bluuebunny/crossref_metadata_2025 huggingface dataset:
Turbidimetric immunoassay of serum C-reactive protein.
Authors: Otsuji S , Shibata H , Umeda M
Published: January 2020

This rapid, reliable equilibrium turbidimetric immunoassay for serum C-reactive protein involves a potent monospecific antibody. Polyethylene glycol-6000 to accelerate and enhance the immunoprecipitation reaction, and Tween-20 surfactant to lower and stabilize the sample blank values. Grossly lipemic, icteric, or hemolyzed sera can be assayed. Values up to about 220 mg/L, for which the standard curve is linear, can be measured without sample dilution. Results by the proposed method and by radial immunodiffusion (r 0.989) or laser nephelometry (r = 0.957) correlated well. Analytical recovery averaged 101.3%. Within-, between-, and day-to-day CVs ranged from 0.9% to 3.5%, 0.8% to 5.5%, and 1.9% to 4.8%, respectively. The method is demonstrably superior to radial immunodiffusion or nephelometry. Any spectrophotometer that can measure turbidimetrically at 340 nm can be used.
Interference in a chromogenic alpha-amylase assay caused by dye-labeled oligosaccharide-induced precipitation of lipoprotein.
Authors: Wickus G G , Dukerschein R O , Pierce J R , Davis K D
Published: January 2020

We examined the mechanism by which hypertriglyceridemia interferes with the Roche Diagnostics "Amylochrome" procedure for measurement of amylase in lactescent samples with normal and above-normal amylase activity. The serum blank recommended in the Amylochrome protocol to compensate for lactescence remains inappropriately turbid, compared with the test, and is partly responsible for the underestimation of amylase activity. Other major interference is seen when lipoprotein in hyperlipemic samples with above-normal amylase activity reacts with the soluble oligosaccharide-triazinyl dye product of the Amylochrome assay to form a flocculent blue precipitate. The formation of this precipitate in the test, and its removal, diminish lactescence due to lipemia, an effect that cannot be matched by any manipulation of a serum blank procedure. Oligosaccharide-dye product is removed as a component of the precipitate.
Theophylline, dyphylline, caffeine, acetaminophen, salicylate, acetylsalicylate, procainamide, and N-acetylprocainamide determined in serum with a single liquid-chromatographic assay.
Authors: Ou C N , Frawley V L
Published: January 2020

We describe a single set of liquid-chromatographic conditions for assay of theophylline, dyphylline, caffeine, acetaminophen, salicylate, acetylsalicylate, procainamide, and N-acetylprocainamide in serum. The chromatographic system includes a Waters Associates mu-Bondapak C18 column and acetonitrile in 0.1 mol/L potassium phosphate buffer, pH 4.0 (9.75/90.25 by vol), as the mobile phase. Only 50 microL of serum is required, and drug concentrations as low as 0.5 mg/L can be detected. Absolute and relative analytical recoveries range from 95 to 101%. Day-to-day variation of the method is less than 6% for each drug. Linearity extends to 1 g/L for all drugs. Recycling of the mobile phase under pressure eliminates the need to prepare and de-gas solvents. The use of the single stationary and mobile phase provides a practical and economical approach to routine and urgent therapeutic drug monitoring.
Ascorbic acid in lymphocytes: cell preparation and liquid-chromatographic assay.
Authors: Lee W , Hamernyik P , Hutchinson M , Raisys V A , Labbé R F
Published: January 2020

Measurements of ascorbic acid concentration in leukocytes by "high-performance" liquid chromatography (HPLC) provides better nutritional assessment, leading to better management, particularly of presymptomatic and critically ill patients. This procedure includes a simple, reproducible cell-separation technique that requires no more than 2 mL of whole blood. Cell populations are separable with greater than 95% purity and greater than 99% viability. Ascorbic acid is assayed by HPLC. The vitamin can be reproducibly quantified in concentrations as low as 0.1 microgram/mL of cell extract. The chromatographic procedure is very rapid, analysis being completed within 15 min after specimen preparation. The assay is suitable also for urine and protein-free filtrates of plasma and of other biological materials. Reference intervals for plasma, mononuclear leukocytes, and polymorphonuclear leukocytes were established. A preliminary clinical evaluation revealed that hospital patients were at a greater risk of ascorbic acid deficiency than expected.
Mechanism of action of human pancreatic and salivary alpha-amylase on alpha-4-nitrophenyl maltoheptaoside substrate.
Authors: Hägele E O , Schaich E , Rauscher E , Lehmann P , Bürk H , Wahlefeld A W
Published: January 2020

We evaluated the enzymic mechanism by which alpha-4-nitrophenyl maltoheptaoside serves as a substrate for serum amylase (EC 3.2.1.1). Because polymeric substrates possess many potential sites of cleavage, the expression of enzymic activity as the number of micromoles of substrate transformed under defined conditions by an enzyme must be changed to "one microequivalent of group transformed." Therefore, we measured the activity of the isoenzymes of alpha-amylase with regard to suitable oligosaccharide substrates, which allowed us to express the catalytic activity in IUB units (U). By "high-performance" liquid chromatography we investigated the mechanism of human pancreatic and salivary alpha-amylase action, both alone and in combination with alpha-glucosidase (EC 3.2.1.20). On the basis of these results, we can describe exactly the entire reaction sequence and determine the stoichiometric coefficient of 4-nitrophenol within 0.02 mol/L (SD) produced under the assay conditions.
Specific spectrophotometry of ascorbic acid in serum or plasma by use of ascorbate oxidase.
Authors: Liu T Z , Chin N , Kiser M D , Bigler W N
Published: January 2020

We describe a specific enzymatic spectrophotometric method for ascorbic acid in serum or plasma. Samples are analyzed indirectly by measuring the absorbance at 593 nm of a reaction product, a complex of ferrous ion and 2,4,6-tris(2-pyridyl)-s-triazine (Fe2+-TPTZ). This product is formed by reduction of the corresponding ferric ion complex (Fe3+-TPTZ), which is nonspecifically reduced by various biological reducing agents under acidic conditions. Ascorbic acid is specifically quantified by pretreating one of a pair of replicate samples with ascorbate oxidase (EC 1.10.3.3), to oxidize the ascorbic acid, then reacting both samples with Fe3+-TPTZ and measuring the difference between the absorbances at 593 nm of the treated and untreated samples. This difference is linearly related to ascorbic acid concentrations from 10 to 100 mg/L. Ten repeat determinations of a serum pool with added ascorbic acid yielded a CV of 2.8% and a mean of 47.2 mg/L. The correlation (r) between the proposed method and the dinitrophenylhydrazine method was 0.93 for 32 samples analyzed by both methods. The present method is specific for ascorbic acid and requires no deproteinization.
Multivariate delta check method for detecting specimen mix-up.
Authors: Iizuka Y , Kume H , Kitamura M
Published: January 2020

Among laboratory mistakes, "specimen mix-up" is the most frequent and the most serious. According to the Clinical Chemistry Laboratory Error Report of Toranomon Hospital, specimen mix-up was often detected when there were many large discrepancies between the results of a test and the results of a previous test. We present here a checking method to detect specimen mix-up. The method, which we call the "multivariate delta check" method, is an extension of the "delta check" method first presented by Nosanchuk and Gottmann (Am. J. Clin. Pathol. 62:707, 1974). Clinical evaluation has demonstrated the effectiveness of the method.
Evaluation of some critical factors affecting determination of aluminum in blood, plasma, or serum by electrothermal atomic absorption spectroscopy.
Authors: Frech W , Cedergren A , Cederberg C , Vessman J
Published: January 2020

A digestion procedure involving nitric acid is described for determination of aluminum in blood, serum, and plasma by graphite-furnace atomic absorption spectroscopy. Contamination was not a severe problem if all operations were performed in a dust-free atmosphere. Conditions for such determination of aluminum in blood were optimum when the L'vov platform technique was used and hydrogen added to the inner gas flow of the furnace. We discuss the importance of adequate correction for nonspecific absorbance when this technique is used close to the detection limit. The blank value for the overall procedure was 1.0 (SD 0.59) micrograms/L (n = 22). We applied the method to frozen whole blood, plasma, and serum samples. For whole-blood samples from 11 different healthy subjects the mean value was as low as 1.6 (SD 1.29) micrograms of AI per liter (n = 22).
The biological role of enzyme attachment and immobilization.
Authors: Werner M , Garrett C , Chiu A , Klempner L
Published: January 2020

The state of enzymes in the living cell is considered: it is not clear whether some, if any, enzymes are naturally present in the "soluble" state. The evidence for enzyme binding to cellular constituents, and its effects on function and properties of enzyme and isoenzymes, is reviewed.
Enzyme immunoassay of thyroxin-binding globulin.
Authors: Miyai K , Ito M , Hata N
Published: January 2020

We describe a new double-antibody enzyme radioimmunoassay for thyroxin-binding globulin (TBG) in serum. A TBG-beta-D-galactosidase complex was prepared with m-maleimidobenzoyl N-hydroxysuccinimide ester. The mean analytical recovery of TBG added to serum was 99%, sample volume and TBG value were linearly related, and values for TBG determined by this method and those determined by radioimmunoassay correlated well (r = 0.98). Coefficients of variation averaged 7.6% within assay, 6.6% between assay. The measurable range of TBG in the serum was 3.3 to 52 mg/L, but higher TBG concentrations could be measured by diluting the test serum with TBG-free serum. Mean (and SD) serum TBG concentrations as determined by this method were as follows: for 20 normal subjects, 21.2 (3.7) mg/L; for 10 pregnant women, 50.1 (9.5 mg/L; and for 10 patients with TBG deficiency, not detectable.
Systematic error between erythrocyte protoporphyrin in proficiency test samples and patients' samples as measured with two hematofluorometers.
Authors: Balamut R , Doran D , Giridhar G , Mitchell D , Soule S
Published: January 2020

Hematofluorometers manufactured by two different companies (Aviv Biomedical and Environmental Science Associates) performed satisfactorily for protoporphyrin determinations with proficiency test samples but showed about a 30% low bias with actual clinical blood specimens.
Creatine kinase and creatine kinase B-subunit activity in serum in cases of suspected myocardial infarction.
Authors: Gerhardt W , Waldenström J , Hörder M , Hofvendahl S , Billström R , Ljungdahl R , Berning H , Bagger P
Published: January 2020

We evaluated a diagnostic strategy by studying 481 patients suspected of having had an acute myocardial infarction; the prevalence of infarction by independent criteria was 0.43. This strategy is based on the sequential application of: (a) clinical criteria; (b) total creatine kinase determinations in two serum samples drawn within 10 to 20 h of the onset of acute symptoms; and (c) creatine kinase B-subunit (S-CK B) determinations after immunoinhibition with antibodies to creatine kinase M-subunit in the reaction medium in all samples found to have increased total creatine kinase activity. Discrimination limits of 150 U/L total creatine kinase for women and 200 U/L for men gave a diagnostic sensitivity of 0.99. Activities less than these limits in samples identified 68% of the 274 non-infarct cases (posterior probability of a negative result of 0.99) within 20 h. Subsequent determination of S-CK B in 292 patients who were positive by the discrimination limits for total creatine kinase verified myocardial infarction in 99% of 207 cases for which S-CK B exceeded the discrimination limit of 12 U/L. The strategy excluded 98% of all non-infarct cases at a posterior probability of 0.99.
On individual reference intervals based on a longitudinal study of plasma proteins and lipids in healthy subjects, and their possible clinical application.
Authors: Raun N E , Møller B B , Back U , Gad I
Published: January 2020

In a longitudinal study, we determined interindividual and intra-individual variation in 20 plasma proteins and lipids and in other blood constituents by analysis of variance. Blood from 20 healthy subjects was sampled monthly for six months, a rigorous blood-sampling technique being applied. The mean proportion of interindividual variation differed for each blood constituent, ranging from 22 to 91% of the total variation. The possible clinical application of individual reference intervals of this homeostatic model was demonstrated by the fact that they were exceeded in individual cases of upper respiratory tract infection. Concordance between individual reference intervals in healthy controls and in patients--as exemplified in two chronic diseases, multiple sclerosis and chronic inactive pyelonephritis--suggests that the use of individual intervals in (chronic) disease is valid, even when derived from healthy persons. Additionally, sex- and age-related differences were significant for some constituents.
Radioimmunoassay for hepatitis B core antigen.
Authors: Sagnelli E , Pereira C , Triolo G , Vernace S , Paronetto F
Published: January 2020

Serum hepatitis B core antigen (HBcAg) is an important marker of hepatitis B virus replication. We describe an easy, sensitive radioimmunoassay for determination of HBcAg in detergent-treated serum pellets containing Dane particles. Components of a commercial kits for anti-core determination are used, and HBcAG is measured by competitive inhibition of binding of 125I-labeled antibodies to HBcAg with HBcAg-coated beads. We assayed of HBcAG in the sera of 49 patients with hepatitis B surface antigen (HBsAg)-positive chronic hepatitis, 50 patients with HBsAg-negative chronic hepatitis, and 30 healthy volunteers. HBcAg was detected in 41% of patients with HBsAg-positive chronic hepatitis but not in patients with HBsAg-negative chronic hepatitis. Hepatitis Be antigen (an antigen closely associated with the core of Dane particles) determined in the same sera by radioimmunoassay, was not detected in 50% of HBcAg-positive sera.
The cerebrospinal fluid immunoglobulin G index as a diagnostic aid in multiple sclerosis: a Bayesian approach.
Authors: Hische E A , van der Helm H J , van Walbeek H K
Published: January 2020

Having determined immunoglobulin G (IgG) and albumin concentrations in 1100 cerebrospinal fluid and serum samples, we calculated the IgG index. Likelihood ratios for multiple sclerosis were calculated by using a training set consisting of 100 patients with definite multiple sclerosis and one consisting of 97 patients suffering from diseases from which multiple sclerosis must be differentiated. Predictive values for multiple sclerosis, given different values for the IgG index, are given in a graphical representation of Bayes' theorem. We conclude that this approach increases the diagnostic usefulness of the IgG index for the diagnosis of multiple sclerosis.
Six methods for urinary protein compared.
Authors: McElderry L A , Tarbit I F , Cassells-Smith A J
Published: January 2020

Six assays for protein in urine were compared for linearity, ease of standardization, precision, comparability of assay values, technical ease of assay, and current cost. The assays investigated were three dye-binding techniques, a recent turbidimetric technique, the trichloroacetic acid--biuret reaction, and a tannic acid protein precipitation reaction with ferric chloride. All assays suffered from standardization problems, although the biuret method showed the best analytical recovery of albumin and gamma-globulin. The tannic acid/ferric chloride method is dependent on sample pH. The turbidimetric assay exhibited the greatest imprecision; i.e., CVs were 19.5% at a protein concentration of 0.13 g/L and 6.0% at a protein concentration of 1.3 g/L. On the basis of all the factors assessed, we conclude that the Pesce/Strande Ponceau-S and the Bio-Rad Coomassie Brilliant Blue dye-binding techniques offer certain advantages over the other assays studied.
Zinc in plasma, neutrophils, lymphocytes, and erythrocytes as determined by flameless atomic absorption spectrophotometry.
Authors: Whitehouse R C , Prasad A S , Rabbani P I , Cossack Z T
Published: January 2020

Zinc is determined in neutrophils and lymphocytes (isolated from whole blood on discontinuous gradients of Ficoll-Hypaque) and in microliter quantities of plasma and erythrocytes by flameless atomic absorption spectrophotometry with greater sensitivity than with conventional flame atomic absorption spectrophotometry. Before analysis, neutrophils and lymphocytes are digested with nitric acid and diluted with de-ionized water. Plasma and erythrocytes required no digestion, only dilution. Overall CVs were 4.0, 3.0, 5.0, and 4.6% for neutrophils, lymphocytes, erythrocytes, and plasma, respectively. Matrix effects were fully compensated for by use of standard solutions that simulated the sample matrix. Results for plasma and erythrocytes agreed with those obtained by the conventional technique.
Liquid-chromatographic determination of zomepirac in serum and plasma.
Authors: Welch C L , Annesley T M , Luthra H S , Moyer T P
Published: January 2020

We describe a determination of zomepirac concentration in plasma and serum by reversed-phase "high-performance" liquid chromatography. The assay requires 1.0 mL of sample and involves diethyl ether extraction of zomepirac from an acidified sample, followed by concentration and injection into a liquid chromatograph. The column effluent is monitored at 330 nm. Retention times of zomepirac and the internal standard (tolmetin) are 3.8 and 2.7 min, respectively. The lower limit of detection for zomepirac in serum or plasma is 0.05 mg/L. Within-day precision (CV) of analysis in plasma or serum with zomepirac added (0.1-10.0 mg/L) ranged from 1.4 to 6.7%; between-day CV varied from 1.4 to 7.5%. Analytical recovery of zomepirac (1.0 mg/L) from serum and plasma was 77.6 (SD 3.5)% and 80.4 (SD 5.2)%, respectively. Numerous commonly coadministered drugs did not interfere. The elimination half-life of the drug was 1.8 h, and the peak plasma concentration ranged from 1.1 to 2.4 mg/L. Peak and trough concentrations measured throughout five days of therapy imply no accumulation.
Radioimmunoassay for somatomedin C: comparison with radioreceptor assay in patients with growth-hormone disorders, hypothyroidism, and renal failure.
Authors: Baxter R C , Brown A S , Turtle J R
Published: January 2020

We raised an antiserum (Tr4) in rabbits against a basic somatomedin C-like peptide preparation. Using high-immunoreactivity somatomedin C tracer, we compared the performance of radioimmunoassays in which we used the Tr4 antiserum and a well-characterized somatomedin C antiserum distributed by the National Pituitary Agency (NPA) with that of the human placental-membrane somatomedin radioreceptor assay (RRA). In their cross reactivity toward various somatomedin-like and unrelated peptides, the two radioimmunoassay methods were almost identical, although NPA antiserum, with about fourfold higher titer than Tr4 antiserum, showed a slightly greater sensitivity for most peptides tested. Radioimmunoassay of acid-ethanol-extracted plasma samples from normal persons and acromegalic, hypopituitary, hypothyroid, and renal-failure patients revealed no analytical differences between the antisera (for 122 samples, r = 0.979 between methods). Somatomedin values for acromegalic and hypopituitary samples showed no overlap with normals. Values for hypothyroid and pre-dialysis renal-failure samples were significantly lower than normal. By comparison, the RRA showed greater cross reactivity toward some somatomedin-like peptides and gave significantly lower values than radioimmunoassay for acromegalic and hypothyroid plasma extracts, and significantly higher value for hypopituitary and renal-failure samples. We conclude that the radioimmunoassay methods clearly are of greater diagnostic value than RRA for clinical somatomedin measurement.
Uric acid determinations: reversed-phase liquid chromatography with ultraviolet detection compared with kinetic and equilibrium adaptations of the uricase method.
Authors: Ingebretsen O C , Borgen J , Farstad M
Published: January 2020

A reversed-phase liquid-chromatographic procedure is presented for quantitation or uric acid in human serum, with absorbance measured at 292 nm. The mobile phase was sodium acetate (35 mmol/L, pH 5.0)/acetonitrile (9/1 by vol). Complete precipitation of serum proteins was obtained by mixing serum (50-500 microL) with an equal volume of acetonitrile, and the precipitate was removed by centrifugation. Aliquots (20 microL) of the supernate were injected directly into the liquid chromatograph, which was adjusted so that the absorbance reading of the uric acid peak was as high as possible. Routinely, a full-scale deflection of 1.28 absorbance units was used. The within-run precision (CV) was 0.6% for a serum uric acid concentration of 227 mumol/L and day-to-day precision over a 15-day period was 0.8% for uric acid of 345 mumol/L. No interferences from related compounds were observed. We compared results by this method with those by kinetic (aca, Du Pont) and equilibrium adaptations (Ames kit; Nyco-test, Nyegaard; and Monotest, Boehringer Mannheim) of uricase methods. The method we report is simple, and can be used in a fully automatic liquid-chromatographic system.
Nephelometric measurement of ceruloplasmin with a centrifugal analyzer.
Authors: Pesce M A , Bodourian S H
Published: January 2020

We describe a rapid nephelometric assay for measurement of ceruloplasmin in serum with the Multistat centrifugal analyzer. In establishing the optimum conditions, the concentration of polyethylene glycol was critical. With a 30 g/L solution of polyethylene glycol, the calibrators and samples react at the same rate, while with a 60/L solution the calibrators react faster than the samples. The reaction rate was not affected by temperatures of 30 or 37 degrees C or pHs between 6.0 and 8.4. There was no interference from bilirubin at a concentration of 180 mg/L, hemoglobin at a concentration of 5000 mg/L, or lipemic serum. The standard curve extends from 50 to 1300 mg/L. Analytical recovery of ceruloplasmin added to four serum specimens averaged 97%. The within-run precision (n = 17) gave CVs of 5.4, 6.1, and 4.0% for samples containing ceruloplasmin at concentrations of 240, 360, and 650 mg/L. Ceruloplasmin concentrations measured by our procedure were compared with those obtained by nephelometric, radial immunodiffusion, and enzymic procedures; the correlation coefficients were 0.93, 0.88, and 0.86.
High-density lipoprotein cholesterol and phospholipids, and apoprotein A in serum of patients with liver disease.
Authors: Rubiés-Prat J , Masdeu S , Nubiola A R , Chacón P , Holguera C , Masana L
Published: January 2020

Concentrations of apoprotein A in whole serum, and cholesterol and phospholipids concentrations in the high-density lipoprotein fraction of serum were measured after the precipitation of low-density and very-low-density lipoproteins with sodium phosphotungstate-Mg2+ in 23 patients with liver cirrhosis, 19 patients with extrahepatic biliary obstruction, and 20 healthy control subjects. Patients with cirrhosis and cholestasis showed approximately one-half as much cholesterol and apoprotein A in the nonprecipitable high-density lipoprotein fraction as normal subjects did. High-density lipoprotein phospholipids concentrations in those patients were normal or slightly increased, however, which is about double what one would expect from the apoprotein A and cholesterol content.
Three radioligands compared for determining cytoplasmic estrogen-receptor content of human breast carcinomas.
Authors: Pieslor P C , Gibson R E , Eckelman W C , Oates K K , Cook B , Reba R C
Published: January 2020

We compared three radioligands for use in a cytoplasmic estrogen-receptor assay, using pooled cytosol from human breast adenocarcinomas. The estrogen receptor content was determined in vitro by a dextran-coated charcoal method involving a 4-h incubation with and without diethylstilbestrol. Tritiated moxestrol failed to come to equilibrium in 4 h, thereby preventing the use of conventional one-component Scatchard analysis. The use of 125I-labeled estradiol resulted in a higher estimate of estrogen-receptor concentration than that obtained with use of tritiated estradiol. This overestimation was not corrected by Scatchard, double-reciprocal, or Woolf plots, or by two different methods of data analysis: least squared and "robust." An underestimation of the specific activity of iodoestradiol with respect to that of tritiated estradiol and an unrecognized second component of nonreceptor binding could explain this disparity.
Demonstration of alpha 1-acid glycoprotein (orosomucoid) by double one-dimensional slab gel electrophoresis: evidence for intra- and interindividual variability of the microheterogeneity pattern in health and disease.
Authors: Altland K , Roeder T , Jakin H M , Zimmer H G , Neuhoff V
Published: January 2020

This double one-dimensional slab gel electrophoresis technique, in the sequence polyacrylamide gel electrophoresis followed by isoelectric focusing in polyacrylamide gels, permits the selective demonstration and comparison of the micro-heterogeneity pattern of alpha 1-acid glycoprotein (orosomucoid) in as many as 96 human plasma or serum samples on one gel. The electrophoretic analysis is performed on 8 microL of serum or plasma without prior purification. Several hundred samples can be analyzed by one investigator during a working day. Densitometric evaluation of the patterns revealed two new findings: 1) The microheterogeneity pattern can be described by a parameter that is independent of the concentration of orosomucoid in plasma: the center of density of the pattern, with the peak number as coordinate. 2) There is a considerable average shift of the center of density towards more basic components among the patterns obtained for samples from hospital patients. The results suggest that followup of the intra-individual variation of the orosomucoid pattern in health and disease might help in studying the still-uncertain function of this protein as well as the diseases affecting the pattern.
Two-dimensional analysis of human lymphocyte proteins. III. Preliminary report on a marker for the early detection and diagnosis of infectious mononucleosis.
Authors: Willard K E
Published: January 2020

Two-dimensional gel electrophoretic patterns of human peripheral blood leukocytes from 12 patients with infectious mononucleosis were prepared by use of the ISO-DALT system. Before the two-dimensional separation, the leukocytes were purified by Ficoll-Paque gradient centrifugation and labeled overnight with [35S]methionine. Quantitative increases in two proteins were detected in the patterns of infected leukocytes from the patients as compared with controls. Fluorescence-activated cell sorting of leukocytes from normal human peripheral blood before subsequent two-dimensional gel analysis revealed that the dramatic increase in one of these proteins (Inmono:2) could be due to shifts in the population ratios of lymphocytes, monocytes, and granulocytes (Willard et al., manuscript in preparation). In contrast, the appearance of the infected leukocytes of a second protein, Inmono:1, could not be accounted for by cell-population shifts. Increased amounts of these two proteins have been found in every patient studied who had clinically detectable infectious mononucleosis. In addition, a patient who displayed symptoms of infectious mononucleosis but who did not have a positive result in the MONOSPOT Test (Ortho) until three weeks after our analysis also demonstrated increased relative amounts of these proteins in his leukocyte pattern.
Development and evaluation of a new solid-phase direct immunoenzyme assay for prostatic acid phosphatase.
Authors: Gericke K , Kohse K P , Pfleiderer G , Flüchter S H , Bichler K H
Published: January 2020

In this assay we used polystyrene-tube-attached rabbit antibodies against prostatic acid phosphatase (PAP) that had been purified to homogeneity from human prostate. The amount of immunoreactive acid phosphatase was determined directly by its enzymic activity in the solid-phase-bound immune complex. The detection limit was 0.05 U/L (0.13 microgram/L), the CVs between 4.3 and 10.8%. Investigating the organ specificity of PAP, we found that some cross-reacting acid phosphatase activity could be so measured in human kidney, leukocytes, and platelets, all of which probably contribute to the circulating "prostatic" acid phosphatase that normally is present in serum. Diurnal and day-to-day variations in serum PAP activity were as much as 100% in healthy subjects. Individuals without prostatic diseases (n = 92) had values for serum PAP activity up to 0.36 U/L (0.94 microgram/L), in an age-independent distribution; patients with benign prostatic hyperplasia (n = 62) showed values up to 0.48 U/L (1.25 micrograms/L). With PAP activity of 0.38 U/L or 1.0 microgram/L (90th percentile of the prostatic group) as the upper limit of "normality," overall sensitivity (stages A-D) for detection of prostatic cancer in 33 essentially untreated patients was 65%. Examples for the followup of therapy of prostatic cancer by measurement of serum PAP with this assay are described.
Enzyme immunoassay for free thyroxin.
Authors: Weetall H H , Hertl W , Ward F B , Hersh L S
Published: January 2020

We describe a mathematical model for a single-tube enzyme immunoassay for free thyroxin (FT4), involving use of a thyroxin/horseradish peroxidase (EC 1.11.1.7) conjugate that does not interact with thyroxin-binding globulin. In the presence of serum two populations of unassociated, or free, immunologically active constituents are present: FT4 and the conjugate. The concentrations of the former are determined by the serum constituents and of the latter by the albumin concentration. When a small quantity of antibody is added, it reacts with the variable amount of FT4 and with the constant amount of the conjugate, thus giving a measure of the FT4. We constructed a mathematical model based on thermodynamic binding constants and adsorption data. The model gives satisfactory agreement with the experimental data under a variety of experimental conditions. Results for 19 patients' serum samples demonstrate the validity of the concept.
Partition affinity ligand assay (PALA) for quantitation of triiodothyronine in serum.
Authors: Mattiasson B , Eriksson H
Published: January 2020

Radioimmunoassay of triiodothyronine was performed with a homogeneous incubation system. Bound and free ligand were separated by partitioning in an aqueous two-phase system. The agreement between the results obtained with this technique and conventional heterogeneous radioimmunoassay was very good (r = 0.981).
Incidence of gamma-globulin banding in a healthy population by high-resolution electrophoresis.
Authors: Papadopoulos N M , Elin R J , Wilson D M
Published: January 2020

We report the incidence of electrophoretically homogeneous protein bands occurring in the gamma-globulin region in serum samples from 600 healthy adults, as determined with a high-resolution electrophoretic system. One or more electrophoretically homogeneous protein bands of various intensities were detected in the gamma-globulin region of 30 specimens when we used an improved agarose electrophoretic system, and in two specimens when we used a cellulose acetate electrophoretic system. Improvement of the agarose gel electrophoretic system thus enhanced its sensitivity in defining homogeneous protein bands in the gamma-globulin region. The incidence of these bands in a healthy population is approximately 5%.
Some extensions to the GELLAB two-dimensional electrophoretic gel analysis system.
Authors: Lemkin P F , Lipkin L E , Lester E P
Published: January 2020

Several important extensions to the GELLAB 2D electrophoresis gel analysis system are discussed, including concepts that lead to the generation of consistent gel maps for a particular cell line, as illustrated by some recent results for the P388D1 cell system, GELLAB is an interactive graphics computer system that facilitates (a) image accessioning, (b) spot-data extraction from the image with position and density quantitation, (c) pairing of corresponding spots between gels, and (d) spot analysis for a large number of corresponding spots (over 3000 per gel) for up to 128 gels. Multiple gels are accessioned into the system used to create a composite gel data base. These then may be partitioned into multiple classes of gels and searched for statistically significant interclass spot differences, which can be visualized in reference map images of selected spot sets as well as mosaic images of particular spots in all gels. In addition to the visual feedback that is available during the gel analysis, various statistical, numerical, and other displays may be generated in the CGELP interactive program of the GELLAB system.
Automated assay for alpha 1-antitrypsin with N-alpha-benzoyl-DL-arginine-p-nitroanilide as trypsin substrate and standardized with p-nitrophenyl-p'-guanidinobenzoate as titrant for trypsin active sites.
Authors: Eckfeldt J H , Light R T , Leiendecker-Foster C
Published: January 2020

alpha 1-Antitrypsin is the most abundant of several serum protease inhibitors. Its deficiency is associated with an increased incidence of emphysema in adults, jaundice in newborns, and childhood cirrhosis. We describe an automated functional assay for the Instrumentation Laboratory's Multistat III Microcentrifugal Analyzer with N-alpha-benzoyl-DL-arginine-p-nitroanilide as trypsin substrate. The assay is standardized in terms of moles of trypsin active sites inhibited per liter of serum, by use of a chromogenic titrant for trypsin active sites, p-nitrophenyl-p'-guanidinobenzoate. The method is rapid, precise, and independent of trypsin supplier, and results correlate well with those by a manual chromogenic and a nephelometric assay.
Galactosyltransferase variant in pleural effusion.
Authors: Kim Y D , Weber G F , Tomita J T , Hirata A A
Published: January 2020

In measuring total galactosyltransferase activity in the pleural effusions from patients with benign or malignant diseases, we found no significant difference between the two groups (p greater than 0.05). However, a small amount of a galactosyltransferase variant, GT(l), could be separated from other galactosyltransferase enzymes in malignant pleural effusions by anion-exchange chromatography (DEAE-cellulose) with a buffer of low ionic strength. Other galactosyltransferases were eluted from the column with buffer of higher ionic strength. Using a mini-column method, we detected GT(l) enzyme in 19 of 26 specimens fro cancer patients, as compared with eight of 25 specimens from patients with benign disorders. The appearance of GT(l) enzyme in pleural effusion may be a tumor-associated phenomenon.
Influence of triglyceride-rich lipoproteins on nephelometry of apolipoprotein A-I.
Authors: Funke H , Assmann G
Published: January 2020

Measurement of apolipoprotein A-I in native human sera by endpoint or rate nephelometry may give falsely high results for sera that have a high triglyceride content. Such erroneous determinations of apolipoprotein A-I can be avoided if one instead assays supernates of sera from which apolipoprotein B-containing particles have been precipitated with phosphotungstic acid and MgCl2. A high triglyceride concentration in serum does not impair the completeness of the precipitation of apolipoprotein B-containing lipoproteins or the analytical recovery of apolipoprotein A-I. In a prospective epidemiologic study, by using rate nephelometry we found that there were different mean concentrations for apolipoprotein A-I in supernates of sera from men (1.36 g/L) and women (1.49 g/L). Furthermore, the known risk factors for atherosclerosis showed different correlations with apolipoprotein A-I than with high-density lipoprotein cholesterol.
Diagnostic and prognostic value of laboratory tests assessed in a follow-up study of 200 patients with liver disease.
Authors: Skrede S , Solberg H E , Ritland S , Blomhoff J P , Schrumpf E , Elgjo K , Gjone E
Published: January 2020

Two hundred patients with liver disease were re-studied after six to eight years. The initial routine diagnosis (mainly based on morphological criteria) was confirmed in almost 80% of cases of chronic liver disease. In chronic active hepatitis, agreement was found in 86%. An alternative classification based on cluster analysis of clinical chemical results from the first admission was also to a great extent confirmed by the follow-up study. Discriminant analysis of clinical chemical data correctly allocated 94% of patients with alcoholic cirrhosis (who had low haptoglobin and albumin) into groups with different prognosis. Clinical chemical results differed between verified and non-verified cases of primary biliary cirrhosis. By retrospective examination , we found that 15 of 16 patients with this disease or chronic active hepatitis who were initially misclassified by biopsy findings could be correctly diagnosed by discriminant analysis of clinical chemical results.
Retention of carcinoembryonic antigen on Sephadex G-50 and acrylamide gel buffer-exchange columns.
Authors: Haagensen D E , Sawlivich W , Davis S , Zamcheck N
Published: January 2020

We compared the degree of retention of carcinoembryonic antigen on two types of buffer-exchange columns, Sephadex G-50 and acrylamide gel. Both types retained trace amounts of the antigen applied in the form of a perchloric acid extract, as measured by its release into plasma samples subsequently processed through the same columns, Cross contamination, resulting in values falsely high by greater than 1 microgram/L, was observed when columns were re-used after processing plasma samples with carcinoembryonic antigen concentrations greater than 700 micrograms/L.
Commercial radioimmunoassay kit for measurement of alpha-fetoprotein adapted for use with dried blood specimens from newborns.
Authors: Mizejewski G J , Bellisario R , Beblowski D W , Carter T P
Published: January 2020

We adapted a commercial RIA kit to measure alpha-fetoprotein (AFP) in 0.785-microliters portions of 60-microliters spots of dried blood from newborns. We evaluated sample elution, temperature and time stability, between- and within-assay variability, sensitivity, and use of liquid vs dried specimens of blood. Also, we present normal AFP concentrations for healthy neonates during the first postnatal week. Our procedure permits measurement of AFP concentrations both in maternal liquid plasma and in spots of dried blood from the infant with the same RIA kit reagents and standards. The sensitivity, precision, stability, and simplicity of this procedure makes more practical the routine measurement of AFP in dried blood specimens from newborns than measurement in liquid plasma or serum. Blood-sample collection by heel stick suffices for this simple, efficient, inexpensive determination of AFP concentration in the newborn.
Improved nonradioactive method for routine clinical analysis for long- and medium-chain stool lipids.
Authors: Bandi Z L , Kenny M
Published: January 2020

We describe a simple, practical method for routine clinical determination of long- and medium-chain stool lipids. Stool lipids were extracted into a hot mixture of benzene/ethanol/water (12/59/29, by vol), saponified in 30 min without formation of ethyl esters, and titrated in a clear, one-phase medium to a sharp color change. CVs for the titration were 2, 1, and 1% for 0.05, 0.25, and 0.5 mmol of fatty acids, respectively. Interference of stool short-chain acids other than fatty acids was not statistically significant. The precision of sampling of stool homogenate was improved by analysis of two aliquots, one from the top and one from the bottom of the suspension. This method of sampling is a practical alternative to the unpleasant homogenization with a blender or to the addition of large quantities of bile salts. The accuracy of the method may be increased, in special cases, by removing potential interferants.
Emulsions of perfluorinated compounds for use in quality control of blood gas analyses.
Authors: Rej R , Schröder J
Published: January 2020

We prepared emulsions of perfluorinated compounds and examined their utility as liquid matrixes for tonometry in quality control of blood pH and gas analyses. Emulsions of perfluorotributylamine and perfluorodecalin, prepared by sonication, consisted largely of particles not exceeding 0.2 micrometer in diameter. Unlike most aqueous solutions these materials were not easily contaminated by room air and can be reliably used for tonometry liquids. Results for pCO2 and pO2 agreed well with calculated values. Average day-to-day coefficients of variation for emulsions of perfluorotributylamine were 2.9% for pH (within the range 7.11-7.60), 4.4% for pCO2 (2.88-9.17 kPa), and 1.6% for pO2 (7.76-40.67 kPa).
Comparison of the effectiveness of four clinical chemical assays in classifying patients with chest pain.
Authors: Van Steirteghem A C , Zweig M H , Robertson E A , Bernard R M , Putzeys G A , Bieva C J
Published: January 2020

We compared the usefulness of four serum assays for classifying patients originally suspected of having an acute myocardial infarction. One of these is the long-used measurement of total creatine kinase (CK) activity. The other three are relatively new immunoassays: myoglobin by RIA, CK-BB by RIA, and CK-MB by immunoinhibition. When we evaluated test effectiveness with use of conventionally derived reference ranges, the results were misleading. However, by using receiver operating characteristic curves, we were able to effectively compare the four tests at all possible decision levels, rather than at only one. Multiple closely sequential serum specimens were obtained during the first four days after the onset of chest pain. Total CK, CK-MB, and CK-BB all behaved similarly, reaching peak diagnostic effectiveness at 18-20 h, when all three correctly classified 95% of the infarct patients, with a zero false-positive rate. However, total CK was more useful in identifying infarcts later in their courses than were the two CK isoenzyme tests. Myoglobin assay was most effective earlier in the course, at about 7 to 8 h. Our results indicate (a) that the tests for myoglobin and for CK or its isoenzymes are complementary and (b) that of the three CK tests, measurement of total CK activity provides the most information over the broadest segment of a patient's course.
Free-cortisol assay by immunoextraction: comparison with an equilibrium dialysis procedure.
Authors: Clerico A , Del Chicca M G , Zucchelli G , Bartolomei C , Riccioni N
Published: January 2020

We describe a new method for directly determining the apparent free cortisol concentration in plasma samples by use of an antibody-coated test-tube RIA. Buffer-diluted plasma or standard serum is added to antibody-coated test tubes, incubated at 4 degrees C for 4 h, and the solutions are aspirated. 125I-labeled cortisol is added to each tube and incubated for 3 h at 4 degrees C. Then the insides of the tubes are washed and their radioactivities counted. The standard curve is in terms of free cortisol, the standard serum solutions having been measured with an equilibrium dialysis procedure. Plasma samples (n = 155) from normal subjects and from various patients, measured with the new immunoextraction method and the equilibrium dialysis technique, gave results that correlated well (r = 0.847, p less than 0.001). Results by this direct RIA also correlate well with the clinical adrenocortical status of patients for whom data on total plasma cortisol may be misleading. This simple, easy RIA is suited to be the routine method for free cortisol in plasma.
Rate nephelometry of human IgE in serum.
Authors: Beck O E , Kaiser P E
Published: January 2020

We have developed an immunoassay method for the determination of human IgE concentration in serum by rate nephelometry. Using the Beckman Immunochemistry Analyzer, human IgE antisera, and a human IgE standard, we analyzed 150 serum samples from normal and allergic patients. We report these results and those from comparison studies involving PRIST and Phadebas kits (both from Pharmacia), and Enzygnost (Behringwerke) kits. We also discuss diagnosis of allergy patients and their classification according to their concentrations of IgE and IgG4.
Immunoturbidimetry of albumin and immunoglobulin G in urine.
Authors: Teppo A M
Published: January 2020

I describe a rapid, sensitive immunoturbidimetric assay for measuring urinary albumin and immunoglobulin G with use of an automated spectrophotometer. Diluted urine samples and polyethylene glycol in phosphate-buffered saline are pipetted into the cuvettes of the spectrophotometer. The initial absorbances of the samples are measured at 340 nm; antiserum to albumin or to immunoglobulin G is added to each tube, and after 2 min at 37 degrees C the absorbance of the mixtures is read at 340 nm. The initial blank absorbances of the samples are subtracted from the final absorbances automatically. The change in absorbance is linear with concentration in the range of 5-400 mg/L for albumin and 3-1000 mg/L for IgG. The lower limit of the determination is 5 mg/L for albumin, 3 mg/L for IgG. Linear correlations were observed between the concentrations of albumin and immunoglobulin G determined by this method (x) and those determined by radial immunodiffusion (y). The regression equation for albumin was y = 0.84x + 0.03 (r = 0.99, n = 87), and for IgG y = 0.94x + 0.02 (r = 0.98, n = 87).
Direct determination of lipoprotein cholesterol distribution with micro-scale affinity chromatography columns.
Authors: Bentzen C L , Acuff K J , Marechal B , Rosenthal M A , Volk M E
Published: January 2020

A quick and practical procedure based upon the principles of affinity chromatography has been developed and specifically adopted for the separation of serum lipoproteins into their respective alpha- and beta-lipoprotein fractions. The cholesterol, phospholipids, apoproteins, and triglycerides of these two lipoprotein fractions--the high-density lipoproteins (HDL) and lower density lipoproteins--can be directly measured independently after this separation. The sums of each fraction agree with total serum components when independently assayed. The affinity column is packed with heparin bound in high capacity to agarose. The beta-lipoproteins (low-density and very-low-density lipoproteins) and HDL-containing apolipoprotein E are absorbed to the column support; the alpha-lipoproteins (non-apolipoprotein E) pass through. The beta-lipoproteins are subsequently desorbed from the column support with saline. The direct assay of both the "protective" alpha-lipoprotein cholesterol (HDL cholesterol) and of the presumably atherogenic lower-density beta-lipoprotein cholesterol (LDL + VLDL cholesterol) permits calculation of a beta-: alpha-lipoprotein cholesterol ratio, which may better indicate a patient's risk of stroke or coronary heart disease than does the value for HDL cholesterol alone.