bluuebunny/crossref_metadata_2025 huggingface dataset:
Concurrent Assay of Phenobarbital and Diphenylhydantoin in Plasma by Vapor-Phase Chromatography
Authors: Van Meter J C , Buckmaster H S , Shelley L L
Published: January 2020

The weakly acidic phenobarbital and diphenylhydantoin, separated from interfering substances by simple solvent partition, are estimated concurrently by vapor-phase chromatography. Solid sample injection and internal standard (primidone) are used. The entire procedure can be completed within 2 h after venipuncture. Both drugs could be measured after therapeutic doses have been administered.
Adaptation of the Zak-Epstein Automated Micromethod for Serum Iron to Determine Iron-Binding Capacity and Urinary Iron
Authors: Kunesh Jerry P , Small Larry L
Published: January 2020

An automated method has been developed for determining serum iron-binding capacity and urinary iron as well as serum iron. After preliminary preparation, the sample is treated with ascorbic acid in hydrochloric acid to release and reduce protein-bound iron, then singly dialyzed into an acetate buffer and reacted with 4,7-diphenyl-1,10-phenanthroline (bathophenanthroline) to form a pink color proportionate to the amount of iron present. The sample passes through a 15-mm flow cuvet and is read at 537.5 nm, with the range expander set at either 2x or 4x.
Determination of Diazepam (Valium) Concentrations in Serum by Gas—Liquid Chromatography
Authors: Foster Lowell B , Frings Christopher S
Published: January 2020

A simple, rapid, and precise gas chromatographic method for determination of serum diazepam concentrations is described. Two milliliters of serum is extracted with chloroform, and the extract is concentrated and injected into a gas chromatograph. Of the many drugs and serum samples tested, none interferes with the determination of diazepam.
Simultaneous Spectrophotometric Determination of Glutethimide and Barbiturates
Authors: Dain David W , Trainer Thomas D
Published: January 2020

A simple, rapid, quantitative method for the simultaneous analysis of barbiturates and glutethimide (2-ethyl-2-phenylglutarimide) is described. The procedure involves a single chloroform extraction from a sample buffered at pH 7.4 and requires less than an hour.
Nomogram for Calculation of Concentration for Colorimetric Systems in which Absorbance Decreases Linearly as Concentration Increases
Authors: Gindler E Melvin
Published: January 2020

A nomogram is presented for use in calculating concentrations for colorimetric systems having an inverse linear relationship between absorbance and concentration. An example is given of its use for the calculation of glucose concentration. The nomogram is sufficiently accurate for clinical use, and can be rapidly used.
A Semiautomated Method for Determining Amylase Activity in Serum and Urine
Authors: Lott John A , Mercier Joan E
Published: January 2020

Serum or urine is incubated at 50°C with a substrate containing dextrin. The endogenous glucose and reducing sugars liberated from the substrate by amylase are separately determined on the AutoAnalyzer by use of alkaline potassium ferricyanide. Optimum conditions and limitations were evaluated. The method is compared to those of Henry and Chiamori (Somogyi) and Fishman and Doubilet. Normal values for serum and urine are presented.
Disappearance of Glutathione from Serum or Hemoglobin Solutions
Authors: Sass Martin D
Published: January 2020

Glutathione disappears as a soluble, nonprotein component after it has been added to serum, either in the reduced (GSH) or oxidized (GSSG) form. When GSH is added to serum it is rapidly oxidized to GSSG by some dialyzable component of serum. Glutathione is lost because of interaction of serum proteins with the GSSG formed in this manner or added directly. A similarly rapid loss of glutathione occurs in the presence of hemoglobin only if acetylphenylhydrazine is also present. This loss of glutathione in the presence of a redox drug is the result of a direct interaction between GSH and hemoglobin, in contrast to the reaction occurring in serum. The implications of these findings for hematologic disease are discussed.
Detection of Atypical Cholinesterase by an Automated pH Stat Method
Authors: Ashby Thomas M , Suggs Joseph E , Jue Danny L
Published: January 2020

Plasma pseudocholinesterase has no known physiological role but is essential for the rapid degradation of succinylcholine, a muscle relaxant used in surgical procedures. Depression of effective enzyme concentrations as a result of hepatocellular disease or exposure to anticholinesterase agents will increase the patient’s sensitivity to succinylcholine and prolong postoperative apnea. Synthesis of this enzyme is controlled by an autosomal gene with multiple variant alleles; individuals phenotypically homozygotic for one of these variants will have either qualitatively "atypical" pseudocholinesterase with decreased activity or no enzyme at all, and will thus be more sensitive to succinylcholine. The automated pH stat system described here detects atypical cholinesterase by measuring the degree of inhibition of butyrylcholine hydrolysis by dibucaine. The sensitivity and reproducibility of this technique equals that of standard spectrophotometric methods and its speed is comparable to that of the most rapid screening tests. A family pedigree is also presented, exemplifying a rare genotype in which two siblings are double heterozygotes for "atypical" and "silent" alleles.
Automation of a Quantitative Immunochemical Microanalysis of Human Serum Transferrin: A Model System
Authors: Eckman Irving , Robbins John B , Van den Hamer C J A , Lentz John , Scheinberg I Herbert
Published: January 2020

The quantitative immunochemical determination of human serum transferrin was automated with a 100-µl sample. The estimated standard deviation from the true value was 7.9 mg/100 ml in 21 samples of serum, which had transferrin concentrations of 139-325 mg/100 ml.
A Bench-Top, Automated, High-Resolution Analyzer for Ultraviolet Absorbing Constituents of Body Fluids
Authors: Pitt W Wilson , Scott Charles D , Johnson Wayne F , Jones Guy
Published: January 2020

An automated, high-resolution chromatograph capable of separating as many as 150 ultraviolet-absorbing molecular constituents of body fluids has been previously developed. A smaller, improved version of this analyzer, which uses only one-eighth of the previously required quantity of ion-exchange resin, sample, and eluant, is described. Analysis time has been decreased from 40 to 20 h. A prototype system of this analyzer, which will fit on an ordinary laboratory bench top, has been built and is now being tested. The small prototype analyzer uses a folded, 0.22-cm ion-exchange column for separation and a recently developed dual-beam, dual-wavelength, uv-flow photometer for detection. A unique device has been developed to generate the buffer concentration gradient used in eluting the ion-exchange column. Analyses of body fluids with this prototype are comparable to those achieved with the larger analyzers.
Automated Simultaneous Determination of p-Acetylaminohippurate and Inulin in Serum
Authors: Looyé A
Published: January 2020

An automated determination of p-acetylaminohippurate in serum is described. It is combined with an existing procedure for determining inulin to give a simultaneous method. The same manifold can also be used to determine p-aminohippurate in combination with fructose by omitting hydrolysis. The results of automated and manual determination are compared. Recoveries of p-acetylaminohippurate and p-aminohippurate added to serum were quantitative.
Chemical versus Spectrophotometric Determination of Bilirubin in Amniotic Fluid, and the Influence of Hemoglobin and Metheme Pigments
Authors: Kapitulnik J , Kaufmann N A , Blondheim S H
Published: January 2020

Methemoglobin and methemalbumin markedly diminish the measurements by spectrophotometry of the change in absorbance at 450 nm (ΔA450) in amniotic fluid but do not affect the chemical (diazo) determination of bilirubin. The converse was true of hemoglobin. In 72 of 82 specimens there was no gross contamination of amniotic fluid with these pigments and the two types of bilirubin determination agreed well (r = 0.98, p<0.001) when a slight modification of the Malloy-Evelyn method was used (1 volume of amniotic fluid was diluted to 3 volumes before addition of reagents). In the other 10 cases the presence of metheme pigments significantly decreased the ΔA450, but in none of the 82 specimens was there sufficient free hemoglobin present to depress significantly the results of the chemical determination, although it can do so if enough is present.
Plasma Vitamin A Assay by Fluorometry and Use of a Silicic Acid Column Technique
Authors: Garry Philip J , Pollack J Dennis , Owen George M
Published: January 2020

We investigated a new procedure in which silicic acid column chromatography and fluorometry are used to assay plasma vitamin A. Using tritium-labeled vitamin A acetate and vitamin A alcohol as radioactive standards, we identified two fluorescent components in plasma extracts chromatographed on silicic acid columns. One unidentified fluorescent component was eluted first with hexane or petroleum ether. Vitamin A, the second fluorescent peak, was quantitatively eluted with isopropanol. The isopropanol eluates could be immediately assayed fluorometrically without further treatment. The unidentified compound was sensitive to ultraviolet irradiation, which destroyed it slower than vitamin A is destroyed. Values correlated well for plasma vitamin A concentrations, determined by this procedure and by the Neeld and Pearson modification of the Carr-Price colorimetric method (r = 0.871). By our technique, we found 34 µg of vitamin A per 100 ml of plasma in 778 preschool children.
Origin of the Lag Phase of Continuous-Flow Analysis Curves
Authors: Thiers Ralph E , Reed Allen H , Delander Karen
Published: January 2020

Physical and mathematical models are presented that account for the lag phase in the curves of transition between steady states in continuous-flow analysis. Experimental conditions are described that produce pure lag-phase curves, separated from the exponential phase with which they are combined in routine practice. The data quantitatively support the expectations from the models, and provide a means for measuring interslug transfer of fluid in bubbled streams. Others observed earlier that lag phase is associated with the bubbled stream and the dialyzer, whereas the exponential phase is associated with nonbubbled streams and debubbler [Clin. Chim. Acta 27, 421 (1960)]. Our theory and experiments confirm these earlier observations, and may provide deeper understanding of the processes involved in, and design requirements for, continuous-flow analysis.
Practical Aspects of a Measurement Technique for Calcium Ion Activity in Plasma
Authors: Radde I C , Höffken B , Parkinson D K , Sheepers J , Luckham A
Published: January 2020

We have evaluated the effects of the following on ion-specific electrode measurement of calcium ion activity in plasma: blood or plasma was stored in various ways for various periods of time, or exposed to air, or small amounts of heparin were added to the blood. Blood may be stored for as long as 120 min at room temperature before calcium ion activity changes measurably, but plasma stored for 20 min already has a slightly increased pH and decreased Ca ion activity. If plasma is frozen or refrigerated anaerobically after being collected, calcium ion activity is not measurably altered, but storage at room temperature is not suitable. If as much as 30 USP units of heparin is added per milliliter of blood and the blood is exposed to air for 1 min, calcium ion activity is unaltered, which allows rapidly processed samples to be used. Therefore, blood obtained by heel- or finger-prick may appropriately be used to measure calcium ion activity, particularly in newborns and infants.
Ca, P, and pH Relationships During Spontaneous Phosphaturia
Authors: King J S , Rhyne A Leonard
Published: January 2020

Data on phosphaturic urine are examined for statistical correlations among total and precipitated Ca and P, pH, Ca/P, and percentage of total Ca and P precipitated.
Currents in Renal Stone Research
Authors: King J Stanton
Published: January 2020

Current theories of renal stone formation are reviewed, together with the resulting proposals for treatment, with emphasis on the idiopathic, recurrent formation of calcium oxalate stones. Factors influencing the initiation and development of stones are discussed.
Formation and Stabilities of Free Bilirubin and Bilirubin Complexes with Transition and Rare-Earth Elements
Authors: Velapoldi Rance A , Menis Oscar
Published: January 2020

We investigated complexes formed between bilirubin and transition or rare-earth elements, and their relative stabilities. Relative rates of complex formation were analogous to metalloporphyrin and metal complex stabilities, according to the Irving—Williams series. Transition metals that formed strong, square planar complexes caused rapid bilirubin degradation. Iron(II) was oxidized to iron(III) in the bilirubin complex. Of the lanthanide complexes, only samarium(III) showed covalent bonding tendencies. Comparative molar absorptivities were calculated for several of the metal— bilirubin complexes. The stability of bilirubin in several solvents and under various experimental conditions is reported. At room temperature, bilirubin photooxidizes to biliverdin on exposure to laboratory light.
Automated Determination of Urinary Inorganic Sulfates with the "AutoAnalyzer"
Authors: Dieu J P
Published: January 2020

A turbidimetric method for inorganic sulfates in urine, based on the precipitation of barium sulfate, is adapted to the AutoAnalyzer. Coating of the flowcell with BaSO4 is avoided by an inter-sample air rinsing. Sampling rate is 40/h.
Separation and Identification of Urinary Constituents by Use of Multiple-Analytical Techniques
Authors: Mrochek J E , Butts W C , Rainey W T , Burtis C A
Published: January 2020

High-pressure anion-exchange chromatography with gradient elution has been used to resolve ultraviolet-absorbing constituents from normal and pathologic specimens of human urine. We have identified 50 of these constituents by using multiple-analytical techniques. Ultraviolet spectral maxima, gas chromatographic methylene unit (MU) retention values (for trimethylsilyl derivatives), and the major mass spectral peaks are reported for each of the identified compounds.
Application of Fe(II)-5-Pyridyl-Benzodiazepin-2-ones to the Automated Determination of Plasma or Serum Glucose
Authors: Klein Bernard , Lucas Lois B
Published: January 2020

A new coupled redox reaction, developed for the determination of glucose content of plasma or serum, has been adapted to automated operation. Resuits obtained by the automated and manual versions of the technique agree well. The glucose procedure has been combined with an automated urea nitrogen technique, to enable both constituents to be measured simultaneously.
A Manual and Automated Procedure for Measuring Serum Cholinesterase Activity and Identifying Enzyme Variants
Authors: Garry Philip J
Published: January 2020

A simplified manual and automated method is described for measuring serum cholinesterase activity and identifying the homozygous "usual," heterozygous, and homozygous "atypical" forms of the enzyme. With butyrylthiocholine as substrate at pH 7.4, the activity is determined in two 0.05 mol/liter buffer systems, Tris and phosphate. The "usual" enzyme has the same activity in both buffer systems. The phosphate buffer inhibits the heterozygous enzyme about 13% and the "atypical" enzyme about 43% relative to its activity in Tris buffer. The range of normal serum cholinesterase values (measurements on plasma from 1842 preschool children) is 2.10 to 5.25 U (mean, 3.67 U). In this population, 3.28% of the Caucasians, but only 0.29% of the Negroes, were heterozygous for the trait.
Automated Procedure for Simultaneously Measuring Total Globulin and Total Protein in Serum
Authors: Savory John , Heintges M Geraldine , Sobel Robert E
Published: January 2020

An automated continuous-flow procedure has been developed for simultaneously measuring total serum protein and globulin. The method for total protein is a minor modification of an existing automated method in which the biuret reagent is used. Total globulin is measured by reaction with glyoxylic acid, and standardized with N-acetyltryptophan. An empirical factor relating concentration of N-acetyltryptophan to human globulin has been derived. Values for total serum globulin obtained by this new automated procedure correlate closely with values obtained by electrophoresis, but do not agree with values obtained by use of procedures involving binding of anionic dye. Recovery of gamma globulin added to serum is essentially quantitative; the day-to-day precision (CV) is 4.31%.
Urinary Estrogen Determination in Pregnancy
Authors: Howarth A T , Robertshaw D M
Published: January 2020

Results of an extensive trial of a quick fluorometric determination of estriol in pregnancy urine are described. The method is compared with the much more laborious one of Oakey et al. [Clin. Chim. Acta 15, 35 (1967)]. Trial of another apparently simpler method indicated it to be unsatisfactory in practice. The method described is accurate, simple, and rapid.
Isolation of Glycoproteins from Human Gastric Juice and Saliva by Density Gradient Ultracentrifugation
Authors: Denborough M A , Presser J C , Ungar Berta
Published: January 2020

Density gradient equilibrium ultracentrifugation has been used successfully to isolate the glycoproteins from human gastric juice and saliva. Analysis of the fractions obtained by this method has shown that blood-group substance glycoproteins are the major component of glycoprotein secretion in both gastric juice and saliva. The technique also separates intrinsic factor and the nonspecific B12-binding substance from the blood-group substance glycoproteins in gastric juice. The nonspecific B12-binding substances in both gastric juice and saliva have a similar density and appear to consist of a single family of molecules.
Direct Photometric Determination of Globulin in Serum
Authors: Goldenberg Harry , Drewes Patricia A
Published: January 2020

A convenient method for direct photometric determination of total globulin in serum has been developed using a one-tube, one-reagent system. The analysis is based on a variation of the Hopkins-Cole reaction, in which glyoxylic acid condenses with the tryptophan residues present in globulin to produce a purple color. In the presence of copper and under the conditions of the analysis, color intensity is proportional to serum globulin concentration. The method is standardized with either a serum control or a suitable tryptophan derivative (e.g., acetyl-DL-tryptophan). There is little or no interference from free tryptophan, albumin, bilirubin, lipemia, or mild hemolysis. The precision of the method is ±3% (95% confidence limits), and results agree with those obtained by the salt fractionation method of Wolfson et al. [Amer. J. Clin. Pathol. 18, 723 (1948)]: t = -0.88; critical t = 2.02; 95% confidence limits.
An Improved Method for Measuring Blood Concentrations of Phenylpyruvic Acid
Authors: Coburn S P , Mahuren J D , Fuller R W
Published: January 2020

We describe an improved determination of phenylpyruvic acid (PPA) in blood plasma by ultraviolet spectrophotometric measurement of an enol— borate complex. Sensitivity and recovery are well suited for accurate analysis in the range of 1.25 to 25 mg/liter. Sera from 10 fasting phenylketonuric subjects averaged 15.3 mg/liter (range, 4.8 to 25.0 mg/liter). A pronounced diurnal rhythm in plasma PPA, with peak concentrations occurring between noon and 6 p.m., was detected in patients with untreated phenylketonuria.
Simplified Manual Micromethod for Determination of Serum Triglycerides
Authors: Soloni Felix G
Published: January 2020

This rapid, simplified assay for serum triglycerides is based on the use of a more effective solvent extraction procedure, ethoxide transesterification, and color development with acetylacetone. No phospholipid adsorption step is necessary. The procedure requires less than 0.2 ml of serum, no expensive or elaborate apparatus, and 5 to 10 values can be obtained per hour, with better precision than with most existing methods. Recovery averaged 99.9%. There are practically no interferences. Results correlated excellently with those obtained by the classical Carlson-Wadström method.
Determination of Testosterone Binding Affinity, 17β-ol Androgens, and Free Androgen Index in Hirsute Women
Authors: Pohlman Carol , Chen Jeffrey C , Zorn Elinor M , Wieland Ralph G
Published: January 2020

Possibly the concentration of free 17β-ol androgens in blood may be more critical than the total circulating concentration in helping to explain female hirsutism. Total serum 17β-ol androgens were measured by radioimmunoassay in eight hirsute females. Testosterone binding affinity was assayed in dilute serum with use of Florisil. From this we calculated a free 17β-ol androgen index (FAI). When compared with concentrations obtained in normal menstruating females, both values were significantly elevated. Adrenocortical suppression resulted in a significant decrease in both 17β-ol androgens and FAI in the hirsute patients. Thus, we find the determination of 17β-ol androgens to be as valuable as the FAI in evaluating female hirsutism.
Increased Rate of Analysis by Use of a 42-Cuvet GeMSAEC1 Fast Analyzer
Authors: Burtis C A , Johnson W F , Attrill J E , Scott C D , Cho N , Anderson N G
Published: January 2020

Sample analysis rate for a GeMSAEC Fast Analyzer is directly proportional to the number of sample cuvets contained in each rotor. GeMSAEC Fast Analyzers are available having either 15-, 16-, or 30-place rotors. To increase the sample analysis rate, an advanced GeMSAEC Fast Analyzer has been designed and fabricated that uses a 42-place rotor. The 42-place rotor, in order to accommodate the increased number of cuvets, is a modified enlargement of the previously described 15-place rotor [N. G. Anderson, Science 166, 317(1969)]. The hardware of the 42-place system is fully compatible with the existing GeMSAEC computer module, and existing software used in the 15-place system has been modified for use with the 42-place system. Results obtained for various chemical and enzymatic analyses are discussed.
Programming Concepts for the GeMSAEC Rapid Photometric Analyzer
Authors: Kelley Myron T , Jansen J M
Published: January 2020

Programming in a modified conversational interpretive language such as FOCAL provides the flexibility that is desirable when using the GeMSAEC Analyzer to develop analytical methods. Three approaches to the problems of interfacing the GeMSAEC Analyzer to a PDP-8/I computer and the modifications required to the FOCAL language are briefly summarized. The configurations of the computers and peripheral devices are: a 4K PDP-8/I with 32K disk and X-Y plotter, an 8K PDP-8/I with two 32K disks and storage oscilloscope, and an 8K PDP-8/I with cartridge tape storage and a refreshed oscilloscope display.
High-Resolution Chromatographic System for Measuring Organic Acids in Biological Samples
Authors: Rosevear John W , Pfaff Kenneth J , Moffitt Emerson A
Published: January 2020

A chromatographic system for organic acids has been developed, with improved stability, resolution, and sensitivity for measuring organic anions in biological samples. A calibration mixture containing 100 nEq each of 18 organic anions was clearly resolved, with a signal-to-noise ratio greater than 100:1. The baseline was essentially flat throughout the chromatogram. With scale expansion, the sensitivity limit was about 0.2 nEq per constituent. The width of each peak at half its height was 1 to 2% of its retention time. The system could thus resolve 50 or more constituents. In chromatograms of whole blood and urine more than 40 compounds are resolved. The system is basically a liquid-liquid partition between an acidified aqueous phase on silicic acid and a gradient of nonpolar and polar solvents. Eluted organic acids are detected photometrically by mixing the column effluent with a miscible solvent containing a suitable indicator. Samples require about 6 h for complete chromatography at present.
Automated Sequential Degradation of Ribonucleic Acids
Authors: Uziel Mayo , Starken J W , Eveleigh J W , Johnson W F
Published: January 2020

An instrument has been constructed that can automatically and selectively remove the terminal nucleotide residue from a ribonucleic acid. The instrument is designed to repeat the degradation cycle. This process involves two steps: (1) The base and sugar fragments are removed by the combined action of periodate and amine. (2) The phosphate residue, attached to the originally penultimate residue, is removed by enzymatic hydrolysis. Various techniques have been studied to establish the optimal methods for separating the residual polynucleotide chain from the various reagents and reaction products. In the most efficient and reproducible system, a membrane is used to separate the residual polynucleotide from the reaction products. The enzyme is bound in an active state to a plastic bead, so that simple filtration separates it from the dephosphorylated polynucleotide. All of the chemical and separation steps are quantitative (greater than 99% yield). The analyses are performed automatically by sampling the diffusate, and they are complete before the enzyme hydrolysis begins. The overall efficiency (number of cycles successfully completed) depends upon the stability of the instrument. We have performed up to six cycles with an average yield of 98%.
Rapid Liquid-Chromatographic Separation of Steroids on Columns Heavily Loaded with Stationary Phase
Authors: Karger Barry L , Berry Laverne V
Published: January 2020

Properties of heavily loaded columns are illustrated, especially as applied to steroid separation. By "heavily loaded" we mean that the column contains an amount of stationary phase such that the pores of the solid support are essentially filled. The solid support can be loaded with as much as 35-50% by weight of stationary liquid phase, depending on the pore volume and the activity of the solid support. Using heptane/dioxane/formamide, we studied several heavily loaded columns with different liquid loadings and solid support particles of various diameters. Porasil C (10-25 µm particle size) gave markedly improved speed and efficiency characteristics over Porasil A (44-53 µm). A separation efficiency as great as 2.5 effective plates per second was achieved with support material having the smaller particle diameter. Qualitative reasons for this good efficiency are discussed. Column efficiency was independent of quantity (from 1 µg to 1 mg) of injected steroid sample. Finally, applicability of heavily loaded columns to separation of steroids is illustrated. With stepwise pressure programming, 10 steroids can be separated in 35 min.
Ultraviolet-Absorbing Compounds in Urine from Patients with Hereditary Disorders of Purine and Pyrimidine Metabolism
Authors: Beardmore Thomas D , Kelley William N
Published: January 2020

A Mark II prototype uv analyzer was used to study urinary uv-absorbing compounds in eight patients with gout, one patient with partial deficiency of adenine phosphoribosyltransferase, three patients with the Lesch— Nyhan syndrome, two patients with hereditary orotic aciduria, and two obligate heterozygotes for orotic aciduria. All eight gouty subjects excreted abnormal amounts of one or more uv-absorbing compounds while on a strictly defined dietary and drug program. These included increased excretion of xanthine, pseudouridine, uracil, or orotidine. The excretion of uv-absorbing compounds in patients with well-defined inborn errors of purine and pyrimidine metabolism was consistent with the findings previously reported. The significance of these abnormalities is discussed and the importance of strictly controlled conditions is emphasized.
Effects of Irradiation or Traumatic Injuries on Propionate Metabolism in Rats
Authors: Henderson Thomas R , Jones Robert K
Published: January 2020

The rate of 14CO2 production in vivo by rats after injection with 10 µCi of 1-14C-propionate is useful in selecting uniform groups of animals for studies of experimental injuries and in investigating dose—response relationships in animals exposed to injury. The response appeared to be most sensitive to lung injury induced by air-blast, but was also sensitive to critical levels of irradiation or thermal exposure. Irradiation with 60Co γ-irradiation significantly depressed 14CO2 production, the degree and persistence being doserelated. Critical burn injuries resulted in decreased rates of 14CO2 production, which decreased as the clinical condition of animals deteriorated. Because the most significant decrease occurred within the first 30 min, measurement of the initial rate of 14C-propionate utilization was sufficient to detect altered metabolic states. High-resolution radioanalyses of urinary organic acids show the major ones excreted to be propionate and its immediate catabolites, methylmalonate and succinate, in both control animals and animals exposed to experimental injuries. These results suggest that propionate metabolism may be one of the sites in intermediary metabolism that is sensitive to alteration by experimental injuries and thus may be one of the more sensitive metabolic indicators.
Extra Lactate Dehydrogenase Isoenzyme Band in Serum of Patients with Severe Liver Disease
Authors: Lubrano T , Dietz A A , Rubinstein H M
Published: January 2020

In a study of lactate dehydrogenase isoenzyme patterns in the sera of patients with severe liver disease, who were primarily selected because of an abnormally high serum bilirubin, 42 of 76 patients had an additional band (LDH-T) between isoenzymes 4 and 5 on acrylamide gel. Thirty of the 42 patients died during followup, 24 within a month of recognition of the extra band.
Paper-Chromatographic Quantitation of 4-Hydroxy-3-methoxymandelic Acid (VMA) in Urine
Authors: Vahidi Ardeshir , Roberts Henry R , San Filippo Joseph , Sankar D V Siva
Published: January 2020

We describe a quantitative paper-chromatographic method for assaying 3-methoxy-4-hydroxymandelic acid (VMA) in urine. VMA is extracted from acidified urine into ethyl acetate, separated from interfering amine, acid, and alcoholic metabolites by paper chromatography, and reacted with diazotized p-nitroaniline. The colored derivative is eluted and spectrophotometrically analyzed. Recoveries of replicates of standard and sample solutions on the same chromatogram exceeded 95%.
Coulometric Titration of Blood Glutathione
Authors: Ladenson Jack H , Purdy William C
Published: January 2020

Conditions are described for coulometric titration of reduced glutathione with silver(I), in an ammoniacal medium. pH and buffer capacity of the medium are important variables. Metaphosphoric acid, 50 g/liter, is superior to metaphosphoric acid, 10 g/liter, or sulfosalicylic acid, 25 g/liter, for precipitating blood proteins. Results of the coulometric method are about the same as those obtained with spectrophotometric procedures in which alloxan or 5,5'-dithio-bis-(2-nitrobenzoic acid) is used.
Automated Immunochemical Procedures for Measurement of Immunoglobulins IgG, IgA, and IgM in Human Serum
Authors: Killingsworth L M , Savory John
Published: January 2020

Automated continuous-flow procedures have been developed for microdetermination of immunoglobulins IgG, IgA, and IgM in human serum. The three immunoglobulins are measured by reactions with specific commercial antiserum, and standardized by use of pooled human serum containing known concentrations of IgG, IgA, and IgM. Values determined for the immunoglobulins by the automated procedures correlate with values obtained by radial immunodiffusion. The precision of replicate determinations for the IgG, IgA, and IgM methods is 3.64, 5.11, and 6.00% (CV), respectively.
Plasma Calcium Assay, with Use of the Jellyfish Protein, Aequorin, as a Reagent
Authors: Izutsu K T , Felton S P
Published: January 2020

A previously proposed assay for plasma calcium, suitable for routine clinical measurements, has been investigated. The method is based on the calcium-sensitive luminescence of a jellyfish protein, aequorin. Advantages of this method are low cost, simplicity, and the suitability of most currently available fluorometers and spectrophotometers for the assay. Disadvantages are that aequorin may not be readily available, and that the assay apparently yields only the total and (with suitable sample preparation) the diffusible calcium concentrations.
Use of the Du Pont "Automatic Clinical Analyzer" in Direct Determination of Lactic Acid in Plasma Stabilized with Sodium Fluoride
Authors: Westgard James O , Lahmeyer Brenda L , Birnbaum Marvin L
Published: January 2020

We have studied the determination of lactic acid with the Du Pont ACA and the suitability of plasma as a sample. Blood collected in sodium fluoride/ potassium oxalate Vacutainers and separated in 15 min provided acceptably stable plasma. With a 40-µl sample of plasma, results are linearly related to concentration to 20 mmol/ liter. Standard deviations were 0.16-0.22 mmol/ liter for day-to-day precision. When lactate was added to 53 samples, an average of 99.11% was recovered analytically. Results for plasma lactate (y-axis) agreed with those on plasma filtrates by the Calbiochem "Rapid Lactate" method (n, 92; slope, 1.025; y intercept, -0.086 mmol/liter; standard error, 0.23 mmol/liter). Perchloric acid filtrates can also be analyzed, but fluoride-stabilized plasma is simpler to use.
Gas-Liquid Chromatographic Isolation, Identification, and Quantitation of Some Barbiturates, Glutethimide, and Diphenylhydantoin in Whole Blood
Authors: Cooper Rodney G , Greaves Mavis S , Owen Goronwy
Published: January 2020

An accurate method is described for the qualitative and quantitative determination of 11 barbiturates, glutethimide, and diphenylhydantoin in a single extract obtained from 1 ml of whole blood, which is extracted with ether at pH 2 and separately but simultaneously gas-liquid chromatographed on a selective (3% OV-17) and a nonselective (5% OV-1) column. Retention data are given. Results for barbiturate obtained by the Broughton [Biochem. J.63, 207 (1956)] spectrophotometric method and this gas-liquid chromatographic method are compared. Blood from more than 30 patients has been analyzed, and data are given to illustrate some of the findings.
Comparison of Rapid Clottable Fibrinogen Assays
Authors: Davey Frederick R , Carrington Constance E , Nelson Douglas A
Published: January 2020

Measurements of fibrinogen concentration by use of two rapid methods (clot-weight method and thrombin-turbidity method) were compared with the reference thrombin-coagulation method of Ratnoff and Menzie [J. Lab. Clin. Med. 37, 316 (1951)]. Both rapid methods gave results (in the high, middle, and low ranges) that correlated well with those of the thrombin-coagulation method. However, the thrombin-turbidity method was more precise, easier, and quicker than the clot-weight method.
Investigation of the Use of Calcein in the Ultramicro Fluorometric Determination of Calcium in Serum
Authors: Bandrowski James F , Benson Carl L
Published: January 2020

Calcium in serum is commonly determined fluorometrically with calcium-calcein as the fluorescent complex. A method is presented for analyzing calcein to determine the optimal concentration for both greatest linearity and greatest reproducibility. Serum calcium as determined with the "UNOPETTE" system is compared with results obtained by use of a Technicon SMA 12/60.
Significance of Increased Alkaline Phosphatase and Lactate Dehydrogenase Activities Coincident with Normal Serum Bilirubin
Authors: Betro M G
Published: January 2020

The diagnostic significance of a simultaneous increase in the activities in serum of alkaline phosphatase (ALP) and lactate dehydrogenase (LD) with normal serum bilirubin has been studied in 202 hospital patients. Of these cases, 28% were due to congestive heart failure or myocardial infarction, 25% to malignancy, and 16% to various hepatobiliary disorders. Fewer cases were due to bone fractures with large hematomas, pulmonary embolism, renal failure, or malabsorption syndrome. These biochemical changes in the patients with malignancies did not necessarily signify the presence of hepatic or bony metastases. Hypercalcemia occurred only in this group of patients, and was thus of considerable diagnostic importance. Neither the other tests performed with the SMA 12/60 or the ratios between LD and ALP gave diagnostically useful results.
Modified "Calcium Base Reagent" for Simultaneous Determination of Serum Calcium and Inorganic Phosphate with the "AutoAnalyzer"
Authors: Fischl J , Schwartz F
Published: January 2020

Replacement of the original "calcium base reagent" containing diethylamine with one containing triethanolamine and ammonia in the simultaneous calcium/phosphate method (Technicon method file N-26/a) gives a better calibration curve up to Ca concentrations of 150 mg/liter. In the original method the curve flattens above 100 mg/liter; thus in the proposed modification the reliability of the results are improved for samples from hypercalcemic cases.
Serum Alkaline Phosphatase: Total Activity and Isoenzyme Determinations Made by Use of the Centrifugal Fast Analyzer
Authors: Statland Bernard E , Nishi H Harold , Young D S
Published: January 2020

We present a kinetic method in which the centrifugal analyzer is used to determine total alkaline phosphatase activity and to measure the isoenzymes in bone, liver, and the L-phenylalanine-sensitive fraction (intestine, tumor, and placenta). Measurements were made at 30°C in diethanolamine buffer, with p-nitrophenylphosphate as substrate. The alkaline phosphatase isoenzymes were separated and measured by selective chemical inhibition with 10 mmol/liter L-phenylalanine and 3.3 mol urea per liter. Analyses were performed on sera of a group of healthy pediatric and young adult volunteers and, in addition, on sera from patients with clinically documented osteoblastic disorders and hepatobiliary diseases. The precision and accuracy of the centrifugal analyzer were evaluated, as was the suitability of the instrument for routine clinical laboratory use.
Possible Mechanisms for the Increase in Alkaline Phosphatase Activity of Lyophilized Control Material
Authors: Smith Alistair F , Fogg Barbara A
Published: January 2020

The increased alkaline phosphatase (EC 3.1.3.1) activity of reconstituted lyophilized control sera has recently been the focus of considerable interest because of its possible implications for quality-control procedures. We confirm that these reconstituted materials show a temperature-dependent increase in alkaline phosphatase activity, but could show no alteration in activity of fresh sera. The rate of increase in activity was unaffected by dialysis of the reconstituted material, and occurred more rapidly in dilute solutions. Studies with acrylamide gel electrophoresis and Sephadex G-200 gel filtration showed that, immediately after reconstitution, a high-molecular-weight alkaline phosphatase component predominated; during subsequent spontaneous activation this component decreased, and there was a concomitant increase in a low-molecular-weight alkaline phosphatase component. The results obtained when the reconstituted material was extracted with butanol suggest that the observed changes in alkaline phosphatase activity may be attributed to the breakdown of a complex between alkaline phosphatase and lipoprotein.
Immunochemical Quantitation of Prostatic Phosphatase
Authors: Milisauskas and Vita , Rose Noel R
Published: January 2020

A monkey antiserum to a fraction of human urine precipitated by concentrations of ammonium sulfate between 1.5 and 2.5 mol/liter was shown to contain antibodies specific for prostatic acid phosphatase. Using a modification of Laurell’s immunodiffusion method with a phosphatase stain, we devised a quantitative immunoassay for this enzyme.
Diagnostic Effectiveness of Electrophoresis and Specific Protein Assays, Evaluated by Discriminate Analysis
Authors: Werner Mario , Brooks Samuel H , Cohnen Georg
Published: January 2020

With use of the serum protein pattern as a model, we compared the "Diagnostic Effectiveness" of tests of different chemical specificity—i.e., the percentage classified correctly according to the clinical diagnosis. When results obtained from a selected population of subjects with selected diseases were evaluated by multivariate analysis, disease discrimination by paper electrophoresis, which resolves only chemically heterogeneous fractions, was similar to that of a battery of specific assays for individual proteins.
Gas-Chromatographic Determination of Total Estriol in Amniotic Fluid
Authors: Touchstone Joseph C , Murawec Taras , Bolognese Ronald J
Published: January 2020

A simple gas-chromatographic procedure is described for determination of total estriol in amniotic fluid. Before 20 weeks gestation the concentrations (<1 µg/100 ml) were not meaningful. After 20 weeks there was a gradual rise, followed by a rapid rise during the last weeks of pregnancy.
Separation and Identification of Neutral and Acidic Metabolites in Cerebrospinal Fluid
Authors: Waterbury L D , Pearce L A
Published: January 2020

We describe a method for obtaining profiles of neutral and acidic substances present in human cerebrospinal fluid (CSF) by gas—liquid chromatography. Metabolites extracted with ethyl acetate and ether are converted to methyl ester, trimethylsilyl ether derivatives. With this technique, acidic metabolites of brain amines, and neutral metabolites of dopamine and norepinephrine have been identified in human CSF. Some of these substances have not been reported previously in CSF. Extracted substances are identified on the basis of their methylene-unit values and mass spectral data. Potential use of this method in neurodiagnosis and in delineating drug-induced changes in CSF metabolites is discussed.
Intracellular Clinical Chemistry
Authors: Baron D N
Published: January 2020

The plasma compartment, on which almost all routine analyses in clinical chemistry are performed, occupies only a small part of the body, most of which consists of cells. For most components the intracellular and extracellular compartments have a different composition in health, and change differently in disease. The readily available cells are erythrocytes, and although these can be used for many purposes, including vitamin studies, they should not be used for studies of water and electrolytes. Muscle cells and leukocytes are the other available cells: they present different problems of isolation and methodology, but valid work has been done on their use for studies of water, electrolytes, and pH in health and disease. A recently developing study is the identification of inborn errors of metabolism by analysis of leukocytes and other cells. All cellular studies offer problems in that changes in one type of cell cannot necessarily be applied to changes in the cellular compartment of the body as a whole.
Simple Fluorometric Method for Estimating Practolol [1-(4-Aminophenoxy)-3-isopropylaminopropan-2-ol] in Blood and Urine
Authors: Bodem Gunter , Chidsey Charles A
Published: January 2020

A fluorometric method has been devised for determining practolol [1-(4-aminophenoxy)-3-isopropylaminopropan-2-ol], a new beta-adrenergic receptor antagonist, in blood and urine. The conjugate of deacetylated practolol with nitrosonaphthol is highly fluorescent in weak acid. The excitation wavelength used is 460 nm, the emission wavelength 550 nm.
Alkaline Phosphatase: Lability in Fresh and Frozen Human Serum and in Lyophilized Control Material
Authors: Massion Charles G , Frankenfeld Jean Kingsbury
Published: January 2020

On storage, the activity of alkaline phosphatase (AP) in human serum increases. This has been known, but largely ignored, for 40 years. Improved instrumentation makes this lability more obvious and more important because errors from other sources have been decreased. With a stabilized spectrophotometer we quantitated the effects of time and temperature on AP activity of human sera and of lyophilized "control" material. Activities of 10 fresh sera increased by an average of 0.9, 2.7, and 6.1% in 6, 24, and 96 h; that of pooled serum, frozen and thawed, increased about 1% per hour. For 22 lots of reconstituted lyophilized material the increase ranged from 3 to 22% in 6 h. Refrigeration greatly decreased, but room temperature restored, the rates of change. Freezing decreased the activity of some lots, and most had a smaller rate of increase. Generally, the lower the initial activity of a given lot, the greater was the rate of increase. The difference in rate of increase among materials from different sources varied widely. Delay in measurement of serum AP activity is not the only source of potentially serious error; time and temperature variations are also, when lyophilized materials are used.
Automated Sample-Reagent Loader for Use with the GeMSAEC Fast Analyzer
Authors: Burtis C A , Johnson W F , Mailen J C , Attrill J E
Published: January 2020

With a newly developed automated sample-reagent loader, for use with a GeMSAEC Fast Analyzer, a 15-place GeMSAEC transfer disk can be automatically loaded with reagent and samples in 3.25 min; manual loading methods required 15 min. The resulting precision and accuracy is equal to or better than that for manual methods of loading. Sample carryover of the system was decreased, and is about 1%.
Laboratory for Preparation of High-Purity Clinical Chemicals
Authors: Zief Morris , Nesher Alexander G
Published: January 2020

A laboratory is described for the preparation and analysis of high-purity clinical chemicals. The work area is designed to minimize contact of high-purity materials with the main source of contamination, the chemical operator. We discuss the use of a perforated, curved, anodized aluminum membrane that permits completely free access to the work area and describe the general construction of the laboratory. Dust counts under various conditions are reported, and techniques for eliminating contamination delineated.
Radioimmunoassay of Angiotensin I: Comparison of Two Renin Activity Methods and Use for Other Measurements of the Renin System
Authors: Katz Fred H , Smith Judith A
Published: January 2020

Standard curves for radioimmunoassay of angiotensin I vary with the amount of plasma or plasma extract present in the assay samples. Therefore results of all such analyses must be compared with standards processed precisely like the unknowns. Results of renin activity, assayed directly in plasma or plasma extracts, corresponded well, demonstrating the comparability of the two types of methods. We describe simplifications in measuring activity, substrate, and concentration of renin, and emphasize use of the optimum pH for determining action of the enzyme. In addition, we present evidence for the presence of angiotensin I in the circulation, especially after renin secretion is stimulated.
New Procedure for Purifying and Crystallizing Alkaline Phosphatase from Human Intestinal Mucosa
Authors: Narayanan Sheshadri , Appleton Harold D
Published: January 2020

A new procedure is described for extracting, purifying, and crystallizing alkaline phosphatase orthophosphoric monoester phosphohydrolase (EC 3.1.3.1) from human intestinal mucosa. Active enzyme, extracted with trichlorotrifluoroethane, is subsequently purified by chromatography on Sephadex G-200 and DEAE Sephadex. The acetone and ammonium sulfate precipitation steps that are part of the conventional butanol extraction and purification procedure are eliminated. Enzyme activity is concentrated at each stage of the purification procedure, yielding a preparation with a specific activity three times greater than that obtained with the conventional butanol procedure.