Efficacy and toxicity of praziquantel in helminth-infected barbel (Barbus barbus L.).

This study evaluated efficacy and toxicity of the pyrazinoisoquinoline anthelmintic praziquantel (PZQ) in barbel infected with metacercariae of Diplostomum spathaceum and adult Pomphorhynchus laevis, and assessed antioxidant biomarkers and the lipid peroxidation response in juvenile barbel post-treatment. The estimated 96-hr LC50 of PZQ was 28.6 mg/L. For evaluation of efficacy, barbel naturally infected with D. spathaceum were exposed to a 10 and 20 mg/L PZQ 4-day bath treatment. Both concentrations were 100% effective against D. spathaceum and significantly (p < .01) affected the activity of catalase, superoxide dismutase, glutathione reductase and glutathione-S-transferase as well as levels of reduced glutathione in liver and muscle. The efficacy of orally administered PZQ was assessed in adult barbel naturally infected with P. laevis. Fish were administered 10, 30 and 50 mg/kg of body weight and examined via gut dissection after 6 days. The 50 mg/kg dose significantly decreased the intensity of infection. Praziquantel is a feasible bath treatment for barbel infected with D. spathaceum and has potential for oral treatment of broodfish infected with P. laevis.

Use of biometric, hematologic, and plasma biochemical variables, and histopathology to assess the chronic effects of the herbicide prometryn on Common Carp.

BACKGROUND: Effects of acute and subchronic exposure of fish to s-triazine herbicides have been well documented, but data on the effects of prometryn on blood analytes in carp at environmentally realistic concentrations are lacking. OBJECTIVE: The objective of the study was to determine whether biometrics, blood analytes, and histopathology could serve as bioindicators in fish living in waters polluted by triazine. METHODS: Fish were exposed to prometryn at concentrations of 0.51 (reported concentration in Czech rivers), 8.0, and 80 µg/L for 14, 30, and 60 days. Prior to and during this period, biometrics, blood analytes, and histopathology were evaluated. RESULTS: After 60 days' exposure to 8.0 and 80 µg/L of prometryn, spleen weights (P < .05) and lactate (P < .01) levels were significantly lower, and concentrations of HGB (P < .01) and MHC (P < .01) and MCHC (P < .01) were higher, relative to controls. After 30 and 60 days' exposure to 0.51, 8.0, and 80 µg/L of prometryn, AST activity, calcium, magnesium, and inorganic phosphate levels were lower (P < .01), while creatinine concentration and ALT activity were higher (P < .01) than in controls. Glucose was higher after exposure to 80 µg/L after 30 and 60 days, and after 60 days' exposure to 8.0 µg/L. Renal histology revealed severe hyaline degeneration of the epithelial cells of caudal kidney tubules in fish at all exposure levels. CONCLUSIONS: This study shows effects in fish blood at a concentration of 0.51 µg/L of prometryn, a significant finding in view of prometryn reaching a maximum of 4.4 µg/L or less in European rivers. Select blood analytes, such as creatinine, and histologic changes in caudal kidney are potential biomarkers for monitoring residual triazine pesticides in Common Carp.

Effects of long-term exposure to simazine in real concentrations on common carp (Cyprinus carpio L.).

The effects of a 90 day simazine exposure at concentrations of 0.06 (reported concentration in Czech rivers), 1, 2, and 4 µg L⁻¹ were assessed in one-year-old common carp (Cyprinus carpio L.). Its influence on biometric parameters, hematology, blood biochemistry, liver biomarkers, and histology was investigated. Biometric parameters of common carp exposed to simazine at 0.06 µg L⁻¹ showed no differences from untreated fish. Simazine concentrations of 1, 2, and 4 µg L⁻¹ caused significant (p<0.01) increase of hepatosomatic indices relative to controls. Hematological profiles showed significant (p<0.01) decrease in leukocyte count relative to controls at all concentrations. Biochemical profiles of common carp exposed to simazine at all concentrations showed significant (p<0.01) increase in activity of alkaline phosphatase. In addition, at concentrations of 1 and 2 µg L⁻¹, there was a significant increase in alanine aminotransferase (p<0.05), and, at 4 µg L⁻¹, a significant increase in total protein (p<0.05), albumins (p<0.05), and alanine aminotransferase (p<0.05) compared with controls. Renal histology revealed severe hyaline degeneration of the epithelial cells of caudal kidney tubules in fish at all exposure levels compared to controls. Chronic exposure of common carp to simazine caused significant shifts in hematological, biochemical, and biometric profiles, and histopathological changes. The results of this study indicate that chronic exposure of simazine has altered multiple physiological indices in fish hematology and biochemistry, which potentially may be a biomarker of simazine toxicity; however, before these parameters are used as special biomarkers for monitoring residual simazine in aquatic environment, more detailed experiments in laboratory need to be performed in the future.

Post-release growth and dispersal of pond and hatchery-reared European grayling Thymallus thymallus compared with their wild conspecifics in a small stream.

The growth, and dispersal of stocked European grayling Thymallus thymallus, reared in a hatchery (fed dry food pellets) or in a pond (fed natural food), compared with their wild conspecifics was assessed from the recapture of individually tagged fish 168 days after their release into the Blanice River, Czech Republic. Recapture rates and site fidelity were higher for wild T. thymallus than for artificially reared fish. Specific growth rate and upstream or downstream dispersal did not significantly differ between any of the groups of fish. An influence of rearing conditions (pond v. hatchery) on the overall performance of stocked fish was not demonstrated. Initially, lower condition factors of reared T. thymallus were equal to wild fish after recapture, suggesting adaptation of artificially reared fish that remained in the sections studied.

Effects of sub-chronic exposure to terbutryn in common carp (Cyprinus carpio L.).

The sub-chronic effects of terbutryn at concentrations 0.02 (reported concentration in Czech rivers), 4, 20, and 40 microg L(-1) were assessed in one-year-old common carp (Cyprinus carpio L.) exposed for 28 days and compared to a non-treated control group. Its influence on biometric parameters, hematology, blood biochemistry, and histology was investigated. Exposure to terbutryn at 0.02 microg L(-1) showed no observable effect, whereas exposure to 4, 20, and 40 microg L(-1) showed significantly higher erythrocyte counts, ammonia levels, aspartate aminotransferase, lactate dehydrogenase, creatine kinase, and lactate, but significantly lower mean corpuscular volume, mean corpuscular hemoglobin, and creatine. Cell shape changes and lipid inclusions were found in hepatocytes, and there was destruction of caudal kidney tubules when compared to control fish.

Effects of acute exposure to metribuzin on some hematological, biochemical and histopathological parameters of common carp (Cyprinus carpio L.).

The aim of the study was to evaluate acute toxic effects of the preparation Sencor 70 WG (metribuzin 70% W/V) on hematological, biochemical indices and histology of the common carp (Cyprinus carpio L.). In carp exposed for 96 h to Sencor 70 WG in the concentration of 250.2 mg/L, showed significantly lower (p<0.01) values of plasma total proteins, albumins, total globulins, triacylglycerols, lactate dehydrogenase, lactate, inorganic phosphate, hematocrit, hemoglobin concentration, mean erythrocyte volume, the leucocrite value, lymphocyte, and significantly higher (p<0.01) values of glucose, ammonia, calcium, monocytes, neutrophile granulocytes, developmental forms myeloid sequence and basophiles compared to the control group. Histopathological examination revealed hyaline degeneration of the epithelial cells of renal tubules of the caudal kidney. This alteration of kidney resulted in hypoproteinemia, followed by generation of transudate in body cavity.

Effects of bifenthrin on some haematological, biochemical and histopathological parameters of common carp (Cyprinus carpio L.).

The aim of this study was to assess the effect of bifenthrin on common carp (Cyprinus carpio L.). The 96-h LC50 value of Talstar EC 10 (active substance 100 g l(-1) bifenthrin) was found to be 57.5 microg l(-1). Examination of haematological and biochemical profiles and histological tissue examination was performed on common carp after 96 h of exposure to Talstar EC 10 (57.5 microg l(-1)). The experimental group showed significantly higher (P < 0.01) values of plasma glucose, ammonia, aspartate aminotransferase and creatine kinase as well as the relative and absolute monocyte count, compared with the control group. Histological examination revealed teleangioectasiae of secondary gill lamellae and degeneration of hepatocytes. The bifenthrin-based Talstar EC 10 pesticide preparation was classified as a substance strongly toxic for fish.

Effects of pollution on chub in the River Elbe, Czech Republic.

The Elbe River is one of the most polluted aquatic ecosystems in the Czech Republic. The effect of three major chemical plants located on the Elbe River (at Pardubice, Neratovice, and Usti nad Labem) on fish was studied in 2004. Health status, chemical concentrations (Hg, PCB, DDT, HCH, HCB, OCS, 4-tert-nonylphenols, 4-tert-octylphenol) in muscle, and biomarkers (hepatic ethoxyresorufin-O-deethylase (EROD), plasma vitellogenin, and plasma 11-ketotestosterone) were assessed in male chub (Leuciscus cephalus L.). Differences between localities upstream (US) and downstream (DS) from the monitored source of pollution were identified. Fish from DS sampling sites showed significantly higher levels of contaminants than fish from US sampling sites. Generally, the concentrations of pollutants in fish from the Elbe sites were significantly higher compared to the reference site. Reduced gonad size, decreased plasma levels of 11-ketotestosterone, EROD and vitellogenin induction, and histopathologies of male gonads indicated harmful effects of aquatic pollution in fish from the Czech portion of the Elbe River.

Occurrence of 3-MCPD fatty acid esters in human breast milk.

A series of twelve breast milk samples were analysed by gas chromatography-mass spectrometry (GC/MS) operated in selected ion monitoring mode for 3-chloropropane-1,2-diol (3-MCPD). Whilst none of the samples contained 3-MCPD above the limit of detection of 3 microg kg(-1) milk, all contained high amounts of 3-MCPD esterified with higher fatty acids. The levels of 3-MCPD released by hydrolysis of these esters (bound 3-MCPD) ranged from the limit of detection (300 microg kg(-1), expressed on a fat basis) to 2195 microg kg(-1); with a mean level of bound 3-MCPD of 1014 microg kg(-1), which corresponded to 35.5 microg kg(-1) milk. The presence of bound 3-MCPD was confirmed using orthogonal gas chromatography coupled with high-speed time-of-flight mass spectrometry analysis for four randomly selected breast milk samples. Six breast milks collected from one of the nursing mothers 14-76 days after childbirth contained bound 3-MCPD within the range of 328-2078 microg kg(-1) fat (mean 930 microg kg(-1) fat). The calculated bound 3-MCPD content of these samples was within the range of 6 and 19 microg kg(-1) milk (mean of 12 microg kg(-1) milk). The major types of 3-MCPD esters were the symmetric diesters with lauric, palmitic, and oleic acids, and asymmetric diesters with palmitic acid/oleic acid among which 3-chloro-1,2-propanediol 1,2-dioleate prevailed.

Effects of deltamethrin on rainbow trout (Oncorhynchus mykiss).

The aim of this study was to assess the effect of deltamethrin on rainbow trout (Oncorhynchus mykiss). Control and experimental group of fish were exposed to Decis EW 50 pesticide preparation (active substance 50g/l of deltamethrin). The acute semistatical toxicity test lasting 96h was performed on rainbow trout juveniles. The 96hLC(50) value of Decis EW 50 was 0.02mg/l. Examination of haematological and biochemical profile and histological tissue examination was performed on 1-2-year-old rainbow trout after 96h of exposure to Decis EW 50 in a concentration of 0.02mg/l. The experimental group showed significantly lower values (p<0.05) of plasma glucose, alanine aminotransferase, cholinesterase and significantly higher (p<0.05) values of erythrocyte count, haemoglobin content, haematocrit and plasma total protein, albumins, ammonia, aspartate aminotransferase, creatinekinase and calcium compared to the control group. The deltamethrin-based Decis EW 50 pesticide preparation was classified among substances strongly toxic for fish.

Fatty acid esters of 3-chloropropane-1,2-diol in edible oils.

A series of 25 virgin and refined edible oils, obtained from retailers, was analyzed for levels of free 3-chloropropane-1,2-diol (3-MCPD) and 3-MCPD released from esters with higher fatty acids (bound 3-MCPD). Oils containing free 3-MCPD ranging from <3 microg kg-1 (LOD) to 24 microg kg-1. Surprisingly, bound 3-MCPD levels were much higher and varied between <100 (LOD) and 2462 microg kg-1. On average, virgin oils had relatively low levels of bound 3-MCPD, ranging from <100 (LOD) to <300 microg kg-1 (LOQ). Higher levels of bound 3-MCPD were found in oils from roasted oilseeds (337 microg kg-1) and in the majority of refined oils (<300-2462 microg kg-1), including refined olive oils. In general, it appears that the formation of bound 3-MCPD in oils is linked to preliminary heat treatment of oilseeds and to the process of oil refining. Analysis of unrefined, de-gummed, bleached, and deodorized rapeseed oil showed that the level of bound MCPD decreased during the refining process. However, additional heating of seed oils for 30 min at temperatures ranging from 100 to 280 degrees C, and heating at 230 degrees C (260 degrees C) for up to 8 h, led to an increase in bound 3-MCPD levels. On the other hand, heating of olive oil resulted in a decrease in bound 3-MCPD levels. For comparison, fat isolated from salami was analyzed for intact fatty acid esters of 3-MCPD. This fat contained bound 3-MCPD at a level of 1670 microg kg-1 and the fatty acid esters of 3-MCPD mainly consisted of 3-MCPD diesters; monoesters of 3-MCPD were present in smaller amounts. The major types of 3-MCPD diesters (about 85%) were mixed diesters of palmitic acid with C18 fatty acids (stearic, oleic, linoleic acids). These diesters were followed by 3-MCPD distearate (11%) and 3-MCPD dipalmitate (4%). Generally, very little 3-MCPD existed as the free compound (31 microg kg-1).

Occurrence of 3-chloro-propane-1,2-diol (3-MCPD) and related compounds in foods: a review.

A critical review of the occurrence of 3-chloro-propane-1,2-diol (3-MCPD) in foods not known to contain hydrolysed vegetable proteins is presented. The review covers the properties and chemistry of 3-MCPD and the current methods of analysis in foodstuffs. The results of UK surveys of 3-MCPD occurrence in both retail foods and commercial food ingredients are discussed with particular reference to cereal, meat and dairy products. The possible mechanisms for the formation and decay of 3-MCPD in foods are suggested. The review does not cover the detailed toxicology of 3-MCPD and its occurrence in hydrolysed vegetable proteins, which have been considered elsewhere, nor possible issues such as in-vivo formation.

Reactions of allyl isothiocyanate with alanine, glycine, and several peptides in model systems.

The nucleophilic addition reactions of allyl isothiocyanate (AITC) with alanine, glycine, and five alanine and/or glycine containing di- and tripeptides were investigated in model aqueous solutions of pH 6, 8, and 10 at 25 degrees C for 2-4 weeks. The formation of primary adducts, i.e., N-allylthiocarbamoyl amino acids (ATC-amino acids) or ATC-peptides, their transformation products, i.e., 3-allyl-2-thiohydantoins originating by cyclization of ATC-amino acids or by cleavage of ATC-peptides, and several other minor components were observed. The results revealed that both addition and cleavage rates rise proportionally to pH, whereas the formation of 2-thiohydantoins from ATC-amino acids is controlled by H(3)O(+) concentration. Depending on pH, differences in reaction rates of the additions are determined by either pK(a)(NH(2)) of amino compounds or electrical effects and steric hindrance of the molecules. The latter factors are crucial also for differences in cleavage rates of ATC-peptides. With regard to the pK(a) values and simultaneous AITC decomposition by aqueous nucleophiles, the reactions with amino acids and oligopeptides are predominant reaction pathways of AITC in solutions of pH 10 and 8, respectively. Reaction mechanism of the cleavage of 2-thiohydantoins from ATC-peptides in alkaline and mild acidic solutions is different from the conventional Edman scheme used for anhydrous acid medium.

Distribution of S-Alk(en)ylcysteine sulfoxides in some Allium species. Identification Of a new flavor precursor: S-ethylcysteine sulfoxide (Ethiin).

The content of S-alk(en)ylcysteine sulfoxides, important nonvolatile flavor precursors, was determined in 15 different Allium species by means of gas chromatography. The method employed is based on derivatization of S-alk(en)ylcysteine sulfoxides with ethyl chloroformate followed by their reduction with sodium iodide. The total content of S-alk(en)ylcysteine sulfoxides varied considerably in the wide range between 0.02 and 1.3% fresh weight. Not only the total content but also relative proportions of individual derivatives varied to a great extent. A novel S-alkylcysteine derivative, S-ethylcysteine sulfoxide (ethiin), not previously reported to occur in Allium species, was found in most of the samples examined in trace amounts. None of the other S-alk(en)ylcysteine sulfoxides, for example, isopropyl, (Z)-1-propenyl, butyl, or pentyl, were detected in any of the samples analyzed, limiting possible levels of each of these components to

Gas chromatographic determination of S-alk(en)ylcysteine sulfoxides.

A new GC method for determination of S-alk(en)ylcysteine sulfoxides, important secondary metabolites occurring in many plant genera, has been developed. The method is based on isolation of the amino acid fraction by ion-exchange chromatography followed by derivatization with ethyl chloroformate at ambient temperature and reduction of derivatized S-alk(en)ylcysteine sulfoxides by sodium iodide. The main advantages of the new method are its high sensitivity, excellent resolution capability, accuracy and reliability, as well as the possibility to identify unknown compounds by means of GC-MS. The content of alliin and other S-alk(en)ylcysteine sulfoxides was determined in nine different samples of garlic (Allium sativum L.) originating from the Czech Republic, France, and China. The total content of S-alk(en)ylcysteine sulfoxide pool ranged between 0.53 and 1.3% fresh weight, with S-allylcysteine sulfoxide (alliin) being predominant. A novel S-alkylcysteine derivative, S-ethylcysteine sulfoxide (ethiin), not previously reported to occur in Allium species, was found in some of the samples examined.

Volatile compounds thermally generated from S-propylcysteine and S-propylcysteine sulfoxide-aroma precursors of Allium vegetables.

Two nonvolatile flavor precursors occurring in Allium vegetables, S-propyl-L-cysteine and its sulfoxide, were heated in closed model systems at different temperatures (from 80 to 200 degrees C) in the presence of variable amounts of water (0-98%) for 1-60 min. It seems to be indisputable that thermally generated breakdown products of both S-propyl-L-cysteine and particularly S-propyl-L-cysteine sulfoxide can significantly participate in the aroma formation of culinary processed Alliumvegetables. Dipropyl disulfide, dipropyl trisulfide, propylthiol, and dipropyl thiosulfonate were identified as the predominant volatile compounds generated by thermal degradation of S-propylcysteine sulfoxide. Dipropyl disulfide and 2-(propylthio)ethylamine were the major breakdown products formed from S-propylcysteine. Substantial amounts of various alkyl- and alkylthio-substituted pyridines were also generated from both S-propylcysteine and its sulfoxide.

Caffeine as main interfering compound in radioimmunoassay of aflatoxin B1 in coffee samples.

The content of caffeine in coffee extracts prepared for radioimmunoassay of aflatoxin B1 was determined by gas chromatography. The extracts from coffee beans and decaffeinated coffee contained 1.76-4.60 and 0.71-0.85 g caffeine/kg, respectively. These concentrations of caffeine caused false results in radioimmunoassay of aflatoxin B1 in the range 1.0-2.8 micrograms/kg for coffee beans and 0.3-0.4 micrograms/kg for decaffeinated coffee.

Mutagenicity of glycerol chlorohydrines and of their esters with higher fatty acids present in protein hydrolysates.

3-chloro-1,2-propanediol and 1,3-dichloro-2-propanol caused base substitutions in Salmonella typhimurium TA1535 both with and without metabolic activation. Metabolic activation seemed to act mainly by decreasing the toxicity of these compounds. A difference in the growth of the wild-type and repair-deficient strains of Escherichia coli was observed only for 1,3-dichloro-2-propanol with S9 mix. Esters of both chlorohydrines with fatty acids has smaller mutagenic effects than unesterified compounds.