance rate -CR-, absorption efficiency -AE-, respiration rate -RR- and their integration in the scope for growth -SFG-), antioxidant enzyme activities (superoxide-dismutase -SOD-, catalase -CAT-, glutathione reductase -GR-, glutathione peroxidase -GPx-, glutathione-S-tranferase -GST-) and biochemical damage responses (lipid membrane peroxidation -LPO-). The results obtained evidenced that the levels of the biomarkers studied (RR, SOD, CAT and GPx) were higher at reproductive than at resting stage. On the other hand, the effect of toxicant was observed in SFG, CAT and GPx but this effect was only detected during the resting period. Moreover, there was a deterioration of mussel gonadal tissue with FLU exposure during reproductive stage. FLU accumulation in mussel tissues was also dependent of the reproductive status with higher internal concentrations during resting than reproductive period. In conclusion, there was a strong effect of reproductive status on studied biomarkers which seems to mask the effect of FLU at reproductive stage. The present study evidences the need to include the measurement of mussel biological status in marine pollution monitoring programs for a correct interpretation of biomarker data.

Effect of nutritive status on Mytilus galloprovincialis pollution biomarkers: Implications for large-scale monitoring programs.

Biomarkers have been extensively used in monitoring programs with the aim of assessing the biological effects of pollutants on marine organisms and determining environmental status. Data obtained from these programs are sometimes difficult to interpret due to the large amount of natural variables affecting biological processes, which could act as confounding factors on biomarker responses. The main aim of this work was to identify the effect of one of these variables, the food availability, and consequently, the mussel nutritive status, on biomarker responses. For that purpose, mussels (Mytilus galloprovincialis) were conditioned to three different food rations for 2 months in order to create three mussel nutritive statuses and afterwards, each status was exposed to three nominal concentrations of fluoranthene (FLU) for 3 weeks. A battery of biomarkers was considered in this study to cover a wide range of organism responses, both physiological (scope for growth - SFG) and biochemical (superoxide dismutase - SOD, catalase - CAT, glutathione reductase - GR, glutathione peroxidase - GPx, glutathione-S-transferase - GST and phenoloxidase - PO activities, and lipid membrane peroxidation - LPO). The results obtained, evidenced that most of the studied biomarkers (SFG, SOD, CAT, GPx, and PO) were strongly affected by mussel nutritive status, showing higher values at lower status, whereas the effect of toxicant was not always evident, masked by the nutritive status effect. This paper demonstrates that toxicants are not the only source of variability modulating pollution biomarkers, and confirms nutritive status as a major factor altering biochemical and physiological biomarkers.

Influence of mussel biological variability on pollution biomarkers.

This study deals with the identification and characterization of biological variables that may affect some of the biological responses used as pollution biomarkers. With this aim, during the 2012 mussel survey of the Spanish Marine Pollution monitoring program (SMP), at the North-Atlantic coast, several quantitative and qualitative biological variables were measured (corporal and shell indices, gonadal development and reserves composition). Studied biomarkers were antioxidant enzymatic activities (CAT, GST, GR), lipid peroxidation (LPO) and the physiological rates integrated in the SFG biomarker (CR, AE, RR). Site pollution was considered as the chemical concentration in the whole tissues of mussels. A great geographical variability was observed for the biological variables, which was mainly linked to the differences in food availability along the studied region. An inverse relationship between antioxidant enzymes and the nutritional status of the organism was evidenced, whereas LPO was positively related to nutritional status and, therefore, with higher metabolic costs, with their associated ROS generation. Mussel condition was also inversely related to CR, and therefore to SFG, suggesting that mussels keep an "ecological memory" from the habitat where they have been collected. No overall relationship was observed between pollution and biomarkers, but a significant overall effect of biological variables on both biochemical and physiological biomarkers was evidenced. It was concluded that when a wide range of certain environmental factors, as food availability, coexist in the same monitoring program, it determines a great variability in mussel populations which mask the effect of contaminants on biomarkers.

Selective arterial embolization with ethylene-vinyl alcohol copolymer for control of massive lower gastrointestinal bleeding: feasibility and initial experience.

PURPOSE: To evaluate the efficacy, safety, and clinical outcomes of superselective embolization using ethylene-vinyl alcohol copolymer (Onyx Liquid Embolic System; ev3 Neurovascular, Irvine, California) as the primary treatment for acute and massive lower gastrointestinal bleeding (LGIB). MATERIALS AND METHODS: Between January 2008 and October 2013, all patients with focal massive LGIB who were treated by embolization were retrospectively analyzed. The study was approved by the hospital's ethics committee; informed consent was obtained in all cases. Onyx was chosen as the embolic agent in all cases in an intention-to-treat fashion. Embolization was indicated in 31 consecutive patients (mean age, 80 y ± 11.1). Multidetector computed tomography and digital subtraction angiography were performed in all patients. RESULTS: Active bleeding was detected in all cases. A colonoscopy was performed in 11 patients. The correlation between multidetector computed tomography and angiography findings was 96.7%. The causes of bleeding were diverticula in 15 patients, iatrogenic in 7 patients, neoplasia in 3 patients, hemorrhoids in 2 patients, angiodysplasia in 2 patients, and unknown in 2 patients. Embolization was not possible in one patient, who required urgent left hemicolectomy. The technical success rate was 93.5%. The embolic material refluxed in one patient, causing an undesired embolization, without any clinical consequences. In the 30 patients who received embolization, the immediate bleeding control rate was 100%. Rebleeding at 30 days occurred in three patients (10%). There were no major complications, intestinal ischemia, or deaths attributable to the treatment. No patient needed surgery or new embolization during a mean follow-up period of 23.7 months (range, 1-71 mo). CONCLUSIONS: Control of massive LGIB using superselective embolization with Onyx is feasible and safe.

Pure right ventricular infarction resulting from coronary ectasia: importance of diagnostic imaging.

Isolated right ventricular (RV) infarction may occur during percutaneous coronary intervention resulting from selective occlusion of a ventricular branch of the right coronary artery (RCA). We present a case of a pure RV infarction without iatrogenic origin that at the initial electrocardiographic analysis was suggestive of a left anterior descending artery-related acute myocardial infarction. Coronary angiography results made us suspect thrombotic occlusion of a small branch of the ectatic RCA resulting from slow flow. Final diagnosis was confirmed by coronary computed tomographic angiography and cardiac magnetic resonance imaging, underlining the essential diagnostic role of these imaging modalities.

First measurements of the scope for growth (SFG) in mussels from a large scale survey in the North-Atlantic Spanish coast.

SFG and physiological rates were measured in wild mussels from the Spanish Marine Pollution monitoring program (SMP) in order to determine seawater quality. It consists of 41 stations, covering almost 2500 km of coast, making the SMP the widest-ranging monitoring network in the Iberian Peninsula's Atlantic region. Results of the 2007 and 2008 surveys when 39 sites were sampled: (20 in 2007 and 19 in 2008, being 8 sites sampled both years) were presented. Chemical analyses were carried out to determine the relationships between physiological rates and the accumulation of toxic compounds. Data presented are the first to become available on the use of SFG as a biomarker of the marine environment on a large spatial scale (>1000 km) along Spain's Atlantic seaboard. SFG values enable significant differences to be established between the areas sampled and between the two years surveyed. The integration of biological and chemical data suggests that certain organochlorine compounds, namely chlordanes and DDTs, may have a negative effect on SFG, although such an effect is of a lesser magnitude than that associated with certain biological parameters such as condition index and mussel age. These variables act as confounding factors when attempting to determine the effect of chemical compounds present in the marine environment on mussel SFG. Further research is therefore needed on the relation between these confounding factors and SFG in order to apply the relevant corrective strategies to enable this index to be used in monitoring programs. The effect of these confounding factors is more clearly revealed in studies that cover a wide-ranging spatial and time scale, such as those carried out within the SMP. These results do not invalidate the use of biological data in monitoring programs, but rather point to the need to analyze all the factors affecting each biological process.

Temporal and spatial changes of PAH concentrations in Mytilus galloprovincialis from Ria de Vigo (NW Spain).

The aim of this study was to establish the temporal trends and spatial distribution of Polycyclic Aromatic Hydrocarbons (PAHs) in Ria de Vigo by means of studying the PAH burden in wild mussels. The samples were collected in eight sites along the margins of the Ria de Vigo during November from 1998 to 2008 and Polycyclic Aromatic Hydrocarbon contents were determined using high performance liquid chromatography-fluorescence derivatization (HPLC-FLD). Quality of chemical analysis was guaranteed by participation in QUASIMEME intercalibration exercises carried out during the period of analysis. The concentrations for the sum of 13 PAHs were in the range 24-480 µg/kg dw, typical of an urban and industrialized area (50-500 µg/kg dw) except for a punctual input in La Guía in 1998 that led to a concentration above 1,000 µg/kg dw. In general, the sites in the outermost section of the estuary (ría) showed the lowest values, with an increasing gradient in the medium and inner parts of the ría. Temporal patterns show, in general, a downward trend. The relative proportion of 3 and 4 ring PAHs also varies with the site, the former being predominant in the outermost area and the latter in the medium and inner parts of the ría. This is consistently related with the sources and processes taking place in different areas of the estuary.

Integrated assessment of water quality of the Costa da Morte (Galicia, NW Spain) by means of mussel chemical, biochemical and physiological parameters.

The aim of this study was to assess environmental quality at some of the sites most severely affected by the Prestige oil spill off 2 years after the spillage (April and November 2004). For this purpose analyses of polycyclic aromatic hydrocarbons (PAH) and several biochemical (antioxidant enzymes catalase, glutathione reductase, glutathione peroxidase, superoxide dismutase and DT-diaphorase and lipid peroxidation) and physiological [scope for growth (SFG)] biomarkers were determined on wild mussel populations (Mytilus galloprovincialis) collected at four points along the Costa da Morte and compared with those of a reference site not affected by the oil spill. Results showed that PAH contents had markedly decreased 17 months after the accident, although they were higher in April than in November, when they showed values similar to background levels reported for this area. Nevertheless, the predominance of chrysene on PAH profiles, similarly to findings obtained immediately after the spill, indicated the Prestige as their main source. In spite of the low PAH levels recorded, antioxidant activity levels (explained through the integrated antioxidant response-IAR) were higher in the Costa da Morte than at the reference site either in April and November. In April IAR seems to be related to PAH levels found 3 months after the accident (February 2003), suggesting the persistence in the environment of oxidative stress-producing components from the spill. However, evidence of oxidative stress was not reflected at physiological level by scope for growth, with only very slight differences being observed between values from the reference site and those from Costa da Morte sites. In conclusion, although 2 years after the spill PAHs bioaccumulated by mussels from the Costa da Morte had decreased to background levels, biochemical parameters showed signals of oxidative stress in mussels from this area. However, SFG reflected a good health status for the mussel populations studied and did not reveal evidence of physiological disturbance either 17 or 24 months after the Prestige spill.

Expression of endothelial nitric oxide synthase in human peritoneal tissue: regulation by Escherichia coli lipopolysaccharide.

Changes in the expression of endothelial nitric oxide synthase (eNOS) in the peritoneum could be involved in the peritoneal dysfunction associated with peritoneal inflammation. Demonstrated recently in bovine endothelial cells was the existence of cytosolic proteins that bind to the 3'-untranslated region (3'-UTR) of eNOS mRNA and could be implicated in eNOS mRNA stabilization. The present work demonstrates that eNOS protein is expressed in human endothelial and mesothelial peritoneal cells. Escherichia coli lipopolysaccharide shortened the half-life of eNOS message, reducing eNOS protein expression in peritoneal mesothelial and endothelial cells. Moreover, under basal conditions, human peritoneal samples expressed cytosolic proteins that bind to the 3'-UTR of eNOS mRNA. The cytosolic proteins that directly bind to 3'-UTR were identified as a 60-kD protein. After incubation of human peritoneal samples with lipopolysaccharide, the binding activity of the cytosolic 60-kD protein increased in a time-dependent manner. Studies are now necessary to determine the involvement of this 60-kD protein in the regulation of eNOS expression in peritoneal cells and particularly its involvement in the peritoneal dysfunction associated with inflammatory reactions.