| 1. |
- Andersson, B Erik, et al.
(författare)
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Incomplete degradation of polycyclic aromatic hydrocarbons in soil inoculated with wood-rotting fungi and their effect on the indigenous soil bacteria
- 2003
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Ingår i: Environmental Toxicology and Chemistry. ; 22:6, s. 1238-43
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Tidskriftsartikel (refereegranskat)abstract
- Soil artificially contaminated with fluorene, phenanthrene, pyrene, and benz[a]anthracene was inoculated with the wood-rotting fungi Pleurotus ostreatus and Antrodia vaillantii. During 12 weeks of incubation, polycyclic aromatic hydrocarbon (PAH) degradation and the formation of persistent degradation products were monitored by chemical analysis. In addition, the effect on the indigenous soil bacteria was studied by plate count techniques and by measuring the concentration of bacteria-specific phospholipid fatty acids (PLFAs). In both soils inoculated with fungi, the PAH degradation was enhanced compared to the control soil without fungi. The white-rot fungus P. ostreatus accelerated the degradation rate radically the first weeks, while the effect of the brown-rot fungus was more pronounced at later stages during the 12-week study. In a soil with no amendments, the final degradation result was similar to that in the soil with added fungi, although the degradation pattern for the individual PAHs was different. Furthermore, the degradation by P. ostreatus was accompanied by an accumulation of PAH metabolites, that is, 9-fluorenone, benz[a]anthracene-7,12-dione, and two compounds identified as 4-hydroxy-9-fluorenone and 4-oxapyrene-5-one, that was not seen in the other soils. The inoculation with the white-rot fungus also had a large negative effect on the indigenous soil bacteria. This could be an important drawback of using the white-rot fungus P. ostreatus in soil bioremediation since a sequential fungal–bacterial degradation probably is needed for a complete degradation of PAHs in soil. In the soil inoculated with A. vaillantii, on the other hand, no metabolites accumulated, and no negative effects were observed on the indigenous microorganisms.
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| 2. |
- Blumenau, AT, et al.
(författare)
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Dislocation structures in diamond : density-functional based modelling and high-resolution electron microscopy
- 2004
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Ingår i: Defect and Diffusion Forum. - Zürich : Trans Tech Publications. - 1012-0386 .- 1662-9507. ; 226-228, s. 11-30
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Tidskriftsartikel (refereegranskat)abstract
- The core structures of perfect 60 and edge dislocations in diamond are investigated atomistically in a density-functional based tight-binding approach, and their dissociation is discussed both in terms of structure and energy. Furthermore, high resolution electron microscopy is performed on dislocation cores in high-temperature, high-pressure annealed natural brown diamond, and HRTEM image simulation allows a comparison of theoretically predicted and experimentally observed structures.
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| 3. |
- Chatzittofis, Andreas, et al.
(författare)
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HPA axis dysregulation is associated with differential methylation of CpG-sites in related genes
- 2021
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Ingår i: Scientific Reports. - : Springer Nature. - 2045-2322. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- DNA methylation shifts in Hypothalamic–pituitary–adrenal (HPA) axis related genes is reported in psychiatric disorders including hypersexual disorder. This study, comprising 20 dexamethasone suppression test (DST) non-suppressors and 73 controls, examined the association between the HPA axis dysregulation, shifts in DNA methylation of HPA axis related genes and importantly, gene expression. Individuals with cortisol level ≥ 138 nmol/l, after the low dose (0.5 mg) dexamethasone suppression test (DST) were classified as non-suppressors. Genome-wide methylation pattern, measured in whole blood using the EPIC BeadChip, investigated CpG sites located within 2000 bp of the transcriptional start site of key HPA axis genes, i.e.: CRH, CRHBP, CRHR-1, CRHR-2, FKBP5 and NR3C1. Regression models including DNA methylation M-values and the binary outcome (DST non-suppression status) were performed. Gene transcripts with an abundance of differentially methylated CpG sites were identified with binomial tests. Pearson correlations and robust linear regressions were performed between CpG methylation and gene expression in two independent cohorts. Six of 76 CpG sites were significantly hypermethylated in DST non-suppressors (nominal P < 0.05), associated with genes CRH, CRHR1, CRHR2, FKBP5 and NR3C1. NR3C1 transcript AJ877169 showed statistically significant abundance of probes differentially methylated by DST non-suppression status and correlated with DST cortisol levels. Further, methylation levels of cg07733851 and cg27122725 were positively correlated with gene expression levels of the NR3C1 gene. Methylation levels of cg08636224 (FKBP5) correlated with baseline cortisol and gene expression. Our findings revealed that DNA methylation shifts are involved in the altered mechanism of the HPA axis suggesting that new epigenetic targets should be considered behind psychiatric disorders.
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| 4. |
- Chatzittofis, Andreas, et al.
(författare)
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Normal Testosterone but Higher Luteinizing Hormone Plasma Levels in Men With Hypersexual Disorder
- 2020
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Ingår i: Sexual Medicine. - : Elsevier. - 2050-1161. ; 8:2, s. 243-250
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Hypersexual disorder as suggested to be included in the Diagnostic and Statistical Manual of Mental Disorders-5 integrates aspects of sexual desire deregulation, impulsivity, and compulsivity. However, it is unknown how it affects gonadal activity and the function of the hypothalamus-pituitary-gonadal (HPG) axis.Aim: The aim of this study was to investigate testosterone and luteinizing hormone (LH) levels in hypersexual men compared with healthy controls. Furthermore, we investigated associations between epigenetic markers and hormone levels.Methods: Basal morning plasma levels of testosterone, LH, and sex hormone-binding globulin (SHBG) were assessed in 67 hypersexual men (mean age: 39.2 years) compared with 39 age-matched healthy controls (mean age: 37.5 years). The Sexual Compulsivity Scale and the Hypersexual Disorder: Current Assessment Scale were used for assessing hypersexual behavior, the Montgomery-Asberg Depression Scale-self rating was used for depression severity, and the Childhood Trauma Questionnaire (CTQ) was used for assessing history of childhood adversity. The genome-wide methylation pattern of more than 850 K CpG sites was measured in whole blood using the Illumina Infinium Methylation EPIC BeadChip. CpG sites located within 2,000 bp of the transcriptional start site of hypothalamus pituitary adrenal (HPA) and HPG axis-coupled genes were included.Main Outcome Measures: Testosterone and LH plasma levels in association with clinical rating and a secondary outcome was the epigenetic profile of HPA and HPG axis-coupled CpG sites with testosterone and LH levels.Results: LH plasma levels were significantly higher in patients with hypersexual disorder than in healthy volunteers. No significant differences in plasma testosterone, follicle stimulating hormone, prolactin, and SHBG levels were found between the groups. There were no significant associations between DNA methylation of HPA and HPG axis-coupled genes and plasma testosterone or LH levels after multiple testing corrections.Conclusions: Subtle dysregulation of the HPG axis, with increased LH plasma levels but no difference in testosterone levels may be present in hypersexual men.
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| 5. |
- Gustafsson, Sofia B, et al.
(författare)
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High tumour cannabinoid CB(1) receptor immunoreactivity negatively impacts disease-specific survival in stage II microsatellite stable colorectal cancer
- 2011
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Ingår i: PLOS ONE. - San Francisco, CA : Public Library of Science. - 1932-6203. ; 6:8, s. 1-11
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Tidskriftsartikel (refereegranskat)abstract
- Background: There is good evidence in the literature that the cannabinoid system is disturbed in colorectal cancer. In the present study, we have investigated whether CB(1) receptor immunoreactive intensity (CB(1)IR intensity) is associated with disease severity and outcome. Methodology/Principal Findings: CB(1)IR was assessed in formalin-fixed, paraffin-embedded specimens collected with a consecutive intent during primary tumour surgical resection from a series of cases diagnosed with colorectal cancer. Tumour centre (n = 483) and invasive front (n = 486) CB(1)IR was scored from 0 (absent) to 3 (intense staining) and the data was analysed as a median split i.e. CB(1)IR <2 and >= 2. In microsatellite stable, but not microsatellite instable tumours (as adjudged on the basis of immunohistochemical determination of four mismatch repair proteins), there was a significant positive association of the tumour grade with the CB1IR intensity. The difference between the microsatellite stable and instable tumours for this association of CB(1)IR was related to the CpG island methylation status of the cases. Cox proportional hazards regression analyses indicated a significant contribution of CB(1)IR to disease-specific survival in the microsatellite stable tumours when adjusting for tumour stage. For the cases with stage II microsatellite stable tumours, there was a significant effect of both tumour centre and front CB(1)IR upon disease specific survival. The 5 year probabilities of event-free survival were: 8565 and 66+/-8%; tumour interior, 86+/-4% and 63+/-8% for the CB(1)IR<2 and CB(1)IR >= 2 groups, respectively. Conclusions/Significance: The level of CB(1) receptor expression in colorectal cancer is associated with the tumour grade in a manner dependent upon the degree of CpG hypermethylation. A high CB(1)IR is indicative of a poorer prognosis in stage II microsatellite stable tumour patients.
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| 6. |
- Lemieux, Christine L, et al.
(författare)
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Mutagenicity of an aged gasworks soil during bioslurry treatment
- 2009
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Ingår i: Environmental and Molecular Mutagenesis. - : John Wiley & Sons. - 0893-6692 .- 1098-2280. ; 50:5, s. 404-412
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated changes in the mutagenic activity of organic fractions from soil contaminated with polycyclic aromatic hydrocarbons (PAHs) during pilot-scale bioslurry remediation. Slurry samples were previously analyzed for changes in PAH and polycyclic aromatic compound content, and this study examined the correspondence between the chemical and toxicological metrics. Nonpolor neutral and semipolar aromatic fractions of samples obtained on days 0, 3, 7, 24, and 29 of treatment were assayed for mutagenicity using the Salmonella mutation assay. Most samples elicited a significant positive response on Salmonella strains TA98, YG1041, and YG1042 with and without S9 metabolic activation; however, TA100 failed to detect mutagenicity in any sample. Changes in the mutagenic activity of the fractions across treatment time and metabolic activation conditions suggests a pattern of formation and transformation of mutagenic compounds that may include a wide range of PAH derivatives such as aromatic amines, oxygenated PAHs, and S-heterocyclic compounds. The prior chemical analyses documented the formation of oxygenated PAHs during the treatment (e.g., 4-oxapyrene-5-one), and the mutagenicity analyses showed high corresponding activity in the semipolar fraction with and without metabolic activation. However, it could not be verified that these specific compounds were the underlying cause of the observed changes in mutagenic activity. The results highlight the need for concurrent chemical and toxicological profiling of contaminated sites undergoing remediation to ensure elimination of priority contaminants as well as a reduction in toxicological hazard. Moreover, the results imply that remediation efficacy and utility be evaluated using both chemical and toxicological metrics.
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| 7. |
- Lundstedt, Staffan, et al.
(författare)
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Sources, Fate, and Toxic Hazards of Oxygenated Polycyclic Aromatic Hydrocarbons (PAHs) at PAH- contaminated Sites
- 2007
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Ingår i: AMBIO: A Journal of the Human Environment. ; 36:6, s. 475–85-
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Tidskriftsartikel (refereegranskat)abstract
- In this paper we show that oxygenated polycyclic aromatic hydrocarbons (oxy-PAHs) are important cocontaminants that should be taken into account during risk assessment and remediation of sites with high levels of PAHs. The presented data, which have been collected both from our own research and the published literature, demonstrate that oxy-PAHs are abundant but neglected contaminants at these sites. The oxy-PAHs show relatively high persistency and because they are formed through transformation of PAHs, their concentrations in the environment may even increase as the sites are remediated by methods that promote PAH degradation. Furthermore, we show that oxy-PAHs are toxic to both humans and the environment, although the toxicity seems to be manifested through other effects than those known to be important for polycyclic aromatic compounds in general, that is, mutagenicity and carcinogenicity. Finally, we present data that support the hypothesis that oxy-PAHs are more mobile in the environment than PAHs, due to their polarity, and thus have a higher tendency to spread from contaminated sites via surface water and groundwater. We believe that oxy-PAHs should be included in monitoring programs at PAH-contaminated sites, even if a number of other toxicologically relevant compounds that may also be present, such as nitro-PAHs and azaarenes, are not monitored. This is because oxy-PAH levels are difficult to predict from the PAH levels, because their environmental behavior differs substantially from that of PAHs, and oxy-PAHs may be formed as PAHs are degraded.
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| 8. |
- Oberg, K., et al.
(författare)
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Comparison of monolayer films of stearic acid and methyl stearate on an Al2O3 surface
- 2001
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Ingår i: Thin Solid Films. - : Elsevier. - 0040-6090. ; 397:1-2, s. 102-8
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Tidskriftsartikel (refereegranskat)abstract
- Both stearic acid and methyl stearate chemisorbs onto an oxide surface of aluminum with an asymmetric coordination of the carboxylate group as concluded from infrared (IR) spectroscopy data. Similarities in the IR spectra of the films from the two compounds suggest that the ester is bonded in the same way as the acid, and that the ester therefore undergoes hydrolysis during the surface reaction. X-Ray photoelectron spectroscopy (XPS) and IR data are interpreted in terms of self-assembled monolayer formation and a more dense film from the carboxylic acid in comparison with that from the ester. (C) 2001 Elsevier Science B.V. All rights reserved.
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| 9. |
- Öberg, Rasmus, et al.
(författare)
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UV-induced spectral and morphological changes in bacterial spores for inactivation assessment
- 2024
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Ingår i: Journal of Physical Chemistry B. - : American Chemical Society (ACS). - 1520-6106 .- 1520-5207. ; 128:7, s. 1638-1646
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Tidskriftsartikel (refereegranskat)abstract
- The ability to detect and inactivate spore-forming bacteria is of significance within, for example, industrial, healthcare, and defense sectors. Not only are stringent protocols necessary for the inactivation of spores but robust procedures are also required to detect viable spores after an inactivation assay to evaluate the procedure’s success. UV radiation is a standard procedure to inactivate spores. However, there is limited understanding regarding its impact on spores’ spectral and morphological characteristics. A further insight into these UV-induced changes can significantly improve the design of spore decontamination procedures and verification assays. This work investigates the spectral and morphological changes to Bacillus thuringiensis spores after UV exposure. Using absorbance and fluorescence spectroscopy, we observe an exponential decay in the spectral intensity of amino acids and protein structures, as well as a logistic increase in dimerized DPA with increased UV exposure on bulk spore suspensions. Additionally, using micro-Raman spectroscopy, we observe DPA release and protein degradation with increased UV exposure. More specifically, the protein backbone’s 1600–1700 cm–1 amide I band decays slower than other amino acid-based structures. Last, using electron microscopy and light scattering measurements, we observe shriveling of the spore bodies with increased UV radiation, alongside the leaking of core content and disruption of proteinaceous coat and exosporium layers. Overall, this work utilized spectroscopy and electron microscopy techniques to gain new understanding of UV-induced spore inactivation relating to spore degradation and CaDPA release. The study also identified spectroscopic indicators that can be used to determine spore viability after inactivation. These findings have practical applications in the development of new spore decontamination and inactivation validation methods.
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