SEARCH · PubMed Health

Results for “DIMETHYLFORMAMIDE”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 721 records · Page 40Linked to original sources

PubMed1980

Development of chemotactic responsiveness in myeloid precursor cells: studies with a human leukemia cell line.

We have studied the events that occur during the development of chemotaxis in HL60, a promyelocytic leukemia cell line that acquires the features of mature neutrophils when exposed to dimethylformamide (DMF). Chemotactic function first appears between 48 and 96 hr of DMF induction and is associated not only with the coincidental development of deformability, spontaneous motility, greatly increased binding of fMet-Leu-Phe, and orientation but also with decreasing cell size and pleomorphism of nuclei. Surface adhesiveness develops earlier (36-48 hr) and is coincident with a 10-fold increase in protein synthesis not seen in other DMF-inducible cell lines. This burst of protein synthesis precedes the expression of chemotactic function. These studies show that the HL60 cell line can provide a useful model for delineating control mechanisms responsible for the development of complex cellular functions present in differentiated myeloid cells in humans.

Animals↗

PubMed1996

Reduction in water activity greatly retards the phosphoryl transfer from ATP to enzyme protein in the catalytic cycle of sarcoplasmic reticulum Ca2+-ATPase.

Cys-674 of the sarcoplasmic reticulum Ca2+-ATPase was labeled with N-acetyl-N'-(5-sulfo-1-naphthyl)ethylenediamine without a loss of the catalytic activity. The ATP-induced drop in the fluorescence of the label, which was shown in our previous studies to reflect the conformational change upon formation of the calcium.enzyme.ATP complex, was followed by the stopped-flow method. The subsequent phosphoenzyme formation was followed by the rapid quenching method. Effects of a partial substitution of organic solvents for water in the medium on the conformational change and phosphoenzyme formation were investigated in the presence of 100 microM CaCl2 at pH 7.5, 0 degrees C. The rate of the conformational change increased with increasing ATP concentration (0.1 100 microM) and was unaffected by 30% (v/v) dimethyl sulfoxide. In contrast, the rate of phosphoenzyme formation decreased sharply with increasing concentration of dimethyl sulfoxide (20-40% (v/v)), even when phosphoenzyme formation was saturated with ATP. N,N-Dimethylformamide and glycerol had essentially the same effects as dimethyl sulfoxide. These results show that the reduction in water activity does not affect the rate of the conformational change upon formation of the calcium.enzyme.ATP complex, but greatly retards the subsequent phosphoryl transfer from ATP to the enzyme protein. This strongly suggests that in this early stage of the catalytic cycle water plays a critical role in ensuring the rapid turnover of the enzyme.

Adenosine Triphosphate↗

PubMed1995

Selective toxicity of compounds naturally present in food toward the transformed phenotype of human colorectal cell line HT29.

It has previously been observed that allyl isothiocyanate, a compound naturally present in the diet, is more cytotoxic toward the human colorectal adenocarcinoma cell line HT29 in its control transformed state than after exposure to sodium butyrate or to dimethylformamide, which slow growth and induce differentiation (detransformation). In the present study, a range of other dietary compounds were assayed for such selective toxicity. These compounds were chosen as constituents of foodstuffs that have been identified from epidemiologic studies as being potentially antitumorigenic and also as having anticarcinogenic activity in experimental models. Benzyl and phenethyl isothiocyanate, benzyl thiocyanate, and quercetin showed decreased toxicity towards HT29 after detransformation of the cells by one or both treatments, whereas no change was observed in the sensitivity to diallyl sulfide or diallyl disulfide. It is proposed that the presence of such selectively toxic compounds in the diet may inhibit the development of tumors by interfering with the growth of preneoplastic lesions while having little effect on normal cells. The cumulative effects of these inhibitions may contribute to the chemopreventive properties of the parent foodstuffs observed in epidemiologic studies.

Adenocarcinoma↗

PubMed2006

Bacterial community changes with N'-N' dimethylforamide (DMF) additives during polycyclic aromatic hydrocarbons (PAH) biodegardation.

This study examined the changes in the bacterial community during biodegradation of polycyclic aromatic hydrocarbon (PAH) substrate when N'-N' dimethylformamide (DMF) was added. The microbial populations that biodegrade the PAH substrate were assessed by Fluorescence in-situ hybridization (FISH) and changed from 49.45% Archaea and 49.15% Bacteria to 42.00% Archaea and 51.78% Bacteria when the PAH was supplemented with DMF. Nine microorganisms were classified as Gram-negative alpha-, beta- and gamma-Proteobacteria bacteria during biodegradation of PAH alone by the Biolog system. Incentive eleven microorganisms obtained from the PAH-DMF mixed substrate were found to be beta-, gamma-Proteobacteria bacteria, high G+C Gram-positive bacteria (HGC), low G+C Gram-positive bacteria (LGC) and there was even one Deinococcus-Thermus strain; this indicates greater biodiversity. The numbers in the Pseudomonad group were as high as 10(5)-10(6) CFU ml(-1), suggesting that this group plays an important role in PAH biodegradation. Community-Level Physiological Profiling (CLPP) and physiological characterization were different in the PAH biodegradation process with and without DMF. Utilization of the 95 carbon sources from the Biolog GN2 microtiter plate was greater during PAH biodegradation when PAH is present alone compared to that in the presence of DMF. The range of enzymatic activities during PAH biodegradation was lower in the presence of DMF. These results show that DMF should be used with caution when PAH is a substrate during laboratory or pilot biotreatability studies.

Archaea↗

PubMed1983

Seasonal effects on concentrations of monomethylformamide in urine samples.

Eleven du Pont operators participated in a special dimethylformamide metabolite (monomethylformamide, MMF) urine monitoring study to investigate a possible seasonal influence on urine metabolite concentrations. Variables considered included urine volume, MMF concentration, MMF mass, urine specific gravity, and ambient temperature. Statistical analysis revealed a 13% reduction in urine volume under hot weather conditions as a cause of increased MMF concentrations. A correction for this change in urine volume should be made subjectively.

Dimethylformamide↗

PubMed1997

Activation of the HIV type 1 long terminal repeat and viral replication by dimethylsulfoxide and related solvents.

The HIV-1 long terminal repeat (LTR) introduced into the macrophage cell line THP-1 and the T lymphocyte cell line Jurkat in association with the luciferase reporter gene is activated by the polar, aprotic solvents dimethylsulfoxide (DMSO), dimethylacetamide (DMAC), and dimethylformamide (DMF). These solvents also greatly potentiated the activation of the LTR in THP-1 cells by phorbol myristate acetate (PMA), tumor necrosis factor alpha (TNF-alpha), H202, and a Staphylococcus epidermidis product. Lipopolysaccharide (LPS) and lipoteichoic acid (LTA) at 1 microg/ml had no effect on the LTR in THP-1 cells unless the solvents were added. The aprotic solvents also greatly potentiated the activation of the LTR in Jurkat cells by PMA, TNF-alpha, and H202, whereas LPS, LTA, or the S. epidermidis product had no effect in the presence or absence of the solvents. DMSO, DMAC, and DMF also increased the production of intact virions by latently HIV-1-infected ACH-2, J1.1, U1, and OM10.1 cells under some experimental conditions. The use of the polar aprotic solvents DMSO, DMAC, and DMF, by amplification, may allow the better detection of a weak activator of the LTR and facilitate studies of the mechanism of activation.

Acetamides↗

PubMed2006

Biomimicking extracellular matrix: cell adhesive RGD peptide modified electrospun poly(D,L-lactic-co-glycolic acid) nanofiber mesh.

A cell adhesive peptide, Arg-Gly-Asp (RGD), was immobilized onto the surface of electrospun poly(D,L-lactic-co-glycolic acid) PLGA nanofiber mesh in an attempt to mimic an extracellular matrix structure. A blend mixture of PLGA and PLGA-b-PEG-NH(2) di-block copolymer dissolved in a 1:1 volume mixture of dimethylformamide and tetrahydrofuran was electrospun to produce a nanofiber mesh with functional primary amino groups on the surface. Various electrospinning parameters, such as polymer concentration and the blend ratio, were optimized to produce a nanofiber mesh with desirable morphology, surface characteristics, and fiber diameter. A cell adhesive peptide, GRGDY, was covalently grafted onto the aminated surface of the electrospun mesh under a hydrating condition. The amounts of surface primary amino groups and grafted RGD peptides were quantitatively determined. Cell attachment, spreading, and proliferation were greatly enhanced in the RGD modified electrospun PLGA nanofiber mesh compared with that of the unmodified one.

Animals↗

PubMed1987

'Water structure' versus 'radical scavenger' theories as explanations for the suppressive effects of DMSO and related compounds on radiation-induced transformation in vitro.

We report here that dimethylsulfoxide (DMSO): suppresses radiation-induced transformation in vitro, even when DMSO treatments begin as late as 10 days post-irradiation (when cells are in the confluent, stationary phase of growth); inhibits the 12-O-tetradecanoylphorbol-13-acetate (TPA) enhancement of radiation-induced transformation in vitro; does not affect the expression of transformed cells as foci (when surrounded by non-transformed cells); and may be affecting radiation-induced transformation through its solvent properties (i.e. the 'Water Structure' theory), while its effects on the TPA enhancement of radiation transformation may be mediated by its free radical scavenging abilities. DMSO, dimethylformamide (DMF) and dimethylacetamide (DMA) are similar solvents which are all very effective in their ability to suppress radiation-induced transformation in vitro (at concentrations in the cellular media down to 0.01%). As DMSO is known to be an extremely effective OH. free-radical scavenging agent, while DMF and DMA are not as efficient at scavenging free radicals, our results suggest that properties other than free-radical scavenging ability may be important in the suppressive effects of these compounds on radiation-induced transformation in vitro. It is known that low concentrations of such basic aprotic solvents modify water structure so as to suppress the protic (H-bond donor) reactivity of water and enhance its basic (H-bond receptor) reactivity. These reactivity changes may well be responsible for the effects noted above. DMSO, DMF and DMA are also capable of suppressing the TPA enhancement of radiation transformation (at concentrations of the compounds of 0.1% or higher). For this effect, the ability of these compounds to scavenge OH. shows a general correlation with their ability to suppress the TPA enhancement of transformation, suggesting that the 'Radical Scavenger' theory may explain the ability of DMSO to suppress promotion in vitro.

Acetamides↗

PubMed1990

Detection and quantitation of ethylene oxide, 2-chloroethanol, and ethylene glycol with capillary gas chromatography.

A procedure is described for detection and quantitation of ethylene oxide and two major reaction products. Detection of ethylene oxide residuals extracted from alcohol pads (cellulose) and plastic material is illustrated. Quantitation of the three compounds can be obtained with a single gas chromatographic (GC) analysis. A DB-Wax-30N, 0.25 mm i.d. column is used with 1:50 split injections with dimethylformamide as the solvent and 1:100 split injections with water as the solvent. A DB-Wax-30W, 0.32 mm i.d. column is used for on-column injections and 1:100 split water injections. Linearity of the three compounds is demonstrated.

Chromatography, Gas↗

PubMed1986

Organic solvents inhibit the mutagenicity of promutagens dimethylnitrosamine and methylbutylnitrosamine in a higher plant Arabidopsis thaliana.

The organic solvents dimethylsulphoxide (DMSO), acetone, ethanol and dimethylformamide inhibited the mutagenic activity of the promutagens dimethylnitrosamine and methylbutylnitrosamine in a higher plant Arabidopsis thaliana. In contrast, the direct-acting mutagens N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and N-methyl-N-nitrosourea (MNU) were not affected by the organic solvents (with the exception of DMSO). The effect of DMSO on MNNG- and MNU-mutagenesis is explained by its effect on the pH of the mutagenic solution. The results support the assumption that the activation of promutagenic nitrosamines in A. thaliana proceeds by the same, or similar, mechanisms to that in 'animal' activation.

Acetone↗

PubMed1998

Optimization of excimer-forming two-probe nucleic acid hybridization method with pyrene as a fluorophore.

A previously presented homogeneous assay method, named the excimer-forming two-probe nucleic acid hybridization (ETPH) method, is based on specific excimer formation between two pyrenes attached at the neighboring terminals of two sequential probe oligonucleotides complementary to a single target. In this study, we investigated assay conditions and optimal molecular design of probes for intense excimer emission using a pyrenemethyliodoacetamide-introduced 16mer probe, a pyrene butanoic acid-introduced 16merprobe and a target 32mer. The length of the linker between the pyrene residue and the terminal sugar moiety remarkably influenced the quantum efficiency of excimer emission; the pair of linker arms of these two probes was optimal. The quantum efficiency was also dependent upon the concentrations of dimethylformamide and NaCl added to the assay solution. Spectroscopic measurements and T m analysis showed that an optimal configuration of the two pyrene residues for intense excimer emission might be affected by pyrene-pyrene interaction, pyrene-duplex interaction (intercalation/stacking) and solvent conditions as a whole. We then demonstrated the practicality of the ETPH method with the optimal hybridization conditions thus attained by determining that the concentration of 16S rRNA in extracts from Vibrio mimicus ATCC 33655 cells in exponential growth phase is 18 500 16S rRNA molecules/cell on average.

Absorption↗

PubMed2002

Physicochemical analysis of nucleobase-metal interactions.

It is important to know what kinds of chemical bonds are formed between metal ions and nucleic acids. We have studied metal-nucleobase interactions, by using NMR spectroscopy in solution. For the accurate understanding, we tried measurement at low temperature below -30 degrees C. To avoid freezing of the solution, we have extensively searched solution conditions which is suitable for measurements at low temperature, and found several possible conditions. One was the condition which contained H2O and cryoprotectant at low pH for guanosine-5'-monophosphate--Cd(II), system, the other was the mixed solvent of dimethyl sulfoxide and N,N-dimethylformamide for guanosine--Cd(II) system.

Cold Temperature↗

PubMed2005

Characterization of chemically induced hepatotoxicity in collagen sandwiches of rat hepatocytes.

It has been shown that hepatocytes cultured in a collagen sandwich configuration maintain cell viability, morphology, and drug metabolizing activities for several weeks. The purpose of this study was to characterize chemically induced general toxicity in this system by exposing hepatocytes to eight different hepatotoxic compounds. Cell function and viability was measured by analyzing the secretions of urea and albumin and the release of lactate dehydrogenase. Significant decreases in urea and albumin secretions were detected after treatments with 32 nM aflatoxin B(1) and 1 mM doses of cadmium and the alkylating agents N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and methyl methane sulfonate (MMS). However, no significant toxicity could be measured following exposures to 5 mM carbon tetrachloride, 1 mM N, N-dimethylformamide (DMF), 1 mM vinyl acetate, and 1 mM acetaminophen. Western blots of cell lysates showed that hepatocytes maintained CYP1A, 2B, 3A2 but gradually lost CYP2E1, which is the main metabolic enzyme for acetaminophen, carbon tetrachloride, and DMF. The metabolites of acetaminophen were identified using liquid chromatography and electrospray mass spectrometry. It was determined that the hepatocytes converted most of the acetaminophen to the glucuronide and sulfate metabolites and only formed a small amount of the glutathione adduct. This research shows that the collagen sandwich culture system can only be used selectively for detecting hepatotoxicity and for identifying major metabolites of xenobiotic compounds.

Acetaminophen↗

PubMed2006

A single oral dose of ethanol can alter transdermal absorption of topically applied chemicals in rats.

Topical ethanol is used as a dermal penetration enhancer in some commercial products. Previous studies have demonstrated that chronic ethanol consumption can also disrupt skin barrier function, leading to increased transdermal penetration. This observation becomes much more relevant if a single drinking episode induces similar changes. The purpose of this study was thus to examine the transdermal penetration of three model chemicals after acute ethanol consumption. Wistar rats were gavaged with either 10, 6, 4.3, 3, 1.5 g/kg ethanol or saline and allowed to recover for 2 or 24 h. Blood and skin ethanol levels were determined and in vitro penetration experiments performed. The herbicide paraquat, industrial solvent N,N-dimethylformamide (DMF), and insect repellent N,N-diethyl-m-toluamide (DEET) were used as is model chemicals. Absorption was determined and directly compared between ethanol- and saline-treated skin by calculating enhancement ratios. Blood ethanol levels range from 0.25 to 0.015% at 2 h with skin levels at 12-18% of blood values. Ethanol enhances the absorption of paraquat, DMF, and DEET in a dose-dependent fashion. Paraquat and DEET showed no appreciable reduction in enhancement between 2 and 24 h postgavage for the 10-g/kg dose, but DMF did. Enhancement ratios were higher at 24 h for 10 than for 6 g/kg animals, demonstrating a dose-response relationship for recovery time. These studies imply that increased absorption of topical chemical occurs after alcohol ingestion. Both acute and chronic ethanol consumption can compromise the dermal barrier.

Administration, Cutaneous↗

PubMed1990

Fulminant hepatic failure in poisoning due to ingestion of T 61, a veterinary euthanasia drug.

A patient developed fulminant hepatic failure 48 h after the ingestion of T 61, a veterinary euthanasia drug which contains both general and local anesthetics, a neuromuscular blocking agent, and dimethylformamide (DMF) as a solvent. This is the first report of such severe hepatic manifestation in T 61 poisoning, the most common symptoms of which are early coma and respiratory failure due to the anesthetic and the neuromuscular blocking agent. In a very few cases mild and transitory symptoms of hepatic insufficiency have been observed. In this case the fulminant hepatic failure was due to the high dose (0.6 ml/kg) ingestion of DMF.

Amides↗

PubMed1999

Breaking the low barrier hydrogen bond in a serine protease.

The serine protease subtilisin BPN' is a useful catalyst for peptide synthesis when dissolved in high concentrations of a water-miscible organic co-solvent such as N,N-dimethylformamide (DMF). However, in 50% DMF, the k(cat) for amide hydrolysis is two orders of magnitude lower than in aqueous solution. Surprisingly, the k(cat) for ester hydrolysis is unchanged in 50% DMF. To explain this alteration in activity, the structure of subtilisin 8397+1 was determined in 20, 35, and 50% (v/v) DMF to 1.8 A resolution. In 50% DMF, the imidazole ring of His64, the central residue of the catalytic triad, has rotated approximately 180 degrees around the Cbeta-Cgamma bond. Two new water molecules in the active site stabilize the rotated conformation. This rotation places His64 in an unfavorable geometry to interact with the other members of the catalytic triad, Ser221 and Asp32. NMR experiments confirm that the characteristic resonance due to the low barrier hydrogen bond between the His64 and Asp32 is absent in 50% DMF. These experiments provide a clear structural basis for the change in activity of serine proteases in organic co-solvents.

Crystallography, X-Ray↗

PubMed1984

Optimization of bioavailability of topical steroids: penetration enhancers under occlusion.

The occluded vasoconstrictor assay was used to assess the effect of penetration enhancers on the topical bioavailability of a representative steroid, betamethasone 17-benzoate, with dimethylisosorbide (DMI) as a reference solvent. In the initial test, only N-methyl-2-pyrrolidone (NMP) increased the steroid bioavailability; acetone, dimethylformamide (DMF), 2-pyrrolidone (2-P), and 1-ethyl-2-pyrrolidone (EP) were equal to DMI, while propylene glycol (PG) and N,N-diethyl-m-toluamide (DEET) were poorer. Reocclusion showed that NMP and acetone established superior stratum corneum reservoirs; DMF, 2-P, EP, and PG were as effective as DMI but DEET was less effective. It was concluded that occlusive hydration and lack of thermodynamic control may have obscured the enhancing abilities of the solvents, 2-P, NMP, EP, DMF, and DEET induced erythema in some volunteers, although this was usually short-lived.

Acetone↗

PubMed1980

Mechanism of racemisation of histidine derivatives in peptide synthesis.

Evidence is presented to show that the racemisation of N(alpha)-benzyloxycarbonyl-N(pi)-phenacyl-L-histidine which occurs on activation with dicyclohexylcarbodiimide in dimethylformamide takes place by action of the pi-nitrogen as an intramolecular base catalyst in the O-acylisourea adduct which is in reversible equilibrium with the reactants, rather than by formation of an optically labile heterocyclic intermediate.

Chemical Phenomena↗