bluuebunny/crossref_metadata_2025_split huggingface dataset:
Use of On-Site Testing for Drugs of Abuse
Authors: George Stephen , Braithwaite Robin A 
Published: January 2020

Abstract
Background: There is currently a profusion of near-patient testing devices that have been specifically targeted at drug dependency units and clinics. Some of these devices have been shown to produce accurate results. However, some devices suffer from inappropriate labeling, which together with the subjective interpretation of poorly defined reaction end-point markers, leads to misinterpretation of the results generated.
Methods: A literature search was conducted regarding the use and evaluation of near-patient testing devices for drugs-of-abuse screening. The results of this research, together our own practical evaluations of such devices, have been collated into this review.
Results: It is proposed that although near-patient testing devices may be useful in remote areas or where rapid action needs to be taken, it should be remembered that they provide only initial screening data and may yield false-positive or -negative results. Such devices need to be used with caution because a rapid but unconfirmed result may lead to misdiagnosis and inappropriate treatment for those who have a drug problem. It should be noted that a single result, which may be inaccurate, could lead to the cessation of treatment and a failure to provide care for those in greatest need. In addition, false-positive results may also have medico-legal implications, especially with the initiation of the drug testing and treatment orders.
Conclusions: Near-patient testing devices for drugs of abuse could be an expensive and potentially inaccurate means to monitor patient treatment and drug abuse status.
Duration of Detectable Methamphetamine and Amphetamine Excretion in Urine after Controlled Oral Administration of Methamphetamine to Humans
Authors: Oyler Jonathan M , Cone Edward J , Joseph Robert E , Moolchan Eric T , Huestis Marilyn A 
Published: January 2020

AbstractBackground: Confirmation of a workplace drug test requires urinary methamphetamine (MAMP) and amphetamine (AMP) concentrations ≥500 and 200 μg/L, respectively, but cutoffs at half those values (250/100 μg/L) have been proposed. We determined the urinary excretion of MAMP after oral ingestion and examined the effect of using lower cutoffs on detection of exposure.Methods: Volunteers (n = 8) ingested four 10-mg doses of MAMP · HCl daily over 7 days, and five of them ingested four 20-mg doses 4 weeks later. After ingestion, the volunteers collected all urine specimens for 2 weeks. After solid-phase extraction, MAMP and AMP were measured by gas chromatography–positive chemical ionization mass spectrometry with dual silyl derivatization.Results: MAMP and AMP were generally detected in the first or second void (0.7–11.3 h) collected after drug administration, with concentrations of 82–1827 and 12–180 μg/L, respectively. Peak MAMP concentrations (1871–6004 μg/L) after single doses occurred within 1.5–60 h. MAMP ≥500 μg/L was first detected in the first or second void (1–11 h) at 524-1871 μg/L. Lowering the MAMP cutoff to 250 μg/L changed the initial detection time little. AMP ≥200 μg/L was first detected in the 2nd–13th (7–20 h) post-administration voids. At a cutoff of 100 μg/L, AMP was first confirmed in the second to eighth void (4–13 h). Reducing the cutoff to 250/100 μg/L extended terminal MAMP detection by up to 24 h, increased total detection time by up to 34 h, and increased the total number of positive specimens by 48%.Conclusions: At the lower cutoff, initial detection times are earlier, detection windows are longer, and confirmation rates are increased. Elimination of the AMP requirement would increase detection rates and allow earlier detection.
Human Adrenal Cells in Culture Produce Both Ouabain-like and Dihydroouabain-like Factors
Authors: El-Masri M Adnan , Clark Barbara J , Qazzaz Hassan M , Valdes Roland 
Published: January 2020

Abstract
Background: Ouabain-like factor (OLF) and its newly discovered reduced species, dihydroouabain-like factor (Dh-OLF), are mammalian cardenolides whose structural and functional characteristics are similar to the plant-derived compounds ouabain and dihydroouabain. These endogenous compounds are believed to be produced by the adrenals and to constitute part of an hormonal axis that may regulate the catalytic activity of the α-subunit of Na+,K+-ATPase. We developed antibodies sufficiently specific to distinguish between OLF and Dh-OLF, and in this study demonstrate the selective secretion of OLF and Dh-OLF from human H295R-1 adrenocortical cells in culture.
Methods: We used reversed-phase HPLC, inhibition of Na+,K+-ATPase catalytic activity, and two enzyme immunoassays developed with antibodies specific to ouabain and dihydroouabain to purify and characterize the secretion of these two compounds by human adrenal cells in culture. Purified antisera had high titers (1 × 106 for ouabain and 8 ×105 for dihydroouabain) and were specific to their corresponding antigens.
Results: Human H295R-1 cells grown in serum-free medium secreted 0.18 ± 0.03 pmol of OLF and 0.39 ± 0.04 pmol of Dh-OLF per 106 cells in 24 h. Both OLF and Dh-OLF inhibited the ouabain-sensitive catalytic activity of the sodium pump (0.03 μmol/L OLF inhibited 29% of the catalytic activity; 0.07 μmol/L Dh-OLF inhibited 17%). Stimulation of the cell culture by dibutryl cAMP increased the secretion of Dh-OLF 50% over control (unstimulated), whereas the secretion of OLF did not increase significantly.
Conclusions: OLF and Dh-OLF are secreted by human adrenal cells, and antibodies specific to these two compounds can be developed, using the plant-derived counterparts as antigens. The secretion of Dh-OLF is responsive to a cAMP-dependent stimulation mechanism, whereas OLF is not. Our data suggest that either the secretory or biosynthetic pathways for production of these two compounds by human adrenal cells may have different control mechanisms or that they may be linked via a precursor–product relationship.
Molecular and Biochemical Studies of Acute Intermittent Porphyria in 196 Patients and Their Families
Authors: Kauppinen Raili , von und zu Fraunberg Mikael 
Published: January 2020

AbstractBackground: Acute intermittent porphyria (AIP) is a metabolic disease with clinical manifestations that mimic other abdominal, neurologic, or mental crises. We studied the diagnostic accuracy of current laboratory tests during an acute attack and in remission.Methods: Since 1966, we have studied all known Finnish AIP patients (n = 196) and their families (n = 45) and identified the porphobilinogen deaminase (PBGD) mutation in each family. Diagnoses or exclusions of AIP were based on clinical data (including family history), biochemical tests, and in 239 cases, mutation testing. We retrospectively evaluated the diagnostic accuracy of erythrocyte PBGD activity, urinary excretion of porphobilinogen (PBG) and δ-aminolevulinic acid, and urinary and fecal excretion of porphyrins in these patients.Results: Measurement of urinary PBG identified all 35 AIP patients studied during an acute attack. The mean excretion of PBG was 50-fold above the reference interval, although the intraindividual increases were modest (1.6- to 4.0-fold). In the mutation-screened population, urinary PBG analysis identified only 85% of 81 AIP patients studied during remission, but by ROC curve analysis it was nonetheless the best of the biochemical tests. It was increased ≤2-fold in 29% of healthy relatives. Erythrocyte PBGD activity was decreased in only 84% of AIP patients, with results within the reference interval mainly in the variant form of AIP; it was decreased in 23% of healthy relatives.Conclusions: Measurement of urinary PBG is the best biochemical test for AIP, although it is unspecific and does not distinguish AIP from other acute porphyrias. Because the acute increase in PBG is often modest, the medical history, signs, and symptoms must be evaluated carefully during an acute attack. In addition, because biochemical analyses often remain indeterminate in remission, mutation analysis is needed to exclude or confirm the diagnosis of AIP.
Evaluation of Coagulation Markers for Early Diagnosis of Acute Coronary Syndromes in the Emergency Room
Authors: Derhaschnig Ulla , Laggner Anton N , Röggla Martin , Hirschl Michael M , Kapiotis Stylianos , Marsik Claudia , Jilma Bernd 
Published: January 2020

Abstract
Background: Diagnosis of acute coronary syndromes (ACS) is a major challenge for emergency physicians. Because soluble fibrin (sF) has been suggested as a potential early marker of impending myocardial ischemia, we were interested whether a sF bedside test could help in early identification of patients with ACS in the emergency department.
Methods: We evaluated plasma coagulation markers, including a newly developed sF bedside test, prothrombin fragment (F1+2), sF, and D-dimer, in a cross-sectional trial with 184 patients suggestive of ACS.
Results: Whereas 76% (13 of 17) of patients with unstable angina pectoris (UAP) had a positive sF bedside test, only 10 of 33 patients (30%) with non-ST-segment-elevation myocardial infarction and 10 of 44 patients (23%) with ST-elevation myocardial infarction tested positive. Three percent of controls (1 of 33) and 11% of patients (6 of 57) with preexisting stable angina had a positive sF bedside test (P &lt;0.001 for noncardiac chest pain vs ACS), yielding an overall specificity of 92% and a sensitivity of 35%. The sensitivity of the established coagulation markers was significantly less to detect ACS (11% for F1+2, 20% for thrombus precursor protein, and 18% for D-dimer; P &lt;0.02 vs sF bedside test). The sF bedside test presented the earliest objective indicator of impending myocardial damage in the majority (10 of 13) of ACS patients with a normal or nondiagnostic electrocardiogram (ECG).
Conclusions: A sF bedside test offers a specific tool for early identification of patients with ACS in an emergency department setting, although its sensitivity seems sufficient only for the early identification of patients with UAP. A sF bedside test could be useful, particularly in UAP patients with a nondiagnostic ECG.
False-Positive Immunoassay Results: A Multicenter Survey of Erroneous Immunoassay Results from Assays of 74 Analytes in 10 Donors from 66 Laboratories in Seven Countries
Authors: Marks Vincent 
Published: January 2020

AbstractBackground: Analytical interference in immunoassays can produce serious errors, but it is generally considered rare with modern analytical systems.Method: Blood was collected from 10 donors with illnesses known to be associated with rheumatoid factor. Immunoassays for 74 analytes were performed in 66 clinical laboratories. Each sample was measured in duplicate, and again in duplicate after the addition of a proprietary heterophil blocking reagent, with the laboratory’s routinely used reagents and equipment. Reagents were typically supplied by the manufacturers of the closed analytical systems. Both competitive and sandwich immunoassays were investigated.Results: Overall ∼8.7% of the 3445 results were considered to be “false positive”, many of them seriously so. Twenty-one percent of the erroneously high results (1.8% of all results) were potentially misleading and were corrected by blocking reagent, although 49% of such seriously high results (4.2% of all results) were not. A further 39% of the false-positive results (2.6% of all results) would not necessarily have appeared likely to produce adverse clinical consequences but were substantially lowered by the addition of the blocking reagent.Conclusions: Random errors can occur with all types of immunoassays tested and can be difficult to identify even when repeated in another laboratory. Clinicians need to be aware of these limitations.
Wrong Biochemistry Results: Two Case Reports and Observational Study in 5310 Patients on Potentially Misleading Thyroid-stimulating Hormone and Gonadotropin Immunoassay Results
Authors: Ismail Adel AA , Walker Paul L , Barth Julian H , Lewandowski Kryzsztof C , Jones Rick , Burr William A 
Published: January 2020

AbstractBackground: Immunoassays are used in almost all medical and surgical specialties, but they suffer from interference from proteins such as antibodies in some patients’ sera. Such interferences are usually reported in the literature only as case reports after the introduction of a new assay.Methods: We undertook a prospective observational study on 5310 patients for whom the common immunoassay tests for thyroid-stimulating hormone (TSH) and/or gonadotropins were requested. All TSH and gonadotropin results were critically assessed for a mismatch between the clinical details and analytical results to identify samples suspected of analytical unreliability. These were tested further by three approaches to screen for interference.Results: From the 5310 sets of results, 59 patients’ samples were identified as suspect and were tested further. Analytically incorrect results were found in 28 (0.53% of the total studied). The magnitude of interference varied, but in 23 of 28 patients (82%), it was considered large enough to have a potentially adverse effect on cost and/or the clinical care of these patients. Two cases, described in detail, illustrate the adverse effect of error on patient care and cost, and the second highlights the difficulties and limitations of current approaches for identifying interference and inaccuracy in immunoassays.Conclusions: Because millions of TSH/gonadotropin tests are carried out in UK hospital laboratories alone, our data suggest that thousands of patients could be adversely affected by errors from interferences. Early identification of interference in cases with unusual results could be valuable.
Pyrosequencing as an Alternative to Single-Strand Conformation Polymorphism Analysis for Detection of N-ras Mutations in Human Melanoma Metastases
Authors: Sivertsson Åsa , Platz Anton , Hansson Johan , Lundeberg Joakim 
Published: January 2020

AbstractBackground: Mutations in codons 12, 13, and 61 of the N-ras gene are common alterations in cutaneous malignant melanoma. We evaluated pyrosequencing, a simple and rapid method used mainly for single-nucleotide polymorphism analysis, as a possible alternative to single-strand conformation polymorphism (SSCP) analysis and sequencing of N-ras.Methods: We evaluated the sensitivity and accuracy of the pyrosequencing method for identification of mutations in N-ras codons 12, 13, and 61. Nucleotide dispensation orders were created to produce distinct pyrogram peak profiles for the most frequent mutations in codon 61 and codons 12 and 13, respectively.Results: The detection limits for the two most common codon 61 mutations found in malignant melanoma, which code for Arg and Lys, were 30% and 15%, respectively. To evaluate the pyrosequencing method on clinical samples, we performed a parallel analysis of 82 melanoma metastases using SSCP analysis and pyrosequencing. All mutations detected by SSCP analysis and confirmed by sequencing were also correctly identified by pyrosequencing. Codon 61 mutations were identified in 26 of the 82 samples (32%), whereas no mutations were found in codons 12 and 13. Four types of codon 61 mutations, Arg (17%), Lys (10%), Leu (4%), and His (1%), were identified.Conclusion: Pyrosequencing is an attractive alternative to SSCP analysis for N-ras mutation detection in malignant melanoma tumor samples because it displays the same sensitivity and accuracy as SSCP analysis and is simple and rapid.
Detection of Specific Antinuclear Reactivities in Patients with Negative Anti-nuclear Antibody Immunofluorescence Screening Tests
Authors: Hoffman Ilse EA , Peene Isabelle , Veys Eric M , De Keyser Filip 
Published: January 2020

Abstract
Background: For detection of anti-nuclear antibodies (ANAs) and antibodies to extractable nuclear antigens (ENAs), samples frequently are screened with indirect immunofluorescence (IIF); further determination of anti-ENA antibodies is performed only when the result is positive. However, because anti-ENA reactivities are found in samples with low fluorescence intensities, we determined anti-ENA antibodies in samples with negative IIF and thus calculated the sensitivity of IIF for specific ANAs.
Methods: We collected 494 samples consecutively referred by rheumatologists for routine ANA testing. IIF on HEp-2 and HEp-2000 (HEp-2 cells transfected with Ro60 cDNA) and line immunoassay (LIA) for the detection of specific ANAs were performed on all samples.
Results: Fluorescence intensities and patterns on HEp-2 were strongly correlated with those on HEp-2000 [Spearman ρ = 0.852 (P &lt;0.001) and 0.838 (P &lt;0.001), respectively]. Sixty-eight of 494 samples were positive on LIA, of which only 72% (confidence interval, 68–76%) were detected with HEp-2 and 75% (confidence interval, 70–78%) with HEp-2000. Of 291 samples negative on both substrates, 12 were positive on LIA. Connective tissue diseases were diagnosed in four of these patients and suspected in at least three others.
Conclusion: The HEp-2 and HEp-2000 substrates perform comparably for fluorescence intensities and patterns and for detecting specific ANAs, but some patients with negative IIF show reactivity on LIA. We recommend testing for fine reactivities, regardless of the IIF result, when the clinical suspicion for rheumatic connective tissue disease is high.
Carbohydrate-deficient Transferrin Isoforms Measured by Capillary Zone Electrophoresis for Detection of Alcohol Abuse
Authors: Legros Franz J , Nuyens Vincent , Minet Eddy , Emonts Philippe , Boudjeltia Karim Zouaoui , Courbe Anne , Ruelle Jean-Luc , Colicis Jacques , de L’Escaille Francois , Henry Jean-Pol 
Published: January 2020

Abstract
Background: Measurements of carbohydrate-deficient transferrin (CDT) are used as markers of alcohol abuse. We developed a capillary zone electrophoresis (CZE) method aimed at improving accuracy of CDT testing.
Methods: We studied 111 alcohol abusers with Alcohol Use Disorders Identification Test scores &gt;11 and 50 teetotalers. CZE was performed with a P/ACE 5500, fused-silica capillaries, and a CEofix CDT reagent set. After iron saturation, sera were loaded by low-pressure injection, separated at 28 kV, and monitored at 214 nm. We identified the transferrin isoforms by migration times, treatment with 100 U/L neuraminidase, and immunosubtraction with anti-human transferrin and anti-C-reactive protein antibodies. We compared CZE results with current biological markers of alcohol abuse, including the %CDT turbidimetric immunoassay.
Results: Migration times of the isoforms were identical in both populations. Asialotransferrin was missing in teetotalers but present in 92% of alcohol abusers. Disialotransferrin was higher in those who consumed excessive amounts of alcohol, whereas mean trisialotransferrin concentration was not affected by alcohol abuse. At cutoffs to maximize sensitivity and specificity, these values were 0.92 and 1 [mean ROC area (MRa), 0.96; 95% confidence interval (CI), 0.93–0.99] for asialotransferrin; 0.84 and 0.94 for the sum of asialo- + disialotransferrin (MRa, 0.94; 95% CI, 0.91–0.98); 0.79 and 0.94 for disialotransferrin (MRa, 0.89; 95% CI, 0.84–0.94); 0.62 and 0.53 for trisialotransferrin (MRa, 0.58; 95% CI, 0.49–0.68); 0.79 and 0.82 for a 3% %CDT; and 0.83 and 0.69 for a 2.6% cutoff (MRa, 0.87; 95% CI, 0.81–0.92). Current markers lack sensitivity (&lt;0.65). Transferrins were not significantly correlated with serum enzymes and mean erythrocyte volume.
Conclusions: CZE-isolated desialylated transferrin isoforms allowed differentiation between chronic alcohol abusers and teetotalers.
Quantitative Evaluation of Urinalysis Test Strips
Authors: Penders Joris , Fiers Tom , Delanghe Joris R 
Published: January 2020

AbstractBackground: Urine test strip results are generally reported in categories (i.e., ordinal scaled), but automated strip readers are now available that can report quantitative data. We investigated the possible use of these meters to complement flow cytometry of urine and compared reflectance readings with quantitative determinations of urinary glucose and microalbumin.Methods: We compared URISYS 2400 (Roche) quantitative reflectance data with data from the UF-100 (Sysmex) and biochemical data for 436 nonpathologic and pathologic urine samples.Results: Reproducibility of the reflectance signal was good for high- and low-concentration urine pools for protein (0.8% and 0.9% and 1.5% and 2.2% within and between runs, respectively), leukocyte esterase (1.1% and 1.0%; 5.1% and 1.2%), hemoglobin (1.7% and 1.1%; 8.9% and 1.1%) and glucose (2.1% and 0.5%; 6.5% and 2.3%). Fair agreement was obtained between UF-100 and test strip reflectance data for erythrocytes and hemoglobin (r = −0.680) and leukocytes and leukocyte esterase (r = −0.688). Higher correlations were observed for biochemical and test strip data comparing protein and albumin (r = −0.825) and glucose data (r = −0.851). The lower limits of detection for erythrocytes and leukocytes were 8 × 106/L and 19 × 106/L, respectively. The protein test (n = 220) detected 86% (95% confidence interval, 78–92%) of samples with &lt;30 mg/L albumin with a specificity of 84% (95% confidence interval, 76–91%).Conclusions: In urine test strip analysis, quantitative hemoglobin and leukocyte esterase reflectance data are complementary with flow cytometric results and glucose and albumin results.
Insulin: Discovery and Controversy
Authors: Rosenfeld Louis 
Published: January 2020

AbstractDuring the first two decades of the 20th century, several investigators prepared extracts of pancreas that were often successful in lowering blood sugar and reducing glycosuria in test animals. However, they were unable to remove impurities, and toxic reactions prevented its use in humans with diabetes. In the spring of 1921, Frederick G. Banting, a young Ontario orthopedic surgeon, was given laboratory space by J.J.R. Macleod, the head of physiology at the University of Toronto, to investigate the function of the pancreatic islets. A student assistant, Charles Best, and an allotment of dogs were provided to test Banting’s hypothesis that ligation of the pancreatic ducts before extraction of the pancreas, destroys the enzyme-secreting parts, whereas the islets of Langerhans, which were believed to produce an internal secretion regulating sugar metabolism, remained intact. He believed that earlier failures were attributable to the destructive action of trypsin. The name “insuline” had been introduced in 1909 for this hypothetic substance. Their experiments produced an extract of pancreas that reduced the hyperglycemia and glycosuria in dogs made diabetic by the removal of their pancreases. They next developed a procedure for extraction from the entire pancreas without the need for duct ligation. This extract, now made from whole beef pancreas, was successful for treating humans with diabetes. Facilitating their success was a development in clinical chemistry that allowed blood sugar to be frequently and accurately determined in small volumes of blood. Success with purification was largely the work of J.B. Collip. Yield and standardization were improved by cooperation with Eli Lilly and Company. When the Nobel Prize was awarded to Banting and Macleod for the discovery of insulin, it aggravated the contentious relationship that had developed between them during the course of the investigation. Banting was outraged that Macleod and not Best had been selected, and he briefly threatened to refuse the award. He immediately announced that he was giving one-half of his share of the prize money to Best and publicly acknowledged Best’s contribution to the discovery of insulin. Macleod followed suit and gave one-half of his money award to Collip. Years later, the official history of the Nobel Committee admitted that Best should have been awarded a share of the prize.