Effect of size on concentrations and cadmium inducibility of metallothionein in the shore crab Carcinus maenas.

Metallothionein (MT) plays an important role in protecting organisms from the adverse effects of Cd, Hg, Zn and Cu. Investigations on mammals show variations in metallothionein concentrations and inducibility with age. This has never been investigated in invertebrates, and we determined the concentrations and inducibility of metallothionein in gills and midgut gland of different size classes of shore crabs from uncontaminated areas.

Use of standard test organisms for sound validation of UV-based ballast water treatment systems.

To challenge ballast water treatment system (BWTS) efficacy for organisms in the size-class 10-50 μm, intake concentration during tests must reach certain minimum requirements. Often, natural concentrations are too low to meet intake requirements and standard test organisms (STOs) are added. We tested the robustness of Tetraselmis suecica and Odontella sp.

UV fluences required for compliance with ballast water discharge standards using two approved methods for algal viability assessment.

This study investigates the extra UV fluence needed to meet the International Maritime Organisation's ballast water discharge standards for the 10-50 μm size-class using the approved vital stain (VS) method compared to the Most Probable Number (MPN) method for organism viability assessment. Low- and medium pressure UV collimated beam treatments were applied to natural algae collected in temperate and tropical water environments and analysed using both methods. About 10 times higher UV fluence was required to meet discharge standards when using VS compared to MPN.

Retention and distribution of methylmercury administered in the food in marine invertebrates: Effect of dietary selenium.

Methylmercury is transported along aquatic food chains from the lower trophic levels and selenium modulates the biokinetics of mercury in organisms in complex ways. We investigated the retention of orally administered methylmercury in various marine invertebrates and the effect of selenium hereon. Shrimps (Palaemon adpersus and P.

Vitellogenin concentrations in feral Danish brown trout have decreased: An effect of improved sewage treatment in rural areas?

Feminization of male and juvenile fish because of exposure to estrogens or estrogenic chemicals in effluents from central wastewater treatment plants (WWTPs) is a worldwide issue of concern. Intersex and induction of the female yolk protein, vitellogenin, in male and juvenile fish are robust biomarkers for estrogenic exposure, and feminized fish have been observed downstream of WWTP outlets in many countries. Danish central WWTPs reduce effluent estrogenicity effectively by advanced sewage treatment, and feminizations have not been observed downstream of central WWTP outlets.

Evaluation of yolk protein levels as estrogenic biomarker in bivalves; comparison of the alkali-labile phosphate method (ALP) and a species-specific immunoassay (ELISA).

Altered concentration of the vertebrate yolk protein precursor vitellogenin is a recognized biomarker for endocrine disruption in fish, and within recent years yolk protein alteration has also been associated with endocrine disruption in bivalves. Species-specific, direct and sensitive methods for quantification of vitellogenin in fish have been available for years whereas bivalve yolk protein levels have been estimated indirectly by alkali-labile phosphate (ALP) liberated from high molecular weight proteins because the sequence and biochemical structure of most bivalve yolk proteins are unknown. By applying a species-specific enzyme-linked immunosorbent assay (ELISA) for accurate determination of yolk protein level the impact of 17β-estradiol (57, 164 and 512 ng/L) on the freshwater bivalve Unio tumidus was investigated and compared with ALP estimations.

Amount and metal composition of midgut gland metallothionein in shore crabs (Carcinus maenas) after exposure to cadmium in the food.

Accumulation of cadmium in aquatic invertebrates may compromise human food safety and anthropogenic additions of cadmium to coastal areas cause concern. Induction of crustacean metallothionein has been suggested as a useful biomarker for contamination of the aquatic environment with cadmium. We investigated how exposure to low concentrations of cadmium in the food affects the subcellular binding of cadmium with the shore crab Carcinus maenas as model organism.

Vitellogenin as biomarker for estrogenicity in flounder Platichthys flesus in the field and exposed to 17α-ethinylestradiol via food and water in the laboratory.

The ability of 17α-ethinylestradiol (EE2) to elevate vitellogenin levels were investigated in male flounder Platichthys flesus and vitellogenin concentrations in flounders from the Danish coastal environment were determined. Male flounders were exposed to 17α-ethinylestradiol (EE2) via food or water. Average vitellogenin concentrations in the control fish ranged between 25 and 100 ng mL(-)(1).

Genetic adaptation of earthworms to copper pollution: is adaptation associated with fitness costs in Dendrobaena octaedra?

Exposure to copper pollution affects reproduction, growth and survival of earthworms. It is known that earthworms can cope with high copper burdens, but the distinction between physiological acclimation and evolutionary heritable changes and associated fitness consequences of the adaption to long-term copper exposure has rarely been studied. To investigate adaptation of earthworm populations of Dendrobaena octaedra to copper contamination, three populations from polluted soil were studied and compared to three unpolluted reference sites.

Quantification of metallothionein by differential pulse polarography overestimates concentrations in crustaceans.

If metallothionein concentrations in invertebrates are to be used as biomarkers for metal contamination in the aquatic environment, it is imperative thatthe methods used for quantitative analysis are reliable. A review of the literature concerned with quantification of crustacean metallothionein shows that utilization of differential pulse polarography generally results in higher concentrations than any other method. The obvious discrepancies were investigated by experimental comparison of three different methods (enzyme linked immuno sorbent assay (ELISA), a spectrophotometric assay, differential pulse polarography) for determination of metallothionein concentrations in the shore crab Carcinus maenas.

Orally administered bisphenol a in rainbow trout (Oncorhynchus mykiss): estrogenicity, metabolism, and retention.

The estrogenic effect of orally administered bisphenol A (BPA) was investigated in a rainbow trout (Oncorhynchus mykiss) test system. Bisphenol A was administered orally to sexually immature rainbow trout every second day for up to 12 d in doses between 1.8 and 258 mg/kg every second day (/2d).

Distribution of the UV filter 3-benzylidene camphor in rat following topical application.

A straightforward analytical method for determination of 3-benzylidene camphor (3-BC) in rat adipose tissue, brain, liver, muscle, plasma and testis following topical application was developed and validated. Three exposure levels (60, 180 and 540 mg kg(-1) day(-1)) were tested for 65 days in male Sprague-Dawley rats (24 days postnatal). Sample preparation involving homogenization and n-heptane or methanol extraction of the tissue was applied before injection into the LC-ESI-MS-MS system.

Cadmium in the shore crab Carcinus maenas: seasonal variation in cadmium content and uptake and elimination of cadmium after administration via food.

The uptake and assimilation efficiency of cadmium administered via the food in the shore crab Carcinus maenas were investigated together with elimination kinetics and seasonal variations in cadmium content. The majority of shore crabs assimilated between 41 and 86% of the cadmium administered in their food. More than 90% of the cadmium taken up from food was retained in midgut gland.

Estrogenic effect of propylparaben (propylhydroxybenzoate) in rainbow trout Oncorhynchus mykiss after exposure via food and water.

The estrogenic effect of propylparaben was investigated in a rainbow trout Oncorhynchus mykiss test system. Propylparaben was administered orally to sexually immature rainbow trout every second day for up to 10 days in doses between 7 and 1830 mg kg(-1) 2 d(-1) and in the water at 50 and 225 microg l(-1) for 12 days. Plasma vitellogenin was measured before and during the exposures and the concentrations of propylparaben in liver and muscle were determined at the end of experiments.

Estrogenic effect of dietary 4-tert-octylphenol in rainbow trout (Oncorhynchus mykiss).

The estrogenic effect of dietary 4-tert-octylphenol (octylphenol) in rainbow trout Oncorhynchus mykiss was investigated. Octylphenol was administered orally to sexually immature rainbow trout every second day for 11 days in doses between 0.4 and 50 mgkg(-1)2 d(-1).