bluuebunny/crossref_metadata_2025_split huggingface dataset:
Focal hypoxia of the obstructed rabbit bladder wall correlates with intermediate decompensation
Authors: Levin Robert M. , O'Connor Laura J. , Leggett Robert E. , Whitbeck Catherine , Chichester Paul 
Published: February 2003

AbstractAimsWe showed that partial obstruction of the rabbit bladder outlet caused decreases in detrusor blood flow that were directly proportional to the level of decompensation present. Bladder decompensation is characterized by decreases in detrusor contractility, mitochondrial function, and sarco/endoplasmic reticulum calcium ATPase (SERCA) activity in obstructed rabbits. The current study was designed to create bladder decompensation and to relate its characteristic dysfunctions to the presence or absence of hypoxia in the obstructed rabbit bladder wall. Tissue hypoxia was visualized immunohistochemically after administration of a hypoxia probe in vivo.MethodsTwelve New Zealand White rabbits were separated into two groups. The rabbits in group 1 received sham operations; the rabbits in group 2 received partial outlet obstructions by standard methods. Four weeks after surgery, each rabbit received an intraperitoneal injection of aqueous Hypoxyprobe‐1, which forms protein adducts in cells having O2 concentrations less than 14 μM. Two hours after injection, the rabbit was anesthetized and the bladder exposed through a midline incision. One full‐thickness bladder strip was cut and immediately placed in fixative for immunohistochemical recognition and visualization of Hypoxyprobe‐1–protein adducts. The remaining bladder was then excised, and three additional strips were cut for contractility studies. The remainder of the bladder was frozen for biochemical and slot‐blot analyses.ResultsBladder weight was increased fourfold after obstruction, and significant contractile and biochemical dysfunctions were observed that indicated an intermediate level of decompensation. Immunohistochemical visualization revealed focal areas of moderate to severe hypoxia in the detrusor smooth muscle (SM) and subserosal regions of these bladders. No hypoxia was observed in the obstructed bladder mucosa, consistent with the absence of biochemical dysfunction in this compartment, or in unobstructed bladders. Slot‐blot analyses confirmed the presence of significant Hypoxyprobe‐1–protein adducts in the detrusor of the obstructed bladder, whereas none were present in the control bladder detrusors.ConclusionsPartial outlet obstruction of rabbit bladders resulted in focal areas of moderate to severe hypoxia in the detrusor SM and subserosal regions concomitant with increased bladder mass, decreased contractile function, and selective metabolic dysfunctions of the SM consistent with an intermediate stage of decompensation. The metabolic characteristics of the normoxic mucosa were normal a were those of unobstructed bladders. Neurourol. Urodynam. 22:156–163, 2003. © 2003 Wiley‐Liss, Inc.
On the performance quality of repairable systems
Authors: Finkelstein M. S. 
Published: February 2003

AbstractThe quality of a system operation is characterized by decreases in time deterministic function or by a stochastic process with decreasing sample paths. Simple relations for the stationary characteristic of quality are derived in cases when the system is repairable after each failure. Methods of quality improvement are considered. The case of imperfect repair for a simplified setting is studied. Several examples are considered. Copyright © 2003 John Wiley & Sons, Ltd.
Testing for Reliability
Authors: O'Connor Patrick 
Published: February 2003

AbstractThis tutorial article describes the role of testing in the creation of reliable products. It is based upon parts of the author's book ‘Test Engineering’.Reproduced by permission of John Wiley & Sons, Ltd.The book has a web page (www.pat‐oconnor.co.uk/testengineering.htm), which provides information on and links to test organizations, standards, suppliers of equipment and facilities, etc. Copyright © 2003 John Wiley & Sons, Ltd.
Ferromagnetic vs. nonmagnetic phases of 2‐D Wigner electron crystal
Authors: Rajeswarapalanichamy R. , Iyakutti K. 
Published: February 2003

AbstractThe ferromagnetic and nonmagnetic phases of 2‐D Wigner electron crystal are investigated using a localized representation for the electrons. The ground‐state energies of ferromagnetic and nonmagnetic phases of 2‐D Wigner electron crystal are computed in the range of rs = 10–200. The low density favorable for Wigner crystallization is found to be 2.85 × 1013 e cm−2 for ferromagnetic phase and 5.07 × 1013 e cm−2 for the nonmagnetic phase of 2‐D Wigner electron crystal. For the given structure, the ground‐state energies of ferromagnetic and nonmagnetic phases are compared. It is found that the energy of the ferromagnetic phase is less than that of the nonmagnetic phase of the 2‐D Wigner electron crystal. Also, the results are compared with various experimental and theoretical works and it is found that our results are in good agreement with the experimental and other theoretical results for the 2‐D Wigner electron crystal. The structure‐dependent Wannier functions, which give proper localized representation for Wigner electrons, are employed in the calculation. The role of correlation energy is suitably taken into account. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2003
The nature of middle school learners' science content understandings with the use of on‐line resources
Authors: Hoffman Joseph L. , Wu Hsin‐Kai , Krajcik Joseph S. , Soloway Elliot 
Published: February 2003

AbstractEarly research on using the World Wide Web indicated that middle school students did not explore much and used Web tools naively. In response to these challenges, an on‐line research engine, Artemis, was designed to provide a permanent workspace and allow students access to preselective on‐line resources. This study investigated the depth and accuracy of sixth‐grade students' content understandings as well as their use of search and assess strategies when they used on‐line resources via Artemis. Eight student pairs from two science classes experienced support from teachers and used scaffolded curriculum materials while completing four on‐line inquiry units during 9 months. Multiple sources of data were collected, including video recordings of students' computer activities and conversations, students' artifacts and on‐line postings, classroom and lab video recordings, and interview transcripts. Analyses of data showed that students constructed meaningful understandings through on‐line inquiry, although the accuracy and depth of their understandings varied. The findings suggest that students might develop accurate and in‐depth understandings if they use search and assess strategies appropriately, if resources are thoughtfully chosen, and if support from the learning environment is extensively provided. This research lends evidence to questions regarding the value of students engaging in on‐line inquiry. © 2003 Wiley Periodicals, Inc. J Res Sci Teach 40: 323–346, 2003
Beyond Species: Il’ya Ivanov and His Experiments on Cross-Breeding Humans with Anthropoid Apes
Authors: Rossiianov Kirill 
Published: February 2003

ArgumentI believe that some pollutions are used as analogies for expressing a general view of the social order.Mary Douglas, Purity and Danger (Douglas 1966, 14)The possibility of crossing humans with other anthropoid species has been discussed in fiction as well as in scientific literature during the twentieth century. Professor Il’ya Ivanov’s attempt to achieve this was crucial for the beginning of organized primate research in the Soviet Union, and remains one of the most interesting and controversial experiments that was ever done on non-human primates. The possibility of removing the boundary that separates humans from other animal species, apes in particular, is loaded with important political meaning and violates cultural and ethical taboos. The history of Ivanov’s scientific experiment thus helps to reveal some of the twentieth-century’s important cultural conventions and hidden assumptions about human nature, species, and social hierarchy.
Genetic variation in cyclooxygenase 1: Effects on response to aspirin
Authors: Halushka Marc K. , Walker Linda P. , Halushka Perry V. 
Published: February 2003

BackgroundA critical clinical application of the Human Genome Project is to identify functional variation in genes related to disease or responses to xenobiotics. This study moved toward that goal by combining polymorphism detection with functional assays for the therapeutic target gene cyclooxygenase 1 (COX‐1). Cyclooxygenase 1 (prostaglandin endoperoxide G/H synthase [PTGS1]) catalyzes the metabolism of arachidonic acid to prostaglandin H2, which is subsequently metabolized to thromboxane A2.MethodsThirty‐eight healthy participants were enrolled in this study to correlate functional and genetic variation of cyclooxygenase 1. Arachidonic acid, with and without aspirin (acetylsalicylic acid) and ethanol pretreatment, was used to stimulate the formation of prostaglandin H2, measured as prostaglandin F2α (PGF2α), in human platelets. The cyclooxygenase 1 complementary deoxyribonucleic acid coding sequence and genomic deoxyribonucleic acid upstream from the cyclooxygenase 1 transcription start site (2.9 kilobases) were sequenced in 38 individuals, with 9 single‐nucleotide polymorphisms identified.ResultsTwo single‐nucleotide polymorphisms, A‐842G and C50T, were in complete linkage disequilibrium. Participants who were heterozygous for the A‐842G/C50T haplotype showed significantly (P = .01) greater inhibition of prostaglandin H2 formation by acetylsalicylic acid (30 μmol/L) compared with common allele homozygotes.ConclusionsThe discovery of a functional single‐nucleotide polymorphism in the cyclooxygenase 1 locus may ultimately improve the safe and effective use of acetylsalicylic acid by better tailoring of dosage with an individual's genetic variation.Clinical Pharmacology & Therapeutics (2003) 73, 122–130; doi: 10.1067/mcp.2003.1
Dipyridamole enhances digoxin bioavailability via P‐glycoprotein inhibition
Authors: Verstuyft Céline , Strabach Soraya , El Morabet Hakima , Kerb Reinhold , Brinkmann Ulrich , Dubert Liliane , Jaillon Patrice , Funck‐Brentano Christian , Trugnan Germain , Becquemont Laurent 
Published: February 2003

BackgroundOn the basis of in vitro studies indicating that dipyridamole is an inhibitor for the MDR1 efflux membrane transporter P‐glycoprotein, we postulated that dipyridamole could increase the bioavailability of digoxin, a P‐glycoprotein substrate.ObjectivesThe main objective was to determine whether dipyridamole alters the bioavailability of digoxin. The secondary objective was to determine whether the magnitude of the pharmacokinetic interaction was influenced by MDR1 genetic polymorphism in exon 26 (C3435T).Material and methods(1) The effect of dipyridamole on in vitro P‐glycoprotein‐mediated, polarized transport of tritium‐labeled digoxin was investigated in Caco‐2 cell monolayers. (2) Twelve healthy volunteers participated in this open, randomized, 2‐period crossover study, in which the effects of dipyridamole (300 mg/d for 3 days) versus placebo on the pharmacokinetics of a single oral dose of digoxin (0.5 mg) were compared. MDR1 genotyping (exon 26, C3435T) was determined before the study to include 6 homozygous CC and 6 homozygous TT subjects.ResultsDipyridamole inhibited [3H]digoxin transport in Caco‐2 cells with a 50% inhibitory concentration value of 1.5 ± 1.5 μmol/L. We observed a 20% and 13% increase in digoxin area under the plasma concentration‐time curve (AUC) from 0 to 4 hours and AUC from 0 to 24 hours (P < .05), respectively, during dipyridamole administration, which was consecutive to an increase in digoxin absorption. Digoxin AUC from 0 to 4 hours and AUC from 0 to 24 hours were significantly higher among subjects harboring the TT compared with the CC MDR1 genotype: 7.5 ± 1.2 ng × h × mL−1 versus 6.1 ± 0.8 ng × h × mL−1 and 20.2 ± 2.1 ng × h × mL−1 versus 16.8 ± 1.7 ng × h × mL−1, respectively (P < .05). Digoxin pharmacokinetic modifications during the dipyridamole period were similar in both genotypes.ConclusionDipyridamole is an in vitro and in vivo P‐glycoprotein inhibitor that increases intestinal digoxin absorption and digoxin plasma concentrations. In light of the modest changes in digoxin pharmacokinetics in the presence of dipyridamole, this drug interaction is probably clinically irrelevant.Clinical Pharmacology & Therapeutics (2003) 73, 51–60; doi: 10.1067/mcp.2003.8
Glucose Regulation of
Saccharomyces cerevisiae
Cell Cycle Genes
Authors: Newcomb Laura L. , Diderich Jasper A. , Slattery Matthew G. , Heideman Warren 
Published: February 2003

ABSTRACT

Nutrient-limited
Saccharomyces cerevisiae
cells rapidly resume proliferative growth when transferred into glucose medium. This is preceded by a rapid increase in
CLN3
,
BCK2
, and
CDC28
mRNAs encoding cell cycle regulatory proteins that promote progress through Start. We have tested the ability of mutations in known glucose signaling pathways to block glucose induction of
CLN3
,
BCK2
, and
CDC28
. We find that loss of the Snf3 and Rgt2 glucose sensors does not block glucose induction, nor does deletion of
HXK2
, encoding the hexokinase isoenzyme involved in glucose repression signaling. Rapamycin blockade of the Tor nutrient sensing pathway does not block the glucose response. Addition of 2-deoxy glucose to the medium will not substitute for glucose. These results indicate that glucose metabolism generates the signal required for induction of
CLN3
,
BCK2
, and
CDC28
. In support of this conclusion, we find that addition of iodoacetate, an inhibitor of the glyceraldehyde-3-phosphate dehydrogenase step in yeast glycolysis, strongly downregulates the levels
CLN3
,
BCK2
, and
CDC28
mRNAs. Furthermore, mutations in
PFK1
and
PFK2
, which encode phosphofructokinase isoforms, inhibit glucose induction of
CLN3
,
BCK2
, and
CDC28
. These results indicate a link between the rate of glycolysis and the expression of genes that are critical for passage through G
1
.
Selection on the Genes of
Euplotes crassus
Tec1 and Tec2 Transposons: Evolutionary Appearance of a Programmed Frameshift in a Tec2 Gene Encoding a Tyrosine Family Site-Specific Recombinase
Authors: Doak Thomas G. , Witherspoon David J. , Jahn Carolyn L. , Herrick Glenn 
Published: February 2003

ABSTRACT

The Tec1 and Tec2 transposons of the ciliate
Euplotes crassus
carry a gene for a tyrosine-type site-specific recombinase. The expression of the Tec2 gene apparently uses a programmed +1 frameshift. To test this hypothesis, we first examined whether this gene has evolved under purifying selection in Tec1 and Tec2. Each element carries three genes, and each has evolved under purifying selection for the function of its encoded protein, as evidenced by a dearth of nonsynonymous changes. This distortion of divergence is apparent in codons both 5′ and 3′ of the frameshift site. Thus, Tec2 transposons have diverged from each other while using a programmed +1 frameshift to produce recombinase, the function of which is under purifying selection. What might this function be? Tyrosine-type site-specific recombinases are extremely rare in eukaryotes, and Tec elements are the first known eukaryotic type II transposons to encode a site-specific recombinase. Tec elements also encode a widespread transposase. The Tec recombinase might function in transposition, resolve products of transposition (bacterial replicative transposons use recombinase or resolvase to separate joined replicons), or provide a function that benefits the ciliate host. Transposons in ciliated protozoa are removed from the macronucleus, and it has been proposed that the transposons provide this “excisase” activity.
The Kármán gait: novel body kinematics of rainbow trout swimming in a vortex street
Authors: Liao James C. , Beal David N. , Lauder George V. , Triantafyllou Michael S. 
Published: February 2003

SUMMARYMost fishes commonly experience unsteady flows and hydrodynamic perturbations during their lifetime. In this study, we provide evidence that rainbow trout Oncorhynchus mykiss voluntarily alter their body kinematics when interacting with vortices present in the environment that are not self-generated. To demonstrate this, we measured axial swimming kinematics in response to changes in known hydrodynamic wake characteristics. We compared trout swimming in the Kármán street behind different diameter cylinders (2.5 and 5 cm) at two flow speeds (2.5 and 4.5 Ls-1, where L is total body length) to trout swimming in the free stream and in the cylinder bow wake. Trout swimming behind cylinders adopt a distinctive, previously undescribed pattern of movement in order to hold station, which we term the Kármán gait. During this gait,body amplitudes and curvatures are much larger than those of trout swimming at an equivalent flow velocity in the absence of a cylinder. Tail-beat frequency is not only lower than might be expected for a trout swimming in the reduced flow behind a cylinder, but also matches the vortex shedding frequency of the cylinder. Therefore, in addition to choosing to be in the slower flow velocity offered behind a cylinder (drafting), trout are also altering their body kinematics to synchronize with the shed vortices (tuning), using a mechanism that may not involve propulsive locomotion. This behavior is most distinctive when cylinder diameter is large relative to fish length. While tuning, trout have a longer body wavelength than the prescribed wake wavelength, indicating that only certain regions of the body may need to be oriented in a consistent manner to the oncoming vortices. Our results suggest that fish can capture energy from vortices generated by the environment to maintain station in downstream flow. Interestingly, trout swimming in front of a cylinder display lower tail-beat amplitudes and body wave speeds than trout subjected to any of the other treatments, implying that the bow wake may be the most energetically favorable region for a fish to hold station near a cylinder.
The verdict on jury trials for juveniles: the effects of defendant's age on trial outcomes
Authors: Warling Diane , Peterson‐Badali Michele 
Published: February 2003

AbstractWith the progression to more adult‐like policies and procedures for youth in the justice system, the right to a jury trial has been extended to young offenders. These youth would not be tried by a jury of their peers, however, but by a jury of adults. The concern is that adult jurors may hold negative attitudes about youth that might influence their decision making in a case involving a young defendant. Two studies examined whether and under what conditions defendant's age affects jurors' decisions about the guilt and sentencing of an accused. In study 1, data were gathered from two samples of jury eligible adults: one university sample and one public sample. Mock jurors read written transcripts of a trial involving a defendant who was presented as either 13, 17, or 25 years of age. Results indicated that the defendant's age had no effect on mock jurors' verdict or their ratings of defendant guilt. However, younger defendants were granted shorter sentences than the adult defendants. In study 2, mock jurors read the same trial presented in study 1 but were asked to deliberate about the case and render group verdicts. These group verdicts did not differ significantly by defendant's age. Age‐related themes that emerged from group deliberations were identified, and results indicated that age tended to be used as a mitigating factor in favor of youth rather than against them. These findings are discussed in terms of their implications for youth justice policy and practice. Copyright © 2003 John Wiley & Sons, Ltd.
Reduction of flobufen in pig hepatocytes: Effect of pig breed (domestic, wild) and castration
Authors: Skálová Lenka , Wsól Vladimír , Baliharová Vendula , Král Radim , Szotáková Barbora , Velík Jakub , Lamka Jirí 
Published: February 2003

AbstractKnowledge of the biotransformation processes of veterinary drugs and food supplements in food‐producing animals is increasingly important. Residual levels of parent compounds or their metabolites in food of animal origin may differ with the breed, breeding conditions, and gender of animals. The nonsteroidal antiinflammatory drug flobufen, 4‐(2′,4′‐difluorobiphenyl‐4‐yl)‐2‐methyl‐4‐oxobutanoic acid (racemic or its individual enantiomers) was used as a model to evaluate differences in activity, stereoselectivity, and stereospecificity of reductases in primary cultures of hepatocytes from intact male or castrated male domestic pigs (Sus scrofa domestica) or male wild pig (Sus scrofa scrofa). Time‐dependent consumption of flobufen enantiomers and formation of dihydroflobufen (DHF) diastereoisomers as their principal metabolites in hepatocytes were measured using chiral HPLC. Flobufen reduction in hepatocytes from all three experimental groups of animals was stereoselective ((+)‐R‐flobufen was predominantly metabolized) and stereospecific (2R;4S‐DHF and 2S;4S‐DHF diastereoisomers were preferentially formed). Flobufen reductases activity in male domestic pigs was 30 times higher compared to castrated pigs. Flobufen reductases activity was similar in domestic and wild pigs. The stereospecificity and stereoselectivity of DHF production did not significantly differ with breed or castration of animal. Chiral inversion of flobufen enantiomers was also studied and differences between castrated and intact male pigs were seen. Chirality 15:213–219, 2003. © 2003 Wiley‐Liss, Inc.
Incontinent ileovesicostomy in the management of neurogenic bladder dysfunction
Authors: Gauthier Anthony R. , Winters J. Christian 
Published: February 2003

AbstractAimsTo report outcome and urodynamic follow‐up of incontinent ileovesicostomy in quadriplegic patients with neurogenic bladder.MethodsSeven patients (five male, two female; mean age, 33.7 yr) with neurogenic bladder underwent ileovesicostomy for management of leakage or complications of chronic catheter drainage. Five had chronic indwelling catheters: three suprapubic and two urethral. Preoperatively, all had upper tract evaluation and videourodynamics. All seven patients had detrusor hyperreflexia. Preoperative detrusor leak point pressures averaged 42.7 cm H2O. Two females had intrinsic sphincteric deficiency from prolonged Foley catheter drainage. Ileovesicostomy involves isolation of a 15—20‐cm segment of terminal ileum. The proximal 6–8 cm of this segment is opened on the antimesenteric border. The dome of the bladder is opened widely in a transverse manner and the proximal portion of the bowel is sutured onto the bladder. The distal portion of the ileum remains tubularized and becomes the stoma.ResultsThere were no intraoperative complications. Operative time averaged 159 minutes. Associated procedures included removal of bladder calculus (n = 1), pubovaginal sling (n = 2), and Marshall Marchetti Krantz suspension (n = 1). Mean blood loss was <200 cc in six patients. Mean hospital stay was 8 days. Complications in two patients included: fascial stenosis requiring stoma revision (n = 1), wound infection (n = 1), and postoperative ileus (n = 1). Mean follow‐up was 37.4 months. Postoperatively, mean detrusor leak point pressures were 16.7 cm H2O (P = 0.0061). Patient satisfaction is high with only one complaint of occasional difficulty fitting the appliance.ConclusionsIleovesicostomy is an effective method of urinary drainage in quadriplegic patients. Detrusor leak point pressures were lowered, and upper tracts were preserved. No long‐term complications were encountered. Neurourol. Urodynam. 22:142–146, 2003. © 2003 Wiley‐Liss, Inc.