1,721,076 research outputs found
Comparative study on trace metal accumulation in the liver of two fish species (Torpedinidae): concentration-size relationship
No full textAbstract: Metal concentrations (Hg, Cd, Pb, As, Cr, Cu, Zn and Ni) were measured in the liver of two fish,Torpedo nobiliana (electric ray) and Torpedo marmorata (marbled electric ray), from theMediterranean Sea in order to comparatively investigate their current pollution status. Maximum-1 w. w.), while marbled electric ray- -1 w. w.) and As (mean: 32.64-1 w. w.). The metal concentrations are similar to those reported in literature, except for Cd, As andNi. Hg concentrations increased with increasing fish body length in both species, whilst no significantconcentration-size relationship was found for other metals. To the best of our knowledge this is thefirst report providing information on trace metal levels and relationship between concentration andsize of these cartilaginous fishes. Future studies on the concentrations and effects of environmentalcontaminants in various torpedinid species are surely needed.[...
Total and methylmercury residues in tuna-fish from the Mediterranean sea
No full textThis study was carried out to determine the current levels of total mercury and methylmercury in the muscle tissue of albacore (Thunnus alalunga) and bluefin tuna (Thunnus thynnus) caught in the Mediterranean sea with the purpose of ascertaining whether the concentrations exceeded the maximum level fixed by the European Commission Decision. Total mercury concentrations ranged from 0.84 to 1.45 mg kg(-1) w.w. (av. 1.17 mg kg(-1) w.w.) and from 0.16 to 2.59 mg kg(-1) (av. 1.18 mg kg(-1) w.w.) in the muscle of albacore and bluefin tuna, respectively. In 78.6% of albacore and in 61.1% of bluefin tuna analysed, total mercury concentrations exceeded the maximum level fixed by the European Commission Decision (Hg = 1 micro g g(-1) wet wt). In the two species, mercury was present almost completely in the methylated form, with percentages between 77 and 100% (av. 91.3%) in albacore and between 75 and 100% (av. 91%) in bluefin-tuna. In order to assess the potential health impact, the estimated weekly intake was calculated. The estimated weekly intake was far above the established Provisional Tolerable Weekly Intake for both species.[...
5-lipoxygenase and cyclooxygenase-2 in porcine parasitic bronchopneumonia: immunohistochemical and biochemical investigations.
No full textEicosanoids are products of arachidonic acid metabolism and have numerous biological roles. The present study aimed to investigate the role of 5-lipoxygenase (5-LOX)- and cyclooxygenase-2 (COX-2)- dependent enzymatic pathways in the pathogenesis of porcine parasitic bronchopneumonia caused by Metastrongylus spp. Pulmonary tissue samples from healthy control and parasitized pigs were processed for histopathological, immunohistochemical and biochemical investigations. In control animals, immunohistochemistry demonstrated that 5-LOX and COX-2 expression was almost exclusively limited to the bronchiolar epithelial cells. Parasitized pigs had greater 5-LOX- and COX-2- specific immunoreactivity, involving a wide range of cell types within foci of granulomatous and eosinophilic bronchopneumonia. Biochemical investigations demonstrated the presence of 5-LOX (and the related product Leukotriene B(4)) and COX-2 (and the related product prostaglandin E(2); PGE(2)) in all tissues under study. COX-2 activity and PGE(2) concentration were significantly higher in diseased lungs compared with normal healthy controls. These findings demonstrate that 5-LOX and COX-2 are differentially expressed in normal versus lungworm-infected lungs and therefore suggest that both biochemical pathways are likely to be involved in the pathogenesis of porcine parasitic bronchopneumonia.[...
Evaluation of trace metal and polychlorinated biphenyl levels in tea brands of different origin commercialized in Italy
Full text linkThe objectives of this study were to investigate the trace element (Hg, Cd, Pb, Cu, Zn, Ni, Fe, Cr and Se) and polychlorinated biphenyl (PCBs) content of several commercially available brands of green and black tea marketed in Italy. The concentrations these chemicals were found to be variable and largely dependent upon the type and brand of analyzed tea. The most abundant element among the essential elements was Fe, followed by Zn, Cu, Se, Ni and Cr, whereas Pb was the predominant among the tested nonessential elements followed by Hg and Cd. Assessment based on several available guidelines showed that element content were low, except for Hg and Ni. The PCBs concentrations were generally low, with a homologue profile dominated by low-chlorinated congeners, namely three- and tetra-PCBs accounting for more than 60% of the total residue. Apart from trace elements, this is the first study documenting in detail the concentrations and congener distribution of PCBs in tea samples of different origin
Total mercury in muscle of benthic and pelagic fish from the south Adriatic sea (Italy)
No full textTotal mercury concentrations were measured from the muscle of different kinds of fish: yellow gurnard (Trigla lucerna), red gurnard (Aspitrigla cuculus) red fish (Helicolenus dactylopterus), skate spp. (Raje spp.), goldline (Sarpa salpa), atlantic bonito (Sarda sarda), mackerel (Scomber scombrus), chub mackerel (Scomber japonicus) caught in the South Adriatic Sea (south Italy) in the period June/August 1995. The highest total mercury levels were found in the benthic marine organisms and particularly in skates (Raje spp.) whose values ranged from 0.05 to 2.65 mg/kg wet wt with a mean value of 1.02 mg/kg wet wt. As for pelagic species, the highest mean levels were observed in Atlantic bonito (0.34 mg/kg wet wt), while in goldline the mean content of total mercury was the lowest (0.07 mg/kg wet wt). According to the rules in force (Official Journal of the European Communities 1994) 53% of skate and Atlantic bonito samples showed concentrations exceeding the peak value of 1 mg/kg, while for the other species, only 28% of samples exceeded the peak value fixed at 0.5 mg/kg. Correlations between total mercury concentration and specimen weight were evident in all examined species except for goldline and skates.[...
Total and methylmercury residues in cartilagineous fish from Mediterranean Sea
No full textConcentrations of mercury and methylmercury residues were determined in the muscle tissue of three cartilaginous fishes Chimaera monstrosa (ghostshark), Torpedo nobiliana (electric ray) and Myliobatis aquila (eagle ray) from the Mediterranean Sea. The highest mean levels of total mercury were detected in ghostshark (3.14 mg/kg wet weight), followed by electric ray (2.42 mg/kg wet weight), and eagle ray (0.83 mg/kg wet weight). Such a variability is influenced by quite a number of factors, among which size, fish ecology and feeding habits. The percentages of the methylated form to total mercury ranged from a minimum of 72% in eagle ray to a maximum of 83% in ghostshark. Relationship between specimen size and mercury and methylmercury concentrations were found in ghostshark species.[...
Polychlorinated biphenyls in seafood contamination levels and human dietary exposure
No full textDifferent species of fish and crustaceans from the Adriatic Sea, were analysed for polychlorinated biphenyls (PCBs) to estimatethe update of daily intake of these contaminants from food. The estimates of the daily TEQs intake b.w. resulted below the range of1–4 pg TEQs/kg b.w./day set by the World Health Organisation for almost all the species examined except for conger and mackerel.This result supports the assumption of a substantial reduction in intake of these compounds from seafood.[...
Total mercury and methylmercury in tuna fish and sharks from the south Adriatic sea
No full textTotal mercury and metylmercury concentrations were measured in tuna fish and sharks from the South Adriatic Sea. The highest mean levels of total mercury were found in Squalus acanthias (6.5 mg/Kg w.w.). In the other species mean mercury levels were notably lower (0.46 mg/Kg w.w. for Auxis rochey; 0.38 mg/Kg w.w. for Prionace glauca). Twenty-two percent of the Auxis rochei samples exceed the legal Italian limit (0.50 mg/Kg w.w.) as specified by the European Commission Directive. No sample of Prionace glauca exceed the legal limit of 1 mg/Kg wet.[...
Relationship between total mercury concentration and fish size in two pelagic fish species: implications for consumer health
No full textTotal mercury concentrations were determined in different size classes of two pelagic fish species of great commercial importance, horse mackerel (Trachurus trachurus) and Mediterranean horse mackerel (Trachurus mediterraneus), to evaluate the relationship between total mercury concentration and fish size and to determine whether any differences might affect the quantitative assessment of mercury exposure for consumers. Mercury concentrations in horse mackerel and in Mediterranean horse mackerel were between 0.16 and 2.41 mu g g(-1) of weight wet (mean, 0.68 mu g g(-1)) and between 0.09 and 1.62 mu g g(-1) (mean, 0.51 mu g g(-1)), respectively. The regression curves revealed a significant relationship between mercury concentration and fish size (length and weight) for both species. Concentrations exceeding the proposed limit for human consumption were observed in 33.3% of the samples of both species and were associated with larger specimens. The consumption of the larger specimens could lead to an increase in mercury exposure for consumers. Estimated weekly intakes, calculated on the basis of concentrations relative to each size class, revealed a high exposure associated with the consumption of fish larger than 30 cm (horse mackerel, 11.63 to 20.16 mu g/kg of body weight; Mediterranean horse mackerel, 5.86 to 13.55 mu g/kg of body weight). An understanding of the factors leading to an increase in mercury exposure can help consumers make informed decisions about eating fish. [...
Mercury accumulation and speciation in muscle tissue of different species of sharks from Mediterranean sea, Italy
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