bluuebunny/crossref_metadata_2025_split huggingface dataset:
New Perspectives in Coagulation Testing
Authors: Fareed Jawed , Messmore Harry L , Bermes Edward W 
Published: January 2020

Abstract
Vol. 26
p 1386, Table 5, column 3, entry two should read "71 ± 26," not "17 ± 26."
p 1933, under the heading Notes, change first sentence to read "...equal to the numerical value of the molar..."
Vol. 27
p 202, The last equation for sT2 should read: 5W2 + SD2 [n(k - 1)]/(kn - 1)
p 204, col. 2, fourth full paragraph "25 mg/L" should read "25 g/L"
Because of a postal delay, one paper was printed without the authors' corrections, which are:
p 287, para. 1, fifth line "Theoretical...," insert the word "and" after "alternates."
Table 1, column 4: last entry should read "+7.57(0.974)"; column 5: first entry should read "±6.5." Amend title of Table 2 to read "Quantitative Performance of Second- and Fourth-Derivative Assays for Paraquat Dichloride Extracted from Horse Serum," and change "hight" to "higher" in footnote a.
p 288, under "Procedure," in two places the words "setting the instrument on" should be changed to "using as reference."
p 289, under "Aqueous...," in first paragraph, fourth line, delete ",dissolved" and insert "solution." In the next paragraph delete the words "is used...satellite" and insert instead "measure (to the long-wavelength satellite) is used." In the fourth line of the first paragraph in column 2, change "is" to "in."
p 290, line 10 under "Discussion": correct spelling is "Åkerblom."
p 297, In the equation, E is activity of the enzyme in serum at time t, less the basal activity.
p 317, In first sentence of "Discussion," the binding constants should be 1010 to 1011 L/mol.
p 343: The following Table was inadvertently omitted from the Letter
See table in PDF file
p 422, Under "Reagents," dilute the 4 mL of D-glucarate solution with 16 (not 46) mL of 10 mmol/L HCl.
p 425, Table 4, last column should read: 5.07 (1.72) and 5.06 (1.55).
p 508, See Letter.
Characterization and intermethod relationships of materials containing purified human pancreatic and salivary amylase.
Authors: Sampson E J , Duncan P H , Fast D M , Whitner V S , McKneally S S , Baird M A , MacNeil M L , Bayse D D 
Published: January 2020

Abstract
We describe the preparation and characterization of materials containing human pancreatic and salivary alpha-amylase (EC 3.2.1.1) and examine their relationship to endogenous amylase in human serum. Amylase was purified from human pancreas and saliva by solvent- and salt-fractionation and column chromatography to specific activities of 63 and 279 kU/g, respectively. Four liquid pools, differing only in activity, were prepared from each source of amylase, each in a matrix containing, per liter: 30 g of human albumin, 50 mmol of sodium chloride, 1 mmol of calcium chloride, and 50 mmol of Tris hydrochloride buffer, pH 7.4. Characterization of the pools showed that the amylase activity in the materials was stable for at least six months at 25 degrees C; among-vial variability of amylase activity was less than or equal to 0.5% (2 CV); and the pools were free from eight possible contaminating enzymes. Plots of salivary vs pancreatic amylase activity measure in our materials with eight commercially available methods showed least-squares slopes ranging from 0.51 to 1.0. The intermethod "commutability" of the materials (i.e., how closely they mimic endogenous serum amylase) was examined in relationship to approximately 100 human sera.
Laser nephelometry of orosomucoid in serum of newborns: reference intervals and relation to bacterial infections.
Authors: Bienvenu J , Sann L , Bienvenu F , Lahet C , Divry P , Cotte J , Bethenod M 
Published: January 2020

Abstract
Orosomucoid was evaluated by laser-nephelometry in 1790 sera collected from 1170 newborns. Within-run precision (CV) was 2.1 to 4.2%, between-run 2.9 to 5.2%. Results correlated well with radial immunodiffusion (r = 0.989). Results can be obtained within 1 h. Orosomucoid concentrations in serum at birth range from 130 to 200 mg/L and are influenced by gestational age during the first two days of postnatal life. Thereafter, the values increase very rapidly in the first week of life, concentrations being the same as in adults by about 10 months. In 66 of 78 cases of severe bacterial infections, orosomucoid concentrations were above normal. Evidently, serum orosomucoid constitutes an useful index in diagnosis and monitoring of bacterial infections in the neonatal period.
Interference of levodopa and its metabolites with colorimetry of uric acid.
Authors: Bierer D W , Quebbemann A J 
Published: January 2020

Abstract
Reportedly, levodopa (L-DOPA) administration produces spuriously high values for plasma uric acid as measured by the commonly used phosphotungstic acid-hydroxylamine colorimetric method. We confirm this interference, not only by L-DOPA but also by three of its major metabolites: dopamine, 3,4-dihydroxyphenylacetic acid, and 3-methoxy-4-hydroxyphenylacetic acid. However, at therapeutic concentrations in plasma (less than 5 mg/L), the maximum spurious uric acid concentration due to L-DOPA is less than 2 mg/L. Also, at reported peak plasma concentrations of L-DOPA plus three of its major metabolites, the maximum spurious uric acid concentration due to all four compounds combined is less than 8.5 mg/L. Therefore, the hyperuricemia observed with this method in some patients who are chronically receiving L-DOPA cannot be attributed only to interference by L-DOPA and its metabolites in the colorimetric determination of uric acid. Evidently L-DOPA may increase laboratory values for plasma uric acid concentrations, both by pharmacological and chemical mechanisms.
Clinical evaluation of a radiometric assay specific for creatine kinase isoenzyme MB.
Authors: Kwong T C , Rothbard R L , Biddle T L 
Published: January 2020

Abstract
A new radiometric assay specific for creatine kinase isoenzyme MB was evaluated with respect to its precision and agreement with a conventional electrophoretic CK-MB assay for the diagnosis of myocardial infarction. The reference interval we find for serum CK-MB in healthy subjects is 0--30 micrograms/L. The coefficients of variation at 197 and 40 micrograms of CK-MB per liter, were 5.2 and 11.5%, respectively. In a clinical study of 52 consecutive patients admitted into a Coronary Care Unit with a diagnosis of suspected myocardial infarction, there was overall agreement in CK-MB results by the two assays for 51 of 52 patients. A more sensitive and quantitative assay that is specific for CK-MB can be helpful in cases where diagnosis of myocardial infarction is equivocal.
Quantitative determination of human plasma apolipoprotein A-I by laser immunonephelometry.
Authors: Rosseneu M , Vercaemst R , Vinaimont N , Van Tornout P , Henderson L O , Herbert P N 
Published: January 2020

Abstract
A technical procedure is described for quantitation of human apolipoprotein A-I (apo A-I) in normal plasma or serum by immunonephelometry. Dilution of the plasma samples with 6 mol/L guanidine chloride ensures maximum exposure of the antigenic sites of the apoprotein and enables optimum quantitation of the apo A-I without requiring extraction with organic solvents. Similar data are obtained by this assay and with radioimmunoassay for normal subjects (1.2--1.5 g/L), and the results obtained on 31 patients are correlated with a coefficient of 0.92. The apo A-I values are correlated with values for plasma high-density lipoprotein cholesterol (r = 0.64). The interassay CV for immunonephelometry is about 7% and the standard curve is linear between 0.1 and 1.0 microgram of apo A-I per sample, corresponding to a 150-fold dilution of serum or plasma. The assay is applicable to plasma samples containing as much as 4 g of triglycerides per liter. At higher concentrations plasma delipidation is required.
High-molecular-mass alkaline phosphatase in serum and bile: physical properties and relationship with other high-molecular-mass enzymes.
Authors: Crofton P M , Smith A F 
Published: January 2020

Abstract
High-molecular-mass alkaline phosphatase has similar properties in serum and bile. It is of sufficiently large size to be excluded by Sepharose 6B and carries a high negative charge at alkaline pH, largely accounted for by the presence of sialic acid residues. It is slightly more heat labile than the lower-molecular-mass liver isoenzyme. Other enzymes originating from the hepatocyte plasma membrane are present as similar high-molecular-mass forms in normal bile, and in both bile and serum from patients with liver disease. The activities of these relatively large enzymic forms in serum were correlated with one another and we show they are converted similarly to lower-molecular-mass forms by solubilization with detergents. However, they carry slightly different net charges, thereby ruling out the possibility that they all consisted of a single homogeneous multi-enzyme complex. These findings are discussed in the light of two current hypotheses that the high-molecular-mass enzymes represent (a) membrane fragments released into the circulation in liver disease or (b) low-molecular-mass enzymes that aggregate, after release, with the lipid and protein in the circulation.
Column affinity chromatography for bound/free separation in ligand assays. I. Radioimmunoassay of choriomammotropin (human placental lactogen).
Authors: Cornale P , Bonazzi M , Multinu C , Romelli P , Vancheri L , Pennisi F 
Published: January 2020

Abstract
A method is described for separating antibody-bound from free fractions in ligand assays by column affinity chromatography, and its application to radioimmunoassay of choriomammotropin. In the method, 70 x 10 mm (i.d.) polypropylene columns containing about 150 mg of immunosorbent (goat anti-rabbit gamma-globulins covalently linked to Sepharose CL-4B) are used. Standards or unknowns, tracer and antiserum, pipetted into bottom-capped columns, are kept separated from the immunosorbent bed by a porous polyethylene disc and allowed to react for 15 min at room temperature. The reaction mixture is then allowed to pass through the columns by removing the bottom caps. Free antigen is eluted by washing the column, and discarded; antibody-bound fractions remain bound to the immunosorbent. The radioactivity in the columns is counted. The major advantages of the present technique, arising from the liquid-phase reaction combined with the solid-phase separation by column affinity chromatography, are the very low nonspecific binding (less than 1%), good sensitivity (0.02 mg/L), good precision (CV 3.4%), and simple and fast (30-min) assay. For 50 clinical samples so assayed (gamma) and compared with a polyethylene glycol precipitation technique (x), the regression equation was: y - 0.14 + 0.98x (r = 0.994). The assay method was clinical validated by 3493 determinations.
Specific spectrophotometric assay for the M isoenzymes of pyruvate kinase in plasma samples containing mixtures of the muscle (M) and liver (L) isoenzymes.
Authors: Edwards R J , Watts D C 
Published: January 2020

Abstract
Plasma pyruvate kinase (EC 2.7.1.40) activity contains two major isoenzymes. The "L" type originates from liver (erythrocytes contain a similar isoenzyme), the "M" type predominantly from skeletal muscle. The diagnostic use of pyruvate kinase as an index of muscle leakage requires an assay of only the M type. An M-type-selective assay for mixtures of the two isoenzymes was devised, based on the differences that the L form has a higher Km for phosphoenolpyruvate and is inhibited by about 95% by a high concentration of ADP. All relevant conditions of the assay have been examined and the reaction system has been optimized at 30 degrees C. The assay yields the expected Km values for M type pyruvate kinase. An apparent increase in activity in hemolysed plasma samples was found to be derived from leukocytes.
A screening method for establishing laxative abuse.
Authors: de Wolff F A , de Haas E J , Verweij M 
Published: January 2020

Abstract
Abuse of laxatives, most of them belonging to the group of colonic stimulants or cathartics, can cause various disorders. Extensive diagnostic work can be avoided by early toxicological screening of the suspected patients with respect to laxatives. Because no screening method of this kind was available, we developed a procedure with which all phenolic and anthraquinone laxatives--except sodium picosulfate--can be detected in urine. This method is based on high-performance thin-layer chromatography in two systems after pretreatment of a 20-mL urine sample with beta-glucuronidase and subsequent column extraction. The procedure is very sensitive: at least 32 h after a single dose of bisacodyl, danthron, phenolphthalein, or sennoside, the drug can be detected in the urine. Bisoxatin and oxyphenisatin are still detectable in the urine 18 h after intake. The method is also highly specific; none of 73 other drugs interfered in either of the two chromatographic systems. This procedure can be helpful for the early diagnosis of laxative abuse.
Effect of centrifugation on fluorescence polarization of amniotic fluid.
Authors: Simon N V , Elser R C , Levisky J S , Polk D T 
Published: January 2020

Abstract
Fluorescence polarization was measured on amniotic fluids of different gestational ages before and after centrifugation at relative centrifugal forces of 34 to 4955 x g. Centrifugation significantly increased the fluorescence polarization values over those of uncentrifuged amniotic fluids. The greatest increase was observed in the most "mature" fluids centrifuged at 34 to 230 x g. Almost without exception, use of centrifugal forces greater than 1239 x g did not further increase fluorescence polarization values.
Response-surface-optimized, zinc-enhanced assay for serum alkaline phosphatase.
Authors: Thompson J C , Hodges C T , Dobler G L , Williamson J A 
Published: January 2020

Abstract
An optimized assay for alkaline phosphatase (EC 3.1.3.1) is reported. A discrete analyzer, the DuPont Automatic Clinical Analyzer (aca), was used for this study. The assay is based on results of response-surface experimental co-optimization techniques, and response is enhanced over the present aca assay. A key feature is the incorporation of zinc ions, both to fully optimize the assay and to reduce the sensitivity of measured activity to zinc-binding impurities in the buffer, 2-amino-2-methyl-1-propanol. In addition, a simple technique is described for measuring relative concentrations of zinc-binding impurities in this buffer. These features should be considered in the design of any assay for alkaline phosphatase that is based on p-nitrophenyl phosphate as substrate and 2-amino-2-methyl-1-propanol as buffer.
Spectrophotometric assay for urinary N-acetyl-beta-D-glucosaminidase activity.
Authors: Horak E , Hopfer S M , Sunderman F W 
Published: January 2020

Abstract
An improved assay for N-acetyl-beta-D-glucosaminidase activity in urine is described that involves (a) gel filtration to separate the enzyme from inhibitors in urine, (b) enzymic hydrolysis of p-nitrophenyl-N-acetyl-beta-D-glucosaminide at pH 4.4, and (c) spectrophotometry of the liberated p-nitrophenylate. Measurements of activity of the enzyme in 58 urine specimens correlated closely (r = 0.9998) with results by an established procedure. The within-run coefficient of variation (CV) was 3.7%; the between-run CV averaged 6.8%. Reference values for the activity were established by assays of urine specimens from 135 healthy persons, age two weeks to 52 years. Efficacy of the assay for detection of nephrotoxicity was demonstrated in rats after experimental induction of reversible renal insufficiency by intraperitoneal injection of nickel chloride. Clinical application of the assay in approximately 1000 patients corroborated its utility for detection and monitoring of renal disorders.
Reversed-phase C18 cartridge for extraction of estrogens from urine and plasma.
Authors: Heikkinen R , Fotsis T , Adlercreutz H 
Published: January 2020

Abstract
We describe a simple method for extraction of estrogens that is efficient over the whole polarity range of estrogen metabolites in urine and plasma. A small reversed-phase C18 cartridge (Sep-Pak C18, Waters Associates, Inc.) is used for this purpose. After application of the biological fluid, followed by an aqueous wash, estrogens are eluted in 3 mL of methanol. For urine the pH should be kept at 3 before the methanol elution. When estrogens are extracted from plasma, the steroid-protein interaction is counteracted by the presence of triethylammonium sulfate and D-norgestrel at pH 5. The recoveries of added 3H-labeled estrogens are essentially quantitative. The capacity of the column is high and estrogens can be extracted from large volumes of pregnancy urine without loss in the washing water. Because of the high flow rate (2 mL/min) and the small volume of methanol in which the estrogens are eluted, the whole procedure is convenient and rapid.
Precision of "high-performance" liquid-chromatographic assays with sample pretreatment. Error analysis for the Technicon "FAST-LC" system.
Authors: van der Wal S , Snyder L R 
Published: January 2020

Abstract
A comprehensive theory has been presented elsewhere (Anal. Chem. 53: 877-884, 1981) for the various contributions to assay imprecision in procedures that are based on sample extraction followed by "high-performance" liquid chromatography. Experimental data (1800 assays, 8400 results) for the Technicon FAST-LC system are used with this theory in an effort to understand and control the precision of clinical-laboratory procedures, both automated and manual. This study provides specific conclusions and recommendations on matters such as: standardization procedures and protocols, physical properties requires in internal standards, the relative importance of different sources of imprecision and means for improving precision, the relative importance of temperature control in pretreatment and liquid-chromatographic analysis, and the precision obtainable with small sample volumes or with samples containing very low concentrations of analyte (e.g., in assays for free drugs). Automation evidently can lead to twofold greater assay precision, other factors being equal, for liquid-chromatographic procedures that include sample pretreatment. Similarly, internal standardization, properly applied, can decrease assay imprecision by twofold.
Plasma glucose concentrations of whole blood, as determined with a multilayer-film analytical element.
Authors: Ohkubo A , Kamei S , Yamanaka M , Arai F , Kitajima M , Kondo A 
Published: January 2020

Abstract
A new type of multilayer film analytical element--consisting of a spreading layer, a blocking layer, an enzymic reagent layer, and a transparent layer--has been developed for blood glucose determination. After a spot of whole blood is dropped on the film, the plasma glucose concentration is determined in 6 min without further manipulations. Precise measurement of sample volume spotted on the film is not necessary for good results, nor is knowledge of the hematocrit in the range 10-46%. The minimum concentration of glucose detectable by this method is 100 mg/L. The coefficients of variation, within-run and between-run, were all less than 2.5% for 800-4000 mg/L glucose concentrations. Macromolecules and hydrophobic substances in blood did not interfere. This method seems suitable for emergency use, especially.
Immunological studies of ribonuclease C from human urine.
Authors: Cranston J W , Hoover H C , Crisp E R 
Published: January 2020

Abstract
Antiserum to human urinary RNase C [ribonuclease (pancreatic), EC 3.1.27.5], developed in rabbits, was used to characterize this enzyme through studies of inhibition of RNase C-catalyzed poly(C) hydrolysis and of competition in a RIA. By either assay, the antiserum failed to cross react with human urinary RNase U (EC 3.1.27.-) or bovine pancreatic RNase A (EC 3.1.27.5). RNase C is immunologically identical to the poly(C)-active RNase in various human sera, including samples obtained from normal individuals, patients with pancreatic carcinoma, pancreatitis, or other malignant and nonmalignant diseases. This conclusion is based on the finding of superimposable antibody dose-inhibition curves for poly(C) hydrolysis and parallel competition RIA curves for RNase C and the various sera. There was a positive correlation (r = 0.73; p less than 0.001) between concentrations of RNase C as determined by poly(C) hydrolysis and competition RIA in serum samples from 102 patients. Therefore, the latter technique provides al alternative method for measuring RNase C in sera.
Measurement of alkaline phosphatase activity: characterization and identification of an inactivator in 2-amino-2-methyl-1-propanol.
Authors: Rej R , Bretaudiere J P , Jenny R W , Jackson K Y 
Published: January 2020

Abstract
An inactivator of alkaline phosphatase (EC 3.1.3.1) in 2-amino-2-methyl-1-propanol is demonstrated and characterized. This time-dependent inactivation results from chelation of enzyme-bound Zn2+; it is reversed by addition of Zn2+ and, to a lesser extent, other divalent metal ions. Cu2+ is an effective spectral indicator and can be used to determine the presence and quantity of inactivator. Data obtained from enzyme inactivation, Cu2+ absorbance spectra, "high-performance" liquid chromatography, thin-layer chromatography, Fourier-transform infrared spectroscopy, and mass spectroscopy indicate that the inactivator is 5-amino-3-aza-2,2,5-trimethylhexanol. This compound, even in trace amounts (less than 0.05% on a molar basis), shown to inactivate alkaline phosphatase.
Hyperlabile diabetes accompanied by insulin resistance.
Authors: Renie A , Hamilton R G , Adkinson N F , Rendell M S 
Published: January 2020

Abstract
It is generally held that high insulin antibody concentrations, by "buffering" abrupt swings in free insulin concentrations after injections of exogenous insulin, tend to stabilize blood glucose variations in diabetic patients. However, we encountered a patient with extremely labile diabetes coexisting with insulin resistance. This patient's injections were switched to pure porcine insulin from his usual mixed bovine/porcine insulin, in an effort to decrease his insulin requirement. This treatment was successful, and, as his insulin dosage decreased, his diabetic lability diminished substantially. His diabetes was eventually considered stabilized on about 22 units of porcine insulin daily. The serial decrease in his insulin antibody concentrations, monitored by use of solid-phase radioimmunoassay, paralleled the disappearance of his diabetic lability as well as the decrease in his insulin requirement.
Glucose oxidase immunoenzyme methodology as a substitute for fluorescence microscopy in the clinical laboratory.
Authors: Rathlev T , Hocko J M , Franks G F , Suffin S C , O'Donnell C M , Porter D D 
Published: January 2020

Abstract
Enzymes as markers for antigens or antibodies in immunohistochemical procedures have several advantages over commonly used fluorochrome labels. These include use of a regular light microscope and the ability to get permanently stable slide preparations. Glucose oxidase (EC 1.1.2.3.4), being absent in mammalian tissue, provides no background staining, such as that seen with the commonly used horseradish peroxidase (EC 1.11.1.7) owing to peroxidase-like activity in tissues. A glucose oxidase histochemical method is detailed that is useful for detection of human antibodies; it can be easily used in clinical laboratories as a substitute for fluorescent techniques.