bluuebunny/crossref_metadata_2025_split huggingface dataset:
Uniform solid-phase extraction procedure for toxicological drug screening in serum and urine by HPLC with photodiode-array detection
Authors: Lai Chi-Kong , Lee Ting , Au Kam-Ming , Chan Albert Yan-Wo 
Published: January 2020

AbstractIn this HPLC–diode-array detection method for toxicological drug screening, a mixed-mode solid-phase extraction procedure is optimized for isolation of a broad range of drugs from serum and urine. Basic, neutral, and weakly acidic drugs are uniformly recovered. The extract from the solid-phase cartridge is readily injected to a reversed-phase HPLC column for separation by gradient elution. Unknown drugs and metabolites in urine and serum samples from acute drug poisoning cases are rapidly identified by matching their retention times and ultraviolet spectra with hundreds of reference compounds in the library. Urine metabolites of common toxicants from various medications and drugs of abuse are recorded, with their changes of retention times and ultraviolet spectra as related to their metabolic transformations. Glucuronide conjugates of common benzodiazepines, tricyclic antidepressants, and beta-blockers are examined directly without chemical or enzymatic hydrolysis. The system is reliable for diverse clinical investigations of drug overdoses, drug-induced psychoses, and substance abuse.
Increased serum concentration of carbohydrate-deficient transferrin in patients with combined pancreas and kidney transplantation
Authors: Arndt Torsten , Hackler Rolf , Müller Thomas , Kleine Tilman O , Gressner Axel M 
Published: January 2020

AbstractSerum concentration of carbohydrate-deficient transferrin (cCDT) is used for laboratory diagnosis and follow-up of chronic alcohol abuse. In analyzing by CDTect-RIA (Pharmacia) sera from outpatients with combined pancreas and kidney transplantation and no excessive alcohol consumption, we found above-normal values for cCDT and CDT/transferrin ratios (CDT/Tf) in more than half of the samples. Isoelectric focusing of these samples showed distinct bands of carbohydrate-deficient isotransferrins, supporting the abnormal findings from the CDTect assay. In contrast, diabetics and outpatients who had received only kidney transplants showed normal values for cCDT, CDT/Tf, and isotransferrin patterns. Increased serum Tf, sialidase-producing microorganisms, and immunosuppressive medication were eliminated as causes of these abnormal cCDT and CDT/Tf results. Successful pancreas transplantation leads to hyperinsulinemia and normoglycemia, in contrast to hypoinsulinemia and hyperglycemia in the patients who receive kidney transplants alone. These factors may have pathogenic importance for CDT increase, yielding results falsely interpreted as positive with respect to alcohol abuse in patients with combined pancreas and kidney transplantation.
Comparison of methods for measurement of apolipoprotein B and cholesterol in low-density lipoproteins
Authors: Vrga Ljubica , Contacos Christine , Li Stephen C H , Sullivan David R 
Published: January 2020

AbstractWe describe a new method for the direct measurement of LDL-apolipoprotein (apo) B by using a commercial kit that isolates LDL by immunoseparation. We evaluated immunoseparation of LDL for apo B and cholesterol measurement in 46 dyslipidemic patients with LDL-cholesterol (LDL-C) between 1.5 and 8.2 mmol/L, 11 of whom had plasma triglyceride (TG) concentrations &gt;4.0 mmol/L. There was a reasonable correlation (r = 0.94, n = 40) between LDL-apo B obtained after immunoseparation and d &gt;1.006 kg/L apo B obtained after ultracentrifugation. LDL-C by the immunoseparation method also correlated well (r = 0.98, n = 46) with the d &gt;1.006 kg/L cholesterol after ultracentrifugation. These results show that immunoseparation can be used to determine LDL-apo B, even in hypertriglyceridemic samples. This method may provide a quick and simple alternative for the identification of hyperapobetalipoproteinemia, even when TG concentrations are high.
Improved reverse transcriptase–polymerase chain reaction protocol with exogenous internal competitive control for prostate-specific antigen mRNA in blood and bone marrow
Authors: Corey Eva , Arfman Edward W , Liu Alvin Y , Vessella Robert L 
Published: January 2020

AbstractThe possibility of improving diagnosis of micrometastases from prostate cancer by further enhancing the detection of prostate-specific antigen-producing cells in circulation is being evaluated. We have developed a reverse transcriptase-PCR protocol with the desirable characteristics of low limit of detection, high specificity, reproducibility of response, and ease of performance. Among the procedural alterations that have contributed to these improvements are longer PCR primers, a two-step amplification cycle, and hot-start PCR. We have lowered the limit of detection to one LNCaP prostate-cancer cell in 108 peripheral blood mononuclear cells, and samples of blood and bone marrow from healthy donors have yielded no false positives. Because PCR procedures frequently exhibit tube-to-tube variability, we have incorporated a set of internal and external controls into the protocol—a significant advance in assuring assay reliability.
Improved troponin T ELISA specific for cardiac troponin T isoform: assay development and analytical and clinical validation
Authors: Müller-Bardorff Margit , Hallermayer Klaus , Schröder Angelika , Ebert Christoph , Borgya Anneliese , Gerhardt Willie , Remppis Andrew , Zehelein Jörg , Katus Hugo A 
Published: January 2020

AbstractThe first generation of troponin T ELISA (TnT 1) can yield false-positive results in patients with severe skeletal muscle injury. Therefore, a cardiac-specific second-generation troponin T ELISA (TnT 2) was developed, in which the cross-reactive antibody 1B10 has been replaced by a high-affinity cardiac-specific antibody M11.7. No cross-reactivity of TnT 2 was observed with purified skeletal muscle troponin T (1000 μg/L) or in test samples from 43 marathon runners and 24 patients with rhabdomyolysis and highly increased creatine kinase. TnT 2 was increased &gt;0.2 μg/L in 5 of 40 patients with renal failure and in 4 of 20 muscular dystrophy patients. The detection limit is 0.012 μg/L. Day-to-day imprecision (CV) within the range 0.19–14.89 μg/L was &lt;5.8%. In 4955 patients without myocardial damage, 99.6% had TnT &lt;0.10 μg/L. Assay comparison (TnT 1 vs TnT 2) over the whole concentration range (i.e., in 323 samples from AMI-suspected patients) showed a slope, intercept, and standard error of estimate (Sey) of 1.18, 0.01 μg/L, and 0.81 μg/L, respectively.
Novel bispecific immunoprobe for rapid and sensitive detection of prostate-specific antigen
Authors: Kreutz Fernando T , Suresh Mavanur R 
Published: January 2020

Abstract
Prostate-specific antigen (PSA) is one of the most useful tumor markers for the screening and follow-up of prostate cancer. Bispecific monoclonal antibodies (bsMAbs) are unique immunoprobes that incorporate two different binding sites in the same antibody molecule. This antibody designing can bring important advantages in the development of new immunoassays. We have developed a new hybrid hybridoma that secretes bsMAb anti-PSA × anti-horseradish peroxidase. This bsMAb has shown rapid kinetics and an excellent detection limit in a sandwich single-step assay with a total incubation time of 15 min and a 5-min substrate development. This assay in a manual format has a detection limit of 0.028 μg/L. Comparison with the Hybritech Tandem-E® PSA assay yielded a regression equation with slope = 0.433 [95% confidence interval (CI) = 0.415–0.451], intercept = 0.88 (CI = 0.45–1.31), and Sy|x = 1.83 μg/L (r = 0.98). This new immunoprobe can be used to develop a new generation of assays for clinical laboratories and can be adapted to screening devices for physicians’ offices and even home diagnostics.
Telomeres and telomerase: biological and clinical importance
Authors: Dahse Regine , Fiedler Wolfgang , Ernst Günther 
Published: January 2020

AbstractWe review the present knowledge of telomeres and telomerase with special attention to their role in cell proliferation, cellular senescence, and human aging. We summarize the functional aspects of telomerase in cancer, as well as its role as a useful diagnostic and prognostic tumor marker, and discuss possible approaches to telomerase inhibition as a target for cancer therapy.
Convenient chromatographic prepurification step before measurement of urinary cortisol by radioimmunoassay
Authors: Morineau Gilles , Gosling James , Patricot Marie-Claude , Soliman Hany , Boudou Philippe , Halnak Akram Al , Le Brun Gaëlle , Brérault Jean-Louis , Julien René , Villette Jean-Marie , Fiet Jean 
Published: January 2020

Abstract
We applied various prepurification protocols (extraction with different solvents, liquid/solid separation on bonded silica media, Celite, and Sephadex LH20 chromatography) with a range of commercially available RIA kits to measure cortisol in urine samples. We then compared the results with the concentrations measured by a HPLC method validated with reference to isotope dilution gas chromatography–mass spectrometry. We conclude that chromatography on a commercial, prepacked diol minicolumn (Waters™ Sep-Pak Vac RC) in combination with dichloromethane extraction is a convenient and very effective purification step before RIA of urinary cortisol in patients not receiving corticoid medication. We tested numerous steroids for interference and found that free polar cortisol derivatives (hydroxylated or hydrogenated) could only partially account for the overestimations routinely encountered when free urinary cortisol concentrations are measured by direct RIA.
Screening blood spots for inborn errors of metabolism by electrospray tandem mass spectrometry with a microplate batch process and a computer algorithm for automated flagging of abnormal profiles
Authors: Rashed Mohamed S , Bucknall Martin P , Little Douglas , Awad Amin , Jacob Minnie , Alamoudi Mohamed , Alwattar Mona , Ozand Pinar T 
Published: January 2020

AbstractMetabolic profiling of amino acids and acylcarnitines from blood spots by automated electrospray tandem mass spectrometry (ESI-MS/MS) is a powerful diagnostic tool for inborn errors of metabolism. New approaches to sample preparation and data interpretation have helped establish the methodology as a robust, high-throughput neonatal screening method. We introduce an efficient 96-well-microplate batch process for blood-spot sample preparation, with which we can obtain high-quality profiles from 500-1000 samples per day per instrument. A computer-assisted metabolic profiling algorithm automatically flags abnormal profiles. We selected diagnostic parameters for the algorithm by comparing profiles from patients with known metabolic disorders and those from normal newborns. Reference range and cutoff values for the diagnostic parameters were established by measuring either metabolite concentrations or peak ratios of certain metabolite pairs. Rigorous testing of the algorithm demonstrates its outstanding clinical sensitivity in flagging abnormal profiles and its high cumulative specificity.
Serum concentrations of free ubiquitin and multiubiquitin chains
Authors: Takada Koji , Nasu Hidekazu , Hibi Nozomu , Tsukada Yutaka , Shibasaki Toshiaki , Fujise Kiyotaka , Fujimuro Masahiro , Sawada Hitoshi , Yokosawa Hideyoshi , Ohkawa Kiyoshi 
Published: January 2020

AbstractUbiquitin, which can conjugate with cellular proteins, is classified into two forms: free ubiquitin and multiubiquitin chains. The latter is active as a signal for degradation of the targeted proteins. We found both forms in human serum and, using two immunoassays, quantitated them in sera from healthy subjects and patients with some diseases. Because of putative leakage of erythrocyte ubiquitin, hemolytic serum and serum obtained after long incubation (&gt;1–2 h) of blood at room temperature were excluded. Serum concentrations of multiubiquitin chains and free ubiquitin were substantially higher in rheumatoid arthritis and hemodialysis patients, respectively, than healthy subjects. Additionally, in acute viral hepatitis, serum multiubiquitin chain concentrations were increased in the acute phase, decreased in the recovery phase, and correlated with alanine and aspartate aminotransferase activities (r = 0.676 and 0.610, P &lt;0.0001 and &lt;0.001, respectively). Therefore, serum ubiquitin may have prognostic value.
Analytical performance of the Tandem®-R free PSA immunoassay measuring free prostate-specific antigen
Authors: Woodrum David L , French Chester M , Hill Timothy M , Roman Steven J , Slatore Harold L , Shaffer Jennifer L , York Lisa G , Eure Kathy L , Loveland Kathleen G , Gasior Gail H , Southwick Paula C , Shamel L Blair 
Published: January 2020

Abstract
The analytical performance of the Tandem®-R free PSA assay available from Hybritech Inc. was evaluated. Comparison of recoveries of purified free (unbound) prostate-specific antigen (PSA) diluted in female serum in the Tandem-R free PSA assay and the Tandem-R (total) PSA assay demonstrated a link in calibration between the assays and an accurate determination of percent free PSA. The cross-reactivity of the assay to purified PSA–α1-antichymotrypsin was determined to be &lt;1%. The minimum-detectable concentration was &lt;0.05 μg/L. The within-run and between-day CVs were ≤5% for samples with &gt;0.3 μg/L free PSA. Dilution and recovery showed no significant deviations from linearity across the assay range. The assay was insensitive to interference from blood components. The Tandem-R free PSA kit was shown to be an accurate, precise, and reliable assay for the measurement of free PSA.
Issues in detecting abuse of xenobiotic anabolic steroids and testosterone by analysis of athletes’ urine
Authors: Catlin Don H , Hatton Caroline K , Starcevic Sanja H 
Published: January 2020

AbstractOver the last decade the number of laboratories accredited by the International Olympic Committee (IOC) has grown to 25. Nearly half of the ∼90 000 samples tested annually are collected on short notice—the most effective means to deter the use of anabolic androgenic steroids (AAS). The major urinary metabolites of AAS have been characterized and are identified by their chromatographic retention times and full or partial mass spectra. The process of determining if an athlete has used testosterone (T) begins with finding a T to epitestosterone (E) ratio &gt;6 and continues with a review of the T/E–time profile. For the user who discontinues taking T, the T/E reverts to baseline (typically ∼ 1.0). For the extremely rare athlete with a naturally increased T/E ratio, the T/E remains chronically increased. Short-acting formulations of T transiently increase T/E, and E administration lowers it. Among ancillary tests to help discriminate between naturally increased T/E values and those reflecting T use, the most promising is determination of the carbon isotope ratio.
Diagnosis of lysosomal storage disorders: evaluation of lysosome-associated membrane protein LAMP-1 as a diagnostic marker
Authors: Meikle Peter J , Brooks Doug A , Ravenscroft Elaine M , Yan Miao , Williams Ruth E , Jaunzems Alvis E , Chataway Timothy K , Karageorgos Litsa E , Davey Richard C , Boulter Christine D , Carlsson Sven R , Hopwood John J 
Published: January 2020

AbstractEarly diagnosis of lysosomal storage disorders (LSDs), before the onset of irreversible pathologies, will be a key factor in the development of effective therapies for many of these disorders. Newborn screening offers a potential mechanism for the early detection of these disorders. From studies of both normal and LSD-affected human skin fibroblasts we identified the lysosome-associated membrane protein LAMP-1 as a potential diagnostic marker. We have developed a sensitive method for the quantification of this protein with a time-resolved fluorescence immunoassay. A soluble form of LAMP-1 was observed in plasma samples, and determination of 152 unaffected individuals gave a median value of 303 μg/L with the 5th and 95th percentile at 175 and 448 μg/L respectively. Plasma samples from 320 LSD-affected individuals representing 25 different disorders were assayed. We observed that 17 of the 25 disorder groups tested had &gt;88% of individuals above the 95th percentile of the control population, with 12 groups having 100% above the 95th percentile. Overall, 72% of patients had LAMP-1 concentrations above the 95th percentile of the unpartitioned control population. We suggest that LAMP-1 may be a useful marker in newborn screening for LSDs.
Effect of anti-thyroid peroxidase (TPO) antibodies on TPO activity measured by chemiluminescence assay
Authors: Kaczur V , Vereb Gy , Molnár I , Krajczár G , Kiss E , Farid N R , Balázs Cs 
Published: January 2020

AbstractA chemiluminescence method was developed to measure thyroid peroxidase (TPO) activity and the inhibitory effect of anti-TPO antibodies in purified porcine TPO. The TPO preparation was characterized kinetically and controlled by Western-blotting technique. The chemiluminescence method proved to be reproducible and much more sensitive than the widely used guaiacol method, being able to detect TPO concentrations of 2.21 × 10−5 g/L vs 6.63 × 10−2g/L with the latter. Otherwise, the determinations with the two methods correlated well (r = 0.76). Investigating the effect of IgGs from 23 hypothyroid patients on measured TPO activity, we detected inhibition in 19 cases with the chemiluminescence technique (15 with the guaiacol method). Anti-TPO antibodies showed competitive inhibition of TPO activity with respect to the substrate guaiacol. In both systems, the inhibition is present in the IgG F(ab′)2 fragment. We conclude that the high sensitivity of chemiluminescence detection allows routine determination of the inhibition of TPO activity by anti-TPO antibodies.
Fatty acid ethyl esters: short-term and long-term serum markers of ethanol intake
Authors: Laposata Michael 
Published: January 2020

AbstractThis review includes a description of short-term and long-term markers of ethanol intake and their clinical utility. The major portion of this report is a summary of studies on fatty acid ethyl ester, a new marker for monitoring both acute and chronic ethanol intake. With the markers described in the review, algorithms to assess recent ethanol intake, chronic ethanol intake, and end organ damage are included to provide a practical approach to the evaluation of the patient.
Novel analytical approach to monitoring advanced glycosylation end products in human serum with on-line spectrophotometric and spectrofluorometric detection in a flow system
Authors: Wróbel Kazimierz , Wróbel Katarzyna , Garay-Sevilla Ma Eugenia , Nava Laura Eugenia , Malacara Juan Manuel 
Published: January 2020

AbstractWe proposed a simple analytical procedure for measurement of serum advanced glycosylation end products (AGEs) based on simultaneous detection of low-molecular-mass peptides and AGEs with a flow system and two detectors connected on-line: spectrophotometric for peptides (λ = 280 nm) and spectrofluorometric for AGEs (λex = 247 nm, λem = 440 nm). Sample pretreatment was carried out in microcentrifuge tubes: Serum (20 μL) was deproteinized with trichloroacetic acid (480 μL, 0.15 mol/L) and lipids were extracted with chloroform (100 μL). Twenty microliters of the filtered aqueous layer was injected to the flow system and the relation between fluorescence and absorption signals was measured. A peptide-derived AGE calibrator was used for calibration. Within-day and between-day CVs were 6.7% and 9.1%, respectively, at an AGE concentration corresponding approximately to that in healthy individuals. Mean results (±SD) in 10 healthy individuals were 10.1% ± 1.0%, in 21 patients with diabetes without complications 18.0% ± 6.2%, in 25 patients with complications 24.1% ± 15.4%, and in 12 diabetic patients in end-stage renal disease 92% ± 30%. Comparison with an ELISA procedure (x, in arbitrary units/L) yields a regression equation y = 0.713x + 1.24 (Sy‖x = 6777, r = 0.8477, n = 41).
Point-of-care fibrinolytic tests: the other side of blood coagulation
Authors: Oberhardt Bruce J , Mize Patrick D , Pritchard Cynthia G 
Published: January 2020

Abstract
Point-of-care (POC) coagulation tests with paramagnetic iron oxide particles have provided alternatives to testing previously done only in the laboratory. With this technology, POC fibrinolytic tests have followed quietly the trail blazed by POC clotting tests and have found specific applications. These include rapid verification of in vivo thrombolytic drug action by in vitro testing with subsequent quantitative drug monitoring of the systemic lytic state, and also the determination of in vitro thrombolytic drug response before the drug is actually administered, to individualize therapy by selection of the most appropriate drug. Other applications include POC coagulation factor assays associated with fibrinolysis, and most recently the POC screening of patients with fibrinolytic defects. In this latter application, plasma from cardiac catheterization (n = 19) and venous thrombosis (n = 47) patient groups were tested. Controls consisted of two independent donor pools (n = 10, n = 21) as negatives and two plasma samples with known genetic defects in the fibrinogen molecule (Aα554 Arg → Cys) as positives.
Coagulation monitor based on serum migration through absorbent materials
Authors: Wilson Paul E 
Published: January 2020

Abstract
I describe a method to measure blood coagulation properties, based on the hypothesis that the distance the serum component of a clotted plasma sample moves through a suitable absorbent material should be proportional to the blood’s ability to clot. A simple apparatus was constructed to test this principle, in which an absorbent strip contacts clotted plasma samples. At various times, the liquid migration distance into the strip was measured and correlated with clotting times determined by well-accepted procedures. Use of this device to test lyophilized normal and barium-absorbed plasmas, factor VII-deficient plasma, frozen normal plasmas, plasmas from patients undergoing oral anticoagulation, and saline-diluted plasmas (as for Quick Percent assays) showed that clotting times correlated with migration distances for all types of samples (r2 = 0.93–0.99). The device distinguishes between samples from normal and coumadin-treated subjects. The concept can be integrated into an inexpensive, point-of-care coagulation monitor.
Advanced multiplexed analysis with the FlowMetrixTM system
Authors: Fulton R Jerrold , McDade Ralph L , Smith Perry L , Kienker Laura J , Kettman John R 
Published: January 2020

Abstract
The FlowMetrixTM System is a multiplexed data acquisition and analysis platform for flow cytometric analysis of microsphere-based assays that performs simultaneous measurement of up to 64 different analytes. The system consists of 64 distinct sets of fluorescent microspheres and a standard benchtop flow cytometer interfaced with a personal computer containing a digital signal processing board and Windows95®-based software. Individual sets of microspheres can be modified with reactive components such as antigens, antibodies, or oligonucleotides, and then mixed to form a multiplexed assay set. The digital signal-processing hardware and Windows95-based software provide complete control of the flow cytometer and perform real-time data processing, allowing multiple independent reactions to be analyzed simultaneously. The system has been used to perform qualitative and quantitative immunoassays for multiple serum proteins in both capture and competitive inhibition assay formats. The system has also been used to perform DNA sequence analysis by multiplexed competitive hybridization with 16 different sequence-specific oligonucleotide probes.