bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

Abstract
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 &lt;6 mg/liter, the automated method of Lauwerys et al. gave slightly higher results than did the chromatographic methods. At concentrations &gt;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 (&lt;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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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.
Determination of Vitamin B12 With an Escherichia Coli Mutant
Authors: Aronovitch J , Grossowicz Nathan 
Published: January 2020

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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.