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PubMed1982

Binding of fluorescein and carboxyfluorescein by normal and glycosylated human serum proteins.

The binding of fluorescein and 6-carboxyfluorescein by normal, diabetic and in vitro glycosylated human serum proteins was analyzed by absorption and fluorescence spectroscopy, gel filtration and equilibrium dialysis. The absorption spectra of bound fluorochromes showed red shifts and hypochromic changes, and fluorochrome fluorescence was reduced by serum proteins. Bio-gel P-6 and Sephadex G-200 gel filtration in solvents containing free fluorochrome demonstrated that fluorescein and carboxyfluorescein were bound by serum proteins of varying molecular weights and/or diffusion rates. Equilibrium dialysis at 37 degrees C showed that human sera contained 3.5 +/- (SD) 0.4 X 10(-3)M of fluorescein and carboxyfluorescein binding sites with an average association constant of 3.9 +/- 0.2 X 10(-3)M-1. Undiluted serum proteins bound 93% of the fluorochrome at a total concentration of 2 X 10(-4)M or less. Glycosylation of serum proteins in vivo or in vitro did not change the concentration-dependent or pH-dependent binding of fluorescein or carboxyfluorescein.

Blood Proteins↗
PubMed1991

Multiple releasable fluorescein labels for immunoassay: the principle illustrated by an immunoassay for antibodies to the human immunodeficiency virus.

Attempts to increase the sensitivity of fluorescein-based fluorescence immunoassays by using multiple labelling have generally been unsuccessful because of concentration quenching. We have labelled antibodies to human immunoglobulin G with multiple fluorescein fluorophores attached by means of a disulphide linkage: this linkage can be rapidly and easily broken by treatment with dithiothreitol, allowing fluorescein to be released from the antibody and measured in free solution. Application of this technique to a fluorescence labelled immunosorbent assay for antibodies to the human immunodeficiency virus gave an approximately 20-fold increase in signal compared with an equivalent assay using fluorescein isothiocyanate.

Acquired Immunodeficiency Syndrome↗
PubMed1978

Fluorescence properties of free and protein bound fluorescein dyes. I. Macrospectrofluorometric measurements.

Excitation and emission properties of fluorescein derivatives were studied macrofluorometrically. Measurements were performed with solutions of various concentrations (0.07-100 microgram/ml) of free sodium fluorescein prepared from fluorescein diacetate (FDA), fluorescein isothiocyanate (FITC) and FITC bound to rabbit gamma-globulin. Both excitation and emission spectra as well as fluorescence intensities at constant excitation/emission wavelengths (496/515 nm) were recorded. The findings indicate that (1) FDA gives about twice the fluorescence intensity compared to equal concentrations of FITC. (2) The fluorescence properties of FITC upon excitation with blue light (lambda = 496 nm) are only slightly altered by the conjugation to rabbit gamma-globulin. (3) Considerable quenching due to conjugation could, however, be shown to occur upon UV excitation (lambda = 340 nm). (4) Fluorescence emission excited by visible blue light (496 nm) increases linearly to dye concentration in a range of 0.07-2.5 microgram/ml. Beginning at 5 microgram/ml (10-(5) M/1) all three compounds show a sharp decrease of fluorescence intensity with further increasing concentration. Practical aspects of these data for the immunofluorescence method are discussed.

Animals↗
PubMed2001

Diabetic retinopathy in childhood: long-term follow-up by fluorescein angiography beginning in the first months of disease.

BACKGROUND: Little is known about minimal retinal lesions occurring in the first months of disease in children with type 1 diabetes mellitus (DM). OBJECTIVE: To detect any early retinal change and to evaluate its progression in children diagnosed with type 1 DM. PATIENTS: From 1979 to 1997 we examined by fluorescein angiography at diagnosis or within 15 months from the onset of DM 130 young patients with type 1 DM (mean age at diagnosis 10.08 +/- 2.62 yr). In 112 patients follow-up by fluorescein angiography was performed every 1.26 years with a mean of 5.41 fluorescein angiographies/patient. METHODS: The stage of retinopathy was graded to detect minimal lesions. We also considered sex, pubertal stage, HLA, family history of DM, disease duration and HbA1c levels. RESULTS: At first examination, 14 out of 127 (11%) readable angiographies showed minimal retinal changes. There was no statistically significant difference between the patients with or without lesions for all parameters considered. The 112 patients examined during follow-up were divided as follows: Group A: no retinopathy at first examination; Group A1: no retinopathy during follow-up; Group A2: retinal changes during follow-up; Group B: retinal changes at the first examination. Mean HbA1c value evaluated during the whole follow-up was lower in group A1 than in group A2. HbA1c levels at onset of the disease were significantly different in the three groups: in group A1 it was lower than in group A2 and in group B. CONCLUSIONS: The presence of early lesions in the first year of disease in 11% of patients is probably due to the method of examination, which may detect even minimal retinal changes. This may be correlated to the acute metabolic failure present at the onset of disease. The prolonged follow-up seems to demonstrate that the early changes are not necessarily a negative prognostic factor in the evolution of diabetic retinopathy. We confirm that duration of DM and metabolic control are the main factors influencing the course of retinopathy in these young patients. Early fluorescein angiography is not particularly useful in the management of children with DM.

Adolescent↗
PubMed1978

Fluorescein fundus angiography of stroke-prone SHR.

The fluorescein fundus angiography was performed on SHRSP, SHR, and NR. The following results were obtained. 1. No expravasation of fluorescein from retinal vessels of SHR and NR was observed at any phase of circulation. 2. The extravasation of fluorescein from retinal arterioles and peripapillary capillary of SHRSP of post-hypertensive stage was seen at arterial phase of circulation. These extravasation of fluorescein coincided with the initial stage of stroke incidence.

Animals↗
PubMed2003

The thiourea group modulates the fluorescence emission decay of fluorescein-labeled molecules.

We have investigated the spectral properties and emission characteristics of fluorescein-5-thiocarbamoyl-N,N'-caproate (FITC-ACA) to examine the origin of the complex emission decay often observed in fluorescein-labeled molecules. The covalent attachment of fluorescein to epsilon-amino-n-caproic acid does not perturb the prototropic transitions of the chromophore or the general fluorescence characteristics of the various prototropic forms. However, both the monoanion and dianion forms of FITC-ACA are quenched relative to free fluorescein and exhibit a complex emission decay that is described by two discrete lifetimes. The thiourea group that links the chromophore to the caproic acid is shown to modulate the emission properties of the FITC-ACA. We show that the emission decay can also be analyzed using the asymmetric distribution model of Alcala et al. In this analysis, the tauL and tauu parameters that represent the lower and upper lifetime limits of the distribution reflect the quenched (0 ns) and unquenched lifetimes, respectively. The beta parameter that describes the distribution of lifetimes between the two limiting states can be related to the quenching efficiency of the thiourea group and to the structure and dynamics of the FITC-ACA molecule.

Fluorescein↗
PubMed1977

Acute toxicity testing of erythrosine and sodium fluorescein in mice and rats.

Erythrosine and sodium fluorescein, two colors used as a dental plaque disclosing agents, have similar chemical structures differing only in that erythrosine has four iodine atoms in the molecule while sodium fluorescein has no iodine. A comparative toxicological profile was made on both compounds employing oral dose ranges and acute oral toxicity tests in mice and rats. The results show erythrosine to be approximately twice as toxic as sodium fluorescein with LD50 values of 2558 +/- 1.35 mg/kg in mice and 2891 +/- 1.02 mg/kg in rats for erythrosine and 4738 +/- 1.23 mg/kg in mice and 6721 +/- 1.26 mg/kg in rats for sodium fluorescein. The major toxic manifestations of both compounds were those indicative of central nervous system depression.

Administration, Oral↗
PubMed1998

Fluorescein and indocyanine green angiography in vascular chorioretinal diseases.

Fluorescein angiography allows visualization of blood flow in retinal and choroidal tissues, permitting diagnostic support in many ocular diseases. Particularly, fluorescein angiography has become a very important tool in the study and treatment of chorioretinal diseases. Because of the limitations of fluorescein angiography in imaging the choroidal circulation and associated pathologies, investigators have searched for alternative dyes to improve choroidal angiography, the most promising of which has been indocyanine green dye. The usefulness of indocyanine green angiography to aid in the diagnosis and treatment of a variety of chorioretinal diseases was reported during the last years. The goal of this article is to make an overview on the most frequent Fluorescein and ICGA patterns of vascular diseases of the chorioretina.

Choroid Diseases↗
PubMed1978

Spectrum of complications in the use of intrathecal fluorescein.

The authors describe a case in which 0.5 cc of 5% fluorescein diluted in 10 cc of cerebrospinal fluid (CSF) was injected at the L4-5 level for evaluation of nasal CSF leakage. Within minutes, tone increased in lower extremities accompanied by knee and ankle clonus and subjective numbness up to the waist. Non-preserved saline irrigation of the lumbar CSF was administered until it became clear, and the patient's head was elevated to retard the developing symptomatology. Although a transient temperature elevation was observed with negative CSF cultures, all signs and symptoms cleared within 48 hours. In a survey of the members of the Americal Association of Neurological Surgeons regarding frequency of use and complications stemming from intrathecal fluorescein, the response rate was 58.3% (1111) of the 1907 members, of which 6.8% (76) had used intrathecal fluorescein, and among those, 25% (19 of the 76) had observed complications involving lower extremity weakness, numbness, generalized seizure activity, opisthotonos, and cranial nerve deficit. No complications were permanent. The authors recommend caution if intrathecal fluorescein must be used. Means should be available to clear the CSF of the agent and elevate the head if complications arise.

Adolescent↗
PubMed1999

Sodium fluorescein influence on the hemorheological profile of non-insulin dependent diabetes mellitus patients.

Sodium fluorescein angiography is a widely used technology in ophthalmology, which allows us to visualise the chorioretinal microcirculation. Previous reports showed a prolongation of the retinal circulation time along with erythrocyte hyperaggregation and a decrease of erythrocyte acetylcholinesterase activity and a possible interference with the erythrocyte's membrane fluidity. The aim of the present work is to investigate the influence of sodium fluorescein on the hemorheological profile of a group of 23 non-insulin dependent diabetes mellitus (NIDDM) patients undergoing routine retinal angiography. Thirty minutes after the endovenous administration of the fluorescein there was: (I) an increase of whole blood viscosity (p = 0.015), erythrocyte elongation index (EEI, p < 0.05), whole blood pH (p < 0.001), methemoglobin (p < 0.001) and carboxyhemoglobin (p < 0.001) concentrations; (II) no variation of plasma osmolality and erythrocyte aggregation index (EAI); (III) a decrease of the erythrocyte acetylcholinesterase activity, p < 001; (IV) no variation in membrane lipid fluidity, although 1,6-diphenyl-1,3,5-hexatriene (DPH) correlated directly with the EEI, while 1,4-trimethyl-phenyl-1,3,5-hexatriene (TMA-DPH) and EAI correlated inversely, suggesting that the decreasing EEI (lower erythrocyte deformablity) might be associated with an increased rigidity of the external polar region and fluidification of the hydrophobic region of the erythrocyte membrane, with an increasing EAI. In conclusion, the endovenous administration of sodium fluorescein in NIDDM patients during the retinal angiography procedure interferes with the erythrocyte membrane and possibly with the microcirculatory blood flow.

Angiography↗
PubMed1999

Tear fluid gelatinase B activity correlates with IL-1alpha concentration and fluorescein clearance in ocular rosacea.

PURPOSE: To correlate tear fluorescein clearance with interleukin-1alpha (IL-1alpha) concentration and gelatinase B (matrix metalloproteinase [MMP]-9) activity in the tear fluid of patients with ocular rosacea and normal control subjects. METHODS: Gelatinase activity was evaluated by gelatin zymography in tear fluid obtained from 13 patients with ocular rosacea (including 1 patient with recurrent epithelial erosion, 2 with recurrent peripheral corneal infiltrates and vascularization, and 2 patients with epithelial basement membrane dystrophy) and 13 normal subjects with normal aqueous tear production and no irritation symptoms. Tear fluorescein clearance was evaluated by measuring fluorescence in tear fluid collected from the inferior meniscus 15 minutes after instillation of 5 microl of 2% Na-fluorescein with a CytoFluor II fluorometer. Pro-MMP-9 and IL-1alpha concentrations in the tear fluid were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: Compared with normal control subjects, patients with ocular rosacea had a greater delay of tear fluorescein clearance (P < 0.001), a higher tear IL-1alpha concentration (P < 0.001), and a greater pro-gelatinase B (92 kDa) activity (P < 0.001) in their tear fluid. The 84-kDa active form of gelatinase B was observed in 46% of the rosacea tear samples and none of the controls. The zymographic results were confirmed by ELISA that showed a significantly greater concentration of pro-MMP-9 (92 kDa) in the tear fluid of rosacea patients than controls. Delayed tear clearance was correlated with elevated tear IL-1alpha concentration (p=0.67, P < 0.001) and increased tear gelatinase B activity (p=0.84, P < 0.001). Tear IL-1alpha concentration was correlated with tear gelatinase B activity (p=0.58, P < 0.002). CONCLUSIONS: Gelatinase B (MMP-9) activity is greater in patients with ocular rosacea than in normal eyes. The majority of this activity is due to 92-kDa proform of this enzyme. This activity is correlated with delayed tear clearance and tear fluid concentration of interleukin-1alpha, a proinflammatory cytokine that has been reported to stimulate gelatinase B production. Elevated gelatinase B activity in ocular rosacea may be involved in the pathogenesis of the irritation symptoms, recurrent epithelial erosions, vascularization, and epithelial basement membrane dystrophy that develops in the corneas of patients with this condition.

Adult↗
PubMed2000

Evidence for mild blue-yellow colour vision deficits immediately following fluorescein angiography.

AIMS: We have investigated the short term effects of fluorescein angiography on the blue-yellow, red-green, and luminance contrast sensitivity of patients with early age-related macular degeneration (ARMD). METHODS: Nine ARMD patients with no exudative complications and a visual acuity of 20/60 or better in the tested eye were selected. Cardinal colour directions for the isolation of the red-green, blue-yellow and achromatic (luminance) visual mechanisms were determined for each patient. Contrast sensitivity was measured in each cardinal colour direction immediately before and 20 min after standard 20-flash fluorescein angiography. RESULTS: A significant, albeit mild, reduction for blue-yellow contrast sensitivity following angiography was observed (ANOVA, alpha = 0.05). Fluorescein angiographic exposure had no significant effect on red-green or luminance contrast sensitivity. CONCLUSION: Our results show that fluorescein angiography causes at least a short term deficit selective to blue-yellow contrast sensitivity in our patient group.

Aged↗
PubMed2001

Diabetic macular edema: passive and active transport of fluorescein through the blood-retina barrier.

PURPOSE: To investigate the passive bidirectional and active outward transport of fluorescein through the blood-retina barrier (BRB) in diabetic patients with clinically significant macular edema and in healthy controls. METHODS: The passive and active transport of fluorescein through the BRB was quantitated by vitreous fluorometry. A previously developed method was used to model passive transport. A new simulation model was developed and evaluated for estimation of active transport. The study included 10 eyes of 5 healthy controls and 31 eyes of 20 diabetic patients with clinically significant diabetic macular edema (CSME) in at least one eye, totalling 25 eyes with CSME. RESULTS: Passive permeability of fluorescein was increased by a factor of 12 in eyes with edema compared to healthy controls (edema, 23.7 nm/sec; healthy subjects, 1.9 nm/sec, P < 0.01), whereas the active transport was doubled (edema, 84.1 nm/sec; healthy subjects, 43.5 nm/sec, P < 0.01). Unlike active transport, passive permeability was related to the degree of retinopathy, in that eyes with severe non-proliferative diabetic retinopathy had a passive permeability that was significantly increased compared to moderate retinopathy (32.1 nm/sec and 14.6 nm/sec, respectively, P: < 0.05). The passive movement quantitated with vitreous fluorometry was larger for diffuse and mixed leakage compared to focal (P = 0.07). CONCLUSIONS: Insofar as the movement of fluorescein can be taken as a probe for the movement of electrolytes and water, the pathogenesis of diabetic macular edema seems to involve a disruption of the BRB, presumably its inner component. The active resorptive functions of the blood-retina barrier appear to be compensatorily increased to counteract edema formation, although the increase is too small to prevent edema in the face of severe leakage through the blood-retina barrier.

Adult↗
PubMed1975

The gingivitis fluorescein test in recruits.

The average individual status of gingival inflammation was evaluated in two groups of 39 and 47 subjects by means of the Gingivitis Fluorescein Test (GFT) and the Sulcus Bleeding Index. The subjects of the test group received a prophylaxis and hygiene instructions which were effective in reducing the gingivitis after 12 days. However, the reduction was not paralleled by a simultaneous decrease of fluorescein recovered in mouthwashings. The oral hygiene of the control group's subjects was not altered and examinations were performed after 7 days. In both groups the average SBI-score did not exceed 1.2 in all examinations. The fluorescein content of the mouthwashings was approximately 10 times reduced when compared with previous findings. No correlation was found between the amounts of fluorescein in mouthwashings and the severity or extent of the clinically assessed gingival inflammation.

Administration, Oral↗
PubMed2003

Fluorescein angiographically evident diabetic maculopathy.

Diabetic maculopathy seen in the Philippines, specifically, the associated factors, the various lesions seen on fluorescein angiography, and the visual acuity associated with these lesions were characterized using 127 patients (254 eyes) with diabetic retinopathy based on the fluorescein angiography done at the Eye Referral Center in 1993. Results showed that 116 (91.34%) patients have maculopathy, the majority of which is bilateral (84.25%). Age (p=0.675), sex (p=0.357), hypertension (p=0.742), duration of diabetes (p=0.778) and myopia (p=0.742) were not significantly associated with maculopathy. However, severity of retinopathy (p=0.001) was significantly associated with it. Fluorescein angiographic findings are macular staining (83.86%), perifoveal capillary dropout or macular ischemia (10.76%), and preretinal traction and membrane (5.38%). Microaneurysm (72.65%) is the most common lesion associated with macular staining, followed by capillary leakage (4.04%), cystoid macular edema (3.59%), perifoveal capillary dropout with microaneurysm (2.24%), and capillary with microaneurysm leakage (1.34%). Exudates are associated with microaneurysm, perifoveal capillary dropout or a combination of the two. Vision was found to be marginally statistically different between the normal and maculopathy group (p=0.0505). The worst vision was seen in macular ischemia and preretinal traction and membrane, with mean visual acuity of 0.18 and 0.25, respectively. It is concluded that severity of retinopathy is the only variable significantly associated with maculopathy in this study. Good vision does not necessarily indicate a normal macula. Detailed examination and fluorescein angiography should be carried out, regardless of duration of diabetes.

Adult↗
PubMedDate not supplied

A correlative study of ophthalmoscopy and fluorescein angiography in systemic hypertension.

This study correlates the fundus signs with the severity and signs of hypertension and evaluates the role of fluorescein angiography in detecting changes in the retinal and choroidal capillary bed in hypertension and defines its advantages over direct ophthalmoscopy. 37 hypertensives belonging to all grades of hypertension were studied. A thorough physical examination, hypertension work up, direct ophthalmoscopy and fluorescein angiography was done in all cases. A significant association was found between the presence of marked arteriolar narrowing and the presence of severe hypertension, left ventricular hypertrophy (LVH) and cardiomegaly. Patients having definite arterio-venous crossing changes and exudative retinopathy had a higher incidence of LVH and cardiomegaly. Renal functions and neurological signs in hypertension showed no correlation with the fundus signs. Capillary bed and choriodal abnormalities could be better studied on fluorescein angiography. Hard exudates were not visualized on fluorescein angiography. There was total resolution of exudative phenomenon on treatment.

Adult↗
PubMedDate not supplied

In vitro evaluation of fluorescein for testing the permeability of white spots on tooth enamel.

This investigation demonstrates the reliability of fluorescein for detecting the permeability of incipient dental caries (white spots). Artificial white spots were created on the buccal surface of 12 human bicuspids by viscous lactic acid (pH 4). Permeability of these lesions was assessed and reassessed before and after 24 and 48 hr of acid challenge using two disclosants: sodium iodide and sodium fluorescein. Estimates obtained from both disclosants showed that the microvoid volume approximately doubled as the decalcification time doubled. The two disclosants exhibited good intraclass reliability and their scores were correlated (r = 0.69 to r = 0.91). However, only fluorescein disclosed the extent of porous white spot lesions. Thus, fluorescein should be considered when the objective is to detect the location and permeability of incipient lesions.

Bicuspid↗
PubMedDate not supplied

[Fluorescein movement in a transparent lens].

Fluorescein movements in the lens laminae of isolated porcine eyes were examined by biomicroscopy. The stain disseminated in two directions: from the lens nucleus to capsules and fluorescein release into the intraocular fluid and from the outer laminae of the equatorial zone to the nucleus. Lecozyme, a proteolytic agent, accelerated fluorescein movement in both directions. The method suggested by the authors permits an objective assessment of fluorescein movement in the lens, which appears to reflect the processes of extracellular fluid ultrafiltration in the lens. The data evidence the possibility of effecting the extracellular intralenticular fluid microcirculation by proteolytic enzymes. The suggested technique may be useful in studies of cataract pathogenesis and of anticataract action of various drugs.

Animals↗