bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of Serum Cholinesterase Fluoride Variants by Differential Inhibition in Tris and Phosphate Buffers
Authors: Garry Philip J , Owen George M , Lubin A Harold
Published: January 2020

We describe a useful technique to identify "fluoride-resistant" serum cholinesterase variants (E1uE1f and E1fE1f) by using the method of Garry to detect "atypical" variants and to measure serum cholinesterase activity [Clin. Chem. 17, 192 (1971)]. With butyrylthiocholine as substrate, sodium fluoride is used as a differential inhibitor in both Tris and phosphate buffer systems (50 mmol/liter, pH 7.4, 25°C). Fluoride inhibition values are plotted on two-dimensional graph paper, Tris plus sodium fluoride vs. phosphate plus sodium fluoride. Inhibition values for the "fluoride-resistant" and "atypical" variants are located in specific quadrants, which permits unequivocal identification of each variant. Examination of 836 Caucasian preschool children revealed a gene frequency of 0.0066 for the "fluoride" variant. No "fluoride-resistant" variants were found in 168 Negro preschool children examined.
Automated Fluorometric Procedure for Measurement of Creatine Phosphokinase Activity
Authors: Rokos J A S , Rosalki S B , Tarlow D
Published: January 2020

An automated procedure is described for measuring creatine phosphokinase activity (in serum, although the technique is adaptable) with the Technicon AutoAnalyzer. Creatine, formed by the action of the enzyme on phosphocreatine and adenosine diphosphate, is measured by the fluorescence of its reaction product with alkaline ninhydrin solution. Thirty determinations can be made per hour, and only 0.2 ml of sample is required.
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

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

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, <5 mg/dl; cholesterol, 53 ± 12.2 mg/dl; diglycerides, <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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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.
Trace-Element Contamination in Biopsies of the Liver
Authors: Versieck J , Speecke A , Hoste J , Barbier F
Published: January 2020

Contamination by trace elements during collection of liver biopsies has been investigated qualitatively and quantitatively. Menghini needles for percutaneous liver biopsy and disposable surgical blades were irradiated in a nuclear reactor until their constituents had a high specific activity. Sampling of liver biopsies was simulated in vitro with use of the irradiated instruments. Under these experimental conditions, radioactivity found in the samples corresponds to contaminations as may be expected in clinical practice. The results demonstrate that needle biopsies are heavily contaminated by numerous trace elements and unsuitable for trace-element analysis. Liver biopsies taken during laparotomy, with a steel surgical blade, are markedly less contaminated but still not acceptable for determinations of some trace elements, especially chromium and nickel.
Determination of Serum and Urinary Phenylalanine by Gas Chromatography
Authors: Shihabi Z K , Summer G K
Published: January 2020

Phenylalanine in serum and urine was determined by gas chromatography after it was converted, by action of nitrous acid, to the corresponding hydroxy acid, phenyllactic acid. After extraction with ether, the phenyllactic acid was derivatized with bis(trimethylsilyl)trifluoroacetamide under mild conditions, and the product was injected directly into the gas chromatograph. The precision of the method was verified by recovery studies and by comparison with the results of quantitative analysis of phenylalanine on an amino acid analyzer. Urine specimens from normal infants and children and from patients with phenylketonuria were analyzed by this method to show that the procedure is applicable to diagnosis of the disorder.
Intercomparison of Results Obtained with Five Commercial Diffusion Plates Supplied for Quantitation of Immunoglobulins
Authors: Hosty Thomas A , Hollenbeck Mary , Shane Shelia
Published: January 2020

Results obtained with five commercial sources of quantitative immunoglobulin plates for IgG, IgA, and IgM varied widely. Preliminary evidence suggests that the international reference serum supplied by the National Institute of Health should be used to standardize commercial reference sera, because the labeled values for immunoglobulins on such sera are of questionable reliability.
Comparison of Results for Three Methods of Hemoglobin S Identification
Authors: Hicks Edward J , Griep John A , Nordschow Carleton D
Published: January 2020

We present comparative results of three diagnostic tests for identification of hemoglobin S, performed on specimens from a total of 4,739 persons. A simple, rapid, and economical procedure for cellulose acetate electrophoresis was more efficient than either the "Sickledex" test (a dithionite test) or the metabisulfite reduction test. This is an important consideration as a minimum requirement for effective therapy and genetic counseling. We propose electrophoresis of hemoglobin on cellulose acetate as a primary screening procedure—with verification of positive samples by solubility tests—and discuss its feasibility.
Concentrations in Serum and Urinary Excretion of Guanidine, 1-Methylguanidine, and 1,1-Dimethylguanidine in Chronic Renal Failure
Authors: Stein Israel M , Micklus Michael J
Published: January 2020

Guanidine (G), 1-methylguanidine (MG), and 1,1-dimethylguanidine (DMG) have long been implicated as uremic "toxins." A method has been developed for determining G, MG, and DMG in serum and urine. Specimens were chromatographed on carboxylate resin, with use of 1 molar NaOH, and quantitated colorimetrically with a modification of the Voges— Proskauer reaction. The mean values for G and MG in the serum of uremic patients were 0.3 and 0.4 mg per liter, respectively. DMG was not detected. Although the urinary excretion of MG is significantly increased in renal failure, the concentrations of G, MG, and DMG in serum are not markedly increased, and it is therefore unlikely that G, MG, or DMG contribute to the toxic manifestations of the uremic syndrome.
Determination of Total Organic Acids in Urine by Extraction with Organic Solvents
Authors: Kesner Leo , Yao Tsai-Tse , Dell Ralph B
Published: January 2020

Metabolic carboxylic acids are extracted, with a mixture of equal volumes of t-amyl alcohol—chloroform, from an acidified sample of as little as 200 µl of urine that has been adsorbed to a short column of silica gel. Total acid in the extract is measured by titration with tetramethylammonium hydroxide (10 mmol/liter) to a phenolphthalein end point. There is no interference from protein, creatinine, creatine, bicarbonate, or amino acids, and no pretreatment of the sample is required. Results compared well (r = 0.94) with those obtained by the Palmer—Van Slyke method for total organic acids. This procedure should prove useful as a simple, rapid screening test for those metabolic disturbances and inborn errors of metabolism characterized by increased excretion of organic acids.
Radioimmunoassay of Human Chorionic Somatomammotropin in Serum, Amniotic Fluid, and Urine
Authors: Moser Russell J , Hollingsworth Dorothy R
Published: January 2020

A method is described for measurement of human chorionic somatomammotropin (HCS) by use of a double-antibody technique, for concentrations ranging from 2 ng/ml to 20 µg/ml. The cross-reactive characteristics of rabbit anti-human HCS serum No. CT 3399 from NIAMD are explored. A dilution plan is presented utilizing a standard curve from 0.75 to 80 ng/ml. Concentrations (mean and ranges) for HCS in maternal serum (evaluated every four weeks during pregnancy), umbilical cord serum, serum from babies, amniotic fluid, and urine are given.
Modified Pisano Method for Estimating Urinary Metanephrines
Authors: Gupta R N , Price D , Keane P M
Published: January 2020

The Pisano method [Clin. Chim. Acta 5, 406 (1960)] for estimating urinary metanephrine, used in the screening of hypertensive persons for pheochromocytoma, has been modified by replacing ion-exchange chromatography with differential solvent extraction. An internal standard is incorporated to correct for procedural losses. Interference from some related compounds is negligible. Normal-range values obtained for various age groups by the present method compare well with those obtained by Pisano’s procedure, but are higher than values reported for more specific methods.
Direct Measurement of Chloride in Sweat with an Ion-Selective Electrode
Authors: Margaret LaVerne Szabo, , Kenny A , Lee Winnie
Published: January 2020

The use of a specific ion electrode for measuring sweat chloride has not been widely accepted because of poor precision and occasional falsely elevated chloride concentrations. We have studied this technique by using the Orion sweat-chloride instrument, and have eliminated these problems by modifying the methodology. An insufficient amount of sweat for determination with the electrode was responsible for both the imprecision and random inaccuracies. The following modifications eliminated these problems: (a) We freshly saturate felt pads with a solution of, per deciliter, 400 mg of pilocarpine nitrate and 1 g of NaHCO3 to replace the electrolyte pads supplied by the Orion Co. (b) The timed iontophoresis period commences after the meter indicates conduction of adequate current. (c) After iontophoresis, sweat is collected for 10 min under a plastic cap held over the induction area. Then chloride concentration is measured with the electrode. With these improvements in technique, the revised procedure should be as reliable as reference methodologies.
Evaluation of S-Benzyl-L-cysteine-4'-nitroanilide as a Substrate for Serum Cystine Aminopeptidase
Authors: Tovey J E , Dawson P J G , Fellowes K P
Published: January 2020

Under appropriate conditions, S-benzyl-L-cysteine-4'-nitroanilide is rapidly hydrolyzed by serum cystine aminopeptidase. The enzyme may be estimated kinetically by determining the rate of liberation of 4-nitroaniline. A simple automated procedure has been devised, and 50 samples of pregnancy sera can be analyzed per hour by use of the LKB 8600 Reaction Rate Analyzer. The correlation coefficient between results of this method and those obtained with L-cystine-di-4'-nitroanilide as substrate was 0.97.
Technical Improvements in Measurement of L-Aspartate: 2-Oxoglutarate Aminotransferase Activity in Serum by Diazonium Salt Coupling
Authors: Morin Leo G , Prox Jerome
Published: January 2020

An improved diazonium coupling procedure is described for measurement of L-aspartate: 2-oxoglutarate aminotransferase (EC 2.6.1.1, formerly termed glutamic oxalacetic transaminase) activity in serum. A relatively pH-stable dye, 5-chloro-2-methoxyaniline-1-diazonium chloride (Fast Red RC) is used, with dimethylformamide and methanol to enhance and stabilize color development. A 15-min incubation is part of the procedure, and color development stabilizes within 5 min.
Application of Inductively-Coupled Plasma Excitation Sources to the Determination of Trace Metals in Microliter Volumes of Biological Fluids
Authors: Kniseley Richard N , Fassel Velmer A , Butler Constance C
Published: January 2020

The inductively coupled plasma is a promising excitation source for the simultaneous multielement determination of trace (nanogram per milliliter) elements in biological fluids. As little as 25 µl of sample fluid (whole blood, serum, or plasma) has been used, with essentially no sample preparation. This technique offers significant advantages over other methods requiring considerable sample handling that may greatly increase the danger of contamination or loss of trace constituents. The precision of the method is typically ±3 to 5%. Because this is an emission spectroscopic technique, a multichannel direct-reading spectrometer allows simultaneous multielement analyses to be made on microliter samples.
Development and Application of a Rapid Cell Sorter
Authors: Hulett H R , Bonner W A , Sweet R G , Herzenberg L A
Published: January 2020

We have further developed our rapid cell analyzer and sorter, so that we can now identify and separate functionally distinct groups of viable cells that have, or can be made to have, either different fluorescence intensities, different light-scattering characteristics, or different combinations of these two variables. In this instrument, cells are observed individually in suspension in the central stream of a very small coaxial liquid jet, as they pass through two laser beams. The jet is later broken into uniform droplets, and those droplets containing the desired cells are charged electrically and then deflected in an electric field. Several thousand cells can be processed per second. Enrichment factors of up to 500 and final purities and viabilities of 90% or more can be routinely achieved. Cell populations present in fractions as small as 1 in 105 or less can be identified. Radioisotope analytical techniques indicate that only a few thousand fluorescent molecules need be present on a cell for it to be detected. The instrument is described and various modes of operation and biological and clinical applications are discussed briefly.
Clinical Laboratory Use of Differential Light Scattering. I. Antibiotic Susceptibility Testing
Authors: Stull V R
Published: January 2020

Differential light scattering (DLS) provides a quantitative representation of bacterial cells in much greater scope and detail than that provided by microscopy and turbidimetry. The information content of the DLS pattern may prove sufficient to provide a basis for most of the tests performed in the clinical bacteriological laboratory. The first application that we have implemented is an automated system with laser illumination, "Differential III," for rapidly determining susceptibility of bacteria to antibiotics. Its high sensitivity detects physiological changes in the generation of cells that metabolize the drugs. Thus the test can be performed in a relatively short time (1.5 h) and at a rate of about 15 specimens per hour. Extensive laboratory testing has been done and hospital evaluation is under way. Data showing the degree of correlation of the Differential III results with other methods are presented. Other applications of DLS in the clinical laboratory are discussed.
Rapid Radioimmunoassay of Triiodothyronine
Authors: Sekadde Christine B , Slaunwhite W Roy , Aceto Thomas
Published: January 2020

The method used in this report is based on the immunological production of a specific antisera to triiodothyronine (T3) in rabbits. Conducted at 4 °C, the radioimmunoassay requires three to five days to complete. Hoping to speed this assay, we investigated the influence of time, temperature, and pH. Incubation at 37 °C and pH 8.0 for 30 min did not deleteriously affect either precision, specificity, reproducibility, or accuracy. Bound and unbound T3 were separated in 10 min by adding polyethylene glycol ("Carbowax 6000") at 0-4 °C. T3 was prevented from binding to thyroxine-binding globulin by the addition of 8-anilino-1-naphthalene sulfonic acid. To minimize the differences in protein concentration between standards and unknowns, we added T3-free serum to all standards. Thus, a simplified and convenient method is described for measurement of T3 that is suitable for clinical use because it is simpler and faster than previously reported methods.
Standard Reference Materials: Standard Quartz Cuvettes for High-Accuracy Spectrophotometry
Authors: Mavrodineanu R , Lazar J W
Published: January 2020

Accurate knowledge of lightpath and parallelism of cuvettes used in spectrophotometry are indispensable parameters that must be determined when accurate transmittance measurements of liquid materials are considered. A description is given of the design and techniques developed at NBS for production of quartz cuvettes (SRM 932) having a nominal radiation pathlength of 10 mm ± 0.03 mm. For each cuvette, pathlength and parallelism are certified with an uncertainty of ±0.0005 mm. The method and instrumentation used to determine these parameters are also described.
A Modified Procedure for Evaluation of the Lecithin/Sphingomyelin Ratio in Amniotic Fluid
Authors: Coch Emily , Meyer John S , Goldman Gordon , Kessler Gerald
Published: January 2020

We describe several modifications of the procedure originated by Gluck et al. [ Amer. J. Obstet. Gynecol. 109, 440 (1971)] for evaluation of amniotic fluid lecithin/sphingomyelin (L/S) ratios. The acetone-precipitation step is eliminated, resulting in a faster extraction procedure and higher concentrations of phospholipids. For faster thin-layer chromatography, we use silica gel-impregnated sheets of glass-fiber and a modified solvent system. For spot detection we use a noncorrosive bismuth subnitrate reagent that is specific for lecithin and sphingomyelin, and an iodine vapor method to confirm the L/S ratio. The bismuth spray also detects significant specimen contamination by phospholipids from plasma or erythrocytes. The L/S ratio is evaluated by visually comparing the relative size and color intensity of the lecithin and sphingomyelin TLC spots. An L/S ratio of 5 or more is consistent with mature pulmonary function and an L/S ratio of less than 2 suggests fetal pulmonary immaturity.
Standardization in Bilirubin Assays: Evaluation of Selected Methods and Stability of Bilirubin Solutions
Authors: Doumas Basil T , Perry Billy Wayne , Sasse Edward A , Straumfjord Jon V
Published: January 2020

Because of the inaccuracy of bilirubin (BIL) determinations, we have investigated some sources of error associated with the most commonly used methods. Inadequate standardization appears to be the most common error. BIL standards in either human serum albumin (HSA), bovine serum albumin (BSA), or pooled human serum were analyzed by these methods. Molar absorptivities (ε) of azobilirubin by the Jendrassik—Gróf procedure were practically identical in all three protein bases. The Meites—Hogg and Malloy—Evelyn methods gave substantially higher ε values with BIL in serum than with BIL in either HSA or BSA. The precision of all methods was good, but best with the Jendrassik—Gróf procedure. BIL standards can be prepared with good reproducibility (CV <0.5%). Standards deteriorate appreciably at -23 °C but are stable at -70 °C. Our data indicate a need for improved commercial BIL controls.
Increased Discontinuation Rates of Anti-TNF Therapy in Elderly Inflammatory Bowel Disease Patients
Authors: de Jong M E , Smits L J T , van Ruijven B , den Broeder N , Russel M G V M , Römkens T E H , West R L , Jansen J M , Hoentjen F
Published: January 2020

Background and Aims

There is paucity of data on safety and efficacy of anti-tumour necrosis factor [TNF] in elderly inflammatory bowel disease [IBD] patients. We aimed to compare the long-term treatment failure rates and safety of a first anti-TNF agent in IBD patients between different age groups [<40 years/40–59 years/≥60 years].

Methods

IBD patients who started a first anti-TNF agent were identified through IBDREAM, a multicentre prospective IBD registry. Competing risk regression was used to study treatment failure, defined as time to drug discontinuation due to adverse events [AEs] or lack of effectiveness, with discontinuation due to remission as a competing risk.

Results

A total of 895 IBD patients were included; 546 started anti-TNF at age <40 [61.0%], 268 at age 40–59 [29.9%], and 81 at age ≥60 [9.1%]. Treatment failure rate was higher in the two older groups (subhazard rate [SHR] age ≥60 1.46, SHR age 40–59 1.21; p = 0.03). The SHR in the elderly [>60] was 1.52 for discontinuation due to AEs and 1.11 for lack of effectiveness. Concomitant thiopurine use was associated with a lower treatment failure rate (SHR 0.78, 95% confidence interval [CI] 0.62–0.98, p = 0.031). Serious adverse event [SAE] rate, as well as serious infection rate, were significantly higher in elderly IBD patients [61.2 versus 16.0 and 12.4 per 1000 patient-years, respectively] whereas the malignancy rate was low in all age groups.

Conclusions

Elderly IBD patients starting a first anti-TNF agent showed higher treatment failure rates, but concomitant thiopurine use at baseline was associated with lower failure rates. Elderly IBD patients demonstrated higher rates of SAEs and serious infections.
Understanding influenza vaccination among Portuguese elderly: the social ecological framework
Authors: Machado Ausenda , Santos Ana João , Kislaya Irina , Larrauri Amparo , Nunes Baltazar
Published: January 2020

This study intended to identify and quantify the social ecological model (SEM) levels associated to seasonal IV uptake in the Portuguese elderly population. Data from the 2014 National Health Survey was restricted to individuals aged 65+ years (n = 5669). Twenty-three independent variables were allocated to the SEM levels: individual, interpersonal, organizational, community and policy. Sex stratified and age adjusted analysis using Poisson regression were performed for each level and for a fitted full model. Relative reduction in pseudo R magnitude measured marginal contribution of each level. For men and women, older groups (85+ vs. 65–69; men, PR = 1.59 and women, PR = 1.56); having 3+ chronic conditions (men, PR = 1.39 and women, PR = 1.35); previous 4 weeks GP and outpatient visits were associated to higher IV uptake. For men, only 2 SEM levels were associated (individual and organizational) while for women the community level was also relevant. Main marginal contribution came from individual (17.9% and 16.3%) and organizational (30.7% and 22.7%) levels. This study highlights the importance of individual characteristics, access and use of health care services for the IV uptake and the sex differential behaviour.
Effects on general health associated with beach proximity in Barcelona (Spain)
Authors: Ballesteros-Olza Mario , Gracia-de-Rentería Pilar , Pérez-Zabaleta Amelia
Published: January 2020

Health benefits of blue spaces have been less studied compared with other urban natural environments. As a type of blue space, beaches are also affected by this lack of evidence, despite their cultural and economic importance in lots of coastal regions all over the world. Based on secondary health data from 3192 participants of the Health Survey of Barcelona 2016, we conducted a logit regression analysis to explore the relationship between people’s general health and beach proximity from their dwelling place, controlling for several health determinants. Our main results suggested that having good general health was less likely for a 1-km increase in the linear distance to the closest beach from people’s dwelling places (OR: 0.93; 95% CI: 0.87, 1.00). Moreover, the probability of having good general health was 45% higher for people living in the first 2 km from the beach (OR: 1.45; 95% CI: 1.01, 2.09), relative to those living >5–10 km from it. Also, these health effects were stronger for people with a low family income. These findings contribute to grow the currently small body of research related to health benefits of beach spaces. Likewise, they encourage fostering the use of these spaces for health promotion in cities, as well as protecting them and improving their accessibility and safety. Further research should lean towards the underlying causes of these health benefits linked to people’s exposure to beach spaces.
Influencing the social impact of financial systems: alternative strategies
Authors: Sim Lee-Anne
Published: January 2020

The social impact of the global financial crisis brought global and domestic financial systems into public focus. While over the last ten years governments have introduced a range of regulatory reforms, there are still low levels of public trust in financial sectors, and academics continue to express their concerns about financial systems and their desire for more influence. This is particularly the case for those framing their evaluation of the quality of financial systems in terms of social values. This article offers those seeking more influence over the social values of financial systems, a fresh perspective on their available strategic options for influencing outcomes. It argues that they should consider strategies aimed at making allies of financial sectors and regulators in influencing change. The main advantage of these alliance strategies is that they address key constraints to influence, as identified in existing scholarship, which are difficult to relax because they are tied to features inherent in financial systems. By addressing these constraints, alliance strategies could increase the likelihood that financial system outcomes align more closely with their preferred social values.