| 1. |
- Bondesson, Eva, et al.
(författare)
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Planar gamma scintigraphy - points to consider when quantifying pulmonary dry powder aerosol deposition
- 2003
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Ingår i: International Journal of Pharmaceutics. - 1873-3476. ; 251:1-2, s. 33-47
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Tidskriftsartikel (refereegranskat)abstract
- Methodological aspects of planar gamma scintigraphy used to quantify pulmonary aerosol deposition were investigated using an experimental dry powder formulation. Particles of micronized salbutamol sulphate were labelled with technetium-99m and admixed to an ordered mixture of unlabelled micronized salbutamol sulphate and larger carrier particles of lactose. The radioaerosol was administered to 24 healthy subjects, 12 in each of two consecutive, similarly designed studies. Pulmonary deposition was determined using two methods: repeated planar imaging, and pharmacokinetic assessments following charcoal co-administration to prevent gastrointestinal salbutamol absorption. After due consideration had been taken to ensure appropriate radiolabelling, image acquisition and processing procedures, a scintigraphic estimate of 26.2% (24.2-28.4%) was obtained, which did not significantly differ from the pharmacokinetic estimate of 26.4% (24.4-28.7%). In summary, pre-study validation of the radiolabelling technique, quality control of radioaerosols produced during the study, correction for re-distribution of radiolabel from the lungs, selection of regions of interest, assessment of lung contours, correction for tissue attenuation of gamma rays and establishment of the actual recovery of radioactivity in the scintigraphic measurements could potentially affect the accuracy of the scintigraphic estimate of pulmonary deposition and, thus, should be carefully considered in the design or evaluation of any such study.
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| 2. |
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| 3. |
- Åkerblom, N, et al.
(författare)
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Impact of Polychlorinated Naphthalenes (PCNs) in Juvenile Baltic Salmon, Salmo salar: Evaluation of Estrogenic Effects, Development, and CYP1A Induction
- 2000
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Ingår i: Archives of Environmental Contamination and Toxicology. - : Springer Science and Business Media LLC. - 0090-4341 .- 1432-0703. ; 38:2, s. 225-33
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Tidskriftsartikel (refereegranskat)abstract
- Juvenile Baltic salmon, Salmo salar, were fed commercial salmon food contaminated with different concentrations of polychlorinated naphthalenes (PCNs; 0.1, 1, 2, or 10 μg PCN/g food). Among other effects, possible estrogenic impact caused by PCNs were evaluated. Fish were therefore fed a diet contaminated with 17β-estradiol (E2; 0.94 or 9.4 μg E2/g food), as a positive control. After 8, 13, 17, and 41 weeks, sampling took place. Growth, liver somatic index (LSI), EROD activity, and vitellogenin content in blood plasma were measured along with morphological studies of gonads and chemical analyses to determine the effects caused by PCNs. Exposure to PCNs did not seem to have any effects on body weight gain, since the group fed the high dose followed the growth in the control group during the entirely experimental period. After 41 weeks of exposure the groups fed 2 and 10 μg PCN/g food had significantly lower LSIs compared with the control, indicating liver toxic effects of PCNs. Furthermore, a dose-dependent induction of EROD activity was found. At week 41, the control group had an activity of 4.9 ± 4.8 pmol/mg prot/min, whereas it was between 69 ± 21 and 720 ± 370 pmol/mg prot/min in the exposed groups, respectively. Examination of gonadal morphology showed that PCNs also had negative effects on ovaries in Baltic salmon, including delayed development. The distribution between females and males, gonadal morphology, and vitellogenin content in blood plasma did, however, indicate that PCNs are not capable of causing effects similar to E2 or xenoestrogens. Exposure to both of the concentrations of E2 resulted in decreased body weight gain, increased LSI, and feminization of the gonads. E2 did, however, not induce any EROD activity.
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| 4. |
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| 5. |
- Amcoff, P., et al.
(författare)
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Alterations of dopaminergic and serotonergic activity in the brain of sea-run Baltic salmon suffering a thiamine deficiency-related disorder
- 2002
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Ingår i: Journal of Fish Biology. - : Elsevier. - 0022-1112 .- 1095-8649. ; 60:6, s. 1407-1416
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Tidskriftsartikel (refereegranskat)abstract
- Baltic salmon Salmo salar females displaying wiggling behaviour had significantly lower (P<0.05) hepatic and ovarian thiamine (vitamin B1) concentrations than the normal females, confirming that they suffered from a thiamine deficiency. A significantly (P<0.05) increased monoaminergic activity was found in the telencephalon and the hypothalamus of the wiggling individuals as indicated by [5-hydroxyindoleacetic acid (5-HIAA)]: [5-hydroxytryptamine (5-HT)] and [3,4-dihydroxyphenylacetic acid (DOPAC)]: [dopamine (DA)] ratios. The 5-HIAA concentrations of wiggling individuals were significantly (P<0.05) higher in the telencephalon and the hypothalamus compared to normal fish. Wiggling fish showed significantly (P<0.05) higher concentrations of the DA metabolite DOPAC in the hypothalamus and the brain stem compared to normal fish. Furthermore, the brain stem in wiggling fish contained significantly (P<0.05) less 5-HT than in normal individuals, which was also reflected in a significant (P<0.05) increase in the (5-HIAA): (5-HT) ratio. These results demonstrate an increased serotonergic and dopaminergic activity in wiggling compared to normal fish. The altered monoaminergic activity may be directly related to altered brain thiamine metabolism, but a general stress caused by thiamine deficiency and an inability to regulate swim bladder inflation may contribute. Furthermore, a changed brain monoaminergic activity may contribute to the behaviour characterizing wiggling fish.
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| 6. |
- Norrgren, L., et al.
(författare)
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Environmental Monitoring of the Kafue River, Located in the Copperbelt, Zambia
- 2000
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Ingår i: Archives of Environmental Contamination and Toxicology. - : Springer Science and Business Media LLC. - 0090-4341 .- 1432-0703. ; 38:3, s. 334-341
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Tidskriftsartikel (refereegranskat)abstract
- Zambia is a country with an extensive mining industry with the majority of mines located in the Copperbelt province. Through this region of the country, the Kafue River drains and receives effluent water from mining activities as well as from other industrial point sources. In addition, production of agricultural products and pest control requires use of different pesticides in the area. Information on industrial and agricultural pollution has not been clearly identified in Zambia, and little attention has been paid to pollution control and possible impact of metals, pesticides, and other persistent compounds in the environment. The objective of this study was to introduce and to evaluate a few methodologies based on in situ bioassays for environmental assessment to promote sustainable and environmentally sound water resource management of the Kafue River. The results show that caged threespot tilapia exposed downstream of industrial points sources rapidly bioaccumulate several trace elements, i.e., Cd, Co, Cu, Cr, Ni. These elements also occurred in much higher concentrations in water samples downstream of the industrial area compared with a locality upstream. Furthermore, the use of a semipermeable membrane device (SPMD) for passive absorption of lipophilic pollutants in the water showed relatively high concentration of several pesticides, i.e., DDT with major metabolites, PCB, and dieldrin. The present study shows that only 2 weeks of in situ studies in waters contaminated by pollutants affects in situ exposed fish and that the correlation between water and tissue concentrations was relatively good. Both trace elements and persistent organic pollutants occurred in such high concentrations that they must be considered from ecotoxicological aspects and may affect aquatic animal health
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