bluuebunny/crossref_metadata_2025_split huggingface dataset:
Parathyroid Hormone Assay in Primary Hyperparathyroidism: Experiences with a Radioimmunoassay Based on Commercially Available Reagents
Authors: Kleerekoper M , Ingham J P , McCarthy S W , Posen S 
Published: January 2020

Abstract
A radioimmunoassay is described for parathyroid hormone in human serum, in which commercially available reagents are used almost exclusively. This assay can be done by any laboratory with experience in radloimmunoassay. Thirty-two of thirty-three patients with surgically proven primary hyperparathyroidism had detectable concentrations of parathyroid hormone in their serum, and concentrations of the hormone exceeded the normal range in 24 of them. Significant positive correlations were found between pre-operative serum calcium, pre-operative serum parathyroid hormone, and the weight of parathyroid tissue removed at operation. These three parameters were also significantly correlated with severity of the skeletal changes as assessed by semiquantitative histological methods.
Kinetic Determination of Total Serum Protein with a Centrifugal Analyzer
Authors: Koch Thomas R , Johnson George F , Chilcote Max E 
Published: January 2020

Abstract
A kinetic biuret assay of total serum protein on the "CentrifiChem" centrifugal analyzer is shown to be rapid, accurate, and reasonably precise, and accommodates the most desirable analytical method and standardization currently available. Kinetic analysis of compounds undergoing first-order reactions is a useful type of analysis that is of significant advantage to the clinical laboratory.
Design and Performance of a Miniaturized High-Speed Continuous-Flow Analyzer
Authors: Neeley William E , Wardlaw Stephen C , Sing Helen C 
Published: January 2020

Abstract
Design features and performance of a miniaturized high-speed continuous-flow analyzer are described. Special emphasis is made in the design towards a system that is free from the operational and mechanical complexities found in most of today’s advanced systems. Depending on the particular analyses, sample size varies from 3 to 25 µl and reagent consumption is less than 180 µl per sample. Analyses are performed under steady-state conditions at sampling rates of 150 samples per hour with a 2:1 or 3:1 sample-to-wash ratio. The marked reduction in sample size makes the system ideal for microanalyses, especially in the pediatric clinical laboratory, in small animal research, and in any other cases where small sample volume is especially important.
Comparison of Four Indexes to Fetal Pulmonary Maturity
Authors: Rosenthal Arthur F , Vargas Marta G , Schiff Selma V 
Published: January 2020

Abstract
With use of the same amniotic fluid specimens, lecithin concentration was compared with nonchromatographically determined glycerophospholipid, total lipid phosphorus, and the bubble-stability test as indexes of fetal lung maturation. The lecithin analysis was performed by thin-layer chromatography, with use of a semiautomated method of spotting and nondigestive release of phosphorus from the separated spots. We conclude that, next to the chromatographic analysis, the best tests are glycerophosphatide P, the bubble-stability test, and total lipid P, in that descending order. Lecithin determination as compared with densitometric evaluation of the lecithin/sphingomyelin ratio is discussed.
Optimal α-Oxobutyrate Concentration for Assay of α-Hydroxybutyrate Dehydrogenase Activity in Normal and Pathological Sera at 30 °C
Authors: Shaw Leslie M , Gray Jane 
Published: January 2020

Abstract
Optimal concentration of substrate, α-oxobutyrate, for determination of α-hydroxybutyrate dehydrogenase (HBD) activity in normal and pathological sera at 30 °C (with a centrifugal analyzer) is 12 mmol/ liter. With this substrate concentration, HBD activity averaged 146% of that found with the suboptimal concentration, 3.3 mmol/liter, usually used. Furthermore, day-to-day precision was significantly better. HBD/LD ranges (LD, lactate dehydrogenase), determined for sera from patients with myocardial infarction and liver disease, did not overlap and were similar to those established by Elliot et al. [Clin. Sci. 23, 305 (1962)], who used a suboptimal α-oxobutyrate concentration of 3.3 mmol/liter at 25 °C. At 30 °C the mean HBD/LD ratios for sera from patients with myocardial infarction were most different from those for patients with liver disease when the optimal concentration of α-oxobutyrate was used.
Effect of Venous Occlusion of the Arm on the Concentration of Calcium in Serum, and Methods for its Compensation
Authors: Husdan Harry , Rapoport Abraham , Locke Sandra , Oreopoulos Dimitrios 
Published: January 2020

Abstract
Data are presented on the effects on 12 normal subjects of a 3-min period of venous occlusion of the arm. Concentrations of both total calcium and total protein in serum are significantly increased, while serum magnesium and phosphorus and plasma ionic calcium concentrations remain unchanged. Concentrations of both total calcium and total protein are significantly greater in the serum of men than of women. The use of methods of adjusting calcium for changes in total protein concentration, as devised by Dent and by Parfitt, eliminate changes in these values because of venous occlusion and sex-related differences. Normal ranges for serum total calcium adjusted according to these methods are based on findings in 87 normal subjects (43 men and 44 women). The clinical usefulness of such adjustments in serum calcium measurements is discussed.
Rapid, Accurate Technique for Determination of Carbon Monoxide in Blood
Authors: Dahms Thomas E , Horvath Steven M 
Published: January 2020

Abstract
We report a chromatographic technique in which a vortex method of gas extraction and a thermal conductivity detector are used to measure carbon monoxide in blood. This method has the advantages of a small sample volume (100 µl), a rapid analysis time (3 min), ease of operation, and a high correlation with results of the standard gasometric method over the entire possible range (r = 0.999). The accuracy of this method (coefficient of variation) for measuring CO in human blood samples was 1.7%. With it, dissolved CO can be accurately measured, as demonstrated by the Bunsen solubility coefficient for plasma CO by this method of 22.0 ml of CO per liter of water per atm. (101 kN/m2) at 24 °C (theoretical value: 21.8).
Column-Chromatographic Studies of Isoamylases in Human Serum, Urine, and Milk
Authors: Fridhandler Louis , Berk J Edward , Montgomery Katherine A , Wong Deborah 
Published: January 2020

Abstract
Pancreatic and salivary isoamylases not discerned by a chromatographic method previously described have been detected by a modification of that method. Detailed analysis of the nature of these isoamylases and their distribution showed that the pancreatic type (P-type) and salivary type (S-type) isoamylases in pancreatic extract and saliva appear in normal urine along with an isoamylase of unknown origin (X-type). Normal serum could not be similarly studied because of the low amylase activity in such serum. However, the X-type isoamylase fraction was found in three hyperamylasemic sera, including one from a patient with lung carcinoma who produced S-type amylase. Study of 25 samples of human milk revealed high amylase activity and no detectable P-type; S-type components were found along with the X-type component. Parallel patterns of variation were found in human milk in two patients studied for six months postpartum. Salivary amylase and the S-type amylase in milk and in the serum of the patient with lung carcinoma and marked hyperamylasemia appeared to be similar, and may be identical.
Analysis for Total Serum Thyroxine by Equilibrium Competitive Protein Binding on Small, Re-usable Sephadex Columns
Authors: Alexander Nicholas M , Jennings James F 
Published: January 2020

Abstract
We describe a modified method of analysis for total thyroxine in 50 µl of serum by equilibrium competitive protein binding with thyroxine-binding globulin. Columns (9 x 23 mm) are used containing Sephadex G-25, which are regenerated after each cycle by removing residual thyroxine adsorbed to the gel with excess thyroxine-binding globulin (dilute plasma). As little as 1 ng of hormone can be detected, and recoveries of added thyroxine from sera range from 98-102%. For either between-assay or within-assay determinations, the coefficients of variation are about 4%. Results of this method as compared with those for the uncorrected Murphy-Pattee procedure [J. Lab. Clin. Med. 66, 161 (1965)] gave a correlation coefficient of 0.944, but results with the present procedure are 11% higher because of incomplete and variable recovery with the uncorrected Murphy-Pattee method. Our procedure offers the advantage that, on a single column, thyroxine is quantitatively extracted from serum, rapidly brought to equilibrium binding with thyroxine binding globulin, and the free and bound thyroxine are separated. Cumbersome and lengthy procedures of extraction, centrifugation, and evaporation are thus obviated.
New Method for Measurement of Guanidinosuccinic Acid in Serum and Urine
Authors: Gróf J , Tankó A , Menyhárt J 
Published: January 2020

Abstract
We describe a new method for measurement of guanidinosuccinate in serum and urine. To separate it from interfering guanidino compounds, it is adsorbed on and eluted from an anion-exchange column. The modified method requires less serum and is considerably faster than previous ones.
Screening Cord Bloods for Detection of Sickle Cell Disease in Jamaica
Authors: Serjeant Beryl E , Forbes Miriam , Williams Leslie L , Serjeant Graham R 
Published: January 2020

Abstract
A cord-blood screening program, designed primarily for detecting sickle cell disease, has been in operation for seven months (8000 samples) at a large maternity unit in Kingston, Jamaica. We describe techniques of cord-blood collection and electrophoretic investigation on both cellulose acetate and agar gel. These methods appear to give rapid, valid results at minimal expense and are well adapted to screening large populations.
Standard Reference Materials 933 and 934: The National Bureau of Standards' Precision Thermometers for the Clinical Laboratory
Authors: Mangum B W 
Published: January 2020

Abstract
Because many facets of clinical laboratory work, such as enzymatic reactions, pH measurements, and blood-gas analysis, are highly sensitive to temperature, there is a need to measure temperature accurately and closely control it. To help satisfy these needs and to aid in getting a usable temperature scale into the clinical laboratory, the National Bureau of Standards has developed SRM 933 and SRM 934. These precision thermometers are calibrated at 0, 25, 30, and 37 °C. Their value to the clinical laboratory is described.
Plasma Corticotropin Radioimmunoassay, with Use of Fuller's Earth for Extraction
Authors: Horgan E D , Riley W J 
Published: January 2020

Abstract
A radioimmunoassay is described for plasma corticotropin whereby concentrations over the range of 6 to 1000 ng/liter can be measured. Corticotropin extracted from plasma on fuller's earth under carefully standardized conditions is assayed by a long-used double antibody radioimmunoassay procedure. Within (n = 6) and between (n = 12) assay precision is 39 ± 2 (SD) ng/liter and 44 ± 6 (SD) ng/liter, respectively. Normal basal corticotropin concentrations in plasma collected between 8 a.m. and 10 a.m. ranged from 6 to 68 ng/liter. Corticotropin was not detected in hypophysectomized patients and in subjects pretreated with dexamethasone, but elevated concentrations were found in an Addisonian patient and in a patient with a thymoma.
Contamination of Distilled Water, HCl, and NH4OH with Amino Acids, Proteins, and Bacteria
Authors: Hamilton Paul B , Myoda T Timothy 
Published: January 2020

Abstract
Contamination of distilled water with free and bound amino acids and with microbes has been overlooked in most laboratories. Unless special precautions are taken, distilled water will be contaminated with air borne microbes, probably psuedomonads, which multiply in water of conductivity quality. Amino acids and proteins that may be found in the water therefore presumably are derived from these airborne organisms. Chemical reagents such as hydrochloric acid and ammonium hydroxide solutions, which have water as an integral part, also have been found to be contaminated with amino acids. This paper deals with the extent of such contamination and describes means to provide water and hydrochloric acid (6 mol/liter) that would be suitable for determination of amino acids in concentrations of 10-9 mol/liter or less in materials of biological interest as well as rocks, lunar soil, meteorites, etc.
Factors Influencing the Quality of Analytical Methods— A Systems Analysis, with Use of Computer Simulation
Authors: Aronsson Torsten , de Verdier Carl-Henric , Groth Torgny 
Published: January 2020

Abstract
A systems analysis was performed, to evaluate the influence of various types of systematic and random errors that are characteristic of the analytical procedure proper and the calibration procedure for an analytical method. For this purpose, a simulation procedure was devised describing the effect on the analytical result of factors such as number and precision of calibration samples (standards) in a given segment of the analytical series, concentration range of the calibration samples, approximation of a curved characteristic function to a straight line, base-line and sensitivity drift, contamination, and different types of correction for drift and contamination. The systems analysis showed that the total error of an analytical method not only depends on the inherent random error of the analytical procedure but is also strongly influenced by the factors mentioned. We conclude that the simulation procedure is a valuable tool for minimizing the effect of these factors and for designing an analytical series that is optimal with respect to existing conditions.
Criteria for Judging Precision and Accuracy in Method Development and Evaluation
Authors: Westgard James O , Carey R Neill , Wold Svante 
Published: January 2020

Abstract
We describe an approach for formulating criteria that can be used to judge whether an analytical method has acceptable precision and accuracy. We derive criteria for several experiments that are commonly used in method-evaluation studies: precision or replicates, recovery, interference, and comparison of patient values between the new method and a proven method. These criteria are based on the medical usefulness of the test results, thus the acceptability of the method is judged with respect to the clinical requirements.
Electrophoretic Demonstration of Three Extra Lactate Dehydrogenase Isoenzymes in the Serum of a "Normal" Individual
Authors: Papadopoulos N M 
Published: January 2020

Abstract
A clinically asymptomatic individual with normal total serum lactate dehydrogenase activity had an electrophoretically abnormal serum pattern for lactate dehydrogenase isoenzymes, eight isoenzyme bands being present.
Kinetics of the IgG—anti-IgG Reaction, as Evaluated by Conventional and Stopped-Flow Nephelometry
Authors: Savory John , Buffone Gregory , Reich Richard 
Published: January 2020

Abstract
A stopped-flow spectrophotofluorometer equipped with a data-acquisition system was used to study the rate of formation of IgG—anti-IgG complexes by nephelometry. Light-scattering aggregates could be detected within 100 ms. Early rates ( 0-3 s) increased with antigen concentration, while rates during later stages (5-100 s) followed the same trend exhibited by the precipitin curve. Polyethylene glycol (known to exert a profound effect on antigen—antibody reactions) at a concentration of 40 g/liter affected the IgG—anti-IgG reaction as follows: there was an initial lag phase of 5-10 s and a subsequent rapid reaction over the next 20-40 s, characterized by a four-to five-fold enhancement in the amount of light scattered. Our observations demonstrate that centrifugal-analyzer techniques can be used for the kinetic measurement of specific proteins in serum.
DNA Cytophotometry of Chromosomes in a Case of Chronic Myelogenous Leukemia
Authors: Mayall Brian H , Carrano Anthony V , Rowley Janet D 
Published: January 2020

Abstract
The DNA-stain content of human metaphase chromosomes is measured by use of quantitative cytochemistry, scanning cytophotometry, and image-processing techniques. This approach is applied to chromosomes from a female with chronic myelogenous leukemia. Measurements are normalized for each cell and expressed on a scale by which the sum of the measurements for the 44 autosomal chromosomes is 100 units; the normalized measurements are compared with standard values from eight normal persons. Banding analysis of the leukemic cells shows a 9q+/22qtranslocation. This is confirmed by the DNA measurements; 0.42 units are involved. In addition, measurements of both leukemic and nonleukemic cells reveal a 9+/20-translocation that cannot be detected visually; 0.12 units are involved. Neither translocation shows a net loss of DNA; any loss exceeding 0.05 units (6 x 106 base pairs of DNA) would be significant (P &lt; 0.05). These results illustrate the power of this approach and bear on the etiology of chronic myelogenous leukemia.
Acetaminophen Metabolism in Man, as Determined by High-Resolution Liquid Chromatography
Authors: Mrochek J E , Katz S , Christie W H , Dinsmore S R 
Published: January 2020

Abstract
Acetaminophen is a commonly used analgesic, available without prescription. Several of its metabolites have heretofore been isolated from physiologic fluids and analytically characterized. In general, the separation methods are complicated, usually requiring extensive sample pretreatment, and do not measure the individual conjugated metabolites. High-resolution anionexchange separation of urinary samples from subjects receiving acetaminophen reveals eight chromatographic peaks, representing seven metabolites and the free drug itself. Metabolites separated include 2-methoxyacetaminophen, its glucuronide and sulfate conjugates, the sulfate conjugate of 2-hydroxyacetaminophen, the glucuronide and sulfate conjugates of acetaminophen, S-(5-acetamido-2-hydroxyphenyl)cysteine, and S-(5-acetamido-2-glucuronosidophenyl)cysteine. Urinary and serum concentrations of the drug and its seven metabolites were determined by high-resolution liquid chromatography as a function of time after two clinically normal men ingested 1950 mg of the drug. Concentrations in urine and serum are compared, and estimated urinary excretion rates are reported for all metabolites except S-(5-acetamido-2-hydroxyphenyl)cysteine. Serum concentrations of the glucuronide were higher than concentrations of the free drug 2 h after the drug was ingested, indicating that solvent-extraction procedures for serum will yield low estimates of total drug unless hydrolysis precedes the extraction step.
Incorporation of a High-Speed Decimal Data Processor into a Centrifugal Analyzer
Authors: Gregory R P , Avery J , Renoe B W , Dryden P C , Malmstadt H V 
Published: January 2020

Abstract
We incorporated a new high-speed data processor into a centrifugal analyzer system. The data processor is compact and inexpensive, yet it is capable of performing the essential control and data-manipulation functions that are usually performed by a minicomputer. The ease with which the system can be programmed to perform a typical analytical procedure is illustrated. The interaction of system components during the analysis is described, with emphasis on the role of the processor. Analytical results are presented.
Breath Analysis as a Technique in Clinical Chemistry
Authors: Dubowski Kurt M 
Published: January 2020

Abstract
Breath possesses unique advantages as a specimen for clinical chemical analyses, including the continuous equilibrium of gases and volatile substances between expired alveolar air and the pulmonary blood circulation. Substances amenable to analysis in breath include O2, CO2, CO, and other gases, volatile organic compounds, and many drugs with sufficiently high vapor pressures at physiological temperatures. Practical aspects of breath sampling and breath analysis are discussed, exemplified by breath-alcohol analysis. The requirements for obtaining breath samples in equilibrium with the pulmonary blood circulation are delineated, and experimental data are presented for the significant breath-sample characteristics bearing on design of breath collection and storage systems (end-expiratory temperature, breath volumes).
Electrochemical Detection of Selected Organic Components in the Eluate from High-Performance Liquid-Chromatography
Authors: Kissinger Peter T , Felice Lawrence J , Riggin Ralph M , Pachla Lawrence A , Wenke David C 
Published: January 2020

Abstract
High-performance liquid chromatography can be combined with hydrodynamic thin-layer electrochemistry for determination of trace amounts of organic constituents in complex samples. With small and inexpensive analyzers based on these two techniques, as little as 1 pg of an electrochemically active component can be detected in a few minutes. Because many of the important low-molecular-weight organic constituents of body fluids— both endogenous metabolites and drugs—undergo electrochemical reactions, it seems reasonable to presume that useful assays might be developed by using the above methodology. Beginning to explore this presumption, we illustrate how uric acid, ascorbic acid, catecholamines, and related tyrosine metabolites might be measured in urine and serum. In some cases, liquid chromatography with electrochemical detection provides better sensitivity, selectivity, and speed than traditional methods, while minimizing the need for analytical reagents. We describe the basic approach and progress to date and suggest future applications.
Contribution of Blood Phosphate Esters to the Blood Saccharoid Fraction of Rats with Alloxan-induced Diabetes or Treated with Insulin or Epinephrine
Authors: un-Nisa Zeenat- , Rahman M Ataur 
Published: January 2020

Abstract
Nonglucose reducing substances in blood constitute the "saccharoid fraction," which increases both in hyperand hypoglycemia. The phosphate esters, including weak-acid phosphates and fructose-1,6-diphosphate, constitute 14 to 25% of the saccharoid fraction in whole blood, 2 to 9% in plasma, and 24 to 35% in erythrocytes of normal rats treated with insulin or epinephrine and of alloxan diabetic rats treated with insulin. Glutathione, glucuronic acid, ascorbic acid, uric acid, and creatinine (reported earlier) and the phosphate esters (reported here) altogether account for 75 to 100% of the saccharoid fraction under the experimental conditions used, except in the alloxan-diabetic rats, where on the fourth day of alloxan treatment a larger proportion was unaccounted for. The dynamic character of the saccharoid fraction is probably due to the evanescent nature of these phosphate esters.
Determination of Short-Chain Fatty Acids in Stool Ultrafiltrate and Urine
Authors: Collin Dennis P , McCormick Patrick G 
Published: January 2020

Abstract
A new method is reported for determining total shortchain fatty acids in stool water and urine. The method uses ion-exchange resins to remove interfering substances, and determines these acids by direct titration. Lactic acid, if present, is determined along with the short-chain (C1-C6) organic acids. Interferences such as carbonate, phosphate, creatinine, bile acids, and uric acid are removed by the ion-exchange treatment. Values obtained by this simplified technique correlate very well with those by gas-chromatographic analyses of the same sample, and the method represents a significant improvement over the Van Slyke technique.
Alpha- and Beta-Lipoprotein Cholesterol
Authors: Nury F S , Smith Elizabeth R B 
Published: January 2020

Abstract
The procedure of Langan, Durrum, and Jencks (1) for the estimation of serum α- and β-lipoprotein cholesterol has been simplified, and the time required for an analysis greatly reduced.
The present method can be used for the rapid measurement of total serum cholesterol as well as for distribution between α- and β-lipoproteins.