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James T Harvey - One of the best experts on this subject based on the ideXlab platform.
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total mercury body burden in pacific Harbor Seal phoca vitulina richardii pups from central california
Marine Pollution Bulletin, 2008Co-Authors: Tiffini J Brookens, Todd M Ohara, Gerald R Bratton, James T HarveyAbstract:Abstract To determine body and tissue compartment-specific burdens (mg) of total mercury (THg), tissues were weighed and analyzed for THg concentration (μg/g fw) in Pacific Harbor Seal ( Phoca vitulina richardii ) pups from central California in 2006. THg concentrations were related as follows: hair ≫ liver = kidney = pelt > muscle > other = heart > brain > blubber > bone. THg burden, however, was related as: pelt = muscle > liver = other > kidney = blubber > brain = heart > bone. THg concentration and burden in muscle were strongly associated with δ 15 N. δ 13 C and δ 15 N values were significantly greater in muscle than liver, and δ 13 C was significantly lesser the longer animals were in rehabilitation. Because THg concentration and burden in muscle correlated most significantly with other tissue compartments, we recommend that muscle from the specific sites we sampled be used instead of liver or hair for biomonitoring THg in Harbor Seals. Assessment of proportional THg burdens within each tissue compartment for Harbor Seals pups included use of a conceptual model, allowing for more complete visual characterization of THg body burden.
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total mercury body burden in pacific Harbor Seal phoca vitulina richardii pups from central california
Marine Pollution Bulletin, 2008Co-Authors: Tiffini J Brookens, Todd M Ohara, Gerald R Bratton, Robert J Taylor, James T HarveyAbstract:To determine body and tissue compartment-specific burdens (mg) of total mercury (THg), tissues were weighed and analyzed for THg concentration (microg/g fw) in Pacific Harbor Seal (Phoca vitulina richardii) pups from central California in 2006. THg concentrations were related as follows: hair >> liver = kidney = pelt > muscle > other = heart > brain > blubber > bone. THg burden, however, was related as: pelt = muscle > liver = other > kidney = blubber > brain = heart > bone. THg concentration and burden in muscle were strongly associated with delta(15)N. delta(13)C and delta(15)N values were significantly greater in muscle than liver, and delta(13)C was significantly lesser the longer animals were in rehabilitation. Because THg concentration and burden in muscle correlated most significantly with other tissue compartments, we recommend that muscle from the specific sites we sampled be used instead of liver or hair for biomonitoring THg in Harbor Seals. Assessment of proportional THg burdens within each tissue compartment for Harbor Seals pups included use of a conceptual model, allowing for more complete visual characterization of THg body burden.
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trace element concentrations in the pacific Harbor Seal phoca vitulina richardii in central and northern california
Science of The Total Environment, 2007Co-Authors: Tiffini J Brookens, James T Harvey, Todd M OharaAbstract:To determine concentrations of trace elements (THg, MeHg, Se, and Pb) in tissues of the Pacific Harbor Seal (Phoca vitulina richardii), live (n = 186) and dead Seals (n = 53) were sampled throughout central and northern California from March 2003 to January 2005. There were significant differences in THg concentrations in blood and hair based on age (p < 0.001). Adult male Harbor Seals had greater THg concentrations in their hair than adult female Harbor Seals (p < 0.003). THg concentrations in liver increased linearly with age and δ15N (p < 0.001); whereas, MeHg concentrations in liver increased exponentially until approximately 5 years of age with an asymptote at 1.3 μg/g wet weight. MeHg expressed as a percentage of THg (%MeHg) was best described by a decay function (r2 = 0.796, p < 0.001), decreasing to a minimum at 4 years of age. Hepatic Se increased with age and was in equimolar ratios with THg in adults; whereas, molar ratio of Se:THg in pups deviated from a 1:1 ratio. Significant differences among study locations in THg concentrations in blood and hair were not detected. Assessing the possible effect of sampling location on Hg concentrations, however, was confounded and limited by lack of equal sample sizes for basic age and sex cohorts, a common dilemma in pinniped research.
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contaminant loads and hematological correlates in the Harbor Seal phoca vitulina of san francisco bay california
Journal of Toxicology and Environmental Health, 2005Co-Authors: Jennifer C C Neale, James T Harvey, Frances M D Gulland, Kara R Schmelzer, Elizabeth A Berg, S G Allen, Denise J Greig, Emma K Grigg, Ronald S TjeerdemaAbstract:An expanding body of research indicates that exposure to contaminants may impact marine mammal health, thus possibly contributing to population declines. The Harbor Seal population of the San Francisco Bay (SFB), California, has suffered habitat loss and degradation, including decades of environmental contamination. To explore the possibility of contaminant-induced health alterations in this population, blood levels of polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethylene (DDE), and polybrominated diphenyl ethers (PBDEs) were quantified in free-ranging Seals; relationships between contaminant exposure and several key hematological parameters were examined; and PCB levels in the present study were compared with levels determined in SFB Seals a decade earlier. PCB residues in Harbor Seal blood decreased during the past decade, but remained at levels great enough that adverse reproductive and immunological effects might be expected. Main results included a positive association between leukocyte ...
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hematology and serum chemistry comparisons between free ranging and rehabilitated Harbor Seal phoca vitulina richardsi pups
Journal of Wildlife Diseases, 2003Co-Authors: James T Harvey, Michelle E Lander, Frances M D GullandAbstract:The objectives of this study were to compare the hematology and serum chemistry values between free-ranging and stranded Harbor Seal (Phoca vitulina richardsi) pups and to ascertain how blood values of stranded pups changed during the rehabilitation process. Coincident with these comparisons, reference values were obtained for free-ranging pups. Stranded Harbor Seal pups (n=28) recovered from areas between Pebble Beach and Moss Landing, California (USA) were admitted to The Marine Mammal Center, Sausalito, from March to May 1995, 1996, and 1998. Blood samples were collected from Harbor Seal pups before and after rehabilitation. As a control group, wild Harbor Seal pups were captured at Pebble Beach and Elkhorn Slough (n=42) during the 1995, 1996, and 1998 pupping seasons. Mean eosinophil and calcium values of wild pups were significantly greater than those of newly admitted pups, whereas mean bands, aspartate aminotransferase, alanine aminotransferase, total bilirubin, and chloride values were significant...
Todd M Ohara - One of the best experts on this subject based on the ideXlab platform.
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blood and hair mercury concentrations in the pacific Harbor Seal phoca vitulina richardii pup associations with neurodevelopmental outcomes
Ecohealth, 2015Co-Authors: Samala Van Hoomissen, Denise J Greig, Frances M D Gulland, Margaret J Castellini, Todd M OharaAbstract:Monomethylmercury (MeHg+) is an environmental pollutant, which at sufficiently high exposures, has induced neurotoxicosis in several animal species, including humans. Adverse neurological effects due to gestational exposure are of particular concern as MeHg+ readily crosses the blood–brain and placental barriers. The degree to which environmental concentrations in marine prey affect free-living piscivorous wildlife, however, remains largely undetermined. We examined associations of gestational exposures to mercury on neurodevelopment and survival using hair and blood concentrations of total mercury ([THg]) in a stranded population of Pacific Harbor Seal pups from central California. A positive association was determined for the presence of abnormal neurological symptoms and increasing [THg] in blood (P = 0.04), but not hair. Neither hair nor blood [THg] was significantly associated with survival, or the neurodevelopmental milestone ‘free-feeding’, which was measured from the onset of hand-assisted feeding to the time at which pups were able to consume fish independently. Both hair and blood [THg] exceeded threshold values considered potentially toxic to humans and other mammalian wildlife species. The higher [THg] in blood associated with abnormal neurological symptoms may indicate an adverse effect of this pollutant on neurodevelopment in Harbor Seal pups. These data have broader implications with respect to human health and public policy as Harbor Seals and humans consume similar fish species, and it is possible that safeguard levels established for marine mammals could also extend to human populations that regularly consume fish.
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total mercury body burden in pacific Harbor Seal phoca vitulina richardii pups from central california
Marine Pollution Bulletin, 2008Co-Authors: Tiffini J Brookens, Todd M Ohara, Gerald R Bratton, James T HarveyAbstract:Abstract To determine body and tissue compartment-specific burdens (mg) of total mercury (THg), tissues were weighed and analyzed for THg concentration (μg/g fw) in Pacific Harbor Seal ( Phoca vitulina richardii ) pups from central California in 2006. THg concentrations were related as follows: hair ≫ liver = kidney = pelt > muscle > other = heart > brain > blubber > bone. THg burden, however, was related as: pelt = muscle > liver = other > kidney = blubber > brain = heart > bone. THg concentration and burden in muscle were strongly associated with δ 15 N. δ 13 C and δ 15 N values were significantly greater in muscle than liver, and δ 13 C was significantly lesser the longer animals were in rehabilitation. Because THg concentration and burden in muscle correlated most significantly with other tissue compartments, we recommend that muscle from the specific sites we sampled be used instead of liver or hair for biomonitoring THg in Harbor Seals. Assessment of proportional THg burdens within each tissue compartment for Harbor Seals pups included use of a conceptual model, allowing for more complete visual characterization of THg body burden.
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total mercury body burden in pacific Harbor Seal phoca vitulina richardii pups from central california
Marine Pollution Bulletin, 2008Co-Authors: Tiffini J Brookens, Todd M Ohara, Gerald R Bratton, Robert J Taylor, James T HarveyAbstract:To determine body and tissue compartment-specific burdens (mg) of total mercury (THg), tissues were weighed and analyzed for THg concentration (microg/g fw) in Pacific Harbor Seal (Phoca vitulina richardii) pups from central California in 2006. THg concentrations were related as follows: hair >> liver = kidney = pelt > muscle > other = heart > brain > blubber > bone. THg burden, however, was related as: pelt = muscle > liver = other > kidney = blubber > brain = heart > bone. THg concentration and burden in muscle were strongly associated with delta(15)N. delta(13)C and delta(15)N values were significantly greater in muscle than liver, and delta(13)C was significantly lesser the longer animals were in rehabilitation. Because THg concentration and burden in muscle correlated most significantly with other tissue compartments, we recommend that muscle from the specific sites we sampled be used instead of liver or hair for biomonitoring THg in Harbor Seals. Assessment of proportional THg burdens within each tissue compartment for Harbor Seals pups included use of a conceptual model, allowing for more complete visual characterization of THg body burden.
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trace element concentrations in the pacific Harbor Seal phoca vitulina richardii in central and northern california
Science of The Total Environment, 2007Co-Authors: Tiffini J Brookens, James T Harvey, Todd M OharaAbstract:To determine concentrations of trace elements (THg, MeHg, Se, and Pb) in tissues of the Pacific Harbor Seal (Phoca vitulina richardii), live (n = 186) and dead Seals (n = 53) were sampled throughout central and northern California from March 2003 to January 2005. There were significant differences in THg concentrations in blood and hair based on age (p < 0.001). Adult male Harbor Seals had greater THg concentrations in their hair than adult female Harbor Seals (p < 0.003). THg concentrations in liver increased linearly with age and δ15N (p < 0.001); whereas, MeHg concentrations in liver increased exponentially until approximately 5 years of age with an asymptote at 1.3 μg/g wet weight. MeHg expressed as a percentage of THg (%MeHg) was best described by a decay function (r2 = 0.796, p < 0.001), decreasing to a minimum at 4 years of age. Hepatic Se increased with age and was in equimolar ratios with THg in adults; whereas, molar ratio of Se:THg in pups deviated from a 1:1 ratio. Significant differences among study locations in THg concentrations in blood and hair were not detected. Assessing the possible effect of sampling location on Hg concentrations, however, was confounded and limited by lack of equal sample sizes for basic age and sex cohorts, a common dilemma in pinniped research.
Tiffini J Brookens - One of the best experts on this subject based on the ideXlab platform.
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total mercury body burden in pacific Harbor Seal phoca vitulina richardii pups from central california
Marine Pollution Bulletin, 2008Co-Authors: Tiffini J Brookens, Todd M Ohara, Gerald R Bratton, James T HarveyAbstract:Abstract To determine body and tissue compartment-specific burdens (mg) of total mercury (THg), tissues were weighed and analyzed for THg concentration (μg/g fw) in Pacific Harbor Seal ( Phoca vitulina richardii ) pups from central California in 2006. THg concentrations were related as follows: hair ≫ liver = kidney = pelt > muscle > other = heart > brain > blubber > bone. THg burden, however, was related as: pelt = muscle > liver = other > kidney = blubber > brain = heart > bone. THg concentration and burden in muscle were strongly associated with δ 15 N. δ 13 C and δ 15 N values were significantly greater in muscle than liver, and δ 13 C was significantly lesser the longer animals were in rehabilitation. Because THg concentration and burden in muscle correlated most significantly with other tissue compartments, we recommend that muscle from the specific sites we sampled be used instead of liver or hair for biomonitoring THg in Harbor Seals. Assessment of proportional THg burdens within each tissue compartment for Harbor Seals pups included use of a conceptual model, allowing for more complete visual characterization of THg body burden.
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total mercury body burden in pacific Harbor Seal phoca vitulina richardii pups from central california
Marine Pollution Bulletin, 2008Co-Authors: Tiffini J Brookens, Todd M Ohara, Gerald R Bratton, Robert J Taylor, James T HarveyAbstract:To determine body and tissue compartment-specific burdens (mg) of total mercury (THg), tissues were weighed and analyzed for THg concentration (microg/g fw) in Pacific Harbor Seal (Phoca vitulina richardii) pups from central California in 2006. THg concentrations were related as follows: hair >> liver = kidney = pelt > muscle > other = heart > brain > blubber > bone. THg burden, however, was related as: pelt = muscle > liver = other > kidney = blubber > brain = heart > bone. THg concentration and burden in muscle were strongly associated with delta(15)N. delta(13)C and delta(15)N values were significantly greater in muscle than liver, and delta(13)C was significantly lesser the longer animals were in rehabilitation. Because THg concentration and burden in muscle correlated most significantly with other tissue compartments, we recommend that muscle from the specific sites we sampled be used instead of liver or hair for biomonitoring THg in Harbor Seals. Assessment of proportional THg burdens within each tissue compartment for Harbor Seals pups included use of a conceptual model, allowing for more complete visual characterization of THg body burden.
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trace element concentrations in the pacific Harbor Seal phoca vitulina richardii in central and northern california
Science of The Total Environment, 2007Co-Authors: Tiffini J Brookens, James T Harvey, Todd M OharaAbstract:To determine concentrations of trace elements (THg, MeHg, Se, and Pb) in tissues of the Pacific Harbor Seal (Phoca vitulina richardii), live (n = 186) and dead Seals (n = 53) were sampled throughout central and northern California from March 2003 to January 2005. There were significant differences in THg concentrations in blood and hair based on age (p < 0.001). Adult male Harbor Seals had greater THg concentrations in their hair than adult female Harbor Seals (p < 0.003). THg concentrations in liver increased linearly with age and δ15N (p < 0.001); whereas, MeHg concentrations in liver increased exponentially until approximately 5 years of age with an asymptote at 1.3 μg/g wet weight. MeHg expressed as a percentage of THg (%MeHg) was best described by a decay function (r2 = 0.796, p < 0.001), decreasing to a minimum at 4 years of age. Hepatic Se increased with age and was in equimolar ratios with THg in adults; whereas, molar ratio of Se:THg in pups deviated from a 1:1 ratio. Significant differences among study locations in THg concentrations in blood and hair were not detected. Assessing the possible effect of sampling location on Hg concentrations, however, was confounded and limited by lack of equal sample sizes for basic age and sex cohorts, a common dilemma in pinniped research.
Andrea L Bogomolni - One of the best experts on this subject based on the ideXlab platform.
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in vitro exposure of Harbor Seal immune cells to aroclor 1260 alters phocine distemper virus replication
Archives of Environmental Contamination and Toxicology, 2016Co-Authors: Andrea L Bogomolni, Keith Matassa, Gordon T Waring, Ole Nielsen, Milton Levin, Salvatore Frasca, Sylvain De GuiseAbstract:In the last 30 years, several large-scale marine mammal mortality events have occurred, often in close association with highly polluted regions, leading to suspicions that contaminant-induced immunosuppression contributed to these epizootics. Some of these recent events also identified morbillivirus as a cause of or contributor to death. The role of contaminant exposures regarding morbillivirus mortality is still unclear. The results of this study aimed to address the potential for a mixture of polychlorinated biphenyls (PCBs), specifically Aroclor 1260, to alter Harbor Seal T-lymphocyte proliferation and to assess if exposure resulted in increased likelihood of phocine distemper virus (PDV USA 2006) to infect susceptible Seals in an in vitro system. Exposure of peripheral blood mononuclear cells to Aroclor 1260 did not significantly alter lymphocyte proliferation (1, 5, 10, and 20 ppm). However, using reverse transcription-quantitative polymerase chain reaction (RT-qPCR), lymphocytes exposed to 20 ppm Aroclor 1260 exhibited a significant decrease in PDV replication at day 7 and a significant increase at day 11 compared with unexposed control cells. Similar and significant differences were apparent on exposure to Aroclor 1260 in monocytes and supernatant. The results here indicate that in Harbor Seals, Aroclor 1260 exposure results in a decrease in virus early during infection and an increase during late infection. The consequences of this contaminant-induced infection pattern in a highly susceptible host could result in a greater potential for systemic infection with greater viral load, which could explain the correlative findings seen in wild populations exposed to a range of persistent contaminants that suffer from morbillivirus epizootics.
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saxitoxin increases phocine distemper virus replication upon in vitro infection in Harbor Seal immune cells
Harmful Algae, 2016Co-Authors: Andrea L Bogomolni, Gordon T Waring, Ole Nielsen, Milton Levin, Anna L Bass, Spencer E Fire, Lindsay Jasperse, Sylvain De GuiseAbstract:Abstract Several marine mammal epizootics have been closely linked to infectious diseases, as well as to the biotoxins produced by harmful algal blooms (HABs). In two of three saxitoxin (STX) associated mortality events, dolphin morbillivirus (DMV) or phocine distemper virus (PDV) was isolated in affected individuals. While STX is notorious for its neurotoxicity, immunotoxic effects have also been described. This study investigated the role of STX in altering immune function, specifically T lymphocyte proliferation, in Harbor Seals ( Phoca vitulina concolor ) upon in-vitro exposure. In addition, the study also examined whether exposure to STX could alter the susceptibility of Harbor Seal immune cells to PDV infection upon in-vitro exposure. STX caused an increase in Harbor Seal lymphocyte proliferation at 10 ppb and exposure to STX significantly increased the amount of virus present in lymphocytes. These results suggest that low levels of STX within the range of those reported in northeast U.S. Seals may affect the likelihood of systemic PDV infection upon in-vivo exposure in susceptible Seals. Given the concurrent increase in morbillivirus epizootics and HAB events in the last 25 years, the relationship between low level toxin exposure and host susceptibility to morbillivirus needs to be further explored.
Sylvain De Guise - One of the best experts on this subject based on the ideXlab platform.
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in vitro exposure of Harbor Seal immune cells to aroclor 1260 alters phocine distemper virus replication
Archives of Environmental Contamination and Toxicology, 2016Co-Authors: Andrea L Bogomolni, Keith Matassa, Gordon T Waring, Ole Nielsen, Milton Levin, Salvatore Frasca, Sylvain De GuiseAbstract:In the last 30 years, several large-scale marine mammal mortality events have occurred, often in close association with highly polluted regions, leading to suspicions that contaminant-induced immunosuppression contributed to these epizootics. Some of these recent events also identified morbillivirus as a cause of or contributor to death. The role of contaminant exposures regarding morbillivirus mortality is still unclear. The results of this study aimed to address the potential for a mixture of polychlorinated biphenyls (PCBs), specifically Aroclor 1260, to alter Harbor Seal T-lymphocyte proliferation and to assess if exposure resulted in increased likelihood of phocine distemper virus (PDV USA 2006) to infect susceptible Seals in an in vitro system. Exposure of peripheral blood mononuclear cells to Aroclor 1260 did not significantly alter lymphocyte proliferation (1, 5, 10, and 20 ppm). However, using reverse transcription-quantitative polymerase chain reaction (RT-qPCR), lymphocytes exposed to 20 ppm Aroclor 1260 exhibited a significant decrease in PDV replication at day 7 and a significant increase at day 11 compared with unexposed control cells. Similar and significant differences were apparent on exposure to Aroclor 1260 in monocytes and supernatant. The results here indicate that in Harbor Seals, Aroclor 1260 exposure results in a decrease in virus early during infection and an increase during late infection. The consequences of this contaminant-induced infection pattern in a highly susceptible host could result in a greater potential for systemic infection with greater viral load, which could explain the correlative findings seen in wild populations exposed to a range of persistent contaminants that suffer from morbillivirus epizootics.
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saxitoxin increases phocine distemper virus replication upon in vitro infection in Harbor Seal immune cells
Harmful Algae, 2016Co-Authors: Andrea L Bogomolni, Gordon T Waring, Ole Nielsen, Milton Levin, Anna L Bass, Spencer E Fire, Lindsay Jasperse, Sylvain De GuiseAbstract:Abstract Several marine mammal epizootics have been closely linked to infectious diseases, as well as to the biotoxins produced by harmful algal blooms (HABs). In two of three saxitoxin (STX) associated mortality events, dolphin morbillivirus (DMV) or phocine distemper virus (PDV) was isolated in affected individuals. While STX is notorious for its neurotoxicity, immunotoxic effects have also been described. This study investigated the role of STX in altering immune function, specifically T lymphocyte proliferation, in Harbor Seals ( Phoca vitulina concolor ) upon in-vitro exposure. In addition, the study also examined whether exposure to STX could alter the susceptibility of Harbor Seal immune cells to PDV infection upon in-vitro exposure. STX caused an increase in Harbor Seal lymphocyte proliferation at 10 ppb and exposure to STX significantly increased the amount of virus present in lymphocytes. These results suggest that low levels of STX within the range of those reported in northeast U.S. Seals may affect the likelihood of systemic PDV infection upon in-vivo exposure in susceptible Seals. Given the concurrent increase in morbillivirus epizootics and HAB events in the last 25 years, the relationship between low level toxin exposure and host susceptibility to morbillivirus needs to be further explored.
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association between lymphocyte proliferation and polychlorinated biphenyls in free ranging Harbor Seal phoca vitulina pups from british columbia canada
Environmental Toxicology and Chemistry, 2005Co-Authors: Milton Levin, Sylvain De Guise, Peter S RossAbstract:Recent pinniped die-offs have led to the speculation that persistent organic pollutants (POPs) are immunomodulatory, making individuals more susceptible to viral infections. Eighteen healthy Harbor Seal (Phoca vitulina) pups (aged 3-4 weeks) were live-captured from southern British Columbia, Canada, and maintained temporarily in captivity for an immunotoxicological assessment. The relationships between mitogen-induced peripheral blood lymphocyte proliferation and blubber concentrations of three major immunotoxic POP classes (the polychlorinated biphenyls [PCBs], polychlorinated dibenzo-p-dioxins [PCDDs], and the polychlorinated dibenzofurans [PCDFs]) were evaluated. A significant body weight-independent positive correlation was observed between both T-cell mitogen (phytohemagglutinin [PHA])- and B-cell mitogen (lipopolysaccharide [LPS])-induced lymphocyte proliferation and the blubber concentrations of total PCB. Best subset regression analysis revealed that total PCBs, and not total PCDD or total PCDF, explained 24 and 29% of the changes in both T-cell mitogen-and B-cell mitogen-induced lymphocyte proliferation, respectively. Further regression analysis performed on the PCB classes measured in this study showed that di-ortho PCBs accounted for 25 and 30% of the changes in both T-cell and B-cell lymphocyte proliferation, respectively. Results suggest that POPs, and PCBs in particular, are associated with changes in lymphocyte proliferation, something that could result in increased susceptibility to infections in Harbor Seal pups. Further research is needed to evaluate the relative roles of natural and contaminant-related influences on the immune system of marine mammals.
