bluuebunny/crossref_metadata_2025_split huggingface dataset:
The multilayered film analyzer: glucose in serum, plasma, cerebrospinal fluid, and urine; and urea nitrogen in serum and plasma.
Authors: Warren K , Kubasik N P , Brody B B , Sine H E , D'Souza J P 
Published: February 2020

Abstract
Some basic laboratory performance criteria were studied for the Eastman Kodak glucose and urea nitrogen analyzer. Serum, plasma, urine, and cerebrospinal fluid were tested. Precision, both "within-day" and "between-day," for both analytes was less than 2.2% (CV). Both analytes demonstrated linearity, with about 100% recovery of added substrates. Comparisons with continuous-flow procedures demonstrated good correlation. A variety of sera and plasmas can be used for glucose analysis; oxalate--fluoride-treated plasma is unacceptable for use in analysis for urea nitrogen. We saw no effects on glucose or urea nitrogen analysis from hemolysis, lipemia, icterus, some common drugs, ammonia, or abnormally high protein concentrations. Minimum amounts detectable were: glucose (serum) 104 mg/L; glucose (cerebrospinal fluid) 100 mg/L; and urea nitrogen (serum) 21 mg/L. Calibration procedures are discussed for protein-based and aqueous samples.
Parallel evaluation of Astra 8 and Astra 4 multichannel analyzers in two hospital laboratories.
Authors: Truchaud A , Hersant J , Glikmanas G , Fievet P , Dubois O 
Published: February 2020

Abstract
We evaluated the new Beckman multichannel analyzers Astra 8 and Astra 4. Both instruments performed the following tests: Na, K, Cl, CO2, urea, glucose, and creatinine in plasma and Na, K, Cl, and creatinine determinations in urine. We tested precision, accuracy, and linearity at the usual concentrations in plasma and urine. We compared the Astra 8 and Astra 4 with continuous-flow (SMA 6) and discrete analyzers such as IL 243, Beckman KLiNa Flame, Beckman System 1, Corning 920 M Chloride Meter, and the Corning Blood-Gas Analyzer 175. Special tests were performed on plasma-to-plasma and urine-to-plasma carryover. Both analyzers are easy to operate and suitable for both emergency and routine use.
Drug-induced dyslipoproteinemia: a report of two cases.
Authors: Naito H K , McHenry M C , Lewis L A 
Published: February 2020

Abstract
We describe two cases of atypical dyslipoproteinemia due to drug-induction. This secondary form of lipoprotein abnormality is unique because the newly available drug, miconazole, apparently directly delipidated the alpha-lipoproteins in the bloodstream. On closer study we found that the delipidation was caused by the vehicle rather than the fungicide--more specifically, only by the polyethoxylated castor oil in the vehicle. It affects serum lipoproteins both in vitro and in vivo, and the effect is species-specific. In vitro studies indicate that it preferentially delipidates high-density lipoprotein rather than low-density lipoprotein. Because its effects on the serum lipoproteins of rats resemble those on man, and because aortic lesions were produced in rats injected daily (90 mL/L) with this substance, caution is indicated in long-term use of drugs containing this chemical component in the vehicle.
Mechanism of interference by hemoglobin in the determination of total bilirubin. I. Method of Malloy-Evelyn.
Authors: Shull B C , Lees H , Li P K 
Published: February 2020

Abstract
Oxyhemoglobin is the species of hemoglobin in erythrocyte hemolysates that inhibits the diazo reaction. Ferric hemoglobin derivatives and species with relatively low molecular mass do not interfere. Conversion of oxyhemoglobin to acid hematin under assay reaction conditions is associated with rapid destruction of bilirubin, which accounts for the diazo reaction error. The most probable mechanism for this destruction of bilirubin is an oxidative reaction involving H2O2, formed in the oxidation of hemoglobin, and acid hematin acting as a pseudoperoxidase. We could find no evidence for other mechanisms of interference such as spectral error or azobilirubin destruction. Addition of potassium iodide, 4.0 mmol/L final concentration in the reaction mixture, eliminates interference from hemoglobin added to give concentrations as great as 10 g/L. It also eliminated the effects of hemolysis in the method of Ertingshausen et al. (Clin. Chem. 19: 1366, 1973), in which ethylene glycol is used as the accelerator.
Screening radioimmunoassay for aldosterone in preheated plasma without extraction and chromatography.
Authors: Connolly T M , Tibor L , Gless K H , Vecsei P 
Published: February 2020

Abstract
We directly estimated plasma aldosterone radioimmunologically with use of an antiserum raised against an aldosterone-3-oxime/bovine serum albumin conjugate, the estimation being on samples with and without heating (60 degrees C), and diluted and undiluted. Values so obtained were compared with those by radioimmunoassay after extraction and chromatography. The correlation--even negative values were obtained--was poorest when the steroid was directly estimated in nonheated, undiluted plasma. Correlations were best (r = 0.918) for preheated and diluted native plasma, and the interassay CV was 9.8% (n = 57). However, there were some extraordinarily high values. After equilibrium dialysis of native and preheated (60 degrees C) plasma (15 plasma samples), the percentages of apparent free aldosterone and cortisol increased from 51.4 +/- 2.6% (SEM) to 64.3 +/- 1.6% and from 11.5 +/- 2.2% to 61.1 +/- 1%, respectively. We conclude that aldosterone-binding proteins play a role in direct radioimmunoassays of aldosterone in plasma, but by heating (with or without diluting) the plasma, direct assay can be used as a simple, fast, and inexpensive screening method.
Metastable creatine kinase MM and complexes of creatine kinase BB and immunoglobulin G, "atypical" isoenzymes with similar electrophoretic mobility.
Authors: Homburger H A , Wold L , Jacob G L , O'Brien J 
Published: February 2020

Abstract
Metastable creatine kinase MM isoenzyme was isolated and partially purified from homogenates of myocardium and skeletal muscle by gradient elution on carboxymethyl cellulose. This variant isoenzyme migrated between the MM and MB isoenzymes on agarose electrophoresis, accounted for 3.5% of the total creatine kinase activity in each tissue, was not a macromolecule, and had stable electrophoretic mobility only in borate buffer (0.02 mol/L). By comparison, the creatine kinase isoenzymes with similar "atypical" electrophoretic mobility in serum specimens were complexes of the BB isoenzyme and immunoglobulin G. These complexes were measured by a radioimmunoassay specific for the creatine kinase B-subunit and eluted predominantly with the MB isoenzyme in a commercial anion-exchange reagent system.
Liquid-chromatographic determination of norepinephrine and epinephrine in human plasma.
Authors: Yui Y , Fujita T , Yamamoto T , Itokawa Y , Kawai C 
Published: February 2020

Abstract
We describe a “high-performance” liquid-chromatographic method for measuring picogram amounts of norepinephrine and epinephrine simultaneously in human plasma. Alumina-treated samples are injected onto a strong cation-exchange column (Zipax SCX) for the separation of catecholamines, with a sodium phosphate buffer/acetonitrile mixture as mobile phase. The separated catecholamines then enter a continuous-flow system and the reagents for the trihydroxyindole reaction are added sequentially; the fluorescent products are then measured with a spectrofluorophotometer. Analytical recoveries from plasma averaged 66% for norepinephrine, 68% for epinephrine. Amount and response (peak height) were linearly related up to 1000 pg. For catecholamines in human plasma, within-run and day-to-day CV's were 0.2% and 1.0%, respectively, for norepinephrine, and 0.3% and 0.9%, respectively, for epinephrine. Average values for norepinephrine and epinephrine in apparently normal human plasma were 185 +/- 29 ng/L and 32 +/- 8 ng/L, respectively (mean +/- SEM, n = 10). This relatively rapid and highly sensitive system is suitable for routine use.
Simultaneous liquid-chromatographic determination of three antiarrhythmic drugs: disopyramide, lidocaine, and quinidine.
Authors: Flood J G , Bowers G N , McComb R B 
Published: February 2020

Abstract
We report a common methodology for determining three antiarrhythmic drugs: disopyramide, lidocaine, and quinidine. Alkalinized serum and internal standard (p-chlorodisopyramide) are extracted into dichloromethane, the organic phase is evaporated, and the redissolved residue is injected onto a reversed-phase column (micron Bondapack C18). Quantitation is via peak-height ratios of analyte vs internal standard (as detected at 205 nm) referenced to a serum-based multiple-drug standard. A mobile phase of 30 mmol/L phosphate buffer and acetonitrile (72/28 by vol) is used. These conditions yiel; optimum separation and band symmetry for the analytes and some of their metabolites. Crucial factors in this simultaneous assay include pH of the mobile phase and injected solution, extraction time, and evaporation technique. Day-to-day precision (CV) for all drugs was less than 5%, and correlation with other assay techniques for each drug is reported. The method enables more efficient use of personnel and instrumentation without sacrificing analytical quality.
Use of 3,5-dichloro-2-hydroxybenzenesulfonic acid/4-aminophenazone chromogenic system in direct enzymic assay of uric acid in serum and urine.
Authors: Fossati P , Prencipe L , Berti G 
Published: February 2020

Abstract
A new direct colorimetric procedure for uric acid assay in serum or urine is described, utilizing a 3,5-dichloro-2-hydroxybenzene sulfonic acid/4-aminophenazone chromogenic system in the presence of horseradish peroxidase and uricase from Aspergillus flavus. This chromogen system has a high absorptivity, affording useful results with sample/reagent volume ratios as low as 0.025. The procedure is applicable to serum, plasma, or diluted urine. A single working reagent is used; the reaction is complete in less than 15 min at room temperature. The red dye formed is measured at 520 nm; a blank sample measurement is not needed. The standard curve for the method is linear for uric acid concentrations up to 1500 mumol/L. Average analytical recovery of uric acid in human sera and urine exceeded 99%; within-run and between-run precision studies showed CV's of less than or equal to 1.2 and less than or equal to 2.2%, respectively. The new procedure correlated well with the uricase/catalase and uricase/ultraviolet methods. The method is suitable for automation.
Specific lymphocyte phospholipid changes in chronic renal failure.
Authors: Kalofoutis A 
Published: February 2020

Abstract
I describe phospholipid fluctuations in lymphocytes of peripheral blood of patients with chronic renal failure who were undergoing maintenance hemodialysis. The findings of decreased concentration of total phospholipids, phosphatidylcholine, and phosphatidylethanolamine, and increased concentrations of phosphatidylinositol and diphosphatidylglycerol are discussed, in relation to the lymphocyte membrane enzymic systems, and immune response.
Binding of enzyme--IgG complexes in human serum to Protein-A Sepharose CL-4B.
Authors: Bauer K , Bayer P M , Deutsch E , Gabl F 
Published: February 2020

Abstract
We describe a simple method for detecting enzyme--immunoglobulin G (IgG) complexes in human serum. Protein-A Sepharose CL-4B binds IgG and therefore also the enzyme--IgG complexes, which can then be separated easily from the serum by centrifugation. We demonstrate this separation in two patients, one with a complex of IgG and creatine kinase (EC 2.7.3.2) BB isoenzyme, the other with an IgG--alkaline phosphatase (EC 3.1.3.1) complex. Both patients had unexplainably high activities of the respective enzymes in their serum. The method we propose should be a useful, simple, routine method of detection in cases where IgG--enzyme complexes are suspected.
Digitalis glycosides in serum, urine, and cerebrospinal fluid, determined with a commercial radioimmunoassay.
Authors: Nore A K , Storstein L , Larsen A , Amlie J P 
Published: February 2020

Abstract
We evaluated a commercial (Clinical Assays, Inc.) 125I radioimmunoassay for digitoxin for use in measuring cardiac glycosides in serum, buffer, urine, and cerebrospinal-fluid samples. We also assessed interference of seven cardioactive metabolites of digitoxin, including digoxin, with the assay. The precision of the assay was adequate for all matrixes studied for glycoside concentrations less than 5 microgram/L. Reactivity in the assay was dependent on the nature of the matrix: buffer and serum samples containing digitoxin showed a stronger reactivity than did samples of urine and cerebrospinal fluid. Patients' samples must therefore be analyzed with a standard curve prepared by use of the same matrix. The digitoxosides of digitoxin showed a slightly higher reactivity in the assay than did digitoxin itself, but digitoxigenin showed a 50% lesser reactivity. Digoxin, its digitoxosides, and digoxigenin hardly react at all in the assay and so do not interfere with digitoxin determinations.
Enzymic inhibition assay for methotrexate with a discrete analyzer, the ABA-100.
Authors: Brown L F , Johnson G F , Witte D L , Feld R D 
Published: February 2020

Abstract
We adapted an inhibition assay for methotrexate, involving dihydrofolate reductase from bovine liver, for use with a discrete analyzer (the ABA-100). The analyzer was used both for dilution and a 5-min pre-incubation of the sample with NADPH--enzyme reagent, and for the assay itself. The standard curve was linear between 10 and 120 microgram/L. Without pre-incubation the standard curve was nonlinear. The presence of albumin in the NADPH--enzyme reagent enhanced both enzyme activity and stability. Within-run precision (CV) was 2.0% (n = 24), run-to-run precision 7.1% (n = 49). Results obtained on patients' samples (29 sera, 15 urines, 18 cerebrospinal fluids) by the present method and a radioimmunoassay method did not differ statistically (p greater than 0.05) when the paired data were analyzed by use of the sign test and Wilcoxon's ranked sign test.
Simplified radioimmunoassay of bradykinin in human plasma.
Authors: Verma P S , Lorenz P E , Sander G E 
Published: February 2020

Abstract
A greatly simplified radioimmunoassay for bradykinin in human plasma is described. Current techniques require multiple chromatographic steps or extraction procedures with analytical recoveries of bradykinin of often less than 60%. We present a method in which bradykinin is separated from components of higher relative molecular mass (including kininogens) in a single step, by use of a column of Sephadex G-25 medium (PD-10). The mean analytical recovery of tritiated bradykinin added to plasma is 85.5% (SD, 3.5%). The sensitivity of this radioimmunoassay is 25 pg per assay tube, equivalent to 125 ng per liter of plasma. Twenty to 30 blood samples may be completely processed and assayed within 6 h. As determined with this technique, concentrations of bradykinin in plasma from apparently normal subjects ranged from 2.5 to 5.2 microgram/L (mean 4.2, SD 1.1 microgram/L); these values are consistent with previously reported normal values.
Gas-chromatographic analysis for phencyclidine in plasma, with use of a nitrogen detector.
Authors: Bailey D N , Guba J J 
Published: February 2020

Abstract
We describe a reliable gas-chromatographic analysis for unchanged phencyclidine in human plasma, with use of a nitrogen detector. The assay is sufficiently sensitive to permit measurement of as little as 5 microgram of the drug per liter, in 2 mL of plasma. Phencyclidine is extracted from plasma at pH 10.5 into hexane/iso-amyl alcohol containing meperidine as the internal standard, back-extracted into dilute HCl, and re-extracted into hexane/iso-amyl alcohol after alkalinization of the HCl. The coefficients of variation for the analysis at respective concentrations of 100 and 200 microgram/L are: within-run 4.0% and 3.4%; between-run, 2.8% and 5.2%. This procedure, used in our laboratory for more than one year, has been applied to plasma from numerous individuals with nonfatal phencyclidine intoxication. Some representative examples are given.
Mannitol estimation in biological fluids by gas-liquid chromatography of trimethylsilyl derivatives.
Authors: Laker M F , Mount J N 
Published: February 2020

Abstract
We describe a procedure for estimating mannitol concentrations in biological fluids. Samples are mixed with internal standard solution (alpha-methylglucose), deproteinized if necessary, desalted, and dried. Specimens are then derivatized by adding pyridine/bis(trimethylsilyl)acetamide/trimethylchlorosilane and heating at 60 degrees C for 30 min. Samples are chromatographed on a 275-cm column of 10% OV-17, operated at 190 degrees C, and quantitated by peak-height measurement. The technique is linear, accurate, precise, sensitive, and free from interference. It has been used to measure mannitol in plasma, urine, and bile.
Thyroxine-binding globulin capacity and concentration evaluated from blood spots on filter-paper in a screening program for neonatal hypothyroidism.
Authors: Dussault J H , Morissette J , Letarte J , Guyda H , Laberge C 
Published: February 2020

Abstract
We describe a simple method for evaluating thyroxine-binding globulin capacity and concentration from a single 1-cm blood spot on filter-paper used in a screening program for neonatal hypothyroidism. This method permits prompt diagnosis of about 90% of the infants with thyroxine-binding globulin deficiency in our abnormal low-thyroxine, low-thyrotropin population. There was excellent equivalence between results obtained by our method and by the method of Chopra et al. (J. Clin. Endocrinol. Metab. 35:565, 1972), and minimal overlap between the population with low thyroxine-binding globulin and the low-thyroxine, normal thyrotropin population. We recommend this method to all programs in which a primary thyroxine measurement is used in screening for congenital hypothyroidism.
Nonspecific binding as a source of error in thyrotropin radioimmunoassay with polyethylene glycol as separating agent.
Authors: Chen I W , Heminger L , Maxon H R , Tsay J Y 
Published: February 2020

Abstract
We investigated the effects of nonspecific binding on thyrotropin values obtained by radioimmunoassay in which polyethylene glycol is used as precipitant. Differences in nonspecific binding among individual samples were significant (F-test, p less than 0.001, range 5.5 to 14.1%). Non-specific binding and total serum protein were directly correlated (r = 0.472, n = 59; p less than 0.001). Nonspecific binding increased with increasing concentrations of globulins but showed no relation to albumin concentration. If globulin concentration was less than 15 g/L, precipitation of the antigen—antibody complex by polyethylene glycol was incomplete. The mean value for thyrotropin in sera from 67 healthy subjects was 2.7 (SD 0.3) milli-international units per liter (milli-int. unit/L) without individual serum nonspecific binding correction, significantly (p less than 0.005) higher than that with nonspecific binding correction (1.6, SD 0.1, milli-int. unit/L). Evidently, inter-sample variations in nonspecific binding may cause significant errors under these conditions, which can be minimized by taking into account the individual nonspecific binding of each serum sample.
Enzymic color development of urinary 3 alpha-hydroxysteroids on thin-layer chromatograms.
Authors: Yamaguchi Y 
Published: February 2020

Abstract
I describe the use of 3 alpha-hydroxysteroid dehydrogenase (EC 1.1.1.50) for enzymic color development of 3 alpha-hydroxysteroids. Urinary 3 alpha-hydroxysteroids are converted to 3-ketosteroids by the enzyme, and the NADH formed is reacted with 2-p-iodophenyl-3-p-nitrophenyl-5-phenyl-tetrazolium chloride and "diaphorase" to form the colored formazan. The dye so formed on a thin layer chromatographic plate is measured by densitometoric scanning. I illustrate use of this method by showing results for urinary excretion of 3 alpha-hydroxysteroids by some various sorts of patients.
125I-labeled gonadoliberin and high specific activity and immunoreactivity: method of iodination and rapid separation.
Authors: Sarda A K , Barnes M A , Nair R M 
Published: February 2020

Abstract
We describe optimum conditions for iodinating gonadoliberin with use of relatively large proportions of Na 125I. Products of the iodination are separated on an anion-exchange resin (Amberlite IRA-400). The 125I-labeled gonadoliberin thus obtained has a high specific activity (1400 to 1590 Ci/g); because of the conditions of iodination, we believe that the predominant species of the labeled decapeptide is the mono-iodinated one. Our separation and purification of the labeled substance on ion-exchange resin is rapid, economical, and less cumbersome than the use of a Biogel P-2 column. There is no adsorption of the labeled hormone onto the resin, as evidenced by analytical recovery studies with tritium-labeled gonadoliberin. Paper-strip chromatoelectrophoresis showed no free Na 125I or radiolabeled damaged peptide fragments after purification on the resin. When antiserum was used at a concentration 32-fold that used in the regular assay procedure, only 4% of the radioactivity remained in the free form, indicating the high immunoreactivity of the labeled hormone.
Determination of urinary amino acids by liquid chromatography with “dabsyl chloride".
Authors: Lin J K , Wang C H 
Published: February 2020

Abstract
We describe a “high-performance” liquid-chromatographic procedure for measuring amino acids in 0.5 mL of urine. The procedure includes direct derivatization of amino acids in urine samples with “dabsyl chloride" (4-dimethylaminoazobenzene-4’-sulfonyl chloride). An aliquot of this dabsylated amino acid solution is analyzed on a muBondapak C18 column with ethanol/sodium acetate (20 mmol/L, pH 4.0) 4/6 (by vol.), as mobile phase. Dabsylated amino acids are detected by their absorbance at 425 nm and quantitated by measuring peak heights. The procedure allows for the reliable analysis of amino acids in urine at concentrations near 16 mg/L. The sensitivity of this analysis on column approaches 5 ng/sample. Higher urinary tryptophan concentrations were found in the urines of some cancer patients, whereas we saw no significant difference in urinary glycine between cancer patients and control subjects. The present method was shown to be a straightforward procedure for detecting phenylalanine in phenylketonuric urine. Extension of this procedure to screening for other inborn errors of aminoaciduria is recommended.
Amniotic fluid alkaline phosphatase, gamma-glutamyltransferase, and 5’-nucleotidase activity from 13 to 40 weeks’ gestation, and alkaline phosphatase as an index of fetal lung maturity.
Authors: Brocklehurst D , Wilde C E 
Published: February 2020

Abstract
Reference ranges for amniotic fluid alkaline phosphatase, gamma-glutamyltransferase, and 5-nucleotidase are described from 13 to 40 weeks’ gestation. Gamma-glutamyltransferase and 5-nucleotidase activities peak early in the second trimester and then decrease to low values. Alkaline phosphatase shows a similar pattern of activity from 13 to 29 weeks’ gestation, but thereafter activity increases to term; this late increase is mainly related to the heat-labile particulate form of alkaline phosphatase. Total and heat-labile alkaline phosphatase alone or expressed as a ratio with gamma-glutamyltransferase can be used with or as an alternative to lecithin/sphingomyelin ratios in the investigation of fetal lung maturity. A total alkaline phosphatase activity of 0.36 mukat/L and an alkaline phosphatase/gamma-glutamyltransferase ratio greater than 2 indicate pulmonary maturity.