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At least 1,135 records · Page 63Linked to original sources
PubMed1975

Indoluble collagen II. The use of fluorescein labelled polymeric collagen fibrils in a very sensitive assay procedure for enzymes degrading insoluble collagen.

98% of the collagen in mature connective tissue is in the form of insoluble collagen fibers, consisting of bundles of polymeric collagen (PC) fibrils. The enzymes concerned in connective tissue remodeling degrade PC rather than tropocollagen (TC). TC is the most usual substrate for collagenase assays, and we believe it is essential to employ PC in any study of the activity of collagenolytic enzymes. In order to facilitate the study of enzymic degradation of PC we have labelled PC with fluorescein iso-thiocyanate to produce F-PC fibrils, containing 5 fluorescein labelled epilson-NH2 groups of lysine per TC molecule within the PC. The fluorescent F-PC is degraded at the same rate as PC with the release of hydroxyprolyl peptides but has the great advantage that the solubilised F-peptides can be quantitated by their fluorescent emission. The technique is described in detail employing bacterial collagenase and mammalian collagenase preparations to illustrate the methodology. The advantages of the fluorescent technique over the collagenolytic assay methods currently in use are outlined.

Animals↗
PubMed1983

Reconstitution of LDL with lipophilic fluorescein derivatives: quantitative analysis of the receptor activity of human lymphocytes.

Low density lipoprotein (LDL), the major cholesterol transport protein in human plasma, consists of an apolar core of cholesteryl esters surrounded by a polar shell containing phospholipids, unesterified cholesterol and protein. In the current paper we report the absorption and fluorescence spectra of members of a new class of lipophilic fluorescein derivatives which were designed to be reconstituted into the core of LDL in place of the native cholesteryl esters. One of these derivates, cholesteryl 12-O-[methyl 3-O-methyl-5' (6')-carboxyfluorescein]ricinoleyl carbonate (MMC) was reconstituted into the core of LDL. The resultant fluorescent reconstituted LDL was used in conjunction with flow cytometry to quantify the LDL receptor activity of fresh blood lymphocytes derived from normal individuals and from patients with the heterozygous and homozygous forms of familial hypercholesterolemia (FH). The LDL receptor activities of the heterozygous and homozygous FH lymphocytes were approximately 37% and 1% of normal, respectively. LDL reconstituted with these lipophilic fluorescein derivatives will be valuable in studying LDL metabolism and may be useful for the diagnosis of FH.

Fluoresceins↗
PubMed2005

In vitro bioassay of endotoxin using fluorescein as a pH indicator in a macrophage cell culture system.

Based on the biological activity of endotoxin, we propose a possible new method for detecting endotoxin using a pH-indication system of macrophage culture media. After RAW 264.7 macrophage cells were treated with lipopolysaccharide (LPS), the addition of fluorescein to the LPS-treated media reproductively reduced its absorption and emission spectra (it was a dose-dependent reduction). The advantages of this LPS-detection method were compared with the Limulus Amebocyte Lysate (LAL) test by using purified bacterial LPS (Salmonella minnessota, Escherichia coli, and Pseudomonas aeruginosa). Additionally, the absorption and fluorescence intensity of fluorescein, following treatment of RAW 264.7 cells with a high concentration of Staphylococcus aureus (Gram-positive, lysed bacteria), could not generally be detected by the LAL test, but they were found to be reduced, in a dose-response relationship, with this new system. The macrophage culture system-method might be a good supplement to the LAL assay for detection of LPS, Gram-negative and Gram-positive bacteria.

Animals↗
PubMed1976

Fluorescein angioscopy: techniques of partial fluorescence, permanent drawing record and photocoagulation.

Fluorescein angioscopy with the indirect ophthalmoscope might be the preferred technique for evaluating and treating certain lesions, particularly those in the retinal periphery. Three techniques which are helpful in extending the advantages of angioscopy are described. (1) Partial fluorescence is achieved with careful adjustment of the cobalt blue filter which relates the fluorescence to retinal landmarks, ie, color angioscopy. (2) A permanent record of angioscopy in different phases can be made with tracing paper over the retinal drawing. (3) Correct localization of lesions to be coagulated is achieved with blue filters over the coagulator beam following fluorescein injection. The filter is removed during coagulation.

Color↗
PubMed1997

[Correlations between retinal fluorescein angiography and blood viscosity and other factors in patients with primary open angle glaucoma].

OBJECTIVE: To investigate the correlations between retinal fluorescein angiography and blood viscosity and other factors in patients with primary open angle glaucoma (POAG). METHODS: Multiple stepwise regression analysis was made to approach the correlation between each of the following blood vessel filling times: the arm-choroid (A-CT), arm-retinal artery (A-AT), and retinal artery-venous (A-VT) of the fundus fluorescein angiography (FFA) in 122 eyes with POAG and each of the following related factors in hemorheology: whole blood apparent viscosity at low, medium and high shear rates, plasma viscosity and hematocrit. Also, the same analysis was applied to investigate the correlation between each of the A-AT, A-VT of the FFA in 70 eyes with POAG and each of the following factors: systolic blood pressure, diastolic blood pressure, age and the whole blood apparent viscosity at low shear rate. RESULTS: The whole blood apparent viscosity at low shear rate was closely related to A-CT and A-AT, while hematocrit was closely related to A-VT of the FFA. The whole blood apparent viscosity at low shear rate and age, especially whole blood apparent viscosity, was closely related to A-AT, A-VT of the FFA. CONCLUSION: The blood viscosity can affect the filling times of the FFA in POAG.

Blood Viscosity↗
PubMedDate not supplied

[Value of fluorescein angiography in control of retinal thermal damage due to diode laser].

PURPOSE: To evaluate on an ocular ophthalmic model the interest of digitized fluorescein angiography for a control of laser induced thermal damage. METHOD: After anesthesia, retinal photocoagulation was performed on 6 rabbit eyes with a 810 nm diode laser (p = 100 to 400 mW, phi = 500 microns, 1s) (OcuLight, IRIS Medical Instruments Inc., USA). Fluorescein angiography was then performed with measurements of fluorescence intensity in the area of the laser exposures (CF-60UVi Canon-Europe, The Netherlands; OcuLab, Life Science Resources Ltd, England). RESULTS: Image analysis shows that the laser lesions stained progressively. For dosages up to 100 +/- 20 mW fluorescence intensity at the center of the laser spot could be modelized with: Icentrer = Imax [(1-e-alpha t)]-Ce beta t with alpha = 0.2 (s-1), beta = 0.46 (s-1); Imax 230 and C = 0.92. For dosages superiors to 200 +/- 20 mW the modelization was: Icenter = Imax [(1-e-alpha t)] with alpha = 0.2 (s-1 and Imax = 230. CONCLUSION: This study demonstrates that quantitative assessment of laser-induced damage to the retina is feasible using fluorescence imaging. The quantification of fluorescence staining in terms of both intensity and time can contribute to a better quantification of laser-induced damage.

Animals↗
PubMed1999

[Fluorescein angiography in children and adolescents with type I diabetes mellitus].

PURPOSE: The evaluation of changes in ophthalmoscopic examination and fluorescein angiography in children and adolescents with insulin dependent diabetes mellitus. MATERIAL AND METHODS: 100 patients with type I diabetes mellitus aged 9.3-21.5 years (15.76 +/- 2.69), with diabetes duration of 1-13.5 years (6.57 +/- 2.52) were examined. RESULTS: Retinal changes in ophthalmoscopic examination were observed in 12 cases. Fluorescein angiography allowed to detect diabetic retinopathy in 29 patients. There was no correlation between the incidence of retinopathy and the age of patients. Vascular abnormalities were related to the duration of diabetes. Retinopathy was not found in children < 10 years of age.

Adolescent↗
PubMed1999

A fluorescein angiographic study of branch retinal artery occlusion (BRAO) - the retrograde filling of occluded vessels.

BACKGROUND: For assessing the prognosis of a branch retinal artery occlusion (BRAO), examination of the arterial blood flow by fluorescein angiography is necessary. PATIENTS AND METHODS: In seven patients (mean age: 68.1, youngest 61, oldest 76 years old), with BRAO of varying involvement and extent, the disturbed retinal blood flow was demonstrated by this method. All the patients were subjected to Doppler sonography of the carotid arteries and all had a general medical examination. RESULTS: The most impressive sign was the retrograde filling of the retinal arterial and/or venous branches from the adjacent retinal vessels and capillaries. In four patients the visual acuity was better after the disappearance of the retinal edema. In one patient the visual field defect slightly decreased at follow-up. This means that not every patient with retrograde filling of dye in BRAO has a bad prognosis in terms of visual function. The extent and duration of the retrograde filling with dye and the arterial or venous passage varied from patient to patient. There was also delayed filling with an increased period of retention in an artery (which is an adverse sign in BRAO), and retrograde filling of the corresponding vein. This latter came from small adjacent veins, but the retrograde filling of an artery came from capillaries or from very small adjacent arterioles. All the patients showed signs of general systemic disease, such as occlusion or the presence of plaques in the carotid artery, absolute arrhythmia, arterial hypertension, patent foramen ovale, diabetes mellitus, hyperuricemia, Factor V mutation, homocysteinemia or coronary heart disease. CONCLUSION: Retrograde filling of the retinal arterial and/or venous branches means a kind of spontaneous healing compared to a condition with complete permanent obstruction of circulation. It is recommended that fluorescein angiography should be carried out for all patients with BRAO, in order to estimate the prognosis of the vascular occlusion. This is the first published record of consecutive pictures showing the retrograde filling of retinal arteries and/or veins with BRAO. In every patient with a BRAO an extensive medical and neurological examination (including echocardiography and Doppler sonography of the carotid arteries) is essential before planning the treatment.

Aged↗
PubMed2000

Evaluation of fluorescein-labeled autologous leukocytes for examination of retinal circulation in humans.

PURPOSE: Increased leukocyte-endothelium interaction have been suggested as a phenomenon contributing to capillary occlusion and/or rupture of the blood-retina barrier during human retinal vascular diseases. This study was performed to evaluate if fluorescein-labeled autologous leukocytes (FLALs) can be used for examination of leukocyte transit in the human retina. METHODS: The preparation consisted of human dextran-separated leukocytes mixed with fluorescein. After reinjection in normal subjects and in one diabetic patient, a confocal scanning laser ophthalmoscope was used to visualize them in the retinal circulation. The changes between FLALs and control leukocytes in the expression of leukocytes adhesion molecules CD11b and CD62L were evaluated by flow cytometry. RESULTS: The circulating FLALs were clearly visible in retinal vessels. The mean (+/- SD) capillaries velocity was 1.43 (+/- 1.3) mm/s in the macula and 1.82 (+/- 1.4) mm/s in the peripapillary area. No leukostasis was detected in the normal subjects, while it was detected in te diabetic patient. Flow cytometry revealed an increase in CD11b and a decrease in CD62L expression of leukocytes after labeling, suggesting that compared to normal leukocytes FLALs are more susceptible to interact with vascular endothelium. CONCLUSIONS: The use of FLAL is presently the only technique applicable in humans for study of leukocyte transit in the retina. Their preparation is technically simple and unexpensive. Precise measurement of the velocity of leukocytes in small vessels can be obtained. Despite evidence of a certain degree of leukocyte activation after the labeling procedure, no leukostasis was detected in vivo in normal subjects. Potential applications for this technique may include the detection of leukostasis in the human retina during severe forms of diabetes and retinal phlebitis.

Adult↗
PubMed1975

The effect of fluorescein conjugation on Fc-dependent properties of rabbit antibody.

Conjugation of rabbit antibody with fluorescein isothiocyanate results in loss of the ability of that antibody to fix complement, mediate passive cutaneous anaphylaxis, or participate in cytophilic binding to macrophage surfaces. Fluorescein, perhaps because of molecular size or configuration, is a more potent suppressor of Fc function than are other reagents previously studied in this regard.

Animals↗
PubMed1975

Fluorometric serum lipase assay: evaluation of monodecanoyl fluorescein as substrate.

The elements of the mechanized fluorometric lipase (EC 3.1.1.3) assay of Fleisher and Schwartz [Clin. Chem. 17, 417 (1971)] were made optimum; a manual adaptation was also developed. Hydrolysis of the monodecanoyl fluorescein substrate by hog pancreatic lipase is a zero-order reaction. The hydrolytic activity of normal human serum, serum from hospitalized patients without pancreatitis, and serum from patients with acute pancreatitis showed considerable overlap. Bile salts, considered activators in titrimetric or turbidimetric lipase assays, inhibited hydrolysis of the substrate by human serum. We conclude that monodecanoyl fluorescein is not a specific substrate for the serum lipase measured in acute pancreatitis.

Acute Disease↗
PubMed1975

Toxic maculopathy part II: A result of quinine usage as demonstrated by fluorescein angiography and electroretinography.

In this paper, further investigation by fluorescein angiography and electroretinography (ERG) was undertaken to substantiate the possible toxic maculopathy due to quinine usage. Again, positive Amsler chart tests were found in 3 of 14 (21%) of the drug addicts with blurred vision, a common complaint among these patients. The results of 5 fluorescein angiography examinations demonstrated no leakage of dye, especially in the macula. Twenty-four ERG examinations revealed no statistical differences between the test group patients and the control subjects. It was concluded that there is a definite need to carefully examine the eyes of any person who has used quinine for a long time since positive Amsler chart tests were found in 37% of the drug addicts.

Electroretinography↗
PubMedDate not supplied

Fluorescein angiographic findings in an infected scleral buckle.

This report presents fluorescein angiographic (FA) findings in a patient with scleral buckle infection. Ten days following scleral buckling surgery, FA demonstrated dilated choroidal vessels over the buckle with leakage of fluorescein into the subretinal space. Irregular diffuse scleral thickening was noted on the computed tomography (CT). The findings of focal choroiditis with dilated leaky choroidal vessels seen on FA, or diffuse scleral thickening demonstrated by a CT may aid in establishing the diagnosis of scleral buckle infection.

Anti-Bacterial Agents↗
PubMed1999

Clinical investigation of radiation retinopathy fundus and fluorescein angiographic features.

PURPOSE: To investigate the fundus and fluorescein angiographic features in the patients with radiation retinopathy. CLINICAL MATERIALS: Color fundus photography and/or fluorescein angiography from 13 patients with nasopharyngeal carcinomas received external beam radiation were retrospectively analyzed. RESULTS: In this study, 26 damaged eyes of 13 patients developed some degree of radiation retinopathy. The earliest and most common finding was macular microvascular changes (microaneurysms and/or telangiectasia), which was observed in 100% (26/26) of the eyes. Intraretinal hemorrhages, macular capillary nonperfusion, and mascular edema were noted in 84%, 50%, and 42% of the eyes, respectively. CONCLUSIONS: Radiation retinopathy is common after external beam radiation of nasopharyngeal carcinomas. The prominent changes include macular microvascular changes, intraretinal hemorrhages and macular capillary nonperfusion.

Adult↗
PubMedDate not supplied

Nurse-led management of i.v. fluorescein angiography.

Fluorescein angiography is undertaken to investigate the state of the circulation in diabetic eye disease, the commonest manifestation of which is diabetic retinopathy. Senior ophthalmic nurses, equipped with the appropriate skills and level of confidence, are now undertaking the procedure. In the eye centre at the Central Middlesex Hospital, a proactive nurse-led approach to the management of patients undergoing fluorescein angiography has had a significant impact on the outcomes of the procedure, and resulted in positive patient feedback.

Clinical Competence↗
PubMed2003

[Fluorescein angiography in diabetic retinopathy].

Fluorescein angiography plays an important role in diagnosis, classification and management of diabetic retinopathy. He paper presents angiographic aspects of some patients from "LASER OPTICS" office. An accurate and early diagnosis, and also the evaluation of laser treatment need fluorescein angiography as a useful method in the follow-up of diabetic patient.

Adult↗
PubMed2002

[Study on the properties of solid substrate room temperature phosphorescence of the antibody labeled with fluorescein isothiocynate].

The properties of room temperature phosphorescence (RTP) of the labeled goat anti-human antibody(with fluorescein isothiocynate GAHAb-FITC) and labeled rabit anti-goat antibody(RAGAb-FITC) with FITC in different dilution ratios on many kinds of solid substrates were studied in detail. It is found that on the polyamide membrane, only using Pb(Ac)2 as a heavy atom perturber, both the labeled antibodies and their antigen-antibody conjugated compound with the human immunoglobulin G remained excellent RTP properties of isothiocyanate fluorescein, lambda ex(max)/lambda em(max) = 525/650 nm, the relation of RTP intensity to the concentration was linear in a certain range. The conditions for immunological reaction and RTP emission were optimized. The result means that it is possible to develop a new immunoassay named as solid substrate room temperature phosphorescence immunoassay (SS-RTP-IA), which combines both the specificity of immunological reaction and high sensitivity of luminescence analysis.

Animals↗