1. Influx and efflux of l-tri-[(125)I]iodothyronine with isolated rat liver parenchymal cells and their plasma-membrane vesicles were studied by a rapid centrifugation technique. 2. At 23 degrees C and in the concentration range that included the concentration of free l-tri-iodothyronine in rat plasma (3-5pm) influx into cells was saturable; an apparent K(t) value of 8.6+/-1.6pm was obtained. 3. At 5pm-l-tri-[(125)I]iodothyronine in the external medium the ratios of the concentrations inside to outside in cells and plasma-membrane vesicles were 38:1 and 366:1 respectively after 7s of incubation. At equilibrium (60s at 23 degrees C) uptake of l-tri-[(125)I]iodothyronine by cells was linear with the hormone concentration, whereas that by plasma-membrane vesicles exhibited an apparent saturation with a K(d) value of 6.1+/-1.3pm. 4. Efflux of l-tri-[(125)I]iodothyronine from cells equilibrated with the hormone (5-123pm) was constant up to 21 s; the amount that flowed out was 17.7+/-3.8% when cells were equilibrated with 5pm-hormone. When plasma-membrane vesicles were equilibrated with l-tri-[(125)I]iodothyronine (556-1226pm) 66.8+/-5.8% flowed out after 21 s. 5. From a consideration of the data on efflux from cells and binding of l-tri-[(125)I]iodothyronine to the liver homogenate, as studied by the charcoal-adsorption and equilibrium-dialysis methods, it appears that 18-22% of the hormone exists in the free form in the cell. 6. Vinblastine and colchicine diminished the uptake of l-tri-[(125)I]iodothyronine by cells but not by plasma-membrane vesicles; binding to the cytosol fraction was not affected. Phenylbutazone, 6-n-propyl-2-thiouracil, methimazole and corticosterone diminished the uptake by cells, plasma-membrane vesicles and binding to the cytosol fraction to different extents. 7. These results suggest that at low concentrations of l-tri-[(125)I]iodothyronine rat liver cells and their plasma-membrane vesicles accumulated the hormone against an apparent gradient by a membrane-mediated process. Contribution of cytoplasmic proteins to uptake by plasma-membrane vesicles was negligible. The amount of l-tri-[(125)I]iodothyronine required to achieve half-maximal uptake agrees with that occurring in the free form in the blood, conferring physiological importance to the transporting system in the plasma membrane of the liver cell.

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The data of 772 patients were analyzed for albumin, immunoglobulins, glucose, and cell counts in cerebrospinal fluid and serum in healthy controls and in patients with various neurological disorders. Using laser-nephelometric end-point determination the IgG/albumin index was established for controls; a value smaller than 0.85 was considered normal. This index was used to distinguish between impairment of the blood-brain barrier and thecal synthesis of immunoglobulins. No correlation was observed between glucose concentration and cell counts in cerebrospinal fluid. Together with the IgG/albumin index, determination of IgA and IgM increased the sensitivity to detect multiple sclerosis from 43 to 58%.

The presented paper analyses the relations between four features of geomorphology, i.e. aspect, slope, elevation and type of terrain, and tree layer diversity of forest ecosystems. The forest stand diversity is quantified by nine species diversity indices (N0, R1, R2, H¢, N1, N2, E1, E3, E5). The data used in this study come from the regional forest inventory of the Forest School Enterprise, Technical University Zvolen, Slovakia. Within this inventory, 26 permanent tracts were established in the systematic grid of 2·2 km, whereby a total of 120 sample plots were created on which 1,728 trees were measured. Analyses showed that species diversity is closely related only to elevation. However, the relationships of the individual species diversity indices to elevation are loose since the correlation coefficients do not exceed values of 0.30-0.40. The second part of this work presents spatial interpolation of species diversity degrees on a regional level using geostatistical methods. For this regionalisation, we used an indicator kriging. The final kriging map was found to be a suitable tool for the interpretation of tree species diversity over the investigated area.