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At least 217 records · Page 12Linked to original sources
PubMed2005

Treatment of port wine stains with photodynamic therapy, using pulsed dye laser as a light source, compared with pulsed dye laser alone: a pilot study.

BACKGROUND AND OBJECTIVES: Laser-induced photo thermal damage has been combined with photodynamic therapy (PDT) using a systemic photosensitiser to treat vascular lesions. The efficacy of PDT using systemic 5-aminolaevulinic acid (5-ALA) as the photosensitiser and pulsed dye laser (PDL) as the light source in port wine stains (PWS) is unknown. STUDY DESIGNS/MATERIALS AND METHODS: We conducted an internally controlled pilot study comparing the efficacy of PDT using PDL as a light source, to PDL alone in the treatment of PWS. RESULTS: The PWS improved slightly in all patients but no significant difference was found between the three treatment arms in terms of lesional lightening or incidence and severity of side effects. CONCLUSIONS: There was no evidence of increased efficacy of PDT using PDL as a light source compared to PDL alone. There was also no significant difference in adverse events. Further studies using different treatment regimens over longer periods of time may be warranted.

Adult↗
PubMed1999

Simultaneous videofluoroscopic swallow study and modified Evans blue dye procedure: An evaluation of blue dye visualization in cases of known aspiration.

The reliability of the modified Evans blue dye (MEBD) test for the detection of aspirated materials in patients with tracheostomy has been questioned. The videofluoroscopic swallow study (VFSS) has been the standard procedure used to detect aspiration, but there are known risks and the VFSS is not always an available evaluation option for aspiration detection. The purpose of the present study was to investigate the visualization of blue tracheal secretions in cases of known aspiration as documented by the VFSS. Twenty consecutive simultaneous MEBD study and VFSS were completed on patients with tracheostomies at an acute rehabilitation hospital. Overall, the MEBD showed a 50% false-negative error rate. The MEBD identified aspiration in 100% of patients who aspirated more than trace amounts but failed to identify aspiration of trace amounts (0%).

Adolescent↗
PubMed1996

Receptor inactivation by dye-neuropeptide conjugates: 1. The synthesis of Cys-containing dye-neuropeptide conjugates.

In an attempt to attenuate specifically identified receptors through photolysis, a four-step synthesis is of a useful tethered derivative of Azure-B (Az) was developed After characterization, this derivative was covalently attached to CFMRFamide, CFMRF, and CLRFamide (i.e., three different neuropeptide analogues of the putative neurotransmitter FMRFamide. This resulted in the formation of three dye-neuropeptide conjugates: Az-CFMRFamide, Az-CFMRF, and Az-CLRFamide.

Azure Stains↗
PubMed1992

Purification of biologically active human plasma transthyretin by dye-affinity chromatography: studies on dye leakage and possibility of heat treatment for virus inactivation.

The application of a purification procedure for the industrial preparation from human plasma of a therapeutic protein may be hindered by several safety concerns. The dye leaching from Remazol Yellow GGL-Sepharose used for the affinity chromatography of human plasma transthyretin was quantitatively studied by a sensitive competitive enzyme immunoassay. The possibility of including a heat treatment step for virus inactivation in the purification process while preserving the biochemical and functional characteristics of the protein is also reported.

Azo Compounds↗
PubMed2001

Optical determination of low-level water concentrations in organic solvents using fluorescent acridinyl dyes and dye-immobilized polymer membranes.

The fluorescent acridinyl indicators 4-(9-acridinyl)-N-(5-hexenyl)-N-methylaniline (KD-F0011), 6-(9-acridinyl)-1,2,2,3-tetramethyl-2,3-dihydro- 1H-perimidine (KD-F0021), and 6-(9-acridinyl)-2-(3-butenyl)-1,2,3-trimethyl-2,3-dihydro-1H-perimidine (KD-F0022) were designed, synthesized, and applied for highly sensitive optical determination of low-level water in organic solvents. All these dyes were found useful as fluorescence indicators for the detection of water below 1% (v/v) in different solvent media with a low detection limit of 0.002% (v/v) or 20 mg/L (22 ppm by weight) for KD-F0021 in THF solution. Sensing membranes made from poly(ethylene glycol) dimethacrylate by photocopolymerization with the indicator KD-F0011 were also prepared. Using the membrane sensor, the lowest detection limit of 0.001% (v/v) or 14 mg/L (20 ppm) water was achieved in diethyl ether samples. This system enables the continuous monitoring of the water content in a flow-through arrangement, where single-wavelength excitation (404 nm) and single-wavelength detection (532 mm) can be used for the fluorescence determination, allowing a simple measurement setup. In a continuous-flow experiment using THF samples, fully reversible and fast signal changes with t95% = 1-2 min for water concentrations up to 0.50% (v/v) were observed. A detection limit of 0.004% (v/v) or 40 mg/L (45 ppm) water in THF was achieved. These characteristics make this type of sensor a useful tool for the online continuous monitoring of water present as an impurity in organic media, which is difficult to achieve using a Karl Fischer instrument.

Journal Article↗
PubMed2005

Synthesis, structure, and properties of [Pt(II)(diimine)(dithiolate)] dyes with 3,3'-, 4,4'-, and 5,5'-disubstituted bipyridyl: applications in dye-sensitized solar cells.

A family of [Pt(II)(diimine)(dithiolate)] complexes of general formula [Pt{X,X'(CO(2)R)(2)-2,2'-bipyridyl}(maleonitriledithiolate)] (where X = 3, 4, or 5 and R = H or Et) have been synthesized, spectroscopically and electrochemically characterized, and attached to a TiO(2) substrate to be tested as solar cell sensitizers. A single-crystal X-ray structure showing a large torsion angle between the bipyridyl rings was determined for [Pt{3,3'(CO(2)Et)(2)-2,2'-bipyridyl}(maleonitriledithiolate)].MeCN. The effect of changing the position of the bipyridyl substituents from 3,3' to 4,4' and 5,5' is discussed with reference to structural and electronic changes seen within the different members of the family of molecules. The first UV/vis/NIR spectroelectrochemical study of complexes of this general formula is discussed. All three complexes (where R = H) were tested as solar cell sensitizers, with the 3,3'-disubstituted bipyridyl complex giving an intermediate dye loading value but superior photovoltaic performance to those of the other two. The performance of this sensitizer is then compared with that of a well-known Ru polypyridyl sensitizer, the ditetrabutylammonium salt of [RuL(2)(NCS)(2)] (L = 2,2'-bipyridyl-4,4'-dicarboxylato), commonly called N719.

Journal Article↗
PubMed2003

Novel polyene dyes for highly efficient dye-sensitized solar cells.

We have developed an efficient and novel polyene-dye-sensitized nanocrystalline TiO2 solar cells producing a 6.8% solar energy-to-electricity conversion efficiency (eta) under AM 1.5 irradiation (100 mW cm(-2)): short-circuit current density (Jsc), 12.9 mA cm(-2), open-circuit photovoltage (Voc), 0.71 V, fill factor (ff), 0.74.

Coloring Agents↗
PubMed2003

A swift dye uptake procedure for dye sensitized solar cells.

Solar cells based on swift self-assembled sensitizer bis(tetrabutylammonium)-cis-di(thiocyanato)-N,N'-bis(4-carboxylato-4'-carboxylic acid-2,2'-bipyridine)ruthenium(II) (N719) on double layers of 12 + 4 microm thick nanocrystalline TiO2 films exhibit the incident monochromatic photon-to-current conversion efficiency (IPCE) 90% and show a short circuit current density of 17 mA cm(-2), 750 mV open circuit potential and 0.72 fill factor yielding power conversion efficiencies over 9.18% under AM 1.5 sun. For the first time highest power conversion efficiencies are obtained for dye sensitized solar cells using a swift self-assembled procedure.

Journal Article↗
PubMed1978

The dye-linked alcohol dehydrogenase of Rhodopseudomonas acidophila. Comparison with dye-linked methanol dehydrogenases.

1. A dye-linked alcohol dehydrogenase was purified 20-fold from extracts of Rhodopseudomonas acidophila 10050 grown anaerobically in the light on methanol/HCO3-. 2. The enzyme resembled many previously reported methanol dehydrogenases from other methylotrophic organisms in coupling to phenazine methosulphate, requiring ammonia as an activator, possessing a pH optimum of 9 and a mol.wt. of approx. 116000. In many other respects the enzyme showed singular properties. 3. The stability of the enzyme under various conditions of temperature and pH was studied. 4. Primary aliphatic amines containing up to nine carbon atoms (the longest tested) were better activators than ammonia. 5. A wide range of primary alcohols and aldehydes served as substrates, with apparent Km values ranging from 57 mM for methanol to 6 micron for ethanol. 6. O2 was an inhibitor competitive with respect to the alcohol substrate. In the presence of O2, apparent Km values of 145 mM were recorded for methanol. 6. Cyanide and alphaalpha'-bipyridine were inhibitors competitive with respect to the amine activator. 7. The properties of the enzyme from Rhodopseudomonas acidophila are compared with those of similar enzymes from other organisms, and implications of the salient differences are discussed.

2,2'-Dipyridyl↗
PubMed2006

Comparison of the effects of pulsed dye laser, pulsed dye laser + salicylic acid, and clobetasole propionate + salicylic acid on psoriatic plaques.

BACKGROUND: Studies show that pulsed dye laser (PDL) has some clinical benefits on psoriasis with a low clearance rate. In addition, it has been suggested that applying keratolytics before treatment might be helpful in PDL therapy. Topical corticosteroids remain the most commonly prescribed agents for psoriasis. OBJECTIVE: This study was designed to compare the efficacy of the PDL treatment with that of PDL treatment after salicylic acid on psoriatic plaques. The other goal of this study was to compare the efficacy of the PDL treatment with that of clobetasol propionate treatment. METHODS: Twenty-two patients with chronic, stable psoriatic plaques that involved less than 20% of their body were included in the study. Three similar-appearing psoriasis plaques in these patients were selected. Whereas the first plaque received only PDL, the second plaque received PDL after salicylic acid, and the third plaque received clobetasol propionate ointment and salicylic acid. Evaluation of the study plaques was carried out by the modified Psoriasis Area and Severity Index (mPASI) score and by measuring the area of the plaques. RESULTS: Of the 21 patients, 19 completed the study. Although the decrease in mPASI scores was determined to be maximum for clobetasol propionate + salicylic acid-treated plaques and minimum for only PDL-treated plaques, the decrease was statistically significant in all groups when compared with baseline (p < .003). At the 3- and 6-week evaluations, there was a statistically significant difference between clobetasol propionate + salicylic acid-treated plaques and the two PDL-treated plaques (p < .003); however, the difference observed at the 9-, 12-, and 15-week evaluations was statistically significant only between clobetasol propionate + salicylic acid-treated plaques and PDL-treated plaques (p < .003). When the baseline and 15-week evaluations were compared, there was no statistically significant increase in the mean lesion areas of clobetasol propionate + salicylic acid-treated psoriatic plaques (p > .003), but there was a statistically significant increase in the mean lesion areas of two PDL-treated psoriatic plaques (p < .003). CONCLUSION: The results of this study showed that the effect of PDL could be increased when salicylic acid was added to treatment, although there was no statistically significant difference between both treatment protocols. However, clobetasol propionate + salicylic acid treatment is more effective than both PDL and PDL + salicylic acid treatment.

Adult↗
PubMed2006

Verruca vulgaris: pulsed dye laser therapy compared with salicylic acid + pulsed dye laser therapy.

BACKGROUND: In recent years, lasers have been used in verruca therapy and some successful results have been obtained in some types of verruca. In some of these laser studies, peeling processes have been used to increase penetration. OBJECTIVE: This study aimed to compare the effects of pulsed dye laser (PDL) therapy with the effects of PDL therapy following salicylic acid (SA) application. The purpose of the SA application is to increase the laser penetration by decreasing the hyperkeratosis of verruca vulgaris. METHODS: This controlled study included 66 lesions from 19 patients enrolled in the study. PDL was applied to 33 lesions following 30% SA application twice a day for 5 days, and the remaining 33 lesions underwent PDL therapy. PDL was administered in both groups at 4-week intervals varying from one to five sessions. In the comparison of these two groups, the changes in verruca dimensions were recorded in width x length x height (mm3), and the results of the therapy were evaluated statistically. RESULTS: In both PDL and SA + PDL groups, the regressions observed in the size of the lesions were statistically significant at the end of the fifth session compared with those observed at the onset of the therapy (P < 0.05). At the end of the fifth session, the difference between the two groups was not statistically significant (P = 0.451); however, the clearance rate in the SA + PDL group was more statistically significant than that in the PDL group after the second session (P = 0.049). The complete clearance rate in the SA + PDL group was 54.6% after the second session, but 66.4% in the PDL group only after the fifth session. Complete clearance in the SA + PDL group was observed after 2.2 sessions, and in the PDL group after 3.1 sessions (P < 0.05). CONCLUSIONS: Although there was no difference between the clearance rate of the SA + PDL group and that of the PDL group after the fifth session, adding SA to PDL decreased the number of sessions to a large extent.

Adolescent↗
PubMed1997

Localization of the Enzyme System Involved in Anaerobic Reduction of Azo Dyes by Sphingomonas sp. Strain BN6 and Effect of Artificial Redox Mediators on the Rate of Azo Dye Reduction.

The effect of different artificial redox mediators on the anaerobic reduction of azo dyes by Sphingomonas sp. strain BN6 or activated sludge was investigated. Reduction rates were greatly enhanced in the presence of sulfonated anthraquinones. For strain BN6, the presence of both cytoplasmic and membrane-bound azo reductase activities was shown.

Journal Article↗
PubMed1975

Tartrazine: solid-phase radioimmunoassay studies of an azo dye implicated in allergic reactions (azo dyes and allergy).

A solid-phase radioimmunoassay procedure was adapted for the haptenic study of tartrazine, an azo dye implicated in various forms of allergy. Further, the haptenic relationship of tartrazine and aspirin was investigated, since sensitivity of individuals to the two substances is often clinically associated. The specificity of antibody to tartrazine was directed strongly toward a pyrazolone intermediate of the molecule, 1-(4-sulfophenyl)-3-carboxy-5-hydroxy-pyrazole. Aspirin did not cross-react with anti-tartrazine, suggesting that the clinical association of aspirin and tartrazine sensitivity in patients is a nonimmunological phenomenon.

Antigens↗
PubMed1999

Affinity labeling of annexin VI with a triazine dye, Cibacron blue 3GA. Probable interaction of the dye with C-terminal nucleotide-binding site within the annexin molecule.

Annexin VI (AnxVI) from porcine liver, a member of the annexin family of Ca(2+)- and membrane-binding proteins, has been shown to bind ATP in vitro with a K(d) in the low micromolar concentration range. However, this protein does not contain within its primary structure any ATP-binding consensus motifs found in other nucleotide-binding proteins. In addition, binding of ATP to AnxVI resulted in modulation of AnxVI function, which was accompanied by changes in AnxVI affinity to Ca2+ in the presence of ATP. Using limited proteolytic digestion, purification of protein fragments by affinity chromatography on ATP-agarose, and direct sequencing, the ATP-binding site of AnxVI was located in a C-terminal half of the AnxVI molecule. To further study AnxVI-nucleotide interaction we have employed a functional nucleotide analog, Cibacron blue 3GA (CB3GA), a triazine dye which is commonly used to purify multiple ATP-binding proteins and has been described to modulate their activities. We have observed that AnxVI binds to CB3GA immobilized on agarose in a Ca(2+)-dependent manner. Binding is reversed by EGTA and by ATP and, to a lower extent, by other adenine nucleotides. CB3GA binds to AnxVI also in solution, evoking reversible aggregation of protein molecules, which resembles self-association of AnxVI molecules either in solution or on a membrane surface. Our observations support earlier findings that AnxVI is an ATP-binding protein.

Adenosine Triphosphate↗
PubMed2004

Squaraine dyes for photodynamic therapy: mechanism of cytotoxicity and DNA damage induced by halogenated squaraine dyes plus light (>600 nm).

Halogenated squaraine dyes 1 and 2 possess favorable photophysical and in vitro photobiological properties that make these new class of molecules interesting for photodynamic therapeutic applications. For a better understanding of the mechanism of their photobiological activity, we have analyzed the DNA damage and the cytotoxicity induced by these photosensitizers in mammalian cells and cell-free systems in the presence and absence of various additives and scavengers. Both photoactivated squaraines were found to be similar efficient in inducing single-strand breaks (SSB) in cell-free DNA when compared with the cellular DNA. Superoxide dismutase and catalase did not show any influence. However, the presence of tert-butanol and glutathione inhibited the formation of the DNA SSB, indicating an indirect (possibly squaraine radical mediated) mechanism under cell-free conditions. Replacing H2O in the buffer by D2O resulted in a five- to six-fold increase in the number of the SSB in cell-free DNA and a significant enhancement of the photocytotoxicity in mouse lymphoma cells. The results demonstrate that singlet oxygen is the major reactive species under cell-free and cellular conditions and confirm that squaraine-based sensitizers 1 and 2 can have potential applications in photodynamic therapy.

Animals↗
PubMed1982

A series of inhibitors of azo dye hepatocarcinogenesis partially reverse the azo dye-induced decrease in liver RNA/DNA ratio.

The DNA and RNA content and the mitotic index were determined in the livers of rats pair-fed for 10 days on a control diet, and diets containing 0.06% 3'-methyl-4-dimethylaminoazobenzene (3'MeDAB), either alone or in combination with the inhibitors of azo dye carcinogenesis acetanilide (0.08%), p-hydroxypropiophenone (PHP, 1%), urea (5%), dehydroacetic acid (DHAA, 0.25%), butylated hydroxytoluene (BHT, 0.3%) and 3-methylcholanthrene (3MC, 0.067%). The liver RNA/DNA ratio was increased in rats fed the 3'MeDAB diet following ingestion of each of the inhibitor plus carcinogen-containing diets. The increases were significant except in the instance of urea. The increase was mainly due to increased RNA content in rats fed 3'MeDAB plus acetanilide, DHAA, BHT and 3MC when compared with rats fed 3'MeDAB alone. In rats fed PHP and 3'MeDAB, an increase in total liver DNA that was noted in rats fed 3'MeDAB alone did not take place, while total liver RNA content was similar in both groups; the RNA/DNA ratio was therefore greater in rats protected from 3'MeDAB carcinogenesis by PHP. The results are discussed in relationship to the effects of carcinogens on RNA forming genes and the role of the nucleolus in cell differentiation.

Acetanilides↗