bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of luminol‐dependent chemiluminescence from granule depleted neutrophil cytoplasts reveals two different light‐emitting mechanisms
Authors: Dahlgren Claes 
Published: May 2005

AbstractWhen neutrophil cytoplasts (granule‐free vesicles of cytoplasm enclosed by plasmalemma) were exposed to the chemotactic peptide formylmethionyl‐leucyl‐phenylalanine, no luminol‐dependent chemiluminescence was detected, despite a pronounced production of superoxide anions and hydrogen peroxide. Addition of purified myeloperoxidase (MPO) or human serum albumin (HSA) to the cytoplasts before the stimulus resulted in a chemiluminescence response. In contrast to the bimodal response obtained from normal PMNL, only a single peak of chemiluminescence was obtained from the cytoplasts responding to the peptide. The time‐course of the response obtained in the presence of albumin was more prolonged than the response obtained in the presence of MPO. Furthermore, the involvement of different oxidative metabolites in the MPO and the HSA systems, respectively, was demonstrated by the accumulated chemiluminescence effect obtained when MPO, but not HSA, was introduced in the measuring system after FMLP addition.From these results it can be concluded that there are at least two different light‐generating mechanisms in FMLP‐induced luminol‐dependent chemiluminescence of neutrophil cytoplasts. One of these is dependent on myeloperoxidase and possibly related to the myeloperoxidase‐hydrogen peroxide reaction, whereas the other one is hydrogen peroxide independent.
Stability of firefly luciferase in Tricine buffer and in a commercial enzyme stabilizer
Authors: Hall Marliese S. , Leach Franklin R. 
Published: May 2005

AbstractA solution of firefly luciferase in AuthentiZyme Enzyme Stabilizer® retains full activity when stored in an ice bath (0.5°C) during one day. These solutions have the advantage that no additional protein (other than the luciferase) is present, which is desirable for proteolytic digestion and protein dervatization experiments. For longer‐term experiments, firefly luciferase solutions in 0.05 mol/l Tricine buffer at pH 7.8, 10 mmol/l MgSO4, 1 mmol/l EDTA, and 1 mmol/I DTT which contain 100μg/ml of bovine serum albumin are stable for 6 weeks if frozen and thawed only once.
The transcription of bacterial luminescence is regulated by sigma 32
Authors: Ulitzur S. , Kuhn J. 
Published: May 2005

AbstractLuminescence in the marine bacterium, Vibrio fischeri, is regulated by a small molecule, the autoinducer. The transcription of the V. fischeri lux genes also requires a regulatory protein, (luxR), cAMP and CRP. We show that, apart from these components, the transcription of the PR lux operon is also controlled by the activity of σ32 (htpR protein). In luminescent Escherichia coli (E. coli/pChv1), as well as in different marine luminous bacteria and their naturally occurring dark (K) variants, the luminescence system can be induced by starvation under microaerophilic conditions. Heat shock also induces luminescence in htpR+ but not in htpR− strains of E. coli/pChv1.An htpR− mutant of E. coli containing pChv1 is very dim and its luminescence is not induced by starvation or heat shock. The addition of a plasmid bearing the gene for htpR+ into such cells restores their response to starvation and heat shock. Cells of wild type E. coli/pChv1 that have been starved or heat shocked respond to lower concentrations of V. fischeri inducer than untreated cells. These cultures also produce more extracellular inducer than untreated cells. Starvation, heat shock and the presence of σ32 do not induce luminescence in luxl deleted E. coli/pChv1 cells.SOS‐inducing agents advance the onset of luminescence in both htpR+ and htpR− strains but not in luxl deleted E. coli/pChvi cells.DNA sequencing of the luxR‐luxl region reveals the presence of a promoter region of the kind typical for σ32 at the beginning of the luxl gene. In addition we find a LexA protein‐DNA binding site in the non‐consensus sequence for the −35 region of the PR operon. It is proposed that the regulatory protein‐inducer complex displaces the LexA protein and allows the transcription of the right operon. SOS‐inducing agents result in proteolysis of LexA protein and advance the onset of luminescence. σ32 enhances the transcription from the PR operon and thus initiates a positive control circuit. It seems that σ32 is the major controlling element in determining the onset of luminescence both in vivo and in vitro.
Detection of genotoxicity of metallic compounds by the bacterial bioluminescence test
Authors: Ulitzur S. , Barak M. 
Published: May 2005

AbstractTwenty metallic compounds were assayed for their genotoxic mutagenic activity by the bioluminescence test restoration of the luminescence of dark mutant of the luminous bacterium Photobacterium fischeri). The activity of the metals was tested in a liquid medium as well as on a solid medium. K2Cr2O7, MnCl2, BeCl2, KH2AsO4, ZnCl2 and Na2WO4 showed strong activity in liquid medium while AgNO3, Cd(OOCCH3)2, CoCl2, CuCl2, HgCl2, Na2SeO3 and Pb(NO3)2 were more active in the solid medium test. BaCl2, Na2MoO4, NaAsO2, NiSO4, Na2SeO4, RbCl, and SnCl2 were not active in the bioluminescence test. The correlation between the genotoxic activity of the tested metallic compounds in the bioluminescence test and other bacterial tests for genotoxic agents as well as the correlation between these results and the carcinogenicity of these compounds is discussed.
Measurement of urinary somatomedin C by a chemiluminescent method
Authors: Orlando Claudio , Tode Bettina , Pinzani Pamela , Bassi Francesca , Messeri Gianni 
Published: May 2005

AbstractWe present a method for the measurement of the total Somatomedin C (SmC) content in human early morning urine samples after dialysis, extraction, and concentration. We modified a chemiluminescence immunoassay, previously developed for SmC determination in serum, for analysis of SmC in urine. Appropriate sensitivity was obtained by the preparation of a new chemiluminescent tracer (AEEI‐COOH‐SmC) and the optimization of a competitive non‐equilibrium immunoassay system which had a detection limit of 0.24 fmol SmC per tube.
Effects of granulocytes on human neuroblastoma cells measured by chemiluminescence and chromium‐51 release assay
Authors: Bruchelt Gernot , Handgretinger Rupert , Kimmig Astrid , Goeke Barbara , Siedner Ruben , Reisfeld Ralph A. , Niethammer Dietrich , Treuner Jörn 
Published: May 2005

AbstractWe investigated whether polymorphonuclear leukocytes (PMN) are able to kill human neuroblastoma cells either directly or if coated with antibody MAb 14.18 that recognizes ganglioside GD2 present on the cell surface of most neuroblastoma cells. Neuroblastoma cells could not be destroyed directly, whereas in the antibody‐dependent reaction (ADCC‐reaction) they were easily eliminated. In order to answer the question whether reactive oxygen intermediates are involved in this process, chemiluminescence measurements were performed. Compared to the signals that could be measured using opsonized zymosan as stimulus, only weak CL‐signals could be registered during the ADCC reaction. Pretreatment of PMN with granulocyte‐macrophage colony stimulating factor (GM‐CSF) enhanced the CL‐signals, catalase and SOD reduced it; however, cell killing was only slightly influenced in the presence of catalase and superoxide dismutase. These data suggested that reactive oxygen compounds do not play a prominent role in the killing process. Definitive evidence for this suggestion could be obtained using PMN from a patient with chronic granulomatous disease (CGD): MAb 14.18 coated neuroblastoma cells could be killed effectively, but no CL‐signal could be registered, either in the ADCC‐reaction or using opsonized zymosan as stimulus.
Free fatty acid determination by peroxidase catalysed luminol chemiluminescence
Authors: Näslund Birgitta M. A. , Bernström Kerstin , Lundin Arne , Arner Peter 
Published: May 2005

AbstractA sensitive, specific, and partly automatic method for the analysis of free fatty acids is described. The assay involves activation of free fatty acids by acyl‐CoA synthetase (EC 6.2.1.3) followed by oxidation of the thioesters by acyl‐CoA oxidase. The H2O2 formed is determined in a reaction catalysed by horseradish peroxidase (EC 1.11.1.7) using luminol as electron donor. The assay has a linear range of 0.05 to 5 nmol of different free fatty acids (C10‐C18) in the original sample. The efficiency of the method toward capric, lauric, myristic, palmitic, palmitoleic, stearic, oleic, and linoleic acid measured as recovery of light emission compared to that of H2O2 standards, was over 90%. AffiGel 501 was used to covalently bind the free thiol group in CoASH eliminating interference of this substance in the peroxidase‐luminol reaction.
Determination of absolute chemiluminescence quantum yields for reactions of bis‐(pentachlorophenyl) oxalate, hydrogen peroxide and fluorescent compounds
Authors: Catherall Colin L. R. , Palmer T. Frank , Cundall Robert B. 
Published: May 2005

AbstractAbsolute chemiluminescence quantum yields (ϕCL) for reactions of bis‐(pentachlorophenyl) oxalate (PCPO), hydrogen peroxide (H2O2) and 9:10 diphenyl anthracene (DPA) have been determined. A fully corrected chemiluminescence monitoring spectrometer was calibrated for spectral sensitivity using the chemiluminescence of the bis‐(pentachlorophenyl) oxalate system as a liquid light source, the total photon output of which had previously been determined by chemical actinometry. At high (PCPO)/(H2O2) ratios ϕCL was found to be independent of PCPO and H2O2 concentrations.
The ATP‐bioluminescence method for a rapid evaluation of the microbial activity in the stone materials of monuments
Authors: Tiano Piero , Tomaselli Luisa , Orlando Claudio 
Published: May 2005

AbstractThe examination of the state of conservation of works of art in stone includes the assessment of the presence of microbiological agents on the surface of the decayed monuments. These microorganisms can accelerate, via their metabolic activity, the decay process of the stone surface. At present this assessment is made with the traditional techniques for the microbiological examination of the soil, provides results only after a delay of 30 days. A bioluminescent ATP assay should provide rapid quantitation of actively growing organisms on the surface of a stone monument, and the applicability of this technique was verified on some samples of sandstone (Pietraforte) collected from a historic building (the Strozzi Palace) in Florence. These samples were evaluated for the amount of the ATP and the total number of microorganisms.The results obtained suggest that the bioluminescent assay could be suitable for detecting and quantitating the presence of microorganisms in a sample of stone.
Preliminary evaluation of urinary estrone‐3‐glucuronide (E1‐3G)LIA measurement for monitoring induction of ovulation in an in vitro fertilization programme (FIVET)
Authors: Rapi S. , Pellegrini S. , Massi G. B. 
Published: May 2005

AbstractThis study compares urinary E1‐3G and serum E2 measurements in monitoring ovulation induction in an in vitro fertilization programme (FIVET).We used an RIA kit, ESTR.CTK2 (Sorin, Italy), for the daily determination of serum E2, and an LA kit, Fertilux (Bouty, Milan), for the determination of E1‐3G in early morning urine samples using a timed and measured volume urine collection procedure.A significant correlation was found between serum E2 as measured by RIA and urinary E1‐3G as measured by LIA.Considering the RIA disadvantages (the short half‐life of the reagents, the hazards of handling radioactive materials, the inconvenience of frequent venepuncture for the patients) the LIA measurement seems to be a useful method in a FIVET programme.
Site‐directed mutagenesis of bacterial luciferase: Analysis of the ‘essential’ thiol
Authors: Baldwin T. O. , Chen L. H. , Chlumsky L. J. , Devine J. H. , Ziegler M. M. 
Published: May 2005

AbstractIt has been appreciated for many years that the luciferase from the luminous marine bacterium Vibrio harveyi has a highly reactive cysteinyl residue which is protected from alkylation by binding of flavin. Alkylation of the reactive thiol, which resides in a hydrophobic pocket, leads to inactivation of the enzyme. To determine conclusively whether the reactive thiol is required for the catalytic mechanism, we have constructed a mutant by oligonucleotide directed site‐specific mutagenesis in which the reactive cysteinyl residue, which resides at position 106 of the α subunit, has been replaced with a seryl residue. The resulting α106Ser luciferase retains full activity in the bioluminescence reaction, although the mutant enzyme has a ca 100‐fold increase in the FMNH2 dissociation constant. The α106Ser luciferase is still inactivated by N‐ethylmaleimide, albeit at about 1/10 the rate of the wild‐type (α106Cys) enzyme, demonstrating the existence of a second, less reactive, cysteinyl residue that was obscured in the wild‐type enzyme by the highly reactive cysteinyl residue at position α106. An α106Ala variant luciferase was also active, but the α106Val mutant enzyme was about 50‐fold less active than the wild type. All three variants (Ser, Ala and Val) appeared to have somewhat reduced affinities for the aldehyde substrate, the valine mutant being the most affected.It is interesting to note that the α106 mutant luciferases are much less subject to aldehyde substrate inhibition than is the wild‐type V. harveyi luciferase, suggesting that the molecular mechanism of aldehyde substrate inhibition involves the Cys at α106.
Chemiluminescent assay of various enzyme activites and its application to enzyme immunoassays
Authors: Maeda Masako , Arakawa Hidetoshi , Tsuji Akio 
Published: May 2005

AbstractA highly sensitive chemiluminescent assay for NAD(P)H have been developed. The principle of the method is as follows; NAD(P)H reduces molecular oxygen to superoxide anion (O) and hydrogen peroxide (H2O2) in the presence of 1‐methoxy‐5‐methylphenazinium methyl sulphate (1‐MPMS) as electron mediator. The produced O and H2O2 can be measured by chemiluminescent reaction using isoluminol (IL) and microperoxidase (m‐POD). A linear relationship between chemiluminescence intensity and NAD(P)H concentration (log/log) was obtained ranged from 10−9 mol/I to 10−5 mol/I. This chemiluminescent reaction has been coupled to the assay of glucose‐6‐phosphate dehydrogenase (G6PDH), β‐D‐galactosidase (β‐Gal) and alkaline phosphatase (ALP). The detection limits of G6PDH, β‐Gal and ALP were 10−18 mol, 10−20 mol and 10−18 mol per assay, respectively. The chemiluminescent assay of these enzymes applied to chemiluminescent enzyme immunoassay for 17α‐hydroxy‐progesterone and DNA hybridization assay using these enzymes as label.
Enhanced chemiluminescence ELISA for the detection of antibody to hepatitis B virus surface antigen
Authors: Ireland Deborah , Samuel Dhanraj 
Published: May 2005

AbstractA chemiluminescent enzyme linked immunosorbent assay (ELISA) for the detection of antibody to hepatitis B virus surface antigen (anti‐HBs) in human serum has been developed. Polystyrene microtitre plates were coated with recombinant, yeast‐derived hepatitis B surface antigen (rec‐HBsAg). Patient serum samples and appropriate controls were added to the rec‐HBsAg‐coated wells and incubated to bind anti‐HBs. The wells were then washed and a fluorescein isothiocyanate (FITC) conjugate of a human plasma‐derived hepatitis B surface antigen (HBsAg) was added. Following incubation and further washing the bound FITC‐labelled HBsAg was detected after addition of a horseradish peroxidase (HRP) conjugate of a monoclonal anti‐FITC antibody and assaying for the enzyme. The activity of the HRP was measured using luminol and hydrogen peroxide as substrates and iodophenol as a chemiluminescence enhancer. The luminescence was recorded using a camera luminometer.Preliminary tests have shown the assay to be suitable for the detection of antibody in sera from both vaccinees and also from individuals with a past hepatitis B virus infection. The use of the FITC‐anti‐FITC system together with the measurement of a chemiluminescence signal makes possible the completion of this assay in a few hours. The assay has been shown to be both specific and sensitive and provides a permanent photographic record.
Opsonophagocytosis of bacteria studied by chemiluminescence in microtitre plates
Authors: Hastings J. G. M. , Jewes L. A. , Oxley K. M. 
Published: May 2005

AbstractA protocol for polymorphonuclear leukocyte chemiluminescence (PMN CL) assays of opsonophagocytosis was developed for a microtitre‐plate luminometer. The complete procedure was performed in a single microtitre plate and was simpler and more efficient than previous protocols. The kinetics of the PMN CL response were best when microtitre plates were incubated on a shaking incubator between readings. The new protocol was used in a study of the pathogenicity of Corynebacterium jeikeium, an organism found in association with infection in the immunocompromised. No differences were found when PMN CL induction by 15 strains of C. jeikeium were compared with 15 isolates of other corynebacteria. Both groups of organisms required complement for efficient opsonophagocytosis; C. jeikeium strains showed no requirement for specific antibody. Resistance to opsonophagocytosis does not appear to be an explanation for the increased pathogenicity of C. jeikeium. Microtitre‐plate luminometers are particularly well suited to bacterial opsonization studies where large numbers of strains often need to be assessed.
Phagocytosis induction of chemiluminescence and chemoattractant increased superoxide anion release from activated human alveolar macrophages in asthma
Authors: Damon M. , Cluzel M. , Chanez P. , Godard Ph. 
Published: May 2005

AbstractHuman alveolar macrophages (AM) were demonstrated to generate reactive toxic derivatives of oxygen in many pulmonary disorders. These cells are involved in local inflammation which characterizes bronchial asthma. In the present work, we studied the ability of stimulated macrophages from healthy volunteers, and asthmatic patients to generate oxygen species in vitro. AM obtained by bronchoalveolar lavage were purified by adherence. The production of oxygen species was measured by luminol‐enhanced chemiluminescence (CL) after challenge with opsonized zymosan. The maximal values were significantly (p < 0.03 and p < 0.01) higher in AM from asthmatics than in AM from healthy subjects. A significant correlation (p < 0.01) was observed between maximal value of CL and the severity of asthma as assessed by the clinical score. But, no difference was observed between AM from asthmatics in a stable state and healthy subjects. On the other hand, assays for superoxide anion generation emphasized the activation state of these macrophages stimulated by formyl‐peptides.
Construction of a fused luxAB gene by site‐directed mutagenesis
Authors: Boylan M. O. , Pelletier J. , Dhepagnon S. , Trudel S. , Sonenberg N. , Meighen E. A. 
Published: May 2005

AbstractBacterial luciferases are heteropolymetric enzymes consisting of two non‐identical subunits (alpha and beta). The two polypeptides are produced by transcription in the same direction of two genes, luxA and luxB, located immediately adjacent to each other and separated by only 29 base pairs in the Vibrio harveyi genome. Using site‐directed mutagenesis, stop codons after luxA were eliminated and the luxB gene was placed in‐frame with luxA, resulting in a fused luxAB gene. Transcription of two luxAB mutant genes from the bacteriophage T7 promoter and translation in Escherichia coli resulted in the synthesis of fused polypeptides containing the alpha and the beta subunits of luciferase linked by either a single amino acid residue or a decapeptide. E. coli synthesizing the latter fusion protein with the decapeptide linker expressed a level of luminescence comparable to E. coli containing the wild type genes while E. coli synthesizing the polypeptide with a single amino acid as a linker expressed about 2000‐fold lower light. These results provide the basis for generating a bacterial luciferase system that can be expressed under the control of a single promoter in both eukaryotic and prokaryotic systems.
Luminescence in the study of lipid metabolism
Authors: Wieland E. , Niedmann D. , Diedrich F. , Seidel D. , Kather H. 
Published: May 2005

AbstractUsing bioluminescence assays for glycerol, free fatty acids, β‐hydroxybutyrate and lactate, we were able to perform complex studies of human energy and lipid metabolism both in serum samples in vivo and in isolated fat cells in vitro. These studies would have been impossible without reliable, specific and highly sensitive luminescence methods. Oxidatively modified low density lipoprotein (LDL) has been implicated in the pathogenesis of atherosclerosis. Adaptation of a chemiluminescence assay for lipid hydroperoxides to LDL isolated by specific precipitation from serum makes it possible to measure LDL oxidation in vivo. Cell dependent chemiluminescence was used to investigate whether receptor mediated endocytosis of LDL by macrophages leads to oxygen radical production in these cells. No activation of the membrane NAD(P)H oxidase was observed.
Principles and applications of luminescence spectrometry coupled to liquid chromatographic techniques
Authors: Baeyens Willy R. G. , Ling Betty Lin , Brinkman Udo A. Th. , Schulman Stephen G. 
Published: May 2005

AbstractAn overview is presented of the physicochemical basis of luminescence, and its application to the detection of chemicals (drugs, biomedically important compounds, environmentally active substances) in liquid chromatographic systems.
Luminescence biosensors
Authors: Aizawa M. , Tanaka M. , Ikariyama Y. , Shinohara H. 
Published: May 2005

AbstractA novel optical biosensor for homogeneous immunoassay has been developed on the basis of the finding that electrochemical luminescence of pyrene‐labelled antigen is extremely inhibited by immunochemical complexation. Electrochemical luminescence homogeneous immunoassay for human serum albumin (HSA), as a model analyte, was performed with a platinum plate electrode which was located in the vicinity of an optical fibre tip. HSA was determined in the concentration range of 3–25 × 10−6 mol/I.To improve electrochemical luminescence measurement an optical fibre electrode has been developed by fabricating a transparent platinum film on the top of an optical fibre. The minimum detectable limit of luminol was 10−11 mol/l with the optical fibre electrode. Luminol was applied as a label for homogeneous immunoassay.
A chemiluminescent method for the measurement of pregnanetriol‐3α‐glucuronide in human diluted urine
Authors: Pinzani P. , Magini A. , Franceschetti F. , Messeri G. , Pazzagli M. 
Published: May 2005

AbstractPregnanetriol‐3α‐glucuronide (PTG) is the majority urinary metabolite of 17‐hydroxyprogesterone (17OHP) and it typically increases in the commonest form of congenital adrenal hyperplasia (CAH), due to 21 hydroxylase deficiency.We developed a simple chemiluminescent immunoassay for the direct measurement of PTG in diluted urine in order to avoid the preliminary hydrolysis and extraction steps that are usually employed in gas–liquid chromatographic methods. The immunogenic complex PTG‐bovine‐serum‐albumin was used to induce the formation of specific antibodies in New Zealand rabbits. In addition, PTG was conjugated to aminoethylethylisoluminol and the resulting tracer was characterized by mass spectrometry and used to monitor the immunological reaction. The characteristics of the antibody were determined with regard to specificity and sensitivity. The precision of the assay method was also established.PTG excretion was studied before and after the ACTH stimulation test (1 mg synthetic ACTH i.m.) in 11 normal women and in one subject affected by CAH due to 21‐hydroxylase deficiency. PTG levels well correlated with 17OHP plasma concentrations both under basal and stimulated conditions, in normal women as well as in the patient affected by CAH.