bluuebunny/crossref_metadata_2025_split huggingface dataset:
Use of blood specimens collected on filter paper in screening for abnormal hemoglobins.
Authors: Schmidt R M , Brosious E M , Holland S , Wright J M , Serjeant G R 
Published: January 2020

Abstract
Both cellulose acetate electrophoresis and citrate agar electrophoresis were performed on 834 blood samples collected on filter paper in Jamaica and shipped for testing to the National Hemoglobinopathy Standardization Laboratory at the U.S. National Center for Disease Control. Additionally, 30 blood samples collected locally were stored on filter paper, in microhematocrit capillary tubes, and as whole blood specimens; at selected times the samples were tested for stability to determine the best sample-collection technique for hemoglobin electrophoresis. Results were most nearly accurate when both cellulose acetate electrophoresis and citrate agar testing were used. The methods are easy to perform, but results are unreliable if the blood samples on filter paper are stored at 4 degrees C for longer than two weeks before they are tested.
Automated enzymic determination of ethanol in blood, serum, and urine with a miniature centrifugal analyzer.
Authors: Hadjiioannou T P , Hadjiioannou S I , Avery J , Malmstadt H V 
Published: January 2020

Abstract
We describe an automated spectrophotometric reaction-rate method for determination of ethanol in serum and urine with a miniature centrifugal analyzer. The theanol is selectively oxidized in the presence of alcochol dehydrogenase and NAD+ to form NADH, which is measured by the rate of change of its absorbance. Reaction rates are determined automatically, and unknown concentrations are calculated from a computer-generated working curve based on aqueous ethanol standards. Blood, serum, or urine specimens need not be deproteinized. The method permits duplicate analysis of at least 30 samples per hour. Coefficients of variation and relative errors are about 2-3% for ethanol concentrations of 0.3-3.0 mug per 2 mul of sample. Analytical recovery of ethanol added to serum is 92-103% (average, 98.5%). Comparisons with distillation-oxidation, gas-chromatographic, and conventional enzymic procedures give satisfactory agreement.
Assessment of interference by aspirin with some assays commonly done in the clinical laboratory.
Authors: Routh J I , Paul W D 
Published: January 2020

Abstract
We have assessed the interference of acetylsalicylic acid (aspirin) with some common clinical laboratory assays, because of its widespread use and reported interference. The therapeutic regimens involved ingestion of 10 325-mg tablets daily for three days or eight tablets for five days or two weeks. Twenty-one commonly done determinations were run on control sera, and sera were collected during and after drug therapy. Significant changes in t-test values, indicating the significance of the standard deviation of the difference between controls and specimens drawn after drug therapy, were observed for chloride (increased), and for total protein, calcium, cholesterol, uric acid, bilirubin, and thyroxine (decreased). Aspirin therapy depressed the apparent concentrations of these constituents progressively in the three-day regimen and initially in the long-term regimens, followed by recovery toward zero t-values at the end of the longer regimens.
Serum theophylline analysis by high-pressure liquid chromatography.
Authors: Evenson M A , Warren B L 
Published: January 2020

Abstract
We have developed and evaluated a rapid, high-pressure liquid-chromatographic method for theophylline in serum. Only 0.2 ml of serum is required for each determination, and the sensitivity of this method is 0.5 mg/liter. This method, involving liquid extraction and silica adsorption chromatography, provides adequate selectivity, accuracy, and precision for routine or research applications. Little sample preparation is required before chromatography. We found no endogenous or exogenous interferences. Use of beta-hydroxypropyl theophylline as the internal standard provides reproducible results for this micro-scale method.
Gas-chromatographic method for acetaminophen (N-acetyl-p-aminophenol) based on sequential alkylation.
Authors: Dechtiaruk W A , Johnson G F , Solomon H M 
Published: January 2020

Abstract
A gas-chromatographic procedure for acetaminophen is described in which the drug is chromatographed as the O-heptyl-N-methyl derivative. This derivative is prepared by a sequential alkylation procedure in which the phenolic hydroxyl group of the parent compound is alkylated off-column with heptyl iodide and the amide group is derivatized on-column by reaction with trimethylanilinium hydroxide. The internal standard, N-propionyl-p-aminophenol, is subjected to the same derivatization procedure. This gas-chromatographic procedure correlates well with conventional colorimetric and spectrophotometric procedures for acetaminophen and is more sensitive. Within-run precision (CV) was 2.0% at a serum concentration of 10.0 mg/liter (n = 10) and between-run precision was 4.0% over a period of eight months. This method is particularly applicable to studies of the pharmacokinetics of acetaminophen.
Gas-chromatographic quantitation of theophylline in small volumes of plasma.
Authors: Perrier D , Lear E 
Published: January 2020

Abstract
We describe a rapid procedure for quantitating theophylline in 100-mul plasma samples by use of a gas-liquid chromatograph equipped with a flame ionization detector. This methos is especially useful for monitoring theophylline concentrations in serum or plasma of infants, because sufficiently large blood samples can be readily obtained from a heel prick. The method is specific for theophylline in the presence of caffeine, theobromine and phenobarbital. For plasma concentrations equal to or greater than 5 mg/liter the average daily coefficient of variation was less than 7% while the coefficient of variation from day to day was less than 11%. The same approach can also be used to measure concentrations of phenobarbital in small volumes of plasma or serum, and is readily adapted to determination of theophylline and phenobarbital in larger samples.
alpha1-Fetoprotein measurement in blood spotted on paper: discriminating test for hereditary tyrosinemia in neonatal mass screening.
Authors: Grenier A , Bélanger L , Laberge C 
Published: January 2020

Abstract
We describe an electroimmunodiffusion technique for measuring alpha1-fetoprotein in blood spotted on chromatography paper. The system is being used as a complementary test in a neonatal mass-screening program for detection of inborn metabolic diseases in the Province of Quebec. In a series of 102 cases of neonatal hypertyrosinemia, the test has proven to be highly discriminative for hereditary tyrosinemia. It has permitted early detection of eight cases of this disease, including two that would have been missed by the previously used screening procedure, tyrosine measurement only. The test not only virtually eliminates the risk of misdiagnosis or missed diagnosis, but also permits earlier diagnosis of hereditary tyrosinemia and considerably reduces the follow-up work required for newborns with transitory tyrosinemia. The AFP test is simple, fast, practical, and inexpensive. Combined with tyrosine determination, it constitutes an optimal device for mass screening of hereditary tyrosinemia.
Anomalous behavior of glutathione reductase on dilution.
Authors: Spooner R J , Delides A , Goldberg D M 
Published: January 2020

Abstract
Serum glutathione reductase activity decreases on standing at room temperature. Dilution of the sample slows this decay in sera from patients with a variety of clinical disorders, and reverses the inactivation in sera from patients with liver or biliary tract disease. Prolonged contact with dithioeythritol or acetate buffer, pH 6.4, at 4 degrees C prevents spontaneous inactivation of the native serum and abolishes the effect of dilution. These hitherto unreported phenomena are a source of potential inaccuracy in assays for this enzyme. The inactivation may be the result of conformational folding with "burying" of active sites, or of molecular aggregation brought about by hydrogen bonding or disulfide bond formation.
Evaluation of a new system ("Corvac") for separating serum from blood for routine laboratory procedures.
Authors: Spencer W W , Nelson G H , Konicki K A 
Published: January 2020

Abstract
We evaluated the suitability of a new system ("Corvac," Corning) for rapid, complete separation of cell-free serum from whole blood. Twenty-one different clinical chemical procedures were performed on about 1150 paired blood samples, several by more than one method, to afford a more comprehensive evaluation. The tube of clotted blood collected in the conventional manner ("Vacutainer") underwent a double centrifugation and served as the control sample, while its paired specimen collected in the new system was processed by a single centrifugation. We evaluated significant differences between the means of the paired samples, the standard deviations of the differences between the means, and the bias of the means for the values of each constituent for each collection method. For several tests we observed differences that were statistically but not clinically significant. Only in the case of lactate dehydrogenase were large differences consistently demonstrated.
Lactate dehydrogenase activities in serum and plasma.
Authors: Rothwell D J , Jendrzejczak B , Becker M , Doumas B T 
Published: January 2020

Abstract
We investigated lactate dehydrogenase activity in serum and plasma because of the conflicting data found in the literature. We assayed serum, platelet-rich, and platelet-poor plasma by two colorimetric endpoint methods and by an ultraviolet kinetic procedure. Platelet-poor plasma and serum had essentially the same activities by all three methods, whereas the activity in platelet-rich plasma plasma averaged fourfold that in platelet-poor plasma or serum when the assay was performed under conditions that result in lysis of platelets and release of their lactate dehydrogenase. When measurements were performed in platelet-rich plasma under conditions that prevented lysis of platelets, all three types of specimens gave the same results. This occurred when the osmolality of the reaction mixture was about 240 mOsm/kg of water. At an osmolality of about 120 mOsm, the activity of platelet-rich plasma was substantially lower than that of platelet-poor plasma or serum. If plasma must be used, the sample must first be centrifuged (3000 X g, 15 min) to provide a platelet-free plasma.
Simple determination of 3alpha-hydroxy fraction and 3beta-hydroxy fraction of urinary 17-ketosteroids.
Authors: Yamaguchi Y , Hayashi C , Kumahara Y 
Published: January 2020

Abstract
We describe a method for determination of the 3alpha-hydroxysteroid fraction and 3beta-hydroxysteroid fraction of 17-ketosteroids in urine. The method includes enzymatic hydrolysis with beta-glucuronidase and extraction with ethyl acetate and color development of 3beta-hydroxysteroids by 3beta-hydroxysteroid oxidase and of total 17-ketosteroids by the Zimmermann reaction. The value for 3alpha-hydroxysteroids is calculated by subtracting the value for 3beta-hydroxysteroids from the value for total 17-ketosteroids. Recovery was assessed and results compared with those by an accepted method. Results were satisfactory for measuring these fractions of 17-ketosteroids.
Concurrent determination of total serum calcium and magnesium by thermometric titration with ethylenediaminetetraacetate.
Authors: Callicott R H , Carr P W 
Published: January 2020

Abstract
Total serum calcium and magnesium may be determined in one thermometric titration, with disodium ethylenediaminetetraacetate as the titrant. A 1-ml serum sample is diluted with 1 ml of tris(hydroxymethyl)aminomethane buffer (pH 8) and titrated at a constant rate with a motorized syringe buret. Results by the thermometric method compared well with those by atomic absorption spectroscopy.
Effect of reaction initiator on human lactate dehydrogenase assay.
Authors: Buhl S N , Jackson K Y , Lubinski R , Vanderlinde R E 
Published: January 2020

Abstract
Human lactate dehydrogenase isoenzymes I and V have decreased activities when the reaction is initiated with lactate. No loss in lactate dehydrogenase I activity was found when the reaction was initiated with enzyme or NAD+. For lactate dehydrogenase V an NAD+-initiated reaction, as compared to an enzyme-initiated reaction, yields lower activity in sodium pyrophosphate buffer but higher activity in tris(hydroxymethyl)aminomethane buffer. Both isoenzymes have higher lactate-to-pyruvate activity when assayed in the latter buffer than when assayed in the former. Human lactate dehydrogenase V (but not I) exhibited different activities when assayed with lactate from two different commercial sources. Human lactate dehydrogenase assayed by the pyruvate-to-lactate reaction is not affected by the choice of reaction initiator.
Reduction of sample size on the Technicon SMA 6/60 continuous-flow analyzer.
Authors: Shihabi Z K , Turner J C 
Published: January 2020

Abstract
The manifold of the Sequential Multiple Analyzer SMA 6/60 (4 + 2) has been modified to decrease serum sample size to 90 mul, by using a common diluent for all six channels and recycling the discard of each dialyzer into the next one. The modification can be made in less than 4 h without the need for any additional parts; the modified manifold requires one-third fewer pump lines and fewer reagents, thus reducing operating costs and simplifying instrument maintenance, while retaining the same precision, speed, low carryover, and linearity of the production model.
Evaluation of benefits of screening tests done immediately on admission to hospital.
Authors: Durbridge T C , Edwards F , Edwards R G , Atkinson M 
Published: January 2020

Abstract
Evidence was sought of improved inpatient progress and reduced hospital costs when a battery of investigations were done at the time a patient was admitted to hospital. The outcome in 500 admission-tested patients was compared with that in two other groups of 500 control patients. No significant differences were found among the three groups in a variety of indices of inpatient progress. Because of an estimated 64% increase in the cost of investigating inpatients with admission testing, the total cost of hospital care was increased by about 5%. Under the conditions of this study, admission testing added to the cost of hospitalization, without associated evidence of benefit to the patient.
Rates of disappearance from plasma of enzymes labeled by coupling with a radioactive lodo-ester.
Authors: Qureshi A R , Wilkinson J H 
Published: January 2020

Abstract
Lactate dehydrogenase-5 and creatine kinase from rabbit muscle were labeled by coupling with N-hydroxysuccinimidyl 3-(4'-hydroxy-[3',5'-125I]diiodophenyl)propionate. After purification, the analytical recovery of catalytically-active labeled enzyme averaged 90% for lactate dehydrogenase, 81% for creatine kinase. The labeled enzymes were injected intravenously into rabbits and disappearance from plasma of catalytic activity and radioactivity was measured. The disappearance curves for lactate dehydrogenase-5 differed considerably from those observed with the enzyme labeled by direct iodination. The discrepancy was due to rapid hydrolysis in vivo of the labeled amide-enzyme linkage, because about 50% of the injected radioactivity appeared in the urine as 125I-labeled 3-(4'-hydroxy-3',5'-diiodophenyl)propionic acid within 4-8 h of injection. Similar outputs were observed after administration of this acid to rabbits. The free acid was also detected in the urines of rabbits within 4-8 h of the intravenous injection of creatine kinase labeled similarly. We conclude that this method of labeling is unsuitable for preparing radioactive enzymes for study of their catabolism.
Addition of triglyceride to serum for use in quality control and reference.
Authors: Bonderman D P , Proksch G J , Bonderman P W 
Published: January 2020

Abstract
We describe a simple method in which a water-soluble mixture of triocatanoin and a surfactant, "Triton X-114," are used in preparing solutions of triglycerides (triacylglycerols) in either human serum, solutions of albumin, or water. Analytical recovery added triglyceride was quantitative by two methods. The addition did not affect results of analyses for 18 other commonly measured constitutents of serum. When the triglyceride was added to either lipid-depleted human serum or bovine serum albumin solution and lyophilized, subsequent solutions were clear. The triglyceride/protein preparation was stable in lyophilized form for a year and in reconstituted serum for five days at 5 degrees C. Aquenous solutions appear to be stable indefinitely at room temperature.
Structure of some aliphatic dicarboxylic acids found in the urine of an infant with congenital lactic acidosis.
Authors: Lindstedt S , Norberg K , Steen G , Wahl E 
Published: January 2020

Abstract
Gas chromatography/mass spectrometry was used to identify a series of acids in urine and serum from a child who died 26 h after birth in severe metabolic acidosis with high lactate excretion. cis-5-Decene-1, 10-dioic acid and cis-5-dodencene-1, 12-dioic acid were synthesized and used as references. The following acids were found: hexane-1,6-dioic acid, octane-1,8-dioic acid, decane-1,10-dioic acid, dodecane-1,12-dioic acid, cis-5-decene-1,10-dioic acid, cis-5-dodecen-1,12-dioic acid, cis-5-tetradecene-1,14-dioic acid, trans-3-decene-1,10-dioic acid, and trans-3-dodecene-1,12-dioic acid. The concentration of C6 to C14 acids in the patient's urine was 3.7 mol/mol of creatinine; it was less than 0.2 mol/mol of creatinine in eight normal newborns and approximately 0.1 mol/mol of creatinine in a case of fructose-1,6-biphosphatase deficiency with lactic acidosis. 5-cis-Dodecenedioic acid was present in highest concentration: 1 mol/mol of creatinine in urine and 61 mumol/liter in serum. We propose that impaired beta-oxidation, probably at the acyl-CoA-dehydrogenase step, resulted in the formation of the observed acids. The parents were consanguineous, and a sibling died with the same clinical picture, which suggests a genetic defect.
Improved method for determining serum protein concentrations in the far ultraviolet.
Authors: Ressler N , Gashkoff M , Fischinger A 
Published: January 2020

Abstract
We examined the feasibility of measuring absorbance in the far ultraviolet for serum protein determination with a medium-priced, double-beam spectrophotometer. The method has been simplified by using an automatic dilutor to dilute the serum, and a flow-through cell and recorder in conjunction with the spectrophotometer. Because it is only necessary to dilute the serum and determine its absorbance, the procedure is quite rapid. As compared to the biuret reaction, interferences from hemolysis have been about halved. Interferences owing to light scattering by turbid sera have also been appreciably decreased by use of an anionic detegent (sodium dodecyl sulfate) as a serum diluent. Comparisons of the present method to the biuret and Kjeldahl methods indicate that it is relatively accurate, and is practical for routine use.
Correlation between estrogen receptor protein and carcinoembryonic antigen in normal and carcinomatous human breast tissue.
Authors: Menendez-Botet C J , Nisselbaum J S , Fleisher M , Rosen P P , Fracchia A , Robbins G , Urban J A , Schwartz M K 
Published: January 2020

Abstract
We determined estrogen receptor protein and carcinoembryonic antigen in cytosols prepared from 189 human breast carcinoma tissues, 85 benign or normal breast biopsies, and 101 tissue specimens metastatic from breast carcinoma. Carcinoembryonic antigen was observed in 70% of the primary carcinomatous tissues, 15% of the benign or normal specimens, and 51% of the metastases. Ninety-six of the 189 primary carcinomatous specimens with increased concentrations of carcinoembryonic antigen were also positive for estrogen receptor protein, whereas 67 of the 72 benign or normal biopsies with low concentrations of carcinoembryonic antigen were also negative for estrogen receptor protein. All five fenign specimens with positive estrogen receptor protein and normal carcinoembryonic antigen concentrations were from fibroadenomas. The concordance between estrogen receptor protein and carcinoembryonic antigen in the primary carcinomatous tissue was 66%, in metastatic carcinoma 51%, and in benign and normal tissue 85%.
End-point parameter adjustment on a small desk-top programmable calculator for logit-log analysis of radioimmunoassay data.
Authors: Hatch K F , Coles E , Busey H , Goldman S C 
Published: January 2020

Abstract
We describe an improved method of logit-log curve fitting, by adjusting end-point parameters in radioimmunoassay studies, for use with a small desk-top programmable calculator. Straight logit-log analyses are often deficient because of their high sensitivity to small errors in the end-point parametes B0 and NSB (the actual measured activity in the tubes). The literature suggests techniques for adjusting these end-point parameters, but they require too much computing time and programming space to be used with a desk-top programmable calculator. The extension to the logit-log model presented here is easily handled by the programmable calculator and provides a good estimate of the change required in B0 and NSB to obtain a better fit. The program requires 1.5 min to run on our desk-top programmable calculator, and has resulted in improved data analysis for all of the 11 types of radioimmunoassay studied.
Unsuitability of porcelain crucibles for dry ashing of biological tissues for calcium analysis.
Authors: Meyer M , Meyer R A 
Published: January 2020

Abstract
At temperatures required for complete release of calcium from beef liver by dry ashing, porcelain crucibles release significant amounts of calcium into the ash, which leads to erroneously high calcium values in the samples. Heated, empty porcelain crucibles do not show released calcium. Both fused silica and platinum crucibles fail to show any significant interaction with the sample. Samples dry-ashed in fused silica crucibles were compared to samples subjected to the hot trichloracetic acid-acetic acid extraction method, which gave results not significantly different if the tissue was first minced. However, calcium was incompletely extracted by the hot acid from whole segments of liver weighing about 0.2 g.
Simplified radioimmunoassay for triiodothyronine: evaluation of a new commercial kit.
Authors: Balachandran S , Moses D C , Sisson J C , Patel S R 
Published: January 2020

Abstract
A new triiodothyronine (T3) radioimmunoassay kit offers simplicity of method, short incubation time, specificity, and reproducibility. 125I-labeled T3 and unknown serum (or standard) are added to alkaline buffered (pH 12.4) Sephadex G-25 columns; the T3 is freed of proteins with an alkaline buffer wash, antiserum is added, and the columns are incubated at room temperature for 2 h. "Free" hormone (i.e., unbound to antiserum) remains on the column after a second wash. The radioactivity on the column is counted and related to the total activity added. The T3 standards produced a straight line on log-logit plot; reactivity of analytical-grade thyroxine was 0.6% on weight basis; and the analytical recovery of T3 added to a T3-free serum was complete. Euthroid, hyperthyroid, and hypothyroid ranges were 0.74-2.64, 2.91-7.52, and 0-1.21 mug/liter, respectively. These values correlated well with both the clinical status of patients and with values obtained by an established radioimmunoassay method. The procedure is simply done; results may be obtained in less than 4 h.