bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thiols enhance the sensitivity of luminescent assays for non‐cross‐linked and covalently cross‐linked aminophthalhydrazides
Authors: Achyuthan Komandoor E. 
Published: January 2005

AbstractTransglutaminases catalyse an acyl‐transfer reaction between the γ‐carboxamide of a protein or peptide‐bound glutamine (P‐CH2‐γCH2‐CO‐1NH2) and the primary amino group of mono‐ or polyamines (R‐2NH2), covalently cross‐linking the reactants by an isopeptide bond: P‐CH2‐γCH2‐CO‐1NH2 + R‐2NH2 → P‐CH2‐γCH2‐CO‐2NH‐R + 1NH3. We reported that N‐(4‐aminobutyl)‐N‐ethylisoluminol (ABEI) was a chemiluminescent (CL) amine substrate for transglutaminases. We now identified N‐(6‐aminohexyl)‐N‐ethylisoluminol (AHEI) as a second, less reactive, transglutaminase substrate. A structure‐based explanation is offered for the lower reactivity of AHEI. Optimum CL from non‐cross‐linked or cross‐linked ABEI or AHEI was elicited in the presence of 10 mmol/L dithiothreitol, by oxidizing with a mixture of 20 mmol/L potassium ferricyanide and 10 mmol/L hydrogen peroxide in 100 mmol/L NaOH. The limits of detection and quantitation for non‐cross‐linked aminophthalhydrazides obtained in this system were: 20 fmol and 60 fmol for ABEI and 10 fmol and 30 fmol for AHEI. These values represented a 500–800‐fold improved sensitivity. Delayed peak CL and CL decay in the presence of dithiothreitol contributed to improving the sensitivity. The data could be useful for improving the immunoassays for aminophthalhydrazides and facilitate the development of high throughput assays for transglutaminases. Copyright © 2001 John Wiley & Sons, Ltd.
Analysis of single‐cell cultures by immunoaffinity capillary electrophoresis with laser‐induced fluorescence detection
Authors: Phillips Terry M. 
Published: January 2005

AbstractNeuropeptide regulation of immunological activity is becoming an important issue in both basic and clinical sciences, necessitating the need for analysis to be performed at the single‐cell level. A microsampling procedure has been developed for studying secretion of biologically important peptides from neuropeptide‐stimulated lymphocytes, based on microdialysis sampling coupled to immunoaffinity capillary electrophoresis (ICE), with laser‐induced fluorescence (LIF) detection using a fibre‐optic spectrometer and diode laser excitation. The system demonstrated a limit of detection in the high attomole (10−18 mol/L) range with pure standards and was capable of monitoring secretion from a single cell over time. Using this system it was possible to differentiate the effects of four neuropeptides on both T and B cell release of regulatory cytokines. CD4+ lymphocytes demonstrated a 7.5‐fold increase in cytokine secretion over baseline following stimulation with substance P (SP) and calcitonin gene‐related peptide (CGRP). B cells responded to CGRP and vasoactive intestinal peptide (VIP) stimulation (5.5‐fold increase), but not to SP. These changes took place 12–20 h post‐stimulation and, once the peak secretion had been reached, remained at that level for the duration of the experiment. This system demonstrates the ability to perform high sensitivity measurements on microsamples of biological fluids. Copyright © 2001 John Wiley & Sons, Ltd.
Applications of biochemiluminescence to HACCP
Authors: Champiat Dominique , Matas Nada , Monfort Bertrand , Fraass Hervé 
Published: January 2005

AbstractThe hazard analysis critical control point) (HACCP) system is set up with the aim of ensuring the harmlessness of food along the process chain, from the producer to the ultimate consumer. To set up this system, it is necessary to perform an analysis to identify the dangers and the critical points of the process in real time. Living organisms are detected on the principle of measurement of cellular energy in the form of adenosine triphosphate (ATP), which is produced by all living cells and of particularly by microorganisms. The principle of the bioluminescence of firefly luciferase is applied, whereby a reduced form of luciferin, together with a molecule of oxygen and ATP in the presence of the enzyme luciferase, produces a reaction in which oxyluciferine is released, together with AMP. This is accompanied by a simultaneous release of photons, which are then quantified. The emission spectra recorded with the firefly luciferin/luciferase system is obtained with absolute sensitivity. The method of ATP assays here proposed is adapted for measuring the total content of different adenylates in the cell, i.e. the adenylate pool. ATP concentration is then measured through bioluminescence, i.e. the light is measured by a photomultiplier tube detector and the signal is converted to relative light units (RLU). Thus, RLU have a relationship with the amount of ATP present in the sample, which is not the case with traditional methods. Adequate levels of sensitivity are calculated with appropriate controls and the readings are translated into a statistical designation of positive or negative result. There are numerous illustrations of HACCP applications using biochemiluminescence (BCL) techniques as detection technology in food industry production lines and in control of critical points in real time in industrial applications. Copyright © 2001 John Wiley & Sons, Ltd.
Development of ultra‐high sensitivity bioluminescent enzyme immunoassay for prostate‐specific antigen (PSA) using firefly luciferase
Authors: Seto Yoshiaki , Iba Toshihiko , Abe Katsushi 
Published: January 2005

AbstractA bioluminescent enzyme immunoassay (BLEIA) for prostate‐specific antigen (PSA) using biotinylated firefly luciferase‐labelled antibody was developed. PSA is an important marker for the diagnosis and management of prostate cancer. Our BLEIA for PSA, based on the two‐step sandwich method, had ultra‐high sensitivity and a very wide measurable range. The detection limit (mean of nine replicates of the zero standard +2 SD) for PSA was 0.25 pg/mL and the measurable range for PSA was 0.25 pg/mL–100 ng/mL. Generally, PSA in the serum exists on two forms, called free PSA (f‐PSA) and complex PSA (c‐PSA), which is formed with α‐antichymotripsin. Thus, the response of the PSA assay to these two forms has to be equimolar in the construction of the assay system. Our BLEIA for PSA also had an equimolar response to them. Copyright © 2001 John Wiley & Sons, Ltd.
Potential of NIR‐FT‐Raman spectroscopy in natural carotenoid analysis
Authors: Schulz H. , Baranska M. , Baranski R. 
Published: January 2005

AbstractThis paper demonstrates the special advantages of FT‐Raman spectroscopy for in situ studies of several carotenoids that occur ubiquitously in the plant kingdom. Spectra obtained from various tissues of a range of plant species indicate that the wavenumber location of CC stretching vibrations is mainly influenced both by the length as well as by the terminal substituents of the polyene chain of carotenoids and by their interaction with other plant constituents. The obtained results show also the usefulness of Raman spectroscopy in the investigation of cis–trans isomerization of carotenoids during processing. Additionally, 2‐D Raman mappings present a unique possibility to evaluate the individual distribution of carotenoids in the intact plant tissue; in this context different 7‐, 8‐, and 9‐double bond conjugated carotenoids can be analyzed independently in the same sample. Furthermore, the use of Raman spectroscopy for in situ detection of unstable substances such as epoxycarotenoids is discussed. © 2005 Wiley Periodicals, Inc. Biopolymers, 2005
Solid‐state NMR studies of collagen‐based parchments and gelatin
Authors: Aliev Abil E. 
Published: January 2005

AbstractHistorical collagen‐based parchments have been studied by solid‐state NMR. In addition, new parchment (produced according to traditional methods) and gelatin from bovine skin were also studied. Wideline 1H and MAS 13C measurements were carried out directly on intact parchments. A simple approach is proposed for evaluation of the extent of parchment degradation based on the linewidth changes in the 13C CPMAS spectra relative to new parchment and gelatin. Structural (bound) water content was estimated from wideline 1H NMR lineshape and relaxation time measurements. It was found that the relative water content in parchments correlates linearly with 13C MAS linewidths. Its decrease on parchment degradation indicates that structural water molecules are of primary importance in stabilizing higher order collagen structures. Backbone and side chain dynamics of collagen in parchments were compared to those of gelatin based on the 13C dipolar‐dephased experiments. Carbonyl 13C chemical shift anisotropies were measured to deduce the geometry of the collagen backbone motion. Unlike previous studies, we found that the collagen backbone motion is similar to that found in other proteins and occurs primarily via small‐angle librations about internal bond directions. © 2005 Wiley Periodicals, Inc. Biopolymers, 2005
Production of high‐purity isomalto‐oligosaccharides syrup by the enzymatic conversion of transglucosidase and fermentation of yeast cells
Authors: Pan Yen‐Chung , Lee Wen‐Chien 
Published: January 2005

AbstractA method for the production of high‐purity isomalto‐oligosaccharides (IMO) involving the transglucosylation by transglucosidase and yeast fermentation was proposed. The starch of rice crumbs was enzymatically liquefied and saccharified, and then converted to low‐purity IMO syrup by transglucosylation. The low‐purity IMO produced either from rice crumbs or tapioca flour as the starch source could be effectively converted to high‐purity IMO by yeast fermentation to remove the digestible sugars including glucose, maltose, and maltotriose. Both Saccharomyces carlsbergensis and Saccharomyces cerevisiae were able to ferment glucose in the IMO syrup. Cells of S. carlsbergensis harvested from the medium of malt juice were also able to ferment maltose and maltotriose. A combination of these two yeasts or S. carlsbergensis alone could be used to totally remove the digestible sugars in the IMO, coupled with the production of ethanol. The resultant high‐purity IMO, including mainly isomaltose, panose, and isomaltotriose made up more than 98% w/w of the total sugars after a 3‐day fermentation. When the low‐purity IMO was produced from the starch of tapioca flour, 3‐day fermentation under the same conditions resulted in IMO with purity lower than that from rice crumbs. For low‐purity IMO from rice crumbs, fermentation with washed S. carlsbergensis cells harvested at log phase was the most effective. However, for the low‐purity IMO from tapioca flour, incubation with S. cerevisiae for the first 24 h and then supplementing with an equal amount of S. carlsbergensis cells for further fermentation was the most effective approach for producing high‐purity IMO. © 2005 Wiley Periodicals, Inc.
Fluorogenic and fluorescent labeling reagents with a benzofurazan skeleton
Authors: Uchiyama Seiichi , Santa Tomofumi , Okiyama Natsuko , Fukushima Takeshi , Imai Kazuhiro 
Published: January 2005

AbstractFluorogenic and fluorescent labeling reagents having a benzofurazan (2,1,3‐benzoxadiazole) skeleton such as 4‐fluoro‐7‐nitro‐2,1,3‐benzoxadiazole (NBD‐F), 4‐N,N‐dimethylaminosulfonyl‐7‐fluoro‐2,1,3‐benzoxadiazole (DBD‐F), 4‐aminosulfonyl‐7‐fluoro‐2,1,3‐benzoxadiazole (ABD‐F), ammonium 7‐fluoro‐2,1,3‐benzoxadiazole‐4‐sulfonate (SBD‐F), 4‐hydrazino‐7‐nitro‐2,1,3‐benzoxadiazole (NBD‐H), 4‐N,N‐dimethylaminosulfonyl‐7‐hydrazino‐2,1,3‐benzoxadiazole (DBD‐H), 4‐nitro‐7‐N‐piperazino‐2,1,3‐benzoxadiazole (NBD‐PZ), 4‐N,N‐dimethylaminosulfonyl‐7‐N‐piperazino‐2,1,3‐benzoxadiazole (DBD‐PZ), 4‐(N‐chloroformylmethyl‐N‐methyl)amino‐7‐N,N‐dimethylaminosulfonyl‐2,1,3‐benzoxadiazole (DBD‐COCl) and 7‐N,N‐dimethylaminosulfonyl‐4‐(2,1,3‐benzoxadiazolyl) isothiocyanate (DBD‐NCS) are reviewed in terms of synthetic method, reactivity, fluorescence characteristics, sensitivity and application to analytes. Copyright © 2001 John Wiley & Sons, Ltd.
High‐performance liquid chromatographic assay for glucuronidation activity of 7‐ethyl‐10‐hydroxycamptothecin (SN‐38), the active metabolite of irinotecan (CPT‐11), in human liver microsomes
Authors: Hanioka Nobumitsu , Jinno Hideto , Nishimura Tetsuji , Ando Masanori , Ozawa Shogo , Sawada Jun‐ichi 
Published: January 2005

AbstractA simple and sensitive assay for glucuronidation activity of 7‐ethyl‐10‐hydroxycamptothecin (SN‐38), the active metabolite of irinotecan (CPT‐11), in human liver microsomes by high‐performance liquid chromatography (HPLC) with fluorescence detection is reported. The method was validated for the determination of SN‐38 glucuronide (SN‐38G) with respect to specificity, linearity, recovery, stability, precision, accuracy, and limits of detection and quantitation. There was no interference from matrix and non‐enzymatic reactions. The calibration curve for SN‐38G was linear from 5 to 500 nM. Average recoveries ranged from 98 to 100% in spiked human liver microsome samples, and the SN‐38G was stable at 4°C for at least 72 h. The newly developed method was found to be more sensitive and selective than previous methods using thin layer chromatography and HPLC. The limit of quantitation for SN‐38G was 5 nM (2.5 pmol/assay). The intra‐ and inter‐day precision and accuracy were less than 7 and 4%, respectively. The intra‐ and inter‐day precision of enzyme assay for UDP‐glucuronosyltransferase (UGT) activity toward SN‐38 in human liver microsomes was less than 4%. With this improved sensitivity, the kinetics of SN‐38 glucuronidation in human liver microsomes could be determined more precisely. Therefore, this method is applicable to in vitro study on the side effects and drug interactions of CPT‐11 using small amounts of biological sample. Copyright © 2001 John Wiley & Sons, Ltd.
Abbreviations used:

CPT‐11

7‐ethyl‐10‐[4‐(1‐piperidino)‐1‐piperidino]carbonyloxycamptothecine

SN‐38

7‐ethyl‐10‐hydroxycamptothecin

UGTs

UDP‐glucuronosyltransferases.
Detection of perfluorocarbons in blood by headspace solid‐phase microextraction combined with gas chromatography/mass spectrometry
Authors: Mathurin Jean‐Charles , Ceaurriz Jacques de , Audran Michel , Krafft Marie‐Pierre 
Published: January 2005

AbstractA new method of detection of perfluorocarbon molecules (PFCs) in blood sample has been established. After an extraction and pre‐concentration step performed by headspace solid‐phase microextraction (HS‐SPME), the PFCs are detected by gas chromatography‐mass spectrometry (GC/MS) with an ion trap mass spectrometer in MS and MS/MS modes. The influence of different parameters on the SPME process is discussed. The limit of detection and the linearity of the procedure have been determined for two PFCs. Copyright © 2001 John Wiley & Sons, Ltd.
Abbreviations used:

EI

electron impact

EPO

erythropoietin

FDC

F‐decaline

HS‐SPME

headspace solid‐phase extraction

IOC

International Olympic Committee

LOD

Limit of detection

PDMS

polydimethylsiloxane

PFCs

perfluorocarbon molecules
The relationship between criminal charges, diagnoses, and psycholegal opinions among federal pretrial defendants
Authors: Cochrane Robert E. , Grisso Thomas , Frederick Richard I. 
Published: January 2005

AbstractThis study analyzed data from 1710 criminal defendants referred by federal courts throughout the United States. We examined 12 categories of criminal charges with respect to diagnosed psychopathology and opinions related to competence to stand trial (CST) and criminal responsibility (CR) at the time of the alleged offense. Overall, 18% of the present sample were found to be incompetent to stand trial, while 12% were found to be not criminally responsible or ‘insane.’ In this study, crimes were associated with rates of psychopathology and rates of opinions regarding CST and CR. The findings of this study suggest that individuals who are charged with different crimes have different mental states and psychopathology and are therefore found to have differential rates of competence and sanity. Copyright © 2001 John Wiley & Sons, Ltd.
The “Invisible” 13C NMR Chemical Shift of the Central Carbon Atom in [(Ph3PAu)6C]2+: A Theoretical Investigation
Authors: Le Guennic Boris , Neugebauer Johannes , Reiher Markus , Autschbach Jochen 
Published: January 2005

AbstractThe experimental 13C NMR chemical shift of the central carbon atom in the octahedral [(Ph3PAu)6C]2+ cluster was investigated on the basis of relativistic density functional calculations. In order to arrive at independent model conclusions regarding the value of the chemical shift, a systematic study of the dependence of the cluster structure on the phosphine ligands, the chosen density functionals, and the basis set size was conducted. The best structures obtained were then used in the NMR calculations. Because of the cage‐like cluster structure a pronounced deshielding of the central carbon nucleus could have been expected. However, upon comparison with the 13C NMR properties of the related complex [C{Au[P(C6H5)2(p‐C6H4NMe2)]}6]2+, Schmidbaur et al. have assigned a signal at δ=135.2 ppm to the interstitial carbon atom. Our calculations confirm this value in the region of the aromatic carbon atoms of the triphenylphosphine ligands. The close‐lying signals of the 108 phenyl carbon atoms can explain the difficulties of assigning them experimentally.
Solid‐State Molecular Organization and Solution Behavior of Methane‐1,1‐Diphosphonic Acid Derivatives of Heterocyclic Amines: The Role of the Topochemical Ring Modification and the Intramolecular Hydrogen Bonds in Monosubstituted Piperid‐1‐ylmethane‐1,1‐diphosphonic Acids
Authors: Matczak‐Jon Ewa , Videnova‐Adrabińska Veneta , Burzyńska Agnieszka , Kafarski Paweł , Lis Tadeusz 
Published: January 2005

AbstractThe crystal structures of 3‐methylpiperid‐1‐ylmethane‐1,1‐diphosphonic (2), 4‐methylpiperid‐1‐ylmethane‐1,1‐diphosphonic (3), 2‐ethylpiperid‐1‐ylmethane‐1,1‐diphosphonic (4), and 2‐methylpiperid‐1‐ylmethane‐1,1‐diphosphonic (5) acids have been determined and are discussed with respect to their molecular organization and crystal‐packing preferences. The chair conformation, predominant also in solution, favors equatorial positioning of the bulky subsituents of the heterocyclic N and C atoms. The molecular geometry also provides access to intramolecular hydrogen‐bond formation between the axial protons located on the nitrogen atoms, as well as the carbon atoms closest to it, and phosphonic/phosphonate oxygen atoms. The molecules preferably arrange in monolayers, observed in all crystals with an exception of 3. The layers are held in place in the third direction through van der Waals interactions. The analysis of two‐dimensional hydrogen‐bonded networks is concentrated on revealing how the substituent's topology of the molecule affects the solid‐state organization in well‐defined structures and is aimed at unraveling the consequences and the possible conformational changes by stepwise network disruption upon crystal dissolution in water. The solution NMR studies are focused on revealing the role that the topochemistry of the substituent plays for the stereodynamics in 2–5. It is demonstrated that in constrast to piperid‐1‐ylmethane‐1,1‐diphosphonic acid (1), in which the ring inversion/rotation around the CN bond concerted with the NH⋅⋅⋅O hydrogen‐bond breaking/formation process leads to a mixture of two interconverting conformers, the concerted NH⋅⋅⋅O breaking/rotation/NH⋅⋅⋅O formation process in 2 and 3 allows for a predominance of one conformer in solution. However, placement of a substituent at 2‐position in the ring hampers the rotation around the CN bond; this makes 4 and 5 significantly less flexible relative to compounds 1–3. In addition, both compounds 4 and 5 are proved to exist as a mixture of two conformers, the equilibrium of which in acidic solution is shifted towards the conformer found in solid state. In alkaline solutions of 4 and 5, the equilibrium is shifted towards the conformer that is forced by the flipping of the heterocyclic ring. These results correlate well with recently documented differences in the biological potency of this group of compounds.
Anion Control over Interpenetration and Framework Topology in Coordination Networks Based on Homoleptic Six‐Connected Scandium Nodes
Authors: Long De‐Liang , Hill Robert J. , Blake Alexander J. , Champness Neil R. , Hubberstey Peter , Wilson Claire , Schröder Martin 
Published: January 2005

AbstractReaction of ScX3 (X=NO3−, CF3SO3−, ClO4−) with 4,4′‐bipyridine‐N,N′‐dioxide (L) affords topologically distinct six‐connected three‐dimensional coordination frameworks, {[Sc(L)3](NO3)3}∞ (1), {[Sc(L)3](CF3SO3)3(CH3OH)2.7(H2O)3}∞ (2), {[Sc(L)3](ClO4)3}∞ (3) and {[Sc(L)4(H2O)2](ClO4)3}∞ (4). Compounds 1, 2 and 3 are networks based on octahedrally co‐ordinated ScO6 centres bound through six oxygen atoms from six separate N‐oxide ligands L. Compounds 1 and 3 are doubly interpenetrated and have α‐polonium‐type structures of 41263 topology based upon three intersecting (4,4) nets. The structure of 2 is unusual and shows parallel, co‐planar layers of (4,4) nets connected in a criss‐crossed fashion to afford a new 48668 topology. In 4 only four ligands L bind to each ScIII centre with two additional water molecules bridging metal nodes. Significantly, the bridges formed by L do not sit in a plane and if connections through L are considered alone the resultant structure is a diamondoid array typically based upon a tetrahedral connecting node at Sc. Five interpenetrating diamondoid networks are observed that are cross‐bridged by water molecules to form a single three‐dimensional array of 4867 topology. Compound 4 can also be viewed as incorporating two intersecting (4,4) grids based upon two ligands L and two bridging waters. Thus, variation of anion, solvent and conditions critically affects the structures of products formed, and the series of polymers reported herein illustrates how tectons based upon (4,4) grids can be combined and distorted to form non‐NaCl topologies and even cross‐bridged, multiply interpenetrated diamondoid materials. Both compounds 2 and 4 represent unusual examples of self‐penetrated coordination frameworks.
Synthesis of Two Linear PADRE Conjugates Bearing a Deca‐ or Pentadecasaccharide B Epitope as Potential Synthetic Vaccines against Shigella flexneri Serotype 2a Infection
Authors: Bélot Frédéric , Guerreiro Catherine , Baleux Françoise , Mulard Laurence A. 
Published: January 2005

AbstractThe blockwise synthesis of the 2‐aminoethyl glycosides of a deca‐ and a pentadecasaccharide made of two and three repeating units, respectively, of the Shigella flexneri serotype 2a specific polysaccharide is reported. The strategy relies on trifluoromethanesulfonic acid mediated glycosylation of a pentasaccharide building block acting as a glycosyl donor and a potential glycoside acceptor. Both targets were made available in amounts large enough for their subsequent conversion into glycoconjugates. Indeed, efficient elongation of the spacer through an acetylthioacetyl moiety and subsequent conjugation onto a Pan HLA DR‐binding epitope (PADRE) T‐cell‐universal peptide resulted in two fully synthetic neoglycopeptides, which will be evaluated as potential vaccines against S. flexneri serotype 2a infections.