bluuebunny/crossref_metadata_2025_split huggingface dataset:
Local production of complement proteins in rheumatoid arthritis synovium
Authors: Neumann Elena , Barnum Scott R. , Tarner Ingo H. , Echols Josh , Fleck Martin , Judex Martin , Kullmann Frank , Mountz John D. , Schölmerich Jürgen , Gay Steffen , Müller‐Ladner Ulf 
Published: August 2002

AbstractObjectiveComplement has been repeatedly implicated in the pathogenesis of rheumatoid arthritis (RA) based on studies showing reduced levels of native complement components and increased levels of complement metabolites in plasma, synovial fluid (SF), and synovial tissue (ST) of RA patients. However, there is limited information on local production and activation of key factors of the complement cascade in RA synovium and their potential modulation by novel anticytokine therapies. This study was undertaken to characterize the expression of complement proteins and receptors in RA SF and ST.MethodsUsing in situ hybridization, immunohistochemistry, and Western blot techniques, we assessed the presence of complement proteins C3, factor B (FB), and C5b–9, as well as the expression of complement receptors C3aR and C5aR in rheumatoid synovium. C3 and FB levels in SF were determined by enzyme‐linked immunosorbent assay. Functional assessment was performed by examining the effects of soluble tumor necrosis factor receptor (sTNFR) p55 gene transfer in the SCID mouse model of RA.ResultsComplement proteins and receptors could be localized in all RA synovial specimens, whereas in osteoarthritis (OA) synovium, only a few, single cells expressed complement proteins and receptors. No differences were noted in the concentration of C3 between RA and OA in SF; however, FB levels were markedly reduced in RA versus OA SF. In RA synovium, in contrast to OA synovium, local expression of complement factor and complement receptor messenger RNA was found throughout the various ST compartments, suggesting that activation of the complement cascade occurs in all parts of the rheumatoid synovium. Moreover, C5aR expression was up‐regulated following overexpression of sTNFR p55 by adenovirus‐based gene transfer.ConclusionIn summary, local complement production and activation may play an important role in RA, and specific modulation and inhibition of local complement production could be an attractive therapeutic target for RA.
Web searching: A process‐oriented experimental study of three interactive search paradigms
Authors: Dennis Simon , Bruza Peter , McArthur Robert 
Published: August 2002

AbstractThis article compares search effectiveness when using query‐based Internet search (via the Google search engine), directory‐based search (via Yahoo), and phrase‐based query reformulation‐assisted search (via the Hyperindex browser) by means of a controlled, user‐based experimental study. The focus was to evaluate aspects of the search process. Cognitive load was measured using a secondary digit‐monitoring task to quantify the effort of the user in various search states; independent relevance judgements were employed to gauge the quality of the documents accessed during the search process and time was monitored as a function of search state. Results indicated directory‐based search does not offer increased relevance over the query‐based search (with or without query formulation assistance), and also takes longer. Query reformulation does significantly improve the relevance of the documents through which the user must trawl, particularly when the formulation of query terms is more difficult. However, the improvement in document relevance comes at the cost of increased search time, although this difference is quite small when the search is self‐terminated. In addition, the advantage of the query reformulation seems to occur as a consequence of providing more discriminating terms rather than by increasing the length of queries.
A database selection expert system based on reference librarian's database selection strategy: A usability and empirical evaluation
Authors: Ma Wei 
Published: August 2002

AbstractThe proliferation of digital information resources and electronic databases challenges libraries and demands that libraries develop new mechanisms to facilitate and better inform user selection of electronic databases and search tools. We developed a prototype, Web‐based database selection expert system based on reference librarian's database selection strategy. This system allows users to simultaneously search all databases available to identify databases most relevant to their quests using free‐text keywords or phrases taken directly from their research topics. This article reports on (1) the initial usability test and evaluation of the Selector—the test design, methodology used, performance results; (2) summary of search query analyses; (3) user satisfaction measures; (4) the use of the findings for further modification of the Selector; and (5) the findings of using randomly selected subjects to perform a usability test with predefined searching scenarios. Future prospects of this research have also been discussed in the article.
Factors confounding cytosolic calcium measurements in Jurkat E6.1 cells during exposure to ELF magnetic fields
Authors: McCreary Cheryl R. , Thomas Alex W. , Prato Frank S. 
Published: August 2002

AbstractReported changes in the cytosolic calcium concentration ([Ca2+]c) as a result of exposure to extremely low frequency (ELF) magnetic fields (MF) have been equivocal. In this study, we examine the possibility that some of these differences are attributable to variability associated with the cell cycle, pH of the suspension medium, and response to a calcium agonist. We used a custom designed spectrofluorimeter to measure [Ca2+]c in Indo 1‐AM loaded Jurkat E6.1 cells suspended in conditioned RPMI 1640 medium containing 10% fetal bovine serum. Four exposures were examined: zero static MF (Null), 60 Hz 100 μTpeak sinusoidal MF (AC), 78 μT static MF (DC), and the combination of the 60 Hz and the 78 μT static MF (AD + DC). A significant decrease in normalized [Ca2+]c values between 375–495 s for the DC and AC + DC groups was found in comparison to the Null group. However, statistical analysis indicated that cell cycle and quality of the α‐CD3 monoclonal antibody response were significant covariates, while pH was not a significant covariate. When the effect of these covariates was taken into account, all exposure groups were significantly different from the control. Our results suggest that ELF MF effects may not be seen unless correction is made for biological variability of each cell preparation with respect to cell cycle and [Ca2+]c response to antigen stimulation. Bioelectromagnetics 23:315–328, 2002. © 2002 Wiley‐Liss, Inc.
The determinants of Canadian children's personal exposures to magnetic fields
Authors: Armstrong Ben G. , Deadman Jan , McBride Mary L. 
Published: August 2002

AbstractStudy of the health effects of magnetic fields often depends on identifying determinants and hence indicators of personal exposure. This study identified determinants of children's exposure to magnetic fields and constructed a prediction model for them. For 632 children participating in a case–control study of childhood leukemia, we made direct measures of exposure over 48 h using a portable device, together with observations on candidate determinants. A child's age and sex, the proportion of time spent in the home, and their parents' education or income were very weak predictors of (logged) mean 48 h magnetic field (R2 < 1%). More important were province (R2 = 8.0%) and type of residence (R2 = 11.3%). Low temperatures at the time of measurement were associated with high fields (about 20% increase for each 10°C below 14, R2 = 4.9%). Several visible attributes of wiring around residences predicted exposure, mostly captured in the Wertheimer‐Leeper wire code (R2 = 13.5%). Stationary 24 h measurement in the bedroom (R2 = 63.3%) and spot measurements outside the house (R2 = 40.7%) predicted personal exposures best. Adding other minor predictors increased only slightly variance explained by 24 h stationary (R2 = 66.2%) and spot (R2 = 46.8%) measurements. Without spot or stationary measurements, the best model was much less powerful (R2 = 29.0%). We conclude that spot measurements outside the residence provide a moderately effective basis for estimating exposure for children living there, but do not perform as well as 24 h stationary measurements in the child's bedroom. Although several other easily‐observed variables were associated with personal exposure, they were weak determinants, either individually or in combination. Bioelectromagnetics 22:161–169, 2001. © 2001 Wiley‐Liss, Inc.
Exposure of Caenorhabditis elegans to extremely low frequency high magnetic fields induces stress responses
Authors: Miyakawa Tomokazu , Yamada Sotoshi , Harada Shin‐ichi , Ishimori Takayuki , Yamamoto Hiroshi , Hosono Ryuji 
Published: August 2002

AbstractResponses of the small heat shock protein gene, hsp‐16, were examined in transgenic Caenorhabditis elegans exposed to electromagnetic fields. Expression of the hsp‐16‐lacZ gene was enhanced when transgenic animals were exposed to magnetic fields up to 0.5 T at 60 Hz. The hsp‐16 promoter was more efficiently expressed at the embryonic than at the post‐embryonic stage irrespective of exposure. Promoter activity was more sensitive to the stimulus in the intestine at the post‐embryonic stage. Evidence is presented that the induction occurs at the transcriptional step of hsp‐16. Bioelectromagnetics 22:333–339, 2001. © 2001 Wiley‐Liss, Inc.
Hypocretin/orexin, sleep and narcolepsy
Authors: Hungs Marcel , Mignot Emmanuel 
Published: August 2002

AbstractThe discovery that hypocretins are involved in narcolepsy, a disorder associated with excessive daytime sleepiness, cataplexy and unusually rapid transitions to rapid‐eye‐movement sleep, opens a new field of investigation in the area of sleep control physiology. Hypocretin‐1 and ‐2 (also called orexin‐A and ‐B) are newly discovered neuropeptides processed from a common precursor, preprohypocretin. Hypocretin‐containing cells are located exclusively in the lateral hypothalamus, with widespread projections to the entire neuroaxis. Two known receptors, Hcrtr1 and Hcrtr2, have been reported. The functional significance of the hypocretin system is rapidly emerging in both animals and humans. Hypocretin abnormalities cause narcolepsy in dogs, human and mice. The role of the hypocretin system in normal sleep regulation is more uncertain. We believe hypocretin cells drive cholinergic and monoaminergic activity across the sleep cycle. Input from the suprachiasmatic nucleus to hypocretin‐containing neurons may explain the occurrence of clock‐dependent alertness. Other functions are suggested by pharmacological and neurochemical experiments. These include regulation of food intake, neuroendocrine function, autonomic nervous system activity and energy balance. BioEssays 23:397–408, 2001. © 2001 John Wiley & Sons, Inc.
Flow‐chemiluminescence: a growing modality of pharmaceutical analysis
Authors: Mestre Y. Fuster , Zamora L. Lahuerta , Calatayud J. Martínez 
Published: August 2002

AbstractThe present article deals with a review of the applications of the chemiluminescence to pharmaceutical analyses by using continuous‐flow assemblies. A comprehensive study on the fundamentals of the chemiluminescence is also included. Copyright © 2001 John Wiley & Sons, Ltd.
Detection of Texas red‐labelled double‐stranded DNA by non‐enzymatic peroxyoxalate chemiluminescence
Authors: Alba F. Javier , Daban Joan‐Ramon 
Published: August 2002

AbstractWe have found previously that different fluorescent dyes cannot be efficiently excited by the bis(2,4,6‐trichlorophenyl)oxalate (TCPO)–H2O2 reaction when they are intercalated between the DNA bases or bound to the minor groove of the double helix. Here we show that the fluorescent dye Texas red, covalently bound to the 3′ ends of double‐stranded DNA molecules, exhibits a high emission intensity when excited by the TCPO–H2O2 reaction. In this case, the charge transfer between the intermediate produced in the peroxyoxalate chemiluminescent reaction and Texas red can take place because this fluorophore is not buried inside the DNA structure. We describe the application of this chemiluminescent reaction to the detection of blotted DNA on nylon membranes. Copyright © 2001 John Wiley & Sons, Ltd.
Selective monitoring of 3 out of 50,000 protein vibrations
Authors: Barth Andreas 
Published: August 2002

AbstractAn important group in a large protein, which is the phosphate group that transiently binds to the Ca2+ transporting ATPase (Ca2+‐ATPase) of the sarcoplasmic reticulum membrane, is selectively observed with IR spectroscopy. The three phosphate stretching vibrations stand out from the 50,000 protein vibrations in an isotope exchange experiment where oxygen exchange at the phosphate group is catalyzed by the Ca2+‐ATPase. © 2002 Wiley Periodicals, Inc. Biopolymers (Biospectroscopy) 67: 237–241, 2002
H93G myoglobin cavity mutant as versatile template for modeling heme proteins: Magnetic circular dichroism studies of thiolate‐ and imidazole‐ligated complexes
Authors: Dawson John H. , Pond Alycen E. , Roach Mark P. 
Published: August 2002

AbstractRecent ligand binding and spectroscopic investigations of the myoglobin H93G cavity mutant are reviewed, revealing it to be a versatile template for the preparation of model heme complexes of defined structure. The H93G myoglobin cavity mutant is shown to be capable of forming mixed ligand adducts because of the difference in accessibility of the two sides of the ferric heme iron. With imidazole bound in the proximal cavity, H93G myoglobin also forms reasonably stable oxyferrous and oxoferryl derivatives, thereby providing a potential system to use for the study of such complexes with proximal ligands other than imidazole. In addition, thiolate‐ligated ferric H93G derivatives are described that serve as spectroscopic models for the high‐spin ferric state of cytochrome P450. All of the complexes described are characterized with magnetic circular dichroism spectroscopy, and they are compared to the appropriate derivatives of native myoglobin and P450. © 2002 Wiley Periodicals, Inc. Biopolymers (Biospectroscopy) 67: 200–206, 2002
Time‐resolved resonance Raman study on ultrafast structural relaxation and vibrational cooling of photodissociated carbonmonoxy myoglobin
Authors: Kitagawa Teizo , Haruta Nami , Mizutani Yasuhisa 
Published: August 2002

AbstractA localized small structural change is converted to a higher order conformational change of protein and extends to a mesoscopic scale to induce a physiological function. To understand such features of protein, ultrafast dynamics of myoglobin (Mb) following photolysis of carbon monoxide were investigated. Recent results are summarized here with a stress on structural and vibrational energy relaxation. The core expansion of heme takes place within 2 ps but the out of plane displacement of the heme iron and the accompanying protein conformational change occur in 10 and 100 s of the picosecond regimes, respectively. Unexpectedly, it was found from UV resonance Raman spectra that Trp7 in the N‐terminal region and Tyr151 in the C‐terminal region undergo appreciable structural changes upon ligand binding–dissociation while Tyr104, Tyr146, and Trp14 do not. Because of the communication between the movements of these surface residues and the heme iron, the rate of spectral change of the iron‐histidine (Fe‐ His) stretching band after CO photodissociation is influenced by the viscosity of solvent. Temporal changes of the anti‐Stokes Raman intensity demonstrated immediate generation of vibrationally excited heme upon photodissociation and its decay with a time constant of 1–2 ps. © 2002 Wiley Periodicals, Inc. Biopolymers (Biospectroscopy) 67: 207–213, 2002
Structural features and conformational equilibria of 310‐helical peptides in solution by spectroscopic and molecular mechanics studies
Authors: Pispisa B. , Mazzuca C. , Palleschi A. , Stella L. , Venanzi M. , Formaggio F. , Toniolo C. , Broxterman Q. B. 
Published: August 2002

AbstractThe structural features and conformational equilibria of a series of short, linear Cα‐methylvaline [(αMe)Val]‐based peptides in methanol were investigated by combining fluorescence resonance energy transfer measurements and molecular mechanics data. IR spectra were employed to determine their secondary structure, which exhibits an intramolecularly H‐bonded, 310‐helix conformation that is affected by backbone distortions that are enhanced by the shortness of the main chain. © 2002 Wiley Periodicals, Inc. Biopolymers (Biospectroscopy) 67: 247–250, 2000
Fluorescence spectroscopy study of protoporphyrin IX metabolism level in cells
Authors: Miah M. Idrish 
Published: August 2002

AbstractFluorescence spectroscopy was used to study the protoporphyrin IX (PpIX) metabolism level in chick embryos during the cell proliferation process. The emission spectra were measured for PpIX bound to albumin from nonincubated and incubated eggs. The relative characteristic emission intensity of PpIX was used to determine the level of PpIX metabolism as a function of the embryonic development time. This technique might be used to estimate tumor development time. © 2001 John Wiley & Sons, Inc. Biopolymers (Biospectroscopy) 62: 237–240, 2001
Time‐dependent solubilization of IgG in AOT‐brine‐isooctane microemulsions: Role of cluster formation
Authors: Gerhardt N. I. , Dungan S. R. 
Published: August 2002

AbstractThe stability and structure of protein‐containing water‐in‐oil (w/o) microemulsions were investigated by using the large protein immunoglobulin G (IgG, MW 155,000) in a mixture comprised of brine, sulfosuccinic acid bis [2‐ethylhexyl]ester (sodium salt), and isooctane. We explored factors affecting the initial uptake of IgG into the w/o microemulsion and its subsequent release to a solid (precipitate) phase, and the kinetics of the latter process. Influences of such parameters as pH, ionic strength, and protein concentration on the solubilization and precipitation of bovine IgG in the organic phase are described. The structure and dynamics in microemulsions containing bovine IgG were probed by using dynamic light scattering, and it was found that the presence of IgG in the microemulsion induced strong attractive forces between the droplets. Based on results obtained by using these various experimental approaches, a model for protein solubilization and release is proposed. In this model, we propose the formation of clusters within which bovine IgG resides and which substantially slow the kinetics of protein release from the droplets to the precipitate phase. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 78: 60–72, 2002; DOI 10.1002/bit.10183
High‐cell‐density fermentation for production of L‐N‐carbamoylase using an expression system based on the Escherichia coli rhaBAD promoter
Authors: Wilms Burkhard , Hauck Achim , Reuss Matthias , Syldatk Christoph , Mattes Ralf , Siemann Martin , Altenbuchner Josef 
Published: August 2002

AbstractA high‐cell‐density fed‐batch fermentation for the production of heterologous proteins in Escherichia coli was developed using the positively regulated Escherichia coli rhaBAD promoter. The expression system was improved by reducing of the amount of expensive L‐rhamnose necessary for induction of the rhamnose promoter and by increasing the vector stability. Consumption of the inducer L‐rhamnose was inhibited by inactivation of L‐rhamnulose kinase encoding gene rhaB of Escherichia coli W3110, responsible for the first irreversible step in rhamnose catabolism. Plasmid instability caused by multimerization of the expression vector in the recombination‐proficient W3110 was prevented by insertion of the multimer resolution site cer from the ColE1 plasmid into the vector. Fermentation experiments with the optimized system resulted in the production of 100 g L−1 cell dry weight and 3.8 g L−1 of recombinant L‐N‐carbamoylase, an enzyme, which is needed for the production of enantiomeric pure amino acids in a two‐step reaction from hydantoins. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 73: 95–103, 2001.
Transformation of 2,4,6‐trinitrotoluene (TNT) by immobilized Phanerochaete chrysosporium under fed‐batch and continuous TNT feeding conditions
Authors: Rho Denis , Hodgson Jonathan , Thiboutot Sonia , Ampleman Guy , Hawari Jalal 
Published: August 2002

AbstractThe cometabolic transformation of 2,4,6‐trinitrotoluene (TNT) by an immobilized Phanerochaete chrysosporium culture was investigated under different TNT and/or glycerol feeding conditions in a 5‐L reactor. In the fed‐batch feeding mode, as a result of four spiking events at an average feeding rate of 20 mg TNT L−1 d−1 and 250 mg glycerol L−1 d−1, the initial TNT transformation rate and the glycerol uptake rate of the 7‐day‐old immobilized cell culture were 2.41 mg L−1 h−1 and 16.6 mg L−1 h−1, respectively. Thereafter, the TNT fed into the reactor depicted a negative effect on the cell physiology of P. chrysosporium, i.e., both rates decreased constantly. At 32 mg TNT L−1 d−1 feeding rate, also in the presence of glycerol (200 mg L−1 d−1), this effect on the fungal cell metabolism was even more significant. When TNT was fed alone at 3.7 mg L−1 d−1, it showed an initial 0.75 mg L−1 h−1 rate of TNT transformation, i.e., one‐third the initial level observed in the presence of glycerol. In contrast, in the continuous feeding mode (dilution rate, D = 0.11 d−1), at 5.5 mg TNT L−1 d−1 and 220 mg glycerol L−1 d−1, the immobilized cell culture exhibited a constant TNT transformation rate for cultivation periods of 50 and 61 days, under uncontrolled and controlled pH conditions, respectively. Thereafter, during the latter experiment, 100% TNT biotransformation was achieved at 1,100 mg L−1 d−1 glycerol feeding rate. Immobilized cells (115‐day‐old), sampled from a continuous TNT feeding experiment, mineralized [14C]‐TNT to a level of 15.3% following a 41‐day incubation period in a microcosm. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 73: 271–281, 2001.
Residence time distributions of gas flowing through rotating drum bioreactors
Authors: Hardin Matthew T. , Howes Tony , Mitchell David A. 
Published: August 2002

AbstractResidence time distribution studies of gas through a rotating drum bioreactor for solid‐state fermentation were performed using carbon monoxide as a tracer gas. The exit concentration as a function of time differed considerably from profiles expected for plug flow, plug flow with axial dispersion, and continuous stirred tank reactor (CSTR) models. The data were then fitted by least‐squares analysis to mathematical models describing a central plug flow region surrounded by either one dead region (a three‐parameter model) or two dead regions (a five‐parameter model). Model parameters were the dispersion coefficient in the central plug flow region, the volumes of the dead regions, and the exchange rates between the different regions. The superficial velocity of the gas through the reactor has a large effect on parameter values. Increased superficial velocity tends to decrease dead region volumes, interregion transfer rates, and axial dispersion. The significant deviation from CSTR, plug flow, and plug flow with axial dispersion of the residence time distribution of gas within small‐scale reactors can lead to underestimation of the calculation of mass and heat transfer coefficients and hence has implications for reactor design and scale‐up. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 74: 145–153, 2001.