bluuebunny/crossref_metadata_2025_split huggingface dataset:
Creatine kinase isoenzymes in cerebrospinal fluid in a case of brain damage.
Authors: Bayer P M , Gabl F , Granditsch G , Widhalm K , Zyman H , Deutsch E 
Published: January 2020

Abstract
We present a case of a 11/2-year-old boy with toxic enteritis, consecutive consumption coagulopathy, and sever brain damage. During the acute phase we found high activity of the BB isoenzyme of creatine kinase in cerebrospinal fluid, but not in the serum. Isoenzyme MM could also be found in the spinal fluid (37.9% of the total activity). We conclude that analysis for creatine kinase isoenzymes in spinal fluid is of clinical importance.
The free-falling drop detector--a nover fluorescence detector for high-performance liquid chromatography.
Authors: Martin F , Maine J , Sweeley C C , Holland J F 
Published: January 2020

Abstract
A novel fluorescence detector for high-performance liquid chromatography has been designed to minimize the instrumental limitations of conventional flow-through, fluorometers. This unit contributes less than 5 mul to the "dead volume" of the chromatographic system. Sensitivity comparable to that of existing flow-through fluorometers has been attained without optimizing instrumental parameters. Performance of the unit has been evaluated with reference samples containing saccharides typical of glycosphingolipids. Future improvements are discussed.
Instrumental sample-preparation technique for an automated immunohematology assay system.
Authors: Blume P , Polesky H F , Mathys J , Hanson M , Taylor D G 
Published: January 2020

Abstract
In the course of the development of an automated immunohematology assay system, we have produced, in prototype form, an instrumental device capable of accepting an unmeasured quantity of whole, anticoagulated blood and deriving from it multiple fixed-volume aliquots of plasma and cells.
Diagnosis of infectious hepatitis by multicomponent analysis with use of field ionization mass spectrometry.
Authors: Anbar M , Dyer R L , Scolnick M E 
Published: January 2020

Abstract
Field ionization mass spectrometry has been applied to multicomponent analysis of metabolites in human urine for the diagnosis of metabolic disorders, exemplified here by infectious hepatitis. The molecular weight profiles of carboxylic acids and of "neutral" metabolites in the urine of patients with infectious hepatitis were compared with those in urine of normals. The "neutral" metabolites showed 24 characteristic spectral differences in the range 68 to 215 atomic mass units, which provided correct diagnoses in 100% of the cases and a "diagnostic power" of unity. These results are even more encouraging than those obtained earlier with the acidic metabolites, where 11 mass numbers were found in the same mass range to be useful for correct diagnoses in 91% of the cases. The measurements were performed on urine samples preextracted on Amberlite XAD-2 columns. We used a quadrupole mass spectrometer interfaced with a multichannel analyzer for mass analyses.
Profiles of ultraviolet-absorbing components of urine from autistic children, as obtained by high-resolution ion-exchange chromatography.
Authors: Lis A W , Mclaughlin I , MPCLAUGHLIN R K , Lis E W , Stubbs E G 
Published: January 2020

Abstract
Urines from 19 autistic children (3 female, 16 male) were analyzed by high-resolution, high-pressure anion-exchange chromatography. The results showed abnormalities in the excretion of hippuric acid, 4-hydroxyhippuric acid, and N1-methyl-2-pyridone-5-carboxamide, the end product of the nicotinic acid pathway. Considerations as the metabolic origin on the 4-hydroxyhippuric acid are discussed and related to the possibility of bacterial action and malabsorption.
Automated computer analysis for enzyme-multiplied immunological techniques.
Authors: Rodbard D , McClean S W 
Published: January 2020

Abstract
The dose/response curve in enzyme-multiplied immunoassays (EMIT) and related techniques may be described by the same "four-parameter logistic function" as has proven useful in radioimmunoassays, immunoradiometric assays (IRMA), and two-site immunoradiometric ("sandwhich") assays. This function provides an empirical description of the dose/response curve by use of an objective least-squares regression analysis, with the advantages of computerization and automation. This facilitates further statistical analyses, quality control, estimation of precision for an unknown, and improved, objective estimation of the sensitivity or minimal detectable dose.
Enzyme immunoassay of serum thyroxine with the "Autochemist" multichannel analyzer.
Authors: Galen R S , Forman D 
Published: January 2020

Abstract
We have modified the homogeneous enzyme immunoassay of thyroxine and have adapted it to the AutoChemist. Both enzyme immunoassay and radioimmunnoassay procedures were performed on 2016 patients' sera on which thyroxine determinations had been ordered. We find the automated enzyme immunoassay to be precise and accurate, and for the first time it permits total automation of an immunoassay on a multichannel biochemical-profiling instrument. More importantly, it represents the first time that a thyroid-function test has been included in a multitest biochemical screening profile performed on a single automated instrument.
Simplified micro-scale procedure for preparing samples for theophylline determination by liquid chromatography.
Authors: Nelson J W , Cordry A L , Aron C G , Bartell R A 
Published: January 2020

Abstract
We describe an improved procedure for the preparation of plasma or serum for determination of theophylline by reverse phase high-performance liquid chromatography. Quantitative results are available in less than 30 min from receipt of sample. The chromatogram is complete in 8 to 16 min, which includes the use of an internal standard. Sample preparation consists of simple solvent denaturation of the sample proteins, and centrifugation to remove protein before chromatography. No precolumn is required to pretect the separating column. No interference was noted when sodium or lithium heparin or ethylenediaminetetraacetate were used as anticoagulants, but citrate treatment proved to be unsatisfactory because of a highly absorbing band that eluted with the same retention volume as theophylline.
Characteristics of binding between reagent-strip indicators and urinary proteins.
Authors: Bowie L , Smith S , Gochman N 
Published: January 2020

Abstract
We describe the binding characteristics of two indicator dyes that are widely used in commercial "dip-stick" indicators for protein in urine. Binding was studied by both gel filtration chromatography and by spectrophotometric titrations. The results demonstrate that the well-known lack of sensitivity of these strips to proteins other than albumin relates to the number and affinity of binding sites on these proteins as compared to albumin. The data suggest that these test strips can screen more effectively for albuminuria than for other proteinurias.
Comparison of human prostatic acid phosphatase by measurement of enzymatic activity and by radioimmunoassay.
Authors: Foti A G , Herschman H , Cooper J F 
Published: January 2020

Abstract
We compared results of measurement of prostatic acid phosphatase activity in serum and various tissues by enzymatic assay and radioimmunoassay. By enzymatic assay, activity in serum is lost rapidly, even at room temperature. In contrast, there was no change in antigenic activity during 48 h by radioimmunoassay. The radioimmunoassay was more specific in 12 tissues and in serum than were several enzymatic assays that make use of inhibitors of the enzyme. The enzymatic assay resulted in 26.6% (24/90) false positives from non-prostatic cancer patients. In contrast, with radioimmunoassay there were only 5.5% (5/90) false positives. We conclude that immunological detection of prostatic acid phosphatase is the more reliable technique.
Measurement of plasma lipoproteins by electrophoresis on polyacrylamide gel.
Authors: Muñiz N 
Published: January 2020

Abstract
Results of densitometric analysis of lipoprotein peaks after electrophoresis on polyacrylamide gel and values obtained by the classical method of ultracentrifugation/precipitation correlate well. The correlation coefficients for high-density, low-density, and very-low-density lipoproteins are 0.85, 0.99, and 0.99, respectively. Thus the densitometric method for lipoprotein analysis appears to be suitable for routine clinical application.
Zinc, iron, copper, and magnesium concentrations in tissues of rats fed various amounts of zinc.
Authors: Kang H K , Harvey P W , Valentine J L , Swendseid M E 
Published: January 2020

Abstract
An experiment was conducted with rats to determine the effects on the tissue concentrations of Zn, Fe, Cu, and Mg of feeding various amounts of zinc. The rats were pair-fed one of the following diets for four weeks: Diet A, a zinc-deficient diet; a diet containing the recommended amoun of zinc (diet A plus 55 microgram of zinc per gram of diet), or diet A plus 550 microgram zinc per gram of diet. Concentrations of these elements in various tissues were determined by atomic absorption spectrometry after wet digestion. Feeding the rats zinc-supplemented diets resulted in increased zinc in blood, heart, kidney, and liver, and a marked decrease of iron in kidney and liver. Concentrations of the other two elements were unchanged in all tissues. Thus, the effect of zinc in decreasing iron concentrations in liver, observed by several investigators when rats were fed toxic amounts of zinc, also occurs when zinc is administered in normal or subtoxic amounts.
Application of a method for correcting an observed regression between change and initial value for the bias caused by random errors in the initial value.
Authors: Blomqvist N , Cederblad G , Korsan-Bengtsen K , Wallerstedt S 
Published: January 2020

Abstract
When studying the correlation between the change of a variable during treatment and the value before treatment, random errors (errors of measurement as well as intra-individual biological variation) may yield seriously biased results. In the present work a method to adjust for this bias is presented. The method was applied to data from blood coagulation factor and plasma protein analyses in chronic alcoholics before and after one week of abstinence. It was found that many of the significant correlations were lost when the data were adjusted.
Radioimmunoassay for digoxin with a fully automated continuous-flow system.
Authors: Greenwood H , Landon J , Forrest G C 
Published: January 2020

Abstract
We describe a fully automated continuous-flow radioimmunoassay for digoxin with use of a Technicon AutoAnalyzer system. It makes use of antibodies linked to magnetizable particles; a magnet separates the bound and free fractions. The precise dispensing of reagents by the AutoAnalyzer system permits a small incubation volume (about 160 microliter) and the reproducible timing enables non-equilibrium conditions to be used. Thus a single sample is assayed in 15 min, with a sample throughput of 30/h. The standard curve ranges from 0.5 to 8.0 microgram/liter and is most precise between 1 and 3 microgram/liter, the between-assay coefficient of variation being less than 3%. There is no significant carryover between samples of high and low concentration, and results by the method correlate closely (r = 0.969) with those by an established manual assay in which charcoal separation is used.
Radioimmunoassay for MM and BB isoenzymes of creatine kinase substantiated by clinical application.
Authors: Fang V S , Cho H W , Meltzer H Y 
Published: January 2020

Abstract
We have developed a radioimmunoassay technique that is highly specific for measuring the MM isoenzyme of creatine kinase. The specificity of the radioimmunoassay for the BB isoenzyme was poor. In patients with treated Duchenne-type muscular dystrophy or untreated hypothyroidism, the MM isoenzyme, but not the BB isoenzyme value, was consistently above above normal. In the radioimmunoassay for the BB isoenzyme the antisera might cross react with other materials and the inactivated isoenzyme, but not with MM or MB isoenzymes.
Simplified radioimmunoassay of urinary drugs of abuse adsorbed on ion-exchange papers.
Authors: Alexander G J , Machiz S 
Published: January 2020

Abstract
A convenient screening procedure for presence of drugs of abuse in urine consists of two steps: adsorption of the drugs from urine onto a paper loaded with cation-exchange resin and detection of the adsorbed drugs by direct radioimmunoassay. The first step can be performed in the field, the second in a central laboratory. Storage and transport to the laboratory are simplified because specimens adsorbed on dried paper are stable and can be sent in letter-mail. In the laboratory, a small disc of the ion-exchange paper is exposed to antigen and antibody, rinsed, and tested for radioactivity. Discs treated with positive urines are more radioactive than discs from negative urines.
Comparison of immunoglobulin determinations in pathological sera by radial immunodiffusion and laser nephelometry.
Authors: Virella G , Fundenberg H H 
Published: January 2020

Abstract
Immunoglobulins G, A, and M were measured by radial immunodiffusion and by laser nephelometry in sera from 33 patients and in a preparation of purified colostral IgA. In general the results agreed for the two methods, with some exceptions attributed to the physicochemical characteristics of the immunoglobulins assayed: low-molecular-weight (monomeric) IgM gives falsely high values and IgA proteins (consisting predominantly of polymeric molecules) give falsely low values when assayed by radial immunodiffusion. Results from laser nephelometry apparently are not affected by the molecular-size characteristics of the proteins assayed.
Determination of cyanide and nitroprusside in blood and plasma.
Authors: Rodkey F L , Collison H A 
Published: January 2020

Abstract
A procedure was refined for quantitative isolation of cyanide by gas transfer from acidified blood or plasma samples. The cyanide was trapped in dilute alkali and quantified as the pyridine/pyrazolone complex. The within-day coefficient of variation was 2%, which increased to about 2.5% for the day-to-day variation. Nitroprusside used as a hypotensive agent in clinical medicine provides a risk of cyanide toxicity when the rate of administration or the total amount of drug given is excessive. A procedure was developed for measuring nitroprusside in the plasma of man and animals. Nitroprusside in the sample is quantitatively converted to cyanide by incubation with cystein solution at slightly alkaline pH. Methemoglobin is added to combine with the cyanide formed and prevent its destruction. On acidification, the total amount of cyanide originally present as free cyanide or as nitroprusside is liberated as HCN, isolated by gas transfer into a sodium hydroxide trap, and quantified by spectrophotometry. Nitroprusside present in the sample is calculated from the increase in cyanide observed in the cysteine-treated sample compared to that obtained without cysteine treatment. The method has been used to estimate in vitro stability of nitroprusside in aqueous solution, blood, and plasma. Blood cyanide and plasma nitroprusside concentrations were measured when sodium nitroprusside was infused into a baboon. Over 90% of the nitroprusside in blood is present in the plasma, suggesting that the drug crosses the erythrocyte membrane slowly.
Fluorescent assay of total serum cholesterol, with use of gas-liquid chromatography to study saponification efficiency.
Authors: Majeski E J , Seltzer E J , Carter P L , Howlett D R , Stuart J D 
Published: January 2020

Abstract
We describe a fluorescent determination of total cholesterol in serum for which the accuracy and precision are comparable to that for the method of Abell-Kendall, a method of generally accepted accuracy. By the use of quality reagents and the rigorous exclusion of water, the strong fluorophor that develops on reacting concentrated sulfuric acid with cholesterol can be used to quantitatively determine the total cholesterol in serum. We used gas-liquid chromatography to monitor the extent of saponification of the cholesterol esters, because we found them to have fluorescent efficiencies that differed from that of free cholesterol. Sodium methoxide in methanol/methylene chloride (1/3 by vol) was shown by gas-liquid chromatography to very effectively saponify the cholesterol esters in serum.
Colorimetric determination of phospholipids by use of molybdophosphate, and its application to amniotic fluid.
Authors: Worth H G , Wright D J 
Published: January 2020

Abstract
We studied the reaction between molybdophosphoric acid and lecithin. The resulting complex was isolated and shown to contain molybdophosphate and lecithin in the molar ratio 1/3. It is insoluble in water but soluble in chloroform, and the reaction is specific for molecules containing electrophilic nitrogen, indicating good specificity in biological fluids for nitrogen-containing phospholipids. In solution the complex may be reduced, yielding molybdenum blue. We applied the reaction to the measurement of phospholipid concentrations in amniotic fluid. As compared with procedures involving either digestion or the determination of lecithin/sphingomyelin ratio, the present technique is faster and its analytical precision exceeds that of the lecithin/sphingomyelin ratio determination. Although results by the three methods do not correlate well, the predictive value of the present method appears to be comparable with the other two.
Radioimmunoassay for flupenthixol in plasma.
Authors: Robinson J D , Risby D 
Published: January 2020

Abstract
We describe a radioimmunoassay for the neuroleptic drug flupenthixol, suitable for routine monitoring of its concentration in blood. Antibodies for the assay were raised in a sheep against a 7-carboxyflupenthixol/ovalbumin conjugate. The resulting assay, with [3H] flupenthixol as the label, is capable of detecting 2.0 microgram of flupenthixol per liter, in a 100-microliter plasma sample. The antiserum shows no cross reactivity with tricyclic drugs and low interference from the major metabolites of flupenthixol. Concentrations in plasma after a single oral dose of flupenthixol have been followed in one volunteer. Peak values were reached after 3 h. Determinations of flupenthixol after fortnightly intramuscular depot injections of the sustained-release preparation, flupenthixol decanoate, showed the extent of fluctuations during this period.
Effects of ethanol (0.75 g/kg body weight) on the activities of selected enzymes in sera of healthy young adults: 2. Interindividual variations in response of gamma-glutamyltransferase to repeated ethanol challenges.
Authors: Freer D E , Statland B E 
Published: January 2020

Abstract
We measured individual temporal changes in gamma-glutamyltransferase activity in serum after four consecutive ethanol challenges in each of eight apparently healthy volunteers. Each challenge consisted of ingesting 0.75 g of ethanol per kilogram of body weight on two evenings, followed by five days of abstention during which the activity was assessed at regular intervals. A nine-day abstention period preceded the study, and initial baseline activity was determined. The highest values for the group mean activity were +12%, +11%, +22%, and +18% greater than baseline after the first, second, third, and fourth ethanol challenges, respectively. We noted marked intra-individual and interindividual variation in the enzymic response; peak values ranged from +1% in one subject to +57% in another. The possible causes for these biological variations are discussed.
Albumin/calcium association at different pH, as determined by potentiometry.
Authors: Fogh-Andersen N 
Published: January 2020

Abstract
Calcium binding by albumin was determined potentiometrically at physiological ionic strength and temperature as a function of pH. The binding data indicate at least 30 different binding sites with different association constants and different H+ interaction. One site appears to be responsible for the major binding at physiological pH and substance concentration of free calcium, together with three other sites that bind with less affinity.
Removal of interference by erythromycin, phenazopyridine, and methenamine mandelate in the Porter-Silber reaction.
Authors: Furuya E 
Published: January 2020

Abstract
Erythromycin, phenazopyridine, methenamine mandelate, acetazolamide, and ascorbic acid reportedly interfere with the Porter-Silber reaction in the determination of urinary 17-hydroxycorticosteroids. Sodium bisulfite, added to the urine after hydrolysis with glucuronidase, removed almost all nonsteroidal interferences in urine from healthy adults medicated with the first three drugs, but such studies proved that acetazolamide and ascorbic acid do not interfere with the Porter--Silber reaction, whether or not sodium bisulfite is added.
A solid-phase enzyme immunoassay for serum ferritin.
Authors: Thériault L , Pagé M 
Published: January 2020

Abstract
We describe an enzyme immunoassay for human serum ferritin in which antibody adsorbed on polystyrene tubes is used. Adsorbed gamma-globulins against human ferritin were first allowed to react with ferritin and a second antiferritin antibody, labeled with alkaline phosphatase, was added. The amount of bound enzyme/antibody conjugate was proportional to the ferritin titer in the assay. This method offers stable reagents that can be kept for many months at 4 degrees C. The average values for ferritin in normal men and women were, respectively, 58 and 43 microgram/liter. The lowest detectable concentration was 5 microgram/liter.
Plasma alkaline phosphatase assay: interconversion of results by two methods.
Authors: Eaton R H 
Published: January 2020

Abstract
Two methods for measuring plasma alkaline phosphatase activity are compared: one makes use of phenyl phosphate, carbonate-bicarbonate buffer, and continuous-flow methodology; the other of p-nitrophenyl phosphate, diethanolamine buffer, and reaction-rate analysis. Results by the methods correlate well (r = 0.98) over a wide range of values (up to 10-fold the upper limit of normal). A factor can therefore be applied to convert results by one method into those that would be obtained by the other. The possibility that the presence of different proportions of isoenzymes in the plasma will affect this factor is considered. We have used the new method, with a conversion factor, as the routine method of alkaline phosphatase measurement in a clinical chemistry laboratory, with no problems.
Evaluation of Ames' "Clini-Tek".
Authors: Peele J D , Gadsden R H , Crews R 
Published: January 2020

Abstract
Reproducibility of reading "N-Multistix" dipsticks by a semi-automated urinalysis instrument (Ames' "Clini-Tek") has been described for artifically prepared samples. Glucose, ketone, urobilinogen, and nitrite showed high reproducibility (greater than 90%) for reading multiple samples at predetermined analyte concentrations. Determination of proteinuria showed the lowest proportion of false positives (2-3%) and false negatives (0%). Determination of hemoglobinuria and bilirubinuria by dipsticks were the least reproducible. Urobilinogen showed no interference from bilirubin in concentrations up to 32 mg/liter. Precision was high for results for quality-control capsules provided by the manufacturer.