bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cation-exchange chromatography of guanidine derivatives in plasma of patients with chronic renal failure.
Authors: Perez G , Rey A , Micklus M , Stein I 
Published: January 2020

Abstract
Guanidine derivatives are suspected of contributing to the toxic manifestations of uremia. We describe a method for measurement of guanidine derivatives in 5-ml samples of plasma by liquid chromatography. Concentrations of guanidinosuccinate and guanidinobutyrate in plasma were significantly increased both in undialyzed patients with chronic renal failure (5.54 +/- 0.94 and 17.5 +/- 4.07 mg/liter) and those undergoing maintenance hemodialysis (2.35 +/- 0.41 and 19.4 +/- 3.99 mg/liter) when compared to healthy controls (less than 0.4 and 1.0 +/- 0.3 mg/liter, respectively). Creatine and guanidinoacetate concentrations tended to be higher in hemodialysis patients and lower in the undialyzed group of patients with chronic renal failure. This procedure provides a rapid, sensitive, and accurate method for the study of guanidine metabolism in persons with uremia.
Polarographic method for rapid microdetermination of cholesterol with cholesterol esterase and cholesterol oxidase.
Authors: Noma A , Nakayama K 
Published: January 2020

Abstract
Cholesterol concentrations in serum are enzymatically determined rapidly by use of a polarographic oxygen analyzer with a circuit modified to record simultaneously the amount and rate of oxygen consumption. The final assay system, assessed from the oxygen consumption value that we found to be optimum, consists of 1 ml of sodium phosphate buffer (0.6 mol/liter, pH 7.0) containing NaN3 (10 mg/liter), Triton X-100 surfactant (10 ml/liter), 0.4 U of cholesterol ester hydrolase, and 0.6 U of cholesterol oxidase. Oxygen consumption and cholesterol concentration are linearly related to 8.0 g/liter, and only 10 mul of serum is required. Replicate analyses of pooled serum by the present method demonstrated the following inter-run precision: mean = 1731 mg/liter, SD = 22.3 mg/liter, CV = 1.3%. Bilirubin and ascorbic acid were without effect on the present method, unlike the enzymatic colorimetric methods.
Simple fluorometric determination of aldosterone in urine without use of isotopes or chromatography.
Authors: Whigham W R 
Published: January 2020

Abstract
Aldosterone 18-glucuronide in urine is hydrolyzed by adjusting the pH to 1.0 and allowing the mixture to stand overnight at room temperature. The free aldosterone is then extracted into dichloromethane, which is washed with carbonate to remove acidic compounds and evaporated. The residue is partitioned between a nonpolar organic phase and an aqueous phase, and the aldosterone oxidized to the 13-carboxylic acid derivative with Benedict's qualitative glucose reagent. Neutral compounds are extracted from this oxidation mixture with dichloromethane at pH 7.5, the mixture is acidified, and the oxidized aldosterone extracted into dichloromethane. After washing with pH 3.5 buffer, this extract is evaporated and the oxidized aldosterone determined fluorometrically via a two-stage reaction with sulfuric acid/water (85/15 by vol) and methanol containing ferric chloride.
Direct radioimmunoassay for serum estriol during pregnancy.
Authors: Standefer J 
Published: January 2020

Abstract
I describe an assay for serum estriol during pregnancy, which does not require prior extraction or chromatography of the serum. Fifty microliters of 20-fold diluted serum can be assayed to detect as little as 20 pg of estriol. For a 20 mug/liter serum estriol concentration the CV was 16%; for 100 mug/liter concentration it was 5%. There was no significant interference by serum "binding" proteins. The assay measures unconjugated estriol, estriol conjugated with either sulfate or glucuronide at the 3' position, and a portion of the estriol 16 alpha (beta-D-glucuronide). Serum estriol concentrations increase during gestation from a low at 20 weeks of less than 10 mug/liter to a high of 100-150 mug/liter at term. Serum estriol values correlate well with those for urinary total estrogens and with values for human placental lactogen in serum at various gestational ages.
Normative values of serum immunoglobulins by single radial immunodiffusion: a review.
Authors: Maddison S E , Reimer C B 
Published: January 2020

Abstract
Many previous studies of normative values in adults have suggested that race, age, sex, and environment all have significant effects on the mean values for IgG, IgA, IgM, and IgE in various groups of individuals. Single radial immunodiffusion is the technique most widely used to quantitate immunoglobulins of the three major classes (IgG, IgM, and IgA) in sera. Measurements have been expressed in terms of mass concentration, as percentages of the mean normal adult value, and in arbitrary international units. To improve agreement among laboratories, the WHO has supported the distribution of an International Reference Preparation for the Human Immunoglobulins IgG, IgA, and IgM, and similar (separate) preparations for IgD and IgE.
Rapid radioimmunoassay of total urinary estriol.
Authors: Anderson D W , Goebelsmann U 
Published: January 2020

Abstract
We describe a radioimmunoassay for total urinary estriol in pregnancy. A 25-mul aliquot of the urine specimen is acid hydrolyzed, neutralized, and diluted before assay. We use rabbit antisera against estriol-6-(O-carboxymethyl)oxime/bovine serum albumin and ammonium sulfate precipitation at room temperature. Results are unaffected by glucose or methenamine mandelate, a urinary tract antiseptic. Using semi-automatic pipetting equipment, one laboratory technologist can complete 50 assays within 8 h. This technique is both reliable and convenient and should decrease the expense of routine estriol assays.
Profile analysis of blood proteins with a centrifugal analyzer.
Authors: Blom M , Hjorne N 
Published: January 2020

Abstract
We describe a procedure for routine analysis of a profile composed of eight blood proteins with a GEMSAEC centrifugal analyzer. The end-point technique is used and four standards are included in each run in the immunochemical analysis of the individual proteins. Additional computer programs fit the absorbance readings from the samples to the (nonlinear) standard curve and store the results in a patient's file for a final printout, which also presents the patient's data and reference values. The proteins are analyzed in a given order, which allows common blank runs to be used. Antisera are used in suitably high concentrations, so that the "antigen in excess" problem only appears for analysis of IgA and IgM when sera contain high amounts of the M-components of these two classes. The capacity, accuracy, and precision of the method are satisfactory.
Simultaneous gas-chromatographic analysis for phenobarbital, diphenylhydantoin, carbamazepine, and primidone in serum.
Authors: Abraham C V , Joslin H D 
Published: January 2020

Abstract
We describe a simple, sensitive determination of phenobarbital, diphenylhydantoin, carbamazepine, and primidone in serum, by use of gas-liquid chromatography with temperature programming. The methylated derivatives of these anticonvulsants are well resolved, as was 5-(p-methyl-phenyl)-5-phenylhydantoin, the internal standard. The proposed procedure requires only 0.20 ml of serum and can be done in less than 30 min. The lower limit of detection for each of the drugs is 0.5 mg/liter. Analytical recoveries of drug from serum were excellent and peak height and concentration were linearly related up to twice the toxic concentration for serum.
Determination of clomipramine and desmethyl-clomipramine in plasma or urine by the double-radioisotope derivative technique.
Authors: Carnis G , Godbillon J , Metayer J P 
Published: January 2020

Abstract
A double radioisotope derivative method was developed for the determination of clomipramine and desmethyl-clomipramine in plasma or urine. After addition of 14C-labeled clomipramine and desmethyl-clomipramine as internal standards and extractive isolation of both compounds, desmethyl-clomipramine is acetylated with [3H]acetic anhydride. The [3H]acetamide is separated from clomipramine by thin-layer chromatography and its radioactivity is measured. Clomipramine, extracted from the cilica gel, is reacted with trichloroethyl chloroformate. The urethane is saponified and decarboxylated. The resulting desmethyl-clomipramine is acetylated with [3H]acetic anhydride. The [3H]acetamide is purified by thin-layer chromatography and its radioactivity is measured. The sensitivity of the method is 15 mug/liter for clomipramine and 2 mug/liter for desmethyl-clomipramine. Its specificity was made sure by a cross-check with a gas chromatography-mass spectrometry technique.
Simultaneous measurement of phenobarbital, diphenylhydantoin, and primidone in blood by high-pressure liquid chromatography.
Authors: Kabra P M , Gotelli G , Stanfill R , Marton L J 
Published: January 2020

Abstract
We describe a sensitive, precise high-pressure liquid chromatographic method in which 5-(p-methylphenyl)-5-phenylhydantoin is used as the internal standard for simultaneous determination of diphenylhydantoin, phenobarbital, and primidone in whole blood and plasma. These anticonvulsant drugs are well separated from each other and from normal blood constituents in less than 10 min. The lower limit of detection for each drug is 100 ng for primidone, 200 ng for dilantin, and 300 ng for phenobarbital. The eluted drugs were detected by their absorption at 254 nm, and evaluated from their peak heights as compared to internal standard. The method was successfully adapted for pediatric samples (100 to 500 mul of whole blood or plasma). Fifty specimens were analyzed for phenobarbital and diphenylhydantoin and 25 specimens for primidone by a standard gas-chromatographic method and by our liquid-chromatographic method; the resulting correlation coefficient was greater than 0.98.
Results of a nine-laboratory survey of forensic toxicology proficiency.
Authors: Dinovo E C , Gottschalk L A 
Published: January 2020

Abstract
Toxicological determinations are crucial to coroners' or medical examiners' judgments that drugs are significantly involved in a death. However, differences in laboratory procedures, thoroughness of screening, and limits of detection may result in artifactual differences in the toxicological results and the subsequent interpretations of them. To test this possibility, we conducted a toxicology proficiency-testing survey of nine collaborating laboratories. The results for the proficiency samples point out starting interlaboratory differences in accuracy and precision of detection of drugs. These observed variations in toxicological proficiency may introduce a significant source of error in drug-death statistics and in epidemiological deductions based on these statistics.
Primidone analyses: correlation of gas-chromatographic assay with enzyme immunoassay.
Authors: Sun L , Walwick E R 
Published: January 2020

Abstract
Serum specimens from patients on primidone therapy were assayed by two currently available procedures: a commercially available enzyme immunoassay (EMIT) and a published gas-chromatographic procedure. Both procedures were done with commercially available materials and equipment. Results by the two procedures agreed well, which suggests that the two methods could be used interchangeably. For the 94 specimens studied, the correlation coefficient was 0.98, and the least-squares values of slope and intercept were, respectively, 0.97 and 0.51 mg/liter.
Adaptation of "EMIT" technique for serum phenobarbital and diphenylhydantoin assays to the miniature centrifugal analyzer.
Authors: Brunk S D , Hadjiioannou T P , Hadjiioannou S I , Malmstadt H V 
Published: January 2020

Abstract
We used a miniature centrifugal analyzer in a spectrophotometric rate-measurement mode to determine the anticonvulsant drugs phenobarbital and diphenylhydantoin in serum, by use of a modified enzyme immunoassay ("EMIT", Syva Corp.) We decreased reagent cost per determination by at least sixfold by means of microscale techniques. Also, the analysis rate is increased by measuring multiple samples simultaneously. Our method requires only 3 mul of serum for duplicate determinations. Replicate analyses of sera containing phenobarbital and diphenylhydantoin gave reaction rates with a CV of 1.5%. Run-to-run CV was 15%. Analytical recovery for drug-supplemented serum samples was 98%, and results for a series of samples compared well with results obtained by gas chromatography (for phenobarbital, r = 0.95; for diphenylhydantoin, r = 0.91).
Monitoring drug concentrations in a case of combined overdosage with primidone and methsuximide.
Authors: Johnson G F , Least C J , Serum J W , Solow E B , Solomon H M 
Published: January 2020

Abstract
We describe a case of fatal overdosage with primidone and methsuximide. During the early phase of the patient's hospital course we found concentrations of methsuximide, N-desmethylmethsuximide, and primidone in serum that far exceeded the usual therapeutic concentrations, as determined by gas-liquid chromatography. Determination of N-desmethylmethsuximide in peritoneal fluid demonstrated concentrations comparable to those in serum. This led to the therapeutic decision to manage the patient by dialysis. Subsequently, serum samples collected during the course of hospitalization were analyzed quantitatively by gas-liquid chromatography for methsuximide, N-desmethylmethsuximide, primidone, phenobarbital, and diphenylhydantoin. Selected serum specimens were also analyzed by gas chromatography-mass spectrometry, and N-methyl-2-hydroxymethyl-2-phenylsuccinimide, a metabolite of methsuximide not previously described in human serum, was identified by analysis of its mass spectrum.
Immobilized glucose oxidase used in the continuous-flow determination of serum glucose.
Authors: León L P , Narayanan S , Dellenbach R , Horvath C 
Published: January 2020

Abstract
We used a tubular glucose-oxidase wall reactor in the "AutoAnalyzer II" continuous-flow analytical system to determine glucose in blood serum. Sensitivity was high and wash characteristics were satisfactory with use of a 30-cm tube containing immobilized glucose oxidase. Results compared favorably with those of the conventional free-enzyme method. More than 25000 such assays can be performed with a single enzyme tube, which also shows long-term storage stability. Because of the steady-state chemistry 60 samples can be analyzed per hour. The linearity of the method is excellent and sample interaction from 5.0 to 1.0 g/liter is less than 5%. Results correlate well (greater than 0.993) with those obtained with both the neocuproine method used in the "SMA 12/60" multichannel analytical system and the free glucose oxidase method used in the AutoAnalyzer.
Separation of folate binding protein from human serum by DEAE-cellulose column chromatography.
Authors: Zettner A , Duly P E 
Published: January 2020

Abstract
On diethylaminoethyl-cellulose column chromatography, the folate binding protein in the serum of 21 patients eluted in the early effluents as a single sharply defined peak. The chromatographic behavior of the folate binder remained unchanged whether or not the serum was, before chromatography, complexed with tritium-labeled pteroylglutamic acid ([3H]PGA), dialyzed, or charcoal-adsorbed. Heating to 100 degrees C for 10 min dissociated the [3H]PGA-binder complex while destroying the folate binding property. The presence or appearance of this folate binder in increased amounts in the serum of patients with various diseases may be related to conditions of increased tissue turnover.
Methotrexate in blood, urine, and cerebrospinal fluid of children receiving high doses by infusion.
Authors: Wang Y , Lantin E , Sutow W W 
Published: January 2020

Abstract
Methotrexate was determined in plasma (31 patients), urine (eight patients), and cerebrospinal fluid (two patients) after high doses (35 to 150 mg/kg) by infusion, with citrovorum factor rescue. Concentrations in plasma were proportional to dose at 6, 24, 72 h after beginning treatment, but this trend was very minimal for samples obtained at 48 h. Clinical toxicity probably will not be serious if the methotrexate concentration in the serum is less than 4.5 X 10(-6) mol/liter at 48 h after the start of a 6-h infusion. In both of the two patients so examined, therapeutic concentrations appeared in cerebrospinal fluid after intravenous infusion of the drug. A kinetic enzymic method, radioassay, and radioimmunoassay all yielded similar results for drug concentrations.
In vitro changes in blood P50 and erythrocyte 2,3-diphosphoglycerate concentration.
Authors: Aberman A , Cavanilles J M , Michaels S , Shubin S H , Weil M H 
Published: January 2020

Abstract
We studied in vitro changes in P50 and erythrocyte 2,3-diphosphoglycerate concentration occurring in blood 2 to 8 h after venipuncture. When blood was incubated at 37 degrees C, significant decreases in P50 were observed at 2, 4, and 8 hr. Such a change was significantly less when blood was kept at 4 degrees C. The rate of decrease in P50 was not changed when pH was altered by adding either lactic acid or sodium bicarbonate to the blood before incubation at 37 degrees C for 2 h. The erythrocyte 2,3-diphosphoglycerate concentration of blood incubated at 37 degrees C did not change by 2 h, but had significantly decreased by 4 h. To avoid in vitro changes, we recommend that P50 be determined as soon as possible for blood sampling.
Ultramicromethod for determination of plasma uric acid.
Authors: Kamoun P , Lafourcade G , Jerome H 
Published: January 2020

Abstract
We describe an ultramicromethod for determination of uric acid by a manual procedure. Hydrogen peroxide, formed when uric acid is oxidized in the presence of uricase, oxidatively couples two molecules of p-hydroxyphenylacetic acid in the presence of peroxidase to produce a highly fluorescent compound. The specificity of the uricase reaction is retained, and the fluorometry results in a higher sensitivity (but a lower precision) than that obtained by applying spectrophotometric methods. As little as 50 ng of uric acid can be determined, and only 10 mul of plasma is required. Values obtained for human plasma are higher than those obtained by the spectrophotometric method.
Enzyme-immunoassay.
Authors: Wisdom G B 
Published: January 2020

Abstract
The bases of the different enzyme-immunoassay techniques are described and their applications to the identification and quantification of antigens, haptens, and antibodies in biological fluids are discussed. Substances for which enzyme-immunoassays have been developed are listed. The enzymes used as labels, the methods of linking them to proteins, and the methods for separating free and bound labeled material are described. The reliability and practicality of the enzyme-immunoassay methods are reviewed.
Some theory of reference values. II. Comparison of some statistical models of intraindividual variation in blood constituents.
Authors: Harris E K 
Published: January 2020

Abstract
Three models of intraindividual variation are reviewed, and statistical methods for distinguishing among them are discussed. Application of these methods to short series of observations from healthy individuals indicates that, in the large majority of cases, a strictly homeostatic model is appropriate for such constituents as serum calcium and magnesium. In less closely controlled variables, e.g., serum cholesterol and uric acid, a nonstationary, "rndom walk" model appears moresuitable in most cases. A more general autoregressive model, which includes the other models as extreme cases, could be used to describe all degrees of homeostatic control. This model is more complex, however, and requires at least 10 observations to yield estimates of acceptable precision. Moreover, it is sensitive to fluctuations in within-batch analytical variance. When biological variance is small relative to analytical variance, all three models yield essentially the same predicated values. To illustrate their use, these models have been applied to four short individual series of cholesterol observations showing increasing amounts of intrapersonal variation over long periods of time. I suggest that when less than 10 observations over time are available, the strictly homeostatic model and the nonstationary model be used to derive a "critical range" for assessing future changes. When longer series are available, the more general model might replace the other two for this purpose, if analytical variation has remained reasonably stable (within +/- 20% of its average value) during the period of observation. Much more experience with the use of all three models in health monitoring programs would be highly desirable.
Protein-bound carbohydrates in breast cancer. Liquid-chromatographic analysis for mannose, galactose, fucose, and sialic acid in serum.
Authors: Mrochek J E , Dinsmore S R , Tormey D C , Waalkes T P 
Published: January 2020

Abstract
We describr high-resolution chromatographic analysis for protein-bound sialic acid in serum, with use of a cerate oxidimetric detector. Values for sera from normal women averaged 680.5 mg/liter, with a coefficient of variation of 23%. Including data obtained by previously developed chromatographic procedures for protein-bound mannose, galactose, and fucsoe, we assessed sera from breast-cancer patients whose malignancy had been categorized as either stable, responsive, or progressive (based on clinical observations spaced from two to five months apart). All of 12 responsive patients had decreases of protein-bound fucose averaging 34.5% (SD, 16.1) and all of 10 patients with progressive disease had increases averaging 38.3% (SD 21.5). Changes in fucose averaged less than 6.7% (SD, 4.9) for eight patients with clinically stable breast cancer. Changes in protein-bound mannose, galactose, and sialic acid did not correlate as well as did fucose with the clinical disease status of the patients.
Double spike in the electropherogram of a myeloma serum, from Bence Jones protein.
Authors: Vladutiu A O , Kohli R K 
Published: January 2020

Abstract
Serum from a 71-year-old man with multiple myeloma complicated with renal failure showed a monoclonal IgG lambda. A second spike appearing in the serum protein electropherogram, suggesting a biclonal gammopathy, was found to be due to lambda Bence Jones protein (29.9 g/liter). Lambda Bence Jones protein was also found in smaller concentration (3.8 g/liter) in the urine. Tetramers of Bence Jones protein were not demonstrable by gel filtration and ultracentrifugation, and renal failure was probably the main reason for this very high concentration of Bence Jones protein in the serum.
Clinical relevance of polyamines as biochemical markers of tumor kinetics.
Authors: Russell D H 
Published: January 2020

Abstract
The polyamines, spermidine and spermine, and their diamine precursor, putrescine, constitute a unidirectional biosynthetic pathway whose biosynthetic enzymes and accumulation patterns appear to play important roles in the regulation of growth processes. Concentrations of these compounds in physiological fluids are low or undetectable under normal conditions, are elevated in patients with metastatic cancer, and are thought to reflect growth (putrescine concentrations) and cell turnover (spermidine concentrations) of the organism. Cancers are a broad spectrum of diseases in which there are altered growth fractions and cell-turnover fractions, and therefore cancer chemotherapeutic agents have been developed to take tumor kinetics into account. Because changes in polyamines in physiological fluids reflect cell kinetics, this review compiles evidence of their efficacy as biochemical markers of cancer and suggests their possible usefulness to clinicians in rapidly assessing tumor response to chemotherapy or to multimodality therapy.