bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of chromium and cobalt in human serum by neutron activation analysis.
Authors: Versieck J , Hoste J , Barbier F , Steyaert H , De Rudder J , Michels H 
Published: January 2020

Abstract
Confusion exists about the chromium and cobalt concentrations in the serum of healthy individuals. We determined these elements by neutron activation analysis. The samples were irradiated during 12 days at a flux of approximately 10(14) neutrons.cm-2.s-1. Chromium was selectively separated by distillation after the irradiation. We obtained the following values (mean +/- standard deviation): 0.160 +/- 0.083 mug/liter for chromium, and 0.108 +/- 0.060 mug/liter for cobalt.
Tartrate-resistant (band 5) acid phosphatase activity measured by electrophoresis on acrylamide gel.
Authors: Lam W K , Lai L C , Yam L T 
Published: January 2020

Abstract
A tartrate-resistant acid phosphatase was isolated from a huma spleen infiltrated with reticulum cells of leukemic reticuloendotheliosis. The purified enzyme was used to establish the optimal conditions for quantitative analysis of this enzyme by electrophoresis on acrylamide gel. As little as 0.1 unit of enzyme activity (or 1 ng of the purified enzyme protein) could be quantitatively detected when it was mixed with 4 mg of albumin before electrophoresis.
Liquid chromatographic assay of cerfuroxime in serum.
Authors: Nilsson-Ehle I , Nilsson-Ehle P 
Published: January 2020

Abstract
We describe a procedure for determining cefuroxime concentrations in serum by using high-performance liquid chromatography. The drug is extracted from serum with dimethylformamide and separated from other substances in the extract by reversed-phase chromatography. The ultraviolet (280-nm) absorption of the effluent was monitored and quantitated based on the height of the cefuroxime peak. Intra-and inter-assay imprecision (cv) was less than 3.1 and 4.3%, respectively. Serum concentrations as low as 1.0 mg/liter could be accurately measured. No interference from various other drugs and antibiotics was found. A biological half-life of 52 min in serum was observed after intravenous injection of the drug into a human volunteer.
Radioimmunoassay for mono-(2-ethylhexyl) phthalate in unextracted plasma.
Authors: Luster M I , Albro P W , Chae K , Clark G , McKinney J D 
Published: January 2020

Abstract
We report a radioimmunoassay for mono-(2-ethylhexyl) phthalate that has been coupled to a protein carrier as a radioligand. Competitive interference tests with a variety of related compounds indicated the assay to be highly specific. Quantitative comparison of mono-(2-ethylhexyl) phthalate values in plasma and serum samples between the radioimmunoassay and gas chromatographic procedures indicated a high reliability. Because this potentially toxic compound can leach into plasma from polyvinyl plastics, this assay should be particularly useful for those involved in the manufacture or use of medical devices made of them.
Enzyme immunoassay for human apolipoprotein B, the major protein moiety in low-density- and very-low-density lipoproteins.
Authors: Fruchart J C , Desreumaux C , Dewailly P , Sezille G , Jaillard J , Carlier Y , Bout D , Capron A 
Published: January 2020

Abstract
We used enzyme immunoassay to measure apolipoprotein B concentration in human plasma. Pure lipoprotein B was isolated from serum samples of fasting normolipidemic subjects by sequential preparative ultracentrifugation and coated to a polystyrene tube surface by adsorption. Human serum samples and rabbit antiserum to human apolipoprotein B were incubated with the solid-phase lipoprotein B. Soluble antigen competed with solid-phase antigen for binding to antibodies. After washing, peroxidase-labeled sheep antibodies against rabbit immunoglobulins were added, and after further washing the bound label was assayed. This provided a direct measurement of the soluble antigen. The best technical conditions for the assay were determined. The minimum detectable concentration was 1 microgram per assay. The enzyme immunoassay yielded values that compare favorably with those obtained by radial immunodiffusion (r = 0.84) and by rocket immunoelectrophoresis (r = 0.80). The assay offers several advantages over existing techniques: sensitivity, specificity, simplicity, ane non-use of radioisotopes.
Improved column method for separating lactate dehydrogenase isoenzymes 1 and 2.
Authors: Mercer D W 
Published: January 2020

Abstract
Lactate dehydrogenase (LD) isoenzymes 1 and 2 in human serum were separated on a column of diethylaminoethyl-Sephadex. Samples layered on mini-columns were eluted with buffered sodium chloride (100, 150, and 200 mmol/liter). Lactate dehydrogenase activity in column effluents was measured by the Wacker method, and their isoenzyme content was evaluated by electrophoresis on polyacrylamide gel. Results for column-fractionated LD-1 and LD-2 were expressed in two ways: LD-1/LD-2 ratios and total LD-1 + LD-2 activities. The former is a more specific indicator of myocardial infarction than the latter. Sera from 10 patients with acute myocardial infarction (increased creatine kinease isoenzyme MB activity) exhibited ratios in the range of 0.92 to 1.56, ratios for 10 patients without heart disease (normal creatine kinase MB) ranged from 0.33 to 0.69.
Quantitation of anticonvulsant drugs in serum by gas-chromatography on the stationary phase SP-2510.
Authors: Godolphin W , Thoma J 
Published: January 2020

Abstract
A new column packing, SP-2510 DA (Supelco, Inc., Bellefonte, Pa. 16823), is an excellent stationary phase for the determination of a wide variety of anticonvulsant drugs by gas--liquid chromatography without derivatization. However, when uncomplicated extraction procedures are used, serum cholesterol interferes with the determination of primidone. By the simple expedient of adding a short "pre-column" containing another phase (SP-2250 DA) the problem is overcome.
Preservation of acid phosphatase activity in medico-legal specimens.
Authors: Lantz R K , Eisenberg R B 
Published: January 2020

Abstract
Vaginal acid phosphatase has been preserved with a protective broth containing, per liter, 50 of bovine albumin, 0.2 g of sodium azide, 10 mmol of phosphate (pH 7.4), and 9.0 g of NaCl. Samples may be maintained at ambient temperature for one month without loss of activity. Several other commonly used preservative methods are compared and are shown to be inadequate. With a constant 2.5 ml volume of the support medium, and use of a sodium thymolphthalein monophosphate method (Worthington Diagnostics), vaginal acid phosphatase activity in non-coital women is less than 10 U/liter of broth, and in recently post-coital women is more than 50 U/liter (242 +/- 104 U/liter). In vivo degradation of vaginal activity follows a nearly logarithmic course until four days after intercourse, when it reaches nearly normal values.
Evaluation of the Du Pont aca ammonia procedure.
Authors: Ijpma S T , Blijenberg B G , Leijnse B 
Published: January 2020

Abstract
We evaluated the determination of ammonia used in the Du Pont Automatic Clinical Analyzer (aca). Correlation studies were done with a manual method, based on the same enzymatic principles as the aca and with a method involving a cation-exchange resin, followed by the Berthelot color reaction. In either case, the results agreed well with the results found with the aca. For the aca the mean analytical recovery of ammonia in plasma samples was 104%. Within-run and day-to-day precision had coefficients of variation of 6% for normal values and 1 and 2% for above-normal values. The linearity, tested with primary standards and plasma samples, was good up to 1000 mumol of NH3 per liter.
Natural fluorescence in serum of patients with chronic renal failure not to be confused with creatine kinase-BB isoenzyme.
Authors: Aleyassine H , Tonks D B , Kaye M 
Published: January 2020

Abstract
We assessed the reported presence of creatine kinase-BB isoenzyme in the serum of patients with chronic renal failure. Our study showed that the blood of these patients contains a fluorescent material with an electrophoretic mobility similar to that of the BB isoenzyme on cellulose acetate strips. The fluorescing material is, however, completely distinct from BB isoenzyme and its nature is as yet undetermined.
Gas-chromatographic determination of polyol profiles in cerebrospinal fluid.
Authors: Smith S L , Novotny M , Weber E L 
Published: January 2020

Abstract
We describe a simple method for collectively determining polyols in the cerebrospinal fluid. The method consists of protein removal, sample derivatization, and gas chromatography of the trimethylsilylated polyols, with use of glass capillary columns. Nine major polyol constituents, the structures of which were verified by combined gas chromatography/mass spectrometry, can be simultaneously assayed. The presence of three polyols in the cerebrospinal fluid is reported here for the first time.
New ultraviolet (340 nm) method for assay of uric acid in serum or plasma.
Authors: Trivedi R C , Rebar L , Desai K , Stong L J 
Published: January 2020

Abstract
We propose a novel enzymatic method for assay of uric acid at 340 nm, which eliminates several disadvantages of both the colorimetric and enzymatic methods now in common use. Here, uric acid is catalytically oxidized to allantoin and hydrogen peroxide. The peroxide is reacted with ethanol in the presence of catalase to form acetaldehyde and water, and the acetaldehyde is reduced by NADH in the presence of alcohol dehydrogenase to ethanol. The decrease in absorbance at 340 nm caused by oxidation of NADH is directly proportional to the concentration of uric acid in the sample. Measurement of the change in absorbance between 20 and 200 s eliminates the need for a serum blank measurement. Absorbance and concentration are linearly related to 120 mg of uric acid per liter. The new method was compared with the uricase method in which decomposition of uric acid at 293 nm is directly measured. The results for the 47 patients' sera so examined can be expressed by the linear equation y340 = 1.0078x293 + 0.122 (r = 0.9984).
Micromethod for estimating adenosine deaminase activity in dried blood spots on filter paper.
Authors: Orfanos A P , Naylor E W , Guthrie R 
Published: January 2020

Abstract
We describe a fluorometric micromethod for measuring adenosine deaminase activity in dried blood spots on filter paper. Earlier methods require venipuncture and preparation of washed erythrocytes; in the present method, whole capillary blood, spotted on filter paper and mailed (dried) to a central laboratory, is used. The stability of the enzyme in dried blood on filter paper was assessed. The results were compared with those of a spectrophotometric method. The presence of serum appears not to affect the estimation of the activity and the method may be useful in early detection of severe combined immunodeficiency disease and hereditary hemolytic anemia.
Effect of storage on the apparent concentration of folate in erythrocytes, as measured by competitive protein binding radioassay.
Authors: Mortensen E 
Published: January 2020

Abstract
The folate concentration in erythrocytes changes during incubation. Using whole blood samples and washed erythrocytes, I find greatly increasing concentrations of folate in washed samples at 37 degrees C, decreasing concentrations in whole-blood samples. This difference in behavior depends on a thermostable, ultrafiltrable factor in plasma. Exclusion of glucose or addition of fluoride did not affect these results. Decreasing concentrations of folate were found when iodoacetate or acetylphenylhydrazine was present. At 4 degrees C the concentrations of folate were stable for 72 h. I discuss possible explanations for the observed changes and their practical significance.
Carotenoids in the leukocytes of carotenemic and non-carotenemic individuals.
Authors: Mathews-Roth M M 
Published: January 2020

Abstract
Leukocytes and leukocyte membranes isolated from the blood of carotenemic (serum carotene, 4.0 mg/liter) and non-carotenemic individuals were found to contain small amounts of carotenoid pigments. The principal pigment isolated from the leukocyte membranes of carotenemic individuals was beta-carotene. Traces of beta-carotene and other carotenoids were found in the leukocytes and leukocyte membranes of the non-carotenemic individuals.
Radioimmunoassay and radioenzymatic assay of a new aminoglycoside antibiotic, netilmicin.
Authors: Broughton A , Strong J E , Pickering L K , Knight J , Bodey G P 
Published: January 2020

Abstract
A radioimmunoassay and a radioenzymatic assay for netilmicin, a new aminoglycoside, were developed in our laboratories to assist in the study of the pharmacology of the drug and to establish values for use in its monitoring. The assays are sensitive, precise, and rapid, giving results that correlate (r = 0.90) with each other and with those of a microbiological assay in which Klebsiella pneumoniae is used as the test organism. Preliminary pharmacological studies show the drug to have a biological half-life of 135 min. which is comparable to that for other aminoglycosides.
Simultaneous detection and quantitation of drugs commonly involved in self-administered overdoses.
Authors: Howarth A T , Clegg G 
Published: January 2020

Abstract
The system described here is designed for ease of detection and quantitation of tricyclic antidepressants, benzodiazepines, and other tranquilizers now commonly found in self poisoning. An ether extract of serum is purified by acid transfer, back-extracted into ether, dried, and evaporated. The residue is run on a thin-layer plate against standards and inspected under 254-nm light. Depending on requirements, the amount of unknown may then be estimated or further chromatography performed in a different solvent. Quantitation and further confirmation of identity by staining follow. The equipment needed is very simple and many samples can be handled simultaneously and completed within a working day.
Maleimide as an inhibitor in measurement of erythrocyte glucose-6-phosphate dehydrogenase activity.
Authors: Deutsch J 
Published: January 2020

Abstract
Erythrocyte glucose-6-phosphate dehydrogenase activity is measured with a centrifugal analyzer by use of a commercial reagent kit and of the reaction glucose-6-phosphate + NADP+ leads to 6-phosphogluconolactone + NADPH. Rate of production of NADPH is measured and related to hemoglobin concentration. Maleimide is added to inhibit further production of NADPH in a secondary reaction by endogenous 6-phosphogluconate dehydrogenase. The method is compared with others that are designed to circumvent the secondary reaction by either (a) addition of excess phosphogluconate dehydrogenase to drive the secondary reaction to completion or (b) inhibition of endogenous phosphogluconate dehydrogenase by 2,3-diphosphoglycerate. The present method has the advantages that reaction rate more quickly becomes linear and reagent cost is less as compared with other methods. The within-run coefficient of variation was 3%. The various methods investigated showed good statistical correlation.
Hemoglobin electrophoresis at alkaline pH on agarose gels.
Authors: Lepp C A , Bluestein B I 
Published: January 2020

Abstract
We describe a modified thin agarose-gel system for use in primary hemoglobin screening by electrophoresis. The system makes use of a Tris-EDTA-borate-buffered agarose gel (pH 8.8) and a sodium barbital electrophoresis buffer (pH 8.6). Separation is effected in 20 min at a constant potential of 250 V. Eight samples can be simultaneously separated and the patterns made visible in 47 min. There are fewer operative steps needed in running and staining. Normal and the more common abnormal hemoglobins are separated into easily visualized and differentiated bands, with the separation of HbA and F significantly improved over that attainable by present methods.
Bile acids measured in serum during fasting as a test for liver disease.
Authors: Skrede S , Solberg H E , Blomhoff J P , Gjone E 
Published: January 2020

Abstract
Total serum bile acids were estimated by an enzymic (3alpha-hydroxysteroid dehydrogenase) method in 173 fasting patients with different liver diseases, classified into 17 groups by morphological criteria. The results were not highly correlated with those for any of the other 24 tests included in the study, but moderate correlations were observed with bilirubin or alanine aminotransferase (positive) and with prealbumin (negative) in a few patient groups. The sensitivity of total bile acids in serum of fasting individuals as a liver-function test was rather high, comparable with that of serum enzymes. When discriminant analysis was used to identify optimal combinations of tests for the separation of different groups of liver diseases, we found that data on serum bile acids added some new information to that carried by the other 24 tests.
Determination of 8-methoxypsoralen in plasma by scanning fluorometry after thin-layer chromatography.
Authors: Chakrabarti S G , Gooray D A , Kenney J A 
Published: January 2020

Abstract
A rapid and sensitive method is described for determining 8-methoxypsoralen in plasma. Plasma samples are acidified with 6 mol/liter and heated in a boiling water bath to release the plasma-bound drug nondestructively. It then is extracted into a solvent mixture consisting of benzene/ethyl acetate (9/1 by vol). The solvent phase is separated, evaporated, and an aliquot of the dissolved residue is thin-layer chromatographed, with benzene/ethyl acetete (9/1) as developing solvent. The plate is dried and the spots, made visible under ultraviolet light (320-400 nm), are scanned. The smallest amount detectable is 20 ng; the overall analytical recovery from plasma is 84%. We used the method to determine the drug in the plasma of rabbits after intravenous and oral administration of 10 mg, and in one patient after an oral dose of 30 mg.
Analysis for lead in undiluted whole blood by tantalum ribbon atomic absorption spectrophotometry.
Authors: Therrell B L , Drosche J M , Dziuk T W 
Published: January 2020

Abstract
We describe a modified tantalum ribbon atomic absorption procedure for determining lead in undiluted whole blood. An instrumentation Laboratory (I.L.) Model 151 atomic absorption spectrophotometer equipped with an I.L. Model 355 Flameless Sampler was used. The Flameless Sampler was slightly modified to include three-cycle operation instead of the normal two cycles. This modified single-beam system, equipped with background correction, allows 5-microliter specimens of whole blood to be quickly and accurately analyzed. No sample preparation other than vortex mixing is involved and method reliability has been demonstrated during an extended period of successful participation in proficiency testing studies conducted by the Center for Disease Control. This tantalum ribbon methodology has further been demonstrated to be effective both as a primary screening procedure and as a confirmatory procedure, when coupled with erythrocyte protoporphyrin determinations, in screening over 300 000 clients during a three-year period of use in the Early and Periodic Screening, Diagnosis and Treatment (EPSDT) Program in Texas.
Evaluation of the co-immobilized hexokinase/glucose-6-phosphate dehydrogenase method for glucose, as adapted to the Technicon SMAC.
Authors: Garber C C , Feldbruegge D , Miller R C , Carey R N 
Published: January 2020

Abstract
We assessed the analytical performance of the co-immobilized hexokinase (EC 2.7.1.1) and glucose-6-phosphate dehydrogenase (EC 1.1.1.49) method for D-glucose analysis on the Technicon SMAC. The enzyme-containing coils were usable for one month, or 12 000 tests. Bilirubin, hemoglobin, lipemia, creatinine, uric acid, citric acid, and ascorbic acid did not interfere. Results with this method were compared to those by the National Glucose Reference Method. The upper limits of the total error estimate (a combination of random and systematic errors) were 76, 74, and 125 mg/liter at concentrations of 500, 1200, and 3000 mg/liter, respectively. The error estimates were less than allowable errors based on medical usefulness; thus the method was judged to perform acceptably with respect to the Reference Method. We also present performance data for the routine SMAC glucose oxidase (EC 1.1.3.4)/Peroxidase (EC 1.11.1.7) 3-methyl-2-benzothianolinone hydrazone-N,N-dimethylaniline method, the direct hexokinase method with the Du Pont aca, and the glucose oxidase oxygen-rate method with the Beckman Glucose Analyzer.
A solution to the problem of bilirubin interference with the kinetic Jaffé method for serum creatinine.
Authors: Osberg I M , Hammond K B 
Published: January 2020

Abstract
We measured bilirubin interference with the kinetic Jaffé method for serum creatinine. Both pooled sera with added bilirubin and icteric patients' sera were used and results with of which gave more nearly "true" values.
Marked hyperamylasemia associated with carcinoma of the lung.
Authors: Flood J G , Schuerch C , Dorazio R C , Bowers G N 
Published: January 2020

Abstract
We present a case of marked hyperamylasemia associated with undifferentiated small cell carcinoma of the lung. The serum alpha-amylase had an electrophoretic mobility similar to that of salivary gland enzyme (s-type), and that in tissue extracts from the lung tumor and metastatic skin nodules showed similar migration. No evidence of a salivary or pancreatic cause of hyperamylasemia was found at autopsy, and macroamylasemia was excluded. We suggest that the strikingly increased serum alpha-amylase activity was a result of ectopic production of this enzyme by tumor. We compare results for this case to other published reports.
Analytical particle electrophoresis applied to immunologic research.
Authors: Blume P , Malley A , Knox R J , Seaman G V 
Published: January 2020

Abstract
The technique of analytical particle electrophoresis has been applied to the study of membrane phenomena associated with lectin stimulation of lymphocytes. It has been observed that such treatment results in a significant increase in the electrophoretic mobility of murine T-cells. Moreover, it has been demonstrated that the mobility changes in most cells are attributable to the release of a factor from relatively few cells. Preliminary evidence suggests that the murine factor has a comparatively low relative molecular mass, is heat-labile, and will alter the mobility of cultured human T-cells.
Separation and analysis of arylsulfatase isoenzymes in body fluids of man.
Authors: Bostick W D , Dinsmore S R , Mrochek J E , Waalkes T P 
Published: January 2020

Abstract
Soluble arylsulfatase (EC 3.1.6.1) is present in the body fluids of man in the form of two isoenzymes, arylsulfatase A and B, which reportedly are useful biochemical markers for certain types of malignancy. However, rapid assay of the individual isoenzymes is extremely difficult; procedures based on differential inhibition or activation of the isoenzymes in a mixture yield only semiquantitative results. A feature of these isoenzymes is their inhibition by some common anions (notably phosphate) at physiologic concentrations. The isoenzymes can be separated by anion-exchange chromatography, the B isoenzyme being eluted in the void volume and the A isoenzyme and the anionic inhibitors retarded. Lead is used to sequester phosphate, enabling measurement of A in the salt-eluted fraction. Using this technique, we have found significant elevations of B in the sera of patients with colorectal cancer. The potential of rapid, chromatographic separation coupled with continuous monitoring for arylsulfatase activity is discussed.