Chemiluminescent Solution Research Articles

An Antibody Delivery System for Regulated Expression of Therapeutic Levels of Monoclonal Antibodies In Vivo

An Antibody Delivery System for Regulated Expression of Therapeutic Levels of Monoclonal Antibodies In Vivo

Up-regulation of the Angiotensin II Type 1 Receptor by the MAS Proto-oncogene Is Due to Constitutive Activation of Gq/G11 by MAS

Coexpression of the MAS proto-oncogene with the angiotensin II type 1 (AT(1)) receptor in CHO-K1 cells has been reported to increase the number of [(3)H]angiotensin II-binding sites, although MAS does not bind [(3)H]angiotensin II. In HEK293 cells stably expressing AT(1) receptor-cyan fluorescent protein (CFP), MAS-yellow fluorescent protein (YFP) expression from an inducible locus caused strong up-regulation of AT(1) receptor-CFP amounts and [(3)H]angiotensin II binding levels. The time course of AT(1) receptor-CFP up-regulation was also markedly slower than that of induction of MAS expression. These effects were not mimicked by induced expression of I138D MAS-YFP, a mutant unable to cause constitutive loading of [(35)S]guanosine 5'-O-(thiotriphosphate) onto the phospholipase Cbeta-linked G protein Galpha(11). Protein kinase C (PKC) inhibitors and the selective Galpha(q)/Galpha(11) inhibitor YM-254890 fully blocked MAS-induced up-regulation of AT(1) receptor-CFP amounts, whereas the PKC activator phorbol 12-myristate 13-acetate produced strong up-regulation of AT(1) receptor-CFP without induction of MAS-YFP expression and in the presence of I138D MAS-YFP. The C-terminal tail of the AT(1) receptor is a known target for PKC-mediated phosphorylation. In cells stably expressing a C-terminally truncated version of the AT receptor, induction of MAS expression did not up-regulate the truncated construct levels. These data demonstrate that the ability of MAS to up-regulate AT(1) receptor levels reflects the constitutive capacity of MAS to activate Galpha(q)/Galpha(11) and hence stimulate PKC-dependent phosphorylation of the AT(1) receptor.

An Improved Method for the Flow-Injection Determination of Iodine Using the Luminol Chemiluminescence Reaction in a Reversed Micellar Medium of Cetyltrimethylammonium Chloride in 1-Hexanol-Cyclohexane

To eliminate the use of chlorinated hydrocarbons, we have improved the method for the flow-injection (FI) determination of iodine based on the chemiluminescence reaction of iodine with luminol in a chloroform-free reversed micellar medium of the surfactant cetyltrimethylammonium chloride (CTAC) using a mixture of 1-hexanol-cyclohexane as a bulk solvent. The FI procedure used simply involves the mixing of an iodine solution in cyclohexane with the chemiluminescent reagent solution of luminol in the reversed micellar medium of CTAC in 0.38 M 1-hexanol in cyclohexane/water (buffered with sodium carbonate). The optimum conditions for the iodine determination were evaluated and a detection limit (DL) of 0.05 ng cm(-3) iodine was achieved. The calibration graph obtained was linear with a dynamic range from the DL to 10 ng cm(-3) iodine. The relative standard deviations (n=5) observed at all concentrations within the linear range were less than 2.5%. The improved FI method is rapid and equally sensitive like the original one and was found to be suitable for the determination of trace iodine.

The C-terminal Activating Region 2 of the Epstein-Barr Virus-encoded Latent Membrane Protein 1 Activates NF-κB through TRAF6 and TAK1

Epstein-Barr virus (EBV)-encoded latent membrane protein 1 (LMP1) is oncogenic and indispensable for EBV-mediated B cell transformation. LMP1 is capable of activating several intracellular signaling pathways including the NF-kappaB pathway, which contributes to the EBV-mediated cell transformation. Two regions in the cytoplasmic carboxyl tail of LMP1, namely C-terminal activating regions 1 and 2 (CTAR1 and CTAR2), are responsible for NF-kappaB activation, with CTAR2 being the main NF-kappaB activator. Although the CTAR1-mediated NF-kappaB activation was previously shown to be TRAF3-dependent, we showed here that the CTAR2-mediated NF-kappaB activation is mainly TRAF6-dependent but TRAF2/5-independent. In contrast to the interleukin-1 receptor/toll-like receptor-mediated NF-kappaB pathways, the CTAR2-mediated NF-kappaB pathway does not require MyD88, IRAK1, or IRAK4 for TRAF6 engagement. Furthermore, we showed that TAK1 is required for NF-kappaB activation by LMP1. Thus, LMP1 utilizes two distinct pathways to activate NF-kappaB: a major one through CTAR2/TRAF6/TAK1/IKKbeta (canonical pathway) and a minor one through CTAR1/TRAF3/NIK/IKKalpha (noncanonical pathway).

Galectin-3 Modulates MUC2 Mucin Expression in Human Colon Cancer Cells at the Level of Transcription via AP-1 Activation

Galectin-3 and MUC2 intestinal mucin each have been correlated with the malignant behavior of colon cancer cells. Galectin-3 modulates expression of MUC2 protein, but the specific regulatory mechanisms are unknown. This study sought to determine how galectin-3 increases MUC2 expression. Galectin-3 levels in human colon cancer cells of high and low metastatic ability were manipulated via expression of galectin-3 complementary DNA in sense or antisense orientation. Galectin-3 and MUC2 protein expression were determined by Western analysis and immunocytochemistry. Transient transfections of promoter reporter constructs were used to monitor MUC2 transcription and AP-1 activity. Electrophoretic mobility shift assays, site-directed mutagenesis, and chromatin immunoprecipitation were used to monitor the participation of AP-1 in MUC2 transcription. Alterations in galectin-3 levels correlated with both MUC2 protein expression and transcription. By using MUC2 promoter constructs of different lengths, galectin-3 responsiveness was found between 1500 and 2186 bp upstream of the translation start site, a region that contains 1 consensus AP-1 binding site. AP-1 activity paralleled MUC2 transcription in the different cell lines. Mutation in the AP-1 site markedly decreased MUC2 promoter activity, and MUC2 transcription was inhibited by cotransfection with a dominant-negative AP-1 vector. Electrophoretic mobility shift assays, co-immunoprecipitation, and chromatin immunoprecipitation analyses suggested an association between galectin-3, c-Jun, and Fra-1 in forming a complex at the AP-1 site on the MUC2 promoter. Galectin-3 up-regulation of MUC2 transcription occurs at the level of transcription through AP-1 activation. This may have important implications for understanding the role of galectin-3 and MUC2 in colon cancer metastasis.

Up-regulation of Human myo-Inositol Oxygenase by Hyperosmotic Stress in Renal Proximal Tubular Epithelial Cells

myo-Inositol oxygenase (MIOX) catalyzes the oxidative cleavage of myo-inositol (MI) to give d-glucuronic acid, a committed step in MI catabolism. d-Glucuronic acid is further metabolized to xylitol via the glucuronate-xylulose pathway. Although accumulation of polyols such as xylitol and sorbitol is associated with MI depletion in diabetic complications, no causal relationship has been established. Therefore we are examining the role of MIOX in diabetic nephropathy. Here we present evidence that the basis for the depletion of MI in diabetes is likely to be mediated by the increased expression of MIOX, which is induced by sorbitol, mannitol, and xylitol in a porcine renal proximal tubular epithelial cell line, LLC-PK1. To understand the molecular mechanism of regulation of MIOX expression by polyols, we have cloned the human MIOX gene locus of 10 kb containing 5.6 kb of the 5' upstream sequence. Analysis of the 5' upstream sequence led to the identification of an osmotic response element (ORE) in the promoter region, which is present approximately 2 kb upstream of the translation start site. Based on luciferase reporter and electrophoretic mobility shift assays, polyols increased the ORE-dependent expression of MIOX. In addition, we demonstrate that the activity of the promoter is dependent on the binding of the transcription factor, tonicity element-binding protein, or osmotic response element-binding protein, to the ORE site. These results suggest that the expression of MIOX is up-regulated by a positive feedback mechanism where xylitol, one of the products of MI catabolism via the glucuronate-xylulose pathway, induces an overexpression of MIOX.

Generation of an Active Intermediate(s) during the Storage of a Peroxyoxalate Chemiluminescence Reagent Solution under the Presence of Strong Carboxylic Acids

Catecholamines have been measured using a fully-automated HPLC-ethylenediamine condensation reaction-peroxy-oxalate chemiluminescence (CL) detection system with both high sensitivity and selectivity. When a CL solution containing trifluoroacetic acid was kept at room temperature, 4°C or − 20°C, and then used for the CL detection of catecholamines, the CL intensity was significantly increased. With the solutions stored at − 20°C, the maximum CL intensity was observed, even after being stored for one year. This increase in the CL intensity was observed with CL solutions prepared using either bis(2,4,6-trichlorophenyi)oxalate (TCPO) or bis[4-nitro-2-(3,6,9-trioxadecyloxycarbon-yl)phenyl]oxalate (TDPO) in either dioxane/ethyl acetate or acetonitrile. A certain strong carboxylic acid in the CL solution, such as trifluoroacetic acid, trichloroacetic acid or heptafluorobutyric acid, was necessary in order to increase the CL intensity. This increase in the CL intensity was also observed even after decomposition of all the oxalate in the CL solution, suggesting that an active intermediate(s) for generating CL is produced in a strongly acidic solution during storage.

A kinetic chemiluminescence study of the antioxidants evolved from polymeric materials into the gaseous phase

Abstract Evolution of efficient peroxyl (ROO) acceptors from polymers into the gaseous phase was studied. The oxygen- containing gas was passed over a polymer sample and bubbled through a chemiluminescent probe solution of a hydrocarbon (RH: diphenylmethane, ethylbenzene or cyclohexane). Chemiluminescence was excited on dis- proportionation of ROO and chemically quenched due to the reaction of ROO with dissolved acceptors. Acceptors were detected at 290–350 K over polyolefins, black and silicone rubber, linoleum and rubber sediments on the leaves of plants, etc. The samples exhibit increased ability or acquire the ability to generate acceptors after treatment to induce their oxidation. Acceptors have been detected in the ambient air; the probable sources are polymeric fabrics, parts and waste, etc. in the environment. The concentration of acceptors may reach 10 -7 –10 −8 M in the air, which decreases on breathing. The rate constant for the acceptor-ROO reaction (approximately 10 9 M −1 s −1 ) is close to the diffusion-limited rate, whereas reactions of acceptors with hydrocarbons, molecular oxygen, strong hydrogen donors and stable free radicals (galvinoxyl) are very slow (less than 10 2 M −1 s −1 ) as is the self-reaction of acceptors in the gaseous phase (5 x 10 2 M −1 s −1 ). These unusual kinetic properties can be explained if the acceptors are assumed to be radical products of polymer destruction with bulky substituents at a partly alelocalized electron centre.

Chemiluminescence high performance liquid chromatography of corticosteroids using lucigenin as post‐column reagent

A chemiluminescence high performance liquid chromatographic method for the determination of corticosteroids and tetrahydrocorticosteroids has been developed. Corticosteroids and their metabolites extracted from urine samples were separated using an ODS column and a mixture of methanol + water + 0.01 M sodium acetate solution (70:30:5) as eluent. The eluent from the column was mixed with the chemiluminescent solution containing lucigenin and Triton X-100 and a 0.28 M KOH solution by pumps and monitored by a chemiluminescence detector. No interference was encountered and the method is both precise and reproducible.

Chemiluminescence and Hematoporphyrin Derivative: a Novel Therapy for Mammary Adenocarcinomas in Mice

A Chemiluminescent System (CLS), using a Peroxyoxalate chemiluminescent solution (PCs), together with Hematoporphyrin derivative (HpD) Photofrin II., were utilized in the treatment of transplanted mammary adenocarcinomas in C3H/HeJ female mice. Tumor bearing animals aged 2-4 months were divided into five groups; Group I was the control. Groups 2 and 4 compared the effectiveness of both reagents HpD and PCs which were administered by intratumor injections fractionated over a 96 hour period. Groups 3 and 5 compared the effectiveness of PCs alone. Tests of the PCs were conducted with and without the presence of luminescence. Fifty-three percent of the animals in Group 4 and 47% of the animals in Group 2 remained tumor free 120 days after the completion of treatment. Thirty percent of the animals in Groups 2 and 4 survived one year without tumor recurrence. The results of this study suggest that a chemical light system can be a viable alternative in Photodynamic Therapy (PDT) to laser light for the activation of HpD and treatment of cancer.

Lyoluminescence mechanism of additively and gamma coloured alkali halides in fluorescent and chemiluminescent solutions

Lyoluminescence of gamma irradiated and additively coloured NaCl, NaBr, KCl and KBr crystals when dissolved in fluorescent and chemiluminescent aqueous solutions is investigated. Spectral analysis of the emitted light has shown that lyoluminescence spectra are similar to the fluorescence spectra of these solutions. Luminescence takes place when a fluorescent acceptor is directly excited by a liberated F-centre (hydrated electron e - aq) or indirectly by an energy transfer from a released excited halide ion ∥X -∥ ∗ (solvated hole after recombination with hydrated electron). Oxygen, in general, has a marked quenching effect on luminescence. In chemiluminescent systems, its presence is essential to provoke luminescence in a sequence of events leading to a fluorescent end product.

Magnetic field effects on chemiluminescent fluid solutions

The effect of a magnetic field on the intensity of fluorescence from chemiluminescent reactions occurring in fluid solutions is calculated. The calculation first considers pairs of triplet molecules rotating in each other's vicinity and calculates the effect of a magnetic field on the rate at which the overall singlet state is populated. The field diminishes this rate, as in the solid-state situation. The triplets are then allowed to diffuse apart, and the process of populating the overall singlet state of the pair is treated as a relaxation process occurring during the diffusive trajectory. In this case too at high fields the intensity diminishes. The calculations are repeated for triplet-doublet quenching, and, in accord with the solid-state results, the intensity is enhanced at high fields because the quenching rate for doublet-triplet collisions is diminished, and the resultant fluorescence arises via triplets which escape abortive D-T encounters. Explicit expressions involving the dynamical parameter...

The Spectra of the Chemiluminescence, Fluorescence and Absorption of Lucigenin and Its Electron Spin Resonance

Abstract In order to study the mechanism of the chemiluminescence of lucigenin which was emitted with hydrogen peroxide in an alkaline solution, the color and the spectrum of the chemiluminescence and fluorescence, the spectrum of absorption, and the electron spin resonance were investigated. The color of the chemiluminescence was found to vary from green to blue with a decrease in the concentration of lucigenin. The spectrum of the blue chemiluminescence spread over only a visible region of 420—650 m/μ, with a peak at 485 mμ. With an increase in the concentration of lucigenin, the peak shifted to 510 m/μ or longer, corresponding to the green color of the chemiluminescence. This shift is due to self-absorption by lucigenin. The fluorescence spectrum of lucigenin in aqueous sodium hydroxide showed a peak at 508 mμ. The peak gradually disappeared, and the spectrum eventually showed new peaks at 435 and 450 m/μ which almost agreed with the peaks of the fluorescence spectrum of 10-methylacridone. Lucigenin exhibited an electron spin resonance of a single peak (g-value 2.004) in a solid state. These results show that the chemiluminescence of lucigenin is neither of the fluorescence of lucigenin nor that of 10-methylacridone yielded in the chemiluminescent solution of lucigenin and that the mechanism of the chemiluminescence is likely to involve a free radical intermediate.

Mass-transfer measurements with the technique of electrochemiluminescence

When a potential is applied between two platinum electrodes immersed in a chemiluminescent solution a blue glow appears at the surface of the anode. The parameters affecting the intensity of the glow are investigated and the limiting current conditions are obtained. In low-Reynolds-number flows, local intensities of the glow are measured on flat plates and around the circumference of a circular cylinder by the current output of a photomultiplier tube. It is found that, at limiting currents, the intensity of the glow is proportional to the calculated mass-transfer rate to the surface of the anode, and a relationship is obtained between the current output and the mass-transfer rate for the experimental system employed.

Use of electrochemiluminescence in visualizing separated flows

When a potential is applied between two electrodes immersed in a flowing chemi-luminescent solution a blue glow appears at the surface of the anode. This glow may be used to observe the behaviour of liquid flows past solid surfaces. An electrochemical system suitable for generating the glow is described. Photographic studies of separated flows past cylinders, flat plates and cones are presented showing the application of the technique of electrochemiluminescence to flow visualization.

A chemiluminescence method for determining ozone

A method for determining ozone is described which is characterised by the direct recording and automatic determination of ozone within a wide range of concentrations. The development of this method is based on the use of a chemiluminescent solution that is stable, and shows a linear relationship between the light emitted and the ozone concentration. A combination of rhodamine B with gallic acid in ethanol is satisfactory in operation and does not itself emit light. The electronic instrumentation used is relatively simple. Other methods of ozone analysis based on this principle meet with much difficulty, owing to the direct oxidation of the chemiluminescent compound. The present method, by contrast, involves the use of gallic acid as an ozone acceptor, and rhodamine B, which remains unchanged during the measurement, as a photon emitter. Observations made with an oscillograph of the light emitted by single bubbles of ozonised air passing through the chemiluminescent solution give valuable information about the responsetime of the system.

Use of Electrochemiluminescence in the Measurement of Mass Transfer Rates

When a potential is applied between two platinum electrodes immersed in a flowing chemiluminescent solution, a blue glow appears at the surface of the anode. An electrochemical system suitable for generating the glow is described. Experimental results are presented showing the effects of the parameters on the intensity of the glow. It is shown that for a given potential and a given solution the light intensity is governed solely by mass transfer of the chemiluminescent substance to the surface of the anode.

Spin-orbit Coupling and Intermolecular Energy Transfer

RECENTLY1,2 we reported on the intermolecular energy transfer in chemiluminescent solutions, an excited product of the reaction being a donor and anthracene derivatives being acceptors (activators). The activated chemiluminescence spectra were identical with the fluorescence spectra of the activators, indicating that the singlet state of the activator is the excited one2. A dependence of the chemiluminescence intensity on the activator concentration was used for estimating the ratio kPA/fP (kPA, transfer constant, fP, emission probability of the excited product, P′ (Fig. 1)). The relative values of the kPA's were found to be greater the more halogens were introduced in the activator molecule and the greater was the atomic weight of the substituent: in this communication these features of the phenomenon are regarded as evidence for the spin-orbit coupling in the activator molecule.

Secondary Processes in Chemiluminesccnt Solutions

EXCITATION energy transfer and quenching of excited states are known to be of importance in many phenomena, for example, in photochemistry1, photoluminescence2, radioluminescence3, radiolysis4. Evidence is presented in this communication that processes of the kind may occur in chemiluminescent solutions as well.