bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interference by acetaminophen in the glucose oxidase-peroxidase method for blood glucose determination.
Authors: Kaufmann-Raab I , Jonen H G , Jähnchen E , Kahl G F , Groth U 
Published: January 2020

Abstract
Acetaminophen, p-aminophenol, and oxyphenbutazone interfere with the glucose oxidase/peroxidase method for glucose. Structurally related compounds that lack a free phenolic hydroxyl group (acetanilide, aniline, and phenylbutazone) do not interfere. During the analytical procedure acetaminophen is consumed. One mole of acetaminophen leads to an apparent loss of four moles of glucose. The hexokinase/glucose-6-phosphate dehydrogenase method (Boehringer Hexokinase method) is not affected by these substances.
Simple modification of a liquid scintillation counter to decrease cost of and time for radioimmunoassay.
Authors: Dixon R , Cohen E 
Published: January 2020

Abstract
A simple, inexpensive modification in the elevator mechanism of a liquid scintillation counter allows for radioimmunoassay tubes (12 X 75 mm) containing the antibody-bound radioligand to be counted directly, thereby obviating the need for counting vials and considerably decreasing the amount of fluor used. Furthermore, because assay and counting are all done in the same tube, the modification shortens assay time and increases precision by avoiding what is often the most time consuming and inaccurate step, the transfer of antibody-bound radioligand to a counting vial. We find that use of this modification results in about a 75% decrease in the overall cost for materials and a substantial decrease in assay time.
Use of gas chromatography and mass spectrometry to analyze underivatized volatile human or animal constituents of clinical interest.
Authors: Politzer I R , Dowty B J , Laseter J L 
Published: January 2020

Abstract
The study of volatilizable components in human and animal samples by gas chromatography and mass spectrometry is reviewed for the years 1970--1975. Only naturally volatile, underivatized compounds are considered, from sources such as body fluids, tissues, and breath. Where possible, the clinical samples are discussed in terms of normal profiling, aberrations associated with disease states, and specific compound analyses. A brief descriptive technical section is included, stressing types of sample preparation currently being used.
Laboratory confirmation of the diagnosis of cystic fibrosis.
Authors: Tocci P M , McKey R M 
Published: January 2020

Abstract
The recent commercial introduction of a method for detecting albumin in meconium makes screening for cystic fibrosis feasible for many hospitals. If the tests is adopted, confirmatory tests should be available. Quantitative analyses of sweat for sodium by flame photometry and for chloride by silver titration and ion-sleective electrodes are now used as confirmatory tests. We compare results of these confirmatory methods applied to presons with cystic fibrosis, respiratory disorders, or digestive disorders, and to control subjects.
Gas-chromatographic identification of drugs in gastric aspirate samples: a rapid screening procedure for emergency toxicology.
Authors: Abramson F P 
Published: January 2020

Abstract
Gastric aspirate has not been used frequently in the identification of ingested drugs. Because there is only qualitative significance in such a sample, a new method is described that facilitates identification. A 1-ml gastric aspirate sample is extracted with 100 mul of chloroform and analyzed directly by gas chromatography. Seventeen drugs commonly involved in overdose cases are included in this 25-min procedure. The gastric drug screen has been applied to more than 500 patients, and results are described.
Radioimmunuassay compared to thin-layer and gas--liquid chromatography for detecting methadone in human urine.
Authors: Roerig D L , Wang R I , Mueller M M , Lewand D L , Adams S M 
Published: January 2020

Abstract
Radioimmunoassay was compared to thin-layer and gas--liquid chromatographic methods for detection of methadone in the urine of patients undergoing methadone maintenance therapy as treatment of heroin abuse. With urine samples known to contain methadone, 84% were positive by thin-layer chromatography as compared to 99% positives by the other two methods. This difference is attributed to the difference in sensitivity of the three methods. All three methods gave consistently positive results with urine samples from patients receiving 25 mg of methadone per day or more. With smaller daily doses the percentage of positive results obtained with thin-layer chromatography decreased. Analysis of urine samples not containing methadone showed no incidence of cross reaction of other drugs with the methadone radioimmunoassay. The methadone radioimmunoassay appears to be both sensitive and reliable; however, certain other factors limit its use as a primary screening method.
Relationship between erythrocyte 2,3-diphosphoglycerate and age in a normal population.
Authors: Kalofoutis A , Paterakis S , Koutselinis A , Spanos V 
Published: January 2020

Abstract
The concentration of 2,3-diphosphoglycerate in erythrocytes was determined in 369 male and 376 female normal subjects, 1 to 86 years of age, derived from the Greek population. It was inversely correlated (P less than 0.01) with age. Persons over age 60 showed a decrease (P less than 0.05) in 2,3-diphosphoglycerate concentrations as compared those 1-20 years of age.
Interferences with the starch-iodine assay for serum amylase activity, and effects of hyperlipemia.
Authors: Gitlitz P H , Frings C S 
Published: January 2020

Abstract
Recent reports imply or claim that amylase activity is inhibited in hyperlipemic sera, because diluted samples showed greater activities when assayed by a starch-iodine method. We find that dilutions of both clear and lipemic samples give higher-than-expected activities when assayed by a starch-iodine method, an effect attributable to the variable effects of protein, turbidity, and triglycerides in the hyperlipemic samples. Thus the starch-iodine method is unsuitable for assessing the effects of hyperlipemic samples on amylase activity. To do so, we used an alternative method, in which soluble dyed amylopectin is used as the substrate. This method exhibits apparent zero-order kinetics, and we detected no interfering factors. Plots of sample volume (x) vs. activity (y) for clear and hyperlipemic (triglycerides up to 80 g/liter) sera gave straight lines with y-intercepts of zero. Evidently hypertriglyceridemia does not inhibit amylase activity.
Screening for erros in galactose metabolism with the erythrocyte.
Authors: Rabinow B E , Wong P W , Maschgan E R , Natelson S 
Published: January 2020

Abstract
We propose determination of the ratio of the rate of galactose metabolism to glucose metabolism by erythrocytes as a screening test for abnormalities in glucose and galactose metabolism. Packed erythrocytes (20 mul) are incubated for 1 h at 37 degrees C in 0.42 ml of a solution comprising phosphate buffer (pH 7.4), 0.4 mg of glucose, 60 mg of methylene blue, and 50 nCi of either [1-14C]glucose or [1-14C]galactose. Metabolism is then stopped by injecting dilute H2SO4 through a rubber septum sealing the flasks. On incubating the acidified solution for 1 h, the evolved CO2 is trapped in a well containing ethanolamine, which is suspended from the septum. The radioactivity of the well and its contents is measured in a scintillator, and from these data CO2 is calculated. (The scintillation medium is preheated with ethanolamine to eliminate chemiluminescence.) For normal adults mean values for CO2 are 0.468 mumol/liter of erythrocytes per minute for galactose and 37.8 mumol/liter of erythrocytes per minute for glucose. Homozygous galactosemics exhibit no galactose metabolism but the rate for flucose metabolism is normal. Results for parents of homozymotes are described. We review various causes for galactosemia and point out that transfer of galactose through the cell wall and into the erythrocyte is markedly reduced in certain cats and, although unreported, may possibly be a cause for galactosemia in humans.
Evaluation of a new blood-collecting device ("microtainer") that is suited for pediatric use.
Authors: Hicks J M , Rowland G L , Buffone G J 
Published: January 2020

Abstract
We evaluated the prototype of a "Microtainer" (800-mul) tube (Becton-Dickinson Co., Rutherford, N.J. 07070), In which a semi-solid silicone material is used to separate serum from erythrocytes on centrifugation. We compared results for 18 serum analytes with those obtained for specimens collected by the "dripping" method of capillary blood collection. The serum was examined microscopically for platelets and leukocytes from both normal and leukemic specimens. The cellular elements were all contained in the erythrocyte layer. Hemolysis was negligible. Means for paired samples did not differ significantly, except for Na+, for which the difference was not clinically significant. Values for potassium and lactate dehydrogenase were unchanged 24 h after collection, even though the serum was left in the collecting device.
Improved batch and column separation in the assay of hemoglobin A2.
Authors: Morin L G 
Published: January 2020

Abstract
Hemoglobin A2 is a batch fractionated on a column containing diethylaminoethyl-cellulose (DE52, Whatman) with a discontinuous buffer system at pH 8.9 and 7.3. A short micro-column method is also presented, which allows separation in less than 30 min with no interference from hemoglobin S. Both methods clearly distinguish normal from thalassemia specimens, and are simpler and more rapid than previously published methods.
Automated enzymatic determination of L-lactate in serum, with use of a miniature centrifugal analyzer.
Authors: Hadjiioannou T P , Hadjiioannou S I , Brunk S D , Malmstadt H V 
Published: January 2020

Abstract
We describe an automated enzymatic reaction-rate method for spectrophotometric determination of lactate in serum with a miniature centrifugal analyzer. The L(+) -lactate is selectively oxidized in the presence of lactate dehydrogenase (EC 1.1.1.27) and NAD+ to form NADH, which is measured from its absorption. Reaction rates are determined automatically, and unknown concentrations are calculated from a computer-generated calibration curve with aqueous lithium lactate standards. Lactate concentrations in the range 0.32-1.6 mug/4 mul (80-400 mg/liter) of sample were determined with relative errors and coefficient of variation of 4.8%. Analytical recovery of lactate added to pooled serum was 89-112% (average, 101%). Comparison with a kit ("Rapid Lactate") method gave a correlation coefficient squared of 0.979 over a concentration range of 39-779 mg/liter.
Colorimetry of carbohydrates with m-aminophenol, and its proposed use in measurement of serum amylase activity.
Authors: Goodwin J F 
Published: January 2020

Abstract
In the reaction of m-aminophenol with carbohydrates in a thiourea/acetic acid reagent, addition of borate suppresses chromogen formation for hexoses and pentoses, and enhances it for disaccharides. All reaction products absorb maximally at 520 nm. The relatively greater intensity of the m-aminophenol/maltose reaction product was used in a saccharogenic method for amylase, with low blank readings. This method is compared with two dye/starch procedures.
Creatine kinase isoenzyme patterns in human tissue obtained at surgery.
Authors: Tsung S H 
Published: January 2020

Abstract
Chromatography on DEAE-Sephadex A-50 was applied to study the quantitative distribution of creatine kinase isoenzymes in extracts of human tissue obtained during surgery. The results are compared with those determined by an immunological method [Clin. Chim. Acta 58, 223 (1975)]. Conflicting results for some organs as reported by the two methods are probably attributable to postmortem autolysis.
An integrated approach to lipid profiling: enzymatic determination of cholesterol and triglycerides with a centrifugal analyzer.
Authors: Wentz P W , Cross R E , Savory J 
Published: January 2020

Abstract
We describe enzymatic methods for determination of cholesterol and triglycerides (triacylglycerols), adapted for use with a centrifugal analyzer. Triglycerides are determined by a two-point kinetic method, which utilizes a single glycerol standard for calibration and provides for a within-run reagent blank correction. The endpoint determination of cholesterol combines the unique blanking capabilities of the centrifugal analyzer to correct for sample and reagent blank interferences. Results correlate well with those obtained by procedures standardized by the Lipid Research Clinics Program for use with a continuous-flow system.
Evaluation of a dipstick test for glucose in urine.
Authors: Dyerberg J , Pedersen L , Aagaard O 
Published: January 2020

Abstract
As an example of qualitative tests, a dipstick analysis for glucose in urine has been tested for the influence of modifying factors on the test result. Two different types of dipsticks were examined, "Clinistix" and "S-Gluko-test." Used according to manufacturer's instructions, the latter is more sensitive and selective. By multivariance analysis the following variables were examined: urine samples, inter- and intra-analyst, exposure to light, and dipstick batch. The first three contributed significantly to the total variation in results, inter-specimen variation being the most important. With knowledge of the frequency of testing urines with a given glucose concentration and the probability of the result at that concentration, an expression of the probability of the glucose content of a urine sample can be obtained. Even with the tests of the type examined having a sensitivity and specificity exceeding 95%, 14 of 100 patients suspected of having diabetes mellitus on the basis of a dipstick examination will be found to have a urinary glucose concentration of less than 2 mmol/liter. These figures were found when the prevalence of urines with a glucose concentration exceeding 2 mmol/liter was 17.5%.
Effect of halothane anesthesia on muscle, liver, thyroid, and adrenal-function tests in man.
Authors: Johnstone R E , Kennell E M , Brummund W , Shaw L M , Ebersole R C 
Published: January 2020

Abstract
Seven healthy men volunteers received 6.6 +/- 1.3 (SD) percent-hours of halothane oxygen anesthesia without surgery. Serum bilirubin, alanine aminotransferase, and aspartate aminotransferase significantly increased after anesthesia, which may indicate subclinical liver-cell damage. Creatine kinase of skeletal muscle origin increased above 90 U/liter in six subjects, indicating subclinical muscle-cell damage. Cortisol, triiodothyronine uptake, thyroxine, and free thyroxine index increased significantly immediately after anesthesia. Serum bromide concentrations had increased by fivefold on the second day after anesthesia, and on the ninth day was still elevated fourfold. Oral temperatures increased 0.7 degrees C 6 h post-anesthesia, possibly because of increased thyroxine activity. Lactate dehydrogenase, hydroxybutyrate dehydrogenase and gamma-glutamyltransferase activities did not change significantly. No drugs administered during the course of this study chemically interfered with any of the test methods used.
Cholesterol in amniotic fluid, determined by gas chromatography.
Authors: Jones Owen V M , Ho F K , Mazzuchin A , Doran T A , Liedgren S , Porter C J 
Published: January 2020

Abstract
Cholesterol was extracted from amniotic fluid, saponified, converted to its trimethylsilyl derivative, and gas chromatographed, with cholesteryl acetate as the internal standard. The method is sufficiently accurate and precise for use with the range of concentrations of cholesterol found in amniotic fluid (5 to 48 mg/litre). Total cholesterol was measured in amniotic fluids collected at different stages of gestation. No significant trend or change was observed nor was cholesterol in the amniotic fluid and the mother's serum correlated at any stage of gestation. Thus we conclude that cholesterol is not a useful indicator of fetal age or maturity. Cholesterol concentrations in amniotic fluid from complicated pregnancies were within the range found for normal pregnancies.
Enzymatic method for determination of CO2 in serum.
Authors: Forrester R L , Wataji L J , Silverman D A , Pierre K J 
Published: January 2020

Abstract
We describe an enzymatic method, requiring only 10 mul of serum, for determining CO2 as bicarbonate or dissolved gas. Phosphoenolpyruvate carboxylase catalyzes the reaction of HCO3- with phosphoenolypyruvate to give oxalacetate. The resulting NADH, in the presence of malate dehydrogenase, is oxidized to NAD+, and the decrease in absorbance at 340 nm is directly proportional to the amount of CO2 present in the sample. Reaction is complete in 3 to 6 min under assay conditions, and is linearly related to CO2 concentrations between 8 and 65 mmol/liter. Analytical recovery is 95-110% (average, 101%). Two laboratories compared values obtained by continuous-flow analysis. The resulting correlation coefficients were 0.966 and 0.987, values for the t-test were t(paired) equals 0.473 and t(paired) equals 0.334, and average day-to-day precisions (three concentrations) were 3.9% and 4.2%.
Parallel electrophoretic fractionation of alkaline phosphatase and serum protein on cellulose acetate strips: clinical evaluation.
Authors: Burlina A , Galzigna L 
Published: January 2020

Abstract
We describe here a simple, time-saving method for separating alkaline phosphatases on cellulose acetate, with a parallel detection of serum protein pattern. The staining procedure is based on a coupling reaction between the reaction product of alpha-naphthol with Fast Red Violet LB. The enzymatic reaction is done by bringing the cellulose acetate strip containing the phosphatase band into contact with the surface of a solid agar/substrate mixture. The whole procedure requires 80 min. The method has some features in common with other recently proposed procedures but is more reproducible and rapid because of the choice of the reagents and an improved yield of the coupling step.
P-Hydroxybenzoic acid hydrazide procedure for serum glucose adapted to the Technicon "SMA 12/60," and compared with other glucose methods.
Authors: Ferraro J J , Caccavo F A , Saifer A 
Published: January 2020

Abstract
We adapted the p-hydroxybenzoic acid hydrazide procedure for serum glucose for use with the Technicon SMA 12/60 AutoAnalyzer. Like the o-toluidine method, this method is based on a general carbohydrate reaction except that it occurs in a mildly alkaline medium and the intense yellow color formed is measured at 400 nm. Advantages of this reagent over o-toluidine include lower cost, less toxicity, and higher purity. Aside from those carbohydrates that are present in serum in insignificant quantities, there are no interferences from various physiological compounds or drugs (hypoglycemic agents) found either in normal persons or diabetics. Within-run and day-to-day values had coefficients of variation of 1.39% and 3.44%, respectively; recoveries ranged from 100 to 102% (mean, 101%). Comparative data showed excellent agreement with the hexokinase (r equals 0.998; y equals 0.950x + 5.91) and glucose oxidase (r equals 0.996; y equals 0.986x + 5.34) enzymatic ("true") glucose methods, and with the o-toluidine procedure (r equals 0.998; y equals 0.979x + 3.14).
Lipoamide dehydrogenase in serum: a preliminary report.
Authors: Pelley J W , Little G H , Linn T C , Hall F F 
Published: January 2020

Abstract
Lipoamide dehydrogenase was identified in serum and the optimal conditions for its assay at 30 degrees C were defined. The pH optimum in tris(hydroxymethyl)aminomethane buffer is 7.8, and activity is inhibited if buffer concentration exceeds 100 mmol/liter. Saturating concentrations of the substrates NAD+ and lipoamide are 3 mmol/liter and 5 mmol/liter, respectively. Activity is decreased eightfold when lipoic acid is substituted for lipoamide. Activity is linearly related to enzyme concentration up to limiting absorbance change of 0.300 at 340 nm, and both within-day and day-to-day precision are satisfactory. Data suggest a normal range (2 SD) of 3-19 kU/liter. The highest value measured in serum was 473 kU/liter. A correlation with direct bilirubin concentrations (r equals 0.435, P less than 0.01) was found.
Modified colorimetric method for procainamide in plasma.
Authors: Sitar D S , Graham D N , Rangno R E , Dusfresne L R , Ogilvie R I 
Published: January 2020

Abstract
We describe a modified colorimetric method for determining procainamide in plasma by use of a diazotization and coupling reaction with N-(1-naphthyl)-ethylenediamine dihydrochloride (Marshall's reagent). The sensitivity of the assay is increased twofold over the originally reported colorimetric method, and the lower limit of detection for the assay of a 1.0-ml plasma sample has been decreased to 0.5 mg/liter.
Adaptation of blank-corrected methods for measurement of total and conjugated bilirubin and uric acid to the centrifugal analyzer.
Authors: Cross R E , Heintges M G , Savory J , Wentz P W 
Published: January 2020

Abstract
The blank-corrected determination in serum of total and conjugated bilirubin and of uric acid has been adapted to the centrifugal analyzer. Bilirubin is measured by a modified Jendrassik and Grof procedure; uric acid is determined kinetically by using a reaction based on reduction of ferric ion, including a uricase-treated blank. Sensitivity and precision of both methods are excellent, and results compare well with those obtained by commonly used procedures.
New techniques for ion-selective measurements of ionized calcium in serum after pH adjustment of aerobically handled sera.
Authors: Schwartz H D 
Published: January 2020

Abstract
I report further experience in measuring ionized calcium (Ca2+) with the AMT Electron System and its serum standards and solid-state, dip, calcium-selective electrodes. With this system, serum pH can be adjusted with CO2 gas and Ca2+ and pH simultaneously measured; when 5.2% CO2 (40 mm pco2) is used for sample equilibration, the standard bicarbonate concentration is also provided. I measured serum Ca2+ as a function of pH between pH 7.0 and 9.0 and found the relationship to be reproducible, with no evidence of irreversible complexing of Ca2+. When the pH of aerobically exposed, mailed sera was restored to the original values, their values for Ca2+ were the same as for the fresh sera. Measurement of Ca2+ in routinely (aerobically) handled sera after pH restoration with CO2 gas was therefore validated, both samples from within an institution and mailed specimens. Standardization to pH 7.40 is recommended for routine measurements, is generally more accurate than use of heparin or quasianaerobic techniques, and is a practical approach. In patients with possible uncompensated acid-base disturbance (which may be indicated by an abnormal standard bicarbonate concentration if not suspected clinically), patient pH should be measured independently as part of the usual strict, anaerobic blood-gas-analysis procedures. Abnormal patient pH must be considered in the interpretation of Ca2+ results determined at pH 7.40 which are borderline or slightly abnormal; most accurately, Ca2+ may be measured in the separated sera at the previously determined patient pH value. Studies of aqueous solutions with the currently used Ca2+ electrodes showed a selectivity coefficient (the constant which relates the activity of an interfering ion to the activity of calcium that would contribute the same emf) KNa=0.0031 +/- 0.0003 (SE) and KMg=0.046 +/- 0.004 (SE). At physiological concentrations of Ca2+, physiologically encountered variation in Na+ is of no significance in resulting Ca2+, but extreme variation in Mg2+ may cause an error of approximately 1%.