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Biomedical subjects

G Elek

Publications and source records attributed to G Elek.

At least 19 recordsLinked to original sources
PubMed1989

An electron spin resonance (ESR) study of free radicals formed from hematoxylin on tissue sections after blueing (alkalization).

A free radical signal of 12 G width and g = 2.0045 can be observed in hematoxylin stained tissue blocks and sections. The amount of paramagnetic centres in stained specimens is significantly larger than in unstained ones. After alkalization simultaneously with the colour change the former free radical is detectable in hemalum precipitate and on stained paper strips. After solution of the stain in dioxane and alkalization, a well resolved hyperfine structure could be seen which could be assigned to three different radicals with the same g value as observed in the rigid matrix (tissue and paper). Quantitative evaluation of free radical concentration is also carried out for tissue sections.

Benzopyrans↗
PubMed1987

A study of free radicals in paraffin embedded and deparaffinized human heart muscle tissue using electron spin resonance (ESR).

Free radicals (spectroscopic splitting factor; g factor = 2.003-2.005) were investigated in formol-fixed, paraffin embedded heart-muscle tissue sections using electron spin resonance (ESR) spectra. Changes in signal amplitude, g factor and line width were registered during deparaffinization, chloroform-methanol extraction, vapour treatment and bromination. An attempt was made to identify the source of the ESR signals by a correlation between the signal amplitude and number of fluorescent and/or Sudan-black-positive granules counted in the tissue sections. An increase in signal amplitude, g value and line narrowing were characteristic of the ascorbyl radical after deparafinization in air. Vapour treatment revelated that the broader signal has lower g factor, a characteristic that is tentatively assigned to oxidized lipids. The bromination resistant minor fraction of free radical centres with small g factor might be associated with the pigment content of the samples.

Adult↗
PubMed1987

Large cell dysplasia of hepatocytes, is it a premalignant condition?

Incidence and character of large cell dysplasia (LCD) of liver were examined by histological, statistical and morphometric methods in an aged Middle European population. The necropsy material of 487 patients with micronodular cirrhosis and cirrhosis with primary liver tumour was studied. In addition, 50 primary tumours developed in non-cirrhotic livers, 34 metastatic tumours and 90 normal livers were examined. According to the findings, LCD often developed in aged patients. The high occurrence is presumably due to the high age. The frequency of LCD was significantly higher in active than in inactive cirrhosis. LCD could mostly be found around metastatic tumours, especially those with large, destructive foci. Sex differences occurred in a part of cases but an age dependence could not be demonstrated. Normal and dysplastic cells did not differ significantly in most morphometric parameters but there was a significant difference between tumorous and normal or dysplastic parameters. The data suggested that LCD is a secondary, reactive phenomenon occurring in various pathological processes.

Aged↗
PubMed1983

Free radical signal of bile pigment in paraffin embedded liver tissue.

A linear correlation have been found between the amplitude of the free radical signal of the electron spin resonance (ESR) spectrum of paraffin embedded liver blocks and the number of bile casts in the histological sections made from these blocks. It has been suggested that the major part of the ESR free radical signal arises from bile pigment, but the contribution of "age pigment" cannot be excluded. On the basis of model experiments the majority of these radical centers was assigned to protein bound bilirubin. In the course of histological processing more than 80% of various free radical centers arising in air dried liver tissue is extracted.

Bile↗
PubMed1982

The free radical signal of pigment gallstones.

Bile stones have been studied by Electron Spin Resonance (ESR) spectroscopy. Pigment containing stones show a 8.76 +/- 0.02 gauss wide free radical singlet at g approximately 2.003 region of the spectrum. Amplitude of this free radical signal linearly correlates with pigment content of the stone, which can be applied in the estimation of pigment content. The possible role of free radicals is suggested in the formation of pigment bile stones.

Bile Pigments↗
PubMed1982

The effect of E-N-L-trimethyllysine (TML) on the humoral and cellular immune response.

E-N-L-Trimethyllysine glutamate (TML) influences the humoral and cellular immune response of mice. Chronic pre- and post-treatment (100 mg/kg/day, 5 times) transitionally increased the anti-SRBC haemagglutinin titre of female CBA mice. After 400 r whole body irradiation, TML treatment accelerated the normalization of the haemagglutinin level. TML treatment prolonged the life-span of BDF1 hybrid mice that had first been immunized and then inoculated with L1210 cells. TML diminished the delayed type hypersensitivity reaction in vivo of irradiated and non-irradiated CBA female mice and dose-dependent decreased the spontaneous (SLMC) and antibody-dependent (ADCC) cytotoxicity of healthy human lymphocytes, in vitro. As a low molecular weight immunomodulant, TML may also be considered as a therapeutic tool.

Animals↗
PubMed1980

ESR investigation of paraffin-embedded ocular melanomas.

Ocular melanomas embedded in paraffin wax for histological examination have been studied by electron spin resonance (ESR) spectroscopy. A free-radical signal was detected at the g = 2.003 section of the spectrum. The amplitude of this signal was correlated with the number of melanin granules in microscopical slides made from the tumour. This positive correlation can make ESR spectroscopy suitable for estimating the melanin content in the embedded melanoma blocks. Additional paramagnetic signals can also be detected. The clarification of their significance needs, however, further ESR measurements.

Electron Spin Resonance Spectroscopy↗
PubMed1980

[Determination of the copper content of liver tissue from paraffin-imbedded samples by electron spin resonance spectroscopy].

The Electron Spin Resonance spectrum of human liver specimens embedded in paraffin was investigated. An easily registrable mark could be seen in the g 2.05 range of the spectrum. A correlation was detected between the amplitude of this mark of the embedded specimens and the copper content of them measured by a flame ionic-absorptive technique. Authors assume that ESR-spectroscopy is a useful tool for the estimation of the copper content of a specimen, it does interfere with the following histological processing of it. Sources of errors are shortly discussed.

Copper↗
PubMed1980

[Electron spin resonance study of melanin in paraffin-imbedded ocular melanoma specimens].

The Electron Spin Resonance (ESP) spectrum of ocular melanomas embedded in paraffin was studied. In the g approximately 2.003 range of the spectrum a mark of a free radical was detected. The correlation between the amplitude of the latter and the number of melanin granules in sections was studied. Considering the positive correlation revealed, authors believe, that ESR spectroscopy is a suitable tool for detecting melanin in paraffin embedded specimens. As an effect of oxidation or reduction melanin turns pale, however this phenomenon is not in tight connection with the decrease of the amplitude of the free-radical-mark. Very seldom different types of spectrum (peroxide, cupric ion) may appear, so it is reasonable to study large number of specimens.

Electron Spin Resonance Spectroscopy↗
PubMed1980

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↗
PubMed1979

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↗
PubMed1979

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↗
PubMed1979

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↗
PubMed1978

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↗
PubMed1977

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↗
PubMed1976

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↗