Estimation of lipase activity by the diffusion plate method

A diffusion plate method for the assay of the activity of lipases in large series of samples was worked out. When using this method the maximum deviation was found to be ±3.8%.     

Stereologic studies on mitochondrial configuration in mitochondria of immobilized mice muscle

The effect of long-term (3 weeks) immobilization on mice skeletal (m. gastrocnemius) and heart muscles was investigated. Morphometric determinations were carried out for analysis surface and volume parameters in mitochondria. The ultrastructural visual evaluation of mitochondria showed that there are no difference between control and experimental groups. Morphometric data obtained from stereological analysis were shown that mitochondria in immobilized skeletal and heart muscles represent tendency of transformation to low-energy states (condensed state). Based upon data obtained in this study we recommend that these changes in mitochondria there are reversible.     

Conformational study of glycopeptides. Asn-containing peptides and their glycosylated derivatives

The conformational feature has been studied by n.m.r. spectroscopy on the compounds, Boc-Asn-NHMe, Boc-Asn-Gly-NHMe, Boc-Gly-Asn-NHMe, and their glycosylated derivatives. From the temperature dependence of the amide proton chemical shifts and vicinal coupling constants, little change was confirmed in the peptide conformation upon N-glycosylation. There is no particular intramolecular interaction between the peptide and carbohydrate moieties. Boc-Asn-Gly-NHMe takes, to some extent, a folded structure with a hydrogen bond involving the amide proton of N-methylamide group. This backbone conformation is also preferable in the corresponding glycopeptide.     

Urinary excretion of mercapturates as a biological indicator of exposure to electrophilic agents

The urinary excretion of mercapturates was followed photometrically in individuals exposed to styrene, a mixture of aromatic hydrocarbons, butadiene, vinyl chloride, 1,1,1-trichloroethane, trichloroethylene, tetrachloroethylene, 1,1,1-trifluoro-2-bromo-2-chloroethane (Halothane), ethylene oxide, epichlorhydrin, bis(chloromethyl)-ether, N-methylacrylamide, dimethylformamide, nitrosamines or cis-platinum and in groups of controls, smokers and nonsmokers, males and females, the residents of city P, industrial town V.M. and mountain village S. The increase in the urinary excretion of mercapturates was found in individuals exposed to styrene, aromatic hydrocarbons, dimethylformamide, 1,1,1-trichloroethane, and in smokers. In groups of controls, the lowest mercapturate concentrations were detected in the urine samples of nonsmokers from the mountain village S. where the degree of air pollution due to motor vehicle emissions was lowest at the time of investigation.     

Studies on lectins XLIV. The pH dependence of lectin interactions with sugars as determined by affinity electrophoresis

The pH dependence of association constants of the lectin-sugar complexes was determined by means of affinity electrophoresis. All the lectins studied (from the seeds of Dolichos biflorus, Glycine soja, Lens esculenta and Vicia cracca and of the fruiting body of Marasmius oreades) were characterized by a similar course of pH dependence of the association constants, with the maximum values at pH 7–9. For concanavalin A and the l-fucose binding Ulex europaeus lectin only the association constants at three selected pH values were determined. Concanavalin A does not interact with immobilized α-d-mannosyl residues at pH 2.3. The association constants vs. pH curves measured for lectins isolated from two different varieties slightly differ in accordance with the differences observed in the interaction of these lectins with the Sephadex gel.     

Effect of length and developmental stage of spike on the induction and differentiation efficiency of callus tissue in winter wheat. Evidence for generative development of regenerated plants

The capability of various immature inflorescence fragments of winter wheat cv. Grana to regenerate via callus was studied. The induction and regeneration efficiency of callus derived from spikes at different developmental stages (2–50 mm in length) was determined. Callus was initiated from the following organs of spike: whole segments of the youngest spikes (pairs of spikelets with a part of rachis), single spikelets and rachis of the middle stage spikes and finally individual flowers within spikelets excised from the oldest spikes. Morphogenic callus, capable to regenerate new plants, was obtained from segments derived from spikes being at early stage of organogenesis (2–10 mm in length) and distal flowers (3rd and 4th order) within spikelets of most advanced spikes (41–50 mm in length). Explants derived from spikes at the middle stage of organogenesis (11–40 mm in length) were not able to regenerate into new plants. No regeneration occurred also from developed rachis and glumes. All regenerants obtained in this study reached heading phase without additional vernalization, they were fertile and produced normally formed grains. It indicates that callus transferred the physiological state of the mother tissue i. e. the readiness to flowering.