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At least 811 records · Page 45Linked to original sources
PubMed1978

Conjugation of coxsackievirus type B1-B6 immunoglobulins with fluorescein isothiocyanate by a "reversed" dialysis method.

Immunoglobulins from antisera to coxsackievirus B types 1--6 were labeled with fluorescein isothiocyanate by a "reverse" dialysis method of conjugation. Conjugates thus obtained were labeled at reproducible ratios of fluorescein to protein with weight-weight ratios ranging from 5.0 to 7.1 and estimated molar ratios ranging from 2.1 to 2.9. Conjugates were tested on cover-slip HeLa cell cultures by the direct method of staining. Two types of specific immunofluorescence were observed: intensely fluorescent perinuclear masses and discrete foci of bright fluorescence scattered throughout the cytoplasm. Titers of homotypic conjugates varied from 1:40 to 1:160. Heterotypic staining, consisting of a diffused hazy fluorescence, was observed only at the highest concentrations of conjugate and not above the 1:10 dilution. This technique proved to be specific and sensitive for the detection of group B coxsackievirus antigens in HeLa cells but failed in specific detection of the same antigens in samples of the myocardium obtained by biopsy of three patients clinically ill with idiopathic myocarditis.

Antibodies, Viral↗
PubMed1983

Polyuria in experimental intrahepatic cholangitis induced by alpha-naphthyl-isothiocyanate.

Alpha-naphthyl-isothiocyanate (ANIT)-induced intrahepatic cholangitis was associated with significant polyuria in rats. The urine output in the experimental rats was about two and a half to four fold higher than that in the controls. The polyuria was accompanied by polydypsia and disappeared when water intake was limited and controlled. The glomerular filtration rate and renal histology remained intact. Dilution and concentration capacities were preserved and the response to exogenous anti-diuretic hormone was intact. Following water deprivation, the water and electrolyte contents of the renal medulla and papilla were similar in both experimental and control rats. The excretion of a salt-load in ANIT-treated rats was delayed. It is concluded that the polyuria in ANIT-treated rats is secondary to polydypsia. The finding of preserved dilution and concentration capacities in this experimental model contrasts to that in other experimental models of hepatobiliary disease.

1-Naphthylisothiocyanate↗
PubMed1993

The inhibitory effect of SA3443, a novel cyclic disulfide compound, on alpha-naphthyl isothiocyanate-induced intrahepatic cholestasis in rats.

1. We investigated the effect of SA3443, a novel cyclic disulfide compound, on alpha-naphthyl isothiocyanate (ANIT)-induced intrahepatic cholestasis in rats. 2. SA3443 given orally at doses of 100 or 300 mg/kg, three times at 4h intervals, dose-dependently suppressed the elevation of serum total bilirubin, alkaline phosphatase activity and transaminase activities induced by administration of ANIT (80 mg/kg) 3h before the second dosages of SA3443. 3. SA3443 also significantly inhibited the reduction of bile flow in the ANIT-treated rats. 4. These findings indicated that SA3443 had a markedly inhibitory effect on ANIT-induced intrahepatic cholestasis in rats.

1-Naphthylisothiocyanate↗
PubMed1988

Fluorescein Isothiocyanate-Labeled Lectin Analysis of the Surface of the Nitrogen-Fixing Bacterium Azospirillum brasilense by Flow Cytometry.

The cell surface of Azospirillum brasilense was probed by using fluorescein isothiocyanate (FITC)-labeled lectins, with binding determined by fluorescence-activated flow cytometry. Cells from nitrogen-fixing or ammonium-assimilating cultures reacted similarly to FITC-labeled lectins, with lectin binding in the following order: Griffonia simplicifolia II agglutinin > Griffonia simplicifolia I agglutinin > Triticum vulgaris agglutinin > Glycine max agglutinin > Canavalia ensiformis agglutinin > Limax flavus agglutinin > Lotus tetragonolobus agglutinin. The fluorescence intensity of cells labeled with FITC-labeled G. simplicifolia I, C. ensiformis, T. vulgaris, and G. max agglutinins was influenced by lectin concentration. Flow cytometry measurements of lectin binding to cells was consistent with measurements of agglutination resulting from lectin-cell interaction. Capsules surrounding nitrogen-fixing and ammonium-assimilating cells were readily demonstrated by light and transmission electron microscopies.

Journal Article↗
PubMed1991

Analysis of free amino acids in microbially colonized sandstone by precolumn phenyl isothiocyanate derivatization and high-performance liquid chromatography.

A fast, sensitive method for extraction and analysis of soluble free amino acids from microbially colonized sandstone is described. After precolumn phenyl isothiocyanate (PITC) derivatization, the PITC-amino acids were identified and quantified by reversed-phase high-performance liquid chromatography. This kind of analysis could be used to elucidate the role and function of amino acids in the nutrition of epi- and endolithic microorganisms active in biological weathering processes.

Journal Article↗
PubMed1968

Antifungal activity of isothiocyanates and related compounds. 3. Derivatives of biphenyl, stilbene, azobenzene, and several polycondensed aromatic hydrocarbons.

This paper presents the results of a study on the antifungal activity of isothiocyanates-derivatives of biphenyl (group "A"), of stilbene ("B"), of azobenzene and benzeneazonaphthalene ("C"), of naphthalene ("D"), and of further polycondensed aromatic hydrocarbons ("E"). From a total of 48 investigated compounds, antifungal activity was observed only in A and D group compounds. B, C, and E group derivatives are extremely insoluble in water, and the molecules are very large; as a result, they probably cannot pass into spores or mycelium of fungi. Thus, the -NCS group cannot manifest its reactivity.

Antifungal Agents↗
PubMed1972

Bacterial degradation of benzyl isothiocyanate.

Bacteria that degrade benzyl isothiocyanate to benzylamine and hydrogen sulfide were isolated from papaya pulp homogenate by enrichment culture techniques. These organisms were identified as members of Enterobacter cloacae.

Bacteriological Techniques↗
PubMed1973

Rapid batch method for the preparation of fluorescein isothiocyanate-conjugated antibody.

A rapid, reproducible, and relatively simple method for the preparation of large quantities of fluorescein isothiocyanate-conjugated antibody is presented. Tagged globulins with fluorochrome-protein ratios of 1 and 2 were eluted from diethylaminoethyl-cellulose in batch form by using sodium phosphate-buffered 0.1 M and 0.2 M saline, respectively. The intensity and specificity of the fluorescence due to this antibody was quite high, as determined by the ability of untagged antibody to block the immunological reactivity of the fluorescent antibody and by the lack of fluorescence of antigenically unrelated material when treated under identical conditions.

Ammonium Sulfate↗
PubMed1967

Evaluation of fluorescein isothiocyanate-labeled whole antiserum in the immunofluorescent identification of microorganisms.

Portions of a whole antiserum to Histoplasma capsulatum were reacted with amounts of fluorescein isothiocyanate (FITC) that ranged from 50 to 400 mug/mg of protein. Portions of the globulin from the same antiserum were reacted with amounts of FITC that ranged from 12.5 to 50 mug of FITC per mg of protein. The globulin conjugates (postlabeled globulins), the whole serum conjugates, and the globulins from the whole serum conjugates (prelabeled globulins) were compared with respect to their fluorescein-protein (F:P) ratios and fluorescent-antibody (FA) activities. The whole serum sample treated with 50 mug of FITC per mg of protein was least reactive in FA tests, and its globulin had the lowest F:P. All other conjugates had globulins with F:P ratios that were considered to be adequate for high FA activity. It was found, however, that the prelabeled globulins were considerably less reactive than the postlabeled globulins or the whole serum conjugates. A larger amount of brightly staining reagent per milliliter of original serum could be obtained from labeled whole serum than from postlabeled globulin. Lissamine-rhodamine conjugated to bovine serum albumin (LRBSA) was evaluated as a counterstain to be used in conjunction with FITC-labeled whole antisera. The counterstain was effective in masking nonspecific FITC fluorescence in Formalin-fixed tissues and in culture smears of fungi. Masking was incomplete in culture smears of a bacterium and in blood smears containing a protozoan.

Bacteriological Techniques↗
PubMed1975

Physicochemical and serological characteristics of respiratory virus fluorescein-isothiocyanate conjugates for fluorescent-antibody diagnosis.

Fluorescein-isothiocyanate (FITC) conjugates were prepared by improved methods from standard reference antisera to influenza A and B, mumps, parainfluenza 1, 2, 3, and 4, herpesvirus, respiratory syncytial virus, and adenovirus hexon. The antisera, prepared in a variety of animals, were fractionated three times with selected optimal concentrations of ammonium sulfate and yielded gamma globulins of adequate purity for conjugation with FITC. Conjugates containing optimal fluorescein-to-protein ratios of between 5 and 10 were produced in 2 h by dialysis labeling. Serological titers of each antiserum and conjugate were determined by complement fixation, hemagglutination-inhibition, serum neutralization, and indirect hemagglutination tests where appropriate. When corrected for dilution, the serological titers of the FITC conjugates were identical to those of the starting antisera. The fluorescent-antibody staining titers correlated well with one of the serological parameters of the original serum. The conjugates stained homologous antigens specifically and were free of nonspecific staining at the working dilution. Undesired staining of host cells which was a problem with some of the conjugates produced from sera containing cellular antibodies was removed by absorption with packed cells. These physicochemical and serological findings were then used as a guide in preparing high quality reagents for fluorescent-antibody identification of respiratory viruses.

Adenoviridae↗
PubMed1982

Evaluation of a solid-phase immunoassay with fluorescein isothiocyanate-conjugated heterogeneous or monoclonal antibodies for identification of virus isolates, with influenza virus as a model.

A solid-phase immunofluorescence assay was evaluated for the identification of viruses isolated in tissue culture, with influenza virus as a model. Purified immunoglobulin G (IgG) from hyperimmune rabbit sera specific for contemporary strains of influenza A or B was covalently attached to microscopic plastic beads to capture virus. Fluorescein isothiocyanate (FITC)-conjugated antibodies of different specificities were then reacted with bound antigen, and the resulting complexes were quantified in a suitable filter fluorometer. The assay, with appropriately absorbed FITC-conjugated second antibody, reliably identified virus present in harvests from cell cultures infected with clinical specimens. For influenza A (H1N1) virus, sensitivity of detecting antigen was about 8- to 32-fold less when an FITC-conjugated monoclonal Igg antibody pool specific for epitopes in three different antigenic sites on influenza hemagglutinin was used as the second antibody as compared to when IgG from hyperimmune sera specific for virus or its components was used as the second antibody. The immunofluorometric assay provides a method for quantitative detection of viral antigen in tissue culture fluids and objective identification of virus type and subtype with FITC-conjugated reagents.

Animals↗
PubMed1976

Preparation of rabies fluorescein isothiocyanate-labeled immune globulin from mouse hyperimmune ascitic fluids.

Immunization conditions for the production of mouse immune ascitic fluids to be used for the preparation of rabies fluorescent antibody (FA) conjugate are presented. The use of optimal concentrations of ammonium sulfate for precipitation of gamma globulin resulted in a fraction consisting of 75% gamma globulin and 25% alpha-beta globulins with no detectable albumin. Dialysis labeling of the globulin fration with fluorescein isothiocyanate produced a specific rabies FA conjugate with negligible nonspecific background staining. This procedure represents a simple means of producing rabies FA conjugate.

Animals↗
PubMed1979

Effect of allyl isothiocyanate on plasma and urinary concentrations of some biochemical entities in the rat.

Allyl isothiocyanate (AITC) is a constituent of several plants of the family Cruciferae that are commonly used as food. This study investigated the effect of feeding AITC to male Sprague-Dawley rats on their plasma glucose and uric acid levels as well as on the urinary concentrations of glucose, 17-ketosteroids (17-KS), creatinine, and uric acid. Other test compounds included were thyroxine (T4) and thiouracil (TU). AITC caused a highly significant (P smaller than or equal to 0.01) depression in the plasma glucose and uric acid levels compared with the control. TU caused a significant depression only of the plasma glucose. T4, on the other hand, significantly increased the levels of both glucose and uric acid. The AITC-treated rats voided twice as much urine as the controls or those receiving TU or injected with T4. The 24-h excretion of glucose, uric acid, and creatinine was significantly (P smaller than or equal to 0.01) higher in animals fed AITC than in those consuming the control diet, while the excretion of 17-KS was significantly lower. Results on an equal urine volume basis showed that differences in the excretion of glucose and creatinine were related to differences in the urine volume. TU significantly depressed excretion of all the compounds but glucose. The effect of T4 on the excretion of 17-KS and uric acid resembled that of AITC and TU, thus showing that these compounds depressed the androgenic function of the animal.

17-Ketosteroids↗
PubMed2005

N-acetylcysteine conjugate of phenethyl isothiocyanate enhances apoptosis in growth-stimulated human lung cells.

We previously showed that dietary treatment with the N-acetylcysteine conjugate of phenethyl isothiocyanate (PEITC-NAC) inhibited benzo(a)pyrene-induced lung tumorigenesis in A/J mice, and that tumor inhibition was associated with induction of activator protein-1 (AP-1) activity and stimulation of apoptosis in the lungs of mice. In the present study, we show that PEITC-NAC also induces apoptosis and AP-1 activity in human lung adenocarcinoma A549 cells, and that activation of AP-1 is important in PEITC-NAC induced apoptosis in these cells. PEITC-NAC induced AP-1 binding activity in A549 cells in a dose- and time-dependent manner; peak activity appeared at 10 micromol/L after 24 hours. At that time, flow cytometric analysis showed a sub-G1 peak, indicating that approximately 4.5% of the cells had undergone apoptosis. When wild-type c-jun cDNA was transfected into A549 cells, PEITC-NAC-mediated apoptosis was greatly increased in the c-jun-transfected cells compared with the control vector-transfected cells, based on cell morphology and analysis of DNA fragmentation. Furthermore, cells that were pretreated with 100 nmol/L 12-O-tetradecanoyl phorbol-13-acetate, and then treated with 25 micromol/L PEITC-NAC, underwent enhanced apoptosis compared with cells that were treated with PEITC-NAC alone; cells treated with 12-O-tetradecanoyl phorbol-13-acetate alone showed active cell growth without apoptosis. Bivariate flow cytometric analysis of DNA strand breaks versus DNA content showed that apoptosis induced by PEITC-NAC occurred predominantly in the G2-M phase. These findings suggest that growth-stimulated cells with an elevated basal AP-1 activity, i.e., A549 cells transfected with wild-type c-jun or treated with a tumor promoter, were more sensitive to PEITC-NAC-mediated apoptosis. The observation that PEITC-NAC induces apoptosis predominantly in growth-promoted cells, such as neoplastic cells, suggests a selective mechanism by which PEITC-NAC inhibits lung carcinogenesis.

Adenocarcinoma↗
PubMed1976

Flow microfluorometric system for screening gynecologic cytology specimens using propidium iodide-fluorescein isothiocyanate.

Seventy cervical cytology specimens have been screened by a xero resolution flow analyzer-sorter using propidium iodide and fluorescein isothiocyanate as fluorochromes for nucleus and cytoplasm, respectively. This system shows a 1% sensitivity for detection of abnormal cells using only crude visual data analysis. Screening of clinical specimens was performed on the instrument with a 5.8% false negative rate and a 11.8% false positive rate by comparison with routine visual cytologic evaluation of the same samples.

Adenocarcinoma↗
PubMed1976

Peroxidase and fluorescein isothiocyanate as antibody markers. A quantitative comparison of two peroxidase conjugates prepared with glutaraldehyde or periodate anda fluorescein conjugate.

Batches of rabbit anti-human immunoglobulin G antibodies were labeled either with horseradish peroxidase, using the two-step glutaraldehyde method or the periodate method, or with fluorescein isothiocyanate (FITC). The peroxidase conjugates were isolated by chromatography using two different gel types. The five types of conjugates thus obtained were standardized to the same amount of rabbit immunoglobulin G. The antibody activity, as estimated by means of single radial immunodiffusion and passive hemagglutination, and the enzyme activity, determined with orthodianisidine, were compared. The ultimate dilutions and absolute amounts of the five conjugates giving positive reactions were determined in direct and indirect immunohistochemical tests, using both cryostat sections of skin and the agarose bead model system. It appeared that during the peroxidase conjugation procedures there was a considerable loss of abtibody and enzyme activity, whereas in the FITC conjugation procedure the antibody activity remained intact. Neverthe less, peroxidase conjugates prepared with glutaraldehyde still gave positive staining reactions in equal or somewhat higher dilutions than the fluorescin conjugate did. The peroxidase conjugates prepared with periodate could not be diluted to the same extent. For the detection of antibodies by indirect immunohistochemical methods, the peroxidase conjugate, prepared with glutaraldehyde, was comparable to the FITC conjugate. The peroxidase conjugate, prepared with periodate, was less effective.

Aldehydes↗
PubMed1995

Spectra and fluorescence lifetimes of lissamine rhodamine, tetramethylrhodamine isothiocyanate, texas red, and cyanine 3.18 fluorophores: influences of some environmental factors recorded with a confocal laser scanning microscope.

We report on the spectra and fluorescence lifetimes of four commonly used fluorophores: lissamine rhodamine (LRSC); tetramethyl rhodamine isothiocyanate (TRITC); Texas Red; and cyanine 3.18 (Cy-3). Fluorescence lifetime recordings revealed that these spectrally overlapping fluorophores can be individually detected by their lifetimes, indicating that at least four fluorophores can be individually identified in discrete tissue domains by confocal microscopy. A further advantage of lifetime recordings is that fluorophores that emit light within the same wavelength band can be used and chromatic aberrations are therefore circumvented, thereby improving the spatial accuracy in imaging of multiple fluorophores. Low and high pH, respectively, tended to influence fluorophore emission spectra and fluorescence lifetime. IgG conjugation of the fluorophores tended to shift the spectra towards longer wavelengths and to change the fluorescence lifetimes. The IgG-conjugated form of the fluorophores may, when applied to tissue specimens, change the emission spectrum and lifetime. In addition, different tissue embedding procedures may influence fluorescence lifetime. These observations emphasize the importance of spectral and lifetime characterization of fluorescent probes within the chemical context in which they will be used experimentally. Changes in spectra and fluorescence lifetimes may be a useful tool to gain information about the chemical environment of the fluorophores.

Animals↗