bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantitation of Beta Lipoprotein (LDL) Cholesterol by Densitometric Evaluation of Disc Electropherograms
Authors: Moran Robert F , Castelli William P , Moran Marianne V 
Published: January 2020

Abstract
This paper describes a rapid, facile, and accurate new procedure for determination of marginal Type IV or Type II hyperlipoproteinemias, in which discontinuous (disc) electrophoresis on polyacrylamide gel is used to quantitate LDL (beta) cholesterol without ultracentrifugation. Fasting sera, previously assayed by ultracentrifugation and chemical technique, were prestained with Sudan Black, and the lipoproteins were separated by disc electrophoresis. The beta-lipoprotein fraction of each electrophoretic pattern was quantitated by densitometry. The values for the integrated densitometric peak areas for the beta fraction and the chemically assayed cholesterol of the ultracentrifuged LDL fraction correlated well (r = .90). Results were determined from a curve relating chemical concentration of the integrated peak values by densitometry to the known LDL cholesterol of a series of standards.
Use of Thin-Layer Chromatography on Silica Gel for Serum Lipid Fractionation and Measurement in the Routine Clinical Laboratory
Authors: Chedid Antonio , Haux Peter , Natelson Samuel 
Published: January 2020

Abstract
A procedure, appropriate to use in the routine laboratory, is described for thin-layer chromatographic separation of serum lipids on silica gel, followed by molybdate coloring and densitometry. Cholesteryl aniline is used as the internal standard. The procedure is recommended as a screening procedure for presenting graphically the lipid distribution in the serum. Fractions separated and values (±1 SD) obtained from light-transmission measurements, for 70 apparently healthy adults, were: phospholipids, 239 ± 69 mg/dl; monoglycerides, &lt;5 mg/dl; cholesterol, 53 ± 12.2 mg/dl; diglycerides, &lt;5 mg/ dl; free fatty acids, 14.3 ± 8.9 mg/dl; triglycerides, 89 ± 30 mg/dl; and esterified cholesterol, 164 ± 25 mg/dl. The method was applied to the study of distribution of lipids in the serum of patients with various diseases.
Rapid Identification of Psychopharmacologic Agents in Cases of Drug Abuse
Authors: Sohn David , Simon Julius 
Published: January 2020

Abstract
When a patient is hospitalized in coma with suspected drug overdose, rapid identification of psychopharmacologic or toxic agents is essential. Methods for excluding other common toxic agents are indicated. Psychomimetic drugs that should be identified are enumerated. Screening by thin-layer chromatography is suggested as the method of choice, with confirmation or quantification by gas chromatography. Appropriate references to current methodology are appended.
II. Biochemical Investigations
Authors: Rimington C , Sears W G , Eales L 
Published: January 2020

Abstract
The urinary porphyrin excretion of the patient (Part I) has been examined. Methods for determination of the various porphyrin fractions have also been compared and critically assessed. A thin-layer chromatographic technique was found to be rapid, discriminating, and precise. Of solvent-extraction procedures, that of Rimington and Benson for the determination of urinary "X" porphyrins gives results that compare well with those obtained by the quantitative chromatographic procedure. The patient excreted relatively large amounts of uroporphyrin, heptacarboxylic porphyrin, and "X" porphyrins. In addition, the hydroxycoproporphyrins 1 and 2 of Elder were present in the ether-soluble fraction of her urine in relatively large quantities during the period when the patient was severely ill. Her fecal porphyrins were not markedly increased. The porphyria exhibited by this case of Felty’s syndrome resembled the characteristic pattern of symptomatic porphyria, usually associated with alcoholism, but in this case other factors must be considered because this patient was a life-long abstainer from alcohol.
Activation of Serum Creatine Kinase by Dithiothreitol
Authors: Warren William A 
Published: January 2020

Abstract
I studied activation of serum creatine kinase (CK) by sulfhydryl reagents, and the optimum assay conditions. Dithiothreitol and β-mercaptoethanol were the best activators. Dithioerythritol, L-cysteine, glutathione, and mercaptoacetate were less effective. Over a dithiothreitol concentration range from 0.02 to 2 mmol/liter, enzyme activity increased with increasing dithiothreitol. Activation was maximum between 2 and 20 mmol/liter. At any dithiothreitol concentration the rate of activation was rapid, and the activity attained did not increase on prolonged preincubation. Thus, the extent of activation of serum CK by dithiothreitol is largely a thermodynamically-controlled, not a kinetically-controlled, phenomenon.
Improved Determination of Total Serum Lipids by the Sulfo-Phospho-Vanillin Reaction
Authors: Frings Christopher S , Fendley Ted W , Dunn Ralph T , Queen Cecelia A 
Published: January 2020

Abstract
We have modified and improved a colorimetric method for determining total serum lipids [Amer. J. Clin. Pathol. 53, 89 (1970)]. The improved procedure requires only 20 µl of serum, and the entire determination is done in one tube, thus eliminating the tedious pipetting of a concentrated sulfuric acid-serum digest. The phospho-vanillin reagent has been modified so that the linearity of the method now extends to 1250 mg/dl. Concentrations up to 1240 mg/dl or of bilirubin up to 20 mg/dl in the serum do not interfere. The relative standard deviation for the method (day-to-day) is 4.9%.
Automatic System for Urine Analysis. I. System Design and Development
Authors: (Tom) Clemens Anton H , Hurtle Richard L 
Published: January 2020

Abstract
Development of an automatic system for urine analysis is described. A bench-top instrument will simultaneously perform seven chemical tests and give a value for the specific gravity of urine specimens, at a sample rate of 120 specimens per hour. Reagents packaged in a unique reagent cassette are used for protein, glucose, ketone, pH, occult blood, and bilirubin, and the falling drop method is used to determine specific gravity in this discrete microsampling, multichannel analyzer. A digital, dual wavelength, ratio-reading spectrophotometer for use with surface reactions permits high reproducibility. The total system design includes positive patient-sample identification, central digital programming of all dispense, read-and-compute functions, a digital processor for automatic two-point calibration of each of the channels, decoding in the "plus" system and printout on the sample tag, and the electronic interface with American Standard Code for Information Interchange output for teletype and (or) computer compatibility.
Automatic System for Urine Analysis. II. Evaluation of the System
Authors: Hager C Bradley , Brown John R , Botero J M 
Published: January 2020

Abstract
The performance of a prototype instrument, "CLINILAB Automated Urine Analyzer," for automation and mechanization of urinalysis, was studied. Results of the chemical tests for which the instrument is used—pH, glucose, protein, ketone, bilirubin, and occult blood—were compared to those obtained on the same urine specimens by using "‘Bili-Labstix’ Reagent Strips." Results for specific gravity obtained by using the CLINILAB "falling drop" method were compared to those obtained by refractometer. Of 2,911comparisons between results obtained with the CLINILAB instrument and "Bili-Labstix" for the six different urinary constituents, 98% agreed as to whether the test was positive or negative. Results for pH results were considered to be in agreement if the difference was no greater than one pH unit. For 170 specimens tested, agreement was better between lower specific gravity urines than those of higher specific gravity; results generally agreed within ±0.005 specific gravity units for all urines tested.
Nonlinear Regression Analysis Approach for Determining "True" Lactate Dehydrogenase Activity in Serum with the Centrifugal Analyzer ("Rotochem")
Authors: Statland Bernard E , Louderback Allan L 
Published: January 2020

Abstract
Kinetic analyses for LD have been performed by use of a centrifugal analyzer. These analyses were performed on clinical control sera and human sera at 340 nm and 30°C. Evaluation of the data with both linear and nonlinear equations demonstrates that the exponential equation (y = C — Aebx) gives a lower value for "root mean square" (better fit) for the activity at high levels than does the linear equation (y = Ax + B). Assays done on a series of diluted sera demonstrate that a nonlinear equation approach gives a better estimate of enzyme activity than does the linear equation. The linear equation and four nonlinear functions are compared at various concentrations of NADH. The optimum concentration of NADH was found to be 0.226 mmol/liter. The best result was determined with the exponential equation.
Organic Polymer Biocompatibility and Toxicology
Authors: Bischoff Fritz 
Published: January 2020

Abstract
Adverse effects of organic polymers used for plasma extenders, tissue adhesives, bone cements, contraceptive devices, prostheses, artificial organs, food packaging, cooking, and laboratory ware are appraised. Parenteral polymer disintegration involves hydrolytic, redox, and degradation reactions. Accumulative toxicity of plasticizers, antioxidants, and monomers liberated from plastic containers warrants investigation. Main problems with heart-assist devices are clotting and blood destruction; with plasma extenders, thesaurismotic reactions; with acrylic bone glues, transitory hypotension; with artificial kidneys, loss of metabolic essentials; with silicone heart valves, uptake of lipids; with silicone chin implants, bone resorption; and with liquid silicone mammary amplification, lumpy breasts and mastitis. A polymer fume fever is linked with pyrolysis of polytetrafluoroethylene. Human solid-state carcinogenesis constitutes a calculated risk with polymer implants. In rodents, all solid polymers tested produced cancer; chemical carcinogenesis was induced by a polyvinyl chloride copolymer, vinyl chloride, polycaprolactam, liquid silicone, and some brands of polytetrafluoroethylene.
Glycosidases in Normal Human Leukocytes and Abnormalities in GM1-Gangliosidosis
Authors: Hindman Jeffrey , Cotlier Edward 
Published: January 2020

Abstract
Leukocyte enzyme assay is a valuable tool in the diagnosis of mucolipidoses and glycosphingolipidoses. Accurate resolution of the normal ranges of glycosidase activity is vital in the evaluation of both homozygotes and suspected heterozygote carriers. Activities of leukocyte β-galactosidase, α-galactosidase, α-mannosidase, β-fucosidase, β-glucosaminidase, and β-galactosaminidase were measured in a large population of normal subjects and demonstrated, within 95% confidence limits, to be normally distributed. Leukocyte glycosidases were determined in a GM1-gangliosidosis homozygote and in the heterozygous parents. A previously unreported deficiency of β-fucosidase and the well-known deficiency of β-galactosidase were demonstrated in the proband, and corresponding but less severe deficiencies of both glycosidases were found in the parents. β-Galactosidase and β-fucosidase may represent a single enzyme, unspecific for the carbon 6 of galactose. If not, the genetic defect in GM1-gangliosidosis may be more profound than has been recognized.
Evaluation of "Dexsil 300 GC" as Stationary Phase in Gas Chromatography of Triiodothyronine and Thyroxine in Human Serum
Authors: Tajuddin Mohammed , Elfbaum Stanley G 
Published: January 2020

Abstract
The N,O-dipivalyl methyl esters of triiodothyronine and thyroxine were prepared and gas chromatographed. "Dexsil 300 GC," a heat-stable polycarboranesiloxane, was used as the stationary phase. Separations were good and prompt. As little as 250 pg of triiodothyronine was detectable. Dexsil 300 GC was used satisfactorily in measuring serum triiodothyronine
Detection of Prostaglandin Induction of Erythrocyte Sickling
Authors: Johnson Malcolm , Rabinowitz Israel , Willis Anthony L , Wolf Paul L 
Published: January 2020

Abstract
Sickle cell crisis may be precipitated by pregnancy or infection, conditions in which prostaglandin concentrations can be elevated. We have investigated the effects of exogenous prostaglandins on whole blood and isolated, washed erythrocytes from patients with sickle cell anemia disease. Differential counting, light scattering, and optical absorption techniques indicate that prostaglandin E2 can induce and potentiate sickling of these cells under conditions of reduced oxygen tension. Absorption characteristics of sickle cell hemoglobin indicate that prostaglandin E2 affects hemoglobin only in an intact cell. These initial results suggest that prostaglandin E2 may represent a cofactor initiating or enhancing sickle cell crisis. A new application of a light-scattering technique appears a valuable method for continuous monitoring of the sickling process
Significance of the LP-X Test in Differential Diagnosis of Jaundice
Authors: Seidel D , Gretz H , Ruppert Claudia 
Published: January 2020

Abstract
In recent years it has been well documented that the characteristic increase in plasma lipoproteins in patients with obstructive jaundice is the result of the presence of a low-density lipoprotein (relative density 1.006-1.063 g/ml) of abnormal composition and properties. This abnormal lipoprotein has been designated "LP-X." The development of a simple immunologic test system for determining LP-X provides the basis for a new clinical chemical test that is of use in the differential diagnosis of jaundice. In this study, 2680 LP-X determinations were performed on 1481 subjects: 1309 patients with or without liver disease, and 172 healthy volunteers. Statistical analysis of this series revealed a power of 0.99 and a specifity of 0.98 to demonstrate or exclude cholestasis. In this regard the new test is superior to other blood-chemical assessments. It was never positive in patients without liver disease. However, the LP-X test alone is not adequate to distinguish between intrahepatic cholestasis and extrahepatic biliary obstruction
A Referee Method for the Determination of Total Calcium in Serum
Authors: Cali J Paul , Bowers G N , Young D S 
Published: January 2020

Abstract
The first referee method of analysis (a method of known accuracy) in clinical chemistry has been developed through the cooperation of scientists from the National Bureau of Standards and eight clinical chemistry laboratories. Subject to some limitations discussed in the text, calcium in serum can be determined by the referee method to within ±2% of the "true or absolute" value. The complete protocol, based on an atomic absorption spectrometric procedure, is described in detail.
Residual Fluorescence as an Index of Purity of Reduced Nicotinamide Adenine Dinucleotide
Authors: Howell Barbara F , Margolis Sam , Schaffer Robert 
Published: January 2020

Abstract
Determination of fluorescence remaining after reduced nicotinamide adenine dinucleotide (NADH) has reacted with excess acetaldehyde in the presence of alcohol dehydrogenase (EC 1.1.1.1) is useful as a criterion of NADH purity when used in conjunction with other methods for determining purity such as the rate of reaction, the ratio of ultraviolet absorbances at 260 nm and 340 nm, the color, and the chromatographic homogeneity of the preparation. Measurement of residual fluorescence monitors the enzymatically inactive material which absorbs at 340 nm. The specific optical rotations of NADH at several wavelengths are also reported.
Preparation and Properties of a Cholesterol Oxidase from Nocardia sp. and Its Application to the Enzymatic Assay of Total Cholesterol in Serum
Authors: Richmond W 
Published: January 2020

Abstract
I describe the characterization, extraction, and purification of a cholesterol:oxygen oxidoreductase (EC 1.1.3.6) from Nocardia sp. This enzyme catalyzes oxidation of cholesterol to Δ4-choIestenone, with production of hydrogen peroxide. It is very stable, active over a wide pH range, and has a Km of 1.4 x 10-5 mol/ liter. It is highly specific for Δ4- or Δ5-3β-hydroxycholestanes, and may be applied to the assay of serum total cholesterol. In the procedure presented here, hydrogen peroxide is measured by reaction with quadrivalent titanium and xylenol orange. This constitutes a one-enzyme assay with stable reagents, which does not require protein precipitation and is not subject to interference from hemoglobin or bilirubin.
Plasma Renin Activity: A Method for Rapid Screening by Radioimmunoassay and a Comparison of Two Commercially Available Kits
Authors: Goldberg Samuel D , Spierto F W 
Published: January 2020

Abstract
Twenty to thirty percent of patients with essential hypertension have subnormal plasma renin activity (PRA) and lower incidences of stroke and myocardial infarction. NaCl intake influences PRA, which should thus be compared with 24-h urinary sodium excretion. Because such specimens are difficult to collect accurately, we investigated the relation between PRA and sodium in casual (i.e., untimed) urine specimens and found none. However, PRA and urinary Na/creatinine ratio are inversely correlated for casual specimens. This method is useful for screening individuals whose salt intake is low. Mean PRA, measured by the Schwarz-Mann procedure, was 0.62 ± 0.12 (SD) ng/ml per hour for 59 normotensive volunteers, 35% lower by the Squibb procedure.
Radioimmunoassay of Plasma Digoxin, with Use of Iodinated Tracer
Authors: Horgan E D , Riley W J 
Published: January 2020

Abstract
A radioimmunoassay of plasma digoxin is described, in which iodine-125 labeled digoxin is used as tracer. The assay is rapid, precise, sensitive, and specific, and can readily cope with a large number of plasma samples. The use of iodinated digoxin increases assay sensitivity, shortens counting time, and eliminates the problems associated with liquid scintillation counting. The performance of this method is compared with that of other assay systems involving the use of tritiated compounds.
Identification of Lithocholic Acid and Measurement of Other Bile Acids in Serum of Healthy Humans
Authors: Pellizzari E D , O’Neil F S , Farmer R W , Fabre L F 
Published: January 2020

Abstract
Combined gas—liquid chromatography mass-spectroscopy was used to identify lithocholic acid and confirm the presence of other bile acids in serum of a healthy fasting subject. GLC was used to measure deoxycholic (DCA), chenodeoxycholic (CDCA), and cholic (CA) acids in sera. Before analysis, serum bile acids were purified by (a) enzymatic hydrolysis of conjugates, (b) anion-exchange chromatography, (c) alumina adsorption chromatography, and (d) GLC of methyl trifluoroacetate derivatives on QF-1. Recovery of bile acids (determined by adding [14C]cholic acid to each sample), after correction for loss during purification, was 63-83%. Fasting values for 28 healthy subjects were: 1.4-46.5 (av 7.1), 1.4-49.6 (12.8), and 1.4-46.0 (16.0) µg/100 ml for DCA, CDCA, and CA, respectively. Traces of lithocholic acid were found in 20% of the cases studied. The smaller ranges we found for serum bile acid concentrations in a healthy fasting population are attributed to the careful health-screening of subjects and improved techniques.
Nonspecific Interferences in the Fluorometric Determination of Plasma Cortisol
Authors: Koch Thomas R , Edwards Leila , Chilcote Max E 
Published: January 2020

Abstract
The popular Mattingly [J. Clin. Pathol. 15, 374 (1962)] fluorometric assay for plasma cortisol is shown to give rise to falsely high values when performed with the recommended optical arrangement. By exciting at 470 nm, however, results are obtained that correlate well (r = 0.972) with those of competitive protein binding. The source of the interference is not identified, but it is related to both the dichloromethane used for extraction and the nature of the individual plasma sample.
Urinary Guanidinoacetate / Guanidinosuccinate Ratio: An Indicator of Kidney Dysfunction
Authors: Sasaki Masahide , Takahara Kihachiro , Natelson Samuel 
Published: January 2020

Abstract
Five formerly unidentified peaks in the column chromatogram of urinary compounds giving the Sakaguchi reaction appear to be proteins or polypeptides containing arginine. If these substances, salts, and creatine are first removed, then guanidinoacetate (GAA), guanidinosuccinate (GSA), and creatine are readily measured in urine. This technique was applied to the urine of 17 healthy men and 10 healthy women, GAA and GSA being measured by the Sakaguchi reaction (after they were separated by electrophoresis) and creatine by the diacetyl reaction. Creatine and GAA values differ for men and women when corrected for differences in body weight. In mg/24 h/kg body weight, the respective excretions for men and women were: creatine, 0.83 and 1.98; GAA, 0.71 and 1.22. No significant sex-related differences were found for GSA (men, 0.18; women, 0.25) or creatinine (men, 24.7; women, 22.8). The GSA/GAA excretion ratio for healthy men and women was 0.25 and 0.20, respectively. For those with abnormally high blood urea nitrogen and creatinine concentrations, this ratio rose to values ranging from 1.8 to 24, with no overlap with normal. This ratio is evidently a sensitive indicator of kidney function.
Nephelometric Studies of the Precipitin Reaction: A Model System for Specific Protein Measurements
Authors: Killingsworth L M , Savory John 
Published: January 2020

Abstract
Light-scattering studies have been carried out on an immunochemical system that serves as a model for specific protein determinations in biological samples. The influence of antigen/antibody ratio, salts, urea, pH, temperature, and excitation wavelength are presented. Of significance is the finding that ions, particularly F-, increase the rate of formation of and the light scattering from the antigen-antibody complexes.
Improved Method for Specific Determination of Creatinine in Serum and Urine
Authors: Mitchell Robert J 
Published: January 2020

Abstract
A simple method has been developed for measuring creatinine in serum and urine. Small, fast-flowing cation-exchange columns are used to separate creatinine from interfering substances. The creatinine is eluted and determined with the Jaffe reaction. The results agree well with those for the procedure in which Lloyd's reagent is used.
Fecal Nickel Excretion by Healthy Adults
Authors: Horak Eva , Sunderman F William 
Published: January 2020

Abstract
Nickel was measured by atomic absorption spectrometry in three-day collections of feces from healthy hospital workers (age 22-65) who had lived for more than a year in Hartford, Connecticut. None of the 10 subjects (4/♂ , 6/♀.) had occupational exposure to nickel. Fecal nickel averaged 3.3 µg/g (wet weight); SD, ±0.8; and range, 2.1 to 4.4 µg/g. Corresponding figures on a dry-weight basis were 14.2 µg/g; SD, ±2.7; and range, 10.8 to 18.7 µg/g. The fecal excretion of nickel averaged 258 µg/day (SD, ±126; range, 80 to 540 µg/day). Fecal excretion is evidently the major route for elimination of nickel from the human body. Comprehensive evaluations of environmental or occupational exposures to nickel should also include analyses of nickel in serum, urine, and hair.
Microdiffusion Method for Estimation of Cyanide in Whole Blood and Its Application to the Study of Conversion of Cyanide to Thiocyanate
Authors: Pettigrew A R , Fell G S 
Published: January 2020

Abstract
A microdiffusion technique has been used to separate and concentrate the nanomole amounts of cyanide in whole blood, and to permit its simplified colorimetric estimation (1). With this technique cyanide was measured in whole blood from normal smokers, normal nonsmokers, and patients suffering from tobacco amblyopia. Cyanide was also measured in whole blood from vitamin B12-deficient and normally fed Wistar rats. From the experimental animal results and results from patients, it is suggested that a more suitable index of cyanide exposure may be the alteration of plasma thiocyanate rather than the direct determination of whole blood cyanide.