bluuebunny/crossref_metadata_2025_split huggingface dataset:
Automated "Gamma-flo" radioimmunoassay of urinary cyclic AMP.
Authors: Brooker G , Murad F 
Published: January 2020

Abstract
The "Gammaflow" automated assay concept of Brooker et al. (Science 194:270, 1976) has been adapted to the assay for urinary cyclic AMP in patients' samples on the now commercially available Squibb Gamma-FloTM system, a totally automated continuous-flow immunoassay instrument. The instrument aspirates the unknown sample, combines it with radioligand and specific antiserum, incubates the mixture, separates antibody-bound radioligand from free radioligand, counts the radioactivity of the bound ligand, computes the standard curve, and determines subsequent unknown samples by comparison to the standard curve. The urinary cyclic AMP assay we report here is rapid, accurate, and concentrations of cyclic AMP as low as 15 nmol/L can be detected. The assays, which can be done at 60 determinations per hour, are accurate at all dilutions of urine tested and inter-assay (day-to-day) CVs were 3.9% at the midpoint of the standard curve (B/B0 = 0.49).
Effect of dimethyl sulfoxide on serum osmolality.
Authors: Runckel D N , Swanson J R 
Published: January 2020

Abstract
Consecutive values for serum osmolality measured in a patient exceeded (548 mOsm) the previously reported pathological range and, indeed, exceeded that generally considered compatible with life. The patient was receiving large amounts of intravenous dimethyl sulfoxide as part of an experimental protocol to control intracranial pressure resulting from trauma. This compound increases serum osmolality linearly with respect to concentration over the range considered therapeutically significant, 0 to 10 mL/L. The mechanism of its effect on osmolality readings is discussed. It does not interfere with any values for those routine measurements made by continuous-flow (SMAC, Technicon).
A study of the use of polyethylene glycol in estimating cholesterol in high-density lipoprotein.
Authors: Demacker P N , Hijmans A G , Vos-Janssen H E , van't Laar A , Jansen A P 
Published: January 2020

Abstract
We studied polyethylene glycol 6000 precipitation of lipoproteins other than high-density lipoproteins, before cholesterol is estimated in the supernate. Other lipoproteins in the supernatant fractions were detected by using rocket immunoelectrophoresis. A polyethylene glycol concentration of 75 g/L in the final mixture appeared to be optimal, and results agreed with those obtained by ultracentrifugation. Differences in serum pH, use of polyethylene glycol from different suppliers, or the presence of ethylenediaminetetraacetate resulted in values that differed significantly (by 40 to 60 mumol/L) from the reference values. Polyethylene glycol did not interfere in four different methods for determination of cholesterol. In combination with an enzymic cholesterol method, the polyethylene glycol method appeared to be very precise, even when lipemic sera (triglycerides up to 5.5 mmol/L) were analyzed that had diminished high-density lipoprotein cholesterol values. We consider this method a method of choice, especially when lipemic sera are tested and enzymic cholesterol analysis is used.
A digitally linearized thermistor thermometer referenced to IPTS-68.
Authors: Berger R L , Clem T , Gibson C , Siwek W , Sapoff M 
Published: January 2020

Abstract
We describe a digitally linearized thermistor thermometer that is accurate to ±0.01 °C from 0 to 60 °C at a wattage of 50 microW and a sampling time of 1 s. It is traceable to the International Practical Temperature Scale of 1968 (IPTS-68). Analog and digital outputs are provided, the latter as ASCII RS-232C. The thermistor is a 10-cm long immersible probe, 1.5 mm in diameter. Only 0.5 cm of the probe need be immersed, with proper heat sinking of at least 1 cm of the remaining 9.5 cm, for accurate readings. Error from self-heating of the thermistor is less than 5 × 10(-3) °C at all power settings from 50 to 1 microW.
Radioimmunoassay of creatine kinase B-isoenzymes in serum of patients with azotemia, obstructive uropathy, or carcinoma of the prostate or bladder.
Authors: Homburger H A , Miller S A , Jacob G L 
Published: January 2020

Abstract
We measured the concentrations of creatine kinase B-isoenzymes by radioimmunoassay in 271 serum specimens from patients with azotemia, benign prostatic hyperplasia, adenocarcinoma of the prostate, and transitional cell carcinoma of the bladder. There was no correlation between the concentrations of B-isoenzymes and creatinine in the sera of azotemic patients. Above-normal concentrations of B-isoenzymes were found in sera from three patients with acute renal failure, but in only two of 28 specimens from patients with chronic renal failure. Above-normal concentrations of B-isoenzymes also were found in sera from three of 18 patients with untreated carcinoma of the prostate, 10 of 25 patients with treated carcinoma, 20 of 135 patients with benign prostatic hyperplasia, and 10 of 33 patients and with transitional cell carcinoma of the bladder. An above-normal concentration of B-isoenzymes in serum has a low predictive value for adenocarcinoma of the prostate, was not a sensitive indicator of the presence of carcinoma, and was noted paradoxically in six patients with treated carcinoma who had normal acid phosphatase activities in serum. We conclude that routine measurement of B-isoenzymes is not useful to establish the diagnosis of adenocarcinoma of the prostate.
Gas-chromatographic method of analysis for urinary organic acids. II. Description of the procedure, and its application to diagnosis of patients with organic acidurias.
Authors: Tanaka K , West-Dull A , Hine D G , Lynn T B , Lowe T 
Published: January 2020

Abstract
A gas-chromatographic method for urinary organic acid analysis is described, designed to be used routinely for the diagnosis of organic aciduria. It involves extraction of urine with ethyl acetate, dehydration of extract residues, and trimethylsilylation. Organic acids are identified by using an extensive list of retention indices published in the accompanying paper (this issue). Quantitative values are given for organic acids in urines from 50 ostensibly normal subjects. Typical chromatograms of urinary organic acids from patients with eight well-established organic acidurias are also shown.
Determination of beta-choriogonadotropin in human plasma; evaluation and comparison of five "kit" methods.
Authors: Knox B S , McKee J W , Hair P I , France J T 
Published: January 2020

Abstract
We evaluated five quantitative, commercially available radioimmunoassay methods (Beta-Tec, BIO-RIA, Cambridge Nuclear, Mallinckrodt, and Serono) for rapid determination of the beta-subunit of human choriogonadotropin in serum or plasma. Only three of the kits (Beta-Tec, Mallinckrodt, and Serono) were found suitable for reliable determination of low concentrations of this analyte, which is of importance in the early diagnosis of trophoblastic disease in men and monitoring effectiveness of chemotherapy of trophoblastic tumors in men and women.
Interlaboratory evaluation of four RIA kits for determination of plasma cortisol, with special reference to accuracy: influence of matrix in calibration standards.
Authors: Lantto O , Björkhem I , Blomstrand R , Kallner A 
Published: January 2020

Abstract
We used four RIA kits for determination of plasma cortisol to assay 12 plasma samples in four laboratories, and compared the results with those obtained with a highly accurate method based on isotope dilution/mass spectrometry. All kits (Farmos, NEN, Sorin, and Clinical Assays) showed 10-50% deviation from the comparison method in the normal range (200-700 nmol/L). The inter- and intralaboratory imprecision (CV) ranged between 8-27% and 5-11%, respectively. Possible explanations for this low accuracy are discussed. Retention of an intact biological matrix in the calibration standards seems to be one prerequisite for accuracy.
Apparent normal leukocyte acid maltase activity in glycogen storage disease type II (Pompe's disease).
Authors: Potter J L , Robinson H B , Kramer J D , Schafter I A 
Published: January 2020

Abstract
We present a case of glycogen storage disease type II (Pompe’s disease) with the classical clinical presentation and characteristic electrocardiographic changes of this disorder. An acid maltase (EC 3.2.1.20) determination in the peripheral leukocytes revealed normal activity; however, acid maltase activity was completely absent in a pre-mortem skeletal muscle biopsy. Post-mortem studies showed acid maltase activity to be absent in all tissues examined, including cultured skin fibroblasts. Massive glycogen deposition corresponded to the localization of the enzymic deficiency, except in the brain, where glycogen content was within the normal range. The acid maltase activity in mixed peripheral leukocytes was due to an isoenzyme of acid maltase in the granulocyte series. Antenatal diagnosis was accurate in a subsequent pregnancy, but discordance between enzyme activity in different cell lines in an individual with a genetic disease is a conceivable source of error in both prenatal and postnatal diagnoses.
Isolation and characterization of a human pancreas-specific protein.
Authors: Nerenberg S T , Prasad R , Pedersen L , Biskup N S , Faiferman I 
Published: January 2020

Abstract
Homogenates of human pancreas in saline were centrifuged at 27 000 X g and the supernates were fractionated by preparative polyacrylamide gel electrophoresis. The gels were divided into sections and each section was injected into rabbits; after absorption with polymerized serum from apparently normal humans, the antiserum obtained by injecting one of the sections was tested against a variety of human tissue extracts but reacted only with saline extracts of human pancreas. The absorbed antiserum, polymerized and made insoluble with glutaraldehyde, was used to purify a pancreas-specific antigen by immunoaffinity batch technique. The purified antigen proved to be a protein with some carbohydrate content (180 mg/g by weight) and a molecular mass of about 2.25 X 10(5) daltons. The antigen is relatively thermostable, and precipitates in the range of 245.64-340.2 g/L saturated ammonium sulfate; its antigenic activity is not affected by incubation with ribonuclease or deoxyribonuclease, but is destroyed by incubation with trypsin or neuraminidase and by extraction with perchloric acid. Immunofluorescence studies show that the antigen is diffusely present in the cytoplasm of pancreatic acinar cells.
Radioimmunoassay for detection of latent chronic alcoholic pancreatitis, an unrecognized clinical syndrome.
Authors: Nerenberg S T , Prasad R , Pedersen L D , Biskup N S 
Published: January 2020

Abstract
We developed a radioimmunoassay procedure in which we used an antibody monospecific for pancreatic acinar antigen, to sensitively and specifically test for the presence of subclinical (latent) alcoholic pancreatitis. The antigen was isolated, purified, and partially characterized. Results of testing appropriate populations of patients support the idea that chronic alcoholism is associated with chronic, subclinical damage to the pancreas and concomitant continuous release of a pancreatic acinar protein into the peripheral circulation, where it can be detected and quantitated. About 40% of the samples from chronic alcoholics (whether during a bout of acute alcoholism or during abstinence) demonstrated the circulating antigen, strongly suggesting that those alcoholics who will develop symptomatic, chronic alcoholic pancreatitis can be readily detected during the non-symptomatic stage.
Use of 3,5-dichloro-2-hydroxybenzenesulfonic acid/4-aminophenazone chromogenic system in direct enzymic assay of uric acid in serum and urine.
Authors: Fossati P , Prencipe L , Berti G 
Published: January 2020

Abstract
A new direct colorimetric procedure for uric acid assay in serum or urine is described, utilizing a 3,5-dichloro-2-hydroxybenzene sulfonic acid/4-aminophenazone chromogenic system in the presence of horseradish peroxidase and uricase from Aspergillus flavus. This chromogen system has a high absorptivity, affording useful results with sample/reagent volume ratios as low as 0.025. The procedure is applicable to serum, plasma, or diluted urine. A single working reagent is used; the reaction is complete in less than 15 min at room temperature. The red dye formed is measured at 520 nm; a blank sample measurement is not needed. The standard curve for the method is linear for uric acid concentrations up to 1500 mumol/L. Average analytical recovery of uric acid in human sera and urine exceeded 99%; within-run and between-run precision studies showed CV's of less than or equal to 1.2 and less than or equal to 2.2%, respectively. The new procedure correlated well with the uricase/catalase and uricase/ultraviolet methods. The method is suitable for automation.
Effects of centrifugation, storage, and contamination of amniotic fluid on its total phospholipid content.
Authors: van Voorst tot Voorst E J 
Published: January 2020

Abstract
The total phospholipid content of the supernatant fluid decreases rapidly with increasing relative centrifugal force when amniotic fluid is centrifuged. Possible explanations for this are discussed. The effect of storage on the total phospholipid content of amniotic fluid at different temperatures and the influence of contamination with blood and meconium are also described.
Hepatic function in mononucleosis induced by Epstein-Barr virus and cytomegalovirus.
Authors: Horwitz C A , Burke M D , Grimes P , Tombers J 
Published: January 2020

Abstract
We evaluated serial enzyme and bilirubin determinations as aids to diagnosis of Epstein-Barr virus-induced infectious mononucleosis (121 cases) and the heterophil-negative mononucleosis-like illness due to cytomegalovirus (33 cases). Laboratory evidence for either type of mononucleosis includes mild to moderate hepatic dysfunction, with aspartate aminotransferase activity increased, but lower than commonly encountered in active viral hepatitis. Of the enzymes commonly assayed in evaluating liver function, aspartate aminotransferase activity was the most commonly abnormal: in 96.7% of those with Epstein-Barr virus disease and 87.9% with cytomegalovirus disease. Values for alkaline phosphatase were increased in 94.2% of the Epstein-Barr virus cases and 63.6% of the cytomegalovirus cases, and gamma-glutamyltransferase values were increased in 90.9% and 75.8%, respectively. We conclude that, in serially studied patients, normal results for liver-function studies or very high aspartate aminotransferase activities (greater than 1000 U/L) eliminate, for practical purposes, both Epstein-Barr virus and cytomegalovirus as diagnostic considerations.
Specific lymphocyte phospholipid changes in chronic renal failure.
Authors: Kalofoutis A 
Published: January 2020

Abstract
I describe phospholipid fluctuations in lymphocytes of peripheral blood of patients with chronic renal failure who were undergoing maintenance hemodialysis. The findings of decreased concentration of total phospholipids, phosphatidylcholine, and phosphatidylethanolamine, and increased concentrations of phosphatidylinositol and diphosphatidylglycerol are discussed, in relation to the lymphocyte membrane enzymic systems, and immune response.
Continuous-flow fluorometry of low galactose concentrations in blood or plasma.
Authors: Henderson J M , Fales F W 
Published: January 2020

Abstract
Clearance of 0-100 mg/L concentrations of galactose from the blood depends on nutrient hepatic blood flow. We can measure such concentrations, which was not previously possible, by a continuous-flow method involving the use of galactose oxidase and peroxidase, the latter being coupled to a fluorogenic substrate, p-hydroxyphenylacetic acid. Interfering substances in the peroxidase reaction are removed by zinc/alkali precipitation. Sensitivity is maximized by using saturating concentrations of the enzymes and substrate. In prepared plasma test samples with galactose concentrations of 10, 40, 70, and 100 mg/L, the within-run CV's ranged from 2.1 to 8.6%, and day-to-day CV's from 2.2 to 17.2%, the largest CV's being for the 10 mg/L concentration. Normal subjects are shown to clear galactose more efficiently than subjects with moderate cirrhosis.
Improved protein-binding radioassay for plasma cortisol.
Authors: Novacenko H , Halpern F , Sachar E J 
Published: January 2020

Abstract
We describe an improved competitive protein-binding radioassay for total plasma cortisol, which permits rapid analysis of many samples. Plasma, 0.1 mL, is directly applied to a Whatman 3MM filter-paper strip, which is extracted once with dichloromethane. The extract is evaporated and the residue is assayed directly by the micro-method of Murphy (J. Clin. Endocrinol. Metab. 27: 973, 1967). Comparison with the original Murphy method (ethanol extraction) yielded excellent agreement (r = 0.988). One hundred samples, in duplicate, can easily be assayed at a time.
Digitalis glycosides in serum, urine, and cerebrospinal fluid, determined with a commercial radioimmunoassay.
Authors: Nore A K , Storstein L , Larsen A , Amlie J P 
Published: January 2020

Abstract
We evaluated a commercial (Clinical Assays, Inc.) 125I radioimmunoassay for digitoxin for use in measuring cardiac glycosides in serum, buffer, urine, and cerebrospinal-fluid samples. We also assessed interference of seven cardioactive metabolites of digitoxin, including digoxin, with the assay. The precision of the assay was adequate for all matrixes studied for glycoside concentrations less than 5 microgram/L. Reactivity in the assay was dependent on the nature of the matrix: buffer and serum samples containing digitoxin showed a stronger reactivity than did samples of urine and cerebrospinal fluid. Patients' samples must therefore be analyzed with a standard curve prepared by use of the same matrix. The digitoxosides of digitoxin showed a slightly higher reactivity in the assay than did digitoxin itself, but digitoxigenin showed a 50% lesser reactivity. Digoxin, its digitoxosides, and digoxigenin hardly react at all in the assay and so do not interfere with digitoxin determinations.
Improved direct specific determination of serum iron and total iron-binding capacity.
Authors: Ceriotti F , Ceriotti G 
Published: January 2020

Abstract
Serum iron is released from transferrin and reduced at pH 1.7 by treating serum with a 10 g/L ascorbic acid solution in 0.1 mol/L HCl. When ferrozine is added to this reagent, it forms a complex with iron that is as intensely colored as at higher pH values, and under these conditions no turbidity is produced. The second major interference, that from copper, is eliminated by adding 1 g of thiosemicarbazide per liter, which at a low pH forms a stable, uncolored complex with copper without affecting the reaction of ferrozine with iron.
Evaluation of an immobilized-enzyme analyzer for measuring galactose in serum.
Authors: Buffone G J , Johnson J M , Lewis S A , Sparks J W 
Published: January 2020

Abstract
Reportedly, galactose provides an alternative carbohydrate source and improved homeostatic regulation of glucose in the premature infant. Because of its potentially toxic effects, sensitive methods are needed for monitoring its concentration during therapy. We evaluated an immobilized galactose oxidase/hydrogen peroxide electrode system and a modified homogeneous enzymic method. Both methods are suitable for measuring galactose in a small sample and are comparably precise. The latter method gives superior analytical recoveries below 100 mg/L, but is linear in absorbance response to only 300 mg/L. We find the immobilized-enzyme method superior for monitoring treatment of neonates with galactose, because it requires only a few minutes and 25 microL of serum, and the analytical procedure is simpler.
Adaptation of the enzyme-multiplied immunoassay for methotrexate to the centrifugal analyzer.
Authors: Finley P R , Williams R J , Griffith F , Lichti D A 
Published: January 2020

Abstract
We adapted the homogeneous enzyme-multiplied immunoassay for methotrexate to the centrifugal analyzer. The sensitivity of the assay has been extended from 200 nmol/L down to 12.5 nmol/L. Several protocols may be followed, depending on whether the samples to be tested are from patients on low- or high-dose methotrexate regimens. Precision, accuracy, and sensitivity were satisfactory. Comparison with the enzymic-inhibition method (x) gave the following least-squares regression: y = 1.002 x - 0.013 mumol/L; r2 = 0.9721; Sy/x = 0.014 mumol/L.
Incidence of a split alpha 2-glycoprotein band in the electrophoretic pattern for serum of adenocarcinoma patients.
Authors: Dermer G B , Silverman L M , Gendler S J , Tökés Z A 
Published: January 2020

Abstract
We electrophoresed serum samples on Mylar-backed cellulose acetate membranes and stained for glycoproteins with the periodic acid—Schiff reagent. The samples were from untreated adenocarcinoma patients, adenocarcinoma patients receiving chemotherapy, and patients with other malignancies, and also from patients with benign proliferative diseases, inflammatory diseases, and other non-malignant conditions. Forty-five per cent of the sera from untreated adenocarcinoma patients and 80% of those from adenocarcinoma patients with progressive systemic disease exhibited a splitting of the alpha 2-glycoproteins into a fast and slow band. Such a pattern was seen in only 4% of the non-adenocarcinoma cancer patients and 4% of the control group. Serial studies indicated that electrophoretic patterns of alpha 2-glycoproteins change with clinical status. Non-cancer patients with high concentrations of acute-phase proteins in their serum did not exhibit two alpha 2-glycoprotein bands. Further characterization of serum proteins from the fast alpha 2 region suggest that alpha 1-acid glycoprotein and haptoglobin beta chains are the principal components staining with periodic acid—Schiff reagent. These components are markedly less apparent in, or are absent from, the fast alpha 2 region of normal sera.
Qualitative testing for circulating immune complexes by use of zone electrophoresis on agarose.
Authors: Kelly R H , Scholl M A , Harvey V S , Devenyi A G 
Published: January 2020

Abstract
On binding of antibody to antigen an immune complex is formed that has a net surface charge different from that of either of the two components. This, together with clonal restriction of the antibody response, gives rise to distinctive patterns that are readily apparent in stained agarose gels after routine zone electrophoresis. Most circulating immune complexes appear as a rectangular pattern, with well-defined edges, located in the gamma-region. The identity of the material responsible for these patterns has been established by three different experimental approaches: analysis of tetanus/anti-tetanus complexes formed in vitro, analysis of sera from rabbits with experimental immune complex disease, and analysis of human type II and type III cryoglobulins. Studies of reproducibility, interfering substances, and correlation with other assays for detecting immune complexes indicate that zone electrophoresis in agarose gel is a sensitive, highly specific technique for immune complex detection, of potential value as a screening tool.