bluuebunny/crossref_metadata_2025_split huggingface dataset:
Water-free Solution Synthesis of Monodisperse Cu2S Nanocrystals
Authors: Kuzuya Toshihiro , Yamamuro Saeki , Hihara Takehiko , Sumiyama Kenji 
Published: February 2004

Abstract
We report a novel water-free processing of monodisperse and pure Cu2S nanocrystals (NCs) by thermolysis of copper–dodecanethiol complex. The narrow size distribution led to the formation of ordered self-assemblies with various well-defined structures. However, unclose-packing structure was observed as a predominant phase.
Light-triggered Luminescence Modulation Using Labile Axial Coordination to Zinc–Porphyrin
Authors: Otsuki Joe , Narutaki Koichi , Bakke Jan M 
Published: February 2004

Abstract
Modulation of luminescence intensity triggered by light input is demonstrated. The system consists of a Zn–porphyrin and an azopyridine derivative, which axially coordinates to Zn–porphyrin and quenches its fluorescence more efficiently in the trans-form than in the cis-form. Thus, light-induced isomerization of the azopyridine results in the increase/decrease of the porphyrin fluorescence.
Crystal Structure of a Liquid Crystalline Ferrocene Derivative, 1,1′-bis[10-[4-(4-methoxyphenoxycarbonyl)phenoxy]decyloxycarbonyl]ferrocene
Authors: Nakamura Naotake , Okabe Takashi 
Published: February 2004

Abstract
The molecular and crystal structures of 1,1′-disubstituted ferrocene derivative, 1,1′-bis[10-[4-(4-methoxyphenoxycarbonyl)phenoxy]decyloxycarbonyl]ferrocene (bMAF-10) were determined by X-ray diffraction method using the single crystals. The structural molecular feature was the cis conformation (“U” shape) in which the two substituents existed in the same directions, but not the trans conformation (“S” shape) expected in general.
Methodology in Diagnostic Laboratory Test Research in Clinical Chemistry and Clinical Chemistry and Laboratory Medicine
Authors: Lumbreras-Lacarra Blanca , Ramos-Rincón José Manuel , Hernández-Aguado Ildefonso 
Published: February 2004

Abstract
Background: The application of epidemiologic principles to clinical diagnosis has been less developed than in other clinical areas. Knowledge of the main flaws affecting diagnostic laboratory test research is the first step for improving its quality. We assessed the methodologic aspects of articles on laboratory tests.
Methods: We included articles that estimated indexes of diagnostic accuracy (sensitivity and specificity) and were published in Clinical Chemistry or Clinical Chemistry and Laboratory Medicine in 1996, 2001, and 2002. Clinical Chemistry has paid special attention to this field of research since 1996 by publishing recommendations, checklists, and reviews. Articles were identified through electronic searches in Medline. The strategy combined the Mesh term “sensitivity and specificity” (exploded) with the text words “specificity”, “false negative”, and “accuracy”. We examined adherence to seven methodologic criteria used in the study by Reid et al. (JAMA1995;274:645–51) of papers published in general medical journals. Three observers evaluated each article independently.
Results: Seventy-nine articles fulfilled the inclusion criteria. The percentage of studies that satisfied each criterion improved from 1996 to 2002. Substantial improvement was observed in reporting of the statistical uncertainty of indices of diagnostic accuracy, in criteria based on clinical information from the study population (spectrum composition), and in avoidance of workup bias. Analytical reproducibility was reported frequently (68%), whereas information about indeterminate results was rarely provided. The mean number of methodologic criteria satisfied showed a statistically significant increase over the 3 years in Clinical Chemistry but not in Clinical Chemistry and Laboratory Medicine.
Conclusions: The methodologic quality of the articles on diagnostic test research published in Clinical Chemistry and Clinical Chemistry and Laboratory Medicine is comparable to the quality observed in the best general medical journals. The methodologic aspects that most need improvement are those linked to the clinical information of the populations studied. Editorial actions aimed to increase the quality of reporting of diagnostic studies could have a relevant positive effect, as shown by the improvement observed in Clinical Chemistry.
Pharmacodynamic Approach to Immunosuppressive Therapies Using Calcineurin Inhibitors and Mycophenolate Mofetil
Authors: Millán Olga , Brunet Mercè , Campistol Josep M , Faura Ana , Rojo Isabel , Vidal Elena , Jiménez Olga , Vives Jordi , Oppenheimer Federic , Martorell Jaume 
Published: February 2004

Abstract
Background: Graft survival depends on adequate immunosuppression. To evaluate the effect on the immune system of immunosuppressive therapies using calcineurin inhibitors (CNIs), several pharmacodynamic indices have been proposed to complement pharmacokinetic data. In this preliminary study we compared some of these parameters during combined immunosuppressant therapies.
Methods: We treated 65 stable renal transplant recipients with cyclosporin A (CsA; n = 16), tacrolimus (TRL; n = 10); CsA + mycophenolate mofetil (MMF; n = 14); TRL + MMF (n = 13), and MMF (n = 12). Twelve nontreated healthy controls were also included. Calcineurin activity (CNA) in peripheral blood mononuclear cells was measured using 32P-labeled peptide. Interleukin-2 (IL-2) and interferon-γ production in phytohemagglutinin-activated whole blood were measured at 0 and 2 h postdose. The areas under the curves, cmin, cmax, and concentration at 2 h (c2 h) were also measured.
Results: We found no differences in CNA between groups receiving CNIs alone or combined with MMF [median (25th–75th percentiles)]: CsA2 h, 3.87 (3.00–6.85)% alkaline phosphatase (AP); CsA+MMF2 h, 3.90 (1.78–5.19)% AP; TRL2 h, 5.68 (3.02–16.00)% AP; TRL+MMF2 h, 11.80 (4.05–14.63)% AP. In vitro IL-2 production was significantly lower in the groups receiving combined therapy than in groups receiving CNIs alone [median (25th–75th percentiles)]: CsA2 h, 276.52 (190.41–385.25) ng/L; CsA+MMF2 h, 166.48 (81.06–377.01) ng/L (P &lt;0.001); TRL2 h, 249.34 (127.48–363.50) ng/L; TRL+ MMF2 h, 122.13 (51.02–180.00) ng/L (P &lt;0.001). The correlations (r) between c2 h and CNA 2 h postdose were as follows: CsA, r = −0.74; CsA+MMF, r = −0.84; TRL, r = −0.70; TRL+ MMF, r = −0.70 (P &lt;0.001 in all cases).
Conclusions: The measurement of CNA may be of help in following the effect on the immune system of CNI treatments, even in combined therapies, but does not reflect the additional effect of MMF. In contrast, IL-2 in vitro production reflects the effect of both MMF and CNIs.
IgG Subclass Concentrations in Certified Reference Material 470 and Reference Values for Children and Adults Determined with The Binding Site Reagents
Authors: Schauer Uwe , Stemberg Frank , Rieger Christian H L , Borte Michael , Schubert Simone , Riedel Frank , Herz Udo , Renz Harald , Wick Manfred , Carr-Smith Hugh D , Bradwell Arthur R , Herzog Wilhelm 
Published: February 2004

Abstract
Background: There is currently no international reference preparation for IgG subclass (IgGSc) quantification. This situation has led to calibration differences among assays and a variety of reference interval values with consequential difficulties in comparing results. We therefore evaluated IgGSc concentrations in Certified Reference Material 470 (CRM 470).
Methods: Pure, polyclonal IgG1, -2, -3, and -4 were prepared from a large serum pool for use as primary standards. The IgG mass in each preparation was calculated from amino-acid analysis data. IgGSc concentrations were assessed in CRM 470 by nephelometry with modern analytical techniques, using these reference preparations. Subsequently, IgGSc concentrations were measured in 380 healthy individuals (250 males and 130 females), and age-dependent reference intervals were established.
Results: IgGSc concentrations in CRM 470 were as follows: IgG1, 5028 mg/L; IgG2, 3418 mg/L; IgG3, 579 mg/L, and IgG4, 381 mg/L, with a total IgG concentration of 9406 mg/L, 2.83% below the certified total IgG value of 9680 mg/L. Age-dependent percentile curves for the four IgGSc were constructed using a Box–Cox transformation. Maximum median values were as follows: IgG1, 6.02 g/L at 11 years; IgG2, 3.45 g/L at 31 years; IgG3, 0.63 g/L at 17 years; and IgG4, 0.48 g/L at 14 years. No significant sex-related differences were observed.
Conclusions: The correlation between the summation of individual IgGSc and separate measurements of total IgG concentrations was good and supports the accuracy of the results. The results are based on The Binding Site assays and should not be considered appropriate for other assays unless so demonstrated.
Improved HPLC Method for Carbohydrate-deficient Transferrin in Serum
Authors: Helander Anders , Husa Asgeir , Jeppsson Jan-Olof 
Published: February 2004

Abstract
Background: There is need for a reference method for transferrin glycoforms in serum to which routine immunologic methods for the alcohol marker carbohydrate-deficient transferrin (CDT) can be traceable. We describe an improved HPLC method for transferrin glycoforms.
Methods: Transferrin was iron-saturated by mixing the serum with ferric nitrilotriacetic acid, and lipoproteins were precipitated with dextran sulfate and calcium chloride. Separation of glycoforms was performed on a SOURCE 15Q anion-exchange column using salt gradient elution. Quantification relied on selective absorbance of the iron–transferrin complex at 470 nm. The relative amount of each glycoform was calculated as a percentage of the area under the curve, using baseline integration.
Results: The HPLC system provided reproducible separation and quantification of the asialo-, monosialo-, disialo-, trisialo-, tetrasialo-, pentasialo-, and hexasialotransferrin glycoforms. Most importantly, disialo- and trisialotransferrin were almost baseline separated. The intra- and interassay CV for disialotransferrin were &lt;5%. Serum and the pretreated samples were stable for at least 2 days at 22 or 4 °C. Sera from 132 healthy controls contained [mean (SD)] 1.16 (0.25)% disialotransferrin, 4.77 (1.36)% trisialotransferrin, 80.18 (2.01)% tetrasialotransferrin, and 13.88 (1.69)% pentasialo- + hexasialotransferrin. In some cases of a high (&gt;6%) trisialotransferrin, monosialotransferrin was detected at &lt;0.25%. Asialotransferrin was not detected in control sera, but was detected in 57% of chronic heavy drinkers and in 62% of sera with ≥2% disialotransferrin.
Conclusions: The HPLC method fulfills the requirements of a preliminary reference method for CDT and should work for any combination of serum transferrin glycoforms. This method could also be useful for confirming positive CDT results by immunoassays in medico-legal cases.
Evaluation of Oligonucleotide Arrays for Sequencing of the p53 Gene in DNA from Formalin-Fixed, Paraffin-Embedded Breast Cancer Specimens
Authors: Cooper Melissa , Li Shu-Qiu , Bhardwaj Tajinder , Rohan Thomas , Kandel Rita A 
Published: February 2004

AbstractBackground: Routine tissue processing has generated banks of paraffin-embedded tissue that could be used in retrospective cohort studies to study the molecular changes that occur during cancer development. The purpose of this study was to determine whether a p53 microarray could be used to sequence the p53 gene in DNA extracted from formalin-fixed, paraffin-embedded (FFPE) tissues.Methods: DNA was extracted from 70 FFPE breast cancer tissue specimens. p53 was sequenced with an oligonucleotide microarray (p53 GeneChip®; Affymetrix), and the results were compared with the results obtained from direct sequencing.Results: DNA was extracted from 62 of 70 cases. We identified 26 mutations in 24 of the 62 cases by the p53 GeneChip. No polymorphisms were detected, and exon 4 could not be evaluated in 20 cases. There were 43 genetic alterations detected by direct sequencing in 35 of the 62 cases. These consisted of 26 polymorphisms and 17 mutations in exons or splice sites. Fifteen mutations were identified by both methods. Direct sequencing detected significantly more gene alterations (43 of 54) in DNA extracted from FFPE tissue than the p53 GeneChip (26 of 54; P = 0.018). However, if the changes in exon 4 were eliminated from this comparison, the p53 GeneChip detected 26 of 27 mutations compared with direct sequencing, which identified 16 of 27 mutations. (P = 0.016).Conclusions: A combination of oligonucleotide microarray and direct sequencing may be necessary to accurately identify p53 gene alterations in FFPE breast cancer. The p53 GeneChip cannot be used to detect exon 4 polymorphisms (codon 72) in FFPE breast cancer tissue.
High Preoperative CA 15-3 Concentrations Predict Adverse Outcome in Node-Negative and Node-Positive Breast Cancer: Study of 600 Patients with Histologically Confirmed Breast Cancer
Authors: Duffy Michael J , Duggan Catherine , Keane Rachel , Hill Arnold D K , McDermott Enda , Crown John , O’Higgins Niall 
Published: February 2004

AbstractBackground: CA 15-3 is the most widely used serum marker in breast cancer. Currently, its main uses are in the surveillance of patients with diagnosed disease and monitoring the treatment of patients with advanced disease.Methods: Preoperative CA 15-3 concentrations were measured prospectively in 600 patients with histologically confirmed breast cancer. Marker concentrations were related to patient outcome by both univariate and multivariate analysis.Results: After a median follow-up of 6.27 years, patients with high preoperative concentrations of CA 15-3 (&gt;30 units/L) had a significantly shorter overall survival pattern than those with low concentrations. As a prognostic factor, CA 15-3 was independent of tumor size, axillary node status, and patient age. As well as being prognostic in the total population of patients, CA 15-3 also predicted outcome in different subgroups of patients, including those with both node-negative and node-positive disease, those who were both estrogen receptor (ER)-negative and ER-positive, and those younger and older that 50 years of age. CA 15-3 was also predictive of outcome irrespective of the type of adjuvant therapy administered, i.e., whether adjuvant hormone therapy, adjuvant chemotherapy, or radiotherapy was administered.Conclusion: Assay of CA 15-3 is a relatively inexpensive, convenient, and noninvasive method for evaluating prognosis in newly diagnosed breast cancer patients.
In Vitro Contamination of Hair by Marijuana Smoke
Authors: Thorspecken Jana , Skopp Gisela , Pötsch Lucia 
Published: February 2004

AbstractBackground: The deposition of cannabinoids on/into hair from environmental smoke can be considered as a potential source of drug findings in hair. We studied external uptake of cannabinoids from marijuana smoke, investigating possible influencing factors on drug uptake and the efficiency of decontamination procedures.Methods: Strands of a natural hair sample were moistened with water, greased with sebum or sebum/sweat, or bleached or permed. Treated and untreated samples were exposed to marijuana smoke for 60 min. Aliquots of each hair strand were either kept unwashed or were washed with methanol, dichloromethane, or 5 g/L dodecyl sulfate in water. Cannabinoid concentrations in unwashed and washed hair samples, as well as in air samples collected from the exposure chamber and in the marijuana sample being combusted, were quantified by gas chromatography–mass spectrometry or gas chromatography.Results: Cannabinoids were deposited on the hair fibers from marijuana smoke. Cannabinoid concentrations were dependent on air concentration and hair pretreatment. Uptake was less in untreated than in pretreated hair. Concentrations were increased in damp hair, but were even higher in greased hair. There was no significant difference in concentration between bleached and permed strands. External contaminants were completely removed by washing with methanol and dichloromethane in untreated hair only. Washing with dodecyl sulfate in water was insufficient in all cases.Conclusions: Exposures of hair to marijuana smoke yields detectable cannabinoids depending on concentrations in the air, hair care habits, and cosmetic treatment. Environmental marijuana smoke exposure may produce false-positive or falsely increased test results in hair.
Properties of the Reverse Transcription Reaction in mRNA Quantification
Authors: Ståhlberg Anders , Håkansson Joakim , Xian Xiaojie , Semb Henrik , Kubista Mikael 
Published: February 2004

AbstractBackground: In most measurements of gene expression, mRNA is first reverse-transcribed into cDNA. We studied the reverse transcription reaction and its consequences for quantitative measurements of gene expression.Methods: We used SYBR green I-based quantitative real-time PCR (QPCR) to measure the properties of reverse transcription reaction for the β-tubulin, glyceraldehyde-3-phosphate dehydrogenase, Glut2, CaV1D, and insulin II genes, using random hexamers, oligo(dT), and gene-specific reverse transcription primers.Results: Experimental variation in reverse transcription-QPCR (RT-QPCR) was mainly attributable to the reverse transcription step. Reverse transcription efficiency depended on priming strategy, and the dependence was different for the five genes studied. Reverse transcription yields also depended on total RNA concentration.Conclusions: RT-QPCR gene expression measurements are comparable only when the same priming strategy and reaction conditions are used in all experiments and the samples contain the same total amount of RNA. Experimental accuracy is improved by running samples in (at least) duplicate starting with the reverse transcription reaction.
Differential Gene Expression of Eph Receptors and Ephrins in Benign Human Tissues and Cancers
Authors: Hafner Christian , Schmitz Gerd , Meyer Stefanie , Bataille Frauke , Hau Peter , Langmann Thomas , Dietmaier Wolfgang , Landthaler Michael , Vogt Thomas 
Published: February 2004

AbstractBackground: Eph receptors and their ligands, the ephrins, represent a large class of cell–cell communication molecules with well-defined developmental functions. Their role in healthy adult tissues and in human disease is still largely unknown, although diverse roles in carcinogenesis have been postulated.Methods: We established a set of fluorescent PCR probes and primers for the definition of individual gene expression profiles of 12 different Eph receptors and 8 ephrins in 13 different healthy tissues. The mRNA expression profiles were studied in human lung, colorectal, kidney, liver, and brain cancers.Results: The family of Eph receptors/ephrins was widely expressed in adult tissues with organ-site-specific patterns: EphB6 was highest in the thymus, compatible with an involvement in T-cell maturation. Brain and testis shared a unique pattern with EphA6, EphA8, and EphB1 being the most prominent. EphA7 had a high abundance in the kidney vasculature. Ephrin-A3 was up-regulated 26-fold in lung cancer, and EphB2 was up-regulated 9-fold in hepatocellular carcinoma. EphA8 was down-regulated in colon cancer, and EphA1/EphA8 was down-regulated in glioblastomas.Conclusion: Eph/Ephrin genes are widely expressed in all adult organs with certain organ-site-specific patterns. Because their function in adult tissues remains unknown, further analysis of their role in disease may disclose new insights beyond their well-defined meaning in development.
Improved Specificity of Newborn Screening for Congenital Adrenal Hyperplasia by Second-Tier Steroid Profiling Using Tandem Mass Spectrometry
Authors: Lacey Jean M , Minutti Carla Z , Magera Mark J , Tauscher Angela L , Casetta Bruno , McCann Mark , Lymp James , Hahn Si Houn , Rinaldo Piero , Matern Dietrich 
Published: February 2004

Abstract
Background: Newborn screening for congenital adrenal hyperplasia (CAH) involves measurement of 17α-hydroxyprogesterone (17-OHP), usually by immunoassay. Because this testing has been characterized by high false-positive rates, we developed a steroid profiling method that uses liquid chromatography–tandem mass spectrometry (LC-MS/MS) to measure 17-OHP, androstenedione, and cortisol simultaneously in blood spots.
Methods: Whole blood was eluted from a 4.8-mm (3/16-inch) dried-blood spot by an aqueous solution containing the deuterium-labeled internal standard d8-17-OHP. 17-OHP, androstenedione, and cortisol were extracted into diethyl ether, which was subsequently evaporated and the residue dissolved in LC mobile phase. This extract was injected into a LC-MS/MS equipped with pneumatically assisted electrospray. The steroids were quantified in the selected-reaction monitoring mode by use of peak areas in reference to the stable-isotope-labeled internal standard. We analyzed 857 newborn blood spots, including 14 blood spots of confirmed CAH cases and 101 of false-positive cases by conventional screening.
Results: Intra- and interassay CVs for 17-OHP were 7.2–20% and 3.9–18%, respectively, at concentrations of 2, 30, and 50 μg/L. At a cutoff for 17-OHP of 12.5 μg/L and a cutoff of 3.75 for the sum of peak areas for 17-OHP and androstenedione divided by the peak area for cortisol, 86 of the 101 false-positive samples were within reference values by LC-MS/MS, whereas the 742 normal and 14 true-positive results obtained by conventional screening were correctly classified.
Conclusion: Steroid profiling in blood spots can identify false-positive results obtained by conventional newborn screening for CAH.
Prognostic Value of Tubular Proteinuria and Enzymuria in Nonoliguric Acute Tubular Necrosis
Authors: Herget-Rosenthal Stefan , Poppen Dennis , Hüsing Johannes , Marggraf Günter , Pietruck Frank , Jakob Heinz-Günther , Philipp Thomas , Kribben Andreas 
Published: February 2004

AbstractBackground: Acute tubular necrosis (ATN) has high mortality, especially in patients who require renal replacement therapy (RRT). We prospectively studied the diagnostic accuracy of the urinary excretion of low-molecular-weight proteins and enzymes as predictors of a need for RRT in ATN.Methods: In 73 consecutive patients with initially nonoliguric ATN, we measured urinary excretion of α1- and β2-microglobulin, cystatin C, retinol-binding protein, α-glutathione S-transferase, γ-glutamyltransferase, lactate dehydrogenase, and N-acetyl-β-d-glucosaminidase early in the course of ATN.Results: Twenty-six patients (36%) required RRT a median of 4 (interquartile range, 2–6) days after detection of proteinuria and enzymuria. Patients who required RRT had higher urinary cystatin C and α1-microglobulin [median (interquartile range), 1.7 (1.2–4.1) and 34.5 (26.6–45.1) g/mol of creatinine] than patients who did not require RRT [0.1 (0.02–0.5) and 8.0 (5.0–17.5) g/mol of creatinine]. Urinary excretion of cystatin C and α1-microglobulin had the highest diagnostic accuracies in identifying patients requiring RRT as indicated by the largest areas under the ROC curves: 0.92 (95% confidence interval, 0.86–0.96) and 0.86 (0.78–0.92), respectively. Sensitivity and specificity were 92% (95% confidence interval, 83–96%) and 83% (73–90%), respectively, for urinary cystatin C &gt;1 g/mol of creatinine, and 88% (78–93%) and 81% (70–88%) for urinary α1-microglobulin &gt;20 g/mol of creatinine.Conclusion: In nonoliguric ATN, increased urinary excretion of cystatin C and α1-microglobulin may predict an unfavorable outcome, as reflected by the requirement for RRT.