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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.

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

2009-01-01

2

78 FR 62443 - Perfluoroalkyl Sulfonates and Long-Chain Perfluoroalkyl Carboxylate Chemical Substances; Final...  

Federal Register 2010, 2011, 2012, 2013

...Chemical Substances; Final Significant New Use Rule AGENCY: Environmental Protection...TSCA), EPA is amending a significant new use rule (SNUR) for perfluoroalkyl sulfonate...substances that have completed the TSCA new chemical review process, but have not...

2013-10-22

3

40 CFR 721.9573 - Substituted perfluoroalkyl sulfonamide (generic).  

Code of Federal Regulations, 2010 CFR

... false Substituted perfluoroalkyl sulfonamide (generic). 721.9573 Section...9573 Substituted perfluoroalkyl sulfonamide (generic). (a) Chemical substance...generically as a substituted perfluoroalkyl sulfonamide (PMN P-98-645) is subject...

2009-07-01

4

Toxicology of Perfluoroalkyl Acids*  

EPA Science Inventory

The perfluoroalkyl acids (PFAAs) are a family of organic chemicals consisting of a perfluorinated carbon backbone (4-12 in length) and an acidic functional moiety (carboxylate or sulfonate). These compounds are chemically stable, have excellent surface-tension reducing properties...

5

Toxicology of Perfluoroalkyl acids  

EPA Science Inventory

The Perfluoroalkyl acids(PFAAs) area a family of organic chemicals consisting of a perflurinated carbon backbone (4-12in length) and a acidic functional moiety (Carboxylate or sulfonate). These compounds have excellent surface-tension reducing properties and have numerous industr...

6

Impact of carbon chain length on binding of perfluoroalkyl acids to bovine serum albumin determined by spectroscopic methods.  

PubMed

Perfluoroalkyl acids (PFAAs), an emerging class of globally environmental contaminants, pose a great threat to humans with wide exposure from food and other potential sources. To evaluate the toxicity of PFAAs at the protein level, the effects of three PFAAs on bovine serum albumin (BSA) were characterized by fluorescence spectroscopy, synchronous fluorescence spectroscopy, and circular dichroism (CD). On the basis of the fluorescence spectra and CD data, we concluded that perfluoropentanoic acid (PFPA) had little effect on BSA. However, perfluorooctanoic acid (PFOA) and perfluorodecanoic acid (PFDA) exhibited remarkable fluorescence quenching, which was attributed to the formation of a moderately strong complex. The enthalpy change (DeltaH) and entropy change (DeltaS) indicated that van der Waals forces and hydrogen bonds were the dominant intermolecular forces in the binding of PFAAs to BSA. Furthermore, the BSA conformation was slightly altered in the presence of PFOA and PFDA, with a reduction of alpha helix. These results indicated that PFAAs indeed impact the conformation of BSA, and PFAAs with longer carbon chains were more toxic, especially at lower concentrations. PMID:20397730

Qin, Pengfei; Liu, Rutao; Pan, Xingren; Fang, Xiaoyan; Mou, Yue

2010-05-12

7

Perfluoroalkyl chemicals and human fetal development: An epidemiologic review with clinical and toxicological perspectives  

Microsoft Academic Search

Epidemiologists began to focus on human developmental outcomes with perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) as a consequence of dose-dependent developmental toxicological studies that reported effects of lowered birth weight, increased postnatal mortality, and decreased postnatal growth in surviving rats and mice. Contributing to the epidemiologic interest was the widespread presence of PFOS and PFOA in the general population, lengthy serum

Geary W. Olsen; John L. Butenhoff; Larry R. Zobel

2009-01-01

8

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 ...

9

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...

10

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...

11

TOXICOGENOMIC DISSECTION OF RODENT LIVER TRANSCRIPT PROFILES AFTER EXPOSURE TO PERFLUOROALKYL ACIDS  

EPA Science Inventory

Exposure to peroxisome proliferator chemicals (PPC) leads to alterations in the balance between hepatocyte growth and apoptosis, increases in liver to body weight ratios and liver tumors. The perfluoroalkyl acids including perfluorooctanoate (PFOA) and perfluorooctane sulfonate (...

12

Toxicogenomic study of triazole fungicides and perfluoroalkyl acids in rat livers predicts toxicity and categorizes chemicals based on mechanisms of toxicity.  

PubMed

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 perfluorinated chemicals [perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS)] were administered daily via oral gavage for one, three, or five consecutive days to male Sprague-Dawley rats at single doses of 300, 300, 175, 20, or 10 mg/kg/day, respectively. Clinical chemistry, hematology, and histopathology were measured at all time points. Gene expression profiling of livers from three rats per treatment group at all time points was performed on the CodeLink Uniset Rat I Expression array. Data were analyzed in the context of a large reference toxicogenomic database containing gene expression profiles for over 630 chemicals. Genomic signatures predicting hepatomegaly and hepatic injury preceded those results for all five chemicals, and further analysis segregated chemicals into two distinct classes. The triazoles caused similar gene expression changes as other azole antifungals, particularly the induction of pregnane X receptor (PXR)-regulated xenobiotic metabolism and oxidative stress genes. In contrast, PFOA and PFOS exhibited peroxisome proliferator-activated receptor alpha agonist-like effects on genes associated with fatty acid homeostasis. PFOA and PFOS also resulted in downregulation of cholesterol biosynthesis genes, matching an in vivo decrease in serum cholesterol, and perturbation of thyroid hormone metabolism genes matched by serum thyroid hormone depletion in vivo. The concordance of in vivo observations and gene expression findings demonstrated the ability of genomics to accurately categorize chemicals, identify toxic mechanisms of action, and predict subsequent pathological responses. PMID:17383973

Martin, Matthew T; Brennan, Richard J; Hu, Wenyue; Ayanoglu, Eser; Lau, Christopher; Ren, Hongzu; Wood, Carmen R; Corton, J Christopher; Kavlock, Robert J; Dix, David J

2007-03-22

13

Associations between perfluoroalkyl compounds and immune and clinical chemistry parameters in highly exposed bottlenose dolphins (Tursiops truncatus).  

PubMed

Perfluoroalkyl compounds (PFCs) are ubiquitous, persistent chemical contaminants found in the environment, wildlife, and humans. Despite the widespread occurrence of PFCs, little is known about the impact these contaminants have on the health of wildlife populations. The authors investigated the relationship between PFCs (including ?perfluorocarboxylates, ?perfluoroalkyl sulfonates, perfluorooctane sulfonate, perfluorooctanoic acid, and perfluorodecanoic acid) and the clinocopathologic and immune parameters in a highly exposed population (n?=?79) of Atlantic bottlenose dolphins (mean ?PFCs?=?1970?ng/ml; range 574-8670?ng/ml) sampled from 2003 to 2005 near Charleston, South Carolina, USA. Age-adjusted linear regression models showed statistically significant positive associations between exposure to one or more of the PFC totals and/or individual analytes and the following immunological parameters: absolute numbers of CD2+ T cells, CD4+ helper T cells, CD19+ immature B cells, CD21+ mature B cells, CD2/CD21 ratio, MHCII+ cells, B cell proliferation, serum IgG1, granulocytic, and monocytic phagocytosis. Several PFC analyte groups were also positively associated with serum alanine aminotransferase, gamma-glutamyltransferase, creatinine, phosphorus, amylase, and anion gap and negatively associated with cholesterol levels, creatinine phosphokinase, eosinophils, and monocytes. Based on these relationships, the authors suggest that the PFC concentrations found in Charleston dolphins may have effects on immune, hematopoietic, kidney, and liver function. The results contribute to the emerging data on PFC health effects in this first study to describe associations between PFCs and health parameters in dolphins. PMID:23322558

Fair, Patricia A; Romano, Tracy; Schaefer, Adam M; Reif, John S; Bossart, Gregory D; Houde, Magali; Muir, Derek; Adams, Jeff; Rice, Charles; Hulsey, Thomas C; Peden-Adams, Margie

2013-02-22

14

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.

2010-01-01

15

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.

Joensen, Ulla Nordstrom; Bossi, Rossana; Leffers, Henrik; Jensen, Allan Astrup; Skakkebaek, Niels E.; J?rgensen, Niels

2009-01-01

16

Toxicogenomic Study of Triazole Fungicides and Perfluoroalkyl Acids in Rat Livers Predicts Toxicity and Categorizes Chemicals Based on Mechanisms of Toxicity  

Microsoft Academic Search

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 triadime- fon) and two perfluorinated chemicals (perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS)) were administered daily via oral gavage for one, three, or five consecutive days to male Sprague-Dawley rats

Matthew T. Martin; Richard J. Brennan; Wenyue Hu; Eser Ayanoglu; Christopher Lau; Hongzu Ren; Carmen R. Wood; J. Christopher Corton; Robert J. Kavlock; David J. Dix

2007-01-01

17

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.

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

2009-01-01

18

Perfluoroalkyl and Polyfluoroalkyl Substances in the Environment: Terminology, Classification, and Origins  

PubMed Central

The primary aim of this article is to provide an overview of perfluoroalkyl and polyfluoroalkyl substances (PFASs) detected in the environment, wildlife, and humans, and recommend clear, specific, and descriptive terminology, names, and acronyms for PFASs. The overarching objective is to unify and harmonize communication on PFASs by offering terminology for use by the global scientific, regulatory, and industrial communities. A particular emphasis is placed on long-chain perfluoroalkyl acids, substances related to the long-chain perfluoroalkyl acids, and substances intended as alternatives to the use of the long-chain perfluoroalkyl acids or their precursors. First, we define PFASs, classify them into various families, and recommend a pragmatic set of common names and acronyms for both the families and their individual members. Terminology related to fluorinated polymers is an important aspect of our classification. Second, we provide a brief description of the 2 main production processes, electrochemical fluorination and telomerization, used for introducing perfluoroalkyl moieties into organic compounds, and we specify the types of byproducts (isomers and homologues) likely to arise in these processes. Third, we show how the principal families of PFASs are interrelated as industrial, environmental, or metabolic precursors or transformation products of one another. We pay particular attention to those PFASs that have the potential to be converted, by abiotic or biotic environmental processes or by human metabolism, into long-chain perfluoroalkyl carboxylic or sulfonic acids, which are currently the focus of regulatory action. The Supplemental Data lists 42 families and subfamilies of PFASs and 268 selected individual compounds, providing recommended names and acronyms, and structural formulas, as well as Chemical Abstracts Service registry numbers. Integr Environ Assess Manag 2011;7:513–541. © 2011 SETAC

Buck, Robert C; Franklin, James; Berger, Urs; Conder, Jason M; Cousins, Ian T; de Voogt, Pim; Jensen, Allan Astrup; Kannan, Kurunthachalam; Mabury, Scott A; van Leeuwen, Stefan PJ

2011-01-01

19

Perfluoroalkyl ketones: novel derivatization products for the sensitive determination of fatty acids by gas chromatography/mass spectrometry in electron impact and negative chemical ionization modes.  

PubMed

Analytically useful pentafluoro ketone derivatives of fatty acids are described. The gas chromatographic/mass spectrometric characteristics of these new derivatives are compared with those of methyl, trimethylsilyl and pentafluorobenzyl esters. Pentafluoro ketones exhibit excellent chromatographic properties and significantly shorter chromatographic retention times than these other esters. The electron impact mass spectra of these new compounds show informative acylium ions, whose intensity decreases with the degree of unsaturation of the parent fatty acid. The formation of strong and informative fragment ions in negative chemical ionization (CH(4)) mass spectra of pentafluoro ketone derivatives allows the detection and the characterization (length of the chain and number of double bonds) of fatty acids at trace levels (femtomole), even in the case of polyunsaturated compounds. The scope and limitations of this new derivatization technique are also discussed. PMID:10844732

Aubert, C; Rontani, J F

2000-01-01

20

Perfluoroalkylated compounds induce cell death and formation of reactive oxygen species in cultured cerebellar granule cells.  

PubMed

The present communication investigates the effects of different perfluoroalkylated compounds (PFCs) on formation of reactive oxygen species (ROS) and cell death in cultured cerebellar granule cells. This allows direct comparison with similar effects found for other environmental contaminants like polychlorinated biphenyls and brominated flame-retardants. The increase in ROS formation and cell death was assayed using the fluorescent probe 2,7-dichlorofluorescin diacetate (DCFH-DA) and the trypan blue exclusion assay. The effects of the PFCs were structure dependent. Cell death was induced at relatively low concentrations by perfluorooctyl sulfonate (PFOS), perfluorooctane sulfonylamide (PFOSA) and the fluorotelomer alcohol 1H, 1H, 2H, 2H-perfluorodecanol (FTOH 8:2) with EC(50)-values of 62 ± 7.6, 13 ± 1.8 and 15 ± 4.2 ?M (mean ± SD) respectively. PFOS, perfluorooctanoic acid (PFOA) and PFOSA induced a concentration dependent increase in ROS formation with EC(50)-values of 27 ± 9.0, 25 ± 11 and 57 ± 19?M respectively. Reduced cell viability and ROS formation were observed at concentration level close to what is found in serum of occupationally exposed workers. The effect of PFCs on ROS formation and cell viability was compared with other halogenated compounds and future investigations should emphasize effects of mixtures and how physical chemical properties of the compounds influence their toxicity. PMID:23340305

Reistad, Trine; Fonnum, Frode; Mariussen, Espen

2013-01-20

21

Cotton fabric modification for imparting high water and oil repellency using perfluoroalkyl phosphate acrylate via ?-ray-induced grafting  

Microsoft Academic Search

The perfluoroalkyl phosphate acrylates were grafted onto a cotton fabric via ?-ray irradiation to improve the hydrophobic and oleophobic properties. The change in chemical structure of grafted cotton fabric was detected by the Fourier transform infrared spectroscopy and the X-ray photoelectron spectroscopy. The contact angles for water and sunflower oil were determined to be over 150° and 140°, respectively, after

Hui Miao; Fenfen Bao; Liangliang Cheng; Wenfang Shi

2010-01-01

22

Cotton fabric modification for imparting high water and oil repellency using perfluoroalkyl phosphate acrylate via gamma-ray-induced grafting  

Microsoft Academic Search

The perfluoroalkyl phosphate acrylates were grafted onto a cotton fabric via gamma-ray irradiation to improve the hydrophobic and oleophobic properties. The change in chemical structure of grafted cotton fabric was detected by the Fourier transform infrared spectroscopy and the X-ray photoelectron spectroscopy. The contact angles for water and sunflower oil were determined to be over 150° and 140°, respectively, after

Hui Miao; Fenfen Bao; Liangliang Cheng; Wenfang Shi

2010-01-01

23

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

Long, Manhai; Bossi, Rossana; Bonefeld-J?rgensen, Eva C.

2012-01-01

24

Analytical chemistry of perfluoroalkylated substances  

Microsoft Academic Search

Polyfluorinated alkylated substances have recently gained scientific interest because they have been found to be present in appreciable concentrations in human serum, in surface waters, and in tissues of wildlife from remote areas. The developments in analytical chemistry of these mainly neutral or anionic surface-active compounds are reviewed in this paper. Problems associated with the determination of polyfluorinated alkylated compounds

Pim de Voogt; Mónica Sáez

2006-01-01

25

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...

26

Environmental and toxicity effects of perfluoroalkylated substances.  

PubMed

The production, use, environmental fate, occurrence, and toxicity of perfluoroalkylated substances have been reviewed. Although only a limited number of essential physicochemical data are available, thus hampering a complete assessment of the environmental fate of PFAS, it has become clear that PFAS behave differently from other nonpolar organic micropollutants. PFAS are present in environmental media in urbanized areas both with and without fluorochemicals production sites. The presence of PFOS at levels above the limit of detection has been demonstrated in almost all organisms sampled in a global survey as well as in both nonexposed and exposed human populations. The acute and chronic ecotoxicity of PFOS, PFOA, and 8:2 FTOH to aquatic organisms is moderate to low. Acute toxicity to rodents is also low. PFOS concentrations in effluents have been reported that approach indicative target values derived from available aquatic toxicity data. PFOA has been found to be weakly carcinogenic. This review shows the importance of the perfluoroalkylated substances for the environment and the necessity to fill the current gaps in knowledge of their environmental fate and effects. PMID:15366585

Hekster, Floris M; Laane, Remi W P M; de Voogt, Pim

2003-01-01

27

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

2012-06-22

28

Neonatal-maternal factors and perfluoroalkyl substances in cord blood.  

PubMed

Perfluoroalkyl substances (PFASs) can cross the placenta, enter fetal circulation, and were found to correlate with adverse fetal growth. However, determinants of cord blood PFASs are not fully characterized. The study aimed to explore the association between PFASs and neonatal-maternal factors within a Taiwanese birth cohort. We selected subjects from Taiwan Birth Panel Study, which enrolled 486 infant-mother pairs in 2004-2005. We collected cord blood and analyzed perfluorooctanoic acid (PFOA), perfluorooctanyl sulfonate (PFOS), perfluorononanoic acid (PFNA) and perfluoroundecanoic acid (PFUA) using a simple protein precipitation and an ultra-high performance liquid chromatography/tandem mass spectrometry. We retrieved information pertaining to maternal socio-demographics, lifestyle- and dietary-related factors through structured questionnaires during the postpartum hospital stay. A total of 439 subjects, with 90% response rate, have completed serum analysis and questionnaire survey. The median concentrations for PFOA, PFOS, PFNA, and PFUA in cord blood were 1.86, 5.67, 3.00, and 13.5ngmL(-1), respectively. After adjusting for potential confounders, multiple linear regression models revealed that log10-PFOA was positively associated with maternal age (?=0.011) and negatively associated with multiparity (?=-0.044). Log10-PFOS was negatively correlated with birth weight (?=-0.011) and higher maternal education (senior high school: ?=-0.067; university: ?=-0.088). Log10-PFUA tended to negatively associate with gender, male infants (?=-0.075), and using cosmetics during pregnancy (?=-0.065). Interestingly, presence of cockroaches in the home was positively associated with log10-PFOA (?=0.041) and 1og10-PFNA (?=0.123). In conclusion, this study demonstrated several factors to correlate with cord blood PFASs and further investigation are still needed for confirmation of exposure routes. PMID:23689097

Lien, Guang-Wen; Huang, Ching-Chun; Wu, Kuen-Yuh; Chen, Mei-Huei; Lin, Chien-Yu; Chen, Chia-Yang; Hsieh, Wu-Shiun; Chen, Pau-Chung

2013-05-18

29

Telomeric THAM-derived perfluoroalkylated surfactants for fluorocarbon emulsions.  

PubMed

New fluorophilic and hydrophilic, cost efficient telomeric surfactants derived from tris(hydroxymethyl)acrylaminomethane were synthesized in 2 steps in 80% yield with respect to the perfluoroalkylated telogen. They demonstrate better ability to emulsify fluorocarbons than Pluronic f-68. The biological tolerance of these new surfactants is remarkable, the perfluorohexyl derivative was tolerated at doses of 4g/kg bw after i.v. injection in mice. None of the perfluoroalkylated THAM derivatives induces hemolysis of human red blood cells at concentrations up to 200g/l in physiological solutions. PMID:1391520

Riess, J G; Pavia, A A; Pucci, B; Zarif, L

1992-01-01

30

Physical and chemical characterization of horse serum carboxylesterase  

SciTech Connect

The serine carboxylesterase from horse serum was characterized by amino acid composition, peptide mapping, molecular and subunit weights, C- and N-terminal amino acid sequencing, and partial sequencing of the amino acids around the essential serine residue at the active site. A protocol was developed for using reversed-phase high pressure liquid chromatography to obtain homogeneous preparation of horse serum carboxylesterase. In addition, a number of kinetic properties were determined, including the substrate specificity, effect of pH, and activation energies. The horse serum carboxylesterase was characterized by unusually low turnover numbers with substrates commonly used with serine carboxylesterases. A variety of criteria were used to confirm the low turnover numbers and the concomitant high concentration of the esterase in the serum. These included reversed-phase high pressure liquid chromatography, disc-gel electrophoresis, and labelling with (/sup 14/C) diisopropylphosphofluoridate.

Torres, J.L.

1987-01-01

31

Hematologic and serum chemical characteristics of mononuclear leukemia in Fischer 344 rats  

SciTech Connect

Hematologic, serum chemical, and histopathologic studies were performed on 17 aged Fischer 344 rats with mononuclear leukemia. Twelve of the rats had leukemic hemograms, while five had nonleukemic or marginally abnormal differential leukocyte counts. Hematologic findings revealed that all rats were profoundly anemic. Serum chemistry studies confirmed the occurrence of icterus observed clinically, a finding consistent with hemolytic anemia. Alanine aminotransferase and serum alkaline phosphatase values were elevated.

Kusewitt, D.F.; Hahn, F.F.; Pickrell, J.A.

1982-01-01

32

Promotion of Hepatocarcinogenesis by Perfluoroalkyl Acids in Rainbow Trout  

PubMed Central

Previously, we reported that perfluorooctanoic acid (PFOA) promotes liver cancer in a manner similar to that of 17?-estradiol (E2) in rainbow trout. Also, other perfluoroalkyl acids (PFAAs) are weakly estrogenic in trout and bind the trout liver estrogen receptor. The primary objective of this study was to determine whether multiple PFAAs enhance hepatic tumorigenesis in trout, an animal model that represents human insensitivity to peroxisome proliferation. A two-stage chemical carcinogenesis model was employed in trout to evaluate PFOA, perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluorooctane sulfonate (PFOS), and 8:2 fluorotelomer alcohol (8:2FtOH) as complete carcinogens or promoters of aflatoxin B1 (AFB1)- and/or N-methyl-N?-nitro-N-nitrosoguanidine (MNNG)-induced liver cancer. A custom trout DNA microarray was used to assess hepatic transcriptional response to these dietary treatments in comparison with E2 and the classic peroxisome proliferator, clofibrate (CLOF). Incidence, multiplicity, and size of liver tumors in trout fed diets containing E2, PFOA, PFNA, and PFDA were significantly higher compared with AFB1-initiated animals fed control diet, whereas PFOS caused a minor increase in liver tumor incidence. E2 and PFOA also enhanced MNNG-initiated hepatocarcinogenesis. Pearson correlation analyses, unsupervised hierarchical clustering, and principal components analyses showed that the hepatic gene expression profiles for E2 and PFOA, PFNA, PFDA, and PFOS were overall highly similar, though distinct patterns of gene expression were evident for each treatment, particularly for PFNA. Overall, these data suggest that multiple PFAAs can promote liver cancer and that the mechanism of promotion may be similar to that of E2.

Benninghoff, Abby D.; Orner, Gayle A.; Buchner, Clarissa H.; Hendricks, Jerry D.; Duffy, Aaron M.; Williams, David E.

2012-01-01

33

Perfluoroalkyl compounds in Danish wastewater treatment plants and aquatic environments  

Microsoft Academic Search

This study reports the results of a screening survey of perfluoroalkyl compounds (PFCs) in the Danish environment. The study included point sources (municipal and industrial wastewater treatment plants and landfill sites) and the marine and freshwater environments. Effluent and influent water and sewage sludge were analysed for point sources. Sediment, blue mussels (Mytilus edulis) and liver from plaice (Pleuronectes platessa),

R. Bossi; J. Strand; O. Sortkjær; M. M. Larsen

2008-01-01

34

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

35

77 FR 48924 - Perfluoroalkyl Sulfonates and Long-Chain Perfluoroalkyl Carboxylate Chemical Substances; Proposed...  

Federal Register 2010, 2011, 2012, 2013

...derivatives of PFOA and higher homologues or polymers that contain or may degrade to PFOA...functionalized molecules used to make polymers. World-wide production of fluorotelomer-based polymers (FTBP), was estimated at 20...

2012-08-15

36

Equine vitreous humor chemical concentrations: correlation with serum concentrations, and postmortem changes with time and temperature.  

PubMed Central

Samples of equine vitreous humor were analyzed for urea nitrogen, creatinine, sodium, chloride, phosphorus, calcium, potassium, and magnesium concentrations. Fresh vitreous chemical concentrations were compared to corresponding serum concentrations and expressed as a vitreous to serum ratio. The effects of postmortem time and temperature on the stability of the chemical concentrations were determined by incubation of the samples at 4 degrees C, and 20 degrees C and 37 degrees C for 6, 12, 24, or 48 h. Chemical concentrations were generally more stable at lower temperatures and shorter incubation times.

McLaughlin, B G; McLaughlin, P S

1988-01-01

37

Simultaneous determination of perfluoroalkyl phosphonates, carboxylates, and sulfonates in drinking water  

Microsoft Academic Search

A trace analytical method based on high performance liquid chromatography coupled to quadrupole time-of-flight high resolution mass spectrometry was developed for simultaneous determination of perfluoroalkyl phosphonates (PFPAs, carbon chain lengths C6,8,10), perfluoroalkyl carboxylates (PFCAs, C5–12), and perfluoroalkyl sulfonates (PFSAs, C4,6,8,10) in drinking water (tap water). Analytes were enriched on a mixed mode co-polymeric sorbent (C8+quaternary amine) using solid phase extraction.

Shahid Ullah; Tomas Alsberg; Urs Berger

2011-01-01

38

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

2013-05-24

39

Perfluoroalkylated surfactants: relationships between structure and acute toxicity in mice.  

PubMed

New single chain neutral, and single and double chain zwitterionic perfluoroalkylated surfactants or co-surfactants have been evaluated for in vivo applications. A study of the relationship between structure and acute toxicity in mice is presented. Acute toxicity evaluations i.v. in mice indicate the following trends (increasing tolerance): zwitterionic single-chain less than neutral single-chain less than zwitterionic double-chain and, where the polar head is concerned, single-chain compounds: phosphocholine less than phosphoramidate less than trehalose approximately sucrose less than maltose less than xylitol. PMID:1391421

Mahé, A M; Manoux, J; Valla, A; Follana, R; Zarif, L; Greiner, J; Vierling, P; Riess, J G

1992-01-01

40

The associations between serum perfluorinated chemicals and thyroid function in adolescents and young adults.  

PubMed

Perfluorinated chemicals (PFCs) have been widely used in a variety of products worldwide for years. However, the effect of PFCs on thyroid function has not yet been clearly defined. We recruited 567 subjects (aged 12-30 years) in a population-based cohort of adolescents and young adults with abnormal urinalysis in the childhood to determine the relationship between serum level of PFCs and the levels of serum free thyroxine (T4) and thyroid stimulating hormone (TSH). The geometric means and geometric standard deviation concentrations of perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), perfluorononanoic acid (PFNA) and perfluoroundecanoic acid (PFUA) were 2.67 (2.96) ng/ml, 7.78 (2.42) ng/ml, 1.01 (3.48) ng/ml and 5.81 (2.92) ng/ml, respectively. Differences in the levels of free T4 and TSH across different categories of PFOA, PFOS and PFUA were insignificant. After controlling for confounding factors, multiple linear regression analyses revealed mean serum level of free T4 increased significantly across categories (<60th, 60-89 and >90th percentiles) of PFNA (P for trend =0.012 in the full model). The association between PFNA and free T4 was more significant in male subjects in age group 20-30, active smokers and in those with higher body mass index in stratified analysis. Serum concentrations of PFNA were associated with serum free T4 levels in adolescents and young adults. PMID:23177245

Lin, Chien-Yu; Wen, Li-Li; Lin, Lian-Yu; Wen, Ting-Wen; Lien, Guang-Wen; Hsu, Sandy H J; Chien, Kuo-Liong; Liao, Chien-Chang; Sung, Fung-Chang; Chen, Pau-Chung; Su, Ta-Chen

2012-11-02

41

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

42

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

2013-04-16

43

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....

44

Perfluoroalkyl sulfonates and perfluorocarboxylates in two wastewater treatment facilities in Kentucky and Georgia  

Microsoft Academic Search

Discharge of effluents from municipal wastewater treatment plants (WWTPs) is a route for the introduction of certain organic contaminants into aquatic environments. Earlier studies have reported the occurrence of perfluorochemicals in effluents from WWTPs. In this study, contamination profiles of perfluorinated compounds (PFCs), including perfluoroalkyl sulfonates (PFASs; PFOS, PFOSA, PFHxS) and perfluoroalkyl carboxylates (PFACs; PFOA, PFNA, PFDA, PFDoDA, PFUnDA), were

Bommanna G. Loganathan; Kenneth S. Sajwan; Ewan Sinclair; Kurunthachalam Senthil Kumar; Kurunthachalam Kannan

2007-01-01

45

An Electrochemical Approach for the Synthesis of Perfluoroalkylated Purine and Indole Analogues of Plant Growth Regulators  

Microsoft Academic Search

In an effort to prepare new fluorine-containing molecules as analogues of Plant Growth Regulators (PGRs), the indirect electrochemical reduction, by means of an aromatic anion mediator, of perfluoroalkyl halides in the presence of purine and indolyl anions was carried out. The corresponding C-perfluoroalkylated products were obtained by an SRN1 mechanism, in moderate to good yields, and biological activity of some

Maurice Médebielle; Shozo Fujii; Katsuya Kato

2000-01-01

46

Synthesis and Properties of Perfluoroalkyl Groups Containing Double Four-Ring Spherosilicate (Siloxysilsesquioxane) Precursors  

Microsoft Academic Search

Organically modified cage-like double four-ring spherosilicates have received considerable interest in the construction of nanosized hybrid materials, as well as building units for structural well-defined polymers. This group is extended by perfluoroalkyl ligands containing spherosilicates, synthesized by addition reaction of the octahydridodimethylsiloxyoctasilsesquioxane [H(CH3)2Si]8Si8O20 and heptadecafluorodecyl methacrylate. The resultant liquid spherosilicate substituted with eight terminal perfluoroalkyl groups was characterized by 29Si

Dagobert Hoebbel; Christine Weber; Helmut Schmidt; Ralph-Peter Krüger

2002-01-01

47

Fast human serum profiling through chemical depletion coupled to gold-nanoparticle-assisted protein separation.  

PubMed

The use of chemical protein depletion in conjunction with gold-based nanoparticles for fast matrix assisted laser desoption ionization time of flight mass spectrometry-based human serum profiling was assessed. The following variables influencing the process were optimized: (i) amount of nanoparticles, (ii) sample pH, (iii) amount of protein and (iv) incubation time. pH was found the most important factor to be controlled, with an optimum range comprised between 5.8 and 6.4. The minimum incubation time to obtain an adequate profiling was 30 min. Using this approach, serum from five patients with lymphoma, five patients with myeloma and from two healthy volunteers were correctly classified using Principal component analysis. PMID:23141332

López-Cortés, Rubén; Oliveira, Elisabete; Núñez, Cristina; Lodeiro, Carlos; Páez de la Cadena, María; Fdez-Riverola, Florentino; López-Fernández, H; Reboiro-Jato, Miguel; Glez-Peña, Daniel; Luis Capelo, José; Santos, Hugo M

2012-08-23

48

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

2013-05-25

49

Laboratory studies on the fate of perfluoroalkyl carboxylates and sulfonates during snowmelt.  

PubMed

Perfluoroalkyl acids (PFAAs) are anthropogenic chemicals that occur in snow from both remote and source regions. Experiments were conducted to determine how PFAAs are released from a melting snowpack. Different PFAAs eluted from the snowpack at different times, those with short chains eluting early, those with long chains eluting late. The concentrations in the meltwater of PFAAs with medium chain lengths of 6 to 9 perfluorinated carbon atoms first increased and then decreased during the melt period. Such a peak elution had not been previously observed for any other chemicals. The specific snow surface area (SSA) influenced this elution type, with peak concentrations occurring earlier in a snowpack with lower SSA. Model simulations suggested that the snow surface decrease during the melt alone was insufficient to explain the observations. It was ruled out that the calcium concentration affected PFAA sorption to the snow surface in a similar way as sorption to sediments. Adsorption coefficients of PFAAs to the snow surface were estimated by fitting the measured and modeled elution profiles. PMID:21740009

Plassmann, Merle M; Meyer, Torsten; Lei, Ying Duan; Wania, Frank; McLachlan, Michael S; Berger, Urs

2011-07-25

50

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

51

Cotton fabric modification for imparting high water and oil repellency using perfluoroalkyl phosphate acrylate via ?-ray-induced grafting  

NASA Astrophysics Data System (ADS)

The perfluoroalkyl phosphate acrylates were grafted onto a cotton fabric via ?-ray irradiation to improve the hydrophobic and oleophobic properties. The change in chemical structure of grafted cotton fabric was detected by the Fourier transform infrared spectroscopy and the X-ray photoelectron spectroscopy. The contact angles for water and sunflower oil were determined to be over 150° and 140°, respectively, after irradiated with a dose range of 471-5664 Gy. The flame retardancy of the fabric with a grafting ratio of over 13.0 wt% was improved, reaching to 24 compared with 18 of which before grafted, according to the limiting oxygen index measurement. The microstructure of the fabric before and after grafted was observed by the scanning electron microscope.

Miao, Hui; Bao, Fenfen; Cheng, Liangliang; Shi, Wenfang

2010-07-01

52

Survival, morphology and adhesion properties of cerebellar interneurones cultured in chemically defined and serum-supplemented medium.  

PubMed

Cultures obtained from early postnatal rat cerebellum, grown in either chemically defined or in serum-supplemented medium containing 25 mM K+, contained predominantly (greater than 90%) small interneurones, mostly granule cells, with good and comparable viability (assessed by the retention of preloaded 51Cr). Neuronal survival was prolonged in the chemically defined medium, nerve cells living up to two weeks longer than in serum-supplemented medium, although the proportion of non-neuronal cells was not greatly increased. In the serum-supplemented medium neurones became organised into clumps connected by thick, fasciculated bundles of neurites by about one week in vitro. In comparison, in the chemically defined medium aggregation of neurones and fasciculation of neurites was markedly reduced even after 4 weeks in culture. The possible relationship between the organisation of neurones and the nature of the substratum, chemical factors in the medium as well as the surface properties of the cells is discussed. PMID:3986585

Kingsbury, A E; Gallo, V; Woodhams, P L; Balazs, R

1985-01-01

53

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

54

Analysis of perfluoroalkyl substances in waters from Germany and Spain.  

PubMed

Water has been identified as one of the main routes of human exposure to perfluoroalkyl substances (PFASs). This work assessed the presence of 21 PFASs along the whole water cycle using a new fast and cost effective analytical method based on an online sample enrichment followed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The method was validated for different types of matrices (ultrapure water, tap water and treated wastewater). The quality parameters for the 21 selected compounds presented good limits of detection (LOD) and quantification (LOQ) ranging, in general, from 0.83-10 ng/L to 2.8-50 ng/L, respectively. The method was applied to assess the occurrence of PFASs in 148 water samples of different steps along the whole water cycle, including: mineral bottled water, tap water, river water and treated effluent wastewater, from Germany to Spain. In addition, in order to prove the good performance of the online analytical method, the analysis of PFASs was carried out in parallel using a method based on offline anionic solid phase extraction (SPE) followed by LC-MS/MS. Consistent results were obtained using both approaches. The more frequently found compounds were perfluoroalkyl acids, such as the perfluorobutanoic acid which was in the 54% of the tap water samples investigated with concentrations in the range between 2.4 and 27 ng/L, the perfluoroheptanoic acid (0.23-53 ng/L) and perfluorooctanoic acid (0.16-35 ng/L), and the sulphonate perfluorooctanesulfonate (0.04-258 ng/L) which was the second more frequent compound and also the compound found in with the higher concentration. It should be remarked that the 88% of the samples analyzed presented at least one of the compounds at quantifiable concentrations. In addition, PFASs including short chain compounds were proved to be prevalent in drinking water, and the 50% of the drinking water samples showed quantifiable concentrations of PFASs. It should be said that the great majority of the samples may not pose an immediate health risk to consumers, and just 6 of the drinking water samples presented concentrations of PFOS exceeding the Provisional Health Advisory (PHA) level established by the Office of Water from the USEPA for PFOS, which was set in 200 ng/L. PMID:22683491

Llorca, Marta; Farré, Marinella; Picó, Yolanda; Müller, Jutta; Knepper, Thomas P; Barceló, Damià

2012-06-07

55

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

56

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

Microsoft Academic Search

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,

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

2009-01-01

57

Perfluoroalkyl chains direct novel self-assembly of insulin.  

PubMed

The self-assembly of biopharmaceutical peptides into multimeric, nanoscale objects, as well as their disassembly to monomers, is central for their mode of action. Here, we describe a bioorthogonal strategy, using a non-native recognition principle, for control of protein self-assembly based on intermolecular fluorous interactions and demonstrate it for the small protein insulin. Perfluorinated alkyl chains of varying length were attached to desB30 human insulin by acylation of the ?-amine of the side-chain of LysB29. The insulin analogues were formulated with Zn(II) and phenol to form hexamers. The self-segregation of fluorous groups directed the insulin hexamers to self-assemble. The structures of the systems were investigated by circular dichroism (CD) spectroscopy and synchrotron small-angle X-ray scattering. Also, the binding affinity to the insulin receptor was measured. Interestingly, varying the length of the perfluoroalkyl chain provided three different scenarios for self-assembly; the short chains hardly affected the native hexameric structure, the medium-length chains induced fractal-like structures with the insulin hexamer as the fundamental building block, while the longest chains lead to the formation of structures with local cylindrical geometry. This hierarchical self-assembly system, which combines Zn(II) mediated hexamer formation with fluorous interactions, is a promising tool to control the formation of high molecular weight complexes of insulin and potentially other proteins. PMID:22129241

Malik, Leila; Nygaard, Jesper; Hoiberg-Nielsen, Rasmus; Arleth, Lise; Hoeg-Jensen, Thomas; Jensen, Knud J

2011-12-22

58

Retinyl. beta. -glucoronide: its occurrence in human serum, chemical synthesis and biological activity  

SciTech Connect

When retinol is administered to rats, retinyl and retinoyl ..beta..-glucuronides appear in the bile. Retinyl or retinoyl ..beta..-glucuronide is also synthesized in vitro when rat liver microsomes are incubated with uridinediphosphoglucuronic acid and either retinol or retinoic acid. Retinoyl ..beta..-glucuronide, a major metabolite of retinoic acid in a number of tissues, is highly active biologically, has been chemically synthesized, and is found in human blood. The physiological significance of the glucuronides of vitamin A are not known yet. To investigate further its metabolism and possible physiological role, retinyl ..beta..-glucuronide was chemically synthesized from retinol and characterized by study of its ultra-violet spectrum (..gamma../sub max/ 325 nm in methanol, 329 nm in water), /sup 1/H-NMR and mass spectra. Retinyl ..beta..-glucuronide was extensively hydrolyzed by bacterial ..beta..-glucuronidase to retinol. Retinyl ..beta..-glucuronide is soluble in water and was detected in significant amounts in the serum of healthy human adults. The biological activity of synthetic retinyl ..beta..-glucuronide was determined in rats by the rat growth bioassay method.

Barua, A.B.; Batres, R.O.; Olson, J.A.

1986-01-01

59

Do Human Milk Concentrations of Persistent Organic Chemicals Really Decline During Lactation? Chemical Concentrations During Lactation and Milk/Serum Partitioning  

PubMed Central

Background Conventional wisdom regarding exposures to persistent organic chemicals via breast-feeding assumes that concentrations decline over the course of lactation and that the mother’s body burden reflects her cumulative lifetime exposure. Two important implications stemming from these lines of thought are, first, that assessments of early childhood exposures should incorporate decreasing breast milk concentrations over lactation; and, second, that there is little a breast-feeding mother can do to reduce her infant’s exposures via breast-feeding because of the cumulative nature of these chemicals. Objectives We examined rates of elimination and milk/serum partition coefficients for several groups of persistent organic chemicals. Methods We collected simultaneous milk and blood samples of 10 women at two times postpartum and additional milk samples without matching blood samples. Results Contrary to earlier research, we found that lipid-adjusted concentrations of polybrominated diphenyl ethers, polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins and furans, and organochlorine pesticides in serum and milk do not consistently decrease during lactation and can increase for some women. Published research has also suggested an approximate 1:1 milk/serum relationship (lipid adjusted) on a population basis for 2,3,7,8-tetrachlorodibenzo-p-dioxin; however, our results suggest a more complex relationship for persistent, lipophilic chemicals with the milk/serum relationship dependent on chemical class. Conclusions Decreases in concentration of lipophilic chemicals on a lipid-adjusted basis during lactation should no longer be assumed. Thus, the concept of pumping and discarding early milk as means of reducing infant exposure is not supported. The hypothesis that persistent lipophilic chemicals, on a lipid-adjusted basis, have consistent concentrations across matrices is likely too simplistic.

LaKind, Judy S.; Berlin, Cheston M.; Sjodin, Andreas; Turner, Wayman; Wang, Richard Y.; Needham, Larry L.; Paul, Ian M.; Stokes, Jennifer L.; Naiman, Daniel Q.; Patterson, Donald G.

2009-01-01

60

Validation of a prediction model for estimating serum concentrations of chemicals which are equivalent to toxic concentrations in vitro.  

PubMed

The objective of the present study was to evaluate the validity of a recently developed extrapolation model for the prediction of concentrations of chemicals in serum which are equivalent to in vitro effective nominal concentrations. Necessary input data are in vitro toxic concentrations and distribution relevant system and substance specific parameters, e.g. lipid volume fractions and albumin concentrations, octanol/water partition coefficients and specific binding to albumin. It was investigated whether the influence of human and bovine serum, respectively, on nominal cytotoxic potencies (EC(50)-values) of selected chemicals in vitro can be properly predicted using this algorithm. Cytotoxicity was determined as growth inhibition of proliferating Balb/c 3T3 cells after exposure for 72 h. Concentration-effect relationships were measured in the presence of 2% foetal bovine serum (FBS) and, additionally, 18% FBS or human serum (HS), or 1% (w/v) bovine (BSA) or human (HSA) albumin, respectively. Addition of HSA and BSA increased the EC(50)-values of the different chemicals by factors of 2.1 - 22 and 1.7 - 29, respectively. From these measurements values for the specific binding of the test compounds to BSA and HSA were derived. Addition of 18% HS increased the EC(50)-values by factors between 4.2 and 52, while addition of 18% FBS resulted only in 1.5 - 10.4-fold increases. A comparison of experimentally determined and calculated EC(50)-values revealed that the differing influence of human and bovine serum was quite well predicted by the extrapolation model. Deviations did not exceed the factor 3 and were in most cases lower than 2. It is concluded that the extrapolation model is quite well suited to predict equivalent concentrations in serum from in vitro effective concentrations. PMID:16580813

Gülden, Michael; Dierickx, Paul; Seibert, Hasso

2006-03-06

61

Capturing labile sulfenamide and sulfinamide serum albumin adducts of carcinogenic arylamines by chemical oxidation.  

PubMed

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 Cys(34) 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

2012-12-28

62

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...

63

Electron transfer in reactions of tert-perfluoroalkyl bromides with alkenes and nucleophiles  

Microsoft Academic Search

Tertiary perfluoroalkyl bromides (RFBr) in nonpolar solvents under mild conditions can be added to the multiple bond of terminal alkenes, alkynes, and butadiene. Slow addition to alkenes at 20°C is accelerated in proton-donating solvents and is catalyzed by readily oxidizable nucleophiles. Bromination of the multiple bond and formation of RFBr reduction products suggests a radicalchain mechanism initiated by electron transfer

I. N. Rozhkov; I. V. Chaplina

1991-01-01

64

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...

65

Perfluoroalkyl and polyfluoralkyl substances (PFASs) in the environment: terminology, classification, and origins  

Microsoft Academic Search

The primary aim of this article is to provide an overview of perfluoroalkyl and polyfluoroalkyl substances (PFASs) detected in the environment, wildlife, and humans, and recommend clear, specific, and descriptive terminology, names, and acronyms for PFASs. The overarching objective is to unify and harmonize communication on PFASs by offering terminology for use by the global scientific, regulatory, and industrial communities.

R. C. Buck; J. Franklin; U. Berger; J. M. Conder; I. T. Cousins; Voogt de P; A. A. Jensen; K. Kannan; S. A. Mabury; Leeuwen van S. P. J

2011-01-01

66

Complete amino acid sequencing and immunoaffinity clean-up can facilitate screening of various chemical modifications on human serum albumin.  

PubMed

This manuscript describes a simple and practical strategy for screening of various chemical modifications of human serum albumin (HSA). Serum albumin is the most abundant blood plasma protein in humans (HSA, 66.5 kDa, t1/2?=?19 d), constituting about 60 % of total proteins. Therefore, it is believed to be the main target of chemical stresses during physiological events such as increased oxidative stress from the degenerative diseases of aging, and higher glucose stress in diabetes mellitus. Consequently, chemical modifications can provide significant information about these biological events. In this study, a complete and robust sequencing method was attained by the peptide mass fingerprinting (PMF) technique using two different complementary proteases (trypsin and Glu-C) and matrix-assisted laser desorption ionization-time of flight/mass spectrometry (MALDI-TOF/MS) in both positive and negative ionization modes. Using this strategy, several modified peptides, 12 oxidations, 25 glycations, 6 lipoxidations, and 5 nitrations have been identified on HSA treated with chemical reactions in vitro. Combined with immunoaffinity clean-up, this method was able to detect in vivo chemical modifications of HSA and found oxidized Trp(214) and glycated Lys(525) in healthy human plasma. PMID:23846590

Goto, Takaaki; Murata, Kazuyuki; Lee, Seon Hwa; Oe, Tomoyuki

2013-07-12

67

Bioaccumulation of perfluoroalkyl carboxylates (PFCAs) and perfluoroalkane sulfonates (PFSAs) by earthworms (Eisenia fetida) in soil.  

PubMed

Earthworms were exposed to artificially contaminated soils with ten perfluoroalkyl substances (PFASs). PFASs with longer perfluorinated carbon chain displayed higher uptake rate coefficients (k(u)), longer half-life (t(½)) and time to steady-state (t(ss)) but lower elimination rate coefficients (k(e)) than the shorter ones. Similarly, perfluorosulfonates acids (PFSAs) displayed higher ku, longer t(½) and tss but lower ke than perflurocarboxylic acids (PFCAs) with the same perfluorinated chain length. All the studied PFASs, including those with seven or less perfluorinated carbons, were bioaccumulated in the earthworms and the biota-to-soil accumulation factors (BSAFs) increased with perfluorinated carbon chain length and were greater for PFSAs than for PFCAs of equal perfluoroalkyl chain length. The BSAFs were found to be dependent on the concentrations of PFASs in soil and decreased as the level of PFASs in soil increased. PMID:23644275

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

2013-05-03

68

Synergistic stabilization of perfluorocarbon-pluronic F-68 emulsion by perfluoroalkylated polyhydroxylated surfactants  

Microsoft Academic Search

One of the most serious limitations of the first generation of fluorocarbon emulsions destined to serve as injectable oxygen\\u000a carriers (blood substitutes) is their insufficient, stability. Considerable stabilization of such emulsions has now been achieved\\u000a by using a combination of Pluronic F-68, a polyoxyethylene polyoxypropylene block polymer, and of a perfluoroalkylated polyhydroxylated\\u000a surfactant (PPFS) comprising a C6F13 or C8F17 fluorophilic

Leila Zarif; Alexandre Manfredi; Christian Varescon; Maurice Le Blanc; Jean G. Riess

1989-01-01

69

African yam bean hull chemical composition and its effects on rat's mineral retention, serum biochemical components and enzymatic activities.  

PubMed

The influence of yam bean hull on rat's mineral metabolism, serum composition and enzymatic activities was investigated. The chemical composition of the bean's hull shows a reasonably high crude protein (11.4%) but very low contents of crude fat (2.6%), phytic acid (82 mg/100 g) and phytin-phosphorus (23 mg/100 g). K and Ca are the major minerals present in yam bean hull. The hull, rich in cell wall polysaccharides, is composed of cellulose (35.4%), non-cellulose fractions made of pectin and hemicellulose put together (41.9%) and lignin (3.6%). The growth and feed conversion efficiency of rats fed yam bean hull diet were significantly better than rats fed pure cellulose and cellulose-free diets. Conversely, the metabolizable energy of yam bean hull diet (16.4 MJ/kg) was significantly (p < 0.05) lower than that of either cellulose-free (17.8 MJ/kg) or pure cellulose diet (17 MJ/kg). The retention of the minerals examined, except for Ca, was lower when the hull was included in diet as compared to the control (fibre-free) diet. The fibre containing diets decreased serum cholesterol, glutamic oxaloacetate transaminase (SGOT) and glutamic pyruvate transaminase (SGPT). Yam bean hull had no effect on packed cell volume and serum total protein. PMID:9631372

Agunbiade, S O; Longe, O G

1998-04-01

70

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

71

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.

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

72

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 (...

73

Oxidative conversion as a means of detecting precursors to perfluoroalkyl acids in urban runoff.  

PubMed

A new method was developed to quantify concentrations of difficult-to-measure and unidentified precursors of perfluoroalkyl carboxylic (PFCA) and sulfonic (PFSA) acids in urban runoff. Samples were exposed to hydroxyl radicals generated by thermolysis of persulfate under basic pH conditions and perfluoroalkyl acid (PFAA) precursors were transformed to PFCAs of related perfluorinated chain length. By comparing PFCA concentrations before and after oxidation, the concentrations of total PFAA precursors were inferred. Analysis of 33 urban runoff samples collected from locations around the San Francisco Bay, CA indicated that PFOS (2.6-26 ng/L), PFOA (2.1-16 ng/L), and PFHxA (0.9-9.7 ng/L) were the predominant perfluorinated compounds detected prior to sample treatment. Following oxidative treatment, the total concentrations of PFCAs with 5-12 membered perfluoroalkyl chains increased by a median of 69%, or between 2.8 and 56 ng/L. Precursors that produced PFHxA and PFPeA upon oxidation were more prevalent in runoff samples than those that produced PFOA, despite lower concentrations of their corresponding perfluorinated acids prior to oxidation. Direct measurements of several common precursors to PFOS and PFOA (e.g., perfluorooctanesulfonamide and 8:2 fluorotelomer sulfonate) accounted for less than 25% of the observed increase in PFOA, which increased by a median value of 37%. Exposure of urban runoff to sunlight, advanced oxidation processes, or microbes could result in modest, but measurable, increases in concentrations of PFCAs and PFSAs. PMID:22900587

Houtz, Erika F; Sedlak, David L

2012-08-17

74

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.

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

2011-01-01

75

In situ fate and partitioning of waterborne perfluoroalkyl acids (PFAAs) in the Youngsan and Nakdong River Estuaries of South Korea.  

PubMed

Concentrations, distributions, fate, and partitioning of perfluoroalkyl acids (PFAAs) were investigated in surface water (n=34) collected from the Youngsan and Nakdong River Estuaries of South Korea. Thirteen individual PFAAs in water and suspended solids (SS) were quantified by use of HPLC-MS/MS. PFAAs were detected in all samples, which indicated that they were widely distributed in the study area. Greater concentrations of PFAAs were found at some inland sites which seemed to be affected by direct input from point sources, such as wastewater treatment plants, and/or indirect diffusive sources, such as surface runoff. Spatial distributions of PFAAs in estuaries along transects toward the open sea demonstrated that these chemicals were transported to the outer region primarily by water discharged during the rainy season. Field-based partition coefficients (K(d)) for long-chain PFAAs (C?8) were significantly correlated with salinity (r(2)=0.48 to 0.73, p<0.01); K(d) values increased exponentially as a function of salinity. Due to the 'salting-out' effect, PFAAs were largely scavenged by adsorption onto SS and/or sediments in estuarine environments. In addition, values for K(d) of those PFAAs were directly proportional to the number of carbon atoms in the PFAAs. Salting constants of selected PFAAs were notably greater than those of other environmental organic contaminants, which indicated that adsorption of PFAAs is largely associated with salinity. Overall, the results of the present study will provide better understanding of the fate and transport of PFAAs in the zone of salinity boundary that can be used for developing fate models of PFAAs in the coastal marine environment. PMID:23333509

Hong, Seongjin; Khim, Jong Seong; Park, Jinsoon; Kim, Minhee; Kim, Woong-Ki; Jung, Jinho; Hyun, Seunghun; Kim, Jeong-Gyu; Lee, Hyojin; Choi, Heeseon J; Codling, Garry; Giesy, John P

2013-01-16

76

Determining a Robust D-Optimal Design for Testing for Departure from Additivity in a Mixture of Four Perfluoroalkyl Acids.  

EPA Science Inventory

Our objective is to determine an optimal experimental design for a mixture of perfluoroalkyl acids (PFAAs) that is robust to the assumption of additivity. PFAAs are widely used in consumer products and industrial applications. The presence and persistence of PFAAs, especially in ...

77

Land use and the spatial distribution of perfluoroalkyl compounds as measured in the plasma of bottlenose dolphins ( Tursiops truncatus)  

Microsoft Academic Search

The distribution of perfluoroalkyl compounds (PFCs) in the environment is well documented with higher concentrations observed in wildlife located in industrial and urban areas. This study examined the distribution of PFCs in relation to land use using blood samples collected from bottlenose dolphins during capture-release health assessment surveys conducted in Charleston, SC. The study area was partitioned into three subareas

Jeffrey Adams; Magali Houde; Derek Muir; Todd Speakman; Gregory Bossart; Patricia Fair

2008-01-01

78

Synthesis of perfluoroalkylated xylitol ethers and esters: new surfactants for biomedical uses.  

PubMed

New, well-defined surfactants and cosurfactants were synthesized with the objective of enhancing the stability of fluorocarbon emulsions destined to serve as oxygen carriers for biomedical applications. Monoperfluoroalkylated ethers of xylitol were achieved by addition of perfluoroalkyl iodide on the double bond of a protected xylitol allyl ether in a one-step addition-elimination reaction. Monoesters were obtained specifically on position 5 by treating 1,2:3,4-di-O-isopropylidenexylitol with perfluoroalkylated acid chlorides of various chain lengths in pyridine at room temperature. The products display strong surface activity and produce a remarkable synergistic stabilization of a fluorocarbon/Pluronic F-68 type emulsion. Biocompatibility data are reported, which include in vitro toxicity tests on Namalva cell cultures and hemolysis tests on human blood cells; the latter was found to decrease as the length of the F-alkyl chain increased. IV injection in mice (n = 10) showed that these products were innocuous at 400-1000 mg/kg of body weight. Preliminary exchange-perfusion experiments on rats with an emulsion containing the F-octyl xylitol ether were encouraging. PMID:2319569

Zarif, L; Greiner, J; Pace, S; Riess, J G

1990-04-01

79

Tissue-specific concentrations and patterns of perfluoroalkyl carboxylates and sulfonates in East Greenland polar bears.  

PubMed

Several perfluoroalkyl carboxylates (PFCAs) and perfluoroalkyl sulfonates (PFSAs) of varying chain length are bioaccumulative in biota. However, wildlife reports have focused on liver and with very little examination of other tissues, and thus there is a limited understanding of their distribution and potential effects in the mammalian body. In the present study, the comparative accumulation of C(6) to C(15) PFCAs, C(4), C(6), C(8) and C(10) PFSAs, and select precursors were examined in the liver, blood, muscle, adipose, and brain of 20 polar bears (Ursus maritimus) from Scoresby Sound, Central East Greenland. Overall, PFSA and PFCA concentrations were highest in liver followed by blood > brain > muscle ? adipose. Liver and blood samples contained proportionally more of the shorter/medium chain length (C(6) to C(11)) PFCAs, whereas adipose and brain samples were dominated by longer chain (C(13) to C(15)) PFCAs. PFCAs with lower lipophilicities accumulated more in the liver, whereas the brain accumulated PFCAs with higher lipophilicities. The concentration ratios (±SE) between perfluorooctane sulfonate and its precursor perfluorooctane sulfonamide varied among tissues from 9 (±1):1 (muscle) to 36 (±7):1 (liver). PFCA and PFSA patterns in polar bears indicate that the pharmacokinetics of these compounds are to some extent tissue-specific, and are the result of several factors that may include differing protein interactions throughout the body. PMID:23057644

Greaves, Alana K; Letcher, Robert J; Sonne, Christian; Dietz, Rune; Born, Erik W

2012-10-23

80

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

81

Simultaneous determination of perfluoroalkyl phosphonates, carboxylates, and sulfonates in drinking water.  

PubMed

A trace analytical method based on high performance liquid chromatography coupled to quadrupole time-of-flight high resolution mass spectrometry was developed for simultaneous determination of perfluoroalkyl phosphonates (PFPAs, carbon chain lengths C6,8,10), perfluoroalkyl carboxylates (PFCAs, C5-12), and perfluoroalkyl sulfonates (PFSAs, C4,6,8,10) in drinking water (tap water). Analytes were enriched on a mixed mode co-polymeric sorbent (C8+quaternary amine) using solid phase extraction. Chromatographic separation was achieved on a Zorbax Extend C18 reversed phase column using a mobile phase gradient consisting of water, methanol, and acetonitrile containing 2mM ammonium acetate and 5 mM 1-methyl piperidine. The mass spectrometer was operated in electrospray negative ion mode. Use of 1-methyl piperidine in the mobile phase resulted in a significant increase in instrument sensitivity for PFPAs through improved chromatographic resolution, background suppression, and increased ionization efficiency. Method detection limits for extraction of 500 mL tap water were in the ranges of 0.095-0.17 ng/L, 0.027-0.17 ng/L, and 0.014-0.052 ng/L for PFPAs, PFCAs, and PFSAs, respectively. Whole method recoveries at a spiking level of 0.5 ng/L to 500 mL HPLC grade water were 40-56%, 56-97%, and 55-77% for PFPAs, PFCAs, and PFSAs, respectively. A matrix effect (signal enhancement) was observed in the detection of PFPAs in tap water extracts, leading to calculated recoveries of 249-297% at a 0.5 ng/L spiking level. This effect resulted in an additional improvement of method sensitivity for PFPAs. To compensate for the matrix effect, PFPAs in tap water were quantified using matrix-matched and extracted calibration standards. The method was successfully applied to the analysis of drinking water collected from six European countries. PFPAs were not detected except for perfluorooctyl phosphonate (PFOPA) at close to the detection limit of 0.095 ng/L in two water samples from Amsterdam, the Netherlands. Highest levels were found for perfluorobutane sulfonate (PFBS, 18.8 ng/L) and perfluorooctanoate (PFOA, 8.6 ng/L) in samples from Amsterdam as well as for perfluorooctane sulfonate (PFOS, 8.8 ng/L) in tap water from Stockholm, Sweden. PMID:21791340

Ullah, Shahid; Alsberg, Tomas; Berger, Urs

2011-07-08

82

Serum low density lipoprotein of alcoholic patients is chemically modified in vivo and induces apolipoprotein E synthesis by macrophages.  

PubMed Central

This work was carried out to investigate the effect of alcohol drinking on serum LDL. Agarose gel electrophoresis showed that LDL samples from alcoholic patients without serious liver disease were more negatively charged and moved faster toward the cathode than LDL from nondrinking control subjects. Rabbit antibodies raised by using keyhole limpet hemocyanin modified in vitro by 4-hydroxynonenal or by acetaldehyde as immunogens reacted more strongly with patients' LDL than with control LDL, indicating the presence of oxidatively modified epitopes and acetaldehyde adducts in alcoholic patients' LDL. LDL of alcoholic patients has decreased vitamin E contents. The electromobility of LDL decreased after abstinence from alcohol and returned to normal in 2 wk, but this was not accompanied by a significant increase in its vitamin E contents. When incubated with mouse peritoneal macrophages, patients' LDL induced apolipoprotein E secretion by threefold over control LDL with a concomitant increase in cellular cholesterol. Our results thus demonstrate that LDL of alcoholic patients has lower vitamin E content, is chemically modified in vivo, and exhibits altered biological function. These changes in heavy alcoholic drinkers may render LDL more atherogenic and thereby may counter the antiatherosclerosis effects of moderate alcohol consumption. Images

Lin, R C; Dai, J; Lumeng, L; Zhang, M Y

1995-01-01

83

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.

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

2010-01-01

84

Spontaneous three-dimensional nanostructure formation of perfluoroalkyl terminated liquid crystal: A molecular dynamics simulation study  

NASA Astrophysics Data System (ADS)

Structure formation of a perfluoroalkyl terminated liquid crystal molecule was studied by molecular dynamics simulations. Two distinct structures with smectic-C-like layers and with bundles (blocks) of collapsed layers were spontaneously formed depending on the simulation temperatures. The bundles in the latter structure were somewhat positionally ordered (with respect to the small angle spots in its structure function) and orientationally isotropic overall even though the molecules making each bundle were well oriented. These characteristics of the simulated system well correspond to the cubic phase of the real system, and an even more precisely correspond to the proposed cubic structure model [M. Yoneya, E. Nishikawa, and H. Yokoyama, J. Chem. Phys. 120, 3699 (2004)] with respect to its hierarchical structure.

Yoneya, Makoto; Nishikawa, Etsushi; Yokoyama, Hiroshi

2004-10-01

85

Rate constants for hydrogen abstraction from alkoxides by a perfluoroalkyl radical. An oxyanion accelerated process.  

PubMed

A combination of laser flash photolysis and competitive kinetic methods has been used to measure the absolute bimolecular rate constants for hydrogen atom abstraction in water from a series of fluorinated alkoxides and aldehyde hydrates by the perfluoroalkyl radical, *CF2CF2OCF2CF2SO3- Na+. The bimolecular rate constants observed for the beta-fluorinated alkoxides were in the 10(5) M(-1) s(-1) range, such rates representing enhancements (relative to the respective alcohols) of between 100 and almost 1000-fold, depending on the reactivity of the alkoxide. Likewise, the monobasic sodium salts of chloral and fluoral hydrate exhibit similar rate enhancements, relative to their respective hydrates. PMID:15254636

Cradlebaugh, Joseph A; Zhang, Li; Shelton, G Robert; Litwinienko, Grzegorz; Smart, Bruce E; Ingold, Keith U; Dolbier, William R

2004-06-24

86

Occurrence of perfluoroalkyl substances in fish and water from the Svitava and Svratka rivers, Czech Republic.  

PubMed

Perfluoroalkyl substances (PFHxS, FHUEA, PFOA, PFOS, FOSA, N-methyl FOSA and PFNA) from seven sites on the Svitava and Svratka rivers in the Brno conurbation (Czech Republic) were determined in fish blood plasma and water. Concentrations of PFHxS, FHUEA, FOSA, and N-methyl FOSA were below detection limits. Major compound in fish blood was PFOS (38.9-57.8 ng mL(-1)), followed by PFNA and PFOA. In water, the major compound detected was PFOA (1.7-178.0 ng mL(-1)), followed by PFOS and PFNA. A significant (p < 0.05) correlation for PFOA concentration in blood plasma and water was found (r = 0.74). PMID:22147082

Kovarova, Jana; Marsalek, Petr; Blahova, Jana; Jurcikova, Jana; Kasikova, Barbora; Svobodova, Zdenka

2011-12-07

87

Design, synthesis and evaluation of fluorocarbons and surfactants for in vivo applications. New perfluoroalkylated polyhydroxylated surfactants.  

PubMed

The progress achieved since the advent of Fluosol-DA is summarized in this paper, with special focus on the synthesis and evaluation of more adequate, reliable, industrially feasible fluorocarbons, structure/property relationships--molecular weight being recognized as the pre-eminent determining factor of both the fluorocarbon's excretion rate and the emulsion's stability-, the preparation of significantly more concentrated, more efficacious emulsions, etc. The key to further progress and better mastery of the emulsions' characteristics, especially in relation to increased shelf-life, prolonged i.v. persistence, and versatility, now lies in the development of new surfactants, better adapted to this objective. New families of well defined, monodisperse perfluoroalkylated polyhydroxylated surfactants derived from sugars and related compounds have been synthesized and fully characterized. Preliminary evaluation of their surface-active properties, emulsion stabilizing capacity and biocompatibility are reported. PMID:3052646

Riess, J G; Arlen, C; Greiner, J; Le Blanc, M; Manfredi, A; Pace, S; Varescon, C; Zarif, L

1988-01-01

88

Interactions of DPPC with semitelechelic poly(glycerol methacrylate)s with perfluoroalkyl end groups.  

PubMed

Semitelechelic poly(glycerol methacrylate)s having a perfluoroalkyl end group (PGMA(n)-F(9)) were synthesized by ATRP. The interactions of these polymers with different degrees of polymerization with chiral or racemic dipalmitoylphosphatidylcholine (l-DPPC, d-DPPC, or rac-DPPC) monolayers at the air/water interface were studied. Langmuir trough measurements coupled with epifluorescence microscopy allowed for the observation of domain formation within the coexistence region of liquid-expanded (LE) and liquid-condensed (LC) states of DPPC in mixed DPPC-polymer films prepared by spreading a solution of both compounds in the same organic solvent (cospread films). Because of the incorporation of PGMA(n)-F(9) polymers into the LE phase and their line-active behavior, a formation of novel types of domains could be observed. During compression, a thinning out of the tips of two- to six-lobed flowerlike domain structures and consecutive spiral formation appeared for l- and d-DPPC within the two-phase coexistence region (LE/LC) of the monolayer. When rac-DPPC was used, symmetrical stripe formation was induced at the vertices of the domains and fingerprint-like structures were created by convection-inducing movements of the domains at the air/water interface. Additional investigations of the interaction of PGMA(n)-F(9) with DPPC vesicles using differential scanning calorimetry (DSC) supported the finding on the monolayer system that the incorporation of the polymers into the lipid monolayers is not solely driven by the perfluoroalkyl chain but significantly by the hydrophilic polymer part. Apparently, interactions of the PGMA chain with the lipid headgroups are important as the interactions increase with the elongation of the polymer chain, indicating that the polymer also has hydrophobic character. PMID:23046205

Scholtysek, Peggy; Li, Zheng; Kressler, Jörg; Blume, Alfred

2012-10-18

89

Perfluoroalkylated telomers derived from tris(hydroxymethyl)acrylamidomethane as surfactants and co-surfactants in fluorocarbon emulsions  

Microsoft Academic Search

The ability of perfluoroalkylated telomers derived from tris(hydroxymethyl)acrylamidomethane (TAC) to stabilize fluorocarbon emulsions has been investigated. For this purpose, 50% w\\/v emulsions of perfluorodecalin (FDC) and perfluoro-octyl bromide (PFOB) were prepared with a total 3% w\\/v of surfactant and were compared with emulsions prepared with Pluronic F-68® or egg yolk phospholipids (EYP). When used as the sole surfactant, telomers 1

Evelyne Myrtil; Leila Zarif; Jacques Greiner; Jean G. Riess; Bernard Pucci; André A. Pavia

1995-01-01

90

Brain region distribution and patterns of bioaccumulative perfluoroalkyl carboxylates and sulfonates in east greenland polar bears (Ursus maritimus).  

PubMed

The present study investigated the comparative accumulation of perfluoroalkyl acids (PFAAs) in eight brain regions of polar bears (Ursus maritimus, n?=?19) collected in 2006 from Scoresby Sound, East Greenland. The PFAAs studied were perfluoroalkyl carboxylates (PFCAs, C(6) -C(15) chain lengths) and sulfonates (C(4) , C(6) , C(8) , and C(10) chain lengths) as well as selected precursors including perfluorooctane sulfonamide. On a wet-weight basis, blood-brain barrier transport of PFAAs occurred for all brain regions, although inner regions of the brain closer to incoming blood flow (pons/medulla, thalamus, and hypothalamus) contained consistently higher PFAA concentrations compared to outer brain regions (cerebellum, striatum, and frontal, occipital, and temporal cortices). For pons/medulla, thalamus, and hypothalamus, the most concentrated PFAAs were perfluorooctane sulfonate (PFOS), ranging from 47 to 58?ng/g wet weight, and perfluorotridecanoic acid, ranging from 43 to 49?ng/g wet weight. However, PFOS and the longer-chain PFCAs (C(10) -C(15) ) were significantly (p??0.05) different among brain regions. The burden of the sum of PFCAs, perfluoroalkyl sulfonates, and perfluorooctane sulfonamide in the brain (average mass, 392?g) was estimated to be 46?µg. The present study demonstrates that both PFCAs and perfluoroalkyl sulfonates cross the blood-brain barrier in polar bears and that wet-weight concentrations are brain region-specific. PMID:23280712

Greaves, Alana K; Letcher, Robert J; Sonne, Christian; Dietz, Rune

2013-03-01

91

Influence Of Magnetic Iron Oxide Nanoparticles And Perfluoroalkylated Amphiphilic Phosphates On Red Blood Cells And Caco-2 Cells  

Microsoft Academic Search

The interactions of two types of cells (red blood cells (RBCs), Caco-2 cells) with magnetic iron oxide nanoparticles (non-grafted, citrate-grafted, dendrimer-grafted) of 11 nm in size, and with three perfluoroalkylated amphiphilic phosphates varying in chain length and number of fluorine atoms have been investigated. We focused on two important physiological parameters of the cells, the intracellular pH and the intracellular

Daniel Moersdorf; Pierre Hugounenq; Lai Truonc Phuoc; Hind Mamlouk-Chaouachi; Gergana Nikolova; Marie Pierre Krafft; Gilles Waton; Delphine Felder-Flesch; Sylvie Begin-Colin; Geneviève Pourroy; Ingolf Bernhardt

2010-01-01

92

Polyfluoroalkyl phosphate esters and perfluoroalkyl carboxylic acids in target food samples and packaging-method development and screening.  

PubMed

Polyfluoroalkyl phosphate mono-, di-, and tri-esters (mono-, di-, and triPAPs) are used to water- and grease-proof food packaging materials, and these chemicals are known precursors to perfluoroalkyl carboxylic acids (PFCAs). Existing analytical methods for PAPs lack sample clean-up steps in the sample preparation. In the present study, a method based on ultra performance liquid chromatography coupled to tandem mass spectrometry (UPLC/MS/MS) was developed and optimized for the analysis of mono-, di-, and triPAPs, including a clean-up step for the raw extracts. The method was applied to food samples and their PAP-containing packaging materials. The optimized UPLC/MS/MS method enabled the separation and identification of a total of 4 monoPAPs, 16 diPAPs, and 7 triPAPs in the technical mixture Zonyl®-RP. For sample clean-up, weak anion exchange solid phase extraction columns were tested. PAPs standard solutions spiked onto the columns were separated into a fraction containing neutral compounds (triPAPs) and a fraction with ionic compounds (mono- and diPAPs) with recoveries between 72-110 %. Method limits of quantification for food samples were in the sub to low picogram per gram range. For quantitative analysis of PAPs, compound-specific labeled internal standards showed to be essential as sorption and matrix effects were observed. Mono-, di-, and/or triPAPs were detected in all food packaging materials obtained from the Swedish market. Up to nine diPAPs were detected in the food samples, with the 6:2/6:2 and 6:2/8:2 diPAPs as the dominant compounds. DiPAP concentrations in the food samples ranged from 0.9 to 36 pg/g, which was comparable to individual PFCA concentrations in the same samples. Consumption of food packed in PAP-containing materials could be an indirect source of human exposure to PFCAs. PMID:23494682

Gebbink, Wouter A; Ullah, Shahid; Sandblom, Oskar; Berger, Urs

2013-03-15

93

Self-assembled organic monolayers terminated in perfluoroalkyl pentafluoro-lambda(6)-sulfanyl (-SF5) chemistry on gold.  

PubMed

Recently synthesized (Winter, R.; Nixon, P. G.; Gard, G. L.; Radford, D. H.; Holcomb, N. R.; Grainger, D. W. J. Fluorine Chem. 2001, 107, 23-30) SF5-terminated perfluoroalkyl thiols (SF5(CF2)nCH2CH2SH, where n = 2, 4, and 6) and a symmetric SF5-terminated dialkyl disulfide ([SF5-CH=CH-(CH2)8-S-]2) were assembled as thin films chemisorbed onto gold surfaces. The adsorbed monolayer films of these SF5-containing molecules on polycrystalline gold were compared using ellipsometry, contact angle, X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS), and infrared spectroscopy (FTIR) surface analytical methods. The resulting SF5-dialkyl disulfide monolayer film shows moderate angle dependence in depth-dependent XPS analysis, suggesting a preferentially oriented film. The SF5-terminated perfluoroalkyl thiols exhibit angular-dependent XPS compositional variance depending on perfluoroalkyl chain length, consistent with improved film assembly (increasingly hydrophobic, fewer defects, and more vertical chain orientation increasing film thickness) with increasing chain length. Tof-SIMS measurements indicate that both full parent ions for these film-forming molecules and the unique SF5 terminal group are readily detectable from the thin films without substantial contamination from other adsorbates. PMID:16459592

Winter, R; Nixon, P G; Gard, G L; Graham, D J; Castner, D G; Holcomb, N R; Grainger, D W

2004-07-01

94

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

95

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.

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

2007-01-01

96

Bioaccumulation of perfluoroalkyl acids in dairy cows in a naturally contaminated environment.  

PubMed

Beef and dairy products may be important vectors of human exposure to perfluoroalkyl acids (PFAAs), but the understanding of how PFAAs are accumulated and transferred through agricultural food chains is very limited. Here, the bioaccumulation of PFAAs in dairy cows receiving naturally contaminated feed and drinking water was investigated by conducting a mass balance of PFAAs for a herd of dairy cows in a barn on a typical Swedish dairy farm. It was assumed that the cows were able to reach steady state with their dietary intake of PFAAs. Perfluorooctane sulfonic acid (PFOS) and perfluoroalkyl carboxylic acids (PFCAs) with 8 to 12 carbons were detected in cow tissue samples (liver, muscle, and blood) at concentrations up to 130 ng kg(-1). Mass balance calculations demonstrated an agreement between total intake and excretion within a factor of 1.5 and consumption of silage was identified as the dominant intake pathway for all PFAAs. Biomagnification factors (BMFs) were highly tissue and homologue specific. While BMFs of PFOS and PFCAs with 9 and 10 fluorinated carbons in liver ranged from 10 to 20, perfluorooctanoic acid (PFOA) was not biomagnified (BMF?

Vestergren, Robin; Orata, Francis; Berger, Urs; Cousins, Ian T

2013-05-01

97

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

98

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

2012-03-21

99

Spatial distribution of perfluoroalkyl acids in the Pearl River of Southern China.  

PubMed

An intensive campaign was conducted in September 2012 to collect surface water samples along the tributaries of the Pearl River in southern China. Thirteen perfluoroalkyl acids (PFAAs), including perfluorocarboxylates (PFCAs, C4-C11) and perfluorosulfonates (PFSAs, C4, C6-C8, and C10), were determined using high-performance liquid chromatography/negative electrospray ionization-tandem mass spectrometry (HPLC/(-)ESI-MS/MS). The concentrations of total PFAAs (?PFAAs) ranged from 3.0 to 52ngL(-1), with an average of 19±12ngL(-1). The highest concentrations of ?PFAAs were detected in the surface water of the Dong Jiang tributary (17-52ngL(-1)), followed by the main stream (13-26ngL(-1)) and the Sha Wan stream (3.0-4.5ngL(-1)). Perfluorooctanoate (PFOA), perfluorobutane sulfonate (PFBS), and perfluorooctane sulfonate (PFOS) were the three most abundant PFAAs and on average accounted for 20%, 24%, and 19% of ?PFAAs, respectively. PFBS was the most abundant PFAA in the Dong Jiang tributary, and PFOA was the highest PFAA in the samples from the main stream of the Pearl River. A correlation was found between PFBS and PFOA, which suggests that both of these PFAAs originate from common source(s) in the region. Nevertheless, the slope of PFBS/PFOA was different in the different tributaries sampled, which indicates a spatial difference in the source profiles of the PFAAs. PMID:23973287

Zhang, Yingyi; Lai, Senchao; Zhao, Zhen; Liu, Fobang; Chen, Hongwei; Zou, Shichun; Xie, Zhiyong; Ebinghaus, Ralf

2013-08-22

100

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

2013-07-31

101

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

102

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

2013-03-29

103

Acids and alkali resistant sticky superhydrophobic surfaces by one-pot electropolymerization of perfluoroalkyl alkyl pyrrole.  

PubMed

Over the past few years, electropolymerization of semifluorinated monomers like thiophene or pyrrole has been used as a gentle and effective method to generate, in one step, stable superhydrophobic surfaces. The synthetic route mostly involves the coupling reaction between a carboxylic acid and an alcohol, using a carboxy group-activated reagent and a catalyst. As a consequence, the electroformed surfaces present high liquid repellency due to the concomitant effect of roughness and low surface energy. Nevertheless, the ester connector can be cleaved under acidic and basic conditions, preventing its use under a range of environmental conditions. To overcome this drawback, a new perfluoroalkyl alkyl pyrrole has been synthesized, the fluorinated segment being connected to the electropolymerizable part via an alkyl chain, and electropolymerized, leading to surfaces that exhibit a static contact angle with water superior to 150 degrees and no sliding angle, over a wide pH range and with a long lifetime. This represents the first example of a pure conducting polymer surface with sticky superhydrophobicity not only in pure water but also in corrosive solutions such as acids and bases, giving rise to new prospects in practical applications. PMID:20060984

Nicolas, Mael

2009-11-26

104

Determination of MK-287, a new platelet-activating factor antagonist, in plasma and serum by gas chromatography chemical ionization mass spectrometry.  

PubMed

MK-287 is a novel platelet-activating factor antagonist. A sensitive and specific gas chromatographic/mass spectrometric assay has been developed for the determination of the drug in serum and plasma. The assay utilizes an extraction with methyl-t-butyl ether and subsequent trimethylsilylation of the hydroxyl function. The gas chromatographic/mass spectrometric determinations are carried out with temperature-programmed capillary gas chromatography and ammonia negative chemical ionization mass spectrometry. The method has sufficient sensitivity, precision, accuracy and selectivity for the analysis of drug concentrations in clinical samples. PMID:1932155

Fisher, A L; Morris, M J; Gilbert, J D

1991-07-01

105

The measurement of iron-binding capacity in serum and purified transferrin with the aid of chemical affinity chromatography.  

PubMed Central

In a mew method for the estimation of transferrin by iron-binding capacity iron is added as the tartrate in NaCl with about 10 mM bicarbonate. The excess iron is removed by passage through DEAE-Sephadex A-50 previously treated with the iron chelator disodium catechol-3,5-disulphonate. The iron remaining bound to transferrin is measured without protein precipitation by the use of ferrozine. The method is applicable to fresh, frozen, or lyophilized serum, purified transferrin, and some quality control preparations. Validation experiments confirm that transferrin in serum and in pure solution is saturated with iron and give some evidence of specificity. The possible use of commercially available transferrin preparations as analytical reference standards is discussed.

Ramsay, W N

1975-01-01

106

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

107

Association between serum perfluorinated chemicals and thyroid function in u.s. Adults: the national health and nutrition examination survey 2007-2010.  

PubMed

Context: Perfluorinated chemicals (PFCs) have been widely used in a variety of products worldwide for years. The relationship between serum PFCs and thyroid function has never been addressed in a nationally representative survey. Objectives: The study examined the association between serum PFCs and thyroid function in the general U.S. population. Design and Participants: We selected 1181 subjects (aged >20 years) from a National Health and Nutrition Examination Survey (NHANES) in 2007 through 2008 and 2009 through 2010 to determine the relationship between serum PFCs and thyroid function. Data were adjusted for confounding variables. Results: The geometric means and 95% confidence interval (CI) concentrations of perfluorooctanoate (PFOA), perfluorooctane sulfonate, perfluorononanoic acid, and perfluorohexane sulfonate (PFHxS) were 4.15 (4.02-4.29), 14.2 (13.59-14.86), 1.54 (1.48-1.59), and 2.00 (1.89-2.11) ng/mL, respectively. After weighting for sampling strategy, we determined a 1-U increase in natural log-serum PFOA increased serum total T3 concentration by 6.628 ng/dL (95% CI = 0.545-12.712, P = .035) in women. A 1-U increase in natural log-PFHxS was associated with an increase of total T4 by 0.26 ?g/mL (95% CI = 0.108-0.413, P = .002) and total T3 by 4.074 ng/dL (95% CI = 2.232-5.916, P < .001) in women and a decrease of natural log-free T4 by 0.016 (ng/dL) (95% CI = -0.029 to 0.003, P = .019) in men. Conclusion: Higher serum concentrations of PFOA and PFHxS are associated with total T3, total T4, and free T4 in the U.S. general population. More studies are warranted to clarify the causal relationship between PFCs and thyroid function. PMID:23864701

Wen, Li-Li; Lin, Lian-Yu; Su, Ta-Chen; Chen, Pau-Chung; Lin, Chien-Yu

2013-07-17

108

Perfluoroalkyl contaminants in window film: indoor/outdoor, urban/rural, and winter/summer contamination and assessment of carpet as a possible source.  

PubMed

Window film concentrations of ionic perfluoroalkyl contaminants (PFCs) were determined indoors and outdoors at urban, suburban, and rural sites in or near Toronto, Ontario, Canada, to identify locations of relatively elevated concentrations and the nature of potential sources. The role of carpet installation and floor wax application as possible sources was also evaluated by sampling indoor window films at five sites before and after new carpet installations, at one site before and after a floor wax application, and at two carpet stores. Low concentrations were found in all outdoor window films, with comparable relative proportions of individual PFCs among sites, suggesting similar sources to the outdoor environment and rapid air mixing. PFCs in indoor window film were up to 20-fold greater than outdoor, providing some evidence that a significant proportion of PFCs originate from the indoor environment, although precipitation wash-off of outdoor window film may be confounding these results. For both indoor and outdoor film, PFC concentrations generally changed between the summer and winter but the chemical profiles were similar between seasons. Concentrations of PFCs in window films increased one month post carpet installation at three of the five sites, suggesting that some of the carpets may have been a source to the indoor environment. Indoor window films from two carpet stores (sigmaPFC = 16 and 7 pg/cm2) contained higher concentrations than the other indoor locations (sigmaPFC = < MDL to 4.3 pg/cm2), which may reflect the carpets stored within these buildings. The use of window film allowed collection of a wide range of samples and the results can be used to focus the efforts of more traditional air sampling campaigns. PMID:19848140

Gewurtz, Sarah B; Bhavsar, Satyendra P; Crozier, Patrick W; Diamond, Miriam L; Helm, Paul A; Marvin, Chris H; Reiner, Eric J

2009-10-01

109

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

2013-09-09

110

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

2013-09-18

111

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

112

Dietary exposure to perfluoroalkyl acids for the Swedish population in 1999, 2005 and 2010.  

PubMed

Dietary intake has been hypothesized to be the major pathway of human exposure to perfluoroalkyl acids (PFAAs). However, difficulties associated with the analysis of PFAAs at ultra trace levels in food samples have prevented the confirmation of this hypothesis. In this study, the dietary intake of PFAAs for the general Swedish population was estimated by applying a highly sensitive analytical method to a set of archived food market basket samples from 1999, 2005 and 2010. Dietary exposure to perfluorooctane sulfonic acid (PFOS) (860-1440 pg kg?¹ day?¹), perfluoroundecanoic acid (PFUnDA) (90-210 pg kg?¹ day?¹), perfluorodecanoic acid (PFDA) (50-110 pg kg?¹ day?¹) and perfluorononanoic acid (PFNA) (70-80 pg kg?¹ day?¹) was dominated by the consumption of fish and meat. In contrast, dietary exposure to PFOA (350-690 pg kg?¹ day?¹) originated from low levels (8-62 pg g?¹) found in several high consumption food categories including cereals, dairy products, vegetables and fruit. The dietary intakes of PFOS and PFOA estimated in this study were 4 to 10 times lower compared to previous exposure modeling studies. Nevertheless, the dietary intake of PFOS and PFOA was still a factor of 6 to 10 higher than exposure through ingestion of household dust and drinking water estimated for the general Swedish population. For perfluorohexanoic acid (PFHxA), perfluoroheptanoic acid (PFHpA) and perfluorohexane sulfonic acid (PFHxS) drinking water intake was the major exposure pathway (36-53% of the total exposure) whereas dust ingestion made a significant contribution (27-49%) to the total exposure for PFHxA, PFHpA, PFNA, perfluorotridecanoic acid (PFTrDA) and perfluorotetradecanoic acid (PFTeDA). Dietary intakes varied by less than a factor of three for all PFAAs during the different sampling years which demonstrates that dietary intake has been fairly constant over the past decade when many manufacturing changes occurred. PMID:23018201

Vestergren, Robin; Berger, Urs; Glynn, Anders; Cousins, Ian T

2012-09-24

113

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 ...

114

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

Microsoft Academic Search

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

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

2010-01-01

115

Quantitative determination of perfluorooctanoic acid ammonium salt in human serum by high-performance liquid chromatography with atmospheric pressure chemical ionization tandem mass spectrometry.  

PubMed

A sensitive, specific, accurate and reproducible analytical method was developed and validated to quantify perfluorooctanoic acid (PFOA) in human serum. After initial extraction with an ion-paring reagent, the procedure for quantifying PFOA is based on high-performance liquid chromatography (HPLC) interfaced to negative ion tandem mass spectrometry, operating in selected ion monitoring mode. The retention times of PFOA and its internal standard (D,L-malic acid) were 5.85 and 1.70 min, respectively. The assay was linear over the range 0-500 ng/mL, with a lower limit of quantification (LOQ) of 25 ng/mL, and with a coefficient of variation (CV) of 7.3%. The lower limit of detection (LOD) was assessed as 10 ng/mL. The overall precision and accuracy were assessed on three different days. The within- and between-day precision was < or =9.7 and 6.8%, respectively, and the accuracy was in the range 96-114%. The mean extracted recovery assessed at three different concentrations (100, 250, and 500 ng/mL) was always more than 85%. With this method no derivatization procedure was needed, thus avoiding possible thermal and chemical decomposition reactions of PFOA. The assay was applied to quantify perfluorooctanoic acid in serum from employees exposed to fluorochemicals commonly used in industrial applications for polymer production. The quantitative results for PFOA blood levels were found to vary between 100 and 982 ng/mL. PMID:11921242

Sottani, Cristina; Minoia, Claudio

2002-01-01

116

Determination of misoprostol free acid in human breast milk and serum by gas chromatography/negative ion chemical ionization tandem mass spectrometry.  

PubMed

To study an expected transition of misoprostol from human blood into breast milk, a novel method for the determination of its active metabolite misoprostol acid (MPA) was developed. MPA was determined in serum and breast milk samples by an isotope dilution assay using gas chromatography/negative ion chemical ionization tandem mass spectrometry (GC/NICI-MS/MS). After addition of (15S)-15-methylprostaglandin E(2) (15-methyl-PGE(2)) as an internal standard, MPA was extracted from both matrices using a reversed-phase cartridge. The prostanoids were derivatized with O-2,3,4,5,6-pentafluorobenzylhydroxylamine hydrochloride (PFBHA) and 2,3,4,5,6-pentafluorobenzyl bromide (PFBB) to the pentafluorobenzyl oxime (PFBO)-pentafluorobenzyl ester (PFB) derivatives. The sample was subjected to thin-layer chromatography with ethyl acetate-hexane (1 : 1 (v/v)) as the developing solvent. The corresponding zone was extracted. After derivatization to the trimethylsilyl ether, MPA was determined by GC/NICI-MS/MS using the [molecule (M) - pentafluorobenzyl (PFB)](-) ([P](-)) ions as precursor in the negative ion chemical ionization mode. The product ions used for quantification were [P - 2TMSOH - C(6)F(5)CH(2)OH](-) (MPA) and [P - 2TMSOH - C(6)F(5)CH(2)OH - CO(2)](-)(15-methyl-PGE(2)), respectively. The limit of quantification for MPA was approximately 1 pg ml(-1) in breast milk and serum samples. The correlation coefficients of the calibration curves for MPA were r > 0.997 in the 0.5-2000 pg ml(-1) range for both tested matrices. PMID:12271435

Watzer, Bernhard; Seyberth, Hannsjörg W; Schweer, Horst

2002-09-01

117

Perfluoroalkyl contaminants in an Arctic marine food web: trophic magnification and wildlife exposure.  

PubMed

To better understand the bioaccumulation behavior of perfluoroalkyl contaminants (PFCs), we conducted a comparative analysis of PFCs and lipophilic organohalogens in a Canadian Arctic marine food web. Concentrations of perfluorooctane sulfonic acid (PFOS), perfluorooctansulfoamide (PFOSA), and C7-C14 perfluorocarboxylic acids (PFCAs) ranged between 0.01 and 0.1 ng x g(-1) dry wt in sediments and 0.1 and 40 ng x g(-1) wet wt in biota, which was equivalent to or higher than levels of PCBs, PBDEs, and organochlorine pesticides. In beluga whales, PFOS and PFCA concentrations were higher (P < 0.05) in protein-rich compartments (liver and blood), compared to other tissues/fluids (milk, blubber, muscle, and fetus). In the marine mammalian food web, concentrations of PFOSA and lipophilic organochlorines (ng x g(-1) lipid equivalent) and proteinophilic substances (i.e., PFOS and C8-C14 PFCAs, ng x g(-1) protein) increased significantly (P < 0.05) with trophic level. Trophic magnification factors (TMFs) of organochlorines ranged between 5 and 14 and exhibited significant curvilinear relationships (P < 0.05) with octanol-water and octanol-air partition coefficients (KOW, KOA). TMFs of perfluorinated acids (PFAs) ranged between 2 and 11 and exhibited similar correlation (P < 0.05) with protein-water and protein-air partition coefficients (KPW, KPA). PFAs did not biomagnify in the aquatic piscivorous food web (TMF range: 0.3-2). This food web specific biomagnification behavior was attributed to the high aqueous solubility and low volatility of PFAs. Specifically, the anticipated phase-partitioning of these proteinophilic substances, represented by their protein-water (KPW) and protein-air (KPA) partition coefficients, likely results in efficient respiratory elimination in water-respiring organisms but very slow elimination and biomagnification in air-breathing animals. Lastly, the results indicate that PFOS exposure in nursing Hudson Bay beluga whale calves (CI95 range = 2.7 x 10(-5) to 1.8 x 10(-4) mg x kg bw(-1) x d(-1)), exceedsthe oral reference dose for PFOS (7.5 x 10(-5) mg x kg bw(-1) x d(-1)), which raises concern for potential biological effects in these and other sensitive Arctic marine wildlife species. PMID:19569327

Kelly, Barry C; Ikonomou, Michael G; Blair, Joel D; Surridge, Blair; Hoover, Dale; Grace, Richard; Gobas, Frank A P C

2009-06-01

118

Neutral poly- and perfluoroalkyl substances in air and seawater of the North Sea.  

PubMed

Concentrations of neutral poly- and perfluoroalkyl substances (PFASs), such as fluorotelomer alcohols (FTOHs), perfluoroalkane sulfonamides (FASAs), perfluoroalkane sufonamidoethanols (FASEs), and fluorotelomer acrylates (FTACs), have been simultaneously determined in surface seawater and the atmosphere of the North Sea. Seawater and air samples were taken aboard the German research vessel Heincke on the cruise 303 from 15 to 24 May 2009. The concentrations of FTOHs, FASAs, FASEs, and FTACs in the dissolved phase were 2.6-74, <0.1-19, <0.1-63, and <1.0-9.0 pg L(-1), respectively. The highest concentrations were determined in the estuary of the Weser and Elbe rivers and a decreasing concentration profile appeared with increasing distance from the coast toward the central part of the North Sea. Gaseous FTOHs, FASAs, FASEs, and FTACs were in the range of 36-126, 3.1-26, 3.7-19, and 0.8-5.6 pg m(-3), which were consistent with the concentrations determined in 2007 in the North Sea, and approximately five times lower than those reported for an urban area of Northern Germany. These results suggested continuous continental emissions of neutral PFASs followed by transport toward the marine environment. Air-seawater gas exchanges of neutral PFASs were estimated using fugacity ratios and the two-film resistance model based upon paired air-seawater concentrations and estimated Henry's law constant values. Volatilization dominated for all neutral PFASs in the North Sea. The air-seawater gas exchange fluxes were in the range of 2.5?×?10(3)-3.6?×?10(5) pg m(-2) for FTOHs, 1.8?×?10(2)-1.0?×?10(5) pg m(-2) for FASAs, 1.1?×?10(2)-3.0?×?10(5) pg m(-2) for FASEs and 6.3?×?10(2)-2.0?×?10(4) pg m(-2) for FTACs, respectively. These results suggest that the air-seawater gas exchange is an important process that intervenes in the transport and fate for neutral PFASs in the marine environment. PMID:23636599

Xie, Zhiyong; Zhao, Zhen; Möller, Axel; Wolschke, Hendrik; Ahrens, Lutz; Sturm, Renate; Ebinghaus, Ralf

2013-05-02

119

Development of a new chemically modified carbon paste electrode for selective determination of urinary and serum oxalate concentration.  

PubMed

The construction and evaluation of a novel modified carbon paste electrode with high selectivity toward oxalate ion are described. The constructed carbon paste potentiometric sensor for oxalate ion is based on the use of a zirconium salan complex as a good ionophore in the carbon paste matrix. The electrode exhibits a Nernstian slope of 29.1mV/decade to oxalate ion over a wide concentration range from 1.5×10(-6) to 3.9 ×10(-2)molL(-1) with a low detection limit of 7.0×10(-7)molL(-1). The electrode possesses fast response time, satisfactory reproducibility, appropriate lifetime, and most importantly, good selectivity toward C2O4(2-) relative to a variety of common anions. The potentiometric response of the electrode is independent of the pH of the test solution in the pH range 2.5-8.0. The modified carbon paste electrode was successfully applied as an indicator electrode in potentiometric titration and potentiometric determination of oxalate ion in mineral water, blood serum and urine samples. PMID:24148425

Soleymanpour, Ahmad; Shafaatian, Bita; Sadat Mirfakhraei, Homeira; Rezaeifard, Abdolreza

2013-07-11

120

Increased expression of heat shock protein 90 under chemical hypoxic conditions protects cardiomyocytes against injury induced by serum and glucose deprivation.  

PubMed

Heat shock proteins (HSPs) are critical for adaptation to hypoxia and/or ischemia. Previously, we demonstrated that cobalt chloride (CoCl2), a well-known hypoxia mimetic agent, is an inducer of HSP90. In the present study, we tested the hypothesis that CoCl?-induced upregulation of HSP90 is able to provide cardioprotection in serum and glucose-deprived H9c2 cardiomyocytes (H9c2 cells). Cell viability was detected using a CCK-8 assay, while HSP90 expression was detected via western blotting. The findings of this study showed that serum and glucose deprivation (SGD) induced significant cytotoxicity, overproduction of reactive oxygen species (ROS) and a loss of mitochondrial membrane potential (MMP) in H9c2 cells. In addition, SGD downregulated the expression of HSP90 in a time-dependent manner. The selective inhibitor of HSP90 17-allylamino-17-demethoxygeldanamycin (17-AAG) aggravated SGD-induced cytotoxicity. CoCl? at 100 µM time-dependently enhanced the expression of HSP90. Treatment with CoCl? from 50 to 200 µM significantly attenuated cytotoxicity and the downregulation of HSP90 expression induced by SGD for 24 h, respectively. Notably, pretreatment of H9c2 cells with 17-AAG at 2 µM for 60 min before exposure to both CoCl2 (100 µM) and SGD significantly blocked the CoCl2-induced cardioprotective effect, demonstrated by decreased cell viability and MMP loss, as well as increased ROS generation. Taken together, these results suggest that HSP90 may be one of the endogenous defensive mechanisms for resisting ischemia-like injury in H9c2 cells, and that HSP90 plays an important role in chemical hypoxia-induced cardioprotection against SGD-induced injury by its antioxidation and preservation of mitochondrial function. PMID:22922826

Wu, Keng; Xu, Wenming; You, Qiong; Guo, Runmin; Feng, Jianqiang; Zhang, Changran; Wu, Wen

2012-08-20

121

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.

Bedner, Mary; Phinney, Karen W.

2012-01-01

122

Determination of polychlorinated biphenyls in serum using gas chromatography-mass spectrometry with negative chemical ionization for exposure estimation.  

PubMed

A sensitive and selective method for the determination of 24 polychlorinated biphenyls (PCBs) by gas chromatography-mass spectrometry with negative chemical ionization (GC-MS-NCI) was applied for the recent needs of occupational exposure in waste incineration. The three most abundant ions were used in determining compounds with at least five chlorine atoms in the PCB molecule. Selecting ions Cl(35) and Cl(37) for di-, tri-, and tetrachlorinated PCBs resulted in reliable quantification of these compounds. The detection limits for the 24 individual compounds varied from 0.01 to 0.08 microg/l. The recovery of the method was 113+/-16%. Stability tests showed no degradation of the compounds studied during 6 weeks. The sum of 24 PCB compounds measured from the sera of workers in a disposal plant was 1.9-10.9 microg/l, and 0.3-3.0 microg/l for controls, respectively. The mean proportion of the low chlorinated PCB compounds (with four or less chlorine atoms) was 20% for workers in the disposal plant and 14% for the controls. PMID:12798172

Kontsas, Helena; Pekari, Kaija

2003-07-01

123

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

124

Synthesis and 31P chemical shift identification of tripeptide active site models that represent human serum acetylcholinesterase covalently modified at serine by certain organophosphates.  

PubMed

Most organophosphorus (OP) insecticides impart their toxic action via inhibition of cholinesterases by reacting at an essential serine hydroxyl group. The inhibition process is dependent upon the reactivity, stereochemistry, leaving group, and the mechanism of phosphorylation and/or reactivation (or aging) inherent to the OP compound under consideration. Because a wide array of phosphorylated structures are possible following inhibition by an OP, a simple model system was sought to investigate the mechanistic details of these and related reactions. In the present study, the tripeptide N-CBZ-Glu-Ser(OH)-Ala-OEt (chosen as a truncated form of human serum cholinesterase) was chemically modified at the serine hydroxyl group by various O-methyl phosphate groups and the 31P NMR chemical shift recorded. Six tripeptides, representing (a) phosphorylation by dimethyl phosphorothionates (N-CBZ-Glu-Ser[O-P(S)(OMe)2]Ala-OEt; 5), (b) phosphorylation by dimethyl phosphates (N-CBZ-Glu-Ser[O-P(O)(OMe)2] Ala-Oet; 6), (c) phosphorylation by O,S-dimethyl phosphorothiolates (N-CBZ-Glu-Ser[O-P(O)(OMe)(SMe)]Ala-OEt; 7), (d) aging following inhibition by dimethyl phosphorothionates (N-CBZ-Glu-Ser[O-P(O)(OMe)(S-)]Ala-OEt; 8), (e) aging following inhibition by dimethyl phosphates (N-CBZ-Glu-Ser[O-P(O)(OMe)(O-)]Ala-OEt; 9), and (f) phosphorylation by R/S)PSc-isomalathion stereoisomers (N-CBZ-Glu-Ser[O-P(O)(OMe)(SCH(CO2CO2Et)CH2-CO2Et)]Ala-OEt; 10) have been synthesized. Tripeptides 5 and 6 were prepared via preliminary formation of an intermediate tripeptide phosphite followed by direct conversion to 5 using S8 or to 6 with m-CPBA, respectively. Tripeptides 8 and 9 were prepared by dealkylation of 5 and 6, respectively. Tripeptides 7 and 10 were prepared by reaction of 8 with dimethyl sulfate and (R)- or (S)-diethyl (trifluoromethanesulfonyl)malate, respectively. PMID:8951236

Thompson, C M; Suarez, A I; Rodriguez, O P

1996-12-01

125

Correlation of Endocrine Disrupting Chemicals Serum Levels and White Blood Cells Gene Expression of Nuclear Receptors in a Population of Infertile Women  

PubMed Central

Significant evidence supports that many endocrine disrupting chemicals could affect female reproductive health. Aim of this study was to compare the internal exposure to bisphenol A (BPA), perfluorooctane sulphonate (PFOS), perfluorooctanoic acid (PFOA), monoethylhexyl phthalate (MEHP), and di(2-ethylhexyl) phthalate (DEHP) in serum samples of 111 infertile women and 44 fertile women. Levels of gene expression of nuclear receptors (ER?, ER?, AR, AhR, PXR, and PPAR?) were also analyzed as biomarkers of effective dose. The percentage of women with BPA concentrations above the limit of detection was significantly higher in infertile women than in controls. No statistically significant difference was found with regard to PFOS, PFOA, MEHP and DEHP. Infertile patients showed gene expression levels of ER?, ER?, AR, and PXR significantly higher than controls. In infertile women, a positive association was found between BPA and MEHP levels and ER?, ER?, AR, AhR, and PXR expression. PFOS concentration positively correlated with AR and PXR expression. PFOA levels negatively correlated with AhR expression. No correlation was found between DEHP levels and all evaluated nuclear receptors. This study underlines the need to provide special attention to substances that are still widely present in the environment and to integrate exposure measurements with relevant indicators of biological effects.

Caserta, Donatella; Ciardo, Francesca; Bordi, Giulia; Guerranti, Cristiana; Fanello, Emiliano; Perra, Guido; Borghini, Francesca; La Rocca, Cinzia; Tait, Sabrina; Bergamasco, Bruno; Stecca, Laura; Marci, Roberto; Lo Monte, Giuseppe; Soave, Ilaria; Focardi, Silvano; Mantovani, Alberto; Moscarini, Massimo

2013-01-01

126

Specific estrogen-induced cell proliferation of cultured Syrian hamster renal proximal tubular cells in serum-free chemically defined media  

SciTech Connect

It has long been recognized that the renal proximal tubular epithelium of the hamster is a bona fide estrogen target tissue. The effect of estrogens on the growth of proximal tubule cell explants and dissociated single cells derived from these explant outgrowths has been studied in culture. Renal tubular cells were grown on a PF-HR-9 basement membrane under serum-free chemically defined culture conditions. At 7-14 days in culture, cell number was enhanced 3-fold in the presence of either 17{beta}-estradiol or diethylstilbestrol. A similar 3-fold increase in cell number was also seen at 1 nM 17{beta}-estradiol in subcultured dissociated single tubular cells derived from hamster renal tubular explant outgrowths at 21 days in culture. Concomitant exposure of tamoxifen at 3-fold molar excess in culture completely abolished the increase in cell number seen with 17{beta}-estradiol. The proliferation effect of estrogens on proximal tubular cell growth appears to be species specific since 17{beta}-estradiol did not alter the growth of either rat or guinea pig proximal tubules in culture. In addition, at 7-10 days in culture in the presence of 17{beta}-estradiol, ({sup 3}H)thymidine labeling of hamster tubular cells was enhanced 3-fold. These results clearly indicate that estrogens can directly induce primary epithelial cell proliferation at physiologic concentrations and provide strong additional evidence for an important hormonal role in the neoplastic transformation of the hamster kidney.

Oberley, T.D.; Lauchner, L.J.; Pugh, T.D.; Gonzalez, A.; Goldfarb, S. (Univ. of Wisconsin Medical School, Madison (USA)); Li, S.A.; Li, J.J. (Univ. of Minnesota Medical School, Minneapolis (USA))

1989-03-01

127

Mechanisms of perfluoroalkyl acid (PFAA) toxicity: Involvement of peroxisome proliferator activator receptor alpha (PPAR) molecular signals.  

EPA Science Inventory

Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are members of a family of environmentally persistent perfluorinated compounds and are found in the serum of wildlife and humans. PFOS and PFOA are developmentally toxic in rats and mice. Exposure in utero reduces...

128

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.

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

2011-01-01

129

Novel perfluoroalkylated derivatives of D-galactopyranose and xylitol for biomedical uses. Hemocompatibility and effect on perfluorocarbon emulsions.  

PubMed

6-O-(4,4,5,5,6,6,7,7,7-Nonafluoro-2-hydroxyheptyl)-, 6-O-(4,4,5,5,6,6,7,7,8,8,9,9,9-tridecafluoro-2-hydroxynonyl)-, and 6-O-(4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,11-heptadecafluoro-2-hydroxyundecyl)-d-galactopyranose (9, 10, and 11, resp.) were prepared by a two-step synthesis including the reaction of 1,2:3,4-di-O-isopropylidene-alpha-d-galactopyranose with 2-[(perfluoroalkyl)methyl]oxiranes under catalysis with BF(3).Et(2)O. Similarly, 1-O-(4,4,5,5,6,6,7,7,7-nonafluoro-2-hydroxyheptyl)-, 1-O-(4,4,5,5,6,6,7,7,8,8,9,9,9-tridecafluoro-2-hydroxynonyl)-, 1-O-(4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,11-heptadecafluoro-2-hydroxyundecyl)-dl-xylitol (18, 19, and 20, resp.) were prepared by a two-step synthesis from the corresponding 1,2:3,4-di-O-isopropylidene-dl-xylitol. Most of the both types of fluoroalkylated carbohydrate derivatives 9-11 and 18-20 generally displayed very low level of hemolytic activity and excellent co-emulsifying properties on testing on perfluorodecalin-Pluronic F-68 microemulsions. PMID:15337445

Církva, Vladimír; Polák, Radek; Paleta, Oldrich; Kefurt, Karel; Moravcová, Jitka; Kodícek, Milan; Forman, Stanislav

2004-09-13

130

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

2010-11-03

131

Induction of cell-cell connections by using in situ laser lithography on a perfluoroalkyl-coated cultivation platform.  

PubMed

This article describes a novel laser-directed microfabrication method carried out in aqueous solution for the organization of cell networks on a platform. A femtosecond (fs) laser was applied to a platform culturing PC12, HeLa, or normal human astrocyte (NHA) cells to manipulate them and to facilitate mutual connections. By applying an fs-laser-induced impulsive force, cells were detached from their original location on the plate, and translocated onto microfabricated cell-adhesive domains that were surrounded with a cell-repellent perfluoroalkyl (R(f)) polymer. Then the fs-laser pulse-train was applied to the R(f) polymer surface to modify the cell-repellent surface, and to make cell-adhesive channels of several ?m in width between each cell-adhesive domain. PC12 cells elongated along the channels and made contact with others cells. HeLa and NHA cells also migrated along the channels and connected to the other cells. Surface analysis by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) confirmed that the R(f) polymer was partially decomposed. The method presented here could contribute not only to the study of developing networks of neuronal, glial, and capillary cells, but also to the quantitative analysis of nerve function. PMID:21341350

Okano, Kazunori; Yu, David; Matsui, Ai; Maezawa, Yasuyo; Hosokawa, Yoichiroh; Kira, Atsushi; Matsubara, Mie; Liau, Ian; Tsubokawa, Hiroshi; Masuhara, Hiroshi

2011-02-21

132

Micro-quantitation of lipids in serum-free cell culture media: a critical aspect is the minimization of interference from medium components and chemical reagents  

Microsoft Academic Search

Lipids (fatty acids) at a concentration range of 10–100?g\\/L are essential components included in most serum-free cell culture medium formulations. A gas chromatography\\/mass spectrometry (GC\\/MS) method for the micro-quantitation of lipids, determined as fatty acid methyl esters (FAMEs), in complex serum-free cell culture media was developed. The interference of derivatizing reagents, extraction solvents and medium additives in the micro-quantitation of

Chun Fang Shen; Jalal Hawari; Amine Kamen

2004-01-01

133

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

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

2013-05-31

134

Occurrence of perfluoroalkyl substances (PFASs) in various food items of animal origin collected in four European countries.  

PubMed

This study summarises the results of the levels of 21 perfluoroalkyl substances (PFASs) in 50 selected pooled samples representing 15 food commodities with the special focus on those of animal origin, as meat, seafood, fish, milk, dairy products and hen eggs, which are commonly consumed in various European markets, e.g. Czech, Italian, Belgian and Norwegian. A new, rapid sample preparation approach based on the QuEChERS extraction procedure was applied. Ultra-performance liquid chromatography (UHPLC) coupled to tandem mass spectrometry (MS/MS) employing electrospray ionisation (ESI) in negative mode was used for the quantification of target analytes. Method quantification limits (MQLs) were in the range of 1-10 ng kg(-1) (ng l(-1)) for fish, meat, hen eggs, cheese and milk, and in the range of 2.5-125 ng kg(-1) for butter. Only 16 of the group of 21 PFASs were found in at least one analysed sample. From 16 PFASs, perfluorooctane sulfonate (PFOS) was the most frequently detected analyte present in approximately 50% of samples (in the range of 0.98-2600 ng kg(-1)). PFCAs with C8-C14 carbon chain were presented in approximately 20% of samples. The concentration ranges of individual compounds in the respective groups of PFASs were: 2.33-76.3 ng kg(-1) for PFSAs (without PFOS), 4.99-961 ng kg(-1) for PFCAs, 10.6-95.4 ng kg(-1) for PFPAs, and 1.61-519 ng kg(-1) for FOSA. The contamination level in the analysed food commodities decreased in the following order: seafood > pig/bovine liver > freshwater/marine fish > hen egg > meat > butter. When comparing the total contamination and profiles of PFASs in food commodities that originated from various sampling countries, differences were identified, and the contents decreased as follows: Belgium > Norway, Italy > Czech Republic. PMID:24107131

Hlouskova, Veronika; Hradkova, Petra; Poustka, Jan; Brambilla, Gianfranco; De Filipps, Stefania Paola; D'Hollander, Wendy; Bervoets, Lieven; Herzke, Dorte; Huber, Sandra; de Voogt, Pim; Pulkrabova, Jana

2013-10-09

135

Perfluoroalkyl substances in UK indoor and outdoor air: spatial and seasonal variation, and implications for human exposure.  

PubMed

This study reports atmospheric concentrations of a number of perfluoroalkyl substances (PFASs) in homes, offices, and outdoor locations in Birmingham, UK during 2008 and 2009. Concentrations indoors exceed significantly those outdoors, suggesting indoor emissions are driving outdoor contamination. The exception is N-ethyl perfluorooctane sulfonamide (EtFOSA), for which indoor and outdoor concentrations are statistically indistinguishable, implying other sources for this compound. Concentrations of all PFASs at 10 urban outdoor locations showed little spatial variability (RSD=53-85%). At 2 urban locations and 1 semi-rural location in England, monthly variations in outdoor concentrations were measured over 1 year and shown to be in line (RSD=39-110%) with the low spatial variability in Birmingham. This low spatial and temporal variability implies sources at locations monitored are diffuse in nature. Concentrations of N-ethyl perfluorooctanesulfonamidoethanol (EtFOSE) in outdoor air were significantly higher at one of the Birmingham urban sites than at the semi-rural location. Indoor concentrations of perfluorohexanesulfonate (PFHxS) exceeded those of perfluorooctanesulfonate (PFOS). Combined with the fact that PFHxS concentrations in outdoor air in this study exceed substantially those measured in the UK in 2005; this is consistent with the hypothesis that PFHxS use is increasing in response to restrictions on the use of PFOS. Concentrations of PFOS in offices exceed significantly those in homes. Month-to-month variations in concentrations in 4 living rooms and 1 office were measured over a year. Relative standard deviations (RSD) for individual PFASs in these locations were 47-160%, providing information about the uncertainty associated with exposure assessments based on single measurements. The observed variability could not be attributed to changes in room contents, nor to seasonality. Human exposure via inhalation appears a minor pathway. PMID:22580294

Goosey, Emma; Harrad, Stuart

2012-05-09

136

Occurrence of perfluoroalkyl carboxylates and sulfonates in drinking water utilities and related waters from the United States.  

PubMed

The prevalence and persistence of perfluoroalkyl compounds (PFCs) in environmental and biological systems has been well documented, and a rising number of reports suggest that certain PFCs can result in adverse health effects in mammals. As traditional water sources become increasingly impacted by waste discharge and the demand for planned potable reuse grows, there is recent interest in determining PFC occurrence in drinking water supplies. Here we report monitoring results from drinking water treatment facility samples collected across the United States, and from associated surface, ground, and wastewater sources. Using automated solid phase extraction (SPE) and isotope-dilution liquid chromatography/tandem mass spectrometry (LC/MS-MS), samples were screened for perfluorohexanoic acid (PFHxA), perfluorohexanesulfonate (PFHxS), perfluorooctanoic acid (PFOA), perfluorooctanesulfonate (PFOS), perfluorononanoic acid (PFNA) perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUdA), and perfluorododecanoic acid (PFDoA). Method reporting limits (MRLs) were established at 1.0 ng/L for all monitored PFCs except PFOA, for which the MRL was set at 5.0 ng/L given elevated procedural and instrumental background levels. PFOS was the only investigated PFC detected in minimally impacted surface waters, with individual site averages of 2.0 ng/L and lower. Conversely, wastewater treatment plant (WWTP) effluents and other highly impacted waters had almost 100% detection frequency for all PFCs except PFUdA and PFDoA, which were not detected above MRL in any samples. Of the investigated PFCs, PFOA averaged the highest overall concentration at any site at 115 ng/L. Substantial impacts from treated wastewater generally caused increased summed PFC concentrations at downstream drinking water facilities, although levels and distribution suggest geographical variability. No discernible differences between influent and effluent PFC levels were observed for drinking water facilities. Removal of PFCs, however, was observed at an indirect potable reuse facility using microfiltration and reverse osmosis for wastewater treatment, in which case all PFC levels in effluents were below the MRL. PMID:20000497

Quiñones, Oscar; Snyder, Shane A

2009-12-15

137

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

138

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

2013-03-06

139

Syntheses with perfluoroalkyl iodides. Part II. Addition to non-conjugated alkadienes; cyclization of 1,6-heptadiene, and of 4-substituted 1,6-heptadienoic compounds: bis-allyl ether, ethyl diallylmalonate, N, N?-diallylamine and N-substituted diallylamines; and additions to homologous exo- and endocyclic alkenes, and to bicyclic alkenes  

Microsoft Academic Search

Non-conjugated dienes, with an azonitrile initiator, add one or two RFI to provide RFRH “diblock” and RFRHRF “triblock” compounds with one, or two perfluoroalkyl groups, respectively. Those diblock products with long fluorocarbon and hydrocarbon segments furnish novel surfactants for fluorocarbon liquid systems, and are cell structure modifiers for biochemical applications. In the case of 1,6-heptadiene, the perfluoroalkyl radical adds first

Neal O. Brace

1999-01-01

140

Micro-quantitation of lipids in serum-free cell culture media: a critical aspect is the minimization of interference from medium components and chemical reagents.  

PubMed

Lipids (fatty acids) at a concentration range of 10-100 microg/L are essential components included in most serum-free cell culture medium formulations. A gas chromatography/mass spectrometry (GC/MS) method for the micro-quantitation of lipids, determined as fatty acid methyl esters (FAMEs), in complex serum-free cell culture media was developed. The interference of derivatizing reagents, extraction solvents and medium additives in the micro-quantitation of lipids was also examined. The results show that the concentration of fatty acids such as palmitic and stearic acids detected in derivatizing reagents or extraction solvents was in the range of 10-230 microg/L. Tween-80, a surfactant and medium additive, produced nearly 20 FAMEs alone when methylated using a derivatizing agent. Moreover, the surfactant Pluronic F-68, a medium additive, interfered in the FAME recovery. Procedures, which include use of low volumetric ratio of reagent to medium and precipitation of the above surfactants, were developed to minimize background FAMEs to levels which do not significantly affect the quantitation of medium lipids and to diminish the interference caused by Pluronic F-68. Fatty acid concentrations in several complex serum-free culture media were quantitated by this method and were very close to the values indicated in their formulations. PMID:15358315

Shen, Chun Fang; Hawari, Jalal; Kamen, Amine

2004-10-15

141

Perfluoroalkyl substances in polar bear mother-cub pairs: a comparative study based on plasma levels from 1998 and 2008.  

PubMed

Perfluoroalkyl substances (PFASs) are protein-binding blood-accumulating contaminants that may have detrimental toxicological effects on the early phases of mammalian development. To enable an evaluation of the potential health risks of PFAS exposure for polar bears (Ursus maritimus), an exposure assessment was made by examining plasma levels of PFASs in polar bear mothers in relation to their suckling cubs-of-the-year (~4 months old). Samples were collected at Svalbard in 1998 and 2008, and we investigated the between-year differences in levels of PFASs. Seven perfluorinated carboxylic acids (??PFCAs: PFHpA, PFOA, PFNA, PFDA, PFUnDA, PFDoDA, and PFTrDA) and two perfluorinated sulfonic acids (??PFSAs: PFHxS and PFOS) were detected in the majority of the mothers and cubs from both years. In mothers and cubs, most PFCAs were detected in higher concentrations in 2008 than in 1998. On the contrary, levels of PFOS were lower in 2008 than in 1998, while levels of PFHxS did not differ between the two sampling years. PFOS was the dominating compound in mothers and cubs both in 1998 and in 2008. Concentration of PFHpA did not differ between mothers and cubs, while concentrations of PFOA, PFNA, PFDA, PFUnDA, PFDoDA, PFTrDA, PFHxS, and PFOS were higher in mothers than in their cubs. Except from PFHpA, all compounds correlated significantly between mothers and their cubs. The mean cub to mother ratios ranged from 0.15 for PFNA to 1.69 for PFHpA. On average (mean±standard error of mean), the levels of ??PFCAs and ??PFSAs in cubs were 0.24±0.01 and 0.22±0.01 times the levels in their mothers, respectively. Although maternal transfer appears to be a substantial source of exposure for the cubs, the low cub to mother ratios indicate that maternal transfer of PFASs in polar bears is relatively low in comparison with hydrophobic contaminants (e.g. PCBs). Because the level of several PFASs in mothers and cubs from both sampling years exceeded the levels associated with health effects in humans, our findings raise concern on the potential health effects of PFASs in polar bears from Svalbard. Effort should be made to examine the potential health effects of PFASs in polar bears. PMID:23010253

Bytingsvik, Jenny; van Leeuwen, Stefan P J; Hamers, Timo; Swart, Kees; Aars, Jon; Lie, Elisabeth; Nilsen, Else Mari Espseth; Wiig, Oystein; Derocher, Andrew E; Jenssen, Bjørn M

2012-09-23

142

Perfluoroalkyl contaminants in Lake Ontario Lake Trout: detailed examination of current status and long-term trends.  

PubMed

Perfluoroalkyl contaminants (PFCs) were determined in Lake Ontario Lake Trout sampled annually between 1997 and 2008 in order to assess how current trends are responding to recent regulatory bans and voluntary phase-outs. We also combined our measurements with those of a previous study to provide an updated assessment of long-term trends. Concentrations of PFCs generally increased from the late 1970s until the mid-1980s to mid-1990s, after which concentrations either remained unchanged (perfluorooctane sulfonate (PFOS) and perfluorocarboxylates) or declined (perfluorodecanesulfonate (PFDS)). The temporal trends were assessed using three models, quadratic, exponential rise to maximum, and two-segment linear piecewise function, and then evaluated for best fit using Akaike Information Criteria. For PFOS and perfluorocarboxylates, the exponential rise to maximum function had the best fit. This is particularly interesting for PFOS as it suggests that although concentrations in Lake Ontario Lake Trout may have stopped increasing in response to voluntary phase-outs in 2000-2002, declines have yet to be observed. This may be due to continuing input of PFOS from products still in use and/or slow degradation of larger precursor molecules. A power analysis of PFOS suggested that 15 years of data with a within-year sample size of 10 is required to obtain sufficient power (80%) to detect a 5% decreasing trend. However, the length of the monitoring program had a greater influence on the ability to detect a trend compared to within-year sample size. This provides evidence that additional sampling years are required to detect a response to bans and phase-outs, given the variability in the fish data. The lack of observed declines of perfluorocarboxylate residues in fish may be expected as regulations for these compounds were only recently enacted. In contrast to the other compounds, the quadratic model had the best fit for PFDS. The results of this study emphasize the importance of long-term monitoring for assessing the effectiveness of bans and phase-outs on PFCs in the environment. PMID:22553902

Gewurtz, Sarah B; De Silva, Amila O; Backus, Sean M; McGoldrick, Daryl J; Keir, Michael J; Small, Jeff; Melymuk, Lisa; Muir, Derek C G

2012-05-17

143

Quantitation of gas-phase perfluoroalkyl surfactants and fluorotelomer alcohols released from nonstick cookware and microwave popcorn bags.  

PubMed

Fluoropolymer dispersions are used for coating certain cookware products and food-contact packaging to impart oil and water repellency. Since salts of perfluorooctanoic acid (PFOA) are used as a processing aid in the manufacture of many fluoropolymers, it is necessary to determine if these compounds are still present as residuals after the process used to coat nonstick cookware or packaging, and could be released during typical cooking conditions. In this study, we identified and measured perfluoroalkyl carboxylates (PFCAs), particularly PFOA, and fluorotelomer alcohols (FTOHs; 6:2 FTOH and 8:2 FTOH), released from nonstick cookware into the gas phase under normal cooking temperatures (179 to 233 degrees C surface temperature). PFOA was released into the gas phase at 7-337 ng (11-503 pg/cm2) per pan from four brands of nonstick frying pans. 6:2 FTOH and 8:2 FTOH were found in the gas phase of four brands of frying pans, and the sources of FTOHs released from nonstick cookware are under investigation. We observed a significant decrease in gas-phase PFOA following repeated use of one brand of pan, whereas the other brand did not show a significant reduction in PFOA release following multiple uses. PFOA was found at >5 ng during the fourth use of both brands of pans. FTOHs were not found after the second use of either brand of pans. PFOA was found at 5-34 ng in the vapors produced from a prepacked microwave popcorn bag. PFOA was not found in the vapors produced from plain white corn kernels popped in a polypropylene container. 6:2 FTOH and 8:2 FTOH were measured in the vapors produced from one brand of prepacked microwave popcorn at 223 + 37 ng and 258 +/- 36 ng per bag, respectively, but not measured at >20 ng (LOQ) in the other two brands. On the packaging surface of one brand of microwave popcorn several PFCAs, including C5-C12, 6:2 FTOH, and 8:2 FTOH, were found at concentrations in the order of 0.5-6.0 ng/cm2. This study suggests that residual PFOA is not completely removed during the fabrication process of the nonstick coating for cookware. They remain as residuals on the surface and may be off-gassed when heated at normal cooking temperatures. PMID:17593716

Sinclair, Ewan; Kim, Seung Kyu; Akinleye, Henry B; Kannan, Kurunthachalam

2007-02-15

144

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...

145

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

2013-03-14

146

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); Ghosh, A. [Univ., of Tromso (Norway)

1996-09-04

147

New Perfluoroalkylated Phosphorus Amphiphiles  

Microsoft Academic Search

Phospholipids are the main components of biological membranes and the) spontaneously tend to self-assembly into liposomes. Synthetic double-chain so as bol amphiphiles allow the preparation of vesicles and can bc used as models of natural membranes and for preparing drug delivery systems. The formation of vesicles from single-chain perfluomalkylated phosphate or phosphoramidate amphiphiles war recently reported. We present the synthesis

A. Brun; D. Albouy; G. Etemad-moghadam; I. Rico-lattes; A. Lattes

1999-01-01

148

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

2011-03-07

149

Estimation of the Acid Dissociation Constant of Perfluoroalkyl Carboxylic Acids through an Experimental Investigation of their Water-to-Air Transport.  

PubMed

The acid dissociation constants (pKas) of perfluoroalkyl carboxylic acids (PFCAs) have been the subject of discussion in the literature; for example, values from -0.2 to 3.8 have been suggested for perfluorooctanoic acid (PFOA). The dissociated anionic conjugate bases of PFCAs have negligible air-water partition coefficients (KAWs) and do not volatilize from water. The neutral acids, however, have relatively high KAWs and volatilization from water has been demonstrated. The extent of volatilization of PFCAs in the environment will depend on the water pH and their pKa. Knowledge of the pKas of PFCAs is therefore vital for understanding their environmental transport and fate. We investigated the water-to-air transfer of PFCAs in a novel experimental setup. We used ?1 ?g L(-1) of PFCAs in water (above environmental background concentrations but below the concentration at which self-association occurs) at different water pH (pH 0.3 to pH 6.9) and sampled the PFCAs volatilized from water during a 2-day experiment. Our results suggest that the pKas of C4-11 PFCAs are <1.6. For PFOA, we derived a pKa of 0.5 from fitting the experimental measurements with a volatilization model. Perfluoroalkane sulfonic acids were not volatilized, suggesting that their pKas are below the investigated pH range (pKa <0.3). PMID:23952814

Vierke, Lena; Berger, Urs; Cousins, Ian T

2013-09-10

150

Increasing Concentrations of Perfluoroalkyl Acids in Scandinavian Otters (Lutra lutra) between 1972 and 2011: A New Threat to the Otter Population?  

PubMed

Liver samples from 140 otters (Lutra lutra) from Sweden and Norway were analyzed for 10 perfluoroalkyl carboxylic acids (PFCAs; C6-C15), 4 perfluoroalkane sulfonic acids (PFSAs; C4,C6,C8,C10) and perfluorooctane sulfonamide (FOSA). Perfluorooctane sulfonic acid (PFOS) was the dominant compound accounting for approximately 80% of the fluorinated contaminants and showing concentrations up to 16 ?g/g wet weight. Perfluorononanoic acid (PFNA) was the dominant PFCA (up to 640 ng/g wet weight) closely followed by the C10 and C11 homologues. A spatial comparison between otters from southwestern Norway, southern and northern Sweden sampled between 2005 and 2011 revealed that the samples from southern Sweden had generally the largest contaminant load, but two PFCAs and FOSA were higher concentrated in the Norwegian samples. A temporal trend study was performed on otters from southern Sweden collected between 1972 and 2011. Seven PFCAs (C8-C14), PFOS and perfluorodecane sulfonic acid (PFDS) showed significantly increasing trends with doubling times between 5.5 and 13 years. The PFCAs also showed significantly increasing trends over the period 2002 to 2011. These findings together with the exceptionally high liver concentrations of PFOS are of great concern for the Scandinavian otter populations. PMID:24033312

Roos, Anna; Berger, Urs; Järnberg, Ulf; van Dijk, Jiska; Bignert, Anders

2013-09-27

151

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

2008-12-30

152

A Chemical Determination of Isoniazid in Serum.  

National Technical Information Service (NTIS)

An adaptation of a fluorometric method for determining isoniazid was developed, which shortens the length of time required to perform the analysis, and makes possible the use of a simple and inexpensive fluorometer. Excellent correlation was found between...

O. K. Reiss W. C. Morse R. W. Putsch

1967-01-01

153

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.

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

2011-01-01

154

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

2012-12-23

155

A matrix effect-free method for reliable quantification of perfluoroalkyl carboxylic acids and perfluoroalkane sulfonic acids at low parts per trillion levels in dietary samples.  

PubMed

In recent exposure modeling studies diet has been identified as the dominant pathway of human exposure to perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS). However, the paucity of highly sensitive and accurate analytical data to support these studies means that their conclusions are open to question. Here a novel matrix effect-free method is described for ultra-trace analysis of perfluoroalkyl carboxylic acids and perfluoroalkane sulfonic acids in dietary samples of varied composition. The method employs ion pair extraction of the analytes into methyl tert-butyl ether and subsequent solid phase extraction clean-up on Florisil and graphitized carbon. The target compounds are separated and detected using ultra performance liquid chromatography coupled to tandem mass spectrometry. Special care was taken to avoid procedural blank contamination and potential contamination sources were elucidated. The performance of the method was validated for five different food test matrices including a duplicate diet sample. Method detection limits in the low to sub pgg(-1) range were obtained for all target analytes, which is 5-100 times more sensitive than previously reported for duplicate diet samples. Total method recoveries were consistently between 50 and 80% for all analytes in all tested food matrices and effects of co-extracted matrix constituents on ionization of the target compounds were found to be negligible. The precision of the method (defined as percentage relative standard deviation) at concentrations close to the respective method limits of quantification was <15% for all analytes. Accurate quantification at ultra-trace levels was demonstrated by laboratory control spike experiments. For the first time the presence of long-chain PFCAs in duplicate diet samples is reported. The method presented here can thus support an improved assessment of human exposure from dietary intake for a range of PFCA and PFSA homologues. Re-analysis of duplicate diet samples, which had been analyzed earlier using another analytical methodology, indicated that dietary intake of PFOA and PFOS may previously have been overestimated. PMID:22464003

Vestergren, Robin; Ullah, Shahid; Cousins, Ian T; Berger, Urs

2012-03-14

156

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

157

Fetal bovine serum: a multivariate standard.  

PubMed

Chemical and endocrine parameters were investigated in commercially available fetal bovine sera intended for use as culture media supplements. A high degree of serum variability was present both within and between suppliers in all major categories investigated. It is suggested that caution be employed in the interpretation of results from experiments utilizing serum supplements without specific quantitation of possible interfering or modulating factors. PMID:1153408

Honn, K V; Singley, J A; Chavin, W

1975-06-01

158

Interactions in the Serum  

Center for Drug Evaluation (CDER)

... Interactions in the Serum. Protein “bumping” interactions in the serum are a test-tube phenomenon without clinical relevance. ... More results from www.fda.gov/drugs/developmentapprovalprocess/developmentresources

159

SERUM CHANGES FOLLOWING THYROPARATHYROIDECTOMY  

PubMed Central

1. In thyroparathyroidectomized dogs the onset of tetany bears no constant relation to the ferment-antiferment balance of the serum. 2. The serum lipase titer remains at a low level throughout. 3. A progressive increase in non-coagulable nitrogen and proteoses is observed in the serum following the removal of the glands. 4. The amino nitrogen of the serum is usually increased at the time when tetany is most marked.

Petersen, William; Jobling, James W.; Eggstein, A. A.

1916-01-01

160

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

161

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.; Toma, Mitsuhiro [Research Inst. of Innovative Technology for the Earth, Tsukuba, Ibaraki (Japan). New Refrigerants Development Group

1999-04-01

162

Cell adhesion properties on chemically micropatterned boron-doped diamond surfaces.  

PubMed

The adhesion properties of living cells were investigated on a range of chemically modified boron-doped diamond (BDD) surfaces. We studied the influence of oxidized, H-, amine- (NH(2)-), methyl- (CH(3)-), trifluoromethyl- (CF(3)-) and vinyl- (CH(2)?CH-) terminated BDD surfaces on human osteosarcoma U2OS and mouse fibroblast L929 cells behavior. Cell-surface interactions were analyzed by fluorescence microscopy in terms of cell attachment, spreading and proliferation. U2OS cells poorly adhered on hydrophobic surfaces and their growth was blocked. In contrast, L929 cells were mainly influenced by the presence of perfluoroalkyl chains in regard to their morphology. The results were subsequently applied to selectively micropattern U2OS cells on dual hydrophobic/hydrophilic surfaces prepared by a UV/ozone lithographic approach. U2OS cells colonized preferentially hydrophilic (oxide-terminated) motifs, forming confluent arrays with distinguishable edges separating the alkyl regions. PMID:20715878

Marcon, Lionel; Spriet, Corentin; Coffinier, Yannick; Galopin, Elisabeth; Rosnoblet, Claire; Szunerits, Sabine; Héliot, Laurent; Angrand, Pierre-Olivier; Boukherroub, Rabah

2010-10-01

163

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

2012-11-21

164

Serum: Isoenzyme BB  

Microsoft Academic Search

We describe a sensitive, specific radioimmunoassay for the BB isoenzyme of creatine kinase (CK-BB) in serum. A sequential saturation assay was used to achieve sufficient sensitivity to detect the isoenzyme in l00-?tl serum sam- ples of all healthy persons and patients tested. Bound and free antigen were separatedby a second antibody system. Large excesses of purified isoenzyme MM didnot react

Mark H. Zweig; Andre C. Van Steirteghem; Alan N. Schechter

165

Irreversible Effects of Serum Proteins on Beta-Lactam Antibiotics  

PubMed Central

The chromogenic cephalosporin nitrocefin (87/312) demonstrates rapid and visible instability to serum from many species. This phenomenon was distinct from serum binding, being significantly slower. Destruction of another cephalosporin, 10485, by serum appeared to account for some anomalous results during investigation into its human pharmacokinetics. Many cephalosporins of very different structures also showed serum instability, unrelated to their degrees of serum binding as measured by plate assay. Extrapolation could not be made from one species to another with regard to either binding or instability. Small changes in the chemical structures of the 3- and 7-substituents of the cephalosporins made profound changes in their susceptibility to serum attack. The decomposition is pH dependent, occurring more slowly at acid pH, and is due to a high-molecular-weight component of serum that resists boiling for several minutes. Isoelectric focusing of serum from several animal species gave various species-specific bands that decomposed nitrocefin. The inactivation of nitrocefin was not entirely parallel with that of 10485 and was inhibited by it. All other ?-lactam compounds tested also inhibited the reaction, much greater concentrations usually being necessary when the inhibitor was stable to serum. The complex that causes breakdown of the ?-lactam compounds is not necessarily the same as the one causing serum binding. It is postulated that serum may affect most other ?-lactam antibiotics in a similar way, although in most cases, this only occurs to a very slight extent.

O'Callaghan, Cynthia H.

1978-01-01

166

SURFACE TENSION OF SERUM  

PubMed Central

Experiments are reported which indicate that a shift toward higher concentrations is observed in the minimum value of the static surface tension when plasma instead of serum solutions is used. The amount of the shift, expressed as a function of the concentration, shows that the figures are in satisfactory agreement with the determined amount of fibrinogen in the plasma. Some evidence is given that "plasma molecules" capable of organizing themselves on adsorbing surfaces exist in plasma, and that their length would be approximately 4.3 mµin round figures,instead of 4.0 mµ for the serum. The area occupied in the plane of adsorption by one individual molecule is, however, smaller than that occupied by the "serum molecule," thus indicating a marked structural difference between the two, the "plasma molecule" being narrower but longer than the "serum molecule." This difference may be due either to a different orientation accompanied by an increase in one of the dimensions, or else to an actual difference in structure with respect to the main axis, resulting in a decrease in the mean diameter of the "serum molecule" with an increase in the length of its main axis. The mass of the "plasma molecule" is about 6.3 per cent larger than that of the "serum molecule, " in the case of rabbit serum.

du Nouy, P. Lecomte

1927-01-01

167

Redox properties of serum albumin.  

PubMed

BACKGROUND: Oxidative damage results in protein modification, and is observed in numerous diseases. Human serum albumin (HSA), the most abundant circulating protein in the plasma, exerts important antioxidant activities against oxidative damage. SCOPE OF REVIEW: The present review focuses on the characterization of chemical changes in HSA that are induced by oxidative damage, their relevance to human pathology and the most recent advances in clinical applications. MAJOR CONCLUSIONS: The antioxidant properties of HSA are largely dependent on Cys34 and its contribution to the maintenance of intravascular homeostasis, including protecting the vascular endothelium under disease conditions related to oxidative stress. Recent studies also evaluated the susceptibility of other important amino acid residues to free radicals. The findings suggest that a redox change in HSA is related to the oxidation of several amino acid residues by different oxidants. Further, Cys34 adducts, such as S-nitrosylated and S-guanylated forms also play an important role in clinical applications. On the other hand, the ratio of the oxidized form to the normal form of albumin (HMA/HNA), which is a function of the redox states of Cys34, could serve as a useful marker for evaluating systemic redox states, which would be useful for the evaluation of disease progression and therapeutic efficacy. GENERAL SIGNIFICANCE: This review provides new insights into our current understanding of the mechanism of HSA oxidation, based on in vitro and in vivo studies. This article is part of a Special Issue entitled Serum Albumin. PMID:23644037

Anraku, Makoto; Chuang, Victor Tuan Giam; Maruyama, Toru; Otagiri, Masaki

2013-05-01

168

Developmental Neurotoxicity of Perfluorinated Chemicals Modeled in Vitro  

PubMed Central

Background The widespread detection of perfluoroalkyl acids and their derivatives in wildlife and humans, and their entry into the immature brain, raise increasing concern about whether these agents might be developmental neurotoxicants. Objectives We evaluated perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorooctane sulfonamide (PFOSA), and perfluorobutane sulfonate (PFBS) in undifferentiated and differentiating PC12 cells, a neuronotypic line used to characterize neurotoxicity. Methods We assessed inhibition of DNA synthesis, deficits in cell numbers and growth, oxidative stress, reduced cell viability, and shifts in differentiation toward or away from the dopamine (DA) and acetylcholine (ACh) neurotransmitter phenotypes. Results In general, the rank order of adverse effects was PFOSA > PFOS > PFBS ? PFOA. However, superimposed on this scheme, the various agents differed in their underlying mechanisms and specific outcomes. Notably, PFOS promoted differentiation into the ACh phenotype at the expense of the DA phenotype, PFBS suppressed differentiation of both phenotypes, PFOSA enhanced differentiation of both, and PFOA had little or no effect on phenotypic specification. Conclusions These findings indicate that all perfluorinated chemicals are not the same in their impact on neurodevelopment and that it is unlikely that there is one simple, shared mechanism by which they all produce their effects. Our results reinforce the potential for in vitro models to aid in the rapid and cost-effective screening for comparative effects among different chemicals in the same class and in relation to known developmental neurotoxicants.

Slotkin, Theodore A.; MacKillop, Emiko A.; Melnick, Ronald L.; Thayer, Kristina A.; Seidler, Frederic J.

2008-01-01

169

SERUM IMMUNOGLOBULIN IN SCABIES  

Microsoft Academic Search

Serum immunoglobulin levels were measured in 100 patients with scabies. White cell counts and erythrocyte sedimentation rates were measured in 62 of these patients and were normal in 59. The patients were divided into two groups according to whether their symptoms had been present for more or less than 3 weeks. The values for IgA were significantly lower in both

B. W. Hancock; A. Milford Ward

1974-01-01

170

Chemical Changes  

NSDL National Science Digital Library

In this activity you will learn what a chemical change is. The first step to understanding chemical changes is to recognize the difference between chemical properties and physical properties. Click here for an example: Chemical and Physical Changes What are the signs of a chemical reaction occuring? Signs of Chemical Change What variables affect a chemical reaction? Variables ...

Jolley, Mr.

2005-10-25

171

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

172

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.

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

173

The human serum metabolome.  

PubMed

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

2011-02-16

174

Quantitative serum immunoglobulin tests.  

PubMed

What is the test? Immunoglobulins are protein molecules. They contain antibody activity and are produced by the terminal cells of B-cell differentiation known as 'plasma cells'. There are five classes of immunoglobulin (Ig): IgG, IgM, IgA, IgD and IgE. In normal serum, about 80% is IgG, 15% is IgA, 5% is IgM, 0.2% is IgD and a trace is IgE. Quantitative serum immunoglobulin tests are used to detect abnormal levels of the three major classes (IgG, IgA and IgM). Testing is used to help diagnose various conditions and diseases that affect the levels of one or more of these immunoglobulin classes. Some conditions cause excess levels, some cause deficiencies, and others cause a combination of increased and decreased levels. IgD and IgE will not be discussed in this article. PMID:23550242

Loh, Richard K S; Vale, Sandra; McLean-Tooke, Andrew

2013-04-01

175

Serum and tumour ferritins in primary liver cancer.  

PubMed Central

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 non-tumorous liver. There was, however, a negative correlation between serum ferritin and alpha-foetoprotein concentrations. Ferritin was purified from PLC tissue obtained from three patients at necropsy and the distribution of isoferritins was determined by isoelectric focusing. Acidic isoferritins similar to those previously found in PLC tissue were obtained. Their acidic nature was confirmed chromatographically using DEAE cellulose. Because the serum ferritin in patients with PLC probably consists of a mixture of normal and acidic isoferritins, it is likely that the serum assay used in the present study underestimated the actual concentrations present. With the development of an assay which utlises a specific antibody against acidic PLC isoferritins, serum ferritin may prove to be a second marker for PLC.

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

1978-01-01

176

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.

D'eon, Jessica C.; Mabury, Scott A.

2011-01-01

177

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

178

Effect of a standardized wheat bran preparation on serum lipids in young  

Microsoft Academic Search

Feeding of a chemically standardized coarse wheat bran product in a dose of 0.5 g\\/kg body weight per day over a period of 4 weeks in young healthy male volunteers did cause a significant reduction in total serum cholesterol as well as in total serum triglycerides of 10 and 24%, respectively. Very low density lipoprotein-, high density lipoprotein-, and low

G. P. van Berge-Henegouwen; A. W. Huybregts; S. van de Werf

179

Operation of a DNA-Based Autocatalytic Network in Serum  

NASA Astrophysics Data System (ADS)

The potential for inferring the presence of cancer by the detection of miRNA in human blood has motivated research into the design and operation of DNA-based chemical amplifiers that can operate in bodily fluids. As a first step toward this goal, we have tested the operation of a DNA-based autocatalytic network in human serum and mouse serum. With the addition of sodium dodecyl sulfate to prevent degradation by nuclease activity, the network was found to operate successfully with both DNA and RNA catalysts.

Graugnard, Elton; Cox, Amber; Lee, Jeunghoon; Jorcyk, Cheryl; Yurke, Bernard; Hughes, William L.

180

Analysis of glycans on serum proteins using antibody microarrays  

PubMed Central

Antibody arrays can be employed for the profiling glycan structures on proteins. Antibody arrays capture multiple, specific proteins directly from biological samples (such as serum), and lectin and glycan-binding antibodies probe the levels of specific glycans on the captured proteins. We use a practical method of partitioning microscope slides to enable the convenient processing of many detection reagents or samples. A critical first step in the procedure is the chemical derivatization of the glycans on the spotted capture antibodies, which prevents lectin binding to those glycans. We describe those methods along with the methods for preparing and treating serum samples, running the experiments, and designing and interpreting the experiments.

Chen, Songming; Haab, Brian B.

2013-01-01

181

Elemental Analysis of Human Serum and Serum Protein Fractions by Thermal Neutron Activation.  

National Technical Information Service (NTIS)

Some acplications of thermal neutron activation for the determination of elemental contents in human serum and human serum protein fractions are presented. First total serum is dealt with; second serum protein fractions obtained by gel filtration are desc...

J. R. W. Woittiez

1984-01-01

182

Serum albumin alters the expression of iron-controlled genes in Pseudomonas aeruginosa  

PubMed Central

Pseudomonas aeruginosa, which causes serious infections in immunocompromised patients, produces numerous virulence factors, including exotoxin A and the siderophore pyoverdine. As production of these virulence factors is influenced by the host environment, we examined the effect serum has on global transcription within P. aeruginosa strain PAO1 at different phases of growth in an iron-deficient medium. At early exponential phase, serum significantly enhanced expression of 138 genes, most of which are repressed by iron, including pvdS, regA and the pyoverdine synthesis genes. However, serum did not interfere with the repression of these genes by iron. Serum enhanced regA expression in a fur mutant of PAO1 but not in a pvdS mutant. The serum iron-binding protein apotransferrin, but not ferritin, enhanced regA and pvdS expression. However, in PAO1 grown in a chemically defined medium that contains no iron, serum but not apotransferrin enhanced pvdS and regA expression. While complement inactivation failed to eliminate this effect, albumin absorption reduced the effect of serum on pvdS and regA expression in the iron-deficient medium chelexed tryptic soy broth dialysate. Additionally, albumin absorption eliminated the effect of serum on pvdS and regA expression in the chemically defined medium. These results suggest that serum enhances the expression of P. aeruginosa iron-controlled genes by two mechanisms: one through apotransferrin and another one through albumin.

Kruczek, Cassandra; Wachtel, Mitchell; Alabady, Magdy S.; Payton, Paxton R.; Colmer-Hamood, Jane A.

2012-01-01

183

Rapid Enzymatic Measurement of Serum Flucytosine Levels.  

National Technical Information Service (NTIS)

A method is provided for the rapid enzymatic determination of serum flucytosine or cytosine. The serum is first incubated with glutamate dehydrogenase to release endogenous ammonia which is measured, and the serum is then incubated with creatinine iminohy...

M. H. Kroll C. M. Huang R. G. Washburn

1987-01-01

184

SERUM LIPIDS IN ANXIETY NEUROSIS  

PubMed Central

SUMMARY Serum cholesterol, total triglycerides, HDL-cholesterol, LDL-cholesterol, VLDL-cholesterol, free cholesterol and total phospholipids were studied in 36 patients of anxiety neurosis and 24 control subjects. Serum triglycerides, VLDL-cholesterol and free-cholesterol were found to be significantly raised while esterified cholesterol WJS significantly lowered in anxiety neurosis. A significant negative correlation was observed between the anxiety score and free cholesterol in ferrule patients. The significance of these findings has been discussed.

Mishra, T.K.; Shankar, R.; Sharma, I.; Srivastava, P.K.

1984-01-01

185

Exercise alters serum pneumoprotein concentrations  

Microsoft Academic Search

To determine the effect of exercise on serum levels of Clara cell protein (CC16) and surfactant-associated protein A (SP-A), serum was collected from 14 healthy subjects 1 h after maximal and sub-maximal exercise. Healthy volunteers participated on separate occasions in a control (no exercise) session, simulated firefighting tasks for 30 min (n=14), and intermittent treadmill exercise at near maximal heart

Christopher J Nanson; Jefferey L Burgess; Marjorie Robin; Alfred M Bernard

2001-01-01

186

Serum Uric Acid in Smokers  

PubMed Central

Objectives To demonstrate the possible effect of smoking on serum uric acid. Methods Subjects enrolled in study were divided into two groups; nonsmokers and smokers, each with 60 male volunteers of the same social class and dietary habit without history of alcohol consumption, diabetes mellitus, hyperuricemia and gout, renal, joint, lung or heart diseases. Fasting blood and random urine samples were obtained from both groups for measurement of uric acid and creatinine. Calculation of both urine uric acid/urine creatinine ratio and fraction excretion of uric acid were done. The results were statistically evaluated by standard statistical methods. Results No significant differences in the age, serum creatinine, spot urine uric acid/urine creatinine ratio and fraction excretion of uric acid between the two groups, serum uric acid was significantly lower in smokers. In smokers there was significant negative correlation of smoking status (average number of cigarette smoked/day, duration of smoking and cumulative amount of smoking) with serum uric acid. Conclusion After exclusion of other factors affecting uric acid level, the significant low serum uric acid level in smokers was attributed to reduce endogenous production as a result of chronic exposure to cigarette smoke that is a significant source of oxidative stress. As this reduction is proportionate with smoking status and predisposes to cardiovascular disease, it is, therefore, recommended for smokers to stop or reduce smoking and introduce serum uric acid estimation as routine test since its cheap and simple to reflect their antioxidant level. Keywords Smokers; Uric acid; CVD.

Hanna, Bassam E.; Hamed, Jamal M.; Touhala, Luma M.

2008-01-01

187

Kinetics of DNA and RNA Hybridization in Serum and Serum-SDS  

PubMed Central

Cancer is recognized as a serious health challenge both in the United States and throughout the world. While early detection and diagnosis of cancer leads to decreased mortality rates, current screening methods require significant time and costly equipment. Recently, increased levels of certain micro-ribonucleic acids (miRNAs) in the blood have been linked to the presence of cancer. While blood-based biomarkers have been used for years in cancer detection, studies analyzing trace amounts of miRNAs in blood and serum samples are just beginning. Recent developments in deoxyribonucleic acid (DNA) nanotechnology and DNA computing have shown that it is possible to construct nucleic-acid-based chemical networks that accept miRNAs as inputs, perform Boolean logic functions on those inputs, and generate as an output a large number of DNA strands that can readily be detected. Since miRNAs occur in blood in low abundance, these networks would allow for amplification without using polymerase chain reaction. In this study, we report initial progress in the development of a DNA-based cross-catalytic network engineered to amplify specific cancer-related miRNAs. Subcomponents of the DNA network were tested individually, and their operation in serum, as well as a mixture of serum with sodium dodecyl sulfate, is demonstrated. Preliminary simulations of the full cross-catalytic network indicate successful operation.

Graugnard, Elton; Cox, Amber; Lee, Jeunghoon; Jorcyk, Cheryl; Yurke, Bernard; Hughes, William L.

2010-01-01

188

Chemical Biology\\/ Chemical Genetics\\/ Chemical Genomics: Importance of Chemical Library  

Microsoft Academic Search

A new field of science, chemical biology\\/ chemical genetics\\/ chemical genomics (cb\\/cg\\/cg) has emerged since the late 1990's, especially in the United States. The NIH Roadmap agenda, Molecular Libraries Screening Center Network (MLSCN), became a drive force to push cb\\/cg\\/cg forward. Cb\\/cg\\/cg studies consist of three methodologies, chemical libraries with small molecules, high-throughput screenings, and computational databases. In this review,

Fumihiko Kugawa; Masaru Watanabe; Fuyuhiko Tamanoi

2007-01-01

189

Perfluorinated chemicals in relation to other persistent organic pollutants in human blood.  

PubMed

In order to evaluate blood levels of some perfluorinated chemicals (PFCs) and compare them to current levels of classical persistent organic pollutants (POPs) whole blood samples from Sweden were analyzed with respect to 12 PFCs, 37 polychlorinated biphenyls (PCBs), p,p'-dichlorodiphenyl-dichloroethylene (DDE), hexachlorobenzene (HCB), six chlordanes and three polybrominated diphenyl ethers (PBDEs). The median concentration, on whole blood basis, of the sum of PFCs was 20-50 times higher compared to the sum of PCBs and p,p'-DDE, 300-450 times higher than HCB, sum of chlordanes and sum of PBDEs. Estimations of the total body amount of PFCs and lipophilic POPs point at similar body burdens. While levels of for example PCBs and PBDEs are normalized to the lipid content of blood, there is no such general procedure for PFCs in blood. The distributions of a number of perfluorinated compounds between whole blood and plasma were therefore studied. Plasma concentrations were higher than whole blood concentrations for four perfluoroalkylated acids with plasma/whole blood ratios between 1.1 and 1.4, whereas the ratio for perflurooctanesulfonamide (PFOSA) was considerably lower (0.2). This suggests that the comparison of levels of PFCs determined in plasma with levels determined in whole blood should be made with caution. We also conclude that Swedish residents are exposed to a large number of PFCs to the same extent as in USA, Japan, Colombia and the few other countries from which data is available today. PMID:16403420

Kärrman, Anna; van Bavel, Bert; Järnberg, Ulf; Hardell, Lennart; Lindström, Gunilla

2006-01-03

190

Serum Fluoride and Sialic Acid Levels in Osteosarcoma  

Microsoft Academic Search

Osteosarcoma is a rare malignant bone tumor most commonly occurring in children and young adults presenting with painful swelling.\\u000a Various etiological factors for osteosarcoma are ionizing radiation, family history of bone disorders and cancer, chemicals\\u000a (fluoride, beryllium, and vinyl chloride), and viruses. Status of fluoride levels in serum of osteosarcoma is still not clear.\\u000a Recent reports have indicated that there

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

191

Serum markers of cutaneous melanoma.  

PubMed

Malignant melanoma currently accounts for approximately 1%, of all cancer deaths. The incidence of cutaneous melanoma is rising worldwide. The treatment of early-stage melanoma consists primarily of surgical removal of the tumour. The overall 5-years survival rate for malignant melanoma is 81%. Recently, many efforts have been made to analyse the potential significance and the possible relationship of disease progression and circulating markers in malignant melanoma. Several serum biomarkers appear to hold significant potential both as prognostic indicators and as targets for future therapeutic agents. The application of these markers in clinical practice possibly holds the key to significant advances in melanoma. This review summarizes the principal characteristics of serum markers of melanoma. Serum lactate dehydrogenase (ldh), protein S-100 beta, melanoma-inhibiting activity (MIA) may correlate with melanoma progression. Tenascin-c, Hyaluronan, Laminin-1 and type VI Collagen are involved in melanoma development and extracellular matrix remodelling during melanoma progression. PMID:20515782

Perrotta, Rosario; Bevelacqua, Ylenia; Malaguarnera, Giulia; Paladina, Isabella; Giordano, Maria; Malaguarnera, Mariano

2010-06-01

192

[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

193

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

194

Specific antioxidant properties of human serum albumin.  

PubMed

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

Taverna, Myriam; Marie, Anne-Lise; Mira, Jean-Paul; Guidet, Bertrand

2013-02-15

195

Chemical microsensors  

DOEpatents

An article of manufacture is provided including a substrate having an oxide surface layer and a selective thin film of a cyclodextrin derivative chemically bound upon said substrate, said film is adapted for the inclusion of a selected organic compound therewith. Such an article can be either a chemical sensor capable of detecting a resultant mass change from inclusion of the selected organic compound or a chemical separator capable of reversibly selectively separating a selected organic compound.

Li, DeQuan (Los Alamos, NM); Swanson, Basil I. (Los Alamos, NM)

1995-01-01

196

Chemical Bonds  

NSDL National Science Digital Library

Electrons are key to forming the two broad categories of chemical bonds: covalent and ionic. Atoms, which have a nucleus surrounded by electrons, are represented in several different ways. In the Chemical Bonds activity, students explore the different kinds of chemical bonds that can form, ranging from non-polar covalent to ionic. In the model depicted above students adjust the electronegativity of two atoms and see the effect it has on electron distribution and bond type.

Consortium, The C.

2011-12-11

197

Serum Levels of Pigmentation Markers Are Elevated in Patients Undergoing Hemodialysis  

Microsoft Academic Search

Background: Diffuse hyperpigmentation is common among patients with chronic renal failure undergoing hemodialysis (HD). We have examined serum levels of 5-S-cysteinyldopa (5SCD, a pheomelanin precursor), pheomelanin, eumelanin, and protein-bound (PB-) 3,4-dihydroxyphenylalanine (DOPA) and PB-5SCD in HD patients. Methods: Pheomelanin and eumelanin were assayed by chemical degradation methods. Results: Serum levels of free 5SCD in HD patients (n = 16) were

Kazutaka Murakami; Kazumasa Wakamatsu; Yukiko Nakanishi; Hiroki Takahashi; Satoshi Sugiyama; Shosuke Ito

2007-01-01

198

Thioflavin T fluorescence in human serum: Correlations with vascular health and cardiovascular risk factors  

Microsoft Academic Search

Objectives:Amyloid fibrils and amyloid-like structures are implicated in atherosclerosis via macrophage activation and inflammation. A common property of amyloid-like structures is their ability to induce thioflavin T (ThT) fluorescence. We measured ThT fluorescence in serum and related these levels to traditional cardiovascular risk factors and non-invasive measures of vascular dysfunction (elasticity). In addition, chemically modified serum components that contribute to

Michael D. W. Griffin; Leanne M. Wilson; Yee-Foong Mok; Andrzej S. Januszewski; Andrew M. Wilson; Connie S. Karschimkus; Evange Romas; Allan B. Lee; Tim Godfrey; Melinda Wong; Laurence Clemens; Alicia J. Jenkins; Geoffrey J. Howlett

2010-01-01

199

Serum total testosterone:immunoassay compared with negativechemicalionizationgas chromatography-massspectrometry  

Microsoft Academic Search

We have developed an electron capture negative chemical ionization gas chromatography-mass spectrometry (GC- MS) procedure to quantify serum testosterone in the clin- ically relevant range 0.69-69.3 nmol\\/L and used this pro- cedure to assess Ciba Corning Diagnostics ACS:180#{174} testosterone inununoassay. The GC-MS method involves liquid-liquid extraction of serum samples and synthesis of a pentafluorobenzyloxime\\/silyl ether derivative of testoster- one with

ROBERT L. FITZGERALD; DAVID A. HEROLD

200

Affinity of Animal Cell Nucleoli for Normal Serum. Preliminary Characterization of Serum and Cell Components.  

National Technical Information Service (NTIS)

Nucleoli of animal cells cultured in vitro are modified by a component of 'nonimmune' animal serum. Modified nucleoli bind fluorescein-conjugated nonimmune serum proteins, as shown by calcium ion-dependent fluorescence. Analysis of serum indicates that th...

J. C. Maisel R. I. Lytle

1965-01-01

201

Application of Tryptophan Fluorescence to Assess Sensitizing Potentials of Chemicals  

Microsoft Academic Search

There are too many chemical substances around our living space. However, the toxicity of most of them has not been reported,\\u000a especially regarding their sensitizing potentials. We aimed to develop a simple in vitro method to quantitatively predict\\u000a the sensitizing potentials of chemicals by measuring the fluorescence of chemical-human serum albumin (HSA) complexes. HSA\\u000a was treated with test chemicals and

Thi-Thu-Phuong Pham; Tsunehiro Oyama; Toyohi Isse; Toshihiro Kawamoto

2009-01-01

202

Heterotoxicity of Human Serum V  

Microsoft Academic Search

Intravenous injections of fresh human serum (FHS) with an operative alternative complement pathway (ACP) were toxic for mice. The toxic reaction was manifested by intravascular hemolysis, hemoglobinuria, and a slight prolongation in the mean activated thromboplastin time, prothrombin time and thrombin time. In moribund animals, this was followed by a profound thrombocytopenia and alterations in the leukocyte counts. Marked to

E. Rozenfarb; D. Eidinger

1979-01-01

203

NEPHROTOXIC SERUM NEPHRITIS IN RATS  

PubMed Central

Studies have been carried out to determine the distribution of antigen capable of inducing the formation in rabbits of antibodies nephrotoxic for the rat. The results indicate that the antigen is present both in cortex and medulla of rat kidney. It can be extracted to a limited extent with saline. It is non-dialyzable and destroyed by boiling. The nephrotoxic serum antigen is also present in rat lung and placenta, in amounts roughly comparable to that in kidney, and in a number of other rat organs in smaller amounts. These various tissues not only are capable of stimulating the production of nephrotoxic antibodies, but each tissue is also able to absorb the nephrotoxic antibodies induced by injections of other rat tissues. These studies indicate that the nephrotoxic serum antigen in various rat tissues is the same or closely related. The nephrotoxic serum antigen of the rat is distinct from that of the dog and the rabbit, but there appears to be a cross-reaction between the nephrotoxic serum antigens of the rat and mouse. It is concluded that the nephrotoxic serum antigen is not a specific component of kidney; it is neither limited to kidney in its distribution within the rat, nor is the rat antigen present in kidney tissue of 2 other species examined. Rather, it is probable that the antigen is to a large extent specific for tissue of a given species. The preponderance of renal injury following injections of the anti-organ sera presumably is due to the occurrence in the kidney of large amounts of the antigen in positions of physiological importance in which it is exposed directly to the circulating antibodies.

Baxter, James H.; Goodman, Howard C.

1956-01-01

204

Chemical agents and chemical terrorism.  

PubMed

Chemical terrorism is a new threat to the security of mankind, which scale essentially exceeds the impact of use of the most modem firearms. At present time all over the world threats from different radical elements to use radioactive materials, potent poisonous substances and pathogenic microorganisms for terrorist purposes became more frequent. High-toxic chemical substances can fall in terrorist hands through wide range of sources. Potentially misused types of chemical compounds are discussed in this article. PMID:15141987

Patocka, J; Fusek, J

2004-03-01

205

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

206

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

207

Chemical spectroscopy  

Microsoft Academic Search

The purpose of chemical spectroscopy with neutrons is to utilize the dependence of neutron scattering cross sections on isotope and on momentum transfer (which probes the spatial extent of the excitation) to understand fundamental and applied aspects of the dynamics of molecules and fluids. Chemical spectroscopy is divided into three energy ranges: vibrational spectroscopy, 25-500 MeV, for which much of

J. Eckert; T. O. Brun; A. J. Dianoux; J. Howard; J. J. Rush; J. W. White

1984-01-01

208

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

209

Chemical Composition  

Microsoft Academic Search

Measurements of the chemical compositions of materials and the levels of certain substances in them are vital when assessing and improving public health, safety and the environment, are necessary to ensure trade equity, and are required when monitoring and improving industrial products and services. Chemical measurements play a crucial role in most areas of the economy, including healthcare, food and

Willie May; Richard Cavanagh; Gregory Turk; Michael Winchester; John Travis; Melody Smith; Paul Derose; Steven Choquette; Gary Kramer; John Sieber; Robert Greenberg; Richard Lindstrom; George Lamaze; Rolf Zeisler; Michele Schantz; Karen Phinney; Michael Welch; Thomas Vetter; Kenneth Pratt; John Scott; John Small; Scott Wight; Stephan Stranick

2006-01-01

210

Chemical Name  

Cancer.gov

Attachment III Chemical Quick Reference Chart for Minors Chemical Name Select Carcinogen Reproductive Toxin LD50 < 50 mg/kg (oral rat) LD50 < 200 mg/kg for 24 hours or less (dermal rabbit) LC50 < 200 ppm or 2 mg/L for one hour (inhalation rat)

211

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

212

Syntheses with perfluoroalkyl iodides. A review  

Microsoft Academic Search

RFI reacts with the endo cis dialkyl norbornene esters to give adducts in 95–100% yield; the RF radical adds to an exo position and RFI transfers iodine to an adjacent exo position. By contrast, RF adds exo and RFI transfers iodine endo to the endo- or exo-norbornenedicarboxylic anhydrides (Schemes 1–3). Exo-6-iodo ester 5a or 6a, when heated, eliminates RI and

Neal O. Brace

2001-01-01

213

Characterization of chick serum lipoproteins isolated by density gradient ultracentrifugation.  

PubMed

Serum lipoproteins from 12h fasted male chicks (15-day-old) were separated into 20 fractions by isopycnic density gradient ultracentrifugation. A new procedure was described by collecting the different fractions from the bottom of tube instead of by aspiration from the meniscus of each tube. Analyses of chemical composition of serum lipoproteins have permitted to reevaluate the density limits of major classes: VHDL, d greater than 1.132 g/ml; HDL, d 1.132-1.084 g/ml; LDL, d 1.084-1.038; IDL, d 1.038-1.022; and VLDL d less than 1.022. HDL fractions clearly predominated (approx. 77% of total lipoproteins) while IDL and VLDL were present at low percentage. LDL was the fraction richest in cholesterol; triacylglycerol content clearly increased from HDL to VLDL, while protein content decreased. All the chemical components of chick serum lipoproteins were accumulated in HDL, although triacylglycerol was relatively distributed in all the lipoprotein classes. PMID:1380327

Rodriguez-Vico, F; Lopez, J M; Castillo, M; Zafra, M F; Garcia-Peregrin, E

214

Immunochemical Study of Bovine Serum Proteins.  

National Technical Information Service (NTIS)

With the aid of immunological methods of analysis, this study characterizes certain protein fractions of the blood serum of cattle. Analyses indicate that serum proteins differ not only in their electrophoretic mobility, but also in their antigenic struct...

V. M. Kholod

1975-01-01

215

Serum Lipoprotein Patterns in Liver Disease (34886).  

National Technical Information Service (NTIS)

An agarose gel electrophoretic technique which clearly detects and sharply resolves serum lipoproteins has been applied to the determination of serum lipoprotein patterns in liver diseases. The patterns obtained are characterized by presence of beta-, abs...

M. A. Charles N. M. Papadopoulos

1970-01-01

216

Serum and urine ionic fluoride  

Microsoft Academic Search

The present study was undertaken to evaluate the fluoride status in the general healthy population of Barcelona. Serum and\\u000a urine fluoride ionic concentration was determined in a random sample of 250 subjects (age range 15–90 yr) by the Orion fluoride\\u000a electrode system to determine the normal range of fluoride in this population. The results obtained show that in the general

M. Torra; M. Rodamilans; J. Corbella

1998-01-01

217

Chemical Agents  

Center for Drug Evaluation (CDER)

... FDA has cleared for use by the US military a liquid decontamination lotion intended to remove or neutralize chemical warfare agents and T-2 fungal ... More results from www.fda.gov/drugs/emergencypreparedness/bioterrorismanddrugpreparedness

218

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

219

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

220

Chemical Emergency  

MedlinePLUS

... Prepare Your Workplace Types of Emergency Chemical Emergency Drought Preparedness Earthquake Home Fire Flood Flu Food Safety ... you have been advised by medical professionals. Next Drought Preparedness & Water Conservation Be Red Cross Ready Are ...

221

Chemical Kinetics  

Microsoft Academic Search

\\u000a While thermodynamics provides steady-state information of the combustion process, chemical kinetics describes the transient\\u000a states of the system during the combustion process. Particularly important is information related to the rate at which species\\u000a are consumed and produced, and the rate at which the heat is released. Combustion chemistry has two important characteristics\\u000a not commonly observed in other chemical systems. First,

Sara McAllister; Jyh-Yuan Chen; A. Carlos Fernandez-Pello

222

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

223

Effect of different doses of chlorthalidone on blood pressure, serum potassium, and serum urate  

Microsoft Academic Search

Chlorthalidone given to 40 hypertensive women significantly decreased blood pressure and serum potassium levels and increased the serum urate concentration. There were no individual correlations between the reduction in blood pressure and the decrease in serum potassium or the increase in serum urate. A reduction in dosage from 50 mg daily to 50 mg three times a week produced no

C Bengtsson; G Johnsson; R Sannerstedt; L Werkö

1975-01-01

224

Predictors of Serum Dioxins and PCBs among Peripubertal Russian Boys  

PubMed Central

Background Although sources and routes of exposure to dioxins and polychlorinated biphenyls (PCBs) have been studied, information regarding exposure among children is limited. Breast-feeding and diet are two important contributors to early life exposure. To further understand other significant contributors to childhood exposure, we studied a cohort of children from a city with high environmental dioxin levels. Objectives We investigated predictors of serum concentrations of polychlorinated dibenzo-p-dioxins (PCDDs)/polychlorinated dibenzofurans (PCDFs)/co-planar PCBs (C-PCBs), toxic equivalents (TEQs), and PCBs among 8- to 9-year-old boys in Chapaevsk, Russia. Methods We used general linear regression models to explore associations of log10-transformed serum concentrations of PCDDs/PCDFs/C-PCBs, TEQs, and PCBs at study entry with anthropometric, demographic, geographic, and dietary factors in 482 boys in Chapaevsk, Russia. Results The median (25th, 75th percentile) concentration for total 2005 TEQs was 21.1 pg/g lipid (14.4, 33.2). Boys who were older, consumed local foods, were breast-fed longer, and whose mothers were employed at the Khimprom chemical plant (where chlorinated chemicals were produced) or gardened locally had significantly higher serum dioxins and PCBs, whereas boys with higher body mass index or more educated parents had significantly lower serum dioxins and PCBs. Boys who lived < 2 km from Khimprom had higher total TEQs (picograms per gram lipid) [adjusted mean = 30.6; 95% confidence interval (CI), 26.8–35.0] than boys who lived > 5 km away (adjusted mean = 18.8; 95% CI, 17.2–20.6). Conclusions Our findings suggest that there are specific local sources of dioxin and PCB exposure among children in Chapaevsk including maternal gardening, consumption of locally grown food, and residential proximity to the Khimprom plant.

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

2009-01-01

225

Chemical Warfare and Chemical Disarmament.  

ERIC Educational Resources Information Center

|Described are some of the technical, military, and political considerations that bear most directly on the choices facing the United States and its NATO allies on modern lethal chemical weapons. (BT)|

Meselson, Matthew; Robinson, Julian Perry

1980-01-01

226

Host and environmental determinants of polychlorinated aromatic hydrocarbons in serum of adolescents.  

PubMed Central

This study investigated host factors and environmental factors as potential determinants of polychlorinated aromatic hydrocarbons (PCAHs) in serum of adolescents. We recruited 200 participants (80 boys and 120 girls), with a mean age of 17.4 years (SD, 0.8), in Belgium from a rural control area (Peer) and from two polluted suburbs of Antwerp where a nonferrous smelter (Hoboken) and waste incinerators (Wilrijk) are located. We quantified polychlorinated biphenyls (PCBs; congeners 138, 153, and 180) in serum by gas chromatography and obtained the toxic equivalents (TEQs) of PCAHs in serum with the chemically activated luciferase gene expression bioassay (CALUX). Serum PCB concentration was higher in boys than in girls (1.67 vs. 1.02 nmol/L or 377 vs. 210 pmol/g serum lipids; p< 0.001). In the whole adolescent group, multiple regression showed that serum PCB concentration decreased 0.06 nmol/L per 1% increase in body fat content (p< 0.001) and increased 0.39 nmol/L and 0.14 nmol/L per 1 mmol/L increase in serum concentrations of triglycerides (p < 0.001) and cholesterol (p = 0.002), respectively. Host factors explained 44% of the serum PCB variance. In the same model, serum PCB concentration increased 0.14 nmol/L with 10 weeks of breast-feeding (p< 0.001) and 0.06 nmol/L with intake of 10 g animal fat per day (p < 0.001), and was associated with residence in the waste incinerator area (9% higher; p = 0.04); 11% of the variance could be explained by these environmental factors. The geometric mean of the serum TEQ value was similar in boys and girls (0.15 TEQ ng/L or 33.0 pg/g serum lipids). In multiple regression, TEQ in serum decreased 0.03 ng/L per centimeter increase in triceps skinfold (p = 0.006) and was 29% higher in subjects living close to the nonferrous smelter (p < 0.001). This study showed that in 16- to 18-year-old teenagers host factors are important determinants of serum concentrations of PCAHs, whereas environmentally related determinants may to some extent contribute independently to human exposure to these persistent chemicals in the environment.

Nawrot, Tim S; Staessen, Jan A; Den Hond, Elly M; Koppen, Gudrun; Schoeters, Greet; Fagard, Robert; Thijs, Lutgarde; Winneke, Gerhard; Roels, Harry A

2002-01-01

227

[Modification of placenta blood serum proteins under low temperature effect].  

PubMed

Changes in environmental physical and chemical factors upon freeze-thawing and low temperature storage of biological samples can result in impairments of protein structures. This work specifies spontaneous and diamide-induced protein aggregations of placenta blood serum stored at -20 degrees and -196 degrees C during 2 years with SDS-PAGE. It was shown that storage of placenta blood serum at low temperatures did not cause any quantitative and qualitative changes in fraction distribution of proteins denatured with SDS in comparison to the native samples which were not frozen. Application of beta-mercaptoethanol revealed that placenta blood serum proteins upon freeze-thawing did not form spontaneous aggregates linked by disulphide bridges. Oxidation of amino acid sulfhydryl groups induced by diamide and accompanied by high molecular aggregate formation proved to be a quite effective way for indirect estimation of structural changes in protein upon low temperature effects. In samples thawed after low temperature storage the protein aggregation with 4 microM diamide was significantly higher than in native serum. These discrepancies between native and frozen-thawed samples are stipulated by impairments of protein structure under low temperature and increased in accessibility of reactive SH-groups of proteins for oxidation with diamide. Structural changes in placenta blood serum proteins, which caused by low temperatures and revealed by elevated sensibility to diamide-induced aggregate formation, did not depend on temperature (-20 degrees and -196 degrees C) and storage terms (2 years and 3 weeks). They reflect protein reaction to freeze-thawing processes and could be sequence of ice crystal formation which takes place in unprotected media. PMID:23789348

Fal'ko, O V; Zemlianskikh, N G; Lipina, O V; Prokopiuk, O S

228

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

229

Assay of the Antibiotic Activity of Serum  

PubMed Central

One of the drawbacks of the “tube dilution” method for the assay of antibiotics in human serum has been illustrated by utilizing serum-sensitive and serum-resistant strains of Escherichia coli. In the case of serum-sensitive strains, it was found that fresh serum alone may account for the same degree of inhibition and thus yield minimal inhibitory concentrations identical to those obtained with serum combined with antibiotics, that is, “simulated” serum assay specimens. This fallacy of the method is discussed with regard to those instances in which laboratories were merely to utilize the patient's own coliform organism as the test organism, or with respect to the assay of, for example, polymyxins, in which inadvertently a R(ough) and therefore, serum-sensitive strain of E. coli were to be used as the indicator organism. It is recommended that serum-resistant laboratory strains of Staphylococcus aureus or E. coli of known antibiotic susceptibility be employed as the test organisms proper in order to circumvent the inherent bactericidal activity of serum.

Traub, Walter H.

1969-01-01

230

Chemical sensors  

SciTech Connect

This review of chemical sensors contains the following topics of interest: books and reviews; reviews of sensors by their type; fabrication and selectivity; data processing; thermal sensors; mass sensors (fabrication, gas sensors, and liquid sensors); electrochemical sensors (potentiometric sensors, amperometric sensors, and conductometric sensors); and optical sensors (fabrication, liquid sensors, biosensors, and gas sensors). 795 refs., 1 tab.

Janata, J.; Josowicz, M.; DeVaney, D.M. (Pacific Northwest Lab., Richland, WA (United States))

1994-06-15

231

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…

Barry, Dana M.

232

Chemical Ionization  

Microsoft Academic Search

\\u000a Mass spectrometrists have ever been searching for ionization methods softer than EI, because molecular weight determination\\u000a is key for structure elucidation. Chemical ionization (CI) is the first of the so-called soft ionization methods we are going to discuss (cf. Fig. 1.2).

Jürgen H. Gross; Mass Spectrometry

233

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

234

Chemical Indicators.  

ERIC Educational Resources Information Center

|This science sourcebook was written for intermediate grade teachers to provide guidance in teaching a specially developed unit on chemical indicators. Directions and suggestions for guiding student science activities are given. Some of the activities concern soil testing, crystals, and household powders such as sugar and salt. A list of necessary…

Prombain, Dorothy R.; And Others

235

III. SERUM CALCIUM OF INDIVIDUAL ANIMALS DURING DEVELOPMENT OF CALCIUM DEFICIENCY l  

Microsoft Academic Search

The results of a study of the symptoms, the pathology, and the changes in chemical composition of rats suffering from uncomplicated, severe, calcium deficiency have recently been published by Boelter and Greenberg ('41). It was demon strated, in the course of this study, that a marked reduction in the serum calcium concentration occurred. To demonstrate this fact it was necessary

DAVID M. GREENBEBG; WILBUR DOANE MILLER

236

Serum Aluminum Transport and Aluminum Uptake in Chronic Renal Failure: Role of Iron and Aluminum Metabolism  

Microsoft Academic Search

Several factors have been blamed for increasing gastrointestinal absorption of aluminum. The likely role of iron metabolism was suggested some years ago. As iron and aluminum share many chemical properties, it is reasonable to think they also share biological pathways. The aim of this study was: (a) to evaluate serum aluminum transport and its relationship with iron-binding capacity, and (b)

Jorge B. Cannata; Ines R. Olaizola; Carlos Gomez-Alonso; Pilar Menéndez-Fraga; Mario Alonso-Suarez; Bernardino Diaz-Lopez

1993-01-01

237

Tracking the development of serum biochemical parameters in two laying hen strains - a comparative study  

Microsoft Academic Search

A follow-up, comparative study was designed for the description of differences between two divergent laying hen strains, a Leghorn type and a medium heavy body (MHB) genotype (Hy-Line Brown), in chemical body composition and serum biochemical parameters determined at 3, 4, 6, 8, 10, 12, 14, 18, 20, 25, 30, 52 and 72 weeks of age; each time 5 birds

AGROKOMPLEX C. S. RT; JÓZSEF GYENIS; ROBERT ROMVÁRI; PETER HORN

2006-01-01

238

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.

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

2010-01-01

239

International Reference Preparation of Rheumatoid Arthritis Serum  

PubMed Central

The National Institute for Medical Research, London, England, was requested by the WHO Expert Committee on Biological Standardization to arrange a collaborative study of the serum pool they had obtained, to determine its suitability to serve as an international reference preparation of rheumatoid arthritis serum. A batch of this serum was assayed by 11 laboratories in 7 countries against 30 test preparations. On the basis of the results obtained, the serum has been established as the International Reference Preparation of Rheumatoid Arthritis Serum and the International Unit of Rheumatoid Arthritis Serum has been defined as the activity contained in 0.171 mg of the international reference preparation. A description is also given of the British reference preparation of rabbit antibody to sheep red blood cells (amboceptor) and this material was also tested in the collaborative study.

Anderson, S. G.; Bentzon, M. W.; Houba, V.; Krag, P.

1970-01-01

240

Serum-Sialyltransferase activity in cancer patients  

Microsoft Academic Search

Summary Serum-sialyltransferase activity was measured in serum samples of 116 patients with malignant tumors of various origins and different clinical stages using asialo-fetuin as the acceptor and cytidine-5'-mono-phospho[14C]sialic acid as the donor. Only patients with metastatic tumors had significantly elevated serum-sialyltransferase levels. Increased enzyme activity was also associated with rheumatoid arthritis and with acute hepatitis, whereas no significant alteration of

P.-G. Berge; A. Wilhelm; H. Schriewer; G. Wüst

1982-01-01

241

Serum soluble fas levels in ovarian cancer  

Microsoft Academic Search

Objective: To determine the value of serum soluble Fas levels as a prognostic marker for survival of women with ovarian cancer and as a discriminator between benign and malignant adnexal masses.Methods: Serum soluble Fas levels were measured with an enzyme-linked immunosorbent assay in 52 women with ovarian cancer, 30 women with benign ovarian cysts, and 35 healthy women.Results: Median serum

Lukas Hefler; Klaus Mayerhofer; Alessandra Nardi; Alexander Reinthaller; Christian Kainz; Clemens Tempfer

2000-01-01

242

Serum enzymes in heat stroke: prognostic implication  

Microsoft Academic Search

We measured serum creatine kinase (CK), lactate dehy- drogenase (LD), aspartate aminotransferase (AST), and serum alanine aminotransferase (ALT) in 26 heat stroke (HS) victims and 10 control (non-heat-exhausted) sub- jects during annual Hajj in Makkah, Saudi Arabia. On admission to the HS treatment unit, serum CK, AST, ALT, and LD were higher in HS victims than controls (P <0.05), and

Abdulaziz H. Alzeer; Mohsen A. F. El-Hazmi; Arjumand S. Warsy; Ziauddin A. Ansari; Mohammed S. Yrkendi

243

Mycoplasma growth factors in bovine serum fraction.  

PubMed Central

Mycoplasma growth factors in bovine serum fraction were separated by Sephadex G150 column chromatography and density ultracentrifugation. The major growth factor of bovine serum fraction eluted from the Sephadex column in the void volume. Its growth-supporting activity was greatly enhanced by the presence of bovine serum albumin in the mycoplasma culture media. Other investigators had previously identified the major growth factor in serum as an alpha-lipoprotein. Although density ultracentrifugation revealed the presence of traces of a high-density lipoprotein in bovine serum fraction, another, less dense component, isolated by ultracentrifugation (component 3) and containing cholesterol, cholesteryl esters, free fatty acids, triglycerides, and protein, but no lipoprotein, exhibited considerably more growth-supporting activity than did the high-density lipoprotein, thus indicating that at least two mycoplasma species do not require intact serum lipoprotein for growth. Both the high-density lipoprotein and component 3 exhibited maximum activity only in the presence of bovine serum albumin. A chloroform extract containing component 3 lipids combined with bovine serum albumin to form an effective, partially defined, less complex substitute for serum in mycoplasma culture media. Images

Washburn, L R; Hughes, J H; Somerson, N L

1978-01-01

244

Serum triiodothyronine determination in clinical use.  

PubMed Central

Two radioimmunassays for the determination of serum triiodothyronine (T3) were developed. The assay of T3 in unextracted serum had several advantages over the assay on extracted serum and was chosen for the routine determination of T3 in serum from 117 patients requiring assessment of their thyroid status. In 53 subjects considered retrospectively not to have thyroid dysfunction nor to have been on steroid contraceptives or therapy, the pooled mean serum T3 concentration was 1-92 (actual range 0-88-2-62) nmol/l. A significant inverse relationship was observed between the serum T3 level and the age of the subject. Serum total T3 levels discriminate clearly between hypo-,eu- and hyperthyroid patients and provide a rather more sensitive index of hyperthyroid function than total serum T4. In the face of normal serum T4 the T3 level was depressed in five patients with marked hypoproteinaemia and elevated in two patients taking heroin.

Stafford, J E; Lees, S; Watson, D

1976-01-01

245

Serum Dihydrolipoamide Dehydrogenase Is a Labile Enzyme.  

PubMed

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

2013-03-01

246

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

2009-04-24

247

Polychlorinated biphenyl serum concentrations, lifestyle and time-to-pregnancy  

PubMed Central

BACKGROUND Consumption of fish contaminated with polychlorinated biphenyls (PCBs) and prenatal PCB serum concentrations have been associated with a longer time-to-pregnancy (TTP). However, the relationship between preconception serum PCBs concentrations and TTP has not been previously studied. METHODS Eighty-three women (contributing 442 menstrual cycles) planning pregnancies completed daily diaries regarding menstruation, intercourse, home pregnancy test results, and reported use of alcohol and cigarettes. TTP denoted the number of observed menstrual cycles required for pregnancy. Preconception blood specimens underwent toxicologic analysis for 76 PCB congeners via gas chromatography with electron capture; serum lipids were quantified with enzymatic methods. A priori, PCB congeners were summed into a total and three groupings—estrogenic, anti-estrogenic and other—and entered into discrete analogs of Cox models with time-varying covariates to estimate fecundability odds ratios (FOR) and corresponding 95% confidence intervals (CIs). RESULTS Estrogenic and anti-estrogenic PCB concentrations (ng/g serum) conferred reduced FORs in fully adjusted models (0.32; 95% CI 0.03, 3.90 and 0.01: 95% CI < 0.00, 1.99, respectively). Reduced FORs (0.96) were observed for alcohol consumption standardized to a 28-day menstrual cycle in the same adjusted model (FOR = 0.96; 95% CI 0.93, 1.00). CONCLUSIONS These data suggest that environmental exposures including those amenable to change, such as alcohol consumption, may impact female fecundity. The findings are sensitive to model specification and PCB groupings, underscoring the need to further assess the impact of chemical mixtures on sensitive reproductive outcomes, such as TTP, especially in the context of lifestyle factors which are amenable to change, thereby improving reproductive health.

Buck Louis, G.M.; Dmochowski, J.; Lynch, C.; Kostyniak, P.; McGuinness, B.M.; Vena, J.E.

2009-01-01

248

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

249

Serum deprivation-induced HepG2 cell death is potentiated by CYP2E1  

Microsoft Academic Search

Induction of oxidative stress plays a key role in serum deprivation-induced apoptosis. CYP2E1 plays an important role in toxicity of many chemicals and ethanol and produces oxidant stress. We investigated whether CYP2E1 expression can sensitize HepG2 cells to toxicity as a consequence of serum deprivation. The models used were HepG2 E47 cells that express human CYP2E1, and C34 HepG2 cells

Jian Zhuge; Arthur I. Cederbaum

2006-01-01

250

Development of serum-free media for the growth of human gastrointestinal adenocarcinoma xenografts as primary tissue cultures  

Microsoft Academic Search

Summary The growth-promoting effect of several hormones and growth factors on eight human colon tumor cell lines (SW 48, SW 403, SW 480, SW 620, SW 948, HT29, LS174T and Caco-2) was studied using seven different chemically defined serum-free media [GF3: Chee's essential medium plus insulin, transferrin and selenium; GF3F: GF3 plus fetuin; GF4: GF3 plus linoleic acid\\/ bovine-serum albumin

Karimullah A. Zirvi

1991-01-01

251

Raman Spectroscopy of Serum for Cancer Detection.  

National Technical Information Service (NTIS)

Laser induced auto- fluorescence and Raman spectra of serum from cancerous and normal people are measured and analyzed. Three Raman peaks were consistently observed from normal blood serum emission using 488.0nm and 514.5nm excitation of an Ar-ion laser w...

X. Li H. Jin

2001-01-01

252

Serum Corticosteroid Binding Following Thermal Injury (36257).  

National Technical Information Service (NTIS)

An adsorption technique has been adapted to measure both the total corticosteroid-binding capacity (CBC) and corticosteroid-binding globulin (CBG) capacity of rat serum following thermal injury. A maximum increase in the rat serum CBC was seen 4 days foll...

G. H. Mudge

1971-01-01

253

Serum Cholesterol Binding Reserve in Uremia.  

National Technical Information Service (NTIS)

Serum lipid abnormalities were evaluated in 53 patients (40 men and 23 women) undergoing maintenance hemodialysis and 22 non-uremic patients (14 men and 8 women) with the nephrotic syndrome. Serum levels of cholesterol, triglycerides and high-density-lipo...

G. O. Perez S. L. Hsia

1978-01-01

254

Serum prolidase activity in psoriasis patients.  

PubMed

This study aimed to evaluate serum prolidase activity and the effects of gender, body mass index (BMI), disease severity and duration, and therapy type on prolidase activity in patients with psoriatic as well as the relationship between serum NO· and prolidase levels in these patients. The study included 29 clinically documented plaque patients with psoriasis and 24 healthy volunteers. Data such as age, sex, BMI, duration and severity of disease, and type of therapy were assessed. NO· levels were determined by the Griess reaction. Serum prolidase assay is based on a colorimetric determination of proline by Chinard's reagent. We did not determine any difference in serum NO· levels of psoriatic patients when compared to controls. Serum prolidase levels in psoriasis patients were significantly higher than those in controls. There was no significant difference in prolidase activity between male and female. No statistically significant correlations were found between serum prolidase levels and BMI, PASI and disease duration. When compared between topical treatment group and systemic treatment group, there was no significant difference in serum prolidase activity. In conclusion, patients with psoriasis exhibit higher serum prolidase activity independent of gender, BMI, disease severity or duration, type of treatments or NO· level. However, further studies are needed to verify these findings as well as altered collagen synthesis in patients with psoriasis. PMID:23553128

Guven, Berrak; Can, Murat; Genc, Mehmet; Koca, Rafet

2013-04-04

255

Estimation of serum L. casei activity  

Microsoft Academic Search

Measurement of the serum Lactobacillus casei (`folic-acid') activity is widely used as an index of folic-acid deficiency. Present methods of assay result in recovery of about half the active material in normal serum. A modified method of assay is described which gives higher L. casei values and a clearer distinction between the sera of normal subjects and of patients with

I. Chanarin; Valerie Berry

1964-01-01

256

Serum Protein Profile Alterations in Hemodialysis Patients  

SciTech Connect

Background: Serum protein profiling patterns can reflect the pathological state of a patient and therefore may be useful for clinical diagnostics. Here, we present results from a pilot study of proteomic expression patterns in hemodialysis patients designed to evaluate the range of serum proteomic alterations in this population. Methods: Surface-Enhanced Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (SELDI-TOFMS) was used to analyze serum obtained from patients on periodic hemodialysis treatment and healthy controls. Serum samples from patients and controls were first fractionated into six eluants on a strong anion exchange column, followed by application to four array chemistries representing cation exchange, anion exchange, metal affinity and hydrophobic surfaces. A total of 144 SELDI-TOF-MS spectra were obtained from each serum sample. Results: The overall profiles of the patient and control samples were consistent and reproducible. However, 30 well-defined protein differences were observed; 15 proteins were elevated and 15 were decreased in patients compared to controls. Serum from one patient exhibited novel protein peaks suggesting possible additional changes due to a secondary disease process. Conclusion: SELDI-TOF-MS demonstrated dramatic serum protein profile differences between patients and controls. Similarity in protein profiles among dialysis patients suggests that patient physiological responses to end-stage renal disease and/or dialysis therapy have a major effect on serum protein profiles.

Murphy, G A; Davies, R W; Choi, M W; Perkins, J; Turteltaub, K W; McCutchen-Maloney, S L; Langlois, R G; Curzi, M P; Trebes, J E; Fitch, J P; Dalmasso, E A; Colston, B W; Ying, Y; Chromy, B A

2003-11-18

257

Dietary restriction on serum thyroid hormone levels.  

PubMed

To determine the long term effects of a protein sparing fast on serum thyroid hormone levels, the authors studied 38 obese patients ingesting a diet of 320 kcal for up to 13 weeks. The high baseline serum triiodothyronine (T3) levels decreased significantly by the first week, further decreased by the third week, and this lower level persisted for the duration of the fast until realimentation. Serum free T3 index followed the same general pattern as did serum T3 levels. Serum reverse T3 increased significantly by the first week, but by week three, the reverse T3 level had begun to fall, although still significantly increased above baseline. By week seven, reverse T3 had decreased to almost baseline and remained not significantly changed from the baseline to 13 weeks. Serum thyroxine (T4) increased significantly by the first week in all patients, but by the third week had returned to baseline levels which persisted to 13 weeks. The free T4 index and free T4 concentrations showed the same increment at week one and then returned to baseline levels. There were no significant changes in serum thyroxine-binding globulin (TBG) or thyroid-stimulating hormone (TSH) concentrations. The changes in serum T3 and reverse T3 levels are attributable to alterations in peripheral 5'-monodeiodination of T4 and reverse T3 induced by the protein sparing fast. PMID:2021153

Marine, N; Hershman, J M; Maxwell, M H; Dornfeld, L P; Schroth, P

1991-05-01

258

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

259

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

260

[Fluorescent immunoassay of thyroxine in blood serum].  

PubMed

A method of solid-phase fluoroimmunoassay of thyroxine (T4) on polystyrene 96-microtiter plates using coproporphyrin III-labeled antibodies was developed; 0.02 ml of blood serum without preliminary treatment was required. Thimerosal was added to lessen the T4-binding effect of the serum on the results of T4-binding effect of the serum on the results of the immunoassay. A calibration curve was obtained to determine T4 covering the entire physiological range of concentrations (from 3 to 21 micrograms of thyroxine in 100 ml of the serum). A variation coefficient within this range did not exceed 15%. For 14 unknown blood serum samples of patients the coefficient of correlation with the results obtained using a commercial kit for T4 determination (Abbott, USA) was 0.960. The time of the assay was 2-2.5 h. This method is simple and easy for use on a large scale. PMID:3293030

Papkovski?, D B; Savitski?, A P; Bykhovski?, V Ia

261

Antibacterial properties of serum from the American alligator ( Alligator mississippiensis)  

Microsoft Academic Search

Treatment of alligator (Alligator mississippiensis) and human serum samples with Escherichia coli resulted in a time- and concentration-dependent inhibition of bacterial proliferation. When inoculated with E. coli, alligator serum exhibited 10-fold lower bacterial survival rates after 1 h than human serum. In addition, the antibacterial spectrum of alligator serum was shown to be much broader than that of human serum,

Mark E. Merchant; Cherie Roche; Ruth M. Elsey; Jan Prudhomme

2003-01-01

262

Effects of the polysaccharide from Pholiota nameko on human cytokine network in serum.  

PubMed

Some physico-chemical characterizations of Pholiota nameko polysaccharides (PNPS-1) were studied, including sulfate content, UV/visible and infrared spectra, also the variation of cytokine communication network in serum to clarify the pharmacological effects of PNPS-1 by determination of 39 cytokines in serum of healthy volunteers. The result proved that PNPS-1 possessed significant anti-inflammatory activity. Further, we use Microsoft Visio 2007 software to map out the cell-cell communication network diagram. The analysis to the diagram suggested that PNPS-1 could take effect on the innate and adaptive immunity and hematopoiesis of volunteers. PMID:22044749

Li, Haiping; Liu, Xiaojuan; Li, Yang; Hua, Yanjun; Zhi, Dexian; Pang, Guangchang

2011-10-23

263

[Serum erythropoietin levels in several diseases].  

PubMed

The accurate radioimmunological measurement of serum erythropoietin (EPO) levels has only been possible since the development of highly specific antibodies directed against recombinant human EPO. In the present study, we determined the serum EPO levels in 100 healthy volunteers and in over 300 patients with anemias and hyperglobulinemia of various causes. In the healthy group, the females had levels of 11.3 +/- 3.4 mU/ml, while the males had levels of 8 +/- 3.2 mU/ml. The serum EPO concentrations were inversely related to the degree of anemia in patients with nonrenal anemias, while predialysis patients with renal anemias showed only partially such a tendency. Hemodialysis patients exhibited EPO-levels that were inadequately low relative to the degree of anemia. Patients with hyperglobulinemia had significantly higher serum EPO-levels than healthy individuals and polycythemia vera patients, the latter having particularly low serum EPO levels. Our results show that the determination of serum EPO levels can be of value in the differential diagnosis of hyperglobulinemia. Finally, sequential measurements document fluctuating serum EPO-levels after gastrointestinal hemorrhages and in patients with iron deficiency anemias receiving iron substitution. The probable reason for this phenomenon seems to be the intermittent utilisation of the hormone by EPO-sensitive erythropoietic precursor cells. PMID:2915782

Rhyner, K; Egli, F; Niemöller, M; Wieczorek, A; Greminger, P; Vetter, W

1989-01-01

264

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.

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

2012-01-01

265

Stressful Underwater Demolition Training. Serum Urate and Cholesterol Variability.  

National Technical Information Service (NTIS)

Individuals with ultimately middle to low normal-range levels of serum uric acid and cholesterol demonstrated highly significant rises in these serum fractions during specific stages of a four-month underwater demolition training period. Serum urate conce...

R. H. Rahe R. J. Arthur

1967-01-01

266

Serum collagen markers and heart failure.  

PubMed

Increased myocardial collagen accumulation is present in almost every cardiac disease and plays an important role in the reduced heart function. N-terminal and C-terminal propeptides of collagen type I and III, the two major collagen types in the heart, can be assayed in serum.These propeptides (PINP, PIIINP, PICP, ICTP) reflect collagen synthesis and degradation. The use of these serum collagen biomarkers as prognostic or diagnostic tools is an area of active investigation. In this review article these studies will be discussed as well as the limitations of these serum biomarkers as indicators of cardiac fibrosis. PMID:22524171

Lijnen, P J; Maharani, T; Finahari, N; Prihadi, J S

2012-09-01

267

CHEMICAL PACEMAKERS  

PubMed Central

1. Iron spicules found in the brains of general paretic patients are formed from endogenous brain iron normally present in another form. This supports our earlier view that the µ value of 16,000 obtained in advanced paretics for alpha brain wave frequencies as a measure of cortical respiration comes about from the slowing of an iron catalyzed link in cortical respiration such as would result from the reduction of available cytochrome and its oxidase, thus making this step a chemical pacemaker. 2. To test the basic theory of chemical pacemakers, a study was made of the succinate-fumarate enzyme system containing succino-dehydrogenase and cytochrome-cytochrome oxidase acting sequentially. 3. The µ value for the unpoisoned system is 11,200 ± 200 calories. 4. According to theory, the addition of a critical amount of cyanide known to be a specific poison of the cytochrome-cytochrome oxidase system (and not of the dehydrogenase) should shift the µ cleanly to 16,000 calories, and it does. 5. According to theory, selenite, a specific poison for the dehydrogenase, should stop all respiration without shifting the µ. This also is found to be the case. 6. The theory also predicts that if the µ is shifted from 11,000 ± to 16,000 ± by cyanide, the subsequent addition of a critical amount of selenite should shift the µ back again to 11,000 ± calories, and this is found to occur. 7. It is concluded that approximately 11,000 calories is the energy of activation of the succino-dehydrogenase-catalyzed step and 16,000 calories is that for the cytochrome-cytochrome oxidase-catalyzed step. These two values are encountered more frequently than any others in physiological systems. It is to be recalled that a shift of µ for alpha brain wave frequencies from 11,000 to 16,000 calories occurs in the course of advancing syphilitic brain infection and is accompanied by a change in form of brain iron.

Hadidian, Zareh; Hoagland, Hudson

1939-01-01

268

Serum-sialyltransferase activity in cancer patients.  

PubMed

Serum-sialyltransferase activity was measured in serum samples of 116 patients with malignant tumors of various origins and different clinical stages using asialo-fetuin as the acceptor and cytidine-5'-mono-phospho[14C]sialic acid as the donor. Only patients with metastatic tumors had significantly elevated serum-sialyltransferase levels. Increased enzyme activity was also associated with rheumatoid arthritis and with acute hepatitis, whereas no significant alteration of enzyme activity was observed in cystic fibrosis patients. In a group of tumor patients, various additional tumor markers were determined (carcinoembryonic antigen, alkaline phosphatase: Regan isoenzyme, creatinekinase: BB-isoenzyme, lactatedehydrogenase: isoenzyme 5) and the data compared to the clinical diagnoses. The sensitivity and specificity of serum-sialyltransferase as a tumor marker is assessed. PMID:7045508

Berge, P G; Wilhelm, A; Schriewer, H; Wüst, G

1982-05-01

269

Serum Osmolality in Acutely Injured Patients.  

National Technical Information Service (NTIS)

The study was to determine the etiology and to evaluate the prognostic significance of serum hyperosmolality in acutely injured patients. The case histories of 700 patients admitted to the Maryland Institute for Emergency Medicine were examined, and those...

M. A. Weinstein W. J. Sacco P. J. Nyikos W. Gill H. R. Champion

1974-01-01

270

Effect of cellulose sulphate on serum complement  

PubMed Central

Cellulose sulphate 50-600 ?g/ml reduces complement titres in human serum. This effect is, in contrast to the clot-promoting and plasma kinin forming action of cellulose sulphate, not mediated by clotting factor XII.

Eisen, V.; Loveday, C.

1970-01-01

271

Nonhuman Primate Preclinical Antilymphocyte Serum Testing.  

National Technical Information Service (NTIS)

Despite the clinical use of antilymphocyte serum (ALS) having been established, there exists no reliable in vitro procedure for predicting the immunosuppressive potency of ALS pools prior to clinical use. ALS produced against human lymphoid material has b...

J. J. Smith C. Darrow K. W. Sell G. LaFontaine D. E. Kayhoe

1971-01-01

272

Investigation of Intravenous Serum Immune Globulin.  

National Technical Information Service (NTIS)

Sixty-seven patients have been entered into the protocols. These include 19 patients with primary immunodeficiency, 12 subjects on chronic dialysis and 38 iatrogenically immunodeficient patients with acute infection. The infusion of 150 mg/kilo of serum i...

B. Pirofsky

1975-01-01

273

Suramin Determination by Direct Serum Injection  

Microsoft Academic Search

Suramin is an anti-prostatic tumor drug. Due to its narrow therapeutic range and long half life, frequent monitoring is required to minimize toxicity. We describe here a rapid assay to measure suramin levels in serum. Diluted serum samples are injected directly onto an HPLC cartridge column packed with a wide pore packing material (300A) and eluted with 10 mmol\\/L phosphate

L. L. Garcia; Z. K. Shihabi

1993-01-01

274

Heterologous enzyme immunoassay for serum androstenediol  

Microsoft Academic Search

A heterologous enzyme immunoassay for serum androstenediol (Adiol: 3?, 17?-dihydroxy-androst-5-ene) was established. The combination of anti-Adiol antiserum raised in rabbit against Adiol 7-O-(carboxymethyl)oxime (Adiol 7-CMO) conjugated bovine serum albumin (Adiol 7-CMO-BSA) and Adiol 7-iminomethylcarboxylic acid conjugated alkaline phosphatase was used for the assay. The sensitivity of the heterologous assay system was superior to that of a homologous assay system in

Noriko Tagawa; Junko Tamanaka; Aya Fujinami; Toshiko Kiguchi; Takeaki Naito; Toru Takano; Nobuyuki Amino; Yoshiharu Kobayashi

2000-01-01

275

Changes in Serum Thrombopoietin Levels after Splenectomy  

Microsoft Academic Search

To clarify the role of thrombopoietin (c-Mpl ligand, TPO) in ‘hypersplenic’ thrombocytopenia, we used an enzyme-linked immunosorbent assay to examine changes in serum TPO levels accompanied with splenectomy in 6 patients with liver cirrhosis, 4 patients with gastric cancer, and 2 patients with lymphoid malignancies. We also measured serum levels of other thrombopoietic cytokines such as interleukin-6 (IL-6) and erythropoietin.

Naoaki Ichikawa; Kiyoshi Kitano; Shigetaka Shimodaira; Fumihiro Ishida; Toshiro Ito; Shoji Kajikawa; Tomoyuki Tahara; Takashi Kato; Kendo Kiyosawa

1998-01-01

276

Serum progesterone and estrogens in elephants.  

PubMed

Serum progesterone and estrogens were measured by radioimmunoassay in the serum of immature, mature, and pregnant African and Asian elephants. Progesterone was elevated from 26 to 215 pg/ml in nonpregnant animals and up to 480 pg/ml in late pregnancy animals. No relationship to reproductive state was evident for the low levels of estrogens which ranged from 9 to 37 pg/ml. PMID:1157766

Plotka, E D; Seal, U S; Schobert, E E; Schmoller, G C

1975-08-01

277

Serum ferritin in juvenile chronic polyarthritis.  

PubMed Central

Six children with juvenile chronic polyarthritis were studied and their disease activity correlated with haematological values including serum ferritin. The latter is often raised above reference values, but even when within them appears to fluctuate significantly and correlates more closely with disease activity than any of the other parameters measured. We conclude that the serial measurement of serum ferritin may be a useful guide to the management of such children.

Craft, A W; Eastham, E J; Bell, J I; Brigham, K

1977-01-01

278

Serum erythropoietin level in anemic cancer patients  

Microsoft Academic Search

Anemia is a frequent complication of cancer and its treatment. A defect in erythropoietin production has been advocated as\\u000a being the main cause of anemia in cancer patients. We studied serum erythropoietin levels in 74 patients with solid tumors\\u000a and in a control group consisting of 20 otherwise healthy individuals without any malignancy, who have only iron deficiency\\u000a anemia. Serum

M Ozguroglu; B Arun; G Demir; F Demirelli; NM Mandel; E Buyukunal; S Serdengecti; B Berkarda

2000-01-01

279

Serum-reduced and serum-free media for differentiation of Caco-2 cells.  

PubMed

Human intestinal Caco-2 cells were differentiated using serum-reduced medium with fetal bovine serum (FBS) added only to the basolateral (BL) medium, and four serum-free media, containing insulin, transferrin, selenium (ITS), or MITO+™ serum extender (ITS plus growth factors), with or without addition of a lipid mixture, respectively. Differentiation was assessed by monitoring monolayer permeability, alkaline phosphatase and sucrase activities, and the transport of digoxin and cephalexin. Notably, the serum-reduced protocol produced results that were comparable to cells differentiated in the control medium and should be recommended as an alternative to the use of 10% FBS in both apical (AP) and BL media. ITS serum-free medium elicited permeability values and cephalexin transport similar to control cells. MITO+™ medium was the most efficient in promoting the two transport activities investigated, and it should be further evaluated with a larger set of substances, although its undisclosed composition represents a limit that may override these advantages. PMID:23665805

Ferruzza, Simonetta; Rossi, Carlotta; Sambuy, Yula; Scarino, Maria Laura

2013-01-01

280

Serum crosslaps in comparison to serum osteocalcin and urinary bone resorption markers  

Microsoft Academic Search

In this study we evaluated the routine practice and clinical application of serum crosslaps to urinary-crosslaps, -N-telopeptide-related fraction of type 1 collagen, -deoxpyridinoline, -totalpyridinoline and serum osteocalcin. The utility of both the serum and urine immunoassays for bone formation and resorption marker were tested in a cohort of 593 female and male patients from our outpatient clinic for osteology and

P Peichl; A Griesmacherb; R Marteau; S Hejc; W Kumpan; M. M Müller; H Bröll

2001-01-01

281

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.

2012-01-01

282

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

283

Serum vascular adhesion protein-1 level is higher in smokers than non-smokers.  

PubMed

Abstract Background: Semicarbazide-sensitive amine oxidase (SSAO)/vascular adhesion protein-1 (VAP-1) is involved in the pathogenesis of both atherosclerosis and cancer. Because chemical components and metabolites of cigarettes are deaminated by SSAO, the relationship between smoking and serum SSAO/VAP-1 was studied in humans. Methods: A total of 451 non-diabetic and normoalbuminuric Han Chinese subjects were recruited to participate in this study. Smoking history was obtained by using a questionnaire and those who smoked more than 100 cigarettes during a 6-month period were considered smokers. Serum VAP-1 concentration was measured by time-resolved immunofluorometric assay. Age, gender, waist circumference and estimated glomerular filtration rate (GFR) were adjusted in different statistical models. Results: Smokers were mainly male (85.7% versus 26.3%) and were more obese than non-smokers (p?serum VAP-1 concentrations were older (p?Serum VAP-1 concentration was higher in smokers than in non-smokers (p?serum VAP-1 concentration. Whether VAP-1 and its SSAO activity link the relationship between cigarette smoking, atherosclerosis and cancer requires further investigation. PMID:23802578

Wang, Yi-Chia; Li, Hung-Yuan; Wei, Jung-Nan; Lin, Mao-Shin; Shih, Shyang-Rong; Hua, Cyue-Huei; Smith, David J; Vanio, Jani; Chuang, Lee-Ming

2013-06-27

284

Transient increase of serum Clara cell protein (CC16) after exposure to smoke.  

PubMed Central

OBJECTIVES: Smoke inhalation is a well known cause of airways injury in firefighting personnel. The aim of this study was to evaluate whether toxic effects of smoke on the respiratory tract can be detected by measuring Clara cell protein (CC16), a recently described serum marker of lung function. METHODS: CC16 was measured by a sensitive latex immunoassay in the serum of six voluntary firefighters from a chemical plant who had inhaled smoke from the combustion of polypropylene for about 20 minutes. The protein was measured immediately after the fire and 10 days later. The values were compared with those of six control workers examined simultaneously. RESULTS: The mean (SD) concentration of CC16 in the serum of firefighters after the fire (54.4 (34.9) micrograms/l) was significantly higher than that of controls (19.5 (11.7), P = 0.04). 10 days later, serum CC16 from firefighters had returned to the concentrations found in controls (15.9 (2.76) v 17.7 (12.5)). With the values at day 10 as a baseline, the rise of serum CC16 was estimated at 328% on average (range 100%-564%). These changes were found in the absence of any functional sign of lung impairment. CONCLUSION: Acute exposure to smoke results in a transient increase of CC16 in serum due most likely to an increased permeability of the bronchoalveolar/blood barrier. Serum CC16 seems potentially to be a new biomarker for the early detection of acute airways injury caused by smoke.

Bernard, A; Hermans, C; Van Houte, G

1997-01-01

285

An evaluation of metal bioaccessibility in estuarine sediments using the commercially available protein, bovine serum albumin  

Microsoft Academic Search

The bioaccessibility of metals (Al, Ca, Fe, Mn, Ag, Cd, Co, Cu, Ni, Pb, Sn, Zn) in oxic estuarine sediments has been evaluated using solutions of a commercially available protein (bovine serum albumin; BSA) that mimic the chemical conditions encountered in the gut environment of many deposit-feeding organisms. Over a 20 h incubation period with 5 g L?1 BSA, metal mobilisation was

Judit Kalman; Andrew Turner

2007-01-01

286

Serum Alters the Uptake and Relative Potencies of Halogenated Aromatic Hydrocarbons in Cell Culture Bioassays  

Microsoft Academic Search

1 The effects of many chemicals on cellular processes are gov- erned by their ability to enter the cell, which is in turn a function of the composition of the cell's external environment. To examine this relationship, the effect of serum in cell culture medium on the bioavailability of cytochrome P450 1A (CYP1A)-inducing com- pounds was determined in PLHC-1 (Poeciliopsis

Eli V. Hestermann; John J. Stegeman; Mark E. Hahn

2000-01-01

287

Adsorption of human serum albumin on to synthesized dye-like polystyrene gel beads  

Microsoft Academic Search

In bioseparation, adsorption of proteins on to various polymer surfaces plays an important role in different fields, particularly in pseudo-affinity chromatography techniques. In this context, this study aims to synthesize cross-linking polystyrene gel beads as packing material in column chromatography for albumin purification. Suitable chemical groups, such as sulfonate and l-cysteine with high affinity towards human serum albumin were introduced

N Belattar; T Mekhalif

2004-01-01

288

Complexation of fluoroquinolone antibiotics with human serum albumin: A fluorescence quenching study  

Microsoft Academic Search

Mechanism of interaction and detailed physico-chemical characterization of the binding of four fluoroquinolones: levofloxacin, sparfloxacin, ciprofloxacin HCl and enrofloxacin with human serum albumin has been studied at physiological pH (7.4) using fluorescence spectroscopic technique. The stoichiometry of interaction was found to be 1:1 for all the drugs used. The association constants for the interaction were of the order of 104

Neelam Seedher; Pooja Agarwal

2010-01-01

289

Intake, serum concentrations, and urinary excretion of manganese by adult males'3  

Microsoft Academic Search

ABSTRACI' Nutritional status of manganese in 10 adult males was monitored through a 47-d period by measuring manganese in serum and urine and by chemically analyzing duplicate portions ofall foods and beverages consumed on 3 d, with computer analysis of dietary records for 10 additional days. Subjects consumed 0.52-5.33 mg Mn\\/d; 50% ofthe time they consumed less than the 1980

JL Greger; Cindy D Davis; BJ Lyle

290

Chemical Ecology: Chemical Communication in Nature.  

ERIC Educational Resources Information Center

|Substances that deliver chemical messages between same/different species are called semiochemicals. Surveyed are three types of semiochemicals (pheromones, allomones, and kairomones), types of organisms involved, and specific chemicals used to carry the various kinds of messages. (JN)|

Wood, William F.

1983-01-01

291

Applicability of direct total reflection X-ray fluorescence analysis in the case of human blood serum samples  

Microsoft Academic Search

Total Reflection X-Ray Fluorescence (TXRF) is a well-established method, mainly applied in the analysis of liquid samples, offering very low detection limits in most of the cases. Direct application of the TXRF method is not so efficient in blood serum analysis, since the high content of the organic matrix increases significantly the background due to Compton scattering. Chemical treatment of

Ch. Zarkadas; A. G. Karydas; T. Paradellis

2001-01-01

292

Mechanical and Biochemical Characterization of Cartilage Explants in Serum-Free Culture  

PubMed Central

Allografts of articular cartilage are both used clinically for tissue-transplantation procedures and experimentally as model systems to study the physiological behavior of chondrocytes in their native extracellular matrix. Long-term maintenance of allograft tissue is challenging. Chemical mediators in poorly defined culture media can stimulate cells to quickly degrade their surrounding extracellular matrix. This is particularly true of juvenile cartilage which is generally more responsive to chemical stimuli than mature tissue. By carefully modulating the culture media however it may be possible to preserve allograft tissue over the long-term while maintaining its original mechanical and biochemical properties. In this study juvenile bovine cartilage explants (both chondral and osteochondral) were cultured in both chemically defined medium and serum-supplemented medium for up to 6 weeks. The mechanical properties and biochemical content of explants cultured in chemically-defined medium were enhanced after 2 weeks in culture and thereafter remained stable with no loss of cell viability. In contrast, the mechanical properties of explants in serum-supplemented medium were degraded by (~70%) along with a concurrent loss of biochemical content (30~40% GAG). These results suggest that long-term maintenance of allografts can be extended significantly by the use of a chemically-defined medium.

Bian, L.; Lima, E.G.; Angione, S.L..; Ng, K.W.; Williams, D.Y.; Xu, D.; Stoker, A.M.; Cook, J.L.; Ateshian, G.A.; Hung, C.T.

2012-01-01

293

Serum concentration of visfatin in obese women.  

PubMed

The aim of the present study was to determine serum concentrations of visfatin in obese women in comparison to normal-weight controls. Study subjects were 21 obese women without additional disease (age, 29.0+/-4.9 years; body mass index, 37.1+/-6.1 kg/m2) and 16 healthy, normal-weight women (age, 29.9+/-5.4 years; body mass index, 22.5+/-1.7 kg/m2). Body composition was measured by bioimpedance. Serum concentrations of visfatin were assayed with an enzyme-linked immunosorbent assay kit (Phoenix Pharmaceuticals, Burlingame, CA). Insulin was determined by radioimmunoassay and glucose by colorimetric method. Serum concentration of visfatin was significantly higher in obese women when compared to controls. Positive correlations between serum concentrations of visfatin and insulin in the obese group were found. In the control group, we observed positive correlations between serum concentrations of visfatin and glucose. In conclusion, the observed increase of visfatin in obesity may be a counterregulation preventing further glucose increase. PMID:17618961

Zahorska-Markiewicz, Barbara; Olszanecka-Glinianowicz, Magdalena; Janowska, Joanna; Koce?ak, Piotr; Semik-Grabarczyk, Elzbieta; Holecki, Micha?; Dabrowski, Piotr; Skorupa, Anna

2007-08-01

294

Peptidomic Identification of Serum Peptides Diagnosing Preeclampsia  

PubMed Central

We sought to identify serological markers capable of diagnosing preeclampsia (PE). We performed serum peptide analysis (liquid chromatography mass spectrometry) of 62 unique samples from 31 PE patients and 31 healthy pregnant controls, with two-thirds used as a training set and the other third as a testing set. Differential serum peptide profiling identified 52 significant serum peptides, and a 19-peptide panel collectively discriminating PE in training sets (n?=?21 PE, n?=?21 control; specificity?=?85.7% and sensitivity?=?100%) and testing sets (n?=?10 PE, n?=?10 control; specificity?=?80% and sensitivity?=?100%). The panel peptides were derived from 6 different protein precursors: 13 from fibrinogen alpha (FGA), 1 from alpha-1-antitrypsin (A1AT), 1 from apolipoprotein L1 (APO-L1), 1 from inter-alpha-trypsin inhibitor heavy chain H4 (ITIH4), 2 from kininogen-1 (KNG1), and 1 from thymosin beta-4 (TMSB4). We concluded that serum peptides can accurately discriminate active PE. Measurement of a 19-peptide panel could be performed quickly and in a quantitative mass spectrometric platform available in clinical laboratories. This serum peptide panel quantification could provide clinical utility in predicting PE or differential diagnosis of PE from confounding chronic hypertension.

Wu, Shuaibin; Stevenson, David K.; Sheng, Guojun; Butte, Atul J.; Ling, Xuefeng B.

2013-01-01

295

Modern Chemical Technology, Guidebook for Chemical Technicians.  

ERIC Educational Resources Information Center

|This volume is a part of the ACS "Modern Chemical Technology" (ChemTeC) curriculum that is developed for chemical technicians. It is intended as a handbook that will be used throughout the instruction. Safety is stressed in eight of the ten chapters under the headings: safety in the chemical laboratory, personal protective equipment, fire safety…

Pecsok, Robert L.; Chapman, Kenneth

296

Microfluidic chemical reaction circuits  

DOEpatents

New microfluidic devices, useful for carrying out chemical reactions, are provided. The devices are adapted for on-chip solvent exchange, chemical processes requiring multiple chemical reactions, and rapid concentration of reagents.

Lee, Chung-cheng (Irvine, CA); Sui, Guodong (Los Angeles, CA); Elizarov, Arkadij (Valley Village, CA); Kolb, Hartmuth C. (Playa del Rey, CA); Huang, Jiang (San Jose, CA); Heath, James R. (South Pasadena, CA); Phelps, Michael E. (Los Angeles, CA); Quake, Stephen R. (Stanford, CA); Tseng, Hsian-rong (Los Angeles, CA); Wyatt, Paul (Tipperary, IE); Daridon, Antoine (Mont-Sur-Rolle, CH)

2012-06-26

297

Lipophilic chemical exposure as a cause of cardiovascular disease  

PubMed Central

Environmental chemical exposure has been linked to numerous diseases in humans. These diseases include cancers; neurological and neurodegenerative diseases; metabolic disorders including type 2 diabetes, metabolic syndrome and obesity; reproductive and developmental disorders; and endocrine disorders. Many studies have associated the link between exposures to environmental chemicals and cardiovascular disease (CVD). These chemicals include persistent organic pollutants (POPs); the plastic exudates bisphenol A and phthalates; low molecular weight hydrocarbons (LMWHCs); and poly nuclear aromatic hydrocarbons (PAHs). Here it is reported that though the chemicals reported on differ widely in chemical properties and known points of attack in humans, a common link exists between them. All are lipophilic species that are found in serum. Environmentally induced CVD is related to total lipophilic chemical load in the blood. Lipophiles serve to promote the absorption of otherwise not absorbed toxic hydrophilic species that promote CVD.

2013-01-01

298

Serum cholesterol in healthy postmenopausal women.  

PubMed

Hypercholes erolaemia is a modifiable risk factor in atherosclerosis. Women lose their relative protection against coronory heart disease at menopause because of changed lipid profile due to oestrogen deficiency. Total serum cholesterol was estimated in 82 healthy postmenopausal women in the age group of 46-72 years (51.5 +/- 7.39). Thirty five healthy pre-menopausal women in the age group of 18-38 years (29.5 +/- 6.4) served as controls. The mean serum cholesterol concentration was significantly higher in the postmenopausal group compared to control group (178.5 +/- 39.8 Vs 155.4 +/- 24 mg/dl; P < 0.01). Serum cholesterol concentration in the study group was not related to social class, dietary habit and obesity. PMID:9808910

Samanta, B B

1998-05-01

299

Serum and CSF immunological findings in ALS.  

PubMed

Serum and CSF immunological findings were analysed in 37 patients with amyotrophic lateral sclerosis (ALS). ALS patients had significantly higher mean values of serum IgG and complement component C4 and significantly lower mean value of total haemolytic titre of complement (THC) compared with normal controls. Incidence of immune complexes (ICs) was significantly higher in sera of ALS patients than in normal controls. There was no significant difference regarding mean serum levels of IgM, IgA, and complement components C3 and Factor B between patients and controls. The blood-brain barrier (BBB) damage was found in 46% of patients. Intrathecal IgG synthesis was detected in six patients (16%). These results support the hypothesis of immune system involvement in ALS. PMID:2017904

Apostolski, S; Nikoli?, J; Bugarski-Prokopljevi?, C; Mileti?, V; Pavlovi?, S; Filipovi?, S

1991-02-01

300

Algal Sensory Chemical Ecology  

Microsoft Academic Search

Sensory chemical ecology is the branch of chemical ecology that focuses on chemical communications between organisms and chemical\\u000a sensing of the environment by organisms. Algae are well known to have numerous physiological responses to variations in their\\u000a chemical environment, particularly with respect to nutrients (Lobban and Harrison 1994). However, with respect to environmental\\u000a sensing it is typical for “chemical ecology”

Charles D. Amsler

301

Nature's chemicals and synthetic chemicals: Comparative toxicology  

SciTech Connect

The toxicology of synthetic chemicals is compared to that of natural chemicals, which represent the vast bulk of the chemicals to which humans are exposed. It is argued that animals have a broad array of inducible general defenses to combat the changing array of toxic chemicals in plant food (nature's pesticides) and that these defenses are effective against both natural and synthetic toxins. Synthetic toxins such as dioxin are compared to natural chemicals, such as indole carbinol (in broccoli) and ethanol. Trade-offs between synthetic and natural pesticides are discussed. The finding that in high-dose tests, a high proportion of both natural and synthetic chemicals are carcinogens, mutagens, teratogens, and clastogens (30-50{percent} for each group) undermines current regulatory efforts to protect public health from synthetic chemicals based on these tests.

Ames, B.N.; Profet, M.; Gold, L.S. (Univ. of California, Berkeley (USA))

1990-10-01

302

Depletion of TGF-? from fetal bovine serum.  

PubMed

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 cross-react with bovine LAP, and developed a protocol to deplete TGF-? from FBS. This provides the ability to reliably quantify TGF-? in vitro without relying on serum-free media which do not support growth of murine T cells. PMID:20837018

Oida, Takatoku; Weiner, Howard L

2010-09-15

303

Relationship of Serum HER2\\/neu and Serum CA 15-3 in Patients with Metastatic Breast Cancer  

Microsoft Academic Search

Background: Serum HER-2\\/neu antigen concentrations have been reported to correlate with increased tumor volume in patients with breast cancer. We measured serum CA 15-3, a surrogate marker of disease burden, and correlated serum CA 15-3 with serum HER-2\\/neu and analyzed the association of both markers with clinical outcomes. Methods: Pretreatment serum samples from 566 patients were retrospectively analyzed from 2

Suhail M. Ali; Kim Leitzel; Vernon M. Chinchilli; Linda Engle; Laurence Demers; Harold A. Harvey; Walter Carney; Jeffrey W. Allard; Allan Lipton

304

Investigation of the health status of Michigan chemical corporation employees.  

PubMed Central

Clinical findings are reported for a group of 55 employees of the Michigan Chemical Corporation which manufactured FireMaster BP-6 from 1970 to 1974, in addition to a variety of other halogenated fire retardant chemicals. The results are compared with those from a group of male farm residents and consumers from Michigan examined at the same time. An increased prevalence of chest and skin symptoms was observed, compared with farmers. Skin symptoms were more prevalent among former PBB production personnel. Musculosketal symptoms were less prevalent among these workers than among farmers. Serum PBB concentrations are signicantly higher than among farmers. Blood chemistry results were similar for workers and farmers. However, both groups exhibited a significantly higher prevalence of elevated liver function tests (SGOT, SPGT) than a control population of nonexposed farmers. Both farmers and chemical workers showed an association of elevated CEA with serum PBB greater than 10 ppb.

Anderson, H A; Wolff, M S; Fischbein, A; Selikoff, I J

1978-01-01

305

Cell cycle synchronization of porcine fetal fibroblasts: effects of serum deprivation and reversible cell cycle inhibitors.  

PubMed

The success of somatic nuclear transfer critically depends on the cell cycle stage of the donor nucleus and the recipient cytoplast. In this study we tested serum deprivation as well as two reversible cell cycle inhibitors, aphidicolin and butyrolactone I, for their ability to synchronize porcine fetal fibroblasts at either G0 stage or G1/S or G2/M transition. The synchronization efficiency of the various protocols was determined by fluorescence-activated cell sorting (FACS), cell proliferation assays, and semiquantitative multiplex reverse transcription-polymerase chain reaction detection of the cell cycle-regulated porcine Polo-like kinase mRNA (Plk-p). FACS measurements revealed that 66.6-73.3% of the porcine fetal fibroblasts were in G0/G1 stage (2C DNA content) in serum-supplemented medium. Short periods of 24-72 h of serum deprivation significantly increased the proportion of cells at G0/G1 phase to 77.9-80.2%, and mitotic activity had already terminated after 48 h. Prolonged culture in serum-deprived medium induced massive DNA fragmentation. Aphidicolin treatment led to an accumulation of 81.9 +/- 4.9% of cells at the G1/S transition. Butyrolactone I arrested 81.0 +/- 5.8% of the cells at the end of G1 stage and 37.0 +/- 6.8% at the G2/M transition. The effects of both chemical inhibitors were fully reversible, and their removal led to a rapid progression in the cell cycle. The measurement of Plk-p expression allowed discrimination between the presumptive G0 phase induced by serum deprivation and the G1/S transition arrest achieved by chemical inhibitors. These data indicate that porcine fetal fibroblasts can be effectively synchronized at various cell cycle stages without compromising their proliferation capacity. PMID:10642581

Kues, W A; Anger, M; Carnwath, J W; Paul, D; Motlik, J; Niemann, H

2000-02-01

306

Hypothalamic digoxin, hemispheric chemical dominance, and spirituality.  

PubMed

The isoprenoid pathway was assessed in atheistic and spiritually inclined individuals. The pathway was also assessed in individuals with differing hemispheric dominance to assess whether hemispheric dominance has a correlation with spiritual and atheistic tendency. HMG CoA reductase activity, serum digoxin, RBC membrane Na(+)-K+ ATPase activity, serum magnesium, and tyrosine/tryptophan catabolic patterns were assessed in spiritual/atheistic individuals and in those differing hemispheric dominance. In spiritually-inclined individuals, there was increased digoxin synthesis, decreased membrane Na(+)-K+ ATPase activity, increased tryptophan catabolites (serotonin, quinolinic acid, and nicotine), and decreased tyrosine catabolites (dopamine, noradrenaline, and morphine). The pattern in spiritually-inclined individuals correlated with right hemispheric chemical dominance. In atheistic individuals there was decreased digoxin synthesis, increased membrane Na(+)-K+ ATPase activity, decreased tryptophan catabolities (serotonin, quinolinic acid, and nicotine), and increased tyrosine catabolites (dopamine, noradrenaline, and morphine). This pattern in atheistic individuals correlated with that obtained in left hemispheric chemical dominance. Hemispheric chemical dominance and hypothalamic digoxin could regulate the predisposition to spirituality or atheism. PMID:12803140

Kurup, Ravi Kumar; Kurup, Parameswara Achutha

2003-03-01

307

[Diagnostic value of serum erythropoietin levels].  

PubMed

Erythropoietin (Epo) is a hormone-like glycoprotein regulating erythropoiesis. Under normal conditions Epo stimulates mitoses of the erythroid progenitors and precursors, decreases apoptosis, decreases "ineffective erythropoiesis" and stimulates the synthesis of the specific protein, haemoglobin. Epo producing cells in the kidney sense the O2 tension of kidney tissue and react to hypoxia with increased Epo production and to O2 saturation (polycythaemia) with decreased or completely abolished Epo production. Normal level of Epo in the serum is 3-20 mU/ml. If Epo production is functioning normally there exists a strict inverse correlation between serum Epo level and hematocrit: an exponential increase in Epo level can be observed if hematocrit decreases. Any damage in Epo production lead to inadequate production (e.g. renal anaemias). This paper analyses the Epo content of 278 serum samples assayed in the Laboratory of Experimental Bone Marrow Transplantation of the National Institute of Hematology and Immunology between August 1996 and December 1997 for their diagnostic value. Those samples are primarily discussed where Epo assay was meant to decide diagnosis of polycythaemia vera or those where decision of Epo treatment of anaemic patients depended on their serum Epo level. PMID:10083814

Gidáli, J; Fehér, I

1999-02-21

308

Plasmalogen oxidation in human serum lipoproteins  

Microsoft Academic Search

The content of plasmalogens in lipoproteins — very low density lipoprotein (VLDL), low density lipoprotein (LDL) and high density lipoprotein (HDL) — in human serum was determined and compared with that after oxidation of the lipoproteins. Similarly, the content of ?-hydroxyaldehydes produced from plasmalogens via their epoxids during lipidperoxidation (LPO) was studied. Incubation with Fe++\\/ascorbate results in a dramatic decrease

Roswitha Felde; Gerhard Spiteller

1995-01-01

309

Cardiovascular Drugs and Serum Uric Acid  

Microsoft Academic Search

Uric acid (UA) is the final product of purine catabolism in man, and it is excreted mainly by the kidneys when renal function is not impaired. Consequently, serum (S) UA increases as a function of purine intake, and it varies inversely to uricosuria. The latter variable diminishes in response to low-sodium intakes and vice versa. Insofar as the diet is

Ariel J. Reyes

2003-01-01

310

Urban pollution and nickel concentration in serum  

Microsoft Academic Search

The study's objective has been to evaluate whether urban pollution, here nickel compounds and metallic nickel (Ni) are present, could determine serum concentrations of the above mentioned metal. Out of a population of 394 Municipal Police employees, subjects with main confounding factors were eliminated. The remaining subjects were made comparable for sex, age, and length of employment. Thus, 160 subjects

Francesco Tomei; Maria Valeria Rosati; Manuela Ciarrocca; Maria Rosaria Marchetti; Tiziana Paola Baccolo; Vincenza Anzelmo; Enrico Tomao

2004-01-01

311

Antimeasles specificity of anticytochrome C serums.  

PubMed

The serums of cytochrome C immunized guinea pigs recognize measles virus hemagglutinin. Antimeasles specificity is confirmed by seroneutralization and immunodiffusion reactions. Cytochrome C preimmunized guinea pigs, when inoculated with measles hemagglutinin, present booster-type increases of the antiviral titres. PMID:2821676

Cernescu, C

312

Molecular Serum Markers of Liver Fibrosis  

PubMed Central

Fibrosis is a hallmark histologic event of chronic liver diseases and is characterized by the excessive accumulation and reorganization of the extracellular matrix (ECM). The gold standard for assessment of fibrosis is liver biopsy. As this procedure has various limitations, including risk of patient injury and sampling error, a non-invasive serum marker for liver fibrosis is desirable. The increasing understanding of the pathogenesis of hepatic fibrosis has suggested several markers which could be useful indicators of hepatic fibrogenesis and fibrosis. These markers include serum markers of liver function, ECM synthesis, fibrolytic processes, ECM degradation and fibrogenesis related cytokines. Recently, neo-epitopes, which are post-translational modifications of proteins, have been successfully used in bone and cartilage diseases which are characterized by extensive ECM remodeling. Increasing numbers of studies are being undertaken to identify neo-epitopes generated during liver fibrosis, and which ultimately might be useful for diagnosing and monitoring fibrogenesis. To date, the metalloproteinases generated fragment of collagen I, III, IV and VI have been proven to be elevated in two rat models of fibrosis. This review summarizes the recent efforts that have been made to identify potentially reliable non-invasive serum markers. We used the recently proposed BIPED (Burden of disease, Investigative, Prognostic, Efficacy and Diagnostic) system to characterize potential serum markers and neo-epitope markers that have been identified to date.

Liu, Tianhui; Wang, Xiaoming; Karsdal, Morten A.; Leeming, Diana J.; Genovese, Federica

2012-01-01

313

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

314

Decreased Serum Leptin in Bulimia Nervosa  

Microsoft Academic Search

The eating disorder bulimia nervosa has been associated with impaired satiety, decreased resting metabolic rate, and abnormal neuroendocrine regulation. Preclinical studies suggest that such al- terations could be associated with impaired leptin function. Thus, the goal of this study was to assess whether leptin function is decreased in bulimia nervosa. Serum leptin levels measured in women with bulimia nervosa (n

DAVID C. JIMERSON; CHRISTOS MANTZOROS; BARBARA E. WOLFE; ERAN D. METZGER

315

Prolonged exercise decreases serum leptin concentrations  

Microsoft Academic Search

Serum leptin and free fatty acid concentrations were determined in two groups of subjects undergoing strenuous exercise: 12 men who fasted overnight and then pedaled a stationary ergometer for 2 hours, and 14 nonfasting ultramarathon runners. Blood samples were collected before exercise, immediately after cessation of exercise, and 6 to 24 hours after the end of the exercise period. Two

Michael Landt; George M. Lawson; Jane M. Helgeson; Victor G. Davila-Roman; Jack H. Ladenson; Allan S. Jaffe; Robert C. Hickner

1997-01-01

316

Serum complement activation in congestive heart failure  

Microsoft Academic Search

Background Although activation of the complement system in myocardial infarction and cardiopulmonary bypass has been shown to contribute to myocardial injury, its role in congestive heart failure (CHF) is unknown. The purpose of this study was to determine the presence of terminal complement activation and its relation to clinical outcomes in patients with CHF. Methods We measured serum levels of

David J. Clark; Michael W. Cleman; Steven E. Pfau; Scott A. Rollins; Tarik M. Ramahi; Craig Mayer; Teresa Caulin-Glaser; Edouard Daher; Mikhail Kosiborod; Leonard Bell; John F. Setaro

2001-01-01

317

Purification and characterization of human serum hyaluronidase.  

PubMed

Hyaluronidase from fresh human serum was purified to apparent homogeneity in a two-step procedure. Potent serum inhibitors of hyaluronidase activity were removed during the course of the purification. Isolation of the enzyme was expedited by the use of a newly devised ELISA-like assay. Enzyme activity was measured by following the rates of hydrolysis of hyaluronan (HA) adsorbed onto microtiter wells. Following enzymatic digestion, the remaining HA was measured using a cartilage-derived biotinylated HA-binding protein and an avidin-peroxidase reaction. Molecular sieve chromatography yielded a doublet of proteins with apparent molecular sizes of 42 and 50 kDa. The molecular size of the major band of protein obtained on sodium dodecyl sulfate-polyacrylamide gel electrophoresis under nonreducing conditions was 59 kDa. Under reducing conditions, however, the size increased to 72 kDa. The pH optimum of the enzyme was 3.7. Sodium chloride concentrations greater than 100 mM were inhibitory. Activity of the serum enzyme was further characterized with a new HA-substrate gel procedure. The serum enzyme activity is different from the liver-derived activity. The tissue source of this circulating enzyme is unknown. PMID:8373180

Afify, A M; Stern, M; Guntenhöner, M; Stern, R

1993-09-01

318

Abnormalities of serum calcium and magnesium  

Technology Transfer Automated Retrieval System (TEKTRAN)

Neonatal hypocalcemia is defined as a total serum calcium concentration of <7 mg/dL or an ionized calcium concentration of <4 mg/dL (1mmol/L). In very low birth weight (VLBW) infants, ionized calcium values of 0.8 to 1 mmol/L are common and not usually associated with clinical symptoms. In larger in...

319

HPTLC determination of diclofenac sodium from serum  

Microsoft Academic Search

Diclofenac sodium is one of the potent Non Steroidal Anti-Inflammatory Drugs (NSAID) used in the treatment of inflammatory conditions. The present work deals with the estimation of diclofenac sodium from serum by a novel High Performance Thin Layer Chromatographic (HPTLC) method developed in our laboratory. Standard diclofenac sodium was spotted on Silica Gel 60 F254 precoated plates, which were developed

L. G Lala; P. M D'Mello; S. R Naik

2002-01-01

320

ELECTRON MICROSCOPY OF SERUM SICKNESS NEPHRITIS  

Microsoft Academic Search

The morphology of antigen-antibody reactions in tissues has been amply documented by studies with the light microscope. At the cytological level, however, the intracellular changes elicited by antigen-antibody union have been poorly defined and vaguely located. As an experimental model to study this problem, serum sickness nephritis was selected first, because there was already a fairly large accumulation of data

JOSEPH D. FELDMAN

321

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

322

Cranial polyneuropathy with elevated serum antiganglioside antibody  

Microsoft Academic Search

We report a 6-year-old girl with cranial polyneuropathy with elevated serum levels of antiganglioside antibodies. She manifested herpetic vesicles around the right upper eyelid and mouth without antecedent infection. She developed facial asymmetry and double vision 5 days after the first apperance of the vesicles. Neurological examination on admission disclosed palsies of the bilateral sixth and twelfth cranial nerves and

Kousaku Matsubara; Hiroyuki Nigami; Hidekazu Harigaya; Kunizou Baba

1997-01-01

323

Serum chemerin levels during normal human pregnancy.  

PubMed

During gestation there are important changes in maternal metabolism and an increase in insulin resistance, coinciding with an increase in adiposity. Chemerin is an adipocytokine which is expressed and secreted in various tissues, including placenta, and may play an important role in metabolic regulation during pregnancy. The aim of this study was to determine serum levels of chemerin during gestation and compare them to other indicators of insulin resistance. A cross-sectional study was carried out analyzing serum chemerin levels of 20 pregnant women during three gestational periods, early, middle, and late (between the 10th and 14th, the 23rd and 26th, and the 34th and 37th week) and 20 non-pregnant women were used as a control group. An analysis of chemerin levels during the menstrual cycle was performed in an eumenorrheic group (n=16) in the early follicular (cycle day 4±1) and the midluteal phase (cycle day 22±1), demonstrating that serum chemerin levels did not fluctuate significantly. Serum levels of chemerin were significantly elevated during late gestation when compared to early (P<0.001) and middle (P=0.001) gestation and a negative correlation between serum chemerin and adiponectin levels (r=-0.1643) became more significant when the non-pregnant group was included in the calculations (r=-0.2471). There was no significant association of triglycerides, total cholesterol, LDL, HDL, insulin, and HOMA levels with chemerin. Although chemerin rose significantly and is negatively associated with adiponectin levels, it is not correlated with other markers of insulin sensitivity, suggesting that more study is needed to determine whether chemerin is useful in predicting insulin resistance during gestation. PMID:23313148

Garces, Maria F; Sanchez, Elizabeth; Ruíz-Parra, Ariel I; Rubio-Romero, Jorge Andrés; Angel-Müller, Edith; Suarez, Miguel A; Bohórquez, Luisa F; Bravo, Susana B; Nogueiras, Rubén; Diéguez, Carlos; Caminos, Jorge E

2013-01-08

324

Exposure to Hexabromocyclododecanes (HBCDs) via Dust Ingestion, but Not Diet, Correlates with Concentrations in Human Serum: Preliminary Results  

PubMed Central

Background Hexabromocyclododecane (HBCD) is a high-production-volume chemical used as flame retardant in polystyrene insulation and textiles. Because it is not chemically bound to the polymer, HBCD can migrate into the environment, contaminating indoor dust and foodstuff. Objectives We examined for the first time the relationship between combined exposure to three HBCD isomers (?HBCDs) via ingestion of food (duplicate diets) and indoor dust and HBCD concentrations in serum for 16 Belgian adults (20–25 years of age). We also determined the chiral signatures of HBCDs to advance understanding of source-to-human enantioselective degradation and/or metabolism. Methods Concentrations and chiral signatures of ?-, ?-, and ?-HBCD in duplicate diets, dust, and serum were measured by liquid chromatography/tandem mass spectrometry. Results Dietary intakes of ?HBCDs were 1.2–20 ng/day (average, 7.2 ng/day), whereas those estimated under average (20 mg dust/day) and high (50 mg dust/day) dust ingestion scenarios were 1.1–15 ng/day (average intake, 3.2 ng/day) and 2.8–38 ng/day (average intake, 8.0 ng/day), respectively. Concentrations of ?HBCDs measured in blood serum were < 0.5 to 11 ng/g lipid weight (lw) (average, 2.9 ng/g lw). ?-HBCD dominated in food, whereas ?-HBCD dominated in dust and was the sole isomer in serum. Although exposure via dust ingestion correlated significantly (p < 0.01) with concentrations in serum, no such correlation was evident with dietary exposure (p > 0.1). Although no enantioselective enrichment was detected in either dust or diet, substantial enrichment of (?)?-HBCD was observed in serum. Conclusions Serum concentrations of HBCDs were correlated with the exposure via dust, but not via dietary ingestion. The enrichment of the (?)?-HBCD enantiomer in humans appears to be due to in vivo enantioselective metabolism/excretion rather than ingestion of dust or diet.

Roosens, Laurence; Abdallah, Mohamed Abou-Elwafa; Harrad, Stuart; Neels, Hugo; Covaci, Adrian

2009-01-01

325

A Simple Serum-free Freezing Medium for Serum-free Cultured Cells  

Microsoft Academic Search

Because the presence of serum in cell culture raises safety problems for the production of biologicals, we have developed a serum-free medium (SFM) for the cryopreservation of animal cells. This medium is based on the SFM MDSS2, to which 10% dimethylsulfoxide (DMSO) and 0·1% methylcellulose or 3% polyvinyl pyrrolidone or no other additive than DMSO were added. Both, Vero and

O.-W. Merten; S. Petres; E. Couvé

1995-01-01

326

Increased serum copper and decreased serum zinc levels in children with iron deficiency anemia  

Microsoft Academic Search

In order to evaluate serum copper and zinc status in children with iron deficiency anemia (IDA), 60 children with IDA aged\\u000a 1–14 yr and 64 healthy children as controls aged 1–14 yr were included the study. Serum copper levels were higher in children\\u000a with IDA (189 ± 49 (?g\\/dL) than those of controls (163 ± 37 ?g\\/dL) (p = 0.001).

Aydin Ece; Bekir Sami Uyamik; Akin I?can; Pelin Ertan; M. Ramazan Yi?itolu

1997-01-01

327

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

328

The serum glucose response to glucagon suppression with somatostatin, insulin or antiglucagon serum in depancreatized rats.  

PubMed

Total immunoreactive glucagon (IRG) and immunoreactive glucagon of A cell origin (IRGa) were measured in the serum of normal, sham-operated and depancreatized rats, after the administration of three glucagon antagonists: insulin (5--200 mU/rat/h), somatostatin (SRIF; 100 microgram/kg/h) and antiglucagon serum (AGS, enough to bind three times the calculated total amount of circulating IRG). Since no differences were noted between the responses of normal and sham-operated animals, the values were pooled and used as controls. Pancreatectomy caused a significant increase in serum glucose, IRGa and total IRG and a significant decrease in serum insulin. AGS and SRIF significantly decreased serum glucose in control, but not in depancreatized rats, even though SRIF caused a significant decrease of IRGa in all animals. SRIF significantly decreased plasma insulin in control rats, but did not modify total IRG secretion in either groups. In control rats the minimum effective hypoglycaemic dose of insulin (5 mU/rat/h) may have decreased serum IRGa, but not total IRG. At higher doses (20 mU/rat/h) insulin stimulated glucagon secretion. In depancreatized animals, higher doses of insulin (200 mU/rat/h) were needed to lower serum glucose. On the other hand, a dose of 100 muU/rat/h was sufficient to lower the serum IRG. We conclude that although hyperglucagonaemia may contribute to the hyperglycaemia of the untreated depancreatized rats, the excessive secretion of glucagon is secondary to insulin insufficiency and that, at least in this animal model, the hypoglycaemic action of insulin is only minimally dependent upon its ability to suppress glucagon secretion. PMID:627333

Dunbar, J C; Walsh, M F; Foà, P P

1978-01-14

329

The serum glucose response to glucagon suppression with somatostatin, insulin or antiglucagon serum in depancreatized rats  

Microsoft Academic Search

Summary  Total immunoreactive glucagon (IRG) and immunoreactive glucagon of A cell origin (IRGa) were measured in the serum of normal, sham-operated and depancreatized rats, after the administration of three glucagon antagonists: insulin (5–200 mU\\/rat\\/h), somatostatin (SRIF; 100 g\\/kg\\/h) and antiglucagon serum (AGS, enough to bind three times the calculated total amount of circulating IRG). Since no differences were noted between the

J. C. Dunbar; M. F. Walsh; P. P. Foà

1978-01-01

330

Aptamer-modified micro/nanostructured surfaces: efficient capture of Ramos cells in serum environment.  

PubMed

For potential applications in the isolation and enrichment of circulating tumor cells (CTCs), we have developed gold nanoparticle layers (GNPLs) of different roughness modified with TD05 aptamers (GNPL-APT). In serum-free binary cell mixtures containing Ramos cancer cells and CEM cells, the density of Ramos cells adherent to highly rough GNPL-APT was 19 times that of CEM cells. However, in serum-containing conditions, the specificity of GNPL-APT for Ramos cells was much reduced. To improve Ramos specificity in the presence of serum, we attached the TD05 aptamer to the layers via poly(oligo(ethylene glycol) methacrylate) (POEGMA) as an antifouling spacer (GNPL-POEGMA-APT). In serum-containing environment GNPL-POEGMA-APT showed an enhanced selectivity for Ramos cells, which increased with increasing surface roughness. The results of this study indicate that surfaces combining appropriate chemical composition and micro/nano roughness structures may be useful for cell separation, including the isolation of cancer cells for diagnosis. PMID:23540602

Wang, Yanyun; Zhou, Feng; Liu, Xiaoli; Yuan, Lin; Li, Dan; Wang, Yanwei; Chen, Hong

2013-04-17

331

Detection limits of organochlorine pesticides and related compounds in blood serum  

SciTech Connect

Determinations of organochlorine pesticides and similar chemical residues in blood serum have often reported detection limits of 1 ng/mL. When a study group has incurred body burdens lower than this, underestimates and misclassifications of exposure may occur because persons with pesticide residue concentration below the limit of detection are usually treated as zeros.' Thus in order to more accurately assess exposures in such populations, analysis of adipose tissue has been done. Recently, with TCDD, use of a sufficient volume of serum, as much as 0.5 L, in conjunction with appropriate analytical techniques has been shown to achieve detection limits necessary for epidemiological assessments, i.e., comparable to analysis of adipose tissue. In a population-based study involving children in which the authors were involved, it was not feasible to obtain specimens of either adipose or a large volume of serum. There was no compelling health motivation for such measures, nor did they wish to impair participation rates. Therefore, they chose to optimize the existing serum analysis, in order to achieve a detection limit low enough to assess reasonably the anticipated exposures.

Wolff, M.S.; Rivera, M.; Baker, D.B. (Mount Sinai School of Medicine, New York, NY (United States))

1991-10-01

332

Zinc determined in 10-microL serum or urine samples by flameless atomic absorption spectrometry.  

PubMed

We describe a precise flameless atomic absorption spectrometric method requiring only 10 microL of sample, which thus permits repeated measurements in the neonate. Standard curves covering the range of 0 to 30 mg of zinc per liter, with standards in various matrixes (albumin, glycerol, serum, or nitric acid) had slopes ranging from 0.49 to 1.17, relative to that for aqueous standards. We prepared low-zinc matrixes, which had slopes similar to that of serum, by dialyzing serum or a 50 g/L solution of albumin vs a buffered zinc-free dialysis fluid containing appropriate inorganic constituents. Use of thoroughly de-ionized water, reagent-grade chemicals, "ultrapure" nitric acid, specified disposable plastic ware, and appropriate pipet tip-rinsing techniques minimized extraneous contamination with zinc. Concentrations of zinc in serum calculated from a "rational-method" calibration algorithm fit to the standard curve agreed well with independent determinations by flame atomic absorption spectrometry. PMID:7449125

Vieira, N E; Hansen, J W

1981-01-01

333

BD Vacutainer Plus Plastic Serum Tubes with Clot Activator  

Center for Biologics Evaluation and Research (CBER)

... BD Vacutainer Plus Plastic Serum Tubes with Clot Activator. ... Product: BD Vacutainer Plus Plastic Serum Tubes with Clot Activator. Date: 05/05/2004. - ... More results from www.fda.gov/biologicsbloodvaccines/bloodbloodproducts/approvedproducts

334

Interaction of amphiphilic drugs with human and bovine serum albumins.  

PubMed

To know the interaction of amphiphilic drugs nortriptyline hydrochloride (NOT) and promazine hydrochloride (PMZ) with serum albumins (i.e., human serum albumin (HSA) and bovine serum albumin (BSA)), techniques of UV-visible, fluorescence, and circular dichroism (CD) spectroscopies are used. The binding affinity is more in case of PMZ with both the serum albumins. The quenching rate constant (k(q)) values suggest a static quenching process for all the drug-serum albumin interactions. The UV-visible results show that the change in protein conformation of PMZ-serum albumin interactions are more prominent as compared to NOT-serum albumin interactions. The CD results also explain the conformational changes in the serum albumins on binding with the drugs. The increment in %?-helical structure is slightly more for drug-BSA complexes as compared to drug-HSA complexes. PMID:22750346

Khan, Abbul Bashar; Khan, Javed Masood; Ali, Mohd Sajid; Khan, Rizwan Hasan; Kabir-Ud-Din

2012-06-07

335

Technical aspects and clinical correlations of the serum bactericidal test  

Microsoft Academic Search

A review of the studies using 50 % human serum as a diluent for the serum bactericidal test has shown correlations with patient outcome. Human serum used as diluent of the patient's serum appears to be essential because of high protein binding of some antibiotics. An inoculum of 105–106bacteria\\/ml and a bactericidal criteria of 99.9 % killing are technical aspects

H. C. Standiford; B. A. Tatem

1986-01-01

336

Three automated quantitative assays for serum proteins.  

PubMed

Three quantitative assays for detection of proteins are reported. One is an adaptation to the Auto-Analyzer of the widely used method of Lowry et al. In another procedure, the product of the reaction of proteins with a modified biuret reacts with the phosphomolybdic--phosphotungstic reagent of Folin and Ciocalteu. The third method, performed on hydrolyzed sample, is based on the measurement of proline (Pro) and the conversion of the Pro content into protein. The universal presence of proline in serum proteins suggested this assay. The values for total serum proteins as assayed by the three procedures are similar. The second and the third assay for proteins, described in this paper, can also be performed manually. Studies on interfering substances and their elimination as well as on the sensitivity of the assays are reported. PMID:7363455

Blumenkrantz, N

1980-02-01

337

Increased serum arginase activity in depressed patients.  

PubMed

1. Arginase, an important part of the arginine-regulating system modulates nitric oxide generation; a neuroregulatory agent, which has been implicated in various neuropathological conditions. 2. In this regard, the authors investigated the arginine-nitric oxide pathway by measuring serum arginase activity in drug free major (n=18) and minor depressed outpatients (n=12) and healthy control subjects (n=30) in order to make a contribution to the understanding of disease mechanism. 3. Major depressed patients were found to have significantly higher serum arginase activity compared to controls (p<0.001) and minor depressives (p=0.001). Moreover, there was significant positive correlation between arginase activity and severity of depression in patients (p<0.001). 4. Results suggest that the arginine-nitric oxide pathway is involved in depression. Enhanced arginase activity in major depressed patients possibly leading to a decrease in nitric oxide synthesis may contribute to the symptomatology of depression. PMID:10800745

Elgün, S; Kumbasar, H

2000-02-01

338

Serum paraproteins in chronic lymphocytic leukaemia.  

PubMed Central

The presence of paraproteins in the sera of 10 patients with chronic lymphocytic leukaemia (CLL) was investigated using immunoisoelectric focusing. Monoclonal immunoglobulins were found in nine of these 10 sera. Five sera contained a single monoclonal IgM paraprotein, one serum contained a single monoclonal IgG paraprotein, while three sera contained more than one monoclonal paraprotein--namely, IgM + IgD, IgM + IgG, and IgM + IgD + IgG. The results indicate that the malignant B cells of CLL may be at a later stage of differentiation than previously assumed and serum monoclonal immunoglobulin could be of value as a tumour marker. Images

Sinclair, D; Dagg, J H; Mowat, A M; Parrott, D M; Stott, D I

1984-01-01

339

Purification of NAD+ glycohydrolase from human serum  

PubMed Central

In the present study, NAD+ glycohydrolase was purified from serum samples collected from healthy individuals using ammonium sulfate fractionation, Affi-Gel blue (Cibacron Blue F3GA) affinity chromatography, Sephadex G-100 column chromatography and isoelectric focusing. The final step was followed by a second Sephadex G-100 column chromatography assay in order to remove the ampholytes from the isoelectric focusing step. In terms of enhancement of specific activity, the NAD+ glycohydrolase protein was purified ?480-fold, with a yield of 1% compared with the initial serum fraction. The purified fraction appeared to be homogeneous, with a molecular weight of 39 kDa, as revealed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis, and also corresponded to the soluble (monomeric) form of surface antigen CD38.

COSKUN, OZLEM; NURTEN, RUSTEM

2013-01-01

340

Serum progesterone in women with lactational amenorrhoea.  

PubMed

A cross-sectional study was conducted to detect the return of ovulation in 56 women with (LA) lactational amenorrhea ranging from 2-12 months. As serum progesterone of 5 ng/ml provides an indirect evidence of ovulation. It was estimated by radioimmunoassay in 4 blood samples collected weekly over a period of 1 month in all the women. 37 women showed persistently low values of progesterone ( 5 mg/ml) throughout the study period. The other 19 women had serum progesterone of 5 ng/ml in 1 or several samples. 13 of these women, however, continued to have LA beyond 1 month in spite of the detection of high circulating progesterone. The possibility of pregnancy was excluded in all of them. The endometrial refractoriness to the circulating steriods is proposed as a mechanism of persistent LA. PMID:7228173

Joshi, U M; Joseph, R; Adatia, A R; Choudhary, V N; Joshi, J V; Mehta, S; Hazari, K T

1980-10-01

341

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.

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

342

Serum angiotensin converting enzyme in pulmonary disease  

Microsoft Academic Search

Synthetic acylated tripeptides, which may or may not be radiolabelled, are generally used as substrates for measuring serum\\u000a angiotensin converting enzyme (SACE) activity. The capillary endothelial cells are the major source of SACE in normals and\\u000a certain diseased states, however Gaucher’s cells in Gaucher’s disease and epithelioid cells in granulomatous disorders, including\\u000a sarcoidosis, are the major source of enzyme in

P. K. Rohatgi

1982-01-01

343

Seasonal folate serum concentrations at different nutrition.  

PubMed

Folic acid (vitamin B9) rich sources are leafy green vegetables, legumes, whole grains, egg yolk, liver, and citrus fruit. In winter and early spring, there could be insufficient supply of vegetables and fruit and thus lower intake of folic acid and possible deficient folic acid blood concentrations. The aim of the study was to assess serum vitamin B9 concentrations depending on the season (the last third of winter - March, the last third of spring - May/June and the beginning of autumn - September) and different nutritional habits (apparently healthy adults non-smoking, non-obese 366 subjects; 204 persons of general population on traditional mixed diet; and 162 long-term lacto-ovo vegetarians). In general population group, the mean concentration of folate in March was low (narrowly above lower reference limit) with high incidence of deficient values - 31.5%. In May/ June vs. March was folate concentration significantly higher with deficient values in 13.2% of individuals. The highest serum values were observed in September with 11.1% of deficient values. In vegetarian vs. non-vegetarian group, significantly higher folate concentrations were found in each season with no deficient values. Folate and vitamin B12 are the regulators of homocysteinemia; plant food lacks of vitamin B12. The deficient folate serum values in March caused the mild hyperhomocysteinemia in 12.3% of individuals vs. only 5.9% and 4.8% of subjects in groups investigated in May/June and September. In spite of high folate concentrations in all investigations and no deficient value, 19.6-22.8% of vegetarians suffer from mild hyperhomocysteinemia as a consequence of deficient vitamin B12 concentrations in one quarter of subjects. As far as the general population is concerned, our findings suggest that winter and early spring are critical seasons in regards to optimal serum folate concentrations. PMID:23741898

Krajcovicová-Kudlácková, Marica; Valachovicová, Martina; Blazícek, Pavel

2013-03-01

344

Increased serum arginase activity in depressed patients  

Microsoft Academic Search

1.1. Arginase, an important part of the arginine-regulating system modulates nitric oxide generation; a neuroregulatory agent, which has been implicated in various neuropathological conditions.2.2. In this regard, the authors investigated the arginine-nitric oxide pathway by measuring serum arginase activity in drug free major (n=18) and minor depressed outpatients (n=12) and healthy control subjects (n=30) in order to make a contribution

Serenay Elgün; Hakan Kumbasar

2000-01-01

345

Staining and evaluation of serum lipoproteins  

Microsoft Academic Search

Summary  A simple and reliable method of prestaining lipoproteins using a solution of Sudan blue in propane 1:2 diol prior to paper\\u000a electrophoresis is described. Simultaneous examination of sera by prestaining and staining after electrophoresis indicate\\u000a that prestaining is a reliable method for investigating alpha and beta lipoproteins, but not for determining the neutral fat\\u000a present in the serum.\\u000a \\u000a A comparison

Robert G. McFarlane

1962-01-01

346

Serum biomarkers for Alzheimer's disease: Proteomic discovery  

Microsoft Academic Search

For Alzheimer's disease (AD), the most common neurodegenerative disease, there is no simple, cost-effective biomarker for disease identification. Using novel mass spectrometry (MS)-based techniques, and analysis of the albumin-enriched low molecular weight proteome, minute amounts of human serum were analyzed for the measurement of thousands of peptides and proteins in parallel. The mass spectrograms were then evaluated with a novel

Dwight C. German; Prem Gurnani; Animesh Nandi; Harold R. Garner; Wayne Fisher; Ramon Diaz-Arrastia; Padraig O'Suilleabhain; Kevin P. Rosenblatt

2007-01-01

347

Clinical implications of serum digoxin concentrations  

Microsoft Academic Search

Summary Factors influencing serum digoxin concentrations, and the relation of these levels to classical electrocardiographic (ECG) and clinical manifestations of toxicity, were assessed in a series of 463 consecutively hospitalized patients of mean age 58 years. The majority of patients were receiving beta-acetyldigoxin or beta-methyldigoxin. Age, sex, creatinine clearance, and weight-corrected dose collectively explained less than 7% of overall variability

H. R. Ochs; D. J. Greenblatt; J. S. Harmatz; G. Bodem; H. J. Dengler

1981-01-01

348

Serum concentration of visfatin in obese women  

Microsoft Academic Search

The aim of the present study was to determine serum concentrations of visfatin in obese women in comparison to normal-weight controls. Study subjects were 21 obese women without additional disease (age, 29.0 ± 4.9 years; body mass index, 37.1 ± 6.1 kg\\/m2) and 16 healthy, normal-weight women (age, 29.9 ± 5.4 years; body mass index, 22.5 ± 1.7 kg\\/m2). Body

Barbara Zahorska-Markiewicz; Magdalena Olszanecka-Glinianowicz; Joanna Janowska; Piotr Koce?ak; El?bieta Semik-Grabarczyk; Micha? Holecki; Piotr D?browski; Anna Skorupa

2007-01-01

349

Serum retinol and risk of prostate cancer.  

PubMed

Greater exposure to retinol (vitamin A) may prevent prostate cancer, although under some conditions it could promote cell growth and de-differentiation. The authors prospectively examined prostate cancer risk and serum retinol levels, measured by using high-performance liquid chromatography, at baseline (n = 29,104) and after 3 years (n = 22,843) in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study cohort. Cox proportional hazards models were used to estimate the relative risk of total (n = 2,041) and aggressive (n = 461) prostate cancer by quintiles of baseline and 3-year serum retinol concentrations and by change in serum retinol levels from baseline to 3 years. Men with higher retinol concentrations at baseline were more likely to develop prostate cancer (quintile 5 vs. quintile 1 hazard ratio = 1.19, 95% confidence interval: 1.03, 1.36; P(trend) = 0.009). The results were similar for aggressive disease. Joint categorization based on baseline and 3-year retinol levels showed that men who were in the highest quintile at both time points had the greatest increased risk (baseline/3-year quintile 5/quintile 5 vs. quintile 1/quintile 1 hazard ratio = 1.31, 95% confidence interval: 1.08, 1.59). In this largest study to date of vitamin A status and subsequent risk of prostate cancer, higher serum retinol was associated with elevated risk, with sustained high exposure conferring the greatest risk. Future studies may clarify the underlying biologic mechanisms of the retinol-prostate cancer association. PMID:21389041

Mondul, Alison M; Watters, Joanne L; Männistö, Satu; Weinstein, Stephanie J; Snyder, Kirk; Virtamo, Jarmo; Albanes, Demetrius

2011-03-09

350

Serum Retinol and Risk of Prostate Cancer  

PubMed Central

Greater exposure to retinol (vitamin A) may prevent prostate cancer, although under some conditions it could promote cell growth and de-differentiation. The authors prospectively examined prostate cancer risk and serum retinol levels, measured by using high-performance liquid chromatography, at baseline (n = 29,104) and after 3 years (n = 22,843) in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study cohort. Cox proportional hazards models were used to estimate the relative risk of total (n = 2,041) and aggressive (n = 461) prostate cancer by quintiles of baseline and 3-year serum retinol concentrations and by change in serum retinol levels from baseline to 3 years. Men with higher retinol concentrations at baseline were more likely to develop prostate cancer (quintile 5 vs. quintile 1 hazard ratio = 1.19, 95% confidence interval: 1.03, 1.36; Ptrend = 0.009). The results were similar for aggressive disease. Joint categorization based on baseline and 3-year retinol levels showed that men who were in the highest quintile at both time points had the greatest increased risk (baseline/3-year quintile 5/quintile 5 vs. quintile 1/quintile 1 hazard ratio = 1.31, 95% confidence interval: 1.08, 1.59). In this largest study to date of vitamin A status and subsequent risk of prostate cancer, higher serum retinol was associated with elevated risk, with sustained high exposure conferring the greatest risk. Future studies may clarify the underlying biologic mechanisms of the retinol-prostate cancer association.

Mondul, Alison M.; Watters, Joanne L.; Mannisto, Satu; Weinstein, Stephanie J.; Snyder, Kirk; Virtamo, Jarmo; Albanes, Demetrius

2011-01-01

351

Serum positive botulism with neuropathic features.  

PubMed

A 32-year-old man presented with multiple cranial neuropathies and his serum was positive for botulism type B. However, serial electrodiagnostic studies were consistent with a primarily neuropathic process, such as Fisher syndrome, rather than a neuromuscular junction disorder. Electrodiagnostic study findings in patients with presumed neuromuscular junction disorders may mimic findings suggestive of a neuropathic process, or the bioassay for botulism may be falsely positive in patients with Fisher Syndrome. PMID:10638887

Chang, V H; Robinson, L R

2000-01-01

352

Interaction of taxol with human serum albumin  

Microsoft Academic Search

Taxol (paclitaxel) is an anticancer drug, which interacts with microtuble proteins, in a manner that catalyzes their formation from tubulin and stabilizes the resulting structures (Nogales et al., Nature 375 (1995) 424–427). This study was designed to examine the interaction of taxol with human serum albumin (HSA) in aqueous solution at physiological pH with drug concentrations of 0.0001–0.1 mM, and

M. Purcell; J. F. Neault; H. A. Tajmir-Riahi

2000-01-01

353

Serum antioxidant vitamins and risk of cataract  

Microsoft Academic Search

OBJECTIVE--To investigate serum concentrations of alpha tocopherol, beta carotene, retinol, and selenium for their prediction of end stage cataract. DESIGN--A case-control study, nested within a cohort study, based on the linkage of records of subjects aged 40-83 from a health survey with those from the national Finnish hospital discharge register. SUBJECTS--47 patients admitted to ophthalmological wards for senile cataract over

P. Knekt; M. Heliövaara; A. Rissanen; A. Aromaa; R. K. Aaran

1992-01-01

354

Serum electrolytes in hospitalized pellagra alcoholics  

Microsoft Academic Search

Background: Owing to high diarrhoea and protein malnutrition frequencies in pellagra, we hypothesised that pellagra patients would have higher electrolyte disturbances than non-pellagra alcoholics.Objective: To compare serum electrolytes of hospitalised alcoholics with or without pellagra.Design: Retrospective and descriptive case-control study.Setting: Internal Medicine wards at a University Hospital, Medical School of Uberaba, Brazil.Subjects: Medical records were reviewed to obtain relevant clinical

DF Cunha; JP Monteiro; LS Ortega; LG Alves; SFC Cunha

2000-01-01

355

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

356

SURFACE TENSION OF SERUM OF THE SENSITIZED GUINEA PIG  

PubMed Central

The primary change in surface tension of serum incident to anaphylactic shock is probably due to a lowering of the surface tension of the serum by the addition of the antigen serum. But this may be followed by further decrease or by an increase depending on the intensity and duration of certain secondary tissue changes.

Ramsdell, Susan Griffith

1928-01-01

357

Serum screening for oncogene proteins in workers exposed to PCBs  

Microsoft Academic Search

A cohort of 16 municipal workers engaged in cleaning oil from old transformers was examined for possible health effects from exposure to polychlorinated biphenyls (PCBs). In addition to the evaluation of routine clinical parameters (history, physical examination, liver function tests, serum triglycerides, serum PCB values), a new screening technique for the presence of oncogene proteins in serum using monoclonal antibodies

P W Brandt-Rauf; H L Niman

1988-01-01

358

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

359

BILIARY LIPIDS SUPPORT SERUM-FREE GROWTH OF 'GIARDIA LAMBLIA'  

EPA Science Inventory

Giardia lamblia has only been grown in vitro in media containing serum or serum fractions. How this pathogen can grow in the human small intestinal lumen without serum is not known. The authors found that samples of human hepatic or gall bladder bile maintained G. lamblia surviva...

360

Serum Pancreatic Enzyme Concentrations in Chronic Viral Liver Diseases  

Microsoft Academic Search

Serum amylase and lipase concentrations weredetermined in 78 patients with chronic liver diseases[26 chronic active hepatitis (CAH) and 52 livercirrhosis] and in 15 healthy subjects. Pancreaticisoamylase concentrations and macroamylase complexes wereassayed in hyperamylasemic sera. Serum amylase levelswere abnormally elevated in 27 patients (35%; 22 livercirrhosis, 5 CAH), whereas serum lipase levels were elevated in 16 patients (21%; 15 livercirrhosis, 1

Raffaele Pezzilli; Pietro Andreone; Antonio Maria Morselli-Labate; Claudia Sama; Paola Billi; Carmela Cursaro; Bahjat Barakat; Annagiulia Gramenzi; Manuela Fiocchi; Federico Miglio; Mauro Bernardi

1999-01-01

361

Changes of Serum Growth Hormone in Psychosomatic Disorders  

Microsoft Academic Search

The authors have measured serum growth hormone (GH) in various psychosomatic disorders by a radioimmunoassay technique, and have obtained the following results. (1)The resting levels of serum GH in anorexia nervosa were high in 14 of 20 cases. The response of GH secretion to induced hypoglycemia was abnormal in some cases of anorexia nervosa. (2) Serum GH in depressive patients

Hiroyuki Suematsu; Nobuo Kurokawa; Hajime Tamai; Yujiro Ikemi

1974-01-01

362

Relation Between Micellar and Serum Casein in Bovine Milk1  

Microsoft Academic Search

Little or no additional casein dissolved when milk was diluted with large volumes of milk dialysate. Some dissolution of mi- cellar to serum casein occurred when sedi- mented micelles were redispersed in ultra- filtrate mechanically, but the concentration of serum casein remained far below that of the original milk. It is concluded that micellar and serum casein do not form

Dyson Rose

1968-01-01

363

Alterations in Serum Leptin in Chronic Liver Disease  

Microsoft Academic Search

The role of leptin in anorexia associated with liver cirrhosis remains controversial. The aim of this study was to quantify the serum leptin level in patients with hepatocellular or cholestatic liver disease and to assess its relationship with serum insulin, body mass index, and serum lipoproteins. The study population included 30 women, 15 with chronic hepatocellular liver disease and 15

Ziv Ben-Ari; Zahava Schafer; Jaqueline Sulkes; Varda Manhaim; Ran Tur-Kaspa; Menahem Fainaru

2002-01-01

364

Fatty acyltranferases in serum in cystic fibrosis (CF) patients  

Microsoft Academic Search

Studies on serum and gastrointestinal secretion from CF patient is suggest that defective accumulation of mucus in gastrointestinal tract and excessive amount of a protease resistant peptides in serum are related to the abnormal activity of enzymes responsible for fatty acylation of proteins. Here, the authors investigated the fatty acyltransferase activities in serum of normal and CF patients. A 15

J. Zielenski; L. J. Newman; B. L. Slomiany; A. Slomiany

1987-01-01

365

Urban pollution and nickel concentration in serum.  

PubMed

The study's objective has been to evaluate whether urban pollution, here nickel compounds and metallic nickel (Ni) are present, could determine serum concentrations of the above mentioned metal. Out of a population of 394 Municipal Police employees, subjects with main confounding factors were eliminated. The remaining subjects were made comparable for sex, age, and length of employment. Thus, 160 subjects were included in the study: 80 traffic policemen (42 men and 38 women) with outdoor activity exposed to urban pollutants in a direct way, and 80 administrative workers (42 men and 38 women) with indoor unexposed activity. The results obtained in the studied population demonstrate that in traffic policemen the serum levels of Ni are more elevated than those in administrative workers; both in male and female workers. The authors hypothesise that the presence of Ni as fuel additive in lead free fuels and as catalyser in catalytic exhausts, which have been obligatory in Italy in new cars for the last 10 years, could be one of the causes for the increased serum levels of the above mentioned metal in traffic policemen. PMID:14660119

Tomei, Francesco; Rosati, Maria Valeria; Ciarrocca, Manuela; Marchetti, Maria Rosaria; Baccolo, Tiziana Paola; Anzelmo, Vincenza; Tomao, Enrico

2004-02-01

366

Mammographic breast density and serum phytoestrogen levels.  

PubMed

Some forms of estrogen are associated with breast cancer risk as well as with mammographic density (MD), a strong marker of breast cancer risk. Whether phytoestrogen intake affects breast density, however, remains unclear. We evaluated the association between serum levels of phytoestrogens and MD in postmenopausal women. We enrolled 269 women, ages 55-70 yr, who received a screening mammogram and had no history of postmenopausal hormone use. Subjects completed a survey on diet and factors related to MD and provided a blood sample for analysis of 3 phytoestrogens: genistein, daidzein, and coumestrol. We examined whether mean percent MD was related to serum level of phytoestrogens, adjusting for age and body mass index. Genistein and daidzein levels correlated with self-reported soy consumption. Mean percent MD did not differ across women with different phytoestrogen levels. For example, women with nondetectable genistein levels had mean density of 11.0% [95% confidence intervals (CI) = 9.9-12.4], compared to 10.5% (95% CI = 8.0-13.7) and 11.2% (95% CI = 8.7-14.6) for < and ? median detectable levels, respectively. In a population with relatively low soy intake, serum phytoestrogens were not associated with mammographic density. Additional studies are needed to determine effects of higher levels, particularly given patterns of increasing phytoestrogen intake. PMID:22860715

Lowry, Sarah J; Sprague, Brian L; Aiello Bowles, Erin J; Hedman, Curtis J; Hemming, Jocelyn; Hampton, John M; Burnside, Elizabeth S; Sisney, Gale A; Buist, Diana S M; Trentham-Dietz, Amy

2012-08-03

367

Rye bread decreases serum total and LDL cholesterol in men with moderately elevated serum cholesterol.  

PubMed

The objective of this study was to determine the hypocholesterolemic effects of whole meal rye and white wheat breads in healthy humans with elevated serum cholesterol concentrations, and the changes in plasma glucose and insulin concentrations during rye and wheat bread periods. The subjects were 18 men and 22 women with baseline serum cholesterol concentration of 6.4+/-0.2 mmol/L. The study design was a 2x4-wk crossover trial during which each subject randomly consumed rye and wheat breads (20% of daily energy) as part of their usual diet for 4 wk. The bread periods were separated by a 4-wk washout period. Blood samples (after fasting) were collected on two consecutive days at the beginning and end of the bread periods. Serum total cholesterol decreased by 8% (P = 0.002) in men but was not significantly altered in women during the rye bread period. The wheat bread period did not affect any of the variables studied. Analysis of the serum lipids in tertiles of rye bread consumption confirmed the reduction in total cholesterol (P = 0.048) in men and revealed the reduction in LDL cholesterol (P = 0.032); both were dependent on the amount of rye bread consumed (-2, -14 and -10% in total cholesterol and 0, -12 and -12% in LDL cholesterol). Neither rye nor wheat bread influenced the concentrations of glucose and insulin. In conclusion, rye bread is effective in reducing serum total and LDL cholesterol concentrations in men with elevated serum cholesterol. Good compliance with consuming a relatively large amount of rye bread in the usual diet indicates that rye bread offers a practical dietary means of reducing serum cholesterol in men. PMID:10720164

Leinonen, K S; Poutanen, K S; Mykkänen, H M

2000-02-01

368

[Effect of diet therapy on the serum immunoglobulin level in chronic eczema].  

PubMed

A group of 23 patients with acute chronic eczema received hypoallergenic diet providing for maximal exclusion of obligate allergens, extractive and aromatizing substances and food additives, with this diet being full value as to the chemical, vitamin and trace element content. In the diet applied, sugar was completely replaced by xylite, table salt was excluded and liquid restricted. The dietetic management was carried out under the control over the clinical picture of the skin status and the time course of changes in serum concentrations of IgA, IgM, IgG and IgE. The results indicate that adequate dietetic management of patients with acute chronic eczema leads to a significant decrease in serum concentrations of IgE, stabilization and partial regression of skin manifestations. PMID:7090319

Samsonov, M A; Kalinina, A A

369

Lean and Chemicals Toolkit.  

National Technical Information Service (NTIS)

This Lean and Chemicals Toolkit describes practical strategies for using Lean manufacturingthe production system developed by Toyotato reduce chemical wastes while improving the operational and environmental performance of manufacturing and industrial bus...

2009-01-01

370

The Chemical Equilibrium Problem.  

National Technical Information Service (NTIS)

It has long been known that the problem of determining the equilibrium composition of a solution of chemically reacting species could be formulated as a constrained minimum problem. Previous methods for solving the chemical equilibrium problem in this for...

J. H. Bigelow

1968-01-01

371

Tobacco and chemicals (image)  

MedlinePLUS

Some of the chemicals associated with tobacco smoke include ammonia, carbon dioxide, carbon monoxide, propane, methane, acetone, hydrogen cyanide and various carcinogens. Other chemicals that are associated with chewing ...

372

Alternatives in Chemical Education  

ERIC Educational Resources Information Center

|Summarizes the educational objectives and strategies of the Chemical Technician Curriculum Project (Chem TeC), which has the primary objective of preparing a set of texts specifically for training chemical technicians. (PR)|

Pecsok, Robert L.

1971-01-01

373

Chemical Reactions (Netorials)  

NSDL National Science Digital Library

Chemical Reactions: this is a resource in the collection "Netorials". The Netorials cover selected topics in first-year chemistry including: Chemical Reactions, Stoichiometry, Thermodynamics, Intermolecular Forces, Acids & Bases, Biomolecules, and Electrochemistry.

374

Physical vs Chemical Changes  

NSDL National Science Digital Library

The phenomena are physical changes, including the crushing of a can, melting of ice, and melting of sugar, and chemical changes, including and the rusting of iron and burning of sugar. This analysis will address the chemical change component.

375

Advanced Chemical Propulsion Study.  

National Technical Information Service (NTIS)

A study was performed of advanced chemical propulsion technology application to space science (Code S) missions. The purpose was to begin the process of selecting chemical propulsion technology advancement activities that would provide greatest benefits t...

G. Woodcock D. Byers L. A. Alexander A. Krebsbach

2004-01-01

376

Children and Dairy Chemicals  

MedlinePLUS

Children & Dairy Chemicals Chemicals used to clean dairy facilities and equipment, especially dairy pipeline cleaners, pose a special risk for children. Rapid medical assessment and treatment is critical in preventing long ...

377

Chemical Structural Aging Effects.  

National Technical Information Service (NTIS)

This program is determining the individual chemical rate processes that govern the aging of ANB-3066 propellant, and it is attempting to establish the effect of chemical (compositional) changes upon the system's mechanical response to enable better utiliz...

G. E. Myers A. B. Tipton

1972-01-01

378

Serum- and substratum-dependent modulation of neuritic growth.  

PubMed

Explants of embryonic day 8 (E8) chicken dorsal root ganglia (DRG) have been cultured with medium containing serum or the serum-free supplement N1 on one of three substrata: collagen, polyornithine (PORN), or PORN exposed to a polyornithine-binding neurite-promoting factor (PNPF-PORN). Replicate cultures were maintained with or without nerve growth factor (NGF). NGF elicited its classical neuritic outgrowth on all three substrata in serum-containing or serum-free medium. In the absence of NGF, however, a gradation of increasing neurite growth was seen with: PNPF-PORN greater than PORN greater than collagen. This response occurred in both media. In addition, the neuritic halo in each instance was markedly more developed in the absence of serum, especially on PNPF-PORN. Nonneuronal behaviors reflected both serum and substratum influences: thus, nonneuronal outgrowth consisted mainly of flat cells with serum and collagen, was nonexistent with serum and PORN or PNPF-PORN, and involved mostly Schwann-like scattered cells in the absence of serum on any one substratum. The serum-dependent behaviors of ganglionic neurites were examined further with explants from chicken E11 sympathetic ganglia. A single substratum was used (PORN), without exogenous trophic factor. Neurite outgrowth was depressed by the presence of fetal calf serum, thus supporting the generality of this phenomenon. Lastly, PC12 cells, a clonal line of rat pheochromocytoma, will grow neurites in the presence of NGF after 48 hr in serum-free, but not serum-containing media. Addition of serum to serum-free cultures at this time results in the rapid and complete retraction of neurites. PMID:6876195

Skaper, S D; Selak, I; Varon, S

1983-01-01

379

Partition of Environmental Chemicals between Maternal and Fetal Blood and Tissues  

PubMed Central

Passage of environmental chemicals across the placenta has important toxicological consequences, as well as for choosing samples for analysis and for interpreting the results. To obtain systematic data, we collected in 2000 maternal and cord blood, cord tissue, placenta, and milk in connection with births in the Faroe Islands, where exposures to marine contaminants is increased. In 15 sample sets, we measured a total of 87 environmental chemicals, almost all of which were detected both in maternal and fetal tissues. The maternal serum lipid-based concentrations of organohalogen compounds averaged 1.7 times those of cord serum, 2.8 times those of cord tissue and placenta, and 0.7 those of milk. For organohalogen compounds detectable in all matrices, a high degree of correlation between concentrations in maternal serum and the other tissues investigated was generally observed (r2 > 0.5). Greater degree of chlorination resulted in lower transfer from maternal serum into milk. Concentrations of pentachlorbenzene, ?-hexachlorocyclohexane, and several polychlorinated biphenyl congeners with low chlorination were higher in fetal samples and showed poor correlation with maternal levels. Perfluorinated compounds occurred in lower concentrations in cord serum than in maternal serum. Cadmium, lead, mercury, and selenium were all detected in fetal samples, but only mercury showed close correlations among concentrations in different matrices. Although the environmental chemicals examined pass through the placenta and are excreted into milk, partitions between maternal and fetal samples are not uniform.

2010-01-01

380

Physical and Chemical Change  

NSDL National Science Digital Library

Overview of physical and chemical changes with practice activities and a quiz. Worksheet - Physical Chemical Change Worksheet After viewing the worksheet, copy and paste it into a new blank Google Document - MyDSD Google Login Title your Document "Chemical and Physical Change". Make sure to include your name and period in the body of the doc. The answers in your document should be a different color or font. Examples of Chemical Changes Changes info page More Examples After completing the rest ...

Wood, Mr.

2010-11-15

381

Chemical Synthesis Database  

NSDL National Science Digital Library

This database provides information on thousands of chemical compounds, including synthesis references and physical properties. The database is searchable by keyword and browseable by journal title. For each compound, the information includes molecular formula and weight, Chemical Abstracts Service (CAS) numbers, International Chemical Identifier (InChIKey), and Simplified Molecular Input Line Entry System (SMILES) notation. There is also information on synonyms, physical properties (boiling and melting points, density), an illustration of chemical structure, spectral data, and links to additional data.

382

Chemical of the Week  

NSDL National Science Digital Library

Professor Bassam Z. Shakhashiri at the University of Wisconsin-Madison adds a new chemical to this page every week. The site was created for his general chemistry courses, Chem 103 and Chem 104, to increase students' knowledge about various chemicals and their use. Users can view featured chemicals from the currently updated fall course (103) or from the spring course (104). The chemicals featured thus far include: lime, methane, uranium, the chemistry of autumn colors, and gases that emit light.

Shakhashiri, Bassam Z.

1997-01-01

383

The elusive chemical potential  

NSDL National Science Digital Library

The author offers some qualitative understanding of the chemical potential, a topic that students invariably find difficult. Three "meanings" for the chemical potential are stated and then supported by analytical development. Two substantial applications â depression of the melting point and batteries â illustrate the chemical potential in action. The origin of the term "chemical potential" has its surprises, and a sketch of the history is given.variable particle number.

Baierlein, Ralph

2011-08-31

384

Genome-Wide Association Studies of Serum Magnesium, Potassium, and Sodium Concentrations Identify Six Loci Influencing Serum Magnesium Levels  

Microsoft Academic Search

Magnesium, potassium, and sodium, cations commonly measured in serum, are involved in many physiological processes including energy metabolism, nerve and muscle function, signal transduction, and fluid and blood pressure regulation. To evaluate the contribution of common genetic variation to normal physiologic variation in serum concentrations of these cations, we conducted genome-wide association studies of serum magnesium, potassium, and sodium concentrations

Tamra E. Meyer; Germaine C. Verwoert; Shih-Jen Hwang; Nicole L. Glazer; Albert V. Smith; Frank J. A. van Rooij; Georg B. Ehret; Eric Boerwinkle; Janine F. Felix; Tennille S. Leak; Tamara B. Harris; Qiong Yang; Abbas Dehghan; Thor Aspelund; Ronit Katz; Georg Homuth; Thomas Kocher; Rainer Rettig; Janina S. Ried; Christian Gieger; Hanna Prucha; Arne Pfeufer; Thomas Meitinger; Josef Coresh; Albert Hofman; Mark J. Sarnak; Yii-Der Ida Chen; André G. Uitterlinden; Aravinda Chakravarti; Bruce M. Psaty; Cornelia M. van Duijn; W. H. Linda Kao; Jacqueline C. M. Witteman; Vilmundur Gudnason; David S. Siscovick; Caroline S. Fox; Anna Köttgen

2010-01-01

385

Antimüllerian hormone as a serum marker of granulosa cell tumors of the ovary: Comparative study with serum ?-inhibin and estradiol  

Microsoft Academic Search

OBJECTIVE: Our purpose was to evaluate serum antimüllerian hormone as a marker for granulosa cell tumors. STUDY DESIGN: Serum antimüllerian hormone concentrations were determined in 16 patients with an adult-type granulosa cell tumor; in female patients with ovarian adenocarcinoma, benign ovarian cysts, or extraovarian cancers; and in normal premenopausal and postmenopausal women. Serum antimüllerian hormone, ?-inhibin, and estradiol levels were

Rodolfo A. Rey; Catherine Lhommé; Isabelle Marcillac; Najiba Lahlou; Pierre Duvillard; Nathalie Josso; Jean M. Bidart

1996-01-01

386

Lake Michigan fish consumption as a source of polychlorinated biphenyls in human cord serum, maternal serum, and milk  

Microsoft Academic Search

Reported consumption of Lake Michigan sport fish was examined in relation to the levels of polychlorinated biphenyls (PCBs) in biological samples provided by a sample of maternity patients. Fish consumption was correlated with PCB levels in maternal serum and milk but not in cord serum. PCB levels in serum increased with age, but were unrelated to social class, parity, or

P. M. Schwartz; S. W. Jacobson; G. Fein; J. L. Jacobson; H. A. Price

1983-01-01

387

Rat ?-Fetoprotein binding affinities of a large set of structurally diverse chemicals elucidated the relationships between structures and binding affinities.  

PubMed

Endocrine disrupting chemicals interfere with the endocrine system in animals, including humans, to exert adverse effects. One of the mechanisms of endocrine disruption is through the binding of receptors such as the estrogen receptor (ER) in target cells. The concentration of any chemical in serum is important for its entry into the target cells to bind the receptors. ?-Fetoprotein (AFP) is a major transport protein in rodent serum that can bind with estrogens and thus change a chemical's availability for entrance into the target cell. Sequestration of an estrogen in the serum can alter the chemical's potential for disrupting estrogen receptor-mediated responses. To better understand endocrine disruption, we developed a competitive binding assay using rat amniotic fluid, which contains very high levels of AFP, and measured the binding to the rat AFP for 125 structurally diverse chemicals, most of which are known to bind ER. Fifty-three chemicals were able to bind the rat AFP in the assay, while 72 chemicals were determined to be nonbinders. Observations from closely examining the relationship between the binding data and structures of the tested chemicals are rationally explained in a manner consistent with proposed binding regions of rat AFP in the literature. The data reported here represent the largest data set of structurally diverse chemicals tested for rat AFP binding. The data assist in elucidating binding interactions and mechanisms between chemicals and rat AFP and, in turn, assist in the evaluation of the endocrine disrupting potential of chemicals. PMID:23013281

Hong, Huixiao; Branham, William S; Dial, Stacey L; Moland, Carrie L; Fang, Hong; Shen, Jie; Perkins, Roger; Sheehan, Daniel; Tong, Weida

2012-10-12

388

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.

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

389

Principles of Chemical Programming  

Microsoft Academic Search

The chemical reaction metaphor describes computation in terms of a chemical solu- tion in which molecules interact freely according to reaction rules. Chemical models use the multiset as their basic data structure. Computation proceeds by rewritings of the multiset which consume elements according to reaction conditions and pro- duce new elements according to specific transformation rules. Since the introduction of

Jean-pierre Banâtre; Pascal Fradet; Yann Radenac

2005-01-01

390

Principles of Chemical Programming  

Microsoft Academic Search

The chemical reaction metaphor describes computation in terms of a chemical solu- tion in which molecules interact freely according to reaction rules. Chemical models use the multiset as their basic data structure. Computation proceeds by rewritings of the multiset which consume elements according to reaction conditions and pro- duce new elements according to specic transformation rules. Since the introduction of

Jean-Pierre Ban; Pascal Fradet; Yann Radenac; Campus de Beaulieu

2004-01-01

391

Biological and Chemical Security  

Microsoft Academic Search

The LLNL Chemical & Biological National Security Program (CBNP) provides science, technology and integrated systems for chemical and biological security. Our approach is to develop and field advanced strategies that dramatically improve the nation's capabilities to prevent, prepare for, detect, and respond to terrorist use of chemical or biological weapons. Recent events show the importance of civilian defense against terrorism.

Fitch

2002-01-01

392

Toxicology and Chemical Safety.  

ERIC Educational Resources Information Center

Topics addressed in this discussion of toxicology and chemical safety include routes of exposure, dose/response relationships, action of toxic substances, and effects of exposure to chemicals. Specific examples are used to illustrate the principles discussed. Suggests prudence in handling any chemicals, whether or not toxicity is known. (JN)

Hall, Stephen K.

1983-01-01

393

Chemical Plume Source Localization  

Microsoft Academic Search

This paper addresses the problem of estimating a likelihood map for the location of the source of a chemical plume using an autonomous vehicle as a sensor probe in a fluid flow. The fluid flow is assumed to have a high Reynolds number. Therefore, the dispersion of the chemical is dominated by turbulence, resulting in an intermittent chemical signal. The

Shuo Pang; Jay A. Farrell

2006-01-01

394

Chemical warfare agents  

Microsoft Academic Search

Chemical warfare agents (CWA's) are defined as any chemical substance whose toxic properties are utilised to kill, injure or incapacitate an enemy in warfare and associated military operations. Chemical agents have been used in war since times immemorial, but their use reached a peak during World War I. During World War II only the Germans used them in the infamous

S. Chauhan; R. D’Cruz; S. Faruqi; K. K. Singh; S. Varma; M. Singh; V. Karthik

2008-01-01

395

Toxicology and Chemical Safety.  

ERIC Educational Resources Information Center

|Topics addressed in this discussion of toxicology and chemical safety include routes of exposure, dose/response relationships, action of toxic substances, and effects of exposure to chemicals. Specific examples are used to illustrate the principles discussed. Suggests prudence in handling any chemicals, whether or not toxicity is known. (JN)|

Hall, Stephen K.

1983-01-01

396

More on Chemical Changes  

NSDL National Science Digital Library

The phenomenon is a series of chemical reactions and observation of signs of a chemical change. The laboratory activities can be done by students or as a teacher demonstration. They involve mixing chemicals and noting color change, formation of a precipitate, and production of a gas.

397

Chemical etching of aluminium  

Microsoft Academic Search

Chemical etching is employed as micromachining manufacturing process to produce micron-size components. The process applies a strong chemical etchant solution to remove unwanted part in the workpiece material. It is basically a corrosion-controlled process. Chemical etching process has a long history and accepted one of the important nontraditional machining processes during the last half century. The method is widely applied

O. Çak?r

2008-01-01

398

Adaptability in Chemical Engineering.  

National Technical Information Service (NTIS)

The adaptability issue for chemical engineering (the ability of chemical engineers to be retrained to work in other fields and for those from other fields to be retrained for work in chemical engineering) will be discussed and illustrated in terms of (1) ...

J. S. Watson

1989-01-01

399

Serum and tear immunoglobulin levels in acute adenovirus conjunctivitis.  

PubMed Central

Tear and serum IgG, IgA, and IgM levels were measured in 35 healthy subjects and 31 patients with acute conjunctivitis due to adenovirus 2, 7, and 8 infections. Serum IgG and IgM levels were found to be significantly low and there was no change in the serum IgA level. There was a significant rise in the tear IgG level. A progressive decline in the serum immunoglobulin level with the severity of the disease was observed. The changes in the immunoglobulin levels in serum and tears showed a tendency to reach normal levels with clinical improvement.

Gupta, A K; Sarin, G S

1983-01-01

400

Influence of serum on in situ proliferation and genotoxicity in A549 human lung cells exposed to nanomaterials.  

PubMed

In this work in situ proliferation of A549 human lung epithelial carcinoma cells exposed to nanomaterials (NMs) was investigated in the presence or absence of 10% serum. NMs were selected based on chemical composition, size, charge and shape (Lys-SiO(2), TiO(2), ZnO, and multi walled carbon nanotubes, MWCNTs). Cells were treated with NMs and 4h later, cytochalasin-B was added. 36 h later, cell morphology was analyzed under a light microscope. Nuclearity was scored to determine the cytokinesis-block proliferation index (CBPI). CBPI, based on percentage of mono-, bi- and multi-nucleated cells, reflects cell toxicity and cell cycle delay. For some conditions depending on NM type (TiO(2) and MWCNT) and serum concentration (0%) scoring of CBPI was impossible due to overload of agglomerated NMs. Moreover, where heavy agglomeration occurs, micronuclei (MN) detection and scoring under microscope was prevented. A statistically significant decrease of CBPI was found for ZnO NM suspended in medium in the absence or presence of 10% serum at 25 ?g/ml and 50 ?g/ml, respectively and for Lys-SiO(2) NM at 3.5 ?g/ml in 0% serum. Increase in MN frequency was observed in cells treated in 10% serum with 50 ?g/ml ZnO. In 0% serum, the concentrations tested led to high toxicity. No genotoxic effects were induced by Lys-SiO(2) both in the absence or presence of serum up to 5 ?g/ml. No toxicity was detected for TiO(2) and MWCNTs in both 10% and 0% serum, up to the dose of 250 ?g/ml. Restoration of CBPI comparable to untreated control was shown for cells cultured without serum and treated with 5 ?g/ml of Lys-SiO(2) NM pre-incubated in 100% serum. This observation confirms the protective effect of serum on Lys-SiO(2) NM cell toxicity. In conclusion in situ CBPI is proposed as a simple preliminary assay to assess both NMs induced cell toxicity and feasibility of MN scoring under microscope. PMID:22027682

Corradi, Sara; Gonzalez, Laetitia; Thomassen, Leen C J; Bilani?ová, Dagmar; Birkedal, Renie K; Pojana, Giulio; Marcomini, Antonio; Jensen, Keld A; Leyns, Luc; Kirsch-Volders, Micheline

2011-10-19

401

Effect of oral glucose on serum zinc in the elderly  

SciTech Connect

To determine the effect of glucose loading on serum zinc concentrations, 34 elderly subjects aged 60-86 y were studied. Anthropometric data, medical and dietary histories were obtained. Serum zinc and glucose concentrations were obtained fasting and 1/2, 1, 1 1/2, 2 and 3 h after 75 g oral glucose load; glycohemoglobin and fasting serum lipids were also determined. For comparison, the subjects were categorized as: normal or low serum zinc concentrations; normal or high body mass index BMI; normal or high sum of skinfolds and normal or high serum cholesterol. Results showed that low serum zinc concentrations increased significantly over baseline values after the glucose load and did not return to fasting levels. On the other hand, mean serum zinc concentrations significantly declined without recovery for those with normal zinc values. For the total group, no significant differences were noted between fasting values and subsequent time periods. No correlations were noted between fasting serum zinc and area under the curve for zinc except in the high BMI group (positive correlation observed). For the high BMI group, fasting serum zinc differed significantly from the succeeding measurements except for 30 min. For the group as a whole, mean serum zinc concentration was within normal limits (76.9 +/- 2.8 mcg/ml): mean zinc intake was less than 2/3rds the RDA. They conclude that glucose ingestion may alter serum zinc and should be considered in interpreting these levels.

Lopez, A.L.; Kohrs, M.B.; Horwitz, D.L.; Cyborski, C.K.; Czajka-Narins, D.M.; Kamath, S.

1986-03-05

402

Labile Serum Factor and Its Effect on Arbovirus Neutralization  

PubMed Central

Enhancement of neutralization of Sindbis, Venezuelan equine encephalitis, Eastern equine encephalitis, Western equine encephalitis, and St. Louis encephalitis viruses by labile serum factor (LSF) in human serum and plasma was demonstrated. Human serum and plasma could be diluted 1:8 and 1:16 and still retain some LSF activity. Satisfactory storage temperatures for retention of LSF activity were ?20 or ?56 C. Repeated freeze-thaw cycles of serum did not alter LSF activity, but the activity was completely eliminated by heating at 56 C for 5 min. LSF of human serum equally enhanced neutralization by Sindbis immune mouse and rabbit sera; these results suggest a lack of species specificity. Rehydrated lyophilized gunea pig complement did not restore LSF activity to heated human plasma. Serum components responsible for LSF activity were not dialyzable. Discovery of fresh serum without LSF activity established the need to pretest all sera used as LSF sources.

Chappell, W. A.; Sasso, D. R.; Toole, Roberta F.; Monath, Thomas P.

1971-01-01

403

Lipoproteins as substitutes for serum in Mycoplasma culture medium.  

PubMed Central

Crude lipoprotein-containing fractions obtained from sera of three different animal species were tested, in combination with bovine serum in Mycoplasma pneumoniae culture medium. All sera yielded at least one lipoprotein-containing component which was considerably more effective in promoting mycoplasma growth than the unfractionated serum sample from which it was derived. The very low activity of certain whole-serum samples tested in this investigation suggests that toxic substances may be present in whole serum which are not contained in the lipoprotein preparations. The greatest activity appeared in the high-density lipoprotein-containing components of bovine and horse sera and the low-density lipoprotein-containing components of human serum. The high degree of growth-supporting activity of these crude lipoprotein-containing serum components suggests that they may be useful as serum substitutes in mycoplasma culture media.

Washburn, L R; Somerson, N L

1979-01-01

404

Bromine levels in human serum, urine, hair  

Microsoft Academic Search

Much is known about the essentiality of the halogens fluorine (F), chlorine (Cl), and iodine (I), but very little has been\\u000a discussed with respect to bromine (Br). As a member of the halogen family its chemical properties are comparable to those\\u000a of other halogens, but its presence has been masked by the presence of I and Cl in chemical analyses.

R. E. Cuenca; W. J. Pories; J. Bray

1988-01-01

405

Make a Chemical Clock  

NSDL National Science Digital Library

This lesson for Grades 6-8 combines a short video with three experiments to observe and record chemical changes. The experiments use common household materials to demonstrate chemical reaction -- a change that leads to a transformation of one substance into another substance. In the 3rd experiment, there are two chemical reactions happening at the same time. Through careful observation, learners see that the 3rd reaction represents a "chemical clock", because the time it takes the chemicals to react happens very predictably, like a regular clock. Talking Science is part of National Public Radio's Science Friday initiative.

2011-08-18

406

Automated serum protein electrophoresis by Capillarys.  

PubMed

Capillary zone electrophoresis (CZE) of serum proteins is increasingly gaining impact in clinical laboratories. In this report, we evaluate automated capillary zone electrophoresis by Capillarys (Sebia, France). Within-run and between-run imprecision for the five electrophoretic fractions was <2% and <6%, respectively. Data obtained with Capillarys correlated with results obtained with agarose gel electrophoresis and Paragon CZE 2000 (Beckman Coulter, USA). Analysis of serum obtained from patients with inflammation, nephrotic syndrome, bisalbuminemia, and alpha1-antitrypsin deficiency revealed that Capillarys was able to detect these abnormalities. Two hundred thirty eight samples were analyzed by agarose gel electrophoresis, Capillarys, capillary electrophoresis using Paragon CZE 2000 system, and immunofixation. Sample selection was based on the presence of a disturbed morphology (e.g., spike) of the protein profile or hypogammaglobulinemia on agarose gel electrophoresis and/or Capillarys. Immunofixation revealed the presence of a monoclonal protein, oligoclonal bands, polyclonal pattern, and a normal profile in, respectively, 89, 66, 19, and 64 samples. With Capillarys, Paragon, and agarose gel electrophoresis, a spike and/or disturbed morphology of the profile was found in 222, 182, and 180 samples, respectively. In these samples, immunofixation was negative in 73 (33%), 46 (25%), and 39 (22%) samples, respectively. These data indicate that Capillarys has a lower specificity than agarose gel electrophoresis and Paragon 2000. Of the 89 samples with a monoclonal protein, Capillarys, Paragon, and agarose gel electrophoresis failed to detect, respectively, three, three, and one monoclonal protein(s). Interferences by radio-opaque agents, complement degradation products, fibrinogen, and triglycerides are described. In conclusion, automated capillary zone electrophoresis with Capillarys provides for reproducible, rapid, and reliable serum electrophoresis. PMID:12812271

Bossuyt, Xavier; Lissoir, Bénédicte; Mariën, Godelieve; Maisin, Diane; Vunckx, Jozef; Blanckaert, Norbert; Wallemacq, Pierre

2003-05-01

407

Serum selenium levels in Korean hepatoma patients.  

PubMed

The aim of this study was to determine serum selenium (Se) levels during the development of liver disease as well as the possible Se supplementation benefits in liver disease patients. Serum was collected from 187 patients with liver diseases and 120 normal healthy people living in Seoul. The samples were collected at the Kangnam St. Mary's Hospital College of Medicines, The Catholic University of Korea, in accordance with procedures approved by the Institutional Review Board of the Catholic University of Korea. Serum Se levels were quantified by inductively coupled plasma mass spectrometry and were compared between healthy and liver diseases patients. Se levels were 92.65?±?32.50 ?g/l in hepatitis infection, 92.33?±?30.66 ?g/l in hepatitis B virus infection and 96.41?±?51.50 ?g/l in hepatitis C virus infection, 96.42?±?32.80 ?g/l in cirrhosis, and 67.47?±?14.30 ?g/l in hepatoma patients. Findings were significantly lower in hepatitis and hepatoma as compared with the healthy participants (P?

Kim, In-Wook; Bae, Su-Mi; Kim, Yong-Wan; Liu, Hai-Bo; Bae, Si Hyun; Choi, Jong Young; Yoon, Seung Kew; Chaturvedi, Pankaj Kumar; Battogtokh, Gantumur; Ahn, Woong Shick

2012-02-12

408

Serum immunoglobulin levels in pediatric burn patients.  

PubMed

Infections remain the leading cause of death in burn patients. Immune responses play an important role in patient's defense mechanism against infection and decreasing morbidity and mortality associated with burn. Our goal was to determine serum immunoglobulin levels in pediatric burn patients in order to understand role of humoral immune defense in these patients. During this analytic cross sectional study from January 2011 to February 2012, all patients with burn and younger than 6 years old that were referred to Shahid Motahari burn and reconstruction center were enrolled. Patients had no inhalation injury or sepsis. Immunoglobulin levels were measured once on 3-5 days after burn. The burn size in 12 patients (24%) was less than 30%, in 30 patients (60%) were between 30% and 50% and in the remained 8 patients (16%) were more than 50%. In 45 patients (90%) depth and severity of burn were 2nd degree (superficial and deep) and in the remaining 5 patients (10%), it was 3rd or 4th degree. In 28 (56%), 1 (2%), 3 (6%), 35 (70%), 48 (96%), 19 (38%) and 6 (12%) patients IgG, IgM, IgA, IgG1, IgG2, IgG3 and IgG4 were lower than normal values, respectively. No significant correlation was seen between burn size (TBSA) and value of immunoglobulin (P>0.05). Although the drop in the serum concentration of immunoglobulins is irrespective to the burn size, more severe burn is associated with more decrease in the serum levels of IgA, IgM, IgG and its subclasses. However, further studies are needed to provide complementary data on this issue. PMID:23000373

Sobouti, Behnam; Fallah, Shahrzad; Ghavami, Yaser; Moradi, Masoud

2012-09-20

409

[Human serum albumin: isoforms and analbuminemia].  

PubMed

Persons with human serum albumin and a genetic variant are relatively common, whereas variant homozygotes are rare. About 65 structurally different variants are known. There is no clear relationship between bisalbuminemia and disease, and therefore isoforms are detected either because of a very pronounced increase in ligand binding or because of a modified electrophoretic mobility. The latter albumins may have modified binding and/or immunological properties. Analbuminemia is a rare but relative benign, homozygote condition in which especially the lipid metabolism is affected. PMID:18489873

Kragh-Hansen, Ulrich

2008-05-01

410

Serum ?-Fetoprotein: Diagnostic Significance in Liver Disease  

PubMed Central

Raised serum ?-fetoprotein levels measured by radioimmunoassay were found in 19 out of 24 (79%) patients with primary liver cancer and in 32 out of 311 (10%) patients with other liver diseases. The rise was transient in cases of hepatitis and a transient rise was also seen after alcohol intake ceased in two patients with cirrhosis. ?-Fetoprotein levels exceeding 500 ng/ml were 30-50 times more common in primary liver cancer than in other liver diseases. A rise in level seems to reflect the extent of liver regeneration in liver diseases other than primary cancer.

Ruoslahti, Erkki; Salaspuro, Mikko; Pihko, Helena; Andersson, Leif; Seppala, Markku

1974-01-01

411

Serum elastase activity is elevated in migraine.  

PubMed

Migraine has been associated with diseases considered to be related to extracellular matrix disorders--in particular, cervical artery dissection. In this population-based study, we found a highly significant association between migraine and the activity of serum elastase, a metalloendopeptidase degrading specific elastin-type amino acid sequences. Such enzymes are involved in matrix degradation. This association was seen in both sexes and was stronger for migraine with aura. These findings could help in the understanding of why patients with migraine are at higher risk of stroke. Further study is needed to establish whether extracellular matrix abnormalities play a broader role in the pathophysiology of migraine. PMID:10805337

Tzourio, C; El Amrani, M; Robert, L; Alpérovitch, A

2000-05-01

412

Exploring the glycosylation of serum CA125.  

PubMed

Ovarian cancer is the most lethal gynaecologic cancer affecting women. The most widely used biomarker for ovarian cancer, CA125, lacks sensitivity and specificity. Here, we explored differences in glycosylation of CA125 between serum from patients with ovarian cancer and healthy controls. We found differences between CA125 N-glycans from patient sera compared to controls. These include increases in core-fucosylated bi-antennary monosialylated glycans, as well as decreases in mostly bisecting bi-antennary and non-fucosylated glycans in patients compared to controls. Measurement of the glycosylated state of CA125 may therefore provide a more specific biomarker for patients with ovarian cancer. PMID:23896595

Saldova, Radka; Struwe, Weston B; Wynne, Kieran; Elia, Giuliano; Duffy, Michael J; Rudd, Pauline M

2013-07-26

413

Exploring the Glycosylation of Serum CA125  

PubMed Central

Ovarian cancer is the most lethal gynaecologic cancer affecting women. The most widely used biomarker for ovarian cancer, CA125, lacks sensitivity and specificity. Here, we explored differences in glycosylation of CA125 between serum from patients with ovarian cancer and healthy controls. We found differences between CA125 N-glycans from patient sera compared to controls. These include increases in core-fucosylated bi-antennary monosialylated glycans, as well as decreases in mostly bisecting bi-antennary and non-fucosylated glycans in patients compared to controls. Measurement of the glycosylated state of CA125 may therefore provide a more specific biomarker for patients with ovarian cancer.

Saldova, Radka; Struwe, Weston B.; Wynne, Kieran; Elia, Giuliano; Duffy, Michael J.; Rudd, Pauline M.

2013-01-01

414

[Determination of light chains in serum].  

PubMed

Free light chains of the immunoglobulin are identical to the Bence Jones protein. In 2001, a commercially available assay for the measurement of free light chains in serum (sFLC) became available (FreeLite Free Kappa & Free Lambda assay). Evidence from the use of the sFLC analysis is rapidly building, and the analysis is a potentially powerful supplement to the diagnostic tools already used in the diagnosis and monitoring of patients with monoclonal plasma cell disorders. However, there are several unsolved aspects for the use of this analysis which must be considered before sFLC can be used optimally in a daily clinical setting. PMID:20727297

Hansen, Charlotte Toftmann; Nielsen, Lars; Münster, Anna-Marie; Abildgaard, Niels

2010-08-23

415

SERUM BIOMARKERS FOR DETECTING ECTOPIC PREGNANCY  

PubMed Central

Unless an ectopic pregnancy is visible by ultrasound, diagnosis can be a challenge. Differentiating ectopic pregnancies from intrauterine pregnancies can be impossible without intervention or follow-up. This poses a clinical dilemma to the practitioner given the inherent danger to the mother of tubal rupture of an ectopic pregnancy versus the fear of intervening in the case of a desired pregnancy without certainty of diagnosis. Early diagnostic modalities are clearly lacking, and serum biomarkers are currently being investigated as a solution to need for a rapid and accurate test for ectopic pregnancy.

Rausch, Mary E; Barnhart, Kurt

2012-01-01

416

Immunogenicity of acrylate chemicals as assessed by antibody induction.  

PubMed

The immunogenicities of two acrylate chemicals, trimethylolpropane triacrylate (TMPTA) and methyl acrylate (MeAc), and one related vinyl compound, 4-vinyl pyridine (4VP), were investigated by determining the in vivo induction of IgG antibodies in guinea pigs. The injection of the chemicals emulsified in Freund's complete adjuvant resulted in the induction of serum antibody responses against MeAc and 4VP but not TMPTA. However, antibody with anti-TMPTA activity was produced following immunization of guinea pigs with TMPTA conjugated to protein, which allowed comparisons to be made of the immunogenic structural features of the compounds. PMID:3596820

Bull, J E; Henderson, D C; Turk, J L

1987-01-01

417

Synthesis and conjugation of ZnO nanoparticles with bovine serum albumin for biological applications  

NASA Astrophysics Data System (ADS)

Semiconductor nanomaterials tagged with biomarkers may be used for an early fluorescence-based detection of breast cancer. ZnO nanoparticles are water-soluble, non-toxic, photo-chemically stable with highly fluorescence applicability and are regarded for their possible biocompatibility. As a long-term research planning, we are aiming to use QDs conjugated with serum-biomarker for the diagnosis of breast cancer. The present work is a part in the said direction and reports preliminary observations on the synthesis and conjugation of ZnO nanoparticles with a representative protein marker.

Kumar, Pawan; Kumar, Parveen; Deep, Akash; Bharadwaj, Lalit M.

2013-04-01

418

Study of interaction of ZnO nanoparticles with human serum albumin using fluorescence spectroscopy  

NASA Astrophysics Data System (ADS)

Zinc oxide nanoparticles (ZnO NPs ~7.5 nm) were synthesized by chemical reduction method to study its interaction with Human Serum Albumin (HSA), the fluorescent protein, at room temperature. To investigate the interaction between ZnO NPs and HSA, the fluorescence quenching is measured for different concentrations of ZnO NPs. The quenching of fluorescence of fluorophore in HSA occurs by formation of HSA-ZnO complex in the solution as confirmed by Resonance light scattering spectra (RLS).

Bhogale, A.; Patel, N.; Mariam, J.; Dongre, P. M.; Miotello, A.; Kothari, D. C.

2013-02-01

419

Interaction of curcumin with human serum albumin: Thermodynamic properties, fluorescence energy transfer and denaturation effects  

NASA Astrophysics Data System (ADS)

Binding of curcumin, an antioxidant and anti-tumor agent to human serum albumin (HSA) has been investigated by following absorption and fluorescence spectral changes in HSA and curcumin. From the temperature dependent fluorescence changes and kinetic measurements using stopped-flow spectrometer, enthalpy and entropy changes and activation energy for the binding of curcumin to HSA were evaluated. Following fluorescence resonance energy transfer (FRET) between excited tryptophan in HSA and HSA bound curcumin, the critical transfer distance and mean distance between tryptophan-214 in HSA and curcumin were estimated. Effect of chemical and thermal denaturation of HSA on curcumin fluorescence was also studied.

Barik, Atanu; Mishra, Beena; Kunwar, Amit; Indira Priyadarsini, K.

2007-02-01

420

Protein and Chemical Microarrays--Powerful Tools for Proteomics  

PubMed Central

In the last few years, protein and chemical microarrays have emerged as two important tools in the field of proteomics. Specific proteins, antibodies, small molecule compounds, peptides, and carbohydrates can now be immobilized on solid surfaces to form high-density microarrays. Depending on their chemical nature, immobilization of these molecules on solid support is accomplished by in situ synthesis, nonspecific adsorption, specific binding, nonspecific chemical ligation, or chemoselective ligation. These arrays of molecules can then be probed with complex analytes such as serum, total cell extracts, and whole blood. Interactions between the analytes and the immobilized array of molecules are evaluated with a number of different detection systems. In this paper, various components, methods, and applications of the protein and chemical microarray systems are reviewed.

2003-01-01

421

Effect of the daily ingestion of a purified anthocyanin extract from grape skin on rat serum antioxidant capacity.  

PubMed

The aim of this work was to study the effect of the daily ingestion of a purified anthocyanin extract from red grape skin on rat serum antioxidant capacity (ORAC) and its safety for the intestinal epithelium. The study was carried out in rats orally administered with the extract for 10 days in either normal physiological conditions or exposed to a pro-oxidant chemical (CCl(4)). The oral administration of the extract significantly (P<0.05) enhanced the ORAC value of the deproteinised serum of about 50 % after 10 days of ingestion. Anthocyanin administration was also able to reverse completely the decrease in the serum ORAC activity induced by the CCl(4) treatment. Experiments with Ussing chamber mounted intestine allowed to exclude any toxicity of the extract for the intestinal epithelium. In conclusion, our results demonstrate that the purified anthocyanin extract from red grape skin enhances the total antioxidant capacity of the serum in either normal physiological condition or during oxidative stress induction, revealing a protective role against the decrease in the serum antioxidant capacity induced by a pro-oxidant compound. PMID:21574762

Lionetto, M G; Giordano, M E; Calisi, A; Erroi, E; De Nuccio, F; Schettino, T

2011-05-16

422

Efficacy of Chromium(III) Supplementation on Growth, Body Composition, Serum Parameters, and Tissue Chromium in Rats  

Microsoft Academic Search

Chromium(III) is often claimed to have a positive effect on body composition, while the responses in researches with supplementation\\u000a of different chemical form of chromium are various and inconsistent. We have studied the effects of 6 weeks of treatment with\\u000a three different forms of chromium (300 ?g\\/kg) as chromium chloride, chromium tripicolinate, and chromium nanocomposite (CrNano)\\u000a on growth, body composition, serum parameters,

L. Y. Zha; M. Q. Wang; Z. R. Xu; L. Y. Gu

2007-01-01

423

Tetrakis(4-sulfonatophenyl)porphyrin fluorescence as reporter of human serum albumin structural changes induced by guanidine hydrochloride  

Microsoft Academic Search

The interaction of the drug carrier protein human serum albumin (HSA) with the ionic, free base porphyrin tetrakis(4-sulfonatophenyl)porphyrin (TSPP) was investigated under chemical denaturation conditions using guanidine hydrochloride (Gdn-HCl) in aqueous solution at pH 7 and 2.5. Protein stability was studied by fluorescence spectroscopy using intrinsic tryptophan fluorescence, whereas far-UV circular dichroism gave information regarding conformational changes. Steady-state and time-resolved

Suzana M. Andrade; Sílvia M. B. Costa

2011-01-01

424

Metabolic syndrome: soybean foods and serum lipids.  

PubMed Central

Metabolic syndrome is a cluster of coronary heart disease (CHD) risk factors of which central obesity, insulin resistance, increased triglycerides/decreased HDL cholesterol, and hypertension are major cardiovascular risk factors. The educational objectives of this review are to describe hypocholesteromic effects from soybean foods. Early Italian observations indicated that isolated soy protein lowered total cholesterol, especially the LDL component, in humans with elevated serum lipids. Whole soybeans, with their major phytoestrogen inflavones (genistein, daidzein, and glycetin) intact, are known to decrease both total and LDL cholesterol. Major early reviews, meta-analyses, and clinical trials in hyperlipidemic humans indicate a predictable range of decreases in serum lipids: total cholesterol (10-19%), LDL cholesterol (14-20%), and triglycerides (8-14%). Recent, large, randomized trials in postmenopausal women indicated that a soy protein component induces significant increases in HDL cholesterol. Therapy for metabolic syndrome must first be patient education, especially for predominant U.S. minority groups (Afro-, Latino-, and Native Americans). The four major preventive health educational facts necessary to reduce CHD/metabolic syndrome must now recognize that whole soybeans are abundant sources of: 1) vegetable protein, 2) high soluble fiber content, 3) virtual absence of saturated fat, though high in polyunsaturated fats, and 4) major phytoestrogens.

Merritt, John C.

2004-01-01

425

Serum metabolic profile in multiple sclerosis patients.  

PubMed

Multiple sclerosis (MS) is a progressive demyelinating process considered as an autoimmune disease, although the causes of this pathology have not been yet fully established. Similarly to other neurodegenerations, MS is characterized by a series of biochemical changes affecting to different extent neuronal functions; great attention has been given to oxidative/nitrosative stress and to alterations in mitochondrial functions. According to previous data, MS patients show significant changes in the circulating concentrations of different metabolites, although it is still unclear whether uric acid undergoes to decrease, increase, or no change under this pathological condition. In this study, we report the serum metabolic profile in terms of purines, pyrimidines, creatinine, malondialdehyde, ascorbic acid, nitrite, and nitrate in a group of 170?MS patients. The results show increase in circulating uric acid and other oxypurines (hypoxanthine and xanthine), as well as in uridine and ?-pseudouridine. The concomitant increase in circulating creatinine, malondialdehyde, nitrite, and nitrate, and decrease in ascorbic acid, demonstrates that MS induces alteration in energy metabolism and in oxidants/antioxidants balance that can be monitored in serum of MS patients. PMID:22096628

Tavazzi, Barbara; Batocchi, Anna Paola; Amorini, Angela Maria; Nociti, Viviana; D'Urso, Serafina; Longo, Salvatore; Gullotta, Stefano; Picardi, Marika; Lazzarino, Giuseppe

2011-06-28

426

Serum Metabolic Profile in Multiple Sclerosis Patients  

PubMed Central

Multiple sclerosis (MS) is a progressive demyelinating process considered as an autoimmune disease, although the causes of this pathology have not been yet fully established. Similarly to other neurodegenerations, MS is characterized by a series of biochemical changes affecting to different extent neuronal functions; great attention has been given to oxidative/nitrosative stress and to alterations in mitochondrial functions. According to previous data, MS patients show significant changes in the circulating concentrations of different metabolites, although it is still unclear whether uric acid undergoes to decrease, increase, or no change under this pathological condition. In this study, we report the serum metabolic profile in terms of purines, pyrimidines, creatinine, malondialdehyde, ascorbic acid, nitrite, and nitrate in a group of 170?MS patients. The results show increase in circulating uric acid and other oxypurines (hypoxanthine and xanthine), as well as in uridine and ?-pseudouridine. The concomitant increase in circulating creatinine, malondialdehyde, nitrite, and nitrate, and decrease in ascorbic acid, demonstrates that MS induces alteration in energy metabolism and in oxidants/antioxidants balance that can be monitored in serum of MS patients.

Tavazzi, Barbara; Batocchi, Anna Paola; Amorini, Angela Maria; Nociti, Viviana; D'Urso, Serafina; Longo, Salvatore; Gullotta, Stefano; Picardi, Marika; Lazzarino, Giuseppe

2011-01-01

427

Serum Lycopene, Other Serum Carotenoids, and Risk of Prostate Cancer in US Blacks and Whites  

Microsoft Academic Search

Epidemiologic studies investigating the relation between individual carotenoids and risk of prostate cancer have produced inconsistent results. To further explore these associations and to search for reasons prostate cancer incidence is over 50% higher in US Blacks than Whites, the authors analyzed the serum levels of individual carotenoids in 209 cases and 228 controls in a US multicenter, population-based case-control

T. M. Vogt; S. T. Mayne; B. I. Graubard; C. A. Swanson; A. L. Sowell; J. B. Schoenberg; G. M. Swanson; R. S. Greenberg; R. N. Hoover; R. B. Hayes; R. G. Ziegler

2002-01-01

428

Red edge excitation shift emission spectroscopic investigation of serum albumins and serum albumin-bilirubin complexes  

Microsoft Academic Search

The microenvironments around the intrinsic and extrinsic fluorophores in bovine and human serum albumins as well as their complexes with bilirubin have been visualized by red edge excitation shift (REES) emmission spectroscopic investigation. The two albumins and their bilirubin complexes in aqueous buffered solutions (pH 7.5) do not exhibit any appreciable shift in their emission maxima, upon gradual change in

Samir K. Patra; Medini Kanta Pal

1997-01-01

429

Simultaneous automated measurement of serum total CK and CK-MM isoform ratio in serum.  

PubMed

We automated a two-step kinetic procedure for determining serum CK-MM isoform ratio using an immunoinhibition method. By measuring the total CK activity and the residual CK activity (serum CK-MM isoform) remaining after the inhibition by tissue CK-MM isoform specific monoclonal antibody reagent (CK-M01) the CKMM isoform ratio is calculated using the difference between total CK and residual CK activities divided by the residual CK activity. Linearities of total CK and residual CK assays were < or = 7750 U/L and 2,500 U/L, respectively; within-run CVs of isoform ratio (N = 10) were 2.8 and 7.0% (mean 0.14 and 0.60), respectively. The MM3/MM1 isoform ratio obtained with the proposed method (X) correlated well with the results of electrophoretic method (Y) according to the equation: Y = 0.98X-0.3, r = 0.988. The normal reference range of isoform ratios obtained by assaying 1,222 serum samples from healthy subjects was 0.09-0.75. The isoform ratio increased after onset of chest pain, peaking at 2-6 hr thereafter. A mean isoform ratio of 1.86 was obtained with serum sample from 86 patients diagnosed as having an acute myocardial infarction (AMI). This method is accurate and highly sensitive, as the detection and early diagnosis of AMI can be completed in 10 min. PMID:7807281

Uji, Y; Karmen, A; Sugiuchi, H; Okabe, H; Hata, K; Miura, M

1994-01-01

430

Human serum albumin enhances DNA transfection by lipoplexes and confers resistance to inhibition by serum  

Microsoft Academic Search

Cationic liposome–DNA complexes (‘lipoplexes’) are used as gene delivery vehicles and may overcome some of the limitations of viral vectors for gene therapy applications. The interaction of highly positively charged lipoplexes with biological macromolecules in blood and tissues is one of the drawbacks of this system. We examined whether coating cationic liposomes with human serum albumin (HSA) could generate complexes

Sérgio Simões; Vladimir Slepushkin; Pedro Pires; Rogério Gaspar; Maria C. Pedroso de Lima; Nejat Düzgüne?

2000-01-01

431

Serum protein binding of diazepam in maternal and foetal serum during pregnancy.  

PubMed Central

1 The serum binding capacity for diazepam was significantly lower in pregnancy and there was a linear correlation with gestational age. 2 The binding of diazepam was not correlated to albumin during pregnancy. 3 In cord sera there was a significantly reduced binding capacity for diazepam with albumin levels of less than 40 g/l.

Lee, J N; Chen, S S; Richens, A; Menabawey, M; Chard, T

1982-01-01

432

Value of measuring serum angiotensin I converting enzyme and serum lysozyme in the management of sarcoidosis  

Microsoft Academic Search

Serum angiotensin I converting enzyme (ACE) and lysozyme have been measured in 23 controls, 115 patients with sarcoidosis, and 64 with other chest diseases. Both enzymes were significantly raised in sarcoidosis. ACE was raised above the normal range in 21 of 72 (29%) patients with definite sarcoidosis and in 17 of 38 (45%) of those who were untreated and seen

C W Turton; E Grundy; G Firth; D Mitchell; B G Rigden; M Turner-Warwick

1979-01-01

433

Toxic Chemical System (TCS)  

SciTech Connect

The Toxic Chemical System (TCS) will have the capacity to process chemical data, calculate chemical formulas, and format the data into the United States (US) Environmental Protection Agency (EPA) Toxic Chemical Release Inventory Reporting Form R of Section 313 of the Emergency Planning and Community Right-to-Know Act (EPCRA), hereafter be referred to as ``Form R.`` The filing of this form is required of all industries which manufacture, process or otherwise use any EPA listed chemicals in quantities in excess of their threshold planning quantities (TPQ). Facilities required to file the Form R must report the quantities of both routine and accidental releases of listed toxic chemicals on-site during the calendar year and the amount contained in waste products transferred off-site. This paper describes a specialized computer system designed for regulatory compliance.

Del Gandio, P.

1994-09-01

434

Miniature chemical measurement systems  

SciTech Connect

Prospect of microfabricated monolithic devices that accomplish complete chemical assays is enticing. Early work with microfabricated chemical analysis devices focused on separations methods. More recently reagent manipulation has been integrated with separation devices to create more powerful capabilities. Examples of procedures, other than separations, that have been demonstrated on micromachined structures include reagent mixing, dilution, and reaction, preconcentration through sample stacking and biopolymer tagging for detection. Developments in liquid phase microfabricated chemical analysis devices are reviewed.

Ramsey, J.M.

1996-12-31

435

Chemical warfare agents  

Microsoft Academic Search

\\u000a Chemical warfare agents are compounds of different chemical structures. Simple molecules such as chlorine as well as complex\\u000a structures such as ricin belong to this group. Nerve agents, vesicants, incapacitating agents, blood agents, lung-damaging\\u000a agents, riot-control agents and several toxins are among chemical warfare agents. Although the use of these compounds is strictly\\u000a prohibited, the possible misuse by terrorist groups

Kamil Ku?a; Miroslav Pohanka

436

The binding of flavopiridol to blood serum albumin.  

PubMed

Flavopiridol is a potent cyclin-dependant kinase (CDK) inhibitor and is in clinical trials for anticancer treatment. A limiting factor in its drug development has been the high dosage required in human clinical trials. The high dosage is suggested to be necessary because of significant flavopiridol binding to human blood serum. Albumin is the major protein component of blood serum and has been suggested as a likely high affinity binding target. We characterized the binding of human serum albumin to flavopiridol using circular dichroism (hereafter CD). Flavopiridol bound to human serum albumin has a diagnostic CD binding peak at 284 nm. The diagnostic CD binding peak was unobservable for flavopiridol with bovine serum albumin, using the same experimental conditions. However, under higher albumin concentrations a small CD signal is observed confirming, flavopiridol binds to bovine serum albumin as well. PMID:21038395

Myatt, Daniel; Johnson, Louise; Baumli, Sonja; Siligardi, Giuliano

2010-01-01

437

Detection of natural and induced phenoloxidase activities in human serum.  

PubMed

Natural and induced phenoloxidase activities were detected in human serum using nine different phenolic substrates, namely, tyrosine, tyramine, L-DOPA, DL-DOPA, dopamine, catechol, hydroquinone, protocatechuic acid and pyrogallol. Phenoloxidase activity was induced anew in serum using exogenous elicitors, such as proteases or detergents. Among the proteases and detergents tested, pronase, SDS and Tween 20 were the best elicitors of phenoloxidase activities in serum, wherein, hydroquinone was the best phenolic substrate for both untreated as well as pronase treated serum and SDS or Tween 20 treated serum resulted in highest oxidation of dopamine or tyrosine, respectively. In the present study, all these oxidative reactions were inhibited by phenoloxidase inhibitors, namely, PTU and tropolone, thereby, confirming the role of phenoloxidase in human serum. PMID:22863449

Manikandan, Beulaja; Ramar, Manikandan

2012-07-31

438

Effect of tetracycline administration on serum amylase activity in calves.  

PubMed

Tetracycline and related compounds are used extensively as broad spectrum antibiotics in the treatment of bacterial infections in ruminants. Tetracycline may cause acute pancreatitis which may result in increased serum amylase activity. However, it has been shown that administration of oxytetracycline in human results in decrease serum amylase activity. In this study changes in serum amylase activity were measured in 20 clinically healthy calves following intravenous injection of oxytetracycline hydrochloride at 10 mg/kg of body weight. Blood samples were collected at 30, 60, and 120 minutes after oxytetracycline injection. Serum amylase activity was measured using the amyloclastic assay. The activity of serum amylase was increased significantly (P?serum amylase activity in calves. PMID:23961401

Zendehbad, Bamdad; Alipour, Adeleh; Zendehbad, Hussein

2013-07-20

439

Physical and Chemical Changes  

NSDL National Science Digital Library

Physical and chemical changes in matter affect us every day. Use the following resources to help you understand these changes more completely. Read this document to help you understand the difference between physical and chemical changes in matter. definitions Watch this! It illustrates the physical change of matter. physical change video Now, watch this! It illustrates the chemical change of matter. chemical change video Click on this link to read and explore the Utah Science Sci-ber Site. It will help you to ...

Holly, Mrs.

2010-11-15

440

310 Facility chemical specifications  

SciTech Connect

The 300 area Treated Effluent Disposal Facility (TEDF) was designed and built to treat the waste water from the 300 area process sewer system. Several treatment technologies are employed to remove the trace quantities of contaminants in the stream, including iron coprecipitation, clarification, filtration, ion exchange, and ultra violet light/hydrogen peroxide oxidation of organics. The chemicals that will be utilized in the treatment process are hydrogen peroxide, sulfuric acid, sodium hydroxide, and ferric chloride. This document annotates the required chemical characteristics of TEDF bulk chemicals as well as the criteria that were used to establish these criteria. The chemical specifications in appendix B are generated from this information.

Hagerty, K.J.

1997-05-21