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Biomedical subjects

F Boján

Publications and source records attributed to F Boján.

18 recordsLinked to original sources
PubMed1992

Marker profile, enzyme activity, and function of a human myelomonocytic leukemia cell line.

Morphological and functional characteristics of a permanent human leukemia cell line (DD) that possesses myelomonocytic features were investigated. The cells bear a second type Fc gamma receptor and form rosettes with sheep erythrocytes sensitized with rabbit IgG (EA). However, the surface-bound EA is not internalized. The cell line lacks the surface markers CD2, CD19, CD14, HLA-DR, Fc gamma receptor I, Fc gamma receptor III, and CR3. alpha 1-Antitrypsin, lysozyme, Factor XIII a subunit of blood coagulation, and acid phosphatase reactions were negative. A terminal differentiation of the DD cell line was observed when the expression of CD14, CR3, Fc gamma receptor I, and Fc gamma receptor III was induced. The DD cells induced with 12-O-tetradecanoylphorbol-13-acetate or Escherichia coli lipopolysaccharide can internalize EA via Fc gamma receptor II and complement-coated yeast in the function of the inducers. The phagocytic ability appears to be parallel with the appearance of enzymes which participate in phagocytosis.

Antigens, Surface↗
PubMed1988

Effect of enzymic (collagenase) harvesting on the intracellular Na+/K+ ratio of Swiss/3T3 cells as revealed by X-ray microanalysis.

Swiss/3T3 cell cultures were harvested with 0.05% collagenase and after centrifugation the pellet was prepared by the freeze-fracture/freeze-drying (FFFD) method for bulk-specimen X-ray microanalysis. Time-dependent variations in the intracellular monovalent elemental concentrations (Na+, K+ and Cl-) as well as of the Na+/K+ ratio were followed for 120 min subsequent to harvesting. The quantitative measurements revealed a very considerable increase in the intracellular Na+ and Cl- accompanied by a decrease in the K+ concentration as soon as 5 min after harvesting. The Na+/K+ ratio had increased by this time to about 1.5 on average. These changes indicate a sustained depolarization of the cell membrane. During the first 60 min this depolarization tended to normalize as demonstrated by an exponential decrease in the intracellular Na+ and Cl- and an increase in the K+ content involving a decrease in the Na+/K+ ratio. The total intracellular monovalent ion concentration remained almost constant during this post-harvesting period. These results suggest that harvesting represents a serious depolarizing stimulus to the cells, the consequences of which are restored only after 1-2h. These alterations should be taken into consideration during various experimental designs when using anchorage-dependent cell cultures.

Animals↗
PubMed1985

In vivo formation of a carcinogenic substance from diethyl pyrocarbonate in the presence of ammonia.

Mice of different strains have been treated repeatedly with diethyl pyrocarbonate (DEPC) and/or ammonia by gastric tube. In adult mice treated with DEPC plus ammonia, pulmonary tumours developed. However, DEPC or ammonia alone proved not to have any carcinogenic effect. When DEPC administration was followed by ammonia treatment more pulmonary tumours developed than in the case of ammonia-DEPC sequence. The shorter the time interval between DEPC and ammonia administrations the higher the number of lung tumours observed. Pulmonary tumours could not be observed in the offspring of pregnant mice treated with DEPC and ammonia or in suckling mice whose mother was treated with DEPC and ammonia. In gastric juice a new substance is formed from DEPC in the presence of ammonia. This new substance was very similar or identical to urethane according to the thin layer chromatographic investigation.

Ammonia↗
PubMed1983

Effects of urethan on lymphokine-producing activity of lymphocytes and on some functions of peritoneal macrophages in rats.

Effects of urethan on some functions of blood lymphocytes and peritoneal macrophages (PMs) of rats were studied in in vivo and in vitro experiments. The in vitro lymphokine (LK) producing activity of lymphocytes in the presence of specific antigen was depressed by urethan administered 1-5 days before the BCG sensitization. However, the drug injected after the BCG sensitization was not effective on the LK production. Urethan added to the cultures of previously BCG-primed lymphocytes did not influence the LK production. The sensitivity of glycogen-provoked PMs (pPM) to LK-induced activation and, at the same time, the 125I-IgG2a binding capacity as well as the EA rosette formation of the provoked PMs were depressed by urethan administered 1-5 days before the lavage of PMs. These functions of resident PMs (rPM) were not altered by the drug treatment. Urethan added to the cultures of resident or provoked PMs proved to be ineffective. These results led to the conclusions that urethan, after its in vivo metabolic conversion, causes an impairment of the macrophage functions in the inductive phase of the immune response and this event may be the crucial point in the immunosuppressive effect of urethan.

Animals↗
PubMed1982

Transplacental effects of carcinogens and non-carcinogens on activities of pyruvate kinase and lactate dehydrogenase as well as isozymic pattern of LDH in mouse lung.

The carcinogens, urethane (URTH), 3-methylcholanthrene (MCA) and dimethylnitrosamine (DMN) given to pregnant mice enhanced permanently the activities of pyruvate kinase (PK) and lactate dehydrogenase (LDH) in the lungs of offspring even well before the appearance of lung tumours. The noncarcinogenic analogues phenylurethane (PHUR) and pyrene (PYR), had no effect on PK or LDH activity. The non-carcinogenic pulmonary toxicant Paraquat (PAR) elicited only a temporary elevation in the activities of the enzymes tested. The H:M ratio of LDH sub-units in the lung tissue was permanently decreased by URTH administered transplacentally. PAR caused only a temporary decrease in the H:M ratio, while PHUR had no effect on the isozymic pattern of LDH.

Animals↗
PubMed1980

Effect of carcinogenic and non-carcinogenic chemicals on the activities of four glycolytic enzymes in mouse lung.

The activities of four glycolytic enzymes were measured in the lung homogenate of CFLP mice treated with a variety of carcinogens and non-carcinogens for mouse lung. The carcinogenic urethane, dimethylnitrosamine (DMNA), 3-methylcholanthrene (MCA), benzo[a]pyrene (BP), 7,12-dimethylbenz[a]anthracene (DMBA) and aflatoxin B1 enhanced the activity of hexokinase (HK), phosphofructokinase (PFK), pyruvate kinase (PK) and lactate dehydrogenase (LDH) 28 days after a single intraperitoneal administration. These carcinogens also altered the ratio of LDH H and M subunits. In contrast, under the same conditions the non-carcinogenic phenylurethane, ethylformate, chrysene, perylene and pyrene, as well as the pulmonarily toxic Paraquat, butylated hydroxytoluene (BHT) and cadmium chloride (CdCl2), did not influence either the activities of the enzymes tested or the isozyme pattern of LDH.

Animals↗
PubMed1979

Activities of four glycolytic enzymes (HK, PFK, PK, and LDH) and isozymic pattern of LDH in mouse lung tumor induced by urethan.

In the lungs of CFLP mice the activities of glycolytic key enzymes (HK, PFK, PK) and LDH as well as LDH isozymic pattern change in the course of life. The activities of these glycolytic enzymes in the lung tumors induced by urethan in CFLP mice are significantly higher than those in the normal adult lung and they are similar to those in the normal fetal lung. The isozymic pattern of LDH of pulmonary adenomas resembles that of the normal fetal lung, too.

Age Factors↗
PubMed1977

[Mycotoxicosis].

Explore the source record for details and available documents.

Food Contamination↗
PubMedDate not supplied

Activity of pyruvate kinase and lactic acid dehydrogenase in mouse lung after transplacental exposure to carcinogenic and non-carcinogenic chemicals.

The carcinogenic urethane (URTH), dimethylnitrosamine (DMN), 3-methylcholanthrene (MCA), benzo[a]pyrene (BP), 7,12-dimethylbenz[a]anthracene (DMBA) and aflatoxin B1 (B1) administered to pregnant CFLP mice increased the activity of pyruvate kinase (PK) and lactate dehydrogenase (LDH) and decreased the ratio of LDH H and M subunits in the lungs of offsprings. However, under the same conditions, the non-carcinogenic phenylurethane (PHUR), ethylformate (EF), chrysene (CHRY), perylene (PER) and pyrene (PYR), as well as the toxic Paraquat (PAR), butylated hydroxytoluene (BHT) and cadmium chloride (CdCl2), did not influence the activities of the enzymes tested.

9,10-Dimethyl-1,2-benzanthracene↗