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C Haskovec

Publications and source records attributed to C Haskovec.

At least 37 records · Page 2Linked to original sources
PubMed1992

[Use of cytogenetic and molecular biology in the detection of chronic myeloid leukemia].

The examination of the presence of Ph chromosome and of the fused gene BCR-ABL in patients with chronic myeloid leukemia (CML) is significant for the precise diagnosis and in some cases for the prognosis of the disease. We examined peripheral blood for the presence of BCR-ABL fused gene by polymerase chain reaction (PCR) in eight patients with CML consecutively cytogenetically studied before and after the bone marrow transplantation and in two patients treated with interferon. Southern blot analysis was performed before BMT in two patients and the molecular rearrangement of Ph chromosome was found. In all cases our results have proved that cytogenetic and recombinant DNA evaluations confirm each other. Due to the high sensitivity of PCR technique the minimal residual leukemia can be detected.

Blotting, Southern↗
PubMed1991

Membrane potential in human myeloid leukemia cell line ML-1: responsiveness of granulocytic and monocytic differentiated cells.

The membrane potential responsiveness of human myeloid leukemia cells (ML-1 line) was studied with the voltage sensitive fluorescent dye diS-C3-(5). The experimental procedure used in this study enabled us to assess the magnitude of the membrane potential change in cells treated with ouabain, 12-0-tetradecanoylphorbol-13-acetate (TPA) and N-formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP), relative to the membrane potential in the untreated control. Inhibition of the Na, K-ATPase by ouabain was followed by a (20 +/- 4) mV depolarization. In undifferentiated homogeneous cell population TPA caused a (19.4 +/- 4.4) mV depolarization while FMLP had virtually no effect. Cells in which granulocytic or monocytic differentiation was induced by retinoic acid or 1,25-dihydroxyvitamin D3 exhibited under the effect of TPA a (57.8 +/- 7.1) mV and (34.8 +/- 10.9) mV depolarization, respectively. A very small transient depolarization was also observed up on treating of the cells with FMLP. The changes in the membrane potential responsiveness in the induced cells are obviously connected with the cell differentiation.

Benzothiazoles↗
PubMed1990

Differentiation of human myeloid leukemia cell line ML-1 induced by retinoic acid and 1,25-dihydroxyvitamin D3.

Human myeloblastic leukemia cell line ML-1 was induced to differentiate by 1 mumol/l all-trans-retinoic acid (RA) or by 1,25-dihydroxyvitamin D3 (1,25(OH)2D3). After 4-6 days of the induction several differentiation-associated characteristics were observed: (1) Ability to stimulate respiration burst in the ML-1 induced cells as detected by nitroblue tetrazolium (NBT) test or by chemiluminescence (CL). (The percentage of the NBT-positive cells was up to 99% in the RA-induced cells and up to 85% in the 1,25(OH)2D3-induced cells.) (2) Substantially higher phagocytosis of colloid iron, latex or Staphylococcus particles was found in the induced cells. (3) The 1,25(OH)2D3-induced ML-1 cells expressed the monocytic enzyme NaF-inhibitable alpha-naphthyl butyrate esterase and the surface monocytic antigen CD-14. (4) A majority of the induced cells lost the morphological features of blast cells; while the 1,25(OH)2D3-treated cells acquired certain features of monocyte-macrophage differentiation, the RA-treated cells displayed several granulocytic characteristics. (5) Cytofluorometric DNA assay after treatment of the cells with colcemid showed that the decline observed in the growth rate of the induced cells was connected with their arrest in G1/G0 phase of the cell cycle. The obtained results indicate granulocytic differentiation of the RA-induced ML-1 cells and monocyto/macrophage differentiation of the 1,25-(OH)2-D3 induced cells.

Acid Phosphatase↗
PubMed1989

[Antibodies against granulocyte precursors in patients with neutropenia: use of the ML-1 myeloid line].

With the aid of indirect immunofluorescent test, the authors investigated antibodies in the serum of patients, which reacted against immature myeloid cells and mature granulocytes. Myeloid line ML-1, longitudinally maintained in vitro, was used as source of immature myeloid cells. 248 sera were examined and antibodies against the immature myeloid cells were detected in 8% of them. In 6 selected sera of the patients with neutropenia, the authors determined the Ig class of the identified antibody against the immature cells of the ML-1 myeloid line, against the myeloid cells of the ML-1 line differentiated with retinoic acid, respectively even the Ig class of the antibody against neutrophils. The IgM class antibody was found to have the highest frequency. Using absorption studies, the authors provided evidence that the antibody against the myeloid cells can be absorbed only by means of the cells of the myeloid line ML-1, which is demonstrated by the absence of the surface character in the mature neutrophils against which the antibody was directed. The authors discuss the outcome of their investigation aimed at making a more accurate diagnosis of immune neutropenia.

Agranulocytosis↗
PubMed1988

Acrylonitrile depletes glutathione without changing calcium sequestration in hepatic microsomes and mitochondria.

Acrylonitrile administered either in vivo or in vitro reduced the level of non-protein thiols, GSH and GSSG in rat liver (in vivo) and liver microsomes (in vitro). It neither influenced protein thiols nor calcium sequestration in the microsomes and mitochondria. The fact that the GSSG level was not increased indicates that a mere unoxidative depletion of GSH does not lead to impaired hepatocyte Ca homeostasis, which has been associated with decreased GSH:GSSG ratio. An opposite effect was caused by CCl4 which did not considerably change the protein and non-protein SH, but strongly decreased microsomal calcium sequestration.

Acrylonitrile↗
PubMed1985

Rubidium transport in X-irradiated human erythrocytes.

Outflow of 86Rb, a radioactive analogue of potassium, from human erythrocytes X-irradiated in vitro was studied with the following results. (1) The 86Rb level in the supernatants of irradiated and control cell suspensions reflected mainly 86Rb outflow and much less its active re-uptake. (2) The effect of irradiation on 86Rb outflow was more pronounced at a low temperature (4 degrees C) than at 37 degrees C; the lowest dose of X-radiation exhibiting a significant effect on 86Rb outflow at 4 degrees C was 2.5 Gy. (3) K/Rb exchange did not seem to play an appreciable role in radiation-induced 86Rb outflow. (4) Calcium and its accumulation in irradiated cells was not found to be the cause of the effect of radiation on 86Rb outflow. (5) The effect of radiation on 86Rb outflow was higher in low Na medium but it was not inhibited by bumetanide. Rb/Na counter- or co-transport do not therefore seem to be involved in radiation-induced Rb+ outflow.

Biological Transport↗
PubMed1985

Solubilization and immunochemical identification of mitochondrial glycerol-3-phosphate dehydrogenase.

Lysophosphatidylcholine (contrary to Lubrol WX, Triton X-100, digitonine and deoxycholate) solubilizes hamster brown fat mitochondrial glycerol-3-phosphate dehydrogenase without inactivation. Optimal ratio of lysophosphatidylcholine and membrane protein for solubilization of the enzyme was found to be 0.25 mg of lysophosphatidylcholine per mg protein. The activity of solubilized enzyme, however, was not affected by low concentrations of Lubrol WX, Triton X-100, digitonine, Zwittergent TM 314. Deoxycholate exhibited a pronounced inactivating effect. One-dimensional immunoelectrophoresis of the solubilized membrane proteins revealed 10 protein bands, 3-4 of which exhibited the enzyme activity. Two-dimensional immunoelectrophoresis revealed only a single main band of glycerol-3-phosphate dehydrogenase. This technique thus appears to be the best means for the identification of glycerol-3-phosphate dehydrogenase in the mixture of solubilized membrane proteins and for concentration of the enzyme activity in one major precipitating band.

Adipose Tissue, Brown↗
PubMed1978

Isolation and chemical characterization of a highly purified phytomitogen from Phaseolus coccineus seeds.

An effective lymphocyte mitogen with a low erythroagglutinating ability was isolated from the seeds of Phaseolus coccineus L. by ammonium sulphate precipitation and repeated ion-exchange chromatography on modified Sephadex. The mitogen stimulated lymphocytes at concentrations as low as 0.25 microgram/ml, the optimum concentration being in the range of 2.5-5.0 microgram/ml. This stimulating effect was completely inhibited by 5 mg/ml methyl alpha-D-mannopyranoside. Column gel filtration, disc electrophoresis on polyaceylamide gel in an alkaline medium and in the presence of sodium dodecylsulphate and the finding of a single N-terminal amino acid (alanine) showed the phytomitogen to be homogenous. Disc electrophoresis in an acid medium revealed the presence of two or three bands which are assumed to be due to aggregates of the mitogen. The minimum molecular weight, as derived from sodium dodecylsulphate electrophoresis on polyacrylamide, was 35000. The mitogen is a glycoprotein containing 10% neutral sugars and 1.3% amino sugars (glucosamine). The amino acid composition of the isolated phytomitogen is presented.

Amino Acids↗
PubMed1978

Studies on lectins. XXXVIII. Isolation and characterization of the lectin from black locust bark (Robinia pseudacacia L.).

The lectin of black locust (Robinia pseudacacia) bark was isolated by specific adsorption on formaldehyde-fixed human erythrocytes and elution with a borate solution. The lectin is homogeneous on disc electrophoresis and ultracentrifugation (s20,w = 5.8 S) but yields three bands on isoelectric focusing. It has a molecular weight of approximately 110,000 and consists of two types of subunit (mol. wt 29,000 and 31,500). Its pI is approximately 5.9; it contains high amounts of aspartic acid, threonine and serine, no cysteine and very little methionine. Also 7.2% of covalently bound neutral sugar and 0.47% of glucosamine are present. The lectin is nonspecific in agglutination of human erythrocytes, it is inhibited by high concentrations of N-acetyl-D-galactosamine and is mitogenic in rabbit lymph node lymphocytes.

Amino Acids↗
PubMed1976

Changes in agglutination of cells with H-2 antibodies or lectins and in stimulation of lymphocytes as induced by certain polymers (chondroitin sulphate/PVP/PHA/Con A/capping of H-2 antigens).

The effect of certain polymers on the course of immune interaction has been well known although its mechanism at the cellular level remains obscure. We thus affected cells in vitro with two of such substances, CS and PVP, and followed their behaviour in various assays. It was shown that in this way the agglutinability of mouse erythrocytes with H-2 antibodies or of mouse lymphocytes with threshold doses of Con A could be enhanced, antibody-induced capping of H-2 antigens on lymphocytes accelerated and PHA-induced stimulation of mouse lymphocytes inhibited. The possible mechanisms of these changes putatively mediated through the effect on the cell membrane or cell coat are discussed.

Animals↗
PubMed1976

Interaction of lectins with surface membrane receptors of animal cells. I. Factors responsible for agglutinability of human, rabbit, and sheep erythrocytes with concanavalin A.

A study of various factors influencing the Con A-mediated cell agglutinability failed to reveal any correlation between the agglutinability and the binding capacity of Con A-agglutinable and non-agglutinable human, rabbit, and sheep erythrocytes. Treatment with trypsin and neuraminidase on the one hand and chondroitin sulphate, polyvinylpyrrolidone and polylysine on the other hand made the agglutination of human erythrocytes possible, promoted the agglutination of rabbit erythrocytes, but had almost no effect on sheep erythrocytes, which agglutinated only after treatment with pronase or polylysine. The negligible effects of low temperature, NaN3, cytochalasine B and theophylline on cell agglutinability indicate that neither membrane fluidity, metabolic energy, cAMP, nor the microfilamentous apparatus are likely to play any important role in the Con A-mediated agglutination of erythrocytes. Differences in agglutinability between erythrocytes obtained from different animal species and subjected to different treatments with enzymes and polymers are explained as being due to alterations in the surface charge and the zeta potential.

Animals↗
PubMed1975

In vitro responsiveness of lymphocytes of different mouse strains to phytohaemagglutinin.

Responsiveness of spleen and lymph node lymphocytes to in vitro stimulation by phytohaemagglutinin was investigated in several mouse strains. Considerable interstain differences in RNA and DNA synthesis were found both for PHA-stimulated and unstimulated cells; the latter component thus tends to contribute to the observed over-all differences in lymphocyte responsiveness to "specific" stimulation. Of the tested strains and F-1 HYBRIDS, THE HIGHEST RESPONDERS WERE A/Ph, its F-1 hybrids with a few other strains and BALB/C. The possibility that the interstrain differences in the rate of nucleic acid synthesis and hence in lymphocyte responsiveness could be due to different sensitivity of the lymphocytes to experimental treatment was not confirmed experimentally. Relatively high rate of synthesis of nucleic acids in PHA unstimulated cells and its great interstrain variation is interpreted in terms of variation in "spontaneous" transformability.

Animals↗