bluuebunny/crossref_metadata_2025 huggingface dataset:
Motion planning for coating process optimisation in electron beam physical vapour deposition
Authors: Cho S. , Fuke I. , Prabhu V.
Published: September 2005

Electron beam physical vapour deposition (EB-PVD) is used mainly in a variety of coating and surface engineering applications. The present research focuses on coating process optimisation using EB-PVD for turbine blades, which are widely used in industrial, marine and aircraft applications. More specifically, the present research identifies the five most important objectives for the EB-PVD coating process and then proposes metrics to quantify such objectives. In addition, a heuristic for EFB-PVD process optimisation is developed to control workpiece motion systematically to reduce coating thickness variance, providing a uniform coating for turbine blades. The heuristic developed is an iterative algorithm which uses a finite element model of the rotating workpiece to determine the translation motion. The finite element model can be readily generated using standard computer aided design (CAD) of the workpiece, which makes the method applicable to workpieces with complex three-dimensional geometry. These computational developments are illustrated using a simulation of a turbine blade coating in which the coating thickness variance is reduced significantly. The proposed method could eliminate dedicated tooling/fixtures used in the traditional coating process and improve the cost effectiveness of the process, especially for low volume production.
Influence of mechanical surface treatments on fatigue property of 30CrMnSiNi2A steel
Authors: Gao Y. , Lu F. , Yao M.
Published: September 2005

The changes in surface integrity caused by surface treatments such as grinding, vibration polishing, vibration peening and shot peening were investigated, and their influence on the fatigue property of 30CrMnSiNi2A steel was studied. It was confirmed that the surface can be modified by vibration polishing, vibration peening and shot peening and that the fatigue endurance limit for 1 × 107 cycles of the vibration peened specimens is increased by 11%, and the corresponding limit of shot peened specimens is increased by 16% compared with the virgin ground specimens.
TiN–AlN nanomultilayer films for microdrilling and machining
Authors: Yao S. H. , Su Y. L. , Kao W. H. , Cheng K. W.
Published: September 2005

In this study, TiN–AlN nanomultilayer films were prepared using a new sputtering technique, which was designed and manufactured on the basis of a newly developed technology, i.e. high speed reactive plasma aided physical vapour deposition. This technique featured both an unbalanced magnetron sputtering system and a balanced magnetron sputtering system. The former was employed to deposit the AlN film, and the latter to deposit the TiN film. The aim of this study was primarily to obtain, through controlled deposition conditions, a group of TiN–AlN nanomultilayer films and then to investigate the influence of various sequences on their fundamental properties and wear behaviour. Finally, two sets of field tests, microdrilling and machining, were conducted in order to determine the feasibility of applying the multilayers in production machining situations. The results revealed that, via control of the deposition parameters, TiN–AlN nanomultilayer films ranging from 2·4 to 67·6 nm could be obtained. At a periodicity of ≥3·6 nm, the multilayers had extremely high hardness, and excellent adhesion and wear performance. Field testing confirmed that the nanomultilayers could provide very significant improvement in actual machining performance, as compared with the traditional single layer TiN films.
Microstructure and microhardness of gas nitrided surface layers in Ti–8Al–1Mo–1V and Ti–10V–2Fe–3Al alloys
Authors: Zhecheva A. , Malinov S. , Sha W.
Published: September 2005

Two different types of titanium alloy, near α Ti–8Al–1Mo–1V and near β Ti–10V–2Fe–3Al, were studied in this work. They were thermochemically treated in a pure nitrogen atmosphere in order to improve their surface properties. The nitriding was performed at two different temperatures, 950°C and 1050°C, and for three different periods of time, 1, 3 and 5 h. Nitrided layers were formed during the process with a thickness from 100 to 350 μm, depending on the processing temperature and time, for both alloys. Their microstructural characteristics and phase composition were studied using optical microscopy and X-ray diffraction. X-ray analyses indicated that new phases α-Ti(N), TiN and TiO2 were formed during the process of nitriding. The lattice parameters a and c of the α phase and residual surface stress were obtained. The surface hardness was measured for all the samples. Microhardness profiles were obtained on cross-sections of the samples by applying a Knoop indenter. The surface hardness increases with increases in the temperature and duration of nitriding. The maximum values of the microhardness (HK0·05) varied between 550 and 820 for Ti–8Al–1Mo–1V. For Ti–10V–2Fe–3Al, they varied between 520 and 870.
Incomplete quality of life data in lung transplant research: comparing cross sectional, repeated measures ANOVA, and multi-level analysis
Authors: Vermeulen Karin M , Post Wendy J , Span Mark M , van der Bij Wim , Koëter Gerard H , TenVergert Elisabeth M
Published: September 2005

Background

In longitudinal studies on Health Related Quality of Life (HRQL) it frequently occurs that patients have one or more missing forms, which may cause bias, and reduce the sample size. Aims of the present study were to address the problem of missing data in the field of lung transplantation (LgTX) and HRQL, to compare results obtained with different methods of analysis, and to show the value of each type of statistical method used to summarize data.

Methods

Results from cross-sectional analysis, repeated measures on complete cases (ANOVA), and a multi-level analysis were compared. The scores on the dimension 'energy' of the Nottingham Health Profile (NHP) after transplantation were used to illustrate the differences between methods.

Results

Compared to repeated measures ANOVA, the cross-sectional and multi-level analysis included more patients, and allowed for a longer period of follow-up. In contrast to the cross sectional analyses, in the complete case analysis, and the multi-level analysis, the correlation between different time points was taken into account. Patterns over time of the three methods were comparable. In general, results from repeated measures ANOVA showed the most favorable energy scores, and results from the multi-level analysis the least favorable. Due to the separate subgroups per time point in the cross-sectional analysis, and the relatively small number of patients in the repeated measures ANOVA, inclusion of predictors was only possible in the multi-level analysis.

Conclusion

Results obtained with the various methods of analysis differed, indicating some reduction of bias took place. Multi-level analysis is a useful approach to study changes over time in a data set where missing data, to reduce bias, make efficient use of available data, and to include predictors, in studies concerning the effects of LgTX on HRQL.
GASH: An improved algorithm for maximizing the number of equivalent residues between two protein structures
Authors: Standley Daron M , Toh Hiroyuki , Nakamura Haruki
Published: September 2005

Background

We introduce GASH, a new, publicly accessible program for structural alignment and superposition. Alignments are scored by the Number of Equivalent Residues (NER), a quantitative measure of structural similarity that can be applied to any structural alignment method. Multiple alignments are optimized by conjugate gradient maximization of the NER score within the genetic algorithm framework. Initial alignments are generated by the program Local ASH, and can be supplemented by alignments from any other program.

Results

We compare GASH to DaliLite, CE, and to our earlier program Global ASH on a difficult test set consisting of 3,102 structure pairs, as well as a smaller set derived from the Fischer-Eisenberg set. The extent of alignment crossover, as well as the completeness of the initial set of alignments are examined. The quality of the superpositions is evaluated both by NER and by the number of aligned residues under three different RMSD cutoffs (2,4, and 6Å). In addition to the numerical assessment, the alignments for several biologically related structural pairs are discussed in detail.

Conclusion

Regardless of which criteria is used to judge the superposition accuracy, GASH achieves the best overall performance, followed by DaliLite, Global ASH, and CE. In terms of CPU usage, DaliLite CE and GASH perform similarly for query proteins under 500 residues, but for larger proteins DaliLite is faster than GASH or CE. Both an http interface and a simple object application protocol (SOAP) interface to the GASH program are available at http://www.pdbj.org/GASH/.
Identification and characterization of the fibrinogen-like domain of fibrinogen-related proteins in the mosquito, Anopheles gambiae, and the fruitfly, Drosophila melanogaster, genomes
Authors: Wang Xinguo , Zhao Qin , Christensen Bruce M
Published: September 2005

Background

The fibrinogen-like (FBG) domain, which consists of approximately 200 amino acid residues, has high sequence similarity to the C-terminal halves of fibrinogen β and γ chains. Fibrinogen-related proteins (FREPs), which contain FBG domains in their C-terminal region, are found universally in vertebrates and invertebrates. In invertebrates, FREPs are involved in immune responses and other aspects of physiology. To understand the complexity of this family in insects, we analyzed FREPs in the mosquito genome and made comparisons to FREPs in the fruitfly genome.

Results

By using the genome data of the mosquito, Anopheles gambiae, 53 FREPs were identified, whereas only 20 members were found in the Drosophila melanogaster genome. Using sequence profile analysis, we found that FBG domains have high sequence similarity and are highly conserved throughout the FBG domain region. By secondary structure analysis and comparison, the FBG domains of FREPs are predicted to function in recognition of carbohydrates and their derivatives on the surface of microorganisms in innate immunity.

Conclusion

Detailed sequence and structural analysis discloses that the FREP family contains FBG domains that have high sequence similarity in the A. gambiae genome. Expansion of the FREP family in mosquitoes during evolutionary history is mainly accounted for by a major expansion of the FBG domain architecture. The characterization of the FBG domains in the FREP family is likely to aid in the experimental analysis of the ability of mosquitoes to recognize parasites in innate immunity and physiologies associated with blood feeding.
Microarray analysis of Pseudomonas aeruginosa reveals induction of pyocin genes in response to hydrogen peroxide
Authors: Chang Wook , Small David A , Toghrol Freshteh , Bentley William E
Published: September 2005

Background

Pseudomonas aeruginosa, a pathogen infecting those with cystic fibrosis, encounters toxicity from phagocyte-derived reactive oxidants including hydrogen peroxide during active infection. P. aeruginosa responds with adaptive and protective strategies against these toxic species to effectively infect humans. Despite advances in our understanding of the responses to oxidative stress in many specific cases, the connectivity between targeted protective genes and the rest of cell metabolism remains obscure.

Results

Herein, we performed a genome-wide transcriptome analysis of the cellular responses to hydrogen peroxide in order to determine a more complete picture of how oxidative stress-induced genes are related and regulated.

Our data reinforce the previous conclusion that DNA repair proteins and catalases may be among the most vital antioxidant defense systems of P. aeruginosa. Our results also suggest that sublethal oxidative damage reduces active and/or facilitated transport and that intracellular iron might be a key factor for a relationship between oxidative stress and iron regulation. Perhaps most intriguingly, we revealed that the transcription of all F-, R-, and S-type pyocins was upregulated by oxidative stress and at the same time, a cell immunity protein (pyocin S2 immunity protein) was downregulated, possibly leading to self-killing activity.

Conclusion

This finding proposes that pyocin production might be another novel defensive scheme against oxidative attack by host cells.
The "lipid accumulation product" performs better than the body mass index for recognizing cardiovascular risk: a population-based comparison
Authors: Kahn Henry S
Published: September 2005

Background

Body mass index (BMI, kg/m2) may not be the best marker for estimating the risk of obesity-related disease. Consistent with physiologic observations, an alternative index uses waist circumference (WC) and fasting triglycerides (TG) concentration to describe lipid overaccumulation.

Methods

The WC (estimated population minimum 65 cm for men and 58 cm for women) and TG concentration from the third National Health and Nutrition Examination Survey (N = 9,180, statistically weighted to represent 100.05 million US adults) were used to compute a "lipid accumulation product" [LAP = (WC-65) × TG for men and (WC-58) × TG for women] and to describe the population distribution of LAP. LAP and BMI were compared as categorical variables and as log-transformed continuous variables for their ability to identify adverse levels of 11 cardiovascular risk factors.

Results

Nearly half of the represented population was discordant for their quartile assignments to LAP and BMI. When 23.54 million with ordinal LAP quartile > BMI quartile were compared with 25.36 million with ordinal BMI quartile > LAP quartile (regression models adjusted for race-ethnicity and sex) the former had more adverse risk levels than the latter (p < 0.002) for seven lipid variables, uric acid concentration, heart rate, systolic and diastolic blood pressure. Further adjustment for age did not materially alter these comparisons except for blood pressures (p > 0.1). As continuous variables, LAP provided a consistently more adverse beta coefficient (slope) than BMI for nine cardiovascular risk variables (p < 0.01), but not for blood pressures (p > 0.2).

Conclusion

LAP (describing lipid overaccumulation) performed better than BMI (describing weight overaccumulation) for identifying US adults at cardiovascular risk. Compared to BMI, LAP might better predict the incidence of cardiovascular disease, but this hypothesis needs prospective testing.
Design and pilot results of a single blind randomized controlled trial of systematic demand-led home visits by nurses to frail elderly persons in primary care [ISRCTN05358495]
Authors: van Hout Hein PJ , Nijpels Giel , van Marwijk Harm WJ , Jansen Aaltje PD , van't Veer Petronella J , Tybout Willemijn , Stalman Wim AB
Published: September 2005

Background

The objective of this article is to describe the design of an evaluation of the cost-effectiveness of systematic home visits by nurses to frail elderly primary care patients. Pilot objectives were: 1. To determine the feasibility of postal multidimensional frailty screening instruments; 2. to identify the need for home visits to elderly.

Methods

Main study: The main study concerns a randomized controlled in primary care practices (PCP) with 18 months follow-up and blinded PCPs. Frail persons aged 75 years or older and living at home but neither terminally ill nor demented from 33 PCPs were eligible. Trained community nurses (1) visit patients at home and assess the care needs with the Resident Assessment Instrument-Home Care, a multidimensional computerized geriatric assessment instrument, enabling direct identification of problem areas; (2) determine the care priorities together with the patient; (3) design and execute interventions according to protocols; (4) and visit patients at least five times during a year in order to execute and monitor the care-plan. Controls receive usual care. Outcome measures are Quality of life, and Quality Adjusted Life Years; time to nursing home admission; mortality; hospital admissions; health care utilization.

Pilot 1: Three brief postal multidimensional screening measures to identify frail health among elderly persons were tested on percentage complete item response (selected after a literature search): 1) Vulnerable Elders Screen, 2) Strawbridge's frailty screen, and 3) COOP-WONCA charts.

Pilot 2: Three nurses visited elderly frail patients as identified by PCPs in a health center of 5400 patients and used an assessment protocol to identify psychosocial and medical problems. The needs and experiences of all participants were gathered by semi-structured interviews.

Discussion

The design holds several unique elements such as early identification of frail persons combined with case-management by nurses.

From two pilots we learned that of three potential postal frailty measures, the COOP-WONCA charts were completed best by elderly and that preventive home visits by nurses were positively evaluated to have potential for quality of care improvement.
Differences in tidal breathing between infants with chronic lung diseases and healthy controls
Authors: Schmalisch G , Wilitzki S , Wauer RR
Published: September 2005

Background

The diagnostic value of tidal breathing (TB) measurements in infants is controversially discussed. The aim of this study was to investigate to what extent the breathing pattern of sleeping infants with chronic lung diseases (CLD) differ from healthy controls with the same postconceptional age and to assess the predictive value of TB parameters.

Methods

In the age of 36–42 postconceptional weeks TB measurements were performed in 48 healthy newborns (median age and weight 7d, 3100 g) and 48 infants with CLD (80d, 2465 g)) using the deadspace-free flow-through technique. Once the infants had adapted to the mask and were sleeping quietly and breathing regularly, 20–60 breathing cycles were evaluated. Beside the shape of the tidal breathing flow-volume loop (TBFVL) 18 TB parameters were analyzed using ANOVA with Bonferroni correction. Receiver-operator characteristic (ROC) curves were calculated to investigate the discriminative ability of TB parameters.

Results

The incidence of concave expiratory limbs in CLD infants was 31% and significantly higher compared to controls (2%) (p < 0.001). Significant differences between CLD infants and controls were found in 11/18 TB parameters. The largest differences were seen in the mean (SD) inspiratory time 0.45(0.11)s vs. 0.65(0.14)s (p < 0.0001) and respiratory rate (RR) 55.4(14.2)/min vs. 39.2(8.6)/min (p < 0.0001) without statistically significant difference in the discriminative power between both time parameters. Most flow parameters were strongly correlated with RR so that there is no additional diagnostic value. No significant differences were found in the tidal volume and commonly used TB parameters describing the expiratory flow profile.

Conclusion

The breathing pattern of CLD infants differs significantly from that of healthy controls. Concave TBFVL and an increased RR measured during quiet sleep and under standardized conditions may indicate diminished respiratory functions in CLD infants whereas most of the commonly used TB parameters are poorly predictive.
Variation in the psychosocial determinants of the intention to prescribe hormone therapy prior to the release of the Women's Health Initiative trial: a survey of general practitioners and gynaecologists in France and Quebec
Authors: Legare France , Godin Gaston , Ringa Virginie , Dodin Sylvie , Turcot Lucile , Norton Joanna
Published: September 2005

Background

Theory-based approaches are advocated to improve our understanding of prescription behaviour. This study is an application of the theory of planned behaviour (TPB) with additional variables. It was designed to assess which variables were associated with the intention to prescribe hormone therapy (HT). In addition, variations in the measures across medical specialities (GPs and gynaecologists) and across countries (France and Quebec) were investigated.

Methods

A survey among 2,000 doctors from France and 1,044 doctors from Quebec was conducted. Data were collected by means of a self-administered questionnaire. A clinical vignette was used to elicit doctors' opinions. The following TPB variables were assessed: attitude, subjective norm, perceived behavioural control, attitudinal beliefs, normative beliefs and power of control beliefs. Additional variables (role belief, moral norm and practice pattern-related factors) were also assessed. A stepwise logistic regression was used to assess which variables were associated with the intention to prescribe HT. GPs and gynaecologists were compared to each other within countries and the two countries were compared within the specialties.

Results

Overall, 1,085 doctors from France returned their questionnaire and 516 doctors from Quebec (response rate = 54% and 49%, respectively). In the overall regression model, power of control beliefs, moral norm and role belief were significantly associated with intention (all at p < 0.0001). The models by specialty and country were: for GPs in Quebec, power of control beliefs (p < 0.0001), moral norm (p < 0.01) and cytology and hormonal dosage (both at p < 0.05); for GPs in France, power of control beliefs and role belief (both at p < 0.0001) and perception of behavioural control (p < 0.05) and cessation of menses (p < 0.01); for gynaecologists in Quebec, moral norm and power of control beliefs (both at p = 0.01); and for gynaecologists in France, power of control beliefs (p < 0.0001), and moral norm, role belief and lipid profile (all at p < 0.05).

Conclusion

In both countries, compared with GPs, intention to prescribe HT was higher for gynaecologists. Psychosocial determinants of doctors' intention to prescribe HT varied according to the specialty and the country thus, suggesting an influence of contextual factors on these determinants.
Serum butyrylcholinesterase in type 2 diabetes mellitus: a biochemical and bioinformatics approach
Authors: Sridhar GR , Nirmala G , Apparao Allam , Madhavi AS , Sreelatha S , Rani J Sudha , Vijayalakshmi P
Published: September 2005

Background

Butyrylcholinesterase is an enzyme that may serve as a marker of metabolic syndrome. We (a) measured its level in persons with diabetes mellitus, (b) constructed a family tree of the enzyme using nucleotide sequences downloaded from NCBI. Butyrylcholinesterase was estimated colorimetrically using a commercially available kit (Randox Lab, UK). Phylogenetic trees were constructed by distance method (Fitch and Margoliash method) and by maximum parsimony method.

Results

There was a negative correlation between serum total cholesterol and butyrylcholinesterase (-0.407; p < 0.05) and between serum LDL cholesterol and butyrylcholinesterase (-0.435; p < 0.05). There was no statistically significant correlation among the other biochemical parameters. In the evolutionary tree construction both methods gave similar trees, except for an inversion in the position of Sus scrofa (M62778) and Oryctolagus cuniculus (M62779) between Fitch and Margoliash, and maximum parsimony methods.

Conclusion

The level of butyrylcholinesterase enzyme was inversely related to serum cholesterol; dendrogram showed that the structures from evolutionarily close species were placed near each other.
Fostering critical thinking skills: a strategy for enhancing evidence based wellness care
Authors: Jamison Jennifer R
Published: September 2005

Chiropractic has traditionally regarded itself a wellness profession. As wellness care is postulated to play a central role in the future growth of chiropractic, the development of a wellness ethos acceptable within conventional health care is desirable.

This paper describes a unit which prepares chiropractic students for the role of "wellness coaches". Emphasis is placed on providing students with exercises in critical thinking in an effort to prepare them for the challenge of interfacing with an increasingly evidence based health care system.

Methods

This case study describes how health may be promoted and disease prevented through development of personalized wellness programs. As critical thinking is essential to the provision of evidence based wellness care, diverse learning opportunities for developing and refining critical thinking skills have been created. Three of the learning opportunities are an intrinsic component of the subject and, taken together, contributed over 50% of the final grade of the unit. They include a literature review, developing a client wellness contract and peer evaluation. In addition to these 3 compulsory exercises, students were also given an opportunity to develop their critical appraisal skills by undertaking voluntary self- and unit evaluation. Several opportunities for informal self-appraisal were offered in a structured self-study guide, while unit appraisal was undertaken by means of a questionnaire and group discussion at which the Head of School was present.

Results

Formal assessment showed all students capable of preparing a wellness program consistent with current thinking in contemporary health care. The small group of students who appraised the unit seemed to value the diversity of learning experiences provided. Opportunities for voluntary unit and self-appraisal were used to varying degrees.

Unit evaluation provided useful feedback that led to substantial changes in unit structure.

Conclusion

Students have demonstrated themselves capable of applying critical thinking in construction of evidence based wellness programs. With respect to unit design, selective use of learning opportunities highlighted the desirability of using obligatory learning opportunities to ensure exposure to core constructs while student feedback was found to provide useful information for enriching unit review.

It is hoped inclusion of critical thinking learning opportunities in the undergraduate chiropractic curriculum will contribute to the development of an evidence based ethos in chiropractic care.
Elimination of rheumatoid synovium in situusing a Fas ligand 'gene scalpel'
Authors: Zhang Haidi , Gao Guangping , Clayburne Gilda , Schumacher H Ralph
Published: September 2005

Surgical synovectomy to remove the inflammatory synovium can temporarily ameliorate rheumatoid inflammation and delay the progress of joint destruction. An efficient medically induced programmed cell death (apoptosis) in the rheumatoid synovium might play a role similar to synovectomy but without surgical tissue damage. Gene transfer of Fas ligand (FasL) has increased the frequency of apoptotic cells in mouse and rabbit arthritic synovium. In this study, we investigated whether repeated FasL gene transfer could remove human inflammatory synovial tissue in situ and function as a molecular synovectomy. Briefly, specimens of human synovium from joint replacement surgeries and synovectomies of rheumatoid arthritis (RA) patients were grafted subcutaneously into male C.B-17 severe combined immunodeficiency (SCID) mice. Injections of a recombinant FasL adenovirus (Ad-FasL) into the grafted synovial tissue at the dosage of 1011 particles per mouse were performed every two weeks. Three days after the fifth virus injection, the mice were euthanized by CO2 inhalation and the human synovial tissues were collected, weighed and further examined. Compared to the control adenovirus-LacZ (Ad-LacZ) and phosphate buffered saline (PBS) injected RA synovium, the Ad-FasL injected RA synovium was dramatically reduced in size and weight (P < 0.005). The number of both synoviocytes & mononuclear cells was significantly reduced. Interestingly, an approximate 15-fold increased frequency of apoptotic cells was observed in RA synovium three days after Ad-FasL injection, compared with control tissues. In summary, our in vivo investigation of gene transfer to human synovium in SCID mice suggests that repeated intra-articular gene transfer of an apoptosis inducer, such as FasL, may function as a 'gene scalpel' for molecular synovectomy to arrest inflammatory synovium at an early stage of RA.
Raloxifene reduces urokinase-type plasminogen activator-dependent proliferation of synoviocytes from patients with rheumatoid arthritis
Authors: Guiducci S , Del Rosso A , Cinelli M , Perfetto F , Livi R , Rossi A , Gabrielli A , Giacomelli R , Iori N , Fibbi G , Del Rosso M , Cerinic M Matucci
Published: September 2005

Extracellular fibrinolysis, controlled by the membrane-bound fibrinolytic system, is involved in cartilage damage and rheumatoid arthritis (RA) synovitis. Estrogen status and metabolism seem to be impaired in RA, and synoviocytes show receptors for estrogens. Our aims in this study were to evaluate in healthy and RA synoviocytes the effects of Raloxifene (RAL), a selective estrogen receptor modulator (SERM), on: proliferation; the components of the fibrinolytic system; and chemoinvasion. The effects of RAL were studied in vitro on synoviocytes from four RA patients and four controls. Proliferation was evaluated as cell number increase, and synoviocytes were treated with 0.5 μM and 1 μM RAL with and without urokinase-plasminogen activator (u-PA) and anti-u-PA/anti-u-PA receptor (u-PAR) antibodies. Fibrinolytic system components (u-PA, u-PAR and plasminogen activator inhibitor (PAI)-1) were assayed by ELISA with cells treated with 0.5 μM and 1 μM RAL for 48 h. u-PA activity was evaluated by zymography and a direct fibrinolytic assay. U-PAR/cell and its saturation were studied by radioiodination of u-PA and a u-PA binding assay. Chemoinvasion was measured using the Boyden chamber invasion assay. u-PA induced proliferation of RA synoviocytes was blocked by RAL (p < 0.05) and antagonized by antibodies alone. The inhibitory effect of RAL was not additive with u-PA/u-PAR antagonism. RA synoviocytes treated with RAL showed, compared to basal, higher levels of PAI-1 (10.75 ± 0.26 versus 5.5 ± 0.1 μg/106 cells, respectively; p < 0.01), lower levels of u-PA (1.04 ± 0.05 versus 3.1 ± 0.4 ng/106 cells, respectively; p < 0.001), and lower levels of u-PAR (11.28 ± 0.22 versus 23.6 ± 0.1 ng/106 cells, respectively; p < 0.001). RAL also significantly inhibited u-PA-induced migration. Similar effects were also shown, at least partially, in controls. RAL exerts anti-proliferative and anti-invasive effects on synoviocytes, mainly modulating u-PAR and, to a lesser extent, u-PA and PAI-1 levels, and inhibiting cell migration and proliferation.
Polymorphism in the tumour necrosis factor receptor II gene is associated with circulating levels of soluble tumour necrosis factor receptors in rheumatoid arthritis
Authors: Glossop John R , Dawes Peter T , Nixon Nicola B , Mattey Derek L
Published: September 2005

Levels of soluble tumour necrosis factor receptors (sTNFRs) are elevated in the circulation of patients with rheumatoid arthritis (RA). Although these receptors can act as natural inhibitors of tumour necrosis factor-α, levels of sTNFRs in RA appear to be insufficient to prevent tumour necrosis factor-α induced inflammation. The factors that regulate circulating levels of sTNFRs are unclear, but polymorphisms in the tumour necrosis factor receptor genes may play a role. We investigated the relationship between polymorphisms in the tumour necrosis factor receptor I (TNF-RI) and II (TNF-RII) genes and levels of sTNFRs in two groups of Caucasian RA patients: one with early (disease duration ≤2 years; n = 103) and one with established disease (disease duration ≥5 years; n = 151). PCR restriction fragment length polymorphism analysis was used to genotype patients for the A36G polymorphism in the TNF-RI gene and the T676G polymorphism in TNF-RII. Levels of sTNFRs were measured using ELISA. We also isolated T cells from peripheral blood of 58 patients with established RA with known TNF-R genotypes, and release of sTNFRs into the culture medium was measured in cells incubated with or without phytohaemagglutinin. Serum levels of the two sTNFRs (sTNF-RI and sTNF-RII) were positively correlated in both populations, and the level of each sTNFR was significantly higher in the patients with established disease (P < 0.0001). Multiple regression analyses corrected for age, sex and disease duration revealed a significant trend toward decreasing sTNF-RI and sTNF-RII levels across the TNF-RII genotypes (TT > TG > GG) of patients with established disease (P for trend = 0.01 and P for trend = 0.03, respectively). A similar nonsignificant trend was seen for early disease. No relationship with the TNF-RI A36G polymorphism was observed. sTNFRs released by isolated T cells exhibited a similar trend toward decreasing levels according to TNF-RII genotype, although only the association with levels of sTNF-RII was significant. Strong correlations were found between levels of circulating sTNFRs and levels released by T cells in vitro. Our data indicate that the T676G polymorphism in TNF-RII is associated with levels of sTNFRs released from peripheral blood T cells, and with circulating levels of sTNFR in patients with RA.
The effect of test-taker gender, audience and topic on task performance in tape-mediated assessment of speaking
Authors: Lumley Tom , O’Sullivan Barry
Published: September 2005

Performance in tests of spoken language can be influenced by a wide range of features of both task and participants. This article hypothesizes that there may be effects on performance attributable to an interaction of variables such as the task topic, the gender of the person presenting the topic and the gender of the candidate. In contrast to previous studies, which have examined speaking tests involving face-to-face interaction, this study considered the issue in a tape-mediated test delivered in a language laboratory, with no inter-locutor present, but where stimulus material is presented by one or more speakers, one of whom acts as ‘audience’ for the candidate’s speech. The test was taken by 894 students graduating from Hong Kong universities. In an advice-giving task, the last of a series involving different situations and audiences, topics considered stereotypically ‘male’-oriented or ‘female’-oriented were presented with systematic changes in the roles taken by the male and female speakers. A multi-faceted Rasch analysis examined the interaction of test-taker gender, task topic, and gender of presenter/audience. The results showed small effects for some, but not all, of the hypothesized interactions. Examples of differential performance by male and female candidates on other tasks are also presented. The article concludes with discussion of the implications for task design and test content.
Examining the predictive validity of a screening test for court interpreters
Authors: Stansfield Charles W. , Hewitt William E.
Published: September 2005

The United States Court Interpreters Act (US Congress, 1978) requires that interpreters in US federal courts be certified through a criterion-referenced performance test. The Federal Court Interpreter Certification Examination (FCICE) is a two-phase certification battery for federal court interpreters. Phase I is a multiple-choice Written Examination (WE) used to screen candidates for eligibility to take the Phase II criterion-referenced Oral Examination (OE). This study evaluates the predictive validity of the WE in relationship to examinee performance on the OE, using an experimental sample of examinees who took the tests concurrently. Results indicate that the WE correlates appropriately with performance on the OE (.648 and .676 for the English and Spanish subtests respectively). Nearly all of those who failed the WE also failed the OE, although several false negatives were identified. However, when the data were reanalysed using a lower cut score for the Phase I WE, nearly all false negatives were eliminated. A follow-up study replicated the findings with a different sample. The authors discuss the advantages and disadvantages of lowering the passing score on the screening test in light of their findings. The study and subsequent discussion provide an example of how an established passing score can be reconsidered and modified.
Do visual chunks and planning impact performance on the graph description task in the SPEAK exam?
Authors: Xi Xiaoming
Published: September 2005

This study examines how task characteristics (the number of visual chunks and the amount of planning time) and test-taker characteristics (graph familiarity) influence the perceptual and cognitive processes involved in graph comprehension, the strategies used in describing graphs, and the scores obtained on the graph description task in a semi-direct oral test. Specifically, it investigates whether providing planning time and reducing the number of visual chunks in bar and line graphs help mitigate the influence of graph familiarity on language performance on graph description tasks. These research questions were explored using a structural equation modeling approach in a framework of the influence of the interaction between task characteristics and test-taker characteristics on task performance. It was found that graph familiarity affected the overall communicative quality of participants’ performance on these graph description tasks. Graph familiarity thus represented a potential source of construct-irrelevant variance. However, reducing the number of visual chunks in a graph and providing planning time positively impacted the perceptual and cognitive processes involved in graph comprehension and helped mitigate the influence of graph familiarity. Practical and theoretical implications of this study are discussed.
Determinants of serum lipoprotein(a) concentration in normolipidaemic individuals without clinical atherosclerosis
Authors: Dalpino F , Sodré FL , Castilho LN , de Faria EC
Published: September 2005

Background: Lipoprotein(a) (Lp(a)) is an independent risk factor for coronary artery diseases. The main objective of this work was to evaluate the determinants of plasma Lp(a) concentrations in normolipidaemic individuals.

Methods: Immunonephelometric quantification of Lp(a) was made in 177 volunteers. A multivariate analysis was employed to verify the influence of clinical and biochemical parameters on plasma Lp(a) concentration.

Results: The serum Lp(a) concentration in this population ranged from 0.7 to 40 nmol/L. The Lp(a) predictors were: sex (female), HDL2 triglyceride (negative) and LDL-cholesterol (positive).

Conclusions: The modulation of plasma Lp(a) concentration in this study points to pro-atherogenic lipoprotein associations.
Impact of haemodialysis on individual endogenous plasma acylcarnitine concentrations in end-stage renal disease
Authors: Reuter Stephanie E , Evans Allan M , Faull Randall J , Chace Donald H , Fornasini Gianfranco
Published: September 2005

Background: Patients with end-stage renal disease (ESRD) undergoing long-term haemodialysis exhibit low L-carnitine and elevated acylcarnitine concentrations. This study evaluated endogenous concentrations of an array of acylcarnitines (carbon chain length up to 18) in healthy individuals and ESRD patients receiving haemodialysis, and examined the impact of a single haemodialysis session on acylcarnitine concentrations.

Methods: Blood samples were collected from 60 healthy subjects and 50 ESRD patients undergoing haemodialysis (pre- and post-dialysis samples). Plasma samples were analysed for individual acylcarnitine concentrations by electrospray MS/MS.

Results: Of the 31 acylcarnitines, 29 were significantly ( P<0.05) elevated in ESRD patients compared with healthy controls; in particular, C5 and C8:1 concentrations were substantially elevated. For acylcarnitines with a carbon chain length less than eight, plasma acylcarnitine concentrations decreased significantly over the course of a single dialysis session; however, post-dialysis concentrations invariably remained significantly higher than those in healthy subjects. Dialytic removal of acylcarnitines diminished once the acyl chain length exceeded eight carbons.

Conclusions: The accumulation of acylcarnitines during long-term haemodialysis suggests that removal by haemodialysis is less efficient than removal from the body by the healthy kidney. Removal is significantly correlated to acyl chain length, most likely due to the increased molecular weight and lipophilicity that accompanies increased chain length.
Measurement of citrate in urine using liquid chromatography tandem mass spectrometry: comparison with an enzymatic method
Authors: Keevil BG , Owen L , Thornton S , Kavanagh J
Published: September 2005

Background: Measurement of urine citrate is used to assess the risk of further urinary stone formation and to assess the benefit of treatment in affected individuals. We wanted to develop a simple and rapid liquid chromatography tandem mass spectrometry (LC-MS/MS) method for the analysis of urinary citrate and to compare it with our current enzymatic assay.

Methods: For the LC-MS/MS assay, samples were prepared in a deep-well block by adding 10 µL of urine and 20 µL of internal standard to 400 µL of water. After mixing, 3 µL of the diluted sample was injected into the LC-MS/MS system. An LC system was used to isocratically elute a C18 column (50 x 2.1 mm) with 0.4 mL/min water containing 2 mmol/L ammonium acetate and 0.1% (v/v) formic acid. A step gradient of 100% methanol containing 2 mmol/L ammonium acetate and 0.1% (v/v) formic acid was used to wash the column. The retention times were 1.4 min for citrate and 1.4 min for d4-citrate. Cycle time was 4.0 min, injection to injection. The analytes were monitored using a tandem mass spectrometer operated in multiple reaction monitoring mode using the following transitions, citrate m/ z 191.0> 111.0 and d4-citrate m/ z 195.0> 113.0.

Results: Within and between-batch coefficients of variation were <3% over the range 480-3800 µmol/L. The lower limit of quantification was 24.0 µmol/L. Regression analysis showed LC-MS/MS = 0.8781 (enzymatic assay) + 102.5, r = 0.964, n = 73.

Conclusions: We have developed a simple LC-MS/MS method for urinary citrate measurement that shows acceptable performance.
Determinants of serum copper, zinc and selenium in healthy subjects
Authors: Ghayour-Mobarhan M , Taylor A , New SA , Lamb DJ , Ferns GAA
Published: September 2005

Background: We have investigated the association between serum copper, zinc and selenium concentrations, dietary intake, and demographic characteristics, including individual coronary risk factors, in healthy subjects.

Methods: Serum copper, zinc and selenium were measured by atomic absorption spectrometry in 189 healthy subjects. Serum glutathione peroxidase and caeruloplasmin were also determined for each subject. A previously validated food frequency questionnaire was used to estimate the dietary trace element intake.

Results: Male subjects had significantly lower serum copper ( P<0.001) and caeruloplasmin ( P<0.001), and higher serum zinc ( P<0.05) and zinc:copper ratio ( P<0.001) than female subjects. Significant differences were observed in serum copper and caeruloplasmin concentrations ( P<0.01) with age. Weak but significant associations between dietary trace elements and their serum concentrations were observed for zinc ( r=0.18, P=0.02), copper ( r=0.17, P=0.03) and selenium ( r=0.19, P=0.02). Obese subjects had significantly lower serum concentrations of zinc ( P<0.05). In multifactorial analysis, dietary zinc ( P<0.05), serum high-density lipoprotein-cholesterol (HDL-C) ( P<0.05), diastolic blood pressure ( P<0.05) and age ( P=0.05) emerged as major predictors of serum zinc concentrations. The corresponding predictors for serum copper were C-reactive protein (CRP) ( P<0.001), serum HDL-C ( P<0.001), gender ( P=0.01), physical activity levels ( P<0.05) and dietary copper ( P<0.05). Serum selenium concentrations were predicted by serum total cholesterol ( P<0.01), serum CRP concentrations ( P<0.05) and dietary selenium ( P<0.03).

Conclusion: Serum copper, zinc and selenium concentrations are influenced by physiological conditions such as age, diet and gender. Their serum concentrations are also associated with coronary risk factors, including body mass index, levels of physical activity, serum HDL-C and CRP.
The sweat test: effect of elution time on chloride and sodium concentrations
Authors: Gilbert Christopher J , Griffiths Melanie J , Holland Martin R , Gama Rousseau
Published: September 2005

Background: The National Committee for Clinical Laboratory Standards guidelines and Guidelines for the Performance of the Sweat Test for the Diagnosis of Cystic Fibrosis in the United Kingdom recommend that sweat be eluted from filter paper for a minimum of 40 min. In the absence of published data, this recommendation is based on expert opinion. We therefore investigated the effect of elution time on chloride and sodium concentrations.

Methods: The effect of elution time (up to three hours) on chloride and sodium concentrations was studied as recommended for measurement of quality control samples using external quality assessment solutions.

Results: There were no significant differences in eluted chloride and sodium concentrations with time of elution up to 3 h.

Conclusion: Elution time within 3 h had no effect on chloride and sodium concentrations when eluted from filter paper.
The glucose response to an oral fat tolerance test in young men with a paternal history of premature myocardial infarction: possible early indication of insulin resistance. The EARS 2 study
Authors: Murphy MJ , Nicaud V , Martin BC , O'Reilly DStJ ,   European Atherosclerosis Research Study (EARS) Group
Published: September 2005

Background: Concentrations of cholesterol, triglycerides and glucose are higher in young men with a paternal history of premature myocardial infarction than in age- and sex-matched controls.

Aim: To test the hypothesis that insulin resistance constitutes the biological expression of increased coronary risk in these subjects.

Design: A total of 407 male university students with a paternal history of premature myocardial infarction (cases) and 415 age- and sex-matched controls were investigated for differences in insulin sensitivity.

Methods: Four methods of assessing insulin sensitivity were used: (i) insulin and glucose responses to an oral glucose tolerance test (OGTT); (ii) insulin and glucose responses to an oral fat tolerance test (OFTT); (iii) minimal modelling of insulin and glucose data from a frequent sample intravenous glucose tolerance test performed on a subset of 55 cases and 50 controls and (iv) homeostasis model assessment (HOMA) of insulin resistance.

Results: The OFTT glucose response discriminated between cases and controls, with a smaller fall in glucose in cases compared with controls. The negative area under the glucose curve (AUC) (mean [standard error of the mean (SEM)]) was -1.42 (0.09) mmol min/L in cases and -1.76 (0.09) in controls ( P = 0.004). Peak height (mean [SEM]) was -0.65 (0.02) mmol/L in cases and -0.73 (0.02) in controls ( P = 0.007). The insulin responses were similar in cases and controls. Insulin AUC (mean [SEM]) was 161 (10) mU min/L in cases and 148 (10) in controls ( P = 0.34). This combination of findings suggests that insulin-stimulated glucose uptake was reduced in the cases. These findings were consistent across European regions. None of the other methods revealed any differences between cases and controls.

Conclusion: In young men with a paternal history of myocardial infarction, an OFTT detects altered insulin sensitivity that is not identified by an OGTT, minimal modelling or HOMA.