Evaluating Complex Mixtures in the Zebrafish Embryo by Reconstituting Field Water Samples: A Metal Pollution Case Study.

Accurately assessing the toxicity of complex, environmentally relevant mixtures remains an important challenge in ecotoxicology. The goal was to identify biological effects after exposure to environmental water samples and to determine whether the observed effects could be explained by the waterborne metal mixture found in the samples. Zebrafish embryos were exposed to water samples of five different sites originating from two Flemish (Mol and Olen, Belgium) metal contaminated streams: "Scheppelijke Nete" (SN) and "Kneutersloop" (K), and a ditch (D), which is the contamination source of SN.

Prioritization of contaminated watercourses using an integrated biomarker approach in caged carp.

Because of the ever increasing complexity of environmental contamination profiles, there are limitations to the use of analytical pollutant measurements for monitoring and prioritization of watercourses. The potential of biomarkers has been debated for many years, especially in laboratory settings, but there is a need for studies evaluating these approaches in the field. We evaluated the usefulness of a selection of biomarkers, mostly indicators of general physiological status and common stress responses such as oxidative stress, to discriminate among environmental pollution profiles, with the aim of prioritizing contaminated watercourses for targeted remediation efforts.

Optimisation of the bovine whole in vitro embryo system as a sentinel for toxicity screening: a cadmium challenge.

Developmental toxicity testing could greatly benefit from the availability of an in vitro alternative model based on the use of animal embryos that have better human-like physiology than the currently-used alternative models. These current models are insufficient, as extrapolation of the results can be challenging. Therefore, an in vitro bovine embryo culture system was used to expose individual morulae to test substances, and to study developmental characteristics up to the blastocyst stage.

Deiodinase knockdown during early zebrafish development affects growth, development, energy metabolism, motility and phototransduction.

Thyroid hormone (TH) balance is essential for vertebrate development. Deiodinase type 1 (D1) and type 2 (D2) increase and deiodinase type 3 (D3) decreases local intracellular levels of T3, the most important active TH. The role of deiodinase-mediated TH effects in early vertebrate development is only partially understood.

PFOS affects posterior swim bladder chamber inflation and swimming performance of zebrafish larvae.

Perfluorooctane sulphonate (PFOS) is one of the most commonly detected perfluorinated alkylated substances in the aquatic environment due to its persistence and the degradation of less stable compounds to PFOS. PFOS is known to cause developmental effects in fish. The main effect of PFOS in zebrafish larvae is an uninflated swim bladder.

Characterisation of perfluorooctane sulfonate (PFOS) in a terrestrial ecosystem near a fluorochemical plant in Flanders, Belgium.

Bioaccumulation of perfluorooctane sulfonate (PFOS) in a restricted terrestrial food chain was investigated with the omnivorous wood mouse (Apodemus sylvaticus) on top of the studied food chain. The levels detected are very high compared with literature as a result of the presence of fluorochemical plant in the immediate vicinity of the study area. Soil, surface water, fruits of European elder and common blackberry, invertebrates, bank vole and wood mouse were collected at two sites, e.

Mechanistic toxicity study of perfluorooctanoic acid in zebrafish suggests mitochondrial dysfunction to play a key role in PFOA toxicity.

The aquatic environment is an important site for perfluorooctanoic acid (PFOA) deposit. Nevertheless, the exact mode of action and its resulting toxicological effects in aquatic organisms remain largely unknown. To gain a better understanding of the mode of action of teleost PFOA toxicity, transcriptomics, proteomics, biochemical parameters and reproduction were integrated in this study.

Hypothermal and hyperthermal acclimation differentially modulate cadmium accumulation and toxicity in the zebrafish.

Despite the fact that aquatic organisms are mostly poikilothermic and environmental temperature variations can have considerable impact on chemical toxicity, toxicity studies are mainly performed at the species' specific standard or optimal temperature. Since the zebrafish is a recommended test species for use in toxicity tests, we investigated the temperature dependence of 96 h cadmium accumulation and toxicity in zebrafish acclimated to 18, 26, 30 or 34°C. Zebrafish showed high cadmium tolerance with acute 96 h LC50 values of 121.

Temperature dependence of long-term cadmium toxicity in the zebrafish is not explained by liver oxidative stress: evidence from transcript expression to physiology.

Standard ecotoxicity tests are performed at species' specific standard temperatures, but temperature is known to affect chemical toxicity. A temperature increase has been shown to increase cadmium toxicity in several aquatic species but information in fish is scarce. Based on literature we hypothesize that with increasing temperature, cadmium accumulation and oxidative stress increase, resulting in increased toxicity.

Assessing the impact of thermal acclimation on physiological condition in the zebrafish model.

The zebrafish has become a valuable vertebrate model organism in a wide range of scientific disciplines, but current information concerning the physiological temperature response of adult zebrafish is rather scarce. In this study, zebrafish were experimentally acclimated for 28 days to 18, 26 or 34 °C and a suite of non-invasive and invasive methods was applied to determine the thermal dependence of zebrafish physiological condition. With decreasing temperature, the metabolic rate of zebrafish decreased, as shown by the decreasing oxygen uptake and ammonia excretion rates, limiting the critical swimming speed, probably due to a decreased muscle fibre power output.

The structure of the fire fighting foam surfactant Forafac®1157 and its biological and photolytic transformation products.

For several decades, perfluorooctane sulfonate (PFOS) has widely been used as a fluorinated surfactant in aqueous film forming foams used as hydrocarbon fuel fire extinguishers. Due to concerns regarding its environmental persistence and toxicological effects, PFOS has recently been replaced by novel fluorinated surfactants such as Forafac®1157, developed by the DuPont company. The major component of Forafac®1157 is a 6:2 fluorotelomer sulfonamide alkylbetaine (6:2 FTAB), and a link between the trade name and the exact chemical structure is presented here to the scientific community for the first time.

The search for alternative aqueous film forming foams (AFFF) with a low environmental impact: physiological and transcriptomic effects of two Forafac(®) fluorosurfactants in turbot.

Fluorosurfactants are the key components in aqueous film forming foams (AFFF). They provide these fire fighting agents with the required low surface tension and they enable film formation on top of lighter fuels to prevent burn back. Development of effective and environmentally acceptable PFOS alternatives is one of the most important priorities in the fire fighting foam industry.

Impact of a perfluorinated organic compound PFOS on the terrestrial pollinator Bombus terrestris (Insecta, Hymenoptera).

Perfluorinated organic chemicals like perfluorooctane sulfonic acid (PFOS) are persistent environmental pollutants that have been measured in a great diversity of wildlife worldwide, especially in the aquatic compartment. However, little information is available on the presence and effects of PFOS in the terrestrial compartment. Therefore, we investigated in this project the risks for effects, bioaccumulation and potential mechanisms of activity of PFOS in the bumblebee Bombus terrestris L.

Structure-activity relationship assessment of four perfluorinated chemicals using a prolonged zebrafish early life stage test.

Perfluorinated compounds (PFCs) are a group of anthropogenic chemicals containing diverse functional groups and chain lengths. They are known to be persistent and bioaccumulative explaining their worldwide environmental presence. The toxicological information on these chemicals is still incomplete and insufficient to assess their environmental impact and structure-activity relationship.

Do repeated runs of a cell saver device increase the pro-inflammatory properties of washed blood?

Objective: Intra-operative cell salvage is increasingly used, especially in longer cases with continuing blood loss. However it is unknown if the quality of processed blood is affected when larger quantities of blood are processed. We hypothesized that the quality of the washed blood decreases after multiple runs.

Toxicity evaluation of perfluorooctane sulfonate (PFOS) in the liver of common carp (Cyprinus carpio).

Perfluorooctane sulfonate (PFOS) has been manufactured for over 50 years in increasing quantities and has been used for several industrial and commercial aims. Due to persistence and bioaccumulation of this pollutant, it can be found worldwide in wildlife and humans. Biochemical effects of PFOS exposure are mainly studied in mammalian model species and information about effects on fish species remain largely scarce.

Recombinant factor VIIa in orthotopic liver transplantation: influence on parameters of coagulation and fibrinolysis.

The effect of recombinant factor VIIa (rFVIIa) on blood loss was evaluated in cirrhotic patients undergoing orthotopic liver transplantation. In the present study, we explored the effect of rFVIIa on coagulation and fibrinolysis during orthotopic liver transplantation. Coagulation factors, parameters of thrombin generation and parameters of fibrinolysis were measured in six patients who had received a single dose of 80 micro g/kg rFVIIa and in ten controls, during and after orthotopic liver transplantation.

Reduced transfusion requirements by recombinant factor VIIa in orthotopic liver transplantation: a pilot study.

Background: Large transfusion requirements, i.e., excessive blood loss, during orthotopic liver transplantation (OLT) are correlated with increased morbidity and mortality.

Adverse obstetric outcome in low- and high- risk pregnancies: predictive value of maternal serum screening.

Objective: To determine whether the relationship between adverse pregnancy outcome and elevated maternal serum alpha-fetoprotein (MSAFP) and/or maternal serum hCG levels in women whose fetuses have no chromosomal abnormalities or neural tube defects is restricted to pregnancies with a priori elevated risk for pathology or also present in low-risk pregnancies.

Methods: The outcomes of pregnancy in two groups of patients with elevated MSAFP and/or maternal serum hCG values were compared with the outcomes of a reference group with normal serum values. The first study group consisted of 83 women without pre-existing risk for poor outcome as defined by the guidelines of the Dutch Society of Obstetrics and Gynecology.

Maternal serum alpha-fetoprotein in fetal anal atresia and other gastro-intestinal obstructions.

The fetal gastro-intestinal (GI) tract contributes to alpha-fetoprotein (AFP) levels in amniotic fluid and hence to those in maternal serum (MS). This study retrospectively analysed results of second trimester MSAFP screening in cases of fetal GI tract obstruction. 18 cases of fetal GI obstruction were diagnosed amongst 17,036 women who underwent MSAFP screening between 1979 and 1997: seven had oesophageal atresia, four had duodenal atresia, six had anal atresia, and one had both anal and oesophageal atresia.

[Maternal serum screening for Down syndrome and neural tube defects].

Objective: Evaluation of maternal serum screening for Down's syndrome (DS) and neural tube defects (NTDs).

Design: Longitudinal study.

Setting: Department of Obstetrics and Gynaecology, University Hospital Utrecht, the Netherlands.

The effect of chorionic villus sampling on the number of fetal cells isolated from maternal blood and on maternal serum alpha-fetoprotein levels.

Fetal cells are present in the circulation of pregnant women and can be isolated using density gradient centrifugation and magnetic cell sorting. In the present study, maternal cell preparations were depleted for CD45- and CD14-positive cells and enriched for CD71-positive cells. The number of fetal nucleated cells was determined using fluorescence in situ hybridization for X and Y chromosomes.

Are Down syndrome fetuses detected through maternal serum screening similar to those remaining undetected?

This study was designed to examine whether fetuses with Down syndrome (DS) identified through serum screening are different from those whose mothers have normal serum screening results. It was a retrospective follow-up study of pregnancies where maternal serum alpha-fetoprotein (MSAFP) concentrations were measured to identify women at increased risk of having a baby with a neural tube defect (NTD). An enhanced risk for NTD was the only reason for intervention in the screened population.

Fetal ductus venosus flow velocity waveforms and maternal serum AFP before and after first-trimester transabdominal chorionic villus sampling.

Doppler flow velocity waveform recording in the fetal ductus venosus and umbilical artery as well as maternal blood sampling for serum alpha-fetoprotein (MSAFP) was performed before and after transabdominal chorion villus sampling (TACVS) in 36 women of advanced maternal age (> or = 36 years). Gestational age ranged between 11 and 13 weeks. No chromosomal anomaly was detected.

Effects of a dietary load of acid or base on changes induced by lactose in rats.

Feeding lactose or other slowly digestible carbohydrates to adult mammals may induce a variety of effects including hyperplasia and neoplasia. The most fundamental effect probably is the increased production in the large intestine of short-chain fatty acids (SCFA) resulting from increased fermentation of carbohydrate residues. To find out whether the increased production of these acidic compounds is involved in the induction of certain alterations caused by low-digestibility carbohydrates, the modifying effects of an acidifying (NH4Cl) or an alkalizing (KHCO3) diet supplement on lactose-induced changes in rats were studied.