1,720,988 research outputs found
Characterization of coastal sites by applying genetic and genotoxicity markers in Mytilus galloprovincialis and Tapes philippinarum.
No full textElectrophoretic profiles of allozyme loci (Odh, Gpi, Idh, Pgm, 6Pgd) and early markers of genetic damage have been studied in parallel in Mytilus galloprovincialis and Tapes philippinarum from three coastai zones conceming the Venice Lagoon (off-shore, Malamocco outlet, inner industriaI district). The selected species are filter-feeding bivalves inhabiting the water column and bottom sediments, respectively. In generaI, heterozygosity values were higher in clams than in mussels. Interestingly, heterozygote deficiency was detected in both species, particularly in samples from the industrial area where significant levels of DNA adducts, cytogenetic alterations and DNA strand breaks were also detected. Further work is necessary to extend these data and to investigate the relationships between long-Iasting exposure to toxic and genotoxic contaminants and changes in the genetic structure of native mollusc populations
The reaction between cyanide and the hemocyanin of Carcinus maenas. A kinetic study.
No full textThe kinetics of the reaction between Carcinus maenas hemocyanin and cyanide has been studied at various KCN concentrations and a different temperatures (21° and 4°C) by following the decrease of the copper-peroxide absorption band, centered at 337 nm, of the copper still bound to the protein and the intrinsic fluorescence changes as functions of time. In all conditions used, the absorption band completely disappears and KCN concentration affects only the rate of the process. The reaction is kinetically homogeneous indicating no site-site interaction. The apparent rate constant increases with the square of cyanide concentration and the inverse of O2 concentration. The copper still bound decreases at a rate slower than the 337 nm absorption and the process is not kinetically homogeneous. The fluorescence of the protein increases after an induction period showing an inflection point at about 50% of the total effect. A kinetic model has been proposed on the assumption that the two metal ions are removed sequentially from the active site. The experimental data are in agreement with the theoretical equations derived from the model. The equilibrium constants for the formation of the complex between the first and the second copper ion with cyanide and the rate constants of their decomposition have been calculated. The rate-limiting process for the removal of the second copper ion is the formation of the complex with cyanide
The use of bird feathers for the monitoring of cadmium pollution
No full textThe cadmium contamination mechanism in bird feathers was investigated using starlings fed with diets containing 10 and 50 ppm Cd for five months. The experiment started about two months before the beginning of the annual complete feather molt and lasted until most of the birds completed the molt of the primaries. Concentrations of Cd in liver, kidney, and uropygial gland were highly correlated, but uropygial gland concentration was about 100 times lower. Cadmium was found both in old and new feathers, in a dose-related manner. Old feathers showed higher metal concentrations than new ones and primaries higher than secondaries. Feather Cd concentration correlated with Cd concentration in liver, kidney, and the uropygial gland. The use of bird feathers are, therefore, a reliable method for monitoring cadmium pollution, but differences between feather type and age must be considered to correctly interpret data collected in the field
MONITORING ENVIRONMENTAL STRESS IN INDIGENOUS BLUE MUSSELS ( MYTILUS SP) SAMPLED FROM THE LAGOON OF VENICE
No full textThe environmental stress of Mytilus sp. specimens collected from the mussel populations of four specific sites inside the Lagoon of Venice
and from one offshore site nearby, has been investigated by means of an ecotoxicological biomarker. The approach has been applied to
the Lagoon of Venice in that it constitutes the drainage basin of a highly industrialized region. The study concerned the genotoxic effects,
evaluated as DNA strand breaks by single cell gel electrophoresis, in digestive gland cells and in hemocytes of mussels collected from
December 2005 to September 2006. In both tissues mussels collected inside the Lagoon showed higher levels of DNA damage compared
to specimens from the offshore site with a damage trend significantly increasing from the Lagoon border towards the inner part
Effects and fate of sediment-sorbed linear alkylbenzene sulphonate (LAS) on the bivalve mollusk Mytilus galloprovincialis Lmk.
No full textThe toxicity of LAS on aquatic animals has been evaluated in particular relation to its concentration in water, although it is well known that sediments play an important role as repositories and sources of many contaminants, including surfactants. The aim of this study was to evaluate the effects of sediment-sorbed LAS on the marine mussel Mytilus galloprovincialis exposed to sediments drugged with 132 mg/kg dry weight of LAS mixtures. Four experiments were performed and some physiological parameters (filtration, oxygen uptake, nitrogen excretion) were measured on control and treated animals. In order to study uptake and release of sediment-sorbed LAS by mussels, quantification of weight, percentage of organic matter, LAS concentration and LAS homologue distribution on faeces were determined. Results showed no significant differences in physiological responses of treated mussels compared to controls, and the absence of a toxic action of LAS contaminated sediments. Moreover one notable aspect was that higher LAS concentrations were found in faeces than in uningested sediments recovered from water. This fact is tentatively explained either as the result of decreased desorption in the mussel intestinal tract with respect to circulating water, or as enrichment in fine particles by mussel filter feeding activity
COBALT SUBSTITUTION STUDIES ON BOVINE ERYTHROCYTE SUPEROXIDE-DISMUTASE - EVIDENCE FOR A NOVEL COBALT-SUPEROXIDE DISMUTASE DERIVATIVE
No full text
In situ monitoring of mussel populations in the Venice Lagoon by means of molecular biomarkers
No full textAbstract
The environmental stress of Mytilus sp. specimens collected from five specific sites in the Venice Lagoon (and from one offshore site nearby) has been investigated by means of different ecotoxicological biomarkers.
The study evaluated genotoxic and cytotoxic effects, such as DNA strand breaks and apoptosis, on the digestive gland cells of mussels by using the Single Cell Gel Electrophoresis Test, i.e. Comet Assay.
In order to assess the temporal and spatial trends of these biomarkers within the Venice Lagoon, the same sampling scheme was repeated in two field studies: mussels were collected monthly for a period of seven months from December 1999 to June 2000 and then from December 2005 to June 2006.
Regarding the temporal trend, the DNA damage values were lower in the 2006 study than in the 2000 study. However cell mortality values in the second monitoring were almost double those of the first one.
As for the spatial trend, in both studies mussels collected from the Venice Lagoon showed a higher level of DNA damage than offshore mussels, a trend that increased significantly as we moved from the lagoon border towards the lagoon interior
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