bluuebunny/crossref_metadata_2025 huggingface dataset:
Automated Colorimetric Method for Estimating Serum Triglycerides
Authors: McLellan G H
Published: January 2020

A colorimetric adaptation of the fluorometric method of Noble and Campbell is described. Decreased sensitivity, caused by substituting colorimetry for fluorometry, has been improved by increasing the proportion of serum to isopropanol extraction fluid from 1 in 21 to 1 in 11, and by placing an adjustable range expander between colorimeter and recorder. This accurate and reliable adaptation has obviated the need for an expensive fluorometer.
Rapid Identification and Quantitative Determination of Barbiturates and Glutethimide in Blood by Gas—Liquid Chromatography
Authors: MacGee Joseph
Published: January 2020

Barbiturates and glutethimide can be identified and measured in whole blood, plasma, or serum in 20 min. An internal standard containing known amounts of five common barbiturates is added to the sample, the sample is acidified, and the sedatives are extracted rapidly into toluene, then from the toluene into a small volume of aqueous tetraethylammonium hydroxide. An aliquot of this last extract is introduced directly into the gas chromatograph, where the barbiturates are converted to their ethyl derivatives and separated on a silicone column. They are identified by observing which of the internal standard peaks has increased and measured by measuring the extent of increase. Glutethimide can be determined on the same chromatogram. Mephobarbital and phenobarbital can be simultaneously determined.
Profile of Volatile Metabolites in Human Urine
Authors: Zlatkis Albert , Liebich Hartmut M
Published: January 2020

Volatile constituents of 30 urines from 10 adults have been studied by gas chromatography, and two also by mass spectrometry. The sample was prepared by extracting urine with ethyl ether, distilling the extract at low temperature under reduced pressure, and concentrating the distillate to a few microliters. High-efficiency capillary columns, 150 m x 0.5 mm i.d., provide the resolution necessary to indicate the presence of some 300 compounds, 40 of which have been identified by mass spectrometry. These include ketones, alcohols, lactones, terpenes, furans, dimethyl sulfone, pyrrole, and allyl isothiocyanate. Dietary changes have a relatively small effect on the profile of the volatiles, and interindividual patterns are very similar. These facts make analyses of this kind of potential diagnostic use.
Instrument Design Considerations and Clinical Applications of Stable Isotope Analysis
Authors: Klein Peter D , Haumann Joseph R , Eisler William J
Published: January 2020

Stable isotope analysis by gas chromatography-mass spectroscopy-accelerating voltage alternation (GMA) is a new concept, which makes it possible to eliminate radiological hazard from clinical tracer studies. To become useful to, and used by, the clinician, this instrumentation must eventually become competitive with that for liquid scintillation counting from the standpoint of sample size, sensitivity, automation, routine operation, and cost. A second-generation instrument, recently constructed in the Division of Biological and Medical Research at Argonne National Laboratory, has been put into operation and is being used in collaborative clinical studies conducted at the Mayo Clinic. The design features and operating characteristics of this system are discussed with reference to the ultimate clinical requirements.
Influence of a Chemically Defined Diet on the Composition of Serum and Urine
Authors: Young D S , Epley Jean A , Goldman Peter
Published: January 2020

We have studied the effects of ingestion of a chemically defined diet on the constituents of serum and urine of five normal volunteers. The diet, believed to meet all human nutritional requirements, caused a decrease in serum cholesterol and urea nitrogen and an increase in serum phosphate, uric acid, and creatinine. Urinary creatinine is unchanged from that of a random diet but urinary electrolytes, urea, and uric acid decrease to a new stable value, which is achieved after four days. High-resolution techniques have been used to measure the carbohydrate-containing constituents of urine and those that can be detected by their ultraviolet absorbance or their reaction with ninhydrin. A considerable decrease in the number of these urinary constituents is effected by the chemical diet within four days, but even by this time all compounds attributable to the random diet may not have been completely eliminated. Many urinary components that persist while the subjects are on the simplified diet have been tentatively identified.
Changes in the Saccharoid Fraction in Rats with Alloxan-Induced Diabetes or Injected with Epinephrine
Authors: Alam M Jafar , Rahman M Ataur
Published: January 2020

"Saccharoid fraction," defined as the nonglucose reducing substances in blood, increases both in hyperglycemia (blood glucose concentration exceeding 280 mg/dl) and hypoglycemia (blood sugar less than 65 mg/dl) in rats. This increase is not completely accounted for by glutathione, glucuronic acid, ascorbic acid, uric acid, and creatinine. Some of the constituents of saccharoid fraction seem to be insulin-sensitive. Alloxan not only produces diabetes in rats but also increases blood glucuronic acid, ascorbic acid, and uric acid. Estimated constituents of saccharoid fraction account for only 45% to 75% of the saccharoid fraction. The unaccounted-for saccharoid fraction shows changes similar to those in the accounted-for saccharoid fraction, in the diabetic rats, as was also the case after treatment with insulin of normal or diabetic animals. The fraction not accounted for by the estimated constituents may represent the reducing sugar phosphates present in the blood.
A Simplified Radioimmunoassay for Human Pituitary Luteinizing Hormone in Serum
Authors: Levine Robert A , Donabedian Richard K , Sobrinho Luis G
Published: January 2020

A simplified radioimmunoassay is described for human pituitary luteinizing hormone (LH). The principal modification over existing methods is that talc is used to separate antibody-bound hormone from free hormone by adsorption of the latter. Serum concentrations of LH in normal males, ovulatory females (follicular phase), postmenopausal females, patients with primary gonadal failure, and patients with hypopituitarism averaged 4.7, 4.6, 26.4, 30.8, and 1.9 µg of reference std. LER 907 per 100 ml of serum, respectively (10.3, 10.1, 57.8, 67.5, 4.2 milli-int. units/ml, respectively). These values are consistent with the clinical diagnoses.
Manual and Automated Determination of Immunoglobulins in Unconcentrated Cerebrospinal Fluid
Authors: Savory J , Heintges M G , Killingsworth L M , Potter J M
Published: January 2020

Manual procedures have been developed for determination in human cerebrospinal fluid of the immunoglobulins IgG, IgA, and IgM. An automated continuous-flow procedure for determination of IgG in human CSF is also described. The immunoglobulins are quantitated in both cases by immunoprecipitin reactions, with use of commercial antiserum. Values determined for the immunoglobulins by the manual method correlate with values for gamma globulin obtained by electrophoresis. The values for IgG from the manual method also correlate with IgG values determined by the automated procedure. The precision of duplicate determinations with the manual procedures for IgG, IgA, and IgM is 3.4, 1.8, and 1.0% (relative standard deviation), respectively, and that for lgG with the automated system is 3.48%.
Estimation of Normal Ranges from a Controlled Sample Survey. I. Sexand Age-Related Influence on the SMA 12/60 Screening Group of Tests
Authors: Reed A H , Cannon D C , Winkelman J W , Bhasin Y P , Henry R J , Pileggi V J
Published: January 2020

A panel of 13 clinical chemical tests was performed on sera from 1419 clinically normal adults, utilizing the SMA 12/60 AutoAnalyzer, to obtain practical normal range estimates by nonparametric statistical methods. Serum samples were obtained over a period of 14 months from eight geographic areas of the United States. Normal range estimates are derived for the entire group surveyed, for subgroups of males and females, and for various age categories within each of the two subgroups. For each panel test, sexand age-related variation is assessed by using nonparametric statistical tests for identity of normal-range endpoints. Derived normal ranges that are practical for clinical laboratory usage are proposed. Finally, a measure of validity of our estimates of normal range is applied.
Clinical Nephelometry: 1. New, Accurate, Heat-Precipitation Nephelometric Method for Rapid Determination of Plasma Fibrinogen
Authors: Rice Eugene W , Muesse D E R
Published: January 2020

We have developed an accurate procedure for measurement of plasma fibrinogen. Turbidity resulting from heating (56°C, 20 min) plasma diluted with a new "zwitterionic" buffered-saline reagent (pH 5.6) is nephelometrically measured (600 nm). We evaluated the method both by confirming the accuracy of its prestandardization and calibration on a new clinical nephelometer, and by comparative standardization by use of a conventional spectrophotometer. The nephelometer is more sensitive and gives a linear response over a wide range of concentrations. Representative information supporting the broad clinical utility of the determination of plasma fibrinogen is illustrated. These assays should be a significant complement to muititest biochemical screening of both healthy and hospitalized individuals.
Screening of 563 Students for Cholinesterase Variants
Authors: Becker Charles E
Published: January 2020

Of 563 dental students screened for cholinesterase variants, 97.2% were homozygotes for the usual cholinesterase (E1uE1u), 2.1% were heterozygotes for the usual and the dibucaine-resistant cholinesterases (E1uE1a), and 0.7% were heterozygotes for the usual and the fluoride-resistant cholinesterases (E1uE1f).
Rapid Analysis for Total Mercury in Urine and Plasma by Flameless Atomic Absorption Analysis
Authors: Kubasik Norman P , Sine H E , Volosin Michael T
Published: January 2020

A rapid, simplified method is described for analysis for total mercury in urine and plasma. A sulfuric acid—potassium permanganate digestion of small sample volumes efficiently prepares them for measurement of both organic and inorganic mercury, which can be done at the rate of about 100 samples per hour.
Haptoglobin Phenotype Frequencies in Mentally Retarded Persons
Authors: Rundle A T , Clothier B , Sudell Barbara
Published: January 2020

Haptoglobin phenotype frequencies for 887 unselected mentally retarded patients were within the range reported for normal European populations. Of these sera, 2% initially classified as anhaptoglobinemic by subjective appraisal of starch-gel electropherograms were subsequently shown to be hypohaptoglobinemic. This frequency of hypohaptoglobinemia is similar to that reported for normal populations. Sixteen of the hypohaptoglobinemic cases were reinvestigated, and all but one showed some evidence of hepatic dysfunction.
Biological Applications of the Carbon Rod Atomizer in Atomic Absorption Spectroscopy. 2. Determination of Copper in Small Samples of Tissue
Authors: Stevens Brian J
Published: January 2020

A simple technique is presented for the analysis for copper in small fragments of tissue. Dissolution of the tissue in concentrated nitric acid is the only preparative step required. Copper content is then determined by comparison with standards, by using the carbon rod atomizer previously described. Sample volumes of less than 2 µl are used for each measurement. The method gives results that compare well with both colorimetric and flame atomic absorption methods, and also with neutron activation analysis, and appears to be applicable to the analysis of other metals in tissue.
Pathophysiological Aspects of Catecholamine Production
Authors: von Euler U S
Published: January 2020

The production and function of catecholamines and their variation during various normal and abnormal conditions are discussed.
Manual Spectrophotometric and Fluorometric Determination of Tocopherol in Cerebrospinal Fluid
Authors: Vatassery G T , Mortenson G A
Published: January 2020

Methods are reported for the manual spectrophotometric or fluorometric estimation of tocopherol in human cerebrospinal fluid. The fluid is centrifuged, an equal volume of ethanol is added, and the tocopherol is extracted with hexane, which is then used for the direct estimation by fluorometry. The fluorescence of tocopherol is significantly affected by the proportion of ethanol in the hexane solvent. The standards used for comparison should therefore be dissolved in hexane that had been previously equilibrated with twice its volume of ethanol:water (1:1 by vol). For spectrophotometry, the original hexane extract is dried at 40°C under reduced pressure, the residue dissolved in hexane, and color developed by adding bathophenanthroline, ferric chloride, and orthophosphoric acid. The color is measured at 536 nm. Concentrations of tocopherol in the spinal fluid samples analyzed so far ranged from 40 to 210 µg/ liter.
Isolation and Measurement of Pancreatic Amylase in Human Serum and Urine
Authors: Fridhandler L , Berk J Edward , Ueda M
Published: January 2020

We describe a sensitive quantitative procedure for separating isoamylases in human serum, urine, and tissue homogenates. Two components have been discerned with chromatographic characteristics resembling those of pancreatic and salivary amylases, respectively. Several lines of evidence—derived from studies in normal subjects, pancreatectomized patients, and patients with acute pancreatitis—indicate that the pancreas is probably the source of the component in serum and urine that exhibits characteristics of pancreatic amylase. The source of the component resembling salivary amylase has not yet been fully defined. Isoamylase analysis of extracts of fallopian tube and liver revealed two amylase components with chromatographic properties similar to pancreatic and salivary amylases, respectively.
Simple Automated Spectrophotometric Method for Assay of Trypsin and Chymotrypsin in Duodenal Juice
Authors: Vandermeers A , Vandermeers-Piret M-C , Rathé J , Christophe J
Published: January 2020

Trypsin and chymotrypsin were automatically assayed by a simple spectrophotometric method, with specific ester derivatives as substrates. Samples containing 0.25 to 2.5 enzyme units in 0.5 ml were analyzed at a rate of 40 to 60 assays per hour, each sample being incubated for 6 min. The acidity developed during esterolysis was measured, with phenol red as the acid—base indicator. The full-scale deflection of the recorder, corresponding to 0.5 absorbance at 420 nm, was obtained with a sample containing 5 U of enzyme per milliliter, incubated in Tris-HCl buffer (25 mmol/liter, pH 8.0), in the presence of phenol red (124 µmol/liter). This variation corresponded to a decrease of 0.4 pH unit.
Effect of Some Drugs on Clinical Laboratory Values as Determined by the Technicon SMA 12/60
Authors: Singh H P , Hebert M A , Gault M H
Published: January 2020

We examined the quantitative in vitro effects of 45 drugs on 12 automated biochemical laboratory tests done on the Technicon SMA 12/60. Of these, 25 drugs in 1 mmol/liter concentration interfered in one or more of the assays. However, only eight drugs (N-acetyl-p-aminophenol, p-aminosalicylate, isoniazid, L-dopa, α-methyldopa, 6-mercaptopurine, sulfathiazole, and ascorbic acid) reacted positively with the test reagents at concentrations likely to occur in plasma after administration of maximum single therapeutic doses. A slight false elevation of plasma uric acid and a major false increase in urine values occurred in patients after ingestion of N-acetyl-p-aminophenol and phenacetin, corresponding to the greater concentrations of these drugs and their metabolites in urine. The relative importance of various factors affecting the influence of drugs on biochemical test values is discussed.
Rapid Large-Scale Screening of Blood Proteins by Use of Cellulose Acetate Electrophoresis on a Solid Support
Authors: Nerenberg Samuel T , DeMarco Linda , Ganger Carolyn
Published: January 2020

We describe a new principle of cellulose acetate electrophoresis (solid-support electrophoresis), in which cellulose acetate membranes are given a solid support, instead of being suspended as heretofore. The new technique is particularly well suited for screening procedures, because many samples can be processed economically on a single run. Also described for the first time, in conjunction with solid-support electrophoresis, is a method of (a) simultaneously using continuous and discontinuous buffer systems with specially (series) oriented membranes, or (b) a single-sample application for fractionating different constituents simultaneously (proteins, lipoproteins, isoenzymes, etc.).
Tyrosinemia Induced by a Pyridoxine Antagonist, Desoxypyridoxine
Authors: Easton E Joanne , Simpson Ian , Martin J Kenneth , Campbell Donald J
Published: January 2020

Tyrosinemia was produced in Wistar rats by feeding a diet deficient in vitamin B6, and containing 1 mg of 4-desoxypyridoxine (DOP) per 100 g of diet. Concentrations of serum tyrosine were greatest in lactating rats, with smaller increases in nonpregnant, nonlactating females and adult males. Paper chromatography of urine indicated that DOP feeding also probably inhibits formation of most normal urinary metabolites of tyrosine. Livers of several rats showed no evidence of cirrhosis after 18 days on the diet containing DOP, indicating that this experimentally produced tyrosinemia is not a true model of tyrosinosis.
Single Radial Immunodiffusion of Undiluted Serum Proteins
Authors: Pizzolato M C B , Pizzolato M A , Agostoni A
Published: January 2020

A simple method is described for quantitative determination of IgG, IgA, IgM, α2M, and other proteins without dilution of the sample. Strips of gelatinized cellulose acetate spread with antiserum are used as a supporting medium. The method is accurate, highly reproducible, and seems particularly suitable for routine work because it permits determination of hypo-, normal, and hyperglobulinemia on a single strip.
An Automatic, Solid-State Direct Readout for the Buchler—Cotlove Chloridometer
Authors: Zettner Alfred , Fontana Walter C
Published: January 2020

An automatic, solid-state direct-readout system was built for the Buchler—Cotlove chloridometer. The device, described in detail, makes it possible to decrease sample size and titration time. The speed of chloride determinations with use of this device is tripled, while precision is significantly improved.
Determination of Total Urinary Protein by Combined Gel Filtration and Automated Biuret Reaction
Authors: Doetsch Karl
Published: January 2020

Gel filtration was used to remove non-protein-bound substances that interfere with measurement of urinary protein by an automated version of the biuret reaction. Nearly 98% of the protein was accounted for, and accuracy and precision were acceptable. Interference from bile pigments or hemoglobin pigments can be eliminated, and specificity is increased.
A "Wash-out Pipet System" for Sampling Red Blood Cells
Authors: Stoler Richard G
Published: January 2020

A "Wash-Out Pipet System" is described for sampling erythrocytes in heparinized blood. Packed red blood cells are drawn into a 1.0 ml pipet, washed out of the pipet, and diluted to at least 50 ml, causing the cells to lyse. The pipet is blown dry with air and is ready for use again in less than 20 s.
Semiautomated Method for Measurement of Guanidinosuccinic Acid in Serum
Authors: Kamoun P P , Pleau J M , Man N K
Published: January 2020

A semiautomated method for analysis of guanidinosuccinic acid is described. To separate it from interfering guanidino compounds, it is absorbed on and eluted from an anion-exchange column. Colorimetry of the eluate was by Barrit’s [J. Pathol. Bacteriol. 42, 441 (1936)] modification of the Voges-Proskauer reaction.
Successive Determination of Na+, Cl-, and H+ Activities on the Skin Surface with Ion-Selective Electrodes
Authors: Green Marvin , Behrendt Hans , Libien Gloria
Published: January 2020

A method is described for the rapid sequential measurement of Na+, Cl-, and H+ activities on the skin surface with ion-selective electrodes. Rationales are given for details of technique such as temperature control, use of a conducting bridge, pH-dependence of sodium electrode performance, and the uniform electrode setting for all tests. Data on reproducibility document the precision of the method when applied to measurements on the skin surface. Reasons are given why Na+ and Cl- activity measurements on the skin require a different design and interpretation than skin pH determinations.
Spectrophotometry of Proline in Plasma and Urine
Authors: Goodwin Jesse F
Published: January 2020

A procedure is presented for proline quantification in serum filtrates and urine hydrolysates. Interference from primary amino acids is greatly reduced by nitrozation. After nitrozation and neutralization, proline is reacted with ninhydrin in a concentrated electrolyte solution. The resulting red proline—ninhydrin product is salted out, extracted into benzene, and measured at 520 nm. The extent and nature of interference from various amino acids have been determined, as has the effect of urinary constituents. Procedural variables have also been studied. Preliminary data are presented for urinary proline/creatinine ratios for 6-to 12-month-old infants.
Simple Automated Determination of Serum or Plasma Glucose by a Hexokinase/Glucose-6-Phosphate Dehydrogenase Method
Authors: Neeley William E
Published: January 2020

A simple, fast, efficient, and accurate automated method is described for determining the quantity of glucose in 50 µl of serum or plasma. A hexokinase/glucose-6-phosphate dehydrogenase reaction requiring incubation at room temperature is used. The method is specific for glucose, and is not affected by increased concentrations of endogenous chemical substances in uremic sera or by several common drugs that interfere with other glucose methods. Results of parallel assays, in which glucose oxidase and o-toluidine are used, are compared.
Nucleic Acid Concentrations in Normal Human Plasma
Authors: Kamm Richard C , Smith Albert G
Published: January 2020

Utilizing a simple, rapid, and inexpensive modification of a fluorometric method, we determined the normal concentrations of nucleic acids (DNA and RNA) in human blood plasma of healthy individuals. DNA concentrations (13.9 ± 3.7 mg/ liter) were in excellent agreement with those reported by other methods. However, the RNA concentrations (144 ± 22 mg/liter) we found were higher than previously reported values, possibly because ribonuclease activity is more inhibited in this fluorometric method.
Optimal Conditions for the Kinetic Assay of Serum Glutamate Dehydrogenase Activity at 37°C
Authors: Ellis Graham , Goldberg David M
Published: January 2020

Optimal concentrations of ammonium ions, 2-oxoglutarate, and NADH were defined for serum glutamate dehydrogenase (EC 1.4.1.2) activity at 37°C. Substrate inhibition was not observed with the last two compounds. The pH optimum in triethanolamine buffer is 7.4, and activity is inhibited by increasing the buffer concentration beyond 50 mmol/liter. Activation by ADP exceeds that promoted by L-leucine, and there is little advantage in having both present. Activity is linear with time and with enzyme concentration to a limiting absorbance change of 0.300 at 340 nm, and precision was satisfactory. Data indicate the normal range to lie between 0 and 4 U/liter.
Detection of Patients with Low Serum Cholinesterase Activity: Inadequacy of "Acholest" Method
Authors: Dietz Albert A , Rubinstein Herbert , Lubrano Tina
Published: January 2020

The "Acholest" test-paper method for estimating serum cholinesterase activity has been suggested as a preoperative screening test for patients potentially liable to prolonged apnea after use of succinylcholine. The method was tested on selected sera from normal persons and from patients with various hereditary variants of serum cholinesterase and results were compared to those obtained with a standard quantitative assay. The Acholest method failed to detect 12 of 20 cases at high risk of prolonged apnea after succinylcholine. It cannot therefore be considered as a suitable screening procedure.
Simplified Serum Phosphorus Analyses by Continuous-Flow Ultraviolet Spectrophotometry
Authors: Amador Elias , Urban Jackie
Published: January 2020

Serum phosphorus can be measured by continuous-flow uv spectrophotometry without reduction of the phosphomolybdate complex. The dilute sample is dialyzed into dilute (1 ml/100 ml) sulfuric acid, then mixed with an ammonium molybdate— sulfuric acid—"Tween 80" solution. The absorbance of the sample peaks is measured at 340 nm with a linear-absorbance spectrophotometer. Peak heights are directly proportional to concentration, because logarithmic conversion is performed within the spectrophotometer. The method obeys Beer’s law up to 10 mg of P per deciliter, and results correlate closely with those for standard methods based on reduced phosphomolybdate blue. The miniature manifold uses a 12-in. dialyzer. The sampling rate can be 60 to 120 samples per hour when a Gilford one-piece debubbler flow cell is used.
Automated Method for Screening Urine for Amphetamine and Some Related Primary Amines
Authors: Rutter E R
Published: January 2020

This paper describes an automated method for extracting and detecting amphetamine and some related primary amines in urine. In the technique the color reaction given by primary amines with 2,4,6-trinitrobenzene sulfonic acid is used, and is sufficiently sensitive to detect the excretion of therapeutic doses of amphetamine. Samples of 4 ml of urine may be analyzed at a rate of 20 samples per hour, and the method is suitable for inclusion in a multi-channel drug-screening system.
Some Methodological Modifications of the Technicon "SMA 12/60 AutoAnalyzer" System
Authors: Bigat Tevfik K , Saifer Abraham
Published: January 2020

Methodological modifications have been made in our "SMA 12/60 AutoAnalyzer" system, to improve the reproducibility and accuracy of six commonly performed procedures. These include glucose with the glucose oxidase method, albumin with the bromcresol green method, and alkaline phosphatase with the sodium thymolphthalein monophosphate method. We have also modified the composition of the reagents used in the determination of protein, inorganic phosphate, and aspartate aminotransferase. A general approach that is useful for adapting a new method to a multichannel AutoAnalyzer system is discussed.
Development of a Miniature Fast Analyzer
Authors: Burtis C A , Mailen J C , Johnson W F , Scott C D , Tiffany T O , Anderson N G
Published: January 2020

Design features and operation of a prototype miniaturized Fast Analyzer are described, and some results obtained with it are presented. The Analyzer occupies only one cubic foot of space. It has a 17-cuvet plastic rotor that rotates through a stationary optical system at speeds up to 5000 rpm. The resulting centrifugal force is utilized to transfer and mix a series of sample(s) and reagent(s) into the cuvets. The ensuing reactions are monitored spectrophotometrically, and the data evaluated in real time by an on-line computer. Samples (1 to 10 µl) and reagents (70 to 110 µl) are loaded into the rotor either discretely or dynamically; various rotor configurations can be used to do this. Many of the standard clinical analyses, including most of the NADH-linked enzymatic analyses, have been adapted for use with this analyzer. Precision obtained ranges from 1 to 4%. This report considers, specifically, analyses of some serum enzymes. Results show that the small analyzer possesses the previously demonstrated advantages of Fast Analyzers and, in addition, has several beneficial features arising from miniaturization.
Modified Automated Determination of 2,3-Diphosphoglycerate in Whole Blood
Authors: Atkinson Kenneth F
Published: January 2020

A modification is described of the automated determination of 2,3-diphosphoglycerate (DPG) in blood [Grisolia, S., et al., Anal. Biochem. 31, 235 (1969)]. Modifications in the manifold result in a sensitive, noise-free, rapid system and the modifications in the preparations of the reagents ensure stability of the diluted standards and blood samples for at least three weeks. Samples are run at the rate of 60/h and sample size can be as small as 5 µl of whole blood. The coefficient of variation of the overall determination of automated DPG and manual hemoglobin is 3.6% and the SD is ±0.77 µmol/g Hb. The normal range is 14.6 ± 2.2 (SD) µmol/g hemoglobin.
An Error-Producing Interaction in an Automated Method for Measuring Cholinesterase Activity in Blood
Authors: Ellin Robert I , Groff William A , Kaminskis Andris
Published: January 2020

Blood cholinesterase activity values obtained in our laboratory by the automated procedure of Levine et al. (Automat. Anal. Chem., Technicon Symp. 1965) are greater than those values obtained by a comparable manual method. This problem is caused by reaction of the standard (reduced glutathione) with the substrate (acetylthiocholine) to form acetylglutathione and thiocholine. Because thiocholine dialyzes about three times more rapidly than glutathione in the automated system and gives the same color reaction, proportionately higher activity values would be reported. Ways of correcting this problem are presented.
Rapid, Simplified Method for Measuring Total Hepatic Cholesterol
Authors: Naito Herbert K , Lewis Lena A
Published: January 2020

Because determinations of hepatic total cholesterol are frequently needed, an automated, continuous-flow method would be useful to have available. Hepatic total cholesterol is extracted with isopropyl alcohol in one step and the extract is then quantitatively analyzed by an accepted AutoAnalyzer procedure for serum total cholesterol. Homogenization of the tissue eliminates the use of proteolytic enzymes or KOH for the digestive process. The one-step extraction of total cholesterol with isopropyl alcohol simultaneously precipitates interfering proteins. Addition of FeCl3 color reagent to an aliquot of clear extract produces a stable color with a density proportional to the amount of cholesterol present, which can be quantitatively detected by a colorimeter and recorded on a graphic recorder. This automated method eliminates tedious, time-consuming processes, and can greatly increase the reliability and accuracy of hepatic total cholesterol determinations. This method is shown to be rapid, reproducible, and simple. The procedure is adapted for both wet tissue and lyophilized samples, the latter giving slightly more reproducible results.
Reporting Terminal for Sequential Multiple Analysis and a Positive Identification System for Serum Specimens
Authors: Kaufman James H
Published: January 2020

The Sequential Multiple Analysis Reporting Terminal (SMART) and the Bio-Logics Specimen Identification System have been interfaced with the SMA 6/60 and the SMA 12/60. This installation, first of its kind, accurately converts and condenses SMA output into compact, easily read reports, with concomitantly increased efficiency in serum handling and accuracy in patient identification.
Multichannel Analyzer Featuring Ultrahigh Stability Photometry: Application to Enzyme Determination
Authors: Pardue Harry L , Miller Michael M
Published: January 2020

An instrument system has been developed for the simultaneous photometric monitoring of multiple sample channels. Salient features of the system include ultrahigh photometric stability, random access to individual channels, electronic channel selection, wavelength selectivity among the different channels, and either manual or computercontrolled operation. The system implemented in this work consists of 10 sample channels arranged radially around a single stabilized source. It has been evaluated for the kinetic determination of alkaline phosphatase in reconstituted sera. The drift of the photometer averages less than 0.03% T (1.3 x 10-4A) per hour. Assay values for alkaline phosphatase exhibit standard deviations of 2% or less in most cases.
Comparison of Ascorbic Acid Concentrations in Whole Blood Obtained by Venipuncture or by Finger Prick
Authors: Bradley Daniel W , Maynard James E , Emery Gladys
Published: January 2020

Vitamin C (ascorbic acid) concentrations in whole blood obtained by finger prick or by venipuncture have been shown to be equivalent when measured by the 2,4-dinitrophenylhydrazine procedure. Whole blood obtained by either technique is stable for at least 6 h at 25°C, and for as long as 28 days when stabilized with trichloroacetic acid and stored at 4°C. Storage of whole blood at -70°C is accompanied by an initial loss (10-20%) of vitamin C; however, additional losses of vitamin C do not occur beyond the third day of storage.
Rapid Spectrofluorometric Assay for Total Bile Salts in Bile
Authors: Mroszczak Edward J , Riegelman Sidney
Published: January 2020

An assay is presented for total bile salts in bile. The procedure involves one precipitation and extraction step and then treatment with concentrated sulfuric acid to produce fluorescent products, which are then measured at an excitation wavelength of 470 nm and emission wavelength of 505 nm. With sodium taurocholate as the standard (fluorescence intensity of 1.00), the average fluorescence intensity of equimolar concentrations of the taurine and glycine conjugates of cholic, deoxycholic, and chenodeoxycholic acid is 1.01 (standard dev., 0.05). The average recovery of the six bile salts from pooled rat bile is 95.7% (standard dev., 8.5). The assay compares well with the established gas—liquid chromatographic and enzymatic methods, but it is simpler, faster, less costly, and just as reliable as the alternative methods.
Enzymes in Cancer
Authors: Schwartz Morton K
Published: January 2020

Since Warburg and his associates reported in 1924 that cancer tissue exhibits a greater rate of aerobic glycolysis than normal tissue, there have been numerous efforts to define enzymatic defects in cancer tissue. Attempts have been made to use enzyme assays in the diagnosis of cancer and in following the course of the disease. This review considers in this regard the role of organ-specific enzymes (amylase, phosphohydrolases, etc.) as well as the more ubiquitous glycolytic enzymes. The usefulness of the assay of isoenzymes in serum, as well as in tissue of cancer patients, is discussed and the role of enzymes in chemotherapy considered
AutoAnalyzer Assay for Serum Alkaline Phosphatase Activity, with Sodium Thymolphthalein Monophosphate as Substrate
Authors: Proksch Gary J , Bonderman Dean P , Griep John A
Published: January 2020

An automated method is described for determining alkaline phosphatase activity in serum, with use of sodium thymolphthalein monophosphate as the substrate. The system makes use of standard AutoAnalyzer components, has a simple flow diagram, and does not involve dialysis. The method has good precision, and the results correlate well with those from the manual method of which it is an adaptation
Sensitive Fluorometric Method for Determination of Quercetin in Plasma or Urine
Authors: Gugler R , Dengler H J
Published: January 2020

A fluorometric method is described for determining quercetin, a flavonoid compound, in plasma and urine. It is based on the formation of the highly fluorescent quercetin-tetraphenyldiboroxide complex. The excitation wavelength used is 445 nm, the emission wavelength 500 nm.
Specific Photometric Determination of 5-Hydroxyindoleacetic Acid in Urine
Authors: Goldenberg Harry
Published: January 2020

Udenfriend‘s nitrosonaphthol test for 5-hydroxyindoleacetic acid (5-HIAA) is subject to interference by urinary phenolic acids and drug metabolites. Studies in our laboratory have shown that the specificity and sensitivity of the nitrosonaphthol reaction with 5-hydroxyindoles can be greatly enhanced by the addition of 2-mercaptoethanol. This observation serves as the basis of a simple, improved method for the photometric determination of urinary 5-HIAA. The 5-HIAA is extracted from urine and transferred to a colorimeter tube. Treatment with nitrosonaphthol and nitrous acid results in formation of Udenfriend’s violet chromophore, which is converted to an intense blue chromophore upon addition of mercaptoethanol. Extraneous colors caused by reactive phenols and indoleacetic acid in urine are destroyed at this point by the mercaptoethanol. The intensity of the remaining blue color is proportional to the 5-HIAA concentration. Recoveries of added 5-HIAA by the proposed method are quantitative. The normal 24-hour excretion values obtained for human subjects fall in the range of 0.8 to 6.0 mg (95% confidence limits), with a mean of 3.9 mg. Drugs that produce a false positive test for intestinal carcinoid with earlier photometric methods have no effect on the new method
Application of Fe(II)-5-Pyridyl Benzodiazepin-2-ones to the Manual or Automated Determination of Serum Uric Acid
Authors: Klein Bernard , Lucas Lois B
Published: January 2020

A new coupled-ferricyanide-redox reaction has been developed for the manual and automated determination of serum uric acid. The 580-nm absorbance of the photometric end point, formation of the violet-blue Fe2+-5-pyridyl benzodiazepin-2-one chelate, is proportional to uric acid concentration. Replicate manual analyses are precise (CV = 1.2%) and reproducible from day-to-day (CV = 3.2%). Adapted to automated (AutoAnalyzer) operation, replicate analyses also show good precision (CV = 1.03%) as well as good day-to-day reproducibility (CV = 3.35%). Recovery of added uric acid averaged 98.5% (range: 92.7-107.5%) in the manual procedure and 99.9% (range: 96.6-103.3%) in the automated mode. Formaldehyde, commonly used to preserve uric acid solutions, has been shown to interfere with recovery analyses in the automated analyses. Results obtained by the present procedure and reference carbonate-phosphotungstate and uricase methods agree well
Increased Aspartate Aminotransferase Activity of Serum after in Vitro Supplementation with Pyridoxal Phosphate
Authors: Rej Robert , Fasce Charles F , Vanderlinde Raymond E
Published: January 2020

We examined the effect of pyridoxal phosphate supplementation on the apparent aspartate aminotransferase (EC 2.6.1.1.) activity of human serum. Supplementation by 25 µmol/liter effected an average increase of 16% in the results for kinetic assay. The increase was not the result of increased enzymatic or nonenzymatic blanks, and, within a small range, sample dilution had no significant effect. Part of the increase was attributable to the enzyme being protected against the loss of activity that occurs during preincubation with L-aspartate. A similar increase was not demonstrated in a two-point colorimetric method, perhaps because of the short reaction time, without preincubation, and the initial presence of both substrates in the assay. We attempted to Correlate such stimulation of aminotransferase activity and the patient’s diagnosis or treatment. Pyridoxal phosphate should be included in the reaction mixture when aspartate aminotransferase activity is being measured clinically
Computer-Controlled Instrument System for Sequential Clinical Chemical Testing. I. Instrumentation and System Features
Authors: Toren E Clifford , Carey R Neill , Cembrowski George S , Schirmer James A
Published: January 2020

Instrumentation and software of a computer-controlled system for analytical chemistry is described, which will: (a) automatically carry out any one of a large number of tests, (b) utilize the results of that test in conjunction with data derived from other sources as a basis to proceed to select and perform another analysis, and (c) continue in this mode by a branching sequence until the analytical potential of the specimen is exhausted. The system is programmable with user control languages that require no programming experience. The external equipment controlled by the computer in a time-sharing mode includes a sampler, a digital pipet, a digital valve, a ratemeter, and a dual-beam spectrophotometer with a programmable wavelength drive.
Kinetics of the Cholesterol-Sulfuric Acid Reaction: A Fast Kinetic Method for Serum Cholesterol
Authors: Hewitt Thomas E , Pardue Harry L
Published: January 2020

We studied the kinetics of the reaction between cholesterol and sulfuric acid in acetic acid-acetic anhydride medium. Results have been used to establish near-optimal conditions for the fast kinetic determination of cholesterol in serum. The reaction rate measured during the first 20 s of the reaction is proportional to cholesterol concentration. There is good agreement (<2% deviation) between pseudo-first-order rate constants for cholesterol standards and sera. Recoveries of standard cholesterol added to sera range from 99% to 104% (average, 100.7%). Values for serum cholesterol by this kinetic determination tend to be somewhat lower than equilibrium values reported by local hospital laboratories. Whether bilirubin interferes depends on reaction conditions; under optimal conditions, each milligram of bilirubin is kinetically equivalent to about 1 mg of apparent cholesterol. Kinetic data are included to show how results are degraded by operating under nonoptimal conditions, and considerations involved in changing experimental conditions are discussed.
Improved Techniques for Assessment of Serum Lipoprotein Patterns. II. Rapid Method for Diagnosis of Type III Hyperlipoproteinemia without Ultracentrifugation
Authors: Wieland Heinrich , Seidel Dietrich
Published: January 2020

Based on the previously described technique [Clin. Chem.19, 737 (1973)] of precipitating plasma lipoproteins with polyanions after their electrophoretic separation in gels, a new method is presented for diagnosing type III hyperlipoproteinemia without need for ultracentrifugation or immunologic techniques. Used in the procedure are 0.1 mol/liter MgCl2, 1.5 g/liter heparin, and 10 g/liter NaCl to visualize selectively the very-low-density lipoproteins in agarose gel after electrophoresis. The technique is simple, inexpensive, accessible to every laboratory, and provides the answer in less than 2 h after electrophoresis of the patient’s whole serum. The results obtained are the same as those obtained by ultracentrifugation followed by lipoprotein electrophoresis of the isolated fractions.
A Turbidimetric Continuous-Flow System for Immunochemical Quantitation of Blood Proteins by Use of a Modified Photometer
Authors: Blom Mogens , Sørensen Darly
Published: January 2020

In a continuous-flow procedure, the turbidity resulting from the reaction between albumin and transferrin and specific anti-human sera has been measured in a photometer constructed for the purpose. Incorporation of two photoelectric cells and a special bridge built between the photometer and the recorder made possible the amplification of the sensitivity by as much as 30-fold. Further, a more economical intermittent flow of antiserum was used. The standard deviations for sera analyzed in duplicate (day-to-day) were 1.4 and 0.05 g/liter, respectively, for albumin and transferrin determinations. Values obtained by this method correlated well with values obtained by the electroimmunotechnique.
Urinary Proteins Studied by Use of Isoelectric Focusing. I. Tubular Malfunction in Association with Exposure to Cadmium
Authors: Vesterberg O , Nise G
Published: January 2020

Isoelectric focusing in thin-layer polyacrylamide gel has been applied to studies of urinary proteins. We could differentiate the following patterns: tubular, glomerular with high and low selectivity, as well as mixed glomerular and tubular patterns, as seen in some cases of chronic pyelonephritis and uremia. The typical tubular-protein patterns—i.e., as developed in association with cadmium exposure—were characterized by elevated excretion of β2-microglobulin. Possibly the severity of renal malfunction can be assessed by the isoelectric focusing technique. To identify the protein zones, we in some cases complemented isoelectric focusing with electrophoresis at right angles in acrylamide gel and also in agarose gel containing antibodies to provide additional information.
Assessment of the Need for Triglyceride Blank Measurements
Authors: Rautela Gopal S , Slater Suzanne , Arvan Dean A
Published: January 2020

Two methods of triglyceride blank measurement were critically investigated. For 38 samples a mean blank value of 7.2 mg/dl was obtained when the blanks were measured by replacing the saponifying reagent with 80% isopropanol. For the same samples, consistently higher blank values were obtained (mean = 18.3 mg/dl) when these were determined by the Kessler-Lederer method. It is suggested that, when true blank values are desired, the former method is to be preferred. Based on theoretical considerations, however, as well as on our experimental data on the effect of in vitro hydrolysis on triglyceride blank measurements, we recommend that in routine triglyceride measurements, blank determinations are not needed.
Use of "Sephadex G-15" in an Improved Method for Estrogens in Pregnancy Urine
Authors: Quek Evelyn S C , Buttery J E , de Witt G F
Published: January 2020

A simple, rapid, and reliable colorimetric method has been developed for determining total estrogens in the urine of pregnant women. It is essentially a modification of the procedure of Van Baelen et al. [J. Clin. Endocrinol.27, 1056 (1967)], in which gel adsorption is used as a purification step after enzymatic hydrolysis. Three major modifications have been made to the original procedure, whereby a single determination can be completed within 4 h. Actual manipulative time of the analysis is only 2 h, and one technician can easily handle an average of 10 cases per batch. Precision of the method is good, the coefficient of variation being less than 5%. Recovery of added estriol is better than 95%. The method can be used for measuring estrogen excretions ranging from 0.5-50 mg/24 h. We have found it very suitable as a routine assay in our laboratory.
Use of a Sodium Chloride—Phosphate Buffer for pH Standardization in a New Blood-Gas Analyzer with an Isotonic Sodium Chloride Bridge
Authors: Drinker P A , Noonan D C , Ramanaiah N , Tole J R
Published: January 2020

Two different blood-gas analyzers were tested to determine the effects on blood pH measurement of changing the reference bridge solution from saturated KCl to normal saline (0.16 mol of NaCl per liter). This change, which necessitated the preparation of modified buffers equimolal in NaCl with respect to blood, virtually eliminated salt depletion of the bridge solution and improved the stability of the liquid-junction potential between the bridge solution and the sample. The instruments we used were the Corning 165 pH Blood Gas Analyzer and the Radiometer E5021 pH Electrode with PHM72 Acid Base Analyzer. Comparison of results on clinical blood samples indicates that performance with the modified bufferbridge system is the same as that obtained with the conventional scheme. Analytical performances of the Corning and Radiometer instruments for PO2 and PCO2, as well as for pH, were comparable.
A Test for Bacterial Alkaline Phosphatase: Use in Rapid Identification of Serratia Organisms
Authors: Wolf Paul L , Von der Muehll Elisabeth , Praisler Karen
Published: January 2020

This investigation concerns identification of alkaline phosphatase production by bacterial organisms, as detected by a blue color resulting from conversion of indolyl phosphate to indigo. Coagulase-positive Staphylococcus produced alkaline phosphatase; coagulase-negative Staphylococcus did not. Serratia did not produce alkaline phosphatase; those Enterobacteriaceae we tested did. Thus, this test rapidly differentiates these organisms, diminishing the time for identification of Serratia in the clinical laboratory by 48 h. Identification of Serratia should not be ignored, because it is a life-threatening complication for certain hospitalized patients.