| 1. |
- Qazi, Mousumi R, et al.
(author)
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High-dose, short-term exposure of mice to perfluorooctanesulfonate (PFOS) or perfluorooctanoate (PFOA) affects the number of circulating neutrophils differently, but enhances the inflammatory responses of macrophages to lipopolysaccharide (LPS) in a similar fashion.
- 2009
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In: Toxicology. - : Elsevier BV. - 1879-3185 .- 0300-483X. ; 262:3, s. 207-14
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Journal article (peer-reviewed)abstract
- Having found previously that high-dose, short-term dietary exposure of mice to perfluorooctanesulfonate (PFOS) or perfluorooctanoate (PFOA) suppresses adaptive immunity, in the present study we characterize the effects of these fluorochemicals on the innate immune system. Male C57BL/6 mice receiving 0.02% (w/w) PFOS or PFOA in their diet for 10 days exhibited a significant reduction in the numbers of total white blood cells (WBC), involving lymphopenia in both cases, but neutropenia only in response to treatment with PFOA. Moreover, both compounds also markedly reduced the number of macrophages (CD11b(+) cells) in the bone marrow, but not in the spleen or peritoneal cavity. The ex vivo production of tumor necrosis factor-alpha (TNF-alpha) and interleukin 6 (IL-6) by peritoneal macrophages isolated from animals treated with PFOA or PFOS was increased modestly. Moreover, both fluorochemicals markedly enhanced the ex vivo production of these same cytokines by peritoneal and bone marrow macrophages stimulated either in vitro or in vivo with lipopolysaccharide (LPS); whereas there was no such effect on splenic macrophages. The serum levels of these inflammatory cytokines observed in response to in vivo stimulation with LPS were elevated substantially by prior exposure to PFOA, but not by PFOS. None of these parameters of innate immunity were altered in animals receiving a dietary dose of these compounds that was 20-fold lower (0.001%, w/w). These findings reveal that in addition to suppressing adaptive immunity, high-dose, short-term exposure of mice to either PFOS or PFOA augments inflammatory responses to LPS, a potent activator of innate immunity.
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| 2. |
- Qazi, Mousumi Rahman, et al.
(author)
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The atrophy and changes in the cellular compositions of the thymus and spleen observed in mice subjected to short-term exposure to perfluorooctanesulfonate are high-dose phenomena mediated in part by peroxisome proliferator-activated receptor-alpha (PPARalpha).
- 2009
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In: Toxicology. - : Elsevier BV. - 1879-3185 .- 0300-483X. ; 260:1-3, s. 68-76
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Journal article (peer-reviewed)abstract
- We have previously shown that short-term, high-dose exposure of mice to the environmentally persistent perfluorooctanoate (PFOA) results in thymic and splenic atrophy and the attenuation of specific humoral immune responses. Here we characterize the effects of a 10-day treatment with different dietary doses (1-0.001%, w/w) of perfluorooctanesulfonate (PFOS), a similar fluorochemical, on the immune system of male C57BL/6 mice. At doses greater than 0.02%, PFOS induced clinical signs of toxicity in the animals, whereas at the concentration of 0.02%, this compound caused weight loss, hepatomegaly and atrophy of the thymus, spleen and adipose tissue without toxicity. With this latter dose, histopathological and flow-cytometric analysis revealed that (i) the thymic cortex was virtually depleted of cells; (ii) the total numbers of thymocytes and splenocytes were reduced by 84 and 43%, respectively; (iii) although all populations of thymocytes and splenocytes were smaller, the thymic CD4(+)CD8(+) cells and the splenic B-lymphocytes were most decreased. These alterations resembled those evoked by analogous exposure to PFOA, but were less pronounced. At lower doses (less than 0.02%), PFOS induced hepatomegaly without affecting the thymus or spleen. Finally, comparison of male wild-type 129/Sv mice and the corresponding knock-outs lacking peroxisome proliferator-activated receptor-alpha (PPARalpha) indicated that these effects of PFOS are not strain-dependent. More importantly, hepatomegaly is independent of PPARalpha, the thymic changes are partially dependent on this receptor, and splenic responses are largely eliminated in its absence. Thus, immunomodulation caused by PFOS is a high-dose phenomenon partially dependent on PPARalpha.
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| 3. |
- Shabalina, Irina G., et al.
(author)
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The Environmental Pollutants Perfluorooctane Sulfonate and Perfluorooctanoic Acid Upregulate Uncoupling Protein 1 (UCP1) in Brown-Fat Mitochondria Through a UCP1-Dependent Reduction in Food Intake
- 2015
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In: Toxicological Sciences. - : Oxford University Press (OUP). - 1096-6080 .- 1096-0929. ; 146:2, s. 334-343
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Journal article (peer-reviewed)abstract
- The environmental pollutants perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) cause a dramatic reduction in the size of the major adipose tissue depots and a general body weight decrease when they are added to the food of mice. We demonstrate here that this is mainly due to a reduction in food intake; this reduction was not due to food aversion. Remarkably and unexpectedly, a large part of the effect of PFOA/PFOS on food intake was dependent on the presence of the uncoupling protein 1 (UCP1) in the mice. Correspondingly, PFOA/PFOS treatment induced recruitment of brown adipose tissue mitochondria: increased oxidative capacity and increased UCP1-mediated oxygen consumption (thermogenesis). In mice pair-fed to the food intake during PFOA/PFOS treatment in wildtype mice, brown-fat mitochondrial recruitment was also induced. We conclude that we have uncovered the existence of a regulatory component of food intake that is dependent upon brown adipose tissue thermogenic activity. The possible environmental consequences of this novel PFOA/PFOS effect (a possible decreased fitness) are noted, as well as the perspectives of this finding on the general understanding of control of food intake control and its possible extension to combatting obesity.
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| 4. |
- Sundström, Maria, et al.
(author)
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A temporal trend study (1972-2008) of perfluorooctanesulfonate, perfluorohexanesulfonate, and perfluorooctanoate in pooled human milk samples from Stockholm, Sweden
- 2010
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In: Environment International. - : Elsevier BV. - 0160-4120 .- 1873-6750. ; 37:1, s. 178-83
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Journal article (peer-reviewed)abstract
- The widespread presence of perfluorooctanesulfonate (PFOS), perfluorooctanoate (PFOA), and perfluorohexanesulfonate (PFHxS) in human general populations and their slow elimination profiles have led to renewed interest in understanding the potential human neonatal exposures of perfluoroalkyls (PFAs) from consumption of human milk. The objective of this study was to evaluate the concentrations of PFOS, PFHxS, and PFOA in pooled human milk samples obtained in Sweden between 1972 and 2008 (a period representing the most significant period of PFA production) and to see whether the time trend of these analytes parallels that indicated in human serum. Chemical analysis of PFOS, PFHxS, and PFOA was performed on pooled Swedish human milk samples from 1972 to 2008 after methodological refinements. The 20 samples which formed the 2007 pool were also analyzed individually to evaluate sample variations. Analyses were performed by HPLC-MS/MS. Due to the complexities of the human milk matrix and the requirement to accurately quantitate low pg/mL concentrations, meticulous attention must be paid to background contamination if accurate results are to be obtained. PFOS was the predominant analyte present in the pools and all three analytes showed statistically significant increasing trends from 1972 to 2000, with concentrations reaching a plateau in the 1990s. PFOA and PFOS showed statistically significant decreasing trends during 2001-2008. At the end of the study, in 2008, the measured concentrations of PFOS, PFHxS, and PFOA in pooled human milk were 75 pg/mL, 14 pg/mL, and 74 pg/mL, respectively. The temporal concentration trends of PFOS, PFHxS, and PFOA observed in human milk are parallel to those reported in the general population serum concentrations.
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| 5. |
- Sundström, Maria, et al.
(author)
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Comparative pharmacokinetics of perfluorohexanesulfonate (PFHxS) in rats, mice, and monkeys
- 2012
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In: Reproductive Toxicology. - : Elsevier BV. - 0890-6238 .- 1873-1708. ; 33:4, s. 441-451
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Journal article (peer-reviewed)abstract
- Perfluorohexanesulfonate (PFHxS) has been found in biological samples from wildlife and humans. The human geometric mean serum PFHxS elimination half-life has been estimated to be 2665 days. A series of studies was undertaken to establish pharmacokinetic parameters for PFHxS in rats, mice, and monkeys after single administration with pharmacokinetic parameters determined by WinNonlin (R) software. Rats and mice appeared to be more effective at eliminating PFHxS than monkeys. With the exception of female rats, which had serum PFHxS elimination half-life of approximately 2 days, the serum elimination half-lives in the rodent species and monkeys approximated 1 month and 4 months, respectively, when followed over extended time periods (10-24 weeks). Collectively, these studies provide valuable insight for human health risk assessment regarding the potential for accumulation of PFHxS in humans.
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| 6. |
- Sundström, Maria, 1980-
(author)
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Radiosynthesis of Perfluoroalkyl Substances : Chemical analysis, uptake, distribution, and partitioning studies
- 2012
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Doctoral thesis (other academic/artistic)abstract
- Perfluoroalkyl substances (PFASs) are widely utilized manmade chemicals. Their properties have made them highly appreciated in a variety of industrial and consumer product applications, including fire-fighting foams, hydraulic fluids, as well as in cookware and food contact papers.However, some of the PFASs are highly persistent in the environment and their toxicological profiles are of concern. Voluntary and regulatory efforts have been taken to reduce the environmental levels of PFASs. These actions have resulted in a reduction of PFASs in human milk from Stockholm as presented in this thesis.The radiosyntheses of 35S-PFOS, 35S-PFBS, and 14C-PFOA presented herein were applied for distribution studies in mice but also for solubility and adhesion experiments of common laboratory solvents and buffers. The radiosynthesis employed reactive Grignard reagents, perfluoroalkyliodides, and 35S-sulfur dioxide or 14C-carbon dioxide. The distribution studies were performed with 35S-PFOS on both pregnant mice and their offspring as well as on male mice. The mice were subjected to whole-body autoradiography and the tissues were analyzed by liquid scintillation counting. Liver and lungs were the target organs for 35S-PFOS in the dams. The fetuses and pups had remarkable high levels of 35S-PFOS in their lungs as well as in the brain. The male mice were given a high dose and a more environmental relevant dose of 35S-PFOS. PFOS was transferred from the blood to the tissues as the dose increased.In another study the distribution pattern of the shorter homologue PFBS was compared to PFOS. 35S-PFBS was utilized and demonstrated a 5-40 fold lower tissue levels in comparison to PFOS.The pharmacokinetic parameters determined for PFHxS in mice, rats, and monkeys will provide valuable insight in establishing a proper risk assessment for this compound. The study confirms the common species differences in serum elimination half-life that are associated with PFASs.
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