bluuebunny/crossref_metadata_2025 huggingface dataset:
Photometric Errors in Equilibrium and Kinetic Analyses Based on Absorption Spectroscopy
Authors: Pardue Harry L , Hewitt Thomas E , Milano Michael J
Published: January 2020

We report a detailed analysis of the effects of photometric errors in absorption spectroscopy. We show that photometric errors can be divided into five categories, each having a different effect on the relative concentration error for equilibrium and kinetic analyses. Error coefficients defined for each category are incorporated into mathematical equations that permit one to calculate both systematic and random components of the error. We show that the transmittance for minimum error depends largely on the types of errors that predominate, and equations are presented that can be used to predict the optimum point for any combination of systematic or random error coefficients. These equations are applied successfully to one commercial spectrometer for which data were published recently and to two custom-designed spectrometers with very different performance characteristics. We think that this error analysis can be applied successfully to virtually any spectrometer currently used in clinical laboratories and that the results of the analysis will identify the nature and origin of the major sources of error. We believe this to be an essential step in any program aimed at improving reliability of analytical results.
Optimization and Analytical Applications of the Technique of Dynamic Introduction of Liquids into Centrifugal Analyzers
Authors: Burtis C A , Johnson W F , Overton J B , Tiffany T O , Mailen J C
Published: January 2020

The technique of dynamically introducing a measured volume of liquid into the spinning rotor of a miniature Centrifugal Fast Analyzer where it is subsequently apportioned into equal aliquots [C. D. Scott and J. C. Mailen, Clin. Chem. 18, 749 (1972)] has been further developed and improved. Several important structural and operational factors have been identified and investigated, including rotor design and geometry, rotor speed, injection volume and rate, and probe diameter. To determine the effect of these factors on the precision and accuracy with which a liquid may be dynamically introduced and apportioned, we developed a dye-dilution procedure. These studies demonstrate that liquid volumes ranging from 10 to 50 µl per cuvet can be dynamically loaded with an accuracy and precision (expressed as standard deviation) of 1 to 2% and 0.5 to 1.1 µl per cuvet, respectively. Several analytical applications of this technique have been investigated: (a) measurement of true sample-blank absorbance before dynamic reagent introduction, (b) sequential reagent addition, (c) correlation studies involving discrete versus dynamic loading of reagent, and (d) reconstitution of lyophilized reagents.
Techniques of Orthomolecular Diagnosis
Authors: Robinson Arthur B , Pauling Linus
Published: January 2020

Orthomolecular diagnosis is the process of determining and evaluating the concentrations of the substances normally present in the human body. This paper describes the general method that we are using for orthomolecular diagnosis.
Transphoresis and Isotachophoresis—Automatable Fast Analysis of Electrolytes, Proteins, and Cells, with Suppression of Gravitational Effects
Authors: Hinckley J O N
Published: January 2020

Transphoresis and isotachophoresis are defined as related fast high-resolution displacement electrophoretic methods, in which there are sharply separated compartments of uniform concentration, without gaussian zones. Electrical detection allows simultaneous analog or digital expression of quantity and identity from a single staircase signal. Use of free solution or dilute colloid in a capillary allows mechanical sample introduction, flushing, and reloading. Microliters of sample and inexpensive stock solutions are used and subnanomole quantities may be analyzed in minutes or seconds. All ions of one sign are analyzed simultaneously without staining, chemical reaction, or elution. The method is suitable for body fluids, and possibly for use with serum proteins. Temperature effects are less severe than in zone methods; but for proteins and cells gravitational distortions must be circumvented by rotation, stirring density gradients, or isopycnic solvents. Results of small ion, protein, and cell separations are given, and a separation in zero-gravity in Skylab is referred to.
Automatic Mass-Spectrometric Analysis: Preliminary Report on Development of a Novel Mass-Spectrometric System for Biomedical Applications
Authors: Dreyer W J , Kuppermann A , Boettger H G , Giffin C E , Norris D D , Grotch S L , Theard L P
Published: January 2020

A mass spectrograph, coupled to automatic sample preparation devices and an electro-optical ion detector/ computer system, capable of detecting many ion species simultaneously, presents a promising new approach to biomedical analysis. It will permit simultaneous multicomponent analysis of appropriately prepared samples and may detect as little as 10-15 g of a single component. This approach offers significant advantages over other methods, including conventional mass spectrometry.
Differentiation of Electrophoretically Similar Hemoglobins—Such as S, D, G, and P; or A2, C, E, and O—by Electrophoresis of the Globin Chains
Authors: Schneider Rose G
Published: January 2020

Electrophoresis of the globin chains of hemoglobin on cellulose acetate in both acidic and alkaline buffers (pH about 6 and 9) containing urea and 2-mercaptoethanol is a simple, rapid means of characterizing hemoglobins. Erythrocyte hemolysate is electrophoresed in the presence of a large amount of mercaptoethanol, which liberates heme from globin, and keeps it in solution during its rapid electrophoretic removal. Each globin chain migrates at a characteristic rate, which varies with the pH and composition of the buffer. The combined data permit differentiation, with a high degree of specificity, of some similarly charged hemoglobins. They may also be useful in assessing the effect of secondary and tertiary structure on molecular charge.
Simple, Accurate Solid-State Diode Photometer for Use in Measuring Oxygen Saturation of Whole Blood
Authors: Fesler R , Clerbaux Th
Published: January 2020

A small, easily-built photometer is described, in which a solid-state light-emitting diode is used as the light source and a phototransistor as the detector. The detector response is kept constant by modulating the diode intensity in proportion to the absorption characteristics of the sample being analyzed. Linearity and stability are good, even with turbid solutions (drift is <0.001 absorbance unit per hour). A typical application of this photometer is the continuous measurement of the percentage of oxyhemoglobin (0 to 100 %) in blood. For hemoglobin concentrations from 3 to 18 g/dl, the relation between oxyhemoglobin as estimated with this diode photometer and by a galvanic method (LEX-O2-CON) was: SO2LED = 0.993 SO2 % LEX + 0.69;r = 0.9975; n = 129; Syx = 1.59.
Elimination of Error Caused by Hemolysis and Bilirubin-induced Color Quenching in Clinical Radioimmunoassays
Authors: Helman Edith Zak , Spiehler Vina , Holland Susan
Published: January 2020

In radioimmunoassays and radioassays for various constituents of serum, color quenching is a source of error when liquid-scintillation methods are used in samples that contain hemolyzed blood and samples from jaundiced patients. A quench correction can be made by using the External Standard Channels Ratio method and normalizing the ratios, or, alternatively, by chemical decolorization with tetramethylammonium hydroxide, hydrogen peroxide, and ascorbic acid.
Methodological Causes of Discrepancies in Radioimmunoassay for Digoxin in Human Serum
Authors: Holtzman Jordan L , Shafer Rex B , Erickson Richard R
Published: January 2020

In our series of 73 patients, definite indications of toxicity were always associated with a serum digoxin concentration of 2.0 ng/ml or higher, while in the possibly intoxicated and nonintoxicated patients only 24% and 10%, respectively, had a concentration this high. The nonintoxicated patients included significantly more with subnormal serum albumin concentrations. In vitro addition of radiolabeled digoxin and antibody showed that sera from many patients with hypoalbuminemia will enhance the binding of the label, which could result in a digoxin radioimmunoassay value as much as threefold low. These results were unrelated to other serum constituents, including the associated hyperglobulinemia, or to methodologic problems in the immunoassay. The proportion of digoxin bound to serum proteins was not significantly different between the normal (38% ± 3%) and hypoalbuminemic (31% ± 3%) individuals, and so this could not explain the difference in the assay results. We conclude that patients whose serum albumin concentrations are low may show erroneously low radioimmunoassay values for serum digoxin, and that this may explain why some patients receiving high doses of digoxin are found to have unexpectedly low apparent concentrations of digoxin in their serum.
Determination of Copper in Plasma and Serum by Use of a Microsampling Cup in Atomic Absorption Spectrometry
Authors: Ward Arthur F , Mitchell Douglas G , Kahl Murray , Aldous Kenneth M
Published: January 2020

A microsampling cup procedure is described for rapid, precise determination of copper in plasma. Conventional Delves-cup atomic absorption spectrometry does not yield usable copper signals with blood plasma samples. Analytical sensitivity was improved 11-fold by use of cups fitted with an axial hole, a triangular cup-holding loop, and a smaller-bore absorption tube. The modified procedure yields relative standard deviations of 4-6% at the level of 95 µg of copper per deciliter. Analysis of 100 samples of blood plasma by both the microsampling cup procedure and a solvent-extraction atomic absorption procedure showed no significant difference between the two sets of data (P <.02).
Decreased Aspartate Aminotransferase ("SGOT") Activity in Serum of Uremic Patients
Authors: Warnock Laken G , Stone William J , Wagner Conrad
Published: January 2020

Aspartate aminotransferase activity in the serum of uremic patients and of normal individuals was analyzed by three different methods: (a) a manual ultraviolet method, (b) a manual colorimetric method, and (c) by continuous flow (SMA 12/60 AutoAnalyzer; Technicon). Both dialyzed and undialyzed uremic patients exhibit low values for serum aspartate aminotransferase activity, regardless of the method used. The SMA 12/60 procedure exaggerates this decrease because of ultraviolet-absorbing materials in uremic serum. The activity of this enzyme did not exceed normal values in one uremic patient after a myocardial infarction and recurrent severe cardiac episodes. Such results suggest that this procedure should be used with great care as an index for diagnosing myocardial infarctions (and perhaps hepatitis) in uremic patients.
Ultramicro Method for Serum Bilirubin by Diazo Blue Reaction
Authors: Stoner Ramon E , Weisberg Harry F
Published: January 2020

An ultramicromethod is presented for the determination of serum bilirubin by the (acid) diazo blue reaction, using heel puncture or fingertip blood. Diazotization is accomplished in a strongly acid medium with the resulting blue azobilirubin having a maximum absorption at 580 mµ. The method is extremely reproducible and sensitive, being carried out in final serum dilutions of 1:100 to 1:40. The method is described for use with the Coleman Junior spectrophotometer and can be adapted to other instruments.

The diazo blue micromethod compares very favorably with the Malloy and Evelyn method which was done in parallel. The results of this study also suggest that the diazo blue micromethod can be used on venous serum or serum obtained from fingertip puncture without having markedly altered results.
Some of the Variables Involved in the Fractionation of Serum Proteins by Paper Electrophoresis
Authors: Henry Richard J , Golub Orville J , Sobel Charles
Published: January 2020

Investigation of various steps involved in separation of serum proteins by paper electrophoresis and their quantitation by dyeing with bromphenol blue has revealed that the results obtained are quite dependent on a number of variables. It is essential, therefore, that rigid control of these variables be exercised and that normal values be obtained by the specific technic adopted.

Normal values have been given for the technic employed and data on stability of sera at room and refrigerator temperatures have been presented.
New Tests for Bile and Detection of Bile in Serum and Urine
Authors: Barakat M Z , Shehab S K , El-Sadr M M
Published: January 2020

1. New tests proposed for the detection of bilirubin have been described.

2. Application of some of the proposed tests on pathologic and normal serum and urine have been demonstrated.

3. The diazochlorides of certain amines previously reported as failures to detect bilirubin have been shown to be successful and have been applied to bile, serum, and urine.

4. Comparative sensitivity of the proposed tests and the most generally accepted tests for bilirubin in test solutions, pathologic serum, and urine have been given.

5. Spot tests suitable for the detection of bilirubin in pathologic urine have been presented.
Paper Chromatography of Free Amino Acids in Human Blood Serum
Authors: Jirgl Vladimir
Published: January 2020

A method has been described for the chromatographic separation on paper of free amino acids in human blood serum in which the previous desalting is not necessary.
Comparison of Plasma Uric Acid Levels Obtained with Five Different Methods
Authors: Kanabrocki Eugene L , Greco Joseph , Wilkoff Lee , Veach Roger
Published: January 2020

1. A comparison has been made of plasma values obtained by 5 different methods for uric acid estimation.

2. According to the uricase method, the plasma concentration of uric acid in fasting normal subjects ranged from 1.9-5.1 with average of 3.7 mg. per 100 ml.

3. The closest agreement with the uricase method was obtained with the method of Kern and Stranaky which gave normal values ranging from 2.8 to 4.9 with an average of 3.8 mg. per 100 ml.

4. A variation of about 25 per cent was observed in the plasma uric acid levels over a period of 7 weeks.
Measurement of Uric Acid in Biologic Fluids Using an Ion-Exchange Separation
Authors: Shapiro Bernard , Seligson David , Jessar Ralph
Published: January 2020

A new method for the measurement of uric acid in biologic fluids is presented. It involves the isolation of uric acid by ion-exchange separation and quantitative determination of uric acid in the eluate by ultraviolet absorption, the Folin-Brown method or an enzymatic technic. The enzymatic determination on the eluate is the most specific of the technics.

A series of determinations of uric acid in serum compares well with determinations on the same samples using the direct Folin-Brown procedure. The direct Folin-Brown method appears to be in error in determinations on certain urine samples. Measurements of uric acid in bile are reported. The technic can be used in the routine clinical laboratory, and is particularly applicable to fluids which cannot be studied by direct methods.
Estimation of Total Cholesterol in Serum by a Micro Method
Authors: Carpenter K J , Gotsis A , Hegsted D M
Published: January 2020

A method has been described for the estimation of total cholesterol in 0.02ml. of serum without the need for micro apparatus. It involves the measurement of the fluorescence developed after the addition of sulfuric acid to a solution of cholesterol in a mixture of 1,1,2-trichloroethane and acetic anhydride(1).

The results obtained with both human and rat sera have been in good agreement with those obtained with a standard colorimetric method(2), and the standard deviation for an estimation carried through in duplicate, owing to error within the method, has been ±4-5 mg. per 100 ml. under routine conditions.
Protein Level in Cerebrospinal Fluid
Authors: Sethna Shirley , Tsao M U
Published: January 2020

Results are given of simultaneous determinations of protein on 17 pooled cerebrospinal fluids (see Table 1) and 22 diluted sera and plasma specimens (see Table 2) by the following methods: micro-Kjeldahl; Johnston-Gibson tyrosine equivalence method; sulfosalicylic acid method; trichloroacetic acid method at 37° and two biuret methods. The micro-Kjeldahl method was used as the standard for comparison.
Determination of Ketone Bodies in Blood and Urine by Means of Vanillin in Alkaline Medium
Authors: Levine Victor E , Taterka Michael
Published: January 2020

Vanillin in an alkaline reaction mixture is a very sensitive reagent for acetone and diacetic acid. A qualitative and a quantitative method have been developed for the acetone bodies in blood and in urine by means of a vanillin-alkali reagent. Acetone and diacetic acid are distilled off and caught in a sodium bisulfite solution, which is allowed to react with vanillin in alkaline medium to form a color complex, which is measured spectrophotometrically.

Vanillin has many advantages over the salicylaldehyde method of Behre. These have been enumerated in the text.
Effects of Delayed Examination on the Results of Certain Hepatic Tests
Authors: Yonan Virginia L , Reinhold John G
Published: January 2020

Decreased thymol and zinc sulfate turbidity values often were observed after separated serum was refrigerated overnight. In some instances the changes were sufficient to affect appreciably the significance of the results. Phenol turbidity tended to increase considerably after refrigeration. Changes in thymol, zinc, and phenol turbidities were largely prevented by allowing serum to remain in contact with the clot during storage.

The use of anaerobic technic in the collection and storage of serum also prevented changes in the thymol turbidity measurements and, to a lesser extent, in the zinc turbidity. However, a large change in phenol turbidity persisted under these conditions.

The changes in zinc turbidity were related to the CO2 content of the sera being tested.

Serum bilirubin concentration tended to decrease slightly during storage.
Microtest for Mucopolysaccharides by Means of Toluidine Blue
Authors: Blumenkrantz Nelly
Published: January 2020

A micromethod is presented for the detection of hyaluronic acid when as little as 0.5 µg. of material are present. The method is simple and applicable as well to some other mucopolysaccharides.
A New Colorimetric Method for the Determination of Isoniazid in Biologic Fluids
Authors: Scardi Vincenzo , Bonavita Vincenzo
Published: January 2020

The authors describe a new colorimetric method for the determination of isoniazid in blood serum and cerebrospinal fluid.
Spectroscopic Data for Steroids Subjected to Zak Color Reaction
Authors: Bischoff Fritz , Turner John G
Published: January 2020

Spectral data in the range 320 to 700 mµ of the reaction products of 18 steroids subjected to the Zak color reaction were determined for possible use in identification and qualitative and quantitative determination. High extinction coefficients with characteristic peaks were found for a number of groupings.
Sources of Variation in a Standardized and a Semi-micro Procedure for the Spectrophotometric Assay of Serum Glutamic-Oxalacetic Transaminase Concentration
Authors: Schneider A J , Willis Myron J
Published: January 2020

1. Both a standard method and a semi-micro method for the spectrophotometric assay of serum glutamic-oxalacetic transaminase (S-GOT) concentrations have been described.

2. Either procedure is associated with an error defined by a factor of less than 1.03.

3. The temperature dependence of the rate of transamination was shown to follow Arrhenius' law over the range of temperature from 25° to 38°.

4. A tabulation of temperature factors calculated from the derived Arrhenius equation was presented. These factors permit correction of rates observed at temperature T to rates expected at 32°.

5. A comparison of normal S-GOT values from various sources was made, with correction for temperature differences. Based on 779 values from four different laboratories, the combined mean for adults was 21.9.

6. A standard unit of transaminase activity was defined and referred to as a Karmen unit. A Karmen unit represents that amount of transaminase in 1 ml. of sample which will cause a decrease in optical density at 340 mµ of 0.001 per minute at a temperature of 32°, an effective light path of 1 cm., and a volume of test solution of 3 ml. According to this definition, the mean normal adult S-GOT concentration is 21.9 Karmen units. The practical upper limit of normal will be defined in another publication.
Buffer Capacities of Human Blood and Plasma
Authors: Ellison George , Straumfjord Jon V , Hummel J P
Published: January 2020

Normal values for buffer capacity of blood and plasma of a number of normal subjects over various intervals between pH 7.5 and 6.1 were determined. The buffer capacities of blood and plasma were 38.5 and 16.1 mEq/L/pH respectively at physiologic pH values. Normal blood and plasma buffer capacities were relatively constant from pH 7.4-6.6. The buffer capacity of plasma proteins was found to be greater than that of bicarbonate at physiologic pH range. Variations of buffer capacity caused by certain disease processes are reported and discussed.
An Improved Periodic Acid Fuchsin Sulfite Staining Method for Evaluation of Glycoproteins
Authors: McGuckin Warren F , McKenzie Bernard F
Published: January 2020

Modification of the Köiw and Grönwall procedure for the staining of glycoproteins separated by paper electrophoresis has adapted this method to papers of the Whatman 3MM class, with achievement of results comparable to those reported by direct chemical determination of hexose in the individual protein fractions. Preliminary concentration of specimen fluids was achieved by ultrafiltration through collodion sacks. A preliminary wash of the oven-dried paper strips with 95 per cent ethanol was found essential to clear the paper of buffer salts and insure that the pH in the oxidation procedure remained in the 3.0-3.5 range. Close control of the reagent composition and timing of each step were found necessary. Inclusion of 40 per cent ethanol in the oxidation bath and immersion of dry strips were required to insure rapid penetration of the periodic acid. Control of the oxidation procedure at 20 ± 0.5° for 12 minutes was of prime necessity to maintain a low background color. Also, the concentrations of hydrochloric acid in the dye bath and in the wash solutions were found to affect the quality of the final stain. The ethanol wash served to remove residual sulfite and hydrochloric acid and stabilize the color.

The new method has been applied to the analysis of several body fluids of normal persons and patients with certain disease entities, and satisfactory glycoprotein distribution patterns have been obtained.
Micro Determination of Glutamic-Oxalacetic Transaminase in Blood Serum
Authors: Hermann Freya , Brookes Martha H , Storvick Clara A
Published: January 2020

A micro method for the determination of glutamic-oxalacetic transaminase activity in blood serum has been described. The method is a modification of the original method by Karmen as adapted by Steinberg, Baldwin, and Ostrow. A comparison of the methods indicates that equally reliable results were obtained by either method.
Staining Properties of Oil Red O and a Method of Partial Purification of the Commercial Product
Authors: Kutt Henn , Tsaltas Theodore T
Published: January 2020

1. A yellow-brown component of commercial oil red O separated by our technic of paper chromatography is shown to stain human serum proteins, particularly those that are coagulated by heat. The patterns of serum electropherograms obtained by coloring with the crude oil red O solution consist of a red lipid pattern superimposed on a brownish protein pattern.

2. A method is described for partial removal of the nonred components from the crude oil red O. Satisfactory coloration of lipoproteins was obtained with the "purified" oil red O.

3. It is demonstrated that areas of paper strip covered with protein may stain lighter with some oil red O fractions than the background filter paper.
A Microbiologic Method for Detecting Folic Acid Deficiency in Man
Authors: Baker Herman , Herbert V , Frank O , Pasher I , Hutner S H , Wasserman L R , Sobotka Harry
Published: January 2020

A microbiologic method based on Lactobacillus casei for assaying folic acid activity in serum is presented. The assay correlates directly with the clinical diagnosis. Comparison with formimino-L-glutamic acid determinations and other microbiologic assay methods shows the assay here described to yield a more dependable estimate of the folic acid status in humans.
Determination of Chloride in Blood Serum, Plasma, or Other Biologic Fluids by a New Rapid Precision Method
Authors: Malmstadt H V , Winefordner J D
Published: January 2020

The new, extremely sensitive and accurate precision null-point potentiometric method has been applied to the determination of chloride in blood serum or plasma and 2 simple procedures are described, one for deproteinized serum and the other for serum directly.

Measurements of chloride in diluted serum samples containing only 0.02 ml. blood serum can be carried out in less than 1 minute by the precision null-point potentiometric method with relative errors less than 0.5% for the complete procedure. Sample manipulations and all other operations for the chloride determination require about 1 to 3 minutes, the longer time for deproteinizing the serum. The same procedure is suitable for chloride determinations in other biologic samples, and the general considerations are presented.
Some Laboratory Aids for a Clinical Laboratory
Authors: Schepers Hiram H , Martinek Robert G
Published: January 2020

A power supply for laboratory instruments is described which has the following advantages.

1. It has greater utility than any commercially available unit now on the market and includes disaster planning in its construction.

2. It is relatively cheap to construct and does not require specialized knowledge for its assemblage.

3. It is relatively trouble-free and requires comparatively little routine maintenance.

A reliable, cheap, and convenient high intensity gas-air burner has been described for heat sealing the capillary tubes used in the micro hematocrit technic.
Studies of Cholesterol Methodology and Application to Population Surveys
Authors: Hollinger Nell F , Austin Elizabeth , Chandler Dorothy , Lansing Richard K
Published: January 2020

Comment is made on 7 methods with respect to replicate analysis and correlation with results of the Schoenheimer-Sperry determination of serum cholesterol. Estimates of variance are tabulated for 5 of the methods in terms of twice the coefficient of variation (2CVx); values range from 6.2% to 11.8%, averaging approximately 10%. For cholesterol standards, reproducibility of color development is somewhat better for standards equivalent to more than 200 mg./100ml.; the range of values for 2CVx is 3.8% to 39% above 200 mg. per 100 ml.; below that level 2CVx is 9.4% to 16.6% for photometric methods. On the basis of reproducibility and ease of performance the method of choice for the determination of total cholesterol is the Carr-Drekter.

As estimated from findings for 12 cases of atherosclerotic heart disease (ASHD) in a 4.9% sample representative of a survey of 3992 longshoremen, the incidence of ASHD is 87 per 1000 longshoremen having a total cholesterol of 230 mg./100 ml. or over; below that cholesterol level the incidence is 54 per 1000.
Determination of Carbonate in Biologic Solids
Authors: Sharp Robert F , Elliot James S , Lewis Leon
Published: January 2020

A procedure is described for the determination of carbonate in biologic solids by dissolving the material in a basic EDTA solution and utilizing the Van Slyke manometric apparatus.
Spectrophotometric Behavior of Azobilirubin and Azotaurobilirubin
Authors: Jirsa M , Jirsová V
Published: January 2020

The authors studied the influence of pH, alcohol, and albumin on the spectrophotometric behavior of azo dyes prepared from direct and indirect bilirubin by coupling with sulphanilic acid. Synthetically prepared taurobilirubin was used as a model for direct bilirubin. It was found that extinction and absorption maximum values depend on all 3 factors. Most important for practical purposes is the observed rise of azo dye extinction in serum and in albumin caused by alcohol. This means, if the Malloy and Evelyn method for the quantitative colometric estimation of direct bilirubin in serum is used, that part of the directly reacting taurobilirubin is estimated as indirect bilirubin. Revision of colorimetric methods for direct bilirubin estimation in serum is recommended.
A Modification of the Method for Prestaining Alpha and Beta Lipoproteins Separated by Paper Electrophoresis
Authors: Larkey Bernard J , Belko John S
Published: January 2020

A procedure is described for prestaining serum lipids for paper electrophoretic evaluation.
Improved Spectrophotometric Determination of Amylase with a New Stable Starch Substrate Solution
Authors: Rice Eugene W
Published: January 2020

A rapid spectrophotometric procedure for the determination of α-amylase activity by the use of the blue starch-triiodide ion complex is described. The method employs a Litner starch substrate solution which is preserved indefinitely by the incorporation of sorbic acid. Human cerebrospinal fluids consistently exhibit low amylase activity with the proposed method, the mean value being 2 "Somogyi" units.
An Assay for Pantothenic Acid in Biologic Fluids
Authors: Baker Herman , Frank Oscar , Pasher Inez , Dinnerstein Allan , Sobotka Harry
Published: January 2020

Methods for the assay of pantothenic acid in blood, urine, and cerebrospinal fluid using Lactobacillus plantarum and Tetrahymena pyriformis are presented. Tetrahymena, grown in a synthetic medium, provides a reliable assay control for establishing the range of the vitamin content in biologic fluids. The results show that pantothenic acid exists in the combined form and is equally concentrated in blood and cerebrospinal fluid; in urine it exists in the unconjugated form.
The Albumin/Globulin Ratio in Serum
Authors: Yeoman W B
Published: January 2020

1. A simple method is given for testing the efficiency of a salt fractionation method for the separation of albumin from globulins in serum or plasma. This consists of electrophoresis of the concentrated filtrate obtained by treatment of the specimen with the fractionating agent.

2. A method is presented for total precipitation of globulins in serum, or plasma with the use of a 27.2% sodium sulfate solution. Electrophoresis of the concentrated filtrates from such preparations reveals similarities close to the electrophoresis of pure albumin.

3. A comparison is made between the proposed salt fractionation technic and the results of electrophoresis in a series of 25 specimens. In this comparison, allowance of albumin trailing during protein paper electrophoresis is made. It is thought that the degree of agreement between the two methods would not have been so favorable if such an allowance had not been made.
Colorimetric Determination of Serum Isocitric Dehydrogenase
Authors: Taylor Thomas H , Friedman Michael E
Published: January 2020

A colorimetric assay of serum isocitric dehydrogenase has been described in which the α-ketoglutaric acid formed is determined as the hydrazone. A standard unit of lCD activity is defined as millimicromoles KG-A formed per milliliter serum per hour of incubation at 37°.

Analyses of KGA and TPNH as reaction products show that 1.58 moles of KGA are formed for each mole of TPNH under the conditions of this experiment.
Contamination of Malic Dehydrogenase with Apotransaminase
Authors: Zimmerman Hyman J , Silverberg Ivan J , West Michael
Published: January 2020

Studies of 4 commercially available malic dehydrogenase preparations have shown very small amounts of transaminase activity. Incubation of these preparations with pyridoxal 5-phosphate has revealed an enhanced transaminase activity. The data reported here suggest that the enhanced transaminase activity represents apotransaminase contaminating the malic dehydrogenase preparation.
Effects of Hemolysis on Serum Electrolyte Values
Authors: Mather Alan , Mackie Nellie Ray
Published: January 2020

The correction of serum potassium and phosphate values for erythrocyte contribution arising from hemolysis during blood collection may be made with a fair degree of confidence by evaluating the cellular potassium and phosphorus from the serum hemoglobin. The correction for potassium is appreciable, about 3.3 mEq./L. for each gram of liberated hemoglobin; the correction for phosphorus in fresh specimens is about one tenth as great, and may ordinarily be neglected.
Determination of Cholesterol with Special Reference to the Use of p-Toluenesulfonic Acid
Authors: Wright L A , Tonks D B , Allen R H
Published: January 2020

1. The Pearson, Stern, and McGavack method for the determination of cholesterol was found to be rapid and suitable for routine clinical purposes. It gave, within experimental error, total cholesterol values in agreement with the method of Bloor.

2. A proposed modification of the method, providing for a final volume of 6.3 ml., and a shorter operational time, was found to give values in excellent agreement with the original method.

3. Sulfosalicylic acid may be used as a substitute for p-toluenesulfonic acid. However, no evidence of the excessive reactivity reported from one source has been experienced at any time in this laboratory with the p-toluenesulfonic acid reagent.

4. Similar optical densities were obtained from equimolar quantities of cholesterol and cholesteryl palmitate when the Pearson, Stern, and McGavack method was used.

5. Serum cholesterol values for 61 normal males were found to range from 150 to 320 mg./100 ml. of serum.
Rapid Method for the Quantitative Determination of Serum Alkaline Phosphatase
Authors: klein Bernard , Read Prunella A , Babson Arthur L
Published: January 2020

A new procedure is described for the simple, rapid, quantitative measurement of serum alkaline phosphatase. The procedure is based on the direct photometric measurement of phenolphthalein released from sodium phenolphthalein phosphate. The substrate is available in a convenient, stabilized form as a tablet containing buffer and substrate in optimum amounts for a single analysis. As many as 30 analyses can be performed in an hour.
X-Ray Spectroscopy in the Clinical Laboratory
Authors: Natelson Samuel , Sheid Bertrum
Published: January 2020

Sulfur analysis in serum is performed with the X-ray spectrometer. The total sulfur content of normal serum in healthy adults is found to be 98 mg./100 ml. of serum ± 2.0 (2σ). This calculates to 1.44 gm. sulfur per 100 gm. of serum proteins ± 0.1 (2σ).

The distribution of sulfur in the paper electrophoretic fractions was assayed by performing the electrophoresis and passing the unstained paper through the X-ray field at a constant velocity; 69.3 per cent of the total serum sulfur is found in the albumin fraction. The other fractions contain, for alpha1, alpha2, beta, and gamma globulins, 4.2, 9.5, 9.5, and 7.5 per cent, respectively, as mean values for the 16 healthy adults. From the protein content of each fraction, determined by staining, the gm. of sulfur per 100 gm. protein is calculated for each fraction as follows: Albumin, 1.74; A,, 1.61; A2, 1.37; beta, 1.09; and gamma, 0.67.

The distribution of sulfur in the paper electrophoretic fractions from the two sera containing an abnormal fraction migrating with the gamma globulins was studied. The abnormal protein sulfur was low in these patients—only 0.18 and 0.16 gm. sulfur per 100 gm. of protein being found—as compared to 0.67 per cent in the normal. Both these sera came from patients with multiple myeloma.

In the serum of 2 patients, which had abnormal globulins traveling with the beta globulins, one contained level of sulfur elevated to 1.42 gm./100 gm. protein, as compared with 1.09 for normal beta globulin. The diagnosis in this case was multiple myeloma. In the second case the sulfur content was low-0.43 gm. sulfur per 100 gm. protein. In this case the diagnosis in the patient was equivocal.

Technics are described for determining the sulfur content of the different electrophoretic fractions with the X-ray spectrometer.
Study of Cholinesterase Activity in Nervous and Mental Disorders
Authors: Plum Claus Munk
Published: January 2020

Serum cholinesterase activity was measured in 193 patients with different mental diseases. It was found that there is an increase in the serum cholinesterase activity in patients suffering from manic depressive psychosis, schizophrenia, psychosis psychogenica, anxiety neurosis, and depressive neurosis. The results confirm some of those found in the literature. The reason for the increase in the serum cholinesterase activity cannot be explained. Drug therapy seems to have no direct influence on the enzyme activity, our experiments having been carried out over a period of about 4 years, with many different drugs used. The values reported in this paper are results of examinations carried out on the patients without any regard to their immediate psychic or mental condition, making it impossible to report on the influence of mental condition on the serum cholinesterase activity. No effect on the serum cholinesterase activity was found following electroshock treatment.
Nonionic Surfactants in Paper Electrophoresis
Authors: Graham W Donald
Published: January 2020

1. A modification of the usual paper electrophoretic procedure has been made by including in the buffer medium 0.05 per cent of certain alkylphenyl ethers of polyethylene glycol.

2. This modified procedure yields electrophoretic patterns of blood serum proteins that may be subdivided into 12 fractions— albumin, α1-globulin, three α2-globulins, three β-globulins, and four γ-globulins.

3. The method was applied to blood serum from 70 patients apparently free of significant disease and to sera from a number of patients with varied disease. More specific location of the altered protein levels was possible in a number of disease states.

4. Glycoprotein distribution was not seriously disturbed by the presence of the nonionic surfactants, but lipoproteins migrated at a decreased rate.
Studies on the Determination of Bile Pigments I. Standard of Purity for Bilirubin
Authors: Henry Richard J , Jacobs S L , Chiamori Neil
Published: January 2020

The purity of a number of commercial bilirubin preparations has been examined. A technic of purification of bilirubin is presented and certain characteristics of the product examined. Tentative standards of purity for bilirubin are proposed.
Rapid Method for Determination of Ascorbic Acid in Urine
Authors: Polk Andrew , Flanagan Thomas L , Van Loon Edward J
Published: January 2020

A rapid and accurate method for the determination of ascorbic acid in urine utilizing 2,6-dichlorophenolindophenol (DCPP) is described. This method eliminates the use of washed norit and reduces the incubation period from 3 hr. to 10 min.
Osmolarity of Human Serum and of Chemical Solutions of Biologic Importance
Authors: Hendry Edward B
Published: January 2020

With the use of the Fiske Osmometer, the mean total osmolarity of normal human serum was found to be 289 mOsM (S.D., 4), which is equivalent to a mean freezing point of -0.537°. The isosmotic concentrations of some important biologic solutions were determined. It was also found that M/15 solutions of disodium hydrogen phosphate and of potassium dihydrogen phosphate are very hypotonic, and that 3.8% sodium citrate is hypertonic. Hemolysis of erythrocytes in isosmotic ammonium chloride solution can be considerably delayed by the addition of 3.0% glucose to the solution. Isosmotic concentrations of disodium hydrogen phosphate and sodium dihydrogen phosphate were precisely determined, as were pH levels of buffer solutions made from these two salts. The cause of the slight changes in osmolarity that occur when these two isosmotic solutions are mixed is discussed.
Photometric Microdetermination of Serum Lipase with a Phenyl Laurate Substrate
Authors: Saifer Abraham , Perle Guta
Published: January 2020

The Raderecht and Moskau procedure for pancreatic lipase (6) has been modified for determining the small amounts of this enzyme present in normal blood serum. The present investigation confirmed their findings: that phenyl laurate provides a stable easily-prepared substrate of uniform composition; that the substrate is specifically split by serum and pancreatic lipase; and that the reaction product (phenol) can be readily determined by a simple and sensitive colorimetric procedure.

The lipase units are expressed in the same manner as are phosphatase units; i.e., milligrams of phenol liberated per 100 ml. serum at 370° in 30 min. The normal range, based on 40 sera, was found to be 2.5-5.6 units.

The serum lipase values were shown to be significantly elevated in a number of cases with acute pancreatic disease. The advantage of this procedure over others presently employed for diagnostic evaluation of these conditions is discussed.
Indole Metabolism in Mental Illness
Authors: Sprince Herbert
Published: January 2020

Abnormal indole metabolism, long implicated in mental illness, is well delineated in three diseases having mental symptoms: phenylketonuria, Hartnup (H or Hart's) disease, and pellagra. Recent research suggests that indole metabolism may be disturbed in schizophrenia. The evidence for this is evaluated in terms of: number and effectiveness of indolic psychotogens, effect of indoles on the brain, effect of psychotherapeutic drugs on model psychoses induced by indoles, excretion of urinary indoles before and after tryptophan load tests, animal toxicity tests, urinary glyoxylic acid test, and detection by paper chromatography of abnormal urinary indole production.

The indoles reported in human urine are discussed critically with respect to excretion data, metabolic origin, and possible relationship to mental disease. Urinary excretion studies in mental illness must consider such factors as medication, dietary differences, excretion products from intestinal bacteria, eccentric bowel habits, age, muscle mass, sex, physical activity, and adequate normal controls. In various reports, these factors were not well controlled. In some carefully conducted studies, however, abnormal excretion was still detected in schizophrenics, particularly in studies dealing with the glyoxylic acid test and 6-hydroxyskatole sulfate excretion. Despite the controversial aspects, reports of abnormal indole metabolism in mental illness are sufficiently numerous to warrant further studies along the lines indicated above.
Determination of Urinary 3-methoxy-4-hydroxymandelic Acid (Vanillylmandelic Acid) by Paper Electrophoresis
Authors: Klein Daniel , Chernaik Joseph M
Published: January 2020

A procedure is presented for the determination of 3-methoxy-4-hydroxymandelic acid (or vanillylmandelic acid) in urine. For separation from other phenolic acids, paper electrophoresis at low constant current is employed. Data are presented to show that this method is useful as a confirmatory test for pheochromocytoma, in which elevated urinary levels of vanillylmandelic acid are found.
Improved Rapid Procedure for Detection of High Protein-Bound Iodine Levels
Authors: Strickler Herbert , Cannon Yvonne , Campbell Elizabeth , Shellito Joanne
Published: January 2020

An improved screening test to detect grossly high levels of iodine in sera for protein-bound, iodine determinations is described. This is based on the methods of Grossman (2) and Ackerman and Myers (3).
Determination of Blood pCO2
Authors: Gambino S Raymond
Published: January 2020

It is demonstrated that the most accurate and precise method of determining whole blood pCO2 is with the Severinghaus modification of the pCO2 electrode. The coefficient of variation is only ± 0.33 per cent. Experiments show that the pCO2 may not be stable for more than 30 min. when whole blood is stored at O° when whole blood is diluted with saline, the pCO2 falls in exact proportion to the dilution.

The pH/log pCO2 curves of separated plasma and of whole blood have the same slope when temperature is changed. The pCO2 of cold-separated plasma is lower than the pCO2 plasma separated at body temperature. The variation of pCO2 with temperature appears to follow pari passu the variation of pH with temperature.

The mean pK' of 18 patient samples equilibrated at 37.5° was 6.103. The standard deviation was ± 0.012. Calculated pCO2, utilizing the Henderson-Hasselbalch equation, can have a coefficient of variation of ± 2.5 per cent if proper temperature corrections are made. If temperature corrections are not made, calculated pCO2 may have a coefficient of variation greater than ± 5 per cent.
Some Applications and Limitations of the Enzymic, Reducing (Somogyi), and Anthrone Methods for Estimating Sugars
Authors: Fales Frank W , Russell Jane A , Fain John N
Published: January 2020

The colorimetric glucose-oxidase and the Somogyi-Nelson reducing-sugar methods yield the same blood-glucose values when applied to carefully prepared zinc hydroxide filtrates of blood obtained from fasting individuals. The anthrone method yields values only slightly higher than those obtained by the enzymic and the reducing-sugar methods. Use of the enzymic method in conjunction with the reducing-sugar or the carbohydrate method allows the simultaneous accurate determination of other carbohydrates added to the blood, with only microquantities of blood being required for analysis. Possible applications include the galactose and fructose tolerance tests, the inulin clearance test, and the determination of the body water "space" of various carbohydrates.

To allow valid glucose determinations by the enzymic method, glutathione, cysteine, and amylase substrates such as glycogen must be absent.

The anthrone reaction with glucose is enhanced by chloride, bromide, and iodide. To eliminate interference of chloride with estimation of blood glucose, the samples must be diluted appropriately before analysis.
A Rapid Method for the Determination of Urea in Blood and Urine
Authors: Levine Jacob M , Leon Raul , Steigmann Frederick
Published: January 2020

A rapid method for the determination of urea in blood and urine based upon the urea-p-dimethylaminobenzaldehyde reaction is described. Results of determinations can be reported in 15 min. The method described is suitable for routine use in the clinical laboratory.
Analytic Methods for Bilirubin in Blood Plasma
Authors: Watson Derek
Published: January 2020

A critical evaluation of existing colorimetric and spectrophotometric methods for the determination of bilirubin in blood plasma is presented. The stoichiometric equivalences of the reagents used in the diazo coupling reaction are re-evaluated. The elimination of turbidity is discussed, as well as methods using diazo-coupling promoters. Recommendations are made concerning the preservation of specimens to prevent oxidation and procedures that give maximal specificity for the type of bilirubin pigment being assayed.