bluuebunny/crossref_metadata_2025_split huggingface dataset:
Absorbance of Various Protein-Free Filtrates of Serum
Authors: Henry Richard J , Berkman Sam 
Published: January 2020

Abstract
Absorbance curves have been run on protein-free serum filtrates obtained with trichloroacetic acid, tungstic acid, and zinc hydroxide. The background absorbance was highest in trichloroacetic acid filtrates, lowest in zinc hydroxide filtrates, and increased with decreasing wavelength. The possible error produced in photometric determinations by this nonspecific absorbance and means of correction have been discussed.
Enzymes in Clinical Biochemistry
Authors: King E J 
Published: January 2020

Abstract
In the paper by E. J. King in the Supplement to the August, 1957, issue of CLINICAL CHEMISTRY (Vol.3, No.4, Part Two), pages 510 and 511 do not appear. This is due to an error in pagination only, and the text is complete and in proper order. In the same paper, the insert consisting of Figs. 1 and 5, which should have appeared between pages 508 and 509, was incorrectly placed and will be found between pages 546 and 547.
Determination of Plasma Amine Oxidase Activity
Authors: Humoller Fred L , Majka Frank A , Barak Anthony J , Stevens J D , Holthaus J M 
Published: January 2020

Abstract
A detailed study of the Akerfeldt test for plasma oxidase activity has been carried out and it has been found that:
1. The optimum activity of the enzyme system involved occurs at pH 5.5-6.0.
2. The amount of plasma needed for the test at pH 6.0 can be reduced to 0.2 ml.
3. The reduced amount of plasma removed the inhibitory influence of albumin and a linear response was always obtained.
4. The inhibitory effect of albumin and glutathione is due in part to inhibiting the enzyme system, and in part to the reduction of oxidized DPP.
5. The inhibiting influence of Versene appears to be due to the chelating and inactivation of heavy metal catalysts.
6. The effect of ascorbic acid is solely one of increasing the lag period without inhibiting the enzyme system.
As a result of this study a modification of the Akerfeldt test is proposed. With this proposed method it was determined that the plasma oxidase activity, ACA, of 77 normal individuals was 8.0 ± 2.8 units. 4101 Woolworth Ave. Omaha 5, Neb.
Electrophoretic Migration Pattern of Serum Glutamic Oxalacetic Transaminase
Authors: Shepherd Herndon G , McDonald Hugh J 
Published: January 2020

Abstract
Using the combined technics of the ionographic separation of serum proteins in a paper-stabilized medium, as described by McDonald et al. (16, 17, 18), and the spectrophotometric procedure for the determination of transaminase activity developed by Karmen (3, 14), the electrophoretic migration pattern of the enzyme glutamic oxalacetic transaminase in rat serum has been examined. The major portion of the transaminase activity has been found to be associated with the α-2 globulin fraction of the serum proteins. Further evidence has been presented for the assumption of a nonionic linkage between the enzyme and its coenzyme, pyridoxal phosphate.
Vitamin B12 Excretion as Index of Hepatic Disorders
Authors: Baker Herman , Brill G , Pasher I , Sabotka Harry 
Published: January 2020

Abstract
Observations on lowered excretion of vitamin B12 after intramuscular injection of 60 µg. of this vitamin in hepatic disease have been extended and confirmed. Except for some borderline cases in other diseases with possible involvement of the liver, we find low excretion in rheumatic heart disease as well as in lobar pneumonia, previously reported. The mechanism underlying the deviations from the normal situation in liver disease and rheumatic heart disease in respect to the vitamin B12 binding factor, to the serum protein composition, and the role played by the kidney is the subject of current studies.
Practical Procedure for Estimation of Corticosterone or Hydrocortisone
Authors: Silber Robert H , Busch Robert D , Oslapas Raymond 
Published: January 2020

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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.
Studies on the Serum Proteins
Authors: Sunderman F William , Sunderman F William 
Published: January 2020

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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.
The Polarographic Determination of Selenium in Urine
Authors: Faulkner Albert G , Knoblock Edward C , Purdy William C 
Published: January 2020

Abstract
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.