bluuebunny/crossref_metadata_2025 huggingface dataset:
Cytolytic activity and regulatory functions of inhibitory NK cell receptor–expressing T cells expanded from granulocyte colony-stimulating factor–mobilized peripheral blood mononuclear cells
Authors: Tanaka Junji , Toubai Tomomi , Tsutsumi Yutaka , Miura Yoko , Kato Naoko , Umehara Shintarou , Kahata Kaoru , Mori Akio , Toyoshima Nobuyasu , Ota Shuichi , Kobayashi Takahiko , Kobayashi Masanobu , Kasai Masaharu , Asaka Masahiro , Imamura Masahiro
Published: April 2004

Inhibitory natural killer cell receptor (NKR)–expressing cells may induce a graft-versus-leukemia/tumor (GVL/T) effect against leukemic cells and tumor cells that have mismatched or decreased expression of HLA class I molecules and may not cause graft-versus-host disease (GVHD) against host cells that have normal expression of HLA class I molecules. In our study, we were able to expand inhibitory NKR (CD94/NKG2A)–expressing CD8+ T cells from granulocyte colonystimulating factor (G-CSF)–mobilized peripheral blood mononuclear cells (G-PBMCs) by more than 500-fold using stimulation by an anti-CD3 monoclonal antibody with interleukin 15 (IL-15). These expanded and purified CD94-expressing cells attacked various malignant cell lines, including solid cancer cell lines, as well as the patients' leukemic cells but not autologous and allogeneic phytohemagglutinin (PHA) blasts in vitro. Also, these CD94-expressing cells prevented the growth of K562 leukemic cells and CW2 colon cancer cells in NOD/SCID mice in vivo. On the other hand, the CD94-expressing cells have low responsiveness to alloantigen in mixed lymphocyte culture (MLC) and have high transforming growth factor (TGF)–β1– but low IL-2– producing capacity. Therefore, CD94-expressing cells with cytolytic activity against the recipient's leukemic and tumor cells without enhancement of alloresponse might be able to be expanded from donor G-PBMCs.
Fibrin-incorporated vitronectin is involved in platelet adhesion and thrombus formation through homotypic interactions with platelet-associated vitronectin
Authors: Wu Ya-Ping , Bloemendal Haiko J. , Voest Emile E. , Logtenberg Ton , de Groot Philip G. , Gebbink Martijn F. B. G. , de Boer Hetty C.
Published: April 2004

When a blood clot is formed, vitronectin (VN) is incorporated. Here we studied the consequence of VN incorporation for platelet interactions under flow. Perfusion of whole blood over a fibrin network, formed from purified fibrinogen, resulted in approximately 20% surface coverage with blood platelets. Incorporation of purified multimeric VN into the fibrin network resulted in a 2-fold increase in surface coverage with platelets and in enhancement of platelet aggregate formation. A human monoclonal antibody (huMab VN18), directed against the multimeric form of VN, inhibited platelet adhesion to the combined fibrin/VN matrix to the level of adhesion on fibrin alone. This inhibition was also shown when whole blood was perfused over a plasma-derived clot. Surprisingly, the inhibitory action of the antibody was not directed toward VN incorporated into the fibrin network but toward VN released from the platelets. We conclude that VN-potentiated platelet-clot interaction requires VN in the clot and multimeric VN bound to the platelet surface. Our results provide evidence that homotypic VN interactions contribute to platelet adhesion and aggregation to a blood clot. This report demonstrates for the first time that self-assembly of VN may provide a physiologically relevant contribution to platelet aggregation on a blood clot.
Case report: Purple urine bag syndrome
Authors: Ribeiro Joaquim Palmeiro , Marcelino Paulo , Marum Susan , Fernandes Ana Paula , Grilo Ana
Published: April 2004

Purple urine bag syndrome (PUBS) was first reported in 1978. PUBS is rare, occurs predominantly in constipated women, chronically catheterized and associated with some bacterial urinary infections that produce sulphatase/phosphatase. The etiology is due to indigo (blue) and indirubin (red) or to their mixture that becomes purple. A chain reaction begins in the gastrointestinal tract with tryptophan as described in the article.
Growth Hormone Alters Epidermal Growth Factor Receptor Binding Affinity via Activation of Extracellular Signal-Regulated Kinases in 3T3-F442A Cells
Authors: Huang Yao , Chang Yongchang , Wang Xiangdong , Jiang Jing , Frank Stuart J.
Published: April 2004

Epidermal growth factor receptor (EGFR) is a transmembrane protein that binds EGF in its extracellular domain and initiates signaling via intrinsic tyrosine kinase activity in its cytoplasmic domain. EGFR is important in development, cellular proliferation, and cancer. GH is a critical growthpromoting and metabolic regulatory hormone that binds the GH receptor, thereby engaging various signaling pathways, including ERKs. Prior studies suggest cross-talk between the GH receptor and EGFR signaling systems. Using the GH- and EGF-responsive 3T3-F442A preadipocyte, we previously observed that GH, in addition to causing EGFR tyrosine phosphorylation, also induced EGFR phosphorylation that was detected by PTP101, an antibody reactive with ERK consensus phosphorylation sites. This latter phosphorylation was prevented by pretreatment with MAPK kinase (MEK)1 inhibitors, suggesting ERK pathway dependence. Furthermore, GH cotreatment with EGF markedly slowed EGF-induced EGFR degradation and down-regulation, thereby potentiating EGF-induced EGFR signaling. These effects were also MEK1 dependent and suggested ERK pathway-dependent influence of GH on EGF-induced EGFR postendocytic trafficking and signaling. We now explore the impact of GH on cell surface binding of EGF in 3T3-F442A cells. We found that GH pretreatment caused transient, but substantial, lessening of 125I-EGF binding. Competitive binding experiments revealed that the decreased binding was primarily due to decreased affinity, rather than a change in the number of EGF binding sites. The effect of GH on EGF binding was concentration dependent and temporally correlated with GH-induced ERK activation and EGFR PTP101-reactive phosphorylation. Blockade of the MEK1/ERK but not the protein kinase C pathway, prevented GH’s effects on EGF binding, and our results indicate that the mechanisms of GH- and phorbol-12-myristate-13-acetateinduced inhibition of EGF binding differ substantially. Overall, our findings suggest that GH can modulate both EGF binding kinetics and the EGFR’s postbinding signaling itinerary in a MEK1/ERK pathway-dependent fashion.
The Clinically Inapparent Adrenal Mass: Update in Diagnosis and Management
Authors: Mansmann Georg , Lau Joseph , Balk Ethan , Rothberg Michael , Miyachi Yukitaka , Bornstein Stefan R.
Published: April 2004

Clinically inapparent adrenal masses are incidentally detected after imaging studies conducted for reasons other than the evaluation of the adrenal glands. They have frequently been referred to as adrenal incidentalomas. In preparation for a National Institutes of Health State-of-the-Science Conference on this topic, extensive literature research, including Medline, BIOSIS, and Embase between 1966 and July 2002, as well as references of published metaanalyses and selected review articles identified more than 5400 citations. Based on 699 articles that were retrieved for further examination, we provide a comprehensive update of the diagnostic and therapeutic approaches focusing on endocrine and radiological features as well as surgical options. In addition, we present recent developments in the discovery of tumor markers, endocrine testing for subclinical disease including autonomous glucocorticoid hypersecretion and silent pheochromocytoma, novel imaging techniques, and minimally invasive surgery. Based on the statements of the conference, the available literature, and ongoing studies, our aim is to provide practical recommendations for the management of this common entity and to highlight areas for future studies and research.
Paradox lost: answers and questions about walking on water
Authors: Denny Mark W.
Published: April 2004

The mechanism by which surface tension allows water striders (members of the genus Gerris) to stand on the surface of a pond or stream is a classic example for introductory classes in animal mechanics. Until recently,however, the question of how these insects propelled themselves remained open. One plausible mechanism–creating momentum in the water via the production of capillary waves–led to a paradox: juvenile water striders move their limbs too slowly to produce waves, but nonetheless travel across the water's surface. Two recent papers demonstrate that both water striders and water-walking spiders circumvent this paradox by foregoing any reliance on waves to gain purchase on the water. Instead they use their legs as oars, and the capillary `dimple' formed by each leg acts as the oar's blade. The resulting hydrodynamic drag produces vortices in the water, and the motion of these vortices imparts the necessary fluid momentum. These studies pave the way for a more thorough understanding of the complex mechanics of walking on water, and an exploration of how this intriguing form of locomotion scales with the size of the organism.
Dynamin-association with agonist-mediated sequestration of beta-adrenergic receptor in single-cell eukaryoteParamecium
Authors: Wiejak Jolanta , Surmacz Liliana , Wyroba Elzbieta
Published: April 2004

Evidence that dynamin is associated with the sequestration of the Paramecium β2-adrenergic receptor (βAR)immunoanalogue is presented. We previously reported a dramatic change in the distribution of βAR analogue in the subcellular fractions upon isoproterenol treatment: it is redistributed from the membraneous to the cytosolic fraction, as revealed by quantitative image analysis of western blots. Here we confirm and extend this observation by laser scanning confocal and immunogold electron microscopy. In the presence of isoproterenol (10μmol l–1) βAR translocated from the cell surface into dynamin-positive vesicles in the cytoplasmic compartment, as observed by dual fluorochrome immunolabeling in a series of the confocal optical sections. Colocalization of βAR and dynamin in the tiny endocytic vesicles was detected by further electron microscopic studies.

Generally receptor sequestration follows its desensitization, which is initiated by receptor phosphorylation by G-protein-coupled receptor kinase. We cloned and sequenced the gene fragment of 407 nucleotides homologous to theβ-adrenergic receptor kinase (βARK): its deduced amino acid sequence shows 51.6% homology in 126 amino acids that overlap with the human βARK2(GRK3), and may participate in Paramecium βAR desensitization.

These results suggest that the molecular machinery for the desensitization/sequestration of the receptor immunorelated to vertebrateβAR exists in unicellular Paramecium.
Nitrogen stress causes unpredictable enrichments of 15N in two nectar-feeding bat species
Authors: Voigt Christian C. , Matt Felix
Published: April 2004

We estimated the effect of nitrogen stress on the nitrogen isotope enrichments in wing membrane and blood of two nectar-feeding bats(Glossophaga soricina and Leptonycteris curasoae) by offering a nitrogen-poor diet with a high δ15N andδ 13C. Before the experiment, bats were sustained on a normal diet with a low δ15N and δ13C. Under this first food regime, the fractionation of nitrogen isotopes averaged 3.1‰δ 15N for blood and 4.4‰ δ15N for wing membrane, which was almost twice as high as the corresponding fractionation of carbon isotopes. After switching to the nitrogen-poor diet, the enrichment of heavy isotopes increased for both elements in all tissues under study. The recently published estimates of half-life of carbon isotopes indicated a low turnover rate of carbon in wing membrane and blood and an almost constant half-life over varying losses of body mass. The estimates of half-life of nitrogen were two to six times higher than those of carbon. We argue that this discrepancy was caused by the mixing of nitrogen isotopes from internal and external sources. The mixing effect was probably negligible for carbon as the amount of ingested carbon outweighed the amount of mobilized carbon from internal sources. A correlation between the estimated turnover rates of nitrogen and losses of body masses was probably obscured by the additional fractionation of nitrogen isotopes in catabolic animals. We conclude that the interpretation of nitrogen isotope data of free-ranging animals is difficult when the animal's diet is changing to a critical nitrogen content.
Mechanisms of K+ transport across basolateral membranes of principal cells in Malpighian tubules of the yellow fever mosquito,Aedes aegypti
Authors: Scott Brett N. , Yu Ming-Jiun , Lee Lenora W. , Beyenbach Klaus W.
Published: April 2004

The mechanisms of K+ entry from the hemolymph into principal cells of Malpighian tubules were investigated in the yellow fever mosquito, Aedes aegypti. The K+ channel blocker Ba2+ (5 mmol l–1) significantly decreased transepithelial (TEP) fluid secretion (Vs) from 0.84 nl min–1 to 0.37 nl min–1 and decreased the K+ concentration in secreted fluid from 119.0 mmol l–1 to 54.3 mmol l–1 with no change in the Cl– concentration. Even though the Na+ concentration increased significantly from 116.8 mmol l–1 to 144.6 mmol l–1, rates of TEP ion secretion significantly decreased for all three ions. In addition,Ba2+ had the following significant electrophysiological effects: it depolarized the TEP voltage (Vt) from 19.4 mV to 17.2 mV,increased the TEP resistance (Rt) from 6.4 kΩcm to 6.9 kΩcm, hyperpolarized the basolateral membrane voltage of principal cells (Vbl) from –75.2 mV to –88.2 mV and increased the cell input resistance from 363.7 kΩ to 516.3 kΩ. These effects of Ba2+ reflect the block of K+ channels that, apparently, are also permeable to Na+. Bumetanide (100μmol l–1) had no effect on TEP fluid secretion and electrical resistance but significantly decreased TEP K+ secretion,consistent with the inhibition of electroneutral Na+/K+/2Cl– cotransport. TEP Na+ secretion significantly increased because other Na+entry pathways remained active. Bumetanide plus Ba2+ completely inhibited TEP electrolyte and fluid secretion, with fast and slow kinetics reflecting the Ba2+ block of basolateral membrane K+channels and the inhibition of Na+/K+/2Cl– cotransport, respectively. The single and combined effects of Ba2+ and bumetanide suggest that(1) K+ channels and Na+/K+/2Cl– cotransport are the primary mechanisms for bringing K+ into cells, (2) K+ channels mediate a significant Na+ influx, (3) Na+ has as many as four entry pathways and (4) the mechanisms of TEP K+ and Na+ secretion are coupled such that complete block of TEP K+ renders the epithelium unable to secrete Na+.
Wing inertia and whole-body acceleration: an analysis of instantaneous aerodynamic force production in cockatiels (Nymphicus hollandicus)flying across a range of speeds
Authors: Hedrick Tyson L. , Usherwood James R. , Biewener Andrew A.
Published: April 2004

We used a combination of high-speed 3-D kinematics and three-axis accelerometer recordings obtained from cockatiels flying in a low-turbulence wind tunnel to characterize the instantaneous accelerations and, by extension,the net aerodynamic forces produced throughout the wingbeat cycle across a broad range of flight speeds (1–13 m s–1). Our goals were to investigate the variation in instantaneous aerodynamic force production during the wingbeat cycle of birds flying across a range of steady speeds, testing two predictions regarding aerodynamic force generation in upstroke and the commonly held assumption that all of the kinetic energy imparted to the wings of a bird in flapping flight is recovered as useful aerodynamic work. We found that cockatiels produce only a limited amount of lift during upstroke (14% of downstroke lift) at slower flight speeds(1–3 m s–1). Upstroke lift at intermediate flight speeds (7–11 m s–1) was moderate, averaging 39% of downstroke lift. Instantaneous aerodynamic forces were greatest near mid-downstroke. At the end of each half-stroke, during wing turnaround,aerodynamic forces were minimal, but inertial forces created by wing motion were large. However, we found that the inertial power requirements of downstroke (minimum of 0.29±0.10 W at 7 m s–1 and maximum of 0.56±0.13 W at 1 m s–1) were consistent with the assumption that nearly all wing kinetic energy in downstroke was applied to the production of aerodynamic forces and therefore should not be added separately to the overall power cost of flight. The inertial power requirements of upstroke (minimum of 0.16±0.04 W at 7 m s–1 and maximum of 0.35±0.11 W at 1 m s–1) cannot be recovered in a similar manner, but their magnitude was such that the power requirements for the upstroke musculature(minimum of 54±13 W kg–1 at 7 m s–1and maximum of 122±35 W at 1 m s–1) fall within the established range for cockatiel flight muscle (<185 W kg–1).
Marked load-bearing ability ofMytilussmooth muscle in both active and catch states as revealed by quick increases in load
Authors: Mukou Masao , Kishi Hirohiko , Shirakawa Ibuki , Kobayashi Takakazu , Tominaga Katsutoshi , Imanishi Haruka , Sugi Haruo
Published: April 2004

The anterior byssal retractor muscle (ABRM) of the bivalve Mytilus edulis shows a prolonged tonic contraction, called the catch state. To investigate the catch mechanism, details of which still remain obscure, we studied the mechanical responses of ABRM fibres to quick increases in load applied during maximum active isometric force (P0)generation and during the catch state. The mechanical response consisted of three components: (1) initial extension of the series elastic component (SEC),(2) early isotonic fibre lengthening with decreasing velocity, and (3) late steady isotonic fibre lengthening. The ABRM fibres could bear extremely large loads up to 10–15P0 for more than 30–60 s,while being lengthened extremely slowly. If, on the other hand, quick increases in load were applied during the early isometric force development,the ABRM fibres were lengthened rapidly (`give') under loads of 1.5–2P0. These findings might possibly be explained by two independent systems acting in parallel with each other; one is the actomyosin system producing active shortening and active force generation,while the other is the load-bearing system responsible for the extremely marked load-bearing ability as well as the maintenance of the catch state.
Stress gene (hsp70) sequences and quantitative expression inMilnesium tardigradum(Tardigrada) during active and cryptobiotic stages
Authors: Schill Ralph O. , Steinbrück Günther H. B. , Köhler Heinz-R.
Published: April 2004

The eutardigrade Milnesium tardigradum can undergo cryptobiosis,i.e. entry into a reversible ametabolic stage induced by dehydration, cooling and, probably, osmotic and anoxic stress. For the first time in tardigrades,we described partial sequences of three heat-shock protein (hsp70family) genes and examined gene expression on the way from an active to a cryptobiotic and back to an active stage again. Results showed different patterns of gene expression in the hsp70 isoforms. All three isoforms seem to be true heat-shock proteins since transcription could be clearly enhanced by temperature elevation. Isoform 1 and, at a lower level, isoform 3 do not seem to have a specific function for cryptobiosis. By contrast,transcription of isoform 2 is significantly induced in the transitional stage between the active and the cryptobiotic stage, resulting in a comparatively high mRNA copy number also during cryptobiosis. This pattern of induction implies that isoform 2 is the most relevant hsp70 gene for M. tardigradum individuals entering the cryptobiotic stage.
Effects of mass distribution on the mechanics of level trotting in dogs
Authors: Lee David V. , Stakebake Eric F. , Walter Rebecca M. , Carrier David R.
Published: April 2004

The antero–posterior mass distribution of quadrupeds varies substantially amongst species, yet the functional implications of this design characteristic remain poorly understood. During trotting, the forelimb exerts a net braking force while the hindlimb exerts a net propulsive force. Steady speed locomotion requires that braking and propulsion of the stance limbs be equal in magnitude. We predicted that changes in body mass distribution would alter individual limb braking–propulsive force patterns and we tested this hypothesis by adding 10% body mass near the center of mass, at the pectoral girdle, or at the pelvic girdle of trotting dogs. Two force platforms in series recorded fore- and hindlimb ground reaction forces independently. Vertical and fore–aft impulses were calculated by integrating individual force–time curves and Fourier analysis was used to quantify the braking–propulsive (b–p) bias of the fore–aft force curve. We predicted that experimental manipulation of antero–posterior mass distribution would (1) change the fore–hind distribution of vertical impulse when the limb girdles are loaded, (2) decrease the b–p bias of the experimentally loaded limb and (3) increase relative contact time of the experimentally loaded limb, while (4) the individual limb mean fore–aft forces (normalized to body weight + added weight) would be unaffected. All four of these results were observed when mass was added at the pelvic girdle,but only 1, 3 and 4 were observed when mass was added at the pectoral girdle. We propose that the observed relationship between antero–posterior mass distribution and individual limb function may be broadly applicable to quadrupeds with different body types. In addition to the predicted results,our data show that the mechanical effects of adding mass to the trunk are much more complex than would be predicted from mass distribution alone. Effects of trunk moments due to loading were evident when mass was added at the center of mass or at the pelvic girdle. These results suggest a functional link between appendicular and axial mechanics via action of the limbs as levers.
Strouhal numbers and optimization of swimming by odontocete cetaceans
Authors: Rohr Jim J. , Fish Frank E.
Published: April 2004

Swimming efficiencies of fish and cetaceans have been related to a certain synchrony between stroke cycle frequency, peak-to-peak tail/fluke amplitude and mean swimming speed. These kinematic parameters form a non-dimensional wake parameter, referred to as a Strouhal number, which for the range between 0.20 and 0.40 has been associated with enhanced swimming efficiency for fish and cetaceans. Yet to date there has been no direct experimental substantiation of what Strouhal numbers are preferred by swimming cetaceans. To address this lack of data, a total of 248 Strouhal numbers were calculated for the captive odontocete cetaceans Tursiops truncatus, Pseudorca crassidens, Orcinus orca, Globicephala melaena, Lagenorhynchus obliquidens and Stenella frontalis. Although the average Strouhal number calculated for each species is within the accepted range, considerable scatter is found in the data both within species and among individuals. A greater proportion of Strouhal values occur between 0.20 and 0.30 (74%) than the 0.25–0.35(55%) range predicted for maximum swimming efficiency. Within 0.05 Strouhal increments, the greatest number of Strouhal values was found between 0.225 and 0.275 (44%). Where propulsive efficiency data were available (Tursiops truncatus, Pseudorca crassidens, Orcinus orca), peak swimming efficiency corresponded to this same Strouhal range. The odontocete cetacean data show that, besides being generally limited to a range of Strouhal numbers between 0.20 and 0.40, the kinematic parameters comprising the Strouhal number provide additional constraints. Fluke-beat frequency normalized by the ratio of swimming speed to body length was generally restricted from 1 to 2, whereas peak-to-peak fluke amplitude normalized by body length occurred predominantly between 0.15 and 0.25. The results indicate that the kinematics of the propulsive flukes of odontocete cetaceans are not solely dependent on Strouhal number, and the Strouhal number range for odontocete cetaceans occurs at slightly (∼20%) lower values than previously predicted for maximum swimming efficiency.
Visual acuity of fly photoreceptors in natural conditions - dependence on UV sensitizing pigment and light-controlling pupil
Authors: Stavenga Doekele G.
Published: April 2004

The effect of the UV-absorbing sensitizing pigment of fly photoreceptors on absolute, spectral and angular sensitivity was investigated with a wave-optics model for the facet lens-rhabdomere system. When sky light was used as a UV-rich light source, one sensitizing pigment molecule per rhodopsin increased the photoreceptor absorption by 14-18% with respect to pure rhodopsin, whilst two sensitizing pigment molecules per rhodopsin increased the absorption by 20-27%. Upon light adaptation, when the pupil mechanism is activated,photoreceptor absorption decreases; in the housefly, Musca, by up to 6-fold. The fully light-adapted pupil diminishes the photoreceptor's acceptance angle by a factor of ∼0.6 due to selective absorption of higher order waveguide modes. Spatial acuity of dark-adapted photoreceptors is more or less constant throughout the visual wavelength range, including the UV,because the waveguide optics of the rhabdomere compromise acuity least at wavelengths most limited by diffraction of the facet lens. Diffraction is not the general limiting factor causative for UV sensitivity of insect eyes. Visual acuity is governed by diffraction only with a fully light-adapted pupil, which absorbs higher waveguide modes. Closure of the blue-absorbing pupil causes a UV-peaking spectral sensitivity of fly photoreceptors. The sensitizing pigment does not play an appreciable role in modifying spatial acuity, neither in the dark- nor the light-adapted state, due to the dominant contribution of green light in natural light sources.
Expression and polarity reversal of V-type H+-ATPase during the mineralization–demineralization cycle in Porcellio scabersternal epithelial cells
Authors: Ziegler Andreas , Weihrauch Dirk , Hagedorn Monica , Towle David W. , Bleher Reiner
Published: April 2004

The formation and resorption of CaCO3 by epithelial cell layers require epithelial transport of protons. We used the anterior sternal epithelium of the terrestrial isopod Porcellio scaber as a model to study the expression pattern and immunolocalization of a V-type H+-ATPase during the mineralization and demineralization of intermittent CaCO3 deposits. Semiquantitative RT-PCR revealed that the expression of the V-type H+-ATPase increases from non Ca2+-transporting control stages to the stages of CaCO3deposit formation and resorption. In the Ca2+-transporting stages the expression was larger in the anterior than in the posterior sternal epithelium, which is not involved in deposit formation and transports just moderate amounts of CaCO3. Immunocytochemistry of the B-subunit of the V-type H+-ATPase in the anterior sternal epithelium reveals an increase in the abundance of the protein within the basolateral membrane, from undetectable to strong signals in the control stage to the stages of CaCO3 deposit formation, respectively. From the stage of CaCO3 deposit formation to that of CaCO3 resorption the signal decreased within the basolateral plasma membrane and increased within the apical plasma membrane. For the first time the results indicate a contribution of a V-type H+-ATPase to CaCO3 deposition and a reversal of its polarity from the basolateral to the apical plasma membrane compartment within the same cells.
Variation in activity rates of consultant surgeons and the influence of reward structures in the English NHS
Authors: Bloor Karen , Maynard Alan , Freemantle Nick
Published: April 2004

Objectives: To explore variation in the National Health Service (NHS) activity rates of consultant surgeons, and examine whether activity is dependent upon the type of contract held and/or bonus payments, after accounting for age and other consultant and hospital characteristics.

Methods: NHS Hospital Episode Statistics (HES) for England were used in combination with workforce data in five surgical specialties in 1998/99 and 1999/2000. Descriptive statistics were used to explore variation in activity rates. A multi-level model was used to analyse the relationship between NHS contract and bonus payments, and activity.

Results: There is considerable variation in activity rates of English NHS consultant surgeons, with and without adjustment for casemix. Interquartile variation shows that the top 25% of consultants have activity rates 60 to 85% higher than the bottom 25%. A multi-level model indicates that consultant surgeons with a 'maximum part-time' contract have significantly higher activity rates than those with a full time contract (129 more finished consultant episodes (FCEs) per year, 95% CI 97-160). Consultant surgeons who hold discretionary salary points undertake significantly more activity than those without (95 FCEs, 95% CI 62-128). Those with a distinction award (a type of bonus payment) have a tendency towards higher activity rates, but this does not reach statistical significance (48 FCEs, 95% CI -4 to 103).

Conclusions: 'Maximum part-time contract' status is associated with higher absolute activity rates among NHS surgeons. Rich data sources like HES merit careful exploration and increased use as an essential first step in measuring and managing variations in specialists' performance.
Use of, and attitudes to, clinical priority assessment criteria in elective surgery in New Zealand
Authors: McLeod Deborah , Morgan Sonya , McKinlay Eileen , Dew Kevin , Cumming Jackie , Dowell Anthony , Love Tom
Published: April 2004

Objectives: To describe the ways patients access elective surgery in New Zealand, and to understand the use of, and attitudes to, clinical priority assessment criteria (CPAC) in determining access to publicly funded elective surgery.

Methods: A qualitative study in selected New Zealand localities. A purposive sample of general practitioners, surgeons and administrators in publicly funded hospitals were interviewed. Data were analysed by a process of thematic analysis.

Results: Sixty-five interviews were completed. General practitioners had a key role in determining which patients were seen in the public sector and, by utilising strategies to actively advocate for patients, influenced both waiting times for first assessment by surgeons and for surgery. CPAC had been developed as decision support guides with the intention that they would provide transparency and equity in determining access. However, there was variation in the way CPAC were being used both in score construction and in the influence of the score on access to surgery. The management of the hospital system also limited the extent to which CPAC could be used to prioritise patients for surgery.

Conclusions: Variability in the use of CPAC tools meant that at the time of the study they did not provide a transparent and equitable method of determining access to surgery. This highlights the difficulties in developing and implementing CPAC and suggests that further development is difficult in the absence of evidence to identify patients who will benefit the most from surgery.
Counting in-hospital deaths in England: a comparison of hospital computer systems and mortuary registers
Authors: Mohammed Mohammed , Raftery James , LeatherBarrow Martin , Harley Mike , Marshall Tom
Published: April 2004

Objectives: In-hospital death counts derived from hospital computer systems have been used in England by an independent company, 'Dr Foster', to rank the quality of care of hospitals, but the validity of the underlying data remains unclear. This study compares counts of in-hospital deaths using two different sources - the hospital computer system and the mortuary register - to determine: whether the counts of in-hospital deaths from these two sources differed; qualitative explanations for possible sources of discrepancy; the direction and magnitude of any differences; and the possible impact of any differences on the Dr Foster rankings.

Methods: The four highest and the four lowest National Health Service (NHS) hospitals in the West Midlands, as ranked by Dr Foster, participated. Each hospital was asked to compare the monthly counts of in-hospital deaths from the hospital computer system and the hospital mortuary register for the fiscal year 1999/2000.

Results: One hospital, with a computerised mortuary register, had identical counts of in-hospital deaths. Two hospitals reported 4-5% more deaths and four hospitals reported fewer deaths (0.4-7%) from their hospital computer system than from their mortuary register. These differences were not large enough to change their Dr Foster rankings. Wide discrepancies were noted on a monthly basis (range: -13.9% to +15.9%).

Discussion: The differences between the two sources of in-hospital death counts were not large enough to influence the Dr Foster ranks but were sufficient to raise concern about the validity and completeness of mortality data in the NHS.
Lessons from New Zealand for England's NHS Foundation Trusts
Authors: Howell Bronwyn
Published: April 2004

The legislation to devolve responsibility for the management and operation of England's top-performing NHS hospitals to community-owned NHS Foundation Trusts raises several issues relating to the challenges posed to governance structures by private non-profit ownership and control of assets used to provide government-financed services. Building upon the lessons learned from devolution of public hospital governance in New Zealand to boards at arm's-length from central control during the 1990s, this paper analyses the English NHS hospital changes. Whilst local political accountability and competition between hospitals indicate that the English reforms may be more successful in meeting patients' needs more efficiently than the New Zealand reforms, the English proposals may be compromised by the ability of staff to become members of Trusts, boards bearing risks of decisions outside their control whilst simultaneously being insulated from the consequences of their decisions by a 'soft budget constraint', and conflicts of interest as boards simultaneously act as agents of both central regulators and local beneficiaries.
Entrepreneurs’ Access to Private Equity in China: The Role of Social Capital
Authors: Batjargal Bat , Liu Mannie (Manhong)
Published: April 2004

This article examines the effect of entrepreneurs’ social capital on investment decisions of venture capitalists. The empirical data is composed of 158 venture capital decisions in the People’s Republic of China. We found that entrepreneurs’ social capital has significant effects on investment selection decisions of venture capitalists in interaction with growth potential and technology/products of the venture. We also found that strong ties between entrepreneurs and venture capitalists have significant direct effects on investment process decisions such as contractual covenants, investment delivery, and venture valuation.
Chinese Organizations in Transition: Changing Promotion Patterns in the Reform Era
Authors: Zhao Wei , Zhou Xueguang
Published: April 2004

Since the 1980s, the People's Republic of China has embarked on a path of economic transformation that has led to profound changes in organizations. Based on work histories of a sample of urban residents drawn from 14 Chinese cities in six provinces, we assess the extent and direction of organizational transformation by analyzing changes in promotion patterns between the prereform era (1949–1979) and the reform era (1980–1994). We begin with Walder's dual-path model and examine distinctive mechanisms for promotion along two institutionalized—administrative and professional—career lines. We enrich Walder's model by considering the impact of macropolitical processes on career dynamics and the effect of emerging market mechanisms on different organizational sectors. Our findings show that there have been both continuity and significant changes in the criteria and opportunities of promotion in Chinese organizations across the two periods. In the reform era, more educated managers who were recently recruited into the organizations had the highest probability of being promoted. There were also significant variations in promotion patterns across career lines and organizational sectors, reflecting the impacts of both institutional persistence and emerging market forces.
Capital Structure in Transition: The Transformation of Financial Strategies in China's Emerging Economy
Authors: Keister Lisa A.
Published: April 2004

During economic transition, firms must dramatically reduce their financial dependence on the state and begin to borrow from nonstate capital sources. This paper draws on institutional and resource dependence theories to examine this fundamental transformation of firm capital structure during China's transition. I propose that managers borrowed from external sources even when internal funds were available because retained earnings were considered state assets. Firms used retained earnings to signal financial health but borrowed externally to reduce dependence on the state. Uncertainty during transformation produced interfirm imitation of borrowing strategies, particularly imitation of local and high status others. I argue that the dynamics of market development shaped firm borrowing strategies and that these strategies are best viewed as trajectories over time. Analysis of survey data on the 1980–1989 capital structure of formerly state-owned firms provides support for these arguments and highlights the importance of institutional context in understanding corporate borrowing and strategic decision making.
Comparison of Drug-Related Problems in Different Patient Groups
Authors: Viktil Kirsten K , Blix Hege S , Reikvam Aasmund , Moger Tron A , Hjemaas Bodil J , Walseth Elspeth K , Vraalsen Tine F , Pretsch Piia , Jorgensen Frank
Published: April 2004

BACKGROUND:

There is a lack of knowledge concerning how drug-related problems (DRPs) vary in different patient groups. Possible dissimilarities need to be taken into consideration when guidelines for detecting and preventing DRPs are compiled.

OBJECTIVE:

To characterize and compare the frequency and categories of DRPs in different groups of hospitalized patients.

METHODS:

Patients admitted to 4 different types of departments at 5 hospitals in Norway were included consecutively. Medical records and information acquired at multidisciplinary morning meetings were sources for assessing the patients' DRPs.

RESULTS:

A total of 827 patients were included. Mean age was 70.8 years, 58.6% were female, and 81% had at least one DRP. An average of 1.9, 2.0, 2.1, and 2.3 DRPs per patient were found in the departments of cardiology, geriatrics, respiratory medicine, and rheumatology, respectively. Significant differences in the type of DRPs between the patient groups were found. The most frequent DRPs and the patient group in which they most often occurred were nonoptimal dose (cardiology, respiratory, geriatric) and need for additional drug (rheumatology).

CONCLUSIONS:

DRPs occurred in the majority of the patients in all departments. The type of DRP differed markedly between the patient groups. Knowledge of these differences is clinically valuable by enabling us to guide efforts toward prevention of DRPs. Antithrombotic agents, loop diuretics, angiotensin-converting enzyme inhibitors, penicillins, antiinflammatory drugs, and opioid analgesics commonly caused DRPs, even in departments where knowledge of these drugs is assumed to be extensive.
Props, not pictures, are worth a thousand words: verbal accessibility of early memories under different conditions of contextual support
Authors: Bauer Patricia J. , van Abbema Dana L. , Wiebe Sandra A. , Cary Mari Strand , Phill Christina , Burch Melissa M.
Published: April 2004

When they are tested nonverbally, even young children demonstrate long‐term recall. There have been few studies of whether early memories later are verbally accessible; the results of those that exist are mixed. Inconsistencies may be due to differences in the contextual cues provided at the time of recall. In two experiments, children 13–20 months were exposed to multi‐step sequences and tested for nonverbal recall after 3–6 months. At age 3 years, they were tested verbally, under varying conditions of contextual support: in the original laboratory with event‐related props versus at home with photographs of the props (Experiment 1), and at home with props (Experiment 2). Children younger than 20 months at initial experience of the events did not demonstrate verbal recall. Children who were 20 months at the initial exposure recalled verbally, as long as they had physical props as cues, regardless of whether testing took place at home or in the laboratory. This research informs the conditions under which memories from very early childhood later can be recalled verbally. Copyright © 2004 John Wiley & Sons, Ltd.
What US judges know and believe about eyewitness testimony
Authors: Wise Richard A. , Safer Martin A.
Published: April 2004

In a survey, 160 US judges indicated their knowledge and beliefs about eyewitness testimony. Although correct on some issues, judges were often wrong on important issues such as whether at trial eyewitness confidence is a good indicator of eyewitness accuracy, and if jurors can distinguish accurate from inaccurate witnesses. Increased knowledge was associated with: a willingness to permit legal safeguards, including expert testimony at trial; a belief that jurors have limited knowledge of eyewitness factors; a reluctance to convict defendants solely from eyewitness testimony; a more accurate estimate of the extent to which wrongful convictions result from eyewitness error; and a belief that judges need more eyewitness training. Additional training about factors and procedures that affect eyewitness accuracy may help judges reduce the number of wrongful convictions. Copyright © 2004 John Wiley & Sons, Ltd.
Memory for common objects: brief intentional study is sufficient to overcome poor recall of US coin features
Authors: Marmie William R. , Healy Alice F.
Published: April 2004

Prior studies have explained the very poor recall for the features of a coin in terms of visual characteristics. Two experiments compared incidental exposure and intentional study of US coins on recall of their features. In Experiment 1, recall performance for a rarely seen Mercury dime after a 1‐min study period was better than that for an unstudied penny, even when the test on the dime was delayed 1 week. In Experiment 2, participants studied the dime for 15, 30, 45, or 60 s. Recall of the dime was greater than that of the unstudied penny even with the shortest study interval. Thus, a high level of recall of a coin's features can be obtained with brief intentional study, and that level can be maintained across a long delay interval. These findings suggest that poor retention of coin features is due to incidental exposure rather than to visual characteristics. Copyright © 2004 John Wiley & Sons, Ltd.
Fabrication deflation? The mixed effects of lying on memory
Authors: Polage Danielle C.
Published: April 2004

This study explored what happens when participants lie in order to convince others that false stories are true. Participants' memories were assessed by comparing their likelihood ratings for the events before and after lying about them. Results showed that most participants rated the events as less likely to have happened after lying about them. Therefore, the most common result of lying seems to be a strengthening of, not a distortion of, the truth. This decrease in likelihood rating for the statement lied about is termed ‘fabrication deflation’. In both studies, however, there were 10–16% of the participants who indicated maximum belief that the lie item was true. Whether this increase in likelihood rating for a lied about event is evidence of memory creation or the triggering of an actual memory is discussed. Copyright © 2004 John Wiley & Sons, Ltd.
Sequential processing in comprehension of hierarchical graphs
Authors: Körner Christof
Published: April 2004

Hierarchical graphs represent the relationships between non‐numerical entities or concepts (like computer file systems, family trees, etc). Graph nodes represent the concepts and interconnecting lines represent the relationships. We recorded participants' eye movements while viewing such graphs to test two possible models of graph comprehension. Graph readers had to answer interpretive questions, which required comparisons between two graph nodes. One model postulates a search and a combined search‐reasoning stage of graph comprehension (two‐stage model), whereas the second model predicts three stages, two stages devoted to the search of the relevant graph nodes and a separate reasoning stage. A detailed analysis of the eye movement data provided clear support for the three‐stage model. This is in line with recent studies, which suggest that participants serialize problem solving tasks in order to minimize the overall processing load. Copyright © 2004 John Wiley & Sons, Ltd.
A Simple, Efficient and General Procedure for Acetalization of Carbonyl Compounds and Deprotection of Acetals under the Catalysis of Indium(III) Chloride
Authors: Ranu Brindaban C. , Jana Ranjan , Samanta Sampak
Published: April 2004

Indium(III) chloride efficiently catalyzes the protection of a variety of aldehydes and ketones to their corresponding 1,3‐dioxolanes and dialkyl acetals in refluxing cyclohexane. On the other hand, deprotection of acetals is also achieved in refluxing aqueous methanol under the catalysis of indium(III) chloride.
Detailed Mechanistic Studies using in situ Spectroscopic Analysis: A Look at Little‐Known Regions of the Heck Reaction
Authors: Rothenberg Gadi , Cruz Susana C. , van Strijdonck Gino P. F. , Hoefsloot Huub C. J.
Published: April 2004

The mechanism of the Heck reaction using palladium complexes with large phosphoramidite ligands is investigated. The catalyst precursor is an inactive dimer that equilibrates with the active monomeric species. A series of kinetic models is introduced and compared with concentration profiles obtained from FT‐NIR spectroscopy. First, an analytical solution of the differential equations for a simplified mechanism is considered. This fits well at low conversions but deviates at higher conversions with increasing deactivation. Formation of palladium clusters and palladium black is then included, with the simplification that all the deactivation processes are represented by a single first‐order process. This results in a five‐step mechanism that describes the dimer‐monomer equilibrium, the Pd(II)/Pd(0) catalytic cycle, and the catalyst deactivation process. The model can be used to monitor the transient concentrations of the virtual Pd(0), Pd(II), and dimer catalyst species, and helps to explain the effects of water. The high resolution of the measurements and low error levels of the models render this approach a powerful tool for mechanistic studies in homogeneous catalysis.