| 1. |
- Allard, Per, et al.
(författare)
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Loss of dopamine uptake sites labeled with [3H]GBR-12935 in Alzheimer's disease.
- 1990
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Ingår i: European Neurology. - 0014-3022 .- 1421-9913. ; 30:4, s. 181-5
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Tidskriftsartikel (refereegranskat)abstract
- The binding of the dopamine uptake inhibitor [3H]GBR-12935 to postmortem putamen from a control group and patients with Alzheimer's disease/senile dementia of Alzheimer type (AD/SDAT) or vascular dementia (VD) was studied. The binding density (Bmax) in AD/SDAT was significantly reduced to 50% of control. A reduction of Bmax in VD was also noted, but it did not reach statistical significance. No differences in apparent binding affinity (Kd) between controls and dementia groups were obtained. The concentrations of dopamine (DA), dihydroxyphenylacetic acid (DOPAC), 3-methoxytyramine (3-MT) and homovanillic acid were also determined. The concentrations of DA and DOPAC were reduced by 30-40% in AD/SDAT and VD, but the reductions did not reach statistical significance. The concentration of 3-MT was reduced by 40% in AD/SDAT and by 30% in VD. The [3H]GBR-12935-binding densities correlated significantly with corresponding concentrations of DA in control brains. It is suggested that the loss of [3H]GBR-12935-binding sites in human putamen in AD/SDAT reflects a degeneration of dopamine neurites.
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| 2. |
- Krantz-Rülcker, C., et al.
(författare)
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Interactions between a soil fungus, Trichoderma harzianum, and IIb metals—adsorption to mycelium and production of complexing metabolites
- 1993
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Ingår i: Biometals. - : Springer. - 0966-0844 .- 1572-8773. ; 6:4, s. 223-230
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Tidskriftsartikel (refereegranskat)abstract
- Fungi are capable of accumulating metals and, in soil, such accumulation may influence metal speciation and transport. The interactions between a common soil fungus, Trichoderma harzianum, and IIb elements were studied in the present investigation. The accumulation of the metals zinc, cadmium and mercury by starved and non-starved mycelium at different pH was determined by a batch technique using radioactive tracers; uptake of the metals was found to be large, with respective distribution coefficients of about 10(3.5), 10(2.5) and 10(4.0) for zinc, cadmium and mercury, respectively. Metal accumulation by a starved system was largely independent of pH in the range 3-9, where in a non-starved system an increased accumulation of zinc (at 10(-8) m) was observed at low pH (3-5). Potentiometric titrations performed on the two systems revealed significant differences in acid capacities, i.e. values close to zero for the starved system and 500-800 meq kg-1 for the non-starved system. The maximum metal uptake was at least 50 mmol kg-1 at pH 6.5 (calculated from adsorption isotherms). The present findings suggests that in the non-starved system a metabolite is produced and then released when the pH is within a certain range.
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