Population and gender-based differences in tissue-specific enzyme activities in brackish water and freshwater threespine sticklebacks, Gasterosteus aculeatus

Sticklebacks (Gasterosteus aculeatus) from a brackish water and a freshwater population were compared immediately after removal from their habitat and after being maintained in the laboratory. Glutamate dehydrogenase activities in the liver and both lactate dehydrogenase and aspartate aminotransferase activities in the axial muscle were higher in the brackish water sticklebacks than in the freshwater specimens. Liver glutamate dehydrogenase activities were higher in males than in females, whereas lactate dehydrogenase activities were distinctly higher in females. A significant positive correlation was found between size and both aspartate aminotransferase and lactate dehydrogenase. The population-specific activities of muscle enzymes are interpreted as an example of evolutionary adaptation of enzyme regulation. Received: 28 February 1997 / Accepted: 5 August 1997     

Firm incentives to promote technological change in pollution control: Comment

Following on from an analysis by Milliman and Prince, this article considers further the relative incentives for technical change provided by different pollution control instruments. The comments involve the recognition that emission targets are typically chosen fairly arbitrarily because of regulators' lack of knowledge of abatement cost schedules. There is also a more detailed discussion of the practicability of auctioning emissions permits, as these have been less thoroughly covered in the literature than the other instruments.     

Rapid molecular prenatal diagnosis of ataxia-telangiectasia by direct mutational analysis

Mutations of the ataxia-telangiectasia-mutated (ATM) gene are responsible for the autosomal recessive disorder ataxia-telangiectasia (A-T). This study reports the first A-T prenatal diagnosis performed in Spain by direct molecular analysis. The pregnant woman had a previous child suffering from A-T due to a deletion in the ATM gene. The ATM coding region was sequenced in the A-T patient and her parents. Then, a specific polymerase chain reaction (PCR) to detect the deletion was performed for prenatal diagnosis. Additionally, polymorphic HLA loci were examined in order to exclude the possible contamination by maternal DNA. In this family of Gypsy origin, we carried out a rapid molecular diagnosis of A-T. Then, a prenatal diagnosis was carried out, identifying the deletion in the fetal DNA. Additionally, we performed a population study in unrelated Spanish Gypsies and in unrelated controls, showing that the deletion described could be a hotspot in the Spanish Gypsy population. The size of the coding region and the genomic structure, together with the absence of hotspots, make the mutation screening of the ATM gene difficult. The ability to identify ATM mutations provides a tool that can be applied in confirmatory diagnosis, genetic counselling, carrier prediction and prenatal diagnosis. Copyright © 2007 John Wiley & Sons, Ltd.     

Sedimentary organic matter and bacterial community in microtidal mixed beaches of the Ligurian Sea (NW Mediterranean)

The quantity and quality of organic matter, and bacterial density and frequency of dividing cells were investigated in six microtidal mixed beaches of the Ligurian Sea (NW Mediterranean) to evaluate their main trophodynamic features. Concentrations of biopolymeric carbon (average 88.5?±?89.0 µgC/g) and the protein:carbohydrate ratio (on average lower than 1) were very low and classified these beaches as highly oligotrophic. The study of biochemical composition highlighted the nature of organic matter as being mainly refractory; furthermore, the quantitative differences observed along the across-beach gradient together with the unchanged pattern in qualitative features suggest that the organic matter in Ligurian beaches is prevalently of marine origin. This implies a negligible contribution of allochtonous and anthropogenic terrestrial input or in situ autochthonous production. Bacterial density displayed values ranging from 0.1–9.0 cell?×?10⁸/g DW in the top 2?cm layer and showed a significant correlation with the quantity of organic matter. In addition, the frequency of dividing cells showed a positive correlation with the protein:carbohydrate ratio, suggesting that the biochemical composition of organic matter also has an influence on the active bacterial fraction. Because of the exposed nature, a strong coupling was found between the beach and the marine systems, and this seems to be of fundamental importance in terms of material and energy supply for the beach ecosystem. A shortage within this linkage was observed in summer owing to the strong environmental constrains leading to a sort of “beach desertification” and to a marked oligotrophy. Summer also has an effect of smoothing for spatial variability occurring within the biochemical and microbiological variables among the different beaches. The linkage observed between the sea and the land is the main factor controlling the origin and nature of sediment organic matter in these beaches also regulating bacterial abundances and the frequency of dividing cells.     

The bioaccumulation and translocation of Fe,Zn, and Cu in species of mushrooms from <Emphasis Type="Italic">Russula</Emphasis> genus

Introduction  

Many previous studies revealed a high ability of mushrooms to accumulate heavy metals from environment. This paper concerns the capacity of some wild macromycetes belonging to Russula genus to accumulate heavy metals in natural condition of pH (between 6.5 and 6.8) and the pattern of metal translocation in the fruiting body.     

Congener profile, occurrence and estimated dietary intake of dioxins and dioxin-like PCBs in foods marketed in the Region of Valencia (Spain)

During 2006-2008, a monitoring program was conducted on 29 target compounds, including PCDD/Fs and dl-PCBs, comprising 150 randomly collected individual food samples marketed in the Region of Valencia, Spain, grouped into 8 categories (vegetables, cereals, fats and oils, eggs, milk and dairy products, fish products, meat and meat products and fish oil). For PCDD/Fs, the highest frequency of detection corresponds to 1,2,3,4,6,7,8-HpCDD, OCDD, 2,3,4,7,8-PeCDF; and PCBs 118, 105 and 156 were the more frequent dl-PCBs. The food groups presenting higher contamination, expressed as toxic equivalents (WHO-TEQs), were fish oil (6.38 pg WHO-TEQ g⁻¹ fat), fish (1.21 pg WHO-TEQ g⁻¹ w.w.) and milk and dairy products (0.90 pg WHO-TEQ g⁻¹ fat). Of all analysed samples, only two fish oils presented levels higher than the EU limits for total WHO-TEQ. The average PCDD/Fs and dl-PCBs intakes were estimated as 2.86 pg WHO-TEQ kg⁻¹ b.w. d⁻¹ and 4.58 pg WHO-TEQ kg⁻¹ b.w. d⁻¹, for adults and children, respectively, using the deterministic method for chronic exposure. The main contributors to total intake for adults were fish (59%), milk and dairy products (19%), and fat and oils (9%). The average daily intake for adults (2.86 pg WHO-TEQ kg⁻¹ b.w. d⁻¹) is within range of TDI recommended by the WHO (1-4 pg WHO-TEQ kg⁻¹ b.w. d⁻¹), and slightly above the TWI and PTMI adopted by SCF and JECFA respectively.     

Effects of salinity on the clam <Emphasis Type="Italic">Chamelea gallina</Emphasis> haemocytes. Part II: Superoxide dismutase response

The effects of different salinity levels (28, 34 and 40‰) on functional responses of Chamelea gallina haemocytes were evaluated in a two part study dealing with modulations of immune parameters. This part (Part II) of the study was focused on the superoxide dismutase (SODs) activity and expression in haemocyte lysate and cell-free haemolymph. Results of this study established that the exposure of C. gallina specimens at 40‰ salinity provoked a decrease in Mn-SOD and Cu/Zn-SOD activities in haemocyte lysate suggesting a declining superoxide anion generation at the highest salinity tested. Expression of MnSOD was coherent with activity values, while Cu/ZnSOD showed two immunoreactive bands. The former corresponds to the cytosolic Cu/Zn-SOD (16 kDa) was not coherent with the enzyme activity and the second (28–30 kDa) probably attributed to EC-SOD. In cell-free haemolymph, Mn-SOD activity decrease and Cu/Zn-SOD activity increase at 40‰ were observed, likely due to EC-SOD contribution, strongly induced at the same salinity. After EC-SOD detection with two different antibody, we postulate that the EC-SOD like-protein band (29 kDa) may be constitute partly by EC-SOD and probably by Cu/Zn-SOD dimeric form not completely dissociated under reducing condition or a Cu/Zn-SOD degenerated but still recognized by antibody. The cell-free haemolymph increase of EC-SOD at high salinity values plays an important role in immune defence of C. gallina. According to the conclusion of Part I of this study, our data confirmed the destabilizing effect of 40‰ salinity on haemocyte functionality, while to 28‰ exposure, data don’t confirm its stressful action as instead stated by results of Part I. Further studies are necessary to clear up this discrepancy.     

Mesozooplankton community structure in offshore and coastal waters of the Ionian Sea (eastern Mediterranean) during mixed and stratified conditions

Depth-stratified samples, collected during a period where the water column was vertically mixed (March 2000) and a period of thermal stratification (September 2000), were analyzed in order to investigate the horizontal and vertical distribution patterns and composition of mesozooplankton, especially copepod species assemblages, in a pelagic (Ionian Sea) and a coastal area (Patraikos Gulf) of the eastern Mediterranean. Total mesozooplankton abundance and biomass were significantly lower in the highly oligotrophic offshore waters of the Ionian Sea when compared to the semi-enclosed Patraikos Gulf during both seasons. Small-sized copepods dominated the mesozooplankton community. An ‘offshore’ and a ‘coastal’ copepod assemblage were defined in the surface layer (0–50 m) only during March when differences in environmental conditions (i.e., temperature, salinity and fluorescence) were strong between the two areas. Copepod vertical community structure in offshore waters differed between sampling months. In March one assemblage (0–200 m) was mainly identified, while in September three distinct assemblages (0–50, 50–100 and 100–200 m) were observed, related to different vertical distribution patterns of the various copepod species. A pronounced seasonal change of the dominant copepods was evident in the surface layer, where strong differences in hydrological properties were observed from March to September. Below this layer, the copepod community was relatively stable showing decreasing seasonal differences with increasing depth.