bluuebunny/crossref_metadata_2025 huggingface dataset:
Practical Procedure for Estimation of Corticosterone or Hydrocortisone
Authors: Silber Robert H , Busch Robert D , Oslapas Raymond
Published: January 2020

A simplified fluorometric procedure for corticosterone or hydrocortisone has been described. In spite of certain specificity limitations, it has practical applications for the estimation of these steroids in samples that are small in volume or low in concentration, or in studies that are designed primarily to demonstrate increases or decreases in adrenocortical hormones in plasma or adrenals without requiring absolute specificity. For rat, human, monkey, or guinea pig plasma, 0.5 ml. suffices for an analysis. One rat adrenal or a fraction of a guinea pig adrenal usually contains enough steroid for a single determination.

A procedure also has been described which can be applied to rat plasma to correct for interfering fluorescent material.
Determination of Lipoproteins by Paper Electrophoresis
Authors: Moinat Pierre , Appel Walter , Tuller Elizabeth F
Published: January 2020

A reproducible technic is presented for the staining of lipoproteins on paper. This method gives a greater total uptake of dye than previously described procedures, especially by the α-lipoproteins. The staining is accomplished with a solution of Sudan Black B in a mixture of methyl and isopropyl alcohols and the excess dye is removed by wash solution of 30% isopropanol.
Colorimetric Method for the Quantitative Determination of Plasma Catalase Activity
Authors: Dobkin Gerald B , Glantz Morton D
Published: January 2020

A colorimetric method for the determination of plasma catalase activity has been presented.

The assay is based on the reaction of undecomposed hydrogen peroxide with ferricyanide and ferric gum ghatti to give a Prussian Blue color.

The plasma catalase activity of a group of normal individuals has been determined.
A Comparative Study of Qualitative Tests for Ketones in Urine and Serum
Authors: Free Helen M , Smeby Robert R , Cook Marion H , Free Alfred H
Published: January 2020

Results are presented of a comparative study of several methods for detection of ketone bodies in urine involving nearly 10,000 tests on urines containing no ketones, naturally occurring ketones, and added acetoacetate. Acetest (a tablet nitroprusside test) and Ketostix (a strip nitroprusside test) are more specific and accurate, and have the proper sensitivity in comparison with test tube Rothera nitroprusside modifications or the ferric chloride test. Both the tablet and strip are also satisfactory for detection of ketones and serum or plasma. The tablet test may be used with whole blood for detection of ketonemia.
Assay of Thiamine in Biologic Fluids
Authors: Baker Herman , Pasher I , Frank O , Hutner S H , Aaronson S , Sobotka Harry
Published: January 2020

A method based on the protozoan Ochromonas malhamensis has been developed for assaying thiamine in biologic fluids. It is sensitive, specific and reproducible. Results by this method agree well with other less convenient methods of thiamine assay.
Automatic Titration of Calcium or Magnesium in Blood Serum
Authors: Malmstadt H V , Hadjiioannou T P
Published: January 2020

Direct automatic derivative spectrophotometric EDTA titration procedures for Ca and Mg in blood serum are described. Calcium is automatically titrated in the Sargent-Malmstadt "Spectro" titrator at pH 13 using Calcon as indicator. The results obtained by the automatic method are of the same degree of accuracy and reproducibility as those obtained by the classic permanganate titration of precipitated calcium oxalate. Total Ca and Mg can be titrated automatically at pH 10 with Eriochrome Black T as indicator, and magnesium is calculated by difference between total Ca and Mg and Ca only. The average automatic titration time for each Ca determination is about 10 seconds and about 15 seconds for total Ca and Mg. The total time for the complete procedure for each Ca or Mg determination is about 5 minutes.
Adaptation of an Alkaline Phosphatase Method for Automatic Colorimetric Analysis
Authors: Marsh Walton H , Fingerhut Benjamin , Kirsch Elaine
Published: January 2020

The alkaline phosphatase method of Kind and King was adapted to an automated recording colorimeter. The precision of the automated method (1 standard deviation as per cent of the mean value) was ±1.7 and for the manual method ±3.6 per cent. The color produced was proportional to the enzyme concentration by both methods, and recoveries of added phenol were satisfactory. In more than 150 serum specimens surveyed for enzyme activity, over 95 per cent of the results (2 standard deviations) of the 2 methods in the range 3.4-129 agree to within ±2.8 King-Armstrong units/1OO ml.
A Modification of the Spectrophotometric Determination of Carbon Monoxide in Blood Enabling Direct Determination of Per Cent Hemoglobin Saturation
Authors: Berninger Hans , Smith Roger
Published: January 2020

A modification of the spectrophotometric method for the determination of carbon monoxide in blood has been presented that enables direct determination of per cent hemoglobin saturation with an overall experimental error of 3 per cent.
The Determination of Inulin in Blood and in Urine by Means of Vanillin in Acid Medium
Authors: Levine Victor E , Becker William W
Published: January 2020

Vanillin in acid medium serves as a reagent for a simple, rapid, convenient method for the quantitative determination of inulin in blood and in urine.
Studies on the Serum Proteins
Authors: Sunderman F William , Sunderman F William
Published: January 2020

Human serum protein fractions were separated by continuous-flow electrophoresis and purified by dialysis, lipid extraction, lyophilization, and drying to constant weight. Increasing amounts of each of the protein fractions were applied to strips of filter paper. One set of strips was stained with amido black 10B dye, and another set with bromphenol blue. The dye-binding properties of the protein fractions were evaluated by (1) the Grassmann-Hannig and (2) Spinco tech nics of direct photometry, and (3) by elution procedures.

The calibration charts indicated that dye-binding is not a strictly linear function of protein concentration. This deviation is especially marked in the range from 0 to 40 µg. of protein. Deviation from the Beer-Lambert law with small quantities of protein leads to artifactitious augmentation in the estimation of proteins present in serum in low concentration, such as the alpha globulins.

In the range from 40 to 80 µg. of protein, with the three methods for quantitation, the affinities of alpha, beta, and gamma globulin for amido black averaged 80, 71, and 82 per cent, respectively, of that of albumin. Under comparable conditions, the affinities of alpha, beta, and gamma globulins for bromphenol blue averaged 64, 58, and 60 per cent, respectively. On the basis of these findings, amido black 10B appears to have a theoretical superiority over bromphenol blue for use in quantitative estimations of serum protein fractions by paper electrophoresis.
An Improved Test for Phenylketonuria
Authors: Rupe Chauncey O , Free Alfred H
Published: January 2020

A simple dip-and-read strip test for detection of phenylketonuria is described. This test contains ferric and magnesium ions and an acid buffer. It is called PHENISTIX. When the strip is moistened with urine it gives a gray to blue color with samples which contain phenylpyruvic acid, the intensity being proportional to the concentration of this constituent. A color chart provides for standardization of results and reproducible reports. Comparison of the performance of the test with conventional laboratory procedures has been carried out on over 1900 samples as tests on unknowns. The new test is reliable for the recognition of phenylketonuria and has some advantages over conventional laboratory procedures.
Concentration of Hyaluronic Acid in Synovial Fluid
Authors: Decker Barry , McGuckin Warren F , McKenzie Bernard F , Slocumb Charles H
Published: January 2020

1. The concentration of hyaluronic acid in synovial fluid was determined by a modification of the Dische carbazole method for the determination of uronic acids.

2. The results of this determination in 80 specimens of normal and abnormal synovial fluid confirmed values reported by other methods.

3. An inverse relationship between the hyaluronic acid in the synovial fluid and the degree of synovitis was suggested.
Studies on the Use of the van den Bergh Reagent for Determination of Serum Bilirubin
Authors: Meites Samuel , Hogg Cecelia K
Published: January 2020

1. By increasing the concentration of hydrochloric acid, sulfanilic acid, and sodium nitrite in the van den Bergh reagent used for determining total serum bilirubin it is possible to increase the absorbance of azobilirubin and to accelerate its reaction time to less than 10 minutes. A modified reagent is proposed for the Malloy and Evelyn procedure.

2. The effects of temperature, urea, and protein on the coupling of serum bilirubin are discussed.

3. Hemolysis seriously affects the coupling of bilirubin. The decrease in azobilirubin production appears to vary directly with the amount of hemolysis. When the amount of hemolysis is constant, the decrease in azobilirubin production appears to vary inversely with the bilirubin concentration. The interfering effect of hemoglobin is unexplained.
Spectrophotometric Studies of the Zimmermann Reaction
Authors: Friedman Howard S
Published: January 2020

An analysis of the optimal conditions of ethanol, alkali, and DHIA concentrations, and of time and temperature for the Zimmermann reaction have been presented, as well as two procedures for the hydrolysis, extraction, and determination of 17-ketosteroids in crude urine extracts.

A new modification of the Zimmermann reaction, using alkali in 80% ethanol, has been presented, showing the advantages and disadvantages over the Callow and Holthorff-Koch procedures.
A Note on the Determination and Identification of Cyanide in Biologic Materials
Authors: Tompsett S L
Published: January 2020

A procedure is described for the determination of cyanide in biologic fluids. Distinction can be made between simple cyanides, ferrocyanides and ferricyanides, nitroprussides, and cyanogenetic substances, such as amygdalin. Traces of cyanogenetic substances resembling amygdalin could be detected in normal urine. Other types of cyanide-like material could not be detected.
Procedures for Testing Urine Specimens Dried on Filter Paper
Authors: Berry Helen K
Published: January 2020

Procedures have been described for testing for phenylpyruvic acid, sugars, protein, and chondroitin sulfuric acid in urine dried on filter paper. Additional paper chromatographic methods for identification of phenylalanine, -hydroxyphenylacetic acid, glucose, and galactose have been described.
A Simple Method for the Determination of Blood Urea Nitrogen, with Special Reference to Automatic Colorimetric Analysis
Authors: Richter Helmut J , Lapointe Yvette S
Published: January 2020

The accepted automatic procedure for the determination of blood urea nitrogen has been developed into a "Manual" method, useful to users and nonusers of the instrument. This procedure is also very suitable for the determination of urea nitrogen in small specimens.
A Rapid Method for the Estimation of Urinary 17-Ketosteroids
Authors: Rappaport F , Fischl J , Pinto N
Published: January 2020

A rapid method for the estimation of urinary 17-ketosteroids, based on the Zimmerman reaction, is presented. The color complex due to ketosteroids is selectively extracted with chloroform. Turbidity of chloroform extract is avoided by the addition of polyethyleneglycol.
Effect of Disease States on the Ribonuclease Concentration of Body Fluids
Authors: Levy Arthur L , Rottino Antonio
Published: January 2020

A method for determining ribonuclease activity in amounts as low as 0.001 µg. in various body fluids is described.

In a number of pathologic conditions the level of RNase in the serum was found to be elevated; only rarely did a low value occur. The most significant change was found in patients with cirrhosis and leukemia, 60-70 per cent having high levels in contrast with 30 per cent of patients with carcinoma and Hodgkin's disease.

It was found that human urine usually contains larger amounts of RNase than blood serum, and that it may he a good source of the purified enzyme.
Nitrogen Balance Studies on Patients Infused with Protein Hydrolysate Containing Varying Amounts of Glucose
Authors: McNair Ruth Davis
Published: January 2020

Fifty-two postoperative adult patients were given varying amounts of intravenous glucose simultaneously with a constant quantity of protein hydrolysate and a constant caloric intake. The glucose concentration in the hydrolysate varied from 0-25 per cent. There was a marked increase in nitrogen retention in all the groups receiving glucose with the protein hydrolysate as compared to the group receiving no glucose with the protein hydrolysate. The nitrogen retention in patients receiving 1.25% glucose in the hydrolysate was as satisfactory as that obtained using 7.5% glucose. Dividing the protein-glucose mixture into morning and afternoon infusions appears to be of some benefit in increasing nitrogen retention.
Notes on Methemoglobin Determination
Authors: Leahy Thomas , Smith Roger
Published: January 2020

The Evelyn-Malloy procedure for the determination of methemoglobin in blood has been modified for use with a Coleman Jr. spectrophotometer by using a lower dilution of blood to reduce the effective instrument error from a possible 10 per cent to a possible 3 per cent.

The method has been further modified to give results directly as the per cent methemoglobin of the total blood pigment.

The normal range for this determination appears to be up to 2 per cent of the total pigment present as methemoglobin.

A statistically significant difference was observed between the means of the methemoglobin percentages of a normal group and a group of persons whose occupation placed them in frequent contact with petroleum fuels.
Seromucoid Determination: Variables and Modifications
Authors: Asher T M , Cooper G R
Published: January 2020

The technic of Winzler (1) for the determination of seromucoid has been studied to measure its reproducibility and the effect of certain environmental factors.

Values obtained are fairly reproducible (a difference of 45 mg./l00 ml. BSAP between two specimens indicates a significant difference at the P = 0.05 level).

Variables such as temperature, freezing and thawing, speed of addition of perchloric acid, and total protein content of serum have no practical influence on the final SM values.

A modification in technic involving determinations on three different dilutions of a specimen gives differences greater than those found with the standard procedure for sera from patients with an inflammatory condition.
Uptake of Radiosulfur During the Healing of Surgical Wounds
Authors: Williamson Martin B , Haley Harold B
Published: January 2020

The feasibility of using the deposition of S35 in wounds as a measure of the rate of healing was investigated by administering isotopically labeled methionine, cystine, or sulfate to surgical patients. It was found that the level of S35 measurable at the surface of the wounds was higher when either methionine-S35 or cystine-S35 was given after wounding than when given before. More S35 was incorporated into the wound tissue when methionine was the source of the isotope than when labeled cystine supplied the S35. About 4-7 times as much S35 was detectable in the regenerating wound tissue within a few days after wounding, compared to S35 detectable in unaltered skin. Only a relatively small amount of sulfate-S35 was taken up by healing wound tissue. These results were obtained by the use of a technic which made it possible to measure repetitively, over a long period, the activity at the surface of the same sample of wound tissue.
Paper Electrophoretic Studies of Glycoproteins in Rheumatic Fever
Authors: Gorczyca Leonard R , Lazaroni J A , Maier E C
Published: January 2020

Studies of serum glycoproteins by paper electrophoresis in rheumatic fever showed the following: Total glycoproteins were generally increased in concentration, the alpha-2 glycoprotein fraction showed moderate to marked increases in value, and alpha-1 and beta glycoprotein components generally showed moderately decreased concentrations.
Toxicologic Studies on Hydrocarbons. VI. A Colorimetric Method for the Determination of Kerosine in Blood
Authors: Gerarde Horace W , Skiba Paul
Published: January 2020

A photoelectric colorimetric method is described for the quantitative determination of kerosine in blood. The procedure involves hemolysis of 5 ml. of the sample followed by extraction of the kerosine with carbon tetrachloride. The extract is reacted with a formaldehyde- sulfuric acid reagent to produce a characteristic color. The intensity of this color is measured photometrically, and the concentration of kerosine is determined by reference to a previously prepared calibration curve. Concentrations as low as 10 ppm can be conveniently determined.
Triple-Test Strip for Urinary Glucose, Protein, and pH
Authors: Free Helen M , Collins Galen F , Free Alfred H
Published: January 2020

A triple-test strip for the simultaneous estimation of protein, glucose, and pH in urine with one simple dip-and-read operation is described. The three results can be obtained in little more than 10 seconds' time. Each of the three tests is a colorimetric reaction, and each is accompanied by a color chart for standardized results. A total of 12,674 results obtained in blind testing by experienced and inexperienced operators indicates that all three tests give accurate, reliable performance, as compared with other laboratory methods.
Direct Spectrophotometry of Total Serum Bilirubin in the Newborn
Authors: Meites Samuel , Hogg Cecelia K
Published: January 2020

A simple, rapid direct spectrophotometric method for the determination of total serum bilirubin on a micro basis, with a 1:21 dilution of serum in phosphate buffer, is presented for use with the Junior Coleman spectrophotometer. The formula, mg./100 ml. bilirubin = 50 A455 - 119 A575, is applied, where A represents the absorbancy at the wave length specified. The method for obtaining this or a similar equation is presented.

The spectrophotometric method, when applied to sera obtained from newborns, gives apparently reliable results in the presence or absence of hemolysis. An evaluation of the method and its limitations is presented.
Fluorimetric Determination of Creatine
Authors: Conn Rex B
Published: January 2020

A new fluorimetric method for determining creatine in serum, blood, and urine is described. The method is based upon the coupling of guanidine compounds with ninhydrin in alkaline solution to produce highly fluorescent products. In degree of sensitivity and simplicity the method possesses several advantages over currently used colorimetric methods, and creatine can be determined in concentrations as low as 1.0 X 10-7M. The serum creatine concentration was found to be 0.41 mg.% in normal adult males, who excrete only small amounts of creatine in the urine.
Further Modification of Flame Photometer
Authors: Raymond Samuel
Published: January 2020

Mechanical and electrical modifications of the Baird flame photometer are described that increase ease of setting, improve the precision of response, and permit both sodium and potassium to be determined without resetting zero or sensitivity controls.
The Polarographic Determination of Selenium in Urine
Authors: Faulkner Albert G , Knoblock Edward C , Purdy William C
Published: January 2020

Polarographic data are presented for the reduction of selenite ion in 3M sulfuric acid, 1M potassium chloride, and 1M ammonia-ammonium chloride. In these first two media two waves are obtained corresponding to the diffusion-controlled reduction of selenite ion to selenium amalgam and the adsorption of selenite ion on the mercury drop, respectively. One wave is obtained in ammonia-ammonium chloride corresponding to the reduction of selenite to selenide ion.

Selenium has been determined in urine over a concentration range of 0.0063 to 0.175 mM. (0.5 to 14 µg./ml., in a 10-ml. sample) with an average error of 2 percent. The effects of the time and method of storage on the loss of selenium by urine have been investigated. Although selenium is lost by urine under all methods investigated, storage in a deep freeze results in greater sample stability. It was also found that this loss could be prevented if the urine was made 1 molar to nitric acid.
Direct Determination and Binding Capacity of Serum Iron
Authors: Levy Arthur L , Vitacca Patricia
Published: January 2020

A modified direct procedure is described for measuring serum iron (SI) levels and serum unsaturated iron-binding capacities (UIBC). Protein digestion or precipitation, as well as extraction of the color of the iron complex are eliminated.

The protein-bound iron is dissociated at acid pH, reacted with terpyridine in the ferrous state, and the optical density is read at 552 mµ. The UIBC is measured by incubating the serum at alkaline pH with a known excess of iron. Only the unbound excess reacts with terpyridine, and the UIBC is obtained by difference. The mean normal SI level found was 98.0 µg./100 ml. with a range of 44-155; mean UIBC was 243, with a range of 150-336; mean total IBC was 344, with a range of 251-437. Seven other investigators report higher mean SI levels, varying from 110 to 173; UIBC values are in better agreement.

SI levels as low as 8 µg./100 ml. in anemia were measured.

The desirability of carrying out both determinations is indicated by the fact that 18 per cent of patients had normal SI levels, but abnormal UIBC.

The amount of iron bound to conalbumin, the iron-binding protein from egg white used as a control for the UIBC determination, agreed with that determined by other investigators.
Suggested ModiFications of the Micro Determination of Triglycerides
Authors: Van Handel E
Published: January 2020

In the procedure of Van Handel and Zilversmit (1), triglycerides are measured by assay of glycerol, after removal of phospholipids. Some modifications of this method are given. Zeolite is ground to 80 mesh (2); the unsaponified values are replaced by a simple reagent blank; oils are purified before being used as standards. Eight separate extractions from a single serum specimen, assayed in quadruplicate, yielded a value of 1.01 mg./ml. with a standard deviation of 0.028 mg./ml. for the 32 determinations.
The Identification of Barbiturates by Paper Chromatography
Authors: Fischl J , Segal Sara
Published: January 2020

A method for the chromatographic identification of barbiturates in three different solvent systems is presented. The chromatograms are sprayed with a reagent containing salicylate, which provides an internal screen for the visualization of the barbiturates under ultra-violet light.

The assembly of a simple, inexpensive chromatographic set and detailed technical procedure are described.
Ultramicro- and Micro-Determination of Chloride by Argentimetric Titration with the Indicator Dichiorofluorescein
Authors: Baumann Mary L , Hatmaker Alberta L
Published: January 2020

A reliable ultramicro modification of the Franco and Klein (1) determination for chloride, using 20 µl. of plasma, is described. A second procedure, requiring 0.2 ml. of plasma and substituting a titrating syringe for a buret, is suggested as a fast and adequate substitute in the absence of either extensive laboratory facilities or trained personnel. Data on reproducibility and recovery, and a comparison with another chloride procedure are presented. The limitations of the procedures are discussed.
A Rapid Semimicromethod for the Determination of Phosphorus and Barium in Biologic Preparations
Authors: Borchardt Paul , Dindial Winston , Mettenleiter Michael
Published: January 2020

The determination of phosphorus and barium is made on acid digests of tissues by a rapid gravimetric procedure. The precipitations of barium as the sulfate and phosphorus as ammonium phosphomolybdate are utilized. Complete precipitation of these compounds is achieved by use of a filter-aid.
Problems in the Chemical Diagnosis of Some Hereditary Metabolic Diseases
Authors: Tashian Richard E
Published: January 2020

Some hereditary or acquired, qualitative or quantitative differences in the urinary excretion patterns of certain phenolic acids, α-keto acids, and indolic acids have been reviewed and discussed. The ketoacidurias are summarized in Table 1. As can be seen, there is considerable overlap in the excretion of primary, and presumably secondary metabolites. From these comparisons together with the other disorders discussed throughout this presentation, the following conclusions might be drawn:

1. Phenylketonuria can be readily separated from the other ketoacidurias by the presence of increased amounts of o-hydroxyphenylacetic acid.

2. The increased excretion of α-ketoisocaproic acid and α-ketoisovaleric acid should be definitive for branched-chain ketonuria.

3. Secondary disturbances in tyrosine and tryptophan metabolism, which are associated with many of these disorders, are often expressed in an increased production of the tyrosine metabolite p-hydroxyphenylpyruvic acid and its derivatives (which appear to be characteristic of liver dysfunction in both hereditary and acquired diseases) and in an increased excretion of the tryptophan metabolites of indoleacetic acid, indolelactic acid, and indican, and a decreased excretion of 5-hydroxyindoleacetic acid.

4. Because of the biochemical or symptomatic similarities between many metabolic disorders, it is sometimes difficult to make an accurate diagnosis unless variations in the excretion patterns for each disease entity are thoroughly understood, so that overlapping factors or variations in one factor will not confuse the diagnosis.

5. The dietary and drug intake of the patient under observation must be assiduously controlled before an abnormal, or abnormally increased, metabolite can be assigned an endogenous metabolic origin.

Keeping these facts and precautions in mind should reduce the likelihood of reporting a variant of a known hereditary metabolic disease as a new disorder. Nevertheless, since the study of metabolic diseases is so new, it is important at this stage to report all significant variations of even the well-established diseases.
Estimation of Cholesterol in Small Quantities of Cerebrospinal Fluid
Authors: Sheff M F , Gretz M Denise , McMarlin J B
Published: January 2020

A method is described for the estimation of cholesterol in spinal fluid using the Tschugaeff reaction to produce a pink color proportional to the cholesterol concentration. The reproducibility and accuracy of the method are of a satisfactory order. The authors feel that, providing elementary safety precautions are observed, the method is suitable for the rapid routine estimation of cholesterol in small samples of spinal fluid.
A Simple, Stable Instrument for Determination of Bilirubin by Direct Spectrophotmetry
Authors: Jackson Sanford H
Published: January 2020

A description is given of a prototype instrument for the direct spectrophotometric determination of bilirubin in infant serum.

The instrument uses a mercury-arc emission lamp and interference filters to isolate monochromatic light.

Results given by this instrument are about 5 per cent higher than those by the Evelyn and Malloy chemical procedures but agree closely with those given by the Beckman DU spectrophotometer.
Quantitative Composition of Kidney Stones
Authors: Leonard Reid H
Published: January 2020

The kidney stone season for the Pensacola, Fla., area is shown to extend from May through November. No differences in composition of stones in and out of season could be found.

Classification of the calculi into five groups delineates the calcium oxalate and phosphate group as the typical stone. Calcium oxalate is more prominent than calcium phosphate, especially in sizes less than 10 mg.
Photometric Microdetermination of Total Serum Globulins by Means of a Tryptophan Reaction
Authors: Saifer Abraham , Gerstenfeld Shirley , Vecsler Francis
Published: January 2020

The Tauber perchloric acid method and the Fischl colorimetric procedure were combined into a quantitative method for tryptophan that is applicable directly to proteins without hydrolysis. The colorimetric tryptophan method was compared with both salt fractionation and electrophoretic methods for 26 normal sera and those from 51 patients with various chronic diseases. Analysis of the results for total serum globulins and A/G ratio in the three procedures indicated good agreement. Since serum globulins increase in diseases involving disturbed protein metabolism, accuracy of the determination increases as the disease progresses, whereas that for serum albumin falls. The tryptophan reaction is also directly applicable to low-protein fluids such as urine or cerebrospinal fluid, where salt fractionation technics are not suitable for determination of the A/G ratio. We confirmed Brackenridge's finding that increase in tryptophan content of malignant sera is due to increased total serum globulin level and not to increased tryptophan incorporation into a particular protein fraction.
X-Ray Spectroscopy in the Clinical Laboratory
Authors: Natelson Samuel , Sheid Bertrum
Published: January 2020

A procedure is described for the determination of protein-bound iodine of human serum with the X-ray spectrometer. The protein-bound iodine is extracted from serum at acid pH with alcohol-ether (3:1) solution. Evaporation of this extract results in the loss of the inorganic iodine. The residue is extracted with ammoniacal methanol, evaporated on filter paper, and exposed to the X-ray field. The Lα radiation is evaluated using the flow proportional counter. An instrument is described for evaporating the ammoniacal methanol in a confined area on the paper. The residue from the alcohol-ether extract may also be digested, with the liberated iodine distilled onto a small circle of filter paper (in a simple apparatus described) and the filter paper exposed to the X-ray field. The procedure requires 2 ml. of serum.

Levels obtained by this method are somewhat lower than those obtained by an ashing procedure followed by the ceric-arsenite reaction. The X-ray method is more precise than the conventional procedures. In preliminary studies, the mean normal value found by this method was 4.7 µg./100 ml. of serum, with a range of ± 0.6 (2 σ).
An Equilibrating Device for Use in Conjunction with the Automatic Determination of Carbon Dioxide-Combining Power
Authors: Marsters Roger W
Published: January 2020

The CO2 equilibrating device described has been found to yield results which are clinically satisfactory and, in addition, to render the automatic procedure for CO2-combining power simpler, more convenient, and less time-consuming. The method developed by Skeggs for the determination of carbon dioxide with the use of an automated system of analysis has been found to be practical, accurate, and reliable.
New Method for the Determination of Whole-Blood Iron and Hemoglobin
Authors: Connerty Harold V , Briggs Anglis R
Published: January 2020

A rapid, simple, highly accurate procedure for the determination of hemoglobin iron is described. The use of a sodium hypochlorite solution achieves a smoother, faster, cleaner digestion of hemoglobin and release of the iron than the use of concentrated sulfuric acid and persulfate.

The accuracy of the method is established by recovery experiments showing that a linear relation exists between the volume of a given hemoglobin solution analyzed and the total amount of iron released, as well as by the demonstration that a constant fixed ratio exists between hemoglobin iron and hemoglobin (as cyanmethemoglobin).

The new method is easier to perform than the time-honored procedure of Wong.
New Refractometric Methods for the Determination of Total Proteins in Serum and in Urine
Authors: Wolf A V , Fuller John B , Goldman E J , Mahony T D
Published: January 2020

New, precise, physical methods for the determination of total protein in serum or plasma and in urine are described. They are based upon the refractometric determination of total solids in these fluids before and after protein has been removed by coagulation and, in ordinary use, they require no special standardization or calibration. The urine method is applicable primarily to protein concentrations above 100mg./100 ml. A by-product of the urine method is the direct and simple determination of the nonprotein specific gravity of proteinuric urine.
Use of Micromethod for Phenylalanine in Management of Phenylketonuric Patients
Authors: Berry Helen K
Published: January 2020

A micromethod for measurement of blood phenylalanine is described. The procedure is advantageous in management of phenylketonuric children under treatment.
An o-Toluidine Method for Body-Fluid Glucose Determination
Authors: Dubowski Kurt M
Published: January 2020

o-Toluidine, 6% (v/v) in glacial acetic acid, is used to determine glucose in biologic material after deproteinization with 3% (w/v) trichloracetic acid. A stable green color develops after heating at 100° for 10 min., and the absorbance is determined at 630 or 635 mµ. The reagent is stable for many months at room temperature, and the reaction follows Beer's Law over a very wide range of concentrations. The development of the procedure is discussed, as is the specificity of the method for glucose.
Photometric Determination of Cerebrospinal Fluid Total Globulin and A/G Ratio with a Tryptophan Reaction
Authors: Saifer Abraham , Gerstenfeld Shirley
Published: January 2020

A previously described colorimetric tryptophan procedure for determination of serum total globulin and A/G ratio was modified so as to increase its sensitivity and suitability for determination of the small amount of globulins present in cerebrospinal fluid. Twenty-seven normal CSF specimens analyzed with the tryptophan method yielded a mean total globulin value of 14.0 ± 3.03 mg./100 ml., and a mean A/G ratio of 1.45 ± 0.25. These data are in good agreement with those reported for normal CSF specimens with the paper-electrophoretic method.

To demonstrate its clinical application in the diagnosis of neurologic disorders, the tryptophan method was used in the analysis of 51 CSF specimens from neurologic patients. Elevated total globulin values were obtained in 57 per cent. Six patients with normal total protein values showed decreased A/G ratios.
Microbiological Test for Leucine, Valine, and Isoleucine Using Urine Sample Dried on Filter Paper
Authors: Berry Helen K , Scheel Carolyn , Marks Joy
Published: January 2020

Urine specimens dried on filter paper squares were obtained from 700 mentally retarded children. A microbiological assay was used to screen the specimens for the presence of valine, leucine, and isoleucine. Three specimens gave positive tests for all three amino acids. A generalized aminoaciduria was observed in two specimens, and in the third, elevation of valine and leucine/isoleucine was confirmed by paper chromatography. The use of these screening procedures for early detection of children with maple sugar urine disease is suggested.
Paper Chromatographic Estimation of Phenylalanine and Tyrosine Using Finger-tip Blood
Authors: Culley W J , Mertz E T , Luce M W , Calandro J M , Jolly D H
Published: January 2020

A paper chromatographic method for the determination of serum phenylalanine and tyrosine has been developed that requires only 0.12 ml. of serum, no deproteinization, and no expensive equipment. This method has been applied to the detection of phenylketonuria and to check serum levels of phenylketonurics on low-phenylalanine diets.
Laboratory Tests in the Differential Diagnosis of Liver Disease Report on Two Procedures
Authors: Keyser J W , Payne R B , Stephens B T
Published: January 2020

The seromucoid estimation and the Jirgl test were investigated as aids in the differential diagnosis of jaundice or hepatomegaly. Subnormal concentrations of seromucoid strongly suggest hepatocellular disease, while in this series most patients with hepatitis or cirrhosis had normal or raised concentrations. In obstructive jaundice normal or high values may be found. Very high values suggest obstruction due to carcinoma, or the presence of secondary deposits of carcinoma in the liver. However, so many other conditions are associated with a raised seromucoid concentration that this finding must be interpreted with caution. The Jirgl test is not specific for posthepatic obstruction, being, in the authors' experience, usually positive in infective hepatitis and in carcinoma with secondary deposits in the liver, and occasionally in cirrhosis. It is suggested that the test responds to intra- as well as to extrahepatic obstruction.
Human Bile Proteins
Authors: Rawson Arnold J
Published: January 2020

A study of human bile by immunologic technics designed to identify proteins which are also found in serum shows that both albumin and gamma globulin are consistently present in both normal gallbladder bile and T-tube drainage bile. Also present in most specimens are several proteins of alpha and beta mobility sharing antigenic determinants with serum proteins.
Determination of Urine Dopamine
Authors: Bischoff Fritz , Torres Adolfo
Published: January 2020

The Duliere and Raper conversion of dopamine to 5,6-hydroxyindole is applied to urinary dopamine, which is concentrated and recovered by adsorption (pH 8.5-9.0) on and elution with dilute acetic acid from alumina. The spectrofluorometric readings are made at pH 5.3, with activation and fluorescence at 320 and 375 mµ, respectively. Proportionality between high and low internal standards is achieved when the 5,6-hydroxyindole reaction proceeds for 20 hours at room temperature. The increase of fluorescence with time adds specificity to the test. The recovery of standards added before adsorption on alumina compared with standards added after elution was 98 per cent.

Urinary dopamine was determined in normal individuals asleep and awake and in those with a number of pathologic conditions. The mean values were decreased in groups with Parkinsonism, diabetes, and cirrhosis of the liver. The study included 2 patients with pheochromocytoma.
Interferences in the Colorimetric Determination of Glucuronic Acid in Blood Serum
Authors: Mosher Robert E
Published: January 2020

The naphthoresorcinol reaction for the colorimetric determination of glucuronic acid has been investigated. The interference of glucose has been minimized by incorporating glucose, to approximate serum levels, in the glucuronolactone standards and adhering to exact analytic conditions. The colored product is extracted into β,β dichloroethyl ether and the absorbance is measured at 580 mµ.
A Routine Method for the Estimation of Serum Protein-bound Iodine
Authors: Bird R , Jackson Dorothy J
Published: January 2020

A method for the determination of serum protein-bound iodine (PBI) is presented. Chloric acid digestion is carried out in a single tube as described by other authors.

In order to shorten the period when close supervision is necessary, the digestion process has been reduced to 1 hour and the estimation completed within 4 hours. The method has been modified to make it a more manageable routine procedure for either single or multiple estimations of PBI. To overcome complications involved in temperature control, the final estimation of inorganic iodide by the catalytic reduction of Ce+4 to Ce+3 is carried out at room temperature. The value of this method as a thyroid function test is assessed in 125 cases.
The Ultramicro Determination of Salicylates in Biologic Fluids
Authors: Hanok Albert
Published: January 2020

A method for determining salicylates in ultramicro volumes of blood, spinal fluid, and urine has been investigated. This method combines the simplicity of one reagent for color development and deproteinization with a high degree of accuracy and precision. Apparent salicylate values in blood and spinal fluid of normal individuals are of the order of 0.7 mg./100 ml.

The application of this method to analysis of capillary samples of blood would be of value in the treatment of salicylate poisoning in children and in the maintenance of therapeutic salicylate levels in pediatric practice.
Incorporation of Sulfur Amino Acids by Leucocytes during Wound Healing
Authors: Williamson Martin B , Whalen Mary V , Haley Harold B
Published: January 2020

The effect of wounding on the uptake of S35-labeled amino acids by leucocytes of the blood was studied. Although a significant increase in the rate of uptake of cystine was observed after wounding, there appeared to be no effect on the incorporation of methionine. The effect was most pronounced on the third day after wounding; by the seventh day, the uptake of cystine had returned almost to the normal control rate. Experiments with substances which inhibit metabolism indicated that different mechanisms are involved in the uptake of methionine and of cystine by leucocytes.
Use of Tris (Hydroxymethyl) Aminomethane Buffer in Moving-boundary Electrophoresis of Serum
Authors: Sendroy Julius , Rodkey F Lee , MacKenzie Maxime
Published: January 2020

A tris-borate buffer solution of µ = 0.1 and pH 8.9 is shown to be satisfactory for use in the electrophoresis of human and bovine sera by the moving-boundary technic. Comparison of the patterns obtained by the use of tris-borate and barbital buffer is presented. Similar numbers of electrophoretically distinct components are found by the use of either buffer. Although the calculated mobility of albumin is slightly lower in tris-borate than in barbital, mobilities of the other serum components are similar in the two buffers. Several practical advantages of the tris-borate over the barbital mixture make the former buffer more than satisfactory as a replacement of the latter.
Stationary Phase as Color Reagent in Glass Paper Chromatography of Estrogens
Authors: Epstein Emanuel , Zak Bennie
Published: January 2020

A new technic has been described for the chromatographic separation of estrogens. It includes the use of a dual-purpose system where the impregnating material of the stationary phase (p-toluene sulfonic acid) is used as a color reagent after the separation is complete. This novel approach precludes the need for a spraying or dipping step to achieve the desired color reaction. Quantitation by densitometry and fluorescence is also detailed.
Errors Associated with the Direct Measurement of Human Serum Cholesterol Using the FeCI3 Color Reagent
Authors: Moore Robert V , Boyle Edwin
Published: January 2020

Evidence is presented concerning errors in the direct determination of human serum cholesterol with a ferric-chloride color reagent. It is shown that in physiologic concentrations the vitamins A, D, E, K, and niotinic acid cause no error, but that hemoglobin, anticoagulants, and impurities in acetic acid can cause errors. The control of these errors is discussed. Errors caused by steroids, added salts, and high bilirubin content of serum are discussed.
A Rapid and Sensitive Turbidimetric Method for Serum Lipase Based Upon Differences Between the Lipases of Normal and Pancreatitis Serum
Authors: Vogel William C , Zieve Leslie
Published: January 2020

A rapid turbidimetric method for the determination of serum lipase is described. The substrate is a nearly pure triglyceride in Tris buffer, with sodium deoxycholate as the emulsifying agent. The method is equal in sensitivity to the titrimetric measure of serum lipase using a modified Cherry-Crandall substrate.

The serum of patients with acute pancreatitis contains a lipase with optimal action at pH 9.1 and sodium deoxycholate concentration of 0.35%. These are different from the optimal pH and bile salt requirement for lipase activity in normal serum or duodenal contents.
Serum Glycoprotein Levels During Wound Tissue Regeneration
Authors: Williamson Martin B , DiLallo Lilita , Haley Harold B
Published: January 2020

The level of protein-bound hexoses was compared in several fractions of electrophoretically separated globulins in the sera of normal and wounded rats. Changes in the concentration of protein components which were not apparent from the amount of total protein of different fractions could be identified. Although wounding resulted in no change from the normal protein level of one α-globulin fraction, the protein-bound hexoses decreased significantly below the normal. In another α-globulin fraction from wounded animals, a parallel increase in both protein and hexose above the normal was observed. The total proteins in the β-globulin fraction were not affected by wounding, even though there was an appreciable increase in hexose in the wounded over the normal level. In spite of the marked decrease in the amount of protein in the γ-globulins of wounded rats, no significant difference in the hexoses associated with this fraction was observed. Other globulin fractions were unchanged during wound tissue regeneration.
Rapid Cellulose Acetate Electrophoresis
Authors: Bartlett Raymond C
Published: January 2020

A method of electrophoresis utilizing cellulose acetate is described wherein quantitation of serum protein fractions by densitometry is accomplished within 2 hr. of initiation of the procedure. The densitometer was found to have a linear response to amido black dye. Albumin and γ-globulin demonstrated equal dye-binding characteristics. Combined with the absence of albumin trailing, this has afforded excellent quantitations of serum protein fractions.
A Simple and Rapid Method for the Paper Electrophoretic Determination of Urinary Proteins
Authors: Collens Richard , Meyers Harry , Lange Kurt
Published: January 2020

A method is described for the simple, rapid, and accurate determination of paper electrophoretic patterns of urinary proteins using polyethylene glycol (Carbowax 20 M) for the concentration of the urine. The electrophoretic patterns of sera with normal and abnormal protein constituents did not change when added to a protein-free urine and subjected to the method described. The electrophoretic determination of urinary proteins as a routine procedure may give an insight into the physical type of permeability disturbance in the kidneys of a patient.
The Stability of Glucose in Serum
Authors: Ruiter Joseph , Weinberg Frederick , Morrison Andrew
Published: January 2020

The destruction of glucose does not occur in separated serum during the 48 hr. immediately following collection.

If necessary, the determination of the glucose level of serum can be delayed at least 48 hr. without introducing a significant error, provided the serum is removed from the clot immediately after collection.
Protein-Bound Iodine, Total Iodine, and Butanol-extractable Iodine by Partial Automation
Authors: Benotti Joseph , Benotti Norbert
Published: January 2020

The determination of iodine compounds in serum is simplified by using an automatic system to record the decolorization of the ceric sulfate solution. A method for modifying existing technics for PBI and BEI determinations, prior to this step, is described. Good agreement between the automated and manual technics was achieved.
Improvements on the Automatic Determination of Micro Amounts of Serum Calcium
Authors: Malmstadt H V , Hadjiioannou T P
Published: January 2020

Calcium in 0.2 ml. of blood serum can be titrated automatically in about 10 sec. with a reproducibility of 1-2%. It is not necessary to deproteinize the serum, and the complete procedure requires less than 1 min.