The Experts below are selected from a list of 3543 Experts worldwide ranked by ideXlab platform
Judit E G Smits - One of the best experts on this subject based on the ideXlab platform.
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reproductive abnormalities teratogenicity and developmental problems in american kestrels falco sparverius exposed to polychlorinated biphenyls
Journal of Toxicology and Environmental Health, 2003Co-Authors: Kim J Fernie, Gary R Bortolotti, Judit E G SmitsAbstract:This study found abnormalities in multiple reproductive stages in captive American kestrels (Falco sparverius) when exposed to polychlorinated biphenyls (PCBs) through dietary and in ovo exposure. American kestrels laid eggs with environmentally relevant total PCB levels (34.1 μg/g whole egg wet weight) when consuming PCB-spiked (Aroclor 1248:1254:1260) food (5–7 μg/g body weight per day) for 100 d only in 1998. In 1999, the same adults laid eggs with estimated total PCBs of 23 μg/g. Effects of maternal (only female exposed) and paternal (only male expose d) in ovo PCB exposure were investigated. Maternal F1 eggs contained predicted total PCB concentrations of 0.34 μg/g. Specific abnormalities occurred more frequently during dietary F0 exposure, particularly aggressive courtship interactions, clutch abandonment, occurrences of cracked eggs, and developmental effects. Multiple developmental effects were more pronounced during than after dietary PCB exposure of adults, and although these effects were limite...
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thyroid hormone suppression and cell mediated immunomodulation in american kestrels falco sparverius exposed to pcbs
Archives of Environmental Contamination and Toxicology, 2002Co-Authors: Judit E G Smits, Kimberly J Fernie, Gary R Bortolotti, Tracy A MarchantAbstract:Exposure to environmental contaminants can induce physiological changes in animals through various mechanisms. One manifestation of subclinical toxicity from polychlorinated biphenyl (PCB) exposure is the disruption of normal immune function described in numerous species, including American kestrels (Falco sparverius). In 1998, 152 mature male and female kestrels were fed either a mixture of Aroclor 1248: 1254:1260 (approximately 7 mg/kg kestrel/day) through their food items, or control diets. Offspring produced by 50 breeding pairs (thus, half received in ovo PCB exposure only) were also studied. Total and differential white blood cell counts, the phytohemagglutinin (PHA) skin response, as well as thyroid hormone levels were tested in vivo in nonbreeding adults (1998 only) and nestlings (1998 and 1999). In 1999, nestlings came from three parental groups; adults exposed in 1998, birds produced by PCB-exposed parents, and unexposed birds. In 1998, directly exposed males but not females had increased total white blood cell counts driven by lymphocytosis, plus a decreased heterophil-to-lymphocyte ratio relative to controls. PCB-exposed birds had a significantly greater response to PHA than did controls, with sex as a significant factor and plasma triiodothyonine (T3) as a significant covariate. Levels of T3 were significantly depressed in PCB-exposed birds of both sexes. The 1999 nestlings (F1 generation with respect to PCB exposure) did not show any effect of parental treatment group on the PHA skin response, yet T3 remained as a significant covariate. Immunological effects are discussed in light of the antibody-mediated immunotoxicity found in the same birds and reported previously.
Tracy A Marchant - One of the best experts on this subject based on the ideXlab platform.
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thyroid hormone suppression and cell mediated immunomodulation in american kestrels falco sparverius exposed to pcbs
Archives of Environmental Contamination and Toxicology, 2002Co-Authors: Judit E G Smits, Kimberly J Fernie, Gary R Bortolotti, Tracy A MarchantAbstract:Exposure to environmental contaminants can induce physiological changes in animals through various mechanisms. One manifestation of subclinical toxicity from polychlorinated biphenyl (PCB) exposure is the disruption of normal immune function described in numerous species, including American kestrels (Falco sparverius). In 1998, 152 mature male and female kestrels were fed either a mixture of Aroclor 1248: 1254:1260 (approximately 7 mg/kg kestrel/day) through their food items, or control diets. Offspring produced by 50 breeding pairs (thus, half received in ovo PCB exposure only) were also studied. Total and differential white blood cell counts, the phytohemagglutinin (PHA) skin response, as well as thyroid hormone levels were tested in vivo in nonbreeding adults (1998 only) and nestlings (1998 and 1999). In 1999, nestlings came from three parental groups; adults exposed in 1998, birds produced by PCB-exposed parents, and unexposed birds. In 1998, directly exposed males but not females had increased total white blood cell counts driven by lymphocytosis, plus a decreased heterophil-to-lymphocyte ratio relative to controls. PCB-exposed birds had a significantly greater response to PHA than did controls, with sex as a significant factor and plasma triiodothyonine (T3) as a significant covariate. Levels of T3 were significantly depressed in PCB-exposed birds of both sexes. The 1999 nestlings (F1 generation with respect to PCB exposure) did not show any effect of parental treatment group on the PHA skin response, yet T3 remained as a significant covariate. Immunological effects are discussed in light of the antibody-mediated immunotoxicity found in the same birds and reported previously.
Maria J. Schymura - One of the best experts on this subject based on the ideXlab platform.
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diabetes in relation to serum levels of polychlorinated biphenyls and chlorinated pesticides in adult native americans
Environmental Health Perspectives, 2007Co-Authors: Neculai Codru, Maria J. Schymura, Serban Negoita, Robert Rej, David O CarpenterAbstract:Diabetes is one of the most prevalent chronic diseases in developed countries, conferring a significant burden in terms of medical complications and health-care costs. Between 1980 and 2004, the number of Americans with diabetes increased from 5.8 million to 14.7 million. In 2004 alone, there were approximately 1.4 million new diagnoses of diabetes in American adults (18–79 years of age) [Centers for Disease Control and Prevention (CDC) 2005]. Incidence and prevalence of diabetes vary by age, ethnicity, and socioeconomic factors and are, in general, higher in Native Americans (CDC 2003a). Known risk factors for diabetes include obesity, genetic susceptibility, hyperinsulinemia (a marker for insulin resistance), sedentary lifestyle (Warram and Krolewski 2005), and cigarette smoking (Rimm et al. 1995; Will et al. 2001). Polychlorinated biphenyls (PCBs) were produced for use in various industries until the late 1970s when their production was banned. By then, large quantities of PCBs had been released into the environment. They are persistent substances both in the environment and in biota, and they bio-accumulate and biomagnify in the food chain. Once in the human body they persist for long periods, accumulating in adipose tissue and in the lipid component of serum. The Mohawk Nation at Akwesasne is a Native American population residing along the St. Lawrence River that separates New York State from Ontario and Quebec (Canada). Mohawks are traditionally a fish-eating community. There are three aluminum foundries just upriver from the reservation, namely the General Motors Central Foundry Division (a National Priority List site) and plants operated by Reynolds Metal and the Aluminum Company of America (ALCOA) (Hwang et al. 1993). PCBs (primarily Aroclor 1248) were used as hydraulic fluids at all three facilities. PCBs that leaked were washed into the St. Lawrence River and its tributaries. Via the air, soil, and water, PCBs contaminated the environment and local flora and fauna, and entered the food chain. Although they are only modestly elevated, PCB levels in Mohawk breast milk (Hwang et al. 1996) and serum (Fitzgerald et al. 2004) have been correlated with rates of consumption of local fish, even though fish consumption has declined in recent years after issuance of advisories. Recent studies have reported an association between exposure to organochlorines and impaired blood-glucose regulation and diabetes. Several epidemiologic studies (Calvert et al. 1999; Pesatori et al. 1998; Vena et al. 1998) have shown that dioxin exposure is associated with elevated rates of diabetes and dysglycemia. U.S. Air Force veterans of Operation Ranch Hand, who applied Agent Orange in Vietnam, were exposed to dioxin. Exposure was associated with an elevated incidence of diabetes and was inversely associated with the length of time to diabetes onset (Henriksen et al. 1997). Cranmer et al. (2000) reported that dioxin exposure resulted in hyperinsulinemia and insulin resistance, and Fierens et al. (2003) reported significant odds ratios (ORs) of 5.1, 13.3, and 7.6 for risk of diabetes in relation to top decile concentrations of dioxins, coplanar PCBs, and 12 PCB markers. Longnecker et al. (2001) reported that pregnant women with diabetes had higher PCB levels than did nondiabetic pregnant women. Radikova et al. (2004) reported that PCB concentrations in a Slovak population were associated with elevated levels of blood glucose. Vasiliu et al. (2006) found a linear association between PCB serum levels and diabetes incidence in a large cohort in Michigan, and Lee et al. (2006) found a strong dose–response relationship between serum concentrations of six persistent organic pollutants [PCB-153, two dioxin congeners, oxychlordane, dichlorodiphenyldichloroethylene (DDE), and trans-nonachlor] and diabetes. Everett et al. (2006) reported an association between serum levels of both PCB-126 (a dioxin-like PCB) and p,p′-DDT (dichlorodiphenyltrichloroethane). DDE, the major metabolite of DDT, has previously been reported to be associated with diabetes (Glynn et al. 2003; Rylander et al. 2005), and hexachlorobenzene (HCB) was also linked to diabetes in cross-sectional studies (Glynn et al. 2003). Lee et al. (2007) have expanded their study to analyze the data from the sum of four dioxin-like PCB congeners and five nondioxin-like congeners, and report that the dioxin-like congeners showed the strongest relationship with diabetes. The present study was designed to investigate whether a relationship exists between diabetes and serum levels of total PCBs, two single PCB congeners, and the chlorinated pesticides DDE, HCB, and mirex in adult Mohawks.
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polychlorinated biphenyl pcb exposure assessment by multivariate statistical analysis of serum congener profiles in an adult native american population
Environmental Research, 2005Co-Authors: Anthony P. Decaprio, Alice Tarbell, Gayle S Morse, Azara L Santiagorivera, Glenn W Johnson, David O Carpenter, Jeffrey Robert Chiarenzelli, Maria J. SchymuraAbstract:Abstract The major determinants of human polychlorinated biphenyl (PCB) body burden include the source and route of exposure and the toxicokinetic processes occurring after uptake. However, the relative importance of each factor for individual subjects cannot currently be determined. The present study characterizes levels and patterns of PCB congeners in a large cohort of adult Akwesasne Mohawks with historical PCB exposure. Total serum PCB ranged from 0.29 to 48.32 ng/g and was higher in adult men than in women (median of 3.81 vs. 2.94 ng/g). The mean serum congener profile for the full cohort was dominated by persistent penta- to hepta-chlorinated biphenyls; several labile congeners were also prominent. In order to provide additional information on individual body burden determinants, multivariate exploratory data analysis techniques were applied to the congener-specific serum PCB data. A self-training receptor model, polytopic vector analysis (PVA), was employed to determine the number, composition, and relative proportions of independent congener patterns that contributed to the overall serum PCB profile for each Mohawk subject. PVA identified five such patterns, each of which was characterized by a unique mix of congeners. One pattern observed in a limited number of Mohawks was similar to those reported for air sampled near contaminated sediment deposits at Akwesasne and for volatilized Aroclor 1248 and is hypothesized to reflect recent inhalation exposure in these subjects. A second pattern was consistent with unaltered Aroclor 1254. A third pattern, resembling Aroclor 1262 but without labile congeners, was correlated with age and is interpreted as representing a lifetime PCB accumulation profile. The final two patterns were dominated by subsets of major persistent congeners and are hypothesized to reflect intermediate bioaccumulation profiles and/or differences in individual toxicokinetics. The results confirm the utility of a multivariate exploratory analysis approach to congener-specific PCB data and provide additional insight into the exposure and individual factors that determine PCB body burden in this population.
Gary R Bortolotti - One of the best experts on this subject based on the ideXlab platform.
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reproductive abnormalities teratogenicity and developmental problems in american kestrels falco sparverius exposed to polychlorinated biphenyls
Journal of Toxicology and Environmental Health, 2003Co-Authors: Kim J Fernie, Gary R Bortolotti, Judit E G SmitsAbstract:This study found abnormalities in multiple reproductive stages in captive American kestrels (Falco sparverius) when exposed to polychlorinated biphenyls (PCBs) through dietary and in ovo exposure. American kestrels laid eggs with environmentally relevant total PCB levels (34.1 μg/g whole egg wet weight) when consuming PCB-spiked (Aroclor 1248:1254:1260) food (5–7 μg/g body weight per day) for 100 d only in 1998. In 1999, the same adults laid eggs with estimated total PCBs of 23 μg/g. Effects of maternal (only female exposed) and paternal (only male expose d) in ovo PCB exposure were investigated. Maternal F1 eggs contained predicted total PCB concentrations of 0.34 μg/g. Specific abnormalities occurred more frequently during dietary F0 exposure, particularly aggressive courtship interactions, clutch abandonment, occurrences of cracked eggs, and developmental effects. Multiple developmental effects were more pronounced during than after dietary PCB exposure of adults, and although these effects were limite...
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thyroid hormone suppression and cell mediated immunomodulation in american kestrels falco sparverius exposed to pcbs
Archives of Environmental Contamination and Toxicology, 2002Co-Authors: Judit E G Smits, Kimberly J Fernie, Gary R Bortolotti, Tracy A MarchantAbstract:Exposure to environmental contaminants can induce physiological changes in animals through various mechanisms. One manifestation of subclinical toxicity from polychlorinated biphenyl (PCB) exposure is the disruption of normal immune function described in numerous species, including American kestrels (Falco sparverius). In 1998, 152 mature male and female kestrels were fed either a mixture of Aroclor 1248: 1254:1260 (approximately 7 mg/kg kestrel/day) through their food items, or control diets. Offspring produced by 50 breeding pairs (thus, half received in ovo PCB exposure only) were also studied. Total and differential white blood cell counts, the phytohemagglutinin (PHA) skin response, as well as thyroid hormone levels were tested in vivo in nonbreeding adults (1998 only) and nestlings (1998 and 1999). In 1999, nestlings came from three parental groups; adults exposed in 1998, birds produced by PCB-exposed parents, and unexposed birds. In 1998, directly exposed males but not females had increased total white blood cell counts driven by lymphocytosis, plus a decreased heterophil-to-lymphocyte ratio relative to controls. PCB-exposed birds had a significantly greater response to PHA than did controls, with sex as a significant factor and plasma triiodothyonine (T3) as a significant covariate. Levels of T3 were significantly depressed in PCB-exposed birds of both sexes. The 1999 nestlings (F1 generation with respect to PCB exposure) did not show any effect of parental treatment group on the PHA skin response, yet T3 remained as a significant covariate. Immunological effects are discussed in light of the antibody-mediated immunotoxicity found in the same birds and reported previously.
David O Carpenter - One of the best experts on this subject based on the ideXlab platform.
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diabetes in relation to serum levels of polychlorinated biphenyls and chlorinated pesticides in adult native americans
Environmental Health Perspectives, 2007Co-Authors: Neculai Codru, Maria J. Schymura, Serban Negoita, Robert Rej, David O CarpenterAbstract:Diabetes is one of the most prevalent chronic diseases in developed countries, conferring a significant burden in terms of medical complications and health-care costs. Between 1980 and 2004, the number of Americans with diabetes increased from 5.8 million to 14.7 million. In 2004 alone, there were approximately 1.4 million new diagnoses of diabetes in American adults (18–79 years of age) [Centers for Disease Control and Prevention (CDC) 2005]. Incidence and prevalence of diabetes vary by age, ethnicity, and socioeconomic factors and are, in general, higher in Native Americans (CDC 2003a). Known risk factors for diabetes include obesity, genetic susceptibility, hyperinsulinemia (a marker for insulin resistance), sedentary lifestyle (Warram and Krolewski 2005), and cigarette smoking (Rimm et al. 1995; Will et al. 2001). Polychlorinated biphenyls (PCBs) were produced for use in various industries until the late 1970s when their production was banned. By then, large quantities of PCBs had been released into the environment. They are persistent substances both in the environment and in biota, and they bio-accumulate and biomagnify in the food chain. Once in the human body they persist for long periods, accumulating in adipose tissue and in the lipid component of serum. The Mohawk Nation at Akwesasne is a Native American population residing along the St. Lawrence River that separates New York State from Ontario and Quebec (Canada). Mohawks are traditionally a fish-eating community. There are three aluminum foundries just upriver from the reservation, namely the General Motors Central Foundry Division (a National Priority List site) and plants operated by Reynolds Metal and the Aluminum Company of America (ALCOA) (Hwang et al. 1993). PCBs (primarily Aroclor 1248) were used as hydraulic fluids at all three facilities. PCBs that leaked were washed into the St. Lawrence River and its tributaries. Via the air, soil, and water, PCBs contaminated the environment and local flora and fauna, and entered the food chain. Although they are only modestly elevated, PCB levels in Mohawk breast milk (Hwang et al. 1996) and serum (Fitzgerald et al. 2004) have been correlated with rates of consumption of local fish, even though fish consumption has declined in recent years after issuance of advisories. Recent studies have reported an association between exposure to organochlorines and impaired blood-glucose regulation and diabetes. Several epidemiologic studies (Calvert et al. 1999; Pesatori et al. 1998; Vena et al. 1998) have shown that dioxin exposure is associated with elevated rates of diabetes and dysglycemia. U.S. Air Force veterans of Operation Ranch Hand, who applied Agent Orange in Vietnam, were exposed to dioxin. Exposure was associated with an elevated incidence of diabetes and was inversely associated with the length of time to diabetes onset (Henriksen et al. 1997). Cranmer et al. (2000) reported that dioxin exposure resulted in hyperinsulinemia and insulin resistance, and Fierens et al. (2003) reported significant odds ratios (ORs) of 5.1, 13.3, and 7.6 for risk of diabetes in relation to top decile concentrations of dioxins, coplanar PCBs, and 12 PCB markers. Longnecker et al. (2001) reported that pregnant women with diabetes had higher PCB levels than did nondiabetic pregnant women. Radikova et al. (2004) reported that PCB concentrations in a Slovak population were associated with elevated levels of blood glucose. Vasiliu et al. (2006) found a linear association between PCB serum levels and diabetes incidence in a large cohort in Michigan, and Lee et al. (2006) found a strong dose–response relationship between serum concentrations of six persistent organic pollutants [PCB-153, two dioxin congeners, oxychlordane, dichlorodiphenyldichloroethylene (DDE), and trans-nonachlor] and diabetes. Everett et al. (2006) reported an association between serum levels of both PCB-126 (a dioxin-like PCB) and p,p′-DDT (dichlorodiphenyltrichloroethane). DDE, the major metabolite of DDT, has previously been reported to be associated with diabetes (Glynn et al. 2003; Rylander et al. 2005), and hexachlorobenzene (HCB) was also linked to diabetes in cross-sectional studies (Glynn et al. 2003). Lee et al. (2007) have expanded their study to analyze the data from the sum of four dioxin-like PCB congeners and five nondioxin-like congeners, and report that the dioxin-like congeners showed the strongest relationship with diabetes. The present study was designed to investigate whether a relationship exists between diabetes and serum levels of total PCBs, two single PCB congeners, and the chlorinated pesticides DDE, HCB, and mirex in adult Mohawks.
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polychlorinated biphenyl pcb exposure assessment by multivariate statistical analysis of serum congener profiles in an adult native american population
Environmental Research, 2005Co-Authors: Anthony P. Decaprio, Alice Tarbell, Gayle S Morse, Azara L Santiagorivera, Glenn W Johnson, David O Carpenter, Jeffrey Robert Chiarenzelli, Maria J. SchymuraAbstract:Abstract The major determinants of human polychlorinated biphenyl (PCB) body burden include the source and route of exposure and the toxicokinetic processes occurring after uptake. However, the relative importance of each factor for individual subjects cannot currently be determined. The present study characterizes levels and patterns of PCB congeners in a large cohort of adult Akwesasne Mohawks with historical PCB exposure. Total serum PCB ranged from 0.29 to 48.32 ng/g and was higher in adult men than in women (median of 3.81 vs. 2.94 ng/g). The mean serum congener profile for the full cohort was dominated by persistent penta- to hepta-chlorinated biphenyls; several labile congeners were also prominent. In order to provide additional information on individual body burden determinants, multivariate exploratory data analysis techniques were applied to the congener-specific serum PCB data. A self-training receptor model, polytopic vector analysis (PVA), was employed to determine the number, composition, and relative proportions of independent congener patterns that contributed to the overall serum PCB profile for each Mohawk subject. PVA identified five such patterns, each of which was characterized by a unique mix of congeners. One pattern observed in a limited number of Mohawks was similar to those reported for air sampled near contaminated sediment deposits at Akwesasne and for volatilized Aroclor 1248 and is hypothesized to reflect recent inhalation exposure in these subjects. A second pattern was consistent with unaltered Aroclor 1254. A third pattern, resembling Aroclor 1262 but without labile congeners, was correlated with age and is interpreted as representing a lifetime PCB accumulation profile. The final two patterns were dominated by subsets of major persistent congeners and are hypothesized to reflect intermediate bioaccumulation profiles and/or differences in individual toxicokinetics. The results confirm the utility of a multivariate exploratory analysis approach to congener-specific PCB data and provide additional insight into the exposure and individual factors that determine PCB body burden in this population.