bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantitation of Serum IgG by Solid-Phase Radioimmunoassay
Authors: Cawley Leo P , Goodwin William L , Moeder Marilyn , Dibbern Paulette
Published: January 2020

Human serum immunoglobulins are most frequently measured by single gel diffusion. Radioimmunoassay by use of antibodies bonded to particles is faster and more sensitive, precise, accurate, and specific. We adopted a solid-phase radioimmunoassay (SPRIA) technique, developed in our laboratory, to measure serum IgG, and compared the results with those of a gel-diffusion method commonly used to measure serum IgG. The SPRIA technique is based on competition set up between antibodies to human IgG chemically bonded to cellulose particles and a purified serum IgG labeled with 125I. The solid phase permits prompt separation of the bound from free labeled reagent. We studied precision, accuracy, sensitivity, and specificity, as compared to gel diffusion; values for the two methods agreed well for 57 sera from hospital patients. The SPRIA procedure is more precise, and can be completed in 3 h, as compared to the 16-24 h normally required for gel diffusion procedures. The possible automation of SPRIA is discussed.
Variables in the Laboratory Diagnosis of Fabry's Disease by Measurement of Methylumbelliferyl-α-Galactosidase Activity
Authors: Brewster Marge A , Whaley Steve A , Kane Ann C
Published: January 2020

Assay of methylumbelliferyl-α-galactosidase activity (MUM-α-Galase) in plasma reflects the activity of ceramide trihexosidase and (or) ceramide digalactosidase, which are deficient in Fabry's disease. Intending to institute this assay routinely, we have evaluated substrate stability and concentration, sample stability, heat-inactivation conditions, and normal values. The heat-labile isoenzyme(s) deficient in plasma from patients with Fabry's disease must either be assayed immediately after sampling or the plasma must be stored at or below -50 °C. This heat-labile fraction can be inactivated by incubating a plasma aliquot at 45 °C for 45 min. Normal adult ranges for total and heat-labile MUM-α-Galase are 8.9-31.7 and 7.4-27.4 nmoles of MUM per hour per milliliter of EDTA-treated plasma.
Polymer Enhancement of Automated Immunological Nephelometric Analysis, as Illustrated by Determination of Urinary Albumin
Authors: Lizana Jorge , Hellsing Kristoffer
Published: January 2020

We have developed a new automated immunonephelometric method for determination of albumin in urine, by exploiting the polymer-enhancing effect on the immunological reaction. The original continuous-flow manifold has been simplified and the reaction time shortened to about 3 min. The antiserum was diluted 100-fold in a solution (100 g/liter) of polyethylene glycol (av mol wt, 6000) and mixed with the prediluted sample in the continuous-flow system. The method is highly sensitive and is unaffected by high blank and (or) high absorbance values of the specimens. Day-to-day variation was 3.8-4.3% (CV). Accuracy, as estimated from recovery experiments, was also good. A comparative study of 176 urines with the single radial immunodiffusion technique showed a correlation coefficient of 0.994. We therefore suggest the new method for routine use for determination of urinary albumin, because it is fast, accurate, precise, and sensitive, and requires only small amounts of antiserum.
Column-Chromatographic Analysis of Naturally Fluorescing Compounds: III. Rapid Analysis of Serotonin and Tryptamine
Authors: Chilcote D D
Published: January 2020

A previously described [Clin. Chem. 18, 778 (1972)] chromatographic separation and fluorimetric detection system has been adapted to the determination of serotonin and tryptamine. A strong cation-exchange resin, "Aminex A-6," is used. At a column temperature of 60 °C, serotonin and tryptamine are eluted in 0.5 and 1.0 h, respectively, with an ammonium acetate-acetic acid buffer solution (6 mol of acetate per liter). The sensitivity of the detector allows reliable quantitation of 100 ng of each amine in the sample loaded onto the column.
Protein-Binding Assay for Plasma Testosterone, after Purification by Column Partition Chromatography
Authors: Horgan E D , Riley W J
Published: January 2020

We describe a relatively simple, specific, and practicable method for measuring plasma testosterone by competitive protein-binding analysis. An ether extract is purified by a single chromatographic step on a micro-scale Celite—ethylene glycol column. Serum from women in the third trimester of pregnancy is used as the binding protein, and an ammonium sulfate precipitation step is used to separate the free and protein-bound testosterone. The method has a consistently low blank [0.59 ± 0.26 (SD) pmol/sample] and shows good precision. The mean testosterone concentration in normal men and menstruating women was 17.1 ± 4.0 (SD) and 1.2 ± 0.4 (SD) nmol/liter, respectively.
Gas-Chromatographic Determination of Methylmalonic Acid in Urine and Serum
Authors: Schiller Carol M , Summer George K
Published: January 2020

We describe a gas-chromatographic procedure for determining methylmalonic acid in serum and urine. The sample is acidified and the compound is extracted from it with diethyl ether, derivatized with N,O-bis(trimethylsilyl)trifluoroacetamide, and gas chromatographed. Precision and sensitivity of the method were verified by recovery studies and by comparing the results with those for an established procedure in which ion-exchange column chromatography and colorimetry are used. We analyzed biological fluids from normal individuals and from a patient with methylmalonic aciduria to show that the procedure can be applied to diagnosis of disorders that result in abnormally large amounts of methylmalonic acid in urine and serum.
Clinical Evaluation of Kinetic Enzymatic Fixed-Time and Integral Analysis of Serum Triglycerides
Authors: Tiffany T O , Morton J M , Hall E M , Garrett A S
Published: January 2020

Serum triglycerides can be enzymatically determined by hydrolysis of triglycerides to glycerol and free fatty acids [Clin. Chem. 19, 476 (1973)]. Enzyme integral (end-point) and fixed-time rate analyses of serum triglycerides by this procedure have been investigated with a centrifugal analyzer. We determined the precision of blank determinations, the contribution of normal serum alkaline phosphatase to total values, and the amount of endogenous glycerol in fasting serum samples and blood collection tubes. We also made a statistical analysis of enzymatic triglyceride values obtained for a healthy, fasting (12-16 h) population of men and women. The relative merits of both procedures are discussed.
Automated Fluorometric Creatine Kinase Assay. Measurement of 100-Fold Normal Activity without Serum Dilution
Authors: Armstrong J B , Lowden J A , Sherwin A L
Published: January 2020

Creatine kinase (EC 2.7.3.2) activity can be measured fluorometrically by coupling the reaction product, creatine, to ninhydrin at alkaline pH. We have automated this procedure to develop an accurate and precise method, which requires 0.1 ml of sample and can be performed at 60 tests per hour. By using an abbreviated incubation time and a dialyzer in the assay, we have extended the analytical range to 100 times normal serum activity without sample dilution. The dialyzer also eliminates the nonspecific protein fluorescence of the sample. An additional advantage of the method is the reduced cost of reagents in comparison to similar procedures. Serum blanks should be analyzed whenever serum creatine is abnormally high, especially in cases of severe renal failure.
Improved Assay for Spinal Fluid Glutamine, and Values for Children with Reye's Syndrome
Authors: Glasgow Allen M , Dhiensiri Kamnual
Published: January 2020

We describe a simple assay for spinal fluid glutamine, in which glutaminase is used to deaminate glutamine and the liberated ammonia is then measured with phenol hypochlorite. The concentration of glutamine in spinal fluid is increased in coma of hepatic origin. Spinal fluid glutamine was increased above normal at the time of admission in 20 of 27 cases of Reye's syndrome, of which hepatic dysfunction is apparently a feature. There was no correlation between the initial concentration of glutamine in spinal fluid and the ultimate outcome in these patients.
Immunoglobulin Concentrations in Sera of Normal Children: Quantitation against an International Reference Preparation
Authors: Čejka Jan , Mood Darlene W , Su Kim Chung
Published: January 2020

Immunoglobulins G, A, and M were quantitated in sera from healthy children of various ages by using a standard related to the international reference preparation for human serum immunoglobulins. The results, expressed in International Units per milliliter, provide a basis for the establishment of normal immunoglobulin values in different laboratories.
Rapid Ultraviolet Procedure for Measuring Doxepin and Some Doxepin Metabolites in Human Urine
Authors: Randolph Warren C , Walkenstein Sidney S , Joseph Gerald L , Intoccia Alfred P
Published: January 2020

A method is described for measuring doxepin-related material excreted in urine. Unchanged doxepin and certain doxepin metabolites are oxidized to doxepin ketone with KMnO4. The doxepin ketone is extracted with n-hexane and quantitated by ultraviolet spectrophotometry at the absorption maximum, 266 nm. This method is fast, reproducible, and measures a greater percentage of doxepin-related material than do existing gas—liquid chromatographic procedures. Doxepin ketone was measured to provide bio-availability data, for comparison of different formulations in humans.
Comparison of Four Methods for Determination of δ-Aminolevulinic Acid in Urine, and Evaluation of Critical Factors
Authors: Roels Harry , Lauwerys Robert , Buchet Jean-Pierre , Berlin Alexander , Smeets Jan
Published: January 2020

Four methods—two requiring ion-exchange chromatography of urine (Mauzerall-Granick; Davis-Andelman) and two omitting the chromatographic step (Grabecki et al.; Lauwerys et al.)—for determination of urinary δ-aminolevulinic acid (I) have been compared. Experienced analysts obtained a satisfactory coefficient of variation (≤5%) for each of the four methods. Over the whole concentration range of 0 to 60 mg/liter, both chromatographic methods gave identical results. At concentrations <6 mg/liter, the automated method of Lauwerys et al. gave slightly higher results than did the chromatographic methods. At concentrations >6 mg/liter the values of I obtained with the automated method were almost identical with those yielded by the chromatographic methods, whereas with the method of Grabecki et al. one-third less was found. The results for the automated method correlated better with those for the two chromatographic methods than did those for the method of Grabecki et al. Quality control of prefilled commercially available columns (Bio-Rad) and standard solutions of I (100 µg/ml) gave results with a low variability (<10%). Ionic strength and pH of urine do not influence significantly the determination of I by the automated method, but influence determination of I by the Davis—Andelman method. With or without a preservative, I can be conserved for at least two weeks, if urine is kept at 4 °C. Tartaric acid (1 g/100 ml) or acetic acid (1 ml/100 ml) are satisfactory preservatives for urine stored in darkness at room temperature; sodium azide or thymol are less effective than acidification. During storage the concentration of I in urine decreases as pH increases (above pH 6). Only a moderate effect of natural daylight was observed.
Two Ultramicro-Scale Methods for Plasma Uric Acid Analysis with Uricase
Authors: Meites Samuel , Thompson Carlotta , Roach Ralph W
Published: January 2020

Results with two ultramicro methods for plasma uric acid analysis with uricase are described: a crystal violet (gentian violet) method, modified from an automated procedure by Gochman and Schmitz [Clin. Chem. 17, 1154 (1971)] and adapted to manual analysis, and a polarographic oxygen-sensing system (Beckman Instruments, Inc.). The coefficient of variation (CV) for the crystal violet method varied between 2.1 and 5.7% for an 11-month period. Within-run precision (CV) of the polarographic method was 3.3%; day-to-day CV varied between 3.4 and 9.4%. Percentage recovery for the crystal violet method ranged between 97 and 106%, and for the polarographic method between 92 and 100%. Results of the two methods correlate well, but 5-15% lower values are obtained by the crystal violet method than by the polarographic method. Bilirubin, hemolysis, or usual plasma concentrations of ascorbic acid do not interfere significantly with either method. Advantages and disadvantages of both methods are discussed. The polarographic method requires more uricase, but is the better of the two methods.
Discrete Sampling Dilutor Used in Atomic Absorption Spectroscopy, with a Modification Permitting Simultaneous Analysis for Total Calcium and Inorganic Phosphorus
Authors: Ladenson Jack H , Davis J E
Published: January 2020

A discrete sampling dilutor (the Beckman Klina dilutor) is a convenient adjunct to atomic absorption spectroscopy. The addition of a Micro switch enabled the dilution cycle to be started by the movement of an AutoAnalyzer Sampler. This minor modification permits the contents of the same sample cup to be used for determination of calcium by atomic absorption spectroscopy and of inorganic phosphorus with the AutoAnalyzer.
A Low-Noise Thermistor Bridge for Use in Calorimetry
Authors: Berger Robert L , Friauf Walter S , Cascio Horace E
Published: January 2020

A precision thermistor bridge and thermistor is described for use in a thermal titration calorimeter or a high-speed stopped- or continuous-flow calorimeter of the Roughton type. These are compared and evaluated with regard to several other types of detectors, including the platinum resistance thermometer, thermocouple, transistor thermometer, and capacitance thermometers. At this time the best detection for our purpose seems to be a specially constructed 20-100 kΩ thermistor used in conjunction with a new ac lock-in amplifier bridge. The sensitivity of the system is equivalent to a peak-to-peak noise of 25 x 10-6 °C, with a 100-ms time constant and 1 µW power dissipation in the thermistor. Long-term drift of the bridge, without an oven, was 1 x 10-6 °C/min.
Thermal Titration: Application of Calorimetry to the Study of Plasma Coagulation
Authors: Watt D , Berger R L , Green D , Marini M A
Published: January 2020

We studied the coagulation of plasma by thrombin with a titration calorimeter at 20 °C. When thrombin is added to plasma, three distinct alterations in the thermal pattern are seen. The precoagulation region is generally exothermic, although occasionally, with some plasmas, cooling is observed. The coagulation region is defined by a sharp exotherm, a plateau, and then a sharp endotherm. Postcoagulation is generally a long exothermic region, which is partially the result of frictional heat produced from the coagulum. Plasmas from five normal patients were assayed. The thrombin clotting times ranged from 33 to 48 s (SD, 3 s). After storage at -20 °C for 10 days, the plasma showed a decrease of about 8 s in the clotting time. Coagulation times were found to depend on both the fibrinogen concentration and the thrombin concentration in addition to other unknown factors. Fibrinogen content correlated roughly with the heat rise during coagulation. Heparin (final concentration, 0.25 units/ml) prevented coagulation for more than 15 min after the addition of 12.5 units of thrombin. Under normal conditions, 25 milliunits of heparin per milliliter doubled the clotting time. Coagulation of fibrinogen alone gave a different thermogram in that the coagulation region was prolonged and there was very little or no heat generated after the clot had formed.
Instrumental Detection System Based on Light Scattering for Performing Assays in Which Agglutination Reactions Are Used
Authors: Blume Philip , Hanson Margaret , Mathys J , Polesky Herbert F
Published: January 2020

The presence of even a small extent of agglutination among erythrocytes in aqueous suspension can be ascertained by a discrete-particle light-scattering technique. This provides a means of mechanizing a wide variety of assays done in connection with blood-banking, as well as other procedures that rely upon the agglutination of sensitized particles or cells. We describe an agglutination-detection system designed to serve this function, and demonstrate its sensitivity.
Blood Grouping with a Miniature Centrifugal Fast Analyzer
Authors: Tiffany T O , Parella J M , Burtis C A , Johnson W F , Scott C D
Published: January 2020

The Centrifugal Fast Analyzer was used to develop a semiautomated, computerized blood-grouping system. A miniaturized version of the Analyzer was used for the development because, essentially, it enables one to automate "test-tube" grouping procedures. The blood-grouping system is discussed in terms of adaptation of blood-grouping procedures; types of instrumentation used for grouping, cell washing, and Coombs testing; parametric optimization of hemagglutination reactions; subgrouping of A and AB; reverse typing; small-scale blood-grouping evaluation of our approach; and computerization of blood grouping. The data reported here indicate that the system reliably provides accurate results.
Specific Protein Analysis by Light-Scatter Measurement with a Miniature Centrifugal Fast Analyzer
Authors: Tiffany T O , Parella J M , Johnson W F , Burtis C A
Published: January 2020

A miniature Centrifugal Fast Analyzer has been modified for fluorescence and light-scatter measurements by using several rotors developed for this purpose. The modified system has been used to evaluate the feasibility of adapting specific protein analyses, such as IgG, IgA, IgM, C'3 complement component, and α-1-antitrypsin, to the Centrifugal Fast Analyzer. A study of reaction conditions has revealed that the addition of polyethylene glycol 6000 (Carbowax) to the dilution medium increases the rate of reaction and allows apparent equilibrium to be achieved in less than 60 s. Furthermore, scatter intensity is enhanced. This system can be used to make rapid immunoglobulin measurements with only microliter volumes of antibody (2-7 µl), without the need of sample blanks. Determination of antigen excess by a method that involves dynamic injection of antibody is also discussed.
A Versatile Minidisc Module for a Centrifugal Analyzer
Authors: Renoe B W , Gregory R P , Avery J , Malmstadt H V
Published: January 2020

We have developed a centrifugal minidisc module, which extends the versatility of the centrifugal analyzer system with respect to radiation sources, wavelength selectors, radiation detectors, and the analysis performed by the system. The motor, brake, power supply, and control circuitry for the sample/reagent minidisc unit has been repackaged in a compact module, which is easily attached to an optical reference base. Appropriate wavelength selectors, source, and detector modules can then be easily aligned with the minidisc module. Use of a programmable ultraviolet—visible monochromator can provide the automated wavelength selection necessary for application to simultaneous multi-type analyses. Design features of the centrifugal minidisc module are presented, and its versatility is illustrated.
Validity of a Simple Automated Method in Which the "Direct" Kober Reaction is Used to Measure Estrogens during Pregnancy
Authors: Ismail Adel A A , Watson Susan M
Published: January 2020

Using a simple automated procedure for measurement of total estrogens in urine, we found that several estrogen conjugates gave higher fluorescence yields than did the corresponding free steroids. In the analysis of urine samples from pregnant women, the "direct Kober reaction" gave consistently higher values than those obtained after preliminary acid or enzymatic hydrolysis. The effects of storage and urine dilution on results for estrogens were also investigated.
Separation of Free and Protein-Bound Ligand Molecules by Means of Protein-Coated Charcoal
Authors: Mortensen Esper
Published: January 2020

Separation of free and protein-bound ligand molecules by means of protein-coated charcoal has been studied in model experiments. The results can be described by applying the simple laws of mass action and dilution, and indicate the need for a careful evaluation of the charcoal that is being used and a testing against an ideal separation method whenever experimental conditions are determined or changed.
Creatinine Metabolism in Humans with Decreased Renal Function: Creatinine Deficit
Authors: Jones James D , Burnett Philip C
Published: January 2020

This study was designed to test the hypothesis that, in a patient with decreased renal function and an increased plasma creatinine concentration, a significant quantity of creatinine is excreted into the gut, as is true of urea and uric acid, and is metabolized by gut flora. [Methyl-14C] creatinine was given intravenously to five patients and [methyl-14C] creatinine or [carbonyl-14C] creatinine was given orally to five patients. Extracts of excreta, plasma, and urine were subjected to ion-exchange chromatography, with monitoring for 14C and for ninhydrin-positive material. Respiratory gases, collected in acid and base, were assayed for radioactivity. Blood specimens were obtained at intervals to furnish data on decay of labeled creatinine in the body pool. The data show that there is a true creatinine deficit (15.9 to 65.7% of the creatinine formed is metabolized or excreted via extrarenal routes) in patients with decreased renal function. In these patients, creatinine is metabolized to CO2 and methylamine, presumably by the microflora of the gut. A significant portion of the carbonyllabeled creatinine appeared in plasma in an unidentified compound.
Possible Interference by Chlordiazepoxide or Its Metabolites with Some Clinical Chemical Procedures
Authors: Spiegel Herbert E , Sunico Hilda , Scarince Darlene
Published: January 2020

We examined the effect on some clinical chemical assays of adding chlordiazepoxide or its two metabolites, the lactam and the N-desmethylchlordiazepoxide, to serum or urine. We also examined the effect on urinary steroid values of administering the drug for as long as 20 days. The drug, in 10-fold the expected concentrations in blood, or its metabolites, in 200-fold the expected concentration in blood, had no significant effect on serum values for aspartate aminotransferase or alkaline phosphatase activities, values for bilirubin, albumin, or total protein, or on the electrophoretic pattern for serum proteins. Although values for urinary 17-hydroxycorticosteroids were slightly increased in addition experiments, we saw no effect of actual administration of the drug on values for either 17-hydroxycorticosteroids or 17-ketosteroids in urine.
Identification of Human Hemoglobins
Authors: Goldberg C A J
Published: January 2020

Practical physical and chemical procedures available for the identification of hemoglobins have been discussed. These include electrophoresis, chromatography, alkali denaturation, and ferrohemoglobin solubility. The conditions essential for satisfactory electrophoretic separations have been considered and two procedures for paper electrophoresis at pH 6.5, 7.8, and 8.6 using apparatus for compressed paper strips and for freely suspended horizontal strips are presented. A method for the determination of ferrohemoglobin solubility also has been described.
Measurement of the Electrical Conductivity of Sweat
Authors: Licht Truman S , Stern Milton , Shwachman Harry
Published: January 2020

1. A method has been described for the measurement of the electrical conductivity of thermally induced sweat.

2. Conductivity data of sweat samples collected from 124 children ranging in ages from 4 weeks to 16 years is presented. Forty-seven patients have cystic fibrosis of the pancreas and exhibit a mean value for the sweat conductivity of 16,150 micromhos/cm. In the remaining 77 subjects, of which 6 were healthy and the others had miscellaneous illnesses, the mean value for the sweat conductivity is 5,560 micromhos/cm. All of the subjects with sweat conductivities less than 9000 micromhos/cm. did not have cystic fibrosis; all of the subjects with sweat conductivities greater than 12,000 micromhos/cm., with one exception, had cystic fibrosis. The intermediate range (9000 to 12,000 micromhos/cm.) comprised less than 10 per cent of the subjects studied. It has been shown that measurement of chloride and/or sodium concentration in sweat is a more reliable diagnostic index of cystic fibrosis of the pancreas.
Effect of Various Protein Precipitants on Recoveries of Creatinine Added to Plasma
Authors: Van Pilsum John F , Bovis M
Published: January 2020

The effect of various types of protein precipitation procedures upon the recovery of creatinine added to blood has been investigated. Complete recoveries of creatinine were obtained with tungstic acid, trichloroacetic acid, perchloric acid, and cadmium hydroxide types of protein precipitation. Incomplete recoveries were obtained with Ba(OH)2 + ZnSO4 and NaOH + ZnSO4 types of protein precipitation.

A comparison was made of the normal values for creatine and creatinine in whole blood and plasma obtained by the picric acid and by the o-nitrobenzaldehyde methods of analysis. The o-nitrobenzaldehyde values were 97, 43, 40, and 80 per cent of the picric acid values for whole-blood creatine, whole-blood creatinine, plasma creatine, and plasma creatinine, respectively.
Urobilinogen Excretion in Normal Adults
Authors: Balikov Bernard
Published: January 2020

Using the quantitative methods of Schwartz, Sborov, and Watson, as modified by Balikov, normal ranges for excretion of urobilinogen have been determined for adults. The individual values fall into a logarithmic type of distribution.

The normal range for urine urobilinogen excretion is from 0.05 to 2.5 mg./24 hours, with a median of 0.36. The excretion of fecal urobilinogen ranges from 57 to 200 mg./24 hours for males and from 8 to 150 mg. for females. The medians for these groups are 101 and 40 mg., respectively.
Simple Specific Test for Urine Glucose
Authors: Free Alfred H , Adams Ernest C , Kercher Mary Lou , Free Helen M , Cook Marion H
Published: January 2020

A simple, specific, sensitive, and speedy test for glucose in urine has been described. This enzymatic test based on the activity of glucose oxidase and peroxidase is called Clinistix. Data are presented to show that the test has a high accuracy with both positive and negative specimens.
Photometric Procedure for Determining Esterase Activity
Authors: Ramsey Harold A
Published: January 2020

A procedure for determining the esterase content of biologic tissues and fluids has been presented. Fatty acid esters of 2-naphthol are employed as substrates. The 2-naphthol liberated by hydrolysis is coupled with a diazonium salt to form an azo dye, the concentration of which is estimated photometrically. Distinctive features of this method are (1) the use of Brij 35 to prepare nonopalescent solutions of substrate,(2) the adjustment of pH to ensure complete formation of the azo dye, and (3) the solubilizing of the azo dye by adding sodium hydroxide. This assay procedure is sensitive to very small amounts of esterase, and the stability of its color is excellent if proper precautions are taken.
Direct Nesslerization of Blood and Urine Filtrates in the Determination of Urea (as Ammonia)
Authors: Boutwell Joseph H
Published: January 2020

1. The sources of turbidity in directly nesslerized blood and urine filtrates have been discussed and a new method of nesslerization has been presented which eliminates turbidities. The new procedure has been compared in a quantitative manner with several methods.

2. A procedure for the determination of blood and urine urea and for urine ammonia has been presented, incorporating the new nesslerization technic.
Urinary Peptide Excretion in the Burned Patient
Authors: Balikov Bernard , Castello Robert A , Lozano Eloy R
Published: January 2020

The pattern of peptiduria in serious burns has been presented. This pattern has been found to vary, depending upon whether the patient's condition deteriorates or improves. The changes in this pattern resulting from various complications often seen in an extensive burn have been noted.

Evidence has been presented supporting the theory of the endogenous origin of urinary peptides.
Partition Chromatography of Organic Acids in Body Fluids with Silica Gel
Authors: Meites Samuel
Published: January 2020

1. A method for the extraction of non-α-amino organic acids from urine based on the work of Isherwood is described.

2. The relative position of elution of 42 biologically significant acids from silica gel columns is demonstrated. A number of important acids known to be present in urine are not eluted.

3. The partition chromatography of urinary organic acids reveals the presence of 9 peaks, of which 4 are known to be acetic, formic, lactic, and citric acids. A fifth peak contains glycolic and oxalic acids.

4. The aromatic acids are eluted principally in the first peak, which contains hippuric acids as a major constituent.

5. A minimum of two unknown organic acids are constantly present in relatively large concentrations in urine. Two additional acids appear frequently.
A Semimicro Technic for the Measurement of N,N-Dimethyl-P-Phenylenediamine (DPP) Oxidase in Blood
Authors: Goldschmidt Leontine
Published: January 2020

A semimicro method for the evaluation of DPP oxidase activity in blood serum and plasma has been reported and its advantages have been described.
Determination of Vitamin B12 With an Escherichia Coli Mutant
Authors: Aronovitch J , Grossowicz Nathan
Published: January 2020

An improved method for the determination of vitamin B12, using a more sensitive mutant of Escherichia coli, which enables determination of 4-20 µµg./ml. of the vitamin, has been described. Comparative determinations of vitamin B12 content of human sera and of animal tissue extracts gave similar values when assayed with both E. coli and O. malhamensis. Although O. malhamensis is more specific in its response to cyanocobalamin than E. coli, the latter organism seems just as reliable for determination of vitamin B12 in serum and in tissue of human and animal origin. The simplicity, rapidity, and sensitivity of the improved E. coli assay make it very suitable for clinical use.
Salting-Out of Serum Proteins after the Addition of Known Protein Fractions
Authors: Pagliardi E , Vitelli A , Gaidano G
Published: January 2020

Salting-out of sera to which known protein fractions had been added was performed, and parallel determinations were performed on the unaltered serum in every case. Two types of phenomena were observed: the added fraction apparently always precipitates in its characteristic range, and the addition of proteins sometimes did not modify the precipitation of the serum proteins, but in other cases determined important changes of the precipitation diagram. The study of these changes proved the occurrence of processes of interaction between the various protein fractions of the sera.
The Influence of Phenothiazine and Some of its Derivatives on the Determination of 5-Hydroxyincioleacetic Acid in Urine
Authors: Ross George , Weinstein I Bernard , Kabakow Bernard
Published: January 2020

The experimental work in this paper demonstrates that derivatives of phenothiazine interfere with the chemical determination of 5-HIAA. This holds true when attempts are made to determine 5-HIAA in the presence of Compazine, Sparine, Phenergan or chlorpromazine, and in the case of the latter substance also when administered to a patient. Thus, it is impossible by the chemical method to determine 5-HIAA in the urine under these circumstances, and results so obtained will be incorrect. However, with the chromatographic method of Curzon (7) no such interference occurs, and, utilizing this technic, it is possible to determine 5-HIAA in the urine of a patient while he is receiving chlorpromazine. In this manner it was shown that the urinary excretion of 5-HIAA in a patient with metastatic carcinoid was not influenced by the administration of chlorpromazine. (See ADDENDUM, p. 76.)
Electrometric Method for the Determination of Chloride in Serum and Other Biologic Fluids
Authors: Seligson David , McCormick Gerald J , Sleeman Kenneth
Published: January 2020

A direct titration procedure for chloride in serum, spinal fluid, urine, and other biologic materials has been described. It can be applied to tissues. It is recommended for its accuracy, precision, speed, and versatility.
Serum Iron Determinations
Authors: Rosenthal Harold L , Pfluke Mari Lou , Jud Lois
Published: January 2020

The inclusion of control serum samples for the estimation of serum iron by the Kingsley-Getchell bathophenanthroline and the Ramsay dipyridyl methods is necessary in order to correct for nonspecific absorption of serum pigments. In the absence of control samples, serum iron concentration may be from 25 to 90 per cent too high.
Rapid Test for Detection of Certain Iodine-Containing Contaminants in Serum
Authors: Grossmann Alfred , Grossmann Grace F
Published: January 2020

A method has been proposed for detecting sera of iodine content of 500 µg. per 100 ml., or higher. When using incineration procedures for the analysis of PBI, samples containing large amounts of iodine may cause the contamination of other specimens, and invalidate the entire run. The high-iodine detection test reported here has also been found useful, under certain conditions, for rapid, semiquantitative iodine assay.
Changes in the Erythrocyte Potassium in Patients with Cardiac Failure Treated with Digitalis
Authors: Clifford Thomas C , Beautyman William
Published: January 2020

The erythrocyte potassium shows a marked and statistically highly significant tendency to fall when patients with cardiac failure are treated with digitalis. In the small series reported here there appears to be a correlation between clinical response and the fall of erythrocyte potassium. It is suggested that the determination of the erythrocyte potassium may be of value in the management of such cases.
Microbiologic Determination of Codehydrogenase in Blood of Patients with Ulcerative Lesions
Authors: Caspe Saul , Pitcoff Daniel D
Published: January 2020

A microbiologic determination of codehydrogenase by means of H. parainfluenzae is presented. Data on the blood enzyme concentration of patients suffering from leukemia, diabetes, and duodenal ulcer are given.
The Stability of Lactic Dehydrogenase in Serum
Authors: Lazaroni J A , Maier E C , Gorczyca Leonard R
Published: January 2020

The stability of lactic dehydrogenase was demonstrated at temperatures of 25° and 37°. The enzyme, in 80 per cent of the cases, was stable for at least eight days at room temperature and seven days at 37°. Bacterial contamination may have caused an alteration in one case.

For purposes of transportation, specimens can be handled safely without any special packaging or preservation.
The Assay of Urinary Peptides Using a Biuret Reagent
Authors: Balikov Bernard , Lozano Eloy R , Castello Robert A
Published: January 2020

The components of a biuret reagent have been investigated to minimize variations in readings resulting from small variations in composition. When this biuret reagent is used for the assay of urinary peptides, readings should be made at 405 mµ. There is a limited but adequate straight-line relationship between concentration and absorbance on normal urine. Urine from convalescing burn patients containing normal concentrations of peptides may read 10-20 per cent low.

This method has a coefficient of variation of 1.68 per cent. Under ordinary circumstances there will be no interference from oxalic acid, creatinine, uric acid, ammonia, or hippuric acid. Amino acids and glucose may result in false elevations of readings. Samples must be preserved by refrigeration or with toluene or thymol, and when so treated are stable up to 48 hours for peptide assay.
Evaluation of Glucose Determinations in Untreated Serum Samples
Authors: Weissman Milton , Klein Bernard
Published: January 2020

Serum without the use of an antiglycolytic agent is inadequate for glucose determinations unless the delay between collection and processing is minimum. Fluoride-treated samples should be used when delay of an hour or more is unavoidable.
A New Method for Starch Gel Electrophoresis of Human Hemoglobins, with Special Reference to the Determination of Hemoglobin A2
Authors: Goldberg C A J
Published: January 2020

A method for starch gel electrophoresis of hemoglobins is presented in which a modified Lintner starch is used for the preparation of the gel. A discontinuous buffer system of tris-EDTA-borate/barbital is used as the electrolyte medium because of its superior resolving power.

Hemoglobin A2 values, obtained with this method, of healthy individuals, patients with thalassemia, and those with various anemias of nonthalassemic origin are presented.
Binding Affinity of Purified Plasma Proteins for Phenethylbiguanide, an Oral Hypoglycemic Compound
Authors: Shepherd Herndon G , McDonald Hugh J
Published: January 2020

A colorimetric method has been adapted to the quantitative determination of the oral hypoglycemic compound phenethylbiguanide. This method was useful in studying the binding affinity of purified bovine plasma albumin and gamma globulin for the hypoglycemic agent. Equilibrium dialysis studies, which measure the decrease in thermodynamic activity of the bound cation, reveal that there is no significant interaction between phenethylbiguanide and the two native proteins. Consequently, the two plasma proteins are assumed to exert no buffering action in controlling the plasma concentration of the drug. The adherence of phenethylbiguanide to Beer's Law indicates that the compound exists in the monomeric state in aqueous solution below 10-4 molar.
Improvement in PBI Method
Authors: Marlow Hubert W
Published: January 2020

This laboratory has been using this method for more than 1 year and the final considered conclusions are:

1. Much time is saved in not having to clarify the solution by centrifugation and/or filtering through fine paper or a cotton plug.

2. Accurate and comparable results are obtained.

3. Time of incineration can be cut from 2½ hours to 2 hours.
Chlorine in Distilled Water as a Source of Laboratory Error
Authors: Caraway Wendell T
Published: January 2020

Some distillation processes may result in the inadvertent contamination of distilled water with free chlorine. One part per million of free chlorine in distilled water has been shown to inhibit markedly the color development in the usual determinations of uric acid and bilirubin. The effect of free chlorine on other clinical chemistry determinations is discussed and simple tests for the detection of free chlorine in water are reviewed.
Blood Lipids in Young and Old Individuals
Authors: Ackermann P G , Toro G , Toro J , Kheim T , Kountz W B
Published: January 2020

We find, then, an increase in cholesterol serum level with age up to about 50 in the males and 60 in the females and decrease with further increase in age to values close to that of young individuals; there is a somewhat similar change in the total fatty acids and a less marked change in the poly-unsaturated fatty acids. The ratio of either the cholesterol or poly-unsaturated acids does not show this change but is relatively constant for the cholesterol and shows a steady decrease with age for the unsaturated fatty acids. The data indicate that ratios are more dependent upon the absolute lipid values than on age per se.
Quantitative Determination of Azure A in Urine
Authors: Klein Bernard , Weissman Milton
Published: January 2020

A rapid, quantitative procedure for the determination of Azure A in urine is presented.
A Modified Method for Determination of Uropepsin
Authors: Arensburger Konstantin E
Published: January 2020

The incorrect high values in the determination of uropepsin results from the color of the original specimen. Evidently incubation changes other substances that are present in the urine and then react with the reagent or otherwise add to the absorbance at the determination wavelength.

The method presented gives results that are considerably closer to correct.

The basic principles involved in the determination of uropepsin by Gray and his associates have not been altered by this modification.
Studies on the Photometric Determination of Phenylpyruvic Acid in Urine
Authors: Saifer Abraham , Harris Alfred F
Published: January 2020

1. At low temperatures and in the absence of light, ferrous ammonium sulfate exerts a stabilizing effect on the reaction between ferric chloride and phenylpyruvic acid. This reaction is not affected by uranyl nitrate, which has been found by us to be an effective precipitant for phosphate when specimens of pathologic urine are being studied.

2. A method for the analysis of phenylpyruvate has been presented and applied to 8 specimens of urine from cases of phenylpyruvic oligophrenia. The method has been shown to possess good reproducibility, stability, and sensitivity.

3. A mechanism has been postulated for the stabilizing effect of ferrous ions involving an equilibrium relationship between the (Fe- PPA) complex, ferrous, and ferric ions. This concept seems to be strengthened by the fact that ferrous ions are continuously produced during the period of growth and decay of the (Fe-PPA) complex.
Variation of pH of Clinical Samples as a Source of Error in Enzyme Determinations
Authors: Henry Richard J , Chiamori Neil
Published: January 2020

Variation of pH of urine and serum samples, either physiologic or that resulting from change on standing, may be a significant source of error in determination of enzyme activity. Buffer systems employed to control pH may be inadequate to cope with the variations which may be encountered. It has been demonstrated that such is the case in the determination of serum alkaline phosphatase by the method of Shinowara, Jones and Reinhart.
A Practical Method for the Determination of Fibrinogen
Authors: Reiner Miriam , Cheung Helen L
Published: January 2020

A practical method for the determination of fibrinogen is presented in which thrombin is used to convert fibrinogen to fibrin and the resultant clot is hydrolyzed. The concentration of protein may be determined by the usual biuret reagent or by the phenol-biuret reagent of Lowry, if small amounts of fibrinogen are to be measured. The mean normal plasma value was found to be 295 ± 17.0 mg./100ml.

Albumin or serum may be used instead of fibrinogen as a more convenient protein standard.
Micro Methods for the Determination of Chylomicron Counts, Fatty Esters, Lipid Phosphorus, and Cholesterol in Blood Serum
Authors: Clayton Mary M , Adams Patricia A , Mahoney Gisela B , Randall Shirley W , Schwartz Eleanore T
Published: January 2020

The procedures described make it possible to determine chylomicron counts and one of the other lipid constituents on approximately 100 µl. of blood serum. In general, the technics used are those of Bessey and Lowry. Chylomicron counts are determined by a modification of the method of Becker, Meyer, and Necheles. Dilutions of high count serum are made with fasting serum and a correction made for the chylomicrons in the diluting serum.

In each of the chemical mehods, 75 µl. of blood serum is used and the lipids completely extracted from the serum with alcohol-ether mixture. The method for fatty esters is an adaptation of the methods of Hill, and Bauer and Hirsch and involves the formation of a lavender-colored complex of ferric hydroxamate on the addition of an acidified solution of alcoholic ferric perchlorate. The method for lipid phosphorus is an adaptation of the macro method described by Hawk, Oser, and Summerson. The extracted lipids are oxidized with sulphuric acid and hydrogen peroxide and the phosphate present determined by the Fiske and Subbarow method. The method for cholesterol is an adaptation of the methods of Kibrick, et al. and Abel, et al. It involves the hydrolysis of cholesterol esters with 17% benzyl trimethylammonium hydroxide during the evaporation of the alcohol-ether extract and the use of the residue directly for the development of a green color by the Liebermann-Burchard reaction.

The average fasting value for fatty esters obtained for 12 normal weight college women was 414 mg. per 100 ml., expressed as tripalmitin. For lipid phosphorus the average fasting value obtained for 8 normal weight college women was 7.8 mg. per 100 ml. The average fasting cholesterol value obtained for 16 normal weight college women was 154.8 mg. per 100 ml. The average value for 6 normal weight older women (ages 37-63) was 257.2 mg. per 100 ml.
Glucose Determination by Automatic Chemical Analysis
Authors: Grady Harold J , Lamar Martha A
Published: January 2020

A method of automatic chemical analysis has been improved by stabilizing the temperature of the dialyzing unit. With this addition the automatic analyzer has been shown to have greater precision and accuracy than a manual method.
A Method for the Routine Determination of Chlorpropamide in Plasma
Authors: Carmichael Ralph H
Published: January 2020

A simple routine method for the colorimetric determination of chlorpropamide in plasma is described. The compound is extracted from acidified plasma with isoamyl acetate and decomposed by heating. The 2,4-dinitrophenyl derivative of the resulting amine is formed and measured colorimetrically.
Rapid Semimicro Procedure for Estimating Free and Total Cholesterol
Authors: Courchaine Armand J , Miller William H , Stein Donald B
Published: January 2020

A rapid procedure for the determination of both free and total cholesterol in serum is described. The color development is extremely rapid, and once fully developed the color remains stable for several hours. The heat of reaction produced by the combination of concentrated sulfuric acid, phosphoricacid, and glacial acetic acid is apparently responsible for the rapid color development. The stable ferric chloride reagent containingphosphoric acid appears to be the contributing factor to the stability of the color. The results obtained with this procedure compare favorably with those obtained with saponification methods.
A Rapid Screening Method for the Elimination of Cross-Contamination in the Determination of Protein-Bound Iodine
Authors: Ackerman John A , Myers John T
Published: January 2020

The described method should be of value as a rapid Screening process to eliminate serum containing a nonphysiologic high amount of iodine, thereby preventing contamination of other samples in the ashing oven. The advantage over other published methods is that it does not require special reagents or special equipment. The sensitivity is in the range of 300-400 µg. and total time required about 15-20 minutes.
A Rapid Complexometric Titration of Serum Calcium
Authors: McAllister H C , Yarbro C L
Published: January 2020

The procedure of Yarbro and Golby (2) for the determination of urinary calcium has been modified for use in determining serum calcium on 0.2 to 2 ml. of serum. Ferrous iron in concentrations that might be expected in serum from partially hemolyzed blood does riot interfere. Variation among calcium determinations on replicate samples of serum was within ±4 per cent, and recoveries of calcium added to serum ranged from 94 to 103 per cent. An individual determination of serum calcium by this procedure requires 3-5 minutes.
A Micromethod for the Determination of Plasma Amylase
Authors: Marsters Roger W , Kinney Thomas D , Lin Ku Yin
Published: January 2020

A micromethod for the determination of serum amylase has been presented, which is useful in pediatric practice and in experimental work on small animals. The optimum conditions for the procedure have been studied and the data obtained recorded.
Effect of Orally Administered Quinine and Quinidine on Apparent Values for Urinary Catecholamines
Authors: Sax Sylvan M , Waxman Harold E , Aarons Jerome H , Lynch Harry J
Published: January 2020

The oral administration of quinine and quinidine results in an apparently increased excretion of catecholamines, the effect being greater following quinine. Marked similarity exists in the fluorescence behavior of postquinine and postquinidine eluates and solutions of the model compound 6-methoxy-4-methylcarbostyril. The possibility that quinine and quinidine carbostyrils are responsible for the observed interference is discussed.