bluuebunny/crossref_metadata_2025_split huggingface dataset:
Specific Gravity of Blood and Plasma at 4 and 37 °C
Authors: Trudnowski Raymond J , Rico Rodolfo C 
Published: January 2020

Abstract
The specific gravity (relative density) of human whole blood and plasma from 25 healthy volunteers was determined gravimetrically. For whole blood it was found to be 1.0621 (95% confidence interval: 1.0652-1.0590) at 4 °C and 1.0506 (95% confidence interval: 1.0537-1.0475) at 37 °C. Plasma specific gravity was 1.0310 (95% confidence interval: 1.0324-1.0296) at 4 °C and 1.0205 (95% confidence interval: 1.0216-1.0193) at 37 °C. All of these values are referred to the density of water at 4 °C. We show the relationship between these values and those given in the literature for measurements at 25 °C. There was a small increase in whole blood specific gravity with increasing hematocrit, but it was not statistically significant over the 40-56 hematocrit range studied.
Reinterpretation of Hyperamylasemia in Diabetic Coma
Authors: Goldberg David M , Spooner Richard J , Knight Anthony H 
Published: January 2020

Abstract
Serum enzyme activity was sequentially determined in 10 consecutive patients with diabetic ketoacidosis, of whom all had increased β-glucuronidase activity, eight had increased amylase activity, and four had increased acid phosphatase activity. Activity of amylase and that of the two lysosomal enzymes were poorly correlated, irrespective of whether peak activities or activities of all samples were considered. Of 37 cases with acute viral hepatitis, serum β-glucuronidase activity was increased in 33 and amylase activity in four, and the correlation between the two was poor. Study of normal human liver showed that the ratio of its mean enzymatic activity to the upper normal limit for serum was less than 1.0 for amylase, and approximately 80 and 6000 for acid phosphatase and β-glucuronidase, respectively. The hepatocyte cannot be the source of an increased serum amylase activity, and we question whether lysosomes are concerned in its release from other tissues.
Immunochemical Measurement of Lipoprotein-X
Authors: Kostner Gerhard M , Petek Walter , Holasek Anton 
Published: January 2020

Abstract
Lipoprotein-X, an abnormal lipoprotein that is specific for cholestasis, was quantitated by immunochemical methods. Interfering lipoproteins also present in normal serum and sharing antigenic determinants with lipoprotein-X were removed before the sample was applied, by precipitation with purified anti-lipoprotein B or a γ-globulin fraction of specific lipoprotein B antiserum. On Laurell electrophoresis, peak height was linearly related to lipoprotein-X concentration in the range 0.20-10 g/liter of serum. Sensitivity could be increased further by staining the plates. The coefficient of variation was less than 5%. Single radial immunodiffusion (Mancini et al. technique) was somewhat less sensitive and accurate. Results were available after 3 h by Laurell's electroimmunodiffusion technique, and after 72 h by the technique of Mancini et al. Equivalent results were obtained for samples of lipoprotein-X of extrahepatic or intrahepatic origin.
Use of Co-Current Dialysis in an Improved Estimation of Free Thyroxine in Serum
Authors: Strickler Herbert S , Link Susan S , Grauer Robert C 
Published: January 2020

Abstract
A new method is described for measuring free thyroxine in serum, in which co-current dialysis is used to simplify and speed the determination. The patient's serum is mixed with 125I-labeled thyroxine and buffer (28 ml of serum per deciliter) and co-currently dialyzed for 15 min against a mixture of pooled serum (8 ml/dl) in buffer. After dialysis, the free thyroxine of the patient's serum, which is now bound to the protein of the recipient stream (pooled serum), is precipitated with trichloroacetic acid. The radioactivity of this precipitate and of an undialyzed serum aliquot is measured, to obtain the total count. Use of pooled serum and trichloroacetic acid eliminates the need for the amounts of carrier thyroxine required in most other methods. The procedure is both simple and rapid (3 to 4 samples/unit/h). The values for free thyroxine correlate well with those obtained by the method of Lee and Pileggi [Clin. Chem. 17, 166 (1971)] and by others participating in the proficiency program of the College of American Pathologists.
Clinical Evaluation of a Rapid Screening Test for Sickle Cell Trait (S[unknown]) and Sickle Cell Anemia (SS)
Authors: Louderback Allan L , Youhne Young , Fontana Anthony , Natland Martin 
Published: January 2020

Abstract
The need for a rapid screening procedure that differentiates both sickle-cell trait (S[unknown]) and sickle-cell anemia (SS) in a single test system has led to the development of a new 10-min screening test. The "Sickle-I.D." system is based on a modification of the sodium dithionite hemoglobin solubility test. It is composed of three reagents and requires 0.1 ml of whole blood. Two independent blind clinical comparisons of this new procedure with hemoglobin electrophoresis (4328 samples) revealed an accuracy of 99.8% in identification and differentiation of sicklecell trait and sickle-cell anemia. Together with confirmation of positives by hemoglobin electrophoresis, this new procedure provides rapid and accurate screening for sickle-cell trait (S[unknown]) and sickle-cell anemia (SS).
Stability in Urea as a Measure of Cardiac Lactate Dehydrogenase on the Centrifugal Analyzer
Authors: Hanson Naomi Quast , Freier Esther F 
Published: January 2020

Abstract
Kinetic methods are described for determination of total, heat-stable, and urea-stable lactate dehydrogenase (EC 1.1.1.27) activity on the centrifugal analyzer. In the urea-stable method we present, 2.6 molar urea is used to differentiate lactate dehydrogenase originating from heart and liver. This urea concentration, greater than that used by most other investigators, better differentiates between cardiac and liver lactate dehydrogenase and is as sensitive and specific for cardiac lactate dehydrogenase as the heatstable method; excellent correlation was obtained on 200 specimens assayed by both methods. The ureastable method has the advantages of speed and simplicity, better precision, and decreased serum volume, and is, therefore, preferred to the heat-stable method for determination of cardiac lactate dehydrogenase isoenzymes.
Use of a "Three-Isoenzyme Diagram" in Assessing Activity of Alkaline Phosphatase Isoenzymes
Authors: Kim Jae C , Stastny Milos , Manning John P 
Published: January 2020

Abstract
A "three-isoenzyme diagram" has been devised to visualize the alkaline phosphatase profile quickly. Activities of the individual isoenzymes can then be estimated from the diagram. Each vertex represents a pure alkaline phosphatase isoenzyme, thus forming a triangle with three alkaline phosphatase isoenzymes, each side of the triangle describing the concentration ratio of a binary mixture of the respective isoenzymes. The validity of the three-isoenzyme diagram was tested by mixing three sets of two abnormal sera in three proportions. Results show that linearity and proportionality agree with what would be assessed from the diagram.
Photometric Errors in Equilibrium and Kinetic Analyses Based on Absorption Spectroscopy
Authors: Pardue Harry L , Hewitt Thomas E , Milano Michael J 
Published: January 2020

Abstract
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

Abstract
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.
Transphoresis and Isotachophoresis—Automatable Fast Analysis of Electrolytes, Proteins, and Cells, with Suppression of Gravitational Effects
Authors: Hinckley J O N 
Published: January 2020

Abstract
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

Abstract
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

Abstract
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

Abstract
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 &lt;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

Abstract
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

Abstract
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

Abstract
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 &lt;.02).
Decreased Aspartate Aminotransferase ("SGOT") Activity in Serum of Uremic Patients
Authors: Warnock Laken G , Stone William J , Wagner Conrad 
Published: January 2020

Abstract
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

Abstract
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

Abstract
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

Abstract
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.
Comparison of Plasma Uric Acid Levels Obtained with Five Different Methods
Authors: Kanabrocki Eugene L , Greco Joseph , Wilkoff Lee , Veach Roger 
Published: January 2020

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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.