| 1. |
- Håkansson, H., et al.
(författare)
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In vivo and in vitro toxicity of fractionated fish lipids, with particular regard to their content of chlorinated organic compounds
- 1991
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Ingår i: Pharmacology and Toxicology. - : Wiley. - 0901-9928 .- 1600-0773. ; 69:6, s. 459-471
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Tidskriftsartikel (refereegranskat)abstract
- Six different lipid matrices (the intact lipid (IL), four lipid fractions with different polarity, and the free fatty acids (FFAs) obtained by hydrolysis of the triacylglycerol (TAG) containing fraction) were obtained from salmon (Salmo salar) and eel (Anguilla anguilla), each collected at a contaminated and a comparatively uncontaminated catch site along the coast of Scandinavia. The lipid matrices were studied in toxicological test systems representing various biological functions of different organ systems from several species and trophic levels. The results were evaluated with particular respect to the concentrations of extractable organically bound chlorine (EOCl) in the matrices tested. In some test systems, the specimens with a higher EOCl concentration appeared to be more toxic. For example, the TAG containing fraction (F2) from Idefjord eel, having a higher EOCl content than F2 from Oslofjord eel, reduced the number and hatchability of eggs laid by zebrafish. Both IL and F2 of Idefjord eel increased mortality and reduced the oxygen/nitrogen-ratio in blue mussels. Non-polar compounds (F1) from Bothnian Sea salmon induced 7-ethoxyresurofin O-deethylase (EROD) activity in rainbow trout hepatocytes, whereas F1 from Senja salmon did not. F1 from Bothnian Sea salmon also reduced the number of T-cells in foetal mouse thymus anlagen in vitro compared with the cell number in anlagen exposed to F1 from Senja salmon. A positive correlation between EOCl concentration and test response was found for EROD activity in rainbow trout hepatocytes and for ATP-leakage in Erlich ascites tumour cells when testing the phospolipid containing fraction (F4). However, in most test systems the fish oils, irrespective of EOCl content, were of low toxicity, and the observed effects need to be verified in future studies.
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| 2. |
- Bohm, S., et al.
(författare)
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Cooperating nonconsensus cAMP-responsive elements are mediators of adrenocorticotropin-induced VL30 transcription in steroidogenic adrenal cells
- 1993
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Ingår i: Journal of Biological Chemistry. - : American Society for Biochemistry and Molecular Biology. - 0021-9258 .- 1083-351X. ; 268:6, s. 3952-3963
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Tidskriftsartikel (refereegranskat)abstract
- Pituitary-derived trophic hormones regulate cell-type-specific expression of VL30 retrotransposons in tissues that are engaged in steroidogenesis. We show that adrenocorticotropic hormone and forskolin induced VL30 transcription in the steroidogenic adrenal cell line Y1 and that the transcriptional activation was cell type- and protein kinase A-dependent. Three novel cAMP-responsive elements (CREs), within the VL30 long terminal repeat, were identified and shown to activate transcription synergistically when templates bearing multiple sites were compared with templates bearing a single site. This type of regulation was evident only in forskolin-treated cells, and the response elements were found to be inactive as mediators of constitutive transcription. In vitro binding analyses indicated that a consensus CRE and the nonconsensus VL30 CREs differ with respect to binding affinity and specificity to a number of nuclear factors that were identified to be related to proteins within the CREB, Jun, and C/EBP families of transcription factors. The relatively low affinity and/or a restricted binding specificity of the VL30 CREs made it possible to detect forskolin-induced binding of CREB- and Jun-related proteins to these sequences. We suggest that cAMP-induced transcription, specific for steroidogenic cells, can be mediated by a novel type of nonconsensus CREs and that the mechanism for this type of gene regulation is distinct from that mediated through a consensus CRE. We also report the identification of a novel factor, distinct from previously characterized CRE-binding proteins, that constitutively binds to the identified CREs.
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| 3. |
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| 4. |
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| 5. |
- Garcia-Guzman, M, et al.
(författare)
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Characterization of recombinant human P2X4 receptor reveals pharmacological differences to the rat homologue.
- 1997
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Ingår i: Molecular Pharmacology. - 0026-895X .- 1521-0111. ; 51:1, s. 109-18
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Tidskriftsartikel (refereegranskat)abstract
- We isolated a cDNA from human brain encoding a purinergic receptor that shows a high degree of homology to the rat P2X4 receptor (87% identity). By fluorescence in situ hybridization, the human P2X4 gene has been mapped to region q24.32 of chromosome 12. Tissue distribution analysis of human P2X4 transcripts demonstrates a broad expression pattern in that the mRNA was detected not only in brain but also in all tissues tested. Heterologous expression of the human P2X4 receptor in Xenopus laevis oocytes and human embryonic kidney 293 cells evoked an ATP-activated channel. Simultaneous whole-cell current and Fura-2 fluorescence measurements in human embronic kidney 293 cells transfected with human P2X4 cDNA allowed us to determine the fraction of the current carried by Ca2: this was approximately 8%, demonstrating a high Ca2+ permeability. Low extracellular Zn2+ concentrations (5-10 microM) increase the apparent gating efficiency of human P2X4 by ATP without affecting the maximal response. However, raising the concentration of the divalent cation (> 100 microM) inhibits the ATP-evoked current in a non-voltage-dependent manner. The human P2X4 receptor displays a very similar agonist potency profile to that of rat P2X4 (ATP > > 2-methylthio-ATP > or = CTP > alpha, beta-methylene-ATP > dATP) but has a notably higher sensitivity for the antagonists suramin, pyridoxal-phosphate-6-azophenyl-2',4'-disulfonic acid, and bromphenol blue. Chimeric constructs between human and rat isoforms as well as single-point mutations were engineered to map the regions responsible for the different sensitivity to suramin and pyridoxal-phosphate-6-azophenyl-2'4'-disulfonic acid.
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| 6. |
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| 7. |
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| 8. |
- AliRiahi, M, et al.
(författare)
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Three-dimensional image of the Moho undulations beneath the Gulf of Bothnia using wide-angle seismic data
- 1997
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Ingår i: GEOPHYSICAL JOURNAL INTERNATIONAL. - : BLACKWELL SCIENCE LTD. - 0956-540X. ; 129:2, s. 461-471
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The BABEL marine seismic experiment has been carried out to investigate the lithospheric structure and antecedent tectonic signatures of the Baltic Shield, including the Archaean-Proterozoic collisional structure in the northern part of the Gulf of Bothni
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| 9. |
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| 10. |
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| 11. |
- Antzutkin, Oleg, et al.
(författare)
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Molecular motion of the Morpholin-1-yl radical in CF2 ClCFCl2 as studied by ESR : use of residual anisotrophy of powder spectra to extract dynamics
- 1993
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Ingår i: Chemical Physics. - 0301-0104 .- 1873-4421. ; 169:2, s. 195-205
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Tidskriftsartikel (refereegranskat)abstract
- The dynamics of the deprotonated neutral morpholin-1-yl radical, trapped in a halocarbon matrix, CF2ClCFCl2, has been studied utilizing electron spin resonance (ESR) spectroscopy. The experimental lineshapes of the radical exhibit an alterating line-width effect in the temperature range 105-144 K. The major changes of the ESR lineshape were governed by the averaging of the nitrogen hyperfine anisotropy while no exchange of the isotropic hyperfine coupling constants was observed. Geometrical parameters specifying the restricted anisotropic rotation of the whole radical trapped in the matrix could be extracted. Two methods for simulating anisotropic exchange broadened ESR spectra, the secular and non-perturbative, were utilized to investigate the dynamics of the radical. A surprisingly simple ''three-site'' jump model with a barrier of almost-equal-to 3.6 kcal/mol can be applied in the simulation of the experimental spectra. It has been shown that the secular method cannot reproduce the exchange broadened ESR spectra of systems with large hyperfine anisotropy undergoing large internal reorganisation.
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| 12. |
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| 13. |
- Antzutkin, Oleg, et al.
(författare)
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Optically dectected ESR (OD-ESR) of iron-radical pairs in colored solutions : observation of transient trans-Azobenzene radical cation
- 1993
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Ingår i: Applied Magnetic Resonance. - : Springer- Verlag. - 0937-9347 .- 1613-7507. ; 5:1, s. 77-86
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Tidskriftsartikel (refereegranskat)abstract
- Trans-azobenzene dissolved in different liquid hydrocarbons absorbs fluorescence arising from all acceptors previously used in Fluorescence Detected Magnetic Resonance (FDMR) and Optically Detected ESR (OD ESR) spectroscopy making optical detection impossible. In this report a new acceptor, rubrene, having sufficient quantum yield of fluorescence in the red band 550-620 nm, has been proven successful. OD ESR spectra of the radical-ion pair trans-azobenzene+/rubrene- were detected in liquid squalane (2,6,10,15,19,23-hexamethyl-tetracosane) solution in the temperature range 294-243 K. The experimental isotropic hyperfine splittings of the radical cation of trans-azobenzene (a(N) = 1.4 mT) have been compared with those from MNDO/INDO calculations and with those of earlier work using freon matrix studies.
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| 14. |
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| 15. |
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| 16. |
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| 17. |
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| 18. |
- Galanti, M. Rosaria, et al.
(författare)
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Diet and the risk of papillary and follicular thyroid carcinoma : A population-based case-control study in Sweden and Norway
- 1997
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Ingår i: Cancer Causes and Control. - 0957-5243 .- 1573-7225. ; 8:2, s. 205-214
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Tidskriftsartikel (refereegranskat)abstract
- A population-based case-control study was conducted in two regions of Sweden and Norway to investigate the association between dietary habits and the risk of thyroid cancer. The consumption of selected foods was reported in a self-completed food-frequency questionnaire by 246 cases with histologically confirmed papillary (n = 209) and follicular (n = 37) thyroid carcinoma, and 440 age- and gender-matched controls. Odds ratios (OR) and their 95 percent confidence interval (CI) were calculated as estimates of the relative risk using conditional logistic regression. High consumption of butter (OR = 1.6, CI = 1.1-2.5) and cheese (OR = 1.5, CI = 1.0-2.4) was associated with increased risks. Residence in areas of endemic goiter in Sweden was associated with an elevated risk, especially among women (OR = 2.5, CI = 1.3-4.9). High consumption of cruciferous vegetables was associated with increased risk only in persons who ever lived in such areas. A decreased risk was associated with consumption of iodized salt in northern Norway, and with use of iodized salt during adolescence among women (OR = 0.6, CI = 0.6-1.0). The results of this study suggest a role of diet and environment in the risk of thyroid cancer.
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| 19. |
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| 20. |
- Ivanov, Alexander V., et al.
(författare)
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Bis(diethyldithiocarbamato)pyridinezinc(II) and -copper(II) clathrates M(Edtc)2Py·nL (L = CH2Cl2 and CHCl3; n = 1 and 0.5) : Molecular and crystal structures and EPR and high-resolution solid-state (13C, 15N) NMR spectra
- 1999
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Ingår i: Russian journal of coordination chemistry. - 1070-3284 .- 1608-3318. ; 25:8, s. 543-555
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Tidskriftsartikel (refereegranskat)abstract
- X-ray diffraction analysis, EPR, and high-resolution solid-state (13C, 15N) NMR spectroscopy were used to examine structural organization and spectral properties of six bis(diethyldithiocarbamato)pyridine-zinc(II) and copper(II) solvates with dichloromethane and chloroform, M(Edtc)2Py·nL (n = 1 and 0.5). Typical of the clathrate-type structures, the compounds are penetrated by the ordered molecular channels filled with chemically nonbonded chlorohydrocarbon molecules. At the molecular level, the geometry of coordination polyhedra of complexing atoms is intermediate between trigonal bipyramidal and square pyramidal (the contribution of the square-pyramidal component is quantitatively estimated for the zinc clathrate). Accordingly, the ground state of the unpaired electron in the copper(II) compounds is a combination of the dx2-y2 and dz2 orbitals. It is shown that the nonequivalence of the Edtc- ligands in zinc(II) clathrates manifests itself both magnetically and structurally. The chlorine atoms of the solvate dichloromethane molecules, unlike chloroform molecules, are disordered over the two structural positions with different multiplicities. The 13C and 15N NMR signals are assigned to the atomic positions in the resolved molecular structures
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| 21. |
- Ivanov, Alexander V., et al.
(författare)
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Bis(diethyldithiocarbamato)pyridinezinc(II) and copper(II) clathrates with pyridine: Molecular structure and EPR and high-resolution solid-state (13C, 15N) NMR spectra
- 1998
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Ingår i: Russian journal of coordination chemistry. - 1070-3284 .- 1608-3318. ; 24:9, s. 645-654
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Tidskriftsartikel (refereegranskat)abstract
- EPR, high-resolution solid-state (13C, 15N) NMR, and X-ray diffraction methods were used to study bis(diethyldithiocarbamato)pyridinezinc(II) and copper(II) clathrates with pyridine, M(EdIc)2Py · Py. The structural functionalities of the Py molecules in these clathrates were found to be different: one of them is coordinated to the complexing atom, while the other (solvate) is hydrogen-bonded to the sulfur atom of one of the ligands. The heterocycle of the uncoordinated Py molecule was found to be geometrically distorted. The structures of the copper and zinc coordination polyhedra are close to trigonal-bipyramidal: two sulfur atoms and the nitrogen atom of pyridine form the equatorial plane; another two sulfur atoms occupy axial positions at larger distances. EPR spectra of the magnetically diluted copper(II) clathrate exhibit well-resolved SHFS from the nitrogen atom of Py, owing to the contribution of the dz2 orbital to the ground-state wave function of the unpaired electron. The NMR data suggest that the nitrogen atoms of the Edtc- ligands are magnetically inequivalent and that the 15N chemical shift of the uncoordinated Py molecule changes in an unusual fashion. Signal assignment was carried out for the experimental 13C and 15N NMR spectra
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| 22. |
- Ivanov, Alexander V., et al.
(författare)
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Clathrate Formation of Bis(diethyldithiocarbamato)pyridinezinc(II) and Bis(diethyldithiocarbamato)pyridinecopper(II) with Benzene by EPR, High-Resolution Solid-State 13C and 15N NMR, and X-ray Crystallography
- 1998
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Ingår i: Russian Journal of Inorganic Chemistry. - 0036-0236 .- 1531-8613. ; 43:9, s. 1368-1376
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Tidskriftsartikel (refereegranskat)abstract
- The structures of the clathrates of bis(diethyldithiocarbamato)pyridinezinc(H) and-copper(II) with benzene were studied by EPR, high-resolution solid-state 13C and 15N NMR, and X-ray crystallography. The geometry of the coordination polyhedra in the clathrates M(EDtc)2· Py · C6H6is close to trigonal-bipyramidal. Two short M-S bonds and the M-N bond form the equatorial plane, and two long M-S bonds point toward the axial positions. For the magnetically diluted copper(II) clathrate, the hyperfine structure can be observed at low temperatures due to the nitrogen atom of pyridine, which is associated with the contribution of the dz2orbital to the ground-state wave function of the unpaired electron. The 13C and 15N NMR signals were assigned.
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| 23. |
- Ivanov, Alexander V., et al.
(författare)
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Structure, EPR, and 13C and 15N NMR of Clathrates of Bis(diethyldithiocarbamato)pyridinezinc(II) and Bis(diethyldithiocarbamato)pyridinecopper(II) with 1,2-Dichloroethane
- 1999
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Ingår i: Russian Journal of Inorganic Chemistry. - 0036-0236 .- 1531-8613. ; 44:10, s. 1605-1614
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Tidskriftsartikel (refereegranskat)abstract
- The structural organization of the clathrates of bis(diethyldithiocarbamato)pyridinezinc(II) and -copper(II) with 1,2-dichloroethane, M(Edtc)2Py · L, was studied by EPR, high-resolution solid-state 13C and 15N NMR, and X-ray crystallography. The clathrates contain typical molecular channels and cavities, which accommodate chemically unbound dichloroethane molecules. At the molecular level, the geometry of the zinc and copper coordination polyhedra is intermediate between a trigonal bipyramid and a square pyramid. The ground state of the unpaired electron of copper(II) is a result of mixing the dx2-y2 and dz2 orbitals. The Edtc ligands incorporated in the zinc(II) clathrate are somewhat nonequivalent, both magnetically and structurally. The chlorine atoms of the 1,2-dichloroethane molecule are disordered over two structural positions with different occupancies, which may point to the occurrence of several conformations. The 13C and 15N NMR signals were assigned based on combined analysis of available structural and NMR data
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| 24. |
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| 25. |
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| 26. |
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| 27. |
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| 28. |
- Lund-Hansen, LC, et al.
(författare)
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Vertical sediment fluxes and wave-induced sediment resuspension in a shallow-water coastal lagoon
- 1999
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Ingår i: ESTUARIES. - : ESTUARINE RES FEDERATION. - 0160-8347. ; 22:1, s. 39-46
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The present study describes variations in the vertical fluxes measured concurrently with sediment traps at both a shallow water (4 m) and a deeper water (7.5 m) position in a coastal lagoon in April 1995. A tripod equipped with five sediment traps (trap o
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| 29. |
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| 30. |
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| 31. |
- MANKOWITZ, L, et al.
(författare)
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Adrenocorticotrophic-hormone-dependent regulation of a mu-class glutathione transferase in mouse adrenocortical cells
- 1995
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Ingår i: The Biochemical journal. - : Portland Press Ltd.. - 0264-6021 .- 1470-8728. ; 305305 ( Pt 1), s. 111-118
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Tidskriftsartikel (refereegranskat)abstract
- Three different forms of glutathione transferase (GST) have been resolved in the two mouse adrenal tumour cell lines Y1 and Kin 8. Two of these belong to the mu and pi classes respectively. The third form is so far unidentified. In the Y1 cells, the levels of the mu form (mGTmu1) and the unidentified form, are both down-regulated in the presence of adrenocorticotrophic hormone (ACTH) while the pi form is unaffected. The Kin 8 cell line is derived from Y1 cells and harbours a defect in the cyclic AMP (cAMP)-dependent protein kinase, making it refractory to cAMP-dependent regulation of several enzymes. The GST levels in this cell line were unaffected by ACTH. Also, the steady-state levels of mGTmu1 mRNA were much lower in Y1 cells treated with forskolin (which activates adenylate cyclase) compared with control cells, but there was no difference in mGTmu1 mRNA levels between control and forskolin-treated Kin 8 cells. This indicates that the ACTH-dependent regulation of the mu class GST is pre-translational and that a functional cAMP-dependent protein kinase is required for the regulation. We have further shown that the difference in mRNA steady-state levels between control and forskolin-treated Y1 cells is abolished when transcription is inhibited by actinomycin D. In light of the stability of mGTmu1 mRNA, it would appear most likely that actinomycin D inhibits the transcription of short-lived factors which regulate the turn-over of mGTmu1 transcripts in response to changes in intracellular cAMP levels.
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