| 1. |
- Jakobsson, Kristina, et al.
(författare)
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Polybrominated diphenyl ethers in maternal serum, umbilical cord serum, colostrum and mature breast milk : Insights from a pilot study and the literature
- 2012
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Ingår i: Environment International. - : Elsevier BV. - 0160-4120 .- 1873-6750. ; 47, s. 121-130
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Tidskriftsartikel (refereegranskat)abstract
- Human serum and mother's milk are frequently used to assess exposure to polybrominated diphenyl ethers (PBDEs), including transplacental transfer to the foetus. However, little is known about the kinetics of PBDEs, especially the highly brominated BDE congeners.In this pilot study, maternal serum samples were collected from 10 women at delivery and five to six weeks post partum. Umbilical serum was also obtained. Milk was donated two to five days, and five to six weeks after delivery. The amount of PBDEs in these samples was determined using liquid–liquid extraction and GC/MS.Low, moderately and highly brominated diphenyl ethers were present in umbilical cord serum, indicating placental transfer. The lipid-adjusted levels of BDE-47, BDE-207 and BDE-209 were similar in maternal and umbilical cord serum, whereas the cord serum levels for the penta- to octa-BDEs quantified were lower than in maternal serum.Marked changes were seen in the congener pattern in breast milk during the first month of lactation, whereas maternal serum levels did not change significantly. The general pattern was an enrichment of low to moderately brominated congeners (i.e. from BDE-17 to BDE-154, with the exception of BDE-28) in colostrum compared with maternal serum. In contrast, more highly brominated congeners were found at similar, or lower levels in colostrum than in maternal serum. After the transition from colostrum to mature milk, the levels of BDE-153 and BDE-209 were substantially reduced, and BDE‐209 was below the limit of detection in 6 out of 9 samples.A literature review on the design and reporting of studies on the transfer of PBDEs from mother to infant revealed a lack of transparency in many cases. The use of the recently published STROBE-ME guidelines is therefore recommended.
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| 2. |
- Cotgreave, Ian, et al.
(författare)
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Pyriproxifen and microcephaly: an investigation of potential ties to the ongoing "Zika epidemic"
- 2016
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- As part of the Swetox mission to react to emerging concerns in chemical health and environmental safety, a preliminary litterature investigation was undertaken to gather all readily available scientific information on PPF with respect to safety assessment, in order to better understand potential links between chemical exposure and the devopment of microcephaly in affected areas. Therefore the contents of the report do not constitute an attempt at either questioning the use of existing regulatory data in the manner prescribed by international regulatory proceedures, or as a new risk assessment, based on the scientific information and concepts discussed. Here we report our findings, with particular emphasis on exisiting regulatory information, potential for lack of translation of results from regulatory animal testing to humans, lack of human exposure data and suggestions on plausible mode(s) of action of PPF in human neurodevelopmental adversities such as microcephaly.
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| 3. |
- Repouskou, Anastasia, et al.
(författare)
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Long term transcriptional and behavioral effects in mice developmentally exposed to a mixture of endocrine disruptors associated with delayed human neurodevelopment
- 2020
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 10, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- Accumulating evidence suggests that gestational exposure to endocrine disrupting chemicals (EDCs) may interfere with normal brain development and predispose for later dysfunctions. The current study focuses on the exposure impact of mixtures of EDCs that better mimics the real-life situation. We herein describe a mixture of phthalates, pesticides and bisphenol A (mixture N1) detected in pregnant women of the SELMA cohort and associated with language delay in their children. To study the long-term impact of developmental exposure to N1 on brain physiology and behavior we administered this mixture to mice throughout gestation at doses 0x, 0.5x, 10x, 100x and 500x the geometric mean of SELMA mothers' concentrations, and examined their offspring in adulthood. Mixture N1 exposure increased active coping during swimming stress in both sexes, increased locomotion and reduced social interaction in male progeny. The expression of corticosterone receptors, their regulator Fkbp5, corticotropin releasing hormone and its receptor, oxytocin and its receptor, estrogen receptor beta, serotonin receptors (Htr1a, Htr2a) and glutamate receptor subunit Grin2b, were modified in the limbic system of adult animals, in a region-specific, sexually-dimorphic and experience-dependent manner. Principal component analysis revealed gene clusters associated with the observed behavioral responses, mostly related to the stress axis. This integration of epidemiology-based data with an experimental model increases the evidence that prenatal exposure to EDC mixtures impacts later life brain functions.
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| 4. |
- Bergman, Åke, et al.
(författare)
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Manufacturing doubt about endocrine disrupter science : A rebuttal of industry-sponsored critical comments on the UNEP/WHO report "State of the Science of Endocrine Disrupting Chemicals 2012"
- 2015
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Ingår i: Regulatory toxicology and pharmacology. - : Academic Press. - 0273-2300 .- 1096-0295. ; 73:3, s. 1007-1017
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Tidskriftsartikel (refereegranskat)abstract
- We present a detailed response to the critique of "State of the Science of Endocrine Disrupting Chemicals 2012" (UNEP/WHO, 2013) by financial stakeholders, authored by Lamb et al. (2014). Lamb et al.'s claim that UNEP/WHO (2013) does not provide a balanced perspective on endocrine disruption is based on incomplete and misleading quoting of the report through omission of qualifying statements and inaccurate description of study objectives, results and conclusions. Lamb et al. define extremely narrow standards for synthesizing evidence which are then used to dismiss the UNEP/WHO 2013 report as flawed. We show that Lamb et al. misuse conceptual frameworks for assessing causality, especially the Bradford-Hill criteria, by ignoring the fundamental problems that exist with inferring causality from empirical observations. We conclude that Lamb et al.'s attempt of deconstructing the UNEP/WHO (2013) report is not particularly erudite and that their critique is not intended to be convincing to the scientific community, but to confuse the scientific data. Consequently, it promotes misinterpretation of the UNEP/WHO (2013) report by non-specialists, bureaucrats, politicians and other decision makers not intimately familiar with the topic of endocrine disruption and therefore susceptible to false generalizations of bias and subjectivity.
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| 5. |
- Bergman, Åke, et al.
(författare)
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Science and policy on endocrine disrupters must not be mixed : a reply to a "common sense" intervention by toxicology journal editors
- 2013
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Ingår i: Environmental Health. - : BioMed Central (BMC). - 1476-069X. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- The "common sense" intervention by toxicology journal editors regarding proposed European Union endocrine disrupter regulations ignores scientific evidence and well-established principles of chemical risk assessment. In this commentary, endocrine disrupter experts express their concerns about a recently published, and is in our considered opinion inaccurate and factually incorrect, editorial that has appeared in several journals in toxicology. Some of the shortcomings of the editorial are discussed in detail. We call for a better founded scientific debate which may help to overcome a polarisation of views detrimental to reaching a consensus about scientific foundations for endocrine disrupter regulation in the EU.
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| 6. |
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| 7. |
- Ulhaq, Mazhar, et al.
(författare)
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Tissue uptake, distribution and elimination of C-14-PFOA in zebrafish (Danio rerio)
- 2015
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Ingår i: Aquatic Toxicology. - : Elsevier BV. - 0166-445X .- 1879-1514. ; 163, s. 148-157
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Tidskriftsartikel (refereegranskat)abstract
- Perfluorooctanoic acid (PFOA) is a long-chain perfluorinated chemical that has been shown to be non-degradable and persistent in the environment. Laboratory studies on bioconcentration and compound-specific tissue distribution in fish can be valuable for prediction of the persistence and environmental effects of the chemicals. In the present study male and female zebrafish (Danio redo) were continuously exposed to 10 mu g/L of radiolabeled perfluorooctanoic acid (C-14-PFOA) for 40 days, after which the exposed fish were transferred to fresh clean water for another 80 days wash-out period. At defined periodic intervals during the uptake and wash-out, fish were sampled for liquid scintillation counting and whole body autoradiography to profile the bioconcentration and tissue distribution of PFOA. The steady-state concentration of C-14-PFOA in the zebrafish was reached within 20-30 days of exposure. The concentration-time course of C-14-PFOA displayed a bi-exponential decline during washout, with a terminal half-life of approximately 13-14 days. At steady-state the bioconcentration of C-14-PFOA into whole-body fish was approximately 20-30 times greater than that of the exposure concentration, with no differences between females and males. The bioconcentration factors for liver and intestine were approximately 100-fold of the exposure medium, while in brain, ovary and gall bladder the accumulation factors were in the range 15-20. Whole-body autoradiograms confirmed the highest labeling of PFOA in bile and intestines, which implies enterohepatic circulation of PFOA. The C-14-PFOA was also observed in maturing vitellogenic oocytes, suggesting chemical accumulation via yolk proteins into oocytes with plausible risk for adverse effects on early embryonic development and offspring health. The bioconcentration at several C-14-PFOA exposure concentrations were also investigated (0.3-30 mu g/L). This showed that bioconcentration increased linearly with tank exposure in the present in vivo model under steady-state conditions. From this model tissue concentrations of PFOA can be predicted when the external exposure level is known. The present study has generated experimental data on PFOA kinetics in zebrafish that can be valuable for aquatic environmental risk assessment.
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| 8. |
- Al-Anati, Lauy, et al.
(författare)
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Hydroxyl metabolite of PCB 180 induces DNA damage signaling and enhances the DNA damaging effect of benzo[a]pyrene
- 2015
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Ingår i: Chemico-Biological Interactions. - : Elsevier. - 0009-2797 .- 1872-7786. ; 239, s. 164-173
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Tidskriftsartikel (refereegranskat)abstract
- Non-dioxin-like (NDL) polychlorinated biphenyls (PCBs) and their hydroxyl metabolites (OH-PCBs) are ubiquitous environmental contaminants in human tissues and blood. The toxicological impact of these metabolites is poorly understood. In this study rats were exposed to ultrapure PCB180 (10-1000 mg/kg bw) for 28 days and induction of genotoxic stress in liver was investigated. DNA damage signaling proteins (pChk1Ser317 and gamma H2AXSer319) were increased dose dependently in female rats. This increase was paralleled by increasing levels of the metabolite 3'-OH-PCB180. pChk1 was the most sensitive marker. In in vitro studies HepG2 cells were exposed to 1 mu M of PCB180 and 3'-OH-PCB180 or the positive control benzo[a]pyrene (BaP, 5 mu M). 3'-OH-PCB180, but not PCB180, induced CYP1A1 mRNA and gamma H2AX. CYP1A1 mRNA induction was seen at 1 h, and gamma H2AX at 3 h. The anti-oxidant N-Acetyl-L-Cysteine (NAC) completely prevented, and 17 beta-estradiol amplified the gamma H2AX induction by 3'-OH-PCB180. As 3'-OH-PCB180 induced CYP1A1, a major BaP-metabolizing and activating enzyme, interactions between 3'-OH-PCB180 and BaP was also studied. The metabolite amplified the DNA damage signaling response to BaP. In conclusion, metabolism of PCB180 to its hydroxyl metabolite and the subsequent induction of CYP1A1 seem important for DNA damage induced by PCB180 in vivo. Amplification of the response with estradiol may explain why DNA damage was only seen in female rats.
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| 9. |
- Bergman, Erika, et al.
(författare)
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Time trends in pediatric fractures in a Swedish city from 1950 to 2016
- 2020
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Ingår i: Acta Orthopaedica. - : Medical Journals Sweden AB. - 1745-3674 .- 1745-3682. ; 91:5, s. 598-604
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Tidskriftsartikel (refereegranskat)abstract
- Background and purpose — As previous studies indicate time trends in pediatric fracture incidence, we followed the incidence in a Swedish city between 1950 and 2016. Patients and methods — Malmö city, Sweden had 322,574 inhabitants in 2015. We used diagnosis registry, charts, and radiographs of the only city hospital to classify fractures in individuals < 16 years in 2014–2016, and compared these with data from 1950–2006. We used joinpoint regression to analyze time trends and present results as mean annual percentage changes (APC). Differences between periods are described as incident rate ratios (IRR). To describe uncertainty, 95% confidence intervals (CI) are used. Results — During 2014–2016 the pediatric fracture incidence was 1,786 per 105 person-years (boys 2,135 and girls 1,423). From 1950 onwards age-adjusted fracture incidence increased until 1979 in both boys (APC +1.5%, CI 1.2–1.8) and girls (APC +1.6%, CI 0.8–2.5). The incidence remained stable from 1979 to 2016 (APC in boys 0.0%, CI –0.3 to 0.3 and in girls –0.2%, CI –1.1 to 0.7). Age-adjusted incidence 2014–2016 was higher than 2005–2006 in girls (IRR 1.1, CI 1.03–1.3), but not in boys (IRR 1.0, CI 0.9–1.1). Interpretation — Fracture incidence was in girls higher in 2014–2016 than in 2005–2006. However, only with more than 2 measuring points are meaningful trend analyses possible. When we analyzed the period 1950–2016 with 17 measuring points and joinpoint regression, we found that fracture incidence increased in both sexes until 1979 but has thereafter been stable.
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| 10. |
- Björk, Christel, et al.
(författare)
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Persistent organic pollutants have dose and CAG repeat length dependent effects on androgen receptor activity in vitro
- 2011
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Ingår i: Reproductive Toxicology. - : Elsevier BV. - 0890-6238 .- 1873-1708. ; 32, s. 293-297
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Tidskriftsartikel (refereegranskat)abstract
- Recently, the effect of exposure to persistent organic pollutants (POPS) on sperm concentration was only seen in men with a short androgen receptor (AR) gene CAG repeat. In order to investigate whether these effects could be observed also in vitro, we tested the impact of 2,2’,4,4’,5,5’-hexachlorobiphenyl (CB-153) and 1,1-bis-(4-chlorophenyl)-2,2-dichloroethene (4,4’-DDE) on 5 alpha-dihydrotestosterone activated ARs containing 16,22 and 28 CAG repeats, respectively. Single exposure to 4,4’-DDE had the most pronounced effect on the AR activity containing 16 CAG repeats, whereas 28 CAG was the most sensitive variant when a mixture of the two compounds was added. Thus, our in vitro results have confirmed the in vivo data indicating a CAG repeat length dependent effect of endocrine disrupters on the AR activity.
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