bluuebunny/crossref_metadata_2025_split huggingface dataset:
Serum Cholinesterase Variants: Examination of Several Differential Inhibitors, Salts, and Buffers Used to Measure Enzyme Activity
Authors: Garry Philip J 
Published: January 2020

Abstract
Dibucaine, used as a differential inhibitor with acetyl-, propionyl-, and butyrylthiocholine as substrate, clearly identified the "usual" and "atypical" serum cholinesterases. Succinylcholine was also used successfully as a differential inhibitor with butyrylthiocholine as substrate. Sodium fluoride, used as a differential inhibitor, gave conflicting results, depending on whether Tris or phosphate buffer was used in the assay. Mono- and divalent cations (NaCl, KCl, MgCl2, CaCl2, and BaCl2) activated the "usual" and inhibited the "atypical" enzyme at low concentrations. The "usual" enzyme had the same activity in 0.05 mol of Tris or phosphate buffer per liter, while the heterozygous and "atypical" enzymes showed 12 and 42% inhibition, respectively, when assayed in the phosphate buffer. Kinetic studies showed the phosphate acted as a competitive inhibitor of "atypical" enzyme. Km values, determined for "usual" and "atypical" enzymes, were 0.057 and 0.226 mmol/liter, respectively, with butyrylthiocholine as substrate.
Effect of Triton X-100 on Electrophoretic Mobility of Red Blood Cell Ghosts from Normal Individuals and Patients With Tay—Sachs Disease
Authors: Pourfar M , Levy S 
Published: January 2020

Abstract
The negative surface charge of red blood cell ghosts and their anodal electrophoretic migration are largely due to their sialic acid moiety. The RBC of patients with Tay—Sachs disease are thought to contain increased amounts of sialic acid. Electrophoretic mobility and ganglioside content of RBC ghosts were compared in four patients with Tay—Sachs disease and eight normal controls. There was no measurable difference in electrophoretic mobility on cellulose acetate or acrylamide gel. The sialic acid content of lyophilized RBC ghosts was about the same for samples from both patients and controls. The nonionic detergent, Triton X-100, interacts with the ghost glycolipoprotein, causing a reversal of migration, both on cellulose acetate and moving-boundary electrophoresis. Acrylamide gel, by its sieving effect, disrupts the complex, which then migrates anodally again.
Manual Colorimetric Methods for Pseudocholinesterase and Red Cell (True) Cholinesterase
Authors: MacQueen J , Plaut D , Borges J , Anido G 
Published: January 2020

Abstract
This report describes both an improved version of Garry and Routh’s colorimetric assay for serum pseudocholinesterase [Clin. Chem. 11, 91 (1965)] and a variation of this method for use in measuring cholinesterase in red cells. These procedures require either 0.1 ml of serum (diluted 10-fold) cr 0.1 ml of packed, heparinized erythrocytes (diluted 100-fold). The reaction involves the hydrolysis of acetylthiocholine to acetic acid and thiocholine, and the quantitation of the thiocholine with 5,5'-dithiobis-2-nitrobenzoic acid. In the procedure, the sample of diluted serum or cells is added to the combined buffer—color-substrate reagent at 37°C. After incubation for 10 min, quinidine sulfate is added to retard the reaction and the color is read at 450 nm. Blanks are required with each red cell sample, but not for sera. The results correlate well with those obtained by Michel’s standard ΔpH assay, Kalow’s benzoylcholine uv-rate reaction, Caraway’s colorimetric procedure, and Ellman’s colorimetric rate reaction. A method for determination of dibucaine-inhibited serum pseudocholinesterase is also described.
Detection of Phenylketonuric Heterozygotes
Authors: Jackson Sanford H , Hanley William B , Gero Terese , Gosse G D 
Published: January 2020

Abstract
Estimation of plasma phenylalanine and tyrosine by an abridged (30 min) column chromatography procedure was assessed. Plasma phenylalanine and tyrosine concentrations, determined in 112 phenylketonuric obligate heterozygotes and in 88 normal controls, did not differ significantly from other reported series in which the data were obtained by column chromatography. All these series were combined and analyzed statistically. Phenylketonuric heterozygotes can be detected with a high degree of discrimination by the ratio of phenylalanine to tyrosine in the plasma of the fasting subject, in combination with the plasma phenylalanine concentration.
Increased AutoAnalyzer Dialysis of Calcium and Magnesium in Presence of Protein
Authors: Lott John A , Herman Thomas S 
Published: January 2020

Abstract
We have studied calcium and magnesium determination with the AutoAnalyzer, using dialysis, and measurement by atomic absorption spectrophotometry. The fraction of calcium and magnesium that dialyzes is proportional to the protein content of the sample; therefore an error is introduced when aqueous solutions of calcium or magnesium salts are used as standards. Apparently, the presence of proteins causes increased dialysis of Ca+2 and Mg+2.
Use of an Anion-Exchange Column to Determine Serum Iron-Binding Capacity
Authors: Lehmann H Peter , Kaplan Alex 
Published: January 2020

Abstract
A rapid procedure is described for determining total iron-binding capacity (TIBC) by use of a small, disposable resin column. Serum is saturated with excess ferric citrate, and iron not bound to protein is then removed by passing the mixture through the column of anion-exchanger. Transferrin-bound iron in the effluent, the TIBC, is determined colorimetrically (AutoAnalyzer), with 2,4,6-tripyridyl-1,3,5-triazine as color reagent. The percentage saturation with iron may be obtained from colorimetric measurement of original serum iron and the TIBC, or by radioactive counting if 59Fe is incorporated in the ferric citrate used to saturate the serum. Our method is compared with the MgCO3 precipitation technique for the removal of excess iron after saturation and to an ultrafiltration technique in which protein-bound iron is retained by a membrane and the filtrate analyzed for unbound iron, thus obviating absorbents in the determination of TIBC. Results from the resin-column and ultrafiltration procedures correlated well, whereas those from the MgCO3 method were consistently lower and more erratic.
Sephadex Adsorption of Bilirubin from Neonatal and Adult Serum
Authors: Kapitulnik J , Blondheim S H , Kaufmann N A 
Published: January 2020

Abstract
The bilirubin (BR)-binding capacity of albumin in serum from cord blood, as estimated by Sephadex gel filtration, is less than that of adult serum. The binding site at which BR is tightly bound by albumin in pools of infant serum was saturated at an average BR/albumin molar ratio of 0.66, while in adult serum the ratio was 1.00. With further increase in BR concentration, albumin of infant serum bound BR less than that of adult serum. These findings appear to have clinical significance with respect to the danger of BR encephalopathy in icteric infants.
Column-Chromatographic Analysis of Naturally Fluorescing Compounds: II. Rapid Analysis of Indoleacetic Acid and 5-Hydroxyindoleacetic Acid in Biological Samples
Authors: Chilcote D D 
Published: January 2020

Abstract
A previously described [Clin. Chem. 18, 778( 1972)] chromatographic separation and fluorometric system has been adapted to determination of 5-hydroxyindole-3-acetic acid and indole-3-acetic acid in body fluids and biological extracts. A strong anion-exchange resin, "Aminex A-27," is used. The indoleacetic acids are eluted at 60°C with a single ammonium acetate-acetic acid buffer. No gradient programming or post-column reaction designed to enhance the fluorescence of the desired compounds is necessary. The sensitivity of the detector allows analysis of 100 ng of each acid in the sample loaded onto the column.
Quantitation of Plasma Aldosterone by Radioimmunoassay
Authors: Cyr M J St , Sancho J M , Melby J C 
Published: January 2020

Abstract
Aldosterone antibodies were produced by injecting sheep with the albumin conjugate of aldosterone-18,21-dihemisuccinate. Conditions optimal for an accurate, reproducible assay with this antiserum were determined experimentally. Aldosterone is extracted from plasma and isolated by a single thin-layer chromatographic system before the immunoassay is performed. Normal plasma aldosterone in supine subjects is 8.6 ± 3.8 ng/100 ml; after 2 h in the upright position, 18.3 ± 9.5 ng/100 ml. Eighteen months of experience with the method have proved it to be reliable with respect to reproducibility, accuracy, and precision.
63Ni Complexes in Rabbit Serum and Urine after Injection of 63NiCl2
Authors: Van Soestbergen Maria , Sunderman F William 
Published: January 2020

Abstract
Radioactive nickel chloride (63NiCl2) was injected i.v. into rabbits in dosage of 0.24 mg Ni/kg body wt. 63Ni was rapidly cleared from the serum (T1/2 ≃ 8.2 h) during the period from 1 h to 2 days after the injection, but slowly (T1/2 ≃ 95 h) during the period from 4 to 7 days after the injection. During 24 h after injection of 63NiCl2, an average of 90% of serum 63Ni was bound to albumin and 10% was ultrafiltrable. Chromatography on Sephadex G-25 demonstrated the presence of five distinct 63Ni complexes (Fractions I to V) in serum ultrafiltrates. During 24 h after injection of 63NiCl2, an average of 78% of the administered dose of 63Ni was excreted in the urine. Chromatography of the urine on Sephadex G-25 separated three 63Ni complexes, which appeared to have identical chromatographic mobilities as serum Fractions II, III, and V. The chemical identities of the ultrafiltrable 63Ni complexes in serum and urine have not been established, although one (Fraction V) resembles Ni histidine in its chromatographic mobility on Sephadex G-25. This study demonstrates that ultrafiltrable nickel in serum and urine does not exist primarily as free Ni(II), but instead as Ni complexes, and suggests that ultrafiltrable Ni receptors play an important physiological role in nickel homeostasis by serving as diffusible vehicles for the extracellular transport and renal excretion of nickel.
Estimation of Serum Proteins by Electrophoresis on Cellulose Acetate
Authors: Keyser J W , Watkins G L 
Published: January 2020

Abstract
We have evaluated results for albumin obtained by a standard procedure for cellulose acetate electrophoresis of proteins in serum. The Ponceau S-stained albumin and globulins were eluted and the albumin was calculated by the generally accepted formula [(albumin-bound dye absorbance/absorbance of total protein-bound dye) x total serum protein concn] and by the formula (absorbance of albumin-bound dye in test/absorbance of albumin-bound dye in a reference serum) x concn of albumin in reference serum. The ratio of values by the first and second methods ranged from 0.93 to 1.30, the first giving the higher results in cases of discrepancy. These findings confirm the limitations in accurately calculating any serum-protein fraction by the first method. The second method appears to be the more accurate.
A Study of Various Electrophoretic and Inhibition Techniques for Separating Serum Alkaline Phosphatase Isoenzymes
Authors: Johnson Roy B , Ellingboe Karen , Gibbs Phyllis 
Published: January 2020

Abstract
Optimal conditions for the identification and semiquantitation of the isoenzymes of serum alkaline phosphatase are reviewed and a new technique is presented. In the recommended scheme, specific disc electrophoretic conditions are used to produce good separations, which are improved by comparing the alkaline phosphatase patterns of sera before and after treatment with heat or urea (3 mol/liter). This method is compared with other electrophoretic and inhibition techniques. Interpretation is aided by (a) reference to the relative mobilities of each isozyme, and (b) inactivation of bone alkaline phosphatase by heat or urea. The isozymes originating from bile, intestine, placenta, bone, and liver can be independently resolved as separate bands with untreated sera except when bone alkaline phosphatase is grossly increased. The proposed method permits identification and semiquantitation of all the recognized alkaline phosphatase isozymes in most sera, as an aid to diagnosis.
Prenatal Diagnosis of Genetic Disorders: Trials and Tribulations
Authors: Davidson Ronald G , Rattazzi Mario C 
Published: January 2020

Abstract
Prenatal detection of genetic disorders by amniocentesis in the second trimester of pregnancy, followed by studies of amniotic fluid cells, has added a new dimension to genetic counseling. This paper reviews the technique, indications, results, and complications, with emphasis on the problem of interpretation of results, particularly in the detection of fetuses with metabolic diseases.
Chemical Basis of the Sulfo-phospho-vanillin Reaction for Estimating Total Serum Lipids
Authors: Knight Joseph A , Anderson Shauna , Rawle James M 
Published: January 2020

Abstract
Results with the "sulfo-phospho-vanillin" reaction, much used for determining total serum lipids, have been favorably compared with those for the gravimetric method. We investigated the basic chemistry of the reaction and determined the reactivity of this single reagent with various lipids. Our results suggest that: (a) The reaction requires a carbon-carbon double bond. (b) Concentrated sulfuric acid reacts with unsaturated lipids in the initial step to form a carbonium ion. (c) Phosphoric acid reacts with vanillin to produce a phosphate ester, with a resulting increase in the reactivity of the carbonyl group. (d) The carbonium ion reacts with the carbonyl group of phosphovanillin to form a colored compound, which is stabilized by resonance. (e) Unsaturated compounds with more than one double bond react, but reaction may vary with steric hindrance. (f) The method is reasonably precise, but its accuracy depends primarily on the reference standard used.
Sensitive, Rapid Quantitation of Serum and Urinary Protein by Electroimmunodiffusion
Authors: de Pizzolato M C B , Del Campo G B , Pizzolato M A , Vergani C 
Published: January 2020

Abstract
A simple, rapid method is described for quantitative estimation of albumin, transferrin, and α2-macroglobulin on strips of antibody-spread gelatinized cellulose acetate. Samples are applied on a strip with 1-µl micropipets and a volumetric distributor is used to coat the strip with 2µl of a diluted antiserum per square centimeter. Electrophoresis requires 2 h for albumin and at least 3 h for α2-macroglobulin and transferrin. Precipitate peaks are sharply defined. As little as 10 ng of protein can be estimated, so urinary proteins can be studied without concentrating the sample.
A Study of the Problems of Inactivation of Creatine Kinase in Serum
Authors: Dalal Fram R , Cilley Jonathan , Winsten Seymour 
Published: January 2020

Abstract
Addition of sulfhydryl groups to the reaction mixture, to stabilize serum creatine kinase (creatine phosphokinase, CPK), results in apparent increases in the activity of this enzyme in many sera. In addition, in sera from patients just after myocardial infarction, assays for sulfhydryl-activated CPK have a different clinical pattern than do those for CPK assayed without sulfhydryl activators: activities are greater and remain abnormally high longer in assays in which the enzyme is sulfhydryl activated. If the assay is done without sulfhydryl activators present, technical difficulties appear, because CPK in serum is rapidly inactivated at room temperature. CPK is apparently inactivated in at least two ways. One, which is irreversible, is inhibited by albumin; the other, which is reversible by sulfhydryl groups, seems to result from the presence of substances in the pooled serum used that are both protein bound and free.
Comparison of Results from the Du Pont "ACA" and Technicon "SMA 12/ 60"
Authors: Westgard James O , Lahmeyer Brenda L 
Published: January 2020

Abstract
The Du Pont "Automatic Clinical Analyzer" (ACA) and the Technicon "SMA 12/60" were compared as to precision, range of linearity, and results for sera from patients. Precision of the ACA was equal to or better than that of the SMA 12/60 for all determinations except SGOT in the normal range. The ACA showed a wider range of linearity for BUN, total protein, LDH, alkaline phosphatase, SGOT, and bilirubin, and equal linear ranges for glucose and albumin. Patient’s sera comparisons showed differences for glucose in uremic sera. Albumin values from the ACA did not compare well with those by HABA dye method from the SMA 12/60, but did compare well with values obtained by electrophoresis and by a bromcresol green method adapted to the SMA 12/60. Bilirubin values from the ACA were higher than those from the SMA 12/60. Comparable results were obtained for the enzyme determinations when the SMA 12/60 was calibrated in the same units as the ACA.
Direct Fluorometric Determination of Urea in Urine
Authors: Rho Joon H 
Published: January 2020

Abstract
In this quantitative fluorometric method, diacetylmonoxime is used for the determination of the urea. The products of the reaction of urea with diacetylmonoxime in acid solution exhibit two fluorescence maxima, at 410 and 525 nm. The intensity of the 525 nm maximum is linear over a wide range of urea concentration and the reaction is shown to be practically specific for urinary urea.
Characterization of Electrophoretic Lipoprotein Fractions: Immunochemical and Electron Microscopic Studies
Authors: Werner Mario , Jones Albert L 
Published: January 2020

Abstract
To improve the characterization of electrophoretic lipoprotein subfractions, we developed two new techniques for analyzing lipoproteins after electrophoresis on thin agarose layers. Overlay with antisera exactly localizes specific apoproteins without any distortion caused by antigen diffusion; electron microscopy of eluted fractions determines the varying particle-size distribution. Applied together, these methods can detect individual differences between hyperlipemic samples that are not immediately apparent in the electrophoretic pattern, and should provide valuable new insight into the classification of hyperlipoproteinemias.
Accelerated Single-Column Procedure for Automated Measurement of Amino Acids in Physiological Fluids
Authors: Efron Klara , Wolf Paul L 
Published: January 2020

Abstract
This automated analytical procedure involves a single 27 cm x 0.9 cm column of UR-40 resin and a stepwise elution with sodium citrate buffers. In one sequential run more than 35 acidic, neutral, and basic amino acids can be measured in physiological fluids in 6 h. Thus, a minimum of three runs can be performed per 24 h, during which the analysis can be unattended. Increased sensitivity allows the use of small samples (such as 0.2 ml of plasma ultrafiltrate). Picric, sulfosalicylic, or perchloric acids are not required for sample preparation. Ultrafiltration under nitrogen pressure is used instead and gives a clear solution containing the free amino acids. Ultrafiltration rate is 1 ml per 1.5 h; 10 samples can be processed simultaneously.
Determination of Serum Albumin with the "SMA 12/60" by a Bromcresol Green Dye-Binding Method
Authors: Westgard James O , Poquette Michael A 
Published: January 2020

Abstract
A bromcresol green (BCG) method for serum albumin has been adapted to the Technicon "SMA 12/60." Sensitivity and linearity critically depend on the concentrations of BCG and surfactant ("Brij-35"). With appropriate concentrations, linearity to 6.0 g/dl is achieved. Interaction is 2-3%. Standard deviations for quality control pools of 2.0 and 4.7 g/dl during three months of routine service were 0.06 and 0.11 g/dl. Values agree well with values determined by the Du Pont "ACA" (bias = 0.047 g/dl, SD = 0.191 g/dl, t = 1.746, r = 0.975, n = 53), by a modified Beckman "DSA" method in which BCG is also used (bias = 0.006, SD = 0.164, t = 0.398, r = 0.976, n = 115), and by electrophoresis on cellulose acetate (bias = 0.028, SD = 0.203, t = 1.006, r = 0.961, n = 54). Blank errors for hemolyzed samples (plasma hemoglobin up to 350 mg/dl), icteric samples (bilirubin up to 30 mg/dl), and lipemic samples (triglycerides up to 500 mg/dl) are 0.2 g/dl or less when the blank channel is not used. Normal range is estimated to be 3.5 to 4.8 g/dl (n = 145; 2.5 and 97.5 percentiles).
Separation of Isoenzymes of Alkaline Phosphatase by Substrate—Gel Imprint after Electrophoresis on Cellulose Acetate
Authors: Rhone Douglas P , Mizuno Florence M 
Published: January 2020

Abstract
Isoenzymes of alkaline phosphatase, separated by electrophoresis on cellulose acetate, were developed by a substrate—gel imprint. The gel was prepared in an alkaline buffer and contained β-naphthyl acid phosphate, which was hydrolyzed to β-naphthyl and phosphorus. The β-naphthyl was coupled to the diazonium salt, Fast Violet B, and an insoluble red compound was formed on a cellulose acetate strip to mark the sites of enzyme activity. The electrophoretic mobilities of the isoenzymes were compared with those of serum proteins. Supporting data included thermostability and chemical inhibition (urea and phenylalanine) studies. This method was used to evaluate patterns in tissues and human sera.
Fluorometric Assay of Diphenylhydantoin in Plasma or Whole Blood
Authors: Dill Wesley A , Glazko Anthony J 
Published: January 2020

Abstract
A highly sensitive assay procedure for 5,5-diphenylhydantoin (DPH) involves oxidation with alkaline permanganate to form benzophenone. This is then extracted with heptane, allowed to react with concentrated sulfuric acid, and the fluorescence of the reaction product is measured. The procedure appears to be fairly specific for DPH; 5-(p-hydroxyphenyl)-5-phenylhydantoin (a DPH metabolite), phenobarbital, or other anticonvulsant drugs do not interfere. The sensitivity of the fluorometric procedure permits assays on finger-blood specimens. It provides a simple means for evaluating the effectiveness of a given dose schedule in different subjects.
Countercurrent Chromatographic Separation of Catecholamine Metabolites from Urine
Authors: Hurst Robert E , Ito Yoichiro 
Published: January 2020

Abstract
A continuous-flow method is described for achieving high-resolution separations with liquid-liquid partition without the use of an inert support. The instrument consists of a 60-m coil of Teflon tubing (0.85 mm i.d.) mounted planetarily on a centrifuge arm. The coil is filled with the stationary phase and the mobile phase is pumped through the column in a direction opposing the flow of the stationary phase imposed by centrifugal force. With ethyl acetate as the stationary phase and an aqueous solution of NaCl (5 g/100 ml) and acetic acid (10 ml/100 ml) as the mobile phase, (3-methoxy-4-hydroxyphenyl)-hydroxyacetic acid (VMA) and (3-methoxy-4-hydroxyphenyl)-acetic acid (HVA), the major products of catecholamine metabolism, elute in 2 and 7 h, respectively. With a 280 nm-monitor on the effluent, abnormal amounts of these two compounds can be detected in 1 ml of urine. The fractions containing these compounds were analyzed by both gas—liquid and thin-layer chromatographic methods. HVA is essentially completely separated from other compounds. Although VMA is found with 3-8 other unknown compounds, none interferes with any of the colorimetric assays for VMA. Several abnormal urines from patients with various types of neurosecretory tumors were examined, and a distinctive pattern of urinary excretion of these compounds was seen for each type of case.
Simplified Rapid Electroimmunodiffusion Technique for Measuring α1-Antitrypsin in Serum
Authors: Manildi Ernest R 
Published: January 2020

Abstract
A rapid method is described for immunochemical quantitation of α1-antitrypsin by electroimmunodiffusion on cellulose acetate. Compared to earlier qualitative screening techniques for trypsin activity, including trypsin inhibitory capacity, the procedure presented here is specific, reproducible, and quantitative for α1-antitrypsin. It is inexpensive and less time consuming than electroimmunodiffusion or radial immunodiffusion in agar gel. The test is so simply done that this procedure can be routinely used by most hospital clinical laboratories. The technique is easily adapted to immunochemical quantitation of other protein fractions.