Seasonal variation in cotyledoside concentration of Tylecodon wallichii (Harv.) Tolken subsp. wallichii sampled in a krimpsiekte-prevalent region

Krimpsiekte, an economically important neuromuscular affliction of small stock, follows upon ingestion of certain members of the Crassulaceae (plakkies) containing cumulative neurotoxic bufadienolides. Tylecodon wallichii (Harv.) Tolken subsp. wallichii is probably the most important species of the group of plants causing krimpsiekte. The growing tip of the stem and various other plant parts of T. wallichii, when available, were collected monthly. The seasonal variation in cotyledoside content of the plant was measured. Cotyledoside concentration was determined by high performance liquid chromatographic-electrospray mass spectrometry analysis (HPLC-ESMS). The cotyledoside concentration in the plant stems fluctuated substantially during the year, but tended to be higher in the cold winter months and increased again in the spring and early summer. Elevated plant stem concentrations corresponded with natural field outbreaks of krimpsiekte, which usually occur during the winter to early summer. The highest cotyledoside concentrations were detected in the flowering stalk. Cotyledoside was not the only component of this type in the plant, as mass spectrometry revealed the presence of other, possibly related, compounds.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat v.9 was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201

In-house validation of a liquid chromatography tandem mass spectrometry method for the analysis of lipophilic marine toxins in shellfish using matrix-matched calibration

A liquid chromatography tandem mass spectrometry (LC-MS/MS) method for the quantitative analysis of lipophilic marine toxins in shellfish extracts (mussel, oyster, cockle and clam) was validated in-house using European Union (EU) Commission Decision 2002/657/EC as a guideline. The validation included the toxins okadaic acid (OA), yessotoxin (YTX), azaspiracid-1 (AZA1), pectenotoxin-2 (PTX2) and 13-desmethyl spirolide-C (SPX1). Validation was performed at 0.5, 1 and 1.5 times the current EU permitted levels, which are 160 µg kg-1 for OA, AZA1 and PTX2 and 1,000 µg kg-1 for YTX. For SPX1, 400 µg kg-1 was chosen as the target level as no legislation has been established yet for this compound. The method was validated for determination in crude methanolic shellfish extracts and for extracts purified by solid-phase extraction (SPE). Extracts were also subjected to hydrolysis conditions to determine the performance of the method for OA and dinophysistoxin esters. The toxins were quantified against a set of matrix-matched standards instead of standard solutions in methanol. To save valuable standard, methanolic extract instead of the homogenate was spiked with the toxin standard. This was justified by the fact that the extraction efficiency is high for all relevant toxins (above 90%). The method performed very well with respect to accuracy, intraday precision (repeatability), interday precision (within-laboratory reproducibility), linearity, decision limit, specificity and ruggedness. At the permitted level the accuracy ranged from 102 to 111%, the repeatability from 2.6 to 6.7% and the reproducibility from 4.7 to 14.2% in crude methanolic extracts. The crude extracts performed less satisfactorily with respect to the linearity (less than 0.990) and the change in LC-MS/MS sensitivity during the series (more than 25%). SPE purification resulted in greatly improved linearity and signal stability during the series. Recently the European Food Safety Authority (EFSA) has suggested that to not exceed the acute reference dose the levels should be below 45 µg kg-1 OA equivalents and 30 µg kg-1 AZA1 equivalents. A single-day validation was successfully conducted at these levels. If the regulatory levels are lowered towards the EFSA suggested values, the official methods prescribed in legislation (mouse and rat bioassay) will no longer be sensitive enough. The validated LC-MS/MS method presented has the potential to replace these animal tests

Bioaccumulation of selected veterinary medicinal products (VMPs) in the blue mussel (Mytilus edulis)

Embargo until 15 November 2020Veterinary medicinal products (VMPs) are widely used within the fish farming industry to control sea lice infestations. There is concern that wild and farmed mussels in the vicinity to these fish farms may be exposed and subsequently bioaccumulate these chemicals, which could pose a threat to human health. To understand the fate of these chemicals in the environment, controlled laboratory exposures were performed to establish the uptake and depuration of selected VMPs in the blue mussel (Mytilus edulis). The VMPs included teflubenzuron, emamectin benzoate and deltamethrin. The effects of salinity on the bioaccumulation of teflubenzuron were also investigated to see whether mussels in brackish waters exhibit different bioaccumulation dynamics. Salinity had no significant effect on the uptake or depuration curves for teflubenzuron down to 15‰. The uptake rate constants (k1) for teflubenzuron, emamectin benzoate and deltamethrin in mussels were 192, 4.82 and 2003, with kinetic bioconcentration factors (BCFs) of 1304, 49 and 2516. Depuration rate constants (k2) were also found to differ between the three VMPs at 0.147, 0.048 and 0.796 for teflubenzuron, emamectin benzoate and deltamethrin, with calculated elimination half-lives (t1/2)of 4.7, 14 and 0.87 days. The longer elimination half-lives for teflubenzuron and emamectin benzoate, suggest that these chemicals accumulate in blue mussels and therefore have the potential to bioaccumulate in wild and farmed mussel populations in the environment.acceptedVersio

Toxicokinetics of cotyledoside following intravenous administration to sheep

Cotyledoside, a bufadienolide cardiac glycoside, was administered intravenously to sheep in 2 studies. In experiment 1, sheep (n = 4) received 0.0135 mg / kg daily on 5 consecutive days and in the 2nd experiment, sheep (n = 4) received 0.027 mg / kg as a single dose. Jugular blood was collected at different time intervals and kinetic parameters were determined. The data fitted a 1-compartmental model. In both experiments a short half-life (t1/2) and mean residence time (MRT), a relative small volume of distribution (Vdss) and rapid clearance were calculated. In the 1st experiment, t1/2 and MRT increased significantly (P < 0.007) from Day (D) 0 to D 4. It is suggested that the rapid decline in plasma cotyledoside concentrations in sheep denotes rapid distribution of cotyledoside to the tissues or extracellular spaces and possible accumulation at the biophase

Vitellogenin in African Sharptooth Catfish (Clarias gariepinus): Purification, Characterization, and Elisa Development

Journal of Toxicology and Environmental Health, Part A 2009, 72: 173–183Vitellogenin (Vtg) induction in African sharptooth catfish (Clarias gariepinus) was assessed in order to develop a method for monitoring estrogenic pollution in African freshwater systems. Clarias gariepinus Vtg (Cg-Vtg) was purified from serum obtained from 17a-ethynylestradiol (EE2)-exposed fish and polyclonal antibodies against Cg-Vtg were raised. An enzyme-linked immunosorbent assay (ELISA) was developed and the induction and kinetics of Vtg were assessed in male fish in three different exposure trials using both natural estrogen (17a-estradiol [E2]) and synthetic EE2. Concentrations of EE2 in water and levels of EE2 conjugates in bile were quantified by liquid chromatography– mass spectrometry (LC-MS). In addition, co-administration of E2 and benzo[a]pyrene (BaP) were studied. Vtg was induced in all exposure trials and the maximum induction was observed 1 wk after exposure. Exposure of male C. gariepinus to 1.4, 2.7, and 13.9 mg/ml EE2 induced Vtg synthesis at all concentrations. BaP did not influence the Vtg kinetics. However, an increased rate of biliary excretion of EE2 was observed when BaP was additionally administered. In conclusion, Vtg is induced in male C. gariepinus after exposure to both E2 and EE2, rendering it a suitable biomarker for endocrine-disrupting chemicals in African freshwater systems

IMPROVING HYBRID III INJURY ASSESSMENT IN STEERING WHEEL RIM TO CHEST IMPACTS USING RESPONSES FROM FINITE ELEMENT HYBRID III AND HUMAN BODY MODEL

Objective: The main aim of this study was to improve the quality of injury risk assessments in steering wheel rim to chest impacts when using the Hybrid III crash test dummy in frontal heavy goods vehicle (HGV) collision tests. Correction factors for chest injury criteria were calculated as the model chest injury parameter ratios between finite element (FE) Hybrid III, evaluated in relevant load cases, and the Total Human Model for Safety (THUMS). This is proposed to be used to compensate Hybrid III measurements in crash tests where steering wheel rim to chest impacts occur.Methods: The study was conducted in an FE environment using an FE-Hybrid III model and the THUMS. Two impactor shapes were used, a circular hub and a long, thin horizontal bar. Chest impacts at velocities ranging from 3.0 to 6.0m/s were simulated at 3 impact height levels. A ratio between FE-Hybrid III and THUMS chest injury parameters, maximum chest compression C-max, and maximum viscous criterion VCmax, were calculated for the different chest impact conditions to form a set of correction factors. The definition of the correction factor is based on the assumption that the response from a circular hub impact to the middle of the chest is well characterized and that injury risk measures are independent of impact height. The current limits for these chest injury criteria were used as a basis to develop correction factors that compensate for the limitations in biofidelity of the Hybrid III in steering wheel rim to chest impacts.Results: The hub and bar impactors produced considerably higher C-max and VCmax responses in the THUMS compared to the FE-Hybrid III. The correction factor for the responses of the FE-Hybrid III showed that the criteria responses for the bar impactor were consistently overestimated. Ratios based on Hybrid III and THUMS responses provided correction factors for the Hybrid III responses ranging from 0.84 to 0.93. These factors can be used to estimate C-max and VCmax values when the Hybrid III is used in crash tests for which steering wheel rim to chest interaction occurs.Conclusions: For the FE-Hybrid III, bar impacts caused higher chest deflection compared to hub impacts, although the contrary results were obtained with the more humanlike THUMS. Correction factors were developed that can be used to correct the Hybrid III chest responses. Higher injury criteria capping limits for steering wheel impacts are acceptable. Supplemental materials are available for this article. Go to the publisher\u27s online edition of Traffic Injury Prevention to view the supplemental file

IMPROVING HYBRID III INJURY ASSESSMENT IN STEERING WHEEL RIM TO CHEST IMPACTS USING RESPONSES FROM FINITE ELEMENT HYBRID III AND HUMAN BODY MODEL

Objective: The main aim of this study was to improve the quality of injury risk assessments in steering wheel rim to chest impacts when using the Hybrid III crash test dummy in frontal heavy goods vehicle (HGV) collision tests. Correction factors for chest injury criteria were calculated as the model chest injury parameter ratios between finite element (FE) Hybrid III, evaluated in relevant load cases, and the Total Human Model for Safety (THUMS). This is proposed to be used to compensate Hybrid III measurements in crash tests where steering wheel rim to chest impacts occur.Methods: The study was conducted in an FE environment using an FE-Hybrid III model and the THUMS. Two impactor shapes were used, a circular hub and a long, thin horizontal bar. Chest impacts at velocities ranging from 3.0 to 6.0m/s were simulated at 3 impact height levels. A ratio between FE-Hybrid III and THUMS chest injury parameters, maximum chest compression C-max, and maximum viscous criterion VCmax, were calculated for the different chest impact conditions to form a set of correction factors. The definition of the correction factor is based on the assumption that the response from a circular hub impact to the middle of the chest is well characterized and that injury risk measures are independent of impact height. The current limits for these chest injury criteria were used as a basis to develop correction factors that compensate for the limitations in biofidelity of the Hybrid III in steering wheel rim to chest impacts.Results: The hub and bar impactors produced considerably higher C-max and VCmax responses in the THUMS compared to the FE-Hybrid III. The correction factor for the responses of the FE-Hybrid III showed that the criteria responses for the bar impactor were consistently overestimated. Ratios based on Hybrid III and THUMS responses provided correction factors for the Hybrid III responses ranging from 0.84 to 0.93. These factors can be used to estimate C-max and VCmax values when the Hybrid III is used in crash tests for which steering wheel rim to chest interaction occurs.Conclusions: For the FE-Hybrid III, bar impacts caused higher chest deflection compared to hub impacts, although the contrary results were obtained with the more humanlike THUMS. Correction factors were developed that can be used to correct the Hybrid III chest responses. Higher injury criteria capping limits for steering wheel impacts are acceptable. Supplemental materials are available for this article. Go to the publisher\u27s online edition of Traffic Injury Prevention to view the supplemental file

Vitellogenin in African Sharptooth Catfish (Clarias gariepinus): Purification, Characterization, and Elisa Development

Journal of Toxicology and Environmental Health, Part A 2009, 72: 173–183Vitellogenin (Vtg) induction in African sharptooth catfish (Clarias gariepinus) was assessed in order to develop a method for monitoring estrogenic pollution in African freshwater systems. Clarias gariepinus Vtg (Cg-Vtg) was purified from serum obtained from 17a-ethynylestradiol (EE2)-exposed fish and polyclonal antibodies against Cg-Vtg were raised. An enzyme-linked immunosorbent assay (ELISA) was developed and the induction and kinetics of Vtg were assessed in male fish in three different exposure trials using both natural estrogen (17a-estradiol [E2]) and synthetic EE2. Concentrations of EE2 in water and levels of EE2 conjugates in bile were quantified by liquid chromatography– mass spectrometry (LC-MS). In addition, co-administration of E2 and benzo[a]pyrene (BaP) were studied. Vtg was induced in all exposure trials and the maximum induction was observed 1 wk after exposure. Exposure of male C. gariepinus to 1.4, 2.7, and 13.9 mg/ml EE2 induced Vtg synthesis at all concentrations. BaP did not influence the Vtg kinetics. However, an increased rate of biliary excretion of EE2 was observed when BaP was additionally administered. In conclusion, Vtg is induced in male C. gariepinus after exposure to both E2 and EE2, rendering it a suitable biomarker for endocrine-disrupting chemicals in African freshwater systems

Miljøgifter i norske kystområder 2018

Revised version of 7412-2019 / M-1515This programme examines the levels, trends and effects of contaminants in biota along the coast of Norway. The 2018-investigation included analyses of more than 133 different contaminants or biological effect parameters in five species (blue mussel, dogwhelk, common periwinkle, cod and the common eider). The contaminants include metals (Hg, Cd, Pb, Cu, Zn, Ag, As, Ni, Cr and Co), tributyltin (TBT), organochlorines (e.g. PCBs (PCB-7), DDT), PAHs, polybrominated diphenyl ethers (PBDEs), and perfluorinated alkylated substances (PFAS), as well as contaminants that have recently received much attention such as hexabromocyclododecane (HBCDs), chlorinated paraffins (SCCP, MCCP), bisphenol A (BPA), tetrabrombisphenol A (TBBPA), alkyphenols, siloxanes (D4, D5 and D6) and dechlorane plus. Biological effects parameters included VDSI, OH-pyrene metabolites, ALA-D and EROD. In the report, 30 representative substances or parameters were chosen for analyses of 713 time series (last 10 years). Of these there were statistically significant trends in 102 cases: 79 were downwards and 23 upwards. The upward trends were also associated with metals (78.3 %), primarily Hg (17.4 %).The dominance of downward trends indicated that contamination is decreasing for the measured substances. The downwards trends for TBT-concentrations and effect parameter (VDSI) confirmed that the legislation banning the use of TBT has been effective. Of the 2018-medians (last year) for all 713 time series, there were 323 cases that could be classified against EQS, of which 203 (62.8 %) were below the EQS and 120 (37.2 %) were above the EQS. Of the 2018-medians for the 713 time series, 641 cases could be classified using Norwegian provisional high reference contaminant concentrations (PROREF). Of these, 463 were below PROREF and 173 exceeded PROREF: 117 by a factor of less than two, 45 by a factor between two and five, eight by a factor between five and 10, four by a factor between 10 and 20, and four by a factor greater than 20. Some cases warrant special concern, such as high concentrations of several organic contaminants in cod liver from the Inner Oslofjord. High concentrations of DDE in mussels from the Sørfjord were related to earlier use of DDT as pesticide in orchards along the fjord. Concentrations of an expanded list of PFAS in cod liver from the Inner Oslofjord sampled since 1990 are presented. Results of analyses of stable isotopes of carbon and nitrogen are presented to investigate the role of food origin and trophic levels for observed contaminant concentrations.The Norwegian Environmental AgencypublishedVersio

Extraction of microalgal toxins by large-scale pumping of seawater in Spain and Norway, and isolation of okadaic acid and dinophysistoxin-2.

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