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F Galgani

Publications and source records attributed to F Galgani.

12 recordsLinked to original sources
PubMed2001

Tributyltin along the coasts of Corsica (Western Mediterranean): a persistent problem.

Despite optimistic forecasts by various scientists after regulatory measures were taken in the 1980s, coastal tributyltin (TBT) contamination is still a major problem. The present study concerning Corsica (Western Mediterranean) shows that contamination is not limited to harbour areas, but extends along the coast, involving protected nature reserves. The concentrations measured in harbours, which can reach 200 ng TBT l(-1), tend to incriminate both pleasure craft and ferries providing regular service between the island and the continent. Contamination as high as 7 ng TBT l(-1) has been measured in waters of the Scandola nature reserve, which is quite excessive given the no effect concentrations (NOEC) for marine fauna are around 1-2 ng TBT l(-1). The inadequacy of current regulations and their application are a major factor in this situation.

Environmental Monitoring↗
PubMed2000

Evidence of p53 mutation in an early stage of liver cancer in European flounder, Platichthys flesus (L.).

A number of flounders dwelling in highly contaminated coastal areas of Northern Europe develop liver tumours. In order to increase our understanding of the molecular pathogenesis of these sporadic tumours, we examined p53 mutations in eleven hyperplasia and six adenoma. p53 introns 4 to 8 were first sequenced to allow individual amplification of exons 5 to 8. DNA extracted from formalin-fixed livers was amplified and PCR products were directly sequenced. Two major results were obtained. (i) Flounders from different geographical areas displayed a high rate of sequence variation. Base substitutions were identified in both tumour and normal tissues and thus may be considered as polymorphic variations in individuals. (ii) One mutation was detected in two hyperplastic foci from the same flounder. This mutation was a T:A to A:T transversion at codon 147, resulting in the replacement of valine for glutamic acid. This residue took place in the L2 loop of the DNA binding surface. Its substitution by an hydrophilic and charged residue could thus impair p53 (protein) biological activity.

Adenoma, Liver Cell↗
PubMed1999

A simple procedure for polymerase chain reaction of the PSBA gene in algae: application to the screening of mutations conferring atrazine resistance and discrimination of natural populations of Porphyra linearis.

A simplified procedure is described for polymerase chain reaction (PCR) of a partial sequence (bp 601-893) of the plastid gene psbA in the rhodophyte Porphyra linearis and the diatoms Haslea ostreria and Skeletonema costatum. This procedure involves the use of all tissues of P. linearis and live cell suspensions of H. ostreria or S. costatum, as DNA templates, without any further purification of DNA. As in the case of PCR with DNA extracts, a single major band of the expected size (292 bp) was obtained after PCR for the three species. Sequences of the amplified fragments were aligned, confirming that the amplified products were part of the psbA gene. The method was then used to screen mutations in partial psbA genes of 23 samples of P. linearis collected at four different stations along the mid-Atlantic coast of France. An alignment was obtained indicating the existence of mutations, though not in codons known for herbicide resistance. All mutations found were silent. However, genetic polymorphism discriminated between samples collected from two stations. The method employed allows rapid amplification of the herbicide target gene and simplifies the procedure for screening mutations or populations in algae. Its application to other genes and species is considered.

Atlantic Ocean↗
PubMed1998

cDNA cloning and expression analysis of flounder p53 tumour suppressor gene.

The screening of a flounder cDNA library with a rainbow trout p53 probe allowed the isolation of a 2.8-kb fragment homologous to human (50%) and rainbow trout (57%) p53 coding sequences. The fragment contains a single open reading frame coding for a 366-amino acid protein. The predicted amino acid sequence is relatively divergent from other p53 proteins but it displays the main p53 features: five highly conserved domains, an acidic N-terminus, a hydrophilic and charged C-terminus, a penultimate serine residue and a putative nuclear localization signal. Furthermore, conservation of critical amino acids and comparable distribution of charge and hydrophobicity suggest that flounder p53 properties could be similar to those in mammals. Northern blot analysis revealed a single transcript of about 3 kb in the flounder ovary tissues. In fact, RT-PCR showed an ubiquitous but very low expression of p53 gene in all flounder tissues.

Amino Acid Sequence↗
PubMed1998

Production of a polyclonal antibody raised against recombinant flounder p53 protein.

The cDNA encoding the wild type p53 protein from flounder, Platichthys flesus, was expressed in Escherichia coli using the GST fusion protein system. Several milligrams of recombinant p53 protein were purified. This protein displayed an apparent molecular weight of 45,000 Da, a value which is very similar to Xenopus p53, but significantly greater than was expected based on the length of the open reading frame. Immunization of rabbits against purified p53 protein allowed the production of high titre polyclonal antiserum. This new polyclonal antibody recognized recombinant flounder p53 protein in Western blot. Cross reaction was also observed with recombinant Xenopus p53 protein but not with human p53 protein. Immunoblotting of the total protein extract from normal flounder ovaries did not reveal any p53 expression.

Animals↗
PubMed1998

Two cases of ras mutation associated with liver hyperplasia in dragonets (Callionymus lyra) exposed to polychlorinated biphenyls and polycyclic aromatic hydrocarbons.

ras gene activation in a naturally exposed feral fish population may prove to be a particularly sensitive genetic marker of malignancy. The aim of this study was to relate our current knowledge of polychlorinated biphenyl (PCB) bioactivation and polycyclic aromatic hydrocarbon (PAH)-induced DNA damage to ras gene activation in liver tumors from dragonets exposed to these environmental carcinogens. We identified a member of the ras gene family in the marine fish dragonet (Callionymus lyra). The first two exons of this new sequence showed a very high degree of homology with the human ras genes (81-86%) at the nucleic acid level and perfect homology at the amino-acid level. In a pilot study, we collected dragonets from the Seine estuary, an area highly contaminated with PAHs and PCBs. An increase in DNA adducts and an accumulation of ortho- and non-ortho-substituted chlorobiphenyls (CB-77, CB-126, and CB-169) were observed in the livers, a finding that correlates well with the levels of PAHs and PCBs in the sediment. Although liver neoplasia was uncommon, a codon 11 mutation was found in two fish with liver cell hyperplasia, suggesting a possible correlation between hepatic precancerous lesions and ras gene activation in dragonets.

Animals↗
PubMed1995

Expression of ras gene in flounder (Platichthys flesus) andred mullet (Mullus barbatus).

A member of the ras gene family was identified here for the first time in two marine fish, the flounder (Platichthys flesus) and the red mullet (Mullus barbatus). After RT-PCR the partial sequence of ras gene (exons 1 and 2) has been cloned and sequenced from normal liver. At the nucleic acid level, a very high extent of homology with the human ras genes is observed (80% to 86%) and a perfect homology is observed at the amino acid level. The high conservation of the 5' region of the ras gene suggest that the p21 protein has identical function in higher and lower vertebrates. The identification of ras gene should be a first step in understanding the molecular basis of carcinogenesis in these species.

Amino Acid Sequence↗
PubMed1995

The micronucleus assay in Crassostrea gigas for the detection of seawater genotoxicity.

The micronucleus (MN) test was performed in vivo and in vitro on the oyster Crassostrea gigas to evaluate the genotoxic effect of the marine environment. In vitro tests were carried out on adult and young (spat) specimens exposed to benzo[a]pyrene (BaP: 0.5, 5, 500 and 1000 micrograms.l-1) and an effluent (5, 50, 75 and 100%) of Seine Bay, one of the most highly contaminated sites in France. MN frequency observed after 48 h exposure to the two pollutants was much greater in adults than spats. A preliminary test of the genotoxic effect of BaP (0.05, 0.5, 1 and 500 micrograms.l-1), cupric sulfate (10, 25, 50 and 100 micrograms.l-1) and a paper mill effluent (1, 3, 10 and 30 mg.l-1) was performed in C. gigas heart cells cultured for 6 days. Comparison of the MN assay with the C. gigas larva test showed the clastogenic action of BaP and the toxic effect of cupric sulfate on culture cells as well as the slighter toxic effect of paper mill effluent on spats. An in vivo study was conducted in an oyster-farming area contaminated by cadmium and copper. MN frequency was not very sensitive to a pollution gradient but showed high interindividual variability. The absence of precise criteria for MN identification in mollusks and the identification of highly basophilic spherical inclusions in the cytoplasm of gill tissue hemocytes in oysters during viral infection are handicap for application of the micronuclei assay in the marine environment. Another limitation of the assay is the particularly onerous requirement for manual observation. Optimization of the assay by automated analysis is necessary but can only be achieved if cytologic preparations are of good quality.

Animals↗
PubMed1993

P-glycoprotein expression in Crassostrea gigas and Mytilus edulis in polluted seawater.

1. DNA-DNA hybridization showed that mussels (Mytilus edulis) and oysters (Crassostrea gigas) possess a highly conserved region constituting one or more genes of the ATP-dependent transmembrane transporter family to which belong the mammalian tumor cell genes responsible for multi-drug resistance. 2. Monoclonal antibody C219 visualized two proteins (220 and 240 kDa) which varied quantitatively in mussels depending on the level of organic pollution at the sampling sites. 3. The authors consider whether certain pollutants in the marine environment are capable of inducing pollutant-resistant gene expression.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1992

Simultaneous and iterative weighted regression analysis of toxicity tests using a microplate reader.

A system is described for determination of LC50 or IC50 by an iterative process based on data obtained from a plate reader using a marine unicellular alga as a target species. The esterase activity of Tetraselmis suesica on fluorescein diacetate as a substrate was measured using a fluorescence titerplate. Simultaneous analysis of results was performed using an iterative process adopting the sigmoid function Y = y/1 (dose of toxicant/IC50)slope for dose-response relationships. IC50 (+/- SEM) was estimated (P less than 0.05). An application with phosalone as a toxicant is presented.

Cholinesterase Inhibitors↗
PubMed1991

Acetylcholinesterase activity in the common prawn (Palaemon serratus) contaminated by carbaryl and phosalone: choice of a method for detection of effects.

Organophosphorus compounds and carbamates are pesticides which inhibit acetylcholinesterase activity. The toxicity of phosalone and carbaryl was studied for 29 days in the adult common prawn (Palaemon serratus). Induction thresholds for inhibitory effects were determined and the toxicity of these two pesticides was investigated. For monitoring purposes, several methods of assessing the effects of these two pesticides in the marine environment are considered and discussed.

Acetylcholinesterase↗