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At least 19 recordsLinked to original sources
PubMed1990

[Genotoxicity of synthetic dyes in umu test using Salmonella typhimurium TA1535/pSK1002 (1). Results of examination for acid dyes, direct dyes, disperse dyes and reactive dyes].

The umu test system is a newly developed method to evaluate genotoxicities of a wide variety of environmental carcinogens and mutagens (Oda et al., 1985; Nakamura et al., 1987). In the present study, SOS-inducing activity of 142 synthetic dyes was investigated by the umu test using Salmonella typhimurium (TA1535/pSK1002) under the condition of absence and presence of rat liver microsomal fraction. The samples showing a beta-galactosidase activity of more than 1.5 fold over the background level were reexamined and the dose-response curves were prepared at various doses. Then, the samples showing beta-galactosidase activity of more than 1.5-fold of the background level were defined as genotoxic. Among the synthetic dyes examined, 11 compounds induced umu gene expression. The potent genotoxic compounds without metabolic activation were Acid Black 26, Acid Black 50, Acid Brown 2, Disperse Red 73, Disperse Red 145, Disperse Red 157, Disperse Violet 52, Reactive Red 110, Reactive Yellow 13 and Reactive Yellow 75, and in the presence of S9, Reactive Blue 147 was judged to be genotoxic. An evident dose-response relationship was observed between the doses of the dye and umu-gene expression in these 11 dyes.

Coloring Agents↗
PubMed1995

Dye laser treatment of port-wine stains: comparison of the continuous-wave dye laser with a robotized scanning device and the pulsed dye laser.

BACKGROUND: Despite good results in the treatment of most port-wine stains (PWS) with continuous-wave visible-light lasers, light PWS and those in certain locations respond less favorably and have a higher risk of scarring. Robotized scanning devices such as the Hexascan device have been developed for continuous-wave laser sources to produce greater target specificity, to increase reproducibility of results, and to decrease the incidence of adverse effects. OBJECTIVE: The purpose of this study was to compare the effects of the same wavelength of light (585 nm) on test sites within PWS with the flashlamp-pumped pulsed dye laser and a continuous-wave tunable dye laser scanned through a Hexascan robotized scanning device. METHODS: Two adjacent, noncontiguous sites within PWS were treated in 29 patients, one site with the flashlamp-pumped pulsed dye laser and the other with an argon-pumped continuous-wave tunable dye laser affixed to a Hexascan device. RESULTS: Twenty-eight patients completed the study. The pulsed dye laser was found to be superior to the continuous-wave dye laser with the Hexascan device in 45% of patients, whereas the continuous-wave tunable dye laser with the Hexascan device was considered superior in 15%. There was no difference in the remaining 40%. Undesirable side effects were infrequent with both treatments. There was no significant difference in hypopigmentation or atrophic and hypertrophic scarring, but hyperpigmentation was more frequent with the continuous-wave dye laser with the Hexascan device. CONCLUSION: Both the pulsed dye laser and continuous tunable-wave dye laser with the Hexascan device produce slight lightening after one treatment. The pulsed dye laser produces slightly greater lightening than the continuous-wave tunable dye laser with the Hexascan device 6 weeks after treatment of test areas within PWS in 40% of those treated. It also produced slightly less hypopigmentation and hyperpigmentation.

Adolescent↗
PubMed1997

Kinetics and Mechanism of Dyeing Processes: The Dyeing of Cotton Fabrics with a Procion Blue Dichlorotriazinyl Reactive Dye

The kinetics of the dyeing of a dichlorotriazinyl-reactive dye, Procion Blue MX-R, with knitted cotton fabrics have been studied using a versatile technique based on a spectrochemical channel flow cell. A mechanism is derived where the simultaneous hydrolysis of the dye molecules, the physical binding of the hydrolyzed form, and the chemical fixation of the active form onto the fabric are taken into account. It is shown that the dye fixation to the fabric is controlled by a solid-liquid interfacial process that is first order with respect to the surface concentration of dye; however, the rate of this reaction is governed by the availability of sites for the adsorption of dye molecules on the fabric surface. Dyeing experiments are performed over a wide range of initial dye concentrations; supporting electrolyte concentrations and the kinetic parameters are reported. Atomic force microscopic studies indicate that mercerization pretreatment provides a disordered fiber surface which may offer additional sites for dye adsorption.

Journal Article↗
PubMed2001

Interaction of cyanine dyes with nucleic acids. XXV. Influence of affinity-modifying groups in the structure of benzothiazol-4-[2,6-dimethylpyridinium] dyes on the spectral properties of the dyes in the presence of nucleic acids.

Novel monomethine pyridinium cyanine dyes of similar structure and containing 'affinity-modifying' groups of different chemical nature were studied by spectral-luminescent methods as possible fluorescent probes for the nucleic acids detection. It was shown that the nature of the functional groups in the dye linker influences the fluorescent properties of the dye-nucleic acids complexes. Incorporation of a hydroxyl group into the linker structure leads to a significant increase in the fluorescence intensity of the dye--double-stranded DNA complexes relative to the parent dye Cyan 40.

DNA↗
PubMed2002

Studies on desorption of individual textile dyes and a synthetic dye effluent from dye-adsorbed agricultural residues using solvents.

Two solvents, A and B (A: methanol, chloroform, water in the ratio 1:1:1; B: 50% methanol), were used to extract textile dyes adsorbed onto substrates for the purpose of future analyses of the amount of dyes degraded through solid state fermentation (SSF) using white rot fungi. Barley husk, apple pommace and corncob were separately soaked in five different dye solutions and a synthetic textile effluent. A maximum value of 93% desorption of Cibacron Red from corncob was achieved using solvent A. Barley husk was the only substrate from which the synthetic textile effluent could be desorbed, with 82% being recovered using solvent A.

Adsorption↗
PubMed1993

An improved method for studying microvascular geometry using fluorescent dyes: preventing dye extravasation, preserving dye integrity and enhancing tissue morphometry.

A procedure for stabilizing fluorescent markers used to study the microvascular geometry and morphometry of muscle tissue is described. The procedure involves fluorescent labeling of plasma, fixation of muscle tissue in 10% buffered formalin, and quick freezing. This procedure prevents extravasation of the fluorescent dyes out of the capillaries as frequently seen in other muscle microvascular techniques, thereby greatly increasing the time that capillaries are visible. We found that formalin may actually increase the rate of fluorochrome bleaching by photo-oxidation, but the increased rate of bleaching is more than offset by the greater concentration of dye trapped in the capillaries. Further, formalin fixation results in little distortion of the muscle fibers themselves, making this approach ideal for morphometric studies.

Animals↗
PubMed1992

DNA sequencing with dye-labeled terminators and T7 DNA polymerase: effect of dyes and dNTPs on incorporation of dye-terminators and probability analysis of termination fragments.

The incorporation of fluorescently labeled dideoxynucleotides by T7 DNA polymerase is optimized by the use of Mn2+, fluorescein analogs and four 2'-deoxyribonucleoside 5'-O-(1-thiotriphosphates) (dNTP alpha S's). The one-tube extension protocol was tested on single-stranded templates, as well as PCR fragments which were made single-stranded by digestion with T7 gene 6 exonuclease. Dye primer sequencing using four dNTP alpha S's was shown to give uniform termination patterns which were comparable to four dNTPs. Efficiency of the polymerase also appeared to improve with the dNTP alpha S's. A mathematical model was developed to predict the pattern of termination based on enzyme activity and ratios of ddNTP/dNTPs. This method can be used to optimize sequencing reactions and to estimate enzyme discrimination constants of chain terminators.

Base Sequence↗
PubMed1985

Interaction of Cibacron Blue F3GA with glutamine synthetase: use of the dye as a conformational probe. 1. Studies using unfractionated dye samples.

Cibacron Blue F3GA dye has been used to probe subtle conformational changes in protein structure associated with the conversion of Escherichia coli glutamine synthetase (GS) between relaxed, taut, oxidized, and dissociated forms. Binding of the dye to each form of the enzyme elicits a different spectral perturbation of the dye which can be detected by difference spectroscopy. By following time-dependent changes in the difference spectrum associated with the binding of dye to the enzyme, it was demonstrated that dissociation of subunits provoked either by urea or by relaxation of the enzyme at pH 8.5 is a multiphasic process. In the presence of 3-4 M urea, dissociation of taut GS is associated with an almost instantaneous, transient increase in absorbancy of the difference spectrum at 638 nm and, after a lag, by a progressive decrease in absorbancy at 585 nm and an increase at 700 nm. The kinetics of these changes vary as a function of temperature, pH, and the concentrations of KCl, MnCl2, and urea, probably reflecting differences in the rates of GS relaxation and in the formation of aggregates of intermediate sizes. Results of direct binding measurements show that the taut and relaxed forms of GS can bind only 1-1.3 equiv of dye per subunit, whereas dissociated subunits bind up to 3.0 equiv per subunit. The Kd of the dye-taut GS complex as calculated from binding data was 0.55 microM. The binding of dye to taut GS was inhibited by its substrate, ADP, and by the allosteric effectors AMP and tryptophan. On the basis of the abilities of ADP, AMP, and tryptophan to inhibit the binding of dye to GS, dissociation constants of the respective GS-ligand complexes were 2.4, 121, and 1170 microM, respectively, in good agreement with previously determined values. From the difference spectra obtained between a given concentration of dye in a 5.0-cm cell and 10 times that concentration in a 0.5-cm cell, it was established that at concentrations greater than 5 microM a significant fraction of the dye is present as stacked aggregates. Because only the dye monomer binds to GS, the difference spectrum between dye and dye bound to GS is due in part to GS-promoted shifts in the equilibrium between stacked and unstacked dye molecules. Consequently, with increasing dye concentrations, the amplitude of the dye vs. dye + GS difference spectrum can continue to increase, even after the GS becomes saturated with dye.(ABSTRACT TRUNCATED AT 400 WORDS)

Adenine Nucleotides↗
PubMed1993

Mechanism of connective tissue techniques. I. The effect of dye concentration and staining time on anionic dye procedures.

Anionic dye connective tissue procedures were performed by staining for 5 min and 24 h with (a) 0.00018 M and 0.0018 M solutions of 28 dyes, and 0.018 M solutions of 21 dyes in saturated picric acid (SPA), and (b) 0.0018 M and 0.018 M solutions of 20 dyes in 1% (w/v) phosphomolybdic acid (PMA). The staining obtained with dyes in SPA was classified as selective (no cytoplasmic staining), moderately selective (traces of cytoplasmic staining) and non-selective (all other staining patterns). The staining of collagen and cytoplasm with dyes in PMA was separately classified on a scale of 1-5 (1 = no staining, 5 = maximum staining). The selectivity of the staining obtained with SPA with solutions of dyes at concentrations of 0.00018 M and 0.0018 M, and both staining times, was correlated (p < 0.001) with an empirical sulphonic acid constant (SAC) defined as the (number of dye sulphonic acid groups/dye molecular weight) x 10(3). Correlation with molecular weight was poor and was significant only when staining was performed with 0.00018 M dye solutions for 24 h. The dyes were divisible into three groups: group 1 (selectivity independent, or almost independent of staining time), group 2 (selective to moderately selective when staining was performed for 5 min), and group 3 (non-selective). The SAC of the group 1 dyes differed significantly from those of the group 2 and 3 dyes. Selectivity was essentially lost at dye concentrations of 0.018 M. The staining with acidic dyes (no amines or substituted amines) in PMA differed significantly (p < 0.001) from that obtained with amphoteric dyes (containing basic substituents).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

Dye sensitivity correlated with envelope protein changes in dye (sfrA) mutants of Escherichia coli K12 defective in the expression of the sex factor F.

Mutations of the dye gene on the E. coli chromosome result in sensitivity to the dye toluidine blue and, in male cells, cause loss of F pili, producing sterility in conjugation. Compared with its dye+ parent, a strain deleted for dye (delta dye) showed an altered sensitivity to a wide range of dyes and antibiotics which affect different intracellular processes, and hence it appeared likely that the barrier properties of the cell envelope were impaired. Unlike mutants known to be defective in LPS structure, there appeared to be no correlation between the hydrophobicity of the compounds and the sensitivity of the delta dye strain. Moreover there was no difference between dye+ and delta dye strains in their sensitivity to LPS-specific phages, and chemical and GLC analysis of LPS components revealed no difference between the two strains. Examination of outer and inner membrane proteins from isogenic strains having the delta dye deletion and the dye+ gene cloned into the plasmid pACYC184, with or without insertional inactivation of dye by the transposon gamma delta, was performed by SDS-PAGE. This revealed a number of differences in the profile of proteins from both inner and outer membranes, correlated with mutation in the dye gene. The dye gene appears to be identical to the sfrA gene, which has been shown to be required for efficient transcription of the sex factor F. It is therefore proposed that the dye (sfrA) gene product may also control the expression of chromosomal genes coding for envelope proteins.

Anti-Bacterial Agents↗
PubMed1995

Fluorescent styryl dyes as probes for Na,K-ATPase reaction mechanism: significance of the charge of the hydrophilic moiety of RH dyes.

The fluorescence responses of a series of potential-sensitive styryl-based dyes (either zwitterionic RH160, RH421, di-4-ANEPPS, or positively charged RH795, RH414, RH461) to phosphorylation of Na,K-ATPase from ATP or inorganic phosphate, and ouabain binding to phospho- or dephosphoforms, have been characterized and compared in broken membrane preparations of the enzyme. Zwitterionic dyes were more sensitive to molecular events in the Na,K-ATPase reaction cycle than positively charged dyes, but the net charge did not affect the sensitivity of the dyes to a transmembrane electric field. The major part of the response of the zwitterionic dyes to formation of phosphoenzymes was due to a change in the quantum yield of fluorescence. Computer modeling of dyes with identical chromophore structure, and experimental characterization of their optical properties in bulk solvents, revealed two general trends: (1) the absorption maximum of the zwitterionic dye was blue-shifted with respect to the positively charged dye; (2) the quantum yield of the zwitterionic dye was higher and the fluorescence lifetime was longer than that for the positively charged dye. Spectral properties of the dyes in the membrane depended on the presence of Na,K-ATPase. We suggest, that (1) electrostatic interactions between the enzyme and the hydrophilic headgroup of the dye by changing the charge of hydrophilic moiety and thus modifying the net charge of the dye molecule cause both the spectral shifts and the changes in the quantum yield, and (2) interactions between the styryl dyes and the Na,K-ATPase depend on the conformational state of the enzyme.

Animals↗
PubMed1999

Carbon dye as an adjunct to isosulfan blue dye for sentinel lymph node dissection.

BACKGROUND: The success of intraoperative lymphatic mapping depends on accurate identification of the sentinel node. We hypothesized that a carbon particle suspension would allow histopathologic confirmation of the sentinel lymph node through deposition of carbon within that node. METHODS: An animal model was used to compare the lymphatic mapping accuracy of carbon dye with that of isosulfan blue dye, the standard agent for intraoperative visualization of the sentinel lymph node. Twenty-two rats underwent lymphatic mapping in each distal lower extremity with various combinations of carbon dye and isosulfan blue dye. All stained (blue or black) nodes in the inguinal drainage basin were removed for pathologic analysis, including carbon particle analysis. A meticulous search identified all nonstained (nonsentinel) nodes in the same basin. These nonsentinel nodes were examined for carbon particles by light microscopy. Dermal diffusion of mapping agents at the injection site was also recorded. Animals were then observed for 28 days to assess the toxicity of mapping agents. RESULTS: Although isosulfan blue dye and full-strength carbon dye each stained all sentinel nodes, the latter obscured histologic detail. The combination of 2.5% carbon dye, 7.5% saline solution, and 90% isosulfan blue dye also stained all sentinel nodes; carbon particles were seen on light microscopy in all 13 stained nodes and did not interfere with histologic evaluation. No unstained node contained carbon particles, although the number of nonsentinel nodes was small. Carbon dye exhibited significantly less intradermal diffusion than isosulfan blue dye, but the carbon left a permanent mark on the skin. No toxicity or side effect associated with the use of carbon dye was observed. CONCLUSION: Carbon dye allows histopathologic confirmation of sentinel lymph nodes identified by isosulfan blue dye.

Animals↗
PubMed1980

Interactions of voltage-sensing dyes with membranes. II. Spectrophotometric and electrical correlates of cyanine-dye adsorption to membranes.

The adsorption to bilayer membranes of the thiadicarbocyanine dyes, diSCn(5), has been studied as a function of the membrane's surface-charge density, the aqueous ionic strength, and the length (n) of the hydrocarbon side chain of the dye. "Probe" measurements in planar bilayers, microelectrophoresis of liposomes, and measurement of changes in dye absorbance and fluorescence in liposomes were used to study dye adsorption to membranes. These measurements indicated that the membrane:water partition coefficient for the dye monomer increases with the length of the hydrocarbon side chain. However, the formation of large aggregates in the aqueous phase also increases with increasing chain length and ionic strength so that the actual dye adsorbing to the membrane goes through a maximum at high but not at low ionic strengths. More dye adsorbs to negatively charged than neutral membranes. Membrane-bound dye spectra were easily resolved in negatively charged liposomes where it was observed that these dyes could exist as monomers, dimers, and large aggregates. For diSC1(5) a spectral peak was observed at low but not high ionic strengths (i.e. the conditions in which this dye appears to form voltage-gated channels) corresponding to small aggregates which appeared to adsorb to the membrane. Finally, the adsorption of these dyes to membranes results in more positive electrostatic potentials composed primarily of dye-induced "boundary" potentials and somewhat less of "double-layer" potentials.

Carbocyanines↗
PubMed2000

Interaction of cyanine dyes with nucleic acids. XVII. Towards an aggregation of cyanine dyes in solutions as a factor facilitating nucleic acid detection.

Spectral properties of newly synthesized cyanine dyes, namely 1-[6-(4-[6-[2,6-dimethyl-4-(3-methyl-2,3-dihydro-1,3-benzothiazol- 2-ylidenmethyl)-1-pyridiniumyl]hexanoyl]piperazino)-6- oxohexyl]-2,6-dimethyl-4-(3-ethyl-2,3-dihydro-1,3-benzothiazol+ ++-2-ylidenmethyl)pyridinium (K-6) (bichromophoric dye) and 1-[5-di(3-[5-[2,6-dimethyl-4-(3-methyl-2,3-dihydro-1,3-benzothiazol++ +-2-ylidenmethyl)-1-pyridiniumyl]pentylcarboxamido]pro pyl) carbamoylpentyl]-2,6-dimethyl-4-(3-methyl-2,3-dihydro-1,3-benzo thiazol-2-ylidenmethyl) pyridinium (K-T) (trichromophoric dye) in solutions in the presence of and without deoxyribonucleic acid (DNA) were studied within a wide concentration range. It has been established that absorption, as well as fluorescence of investigated dye solutions, without DNA are mainly determined by H-aggregates of dye molecules. On the contrary, the fluorescence of dye solutions in the presence of DNA gives an intrinsic dye molecular fluorescence. H-aggregates are broken because of binding dye molecules with DNA. It has been suggested that both K-T and K-6 molecules bind mainly with DNA via the interaction of two chromophores. As the ratio of the number of dye molecules to that of DNA base pairs increases with an increase in dye concentration, a formation of dye molecule H-aggregates on DNA molecules are observed. Such aggregates have a different structure than those formed in the solutions without DNA. On the grounds of the data obtained, it is concluded that it is possible to use a dye aggregation capable of obtaining higher values for fluorescence enhancement of the DNA stains.

Benzothiazoles↗
PubMed1998

Effect of Tannic Acid on the zeta Potential, Sorption, and Surface Free Energy in the Process of Dyeing of Leacril with a Cationic Dye.

The behavior of the surface free energy in the process of dyeing Leacril pretreated with tannic acid and subsequently dyeing with the cationic dye Rhodamine B has been studied. Also the electrokinetic behavior of these systems has been analyzed by studying the zeta potential, which has been obtained by means of the streaming potential technique. Values more significative of the zeta potential of these systems have been obtained using the three models of capillaries existing in the literature. The qualitative behavior of the zeta potential is the same for the three models of capillaries tested in this paper. These models are those of Goring and Mason, Biefer and Mason, and Chang and Robertson. The zeta potential of the systems analyzed is negative in the range of concentration of the dye in the liquid phase from 10(-6) to ca. 10(-4) M of dye. In the range of low concentrations (from 10(-6) to ca. 10(-5) M of dye) the zeta potential of the system untreated Leacril/Rhodamine B increases in absolute value due to increasing hydrophobic attractions between both the hydrophobic chains of the dye and the Leacril fibers in aqueous media. In the system Leacril treated with tannic acid/Rhodamine B, this increase is also due to the presence of hydrogen bonding between the phenolic hydroxyl groups of the tannic acid and the sulfonate and sulfate end groups of Leacril fibers. For concentrations of dye between 10(-5) and 10(-4) M of dye in solution, the zeta potential decreases in absolute value due to the electrostatic attractions between the groups negatively charged in the fiber and the cation of the dye. The zeta potential changes its sign at the highest concentrations of dye used in this work. The adsorption of Rhodamine B onto both untreated Leacril and Leacril treated with tannic acid is favored by the increasing temperature of adsorption. The behavior of the components of the surface free energy obtained by the thin-layer wicking technique led us to consider that the cationic dye Rhodamine B is adsorbed on the surface of both untreated Leacril and Leacril treated with tannic acid by Lewis acid-base interactions. Copyright 1998 Academic Press.

Journal Article↗
PubMed1997

Cross-sensitizations between azo dyes and para-amino compound. A study of 236 azo-dye-sensitive subjects.

Combined sensitizations to different azo dyes, probably based both on true cross-sensitization and on simultaneous positive reactions, have frequently been described. However, since azo dyes are included in the standard series in a minority of countries, the case studies considered comprise, with few exceptions, a small number of subjects. The aim of our study was to investigate cross-reactions between different azo dyes and para-amino compounds in azo-dye-sensitive subjects, to study the clinical aspects of azo dye dermatitis, to assess the relevance of sensitization to azo dyes, and to relate the pattern of cross-sensitizations to the chemical structure of the different dyes. Out of 6203 consecutively tested patients, 236 were sensitized to at least 1 of 6 azo compounds employed as textile dyes, included in our standard series. 107 subjects reacted to Disperse Orange 3 (DO3), 104 to Disperse Blue 124 (DB124), 76 to p-aminoazobenzene (PAB), 67 to Disperse Red 1 (DR1), 42 to Disperse Yellow 3 (DY3), and 31 to p-dimethylaminoazobenzene (PDAAB). Co-sensitizations to para-phenylenediamine were present in most subjects sensitized to DO3 (66%) and PAAB (75%), in 27% and 36% of DR1 and DY3-sensitive subjects, and only in 16% of subjects sensitized to DB124. Apart from the hands and the face, the neck and the axillae were the most frequently involved skin sites. Whereas the involvement of flexural areas was mainly connected with sensitization to DB124, in patients with hand dermatitis and in those working as hairdressers, sensitization to DO3 and PAAB was more frequent. Moreover, in the former patient group, a history of textile dye allergy was most frequently obtained. Out of 33 patients tested with an additional textile dye series, only 5 subjects reacted to anthraquinone dyes. Cross-sensitizations between azo dyes and para-amino compounds can partially be explained on the basis of structural affinities.

Azo Compounds↗
PubMed1996

Multiple azo disperse dye sensitization mainly due to group sensitizations to azo dyes.

A female patient, with a previous episode of contact dermatitis caused by a blue dress, developed similar dermatitis due to a navy-blue dress. Patch tests revealed multiple allergic positive reactions to paraphenylenediamine (PPD), the navy-blue dress, its extracts, 6 azo disperse dyes in a textile series, as well as 3 dye components, including Disperse (DP) Red 153, which were present in the dress; these were composed of 9 azo disperse dyes, all dyes being of a different chemical structure. On the basis of chemical similarities between these 16 azo dyes including PPD, these are classified into the following 4 groups: thiazol-azoyl-PPD group (including DP Blue 106, DP Blue 124 and 5 used dyes), aminoazobenzene group (DP Red 1, DP Red 17, DP Brown 1 and 2 used dyes), PPD group (PPD and DP Orange 3) and benzothiazol-azoyl-PPD group (2 dyes in DP Red 153). With few exceptions, cross-sensitizations between dyes in the same group have been reported by other authors, or are suggested by us, in the former 3 groups. Multiple azo disperse dye sensitization is therefore considered to be attributable mainly to group sensitizations to azo dyes.

Aniline Compounds↗