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At least 235 records · Page 13Linked to original sources
PubMed1998

Fluorescein-induced allergic reaction.

BACKGROUND: Adverse reactions following intravenous sodium fluorescein are very unusual and their mechanism is still uncertain. We report the case of a patient who suffered an adverse reaction during a fluorescein ocular angiography. Positive allergy tests to fluorescein suggest an IgE-mediated mechanism. OBJECTIVE: Report the allergy evaluation performed in a patient who suffered an adverse reaction during an intravenous fluorescein administration. METHODS: We selected the case of a patient who suffered dizziness, diaphoresis, generalized pallor, nausea, sphincter relaxation, hypotension, and intense malaise during a fluorescein ocular angiography and compared the results to other nonreactive subjects. Allergy evaluation: Prick and intradermal skin tests and serial determinations of serum tryptase were performed on the patient and four control subjects who underwent and tolerated the same procedure as well as on a patient who developed an intense vagal reaction during blood extraction. RESULTS: Positive skin tests and dramatic increase of serum tryptase (67U/I) were observed in our patient. The rest of the patients had negative skin tests and did not have any variation in their serum tryptase. CONCLUSIONS: An IgE-mediated mechanism is suggested as responsible for this adverse reaction. We recommend that a complete allergy evaluation should be performed in all patients who have adverse reactions to fluorescein in order to differentiate true allergic reactions from other types of reactions.

Aged↗
PubMed1985

Labeling of the cytoplasmic domain of the influenza virus hemagglutinin with fluorescein reveals sites of interaction with membrane lipid bilayers.

The hemagglutinin (HA) glycoprotein of influenza virus was labeled in its cytoplasmic domain with fluorescein. Reactive amino groups in the external domain were blocked by modification of the intact virus with the membrane-impermeable reagent isethionyl acetimidate. The HA was then solubilized with the detergent octyl glucoside, and the single lysine in the cytoplasmic domain was reacted with fluorescein isothiocyanate. This protocol resulted in the incorporation of 1.3 mol of fluorescein/mol of HA. Using a virus strain lacking lysine in the cytoplasmic domain of HA, it was determined that 0.47 mol of fluorescein/mol of HA was located at an additional site(s). The fluorescein groups at both sites exist in an environment of reduced polarity as shown by a shift in excitation and emission maxima and a shift in the pKa of the fluorescein groups. The fluorescence polarization and the pKa of the fluorescein groups were greater when the HA was incorporated into liposomes than when in detergent solution. These data indicate that the fluorescein groups interact directly with the lipid bilayer, probably in the phospholipid head-group region. The fluorescence properties of the labeled HA were not responsive to the gel to liquid-crystal phase transition in the lipid bilayer. These results indicate that the boundary between the cytoplasmic domain and the hydrophobic sequence that anchors the protein to the lipid bilayer is located in the head-group region of the bilayer.

Electrophoresis, Polyacrylamide Gel↗
PubMed1994

The effect of fluorescein volume on lacrimal outflow transit time.

The Jones primary dye test is a commonly used test of lacrimal outflow. Some clinicians, however, find it of limited practical significance because of variable outcome and relatively low sensitivity in documenting normal lacrimal excretory function. We hypothesized that an important variable affecting the transit time may be the volume of fluorescein used in the primary dye test. To accurately determine the exact time from insertion of dye into the eye to its appearance in the nose, using a rigid nasal endoscope, we directly visualized the dye as it appeared at the ostium of the nasolacrimal duct. Fifty nasolacrimal outflow systems were examined in 25 normal volunteers. The fluorescein dye transit time was determined using a single drop of fluorescein on one side and multiple drops of fluorescein on the other side. Using a single drop of fluorescein, the median dye transit time was 8 min, compared to 1.4 min using multiple drops. These results suggest that the volume of fluorescein used may be an important factor affecting variability in the outcome of the primary dye test.

Adult↗
PubMed1994

Probenecid inhibition of the outward transport of fluorescein across the human blood-retina barrier.

The effect of probenecid on the outward transport of fluorescein from vitreous to blood was studied in 13 insulin-dependent diabetic patients with background retinopathy in a randomised double-masked placebo controlled cross-over study. Fluorescein and fluorescein glucuronide was separated in the vitreous and in plasma by differential spectrofluorometry. The data for fluorescein were analysed using a simplified mathematical model of the eye. The inward permeability was estimated from data obtained 1 h after injection and the outward transport from data obtained 7 h after injection. During placebo treatment the mean inward permeability was 3.75 x 10(-7) cm/sec and the mean outward permeability was 2.25 x 10(-5) cm/sec. During probenecid treatment the mean inward permeability was 3.34 x 10(-7) cm/sec and the mean outward permeability was 1.44 x 10(-5) cm/sec. Thus, we found no significant change in inward permeability (p = 0.5879), whereas a significant decrease of 36% was found in the outward permeability of fluorescein (p = 0.0171). The demonstration that the outward permeability, which is more than 100-fold higher than the inward permeability in the healthy eye, is significantly decreased by probenecid, demonstrates that active transport is involved in movement of fluorescein across the blood-retina barrier from the vitreous to the plasma.

Adult↗
PubMed1996

Modification of the Mycobacterium bovis extracellular protein MPB70 with fluorescein for rapid detection of specific serum antibodies by fluorescence polarization.

The principle of fluorescence polarization described by Perrin (F. Perrin, J. Phys. Radium 7:390-401, 1926) was applied to the development of a novel assay that used fluorescein-labeled Mycobacterium bovis secretory protein MPB70 for rapid detection of anti-MPB70 antibodies in selected sera from three M. bovis-infected species (elk, Ilama, and bison). Labeling of purified MPB70 with fluorescein isothiocyanate resulted in the incorporation of 0.96 +/- 0.08 (mean +/- standard deviation; n = 3) fluorescein group per MPB70 molecule. The labeled protein fluoresced strongly with an emission maximum at 518 nm when excited with light of a wavelength near 493 nm, and its immunoreactivity with anti-MPB70 monoclonal antibody 4C3/17 was not altered by modification with fluorescein. The fluorescence polarization assay protocol was optimized for analysis of serum samples by incorporating into the assay buffer 0.05% lithium dodecyl sulfate, which prevents the occurrence of some nonspecific interactions. Sera from M. bovis-infected animals, selected on the basis of exhibiting the presence of anti-MPB70 antibodies, as detected by enzyme-linked immunosorbent assay (ELISA), reacted with fluorescein-labeled MPB70, resulting in an increase in polarization of up to 330 milli-polarization units, in contrast to the values for noninfected sera (167 to 178 mP), which were close to that obtained in the absence of specific antibodies (164.7 +/- 3.3 mP; n = 6). These results demonstrated the feasibility of using fluorescein-labeled MPB70 to detect anti-MPB70 antibodies by fluorescence polarization and suggested that the assay described here can be an alternative to ELISA or other antibody assay systems. The advantages of this original methodology and its general applicability to the diagnosis of infectious diseases are discussed.

Animals↗
PubMedDate not supplied

Correlation between the uptake of sodium fluorescein in the tissue and xenon-133 clearance and laser Doppler fluxmetry in measuring changes in skin circulation.

We have measured the plantar forefoot skin circulation by the uptake of sodium fluorescein (fluorescein flowmetry), 133Xe clearance and laser Doppler fluxmetry in 24 healthy subjects and correlated measurements under basal conditions and after provocation by alcohol intake and application of external heat. To assess the change in skin circulation between the initial measurement at rest and the second measurement after provocation, the coefficient of correlation (r) of the fluorescein flowmetry to the fast slope of the 133Xe elimination curve was 0.46 (p < 0.05), to the slow slope of the 133Xe elimination curve 0.66 (p < 0.001) and to laser Doppler fluxmetry 0.86 (p < 0.001). The coefficient of correlation (r) of the fluorescence appearance time to fluorescein flowmetry was 0.65 (p < 0.001), to the fast slope of the 133Xe elimination curve 0.14 (p = 0.42), to the slow slope of the 133Xe elimination curve 0.47 (p < 0.05) and to laser Doppler fluxmetry 0.63 (p < 0.001). The uptake of sodium fluorescein as measured by fluorescein fluxmetry correlates well with both 133Xe clearance and laser Doppler fluxmetry in assessing a change in skin circulation in healthy humans. The fluorescence appearance time also correlates to the slow slope of the 133Xe elimination curve and to laser Doppler fluxmetry though to a lesser extent.

Adult↗
PubMed1991

Goldmann tonometry and fluorescein solution: a way to avoid contact lens staining.

Topical instillation of fluorescein during standard Goldmann tonometry may cause subsequent contact lens staining. We evaluated a method of Goldmann tonometry that uses only a small amount of fluorescein. In this experimental technique, the fluorescein is applied only to the tip of the applanation cone with fluorescein-coated tissue paper. Thirty patients had their intraocular pressures (IOPs) determined by this method. The IOP measurements were then repeated on the same eyes after instillation of fluorescein directly onto their eyes. In addition, 20 soft contact lens wearers had their IOPs determined by the experimental method, with contact lenses fitted immediately after the measurements. There was no statistically significant difference between the IOPs measured by the standard technique and by the experimental method. In addition, no fluorescein staining was detected in the 20 soft contact lenses examined. Our results suggest that the proposed method is accurate and useful in determining IOP prior to soft contact lens fitting.

Contact Lenses, Hydrophilic↗
PubMed1990

Clearance of fluorescein incorporated into microspheres from the cornea and aqueous after subconjunctival injection.

The clearance of sodium fluorescein from the cornea and aqueous humor of albino rabbits was quantitated after subconjunctival injection of fluorescein entrapped in lactide/glycolide (group 1) and lactide (group 2) microspheres. Seven hours after injection, approximately equal concentrations of fluorescein were measured in both groups in the cornea and aqueous. Fluorescein concentrations in the cornea were more than three times those found in the aqueous. Fluorescein concentrations in both groups decreased at 22 hours, and remained constant at 46 hours. Corneal fluorescein levels in group 2 were slightly higher than in group 1 at 22 and 46 hours. All eyes showed conjunctival inflammatory reaction at the injection sites after 6 days. One eye showed conjunctival necrosis at the injection site after 13 days.

Animals↗
PubMed1990

Effect of fluorescein on the electrical potential difference across isolated rabbit corneal endothelium.

The authors investigated whether fluorescein sodium affects the in vitro endothelial function of rabbit corneas. As an index of this function, the transendothelial electrical potential difference (TEPD) was used. The TEPD in a balanced salts and glucose (BSG) control solution increased for the first 30 min and then decayed slowly, reaching about 60% of its original value after 5 hr. When a BSG solution containing 5 micrograms/ml of fluorescein sodium was used, the TEPD time course was similar to the control solution. Since this fluorescein sodium concentration is about sevenfold higher than that seen in the anterior chamber of ocular patients, these results reassure users that no toxic effect of fluorescein is discernible at concentrations relevant to ophthalmic practice. With a fluorescein sodium concentration of 500 micrograms/ml, the TEPD decreased below control values after 4 hr of exposure, but such a concentration is approximately 5000-fold higher than that seen in the anterior chamber of patients. The adverse effect of fluorescein on TEPD is probably irrelevant for standard systemic clinical use.

Analysis of Variance↗
PubMedDate not supplied

Reaction of fluorescein isothiocyanate with thiol and amino groups of sarcoplasmic ATPase.

Several model compounds containing thiol and/or amino groups (mercaptoethanol, glutathione, cysteine, ethanolamine, glycine) were studied with respect to their reactivity towards fluorescein isothiocyanate (followed spectrophotometrically at 504 and 412 nm), stability of product and long-wave absorption maximum of the fluorescein residue attached. Thiol groups reacted by far more readily than amino groups. A specific effect was observed with cysteine, indicating an intramolecular transfer of the fluorescein residue from SH to NH2. With sarcoplasmic vesicles both types of reactions were observed. The ratio of products, which can be distinguished by their different stabilities and absorption spectra, depended on the absence or presence of detergents. While with native vesicles the NH2 reaction predominated, with vesicles solubilized with sodium dodecylsulfate, octaethyleneglycol mono-n-dodecyl ether or 1-0-tetradecyl-propanediol-(1,3)-3-phosphorylcholine the SH reaction became prevailing. Already 0.35 mg sodium dodecylsulfate per mg protein were sufficient to give rise to dithiourethane formation exclusively. Excess fluorescein isothiocyanate reacted with several thiol groups of dodecylsulfate-solubilized vesicles. In the presence of ATP binding of fluorescein isothiocyanate to native vesicles was significantly reduced. Total blockage of the vesicular SH groups with N-ethyl-maleimide led to preparations that reacted with fluorescein isothiocyanate much more slowly, compared to native vesicles. Octaethyleneglycol mono-n-dodecyl ether or 1-0-tetradecyl-propanediol-(1,3)-3-phosphorylcholine in the assay accelerated the thioureide formation from N-ethylmaleimide modified vesicles, whereas sodium dodecylsulfate prevented it almost completely. Our results support the suggestion that one or several thiol groups in vicinity of the highly reactive lysyl residue might play a role in the fast specific reaction, which is only observed with intact native vesicles.

Adenosine Triphosphatases↗
PubMed1987

The ATP-binding site of the erythrocyte membrane Ca2+ pump. Amino acid sequence of the fluorescein isothiocyanate-reactive region.

The erythrocyte plasma membrane Ca2+-pumping ATPase is known to form an acyl-phosphate catalytic intermediate, but there is otherwise little structural information linking it to the other mammalian ion-pumping ATPases which also form phosphorylated intermediates (the Na+, K+-ATPase of plasma membranes, the Ca2+-ATPase of sarcoplasmic reticulum, and the H+, K+-ATPase of gastric mucosa). We show here that this enzyme possesses a fluorescein isothiocyanate-reactive region similar to that possessed by these other ATPases. Low concentrations (10 microM) of fluorescein isothiocyanate inhibit the ATPase activity of this pump, and this inhibition is prevented by 4 mM ATP. ATP also inhibits the reaction of fluorescein isothiocyanate with a single amino acid residue on the 138-kDa polypeptide chain. A tryptic fragment containing the fluorescein-conjugated residue was isolated by high pressure liquid chromatography. The sequence of this peptide was determined to be NH2-Met1-Tyr2-Ser3-Lys4-Gly5-Ala6-Ser7-Glu8++ +-Ile9-Ile10-Leu11-Arg12-COOH; fluorescein isothiocyanate reacts with the lysine residue. The identities of residues 4-8 are the same as those in a sequence common to the other ATPases mentioned above, except that serine-7 of this sequence is changed to a proline in those ATPases. This substitution, sometimes not considered a homologous one, is not expected to have a major effect on the secondary structure or polarity of this region. Outside of this 5-residue core region of the fluorescein isothiocyanate-reactive site, the homologies among the different ion-pumping ATPases are limited.

Adenosine Triphosphatases↗
PubMed1986

Transport of fluorescein monoglucuronide out of the vitreous.

The transport of fluorescein monoglucuronide, a fluorescent metabolite of fluorescein, from the vitreous was studied. Ten microliter of 1 mM fluorescein monoglucuronide or fluorescein solution was injected into the rabbit vitreous body, and the vitreous concentration was measured every 2 hr. The rate of loss from the vitreous was 0.066 +/- 0.012 (SD)/hour for fluorescein monoglucuronide and 0.22 +/- 0.029/hour for fluorescein. Systemically administered probenecid caused a statistically significant reduction in the loss from the vitreous of each of them.

Animals↗
PubMed1985

Binding of fluorescein monoglucuronide to human serum albumin.

The binding to human albumin of fluorescein monoglucuronide, a fluorescent metabolite of fluorescein, was studied using two methods: pressure dialysis and fluorescence polarization. Both methods indicated that fluorescein monoglucuronide binds to human albumin more loosely than fluorescein. The free fraction in human plasma estimated from the dissociation constant and the number of binding sites was in a range from 31 to 37%. Fluorescence of fluorescein was significantly quenched by the albumin binding, but fluorescence of fluorescein monoglucuronide was not affected by albumin. The relative molar intensity of fluorescence between these fluorophores varied from 3.2 to 37.3, depending on the excitation wavelength.

Fluorescein↗
PubMed1984

Measurement of retinal permeability to sodium fluorescein in vitro.

Fluorescein permeabilities of isolated dog retinal pigment epithelium (RPE)-choroid and sensory retina were measured individually. Retina to choroid (outward) permeability of sodium fluorescein was significantly larger than choroid to retina (inward) permeability at RPE-choroid under both open- and short-circuit conditions. Outward permeability was decreased by the addition of 10(-3) M KCN and of 10(-4) M probeneside but was not affected by 10(-6) M ouabain. These drugs decreased transepithelial potential and short-circuit current. No directional difference of fluorescein permeability for sensory retina was found. Active transport of fluorescein across RPE from retina to choroid is suggested. Fluorescein permeability of sensory retina was larger than inward but less than outward permeability of RPE-choroid. The result indicates that the sensory retina acts as a diffusion barrier for sodium fluorescein.

Animals↗
PubMed1983

Some aspects of the pharmacokinetics of fluorescein in normal and in diabetic subjects.

A method for measuring the free fraction of fluorescein in plasma by ultrafiltration is tested. The coefficient of variation is 3%. Changes in pH and temperature from in vivo conditions at 37 degrees C to in vitro conditions are slight (less than 6%) and tend to minimize each other. To study the pharmacokinetics of fluorescein, 25 control subjects and 38 insulin-treated diabetics were examined after an intravenous injection of sodium fluorescein, 17 mg/kg body weight. 5, 45 and 120 min later, free fluorescein was significantly lower in the diabetics (5 min: 2.4 +/- 0.5 vs. 2.1 +/- 1.0, 45 min: 0.62 +/- 0.13 vs. 0.52 +/- 0.14, 120 min: 0.27 +/- 0.07 vs. 0.17 +/- 0.07 X 10(-5) g/ml, p less than 0.01 (mean +/- SD)). The renal excretion of fluorescein is reflected in a positive relation between serum creatinine and total plasma fluorescein at 45 and 120 minutes in the group of diabetics (Spearmans rho = 0.52, p = 0.04 and 0.53, p = 0.08, respectively).

Blood Glucose↗
PubMed1993

Sodium fluorescein accumulation in cultured cells.

The mechanism of intracellular fluorescein accumulation was investigated by studying fluorescein accumulation kinetics in individual cells in culture. The experiments were done with K562 human erythroleukemia cell culture and a primary culture of human embryonic skin fibroblasts. Various experimental conditions were used by varying pH and ion composition of the external media, and/or temperature. All the experimental results obtained are in support of the proposed theoretical model describing fluorescein accumulation in cells along the pH gradient. In addition, we could show that fluorescein molecules are bound to some intracellular macromolecules. Fluorescein accumulation in the cells studied does not depend on their malignant nature. It is therefore reasonable to conclude that fluorescein accumulation observed in clinical investigations of human gastric cancer is governed by the ph gradient between the cells and the extracellular fluid; this gradient is much greater in the tumor than in normal tissues.

Biological Transport, Active↗
PubMed1995

Acute toxicity of fluorescein to turbot (Scophthalmus maximus).

Some land-based marine fish-farms situated on the Atlantic coastline of France use high volumes of underground sea water. Studies of the available quantities and movements of this underground resource became necessary, using fluorescent dyes such as fluorescein. As fluorescein may reach reared fish, it became important to assess its toxicity to fish. Acute fluorescein toxicity to turbot (Scophthalmus maximus) was investigated by exposing fish to different fluorescein concentrations (0.5, 0.7, 0.9, 1.1 and 1.3 milligrams) at 14.0 C for 24, 48 or 96 h. The lethal concentration inducing 50% fish mortality (LC50) was 997.1 +/- 11.4 mg/l (mean +/- standard deviation) after a 24, 48 or 96 h exposure. Toxicity affected the central nervous system. Early postmortem findings were a brown-green coloring of some tissues and encephalon congestion. The fluorescein LC50 was much higher than the recommended concentration in field applications (1 mg/l), indicating that fluorescein toxicity to turbot will not be expected when used at the recommended concentration.

Animals↗
PubMed1981

Fluorescein angiography. Demonstration of flow pattern of anterior ciliary arteries.

With fluorescein angiography of the episcleral region at two frames per second, the wide, tortuous vessels perforating the sclera near the limbus were shown to first fill with fluorescein at an average of 19 s after intravenous injection of fluorescein. These perforating vessels should be called the anterior ciliary arteries because they are the first vessels to fill with fluorescein, fill at the same time the iris fills, give out branches, have higher pressure compared with veins, and show pulsations when the pressure is applied to them. In addition in most cases, distinctly different veins that fill laminarly or fully were seen. The first filling with fluorescein occurred at the scleral perforation point and proceeded posteriorly toward the recti muscles. This finding is in contrast to the accepted concept that the anterior ciliary arteries, as the continuation of the muscular arteries, as the continuation of the muscular arteries, fill from the region of the recti muscles. No significant differences were observed in the fluorescein angiographic patterns of the episcleral vessels between normal eyes, ocular hypertensive eyes, and eyes with primary open angle glaucomas.

Adult↗