Biomedical subjects

P Zajícek

Publications and source records attributed to P Zajícek.

6 recordsLinked to original sources

PubMed1992

The differentiation between freshwater and marine fish trypanosomes by lectin agglutinability.

The agglutinability of three fish trypanosomes, Trypanosoma boissoni and T. triglae senegalensis from marine fish, and T. carassii from freshwater fish was compared. The tests were performed with trypomastigotes and epimastigotes in the exponential and stationary growth phases. The simple agglutination test, performed in microwell plates, used ten purified lectins, and revealed a clear difference between marine and freshwater strains when compared for their agglutinability with the HPA lectin. Whereas the cells of T. boissoni and T. triglae senegalensis became strongly agglutinated by this lectin, those of T. carassii remained unagglutinated in the same conditions. However, the cells of T. triglae senegalensis reacted positively with ConA lectin in the stationary phase only. The differences in structure and composition of surface polysaccharides stable after prolonged cultivation in vitro are inferred on the basis of the results obtained.

Agglutination Tests↗

PubMed1991

Trypanosoma cf. carassii: the combination of malic enzyme patterns supports the theory of diploidy in trypanosomes.

Electrophoretic analysis of Trypanosoma cf. carassii strains from cyprinid fish revealed three basic types of enzyme patterns of malic enzyme (ME) in forms from culture. Two enzyme patterns were one-banded and differed only slightly in electrophoretic mobility. The third pattern consisted of three bands, the two marginals corresponding to respective bands of one-banded patterns and the third located in the middle. ME is thought to be dimeric in trypanosomes and therefore the triple-banded pattern may be regarded as the hybrid from combination of the former two. This fact supports the concept of diploidy in fish trypanosomes.

Animals↗

PubMed1991

Enzyme polymorphism of freshwater fish trypanosomes and its use for strain identification.

Sixteen strains of trypanosomes isolated from the blood of 10 freshwater fish species (all but one from South Bohemia) were characterized by enzyme analysis using disc electrophoresis in 5% polyacrylamide gel. Six enzymes were selected: ADH, LDH, MDH, ME, G6PDH and GPI. The most variable were ADH and LDH, whereas MDH, G6PDH and GPI showed the same pattern in all strains analysed. Cluster analysis indicated a very high degree of similarity among strains, even those isolated from phylogenetically distant hosts. Moreover, no correlation between enzyme pattern and host species was found.

Alcohol Dehydrogenase↗

PubMed1990

Detection and interpolation of outliers in biosignals.

Detection of outliers in recorded biosignals and their interpolation is described. The detection of outliers is based on the simple rule of 3 sigma. The subsequent interpolation is performed according to the method proposed by Brubacher and Wilson for autoregressive processes. The output of the suggested procedure can be treated by standard programs of statistical analysis as long as the influence of outliers is eliminated. The program in Fortran IV developed in the Institute of Hygiene and Epidemiology, Prague, performs automatically the detection of outliers in an input signal and their replacement by means of the proposed interpolation method.

Animals↗

PubMed1990

The interaction of fish trypanosome culture forms with some lectins.

The interactions of fish trypanosome culture forms with 11 purified lectins were compared using the agglutination test in microwell plates. Altogether, ten stocks of ten different freshwater fish species were examined. Three basic types of cell-lectin interactions were observed on the microscopical level. The strong agglutination of all stocks regardless their original host was found in the presence of Con A, PSA, RCA60, and RCA120, which implies the presence of relatively high amounts of sugar residues of D-mannose and D-galactose in the surface of culture forms of these parasites. Weak agglutinations of some stocks were observed in the presence of LCA, PNA, SBA, and WGA lectins, but their low intensity makes them not sufficiently reliable for stock characterization. The lectins UEA I, HPA, and PHA caused no agglutination. In conclusion, in case of unequivocal results no remarkable differences in the interactions of various stocks of trypanosomes culture forms with used lectins were observed. These results imply the high degree of similarity of their main cell surface saccharide structures.

Agglutination Tests↗

PubMed1988

EEG as a neurotoxicological indicator.

In living organisms both chemical agents and physical factors [16] may produce neurophysiological change that affects EEG activity. EEG signals are very suitable for non-invasive measurement of CNS reactions, but quite complicated equipment is necessary for measurement and analysis. We have implemented a system that permits the study of EEG changes both in time and frequency domains using broad-band analysis or fast Fourier transformation (FFT). Experimental animals were influenced by high doses of toxic agents (CO, CS2, barbiturates, pesticides), drugs and both non-ionizing and ionizing radiation. The EEG changes reflecting the influencing factor, respectively its quantity may be divided into several classes: (1) appearance of new activities; (2) disappearance of some activities; (3) increase of amplitudes, respectively spectral power densities (SPD) in certain frequencies; and (4) decrease of amplitudes, respectively SPD in certain frequencies. All changes are related to the controls, i.e. to the relatively normal state of CNS. Furthermore it is possible to investigate the temporal dynamics of these changes. Physiological concordance of these findings is sometimes possible from clinical analogues, but in other cases is unknown and considerable effort will be necessary to elucidate these correlates. Anyhow in some toxic substances, the EEG may be quite insensitive as an indicator of neurotoxicity. The best way to solve these problems is to collect sufficient experimental data for complex analysis. Although few relevant data are currently available, temporal and frequency domain measures of EEG activity appear to have promise as neurotoxicity indicators.

Animals↗