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Prolonged retinal arterio-venous circulation time by fluorescein but not by indocyanine green angiography in birdshot chorioretinopathy.

PURPOSE: To compare retinal arterio-venous circulation time by fluorescein (FA) and indocyanine green angiography (ICGA) in birdshot chorioretinopathy. METHODS: We analyzed prolonged retinal arterio-venous fluorescein transit time, a known feature in birdshot chorioretinopathy and correlated it with ICGA findings in four consecutive patients. RESULTS: Mean retinal arterio-venous fluorescein circulation time was 31.1 +/- 5.2 seconds, a transit time significantly longer than in a group of ten patients with sarcoidosis (9.45 +/- 3.36 sec., p < 0.0001) and in a group of three cases with Vogt-Koyanagi-Harada disease (7.0 +/- 1.1 sec., p < 0.0001). CONCLUSION: Prolonged fluorescein arterio-venous transit time seems to be a characteristic feature of birdshot chorioretinopathy that does however not reflect the actual intravascular hemodynamic situation but diffuse blood-retinal barrier damage allowing exudation, slow gradual tissue impregnation and delayed venous reabsorption of small molecules like fluorescein.

Aged↗

Microspectrophotometric analysis of accumulation of the fluorones K-fluorescein, rose Bengal and phloxine red in living plant cells.

Spectrophotometric investigations of dye solutions in different media and of living stained cells from the upper epidermis of the scaleleaf of Allium cepa were carried out with the dyes K-fluorescein, rose Bengal and phloxine red to elucidate the mechanism of the accumulation of these dyes in the cytoplasm, the nucleus and the cell sap. Thin layer chromatography and paper electrophoresis indicate that the K-fluorescein used here contains no detectable contaminants. Besides the main component, rose Bengal contains two components in small quantities with Rf values of 0.64 and 0.57, plus three more components in traces. Besides the two main components (Rf values of 0.83 and 0.73), phloxine red also contains five more components in traces. Electrophoretic investigations reveal that in aqueous solution the fluorones rose Bengal and phloxine red from pH 2.0-11 show a migration toward the anode. K-fluorescein from pH 2.9-10.4 shows a migration toward the anode, but at pH 1.9 a migration toward the cathode. By shaking aqueous solutions of K-fluorescein, rose Bengal and phloxine red at different pH values with different organic solvents, the above used stainings show different spectral absorption curves according to the polarity of the solvent. The position of the absorption maxima and the shape of the absorption curves of these three anionic dyes lead to the conclusion that the staining of the living cytoplasm and nucleus is due to ion accumulation by means of the "ion trap mechanism" within the aqueous phase of the cytoplasm (cytosol) and the nucleus. Adsorption of dye particles in the protein phase of the cytoplasm cannot be excluded. There seems to be a fundamental difference in the vital staining of the protoplasm by anionic and cationic dyes, the latter apparently accumulating as neutral dye molecules in the lipid phase of the protoplasm. The concentration of the dyes used in the living cytoplasm (cytosol) is approximately 0.2-0.05%. During natural and artificial displacement of K-fluorescein from the cytoplasm to the vacuole, it appears that accumulation of the dye within the vacuole is performed through an ion trap mechanism in the form of bivalent ions. Along with natural displacement, it is possible that ion accumulation also occurs in metabolic products.

Allium↗

Superficial temporal artery to middle cerebral artery anastomosis. Intraoperative evaluation by fluorescein angiography and xenon-133 clearance.

Fluorescein angiography and xenon-133 (133Xe) clearance studies were performed during surgery on 15 patients who were undergoing superficial temporal artery (STA) to middle cerebral artery (MCA) anastomosis. Fourteen patients had occlusive disease of the internal carotid artery (ICA), and one patient had severe stenosis of the MCA. Before anastomosis, fluorescein angiography showed slow filling of the MCA branches through collateral channels. Focal areas of impaired microcirculatory filling and washout were seen in the territory of severely sclerotic cortical arteries. The findings of preanastomotic 133Xe clearance studies were variable and a uniform pattern of regional cerebral blood flow (rCBF) changes was not defined. In 55% of the patients, rCBF was reduced to 25 ml/100 gm/min or less at one or more detector sites. Fluorescein angiography provided an immediate assessment of anastomotic patency and clearly displayed the distribution of blood entering the epicerebral circulation through the STA. In 67% of patients, multiple MCA cortical branches filled with fluorescein, whereas in 33% filling was restricted to the receptor artery territory. An immediate, substantial (greater than or equal to 15 ml/100 gm/min) increase in rCBF was demonstrated in 73% of patients after anastomosis. The rCBF changes were consistently better in patients with donor and receptor arteries greater than 1 mm in diameter. Redistribution of collateral input acted to increase rCBF in areas distant from the anastomotic site. Some improvement in fluorescein circulation and rCBF also was seen in cortex supplied by sclerotic MCA branches.

Adolescent↗

Fluorescence-guided resection of glioblastoma multiforme by using high-dose fluorescein sodium. Technical note.

The authors have recently performed a fluorescence-guided tumor resection procedure by using high-dose fluorescein sodium without any special surgical microscopes for the intraoperative visualization of glioblastoma multiforme (GBM), and they report on the actual procedure and clinicopathological findings. Thirty-two patients with GBMs underwent tumor resection during which this fluorescence-guided procedure was used. Fluorescein sodium (20 mg/kg) was intravenously injected after dural opening at the craniotomy site. The tumor was stained almost homogeneously yellow and the color was intense enough to be readily perceived for resection. The center of the solid lesion was stained a deep yellow and surrounded by a transition zone that was faintly stained. The colored lesion was clearly distinguishable from the unstained zone outside the GBM, particularly in the white matter. Both the deeply and faintly stained regions included endothelial proliferation and dense tumor cells. In the unstained region, less dense tumor cells were consistently revealed; however, no endothelial proliferation could be seen. Gross-total resection (GTR) was successful in 84.4% of the patients who received an injection of fluorescein sodium, which accounted for 100% of those in whom all the visible yellow color (both the deeply and faintly stained regions) was judged to have been resected during operation. Gross-total resection was performed in 100% of the patients who underwent the fluorescence-guided procedure and assigned to Stage I, a GBM stage in which, as a therapeutic policy, the tumor should be resected as radically as possible. The GTR rates in patients who received fluorescein sodium were significantly higher than those in patients who did not (73 patients with GBMs who underwent tumor resection without the fluorescence-guided procedure). Although the extent of surgery was revealed to be one of the significant and independent prognostic factors for GBM, the fluorescein sodium-guided resection procedure was not a significant or independent prognostic factor in this series. This surgical procedure does not require any special surgical microscopic equipment and is simple, safe, useful, readily accomplished, and universally available for resection of GBMs. Its efficacy simplifies the surgical procedure of navigating the stained lesion from the unstained area to achieve GTR of GBMs, which can be demonstrated on magnetic resonance images.

Adult↗

Peptides, antibodies, and FRET on beads in flow cytometry: A model system using fluoresceinated and biotinylated beta-endorphin.

BACKGROUND: Particulate surfaces such as beads are routinely used as platforms for molecular assembly for fundamental and practical applications in flow cytometry. Molecular assembly is transduced as the direct analysis of fluorescence, or as a result of fluorescence resonance energy transfer. Binding of fluorescent ligands to beads sometimes alters their emission yield relative to the unbound ligands. Characterizing the physical basis of factors that regulate the fluorescence yield of bound fluorophores (on beads) is a necessary step toward their rational use as mediators of numerous fluorescence based applications. METHODS: We have examined the binding between two biotinylated and fluoresceinated beta-endorphin peptides and commercial streptavidin beads using flow cytometric analysis. We have analyzed the assembly between a specific monoclonal antibody and an endorphin peptide in solution using resonance energy transfer and compared the results on beads in flow cytometry using steady-state and time-resolved fluorescence. RESULTS: We have defined conditions for binding biotinylated and fluoresceinated endorphin peptides to beads. These measurements suggest that the peptide structure can influence both the intensity of fluorescence and the mode of peptide binding on the bead surface. We have defined conditions for binding antibody to the bead using biotinylated protein A. We compared and contrasted the interactions between the fluoresceinated endorphin peptide and the rhodamine- labeled antibody. In solution we measure a K(d) of <38 nM by resonance energy transfer and on beads 22 nM. DISCUSSION: Some issues important to the modular assembly of a fluorescence resonance energy transfer (FRET) based sensing scheme have been resolved. The affinity of peptides used herein is a function of their solubility in water, and the emission intensity of the bound species depends on the separation distance between the fluorescein and the biotin moiety. This is due to the quasi-specific quenching interaction between the fluorescein and a proximal binding pocket of streptavidin. Detection of antibodies in solution and on beads either by FRET or capture of fluorescent ligands by dark antibodies subsequently enables the determination of K(d) values, which indicate agreement between solution and flow cytometric determinations.

Antibodies↗

Comparison of contact lens multipurpose solutions by in vitro sodium fluorescein permeability assay.

PURPOSE: This article reports the use of in vitro sodium fluorescein permeability assay to study the effects of various contact lens disinfecting solutions on the integrity of epithelium. METHODS: We compared the sodium fluorescein permeability of monolayer cultures of Madin-Darby canine kidney cells (MDCK) after exposure to ReNu Multi-Purpose Solution, ReNu MultiPlus Multi-Purpose Solution, OPTIFREE Express Multi-Purpose Solution, OPTIFREE Express Solution with Aldox, SOLO-care Solution and Complete Comfort Plus Solution. Additional cell monolayer inserts were prepared for each treatment and were analyzed using a scanning electron microscope. The assay has been used to measure the potential for ocular irritancy of a test solution by evaluating its effect on the cell membranes and tight junctions of a cultured canine kidney epithelial cell monolayer. RESULTS: The sodium fluorescein permeability assay and scanning electron microscopy demonstrated that the two OPTIFREE Express solutions were significantly more damaging to the MDCK epithelium than ReNu and ReNu MultiPlus multipurpose solutions (Bausch & Lomb, Rochester, NY), SOLO-care (CIBA Vision, Duluth, GA) solution, and Complete Comfort Plus (Allergan, Irvine, CA) solution. Cultures treated with the two OPTIFREE Express (Alcon, Ft. Worth, TX) solutions were more permeable to sodium fluorescein than cultures treated with the other multipurpose solutions, because of the loss of tight junctions and cell membrane damage. CONCLUSIONS: This experiment demonstrates that the sodium fluorescein permeability assay can be used to determine the effect that various contact lens disinfecting products have on the integrity of an epithelium in culture.

Animals↗

[Fluorescein fundus angiography of optic nerve head in primary open angle glaucoma and low tension glaucoma].

Fluorescein fundus angiography was performed at angle of 20 degrees in the 58 low tension glaucoma (LTG) eyes (30 cases) and 77 primary open angle glaucoma (POAG) eyes (41 cases) and the relation of the optic nerve head fluorescein changes to visual field disturbances (stage classification of Kosaki) was compared between POAG and LTG groups. The filling defect of fluorescein in the deep area and the decrease in number of superficial capillaries were observed in the optic nerve head. The filling defect area of fluorescein in the optic nerve head corresponding to Bjerrum scotoma was recognized even in the mild visual field disturbance cases of both LTG and POAG. The following findings were noted in both LTG and POAG cases; expansion of the filling defect area and the decrease in number of superficial capillaries in the same area with progression of visual field disturbances. Filling defect area of fluorescein of the optic nerve head accorded with visual field disturbance area in 19 LTG eyes (32.8%) and 61 POAG eyes (79.2%). On the contrary, the filling defect area of the optic nerve head was wider than the visual disturbance area in 37 LTG eyes (63.8%) and 16 POAG eyes (20.8%). These findings suggest that blood circulatory disorders of the optic nerve head occurred earlier in LTG than in POAG and that the development of LTG might be closely associated with the blood circulatory disorders.

Aged↗

[Microscopic quantification of fluorescein distribution in retinas of normal and diabetic rats].

To identify more precisely the site and the nature of the abnormality of the Blood-Retinal Barrier (B.R.B.) in diabetes, quantitative fluorescence microscopy was used to measure time-dependent changes of fluorescence in ocular tissues of normal and diabetic rats, after intravenous fluorescein injection. Fluorescein distribution across the retinal layers was studied in control and streptozotocin diabetic rats at 5, 30 and 60 minutes after dye injection. Fluorescein intensities of choriocapillaris and retina were compared with plasma fluorescein levels. The results show a B.R.B. dysfunction in diabetic rats arising from abnormal leakage of fluorescein into the retina. After 60 minutes there was a greater fluorescence intensity localized to the inner retinal layers, consistent with a probable inhibition or saturation of active transport mechanisms for dye removal through the retinal vessels.

Animals↗

Newly-formed subretinal vessels. Fine structure and fluorescein leakage.

The ultrastructure of experimentally induced newly formed subretinal vessels was correlated with the amount of fluorescein leakage demonstrated by the neovascular membranes during angiography. The membranes that demonstrated leakage contained subretinal vessels with a fenestrated endothelial wall and intermediate interendothelial cell junctions. As these subretinal plexi matured, they stopped demonstrating leakage. This involution process was accompanied by the formation of focal interendothelial tight junctions; however, loss of fenestrations was not observed. The membranes that never demonstrated fluorescein leakage also contained fenestrated subretinal vessels at both early and late stages of development; and their interendothelial junctions showed similar maturation from open to focal tight junctions. Thus all subretinal vessels had "leaky" morphology strongly resembling that of the normal choriocapillaris, whether they demonstrated fluorescein leakage or not. The authors conclude that newly formed subretinal vessels retain the characteristics of the choriocapillaris from which they are believed to proliferate; they have the potential to leak fluorescein at all stages of their development. The absence of fluorescein leakage during angiography cannot always be correlated with the absence of "leaky" morphology.

Animals↗

[Macrophage activation by synthetic peptides. I. Kinetic changes in the transport of fluorescein anions across the plasma membrane of macrophages].

As shown by cytofluorimetric technique, fluorescein anions formed in macrophages due to hydrolysis of fluorescein diacetate (FDA) release into the extracellular medium through the probenecid-inhibitable transport system of organic acids. Technical procedures have been elaborated to record separately the process of FDA hydrolysis characterising the activity of intracellular esterases, and the fluorescein anion transport representing secretion of organic acids by macrophages. It has been established that the tetrapeptide tuftsin stimulates the cell esterase activity without affecting the rate of fluorescein efflux. The peptide KPR (Lys-Pro-Arg) decreases both the esterase activity and the fluorescein anion efflux.

Amino Acid Sequence↗

Resorption of insoluble, heterologous, fluorescein-collagen sponges in sensitized and non-sensitized rats.

Sponges of insoluble bovine collagen were slowly resorbed over a 35-day period when implanted under the back skin of rats. The cellular picture was typical of a mild foreign-body reaction. The reaction to fluorescein-labelled collagen sponges was similar but there was evidence also of a weak immunological response. An acute inflammatory reaction with massive oedema was elicited when fluorescein-labelled collagen sponges were implanted in rats previously sensitized to either fluorescein-collagen or fluorescein-bovine serum albumin. The early invasion by PMN leucocytes subsided after 4 days and caused no observable breakdown of the sponge. The implanted material was rapidly encapsulated by fibrous tissue which was then resorbed along with the sponge between the 7th and 12th day. Macrophages were very active in the sponge at this time, sometimes forming giant cells. Fibroblasts were invading from the periphery with the development of the granulation tissue. The small residue which remained after this time was overrun by granulation tissue and was slowly resorbed up to the 35th day. Throughout the period of study there was only a weak local immunological response after the 28th day. The level of circulating antibodies against the fluorescein hapten was high, but the titre for the antibodies against bovine collagen remained low. The significance of these findings in the pathological destruction of connective tissue is discussed.

Absorption↗

The assessment of skin viability using fluorescein angiography prior to amputation.

Fluorescein angiography was used for the preoperative assessment of skin viability and the determination of the level of amputation in patients with peripheral vascular disease. In twenty-two patients requiring twenty-seven lower-extremity amputations (including five revisions), a retrospective comparison was made between the surgeon's choice of amputation level based on clinical criteria and that based on the fluorescein angiogram. As was evident by the failure of the amputation to heal, the surgeon's prediction was too distal in nine (33 per cent) of twenty-seven amputations and revisions. The assessor of fluorescein angiograms predicted five of these nine failures; therefore, the failure rate could have been reduced to four (15 per cent) of twenty-seven amputations. The amputation level predicted on the basis of the fluorescein angiogram was unnecessarily high in three lower limbs (11 per cent). These three amputations healed at the level chosen by the surgeon, but did so by prolonged secondary healing. Fluorescein angiography is a simple, safe, and useful preoperative bedside technique for the assessment of skin viability and the determination of amputation level in patients with peripheral vascular disease.

Aged↗

[Anaphylactic shock caused by application of fluorescein on the ocular conjunctiva].

OBJECTIVE: Fluorescein is widely used in ophthalmology. Side effects related to fluorescein occur frequently but are usually benign (nausea, vomiting, lipothymia). Severe side effects are rare. We report a case of anaphylactic shock due to local application of fluorescein. CASE REPORT: A 70-year-old woman was treated for ocular conjunctivitis with local application of fluorescein. Cardiac arrest occurred due to anaphylactic shock. Resuscitation was successful. DISCUSSION: The gravity of certain complications related to the use of fluorescein underline the importance of adequate resuscitation material and adapted treatment.

Administration, Topical↗

Comparison of in vivo and in vitro deposition of rhodamine and fluorescein in hair.

A direct differentiation of the internal and external drug-deposition pattern into hair was made using two fluorescent dyes and fluorescence microscopy after systemic administration to mice or external exposure of untreated hair. Mice (23 days old, C57 and Balb/C) were administered either rhodamine or fluorescein intraperitoneally at varied doses on 3 consecutive days of 3 weeks, and hair was sampled 1 week later. Another group was given 10 mg/kg rhodamine or 100 mg/kg fluorescein and sampled at time points from 5 min to 168 hr. The time courses of external deposition of rhodamine and fluorescein into untreated hair were examined after hair was soaked in 0.1 mg/ml solutions at pH 3, pH 6, and pH 9 aqueous buffer or methanol. The hair was then extracted in pH 6 phosphate buffer or methanol for 24 hr. In vivo accumulation was distinguishable as fluorescent bands along the length of the hair for rhodamine and fluorescein. The pattern of in vivo deposition appears to arise from the rapid accumulation within the cortex and medulla, with little deposition evident in the cuticle. Neither phosphate buffer nor methanol washes affected the intensity of fluorescence in the hair. External loading of rhodamine into the hair resulted in staining of the junctions of cuticle scales. This pattern persisted even after 12 hr of solution exposure. Extraction with pH 6 phosphate buffer or methanol did not remove rhodamine. Fluoroscein followed a similar pattern, with maximum fluorescence when hair was loaded in pH 6 100mM phosphate buffer and nominal staining when loaded in pH 9 100 mM Tris buffer or methanol. Soaking the hair in pH 6 buffer, but not methanol, removed some fluorescein. These results demonstrate that compounds in the circulation can rapidly diffuse into the forming cortex and medulla, where rapid associations occur with elongating intermediate filaments specific to the medulla and cortex. These compounds can become significantly occluded within the mature matrix and are resistant to removal in aqueous or methanolic solutions.

Animals↗

Identification of peptide mimotopes for the fluorescein hapten binding of monoclonal antibody B13-DE1.

Using 6mer and 12mer phage peptide libraries three unique phage clones were identified which specifically bind to a monoclonal anti-FITC antibody, B13-DE1. The two 6mer and one 12mer peptide insert sequences are clearly related to each other and contain a high proportion of hydrophobic amino acids. The peptides are bound by the antibody combining site of B13-DE1 probably in a similar manner to FITC and represent therefore true peptidic mimics of the fluorescein hapten. No reactivity of the peptides could be demonstrated with another monoclonal anti-fluorescein antibody or with polyclonal anti-fluorescein antibodies. Immunization of mice with the peptides resulted in the production of antibodies cross-reacting with all peptides but not with fluorescein. The results show that phage peptide libraries can be used to isolate mimotope peptides which can mimic low molecular weight structures seen by a specific antibody and probably other recognition molecules.

Amino Acid Sequence↗

[Intra-arterial fluorescein angiography using ophthalmic artery catheter in an experimental model].

BACKGROUND: For the purpose of retinal angiography sodium fluorescein can be applied oral, intravenously or, via special catheters, intraarterially. In the latter procedure the imaging is different, which will be examined in this paper. There come up aspects, which supplement the possibilities of conventional sequence- or videoangiography and contrast the experimental technique of angiography by temperature-sensitive liposomes. MATERIAL AND METHODS: Intraarterial retinal angiography was carried out on 15 rabbits through a microcatheter and fluorescein was applied in different quantities and concentrations. RESULTS: Because of the direct inflow to the retina, the resulting images had more contrast and interference due to recirculating fluorescein was nearly excluded. With increased perfusion pressure, functional tests of circulation were possible. By administering small amounts of fluorescein 10% (0.01-0.02 ml/min) via the catheter, continuous perfusion provided continuous presentation of hemodynamics, by making visible retinal pulsation. CONCLUSIONS: The intraarterial fluorescence-angiography offers a new possibility for evaluating retinal circulation under increased pressure and for analysis of the retinal pulse wave. The procedure gets a clinical perspective by combined therapeutical application.

Animals↗

[Detection of cystoid macular edema with orally administered fluorescein].

To detect cystoid macular edema after extracapsular cataract extraction, the authors used indirect ophthalmoscopy after oral application of fluorescein, rather than intravenous fluorescein angiography. The patients drank 10-20 ml 10% fluorescein sodium in 250 ml orange juice. Ophthalmoscopy was performed 30-45 minutes later using an exciter filter. Twenty-five patients with a tentative clinical diagnosis of cystoid macular edema were examined in this way. In six of them a manifest edema was detected. The results were confirmed by intravenous fluorescein angiography.

Administration, Oral↗

The safety of intravenous fluorescein administration.

Intravenous fluorescein is frequently used to assess tissue perfusion and predict flap viability, although its safety has recently been questioned due to cardiovascular side effects. Vital signs of 50 patients who received fluorescein were monitored by anesthesiologist to assess flap viability. Blood pressure readings were recorded at 5-minute intervals for at least 1 hour before and after fluorescein administration. Repeated measure analysis of variance was performed to determine any significant sustained (greater than or equal to 30 minutes) or transient (less than or equal to 15 minutes) differences in pressure changes after fluorescein administration. No significant (p less than or equal to 0.1) differences in pressure were noted for any identifiable group of patients. Minor reactions included transient nausea with no vomiting (5), sustained blood pressure increases of greater than 10% preadministration values (9), transient pressure drops of greater than 10% (10), and sustained pressure drops of greater than 10% (4). These 4 patients responded to increased fluid therapy without need for pressor agents.

Adult↗