bluuebunny/crossref_metadata_2025_split huggingface dataset:
Measuring outcomes: why now?
Authors: Witte D L 
Published: January 2020

Abstract
Intense scrutiny of the American healthcare paradigm will alter the activities of patients, providers, and payors. Government reform and marketplace-driven managed care programs create uncertainty. Quality, access, and cost concerns also drive change. Quality is conformity to requirements, and specification of requirements creates policy debate. Variability in utilization creates an accountability chasm between payors and providers that cannot be bridged without understanding the uncertainties in "appropriateness" research. Quality and access appear secondary to cost. Cost discussions must differentiate cost and charge. Inappropriate charge benefit analyses may temporarily benefit a specific organization but are unlikely to create long-term societal benefit. Multiple transitions have begun, including a shift from disease care to healthcare, provider mentality to consumer mentality, and provider autonomy to collaboration and accountability. Laboratories will be expected to provide outcomes, not tests; income will be related to covered lives, not volume, and profit will shift from "piecework and efficiency profit" to "prevention profit." Only good "outcomes" measurement can reduce uncertainty. The laboratory contribution to value in care processes remains unclear. What information is added by each result? How can results help prevent the need for future services? These are our challenges.
Diagnostic information as a commodity
Authors: Johnson H A 
Published: January 2020

Abstract
In estimating the cost-effectiveness of diagnostic procedures, it is helpful to treat diagnostic information as a commodity with a unit price. The amount of useful information provided by a test result can be measured in binary units (bits), and the unit price of the information produced by the test result can be expressed in dollars per bit in much the same way that the price of gold is given in dollars per ounce. This allows comparison of the unit prices of various diagnostic tests, examination of the effect of multiple testing, and calculation of the most cost-effective conditions for screening tests.
Conducting outcomes research: past experience and future directions
Authors: Boone D J , Steindel S J 
Published: January 2020

Abstract
The Centers for Disease Control and Prevention (CDC) was delegated authority to conduct the studies mandated in the Clinical Laboratory Improvement Amendments of 1988 (CLIA). Since that time, the CDC has been planning and implementing a research program, Evaluation of Quality of Laboratory Practices and Standards (EQLPS), aimed at demonstrating a clear linkage between patient outcome and laboratory practices and standards such as proficiency testing, quality assurance, and personnel standards. The goal of EQLPS is to improve the quality of laboratory medicine by providing a scientific and technical basis for laboratory practices and standards. In October 1995, the CDC will sponsor an Institute entitled "Frontiers in Laboratory Practice Research," during which strategies for conducting laboratory practice research will be discussed. The Institute should help identify research strategies that will eventually provide the information necessary to develop appropriate practice guidelines for laboratory medicine.
Structural analysis of CFTR gene in congenital bilateral absence of vas deferens
Authors: Jézéquel P , Dorval I , Fergelot P , Chauvel B , Le Treut A , Le Gall J Y , Le Lannou D , Blayau M 
Published: January 2020

Abstract
Congenital bilateral absence of the vas deferens (CBAVD) is found in most males with cystic fibrosis (CF), but this malformation can be observed without any pulmonary or digestive features. We have analyzed 13 exons of the CF gene in a cohort of 25 CBAVD patients. Among the 50 chromosomes studied, 24 mutations were identified: delta F508 (14 cases), R117H (7 cases), R1070W (2 cases), 621 + 1 G --&gt; T (1 case), and A1067V (1 case). Except for delta F508, the most frequent mutations (R117H, R1070W) were not observed in the CF group (109 patients) studied in our laboratory. We discuss the significance of these results.
Prognostic role of antioxidant enzymes in sepsis: preliminary assessment
Authors: Warner A , Bencosme A , Healy D , Verme C 
Published: January 2020

Abstract
The prognostic potential of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) was evaluated in sepsis. Enzyme concentrations were determined in samples obtained from septic patients at time of diagnosis. Statistically significant increases in activities of total plasma SOD (P &lt; 0.003, n = 32), erythrocyte (RBC) SOD (P &lt; 0.007, n = 16), plasma CAT (P &lt; 0.0001, n = 32), and RBC CAT (P &lt; 0.005, n = 16) were found in septic patients when compared with healthy adult controls (n = 7). Further, within the group of septic patients, statistically significant differences were found for total plasma SOD (P &lt; 0.05) and plasma CAT (P &lt; 0.009) (but not for RBC determinations) when survivors (n = 15) were compared with nonsurvivors (n = 17). No significant differences were found for either plasma or RBC enzyme concentrations when patients who developed adult respiratory distress syndrome were compared with those who did not. The most striking finding was that plasma total SOD values of &gt; 10 kU/L were found in 7 of 21 (30%) patients who did not survive their sepsis and that these values did not overlap with any surviving patients or controls. However, while high total plasma SOD activity appears to have some potential as a prognostic indicator, lower values (0.0-8.8 kU/L) do not. For plasma CAT, despite finding statistically significant differences between survivors and nonsurvivors, the substantial overlap in the values obtained for the two groups limits the practical prognostic potential of this enzyme.
Nitrite and nitrate determinations in plasma: a critical evaluation
Authors: Moshage H , Kok B , Huizenga J R , Jansen P L 
Published: January 2020

Abstract
Plasma nitrite and nitrate determinations are increasingly being used in clinical chemistry as markers for the activity of nitric oxide synthase and the production of nitric oxide radicals. However, a systematic evaluation of the determination of nitrite and nitrate in plasma has not been performed. In this study the recovery and stability of nitrite and nitrate in whole blood and in plasma, the relation between nitrite and nitrate concentrations in plasma, and possible sources of artifacts were investigated. The main conclusions are: (a) Recovery of nitrite and nitrate from plasma is near-quantitative (87%) and reproducible; (b) nitrite and nitrate are stable in (frozen) plasma for at least 1 year; (c) nitrite in whole blood is very rapidly (&gt; 95% in 1 h) oxidized to nitrate, and therefore plasma nitrite determination alone is meaningless; (d) the ranges of nitrite and nitrate concentrations in plasma samples of 26 healthy persons are 1.3-13 mumol/L (mean 4.2 mumol/L) and 4.0-45.3 mumol/L (mean 19.7 mumol/L), respectively; (e) plasma nitrite and nitrate concentrations were not correlated (nitrite as % of total nitrite + nitrate varied from 3.9% to 88% in plasma samples); and (f) plasma samples should be deproteinized, and background controls for each sample should be included in the assay, to avoid measuring artifactually high nitrite and nitrate concentrations in plasma.
Determination of total serum sulfite by HPLC with fluorescence detection
Authors: Ji A J , Savon S R , Jacobsen D W 
Published: January 2020

Abstract
An estimated 500,000 individuals in the US, mostly steroid-dependent asthmatics, suffer severe adverse reactions to sulfites in foods, beverages, and pharmaceutical products. In an attempt to understand the pathogenesis of sulfite hypersensitivity, we have developed an assay for the determination of total serum sulfite by utilizing: (a) reductive release of serum protein-bound sulfite; (b) derivatization of free sulfite with monobromobimane; (c) separation of sulfite-bimane from thiol-bimanes by reversed-phase HPLC; and (d) quantitation of sulfite-bimane by fluorescence detection. The detection limit of this assay was 0.44 mumol/L serum sulfite. The intra- and interassay CVs for total serum sulfite at 5.4 mumol/L were 8.1% and 22.0%, respectively. The standard addition method was used to determine total serum sulfite in normal subjects. More than 70 samples were prepared in 2-3 h, followed by automated overnight analysis. The mean concentrations (+/- SD) of total serum sulfite in female (n = 41) and male (n = 35) donors were 4.63 +/- 2.33 and 5.16 +/- 2.68 mumol/L, respectively (not statistically significant: P = 0.368). The combined mean concentration of total sulfite in both sexes was 4.87 +/- 2.49 mumol/L. There was no correlation between total serum sulfite and total serum cysteine, cysteinylglycine, homocysteine, subject age, serum cobalamin, or serum folic acid. The reference range (mean +/- 2 SD) for total serum sulfite in normal subjects is 0-9.85 mumol/L.
Accumulation of atherogenic remnants and lipoprotein(a) in the nephrotic syndrome: relation to remission of proteinuria
Authors: Joven J , Simó J M , Vilella E , Camps J , Espinel E , Villabona C 
Published: January 2020

Abstract
Although lipoprotein abnormalities of the nephrotic syndrome are assumed to be related to the presence of proteinuria, this topic has not been investigated extensively. We measured lipoproteins from 19 nonuremic patients during and after remission of the nephrotic syndrome in an effort to determine the extent of their putative atherogenicity. As expected, disturbances involved primarily the apoprotein B-containing lipoproteins. No patient showed serum lipoprotein(a) [Lp(a)] &lt; 300 mg/L during the acute phase. Lp(a) concentrations correlated significantly with those of apoprotein B, and both values decreased dramatically with the remission of the nephrotic syndrome. Surprisingly, despite the resolution of proteinuria, concentrations of intermediate-density lipoproteins and Lp(a) remained above normal in hypertriglyceridemic patients, suggesting a residual effect of nephrosis in the overall lipoprotein transport. Accumulation of atherogenic remnants should be considered a characteristic of the hyperlipidemia of the nephrotic syndrome, and aggressive treatment to reduce proteinuria is mandatory.
Immunospecific scintillation proximity assay of cholesteryl ester transfer protein activity
Authors: Lagrost L , Loreau N , Gambert P , Lallemant C 
Published: January 2020

Abstract
We describe a novel, immunospecific scintillation proximity assay for determining cholesteryl ester transfer protein (CETP) activity in total human serum and in reconstituted experimental mixtures. The assay is based on the measurement of radiolabeled cholesteryl esters transferred from a tracer dose of biosynthetically labeled high-density lipoprotein subfraction 3 to unlabeled apolipoprotein (apo) B-containing lipoproteins. The radioactivity content of the apo B-containing lipoprotein fraction can be evaluated without separating the donor from the acceptor lipoprotein substrates, and is measured through the formation of ternary complexes involving the radiolabeled apo B-containing lipoproteins, specific anti-apo B antibodies from sheep, and anti-sheep antibody-labeled fluoromicrospheres. Good correspondences were observed between CETP activity values obtained either with the ultracentrifugation method or the immunospecific scintillation proximity assay (n = 70; r = 0.94; P = 0.0001), and between values obtained for either fresh or frozen serum samples (n = 70; r = 0.93; P = 0.0001). Because of its potential for automation, the immunospecific scintillation proximity assay may constitute a convenient tool to measure serum CETP activity in the clinical laboratory.
Effect of beta-glucuronidase on urinary benzodiazepine concentrations determined by fluorescence polarization immunoassay
Authors: Simonsson P , Lidén A , Lindberg S 
Published: January 2020

Abstract
In samples from patients treated with oxazepam, beta-glucuronidase increased the immunoreactivity of urinary benzodiazepines analyzed by fluorescence polarization immunoassay (FPIA). Increasing concentrations of beta-glucuronidase added to samples from drug-free controls did not influence the results. In the absence of beta-glucuronidase, 22 of 35 samples from patients undergoing detoxification gave positive results at a cutoff concentration of 200 micrograms/L. Pretreatment with beta-glucuronidase increased the number of drug-positive samples to 33. The drug-negative samples were obtained from two patients who had been oxazepam-free for at least 1 week. Thus, beta-glucuronidase can be used to increase the sensitivity of the urinary benzodiazepine FPIA without reducing the specificity of the method.
Vitamin E and vitamin A concentrations in plasma adjusted for cholesterol and triglycerides by multiple regression
Authors: Jordan P , Brubacher D , Moser U , Stähelin H B , Gey K F 
Published: January 2020

Abstract
The plasma concentration of vitamins A and E varies with the amount of concurrent lipids and thus requires lipid standardization. The present study compares a new multiple regression-based method for adjusting vitamins A and E concentrations for cholesterol and triglycerides with previous methods (adjustment for cholesterol only, and adjustment for the sum of cholesterol and triglycerides). The results show that the new method can reduce influence of the concurrent lipids.
Modified (desialylated) low-density lipoprotein measured in serum by lectin-sorbent assay
Authors: Tertov V V , Sobenin I A , Orekhov A N 
Published: January 2020

Abstract
Modified low-density lipoprotein (LDL) with a low sialic acid content was found in the blood of patients with coronary atherosclerosis. This desialylated lipoprotein causes lipid accumulation in arterial smooth-muscle cells and stimulates cell proliferation and production of the extracellular matrix, i.e., induces all atherogenic manifestations at the cellular level. We have developed a lectin-sorbent assay for the determination of desialylated LDL in sera. The assay is based on the binding of desialylated LDL by immobilized Ricinus communis agglutinin with subsequent measurement of lipoprotein through use of anti-apolipoprotein (apo) B antibody. The assay is sensitive to desialylated apo B concentrations as low as 5 micrograms/L. The intraassay and interassay CVs were 4.8% and 11.3%, respectively. Comparison between the lectin-sorbent assay and a lectin chromatographic technique showed a good correlation. This determination of modified desialylated LDL in human serum with high accuracy and reproducibility may help establish the diagnostic value of this lipoprotein as a risk factor of atherosclerosis.
Protocol for collection and HPLC analysis of volatile carbonyl compounds in breath
Authors: Lin Y , Dueker S R , Jones A D , Ebeler S E , Clifford A J 
Published: January 2020

Abstract
This noninvasive method for collection and analysis of a wide range of aldehydes and ketones in human breath may enable assessment of lipid peroxidation and metabolic status in vivo. Breath samples are drawn through silica cartridges impregnated with 2,4-dinitrophenylhydrazine, which traps carbonyls as their hydrazone derivatives. The hydrazone derivatives are eluted from the cartridges with acetonitrile, separated by reversed-phase HPLC, and quantified spectrophotometrically. Using this method, we have measured formaldehyde, acetaldehyde, acetone, propanal, 2-butanone, butanal, pentanal, and hexanal. Recoveries of carbonyls added to Douglas bags were &gt; 90%, except for 2-butanone, which was 86.2%. The overall CVs for sampling plus analyzing duplicate aliquots of breath were &lt; 11%. The results indicate that this protocol can be used to monitor changes of carbonyl production by analyzing expired air, which may, with further study, indicate physiological and pathological status.
Results of B-vitamin supplementation study used in a prediction model to define a reference range for plasma homocysteine
Authors: Ubbink J B , Becker P J , Vermaak W J , Delport R 
Published: January 2020

Abstract
Because high plasma concentrations of homocysteine constitute an enhanced risk for premature coronary heart disease, it is necessary to establish a reference range for normal concentrations of plasma homocysteine. The frequency distribution of plasma homocysteine concentrations tails to the right, and the nonparametric approach is unsatisfactory for defining a normal plasma homocysteine reference range. By using subjects' responses to appropriate vitamin supplementation, we developed a mathematical prediction model to calculate the plasma homocysteine concentration that could be expected for each individual treated with a vitamin supplement. With this model, we can predict that plasma homocysteine concentrations will approach a normal frequency distribution with a 95% reference range (mean +/- 2 SD) of 4.9-11.7 mumol/L, provided the vitamin status of the study population is improved.
Plasminogen activator activity and plasma-coagulum lysis measured by use of optimized fibrin gel structure preformed in microtiter plates
Authors: Sidelmann J , Jespersen J , Gram J 
Published: January 2020

Abstract
We introduce a new fibrin plate assay performed in microtiter plates. By means of spectroscopic studies we optimized the structure of the fibrin gel and then used the optimized fibrin gel to determine plasminogen activator activity. Plasminogen activator solutions were applied on top of the fibrin gel, and the absorbance of the gel was recorded at 405 nm. After incubation for 17 h at 25 degrees C, the absorbance was measured again. The difference in absorbance was proportional to the concentration of plasminogen activator, such that the dose-response curves were linear when the difference in absorbance was plotted as a function of the logarithmic concentration of plasminogen activator. We assayed both tissue-type and urokinase-type plasminogen activator activity. The intraassay CV was &lt; 4.7% (n = 20); the interassay CV was &lt; 3.1% (n = 15). Using the optimized procedure, we modified the assay for determination of plasma-coagulum lysis time in human plasma. We established a reference interval for lysis time in apparently healthy subjects of 75 to 201 ks. Patients with deep vein thrombosis showed significantly (P = 0.013) higher values.
Rapid, fully automated measurement of plasma homocyst(e)ine with the Abbott IMx analyzer
Authors: Shipchandler M T , Moore E G 
Published: January 2020

Abstract
We have developed a totally automated fluorescence polarization immunoassay for homocyst(e)ine with no pretreatment or chromatographic steps. Comparison with four well-established chromatographic methods yielded r values ranging from 0.980 to 0.997 and slopes from 1.030 to 1.493. Inter- and intraassay CVs ranged from 0.0% to 8.0% and from 0.0% to 6.4%, respectively. Imprecision (CV) of measuring six plasma samples on three instruments ranged from 6.3% to 10.2%. The assay was linear for plasma samples diluted with buffer from 0 to 8-fold. Mean recovery of homocysteine added to two plasma samples was 97.1% and 99.9%. The assay exhibited almost no cross-reactivity towards cysteine and methionine, and a batch of 20 samples can be processed in 60 min.
Apolipoprotein E: an important gene and protein to follow in laboratory medicine
Authors: Siest G , Pillot T , Régis-Bailly A , Leininger-Muller B , Steinmetz J , Galteau M M , Visvikis S 
Published: January 2020

Abstract
The human apolipoprotein (apo) E gene is polymorphic, with three common alleles (epsilon 2, epsilon 3, epsilon 4) coding for three isoforms (E2, E3, E4). The isoforms differ from each other by a single amino acid substitution, and also differ in their binding affinity for the four apo E receptors. Apo E polymorphism is an important determinant of risk for the development of cardiovascular and Alzheimer diseases, the prevalence of the epsilon 4 allele being increased in both kinds of patients compared with control subjects. Furthermore, the prevalence of the epsilon 4 allele differs among populations (range 5-40%, respectively, for Taiwanese and Papua New Guineans). Genotyping or phenotyping needs to be introduced in clinical laboratories. The choice of the method should be based on the types of patients who are examined. The apo E genotype is also a determinant of apo E plasma concentration. Standardization of apo E measurement is an important prerequisite before investigating the clinical interest of plasma apo E concentration. Determination of apo E genotype/phenotype and later the plasma concentration are expected to yield useful clinical laboratory information.
Increased urinary excretion of analogs of Krebs cycle metabolites and arabinose in two brothers with autistic features
Authors: Shaw W , Kassen E , Chaves E 
Published: January 2020

Abstract
A marked increase in analogs of Krebs cycle metabolites was found in the urine of two brothers with autistic features. These metabolites included citramalic, tartaric (3-OH-malic), and 3-oxoglutaric acids and compounds tentatively identified as a citric acid analog and partially identified as a phenylcarboxylic acid by the fragmentation pattern of the trimethylsilyl (TMS) derivatives of the compounds and mass shifts of the same compounds derivatized with perdeuterated N,O-bis(trimethylsilyl)trifluoroacetamide. The molecular mass of the TMS derivative of the tentatively identified citric acid analog was 596 Da, based on a finding of a significant M - 15 ion at m/z 581. The citric acid analog was excreted in quantities as high as 137 mmol/mol creatinine, based on the response factor of citric acid as a surrogate calibrator. A carbohydrate with a retention time and mass spectrum identical to arabinose was also found in high concentrations in the urine of these brothers.
Inborn errors of metabolism diagnosed in sudden death cases by acylcarnitine analysis of postmortem bile
Authors: Rashed M S , Ozand P T , Bennett M J , Barnard J J , Govindaraju D R , Rinaldo P 
Published: January 2020

Abstract
Fatty acid oxidation (FAO) disorders represent a frequently misdiagnosed group of inborn errors of metabolism. Some patients die at the first episode of fasting intolerance and, if appropriate investigations are not undertaken, often meet the criteria of sudden infant death syndrome (SIDS). To expand existing protocols for the postmortem diagnosis of FAO and other metabolic disorders, we tested the hypothesis that analysis for acylcarnitine in bile, a specimen readily available at autopsy, may be utilized for diagnostic purposes. Using electrospray/tandem mass spectrometry, we analyzed for acylcarnitine postmortem bile specimens from two infants with long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency, one infant with glutaryl-CoA dehydrogenase deficiency, and 17 uninformative SIDS cases as controls. The affected cases, and none of the controls, showed marked accumulation of C10-C18 acylcarnitines or glutarylcarnitine (acyl/free carnitine ratio: 5.2, 2.7, and 1.9, respectively; controls 0.2 +/- 0.1). In one patient, all other diagnostic methods were uninformative, suggesting that bile acylcarnitine profiling could lead to identification of previously overlooked cases.