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At least 91 records · Page 5Linked to original sources
PubMed2005

Randomized clinical trial comparing blue dye with combined dye and isotope for sentinel lymph node biopsy in breast cancer.

BACKGROUND: Use of blue dye alone as a marker for sentinel lymph node (SLN) biopsy is effective, but combining it with isotope marking can improve the success rate. Use of the isotope adds extra cost and there are potential radiation hazards. The two techniques were compared in a randomized trial. METHODS: Women with early breast cancer (less than 3 cm) and no palpable axillary nodes were recruited. Women older than 70 years with multicentric cancers or previous surgery to the breast or axilla were excluded. Patients were randomized to either blue dye alone or combined mapping for SLN biopsy. All women had a level I and II axillary dissection after the SLN biopsy. RESULTS: A total of 123 patients were recruited, of whom five were excluded from analysis. Blue dye alone was used in 57 women and 61 had combined mapping. Baseline demographic data were similar in the two cohorts. The success rate of SLN biopsy was higher with combined mapping than with blue dye alone (100 versus 86 per cent; P = 0.002). The accuracy and false-negative rate were similar (accuracy 100 per cent for combined mapping versus 98 per cent for blue dye; false-negative rate 0 versus 5 per cent). CONCLUSION: Combined mapping was superior to blue dye alone in identification of the SLN, but accuracy and false-negative rates were similar.

Breast Neoplasms↗
PubMed2000

Mechanism of dye binding in the protein assay using eosin dyes.

Eosin B and eosin Y have been used to estimate micro- and submicrogram quantities of proteins respectively as shown in our previous reports. In the present study we describe the mechanism of eosin binding to proteins. At pH lower than 3.0 the absorbance of unbound dye is greatly reduced. After the dye binds to protein, the absorption maximum of the dye changes from 514 to 530 +/- 5 nm. The absorbance and bathochromatic shift in absorption maximum of the protein-dye complex are proportional to the concentration of protein. The pH of the assay solution does not change due to protein. Arginine, histidine, and lysine (at both acidic and neutral pH) and tryptophan (at acidic pH) residues of a protein bind electrostatically to carboxylic and phenolic groups of the dye to produce a stable water-soluble protein-dye complex. The binding constants of eosin B with poly-L-arginine, poly-L-histidine, poly-L-lysine, and poly-L-tryptophan at pH 1.96 are 0.37, 0.32, 0.33 and 0.33 nmol/nmol of amino acid, respectively. The binding constants of eosin B and eosin Y with bovine serum albumin (BSA) at pH 1.96 are essentially the same, i.e., 0.82 nmol/nmol of reactive amino acid of BSA. The binding constant varies with solution pH so that a wide range of protein concentrations can be estimated. The reason for the higher absorbance of protein-eosin Y complex compared to that of protein-eosin B complex is discussed.

Animals↗
PubMed2001

Interaction of cyanine dyes with nucleic acids. XVIII. Formation of the carbocyanine dye J-aggregates in nucleic acid grooves.

Spectral properties of carbocyanine dye 3-methyl-2-[3-methyl-2-(3-methyl-2,3-dihydro-1,3-benzothiazole-2-iliden)-1- butenyl]-1,3-benzothiazole-3-il iodide (Cyan betaiPr) in water solution, as well as in the presence of different types of double stranded DNA have been studied. While in water solution of 'free' dye Cyan betaiPr stays mainly in monomeric form, in the presence of DNA the dye molecules form J-aggregates. The molecular structure of these J-aggregates causes the Davydov splitting of their absorption band, corresponding to the first electronic transition. A study of site-specificity showed that in the presence of poly (dA/dT) the majority of Cyan betaiPr molecules form J-aggregates, while in the presence of poly (dGC/dGC) dye molecules stay mainly in monomeric form and in presence of chicken erythrocytes DNA both J-aggregate and monomeric forms of dye are present. We suppose that Cyan betaiPr molecules aggregate in DNA groove, which serves as a template for J-aggregate forming. An increase of ionic strength of solution leads to the release of dye molecules from DNA grooves and prevents J-aggregates formation.

Absorption↗
PubMed1998

Rose bengal dye concentration and volume delivered via dye-impregnated paper strips.

PURPOSE: The technique of administration and the resulting volume and concentration of the dye delivered to the eye via dye-impregnated paper strips are not standardized or known. The purpose of this study was to use a standard technique for preparation of rose bengal dye from commercially available paper strips to determine the variability in concentration based upon soak time, and to determine the volume delivered by such a technique to a model eye. METHODS: Rose bengal filter paper strips were wetted for either 15, 30, or 45 s, and the resulting concentration of dye eluted was determined by spectrophotometry. With the same preparation technique and a 15-s soak time, the strip was applied to wetted filter paper, as a model for the moist surface of the eye. The volume of solution delivered was calculated by weight. RESULTS: Concentrations of rose bengal for the various soak times were: 15 s: 7.64 (+/- 1.11) by 10(-6) g/ml; 30 s: 9.70 (+/- 1.79) by 10(-6) g/ml; and 45 s: 10.27 (+/- 0.66) by 10(-6) g/ml. The volume delivered to the eye model with this technique was 17.43 microliters (+/- 3.09). CONCLUSIONS: The concentration of rose bengal dye delivered to the ocular surface by means of a wetted strip is relatively low and soak time/technique-dependent. This suggests a possibility that results in clinical studies with rose bengal strip application may be different than if controlled volume applications of commercially available 1% liquid rose bengal dye are used.

Cornea↗
PubMed1975

Comparison of the cardiac output measurements with electromagnetic flowmeter and dye-dilution technique in dogs, with a note on the comparison between radiocardiography and ear-dye method in man.

There are relatively few studies and opinions are still divided as to the agreement between the electromagnetic flowmeter and dye-dilution technique in measurements of cardiac output in animals. Of 22 pairs of cardiac output measurements performed with an electromagnetic flow probe applied to the root of aorta in open-chest, anesthetized dogs and with peripheral venous injection of indocyanine green dye and an arterial cuvette, the measured points fell within the range of plus or minus 20% on both sides of the line of identity in 19 instances. Studied on 8 human subjects with radiocardiography and ear-dye method performed simultaneously with peripheral venous injection of a mixture of R131ISA and indocyanine green, cardiac output given by ear-dye method was higher than that given by radiocardiography by an average of 9 plus or minus 11 (SD)%. Agreement and disagreement in cardiac output measurements given by electromagnetic flow probe, dye-dilution method with arterial cuvette, dye-dilution method with ear-piece densitometer and radiocardiography were discussed.

Animals↗
PubMed2005

Evaluation of laser fluorescence for differentiating caries dye-stainable versus caries dye-unstainable dentin in carious lesions.

PURPOSE: To assess the performance of laser fluorescence (DIAGNOdent, "DD") for differentiating carious versus non-carious dentin during caries excavation using caries dye as the gold standard. METHODS: The superficial carious dentin surfaces of lesions in 25 teeth were exposed, and the surface evaluated by DD. Next, caries dye was applied and the surface was observed for dye staining. The lesion was then excavated approximately 0.5 mm with a round bur. The resulting surface was evaluated by DD, and the above sequence was repeated until three non-stained surfaces were evaluated by DD. Using "caries dye staining" as the gold standard, correct classification proportion was calculated at each DD cutpoint in the dataset. Using the optimal cutpoint, sensitivity, specificity and likelihood ratios were calculated. Non-parametric ROC analysis was performed and AUC calculated. RESULTS: With an optimal cutpoint of 11 or 12, DD was highly accurate in discriminating between dye-stainable and dye-unstainable surfaces, producing a correct classification proportion of over 98% and an AUC of 0.999 for all 176 surfaces. These results support further refinement of DD for use in caries excavation and further research relating DD to other caries excavation endpoints.

Dental Caries↗
PubMed1985

[Hydrophobic acridine dyes for fluorescent staining of mitochondria in living cells. 3. Specific accumulation of the fluorescent dye NAO on the mitochondrial membranes in HeLa cells by hydrophobic interaction. Depression of respiratory activity, changes in the ultrastructure of mitochondria due to NAO. Increase of fluorescence in vital stained mitochondria in situ by irradiation].

The hydrophobic fluorescence dye 10-n-nonyl-acridinium-orange-chloride, NAO, stains specifically the mitochondria of living HeLa-cells. A dye concentration of 1 X 10(-8) M is sufficient for vital staining and at 5 X 10(-7) M an incubation time less than 1 min is enough to generate the bright green fluorescence of the mitochondria. The retention of NAO by the mitochondria is longer than 7 days. The dye accumulation is not affected by the ionophores valinomycin, nigericin, gramicidin, the uncoupling agents DNP, CCCP or by ouabain. In contrast to Rh 123 the trans-membrane potential is not the driving force of the NAO accumulation. We assume that NAO is bound to the hydrophobic lipids and proteins in the mitochondrial membranes by hydrophobic interaction. With valinomycin, 500 ng/ml, 10 min, the mitochondria in HeLa-cells swell. Now it is possible to observe some details in the enlarged mitochondria by light microscopy. After vital staining with NAO, 5 X 10(-7) M, 10 min, the periphery of the swollen mitochondria shows an intense green fluorescence, the inner part is dark. Obviously the dye is bound to the membranes. By electron microscopy it can be shown that the valinomycin treated and NAO stained mitochondria have outer and inner membranes and cristae. They differ from untreated mitochondria mainly in the size. After incubation of the HeLa-cells with relatively high NAO concentrations, 5 X 10(-6) M, 10 min, the mitochondria show a weak orange fluorescence. It is generated by the dimers D of NAO. Therefore the dye concentration in the mitochondrial membranes is locally very high and causes dye dimerisation. The weak orange fluorescence is instable and disappears within a few seconds. Instead we observe a green fluorescence with growing intensity that is generated by the monomers M of NAO. The intensity has its maximum value after a few seconds. Using low NAO concentrations for incubation, 1 X 10(-7) M, 10 min, we observe only the green fluorescence with increasing intensity. In this case the orange fluorescence is too weak for observation (concentration quenching). It can be shown by experiments and quantum mechanics that the orange fluorescence is assigned to an optical forbidden, the green fluorescence to an allowed electronic transition of D or M respectively. Our results indicate a dissoziation of D in 2 M by irradiation of the mitochondria under the fluorescence microscope.(ABSTRACT TRUNCATED AT 400 WORDS)

Aminoacridines↗
PubMed1995

Utility of intensely fluorescent cyanine dyes (Cy3) for assay of gap junctional communication by dye-transfer.

Utilization of a class of fluorescent cyanine dyes (Cy3) for the assay of gap junctional communication by the dye transfer method was examined. When compared with Lucifer Yellow (LY), a commonly used tracer, microinjected Cy3 dye was found to yield similar degrees of cell coupling. Blockade of the transfer of both tracers by 12-O-tetradecanoylphorbol-13 acetate (TPA), which is known to cause closure of communicating channels, confirmed gap junctional mediation of dye movement. The fixability of a microinjected amine derivative of Cy3 dye demonstrated its compatibility with immunostaining protocols involving fluorescein isothiocyanate (FITC)-conjugated reagents. These results together with the brilliant fluorescence of Cy3 dyes suggest the potential of Cy3 reagents as additional tools to study gap junction function.

Animals↗
PubMed2004

Adsorption of anionic dyes on chitosan beads. 1. The influence of the chemical structures of dyes and temperature on the adsorption kinetics.

In this work, chitosan beads were synthesized in acidic medium and cross-linked in 1% glutaraldehyde solution. The characterization of the materials using TG/DTG, XRD, and BET surface areas showed that the beads did not modify their characteristics after the cross-linking reaction. The cross-linked beads were utilized as adsorbents for the removal of the yellow-, blue-, and red-anionic reactive dyes from aqueous solutions at pH 2.0. Adsorption of the yellow-dye increased from 25 to 50 degrees C. However, adsorption of the blue-dye decreased from 25 to 50 degrees C. Interestingly, the adsorption of the red-dye decreased from 25 to 35 degrees C and increased from 45 to 50 degrees C. The kinetic data were evaluated using an Avrami kinetic model, where the parameter n was related to the determination of changes in the adsorption mechanisms. Adsorption data of the dyes in relation to the contact time, the chemical structures of the dyes, and temperature were presented and were discussed.

Adsorption↗
PubMed2005

Sonochemical degradation of azo dyes in aqueous solution: a new heterogeneous kinetics model taking into account the local concentration of OH radicals and azo dyes.

The sonochemical decolorization and decomposition of azo dyes, such as C. I. Reactive Red 22 and methyl orange, were performed from the viewpoints of wastewater treatment and to determine the reaction kinetics. A low concentration of the azo dye solution was irradiated with a 200 kHz and 1.25 W/cm2 ultrasound in a homogeneous aqueous solution. The azo dye solutions were readily decolorized by the irradiation. The sonochemical decolorization was also depressed by the addition of the t-butyl alcohol radical scavenger. These results indicated that azo dye molecules were mainly decomposed by OH radicals formed from the water sonolysis. In this paper, we propose a new kinetics model taking into account the heterogeneous reaction kinetics similar to a Langmuir-Hinshelwood mechanism or an Eley-Rideal mechanism. The proposed kinetics model is based on the local reaction site at the interface region of the cavitation bubbles, where azo dye molecules are quickly decomposed because an extremely high concentration of OH radicals exists in this region. To confirm the proposed kinetics model, the effects of the initial concentration of azo dyes, irradiated atmosphere and pH on the decomposition rates were investigated. The obtained results were in good agreement with the proposed kinetics model.

Journal Article↗