bluuebunny/crossref_metadata_2025_split huggingface dataset:
Serum cystatin C concentration as a marker of acute renal dysfunction in critically ill patients
Authors: Villa Patricia , Jiménez Manuel , Soriano Maria-Cruz , Manzanares Jesus , Casasnovas Pilar 
Published: February 2005

Abstract
Introduction
In critically ill patients sudden changes in glomerular filtration rate (GFR) are not instantly followed by parallel changes in serum creatinine. The aim of the present study was to analyze the utility of serum cystatin C as a marker of renal function in these patients.

Methods
Serum creatinine, serum cystatin C and 24-hour creatinine clearance (CCr) were determined in 50 critically ill patients (age 21–86 years; mean Acute Physiology and Chronic Health Evaluation II score 20 ± 9). They did not have chronic renal failure but were at risk for developing renal dysfunction. Serum cystatin C was measured using particle enhanced immunonephelometry. Twenty-four-hour body surface adjusted CCr was used as a control because it is the 'gold standard' for determining GFR.

Results
Serum creatinine, serum cystatin C and CCr (mean ± standard deviation [range]) were 1.00 ± 0.85 mg/dl (0.40–5.61 mg/dl), 1.19 ± 0.79 mg/l (0.49–4.70 mg/l), and 92.74 ± 52.74 ml/min per 1.73 m2 (8.17–233.21 ml/min per 1.73 m2), respectively. Our data showed that serum cystatin C correlated better with GFR than did creatinine (1/cystatin C versus CCr: r = 0.832, P < 0.001; 1/creatinine versus CCr: r = 0.426, P = 0.002). Cystatin C was diagnostically superior to creatinine (area under the curve [AUC] for cystatin C 0.927, 95% confidence interval 86.1–99.4; AUC for creatinine 0.694, 95% confidence interval 54.1–84.6). Half of the patients had acute renal dysfunction. Only five (20%) of these 25 patients had elevated serum creatinine, whereas 76% had elevated serum cystatin C levels (P = 0.032).

Conclusion
Cystatin C is an accurate marker of subtle changes in GFR, and it may be superior to creatinine when assessing this parameter in clinical practice in critically ill patients.
Randomized Comparison of Low Molecular Weight Heparin and Coumarin Derivatives on the Survival of Patients With Cancer and Venous Thromboembolism
Authors: Lee Agnes Y.Y. , Rickles Frederick R. , Julian Jim A. , Gent Michael , Baker Ross I. , Bowden Chris , Kakkar Ajay K. , Prins Martin , Levine Mark N. 
Published: February 2005

Purpose Experimental studies and indirect clinical evidence suggest that low molecular weight heparins may have antineoplastic effects. We investigated the influence of a low molecular weight heparin dalteparin on the survival of patients with active cancer and acute venous thromboembolism. Patients and Methods Survival data were examined in a posthoc analysis in patients with solid tumors and venous thromboembolism who were randomly assigned to dalteparin or a coumarin derivative for 6 months in a multicenter, open-label, randomized, controlled trial. All-cause mortality at 12 months was compared between treatment groups in patients with and without metastatic malignancy. The effect of dalteparin on survival was compared between the two patient subgroups. Results During the 12-month follow-up period, 356 of 602 patients with solid tumors and acute venous thromboembolism died. Among patients without metastatic disease, the probability of death at 12 months was 20% in the dalteparin group, as compared with 36% in the oral anticoagulant group (hazard ratio, 0.50; 95% CI, 0.27 to 0.95; P = .03). In patients with metastatic cancer, no difference in mortality between the treatment groups was observed (72% and 69%, respectively; hazard ratio, 1.1; 95% CI, 0.87 to 1.4; P = .46). The observed effects of dalteparin on survival were statistically significantly different between patients with and without metastatic disease (P = .02). Conclusion The use of dalteparin relative to coumarin derivatives was associated with improved survival in patients with solid tumors who did not have metastatic disease at the time of an acute venous thromboembolic event. Additional studies are warranted to investigate these findings.
The Effect of Low Molecular Weight Heparin on Survival in Patients With Advanced Malignancy
Authors: Klerk Clara P.W. , Smorenburg Susanne M. , Otten Hans-Martin , Lensing Anthonie W.A. , Prins Martin H. , Piovella Franco , Prandoni Paolo , Bos Monique M.E.M. , Richel Dick J. , van Tienhoven Geertjan , Büller Harry R. 
Published: February 2005

Purpose Studies in cancer patients with venous thromboembolism suggested that low molecular weight heparin may prolong survival. In a double-blind study, we evaluated the effect of low molecular weight heparin on survival in patients with advanced malignancy without venous thromboembolism. Methods Patients with metastasized or locally advanced solid tumors were randomly assigned to receive a 6-week course of subcutaneous nadroparin or placebo. The primary efficacy analysis was based on time from random assignment to death. The primary safety outcome was major bleeding. Results In total, 148 patients were allocated to nadroparin and 154 patients were allocated to placebo. Mean follow-up was 1 year. In the intention-to-treat analysis the overall hazard ratio of mortality was 0.75 (95% CI, 0.59 to 0.96) with a median survival of 8.0 months in the nadroparin recipients versus 6.6 months in the placebo group. After adjustment for potential confounders, the treatment effect remained statistically significant. Major bleeding occurred in five (3%) of nadroparin-treated patients and in one (1%) of the placebo recipients (P = .12). In the a priori specified subgroup of patients with a life expectancy of 6 months or more at enrollment, the hazard ratio was 0.64 (95% CI, 0.45 to 0.90) with a median survival of 15.4 and 9.4 months, respectively. For patients with a shorter life expectancy, the hazard ratio was 0.88 (95% CI, 0.62 to 1.25). Conclusion A brief course of subcutaneous low molecular weight heparin favorably influences the survival in patients with advanced malignancy and deserves additional clinical evaluation.
Clinically Meaningful Improvement in Symptoms and Quality of Life for Patients With Non-Small-Cell Lung Cancer Receiving Gefitinib in a Randomized Controlled Trial
Authors: Cella David , Herbst Roy S. , Lynch Thomas J. , Prager Diane , Belani Chandra P. , Schiller Joan H. , Heyes Anne , Ochs Judith S. , Wolf Michael K. , Kay Andrea C. , Kris Mark G. , Natale Ronald B. 
Published: February 2005

Purpose Evaluation of disease-related symptom improvement rate by the Lung Cancer Subscale (LCS) of the Functional Assessment of Cancer Therapy-Lung (FACT-L) questionnaire was a coprimary end point of the pivotal phase II trial of gefitinib (Iressa; AstraZeneca, Wilmington, DE) conducted in the United States. This report includes the results of analyses exploring the relationship between weekly LCS scores and radiographic response and survival, as well as detailed protocol-specified analysis of symptom and quality-of-life data. Patients and Methods In this trial, 216 symptomatic patients with advanced non-small-cell lung cancer (NSCLC) who had at least two prior chemotherapy regimens received gefitinib 250 or 500 mg/d. Disease-related symptoms were assessed weekly and quality of life was assessed monthly by LCS and FACT-L, respectively. Results Symptom improvement was rapid and correlated with tumor response and survival. At the recommended gefitinib dose of 250 mg/d, median overall survival times were 13.6 and 4.6 months for patients with and without symptom improvement, respectively, and 9.7 months for patients with symptom improvement without tumor response. Among patients with stable disease or disease progression, those with symptom improvement had significantly better overall survival than those without improvement. At 250 mg/d, 30% of patients showed a quality-of-life improvement that was correlated with tumor response. Conclusion This triadic analysis of response, survival, and symptom data supports the hypothesis that tumor response and symptom response are related and that each predicts survival. Among these NSCLC patients treated with gefitinib, symptom improvement was complementary to and, for most patients, preceded evidence of radiographic regression.
Interpretation of alpha-fetoprotein concentrations in cerebrospinal fluid of infants
Authors: Coakley J , Kellie SJ , Nath C , Munas A , Cooke-Yarborough C 
Published: February 2005

Background: There are no published reference intervals for concentrations of alpha-fetoprotein (AFP) in the cerebrospinal fluid (CSF) of normal infants. The presence of abnormal concentrations of AFP in plasma or CSF may indicate the presence of a teratoma or a germ cell tumour with yolk sac elements. We measured CSF AFP in infants who did not have malignancy in order to determine its reference intervals. Methods: AFP was measured in the CSF and/or plasma in 128 infants. Of these, 91 infants had CSF AFP measurements, 94 infants had plasma AFP measurements and in 60 infants AFP concentrations were determined in paired CSF and plasma samples. The patients ranged in age from 1 to 110 days. Both CSF and plasma AFP concentrations were measured by a microparticle enzyme immunoassay using an AxSYM analyser. Results: Using ages corrected for prematurity, the median CSF AFP concentration for babies -69 to 31 days old was 61 kIU/L (5th-95th centile: 2-889 kIU/L), while the median CSF AFP concentration for infants 32 to 110 days was 1.2 kIU/L (5th-95th centile: 0.1-12.5 kIU/L). By age 6 weeks, the concentrations were close to those found in adult plasma and all CSF AFP concentrations from infants with a corrected age over 2 months were <3 kIU/L. Conclusion: We have defined reference intervals for CSF AFP concentrations in infants. These results may assist in the diagnosis of CNS tumours, particularly congenital CNS tumours containing yolk sac elements.
Japanese standard reference material JDS Lot 2 for haemoglobin A1c. II: Present state of standardization of haemoglobin A1c in Japan using the new reference material in routine clinical assays
Authors: Tominaga Makoto , Makino Hideichi , Yoshino Gen , Kuwa Katsuhiko , Takei Izumi , Aono Yukuko , Hoshino Tadao , Umemoto Masao , Shimatsu Akira , Sanke Tokio , Kuwashima Masamichi , Taminato Tomohiko , Ono Junko 
Published: February 2005

Background: In 2001, the Committee on Standardization of Laboratory Testing Related to Diabetes Mellitus of the Japan Diabetes Society (JDS) prepared and certified a new reference material for haemoglobin A1c (HbA1c), Lot 2. The standardization programme for HbA1c measurement in Japan is currently based on Lot 2, although some laboratories still use the previous material (Lot 1). The values assigned to Lot 2 were based on the consensus values for Lot 1 and should give the same results. Therefore, there should be no difference in the measured values no matter which calibrators are used. The Committee conducted a domestic survey in order to confirm this relationship. Method: In November 2002, four samples for HbA1c assay were sent to 795 laboratories as part of a national survey in Japan. Assays were performed using the laboratories' routine clinical methods. The coefficients of variation (CVs) of the reported values from all laboratories for the samples were calculated in order to determine the current level of standardization in Japan. Results: The overall CVs in the measured values for the four samples ranged from 2.7% to 4.0%. Values from laboratories using calibrators based on Lots 1 and 2 were similar. Conclusion: The present state of standardization for the routine measurement of HbA1c in Japan, as indicated by the 2002 survey, is excellent. This should aid in the eventual conversion of Lot 2 to IFCC-based values from the results of the 2002 national HbA1c survey.
Plasma aluminium: a redundant test for patients on dialysis?
Authors: Gault PM , Allen KR , Newton KE 
Published: February 2005

Background: Aluminium toxicity as a cause of dementia, osteodystrophy and anaemia in patients receiving renal dialysis was first described in the 1970s and led to the regular monitoring of aluminium in plasma and dialysate water. However, aluminium phosphate binders have now been replaced by calcium-based binders or sevelamer and reverse osmosis (RO) water is used in the preparation of dialysate fluid. This has reduced the exposure of dialysis patients to aluminium and it is therefore opportune to review aluminium monitoring in patients undergoing regular renal dialysis. Methods: Plasma and water aluminium results were audited over the period January 2000-January 2004, with results obtained from nine renal dialysis units in the UK. Patients with a plasma aluminium concentration in the toxic range (>3.7 μmol/L) were followed up by contacting the relevant consultant. Results: Plasma aluminium results were collected on 1626 patients over the fouryear period (mean = 0.47 μmol/L, median = 0.3 μmol/L, range 0.07-30.26 μmol/L, n = 5918). Forty-six patients had an aluminium concentration >3.7 μmol/L and nine were not retested. Only three patients had a repeat aluminium concentration >2.2 μmol/L, one being a result of desferrioxamine treatment, with no further clinical information available on the other two. All renal units are using RO water to prepare dialysate and aluminium-based phosphate binders are no longer prescribed. Only one of 212 RO water aluminium concentrations measured was >10 μg/L. Patients with clinical symptoms of overt aluminium toxicity were not identified in this population. Conclusion: The role of aluminium monitoring in long-term renal dialysis patients needs re-evaluation. Regular monitoring of plasma aluminium may not be required, but should be considered in any patient showing signs or symptoms of aluminium toxicity or exposed to a contaminated water supply. It is more important that RO water supplies are maintained and monitored. Environmental aluminium as a source of sample contamination should be considered and eliminated during blood collection and sample processing.
Troponin reporting in Australia in 2003
Authors: Davey Richard X 
Published: February 2005

Background and method: This study uses a cross-sectional survey by questionnaire of Australia's pathology laboratories to describe how they report chemical markers for myocardial necrosis. Results: The questionnaire was sent to 364 laboratories; 346 (95%) responded. Reporting data were obtained for 222 instruments used to analyse markers of myocardial necrosis, some 81% of all those in Australia. All laboratories use a troponin measurement. Reports from 132 analysers (59% of total) provide one cut-off point for the diagnosis of myocardial necrosis and 90 (41%) two cut-off points. The chosen cut-off points vary. The upper limit of 'healthy' is cited, alone, in 40 reports (18%); at this level, in 2002 no analysers predictably met required precision standards. Only 50% of all reports carry some explanatory comment; only 16% of all reports cite the source of the data. Conclusions: Troponin is used throughout Australia to help diagnose myocardial necrosis, but there is little order in the way the results are reported or interpreted.
Conjugated bilirubin measurements in Gilbert's syndrome: method dependence
Authors: Thurlow Vanessa , Bailey Ian R , Griffiths Wyn 
Published: February 2005

Background: Introducing new methodology often requires alteration to reference ranges and may cause inconvenience. Reagent suppliers may not have validated reference ranges quoted in their method sheets. When ratios of analytes are important, as for conjugated and unconjugated bilirubin, the combined changes can cause confusion. Methods: The effect on bilirubin result interpretation following a change from Vitros (E950) dry slide technology to the Bayer ADVIA 1650 wet chemistry system was studied. Results and conclusion: Over-estimation of conjugated bilirubin without an appropriate reference range can cause interpretative confusion. It is important to identify key patient groups likely to be affected by method changes well in advance. These need to be worked up in addition to reference range checks. It is unwise to rely on manufacturers for advice in this area. This report gives conjugated or direct bilirubin and total bilirubin values obtained using the above methods in nine patients with Gilbert's syndrome.
Economic Exploration Assessment of Hydrocarbon Leakage across a Fault. II. Charged Sand before Faulting
Authors: Lerche Ian 
Published: February 2005

That faults cross-cut sands and cause leakage of hydrocarbons, either out of the upthrown and downthrown sand system or from the downthrown sand to the upthrown sand, is well known The decision to drill either or both of such sands depends on what it is one assesses as the likely hydrocarbon potential of the total system and also for each sand independently. This paper provides a quantitative procedure to determine a strategy for deciding what to drill. The economic worth for such a sand system depends on the chances the sands were originally hydrocarbon charged, and on the leakage possibilities for each sand, together with the recharge of the upthrown sand from the downthrown sand, and seems not to have received a quantitative investigation to date. In addition, at the exploration stage the amount of detailed information about such a fault cut system is limited, so that any and all assessments of parameters influencing the economic worth are also uncertain. This paper shows how one can include uncertainties caused by such “fuzzy” parameters in attempting to decide on a drilling strategy geared to satisfying corporate mandated economic returns criteria. Numerical illustrations are given to show how the strategies to decide to drill either only the downthrown sand, or only the upthrown sand, or to drill both sands can be brought to a rational form so that corporate decision-makers can compare and contrast the three strategies under the same quantitative framework.
Economic Exploration Assessment of Hydrocarbon Leakage across a Fault. I. Charged Sand after Faulting
Authors: Lerche Ian 
Published: February 2005

This paper concerns itself with providing economic estimates for hydrocarbon Exploration when a sand is offset by a fault and when the downthrown part of the sand is later charged with hydrocarbons. The fault may leak, so that hydrocarbons can be transferred to the upthrown part of the sand body or may be leaked from the system and so lost. The costs of drilling the upthrown sand are usually less than those to drill the deeper sand. However, it is in general unknown what fraction of the original hydrocarbon charge is reassigned to the upthrown side and what fraction is leaked away. Also unknown is the probability that the fault leaks. The economic assessment is then made up of three possibilities: drill only the downthrown sand; drill only the upthrown sand; or drill both components of the sand. The concern is with estimating the best strategy to follow to maximize the value to be gained from the system. This paper shows how to provide such an economic assessment. The more complex problem of hydrocarbons already in the sand before the fault occurs will be taken up in the next paper, together with uncertainties and their influence on assessed worth, when none of the potential gains, costs, leak probability, or the chance the sands were hydrocarbon charged, are known with any degree of precision. The dominance of each to the uncertainty of economic worth will also be considered.
Polarising Ability of the Metal Surface Atoms of a Catalyst and the Work Function
Authors: Stokłosa Andrzej , Kurek Stefan S. , Laskowska Barbara 
Published: February 2005

An attempt was made to determine the polarising ability of metal surface atoms. On the basis of an analysis of the metal cohesive energy and the electron binding energy in ionic cores, a new parameter was proposed called the polarising ability of surface atoms as defined by the equation: [Formula: see text] where EEBE denotes the electron binding energy at the outermost shell of the ionic core, the product (αδG0sub) determines the surface Gibbs energy that is proportional (the quantity α denoting the proportionality factor) to the standard Gibbs energy of sublimation of the metal (δG0subM), r is the metallic radius (half the length of the metallic bond), ao is the radius of the first Bohr orbit and R is the Rydberg constant. It was shown that the above parameter is proportional to the work function and that, in a similar fashion to the ionisation energy of ions, this can indicate the polarising ability of the surface atoms. The correlation between the polarising ability parameter and the initial heat of adsorption of H2, O2, CO and N2, and between the limiting exchange current (log io) of the hydrogen evolution on metals, was demonstrated.
Dual Purpose Design of Small Wind Turbine Blades
Authors: Wood D. H. 
Published: February 2005

Experimental studies of the starting behaviour of small wind turbines have shown that the initial “idling period”, characterised by small rotor acceleration, is usually much longer than the subsequent period of rapid accleration to reach operational rotor speed. Idling obviously reduces the power generation potential of any turbine. The experimental results also imply that most starting torque is generated near the hub, whereas power-producing torque is concentrated near the tip. Therefore this paper considers the computational design of blades for small wind turbines for the dual purposes of (i) efficient power production at rated wind speeds and (ii) rapid starting at smaller wind speeds. Standard blade element theory is used to determine the power coefficient, which is the first objective function to be maximised. A modified blade element method gives the start, whose inverse is the second objective function. During the idling period, the blade angles of attack are relatively large, allowing the lift and drag to be modelled using “generic” flat-plate equations with a small adjustment for the particular aerofoil. No power is extracted from the wind while the blades are accelerated by the aerodynamic torque. Starting is deemed to be complete at a tip speed ratio representing the end of the idling period, which considerably less than the period for power generation. The design is by “differential evolution”. An initial population of blade types is generated randomly and allowed to evolve through random modification and selection of the fittest blades to comprise the next generation. The blade “genes” are the chord and pitch of each blade element; the aerofoil section is the same for all elements and all blades. In multi-objective optimisation, most interest focusses on the members of the population which have at least one objective function greater than every other member, as the final design is usually chosen from these blades. The geometry of the best power extracting blade obtained from the evolutionary optimisation was compared with that arising from standard blade element theory. Good agreement was found for the case of an aerofoil having a pronounced peak in its lift to drag ratio but only a small Reynolds number dependence in the lift coefficient at which the ratio is a maximum. Using an aerofoil with a much flatter lift to drag characteristic, the evolutionary method easily adapted to the significant Reynolds number dependence of the aerofoil characteristics. The effects of blade inertia and the resistive torque of the generator and drive train are also considered. In all cases studied, the best power-producing blade always had relatively poor starting performance, but it was usually possible to choose an alterntive blade with only a small reduction in power output but with a starting time decreased by a factor of around two.