Poly-N-acetyllactosamines synthesized by cultured Ehrlich carcinoma cells: application of endo-beta-galactosidase C for analysis of the terminal structure

Poly-N-acetyllactosamines were prepared from Ehrlich carcinoma cells cultured in the presence of [14C]galactose. Methylation analysis indicated that 31% of the galactose was in the non-reducing end. Of it, 77% was cleaved by alpha-galactosidase, and 56% was released as a disaccharide by endo-beta-galactosidase C. Methylation analysis confirmed that the released disaccharide was mostly Gal alpha 1----3Gal. Therefore, Gal alpha 1----3Gal structure, not Gal alpha 1----3(Gal alpha 1----6)Gal structure, was the major alpha-galactosyl structure in the poly-N-acetyllactosamines synthesized. Furthermore, alpha-galactosidase digestion did not change the content of disubstituted galactosyl residues. Thus, Gal alpha 1----3(Gal alpha 1----6)Gal structure, which was suggested to be the sole non-reducing terminal structure of poly-N-acetyllactosamines of Ehrlich carcinoma cells, was not detected in significant amounts under the present experimental conditions.     

Salicylate-promoted permeation of cefoxitin, insulin and phenylalanine across red cell membrane. Possible mechanism

Uptake of sodium cefoxitin, D-phenylalanine and insulin into human red blood cells was significantly enhanced by the presence of salicylate and 5-methoxysalicylate in the medium. The mechanism of adjuvant action appeared to depend on an affinity between the adjuvant and the protein fraction in the erythrocyte membrane. The inhibitory effect of DIDS and phlorizin on the salicylate-enhanced uptake of these compounds strongly suggests that the ability of salicylate to permeate the membrane may be essential for it to act as an adjuvant.     

Characterization by [3H]Dihydroergocryptine Binding of Alpha-Adrenergic Receptors in Neuroblastoma × Glioma Hybrid Cells

[3H]Dihydroergocryptine ([3H]DHE) was shown to bind to sites in membranes from neuroblastoma X glioma hybrid cells (NG 108-15) that had the characteristics expected of alpha-adrenergic receptors. The binding was saturable with 0.3 pmol [3H]DHE bound per mg of protein and of high affinity, with an apparent dissociation constant (KD) of 1.8 nM. The specificity of the binding site for various ligands was more similar to that of alpha 2 receptors than to that of alpha 1. No specific binding of [3H]WB-4101 was found in the membranes derived from NG 108 cells. This finding also indicated that the [3H]DHE binding site in the cell is the alpha 2 receptor. GTP lowered the affinity of agonists for the [3H]DHE binding site, although the nucleotide hardly affected the affinity of antagonists including [3H]DHE.     

Unbudded G2 as well as Gj arrest in the stationary phase of the basidiomycetous yeast Cryptococcus neoformans

Abstract Stationary-phase cells of Cryptococcus neoformans displayed two morphological characteristics: virtually all the cells were unbudded even in the early stationary phase and even when grown in rich media, and average cell size increased from that of exponential-phase cells. DNA contents for small and large stationary-phase cells were determined by quantitative fluorescence microscopy after DNA staining with propidium iodide or DAPI. Small cells contained G, DNA, whereas large unbudded cells had either a G₂ or G₁ DNA content, indicating that Cr. neoformans can enter into the stationary phase from either the G₁ or G₂ period.     

Vegetation mapping with the aid of low-altitude aerial photography

Abstract. A technique for fine-scale vegetation mapping with the aid of low-altitude aerial photography was developed. The procedure is as follows: 1. The site is divided into a lattice pattern - in case the site is too large to fit into a single photograph with satisfactory resolution. The coordinates of every lattice point are surveyed to be used as control points for geometric correction. A photograph of each block of the lattice is taken using a remote-controlled camera system lifted by a captive helium balloon. 2. The vegetation is classified on the basis of a phytosociological survey. 3. The shapes and locations of vegetation patches appearing in the photographs are entered into a computer, using a digitizer. A geometric correction is carried out through coordinate transformation referring to the coordinates of the control points and subsequently a draft vegetation map is produced. Finally, discrepancies are corrected and the map is coloured to produce the final version of the vegetation map. This technique was applied to vegetation mapping at a bar, 500 m wide and 2 km long, in the river Yoshino in Shikoku, Japan. A fine-scale vegetation map was obtained and used to analyse the influence of plants on geomorphic processes and community-specific hydrogeomorphic conditions on the bar.