bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of tricyclic antidepressant, clomipramine (Anafranil), in plasma by a specific radioimmunoassay procedure.
Authors: Read G F , Riad-Fahmy D 
Published: January 2020

Abstract
A radioimmunoassay is reported for the tricyclic antidepressant drug, clomipramine (Anafranil, Geigy). Antisera generated in rabbits to clomipramine conjugated to bovine serum albumin at positions 10 and 11 were specific, cross reacting less than 5% with the pharmacologically active metabolite, desmethylclomipramine. Specificity was confirmed by the good agreement in titres observed when the samples were assayed with and without a pre-assay thin-layer chromatographic purification. Intra- and inter-assay variations were less than 8 and 13%, respectively, with a sensitivity of 175 ng/liter. Results obtained agreed well with those reported by other groups using double radioisotope derivative assays. The method has a high throughput rate, one technician can assay 200 samples in duplicate in a working week; and it is sufficiently precise, sensitive, and specific for use in routine minitoring of the drug in plasma and for checking patient compliance with dosage regimen.
Changes in serum and urine lysozyme activity after kidney transplantation: influence of graft function and therapy with azathioprine.
Authors: Horpacsy G , Zinsmeyer J , Schröder K , Mebel M 
Published: January 2020

Abstract
We investigated changes in lysozyme activity in serum and urine of kidney-transplant patients, and found that the production and catabolism of lysozyme in such patients differs markedly from that in normal subjects. Resumption of graft function decreases the high serum lysozyme activity by increasing the rate of catabolism in the transplant; at the same time, however, the production is inhibited by therapy with azathioprine. Changes in serum lysozyme activity correlate well with leukocyte count; thus its determination might be useful in monitoring immunosuppression. The urinary excretion of the enzyme, although not specific to rejection, is a good index of the degree of tubular damage.
New automated dye-binding method for serum albumin determination with bromcresol purple.
Authors: Pinnell A E , Northam B E 
Published: January 2020

Abstract
We describe a new automated dye-binding method for serum albumin determination with bromcresol purple (BCP) that has several advantages over an existing bromcresol green (BCG) method. The continuous-flow method is sensitive, linear, and precise, with negligible sample interaction at an analytical rate of 60 samples per hour. Unlike BCG, BCP did not react with an albumin-free serum globulin preparation or pure human transferrin solutions. Reaction with serum was instantaneous; in contrast, BCG exhibits a slow nonspecific reaction with some specimens. The specificity of BCP was demonstrated by good agreement with results of "rocket" immunoelectrophoresis (EIA) where y(BCP) = 0.95X(EIA) + 1.72. The BCG method overestimated serum albumin concentration where y(BCG) = 1.01X(EIA) + 6.77. Precipitation, which affects the BCG method, was not observed with BCP. Blank corrections were negligible, salicylate did not interfere, and bilirubin affected the method only if present in very high concentration. The method offers a solution to the poor accuracy of existing BCG methods while retaining many of their desirable features.
Applications of a new instrument, the potentiophotometer.
Authors: Carroll W E , Jackson R D , Wilcox A A 
Published: January 2020

Abstract
The Potentiophotometer is a new instrument for measuring the absorption characteristics of solutions. A brief description of its construction and theory of operation is presented, with illustrations of its use in the colorimetric quantitative analysis for inorganic phosphorus and total protein in serum. The potentiophotometric results correlate well (r = 0.97 to 0.98) with measurements made of the same solutions with either of two conventional spectrophotometers, the Gilford 300N and the Coleman Jr. II.
Automated metabolic profiling of organic acids in human urine. I. Description of methods.
Authors: Gates S C , Dendramis N , Sweeley C C 
Published: January 2020

Abstract
We describe a complete procedure for separation and mechanized analysis of organic acids in human urine. The acid fraction of urine is separated by anion-exchange chromatography on diethylaminoethyl-Sephadex. Individual acids are identified and measured by use of a gas-chromatography/mass spectrometer/computer system that can clearly distinguish contributions from at least 150 substances in a single sample. We discuss analytical recoveries, contributions from the sample separation process, stability of stored samples before and after processing, and reproducibility of the extraction procedure.
Effects of bilirubin on detection of hydrogen peroxide by use of peroxidase.
Authors: Witte D L , Brown L F , Feld R D 
Published: January 2020

Abstract
Bilitubin interferes with the quantitation of hydrogen peroxide in reagent systems in which peroxidase is used. Difference spectra suggest that this interference is a combination of chemical and spectral effects. The data presented are most consistent with the following interpretation: (a) bilirubin destroys part of the reactive intermediate formed in the peroxidase reaction and thus decreases the amount of chromophore formed and (b) the spectra for bilirubin and the chromaphore overlap, which also affects the results. The relevance of these results to reagent design and laboratory quality control are discussed.
Chemical and immunochemical measurement of total iron-binding capacity compared.
Authors: Buffone G J , Lewis S A , Iosefsohn M , Hicks J M 
Published: January 2020

Abstract
Radiometric, colorimetric, and two immunochemical methods for measuring total iron-binding capacity are compared. We evaluated the procedures on the basis of precision, applicability to a pediatric population, and accuracy as assessed by analytical recovery of purified transferrin. The immunoephelometric assay for transferrin provides significant advantages over the other methods examined.
Immobilized-enzyme nylon-tube reactor for routine determination of uric acid in serum.
Authors: Sundaram P V , Igloi M P , Wassermann R , Hinsch W 
Published: January 2020

Abstract
We report here the preparation of an immobilized-enzyme nylon-tube reactor containing uricase (EC 1.7.3.3) and the assembly of a flow-through system (Technicon AutoAnalyzer II) for the routine determination of uric acid in serum. Results of these uric acid analyses by use of immobilized uricase, in conjunction with peroxidase (EC 1.11.1.7) and aminophenazone-dichlorophenol in solution, are compared with those obtained with the same enzyme in solution by use of the uricase-PAP (peroxidase, 4-aminophenazone, dichlorophenol) method. Clinical trials carried out routinely with the uricase reactor give reliable and reproducible results with high precision at an appreciably lower cost. The reactors are stable to continued or intermittent use for at least three months or for 4000 tests.
Increased creatine kinase isoenzyme MB values in patients without myocardial infarct.
Authors: Shaw L M , Newman D A 
Published: January 2020

Abstract
Six of 13 randomly selected patients in a medical intensive-care unit with above-normal creatine kinase MB activities had diagnoses other than myocardial infarction. These data, which indicate the need for further study, were obtained during evaluation of a commercially available column procedure (Biodynamics/bmc).
Reduced-volume radioimmunoassays for parathyrin and calcitonin in serum, for use in pediatric and small-animal studies.
Authors: Heath H , DiBella F P 
Published: January 2020

Abstract
Radioimmunoassays for circulating parathyrin and calcitonin used in most laboratories require 0.6--0.7 ml of serum or plasma, or more, for assay of one hormone. Such volumes are often difficult to obtain safely or repeatedly from pediatric patients or in small-animal studies. We modified our existing procedures to markedly decrease sample and reagent requirements. All reagent volumes were proportionately reduced to one-fourth the usual (from 500 microliter final incubation volume to 125 microliter), and serum or plasma volumes from 200, 100, and 50 microliter to 50, 25, and 10 microliter. We used smaller (10.3 X 50 mm) tubes and slightly modified the separation with charcoal. Results, validated by studies in rats, showed the sensitivity to match that of the usual assays; inter- and intra-assay variance was less than 20%. Simultaneous regular- and reduced-volume assays of parathyrin in sera from 19 children gave almost identical results (r = 0.9987). Both hormones can be assayed in less than 400 microliter of serum.
Estimation of free triiodothyronine in serum: a new method and its clinical relevance.
Authors: Siegel L , McDonald L J , Robin N I 
Published: January 2020

Abstract
We describe a method for estimating free triiodothyronine in serum by polyacrylamide gel filtration. Precise and easy to perform, it avoids the lengthy incubation required for equilibrium dialysis. Results of this procedure correlate well with those by the dialysis method over a wide range of thyroid states. The role of free triiodothyronine as part of a protocol for the evaluation of thyroid status is discussed.
Serum prostate-specific acid phosphatase: development and validation of a specific radioimmunoassay.
Authors: Vihko P , Sajanti E , Jänne O , Peltonen L , Vihko R 
Published: January 2020

Abstract
We describe radioimmunoassay for human prostatic acid phosphatase [orthophosphoric-monoester phospho-hydrolase (acid optimum), EC 3.1.3.2] in serum, with use of monospecific antisera raised in rabbits against highly purified acid phosphatase from human prostates. The antiserum did not cross react with partly purified acid phosphatases from human spleen, erythrocytes, or synovial tissues. 125I-labeled acid phosphatase was prepared by a Chloramine T method, and the bound and free antigen was separated in the assay by use of anti-rabbit gamma-globulin raised in sheep. Uniform low nonspecific binding of the [125I]acid phosphatase was achieved by using acid-phosphatase-free serum to prepare standard curves and diluted samples of serum with high acid phosphatase activities. Concentrations of immunoreactive acid phosphatase in the serum of healthy men ranged from less than 1 to 10 microgram/liter and for 12 patients with advanced prostatic carcinoma between 100 and 500 microgram/liter. The concentrations of the enzyme in sera of patients with benign prostatic hyperplasia were very similar to those in sera of the reference group.
Simultaneous determination of retinol and retinyl esters in serum or plasma by reversed-phase high-performance liquid chromatography.
Authors: DeRuyter M G , De Leenheer A P 
Published: January 2020

Abstract
We propose a single-run liquid-chromatographic determination, with ultraviolet detection at 330 nm, for serum retinol and retinyl esters. The vitamin A derivatives are extracted according to the Bligh-Dyer procedure. With 200 microliter or serum, the lower detection limit is 50 microgram/liter for retinol and about 100 microgram/liter for retinyl esters. Within-run precision (CV) was 2.3% for retinol, 4.3% for retinyl palmitate. Day-to-day percision (CV, n = 20) for retinol was 4.9% during a month. The method can be used for the assessment of vitamin A absorption tests and for the determination of serum retinol (normal, subnormal, and above-normal concentrations). Serum retinyl esters can only be measured in conditions where concentrations exceed 100 microgram/liter.
A water-soluble cholesterol derivative for use in augmenting serum control materials.
Authors: Proksch G J , Bonderman D P 
Published: January 2020

Abstract
Cholesterol determination has been hampered by the lack of suitable means to prepare lyophilized serum control materials with an appropriate range of values. We prepared a water-soluble cholesterol derivative by first esterifying cholesterol with adipic acid and then reacting the cholesterol hemiadipate with Polyethylene Glycol 600 to form polyethoxyethanyl-cholesteryl adipate. The compound reacts quantitatively in several commonly used methods, including enzymic, extraction, and direct-assay procedures. When the additive is directly mixed with human serum that has been depleted of beta- and pre-beta-lipoproteins, an optically clear solution results for which cholesterol values are stable. The clarity is retained upon lyophilization and reconstitution. Addition of this cholesterol compound to partially delipidized serum appeared to have no significant effect on results of assay of 18 other commonly measured serum constituents.
Standardization of the Coomassie Blue method for cerebrospinal fluid proteins.
Authors: Johnson J A , Lott H A 
Published: January 2020

Abstract
Coomassie Brilliant Blue G-250 can be used to quantitatively determine proteins in cerebrospinal fluid. When the dye combines with protein, the absorption maximum of the dye shifts. The dye-protein color forms almost instantaneously and is stable for at least 1 h. The procedure is also insensitive to changes in temperature in the range of 20--30 degrees C. The absorptivities of the dye complexes with human albumin or globulin differ, thus a pure albumin or pure globulin standard is unsuitable; a standard containing 70% albumin and 30% globulins is the most appropriate for this application. A bichromatic approach to standardization increases the range of linearity of a calibration curve. The method gives values that are about 9% higher than a sodium sulfate-sulfosalicylic turbidimetric procedure for cerbrospinal fluid proteins.
Serum ionized calcium and corrected total calcium in borderline hyperparathyroidism.
Authors: Larsson L , Ohman S 
Published: January 2020

Abstract
We studied 25 borderline-hyperparathyroidism patients whose total serum calcium concentration was within normal limits (reference range: 2.25--2.75 mmol/liter) but whose concentrations of serum ionized calcium were above normal (reference range: 1.03--1.23 mmol/liter). Their hyperparathyroidism was histopathologically verified. To compare the discriminating value of corrected serum calcium with ionized calcium, we studied the serum calcium and albumin concentrations in a reference group of 2098 patients. After patients from endocrine and dialysis departments were excluded from the reference group, we obtained the range (mean +/- 2 SD) 2.05--2.71 mmol/liter for uncorrected serum calcium and 2.11--2.63 mmol/liter for corrected serum calcium. The correction factor for calcium on albumin was 20 mumol/g. Even with this limit for corrected serum calcium, 13 of 25 borderline hyperparathyroidism patients had values that fell within the reference range. We conclude that correcting total serum calcium values for serum albumin concentration improves discrimination of borderline hyperparathyroid patients, but that measurement of ionized calcium in serum discriminates better.
Rational basis for foam-stability assays of amniotic fluid surfactant.
Authors: Freer D E , Statland B E , Sher G 
Published: January 2020

Abstract
We evaluated the relative contributions of various phospholipids to the formation of foam in the amniotic fluid "foam stability test", by use of an artificial system of saline, ethanol, and dipalmitoyl 3-sn-phosphatidylcholine to determine the relationship between dipalmitoyl 3-sn-phosphatidylcholine concentration, ethanol volume fraction, and the threshold of formation of stable foam. At dipalmitoyl 3-sn-phosphatidylcholine concentrations of 20, 40, and 80 mg/liter, the threshold ethanol volume fraction was 0.46, 0.48, and 0.51, respectively. We similarly evaluated the ability of other phospholipids to form stable foam at various concentrations and ethanol volume fractions and found: bovine brain sphingomyelin greater than dipalmitoyl 3-sn-phosphatidylcholine greater than egg sphingomyelin greater than egg lecithin greater than phosphatidylglycerol. The corresponding propensities of different chemical species of phosphatidylcholine to form foam at 40 mg/liter were: dipalmitoyl 3-sn-phosphatidylcholine greater than dioleoyl phosphatidylcholine greater than dimyristoyl phosphatidylcholine greater than dilauroyl phosphatidyl-cho-line.
Isoenzyme distribution of creatine kinase and lactate dehydrogenase in serum and skeletal muscle in Duchenne muscular dystrophy, collagen disease, and other muscular disorders.
Authors: Yasmineh W G , Ibrahim G A , Abbasnezhad M , Awad E A 
Published: January 2020

Abstract
We determined the total activity and isoenzyme distribution of lactate dehydrogenase and creatine kinase in serum and biopsy specimens from skeletal muscle of nine normal individuals and nine patients with Duchenne muscular dystrophy (I), five with collagen disease (II), and four with non-progressive unclassified myopathy (III). Mean total serum creatine kinase in patients with Duchenne muscular dystrophy (867 U/liter, SD = 197) was 31-fold that in the control group (28 U/liter, SD = 14). There was also a small (3.3-fold) increase in the mean total serum creatine kinase of patients with III, but none in the serum from patients with II. Changes in the creatine kinase isoenzyme distribution of skeletal muscle were primarily in the MB isoenzyme. The mean percentage of creatine kinase-MB activity in muscle from patients with I (2.81, SD = 1.15) and patients with III (1.69, SD = 1.07) significantly (P less than 0.005) exceeded that of the control group (0.43, SD = 0.18). Muscle from patients with II showed little change. The most striking changes in lactate dehydrogenase were also observed in patients with I, in whom the mean total serum activity (356 U/liter, SD = 115) was 3.4-fold that of serum from the control group (105 U/liter, SD = 19). Skeletal muscle from these patients also showed a significant decrease in mean percent isoenzyme 5 activity (from 50 to 23) and an increase in that of isoenzymes 1 and 2 (from 1 to 9 and 8 to 20, respectively). These changes in the distribution of these two sets of isoenzymes in muscle were reflected in the serum.
Copper coproporphyrin excretion in familial coproporphyria.
Authors: Carlson R E , Dolphin D , Bernstein M 
Published: January 2020

Abstract
Analysis of stool specimens from a patient with familial coproporphyria by high-performance liquid chromatography revealed that 112 microgram per gram of dry feces (14% of the total porphyrin present) was copper coproporphyrin. Examination of stool specimens from other patients with this disease confirmed the presence of significant amounts of both copper coproporphyrin and coproporphyrin. Further investigation showed that the copper coproporphyrin was probably formed by a nonenzymic incorporation of copper by the coproporphyrin in either the bile or feces.
Manual and centrifugal analyzer determination of cholesterol and triglycerides with single-vial enzymatic reagents.
Authors: Peake M J , Sontrop M E , Fraser C G 
Published: January 2020

Abstract
We have assessed Calbiochem single-vial enzymatic reagent systems for the analysis for cholesterol and triglycerides, using manual and centrifugal analyzer techniques. Analysis for cholesterol by both techniques had acceptable performance by the short-term criteria of the Center for Disease Control (CDC) during this study carried out under optimal conditions of variance. Analysis for triglycerides by the manual technique did not meet CDC criteria, and we do not recommend use of this method. Analysis for triglycerides by the centrifugal analyzer technique had acceptable short-term precision but had unacceptable accuracy at high concentrations of triglycerides; this method may be considered to have acceptable performance for routine laboratory use.
On the biosynthesis of guanidinosuccinate.
Authors: Natelson S , Tseng H Y , Sherwin J E 
Published: January 2020

Abstract
We report a study motivated by a report that guanidinosuccinate is formed by transamidination from arginine to aspartate by perfused liver [J. Clin. Invest 57, 807 (1976)]. We prepared viable liver cells and incubated them with [14C]arginine labeled at the guanidino carbon and aspartate labeled at the methylene groups with tritium. A diacetyl-reacting band, similar to that reported with the perfusate in the above reference, was obtained by column chromatography. This band did not give a Sakaguchi reaction and contained no measurable tritium or 14C. Thus it did not derive from aspartate or arginine. On electrophoresis at pH 5.0, the diacetyl-reacting material moves to the cathode, guanidinosuccinate to the anode. The absorption spectrum of the diacetyl-reacting band showed a double peak, with maxima at 539 and 432 nm; guanidinosuccinate has only one maximum, at 533 nm. The diacetyl reagent reacts with sulfhydryl compounds and polypyrroles (e.g., bilirubin) to produce blue colors with significant absorbance in the 432-nm range. We saw no evidence for guanidinosuccinate formation by transamidination in these experiments with viable liver cells.
Non-chromatographic screening test for hyperprolinemia.
Authors: Yamaguchi Y 
Published: January 2020

Abstract
This procedure for determining serum proline in patients with hyperprolinemia involves protein precipitation (Folin-Wu method), color development with isatin, extraction of the color with methylene chloride and measurement of its absorbance at 600 nm. The specificity and analytical recovery show the method to be suitable for this use.
Sensitive radioimmunological screening test for antithyroglobulin autoantibodies.
Authors: Bodlaender P , Arjonilla J R , Twomey S L 
Published: January 2020

Abstract
The test described here was designed as a screening test to be used in conjunction with the radioimmunoassay for human thyroglobulin. Anti-thyroglobulin autoantibodies, when present even in low concentrations, interfere with thyroglobulin determination. A 30-min incubation allows binding of 125I-thyroglobulin to endogenous anti-thyroglobulin autoantibodies. A subsequent 2-h incubation with goat anti-human gamma-globulin causes precipitation of such complexes. The immunoprecipitable radioactivity reflects the binding capacity of the sample for 125I-labeled thyroglobulin. Samples that are devoid of autoantibodies, and are therefore suitable for valid thyroglobulin determinations, bind less than 6% of the radiolabeled thyroglobulin. The sensitivity of this radioimmunoassay exceeds that of the tanned-erythrocyte hemagglutination test.
Electroimmunoassay, radioimmunoassay, and radial immunodiffusion assay evaluated for quantification of human apolipoprotein B.
Authors: Curry M D , Gustafson A , Alaupovic P , McConathy W J 
Published: January 2020

Abstract
We examined three immunoassay techniques for measuring apolipoprotein B in serum and major lipoprotein density fractions from normolipidemic and hyperlipoproteinemic persons, comparing values by electroimmunoassay, radioimmunoassay, and radial immunodiffusion assay with those determined gravimetrically. Electroimmunoassay is faster and simpler than radioimmunoassay, and equally precise (within- and between-assay coefficients of variation for both were 5 and 7%, respectively). All the immunoassays gave results that agreed with those by gravimetry for normolipidemic sera and the corresponding lipoprotein density fractions, but only electroimmunoassay results agreed with those by gravimetry for apolipoprotein B in lipoproteins of d less than 1.019 g/ml isolated from hypertriglyceridemic patients. Concentrations of apolipoprotein B in plasma, determined by electroimmunoassay in a population of normal persons and patients with primary hyperlipoproteinemias, were: normals, 980 +/- 200; type I, 700 +/- 160; type IIa, 2000 +/- 260; type IIb, 2180 +/- 300; type III, 1300 +/- 340; type IV, 1470 +/- 400; and type V, 1550 +/- 390 mg/liter (mean +/- SD). Lipoprotein density fractions from the hyperlipoproteinemic patients each had a characteristic distribution of free and associated forms of lipoprotein family B. The absolute concentration and distribution of apolipoprotein B between the free and associated forms of lipoprotein B may represent a useful indicator of the underlying biochemical defect(s).