bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reticulocytes and Reticulated Platelets: Simultaneous Measurement in Whole Blood by Flow Cytometry
Authors: Rapi Stefano , Ermini Angela , Bartolini Laura , Caldini Anna , Del Genovese Alessandra , Miele Anna Rosa , Buggiani Antonio , Fanelli Alessandra 
Published: October 2004

Abstract
Reticulated platelets are a fraction of newly released circulating elements characterized by a residual amount of RNA. It has been suggested that the reticulated platelet count, providing an estimate of thrombopoiesis in the same way as erythrocyte reticulocyte count is a measure of erythropoiesis, may be useful in the study of thrombocytopenic disorders. Reticulated red cells and platelets can be analyzed by flow cytometry using specific stains for nucleic acids such as Thiazole Orange and Auramine-O. The aim of our work was to perform the simultaneous evaluation of reticulated elements in whole blood using a standard flow cytometer and to correlate the results obtained with a dedicated cytometer. A group of 14 patients with abnormal absolute reticulocyte counts (range 1.1–11%) and a group of 41 patients showing a platelet discrimination error when analyzed with a dedicated flow cytometer (Sysmex R1000) were enrolled. Linear amplification of both scatter and fluorescence was used to perform reticulocyte count. A gate was set on platelet dimensions, and logarithmic amplification of scatter and fluorescence was used to count reticulated platelets. A good correlation was obtained both for results of reticulocyte count (r2 = 0.9825) and for reticulated platelets (r2 = 0.8717) between our method and those using dedicated instruments. These data show that reticulated platelet count may be easily introduced in clinical laboratories that routinely perform reticulocyte count by flow cytometry.
Salivary Cortisol - an Alternative to Serum Cortisol Determinations in Dynamic Function Tests
Authors: Aardal-Eriksson Elisabeth , Karlberg Bengt E. , Holm Ann-Charlotte 
Published: October 2004

Abstract
Salivary cortisol was measured as an alternative to serum cortisol as a marker for adrenocortical function following insulin tolerance test, corticotropin-releasing-hormone stimulation and adreno-corticotrophic hormone stimulation. During insulin tolerance test and corticotropin-releasing-hormone stimulation adreno-corticotrophic hormone was also measured. The tests were performed on healthy control subjects as well as on patients under investigation for various disturbances in the hypothalamic-pituitary-adrenocortical axis (insulin tolerance test: 3 controls on two occasions and 14 patients; corticotropin-releasing-hormone stimulation: 4 controls and 18 patients; adreno-corticotrophic hormone stimulation: 6 controls and 10 patients). Five patients underwent both insulin tolerance test and corticotropin-releasing-hormone stimulation. Using criteria for adequate cortisol response in serum, the patients were classified as good or poor responders. In 42 of the 45 tests performed the same conclusion as to cortisol status was drawn when based on serum and salivary cortisol responses. In healthy subjects and good responders the mean cortisol relative increase was greater in saliva than in serum in all three tests (p < 0.05). Characteristic of the results for the insulin tolerance test was a significant initial mean decrease (p < 0.05), not found in serum, and the highest observed salivary cortisol value was delayed for at least 30 minutes compared to that in serum. Plasma adreno-corticotrophic hormone correlated significantly with the cortisol concentrations determined 15 minutes later in serum (r = 0.54–0.64) and in saliva (r = 0.76–0.85). The more pronounced cortisol response in saliva than in serum and its closer correlation with adreno-corticotrophic hormone offer advantages over serum cortisol, suggesting salivary cortisol measurement may be used as an alternative parameter in dynamic endocrine tets.
A Time-Resolved Fluorescence Immunoassay for the Measurement of Testosterone in Saliva: Monitoring of Testosterone Replacement Therapy with Testosterone Buciclate
Authors: Tschöp Matthias , Behre Hermann M. , Nieschlag Eberhard , Dressendörfer Regina A. , Strasburger Christian J. 
Published: October 2004

Abstract
Monitoring of testosterone replacement therapy requires a reliable method for testosterone measurement. Determination of salivary testosterone, which reflects the hormone's biologically active plasma fraction, is a superior technique for this purpose. The aim of the present study was to establish a new sensitive time-resolved fluorescence immunoassay for the accurate measurement of testosterone levels in saliva and to validate it by monitoring testosterone replacement therapy in eight hypogonadal men.
A clinical phase I-study with the new ester testosterone buciclate was performed to search for new testosterone preparations to produce constant serum levels in the therapy of male hypogonadism. After two control examinations eight male patients with primary hypogonadism were randomly assigned to two treatment groups (n= 2×4) and given single doses of either 200 mg (group I) or 600 mg (group II) testosterone buciclate intramuscularly. Saliva and blood samples were obtained 1, 2, 3, 5 and 7 days post injection and then weekly for three months.
The time-resolved fluorescence immunoassay for salivary testosterone shows a detection limit of 16 pmol/l, an intra-assay CV of 8.9 % (at a testosterone concentration of 302 pmol/l), an inter-assay CV of 8.7 % (at a testosterone concentration of 305 pmol/l) and a good correlation with an established radioimmunsassay of r=0.89. The sample volume required by this method is only 180 μl for extraction and duplicate determination. The assay procedure requires no more than three hours.
In group I (200 mg) testosterone did not increase to normal levels either in saliva or in serum. However, in group II, androgen levels increased significantly and were maintained in the normal range for up to 12 weeks with maximal salivary testosterone levels of 303 ±18 pmol/l (mean ±SE) and maximal testosterone levels of 13.1 ±0.9 nmol/l (mean±SE) in serum in study week 6 and 7.
The time-resolved fluorescence immunoassay for salivary testosterone provides a useful tool for monitoring androgen status in men and women and is well suited for the follow-up of testosterone replacement therapy on an outpatient basis. The long-acting ester testosterone buciclate is a promising agent for substitution therapy of male hypogonadism and in combination with testosterone monitoring in saliva offers an interesting new perspective for male contraception.
Neuron-Specific Enolase: Reference Values in Cord Blood
Authors: Kintzel Kathrin , Sonntag Josef , Strauß Evelyn , Obladen Michael 
Published: October 2004

AbstractWith foetal sonography prenatal detection of tumours has become more frequent. To evaluate and treat these infants it is necessary to identify the tumour postnatally. Elevated neuron-specific enolase is a biochemical marker of neuroblastoma. Since conditions during birth may influence neuron-specific enolase concentration in foetal serum, specific reference values in cord blood are required. Cord blood samples were taken from 192 healthy term newborns and concentration of neuron-specific enolase was measured by enzyme immunoassay (EIA). Median neuron-specific enolase concentration in the reference group was 8.0 μg/l and the 5th–95th percentiles were 4.8–19.4 μg/l. No differences between male and female newborns were detected (p = 0.13).Measurement of neuron-specific enoloase in cord blood, in comparison with our reference values, offers an early postnatal possibility of confirming the diagnosis of neuroblastoma.
Developments in Quantitative PCR
Authors: Orlando Claudio , Pinzani Pamela , Pazzagli Mario 
Published: October 2004

AbstractIn recent years the growing interest in quantitative applications of the polymerase chain reaction (PCR) has favoured the development of a large number of assay procedures suitable for this purpose. In this paper we review some basic principles of quantitative PCR and in particular the role of reference materials and calibrators and the different strategies adopted for nucleic acid quantification. We focus on two methodological approaches for quantitative PCR in this review: competitive PCR and real-time quantitative PCR based on the use of fluorogenic probes. The first is one of the most common methods of quantitative PCR and we discuss the structure of the competitors and the various assay procedures. The second section is dedicated to a recent promising technology for quantitative PCR in which the use of fluorogenic probes and dedicated instrumentation allows the development of homogeneous methods. Assay performance of these methods in terms of practicability and reliability indicates that these kinds of technologies will have a widespread use in the clinical laboratory in the near future.
Endemic Nephropathy in Croatia
Authors: Čvorišćec Dubravka , Čeović Stjepan , Boršo Gordana , Rukavina Ana Stavljenić 
Published: October 2004

Abstract
Endemic nephropathy is a chronic renal disease with a high prevalence in a geographically limited area of Croatia. It has also been recorded in some parts of Bosnia, Serbia, Bulgaria and Romania. Despite numerous studies conducted to date, the etiology of this disease has not been clarified. Pathological studies of the kidney in the early stage of endemic nephropathy have shown renal tubules to be the primary sites of the pathologic process with an interstitial tissue reaction, whereas glomerular alterations are of a secondary character. Tubulointerstitial lesions can thus account for the symptoms of the disease, i.e. tubular proteinuria and reduced urine concentration capacity and urine acidification. Also, an increased incidence of malignant tumours of the urinary tract was found in the same geographic area.
Recombinant Human Heart-Type Fatty Acid-Binding Protein as Standard in Immunochemical Assays
Authors: Schreiber Andrea , Specht Bernfried , Pelsers Maurice M. A. L. , Glatz Jan F. C. , Börchers Torsten , Spener Friedrich 
Published: October 2004

Abstract
Cytoplasmic heart-type fatty acid-binding protein has recently gained much attention in clinical diagnosis as a very early marker of acute myocardial infarction. Immunoassays have been developed for determination of this protein in plasma and urine samples. In the present study it is shown that those types of fatty acid-binding proteins which are abundant in tissues other than heart and muscle do not interfere with immunochemical determination of heart-type fatty acid-binding protein. To provide sufficient protein of consistent quality as standard in these immunoassays, human heart-type fatty acid-binding protein was cloned, expressd in Escherichia coli and purified to homogeneity. For quantitation of the recombinant protein its extinction coefficient was determined. Comparison of the recombinant and tissue-derived proteins by a variety of methods revealed both proteins to show similar kinetic as well as equilibrium constants with respect to two monoclonal antibodies currently applied in immunochemical detection of heart-type fatty acid-binding protein. Both preparations were indistiguishable in sandwich-ELISA and immunosensor measurements. A high stability of the recombinant protein was proven by ELISA measurements during storage and several freeze and thaw cycles. Thus, recombinant and tissue-derived heart-type fatty acid-binding proteins are immunochemically equivalent. The recombinant human heart-type fatty acid-binding protein is now available as standard for immunoassays.
Sialic Acid, Transketolase and Na+, K+, ATPase in Patients with Rheumatoid Arthritis
Authors: Kızıltunç Ahmet , Çoǧalgil Şirzat , Uǧur Mahir , Avcı Bahattin , Akçay Fatih 
Published: October 2004

Abstract
We studied transketolase activity of red blood cell hemolysates, and Na+, K+, ATPase activity and sialic acid concentration in red blood cell membranes from 52 patients with rheumatoid arthritis and 24 control subjects. Decreased red blood cell membrane Na+, K+, ATPase activity and sialic acid concentration and decreased transketolase in red blood cell hemolysates were observed in rheumatoid arthritis patients compared with control subjects (p < 0.001). Erythrocyte sedimentation rate and C-reactive protein values were increased in rheumatoid arthritis patients compared with control subjects (p < 0.0001). Significant correlations between sialic acid and Na+, K+, ATPase (r = 0.65, p < 0.001) and between sialic acid and transketolase (r = 0.58, p < 0.001) were observed. Erythrocyte sedimentation rate and C-reactive protein levels did not correlate with Na+, K+, ATPase activity or with sialic acid or transketolase in rheumatoid arthritis patients.
These data show that decreases in Na+, K+, ATPase, and transketolase activities and sialic acid concentration are present in rheumatoid arthritis patients, and that the decrease in Na+, K+, ATPase and transketolase activities in rheumatoid arthritis might be due to decreased sialic acid.
Quantitation and Enzymatic Activity of the Alkaline Protease from Pseudomonas aeruginosa in Culture Supernatants from Clinical Strains
Authors: Louis Dominique , Sorlier Pierre , Wallach Jean 
Published: October 2004

Abstract
Alkaline protease from Pseudomonas aeruginosa (E.C. 3.4.24.40), also called pseudomonal serralysin, plays an important role in the infection bacterial process. The alkaline protease concentration and activity in the culture supernatants of 23 Pseudomonas aeruginosa strains from patients suffering from cystic fibrosis were determined by using an ELISA procedure and a specific enzymatic activity test. No correlation was demonstrated between the activity and the concentration of alkaline protease. This could be explained by the presence of an inactive precursor and a partial hydrolysis of the enzyme, confirmed by SDS-PAGE and Western blotting in the supernatants. The activity test is the only one allowing a quantification of the presence of an active form of alkaline protease.
Preparation of a Candidate Primary Reference Material for the International Standardisation of HbA1c Determinations
Authors: Finke Andreas , Kobold Uwe , Hoelzel Wieland , Weykamp Cas , Miedema Kor , Jeppsson Jan-Olof 
Published: October 2004

Abstract
We prepared a candidate primary reference material for the forthcoming international standardisation of β-N-terminal glycated hemoglobin A measurements. It consists of well-defined mixtures of purified β-N-terminal glycated hemoglobin A and non-glycated hemoglobin A.
First, β-N-terminal glycated hemoglobin A and non-glycated hemoglobin A were isolated, purified to homogeneity, and characterised. The techniques used were cation exchange and affinity chromatography for the purification, and high performance liquid chromatography, capillary isoelectric focusing, electrospray ionisation mass spectrometry, and peptide mapping for the characterisation. Hemoglobins from blood of healthy, non-diabetic volunteers were obtained with a purity of >99.5% for non-glycated hemoglobin A and of >98.5% for β-N-terminal glycated hemoglobin A. However, results from peptide mapping indicate that the β-N-terminal glycated hemoglobin A preparations still contain some non-β-N-terminal glycated hemoglobins, co-eluting with β-N-terminal glycated hemoglobin A. The exact content of β-N-terminal glycated hemoglobin A in these preparations could be determined by a procedure consisting of standard addition, enzymatic cleavage and quantification of the resulting β-Nterminal peptides to be in the range from 95–97.5%.
Since the β-N-terminal glycated hemoglobin A and non-glycated hemoglobin A content could be exactly determined in the materials prepared, mixtures of both components could be successfully used to calibrate the candidate reference methods.
Urinary α1-Microglobulin Detects Uropathy. A Prospective Study in 483 Urological Patients
Authors: Everaert Karel , Delanghe Joris , Wiele Christophe Vande , Hoebeke Piet , Dierckx Rudy A. , Clarysse Bart , Lameire Norbert , Oosterlinck Willem 
Published: October 2004

Abstract
Purpose: The aim of the study was to evaluate prospectively urinary α1-microglobulin as a marker of proximal tubular damage following acute pyelonephritis and outflow disease of the upper urinary tract in a urological population with minimal exclusion criteria. We also measured the urinary γ-glutamyltransferase activity, urinary albumin, urinary and serum creatinine, serum IgA and serum α1-microglobulin.
Patients and methods: We studied 483 urological patients (age: 1 to 92 years, 297 men, 186 women) excluding patients receiving nephrotoxic drugs, or suffering from type 1 diabetes or renal diseases. There were 141 patients with urinary tract infection but no fever, 36 patients with high fever of non-renal origin, 51 patients with acute pyelonephritis and 156 patients with outflow disease of the upper tract, and 99 patients were incluced in the reference population.
Results: For acute pyelonephritis, vesico-ureteral reflux, and ureteral obstruction, urinary α1-microglobulin had a sensitivity of 94%, 90% and 63% respectively and a specificity of 67%, 77% and 76%. The area under the curve of the receiver operator characteristic curve was significantly (p < 0.001) higher for urinary α1-microglobulin than for albumin or γ-glutamyltransferase activity. Unexpected positive results were found in acute prostatitis. The urinary α1-microglobulin was the only parameter which differentiated between acute prostatitis and pyelonephritis (p < 0.001). Creatinine clearance or age had little and gender had no influence on the urinary excretion of α1-microglobulin. Urine production rate significantly increases the urinary α1-microglobulin/creatinine ratio.
Conclusion: Our results suggest that the urinary α1-microglobulin/creatinine ratio is a diagnostically useful marker of tubular damage in acute pyelonephritis and vesico-ureteral reflux in the urological population. Following renal colic and chronic ureteral obstruction, a significant increase in urinary α1-microglobulin excretion was observed.
Short-Term Variability in the Concentration of Serum Interleukin-6 and Its Soluble Receptor in Subjectively Healthy Persons
Authors: Dugué Benoit , Leppänen Esa 
Published: October 2004

Abstract
The effects of the time of the day and breakfast on the outcome of interleukin-6 and its soluble receptor in serum were studied on 22 subjectively healthy volunteers. We collected blood specimens at 8.00 a.m. after an overnight fast, at 9.30 a.m. after usual breakfast, and at 11.30 a.m. A second group of volunteers (n = 20) was studied during the evening. We observed a significant decrease in the concentration of interleukin-6 after breakfast. This suggests that for assay of this analyte it is preferable to collect specimens after overnight fast. No changes were observed in the concentrations of interleukin-6 soluble receptor. Weak, but significant negative correlations were found between the age of the volunteers and the concentrations of interleukin-6 soluble receptor and between age and the ratio interleukin-6 soluble receptor/interleukin-6. The concentrations of interleukin-6 were positively and significantly correlated with age.
The within-subject variablity was 30 % for interleukin-6,13% for its receptor, and 33.1% for the ratio interleukin-6 soluble receptor/interleukin-6. The between-subject variability was 43.7 % for interleukin-6, 22.2% for its receptor, and 60.2 % for the ratio interleukin-6 soluble receptor/interleukin-6. The indices of individuality (ratio within-subject variability/between-subject variability) were calculated and found to be 0.69, 0.60, and 0.55 for interleukin-6, its soluble receptor, and the ratio interleukin-6 soluble receptor/interleukin-6, respectively. The implications of these indices with the use of health-related reference values is discussed.
Pediatric Reference Intervals for 34 Biochemical Analytes in Urban School Children and Adolescents
Authors: Jagarinec Nada , Flegar-Meštrić Zlata , Šurina Branka , Vrhovski-Hebrang Danijela , Preden-Kereković Vladimira 
Published: October 2004

AbstractConcentrations of 34 biochemical constituents of sera were determined on 998 randomly selected urban school children and adolescents aged 8–18 years from Zagreb, Croatia. Reference intervals were obtained by using non-parametric methods to estimate 2.5 and 97.5 percentiles of distribution as upper and lower normal reference intervals, according to the IFCC recommendations. These were compared to reference intervals in the healthy adult population, aged 20–30 years from the same geographical area. Serum glucose, potassium, sodium, chloride, magnesium, iron, zinc, total serum proteins and electrophoretic fractions, and amylase, did not show age or sex differences; total serum bilirubin, total calcium, phosphate, high density lipoprotein cholesterol, total iron binding capacity, unsaturated iron binding capacity, copper, aspartate aminotransferase, alkaline phosphatase, cholinesterase, creatine kinase, and lactate dehydrogenase had higher reference intervals than the adult population. Urea, creatinine, urate, alanine aminotransferase, γ-glutamyltransferase, total cholesterol and low density lipoprotein-cholesterol, and triglycerides had lower reference intervals than the adult population.
Progress in Immunoassay Technology
Authors: Price Christopher P. 
Published: October 2004

Abstract
Immunoassay is now the most
widely used analytical technique in laboratory medicine embracing a vast
repertoire of analytes and delivered through an increasingly diverse range of
devices. This explosion of analytical techniques is complemented by an
increasing knowledge base on the antigen antibody reaction that is being used to
explore new and improved methodologies.
Our knowledge of the molecular
chemistry of the antigen antibody reaction coupled with the molecular biology of
immunoglobulin expression has led to the development of antibody and
antibody-like molecules with enhanced specificity, and reaction kinetics. These
developments include novel fusion proteins, antibody mimics and antibodies that
recognise antigen antibody complexes.
The advances in the chemistry of
the analytical systems are matched by the design of delivery vehicles: on the
one hand the automated analyser that facilitates the analysis of large numbers
of samples and on the other, the encapsulated, miniaturised device that enables
an immunoassay to be performed at the point of care.
Engineering of an Anti-Steroid Antibody: Amino Acid Substitutions Change Antibody Fine Specificity from Cortisol Estradiol
Authors: Chames Patrick , Baty Daniel 
Published: October 2004

AbstractImmunoassays are widely used for determination of the concentration of steroid hormones. However, obtaining specific anti-steroid monoclonal antibodies remains difficult. We used antibody engineering and phage display methods to change the specificity of an anti-cortisol monoclonal antibody towards estradiol. This work demonstrates that production of recombinant antibodies may be a valuable way of obtaining the high-specificity antibodies required for steroid immunoassays.