bluuebunny/crossref_metadata_2025_split huggingface dataset:
Total Carbon Dioxide Measured by the Vitros Enzymatic Method
Authors: Frezzotti Annarita , Margarucci Gambini Anna Maria , Coppa Gilberto , De Sio Giuseppina 
Published: October 2004

Abstract
We evaluated the performance of an enzymatic method using dry chemistry for serum total carbon dioxide (tCO2) determination using a Vitros 500 analyser. Imprecision results were acceptable and the linearity was verified for concentrations within a range of 5.5–39.2 mmol/l, i.e. ymeasured = 0.93 xcalculated +1.32, r = 0.99. The Vitros tCO2 method was unaffected by haemoglobin at all concentrations tested. Significant interference was caused by bilirubin at concentrations higher than 30 μmol/l; the addition of bilirubin lowered the apparent values for tCO2 dose-dependently. Serum tCO2 results were practically the same as those for plasma. The reference interval for venous tCO2 concentrations in a healthy population was: 22.4–34.2 mmol/l (mean: 28.3 mmol/l). Comparison of venous serum tCO2 results assayed using the Vitros method with bicarbonate (HCO3
−) values calculated by blood gas determination of pCO2 and pH in arterial blood samples gave poor agreement, r = 0.58. The data revealed a mean difference of 5.48 ± 3.09 mmol/l between the tCO2 measurements and calculated bicarbonate. This was statistically (p = 0.01) and clinically significant. We conclude that the Vitros method provides reliable tCO2 results in venous serum but this method must not be used as an interchangeable alternative to calculated arterial bicarbonate in order to avoid confusion, misinterpretation of results and erroneous therapeutic decisions.
Evaluation of Glucocard Memory 2 and Accutrend® Sensor Blood Glucose Meters
Authors: Arens Sofie , Moons Veronique , Meuleman Paul , Struyf Frank , Zaman Zahur 
Published: October 2004

Abstract
The performance and practicability of 2 blood glucose meters (Glucocard Memory 2 and Accutrendr sensor) were evaluated. Both glucose meters produced acceptably precise results in the hyper- and normoglycaemic concentration ranges. In the hypoglycaemic concentration range, the imprecision of Accutrend® sensor was much higher than recommended by the American Diabetes Association. Within-run coefficients of variation for Glucocard Memory 2 were 6.3 %, 3.9 % and 2.4 % at glucose concentrations of 1.7 mmol/l, 5.8 mmol/l and 11.7 mmol/l, respectively; for Accutrend® sensor these were 15.2 %, 5.0 % and 1.2% at respective concentrations of 0.9 mmol/l, 4.2 mmol/l and 19.6 mmol/l. Between-day coefficients of variation for Glucocard Memory 2 were 4.8 % and 3.5 % at glucose concentrations of 3.9 mmol/l and 17.2 mmol/l, respectively and for Accutrend® sensor they were 3.8 % and 2.9 % at glucose concentrations of 3.8 mmol/land 18.7 mmol/l, respectively. Results were linear over a range of 1.6 mmol/l–29.7 mmol/l for Glucocard Memory 2 and 1.6 mmol/l–33.3 mmol/l for Accutrend® sensor. Results of both blood glucose meters correlated closely with the hexokinase/glucose-6-phosphate dehydrogenase laboratory method. Ninety-eight percent of both Glucocard Memory 2 and Accutrend® sensor results were within 20 % of the comparison method values. Ninety-three percent of the Glucocard Memory 2 and 96 % of the Accutrend® sensor results were within 15 % of the comparison method results. An inverse relation between the glucose readings and haematocrit values was observed for both blood glucose meters in the hyperglycaemic range and this effect was more pronounced for Accutrend r sensor. In the normo- and hypoglycaemic ranges the effect was insignificant and absent, respectively. Minimum sample volume for Glucocard Memory 2 was 3 μl and for Accutrend® sensor it was 9 μl. Lower sample volumes gave erroneous results. Presenting more than the required volume had no effect on results.
Evaluation of Circulating Type I Procollagen Propeptides in Patients with Paget's Disease of Bone
Authors: Bonnin Maria R. , Moragues Carmen , M. Nolla Juan , Lirón Francisco J. , Roig-Escofet Daniel , Navarro Miguel A. 
Published: October 2004

AbstractWe evaluated circulating aminoterminal and carboxyterminal propeptides of type I procollagen and total alkaline phosphatase levels in eighty consecutive patients affected by Paget's disease of bone. We compared the biochemical data with the extent of bone disease calculated on the basis of the bone scintigraphic indices.Serum aminoterminal propeptide of type I procollagen levels were high in 77% of patients, serum carboxyterminal propeptide of type I procollagen levels in 22% and serum total alkaline phosphatase levels in 76%. We found significant correlations between the three markers studied. The three biochemical markers correlated significantly with the bone scintigraphic activity indices, but the highest correlation coefficient was between the aminoterminal propeptide and total alkaline phosphatase.We conclude that there is a discrepancy between serum levels of the propeptides studied in relation to Paget's disease of bone. The sensitivity of the carboxyterminal propeptide of type I procollagen in this disease is low. In contrast the aminoterminal propeptide may be as sensitive a marker for the evaluation of this disorder as total alkaline phosphatase, and in addition may be more specific.
Genetic Approach for Insulin-Independent Diabetes Mellitus in Clinical Practice
Authors: Danze Pierre-Marie , Penet Sylvie , Fajardy Isabelle 
Published: October 2004

Abstract
Insulin-independent diabetes mellitus (IDDM) is a polygenic disease with an environmental component. Technological advances and large collection families allowed genetic factors understanding. On clinical practice, two questions could be asked. First, will the genetic markers be of interest in disease prediction either in family studies or in the main population? Secondly, will the genetic approach explain the physiopathological process of the disease? Initially, the gene candidate approach led to the identification of two important loci: Linkage with the human leukocyte antigen (HLA) locus showed the importance of the autoimmune part. Linkage of insulin-independent diabetes mellitus with insulin locus gave a mechanistic answer for disease susceptibility. These two loci can be used as prediction markers, but only in family studies. Since 1993, a whole genome approach has been performed and has led to the identification of other susceptibility loci. These initial results are in progress and should have important implications for public health strategies.
An Enzymatic Method for the Determination of Free Fatty Acids in Serum/Plasma
Authors: Kızıltunç Ahmet , Akçay Fatih 
Published: October 2004

Abstract
Estimation of serum free fatty acids (FFA) in serum based on the formation of inorganic phosphate has been simplified by eliminating complex stages. The principle of the present method is based on breakdown of pyrophosphate, formed by thioesterification of free fatty acids with ATP and CoA with the aid of acyl-CoA synthetase (EC 6.2.1.3) to inorganic phosphate. This is measured using the reaction with molybdate. The reaction equations are as follows:
The recovery of free fatty acids was 96 %. The interferences of citrate, phosphatidylserine, succinate, ascorbic acid and lecithin were between 0.5 and 2 %. The correlation between the new enzymatic and the classic enzymatic method was 0.966. The lower detection limit was 0.018 mmol/I. The method was linear between 0.02 and 2.0 mmol/I. The within-assay and between-assay imprecision (CV) of control sera was 5.5 % and 8 %, respectively.
Specificity of Cardiac Troponins I and T in Renal Disease
Authors: Willging Stefan , Keller Frieder , Steinbach Gerald 
Published: October 2004

Abstract
We investigated and compared serum levels of cardiac troponins I(cTnI) and cardiac troponin T (cTnT) in 85 renal patients (chronic renal impairment n = 23, continuous ambulatory peritoneal dialysis n = 20, hemodialysis n = 42). Patients with the following conditions were excluded: myocardial infarction, angina pectoris, liver disease, malignant neoplasms, enforced physical activity, skeletal muscle trauma, myositis, rhabdomyolysis and seizures. Troponin T was measured by the second generation cTnT-ELISA with a cutoff value = 0.1 μg/l. Troponin I was measured by a cTnI immunoassay analyser with a cut-off value = 2.0 μg/l. Additionally, creatine kinase (CK), CK-MB activity, CKMB mass concentration and myoglobin levels were measured. Specificity was determined as the fraction of true-negative cases compared to the total number of false-positive and true-negative cases. Specificity for cTnT was 96 % [78–100] in patients with renal impairment (creatinine > 150 μmol/l), 95 % [75–100] in continuous ambulatory peritoneal dialysis patients, but in hemodialysis patients it was 75 % [53–92] for short-term hemodialysis (< 1 year) and 46 % [24–68] for long-term hemodialysis (> 1 year). There was a weak correlation between cTnT levels and duration of hemodialysis therapy (r = 0.35, n = 34, p < 0.04). Specificity for cTnI in renal impairment patients was 96 % [78–100] and 100 % [84–100] in continuous ambulatory peritoneal dialysis and all hemodialysis patients. None of the studied markers showed higher specificity than cTnI. Only myoglobin was less specific than cTnT in hemodialysis patients. Different clearances of the troponins during dialysis (investigated by pre-hemodialysis and post-hemodialysis levels) cannot explain the discordant results of cTnT and cTnI.
Conclusion: Cardiac troponin I exhibits higher specificity than cardiac troponin T in hemodialysis patients. Uremic myopathy could explain falsely elevated troponin T levels in hemodialysis patients.
Fucosylation and Galactosylation of IgG Heavy Chains Differ between Acute and Remission Phases of Juvenile Chronic Arthritis
Authors: Flögel Mirna , Lauc Gordan , Gornik Ivan , Maček Boris 
Published: October 2004

Abstract
Oligosaccharide structures are attached to nearly all membrane and serum proteins, and their composition changes significantly in many diseases. We have analysed glycosylation of IgG heavy chains in 34 patients with juvenile chronic arthritis and 13 control individuals. IgG was purified from 0.7 ml of serum, separated by electrophoresis and transferred on to polyvinylidene difluoride (PVDF) membrane. Ricinus communis agglutinin (RCA I) and Bandeirea simplicifolia (BSA II) and Ulex europaeus (UEA I) lectins were used to measure galactose, N-acetylglucosamine and fucose, respectively. While there was no significant difference in average levels of galactose and N-acetylglucosamine, patients with juvenile chronic arthritis had 2.4 times more fucose attached to IgG heavy chains than control individuals. A different picture emerged when patients were divided into those with acute disease and those in remission. Patients in whom juvenile chronic arthritis was currently active had significantly lower levels of galactose than those in remission, in whom galactose levels were comparable to the control group. Fucose levels in both groups of patients were significantly higher than in the control group. These results show that whereas de-galactosylation is a good test to detect and measure the activity of juvenile chronic arthritis, increased fucosylation is a much more reliable measure for diagnosis of the disease itself.
Analytical Evaluation of an Improved Procedure for Measuring Thyrotropin
Authors: González-de-la-Presa Bernardino , Palacios Gonzalo , Bonnin Rosa , Martinez Jose M. , Navarro Miguel A. 
Published: October 2004

Abstract
The analytical characteristics of the AxSYM Ultrasensitive hTSH-II (Abbott Laboratories) procedure for quantitation of serum thyrotropin (TSH) concentration were evaluated. Within- and between-run imprecisions, functional sensitivity, analytical interval and relative inaccuracy with respect to the Enzymum-Test TSH (Boehringer Mannheim) were studied. In all cases, the within-run and between-run of coefficients variation were lower than 6.69 % and 8.12 % respectively. The measurement range was tested with serial dilutions of a serum with a high thyrotropin concentration, and the procedure was found to be linear up to at least 87.0 mIU/l. The functional sensitivity was 0.018 mIU/l. The relative inaccuracy study (Passing-Bablok non-parametric linear regression) produced the following linear equation:
(AxSYM) = 1.02. (ES-700)−0.03 mIU/l, with 95 % confidence intervals of a(−0.05; −0.01); b(0.98; 1.06).
Acute Exogenous Elevation of Plasma Free Fatty Acids Does Not Influence the Plasma Magnesium Concentration
Authors: de Valk Harold W. , Bianchi Rutgert , van Rijn Herman J.M. , Erkelens D. Willem 
Published: October 2004

Abstract

Objective: Plasma non-esterified (free) fatty acid concentrations rise as a consequence of stimulated endogenous lipolysis and are inversely related to the plasma magnesium concentration when plasma adrenaline concentration is increased. The aim of the study was to test whether high plasma non-esterified fatty acid concentration after infusion of non-esterified fatty acids decreases plasma magnesium concentration.

Methods: Twelve healthy subjects received 500 ml Intralipid or saline in a randomised, cross-over, double-blind design. Infusion of Intralipid results in an isolated elevation of plasma non-esterified fatty acid concentration. Plasma magnesium concentration was determined at baseline and every 30 minutes; plasma nonesterified fatty acid and triglyceride concentrations at baseline and after 120 minutes.

Results: Initial plasma magnesium, non-esterified fatty acid, and triglyceride concentrations were similar in both groups. A significant increase in plasma non-esterified fatty acids (2.42 ± 0.96 mmol/l vs 0.58 ± 0.23 mmol/l, p = 0.00013) and triglyceride (median and 95th percentile 5.36 (7.35) mmol/l vs 1.18 (1.92) mmol/l, p = 0.003) concentrations was seen with Intralipid. Plasma magnesium concentration increased significantly after Intralipid (0.89 ± 0.09 mmol/l vs 0.81 ± 0.06 mmol/l, p = 0.007). No significant changes were seen with saline. A positive association was found between the change in plasma magnesium and triglyceride concentrations (r = 0.85, p = 0.001).

Conclusion: Acute infusion of non-esterified fatty acids from an exogenous source does not result in a fall in plasma magnesium concentration, indicating that the circulating non-esterified fatty acids play no part in a decrease in plasma magnesium concentration. The high circulating non-esterified fatty acid levels and the fall in plasma magnesium concentration are both a consequence of intracellular lipolysis.
Teaching and Training Laboratory Professionals for the 21st Century
Authors: Dominiczak Marek H. 
Published: October 2004

Abstract
Educational activities are a background to research and to a dynamic, developing discipline. The principles now being applied in undergraduate curricula are applicable to teaching and training in laboratory medicine. A fresh look at the education and training and an implementation of new educational techniques is necessary to prepare a cadre of individuals who will be developing laboratory medicine in the 21st century.
The Effect of Ascorbic Acid Ingestion on the Biochemical and Physicochemical Risk Factors Associated with Calcium Oxalate Kidney Stone Formation
Authors: Auer Bronwyn Leigh , Auer Derek , Lawrence Rodgers Allen 
Published: October 2004

Abstract
The present study was undertaken to determine the effect of ingestion of large doses of vitamin C on urinary oxalate excretion and on a number of other biochemical and physicochemical risk factors associated with calcium oxalate urolithiasis. A further objective was to determine urinary ascorbate excretion and to relate it qualitatively to ingested levels of the vitamin and oxalate excretion. Ten healthy males participated in a protocol in which 4 g ascorbic acid was ingested for 5 days. Urines (24 h) were collected prior to, during and after the protocol. The urine collection procedure was designed to allow for the analysis of oxalate in the presence and absence of an EDTA preservative and for the analysis of ascorbic acid by manual titration using 2,6 dichlorophenolindophenol. Physicochemical risk factors such as the calcium oxalate relative supersaturation and Tiselius risk index were calculated from urine composition. The results showed that erroneously high analytical oxalate levels occur in the asence of preservative. In the preserved samples there was no significant increase in oxalate excretion at any stage of the protocol. Ascorbate excretion increased when vitamin C ingestion commenced but levelled out after 24 hours suggesting that saturation of the metabolic pool is reached within 24 hours after which ingested ascorbic acid is excreted unmetabolized in the urine. While transient statistically significant changes occurred in some of the biochemical risk factors, they were not regarded as being clinically significant. There were no changes in either the calcium oxalate relative supersaturation or Tiselius risk index. It is concluded that ingestion of large doses of ascorbic acid does not affect the principal risk factors associated with calcium oxalate kidney stone formation.
Development of an HPLC Assay to Study the Effect of Endogenous and Exogenous Substances on Heat-Induced Aggregation of Human Serum Albumin
Authors: Saso Luciano , Casini Maria Luisa , Valentini Giovanni , Mattei Eleonora , Panzironi Claudio , Silvestrini Bruno 
Published: October 2004

Abstract
The mechanism of action of non-steroidal anti-inflammatory drugs which are used in high doses in chronic inflammatory conditions is not clearly understood. Their known protein-stabilizing properties could play a significant role. The inhibition of cyclooxygenase may not be essential for their anti-rheumatic activity, since compounds with strong anti-denaturant properties and devoid of anti-inflammatory activity were shown to be effective in an experimental model of rheumatoid arthritis. Hence, to develop new anti-rheumatic drugs it is essential that a simple in vitro method to evaluate the anti-denaturant activity of endogenous and exogenous compounds is available.
We developed a new assay, using gel permeation high performance liquid chromatography, to study the effect of endogenous and exogenous compounds on heat-induced aggregation of human serum albumin in conditions in which protein precipitation does not occur. Non-steroidal anti-inflammatory drugs like diclofenac, ibuprofen and naproxen inhibited the aggregation of albumin at low concentrations (EC50 10−4–10−5 mol/l) comparable to those active in a classical turbidimetric method, whereas the effect of weak stabilizers, like sodium cloride and formic, fumaric, maleic, malonic, and succinic acid (EC50 10−1–10−2 mol/l in the Mizushima test) was not detectable.
Furthermore, the HPLC assay allowed the examination of a number of coloured substances, including bilirubin, which appeared to be a strong stabilizer of its physiological carrier, albumin.
These data could be clinically relevant, since the drugs examined are used at very high doses in rheumatoid arthritis and related conditions, with plasma levels that could cause significant stabilization of serum albumin and perhaps other proteins.
The Predictive Value of Several Markers in the Progression to Acquired Immunodeficiency Syndrome
Authors: Planella Teresa , Cortés Mariano , Martínez-Brú Cecília , Barrio Josep , Sambeat Ma Antònia , González-Sastre Francesc 
Published: October 2004

Abstract
Serum β2-microglobulin, neopterin, immunoglobulins A, G and M, adenosine deaminase and CD4+ lymphocyte count were evaluated as predictors of progression of HIV-1 infection to AIDS. A population of HIV-1 seropositive, initially asymptomatic men (n=213) and women (n=101) was followed up quarterly.
We estimated the AIDS-free time using the actuarial method (median survival time 47.2 months). Cox proportional hazard analysis revealed that all markers studied were significant (p<0.05) in relation to progression to AIDS. The best markers for predicting progression to AIDS were, in descending order, CD4+ lymphocyte count, β2-microglobulin, IgA, neopterin, IgG, IgM and adenosine deaminase. On stratifying population into four groups (devided at percentiles 25, 50 and 75—from group 1, with values nearest to reference ranges, to group 4, with most abnormal values) we observed statistically significant differences (p<0.05) for all markers except for adenosine deaminase. The relative risk from the Cox proportional hazards model were used to quantify the effects of the best markers and compared to the risk obtained in group 1.
CD4+ lymphocyte count was the best predictor of progression to AIDS. When considering β2-microglobulin and CD4+ together, the relative risk in the group with lowest CD4+ cell count (group 4) ranged from 25.6% (with lower β2-microglobulin values) to 41.1% (with higher β2-microglobulin values). Similar results were obtained when considering neopterin and CD4+ together. The addition of β2-microglobulin or neopterin values to CD4+ lymphocyte count improved the predictive value of CD4+ lymphocyte count.
The Increase of Plasma Homocysteine Concentrations with Age Is Partly due to the Deterioration of Renal Function as Determined by Plasma Cystatin C
Authors: Norlund Lena , Grubb Anders , Fex Göran , Leksell Håkan , Nilsson Jan-Erik , Schenck Henning , Hultberg Björn 
Published: October 2004

Abstract
One of the main determinants of plasma homocysteine in healthy subjects is serum creatinine. In the present study, we therefore investigated the relation between plasma homocysteine concentration, serum creatinine and a new marker for glomerular filtration rate, plasma cystatin C concentration. Cystatin C reflects the glomerular filtration better than serum creatinine and is not related to the muscle mass and formation of creatinine. The study group consisted of 255 healthy subjects from a well-defined area in the southern part of Sweden.
The concentration of plasma homocysteine was increased in men compared to women. This difference disappeared when men and women were stratified by serum creatinine values. Statistically significant correlations were noted between plasma homocysteine and age, plasma cystatin C and serum creatinine. It is shown that plasma homocysteine is not only correlated to serum creatinine as a result of renal function but also as a result of the relationship between homocysteine production and creatine-creatinine synthesis. Using linear regression we were able to show that plasma cystatin C had a higher explanatory value than age. Serum creatinine showed a lower explanatory power than age. The findings in the present study might suggest that the increase of plasma homocysteine concentration with age could be partly due to the deterioration of renal function. Study
Serum CA 242: The Search for a Valid Marker of Pancreatic Cancer
Authors: Ventrucci Maurizio , Ubalducci Giuseppina Margaret , Cipolla Antonio , Panella Maria Antonietta , Ligabue Amedeo 
Published: October 2004

Abstract
Many efforts have been made to find valuable serum tumour markers which help the diagnosis of pancreatic cancer. In the present study we investigated the diagnostic value of CA 242 in comparison with two other routinely used tumour markers (CA 19–9 and CA 50). Two-hundred and seventy six subjects were enrolled in this study: 46 patients with pancreatic cancer preoperatively, 53 with chronic pancreatitis, 28 with acute pancreatitis, 49 with other malignancies, 50 with miscellaneous non-neoplastic digestive diseases, and 50 healthy subjects. CA 242 was determined in serum by means of a two-step fluoroimmunometric assay. Sensitivities of CA 242, CA 19–9 and CA 50 for pancreatic cancer when all patients were considered were 41.3%, 54.3% and 47.8%, respectively (95% specificity level). No significant improvement was achieved by combination of CA 242 with CA 19–9 and/or CA 50. Cholestasis affected serum levels of CA 242 in patients without pancreatic cancer, but not in those with this tumour. The metastatic stage of pancreatic cancer appeared to influence the levels of CA 242. In conclusion, CA 242 serum assay does not seem to improve diagnostic accuracy for pancreatic cancer compared to CA 19–9 and CA 50.