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Biomedical subjects

J Gróf

Publications and source records attributed to J Gróf.

At least 19 recordsLinked to original sources
PubMed1987

Cytostatic peptide isolation from culture media of mouse peritoneal exudate cells.

It was found that the supernatant of mouse PEC culture medium (MCM) (both resident and casein-elicited cells) has an inhibitory effect in vitro on the incorporation of [3H]TdR into DNA of mouse spleen cells. The inhibitory effect in the MCM appears in the first 24 hr and also reaches its maximum value within this time. The inhibitory effect of this factor could not be demonstrated in the extract of freshly harvested M phi cells. The factors responsible for inhibition proved to be heat stable at 80 degrees C for longer than 30 min. Following heat treatment, the crude extract was separated into four fractions absorbing uv light at 280 nm using Sephadex G-25 column chromatography, and the most potent biologically active inhibitory factor was eluted in the last fraction. This fraction could also be obtained with a more effective permeation volume using Trysacryl GF 05 gel chromatography, and the active B fraction from this chromatography could be separated into four subfractions by isotachophoresis (ITP). The active fraction, which was obtained by Trysacryl GF 05 gel chromatography and further separated by ITP, was found to be highly inhibitory. It contained a peptide-like substance with a molecular mass of approximately 2.0 kDa and had an anionic character at pH 4.0. The inhibitory effect of MCM cannot be influenced either by inhibitory compounds of protein synthesis or by proteolysis blocking agents. Furthermore, the inhibitory effect is shown to be reversible and is more pronounced on B cells than on T lymphocytes.

Animals↗
PubMed1986

Acidic acetone extract from pregnant sow ovaries is a rich source of substances affecting uterine contractility in vitro.

Acidic acetone extract of pregnant sow ovaries was subjected to Sephadex G-25 chromatography. The solution coming from column was analysed for UV absorption, molecular weight, and also for its biological effect on a myometrium strip in vitro. This biodetection system has made it possible continuously to determine the biologically active fractions eluted from the Sephadex G-25 column. The reference materials to calibrate the Sephadex G-25 column were Blue dextran and acetone, while for calibration of the biodetection system, synthetic oxytocin was used. The extract of ovaries of pregnant sows was separated chromatographically into 8 different, biologically active fractions with distinct UV absorption and molecular weight. One of these fractions showed elution characteristics and biological effect similar to those of synthetic oxytocin in the same biodetection system. The results indicated that acidic acetone extract originating from ovaries of pregnant sows is a rich source of biologically active substances with effects on the myometrium strips in pregnancy. Partial identification of oxytocin-like substances in the ovarian extract verified the effectiveness of the biodetection system in the first steps of research to obtain new, biologically active substances from different unpurified extracts.

Acetone↗
PubMed1985

Biochemical characterization of substances with myometrium contraction inhibitory action, originated from ovaries of pregnant sows.

In order to understand life itself, we need biotechnology to purify biologically active substances as well. One of these processes results peptides with myometrium contraction inhibitory effect, originated from the ovaries of pregnant sows, but different from relaxin. After collection and acidic-acetone extraction of the ovaries (product generation, primary purification) the substance with myometrium contraction inhibitory effect was further purified on Sephadex G-25 (fine), CM-52 and again Sephadex G-25 (fine) gels (secondary purification) without loosing the bioactivity of the substance (quality control). Product analysis by analytical high performance liquid chromatography and capillary isotachophoresis were performed at this stage of the experiments. The analysis mentioned above resulted in 2-15 different subfractions in the studied extract. This shows that the biologically active ovarian extract needs further purification before the planned final amino-acid analysis is performed.

Animals↗
PubMed1984

Possible origin of amniotic fluid constituents affecting thromboplastic activity.

The clotting-accelerating activity of amniotic fluid (AF) has been known for long, but a clinical importance has only recently been attributed to this phenomenon. In order to obtain some informations on the origin of AF component(s) responsible for this action, the effects on the coagulation process of extracts prepared from the placenta, fetal membranes and fetal excretes were investigated. Normal saline extracts from the placenta, the amniotic and chorionic membranes, and those from the mucus aspirated from the upper respiratory tract of the fetuses were shown to accelerate, whereas meconium extract and untreated fetal urine were found to inhibit blood coagulation. Results presented in this paper indicate that AF components affecting the thromboplastic system in one way or other may be of both fetal and extrafetal gestational tissue origin, and that the quality of the actual effect exerted on the clotting system by AF depends on the relative amount of AF constituents oppositely affecting the hemostatic system.

Amnion↗
PubMed1984

Possible origin of amniotic fluid constituents influencing fibrinolytic activity.

An attempt was made to clarify the origin of the amniotic fluid constituents affecting fibrinolysis. For this purpose, saline extracts were prepared from various extra-fetal gestational tissues (EGT) as well as from various fetal excretory products (FEP) and their effect on an euglobinolytic system was studied in vitro. It was found that extracts from FEPs stimulated, whereas those from EGTs inhibited fibrinolysis. It is concluded that the fibrinolysis inhibiting amniotic fluid constituents originate from the placenta and the fetal membranes, whereas the fibrinolysis stimulating ones from various sources of fetal origin.

Amniotic Fluid↗
PubMed1983

Effect of hyperosmolar peritoneal dialysis fluid on the elimination of small- and medium-molecular substances.

The efficiency of peritoneal dialysis by the use of hyperosmolar dialyzing fluid (680 mOsm/1) was studied in 7 patients with chronic renal failure. The results were referred to the control values obtained in the first and in the terminal periods. In the course of treatment by means of the solution of high osmolarity the clearance of small- and medium-molecular substances increased. A significant increase in ultrafiltration was demonstrable. Protein loss and elevation of the blood glucose levels were noted as side-effects.

Adolescent↗
PubMed1983

The role of basic amino acids of the seminal plasma in fertility.

The role of basic amino acids in male infertility is discussed. The changes in the arginine, ornithine and total amino acid concentrations of the seminal plasma in various types of pathospermia are commented upon in the light of published evidence and of the authors' own observations. A recent procedure (CV-technique) introduced by the authors into the routine investigation scheme of infertility is reported. The method detects the arginine-deficient type of pathospermia, thus contributing to the possibility of its selective correction.

Amino Acids↗
PubMed1983

A rapid, routinely applicable method for the determination of the amino acid content of the ejaculate.

Examination of the amino acid content of the ejaculate was carried out from the point of view of fertility. Following a brief survey of the known examination techniques, the authors report on the experiences gained by the Van Pielsum-Sakagutchi and a thin-layer ion exchange chromatographic methods. The chromatographic videodensitometry is proposed as a suitable routine andrologic examination since it is rapid, simple and requires small sample size.

Amino Acids↗
PubMed1983

Continuous monitoring of the efficiency of haemodialysis by recording the UV transmittance of the dialysis solution.

The efficiency of haemodialysis, the elimination of uraemic retention substances of low and medium molecular weight can be continuously monitored by recording the UV transmittance at 254 nm of the dialysing solution. The method for controlling the efficiency of haemodialysis is optimal if it complies with the following requirements: No or little blood sample is needed. The elimination process can be continuously monitored. The degree of eliminating the hardly dialysable organic compounds and toxic materials can be well measured. Our method was devised to fulfil the above requirements [1]. The results obtained during routine application of the method are reported in this publication.

Adolescent↗
PubMed1982

Molecular weight distribution, diffusibility and comparability of middle molecular fractions prepared from normal and uremic sera by different fractionation procedures.

Sephadex G-25 (SG-25) chromatography of normal and uremic (U) sera yielded three (A, B, C) optically active (280 nm) fractions. Only fraction B disclosed a substantial increase in uremia that could not be counteracted by routine hemodialysis. Although middle molecules (MM) might be included in all SG-25 fractions (B greater than C greater than A), none of them was exclusively composed of MM. Solutes in U fraction B and C were found to be (a) heat stable; (b) soluble in ethanol; (c) diffusible through a Visking membrane, and (d) adsorbed by activated charcoal. Solutes in U fraction B and C and those in a toxic ethanol U serum extract could be partially or entirely recovered in the same Dowex fractions which were obtained by Dowex chromatography of native U sera. Methodical pitfalls leading to misinterpretation of molecular weight data obtained by SG chromatography and to erroneous classification of MM are also thoroughly discussed in this paper.

Chemical Fractionation↗
PubMed1982

The role of degradation of fetal haemoglobin in the energy supply of very low body weight pre-term babies.

Low body weight premature babies born before the 32nd gestational week were studied to analyse the postnatal fall in plasma haemoglobin and in quantitative changes in amino acid levels. Red blood cells of premature low body weight infants were found to disintegrate more rapidly than those of mature newborns. Thin-layer ion-exchange chromatographic studies showed that amino acids originating from the degrading haemoglobin-F lead to rise in plasma amino acids. These amino acids might play a role as substrates for gluconeogenesis in the energy supply of low body weight premature babies during the special fasting state just after birth.

Amino Acids↗
PubMed1982

Effect of immobilization by plastering on the level of various energy metabolites in skeletal muscle.

The effect of 1 to 6-week limb immobilization by plaster fixation and the resulting skeletal muscle inactivity-atrophy was studied by analysing isotachophoretically the ATP, ADP, AMP, CrP, NAD+ and Pi content of the slow-oxidative soleus, and the fast-glycolytic gastrocnemius muscle of the rabbit. ATP and CrP levels were higher in the glycolytic while NAD+ content was higher in the oxidative skeletal muscle under normal conditions. Energy homeostasis of the muscles disturbed during the first week of immobilization, and subsequently it is adapted to the inactivity by reaching a new steady state at lower energy levels. This new level as characterized by the high energy phosphate content shows no significant difference between the two muscle types.

Adenosine Diphosphate↗
PubMed1982

Utero-inhibin: a new substance inhibiting uterine contraction, isolated from amniotic fluid.

Amniotic fluid was collected from women in the 2nd trimester of their gravidity by amniocentesis and its effect on the isolated pregnant rat uterine preparation investigated. It was demonstrated that some of the amniotic fluid components partially purified by using the combination of various separation techniques stimulated, while others inhibited the contractions of the isolated rat uterine preparation. The inhibitory component, called utero-inhibin also inhibited the spontaneous contractions as well as the basal tone of the isolated rat intestinal preparation and those of the isolated human pregnant myometrium preparation. It is speculated that the inhibitory factor might play a physiological role in maintaining the resting state of human uterus during pregnancy.

Amniotic Fluid↗
PubMed1982

Elevated opioid activity in sera of chronic schizophrenics.

The effect of native serum samples from schizophrenic and control patients on the electrically induced contractions of the isolated mouse vas deferens (MVD) preparations was investigated. It was demonstrated that only the samples of schizophrenic origin elicited a naloxone dependent inhibition on the contractions of the MVD preparations, while sera from healthy individuals and those from non schizophrenic but mentally ill patients proved to be ineffective in this respect. By using ultrafiltration and gel chromatographic techniques, four fractions disclosing MVD related biological activity could be separated from schizophrenic samples. Chemical analysis revealed an elevated quantity of ninhydrin and Lowry positive materials as well as of unidentified carbohydrate components in the active fractions. Molecular mass of the serum ingredients carrying opioid activity was found to range between 0.5 and 5.0 KD. It is speculated that new appearance or the accumulation in the sera of several, and partly at least, unknown peptides and glycopeptides disclosing opioid activity might be characteristic of schizophrenia.

Animals↗
PubMed1982

Quantitative and qualitative changes in serum oligopeptide components of patients with end stage malignant tumour disease.

A number of changes in peptide components could be demonstrated in sera of patients with end stage malignant diseases. Total and free alfa amino-N content of such sera was shown to be significantly higher than those in sera of patients with no sign of malignancy. In addition, a significant increase was found in one of the serum fraction obtained by Sephadex G-25 chromatography. This increase was shown to be due to an increase in the amount of one of the isotachophoretically separated serum components of anionic character as well as to the appearance in sera of tumour bearing patients of two additional isotachophoretic components never detected in non tumour bearing patients. Based on their chromatographic behavior as well as on observations made in earlier experiments, the peptide nature of the two isotachophoretic serum components seemingly characteristic of sera of tumour bearing patients is highly probable.

Chromatography, Gel↗