bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of Non-α1-Antichymotrypsin-complexed Prostate-specific Antigen as an Indirect Measurement of Free Prostate-specific Antigen: Analytical Performance and Diagnostic Accuracy
Authors: Wesseling Sebastian , Stephan Carsten , Semjonow Axel , Lein Michael , Brux Brigitte , Sinha Pranav , Loening Stefan A , Jung Klaus 
Published: February 2004

Abstract
Background: A new assay measures prostate-specific antigen (PSA) not complexed to α1-antichymotrypsin (nACT-PSA) after removing PSA complexed to ACT by use of anti-ACT antibodies. We evaluated nACT-PSA and its ratio to total PSA (tPSA) as alternatives to free PSA (fPSA) and its ratio to tPSA in differentiating prostate cancer (PCa) and benign prostatic hyperplasia (BPH) in patients with tPSA of 2–20 μg/L.
Methods: PSA in serum of 183 untreated patients with PCa and 132 patients with BPH was measured retrospectively on the chemiluminescence immunoassay analyzer LIAISON® (Byk-Sangtec Diagnostica) with the LIAISON tPSA and LIAISON fPSA assays. The nACT-PSA fraction was determined with a prototype assay measuring the residual PSA after precipitation of ACT-PSA with an ACT-precipitating reagent.
Results:nACT-PSA was higher than fPSA in samples with fPSA concentrations &lt;1 μg/L but lower in samples with &gt;1 μg/L fPSA. The median ratios of fPSA/tPSA and of nACT-PSA/tPSA were significantly different between patients with BPH and PCa (19.4% vs 12.2% and 17.4% vs 13.0%, respectively). Within the tPSA ranges tested (2–20, 2–10, and 4–10 μg/L), areas under the ROC curves for the fPSA/tPSA ratios were significantly larger than those for nACT-PSA/tPSA. In the tPSA ranges &lt;10 μg/L, the areas under the ROC curves for fPSA/tPSA were significantly larger than those for tPSA, whereas the areas for nACT-PSA/tPSA were not. At decision limits for 95% sensitivity and specificity, both ratios significantly increased specificity and sensitivity, respectively, compared with tPSA, but the fPSA/tPSA ratio showed higher values.
Conclusions: nACT-PSA and its ratio to tPSA provide lower diagnostic sensitivity and specificity than fPSA/tPSA. The fPSA/tPSA ratio represents the state-of-the-art method for differentiating between PCa and BPH.
Plasma Total Cysteine, Mortality, and Cardiovascular Disease Hospitalizations: The Hordaland Homocysteine Study
Authors: El-Khairy Lina , Vollset Stein E , Refsum Helga , Ueland Per M 
Published: February 2004

AbstractBackground: We have previously reported a positive association between tHcy and mortality and cardiovascular disease (CVD) hospitalizations in the Hordaland Homocysteine Study cohort. Using the same data set, we assessed the relationship between plasma total cysteine (tCys) and mortality from all causes and from cardiovascular and noncardiovascular conditions, and the association between tCys and the risk of hospitalizations from CVD.Methods: We measured plasma tCys in blood samples from 12 595 men and women 40–42 years of age and from 4766 men and women 65–67 years of age, collected as part of the Hordaland Homocysteine Study in the year 1992–1993. Follow-up data on mortality were collected through 1999. Data on CVD hospitalizations were collected from hospital records up to May 31, 1998.Results: After a follow-up time of 6.6–7.6 years, there were a total of 610 deaths, of which 243 were cardiovascular deaths and 367 were noncardiovascular deaths. There was no association between tCys and all-cause, cardiovascular, or noncardiovascular mortality. When we used tCys values &lt;247.6 μmol/L (lowest quartile) as the reference category, the adjusted mortality ratio (MR) for all-cause mortality at tCys concentrations of 247.6–270.79, 270.8–295.79, and ≥295.8 μmol/L (highest quartile) were 1.0, 0.9, and 1.0, respectively. The adjusted MRs for cardiovascular mortality were 1.0, 1.1, and 1.1, respectively. There were no associations between tCys and 1275 CVD hospitalizations, except that tCys was significantly associated with hospitalizations from coronary artery bypass grafting.Conclusion: Plasma tCys is not associated with mortality or CVD hospitalizations.
Detection of Recombinant Human Erythropoietin in Urine by Isoelectric Focusing
Authors: Breidbach Andreas , Catlin Don H , Green Gary A , Tregub Inna , Truong Henry , Gorzek Jeffrey 
Published: February 2004

AbstractBackground: Doping with erythropoietic proteins such as recombinant human erythropoietin (rHuEPO) and darbepoetin alfa is a serious issue in sport. There is little information on the time course of detection of rHuEPO in urine and on methods to evaluate electrophoresis-based data.Methods: We used a recently described isoelectric focusing method for detecting rHuEPO and endogenous EPO in urine obtained from individuals treated with placebo or epoetin alfa. The latter was administered subcutaneously at 50 IU/kg on days 0, 2, 4, 7, 9, 11, 14, 16, and 18. Blood and urine samples were collected during the morning of study days −3, 0, 2, 4, 7, 9, 11, 14, 16, and 18 and on days 2, 3, 4, and 7 postadministration. We developed visual and numerical (two-band ratio) techniques to evaluate the electropherograms for the presence of rHuEPO.Results: Compared with the placebo group, the epoetin alfa-treated group responded with increases in hematocrit, reticulocytes, macrocytes, serum EPO, and serum soluble transferrin receptor. The electropherograms showed that the pattern of bands arising from urinary rHuEPO is different from that of endogenous urinary EPO. Both the two-band ratio and the visual technique detected rHuEPO in all 14 epoetin alfa-treated individuals 3 days after the last dose. On the 7th day after the last dose, both techniques detected rHuEPO in approximately one-half of the participants. rHuEPO was not detected in the placebo-treated individuals.Conclusions: The isoelectric focusing method detects rHuEPO in most urine samples collected 3 days after nine doses of epoetin alfa. The numerical two-band ratio was equivalent to a visual method for detecting rHuEPO in urine.
Time-resolved Fluorometric Assay for Detection of Autoantibodies to Glutamic Acid Decarboxylase (GAD65)
Authors: Ankelo Matti , Westerlund-Karlsson Annette , Ilonen Jorma , Knip Mikael , Savola Kaisa , Kankaanpää Pasi , Meriö Liisa , Siitari Harri , Hinkkanen Ari 
Published: February 2004

Abstract
Background: Type 1 diabetes mellitus results from destruction of the pancreatic insulin-producing beta cells by a chronic autoimmune process. Methods are needed for the detection of circulating autoantibodies to glutamic acid decarboxylase (GAD65), a major marker of this process.
Methods: Streptavidin-coated microtiter plates were incubated with biotinylated GAD65, and after incubation with serum samples from patients with type 1 diabetes mellitus and control individuals, europium-labeled GAD65 was added. After washing steps, the delayed fluorescence was measured in duplicate in a fluorometer. Samples collected from 100 patients with newly diagnosed type 1 diabetes mellitus and 100 healthy controls were measured by the new assay and by a radiobinding assay.
Results: The detection limit of the new assay was 1.49 WHO units/mL, the calibration curve was linear to 4 140 WHO units/mL, and no hook effect was observed up to 41 400 WHO units/mL. The intraassay CV was 2.1–6.3% over the calibration range. For patient serum samples, the intraassay, interassay, and total CVs were 5.4–7.0%, 9.8–13%, and 12–14%, respectively. Compared with conventional radioimmunologic methods, the analytical range was broader and the analysis time required to perform the measurements was shorter. At a cutoff with 99% specificity, the new assay and the radiobinding assay were positive in 71 and 67 patients, respectively.
Conclusions: The new assay provides a rapid and sensitive nonradioactive method applicable for large-scale screening for beta-cell autoimmunity. It has a broad linear analytical range, is easy to perform and automate, and has sensitivity and specificity comparable to those for the conventional radioisotope assay.
Monitoring Blood Glucose Changes in Cutaneous Tissue by Temperature-modulated Localized Reflectance Measurements
Authors: Yeh Shu-jen , Hanna Charles F , Khalil Omar S 
Published: February 2004

AbstractBackground: Most proposed noninvasive methods for glucose measurements do not consider the physiologic response of the body to changes in glucose concentration. Rather than consider the body as an inert matrix for the purpose of glucose measurement, we exploited the possibility that noninvasive measurements of glucose can be approached by investigating their effects on the skin’s thermo-optical response.Methods: Glucose concentrations in humans were correlated with temperature-modulated localized reflectance signals at wavelengths between 590 and 935 nm, which do not correspond to any near-infrared glucose absorption wavelengths. Optical signal was collected while skin temperature was modulated between 22 and 38 °C over 2 h to generate a periodic set of cutaneous vasoconstricting and vasodilating events, as well as a periodic change in skin light scattering. The method was tested in a series of modified meal tolerance tests involving carbohydrate-rich meals and no-meal or high-protein/no-carbohydrate meals.Results: The optical data correlated with glucose values. Changes in glucose concentrations resulting from a carbohydrate-rich meal were predicted with a model based on a carbohydrate-meal calibration run. For diabetic individuals, glucose concentrations were predicted with a standard error of prediction &lt;1.5 mmol/L and a prediction correlation coefficient 0.73 in 80% of the cases. There were run-to-run differences in predicted glucose concentrations. Non-carbohydrate meals showed a high degree of scatter when predicted by a carbohydrate meal calibration model.Conclusions: Blood glucose concentrations alter thermally modulated optical signals, presumably through physiologic and physical effects. Temperature changes drive cutaneous vascular and refractive index responses in a way that mimics the effect of changes in glucose concentration. Run-to-run differences are attributable to site-to-site structural differences.
Preanalytical Factors That Influence the Abbott TDx Fetal Lung Maturity II Assay
Authors: Grenache David G , Parvin Curtis A , Gronowski Ann M 
Published: February 2004

Abstract
Background: The TDx Fetal Lung Maturity II (FLM II) assay uses amniotic fluid to assess lung maturity of the unborn infant. We investigated common preanalytical factors that influence FLM results, including centrifugation, sample storage, and contamination by whole blood.
Methods: We tested 18 specimens after centrifugation and after resuspension by vortex-mixing. We also analyzed 23 specimens stored at −20 °C for up to 448 days and then thawed (duplicate measurements), 20 specimens stored at 4 °C, and 24 specimens stored at room temperature. In addition, we evaluated the effects of whole blood diluted into 19 different specimens.
Results: Centrifugation significantly decreased FLM II results from baseline (P &lt;0.0001), and resuspension returned results to baseline values (P = 0.286). Storage at −20 °C produced highly variable results that demonstrated a nonsignificant negative trend associated with storage time. Specimens were stable for 24 h when stored at 4 °C and 16 h at room temperature. Blood contamination produced significantly positive differences in results only in specimens with baseline values ≤39 mg/g with a 5.8 mg/g increase in FLM II for every 0.1 × 1012/L increase in the erythrocyte count (slope = 58.4).
Conclusions: Resuspension of centrifuged specimens produces clinically valid FLM II results. Results from specimens stored at −20 °C can be highly variable and decrease over time. Results from specimens stored at 4 °C and at room temperature are stable for 24 and 16 h, respectively. Blood contamination up to 0.03 × 1012 erythrocytes/L is acceptable for FLM II analysis.
Hydroxytyrosol Disposition in Humans
Authors: Miro-Casas Elisabet , Covas Maria-Isabel , Farre Magi , Fito Montserrat , Ortuño Jordi , Weinbrenner Tanja , Roset Pere , de la Torre Rafael 
Published: February 2004

Abstract
Background: Animal and in vitro studies suggest that phenolic compounds in virgin olive oil are effective antioxidants. In animal and in vitro studies, hydroxytyrosol and its metabolites have been shown to be strong antioxidants. One of the prerequisites to assess their in vivo physiologic significance is to determine their presence in human plasma.
Methods: We developed an analytical method for both hydroxytyrosol and 3-O-methyl-hydroxytyrosol in plasma. The administered dose of phenolic compounds was estimated from methanolic extracts of virgin olive oil after subjecting them to different hydrolytic treatments. Plasma and urine samples were collected from 0 to 12 h before and after 25 mL of virgin olive oil intake, a dose close to that used as daily intake in Mediterranean countries. Samples were analyzed by capillary gas chromatography–mass spectrometry before and after being subjected to acidic and enzymatic hydrolytic treatments.
Results: Calibration curves were linear (r &gt;0.99). Analytical recoveries were 42–60%. Limits of quantification were &lt;1.5 mg/L. Plasma hydroxytyrosol and 3-O-methyl-hydroxytyrosol increased as a response to virgin olive oil administration, reaching maximum concentrations at 32 and 53 min, respectively (P &lt;0.001 for quadratic trend). The estimated hydroxytyrosol elimination half-life was 2.43 h. Free forms of these phenolic compounds were not detected in plasma samples.
Conclusions: The proposed analytical method permits quantification of hydroxytyrosol and 3-O-methyl-hydroxytyrosol in plasma after real-life doses of virgin olive oil. From our results, ∼98% of hydroxytyrosol appears to be present in plasma and urine in conjugated forms, mainly glucuronoconjugates, suggesting extensive first-pass intestinal/hepatic metabolism of the ingested hydroxytyrosol.
Biological Threat Detection via Host Gene Expression Profiling
Authors: Lin Baochuan , Vahey Maryanne T , Thach Dzung , Stenger David A , Pancrazio Joseph J 
Published: February 2004

Abstract
With the increased threat posed by biological weapons, detection techniques for biothreat pathogens are critically needed to monitor and assess the severity of the illness once exposure has occurred. Current approaches for detecting biological threats are either time-consuming or highly specific but provide little information regarding pathogenicity. Genotyping of pathogens by PCR provides a fast and definitive means for identifying pathogens, but reliance on pathogen genotypic endpoints has several limitations. Current progress in DNA microarrays technology provides an alternative way to address the issues faced by traditional detection systems through host gene expression profiles of peripheral blood cells. We discuss the advantages and critical issues facing the use of host gene expression profiling for biological threat detection.
Linked Linear Amplification for Simultaneous Analysis of the Two Most Common Hemochromatosis Mutations
Authors: Killeen Anthony A , Breneman John W , Carillo Arlene R , Liu Jason , Hixson Craig S 
Published: February 2004

Abstract
Background: Two mutations in HFE, G845A (amino acid substitution C282Y) and C187G (H63D), are associated with hereditary hemochromatosis. We developed and validated a novel method, linked linear amplification (LLA), for detection of these two mutations.
Methods: Two segments of HFE were amplified by a multiplex LLA reaction that generated biotinylated LLA products. Aliquots of the multiplex LLA reaction were captured in microwells by hybridization to immobilized allele-specific oligonucleotides (ASOs). One wild-type and one mutant ASO represented the DNA sequence at each of the two mutation sites. Hybridization was detected by a streptavidin–horseradish peroxidase-based colorimetric method. Genotypes obtained by LLA and PCR-restriction fragment length polymorphism (PCR-RFLP) methods for 320 individuals were compared.
Results: The amplified samples included the following genotypes as determined by PCR-RFLP: wild-type 282 and 63 codons (n = 105), C282Y homozygous mutant (n = 54), C282Y heterozygous (n = 52), H63D homozygous mutant (n = 17), H63D heterozygous (n = 59), and compound H63D and C282Y heterozygous mutant (n = 33). There was complete concordance between the results obtained by LLA and those obtained by PCR-RFLP analysis. The presence of another HFE mutation, A193T (encoding S65C), did not interfere with genotyping at codon 63.
Conclusions: LLA provides a reliable method to detect the common mutations in HFE that cause hereditary hemochromatosis.
DNA Integrity as a Potential Marker for Stool-based Detection of Colorectal Cancer
Authors: Boynton Kevin A , Summerhayes Ian C , Ahlquist David A , Shuber Anthony P 
Published: February 2004

AbstractBackground: Molecular genetic analysis of DNA in patient stools has been proposed for screening of colorectal cancer (CRC). Because nonapoptotic cells shed from tumors may contain DNA that is less degraded than DNA fragments from healthy colonic mucosa, our aim was to show that DNA fragments isolated from stools of patients with CRC had higher integrity than DNA isolated from stools of patients with healthy colonic mucosa.Methods: We purified DNA from the stools of a colonoscopy-negative control group and patients with CRC and examined the relationship between long DNA fragments and clinical status by determining stool DNA integrity, using oligonucleotide-based hybrid captures with specific target sequences in increasingly long PCR reactions (200 bp, 400 bp, 800 bp, 1.3 kb, 1.8 kb, 24 kb). DNA fragments obtained from CRC patients were compared with fragments obtained from colonoscopy-negative individuals for length and/or integrity.Results: DNA fragments isolated from CRC patients were of higher molecular weight (&gt;18 bands detected of a total of 24 possible bands) than fragments isolated from fecal DNA of the colonoscopy-negative control group.Conclusions: The presence of long DNA fragments in stool is associated with CRC and may be related to disease-associated differences in the regulation of proliferation and apoptosis. An assay of fecal DNA integrity may be a useful biomarker for the detection of CRC.
Screening and Quantification of Multiple Chromosome Translocations in Human Leukemia
Authors: Shi Run Zhang , Morrissey Joseph M , Rowley Janet D 
Published: February 2004

Abstract
Background: Characterization of fusion gene transcripts in leukemia that result from chromosome translocations provides valuable information regarding appropriate treatment and prognosis. However, screening for multiple fusion gene transcripts is difficult with conventional PCR and state-of-the-art real-time PCR and high-density microarrays.
Methods: We developed a multiplex reverse transcription-PCR (RT-PCR) assay for screening and quantification of fusion gene transcripts in human leukemia cells. Chimeric primers were used that contained gene-specific and universal sequences. PCR amplification of fusion and control gene transcripts was achieved with use of an excess of universal primers to allow the ratio of abundance of fusion gene to endogenous or exogenous controls to be maintained throughout PCR. Multiplex RT-PCR products analyzed by an ABI 310 Genetic Analyzer were consistent with those of duplex RT-PCR (single analytical sample plus control). In addition, multiplex RT-PCR results were analyzed by an assay using an oligonucleotide microarray that contained probes for the splice-junction sequences of various fusion transcripts.
Results: The multiplex RT-PCR assay enabled screening of &gt;10 different fusion gene transcripts in a single reaction. RT-PCR followed by analysis with the ABI Prism 310 Genetic Analyzer consistently detected 1 fusion-transcript-carrying leukemia cell in 100–10 000 cells. The assay covered a 1000-fold range. Preliminary results indicate that multiplex RT-PCR products can also be analyzed by hybridization-based microarray assay.
Conclusions: The multiplex RT-PCR analyzed by either ABI Prism 310 Genetic Analyzer or microarray provides a sensitive and specific assay for screening of multiple fusion transcripts in leukemia, with the latter an assay that is adaptable to a high-throughput system for clinical screening.
Molecular Beacon Reverse Transcription-PCR of Human Chorionic Gonadotropin-β-3, -5, and -8 mRNAs Has Prognostic Value in Breast Cancer
Authors: Span Paul N , Manders Peggy , Heuvel Joop J T M , Thomas Chris M G , Bosch Remko R , Beex Louk V A M , Sweep C G J (Fred) 
Published: February 2004

AbstractBackground: The β-subunit of human chorionic gonadotropin (hCG) is encoded by four genes, of which expression of the hCGβ-3, -5, and -8 genes could have prognostic value in breast cancer.Methods: Applying a new, modified Molecular Beacon reverse transcription-PCR assay, we investigated the prognostic value of the hCGβ-3, -5, and -8 gene transcripts in 129 sporadic unilateral breast cancer samples from patients with a median follow-up of 62.3 months.Results: Expression of hCGβ-3, -5, -8 was significantly (P = 0.020) associated with relapse-free survival (RFS). In multivariate survival analysis, hCGβ-3, -5, and -8 maintained prognostic value for RFS, with high expression predicting shorter RFS (P = 0.015; hazard ratio, 2.25; 95% confidence interval, 1.17–4.34). Only 1 of 24 (4%) node-negative patients with low hCGβ-3, -5, -8 expression relapsed, in contrast to 7 of 26 (27%) patients with high expression (P = 0.046).Conclusions: Expression of hCGβ-3, -5, -8, which differ by only one nucleotide from other hCGβ genes, can be assessed by our modified Molecular Beacon assay in breast cancer tissues. Expression of hCGβ-3, -5, -8 has independent, prognostic value for RFS in breast cancer and may help identify node-negative patients with poor prognosis.
Plasminogen Activator Inhibitor 1 4G/5G Polymorphism and Coagulation Factor XIII Val34Leu Polymorphism: Impaired Fibrinolysis and Early Pregnancy Loss
Authors: Dossenbach-Glaninger Astrid , van Trotsenburg Michael , Dossenbach Martin , Oberkanins Christian , Moritz Anne , Krugluger Walter , Huber Johannes , Hopmeier Pierre 
Published: February 2004

AbstractBackground: A successful outcome of pregnancy depends on proper placental formation. In the very beginning of this process, trophoblast invasion and fibrin deposition into the wall of the decidual veins play an important part. Two polymorphisms, coagulation factor XIII (FXIII) Val34Leu and plasminogen activator inhibitor 1 (PAI-1) 4G/5G, interfere with fibrin cross-linking and regulation of fibrinolysis and may therefore contribute to early pregnancy loss.Methods: We enrolled 49 unrelated Caucasian women with a history of two consecutive or three to six nonconsecutive early pregnancy losses and 48 unrelated parous healthy controls without a history of pregnancy loss and evaluated them for the following genetic variants: the factor V Leiden and prothrombin G20210A gene mutations, the methylenetetrahydrofolate reductase C677T and A1298C polymorphisms, and the PAI-1 4G/5G and FXIII Val34Leu polymorphisms.Results: For the isolated occurrence of PAI-1 4G/5G or FXIII Val34Leu, we found no statistically significant difference between cases and controls. For homozygosity of either or compound carrier status of both mutations, the overall relative risk for early pregnancy loss was significantly increased (odds ratio = 2.4; 95% confidence interval, 1.1–5.5; P = 0.032). We observed no statistically relevant association of any of the other tested mutations with early pregnancy loss.Conclusion: Homozygosity for PAI-1 4G or FXIII 34Leu polymorphisms as well as compound carrier status is associated with early pregnancy loss.