Search PubMed⌕ Search

Biomedical subjects

G Elek

Publications and source records attributed to G Elek.

At least 37 records · Page 2Linked to original sources

epsilon-N-trimethyl-lysine: a natural cell component with mitogenic activity.

The blastogenic capacity of a new mitogenic agent, epsilon-N-trimethyl-lysine (TML) was examined on human peripheral blood lymphocytes. The changes in relative DNA and histone content after TML treatment testified that activated lymphocytes passed through the whole cell cycle. The comparison of the 3H-TdR incorporation rate into unseparated T-B lymphocyte and purified T lymphocyte cultures suggested a preferential effect on the thymidine incorporation of T lymphocytes. TML induced preferentially high responses in cases of blood cells taken from women. The possibility of DNA repair mechanism could be excluded. The results of combined TML-PHA treatment experiments suggested a difference in the trigger mechanism of these two mitogenic compounds.

Adult↗

Electron spin resonance (ESR) spectrum of paraffin embedded human liver tissue. A possible method for the estimation of copper content.

Human liver tissues embedded in paraffin wax for histological examination have been studied by Electron Spin Resonance (ESR) spectroscopy. A signal was detected at g approximately 2.05 section of the spectrum. The amplitude of this signal was correlated with the copper content of the embedded specimens measured by flame atomic absorption technique. The positive correlation which has been found can make ESR spectroscopy suitable for estimating the copper content of tissues without damaging the sample. The limits and errors of this method have also been analysed.

Copper↗

Analysis of the electron spin resonance spectrum of human liver tissue embedded in paraffin.

The ESR spectra of the liver samples embedded in paraffin of newborn, adult, cirrhotic and control individuals always display the g approximately 2.05 signal and occasionally also the g = 4.3 line and the signal of free radicals. In adults, the amplitude of the g approximately 2.05 signal is negatively correlated with that of the g approximately 4.3 signal; in infants aged from three months to one year this correlation is positive. The copper content of the liver is in linear correlation with the amplitude of the g approximately 2.05 signal. The hyperfine structure of the part of the g approximately 2.05 signal recorded at low magnetic field may be of three types: it may correspond to Cu2+ centers of axial symmetry of type I, II or I + II. The parameters of the signal are the following: type I center, g = 2.35 +/- 0.05, g = 2.05 +/- 0.01, A < 100 gauss; type II center, g = 2.25 +/- 0.03, g = 2.05 +/- 0.01, A = 160 +/- 20 gauss. On the basis of the amplitude of the g approximately 2.05 signal, the copper content of the liver tissue can be estimated from paraffin blocks with an error of 30%, without losing the tissue embedded for histological examination.

Adolescent↗

Immunodiffusion study on group-specific antigen of MC-29 chicken hepatoma.

Rabbit serum against crude MC-29 hepatoma extract does not contain anti-avian gs antibodies detectable by gel diffusion methods. Rabbit serum containing antibodies against purified gs 1, gs 2, gs 3 and gs 4 antigens of avian myeloblastosis virus reveals gs 1 antigen in MC-29 hepatoma extract.

Animals↗

Study on the "toxic oxygen effect" of Janus green B in mouse ascites tumour cells.

10(7) mouse ascites tumor cells/ml incubated at 37 degrees C in 0.5 to 1.0 X 10(-4) M Janus green B or in 1.0 X 10(-4) M phenazine methosulphate are destroyed in 100 per cent oxygen atmosphere but remain transplantable in nitrogen atmosphere. The "sensitizing" effect of oxygen can be substituted by SH inhibitors (iodoacetic acid, iodoacetamide and their spinlabelled variants) as well as by some nitroxide free radicals. The "oxygen effect" is blocked by mercaptoethanole or cooling. Compared with the spectrum of native cells a more symmetrical singlet of larger amplitude, approximately g = 2 value, arose in the ESR spectrum of Janus green B treated cells. The "oxygen effect" observed in the presence of Janus green B differs in several ways from the oxygen effect of ionizing radiation and from the "photodynamic" effect.

Animals↗

Electron spin resonance spectra of chicken liver and hepatoma tissue embedded in paraffin.

ESR spectra of chicken liver and hepatoma tissue embedded in paraffin display signals characteristic of free radicals and paramagnetic complexes. Owing to embedding the spectrum is altered as compared to that of the native tissue but remains characteristic of the respective tissues. The spectra of tissues embedded in paraffin allow no more than qualitative conclusions to be drawn concerning the spectra of the native tissues, even if appropriate controls are applied.

Carcinoma, Hepatocellular↗

Investigation of group-specific antigen during the culture of MC-29 hepatoma.

The short-time culture established from MC-29 chicken hepatoma was used for the analysis of cell morphology and expression of avian gs antigen. The content of gs antigen was not changed during the period of cultivation. Two morphologically different types of cells were present in tested tumour cells. Fluorescent antibody test showed the presence of gs antigen in both types of cells.

Animals↗

Electron spin resonance spectra of chicken hepatoma and liver tissue.

When studied by electron spin resonance (ESR) (Swartz et al., 1972), tumorous tissues differ from their normal equivalents in the following aspects: 1. In tumourous tissues the signal measured in the vicinity of the g=2 region of the spectrum is of a smaller amplitude or completely absent (Commoner et al., 1954; Commoner, Ternberg, 1961; Mallard, Kent, 1964; Dodd, 1973). 2. Signals attributed to certain paramagnetic metal ions are also decreased (Nebert and Mason, 1963; Swartz et al., 1973). New lines may exceptionally appear, too (Mallard, Kent, 1966). So far mostly human and mammalian tumours (hepatoma and liver tissue) induced by carcinogens have been studied. The aim of the present work was to extend these observations to a fowl tumour of viral origin.

Animals↗