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Biomedical subjects

A Christiansen

Publications and source records attributed to A Christiansen.

22 records · Page 2Linked to original sources

Effects of three fungicides alone and in combination on glutathione S-transferase activity (GST) and cytochrome P-450 (CYP 1A1) in the liver and gill of brown trout (Salmo trutta).

In order to evaluate the gill glutathione S-transferase (GST) activity as a biomarker of effect of fungicide exposure in juvenile brown trout (Salmo trutta), the fungicides propiconazole [(R,S)-1-[2-(2,4-diclophenyl)-4-propyl-1,3-dioolan-2-ylmetyl]-1H-1,2,4-triazole] and fenpropimorph [(+/-)-cis-4-[3-(4-tert-butylphenyl)-2-metyl propyl]-2,6 dimetylmorfolinc] were administrated in the water separately and together in a static system (80 microg/l for each pesticide) for 5 days. The combined fungicides gave a significant decrease in gill GST activity towards 1-chloro-2,4-dinitrobenzene (CDNB), whilst hepatic GST-activity was not significantly changed. Furthermore, continuous exposure to 540 ug/l thiabendazole[2-(thiazol-4'-yl)benzimidazole] in a flow-through system for 4 days significantly increased the gill glutathione S-transferase (GST) activity towards CDNB, whilst hepatic GST and cytochrome P450 (CYP 1A) activities were not increased by the treatment.

Animals↗

Low-resolution gamma-ray measurements of uranium enrichment.

We have developed smaller, lighter hardware (MCA and shielded detectors) that has been successfully transferred to the commercial sector. We have developed software that has received limited testing, the next release should be sufficiently robust for wide release to the general public. We have had initial success with more sophisticated analysis methods. We are pursuing medium-resolution tors and response function fitting in the expectation that both will cause significant improvements in this measurement technique.

Gamma Rays↗

Sorption of bentazone, dichlorprop, MCPA, and propiconazole in reference soils from Norway.

Sorption-desorption kinetic and isotherm studies were performed by the batch equilibrium technique in three Norwegian soils. The soils were a fine sandy loam, a loam, and a soil of highly decomposed organic material. Two commercially formulations were used, Triagran-P and Tilt, containing either a mixture of bentazone [3-isopropyl-1H-2, 1,3-benzothiadiazin-4(3H)-one 2,2-dioxide], dichlorprop [(R)-2-(2, 4-dichlorophenoxy)-propionic acid], and MCPA [(4-chloro-2-methylphenoxy)acetic acid], or propiconazole [(+/-)1-(2-(2,4-dichlorophenyl)-4-propyl-1,3-dioxolan-2-ylmethyl)-1H-1,2,4-triazole] alone. Sorption-desorption equilibrium occurred within 10 h for all pesticides. The Freundlich isotherms indicated nonlinear sorption of bentazone, dichlorprop, MCPA, and propiconazole. For all pesticides the highest Freundlich adsorption coefficient (K(F)) values were in the soil with highest organic content and lowest pH. For the fine sandy loam and loam, which are representative Norwegian agricultural soils, the results indicate that bentazone, dichlorprop, and MCPA are mobile with KF values ranging from 0.07 to 1.50 mg1-1/n kg(-1) L1/n. Propiconazole is much less mobile with KF values ranging from 27.00 to 36.02 mg1-1/n kg(-1) L1/n in the agricultural soils.

Absorption↗