bluuebunny/crossref_metadata_2025_split huggingface dataset:
Serial lecithin/sphingomyelin ratios and surfactant/albumin ratios in tracheal aspirates from term infants with respiratory failure receiving extracorporeal membrane oxygenation
Authors: Lotze A , Stroud C Y , Soldin S J 
Published: January 2020

Abstract
Serial tracheal aspirate samples were obtained for determination of lecithin/sphingomyelin (L/S) ratios from 47 term infants in respiratory failure. Phospholipids were extracted with Folch solution (chloroform:methanol, 2:1 by vol) and analyzed by HPLC with use of silica column and a mobile phase of acetonitrile:methanol:water (48:31:21, by vol). Surfactant/albumin (S/A) ratios were determined with the TDx Fetal Lung Maturity Assay (Abbott Labs). L/S ratios increased significantly over time in all patients (F = 19.42, P &lt; 0.0001). The S/A ratio correlated with the L/S ratio (r = 0.554, P &lt; 0.001). This study suggests that postnatal surfactant deficiency in term newborns with respiratory failure is a component of the newborn's lung injury.
Clinical Utility of Biochemical Analysis of Cerebrospinal Fluid
Authors: Watson Mark A , Scott Mitchell G 
Published: January 2020

Abstract
In the Review by Watson and Scott entitled "Clinical utility of biochemical analysis of cerebrospinal fluid," 1995; 41:343-60, the total protein concentration in Table 1 should have been expressed in grams per liter (g/L), not milligrams per liter.
In the Case Report by S. Coyle, M.D. Penney, P.W. Masters, and B.E. Walker entitled "Early diagnosis of ectopic arginine vasopressin secretion." 1933;39:152-4, in column 2, paragraph 3, page 152, and the title of The 1, the concentration of hypertonic saline infusion should have been expressed as 50 grams per liter (g/L), not milligrams per liter.
Clinical laboratory consultation
Authors: Burke M D 
Published: January 2020

Abstract
The future of healthcare delivery systems will depend on their ability to provide the best care at the least cost. In the clinical laboratory, this translates to ensuring that decreased test use means appropriate use. The latter is unlikely to occur unless clinical laboratories provide practicing physicians with advice on test strategy and interpretation of results. Effective clinical laboratory consultation requires an identification with clinical problems. Important components of the identification process are an appreciation of the probabilistic rather than deterministic nature of the relation of clinical and laboratory data to disease and the inevitable tradeoff between false negatives and false positives that clinical circumstances demand. Institution of consultation services requires that the clinical laboratory adopt a proactive approach to advocating test strategy and interpreting results. Consultation on test strategy is likely to be facilitated by further developments in practice guidelines and by advances in informatics and telemedicine.
Low plasma concentrations of retinol-binding protein in individuals with mutations affecting position 84 of the transthyretin molecule
Authors: Waits R P , Yamada T , Uemichi T , Benson M D 
Published: January 2020

Abstract
Retinol-binding protein (RBP), the principal carrier for vitamin A, is known to form a complex with transthyretin (TTR) for transport in plasma. Individuals from a kindred with the amino acid substitution of serine for isoleucine at position 84 (Ser84) of the TTR molecule show substantial reduction in plasma concentrations of RBP. In the present study, we measured plasma RBP in individuals from several kindreds, demonstrating 17 different point mutations within the TTR gene. In each case, these mutations caused single amino acid substitutions at various positions throughout the TTR molecule. Of all the individuals examined, only those with mutations causing amino acid substitutions at position 84 of the TTR molecule (Ser84 and Asn84) demonstrated substantial decreases in plasma concentrations of RBP. These results suggest that the isoleucine at position 84 on the TTR molecule may be critically involved in mediating RBP binding. Further, these findings demonstrate the importance of considering TTR gene mutations when clinically evaluating patients with low RBP.
HPLC-microparticle enzyme immunoassay specific for tacrolimus in whole blood of hepatic and renal transplant patients
Authors: Firdaous I , Hassoun A , Otte J B , Reding R , Squifflet J P , Besse T , Wallemacq P E 
Published: January 2020

Abstract
Tacrolimus is a relatively new immunosuppressant used in organ transplantation to prevent graft rejection. However, its use is not devoid of side effects, making it important to maintain blood concentrations within therapeutic ranges. Several analytical methods are currently available for routine drug monitoring. However, these methods are based on use of the same monoclonal antibody, which also cross-reacts with some metabolites, resulting in overestimation of some blood concentrations. Even though this antibody appears appropriate for therapeutic drug monitoring, no reference method measures only the parent drug, mainly because of the poor absorptivity of tacrolimus in ultraviolet light. We have developed a method displaying an increased specificity towards the unchanged drug, using conventional equipment available in most clinical laboratories. After chromatographic separation of the blood extract, the tacrolimus fraction is analyzed by an automated microparticle enzyme immunoassay (MEIA) performed on the IMx analyzer (Abbott Labs.). This method is linear from 0 to 40 micrograms/L, yields CVs from 8.5% to 18.2%, and has a detection limit of 5 micrograms/L. Tacrolimus concentrations obtained by HPLC-MEIA in hepatic and renal transplant patients are from 47.5% to 18.8% lower than those obtained by MEIA, according to liver function tests and metabolite accumulation, even though no significant differences were observed between the methods for drug-free blood samples supplemented with known amounts of tacrolimus.
Measurement of urinary oxalate and citrate by capillary electrophoresis and indirect ultraviolet absorbance
Authors: Holmes R P 
Published: January 2020

Abstract
We describe a method for measuring urinary oxalate and citrate with capillary electrophoresis (CE) and indirect ultraviolet absorbance detection. Sample preparation is minimal, requiring an acidification, brief centrifugation, and dilution. The method is rapid, with oxalate and citrate having mean migration times of 4.02 and 4.50 min, respectively. The minimal detectable concentration (signal-to-noise ratio of 7) of both oxalate and citrate in urine was 7 mg/L. Total imprecisions (CV) were 1.2-5.6% for three urine samples with oxalate and citrate concentrations of 8-60 mg/L and 80-860 mg/L, respectively. The recovery of added oxalate ranged from 94% to 101%. Results of CE analyses agreed well with enzymatic determinations of oxalate and citrate. Rapid analysis time, accuracy, and reproducibility make this procedure well suited for routine urinary oxalate and citrate determinations.
History of NIST's contributions to development of standard reference materials and reference and definitive methods for clinical chemistry
Authors: Schaffer R , Bowers G N , Melville R S 
Published: January 2020

Abstract
The issuance of cholesterol as a Standard Reference Material (SRM) in 1967 started the National Institute of Standards and Technology (NIST; then named the National Bureau of Standards) on a major effort to help clinical laboratories establish and improve the quality of measurements they make. NIST now issues three kinds of SRMs for that purpose: analyte samples of certified purity as primary standards, serum samples having certified analyte concentrations as accuracy controls, and materials certified for calibrating instruments. In working with clinical laboratory scientists to establish Reference Methods (RMs) for measuring the analytes, NIST developed Definitive Methods (DMs) to use for evaluating RM accuracy and then used the DMs for assigning analyte values to its SRMs. The development of SRMs and DMs is discussed.
Development and implementation of an expert information system (BRITE) used in technical support of medical diagnostics customers
Authors: Hopkins T , Advani R , Gudmunson G 
Published: January 2020

Abstract
We developed BRITE (Bringing Resources and Information to Employees), an expert information retrieval system, for problem solving and retrieving technical product information. Specialists in our Technical Assistance Center (TAC) use the BRITE system on a Pentium workstation to access information in &lt; 3 s. Manuals, technical bulletins, parts lists, and administrative tools such as word processing and network fax are available electronically. The system allows consistent troubleshooting and definition of customers' problems by TAC specialists. BRITE seamlessly integrates expert system, document retrieval, and relational database technologies; the system runs on a token ring local area network, which is part of a Ciba Corning Diagnostics wide area network. Information received over the wide area network is used to develop and update BRITE daily. BRITE is kept current by input or troubleshooting and new applications from TAC specialists.
Laboratory computing--process and information management supporting high-quality, cost-effective healthcare
Authors: Buffone G J , Moreau D R 
Published: January 2020

Abstract
One currently observes many healthcare institutions rushing to reengineer and install information systems with the expectation of achieving enhanced efficiency, competitiveness, and, it is hoped, higher patient satisfaction resulting from timely, high-quality care. Unfortunately, information system concepts, design, and implementation have not yet addressed the complexity of representing and managing clinical processes. As a result, much of the synergy one might expect to derive from understanding and designing clinical processes to gain efficiency and quality while maintaining humanness is not readily achievable by implementing traditional information systems. In this presentation, with laboratory services as an example, we describe a conceptually different information systems model, which we believe would aid care-givers in their efforts to deliver compassionate, quality care while addressing the highly competitive nature of market-driven healthcare.
BibleCard: network-based virtual database for laboratory information
Authors: Fine J S , Ching A K , Schneider J B , Pollum D , Astion M L 
Published: January 2020

Abstract
The clinical laboratory's use of computers has evolved beyond the single minicomputer stand-alone system. Our laboratory information system is now part of an institutional network. The laboratory also uses smaller systems and workstations for a wide variety of functions, often with much data duplication among systems. We have been developing a network-based virtual database for laboratory test information. This system uses World Wide Web standards for hypertext and multimedia displays, which allows for the display of information retrieved from various department computer sources without the necessity of data duplication, modification of existing systems, or centralization of data. The medical technologists can continue to write testing procedures on their word processors. Maintenance of reference values, specimen requirements, etc., can continue as a laboratory information system function. Yet information from all of these disparate sources can be viewed in a consolidated format that has platform independence.
Analyte detection with DNA-labeled antibodies and polymerase chain reaction
Authors: Joerger R D , Truby T M , Hendrickson E R , Young R M , Ebersole R C 
Published: January 2020

Abstract
We demonstrate immuno-polymerase chain reaction (PCR) assays for two clinical analytes--human thyroid-stimulating hormone and chorionic gonadotropin (hTSH, hCG)--using DNA-labeled antibodies and PCR for amplification of assay response. DNA-antibody conjugates were synthesized by using heterobifunctional cross-linker chemistries to covalently attach single- or double-stranded DNA labels through amine or sulfhydryl groups on the analyte antibodies. These approaches yielded molecular chimeras possessing both analyte-specific antibody binding and nucleic acid amplification functionalities. Dose-response relationships were demonstrated for immuno-PCR assays of both analytes in a microtiter plate-based, two-antibody sandwich assay format. Detection limits for hTSH (1 x 10(-19) mol, &lt; 1.4 mIU/L) and hCG (5 x 10(-18) mol, 0.025 IU/L) exceeded those of conventional enzyme immunoassays by 2-3 orders of magnitude. We also evaluated various DNA design factors influencing label amplification and assay performance, such as primer sequence, strand number, and DNA length. Our findings, in concert with previous reports, suggest that this hybrid technology could provide the basis for a new generation of ultra-sensitive immunoassays offering multianalyte capabilities.
Solution-phase immunoassay for determination of cortisol in serum by capillary electrophoresis
Authors: Schmalzing D , Nashabeh W , Fuchs M 
Published: January 2020

Abstract
We describe a competitive solution-phase immunoassay for serum cortisol determination that involves capillary electrophoresis (CE) combined with laser-induced fluorescence for separation and quantification. A polyclonal antibody preparation and fluorescein-labeled cortisol are used as assay reagents. 8-Anilino-1-naphthalenesulfonic acid was added to the serum sample during the assay to promote the release of cortisol from endogenous binding proteins. Conditions for the rapid separation of free and bound labeled antigen by CE were developed. Aspects of assay performance are evaluated in this report. The resulting assay protocol allows for the analysis of serum samples without extraction or other sample preparation steps.
Physiological variations in thyroid hormones: physiological and pathophysiological considerations
Authors: Fisher D A 
Published: January 2020

Abstract
Thyroid hormone production is regulated via pituitary thyrotropin (TSH) modulation of thyroxine (T4) prohormone secretion by the thyroid gland and regulation of active triiodothyronine (T3) production in peripheral tissues via metabolic events influencing activities of the iodothyronine monodeiodinase enzyme systems. Control at both levels is developmentally regulated and modified in serious nonthyroidal illness (trauma, infection, cancer, metabolic diseases). Racial and gender differences are of little significance except for the effects of placental estrogens and chorionic gonadotropin during pregnancy. There is a circadian rhythm of TSH secretion, with peak values at the onset of sleep and nadir concentrations during the afternoon hours. Peak and nadir concentrations differ by approximately +/- 50%. The effect on circulating T4 and T3 concentrations is not significant because of the large size of the extrathyroidal T4 pool. In healthy subjects there is no significant impact of body weight, physical training, body habitus, posture, immobilization, exercise, or ambulatory status on thyroid function, and no significant geographic environmental variation. Nutrition also has a minimal impact except for variation in iodine intake. Subthreshold concentrations of iodine intake are associated with increased TSH secretion, goiter, increased thyroid iodine uptake, decreased T4 production, an increased T3/T4 secretion ratio, and an increased ratio of circulating T3/T4 concentrations. Excessive iodine intake can block thyroid hormone biosynthesis by inhibiting the enzymes involved in the biosynthetic process, resulting in reduced T4 secretion, increased TSH concentrations, goiter, and hypothyroidism if the iodine excess is chronic.
Analytical performance of free and total thyroxine assays
Authors: Nelson J C , Wilcox R B 
Published: January 2020

Abstract
Excessive bias and imprecision are major analytical problems associated with some assays for free and total thyroxine (T4). Bias in free T4 methods is largely proportional to variations in serum T4 binding. In direct methods, this is attributable to requirements for substantial quantities of protein-bound T4 to replace analytical losses of free T4. In some total T4 methods, bias is inversely proportional to the amount of serum T4 binding and is attributable to the incomplete release of serum protein-bound T4. In others, bias is fixed and attributable to inaccurate calibration. Manufacturers should report the bias in their methods. Calibrations should be standardized. Imprecision varies widely among methods, but is generally less for total T4 methods than for free T4 methods. A consensus on quantitative analytical performance goals for free and total T4 methods would be helpful. Here, performance goals are proposed, based in part on the best achievements of current methods.
Clinical usage recommendations and analytic performance goals for total and free triiodothyronine measurements
Authors: Klee G G 
Published: January 2020

Abstract
The major clinical role for total triiodothyronine (TT3) and (or) free T3 (FT3) is the assessment of hyperthyroidism in patients with suppressed sensitive thyrotropin (sTSH) concentrations. The assays are particularly important in hyperthyroid patients with normal free thyroxine (FT4) concentrations to assess potential T3 thyrotoxicosis. Other specialized uses for T3 and FT3 measurements are monitoring thyroid hormone replacement therapy, the evaluation of amiodarone-induced thyrotoxicosis, and predicting outcome of antithyroid drug therapy in patients with Graves hyperthyroidism. The roles of these tests in assessing heart function in cardiopulmonary bypass surgery, evaluation of patients with neuropsychiatric disorders, and monitoring of patients on anticonvulsant therapy are not well defined. These assays are not recommended for diagnosis of hypothyroidism. Analytic recommendations include CV &lt; 5.2% for T3 and &lt; 3.8% for FT3; &lt; 0.2% cross-reactivity with L-T4; and &lt; 1.0% cross-reactivity with D-T4, D-T3, and reverse T3.
Current status and performance goals for serum thyroglobulin assays
Authors: Spencer C A , Takeuchi M , Kazarosyan M 
Published: January 2020

Abstract
Serum thyroglobulin (Tg) measurements are used as a tumor marker for monitoring patients with differentiated thyroid carcinoma. The clinical utility of six different Tg methods [RIA or immunometric assay (IMA)] currently used in Europe and the US was evaluated, with focus on methodologic standardization, sensitivity, interassay precision across the typical clinical monitoring interval (6 to 12 months), "hook" effects (IMA methods), and Tg autoantibody interference. The methods evaluated were: DYNOtest Tg (Henning), OptiQuant Tg (Kronus), SELco Tg (Medipan), Thyroglobulin IRMA (Pasteur), Nichols Chemiluminescent ICMA (Corning Nichols), and an RIA developed by us (USC Endocrine Services Laboratory). The clinical impact of the current methodologic problems on the use of serum Tg measurements is reviewed. Optimal performance goals are recommended for manufacturers developing and laboratories and physicians selecting a serum Tg method to use for serial long-term monitoring of thyroid cancer patients.
Modern concepts of primary thyroid gland failure
Authors: Ridgway E C 
Published: January 2020

Abstract
Primary thyroid gland failure is a common medical disorder occurring in mild or severe forms in 10% to 15% of our population. Symptoms may be classical and easy to recognize or very subtle, escaping clinical detection. This disorder is more common in females and increases with advancing age. The most important diagnostic test is measurement of the serum thyrotropin (TSH) concentration, which will increase above the normal range in both mild and severe cases. Most clinical effects of thyroid hormone deficiency can be explained by the "nuclear thyroid hormone hypothesis," which states that thyroid hormones act predominantly by effecting the transcription of key genes in affected tissues. Therapy of hypothyroidism is easy, inexpensive, and precise, involving pure L-thyroxine and measuring dose requirements and efficacy by monitoring serum TSH concentrations.
Blood glutathione concentrations in a large-scale human study
Authors: Richie J P , Skowronski L , Abraham P , Leutzinger Y 
Published: January 2020

Abstract
Little is known about the variability of blood glutathione (GSH) in human subjects. Thus, we wanted to develop and validate a rapid method for measuring GSH concentrations in whole blood and apply this method to ascertain the variation of GSH in a large-scale study of free-living adults. The assay was highly sensitive (detection limit &lt; 5 pmol) and precise, with an interassay variation of 2.3% and a sampling variation of 3.6%. Applying this method to screen 715 adults, we observed a threefold range of GSH concentrations, with a mean of 1.02 mmol/L and CV of 17%. GSH concentrations were 8-10% greater in smokers than in nonsmokers (P &lt; 0.001). Although we observed no sex differences for GSH, GSH/hemoglobin ratios were 8-18% greater in women &lt; 55 years old than in older subjects (P &lt; 0.05). The results presented here validate the use of this method for large-scale human studies and provide information on the variation and normal values of blood GSH in adults.
Logical observation identifier names and codes (LOINC) database: a public use set of codes and names for electronic reporting of clinical laboratory test results
Authors: Forrey A W , McDonald C J , DeMoor G , Huff S M , Leavelle D , Leland D , Fiers T , Charles L , Griffin B , Stalling F , Tullis A , Hutchins K , Baenziger J 
Published: January 2020

Abstract
Many laboratories use electronic message standards to transmit results to their clients. If all laboratories used the same "universal" set of test identifiers, electronic transmission of results would be greatly simplified. The Logical Observation Identifier Names and Codes (LOINC) database aims to be such a code system, covering at least 98% of the average laboratory's tests. The LOINC database should be of interest to hospitals, clinical laboratories, doctors' offices, state health departments, governmental healthcare providers, third-party payors, organizations involved in clinical trials, and quality assurance and utilization reviewers. The fifth release of the LOINC database, containing codes, names, and synonyms for approximately 6300 test observations, is now available on the Internet for public use. Here we describe the LOINC database, the methods used to produce it, and how it may be obtained.
Detection of Mycobacterium tuberculosis DNA with thermophilic strand displacement amplification and fluorescence polarization
Authors: Walker G T , Linn C P 
Published: January 2020

Abstract
Strand displacement amplification (SDA) is an isothermal, in vitro method for diagnostics that amplifies a target DNA sequence by using a restriction enzyme and DNA polymerase. We have combined a new thermophilic form of SDA that involves restriction enzyme BsoBI and polymerase exo-Bca with fluorescence polarization for detection of Mycobacterium tuberculosis DNA by using the IS6110 insertion element as the target sequence. A 5'-fluorescein-labeled oligodeoxynucleotide detector probe hybridizes to the amplified product as it rises in concentration during SDA, and the single- to double-stranded conversion is monitored through an increase in fluorescence polarization. The associated change in polarization upon amplification of the target sequence is enhanced by specific polymerase binding to the double-stranded detector probe. Fewer than 10 M. tuberculosis genomes can be amplified and detected with an extremely simple protocol that takes only 20 min and uses relatively simple instrumentation and reagents, all of which can be purchased off-the-shelf.