bluuebunny/crossref_metadata_2025_split huggingface dataset:
Elevated expression of Nkx‐2.5 in developing myocardial conduction cells
Authors: Thomas Penny S. , Kasahara Hideko , Edmonson Angela M. , Izumo Seigo , Yacoub Magdi H. , Barton Paul J.R. , Gourdie Robert G. 
Published: August 2002

AbstractA number of different phenotypes emerge from the mesoderm‐derived cardiomyogenic cells of the embryonic tubular heart, including those comprising the cardiac conduction system. The transcriptional regulation of this phenotypic divergence within the cardiomyogenic lineage remains poorly characterized. A relationship between expression of the transcription factor Nkx‐2.5 and patterning to form cardiogenic mesoderm subsequent to gastrulation is well established. Nkx‐2.5 mRNA continues to be expressed in myocardium beyond the looped, tubular heart stage. To investigate the role of Nkx‐2.5 in later development, we have determined the expression pattern of Nkx‐2.5 mRNA by in situ hybridization in embryonic chick, fetal mouse, and human hearts, and of Nkx‐2.5 protein by immunolocalization in the embryonic chick heart. As development progresses, significant nonuniformities emerge in Nkx‐2.5 expression levels. Relative to surrounding force‐generating (“working”) myocardium, elevated Nkx‐2.5 mRNA signal becomes apparent in the specialized cells of the conduction system. Similar differences are found in developing chick, human, and mouse fetal hearts, and nuclear‐localized Nkx‐2.5 protein is prominently expressed in differentiating chick conduction cells relative to adjacent working myocytes. This tissue‐restricted expression of Nkx‐2.5 is transient and correlates with the timing of spatio‐temporal recruitment of cells to the central and the peripheral conduction system. Our data represent the first report of a transcription factor showing a stage‐dependent restriction to different parts of the developing conduction system, and suggest some commonality in this development between birds and mammals. This dynamic pattern of expression is consistent with the hypothesis that Nkx‐2.5, and its level of expression, have a role in regulation and/or maintenance of specialized fate selection by embryonic myocardial cells. Anat Rec 263:307–313, 2001. © 2001 Wiley‐Liss, Inc.
Parasitism of Lacanobia oleracea (lepidoptera) by the ectoparasitic wasp, Eulophus pennicornis, disrupts the cytoskeleton of host haemocytes and suppresses encapsulation in vivo
Authors: Richards Elaine H. , Edwards John P. 
Published: August 2002

AbstractParasitism of Lacanobia oleracea larvae by the ectoparasitic wasp Eulophus pennicornis suppressed host haemocyte‐mediated encapsulation of Sephadex DEAE A‐25 beads in vivo. Beads dissected out of parasitized larvae had fewer haemocytes associated with them. Moreover, those haemocytes that were associated with the beads tended to retain a rounded configuration and rarely flattened. Similar results were obtained using in vitro encapsulation assays. SDS PAGE indicated that for parasitized and PBS injected larvae, there were some differences in the plasma proteins that bound to Sephadex DEAE A‐25 beads, suggesting that parasitism‐mediated changes to host plasma proteins might contribute to the differences in the encapsulation response occurring in these larvae. However, in vitro encapsulation assays using beads that had been pre‐incubated in plasma from parasitized and unparasitized larvae, demonstrated that major differences in the extent of encapsulation did not occur. These results, plus in vitro haemocyte attachment and spreading assays, suggest that parasitism‐mediated suppression of encapsulation is primarily due to reductions in the ability of host haemocytes to attach to (i.e., recognize) and flatten over non‐self surfaces and other haemocytes. This proposal is corroborated by staining of actin in the haemocyte cytoskeleton by FITC‐labelled phalloidin, which indicated that parasitism disrupts the formation of stress fibers and focal adhesions in plasmatocytes. By contrast, experimental injection of adult female wasp venom into unparasitized L. oleracea larvae had no significant effect on in vivo encapsulation responses or the haemocyte cytoskeleton. Arch. Insect Biochem. Physiol. 49:108–124, 2002. Published 2002 Wiley‐Liss, Inc.
Involvement of CD4+,CD57+ T cells in the disease activity of rheumatoid arthritis
Authors: Maeda Takeshi , Yamada Hisakata , Nagamine Ryuji , Shuto Toshihide , Nakashima Yasuharu , Hirata Go , Iwamoto Yukihide 
Published: August 2002

AbstractObjectiveTo evaluate the relationship between the frequency of peripheral CD57+ T cells and the physical status of rheumatoid arthritis (RA) patients, and to perform cytokine analysis of these CD57+ T cells.MethodsFour‐color fluorescence‐activated cell sorter analysis was performed to detect both cell surface antigens and intracellular cytokines in peripheral blood leukocytes, using monoclonal antibodies against CD3, CD4, CD8, CD57, interferon‐γ (IFNγ), and interleukin‐4 (IL‐4). RA patients were clinically evaluated with a modified Health Assessment Questionnaire (M‐HAQ), joint score, face scale, and visual analog scale (VAS) assessing pain and disease activity.ResultsThere was a significant correlation between the frequency of CD4+,CD57+ T cells and erythrocyte sedimentation rate (ESR), whereas a correlation was not found between the frequency of CD8+,CD57+ T cells and ESR. The frequency of CD4+,CD57+ T cells also showed a significant correlation with the mHAQ score, VAS, and face scale. Again, there was no significant correlation between the above‐mentioned clinical scores and the frequency of CD8+,CD57+ T cells. Flow cytometric analysis of intracellular cytokines revealed that 14.5% of the CD57+ T cells produced IFNγ, whereas only 2.8% of the CD57+ T cells produced IL‐4 in RA patients.ConclusionEvidence showing that the frequency of CD4+,CD57+ T cells among CD3+ cells of RA patients had a significant correlation not only with ESR but also with the physical status of the patients, and that a large proportion of the CD4+,CD57+ T cells had the capacity to produce IFNγ, strongly suggests that these CD4+,CD57+ T cells are involved in the immunopathogenesis of RA.
The prevalence and impact of managed care for persons with rheumatoid arthritis in 1994 and 1999
Authors: Yelin Edward , Trupin Laura , Katz Patricia 
Published: August 2002

AbstractObjectivesTo estimate the proportion of persons with rheumatoid arthritis (RA) in managed care and fee‐for‐service settings in 1994 and 1999, to ascertain whether there are differences in utilization between persons in the 2 systems of care in the 2 years, and to determine whether 1994 managed care status or change between 1994 and 1999 in managed care status affects outcomes.MethodsThe present study uses data from the University of California, San Francisco RA Panel Study, in which 310 patients with RA from a random sample of Northern California rheumatologists were interviewed annually between 1994 and 1999 using a structured survey instrument. We use linear and logistic regression to compare the health care utilization and outcomes of persons in managed care and fee‐for‐service after adjusting for differences in demographic and health characteristics.ResultsThe proportion of respondents in managed care increased from 60% to 79% between 1994 and 1999, including an increase from 37% to 68% among persons eligible for Medicare and an increase from 74% to 92% among persons ineligible for Medicare. With the exception of physical therapy visits in 1999, patients with RA in managed care did not report significantly different utilization of any service for RA than those in fee‐for‐service in either 1994 and 1999, including hospital admissions and joint replacement surgery. Managed care status in 1994, and change in managed care status between 1994 and 1999, were not associated with significantly different outcomes in 1999.ConclusionDespite the growth in the proportion of patients with RA in managed care, those in managed care did not differ from those in fee‐for‐service settings in utilization or outcomes.
A new model that generates Lotka's law
Authors: Huber John C. 
Published: August 2002

AbstractIn this paper, we develop a new model for a process that generates Lotka's Law. We show that four relatively mild assumptions create a process that fits five different informetric distributions: rate of production, career duration, randomness, and Poisson distribution over time, as well as Lotka's Law. By simulation, we obtain good fits to three empirical samples that exhibit the extreme range of the observed parameters. The overall error is 7% or less. An advantage of this model is that the parameters can be linked to observable human factors. That is, the model is not merely descriptive, but also provides insight into the causes of differences between samples. Furthermore, the differences can be tested with powerful statistical tools.
User perspectives on relevance criteria: A comparison among relevant, partially relevant, and not‐relevant judgments
Authors: Maglaughlin Kelly L. , Sonnenwald Diane H. 
Published: August 2002

AbstractThis study investigates the use of criteria to assess relevant, partially relevant, and not‐relevant documents. Study participants identified passages within 20 document representations that they used to make relevance judgments; judged each document representation as a whole to be relevant, partially relevant, or not relevant to their information need; and explained their decisions in an interview. Analysis revealed 29 criteria, discussed positively and negatively, that were used by the participants when selecting passages that contributed or detracted from a document's relevance. These criteria can be grouped into six categories: abstract (e.g., citability, informativeness), author (e.g., novelty, discipline, affiliation, perceived status), content (e.g., accuracy/validity, background, novelty, contrast, depth/scope, domain, citations, links, relevant to other interests, rarity, subject matter, thought catalyst), full text (e.g., audience, novelty, type, possible content, utility), journal/publisher (e.g., novelty, main focus, perceived quality), and personal (e.g., competition, time requirements). Results further indicate that multiple criteria are used when making relevant, partially relevant, and not‐relevant judgments, and that most criteria can have either a positive or negative contribution to the relevance of a document. The criteria most frequently mentioned by study participants were content, followed by criteria characterizing the full text document. These findings may have implications for relevance feedback in information retrieval systems, suggesting that systems accept and utilize multiple positive and negative relevance criteria from users. Systems designers may want to focus on supporting content criteria followed by full text criteria as these may provide the greatest cost benefit.
A view to the future of the library and information science profession: A Delphi study
Authors: Baruchson‐Arbib Shifra , Bronstein Jenny 
Published: August 2002

AbstractA Delphi study conducted in Israel during 1998–2000 examined the views of library and information science (LIS) experts on the future of the profession in light of the changes in information technology. The study focused on three areas: (a) the transition from the traditional to the virtual library; (b) the transition from the technical to user‐centered approach, and( c) the skills and the roles of the LIS professionals. The study found that most experts believe that the traditional library will continue to operate along with the virtual library. Most of the experts agree that in the future, libraries will place larger emphasis on customer services. LIS professionals will be specialists in locating, filtering, and evaluating information, and will be primary instructors in the use of new information technologies. This study's conclusions closely match those of the Kaliper project (1998–2000), which examined the change in the curricula of LIS schools.
A comparison of methods of approximations for probabilities of death for fractions of a year
Authors: Jasiulewicz Helena 
Published: August 2002

AbstractIn this paper, a comparison of methods of approximating probabilities of death over fractions of a year is given. Previous and new methods in actuarial science and demography are considered. As the measure of distance the Kolmogorov statistic and L2 are taken. The analysis was carried out using real data. Copyright © 2001 John Wiley & Sons, Ltd.
Stereoselective pharmacokinetics of desbutylhalofantrine, a metabolite of halofantrine, in the rat after administration of the racemic metabolite or parent drug
Authors: Brocks Dion R. 
Published: August 2002

AbstractThe main objective of this study was to determine the pharmacokinetics of the enantiomers of desbutylhalofantrine (DHF), a metabolite of halofantrine (HF), in the rat. Rats received either intravenous (2 mg/kg) or oral (7 mg/kg) (±)‐DHF HCl, or (±)‐HF HCl intravenously (3 mg/kg). Enantiomer concentrations in plasma were determined by a stereospecific assay. In all rats, the plasma concentrations of (+)‐DHF exceeded those of (−)‐DHF. After (±)‐DHF, the mean (+):(−) ratios of AUC0–∞ after oral and intravenous dosing were 3.7 and 2.8, respectively. After intravenous doses of DHF, the (−):(+) enantiomeric ratios of Cl and Vdss were approximately 2.8. There were no significant differences between the enantiomers in t1/2 (mean 14–23 h) or tmax (mean 10–12 h) after intravenous or oral administration of DHF. Oral bioavailability estimates of DHF enantiomers (>59%) were higher than those previously estimated for HF in the rat. The stereoselectivity in HF kinetics was not as pronounced as for DHF. It was estimated that over 44% of the dose of HF is metabolized to DHF enantiomers. It was concluded that DHF possesses a pharmacokinetic profile similar to that of HF, each possessing low values of clearance and high volume of distribution. DHF differed from HF in its degree of stereoselectivity in pharmacokinetics, and in its extent of oral bioavailability. Copyright © 2000 John Wiley & Sons, Ltd.
Complete bioavailability and lack of food‐effect on pharmacokinetics of gliclazide 30 mg modified release in healthy volunteers
Authors: Delrat P. , Paraire M. , Jochemsen R. 
Published: August 2002

AbstractA new modified release (MR) formulation containing 30 mg of gliclazide was developed to obtain a better predictable release of the active principle and to allow once‐daily dosing regimen. An absolute bioavailability study was carried out to characterise the performance of the new formulation and the food‐effect was also investigated in a separate study. Both studies were single dose, randomised, open label, two way cross over studies with a wash out period between doses. For the bioavailability study, each volunteer received 30 mg of gliclazide given either as a 1 h intravenous infusion or as a 30 mg MR tablet. For the food‐effect study, the treatment was given either fasted or 10 min after the start of a standardised Melander breakfast. Blood samples were collected up to 72 h after administrations and plasma samples assayed for gliclazide concentrations using a reverse‐phase HPLC method with UV detection. Mean absolute bioavailability of gliclazide was 97% and ranged between 79 and 110% showing complete absorption. A similar moderate to low variability was observed after IV and oral administration showing the MR formulation did not add to the overall variability which is solely due to the disposition parameters, in particular metabolism of gliclazide. No significant difference was observed in tmax, t1/2z, Cmax and AUC of gliclazide after administration of the 30 mg MR tablet under fasted and fed conditions. In conclusion, after single oral administration of a 30 mg MR tablet, gliclazide was completely absorbed both under fasted and fed conditions. A consistent and optimal release of gliclazide from this formulation leads to a low to moderate overall variability of its pharmacokinetic parameters. Diamicron 30 mg MR can be given without regards to meals i.e. before, during or after breakfast. Copyright © 2002 John Wiley & Sons, Ltd.
Effect of magnetic field exposure on calcium channel currents using patch clamp technique
Authors: Obo Mayumi , Konishi Shiro , Otaka Yoshihisa , Kitamura Satoshi 
Published: August 2002

AbstractCalcium influxes through the membrane of PC‐12D cells were measured under exposure to DC biased AC magnetic fields in resonant conditions of the ion cyclotron and the ion parametric resonance hypotheses and compared with influxes in cells without exposure to the magnetic field. After cancellation of the geomagnetic field, the cells were exposed to the horizontal fields generated by a current sheet, a planar sheet of conductor which generated a satisfactorily homogeneous horizontal magnetic field on the stage of a microscope without hindering treatment of a cell under observation. At or near any resonant conditions, no change in calcium influx could be detected under standard patch clamp conditions. Bioelectromagnetics 23:306–314, 2002. © 2002 Wiley‐Liss, Inc.
Magnetic field exposure and behavioral monitoring system
Authors: Thomas A.W. , Drost D.J. , Prato F.S. 
Published: August 2002

AbstractTo maximize the availability and usefulness of a small magnetic field exposure laboratory, we designed a magnetic field exposure system that has been used to test human subjects, caged or confined animals, and cell cultures. The magnetic field exposure system consists of three orthogonal pairs of coils 2 m square × 1 m separation, 1.751 m × 0.875 m separation, and 1.5 m × 0.75 m separation. Each coil consisted of ten turns of insulated 8 gauge stranded copper conductor. Each of the pairs were driven by a constant‐current amplifier via digital to analog (D/A) converter. A 9 pole zero‐gain active Bessel low‐pass filter (1 kHz corner frequency) before the amplifier input attenuated the expected high frequencies generated by the D/A conversion. The magnetic field was monitored with a 3D fluxgate magnetometer (0–3 kHz, ± 1 mT) through an analog to digital converter. Behavioral monitoring utilized two monochrome video cameras (viewing the coil center vertically and horizontally), both of which could be video recorded and real‐time digitally Moving Picture Experts Group (MPEG) encoded to CD‐ROM. Human postural sway (standing balance) was monitored with a 3D forceplate mounted on the floor, connected to an analog to digital converter. Lighting was provided by 12 offset overhead dimmable fluorescent track lights and monitored using a digitally connected spectroradiometer. The dc resistance, inductance of each coil pair connected in series were 1.5 m coil (0.27 Ω, 1.2 mH), 1.75 m coil (0.32 Ω, 1.4 mH), and 2 m coil (0.38 Ω, 1.6 mH). The frequency response of the 1.5 m coil set was 500 Hz at ± 463 μT, 1 kHz at ± 232 μT, 150 μs rise time from −200 μTpk to + 200 μTpk (square wave) and is limited by the maximum voltage ( ± 146 V) of the amplifier (Bessel filter bypassed). Bioelectromagnetics 22:401–407, 2001. © 2001 Wiley‐Liss, Inc.
ELF magnetic field inhibits gap junctional intercellular communication and induces hyperphosphorylation of connexin43 in NIH3T3 cells
Authors: Hu G.L. , Chiang H. , Zeng Q.L. , Fu Y.D. 
Published: August 2002

AbstractThe effects of extremely low frequency (ELF) magnetic field on gap junctional intercellular communication (GJIC), protein levels, and phosphorylation of connexin43 (Cx43) were studied in NIH3T3 cells. The suppression of GJIC by 24 h, 50 Hz, 0.8 mT ELF magnetic field, 2 h, 3 ng/ml 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA), or ELF combined with TPA treatment was confirmed by the fluorescence recovery after photobleaching (FRAP) analysis with a confocal microscope. The results showed that ELF or TPA exposure induced 50–60% inhibition of GJIC (P < 0.01). ELF combined with TPA enhanced the inhibition of GJIC. Western blot analysis using Cx43 specific antibodies showed obviously decreasing non phosphorylated Cx43 (P0) induced by ELF and/or TPA exposure. On the other hand, cells treated with ELF and/or TPA displayed a hyperphosphorylated Cx43 band (P3). However, there was no obvious changes in the level of Cx43 protein. The results implied that the P3 band appeared to result from phosphorylation of P0. But it remains possible that upon the ELF exposure P0 is converted to P1, P2 or both and that P3 is formed from P1 or P2 resulting in the observed hyperphosphorylation pattern. From the present study, we conclude that ELF magnetic field inhibits GJIC and the main mechanism is the hyperphosphorylation of Cx43. Bioelectromagnetics 22:568–573, 2001. © 2001 Wiley‐Liss, Inc.
Influence of a stationary magnetic field on water relations in lettuce seeds. Part I: Theoretical considerations
Authors: Reina Francisco Garcìa , Pascual Luis Arza 
Published: August 2002

AbstractThe theoretical calculation about the dependence of the ionic current density across the cellular membrane on the intensity of the magnetic field applied to cellular tissue is presented. This interaction induces changes in the magnitude of the ionic current density across the cellular membrane and in the ionic concentration, and it also causes alterations in the osmotic pressure and in the capacity of the cellular tissues to absorb water. The magnetic field dependence of the ionic current densities Jp (B) (positive ions) and Jn (B) (negative ions), the membrane conductivity σ (B), the ionic concentration in both membrane sides c(B), the osmotic pressure π (B), and the water uptake rate by seeds kw (B) are presented. The increase in water uptake rate due to the applied magnetic field may be the explanation of the recently reported increase in the germination speed of the seeds treated with stationary magnetic fields. Bioelectromagnetics 22:589–595, 2001. © 2001 Wiley‐Liss, Inc.
Bacterial ion channels and their eukaryotic homologues
Authors: Koprowski Piotr , Kubalski Andrzej 
Published: August 2002

AbstractDue to the relative ease of obtaining their crystal structures, bacterial ion channels provide a unique opportunity to analyse structure and function of their eukaryotic homologues. This review describes prokaryotic channels whose structures have been determined. These channels are KcsA, a bacterial homologue of eukaryotic potassium channels, MscL, a bacterial mechanosensitive ion channel and ClC0, a prokaryotic homologue of the eukaryotic ClC family of anion‐selective channels. General features of their structure and function are described with a special emphasis on the advantages that these channels offer for understanding the properties of their eukaryotic homologues. We present amino‐acid sequences of eukaryotic proteins related in their primary sequences to bacterial mechanosensitive channels. The usefulness of bacterial mechanosensitive channels for the studies on general principles of mechanosensation is discussed. BioEssays 23:1148–1158, 2001. © 2001 John Wiley & Sons, Inc.
Comparative insect developmental genetics: phenotypes without mutants
Authors: Denell Rob , Shippy Teresa 
Published: August 2002

AbstractThe last decade has seen a dramatic increase in interest in the extent to which morphological evolution depends on changes in regulatory pathways. Insects provide a fertile ground for study because of their diversity and our high level of understanding of the genetic regulation of development in Drosophila melanogaster. However, comparable genetic approaches are presently possible in only a small number of non‐Drosophilid insects. In a recent paper, Hughes and Kaufman(1) have used a new methodology, RNA interference, in the milkweed bug, Oncopeltus fasciatus, to phenocopy the effects of mutations in Hox genes. RNA interference involves the injection of double‐stranded RNA of the same sequence as the relevant mRNA resulting in a depletion of that transcript.(2) Hughes and Kaufman focused on the gnathal segments, which elaborate specialized appendages important to feeding. Their results indicate that gnathal adaptations in this bug are correlated with changes in Hox gene functions and interactions. BioEssays 23:379–382, 2001. © 2001 John Wiley & Sons, Inc.