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PubMed1988

Transcriptional regulation of the leukocyte adherence protein beta subunit during human myeloid cell differentiation.

Adherence reactions involving human leukocytes are mediated by a family of glycoprotein surface antigens composed of three different alpha subunits designated alpha L, alpha M, and alpha X, each of which is associated with a single beta subunit in an alpha 1 beta 1 heterodimer structure. We cloned the cDNA for the common beta subunit and investigated beta subunit mRNA expression in HL-60 promyelocytic leukemia cells and human granulocytic cells. Leukocyte adherence receptor beta subunit mRNA transcripts were present in low levels in HL-60 myeloblasts and promyelocytes and increased 10-fold or greater with chemically induced differentiation to more mature granulocytes (using retinoic acid and dimethylformamide) or monocyte/macrophages (using phorbol myristate acetate). Levels of beta subunit mRNA expression were also increased both in normal human peripheral blood granulocytes and in granulocytes from patients with chronic myelogenous leukemia. Nuclear run-off assays indicated that the increased steady state level of the beta subunit mRNA in retinoic acid-differentiated HL-60 cells was secondary to enhanced beta subunit gene transcription. We conclude that mRNA levels for the beta subunit of the receptor on human leukocytes that mediates cellular adherence are increased in more mature granulocytic cells compared to immature myeloid precursors and that this enhanced mRNA expression is transcriptionally regulated.

CD18 Antigens↗
PubMed1986

A combination of a T cell-derived lymphokine differentiation-inducing activity and a physiologic concentration of retinoic acid induces HL-60 to differentiate to cells with functional chemotactic peptide receptors.

The human acute promyelocytic leukemia cell line HL-60 is induced by retinoic acid (RA) and N,N-dimethylformamide (DMF) to differentiate into cells having many of the functional and morphologic characteristics of mature granulocytes. With normal human phagocytic cells there is both superoxide anion (O2-) production and chemotaxis in response to chemoattractants such as N-formyl-methionyl-leucyl-phenylalanine (FMLP). We have now found that although HL-60 cells induced with RA alone produce O2- in response to 12-0-tetradecanoyl-phorbol-13-acetate (TPA) they are deficient in FMLP-stimulated O2- production and chemotaxis. In contrast, HL-60 induced either with DMF or with a combination of 10 nmol/L RA and a T cell-derived lymphokine, differentiation-inducing activity (DIA), produce O2- and exhibit chemotaxis in response to FMLP. The basis for these results appears to be the concentration of cell surface chemotactic peptide receptors. Thus, untreated HL-60 and HL-60 induced with either RA alone or DIA alone do not have measurable levels of FMLP receptors, whereas HL-60 induced with a combination of RA and DIA has 5,400 receptors per cell. HL-60 induced with RA and DIA plus 1 mumol/L dexamethasone have 25,000 receptors per cell and have greater chemotactic activity than HL-60 induced with the combination of RA and DIA. Thus, differentiation of HL-60 to cells with many properties of normal phagocytes can be induced in vitro by physiologic substances.

Cell Adhesion↗
PubMed1985

Combined effect of some physical and chemical factors.

The effect of simultaneous exposure to noise and dimethylformamide (DMF), noise and xylol and also vibration and lead on the metabolism of the myocardium of albino rats was studied. Combined effect of the factors was examined by the method of bifactorial design of the experiment. The animals were exposed to noise, intensity 46, 85 and 95 dB (2 and 4 hours), DMF in doses of 0.25, 1.00 and 5.00 ml . kg-1 (5 days in a week), and xylol in a concentration of 300 mg . m-3 (4 hours, 5 days in a week) for a period of 1.5 months, as also to vibration, intensity 100 Hz, 4 m . sec-2 (2 hours) and lead acetate in a dose of 20 mg . kg-1 (daily for a period of 10 days). The activity of GlDG, SucDG, LDG, G6PDG, G6P-ase, PGM and CytO in the myocardium of experimental and control animals was examined. Disturbances in metabolic and energy processes in the heart muscle were established after both isolated and combined exposure to the effect of the factors. Results of bifactorial variance analysis demonstrate that combined effect of noise and DMF results in not only independent effect of the two factors, but also in their interaction. Isolated effect of two factors (vibration and lead) can be assessed according to the relationship of some enzymes; their interaction can be noticed in GlDG, ATP-ase and G6P-ase.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphatases↗
PubMed1988

Characterization of transforming growth factor-beta-resistant subclones isolated from a transforming growth factor-beta-sensitive human colon carcinoma cell line.

Previous work indicated that transforming growth factor-beta (TGF-beta) elicits proliferation-inhibitory effects in the human colon carcinoma cell line MOSER. This paper describes the isolation and characterization of spontaneously arising subclones from this TGF-beta-sensitive parental line which were relatively refractory to the inhibitory effects of TGF-beta. While the parental cell line responded to TGF-beta with an inhibition of cellular proliferation in monolayer culture and in soft agarose, an increase in extracellular fibronectin, and a down-regulation of c-myc protooncogene expression, these responses were absent or attenuated in the sublines. However, the resistant clones retained the ability to specifically bind TGF-beta. N,N-Dimethylformamide and retinoic acid, two other agents associated with induction of a partial differentiation-like response in the MOSER parental cells (similar to that elicited by TGF-beta), inhibited the monolayer proliferation of both the parental cells and the TGF-beta-resistant sublines. Thus, the refractoriness observed in the isolated clones was relatively specific for TGF-beta.

Cell Line↗
PubMed1987

An investigation of the relationship between the hepatotoxicity and the metabolism of N-alkylformamides.

The hepatotoxicity and metabolism of the following close analogs of the hepatotoxic antitumor agent N-methylformamide (NMF) were investigated in CBA/CA mice: N-ethylformamide (NEF), dimethylformamide (DMF), formamide and N-methylacetamide (NMA). Apart from NMF only NEF was potently hepatotoxic as measured by the elevation of plasma activities of the enzymes sorbitol dehydrogenase and alanine and aspartate aminotransferases 24 hr after drug administration. In freeze-dried urine samples of mice which had received NEF or NMF, but not in the case of DMF, formamide or NMA, thioesters were detected by thin-layer chromatography. Evidence based on high-pressure liquid chromatography analysis and 400 MHz 1H-NMR and mass spectrometry suggests that the thioester metabolite of NEF is S-(N-ethylcarbamoyl)-N-acetylcysteine. It has been shown previously that NMF is metabolized to S-(N-methylcarbamoyl)-N-acetylcysteine. NEF also underwent extensive metabolism to ethylamine; similarly NMF was biotransformed to methylamine. In contrast, the urine of mice which had received DMF contained only very small amounts of dimethylamine and methylamine could not be detected as a metabolite of NMA. Instead, the major metabolite of NMA was identified by 400 MHz 1H-NMR spectrometry as N-(hydroxymethyl)acetamide. DMF is known to undergo extensive metabolism to its N-hydroxymethyl derivative. The results suggest that two metabolic pathways of N-alkylformamides can be distinguished: Hydroxylation at the alpha-carbon of the N-alkyl group and oxidation of the formyl moiety. The former pathway presumably constitutes a detoxification route, and the latter may well be associated with hepatotoxicity, and affords a glutathione conjugate, excreted in the urine as a mercapturate.

Acetamides↗
PubMed1985

[Changes in lectin-induced agglutination of human tumor cells during the process of their reversion].

The concanavalin A-induced agglutination of cultivated cells of human osteosarcoma Sa-4 was studied in the process of their reversion caused by high polar compounds, dimethylsulphoxide (DMSO) and dimethylformamide (DMFA). Primarily lectin induced an expressed ability to agglutination in Sa-4 cells. In the process of tumour cell reversion under the effect of chemical inducers their agglutination decreases. After the DMSO and DMFA removal the osteosarcoma cells return to their initial state showing a high agglutination. Other high-polar compounds (N-methylformamide and dimethylacetamide) induced no reversion of Sa-4 cells and no agglutination of them as well.

Acetamides↗
PubMed1985

Induction of terminal differentiation and nuclear appendage(s) formation in a human myeloid leukaemia cell line (HL-60).

In vitro terminal differentiation in a female myeloid leukaemia cell line (HL-60) was induced by either of the two inducing agents, dimethylsulphoxide (DMSO) and dimethylformamide (DMF). A higher frequency of more mature myeloid cells was noted with increasing concentrations of the inducing agents up to the optimal dose limits for cell viability, and with longer post-induction incubation periods. The highest percentage of polymorphs was obtained at 8 days post-induction with 1.25% DMSO and after 6 and 8 days exposure to 90 mM DMF. A proportion of polymorphs showed non-sex specific drumstick-like nuclear appendages, which were morphologically similar to the sex-specific drumsticks found in polymorphs from normal females in vivo. The correlation between the nuclear lobe counts and the frequencies of drumstick-like appendages in polymorphs was also similar to that reported for drumsticks in blood cells in vivo. The various stages of terminal differentiation and nuclear appendage formation in polymorphs under induced differentiation were similar to those occurring in vivo. Chromosomal analyses of this cell line indicated that individual cells had lost one X chromosome, and no portion of the missing X was detected in any of the rearranged chromosomes. Since no truly sex-specific drumsticks appeared to be present in the polymorphs of this cell line containing only one X chromosome, the study supports the accepted notion that there is a correlation between drumstick frequency and the presence of one versus two X chromosomes.

Cell Differentiation↗
PubMed1979

Self-association of purine base, 6-methylpurine, in water - organic component mixtures.

Thermodynamic quantities of the self-association of 6-methylpurine in water (1)-dimethylsulfoxide (DMSO) (2) mole fraction, x2 less than 0.1) and water (1) - N,N-dimethylformamide (DMF) (2) (x2 less than or equal to 1.0) mixed solvents have been obtained through heat of dilution measurements, at 25 degrees C. In the water-DMSO solvent system, the standard enthalpy and entropy changes, delta Ho and delta So, of the association exhibited an abrupt behavior. They decreased remarkbly with the the mole fraction of DMSO until about x2 = 0.012 and after that, they increased steeply. In the case of water-DMF solvent system, the values of delta Ho and delta So didn't show the abrupt behavior. They decreased steeply until about x2 = 0.1 and, at higher mole fractions, became relatively constant. These behaviors are rationalized on the basis of solvent structural effects and solvation in these association systems.

Chemistry, Organic↗
PubMed1979

Preparation of ruthenium(II) and ruthenium(III) myoglobin and the reaction of dioxygen, and carbon monoxide, with ruthenium(II) myoglobin.

Ruthenium myoglobins have been prepared by the reconstitution of horse heart apomyoglobin with either ruthenium(II) or ruthenium(III) mesoporphyrin IX (MpIX) derivatives. The ruthenium(II) and -(III) myo globins (RuMb and RuMb+, respectively) contain one ruthenium porphyrin/heme binding site; the species are readily interconverted using dithionite for reduction and bromine for oxidation. RuMb binds carbon monoxide to give the known carbonyl complex. Reversible oxygenation occurs readily with protein-free RuII(MpIX) species in dimethylformamide, but RuMb in phosphate buffer is irreversibly oxidized by dioxygen to give RuMb+ via an outer sphere electron transfer mechanism.

Animals↗
PubMed1981

Solubility of antimycotics: a problem in in vitro experiments.

An investigation of how miconazole nitrate dissolved in dimethylformamide in initial concentrations of 1,000, 500, and 100 microgram/ml may alter its concentration with storage time, is presented. The determination of miconazole nitrate was performed with high pressure liquid chromatography. After 8 hours the 1,000 microgram/ml solution was milky and the concentration of miconazole had fallen significantly. It was concluded that test agar plates or agar tubes must be made with freshly prepared and clear stock solutions, otherwise false MIC's may be obtained.

Dimethylformamide↗
PubMed1981

[Cytomorphological changes in human tumor cells exposed to high-polar compounds].

The effects of some high-polar compounds on the cytomorphological characteristics of cultured cells of synovial and osteogenic human sarcomas (Sa-2 and Sa-4) were studied. Incubation of Sa-2 cells with 1 or 2% dimethylsulfoxide (DMSO) or 100 mM dimethylformamide (DMF) during 4-6 days induced the cellular, structural and functional changes in Sa-2 cells which were considered as manifestations of pseudoepithelial differentiation. DMSO did not influence the activity of Sa-2 cell enzymes, while DMF suppressed their activity, mainly that of acid and alkaline phosphatases. DMSO and DMF induced in Sa-4 cultured the appearance of the cells which were similar cytomorphologically to normal osteoblasts. DMSO and DMF significantly depressed the activity of acid phosphatase in Sa-4 cells and transformed the positive reaction of alkaline phosphatase to the negative one. DMSO and DMF prolonged the time of the doubling of Sa-2 and Sa-4 cells. The effects of DMSO and DMF were reversible. Methylformamide (200 mM) and dimethyl acetamide (0,1 and 10 mM) did not induce analogous changes in human sarcoma cells.

Cell Division↗
PubMed1982

Dexamethasone synergistically induces chemotactic peptide receptor expression in HL-60 cells.

We have examined the effect of physiologic concentrations of dexamethasone on the induction of differentiation of the human promyelocytic leukemia cells (HL-60) and the activity of surface receptors for the f-met-leu-phe chemotactic peptide. Dexamethasone at a concentration of 500 nM was markedly synergistic with dimethylformamide and dimethylsulfoxide, but not with trans-retinoic acid, in inducing f-met-leu-phe binding by HL-60 cells. The increase in peptide binding was due to an increase in the activity of peptide receptors rather than an increase in receptor affinity. The effect of dexamethasone was relatively specific for peptide binding as there was little effect when HL-60 differentiation was assessed by cell morphology or the ability of the cells to reduce nitroblue tetrazolium. Dexamethasone alone had no reproducible effect on HL-60 differentiation as assessed by the three criteria tested. The dexamethasone concentration required for half maximal synergism correlated with the known binding constant of the hormone for steroid receptors in HL-60 cells but the effect of dexamethasone was not blocked with the steroid blocking agents 17 alpha methyltestosterone or progesterone.

Cell Line↗
PubMed1983

The effect of cryosolvents on the spectral and catalytic properties of liver alcohol dehydrogenase.

The effects of aqueous organic cryosolvents on the structural and catalytic properties of horse liver alcohol dehydrogenase (liver alcohol dehydrogenase) have been investigated. The cosolvents studied were ethanol, methanol, dimethyl sulfoxide, and dimethylformamide. All show potential as cosolvents for cryoenzymological investigations of the catalytic action of liver alcohol dehydrogenase. Limitations due to the formation of abortive complexes, or the cosolvent acting as a substrate were considered. Possible adverse structural effects of the cosolvents were ascertained by utilizing the intrinsic fluorescent properties of the enzyme. Catalytic effects, as inferred from steady state kinetic studies, were determined from both the oxidation of ethanol and the reduction of p-nitroso-N,N-dimethylaniline, a chromophoric aldehyde analog. It is concluded that each of these solvent systems may be useful for studying certain aspects of the liver alcohol dehydrogenase catalytic mechanism at subzero temperatures. Thus, although the formation of ternary enzyme-cosolvent complexes may restrict the use of cosolvents in some experiments, no apparent adverse effects are observed on the enzyme structure, coenzyme binding, or catalytic reactions. A number of interesting features were observed. For example, fluorescence titration of the native enzyme near 0 degrees C in either aqueous solution or 50% dimethyl sulfoxide revealed pK values in the vicinity of 10.5 and 12.5, in contrast to the previously reported single pK of 9.2 observed in aqueous solution at 25 degrees C.

Alcohol Dehydrogenase↗
PubMed1984

Intermittent exposure to toxic compounds in the working-zone atmosphere viewed from the aspect of hygienic standardization.

Four highly cumulative substances (carbon tetrachloride, 1,1,2,2-tetrachloroethane, benzene and dimethylformamide) were studied at two exposure levels under a monotonous and an intermittent exposure regimen in subacute experiments on rats. The biological effect produced by the intermittent concentrations as compared with the stable concentrations under time-weighted average concentrations depended both on the physiochemical properties and biological action of the poisons as well as on the exposure level. The intermittent concentration rises within certain limits (threefold as a rule) were injurious with some of the substances at a relatively high exposure level, but were not detrimental as compared with stable concentrations at a low exposure level. The other substances showed no difference between the effect of the monotonous and the intermittent regimens at either low or high exposure levels. The results of these studies form an experimental basis for a dual hygienic standardization: the establishment of maximum and average-shift admissible concentrations for the compounds studied as well as other highly cumulative substances.

Air Pollutants, Occupational↗
PubMed1984

Oxidative phosphorylation and the Pi-ATP exchange reaction of submitochondrial particles under the influence of organic solvents.

The effect of some organic solvents, in particular dimethyl sulfoxide, on oxidative phosphorylation, the Pi-ATP exchange reaction, and ATP hydrolysis has been studied in submitochondrial particles from bovine heart. The three reactions are inhibited by dimethyl sulfoxide, but with a different sensitivity. Oxidative phosphorylation takes place at considerable rates in the presence of concentrations of dimethyl sulfoxide that completely inhibit the Pi-ATP exchange reaction. The sensitivity of the Pi-ITP exchange reaction to dimethyl sulfoxide measured in the presence of electron transport is also higher than that of oxidative phosphorylation. Dimethyl sulfoxide inhibits an electrochemical H+ gradient-dependent stimulating effect of inorganic phosphate on ATP hydrolysis which is linked to the Pi-ATP exchange reaction. In the absence of phosphate or in the presence of phosphate plus uncoupler, dimethyl sulfoxide does not inhibit hydrolysis. These findings, together with the observation that electron transport increases the rate of the Pi-ITP exchange reaction, suggest that electrochemical H+ gradients modify the kinetic characteristics of particulate Fi-ATPase. Glycerol and methanol, but not dimethylformamide, induce effects similar to those of dimethyl sulfoxide on oxidative phosphorylation and the Pi-ATP exchange reaction. This suggests that the described effects of solvents could be due to alterations of water structure.

Adenosine Triphosphate↗
PubMed1983

[Interference of extraneous solutes in the iontophoresis of salicylic acid across the skin].

It has been analyzed the possibility to modify the cutaneous ionthophoresis of drugs by means of an original apparatus through which experiments are performed on isolated rat skin. The test drug employed as the salicylic acid (SA). The presence of parasite ions decreases the passage of SA through the skin with an effect which is proportional to the salt concentration. The sodium salicylate is transferred less than SA. It has been analyzed the effect of drugs increasing the skin permeability like dimethylsulfoxide (DMSO) and dimethylformamide (DMF). DMSO in combination with SA facilitates the SA cutaneous ionthophoresis, while DMF does not.

Animals↗
PubMed1981

Inhibition of induced L-ornithine decarboxylase stimulation and erythrodifferentiation in Friend erythroleukemia cells by 2',5'-isoadenylate trimer core.

Friend erythroleukemia cells were induced to differentiate by hexamethylene bisacetamide, dimethyl sulfoxide, and dimethylformamide. The effect of 2',5'-oligoadenosine (trimer core) on cell growth, on erythrodifferentiation, and on the level of L-ornithine decarboxylase was tested. The results indicated a dose response-inhibitory effect of the trimer core on erythrodifferentiation. The optimal dose of the trimer inhibited hexamethylene bisacetamide and dimethyl sulfoxide stimulation of L-ornithine decarboxylase activity, with no apparent effect on cell growth, resembling the effect of high doses of interferon on both erythrodifferentiation and L-ornithine decarboxylase reported previously.

Acetamides↗