bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of Unbound Bilirubin in the Serum of Newborns
Authors: Jacobsen Jorgen , Wennberg Richard P 
Published: January 2020

Abstract
An enzymatic assay is described for non-albuminbound bilirubin in the serum of newborn infants. Unbound bilirubin is oxidized to colorless compounds by ethyl hydroperoxide in the presence of horseradish peroxidase (EC 1.11.1.7), while albumin-bound bilirubin is protected from oxidation. Because the equilibrium between albumin and bilirubin occurs rapidly, the oxidation step is rate limiting, and the initial oxidation velocity of total bilirubin is proportional to the unbound bilirubin concentration. By titrating serum with bilirubin in vitro, the association constant and binding capacity of high-affinity sites for albumin binding can be determined. Normal human serum albumin tightly binds 1 mole of bilirubin per mole of albumin (binding constant, 2-4 x 108 liter/mol). Although weaker secondary binding occurs, the unbound bilirubin fraction increases rapidly after the high-affinity binding sites are saturated. Compromised newborns may have a decreased apparent binding capacity and (or) binding affinity. The method can be used to assess the risk of a jaundiced infant for bilirubin encephalopathy.
Chemical and Clinical Evaluation of the Continuous-flow Analyzer "SMAC"
Authors: Schwartz Morton K , Bethune Victor G , Fleisher Martin , Pennacchia Gina , Menendez-Botet Celia J , Lehman Donald 
Published: January 2020

Abstract
"SMAC" (Sequential Multiple Analyzer plus Computer) is a high-speed computer-controlled multitest analyzer. A 20-channel prototype SMAC (glucose, urea nitrogen, creatinine, carbon dioxide content, total bilirubin, calcium, phosphorus, cholesterol, iron, uric acid, chloride, sodium, potassium, total protein, albumin, creatine kinase, alkaline phosphatase, lactate dehydrogenase, and aspartate and alanine aminotransferases) has been evaluated for: (a) method precision during within-day runs and on a day-to-day basis over a period of time; (b) method linearity over a range established on a chemical basis and related to clinical requirements, with use of both aqueous standards and protein matrix reference material; and (c) correlation of SMAC values with those obtained by the methods routinely in use in our department.
Simultaneous Determination of Methemoglobin and Total Hemoglobin by a Continuous-flow Method
Authors: Groff William A , Kaminskis Andris , Cucinell Samuel A 
Published: January 2020

Abstract
We describe a sensitive, accurate automated method for the simultaneous measurement of methemoglobin and total hemoglobin in blood. The method can be used for either continuous in vivo monitoring or intermittent sampling at a rate of 20/h. Standardization procedures are described, in which human blood treated with sodium nitrite is used. Repeatability of methemoglobin and total hemoglobin measurements, expressed as coefficient of variation in percent, are within ±4.1 and ±2.6%, respectively. Normal methemoglobin concentration’s in humans and dogs did not exceed 0.55 g/dl (3.3% of the total hemoglobin).
Optimized Determination of γ-Glutamyltransferase by Reaction-Rate Analysis
Authors: Rosalki Sidney B , Tarlow David 
Published: January 2020

Abstract
We describe a method for measuring γ-glutamyltransferase (EC 2.3.2.2) activity in serum, which can be used with automated enzyme analyzers (such as the LKB 8600 Reaction Rate Analyzer) that require enzyme reactions to be initiated with substrate. The method also permits optimal determination conditions to be obtained at 37 °C. The enzymatic reaction is commenced by adding γ-glutamyl-p-nitroanilide dissolved in dilute hydrochloric acid to samples pre-incubated with tris(hydroxymethyl)aminomethane—glycylglycine buffer. The p-nitroaniline liberated is continously monitored at 37 °C at 405 nm. The pH of the pre-incubation buffer is such that the optimal pH for the enzyme reaction results from addition of the acid substrate solution.
New Method for Direct Determination of "True" Creatinine
Authors: Yatzidis Hippocrates 
Published: January 2020

Abstract
Determination of serum creatinine by the Jaffé reaction may give erroneous results because of interfering noncreatinine chromogens. Studies of the Jaffé reaction in alkaline picrate media of various pH demonstrated that creatinine, proteins, and certain chromogens have characteristic properties as regards the appearance and intensity of the color reaction. Thus a method for determining "true" creatinine has been developed in which simple spectrophotometric measurements are made at 500 nm in two alkaline picrate reagents, buffered at pH 9.65 and 11.50. Results agree well with those obtained by the use of an ion-exchange method. The proposed method is easy and rapid and offers the advantages of increased specificity and direct analysis of serum and urine.
Radioimmunoassay for Serum Triiodothyronine: Evaluation of Simple Techniques to Control Interference from Binding Proteins
Authors: Fang Victor S , Refetoff Samuel 
Published: January 2020

Abstract
Simple techniques for controlling interference from binding proteins in serum, such as thyroxine-binding globulin, in radioimmunoassay for triiodothyronine (T3) have been evaluated for their efficacy, and their effect on assay sensitivity and on recovery of added T3. Ethanol precipitation of serum proteins decreased the assay sensitivity, nonspecific binding was increased, and recoveries of added T3 were inconsistent. Heat-inactivation of thyroxine-binding globulin or use of 8-anilino-1naphthalene sulfonic acid (ANS) to displace T3 from thyroxine-binding globulin produced comparable recovery rates. The heat-inactivation method slightly decreased the sensitivity of the assay and prolonged the procedure, whereas use of ANS is simple, and the assay sensitivity is maintained. When sera contain a high concentration of thyroxine-binding globulin, a fixed concentration of ANS (175 µg/100 µl of serum) might be too low to displace T3 from all its binding sites, but a concentration of ANS greater than 200 µg/100 µl of serum interferes with T3 quantitation by competitively binding to the antibodies. The cross-reactivity of thyroxine to T3-antibodies varies with the antiserum. Thyroxine-binding globulin appears to be the only protein in serum that competes with the antibody for T3 binding.
Increased β-N-Acetyl-Glucosaminidase Activity in Diabetes Mellitus
Authors: Belfiore Francesco , Lo Vecchio Luigi , Napoli Elena , Borzi Vito 
Published: January 2020

Abstract
In 45 diabetics the 24-h urinary excretion of β-N-acetylglucosaminidase (E.C. 3.2.1.30) was increased by 40% (P &lt; 0.05) compared to 35 control subjects. The enzyme excretion was correlated with glycemia (r = 0.58, P &lt; 0.001), being little changed in diabetics with blood glucose concentrations of less than 200 mg/dl, and markedly elevated (+ 123%, P &lt; 0.001) in those whose blood glucose was greater than 200 mg/dl. The rate of diuresis seemed to have no effect. These data indicate that the enhanced activity previously described in sera of diabetics for β-N-acetyl-glucosaminidase (as well as for other lysosomal enzymes) cannot be attributed to impairment of renal excretion, and support the hypothesis that in diabetes there is an "activation" of lysosomal enzymes in tissues that causes an increase in their activity in serum and, consequently, in urine.
"U" Protein and Migration Ratios in Paper Electrophoresis
Authors: Stern Joel R , Mais Roland F , Boggs Joseph D 
Published: January 2020

Abstract
Paper electrophoresis of serum from children with liver and kidney disease has led to recognition of a protein which migrates between the 2 and globulins. This protein has been observed by other workers, but because of confusion in nomenclature, a new designation, "U" protein, has been employed. The use of migration ratios in locating peaks of the 2 "U" protein, and globulin when these components resolve poorly has been discussed.
Characterization of "U" protein by employing the periodic acid-reduced fuchsin test for carbohydrate-protein complexes and Sudan black B for lipoprotein showed: (1)"U" protein varies in its content of protein-carbohydrate complex, and (2)"U" protein may be lipo-protein. Evidence based on benzidine tests and intentional hemolysis indicated that "U" protein was not an artifact resulting from accidental hemolysis, but a protein which is found in serum under certain physiological conditions.
Serum Copper and Iron on a Single Sample
Authors: Zak B , Ressler N 
Published: January 2020

Abstract
A procedure has been described for the quantitative determination of copper and iron in one serum sample. The sera are wet ashed to destroy organic material, leaving inorganic salts available in the residue for the subsequent spectrophotometric determination of iron as the ferrous-1,10-phenanthroline complex in the aqueous phase, and copper as the cuprous-2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline in an organic extract phase.
The Complexometric Titration of Micro and Ultramicro Quantities of Calcium in Blood Serum, Urine, and Inorganic Salt Solutions
Authors: Bachra Bernard N , Dauer Alan , Sobel Albert E 
Published: January 2020

Abstract
A method for the microdetermination and ultramicrodetermination of calcium in blood serum, urine, and inorganic salt solutions has been developed. Calcium was titrated with disodium ethylenediaminetetraacetate, and Cal-red as the indicator, using a Gilmont ultramicro-buret of 0.1-ml. capacity.
Amounts of 5 to 30 µg. of calcium per sample, of 0.05- to 1-ml. volumes, can be determined with a reproducibility of 1 to 2 per cent.
The difference between the values found for serum calcium with the Cal-red and the oxalate method had a standard deviation of ±3.32 per cent.
Serum magnesium can be determined as the difference of two simple titrations.
Phosphate levels up to 30 mg. per 100 ml. P did not interfere with the determination in serum, even when the calcium level was raised to about 20 mg. per 100 ml.
Up to products of 80(Ca X P, expressed in mg. per 100 ml.) there was no interference, in inorganic salt solutions. At higher products drift occurred, but the addition of some citrate to the solutions enabled the attainment of sharp end points at Ca X P products up to approximately 1000.
Urinary calcium was determined satisfactorily, without the occurrence of drift, if citrate was added to the solution.
Magnesium did not interfere appreciably, giving only 1 per cent higher readings at levels of 20 mg. per 100 ml. The interference of copper and iron was removed by the addition of sodium cyanide.
The Ferrohemoglobin Solubility Test
Authors: Goldberg C A J 
Published: January 2020

Abstract
1. Accuracy and precision of the ferrohemoglobin solubility test, a modification of the Itano procedure, have been discussed.
2. Excellent reproducibility was achieved using 10 buffers and 10 samples with a wide range of solubilities.
3. Ranges for normal adult hemoglobin, hemoglobins A and S, S in the presence of a small amount of fetal hemoglobin, S and C, and A and C are given, together with single values for hemoglobins A and D, A and I, A and L, and A and J.
Determination of Mercury in Urine
Authors: Nobel Sidney , Nobel Deana 
Published: January 2020

Abstract
A simple quantitative method for determination of mercury in urine has been described. The method is based on the reduction of mercury in urine to metallic mercury by a copper-hydrazine system. The metallic mercury is oxidized to mercuric ion by acid permanganate at room temperature. No special equipment or heat digestion is required. The mercury is estimated by a titrimetric dithizone technic. Industrial screening experience for mercurialism has been described.
Urinary Calculi
Authors: Nicholas Henry O , Leifeste H F 
Published: January 2020

Abstract
During the course of this investigation we have encountered two "fakes," both of which were represented by the patients to their respective physicians as having been "passed." They showed less than 2 per cent loss on ignition and proved to be calcium-iron-aluminum silicate rocks. We have also had about a dozen prostatic calculi which were analysed by the "ashing" method. This type of calculus consists of either a mixture of magnesium ammonium phosphate and calcium phosphate, or a mixture of calcium carbonate and calcium phosphate. The above-mentioned stones are, of course, not included in this picture. We hope that this survey and the simple method of analysis presented in these two articles will stimulate further work along this line in various parts of the country. The best similar survey we have seen is that of Leonard and Butt (1) on the types of calculi found in the Pensacola, Florida, area.
Residual Serum Thrombin Activity
Authors: Weiner Murray 
Published: January 2020

Abstract
A simple test for residual thrombin activity of serum is described. This test is believed to reflect the over-all antithrombin activity of the specimen.
These results are not altered by silicone vs. glass handling. The test is influenced by the presence or absence of contact with a fresh clot; by deficiencies in prothrombin or fibrinogen; by aging of plasma specimens and possibly by streptokinase administration in vivo, and by pancreatic disease.
The full significance of alteration in this test remains to be determined.
A Rapid Colorimetric Method for the Quantitative Determination of Copper Oxidase Activity (Ceruloplasmin)
Authors: Houchin O Boyd 
Published: January 2020

Abstract
A rapid procedure for determining quantitatively copper oxidase activity of plasma or serum is described. It is calibrated against determined amounts of ceruloplasmin and can be adapted to usual clinical laboratory equipment for the quantitative determination of ceruloplasmin.
DNA Microarray to Monitor the Expression of MAGE-A Genes
Authors: Zammatteo Nathalie , Lockman Laurence , Brasseur Francis , De Plaen Etienne , Lurquin Christophe , Lobert Pierre-Emmanuel , Hamels Sandrine , Boon Thierry , Remacle José 
Published: January 2020

Abstract
Background: The MAGE-A genes encode antigens that are of particular interest for antitumor immunotherapy because they are strictly tumor specific and are shared by many tumors. We developed a rapid method to identify the MAGE-A genes expressed in tumors.
Methods: A low-density DNA microarray was designed to discriminate between the 12 MAGE-A cDNAs amplified by PCR with only one pair of consensus primers. The assay involved reverse transcription of total RNA with oligo(dT) primer, followed by PCR amplification and hybridization on a microarray. Amplification in the presence of Biotin-16-dUTP allowed subsequent detection of the amplicons on the microarray carrying 12 capture probes, each being specific for a MAGE-A gene. Probe–amplicon hybrids were detected by a streptavidin-based method.
Results: PCR conditions were optimized for low detection limits and comparable amplification efficiencies among all MAGE-A nucleotide sequences. The microarray assay was validated with a panel of 32 samples, by comparison with well-established reverse transcription-PCR assays relying on amplification with primers specific for each gene. Virtually identical results were obtained with both methods, except for MAGE-A3 and MAGE-A5. Detection of MAGE-A5 was more sensitive with the microarray assay. Detection of MAGE-A3 was hampered by the presence of MAGE-A6, which is 98% identical: the MAGE-A3 capture probe cross-hybridized with MAGE-A6 amplicons because these sequences differed by only a single base.
Conclusions: This post-PCR microarray assay could be useful to evaluate MAGE expression in tumors before therapeutic vaccinations with MAGE-A gene products.
Use of Denaturing HPLC to Provide Efficient Detection of Mutations Causing Familial Hypercholesterolemia
Authors: Bodamer Olaf A , Bercovich Dan , Schlabach Michael , Ballantyne Christie , Zoch Danièle , Beaudet Arthur L 
Published: January 2020

AbstractBackground: Autosomal dominant familial hypercholesterolemia (FH) attributable to mutations in the LDL receptor (LDLR) gene is one of the most common genetic disorders associated with significant morbidity and mortality. Definitive diagnosis would help to initiate appropriate treatment to prevent premature cardiovascular disease. Currently, clinical diagnosis of FH is imprecise, and molecular diagnosis is labor-intensive and expensive because of the size of the LDLR gene and number of coding exons.Methods: We used PCR to amplify all exons, including exon/intron boundaries, and the promoter of the LDLR gene. Nine individuals from five families with typical findings for a clinical diagnosis of heterozygous FH, 2 heterozygous FH cell lines, and 50 control individuals were screened for mutations by denaturing HPLC (DHPLC) followed by direct sequencing of aberrantly migrating fragments.Results: Mutations that were previously reported to be disease causing were identified in eight of nine individuals with FH and both cell lines (V502M, C146X, E207X, C660X, C646Y, and delG197), but none were found in controls. The one individual with FH in whom no mutation was found had a previously unreported change in the 5′-untranslated region of unknown significance. In addition, we identified several previously reported polymorphism both in controls and individuals with FH.Conclusions: DHPLC can be used to detect mutations causing FH. On the basis of our current experience with DHPLC, this method combined with confirmatory DNA sequencing is likely to be sensitive and efficient.
In-Cell PCR Method for Specific Genotyping of Genomic DNA from One Individual in a Mixture of Cells from Two Individuals: A Model Study with Specific Relevance to Prenatal Diagnosis Based on Fetal Cells in Maternal Blood
Authors: Hviid T Vauvert 
Published: January 2020

Abstract
Background: During recent years, much attention has been paid to the possibility of using fetal cells circulating in the pregnant woman’s blood for prenatal diagnosis of genetic or chromosomal abnormalities. Although successes have been achieved in enrichment procedures for fetal cells from maternal blood samples, the use of such an approach for genotyping by molecular biology techniques in a more routine setting has been hampered by the large contamination of maternal nucleated blood cells in the cell isolates. Therefore, a new method based on in-cell PCR is described, which may overcome this problem.
Methods and Results: Mixtures of cells from two different individuals were fixed and permeabilized in suspension. After coamplification of a DNA sequence specific for one of the individuals and the DNA sequence to be genotyped, the two PCR products were linked together in the fixed cells positive for both DNA sequences by complementary primer tails and further amplification steps. In a model system of mixtures of male and female CD71-positive cells from umbilical cord blood attached to immunomagnetic particles, a Y-chromosome-specific sequence (TSPY) was linked to a polymorphic HLA-DPB1 sequence only in the male cells, leading to the correct HLA-DPB1 genotyping of the male by DNA sequencing of a nested, linked TSPY-HLA-DPB1 PCR product.
Conclusion: This approach might be usable on mixed cell populations of fetal and maternal cells obtained after conventional cell-sorting techniques on maternal peripheral vein blood.
Structural Diversity of Cancer-related and Non-Cancer-related Prostate-specific Antigen
Authors: Isono Takahiro , Tanaka Tsutomu , Kageyama Susumu , Yoshiki Tatsuhiro 
Published: January 2020

Abstract
Background: Heterogeneity among the various molecular forms of prostate-specific antigen (PSA) has not been well characterized, despite the critical importance of PSA in the detection of prostate cancer. The purpose of this study was to examine PSA heterogeneity in cancerous and noncancerous materials by extensive and systematic protein analysis.
Methods: A catalog of molecular forms of PSA was established with the PSA purified from seminal fluid. This catalog was used to analyze PSA heterogeneity in cancerous and noncancerous materials by immunoblotting with polyclonal antibodies.
Results: PSA from noncancerous materials showed a wider range of molecular mass, from 6000 to 28 000 Da. PSA from cancerous materials did not contain lower molecular mass forms.
Conclusions: The PSA protein catalog may be useful for the analysis of differences among PSA forms in men with and without prostate cancer and for analysis of antibodies used to detect PSA.
Apolipoprotein E in Apolipoprotein B (apo B)- and Non-apo B-containing Lipoproteins in 3523 Participants in the Stanislas Cohort: Biological Variation and Genotype-specific Reference Limits
Authors: Schiele Françoise , Vincent-Viry Monique , Starck Marjorie , Beaud Brigitte , Hennache Geneviève , Siest Gérard , Visvikis Sophie , Herbeth Bernard 
Published: January 2020

AbstractBackground: Apolipoprotein (apo) E is a component of two major classes of plasma lipoproteins, apo B- (apo E-LpB) and non-apo B-containing (apo E-Lp-non-B) lipoproteins. The factors that affect total apo E in particles [lipoprotein E (LpE), apo E-Lp-non-B, and apo E-LpB], are incompletely characterized.Methods: We studied the determinants of these lipoparticles in a sample population of presumably healthy individuals: 1784 children (age range, 8–18 years) and 1739 adults (age range, 19–50 years). Serum concentrations of LpE and apo E-Lp-non-B were measured by electroimmunoassays, and the concentration of apo E-LpB was calculated by a difference method.Results: Serum LpE and apo E-Lp-non-B were higher in females than in males. Their concentrations decreased with age until 20–25 years and then increased in men but not in women. apo E-LpB concentrations increased up to 20–25 years and were similar in both sexes. Thereafter, adult men had higher values than women. Individuals carrying the ε2 allele had higher mean apo E-Lp-non-B concentrations and lower apo E-LpB concentrations than did individuals carrying the ε3 allele. Individuals with the ε4 allele showed an inverse profile compared with those with the ε2 allele. Age, gender, the common apo E polymorphism, puberty, serum lipid concentrations, and alcohol consumption were significantly associated with total LpE, apo E-Lp-non-B, and apo E-LpB concentrations. Reference limits were established according to age, gender, and the common apo E polymorphism.Conclusions: Because measurements of LpE, apo E-Lp-non-B, and apo E-LpB concentrations may improve cardiovascular risk assessment, the proposed reference limits will aid interpretation of the results in clinical or therapeutic trials.
Stability of 11-Nor-Δ9-carboxy-tetrahydrocannabinol Glucuronide in Plasma and Urine Assessed by Liquid Chromatography-Tandem Mass Spectrometry
Authors: Skopp Gisela , Pötsch Lucia 
Published: January 2020

AbstractBackground: Unconjugated 11-nor-Δ9-carboxy-tetrahydrocannabinol (THCCOOH) in blood and urine has been proposed as a valuable marker, but the glucuronide (THCCOOglu) is present in considerably higher concentrations than the parent drug. Acyl glucuronides have been shown to be potentially reactive conjugates, which may affect the in vitro metabolite pattern.Methods: Extraction procedures and a liquid chromatography-tandem mass spectrometry assay were developed and validated to investigate the stability of THCCOOglu in urine and plasma. Plasma and urine samples with added THCCOOglu were stored at −20, 4, 20, and 40 °C up to 10 days.Results: The glucuronide was stable at −20 °C in both matrices, whereas THCCOOglu concentrations decreased at all other storage conditions. For a given storage time and temperature, the decrease in plasma was higher than that in urine. At 20 °C, a marked change in concentration could be observed within 2 days of storage. Degradation of THCCOOglu followed an apparent first-order process and led to the formation of THCCOOH. The sum of the molar concentrations of both analytes corresponded only to the initial THCCOOglu in plasma and urine samples stored at 4 °C.Conclusions: The in vitro degradation of THCCOOglu prevents clinical conclusions based on the metabolite pattern or the concentration of unconjugated THCCOOH in samples stored at ≥4 °C for prolonged periods.