bluuebunny/crossref_metadata_2025_split huggingface dataset:
Elevated Group 11 Phospholipase A2 Mass Concentration in Serum and Colonic Mucosa in Crohn's Disease
Authors: Haapamäki Markku M. , Grönroos Juha M , Nurmi Heimo , Söderlund Kristiina , Peuravuori Heikki , Alanen Kalle , Nevalainen Timo J. 
Published: October 2004

Abstract
Group II phospholipase A2 has been proposed to play an important role in the pathophysiology of inflammatory bowel diseases. This enzyme has also been linked to host defence mechanisms against bacteria. The current study aimed at measuring the mass concentrations of group II phospholipase A2 in serum and colonic mucosa of patients with Crohn's disease of different severity and of appropriate control patients without any inflammatory disease. The activity of the disease was determined by clinical factors (the simple index score) and endoscopic and histological scoring. The mass concentration of group II phospholipase A2 was measured by a time-resolved fluoroimmunoassay. The mass concentrations of group II phospholipase A2 in serum and colonic mucosa were significantly higher both in patients with active and inactive Crohn's disease when compared with controls. There was statistically significant difference in the mass concentration of group II phospholipase A2 in colonic mucosa but not in serum between inactive and active Crohn's disease. The current results indicate that the mass concentration of group II phospholipase A2 is increased in serum and colonic mucosa of patients with Crohn's disease and that the latter is associated with the degree of the inflammatory activity in the intestinal wall. These results support the idea that group II phospholipase A2 is involved in the local and generalised pathological processes of Crohn's disease.
Determination of pH in Human Erythrocytes. Sources of Systematic Error
Authors: Büttner Dietlinde , Büttner Johannes 
Published: October 2004

Abstract
The results of a simultaneous determination of the pH value in erythrocytes with the potentiometric measuring method and the 14C-labelled 5,5-dimethyl-2,4-oxazolidinedione (DMO) method showed a mean method difference of 0.026 pH units. The cause of this discrepancy was assumed to be matrix-inherent liquid-junction potentials in the potentiometric measurement. Taking these into account in the calculation leads to consistent values for the methods investigated. The DMO method proved to be free of systematic errors. Another indication of this is that its mean ratio of extracellular to intracellular H+ ion concentration (He
+/Hi
+) substantially agreed with the distribution ratios of other freely diffusible ions and their pH dependence.
Rapid Molecular Diagnosis of Erythropoietic Protoporphyria among Swiss Patients
Authors: Rüfenacht Urszula B. , Schneider-Yin Xiaoye , Schäfer Beat W. , Taketani Shigeru , Deybach Jean-Charles P. , Minder Elisabeth I. 
Published: October 2004

Abstract
Erythropoietic protoporphyria (EPP) is an autosomal dominant inherited disorder with incomplete penetrance. It is caused by partial deficiency of ferrochelatase, the last enzyme in the heme biosynthetic pathway. Measurement of protoporphyrin concentrations in red cells and feces, although sufficient for diagnosis of symptomatic EPP patients, fails to detect asymptomatic gene carriers. We have developed a molecular diagnostic procedure for rapid and reliable screening of five known mutations in the ferrochelatase gene among Swiss EPP patients in a single denaturing gradient gel electrophoresis (DGGE) gel.
Biochemical Evaluation of Oxidative Stress in Propylthiouracil Treated Hyperthyroid Patients. Effects of Vitamin C Supplementation
Authors: Seven Arzu , Taşan Ertuǧrul , İnci Figen , Hatemi Hüsrev , Burçak Gülden 
Published: October 2004

Abstract
In this study the impact of vitamin C supplementation on oxidative damage as assessed by thiobarbituric acid reactive substances and markers of antioxidant status: namely Cu/Zn superoxide dismutase, glutathione peroxidase, glutathione reductase and glutathione were investigated in 24 hyperthyroid patients under propylthiouracil therapy (3×100 mg/day) for five days and in 15 healthy controls. Ascorbic acid (1000 mg/day) was given as a supplement for 1 month to both the patients and controls during the study period. Heparinised blood samples were taken at the beginning and the end of one month ascorbic acid supplementation.
Comparison of the hyperthyroid patients with the controls revealed higher lipid peroxidation (p<0.001), higher Cu/Zn superoxide dismutase activity (p<0.001), higher glutathione level (p<0.001) and lower glutathione reductase activity (p<0.001).
Vitamin C supplementation to hyperthyroid patients caused significant increases in glutathione concentration (p<0.001) and glutathione peroxidase activity (p<0.001), whereas there were significant decreases in glutathione reductase (p<0.001) and Cu/Zn superoxide dismutase activities (p<0.01). Thiobarbituric acid reactive substances and thiobarbituric acid reactive substances/glutathione ratio were significantly decreased (p<0.01).
Vitamin C supplementation to euthyroid controls caused significant increases in glutathione concentration (p<0.001) and glutathione peroxidase and Cu/Zn superoxide dismutase activities (p<0.001), whereas there was a significant decrease in glutathione reductase (p<0.001). The thiobarbituric acid reactive substances/glutathione ratio was significantly decreased (p<0.05).
Our findings reveal the potentiation of antioxidant status and a relief in oxidative stress in both propylthiouracil treated hyperthyroid patients and controls in response to vitamin C supplementation.
Effect of Aminoguanidine on Erythrocyte Lipid Peroxiclation and Activities of Antioxidant Enzymes in Experimental Diabetes
Authors: Kȩdziora-Kornatowska Kornelia Z. , Luciak Marek , Błaszczyk Jan , Pawlak Wojciech 
Published: October 2004

Abstract
The effect of aminoguanidine (AG) on the malondialdehyde (MDA) concentration and activities of superoxide dismutase (SOD), catalase and glutathione peroxidase (GSH-Px) in erythrocytes of rats with streptozotocin-induced diabetes was studied. Induction of diabetes resulted in an increase of MDA concentration and decreases of SOD and catalase activities after 6 and 12 weeks. GSH-Px activity increased after 6 weeks and returned to control values after 12 weeks. AG administration did not affect body weight, blood glucose level and HbA1c content in diabetic rats but led to a decrease of MDA concentration and SOD and catalase activities after 12 weeks of treatment, with no significant effect after 6 weeks. AG attenuated the GSH-Px increase after 6 weeks but augmented the activity of this enzyme after 12 weeks. These results confirm the presence of oxidative stress in streptozotocin-induced experimental diabetes and point to the beneficial antioxidant effect of AG.
Normalizing Intermethod Free Triiodothyronine Patient Results: Need for Commutable Materials
Authors: Cattozzo Giampaolo , Scarsi Giorgio , Franzini Carlo 
Published: October 2004

Abstract
The aim of this work was to check the suitability of control materials to normalize intermethod results for the measurement of free triiodothyronine in patient sera. In the main experiment, 108 patient sera and 11 commercially available control materials were assayed by a pair of methods. In a confirmatory experiment, two of the control materials and 142 patient sera were assayed with an alternative pair of methods. In the main experiment, the intermethod variability of 6/11 control materials differed significantly from that of patient sera (i. e. control materials were non-commutable). Recalculation of patient results using control materials as calibrators lowered the intermethod difference only if commutable materials were used. The confirmatory experiment demonstrated that the pattern of commutability changed if a different pair of methods was used. We conclude that in the case of free triiodothyronine the commutability of control materials should be tested if they are to be used to normalize patient results obtained by different methods.
Evaluation of a Predictive Kinetic Procedure for the Enzymatic Measurement of Creatinine in Serum
Authors: Yago Martín , Olmos María José , Gómez Trinidad 
Published: October 2004

Abstract
We have evaluated the analytical performance of a predictive kinetic procedure for the enzymatic measurement of serum creatinine in comparison with equilibrium and kinetic fixed-time procedures. The procedure uses commercially available reagents and is based on calculating the total change in absorbance expected if the reaction were to proceed to equilibrium by fitting the initial part of the absorbance-time curve to a three-parameter function by non-linear regression. Total imprecision for different concentrations of creatinine ranges from 1.47 to 1.86% and is significantly better than that obtained for the fixed-time procedure. The results with the predictive procedure are less dependent on creatinine amidohydrolase activity in the reagent, pH of the reagent and temperature of analysis than are the results with the fixed-time procedure. All the procedures are interfered with by bilirubin and ascorbic acid to about the same extent. Recovery and linearity are quite acceptable, and the estimated accuracy is below 2.1%. However, in comparison with the equilibrium procedure, the predictive procedure tends to underestimate creatinine concentrations at values below 100 μmol/l, and the results obtained by the two procedures are not transferable. In conclusion, the predictive approach substantially improves the imprecision but not the specificity of the enzymatic assay of serum creatinine.
Pre-Evaluation and System Optimization of the Elecsys® Thyroid Electrochemiluminescence Immunoassays
Authors: Luppa Peter B. , Reutemann Stefan , Huber Ursula , Hoermann Rudolf , Poertl Stefan , Kraiss Stefan , von Bülow Sabine , Neumeier Dieter 
Published: October 2004

Abstract
We present the results of a pre-evaluation of the thyroid function test free thyroxine, free triiodothyronine and third generation TSH using the Elecsys® electrochemiluminescence immunoassay system. A collaborative field study between the development center of the manufacturer and a clinical chemistry laboratory addressed the reliability and comparability of the new Elecsys® assays to established methods under clinical laboratory conditions using samples from routine in vitro thyroid testing. Preliminary (reference) formulations of the reagents and several electrochemiluminescent pilot models were used for assay measurements, either in the company's research center or in the clinical setting. The new thyroid assays were compared with the respective Enzymun-Test® assays, performed on the ES 300 automated immunoassay analyzer. A WHO standard was used for standardization of TSH, whereas an equilibrium dialysis method was applied for free triiodothyronine. The free thyroxine assay was standardized against the Enzymun-Test® free thyroxine assay, which had previously been calibrated against equilibrium dialysis.
The aim of this field study was to support the optimization of the technology used for Elecsys® in an early stage of development and thereby prepare the ground for the adaptation of the immunoassays to the final Elecsys® 2010 random access analyzer. A subsequent multicenter evaluation demonstrated that the requirements of routine thyroid testing in terms of reliability were fulfilled by the system.
Validation of an Automated Enzyme Immunoassay for Interleukin-6 for Routine Clinical Use
Authors: Fraunberger Peter , Pfeiffer Matthias , Cremer Peter , Holler Ernst , Nagel Dorothea , Dehart Isabelle , Thein Michael , Walli Autar K. , Seidel Dietrich 
Published: October 2004

AbstractSerum levels of Interleukin-6 (IL-6), a proinflammatory cytokine, are increased in early stages of inflammatory diseases such as infection and sepsis. Assay systems which permit its measurement within a few hours and as a single measurement have not been reported so far. We therefore evaluated a now commercially available automated method for IL-6 measurement on the Cobas Core®immunological analyzer (Roche Diagnostic Systems) which enables single IL-6 measurement within about 1 hour. The automated assay correlates well with an established, manual microtiter plate assay (Biosource GmbH) which uses the same antibodies and reagents (r=0.98). Accuracy of the automated method was established by adding known amounts of IL-6 international reference preparation. Recovery of the international standard was in the range of 92–104 %. The automated assay had a precision of singletons below 6% and was linear up to 2800 pg/ml. This automated assay provides a suitable, convenient and time saving method for measurement of IL-6 serum levels in the routine clinical laboratory.
First Experience with the REMEDi HS Urine Benzodiazepine Assay
Authors: Musshoff Frank , Madea Burkhard 
Published: October 2004

Abstract
Ninety eight urine samples were analysed with an immunoassay benzodiazepine kit. A total of 68 urine specimens that were presumptively positive for benzodiazepines were evaluated by the REMEDi HS urine benzodiazepine assay (BIO-RAD, Munich, Germany). Of this number, 53 (78 %) specimens were found by REMEDi to contain one or more benzodiazepines or their metabolites, and 15 (22 %) were found to be negative. From the discordant group of 15 samples, eight were found to be negative using conventional chromatographic procedures (HPLC or GC/MS), while seven contained one or more benzodiazepines or metabolites, each of which were below the individual cut-off level specified by the manufacturer. Additionally 30 urine specimens that were negative for benzodiazepines using immunoassay were also tested by REMEDi. Two samples were found to be positive. These results could not be confirmed by other chromatographic techniques.
The REMEDi HS benzodiazepine assay can be a very useful complementary technique in the clinical/forensic toxicology laboratory, especially for the identification of the parent benzodiazepines administered. The assay provides a rapid result in emergency situations and is useful in confirmation of preliminary positive immunoassay results.
Expert Systems for the Interpretation of Serum Proteins
Authors: Ritchie Robert F. 
Published: October 2004

Abstract
The ready availability of inexpensive desk-top computers
with enormous disk storage has made the practicality of computer assisted
medical interpretive software a reality. There seems little question that these
programs could be of enormous help to physicians. However, there are daunting
problems to their creation, including the lack of standards for clinical
diagnostic precision or accuracy and paucity of helpful literature. As a result,
the final products may be quite different. Little effort has been devoted in the
laboratory to produce programs which could have great benefit in bridging the
gap between laboratorians and clinicians. In a few circumscribed areas where the
interpretation of laboratory measurements have been well studied in relation to
patient demographics and to the final outcome, the impact has been enormous. The
prime example is prenatal diagnosis of neural tube defects, and certain
chromosomal and developmental abnormalities. Viewed as an obstacle by most
people able and willing to attempt to create such programs is the omnipresence
of necessary regulation. A brief overview of the general structure of a program
to assist with the interpretation of serum proteins is given as a model in the
perspective of current knowledge and state of the relevant literature.
Proteome in Perspective
Authors: Hochstrasser Denis F. 
Published: October 2004

AbstractThis review describes briefly proteome science. It explains why proteome science or proteomics emerged only recently and why a shift from genomics to proteomics is occurring. This review further illustrates that proteomics can unravel new domains in nature's complexity. Finally, it demonstrates that proteomics is offering new tools for the study of complex biological or medical problems.
Usefulness of Chromogranin A as a Marker for Detection of Relapses of Carcinoid Tumours
Authors: Pirker Robert A. , Pont Jörg , Pöhnl Rainer , Schütz Wolfgang , Griesmacher Andrea , Müller Matthias M. 
Published: October 2004

Abstract
It is well known that peptide-producing endocrine
tumours cosecrete immunoreactive chromogranin A with their characteristic
hormones. Into this study 187 patients with the diagnosis malignant carcinoids
or other malignancies were entered. Using chromogranin A at a cut-off level of
30.3 U/ml it was possible to discriminate between patients in remission and
patients suffering a relapse with a sensitivity of 91.7% and a specificity of
96.4 %, which may be of important diagnostic value. In our study that lasted
over one year we could clearly show that the measurement of chromogranin A is
impressively superior to 5-hydroxyindoleacetic-acid for detecting a relapse of
carcinoids.
Comparison of Tissue Polypeptide Antigen (TPA) with Cancer Antigen 15-3 (CA 15-3) and Carcino-embryonic Antigen (CEA) in Follow-up of Breast Cancer
Authors: Findeisen Rainer , Albrecht Steffen , Richter Barbara , Deutschmann Kersten , Distler Wolfgang 
Published: October 2004

Abstract
Cancer antigen 15–3 (CA 15–3), carcinoembryonic antigen
(CEA) and tissue polypeptide antigen (TPA) were measured in 679 sera of breast
cancer patients and in 94 sera of women without breast cancer. The tumour
markers were determined using immunoluminometric assays (ILMA). The assays are
characterised by an inter-assay-imprecision and intra-assay-imprecision <4 %.
The breast cancer patients were staged according to the TNM classification stage
0–IV (by UICC) in patient groups with a compatible prognosis. Median and range
of each stage were investigated. The cut-off values (95th and 97.5th percentile
of control group) of CA 15–3, CEA and TPA were determined; specificity,
sensitivity, positive and negative predictive value (PV) and efficiency were
investigated for these cut-off's and the receiver operating characteristic (ROC)
curves were calculated. The differences between control group and stage 0–3 were
shown as non-significant for CA 15–3 and CEA but significant for TPA.
Significant differences were found in stage 4 for all three tumour markers. The
three tumour markers did not have differences in specificity, positive and
negative PV and efficiency. TPA and CA 15–3 demonstrated comparable results in
sensitivity and ROC curve analyses. These results were better than those from
CEA.
Continuous Analysis in Extracorporeally Circulating Blood - A Rat Model Applying Flow-Through Ion-Selective Electrodes for the Measurement of Ca2+, K+, Na+ and pH
Authors: Heidrich Jens P. , Niemeier Anja , Seyfarth Michael 
Published: October 2004

Abstract
A rat model is introduced which enables investigations
in anticoagulated blood with continuous measurements by a flow-through electrode
system. In the present study, a potentiometric ion-selective electrode
(ISE)-system was used for measuring Ca2+, K+,
Na+ and pH in rats. The setup was adjusted to an extracorporeal
blood-volume of 0.750 ml. This permits indirect measurements of the analytes via
a dialysis membrane, with electrical separation of the ISE's and the animal. The
flow-rates of blood and dialysis-solution were adjusted in such a way that water
diffusing from the aqueous dialysis solution into the blood, across the dialysis
membrane, does not alter the haematocrit. Polyethyleneglycol-hirudin was used
for anticoagulation, since it was superior to heparin. The assembly enables
continuous measurements in the living anaesthetized rat over a time period of at
least 3 hours.
Improved Specificity of a New Direct Assay for Urinary Cortisol: Application in Corticoid Treated Patients
Authors: Sapin Rémy , Schlienger Jean Louis , Gasser Françoise , Pradignac Alain , Grucker Daniel 
Published: October 2004

Abstract
Twenty four hours urinary free cortisol (UFC) excretion
has been determined in 35 eucortisolic control patients, in seven of them before
and after tetracosactide (Synacthen®) stimulation and in 18 patients treated by
anti-inflammatory steroids. Results of the new direct Immunotech RIA (DIm) were
compared to those of the INCSTAR RIA kit with (ECA) or without methylene
chloride extraction (DCA). In controls DIm UFC (106.2±45.8 nmol/24h) was
significantly lower than DCA UFC (397±119 nmol/24h) and than ECA UFC (127±49
nmol/24h). After tetracosactide stimulation, median of DCA/DIm ratio decreased
from 3.61 to 1.88 whereas ECA/DIm ratio did not change significantly (1.31 to
1.06). In treated patients most DCA and ECA results were over the upper limit of
controls but only 5 DIm results were increased. DIm assay showed good
specificity and practicability and may be used with benefit in the evaluation of
the adrenal gland function.
Quantitative Automated Particle-Enhanced Immunonephelometric Assay for the Routinary Measurement of Human Cystatin C
Authors: Mussap Michele , Ruzzante Nicoletta , Varagnolo Mariacristina , Plebani Mario 
Published: October 2004

Abstract
Human cystatin C is a low molecular mass protein of
13359 Dalton recently proposed as a new very sensitive marker of changes in
glomerular filtration rate. Serum cystatin C concentration correlates negatively
with glomerular filtration rate as well as or better than creatinine. We
evaluated a recently introduced automated nephelometric immunoassay for cystatin
C in serum or EDTA-plasma samples on the Behring Nephelometer System. The assay
consists of incubating the 100-fold diluted sample for 6 minutes with latex
particles covalently coated with anti-human cystatin C antibodies, and then
quantifying the change of light-scatter produced. Method reproducibility is
satisfactory, the intra-and inter-assay coefficients of variation ranging from
1.58 % to 3.77 % and from 5.6 % to 11.47 % respectively. Rheumatoid factor (≤
1116 IU/ml), bilirubin (≤ 418 μmmol/l), triglycerides (10.47 mmol/l), and
haemoglobin (12 g/l) do not significantly interfere in the assay. No significant
difference was found in cystatin C concentration between serum and EDTA-plasma
samples. Cystatin C is stable in serum samples stored under different conditions
up to one month. This method correlates well (mean difference = −0.536 ± 0.307
mg/l) with another commercially available particle-enhanced turbidimetric
immunoassay. Cystatin C offers better clinical sensitivity than creatinine for
discriminating patients with normal renal function and those with
mild-to-moderate reduction in renal function. This method is suitable for
routine cystatin C measurement, including emergencies.