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Roy Siddall - One of the best experts on this subject based on the ideXlab platform.
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pomphorhynchus laevis palaeacanthocephala in the intestine of chub leuciscus cephalus as an indicator of metal pollution
International Journal for Parasitology, 2003Co-Authors: Bernd Sures, Roy SiddallAbstract:Chub experimentally infected with the acanthocephalan parasite Pomphorhynchuslaevis were exposed to 0.01 mg l−1 Pb2+ over 5 weeks. Lead was rapidly accumulated in the intestinal worms reaching a steady-state Concentration after 4 weeks. This Concentration was significantly greater than in the host muscle, liver and intestine and more than 9,000 times higher than the Exposure Concentration. Lead accumulation in P. laevis increased at a higher Exposure Concentration but was not correlated with either parasite intensity or with pooled or individual worm weight. The highest lead Concentrations were recorded in those specimen of P. laevis that were attached in the posterior intestine. Interestingly, parasitised chub accumulated less lead in their own tissues than uninfected conspecifics. A mechanism of lead uptake by P. laevis and the application of acanthocephalans as accumulation indicators of metal pollution is discussed.
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comparison between lead accumulation of pomphorhynchus laevis palaeacanthocephala in the intestine of chub leuciscus cephalus and in the body cavity of goldfish carassius auratus auratus
International Journal for Parasitology, 2001Co-Authors: Bernd Sures, Roy SiddallAbstract:This experimental study assessed the role of the microhabitat in the uptake of metals by adult acanthocephalans. We examined the accumulation of lead by adult Pomphorhynchus laevis in the intestine of chub (Leuciscus cephalus) and compared it with that in goldfish, Carassius auratus auratus, in which the parasites penetrate the intestinal wall and enter the body cavity. Chub and goldfish experimentally infected with adult Pomphorhynchus laevis were exposed to 0.01 mg l−1 Pb2+ over 3 weeks. Lead was rapidly accumulated in the intestinal acanthocephalans reaching a mean Concentration of 7.3 μg g−1. This Concentration was significantly greater than in the host muscle, liver and intestine and more than 730 times higher than the Exposure Concentration. Intraperitoneal P. laevis in goldfish exposed to lead did not accumulate the metal. Thus, it was conclusively shown that metal accumulation in acanthocephalans is associated with the intestinal location and does not occur in the body cavity.
Gretchen K Bielmyerfraser - One of the best experts on this subject based on the ideXlab platform.
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dietary metal toxicity to the marine sea hare aplysia californica
Comparative Biochemistry and Physiology C-toxicology & Pharmacology, 2015Co-Authors: Tayler A Jarvis, Thomas R Capo, Gretchen K BielmyerfraserAbstract:Metal pollution from anthropogenic inputs is a concern in many marine environments. Metals accumulate in tissue and in excess cause toxicity in marine organisms. This study investigated the accumulation and effects of dietary metals in a macroinvertebrate. The green seaweed, Ulva lactuca and the red seaweed, Agardhiella subulata were each concurrently exposed to two Concentrations (100 or 1000 μg/L) of five metals (Cu, Ni, Pb, Cd, and Zn). Additionally, U. lactuca was exposed to 10 μg/L of the metal mixture as well as 10 or 100 μg/L of each metal individually for 48 h. The seaweeds were then used as food for the sea hare, Aplysia californica for two to three weeks depending on the Exposure Concentration. Body mass of A. californica was measured weekly, and at the end of the Exposure duration, metal Concentrations were quantified in dissected organs (mouth, esophagus, crop, gizzard, ovotestis, heart, hepatopancreas, gill, and the carcass). Metal distribution and accumulation in the organs of A. californica varied with the metal. A. californica fed the metal-exposed diets had significantly reduced body weight by the end of the Exposure periods, as compared to controls; however, differences were observed in the extent of growth reductions, dependent on Exposure Concentration, duration, and Exposure regime (metal mixture versus individual metal-exposed diet). Metal mixture diets decreased A. californica growth more so than comparable individual metal diets, despite more metal accumulating in the individual metal diets. Additionally, Zn- and Cu-contaminated algal diets decreased control-normalized growth of A. californica significantly more than comparable Cd-, Pb-, or Ni-contaminated diets. The seaweed diets in this study contained environmentally relevant tissue metal burdens. Therefore, these results have implications for metals in marine systems.
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dietary metal toxicity to the marine sea hare aplysia californica toxicology pharmacology
Comparative Biochemistry and Physiology, 2015Co-Authors: Tayler A Jarvis, Thomas R Capo, Gretchen K BielmyerfraserAbstract:Metal pollution from anthropogenic inputs is a concern in many marine environments. Metals accumulate in tissue and in excess cause toxicity in marine organisms. This study investigated the accumulation and effects of dietary metals in a macroinvertebrate. The green seaweed, Ulva lactuca and the red seaweed, Agardhiella subulata were each concurrently exposed to two Concentrations (100 or 1000μg/L) of five metals (Cu, Ni, Pb, Cd, and Zn). Additionally, U. lactuca was exposed to 10μg/L of the metal mixture as well as 10 or 100μg/L of each metal individually for 48h. The seaweeds were then used as food for the sea hare, Aplysia californica for two to three weeks depending on the Exposure Concentration. Body mass of A. californica was measured weekly, and at the end of the Exposure duration, metal Concentrations were quantified in dissected organs (mouth, esophagus, crop, gizzard, ovotestis, heart, hepatopancreas, gill, and the carcass). Metal distribution and accumulation in the organs of A. californica varied with the metal. A. californica fed the metal-exposed diets had significantly reduced body weight by the end of the Exposure periods, as compared to controls; however, differences were observed in the extent of growth reductions, dependent on Exposure Concentration, duration, and Exposure regime (metal mixture versus individual metal-exposed diet). Metal mixture diets decreased A. californica growth more so than comparable individual metal diets, despite more metal accumulating in the individual metal diets. Additionally, Zn- and Cu-contaminated algal diets decreased control-normalized growth of A. californica significantly more than comparable Cd-, Pb-, or Ni-contaminated diets. The seaweed diets in this study contained environmentally relevant tissue metal burdens. Therefore, these results have implications for metals in marine systems.
Bernd Sures - One of the best experts on this subject based on the ideXlab platform.
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pomphorhynchus laevis palaeacanthocephala in the intestine of chub leuciscus cephalus as an indicator of metal pollution
International Journal for Parasitology, 2003Co-Authors: Bernd Sures, Roy SiddallAbstract:Chub experimentally infected with the acanthocephalan parasite Pomphorhynchuslaevis were exposed to 0.01 mg l−1 Pb2+ over 5 weeks. Lead was rapidly accumulated in the intestinal worms reaching a steady-state Concentration after 4 weeks. This Concentration was significantly greater than in the host muscle, liver and intestine and more than 9,000 times higher than the Exposure Concentration. Lead accumulation in P. laevis increased at a higher Exposure Concentration but was not correlated with either parasite intensity or with pooled or individual worm weight. The highest lead Concentrations were recorded in those specimen of P. laevis that were attached in the posterior intestine. Interestingly, parasitised chub accumulated less lead in their own tissues than uninfected conspecifics. A mechanism of lead uptake by P. laevis and the application of acanthocephalans as accumulation indicators of metal pollution is discussed.
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comparison between lead accumulation of pomphorhynchus laevis palaeacanthocephala in the intestine of chub leuciscus cephalus and in the body cavity of goldfish carassius auratus auratus
International Journal for Parasitology, 2001Co-Authors: Bernd Sures, Roy SiddallAbstract:This experimental study assessed the role of the microhabitat in the uptake of metals by adult acanthocephalans. We examined the accumulation of lead by adult Pomphorhynchus laevis in the intestine of chub (Leuciscus cephalus) and compared it with that in goldfish, Carassius auratus auratus, in which the parasites penetrate the intestinal wall and enter the body cavity. Chub and goldfish experimentally infected with adult Pomphorhynchus laevis were exposed to 0.01 mg l−1 Pb2+ over 3 weeks. Lead was rapidly accumulated in the intestinal acanthocephalans reaching a mean Concentration of 7.3 μg g−1. This Concentration was significantly greater than in the host muscle, liver and intestine and more than 730 times higher than the Exposure Concentration. Intraperitoneal P. laevis in goldfish exposed to lead did not accumulate the metal. Thus, it was conclusively shown that metal accumulation in acanthocephalans is associated with the intestinal location and does not occur in the body cavity.
Tayler A Jarvis - One of the best experts on this subject based on the ideXlab platform.
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dietary metal toxicity to the marine sea hare aplysia californica
Comparative Biochemistry and Physiology C-toxicology & Pharmacology, 2015Co-Authors: Tayler A Jarvis, Thomas R Capo, Gretchen K BielmyerfraserAbstract:Metal pollution from anthropogenic inputs is a concern in many marine environments. Metals accumulate in tissue and in excess cause toxicity in marine organisms. This study investigated the accumulation and effects of dietary metals in a macroinvertebrate. The green seaweed, Ulva lactuca and the red seaweed, Agardhiella subulata were each concurrently exposed to two Concentrations (100 or 1000 μg/L) of five metals (Cu, Ni, Pb, Cd, and Zn). Additionally, U. lactuca was exposed to 10 μg/L of the metal mixture as well as 10 or 100 μg/L of each metal individually for 48 h. The seaweeds were then used as food for the sea hare, Aplysia californica for two to three weeks depending on the Exposure Concentration. Body mass of A. californica was measured weekly, and at the end of the Exposure duration, metal Concentrations were quantified in dissected organs (mouth, esophagus, crop, gizzard, ovotestis, heart, hepatopancreas, gill, and the carcass). Metal distribution and accumulation in the organs of A. californica varied with the metal. A. californica fed the metal-exposed diets had significantly reduced body weight by the end of the Exposure periods, as compared to controls; however, differences were observed in the extent of growth reductions, dependent on Exposure Concentration, duration, and Exposure regime (metal mixture versus individual metal-exposed diet). Metal mixture diets decreased A. californica growth more so than comparable individual metal diets, despite more metal accumulating in the individual metal diets. Additionally, Zn- and Cu-contaminated algal diets decreased control-normalized growth of A. californica significantly more than comparable Cd-, Pb-, or Ni-contaminated diets. The seaweed diets in this study contained environmentally relevant tissue metal burdens. Therefore, these results have implications for metals in marine systems.
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dietary metal toxicity to the marine sea hare aplysia californica toxicology pharmacology
Comparative Biochemistry and Physiology, 2015Co-Authors: Tayler A Jarvis, Thomas R Capo, Gretchen K BielmyerfraserAbstract:Metal pollution from anthropogenic inputs is a concern in many marine environments. Metals accumulate in tissue and in excess cause toxicity in marine organisms. This study investigated the accumulation and effects of dietary metals in a macroinvertebrate. The green seaweed, Ulva lactuca and the red seaweed, Agardhiella subulata were each concurrently exposed to two Concentrations (100 or 1000μg/L) of five metals (Cu, Ni, Pb, Cd, and Zn). Additionally, U. lactuca was exposed to 10μg/L of the metal mixture as well as 10 or 100μg/L of each metal individually for 48h. The seaweeds were then used as food for the sea hare, Aplysia californica for two to three weeks depending on the Exposure Concentration. Body mass of A. californica was measured weekly, and at the end of the Exposure duration, metal Concentrations were quantified in dissected organs (mouth, esophagus, crop, gizzard, ovotestis, heart, hepatopancreas, gill, and the carcass). Metal distribution and accumulation in the organs of A. californica varied with the metal. A. californica fed the metal-exposed diets had significantly reduced body weight by the end of the Exposure periods, as compared to controls; however, differences were observed in the extent of growth reductions, dependent on Exposure Concentration, duration, and Exposure regime (metal mixture versus individual metal-exposed diet). Metal mixture diets decreased A. californica growth more so than comparable individual metal diets, despite more metal accumulating in the individual metal diets. Additionally, Zn- and Cu-contaminated algal diets decreased control-normalized growth of A. californica significantly more than comparable Cd-, Pb-, or Ni-contaminated diets. The seaweed diets in this study contained environmentally relevant tissue metal burdens. Therefore, these results have implications for metals in marine systems.
B. Schmit - One of the best experts on this subject based on the ideXlab platform.
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Human safety and pharmacokinetics of the CFC alternative propellants HFC 134a (1,1,1,2-tetrafluoroethane) and HFC 227 (1,1,1,2,3,3, 3-heptafluoropropane) following whole-body Exposure.
Regulatory Toxicology and Pharmacology, 2000Co-Authors: H.h. Emmen, E.m.g. Hoogendijk, W.a.a. Klöpping-ketelaars, Hans Muijser, E. Duistermaat, J. C. Ravensberg, D. J. Alexander, D. Borkhataria, George M. Rusch, B. SchmitAbstract:HFC 134a (1,1,1,2-tetrafluoroethane) and HFC 227 (1,1,1,2,3,3,3-heptafluoropropane) are used to replace chlorofluorocarbons (CFCs) in refrigerant and aerosol applications, including medical use in metered-dose inhalers. Production and consumption of CFCs are being phased out under the Montreal Protocol on Substances that Deplete the Ozone Layer. The safety and pharmacokinetics of HFC 134a and HFC 227 were assessed in two separate double-blind studies. Each HFC (hydrofluorocarbon) was administered via whole-body Exposure as a vapor to eight (four male and four female) healthy volunteers. Volunteers were exposed, once weekly for 1 h, first to air and then to ascending Concentrations of HFC (1000, 2000, 4000, and 8000 parts per million (ppm)), interspersed with a second air Exposure and two CFC 12 (dichlorodifluoromethane) Exposures (1000 and 4000 ppm). Comparison of either HFC 134a or HFC 227 to CFC 12 or air gave no clinically significant results for any of the measured laboratory parameters. There were no notable adverse events, there was no evidence of effects on the central nervous system, and there were no symptoms of upper respiratory tract irritation. HFC 134a, HFC 227, and CFC 12 blood Concentrations increased rapidly and in an Exposure-Concentration-dependent mariner, although not strictly proportionally, and approached steady state. Maximum blood Concentrations (C(max)) tended to be higher in males than females; in the HFC 227 study, these were statistically significantly (P < 0.05) higher in males for each HFC 227 and CFC 12 Exposure level. In the HFC 134a study, the gender difference in C(max) was only statistically significant (P < 0.05) for CFC 12 at 4000 ppm and HFC 134a at 8000 ppm. Following the end of Exposure, blood Concentrations declined rapidly, predominantly biphasically and independent of Exposure Concentration. For the HFC 134a study, the t( 1/2 )α (α elimination half-life) was short for both CFC 12 and HFC 134a (
