bluuebunny/crossref_metadata_2025_split huggingface dataset:
Serum Thyroxine: Results Compared for a Commercial Radioimmunoassay and a Commercial Competitive Protein Binding Analysis
Authors: Kubasik Norman P , Sine H E , Murray Martin H 
Published: January 2020

Abstract
Two commercial isotopic methods for measuring serum thyroxine—radioimmunoassay and competitive protein binding analysis—have been compared with regard to recovery of thyroxine added to sera, within-run and run-to-run reproducibility, and results for patients’ sera. For the latter the relationship is expressed by the equation CPBA = 082 RIA + 0.33. The correlation coefficient was 0.92.
Counting of Beta and Gamma Emitters Used in Clinical Radioimmunoassays and Competitive-Binding Assays by Liquid Scintillation Counters
Authors: Helman Edith Zak , Ting Philip 
Published: January 2020

Abstract
Although liquid scintillation (LS) counters were originally designed to count low-energy beta emitting isotopes, they can also be used to count gamma emitters used in radioimmunoassay. This is made possible by placing the gamma emitter inside a "Microfuge" tube suspended from a LS vial cap into a scintillator fluid containing an electron density increaser. Efficiencies of 71% are obtained for 125I by this method, comparable to that obtained with Nal (TI) crystal gamma counters. Efficiencies for other clinically important isotopes used in radioimmunoassay—131I, 57Co, 60Co, 51Cr, 59Fe—by the Microfuge method are 15-19%; therefore, for these isotopes a LS "Mini-Vial" method is suggested, in which smaller volumes may be used. The dual capability of LS counters to count both beta and gamma emitters extends its usefulness in the clinical laboratory.
Simple Radioimmunoassay of Five Unconjugated Ovarian Steroids in a Single Sample of Serum or Plasma
Authors: Powell John E , Stevens Vernon C 
Published: January 2020

Abstract
A simplified radioimmunoassay procedure is described for determination of free ovarian steroids in plasma or serum. Ether extracts were chromatographed on a Sephadex LH-20 column equilibrated with benzene—methanol (85:15 by vol) and estrone, estradiol, estriol, progesterone, and 17α-hydroxyprogesterone were resolved from each other. With relatively specific antibodies, all five hormones were specifically assayed directly after the single chromatographic procedure. Procedures for additional purification are described when specific antibodies are not available. A mechanized chromatographic apparatus was used to purify 12 serum extracts simultaneously, permitting up to 120 determinations per day by a single worker. Assay reliability criteria were satisfactory for all assay systems, and steroid values obtained from subjects in different physiological states agreed with previously reported concentrations.
Australia Antigen Content of Commercial Quality-Control Sera
Authors: Simon R G , Langhofer L A , Hendricks E J 
Published: January 2020

Abstract
Australia Antigen (HB Ag) content of 30 chemistry control sera and six other control sera was determined by radioimmunoassay. 23 of the 36 sera were found to be strongly HB Ag positive. We conclude that greater than normal care must be exercised in handling these serums and that better methods must be used to prepare control serum.
Additional Observations on Hydrochlorothiazide Interference with Measurement of Total Urinary Placental Estrogens
Authors: Acosta A Arnaldo , Madeira Linda B , Besch Paige K , Buttram Veasy C 
Published: January 2020

Abstract
The diuretic, hydrochlorothiazide, which enjoys widespread clinical use, decreases the apparent assay values for total urinary estrogens by directly interfering with formation of the Kober chromogen. Urine from patients receiving this medication may give a falsely low total estrogen value. Chlorothiazide, a closely related diuretic, does not so interfere.
Some Drugs and Other Substances That Interfere with Protein Determination
Authors: Pashley D H , Schuster G S , Palmer P , Sharawy M M 
Published: January 2020

Abstract
We show that a variety of substances may interfere positively, to different extents, with the determination of protein by either the Lowry procedure or absorbance at 280 nm, or both. Some of these substances may interfere in concentrations that could be present in clinical laboratory specimens or in research samples.
Modified Glucose Oxidase Method for Determination of Glucose in Whole Blood
Authors: Meites Samuel , Saniel-Banrey Karen 
Published: January 2020

Abstract
We have modified an ultramicro method for determining glucose with glucose oxidase—peroxidase—odianisidine. Capillary blood is diluted in isotonic NaF (17.6-17.8 g/ liter), the cells are removed, and glucose is determined after a 20-min incubation with enzyme-containing reagent. Increasing the enzyme concentration fourfold nullifies interference from ascorbic acid and hemolysis, while greatly decreasing interference from bilirubinemia. If necessary, bilirubin is removed completely by coprecipitation with protein. Interference from uric acid is minimized by incorporating it into the standards. Several other suspected interferences proved inconsequential. Isotonic NaF does not inhibit the enzymes used, and preserves glucose in blood for at least 2 h. Avoiding protein precipitation and shortening the incubating time significantly lessens analytical time without affecting precision.
An Approach to the Measurement of Total Lipid Glycerol in Serum
Authors: Horney Donald L 
Published: January 2020

Abstract
Serum phospholipids that derive from glycerol are hydrolyzed to diglycerides and by-products in the presence of phospholipase C (phosphatidylcholine cholinephosphohydrolase, EC 3.1.4.3). The diglycerides produced are saponified, together with the triglycerides present, to glycerol and salts of fatty acids. Measuring the glycerol produced yields a measure of the total lipid glycerol in serum, and is useful for the estimation of the phospholipid and total lipid content of serum.
Biochemical Properties of Human Prostatic Acid Phosphatase
Authors: Lam K W , Li Olivia , Li C Y , Yam L T 
Published: January 2020

Abstract
The electrophoretic pattern (in polyacrylamide gel) for acid phosphatases in the prostate gland was compared with that for other tissues. Isoenzyme 2 predominates in the prostate. The isoenzyme was isolated from the prostate and its biochemical properties were compared with those of acid phosphatases isolated from spleen. Isoenzyme 2 has a molecular weight of about 100,000. Its optimum pH is between 5 and 7, unlike other lysosomal enzymes. Its substrate specificity is not very much different from those of the most active isoenzymes of acid phosphatase in other tissues. Our results contraindicate the use of a specific substrate in the analysis of prostatic acid phosphatases. Determination of the isoenzyme pattern is a new approach in the specific analysis of prostatic acid phosphatases.
Accurate Micromethod for Estimation of Both Medium- and Long-Chain Fatty Acids and Triglycerides in Fecal Fat
Authors: Massion Charles G , McNeely Michael D 
Published: January 2020

Abstract
An accurate, precise photometric assay has been developed for both medium-chain and long-chain fatty acids and triglycerides, in which very small aliquots of fecal emulsion are used. Feces are collected in a paint can and agitated on a commercial paint-can shaker. Homogenization is improved by substituting isopropanol for ethanol and adding bile salts as an emulsifying agent. This collection and processing technique, combined with a spectrophotometric microscale assay, produces a semiclosed system that reduces manipulation of the fecal sample to a minimum, greatly increasing its acceptance by technical personnel. Special glassware is not required and batch processing of samples is convenient. The micromethod of analysis is also readily adaptable to studies of the fecal lipid excretion of small laboratory animals.
Determination of Serum Calcium by Use of an AutoAnalyzer I-II Hybrid
Authors: Jacklyn C L , Freeman C D , Gray M E , MacAulay M A 
Published: January 2020

Abstract
A hybridized system is described for the continuous-flow determination of serum calcium. The analysis is based on the cresolphthalein colorimetric procedure as described for use with the SMA 12/60 (Technicon Corp.). The hydraulic features of the AutoAnalyzer II are used with modules of the AutoAnalyzer I. This combination gives both the ease of operation and hydraulic improvements inherent in the AutoAnalyzer II system and provides an emergency alternative to the SMA 12/60, with which results are shown to be comparable.
An Automated Procedure, with Use of Ferrozine, for Assay of Serum Iron and Total Iron-Binding Capacity
Authors: White J M , Flashka H A 
Published: January 2020

Abstract
In this procedure of analysis for iron in serum and measurement of iron-binding capacity, the Beckman Model 560 DSA and ferrozine are used. The analysis rate is 120 samples per hour. Interferences were investigated and a procedure was devised for masking high concentrations of copper. A modified procedure was used to prepare samples for the assay of total iron-binding capacity. This procedure is more rapid and requires smaller amounts of sample than many methods now in use.
Free Calcium in Serum. II. Rigor of Homeostatic Control, Correlations with Total Serum Calcium, and Review of Data on Patients with Disturbed Calcium Metabolism
Authors: Ladenson Jack H , Bowers George N 
Published: January 2020

Abstract
Two hundred and fifteen measurements of free (ionic) and total calcium were performed on sera from 184 patients in whom some disturbance in calcium metabolism was suspected. The correlation coefficient between free and total calcium was 0.94, but a scattergram indicated that free calcium concentration cannot be predicted from knowledge of total calcium concentration. In "normal" individuals the correlation coefficient was only 0.45. Homeostasis of free and total calcium was examined by making periodic measurements in seven normal individuals over a period of eight months; the variability around the individual’s mean value was 1.2% for free calcium and 1.9% for total calcium. Free calcium, as properly measured by the ion-specific electrode, is a better measure of calcium status than is total calcium in the disease states studied, which were mostly hyperparathyroidism, multiple myeloma, and renal failure.
Measurement of Hexoses and Pentoses, Singly or in Combination, with o-Anisidine
Authors: Goodwin Jesse F , Yee Hugh Y 
Published: January 2020

Abstract
Hexoses and pentoses can be measured either singly or in combination, with an o-anisidine reagent. It has the advantages of a fast reaction rate and relatively little interference from hexoses (Amax = 660 nm) in the measurement of pentoses. A simple subtraction of absorbance attributable to glucose at the maximum for pentoses (465 nm) is sufficient for satisfactory pentose estimation in urine. The method has been automated, and results compare favorably with those from an automated procedure for the measurement of serum glucose in which hexokinase is used, and also with those from a colorimetric aniline method for measurement of pentoses in urine. Interferences and procedural variables are discussed. Urinary pentose and hexose values for normal infants are reported.
Evaluation of an Automated Creatininase Creatinine Procedure
Authors: McLean Monty H , Gallwas Jerry , Hendrixson Mark 
Published: January 2020

Abstract
We have evaluated an automated method for determining serum creatinine by use of the enzyme creatininase. The method has been adapted to the Beckman DSA-560 and measures the Jaffé-positive chromogens present in serum before and after enzymatic hydrolysis of creatinine. The precision and linearity of the method are acceptable, and the results correlate well with those obtained by other accepted techniques. The method offers the advantages of automation, enhanced specificity, micro-scale sample volume, and direct serum analysis.
Principles of Competitive Binding Assays (Saturation Analyses). I. Equilibrium Techniques
Authors: Zettner Alfred 
Published: January 2020

Abstract
The principles of competitive binding assays are reviewed, with emphasis on the differentiation of equilibrium vs. sequential saturation techniques. Three methods of equilibrium analysis are outlined that differ from each other in the relative concentrations of labeled ligand and binder used in the incubation system. The linearization of dose-response curves through the use of the logit plot is discussed. The importance of the knowledge of the effective affinity constant K for optimization of the assays is stressed, and two methods of estimating K are demonstrated with a digoxin-antidigoxin-antiserum system.
Semiautomated Method for Analysis of 11-Deoxy-17-Oxo Steroids in Urine. A Preliminary Report
Authors: Moore John W 
Published: January 2020

Abstract
A method is described for the automated analysis of urinary 11-deoxy-17-oxo steroids from hydrolyzed conjugate extracts. Steroid conjugates are extracted manually on an Amberlite XAD-2 column and hydrolyzed with β-glucuronidase at 62°C for 90 min. After addition of alkali, the samples are transferred to the AutoAnalyzer where the steroids are extracted into isooctane and estimated colorimetrically by a modified Zimmerman reaction.
Radioimmunoassay of Serum Estrogen
Authors: Jiang Nai-Siang , Ryan Robert J , Albert A 
Published: January 2020

Abstract
Radioimmunoassay of serum estrogen (sum of estrone and estradiol-17β) in 0.5 ml of human serum is described. After dilution of the serum, the estrogens are adsorbed on a Sephadex G-15 column in the presence of dilute HCl and then eluted with benzene. After evaporation of the benzene eluate, the estrogens are dissolved in bovine serum albumin (5 g/ liter solution, at pH 8.0). An aliquot of this solution is used for the assay. Serum estrogen concentrations (mean ± SD) were 69 ± 23 pg/ml in 105 normal men and 199 ± 146 pg/ml in 26 fertile women. In 109 postmenopausal women, estrogen was undetectable in seven sera, but in the remaining 102 it was 52 ± 30 pg/ml of serum.
Assay of "Soluble Fibrinogen" in Bloodstain Extracts as an Aid to Identification of Menstrual Blood in Forensic Science: Preliminary Findings
Authors: Whitehead P H , Divall G B 
Published: January 2020

Abstract
Bloodstain saline extracts were prepared and "soluble fibrinogen" in the extract was measured by the hemagglutination inhibition technique. Total protein in the extract was also measured. Menstrual bloodstain extracts contained higher concentrations of "soluble fibrinogen" than did capillary bloodstain extracts. The two types of stain were better differentiated by calculating soluble fibrinogen as a percentage of the total protein in the extract. Extracts of capillary blood plus semen stain, and of capillary blood plus vaginal secretion stain, contained higher proportions of soluble fibrinogen than did blood alone. The results are interpreted and their use for aiding the identification of menstrual bloodstains in forensic science is discussed.
Nonutility of Measurement of Serum Gamma-Glutamyl Transpeptidase Activities in Diagnosis of Myocardial Disease
Authors: Cook Virginia P , Carter N Kent 
Published: January 2020

Abstract
We have examined the usefulness of measuring gamma-glutamyl transpeptidase activity in serum, in diagnosing myocardial damage. Abnormalities in gamma-glutamyl transpeptidase activity were compared with those observed for aspartate aminotransferase, lactate dehydrogenase isoenzymes, creatine kinase, alanine aminotransferase, and alkaline phosphatase. Such measurements were made for 12 consecutive days on 22 patients admitted to the coronary care units. Serum gamma-glutamyl transpeptidase activity was not increased in all cases studied, but when it was increased, the electrophoretic band of the lactate dehydrogenase isoenzyme originating from the liver also showed abnormal activity. We conclude that the changes observed in gamma-glutamyl transpeptidase activity primarily reflect liver involvement, as in congestive heart failure, rather than myocardial disease.
Development of an Analytical System Based Around a Miniature Fast Analyzer
Authors: Burtis C A , Johnson W F , Mailen J C , Overton J B , Tiffany T O , Watsky M B 
Published: January 2020

Abstract
A modified version of a previously described miniature Fast Analyzer [Clin. Chem. 18, 753 (1972)] was used as the basis for developing a compact, potentially portable, analytical system. This system includes an automated and versatile sample-reagent loader, a miniature Fast Analyzer, several plastic rotors and their cleaning station, and a portable data system. The sample-reagent loader combines a unique turntable assembly and two "Micromedic" pipets to quickly (5 min per rotor), accurately, and precisely obtain, transfer, and dispense small volumes of sample (1 to 10 µl of sample, 50 µl of diluent) and reagent (20 µl of reagent, 50 µl of diluent) into their respective cavities in a 17-cuvet rotor. The loader uses separate sample and reagent carousels, which allows operation of the system in either the single-sample—multiple-chemistry, multiple-sample— single-chemistry, or multiple-sample—multiple-chemistry analytical modes. The miniature Fast Analyzer rotates a loaded 17-cuvet rotor through a stationary optical system at speeds up to 5000 rpm. The resulting centrifugal force is used to mix and to transfer the discrete aliquots of sample(s) and reagent(s) into their respective cuvets. The ensuing reactions are monitored photometrically, and the data are processed in real time by either a portable Data Processor [Clin Chem. 18, 762 (1972)] or an on-line computer. A major improvement to the analyzer has been the addition of a temperature-control system that allows the temperature of the spinning rotor to be monitored and controlled to within ±0.2°C. After completion of an analytical run, the rotor is automatically washed and dried in the rotor cleaning station. Many of the standard clinical analyses, including most of the NADH-linked enzymatic analyses, have been adapted for use with this system.
Use of High-Pressure Liquid Chromatography for Monitoring Nucleotide Concentration in Human Blood: A Preliminary Study with Stored Blood Cell Suspensions
Authors: Brown Phyllis R , Parks R E , Herod Jane 
Published: January 2020

Abstract
The development of high-pressure liquid chromatography has made available a new technique for monitoring nucleotide concentrations in biological materials sensitively, accurately, and rapidly. Because there appears to be a correlation between ATP concentrations and viability of stored blood, a preliminary study was carried out on blood cell suspensions to evaluate the technique for possible use in blood banks, clinical laboratories, and research on preservatives for blood.
Automated Reaction-Rate Method for the Direct Determination of Total Serum Cholesterol by Use of the "CentrifiChem" Parallel Fast Analyzer
Authors: Slickers K A , Edwards L , Daly J , Ertingshausen G 
Published: January 2020

Abstract
The direct procedure for determining serum cholesterol described by Wybenga et al. [Clin. Chem. 16, 980 (1970)] can be used to assay 29 samples in 10-min reaction time by using the "CentrifiChem" parallel fast analyzer (Union Carbide). Commercial reference serum was used for standardization. Correlation of results with those obtained by the method of Abell et al. [J. Biol. Chem. 195, 357 (1952)] for 54 samples yielded a regression line with a slope (m) of 0.897 and a y-intercept (b) of 231 mg/liter; the correlation coefficient (r) was 0.971. Compared with the manual procedure of Parekh and Jung [Anal. Chem. 42, 1423 (1970)] for 146 samples, the corresponding values were m = 0.991, b = 27 mg/ liter, and r = 0.981. Compared to serum extracts assayed with the "AutoAnalyzer" (Standard Technicon Methodology N-24a), 186 samples gave corresponding values of m = 0.990, b = 92 mg/ liter, and r = 0.979. No bias significant at the 95% confidence level existed versus any of the three methods. Sera containing abnormally high bilirubin concentrations (&gt;50 mg/liter) or abnormally high triglyceride content (&gt;5,000 mg/liter) did not give significantly different cholesterol values on the CentrifiChem as compared with values obtained with either the AutoAnalyzer or the Parekh and Jung method.
Determination of Gold in Drugs and Serum by Use of Anodic Stripping Voltammetry
Authors: Schmid G M , Bolger G W 
Published: January 2020

Abstract
Gold is determined in aqueous gold-containing drug solutions, 8 x 10-8 to 1 x 10-5 mol/liter, and in such drugs in serum, 2 x 10-6 to 1 x 10-5 mol/ liter, by electrodeposition onto a carbon paste electrode at -0.3 V vs. a saturated calomel electrode and subsequent stripping at constant current. Aqueous solutions are prepared for electrodeposition with a ceric perchlorate—hydrogen peroxide treatment. Serum samples are in addition treated with nitric and chloric acids. Variation coefficients are 16 to 2.5%, depending on concentration and deposition time.
Purification of Progesterone Antiserum for Radioimmunoassay, by Chromatography on QAE-Sephadex A-50
Authors: Bodley Frank H , Chapdelaine Alcide , Roberts Kenneth D 
Published: January 2020

Abstract
Antibodies were generated in sheep after administration of the antigen, progesterone-11α-succinyl-bovine serum albumin. This antiserum was purified 10-fold by treatment with "Aerosil" and column chromatography on "QAE-Sephadex A-50." In addition to an increased specific activity (cpm progesterone bound/g of protein) the purified antibody fraction was less cross-reactive with pregnenolone and desoxycorticosterone than was the crude antiserum. A sensitivity of 10 pg of progesterone was obtained with the purified antibody preparation, compared to 25 pg for the crude antiserum. This method of purification of antisera was devised in order to concentrate the antibody fraction before covalent coupling to insoluble supports such as activated arylamine-glass particles.
Determination of 3-Methoxy-4-Hydroxyphenylethylene Glycol, a Noradrenaline Metabolite, in Cerebrospinal Fluid and Urine
Authors: O’Keeffe R , Brooksbank B W L 
Published: January 2020

Abstract
We describe a sensitive, accurate method for quantitative determination of 3-methoxy-4-hydroxyphenylethylene glycol (MHPG) in cerebrospinal fluid and urine. The method entails enzymatic hydrolysis of conjugated MHPG, acetylation of the phenolic group, thin-layer chromatographic purification, and estimation of total MHPG as the acetyl heptafluorobutyryl derivative by gas—liquid chromatography with electron capture detection and with use of aldrin as internal standard. Results obtained by this method compare favorably with those by other published procedures. Precision, calculated as the mean ± SD of the percentage differences between duplicate estimations, was 8.4 ± 8.0% for cerebrospinal fluid (3 ml) or 6.9 ± 6.6% for urine (2 ml). Total MHPG in lumbar cerebrospinal fluid specimens from 49 individuals ranged from 6.1 to 19.7 ng/ml, with no significant difference between the mean for control subjects and that for patients with affective disorders.
Application of an Automated Determination of Isoenzyme-5 of Lactate Dehydrogenase to the Diagnosis of Hepatic Disease
Authors: Nathan Lawrence E , Feldbruegge Donald , Westgard James O 
Published: January 2020

Abstract
We have examined the clinical usefulness of measuring the activity of LD-5 (the slowest-moving isoenzyme of lactate dehydrogenase) in serum, after its column chromatographic separation, on the Du Pont ACA. Primary and secondary diseases of the liver were readily identified. LD-5 and alanine aminotransferase activities correlated well in hepatitis and LD-5 and alkaline phosphatase activities in metastatic disease of the liver. LD-5 activity was elevated in cases of congestive heart failure, muscle trauma, and cirrhosis (when associated with active inflammation or alcoholic hepatitis). The test proved most useful for the early identification of hepatitis and tumor involvement of the liver.