bluuebunny/crossref_metadata_2025 huggingface dataset:
Air-Cooled Extractors and Their Use in Determination of Cholesterol
Authors: Holmes Frederic E
Published: January 2020

For the purpose of determination of cholesterol in blood, serum, or other fluids of high cholesterol content, an extractor, previously described, has been devised which dries and extracts the sample on filter paper in one continuous operation with one solvent—chloroform. Moisture driven from the sample was collected above the refluxed solvent in a trap inserted between the water-cooled condenser and the sample. In order to avoid limiting the apparatus to location near a water outlet, and for greater ease and speed in handling the condensers, air cooling has since been substituted. A choice of several designs of trap is offered. Boiler-receiver tubes made to fit the Klett-Summerson photoelectric colorimeter provide for the extraction and the development and reading of the colors, all in the same tubes.

The method of extraction is given, and the errors due to esters of cholesterol and other substances are discussed.
An Evaluation of Technics for the Separation and Estimation of Plasma Fibrinogen
Authors: Goodwin Jesse F
Published: January 2020

A proposed heat precipitation and thrombin interaction technic for fibrinogen isolation has been compared with a sulfite fractionation technic. All three methods exhibit a high degree of correlation. Fibrinogen, which has been separated from plasma by these technics, may be quantitated by the colorimetric modified biuret and phenol-biuret reaction.

For direct measurement of fibrinogen, heat precipitation followed by ultraviolet spectrophotometry appears to be the technic of choice. The method of measurement at two different wave lengths does not appear to present any advantage over single wave length measurement at 240 and 220 mµ. Free hemoglobin in concentrations below 800 mg./100 ml. of plasma does not interfere with the sulfite fractionation technic but seriously interferes with the ultraviolet measurements in concentrations above 200 mg./100 ml. Bilirubin interferes with sulfite fractionation in concentrations above 24 mg./100 ml. but not with the heat precipitation technic for fibrinogen estimation. Lipids in excess above normal amounts interfere with both the sulfite fractionation and heat precipitation technics. Normal values for plasma fibrinogen from a variable age group using the sulfite fractionation technic and modified biuret end point have been determined.
Serum Glycoproteins and Proteins after Fractures
Authors: Hertzberg M , Oberman Z , Weissman S L , Herold H Z
Published: January 2020

Follow up of patients with fractures shows that there are alterations of the blood protein electrophoretic patterns and glycoprotein levels. The α1- and α2-globulin and glycoprotein levels are usually increased during the first 2 weeks and return to normal after this period. The blood albumin level is slightly reduced, while the globulin levels are increased and also return to normal after 2 weeks. The levels of the β- and γ-globulins usually stay unaltered, except when complications supervene.
Fluorometric Measurement of Creatine Kinase Activity
Authors: Sax Sylvan M , Moore John J
Published: January 2020

The amount of creatine liberated in the creatine kinase reaction is conveniently measured by formation of a fluophor with ninhydrin in strongly alkaline solution. The method is rapid and sensitive. The incubation conditions developed are more nearly optimal than those in previous methods.
Evaluation of Hydrolytic Products of 17-Ketosteroids by Means of Gas-Liquid Chromatography
Authors: Cawley L P , Musser B O , Faucette W , Beckloff S , Learned H
Published: January 2020

In the course of evaluating urinary 17-ketosteroid (17-KS) gas-liquid chromatographic patterns, a number of peaks with retention times shorter than that of 17-KS were constantly observed. This background material was found to be degradation products of 17-KS produced by HCI hydrolysis. A study with pure 17-KS as a mixture and as individual steroids was used to identify the steroids responsible for most of the 9 compounds with retention times less than etiocholanolone. Hydrolysis in ethyl acetate containing perchloric acid produced smaller amounts of degradation products than HCI-hydrolysis. Enzymatic hydrolysis appears to be the most acceptable system for preparation of the extracts from urine for this system of assay.
The Effect of Methenamine Mandelate (Mandelamine) on Determination of Urinary Estriol
Authors: Touchstone Joseph C , Stojkewycz Maria , Smith Kaighn
Published: January 2020

The administration of methenamine mandelate (Mandelamine) to pregnant women causes the levels of estriol in their urines to be unmeasurably low when acid hydrolysis is used. When enzyme hydrolysis replaces acid hydrolysis, normal estriol values are obtained. This result is attributed to the formaldehyde released by acid from hexamethylenetetramine, a constituent of the drug. The formaldehyde reacts with estriol to prevent its determination.
Blood Volume Error Detector
Authors: Boutwell Joseph H , Stewart George H
Published: January 2020

The addition of a simple transistor amplifier stage to an inexpensive gamma radiation detector has permitted its routine use in detecting small losses of radioactive iodinated serum albumin, thus increasing the reliability of routine blood volume measurements under clinical conditions.
Automated Determination of Acid Phosphatase
Authors: Klein Bernard , Auerbach Joseph , Morgenstern Stanley
Published: January 2020

A procedure is presented for the automated determination of acid phosphatase activity in biological materials from either plant or animal origin. The Technicon N-7 flow diagram has been simplified, and the reagents for the measurement of enzymatically produced phenolic substances have been modified without loss of range or sensitivity. Both phenylphosphate and α-naphthylphosphate, introduced by Babson et al. (2, 3) for serum acid phosphatase, may be used as substrates. The Emerson reaction (alkaline aminoantipyrine and ferricyanide) with α-naphthol forms a more stable and reproducible color than the coupled product with tetrazotized o-dianisidine (Babson). Supporting data for these modifications are included.
Electrophoretic Fractionation of Serum Glycoproteins on Cellulose Acetate
Authors: Kelsey R L , deGraffenried T P , Donaldson R C
Published: January 2020

In a procedure for the routine electrophoretic fractionation of serum glycoproteins on cellulose acetate, electrophoretic fractionation is followed by staining utilizing the periodic acid-Schiff reaction. The patterns are scanned with a recording densitometer and simultaneously quantitated with an attached integrator. For 100 healthy blood donors,the means and standard deviations were: albumin, 10.9±1.4; alpha1,18.6±1.9; alpha2, 29.6±2.3; beta, 21.6±2.0; and gamma, 19.3±1.9%, respectively.
A Simple Method for the Quantitative Determination of N-Acetyl-p-Aminophenol (APAP) in Urine
Authors: Welch Richard M , Conney A H
Published: January 2020

A simple method is described for the rapid quantitative analysis of N-acetyl-p-amino-phenol (APAP) in urine. APAP and its conjugates present in the urine following the ingestion of acetophenetidin, APAP or acetanilid, are hydrolyzed with acid to p-aminophenol. This compound is coupled with phenol in the presence of hypobromite to form an indophenol dye whose concentration is determined spectrophotometrically. Application of this method to a study of 3 human subjects treated with acetophenetidin is described.
Determination of Microgram Quantities of Inorganic Boron in Mammalian Specimens
Authors: Konikowski T , Farr Lee E
Published: January 2020

A method is presented for estimation of inorganic boron in mammalian tissues, blood, cerebrospinal fluid, and urine. The procedure is simple and rapid, qualifying it particularly to meet needs in clinical chemistry. The mammalian tissues are first enzymatically digested and extracted; then the deproteinized extract is allowed to react with quinalizarin in concentrated sulfuric acid. The intensity of the resultant color is read spectrophotometrically at 620 mµ. The boron concentration in the tissue analyzed is obtained from a standard reference graph for that tissue. The method is applicable to concentrations as low as I µg. of boron per gram of mammalian tissue or fluid.
Analog Computation of Electrophoresis Patterns
Authors: Lotito Lawrence A , Mckay Donald K , Seligson David
Published: January 2020

Instrumentation is described for the computation of stained paper electrophoresis patterns of serum proteins. The unit not only plots the dyed protein fractions, but with its electronic units, stores the individual integration voltages, scales the voltages to a percentage of the total, and plots the data on a bar graph. By including the total protein value obtained by chemical analysis, a second survey of the integrator voltages provides the concentrations of the protein fractions in grams per 100 ml. of serum.
Porphyrins and Chlorins from a Congenital Porphyria Patient
Authors: Chu T C , Chu Edith Ju-Hwa
Published: January 2020

Analysis of porphyrins from the urine, blood, and feces of a congenital porphyria patient showed copro- and uroporphyrins from the blood contained more than 95% of the Type I isomer, and those from stool and urine, about 90%. The intermediate hepta-, hexa- and pentacarboxylic porphyrins from the urine contained 70% or less of the Type I isomer. The results are discussed and compared with those in porphyria cutanea tarda and from congenitally porphyric cattle. A new tricarboxylic porphyrin, its methyl ester with a melting point of 165° and an absorption band at 627 mµ in chloroform, was isolated from the feces. A urinary chlorin (643 mµ) was separated and studied, and a possible structure of a heptacarboxylic chlorin is suggested by its formation from porphobilinogen and by other pertinent data. Three fecal chlorins (with absorption bands at 646, 660, and 668 mµ) were also isolated. Only the one with 646 mµ absorption is relatively stable.
An Improved Colorimetric Transaminase Assay
Authors: Babson Arthur L , Philips George E
Published: January 2020

The chromogenic reaction between a diazonium salt and oxalacetic acid produced by glutamic-oxalacetic transaminase has been completely stabilized by the addition of acid and a surface-active agent instead of water. This improvement markedly simplifies the procedure by allowing the samples to be read at any time.
Quantitation of Serum Hemoglobin-Binding Capacity Using Cellulose Acetate Membrane Electrophoresis
Authors: Valeri C R , Bond J C , Fowler K , Sobucki J
Published: January 2020

A method is described for the quantitation of serum hemoglobin-binding capacity (haptoglobin level) using cellulose acetate membrane electrophoresis. Electrophoresis is carried out for 90 mm. Eight membranes are dried, stained, and scanned within 45 mm. The reproducibility of this technic is within ± 10%.
A Method for the Rapid Hydrolysis of Urinary Glucuronoside Metabolites of Testosterone
Authors: Kent John R , Rawitch Allen B , Peacock Fredrick
Published: January 2020

β-glucuronidase hydrolysis of ethyl acetate-extracted glucuronoside metabolites of testosterone is more rapidly achieved than enzymatic hydrolysis of these conjugates in untreated urine. Less enzyme is required, provided the extracted conjugates are incubated under optimal conditions. Near-maximum hydrolysis required 24 hr. with the extracted conjugates and 72 hr. with untreated urine.
Operation of the Technicon Flame Photometer with Natural Gas Use in the Determination of Serum Lithium and the Semi-Micro Analysis of Serum Sodium and Potassium
Authors: Nevius Donald B , Lanchantin Gerard F
Published: January 2020

Natural gas was substituted for propane gas in the oxygen-fuel mixture supplying the Technicon AutoAnalyzer flame photometer. This was accomplished by the use of a 1/3-hp rotary pump and attached manifold, which compressed the gas from the city line and supplied it at a constant pressure to the burner module of the system. A method for the automatic analysis of serum Li was devised by using K as an internal standard and comparing the output of the Li-sensitive photo-cell with that of an attenuated K-sensitive cell. In addition, a simple procedure was incorporated into the routine determination of serum Na and K: samples of insufficient volume were diluted in a solution of known electrolyte concentration, which permitted their quantitation without changing the tubing manifold or other operating components of the system.
Determination of Serum Calcium by Means of Sodium Alizarinsulfonate
Authors: Connerty Harold V , Briggs Anglis R
Published: January 2020

A direct method is described for the determination of serum calcium, in which reaction with sodium alizarin sulfonate takes place under optimal conditions to produce a colored complex of calcium, the absorbance of which is read at 550 mµ. One variation in procedure, in which prior isolation of the calcium as the insoluble oxalate is made, is also described.
"True" Creatinine Chromogen Determination in Serum and Urine by Semi-automated Analysis
Authors: Polar E , Metcoff J
Published: January 2020

The Jaffè reaction, used to determine creatinine in urine and plasma or serum, gives a positive error in the latter because of the interference of noncreatinine. In man (particularly children) endogenous creatinine normally occurs at a relatively low concentration in serum (0.3-1.0 mg./100 ml.). The analytic error contributed by noncreatinine chromogens, therefore, may be considerable.

Of various manual methods to eliminate this none has been used with automated creatinine analyses, which generally measure total creatinine-like chromogen. In the present investigation a strong cation-exchange resin is used manually for rapidly adsorbing and desorbing "true" creatinine from plasma which is then analyzed by an automated method. A phosphate buffer (pH 12.4) is substituted for 5% (w/v) NaOH, dialysis eliminated, and the instrument manifold design is modified. Concentrations of "true" creatinine from 0.2-2.0 mg./100 ml. can be determined at a rate of 20 samples per hr. in serum or 40/hr. in urine, with a recovery of 98-101%.
Comparison of Carbonate and Uricase-Carbonate Methods for the Determination of Uric Acid in Serum
Authors: Caraway Wendell T , Marable Herman
Published: January 2020

A colorimetric carbonate procedure for the determination of uric acid has been modified to include incubation of serum with uricase to destroy uric acid. Residual nonurate chromogens are subtracted from total chromogens to obtain the concentration of "true" uric acid. Result obtained by the carbonate and the uricase-carbonate methods were in good agreement. The mean concentration of nonurate chromogens in serum is approximately 2% of the true uric acid values. Recovery of uric acid added to serum is essentially quantitative. Formaldehyde markedly inhibits uricase activity and interferes with recoveries. The uricase-carbonate method is applicable to hemolytic serum and to serums from patients with uremia or those receiving high doses of salicylate in which excess concentrations of nonurate chromogens may be encountered.
Serum Cholinesterase in Analbuminemia
Authors: Dietz A A , Rubinstein H M , Lubrano T
Published: January 2020

Serum cholinesterase activity was found to be normal in persons with analbuminemia. This finding disproves previous speculations that there is some intimate connection between the hepatic biosynthesis of albumin and serum cholinesterase.
Organochlorine Pesticides in Gallstones
Authors: Simmons J H , Tatton J O'G
Published: January 2020

A method is described for the determination of organochlorine pesticide residues in human gallstones. The difficulty caused by the presence of large amounts of cholesterol in the stones is overcome by an acetylation step in the "clean-up" procedure, and the method finishes with identification and determination of the individual pesticides by gas-liquid chromatography.

Results are given for 28 samples submitted by 2 hospitals, showing small amounts of dieldrin, p,p'-dichlorodiphenylethane (pp'-DDE), and benzene hexachloride (BHC) isomers to be commonly present in small amounts in gallstones. Some explanation for the presence of these residues in the stones is given.

A case of suspected poisoning by these compounds showed an unusually large amount of dieldrin in the patient's stones.
Amobarbital Metabolism in Man
Authors: Kamm Jerome J , Van Loon Edward J
Published: January 2020

A gas chromatographic method for the estimation of microgram quantities of hydroxy-amobarbital in urine is described. The method has been applied to a study of the metabolic fate of therapeutic doses of amobarbital (60 and 180 mg.) in man. We have found that 45% of an ingested dose of the drug is excreted in urine as hydroxy-amobarbital in 3 days and that small amounts of the metabolite are detectable for as long as 5 days following the ingestion of a single 180-mg. dose of amobarbital.
Determination of LDH Isoenzymes
Authors: Bergerman Julio
Published: January 2020

A method has been developed for the quantitation of LDH isoenzymes on cellulose acetate paper, taking advantage of the direct fluorometric procedures based on reduced nicotinamide adenine dinucleotide (NADH). The procedure is simple and the reagents relatively stable, allowing the test to become a routine procedure in clinical laboratories.
Determination of Nonfibrin Protein in Fibrin Clots by Use of I131-Labeled Protein Fractions
Authors: Green G Sheldon
Published: January 2020

The amount of nonfibrin proteins occluded within fibrin clots was investigated with specific radioiodinated human protein fractions. Vigorous washing of the clot followed by syneresis on absorbant paper removed all but small traces of albumin and alpha and gamma globulins. These fractions constituted approximately 6% of the total proteins in fibrin clots when fibrinogen concentrations were normal. The percentage of occluded protein increased as fibrinogen levels decreased. At fibrinogen concentrations of 48 mg./100 ml. plasma, albumin approached 20% of the total. Fibrinogen determinations which are based on the protein content, or dry weight, of the isolated clot are thus subject to systematic error which varies inversely with the fibrinogen concentration.
The Determination of Amino Acids in 0.1 ml. of Blood Plasma
Authors: McEvoy-Bowe E , Thevi S Sarojini
Published: January 2020

A method has been developed for the determination of the following amino acids in 0.1 ml. of blood plasma: alanine, arginine, glutamine, glycine, lysine, serine, taurine, threonine, and valine. A micro Sephadex G-25 column was used to separate the plasma proteins from the amino acids. The amino acid fraction, which is collected in 1 ml. of eluate, is then desalted in an electrolytic desalter, and lyophilized. The residue is dissolved in 0.2 ml. 0.1N HCI, and 50 µl. is applied to paper for 2-dimensional chro matography. The estimation of the amino acids is carried out by means of a photoelectric densitometry. The method incorporates a procedure for eliminating variations in paper density. The results obtained are in good agreement with those obtained by ion exchange procedures.
Use of the Berthelot Reaction in the Automated Analysis of Serum Urea Nitrogen
Authors: Wilcox Alan A , Carroll Wallace E , Sterling Rex E , Davis H A , Ware Arnold G
Published: January 2020

A method is presented for the automated determination of urea nitrogen using the Berthelot reaction for measuring the ammonia released by the enzymatic action of urease. The method compares favorably with the automated diacetyl monoxime method and employs less dangerous and less expensive reagents.
Studies in Difference Spectra of Cerebrospinal Fluid
Authors: Kreke Cornelius W , Barbella Nicholas G , Cupac Barbara , Dugan Diane
Published: January 2020

Cerebrospinal fluids were treated with acid and the extent of protein denaturation along with surface perturbations was followed spectrophotometrically (method of difference spectra). It was found that the fluid samples from patients suffering from a number of neurologic diseases differed considerably among themselves and from pure proteins. The spectrophotometric differences obtained by the addition of a high concentration of acid (pH 1.2, final) were found to be enhanced when the spectra of the fluids at graded acid levels were compared.

Cerebrospinal fluids could be divided into two groups based on their responses to smaller concentrations of acid (at pH levels of 7.0 and 4.0). Fluids from patients with multiple sclerosis were found in only one group.
Ultrasonic Effects on lsoenzymes
Authors: Dubbs Clyde A
Published: January 2020

Several significant effects of ultrasonic treatment on human serum cholinesterase and aminopeptidase isoenzymes and on other serum proteins have been found by starch gel electrophoresis. The selective activation of one cholinesterase isoenzyme is especially striking. These effects must be considered when ultrasonic treatment is used for the extraction of intracellular enzymes. When the effects are appreciated, ultrasonics should provide a valuable tool for isoenzyme research.
A Study of the Colorimetric Dinitrophenylhydrazine Method for the Determination of Serum Glutamic Oxalacetic Transaminase Activity
Authors: Annino J S
Published: January 2020

Study of the colorimetric transaminase method of Reitman and Frankel for the determination of serum glutamic oxalacetic transaminase activity revealed the following: (1) although maximum absorption occurs at 444 mµ, absorbance readings at 505 mµ gave satisfactory results; (2) color development is immediate and the color is stable for at least 1 hr.; (3) a pyruvate calibration standard may be used; (4) sample blanks are not usually necessary; (5) a reagent blank should accompany each group of analyses and should be used as a photometric reference; (6) the relationship between dilution and enzyme activity is linear; and (7) although the relationship between incubation time and activity is not exactly linear, a factor has been determined to permit the use of a 12-min. incubation period with samples showing high enzyme activity.
The Photometric Microdetermination of Serum Total Globulins with a Tryptophan Reaction: A Modified Procedure
Authors: Saifer Abraham , Marven Thelma
Published: January 2020

A previously described colorimetric method for determination of total serum globulins by means of a tryptophan reaction is applied to the determination of total globulins isolated from serum by precipitation with 2% trichloracetic acid in ethanol.
A Simplified Method for Butanol-Extractable Iodine and Butanol-Insoluble Iodine
Authors: Benotti Joseph , Pino Samuel
Published: January 2020

A simplified method is presented for the determination of butanol-extractable iodine(BEI). The results compare favorably with the original method as described by Man et al. Also available, as part of the procedure for BEI, is a direct chemical determination for butanol-insoluble iodine (Bll) from the same specimen of serum. Heretofore,nonbutanol-extractable iodine has been studied only by means of radioactivity. This fraction merits further investigation.
Enzyme Fractionation by Means of Large- Scale Continuous- Flow Electrophoresis
Authors: Winsten Seymour , Jackson Jeanne , Wolf Paula
Published: January 2020

Large- scale, microglass bead, continuous- flow electrophoresis was used to separateand collect protein fractions from a single serum sample. These fractions were assayed for a multiplicity of enzyme activities. Relatively good recovery was obtained with lactic acid dehydrogenase, leucine aminopeptidase, and phosphohexoseisomerase. Artifactually high recoveries were observed with aldotase and isocitric acid dehydrogenase. The increase observed in aldolase activity may be due to a pH effect.
The Specificity of the Nitromethane-Hyamine Procedure for the Determination of Nitrofurantoin in Urine
Authors: Conklin John D , Hollifield Richard D
Published: January 2020

Data show that the presence of certain other antimicrobials in urine does not interfere with the determination of nitrofurantoin by the nitromethane-Hyamine procedure.
Kinetic Aspects of Cyanmethemoglobin Formation from Carboxyhemoglobin
Authors: Rodkey F Lee
Published: January 2020

The conversion of carboxy hemoglobin (HbCO) to cyanmethemoglobin (MHbCN) by Drabkin's reagent has been shown to be considerably slower than is the same reaction with oxyhemoglobin(Hb02). Conversion of Hb02 to MHbCN is complete in 10 min. whereas total conversion of HbCO requires 90-120 min. This difference in reaction rate must be considered in the determination of total hemoglobin as MHbCN when the blood contains appreciable HbCO.
An Enzymatic Spectrophotometric Method for the Determination of Xanthine and Hypoxanthine
Authors: Klinenberg James R , Goldfinger Stephen , Bradley Kathryn H , Seegmiller J Edwin
Published: January 2020

A method for determining the total content of the oxypurines xanthine and hypoxanthine in urine is described which is technically simplified and has greater specificity than existing methods. This method is highly specific, reproducible, and accurate. It also allows an estimation of the present xanthine and hypoxanthine in the urine without performing any additional measurements. When applied to plasma, special concentrating procedures are required and the method is therefore less precise.
Measurement of Total Body Hemoglobin by Bloodless Technic
Authors: Katchman Bernard J , Murphy James P F , Offner Kenneth M , Fox Jerome C
Published: January 2020

The theory and methodology for the determination of total body hemoglobin by Sjostrand's closed breathing technic has been evaluated. The results show that it is possible to determine total body hemoglobin from the measurement of alveolar carbon monoxide concentrations. A system for closed breathing measurement was designed and assembled which permits continuous monitoring of alveolar carbon monoxide and oxygen. Improvements in this system are suggested such that total body hemoglobin may be read out directly, from the determination of alveolar carbon monoxide concentrations, by means of a sensitive infrared analyzer. Such measurements of total body hemoglobin have a high correlation coefficient with measurements of total body hemoglobin made by the Risa (radioiodinated serum albumin) blood volume technic.
A Method for the Determination of Extracellular Space with 3H Inulin
Authors: Addanki Somasundaram , Cahill F Dallas , Sotos Juan F
Published: January 2020

A method for the extraction and quantitation of 3H inulin from tissues is described. This method does not require either combustion technics or time-consuming acid extraction procedures. Inulin is as soluble in the liquid scintillation medium as it is in water. Therefore, hot-water tissue extracts without further treatment were employed to quantitate 3H inulin. Nearly 100% recovery was obtained when different 3H inulin internal standards were added either to water or to tissue homogenates. The values obtained with this method for the extracellular space of different tissues of the rat agree with those reported in the literature.
A Turbidimetric Method for the Determination of Pentachlorophenol in Urine
Authors: Comstock Eric G , Comstock Betsy S , Ellison Katherine
Published: January 2020

A turbidimetric determination of pentachiorophenol in urine is presented. The method is suitable for monitoring industrial exposure.
Rapid Fluorometric Assay for Plasma Warfarin
Authors: Corn Milton , Berberich Robert
Published: January 2020

Acetone alters the ultraviolet absorption characteristics of warfarin (3-(α-acetonylbenzyl)-4-hydroxycoumarin) and increases the intensity of fluorescent emission. Fluorescence of warfarin in acetone is markedly decreased by acidification. These phenomena provide the basis for a rapid, simple assay for plasma warfarin.
Hyperfibrinogenemia in Schizophrenia
Authors: Seal Ulysses S , Swaim William R , Eist Harold
Published: January 2020

The mean plasma fibrinogen concentrations in one group each of newly admitted and institutionalized male schizophrenic patients were found to be significantly increased (p < 0.001) above normal. The results could not be attributed to occult medical disease.
A Simplified Method for the Analysis of Ultracentrifuge Film Records of Low-Density Lipoproteins of Human Serum
Authors: de Lalla Oliver F , Tandy Robert K , Loeb Harold G
Published: January 2020

A convenient method has been devised for analyzing ultracentrifuge film records of human serum lipoproteins. It is based on a template that can be constructed by the investigator according to the operational factors peculiar to his ultracentrifuge system. The film patterns are projected and traced on the template, the boundary limits of each lipoprotein class are located by reference to the template grid, and the concentrations are determined by polar planimetry. Simple procedures are incorporated that correct without loss of accuracy for the effect of concentration on sedimentation rate and for the Ogston-Johnston effect. In a test of 56 samples of human serum, the results obtained with this procedure did not differ significantly (p = 0.2) from those obtained with the conventional complex calculations.
An Automated Alkaline Phosphatase Assay with Phenolphthalein Monophosphate as Substrate
Authors: Hviid Kirsten
Published: January 2020

The manual procedure of Babson et al. (1) for the determination of serum alkaline phosphatase has been automated. The assay is based on the colorimetric determination of phenolphthalein formed on hydrolysis of phenolphthalein monophosphate. The procedure utilizes 0.16 ml. of serum without dialysis. Blanks are required only for turbid sera. Results are compared with those obtained by the manual procedure, and data relating to sample interaction, precision, blank values, and normal values are presented.
Abbreviation of the Glucose Tolerance Test
Authors: Hainline Adrian , Keller Dan F
Published: January 2020

The glucose tolerance test for reasons of convenience, economy, and, patient comfort can and should be abbreviated to test lasting 2 hr. when used to screen patients for diabetes mellitus. Studies of the laboratory results obtained from glucose tolerance testing substantiate previous observations that the fasting blood sugar level is an inadequate measure of carbohydrate intolerance. Definitive information may be obtained from specimens of blood collected at 1 and 2 hr. following the administration of glucose or carbohydrate hydrolysate. Such an abbreviation with permit the glucose tolerance test to be applied to more patients. Individuals with positive response should be further tested under controlled conditions before a diagnosis is made on the basis of the tolerance testing.
Automated Potentiometric Determination of Inorganic Blood Constituents (Na+, K+, H+, CI )
Authors: Dahms H
Published: January 2020

A system containing specific electrodes for inorganic constituents (Na+, K+, H+, Cl-)in blood has been developed which is automated with respect to sampling, calibration, and data acquisition and processing. The hardware that was built for the system included glass capillary electrodes, silver capillary electrode, special reference electrode, rotary valve, thermostatting and electrically shielding container, and probe selector-amplifier. Suitable standard solutions for the automatic calibration cycle were formulated and have been compared against primary standards. The computer programs for processing the data are briefly described. Data on the performance of the system (precision, speed, volume of specimen) are given.
The Reitman-Frankel Colorimetric Transaminase Procedure in Suspected Myocardial Infarction
Authors: Crowley Leonard V
Published: January 2020

The Reitman-Frankel transaminase method is a useful procedure in the evaluation of suspected myocardial infarction. Analysis of data from patients with myocardial infarction admitted to a 500 bed general hospital over a 5 year period revealed that the colorimetric procedure provided a 94% correlation with myocardial infarction established by clinical and electrocardiographic criteria. There was complete correlation in fatal cases where diagnosis of myocardial infarction was established by autopsy. The diagnostic usefulness of the colorimetric procedure would not have been improved significantly in this series by establishing a more narrow range of normal.
Precision Estimates in Clinical Chemistry
Authors: Bowers G N , Kelley M L , McComb R B
Published: January 2020

The precision of replicate analyses for alkaline phosphataseactivity measured on a survey reference sample was extremely poor. The reference sample's enzyme itself became suspect and was demonstrated to be sensitive to alkaline denaturation-in sharp contrast to the stability of the alkaline phosphatasesfound in human serum. The stability and chemical reactivity of the phosphatases present in this reference sample and in pooled frozen human serum, as well as those found in 4 partially purified nonhuman preparations and 4 commercial serum control materials, were investigated with regard to heat and alkaline denaturation, electrophoretic migration, and inhibition by phosphate, EDTA, and L-pheflylalanine. It was concluded that criteria of stability and chemical reactivity, as well as more detailed information concerning the source of enzymes utilized in reference samples and control materials, are needed. On the basis of these studies, reliance on commercial serum enzyme control materials as an enzyme "standard" cannot be endorsed.
Automated Atomic Absorption Spectrophotometry
Authors: Klein Bernard , Kaufman James H , Oklander Morris
Published: January 2020

A simplified flow system is presented for the determination of calcium in urine and spinal fluid, by automated atomic absorption spectrophotometry (AAS). Analysis following the addition of calcium to urine or spinal fluid specimens showed a mean recovery of 103% and 99%, respectively. A comparison of results of analyses on unselected urine specimens by manual and automated AAS shows good agreement.
Glycerol Lubricant: Potential Source of Error in Commercially Prepared Blood Specimen Tubes
Authors: Baum David
Published: January 2020

Glycerol used to lubricate the rubber stoppers capping certain commercially prepared blood specimen tubes (Vacutainers*) is a source of error when glycerol determinations are performed on blood collected in these tubes. It is suggested that the lubricant utilized in commercial preparation of collection tubes be designated prominently on labels and that further use of glycerol as a lubricant be eliminated.
Studies of Sampling Times in a Continuous Flow Analytic System
Authors: Young D S , Montague R M , Snider R R
Published: January 2020

An optical measuring device with electrical timing unit was designed to identify the aspiration of inadequate volumes of samples into AutoAnalyzers. The device measures the duration of transit of solutions past a fixed point in the sample line. Considerable differences in transit times are found under normal operating conditions when standard Technicon components are used. The variation in transit times is greater between sampler modules than when the same module is used. Documentation of duration of sample aspiration in publications describing AutoAnalyzer methods would facilitate comparison of results between laboratories. A modification of the Technicon Model II sampler unit is described which markedly reduces the variation in sample aspiration.
Freezing as a Method of Preserving Blood Ammonia
Authors: Lowe William C
Published: January 2020

The influence of temperature on in-vitro generation of ammonia in whole blood was evaluated. It was found that when blood was placed in a freezer at -20 to -25° there was no significant rise of blood ammonia levels even after 8 days of storage. There was a gradual rise when blood was placed in a refrigerator with the temperature at about 4° and a more rapid rise at room temperature. The inhibition of ammonia production at a temperature below -20° facilitates the laboratory procedure when it is necessarily delayed.
A New Rapid Method for the Determination of Serum Lipase
Authors: Dirstine Philip H , Sobel Charles , Henry Richard J
Published: January 2020

A new method is described for the determination of serum lipase using olive oil as substrate, and photometric, copper soap analysis for the measurement of fatty acids formed. The great sensitivity of this technic for measurement of the fatty acids permits a 30-min. incubation time and the use of 0.1 ml. serum. The reaction is zero order for this time period. Other aspects of the enzyme kinetics were studied and the normal values determined.
A Simplified, Economic, Working "Computer-Assisted Laboratory Information System" (CALIS)
Authors: Cillo Anthony A , Schopp Richard A , Klionsky Bernard , Amenta Joseph S
Published: January 2020

An operational computer-assisted laboratory information system is presented. This system simplifies the clerical operations at the nursing station, in the accounting office, and in the laboratory. It permits utilization of shared computer facilities on an economic basis for the preparation of improved clinical reports and for more effective laboratory control, teaching, consultation, and administration. Computer transfer of the data to tape and a tape drive accessory will provide data retrieval.
A Micromethod for Determination of Lead in Blood
Authors: Berman Eleanor , Valavanis Voula , Dubin Alvin
Published: January 2020

A micromethod requiring a 250-µl. sample has been developed for the determination of lead in blood.
Blood Oxygen Capacity
Authors: Clauvel M , Schwartz K
Published: January 2020

During determination of the oxygen capacity of blood by the Van Slyke method (1), the following adaptations were made in order to reduce errors: (1) Blood was equilibrated with water-saturated air in a siliconized tonometer. (2) The determination of the oxygen content of the sample was carried out immediately after equilibration. (3) Triton was used instead of saponin in the ferricyanide reagent. (4) Special care was taken in the preparation and storage of the dithionite reagent, which should be prepared fresh daily and stored in the dark at 4°. The hemoglobin content and oxygen capacity, measured by the modified technic, were compared in a series of 36 samples of human blood.
Plasminogen Assay
Authors: Swaim William R
Published: January 2020

An indirect caseinolytic assay for plasminogen utilizing acid-treated plasma or serum and optimal concentrations of streptokinase is described. A linear response to increasing plasma or serum concentrations was observed. An acid-treated plasma or serum sample is preferable to euglobulin. The method is simple, precise, and reproducible.
Determination of Organic Iodine Compounds in Serum
Authors: Pileggi Vincent J , Kessler Gerald
Published: January 2020

Unidentified substances in acetic acid column eluates, obtained in the determination of serum thyroxine by column chromatography with the anion-exchange resin Dowex-1, prevented the direct determination of thyroxine by interference with the iodidecatalyzed ceric-arsenite reaction. Pretreatment of the eluates with Br2 or Cl2 eliminated the interference and permitted the direct assay of thyroxine by the ceric-arsenite system without incineration or wet digestion. Pretreatment with Br2 or Cl2 also significantly enhanced the catalytic activity of thyroxine, rendering its iodine nearly equivalent to inorganic iodide in the ceric-arsenite system. This nonincineration thyroxine assay is significantly more specific than methods that employ wet or dry ashing, because many organic iodine compounds used in diagnosis and therapy are not measured. A comparison of the nonincineration technic with the alkaline dry-ash method on 110 random serums revealed a mean difference of 0.13 µg./100 ml. (X = 4.5 µg./ 100 ml.), with the nonincineration technic yielding the higher result. This difference was found to be statistically significant (p< 0.001).
Fluorometric Measurement of Fecal Bile Acids
Authors: Forman Donald T , Phillips Charles , Eiseman Walter , Taylor C Bruce
Published: January 2020

A method is described for the fluorometric determination of fecal bile acids. The method combines solvent extraction and thin-layer chromatography (TLC) isolation technics with a fluorometric method for measuring total bile acids. Recoveries of individual bile acids added to feces averaged 107% with a standard deviation of ± 5.6%. Bile acid excretion in normal human subjects on a self-selected mixed diet ranged from 196 to 460 mg. total bile acids per 24 hr.
Plasminogen Levels in Schizophrenia
Authors: Seal Ulysses S , Swaim William R
Published: January 2020

Serum plasminogen levels were measured in 50 normal subjects and 82 schizophrenic patients. The levels of plasminogen were significantly elevated (p < 0.001) in the group of schizophrenic patients.
SYMPOSIUM ON URINARY CONSTITUENTS OF LOW MOLECULAR WEIGHT Session II
Authors: Guri Charles D , Cole Leonard J
Published: January 2020

Urinary deoxycytidine and other pyrimidines have been studied in rats after wholebody irradiation. Utilizing combined column and paper chromatography and colorimetric determination of the isolated deoxycytidine, significant elevations in the excretion of this compound were observed during the first 24 hr. after irradiation. An increased concentration of deoxycytidine in the plasma was also observed within 4 hr. after X-irradiation. Utilizing both anion- and cation-exchange chromatography, X-irradiation has been shown to produce an increase in several other pyrimidines, including derivatives of the bases cytosine, thymine, and uracil. While the data were suggestive of a radiation-induced generalized pyrimidinuria, urinary deoxycytidine and thymidine demonstrated remarkable elevation and were predominantly responsible for this phenomenon.
Low Specific Gravity Syndrome
Authors: Gillen H W , Pippinger C E
Published: January 2020

Data strongly suggest that the longer patients have been treated in New Castle State Hospital, the higher the probability that they will demonstrate the low specific gravity syndrome. It is believed that a probably unrecognized alteration in human water metabolism among institutionalized patients who have chronic, severe epilepsy and who have been administered anticonvulsant drugs for many years has been documented. The drugs most commonly used within this population are diphenylhydantoin and phenobarbital. Each compound is reported to affect (albeit oppositely) the release of ADH, and both affect cellular enzyme systems related to water and/or electrolyte metabolism.
A New Method for the Microdetermination of Free and Total Nonprotein-bound Tryptophan in Plasma
Authors: Rio María Esther , Sanahuja Juan Claudio
Published: January 2020

A new technic for the determination of tryptophan in plasma, based on the tryptophan-dimethylaminobenzaldehyde reaction, is described. It provides a method for the determination of as little as 20 µg. of tryptophan and also permits the determination of bound tryptophan in nonprecipitable peptides, using 10% perchloric acid as the deproteinizing agent.
Application of Thin-Layer Chromatographic Zonal 14C-Profile Scans to the Analysis of Urinary Constituents Derived from Lipids
Authors: Snyder Fred , Cress Edgar A
Published: January 2020

Thin-layer chromatography (TLC) has been a useful tool in the analysis of numerous urinary constituents; as in most applications of adsorption TLC, it is best used in conjunction with other chromatographic processes. The application of TLC to the resolution of polar urinary products derived from lipids is shown for the metabolism of a 14C-labeled fatty acid and a 14C-labeled glyceryl thioether. An automatic system, including fraction collection of adsorbent, pipetting, data transmission, and computer calculations, was used to obtain the TLC zonal 14C profiles.
Optimum Reaction Conditions for Human Lactate Dehydrogenase Isoenzymes as They Affect Total Lactate Dehydrogenase Activity
Authors: Gay Royal J , McComb Robert B , Bowers George N
Published: January 2020

Optimum reaction conditions at 30° ± 0.5° for two continuous spectrophotometric assay procedures, lactate to pyruvate (L → P) and pyruvate to lactate (P → L), were determined with respect to pH at 30° (pH30) substrate concentration, and coenzyme concentration for the human LDH isoenzymes.

For the P → L procedure, broad pH30 optima were within the range of 7.20-7.40 for all the LDH isoenzymes. The coenzyme optima were identical for all of the isoenzymes tested at a reduced NAD concentration of 1.5 x 10-4 M. Pyruvate substrate optima ranged from 7.5 x 10-4 M for LDH1 to 1.7 x 10-3 M for LDH5 at pH30 7.30.

For the L → P procedure, the pH30 optima were within the range of 8.30-8.88 for the LDH5 through LDH1 isoenzymes, respectively. Optimum activity was obtained at a NAD concentration of 6.0 x 10-3 M and remained constant at least to 1.8 x 10-2 M for each of the isoenzymes tested. L-Lactate substrate optima ranged from 4.0 x 10-2 M for LDH1 to at least 7.2 x 10-2 M for LDH5.

From the isoenzyme studies, the degree of variation possibly involved in either method due to variations in isoenzyme distribution was calculated for total LDH samples. These calculations showed that both methods, P → L and L → P, were essentially equivalent. This equivalency was verified by a comparative study of the two methods on human serum samples.
An Automated Method for the Recovery of Urinary Nitrogen in Nitrogen Balance Studies
Authors: Peaston M John T , Wilson Sandra , Pemberton Judith
Published: January 2020

A method previously described for the total automation of nitrogen measurements from solid biologic material has been adapted for automating nitrogen recovery from urine following micro-Kjeldahl digestion. Standard solutions gave reproducible curves which were linear between the limits of 25 and 100 mg. of N2 ped liter. Comparative studies with the Markham (1) procedure revealed mean nitrogen recoveries for the automated method of 106%. The cause of the 6% difference remains unexplained, but cannot be attributed to low recovery by the Markham method. Application of a "correction factor" of 6% to the measurements by the automated method gave recoveries for urinary nitrogen almost identical with those obtained by the Markham method.

Time studies were compared on the two methods. When the number of urine samples to be analyzed exceeded 14 per day, the automated method was time-saving, reliable, and convenient. It is suggested that the method described should replace the Markham procedure in central hospital laboratories or regional metabolic units in which more than 14 urinary nitrogen measurements are made daily.
Discontinuous Electrophoresis on Polyacrylamide Gel Slab
Authors: Abadi D M
Published: January 2020

An apparatus for discontinuous electrophoresis on a slab of polyacrylamide gel is described. It affords resolution of serum protein as distinct as that with electrophoresis on a column of gel, but with considerable simplification in technic.
A Simple Method for the Preparation of Agarose
Authors: Barteling S J
Published: January 2020

Agar was purified by adsorption of the agaropectin from a hot agar solution with an insoluble adsorbent. The best results were obtained with aluminum hydroxide gel, especially when the agar was prewashed with an EDTA solution. The product obtained has a low sulfur content and has very good electro-endosmotic properties.