Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “FLUORESCEINS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 973 records · Page 54Linked to original sources
PubMed2002

Changes in fluorescein angiogram early after surgical removal of choroidal neovascularization in age-related macular degeneration.

BACKGROUND: Retinal pigment epithelial (RPE) defects inevitably occur in surgical removal of choroidal neovascularization (CNV) in age-related macular degeneration (AMD). RPE can proliferate and cover the denuded area, but the healing process has not been investigated in humans. To understand the RPE wound-healing process, we estimated the changes in fluorescein angiograms early after CNV removal. METHODS: Ten consecutive patients with exudative AMD underwent CNV removal without gas tamponade. Fluorescein angiography was performed within 4 days of surgery and again 1 or 2 weeks postoperatively. Areas of leakage were measured using a computer-assisted image analyser. The decreasing rate of leakage was calculated as the change in disc areas of leakage per day (DA/day). RESULTS: The rates of decreasing leakage ranged from 0 to 0.42 DA/day (mean, 0.24 +/- 0.15 DA/day; median, 0.26 DA/day). The rate of decreasing leakage correlated with changes in visual acuity (r = 0.642, P = 0.0456). CONCLUSION: The retinal pigment epithelial wound after surgical removal of choroidal neovascularization may heal at the rate of 0.24 disc areas/day based on the blood retinal barrier function in patients with age-related macular degeneration. A faster rate of decreasing leakage may be associated with better visual prognosis.

Aged↗
PubMedDate not supplied

Optic disk manifestation in diabetic eyes with low serum albumin: late fluorescein staining and high blood flow velocities in the optic disk.

PURPOSE: To evaluate ocular findings and blood flow characteristics in diabetes mellitus (DM) patients with low serum albumin (ALB). METHODS: We studied 106 eyes of 53 type II DM patients without proliferative diabetic retinopathy and panretinal photocoagulation. All underwent standard ophthalmic examinations, color Doppler imaging, and serum ALB measurements. The patients were divided into Group 1 (34 cases) with a serum ALB > or =3.8 g/dl and Group 2 (19 cases) with ALB<3.8 g/dl. RESULTS: All of the optic disks appeared normal by Ophthalmoscopy except one case with the lowest serum ALB. The number of optic disks showing late fluorescein staining was significantly higher in Group 2 than in Group 1. Peak systolic velocities in the central retinal artery (CRA, P=0.02) and central retinal vein (CRV, P<0.001) were significantly higher in Group 2, and significantly correlated with the serum ALB value (CRA; r=0.41, P=0.003 and CRV; r=0.60, P<0.001). CONCLUSIONS: We suggest that low serum ALB enhances the permeability of the vessels in or around the optic disk and induces subclinical optic disk edema, which is characterized by late fluorescein staining and high blood flow velocities in the CRA and CRV.

Aged↗
PubMedDate not supplied

Following the migration of a Toxocara larva in the retina by optical coherence tomography and fluorescein angiography.

BACKGROUND: The Toxocara larva is known to migrate across the retina, but the layer in which it migrates and its effect on the retina has been unknown. CASE: An ocular Toxocara infection was diagnosed by an immunological test on a vitreous sample from a patient with a retinal lesion that had migrated. Optical coherence tomography (OCT) and fluorescein angiography (FA) were used in this investigation. OBSERVATIONS: Many small lesions were first detected in the peripheral retina, and vitrectomy was performed because of vitreous haze. Two peripapillary lesions were found during the vitrectomy. OCT of one lesion demonstrated a highly reflective mass located in the nerve fiber layer, and FA showed dye leakage from the lesion as well as hyperfluorescence of the disc. Three weeks later, another lesion was found in the macular area, and OCT and FA findings were the same as for the first lesions. Fluorescein leakage was also observed along the presumed path of the migrating larva. CONCLUSIONS: The movement of the lesion from the peripapillary area to the macular area suggested that a Toxocara larva had migrated across the retina. OCT images indicated that the larva moved in the nerve fiber layer, and FA showed that it caused severe inflammation along its pathway.

Animals↗
PubMed2005

Extractive spectrofluorometric determination of quinalphos using fluorescein in environmental samples.

A simple, sensitive, convenient and low cost spectrofluorometric technique for determination of quinalphos is described. Quinalphos is decomposed with sodium ethoxide. Resultant sodium diethyl thiophosphate (Na-DETP) is extracted with a cationic fluorescein as ion pair complex into 1-chloro-2-nitrobenzene. The fluorescence of the ion pair, fluorescein-DETP is measured at 530 nm after excitation at 490 nm. This technique is applicable for the determination of quinalphos in water, food grains and vegetable samples up to ng level with Amberlite XAD-4.

Environmental Monitoring↗
PubMed2006

Fluorescein angiographic features of the congenital hypertrophy of the retinal pigment epithelium in the familial adenomatous polyposis.

PURPOSE: To asses the prevalence of fluorescein angiographic features in bilateral and multifocal Congenital Hypertrophy of the Retinal Pigment Epithelium (CHRPE) in patients with a diagnosis of familial adenomatous polyposis. METHODS: We performed prospective angiographic and clinical examination of 49 CHPRE lesions in 15 patients. RESULTS: About 77.5% of CHRPE lesions were close to retinal vessels. The retinal vascular changes observed overlying and surrounding the CHRPE were: capillary non-perfusion with an area greater than 0.5 disc diameters (41%), capillary microaneurysms (4%), chorioretinal anastomoses (6.2%), attenuation of retinal vessels (4%), choriocapillary vessels inside the lacunae (6.2%) and in the depigmented marginal halo (18.4%). Depigmented streaks in contact with one or both edges of the CHRPE were observed in 79.6% of the lesions. About 9.6% of the lesions were not seen on ophthalmoscopy and could only be detected by angiography. CONCLUSIONS: Even though the diagnosis of CHRPE is clinical, fluorescein angiography may be useful in confirming the diagnosis, as well as detecting additional lesions not seen by means of ophthalmoscopic examination.

Adenomatous Polyposis Coli↗
PubMed2006

A fluorescein-based fluorogenic probe for fluoride ion based on the fluoride-induced cleavage of tert-butyldimethylsilyl ether.

A highly sensitive and selective fluorogenic probe for fluoride ion, fluorescein di-tert-butyldimethylsilyl ether (FTBS), was designed and synthesized. FTBS was a colorless, non-fluorescent compound and was synthesized via the one-step reaction of fluorescein with tert-butyldimethylsilyl chloride. Upon incubation with fluoride ion in DMF-water solution (7 : 3, V/V), the Si-O bond of FTBS was cleaved, causing a large increase in fluorescence intensity and thereby allowing a selective detection of fluoride ion. The fluorescence increase is linearly with fluoride concentration in the range 0.1-2.0 mumol L(-1) with a detection limit of 0.041 mumol L(-1) (3sigma). The excellent selective signaling behavior of the proposed probe was found to originate from the high affinity of silicon toward fluoride ion. The method has been successfully applied to the fluoride determination in multi-trace elements injection and toothpaste samples, and the results are agreed well with those obtained by the fluoride-ion selective electrode method.

Fluorescein↗
PubMed1976

Fluorescein angiography with an optimized filter combination.

The transmission characteristics of a new filter combination for fluorescein angiography were selected on the basis of in vivo measurements of the excitation and emission spectra of fluorescein dye during its transit in the fundus. This combination of filters was characterized by separation of 530 nm between the spectral ranges of transmission of the excitation and barrier filters. In the standard filter combinations this separation is at about 495 nm. Compared to the standard filters, the new filters enhanced the film exposure for all sites of the fundus, especially for the macular area and choroidal fluorescence. There was an improvement in demonstration of the choroidal vasculature, especially in the macular area, and better visibility of retinal detail in the macular area, but a slight decrease in contrast of the retinal vessels outside the macular region. Improved visibility of the fundus for the observer and reduction of scattering in the ocular media of older subjects improved the overall quality of angiograms made with the new filters.

Adolescent↗
PubMed1977

Cycloscopy and fluorescein cycloscopy of the ciliary process.

A new gonio-cycloscope that magnifies an object up to 1.5 times was designed to observe the ciliary process and chamber angle. As a result of aging, the ciliary process became hypertrophic and more branched with discoloration. Leakage of fluorescein from the ciliary process decreased as intraocular pressure artifically increased, stopping completely at 50 mm Hg or more. Water drinking accelerated fluorescein leakage, while oral glycerol diminished it.

Adolescent↗
PubMed1977

Fluorescein pattern of the choriocapillaris in the neonatal rhesus monkey.

Seven neonatal rhesus monkeys were studied by serial fundus photography and fluorescein angiography at weekly intervals during the first 12 weeks of life. The neonatal rhesus showed little pigmentation of the fundus during the first six weeks of life. The fluorescein angiograms showed a definite sequential as well as segmental filling pattern at the level of the choriocapillaris. This filling pattern was based on individual units called lobules. In addition there was a segmental flow in the macula; that is, the nasal macula filled before the temporal macula.

Animals↗
PubMed1981

Morphologic fluorescein angiographic, and light microscopic features of experimental choroidal neovascularization.

We induced choroidal neovascularization in the rhesus monkey by impoverishing the blood supply to the inner retina and producing defects in Bruch's membrane by photocoagulation. Fourteen of 46 eyes undergoing photocoagulation developed neovascular fronds which were identified and categorized by histopathologic examination and fluorescein angiography. All new vessels gained access to the retina through defects in Bruch's membrane at the site of photocoagulation marks. In eight eyes the new vessels remained localized to the immediate vicinity of photocoagulation marks. In four eyes neovascular fronds infiltrated the subretinal space for distances up to 6 disk diameters from the point of entry into the retina. In the two eyes choroidovitreal neovascular complexes developed but rapidly regressed shortly after gaining the vitreous cavity. Fluorescein angiography demonstrated that all neovascular fronds were grossly incompetent to dye but that formed feeding channels had some degree of integrity. Light microscopic studies showed the proliferating networks to be composed of capillaries with well-formed basement membranes and more mature vessels with the basic structure of choroidal arteries and veins.

Animals↗
PubMed1983

Ethylated fluoresceins: assay of cytochrome P-450 activity and application to measurements in single cells by flow cytometry.

Four ethylated derivatives of fluorescein were synthesized and their metabolism by mouse liver homogenates and cultured mouse hepatoma cells was investigated. Two of the ethylfluoresceins are specifically metabolized by the polycyclic aromatic hydrocarbon inducible cytochrome P-450 to yield fluorescein, which is about 15 times more fluorescent than the ethylated compounds. One of these fluorogenic derivatives, ethoxyfluorescein ethyl ester, is useful for flow cytometric analysis and sorting of intact, viable cells on the basis of cytochrome P-450 activity. The structure-activity relationship of the ethylfluoresceins is discussed.

Animals↗
PubMed1987

4'-[Aminomethyl]fluorescein and its N-alkyl derivatives: useful reagents in immunodiagnostic techniques.

A new class of fluorescein derivatives with chemically reactive amino and N-alkylamino "arms" in the 4'-position were synthesized and their utility in the development of fluorescence polarization immunoassays (FPIA) for cortisol and estriol was evaluated. The positioning of the arm in one of the phenolic rings introduced chirality due to hindered rotation and led to rotational isomers. These were separable when brought into a chiral environment, i.e., conjugated to steroid molecules. In the case of cortisol conjugates, the rotamers had similar properties in the FPIA. In the case of estriol conjugates, however, each rotamer exhibited different immunoassay characteristics. The rotamers interconverted at 80 degrees C, with the rate increasing with temperature. An unusual N-alkylation phenomenon by alkanols in acidic medium was observed. A serum cortisol FPIA, developed using an N-alkylamino fluorescein derivative, showed good correlation with a reference RIA.

Alkylation↗
PubMed1989

Hydrophilic fluorescein derivatives: useful reagents for liposome immunolytic assays.

Hydrophilic derivatives of fluorescein containing hydroxyalkyl substituents were synthesized and encapsulated within liposomes. The fluorophores showed significantly more retention with time than did fluorescein, carboxyfluorescein, or calcein. Unlike calcein, the fluorophores are minimally susceptible to fluorescence quenching by Co2+. The utility of these compounds as immunodiagnostic reagents was demonstrated by encapsulating 5(6)-carboxyfluorescein trismethylolamide in haptenized liposomes which were used in an immunoassay for digoxin.

Chemical Phenomena↗
PubMed1975

Absence of cell communication for fluorescein and dansylated amino acids in an electrotonic coupled cell system.

Quantitative evaluation of the diffusion process of sodium fluorescein and dansylated amino acids in the salivary gland of the larvae of Drosophila hydei reveals that the differences in specific permeability between the junctional and nonjunctional membranes, as found for small ions, do not apply to the fluorescent probes. There are no significant differences between the permeability properties for the different dansylated amino acids tested, and the same properties are found for sodium fluorescein.

Animals↗
PubMed1979

Characterization of the membrane fraction isolated by the fluorescein mercuric acetate technique of Barland and Schroeder.

Using scanning electron microscopy we have demonstrated that tha membrane fraction isolated by the fluorescein mercuric acetate technique of Barland and Schroeder (Barland, P. and Schroeder, E.A. (1975) J. Cell Biol. 45, 662-668) represents a topologically distinct membrane which circumscribes the cell nucleus. Our data suggest that not all the cells within a non-synchronized cell population release a membrane fraction after treatment according to the technique of Barland and Schroeder, but rather that the efficiency of membrane release achieved using this preparative technique is dependent on the morphology of individual cells. Our work has also demonstrated that the peptide composition of the membrane fraction isolated by the technique of Barland and Schroeder differs from the peptide composition of the plasma membrane-enriched fraction isolated by the technique of Brunette and Till (Brunette, D.M. and Till, J.E. (1971) J. Membrane Biol. 5, 215-224). This difference in peptide composition is particularly noticeable among the higher molecular weight proteins, glycoproteins and iodineateable membrane components. The data which we have accumulated suggest that the compositional differences noted between the two membrane isolates do not result from differential extraction of membrane components during the ZnCl2-fluorescein mercuric acetate treatments required in the isolation technique originally described by Barland and Schroeder. However, our data do clearly demonstrate that the membrane isolation technique of Barland and Schroeder cannot be used to study the general composition of the plasma membrane.

Cell Fractionation↗
PubMed1992

Two-dimensional poly(acrylamide) electrophoresis of fluoresceinated glycopeptides. Resolution and structural characterization of ovalbumin glycans.

The microheterogeneous mixture of fluoresceinated glycopeptides (FGPs) obtained from the single site of glycosylation of chicken ovalbumin was resolved by a combination of discontinuous electrophoresis in a high-density poly(acrylamide) gel (PAGE) for sizing, in conjunction with borate-PAGE. Two FGPs of similar size but with different mobilities in borate-PAGE were purified and characterized by sequential exoglycosidase digestion and sizing on the discontinuous PAGE system, as well as by methylation analysis. The two FGPs of identical size are distinct and have structures beta-D-Glc pNAc-(1-->2)-alpha-D-Man p-(1-->3)-[beta-D-Glc pNAc-(1-->4)]-[beta-D-Glc pNAc-(1-->2)-alpha-D- Man p-(1-->6)]-beta-D-Man-p-(1-->4)-beta-D-Glc pNAc-(1-->4)-beta-D-Glc pNAc-1-->R and alpha-D-Man p-(1-->2)-alpha-D-Man p-(1-->3 or 6)-[alpha-D-Man p-(1-->3)-[alpha-D-Man p-(1-->6)]-alpha-D-Man p-(1-->6 or 3)]-beta-D-Man p-(1-->4)-beta-D-Glc pNAc-(1-->4)-beta-D-Glc pNAc-1-->R (R = Asn-(amino acids)-fluorescein). The results demonstrate that two-dimensional PAGE is applicable to the separation and characterization of complex mixtures of FGPs. The procedure is rapid, sensitive, and convenient for glycopeptide mapping, and for the purification and structural characterization of glycans. Furthermore, the FGPs can be characterized with affinity matrices, such as lectins, and by methylation analysis.

Carbohydrate Sequence↗
PubMed1981

Reproducibility of the densitometric analysis of fluorescein angiograms.

Computer-aided operator-interactive densitometry was applied to assess the reproducibility or retinal-fluorescein angiograms. To achieve this, the fundus camera images of glass tubings of various diameter filled with fluorescein of varying concentrations were subjected to densitometric analysis. These studies were carried out repeatedly at 9-micrometer and 29-micrometer scanning resolutions by three observers and thus the inter- and intra-operator errors could be estimated. The scanned data were analyzed as both optical densities and intensities for some of the measurements. In both analyzing modes good linearity was obtained when the densitometric response was plotted against tubing diameter for various concentrations. To determine the reproducibility of transit time and retinal circulation time analyses, a randomly selected patient's angiogram was repeatedly analyzed by three observers and compared. From these data the inter- and intra-operator errors were also determined for successive frames and the reproducibility of the area under the dye dilution curves for both arteries and veins was computed. The overall densitometric reproducibility was found to be good; however, practical usefulness of the retinal circulation time remains to be established.

Angiography↗