bluuebunny/crossref_metadata_2025_split huggingface dataset:
Direct-Contact (Membraneless) Hemoperfusion through Oils
Authors: Evenson M A , de Vos D 
Published: January 2020

Abstract
Oil-hemoperfusion is a highly promising procedure, as indicated by in vitro feasibility studies with human blood and in vivo experiments with rhesus monkeys. Direct liquid—liquid extraction is used to remove toxic or unwanted substances from whole blood. By choosing the proper oil or modification of an oleaginous liquid, cholesterol, total bilirubin, and lipid-soluble drugs such as glutethimide can be selectively removed or adjusted to the desired concentration with a single liquid—liquid extraction. Damage or loss of cellular components such as erythrocytes, leukocytes, and platelets is immeasurably small or nonexistent. Undesirable extraction of other vital biological substances and (or) back extraction of substances from the oil into the blood is so small that side effects or aftereffects of in vivo oil-hemoperfusion studies were considerably less than anticipated.
Automated Determination of Serum Oxytocinase Activity
Authors: Peeters J A B M 
Published: January 2020

Abstract
An automated kinetic method is described for determination of oxytocinase activities in the sera of pregnant women. The reaction mixture consists of serum in phosphate buffer and the substrate L-cystine-bis-p-nitroanilide. The absorbance increase, due to the appearance of the reaction product, p-nitroaniline, is recorded during 2 min. With this method, 25 determinations per hour can easily be done.
A Linear Absorbance Converter for Continuous-Flow Colorimeters
Authors: Walker Leonard , Amador Elias 
Published: January 2020

Abstract
The photocell transmittance output from continuous-flow colorimeters can be converted into linear absorbance by means of a simple solid-state circuit. The circuit includes a field effect transistor operational amplifier and a logarithmic operator, plus several stabilizing circuit networks. The working range is 1.2 absorbance units, which for most applications is an improvement of 50% over the unmodified colorimeter, at wavelengths of 420 to 700 nm. The output can drive the conventional AutoAnalyzer recorder, or a 2-input, low-cost recorder such as the Heath Kit IR-18M.
A Computer Program for Calculating Blood Acid-Base Parameters on an Olivetti "Programma 101" Desk Computer
Authors: Hardt Jørgen 
Published: January 2020

Abstract
A computer program is presented for a desk calculator, to be used in calculating Pco2, standard bicarbonate, and base excess. The computer simulates the readings from the Siggaard-Andersen nomogram [Scand. J. Clin. Lab. Invest. 14, 598 (1962)].
Identification and Biochemical Significance of Substituted Furans in Human Urine
Authors: Mrochek J E , Rainey W T 
Published: January 2020

Abstract
The normal urinary chromatographic pattern on the high-resolution UV-Analyzer exhibits approximately 20 major peaks and more than 100 minor peaks. Three of the major chromatographic peaks, observed in most urinary samples from both normal and pathologic subjects, have recently been identified as 5-hydroxymethyl-2-furoic acid, 2-furoylglycine, and 2,5-furandicarboxylic acid. A related compound, 5-hydroxymethyl-2-furoylglycine, was also identified in the urine of a leukemic patient who was excreting an abnormal amount of the free acid. The compound 5-hydroxymethyl-2-furoic acid and its glycine conjugate have not, to our knowledge, been previously reported in human urine, and the excretion of 2-furoylglycine and 2,5-furandicarboxylic acid by all humans is not generally recognized. The four identified compounds seem to be biochemically interrelated, and a mechanism for their formation from uronic acids is postulated. Analytical techniques and results utilized in the identification of these compounds are discussed. High-resolution (m/Δm ≈ 20,000) mass spectrometric data obtained from three independent laboratories are presented for 5-hydroxymethyl-2-furoic acid, illustrating the accuracy and precision that can be expected for a random sample submitted to a well-equipped facility.
Kinetic Method for Determining Acid Phosphatase Activity in Serum with Use of the "CentrifiChem"
Authors: Fabiny-Byrd Diane L , Ertingshausen Gerhard 
Published: January 2020

Abstract
Acid phosphatase activity is determined by splitting 1-naphthyl phosphate, concurrently diazotizing the released 1-naphthol with Fast Red TR, and measuring the resulting color. The test is performed in the presence and absence of tartrate. Reaction rates can be continuously monitored, and their difference is proportional to acid phosphatase activity that is inhibited by tartrate. Results for sera with normal and increased acid phosphatase activities are presented and three different methods for acid phosphatase are compared. The kinetic blank used in the reaction eliminates all nonenzymatic contributions to substrate splitting.
Evaluation of a New Radioimmunoassay Method for Carcinoembryonic Antigen in Plasma, with Use of Zirconyl Phosphate Gel
Authors: Chu Tsann Ming , Reynoso Gustavo 
Published: January 2020

Abstract
A radioimmunoassay of carcinoembryonic antigen in plasma is described and evaluated. The assay can be easily performed and implemented in a clinical laboratory. Assessed by Rodbard’s statistical quality-control procedure, the assay is shown to be highly sensitive, precise, and reproducible.
Determination of Copper in Fingernails by Atomic Absorption with the Graphite Furnace
Authors: Barnett William B , Kahn Herbert L 
Published: January 2020

Abstract
Two atomic absorption techniques, acid digestion followed by conventional flame analysis and direct analysis of solid samples with the graphite furnace, were compared for the determination of copper in fingernails. Nail samples, from 11 persons, containing between 5 and 50 µg/g of copper, were analyzed by both methods. There was good correlation between results of the two. The furnace requires less sample preparation, has good sensitivity, and solid samples may be directly analyzed.
Modified Method for Estimating the Phosphatidyl Choline:Sphingomyelin Ratio in Amniotic Fluid, and Its Use in the Assessment of Fetal Lung Maturity
Authors: Sarkozi Laszlo , Kovacs Hanna N , Fox Howard A , Kerenyi Thomas 
Published: January 2020

Abstract
Phospholipids of amniotic fluid were extracted, separated by thin-layer chromatography, detected with acidified ammonium sulfate, and charred; the phosphatidyl choline and sphingomyelin fractions were quantitated by transmission densitometry. The densities were recorded as integrator trace units. We used commercially available precoated plates and a solvent system to eliminate the interference of phosphatidyl serine. The procedure used for visualization eliminated the irritating and corrosive effects of the 50% sulfuric acid spray used in other methods. Omission of the acetone precipitation step decreased assay time without loss of accuracy. In 117 amniotic fluid samples obtained before delivery of infants who subsequently did not develop respiratory distress syndrome (RDS) the geometric mean density ratio of phosphatidyl choline: sphingomyelin was 3.1, range 1.8 to 8.6. In three pre-delivery amniotic fluid samples, density ratios of less than 1.5 were found. Those infants developed RDS.
Photometric Assay of Dopamine-β-Hydroxylase Activity in Human Blood
Authors: Nagatsu Toshiharu , Udenfriend Sidney 
Published: January 2020

Abstract
We describe a simple, rapid, and sensitive procedure for measuring dopamine-β-hydroxylase activity in human blood. The assay is based on the enzymatic conversion of tyramine to octopamine [1-(p-hydroxyphenyl)-2-aminoethanol], which is then oxidized to p-hydroxybenzaldehyde and determined photometrically. Activities are assayed on 2-20 µl of human serum or plasma obtained from fingertip blood samples. The method should prove useful in clinical studies, including the field of pediatrics.
Rapid Lipid-Staining Procedure for Paper Electrophoretograms
Authors: Naito Herbert K , Lewis Lena A 
Published: January 2020

Abstract
We describe a rapid, reliable staining procedure for lipoproteins on paper electrophoretograms. Staining time, is 2.5 h in an acetone-water (1:1, by vol) solution of Oil Red O dye (0.4 g/liter). Results agree well with those obtained by the conventional overnight staining technique
Semiautomated Enzymatic Method for Determining Serum Triglycerides by Use of the Beckman "DSA 560"
Authors: Mourad Nabeeh , Zager Ronald , Neveu Peter 
Published: January 2020

Abstract
Triglycerides are hydrolyzed to glycerol and fatty acids with alcoholic potassium hydroxide, and total glycerol (that originally present plus that released by hydrolysis) is determined enzymatically, with use of a Beckman "Discrete Sample Analyzer 560," at the rate of 120 samples per hour. Absorbance decrease is measured at 340 nm, and the final results are printed out directly, in milligrams per 100 ml. Results of this procedure were compared with those obtained by a manual method. Standard deviations for more than 200 determinations of commercial normal and abnormal quality-control reference sera during the course of a year were 2.00 and 2.31 mg/100 ml (C.V, 1.6 and 2.4%)
Use of Ferric Ammonium Sulfate in Serum Cholesterol Determination
Authors: Feng Hsien-wen , Pi Chung-miu , Wang Rong-bor , Chen Li-chuen 
Published: January 2020

Abstract
Ferric ammonium sulfate, which has advantages over ferric chloride in that it is not deliquescent and does not evolve hydrogen chloride upon addition of sulfuric acid, was used in the ferric chloride—sulfuric acid method for serum cholesterol determination. Comparable results are obtained with these iron salts
Radioassay of Serum Folate, with Use of a Serum Blank and Nondialyzed Milk as Folate Binder
Authors: Tajuddin Mohammed , Gardyna Henry A 
Published: January 2020

Abstract
Serum folate determination by this method requires incubation of 0.1 ml of serum (or standards) with nondialyzed milk and then with tritium-labeled folate. A serum blank corrects for nonspecific binders present in the serum. Unbound folate is removed with hemoglobin-coated charcoal. The standard deviation of the results is ±0.2 µg/liter, and more than 90% of folate added to the serum is accounted for analytically. Serum folate concentrations as determined by this method agree with those obtained by microbiological assay (Lactobacillus casei), and our method is faster, simpler, and more accurate than other radioassay methods
Improved Manual and Automated Colorimetric Determination of Serum Glucose, with Use of Hexokinase and Glucose-6-Phosphate Dehydrogenase
Authors: Coburn Holly J , Carroll James J 
Published: January 2020

Abstract
A previously reported assay for serum glucose, in which hexokinase and glucose-6-phosphate dehydrogenase were used, was improved to replace the light-sensitive phenazine methosulfate with "diaphorase," providing a one-reagent system. The assay system was automated for use with standard AutoAnalyzer equipment and evaluated at 40 and 60 samples per hour with a 2:1 sample-to-wash ratio. Sensitivity, precision, accuracy, and sample interaction were quite satisfactory at both sample rates. The assay benefits from the inherent advantages of the reaction mechanism: sensitivity, specificity, NADP regeneration, and freedom from dialysis
Biological Activity of a Semisynthetic Flavonoid, O-(β-Hydroxyethyl)rutoside: Light-Scattering and Metabolic Studies of Human Red Cells and Platelets
Authors: ten Cate J W , van Haeringen N J , Gerritsen J , Glasius E 
Published: January 2020

Abstract
The effect of O-(β-hydroxyethyl)-rutoside (HR) on human erythrocyte and platelet functions is reported. Only high concentrations of the compound distinctly inhibited red cell and platelet aggregation induced by ADP and epinephrine. Lower concentrations of HR inhibit [14C8]adenosine incorporation into red cells as well as into platelets. Inhibition occurs at both 0°C and 37°C, presumably because diffusion of [14C8]adenosine is hindered. Phosphorylation of [14C8] adenosine by the platelets is not inhibited by HR. The inhibition of red cell aggregation is reversed by washing the cells with plasma. Collectively, these findings indicate an effect of the compound at the site of the membrane, independent of cellular metabolism
Use and Interpretation of Common Statistical Tests in Method-Comparison Studies
Authors: Westgard James O , Hunt Marian R 
Published: January 2020

Abstract
We have studied the usefulness of common statistical tests as applied to method comparison studies. We simulated different types of errors in test sets of data to determine the sensitivity of different statistical parameters. Least-squares parameters (slope of least-squares line, its y intercept, and the standard error of estimate in the y direction) provide specific estimates of proportional, constant, and random errors, but comparison data must be presented graphically to detect limitations caused by nonlinearity and errant points. t-test parameters ( bias, standard deviation of difference) provide estimates of constant and random errors, but only when proportional error is absent. Least-squares analysis can estimate proportional error and should be considered a prerequisite to t-test analysis. The correlation coefficient (r) is sensitive only to random error, but is not easily interpreted. Values for r, t, and F are not useful in making decisions on the acceptability of performance. These decisions should be judgments on the errors that are tolerable. Statistical tests can be applied in a manner that provides specific estimates of these errors
Cooperative Survey of "SMA" Analyzers in Wisconsin—A Method of Improving Interlaboratory Performance
Authors: Laessig Ronald H , Schwartz Thomas H , Paskey Toni A 
Published: January 2020

Abstract
A state-wide cooperative quality-control program for automated multichannel analytical systems is described. The survey benefits participating laboratories by providing, through regular comparison, a means of improving interlaboratory precision. A common lot of reference material used for a large group of similar multichannel analyzers is shown to significantly improve their precision. The study delineates components of interlaboratory variation resulting from the inconsistency of the reference materials and from the inherent precision of the analyzers. Errors in the assay values of commercial controls and reference sera, as well as problems of homogeneity in these products, are documented. These errors make some form of regular interlaboratory comparison an essential element of a total quality-control program
Computer-Controlled Instrument System for Sequential Clinical Chemical Testing. II. Evaluation of Instrumental Performance
Authors: Toren E Clifford , Mohr Stephen A , Busby Michael G , Cembrowski George S 
Published: January 2020

Abstract
The instrumental system described [Clin. Chem.19, 1114 (1973)] is evaluated in manual, partially automated, and totally automated modes to measure system and individual component performance. Excellent accuracy and precision were observed, hence the system is judged suitable for most analytical applications. Results are: wavelength accuracy and reproducibility in automated mode: ±0.004 nm and ±0.1 nm, respectively; photometric accuracy and precision: ca. 0.8% relative and ±0.007 A, respectively, in both the manual and automated modes; and ratemeter accuracy and precision: ±0.4% relative and ±0.873 (SD) mV/min (or mA/ min), respectively, for standard synthetic ramps and ±1.2% relative and ±2.2 (SD) mV/min, respectively, under actual laboratory conditions for rates in the range of 1 to 200 mV/min. Automated experiments are made without human intervention after the samples are loaded.
Isoenzymes of Liver Alkaline Phosphatase in Serum of Patients with Hepatobiliary Disorders
Authors: Rhone Douglas P , White Florence M , Gidaspow Helene 
Published: January 2020

Abstract
The isoenzymes of alkaline phosphatase (ALP; EC 3.1.3.1) present in the [unknown]sera of 116 patients with hepatobiliary disease were studied by electrophoresis on cellulose acetate. Individual liver isoenzyme bands were identified and quantitated by densitometric scanning. The occurrence and magnitude of increase of the isoenzyme bands of liver ALP (α2 alone or α1 and α2) are related to diagnosis. Of the cases studied, 30% showed only the α2 band of liver ALP. A couplet of liver isoenzyme bands (α1 and α2) was seen in 70% of the cases studied. The isolated α2 band occurred in 26 of 36 patients with viral hepatitis and in two patients with hepatic infarction. Most patients with other liver diseases showed the α1 and α2 couplet. The serum pattern of liver ALP is related to total ALP, age, ABO blood group, and serum bilirubin concentration. The α1 band is markedly increased in patients with granulomatous hepatitis and carcinoma metastatic to the liver. The findings are related to previous work, and their implications are discussed.
Rapid Method for Measurement of Oxygen in Human Blood
Authors: Butts William C , Kenny Margaret A , McCoubrey Pamela G 
Published: January 2020

Abstract
The "Lex-O2-Con" (Lexington Instrument) for measuring oxygen in blood is technically simpler to use and three times as rapid as the traditional Van Slyke instrument. Results obtained with both instruments for 90 blood samples from 18 patients were satisfactory (r = .997). The coefficient of variation for the Lex-O2-Con instrument was 0.6%.
Improved Method for Determination of Triglycerides in Serum
Authors: Neri Bruce P , Frings Christopher S 
Published: January 2020

Abstract
We describe a new method for determination of serum triglycerides that is based on the original method of Fletcher [Clin. Chim. Acta22, 393 (1968)]. We have modified Fletcher’s reagents so that it is possible to saponify serum triglycerides in 5 min at room temperature (about 24 °C) instead of 60-70 °C for 15 min and to produce the final color in 15 min at 60-70 °C instead of 30 min at 50 ° C. The new reagents are stable for at least two months. The correlation coefficient obtained for the two methods (n = 107 sera) was 0.98. When the t test and F test were applied to these data, no significant difference in accuracy and precision was found at the 95% confidence level. The coefficient of variation (day-to-day) for the new method is 7.0%.
Radioimmunoassay of Insulin in Serum and Plasma
Authors: Feldman Jerome M , Chapman Barbara A 
Published: January 2020

Abstract
Paired serum and plasma samples from subjects were analyzed to determine if there was a difference in the insulin content of serum and plasma. Although there was no difference in the serum and plasma insulin concentrations in the samples as a group, there were differences in the serum and plasma insulin concentrations in individual subjects. Recovery of radioimmunoassayable insulin from clotted or heparinized blood is less than the recovery from serum or plasma, apparently because of association of insulin with the blood cells. Serum and plasma insulin concentrations are not altered when blood stands at room temperature for as long as 4 h. Storage at -20 °C for 28 months results in similar decreases in the insulin content of serum (74%) and plasma (76%). We conclude that one should consistently use either serum or plasma for insulin measurements in individual patients.
NADH Preparations as They Affect Reliability of Serum Lactate Dehydrogenase Determinations
Authors: Berry Arnold J , Lott John A , Grannis George F 
Published: January 2020

Abstract
We observed large variations in the activity of lactate dehydrogenase (EC 1.1.1.27) in serum when random lots of NADH were used in its determination. The imprecision, caused by variable amounts of lactate dehydrogenase inhibitor in the NADH preparations, was greatly lessened by using only a single lot of NADH; reliability was improved further by selecting an NADH preparation having a negligible amount of inhibitor. A method is described for assessing the quality of commercial NADH preparations, so as to have a satisfactory reagent and to maintain continuously comparable results over an extended period of time. The results have possible relevance for proposed governmental regulation of commercial kits and reagents used for clinical laboratory testing, and for improved intraand inter-laboratory comparability of lactate dehydrogenase determinations.
A New Micromethod for Determination of Protein in Cerebrospinal Fluid and Urine
Authors: Pesce Michael A , Strande Carl S 
Published: January 2020

Abstract
We developed a new micro-scale procedure for determination of protein in cerebrospinal fluid and urine. The sample (50 µl) is mixed with a trichloroacetic acid—Ponceau S dye solution. The proteins, together with a proportional amount of dye, are precipitated and the red precipitate is dissolved in dilute sodium hydroxide solution, giving a violet-colored solution. This color, linearly proportional to the amount of protein present (up to 150 mg/dl), is measured spectrophotometrically at 560 nm. By varying the sample size alone, protein concentrations up to 1500 mg/dl can be measured. The detection limit for the method is 2 mg/dl of sample. Precipitation of the proteins is independent of temperature and albuminbinding compounds, and is not appreciably affected by the albumin—gamma globulin ratio.
Proposed Standard Method for Measuring Lipase Activity in Serum by a Continuous Sampling Technique
Authors: Tietz Norbert W , Repique Eliseo V 
Published: January 2020

Abstract
A method is presented for measuring lipase activity in serum by use of either triolein or olive oil as substrate. The method requires 3 to 8 min for each measurement and 5 to 8 min for initial set-up. The reaction mixture is maintained at the optimum pH of 8.8 by automatic addition of sodium hydroxide (10 mmol/liter) with a " pH-Stat." Amount of sodium hydroxide delivered per unit time reflects lipase activity. When reaction conditions—such as pH, substrate concentration, emulsifier concentration, and type and concentration of added bile salts—were made optimal, the reaction kinetics were zero order. Data presented indicate that adding sodium glycocholate prevents inactivation of lipase and does not lead to activation of this enzyme. Comparative studies, in which triolein and olive oil, respectively, are used as substrates show that triolein is the superior substrate for lipase, but olive oil can be substituted for triolein for routine clinical laboratory use. The suggested upper limit of normal is 200 and 160 U/liter for triolein and olive oil substrates, respectively.
Increased Lactate Dehydrogenase Isoenzyme-5 (LD5) Activity Evidently Caused by Persistent Diaphragmatic Pressure on a Congested Liver
Authors: Henderson A R , Kostuk W J , Griffiths J C 
Published: January 2020

Abstract
A patient with congestive cardiac failure owing to severe bradycardia had a transvenous cardiac pacemaker inserted, resulting in complete alleviation of the cardiac failure. Later, however, the pacer became displaced high into the superior vena cava, where it ceased to pace the heart but instead stimulated the right phrenic nerve. Consequently the rapid movement of the right hemidiaphragm pressing on the dome of an increasingly congested liver, for about one week before hospital admission, was associated with an unusually elevated LD5 (lactate dehydrogenase, EC 1.1.1.27) activity in the serum.
Preparation of Amine Salts of Thymolphthalein Monophosphate and Their Use for Measuring Phosphatase Activity
Authors: Erikson John M , Biggs Homer G 
Published: January 2020

Abstract
An easy and quick preparation of amine salts of thymolphthalein monophosphate is described. All of the salts prepared are stable, nonhygroscopic, soluble powders. The 2-amino-2-methyl-1,3-propandiol salt is preferred for use as a substrate for measuring phosphatase activities because of its high solubility and easy preparation.