bluuebunny/crossref_metadata_2025_split huggingface dataset:
Computer-aided infrared analysis of urinary calculi.
Authors: Berthelot M , Cornu G , Daudon M , Helbert M , Laurence C 
Published: January 2020

Abstract
We have created a library of 497 digitized infrared spectra of 58 components of urinary calculi and of their usual binary and ternary mixtures. We tested the operation of the "Birsy" search program (Bruker Analytische Messtechnik) with this library for the interpretation of infrared spectra of 50 urinary calculi, selected from both classical and difficult cases. This program correctly identifies the two first components 98% of the time and the third (minor) component 70% of the time. Using this program, those without training or experience in infrared analysis can routinely use the infrared method of analysis of urinary calculi.
Four methods compared for measuring des-carboxy-prothrombin (PIVKA-II).
Authors: Widdershoven J , van Munster P , De Abreu R , Bosman H , van Lith T , van der Putten-van Meyel M , Motohara K , Matsuda I 
Published: January 2020

Abstract
PIVKA-II (Protein Induced by Vitamin K Absence) is abnormal des-carboxylated prothrombin, which is present in vitamin K deficiency or in patients using warfarin. With a sensitive method for PIVKA-II, biochemical vitamin K deficiency can be established before clinical symptoms occur. We give an overview of methods used to detect PIVKA-II, and four selected methods are inter-compared: (a) measuring total factor II including PIVKA-II by using Echis carinatus snake venom as an activator of prothrombin; (b) measuring PIVKA-II by using snake venom as an activator of factor II after adsorption of functional factor II onto barium sulfate; (c) electrophoresis-immunofixation method; and (d) enzyme immunoassay. We found d to be the most sensitive and reliable method for PIVKA-II.
Antimony accumulation in hair during treatment of leishmaniasis.
Authors: Dorea J G , Costa J M , Holzbecher J , Ryan D E , Marsden P D 
Published: January 2020

Abstract
We used instrumental neutron activation analysis (INAA) to determine antimony in small quantities of hair from individuals living in an area of endemic leishmaniasis. The groups studied were 12 patients undergoing treatment with N-methylglucamine antimoniate, 34 patients who had received such treatment a year ago, and 17 control subjects (untreated) who were living in the same area. Patients receiving treatment showed mean and median (12.13, 2.9 micrograms/g) values for antimony in hair that significantly exceeded those in either controls (1.01, 0.4 microgram/g) or patients one year after treatment (1.54, 1.0 microgram/g). We conclude that INAA can be useful in monitoring and differentiating such exposure to antimony in patients under treatment.
An alternative explanation for the changes in erythrocyte fatty acids observed in diabetes mellitus.
Authors: Taylor A J , Jennings P E , Barnett A H , Pandov H I , Lawson N 
Published: January 2020

Abstract
Fatty acids in erythrocyte membranes and plasma were determined by capillary gas-liquid chromatography in 27 controls and 44 subjects with insulin-dependent diabetes mellitus. Significant decreases in stearic acid (P less than 0.00003) and arachidonic acid (P less than 0.001) and significant increases in palmitic acid (P less than 0.00003) were observed in erythrocytes from diabetic patients. The stearic:oleic acid ratios and arachidonic:linoleic acid ratios in erythrocytes were significantly lower in diabetic patients than in controls (P less than 0.0003 and less than 0.0007, respectively). The relative concentration of palmitic acid in plasma (as a percentage of the sum of the five major fatty acids) was increased in diabetic patients, as compared with controls (P less than 0.0125). We observed no other significant differences in fatty acids in plasma, making it unlikely that changes in fatty acids in erythrocyte membranes in diabetic patients can be accounted for simply by alterations in the fatty acids in plasma. We propose that impaired metabolic control associated with diabetes mellitus may interfere with the maintenance of fatty acid profiles in erythrocyte membranes against the concentration gradients in plasma.
Chemiluminescence immunoassay of thyrotropin with acridinium-ester-labeled antibody evaluated and compared with two other immunoassays.
Authors: Bounaud M P , Bounaud J Y , Bouin-Pineau M H , Orget L , Begon F 
Published: January 2020

Abstract
A new chemiluminometric immunoassay of thyrotropin (TSH) involves antibody labeled with acridinium ester ("Magic Lite System," Ciba Corning Diagnostic Corp.). The assay is rapid, with two incubations totaling 2.5 h, requires two standards per run, and takes 10 s per sample for the quantification step. Analytical performance, within- and between-run reproducibilities, and linearity were excellent. The detection limit is 0.04 milli-int. unit/L. Results correlated well with those obtained by immunoradiometric assay (RIA-gnost hTSH, Hoechst-Behring) and immunofluorometric assay (hTSH Delfia, LKB): r = 0.975. TSH measurements in 32 euthyroid subjects ranged from 0.4 to 4.8 milli-int. units/L (mean 1.35 milli-int. units/L). TSH values for 51 hypothyroid and subclinically hypothyroid patients ranged from 2 to 65 milli-int. units/L. TSH values for 33 hyperthyroid patients (less than 0.14 milli-int. unit/L, less than 0.04 milli-int. unit/L in 16 of the 33) were clearly lower than for most untreated euthyroid subjects. For 169 other individuals whose thyroid function was being routinely assessed. TSH ranged from 0.4 to 4.8 milli-int. units/L, three had TSH less than 0.14 milli-int. unit/L, and four had TSH between 0.14 and 0.4 milli-int. unit/L. This system is as efficient and reliable for screening for thyroid function as the two comparison systems.
Fructosamine: structure, analysis, and clinical usefulness.
Authors: Armbruster D A 
Published: January 2020

Abstract
Glucose molecules are joined to protein molecules to form stable ketoamines, or fructosamines, through glycation, a nonenzymatic mechanism involving a labile Schiff base intermediate and the Amadori rearrangement. The amount of fructosamine in serum is increased in diabetes mellitus owing to the abnormally high concentration of sugar in blood. The concentration of fructosamine in serum thus reflects the degree of glycemic control attained by the diabetic patient and is useful in monitoring the effectiveness of therapy in diabetes over a period of several weeks, in a manner analogous to the determination of glycated hemoglobin. Of the analytical approaches used to measure fructosamine, affinity chromatography with m-aminophenylboronic acid and the nitroblue tetrazolium reduction method appear to be the most practical means for clinical chemists to assay fructosamine quickly, economically, and accurately. Fructosamine values can readily distinguish normal individuals and diabetic patients in good glycemic control from diabetics in poor control. Unlike glycated hemoglobin, which reflects the average blood sugar concentration over the past six to eight weeks, fructosamine reflects the average blood sugar concentration over the past two to three weeks. Thus a clinical advantage is that fructosamine responds more quickly to changes in therapy, thereby allowing for improved glycemic control. Used in conjunction with determinations of blood sugar and (or) of glycated hemoglobin, or by itself, the fructosamine assay can provide clinically useful information for the detection and control of diabetes.
An enzymic assay for the specific determination of methanol in serum.
Authors: Vinet B 
Published: January 2020

Abstract
This method for the specific determination of methanol in serum is based on the following two reactions: (formula; see text) Alcohol oxidase is not specific: it converts all lower alcohols to their corresponding aldehydes; however, formaldehyde dehydrogenase is specific and thus the transformation of NAD+ to NADH (which is used to monitor the reaction) proceeds only if methanol is originally present in the sample. The method was automated with a Roche COBAS FARA centrifugal analyzer. The calibration curve is linear between 0.6 and 12 mmol/L. The detection limit is about 0.6 mmol/L. The CV is 4.6% for a concentration of 3 mmol/L. When 55 serum specimens known to be free of methanol were supplemented with known amounts of methanol and analyzed by the enzymatic method, the results correlated well (r = 0.987) with the true values, the regression equation being: y = 1.016x + 0.661, where x represents the true values. Results are not affected by other alcohols that may be present in serum, by methanol metabolites, or by some commonly prescribed drugs. The major advantage of this new assay is that it can be used 24 h a day in any clinical chemistry laboratory.
31P nuclear magnetic resonance study of variations in intra-erythrocytic ATP concentration and pH induced by surgical trauma.
Authors: Monti J P , Martinez S , Braguer D , Courtina C , François G , Crevat A 
Published: January 2020

Abstract
Variations in intracellular pH and ATP concentrations in erythrocytes were studied in patients undergoing a mild surgical intervention. Intra-erythrocytic pH was decreased at the end of the operation; ATP concentrations concomitantly increased, but not highly significantly. These variables returned to their initial values by 20 h after the end of surgery.
Chemical factors important to calcium nephrolithiasis: evidence for impaired hydroxycarboxylic acid absorption causing hyperoxaluria.
Authors: Cowley D M , McWhinney B C , Brown J M , Chalmers A H 
Published: January 2020

Abstract
An investigation of variables important to calcium stone formation in urine indicated significantly increased daily excretion of calcium and oxalate and decreased excretion of ascorbate and citrate by recurrent calcium stone formers. In addition, urine volume, sodium, mucopolysaccharide, and protein were also significantly increased. We compared the uptake of citrate and ascorbate from the gut into the blood in normal controls and stone formers. These studies indicated significantly depressed absorption of both these hydroxycarboxylic acids in recurrent calcium stone formers. We also found that concurrent administration of citrate inhibited ascorbate absorption and increased urinary oxalate excretion after an ascorbate load in normal subjects and stone formers. These findings suggest a mechanism that explains hyperoxaluria in stone patients on the basis of a malabsorption of citrate, ascorbate, and possibly other hydroxycarboxylic acids.
Improved separation of fetal hemoglobin by mini-column chromatography.
Authors: Morin L G , Barton E G 
Published: January 2020

Abstract
We present chromatographic conditions for separating and measuring fetal hemoglobin on a 5-cm column of Sephadex CM-50. A distinct fetal band is evident, even when present at less than 1% of total hemoglobin. Precision (CV) of better than 5% is achievable.
Value and limitations of a highly sensitive immunoradiometric assay for thyrotropin in the study of thyrotroph function.
Authors: Caldwell G , Gow S M , Sweeting V M , Beckett G J , Seth J , Toft A D 
Published: January 2020

Abstract
Using a highly sensitive and specific immunoradiometric assay for thyrotropin, we studied thyrotroph function in 232 new patients referred to a thyroid clinic and in 13 patients after treatment for hyperthyroidism. Significant thyrotroph responsiveness to thyroliberin (thyrotropin-releasing hormone, TRH) was found in all patients with values for basal thyrotropin greater than 0.1 milli-int unit/L. In no overtly hyperthyroid patient was any increment in thyrotropin recorded at 20 min after thyroliberin administration. In seven patients, four subclinically hyperthyroid and three who had received treatment, increments in thyrotropin from undetectable basal values were recorded, consistent with incomplete thyrotroph suppression. By use of assays with even higher sensitivity, one may be able to distinguish these patients from overtly hyperthyroid patients.
Transient hyperphosphatasemia of infancy and early childhood: clinical and biochemical features of 21 cases and literature review.
Authors: Stein P , Rosalki S B , Foo A Y , Hjelm M 
Published: January 2020

Abstract
Clinical and biochemical features of transient hyperphosphatasemia of infancy and early childhood are reviewed in 21 patients we have studied and in a further 93 cases reported in the literature. The diagnosis is suggested by the finding of an increased activity of alkaline phosphatase (EC 3.1.3.1) in plasma, typically more than fivefold the adult upper reference limit, in a child under five years of age, without evidence of liver or bone disease. The condition is confirmed by the presence of a characteristic pattern of alkaline phosphatase isoenzymes and by the normalization of the enzyme's activity in plasma within approximately three months. The etiology of the condition and possible mechanisms of the enzyme increase are discussed.
Early diagnosis of acute myocardial infarction by rapid analysis of creatine kinase isoenzyme-3 (CK-MM) sub-types.
Authors: Wu A H , Gornet T G , Wu V H , Brockie R E , Nishikawa A 
Published: January 2020

Abstract
We compared the clinical sensitivity, specificity, and diagnostic efficiency of measuring creatine kinase-3 (MM) isoenzyme sub-types (CK, EC 2.7.3.2) with the measurement of CK-2 (MB) isoenzymes for the diagnosis of acute myocardial infarction. Serial blood collections at 3-h intervals from 35 patients with acute myocardial infarction were examined. In attempts to reperfuse their coronary arteries, some of these patients were treated with pharmacological thrombolysis (streptokinase, tissue plasminogen activator), with or without coronary angioplasty. The infarction patients were divided into two groups: patients who were successfully treated with thrombolytic agents (i.e., they achieved coronary reperfusion), and patients who were treated unsuccessfully or who were not treated acutely. We also examined blood from 34 non-infarction patients. We measured CK-3 sub-types by both anion-exchange liquid chromatography and a modified high-voltage electrophoresis method, and CK-2 by immunoprecipitation. Our results show that during the first few critical 3 to 9 h after onset of chest pain, measurement of CK-3 sub-types has the highest diagnostic efficiency; in contrast, CK-2 has the highest efficiency during the 10- to 21-h time intervals. Thus early diagnosis of acute myocardial infarction can be based on rapid assays of CK-3 sub-types.
Two-stage transformation systems for normalization of reference distributions evaluated.
Authors: Linnet K 
Published: January 2020

Abstract
In two-stage transformation systems for normalization of reference distributions, the asymmetry is first corrected, and any deviation of kurtosis is then adjusted. The simulation studies reported here show that these systems have previously been assessed too optimistically because the sample variation of the transformation parameters was neglected. Applying a goodness-of-fit test to transformed values shows that one should accept gaussianity only for p-values greater than 0.15 instead of those greater than 0.05. Further, the calculated 90% confidence intervals of reference limits should be expanded by 25%. When the correct level of significance is used, only real reference distributions that deviate moderately from the gaussian form are normalized. Calculation of confidence intervals demonstrated that 50 to 450 subjects are needed for a precise parametric estimation of the 95% reference interval. For the nonparametric approach, 125 to 700 reference subjects are necessary. The larger sample sizes are needed when distributions show pronounced skewness.
Cholesteryl ester transfer activity in plasma measured by using solid-phase-bound high-density lipoprotein.
Authors: Sparks D L , Frohlich J , Cullis P , Pritchard P H 
Published: January 2020

Abstract
We studied the ability of lipid-transfer factors in plasma to promote transfer, to endogenous lipoproteins, of [3H]cholesteryl ester from high-density lipoprotein (HDL) covalently bound to Sepharose 4B beads. After incubation for 2 h at 37 degrees C, 12 to 14% of the [3H]cholesteryl ester had been transferred to the lipoproteins of the plasma, in the proportions 57% to HDL and 43% to low- and very-low-density lipoproteins. This process was a function of the amount of plasma present and was stimulated by addition of partly purified lipid-transfer protein. Transfer also depended on the concentration of donor HDL but was independent of the amount of acceptor lipoprotein. This simple evaluation of cholesteryl ester transfer does not require removal of lipoproteins from the plasma before incubation.
Percentile estimates of reference values for total protein and albumin in sera of premature infants (less than 37 weeks of gestation).
Authors: Zlotkin S H , Casselman C W 
Published: January 2020

Abstract
We measured the concentrations of total protein and albumin in sera of 281 well-fed premature infants, gestational ages 22-36 weeks, and calculated reference values from the 10th to 90th percentiles. The mean serum albumin concentration (27.6 +/- 4.4 g/L, mean +/- SD) and total protein concentration (49.2 +/- 6.7 g/L) at a postnatal age of 14.5 days were lower than reference values for full-term infants. We detected a significant positive correlation between albumin concentration and gestational age (r = 0.34, p less than 0.01) and total protein concentration and gestational age (r = 0.43, p less than 0.01). Even though albumin values were low, generalized edema was not present. We conclude that values for total protein and albumin in the preterm infant are lower than in the full-term infant but are an expected physiological response to premature birth.
Distribution of cyclosporine in blood of a renal-transplant recipient with type V hyperlipoproteinemia.
Authors: Verrill H L , Girgis R E , Easterling R E , Malhi B S , Mueller W F 
Published: January 2020

Abstract
A patient with severe type V hyperlipoproteinemia and chronic end-stage renal disease received a renal transplant and therapy with cyclosporine. Concentrations of the drug in plasma as determined by liquid chromatography appeared extraordinarily high for the dose ingested. When we measured the drug in the plasma, plasma cleared by ultracentrifugation, leukocytes, erythrocytes, and whole blood, we found that the high concentrations of cyclosporine were associated with the chylomicrons that always were present in this patient's blood. Cyclosporine added directly to this patient's plasma was less associated with the plasma lipids. Isolated lymphocytes and kidney slices incubated with plasma from this patient bound no more drug than when incubated with nonhyperlipemic plasma containing cyclosporine at a normal therapeutic concentration. We conclude that the cyclosporine associated with the chylomicrons in this patient was not biologically available to either lymphocytes or kidney tissue. We strongly recommend the use of chylomicron-cleared plasma for therapeutic drug monitoring of cyclosporine in type V hyperlipoproteinemic patients.
Quinine directly determined in serum or urine by separation fluoroimmunoassay.
Authors: Sidki A M , Al-Abdulla I H , Rowell F J 
Published: January 2020

Abstract
We developed and validated a magnetizable solid-phase fluoroimmunoassay for directly determining quinine in serum or urine. We prepared the immunogen by coupling quinine hemisuccinate to keyhole-limpet hemocyanine, using this to immunize three sheep, and coupling the antisera to magnetizable solid-phase particles to facilitate separation of bound antigen from interfering components of serum or urine. We tested the stability of two fluorescein-labeled derivatives of quinine--one prepared by direct conjugation of quinine to dichlorotriazenyl aminofluorescein, the other by conjugating quinine hemisuccinate to fluorescein thiocarbamyl ethylenediamine. The latter was unstable. Using the former label and an 30-min incubation, we saw no interference by quinidine (an enantiomer of quinine) or other antimalarial drugs at their therapeutic concentrations.
Fast kinetic method for methemoglobin developed and adapted for quantification of hemoglobin in whole blood.
Authors: Cummings R H , Pardue H L 
Published: January 2020

Abstract
We studied the kinetics of the reaction of cyanide with methemoglobin (mHb), used the information to develop a fast kinetic method for quantifying methemoglobin, then used that method to quantify hemoglobin (Hb) in whole blood based on the reaction with ferricyanide to produce mHb. Reaction conditions for mHb and cyanide are adjusted to give pseudo-first-order behavior with an apparent rate constant that increases linearly with cyanide concentration, decreases linearly with pH, and follows an Arrhenius-type relationship with temperature. Absorbance change, computed from kinetic data with a curve-fitting method, varies linearly with mHb concentration. Although the reactions are monitored most reliably with stopped-flow mixing, cyanide concentration was used to decrease reaction velocities to be compatible with centrifugal mixing. Kinetic results (y) for Hb in blood by both mixing methods correlate well with equilibrium results (x): y = 1.000x + 0.02 mmol/L, Syx = 0.06 mmol/L with stopped-flow mixing; y = 1.03x + 0.12 mmol/L, Syx = 0.07 mmol/L with centrifugal mixing; r = 0.96 and n = 21 in each case.
Estimating fat in feces by near-infrared reflectance spectroscopy.
Authors: Koumantakis G , Radcliff F J 
Published: January 2020

Abstract
We describe use of near-infrared reflectance spectroscopy (NIRRS) to estimate the amount of fat in feces, for diagnosis of steatorrhea. After sample homogenization, the spectrum of the fecal homogenate is scanned over the near-infrared region. Assay of 94 samples of feces having a known concentration of fat showed the appropriate wavelengths for the NIRRS procedure to be 1734, 1778, 1818, 2270, and 2310 nm. The reflectance output of 47 fecal samples subsequently measured at these wavelengths was used to compute the reflectance scaling factors (F values) by the instrument's microprocessor. Assay of fat content in a further 124 fecal samples, by both hydrolysis/titration (J Biol Chem 1949;177:347) and the NIRRS procedure at the wavelengths and corresponding F values previously determined, gave results that correlated highly satisfactorily. However, the NIRRS procedure demonstrated much better precision.
Detecting errors in blood-gas measurement by analysis with two instruments.
Authors: Metzger L F , Stauffer W B , Krupinski A V , Millman R P , Cembrowski G S , Pack A I 
Published: January 2020

Abstract
We performed a two-stage prospective evaluation of the error detection capabilities of duplicate analysis of blood-gas specimens. In the first stage we analyzed 1601 specimens with a Corning Model 175 blood-gas analyzer as the test instrument and a Corning Model 178 analyzer as the reference instrument, and in the second stage we analyzed 1544 specimens with two Model 178 analyzers. In each stage the designated reference instrument underwent troubleshooting whenever an analytical error was detected; the test instrument underwent troubleshooting only when error conditions were indicated by means other than duplicate analysis. An error was considered to have occurred if the difference between the duplicate analyses exceeded 0.02 (for pH), 0.53 kPa, i.e., 4 mmHg (pCO2), or 7% (pO2). The number of specimens for which errors were detected was 97 (6.1%) in the first stage, 23 (1.5%) in the second. For each analyte more errors were detected with the Model 175 analyzer (of older design) than with the newer Model 178 analyzer. Furthermore, in certain periods associated with the use of particular electrodes there were very high error rates for individual analytes: 8% for pCO2, 18% for pO2. We conclude that duplicate analysis should be considered as a possible required standard for error detection.