bluuebunny/crossref_metadata_2025 huggingface dataset:
Anion-exchange chromatographic determination of bromide in serum.
Authors: Miller M E , Cappon C J
Published: January 2020

In this liquid-chromatographic method for the determination of bromide in human serum, an important and unique feature is pre-analysis ultrafiltration of the sample, which effectively removes proteins. The chromatographic system consists of an anion-exchange column (Whatman Partisil SAX 10-micron particles), an isocratic phosphate-buffered mobile phase, and ultraviolet detection at 195 nm. The absolute detection limit, 0.6 ng of bromide, makes this method the most sensitive assay for serum bromide yet reported. The day-to-day CV ranged from 1.6% to 4.9%. Analytical recovery of bromide added to serum samples ranged from 96.2% to 108.8%. Data on bromide in serum are presented for adults and newborns and for adults given bromide orally.
A new approach to photometry of glycated hemoglobin in human blood.
Authors: Deeg R , Schmitt U , Rollinger W , Ziegenhorn J
Published: January 2020

This new approach to measurement of glycated hemoglobin (Hb A1) is a three-step procedure involving (a) conversion of oxyhemoglobin into NO-hemoglobin by sodium dithionite and sodium nitrite in the presence of inositol hexaphosphate; (b) incubation with haptoglobin, which preferentially binds glycated hemoglobin; and (c) determination of the hemoglobin/haptoglobin complex by its peroxidase activity in acid buffer. The procedure is suitable for automated analysis with instruments that are capable of adding a starting reagent. We describe preliminary adaptations for the Abbott VP and Hitachi 705 analyzers and demonstrate the correlation of results with Hb A1 concentrations determined by ion-exchange chromatography.
"Nonspecific" Increases in Plasma Immunoreactive Calcitonin in Healthy Individuals: Discrimination from Medullary Thyroid Carcinoma by a New Extraction Technique
Authors: Body Jean-Jacques , Heath Hunter
Published: January 2020

Vol. 30

After pp. 513-514 of the April issue were proofed and released to the printer, the text was scrambled in the process of adjusting layout. We are reprinting the pages here as they should have appeared. The printer apologizes for any confusion and inconvenience this may have caused the readers and authors of this article.
Automated amidolytic method for determining heparin, a heparinoid, and a low-Mr heparin fragment, based on their anti-Xa activity.
Authors: ten Cate H , Lamping R J , Henny C P , Prins A , ten Cate J W
Published: January 2020

Using the chromogenic substrate S-2222, we have optimized and automated an amidolytic assay for heparin. The assay is based on the detection of anti-Xa activity generated by heparin in plasma. The method is reproducible (intra- and interassay CVs of 2.4 and 3.3%, respectively) and reliable in antithrombin III-deficient plasma. Results of this assay, obtained for plasma samples from patients and volunteers treated with heparin, correlate well (r = 0.899) with those of the test for activated partial thromboplastin time. Upon administration of a low-Mr heparinoid (Org 10172) and heparin fragment ( Kabi 2165), however, the activated partial thromboplastin time failed to detect anticoagulant activity, whereas the chromogenic heparin assay revealed anti-Xa activity. This automated amidolytic assay for heparin is therefore suitable not only for monitoring standard therapy with heparin but also for measuring the activity of recently developed heparin fractions.
A new assay for rheumatoid factor.
Authors: Giaever I , Keese C R , Rynes R I
Published: January 2020

This solid-phase immunoassay for detection of rheumatoid factor involves a specially prepared indium surface that renders protein layers visible and therefore does not require tagged protein. Using appropriate discriminatory values, we found agreement with results of a standard latex-fixation test in controls and patients with rheumatoid arthritis. About half of the patients with rheumatoid arthritis that were seronegative by this latex fixation test had positive tests by the present assay. Rheumatoid factor of both the IgM and IgA class may be easily assessed.
Indophenol method for acetaminophen in serum examined.
Authors: Novotny P E , Elser R C
Published: January 2020

We show that an indophenol-based colorimetric method for acetaminophen (Clin Toxicol 15: 67-73, 1979) has less than maximal sensitivity because of (a) incomplete hydrolysis, related to suboptimal acid concentration; (b) suboptimal hydrolysis time; and (c) possible deterioration of the ammonium hydroxide reagent after 2.5 months. We have modified the method by optimizing duration of hydrolysis and color development. Results by the method correlate linearly with acetaminophen concentrations to 250 mg/L (1.66 mmol/L). Moreover, the modified method is free from interference by compounds in serum from uremic patients.
Protein-enhanced fluorescein chemiluminescence used in an immunoassay for rubella antibody in serum.
Authors: Shapiro R , Chan J , Pierson A , Vaccaro K , Quick J
Published: January 2020

The chemiluminescence of fluorescein derivatives is greatly enhanced when they are conjugated to proteins. We exploited this property in devising a chemiluminescence immunoassay for rubella antibodies. In this sequential "sandwich"-type assay, tubes coated with rubella antigen are used for antibody separation and goat antibody to human IgG conjugated with fluorescein isothiocyanate is used for detection of bound rubella antibodies.
Effects of azotemia on results of the boronate-agarose affinity and ion-exchange methods for glycated hemoglobin.
Authors: Scott M G , Hoffmann J W , Meltzer V N , Siegfried B A , Chan K M
Published: January 2020

We evaluated the effect of azotemia on results for glycated hemoglobin as measured by a boronate-agarose affinity method and an ion-exchange chromatographic procedure with saline preincubation and found a good correlation. However, values for glycated hemoglobin in samples from nondiabetic patients with various degrees of azotemia were consistently higher with the ion-exchange column procedure (mean, 8.5%) than with the boronate affinity method (mean, 6.2%). The latter method may thus be preferred for monitoring glycated hemoglobin in diabetic patients with impaired renal function.
Liquid-chromatographic determination of indomethacin in blood from newborns with patent ductus arteriosus.
Authors: Ou C N , Frawley V L
Published: January 2020

This rapid, accurate "high-performance" liquid-chromatographic procedure is intended for measuring indomethacin in serum from neonates who are receiving indomethacin for symptomatic patent ductus arteriosus. Indomethacin and an internal standard (flufenamic acid) are extracted from serum or plasma with chloroform or diethyl ether at pH 5.0. For the chromatography we used a Waters' Radial Compression Separation System (Radial-NOVA PAK C18 reversed-phase column) and a mobile phase of methanol/sodium acetate buffer (10 mmol/L, pH 3.6), 70/30 by vol. The column effluent is monitored at 254 nm. Both indomethacin and flufenamic acid are eluted within 7 min. Indomethacin can be detected in concentrations as low as 50 micrograms/L, in 100-microL samples. Response varies linearly with indomethacin concentration to at least 2 mg/L. Analytical recovery is 75%; relative recovery is 100%. Precision is excellent. Using this method, we were able to improve the success rate for pharmacological management of symptomatic patent ductus arteriosus, especially in neonates with fast clearance rates for the drug.
Influences of specimen processing and storage conditions on results for plasma ammonia.
Authors: Howanitz J H , Howanitz P J , Skrodzki C A , Iwanski J A
Published: January 2020

Ammonia concentrations in plasma may increase because of contamination and deterioration of blood components during specimen handling and storage. Using replicate specimens from healthy volunteers, we studied influences of specimen processing and storage procedures on ammonia measurements made with a self-contained reagent system. Under some conditions, ammonia concentrations more than doubled. The use of nonhemolyzed plasma specimens and prompt centrifugation, separation of plasma, and ammonia determination apparently were important in avoiding such increases, the duration of contact between plasma and cells being the most important factor. Lower temperatures had minimal effect on whole-blood storage and centrifugation, but retarded increases in ammonia in stored plasma. We conclude that procedures for collection and storage of specimens for ammonia determinations should be standardized and strictly observed.
Hyperviscosity caused by hyaluronic acid in serum in a case of Wilms' tumor.
Authors: Wu A H , Parker O S , Ford L
Published: January 2020

We describe the case of a three-year-old girl with Wilms' tumor, whose serum showed at least a fivefold increase in relative viscosity although concentrations of albumin and immunoglobulins were normal. An unusual electrophoretogram of serum protein prompted further investigation. The increased viscosity was caused by the presence of high concentrations of hyaluronic acid, a glycosaminoglycan normally not detectable in serum.
Receptors, antibodies, and disease.
Authors: Blecher M
Published: January 2020

Abnormal antibody production is now recognized as the basis of specific endocrine and neurological diseases and their complications. Among the autoimmune diseases, the best understood from a mechanistic point of view are myasthenia gravis, Graves' disease, several variants of insulin resistance, and a variant of bronchial asthma. In each of these human disorders, the clinical symptoms can be traced to the actions of antireceptor antibodies produced by a deranged immune system. The autoantibodies produced in these diseases are functionally heterogeneous. They may produce the clinical symptoms of hormone or neurotransmitter insufficiency either by blocking the binding of these agents to target cell surface receptors or by accelerating the internalization and degradation of these receptors. In other cases, the autoantibodies may produce the clinical signs of hormone excess by mimicking the actions of the hormone, in an uncontrollable fashion. In some cases, functionally different types of autoantibodies will appear in the same patient at different stages of the disease. For all of these autoantibodies, of whatever function, assays for their presence in serum are available, in forms suitable for clinical chemists, as well as for researchers; these will be described in this review. In addition to the known anti-receptor autoimmune diseases, there are a large number of other autoimmune diseases for which there is fragmentary evidence that their clinical symptoms have an anti-receptor autoantibody etiology. Several examples of this group will be discussed, and assays suitable for establishing the presence of anti-receptor antibodies in the sera of such patients will be provided. The disorders to be considered are: type I diabetes mellitus, chronic atrophic gastritis, autoimmune Addison's disease, autoimmune hypoparathyroidism, type II pseudohypoparathyroidism, resistant ovary syndrome, connective tissue diseases, and the HLA-B8/DR3 antigen haplotype as a potential marker for autoimmune diseases of the anti-receptor type.
Theoretical aspects of one-point calibration: causes and effects of some potential errors, and their dependence on concentration.
Authors: Kemp G J
Published: January 2020

The potential errors of the one-point calibration technique are described mathematically. I examine the theoretical causes and effects of analytical errors in absorbance and of errors in determining calibration concentration, and discuss techniques for minimizing their impact. The dependence of these errors on the calibration concentration and on the size of the result is considered, and some conclusions are drawn about the choice of calibration concentration.
Familial dysalbuminemic hyperthyroxinemia: a study of four probands and the kindred of three.
Authors: Scottolini A G , Bhagavan N V , Oshiro T , Powers L
Published: January 2020

We investigated four probands, and the kindred of three, with familial dysalbuminemic hyperthyroxinemia, using the one- and two-step tests for free thyroxin and other thyroid-function tests. The results indicate that this is an autosomal dominant trait. The discovery of eight cases in our patient population, which represents about 4% of our hyperthyroxinemic patients (8/320), during eight months indicates that this aberration is more common than suspected. Its importance lies in the misinterpretation of test results and the consequent inappropriate treatment for thyrotoxicosis.
Multilayer-film analysis for urea nitrogen in blood, serum, or plasma.
Authors: Ohkubo A , Kamei S , Yamanaka M , Katsuyama H , Iwata Y , Sekikawa N
Published: January 2020

Two types of multilayer-film slides for measurement of urea nitrogen in blood are reported here: one for whole-blood samples, the other for plasma or serum. Urea nitrogen concentrations in plasma are determined almost immediately, without preparation of reagents or centrifugation of blood samples. Because the sample volume applied to the slide is not critical, reliable results are quickly obtained by the neophyte.
Intercomparison of seven radioimmunoassay kits and a fluorescence polarization immunoassay kit for digoxin.
Authors: Erickson K A , Green P J
Published: January 2020

Samples from 33 patients being treated with digoxin and three concentrations of control material were analyzed for this drug by use of seven radioimmunoassay (RIA) kits and an automated fluorescence polarization immunoassay (FPIA) system. CVs ranged from 2.4 to 6.4% for the FPIA system and from 4.6 to 7.4% for two RIA methods. In the analysis of between-method variability of RIA kits, CVs ranged from 6.1 to 33.2%. We compared each RIA kit with the other six RIA kits (I), as well as each RIA kit with the FPIA system (II). Correlation coefficients were greater than or equal to 0.96 in all cases. Slopes ranged from 0.82 to 1.20 for comparison I and from 0.86 to 1.01 for comparison II. For the FPIA system, analytical recovery of digoxin ranged from 94 to 104%. For the RIA methods we examined, analytical recoveries ranged from 113 to 135%. Analysis time is shorter and precision is greater for the FPIA system than for the RIA methods.
Free and total putrescine in cerebrospinal fluid quantified by reversed-phase liquid chromatography.
Authors: Heideman R L , Fickling K B , Walker L J
Published: January 2020

This is a simple, rapid, sensitive method for routine quantification of the polyamine putrescine (1,4-diaminobutane) in cerebrospinal fluid. Sample preparation involves protein precipitation, acid hydrolysis for 18 h (if total putrescine is to be measured), pre-column derivatization with o-phthalaldehyde, and extraction into acetonitrile. The derivative is separated and quantified by "high-performance" liquid chromatography on a reversed-phase C18 radial-compression column. A single chromatographic run takes less than 18 min. Putrescine concentrations as low as 50 nmol/L in cerebrospinal fluid can be detected.
The Ektachem clinical chemistry slide for simultaneous determination of unconjugated and sugar-conjugated bilirubin.
Authors: Wu T W , Dappen G M , Spayd R W , Sundberg M W , Powers D M
Published: January 2020

Using dual-wavelength spectrometry, we have refined the mordant-based bilirubin slide method (Clin Chem 28:2366-2372, 1982) to co-detect unconjugated bilirubin (Bu) and its sugar conjugates (Bc) in 10 microL of serum. The assay is based on three principles: (a) mono- and diconjugated bilirubins behave spectrally like one fraction (Bc) when bound to the mordant, (b) Bu and Bc are spectrally distinct, and (c) B delta (the bilirubin-albumin complex) is not measured in the film. With known bilirubin mixtures, results by the assay agree with those by nuclear magnetic resonance, by a Jendrassik-Gróf method for total bilirubin, and by a liquid-chromatographic procedure. With patients' sera, the slide correlates with a liquid-chromatography-augmented Jendrassik-Gróf method, according to the following typical regression statistics (in mumol/L): for Bu, slope = 0.992, r = 0.996, intercept = -0.376, Sy X x = 5.08; for Bc, slope = 0.970, r = 0.985, intercept = -0.735, Sy X x = 8.16. The method is precise (for Bu, CV = 5.2% at an average concentration of 16.4 mumol/L, and 4.1% at 66.7 mumol/L; for Bc, CV = 6.5% at 23.4 mumol/L, and 3.8% at 151.7 mumol/L for pools of patients' sera), is relatively interference free, and has potential for extension to further applications.
Development of a stable reference material for prostatic acid phosphatase.
Authors: Duncan P H , Van Etten R L , MacNeil M L , Shaw L M
Published: January 2020

We describe the development of a stable reference material for prostatic acid phosphatase, derived from human prostatic tissue and human seminal fluid. The enzyme was purified by an L-tartramic acid affinity-chromatography technique. Two-dimensional electrophoresis revealed essentially no contaminating proteins, and specific tests revealed no contaminating enzymes. The preparations, in a matrix containing 30 g of human serum albumin and 0.1 mol of sodium acetate per liter, pH 6.0, were studied with respect to stability of both catalytic activity and immunological identity. We conclude that the preparations from either source are satisfactorily stable, and that either is acceptable for use in preparing clinical reference materials. These materials will be used in developing a reference method.
Factors affecting measurement of urinary oxalate.
Authors: Mazzachi B C , Teubner J K , Ryall R L
Published: January 2020

Using a gas-chromatographic method, we examined the effects of phosphate concentration, added calcium chloride, and pH on precipitation of oxalate from urine. All three factors are important, but the pH of precipitation is particularly so, especially in the presence of even normal concentrations of ascorbic acid. At pH 8, increases in measured oxalate ranged from 20% at an ascorbic acid concentration of 1 mmol/L to more than 300% at 15 mmol/L. Ascorbic acid is rapidly converted to oxalate at alkaline pH. We also investigated the stability of both untreated and acidified urine containing ascorbic acid during storage for up to one month at -70, -20, and 4 degrees C, and room temperature. After one month, untreated collections were stable at -70 degrees C and acidified collections at -20 and -70 degrees C. We recommend conditions for assay and storage of urine specimens that are to be assayed for oxalate under which positive interference by ascorbic acid is minimized.
Improved determination of cytochrome b5 in human erythrocytes.
Authors: Kaftory A , Hegesh E
Published: January 2020

A sensitive, precise enzymic/spectrophotometric method for determining cytochrome b5 in small amounts of blood is described. Mean values for healthy individuals, ages 20 to 70 years, were 0.26 (SD 0.03) mumol per liter of erythrocytes or 0.87 (SD 0.14) nmol per gram of hemoglobin. We believe the assay is preferable to methods described hitherto, primarily because of its high sensitivity.
Influence of the hapten-fluorophore bridge on binding parameters in a fluoroimmunoassay for carbamazepine.
Authors: Sidki A M , Landon J , Rowell F
Published: January 2020

Raising antibodies to a hapten (drug or steroid) requires that it be coupled to a carrier protein through a bridge such that the hapten has maximum exposure with minimum changes in its configuration. In raising antisera in six sheep against carbamazepine (CBZ) coupled to bovine albumin, we found that some subpopulations of the antibodies recognized the bridge linking the drug to the carrier protein. To study the influence of the bridge on a fluoroimmunoassay for CBZ, we prepared four tracers by linking the carbamyl nitrogen of CBZ to fluorescein via four alkyl bridges of different lengths and structures. We calculated various binding parameters--including antibody affinity, binding capacity, and heterogeneity index--for each tracer and chose for the final fluoroimmunoassay the tracer that gave the best displacement with CBZ. We then optimized and validated the assay for direct measurement of CBZ in serum or plasma. The antibodies are coupled to magnetizable particles, which greatly facilitates separation and ensures removal of endogenous interferents.
Radioimmunoassay of aspartate aminotransferase isoenzymes in human serum.
Authors: Leung F Y , Niblock A E , Henderson A R
Published: January 2020

We describe the development of a sensitive, specific radioimmunoassay for the cytoplasmic and mitochondrial isoenzymes of human aspartate aminotransferase (L-aspartate:2-oxoglutarate aminotransferase; EC 2.6.1.1). Isoenzymes from human heart tissue were purified to homogeneity and used to raise high-titer antisera in rabbits. We partly purified the antisera by selective column chromatography. The Bolton-Hunter reagent was used to radioiodinate the isoenzymes. The assay requires 100 microL of serum, includes a solid-phase second-antibody separation, and can be completed in less than 3 h. There was no cross reactivity between the two isoenzymes. As little as 5 micrograms (50 pmol) of each aspartate aminotransferase can be measured per liter of serum.
Rapid colorimetry of zinc in seminal fluid.
Authors: Lampugnani L , Maccheroni M
Published: January 2020

This colorimetric method for determination of zinc in seminal liquid is based on the reaction between zinc and 4-(2-pyridylazo)resorcinol in a buffered solution at pH 9.5. It is very simple, fast (approximately equal to 10 min), and economical. It can be used to determine zinc in "whole" semen, seminal plasma, or isolated spermatozoa. We verified its accuracy for sample concentrations up to 0.4 g/L by comparison with a reference method based on atomic absorption spectroscopy of acidic wet-ashed samples. Calcium and magnesium do not interfere, even in concentrations exceeding the physiological values. Between-run precision at a normal concentration of 0.14 g/L is about +/- 7 mg/L; within-run precision at the same concentration is about +/- 2 mg/L.
Use of Alumina, SephadexGlO, and Ion-ExchangeColumnsto Purify Samplesfor Determination of Epinephrine,Norepinephrine,Dopamine, HomovanillicAcid, and 5-Hydroxyindoleacetic Acid in Urine
Authors: Westerink Ben N C , Bosker Fokko J , O'Hanlon James F
Published: January 2020

Vol. 28

p 1746: In line 10 of column one, "700 mL/L" refers to concentrated perchloric acid, which contains 700 g of the acid per liter.

Vol. 30

p 292, column two:

equation 1 should read:

[See equation in the PDF file]

The second part of equation 5 should read "sT = 1.66" (not "166"). Equation 6 should read sRA = [s2BR + s2PWR/Nk]1/2;and the equation at the bottom of the column should read sRA < [s2BR + s2PWR]1/2;. In the sentence just preceding section 3, change "s2WR" to "s2PWR."

p 299: "Corning," three lines from the bottom of column one, should read "Hoechst."

p 428: In Table 1, at the top of the third column: for "3.06" substitute "3.07" and for "3.94" substitute "4.12."

p 501: Column three, line 19: "...suggests that the thyroxin..." should read "...suggests that the immunogen..."

p 521: In this paper (e.g., Figure 3) the ratios reported are by weight. To express them on a molar basis, multiply by 1.10.

p 584: Units for calcium and phosphate should be "µmol/L" not "mmol/L."

p 758: In the equation near the bottom of column one, delete the bar over the x.

p 780: Four lines were omitted from the top of column 1: both comparing well with those of the Amersham analog-based assay for FT4 (7). The reference interval, 10-23 ng/L, clearly differentiated untreated hyper- and hypothyroid from euthyroid patients, only six of 74 results for euthyroid.
Effect of dialysis on interference by cefoxitin with determination of creatinine.
Authors: Kroll M H , Hagengruber C , Elin R J
Published: January 2020

Interference by cefoxitin with determination of creatinine is less with the Technicon SMAC than with other commercial analytical systems. The SMAC assay involves a single-point kinetic method with dialysis, whereas most other commercial methods are multipoint kinetic without dialysis. The apparent creatinine concentration measured for aqueous solutions of cefoxitin was 73 mmol of creatinine per mole of cefoxitin with the SMAC, 135 mmol/mol with a manual method. Furthermore, we determined for the SMAC that the average fraction of creatinine dialyzed was 0.128 and for cefoxitin, 0.064. Thus, the concentration of and interference by cefoxitin in the reaction mixture for SMAC are reduced by half (i.e., the apparent creatinine concentration for cefoxitin with the manual system multiplied by 0.5 is essentially that noted with the SMAC: 68 vs 73). Thus we conclude that the diminished interference be cefoxitin with determination of creatinine by SMAC is primarily ascribable to the dialysis step.
Bilirubin interference in a peroxidase-coupled procedure for creatinine eliminated by bilirubin oxidase.
Authors: Artiss J D , McEnroe R J , Zak B
Published: January 2020

A colorimetric peroxidase-coupled procedure for determination of creatinine in human serum and urine is described. A 30-s sample pre-treatment with bilirubin oxidase eliminates interference from endogenous bilirubin. The 4-aminoantipyrine-2-hydroxy-3,5-dichlorobenzenesulfonate chromogen system of this method is about fourfold more sensitive than current procedures that involve monitoring NAD(P)H and nearly fivefold more sensitive than the traditional picrate procedures. Incorporation of a sample blank eliminates positive interference from endogenous creatine. Results of the proposed procedure are somewhat lower than those of the common kinetic or equilibrium picrate techniques, as would be expected because of the effects of the well-known interferences in the latter methods.
Clinical evaluation of a fully automated chromogenic method for prothrombin time compared with a conventional coagulation method.
Authors: Tripodi A , Mannucci P M
Published: January 2020

The clinical usefulness of a chromogenic method for prothrombin time (PT) determination has been assessed in a wide range of clinical conditions, and it is compared with the conventional clotting method for PT. The new method appears to be as sensitive as the clotting PT to deficiencies of clotting factors of the extrinsic and common pathway, except for fibrinogen. Patients with proven liver disease were correctly diagnosed with a prevalence of abnormal results comparable to that by the clotting PT. Results by the two methods correlated highly (r = 0.96) for normal and congenitally deficient plasmas as well as for plasmas from patients on oral anticoagulant treatment (r = 0.95). High reproducibility (between-assay CV less than 3%) and easy adaptation to centrifugal analyzers make it a suitable candidate to replace the conventional method.
Zymogen activation: a new system for homogeneous ligand-binding assay.
Authors: Blake D A , Skarstedt M T , Shultz J L , Wilson D P
Published: January 2020

In this ligand-binding assay procedure, sensitivity is enhanced by successive generation of enzyme active sites via two zymogens from the blood-coagulation cascade: Factor X and prothrombin. A protease fraction from Russell's viper venom (RVV) acts upon Factor X, initiating a two-step cascade that culminates in generation of thrombin, the activity of which is monitored with a chromogenic substrate. In the model presented here, the analyte of interest, biotin, is covalently coupled to Factor X. In the presence of avidin, a biotin-binding protein, RVV cannot initiate cascade activity; however, the inhibition can be competitively overcome by addition of free biotin to the reaction mixture. In a complete system, the dose-response curve is linear from 20 to 100 nmol of biotin per liter. Such an assay offers improved sensitivity over many radioisotope-independent immunoassay methods, and may be applicable to a wide variety of analytes.
New separation method for monoclonal immunoradiometric assays and its application to assays for thyrotropin and human choriogonadotropin.
Authors: Rattle S J , Purnell D R , Williams P I , Siddle K , Forrest G C
Published: January 2020

We describe a novel separation procedure for immunoradiometric assays involving monoclonal antibodies in which both radiolabeled and capture antibodies are used in solution, the capture antibody being labeled with fluorescein isothiocyanate (FITC). Separation is achieved by incubation with anti-FITC antibodies on magnetic particles. This technique enhances reaction kinetics relative to those of assays in which a solid-phase capture antibody is used, thus allowing faster reaction times and more economic use of the monoclonal antibodies. The use of anti-FITC magnetic solid phase produces an assay having a highly specific separation method, minimal nonspecific binding, and high sensitivity. The method is illustrated by application to assays for thyrotropin and human choriogonadotropin.
Application of the MAST Immunodiagnostic System to the determination of allergen-specific IgE.
Authors: Miller S P , Marinkovich V A , Riege D H , Sell W J , Baker D L , Eldredge N T , Dyminski J W , Hale R G , Peisach J M , Burd J F
Published: January 2020

The MAST Immunodiagnostic Test System was developed to provide a comprehensive, simple means for the in vitro measurement of multiple antigens or antibodies. The first commercial application of the MAST system incorporates several novel features for cost-effective diagnosis of IgE-mediated allergy in a clinical laboratory or a physician's office. The basis of the MAST system is a unique analytical test chamber, which contains cellulose thread as the solid-phase matrix and allows multiple test results from a single assay. This test chamber incorporates both positive and negative controls and requires no volume-dependent pipetting steps. Immunographic exposure onto high-speed Polaroid instant film allows for quantifying results with an automatic recording infrared-transmittance densitometer. Test results are easily interpreted by using a patient test record provided with the system. The MAST system greatly simplifies testing for allergen-specific IgE, while retaining specificity and sensitivity. Currently, with the MAST system one can simultaneously measure picomoles of allergen-specific IgE in up to 35 different allergen classes. In addition to allergy testing, the MAST technology is applicable to other immunodiagnostic profiles.
Liquid chromatography in open tubes.
Authors: Maskarinec M P , Sepaniak M J , Balchunas A T , Vargo J D
Published: January 2020

Liquid chromatography in open tubes is evaluated for applicability to clinical analysis. The principal advantages of this technique include high separation power, reduced solvent consumption, and small sample volume requirements. Technology for the production of columns as small as 8 micron (i.d.) is described. Preliminary results are encouraging and, with further development in column and detector technology, the technique should find wide applicability in clinical analysis.
Novel shell/core particles for automated turbidimetric immunoassays.
Authors: Litchfield W J , Craig A R , Frey W A , Leflar C C , Looney C E , Luddy M A
Published: January 2020

Recent innovations in particle design have led to the development of highly sensitive and reproducible immunoassay methods for the Du Pont aca discrete clinical analyzer. Key advances include the synthesis and use of particles less than 1 micron in diameter with high refractive index cores surrounded by thin, chemically reactive shells. The cores are prepared by emulsion polymerization to a well-defined size that depends on the choice of monomer and the requirements for turbidimetric signal. Methods for measuring therapeutic drugs (e.g., theophylline) involve particles with polystyrene cores; other methods require cores with higher refractive indices such as polyvinylnaphthalene. The shells are critical for overall method performance because they bind covalently the immunochemicals of interest. Polyglycidyl methacrylate shells have been used effectively to attach antigens and haptens to the particle surface.
Affinity-column-mediated immunoenzymometric assays: influence of affinity-column ligand and valency of antibody-enzyme conjugates.
Authors: Freytag J W , Lau H P , Wadsley J J
Published: January 2020

We describe an affinity-column-mediated, enzyme-linked immunometric assay that is highly sensitive and adaptable to automation. Digoxin is the model test analyte. A comparison of digoxin with its analog, ouabain, for use as the immobilized ligand on the affinity column showed ouabain to be superior. We also report the effect of column elution rate. Antibody-enzyme conjugates prepared with the monovalent Fab'-fragment and the divalent F(ab')2-fragment coupled to beta-galactosidase are compared in terms of their overall assay performance. Although the monovalent Fab'--beta-galactosidase conjugate yields a more sensitive assay and dose-response curves that are linear over a wider range, the divalent F(ab')2--beta-galactosidase conjugate provides an assay with adequate sensitivity and extremely good precision, and is generally easier to synthesize reproducibly. This fully automated, rapid, and precise assay for digoxin is compatible with the Du Pont aca discrete clinical analyzer.
Elimination of "hook-effect" in two-site immunoradiometric assays by kinetic rate analysis.
Authors: Hoffman K L , Parsons G H , Allerdt L J , Brooks J M , Miles L E
Published: January 2020

Two-site or sandwich immunoradiometric assays (IRMAs) offer theoretical advantages over competitive immunoassay systems for sensitivity, precision, and rapid incubation. The practical realization of these advantages has been limited by the phenomenon of the "high-dose hook effect," such that high concentrations of an analyte give similar responses to those of much lower concentrations. We have developed a kinetic rate monitoring IRMA system for use with the Kineti-Count 48TM, an automated kinetic radioassay analyzer, which eliminates "hook-effect" interference, thereby permitting optimal assay design for increasing sensitivity and reducing incubation time. Practical illustration of these concepts is demonstrated by a 10-min, automated, quantitative assay we developed for human choriogonadotropin. The assay can detect as little as 1.2 int. units/L and kinetically screens for the hook effect. Kinetic rate analysis of the two-site IRMA and potentially of nonisotopic counterparts permits improvements in the speed and reliability of these immunoassays.
Anti-IgG binding test to assay circulating IgG-containing immune complexes from polyethylene glycol precipitates.
Authors: Levinson S S , Goldman J O , Feldkamp C S
Published: January 2020

We describe a simple approach for assaying immune complexes from serum by using anti-IgG as the indicator after a three-step extraction procedure with polyethylene glycol. Analysis of the data indicates that assays of such extracts for immune complexes by absorbance nephelometry, kinetic light scatter, and immunoradiometric techniques correlate well. For 116 samples, results by absorbance nephelometry correlated (r = 0.86) with those by the C1q-binding test. The present assay and the Raji cell test were more sensitive than the C1q-binding test (p less than 0.001) for detecting increased concentrations of immune complexes in 29 samples from patients with immune-complex-type diseases. The basic approach we describe may lend itself to broad applications for use with various immunoassay techniques.
Clinical effectiveness of the Du Pont aca measurement of creatine kinase MB in serum from patients in a coronary-care unit.
Authors: Leroux M L , Rabson J , Desjardins P R
Published: January 2020

We evaluated the clinical effectiveness of measuring creatine kinase (CK; EC 2.7.3.2) isoenzyme MB and lactate dehydrogenase (LD; EC 1.1.1.27) isoenzymes in diagnosis of acute myocardial infarction. We used an agarose electrophoresis method to measure CK and LD isoenzymes and the Du Pont aca column method to measure CK-MB. Serial blood specimens were drawn from 100 patients consecutively admitted to our Coronary Care Unit. Because of the low diagnostic specificity for CK-MB measurements by both agarose electrophoresis and the discrete-analysis method, as compared with reported values, we re-evaluated our isoenzyme data by using Receiver Operating Characteristic curves. Such analysis of the data established optimal decision levels of greater than or equal to 25 U/L and greater than or equal to 18 U/L plus greater than or equal to 6% of total CK for serum CK-MB measured by the agarose electrophoresis and the aca methods, respectively, and an optimal decision level of greater than or equal to 0.92 for the ratio of LD 1/2 measured after agarose electrophoresis. At these decision levels we obtained a sensitivity of 100%, 100%, and 95% and a specificity of 94%, 92%, and 90% for CK-MB (agarose electrophoresis), CK-MB (aca), and the LD 1/2 ratio, respectively.
International Legal Histories as Orders: An Afterword to Martti Koskenniemi’s Foreword
Authors: Iurlaro Francesca
Published: January 2020

In this article I address the question of what Martti Koskenniemi refers to in his EJIL Foreword as Hugo Grotius’ legal imagination – the type of values he was trying to convey and the strategies he meant to pursue while constructing his idea of an international legal order. As a matter of fact, focusing on such an apparently narrow aspect is not just relevant to those with a historical interest in Grotius. It also tells us something about the inveterate relationship between international law and historiographic practices. What I want to suggest here is that the history of international law is not just an a posteriori critical reflection on the international legal order – a subgenre for lovers of intellectual escapism in search of a distraction from the many problems of the contemporary world – but, rather, that one of the many successful projects of international law was (and still is) the ambition to order the world through histories.
The cutaneous microbiota of bats has in vitro antifungal activity against the white nose pathogen
Authors: Grisnik Matthew , Bowers Olivia , Moore Andrew J , Jones Benjamin F , Campbell Joshua R , Walker Donald M
Published: January 2020

Since its introduction into the USA, Pseudogymnoascus destructans (Pd), the fungal pathogen of white-nose syndrome, has killed millions of bats. Recently, bacteria capable of inhibiting the growth of Pd have been identified within bat microbial assemblages, leading to increased interest in elucidating bacterial assemblage-pathogen interactions. Our objectives were to determine if bat cutaneous bacteria have antifungal activity against Pd, and correlate differences in the bat cutaneous microbiota with the presence/absence of Pd. We hypothesized that the cutaneous microbiota of bats is enriched with antifungal bacteria, and that the skin assemblage will correlate with Pd status. To test this, we sampled bat microbiota, adjacent roost surfaces and soil from Pd positive caves to infer possible overlap of antifungal taxa, we tested these bacteria for bioactivity in vitro, and lastly compared bacterial assemblages using both amplicon and shotgun high-throughput DNA sequencing. Results suggest that the presence of Pd has an inconsistent influence on the bat cutaneous microbial assemblage across sites. Operational taxonomic units (OTUs) that corresponded with cultured antifungal bacteria were present within all sample types but were significantly more abundant on bat skin relative to the environment. Additionally, the microbial assemblage of Pd negative bats was found to have more OTUs that corresponded to antifungal taxa than positive bats, suggesting an interaction between the fungal pathogen and cutaneous microbial assemblage.
Implementation of Kenyan comprehensive school health program: improvement and association with students’ academic attainment
Authors: Akiyama Takeshi , Njenga Sammy M , Njomo Doris Wairimu , Takeuchi Rie , Kazama Haruki , Mutua Alex , Walema Barnett , Tomokawa Sachi , Estrada Crystal Amiel , Henzan Hanae , Asakura Takashi , Shimada Masaaki , Ichinose Yoshio , Kamiya Yasuhiko , Kaneko Satoshi , Kobayashi Jun
Published: January 2020

There is growing evidence supporting the effectiveness of a comprehensive school health program. However, implementation in developing countries is a challenge. Furthermore, the available information on the association between a comprehensive school health program and students’ academic attainment is limited. In Kenya, a project to verify the effects of a comprehensive school health program was carried out in Mbita sub-county, Homa Bay County from September 2012 to August 2017. This study aimed to clarify the improvement of school health during the project years and the association between school health and students’ academic attainment. Primary schools in Mbita sub-county were selected as study sites. We assessed 44 schools’ scores on a school health checklist developed from the Kenyan Comprehensive School Health Program, the students’ mean score on the Kenya Certificate of Primary Education (KCPE), and absenteeism during the project years (2013–16). The mean school health checklist score (n = 44 schools) was 135.6 in 2013, 169.9 in 2014, 158.2 in 2015 and 181.3 in 2016. The difference of the mean score between 2013 and 2016 was significant. In addition, correlation analysis showed a significant association between mean KCPE score in the project years and school health checklist score (Pearson’s coefficient was 0.43, p = 0.004). The results of this study suggest improvements of school health by the implementation of the Kenyan Comprehensive School Health Program and students’ academic attainment.
Do constitutional entrenchment clauses matter? Constitutional review of constitutional amendments in Europe
Authors: Hein Michael
Published: January 2020

Do constitutional entrenchment clauses matter? And if yes, how? This article examines these questions by analyzing a comprehensive collection of 154 decisions issued by European constitutional and supreme courts from 1945 up to 2016, on the constitutionality of constitutional amendments. The article shows that entrenchment clauses do matter: in the vast majority of decisions studied, the claimants and/or the courts referred to a constitutional entrenchment clause. About one-fourth of these cases resulted in the invalidation of a constitutional amendment, most of which were based on an “eternity clause,” that is, the most extreme type of entrenchment clauses. However, the article also demonstrates that most of these invalidations can be assessed as instances of democracy-adverse judicial activism. The article concludes, therefore, that entrenchment clauses cannot be considered an unambiguous instrument for the protection of democratic constitutionalism.
Women and participatory constitutionalism
Authors: Rubio-Marín Ruth
Published: January 2020

This article underscores the foundational exclusion of women from constitution-making as an expression of the ideology of separate and gendered spheres dominant at the birth of written constitutionalism. It traces the incorporation of women into constitution-making within a broader gender equality participatory turn taking place, since the late 1980s and especially 1990s, coinciding in time with the rise of popular constitutionalism more broadly speaking. By looking at a variety of examples drawn from multiple jurisdictions across the world, it explores the forms of participation of women in constitution-making both through their gradual (though yet insufficient) incorporation into official constitution-making bodies and institutions and, more importantly, through civil society mobilization. It claims that without taking into account the structural dimension of women’s traditional exclusion from the public sphere and constitution-making it is not possible to have an adequate comprehension of the strategies, challenges, meaning, and impact of women joining constitution-making, all of which I briefly describe.
The subjects of spatial statism: Reclaiming politics and law in international entanglement: Afterword to the Foreword by Ran Hirschl and Ayelet Shachar
Authors: Linden-Retek Paul
Published: January 2020

In their Foreword, Hirschl and Shachar challenge the supposed contemporary decline of state sovereignty and describe the enduring and expansive spatial reach of state power to counter threats to sovereign territorial control. This Afterword looks into the normative foundations of this account and its consequences for public international law and for international courts, in particular. “Spatial statism” exposes, I argue, a disjunction between the concepts of state sovereignty and popular sovereignty—and thus disrupts the normative expectation that those subject to the law are also its authors. It is this expectation that international judicial review must seek to restore. The attempt to do so is burdened by analytical and practical difficulties. But the project, I argue, is essential. In confronting the new “spaces” of international entanglement, judges must redeem the idea that citizens might yet reclaim those entanglements as a “common world,” not just a space in which they are brought together, unfreely, under the mantle of state coordination and coercion.
Evaluation of a New Automated Routine Measurement for Serum Adjusted Ionized Calcium (at pH 7.4) in Patients Suspected of Calcium Metabolic Disease
Authors: Kur Dår K , Hillig Thore , Hansen Steen I , Goharian Tina , Witte Majbritt L , Thode Jorgen
Published: January 2020

Background

Total calcium is a less accurate test in predicting ionized calcium (Ca2+) in patients suspected of calcium metabolic disease. Nevertheless, total calcium continues to be used as routine measurement instead of adjusted Ca2+ (at pH 7.4). In the current study we evaluate a new multichannel instrument, the ISE Module E1200 for adjusted Ca2+ (at pH 7.4), containing three different ion-selective electrode (ISE) units.

Methods

Serum from 1350 patients was compared to the ABL835 flex and KoneLab. Total calcium was also evaluated on the Dimension Vista 1500 system. Correlations between instruments were assessed by Deming regression and degree of agreement by Cohen’s kappa (κ).

Results

Analytical imprecisions for the three ISE units for adjusted Ca2+ (at pH 7.4) was between 0.36% and 2.52%, and for pH between 0.32% and 3.24%. Results were comparable for each ISE unit (r = 0.797–0.917; all P < 0.0001) and in high-throughput settings (r = 0.871; P < 0.0001). The degree of agreement between instruments was moderate to good (κ  =  0.52–0.77). In contrast, there was a very poor agreement (κ = −0.14) for total calcium with discrepancy in 53.4% of the samples.

Conclusions

The new ISE Module E1200 is comparable with the ABL835 flex and KoneLab 30i and therefore may be used for routine analysis of serum adjusted Ca2+ (at pH 7.4). The measured adjusted Ca2+ (at pH 7.4) was less comparable with very poor agreement to total calcium measured on the Dimension Vista 1500 system.