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Biomedical subjects

J Csongor

Publications and source records attributed to J Csongor.

At least 37 records · Page 2Linked to original sources

The effect of thrombin activated factor XIII, thrombin and plasmin on the chemiluminescence produced by human neutrophils stimulated by opsonized zymosan (Mannozym).

Coagulation factor XIII formed by thrombin activation from zymogen factor XIII decreases the chemiluminescence (CL) of human neutrophils stimulated by opsonized zymosan (Mannozym). At high concentrations, thrombin and plasmin also decreased the CL induced by opsonized zymosan. The inhibitory effect of all the three enzymes was due to their influence on the cell membrane receptors (C3b and Fe) and not to their direct effect on opsonized Mannozym. The potential clinical role of factor XIII, thrombin and plasma in the regulation of neutrophil functions is assumed.

Cells, Cultured↗

Effect of DTNB-treatment on Ca++-sensitivity of superprecipitation and ATPase activity of actomyosin.

A light chain of 18 000 daltons of native actomyosin isolated from rabbit skeletal muscle was removed by DTNB-treatment. Investigated were the differences in superprecipitation and ATPase activity of LC2-deficient and control actomyosin. The superprecipitation of control actomyosin develops in two phases, with high amplitude and kinetics dependent on the Ca++ concentration. On the other hand, superprecipitation of treated actomyosin develops in a single phase, with low amplitude and a kinetics independent of the Ca++ concentration. The partial lack of LC2 leads to the loss of Ca++-sensitivity of ATPase activity. On the basis of the results, LC2 has been assumed to fix that conformation state of myosin heads which is required for the functioning of the troponin system on the one hand, and a cooperation between myosin heads on the other. The regulatory function of LC2 is manifest in controlling the actin-myosin-ATP interaction, at the activated state of the troponin system, in an extent depending on the actual Ca++ concentration.

Actomyosin↗

The effect of sera of patients with systemic lupus erythematosus on artificial immune complexes.

The solubilization of artificial immune complexes mediated by complements has been well-known since 1975. It is known that the process is bound to the integrity of the alternative complement pathway. The phenomenon of solubilization can be used in the investigation of the function of the complement system. We have studied the solubilization of artificial complexes containing BSA and 125I labelled anti-BSA on the effect of sera of healthy subjects and those of patients suffering from SLE. We have observed that the solubilization capacity of SLE sera is significantly lower than that of healthy persons. The decrease is the most distinct at the time of the activity of the disease.

Antigen-Antibody Complex↗

Interrelation between body composition and endocrine system in healthy elderly people.

The body composition of 40 healthy aged and 20 healthy young people was determined using a multi-isotope method. At the same time their hormonal status was assessed. A correlation between the body composition and the endocrine status was investigated. Our results concerning the body composition and the hormonal values correlate with the findings of the literature. A strong correlation was found between the plasma volume and the renin-angiotensin-aldosterone system. The interrelation could explain the reciprocal age related changes of plasma volume and the renin-angiotensin-aldosterone system. No or weak correlation could be found between the body composition and other measured hormones.

Adult↗

The importance of changes in ATP and ADP concentrations in the development of the phasic superprecipitation of actomyosin.

It has been shown previously that at physiological K+-concentrations the development of superprecipitation has a phasic character. Studying the reason of this effect, by the use of beta-32P-ADP ATP-regeneration from ADP was detected during the first phase of superprecipitation. Myokinase activity of actomyosin may be responsible for the appearance of this first phase of turbidity change of actomyosin suspension. Myokinase contributes to the stabilization of an ATP/ADP ratio within narrow limits. During the first phase of superprecipitation the ATP/ADP ratio is between these limits, while during the second phase the ratio has a low value. This phasic evolution of superprecipitation is, probably connected with the physiological functional state of the muscle (contraction or rigour).

Actomyosin↗

Immunopathologic role of proteoglycan antigens in rheumatoid joint disease.

Cell-mediated immunity to proteoglycan antigens was assessed by leucocyte migration inhibition and by lymphocyte stimulation tests in patients with rheumatoid arthritis or with ankylosing spondylarthritis, in patients with relapsing synovitis after a single trauma to their knee joints, and in healthy donors. Both tests revealed a sensitization in most of the patients examined with various proteoglycan antigens derived from human cartilaginous tissues, rheumatoid synovial fluid, and species-common antigen of bovine nasal cartilage. Antibodies against proteoglycan antigens of human articular cartilage were detected by solid-phase radioimmunoassay in eleven out of twenty-nine sera from patients with rheumatoid arthritis and in four out of six rheumatoid synovial fluids. The results suggest that the cartilage antigenic components released by an inflammatory process or trauma may trigger a vicious circle of chronic inflammation and joint destruction.

Adult↗

Factors influencing the uptake of DNA by Neurospora crassa.

Under optimal conditions intact Neurospora crassa cells incorporated nearly the same amount of 3H-labelled DNA as that of the endogenous DNA content of cells. After 18 h of incorporation more than 80 per cent of the radioactivity was retained in the cells. A maximum uptake of exogenous DNA occurred at 28 degrees C, pH 6.35, in the presence of 100 mM calcium when the concentration of donor DNA was 150 micrograms/ml. Denatured DNA was incorporated at a higher rate than native DNA. The present findings suggest that the uptake of DNA by Neurospora crassa is a biologically active process.

Biological Transport↗

On the metabolic radioprotection.

The effect of different factors (0.025 mol/l of cysteine, 0.0003 mol/l of iodoacetamide, 0.328 mol/l of hydroxyurea, deprivation of glucose or essential amino acid and uracil from the medium) on the resistance to gamma rays was studied in the cells of E. coli TAU- during the logarithmic phase. The resistance to gamma rays was also investigated during the stationary phase. It was established that treatments, including reversible inhibition of cell division and unbalance of macromolecular synthesis of a type in which the DNA synthesis was continued without a simultaneous RNA- and protein synthesis enhanced the radioresistance. This type of asynchrony of macromolecular synthesis could increase radioresistance by promotion of repair processes of single-strand breaks in DNA after a single dose of 15 krads irradiation. For this latter studies E. coli K12 (AB 2497) strain and the technique developed by McGrath and Williams was used.

DNA, Bacterial↗

Effects of centrophenoxine on body composition and some biochemical parameters of demented elderly people as revealed in a double-blind clinical trial.

A double-blind clinical trial was performed on 50 persons (25 men, 25 women, average age 77 years) suffering from dementias of medium level (DSM III, Category 1, ICD No. 299). All subjects were residents in an old age home. The patients were treated first for 2 weeks by placebo tablets. During this period, body composition parameters were determined and these data served as controls. This was then followed by an 8-week-long treatment with the nootropic drug, centrophenoxine (CPH), 2 g/day distributed in 2x2 tablets of Helfergin(500) (Promonta, Hamburg, F.R.G.), or placebo tablets of identical size. After 8 weeks the laboratory tests were repeated again. The randomization code for verum or placebo treatment was revealed only after completing the trial. Four dropouts occurred during the treatment period. The total body water, extracellular water volume and exchangable Na(+) were determined by means of radioisotope methods. Plasma volume (PV) was measured by indocyanine-green dilution test. Body weights were also recorded. From the above data further parameters could be calculated. Serum lipid data as well as several hormone levels were also checked in the blood samples. The main results were better performance in psychometric tests (Pék et al., 1989) and a significant increase of the average intracellular water content (2.2-2.5% by weight) in the verum-treated group. The rehydration of the intracellular mass due to CPH treatment is consistent with the OH(*.) free radical scavenger properties of CPH and the predictions of the membrane hypothesis of aging.

Clinical Trial↗

Age-dependent changes of K-elastin stimulated effector functions of human phagocytic cells: relevance for atherogenesis.

Effector functions of the elastin receptor on human phagocytic cells from young and older individuals were studied. In cells of young healthy subjects the elastin peptides, the agonists of receptor, stimulated both superoxide anion release from PMNs and phagocytosis of coated human red cells by monocytes. Elastin appeared to inhibit the cholesterol synthesis in monocytes, measured by the incorporation of 14C-acetate. In comparison with phagocytic cells of young (< or = 25 +/- 6 years) subjects. PMNs of elderly donors (> or = 75 +/- 10 years) bore a similar number of binding sites for soluble elastin peptides, and the affinity of the elastin receptor was unchanged as shown by Scatchard analysis. The phagocytosis of coated human red cells stimulated by elastin peptides was also similar in the two age groups. However, several differences were found between phagocytic cells of young and elderly donors 1) PMNs of elderly released increased amounts of elastase from both resting and elastin peptide stimulated cells, and 2) monocytes of elderly showed a lack of inhibition of cholesterol synthesis by elastin peptides when maintained in cholesterol-free medium. These changes in effector functions of phagocytic cells from elderly donors might contribute to the age-dependent increase of susceptibility to the development of atherosclerotic lesions.

Adult↗