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1

Association Among Serum Perfluoroalkyl Chemicals, Glucose Homeostasis, and Metabolic Syndrome in Adolescents and Adults  

PubMed Central

OBJECTIVE Perfluoroalkyl chemicals (PFCs) have been used worldwide in a variety of consumer products. The effect of PFCs on glucose homeostasis is not known. RESEARCH DESIGN AND METHODS We examined 474 adolescents and 969 adults with reliable serum measures of metabolic syndrome profile from the National Health and Nutrition Examination Survey 1999–2000 and 2003–2004. RESULTS In adolescents, increased serum perfluorononanoic acid (PFNA) concentrations were associated with hyperglycemia (odds ratio [OR] 3.16 [95% CI 1.39–7.16], P < 0.05). Increased serum PFNA concentrations also have favorable associations with serum HDL cholesterol (0.67 [0.45–0.99], P < 0.05). Overall, increased serum PFNA concentrations were inversely correlated with the prevalence of the metabolic syndrome (0.37 [0.21–0.64], P < 0.005). In adults, increased serum perfluorooctanoic acid concentrations were significantly associated with increased ?-cell function (? coefficient 0.07 ± 0.03, P < 0.05). Increased serum perfluorooctane sulfate (PFOS) concentrations were associated with increased blood insulin (0.14 ± 0.05, P < 0.01), homeostasis model assessment of insulin resistance (0.14 ± 0.05, P < 0.01), and ?-cell function (0.15 ± 0.05, P < 0.01). Serum PFOS concentrations were also unfavorably correlated with serum HDL cholesterol (OR 1.61 [95% CI 1.15–2.26], P < 0.05). CONCLUSIONS Serum PFCs were associated with glucose homeostasis and indicators of metabolic syndrome. Further clinical and animal studies are warranted to clarify putative causal relationships. PMID:19114613

Lin, Chien-Yu; Chen, Pau-Chung; Lin, Yu-Chuan; Lin, Lian-Yu

2009-01-01

2

Positive Association Between Perfluoroalkyl Chemicals and Hyperuricemia in Children  

PubMed Central

Hyperuricemia in children is associated with increased risk of high blood pressure, metabolic syndrome, and future cardiovascular disease. Serum perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) levels have been shown to be positively associated with hyperuricemia in adults, but the association in children remains unexplored. We therefore examined the association between serum PFOA and PFOS levels and hyperuricemia in a representative sample of US children. A cross-sectional study was performed on 1,772 participants ?18 years of age from the National Health and Nutrition Examination Survey 1999–2000 and 2003–2008. The main outcome of interest was hyperuricemia, defined as serum uric acid levels ?6 mg/dL. We found that serum levels of PFOA and PFOS were positively associated with hyperuricemia, independent of age, sex, race/ethnicity, body mass index, annual household income, physical activity, serum total cholesterol, and serum cotinine levels. Compared with subjects in quartile 1 (referent), subjects in quartile 4 had multivariable-adjusted odds ratios for hyperuricemia of 1.62 (95% confidence interval: 1.10, 2.37) for PFOA and 1.65 (95% confidence interval: 1.10, 2.49) for PFOS. Our findings indicate that serum perfluoroalkyl chemical levels are significantly associated with hyperuricemia in children even at the lower “background” exposure levels of the US general population. PMID:23552989

Geiger, Sarah Dee; Xiao, Jie; Shankar, Anoop

2013-01-01

3

Perfluoroalkyl acids in blood serum samples from children in Taiwan.  

PubMed

Severe perfluoroalkyl acid (PFAA) contamination resulting from the fast-growing semiconductor, electrochemical, and optoelectronic industries has been determined in the river water in the vicinity of the Taipei area, Taiwan, during recent years. However, little is known about body burdens of the PFAA contaminations in local residents, especially children living in the Taipei area recently. In this study, ten target PFAA analytes consisted of three perfluorosulfonates (PFSAs) and seven perfluorocarboxylates (PFCAs) in the blood serum samples, collected from 225 healthy children with an average age of 13.6 years in the Taipei area from 2009 to 2010, were analyzed via high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). As the dominant PFAA contaminant in the blood serum samples from Taiwanese children, perfluorooctane sulfonate (PFOS) contributed 86% of all the target PFAA analytes, while the other nine analytes contributed less than 5% individually. PFOS showed the highest median up to 29 ng/mL, ranging from 0.03 to 148 ng/mL, which was higher than that observed in the serum samples collected from Taiwanese children between 2006 and 2008. Statistically, serum concentrations of perfluorobutane sulfonate (PFBS), perfluorohexane sulfonate (PFHxS), and perfluorooctanoic acid (PFOA) had significantly positive correlations with ages of children (p?serum PFBS, PFHxS, and PFOA concentrations in the male children were considerably higher than those in the female children (p?=?0.049, p?=?0.000, p?=?0.000). PMID:24622984

Bao, Jia; Lee, Yungling Leo; Chen, Pau-Chung; Jin, Yi-He; Dong, Guang-Hui

2014-06-01

4

Associations between serum perfluoroalkyl acids and LINE-1 DNA methylation.  

PubMed

Perfluoroalkyl acids (PFAAs) are persistent, synthetic compounds that are used in a number of consumer products. Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) have been associated with cardiovascular risk factors, and changes in gene expression and DNA methylation in animals and cellular systems. However, whether PFAA exposure is associated with LINE-1 DNA methylation, a potential marker of cardiovascular risk, in humans remains unknown. We sought to evaluate the cross-sectional associations between serum PFAAs and LINE-1 DNA methylation in a population highly exposed to PFOA. We measured serum PFAAs twice four to five years apart in 685 adult participants (47% male, mean age±SD=42±11years). We measured percent LINE-1 DNA methylation in peripheral blood leukocytes at the second time point (follow-up), and estimated absolute differences in LINE-1 methylation associated with an interquartile (IQR) shift in mean PFAA serum levels. IQR increases in mean serum PFOA, PFOS, perfluorononanoic acid (PFNA), and perfluorohexane sulfonate (PFHxS) were associated with differences of -0.04 (p=0.16), 0.20 (p=0.001), 0.06 (p=0.19), and 0.02 (p=0.57), respectively, in % LINE-1 methylation at follow-up after adjustment for potential confounders. We observed a monotonic increase in LINE-1 DNA methylation across tertiles of PFOS and PFNA (ptrend=0.02 for both associations), but not across tertiles of PFOA or PFHxS (ptrend=0.71 and 0.44, respectively). In summary, serum PFOS was associated with LINE-1 methylation, while serum PFOA, PFHxS, and PFNA were not. Additional research is needed to more precisely determine whether these compounds are epigenetically active. PMID:24263140

Watkins, Deborah J; Wellenius, Gregory A; Butler, Rondi A; Bartell, Scott M; Fletcher, Tony; Kelsey, Karl T

2014-02-01

5

No association between perfluoroalkyl chemicals and hypertension in children  

PubMed Central

Background Hypertension is a leading cause of cardiovascular disease worldwide. Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are perfluoroalkyl chemicals (PFCs) used in the manufacture of common consumer products and detected in the blood of the majority of Americans. Emerging biological data suggest that PFC exposure may have a role in the development of hypertension. However, the association between PFCs and hypertension has not yet been explored in humans. Therefore, we examined this association in a representative sample of US children. Methods A cross-sectional study was performed on 1,655 children from the National Health and Nutrition Examination Survey, 1999–2000 and 2003–2008. The main outcome of interest was hypertension, defined as age, height, and sex specific systolic and/or diastolic blood pressure level at the 95th percentile. Results We found no association between serum levels of PFOA and PFOS and hypertension in either unadjusted or multivariable-adjusted analyses controlling for age, sex, race-ethnicity, body mass index, annual household income, moderate activity, total serum cholesterol, and serum cotinine. Compared with the lowest quartile, the multivariable-adjusted odds ratio (95% confidence interval) of hypertension in the highest quartile of exposure was 0.69 (0.41–1.17) for PFOA and 0.77 (0.37–1.61) for PFOS (all P-trend values >0.30). Conclusion Our findings indicate that exposure to PFOA or PFOS is not significantly associated with hypertension in children at the lower PFC exposure levels typical of the general population. PMID:24520202

Geiger, Sarah Dee; Xiao, Jie; Shankar, Anoop

2014-01-01

6

Highly elevated serum concentrations of perfluoroalkyl substances in fishery employees from tangxun lake, china.  

PubMed

Increasing production and use of per- and polyfluoroalkyl substances (PFASs) has been reported from China, and a few studies have shown there are subpopulations in China with high and increasing exposure to these chemicals. In this paper, we present a comprehensive exposure assessment of PFASs in fishery employees from Tangxun Lake, China. Exceptionally high serum concentrations of C4 to C12 PFASs were observed in fishery employees (n = 39, median perfluorooctanesulfonic acid (PFOS) 10?400 ng/mL) compared to a reference group from the same city (n = 9, median PFOS 18.7 ng/mL). On the basis of the comparison of different exposure pathways, it was concluded that contaminated fish from Tangxun Lake was the primary source of PFAS exposure to fishery employees, and there was a positive association between serum PFAS concentrations and time of employment in the fishery. PFOS isomer profiles in fishery employees showed a significantly higher proportion of linear PFOS (78.4%) compared to the background-exposed reference group (66.8%), reflecting the highly linear PFOS isomer profile (>90%) of lake fish. Median renal clearance rates (CLrenal) of C4 to C10 perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkanesulfonic acids (PFSAs) ranged from 0.020 to 16.5 mL/day/kg and 0.013 to 9.43 mL/day/kg, respectively. PFCAs with less than eight perfluoroalkyl carbons were primarily eliminated via urine, whereas other routes of excretion may have contributed to the elimination for long-chain PFCAs and PFSAs. Calculated daily PFOS exposures of fishery employees significantly exceeded tolerable daily intake limits, but clinical blood chemistry parameters were mostly within normal reference ranges. However, additional epidemiological studies are needed to address potential associations between PFAS exposure and health effects in the Tangxun Lake area. PMID:24588690

Zhou, Zhen; Shi, Yali; Vestergren, Robin; Wang, Thanh; Liang, Yong; Cai, Yaqi

2014-04-01

7

Serum levels of perfluoroalkyl compounds in human maternal and umbilical cord blood samples  

Microsoft Academic Search

Perfluoroalkyl compounds (PFCs) are end-stage metabolic products from industrial flourochemicals used in the manufacture of plastics, textiles, and electronics that are widely distributed in the environment. The objective of the present study was to quantify exposure to perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA), perfluorodecanoic acid (PFDeA), perfluorohexane sulfonate (PFHxS), perfluoroheptanoic acid (PFHpA), and perfluorononanoic acid (PFNA) in serum samples collected from

Rocio Monroy; Katherine Morrison; Koon Teo; Stephanie Atkinson; Cariton Kubwabo; Brian Stewart; Warren G. Foster

2008-01-01

8

Serum perfluoroalkyl acids concentrations and memory impairment in a large cross-sectional study  

PubMed Central

Objectives To examine the cross-sectional association between serum perfluorooctanate (PFOA), perfuorooctane sulfonate (PFOS), perfluorononanoic acid (PFNA) and perfluorohexane sulfonate (PFHxS) concentrations with self-reported memory impairment in adults and the interaction of these associations with diabetes status. Design Cross-sectional study. Setting Population-based in Mid-Ohio Valley, West Virginia following contamination by a chemical plant. Participants The C8 Health Project collected data and measured the serum level of perfluoroalkyl acids (PFAAs) of 21?024 adults aged 50+ years. Primary outcome measure Self-reported memory impairment as defined by the question ‘have experienced short-term memory loss?’ Results A total of 4057 participants self-reported short-term memory impairment. Inverse associations between PFOS and PFOA and memory impairment were highly statistically significant with fully adjusted OR=0.93 (95% CI 0.90 to 0.96) for doubling PFOS and OR=0.96 (95% CI 0.94 to 0.98) for doubling PFOA concentrations. Comparable inverse associations with PFNA and PFHxS were of borderline statistical significance. Inverse associations of PFAAs with memory impairment were weaker or non-existent in patients with diabetes than overall in patients without diabetes. Conclusions An inverse association between PFAA serum levels and self-reported memory impairment has been observed in this large population-based, cross-sectional study that is stronger and more statistically significant for PFOA and PFOS. The associations can be potentially explained by a preventive anti-inflammatory effect exerted by a peroxisome proliferator-activated receptor agonist effect of these PFAAs, but confounding or even reverse causation cannot be excluded as an alternative explanation. PMID:23794579

Gallo, Valentina; Leonardi, Giovanni; Brayne, Carol; Armstrong, Ben; Fletcher, Tony

2013-01-01

9

Perfluoroalkyl Chemicals and Asthma among Children 12-19 Years of Age: NHANES (1999-2008)  

PubMed Central

Background: Perfluoroalkyl chemicals (PFCs) are a family of commonly used industrial chemicals whose persistence and ubiquity in human blood samples has led to concern about possible toxicity. Several animal studies and one recent human study have suggested a link between exposure to PFCs and asthma, although few epidemiologic studies have been conducted. Objectives: We investigated children’s PFC serum concentrations and their associations with asthma-related outcomes. Methods: We evaluated the association between serum concentrations of eight PFCs, including perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorononanoic acid (PFNA), and perfluorohexane sulfonic acid (PFHxS), with self-reported lifetime asthma, recent wheezing, and current asthma using data from participants 12–19 years of age from the 1999–2000 and 2003–2008 National Health and Nutrition Examination Surveys. Results: In multivariable-adjusted models, PFOA was associated with higher odds of ever having received a diagnosis of asthma [odds ratio (OR) = 1.18; 95% CI: 1.01, 1.39 for a doubling in PFOA], whereas for PFOS there were inverse relationships with both asthma and wheezing (OR = 0.88; 95% CI: 0.74, 1.04, and OR = 0.83; 95% CI: 0.67, 1.02, respectively). The associations were attenuated after accounting for sampling weights. No associations were seen between the other PFCs and any outcome. Conclusions: This cross-sectional study provides some evidence for associations between exposure to PFCs and asthma-related outcomes in children. The evidence is inconsistent, however, and prospective studies are needed. Citation: Humblet O, Diaz-Ramirez LG, Balmes JR, Pinney SM, Hiatt RA. 2014. Perfluoroalkyl chemicals and asthma among children 12–19 years of age: NHANES (1999–2008). Environ Health Perspect 122:1129–1133;?http://dx.doi.org/10.1289/ehp.1306606 PMID:24905661

Humblet, Olivier; Diaz-Ramirez, Ledif Grisell; Balmes, John R.; Pinney, Susan M.

2014-01-01

10

Serum levels of perfluoroalkyl compounds in human maternal and umbilical cord blood samples  

SciTech Connect

Perfluoroalkyl compounds (PFCs) are end-stage metabolic products from industrial flourochemicals used in the manufacture of plastics, textiles, and electronics that are widely distributed in the environment. The objective of the present study was to quantify exposure to perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA), perfluorodecanoic acid (PFDeA), perfluorohexane sulfonate (PFHxS), perfluoroheptanoic acid (PFHpA), and perfluorononanoic acid (PFNA) in serum samples collected from pregnant women and the umbilical cord at delivery. Pregnant women (n=101) presenting for second trimester ultrasound were recruited and PFC residue levels were quantified in maternal serum at 24-28 weeks of pregnancy, at delivery, and in umbilical cord blood (UCB; n=105) by liquid chromatography-mass spectrometry. Paired t-test and multiple regression analysis were performed to determine the relationship between the concentrations of each analyte at different sample collection time points. PFOA and PFOS were detectable in all serum samples analyzed including the UCB. PFOS serum levels (mean{+-}S.D.) were significantly higher (p<0.001) in second trimester maternal serum (18.1{+-}10.9 ng/mL) than maternal serum levels at delivery (16.2{+-}10.4 ng/mL), which were higher than the levels found in UCB (7.3{+-}5.8 ng/mL; p<0.001). PFHxS was quantifiable in 46/101 (45.5%) maternal and 21/105 (20%) UCB samples with a mean concentration of 4.05{+-}12.3 and 5.05{+-}12.9 ng/mL, respectively. There was no association between serum PFCs at any time point studied and birth weight. Taken together our data demonstrate that although there is widespread exposure to PFCs during development, these exposures do not affect birth weight.

Monroy, Rocio [Department of Obstetrics and Gynecology, McMaster University, HSC-3N52D, 1200 Main Street West, Hamilton, Ontario, L8N 3Z5 (Canada); Morrison, Katherine [Department of Pediatrics, McMaster University, HSC-3N52D, 1200 Main Street West, Hamilton, Ontario, L8N 3Z5 (Canada); Teo, Koon [Department of Medicine, McMaster University, HSC-3N52D, 1200 Main Street West, Hamilton, Ontario, L8N 3Z5 (Canada); Atkinson, Stephanie [Department of Pediatrics, McMaster University, HSC-3N52D, 1200 Main Street West, Hamilton, Ontario, L8N 3Z5 (Canada); Kubwabo, Cariton; Stewart, Brian [Chemistry Research Division, Safe Environments Programme, Health Canada, Ottawa, Ontario (Canada); Foster, Warren G. [Department of Obstetrics and Gynecology, McMaster University, HSC-3N52D, 1200 Main Street West, Hamilton, Ontario, L8N 3Z5 (Canada)], E-mail: fosterw@mcmaster.ca

2008-09-15

11

Serum levels of perfluoroalkyl compounds in human maternal and umbilical cord blood samples.  

PubMed

Perfluoroalkyl compounds (PFCs) are end-stage metabolic products from industrial flourochemicals used in the manufacture of plastics, textiles, and electronics that are widely distributed in the environment. The objective of the present study was to quantify exposure to perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA), perfluorodecanoic acid (PFDeA), perfluorohexane sulfonate (PFHxS), perfluoroheptanoic acid (PFHpA), and perfluorononanoic acid (PFNA) in serum samples collected from pregnant women and the umbilical cord at delivery. Pregnant women (n=101) presenting for second trimester ultrasound were recruited and PFC residue levels were quantified in maternal serum at 24-28 weeks of pregnancy, at delivery, and in umbilical cord blood (UCB; n=105) by liquid chromatography-mass spectrometry. Paired t-test and multiple regression analysis were performed to determine the relationship between the concentrations of each analyte at different sample collection time points. PFOA and PFOS were detectable in all serum samples analyzed including the UCB. PFOS serum levels (mean+/-S.D.) were significantly higher (p<0.001) in second trimester maternal serum (18.1+/-10.9 ng/mL) than maternal serum levels at delivery (16.2+/-10.4 ng/mL), which were higher than the levels found in UCB (7.3+/-5.8 ng/mL; p<0.001). PFHxS was quantifiable in 46/101 (45.5%) maternal and 21/105 (20%) UCB samples with a mean concentration of 4.05+/-12.3 and 5.05+/-12.9 ng/mL, respectively. There was no association between serum PFCs at any time point studied and birth weight. Taken together our data demonstrate that although there is widespread exposure to PFCs during development, these exposures do not affect birth weight. PMID:18649879

Monroy, Rocio; Morrison, Katherine; Teo, Koon; Atkinson, Stephanie; Kubwabo, Cariton; Stewart, Brian; Foster, Warren G

2008-09-01

12

Concentrations of perfluoroalkyl compounds in the serum and milk of lactating North Carolina women  

EPA Science Inventory

Perfluoroalkyl acids (PFAAs) and their derivatives are ubiquitous environmental contaminants that have been detected in a multitude of terrestrial and aquatic organisms. Some PFAAs bind the human estrogen receptors in vitro. Further, some PFAAs induce estrogen responsive genes a...

13

Profiles of perfluoroalkyl substances in the liver and serum of patients with liver cancer and cirrhosis in Australia.  

PubMed

The present cross-sectional study investigated 12 perfluoroalkyl substances (PFASs) in serum (n=79) and liver (n=66) samples from patients who had undergone liver transplantation for a range of conditions, such as hepatocellular carcinoma (HCC), cirrhosis due to chronic hepatitis C viral infection (HCV), both HCC and HCV, amyloidosis or acute liver failure. PFAS data from patients were compared to those in control serum (n=25) samples from liver donors with no known liver disease and to those in control liver (n=9) tissues collected during liver resection surgery. All samples showed detectable PFOS (serum: 0.621-126ng/mL; liver: 0.375-42.5ng/g wet wt) and PFOA (serum: 0.437-45.5ng/mL; liver: 0.101-2.25ng/g wet wt) concentrations. In general, in paired serum and liver samples, serum had higher PFOS, PFHxS, PFDA, PFNA, and PFOA concentrations than those in explanted livers from patients. These findings also suggest that pathological changes in diseased livers alter the distribution of PFASs between liver and serum. The results from control serum (2007-2008) suggested that PFOS, PFHxS, PFOA, and PFNA concentrations were lower than those previously reported from Australia for 2002-2003, and 2006-2007. The present study demonstrates, for the first time, the detection and comparison of a range of PFASs in the liver of patients with liver cancer and/or liver cirrhosis. PMID:23849467

Yeung, Leo W Y; Guruge, Keerthi S; Taniyasu, Sachi; Yamashita, Nobuyoshi; Angus, Peter W; Herath, Chandana B

2013-10-01

14

Thyroid Function and Perfluoroalkyl Acids in Children Living Near a Chemical Plant  

PubMed Central

Background: Animal studies suggest that some perfluoroalkyl acids (PFAAs), including perfluorooctanoate (PFOA), perfluorooctane sulfonate (PFOS), and perfluorononanoic acid (PFNA) may impair thyroid function. Epidemiological findings, mostly related to adults, are inconsistent. Objectives: We investigated whether concentrations of PFAAs were associated with thyroid function among 10,725 children (1–17 years of age) living near a Teflon manufacturing facility in the Mid-Ohio Valley (USA). Methods: Serum levels of thyroid-stimulating hormone (TSH), total thyroxine (TT4), and PFAAs were measured during 2005–2006, and information on diagnosed thyroid disease was collected by questionnaire. Modeled in utero PFOA concentrations were based on historical information on PFOA releases, environmental distribution, pharmacokinetic modeling, and residential histories. We performed multivariate regression analyses. Results: Median concentrations of modeled in utero PFOA and measured serum PFOA, PFOS, and PFNA were 12, 29, 20, and 1.5 ng/mL, respectively. The odds ratio for hypothyroidism (n = 39) was 1.54 [95% confidence interval (CI): 1.00, 2.37] for an interquartile range (IQR) contrast of 13 to 68 ng/mL in serum PFOA measured in 2005–2006. However, an IQR shift in serum PFOA was not associated with TSH or TT4 levels in all children combined. IQR shifts in serum PFOS (15 to 28 ng/mL) and serum PFNA (1.2 to 2.0 ng/mL) were both associated with a 1.1% increase in TT4 in children 1–17 years old (95% CIs: 0.6, 1.5 and 0.7, 1.5 respectively). Conclusions: This is the first large-scale report in children suggesting associations of serum PFOS and PFNA with thyroid hormone levels and of serum PFOA and hypothyroidism. PMID:22453676

Mondal, Debapriya; Armstrong, Ben; Bloom, Michael S.; Fletcher, Tony

2012-01-01

15

Association between Maternal Serum Perfluoroalkyl Substances during Pregnancy and Maternal and Cord Thyroid Hormones: Taiwan Maternal and Infant Cohort Study  

PubMed Central

Background: Perfluoroalkyl substances (PFASs) are synthetic compounds that are widely used in industry and are often detectable in humans. In pregnant rats and their pups, PFASs can interfere with thyroid hormone homeostasis. In humans, maternal thyroid hormones supply the fetus throughout pregnancy, and thyroid hormones play a critical role in fetal growth and neurodevelopment. Objectives: We investigated the association between maternal PFAS exposure and thyroid hormone status in pregnant women and neonates. Methods: In a study of environmental exposure and health in Taiwan, we measured serum concentrations of nine PFASs and four thyroid hormones for 285 pregnant women in their third trimester, and also measured cord serum thyroid hormones for 116 neonates. Associations between maternal PFASs and maternal and cord thyroid hormones were examined in multiple linear regression models. Results: Perfluorohexanesulfonic acid concentrations were positively associated with maternal thyroid-stimulating hormone (TSH) levels. Pregnant women with higher levels of perfluorononanoic acid (PFNA), perfluoroundecanoic acid (PFUnDA), and perfluorododecanoic acid (PFDoDA) had lower free thyroxine (T4) and total T4 levels. For example, we estimated that maternal free T4 levels decreased 0.019 ng/dL (95% CI: –0.028, –0.009) with each nanogram per milliliter increase in maternal PFNA. Finally, maternal PFNA, PFUnDA, and PFDoDA levels were associated with lower cord total triiodothyronine (T3) and total T4 levels, and maternal perfluorodecanoic acid (PFDeA) was associated with lower cord total T3. Conclusions: Our results suggest that exposure to some PFASs during pregnancy may interfere with thyroid hormone homeostasis in pregnant women and fetuses. Citation: Wang Y, Rogan WJ, Chen PC, Lien GW, Chen HY, Tseng YC, Longnecker MP, Wang SL. 2014. Association between maternal serum perfluoroalkyl substances during pregnancy and maternal and cord thyroid hormones: Taiwan Maternal and Infant Cohort Study. Environ Health Perspect 122:529–534;?http://dx.doi.org/10.1289/ehp.1306925 PMID:24577800

Rogan, Walter J.; Chen, Pau-Chung; Lien, Guang-Wen; Chen, Hsiao-Yen; Tseng, Ying-Chih; Longnecker, Matthew P.

2014-01-01

16

A simple and rapid extraction method for sensitive determination of perfluoroalkyl substances in blood serum suitable for exposure evaluation.  

PubMed

In this work, we propose a microextraction method based on a new supramolecular solvent (SUPRAS) made up of reverse aggregates of hexanoic acid, combined with liquid chromatography/triple quadrupole mass spectrometry (LC/QQQ MS-MS) for the determination of the perfluoroalkyl substances (PFASs) in blood serum. A SUPRAS is a nano-structured liquid made up of surfactant aggregates synthesized through a self-assembly process. The method involved the acidification of 765 ?L of blood serum (600 ?mol of hydrochloric acid per mL of serum) followed by the addition of hexanoic acid (97 ?L) and tetrahydrofuran (THF) (600 ?L), conditions under which the supramolecular solvent (?360 ?L) formed in situ after vortex-shaking and centrifugation. Parameters affecting extraction efficiency and concentration factors were studied. The overall sample treatment took only 20 min and several samples (20-30) can be simultaneously analyzed using conventional lab equipments, making additional investments unnecessary. Recoveries for the internal standards in samples ranged from 75 to 89% with relative standard deviations between 1 and 15%. Calibration was based on the use of internal standards. The method was very sensitive with detection limits ranging from 2 to 20 pg mL(-1) for PFASs. The approach developed was successfully applied to the determination of PFASs in different blood serum samples. The concentration of PFASs found in samples of animal origin ranged between 17 and 197.3 pg mL(-1) and between 84 and 5168 pg mL(-1) in samples of human origin. Both the analytical and operational features of this method make it suitable for the evaluation of exposure to PFASs. PMID:22420956

Luque, Noelia; Ballesteros-Gómez, Ana; van Leeuwen, Stefan; Rubio, Soledad

2012-04-27

17

Polybrominated diphenyl ethers and perfluoroalkyl substances in serum of pregnant women: levels, correlations, and potential health implications.  

PubMed

Polybrominated diphenyl ethers (PBDEs), a group of flame retardants, and perfluoroalkyl substances (PFASs) were analysed in serum samples of pregnant women from Denmark to provide information about their exposure and to study indications of common exposure pathways. The main BDE congener was the fully brominated BDE-209 with a median value of 7.5 ng/g lipid (46 pg/mL; 9.8 pmol/g lipid). Other BDE congeners decreased in the order BDE-47 > BDE-99 > BDE-153. The summed concentration of tri- to hepta-BDEs was 7.7 ng/g lipid, i.e. in the higher end of previously reported concentrations from Europe, including plasma samples of pregnant Danish women. Total lipid contents were relatively low, on average 5.9 g/L (9.0 mmol/L). The main PFAS compound was perfluorooctane sulfonate with a median concentration of 8.4 ng/mL. Other PFASs decreased in the order perfluorooctanoic acid > perfluorononanoic acid > perfluorodecanoic acid > perfluorohexane sulfonate and resulted in a ?PFAS of 12 ng/mL. Within each group, compounds were highly intercorrelated with the exception of BDE-209, which was not correlated with any of the other compounds. No correlations were found either between PFASs and PBDEs suggesting different sources of exposure and/or pharmacokinetic and metabolisation processes. PBDE and PFAS concentrations were in the range associated with adverse effects in some epidemiological studies. PMID:24435476

Vorkamp, Katrin; Nielsen, Flemming; Kyhl, Henriette Boye; Husby, Steffen; Nielsen, Lars Bo; Barington, Torben; Andersson, Anna-Maria; Jensen, Tina Kold

2014-07-01

18

Loss and in situ production of perfluoroalkyl chemicals in outdoor biosolids-soil mesocosms.  

PubMed

An outdoor mesocosm study was conducted in Baltimore, Maryland, to explore the fate of thirteen perfluoroalkyl substances (PFASs) over the course of three years in biosolids/soil mixtures (1:2) exposed to ambient outdoor conditions. Analysis by liquid chromatography tandem mass spectrometry showed perfluorooctanoate (PFOA) to be the most abundant analyte found early in the soil weathering experiment at 24.1 ng/g dry weight (dw), followed by perfluoroundecanoate (PFUnDA) and perfluorodecanoate (PFDA) at 18.4 and 17.4 ng/g dw, respectively. Short-chain perfluorinated carboxylates (PFCAs; C4-C8) showed observable loss from biosolids/soil mixtures, with experimentally determined first-order half-lives in soil ranging from 385 to 866 days. Perfluorooctane sulfonate (PFOS), perfluorononaoate (PFNA) and PFUnDA levels in biosolids/soil mixtures remained stable, while other long-chain PFCAs [PFDA, perfluorododecanoate (PFDoDA)] and perfluorooctane sulfonamide (PFOSA) levels increased over time, presumably due to the breakdown of unidentified precursors in a process analogous to that reported previously for wastewater treatment plants. This study informs risk assessment initiatives by furnishing data on the environmental persistence of PFASs while also constituting the first report on in situ production of long-chained PFASs in terrestrial environments. PMID:24834828

Venkatesan, Arjun K; Halden, Rolf U

2014-07-01

19

Changes in serum concentrations of maternal poly- and perfluoroalkyl substances over the course of pregnancy and predictors of exposure in a multiethnic cohort of Cincinnati, Ohio pregnant women during 2003-2006.  

PubMed

Data on predictors of gestational exposure to poly- and perfluoroalkyl substances (PFASs) in the United States are limited. To fill in this gap, in a multiethnic cohort of Ohio pregnant women recruited in 2003-2006, we measured perfluorooctanesulfonate (PFOS), perfluorooctanoate (PFOA), and six additional PFASs in maternal serum at ?16 weeks gestation (N = 182) and delivery (N = 78), and in umbilical cord serum (N = 202). We used linear regression to examine associations between maternal serum PFASs concentrations and demographic, perinatal, and lifestyle factors. PFASs concentrations in maternal sera and in their infants' cord sera were highly correlated (Spearman rank correlation coefficients = 0.73-0.95). In 71 maternal-infant dyads, unadjusted geometric mean (GM) concentrations (95% confidence interval) (in ?g/L) in maternal serum at delivery of PFOS [8.50 (7.01-9.58)] and PFOA [3.43 (3.01-3.90)] were significantly lower than at 16 weeks gestation [11.57 (9.90-13.53], 4.91 (4.32-5.59), respectively], but higher than in infants' cord serum [3.32 (2.84-3.89), 2.85 (2.51-3.24), respectively] (P < 0.001). Women who were parous, with a history of previous breastfeeding, black, or in the lowest income category had significantly lower PFOS and PFOA GM concentrations than other women. These data suggest transplacental transfer of PFASs during pregnancy and nursing for the first time in a U.S. birth cohort. PMID:25026485

Kato, Kayoko; Wong, Lee-Yang; Chen, Aimin; Dunbar, Carmen; Webster, Glenys M; Lanphear, Bruce P; Calafat, Antonia M

2014-08-19

20

Current Understanding of Perfluoroalkyl Acid Toxicology  

EPA Science Inventory

The perfluoroalkyl acids (PFAAs) are a family of organic chemicals consisting of a perfluorinated carbon backbone (4-14 carbons in length) and an anionic head group (sulfonate, carboxylate or phosphonate). These compounds have excellent surface-tension reducing properties and hav...

21

Perfluoroalkyl acids : Recent activities and research progress  

EPA Science Inventory

The perfluoroalkyl acids (PFAAs) are a family of man-made fluorinated organic chemicals consisting of a carbon backbone typically of four to fourteen in length and a charged functional moiety (primarily carboxylate, sulfonate or phosphonate). The two most widely known PFAAs are ...

22

Improved selectivity for the analysis of maternal serum and cord serum for polyfluoroalkyl chemicals  

Microsoft Academic Search

Perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid, two of the most widely studied polyfluoroalkyl chemicals (PFCs), can cross the placenta. Therefore, data on the exposure to PFCs of the very young are needed to evaluate the potential health effects associated with such exposure. Human serum, especially serum collected from pregnant women and cord serum, may contain endogenous components that can

Kayoko Kato; Brian J. Basden; Larry L. Needham; Antonia M. Calafat

2011-01-01

23

Exposure to Perfluoroalkyl Acids and Markers of Kidney Function among Children and Adolescents Living near a Chemical Plant  

PubMed Central

Background: Serum levels of perfluorooctanoic acid (PFOA) have been associated with decreased renal function in cross-sectional analyses, but the direction of the association is unclear. Objectives: We examined the association of measured and model-predicted serum PFOA concentrations with estimated glomerular filtration rate (eGFR), a marker of kidney function, in a highly exposed population (median serum PFOA, 28.3 ng/mL). Methods: We measured serum creatinine, PFOA, perfluorooctane sulfonate (PFOS), perfluorononanoic acid (PFNA), and perfluorohexane sulfonate (PFHxS) and calculated eGFR in 9,660 children 1 to < 18 years of age at study enrollment. We predicted concurrent and historical serum PFOA concentrations using a validated environmental, exposure, and pharmacokinetic model based on individual residential histories, and used linear regression to estimate the association between eGFR and measured and predicted serum PFOA concentrations. We hypothesized that predicted serum PFOA levels would be less susceptible to reverse causation than measured levels. Results: An interquartile range increase in measured serum PFOA concentrations [IQR ln(PFOA) = 1.63] was associated with a decrease in eGFR of 0.75 mL/min/1.73 m2 (95% CI: –1.41, –0.10; p = 0.02). Measured serum levels of PFOS, PFNA, and PFHxS were also cross-sectionally associated with decreased eGFR. In contrast, predicted serum PFOA concentrations at the time of enrollment were not associated with eGFR (–0.10; 95% CI: –0.80, 0.60; p = 0.78). Additionally, predicted serum PFOA levels at birth and during the first ten years of life were not related to eGFR. Conclusions: Our findings suggest that the cross-sectional association between eGFR and serum PFOA observed in this and prior studies may be a consequence of, rather than a cause of, decreased kidney function. PMID:23482063

Josson, Jyoti; Elston, Beth; Bartell, Scott M.; Shin, Hyeong-Moo; Vieira, Veronica M.; Savitz, David A.; Fletcher, Tony; Wellenius, Gregory A.

2013-01-01

24

TOXICOGENOMIC STUDY OF TRIAZOLE FUNGICIDES AND PERFLUOROALKYL ACIDS IN RAT LIVERS ACCURATELY CATEGORIZES CHEMICALS AND IDENTIFIES MECHANISMS OF TOXICITY  

EPA Science Inventory

Toxicogenomic analysis of five environmental chemicals was performed to investigate the ability of genomics to predict toxicity, categorize chemicals, and elucidate mechanisms of toxicity. Three triazole antifungals (myclobutanil, propiconazole, and triadimefon) and two perfluori...

25

Breastfeeding: A Potential Excretion Route for Mothers and Implications for Infant Exposure to Perfluoroalkyl Acids  

PubMed Central

Background: The presence of perfluoroalkyl acids (PFAAs) in breast milk has been documented, but their lactational transfer has been rarely studied. Determination of the elimination rates of these chemicals during breastfeeding is important and critical for assessing exposure in mothers and infants. Objectives: We aimed to investigate the association between breastfeeding and maternal serum concentrations of perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), perfluorononanoic acid (PFNA), and perfluorohexane sulfonate (PFHxS). For a subset of the population, for whom we also have their infants’ measurements, we investigated associations of breastfeeding with infant serum PFAA concentrations. Methods: The present analysis included 633 women from the C8 Science Panel Study who had a child < 3.5 years of age and who provided blood samples and reported detailed information on breastfeeding at the time of survey. PFAA serum concentrations were available for all mothers and 8% (n = 49) of the infants. Maternal and infant serum concentrations were regressed on duration of breastfeeding. Results: Each month of breastfeeding was associated with lower maternal serum concentrations of PFOA (–3%; 95% CI: –5, –2%), PFOS (–3%; 95% CI: –3, –2%), PFNA (–2%; 95% CI: –2, –1%), and PFHxS (–1%; 95% CI: –2, 0%). The infant PFOA and PFOS serum concentrations were 6% (95% CI: 1, 10%) and 4% (95% CI: 1, 7%) higher per month of breastfeeding. Conclusions: Breast milk is the optimal food for infants, but is also a PFAA excretion route for lactating mothers and exposure route for nursing infants. Citation: Mondal D, Weldon RH, Armstrong BG, Gibson LJ, Lopez-Espinosa MJ, Shin HM, Fletcher T. 2014. Breastfeeding: a potential excretion route for mothers and implications for infant exposure to perfluoroalkyl acids. Environ Health Perspect 122:187–192;?http://dx.doi.org/10.1289/ehp.1306613 PMID:24280536

Mondal, Debapriya; Weldon, Rosana Hernandez; Armstrong, Ben G.; Gibson, Lorna J.; Lopez-Espinosa, Maria-Jose; Shin, Hyeong-Moo

2013-01-01

26

CHEMICAL VERSUS SERUM TREATMENT OF EPIDEMIC MENINGITIS.  

PubMed

Claims of efficiency have been made at two widely separated periods for the chemical treatment of epidemic meningitis, in the first instance for lysol and in the second for protargol. The use of lysol was long since abandoned; the recommendation for protargol is based on a single series of cases, small in number. Because of the variable severity of epidemics of meningitis, small reliance can be placed on results of treatment limited in extent to small numbers of cases and to one locality. A more uniform and accurate measure of the value of a method of treatment is provided by animals infected experimentally with pathogenic cultures of meningococci. Young guinea pigs respond in a definite manner to intraperitoneal inoculation of virulent meningococci. Neither protargol nor lysol proved to have any curative action on the experimental infection thus produced in these animals. Monkeys respond in a characteristic manner to the inoculation of virulent cultures into the subarachnoid space. Protargol displayed no curative action on the experimental infection thus produced in these animals. On the contrary, both lysol and protargol exert antileukotactic and antiphagocytic effects, and are also potent protoplasmic poisons, and the leukocytes with which they come in contact are injured and made to degenerate. According to the extent to which these harmful properties are exerted, the chemicals promote the advance rather than restrain the progress of meningococcic infection. Recovery from meningococcic infection in man and animals is accomplished chiefly through the process of phagocytosis. The specific antiserum acts curatively by increasing the emigration of leukocytes, by promoting phagocytosis directly, and by agglutinating the meningococci, and also by neutralizing endotoxin. Any means which interfere with and reduce these essential processes retard or prevent recovery. Both lysol and protargol interfere with and diminish the emigration of leukocytes and the phagocytosis of meningococci, and neither possesses antitoxic power. The mixture of antiserum with lysol and with protargol reduces to a certain extent the antileukotactic and antiphagocytic effect of the chemicals; but this action is insufficient to set aside wholly the injurious effects which they produce. It follows, therefore, that whatever theoretical advantages might accrue from a bactericidal activity exerted by these chemicals independently of the type of meningococcus causing epidemic meningitis, is more than offset by the harmful effects which they cause. Hence specific antiserum seems to provide the logical therapeutic agent with which to combat epidemic meningitis, since it is itself innocuous and promotes those processes essential to recovery from the disease. The problem up to the present has been that of producing an antiserum which represents the several types of the meningococcus, and this problem is now in a fair way to being solved. PMID:19868017

Flexner, S; Amoss, H L

1916-05-01

27

Mechanism of perfluoroalkyl halide toxicity: catalysis of perfluoroalkylation by reduced forms of cobalamin (vitamin B12).  

PubMed

Perfluoroalkyl halides (PFHs) are synthetic products widely used in various fields. Perfluorooctyl bromide (PFB) is used in medicine as a component of blood substitutes and for artificial lung ventilation. In both cases, it is considered a completely inert compound acting as a solvent for oxygen. However, there are many reports of PFH-induced intoxication, including lethal cases. Mechanisms underlying toxic effects of this compound remain unknown. In this study, we demonstrate that the reduced form of cobalamin (vitamin B12) typical for B12-dependent enzymes can catalyze the reactions of perfluoroalkylation, aromatic substitution, or addition by double bonds. Synthesis of perfluoro derivatives from PFHs during catalysis by cob(I)alamin-like super nucleophiles is a new possible mechanism responsible for in vivo formation of highly toxic compounds from "chemically inert" substances widely used in medicine. Catalytic perfluoroalkylation might possibly contribute to nitric oxide depletion and modulation of activity of guanylate cyclase, cytochromes, NO-synthases, and other heme-containing proteins. PMID:14756634

Beda, N V; Nedospasov, A A

2003-12-01

28

Polyfluoroalkyl chemicals in the serum and milk of breastfeeding women  

Microsoft Academic Search

Polyfluoroalkyl chemicals (PFCs) comprise a group of man-made organic compounds, some of which are persistent contaminants with developmental toxicity shown in laboratory animals. There is a paucity of human perinatal exposure data. The US EPA conducted a pilot study (Methods Advancement for Milk Analysis) including 34 breastfeeding women in North Carolina. Milk and serum samples were collected at 2–7 weeks

Ondine S. von Ehrenstein; Suzanne E. Fenton; Kayoko Kato; Zsuzsanna Kuklenyik; Antonia M. Calafat; Erin P. Hines

2009-01-01

29

Aromatic and heterocyclic perfluoroalkyl sulfides. Methods of preparation  

PubMed Central

Summary This review covers all of the common methods for the syntheses of aromatic and heterocyclic perfluoroalkyl sulfides, a class of compounds which is finding increasing application as starting materials for the preparation of agrochemicals, pharmaceutical products and, more generally, fine chemicals. A systematic approach is taken depending on the mode of incorporation of the SRF groups and also on the type of reagents used. PMID:20978611

2010-01-01

30

Chemical labelling of active serum thioester proteins for quantification  

PubMed Central

The complement serum proteins C3 and C4 and the protease inhibitor ?-2 macroglobulin are all members of the C3/?-2M thioester protein family, an evolutionarily ancient and conserved family that contains an intrachain thioester bond. The chemistry of the thioester bond is a key to the function of the thioester proteins. All these proteins function by covalently linking to their target by acyl transfer of the protein via the thioester moiety. We show that the signature thioester bond can be targeted with nucleophiles linked to a bioreporter molecule, site-specifically modifying the whole, intact thioester protein. Conditions were optimised to label selectively and efficiently pull-down unprocessed thioester-containing proteins from serum. We demonstrated pull-down of full-length C3, ?-2M and C4 from sera in high salt, using a biotinylated nucleophile and streptavidin-coated resin, confirmed by MALDI-TOF MS identification of the gel bands. The potential for the development of a quantitative method for measuring active C3 in serum was investigated in patient sera pre and post operation. Quantifying active C3 in clinical assays using current methods is difficult. Methods based on antibody detection (e.g. nephelometry) do not distinguish between active C3 and inactive breakdown products. C3-specific haemolytic assays can be used, but these require use of relatively unstable reagents. The current work represents a promising robust, enzyme- and antibody-free chemical method for detecting active thioester proteins in blood, plasma or serum. PMID:21852021

Holm, Lotta; Ackland, Gareth L.; Edwards, Mark R.; Breckenridge, Ross A.; Sim, Robert B.; Offer, John

2012-01-01

31

Do Perfluoroalkyl Compounds Impair Human Semen Quality?  

PubMed Central

Background Perfluoroalkyl acids (PFAAs) are found globally in wildlife and humans and are suspected to act as endocrine disruptors. There are no previous reports of PFAA levels in adult men from Denmark or of a possible association between semen quality and PFAA exposure. Objectives We investigated possible associations between PFAAs and testicular function. We hypothesized that higher PFAA levels would be associated with lower semen quality and lower testosterone levels. Methods We analyzed serum samples for levels of 10 different PFAAs and reproductive hormones and assessed semen quality in 105 Danish men from the general population (median age, 19 years). Results Considerable levels of perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and perfluorohexane sulfonic acid were found in all young men (medians of 24.5, 4.9, and 6.6 ng/mL, respectively). Men with high combined levels of PFOS and PFOA had a median of 6.2 million normal spermatozoa in their ejaculate in contrast to 15.5 million among men with low PFOS–PFOA (p = 0.030). In addition, we found nonsignificant trends with regard to lower sperm concentration, lower total sperm counts, and altered pituitary–gonadal hormones among men with high PFOS–PFOA levels. Conclusion High PFAA levels were associated with fewer normal sperm. Thus, high levels of PFAAs may contribute to the otherwise unexplained low semen quality often seen in young men. However, our findings need to be corroborated in larger studies. PMID:19590684

Joensen, Ulla Nordström; Bossi, Rossana; Leffers, Henrik; Jensen, Allan Astrup; Skakkebæk, Niels E.; Jørgensen, Niels

2009-01-01

32

TOWARD A RISK ASSESSMENT OF PERFLUOROALKYL ACIDS  

EPA Science Inventory

Perfluoroalkyl acids (PFAA) such as perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS),and fluorotelomer alcoholsare surfactants that have wide applications in industrial and consumer products. Various fluorotelomer alcohols are known to be metabolized to perfluo...

33

Perfluoroalkyl polytriazines containing pendent iododifluoromethyl groups  

NASA Technical Reports Server (NTRS)

New perfluoroalkyl polytriazines containing pendent iododifluoromethyl groups are prepared by the reaction of perfluoroalkyl dinitriles with ammonia to form poly(imidoylamidines), followed by the cyclization of the imidoylamidine groups with, e.g., various mixtures of a perfluoroacyl fluoride with an omega iodoperfluoroacyl fluoride. The polytriazines obtained can be cured by heat which causes crosslinking at the iododifluoromethyl groups by elimination of iodine and formation of carbon-to-carbon bonds.

Rosser, R. W.; Psarras, T. (inventors)

1980-01-01

34

High Lipophilicty of Perfluoroalkyl Carboxylate and Sulfonate  

PubMed Central

Here we report on remarkably high lipophilicity of perfluoroalkyl carboxylate and sulfonate. A lipophilic nature of this emerging class of organic pollutants has been hypothesized as an origin of their bioaccumulation and toxicity. Both carboxylate and sulfonate, however, are considered hydrophilic while perfluroalkyl groups are not only hydrophobic but also oleophobic. Partition coefficients of homologous series of perfluoroalkyl and alkyl carboxylates between water and n-octanol were determined as a measure of their lipophilicity by ion-transfer cyclic voltammetry. Very similar lipophilicity of perfluoroalkyl and alkyl chains with the same length is demonstrated experimentally for the first time by fragment analysis of the partition coefficients. This finding is important for pharmaceutical and biomedical applications of perfluoroalkyl compounds. Interestingly, ?2 orders of magnitude higher lipophilicity of a perfluoroalkyl carboxylate or sulfonate in comparison to its alkyl counterpart is ascribed nearly exclusively to their oxoanion groups. The higher lipophilicity originates from a strong electron-withdrawing effect of the perfluoroalkyl group on the adjacent oxoanion group, which is weakly hydrated to decrease its hydrophilicity. In fact, the inductive effect is dramatically reduced for a fluorotelomer with an ethylene spacer between perfluorohexyl and carboxylate groups, which is only as lipophilic as its alkyl counterpart, nonanoate, and is 400 times less lipophilic than perfluorononanoate. The high lipophilicity of perfluoroalkyl carboxylate and sulfonate implies that their permeation across such a thin lipophilic membrane as a bilayer lipid membrane is limited by their transfer at a membrane/water interface. The limiting permeability is lower and less dependent on their lipophilicity than the permeability controlled by their diffusion in the membrane interior as assumed in the classical solubility-diffusion model. PMID:19170492

Jing, Ping; Rodgers, Patrick J.; Amemiya, Shigeru

2009-01-01

35

Effect of temperature and duration of storage on the stability of polyfluoroalkyl chemicals in human serum.  

PubMed

We assessed the potential impact of temperature on the long-term stability of several polyfluoroalkyl chemicals in serum. We evaluated the concentrations of perfluorooctane sulfonate, perfluorohexane sulfonate, perfluorooctanoate and perfluorononanoate in 16 human serum samples stored at room temperature, 5 °C, -20 °C and -70 °C at several time points during an eight month period. Concentrations of the target analytes remained unchanged under all studied conditions, even when serum was kept at room temperature for 10 days. PMID:23232044

Kato, Kayoko; Wong, Lee-Yang; Basden, Brian J; Calafat, Antonia M

2013-04-01

36

Level and temporal trend of perfluoroalkyl acids in Greenlandic Inuit  

PubMed Central

Objectives Perfluoroalkyl acids (PFAAs) have been detected in human blood, breast milk and umbilical cord blood across the globe. PFAAs do accumulate in the marine food chain in Arctic regions. In Greenland, increasing PFAA concentrations were observed during 1982–2006 in ringed seals and polar bears. However, until now, no data have been reported for PFAAs in Greenlandic Inuit. This study assesses the level and temporal trend of serum PFAAs in Greenlandic Inuit. Study design Cross-section and temporal time trend survey. Methods Serum PFAA levels were determined in 284 Inuit from different Greenlandic districts using liquid chromatography-tandem mass spectrometry with electrospray ionization. The temporal time trend of serum PFAAs in Nuuk Inuit during 1998–2005 and the correlation between serum PFAAs and legacy persistent organic pollutants (POPs) were explored. Results Serum PFAA levels were higher in Nuuk Inuit than in non-Nuuk Inuit. Within the same district, higher PFAA levels were observed for males. An age-dependent, increasing trend of serum PFAA levels in the period from 1998–2005 was observed for Nuuk Inuit. For the pooled gender data, no significant association between PFAAs and legacy POPs was observed for Nuuk Inuit while for non-Nuuk Inuit this correlation was significant. No correlation between PFAAs and legacy POPs was found for male Inuit, whereas significant correlation was observed both for pooled female Inuit and for non-Nuuk Inuit females. Conclusions We suggest that sources other than seafood intake might contribute to the observed higher PFAA levels in Nuuk Inuit compared to the pooled non-Nuuk Inuit.1 PMID:22456049

Long, Manhai; Bossi, Rossana; Bonefeld-Jørgensen, Eva C.

2012-01-01

37

Polyfluoroalkyl Chemicals in the Serum and Milk of Breastfeeding Women.  

EPA Science Inventory

Polyfluoroalkyl chemicals (PFCs) comprise a group of man-made organic compounds, some of which are persistent contaminants with developmental toxicity shown in laboratory animals. There is a paucity of human perinatal exposure data. The US EPA conducted a pilot study (Methods Adv...

38

Perfluoroalkyl compounds (PFCs) in wildlife from an urban estuary.  

PubMed

Previous research has documented the bioaccumulation of perfluoroalkyl compounds (PFCs) in apex predators in remote locations but few studies have evaluated urban estuaries. To assess the importance of PFCs in San Francisco Bay, two apex predators in the San Francisco Bay, double-crested cormorants (Phalacrocorax auritus) and Pacific harbor seals (Phoca vitulina richardii), were sampled. Prey fish (Atherinops affinis and Menidia audens) were also evaluated to better understand potential sources of PFCs to the foodweb. Perfluorooctane sulfonate (PFOS) was the primary PFC detected in cormorant eggs, small fish and harbor seal serum. PFOS detected in San Francisco Bay seal serum was typically an order of magnitude higher than those at the reference site. PFOS concentrations were highest in seals and cormorant eggs from the highly urbanized southern portion of the Bay. PFOS in eggs from the southern part of the Bay remained relatively constant between 2006 and 2009 despite the phase-out of perfluorosulfonyl-based compounds nationally. In addition, these levels exceed the avian predicted no effects concentration of 1.0 ?g mL(-1). Concentrations of the remaining PFCs measured were substantially lower than those of PFOS. PMID:22134832

Sedlak, Margaret D; Greig, Denise J

2012-01-01

39

Mechanism of Perfluoroalkyl Halide Toxicity: Catalysis of Perfluoroalkylation by Reduced Forms of Cobalamin (Vitamin B 12 )  

Microsoft Academic Search

Perfluoroalkyl halides (PFHs) are synthetic products widely used in various fields. Perfluorooctyl bromide (PFB) is used in medicine as a component of blood substitutes and for artificial lung ventilation. In both cases, it is considered a completely inert compound acting as a solvent for oxygen. However, there are many reports of PFH-induced intoxication, including lethal cases. Mechanisms underlying toxic effects

N. V. Beda; A. A. Nedospasov

2003-01-01

40

Perfluoroalkyl acids: recent research highlights  

EPA Science Inventory

Perfluorinated compounds are organic chemicals in which all hydrogen molecules of the carbon-chain are substituted by fluorine molecules. Generally, there are two types of perfluorinated compounds, the perfluoroalkanes that are primarily used clinically for oxygenation and respir...

41

Developmental Toxicity of Perfluoroalkyl Acid Mixtures in CD-1 Mice  

EPA Science Inventory

Perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS) and perfluorononanoic acid (PFNA) belong to a family of fluoro-organic compounds known as perfluoroalkyl acids (PFAAs). PFAAs have been widely used in industrial and commercial applications, and have been found to be...

42

Polymerizable disilanols having in-chain perfluoroalkyl groups  

NASA Technical Reports Server (NTRS)

Disilanols containing in-chain perfluoroalkyl and aromatic groups and the process by which they were prepared are discussed. The disilanols, when reacted with a diaminosilane and cured, produce polymeric material resistant to hydrocarbon fuels and stable at elevated temperatures.

Patterson, W. J.; Morris, D. E. (inventors)

1973-01-01

43

Mass Balance of Perfluoroalkyl Acids in the Baltic Sea  

PubMed Central

A mass balance was assembled for perfluorohexanoic acid (PFHxA), perfluorooctanoic acid (PFOA), perfluorodecanoic acid (PFDA), and perfluorooctanesulfonic acid (PFOS) in the Baltic Sea. Inputs (from riverine discharge, atmospheric deposition, coastal wastewater discharges, and the North Sea) and outputs (to sediment burial, transformation of the chemical, and the North Sea), as well as the inventory in the Baltic Sea, were estimated from recently published monitoring data. Formation of the chemicals in the water column from precursors was not considered. River inflow and atmospheric deposition were the dominant inputs, while wastewater treatment plant (WWTP) effluents made a minor contribution (<5%). A mass balance of the Oder River watershed was assembled to explore the sources of the perfluoroalkyl acids (PFAAs) in the river inflow. It indicated that WWTP effluents made only a moderate contribution to riverine discharge (21% for PFOA, 6% for PFOS), while atmospheric deposition to the watershed was 1–2 orders of magnitude greater than WWTP discharges. The input to the Baltic Sea exceeded the output for all four PFAAs, suggesting that inputs were higher during 2005–2010 than during the previous 20 years despite efforts to reduce emissions of PFAAs. One possible explanation is the retention and delayed release of PFAAs from atmospheric deposition in the soils and groundwater of the watershed. PMID:23528236

2013-01-01

44

Mass balance of perfluoroalkyl acids in the Baltic Sea.  

PubMed

A mass balance was assembled for perfluorohexanoic acid (PFHxA), perfluorooctanoic acid (PFOA), perfluorodecanoic acid (PFDA), and perfluorooctanesulfonic acid (PFOS) in the Baltic Sea. Inputs (from riverine discharge, atmospheric deposition, coastal wastewater discharges, and the North Sea) and outputs (to sediment burial, transformation of the chemical, and the North Sea), as well as the inventory in the Baltic Sea, were estimated from recently published monitoring data. Formation of the chemicals in the water column from precursors was not considered. River inflow and atmospheric deposition were the dominant inputs, while wastewater treatment plant (WWTP) effluents made a minor contribution (<5%). A mass balance of the Oder River watershed was assembled to explore the sources of the perfluoroalkyl acids (PFAAs) in the river inflow. It indicated that WWTP effluents made only a moderate contribution to riverine discharge (21% for PFOA, 6% for PFOS), while atmospheric deposition to the watershed was 1-2 orders of magnitude greater than WWTP discharges. The input to the Baltic Sea exceeded the output for all four PFAAs, suggesting that inputs were higher during 2005-2010 than during the previous 20 years despite efforts to reduce emissions of PFAAs. One possible explanation is the retention and delayed release of PFAAs from atmospheric deposition in the soils and groundwater of the watershed. PMID:23528236

Filipovic, Marko; Berger, Urs; McLachlan, Michael S

2013-05-01

45

Determination of polyfluoroalkyl phosphoric acid diesters, perfluoroalkyl phosphonic acids, perfluoroalkyl phosphinic acids, perfluoroalkyl carboxylic acids, and perfluoroalkane sulfonic acids in lake trout from the Great Lakes region.  

PubMed

A comprehensive method to extract perfluoroalkyl carboxylic acids, perfluoroalkane sulfonic acids, perfluoroalkyl phosphonic acids, perfluoroalkyl phosphinic acids, and polyfluoroalkyl phosphoric acid diesters simultaneously from fish samples has been developed. The recoveries of target compounds ranged from 78 % to 121 %. The new method was used to analyze lake trout (Salvelinus namaycush) from the Great Lakes region. The results showed that the total perfluoroalkane sulfonate concentrations ranged from 0.1 to 145 ng/g (wet weight) with perfluorooctane sulfonate (PFOS) as the dominant contaminant. Concentrations in fish between lakes were in the order of Lakes Ontario ? Erie > Huron > Superior ? Nipigon. The total perfluoroalkyl carboxylic acid concentrations ranged from 0.2 to 18.2 ng/g wet weight. The aggregate mean perfluorooctanoic acid (PFOA) concentration in fish across all lakes was 0.045 ± 0.023 ng/g. Mean concentrations of PFOA were not significantly different (p > 0.1) among the five lakes. Perfluoroalkyl phosphinic acids were detected in lake trout from Lake Ontario, Lake Erie, and Lake Huron with concentration ranging from non-detect (ND) to 0.032 ng/g. Polyfluoroalkyl phosphoric acid diesters were detected only in lake trout from Lake Huron, at levels similar to perfluorooctanoic acid. PMID:22722738

Guo, Rui; Reiner, Eric J; Bhavsar, Satyendra P; Helm, Paul A; Mabury, Scott A; Braekevelt, Eric; Tittlemier, Sheryl A

2012-11-01

46

Effect of pregnancy on the levels of selected perfluoroalkyl compounds for females aged 17-39 years: data from National Health and Nutrition Examination Survey 2003-2008.  

PubMed

The presence of perfluoroalkyl chemicals (PFC) in maternal serum may pose a risk to the developing fetus. A large-scale study to evaluate the extent of exposure to PFC in pregnant and nonpregnant females in the United States has not been conducted. The impact of pregnancy on the concentration levels of perfluorohexane sulfonic acid (PFHxS), perfluorononanoic acid (PFNA), perfluorooctanoate (PFOA), and perfluorooctane sulfonate (PFOS) was assessed by analyzing data (n?=?1079) from National Health and Nutrition Examination Survey (NHANES) for the years 2003-2008 for females aged 17-39 yr. While pregnant females possessed lower serum concentrations of all 4 PFC than nonpregnant females, only the differences for PFOS were significant (9.6 vs. 11.8 ng/ml). Those mothers who breast-fed at least one child displayed significantly lower levels of PFOA (2.6 vs. 3.1 ng/ml) than those with non-breast-fed infants. The concentration levels of PFNA and PFOA decreased with increase in number of live births. While levels of PFHxS and PFOS markedly fell over the period 2003-2008, the levels of PFNA rose over the same time period. There was nonlinear elevation in levels of PFHxS and PFOS with age. Smoking was associated with increased levels of PFNA and PFOA. There was a significant, positive association between total cholesterol and PFOS as well as for serum albumin with PFHxS and PFOS. Elevated levels of PFNA and PFOA were associated with a rise in serum protein. Further studies are needed to adequately explain why smoking was associated with increased levels of PFNA and PFOA. PMID:23611181

Jain, Ram B

2013-01-01

47

Development of a chemically defined serum-free medium for differentiation of rat adipose precursor cells  

SciTech Connect

Stromal-vascular cells from the epididymal fat pad of 4-week-old rats, when cultured in a medium containing insulin or insulin-like growth factor, IFG-I, triiodothyronine and transferrin, were able to undergo adipose conversion. Over ninety percent of the cells accumulated lipid droplets and this proportion was reduced in serum-supplemented medium. The adipose conversion was assessed by the development of lipoprotein lipase (LPL) and glycerol-3-phosphate dehydrogenase (GPDH) activities, (/sup 14/)glucose incorporation into polar and neutral lipids, triacylglycerol accumulation and lipolysis in response to isoproterenol. Similar results were obtained with stromal-vascular cells from rat subcutaneous and retroperitoneal adipose tissues. Stromal-vascular cells required no adipogenic factors in addition to the components of the serum-free medium. Insulin was required within a physiological range of concentrations for the emergence of LPL and at higher concentrations for that of GPDH. When present at concentrations ranging from 2 to 50 nM, IGF-I was able to replace insulin for the expression of both LPL and and GPDH. The development of a serum free, chemically defined medium for the differentiation of diploid adiopose precursor cells opens up the possibility of characterizing inhibitors or activators of the adipose conversion process.

Deslex, S.; Negrel, R.; Ailhaud, G.

1987-01-01

48

Thermal oxidative degradation reactions of linear perfluoroalkyl ethers  

NASA Technical Reports Server (NTRS)

Thermal and thermal oxidative stability studies were performed on linear perfluoroalkyl ether fluids. The effect on degradation by metal catalysts and degradation inhibitors is reported. The linear perfluoroalkyl ethers are inherently unstable at 316 C in an oxidizing atmosphere. The metal catalysts greatly increased the rate of degradation in oxidizing atmospheres. In the presence of these metals in an oxidizing atmosphere, the degradation inhibitors were highly effective in arresting degradation at 288 C. However, the inhibitors had only limited effectiveness at 316 C. The metals promote degradation by chain scission. Based on elemental analysis and oxygen consumption data, the linear perfluoroalkyl ether fluids have a structural arrangement based on difluoroformyl and tetrafluoroethylene oxide units, with the former predominating. Previously announced in STAR as N82-26468

Jones, W. R., Jr.; Paclorek, K. J. L.; Ito, T. I.; Kratzer, R. H.

1983-01-01

49

Rat bovine serum albumin (BSA) nephritis. VI. The influence of chemically altered antigen.  

PubMed Central

Bovine serum albumin (BSA) used to incite chronic serum sickness glomerulonephritis in rats was chemically modified to study the effect of antigenic alteration. The BSA was used in its native form (n-BSA) as well as anionic (a-BSA), cationic (c-BSA) or glycosylated (g-BSA) forms. Spontaneously hypertensive rats (SHR) preimmunized 8 weeks earlier received daily intravenous injections of the respective BSA preparations for the ensuing 3 weeks. Histological examination of their kidneys revealed that c-BSA given for 2 weeks induced a severe diffuse proliferative glomerulonephritis and profound proteinuria. Electron-dense deposits localized preferentially in the subepithelial spaces of renal glomeruli from these rats, but a few in the mesangia. Quite differently, rats receiving n-BSA or g-BSA developed a less severe form of glomerulonephritis even after 3 weeks of injections. Besides the massive mesangial deposits, the subepithelial deposits were conspicuous in the glomeruli from rats given g-BSA for 2 weeks, but deposition in glomerular capillaries was rare in rats given n-BSA for the same duration. In contrast, the administration of a-BSA resulted in minimal abnormalities visible by light microscopy and a few immune deposits in the mesangia even at the third week. The antibody response in rats given c-BSA or a-BSA was apparently different from n-BSA treated rats. The present study shows the important role of the antigen's electric charge in the pathogenesis of proliferative glomerulonephritis. The foregoing results also foster our proposal that the carbohydrate content of the antigen influences the development of this renal disease. Images Fig. 2 PMID:3539427

Yamamoto, T; Miyazaki, S; Kawasaki, K; Yaoita, E; Kihara, I

1986-01-01

50

Parameters affecting the formation of perfluoroalkyl acids during wastewater treatment.  

PubMed

This study examined the fate and behaviour of perfluoroalkyl acids (PFAAs) in liquid and solid samples from five different wastewater treatment types: facultative and aerated lagoons, chemically assisted primary treatment, secondary aerobic biological treatment, and advanced biological nutrient removal treatment. To the best of our knowledge, this is the largest data set from a single study available in the literature to date for PFAAs monitoring study in wastewater treatment. Perfluorooctanoic acid (PFOA) was the predominant PFAA in wastewater with levels from 2.2 to 150ng/L (influent) and 1.9 to 140ng/L (effluent). Perfluorooctanesulfonic acid (PFOS) was the predominant compound in primary sludge, waste biological sludge, and treated biosolids with concentrations from 6.4 to 2900ng/g dry weight (dw), 9.7 to 8200ng/gdw, and 2.1 to 17,000ng/gdw, respectively. PFAAs were formed during wastewater treatment and it was dependant on both process temperature and treatment type; with higher rates of formation in biological wastewater treatment plants (WWTPs) operating at longer hydraulic retention times and higher temperatures. PFAA removal by sorption was influenced by different sorption tendencies; median log values of the solid-liquid distribution coefficient estimated from wastewater biological sludge and final effluent were: PFOS (3.73)>PFDA (3.68)>PFNA (3.25)>PFOA (2.49)>PFHxA (1.93). Mass balances confirmed the formation of PFAAs, low PFAA removal by sorption, and high PFAA levels in effluents. PMID:24691135

Guerra, P; Kim, M; Kinsman, L; Ng, T; Alaee, M; Smyth, S A

2014-05-15

51

Perfluoroalkyl Acids: A Review of Monitoring and Toxicological Findings  

Microsoft Academic Search

In recent years, human and wildlife monitoring studies have identified perfluoroalkyl acids (PFAA) worldwide. This has led to efforts to better understand the hazards that may be inherent in these compounds, as well as the global distribution of the PFAAs. Much attention has focused on understanding the toxicology of the two most widely known PFAAs, perfluorooctanoic acid, and perfluorooctane sulfate.

Christopher Lau; Katherine Anitole; Colette Hodes; David Lai; Andrea Pfahles-Hutchens; Jennifer Seed

2007-01-01

52

Environmental-Fate Patterns for Perfluoroalkylates and their Precursors  

EPA Science Inventory

Two sites with elevated concentrations of perfluoroalkylates (PFAs) and fluorotelomer alcohols (FTOHs) were studied: 1) agricultural fields near Decatur, AL on which sewage sludge had been applied; and 2) the Conasauga River system near Dalton, GA where treated sewage effluent is...

53

Perfluoroalkyl Contaminants in an Arctic Marine Food Web: Trophic  

E-print Network

Perfluoroalkyl Contaminants in an Arctic Marine Food Web: Trophic Magnification and Wildlife significantly (P magnification factors (TMFs) of organochlorines ranged ),exceedstheoralreferencedoseforPFOS (7.5 � 10-5 mg·kg bw-1 ·d-1 ), which raises concern for potential biological effects

Gobas, Frank

54

Capturing Labile Sulfenamide and Sulfinamide Serum Albumin Adducts of Carcinogenic Arylamines by Chemical Oxidation  

PubMed Central

Aromatic amines and heterocyclic aromatic amines (HAAs) are a class of structurally related carcinogens that are formed during the combustion of tobacco or during the high temperature cooking of meats. These procarcinogens undergo metabolic activation by N-oxidation of the exocyclic amine group to produce N-hydroxylated metabolites, which are critical intermediates implicated in toxicity and DNA damage. The arylhydroxylamines and their oxidized arylnitroso derivatives can also react with cysteine (Cys) residues of glutathione or proteins to form, respectively, sulfenamide and sulfinamide adducts. However, sulfur-nitrogen linked adducted proteins are often difficult to detect because they are unstable and undergo hydrolysis during proteolytic digestion. Synthetic N-oxidized intermediates of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), a carcinogenic HAA produced in cooked meats, and 4-aminobiphenyl, a carcinogenic aromatic amine present in tobacco smoke were reacted with human serum albumin (SA) and formed labile sulfenamide or sulfinamide adducts at the Cys34 residue. Oxidation of the carcinogen-modified SA with m-chloroperoxybenzoic acid (m-CPBA) produced the arylsulfonamide adducts, which were stable to heat and the chemical reduction conditions employed to denature SA. The sulfonamide adducts of PhIP and 4-ABP were identified, by liquid chromatography/mass spectrometry, in proteolytic digests of denatured SA. Thus, selective oxidation of arylamine-modified SA produces stable arylsulfonamide-SA adducts, which may serve as biomarkers of these tobacco and dietary carcinogens. PMID:23240913

Peng, Lijuan; Turesky, Robert J.

2013-01-01

55

Rapid trifluoromethylation and perfluoroalkylation of five-membered heterocycles by photoredox catalysis in continuous flow.  

PubMed

Trifluoromethylated and perfluoroalkylated heterocycles are important building blocks for the synthesis of numerous pharmaceutical products, agrochemicals and are widely applied in material sciences. To date, trifluoromethylated and perfluoroalkylated hetero-aromatic systems can be prepared utilizing visible light photoredox catalysis methodologies in batch. While several limitations are associated with these batch protocols, the application of microflow technology could greatly enhance and intensify these reactions. A simple and straightforward photocatalytic trifluoromethylation and perfluoroalkylation method has been developed in continuous microflow, using commercially available photocatalysts and microflow components. A selection of five-membered hetero-aromatics were successfully trifluoromethylated (12?examples) and perfluoroalkylated (5?examples) within several minutes (8-20?min). PMID:24706388

Straathof, Natan J W; Gemoets, Hannes P L; Wang, Xiao; Schouten, Jaap C; Hessel, Volker; Noël, Timothy

2014-06-01

56

Synthesis of the diazonium (perfluoroalkyl) benzenesulfonimide monomer from Nafion monomer for proton exchange membrane fuel cells  

NASA Astrophysics Data System (ADS)

One diazonium (perfluoroalkyl) benzenesulfonimide monomer, perfluoro-3, 6-dioxa-4-methyl-7-octene benzenesulfonyl imide, has been synthesized from Nafion monomer for the first time. With trifluorovinyl ether and diazonium precursors, the partially-fluorinated diazonium PFSI monomer can be polymerized and will provide chemically bonding with carbon electrode in proton exchange membrane fuel cells. A systematic study of the synthesis and characterization of this diazonium PFSI monomer has been conducted by varying reaction conditions. The optimized synthesis method has been established in the lab.

Mei, Hua; D'Andrea, Dan; Nguyen, Tuyet-Trinh; Nworie, Chima

2014-02-01

57

Migration of perfluoroalkyl acids from food packaging to food simulants.  

PubMed

A broad range of fluorochemicals is used to impart oil and water barrier properties to paper and paperboard food packaging. Many of the fluorochemicals are applied to paper and paperboard as complex mixtures containing reaction products and by-products and unreacted starting materials. This work primarily focussed on the determination of seven perfluorocarboxylic acids (PFCAs) in two commercially available food contact papers: a di-perfluoro-alkyloxy-amino-acid and a perfluoroalkyl phosphate surfactant. In addition, the migration of the PFCAs into five food simulants from two commercial packages was evaluated. All seven PFCAs were detected in the range of 700-2220 µg kg?¹ of paper, while three perfluoroalkyl sulphonates were under the LOD. Results from migration tests showed that migration depends on paper characteristics, time and food simulant. The percentage of migration after 10 days at 40°C ranged from 4.8% to 100% for the two papers and different food simulants. PMID:23701306

Xu, Y; Noonan, G O; Begley, T H

2013-01-01

58

Synthesis of new axially dissymmetric ligand with large perfluoroalkyl groups  

Microsoft Academic Search

A new axially dissymmetric ligand with large perfluoroalkyl groups, 2,2?-bis(1-hydroxy-1H-perfluorooctyl)biphenyl (1c), which could not be obtained by the coupling reaction of the aryl bromide using copper powder, was synthesized successfully by the coupling reaction using Ni(COD)2. This ligand showed much higher asymmetric induction in the reaction of diethylzinc with benzaldehyde than the trifluoromethyl (1a) or pentafluoroethyl (1b) analogues.

Masaaki Omote; Yuji Nishimura; Kazuyuki Sato; Akira Ando; Itsumaro Kumadaki

2005-01-01

59

Perfluoroalkylated substances in the global tropical and subtropical surface oceans.  

PubMed

In this study, perfluoroalkylated substances (PFASs) were analyzed in 92 surface seawater samples taken during the Malaspina 2010 expedition which covered all the tropical and subtropical Atlantic, Pacific and Indian oceans. Nine ionic PFASs including C6-C10 perfluoroalkyl carboxylic acids (PFCAs), C4 and C6-C8 perfluoroalkyl sulfonic acids (PFSAs) and two neutral precursors perfluoroalkyl sulfonamides (PFASAs), were identified and quantified. The Atlantic Ocean presented the broader range in concentrations of total PFASs (131-10900 pg/L, median 645 pg/L, n = 45) compared to the other oceanic basins, probably due to a better spatial coverage. Total concentrations in the Pacific ranged from 344 to 2500 pg/L (median = 527 pg/L, n = 27) and in the Indian Ocean from 176 to 1976 pg/L (median = 329, n = 18). Perfluorooctanesulfonic acid (PFOS) was the most abundant compound, accounting for 33% of the total PFASs globally, followed by perfluorodecanoic acid (PFDA, 22%) and perfluorohexanoic acid (PFHxA, 12%), being the rest of the individual congeners under 10% of total PFASs, even for perfluorooctane carboxylic acid (PFOA, 6%). PFASAs accounted for less than 1% of the total PFASs concentration. This study reports the ubiquitous occurrence of PFCAs, PFSAs, and PFASAs in the global ocean, being the first attempt, to our knowledge, to show a comprehensive assessment in surface water samples collected in a single oceanic expedition covering tropical and subtropical oceans. The potential factors affecting their distribution patterns were assessed including the distance to coastal regions, oceanic subtropical gyres, currents and biogeochemical processes. Field evidence of biogeochemical controls on the occurrence of PFASs was tentatively assessed considering environmental variables (solar radiation, temperature, chlorophyll a concentrations among others), and these showed significant correlations with some PFASs, but explaining small to moderate percentages of variability. This suggests that a number of physical and biogeochemical processes collectively drive the oceanic occurrence and fate of PFASs in a complex manner. PMID:25325411

González-Gaya, Belén; Dachs, Jordi; Roscales, Jose L; Caballero, Gemma; Jiménez, Begoña

2014-11-18

60

Polyfluoroalkyl chemicals in pooled blood serum from infants, children, and adults in Australia.  

PubMed

Polyfluoroalkyl chemicals (PFCs) have been used worldwide for more than 50 years in a wide variety of industrial and consumer products. Limited data exist on human exposure to PFCs in the Southern Hemisphere. Human blood serum collected in southeast Queensland, Australia, in 2006-2007 from 2420 donors was pooled according to age (cord blood, 0-0.5, 0.6-1, 1.1-1.5, 1.6-2, 2.1-2.5, 2.6-3, 3.1-3.5, 3.6-4, 4.1-6, 6.1-9, 9.1-12, 12.1-15, 16-30, 31-45, 46-60, and > 60 years) and gender and was analyzed for eight PFCs. Across all pools, perfluorooctane sulfonate (PFOS) was detected at the highest mean concentration (15.2 ng/mL) followed by perfluorooctanoate (PFOA, 6.4 ng/mL), perfluorohexane sulfonate (PFHxS, 3.1 ng/mL), perfluorononanoate (PFNA, 0.8 ng/mL), 2-(N-methylperfluorooctance sulfonamide) acetate (Me-PFOSA-AcOH, 0.66 ng/mL), and perfluorodecanoate (PFDeA, 0.29 ng/mL). Perfluorooctane sulfonamide was detected in only 24% of the pools, and 2-(N-ethylperfluorooctane sulfonamide) acetate was detected in only one. PFOS concentrations were significantly higher in pools from adult males than from adult females (p = 0.002); no gender differences were apparent in the pools from children (< 12 years old). The highest mean concentrations of PFOA, PFHxS, PFNA, PFDeA, and Me-PFOSA-AcOH were found in children < 15 years, while PFOS was highest in adults > 60 years. Investigation into the sources and exposure pathways in Australia, in particular for children, is necessary as well as continued biomonitoring to determine the potential effects on human concentrations as a result of changes in the PFC manufacturing practices, including the cessation of production of several PFCs. PMID:19569351

Toms, Leisa-Maree L; Calafat, Antonia M; Kato, Kayoko; Thompson, Jack; Harden, Fiona; Hobson, Peter; Sjödin, Andreas; Mueller, Jochen F

2009-06-01

61

Development of a chemically defined serum-free medium for differentiation of rat adipose precursor cells  

Microsoft Academic Search

Stromal-vascular cells from the epididymal fat pad of 4-week-old rats, when cultured in a medium containing insulin or insulin-like growth factor, IFG-I, triiodothyronine and transferrin, were able to undergo adipose conversion. Over ninety percent of the cells accumulated lipid droplets and this proportion was reduced in serum-supplemented medium. The adipose conversion was assessed by the development of lipoprotein lipase (LPL)

S. Deslex; R. Negrel; G. Ailhaud

1987-01-01

62

Chemical and cytokine features of innate immunity characterize serum and tissue profiles in inflammatory bowel disease.  

PubMed

Inflammatory bowel disease (IBD) arises from inappropriate activation of the mucosal immune system resulting in a state of chronic inflammation with causal links to colon cancer. Helicobacter hepaticus-infected Rag2(-/-) mice emulate many aspects of human IBD, and our recent work using this experimental model highlights the importance of neutrophils in the pathology of colitis. To define molecular mechanisms linking colitis to the identity of disease biomarkers, we performed a translational comparison of protein expression and protein damage products in tissues of mice and human IBD patients. Analysis in inflamed mouse colons identified the neutrophil- and macrophage-derived damage products 3-chlorotyrosine (Cl-Tyr) and 3-nitrotyrosine, both of which increased with disease duration. Analysis also revealed higher Cl-Tyr levels in colon relative to serum in patients with ulcerative colitis and Crohn disease. The DNA chlorination damage product, 5-chloro-2'-deoxycytidine, was quantified in diseased human colon samples and found to be present at levels similar to those in inflamed mouse colons. Multivariate analysis of these markers, together with serum proteins and cytokines, revealed a general signature of activated innate immunity in human IBD. Signatures in ulcerative colitis sera were strongly suggestive of neutrophil activity, and those in Crohn disease and mouse sera were suggestive of both macrophage and neutrophil activity. These data point to innate immunity as a major determinant of serum and tissue profiles and provide insight into IBD disease processes. PMID:23754421

Knutson, Charles G; Mangerich, Aswin; Zeng, Yu; Raczynski, Arkadiusz R; Liberman, Rosa G; Kang, Pilsoo; Ye, Wenjie; Prestwich, Erin G; Lu, Kun; Wishnok, John S; Korzenik, Joshua R; Wogan, Gerald N; Fox, James G; Dedon, Peter C; Tannenbaum, Steven R

2013-06-25

63

Chemical and cytokine features of innate immunity characterize serum and tissue profiles in inflammatory bowel disease  

PubMed Central

Inflammatory bowel disease (IBD) arises from inappropriate activation of the mucosal immune system resulting in a state of chronic inflammation with causal links to colon cancer. Helicobacter hepaticus-infected Rag2?/? mice emulate many aspects of human IBD, and our recent work using this experimental model highlights the importance of neutrophils in the pathology of colitis. To define molecular mechanisms linking colitis to the identity of disease biomarkers, we performed a translational comparison of protein expression and protein damage products in tissues of mice and human IBD patients. Analysis in inflamed mouse colons identified the neutrophil- and macrophage-derived damage products 3-chlorotyrosine (Cl-Tyr) and 3-nitrotyrosine, both of which increased with disease duration. Analysis also revealed higher Cl-Tyr levels in colon relative to serum in patients with ulcerative colitis and Crohn disease. The DNA chlorination damage product, 5-chloro-2?-deoxycytidine, was quantified in diseased human colon samples and found to be present at levels similar to those in inflamed mouse colons. Multivariate analysis of these markers, together with serum proteins and cytokines, revealed a general signature of activated innate immunity in human IBD. Signatures in ulcerative colitis sera were strongly suggestive of neutrophil activity, and those in Crohn disease and mouse sera were suggestive of both macrophage and neutrophil activity. These data point to innate immunity as a major determinant of serum and tissue profiles and provide insight into IBD disease processes. PMID:23754421

Knutson, Charles G.; Mangerich, Aswin; Zeng, Yu; Raczynski, Arkadiusz R.; Liberman, Rosa G.; Kang, Pilsoo; Ye, Wenjie; Prestwich, Erin G.; Lu, Kun; Wishnok, John S.; Korzenik, Joshua R.; Wogan, Gerald N.; Fox, James G.; Dedon, Peter C.; Tannenbaum, Steven R.

2013-01-01

64

Chemically defined serum-free and xeno-free media for multiple cell lineages  

PubMed Central

Cell culture is one of the most common methods used to recapitulate a human disease environment in a laboratory setting. Cell culture techniques are used to grow and maintain cells of various types including those derived from primary tissues, such as stem cells and cancer tumors. However, a major confounding factor with cell culture is the use of serum and animal (xeno) products in the media. The addition of animal products introduces batch and lot variations that lead to experimental variability, confounds studies with therapeutic outcomes for cultured cells, and represents a major cost associated with cell culture. Here we report a commercially available serum-free, albumin-free, and xeno free (XF) media (Neuro-PureTM) that is more cost-effective than other commercial medias. Neuro-Pure was used to maintain and differentiate various cells of neuronal lineages, fibroblasts, as well as specific cancer cell lines; without the use of contaminants such serum, albumin, and animal products. Neuro-Pure allows for a controlled and reproducible cell culture environment that is applicable to translational medicine and general tissue culture.

Usta, Sumeyra Naz; Scharer, Christopher D.; Xu, Jie; Frey, Teryl K.

2014-01-01

65

Quantification of pharmaceuticals, personal care products, and perfluoroalkyl substances in the marine sediments of Puget Sound, Washington, USA.  

PubMed

Concentrations of 119 pharmaceuticals and personal care products (PPCPs) and 13 perfluoroalkyl substances (PFASs) in marine sediments measured throughout Puget Sound (n?=?10) and Bellingham Bay (n?=?30), Washington, USA, are reported. These data are among the first measurements of PPCPs and PFASs in marine sediments from the Pacific Northwest and provide a comparison to previous measurements of these chemicals in influent, effluent, and biosolids from municipal wastewater treatment plants throughout the region. The concentrations of both PPCPs and PFASs in sediments from Puget Sound and Bellingham Bay ranged from very low to non-detectable for most compounds. Only 14 of the 119 PPCPs and 3 of 13 PFASs were quantifiable in sediments. Diphenhydramine (an antihistamine) was most frequently detected (87.5% of samples), with a maximum concentration of 4.81?ng/g dry weight and an estimated mean detected concentration of 1.68?ng/g. Triclocarban (an antibacterial) was detected in 35.0% of the samples, with a maximum concentration of 16.6?ng/g dry weight. Perfluoroalkyl substances were detected in 2.5% of analyses. Perfluorobutanoate, perfluorooctane sulfonate, and perfluorooctane sulfonamide were detected in 7, 5, and 1 sample(s) each, respectively, with the highest concentrations observed for perfluorooctane sulfonate (1.5?ng/g). Detected concentrations were often highest within the industrial harbor in Bellingham Bay and near the cities of Seattle and Bremerton. Environ Toxicol Chem 2013;32:1701-1710. © 2013 SETAC. PMID:23843318

Long, Edward R; Dutch, Margaret; Weakland, Sandra; Chandramouli, Bharat; Benskin, Jonathan P

2013-08-01

66

Evidence of remediation-induced alteration of subsurface poly- and perfluoroalkyl substance distribution at a former firefighter training area.  

PubMed

Poly- and perfluoroalkyl substances (PFASs) are a class of fluorinated chemicals that are utilized in firefighting and have been reported in groundwater and soil at several firefighter training areas. In this study, soil and groundwater samples were collected from across a former firefighter training area to examine the extent to which remedial activities have altered the composition and spatial distribution of PFASs in the subsurface. Log Koc values for perfluoroalkyl acids (PFAAs), estimated from analysis of paired samples of groundwater and aquifer solids, indicated that solid/water partitioning was not entirely consistent with predictions based on laboratory studies. Differential PFAA transport was not strongly evident in the subsurface, likely due to remediation-induced conditions. When compared to the surface soil spatial distributions, the relative concentrations of perfluorooctanesulfonate (PFOS) and PFAA precursors in groundwater strongly suggest that remedial activities altered the subsurface PFAS distribution, presumably through significant pumping of groundwater and transformation of precursors to PFAAs. Additional evidence for transformation of PFAA precursors during remediation included elevated ratios of perfluorohexanesulfonate (PFHxS) to PFOS in groundwater near oxygen sparging wells. PMID:24866261

McGuire, Meghan E; Schaefer, Charles; Richards, Trenton; Backe, Will J; Field, Jennifer A; Houtz, Erika; Sedlak, David L; Guelfo, Jennifer L; Wunsch, Assaf; Higgins, Christopher P

2014-06-17

67

Bioaccumulation and uptake routes of perfluoroalkyl acids in Daphnia magna.  

PubMed

Perfluoroalkyl acids (PFAs), one kind of emerging contaminants, have attracted great attentions in recent years. However, the study about their bioaccumulation mechanism remains scarce. In this research, the bioaccumulation of six kinds of PFAs in water flea Daphnia magna was studied. The uptake rates of PFAs in D. magna ranged from 178 to 1338 L kg(-1) d(-1), and they increased with increasing perfluoroalkyl chain length; the elimination rates ranged from 0.98 to 2.82 d(-1). The bioaccumulation factors (BAFs) of PFAs ranged from 91 to 380 L kg(-1) in wet weight after 25 d exposure; they increased with increasing perfluoroalkyl chain length and had a significant positive correlation with the n-octanol/water partition coefficients (logK(ow)) of PFAs (p<0.05). This indicated that the hydrophobicity of PFAs plays an important role in their bioaccumulation. The BAFs almost kept constant when the PFA concentrations in aqueous phase increased from 1 to 10 ?g L(-1). Scenedesmus subspicatus, as the food of D. magna, did not significantly affect the bioaccumulation of PFAs by D. magna. Furthermore, the body burden of PFAs in the dead D. magna was 1.08-2.52 times higher than that in the living ones, inferring that the body surface sorption is a main uptake route of PFAs in D. magna. This study suggested that the bioaccumulation of PFAs in D. magna is mainly controlled by their partition between organisms and water; further research should be conducted to study the intrinsic mechanisms, especially the roles of protein and lipid in organisms. PMID:22967930

Dai, Zhineng; Xia, Xinghui; Guo, Jia; Jiang, Xiaoman

2013-02-01

68

Perfluoroalkyl acids in the Atlantic and Canadian Arctic Oceans.  

PubMed

We report here on the spatial distribution of C(4), C(6), and C(8) perfluoroalkyl sulfonates, C(6)-C(14) perfluoroalkyl carboxylates, and perfluorooctanesulfonamide in the Atlantic and Arctic Oceans, including previously unstudied coastal waters of North and South America, and the Canadian Arctic Archipelago. Perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) were typically the dominant perfluoroalkyl acids (PFAAs) in Atlantic water. In the midnorthwest Atlantic/Gulf Stream, sum PFAA concentrations (?PFAAs) were low (77-190 pg/L) but increased rapidly upon crossing into U.S. coastal water (up to 5800 pg/L near Rhode Island). ?PFAAs in the northeast Atlantic were highest north of the Canary Islands (280-980 pg/L) and decreased with latitude. In the South Atlantic, concentrations increased near Rio de la Plata (Argentina/Uruguay; 350-540 pg/L ?PFAAs), possibly attributable to insecticides containing N-ethyl perfluorooctanesulfonamide, or proximity to Montevideo and Buenos Aires. In all other southern hemisphere locations, ?PFAAs were <210 pg/L. PFOA/PFOS ratios were typically ?1 in the northern hemisphere, ?1 near the equator, and ?1 in the southern hemisphere. In the Canadian Arctic, ?PFAAs ranged from 40 to 250 pg/L, with perfluoroheptanoate, PFOA, and PFOS among the PFAAs detected at the highest concentrations. PFOA/PFOS ratios (typically ?1) decreased from Baffin Bay to the Amundsen Gulf, possibly attributable to increased atmospheric inputs. These data help validate global emissions models and contribute to understanding of long-range transport pathways and sources of PFAAs to remote regions. PMID:22548373

Benskin, Jonathan P; Muir, Derek C G; Scott, Brian F; Spencer, Christine; De Silva, Amila O; Kylin, Henrik; Martin, Jonathan W; Morris, Adam; Lohmann, Rainer; Tomy, Gregg; Rosenberg, Bruno; Taniyasu, Sachi; Yamashita, Nobuyoshi

2012-06-01

69

Exposure to perfluoroalkyl substances and sperm DNA global methylation in Arctic and European populations.  

PubMed

Perfluoroalkyl substances (PFASs) are widely used in a variety of industrial processes and products, and have been detected globally in humans and wildlife. PFASs are suspected to interfere with endocrine signaling and to adversely affect human reproductive health. The aim of the present study was to investigate the associations between exposure to PFASs and sperm global methylation levels in a population of non-occupationally exposed fertile men. Measurements of PFASs in serum from 262 partners of pregnant women from Greenland, Poland and Ukraine, were also carried out by liquid chromatography tandem mass spectrometry. Perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), and perfluorononanoic acid (PFNA) were detected in 97% of the blood samples. Two surrogate markers were used to assess DNA global methylation levels in semen samples from the same men: (a) average DNA methylation level in repetitive DNA sequences (Alu, LINE-1, Sat?) quantified by PCR-pyrosequencing after bisulfite conversion; (b) flow cytometric immunodetection of 5-methyl-cytosines. After multivariate linear regression analysis, no major consistent associations between PFASs exposure and sperm DNA global methylation endpoints could be detected. However, since weak but statistically significant associations of different PFASs with DNA hypo- and hyper-methylation were found in some of the studied populations, effects of PFASs on sperm epigenetic processes cannot be completely excluded, and this issue warrants further investigation. PMID:24889506

Leter, Giorgio; Consales, Claudia; Eleuteri, Patrizia; Uccelli, Raffaella; Specht, Ina O; Toft, Gunnar; Moccia, Tania; Budillon, Alfredo; Jönsson, Bo A G; Lindh, Christian H; Giwercman, Aleksander; Pedersen, Henning S; Ludwicki, Jan K; Zviezdai, Valentyna; Heederik, Dick; Bonde, Jens Peter E; Spanò, Marcello

2014-08-01

70

Testing for departures from additivity in mixtures of perfluoroalkyl acids (PFAAs)  

PubMed Central

This study is a follow-up to a paper by Carr et al. that determined a design structure to optimally test for departures from additivity in a fixed ratio mixture of four perfluoroalkyl acids (PFAAs) using an in vitro transiently-transfected COS-1 PPAR? reporter model with a mixing ratio that is based on average serum levels in NHANES subjects. Availability of information regarding potential for additivity of PFAAs in mixtures is critically important for risk assessors who are concerned with the ability of the compounds to affect human health and impact ecological systems. It is clear that exposures are not to single compounds, but to mixtures of the PFAAs. This paper presents the results from the data collected using the design from Carr et al. along with subsequent analyses that were performed to classify the relationships among mixtures of PFAAs. A non-linear logistic additivity model was employed to predict relative luciferase units (RLU), an indicator of PPAR? activation. The results indicated a less than additive relationship among the four PFAAs. To determine if the possible “antagonism” is from the competition among or between carboxylates and sulfonates, four different binary mixtures were also studied. There was a less than additive relationship in all four binary mixtures. These findings are generally similar to two other reports of interfering interactions between PFAAs in mixtures. The most conservative interpretation for our data would be an assumption of additivity (and lack of a greater than additive interaction), with a potential for antagonistic interactions. PMID:23470359

Carr, Caroline K.; Watkins, Andrew M.; Wolf, Cynthia J.; Abbott, Barbara D.; Lau, Christopher; Gennings, Chris

2013-01-01

71

Perfluoroalkyl substances (PFASs) in food and water from Faroe Islands.  

PubMed

Diet and drinking water are suggested to be major exposure pathways for perfluoroalkyl substances (PFASs). In this study, food items and water from Faroe Islands sampled in 2011/2012 were analyzed for 11 perfluoroalkyl carboxylic acids (PFCAs) and 4 perfluoroalkane sulfonic acids (PFSAs). The food samples included milk, yoghurt, crème fraiche, potatoes, fish, and fish feed, and the water samples included surface water and purified drinking water. In total, nine PFCAs and four PFSAs were detected. Generally, the levels of PFAS were in the lower picogram per gram range. Perfluorobutanoic acid was a major contributor to the total PFASs concentration in water samples and had a mean concentration of 750 pg/L. Perfluoroundecanoic acid (PFUnDA) was predominating in milk and wild fish with mean concentrations of 170 pg/g. Perfluorooctane sulfonic acid (PFOS) was most frequently detected in food items followed by PFUnDA, perfluorononanoic acid, and perfluorooctanoic acid (PFOA). Levels of PFUnDA and PFOA exceeded those of PFOS in milk and fish samples. Prevalence of long-chain PFCAs in Faroese food items and water is confirming earlier observations of their increase in Arctic biota. Predominance of short-chain and long-chain homologues indicates exposure from PFOS and PFOA replacement compounds. PMID:23589272

Eriksson, Ulrika; Kärrman, Anna; Rotander, Anna; Mikkelsen, Bjørg; Dam, Maria

2013-11-01

72

Circumpolar study of perfluoroalkyl contaminants in polar bears (Ursus maritimus).  

PubMed

Perfluoroalkyl substances were determined in liver tissues and blood of polar bears (Ursus maritimus) from five locations in the North American Arctic and two locations in the European Arctic. Concentrations of perfluorooctane sulfonate (PFOS), perfluorohexane sulfonate, heptadecafluorooctane sulfonamide, and perfluoroalkyl carboxylates with C(8)-C(15) perfluorinated carbon chains were determined using liquid chromatography tandem mass spectrometry. PFOS concentrations were significantly correlated with age at four of seven sampling locations, while gender was not correlated to concentration for any compound measured. Populations in South Hudson Bay (2000-2730 ng/g wet wt), East Greenland (911-2140 ng/g wet wt), and Svalbard (756-1290 ng/g wet wt) had significantly (P < 0.05) higher PFOS concentrations than western populations such as the Chukchi Sea (435-729 ng/g wet wt). Concentrations of perfluorocarboxylic acids (PFCAs) with adjacent chain lengths (i.e., C9:C10 and C10:C11) were significantly correlated (P < 0.05), suggesting PFCAs have a common source within a location, but there were differences in proportions of PFCAs between eastern and western location sources. Concentrations of PFOS in liver tissue at five locations were correlated with concentrations of four polychlorinated biphenyl congeners (180, 153, 138, and 99) in adipose tissue of bears in the same populations, suggesting similar transport pathways and source regions of PFOS or precursors. PMID:16124282

Smithwick, Marla; Mabury, Scott A; Solomon, Keith R; Sonne, Christian; Martin, Jonathan W; Born, Erik W; Dietz, Rune; Derocher, Andrew E; Letcher, Robert J; Evans, Thomas J; Gabrielsen, Geir W; Nagy, John; Stirling, Ian; Taylor, Mitch K; Muir, Derek C G

2005-08-01

73

SIMULTANEOUS DETERMINATION OF PERFLUOROALKYL CARBOXYLATES (PFCAs), SULFONATES (PFSAs) AND PHOSPHONATES (PFPAs) IN FOOD CAULDRONS  

E-print Network

SIMULTANEOUS DETERMINATION OF PERFLUOROALKYL CARBOXYLATES (PFCAs), SULFONATES (PFSAs) AND PHOSPHONATES (PFPAs) IN FOOD CAULDRONS Shahid Ullah, Robin Vestergren, Tomas Alsberg, Urs Berger Department intake was suggested to be one of the major routes of human exposure to perfluorooctanoate

74

Estrogenic Activity of Perfluoroalkyl Acids in Juvenile Rainbow Trout (Oncorhynchus Mykiss)  

EPA Science Inventory

The potential estrogenic activity of perfluoroalkyl acids (PFAAs) was determined using separate screening and dose response studies with juvenile rainbow trout (Oncorhynchus mykiss). Results of this study indicate that some PFAAs may act as estrogens in fish....

75

Mass Spectra of Some Perfluoroalkyl and Perfluoroalkylether Substituted 1,2,4-Oxadiazoles  

NASA Technical Reports Server (NTRS)

Electron impact fragmentation patterns were obtained for 1,4-bis[(5-perfluoro-n-heptyl)-1,2,4-oxadiazolyl- benzene, its perfluoroalkylether substituted analogue, 3,5-bis(perfluoroalkyl)-, 3,5-bis(perfluoroalkylether)- and 3-perfluoroalkylether-5-perfluoroalkyl-1,2,4-oxadiazoles. In the compounds containing the phenylene group the molecular ion constituted the base peak; the main process was the breakdown of the oxadiazole ring with concurrent liberation of the perfluoroalkyl or perfluoroalkylether nitrile molecule; cleavage of the fluorinated chain ot to the oxadiazole ring was found to take place to a considerable degree. In the perfluorinated 1,2,4-oxadiazoles cleavage beta to the oxadiazole ring occurred preferentially; fragmentation of the ring itself took place to a limited degree only. The 3-perfluoroalkylether-5-perfluoroalkyl-1,2,4-oxadiazole appeared to undergo the primary beta-cleavage exclusively at the perfluoroalkylether sidechain.

Paciorek, Kazimiera J. L.; Nakahara, James H.; Kratzer, Reinhold H.; Rosser, Robert W.

1977-01-01

76

Occurrence of brominated flame retardants and perfluoroalkyl substances in fish from the Czech aquatic ecosystem.  

PubMed

This study reports results of analysis of various groups of halogenated compounds, including brominated flame retardants (BFRs), such as polybrominated diphenylethers (PBDEs), hexabromocyclododecane (HBCD), tetrabromobisphenol A (TBBPA) and perfluoroalkyl substances (PFASs) in 48 fish samples collected in eight localities from the Czech Republic. In this survey, identification of potential sources of these chemicals was also performed; therefore several sampling sites located in highly industrialized areas were also selected. Perfluorooctanesulfonate (PFOS) was dominating in all tested fish samples. Generally, the content of ?BFRs was significantly lower, i.e. in the range of 0.21-19.9 ?g/kg wet weight, ww (median value 2.37 ?g/kg ww) compared to the concentration of ?PFASs that was in the range of 0.15-877 ?g/kg ww (median value 8.5 ?g/kg ww). The extremely high content of PFOS (842 ?g/kg ww) was found in fish muscle tissue from the locality situated on the Bílina River, where chemical industry is located. This concentration was comparable to those found in similar highly industrialized areas worldwide. PMID:23712119

Hloušková, Veronika; Lanková, Darina; Kalachová, Kamila; Hrádková, Petra; Poustka, Jan; Hajšlová, Jana; Pulkrabová, Jana

2013-09-01

77

Treatment of poly- and perfluoroalkyl substances in U.S. full-scale water treatment systems.  

PubMed

The near ubiquitous presence of poly- and perfluoroalkyl substances (PFASs) in humans has raised concerns about potential human health effects from these chemicals, some of which are both extremely persistent and bioaccumulative. Because some of these chemicals are highly water soluble, one major pathway for human exposure is the consumption of contaminated drinking water. This study measured concentrations of PFASs in 18 raw drinking water sources and 2 treated wastewater effluents and evaluated 15 full-scale treatment systems for the attenuation of PFASs in water treatment utilities throughout the U.S. A liquid-chromatography tandem mass-spectrometry method was used to enable measurement of a suite of 23 PFASs, including perfluorocarboxylic acids (PFCAs) and perfluorosulfonic acids (PFSAs). Despite the differences in reporting levels, the PFASs that were detected in >70% of the source water samples (n = 39) included PFSAs, perfluorobutane sulfonic acid (74%), perfluorohexane sulfonic acid (79%), and perfluorooctane sulfonic acid (84%), and PFCAs, perfluoropentanoic acid (74%), perfluorohexanoic acid (79%), perfluoroheptanoic acid (74%), and perfluorooctanoic acid (74%). More importantly, water treatment techniques such as ferric or alum coagulation, granular/micro-/ultra- filtration, aeration, oxidation (i.e., permanganate, ultraviolet/hydrogen peroxide), and disinfection (i.e., ozonation, chlorine dioxide, chlorination, and chloramination) were mostly ineffective in removing PFASs. However, anion exchange and granular activated carbon treatment preferably removed longer-chain PFASs and the PFSAs compared to the PFCAs, and reverse osmosis demonstrated significant removal for all the PFASs, including the smallest PFAS, perfluorobutanoic acid. PMID:24275109

Appleman, Timothy D; Higgins, Christopher P; Quiñones, Oscar; Vanderford, Brett J; Kolstad, Chad; Zeigler-Holady, Janie C; Dickenson, Eric R V

2014-03-15

78

Generation of Bladder Urothelium from Human Pluripotent Stem Cells under Chemically Defined Serum- and Feeder-Free System  

PubMed Central

Human stem cells are promising sources for bladder regeneration. Among several possible sources, pluripotent stem cells are the most fascinating because they can differentiate into any cell type, and proliferate limitlessly in vitro. Here, we developed a protocol for differentiation of human pluripotent stem cells (hPSCs) into bladder urothelial cells (BUCs) under a chemically defined culture system. We first differentiated hPSCs into definitive endoderm (DE), and further specified DE cells into BUCs by treating retinoic acid under a keratinocyte-specific serum free medium. hPSC-derived DE cells showed significantly expressed DE-specific genes, but did not express mesodermal or ectodermal genes. After DE cells were specified into BUCs, they notably expressed urothelium-specific genes such as UPIb, UPII, UPIIIa, P63 and CK7. Immunocytochemistry showed that BUCs expressed UPII, CK8/18 and P63 as well as tight junction molecules, E-CADHERIN and ZO-1. Additionally, hPSCs-derived BUCs exhibited low permeability in a FITC-dextran permeability assay, indicating BUCs possessed the functional units of barrier on their surfaces. However, BUCs did not express the marker genes of other endodermal lineage cells (intestine and liver) as well as mesodermal or ectodermal lineage cells. In summary, we sequentially differentiated hPSCs into DE and BUCs in a serum- and feeder-free condition. Our differentiation protocol will be useful for producing cells for bladder regeneration and studying normal and pathological development of the human bladder urothelium in vitro. PMID:24776760

Kang, Minyong; Kim, Hyeon Hoe; Han, Yong-Mahn

2014-01-01

79

Identification of Chemical Constituents in the Extract and Rat Serum from Ziziphus Jujuba Mill by HPLC-PDA-ESI-MSn  

PubMed Central

Chinese jujube (Ziziphus jujuba Mill.) has long been widely used for human consumption and medicinal purposes in China. It has been reported to possess several vital biological activities. However, the systematic study on the chemical constituents absorbed into plasma and their metabolites is still insufficient.A high-performance liquid chromatography-photodiode array detector-electrospray ionization ion-mass spectrometry (HPLC-PDA-ESI-MSn) method was established to analyze the ethanol extract in Ziziphus jujuba Mill and the constituents absorbed into rat serum. In the present study, a dose of 10 mL/Kg of ethanol extract of jujube, which is equivalent to 12.5 g crude dried herb/Kg, was orally administrated to rats. The main components were analyzed in the ethanol extract of Ziziphus jujuba Mill and the parent constituents and metabolites were studied in rat plasma samples after oral administration of the ethanol extract of jujube.D101 macroporous polystyrene resin was a good pretreatment method to obtain better separation and impurity removal effect. Twenty-two compounds were identified in the ethanol extract of Ziziphus jujuba Mill. Four parent compounds and four metabolites were detected in rat serum. Among them, seventeen compounds were reported for the first time.

Wang, Shuping; Zhang, Jingze; Zhang, Zhidan; Gao, Wenyuan; Yan, Yanan; Li, Xia; Liu, Changxiao

2014-01-01

80

Patterns of clinical bioindicators in rat serum following acute exposure to pesticides of different chemical classes  

EPA Science Inventory

There is interest in bioindicators of adverse outcomes in safety assessment and translational research. Chemically-induced neurological effects may be reflected in specific neuronal changes and/or by general stress-like responses, and such bioindicators may be useful for measurin...

81

Perfluoroalkyl contaminants in a food web from Lake Ontario.  

PubMed

Perfluorooctane sulfonate (PFOS) is a persistent and bioaccumulative perfluorinated acid detectable in humans and wildlife worldwide that has alerted scientists to examine the environmental fate of other fluorinated organic contaminants. Recently a homologous series of perfluoroalkyl carboxylates (PFCAs) was detected in the Arctic, yet little is known about their sources, breadth of contamination, or environmental distribution. In this study we analyzed for PFOS, the homologous series of PFCAs ranging from 8 to 15 carbons in chain length, and the PFOS-precursor heptadecafluorooctane sulfonamide (FOSA) in various organisms from a food web of Lake Ontario. The sampled organisms included a top predator fish, lake trout (Salvelinus namaycush), three forage fish species including rainbow smelt (Osmerus mordax), slimy sculpin (Cottus cognatus), and alewife (Alosa pseudoharengus), and two invertebrates Diporeia (Diporeia hoyi) and Mysis (Mysis relicta). A striking finding was that the highest mean concentration for each fluorinated contaminantwas detected in the benthic macroinvertebrate Diporeia, which occupies the lowest trophic level of all organisms analyzed. Perfluorinated acid concentrations in Diporeia were often 10-fold higher than in Mysis, a predominantly pelagic feeder, suggesting that a major source of perfluoroalkyl contaminants to this food web was the sediment, not the water. PFOS was the dominant acid in all samples, but long-chain PFCAs, ranging in length from 8 to 15 carbons, were also detected in most samples between <0.5 and 90 ng/ g. Among Mysis and the more pelagic fish species (e.g. excluding Diporeia and sculpin) there was evidence for biomagnification, but the influence of foraging on highly contaminated Diporeia and sculpin by these fish may have overestimated trophic magnification factors (TMFs), which ranged from 0.51 for FOSA to 5.88 for PFOS. By accounting for the known diet composition of lake trout, it was shown that bioaccumulation was indeed occurring at the top of the food web for all perfluoroalkyl compounds except PFOA. Future monitoring at other locations in Lake Ontario, and in other aquatic environments, is necessary to determine if these food web dynamics are widespread. Archived lake trout samples collected between 1980 and 2001 showed that mean whole body PFOS concentrations increased from 43 to 180 ng/g over this period, but not linearly, and may have been indirectly influenced by the invasion and proliferation of zebra mussels (Dreissena polymorpha) through effects on the population and ecology of forage fishes. PMID:15543740

Martin, Jonathan W; Whittle, D Michael; Muir, Derek C G; Mabury, Scott A

2004-10-15

82

Perfluoroalkyl acid contamination of follicular fluid and its consequence for in vitro oocyte developmental competence.  

PubMed

Perfluoroalkyl acids (PFAAs) have been shown to induce negative effects in laboratory animals and in vitro experiments. Also, PFAAs have been detected in human tissues and body fluids. The ovarian follicle constitutes a fragile micro-environment where interactions between hormones, growth factors, the oocyte and surrounding somatic cells are essential to generate a fully competent oocyte. In vitro experiments suggest that PFAAs can influence this balance, but very scarce in vivo data are available to confirm this assumption. In fact, the potential PFAA-presence in the follicular micro-environment is currently unknown. Therefore, we investigated if PFAAs are present in human follicular fluid and if their presence could be a risk factor for in vivo exposed developing oocytes. Furthermore, we compared the PFAA-distribution within serum and follicular fluid. PFAAs were analyzed by LC/MS in follicular fluid (n=38) and serum (n=20) samples from women undergoing assisted reproductive technologies (ARTs). Statistical models were used to investigate PFAA-distribution in both body fluids, to compare this behavior with the distribution of lipophilic organic pollutants and to explore the relationship between patient characteristics, ART-results and follicular fluid contamination. Perfluorooctane sulfonate (PFOS) was the PFAA found in the highest concentration in follicular fluid [7.5 (0.1-30.4) ng/mL] and serum [7.6 (2.8-12.5) ng/mL]. A new variable, Principal Component 1, representing the overall PFAA-contamination of the follicular fluid samples, was associated with a higher fertilization rate (p<0.05) and a higher proportion of top embryos relative to the amount of retrieved oocytes (p<0.05), after adjusting for age, estradiol-concentration, BMI, male subfertility and the presence of other organic pollutants as explanatory variables. To conclude, overall higher PFAA-contamination in the follicular micro-environment was associated with a higher chance of an oocyte to develop into a high quality embryo. Also, PFAAs have different distribution patterns between serum and follicular fluid compared to the lipophilic organic pollutants. Further research is of course crucial to confirm these new observations. PMID:25089690

Petro, Evi M L; D'Hollander, Wendy; Covaci, Adrian; Bervoets, Lieven; Fransen, Erik; De Neubourg, Diane; De Pauw, Ingrid; Leroy, Jo L M R; Jorssen, Ellen P A; Bols, Peter E J

2014-10-15

83

Assessment of fetal exposure and maternal elimination of perfluoroalkyl substances.  

PubMed

In this study, we estimated the body burden (BB) of perfluoroalkyl substances (PFASs) in a fetus at the time of delivery, and elimination of PFASs in female adults during pregnancy; and explored the isomer branching pattern-related placental transfer of perfluorooctane sulfonate (PFOS). The mean BB of PFASs were 3980 ng for PFOS and 2320 ng for perfluorooctanoic acid (PFOA), therefore, the average daily exposure doses via placental transfer were estimated to be 13.7 and 8.32 ng per day for PFOS and PFOA, respectively, by dividing the BB of PFASs by gestational age. The total daily elimination of PFOS and PFOA in female adults through pregnancy was 30.1 and 11.4 ng per day, which indicates that pregnancy and child birth may reduce the PFASs levels in female adults. Further, branched PFOS was more readily transferred through the placenta than linear PFOS. PMID:24882725

Zhang, Tao; Qin, Xiaolei

2014-08-01

84

Behaviour and fate of perfluoroalkyl and polyfluoroalkyl substances (PFASs) in drinking water treatment: a review.  

PubMed

This article reviews perfluoroalkyl and polyfluoroalkyl substance (PFAS) characteristics, their occurrence in surface water, and their fate in drinking water treatment processes. PFASs have been detected globally in the aquatic environment including drinking water at trace concentrations and due, in part, to their persistence in human tissue some are being investigated for regulation. They are aliphatic compounds containing saturated carbon-fluorine bonds and are resistant to chemical, physical, and biological degradation. Functional groups, carbon chain length, and hydrophilicity/hydrophobicity are some of the important structural properties of PFASs that affect their fate during drinking water treatment. Full-scale drinking water treatment plant occurrence data indicate that PFASs, if present in raw water, are not substantially removed by most drinking water treatment processes including coagulation, flocculation, sedimentation, filtration, biofiltration, oxidation (chlorination, ozonation, AOPs), UV irradiation, and low pressure membranes. Early observations suggest that activated carbon adsorption, ion exchange, and high pressure membrane filtration may be effective in controlling these contaminants. However, branched isomers and the increasingly used shorter chain PFAS replacement products may be problematic as it pertains to the accurate assessment of PFAS behaviour through drinking water treatment processes since only limited information is available for these PFASs. PMID:24216232

Rahman, Mohammad Feisal; Peldszus, Sigrid; Anderson, William B

2014-03-01

85

Time trends between 1987 and 2007 for perfluoroalkyl acids in plasma from Swedish women.  

PubMed

Perfluoroalkyl acids (PFAAs) are a large group of chemicals which are highly persistent in both nature and humans. The use of the most prominent ones, perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), was reduced in the early 21st century, and since then levels in human matrices have decreased. However, these two compounds have been exchanged by other PFAAs, for which time trends have not been as extensively investigated. By the use of 80 plasma samples collected between 1987 and 2007 from healthy women (n=1-9 yearly for 1987-2001, n=15 from 2006, and n=10 from 2007), possible time trends of six PFAAs were assessed. Time trends were evaluated for the entire study period, as well as for three sub-periods. As seen in previous studies, levels of perfluorohexane sulfonate (PFHxS), PFOS, and PFOA peaked during the middle time period (1990-2000), with medians of 0.98 ng mL(-1), 18.06 ng mL(-1), and 3.73 ng mL(-1), respectively. However, levels of perfluorononanic acid (PFNA), perfluorodecanic acid (PFDA), and perfluoroundecanoic acid (PFUnDA) increased over the whole study period and most markedly so after year 2000, with medians of 0.73 ng mL(-1), 0.28 ng mL(-1), and 0.24 ng mL(-1), respectively, during the last study period. PMID:24440039

Axmon, Anna; Axelsson, Jonatan; Jakobsson, Kristina; Lindh, Christian H; Jönsson, Bo A G

2014-05-01

86

Characterization of cultured rat oligodendrocytes proliferating in a serum-free, chemically defined medium  

SciTech Connect

A serumless, chemically defined medium has been developed for the culture of oligodendrocytes isolated from primary neonatal rat cerebral cultures. Combined together, insulin, transferrin, and fibroblast growth factor synergistically induced an essentially homogeneous population (95-98%) of cells expressing glycerol-3-phosphate dehydrogenase activity to undergo cell division. Proliferating cells were characterized by several criteria: (i) ultrastructural analysis by transmission electron microscopy identified the cell type as an oligodendrocyte; (ii) biochemical assays showed expression of three oligodendrocyte biochemical markers, induction of both glycerol phosphate dehydrogenase and lactate dehydrogenase, and presence of 2',3'-cyclic nucleotide 3'-phosphodiesterase; and (iii) immunocytochemical staining showed cultures to be 95-98% positive for glycerol phosphate dehydrogenase, 90% for myelin basic protein, 60-70% for galactocerebroside, and 70% for A2B5.

Saneto, R.P.; de Vellis, J.

1985-05-01

87

High lipophilicity of perfluoroalkyl carboxylate and sulfonate: implications for their membrane permeability.  

PubMed

Here we report on remarkably high lipophilicity of perfluoroalkyl carboxylate and sulfonate. A lipophilic nature of this emerging class of organic pollutants has been hypothesized as an origin of their bioaccumulation and toxicity. Both carboxylate and sulfonate, however, are considered hydrophilic while perfluroalkyl groups are not only hydrophobic but also oleophobic. Partition coefficients of a homologous series of perfluoroalkyl and alkyl carboxylates between water and n-octanol were determined as a measure of their lipophilicity by ion-transfer cyclic voltammetry. Very similar lipophilicity of perfluoroalkyl and alkyl chains with the same length is demonstrated experimentally for the first time by fragment analysis of the partition coefficients. This finding is important for pharmaceutical and biomedical applications of perfluoroalkyl compounds. Interestingly, approximately 2 orders of magnitude higher lipophilicity of a perfluoroalkyl carboxylate or sulfonate in comparison to its alkyl counterpart is ascribed nearly exclusively to their oxoanion groups. The higher lipophilicity originates from a strong electron-withdrawing effect of the perfluoroalkyl group on the adjacent oxoanion group, which is weakly hydrated to decrease its hydrophilicity. In fact, the inductive effect is dramatically reduced for a fluorotelomer with an ethylene spacer between perfluorohexyl and carboxylate groups, which is only as lipophilic as its alkyl counterpart, nonanoate, and is 400 times less lipophilic than perfluorononanoate. The high lipophilicity of perfluoroalkyl carboxylate and sulfonate implies that their permeation across such a thin lipophilic membrane as a bilayer lipid membrane is limited by their transfer at a membrane/water interface. The limiting permeability is lower and less dependent on their lipophilicity than the permeability controlled by their diffusion in the membrane interior as assumed in the classical solubility-diffusion model. PMID:19170492

Jing, Ping; Rodgers, Patrick J; Amemiya, Shigeru

2009-02-18

88

Application of 31P NMR Spectroscopy and Chemical Derivatization for Metabolite Profiling of Lipophilic Compounds in Human Serum  

PubMed Central

New methods for obtaining metabolic fingerprints of biological samples with improved resolution and sensitivity are highly sought for early disease detection, studies of human health and pathophysiology, and for better understanding systems biology. Considering the complexity of biological samples, interest in biochemical class selection through the use of chemoselective probes for improved resolution and quantitation is increasing. Considering the role of lipids in the pathogenesis of a number of diseases, in this study fingerprinting of lipid metabolites was achieved by 31P labeling using the derivatizing agent 2-chloro-4,4,5,5-tetramethyldioxaphospholane. Lipids containing hydroxyl, aldehyde and carboxyl groups were selectively tagged with 31P and then detected with good resolution using 31P NMR by exploiting the 100% natural abundance and wide chemical shift range of 31P. After standardizing the reaction conditions using representative compounds, the derivatization approach was used to profile lipids in human serum. The results show that the 31P derivatization approach is simple, reproducible and highly quantitative, and has the potential to profile a number of important lipids in complex biological samples. PMID:19610016

DeSilva, M. Aruni; Shanaiah, Narasimhamurthy; Gowda, G. A. Nagana; Rosa-Perez, Kellymar; Hanson, Bryan A.; Raftery, Daniel

2010-01-01

89

Chemical Immobilization of Sloth Bears (Melursus ursinus) with Ketamine Hydrochloride and Xylazine Hydrochloride: Hematology and Serum Biochemical Values  

PubMed Central

The present study was conducted to define the physiological responses of captive sloth bears immobilized with ketamine hydrochloride and xylazine hydrochloride and to determine and compare the values of hematology and serum biochemical parameters between sexes. A total of 15 sloth bears were immobilized using combination of ketamine hydrochloride and xylazine hydrochloride drugs at the dose rate of 5.0?milligram (mg) per kg body weight and 2.0?mg per kg body weight, respectively. The use of combination of these drugs was found satisfactory for the chemical immobilization of captive sloth bears. There were no significant differences observed in induction time and recovery time and physiological parameters such as heart rate, respiratory rate, and rectal temperature between sexes. Health related parameters comprising hematological values like packed cell volume (PCV), hemoglobin (Hb), red blood cell count (RBC), erythrocyte indices, and so forth and biochemical values like total protein, blood urea nitrogen (BUN), creatinine, alkaline amino-transferase (ALT), aspartate amino-transferase (AST), and so forth were estimated in 11 (5 males and 6 females) apparently healthy bears. Comparison between sexes revealed significant difference in PCV (P < 0.05) and mean corpuscular hemoglobin concentration (MCHC) (P < 0.05). The study might help to evaluate health profiles of sloth bears for appropriate line treatment. PMID:24876990

Veeraselvam, M.; Sridhar, R.; Perumal, P.; Jayathangaraj, M. G.

2014-01-01

90

Efficient hydrolysis of the chemical warfare nerve agent tabun by recombinant and purified human and rabbit serum paraoxonase 1.  

PubMed

Paraoxonase 1 (PON1) has been described as an efficient catalytic bioscavenger due to its ability to hydrolyze organophosphates (OPs) and chemical warfare nerve agents (CWNAs). It is the future most promising candidate as prophylactic medical countermeasure against highly toxic OPs and CWNAs. Most of the studies conducted so far have been focused on the hydrolyzing potential of PON1 against nerve agents, sarin, soman, and VX. Here, we investigated the hydrolysis of tabun by PON1 with the objective of comparing the hydrolysis potential of human and rabbit serum purified and recombinant human PON1. The hydrolysis potential of PON1 against tabun, sarin, and soman was evaluated by using an acetylcholinesterase (AChE) back-titration Ellman method. Efficient hydrolysis of tabun (100 nM) was observed with ?25-40 mU of PON1, while higher concentration (80-250 mU) of the enzyme was required for the complete hydrolysis of sarin (11 nM) and soman (3 nM). Our data indicate that tabun hydrolysis with PON1 was ?30-60 times and ?200-260 times more efficient than that with sarin and soman, respectively. Moreover, the catalytic activity of PON1 varies from source to source, which also reflects their efficiency of hydrolyzing different types of nerve agents. Thus, efficient hydrolysis of tabun by PON1 suggests its promising potential as a prophylactic treatment against tabun exposure. PMID:21040699

Valiyaveettil, Manojkumar; Alamneh, Yonas; Biggemann, Lionel; Soojhawon, Iswarduth; Doctor, Bhupendra P; Nambiar, Madhusoodana P

2010-12-01

91

Concentrations and patterns of perfluoroalkyl acids in Georgia, USA surface waters near and distant to a major use source  

USGS Publications Warehouse

Perfluoroalkyl acids (PFAAs) are widespread contaminants emanating from, among other sources, the production/degradation of fluorinated chemicals used in surface repellant applications, such as carpet manufacturing. The goal of the present study was to assess the concentrations of PFAAs, including perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUA), and perfluorooctane sulfonamide (PFOSA), in surface waters both near a wastewater land application system (LAS) in Dalton (GA, USA), home to North America's largest carpet manufacturing site, and distant to this location (Altamaha River, GA, USA) to understand the fate of PFAAs in freshwater. Levels of PFAAs were high in the Conasauga River (GA, USA) downstream of the LAS (PFOA, 253-1,150 ng/L; PFOS, 192-318 ng/L; PFNA, 202-369 ng/L; PFDA, 30.1-113 ng/L; PFUA, 58.0-99.2 ng/L; PFOSA, 162-283 ng/L) and in streams and ponds in Dalton (PFOA, 49.9-299 ng/L; PFOS, 15.8-120 ng/L), and were among the highest measured at a nonspill or directrelease location. Perfluoroalkyl acids in the Altamaha River were much lower (PFOA, 3.0-3.1 ng/L; PFOS, 2.6-2.7 ng/L), but were a source of PFAAs to Georgia's estuaries. A preliminary hazard assessment indicated that concentrations of PFOS at two sites in the Conasauga River exceeded the threshold effect predicted for birds consuming aquatic organisms that are exposed continuously to the PFOS levels at these sites. Assuming that toxicity for all PFAAs quantified is equal to that of PFOS, the sum total PFAAs at two sites within the Conasauga River exceeded PFOS thresholds for aquatic and avian species, warranting additional research. ?? 2008 SETAC Printed in the USA.

Konwick, B. J.; Tomy, G. T.; Ismail, N.; Peterson, J. T.; Fauver, R. J.; Higginbotham, D.; Fisk, A. T.

2008-01-01

92

Probing three-dimensional structure of bovine serum albumin by chemical cross-linking and mass spectrometry  

Microsoft Academic Search

Serum albumin is the principal transporter of fatty acids that are otherwise insoluble in circulating plasma. While the crystal\\u000a structure of human serum albumin (HSA) as well as its binding with fatty acids has been characterized, the three dimensional\\u000a structure of bovine serum albumin (BSA) has not been determined although both albumins share 76% sequence homology. In this\\u000a study we

Bill X. Huang; Hee-Yong Kim; Chhabil Dass

2004-01-01

93

Brominated flame retardants and perfluoroalkyl substances in sediments from the Czech aquatic ecosystem.  

PubMed

This study reports results of analysis of various groups of halogenated chemicals, including brominated flame retardants (BFRs), such as polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDs), tetrabromobisphenol A (TBBPA) and perfluoroalkyl substances (PFASs) in 31 sediment samples collected in different localities of the Czech Republic. In this survey, identification of potential sources of these compounds was also performed; therefore several sampling sites located in highly industrialized areas were involved. Concentrations of target groups of analytes determined in sediments from several Czech rivers examined within this study decreased in the following order: decabromodiphenyl ether (BDE 209) > TBBPA~HBCDs~linear perfluorooctane sulfonate (L-PFOS)>other PBDEs~perfluorinated carboxylic acids (PFCAs)~perfluorooctane sulfonamide (FOSA). When compared the contamination by two monitored groups of halogenated compounds, the total content of ?BFRs was significantly higher, i.e. in the range from the method quantification limit (MQL) to 528 ?g/kg dry weight (dw) (median value 5.68 ?g/kg dw), than the total concentration of ?PFASs, that was in the range from MQL to 25.5 ?g/kg dw (median value 1.48 ?g/kg dw). The extremely highest content of BFR group (265-528 ?g/kg dw) was found in sediments collected in sampling sites on the Labe and Lužická Nisa Rivers, which are located in highly chemical industrialized areas and also in the sample from the locality Lampertice obtained from the sedimentation tank close to the factory processing and storing waste. These concentrations were a little bit higher or comparable to those found in similar highly industrialized areas worldwide. PMID:24140701

Hloušková, Veronika; Lanková, Darina; Kalachová, Kamila; Hrádková, Petra; Poustka, Jan; Hajšlová, Jana; Pulkrabová, Jana

2014-02-01

94

Evaluating the additivity of perfluoroalkyl acids in binary combinations on peroxisome proliferator-activated receptor-? activation.  

PubMed

Perfluoroalkyl acids (PFAAs) are found globally in the environment, detected in humans and wildlife, and are typically present as mixtures of PFAA congeners. Mechanistic studies have found that responses to PFAAs are mediated in part by PPAR?. Our previous studies showed that individual PFAAs activate PPAR? transfected into COS-1 cells. The goal of the current study was to determine if binary combinations of perfluorooctanoic acid (PFOA) and another PFAA act in an additive fashion to activate PPAR? in the mouse one-hybrid in vitro model. COS-1 cells were transiently transfected with mouse PPAR? luciferase reporter construct and exposed to either vehicle control (0.1% DMSO or water), PPAR? agonist (WY14643, 10 ?M), PFOA at 1-128?M, perfluorononanoic acid (PFNA) at 1-128 ?M, perfluorohexanoic acid (PFHxA) at 8-1024 ?M, perfluorooctane sulfonate (PFOS) at 4-384 ?M or perfluorohexane sulfonate (PFHxS) at 8-2048 ?M to generate sigmoidal concentration-response curves. In addition, cells were exposed to binary combinations of PFOA+either PFNA, PFHxA, PFOS or PFHxS in an 8×8 factorial design. The concentration-response data for individual chemicals were fit to sigmoidal curves and analyzed with nonlinear regression to generate EC??s and Hillslopes, which were used in response-addition and concentration-addition models to calculate predicted responses for mixtures in the same plate. All PFOA+PFAA combinations produced concentration-response curves that were closely aligned with the predicted curves for both response addition and concentration addition at low concentrations. However, at higher concentrations of all chemicals, the observed response curves deviated from the predicted models of additivity. We conclude that binary combinations of PFAAs behave additively at the lower concentration ranges in activating PPAR? in this in vitro system. PMID:24374136

Wolf, Cynthia J; Rider, Cynthia V; Lau, Christopher; Abbott, Barbara D

2014-02-28

95

Neurotoxic effects of perfluoroalkylated compounds: mechanisms of action and environmental relevance.  

PubMed

Perfluoroalkylated compounds (PFCs) are used in fire-fighting foams, treatment of clothes, carpets and leather products, and as lubricants, pesticides, in paints and medicine. Recent developments in chemical analysis have revealed that fluorinated compounds have become ubiquitously spread and are regarded as a potential threats to the environment. Due to the carbon-fluorine bond, which has a very high bond strength, these chemicals are extremely persistent towards degradation and some PFCs have a potential for bioaccumulation in organisms. Of particular concern has been the developmental toxicity of PFOS and PFOA, which has been manifested in rodent studies as high mortality of prenatally exposed newborn rats and mice within 24 h after delivery. The nervous system appears to be one of the most sensitive targets of environmental contaminants. The serious developmental effects of PFCs have lead to the upcoming of studies that have investigated neurotoxic effects of these substances. In this review the major findings of the neurotoxicity of the main PFCs and their suggested mechanisms of action are presented. The neurotoxic effects are discussed in light of other toxic effects of PFCs to indicate the significance of PFCs as neurotoxicants. The main findings are that PFCs may induce neurobehavioral effects, particularly in developmentally exposed animals. The effects are, however, subtle and inconclusive and are often induced at concentrations where other toxic effects also are expected. Mechanistic studies have shown that PFCs may affect the thyroid system, influence the calcium homeostasis, protein kinase C, synaptic plasticity and cellular differentiation. Compared to other environmental toxicants the human blood levels of PFCs are high and of particular concern is that susceptible groups may be exposed to a cocktail of substances that in combination reach harmful concentrations. PMID:22456834

Mariussen, Espen

2012-09-01

96

Variable effects of chemical allergens on serum IgE concentration in mice. Preliminary evaluation of a novel approach to the identification of respiratory sensitizers.  

PubMed

A wide variety of chemicals may induce allergic contact dermatitis (contact sensitivity). Some chemical allergens may, in addition, cause respiratory sensitization. Topical exposure of mice to contact and respiratory chemical sensitizers results in the initiation of divergent immune responses characteristic of preferential activation of different functional subpopulations of T helper (TH) cells. In the present study we have sought to make use of these differences, particularly differences in the ability of contact and respiratory allergens to provoke IgE responses, and to question whether opportunities exist for the identification of chemicals with the potential for respiratory sensitization. We have examined alterations in the serum concentration of IgE following topical exposure of mice to seven chemical allergens; trimellitic anhydride (TMA), phthalic anhydride, diphenylmethane-4,4'-diisocyanate (MDI), dicyclohexylmethane-4,4'-diisocyanate (HMDI), isophorone diisocyanate (IPDI), oxazolone and 2,4-dinitrochlorobenzene (DNCB). Three of these--TMA, phthalic anhydride and MDI--are known human respiratory sensitizers. The other four--HMDI, IPDI, oxazolone and DNCB--appear not to cause respiratory allergy, or at least have a very limited potential to do so. At the concentrations tested, exposure to all chemicals caused a lymphocyte proliferative response in lymph nodes draining the site of application. However, exposure only to TMA, phthalic anhydride and MDI resulted in a substantial increase in the concentration of serum IgE. Treatment with HMDI and IPDI failed to induce any change in serum IgE concentration. DNCB and oxazolone caused only small and transient elevations of IgE that were considerably less marked than those observed with respiratory sensitizers.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1447476

Dearman, R J; Basketter, D A; Kimber, I

1992-10-01

97

Perfluoroalkyl acids in urban stormwater runoff: influence of land use.  

PubMed

Perfluoroalkyl acids (PFAAs) are persistent organic pollutants in the environment and have been reported to have nonpoint sources. In this study, six PFAAs with different chain lengths were monitored in stormwater runoff from seven storm events (2009-2011) at various outfall locations corresponding to different watershed land uses. We found PFAA(s) in 100% of stormwater runoff samples. Monitoring results and statistical analysis show that PFAAs in stormwater runoff from residential areas mainly came from rainfall. On the other hand, non-atmospheric sources at both industrial and commercial areas contributed PFAAs in stormwater runoff. The mass flux of PFAAs from stormwater runoff in the Twin Cities (Minneapolis and St. Paul, MN) metropolitan area is estimated to be about 7.86 kg/year. In addition, for the first time, we monitored PFAAs on the particles/debris in stormwater runoff and found high-level PFOS on the particulate matter in runoff collected from both industrial and commercial areas; the levels were so high that the finding could not be explained by the solid-water partitioning or adsorption. PFOS on the particulate matter is suspected to have originated from industrial/commercial products, entering the waste stream as PFOS containing particles. PMID:22154107

Xiao, Feng; Simcik, Matt F; Gulliver, John S

2012-12-15

98

Exposure of Perfluorinated Chemicals through Lactation: Levels of Matched Human Milk and Serum and a Temporal Trend, 1996–2004, in Sweden  

PubMed Central

Background Only limited data exist on lactation as an exposure source of persistent perfluorinated chemicals (PFCs) for children. Objectives We studied occurrence and levels of PFCs in human milk in relation to maternal serum together with the temporal trend in milk levels between 1996 and 2004 in Sweden. Matched, individual human milk and serum samples from 12 primiparous women in Sweden were analyzed together with composite milk samples (25–90 women/year) from 1996 to 2004. Results Eight PFCs were detected in the serum samples, and five of them were also above the detection limits in the milk samples. Perfluorooctanesulfonate (PFOS) and perfluorohexanesulfonate (PFHxS) were detected in all milk samples at mean concentrations of 0.201 ng/mL and 0.085 ng/mL, respectively. Perfluorooctanesulfonamide (PFOSA), perfluorooctanoic acid (PFOA), and perfluorononanoic acid (PFNA) were detected less frequently. Discussion The total PFC concentration in maternal serum was 32 ng/mL, and the corresponding milk concentration was 0.34 ng/mL. The PFOS milk level was on average 1% of the corresponding serum level. There was a strong association between increasing serum concentration and increasing milk concentration for PFOS (r2 = 0.7) and PFHxS (r2 = 0.8). PFOS and PFHxS levels in composite milk samples were relatively unchanged between 1996 and 2004, with a total variation of 20 and 32% coefficient of variation, respectively. Conclusion The calculated total amount of PFCs transferred by lactation to a breast-fed infant in this study was approximately 200 ng/day. Lactation is a considerable source of exposure for infants, and reference concentrations for hazard assessments are needed. PMID:17384769

Kärrman, Anna; Ericson, Ingrid; van Bavel, Bert; Darnerud, Per Ola; Aune, Marie; Glynn, Anders; Lignell, Sanna; Lindström, Gunilla

2007-01-01

99

Persistence of perfluoroalkyl acid precursors in AFFF-impacted groundwater and soil.  

PubMed

Several classes of polyfluorinated chemicals that are potential precursors to the perfluorinated carboxylates and sulfonates are present in aqueous film-forming foams (AFFF). To assess the persistence of these AFFF-derived precursors, groundwater, soil, and aquifer solids were obtained in 2011 from an unlined firefighter training area at a U.S. Air Force Base where AFFF was regularly used between 1970 and 1990. To measure the total concentration of perfluorinated carboxylate and sulfonate precursors in archived AFFF formulations and AFFF-impacted environmental samples, a previously developed assay that uses hydroxyl radical to oxidize precursors to perfluorinated carboxylates was adapted for these media. This assay was employed along with direct measurement of 22 precursors found in AFFF and a suite of other poly- and perfluoroalkyl substances (PFASs). On a molar basis, precursors accounted for 41-100% of the total concentration of PFASs in archived AFFF formulations. In the training area, precursors measured by the oxidation assay accounted for an average of 23% and 28% of total PFASs (i.e., precursors and perfluorinated carboxylates and sulfonates) in groundwater and solids samples, respectively. One precursor in AFFF, perfluorohexane sulfonamide amine, was observed on several highly contaminated soil and aquifer solids samples, but no other precursors present in AFFF formulations were detected in any samples at this field site. Suspected intermediate transformation products of precursors in AFFF that were directly measured accounted for approximately half of the total precursor concentration in samples from the training site. The fraction of PFASs consisting of perfluorinated carboxylates and sulfonates was greater in groundwater and solid samples than in any archived AFFF formulations, suggesting that much of the mass of precursors released at the site was converted to perfluorinated carboxylates and sulfonates. The precursors that have persisted at this site may generate significant amounts of additional perfluorinated carboxylates and sulfonates upon remediation of contaminated groundwater or aquifer solids. PMID:23886337

Houtz, Erika F; Higgins, Christopher P; Field, Jennifer A; Sedlak, David L

2013-08-01

100

Chemical conversion of benzo(e)pyrene by aqueous serum albumin to pyrene-like product: fluorescence method  

SciTech Connect

The interaction of benzo(e)pyrene, an atmospheric pollutant formed during the burning of organic materials, and bovine serum albumin (BSA) was studied to determine a pyrene-type metabolite is formed. (ACR)

Srinivasan, B.N.; Fujimori, E.

1980-01-01

101

Perfluoroalkyl substances during pregnancy and validated preeclampsia among nulliparous women in the Norwegian Mother and Child Cohort Study.  

PubMed

Perfluoroalkyl substances (PFAS) are persistent and ubiquitous environmental contaminants, and human exposure to these substances may be related to preeclampsia, a common pregnancy complication. Previous studies have found serum concentrations of PFAS to be positively associated with pregnancy-induced hypertension and preeclampsia in a population with high levels of exposure to perfluorooctanoate. Whether this association exists among pregnant women with background levels of PFAS exposure is unknown. Using data from the Norwegian Mother and Child Cohort Study conducted by the Norwegian Institute of Public Health, we carried out a study of nulliparous pregnant women enrolled in 2003-2007 (466 cases, 510 noncases) to estimate associations between PFAS concentrations and an independently validated diagnosis of preeclampsia. We measured levels of 9 PFAS in maternal plasma extracted midpregnancy; statistical analyses were restricted to 7 PFAS that were quantifiable in more than 50% of samples. In proportional hazards models adjusted for maternal age, prepregnancy body mass index (weight (kg)/height (m)(2)), educational level, and smoking status, we observed no strongly positive associations between PFAS levels and preeclampsia. We found an inverse association between preeclampsia and the highest quartile of perfluoroundecanoic acid concentration relative to the lowest quartile (hazard ratio = 0.55, 95% confidence interval: 0.38, 0.81). Overall, our findings do not support an increased risk of preeclampsia among nulliparous Norwegian women with background levels of PFAS exposure. PMID:24557813

Starling, Anne P; Engel, Stephanie M; Richardson, David B; Baird, Donna D; Haug, Line S; Stuebe, Alison M; Klungsøyr, Kari; Harmon, Quaker; Becher, Georg; Thomsen, Cathrine; Sabaredzovic, Azemira; Eggesbø, Merete; Hoppin, Jane A; Travlos, Gregory S; Wilson, Ralph E; Trogstad, Lill I; Magnus, Per; Longnecker, Matthew P

2014-04-01

102

Exposure and effects of perfluoroalkyl substances in tree swallows nesting in Minnesota and Wisconsin, USA  

EPA Science Inventory

The exposure and effects of perfluoroalkyl substances (PFASs) were studied at eight locations in Minnesota and Wisconsin between 2007 and 2011 using tree swallows (Tachycineta bicolor) as sentinel species. These eight sites covered a range of possible exposure pathways and ecolog...

103

Occurrence of Perfluoroalkyl Surfactants in Water, Fish, and Birds from New York State  

Microsoft Academic Search

Concentrations of perfluorooctanesulfonate (PFOS) and several other perfluoroalkyl surfactants (PASs) were determined in nine\\u000a major water bodies (n = 51) of New York State (NYS). These PASs were also measured in the livers of two species of sport fish (n = 66) from 20 inland lakes in NYS. Finally, perfluorinated compounds were measured in the livers of 10 species of

Ewan Sinclair; David T. Mayack; Kenneth Roblee; Nobuyoshi Yamashita; Kurunthachalam Kannan

2006-01-01

104

EVALUATION OF PERFLUOROALKYL ACID ACTIVITY USING PRIMARY MOUSE AND HUMAN HEPATOCYTES  

EPA Science Inventory

While perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) have been studied at length, less is know about the biological activity of other environmental perfluoroalkyl acids (pFAAs). Using a transient transfection assay developed in COS-l cells, our group has previ...

105

Evaluation of Perfluoroalkyl Acid Activity Using Primary Mouse and Human Hepatocytes.  

EPA Science Inventory

While perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) have been studied at length, less is known about the biological activity of other perfluoroalkyl acids (PFAAs) in the environment. Using a transient transfection assay developed in COS-1 cells, our group h...

106

Testing for departures from additivity in mixtures of perfluoroalkyl acids (PFAAs)  

EPA Science Inventory

This study is a follow-up to a paper by Carr, et al. that determined a design structure to optimally test for departures from additivity in a fixed ratio mixture of four perfluoroalkyl acids (PFAAs) using an in vitro transiently-transfected COS- 1 PPARa reporter model with an NHA...

107

Perfluoroalkyl acids and the isomers of perfluorooctanesulfonate and perfluorooctanoate in the sera of 50 new couples in Tianjin, China.  

PubMed

A total of 100 serum samples from 50 new couples (none of the females in this study has ever been pregnant) in Tianjin, North China, were analyzed for eleven perfluoroalkyl acids (PFAAs) with isomer-specific method. Among all samples, total perfluorooctanesulfonate (?PFOS, mean 11.3 ng/mL) was predominant followed by total perfluorooctanoate (?PFOA, 2.95 ng/mL), perfluorodecanoate (PFDA, 1.17 ng/mL), perfluorononanoate (PFNA, 0.93 ng/mL) and perfluorohexanesulfonate (PFHxS, 0.67 ng/mL). The mean concentrations of ?PFOS and PFHxS in males (14.2 and 0.89 ng/mL) were significantly higher (p=0.001) than in females (8.36 and 0.45 ng/mL). No statistical difference between genders was observed for the other PFAAs. This suggests that menstruation is one important elimination pathway for ?PFOS and PFHxS in females. Linear PFOA was the dominant isomer with mean proportion of 99.7%, suggesting that telomeric PFOA (and its precursors), which contains almost pure linear isomer, might be the dominant exposure source of PFOA in Tianjin. On average, the proportion of linear PFOS (n-PFOS) was 59.2% of ?PFOS, which was lower than that in technical PFOS products (ca. 70% linear). Except perfluoroisopropyl PFOS, all the other monomethyl branched PFOS isomers were enriched in human serum compared to the commercial products, suggesting the monomethyl branched PFOS precursors were preferentially biotransformed in humans. PMID:24747327

Zhang, Yifeng; Jiang, Weiwei; Fang, Shuhong; Zhu, Lingyan; Deng, Jimin

2014-07-01

108

Food risk assessment for perfluoroalkyl acids and brominated flame retardants in the French population: results from the second French total diet study.  

PubMed

To determine the exposure of the French population to toxic compounds contaminating the food chain, a total diet study was performed in France between 2007 and 2009. This study was designed to reflect the consumption habits of the French population and covered the most important foods in terms of consumption, selected nutrients and contribution to contamination. Based on French consumption data, the present study reports the dietary exposure to perfluoroalkyl acids (16 congeners) and brominated flame retardants (polybrominated diphenyl ethers, hexabromocyclododecane and polybrominated biphenyls). Comparison of the calculated dietary exposures with the generally accepted health-based guidance values revealed that most compounds do not pose any risk. There are however knowledge gaps for some congeners in these large chemical classes. PMID:24529894

Rivière, G; Sirot, V; Tard, A; Jean, J; Marchand, P; Veyrand, B; Le Bizec, B; Leblanc, J C

2014-09-01

109

Calcium-Regulated Differentiation of Normal Human Epidermal Keratinocytes in Chemically Defined Clonal Culture and Serum-Free Serial Culture  

Microsoft Academic Search

An improved serum-free culture system has been developed for normal human epidermal keratinocytes (HK), Short-term clonal growth and differentiation studies are routinely performed in a defined medium consisting of optimized nutrient medium MCDB 153 supplemented with epidermal growth factor, insulin, hydrocortisone, ethanolamine, and phosphoethanolamine. A small amount of whole bovine pituitary extract (wBPE) is added for initiation of primary cultures,

Steven T. Boyce; Richard G. Ham

1983-01-01

110

Reductive degradation of perfluoroalkyl compounds with aquated electrons generated from iodide photolysis at 254 nm.  

PubMed

The perfluoroalkyl compounds (PFCs), perfluoroalkyl sulfonates (PFXS) and perfluoroalkyl carboxylates (PFXA) are environmentally persistent and recalcitrant towards most conventional water treatment technologies. Here, we complete an in depth examination of the UV-254 nm production of aquated electrons during iodide photolysis for the reductive defluorination of six aquated perfluoroalkyl compounds (PFCs) of various headgroup and perfluorocarbon tail length. Cyclic voltammograms (CV) show that a potential of +2.0 V (vs. NHE) is required to induce PFC oxidation and -1.0 V is required to induce PFC reduction indicating that PFC reduction is the thermodynamically preferred process. However, PFCs are observed to degrade faster during UV(254 nm)/persulfate (S(2)O(8)(2-)) photolysis yielding sulfate radicals (E° = +2.4 V) as compared to UV(254 nm)/iodide (I(-)) photolysis yielding aquated electrons (E° = -2.9 V). Aquated electron scavenging by photoproduced triiodide (I(3)(-)), which achieved a steady-state concentration proportional to [PFOS](0), reduces the efficacy of the UV/iodide system towards PFC degradation. PFC photoreduction kinetics are observed to be dependent on PFC headgroup, perfluorocarbon chain length, initial PFC concentration, and iodide concentration. From 2 to 12, pH had no observable effect on PFC photoreduction kinetics, suggesting that the aquated electron was the predominant reductant with negligible contribution from the H-atom. A large number of gaseous fluorocarbon intermediates were semi-quantitatively identified and determined to account for ?25% of the initial PFOS carbon and fluorine. Reaction mechanisms that are consistent with kinetic observations are discussed. PMID:22025132

Park, Hyunwoong; Vecitis, Chad D; Cheng, Jie; Dalleska, Nathan F; Mader, Brian T; Hoffmann, Michael R

2011-12-01

111

Tribological reactions of perfluoroalkyl polyether oils with stainless steel under ultrahigh vacuum conditions at room temperature  

NASA Technical Reports Server (NTRS)

The reaction between three types of commercial perfluoroalkyl polyether (PFPE) oils and stainless steel 440C was investigated experimentally during sliding under ultrahigh vacuum conditions at room temperature. It is found that the tribological reaction of PFPE is mainly affected by the activity of the mechanically formed fresh surfaces of metals rather than the heat generated at the sliding contacts. The fluorides formed on the wear track act as a boundary layer, reducing the friction coefficient.

Mori, Shigeyuki; Morales, Wilfredo

1989-01-01

112

Distribution of perfluoroalkyl compounds in seawater from northern Europe, Atlantic Ocean, and Southern Ocean.  

PubMed

The global distribution of perfluoroalkyl compounds (PFCs) were investigated in surface water samples collected onboard the Polarstern in Northern Europe, Atlantic and Southern Ocean (52 degrees N-69 degrees S) in 2008. The water samples were solid-phase extracted with Oasis WAX cartridges and analysed using the high-performance liquid chromatography interfaced to tandem mass spectrometry. Concentrations of various PFCs, including C(4), C(6), C(8) perfluoroalkyl sulfonates (PFSAs), perfluorooctane sulfinate (PFOSi), C(5)-C(12) perfluoroalkyl carboxylic acids (PFCA) and perfluorooctane sulfonamide (FOSA) were quantified. Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) were the predominant compounds with a maximum concentration of 232 and 223pgL(-1), respectively. Results indicate that industrial areas like the European Continent act as source of PFCs, while ocean water is an important as a sink as well as the transport medium of these compounds. Interestingly, in the equator area the summation operatorPFC concentration increased, which indicates that there exists an atmospheric or other unknown input source of PFCs. In the Southern Ocean only PFOS was detected which could be caused by atmospheric transport of its precursors. PMID:20015534

Ahrens, Lutz; Xie, Zhiyong; Ebinghaus, Ralf

2010-02-01

113

Toxicokinetics of seven perfluoroalkyl sulfonic and carboxylic acids in pigs fed a contaminated diet.  

PubMed

The transfer of a mixture of perfluoroalkyl acids (PFAAs) from contaminated feed into the edible tissues of 24 fattening pigs was investigated. Four perfluoroalkyl sulfonic (PFSAs) and three perfluoroalkyl carboxylic acids (PFCAs) were quantifiable in feed, plasma, edible tissues, and urine. As percentages of unexcreted PFAA, the substances accumulated in plasma (up to 51%), fat, and muscle tissues (collectively, meat 40-49%), liver (under 7%), and kidney (under 2%) for most substances. An exception was perfluorooctanesulfonic acid (PFOS), with lower affinity for plasma (23%) and higher for liver (35%). A toxicokinetic model is developed to quantify the absorption, distribution, and excretion of PFAAs and to calculate elimination half-lives. Perfluorohexanoic acid (PFHxA), a PFCA, had the shortest half-life at 4.1 days. PFSAs are eliminated more slowly (e.g., half-life of 634 days for PFOS). PFAAs in pigs exhibit longer elimination half-lives than in most organisms reported in the literature, but still shorter than in humans. PMID:24892814

Numata, Jorge; Kowalczyk, Janine; Adolphs, Julian; Ehlers, Susan; Schafft, Helmut; Fuerst, Peter; Müller-Graf, Christine; Lahrssen-Wiederholt, Monika; Greiner, Matthias

2014-07-16

114

Dietary exposure to perfluoroalkyl acids of specific French adult sub-populations: high seafood consumers, high freshwater fish consumers and pregnant women.  

PubMed

Perfluoroalkyl acids (PFAAs) are globally found in various media, including food and especially fishery products. In the present study, the dietary exposure to 15 perfluoroalkyl acids was assessed for 3 French adult populations, namely high seafood consumers, high freshwater fish consumers, and pregnant women. Purified food extracts were analysed by LC-MS/MS and PFBA, PFPA, PFHxA, PFHpA, PFOA, PFNA, PFDA, PFUnA, PFTrDA, PFTeDA, PFBS, PFHxS, PFHpS, PFOS and PFDS were monitored and quantified according to the isotope dilution principle. Under lower bound (LB) hypothesis (i.e. contamination valueschemicals. PMID:24530183

Yamada, A; Bemrah, N; Veyrand, B; Pollono, C; Merlo, M; Desvignes, V; Sirot, V; Marchand, P; Berrebi, A; Cariou, R; Antignac, J P; Le Bizec, B; Leblanc, J C

2014-09-01

115

Indoor and outdoor air concentrations and phase partitioning of perfluoroalkyl sulfonamides and polybrominated diphenyl ethers.  

PubMed

Perfluoroalkyls (PFAs) and polybrominated diphenyl ethers (PBDEs) are two classes of emerging persistent organic pollutants (POPs) that are widely used in domestic and workplace products. These compounds also occur in remote locations such as the Arctic where they are accumulated in the food chain. This study makes connections between indoor sources of these chemicals and the potential and mode for their transport in air. In the case of the PFAs, three perfluoralkyl sulfonamides (PFASs) were investigated--N-methyl perfluorooctane sulfonamidoethanol (MeFOSE), N-ethyl perfluorooctane sulfonamidoethanol (EtFOSE), and N-methyl perfluorooctane sulfonamidethylacrylate (MeFOSEA). These are believed to act as precursors that eventually degrade to perfluorooctane sulfonate (PFOS), which is detected in samples from remote regions. High-volume samples were collected for indoor and outdoor air to investigate the source signature and strength. Mean indoor air concentrations (pg/m3) were 2590 (MeFOSE), 770 (EtFOSE), and 630 (sigmaPBDE). The ratios of concentration between indoor and outdoor air were 110 for MeFOSE, 85 for EtFOSE, and 15 for sigmaPBDE. The gas and particle phases were collected separately to investigate the partitioning characteristics of these chemicals. Measured particulate percentages were compared to predicted values determined using models based on the octanol-air partition coefficient (K(OA)) and supercooled liquid vapor pressure (pL(o)); these models were previously developed for nonpolar, hydrophobic chemicals. To make this comparison for the three PFASs, it was necessary to measure their K(OA) and vapor pressure. K(OA) values were measured as a function of temperature (0 to +20 degrees C). Values of log K(OA) at 20 degrees C were 7.70, 7.78, and 7.87 for MeFOSE, EtFOSE, and MeFOSEA, respectively. Partitioning to octanol increased at colder temperatures, and the enthalpies associated with octanol-air transfer (deltaH(OA), kJ/mol) were 68-73 and consistent with previous measurements for nonpolar hydrophobic chemicals. Solid-phase vapor pressures (pS(o)) were measured at room temperature (23 degrees C) by the gas saturation method. Values of pS(o) (Pa) were 4.0 x 10(-4), 1.7 x 10(-3), and 4.1 x 10(-4), respectively. These were converted to pL(o) for describing particle-gas exchange. Both the pL(o)-based model and the K(OA) model worked well for the PBDEs but were not valid for the PFASs, greatly underpredicting particulate percentages. These results suggest that existing K(OA)- and pL(o)-based models of partitioning will need to be recalibrated for PFASs. PMID:15046331

Shoeib, Mahiba; Harner, Tom; Ikonomou, Michael; Kannan, Kurunthachalam

2004-03-01

116

Investigation of the Associations Between Low-Dose Serum Perfluorinated Chemicals and Liver Enzymes in US Adults  

Microsoft Academic Search

OBJECTIVES:Perfluorinated chemicals (PFCs) have been largely used for years in a variety of products worldwide. However, the toxic effect of PFCs on exposure to the liver in the general population has not yet been determined.METHODS:In this study, 2,216 adults (18 years of age or older) were recruited in a National Health and Nutrition Examination Survey (NHANES) in 1999–2000 and 2003–2004

Chien-Yu Lin; Lian-Yu Lin; Chih-Kang Chiang; Wei-Jie Wang; Yi-Ning Su; Kuan-Yu Hung; Pau-Chung Chen

2010-01-01

117

Serum sickness  

MedlinePLUS

Serum sickness is a reaction that is similar to an allergy. The immune system reacts to medications ... immune response against the toxin or germ. During serum sickness, the immune system falsely identifies a protein ...

118

Development and Comparison of Three Liquid Chromatography-Atmospheric Pressure Chemical Ionization/Mass Spectrometry Methods for Determining Vitamin D Metabolites in Human Serum  

PubMed Central

Liquid chromatographic methods with atmospheric pressure chemical ionization mass spectrometry were developed for the determination of the vitamin D metabolites 25-hydroxyvitamin D2 (25(OH)D2), 25-hydroxyvitamin D3 (25(OH)D3), and 3-epi-25-hydroxyvitamin-D3 (3-epi-25(OH)D3) in the four Levels of SRM 972, Vitamin D in Human Serum. One method utilized a C18 column, which separates 25(OH)D2 and 25(OH)D3, and one method utilized a CN column that also resolves the diastereomers 25(OH)D3 and 3-epi-25(OH)D3. Both methods utilized stable isotope labeled internal standards for quantitation of 25(OH)D2 and 25(OH)D3. These methods were subsequently used to evaluate SRM 909c Human Serum, and 25(OH)D3 was the only vitamin D metabolite detected in this material. However, SRM 909c samples contained matrix peaks that interfered with the determination of the [2H6]-25(OH)D3 peak area. The chromatographic conditions for the C18 column were modified to remove this interference, but conditions that separated the matrix peaks from [2H6]-25(OH)D3 on the CN column could not be identified. The alternate internal standard [2H3]-25(OH)D3 did not suffer from matrix interferences and was used for quantitation of 25(OH)D3 in SRM 909c. During the evaluation of SRM 909c samples, a third method was developed using a pentafluorophenylpropyl column that also separates the diastereomers 25(OH)D3 and 3-epi-25(OH)D3. The 25(OH)D3 was measured in SRM 909c using all three methods, and the results were compared. PMID:22533908

Bedner, Mary; Phinney, Karen W.

2012-01-01

119

TOXICOGENOMIC STUDY OF TRIAZOLE FUNGICIDES AND PERFLUOROALKYL ACIDS  

EPA Science Inventory

Toxicogenomic analysis of five environmental contaminants was performed to investigate the ability of genomics to categorize chemicals and elucidate mechanisms of toxicity. Three triazole antifungals (myclobutanil, propiconazole and triadimefon) and two perfluorinated compounds (...

120

Contamination profiles of perfluoroalkyl substances in five typical rivers of the Pearl River Delta region, South China.  

PubMed

A survey on contamination profiles of eighteen perfluoroalkyl substances (PFASs) was performed via high performance liquid chromatography-tandem mass spectrometry for surface water and sediments from five typical rivers of the Pearl River Delta region, South China in summer and winter in 2012. The total concentrations of the PFASs in the water phase of the five rivers ranged from 0.14 to 346.72 ng L(-1). The PFAS concentrations in the water phase were correlated positively to some selected water quality parameters such as chemical oxygen demand (COD) (0.7913) and conductivity (0.5642). The monitoring results for the water samples showed significant seasonal variations, while those for the sediment samples showed no obvious seasonal variations. Among the selected 18 PFASs, perfluorooctane sulfonic acid (PFOS) was the dominant PFAS compound both in water and sediment for two seasons with its maximum concentration of 320.5 ng L(-1) in water and 11.4 ng g(-1) dry weight (dw) in sediment, followed by perfluorooctanoic acid (PFOA) with its maximum concentration of 26.48 ng L(-1) in water and 0.99 ng g(-1) dw in sediment. PFOS and PFOA were found at relatively higher concentrations in the Shima River and Danshui River than in the other three rivers (Xizhijiang River, Dongjiang River and Shahe River). The principal component analysis for the PFASs concentrations in water and sediment separated the sampling sites into two groups: rural and agricultural area, and urban and industrial area, suggesting the PFASs in the riverine environment were mainly originated from industrial and urban activities in the region. PMID:25113179

Pan, Chang-Gui; Ying, Guang-Guo; Liu, You-Sheng; Zhang, Qian-Qian; Chen, Zhi-Feng; Peng, Feng-Jiao; Huang, Guo-Yong

2014-11-01

121

Estrogen-Like Activity of Perfluoroalkyl Acids In Vivo and Interaction with Human and Rainbow Trout Estrogen Receptors In Vitro  

PubMed Central

The objectives of this study were to determine the structural characteristics of perfluoroalkyl acids (PFAAs) that confer estrogen-like activity in vivo using juvenile rainbow trout (Oncorhynchus mykiss) as an animal model and to determine whether these chemicals interact directly with the estrogen receptor (ER) using in vitro and in silico species comparison approaches. Perfluorooctanoic (PFOA), perfluorononanoic (PFNA), perfluorodecanoic (PFDA), and perfluoroundecanoic (PFUnDA) acids were all potent inducers of the estrogen-responsive biomarker protein vitellogenin (Vtg) in vivo, although at fairly high dietary exposures. A structure-activity relationship for PFAAs was observed, where eight to ten fluorinated carbons and a carboxylic acid end group were optimal for maximal Vtg induction. These in vivo findings were corroborated by in vitro mechanistic assays for trout and human ER. All PFAAs tested weakly bound to trout liver ER with half maximal inhibitory concentration (IC50) values of 15.2–289?M. Additionally, PFOA, PFNA, PFDA, PFUnDA, and perlfuorooctane sulfonate (PFOS) significantly enhanced human ER?-dependent transcriptional activation at concentrations ranging from 10–1000nM. Finally, we employed an in silico computational model based upon the crystal structure for the human ER? ligand-binding domain complexed with E2 to structurally investigate binding of these putative ligands to human, mouse, and trout ER?. PFOA, PFNA, PFDA, and PFOS all efficiently docked with ER? from different species and formed a hydrogen bond at residue Arg394/398/407 (human/mouse/trout) in a manner similar to the environmental estrogens bisphenol A and nonylphenol. Overall, these data support the contention that several PFAAs are weak environmental xenoestrogens of potential concern. PMID:21163906

Benninghoff, Abby D.; Bisson, William H.; Koch, Daniel C.; Ehresman, David J.; Kolluri, Siva K.; Williams, David E.

2011-01-01

122

Estrogen-like activity of perfluoroalkyl acids in vivo and interaction with human and rainbow trout estrogen receptors in vitro.  

PubMed

The objectives of this study were to determine the structural characteristics of perfluoroalkyl acids (PFAAs) that confer estrogen-like activity in vivo using juvenile rainbow trout (Oncorhynchus mykiss) as an animal model and to determine whether these chemicals interact directly with the estrogen receptor (ER) using in vitro and in silico species comparison approaches. Perfluorooctanoic (PFOA), perfluorononanoic (PFNA), perfluorodecanoic (PFDA), and perfluoroundecanoic (PFUnDA) acids were all potent inducers of the estrogen-responsive biomarker protein vitellogenin (Vtg) in vivo, although at fairly high dietary exposures. A structure-activity relationship for PFAAs was observed, where eight to ten fluorinated carbons and a carboxylic acid end group were optimal for maximal Vtg induction. These in vivo findings were corroborated by in vitro mechanistic assays for trout and human ER. All PFAAs tested weakly bound to trout liver ER with half maximal inhibitory concentration (IC(50)) values of 15.2-289 ?M. Additionally, PFOA, PFNA, PFDA, PFUnDA, and perlfuorooctane sulfonate (PFOS) significantly enhanced human ER?-dependent transcriptional activation at concentrations ranging from 10-1000 nM. Finally, we employed an in silico computational model based upon the crystal structure for the human ER? ligand-binding domain complexed with E2 to structurally investigate binding of these putative ligands to human, mouse, and trout ER?. PFOA, PFNA, PFDA, and PFOS all efficiently docked with ER? from different species and formed a hydrogen bond at residue Arg394/398/407 (human/mouse/trout) in a manner similar to the environmental estrogens bisphenol A and nonylphenol. Overall, these data support the contention that several PFAAs are weak environmental xenoestrogens of potential concern. PMID:21163906

Benninghoff, Abby D; Bisson, William H; Koch, Daniel C; Ehresman, David J; Kolluri, Siva K; Williams, David E

2011-03-01

123

Design and chemical synthesis of iodine-containing molecules for application to solar-pumped I* lasers  

NASA Technical Reports Server (NTRS)

This work is directed toward the design and chemical synthesis of new media for solar-pumped I* lasers. In view of the desirability of preparing a perfluoroalkyl iodide absorbing strongly at 300 nm, the relationship betwen perfluoroalkyl iodide structure and the corresponding absorption wavelength was reexamined. Analysis of existing data suggests that, in this family of compounds, the absorption maximum shifts to longer wavelength, as desired, as the C-I bond in the lasant is progressively weakened. Weakening of the C-I bond correlates, in turn, with increasing stability of the perfluoroalkyl radical formed upon photodissociation of the iodide. The extremely promising absorption characteristics of perfluoro-tert-butyl iodide can be accounted for on this basis. A new technique of diode laser probing to obtain precise yields of I* atoms in photodissociation was also developed.

Shiner, C. S.

1985-01-01

124

Inhibition of human and rat 3?-hydroxysteroid dehydrogenase and 17?-hydroxysteroid dehydrogenase 3 activities by perfluoroalkylated substances  

Microsoft Academic Search

Perfluoroalkylated substances (PFASs) including perfluorooctane acid (PFOA) and perfluorooctane sulfonate (PFOS) have been classified as persistent organic pollutants and are known to cause reduced testosterone production in human males. The objective of the present study was to compare the potencies of five different PFASs including PFOA, PFOS, potassium perfluorooctane sulfonate (PFOSK), potassium perfluorohexane sulfonate (PFHxSK) and potassium perfluorobutane sulfonate (PFBSK)

Binghai Zhao; Guo-Xin Hu; Yanhui Chu; Xiudong Jin; Shouliang Gong; Benson T. Akingbemi; Zhiqiang Zhang; Barry R. Zirkin; Ren-Shan Ge

2010-01-01

125

Evaluating the additivity of perfluoroalkyl acids (PFAAs) in binary combinations on peroxisome proliferator-activated receptor-a(PPARa) activation  

EPA Science Inventory

Perfluoroalkyl acids (PFAAs) are found globally in the environment, detected in humans and wildlife, and are typically present as mixtures of PFAA congeners. Mechanistic studies have found that responses to PFAAs are mediated in part by PPARa. Our previous studies showed that ind...

126

Effect of Body Condition on Tissue Distribution of Perfluoroalkyl Substances (PFASs) in Arctic Fox (Vulpes lagopus).  

PubMed

Arctic animals undergo large seasonal fluctuations in body weight. The effect of body condition on the distribution and composition of 16 perfluoroalkyl substances (PFASs) was investigated in liver, blood, kidney, adipose tissue, and muscle of Arctic foxes (Vulpes lagopus) from Svalbard (n = 18, age 1-3 years). PFAS concentrations were generally highest in liver, followed by blood and kidney, while lowest concentrations were found in adipose tissue and muscle. Concentrations of summed perfluorocarboxylic acids and perfluoroalkyl sulfonates were five and seven times higher, respectively, in adipose tissue of lean compared to fat foxes. In addition, perfluorodecanoate (PFDA) and perfluoroheptanesulfonate (PFHpS) concentrations in liver, kidney, and blood, and, perfluorononanoate (PFNA) in liver and blood, were twice as high in the lean compared to the fat foxes. The ratio between perfluorooctane sulfonamide (FOSA) and its metabolite perfluorooctanesulfonate (PFOS) was lowest in liver, muscle, and kidney, while significantly higher proportions of FOSA were found in adipose tissue and blood. The results of the present study suggest that toxic potential of exposure to PFAS among other pollutants in Arctic mammals may increase during seasonal emaciation. The results also suggest that body condition should be taken into account when assessing temporal trends of PFASs. PMID:25215880

Aas, Camilla Bakken; Fuglei, Eva; Herzke, Dorte; Yoccoz, Nigel G; Routti, Heli

2014-10-01

127

Occurrence and transport of perfluoroalkyl acids (PFAAs), including short-chain PFAAs in Tangxun Lake, China.  

PubMed

Short-chain perfluoroalkyl acids (PFAAs), which have less than seven fluorinated carbons, have been introduced as substitutes for eight-carbon homologue products. In this study, water, sediment, and biological samples (fish and plant) were collected from Tangxun Lake, which is located near a production base of the fluorochemical industry in Wuhan, China. Perfluorobutane sulfonate (PFBS) and perfluorobutanoic acid (PFBA) were the predominant PFAAs in surface water, with average concentrations of 3660 ng/L and 4770 ng/L, respectively. However, perfluorooctane sulfonate (PFOS) was the most abundant PFAA in sediments, with an average concentration of 74.4 ng/g dw. The organic carbon normalized distribution coefficients (KOC) indicated that short-chain PFAAs (CF2 < 7) tended to have lower adsorption potentials than PFOS, perfluorooctanoic acid (PFOA), and longer perfluoroalkyl chain compounds. PFBS and PFBA could transport to a farther distance in the horizontal direction along the water flow and infiltrate into deeper depths in the vertical direction. However, levels of PFOS and PFOA in water dropped exponentially along the current, and their proportions were decreased gradually with the increasing depth in sediment cores. Furthermore, values of log bioconcentration factor (BCF) of the short-chain PFAAs were all relatively low (<1), indicating no bioaccumulation potentials for short-chain PFAAs in aquatic species. PMID:23883102

Zhou, Zhen; Liang, Yong; Shi, Yali; Xu, Lin; Cai, Yaqi

2013-08-20

128

Perfluoroalkyl sulfonates cause alkyl chain length-dependent hepatic steatosis and hypolipidemia mainly by impairing lipoprotein production in APOE*3-Leiden CETP mice.  

PubMed

Perfluorobutane sulfonate (PFBS), perfluorohexane sulfonate (PFHxS), and perfluorooctane sulfonate (PFOS) are stable perfluoroalkyl sulfonate (PFAS) surfactants, and PFHxS and PFOS are frequently detected in human biomonitoring studies. Some epidemiological studies have shown modest positive correlations of serum PFOS with non-high-density lipoprotein (HDL)-cholesterol (C). This study investigated the mechanism underlying the effect of PFAS surfactants on lipoprotein metabolism. APOE*3-Leiden.CETP mice were fed a Western-type diet with PFBS, PFHxS, or PFOS (30, 6, and 3 mg/kg/day, respectively) for 4-6 weeks. Whereas PFBS modestly reduced only plasma triglycerides (TG), PFHxS and PFOS markedly reduced TG, non-HDL-C, and HDL-C. The decrease in very low-density lipoprotein (VLDL) was caused by enhanced lipoprotein lipase-mediated VLDL-TG clearance and by decreased production of VLDL-TG and VLDL-apolipoprotein B. Reduced HDL production, related to decreased apolipoprotein AI synthesis, resulted in decreased HDL. PFHxS and PFOS increased liver weight and hepatic TG content. Hepatic gene expression profiling data indicated that these effects were the combined result of peroxisome proliferator-activated receptor alpha and pregnane X receptor activation. In conclusion, the potency of PFAS to affect lipoprotein metabolism increased with increasing alkyl chain length. PFHxS and PFOS reduce plasma TG and total cholesterol mainly by impairing lipoprotein production, implying that the reported positive correlations of serum PFOS and non-HDL-C are associative rather than causal. PMID:21705711

Bijland, Silvia; Rensen, Patrick C N; Pieterman, Elsbet J; Maas, Annemarie C E; van der Hoorn, José W; van Erk, Marjan J; Havekes, Louis M; Willems van Dijk, Ko; Chang, Shu-Ching; Ehresman, David J; Butenhoff, John L; Princen, Hans M G

2011-09-01

129

Design and chemical synthesis of iodine-containing molecules for application to solar-pumped I* lasers. Semiannual Progress Report, 1 January-30 June 1985  

SciTech Connect

This work is directed toward the design and chemical synthesis of new media for solar-pumped I* lasers. In view of the desirability of preparing a perfluoroalkyl iodide absorbing strongly at 300 nm, the relationship betwen perfluoroalkyl iodide structure and the corresponding absorption wavelength was reexamined. Analysis of existing data suggests that, in this family of compounds, the absorption maximum shifts to longer wavelength, as desired, as the C-I bond in the lasant is progressively weakened. Weakening of the C-I bond correlates, in turn, with increasing stability of the perfluoroalkyl radical formed upon photodissociation of the iodide. The extremely promising absorption characteristics of perfluoro-tert-butyl iodide can be accounted for on this basis. A new technique of diode laser probing to obtain precise yields of I* atoms in photodissociation was also developed.

Shiner, C.S.

1985-01-01

130

Surface chemical approach to single-step measurement of antibody in human serum using localized surface plasmon resonance biosensor on microtiter plate system.  

PubMed

In clinical settings, serum antibody levels serve as markers of pathology. For example, antibodies related to autoimmune diseases are among the conventional targets in laboratory tests. Simple clinical tests can improve the efficacy of laboratory practice. This study describes a single-step, wash-free technique for optically detecting antibodies in human serum through the localized surface plasmon resonance (LSPR) of gold nanoparticles. As a proof-of-concept experiment, the amount of antibiotin dissolved in human serum was measured with a LSPR-based biosensor in a wash-free manner using a conventional 96-well microtiter plate and a plate reader. For an efficient surface modification of biosensors, zwitterionic copolymer was used as a scaffold on the gold nanoparticle surface to immobilize antigen and blocking reagent. Single-step, wash-free measurement of antibiotin in human serum was successfully achieved. In addition, nonspecific responses from serum contents were significantly reduced because both the copolymer and hydrophilic antigen reagent that we employed were composed of poly(ethylene oxide) spacer. Comparative experiments of the antigen-antibody reaction in serum to that in buffered solution revealed that serum is a favorable environment for the biological reaction. In conclusion, our gold-nanoparticle-based LSPR method may provide a rapid and simple way to measure the amount of antibody in serum quantitatively in clinical practice. PMID:24770806

Yamamichi, Junta; Ojima, Tetsunori; Iida, Mie; Yurugi, Kimiko; Imamura, Takeshi; Ashihara, Eishi; Kimura, Shinya; Maekawa, Taira

2014-07-01

131

Levels and fate of perfluoroalkyl substances in beached plastic pellets and sediments collected from Greece.  

PubMed

Plastic debris damages marine wildlife and ecosystems becoming an important source of marine pollution. In addition, they can sorb, concentrate and stabilise contaminants acting as toxic carriers to the marine food web. In this context, the presence of 18 perfluoroalkyl substances (PFASs) in plastic pellets (n=5) and beach sediment (n=9) samples widely distributed around Greek coastal areas was assessed. The results, mainly, showed the sorption of PFASs onto pellet surface from surrounding water with concentrations from method limit of quantification to 115ng/kg for C5, C7, C8 and C10 carboxylic acids and C8 sulfonate acid. A similar pattern was found by comparing plastic pellets and sediment for the same sampling locations that could indicate a common origin of contamination in both types of samples. However, since the number of analysed samples is limited, a more comprehensive study with a higher number of samples should be performed in future research. PMID:25172614

Llorca, Marta; Farré, Marinella; Karapanagioti, Hrissi K; Barceló, Damià

2014-10-15

132

Comparison of yields of stable perfluoroalkyl radicals in gamma and neutron radiolysis  

SciTech Connect

In the irradiation of liquid perfluoro-1-methyl-4-isoburylcyclohexane (MBC) with Co-60 gamma rays, stable perfluoroalkyl radicals are formed. This paper shows the dependence on dose of the concentration of stable radicals formed during the irradiation of MBC with Co-60 gamma rays at 300 degrees K. The EPR spectra of these radicals show a doublet and a triplet with splitting at 3.9 and 5.6 mT, respectively. On the basis of perfluoro compounds like MBC it is possible to create dosimetric systems with which the dose of gamma-irradiation can be determined against a background stream of fast neutrons, simply by measuring the concentration of stabilized radicals.

Allayarov, S.R.; Barkalov, I.M.; Gol'danskii, V.I.; Zuev, A.P.

1985-09-01

133

Global emission inventories for C4-C14 perfluoroalkyl carboxylic acid (PFCA) homologues from 1951 to 2030, part II: the remaining pieces of the puzzle.  

PubMed

We identify eleven emission sources of perfluoroalkyl carboxylic acids (PFCAs) that have not been discussed in the past. These sources can be divided into three groups: [i] PFCAs released as ingredients or impurities, e.g., historical and current use of perfluorobutanoic acid (PFBA), perfluorohexanoic acid (PFHxA) and their derivatives; [ii] PFCAs formed as degradation products, e.g., atmospheric degradation of some hydrofluorocarbons (HFCs) and hydrofluoroethers (HFEs); and [iii] sources from which PFCAs are released as both impurities and degradation products, e.g., historical and current use of perfluorobutane sulfonyl fluoride (PBSF)- and perfluorohexane sulfonyl fluoride (PHxSF)-based products. Available information confirms that these sources were active in the past or are still active today, but due to a lack of information, it is not yet possible to quantify emissions from these sources. However, our review of the available information on these sources shows that some of the sources may have been significant in the past (e.g., the historical use of PFBA-, PFHxA-, PBSF- and PHxSF-based products), whereas others can be significant in the long-term (e.g., (bio)degradation of various side-chain fluorinated polymers where PFCA precursors are chemically bound to the backbone). In addition, we summarize critical knowledge and data gaps regarding these sources as a basis for future research. PMID:24861268

Wang, Zhanyun; Cousins, Ian T; Scheringer, Martin; Buck, Robert C; Hungerbühler, Konrad

2014-08-01

134

Occurrence of perfluoroalkyl compounds in surface waters from the North Pacific to the Arctic Ocean.  

PubMed

Perfluoroalkyl compounds (PFCs) were determined in 22 surface water samples (39-76°N) and three sea ice core and snow samples (77-87°N) collected from North Pacific to the Arctic Ocean during the fourth Chinese Arctic Expedition in 2010. Geographically, the average concentration of ?PFC in surface water samples were 560 ± 170 pg L(-1) for the Northwest Pacific Ocean, 500 ± 170 pg L(-1) for the Arctic Ocean, and 340 ± 130 pg L(-1) for the Bering Sea, respectively. The perfluoroalkyl carboxylates (PFCAs) were the dominant PFC class in the water samples, however, the spatial pattern of PFCs varied. The C(5), C(7) and C(8) PFCAs (i.e., perfluoropentanoate (PFPA), perfluoroheptanoate (PFHpA), and perfluorooctanoate (PFOA)) were the dominant PFCs in the Northwest Pacific Ocean while in the Bering Sea the PFPA dominated. The changing in the pattern and concentrations in Pacific Ocean indicate that the PFCs in surface water were influenced by sources from the East-Asian (such as Japan and China) and North American coast, and dilution effect during their transport to the Arctic. The presence of PFCs in the snow and ice core samples indicates an atmospheric deposition of PFCs in the Arctic. The elevated PFC concentration in the Arctic Ocean shows that the ice melting had an impact on the PFC levels and distribution. In addition, the C(4) and C(5) PFCAs (i.e., perfluorobutanoate (PFBA), PFPA) became the dominant PFCs in the Arctic Ocean indicating that PFBA is a marker for sea ice melting as the source of exposure. PMID:22128794

Cai, Minghong; Zhao, Zhen; Yin, Zhigao; Ahrens, Lutz; Huang, Peng; Cai, Minggang; Yang, Haizhen; He, Jianfeng; Sturm, Renate; Ebinghaus, Ralf; Xie, Zhiyong

2012-01-17

135

Investigating sources and pathways of perfluoroalkyl acids (PFAAs) in aquifers in Tokyo using multiple tracers.  

PubMed

We employed a multi-tracer approach to investigate sources and pathways of perfluoroalkyl acids (PFAAs) in urban groundwater, based on 53 groundwater samples taken from confined aquifers and unconfined aquifers in Tokyo. While the median concentrations of groundwater PFAAs were several ng/L, the maximum concentrations of perfluorooctane sulfonate (PFOS, 990 ng/L), perfluorooctanoate (PFOA, 1800 ng/L) and perfluorononanoate (PFNA, 620 ng/L) in groundwater were several times higher than those of wastewater and street runoff reported in the literature. PFAAs were more frequently detected than sewage tracers (carbamazepine and crotamiton), presumably owing to the higher persistence of PFAAs, the multiple sources of PFAAs beyond sewage (e.g., surface runoff, point sources) and the formation of PFAAs from their precursors. Use of multiple methods of source apportionment including principal component analysis-multiple linear regression (PCA-MLR) and perfluoroalkyl carboxylic acid ratio analysis highlighted sewage and point sources as the primary sources of PFAAs in the most severely polluted groundwater samples, with street runoff being a minor source (44.6% sewage, 45.7% point sources and 9.7% street runoff, by PCA-MLR). Tritium analysis indicated that, while young groundwater (recharged during or after the 1970s, when PFAAs were already in commercial use) in shallow aquifers (<50 m depth) was naturally highly vulnerable to PFAA pollution, PFAAs were also found in old groundwater (recharged before the 1950s, when PFAAs were not in use) in deep aquifers (50-500 m depth). This study demonstrated the utility of multiple uses of tracers (pharmaceuticals and personal care products; PPCPs, tritium) and source apportionment methods in investigating sources and pathways of PFAAs in multiple aquifer systems. PMID:24814036

Kuroda, Keisuke; Murakami, Michio; Oguma, Kumiko; Takada, Hideshige; Takizawa, Satoshi

2014-08-01

136

Biomonitoring of perfluoroalkyl acids in human urine and estimates of biological half-life.  

PubMed

Perfluoroalkyl acids (PFAAs) are persistent and bioaccumulative compounds that have been associated with adverse health outcomes. In human blood, PFAAs exist as both linear and branched isomers, yet for most linear homologues, and for all branched isomers, elimination rates are unknown. Paired blood and urine samples (n = 86) were collected from adults in China. They were analyzed by a sensitive isomer-specific method that permitted the detection of many PFAAs in human urine for the first time. For all PFAAs except perfluoroundecanoate (PFUnA), levels in urine correlated positively with levels in blood. Perfluoroalkyl carboxylates (PFCAs) were excreted more efficiently than perfluoroalkane sulfonates (PFSAs) of the same carbon chain-length. In general, shorter PFCAs were excreted more efficiently than longer ones, but for PFSAs, perfluorooctanesulfonate (PFOS, a C8 compound) was excreted more efficiently than perfluorohexanesulfonate (PFHxS, a C6 compound). Among PFOS and perfluorooctanoate (PFOA) isomers, major branched isomers were more efficiently excreted than the corresponding linear isomer. A one-compartment model was used to estimate the biological elimination half-lives of PFAAs. Among all PFAAs, the estimated arithmetic mean elimination half-lives ranged from 0.5 ± 0.1 years (for one branched PFOA isomer, 5m-PFOA) to 90 ± 11 years (for one branched PFOS isomer, 1m-PFOS). Urinary excretion was the major elimination route for short PFCAs (C ? 8), but for longer PFCAs, PFOS and PFHxS, other routes of excretion likely contribute to overall elimination. Urinary concentrations are good biomarkers of the internal dose, and this less invasive strategy can therefore be used in future epidemiological and biomonitoring studies. The very long half-lives of long-chain PFCAs, PFHxS, and PFOS isomers in humans stress the importance of global and domestic exposure mitigation strategies. PMID:23980546

Zhang, Yifeng; Beesoon, Sanjay; Zhu, Lingyan; Martin, Jonathan W

2013-09-17

137

Pre-natal exposure to perfluoroalkyl substances may be associated with altered vaccine antibody levels and immune-related health outcomes in early childhood.  

PubMed

Perfluoroalkyl substances (PFAS) are suggested to have immunosuppressive effects; exposure in utero and in the first years of life is of special concern as fetuses and small children are highly vulnerable to toxicant exposure. The objective of this study was to investigate the effect of pre-natal exposure to PFAS on responses to pediatric vaccines and immune-related health outcomes in children up to 3 years of age. In the prospective birth-cohort BraMat, a sub-cohort of the Norwegian Mother and Child Cohort Study (MoBa), pregnant women from Oslo and Akershus, Norway, were recruited during 2007-2008. Three annual questionnaire-based follow-ups were performed. Blood samples were collected from the mothers at the time of delivery and from the children at the age of 3 years. As a measure of pre-natal exposure to PFAS, the concentrations of perfluorooctanoate (PFOA), perfluorononanoate (PFNA), perfluorohexane sulfonate (PFHxS), and perfluorooctane sulfonate (PFOS) were determined in maternal blood from 99 BraMat participants. Main outcome measures were anti-vaccine antibody levels, common infectious diseases and allergy- and asthma-related health outcomes in the children up to the age of 3 years. There was an inverse association between the level of anti-rubella antibodies in the children's serum at age 3 years and the concentrations of the four PFAS. Furthermore, there was a positive association between the maternal concentrations of PFOA and PFNA and the number of episodes of common cold for the children, and between PFOA and PFHxS and the number of episodes of gastroenteritis. No associations were found between maternal PFAS concentrations and the allergy- and asthma-related health outcomes investigated. The results indicate that pre-natal exposure to PFAS may be associated with immunosuppression in early childhood. PMID:23350954

Granum, Berit; Haug, Line S; Namork, Ellen; Stølevik, Solvor B; Thomsen, Cathrine; Aaberge, Ingeborg S; van Loveren, Henk; Løvik, Martinus; Nygaard, Unni C

2013-01-01

138

Circulating Mitochondrial DNA as Biomarker Linking Environmental Chemical Exposure to Early Preclinical Lesions Elevation of mtDNA in Human Serum after Exposure to Carcinogenic Halo-Alkane-Based Pesticides  

PubMed Central

There is a need for a panel of suitable biomarkers for detection of environmental chemical exposure leading to the initiation or progression of degenerative diseases or potentially, to cancer. As the peripheral blood may contain increased levels of circulating cell-free DNA in diseased individuals, we aimed to evaluate this DNA as effect biomarker recognizing vulnerability after exposure to environmental chemicals. We recruited 164 individuals presumably exposed to halo-alkane-based pesticides. Exposure evaluation was based on human biomonitoring analysis; as biomarker of exposure parent halo-methanes, -ethanes and their metabolites, as well as the hemoglobin-adducts methyl valine and hydroxyl ethyl valine in blood were used, complemented by expert evaluation of exposure and clinical intoxication symptoms as well as a questionnaire. Assessment showed exposures to halo alkanes in the concentration range being higher than non-cancer reference doses (RfD) but (mostly) lower than the occupational exposure limits. We quantified circulating DNA in serum from 86 individuals with confirmed exposure to off-gassing halo-alkane pesticides (in storage facilities or in home environment) and 30 non-exposed controls, and found that exposure was significantly associated with elevated serum levels of circulating mitochondrial DNA (in size of 79 bp, mtDNA-79, p?=?0.0001). The decreased integrity of mtDNA (mtDNA-230/mtDNA-79) in exposed individuals implicates apoptotic processes (p?=?0.015). The relative amounts of mtDNA-79 in serum were positively associated with the lag-time after intoxication to these chemicals (r?=?0.99, p<0.0001). Several months of post-exposure the specificity of this biomarker increased from 30% to 97% in patients with intoxication symptoms. Our findings indicate that mitochondrial DNA has a potential to serve as a biomarker recognizing vulnerable risk groups after exposure to toxic/carcinogenic chemicals. PMID:23741329

Budnik, Lygia T.; Kloth, Stefan; Baur, Xaver; Preisser, Alexandra M.; Schwarzenbach, Heidi

2013-01-01

139

Spatial distribution of perfluoroalkyl contaminants in lake trout from the Great Lakes.  

PubMed

Individual whole body homogenates of 4 year old lake trout (Salvelinus namaycush) samples collected in 2001 from each of the Great Lakes were extracted using a novel fluorophilicity cleanup step and analyzed for perfluoroalkyl compounds (PFCs). Standard addition and internal standardization were used for quantification. Results were reported (+/- SE) for perfluorinated carboxylates (PFCAs), perfluorinated sulfonates (PFSAs), and unsaturated fluorotelomer carboxylates (8:2 and 10:2 FTUCA). The lowest average concentration of sigmaPFC was found in samples from Lake Superior (13+/-1 ng g(-1)), while the highest average concentration was found in samples from Lake Erie (152+/-14 ng g(-1)). Samples from Lake Ontario (60+/-5 ng g(-1)) and Lake Huron (58 +/-10 ng g(-1)) showed similar average sigmaPFC concentrations, although the perfluorinated sulfonate/carboxylate ratios were different. The major perfluoroalkyl contaminant observed was perfluorooctane sulfonate (PFOS) with the highest concentration found in samples from Lake Erie (121+/-14 ng g(-1)), followed by samples from Lake Ontario (46+/-5 ng g(-1)), Lake Huron (39 +/-10 ng g(-1)), Lake Michigan (16+/-3 ng g(-1)), and Lake Superior (5+/-1 ng g(-1)). Perfluorodecane sulfonate (PFDS) was detected in 89% of the samples, with the highest concentration in Lake Erie samples (9.8+/-1.6 ng g(-1)), and lowest concentration in samples from Lake Superior (0.7 +/- 0.1 ng g(-1)). Statistically significant correlations were observed between PFOS and PFDS concentrations, and PFOS concentration and body weight, respectively. The PFCAs were detected in all samples, with the highest total average concentration in samples from Lake Erie (19 ng g(-1)), followed by samples from Lake Huron (16 ng g(-1)), Lake Ontario (10 ng g(-1)), Lake Michigan (9 ng g(-1)) and Lake Superior (7 ng g(-1)). The compounds with significant contributions to the sigmaPFCA concentrations were PFOA and C9-C13-PFCAs. The 8:2 FTUCA was detected at concentrations ranging between 0.1 and 0.2 ng g-1, with the highest level in samples showing also elevated concentrations of PFOA (4.4 ng g(-1) for Lake Michigan vs 1.5 ng g(-1) for all other samples). The 10:2 FTUCA was detected only in 9% of all samples (nd, 45 pg g(-1)). For those PFCs where we determined lake water concentrations, the highest log BAFs were calculated for PFOS (4.1), PFDA (3.9), and PFOSA (3.8). PMID:17396640

Furdui, Vasile I; Stock, Naomi L; Ellis, David A; Butt, Craig M; Whittle, D Michael; Crozier, Patrick W; Reiner, Eric J; Muir, Derek C G; Mabury, Scott A

2007-03-01

140

Investigation of the excited state iodine lifetime in the photodissociation of perfluoroalkyl iodides  

NASA Technical Reports Server (NTRS)

An evaluation of prospective laser materials for a space-based solar pumped laser system over the past decade has resulted in the identification of the iodine photodissociation laser as that system best suited to solar-pumped high energy operation. The active medium for the solar-pumped iodine photodissociation laser is from the family of perfluoroalkyl iodides. These lasants have the general form C(n)F(2n + 1)I, often abbreviated as RI. These iodides are known to exhibit photodissociaiton of the C-I bond when irradiated by near UV photons. The focus was on the experimental determination of the lifetime of the excited iodine atom following photodissociation of C4F9I, and also to monitor fluorescence from the iodine molecule at 500 nm to determine if I2 is being produced in the process. Photodissociation is achieved using an XeCl excimer laser with an output wavelength of 308 nm. The XeCl beam is focused into the middle of a cylindrical quartz cell containing the lasant. The laser pulse is detected with a fast risetime photomultiplier tube as it exits the cell. Other aspects of the investigation are discussed.

Cobb, Stephen H.

1991-01-01

141

Exposure and effects of perfluoroalkyl substances in tree swallows nesting in Minnesota and Wisconsin, USA.  

PubMed

The exposure and effects of perfluoroalkyl substances (PFASs) were studied at eight locations in Minnesota and Wisconsin between 2007 and 2011 using tree swallows (Tachycineta bicolor). Concentrations of PFASs were quantified as were reproductive success end points. The sample egg method was used wherein an egg sample is collected, and the hatching success of the remaining eggs in the nest is assessed. The association between PFAS exposure and reproductive success was assessed by site comparisons, logistic regression analysis, and multistate modeling, a technique not previously used in this context. There was a negative association between concentrations of perfluorooctane sulfonate (PFOS) in eggs and hatching success. The concentration at which effects became evident (150-200 ng/g wet weight) was far lower than effect levels found in laboratory feeding trials or egg-injection studies of other avian species. This discrepancy was likely because behavioral effects and other extrinsic factors are not accounted for in these laboratory studies and the possibility that tree swallows are unusually sensitive to PFASs. The results from multistate modeling and simple logistic regression analyses were nearly identical. Multistate modeling provides a better method to examine possible effects of additional covariates and assessment of models using Akaike information criteria analyses. There was a credible association between PFOS concentrations in plasma and eggs, so extrapolation between these two commonly sampled tissues can be performed. PMID:23860575

Custer, Christine M; Custer, Thomas W; Dummer, Paul M; Etterson, Matthew A; Thogmartin, Wayne E; Wu, Qian; Kannan, Kurunthachalam; Trowbridge, Annette; McKann, Patrick C

2014-01-01

142

Perfluoroalkyl contaminants in plasma of five sea turtle species: comparisons in concentration and potential health risks.  

PubMed

The authors compared blood plasma concentrations of 13 perfluoroalkyl contaminants (PFCs) in five sea turtle species with differing trophic levels. Wild sea turtles were blood sampled from the southeastern region of the United States, and plasma was analyzed using liquid chromatography tandem mass spectrometry. Mean concentrations of perfluorooctane sulfonate (PFOS), the predominant PFC, increased with trophic level from herbivorous greens (2.41 ng/g), jellyfish-eating leatherbacks (3.95 ng/g), omnivorous loggerheads (6.47 ng/g), to crab-eating Kemp's ridleys (15.7 ng/g). However, spongivorous hawksbills had surprisingly high concentrations of PFOS (11.9 ng/g) and other PFCs based on their trophic level. These baseline concentrations of biomagnifying PFCs demonstrate interesting species and geographical differences. The measured PFOS concentrations were compared with concentrations known to cause toxic effects in laboratory animals, and estimated margins of safety (EMOS) were calculated. Small EMOS (<100), suggestive of potential risk of adverse health effects, were observed for all five sea turtle species for immunosuppression. Estimated margins of safety less than 100 were also observed for liver, thyroid, and neurobehavorial effects for the more highly exposed species. These baseline concentrations and the preliminary EMOS exercise provide a better understanding of the potential health risks of PFCs for conservation managers to protect these threatened and endangered species. PMID:22447337

Keller, Jennifer M; Ngai, Lily; Braun McNeill, Joanne; Wood, Lawrence D; Stewart, Kelly R; O'Connell, Steven G; Kucklick, John R

2012-06-01

143

Quantifying diffuse and point inputs of perfluoroalkyl acids in a nonindustrial river catchment.  

PubMed

Recently, the role of diffuse inputs of perfluoroalkyl acids (PFAAs) into surface waters has been investigated. It has been observed that river loads increased during rain and that street runoff contained considerable loads of PFAAs. This study aims at quantifying these diffuse inputs and identifying the initial sources in a small nonindustrial river catchment. The river was sampled in three distinct subcatchments (rural, urban, and wastewater treatment plant) at high temporal resolution during two rain events and samples were analyzed for perfluorocarboxylates and perfluorosulfonates. Additionally, rain, stormwater runoff, wastewater effluent, and drinking water were sampled. PFAA concentrations in river water were all low (e.g., < 10 ng/L for perfluorooctanoate, PFOA), but increased during rainfall. PFAA concentrations and water discharge data were integrated into a mass balance assessment that shows that 30-60% of PFAA loads can be attributed to diffuse inputs. Rain contributed 10-50% of the overall loads, mobilization of dry deposition and outdoor release of PFAA from products with 20-60%. We estimated that within a year 2.5-5 g of PFOA originating from rain and surface runoff are emitted into this small catchment (6 km(2), 12,500 persons). PMID:22035097

Müller, Claudia E; Spiess, Nora; Gerecke, Andreas C; Scheringer, Martin; Hungerbühler, Konrad

2011-12-01

144

Perfluoroalkyl acid contamination and polyunsaturated fatty acid composition of French freshwater and marine fishes.  

PubMed

In this study, French marine and freshwater fish perfluoroalkyl acid (PFAA) contamination are presented along with their fatty acid (FA) composition to provide further elements for a risk/benefit balance of fish consumption to be assessed. The 29 most consumed marine fish species were collected in four metropolitan French coastal areas in 2004 to constitute composite samples. Geographical differences in terms of consumed species and contamination level were taken into account. Three hundred and eighty-seven composite samples corresponding to 16 freshwater fish species collected between 2008 and 2010 in the six major French rivers or their tributaries were selected among the French national agency for water and aquatic environments freshwater fish sample library. The raw edible parts were analyzed for FA composition and PFAA contamination. Results show that freshwater fishes are more contaminated by PFAAs than marine fishes and do not share the same contamination profile. Freshwater fish contamination is mostly driven by perfluorooctane sulfonate (PFOS) (75%), whereas marine fish contamination is split between perfluorooctanoic acid (PFOA) (24%), PFOS (20%), perfluorohexanoic acid (PFHxA) (15%), perfluoropentanoic acid (PFHpA) (11%), and perfluorobutanoic acid (PFBA) (11%). Common carp, pike-perch, European perch, thicklip grey mullet, and common roach presented the most unfavorable balance profile due to their high level of PFAAs and low level of n-3 long-chain polyunsaturated fatty acids (LC-PUFAs). These data could be used, if needed, in an updated opinion on fish consumption that takes into account PFAA contamination. PMID:25004121

Yamada, Ami; Bemrah, Nawel; Veyrand, Bruno; Pollono, Charles; Merlo, Mathilde; Desvignes, Virginie; Sirot, Véronique; Oseredczuk, Marine; Marchand, Philippe; Cariou, Ronan; Antignac, Jean-Phillippe; Le Bizec, Bruno; Leblanc, Jean-Charles

2014-07-30

145

Perfluoroalkyl substances in soils around the Nepali Koshi River: levels, distribution, and mass balance.  

PubMed

Perfluoroalkyl substances (PFASs) were analyzed in surface soils along the Koshi River in Nepal, a typical agricultural country with little industrialization and urbanization. Sixteen target PFASs were quantified in soils from a hilly region in central and eastern Nepal, but only ten PFASs were detected. Concentrations of total PFASs ranged from nd (below the detection limit) to 1.78 ng/g dw. The predominant PFASs in soils were perfluoro-octanoic acid (PFOA) and perfluoro-butanesulfonate (PFBS) with concentrations that ranged from nd to 0.26 ng/g dw and nd to 0.38 ng/g dw, respectively. Results of mass balance analysis also revealed weak associations among concentrations of PFASs, extractable organic fluorine (EOF), and total fluorine (TF). PFASs were relatively evenly distributed among locations. Due to the absence of direct emission of PFASs and slow development of local industry, PFASs in soils originated mostly from long-range atmospheric transport, consumer use, and disposal of PFASs-containing products. Uncontrolled disposal of domestic waste will be a challenge to controlling concentrations of PFASs in Nepal. PMID:24705951

Tan, Bing; Wang, Tieyu; Wang, Pei; Luo, Wei; Lu, Yonglong; Romesh, Kumar Y; Giesy, John P

2014-08-01

146

Micropatterning of perfluoroalkyl self-assembled monolayers for arraying proteins and cells on chips  

NASA Astrophysics Data System (ADS)

Organosilane self-assembled monolayers (SAMs) with perfluoroalkyl groups ( Rf) on glass surfaces were used for arraying proteins and cells on chips. Quartz crystal microbalance measurements confirmed the inhibition of protein adsorption on Rf-SAM-modified surfaces and showed efficient adsorption on hydroxyl-, carboxyl-, and amino group-modified surfaces. The characteristics of Rf-modified surfaces were evaluated using solvent contact angle measurement and Fourier transform infrared (FTIR) spectroscopy. The Rf surface was highly water- and oil-resistant, as inferred from the contact angles of water, oleic acid, and hexadecane. Specific peaks of IR spectra were detected in the region from 1160 to 1360 cm -1. Etching with dry plasma completely exfoliated the Rf-SAM, exposing the underlying intact glass surface. Modification conditions were optimized using contact angle and FTIR measurements. After dry plasma processing, the contact angles of all solvents became undetectable, and the IR peaks disappeared. Micrometer scale protein and cell patterns can be fabricated using the proposed method. Protein adsorption on micropatterned Rf-SAM-modified chips was evaluated using fluorescence analysis; protein adsorption was easily controlled by patterning Rf-SAM. PC12 and HeLa cells grew well on micropatterned Rf-SAM-modified chips. Micropatterning of Rf-SAM by dry plasma treatment with photolithography is useful for the spatial arrangement of proteins and cells.

Kira, Atsushi; Okano, Kazunori; Hosokawa, Yoichiroh; Naito, Akira; Fuwa, Koh; Yuyama, Jyunpei; Masuhara, Hiroshi

2009-06-01

147

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) in mineral water and tap water.  

PubMed

The aims of the present study were to determine PFAS (perfluoroalkyl and polyfluoroalkyl substances) concentrations in various sources of water intended for human consumption, use these data to calculate the possible uptake via water as well as to estimate the water related health risk to consumers. A total of 177 water samples (119 mineral waters, 26 tap water samples, 18 spring water samples and 14 raw (untreated) water samples) were analyzed using liquid chromatography tandem mass spectrometry for the presence of 10 or 19 PFASs, respectively. PFAS concentrations above the limit of detection of 1 ng/L were found in 52% of all samples. Short-chain PFASs with less than 8 carbon atoms were responsible for 58% of the total PFAS contamination. The highest concentration (sum of PFASs) of 42.7 ng/L was detected in tap water. The calculated maximum uptake of both components for which a tolerable daily intake (TDI) level exists were 0.17 ng/kg bodyweight/day for PFOS (perfluorooctane sulfonic acid) and 0.21 ng/kg bodyweight/day for PFOA (perfluorooctane carboxylic acid). In regard to the model calculations made here (TDI for adults and for infants), the uptake of PFOS and PFOA via consumption of water can be considered negligible. Supplemental materials are available for this article. Go to the publisher's online edition of Journal of Environmental Science and Health, Part A to view the supplemental file. PMID:23043333

Gellrich, Vanessa; Brunn, Hubertus; Stahl, Thorsten

2013-01-01

148

Temporal variations of perfluoroalkyl substances and polybrominated diphenyl ethers in alpine snow.  

PubMed

The occurrence and temporal variation of 18 perfluoroalkyl substances (PFASs) and 8 polybrominated diphenyl ethers (PBDEs) in the European Alps was investigated in a 10 m shallow firn core from Colle Gnifetti in the Monte Rosa Massif (4455 m above sea level). The firn core encompasses the years 1997-2007. Firn core sections were analyzed by liquid chromatography-tandem mass spectrometry (PFASs) and gas chromatography-mass spectrometry (PBDEs). We detected 12 PFASs and 8 PBDEs in the firn samples. Perfluorobutanoic acid (PFBA; 0.3-1.8 ng L(-1)) and perfluorooctanoic acid (PFOA; 0.2-0.6 ng L(-1)) were the major PFASs while BDE 99 (

Kirchgeorg, Torben; Dreyer, Annekatrin; Gabrieli, Jacopo; Kehrwald, Natalie; Sigl, Michael; Schwikowski, Margit; Boutron, Claude; Gambaro, Andrea; Barbante, Carlo; Ebinghaus, Ralf

2013-07-01

149

Effects of perfluoroalkyl acids on the function of the thyroid hormone and the aryl hydrocarbon receptor.  

PubMed

Perfluoroalkyl acids (PFAAs) are perfluorinated compounds that widely exist in the environment and can elicit adverse effects including endocrine disruption in humans and animals. This study investigated the effect of seven PFAAs on the thyroid hormone (TH) system assessing the proliferation of the 3,3',5-triiodo-L-thryonine (T3)-dependent rat pituitary GH3 cells using the T-screen assay and the effect on the aryl hydrocarbon receptor (AhR) transactivation in the AhR-luciferase reporter gene bioassay. A dose-dependent impact on GH3 cells was observed in the range 1×10(-9)-1×10(-4) M: seven PFAAs (perfluorooctane sulfonate (PFOS), perfluorohexane sulfonate (PFHxS), perfluorooctanoic acid, perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnA), and perfluorododecanoic acid (PFDoA)) inhibited the GH3 cell growth, and four PFAAs (PFOS, PFHxS, PFNA, and PFUnA) antagonized the T3-induced GH3 cell proliferation. At the highest test concentration, PFHxS showed a further increase of the T3-induced GH3 growth. Among the seven tested PFAAs, only PFDoA and PFDA elicited an activating effect on the AhR. In conclusion, PFAAs possess in vitro endocrine-disrupting potential by interfering with TH and AhR functions, which need to be taken into consideration when assessing the impact on human health. PMID:23539207

Long, Manhai; Ghisari, Mandana; Bonefeld-Jørgensen, Eva Cecilie

2013-11-01

150

Perfluoroalkyl substances and extractable organic fluorine in surface sediments and cores from Lake Ontario.  

PubMed

Fourteen perfluoroalkyl substances (PFASs) including short-chain perfluorocarboxylates (PFCAs, C4-C6) and perfluoroalkane sulfonates (PFSAs, C4 and C6) were measured in surface sediment samples from 26 stations collected in 2008 and sediment core samples from three stations (Niagara, Mississauga, and Rochester basins) collected in 2006 in Lake Ontario. Perfluorooctanesulfonate (PFOS), perfluorooctanoate (PFOA), perfluorononanoate (PFNA), perfluorodecanoate (PFDA), and perfluoroundecanoate (PFUnDA) were detected in all 26 surface sediment samples, whereas perfluorohexane sulfonate (PFHxS), perfluorooctane sulfonamide (FOSA), perfluorododecanoate (PFDoDA) and perfluorobutanoate (PFBA) were detected in over 70% of the surface sediment samples. PFOS was detected in all of the sediment core samples (range: 0.492-30.1ngg(-1) d.w.) over the period 1952-2005. The C8 to C11 PFCAs, FOSA, and PFBA increased in early 1970s. An overall increasing trend in sediment PFAS concentrations/fluxes from older to more recently deposited sediments was evident in the three sediment cores. The known PFCAs and PFSAs accounted for 2-44% of the anionic fraction of the extractable organic fluorine in surface sediment, suggesting that a large proportion of fluorine in this fraction remained unknown. Sediment core samples collected from Niagara basin showed an increase in unidentified organic fluorine in recent years (1995-2006). These results suggest that the use and manufacture of fluorinated organic compounds other than known PFCAs and PFSAs has diversified and increased. PMID:23911339

Yeung, Leo W Y; De Silva, Amila O; Loi, Eva I H; Marvin, Chris H; Taniyasu, Sachi; Yamashita, Nobuyoshi; Mabury, Scott A; Muir, Derek C G; Lam, Paul K S

2013-09-01

151

Human dietary exposure to perfluoroalkyl substances in Catalonia, Spain. Temporal trend.  

PubMed

In this study, we assessed the levels of 18 perfluoroalkyl substances (PFASs) in the most widely consumed foodstuffs in Catalonia, Spain, as well as the total dietary intake of these compounds. Forty food items were analysed. Only perfluoropentanoic acid (PFPeA), perfluorohexadecanoic acid (PFHxDA) and perfluorooctanoicdecanoic acid (PFOcDA) were not detected in any sample. Perfluorooctane sulfonate (PFOS) was the compound found in the highest number of samples (33 out of 80), followed by perfluorooctanoic acid (PFOA), perfluoroheptanoic acid (PFHpA), perfluorohexane sulfonic acid (PFHxS), perfluorodecanoic acid (PFDA) and perfluorodecane sulfonic acid (PFDS). Fish and shellfish was the food group in which more PFASs were detected and where the highest PFAS concentrations were found. The highest dietary intakes corresponded to children, followed by male seniors, with values of 1787 and 1466ng/day, respectively. For any of the age/gender groups of the population, the Tolerable Daily Intakes (TDIs) recommended by the EFSA were not exceeded. In general terms, PFAS levels found in the current study are lower than the concentrations recently reported in other countries. PMID:22953896

Domingo, José L; Jogsten, Ingrid Ericson; Eriksson, Ulrika; Martorell, Isabel; Perelló, Gemma; Nadal, Martí; Bavel, Bert van

2012-12-01

152

Transport of perfluoroalkyl substances (PFAS) from an arctic glacier to downstream locations: implications for sources.  

PubMed

Perfluoroalkyl substances (PFAS) have been globally detected in various environmental matrices, yet their fate and transport to the Arctic is still unclear, especially for the European Arctic. In this study, concentrations of 17 PFAS were quantified in two ice cores (n=26), surface snow (n=9) and surface water samples (n=14) collected along a spatial gradient in Svalbard, Norway. Concentrations of selected ions (Na(+), SO4(2-), etc.) were also determined for tracing the origins and sources of PFAS. Perfluorobutanoate (PFBA), perfluorooctanoate (PFOA) and perfluorononanoate (PFNA) were the dominant compounds found in ice core samples. Taking PFOA, PFNA and perfluorooctane-sulfonate (PFOS) as examples, higher concentrations were detected in the middle layers of the ice cores representing the period of 1997-2000. Lower concentrations of C8-C12 perfluorocarboxylates (PFCAs) were detected in comparison with concentrations measured previously in an ice core from the Canadian Arctic, indicating that contamination levels in the European Arctic are lower. Average PFAS concentrations were found to be lower in surface snow and melted glacier water samples, while increased concentrations were observed in river water downstream near the coastal area. Perfluorohexanesulfonate (PFHxS) was detected in the downstream locations, but not in the glacier, suggesting existence of local sources of this compound. Long-range atmospheric transport of PFAS was the major deposition pathway for the glaciers, while local sources (e.g., skiing activities) were identified in the downstream locations. PMID:23376515

Kwok, Karen Y; Yamazaki, Eriko; Yamashita, Nobuyoshi; Taniyasu, Sachi; Murphy, Margaret B; Horii, Yuichi; Petrick, Gert; Kallerborn, Roland; Kannan, Kurunthachalam; Murano, Kentaro; Lam, Paul K S

2013-03-01

153

Exposure and effects of perfluoroalkyl substances in tree swallows nesting in Minnesota and Wisconsin, USA  

USGS Publications Warehouse

The exposure and effects of perfluoroalkyl substances (PFASs) were studied at eight locations in Minnesota and Wisconsin between 2007 and 2011 using tree swallows (Tachycineta bicolor). Concentrations of PFASs were quantified as were reproductive success end points. The sample egg method was used wherein an egg sample is collected, and the hatching success of the remaining eggs in the nest is assessed. The association between PFAS exposure and reproductive success was assessed by site comparisons, logistic regression analysis, and multistate modeling, a technique not previously used in this context. There was a negative association between concentrations of perfluorooctane sulfonate (PFOS) in eggs and hatching success. The concentration at which effects became evident (150–200 ng/g wet weight) was far lower than effect levels found in laboratory feeding trials or egg-injection studies of other avian species. This discrepancy was likely because behavioral effects and other extrinsic factors are not accounted for in these laboratory studies and the possibility that tree swallows are unusually sensitive to PFASs. The results from multistate modeling and simple logistic regression analyses were nearly identical. Multistate modeling provides a better method to examine possible effects of additional covariates and assessment of models using Akaike information criteria analyses. There was a credible association between PFOS concentrations in plasma and eggs, so extrapolation between these two commonly sampled tissues can be performed.

Custer, Christine M.; Custer, Thomas W.; Dummer, Paul; Etterson, Matthew A.; Thogmartin, Wayne E.; Qian Wu; Kannan, Kurunthachalam; Trowbridge, Annette; McKann, Patrick C.

2013-01-01

154

Input characterization of perfluoroalkyl substances in wastewater treatment plants: source discrimination by exploratory data analysis.  

PubMed

This paper presents a methodology based on multivariate data analysis for identifying input sources of perfluoroalkyl substances (PFASs) detected in 37 wastewater treatment plants (WWTPs) across more than 40 cities in the state of Minnesota (USA). Exploratory analysis of data points has been carried out by unsupervised pattern recognition (cluster analysis), correlation analysis, ANOVA and per capita discharges in an attempt to discriminate sources of PFASs in WWTPs. Robust cluster solutions grouped the database according to the different PFAS profiles in WWTP influent. Significantly elevated levels of perfluorohexanoic acid (PFHxA), perfluorooctanoic acid (PFOA) and/or perfluorooctane sulfonate (PFOS) in influent have been found in 18 out of 37 WWTPs (49%). A substantial increase in the concentrations of PFHxA and/or PFOA from influent to effluent was observed in 59% of the WWTPs surveyed, suggestive of high concentration inputs of precursors. The fate of one precursor (8:2 fluorotelomer alcohol) in WWTP was modeled based on fugacity analysis to understand the increasing effluent concentration. Furthermore, population-related emissions cannot wholly explain the occurrence and levels of PFASs in WWTPs. Unusually high influent levels of PFASs were observed in WWTPs located in specific industrial areas or where known contamination had taken place. Despite the restriction on the production/use of PFOA and PFOS, this paper demonstrates that wastewater from industrial activities is still a principal determinant of PFAS pollution in urban watersheds. PMID:22483712

Xiao, Feng; Halbach, Thomas R; Simcik, Matt F; Gulliver, John S

2012-06-01

155

Effect of the addition of 1-hexyl-2-(perfluoroalkyl)-1-iodoethenes on the stability and radiopacity of perfluorooctyl bromide emulsions  

Microsoft Academic Search

1-Hexyl-2-(perfluoroalkyl)-1-iodoethenes, CnF2n+1CH=CIC6H13(FnH6IE), with high biocompatibility and X-ray contrast ability, were investigated as additives and stabilizers in perfluorooctyl bromide (perflubron, PFOB)\\/egg yolk phospholipids (EYP) emulsions (90:4 w\\/v%), the fluorocarbon-based preparation presently best suited for diagnostic uses. These iodinated mixed fluorocarbon\\/hydrocarbon compounds, when used as additives in various amounts in PFOB emulsions (replacement of 3–30 w\\/v% of PFOB by FnH6IE), enhanced the

Véronique Sanchez; Jacques Greiner

1995-01-01

156

Partition of perfluoroalkyl substances (PFASs) in whole blood and plasma, assessed in maternal and umbilical cord samples from inhabitants of arctic Russia and Uzbekistan.  

PubMed

Perfluoroalkyl substances (PFASs) are ubiquitous in the environment world-wide. Our overall objective was to assess the exposure to PFASs experienced by delivering women and their new-borns in the industrial city of Norilsk (arctic Russia) and the rural Aral Sea region of Uzbekistan, with the secondary objective of evaluating the distribution of PFASs between blood cell and plasma fractions. Six PFASs were detected in every sample from Norilsk city with the plasma concentration sequence of: PFOS?PFOA>PFNA>FOSA>PFHxS>PFUnDA. In the Uzbekistani samples, only PFOS was reported above the MDL (0.08 ng/mL). The median plasma concentrations of PFOS of 11.0 ng/mL for the Norilsk mothers was comparable to that reported for western countries, while that for Uzbekistan was considerably lower (0.23 ng/mL). Apparent increases in the maternal-cord concentration ratios for both whole blood and plasma were evident with the length of the carbon chain for both the carboxylate and the sulfonate PFASs. The median value of this ratio for FOSA in plasma was the lowest, while that for whole blood was the highest. Other than for FOSA, the observed plasma-whole blood concentration ratios for maternal and umbilical cord blood were consistent with a priori calculations using appropriate packed cell and plasma volumes for neonates and pregnant women at term. Clearly FOSA favored whole blood, and acid-base equilibrium calculations suggested that the resonance-stabilized sulfonamidate ion resides in the blood cell fraction. Thus for PFASs and related compounds with pK values with magnitudes comparable to physiological pH, it is pertinent to measure the cell-associated fraction (separately or as whole blood). Our study illustrates that consideration of both the physico-chemical properties of the contaminants and the physiological attributes of blood matrices were helpful in the interpretation of our findings. PMID:23410865

Hanssen, Linda; Dudarev, Alexey A; Huber, Sandra; Odland, Jon Øyvind; Nieboer, Evert; Sandanger, Torkjel M

2013-03-01

157

A Comparison of RIA and LC-MS/MS Methods to Quantify Steroids in Rat Serum and Urine Following Exposure to an Endocrine Disrupting Chemical  

EPA Science Inventory

Commercially available radio immunoassays (RIM) are frequently used in toxicological studies to evaluate effects of endocrine disrupting chemicals (EDCs) on steroidogenesis in rats. Currently there are limited data comparing steroid concentrations in rats as measured by RIM to th...

158

Evaluation of additivity of binary mixtures of perfluoroalkyl acids (PFAAs) on peroxisome proliferator-activated receptor-alpha (PPARa) activation in vitro  

EPA Science Inventory

Perfluoroalkyl acids (PFAAs) are found globally in the environment and in animal tissues, and are present as mixtures of PFAA congeners. Mechanistic studies have found that in vivo effects of PFAAs are mediated by PPARL. Our previous studies showed that individual PFAAs activate ...

159

A targeted/non-targeted screening method for perfluoroalkyl carboxylic acids and sulfonates in whole fish using quadrupole time-of-flight mass spectrometry and MS(e).  

PubMed

A new method for measuring perfluoroalkyl contaminants (PFCs) in biological matrices has been developed. An ultra-high pressure liquid chromatograph equipped with a quadrupole time-of-flight mass spectrometer (UPLC-QToF) was optimized using a continuous precursor/product ion monitoring mode. Unlike traditional targeted studies that isolate precursor/product ion pairs, the current method alternates between two ionization energy channels to continuously capture standard electrospray ionization (low energy) and collision induced dissociation (high energy) spectra. The result is the indiscriminant acquisition of paired low and high energy spectra for all constituents eluting from the chromatographic system. This technique was evaluated for the routine analysis of perfluoroalkyl species. Using this technique, linear perfluoroalkyl carboxylic acids (C4 to C14) and perfluoroalkyl sulfonates (C4, C6, C8 and C10) exhibited a linear range spanning over three orders of magnitude and were detectable at levels less than 1 pg on column with a root mean squared signal to noise ratio of 5 to 20. Lake trout (Salvelinus namaycush) and National Institutes of Standards and Technology Standard Reference Material 1946 were used to evaluate matrix effects and the accuracy of this method when applied to a whole fish extract. The current method was also evaluated as a diagnostic tool to identify unknown PFCs using experimental fragmentation patterns, mass defect filtering and Kendrick plots. PMID:24352588

Crimmins, Bernard S; Xia, Xiaoyan; Hopke, Philip K; Holsen, Thomas M

2014-02-01

160

Activation of Mouse and Human Peroxisome Proliferator-Activated Receptor Alpha by Perfluoroalkyl Acids of Different Functional Groups and Chain Lengths  

Microsoft Academic Search

Perfluoroalkyl acids (PFAAs) are surfactants used in consumer products and persist in the environment. Some PFAAs elicit adverse effects on rodent development and survival. PFAAs can activate peroxisome proliferator2activated receptor alpha (PPARa )a nd may act via PPARa to produce some of their effects. This study evaluated the ability of numerous PFAAs to induce mouse and human PPARa activity in

Cynthia J. Wolf; Margy L. Takacs; Judith E. Schmid; Christopher Lau; Barbara D. Abbott

2008-01-01

161

Perfluoroalkyl sulfonic and carboxylic acids: A critical review of physicochemical properties, levels and patterns in waters and wastewaters, and treatment methods  

Microsoft Academic Search

Perfluorinated acids (PFAs) are an emerging class of environmental contaminants present in various environmental and biological matrices. Two major PFA subclasses are the perfluorinated sulfonic acids (PFSAs) and carboxylic acids (PFCAs). The physicochemical properties and partitioning behavior for the linear PFA members are poorly understood and widely debated. Even less is known about the numerous branched congeners with varying perfluoroalkyl

Sierra Rayne; Kaya Forest

2009-01-01

162

Spatial and vertical variations of perfluoroalkyl substances in sediments of the Haihe River, China.  

PubMed

The levels of six perfluoroalkyl substances (PFASs) in surface sediment and their vertical variations in dated sediment cores from the Haihe River were investigated; studied substances included perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorooctane sulfonate (PFOS), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnA), and perfluorododecanoic acid (PFDoA). Results showed that the total PFAS concentration in surface sediment ranged between 0.52 and 16.33 ng/g dry weight (dw) with an average of 3.47 ng/g dw, with PFOS and PFOA as the dominant PFASs. In general, the PFAS concentrations in the mainstream increased from the upper to the lower reaches, except that a drop occurred downstream of the Erdao dam. Although the PFASs in the sediment cores did not show a clear decreasing or increasing trend with depth, the three cores had a similar vertical variation. The PFAS levels were relatively low in the surface sediment, and reached the first high point at 8-20 cm as a result of the wide use of PFASs from 1990 to 2000. After that the PFAS levels decreased, and then increased to a second high point at about 40-48 cm, which might be caused by the leaching of PFASs in sediment. Because PFASs have hydrophilic groups and relatively high solubility, the PFASs will transfer from the upper to lower layers of sediment when water infiltration occurs, leading to the fluctuation of PFAS levels in sediment cores. This study suggests that both the temporal variation of sources and transfer processes of PFASs in sediments are important factors influencing the vertical variation of PFASs in sediment cores. PMID:25108711

Zhao, Xiuli; Xia, Xinghui; Zhang, Shangwei; Wu, Qiong; Wang, Xuejun

2014-08-01

163

Accumulation of perfluoroalkyl compounds in tibetan mountain snow: temporal patterns from 1980 to 2010.  

PubMed

The use of snow and ice cores as recorders of environmental contamination is particularly relevant for per- and polyfluoroalky substances (PFASs) given their production history, differing source regions and varied mechanisms driving their global distribution. In a unique study perfluoroalkyl acids (PFAAs) were analyzed in dated snow-cores obtained from high mountain glaciers on the Tibetan Plateau (TP). One snow core was obtained from the Mt Muztagata glacier (accumulation period of 1980-1999), located in western Tibet and a second core from Mt. Zuoqiupo (accumulation period: 1996-2007) located in southeastern Tibet, with fresh surface snow collected near Lake Namco in 2010 (southern Tibet). The higher concentrations of ?PFAAs were observed in the older Mt Muztagata core and dominated by perfluorooctanesulfonic acid (PFOS) (61.4-346 pg/L) and perfluorooctanoic acid (PFOA) (40.8-243 pg/L), whereas in the Mt Zuoqiupu core the concentrations were lower (e.g., PFOA: 37.8-183 pg/L) with PFOS below detection limits. These differences in PFAA concentrations and composition profile likely reflect the upwind sources affecting the respective sites (e.g., European/central Asian sources for Mt Muztagata and India sources for Mt Zuoqiupu). Perfluorobutanoic acid (PFBA) dominated the recent surface snowpack of Lake Namco which is mainly associated with India sources where the shorter chain volatile PFASs precursors predominate. The use of snow cores in different parts of Tibet provides useful recorders to examine the influence of different PFASs source regions and reflect changing PFAS production/use in the Northern Hemisphere. PMID:24320138

Wang, Xiaoping; Halsall, Crispin; Codling, Garry; Xie, Zhiyong; Xu, Baiqing; Zhao, Zhen; Xue, Yonggang; Ebinghaus, Ralf; Jones, Kevin C

2014-01-01

164

Bioaccumulation of perfluoroalkyl substances by Daphnia magna in water with different types and concentrations of protein.  

PubMed

Perfluoroalkyl substances (PFASs) are sometimes regarded as proteinophilic compounds, however, there is no research report about the effect of environmental protein on the bioaccumulation of PFASs in waters. In the present study we investigated influences of protein on the bioaccumulation of six kinds of PFASs by Daphnia magna in water; it included perfluorooctane sulfonate, perfluorooctanoic acid, perfluorononanoic acid, perfluorodecanoic acid, perfluoroundecanoic acid, and perfluorododecanoic acid. Two types of protein including bovine albumin from animal and soy peptone from plant were compared and the effects of protein concentration were investigated. Both types of protein at high concentrations (10 and 20 mg L(-1)) suppressed the bioaccumulation of PFASs. When protein concentration increased from 0 to 20 mg L(-1), the decreasing ratios of the PFAS body burden (35.3-52.9%) in Daphnia magna induced by bovine albumin were significantly higher than those (22.0-36.6%) by soy peptone. The dialysis bag experiment results showed that the binding of PFASs to protein followed the Freundlich isotherm, suggesting it is not a linear partitioning process but an adsorption-like process. The partition coefficients of PFASs between bovine albumin and water were higher compared to soy peptone; this resulted in higher reducing rates of freely dissolved concentrations of PFASs with increasing bovine albumin concentration, leading to a stronger suppression of PFAS bioaccumulation. However, the presence of both types of protein with a low concentration (1 mg L(-1)) enhanced the bioaccumulation of PFASs. Furthermore, the water-based bioaccumulation factor based on the freely dissolved concentrations of PFASs even increased with and the depuration rate constants of PFASs from Daphnia magna decreased with protein concentration, suggesting that protein would not only reduce the bioavailable concentrations and uptake rates of PFASs but also lower the elimination rates of PFASs in Daphnia magna. Because these two opposite effects would change with different protein concentrations in water, the net effect of protein on PFAS bioaccumulation would also vary with protein concentration. PMID:23968486

Xia, Xinghui; Rabearisoa, Andry H; Jiang, Xiaoman; Dai, Zhineng

2013-10-01

165

Distribution and fate of perfluoroalkyl substances in Mediterranean Spanish sewage treatment plants.  

PubMed

The concentrations of 21 perfluoroalkyl substances (PFASs: C4-C14, C16, C18 carboxylates, C4, C6-C8 and C10 sulfonates and C8 sulfonamide) were determined in influent, effluent and sludge from 16 different sewage treatment plants (STPs) located in the Ebro (6), Guadalquivir (5), Jucar (2) and Llobregat (3) Rivers, in two consecutive years (2010 and 2011). The analytes were extracted by solid phase extraction (SPE) and determined by Liquid Chromatography triple Quadrupole Mass Spectrometer (LC-QqQ-MS). All samples, except two sludges from Guadalquivir River STPs, were contaminated with at least one PFAS. Perfluorobutanoate (PFBA), perfluoropentanoate (PFPeA) and perfluorooctane sulfonate (L-PFOS) were the most frequently detected. The highest concentration in water was determined in 2010 in a Guadalquivir River STP (perfluorohexanoate, PFHxA: 5.60?gL(-1)) and, in 2011, in an Ebro River STP (perfluorobutane sulfonate, L-PFBS: 0.31?gL(-1)). In sludge samples, the maximum concentration in 2010 was 1.79?gg(-1)dry weight (dw) (L-PFOS, in a Llobregat River STP), and in 2011, 1.88?gg(-1)dw (PFBA, in one Guadalquivir River STP). High PFAS values in sludge could be related to positive removal efficiencies, and can be attributed to their adsorption. Distribution coefficients (Kd) were determined ranging between 0.32Lkg(-1) (perfluorohexane sulfonate, L-PFHxS) and 36.6 10(3)Lkg(-1) (PFBA). The total PFAS loads discharged into the basins showed high values for the Ebro River STPs (66.9gday(-1)) while in the others, the loads were between 3.97gday(-1), in the Jucar STPs, and 32.2gday(-1), in the Guadalquivir STPs. PMID:24342098

Campo, Julian; Masiá, Ana; Picó, Yolanda; Farré, Marinella; Barceló, Damià

2014-02-15

166

Association between thyroid profile and perfluoroalkyl acids: data from NHNAES 2007-2008.  

PubMed

The effect of six perfluoroalkyl acids (PFAAs), namely, perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorodecanoic acid (PFDE), perfluorohexane sulfonic acid (PFHxS), 2-(N-methyl-perfluorooctane sulfonamide) acetic acid (MPAH), and perfluorononanoic acid (PFNA) on the levels of six thyroid function variables, namely, thyroid stimulating hormone (TSH), free and total thyroxine (FT4, TT4), free and total triiodothyronine (FT3, TT3), and thyroglobulin (TGN) was evaluated. Data from National Health and Nutrition Examination Survey for the years 2007-2008 were used for this evaluation. TSH levels increased with increase in levels of PFOA (p<0.01). There were no statistically significant associations between the levels of FT3, and FT4 with the levels of any of the six PFAAs. Levels of TT3 were found to increase with the levels of PFOA (p=0.01) and TT4 levels were found to increase with increase in PFHxS levels (p<0.01). Males had statistically significantly higher levels of FT3 than females and females had statistically significantly higher levels of TT4 than males. As compared to non-Hispanics whites and Hispanics, non-Hispanic blacks had lower levels of TSH, FT3, TT3, and TT4 but Hispanics had the lowest levels of TGN. Age was negatively associated with FT3 and TT3 but positively associated with FT4 and TT4. Non-smokers had higher levels of TSH and TT4 than smokers and smokers had higher levels of FT3 and TGN than non-smokers. Iodine deficiency was associated with increased levels of TSH, TT3, TT4, and TGN. PMID:24053974

Jain, Ram B

2013-10-01

167

Spatial trends of perfluoroalkyl compounds in ringed seals (Phoca hispida) from the Canadian Arctic.  

PubMed

The present study examined spatial trends of perfluoroalkyl compounds (PFCs) in liver samples from 11 populations of ringed seals (Phoca hispida) in the Canadian Arctic from 2002 to 2005. Trophic position and relative carbon sources were compared by analyzing stable nitrogen and carbon isotopes in muscle samples. Geometric mean concentrations of total C9-C15 perfluorinated carboxylates (PFCAs) ranged from 8.8 to 84 ng/g wet weight, and C9-C11 PFCAs predominated. Perfluorooctane sulfonate was the dominant PFC measured, with concentrations ranging from 6.5 to 89 ng/g wet weight, contributing between 29 and 56% of the total PFC concentration. Overall, mean PFC concentrations were similar between populations, and differences were attributed largely to elevated levels in the Gjoa Haven (Rae Strait, central Canadian Arctic archipelago) and Inukjuak populations (eastern Hudson Bay) and to lower concentrations at Pangnirtung (Cumberland Sound, Baffin Island). Mean stable nitrogen isotope ratios (+/-95% confidence intervals) ranged from 14.7 per thousand (+/-0.3 per thousand) at Nain (Labrador) to 17.9 per thousand (+/-0.7 per thousand) at Gjoa Haven, suggesting that all populations were within the same trophic level. Stable carbon isotope ratios varied widely between the seal populations, ranging from -22.9 per thousand (+/-0.2 per thousand) at Gjoa Haven to -17.7 per thousand (+/-0.4 per thousand) at Nain. The delta13C ratios from Gjoa Haven were significantly more depleted than those for other populations and may suggest a terrestrially based carbon source. The depleted stable carbon isotope ratio may explain the elevated PFC concentrations in the Gjoa Haven population. Analysis of covariance indicated that delta13C was a significant covariable for seven of nine seal populations for which delta13C values were available. After adjusting for delta13C values, concentrations of most PFCs generally were statistically greater in the Grise Fiord, Qikiqtarjuaq, Arviat, and Nain populations. PMID:17988182

Butt, Craig M; Mabury, Scott A; Kwan, Michael; Wang, Xiaowa; Muir, Derek C G

2008-03-01

168

Trophic magnification and isomer fractionation of perfluoroalkyl substances in the food web of Taihu Lake, China.  

PubMed

Biomagnification of perfluoroalkyl substances (PFASs) are well studied in marine food webs, but related information in fresh water ecosystem and knowledge on fractionation of their isomers along the food web are limited. The distribution, bioaccumulation, magnification, and isomer fractionation of PFASs were investigated in a food web of Taihu Lake, China. Perfluorooctanesulfonate (PFOS) and perfluorocarboxylates (PFCAs) with longer carbon chain lengths, such as perfluorodecanoate (PFDA) and perfluoroundecanoate (PFUnA), were predominant in organisms, while perfluorohexanoate (PFHxA) and perfluorooctanoate (?PFOA) contributed more in the water phase. The consistent profile signature of PFOA isomers in water phase with 3M electrochemical fluorination (ECF) products suggests that ECF production of PFOA still exists in China. Linear proportions of PFOA, PFOS and perfluorooctane sulfonamide (PFOSA) in the biota were in the range of 91.9-100%, 78.6-95.5%, and 72.2-95.5%, respectively, indicating preferential bioaccumulation of linear isomers in biota. Trophic magnification factors (TMFs) were estimated for PFDA (2.43), perfluorododecanoate (PFDoA) (2.68) and PFOS (3.46) when all biota were included, suggesting that PFOS and long-chained PFCAs are biomagnified in the fresh water food web. The TMF of PFOS isomers descended in the order: n-PFOS (3.86) > 3+5m-PFOS (3.35) > 4m-PFOS (3.32) > 1m-PFOS (2.92) > m2-PFOS (2.67) > iso-PFOS (2.59), which is roughly identical to their elution order on a FluoroSep-RP Octyl column, suggesting that hydrophobicity may be an important contributor for isomer discrimination in biota. PMID:24460088

Fang, Shuhong; Chen, Xinwei; Zhao, Shuyan; Zhang, Yifeng; Jiang, Weiwei; Yang, Liping; Zhu, Lingyan

2014-02-18

169

Perfluoroalkyl acids in subarctic wild male mink (Neovison vison) in relation to age, season and geographical area.  

PubMed

This study investigates the influence of biological and environmental factors on the concentrations of perfluoroalkyl acids (PFAAs) in a top predator; the American mink. Perfluorobutane sulfonate (PFBS), perfluorohexane sulfonate (PFHxS), perfluorooctane sulfonate (PFOS) and perfluoroalkyl carboxylates (PFCAs) with C8-C13 perfluorinated carbon chains were analyzed in livers from wild male mink liver (n=101) from four areas in Sweden representing two inland environments (rural and highly anthropogenic, respectively) and two different coastal environments. Mean PFOS concentrations were 1250ng/g wet weight and some mink from the urban inland area had among the highest PFOS concentrations ever recorded in mink (up to 21 800ng/g wet weight). PFBS was detected in 89% of the samples, but in low concentrations (mean 0.6ng/g ww). There were significant differences in PFAA concentrations between the geographical areas (p<0.001-0.01). Age, body condition and body weight did not influence the concentrations significantly, but there was a seasonal influence on the concentrations of perfluorodecanoic acid (PFDA) and perfluoroundecanoic acid (PFUnDA) (p<0.01 and p<0.05, respectively), with lower concentrations in autumn samples than in samples taken in the winter and spring. It is thus recommended to take possible seasonal differences into account when using mink exposure data. The overall results suggest that the mink is a suitable sentinel species for assessing and monitoring environmental levels of PFAAs. PMID:23928036

Persson, Sara; Rotander, Anna; Kärrman, Anna; van Bavel, Bert; Magnusson, Ulf

2013-09-01

170

Probing the binding of an endocrine disrupting compound-Bisphenol F to human serum albumin: Insights into the interactions of harmful chemicals with functional biomacromolecules  

NASA Astrophysics Data System (ADS)

Bisphenol F (BPF) as an endocrine disrupting compounds (EDCs) pollutant in the environment poses a great threat to human health. To evaluate the toxicity of BPF at the protein level, the effects of BPF on human serum albumin (HSA) were investigated at three temperatures 283, 298, and 308 K by multiple spectroscopic techniques. The experimental results showed that BPF effectively quenched the intrinsic fluorescence of HSA via static quenching. The number of binding sites, the binding constant, the thermodynamic parameters and the binding subdomain were measured, and indicated that BPF could spontaneously bind with HSA on subdomain IIA through H-bond and van der Waals interactions. Furthermore, the conformation of HSA was demonstrably changed in the presence of BPF. The work provides accurate and full basic data for clarifying the binding mechanisms of BPF with HSA in vivo and is helpful for understanding its effect on protein function during its transportation and distribution in blood.

Pan, Fang; Xu, Tianci; Yang, Lijun; Jiang, Xiaoqing; Zhang, Lei

2014-11-01

171

Serum globulin electrophoresis  

MedlinePLUS

... levels of proteins called globulins in the fluid (serum) part of a blood sample. Other electrophoresis tests that measure proteins in the serum include: Immunoelectrophoresis Immunfixation Protein electrophoresis

172

Cholylglycine measured in serum by RIA and interleukin-1 beta determined by ELISA in differentiating viral hepatitis from chemical liver injury.  

PubMed

Serum bile acids have been shown to serve as useful indicators of liver disease. We have confirmed these findings and added an analysis of interleukin-1 beta (IL-1 beta) profiles to further differentiate viral hepatitis from toxic liver damage associated with exposure to vinyl chloride (VC) or trinitrotoluene (TNT). The frequency of elevated cholylglycine (CG) was 100%, 75%, and 37.5% in viral hepatitis, VC- and TNT-linked liver injury patients, respectively. The mean levels, expressed in micrograms/dL, were 578, 507, 142, and 65 in hepatitis B, hepatitis non-A non-B, VC and TNT liver injury patients, respectively. Thus, the CG test could detect viral hepatitis and, VC liver injury, and (less frequently) liver injury associated with exposure to TNT. The mean level of IL-1 beta in patients with hepatitis type B was 424 pg/mL and hepatitis non A non B was 384 pg/mL compared with a mean of 33-40 pg/mL in those with VC or TNT-linked liver disease. The IL-1 beta detection test proved further to be an important distinguishing parameter as it was 100% positive in patients with viral hepatitis but only 12.5% to 25% positive in patients with VC/TNT-induced liver damage. PMID:1447600

Li, G Y; Wang, T; Huggins, E M; Shams, N K; Davis, J F; Calkins, J H; Hornung, C A; Altekruse, J M; Sigel, M M

1992-09-01

173

Development of a method for quantitation of retinol and retinyl palmitate in human serum using high-performance liquid chromatography–atmospheric pressure chemical ionization–mass spectrometry  

Microsoft Academic Search

A method for the quantitative analysis of the vitamin A compounds all-trans-retinol and all-trans-retinyl palmitate was developed using high-performance liquid chromatography–atmospheric pressure chemical ionization–mass spectrometry (APCI–LC–MS). Unlike previous quantitative mass spectrometric methods for vitamin A, HPLC separations were carried out using a C30 reversed-phase column instead of GC separation. Because no sample hydrolysis or derivatization was necessary, retinyl palmitate was

Richard B van Breemen; Dejan Nikolic; Xiaoying Xu; Yansan Xiong; Machteld van Lieshout; Clive E West; Alexander B Schilling

1998-01-01

174

Serum and tumour ferritins in primary liver cancer  

Microsoft Academic Search

Serum ferritin concentrations were found to be raised, often considerably, in 58 of 76 black patients with primary liver cancer (PLC). No correlation could be demonstrated between the serum ferritin concentration and several other measurements, including the following: hepatic iron stores measured chemically, the size of the tumour, serum transaminase values, and the presence or absence of cirrhosis in the

M C Kew; J D Torrance; D Derman; M Simon; G M Macnab; R W Charlton; T H Bothwell

1978-01-01

175

Subsurface transport potential of perfluoroalkyl acids at aqueous film-forming foam (AFFF)-impacted sites.  

PubMed

Subsurface transport potential of a suite of perfluoroalkyl acids (PFAAs) was studied in batch sorption experiments with various soils and in the presence of co-contaminants relevant to aqueous film-forming foam (AFFF)-impacted sites. Specifically, PFAA sorption to multiple soils in the presence of nonaqueous phase liquid (NAPL) and nonfluorinated AFFF surfactants was examined. This study is the first to report on sorption of perfluorobutanoate (PFBA) and perfluoropentanoate (PFPeA) (log Koc = 1.88 and 1.37, respectively) and found that sorption of these compounds does not follow the chain-length dependent trend observed for longer chain-length PFAAs. Sorption of PFBA was similar to that of perfluorooctanoate (PFOA, log Koc = 1.89). NAPL and nonfluorinated AFFF surfactants all had varying impacts on sorption of longer chain (>6 CF2 groups) PFAAs. The primary impact of NAPL was observed in low foc soil (soil A) where Freundlich n-values increased when NAPL was present. Impacts of nonfluorinated AFFF surfactants varied with surfactant and soil. The anionic surfactant sodium decyl sulfate (SDS) illicited PFAA chain-length dependent impacts in two negatively charged soils with varying foc. In soil A, Kd values for perfluoroheptanoate (PFHpA) increased 91% with SDS, whereas values for perfluorodecanoate (PFDA) increased only 28%. An amphoteric surfactant, n,n-dimethyldodecylamine n-oxide (AO), had the most notable impact on PFAA sorption to a positively charged soil (soil C). In this soil, AO oxide significantly increased sorption for the longer chain PFAAs (i.e., 528% increase in Kd for PFDA). Changes in sorption caused by SDS and AO may be due to mixed hemimicelle formation, competitive sorption, or changes to PFAA solubility. Short-chain PFAA behavior in the presence of NAPL, SDS, and AO was again notable. Co-contaminants generally increased the sorption of these compounds to all soils. Log Kd values of PFBA in soil A increased 85%, 372%, and 32% in the presence of NAPL, SDS, and AO, respectively. Use of Kd values to calculate retardation factors (Rf) of PFAAs demonstrates the variability of co-contaminant impacts on PFAA transport. Whereas NAPL and nonfluorinated surfactants decreased the sorption of perfluorooctanesulfonate (PFOS) at lower PFOS concentrations (1 ?g/L), they led to increases in sorption at higher PFOS concentrations (500 ?g/L). These results demonstrate that PFAA groundwater transport will depend on the solid phase characteristics as well as PFAA concentration and chain length. Detailed site-specific information will likely be needed to accurately predict PFAA transport at AFFF-impacted sites. PMID:23566120

Guelfo, Jennifer L; Higgins, Christopher P

2013-05-01

176

Perfluoroalkyl acid distribution in various plant compartments of edible crops grown in biosolids-amended soils.  

PubMed

Crop uptake of perfluoroalkyl acids (PFAAs) from biosolids-amended soil has been identified as a potential pathway for PFAA entry into the terrestrial food chain. This study compared the uptake of PFAAs in greenhouse-grown radish (Raphanus sativus), celery (Apium graveolens var. dulce), tomato (Lycopersicon lycopersicum), and sugar snap pea (Pisum sativum var. macrocarpon) from an industrially impacted biosolids-amended soil, a municipal biosolids-amended soil, and a control soil. Individual concentrations of PFAAs, on a dry weight basis, in mature, edible portions of crops grown in soil amended with PFAA industrially impacted biosolids were highest for perfluorooctanoate (PFOA; 67 ng/g) in radish root, perfluorobutanoate (PFBA; 232 ng/g) in celery shoot, and PFBA (150 ng/g) in pea fruit. Comparatively, PFAA concentrations in edible compartments of crops grown in the municipal biosolids-amended soil and in the control soil were less than 25 ng/g. Bioaccumulation factors (BAFs) were calculated for the root, shoot, and fruit compartments (as applicable) of all crops grown in the industrially impacted soil. BAFs were highest for PFBA in the shoots of all crops, as well as in the fruit compartment of pea. Root-soil concentration factors (RCFs) for tomato and pea were independent of PFAA chain length, while radish and celery RCFs showed a slight decrease with increasing chain length. Shoot-soil concentration factors (SCFs) for all crops showed a decrease with increasing chain length (0.11 to 0.36 log decrease per CF2 group). The biggest decrease (0.54-0.58 log decrease per CF2 group) was seen in fruit-soil concentration factors (FCFs). Crop anatomy and PFAA properties were utilized to explain data trends. In general, fruit crops were found to accumulate fewer long-chain PFAAs than shoot or root crops presumably due to an increasing number of biological barriers as the contaminant is transported throughout the plant (roots to shoots to fruits). These data were incorporated into a preliminary conceptual framework for PFAA accumulation in edible crops. In addition, these data suggest that edible crops grown in soils conventionally amended for nutrients with biosolids (that are not impacted by PFAA industries) are unlikely a significant source of long-chain PFAA exposure to humans. PMID:24918303

Blaine, Andrea C; Rich, Courtney D; Sedlacko, Erin M; Hundal, Lakhwinder S; Kumar, Kuldip; Lau, Christopher; Mills, Marc A; Harris, Kimberly M; Higgins, Christopher P

2014-07-15

177

Perfluoroalkyl acids in the Canadian environment: multi-media assessment of current status and trends.  

PubMed

In Canada, perfluoroalkyl acids (PFAAs) have been the focus of several monitoring programs and research and surveillance studies. Here, we integrate recent data and perform a multi-media assessment to examine the current status and ongoing trends of PFAAs in Canada. Concentrations of perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA), and other long-chain perfluorocarboxylates (PFCAs) in air, water, sediment, fish, and birds across Canada are generally related to urbanization, with elevated concentrations observed around cities, especially in southern Ontario. PFOS levels in water, fish tissue, and bird eggs were below their respective Draft Federal Environmental Quality Guidelines, suggesting there is low potential for adverse effects to the environment/organisms examined. However, PFOS in fish and bird eggs tended to exceed guidelines for the protection of mammalian and avian consumers, suggesting a potential risk to their wildlife predators, although wildlife population health assessments are needed to determine whether negative impacts are actually occurring. Long-term temporal trends of PFOS in suspended sediment, sediment cores, Lake Trout (Salvelinus namaycush), and Herring Gull (Larus argentatus) eggs collected from Lake Ontario increased consistently from the start of data collection until the 1990s. However, after this time, the trends varied by media, with concentrations stabilizing in Lake Trout and Herring Gull eggs, and decreasing and increasing in suspended sediment and the sediment cores, respectively. For PFCAs, concentrations in suspended sediment, sediment cores, and Herring Gulls generally increased from the start of data collection until present and concentrations in Lake Trout increased until the late 1990s and subsequently stabilized. A multimedia comparison of PFAA profiles provided evidence that unexpected patterns in biota of some of the lakes were due to unique source patterns rather than internal lake processes. High concentrations of PFAAs in the leachate and air of landfill sites, in the wastewater influent/effluent, biosolids, and air at wastewater treatment plants, and in indoor air and dust highlight the waste sector and current-use products (used primarily indoors) as ongoing sources of PFAAs to the Canadian environment. The results of this study demonstrate the utility of integrating data from different media. Simultaneous evaluation of spatial and temporal trends in multiple media allows inferences that would be impossible with data on only one medium. As such, more co-ordination among monitoring sites for different media is suggested for future sampling, especially at the northern sites. We emphasize the importance of continued monitoring of multiple-media for determining future responses of environmental PFAA concentrations to voluntary and regulatory actions. PMID:23831544

Gewurtz, Sarah B; Backus, Sean M; De Silva, Amila O; Ahrens, Lutz; Armellin, Alain; Evans, Marlene; Fraser, Susan; Gledhill, Melissa; Guerra, Paula; Harner, Tom; Helm, Paul A; Hung, Hayley; Khera, Nav; Kim, Min Gu; King, Martha; Lee, Sum Chi; Letcher, Robert J; Martin, Pamela; Marvin, Chris; McGoldrick, Daryl J; Myers, Anne L; Pelletier, Magella; Pomeroy, Joe; Reiner, Eric J; Rondeau, Myriam; Sauve, Marie-Claude; Sekela, Mark; Shoeib, Mahiba; Smith, Daniel W; Smyth, Shirley Anne; Struger, John; Spry, Doug; Syrgiannis, Jim; Waltho, Jasmine

2013-09-01

178

Uptake of perfluoroalkyl acids into edible crops via land applied biosolids: field and greenhouse studies.  

PubMed

The presence of perfluoroalkyl acids (PFAAs) in biosolids destined for use in agriculture has raised concerns about their potential to enter the terrestrial food chain via bioaccumulation in edible plants. Uptake of PFAAs by greenhouse lettuce ( Lactuca sativa ) and tomato ( Lycopersicon lycopersicum ) grown in an industrially impacted biosolids-amended soil, a municipal biosolids-amended soil, and a control soil was measured. Bioaccumulation factors (BAFs) were calculated for the edible portions of both lettuce and tomato. Dry weight concentrations observed in lettuce grown in a soil amended (biosolids:soil dry weight ratio of 1:10) with PFAA industrially contaminated biosolids were up to 266 and 236 ng/g for perfluorobutanoic acid (PFBA) and perfluoropentanoic acid (PFPeA), respectively, and reached 56 and 211 ng/g for PFBA and PFPeA in tomato, respectively. BAFs for many PFAAs were well above unity, with PFBA having the highest BAF in lettuce (56.8) and PFPeA the highest in tomato (17.1). In addition, the BAFs for PFAAs in greenhouse lettuce decreased approximately 0.3 log units per CF2 group. A limited-scale field study was conducted to verify greenhouse findings. The greatest accumulation was seen for PFBA and PFPeA in both field-grown lettuce and tomato; BAFs for PFBA were highest in both crops. PFAA levels measured in lettuce and tomato grown in field soil amended with only a single application of biosolids (at an agronomic rate for nitrogen) were predominantly below the limit of quantitation (LOQ). In addition, corn ( Zea mays ) stover, corn grains, and soil were collected from several full-scale biosolids-amended farm fields. At these fields, all PFAAs were below the LOQ in the corn grains and only trace amounts of PFBA and PFPeA were detected in the corn stover. This study confirms that the bioaccumulation of PFAAs from biosolids-amended soils depends strongly on PFAA concentrations, soil properties, the type of crop, and analyte. PMID:24206563

Blaine, Andrea C; Rich, Courtney D; Hundal, Lakhwinder S; Lau, Christopher; Mills, Marc A; Harris, Kimberly M; Higgins, Christopher P

2013-12-17

179

Evaluation of perfluoroalkyl acid activity using primary mouse and human hepatocytes.  

PubMed

While perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) have been studied at length, less is known about the biological activity of other perfluoroalkyl acids (PFAAs) detected in the environment. Using a transient transfection assay developed in COS-1 cells, our group has previously evaluated a variety of PFAAs for activity associated with activation of peroxisome proliferator-activated receptor alpha (PPAR?). Here we use primary heptatocytes to further assess the biological activity of a similar group of PFAAs using custom designed Taqman Low Density Arrays. Primary mouse and human hepatoyctes were cultured for 48h in the presence of varying concentrations of 12 different PFAAs or Wy14,643, a known activator of PPAR?. Total RNA was collected and the expression of 48 mouse or human genes evaluated. Gene selection was based on either in-house liver microarray data (mouse) or published data using primary hepatocytes (human). Gene expression in primary mouse hepatocytes was more restricted than expected. Genes typically regulated in whole tissue by PPAR? agonists were not altered in mouse cells including Acox1, Me1, Acaa1a, Hmgcs1, and Slc27a1. Cyp2b10, a gene regulated by the constitutive androstane receptor and a transcript normally up-regulated by in vivo exposure to PFAAs, was also unchanged in cultured mouse hepatocytes. Cyp4a14, Ehhadh, Pdk4, Cpt1b, and Fabp1 were regulated as expected in mouse cells. A larger group of genes were differentially expressed in human primary hepatocytes, however, little consistency was observed across compounds with respect to which genes produced a significant dose response making the determination of relative biological activity difficult. This likely reflects weaker activation of PPAR? in human versus rodent cells as well as variation among individual cell donors. Unlike mouse cells, CYP2B6 was up-regulated in human hepatocytes by a number of PFAAs as was PPAR?. Rankings were conducted on the limited dataset. In mouse hepatocytes, the pattern was similar to that previously observed in the COS-1 reporter cell assay. With the exception of PFHxA, longer chain PFAA carboxylates were the most active. The pattern was similar in human hepatocytes, although PFDA and PFOS showed higher activity than previously observed while PFOA showed somewhat less activity. These data reflect inherent challenges in using primary hepatocytes to predict toxicological response. PMID:23567314

Rosen, Mitchell B; Das, Kaberi P; Wood, Carmen R; Wolf, Cynthia J; Abbott, Barbara D; Lau, Christopher

2013-06-01

180

Exposure and effects of perfluoroalkyl compounds on tree swallows nesting at Lake Johanna in east central Minnesota, USA.  

PubMed

Tree swallow (Tachycineta bicolor) samples were collected at a reference lake and a nearby lake (Lake Johanna) in east central Minnesota, USA contaminated with perfluorinated carboxylic and sulfonic acids. Tissues were analyzed for a suite of 13 perfluoroalkyl compounds (PFCs) to quantify exposure and to determine if there was an association between egg concentrations of PFCs and reproductive success of tree swallows. Concentrations of perfluoroocatane sulfonate (PFOS) were elevated in all tree swallow tissues from Lake Johanna compared to tissues collected at the reference lake. Other PFCs, except for two, were elevated in blood plasma at Lake Johanna compared to the reference lake. PFOS was the dominant PFC (>75%) at Lake Johanna, but accounted for <50% of total PFCs at the reference lake. There was a negative association between concentrations of PFOS in eggs and hatching success. Reduced hatching success was associated with PFOS levels as low as 150ng/g wet weight. PMID:21296656

Custer, Christine M; Custer, Thomas W; Schoenfuss, Heiko L; Poganski, Beth H; Solem, Laura

2012-07-01

181

Distribution and fate of perfluoroalkyl substances in municipal wastewater treatment plants in economically developed areas of China.  

PubMed

Wastewater treatment plants (WWTPs) are a significant source for poly-/perfluoroalkyl substances (PFASs) entering the environment. The presence of PFASs in twenty-eight municipal WWTPs from eleven cites in economically developed areas of China were screened. Overall, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) were dominant in wastewater and sludge, and were not effectively removed during wastewater treatment. Elevated influent concentration ratios of perfluorobutanoic acid (PFBA) to PFOA and perfluorobutane sulfonate (PFBS) to PFOS in some WWTPs suggested that short chains substitution were adopted in these cities. Cluster analysis showed treatment processes had important impacts on PFASs profiles in effluent and sludge. Average concentration of total PFCAs in influent from each city and its gross domestic product (GDP) had significant positive correlation. This study provides a snapshot of both domestic and industrial discharges of PFAS to WWTPs as well as PFAS discharge from WWTPs to the aquatic environment in China. PMID:23410673

Zhang, Wei; Zhang, Yating; Taniyasu, Sachi; Yeung, Leo W Y; Lam, Paul K S; Wang, Jianshe; Li, Xinhai; Yamashita, Nobuyoshi; Dai, Jiayin

2013-05-01

182

Exposure and effects of perfluoroalkyl compounds on tree swallows nesting at Lake Johanna in east central Minnesota, USA  

USGS Publications Warehouse

Tree swallow (Tachycineta bicolor) samples were collected at a reference lake and a nearby lake (Lake Johanna) in east central Minnesota, USA contaminated with perfluorinated carboxylic and sulfonic acids. Tissues were analyzed for a suite of 13 perfluoroalkyl compounds (PFCs) to quantify exposure and to determine if there was an association between egg concentrations of PFCs and reproductive success of tree swallows. Concentrations of perfluoroocatane sulfonate (PFOS) were elevated in all tree swallow tissues from Lake Johanna compared to tissues collected at the reference lake. Other PFCs, except for two, were elevated in blood plasma at Lake Johanna compared to the reference lake. PFOS was the dominant PFC (>75%) at Lake Johanna, but accounted for <50% of total PFCs at the reference lake. There was a negative association between concentrations of PFOS in eggs and hatching success. Reduced hatching success was associated with PFOS levels as low as 150 ng/g wet weight.

Custer, Christine M.; Custer, Thomas W.; Schoenfuss, Heiko L.; Poganski, Beth H.; Solem, Laura

2012-01-01

183

Mutual impacts of wheat (Triticum aestivum L.) and earthworms (Eisenia fetida) on the bioavailability of perfluoroalkyl substances (PFASs) in soil.  

PubMed

Wheat and earthworms were exposed individually and together to soils contaminated with 11 perfluoroalkyl substances (PFASs). Wheat accumulated PFASs from soil with root concentration factors and bioconcentration factors that decreased as the number of perfluorinated carbons in the molecule increased. Earthworms accumulated PFASs from soil with biota-to-soil accumulation factors that increased with the number of carbons. Translocation factors (TF) of perfluorinated carboxylates (PFCAs) in wheat peaked at perfluorohexanoic acid and decreased significantly as the number of carbons increased or decreased. Perfluorohexane sulfonate produced the greatest TF of the three perfluorinated sulfonates (PFSAs) examined. Wheat increased the bioaccumulation of all 11 PFASs in earthworms and earthworms increased the bioaccumulation in wheat of PFCAs containing seven or less perfluorinated carbons, decreased bioaccumulation of PFCAs with more than seven carbons, and decreased bioaccumulation of PFSAs. In general, the co-presence of wheat and earthworms enhanced the bioavailability of PFASs in soil. PMID:24158108

Zhao, Shuyan; Fang, Shuhong; Zhu, Lingyan; Liu, Li; Liu, Zhengtao; Zhang, Yahui

2014-01-01

184

Inhibition of human and rat 3beta-hydroxysteroid dehydrogenase and 17beta-hydroxysteroid dehydrogenase 3 activities by perfluoroalkylated substances.  

PubMed

Perfluoroalkylated substances (PFASs) including perfluorooctane acid (PFOA) and perfluorooctane sulfonate (PFOS) have been classified as persistent organic pollutants and are known to cause reduced testosterone production in human males. The objective of the present study was to compare the potencies of five different PFASs including PFOA, PFOS, potassium perfluorooctane sulfonate (PFOSK), potassium perfluorohexane sulfonate (PFHxSK) and potassium perfluorobutane sulfonate (PFBSK) in the inhibition of 3beta-hydroxysteroid dehydrogenase (3beta-HSD) and 17beta-hydroxysteroid dehydrogenase 3 (17beta-HSD3) activities in the human and rat testes. Human and rat microsomal enzymes were exposed to various PFASs. PFOS and PFOSK inhibited rat 3beta-HSD activity with IC(50) of 1.35 + or -0.05 and 1.77 + or - 0.04 microM, respectively, whereas PFHxSK and PFBSK had no effect at concentrations up to 250 microM. All chemicals tested weakly inhibited human 3beta-HSD activity with IC(50)s over 250 microM. On the other hand, PFOS, PFOSK and PFOA inhibited human 17beta-HSD3 activity with IC(50)s of 6.02 + or - 1.02, 4.39 + or - 0.46 and 127.60 + or - 28.52 microM, respectively. The potencies for inhibition of 17beta-HSD3 activity were determined to be PFOSK>PFOS>PFOA>PFHxSK=PFBSK for human 17beta-HSD3 activity. There appears to be a species-dependent sensitivity to PFAS-mediated inhibition of enzyme activity because the IC(50)s of PFOS(K) for inhibition of rat 17beta-HSD3 activity was greater than 250 microM. In conclusion, the present study shows that PFOS and PFOSK are potent inhibitors of rat 3beta-HSD and human 17beta-HSD3 activity, and implies that inhibition of steroidogenic enzyme activity may be a contributing factor to the effects that PFASs exert on androgen secretion in the testis. PMID:20619251

Zhao, Binghai; Hu, Guo-Xin; Chu, Yanhui; Jin, Xiudong; Gong, Shouliang; Akingbemi, Benson T; Zhang, Zhiqiang; Zirkin, Barry R; Ge, Ren-Shan

2010-10-01

185

Validation of a screening method based on liquid chromatography coupled to high-resolution mass spectrometry for analysis of perfluoroalkylated substances in biota  

Microsoft Academic Search

A screening method for analysis of perfluoroalkylated substances (PFAS) in biota samples has been developed and validated using liver samples from polar cod (Boreogadus saida) and glaucous gull (Larus hyperboreus). The method was based on extraction of target compounds from homogenised samples into the solvent mixture used as mobile phase in high-performance liquid chromatography (HPLC), i.e. methanol\\/water (50:50; 2mM ammonium

Urs Berger; Marianne Haukås

2005-01-01

186

Chemically induced unfolding of bovine serum albumin by urea and sodium dodecyl sulfate: a spectral study with the polarity-sensitive charge-transfer fluorescent probe (E)-3-(4-methylaminophenyl)acrylic acid methyl ester.  

PubMed

Sensitivity of the charge-transfer (CT) band of the fluorescence probe (E)-3-(4-methylaminophenyl)acrylic acid methyl ester (MAPAME) towards the polarity of its immediate environment is employed to investigate the binding interaction of the probe with bovine serum albumin (BSA) and uncoiling of BSA by the denaturants urea and sodium dodecyl sulfate micelles. Binding of the probe with BSA produces a blue shift and enhanced intensity of the CT emission band which clearly point toward a decrease in polarity of the immediate environment of MAPAME. This is expected, since binding with BSA moves the probe from a polar water environment to a much less polar, hydrophobic protein interior, where the CT band is expected to be blue-shifted. Higher intensity arises due to fewer non-radiative decay paths available to the probe in the hydrophobic protein environment. Chemically induced unfolding of BSA by urea and sodium dodecyl sulfate is tracked by monitoring the induced spectral changes of the protein-bound probe MAPAME. Red-edge excitation shift or REES, fluorescence resonance energy transfer (FRET) and anisotropy measurements are used to investigate and monitor these binding and unfolding processes. PMID:19466702

Ghosh, Shalini; Guchhait, Nikhil

2009-07-13

187

Serum Free Light Chains  

MedlinePLUS

... website will be limited. Search Help? Serum Free Light Chains Share this page: Was this page helpful? ... top 2. Should everyone have a serum free light chain test? This test is not intended to ...

188

Blood Serum Magnesium  

E-print Network

Key Words · Blood Serum · Magnesium · Flame · Atomic Absorption Method Guide: 40162 Atomic Absorption Method Guide Mg in Blood Serum Principle The sample is diluted 1:100 with deionised water. Sample Preparation Using a micro-pipette, transfer 1.00 mL of the serum sample into a clean, dry 100 m

Wells, Mathew G. - Department of Physical and Environmental Sciences, University of Toronto

189

Distribution of poly- and perfluoroalkyl substances in matched samples from pregnant women and carbon chain length related maternal transfer.  

PubMed

Although levels of poly- and perfluoroalkyl substances (PFASs) in human maternal and neonatal blood have been widely reported in the literature, relationship of maternal-fetal transmission of PFASs with carbon chain length is presently not well understood. In this study, 11 PFASs were analyzed in matched samples, including not only maternal blood (MB, n = 31) and cord blood (CB, n = 30), but also placenta (n = 29) and amniotic fluid (AF, n = 29). Except for perfluorohexanoic acid (PFHxA), the detection frequencies of PFASs were similar among placenta, MB, and CB (>80% for 8 PFASs, nondetectable for 2 PFASs). Though only perfluorooctanoic acid (PFOA) was frequently detected (>90%) in AF, with a median concentration of 0.043 ng/mL, other 5 PFASs were also detectable in AF samples with low concentrations (mean: 0.013-0.191 ng/mL). This suggests that in addition to blood-borne in utero exposure, the fetus is also exposed to low levels of PFASs through AF. Concentrations of PFOA in AF were positively correlated with those in MB (r = 0.738, p < 0.01) and CB (r = 0.683, p < 0.001), suggesting that AF concentration could reflect fetal PFOA exposure during pregnancy and can be used as a biomarker. To clarify the effects of carbon chain length on maternal transfer of PFASs, we calculated maternal transfer efficiencies of PFASs from MB to CB (TMB-CB). A U-shaped trend in TMB-CB of C7-C12 perfluoroalkyl carboxylic acids (PFCAs) with increasing carbon chain length was found in this study for the first time. The U-shaped TMB-CB of PFCAs with carbon chain length is an integrated result of opposite trend of the ratios between MB/placenta and placenta/CB based on carbon chain length. This is the first study to report the occurrence of PFASs in human placenta. The results reported here enable better understanding of the maternal-fetal transmission of PFASs. PMID:23777259

Zhang, Tao; Sun, Hongwen; Lin, Yan; Qin, Xiaolei; Zhang, Yanfeng; Geng, Xia; Kannan, Kurunthachalam

2013-07-16

190

National inventory of perfluoroalkyl substances in archived U.S. biosolids from the 2001 EPA National Sewage Sludge Survey  

PubMed Central

Using liquid chromatography tandem mass spectrometry, we determined the first nationwide inventories of 13 perfluoroalkyl substances (PFASs) in U.S. biosolids via analysis of samples collected by the U.S. Environmental Protection Agency in the 2001 National Sewage Sludge Survey. Perfluorooctane sulfonate [PFOS; 403 ± 127 ng/g dry weight (dw)] was the most abundant PFAS detected in biosolids composites representing 32 U.S. states and the District of Columbia, followed by perfluorooctanoate [PFOA; 34 ± 22 ng/g dw] and perfluorodecanoate [PFDA; 26 ± 20 ng/g dw]. Mean concentrations in U.S. biosolids of the remaining ten PFASs ranged between 2 and 21 ng/g dw. Interestingly, concentrations of PFOS determined here in biosolids collected prior to the phase-out period (2002) were similar to levels reported in the literature for recent years. The mean load of ?PFASs in U.S. biosolids was estimated at 2749–3450 kg/year, of which about 1375–2070 kg is applied on agricultural land and 467–587 kg goes to landfills as an alternative disposal route. This study informs the risk assessment of PFASs by furnishing national inventories of PFASs occurrence and environmental release via biosolids application on land. PMID:23562984

Venkatesan, Arjun K.; Halden, Rolf U.

2013-01-01

191

Distribution of perfluoroalkyl substances (PFASs) with isomer analysis among the tissues of aquatic organisms in Taihu Lake, China.  

PubMed

The distribution of perfluoroalkyl substances (PFASs) and the isomers of perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) was investigated among various tissues (including muscle, gill, kidney, liver) and eggs, in aquatic organisms in Taihu Lake, China. Highest concentration of ?PFASs was mostly found in liver (278-685 ng/g ww) and eggs (66.0-467 ng/g ww) while the lowest was in muscle (40.6-165 ng/g ww). n-PFOS was the predominant PFOS isomer in most of the tissues with a proportion of 46.3-96.5%. Ratios of PFAS concentrations in eggs to those in liver (E/L) increased positively with the protein-water partition coefficient. The E/L of PFOS isomers descended in the order: linear > monomethyl > diperfluoromethyl isomers. The liver/muscle and kidney/muscle ratios of n-PFOS were higher than branched isomers, suggesting that n-PFOS has higher binding affinity with hepatic proteins or branched isomers are preferentially excreted though liver and kidney. PMID:25058420

Fang, Shuhong; Zhao, Shuyan; Zhang, Yifeng; Zhong, Wenjue; Zhu, Lingyan

2014-10-01

192

National inventory of perfluoroalkyl substances in archived U.S. biosolids from the 2001 EPA National Sewage Sludge Survey.  

PubMed

Using liquid chromatography tandem mass spectrometry, we determined the first nationwide inventories of 13 perfluoroalkyl substances (PFASs) in U.S. biosolids via analysis of samples collected by the U.S. Environmental Protection Agency in the 2001 National Sewage Sludge Survey. Perfluorooctane sulfonate [PFOS; 403 ± 127 ng/g dry weight (dw)] was the most abundant PFAS detected in biosolids composites representing 32 U.S. states and the District of Columbia, followed by perfluorooctanoate [PFOA; 34 ± 22 ng/g dw] and perfluorodecanoate [PFDA; 26 ± 20 ng/g dw]. Mean concentrations in U.S. biosolids of the remaining ten PFASs ranged between 2 and 21 ng/g dw. Interestingly, concentrations of PFOS determined here in biosolids collected prior to the phase-out period (2002) were similar to levels reported in the literature for recent years. The mean load of ?PFASs in U.S. biosolids was estimated at 2749-3450 kg/year, of which about 1375-2070 kg is applied on agricultural land and 467-587 kg goes to landfills as an alternative disposal route. This study informs the risk assessment of PFASs by furnishing national inventories of PFASs occurrence and environmental release via biosolids application on land. PMID:23562984

Venkatesan, Arjun K; Halden, Rolf U

2013-05-15

193

Perfluoroalkyl substances in eggs and plasma of an avian top predator, great skua (Stercorarius skua), in the North Atlantic.  

PubMed

Temporal, biological, and environmental factors affecting accumulation of perfluoroalkyl substances (PFASs) are poorly understood in comparison with legacy lipid-soluble persistent organic pollutants. Temporal and biological comparisons of PFAS concentrations were made in great skuas (Stercorarius skua), a marine apex predator. Concentrations of 16 PFASs were quantified, including C4-C10 perfluorosulfonates (PFSAs), perfluorooctanesulfonamide (PFOSA), and C5-C14 perfluorocarboxylates (PFCAs). Concentrations of PFASs (ng/g wet wt) were significantly higher in eggs collected in Shetland in 2008 compared with 1980 for most compounds. However, the magnitude of the differences was small, with a mean increase of 3?ng/g. Levels of PFASs in great skuas were low compared with those of other seabirds in similar ecological niches; and in contrast to other contaminants measured in the same eggs, concentrations of PFASs did not correlate with trophic level. Concentrations of PFASs in adult plasma were significantly higher in males than in females for most PFASs. This suggests that maternal transfer through egg laying may be a significant mode of elimination of PFASs in female great skuas. The low concentrations of PFASs in eggs and plasma compared with other halogenated organic contaminants and other species suggest that great skuas do not bioaccumulate PFASs to the same extent as some other seabirds. PMID:23258709

Leat, Eliza H K; Bourgeon, Sophie; Eze, Jude I; Muir, Derek C G; Williamson, Mary; Bustnes, Jan O; Furness, Robert W; Borgå, Katrine

2013-03-01

194

Removal of PFOS, PFOA and other perfluoroalkyl acids at water reclamation plants in South East Queensland Australia.  

PubMed

This paper examines the fate of perfluorinated sulfonates (PFSAs) and carboxylic acids (PFCAs) in two water reclamation plants in Australia. Both facilities take treated water directly from WWTPs and treat it further to produce high quality recycled water. The first plant utilizes adsorption and filtration methods alongside ozonation, whilst the second uses membrane processes and advanced oxidation to produce purified recycled water. At both facilities perfluorooctane sulfonate (PFOS), perfluorohexane sulfonate (PFHxS), perfluorohexanoic acid (PFHxA) and perfluorooctanoic acid (PFOA) were the most frequently detected PFCs. Concentrations of PFOS and PFOA in influent (WWTP effluent) ranged up to 3.7 and 16 ng L?¹ respectively, and were reduced to 0.7 and 12 ng L?¹ in the finished water of the ozonation plant. Throughout this facility, concentrations of most of the detected perfluoroalkyl compounds (PFCs) remained relatively unchanged with each successive treatment step. PFOS was an exception to this, with some removal following coagulation and dissolved air flotation/sand filtration (DAFF). At the second plant, influent concentrations of PFOS and PFOA ranged up to 39 and 29 ng L?¹. All PFCs present were removed from the finished water by reverse osmosis (RO) to concentrations below detection and reporting limits (0.4-1.5 ng L?¹). At both plants the observed concentrations were in the low parts per trillion range, well below provisional health based drinking water guidelines suggested for PFOS and PFOA. PMID:21051071

Thompson, Jack; Eaglesham, Geoff; Reungoat, Julien; Poussade, Yvan; Bartkow, Michael; Lawrence, Michael; Mueller, Jochen F

2011-01-01

195

Using blood gene signatures for assessing effects of exposure to perfluoroalkyl acids (PFAAs) in humans: the NOWAC postgenome study  

PubMed Central

Perfluoroalkyl acids (PFAAs) are ubiquitously present in human blood samples and the effects of these compounds on human health are not fully characterized. This study was conducted in order to investigate the applicability of peripheral blood gene expressions for exploring the impact of perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA) and perfluorohexane sulfonate (PFHxS) exposure on the general population. PFOS, PFOA and PFHxS were analyzed in blood samples from a representative group of 270 healthy, postmenopausal Norwegian women (48-62 years). Gene expression was measured in the same samples using the Applied Biosystems microarray platform. Forty-eight different gene sets, all previously linked to PFAA exposure were explored in relation to the selected PFAAs. Two gene sets, both related to the citric acid cycle, were differentially expressed between the “PFOS high” (>30ng/ml, n=42) and the “PFOS low” (<30ng/ml, n=228) group. Based on the results of this study we believe that blood gene signatures have a large potential for elucidating which biological pathways are being affected by environmental pollutants. To the best of our knowledge, this study is the first assessment of the impact of PFAAs on blood gene expressions in humans from the general population. PMID:21915359

Rylander, Charlotta; Dumeaux, Vanessa; Olsen, Karina Standahl; Waaseth, Marit; Sandanger, Torkjel M; Lund, Eiliv

2011-01-01

196

Using blood gene signatures for assessing effects of exposure to perfluoroalkyl acids (PFAAs) in humans: the NOWAC postgenome study.  

PubMed

Perfluoroalkyl acids (PFAAs) are ubiquitously present in human blood samples and the effects of these compounds on human health are not fully characterized. This study was conducted in order to investigate the applicability of peripheral blood gene expressions for exploring the impact of perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA) and perfluorohexane sulfonate (PFHxS) exposure on the general population. PFOS, PFOA and PFHxS were analyzed in blood samples from a representative group of 270 healthy, postmenopausal Norwegian women (48-62 years). Gene expression was measured in the same samples using the Applied Biosystems microarray platform. Forty-eight different gene sets, all previously linked to PFAA exposure were explored in relation to the selected PFAAs. Two gene sets, both related to the citric acid cycle, were differentially expressed between the "PFOS high" (>30ng/ml, n=42) and the "PFOS low" (<30ng/ml, n=228) group. Based on the results of this study we believe that blood gene signatures have a large potential for elucidating which biological pathways are being affected by environmental pollutants. To the best of our knowledge, this study is the first assessment of the impact of PFAAs on blood gene expressions in humans from the general population. PMID:21915359

Rylander, Charlotta; Dumeaux, Vanessa; Olsen, Karina Standahl; Waaseth, Marit; Sandanger, Torkjel M; Lund, Eiliv

2011-08-30

197

Trends of Perfluoroalkyl Acid Content in Articles of Commerce-Market Monitoring from 2007 through 2011.  

National Technical Information Service (NTIS)

The U.S. Environmental Protection Agency (EPA) has established an ongoing effort to quantify possible changes in levels of perfluorinated chemicals (PFCs) in articles of commerce (AOCs). Temporal trends in the concentrations of selected PFCs, including pe...

K. A. Krebs, N. F. Roache, R. H. Pope, X. Liu, Z. Guo

2012-01-01

198

Serum Ferritin in Haemodialysis  

Microsoft Academic Search

A rapid assay for serum ferritin was performed in old and new patients undergoing regular dialysis treatment. The mean values were higher in the patients, especially the older patients, than in the controls. The normal differences in serum ferritin with age and sex were absent in the patients. We attribute these changes to iron loss and multiple transfusions received. Tissue

J. E. Marco-Franco; A. Alarcon; A. Morey; C. Pizá; J. Bestard; S. Mairata; A. Galmés; M. Dalmau

1982-01-01

199

Albumin - blood (serum)  

MedlinePLUS

... is a protein made by the liver. A serum albumin test measures the amount of this protein ... Lower-than-normal levels of serum albumin may be a sign of: Kidney diseases Liver disease (for example, hepatitis , or cirrhosis that make cause ascites ) Decreased blood ...

200

Serum-free Media for Culturing and Serial-Passaging of Adult Human Retinal Pigment Epithelium  

Microsoft Academic Search

The ability of a chemically-defined serum-free culture medium to support the attachment, growth and serial passaging of primary adult human retinal pigment epithelial (RPE) cells was studied. Primary cultures of adult human RPE were established in a chemically-defined serum-free culture medium on both bare or bovine corneal endothelial extracellular matrix-coated tissue-culture plastic. Confluent cells were serially passaged in chemically-defined serum-free

TONGALP H. TEZEL; LUCIAN V. DEL PRIORE

1998-01-01

201

Temporal trends of perfluoroalkyl acids in plasma samples of pregnant women in Hokkaido, Japan, 2003-2011.  

PubMed

Perfluoroalkyl acids (PFAAs) are persistent organic pollutants that are used in a wide range of consumer products. Recent epidemiological studies have shown that prenatal exposure to toxic levels of PFAAs in the environment may adversely affect fetal growth and humoral immune response in infants and children. Here we have characterized levels of prenatal exposure to PFAA between 2003 and 2011 in Hokkaido, Japan, by measuring PFAA concentrations in plasma samples from pregnant women. The study population comprised 150 women who enrolled in a prospective birth cohort study conducted in Hokkaido. Eleven PFAAs were measured in maternal plasma samples using simultaneous analysis by ultra-performance liquid chromatography coupled to triple quadrupole tandem mass spectrometry. At the end of the study, in 2011, age- and parity-adjusted mean concentrations of perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnDA), perfluorododecanoic acid (PFDoDA), perfluorotridecanoic acid (PFTrDA), perfluorohexane sulfonate (PFHxS), and perfluorooctane sulfonate (PFOS) were 1.35ng/mL, 1.26ng/mL, 0.66ng/mL, 1.29ng/mL, 0.25ng/mL, 0.33ng/mL, 0.28ng/mL, and 3.86ng/mL, respectively. Whereas PFOS and PFOA concentrations declined 8.4%/y and 3.1%/y, respectively, PFNA and PFDA levels increased 4.7%/y and 2.4%/y, respectively, between 2003 and 2011. PFUnDA, PFDoDA, and PFTrDA were detected in the vast majority of maternal samples, but no significant temporal trend was apparent. Future studies must involve a larger population of pregnant women and their children to determine the effects of prenatal exposure to PFAA on health outcomes in infants and children. PMID:24013022

Okada, Emiko; Kashino, Ikuko; Matsuura, Hideyuki; Sasaki, Seiko; Miyashita, Chihiro; Yamamoto, Jun; Ikeno, Tamiko; Ito, Yoichi M; Matsumura, Toru; Tamakoshi, Akiko; Kishi, Reiko

2013-10-01

202

The determination of perfluoroalkyl substances, brominated flame retardants and their metabolites in human breast milk and infant formula.  

PubMed

In the present study, a novel analytical approach for the simultaneous determination of 18 perfluoroalkyl substances (PFASs) and 11 brominated flame retardants (BFRs) including their hydroxylated metabolites and brominated phenols has been developed and validated for breast milk and infant formula. The sample preparation procedure based on extraction using acetonitrile and subsequent purification by dispersive solid-phase extraction (d-SPE) employing C18 sorbent is rapid, simple and high-throughput. Ultra-high performance liquid chromatography (UHPLC) interfaced with a tandem mass spectrometry (MS/MS) was employed for the identification/quantification of these compounds. The method recoveries of target compounds for both matrices ranged from 80% to 117% with relative standard deviations lower than 28% and quantification limits in the range of 3-200 pg/mL for milk and 5-450 pg/g for infant formula. Within the pilot study, the new method was used for the analysis of PFASs and BFRs in 50 human breast milks and six infant formulas. In the breast milk samples the total contents of PFASs and BFRs were in the range of 38-279 and 45-16,200 pg/mL, respectively. The most abundant PFASs detected in all tested breast milk samples were perfluorooctanoic acid (PFOA) and perfluorooctanesulfonate (PFOS), the latter contaminant was present not only as a linear form but also as a branched isomers. The incidence of BFRs was lower, the only representatives of this group, tetrabromobiphenol A (TBBPA) and ?-hexabromocyclododecane (?-HBCD), were detected in less than 30% of breast milk samples. None of the infant formulas contained BFRs, traces of either PFOS, PFOA or PFNA were found in three samples. PMID:24209347

Lankova, Darina; Lacina, Ondrej; Pulkrabova, Jana; Hajslova, Jana

2013-12-15

203

Occurrence of perfluoroalkyl acids including perfluorooctane sulfonate isomers in Huai River Basin and Taihu Lake in Jiangsu Province, China.  

PubMed

The spatial distribution of 10 perfluoroalkyl acids including linear and branched (six monotrifluoromethyl isomers) perfluorooctane sulfonate (PFOS) in surface water was investigated in Huai River Basin and Taihu Lake in Jiangsu Province, China. In the water samples from Huai River Basin, perfluorooctanoic acid (PFOA) and PFOS were the predominant compounds (mean 18 ng/L and 4.7 ng/L, respectively), while in samples from Taihu Lake, PFOA, perfluorohexanoic acid (PFHxA), and PFOS were the predominant compounds (mean 56 ng/L, 19 ng/L, and 15 ng/L, respectively). Branched PFOS (Br-PFOS) isomers accounting for 48.1% to 62.5% of total PFOS were enriched in all samples from Taihu Lake, compared to technical electrochemical fluorination (ECF) PFOS (Br-PFOS ?30.0%), while the similar phenomena were not found in samples from Huai River Basin (Br-PFOS 29.0-35.0%). Principal component analysis (PCA) on the percentages of the individual isomer showed that the first two components accounted for 78.4% and 15.3% of the overall observed data variance. Samples from Huai River Basin were grouped together with the ECF PFOS standard suggesting the profiles were similar, while samples from Taihu Lake were grouped by themselves, suggesting that isomer profiles in these samples were different from that of Huai River Basin. The obvious difference in isomer profiles probably results from the different environmental behaviors of PFOS isomers and/or unknown sources (PFOS or PFOS precursors). PMID:23253185

Yu, Nanyang; Shi, Wei; Zhang, Beibei; Su, Guanyong; Feng, Jianfang; Zhang, Xiaowei; Wei, Si; Yu, Hongxia

2013-01-15

204

High levels of perfluoroalkyl acids in eggs and embryo livers of great cormorant (Phalacrocorax carbo sinensis) and herring gull (Larus argentatus) from Lake Vänern, Sweden.  

PubMed

In the eggs and developing chick livers in the two wild bird species, great cormorant and herring gull, the concentrations of a range of 15 perfluoroalkyl acids (PFAAs) were determined. Eggs of the two species were collected from Lake Vänern, Sweden, and analysed either as undeveloped egg (whole egg or separated into yolk and albumen) or incubated until start of the hatching process when the chick liver was removed and analysed. High levels of PFAAs were found in all matrixes except albumen. The predominant PFAA was perfluorooctane sulfonate (PFOS), which was found in the ?g/g wet weight (ww) range in some samples of cormorant whole egg, yolk and liver and herring gull egg yolk and liver. The average concentration in yolk was 1,506 ng/g ww in cormorant and 589 ng/g ww in herring gull. The average liver concentrations of PFOS were 583 ng/g ww in cormorant and 508 ng/g ww in herring gull. At these concentrations, biochemical effects in the developing embryo or effects on embryo survival cannot be ruled out. For perfluoroalkyl carboxylates (PFCAs), the liver/egg and liver/yolk concentration ratios increased with PFCA chain length in cormorant but not in herring gull, indicating that chain length could possibly affect egg-to-liver transfer of PFCAs and that species differences may exist. PMID:23463275

Nordén, Marcus; Berger, Urs; Engwall, Magnus

2013-11-01

205

Temporal trends of perfluoroalkyl contaminants in polar bears (Ursus maritimus) from two locations in the North American Arctic, 1972-2002.  

PubMed

Perfluoroalkyl substances are globally distributed anthropogenic contaminants. Their production and use have increased dramatically from the early 1980s. While many recent publications have reported concentrations of perfluorooctane sulfonate (PFOS) and other perfluoroalkyl acids (PFAs) in biotic and abiotic samples, only limited work has addressed temporal trends. In this study we analyzed archived polar bear(Ursus maritimus) livertissue samples from two geographic locations in the North American Arctic, collected from 1972 to 2002. The eastern group, taken from the vicinity of northern Baffin Island, Canada, comprised 31 samples, and the western group, from the vicinity of Barrow, Alaska, comprised 27 samples. Samples were analyzed for perfluorocarboxylic acids (PFCAs) from carbon chain length C8 to C15, perfluorohexane sulfonate, PFOS, the neutral precursor perfluorooctane sulfonamide (PFOSA), as well as 8:2 and 10:2 fluorotelomer acids and their alpha,beta unsaturated acid counterparts. Concentrations of PFOS and PFCAs with carbon chain lengths from C9 to C11 showed an exponential increase between 1972 and 2002 at both locations. Doubling times ranged from 3.6 +/- 0.9 years for perfluorononanoic acid in the eastern group to 13.1 +/- 4.0 years for PFOS in the western group. PFOSA showed decreasing concentrations over time at both locations, while the remaining PFAs showed no significant trends or were not detected in any sample. The doubling time for PFOS was similar to the doubling time of production of perfluoroctylsulfonyl-fluoride-based products during the 1990s. PMID:16572767

Smithwick, Marla; Norstrom, Ross J; Mabury, Scott A; Solomon, Keith; Evans, Thomas J; Stirling, Ian; Taylor, Mitch K; Muir, Derek C G

2006-02-15

206

Temporal trends of perfluoroalkyl concentrations in American Red Cross adult blood donors, 2000-2010.  

PubMed

Eleven perfluorinated alkyl acids (PFAAs) were analyzed in plasma from a total of 600 American Red Cross adult blood donors from six locations in 2010. The samples were extracted by protein precipitation and quantified by using liquid chromatography tandem mass spectrometry (HPLC/MS/MS). The anions of the three perfluorosulfonic acids measured were perfluorobutane sulfonate (PFBS), perfluorohexane sulfonate (PFHxS), and perfluorooctane sulfonate (PFOS). The anions of the eight perfluorocarboxylic acids were perfluoropentanoate (PFPeA), perfluorohexanoate (PFHxA), perfluoroheptanoate (PFHpA), perfluorooctanoate (PFOA), perfluorononanoate (PFNA), perfluorodecanoate (PFDA), perfluoroundecanoate (PFUnA), and perfluorododecanoate (PFDoA). Findings were compared to results from different donor samples analyzed at the same locations collected in 2000-2001 (N = 645 serum samples) and 2006 (N = 600 plasma samples). Most measurements in 2010 were less than the lower limit of quantitation for PFBS, PFPeA, PFHxA, and PFDoA. For the remaining analytes, the geometric mean concentrations (ng/mL) in 2000-2001, 2006, and 2010 were, respectively, PFHxS: (2.25, 1.52, 1.34); PFOS (34.9, 14.5, 8.3); PFHpA (0.13, 0.09, 0.05); PFOA (4.70, 3.44, 2.44); PFNA (0.57, 0.97, 0.83); PFDA (0.16, 0.34, 0.27), and PFUnA (0.10, 0.18, 0.14). The percentage decline (parentheses) in geometric mean concentrations from 2000-2001 to 2010 were PFHxS (40%), PFOS (76%), and PFOA (48%). The decline in PFOS suggested a population halving time of 4.3 years. This estimate is comparable to the geometric mean serum elimination half-life of 4.8 years reported in individuals. This similarity supports the conclusion that the dominant PFOS-related exposures to humans in the United States were greatly mitigated during the phase-out period. PMID:22554481

Olsen, Geary W; Lange, Cleston C; Ellefson, Mark E; Mair, David C; Church, Timothy R; Goldberg, Corinne L; Herron, Ross M; Medhdizadehkashi, Zahra; Nobiletti, John B; Rios, Jorge A; Reagen, William K; Zobel, Larry R

2012-06-01

207

Serum free hemoglobin test  

MedlinePLUS

Blood hemoglobin; Serum hemoglobin ... Hemoglobin (Hb) is the main component of red blood cells. It is a protein that carries oxygen. ... Disorder in which there is excessive breakdown of hemoglobin ( thalassemia ) Transfusion reaction

208

Concentrations of perfluoroalkyl compounds in maternal and umbilical cord sera and birth outcomes in Korea.  

PubMed

This study analyzed the concentrations of perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA) and perfluorohexane sulfonate (PFHxS) in maternal and umbilical cord sera at delivery from the general population in Korea. Seventy samples were analyzed with ion-pairing and LC/MS/MS. PFOS, PFOA and PFHxS were detected in both maternal and umbilical cord sera. There was a high correlation of PFC concentrations between maternal and cord serum samples, implying transplacental transport. Ranking of transplacental transfer efficiency was PFOA>PFHxS>PFOS. Student's t-tests revealed that concentrations of maternal PFOA were related with decreases in birth weight, birth length and ponderal index, suggesting a possible impact on fetal growth. With multiple logistic regression models, maternal PFOS concentration showed a significant inverse association with ponderal index (OR=0.22; 95% CI, 0.05-0.90). Umbilical cord PFHxS concentration showed a significant inverse association with birth weight (OR=0.26; 95% CI, 0.08-0.85) or a marginally significant inverse association with birth length (OR=0.33; 95% CI, 0.09-1.17). This is the first report demonstrating an inverse association of birth outcomes with PFHxS exposure. Concentrations of maternal PFOA were decreased with parity, implying that delivery is one of the major routes for PFOA elimination in women. This study demonstrated prenatal exposure of PFCs through placental transfer which could result in possible developmental effects in the population sampled. Our results may provide data basis to conduct a larger scale investigation into developmental effects of PFCs in the future and contribute to understanding levels of PFC contaminations from a variety of populations in the globe. PMID:22990023

Lee, Youn Ju; Kim, Min-Kyun; Bae, Jisuk; Yang, Jae-Ho

2013-02-01

209

Regulation of serum phosphate.  

PubMed

The regulation of serum phosphate, an acknowledged risk factor for chronic kidney disease and cardiovascular mortality, is poorly understood. The discovery of fibroblast growth factor 23 (FGF23) as a key regulator of renal phosphate handling and activation of vitamin D has revolutionized our comprehension of phosphate homeostasis. Through as yet undetermined mechanisms, circulating and dietary phosphate appear to have a direct effect on FGF23 release by bone cells that, in turn, causes renal phosphate excretion and decreases intestinal phosphate absorption through a decrease in vitamin D production. Thus, the two major phosphaturic hormones, PTH and FGF23, have opposing effects on vitamin D production, placing vitamin D at the nexus of phosphate homeostasis. While our understanding of phosphate homeostasis has advanced, the factors determining regulation of serum phosphate level remain enigmatic. Diet, time of day, season, gender, age and genetics have all been identified as significant contributors to serum phosphate level. The effects of these factors on serum phosphate have major implications for what is understood as 'normal' and for studies of phosphate homeostasis and metabolism. Moreover, other hormonal mediators such as dopamine, insulin-like growth factor, and angiotensin II also affect renal handling of phosphate. How the major hormone effects on phosphate handling are regulated and how the effect of these other factors are integrated to yield the measurable serum phosphate are only now beginning to be studied. PMID:24973411

Lederer, Eleanor

2014-09-15

210

Serum pneumoproteins in firefighters.  

PubMed

Serum Clara cell protein (CC16) and surfactant-associated protein A (SP-A) were measured in a cross-sectional study in 402 firefighters. For the population as a whole, no associations were detected between serum pneumoproteins and smoke exposure. SP-A levels were increased in symptomatic subjects exposed to fire smoke within 2 days before testing. SP-A levels were higher after an inhalation incident ever. CC16 was negatively associated with the number of fires fought in the last 12 months in current nonsmokers. These associations between pneumoprotein levels reiterate the importance of adequate use of self-contained breathing apparatus by firefighters. PMID:21595570

Greven, Frans; Krop, Esmeralda; Burger, Nena; Kerstjens, Huib; Heederik, Dick

2011-06-01

211

Field study on the uptake and translocation of perfluoroalkyl acids (PFAAs) by wheat (Triticum aestivum L.) grown in biosolids-amended soils.  

PubMed

Field experiments were performed to evaluate the uptake and translocation of perfluoroalkyl acids (PFAAs) in wheat (Triticum aestivum L.) grown in soils amended with biosolids at different rates. Nine perfluorocarboxylic acids (PFCAs) and three perfluorosulfonic acids (PFSAs) were detected in the soils and wheat tissues. Total concentrations of PFAAs in the soils and wheat root, straw, husk and grain increased with increasing application of biosolids. PFCA concentrations in grain increased logarithmically with increasing PFCA concentrations in soils (P < 0.01) while PFSAs in grain were correlated linearly with PFSA concentrations in soils (P < 0.01), indicating that PFCAs and PFSAs may have different transport pathways from soil to grain. While no significant correlation was found between the root concentration factors (Croot/Csoil) and PFAA carbon chain length, the transfer factors from roots to straws (Cstraw/Croot) and from straws to grains (Cgrain/Cstraw) correlated negatively with PFAA carbon chain length (P < 0.01). PMID:24184376

Wen, Bei; Li, Longfei; Zhang, Hongna; Ma, Yibing; Shan, Xiao-Quan; Zhang, Shuzhen

2014-01-01

212

Oxadiazolyl-pyridines and perfluoroalkyl-carboxylic acids as building blocks for protic ionic liquids: crossing the thin line between ionic and hydrogen bonded materials.  

PubMed

A series of 18 samples has been prepared in order to obtain fluorinated materials as Protic Ionic Liquids (PILs). These were synthesized by appropriately mixing 1,2,4-oxadiazoles derivatised with two pyridines, or one pyridine and a fluorinated chain, and perfluoroalkyl-carboxylic acids, either mono- or dicarboxylic, leading to symmetric and non-symmetric materials. Many of them showed low melting points. However, the possibility of classifying the synthesized materials as PILs is discussed in terms of effective ionicity of the systems by the combination of Density Functional Theory (DFT) calculation and IR spectroscopy. The important outcome of our investigation is that the complete proton transfer reaction cannot be taken for granted. The thermal behaviour of the new fluorinated materials was also studied by Differential Scanning Calorimetry (DSC) and Thermogravimetric analysis (TGA). PMID:23001030

Pibiri, I; Pace, A; Buscemi, S; Causin, V; Rastrelli, F; Saielli, G

2012-11-01

213

Janus Serum Bank  

Cancer.gov

The Janus Serum bank was established in order to collect and store blood samples from presumably healthy individuals for future use in cancer research. The intention was to obtain information on factors important in the pathogenesis and etiology of cancer by examining blood samples obtained during the preclinical stage or latent period before the tumor has developed.

214

Perfluoroalkyl substances in the blood of wild rats and mice from 47 prefectures in Japan: use of samples from nationwide specimen bank.  

PubMed

Numerous studies have reported on the global distribution, persistence, fate, and toxicity of perfluoroalkyl and polyfluoroalkyl substances (PFASs). However, studies on PFASs in terrestrial mammals are scarce. Rats can be good sentinels of human exposure to toxicants because of their habitat, which is in close proximity to humans. Furthermore, exposure data measured for rats can be directly applied for risk assessment because many toxicological studies use rodent models. In this study, a nationwide survey of PFASs in the blood of wild rats as well as surface water samples collected from rats' habitats from 47 prefectures in Japan was conducted. In addition to known PFASs, combustion ion chromatography technique was used for analysis of total fluorine concentrations in the blood of rats. In total, 216 blood samples representing three species of wild rats (house rat, Norway rats, and field mice) were analyzed for 23 PFASs. Perfluorooctanesulfonate (PFOS; concentration range <0.05-148 ng/mL), perfluorooctane sulfonamide (PFOSA; <0.1-157), perfluorododecanoate (<0.05-5.8), perfluoroundecanoate (PFUnDA; <0.05-51), perfluorodecanoate (PFDA; <0.05-9.7), perfluorononanoate (PFNA; <0.05-249), and perfluorooctanoate (PFOA) (<0.05-60) were detected >80 % of the blood samples. Concentrations of several PFASs in rat blood were similar to those reported for humans. PFSAs (mainly PFOS) accounted for 45 % of total PFASs, whereas perfluoroalkyl carboxylates (PFCAs), especially PFUnDA and PFNA, accounted for 20 and 10 % of total PFASs, respectively. In water samples, PFCAs were the predominant compounds with PFOA and PFNA found in >90 % of the samples. There were strong correlations (p < 0.001 to p < 0.05) between human population density and levels of PFOS, PFNA, PFOA, and PFOSA in wild rat blood. PMID:23494483

Taniyasu, Sachi; Senthilkumar, Kurunthachalam; Yamazaki, Eriko; Yeung, Leo W Y; Guruge, Keerthi S; Kannan, Kurunthachalam; Yamashita, Nobuyoshi

2013-07-01

215

Serum S100?  

PubMed Central

BACKGROUND S100? protein is expressed constitutively by brain astrocytes. Elevated S100? levels in cerebrospinal fluid and serum reported after head trauma, subarachnoid hemorrhage, and stroke were correlated with the extent of brain damage. Because elevated serum S100? also was shown to indicate blood-brain barrier (BBB) dysfunction in the absence of apparent brain injury, it remains unclear whether elevation of serum levels of S100? reflect BBB dysfunction, parenchymal damage, or both. METHODS The authors conducted a prospective study of serum S100? levels in six patients who underwent hyperosmotic BBB disruption (BBBD) with intraarterial chemotherapy for primary central nervous system lymphoma. In addition, 53 serum S100? samples were measured in 51 patients who had a variety of primary or metastatic brain lesions at the time of neuroimaging. RESULTS S100? was correlated directly with the degree of clinical and radiologic signs of BBBD in patients who were enrolled in the hyperosmotic study. In patients with neoplastic brain lesions, gadolinium enhancement on a magnetic resonance image was correlated with elevated S100? levels (n = 45 patients; 0.16 ± 0.1 ?g/L; mean ± standard error of the mean) versus nonenhancing scans (n = 8 patients; 0.069 ± 0.04 ?g/L). Primary brain tumors (n = 8 patients; 0.12 ± 0.08) or central nervous system metastases also presented with elevated serum S100? levels (n = 27 patients; 0.14 ± 0.34). Tumor volume was correlated with serum S100? levels only in patients with vestibular schwannoma (n = 6 patients; 0.13 ± 0.10 ?g/L) but not in patients with other brain lesions. CONCLUSIONS S100? was correlated directly with the extent and temporal sequence of hyperosmotic BBBD, further suggesting that S100? is a marker of BBB function. Elevated S100? levels may indicate the presence of radiologically detectable BBB leakage. Larger prospective studies may better determine the true specificity of S100? as a marker for BBB function and as an early detection or follow-up marker of brain tumors. PMID:12767094

Kanner, Andrew A.; Marchi, Nicola; Fazio, Vincent; Mayberg, Marc R.; Koltz, Michael T.; Siomin, Vitaly; Stevens, Glen H. J.; Masaryk, Thomas; Ayumar, Barbara; Vogelbaum, Michael A.; Barnett, Gene H.; Janigro, Damir

2014-01-01

216

Synthesis, structure, electronic spectroscopy, photophysics, electrochemistry, and X-ray photoelectron spectroscopy of highly-electron-deficient [5,10,15,20-tetrakis(perfluoroalkyl)porphinato]zinc(II ) complexes and their free base derivatives  

SciTech Connect

The synthesis, optical spectroscopy, photophysical properties, electrochemistry, and X-ray photoelectron spectroscopy of a series of [5,10,15,20-tetrakis(perfluoroalkyl)porphinato]zinc(II ) complexes and their free base analogs are reported. The title compounds were prepared by a condensation methodology that utilizes perfluoro-1-(2`-pyrrolyl)-1-alkanol precursors and employs continuous water removal throughout the course of the reaction to yield the meso perfluorocarbon-substituted porphyrins. The nature of the porphyrin-pendant meso-perfluoroalkyl group exerts considerable influence over the macrocycle`s solubility properties. The structure of the monopyridyl adduct of [5,10,15,20-tetrakis(heptafluoropropyl)porphinato] zinc(II) features an S{sub 4}-distorted porphyrin core; X-ray data are given. Electrochemical studies carried out on these porphyrin and (porphinato)zinc(II) complexes indicate that meso-perfluoroalkylporphyrins are among the most electron-deficient porphyrinic species known. X-ray photoelectron spectroscopy experiments corroborate the electron poor nature of these systems and evince extreme stabilization of the nitrogen ls orbitals, consonant with particularly effective removal of electron density from the macrocycle by the meso-perfluoroalkyl moieties that is modulated by {sigma}-symmetry orbitals. 27 refs., 8 figs., 6 tabs.

Goll, J.G.; Moore, K.T.; Therien, M.J. [Univ. of Pennsylvania, Philadelphia, PA (United States)] [Univ. of Pennsylvania, Philadelphia, PA (United States); Ghosh, A. [Univ., of Tromso (Norway)] [Univ., of Tromso (Norway)

1996-09-04

217

Serum sepsis, not sickness.  

PubMed

Rarely taught in medical schools, clinical reasoning is the ability to discern the important from the unimportant and to arrive at accurate and efficient clinical conclusions. Identifying errors in reasoning is difficult; however, undetected clinical reasoning errors can have exponential consequences. As quality and patient safety come into focus, identifying and preventing clinical reasoning errors have become imperative. The authors present a case of a man sent for admission from a subspecialty clinic diagnosed with infliximab-induced serum sickness. Not countering the expert's diagnosis, initial workup failed to diagnose joint abscess and sepsis. Heuristics are mental shortcuts used to make decision making more efficient but can lead to error. The anchoring heuristic, premature closure, confirmation bias and the blind obedience heuristic are examples. Introspective surveillance and interactive hypothesis testing defend against heuristics. The authors conclude by discussing 4 types of hypersensitivity reactions, serum sickness in particular, and the chimeric nature of infliximab. PMID:21273840

Guidry, Michelle M; Drennan, Robert H; Weise, Jeff; Hamm, L Lee

2011-02-01

218

The Human Serum Metabolome  

PubMed Central

Continuing improvements in analytical technology along with an increased interest in performing comprehensive, quantitative metabolic profiling, is leading to increased interest pressures within the metabolomics community to develop centralized metabolite reference resources for certain clinically important biofluids, such as cerebrospinal fluid, urine and blood. As part of an ongoing effort to systematically characterize the human metabolome through the Human Metabolome Project, we have undertaken the task of characterizing the human serum metabolome. In doing so, we have combined targeted and non-targeted NMR, GC-MS and LC-MS methods with computer-aided literature mining to identify and quantify a comprehensive, if not absolutely complete, set of metabolites commonly detected and quantified (with today's technology) in the human serum metabolome. Our use of multiple metabolomics platforms and technologies allowed us to substantially enhance the level of metabolome coverage while critically assessing the relative strengths and weaknesses of these platforms or technologies. Tables containing the complete set of 4229 confirmed and highly probable human serum compounds, their concentrations, related literature references and links to their known disease associations are freely available at http://www.serummetabolome.ca. PMID:21359215

Psychogios, Nikolaos; Hau, David D.; Peng, Jun; Guo, An Chi; Mandal, Rupasri; Bouatra, Souhaila; Sinelnikov, Igor; Krishnamurthy, Ramanarayan; Eisner, Roman; Gautam, Bijaya; Young, Nelson; Xia, Jianguo; Knox, Craig; Dong, Edison; Huang, Paul; Hollander, Zsuzsanna; Pedersen, Theresa L.; Smith, Steven R.; Bamforth, Fiona; Greiner, Russ; McManus, Bruce; Newman, John W.; Goodfriend, Theodore; Wishart, David S.

2011-01-01

219

The impact of semiconductor, electronics and optoelectronic industries on downstream perfluorinated chemical contamination in Taiwanese rivers.  

PubMed

This study provides the first evidence on the influence of the semiconductor and electronics industries on perfluorinated chemicals (PFCs) contamination in receiving rivers. We have quantified ten PFCs, including perfluoroalkyl sulfonates (PFASs: PFBS, PFHxS, PFOS) and perfluoroalkyl carboxylates (PFCAs: PFHxA, PFHpA, PFOA, PFNA, PFDA, PFUnA, PFDoA) in semiconductor, electronic, and optoelectronic industrial wastewaters and their receiving water bodies (Taiwan's Keya, Touchien, and Xiaoli rivers). PFOS was found to be the major constituent in semiconductor wastewaters (up to 0.13 mg/L). However, different PFC distributions were found in electronics plant wastewaters; PFOA was the most significant PFC, contributing on average 72% to the effluent water samples, followed by PFOS (16%) and PFDA (9%). The distribution of PFCs in the receiving rivers was greatly impacted by industrial sources. PFOS, PFOA and PFDA were predominant and prevalent in all the river samples, with PFOS detected at the highest concentrations (up to 5.4 microg/L). PMID:19117653

Lin, Angela Yu-Chen; Panchangam, Sri Chandana; Lo, Chao-Chun

2009-04-01

220

Polymers for electronics and chemical sensing applications  

E-print Network

The incorporation of molecular structures such as shape persistent molecular frameworks, strong hydrogen bond donor groups or perfluoro-alkyl groups can result in considerable gains in the performance of some established ...

Amara, John Paul

2006-01-01

221

Altered Fatty Acid Homeostasis and Related Toxicologic Sequelae in Rats Exposed to Dietary Potassium Perfluorooctanesulfonate (PFOS)  

Microsoft Academic Search

Perfluorooctanesulfonate (PFOS) is one of a class of industrial chemicals known as perfluoroalkyl acids, which have a wide variety of uses as surfactants and stain repellants. The presence of fluorochemical residues in human blood, plasma, or serum from sample populations worldwide is indicative of widespread human exposure. Previous studies demonstrated that PFOS alters fatty acid metabolism in the liver of

Ivan Curran; S. Lynn Hierlihy; Virginia Liston; Peter Pantazopoulos; Andrée Nunnikhoven; Sheryl Tittlemier; Michael Barker; Keith Trick; Genevieve Bondy

2008-01-01

222

EXPERIMENTAL SERUM DISEASE  

PubMed Central

The intravenous injection of one large dose of serum into rabbits caused a variety of changes of considerable complexity. 1. There was an immediate proliferation of mesenchymal cells, including plasma cells, particularly in heart, lungs, and spleen. 2. The signs of serum disease developed only at the time of abundant antibody formation, before significant quantities of antibody were laid down in the vascular connective tissue. 3. Allergic arteritis, marked glomerular nephritis, myocardial necrosis, and Aschoff body-like structures were seen only after hypersensitivity had developed. It appears that most, if not all, of these pathological alterations were true Arthus phenomena. 4. There were at least two distinct varieties of allergic arteritis and glomerular nephritis, namely a proliferative one, following the first injection, and a a necrotizing one, seen only after 2 injections. It appears that the first was a subacute Arthus phenomenon, while the latter was an acute Arthus phenomenon superimposed on a subacute one. The subacute experimental glomerular nephritis resembled the intracapillary glomerulonephritis in man, while the acute variety was like human extracapillary glomerular nephritis. PMID:18099163

Ehrich, W. E.; Seifter, Joseph; Forman, Carolyn

1949-01-01

223

Transactivation potencies of the Baikal seal (Pusa sibirica) peroxisome proliferator-activated receptor ? by perfluoroalkyl carboxylates and sulfonates: estimation of PFOA induction equivalency factors.  

PubMed

The present study assessed the transactivation potencies of the Baikal seal (Pusa sibirica) peroxisome proliferator-activated receptor ? (BS PPAR?) by perfluorochemicals (PFCs) having various carbon chain lengths (C4-C12) using an in vitro reporter gene assay. Among the twelve PFCs treated with a range of 7.8-250 ?M concentration, eight perfluoroalkyl carboxylates (PFCAs) and two perfluoroalkyl sulfonates (PFSAs) induced BS PPAR?-mediated transcriptional activities in a dose-dependent manner. To compare the BS PPAR? transactivation potencies of PFCs, the present study estimated the PFOA induction equivalency factors (IEFs), a ratio of the 50% effective concentration of PFOA to the concentration of each compound that can induce the response corresponding to 50% of the maximal response of PFOA. The order of IEFs for the PFCs was as follows: PFOA (IEF: 1)>PFHpA (0.89)>PFNA (0.61)>PFPeA (0.50)>PFHxS (0.41)>PFHxA (0.38)?PFDA (0.37)>PFBA (0.26)=PFOS (0.26)>PFUnDA (0.15)?PFDoDA and PFBuS (not activated). The structure-activity relationship analysis showed that PFCAs having more than seven perfluorinated carbons had a negative correlation (r=-1.0, p=0.017) between the number of perfluorinated carbons and the IEF of PFCAs, indicating that the number of perfluorinated carbon of PFCAs is one of the factors determining the transactivation potencies of the BS PPAR?. The analysis also indicated that PFCAs were more potent than PFSAs with the same number of perfluorinated carbons. Treatment with a mixture of ten PFCs showed an additive action on the BS PPAR? activation. Using IEFs of individual PFCs and hepatic concentrations of PFCs in the liver of wild Baikal seals, the PFOA induction equivalents (IEQs, 5.3-58 ng IEQ/g wet weight) were calculated. The correlation analysis revealed that the hepatic total IEQs showed a significant positive correlation with the hepatic expression levels of cytochrome P450 4A-like protein (r=0.53, p=0.036). This suggests that our approach may be useful for assessing the potential PPAR?-mediated biological effects of complex mixtures of PFCs in wild Baikal seal population. PMID:21381677

Ishibashi, Hiroshi; Kim, Eun-Young; Iwata, Hisato

2011-04-01

224

Hair: A Diagnostic Tool to Complement Blood Serum and Urine.  

ERIC Educational Resources Information Center

Trace elements and some drugs can be identified in hair and it seems likely that other organic chemicals will be identifiable in the future. Since hair is so easily collected, stored, and analyzed it promises to be an ideal complement to serum and urine analysis as a diagnostic tool. (BB)

Maugh, Thomas H., II

1978-01-01

225

Surface characterization of titanium and adsorption of bovine serum albumin  

Microsoft Academic Search

The surface oxide films on titanium were characterized and the relationship between the characterization and the adsorption of bovine serum albumin (BSA) on titanium was studied. The surface oxide films on titanium were obtained by heat-treatment in different oxidizing atmospheres, such as air and water vapor. The surface roughness, energy, morphology, chemical composition and crystal structure were used to characterize

B. Feng; J. Weng; B. C. Yang; J. Y. Chen; J. Z. Zhao; L. He; S. K. Qi; X. D Zhang

2002-01-01

226

High-temperature and photochemical syntheses of C[subscript 60] and C[subscript 70] fullerene derivatives with linear perfluoroalkyl chains  

SciTech Connect

New experimental results on perfluoroalkylation of C{sub 60} and C{sub 70} with the use of R{sub f}I (R{sub f} = CF{sub 3}, C{sub 2}F{sub 5}, n-C{sub 3}F{sub 7}, n-C{sub 4}F{sub 9}, and n-C{sub 6}F{sub 13}), along with a critical overview of the existing synthetic methods, are presented. For the selected new fullerene (R{sub f}){sub n} compounds we report spectroscopic, electrochemical and structural data, including improved crystallographic data for the isomers of C{sub 70}(C{sub 2}F{sub 5}){sub 10} and C{sub 60}(C{sub 2}F{sub 5}){sub 10}, and the first X-ray structural data for the dodecasubstituted perfluoethylated C{sub 70} fullerene, C{sub 70}(C{sub 2}F{sub 5}){sub 12}, which possesses unprecedented addition pattern.

Shustova, Natalia B.; Kareev, Ivan E.; Kuvychko, Igor V.; Whitaker, James B.; Lebedkin, Sergey F.; Popov, Alexey A.; Dunsch, Lothar; Chen, Yu-Sheng; Seppelt, Konrad; Strauss, Steven H.; Boltalina, Olga V. (Freie); (CSU); (Leibniz); (Russ. Acad. Sci.); (Karlsruhe); (UC)

2012-04-30

227

Global emission inventories for C4-C14 perfluoroalkyl carboxylic acid (PFCA) homologues from 1951 to 2030, Part I: production and emissions from quantifiable sources.  

PubMed

We quantify global emissions of C4-C14 perfluoroalkyl carboxylic acid (PFCA) homologues during the life-cycle of products based on perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorooctane sulfonyl fluoride (POSF), and fluorotelomer compounds. We estimate emissions of 2610-21400 tonnes of C4-C14 PFCAs in the period from 1951 to 2015, and project 20-6420 tonnes to be emitted from 2016 to 2030. The global annual emissions steadily increased in the period 1951-2002, followed by a decrease and then another increase in the period 2002-2012. Releases from fluoropolymer production contributed most to historical PFCA emissions (e.g. 55-83% in 1951-2002). Since 2002, there has been a geographical shift of industrial sources (particularly fluoropolymer production sites) from North America, Europe and Japan to emerging Asian economies, especially China. Sources differ between PFCA homologues, sometimes considerably, and the relative contributions of each source change over time. For example, whereas 98-100% of historical (1951-2002) PFOA emissions are attributed to direct releases during the life-cycle of products containing PFOA as ingredients or impurities, a much higher historical contribution from PFCA precursor degradation is estimated for some other homologues (e.g. 9-78% for PFDA). We address the uncertainties of the PFCA emissions by defining a lower and a higher emission scenario, which differ by approximately a factor of eight. PMID:24932785

Wang, Zhanyun; Cousins, Ian T; Scheringer, Martin; Buck, Robert C; Hungerbühler, Konrad

2014-09-01

228

Orthogonal zirconium diol/C18 liquid chromatography-tandem mass spectrometry analysis of poly and perfluoroalkyl substances in landfill leachate.  

PubMed

Leachates coming from landfills contain a myriad of compounds of potential environmental and human health concern, including per- and polyfluorinated alkyl substances (PFASs). Micro liquid-liquid extraction was combined with a 900?l large volume injection (LVI) for the analysis of 70 PFASs in landfill leachate by orthogonal LC-MS/MS. The LVI approach introduced 7 times more extract than conventional injection approaches. Two zirconium-modified diol guard columns effectively retained PFASs from the organic leachate extract and an analytical C18 column was used for separation. Method accuracy and precision for PFASs with analytical grade reference materials ranged from 81-120% and 5.5-33%, respectively. Estimated method detection limits in the low to sub-ng/L. Seven landfill leachates were analyzed by the optimized analytical method for the purposes of method demonstration. Leachates were characterized by a wide variety of PFASs, reporting on 36 previously-unanalyzed PFASs in leachate. Perfluoroalkyl carboxylates were the most abundant class detected while phosphorous-containing PFASs, present in all leachates, were at low concentrations. The 3-perfluoropentyl propanoate (5:3 FTCA) was the most concentrated analyte in most samples and constitutes a previously unreported but significant component of landfill leachate. PMID:25103279

Allred, B McKay; Lang, Johnsie R; Barlaz, Morton A; Field, Jennifer A

2014-09-12

229

Synergistic effects of perfluoroalkyl acids mixtures with J-shaped concentration-responses on viability of a human liver cell line.  

PubMed

Some perfluoroalkyl acids (PFAAs) are highly persistent and bioaccumulative, resulting in their broad coexisting distribution in humans and the environment. Our aim was to investigate the individual and joint effects of PFAAs on cellular viability of a human liver cell line (HL-7702) using the MTT assay. Equipartition ray design and equivalent-effect concentration ratio (EECR) mixtures were used to investigate the binary and multiple effects of PFAAs, respectively. All tested PFAAs mixtures and the individuals (except perfluorododecanoic acid (PFDoDA) and perfluorotetradecanoic acid (PFTeDA)) showed obvious non-monotonic J-shaped concentration-response curves (CRC) on HL-7702. The inhibitory effect of individual PFAAs increased with the elongation of the carbon chain and was dominated by their molecular volume. The three binary mixtures (PFOA/S, PFHxA/S and PFBA/S) showed that synergistic effects occurred under effective inhibitory concentrations (IC) of IC0, IC10, and IC50 in mixtures, while for IC-20 the synergistic effect only occurred under higher PFSA proportion in mixtures. Furthermore, EECR mixtures of the nine individual PFAAs with J-shaped CRC also showed synergistic effects. However, mixtures of the eleven individual PFAAs including those with S-shaped CRC resulted in partial addition effects on HL-7702. Our results indicated that the individual stimulatory responses of HL-7702 to PFAA may produce adverse effects in mixtures at relevant dose levels. PMID:23942018

Hu, Jiayue; Li, Juan; Wang, Jianshe; Zhang, Aiqian; Dai, Jiayin

2014-02-01

230

Characterization of gender-specific bovine serum  

Microsoft Academic Search

Animal cell cultures generally require a nutrient-rich medium supplemented with animal serum. Adult bovine serum contains a variety of nutrients including inorganic minerals, vitamins, salts, proteins and lipids as well as growth factors that promote animal cell growth. To evaluate the potential use of gender-specific bovine serum (GSBS) for cell culture, the biochemical properties of male serum (MS), female serum

Jihoe Kim; Minsoo Kim; Sang-Soep Nahm; Dong-Mok Lee; Smritee Pokharel; Inho Choi

2011-01-01

231

SERUM BACTERICIDAL ACTIVITY AGAINST 'LEGIONELLA PNEUMOPHILA'  

EPA Science Inventory

Two strains of Legionella pneumophila serogroup 1 (UH1 and RH1) were incubated in fresh human serum. The UH1 strain was serum-resistant, whereas the RH1 strain was serum-susceptible. The bactericidal activity of fresh serum was abrogated by heating. Serum resistance of L. pneumop...

232

Serum vitamin c and iron levels in oral submucous fibrosis  

PubMed Central

Background: In this study Serum Vitamin C and Iron levels in Oral submucous fibrosis (OSMF) were estimated. The objective was to evaluate the correlation between Serum Vitamin C and Iron levels in OSMF individuals. Serum Iron content can be a predictor for the progression of this condition. OSMF is basically a disorder of collagen metabolism where Vitamin C gets utilized in conversion of proline into hydroxyproline, this hydroxylation reaction requires ferrous Iron and Vitamin C. Many studies regarding micronutrients and other antioxidants levels have been emphasized, but very few studies are done on the Serum levels of Vitamin C and its correlation with Iron in OSMF patients. Methods: Thirty five OSMF patients and 50 deleterious habit free healthy individuals (controls) were selected. Two ml of venous blood was collected from each individual. Vitamin C level in serum was estimated by 2-4 dinitrophenylhydrazine method and Iron estimated by Tripyridyl method. Results: The level of Serum Vitamin-C and Iron was significantly decreased in OSMF patients when compared to controls which were statistically significant. Conclusion: On the basis of these observations, it seems possible that the chemical, thermal and/or mechanical factors associated with the use of areca nut may act in conjunction with the Vitamin C and Iron deficiency leading to the development of OSMF. Therapeutic substitution of vitamin C and Iron may be recommended in the management of OSMF

Guruprasad, R; Nair, Preeti P; Singh, Manika; Singh, Manishi; Singh, MP; Jain, Arpit

2014-01-01

233

FACTORS CONTROLLING SERUM ?-GLOBULIN CONCENTRATION  

PubMed Central

Both synthetic and catabolic processes determine the serum ?-globulin level. The rate of ?-globulin synthesis appears to be the primary factor determining the amount of serum ?-globulin. Increase of ?-globulin synthesis (as may occur following immunization or development of plasma cell tumor) elevates the serum ?-globulin level. This, in turn, accelerates the fractional rate of ?-globulin catabolism. The change in catabolic rate reduces the dimensions of the serum change from that which would occur if synthesis alone determined the serum ?-globulin level. The present studies indicate the existence of a homeostatic mechanism controlling the rate of ?-globulin catabolism. The mechanisms of ?-globulin catabolism are specific and selective. Marked serum increase of other immunoglobulin components (?2A-globulins and ?1-macroglobulins) do not accelerate ?-globulin catabolism. Similarly, serum albumin increases do not influence ?-globulin catabolism. The site determining ?-globulin catabolism is restricted to a part of the ?-globulin molecule; i.e., on the F piece obtained by papain digestion and, by inference, on the H chains obtained by reduction and alkylation of ?-globulin molecules. PMID:14087625

Fahey, John L.; Robinson, Alan G.

1963-01-01

234

Serum homocysteine in Indian adolescents  

Microsoft Academic Search

Objective  To assess serum homocysteine levels and its association with conventional risk factors for cardiovascular disease (CVD) in\\u000a Indian adolescents.\\u000a \\u000a \\u000a \\u000a Methods  This was a cross-sectional study conducted in tertiary care hospital in northern India in apparently healthy adolescents aged\\u000a 10–19 yr. A pre-designed questionnaire was used to assess conventional risk factors. Serum homocysteine levels of ? 12?mol\\/L,\\u000a serum triglycerides ? 150 mg%

Pratima Anand; Shally Awasthi; Abbas Mahdi; Manoj Tiwari; G. G. Agarwal

2009-01-01

235

Sequences Of Amino Acids For Human Serum Albumin  

NASA Technical Reports Server (NTRS)

Sequences of amino acids defined for use in making polypeptides one-third to one-sixth as large as parent human serum albumin molecule. Smaller, chemically stable peptides have diverse applications including service as artificial human serum and as active components of biosensors and chromatographic matrices. In applications involving production of artificial sera from new sequences, little or no concern about viral contaminants. Smaller genetically engineered polypeptides more easily expressed and produced in large quantities, making commercial isolation and production more feasible and profitable.

Carter, Daniel C.

1992-01-01

236

Serum Metabolomic Biomarkers of Dementia  

PubMed Central

Aims: This study compared serum metabolites of demented patients (Alzheimer's disease and vascular dementia) and controls, and explored serum metabolite profiles of nondemented individuals 5 years preceding the diagnosis. Methods: Cognitively healthy participants were followed up for 5-20 years. Cognitive assessment, serum sampling, and diagnosis were completed every 5 years. Multivariate analyses were conducted on the metabolite profiles generated by gas chromatography/time-of-flight mass spectrometry. Results: A significant group separation was found between demented patients and controls, and between incident cases and controls. Metabolites that contributed in both analyses were 3,4-dihydroxybutanoic acid, docosapentaenoic acid, and uric acid. Conclusions: Serum metabolite profiles are altered in demented patients, and detectable up to 5 years preceding the diagnosis. Blood sampling can make an important contribution to the early prediction of conversion to dementia.

Mousavi, Malahat; Jonsson, Par; Antti, Henrik; Adolfsson, Rolf; Nordin, Annelie; Bergdahl, Jan; Eriksson, Kare; Moritz, Thomas; Nilsson, Lars-Goran; Nyberg, Lars

2014-01-01

237

Development and evaluation of a mechanistic bioconcentration model for ionogenic organic chemicals in fish.  

PubMed

A mechanistic mass balance bioconcentration model is developed and parameterized for ionogenic organic chemicals (IOCs) in fish and evaluated against a compilation of empirical bioconcentration factors (BCFs). The model is subsequently applied to a set of perfluoroalkyl acids. Key aspects of model development include revised methods to estimate the chemical absorption efficiency of IOCs at the respiratory surface (E(W) ) and the use of distribution ratios to characterize the overall sorption capacity of the organism. Membrane-water distribution ratios (D(MW) ) are used to characterize sorption to phospholipids instead of only considering the octanol-water distribution ratio (D(OW) ). Modeled BCFs are well correlated with the observations (e.g., r(2) ?= 0.68 and 0.75 for organic acids and bases, respectively) and accurate to within a factor of three on average. Model prediction errors appear to be largely the result of uncertainties in the biotransformation rate constant (k(M) ) estimates and the generic approaches for estimating sorption capacity (e.g., D(MW) ). Model performance for the set of perfluoroalkyl acids considered is highly dependent on the input parameters describing hydrophobicity (i.e., log K(OW) of the neutral form). The model applications broadly support the hypothesis that phospholipids contribute substantially to the sorption capacity of fish, particularly for compounds that exhibit a high degree of ionization at biologically relevant pH. Additional empirical data on biotransformation and sorption to phospholipids and subsequent incorporation into property estimation approaches (e.g., k(M) , D(MW) ) are priorities with respect to improving model performance. PMID:23023933

Armitage, James M; Arnot, Jon A; Wania, Frank; Mackay, Don

2013-01-01

238

ACTIVATION ASSAY FOR PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR- ALPHA (PPARÁ) BY PERFLUOROALKYL ACIDS (PFAAS) IN COS-1 CELLS  

EPA Science Inventory

PFAAs have been found to elicit various physiological effects including peroxisome proliferation, indicating the mechanism of action for these chemicals could involve PPAR. This study investigates the ability of PFAAs to bind and activate mouse and human PPAR? in COS-1 cell...

239

Perfluoroalkyl substances in soft tissues and tail feathers of Belgian barn owls (Tyto alba) using statistical methods for left-censored data to handle non-detects.  

PubMed

Perfluoroalkyl substances (PFASs) were investigated in tail feathers and soft tissues (liver, muscle, preen gland and adipose tissue) of barn owl (Tyto alba) road-kill victims (n=15) collected in the province of Antwerp (Belgium). A major PFAS producing facility is located in the Antwerp area and levels of PFASs in biota from that region have been found to be very high in previous studies. We aimed to investigate for the first time the main sources of PFASs in feathers of a terrestrial bird species. Throughout this study, we have used statistical methods for left-censored data to cope with levels below the limit of detection (LOD), instead of traditional, potentially biased, substitution methods. Perfluorooctane sulfonate (PFOS) was detected in all tissues (range: 11ng/g ww in muscle-1208ng/g ww in preen oil) and in tail feathers (<2.2-56.6ng/g ww). Perfluorooctanoate (PFOA) was measured at high levels in feathers (<14-670ng/g ww), but not in tissues (more than 50%

Jaspers, Veerle L B; Herzke, Dorte; Eulaers, Igor; Gillespie, Brenda W; Eens, Marcel

2013-02-01

240

Effects of perfluoroalkyl compounds on mRNA expression levels of thyroid hormone-responsive genes in primary cultures of avian neuronal cells.  

PubMed

There is growing interest in assessing the neurotoxic and endocrine disrupting potential of perfluoroalkyl compounds (PFCs). Several studies have reported in vitro and in vivo effects related to neuronal development, neural cell differentiation, prenatal and postnatal development and behavior. PFC exposure altered hormone levels and the expression of hormone-responsive genes in mammalian and aquatic species. This study is the first to assess the effects of PFCs on messenger RNA (mRNA) expression in primary cultures of neuronal cells in two avian species: the domestic chicken (Gallus domesticus) and herring gull (Larus argentatus). The following thyroid hormone (TH)-responsive genes were examined using real-time reverse transcription-PCR: type II iodothyronine 5'-deiodinase (D2), D3, transthyretin (TTR), neurogranin (RC3), octamer motif-binding factor (Oct-1), and myelin basic protein. Several PFCs altered the mRNA expression levels of genes associated with the TH pathway in avian neuronal cells. Short-chained PFCs (less than eight carbons) altered the expression of TH-responsive genes (D2, D3, TTR, and RC3) in chicken embryonic neuronal cells to a greater extent than long-chained PFCs (more than or equal to eight carbons). Variable transcriptional changes were observed in herring gull embryonic neuronal cells exposed to short-chained PFCs; mRNA levels of Oct-1 and RC3 were upregulated. This is the first study to report that PFC exposure alters mRNA expression in primary cultures of avian neuronal cells and may provide insight into the possible mechanisms of action of PFCs in the avian brain. PMID:21212296

Vongphachan, Viengtha; Cassone, Cristina G; Wu, Dongmei; Chiu, Suzanne; Crump, Doug; Kennedy, Sean W

2011-04-01

241

Validation of a screening method based on liquid chromatography coupled to high-resolution mass spectrometry for analysis of perfluoroalkylated substances in biota.  

PubMed

A screening method for analysis of perfluoroalkylated substances (PFAS) in biota samples has been developed and validated using liver samples from polar cod (Boreogadus saida) and glaucous gull (Larus hyperboreus). The method was based on extraction of target compounds from homogenised samples into the solvent mixture used as mobile phase in high-performance liquid chromatography (HPLC), i.e. methanol/water (50:50; 2 mM ammonium acetate). The extract was filtered and directly injected into a HPLC/time-of-flight mass spectrometry (TOF-MS) system. Quantification was performed using 7H-perfluoroheptanoic acid as internal standard and a calibration standard solution dissolved in sample extract for each matrix type (matrix-matched calibration standard). The method is very time and cost efficient. Except for long-chain compounds and perfluorooctane sulfonamide (which cannot be covered by this method), recoveries were between 60% and 115% and method detection limits were in the range 0.04-1.3 ng/g wet weight. Blank values could be neglected with the exception of perfluorooctane sulfonate (PFOS), perfluorohexanoic acid (PFHxA) and perfluorooctanoic acid (PFOA). One of the major challenges in PFAS analysis is ionisation disturbance by co-eluting matrix in the ion source of the mass spectrometer. Both matrix and analyte specific signal enhancement and suppression was observed and quantified. Repeated extractions (n = 3) gave relative standard deviations (RSD) <35% for all PFAS. Accuracy was examined by comparing the screening method to the generally applied ion pair extraction (IPE) method. PFAS concentration values of a glaucous gull liver sample deviated by less than 30% for the two methods, provided that matrix-matched calibration standards were employed in both methods. PMID:16038211

Berger, Urs; Haukås, Marianne

2005-07-22

242

Activation of mouse and human peroxisome proliferator-activated receptor alpha by perfluoroalkyl acids of different functional groups and chain lengths.  

PubMed

Perfluoroalkyl acids (PFAAs) are surfactants used in consumer products and persist in the environment. Some PFAAs elicit adverse effects on rodent development and survival. PFAAs can activate peroxisome proliferator-activated receptor alpha (PPARalpha) and may act via PPARalpha to produce some of their effects. This study evaluated the ability of numerous PFAAs to induce mouse and human PPARalpha activity in a transiently transfected COS-1 cell assay. COS-1 cells were transfected with either a mouse or human PPARalpha receptor-luciferase reporter plasmid. After 24 h, cells were exposed to either negative controls (water or dimethyl sulfoxide, 0.1%); positive control (WY-14643, PPARalpha agonist); perfluorooctanoic acid or perfluorononanoic acid at 0.5-100 microM; perfluorobutanoic acid, perfluorohexanoic acid, perfluorohexane sulfonate, or perfluorodecanoic acid (PFDA) at 5-100 microM; or perfluorobutane sulfonate or perfluorooctane sulfonate at 1-250 microM. After 24 h of exposure, luciferase activity from the plasmid was measured. Each PFAA activated both mouse and human PPARalpha in a concentration-dependent fashion, except PFDA with human PPARalpha. Activation of PPARalpha by PFAA carboxylates was positively correlated with carbon chain length, up to C9. PPARalpha activity was higher in response to carboxylates compared to sulfonates. Activation of mouse PPARalpha was generally higher compared to that of human PPARalpha. We conclude that, in general, (1) PFAAs of increasing carbon backbone chain lengths induce increasing activity of the mouse and human PPARalpha with a few exceptions, (2) PFAA carboxylates are stronger activators of mouse and human PPARalpha than PFAA sulfonates, and (3) in most cases, the mouse PPARalpha appears to be more sensitive to PFAAs than the human PPARalpha in this model. PMID:18713766

Wolf, Cynthia J; Takacs, Margy L; Schmid, Judith E; Lau, Christopher; Abbott, Barbara D

2008-11-01

243

Effects of Perfluoroalkyl Compounds on mRNA Expression Levels of Thyroid Hormone-Responsive Genes in Primary Cultures of Avian Neuronal Cells  

PubMed Central

There is growing interest in assessing the neurotoxic and endocrine disrupting potential of perfluoroalkyl compounds (PFCs). Several studies have reported in vitro and in vivo effects related to neuronal development, neural cell differentiation, prenatal and postnatal development and behavior. PFC exposure altered hormone levels and the expression of hormone-responsive genes in mammalian and aquatic species. This study is the first to assess the effects of PFCs on messenger RNA (mRNA) expression in primary cultures of neuronal cells in two avian species: the domestic chicken (Gallus domesticus) and herring gull (Larus argentatus). The following thyroid hormone (TH)–responsive genes were examined using real-time reverse transcription-PCR: type II iodothyronine 5?-deiodinase (D2), D3, transthyretin (TTR), neurogranin (RC3), octamer motif–binding factor (Oct-1), and myelin basic protein. Several PFCs altered the mRNA expression levels of genes associated with the TH pathway in avian neuronal cells. Short-chained PFCs (less than eight carbons) altered the expression of TH-responsive genes (D2, D3, TTR, and RC3) in chicken embryonic neuronal cells to a greater extent than long-chained PFCs (more than or equal to eight carbons). Variable transcriptional changes were observed in herring gull embryonic neuronal cells exposed to short-chained PFCs; mRNA levels of Oct-1 and RC3 were upregulated. This is the first study to report that PFC exposure alters mRNA expression in primary cultures of avian neuronal cells and may provide insight into the possible mechanisms of action of PFCs in the avian brain. PMID:21212296

Vongphachan, Viengtha; Cassone, Cristina G.; Wu, Dongmei; Chiu, Suzanne; Crump, Doug; Kennedy, Sean W.

2011-01-01

244

Serum Matrix Metalloproteinase Levels in Patients Exposed to Sulfur Mustard  

PubMed Central

Background: Matrix metalloproteinases (MMPs) are a group of endopeptidases which comprised of various types. These proteolytic enzymes are zinc-dependent and play role in degradation of extracellular matrix (ECM). Various types of cells such as macrophages, fibroblasts, neutrophils, synovial cells and some epithelial cells secrete MMPs. According to previous studies on bronchiolitis and respiratory tract lesions in these patients and unknown pathophysiology mechanism up to date, this cross–sectional study was performed. Objectives: The aim of this study was to compare the serum MMP level in patients with chemical injuries and normal people and also determine the role of these parameters in pulmonary disorders . Materials and Methods: In this cross–sectional study, 25 Iranian patients exposed to the sulfur mustard and 25 unexposed participants as the control group were enrolled. Serum samples were collected from two groups and stored at -70?C until the measurement of MMPs and TIMPs. ELISA kit was used for measurement of MMP and TIMP based on the kit's instruction. For validations in measurement, all samples were analyzed duplicate and in some cases triplicate. Results: The mean level of MMP-9 in serum of chemically-injured group was 1592.42 and this amount in normal group was 679.72 .So there was a significant difference between two groups (P = 0.001) and the mean level of MMP-8 in serum of patients group was 49.10 and in normal group was 35.53. Then there was no significant difference between two groups (P = 0.197). The mean levels of MMP-1 and MMP-2 was not significantly different (P value > 0.05) in the patient and normal groups. And also the mean levels of TIMP-1 and TIMP-2 was not significantly different (P > 0.05) in the patients and normal groups. Conclusions: In summary, serum MMPs in chemically-injured has shown no significant difference with normal people except for the MMP-9. PMID:24829780

Shohrati, Majid; Haji Hosseini, Reza; Esfandiari, Malek Ashtar; Najafian, Nastaran; Najafian, Bita; Golbedagh, Abbas

2014-01-01

245

Evaluation of serum and salivary lipid profile: A correlative study  

PubMed Central

Context: The correlation of serum and salivary lipid profile has been poorly characterized. The most commonly used laboratory diagnostic procedures for lipid profile involve analysis of cellular and chemical constituents of blood/plasma. As a diagnostic aid, saliva offers many advantages over serum. Aims: To evaluate and compare the serum and salivary lipid profile levels in healthy individuals and to validate the role of saliva as a non-invasive diagnostic tool for assessing lipid profile. Settings and Design: The present study was a prospective study. Materials and Methods: A total of 100 healthy study subjects who had no complaint or any major illness in recent past were selected. The parameters assessed included serum and salivary: total cholesterol (TC), high-density lipoprotein-cholesterol (HDLC), low-density lipoprotein-cholesterol (LDLC), very low-density lipoprotein-cholesterol (VLDLC) and triglycerides (TGL). Statistical Analysis Used: Evaluation of results and statistical analysis was carried out using descriptive, correlation and regression analysis. Results: There was a moderate level of correlation between serum and salivary TC, TGL, HDLC and VLDLC and there was a low and quite small correlation between serum and salivary LDLC. For all the five parameters assessed as a part of lipid profile, the correlation coefficients were highly significant statistically and also, with an increase in the serum mean values, corresponding increase in the saliva mean values for all the five parameters was noted. Conclusions: From the present study we conclude that saliva can be used as a non-invasive diagnostic tool for assessing lipid profile. PMID:24959029

Singh, Simranjit; Ramesh, Venkatapathy; Oza, Nirima; Balamurali, Pennagaram Dhanasekaran; Prashad, Karthikshree Vishnu; Balakrishnan, Premalatha

2014-01-01

246

ELECTROPHORETIC HOMOGENEITY OF PREGNANT MARE SERUM GONADOTROPHIN  

PubMed Central

A highly purified and potent gonadotrophin in pregnant mare serum has been prepared. The preparation has been shown to be electrophoretically homogeneous in the Tiselius apparatus. The mobilities of the substance have been determined over a wide range of hydrogen ion concentrations. The isoelectric point lies at pH 2.60–2.65 and the value of See PDF for Equation is 4.0 x 10–5. Some chemical constituents have been studied. From the tryptophane and tyrosine content the molecular weight of the hormone is estimated to be 30,000. The hormone has been subjected to acetylation by ketene in aqueous solution at room temperature and the result suggests again the essentiality of free amino groups for the biological activity of the hormone. In this respect it is to be contrasted with human chorionic gonadotrophin. PMID:19873189

Li, Choh Hao; Evans, Herbert M.; Wonder, Donald H.

1940-01-01

247

ELECTROPHORETIC HOMOGENEITY OF PREGNANT MARE SERUM GONADOTROPHIN.  

PubMed

A highly purified and potent gonadotrophin in pregnant mare serum has been prepared. The preparation has been shown to be electrophoretically homogeneous in the Tiselius apparatus. The mobilities of the substance have been determined over a wide range of hydrogen ion concentrations. The isoelectric point lies at pH 2.60-2.65 and the value of See PDF for Equation is 4.0 x 10(-5). Some chemical constituents have been studied. From the tryptophane and tyrosine content the molecular weight of the hormone is estimated to be 30,000. The hormone has been subjected to acetylation by ketene in aqueous solution at room temperature and the result suggests again the essentiality of free amino groups for the biological activity of the hormone. In this respect it is to be contrasted with human chorionic gonadotrophin. PMID:19873189

Li, C H; Evans, H M; Wonder, D H

1940-07-20

248

Integrated Risk Index of Chemical Aquatic Pollution (IRICAP): case studies in Iberian rivers.  

PubMed

The hazard of chemical compounds can be prioritized according to their PBT (persistence, bioaccumulation, toxicity) properties by using Self-Organizing Maps (SOM). The objective of the present study was to develop an Integrated Risk Index of Chemical Aquatic Pollution (IRICAP), useful to evaluate the risk associated to the exposure of chemical mixtures contained in river waters. Four Spanish river basins were considered as case-studies: Llobregat, Ebro, Jucar and Guadalquivir. A SOM-based hazard index (HI) was estimated for 205 organic compounds. IRICAP was calculated as the product of the HI by the concentration of each pollutant, and the results of all substances were aggregated. Finally, Pareto distribution was applied to the ranked lists of compounds in each site to prioritize those chemicals with the most significant incidence on the IRICAP. According to the HI outcomes, perfluoroalkyl substances, as well as specific illicit drugs and UV filters, were among the most hazardous compounds. Xylazine was identified as one of the chemicals with the highest contribution to the total IRICAP value in the different river basins, together with other pharmaceutical products such as loratadine and azaperol. These organic compounds should be proposed as target chemicals in the implementation of monitoring programs by regulatory organizations. PMID:23810233

Fàbrega, Francesc; Marquès, Montse; Ginebreda, Antoni; Kuzmanovic, Maja; Barceló, Damià; Schuhmacher, Marta; Domingo, José L; Nadal, Martí

2013-12-15

249

ALLOTYPY OF RABBIT SERUM PROTEINS  

PubMed Central

The injection into one rabbit (with Freund's adjuvants) of a specific precipitate made with antibodies from the serum of another rabbit is usually followed by the appearance in the serum of the first rabbit of antibodies which precipitate the serum of certain rabbits but not of others. It was found that the antigen (or one of the antigens) concerned in the reaction of these anti rabbit serum antibodies with rabbit sera had an antibody function, and was therefore a protein. It was concluded that at least one serum protein antigen, the specificity of which so far has been considered to be uniform throughout the animal species, can instead be present in different individuals as different forms or allotypes with somewhat different antigenic specificities. A large number of rabbit sera were allowed to react with a large number of rabbit immune sera. The gel method of immunochemical analysis made it possible to enumerate the allotypes that took part in each reaction. In addition, the technique mainly used (simple diffusion in separate tubes) made it possible to recognize the presence of one given allotype by the mere aspect of the precipitation zone in the reaction of one suitable immune serum with any serum in which the concerned allotype occurred. Neighboring reactions of sera, in contact with each other and with the suitable immune serum, in suitable cells easily constructed in the laboratory, were carried out occasionally and, each time, their results agreed with the previous identification. The analysis of the reactions in tubes lead to a list of seven allotypes designated by a, b, c, d, e, f, and g, of which two or more (e not included) were contained in almost every serum. The specific conditions necessary for antibody formation against an allotype are its absence from the serum of the immunized animal and, except in the case of cross-reactivity, its presence in the immunizing material. When these necessary conditions are fulfilled for several allotypes at the same time, their competition in the immunization seems to favor the allotype present at the highest concentration. The individuality of six of the listed allotypes has been discussed independently of the part of their specificity that may be common to all the allotypes of one given protein antigen in all the individuals of the same animal species. A cross-reaction of the anti f rabbit antibodies with allotype g has been observed. When two allotypic specificities were detected in one serum, attempts were made to find whether they were carried by two allotypes, i.e. by two distinct kinds of molecules, instead of being the manifestation of two "allotypic patterns" present on the same molecules. The presence of several allotypes in the immune sera made it often impossible to find definitive answers in this regard. However, for a limited number of cases of two allotypic specificities present in one serum, it could be demonstrated that at least a large proportion (if not the totality) of the two allotypes were independent of each other. No sign of a systematic coexistence of two allotypic patterns on the same molecules has been observed to date. PMID:13731716

Oudin, Jacques

1960-01-01

250

Adsorption of bovine serum albumin on nanosized magnetic particles  

Microsoft Academic Search

Adsorption of bovine serum albumin (BSA) on nanosized magnetic particles (Fe3O4) was carried out in the presence of carbodiimide. The equilibrium and kinetics of the adsorption process were studied. Nanosized magnetic particles (Fe3O4) were prepared by the chemical precipitation method using Fe2+, Fe3+ salts, and ammonium hydroxide under a nitrogen atmosphere. Characterizations of magnetic particles were carried out using transmission

Z. G. Peng; K. Hidajat; M. S. Uddin

2004-01-01

251

Evaluation of potential health effects associated with serum polychlorinated biphenyl levels  

SciTech Connect

In late 1983, we conducted a cross-sectional epidemiologic study to evaluate persons at risk of exposure to three chemical waste sites by comparing clinical disease end points and clinical chemistry parameters with serum polychlorinated biphenyls (PCB) levels. A total of 106 individuals participated in the study. The only statistically significant finding in regard to self-reported, physician-diagnosed health problems was a dose-response relationship between serum PCB levels and the occurrence of high blood pressure; however, this association failed to achieve statistical significance when we controlled for possible confounding effects of both age and smoking. Serum triglyceride and cholesterol levels were also higher in the group with elevated serum PCBs; additionally, there were isolated statistically significant correlations of serum aspartate aminotransferase (SGOT) with serum lipid fraction-adjusted PCB level and serum albumin and total bilirubin with serum PCB level. Although the ranges of serum levels reported herein from exposures to PCBs in the general environment are lower than those that have been associated with acute symptoms or illness in other studies, whether these levels are associated with long-term health risks is not known. Associations of such chronic, low-dose exposures with observable health effects as suggested by this study must be evaluated further before any final conclusions can be drawn.

Stehr-Green, P.A.; Welty, E.; Steele, G.; Steinberg, K.

1986-12-01

252

Chemical Mechanical Planarization- Chemical  

NSDL National Science Digital Library

This website includes an animation which illustrates the chemical action of slurry in the chemical-mechanical planarization process. Objective: Explain the mechanical and chemical steps in the CMP process. This simulation is from Module 068 of the Process & Equipment III Cluster of the MATEC Module Library (MML). Find this animation under the section "Process & Equipment III." To view other clusters or for more information about the MML visit http://matec.org/ps/library3/process_I.shtmlKey Phrase: MATEC Animation

2012-12-07

253

Specific antioxidant properties of human serum albumin  

PubMed Central

Human serum albumin (HSA) has been used for a long time as a resuscitation fluid in critically ill patients. It is known to exert several important physiological and pharmacological functions. Among them, the antioxidant properties seem to be of paramount importance as they may be implied in the potential beneficial effects that have been observed in the critical care and hepatological settings. The specific antioxidant functions of the protein are closely related to its structure. Indeed, they are due to its multiple ligand-binding capacities and free radical-trapping properties. The HSA molecule can undergo various structural changes modifying its conformation and hence its binding properties and redox state. Such chemical modifications can occur during bioprocesses and storage conditions of the commercial HSA solutions, resulting in heterogeneous solutions for infusion. In this review, we explore the mechanisms that are responsible for the specific antioxidant properties of HSA in its native form, chemically modified forms, and commercial formulations. To conclude, we discuss the implication of this recent literature for future clinical trials using albumin as a drug and for elucidating the effects of HSA infusion in critically ill patients. PMID:23414610

2013-01-01

254

Predictors of Serum Chlorinated Pesticide Concentrations among Prepubertal Russian Boys  

PubMed Central

Background: Few studies have evaluated predictors of childhood exposure to organochlorine pesticides (OCPs), a class of lipophilic persistent chemicals. Objectives: Our goal was to identify predictors of serum OCP concentrations—hexachlorobenzene (HCB), ?-hexachlorocyclohexane (?-HCH), and p,p-dichlorodiphenyldichloroethylene (p,p´-DDE)—among boys in Chapaevsk, Russia. Methods: Between 2003 and 2005, 499 boys 8–9 years of age were recruited in a prospective cohort. The initial study visit included a physical examination; blood collection; health, lifestyle, and food-frequency questionnaires; and determination of residential distance from a local factory complex that produced HCB and ?-HCH. Fasting serum samples were analyzed for OCPs at the U.S. Centers for Disease Control and Prevention. General linear regression models were used to identify predictors of the boys’ serum HCB, ?-HCH, and p,p´-DDE concentrations. Results: Among 355 boys with OCP measurements, median serum HCB, ?-HCH, and p,p´-DDE concentrations were 158, 167, and 284 ng/g lipid, respectively. Lower body mass index, longer breastfeeding duration, and local dairy consumption were associated with higher concentrations of OCPs. Boys who lived < 2 km from the factory complex had 64% (95% CI: 37, 96) and 57% (95% CI: 32, 87) higher mean HCB and ?-HCH concentrations, respectively, than boys who lived ? 5 km away. Living > 3 years in Chapaevsk predicted higher ?-HCH concentrations, and having parents who lacked a high school education predicted higher p,p´-DDE concentrations. Conclusions: Among this cohort of prepubertal Russian boys, predictors of serum OCPs included consumption of local dairy products, longer local residence, and residential proximity to the local factory complex. Citation: Lam T, Williams PL, Burns JS, Sergeyev O, Korrick SA, Lee MM, Birnbaum LS, Revich B, Altshul LM, Patterson DG Jr, Turner WE, Hauser R. 2013. Predictors of serum chlorinated pesticide concentrations among prepubertal Russian boys. Environ Health Perspect 121:1372–1377;?http://dx.doi.org/10.1289/ehp.1306480 PMID:23955839

Williams, Paige L.; Burns, Jane S.; Sergeyev, Oleg; Korrick, Susan A.; Lee, Mary M.; Birnbaum, Linda S.; Revich, Boris; Altshul, Larisa M.; Patterson, Donald G.; Turner, Wayman E.; Hauser, Russ

2013-01-01

255

Photocatalytic degradation of some methyl perfluoroalkyl ethers on TiO{sub 2} particles in air: The dependence on the dark-adsorption, the products, and the implication for a possible tropospheric sink  

SciTech Connect

Fluorinated ethers are potential substitutes for hydrochlorofluorocarbons and hydrofluorocarbons. Their lifetime through each removal process should be evaluated to estimate their effects on the environment as GWP. Photocatalytic reactions on titanium dioxide particles were examined as a possible tropospheric sink through heterogeneous processes on particulate matters. Photocatalytic degradation of three kinds of methyl perfluoroalkyl ethers in air takes place on titanium dioxide particles at ambient temperature under illumination of light. Main products are carbon dioxide and carbonyl fluoride. The initial photodegradation rate is proportional to the square root of the amount of fluorinated ethers adsorbed in the dark, while the adsorption shows a Henry type adsorption curve. A tentative reaction scheme via H atom abstraction and a formic ester is proposed. The kinetic data indicates that the heterogeneous photodegradation could proceed with a rate enough to serve as a tropospheric sink of fluorinated ethers even in such low density of titanium dioxide particles as in the environment.

Kutsuna, Shuzo; Takeuchi, Koji; Ibusuki, Takashi [National Inst. for Resources and Environment, Tsukuba, Ibaraki (Japan). Global Warming Control Dept.] [National Inst. for Resources and Environment, Tsukuba, Ibaraki (Japan). Global Warming Control Dept.; Toma, Mitsuhiro [Research Inst. of Innovative Technology for the Earth, Tsukuba, Ibaraki (Japan). New Refrigerants Development Group] [Research Inst. of Innovative Technology for the Earth, Tsukuba, Ibaraki (Japan). New Refrigerants Development Group

1999-04-01

256

Modulation of. beta. -adrenergic response in rat brain astrocytes by serum and hormones  

SciTech Connect

Purified astrocyte cultures from neonatal rat cerebrum respond to isoproterenol, a ..beta..-adrenergic agonist, with a transient rise in cAMP production. This astroglial property was regulated by serum, a chemically defined medium (serum-free medium plus hydrocortisone, putrescine, prostaglandin F/sub 2/, insulin, and fibroblast growth factor) and epidermal growth factor. Compared to astrocytes grown in serum-supplemented medium, astrocytes grown in the chemically defined medium were nonresponsive to isoproterenol stimulation, and this difference did not appear to be due to selection of a subpopulation of cells by either medium. The data suggest that a decreased ..beta..-adrenergic receptor number and an increased degradation of cAMP may account for the reduced response to ..beta..-adrenergic stimulation. The nonresponsive state of astrocytes in the defined medium was reversible when the medium was replaced with serum-supplemented medium. An active substance(s) in serum was responsible for restoring the responsiveness of astrocytes. Each of the five components of the defined medium had little effect by itself; however, together they acted synergistically to desensitize astrocytes to ..beta..-adrenergic stimulation. On the other hand, epidermal growth factor, a potent mitogen for astrocytes, was very competent by itself in reducing the cAMP response of astrocytes to ..beta..-adrenergic stimulation. Thus purified astrocytes grown in the chemically defined medium appear to be a good model for the study of hormonal interactions and of serum factors which may modulate the ..beta..-adrenergic response.

Wu, D.K.; Morrison, R.S.; de Vellis, J.

1985-01-01

257

Dark Immunofluorescence: Correlation with Serum Immunoglobulin Abnormalities?  

PubMed Central

Occasional serum samples (<0.5%) tested by indirect immunofluorescence showed less fluorescence than did negative-control serum. A retrospective review of these patients' serum immunoglobulins revealed a high percentage of abnormalities (71%, versus 22% of controls). We suggest that this observation should be reported when seen and that the clinician should be alerted to an association with immunoglobulin abnormalities. PMID:16971516

List, J.; Buckland, M. S.; Thobhani, B.; Sheed, C. J.; Mann, J. C.; Claxton, M.; Heelan, B.

2006-01-01

258

Zwitterionic, cationic, and anionic fluorinated chemicals in aqueous film forming foam formulations and groundwater from U.S. military bases by nonaqueous large-volume injection HPLC-MS/MS.  

PubMed

A new analytical method was developed to quantify 26 newly-identified and 21 legacy (e.g. perfluoroalkyl carboxylates, perfluoroalkyl sulfonates, and fluorotelomer sulfonates) per and polyfluorinated alkyl substances (PFAS) in groundwater and aqueous film forming foam (AFFF) formulations. Prior to analysis, AFFF formulations were diluted into methanol and PFAS in groundwater were micro liquid-liquid extracted. Methanolic dilutions of AFFF formulations and groundwater extracts were analyzed by large-volume injection (900 ?L) high-performance liquid chromatography tandem mass spectrometry. Orthogonal chromatography was performed using cation exchange (silica) and anion exchange (propylamine) guard columns connected in series to a reverse-phase (C18) analytical column. Method detection limits for PFAS in groundwater ranged from 0.71 ng/L to 67 ng/L, and whole-method accuracy ranged from 96% to 106% for analytes for which matched authentic analytical standards were available. For analytes without authentic analytical standards, whole-method accuracy ranged from 78 % to 144 %, and whole-method precision was less than 15 % relative standard deviation for all analytes. A demonstration of the method on groundwater samples from five military bases revealed eight of the 26 newly-identified PFAS present at concentrations up to 6900 ng/L. The newly-identified PFAS represent a minor fraction of the fluorinated chemicals in groundwater relative to legacy PFAS. The profiles of PFAS in groundwater differ from those found in fluorotelomer- and electrofluorination-based AFFF formulations, which potentially indicates environmental transformation of PFAS. PMID:23590254

Backe, Will J; Day, Thomas C; Field, Jennifer A

2013-05-21

259

Population based study on serum ionised calcium, serum parathyroid hormone, and blood pressure. The Tromso study  

Microsoft Academic Search

Objective: To study associations between serum ionised calcium, serum parathyroid hormone (PTH) and blood pressure. Design: A population based, cross-sectional study was used. Methods: Blood pressure, body mass index, serum ionised calcium and serum PTH were measured in 460 males and 486 females in the Tromsø study in 1994\\/1995. None were on medication for hypertension. The data were analysed with

Rolf Jorde; Kaare H Bønaa; Johan Sundsfjord

1999-01-01

260

Alternatives to the Use of Fetal Bovine Serum: Serum-free Cell Culture  

Microsoft Academic Search

Summary Serum is commonly used as a supplement to cell culture media. It provides a broad spectrum of macromolecules, carrier proteins for lipoid substances and trace elements, attachment and spreading factors, low molecular weight nutrients, and hormones and growth factors. The most widely used animal serum supplement is fetal bovine serum, FBS. Since serum in general is an ill-defined component

Gerhard Gstraunthaler

261

Hematology and serum chemistry of the island spotted skunk on Santa Cruz Island.  

PubMed

We determined serum biochemistry and hematologic values for island spotted skunks (Spilogale gracilis amphiala) on Santa Cruz Island (California, USA). Samples were collected from island spotted skunks chemically restrained with ketamine hydrochloride and acepromazine in August 1999 (dry season) and from skunks manually restrained in August 2000 (dry season) and January 2001 (wet season). One parameter, glucose, significantly differed with season, with higher levels during the wet season. Serum chemistry and hematologic profiles suggest that method of restraint (manual or chemical), as well as other methodologic details, may influence blood characteristics in the island spotted skunk. PMID:12910779

Crooks, Kevin R; Garcelon, D K; Scott, Cheryl A; Wilcox, Jeffery T; Timm, Steven F; Van Vuren, Dirk H

2003-04-01

262

Reduction of blood serum cholesterol  

NASA Technical Reports Server (NTRS)

By feeding a human subject as the sole source of sustenance a defined diet wherein the carbohydrate consists substantially entirely of glucose, maltose or a polysaccharide of glucose, the blood serum cholesterol level of the human subject is substantially reduced. If 25 percent of the carbohydrate is subsequently supplied in the form of sucrose, an immediate increase from the reduced level is observed. The remainder of the defined diet normally includes a source of amino acids, such as protein or a protein hydrolysate, vitamins, minerals and a source of essential fatty acid.

Winitz, M. (inventor)

1974-01-01

263

Effect of cord blood serum on ex vivo human limbal epithelial cell culture.  

PubMed

Limbal cell transplantation is an efficacious procedure for rehabilitation of visual acuity in patients with severe ocular surface disorders. Cultivation of limbal epithelial stem cell with fetal bovine serum for transplantation has been a promising treatment for reconstructing the ocular surface in severe limbal stem cell deficiency caused by Steven Johnson syndrome, chemical or thermal injury. This technique of "cell therapy" has been accepted worldwide but the cost of cultivating the cells for transplantation is high. The objective of this study was to investigate the effect of cord blood serum in place of fetal bovine serum on the growth of human limbal epithelial cell culture. Our group has experimented with human cord blood serum which was obtained free of cost from willing donors. The use of human cord blood serum in place of fetal bovine serum for ex vivo culture of limbal stem cell has helped us in reducing the cost of culture. Fresh human limbal tissues from donor cadavers were cultured on intact and denuded amniotic membrane. Cells were proliferated in vitro with cell culture media containing human cord blood serum. Reverse transcription-polymerase chain reaction and immunofluorescence cytochemistry of cultured human limbal epithelial stem cell was done for characterization of the cells. PMID:24596943

Chakraborty, Anindita; Dutta, Jayanta; Das, Sumantra; Datta, Himadri

2012-12-01

264

Novel Utilization of Serum in Tissue Decellularization  

PubMed Central

Decellularization of native tissues is a promising technique with numerous applications in tissue engineering and regenerative medicine. However, there are various limitations of currently available decellularization methods, such as alteration of extracellular matrix mechanics and restricted use on certain tissues. This study was conducted to explore the effect of serum on the decellularization of various types of tissues. Fetal bovine serum–containing cell culture medium endothelial growth media-2 removed DNA but not cellular ?-actin from human umbilical artery after detergent treatment, without compromising the tissue mechanical strength assessed by burst pressure. In addition, the effect of serum-containing endothelial growth media-2 on DNA removal was replicated in other types of tissues such as tissue-engineered vessels and myocardium. Other types of serum, including human serum, were also shown to remove DNA from detergent-pretreated tissues. In conclusion, we describe a novel utilization of serum that may have broad applications in tissue decellularization. PMID:19419244

Gui, Liqiong; Chan, Stephen A.; Breuer, Christopher K.

2010-01-01

265

Serum Dihydrolipoamide Dehydrogenase Is a Labile Enzyme  

PubMed Central

Dihydrolipoamide dehydrogenase (DLDH) is a multifunctional oxidoreductase and is well known as an essential component of four mammalian mitochondrial multienzyme complexes: pyruvate dehydrogenase, ?-ketoglutarate dehydrogenase, branched chain ?-keto acid dehydrogenase, and the glycine cleavage system. However, existence of extracellular DLDH in mammals, if any, has not been clearly defined. The present article reports identification and biochemical characterization of serum DLDH. Proteomic analysis of rat serum using blue native polyacrylamide gel electrophoresis (BN-PAGE) and mass spectrometry peptide sequencing led to generation of 6 tryptic peptides in one band that matched to mitochondrial DLDH, indicating the existence of DLDH in rat serum. Measurement of enzymatic activity also indicated the existence of DLDH in human and mouse serum. Further biochemical analysis of rat serum DLDH revealed that this enzyme lacked diaphorase activity and could not be detected on Western blots probed with antibodies that recognized mitochondrial DLDH. Moreover, both ammonium sulfate fractioning and gel filtration of serum samples rendered a great loss in DLDH activity, indicating that the enzyme activity of this serum protein, unlike that of mitochondrial DLDH, is very labile. When DTT was supplemented in the buffer used for gel filtration, DLDH activity was found to be largely preserved; indicating that serum DLDH is susceptible to air-implicated inactivation. Results of the present study indicate that serum DLDH differs from mitochondrial DLDH in that it is a very labile enzyme. PMID:23646291

Yan, Liang-Jun; Thangthaeng, Nopporn; Sumien, Nathalie; Forster, Michael J.

2013-01-01

266

A new stable perfluoroalkyl radical  

SciTech Connect

This paper uses ESR spectroscopy to study the radical formed upon the gamma-irradiation of liquid perfluoro-methyl-2-pentene (PMP). The ESR spectrum of this radical shows a well resolved doublet of triplets with splitting 6.2 and 1.5 mT with additional splitting of each component by 0.25 mT. This ESR corresponds to a radical formed upon the addition of a radical r, in particlular, CF/sub 3/ to PMP.

Allayarov, S.R.; Barkalov, I.M.; Mikhailov, A.I.

1986-01-01

267

Hematology and Serum Chemistry of the Island Spotted Skunk on Santa Cruz Island  

Microsoft Academic Search

We determined serum biochemis- try and hematologic values for island spotted skunks (Spilogale gracilis amphiala) on Santa Cruz Island (California, USA). Samples were collected from island spotted skunks chemically restrained with ketamine hydrochloride and acepromazine in August 1999 (dry season) and from skunks manually restrained in August 2000 (dry season) and January 2001 (wet sea- son). One parameter, glucose, significantly

Kevin R. Crooks; D. K. Garcelon; Cheryl A. Scott; Jeffery T. Wilcox; Steven F. Timm; Dirk H. Van

2003-01-01

268

Total parenteral nutrition turbidity and clearing of serum for assay purposes  

Microsoft Academic Search

Parenteral nutrition such as Liposyn III when introduced into patients causes their serum to become milky thereby creating potentially aberrant analyses when such a medium is subjected to spectrophotometric investigation during the time period prior to the metabolic removal of the intravenously injected triglycerides. However, it is possible to alter chemical reagents by the introduction of enzymatic clearing materials, which

J. D. Artiss; B. R. Morgan; B. Zak

2002-01-01

269

Analysis of Mineral Trioxide Aggregate Surface when Set in the Presence of Fetal Bovine Serum  

Microsoft Academic Search

Understanding the chemical and physical characteristics of set mineral trioxide aggregate (MTA) surface can provide insight into its bioactivity. The purpose of this study was to describe the surface chemistry and morphology of gray and white MTA set in the presence of fetal bovine serum (FBS). Eight MTA blocks were prepared: four set in the presence of water and four

Mark C. Tingey; Peter Bush; Ming Shih Levine

2008-01-01

270

Surface Composition of Spray-Dried Particles of Bovine Serum Albumin\\/Trehalose\\/Surfactant  

Microsoft Academic Search

Purpose. To characterize via electron spectroscopy for chemical analysis(ESCA) the surface of spray-dried particles of trehalose plus aprotein (bovine serum albumin). Additionally, to show how and whythe addition of a surfactant reduces protein adsorption, and by thismechanism could reduce protein instability during spray-drying.

Michael Adler; Michael Unger; Geoffrey Lee

2000-01-01

271

VX Hydrolysis by Human Serum Paraoxonase 1: A Comparison of Experimental and Computational Results  

E-print Network

Human Serum paraoxonase 1 (HuPON1) is an enzyme that has been shown to hydrolyze a variety of chemicals including the nerve agent VX. While wildtype HuPON1 does not exhibit sufficient activity against VX to be used as an ...

Peterson, Matthew W.

272

Serum alkaline phosphatase levels associate with elevated serum C-reactive protein in chronic kidney disease  

Microsoft Academic Search

High serum alkaline phosphatase concentrations are associated with elevated serum C-reactive protein (CRP) levels in the general population. To examine whether this association is independent of serum vitamin D levels or modified in chronic kidney disease (CKD), we determined if such associations exist using data from the National Health and Nutrition Examination Survey III of 14,420 adult participants in which

Sriharsha Damera; Kalani L Raphael; Bradley C Baird; Alfred K Cheung; Tom Greene; Srinivasan Beddhu

2011-01-01

273

A comparison of the effects of estrus cow serum and fetal calf serum on in vitro  

E-print Network

A comparison of the effects of estrus cow serum and fetal calf serum on in vitro nuclear maturation% fetal calf serum (FCS) and 50 pg/ml gentamicin and then #12;transferred into the culture medium of bovine oocytes J Spiropoulos, SE Long University of Bristol, School of Veterinary Science, Department

Boyer, Edmond

274

Chemical Communication  

NSDL National Science Digital Library

A concise lesson about chemical communication in insects covering both semio and info chemicals. The site includes a short video of grape root borer moths using sex pheromone. Further links on the take the user to visual and auditory communication.

0002-11-30

275

Home Chemicals  

NSDL National Science Digital Library

This lesson provides an introduction to the occurrence and possible risks of household chemical products. Topics include some basic chemistry (how elements combine to form compounds), how chemicals are classified, and the idea of natural, as opposed to synthetic, chemicals. The lesson includes an activity in which students take an inventory of chemical products in their homes and research the possible hazards of some of them using an online resource developed by the National Institutes of Health (NIH).

Fox, Chris

276

Studies on ceruloplasmin of bovine serum  

E-print Network

....... ........23 III. The quantitative relationships of ceruloplasmin and other blood constituents ......... 29 Experimental .. ?. ?............................... 29 Results and discussion ...................... . 31 IV. The affect of comsumption of copper... glutathione of whole blood ......................................... . 43 XI. The affect of copper fertilization of pasture and cobalt treatment on the serum oxidase, activity and on the serum proteins ................... ..................... 47 LIST...

Deyoe, Charles Walter

2013-10-04

277

Dietary influences on serum lipids and lipoproteins  

Microsoft Academic Search

Substantial data are available to indicate that the diet influences serum levels of cholesterol and lipoproteins. These data are derived from studies in laboratory animals, from epidemiologic studies, and from human investigations. Most research has focused on effects of diet on serum total cholesterol concentrations. In recent years, however, attention has shifted to individual lipoproteins, Le., low density lipoproteins (LDL),

Scott M. Grundy; Margo A. Denke

278

Decreased water: increased solids: distorted serum concentrations  

Microsoft Academic Search

Serum, in which there is a pathological ratio between its percentage of water and total solids concentration is a relatively frequent occurrence in a clinical chemistry laboratory. These two factors bear an inverse relationship to each other because as the solids increase, the water decreases in fixed volumes of serum. These solid classes are comprised of proteins, lipids and crystalloids,

Bennie Zak; Joseph D Artiss

2002-01-01

279

Update and Review: Maternal Serum Screening  

Microsoft Academic Search

Maternal serum levels of alpha fetoprotein (AFP), human chorionic gonadotropin (hCG), and unconjugated estriol (uE3) can be used to screen pregnancies for neural tube defects, Down syndrome, Trisomy 18, and pregnancy complications. This article summarizes the most recent information regarding maternal serum screening, including genetic counseling issues.

Kelly E. Ormond

1997-01-01

280

Blood serum atherogenicity and coronary artery calcification.  

PubMed

The phenomenon of blood serum atherogenicity was described as the ability of human serum to induce lipid accumulation in cultured cells. The results of recent two-year prospective study in asymptomatic men provided the evidence for association between the changes in serum atherogenicity and dynamics of carotid intima-media thickness progression. The present study was undertaken to test the hypothesis that blood serum atherogenicity and its changes in dynamics may be associated with accumulation of coronary calcium in subclinical atherosclerosis. It was performed in 782 CHD-free participants of The Heinz Nixdorf RECALL (Risk Factors, Evaluation of Coronary Calcium and Lifestyle) Study, in whom blood samples have been taken at the baseline and at the end of 5-year follow-up. Opposite to the previous findings, the changes in serum atherogenicity did not correlate neither with the extent of coronary artery calcification, nor with the changes in Agatston CAC score. There was a moderate but significant rise in serum atherogenicity after 5-year followup period, and the same dynamics was observed for Agatston CAC score, but not for convenient lipid-related risk factors. The absence of association of the changes in serum atherogenicity with the changes in Agatston CAC score, along with previous findings, provides a point of view that serum-induced intracellular cholesterol accumulation is not related to the processes of calcium deposition in arterial wall, since the last one reflects the progression of already existing subclinical atherosclerotic lesions. PMID:24533940

Sobenin, Igor A; Myasoedova, Veronica A; Anisimova, Elena V; Pavlova, Xenia N; Mohlenkamp, Stefan; Schmermund, Axel; Seibel, Rainer; Berenbein, Sina; Lehmann, Nils; Moebus, Susanne; Jockel, KarlHeinz; Orekhov, Alexander N; Erbel, Raimund

2014-01-01

281

Chemical sensor  

NASA Technical Reports Server (NTRS)

A sensor for detecting a chemical substance includes an insertion element having a structure which enables insertion of the chemical substance with a resulting change in the bulk electrical characteristics of the insertion element under conditions sufficient to permit effective insertion; the change in the bulk electrical characteristics of the insertion element is detected as an indication of the presence of the chemical substance.

Rauh, R. David (Inventor)

1990-01-01

282

Chemical microsensors  

NASA Astrophysics Data System (ADS)

Recent developments are discussed in the field of chemical microsensors that attempt to marry physical transducers based on microelectronic and optoelectronic technologies with thin films and coatings that serve as chemical transducers. Microelectronic silicon chemical sensors, acoustic wave sensors, microsensors based on optical fibers, and electrochemical microsensors are considered. Both technological achievements and problems that remain to be solved are addressed.

Hughes, R. C.; Ricco, A. J.; Butler, M. A.; Martin, S. J.

1991-10-01

283

Serum fluoride and sialic acid levels in osteosarcoma.  

PubMed

Osteosarcoma is a rare malignant bone tumor most commonly occurring in children and young adults presenting with painful swelling. Various etiological factors for osteosarcoma are ionizing radiation, family history of bone disorders and cancer, chemicals (fluoride, beryllium, and vinyl chloride), and viruses. Status of fluoride levels in serum of osteosarcoma is still not clear. Recent reports have indicated that there is a link between fluoride exposure and osteosarcoma. Glycoproteins and glycosaminoglycans are an integral part of bone and prolonged exposure to fluoride for long duration has been shown to cause degradation of collagen and ground substance in bones. The present study was planned to analyze serum fluoride, sialic acid, calcium, phosphorus, and alkaline phosphatase levels in 25 patients of osteosarcoma and age- and sex-matched subjects with bone-forming tumours other than osteosarcoma and musculo-skeletal pain (controls, 25 each). Fluoride levels were analyzed by ISE and sialic acid was analyzed by Warren's method. Mean serum fluoride concentration was found to be significantly higher in patients with osteosarcoma as compared to the other two groups. The mean value of flouride in patients with other bone-forming tumors was approximately 50% of the group of osteosarcoma; however, it was significantly higher when compared with patients of group I. Serum sialic acid concentration was found to be significantly raised in patients with osteosarcoma as well as in the group with other bone-forming tumors as compared to the group of controls. There was, however, no significant difference in the group of patients of osteosarcoma when compared with group of patients with other bone-forming tumors. These results showing higher level of fluoride with osteosarcoma compared to others suggesting a role of fluoride in the disease. PMID:19390788

Sandhu, R; Lal, H; Kundu, Z S; Kharb, S

2011-12-01

284

Serum immunoglobulins in women with breast cancer.  

PubMed

Serum immunoglobulins were determined in 120 women with breast cancer. A strong association between age at tumor diagnosis and serum IgA levels was noted. Relative hypoglobulinemia of IgA was associated with appearance of tumors early in life, and was more frequent among women with family history of breast cancer and among those with poor prognosis. A strong association between levels of serum IgG and parity was noted. Parous women and/or those who had good prognosis had higher levels of serum IgG, compared to nulliparous women and those with poor prognosis. The observations indicate that serum immunoglobulins may be useful in the identification of women who have a high breast cancer risk and poor prognosis. PMID:491683

Papatestas, A E; Bramis, J; Aufses, A H

1979-01-01

285

Serum Ferritin: Past, Present and Future  

PubMed Central

Background Serum ferritin was discovered in the 1930’s, and was developed as a clinical test in the 1970’s. Many diseases are associated with iron overload or iron deficiency. Serum ferritin is widely used in diagnosing and monitoring these diseases. Scope of Review In this chapter, we discuss the role of serum ferritin in physiological and pathological processes and its use as a clinical tool. Major Conclusions Although many aspects of the fundamental biology of serum ferritin remain surprisingly unclear, a growing number of roles have been attributed to extracellular ferritin, including newly described roles in iron delivery, angiogenesis, inflammation, immunity, signaling and cancer. General Significance Serum ferritin remains a clinically useful tool. Further studies on the biology of this protein may provide new biological insights. PMID:20304033

Wang, Wei; Knovich, Mary Ann; Coffman, Lan G.; Torti, Frank M.; Torti, Suzy V.

2010-01-01

286

Serum leptin in renal transplant patients  

PubMed Central

Leptin is a small peptide hormone that is mainly produced in adipose tissues. Leptin plays animportant role in regulating appetite and energy expenditure and may be involved in modulatingbone mineralization. This study was designed to test the association of serum leptin kidneyfunction in renal transplant recipients. We studied 72 kidney transplanted recipients. In thisstudy a significant difference of serum leptin between males and females with higher values infemales was seen (p>0.05). There was not relationship between serum leptin with body massindex, age and creatinine clearance (p>0.05). A negative relationship between serum leptin andthe duration of kidney transplantation was found (r= -0.26, p= 0.03). The clinical significanceof inverse association between serum leptin and the duration of renal transplantation, shouldconsider more in larger studies. PMID:25340128

Rafieian-Kopaei, Mahmoud; Nasri, Hamid

2013-01-01

287

Measuring Serum Melatonin in Epidemiologic Studies  

PubMed Central

Background Epidemiologic data on serum melatonin, a marker of circadian rhythms, and cancer are sparse due largely to the lack of reliable assays with high sensitivity to detect relatively low melatonin levels in serum collected during daylight, as commonly available in most epidemiologic studies. Methods To help expand epidemiologic research on melatonin, we assessed the reproducibility and refined a currently available melatonin radioimmunoassay, and evaluated its application to epidemiologic investigations by characterizing melatonin levels in serum, urine, and/or plasma in 135 men from several ethnic groups. Results Reproducibility was high for the standard 1.0 ml serum- (mean coefficient of variation (CV)=6.9%, intraclass correlation coefficient (ICC)=97.4%, n=2 serum pools in triplicate) and urine-based (mean CV=3.5%, ICC=99.9%) assays. Reproducibility for the 0.5 ml refined-serum assay was equally good (mean CV=6.6%%;ICC=99.0%). There was a positive correlation between morning serum melatonin and 6-sulfatoxymelatonin in 24-hour urine(r=0.46, P=0.008; n=49 subjects). Melatonin levels in serum-plasma pairs had a high correlation (r=0.97, P<1 × 10?4; n=20) Morning serum melatonin levels were five times higher than those from the afternoon (before 9 AM mean = 11.0 pg/mL versus after 11 AM mean=2.0 pg/mL). Chinese men had lower melatonin levels (mean=3.4 pg/mL), while Caucasian, African American, and Ghanaian men had similar levels (mean=6.7–8.6 pg/mL). Conclusions These results suggest that melatonin can be detected reliably in serum samples collected in epidemiologic studies in various racial groups. Impact With improved assays, it may be possible to investigate the role of melatonin and the emerging circadian rhythm hypothesis in cancer etiology in epidemiologic studies. PMID:20332275

Hsing, Ann W.; Meyer, Tamra E.; Niwa, Shelley; Quraishi, Sabah M.; Chu, Lisa W.

2010-01-01

288

Reactions of trimethylphosphine analogues of auranofin with bovine serum albumin  

SciTech Connect

The reactions of bovine serum albumin (BSA) with (trimethylphosphine)(2,3,4,6-tetra-O-acetyl-1-thio-..beta..-D-glucopyranosato-S)gold(I), Me/sub 3/PAuSAtg, and its chloro analogue, Me/sub 3/PAuCl, were studied to develop insights into the role of the phosphine ligand in the serum chemistry of the related antiarthritic drug auranofin (triethylphosphine)(2,3,4,6-tetra-O-acetyl-1-thio-..beta..-D-glucopyranosato-S)gold(I). /sup 31/P NMR spectroscopy, protein modification, and gel-exclusion chromatography methods were employed. Comparison of the reactions of the methyl derivatives to the previously reported reactions of auranofin and Et/sub 3/PAuCl with BSA demonstrated that similar chemical species are formed but revealed three major differences. Despite these differences, the results for the methyl analogues provide important confirmation for previously developed chemical models of auranofin reactions in serum. Me/sub 3/PO was not observed in reaction mixtures lacking tetraacetylthioglucose (AtgSH); this result affirms the role of AtgSH, displaced by the reaction of Me/sub 3/PAuSAtg at Cys-34, in the generation of the phosphine oxide (an important metabolite in vivo). The weak binding sites on albumin react with Me/sub 3/PAuCl, but not Me/sub 3/PAuSAtg, demonstrating the importance of the strength and reactivity of the anionic ligand-gold bond on the reactions of auranofin analogues. The gold binding capacity of albumin is enhanced after Me/sub 3/PO is formed, consistent with reductive cleavage of albumin disulfide bonds by trimethylphosphine. 24 references, 2 figures, 3 tables.

Isab, A.A.; Shaw, C.F. III; Hoeschele, J.D.; Locke, J.

1988-10-05

289

Simple Chemiluminescence Assays for Free Radicals in Venous Blood and Serum Samples: Results in Atopic, Psoriasis, MCS and Cancer Patients  

Microsoft Academic Search

Summary Objective: To investigate the generation of reactive oxygen species (ROS) in serum and venous blood as well as the serum antioxidative activity (AOA) in patients and healthy controls by means of a simplified chemiluminescence (CL) methodology. Study Participants:48 Atopic eczema, 23 psoriasis, 15 multiple chemical sensitivity (MCS) and 35 cancer patients together with 22 healthy volunteers. Methods:ROS generation\\/photon emission

G. Ionescu; M. Merk; R. Bradford

1999-01-01

290

Serum and Urinary NGAL in Septic Newborns  

PubMed Central

Neutrophil gelatinase-associated lipocalin (NGAL) is postulated to be a potentially new and highly specific/sensitive marker of acute kidney injury (AKI). The aim of this study was to assess the impact of inflammation on serum and urine NGAL in newborns that were treated due to infection. We determined serum and urine NGAL concentrations in 73 infants (51 with sepsis; 22 with severe sepsis) admitted to the Intensive Care Unit in the first month of life, for three consecutive days during the course of treatment for infection. 29 neonates without infection served as the control group. Septic patients, in particular, severe sepsis patients, had increased serum and urinary NGAL levels in the three subsequent days of observation. Five septic patients who developed AKI had elevated serum and urinary NGAL values to a similar extent as septic neonates without AKI. A strong correlation was found between the concentration of serum and urinary NGAL and inflammatory markers, such as CRP and procalcitonin. Serum and urinary NGAL levels were also significantly associated with NTISS (neonatal therapeutic intervention scoring system) values. We conclude that increased serum and urinary NGAL values are not solely a marker of AKI, and more accurately reflect the severity of inflammatory status. PMID:24579085

Suchojad, Anna; Majcherczyk, Malgorzata; Jadamus-Niebroj, Danuta; Owsianka-Podlesny, Teresa; Brzozowska, Aniceta

2014-01-01

291

EFFECTS OF SERUM ON MEMBRANE TRANSPORT  

PubMed Central

The effects of normal rabbit serum (NRS) on two transport systems in rabbit lung macrophages have been examined. A 20 min preincubation with serum was required for the effects, which were retained for at least 40 min after serum was removed. No serum was present during the transport studies. (a) Preincubation with 0.5 or 1.0% NRS resulted in depression of lysine transport to 59 ± 2.6% (SE, 31 observations) of control levels. The activity was heat stable to 100°C for 30 min and lost after dialysis. Pretreatment with serum did not alter the intracellular concentration of lysine attained when cells were then incubated with 10 mM lysine for 30 min. The relative depression of lysine transport by serum was unaltered by preloading with such high concentrations of lysine. (b) Preincubation with 5% NRS resulted in enhancement of adenosine transport by 35 ± 2.3% (SE, 60 observations). Activity was stable to heating at 65°C for 40 min but lost at 100°C for 20 min. It was nondialyzable. Total radioactivity accumulated after 30 min incubation with 1 mM adenosine was unaffected by serum pretreatment. The two activities were separable by passage over Sephadex G25. PMID:4119589

Strauss, Phyllis R.; Berlin, Richard D.

1973-01-01

292

Soluble kit receptor in human serum.  

PubMed

c-kit encodes the transmembrane receptor tyrosine kinase (Kit) for the recently described ligand stem cell factor (SCF). We have developed an enzyme-linked immunosorbent assay for measuring soluble human Kit and we have used the assay to show high levels of soluble Kit in human serum. The distribution of soluble Kit levels was investigated among 112 normal human serum donors. The mean serum level (+/- SD) was found to be 324 +/- 105 ng/mL with the values falling between 163 ng/mL and 788 ng/mL. No correlation between soluble Kit levels and the sexes or ages of the donors was found. Partial purification using immunoaffinity chromatography allowed us to characterize the soluble Kit from pooled human serum. Antibodies generated to a 497-amino acid recombinant human soluble Kit corresponding to the N-terminal extracellular domain of the receptor recognized the serum-derived soluble Kit by immunoblotting. We found that the serum-derived soluble Kit is glycosylated, with mostly N-linked but also O-linked carbohydrate, and with terminal sialic acid residues. When compared with the recombinant human soluble Kit, the serum-derived material was similar both in size and glycosylation pattern. CNBr cleavage of the isolated serum-derived material followed by amino terminal sequencing confirmed the presence of five peptides expected for the extracellular portion of the Kit molecule. The immunoaffinity purified serum-derived soluble Kit inhibited binding of [125I]SCF to membrane-bound receptor in an in vitro assay. These results indicate that soluble Kit could modulate the activity and functions of SCF in vivo. PMID:7528574

Wypych, J; Bennett, L G; Schwartz, M G; Clogston, C L; Lu, H S; Broudy, V C; Bartley, T D; Parker, V P; Langley, K E

1995-01-01

293

[Chemical weapons and chemical terrorism].  

PubMed

Chemical Weapons are kind of Weapons of Mass Destruction (WMD). They were used large quantities in WWI. Historically, large quantities usage like WWI was not recorded, but small usage has appeared now and then. Chemical weapons are so called "Nuclear weapon for poor countrys" because it's very easy to produce/possession being possible. They are categorized (1) Nerve Agents, (2) Blister Agents, (3) Cyanide (blood) Agents, (4) Pulmonary Agents, (5) Incapacitating Agents (6) Tear Agents from the viewpoint of human body interaction. In 1997 the Chemical Weapons Convention has taken effect. It prohibits chemical weapons development/production, and Organization for the Prohibition of Chemical Weapons (OPCW) verification regime contributes to the chemical weapons disposal. But possibility of possession/use of weapons of mass destruction by terrorist group represented in one by Matsumoto and Tokyo Subway Sarin Attack, So new chemical terrorism countermeasures are necessary. PMID:16296384

Nakamura, Katsumi

2005-10-01

294

Serum Protein Pattern in African Neonates  

PubMed Central

Serum protein concentrations were determined in the cord blood of 75 African and 10 European babies born in Zambia, and in the venous blood of 5 pregnant African women at term. When the high ?-globulin fraction was excluded, there was no significant difference between the pattern of serum proteins of the Africans and the Europeans at birth. Present evidence favours the view that the high serum ?-globulin and low albumin of the adult Negro have an environmental rather than a genetic background. PMID:4103832

Ezeilo, Gabriel C.

1971-01-01

295

Effects of Transport Stress on Serum Alkaline Phosphatase Activity in Beagle Dogs  

PubMed Central

Here, to determine the effects of transport stress on blood parameters in dogs, we investigated the changes in hematologic and serum chemical parameters in healthy beagle dogs transported from Beijing, China, to Osaka, Japan, to obtain the background data. Only the activity of serum alkaline phosphatase increased clearly upon arrival, a change attributed to transport stress, but the activity gradually reduced afterward. No marked changes in levels of other blood parameters were noted. Our findings here suggest that alkaline phosphatase is a useful tool for studying transport stress. PMID:24172197

Ochi, Takehiro; Nishiura, Ippei; Tatsumi, Mitsuyoshi; Hirano, Yoshimi; Yahagi, Kouichi; Sakurai, Yasuhiro; Sudo, Yuji; Koyama, Hironari; Hagita, Yuichi; Fujimoto, Yoshikatsu; Kitamura, Shinji; Hashimoto, Hideki; Nakamura, Tomoya; Yamada, Asobi; Tanimoto, Masayoshi; Nishina, Noriko

2013-01-01

296

Determination of cefatrizine in serum and urine by reversed-phase high-performance liquid chromatography.  

PubMed

A fast and simple high-performance liquid chromatographic procedure for the determination of cefatrizine, an orally active cephalosporin, in serum and urine is proposed. Reversed-phase liquid chromatography on the octoadecylsilane chemically bonded microparticulate packing, using methanol in 0.03 M sodium phosphate buffer (pH 5) as eluent, was used to separate and quantitate the antibiotic. The samples were analysed after deproteinization with trichloroacetic acid and injection of the clear supernatant. The accuracy and reproducibility of the procedure were investigated by determination of the cefatrizine content in spiked serum and urine samples, using cephradine as the internal standard. PMID:546870

Crombez, E; Van der Weken, G; Van den Bossche, W; De Moerloose, P

1979-05-11

297

Serum PBDEs in a North Carolina Toddler Cohort: Associations with Handwipes, House Dust, and Socioeconomic Variables  

PubMed Central

Background: Polybrominated diphenyl ethers (PBDEs) are persistent, bioaccumulative, and endocrine-disrupting chemicals. Objectives: We used handwipes to estimate exposure to PBDEs in house dust among toddlers and examined sex, age, breast-feeding, race, and parents’ education as predictors of serum PBDEs. Methods: Eighty-three children from 12 to 36 months of age were enrolled in North Carolina between May 2009 and November 2010. Blood, handwipe, and house dust samples were collected and analyzed for PBDEs. A questionnaire was administered to collect demographic data. Results: PBDEs were detected in all serum samples (geometric mean for ?pentaBDE in serum was 43.3 ng/g lipid), 98% of the handwipe samples, and 100% of the dust samples. Serum ?pentaBDEs were significantly correlated with both handwipe and house dust ?pentaBDE levels, but were more strongly associated with handwipe levels (r = 0.57; p < 0.001 vs. r = 0.35; p < 0.01). Multivariate model estimates revealed that handwipe levels, child’s sex, child’s age, and father’s education accounted for 39% of the variation in serum ?BDE3 levels (sum of BDEs 47, 99, and 100). In contrast, age, handwipe levels, and breast-feeding duration explained 39% of the variation in serum BDE 153. Conclusions: Our study suggests that hand-to-mouth activity may be a significant source of exposure to PBDEs. Furthermore, age, socioeconomic status, and breast-feeding were significant predictors of exposure, but associations varied by congener. Specifically, serum ?BDE3 was inversely associated with socioeconomic status, whereas serum BDE-153 was positively associated with duration of breast-feeding and mother’s education. PMID:22763040

Eagle, Sarah; Sjödin, Andreas; Webster, Thomas F.

2012-01-01

298

Cathepsin-L Can Resist Lysis by Human Serum in Trypanosoma brucei brucei  

PubMed Central

Closely related African trypanosomes cause lethal diseases but display distinct host ranges. Specifically, Trypanosoma brucei brucei causes nagana in livestock but fails to infect humans, while Trypanosoma brucei gambiense and Trypanosoma brucei rhodesiense cause sleeping sickness in humans. T. b. brucei fails to infect humans because it is sensitive to innate immune complexes found in normal human serum known as trypanolytic factor (TLF) 1 and 2; the lytic component is apolipoprotein-L1 in both TLFs. TLF resistance mechanisms of T. b. gambiense and T. b. rhodesiense are now known to arise through either gain or loss-of-function, but our understanding of factors that render T. b. brucei susceptible to lysis by human serum remains incomplete. We conducted a genome-scale RNA interference (RNAi) library screen for reduced sensitivity to human serum. Among only four high-confidence ‘hits’ were all three genes previously shown to sensitize T. b. brucei to human serum, the haptoglobin-haemoglobin receptor (HpHbR), inhibitor of cysteine peptidase (ICP) and the lysosomal protein, p67, thereby demonstrating the pivotal roles these factors play. The fourth gene identified encodes a predicted protein with eleven trans-membrane domains. Using chemical and genetic approaches, we show that ICP sensitizes T. b. brucei to human serum by modulating the essential cathepsin, CATL, a lysosomal cysteine peptidase. A second cathepsin, CATB, likely to be dispensable for growth in in vitro culture, has little or no impact on human-serum sensitivity. Our findings reveal major and novel determinants of human-serum sensitivity in T. b. brucei. They also shed light on the lysosomal protein-protein interactions that render T. b. brucei exquisitely sensitive to lytic factors in human serum, and indicate that CATL, an important potential drug target, has the capacity to resist these factors. PMID:24830321

Alsford, Sam; Currier, Rachel B.; Guerra-Assuncao, Jose Afonso; Clark, Taane G.; Horn, David

2014-01-01

299

[New approaches to early diagnosis of chronic organophosphorus chemicals intoxication in workers at chemical weapons extermination objects].  

PubMed

Mass spectrum analysis revealed differences in general contents of low-molecular peptides spectrums in chemical weapons extermination object staffers, in comparison with the reference group. Findings are that serum paraoxonase activity in chemical weapons extermination object staffers in significantly increased. PMID:19514167

Babakov, V N; Goncharov, N V; Radilov, A S; Glashkina, E P; Podol'skaia, E P; Ermolaeva, E E; Shilov, V V; Prokof'eva, D S; Vo?tenko, N G; Egorov, N A

2009-01-01

300

[Determination of serum vancomycin using capillary isotachophoresis].  

PubMed

The paper aims to study the possibilities of determining vancomycin in the serum by the method of capillary isotachophoresis. The leading electrolyte contained Na+ as the leading ion, morpholinoethanesulphonic acid as the counter-ion (pH 6,2), and methylhydroxyethyl cellulose as the additive. The terminating electrolyte was morpholinoethanesulphonic acid. The conductivity detector was employed for detection. Ethanol was selected for precipitation of proteins. The yield of vancomycin from the serum was 89-91%. The calibration curve is linear in an interval of 0.02-0.5 microgram (the absolutely dosed amount). The limit of vancomycin determination in the serum is 4 micrograms/ml. The method was employed to determine vancomycin in the serum of patients. The obtained results correlated well with those obtained by fluorescent polarizing immunoanalysis (TDx) in a concentration interval of 4-30 micrograms/ml. PMID:8599730

Sádecká, J; Polonský, J; Netriová, J

1995-12-01

301

Precipitin reaction between serum and lysed erythrocytes  

PubMed Central

The albumin fraction of all normal sera contains a factor which precipitates with part of the normal haemoglobin molecule, the reaction occurring in the proportions of 1 ml. serum to 6 to 15 mg. haemoglobin. Images PMID:14007373

Wilson, J. F.; Warren, Gillian

1962-01-01

302

Degradation of azlocillin in human serum.  

PubMed

We developed a rapid and precise high performance liquid chromatographic method (HPLC) for the determination of azlocillin and its metabolites penicilloate and penilloate in serum and tissue as well as in vivo as in vitro. The linear relationship (r greater than 0.99) of determination ranged between 0.05 and 10 micrograms. No interference with other serum components was observed. The metabolism of azlocillin in vitro was analysed in serum. Within 24 h the amount of penicilloate increased from 1.5% up to 18% and from penilloate up to 1% respectively. Buffer controls revealed a significant lower metabolism (4.7% penicilloate, 0.9% penilloate). These data suggest that the degradation of azlocillin does not only depend on bacterial beta-lactamase activity but is influenced by enzymatic activities within serum and human tissue. PMID:3002076

Schönfeld, W; Knöller, J; Bremm, K D; König, W

1985-10-01

303

Direct immunoassay of triiodothyronine in human serum  

PubMed Central

A sensitive and precise radioimmunoassay for the direct measurement of triiodothyronine (T3) in human serum has been designed using sodium salicylate to block T3-TBG binding. This assay is sufficiently sensitive to quantitate T3 accurately in 50-100 ?l of normal serum and to measure quantities as small as 12.5 pg in 0.2 ml of hypothyroid serum. The T3 values observed in euthyroid subjects and in patients with various thyroid diseases are as follows: euthyroid (38) 1.10±0.25 (SD) ng/ml, hypothyroid (25) 0.39±0.21 (SD) ng/ml, and hyperthyroid (24) 5.46±4.42 (SD) ng/ml. The levels of T3 parallel the thyroxine (T4) concentration in the sera of these subjects. In eight pregnant women at the time of delivery, T3 concentrations were in the upper normal range (mean 1.33 ng/ml). The levels of T3 in cord serum obtained at the time of delivery of these patients (mean 0.53 ng/ml) are distinctly lower and close to the hypothyroid mean. Administration of 10 U of bovine thyroid-stimulating hormone (TSH) to euthyroid subjects causes a two-fold increase in serum T3 levels within 8 hr. At this time, the increase in serum T4 concentration is only 41%. In two subjects in whom thyroid secretion was acutely inhibited, one after pituitary surgery and another after thyroidectomy, the serum T3 fell into the hypothyroid range within 1-2 days. Thus, serum T3 concentrations appear to be a sensitive index of acute changes in thyroid hormone secretion and should prove to be a useful adjunct to both the clinical and physiological evaluation of thyroid function. PMID:4626581

Larsen, P. R.

1972-01-01

304

Photothermal Measurements on Human Serum and Plasma  

NASA Astrophysics Data System (ADS)

Using a thermal lens experimental set up, the thermal diffusivity of serum and plasma was measured. Several samples were studied and the results are reported as the average with the standard deviation. The serum and plasma were obtained by aleatory sampling of healthy adult donors at the Guanajuato State Transfusion Center, Mexico; the donors were free of hepatitis and other diseases, clinically tested. The parameters reported were obtained using the thermal lens aberrant model with the lasers operating in the mismatched mode.

Bernal-Alvarado, J.; Sosa, M.; Hernández, L. C.; Hernández-Cabrera, F.; Mayén-Mondragón, R.; Yánez-Limón, J. M.; Flores-Farías, R.; Palomares, P.; Juárez, P.; Ramírez, R.

2003-09-01

305

Chemical Reactions  

NSDL National Science Digital Library

We don't often stop to think about it, but underlying many of our everyday activities are chemical reactions. From the cooking of an egg to the growth of a child, chemical reactions make things happen. Although many of the reactions that support our lives

National Science Teachers Association (NSTA)

2009-05-01

306

Chemical sensors  

DOEpatents

Sensors responsive to small changes in the concentration of chemical species are disclosed, comprising (a) a mechanochemically responsive polymeric film capable of expansion or contraction in response to a change in its chemical environment, operatively coupled to (b) a transducer capable of directly converting said expansion or contraction to a measurable electrical response.

Lowell, Jr., James R. (Bend, OR); Edlund, David J. (Bend, OR); Friesen, Dwayne T. (Bend, OR); Rayfield, George W. (Bend, OR)

1991-01-01

307

Chemical sensors  

DOEpatents

Sensors responsive to small changes in the concentration of chemical species are disclosed. The sensors comprise a mechanochemically responsive polymeric film capable of expansion or contraction in response to a change in its chemical environment. They are operatively coupled to a transducer capable of directly converting the expansion or contraction to a measurable electrical response. 9 figures.

Lowell, J.R. Jr.; Edlund, D.J.; Friesen, D.T.; Rayfield, G.W.

1991-07-02

308

Factors influencing serum aluminum in CAPD patients.  

PubMed

The aim of this study was to find out the relationship between body iron stores and serum aluminum levels among 82 stable CAPD patients. The influence of other factors such as time on CAPD and residual renal function was also considered. Thirty-three patients received aluminum hydroxide as a phosphate binder, and they had significantly higher aluminum levels (36.45 microg/l) than the patients who were not taking aluminum preparations (17.2 microg/l, p = 0.001). A statistically-significant correlation between serum aluminum levels and residual renal function and time on CAPD was also observed (p <0.05). However, there was no relationship between serum aluminum levels and serum iron, ferritin and transferrin saturation, neither between body iron stores and total excretion of aluminum (p >0.05). In previous reports, low serum iron levels were associated with high serum aluminum concentration among hemodialysis patients. However, this effect was not observed in the CAPD population under study. The highest risk of hyperaluminemia was found in the patients who were taking aluminum hydroxide, had worse residual renal function and had been longer on CAPD. PMID:9725777

Montenegro, J; Aguirre, R; Saracho, R; Moina, I; Martínez, I

1998-08-01

309

Fractionation of serum components using nanoporous substrates.  

PubMed

Numerous previously uncharacterized molecules resident within the low molecular weight circulatory proteome may provide a picture of the ongoing pathophysiology of an organism. Recently, proteomic signatures composed of low molecular weight molecules have been identified using mass spectrometry combined with bioinformatic algorithms. Attempts to sequence and identify the molecules that underpin the fingerprints are currently underway. The finding that many of these low molecular weight molecules may exist bound to circulating carrier proteins affords a new opportunity for fractionation and separation techniques prior to mass spectrometry-based analysis. In this study we demonstrate a method whereby nanoporous substrates may be used for the facile and reproducible fractionation and selective binding of the serum-based biomarker material, including subcellular proteins found within the serum. Aminopropyl-coated nanoporous silicon, when exposed to serum, can deplete serum of proteins and yield a serum with a distinct, altered MS profile. Additionally, aminopropyl-coated, nanoporous controlled-pore glass beads are able to bind a subset of serum proteins and release them with stringent elution. The eluted proteins have distinct MS profiles, gel electrophoresis profiles, and differential peptide sequence identities, which vary based on the size of the nanopores. These material surfaces could be employed in strategies for the harvesting and preservation of labile and carrier-protein-bound molecules in the blood. PMID:16704202

Geho, David; Cheng, Mark Ming-Cheng; Killian, Keith; Lowenthal, Mark; Ross, Sally; Frogale, Kristina; Nijdam, Jasper; Lahar, Nicholas; Johann, Don; Herrmann, Paul; Whiteley, Gordon; Ferrari, Mauro; Petricoin, Emanuel; Liotta, Lance

2006-01-01

310

Clinical utility of serum sclerostin measurements.  

PubMed

Sclerostin is an osteocyte-secreted soluble antagonist of the Wnt/?-catenin signaling pathway requisite for osteoblast development and activity. Efforts over the past several years have focused on unraveling the role of sclerostin in both normal physiological and pathological conditions. Sclerostin levels are undetectable in the serum of patients with sclerosteosis. In normal individuals, serum sclerostin levels are higher in males and increase in both sexes across the adult lifespan. Some, but not other, studies have demonstrated that higher serum sclerostin levels are associated with increased fracture risk, particularly when paired with lower bone mineral density. Levels of circulating sclerostin are highly correlated with bone marrow sclerostin levels. Sclerostin levels are inversely related to parathyroid hormone levels. Clinical conditions in which serum sclerostin levels have been measured include ankylosing spondylitis, chronic kidney disease, diabetes, fractures, hypercortisolism, multiple myeloma and spinal cord injury. Even within clearly defined clinical conditions, however, consistent changes in serum sclerostin levels have not always been seen. This may reflect differences in currently available commercial assays or sample sources (serum versus plasma), and suggests further study is needed before sclerostin measurements are introduced into routine clinical practice. Until such issues are resolved, measurement of sclerostin levels appears to be most useful for understanding the mechanisms by which osteocytes regulate bone turnover through the integration of hormonal, physical and pharmacological stimuli, rather than to guide clinical-care decisions. PMID:24578825

Clarke, Bart L; Drake, Matthew T

2013-01-01

311

Clinical utility of serum sclerostin measurements  

PubMed Central

Sclerostin is an osteocyte-secreted soluble antagonist of the Wnt/?-catenin signaling pathway requisite for osteoblast development and activity. Efforts over the past several years have focused on unraveling the role of sclerostin in both normal physiological and pathological conditions. Sclerostin levels are undetectable in the serum of patients with sclerosteosis. In normal individuals, serum sclerostin levels are higher in males and increase in both sexes across the adult lifespan. Some, but not other, studies have demonstrated that higher serum sclerostin levels are associated with increased fracture risk, particularly when paired with lower bone mineral density. Levels of circulating sclerostin are highly correlated with bone marrow sclerostin levels. Sclerostin levels are inversely related to parathyroid hormone levels. Clinical conditions in which serum sclerostin levels have been measured include ankylosing spondylitis, chronic kidney disease, diabetes, fractures, hypercortisolism, multiple myeloma and spinal cord injury. Even within clearly defined clinical conditions, however, consistent changes in serum sclerostin levels have not always been seen. This may reflect differences in currently available commercial assays or sample sources (serum versus plasma), and suggests further study is needed before sclerostin measurements are introduced into routine clinical practice. Until such issues are resolved, measurement of sclerostin levels appears to be most useful for understanding the mechanisms by which osteocytes regulate bone turnover through the integration of hormonal, physical and pharmacological stimuli, rather than to guide clinical-care decisions. PMID:24578825

Clarke, Bart L; Drake, Matthew T

2013-01-01

312

Chemical peels.  

PubMed

Chemical peels are a method of resurfacing with a long-standing history of safety in the treatment of various skin conditions. This article reviews the classification of different chemical agents based on their depth of injury. The level of injury facilitates cell turnover, epidermal thickening, skin lightening, and new collagen formation. Preprocedural, periprocedural, and postprocedural skin care are briefly discussed. To select the appropriate chemical peel, the provider should evaluate the patient's expectations, medical history, skin type, and possible complications to determine the best chemical peel to achieve the desired results. Patients with Fitzpatrick skin types IV to VI have increased risk of dyspigmentation, hypertrophic, and keloid scarring. These individuals respond well to superficial and medium-depth chemical peels. Advances in the use of combination peels allow greater options for skin rejuvenation with less risk of complications. PMID:24488634

Jackson, Adrianna

2014-02-01

313

Chemical threats.  

PubMed

The use of chemical agents as military weapons has been recognized for many centuries but reached the most feared and publicized level during World War I. Considerable political effort has been exercised in the twentieth century to restrict military strategies with chemicals. However, considerable concern currently exists that chemical weapons may be used as agents in civilian terrorism. The distribution of acetaminophen tablets contaminated with potassium cyanide and the release of sarin in the Tokyo sub-way system show that larger-scale deployment of chemical agents can be a reality. This reality makes it necessary for civilian disaster-planning strategies to incorporate an understanding of chemical agents, their effects, and the necessary treatment. PMID:16781273

Fry, Donald E

2006-06-01

314

Exploring Indirect Sources of Human Exposure to Perfluoroalkyl Carboxylates (PFCAs): Evaluating Uptake, Elimination, and Biotransformation of Polyfluoroalkyl Phosphate Esters (PAPs) in the Rat  

PubMed Central

Background Perfluorinated carboxylic acids (PFCAs) are ubiquitous in human sera worldwide. Biotransformation of the polyfluoroalkyl phosphate esters (PAPs) is a possible source of PFCA exposure, because PAPs are used in food-contact paper packaging and have been observed in human sera. Objectives We determined pharmacokinetic parameters for the PAP monoesters (monoPAPs) and PAP diesters (diPAPs), as well as biotransformation yields to the PFCAs, using a rat model. Methods The animals were dosed intravenously or by oral gavage with a mixture of 4:2, 6:2, 8:2, and 10:2 monoPAP or diPAP chain lengths. Concentrations of the PAPs and PFCAs, as well as metabolic intermediates and phase II metabolites, were monitored over time in blood, urine, and feces. Results The diPAPs were bioavailable, with bioavailability decreasing as the chain length increased from 4 to 10 perfluorinated carbons. The monoPAPs were not absorbed from the gut; however, we found evidence to suggest phosphate-ester cleavage within the gut contents. We observed biotransformation to the PFCAs for both monoPAP and diPAP congeners. Conclusions Using experimentally derived biotransformation yields, perfluorooctanoic acid (PFOA) sera concentrations were predicted from the biotransformation of 8:2 diPAP at concentrations observed in human serum. Because of the long human serum half-life of PFOA, biotransformation of diPAP even with low-level exposure could over time result in significant exposure to PFOA. Although humans are exposed directly to PFCAs in food and dust, the pharmacokinetic parameters determined here suggest that PAP exposure should be considered a significant indirect source of human PFCA contamination. PMID:21059488

D’eon, Jessica C.; Mabury, Scott A.

2011-01-01

315

Proportion of nervonic acid in serum lipids is associated with serum plasmalogen levels and metabolic syndrome.  

PubMed

An increase in serum plasmalogens (1-O-alk-1-enyl-2-acyl glycerophospholipids), which are endogenous anti-oxidative phospholipids, can potentially prevent age-related diseases such as atherosclerosis and metabolic syndrome (MetS). Very long chain fatty acids (VLCFAs) in plasma may supply the materials for plasmalogen biosynthesis through peroxisomal beta-oxidation. On the other hand, elevated levels of saturated and monounsaturated VLCFAs in plasma appear to be associated with decreased peroxisomal function, and are a symptom of age-related diseases. To reconcile these contradictory findings, we attempted to investigate the relationship between the serum levels of saturated and monounsaturated VLCFAs, clinical and biochemical parameters, and serum levels of plasmalogens in subjects with MetS (n = 117), who were asymptomatic Japanese males over 40 years of age. Fatty acids in serum lipids were quantified using gas chromatography/mass spectrometry (GC/MS). Serum plasmalogen levels were determined by liquid chromatography using radioactive iodine (¹²?I-HPLC), and the molecular composition of serum plasmalogens was analyzed by liquid chromatography-tandem mass spectrometry (LC/MS/MS). We found that MetS subjects showed a significant reduction in the proportion of specific saturated and monounsaturated VLCFAs such as behenic acid (C22:0), lignoceric acid (C24:0), and nervonic acid (C24:1) in serum lipids compared to non-MetS subjects. These VLCFAs were positively associated with serum levels of high density lipoprotein cholesterol (HDL-C) as well as plasmalogen-related parameters, and inversely with serum levels of triglyceride (TG) and small dense low density lipoprotein cholesterol (sdLDL-C). In conclusion, the proportion of nervonic acid in serum lipids is associated with serum levels of plasmalogens and with MetS, and probably reflects the peroxisomal dysfunction and enhancement of endoplasmic reticulum (ER) stress seen in common age-related diseases. PMID:24770479

Yamazaki, Yuya; Kondo, Kazuya; Maeba, Ryouta; Nishimukai, Megumi; Nezu, Toru; Hara, Hiroshi

2014-01-01

316

Serum fructosamine in canine diabetes mellitus. An initial study  

Microsoft Academic Search

This study reports on a spectrophotometric assay for the determination of serum fructosamine concentration. The assay was evaluated for use in canine serum samples by assessment of the precision, accuracy, detectability and stability of serum fructosamine during storage. To evaluate the diagnostic usefulness of the assay, both the effect of acute changes in blood glucose on serum fructosamine concentration and

A. L. Jensen

1992-01-01

317

Inferring serum proteolytic activity from LC-MS/MS data  

PubMed Central

Background In this paper we deal with modeling serum proteolysis process from tandem mass spectrometry data. The parameters of peptide degradation process inferred from LC-MS/MS data correspond directly to the activity of specific enzymes present in the serum samples of patients and healthy donors. Our approach integrate the existing knowledge about peptidases' activity stored in MEROPS database with the efficient procedure for estimation the model parameters. Results Taking into account the inherent stochasticity of the process, the proteolytic activity is modeled with the use of Chemical Master Equation (CME). Assuming the stationarity of the Markov process we calculate the expected values of digested peptides in the model. The parameters are fitted to minimize the discrepancy between those expected values and the peptide activities observed in the MS data. Constrained optimization problem is solved by Levenberg-Marquadt algorithm. Conclusions Our results demonstrates the feasibility and potential of high-level analysis for LC-MS proteomic data. The estimated enzyme activities give insights into the molecular pathology of colorectal cancer. Moreover the developed framework is general and can be applied to study proteolytic activity in different systems. PMID:22537011

2012-01-01

318

Unnecessary Chemicals  

ERIC Educational Resources Information Center

Discusses the health hazards resulting from chemical additions of many common products such as cough syrups, food dyes, and cosmetics. Steps being taken to protect consumers from these health hazards are included. (MDR)

Johnson, Anita

1978-01-01

319

Chemical Analyses.  

National Technical Information Service (NTIS)

As a preliminary study on the effects of chemical aging of polymer materials MERL and TRI have examined two polymeric materials that are typically used for offshore umbilical applications. These two materials were Tefzel, a copolymer of ethylene and tetra...

J. W. Bulluck, R. A. Rushing

1994-01-01

320

Chemical sensors  

DOEpatents

Sensors responsive to small changes in the concentration of chemical species are disclosed, comprising a mechanicochemically responsive polymeric film capable of expansion or contraction in response to a change in its chemical environment, either operatively coupled to a transducer capable of directly converting the expansion or contraction to a measurable electrical or optical response, or adhered to a second inert polymeric strip, or doped with a conductive material.

Lowell, Jr., James R. (Bend, OR); Edlund, David J. (Bend, OR); Friesen, Dwayne T. (Bend, OR); Rayfield, George W. (Eugene, OR)

1992-01-01

321

Chemical sensors  

DOEpatents

Sensors responsive to small changes in the concentration of chemical species are disclosed, comprising a mechanicochemically responsive polymeric film capable of expansion or contraction in response to a change in its chemical environment, either operatively coupled to a transducer capable of directly converting the expansion or contraction to a measurable electrical or optical response, or adhered to a second inert polymeric strip, or doped with a conductive material. 12 figs.

Lowell, J.R. Jr.; Edlund, D.J.; Friesen, D.T.; Rayfield, G.W.

1992-06-09

322

Serum bleomycin-detectable iron in patients with thalassemia major with normal range of serum iron.  

PubMed

"Free" iron, a potentially radical-generating low mass iron, and not found in normal human blood, was increased in the serum of blood-transfused thalassemia major patients seen in the Yangon General Hospital, Yangon, Myanmar (Burma). The low mass iron was detected by the bleomycin assay. Fifty-one blood samples were analyzed (from 28 males and 23 females). High "free" iron was detected in 47 sera samples from thalassemia patients. Serum ferritin, which reflects the body store iron, was higher than the normal range (10-200 ng/ml) in 49 patients. On the other hand, serum iron of 39 sera samples fell within the normal range (50-150 micrograms/dl). Four were less than 50 micrograms/dl and eight were more than 150 micrograms/dl. Almost all the patients' sera of normal or higher serum iron level contained "free" iron. Thus, almost all the sera from thalassemic patients from Myanmar contain bleomycin-detectable iron, even when serum iron is within the normal range. In developing countries where undernutrition is prevalent (serum albumin in these patients was 3.6 +/- 0.4 g/dl, P < 0.0001 vs. control value of 4.0 - 4.8 g/dl), normal serum iron does not preclude the presence of free iron in the serum. PMID:7545860

Han, K E; Okada, S

1995-06-01

323

Influence of bottle-feeding on serum bisphenol a levels in infants.  

PubMed

Exposure to endocrine disrupting chemicals (EDCs), particularly during developmental periods, gives rise to a variety of adverse health outcomes. Bisphenol A (BPA) is a well-known EDC commonly found in plastic products including food and water containers, baby bottles, and metal can linings. This study investigates infant exposure to BPA and the effect of bottle-feeding on serum BPA levels in infants. Serum BPA levels in normal healthy infants 6 to 15 months of age (n=60) were evaluated by a competitive ELISA. BPA was detected in every study sample. Serum BPA levels of bottle-fed infants (n=30) were significantly higher than those of breast-fed infants (n=30) (96.58±102.36 vs 45.53±34.05 pg/mL, P=0.014). There were no significant differences in serum BPA levels between boys (n=31) and girls (n=29). No significant correlations were found between serum BPA levels and age, body weight, birth weight, and gestational age. Bottle-feeding seems to increase the risk of infant exposure to BPA. Establishment of health policies to reduce or prevent BPA exposure in infants is necessary. PMID:24550655

Rhie, Young-Jun; Nam, Hyo-Kyoung; Oh, Yeon Joung; Kim, Ho-Seong; Lee, Kee-Hyoung

2014-02-01

324

Serum adipokines in inflammatory bowel disease  

PubMed Central

AIM: To investigate serum adipokine levels in inflammatory bowel disease (IBD) patients before treatment and after achieving clinical remission. METHODS: Serum concentrations of six adipokines (tissue growth factor-?1, adiponectin, leptin, chemerin, resistin, and visfatin) were studied in 40 subjects with active IBD [24 subjects with Crohn’s disease (CD) and in 16 subjects with ulcerative colitis (UC)] before and after three months of therapy with corticosteroids and/or azathioprine. Clinical diagnoses were based on ileocolonoscopy, computed tomography or magnetic resonance enterography and histological examination of mucosal biopsies sampled during endoscopy. Serum levels of adipokines were assessed by an indirect enzyme-linked immunosorbent assay. The control group was comprised of 16 age- and sex-matched healthy volunteers. RESULTS: Baseline leptin concentrations were significantly decreased in both types of IBD compared to controls (8.0 ± 9.1 in CD and 8.6 ± 6.3 in UC vs 16.5 ± 10.1 ng/mL in controls; P < 0.05), and significantly increased after treatment only in subjects with CD (14.9 ± 15.1 ng/mL; P < 0.05). Baseline serum resistin concentrations were significantly higher in CD (19.3 ± 12.5 ng/mL; P < 0.05) and UC subjects (23.2 ± 11.0 ng/mL; P < 0.05) than in healthy controls (10.7 ± 1.1 ng/mL). Treatment induced a decrease in the serum resistin concentration only in UC subjects (14.5 ± 4.0 ng/mL; P < 0.05). Baseline serum concentrations of visfatin were significantly higher in subjects with CD (23.2 ± 3.2 ng/mL; P < 0.05) and UC (18.8 ± 5.3 ng/mL; P < 0.05) than in healthy controls (14.1 ± 5.3 ng/mL). Treatment induced a decrease in the serum visfatin concentrations only in CD subjects (20.4 ± 4.8 ng/mL; P < 0.05). Serum levels of adiponectin, chemerin and tissue growth factor-?1 did not differ between CD and UC subjects compared to healthy controls and also were not altered by anti-inflammatory therapy. Clinical indices of IBD activity did not correlate with adipokine levels. CONCLUSION: IBD modulates serum adipokine levels by increasing resistin and visfatin release and suppressing leptin production. PMID:24944482

Waluga, Marek; Hartleb, Marek; Boryczka, Grzegorz; Kukla, Michal; Zwirska-Korczala, Krystyna

2014-01-01

325

Serum cystatin C measured by automated immunoassay: A more sensitive marker of changes in GFR than serum creatinine  

Microsoft Academic Search

Serum cystatin C measured by automated immunoassay: A more sensitive marker of changes in GFR than serum creatinine. Serum cystatin C has been suggested as a new marker of GFR. For the introduction of this marker into clinical use a rapid and automated method is required. We have developed and validated an assay for serum cystatin C using latex particle-enhanced

David J Newman; Hansa Thakkar; Robert G Edwards; Martin Wilkie; Thomas White; Anders O Grubb; Christopher P Price

1995-01-01

326

Two new oral chemical biomarkers for coyotes.  

PubMed

Pentachlorobenzene (PeCB) and 1,2,3,4-tetrachlorobenzene (TeCB) were evaluated as oral chemical biomarkers when administered to coyotes (Canis latrans) during the period of 31 January to 10 August 1994. Three coyotes each received 100 mg of PeCB and three received 100 mg of TeCB, each in a mineral oil formulation. Three additional coyotes received only the mineral oil carrier. Muscle and adipose tissues, blood serum, and fecal samples were evaluated by capillary gas chromatography with electron capture detection for 120 days following administration. Residues of PeCB were detected in serum, feces, and adipose and muscle tissues for 120 days post-treatment; TeCB residues were detected in feces and serum at 1 and 8 days post-treatment and in adipose tissue at 30 days post-treatment. Residues of TeCB were not detected in muscle tissue at any point in the study. PMID:8827677

Kimball, B A; Windberg, L A; Furcolow, C A; Roetto, M; Johnston, J J

1996-07-01

327

Serum adenosine deaminase activity in cutaneous anthrax  

PubMed Central

Background Adenosine deaminase (ADA) activity has been discovered in several inflammatory conditions; however, there are no data associated with cutaneous anthrax. The aim of this study was to investigate serum ADA activity in patients with cutaneous anthrax. Material/Methods Sixteen patients with cutaneous anthrax and 17 healthy controls were enrolled. We measured ADA activity; peripheral blood leukocyte, lymphocyte, neutrophil, and monocyte counts; erythrocyte sedimentation rate; and C reactive protein levels. Results Serum ADA activity was significantly higher in patients with cutaneous anthrax than in the controls (p<0.001). A positive correlation was observed between ADA activity and lymphocyte counts (r=0.589, p=0.021) in the patient group. Conclusions This study suggests that serum ADA could be used as a biochemical marker in cutaneous anthrax. PMID:24997584

Sunnetcioglu, Mahmut; Karadas, Sevdegul; Aslan, Mehmet; Ceylan, Mehmet Resat; Demir, Halit; Oncu, Mehmet Resit; Karahocagil, Mustafa Kas?m; Sunnetcioglu, Aysel; Aypak, Cenk

2014-01-01

328

How does whisky lower serum urate level?  

PubMed

Clinical studies have shown that moderate whisky consumption increased renal excretion of urate into urine and decreased serum urate level, but the mechanism involved has not been established. Because renal reabsorption influences serum urate level, the effects of the whisky congeners on urate transporters, urate transporter 1 (URAT1), and voltage-driven urate transporter (URATv1) involved in reabsorptive transport of urate were examined. In transporter-expressing Xenopus oocytes, 12-year-old and 18-year-old whisky congeners inhibited urate uptake by URAT1 with IC50 values of 0.08?±?0.01 and 0.04?±?0.01?mg/mL, respectively, while urate uptake by URATv1 was inhibited only at 1?mg/mL. Decreased serum urate level after whisky consumption may be mainly due to inhibition of URAT1 by the congeners. PMID:24022993

Lu, Yang; Nakanishi, Takeo; Fukazawa, Miki; Tamai, Ikumi

2014-05-01

329

Clinical importance of thrombomodulin serum levels.  

PubMed

Thrombomodulin is a glycoprotein that can bind to thrombin and activate protein C, thus mitigating the effects of cytokines produced by inflammatory and immunological processes. The molecule exerts a protective function on endothelial cells. Thrombomodulin is cleaved to its soluble form by neutrophil elastase and by other substances produced during acute and chronic inflammatory responses, immunologic reactions and complement activation. ELISA technique yields normal serum levels of 3.1 +/- 1.3 ng/ml; in males these levels are higher; TM levels also rise during menopause. Other circumstances associated with an increase of serum TM levels are smoking, disseminated intravascular coagulation (DIC), cardiac surgery, atherosclerosis, ARDS, liver cirrhosis, diabetes mellitus, cerebral and myocardial infarction, and multiple sclerosis. Serum levels of TM represent an useful prognostic index, because they are associated with an increase in mortality rate, or however a progression of the underlying pathological condition. PMID:11558626

Califano, F; Giovanniello, T; Pantone, P; Campana, E; Parlapiano, C; Alegiani, F; Vincentelli, G M; Turchetti, P

2000-01-01

330

Proteomics and Bioinformatics Approaches for Identification of Serum Biomarkers to Detect Breast Cancer  

Microsoft Academic Search

Background: Surface-enhanced laser desorption\\/ioniza- tion (SELDI) is an affinity-based mass spectrometric method in which proteins of interest are selectively adsorbed to a chemically modified surface on a biochip, whereas impurities are removed by washing with buffer. This technology allows sensitive and high- throughput protein profiling of complex biological specimens. Methods: We screened for potential tumor biomarkers in 169 serum samples,

Jinong Li; Zhen Zhang; Jason Rosenzweig; Young Y. Wang; Daniel W. Chan

2002-01-01

331

Comparison of Two Different Methods for Inactivation of Viruses in Serum  

Microsoft Academic Search

In order to compare protocols for inactivation of viruses potentially present in biological specimens, three different model viruses were treated in bovine serum by two different inactivation methods: samples were subjected either to chemical inactivation with ethylenimine (EI) at concentrations of 5 and 10 mM at 37°C for periods up to 72 h or to electron-beam irradiation in frozen and

T. PREUSS; S. KAMSTRUP; N. C. KYVSGAARD; P. NANSEN; A. MILLER; J. C. LEI

1997-01-01

332

Concentrations of organochlorine pesticides and polychlorinated biphenyls in human serum and adipose tissue from Bolivia  

Microsoft Academic Search

Organochlorine pesticides and polychlorinated biphenyls (PCBs) are synthetic chemicals that are highly resistant to biodegradation and have proven adverse health effects. The objectives of this study were to determine concentrations of three selected organochlorine pesticides (p,p?-DDT, p,p?-DDE, HCB) and three specific PCB congeners (PCB 138, 153, 180) in adipose tissue and serum samples from an urban adult population (n=112) in

J. P. Arrebola; M. Cuellar; E. Claure; M. Quevedo; S. R. Antelo; E. Mutch; E. Ramirez; M. F. Fernandez; N. Olea; L. A. Mercado

333

Platelet lysate: a replacement for fetal bovine serum in animal cell culture?  

Microsoft Academic Search

A new cell culture supplement, platelet lysate, was evaluated with reference to fetal bovine serum (FBS), an established industrial\\u000a medium for animal cell culture. Chemical and bacteriological profiles were conducted including the presence of platelet-derived\\u000a growth factor (PDGF). PDGF was detected in the platelet lysate but it was not present in FBS. The platelet lysate medium demonstrated\\u000a lack of microorganisms,

Liselott Johansson; Jeanna Klinth; Olov Holmqvist; Sten Ohlson

2003-01-01

334

Low Serum Magnesium in Preterm Labour  

E-print Network

This study was designed to compare serum magnesium level in women with preterm labour and with those who were in term labour. A case-control study was carried out in the department of Obstetrics and Gynaecology, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka from July 2005 to June 2007, to evaluate serum magnesium level in women with preterm labour (28-36 weeks) and compare them with those who were in term labour (37-40 weeks). The total number of cases was 160, of which 80 were cases and similar number were control. The study subjects were selected from inpatient department

Of Obstetrics

335

Thermal diffusivity of human serum and plasma  

NASA Astrophysics Data System (ADS)

Using a thermal lens experimental set up, the thermal diffusivity of human serum and plasma were measured. Several samples were studied and the results are reported as the average, including the standard deviation. The samples of serum and plasma were obtained in healthy adult donors from the Guanajuato State Blood Transfusion Center, Mexico; the donors were clinically tested and they were free of hepatitis, AIDS and other infectious diseases. The parameters reported were obtained using the thermal lens aberrant model with the lasers arranged in the mismatched mode.

Mayén-Mondragón, R.; Yánez-Limón, J. M.; Palomares, P.; Sosa, M.; Bernal-Alvarado, J.

2005-06-01

336

Chemical sensors  

SciTech Connect

The revolution in analytical chemistry promised by recent developments in the field of chemical sensors has potential for significant positive impact on both research and production activities conducted by and for the Department of Energy. Analyses which were, in the past, performed only with a roomful of expensive equipment can now be performed with miniature solid-state electronic devices or small optical probes. Progress in the development of chemical sensors has been rapid, and the field is currently growing at a great rate. In accordance, Pacific Northwest Laboratory initiated a survey of recent literature so that contributors to active programs in research on analytical methods could be made aware of principles and applications of this new technology. This report presents the results of that survey. The sensors discussed here are divided into three types: micro solid-state devices, optical sensors, and piezoelectric crystal devices. The report is divided into three corresponding sections. The first section, ''Micro Solid-State Devices,'' discusses the design, operation, and application of electronic sensors that are produced in much the same way as standard solid-state electronic devices. The second section, ''Optrodes,'' covers the design and operation of chemical sensors that use fiber optics to detect chemically induced changes in optical properties. The final section, ''Piezoelectric Crystal Detectors,'' discusses two types of chemical sensors that depend on the changes in the properties of an oscillating piezoelectric crystal to detect the presence of certain materials. Advantages and disadvantages of each type of sensor are summarized in each section.

Hubbard, C.W.; Gordon, R.L.

1987-05-01

337

Low serum levels of alkaline phosphatase of bone origin: a good marker of adynamic bone disease in haemodialysis patients  

Microsoft Academic Search

Background. Adynamic bone disease was recently described to be increasingly prevalent in the dialysis population. At present the diagnosis of this type of renal osteodystrophy can only be made by bone histo- morphometry. We assessed the value of different bio- chemical serum markers in the diagnosis of adynamic bone disease. Methods. In 103 haemodialysis patients a bone biopsy was performed

M. M. Couttenye; P. C. D'Haese; V. O. Van Hoof; E. Lemoniatou; W. Goodman; G. A. Verpooten; M. E. De Broe

338

Locations of the three primary binding sites for long-chain fatty acids on bovine serum albumin  

Microsoft Academic Search

Binding of ¹³C-enriched oleic acid to bovine serum albumin and to three large proteolytic fragments of albumin - two complementary fragments corresponding to the two halved of albumin and one fragment corresponding to the carboxyl-terminal domain - yielded unique patterns of NMR resonances (chemical shifts and relative intensities) that were used to identify the locations of binding of the first

J. A. Hamilton; S. Era; S. P. Bhamidipati; R. G. Reed

1991-01-01

339

Association Between Serum Levels of Carotenoids and Serum Asymmetric Dimethylarginine Levels in Japanese Subjects  

PubMed Central

Background Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of endothelium nitric oxide synthase (NOS). ADMA binds to a substrate-binding site of NOS and then inhibits nitric oxide production from vascular endothelial cells. Elevated ADMA levels are a risk factor for cardiovascular disease. Recently, it was reported that plasma ADMA levels were negatively correlated with vegetable and fruit consumption. The purpose of this study was to examine the association between serum levels of carotenoids and serum ADMA levels in Japanese subjects. Methods We conducted a cross-sectional study of 470 subjects (203 men and 267 women) who attended a health examination in August 2011. Serum levels of several carotenoids were separately measured by high-performance liquid chromatography. Serum ADMA levels were determined by using an enzyme-linked immunosorbent assay kit. Results In women, the multivariate-adjusted odds ratios (ORs) of elevated serum ADMA levels were significantly decreased in the highest tertile for ?-cryptoxanthin (OR 0.47, 95% CI 0.23–0.95), ?-carotene (OR 0.39, 95% CI 0.18–0.79), and ?-carotene (OR 0.36, 95% CI 0.17–0.73) compared to the lowest tertile. In men, significantly decreased ORs were observed in the highest tertiles of serum zeaxanthin/lutein (OR 0.23, 95% CI 0.06–0.69) and ?-carotene (OR 0.26, 95% CI 0.07–0.82), and in the middle and the highest tertiles of serum ?-carotene (OR 0.27, 95% CI 0.09–0.74 and OR 0.20, 95% CI 0.03–0.88, respectively) when the tertile cutoff points of women were extrapolated to men. Conclusions Higher serum levels of carotenoids, such as ?-carotene and ?-carotene, may help to prevent elevated serum ADMA levels in Japanese subjects. PMID:24727752

Watarai, Rika; Suzuki, Koji; Ichino, Naohiro; Osakabe, Keisuke; Sugimoto, Keiko; Yamada, Hiroya; Hamajima, Takeshi; Hamajima, Nobuyuki; Inoue, Takashi

2014-01-01

340

Putrescine-oxidase activity in adult bovine serum and fetal bovine serum  

Microsoft Academic Search

Summary  Putrescine-oxidase activity was found in fetal bovine serum (FBS) with a pH optimum of 8.0 and in adult bovine serum (ABS)\\u000a with a pH optimum of 9.8. The crude FBS enzyme had a KM for putrescine of 2.58×10?6\\u000a m and a Vmax of 0.53 nmol per hr per 50 ?l serum. Aminoguanidine competitively inhibited the enzyme with a KI of

William A. Gahl; Henry C. Pitot

1979-01-01

341

Exercise and Serum Androgens in Women.  

ERIC Educational Resources Information Center

This study examining the effect of a 10-week hydraulic resistance exercise program on serum androgen levels, strength, and lean body weight in 18 college women revealed that training did not result in significant increases in androgen hormones, although there were significant gains in strength. (Author/CB)

Westerlind, Kim C.; And Others

1987-01-01

342

Determination of triiodothyronine concentration in human serum  

PubMed Central

A simplified method has been described for the measurement of triiodothyronine (T3) in human serum. The sensitivity was sufficient for determinations on hypothyroid as well as normal and thyrotoxic sera. The values obtained have been in reasonable agreement with a double isotope derivative assay. The normal T3 concentration in human serum approximates 0.2 ?g/100 ml; the mean ±SD of 31 normal sera was 220 ±27 ng/100 ml. Elevations were observed in sera from 40 patients with thyrotoxicosis (752 ±282 ng/100 ml), and diminutions were found in sera from 10 hypothyroid patients (98±48 ng/100 ml). In rare instances thyrotoxicosis may be due to elevated serum T3 with normal thyroxine (T4) concentration. The incidence of this condition remains to be determined. In approximately half the cases with low serum T4 after 131I therapy, the eumetabolic state may be maintained by normal or elevated T3 concentration. From these data and kinetic studies indicating a rapid turnover it may be inferred that T3 rather than T4 may be the more important hormone in health and in disease. Images PMID:5771194

Sterling, Kenneth; Bellabarba, Diego; Newman, Edward S.; Brenner, Milton A.

1969-01-01

343

A Micro Method for Serum Cholinesterase  

Microsoft Academic Search

A simple colorimetric method for determining serum or plasma cholinesterase has been described. The cholinesterase acts on acetyithiocholine to release thiocholine, which reacts with 5:5-dithiobis- (2-nitrobenzoic acid) to produce a yellow color. The activity is measured after incubation for 3 mm. at 370; the reaction is stopped by the excess addition of quinidine sulfate. The difference in absorbancebetween the blank

Phil J. Garry; Joseph I. Routh

344

Serum-free cryopreservation of porcine hepatocytes.  

PubMed

The use of porcine hepatocytes in xenotransplantation, bioartificial liver support or pharmacological approaches demands serum-free cryopreservation protocols yielding high quality, viable, functional hepatocytes. Here, primary porcine hepatocytes were frozen without serum in liquid nitrogen by the use of a computer-assisted freezing device. After thawing, more than 90% of the initial hepatocytes were lost, in part because of damage to genomic DNA. When cryoprotectants were used, the loss was lowered to 70% of the initial cell number; 90% of the remaining cells excluded trypan blue indicating a high degree of viability. Cells were seeded serum-free onto collagen-coated plastic dishes to determine proliferation and retainment of specific functions representing prominent features of hepatocytes in vivo. Whereas no cells adhered to the substratum effectively in conventional culture medium, the addition of conditioned medium derived from hepatic non-parenchymal cells improved attachment. Cells proliferated, retained hepatocyte-specific functions, such as urea production and cytochrome P450 activity, and expressed liver-specific genes to levels observed in non-cryopreserved hepatocytes. Thus, serum-free cryopreserved primary porcine hepatocytes may serve as a valid source of cells for downstream applications. The cells seem to function adequately when an appropriate environment is chosen for recovery after cryopreservation, an ultimate demand for the clinical application of human hepatocytes. PMID:15185140

Müller, Peggy; Aurich, Hendryk; Wenkel, Ralph; Schäffner, Ines; Wolff, Ilona; Walldorf, Jens; Fleig, Wolfgang E; Christ, Bruno

2004-07-01

345

Serum selenium and colonic neoplastic risk  

Microsoft Academic Search

BACKGROUND: Selenium deficiency has been associated with cancer risk in several organs. This association was investigated in neoplasia of the colorectum. DESIGN: A case-control study is reported with two patient series, colorectal cancer and colorectal adenomatous polyps, and a control group found to be free of colorectal neoplasia. Diagnosis was determined by colonoscopy and histologic review of suspected neoplasms. Serum

Richard L. Nelson; Faith G. Davis; Eileen Sutter; J. Walter Kikendall; Leslie H. Sobin; John A. Milner; Phyllis E. Bowen

1995-01-01

346

Serum lipids and cardiovascular reactivity to stress  

Microsoft Academic Search

Several studies have reported an association between serum lipid levels and cardiovascular reactivity to laboratory stressors. Their findings, however, are equivocal. The inconsistencies may be due to shortcomings such as the small number of subjects, the inclusion of patient groups, no control for medication, and no control for age effects. Two studies are presented investigating the relationship in large groups

Lorenz J. P. van Doornen; Harold Snieder; Dorret I. Boomsma

1998-01-01

347

Adsorption of bovine serum albumin onto hydroxyapatite  

Microsoft Academic Search

The adsorption of bovine serum albumin (BSA) onto hydroxyapatite (HA) has been studied as a function of protein concentration, pH and ionic strength. Isotherm data (adsorption being a reversible process) have been analysed using the Langmuir model, the adsorption parameters AT (maximum amount of protein adsorbed, mg m?2) and K (affinity constant, L g?1) being calculated for each solution condition

Diana T. Hughes Wassell; Rachel C. Hall; Graham Embery

1995-01-01

348

Serum CA 125 levels and spontaneous abortion  

Microsoft Academic Search

OBJECTIVE: Previous reports have suggested that serum CA 125 levels in patients who spontaneously abort in the first trimester of pregnancy differ from the levels of patients who successfully complete their pregnancies. Low CA 125 levels have been suggested to predict spontaneous abortion, although an increased rate of first-trimester spontaneous abortion has also been reported in women with elevated CA

Mark D. Hornstein; Jerome H. Check; Joseph A. Hill

1995-01-01

349

Effect of chronic metoclopramide therapy on serum pituitary hormone concentrations.  

PubMed

The effect of chronic (3--9 months) therapy with metoclopramide on serum levels of pituitary and thyroid hormones was studied in 4 males and 1 female. The mean serum prolactin concentration during metoclopramide therapy was significantly higher than after discontinuation of metoclopramide. Serum prolactin concentrations increased acutely after each dose of metoclopramide. Serum prolactin concentrations increased acutely after each dose of metoclopramide, and gradually returned to normal by 6--12 h. There was no sifgnificant differences in the serum TSH, T3, T4, GH, and gonadotrophin levels during and after metoclopramide administration. In the male subjects the mean serum testosterone was normal, but significantly lower during metoclopramide therapy. PMID:574121

Tamagna, E I; Lane, W; Hershman, J M; Carlson, H E; Sturdevant, R A; Poland, R E; Rubin, R T

1979-01-01

350

Chemical Mahjong  

ERIC Educational Resources Information Center

An open-access, Web-based mnemonic game is described whereby introductory chemistry knowledge is tested using mahjong solitaire game play. Several tile sets and board layouts are included that are themed upon different chemical topics. Introductory tile sets can be selected that prompt the player to match element names to symbols and metric…

Cossairt, Travis J.; Grubbs, W. Tandy

2011-01-01

351

Delicious Chemicals.  

ERIC Educational Resources Information Center

This paper presents an approach to chemistry and nutrition that focuses on food items that people consider delicious. Information is organized according to three categories of food chemicals that provide energy to the human body: (1) fats and oils; (2) carbohydrates; and (3) proteins. Minerals, vitamins, and additives are also discussed along with…

Barry, Dana M.

352

Chemical Evolution  

E-print Network

In this series of lectures we first describe the basic ingredients of galactic chemical evolution and discuss both analytical and numerical models. Then we compare model results for the Milky Way, Dwarf Irregulars, Quasars and the Intra-Cluster- Medium with abundances derived from emission lines. These comparisons allow us to put strong constraints on the stellar nucleosynthesis and the mechanisms of galaxy formation.

Francesca Matteucci

2007-04-05

353

Chemical Wonders  

NSDL National Science Digital Library

Students are introduced to chemical engineering and learn about its many different applications. They are provided with a basic introduction to matter and its different properties and states. An associated hands-on activity gives students a chance to test their knowledge of the states of matter and how to make observations using their five senses: touch, smell, sound, sight and taste.

Integrated Teaching And Learning Program

354

Chemical Changes  

NSDL National Science Digital Library

This is an excellent resource for teachers and students. It offers countless lab ideas for teaching chemical and physical changes and is geared for fifth through eighth grade. It also gives interactive web addresses for students and includes PowerPoint presentations on this topic.

can't tell- a science educator- not affiliated with any specific organization

2011-10-10

355

Effect of altitude training on serum creatine kinase activity and serum cortisol concentration in triathletes  

Microsoft Academic Search

In this investigation we evaluated the effect of a 5-week training program at 1860?m on serum creatine kinase (CK) activity\\u000a and serum cortisol concentration in national-caliber triathletes for the purpose of monitoring the response to training in\\u000a a hypobaric hypoxic environment. Subjects included 16 junior-level female (n?=?8) and male (n?=?8) triathletes who were training for the International Triathlon Union (ITU)

R. L. Wilber; S. D. Drake; J. L. Hesson; J. A. Nelson; J. T. Kearney; G. M. Dallam; L. L. Williams

2000-01-01

356

The subsequent effect of interaction between Co 2+ and human serum albumin or bovine serum albumin  

Microsoft Academic Search

A notable hysteretic effect has been observed in the interaction of Co(II) with human serum albumin (HSA) or bovine serum albumin (BSA) using UV–Visible spectrometry at physiological pH (7.43), which shows that the binding between Co(II) and HSA or BSA may induce a slow transition of HSA or BSA from the conformation of weaker affinity for Co(II) to one of

Hong Liang; Jin Huang; Chu-Qiao Tu; Min Zhang; Yong-Qia Zhou; Pan-Wen Shen

2001-01-01

357

Increased Serum Alkaline Phosphatase and Serum Phosphate as Predictors of Mortality after Stroke  

PubMed Central

Context: Serum Alkaline phosphatase (ALP) & phosphate are considered to be indicators of vascular calcification. Link between bone metabolism, vascular calcification, cardiovascular events have been well studied in chronic kidney disease and ischemic heart disease. Aims: To determine that increased serum phosphate and alkaline phosphatase are predictors of mortality rates and recurrent vascular events in stroke. Materials and Methods: Sixty patients admitted with acute stroke (ischemic & haemorrhagic) were included in the study. Their baseline clinical characteristics and biochemical parameters including serum ALP and phosphate were noted. All patients were followed up for a period of one year. The all- cause mortality, the mortality due to cardiovascular events and recurrent vascular events without death were noted during the follow up. Statistical analyses were done to look for any correlation between mortality and baseline levels of serum ALP and phosphate. Results: Of the 60 patients, 8 (13.3%) patients were lost for follow up. Fourteen (26.9%) patients died; of which 12 deaths were due to vascular causes and 2 deaths were due to non vascular causes. Increasing levels of serum ALP and phosphate correlated with all cause mortality and recurrent vascular events without death Conclusion: Serum ALP and phosphate prove to be cost effective prognostic indicator of mortality and recurrent vascular events in stroke. This finding has to be confirmed with studies including larger population. Further research on ALP inhibitors, Vitamin D analogues and phosphate binders to improve mortality in stroke population can be encouraged.

S, Pratibha; JB, Agadi

2014-01-01

358

9 CFR 147.2 - The rapid serum test. 2  

...rapid serum test. 2 147.2 Section 147.2 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT...PROVISIONS ON NATIONAL POULTRY IMPROVEMENT PLAN Blood Testing Procedures § 147.2 The rapid serum...

2014-01-01

359

9 CFR 147.2 - The rapid serum test. 2  

Code of Federal Regulations, 2011 CFR

...rapid serum test. 2 147.2 Section 147.2 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT...PROVISIONS ON NATIONAL POULTRY IMPROVEMENT PLAN Blood Testing Procedures § 147.2 The rapid serum...

2011-01-01

360

9 CFR 147.2 - The rapid serum test. 2  

Code of Federal Regulations, 2010 CFR

...rapid serum test. 2 147.2 Section 147.2 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT...PROVISIONS ON NATIONAL POULTRY IMPROVEMENT PLAN Blood Testing Procedures § 147.2 The rapid serum...

2010-01-01

361

9 CFR 147.2 - The rapid serum test. 2  

Code of Federal Regulations, 2013 CFR

...rapid serum test. 2 147.2 Section 147.2 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT...PROVISIONS ON NATIONAL POULTRY IMPROVEMENT PLAN Blood Testing Procedures § 147.2 The rapid serum...

2013-01-01

362

9 CFR 147.2 - The rapid serum test. 2  

Code of Federal Regulations, 2012 CFR

...rapid serum test. 2 147.2 Section 147.2 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT...PROVISIONS ON NATIONAL POULTRY IMPROVEMENT PLAN Blood Testing Procedures § 147.2 The rapid serum...

2012-01-01

363

Original article Serum creatine kinase activity as a selection  

E-print Network

Original article Serum creatine kinase activity as a selection criterion for stress susceptibility July 1991) Summary ― Estimation of serum creatine kinase isoenzyme activity was used sensitivity. creatine kinase isoenzymes / pig / standardized stress / halothane anaesthesia / ACTH / syn

Paris-Sud XI, Université de

364

Chemical peel.  

PubMed

Chemical face peeling as described in this article produces gross and microscopic changes in the skin which are permanent. The most important aspect in assuring the success of this procedure is the proper selection of patients. The primary use of this procedure is for the purpose of eliminating wrinkles, whether as the primary or ancillary procedure, such as regional peeling. Chemical peeling of the face is a valuable adjunct in the treatment of the aging face and can produce some rather dramatic results with the careful selection of patients and meticulous attention to detail in carrying out the peel, as well as the exact adherence to the post peel instructions by the patient. PMID:639446

Mosienko, P; Baker, T J

1978-01-01

365

Chemical warfare  

PubMed Central

Leaf-cutting ants are well known for their highly complex social organization, which provides them with a strong defense against parasites invading their colonies. Besides this attribute, these insects have morphological, physiological and structural characteristics further reinforcing the defense of their colonies. With the discovery of symbiotic bacteria present on the integument of leaf-cutting ants, a new line of defense was proposed and considered to be specific for the control of a specialized fungal parasite of the ants’ fungus gardens (Escovopsis). However, recent studies have questioned the specificity of the integumental bacteria, as they were also found to inhibit a range of fungi, including entomopathogens. The microbiota associated with the leaf-cutting ant gardens has also been proposed as another level of chemical defense, protecting the garden from parasite invasion. Here we review the chemical defense weaponry deployed by leaf-cutting ants against parasites of their fungus gardens and of the ants themselves. PMID:23795235

Samuels, Richard Ian; Mattoso, Thalles Cardoso; Moreira, Denise D.O.

2013-01-01

366

Chemical Reactions  

NSDL National Science Digital Library

We are going go over a general view of reactions to prepare us for our unit on Chemical Reactions! Have fun learning! WARNING: If you are caught looking at ANY other site, without permission, you will be sent to the ALC, and you will not participate in any other computer activities for the rest of the year. Get your worksheet and begin! Overview Take this quiz and have me come over and sign off on your worksheet when you have completed the quiz! Overview Quiz Next let's take a look at what effect the rate of a chemical reaction. Rates of Reactions Another quiz, another check off by me! Rates of Reactions Quiz Now how do we measure how fast a ...

Hicken, Mrs.

2009-05-04

367

Proteomic expression profiling and identification of serum proteins using immobilized trypsin beads with MALDI-TOF/TOF.  

PubMed

MALDI-TOF mass spectrometry is a widely used technique for serum protein expression profiling and biomarker discovery. Many profiling strategies typically employ chemical affinity beads or surfaces to decrease sample complexity of dynamic fluids such as serum or plasma. However, many of the proteins captured on a particular surface or bead are not resolved in the lower mass ranges where time-of-flight mass spectrometers are most effective. Thus, a majority of reported protein expression profiling studies primarily interrogate the native low molecular mass constituents of the target sample. We report an expression profiling workflow that utilizes immobilized trypsin paramagnetic beads following an initial affinity bead fractionation step, thereby reducing large mass proteins to peptides that are better suited to analysis and sequencing determinations. Our bead-based trypsin approach resulted in more efficient digestion of complex serum protein extracts at short incubation times. This method was reproducible and readily adaptable to robotic sample handling and may be combined in tandem with other bead fractionation surfaces. When weak cationic and weak anionic bead surfaces were used, experimental conditions were optimized for tandem combinations of these beads with the immobilized trypsin step to produce an efficient serum fractionation strategy. A proof-of-concept pilot experiment using pooled human serum samples demonstrating reproducibility is presented, along with the sequence determination of selected tryptic peptides of serum proteins. PMID:19603828

Karbassi, Izabela D; Nyalwidhe, Julius O; Wilkins, Christopher E; Cazares, Lisa H; Lance, Raymond S; Semmes, O John; Drake, Richard R

2009-09-01

368

Surface characterization of titanium and adsorption of bovine serum albumin  

SciTech Connect

The surface oxide films on titanium were characterized and the relationship between the characterization and the adsorption of bovine serum albumin (BSA) on titanium was studied. The surface oxide films on titanium were obtained by heat-treatment in different oxidizing atmospheres, such as air and water vapor. The surface roughness, energy, morphology, chemical composition and crystal structure were used to characterize the titanium surfaces. The characterization was performed using a profilometer, scanning electronic microscopy (SEM), a sessile drop method, X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). Percentages of surface hydroxyl groups were determined by XPS analysis for the titanium plates and the densities were measured by a chemical method for titanium powders. After heat-treatment, the titanium surfaces were uniformly roughened and the surface titanium oxide was predominantly rutile TiO{sub 2}. The crystal planes in the rutile films were preferentially orientated in the (110) plane with the highest density of titanium ions. Heat-treatment increased the surface energy and the amount of surface hydroxyl groups on the titanium. The different oxidizing atmospheres resulted in different percentages of oxygen species in the TiO{sub 2}, in the physisorbed water and acidic hydroxyl groups and in the basic hydroxyl groups on the titanium surfaces. The analysis for the adsorption of BSA on titanium confirmed that the surface characterization of titanium has a strong effect on the bioactivity of titanium. The BSA chemically adsorbed onto the titanium surfaces. The adsorption of BSA on the titanium surfaces was positively related with the amounts of their surface hydroxyl groups, including basic hydroxyl groups and acidic hydroxyl groups, and the values of the polar component of the total surface energy.

Feng, B.; Weng, J.; Yang, B.C.; Chen, J.Y.; Zhao, J.Z.; He, L.; Qi, S.K.; Zhang, X.D

2002-09-15

369

Comparison of two immunoradiometric assays for serum thyrotropin  

SciTech Connect

An ultra-sensitive TSH assay capable of detecting subnormal TSH levels would be useful in confirming suppressed pituitary function as seen in hyperthyroidism. Two sensitive immunoradiometric TSH assays (IRMA's) were studied to determine how well they distinguished thyrotoxic patients from normal subjects. Serono Diagnostics' method employs three monoclonal antibodies specific for different regions of the TSH molecule with a minimum detectable dose (MDD) limit of 0.1 ..mu..IU/ml. Precision studies using a low TSH control in the 1.8 ..mu..IU/ml range gave CV's of 15.0%. Boots-Celltech Diagnostics method is a two site IRMA using two monoclonal antibodies. The MDD limit is 0.05 ..mu..IU/ml with precision CV's of 29.3% at a TSH control range of 0.62 ..mu..IU/ml. In 24 chemically thyrotoxic patients, the mean serum TSH concentration was significantly lower than in the normal control subjects: for Serono, 0.19 ..mu..IU/ml vs. 2.34 ..mu..IU/ml and for Boots Celltech, 0.18 IU/ml vs 2.06 ..mu..IU/ml. The range of TSH was 0 to 0.5 ..mu..IU/ml in thyrotoxic patients using Serono with the exception of one patient having a TSH value of 0.8 ..mu..IU/ml. The normal range was 0.6 to 6.0 ..mu..IU/ml. For Boots Celltech the thyrotoxic range was 0 to 0.2 ..mu..IU/ml with that same thyrotoxic patient giving a TSH value of 0.7 ..mu..IU/ml with a normal range of 0.6 to 5.0 IU/ml. Serum TSH measurements using both procedures are highly sensitive for distinguishing thyrotoxic patients from normal subjects and are useful to confirm suppressed pituitary function.

Scheinin, B.; Drew, H.; La France, N.; Ladenson, P.; Wagner, H.N. Jr.

1985-05-01

370

Developmental toxicity and serum levels of perfluorononanoic acid in the wild-type and PPAR-alpha knockout mouse after gestational exposure  

EPA Science Inventory

Perfluorononanoic acid (PFNA) is a perfluoroalkyl acid detected in.the environment and in tissues of humans and wildlife. PFNA activates peroxisome proliferator-activated receptor-alpha (PPARa) in vitro and negatively impacts development and survival of CD1 mice. Our objective wa...

371

Determinants of Serum Leptin Levels in Cushing's Syndrome  

Microsoft Academic Search

Corticosteroids and insulin increase leptin expression in vivo and in vitro. To investigate whether increased serum cortisol influences serum leptin concentrations in humans, we analyzed fasting serum leptin and insulin levels in 50 patients with Cushing's syndrome (34 female patients: 27 with the pituitary form and 7 with the adrenal form; age, 41.6 6 2.7 yr; body mass index (BMI),

ADJI WIDJAJA; THOMAS H. SCHURMEYER; GEORG BRABANT

2010-01-01

372

Quantifying Serum Antiplague Antibody with a Fiber-Optic Biosensor  

Microsoft Academic Search

The fiber-optic biosensor, originally developed to detect hazardous biological agents such as protein toxins or bacterial cells, has been utilized to quantify the concentration of serum antiplague antibodies. This biosensor has been used to detect and quantify the plague fraction 1 antigen in serum, plasma, and whole-blood samples, but its ability to quantify serum antibodies has not been demonstrated. By

GEORGE P. ANDERSON; KEELEY D. KING; LYNN K. CAO; MEAGAN JACOBY; FRANCES S. LIGLER; JOHN EZZELL; Fort Detrick

1998-01-01

373

Serum ferritin concentration and iron stores in normal subjects  

Microsoft Academic Search

The relationship between serum ferritin concentration and the amount of storage iron has been studied in normal subjects. A high degree of correlation was demonstrated between serum ferritin concentration and storage iron measured by quantitative phlebotomy. The possible advantages of assessing iron stores by using the serum ferritin concentration are discussed.

G. O. Walters; F. M. Miller; M. Worwood

1973-01-01

374

Transition of serum vitellogenin cycle in Sakhalin taimen ( Hucho perryi)  

Microsoft Academic Search

A specific and sensitive enzyme-linked immunosorbent assay (ELISA) and a single radial immunodiffusion (SRID) were developed for measurement of serum vitellogenin (Vg) levels in Sakhalin taimen (Hucho perryi). Regarding specificity for serum Vg, an antiserum raised against lipovitellin of taimen (a-Lv) was adequate for both assays. ELISA and SRID could detect Vg in serum at concentrations as low as 10

Naoshi Hiramatsu; Munetaka Shimizu; Haruhisa Fukada; Makiko Kitamura; Kazuhiro Ura; Hirotoshi Fuda; Akihiko Hara

1997-01-01

375

Diagnositic value of serum bile acid estimations in liver disease  

Microsoft Academic Search

Bile acid concentrations were estimated enzymatically in fasting and postprandial (two-hour) serum samples from 18 normal subjects and 30 patients with histologically proven hepatobiliary disease. The serum bile acid concentration was less than 15 mumol\\/1 in normal subjects and did not increase postprandially. The fasting serum bile acid concentration was raised in 27 of the patients with hepatobiliary disease, and

S Barnes; G A Gallo; D B Trash; J S Morris

1975-01-01

376

Serum bilirubin: a prognostic factor in primary biliary cirrhosis  

Microsoft Academic Search

We followed up 55 patients with proven primary biliary cirrhosis for several years or until death. A graph of the level of serum bilirubin versus time that was constructed for each patient shows an initial period of variable length in which the serum bilirubin level remained constant. This was followed by a period of rapid rise in serum bilirubin which

J M Shapiro; H Smith; F Schaffner

1979-01-01

377

21 CFR 610.16 - Total solids in serums.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Total solids in serums. 610.16 Section 610.16 Food...Provisions § 610.16 Total solids in serums. Except as otherwise provided by regulation, no liquid serum or antitoxin shall contain more than...

2013-04-01

378

21 CFR 522.1079 - Serum gonadotropin and chorionic gonadotropin.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Serum gonadotropin and chorionic gonadotropin...FORM NEW ANIMAL DRUGS § 522.1079 Serum gonadotropin and chorionic gonadotropin...consists of 400 international units (I.U.) serum gonadotropin and 200 I.U....

2013-04-01

379

21 CFR 610.16 - Total solids in serums.  

...2014-04-01 false Total solids in serums. 610.16 Section 610.16 Food...Provisions § 610.16 Total solids in serums. Except as otherwise provided by regulation, no liquid serum or antitoxin shall contain more than...

2014-04-01

380

21 CFR 610.16 - Total solids in serums.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 false Total solids in serums. 610.16 Section 610.16 Food...Provisions § 610.16 Total solids in serums. Except as otherwise provided by regulation, no liquid serum or antitoxin shall contain more than...

2012-04-01

381

21 CFR 522.1079 - Serum gonadotropin and chorionic gonadotropin.  

...2014-04-01 2014-04-01 false Serum gonadotropin and chorionic gonadotropin...FORM NEW ANIMAL DRUGS § 522.1079 Serum gonadotropin and chorionic gonadotropin...consists of 400 international units (I.U.) serum gonadotropin and 200 I.U....

2014-04-01

382

21 CFR 522.1079 - Serum gonadotropin and chorionic gonadotropin.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Serum gonadotropin and chorionic gonadotropin...FORM NEW ANIMAL DRUGS § 522.1079 Serum gonadotropin and chorionic gonadotropin...consists of 400 international units (I.U.) serum gonadotropin and 200 I.U....

2012-04-01

383

Iron and ADHD: Time to Move beyond Serum Ferritin Levels  

ERIC Educational Resources Information Center

Objective: (a) To compare serum ferritin levels in a sample of stimulant-naive children with ADHD and matched controls and (b) to assess the association of serum ferritin to ADHD symptoms severity, ADHD subtypes, and IQ. Method: The ADHD and the control groups included 101 and 93 children, respectively. Serum ferritin levels were determined with…

Donfrancesco, Renato; Parisi, Pasquale; Vanacore, Nicola; Martines, Francesca; Sargentini, Vittorio; Cortese, Samuele

2013-01-01

384

A serum-free Vero production platform for a chimeric virus vaccine candidate.  

PubMed

MedImmune Vaccines has engineered a live, attenuated chimeric virus that could prevent infections caused by parainfluenza virus type 3 (PIV3) and respiratory syncytial virus (RSV), causative agents of acute respiratory diseases in infants and young children. The work here details the development of a serum-free Vero cell culture production platform for this virus vaccine candidate. Efforts to identify critical process parameters and optimize culture conditions increased infectious virus titers by approximately 2 log(10) TCID(50)/ml over the original serum-free process. In particular, the addition of a chemically defined lipid concentrate to the pre-infection medium along with the shift to a lower post-infection cultivation temperature increased virus titers by almost 100-fold. This improved serum-free process achieved comparable virus titers to the serum-supplemented process, and demonstrated consistent results upon scale-up: Vero cultures in roller bottles, spinner flasks and bioreactors reproducibly generated maximum infectious virus titers of 8 log(10) TCID(50)/ml. PMID:19002888

Yuk, Inn H; Lin, Gina B; Ju, Hui; Sifi, Inesse; Lam, Yvonne; Cortez, Armida; Liebertz, Danny; Berry, J Michael; Schwartz, Richard M

2006-07-01

385

Dye attached poly(hydroxyethyl methacrylate) cryogel for albumin depletion from human serum.  

PubMed

Cibacron Blue F3GA was immobilized on poly(hydroxyethyl methacrylate) cryogel and it was used for selective and efficient depletion of albumin from human serum. The poly(hydroxyethyl methacrylate) was selected as the basic component because of its inertness, mechanical strength, chemical and biological stability, and biocompatibility. Cibacron Blue F3GA was covalently attached to the poly(hydroxyethyl methacrylate) cryogel to produce poly(hydroxyethyl methacrylate)-Cibacron Blue F3GA cryogel affinity column. The poly(hydroxyethyl methacrylate)-Cibacron Blue F3GA cryogel was characterized with respect to gelation yield, swelling degree, total volume of macropores, Fourier Transform Infrared spectroscopy, and scanning electron microscopy. It was found that the maximum amount of adsorption (343 mg/g of dry cryogel) obtained from experimental results is very close to the calculated Langmuir adsorption capacity (345 mg/g of dry cryogel). The maximum adsorption capacity for poly(hydroxyethyl methacrylate)-Cibacron Blue F3GA cryogel column was obtained as 950 mg/g of dry cryogel for nondiluted serum. The adsorption capacity decreased with increasing dilution ratios while the depletion ratio of albumin remained as 77% in serum sample. Finally, the poly(hydroxyethyl methacrylate)-Cibacron Blue F3GA cryogel was optimized for using in the fast protein liquid chromatography system for rapid removal of the high abundant proteins from the human serum. PMID:22556120

Andac, Muge; Galaev, Igor; Denizli, Adil

2012-05-01

386

Mammalian serum albumins as a chiral mediator library for bio-supramolecular photochirogenesis: optimizing enantiodifferentiating photocyclodimerization of 2-anthracenecarboxylate.  

PubMed

A simple strategy for choosing optimal bio-supramolecular mediators from the mammalian serum albumin library is proposed for bimolecular photochirogenic reactions. Thus, the enantiodifferentiating photocyclodimerization of 2-anthracencecarboxylate (AC) was optimized in chemical and optical yields, when mediated by porcine and canine serum albumins, both of which bound two AC molecules in the first productive site to give the (P)-enantiomer of syn-head-to-tail-cyclodimer in 69% yield and 89% enantiomeric excess (ee) for the former but the (M)-enantiomer in 77% yield and 97% ee for the latter. PMID:25072951

Nishijima, Masaki; Goto, Masato; Fujikawa, Mayu; Yang, Cheng; Mori, Tadashi; Wada, Takehiko; Inoue, Yoshihisa

2014-10-21

387

The Human Plasma and Serum Proteome  

Microsoft Academic Search

Human plasma and serum are the preferred specimens for noninvasive studies of normal and disease-associated proteins in the\\u000a circulation and arising from cells throughout the body. The attributes of extreme complexity, very wide dynamic range, genetic\\u000a and physiological variation, endogenous and ex vivo modifications, and incompleteness of sampling by mass spectrometry all\\u000a represent major challenges to reproducible, high-resolution, high-throughput analyses

Gilbert S. Omenn; Rajasree Menon; Marcin Adamski; Thomas Blackwell; Brian B. Haab; Weimin Gao; David J. States

388

Rabbit serum albumin hydrolyzes the carbamate carbaryl.  

PubMed

One of the main detoxification processes of the carbamate insecticides is the hydrolysis of the carbamic ester bond. Carboxylesterases seem to play important roles in the metabolization of carbamates. This study performs a biochemical characterization of the capabilities of rabbit serum albumin (RSA) to hydrolyze the carbamate carbaryl. Rabbit serum albumin was able to hydrolyze carbaryl with a K(cat) of 7.1 x 10(-5) s(-1). The K(m) for this hydrolysis reaction was 240 microM. Human, chicken, and bovine serum albumins were also able to hydrolyze carbaryl. The divalent cation Cu(2+) at 1 mM concentration inhibited around 50% of the hydrolysis of carbaryl by RSA. Other mono- and divalent cations at 1 mM concentration and 5 mM EDTA exerted no significant effects on the hydrolysis of carbaryl by RSA. The inhibition of the carbaryl hydrolysis by sulfydril blocking agents suggests that a cysteine residue plays an important role in the active center of the catalytic activity. Both caprylic and palmitic acids were noncompetitive inhibitors of the carbaryl hydrolysis by RSA. The carboxyl ester p-nitrophenyl butyrate is a substrate of RSA and competitively inhibited the hydrolysis of carbaryl by this protein, suggesting that the hydrolysis of carbaryl and the hydrolysis of carboxyl esters occur in the same catalytic site and through a similar mechanism. This mechanism might be based on the carbamylation of a tyrosine residue of the RSA. Serum albumin is a protein universally present in nontarget species of insecticides; therefore, the capability of this protein to hydrolyze other carbamates must be studied because it might have important toxicological and ecotoxicological implications. PMID:11952338

Sogorb, Miguel A; Carrera, Victoria; Benabent, Mónica; Vilanova, Eugenio

2002-04-01

389

Determination of Total Cholesterol in Hypertriglyceridemic Serums  

Microsoft Academic Search

The determination of serum total cholesterol by a direct reaction involving a Trinder-type enzymic pathway can be severely hampered by the turbidity caused by excessive concentrations of triglyceride-rich lipoproteins such as very-low-density lipoproteins and chylomicrons. This paper describes a clarification procedure that effectively removes such turbidity by a process involving lipolysis of triglycerides and entrapment of the liberated nonesterified fatty

B. R. Morgan; J. D. Artiss; B. Zak

1998-01-01

390

Depletion of TGF-? from fetal bovine serum  

Microsoft Academic Search

TGF-? is one of the key cytokines controlling immune responses. Measuring TGF-? from culture supernatants in vitro is an important index of immune function. However, fetal bovine serum (FBS) contains a high level of latent TGF-? that often hampers measuring T cell-derived TGF-? in culture using FBS-supplemented medium. In this report, we generated anti-latency associated peptide (LAP) monoclonal antibodies which

Takatoku Oida; Howard L. Weiner

2010-01-01

391

Interaction of wogonin with bovine serum albumin  

Microsoft Academic Search

The binding of wogonin with bovine serum albumin (BSA) was investigated at different temperatures by fluorescence, circular dichroism (CD) and Fourier transform infrared spectroscopy (FT-IR) at pH7.40. The association constants K were determined by Stern–Volmer equation based on the quenching of the fluorescence of BSA in the presence of wogonin, which were in agreement with the constants calculated by Scatchard

Jianniao Tian; Jiaqin Liu; Zhide Hu; Xingguo Chen

2005-01-01

392

Prediction of Creatinine Clearance from Serum Creatinine  

Microsoft Academic Search

A formula has been developed to predict creatinine clearance (Ccr) from serum creatinine (Scr) in adult males: Ccr = (140 – age) (wt kg)\\/72 × Scr(mg\\/100ml) (15% less in females). Derivation included the relationship found between age and 24-hour creatinine excretion\\/kg in 249 patients aged 18–92. Values for Ccr were predicted by this formula and four other methods and the

Donald W. Cockcroft; Henry Gault

1976-01-01

393

The University of Michigan Dioxin Exposure Study: Predictors of Human Serum Dioxin Concentrations in Midland and Saginaw, Michigan  

PubMed Central

Background We conducted a population-based human exposure study in response to concerns among the population of Midland and Saginaw counties, Michigan, that discharges by the Dow Chemical Company of dioxin-like compounds into the nearby river and air had led to an increase in residents’ body burdens of polychlorinated dibenzofurans (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (PCBs), here collectively referred to as “dioxins.” Objectives We sought to identify factors that explained variation in serum dioxin concentrations among the residents of Midland and Saginaw counties. Exposures to dioxins in soil, river sediments, household dust, historic emissions, and contaminated fish and game were of primary interest. Methods We studied 946 people in four populations in the contaminated area and in a referent population, by interview and by collection of serum, household dust, and residential soil. Linear regression was used to identify factors associated with serum dioxins. Results Demographic factors explained a large proportion of variation in serum dioxin concentrations. Historic exposures before 1980, including living in the Midland/Saginaw area, hunting and fishing in the contaminated areas, and working at Dow, contributed to serum dioxin levels. Exposures since 1980 in Midland and Saginaw counties contributed little to serum dioxins. Conclusions This study provides valuable insights into the relationships between serum dioxins and environmental factors, age, sex, body mass index, smoking, and breast-feeding. These factors together explain a substantial proportion of the variation in serum dioxin concentrations in the general population. Historic exposures to environmental contamination appeared to be of greater importance than recent exposures for dioxins. PMID:19479027

Garabrant, David H.; Franzblau, Alfred; Lepkowski, James; Gillespie, Brenda W.; Adriaens, Peter; Demond, Avery; Hedgeman, Elizabeth; Knutson, Kristine; Zwica, Lynn; Olson, Kristen; Towey, Timothy; Chen, Qixuan; Hong, Biling; Chang, Chiung-Wen; Lee, Shih-Yuan; Ward, Barbara; LaDronka, Kathy; Luksemburg, William; Maier, Martha

2009-01-01

394

Pregabalin serum levels in apprehended drivers.  

PubMed

Pregabalin is a medicinal drug used mainly for the treatment of epilepsy and neuropathic pain. It has been shown to possess an abuse potential and in recent years some reports of illegal use have been published. In order to further evaluate the extent and nature of pregabalin abuse, serum pregabalin levels of drivers apprehended for driving under the influence of drugs (DUID) in Finland in 2012 were assessed. The samples were analysed by an LC-MS/MS system and the results were evaluated in relation to the typical therapeutic range of pregabalin as well as the age and gender of the driver. Pregabalin was detected in 206 samples in the study period. The median (range) serum concentration was 6.2 (0.68-111.6)mg/L. In nearly 50% of the cases the serum concentration was above the typical therapeutic range. In most of the cases the driver had also taken other drugs besides pregabalin, the mean number of concomitantly taken drugs being four. Our data indicate that pregabalin is being used at high doses, probably for recreational purposes. The vast majority of the drivers positive for pregabalin in our study material had used pregabalin as a part of a spectrum of psycho-active drugs and thus qualified as probable drug abusers. In these cases pregabalin probably contributed to their driving impairment but to what extent remained unclear in this study. PMID:25072779

Kriikku, Pirkko; Wilhelm, Lars; Rintatalo, Janne; Hurme, Jukka; Kramer, Jan; Ojanperä, Ilkka

2014-10-01

395

Singlet oxygen quenching activity of human serum.  

PubMed

Singlet oxygen is regarded as contributing to the pathogenesis of various diseases including light-induced skin disorders and inflammatory response. In this study, the correlation between singlet oxygen quenching activity (SOQA) of human serum and blood biochemistry or life-style was evaluated. Healthy volunteers were recruited and carried out a measurement of SOQA by using electron paramagnetic resonance (EPR) and a questionnaire survey about a smoking. It was demonstrated that major quenchers of singlet oxygen in serum are proteins, and small molecular anti-oxidants relatively play a minor role. SOQA of whole sera showed no correlation with protein concentration, but positively correlated with SOQA of small molecular fraction. In vitro studies demonstrated that the decrease of sulfhydryl groups by NO or superoxide significantly attenuated SOQA of albumin. Together, these results may imply that the underlying oxidative condition in each individual influences both small molecular antioxidant states and the sulfhydryl content of serum proteins. SOQA of sera from women with a smoking history was significantly lower compared to non-smoking women, suggesting that the smoking habit impaired the defense mechanism against singlet oxygen. PMID:15720827

Kon, Tatsuya; Tanigawa, Toru; Hayamizu, Kohsuke; Shen, Manzhen; Tsuji, Tomoko; Naito, Yuji; Yoshikawa, Toshikazu

2004-01-01

396

Platelet lysate as replacement for fetal bovine serum in mesenchymal stromal cell cultures.  

PubMed

Mesenchymal stromal cells (MSC) emerged as highly attractive in cell-based regenerative medicine. Initially thought to provide cells capable of differentiation towards mesenchymal cell types (osteoblasts, chondrocytes, adipocytes etc.), by and by potent immunoregulatory and pro-regenerative activities have been discovered, broadening the field of potential applications from bone and cartilage regeneration to wound healing and treatment of autoimmune diseases. Due to the limited frequency in most tissue sources, ex vivo expansion of MSC is required compliant with good manufacturing practice (GMP) guidelines to yield clinically relevant cell doses. Though, still most manufacturing protocols use fetal bovine serum (FBS) as cell culture supplement to isolate and to expand MSC. However, the high lot-to-lot variability as well as risk of contamination and immunization call for xenogenic-free culture conditions. In terms of standardization, chemically defined media appear as the ultimate achievement. Since these media need to maintain all key cellular and therapy-relevant features of MSC, the development of chemically defined media is still - albeit highly investigated - only in its beginning. The current alternatives to FBS rely on human blood-derived components: plasma, serum, umbilical cord blood serum, and platelet derivatives like platelet lysate. Focusing on quality aspects, the latter will be addressed within this review. PMID:24273486

Bieback, Karen

2013-10-01

397

Concentrations and trends of perfluorinated chemicals in potential indoor sources from 2007 through 2011 in the US.  

PubMed

Certain perfluorinated chemicals (PFCs) in consumer products used indoors are potential indoor PFCs sources and have been associated with developmental toxicity and other adverse health effects in laboratory animals (Lao et al., 2007). The concentrations of selected PFCs including perfluorooctanoic acid (PFOA) and other perfluorocarboxylic acids (PFCAs), in 35 selected consumer products that are commonly used in indoors were measured from the year of 2007 through 2011. The products collected included carpet, commercial carpet-care liquids, household carpet/fabric-care liquids, treated apparel, treated home textiles, treated non-woven medical garments, floor waxes, food-contact paper, membranes for apparel, and thread-sealant tapes. They were purchased from retail outlets in the United States between March 2007 and September 2011. The perfluorocarboxylic acid (PFCA) contents in the products have shown an overall downward trend. However, PFOA (C8) could still be detected in many products that we analyzed. Reductions of PFCAs were shown in both short-chain PFCAs (sum of C4 to C7) and long-chain PFCAs (sum of C8 to C12) over the study period. There were no significant changes observed between short-chain PFCAs and long-chain PFCAs. Fourteen products were analyzed to determine the amounts of perfluoroalkyl sulfonates (PFASs) they contained. These limited data show the pronounced increase of perfluoro-butane sulfonate (PFBS), an alternative to perfluorooctanoic sulfonate (PFOS), in the samples. A longer and wider range of study will be required to confirm this observed trend. PMID:24268172

Liu, Xiaoyu; Guo, Zhishi; Krebs, Kenneth A; Pope, Robert H; Roache, Nancy F

2014-03-01

398

Chemical lasers  

NASA Astrophysics Data System (ADS)

The application and the advances of quantum electronics, specifically, of optical quantum generators lasers is reviewed. Materials are cut, their surfaces are machined, chemical transformations of substances are carried out, surgical operations are performed, data are transmitted, three dimensional images are produced and the content of microimpurities, in the atmosphere, are analyzed by use of a beam. Laser technology is used in conducting investigations in the most diverse fields of the natural and technical sciences from controlled thermonuclear fusion to genetics. Many demands are placed on lasers as sources of light energy. The importance of low weight, compactness of the optical generator and the efficiency of energy conversion processes is emphasized.

Khariton, Y.

1984-08-01

399

Chemical Separations  

NSDL National Science Digital Library

This site contains complete notes in a PowerPoint-like presentation for a chemical separations course. It covers a wide variety of topics, including distillation, extraction, gas chromatography, liquid chromatograpy, chromatography theory, instrumentation, electrophoresis, field flow fractionation, and affinity chromatography. It covers these topics thoroughly using a clear, consistent, and simple presentation style. Links to major topics like GC, LC, and electrophoresis provide specific information about the theory, instrumentation, and practice related to these techniques. The site also contains many annimations illustrating important separation processes.

2011-05-18

400

Drug and chemical metabolites in clinical toxicology investigations: The importance of ethylene glycol, methanol and cannabinoid metabolite analyses  

Microsoft Academic Search

Metabolic pathways in humans have been elucidated for most therapeutic drugs, drugs of abuse, and various chemical\\/solvents. In most drug overdose cases and chemical exposures, laboratory analysis is directed toward identification and quantitation of the unchanged drug or chemical in a biologic fluid such as serum or whole blood. Specifically, most clinical laboratories routinely screen and quantitate unchanged methanol and\\/or

Albert D Fraser; Lawrence Coffin; David Worth

2002-01-01

401

US Army Chemical Corps Vietnam veterans health study: preliminary results.  

PubMed

The long-term health consequences of exposure to phenoxyherbicides used in Vietnam has been a great concern to the veterans. In addition to the Air Force Ranch Hand personnel, Army Chemical Corps personnel who served in Vietnam are thought to have had some of the highest herbicide exposures. The Department of Veterans Affairs commenced a study of veterans who served in Vietnam as members of the Army Chemical Corps and a comparison cohort of Army Chemical Corps personnel who served elsewhere. A total of 2872 Vietnam veterans and 2737 non-Vietnam veterans who served in the Army Chemical Corps were identified for inclusion in a telephone health interview survey with a random 20% sample of veterans receiving serum dioxin and other congeners assessments. In a feasibility study which included 284 Vietnam veterans and 281 non-Vietnam veterans, 100 serum assessments were conducted of which 95 were included in the analysis. Vietnam veterans with a history of spraying herbicides were found to have a statistically significant elevation in their current serum 2,3,7,8-TCDD concentrations compared to non-Vietnam veterans without a spray history (P = 0.05). Other 2,3,7,8-substituted dioxins levels were comparable to the levels found in the non-Vietnam veterans. This feasibility study demonstrated that serum dioxin concentrations from a sample of the study participants can be used to identify exposure variables in the health survey that can serve as a surrogate measure of phenoxyherbicide exposure. PMID:11372888

Kang, H K; Dalager, N A; Needham, L L; Patterson, D G; Matanoski, G M; Kanchanaraksa, S; Lees, P S

2001-01-01

402

Hematology and serum chemistry of captive juvenile double-crested cormorants (Phalacrocorax auritus).  

PubMed Central

Hematologic and serum chemical values were obtained for double-crested cormorants (Phalacrocorax auritus) to improve clinical diagnosis of disease in this species. Blood samples were collected from 20 captive double-crested cormorants at 4 to 6 weeks of age. Hematocrit and leukocyte concentrations were determined in heparinized blood. Concentrations of sodium, potassium, chloride, bicarbonate, calcium, phosphorus, creatinine, glucose, uric acid, total protein, and albumin, and the activity levels of alkaline phosphatase, creatinine kinase, and aspartate aminotransferase were determined in serum. Total leukocyte concentrations in these double-crested cormorants were higher than the limited ranges reported for cormorants of other species, possibly due to subclinical infection with the liver trematode Amphimerus elongatus, and to differences in species and age. Images Figure 1. PMID:10416069

Kuiken, T; Danesik, K L

1999-01-01

403

Hematology and serum chemistry of captive juvenile double-crested cormorants (Phalacrocorax auritus).  

PubMed

Hematologic and serum chemical values were obtained for double-crested cormorants (Phalacrocorax auritus) to improve clinical diagnosis of disease in this species. Blood samples were collected from 20 captive double-crested cormorants at 4 to 6 weeks of age. Hematocrit and leukocyte concentrations were determined in heparinized blood. Concentrations of sodium, potassium, chloride, bicarbonate, calcium, phosphorus, creatinine, glucose, uric acid, total protein, and albumin, and the activity levels of alkaline phosphatase, creatinine kinase, and aspartate aminotransferase were determined in serum. Total leukocyte concentrations in these double-crested cormorants were higher than the limited ranges reported for cormorants of other species, possibly due to subclinical infection with the liver trematode Amphimerus elongatus, and to differences in species and age. PMID:10416069

Kuiken, T; Danesik, K L

1999-07-01

404

Stevioside enhances apoptosis induced by serum deprivation in PC12 cells.  

PubMed

In the laboratory, using a PC12 cell system, studies have been conducted on the effects of various chemicals on apoptosis, as it is considered to be an essential part of normal development, maintenance, and defense in organisms. Stevioside is a natural sweetener extracted from the leaves of Stevia rebaudiana. Since it is widely used as a sugar replacement, it was decided to evaluate the toxicological effects of low concentrations of stevioside on apoptosis induced by serum deprivation using the PC12 cell system. It was found that based on data from DNA electrophoresis and TUNEL signal assays stevioside enhanced apoptosis induced by serum deprivation. This enhancement was caused by increased expression of Bax and of cytochrome c released into the cytosol. These findings suggest that stevioside affects the regulation of the normal apoptotic condition. Further investigation will be needed to clarify the detailed mechanism of the enhancement due to the treatment with stevioside. PMID:22316388

Takahashi, Kumiko; Sun, Yongkun; Yanagiuchi, Ikumi; Hosokawa, Toshiyuki; Saito, Takeshi; Komori, Miyako; Okino, Tatsufumi; Kurasaki, Masaaki

2012-05-01

405

Molecularly imprinted poly(hydroxyethyl methacrylate) based cryogel for albumin depletion from human serum.  

PubMed

Macroporous cryogels imprinted with human serum albumin (HSA) have been prepared by copolymerization of 2-hydroxyethyl methacrylate with a functional co-monomer of N-methacryloyl-L-phenylalanine. The cryogels were used for the depletion of HSA from human serum. HSA-imprinted cryogels were prepared with gel fraction yields up to 90%, and their chemical structure, morphology and porosity were characterized by FTIR-spectroscopy, scanning electron microscopy, swelling studies and flow dynamics. Selective binding experiments were performed in the presence of competitive proteins like human transferrin and myoglobin. Albumin-imprinted cryogel column was optimized for fast protein liquid chromatography. Sodium-dodecyl sulfate polyacrylamide gel electrophoresis was used to show the efficiency of albumin depletion. PMID:23668981

Andac, Muge; Galaev, Igor Yu; Denizli, Adil

2013-09-01

406

Isolation of serum chylomicrons prior to density gradient ultracentrifugation of other serum lipoprotein classes.  

PubMed

A method for the removal of serum chylomicrons before density gradient ultracentrifugation of the other serum lipoproteins using an SW 41 swinging bucket rotor is presented. In a preliminary spin, the chylomicrons with an Sf greater than 400 X 10(-13) s float to the top of the gradient, whereas the other lipoproteins are retained in the infranatant fraction. After removal of the chylomicrons, the other serum lipoproteins are subsequently fractionated by isopycnic density gradient ultracentrifugation. Analysis of the separated lipoprotein fractions suggested that this procedure permits isolation of a chylomicron fraction consisting solely of chylomicrons but that the very low density lipoprotein fraction subsequently isolated also contains chylomicrons or chylomicron remnants with an Sf less than 400 X 10(-13) s, and that there is considerable overlap in flotation rate and particle size of very low density lipoproteins and chylomicrons. PMID:4083481

Terpstra, A H

1985-10-01

407

Quantitative liquid chromatographic determination of cefatrizine in serum and urine by fluorescence detection after post-column derivatization.  

PubMed

A fast, specific and sensitive high-performance liquid chromatographic procedure for the determination of cefatrizine, an orally active cephalosporin, in serum and urine is proposed. The drug is determined by the internal standard method, using cephradine as the internal standard. The separation is carried out on a reversed-phase column, filled with octadecylsilane chemically bonded microparticles. The eluent is a mixture of acetonitrile with 0.025 M sodium phosphate buffer (pH 7). Quantitation is effected by fluorescence detection of the fluorophores formed after post-column derivatization with fluorescamine in a packed-bed reactor. The chromatographic conditions and the conditions for the post-column derivatization are discussed. The method has been applied to serum and urine samples, which were analysed after deproteinization with trichloroacetic acid and injection of the clear supernatant. The accuracy and reproducibility of the procedure were investigated by the determination of the cefatrizine content in spiked serum and urine samples. PMID:528641

Crombez, E; Van der Weken, G; Van den Bossche, W; De Moerloose, P

1979-09-21

408

Chemical Analyses  

NASA Technical Reports Server (NTRS)

As a preliminary study on the effects of chemical aging of polymer materials MERL and TRI have examined two polymeric materials that are typically used for offshore umbilical applications. These two materials were Tefzel, a copolymer of ethylene and tetrafluoroethylene, and Coflon, polyvinylidene fluoride. The Coflon specimens were cut from pipe sections and exposed to H2S at various temperatures and pressures. One of these specimens was tested for methane permeation, and another for H2S permeation. The Tefzel specimens were cut from .05 mm sheet stock material and were exposed to methanol at elevated temperature and pressure. One of these specimens was exposed to methanol permeation for 2 days at 100 C and 2500 psi. An additional specimen was exposed to liquid methanol for 3 days at 150 C and 15 Bar. Virgin specimens of each material were similarly prepared and tested.

Bulluck, J. W.; Rushing, R. A.

1994-01-01

409

Serum Cystatin C as a Marker of Renal Function in Critically Ill Patients With Normal Serum Creatinine  

PubMed Central

Background: Serum creatinine as a classic marker of renal function has several limitations in the detection of renal dysfunction. Objectives: This study assessed the validity of serum cystatin C as a marker of renal function in critically ill patients with normal serum creatinine. Patients and Methods: Eighty adult patients referred to intensive care units with serum creatinine levels < 1.5 mg/dL and without hemodynamic instability were chosen and their serum creatinine and cystatin C levels were measured. A 24-hour urine sample was collected to calculate creatinine clearance (Ccr). Renal dysfunction was defined as Ccr < 80 mL/min/1.73 m2. Results: There were significant correlations between measured Ccr and 1/serum creatinine (R = 0.51, P < 0.001) and 1/serum cystatin C (R = 0.25, P = 0.028). The difference between false negative rates of serum creatinine (93.33%) and cystatin C (80%) in the detection of renal dysfunction was significant (P = 0.032). Receiver operating characteristic curve analysis illustrated that area under the curve of serum creatinine and cystatin C for detecting renal dysfunction were 0.711 and 0.607, respectively; however, this difference was not significant (P = 0.222). Conclusions: Our data demonstrated that serum cystatin C is not superior to serum creatinine in the early detection of renal dysfunction in critically ill patients. PMID:24783172

Sagheb, Mohammad Mahdi; Namazi, Soha; Geramizadeh, Bita; Karimzadeh, Amin; Oghazian, Mohammad Bagher; Karimzadeh, Iman

2014-01-01

410

Serum Concentrations of Polychlorinated Biphenyls in Relation to in Vitro Fertilization Outcomes  

PubMed Central

Background: Human exposure to polychlorinated biphenyls (PCBs) remains widespread. PCBs have been associated with adverse reproductive health outcomes including reduced fecundability and increased risk of pregnancy loss, although the human data remain largely inconclusive. Objective: Our goal was to explore the relationship between serum PCB concentrations and early pregnancy loss among a large cohort of women undergoing in vitro fertilization (IVF) between 1994 and 2003. Methods: Concentrations of 57 PCB congeners were measured in serum samples collected during 827 IVF/intracytoplasmic sperm injection cycles from 765 women. Joint statistical models that accommodate multiple outcomes and multiple cycles per woman were used to assess the relationship between serum PCB quartiles and implantation failure, chemical pregnancies (human chorionic gonadotropin level > 5.0 mIU/mL) that did not result in clinical pregnancy, or spontaneous abortion, while also adjusting for confounders. Results: PCB-153 was the congener present in the highest concentration (median, 46.2 ng/g lipid). Increasing quartiles of PCB-153 and the sum of all measured PCB congeners (?PCBs) were associated with significantly elevated dose-dependent odds of failed implantation. Adjusted odds ratios (95% confidence interval) for highest versus lowest quartile were 2.0 (1.2–3.4) for PCB-153 and 1.7 (1.0–2.9) for ?PCBs. There were suggestive trends for increased odds of implantation failure for PCB-118 and cytochrome P450–inducing congeners (p-values for trend = 0.06). No statistically significant associations between PCBs and chemical pregnancy or spontaneous abortion were found. Conclusions: Serum PCB concentrations at levels similar to the U.S. general population were associated with failed implantation among women undergoing IVF. These findings may help explain previous reports of reduced fecundability among women exposed to PCBs. PMID:21345762

Maity, Arnab; Missmer, Stacey A.; Williams, Paige L.; Mahalingaiah, Shruthi; Ehrlich, Shelley; Berry, Katharine F.; Altshul, Larisa; Perry, Melissa J.; Cramer, Daniel W.; Hauser, Russ

2011-01-01

411

Molecular Sex Differences in Human Serum  

PubMed Central

Background Sex is an important factor in the prevalence, incidence, progression, and response to treatment of many medical conditions, including autoimmune and cardiovascular diseases and psychiatric conditions. Identification of molecular differences between typical males and females can provide a valuable basis for exploring conditions differentially affected by sex. Methodology/Principal Findings Using multiplexed immunoassays, we analyzed 174 serum molecules in 9 independent cohorts of typical individuals, comprising 196 males and 196 females. Sex differences in analyte levels were quantified using a meta-analysis approach and put into biological context using k-means to generate clusters of analytes with distinct biological functions. Natural sex differences were established in these analyte groups and these were applied to illustrate sexually dimorphic analyte expression in a cohort of 22 males and 22 females with Asperger syndrome. Reproducible sex differences were found in the levels of 77 analytes in serum of typical controls, and these comprised clusters of molecules enriched with distinct biological functions. Analytes involved in fatty acid oxidation/hormone regulation, immune cell growth and activation, and cell death were found at higher levels in females, and analytes involved in immune cell chemotaxis and other indistinct functions were higher in males. Comparison of these naturally occurring sex differences against a cohort of people with Asperger syndrome indicated that a cluster of analytes that had functions related to fatty acid oxidation/hormone regulation was associated with sex and the occurrence of this condition. Conclusions/Significance Sex-specific molecular differences were detected in serum of typical controls and these were reproducible across independent cohorts. This study extends current knowledge of sex differences in biological functions involved in metabolism and immune function. Deviations from typical sex differences were found in a cluster of molecules in Asperger syndrome. These findings illustrate the importance of investigating the influence of sex on medical conditions. PMID:23251558

Ramsey, Jordan M.; Schwarz, Emanuel; Guest, Paul C.; van Beveren, Nico J. M.; Leweke, F. Markus; Rothermundt, Matthias; Bogerts, Bernhard; Steiner, Johann; Ruta, Liliana; Baron-Cohen, Simon; Bahn, Sabine

2012-01-01