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At least 1,405 records · Page 78Linked to original sources
PubMed1984

Sensitivity of detecting Chlamydia trachomatis elementary bodies in smears by use of a fluorescein labelled monoclonal antibody: comparison with conventional chlamydial isolation.

Commercially produced fluorescein labelled monoclonal antibodies for the detection of Chlamydia trachomatis have recently become available. One is for detecting inclusions in cell culture (culture confirmation) and the other for detecting elementary bodies in smears from potentially infected sites. We have compared the two monoclonal antibodies with our routine isolation method, which utilises Giemsa staining of cycloheximide treated McCoy cell cultures. The culture confirmation system offered no advantages over Giemsa staining for the detection of inclusions in cell monolayers. By contrast, using monoclonal antibody to detect elementary bodies in smears was much quicker and simpler and slightly more sensitive than isolation of chlamydiae in cell culture. For specimens from seven babies with conjunctivitis and from 35 female contacts of men with non-gonococcal urethritis, there was complete agreement between the results of detecting inclusions in culture and those of seeking elementary bodies in smears. For samples from 100 men with non-gonococcal urethritis and from 100 men with gonorrhoea there was 99% and 94% agreement, respectively, between the results of the two tests. Other aspects and possible uses of the new detection system are discussed.

Antibodies, Monoclonal↗
PubMed1987

Secretion from corticotropes after avidin-fluorescein stains for biotinylated ligands (CRF or AVP).

Viable pituitary target cells were identified with biotin-labeled corticotropin-releasing factor (1-Bio-CRF) or arginine vasopressin (Bio-AVP) and avidin-fluorescein (cell sorter grade). Stain was reduced from 8-10% of pituitary cells to less than 3% if nonbiotinylated ligands were added to compete with their respective biotinylated ligand for specific binding sites. However, AVP did not decrease the stain for 1-Bio-CRF nor did CRF decrease the Bio-AVP stain. Media adrenocorticotropin (ACTH) levels increased 4-18 times when 1-Bio-CRF or Bio-AVP were added during the staining process. One hour after staining, the cells secreted ACTH at levels identical to prestain basal levels. When challenged with CRF or AVP after this hour, the cells responded again with increases not different from those seen during staining. Tests of stained cell populations also showed that the cells were fully responsive 24 h after staining. The reverse hemolytic plaque assay for ACTH, which was used to study secretion from individual stained cells, showed that approximately 80% of plaques contained a stained cell and that plaque numbers and areas were like those of unstained populations. These data show that corticotropes are not chronically desensitized during exposure to low doses of biotinylated ligands (50-500 pM).

Adrenocorticotropic Hormone↗
PubMed1978

Fluorescein dye-dilution technique and retinal circulation.

Using theoretical models for the flow of fluourescein dye in retinal arteries and veins, we have determined the effects of optical absorption in blood of the incident excitation light and the emitted fluorescent light on the time course of measured fluorescence intensity, I(t). Our results indicate that I(t) curves recorded from arteries adequately represent the mean time course of the fluorescein concentration (C(t)), when either a circular or rectangular light-collecting aperture is used. I(t) curves recorded from veins adequately represent C(t), but only when a circular aperture of approximately the same diameter as that of the vessel is used. A two-point fluorophotometer, which provides simultaneous, on-line measurements of arterial and venous I(t) curves is described. Typical recordings obtained with the instrument are shown and the method employed to analyze the curves quantitatively is described in detail. This method, which consists of fitting the first passage of the fluorescence intensity curve with a log-normal function, provides results that are more accurate than those obtained using the standard exponential extrapolation method.

Dye Dilution Technique↗
PubMed1994

Confocal microscopic analysis of fluorescein compartmentation within crab urinary bladder cells.

Fluorescein (FL), a fluorescent organic anion, is compartmentalized in cells of organic anion-secreting epithelia, e.g., OK cells, teleost proximal tubule, and crab (Cancer borealis) urinary bladder, a proximal tubule analogue. To further examine the processes involved, FL uptake and distribution were studied in C. borealis urinary bladder cells using epifluorescence and laser confocal microscopy combined with video-image analysis. Intracellular FL was about evenly split between diffuse and punctate compartments after in vitro or in vivo loading. Treatments that affected FL transport into cells (incubation with p-aminohippuric acid or glutarate) altered the FL content of both compartments. However, nocodazole, a microtubule inhibitor, did not affect diffuse FL but significantly reduced punctate FL. Finally, confocal analysis indicated that individual sites of punctate FL accumulation moved in the secretory direction at 0.83 micron/min. Nocodazole nearly abolished this movement and significantly reduced transepithelial organic anion secretion. Thus, in crab urinary bladder, a substantial fraction of total cellular FL is sequestered in vesicles, and these vesicles move in the secretory direction, by a microtubule-dependent process.

Animals↗
PubMed1996

Effect of interleukin-1 alpha, interleukin-1 beta and tumor necrosis factor-alpha on the intracellular fluorescein fluorescence polarization of human lung fibroblasts.

In the present study we aimed to detect early intracellular changes in the cytoplasmic matrix induced in human, pulmonary-derived fibroblasts following exposure to interleukin (IL)-1 alpha, IL-1 beta and tumor necrosis factor-alpha. Such changes were detected by measuring intracellular fluorescein fluorescence polarization (IFFP) using the Cellscan apparatus. IFFP measurement was selected in our study since it has been shown to reflect the microviscosity of the cytoplasmic matrix. Significant reductions (> or = 5%) in the IFFP were induced in fibroblasts by all the cytokines employed. The effect of cytokines on IFFP was achieved at concentrations of 5-10 ng/ml of the cytokines. The reduction in IFFP, following stimulation with the cytokines, was detected as early as 20 min after exposure to the cytokines, lasted at least 40-60 min after exposure to IL-1 alpha and IL-1 beta, and was inhibited by vinblastine, an inhibitor of the polymerization of microtubules. Our results show that IFFP measurements by the Cellscan may reveal rapid intracellular changes occurring in the cytoskeleton components of activated cells.

Cytochalasin B↗
PubMed1984

Maintenance of platelet viability after platelet-labeling with fluorescein isothiocyanate.

Possible effects of an ex vivo fluorescent labeling procedure of blood platelets on the platelet viability were examined by different function tests. The degree of the impairment of the platelet function proved to be principally correlated with the dye concentration used during the labeling procedure. However, the physiological properties of the labeled platelets obviously remain unrestricted by using intraplatelet fluorescein isothiocyanate (FITC) concentrations below 0.55 mg/10(11) platelets, corresponding to 8.5 X 10(6) FITC molecules bound to one platelet. A procedure for fluorescent labeling of blood platelets is described which is considered to be preferably suitable to prepare platelets for vital microscopic platelet observations.

Adenosine Diphosphate↗
PubMed1994

Blood volume determination with sodium fluorescein and radioactive chromium--a clinical comparison of methods.

OBJECTIVE: There exists no method so far for the determination of circulating blood volume as an important parameter of circulatory function widely usable under clinical conditions. Therefore, the present study was designed to investigate whether identical distribution spaces could be measured by two methods for blood volume determination using sodium fluorescein (SoF) and radioactively labelled red blood cells (51Cr*). DESIGN: Comparative study. SETTING: Operating theatre, recovery room, or intensive care unit of a university hospital. PATIENTS: 35 patients undergoing abdominal, urological or vascular surgery. INTERVENTIONS: Simultaneous determinations of blood volume using SoF and 51Cr* in the intra- and postoperative period. RESULTS: There were no significant differences between the calculated means of blood volume (4,445 vs. 4,407 ml), red cell volume (1,554 vs. 1,540 ml), and plasma volume (2,891 vs. 2,807 ml) for 51Cr*-vs. SoF-stained red blood cells. The coefficient of correlation between the two methods was r = 0.95. The mean percentage error was -0.6% between the two methods, the precision 5.6%. CONCLUSIONS: SoF-stained erythrocytes allow a determination of the same distribution space as the well-established radioactive method using 51Cr*. Therefore, SoF-staining may replace 51Cr* labelling of red blood cells for the determination of blood volume in patients.

Adult↗
PubMed1983

Fluorescein isothiocyanate as a cell marker for tracing lymphocyte circulation in sheep.

The use of fluorescein isothiocyanate (FITC) as a cell marker in ovine lymphocyte circulation studies was investigated. The effects of the label on lymphocyte function were assessed by lymphocyte blastogenesis, cell-mediated cytotoxicity and normal lymphocyte transfer reactions. Labelling lymphocytes in 0.05 mg FITC/ml for 10 min at 37 degrees C was found to be optimum. Circulation kinetics of FITC-labelled efferent lymph lymphocytes were monitored as they disappeared from peripheral blood following intravenous infusion and reappeared in the efferent lymphatic duct of the popliteal lymph node. No functional changes were detected in lymphocytes labelled with the optimal regimen.

Animals↗
PubMed1980

Short time bleaching of fluorescein isothiocyanate. A possible parameter for the specific binding of conjugates in immunofluorescence.

The fluorescence kinetics of fluorescein isothiocyanate (FITC)-antibody conjugates during short (0.01 sec) laser excitations were analyzed for possible information about the immunological specificity of binding to antigenic substrates in direct immunofluorescence assays with antigen-coated Sephadex beads. First results of these investigations suggest marked differences in the bleaching characteristics of specifically and nonspecifically bound FITC conjugates: FITC-anti-bovine serum albumin (BSA) and FITC-anti-rabbit immunoglobulin (Ig) were found to fade significantly more slowly when bound to the respective homologous antigen (anti-BSA to BSA, and anti-rabbit Ig to rabbit Ig) as compared to nonspecifically adherent anti-BSA to rabbit Ig, and anti-rabbit Ig to BSA. Possible implications of these data for discrimination of nonspecific staining in immunofluorescence are discussed.

Antigens↗
PubMed1986

Transcellular transport of fluorescein dextran through an arterial endothelial cell monolayer.

Transcellular transport of fluorescein dextran (FD) of various molecular weights (4K, 10K, 20K, 70K and 150K daltons) through porcine arterial endothelial cells cultured on a type I collagen gel supported by a dacron sheet was studied and compared with the transport of low density lipoprotein labeled with rhodamine B (RB-LDL) described previously (Hashida et al., Cell Struct. Funct. 11, 31-42, 1986). The rate of FD transport through the monolayer depended on the size of the FD. FD transport was not temperature-dependent and was not a saturable process. Our findings show that FD transport differs from RB-LDL transport which is temperature- and dose-dependent. The mechanism of the transport of FD is compared with that of RB-LDL.

Animals↗
PubMed1996

Inhibition of mitogen-induced changes in intracellular fluorescein fluorescence polarization of human peripheral blood lymphocytes by colchicine, vinblastine and cytochalasin B.

We have previously reported that the exposure of human peripheral blood lymphocytes (PBL) to a variety of stimulants caused rapid changes in intracellular fluorescein fluorescence polarization (IFFP) in the activated cells. In the present study we further analyzed possible mechanisms responsible for the changes in IFFP in PBL exposed to phytohaemagglutinin (PHA) and anti-CD3 antibody. By employing several agents which are known to affect the polymerization of the cytoskeleton we showed that both cytochalasin B, which regulates the microfilaments structure, and vinblastine and colchicine, which affect the microtubules, completely abolished the changes induced in IFFP of human PBL by both PHA and anti-CD3. This effect was dose dependent and was noted at concentrations ranging from 10 to 100 microM of cytochalasin B and 10 microM of vinblastine and colchicine. The effect of these cytoskeleton modulators occurred within 20 minutes after the initiation of activation with PHA. Our results indicate that activation with PHA and anti-CD3 causes early changes in the microtubules and microfilaments components of the cytoskeleton. The possible application of IFFP measurement in analyzing early changes in the cytoskeleton following cell activation is discussed.

Colchicine↗
PubMed1997

Polysaccharides as drug carriers: biodisposition of fluorescein-labeled dextrans in mice.

The biodisposition of fluorescein-labeled dextrans (FDs) with different molecular weights (MW = 4-500 kDa) was systematically examined in mice. After intravenous injection of FDs at a dose of 120 mg/kg, the levels of FDs in the blood circulation and in the various organs were measured fluorometrically. FDs with a molecular weight lower than 20 kDa showed poor hepatic distribution (2.1-3.7% of dose/g tissue) due to their rapid elimination from the blood circulation. FDs with higher molecular weights were appreciably distributed in the liver (18.9-24.0% of dose/g tissue) and accumulated there over a long period, whereas the FD levels in the other organs were almost negligible a few days after injection. The hepatic mean residence time of FDs ranged from 22.5 to 28.1 d. Partial depolymerization of FDs which accumulated in the liver was observed within 10 d after administration. The hepatic uptake clearance of FDs was decreased with an increase in molecular weight. A marked molecular weight dependency was also seen in the urinary and fecal excretions of FDs. An appreciable dose-dependency was demonstrated in the hepatic uptake of FDs (MW = 40 kDa), as well. The amount of hepatic uptake as a function of dose showed saturation kinetics and was analyzed by a Michaelis-Menten type equation. The apparent values of K(m) (dose) and Vmax (hepatic level) estimated were 116 +/- 5 mg/kg and 1.10 +/- 0.05 mg/g tissue, respectively.

Animals↗
PubMed2002

Retinal fluorescein contrast arrival time of young patients with the hepatosplenic form of the Schistosomiasis mansoni.

Schistosoma mansoni is responsible for lesions that can alter the hemodinamic of the portal venous circulation, lung arterial and venous sistemic systems. Therefore, hemodinamic changes in the ocular circulation of mansonic schistosomotic patients with portal hypertension and hepatofugal venous blood flow is also probable. The purpose of this study was to determine the fluorescein contrast arrival time at the retina of young patients with the hepatosplenic form of schistosomiasis, clinically and surgically treated. The control group included 36 non schistosomotic patients, mean age of 17.3 years, and the case group was represented by 25 schistosomotic patients, mean age of 18.2 years, who were cared for at The University Hospital (Federal University of Pernambuco, Brazil), from 1990 to 2001. They underwent digital angiofluoresceinography and were evaluated for the contrast arrival time at the early retinal venous phase of the exam. Both groups were ophthalmologically examined at the same hospital (Altino Ventura Foundation, Recife, Brazil), using the same technique. There was retardation of the retinal contrast arrival time equal or more than 70 sec in the eyes of three schistosomotic patients (12%) and in none of the control group, however, the mean contrast arrival time between the two groups were not statistically different. These findings lend support to the hypothesis that there could be a delay of the eye venous blood flow drainage.

Adolescent↗
PubMed1977

Blood supply of human gingiva following periodontal surgery. A fluorescein angiographic study.

This study demonstrates changes in the gingival vascular supply of humans following various periodontal surgical procedures. A special system was used to photograph circulatory changes following an i.v. injection of sodium fluorescein to visualize blood supply. The results of this study suggest that the following concepts are important in the design of periodontal flaps. 1. Flaps should be broad enough at their base to include major gingival vessels. 2. A flap's length to width ratio should not exceed 2:1. 3. Minimal tension should be produced by suturing techniques and the tissue should be managed gently during the surgical procedure. 4. Partial thickness flap preparations to cover avascular areas should not be too thin so that more blood vessels are included in them. 5. The apical portion of periodontal flaps should be full thickness when possible.

Adult↗
PubMed1996

Detection of apoptosis at the single-cell level by direct incorporation of fluorescein-dUTP in DNA strand breaks.

Apoptosis induced in different cell lines can be detected and quantified in one step. Direct labeling of apoptotic cells (DLAC) was performed by incorporation of fluorescein-dUTP (F-dUTP) in DNA strand breaks by terminal deoxynucleotidyl transferase (TdT). Nick-end-labeling using F-dUTP obviates the need for second-step revelation reagents without reducing the specificity of detection. Cells were analyzed by microscopy or flow cytometry for objective quantification of apoptotic cells in controlled dilution samples. Furthermore, we demonstrate that DLAC is compatible with surface labeling by monoclonal antibodies, allowing dual-color analysis. The data presented here illustrate the simplicity and potential of this method, which allows the preservation of fragile cells and the possibility of combining apoptosis detection with immunostaining.

Apoptosis↗
PubMed1993

An improved method for perforated patch recordings using nystatin-fluorescein mixture.

This paper describes an improved method for solubilizing nystatin in an aqueous solution without the aid of organic solvents. The patch pipette was filled with a solution of nystatin and fluorescein sodium mixed in a molar ratio of 1:10. The success rate of perforated patch recordings was substantially improved, and the access resistance of 20-40 M omega was readily achieved.

Action Potentials↗
PubMed1982

Selective binding of fluoresceinated-avidin to A-cells of sectioned pancreas.

Fluoresceinated-avidin (FITC-avidin) was observed to bind specifically to a subset of pancreatic islet cells in sections of both human and rat pancreas. FITC-avidin binding was inhibited by excess unlabeled avidin, and by biotin, but not by glucagon, somatostatin, or insulin. Labeling of islets with anti-insulin, anti-glucagon, anti-somatostatin, and anti-human pancreatic polypeptide antibodies showed the avidin binding subset to correspond to islet cells identified by anti-glucagon antibody. Conversely, avidin reacted with no insulin, somatostatin, or cells containing HPP. We conclude that avidin localizes specifically to A-islet cells. Binding may be to a biotin-containing enzyme within the A-cells, but the precise molecular site of binding is currently unidentified.

Adult↗
PubMedDate not supplied

Blood flow measurements in rabbit sinus mucosa. A comparison between fluorescein flowmetry and blood flow measurements with microspheres and Rb86Cl.

The blood flow of the sinus mucosa was studied in 14 rabbits of the New Zealand White strain. The blood flow was determined by fluorescein flowmetry and the values were compared with those obtained from the same sinus mucosa with use of Sn113 radioactively labelled microspheres and with Rb86Cl. One sinus cavity in each animal received nose drops prior to the blood flow measurement. The blood flow index in the sinus mucosa was 0.039 +/- 0.019 density units Xs-1 and was significantly reduced to 0.016 +/- 0.011 density units Xs-1 by administration of nose drops. Blood flow in the sinus mucosa was 1.0 +/- 0.53 ml X min-1 X g-1 as measured with microspheres and 0.52 +/- 0.12 ml X min-1 X g-1 with the Rb86Cl method. Following administration of nose drops the values were reduced to 0.29 +/- 0.13 and 0.22 +/- 0.07 ml X min-1 X g-1 respectively. There was a significant difference in blood flow obtained with the Rb86Cl and microsphere methods in the sinus mucosa without decongestion. This might be explained by possible shunting of blood in the mucosa due to hyperaemia caused by the surgical trauma to the sinus.

Animals↗