bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of serum ferritin by a one-step immunoenzymoassay, and comparison of four liver-ferritin standards.
Authors: Revenant M C , Goudable J , Beaudonnet A , Mailliavin A , Pichot J , Monnet L 
Published: January 2020

Abstract
We describe a one step "sandwich"-type immunoenzymoassay for ferritin in human serum. The solid-phase consists of glutaraldehyde-treated polypropylene tubes coated with rabbit antibody to human ferritin. Liver ferritin is the standard. Peroxidase-conjugated antiserum to ferritin and a sensitive chromogen, o-phenylenediamine, are used. The assay requires 90 min. The standard curve is linear up to 400 micrograms of ferritin per liter of serum. Within- and between-run CVs are less than 6% for low, high, and medium concentrations and are about 13.0% at the decision level for iron deficiency. Results by a two-step "sandwich" procedure (New England Immunology Associates kit) correlated well, r = 0.98. We assessed four liver ferritin standards from different manufacturers with the described method. The mean absorbance for the 40 micrograms/L ferritin standard was 1.5 for that from Diagnostics Biochem and National Institute for Biological Standards and Controls, 1.0 for that from Dako, and 0.4 for that from Sigma. Consequently, to standardize results, all liver ferritin standards should be calibrated vs the National Institute for Biological Standards and Controls reference standard.
Placental alkaline phosphatase and cancer antigen 125 in sera of patients with benign and malignant diseases.
Authors: Eerdekens M W , Nouwen E J , Pollet D E , Briers T W , De Broe M E 
Published: January 2020

Abstract
Human placental alkaline phosphatase (hPLAP; EC 3.1.3.1), cancer antigen 125 (CA 125), and carcinoembryonic antigen (CEA) were determined in sera of patients with malignant and nonmalignant disorders. For CA 125 we used two different commercial assay systems, based on the same monoclonal antibody. hPLAP had the same sensitivity (20%) as CA 125 for detecting non-ovarian neoplasia, whereas that of CEA was 45%. For detecting ovarian cancer CA 125 (Cis kit) was slightly more sensitive (50%) than hPLAP (45%), much more than CEA (10%). hPLAP was increased in sera of 2% of patients with nonmalignant disorders, CA 125 in 23%, and CEA in 18%. hPLAP was increased in only one of 10 diabetic patients and two of 50 patients on chronic renal dialysis. CA 125 and CEA were respectively increased in 45% and 23% of all liver pathologies studied and in 12% and 17% of patients with renal insufficiency. The sensitivity of hPLAP for detecting ovarian cancer is slightly inferior to that of CA 125, but its specificity is much higher. We found the Abbott system for CA 125 to be more sensitive than the Cis system.
Direct spectrophotometry of magnesium in serum after reaction with hexokinase and glucose-6-phosphate dehydrogenase.
Authors: Tabata M , Kido T , Totani M , Murachi T 
Published: January 2020

Abstract
We describe a simple method for determining magnesium in serum by using hexokinase (EC 2.7.1.1) and glucose-6-phosphate dehydrogenase (EC 1.1.1.49). The method is based on determination of the reaction rate of hexokinase activated by Mg2+, which participates in the hexokinase reaction as the substrate in the form of a Mg X ATP2- complex. The reaction rate is determined from the change in absorbance at 340 nm as NADPH is produced by the action of glucose-6-phosphate dehydrogenase. This simple and rapid spectrophotometric method does not require expensive instrumentation, but results correlate satisfactorily with those obtained by atomic absorption spectroscopy. Thus, the present method gives a "true" value for magnesium in serum, a value appreciably lower than that obtained by an earlier colorimetric method, the Xylidyl Blue II method (Biochem Med 7: 208-217, 1973), which lacks specificity.
Studies on vitamin D binding protein in the nephrotic syndrome.
Authors: Colston K , Williams N J , Cleeve H J 
Published: January 2020

Abstract
We studied the properties of vitamin D binding protein in plasma and urine from nine patients with nephrotic syndrome. Samples were incubated with 25-[3H]hydroxyvitamin D3, after which we determined binding capacity and apparent dissociation constants. Binding capacity was markedly less in plasma from patients with nephrotic syndrome than that from normal subjects, but binding affinity was unchanged. Specific binding of 25-hydroxy[3H]vitamin D3 could be demonstrated in urine from all the nephrotic patients, and sucrose density-gradient analysis of these urines revealed a single binding peak with sedimentation characteristics similar to those of vitamin D binding protein in plasma.
Dry-reagent strips used for determination of theophylline in serum.
Authors: Rupchock P , Sommer R , Greenquist A , Tyhach R , Walter B , Zipp A 
Published: January 2020

Abstract
A reagent strip for quantifying theophylline in serum or plasma has been developed for use with the Apoenzyme Reactivation Immunoassay System (ARIS) with the Ames Seralyzer reflectance photometer. The test takes 80 s and involves comparison with a two-point calibration line, which can validly be stored in the instrument for two weeks. Results for theophylline in clinical serum samples correlate well (r greater than 0.98) with results by liquid chromatography, fluoroimmunoassay, and enzyme immunoassay procedures. The within-run CV for four concentrations of controls ranged from 3.5 to 6%; the between-run CVs ranged from 3 to 5%. This assay for use in therapeutic drug monitoring is convenient, rapid, and simple, and thus is appropriate for use in emergency rooms, physician's offices, and small laboratories.
Gamma-glutamyltransferase and its isoenzymes: progress and problems.
Authors: Nemesánszky E , Lott J A 
Published: January 2020

Abstract
Because of its sensitivity to disturbances of excretory liver function, gamma-glutamyltransferase (GGT; EC 2.3.2.2) assay has become one of the most important diagnostic tests for hepatobiliary disorders. However, its value in the differential diagnosis of liver diseases is limited. It is present in kidney, liver, pancreas, and intestine in electrophoretically distinct but not necessarily organ-specific forms. Much effort has been expended to relate diseases of these organs to isoenzyme findings in serum. Although the activities of GGT isoenzymes in disease differ from those in health, the existence of disease-specific patterns is controversial. Much is known about the biochemistry, structure, and immunochemistry of GGT, but more work is needed on methods, standardization of terminology, and correlation of isoenzyme findings with diseases. Further progress in the last area should improve the clinical applicability of the isoenzyme activities.
Fluorometric assay of alpha-L-iduronidase in serum for detection of affected and carrier animals in a canine model of mucopolysaccharidosis I.
Authors: Shull R M , Hastings N E 
Published: January 2020

Abstract
We investigated measuring serum alpha-L-iduronidase (EC 3.2.1.76) by a sensitive fluorometric assay in 28 members of a canine family with mucopolysaccharidosis I. If assayed on the day of collection, serum was an acceptable specimen for identifying affected, carrier, and normal dogs. The overall correlation (r) between iduronidase activity in serum and mononuclear leukocytes was 0.966. However, iduronidase was extremely labile in serum refrigerated or frozen for 48 h.
Stability of vitamin A in frozen sera.
Authors: Driskell W J , Lackey A D , Hewett J S , Bashor M M 
Published: January 2020

Abstract
We compared values for vitamin A measured in fresh sera with values obtained after storage at -20 degrees C for five to eight years. Loss of vitamin A from long-stored sera during the extraction step was eliminated by adding ascorbic acid to the extraction solvent, ethanol. Retinol-binding protein was also measured in the stored sera. Not only did vitamin A values remain stable during the years of storage, but also the correlation between concentrations of vitamin A and retinol-binding protein in the stored sera was typical of that observed with fresh sera.
Acid phosphatase and zinc in semen of subjects with no clinical evidence of prostatic disease.
Authors: Vaubourdolle M , Clavel J P , Cynober L , Piton A , Galli A 
Published: January 2020

Abstract
We evaluated the distribution of values for prostatic acid phosphatase (EC 3.1.3.2) activity and zinc concentration in semen of 80 men without clinical evidence of prostatic disease. Both substances have log normal distributions. Reference intervals were defined by parametric tests after logarithmic transformation of data and by nonparametric tests. There is a correlation between zinc concentration and prostatic acid phosphatase activity in semen.
Determination of vitamin E in microsamples of serum by liquid chromatography with electrochemical detection.
Authors: Chou P P , Jaynes P K , Bailey J L 
Published: January 2020

Abstract
In this procedure for determination of vitamin E by "high-performance" liquid chromatography with electrochemical detection, 25-microL serum specimens are deproteinized with ethanol. Vitamin E (alpha-tocopherol), its derivatives (beta- and gamma-tocopherols), and the internal standard (delta-tocopherol) are extracted into heptane and the extract is evaporated and the residue reconstituted with methanol before injection into the chromatograph. Within- and between-run CVs for an alpha-tocopherol concentration of 13.6 mg/L were 5.1% (n = 28) and 6.0% (n = 5), respectively. The standard curve is linear to 100 mg/L; the minimum concentration detectable is 0.1 mg/L. Analytical recovery ranged from 99.8% to 104.8%. In 36 specimens collected from apparently healthy subjects who were not taking vitamin supplements, alpha-tocopherol as determined by this method ranged from 4.3 to 9.7 mg/L, from 1.8 to 3.9 mg/L for beta- and gamma-tocopherols. Results by this method (y) and an HPLC-ultraviolet method (x) correlate reasonably (r = 0.81): y = 0.88x - 0.55 mg/L (n = 45). This procedure is adaptable to automated analysis, and the small sample requirement facilitates its applicability to neonates.
Immunoreactive phospholipase A2 in serum in acute pancreatitis and pancreatic cancer.
Authors: Nevalainen T J , Eskola J U , Aho A J , Havia V T , Lövgren T N , Näntö V 
Published: January 2020

Abstract
Immunoreactive phospholipase A2 (EC 3.1.1.4) was measured by a new sensitive time-resolved fluoroimmunoassay in the serum of 58 healthy subjects and 103 patients with acute pancreatitis. Patients with acute pancreatitis were grouped according to the etiology and clinical severity of the disease. The mean phospholipase A2 concentration in the reference (healthy) group was 5.5 (SD 1.9) micrograms/L. In acute pancreatitis the mean phospholipase A2 concentration was increased on the first day after hospital admission in all groups, and returned to normal somewhat more slowly than did serum amylase, especially in the patients with severe alcoholic pancreatitis. In this latter group the mean concentration of serum phospholipase A2 on the first day was 42.6 (SD 29.5) micrograms/L. In patients with pancreatic cancer, serum phospholipase A2 was 29.2 (SD 21.3) micrograms/L. The phospholipase A2 and amylase values were closely associated in all groups. The clinical sensitivities were 90.9% for severe alcoholic pancreatitis and 87.5% for pancreatic cancer. Immunochemical determination of phospholipase A2 in serum provides fast and specific detection of injury to pancreatic acinar cells. In addition to the early diagnosis of acute pancreatitis, follow-up determinations of phospholipase A2 seem to be useful in differentiating between mild and severe forms of pancreatitis.
Variability of plasma lipids and lipoproteins: the Jerusalem Lipid Research Clinic Study.
Authors: Friedlander Y , Kark J D , Stein Y 
Published: January 2020

Abstract
We examined the variability of lipid and lipoprotein concentrations in plasma from a population sample from the Jerusalem Lipid Research Clinic study. Coefficients of variation of about 8% for plasma cholesterol, 11% to 15% for low- and high-density-lipoprotein cholesterol, and about 30% for triglyceride were reported, both for 17-year-olds and adults examined twice, with a median period of two months between measurements. Stability was similar in a subsample of adults who had an additional measurement a median of 28 months later. Within-assay analytical variation (CV) was 1.9-2.0% for cholesterol, 1.5-2.3% for triglyceride, and 4.5% for high-density-lipoprotein cholesterol. Between-assay variation was 3-5% for cholesterol and triglyceride and 10% for high-density-lipoprotein cholesterol. The lower stability of the lipoprotein fractions of cholesterol than of total cholesterol emphasizes the need for repeated measurements of these fractions for more accurate characterization of subjects, especially those with extreme values, both for clinical use and for predicting outcome in follow-up studies.
Direct solid-phase radioimmunoassay for screening 17 alpha-hydroxyprogesterone in whole-blood samples from newborns.
Authors: Hofman L F , Klaniecki J E , Smith E K 
Published: January 2020

Abstract
We describe a direct, solid-phase RIA for 17 alpha-hydroxyprogesterone (17-OH-P) that we are using to screen neonates for congenital adrenal hyperplasia. Phosphate buffer containing danazol and anti-17-OH-P is placed in tubes coated with antibody to IgG. The tubes also contain standards, controls, or blood samples on filter paper discs 3 mm in diameter. 125I-labeled 17-OH-P is added to each tube. The mixture is vortex-mixed and incubated overnight. The fluid and disc are removed, the radioactivity remaining in the tubes is counted, and the amount of 17-OH-P per disc is calculated by using a log-logit transformation of the standard curve. Results compare favorably with those by two extraction assays. Inter- and intra-assay CVs were less than 11% and less than 9%, respectively. Sensitivity was 2 pg per assay tube. There is no significant cross reactivity with structurally related steroids at their physiological concentrations. Analytical recovery of added 17-OH-P averaged 104%. 17-OH-P in whole blood spotted on filter paper is stable for at least six months.
Measuring bile-salt concentrations lacks clinical value for detecting hepatic dysfunction in infants receiving parenteral nutrition.
Authors: Beckett G J , Glass E J , Callaghan M O , Elton R A , Hume R 
Published: January 2020

Abstract
Concentrations of conjugated cholate, chenodeoxycholate, direct bilirubin, and alanine aminotransferase (ALT, EC 2.6.1.2) were measured in plasma of 122 low-birthweight infants receiving parenteral nutrition. Eighteen (15%) of them developed hepatic dysfunction. We observed two distinct biochemical patterns in these infants. In the Type A pattern (12 infants), concentrations of direct-reading bilirubin and bile salts increased with no change in ALT activity. In the Type B pattern (six infants), increases in the concentrations of bile salt and direct bilirubin were followed by increases in ALT activity. Hepatic dysfunction persisted significantly longer in infants who developed the Type B pattern. The two patterns did not differ significantly in the times at which values for bile salts or direct bilirubin in plasma became abnormal or became normal at resolution, nor did maximal concentrations of bile salts in plasma differ significantly. Maximal concentrations of direct bilirubin were higher in the Type B infants. We conclude that, in such infants, measurement of bile-salt concentrations in plasma offers no advantages for detecting hepatic dysfunction over the more conventional measurement of direct bilirubin in plasma.
Immunochemical properties of immunoglobulin G conjugated with lactate dehydrogenase.
Authors: Sudo K , Maekawa M , Kanno T 
Published: January 2020

Abstract
Quantitative binding affinities of immunoglobulin G (IgG) for the five isoenzymes of lactate dehydrogenase (LD; EC 1.1.1.27) were determined for IgG isolated from three patients' sera that contained LD-IgG complexes. These three IgGs formed soluble complexes with four (LD 1, 2, 3, 5) of the five LD isoenzymes in two of the patients and in the third they bound with three (LD 2, 3, 4) of the five LD isoenzymes without inhibiting the enzyme activity or precipitating with the enzyme molecules. When rabbit antibody to human IgG was added to these sera, the complexes between the LD isoenzymes and the patients' isolated IgG were completely precipitated. The equilibrium constants for the respective isolated IgG complexes with LD-3 were 0.102, 2.58, and 7.49 X 10(8) L/mol. In these three cases, LD-3 evoked the strongest response from the prepared IgG, demonstrating that the site of antigen recognition of LD-linked IgG was not associated with the structure of individual H and M subunits.
Influence of autoantibodies to creatine kinase-BB on assays for MB isoenzyme.
Authors: Stein W , Bohner J 
Published: January 2020

Abstract
We describe the influence of autoantibodies that bind creatine kinase BB (CK-BB) on the methods for MB isoenzyme. If these autoantibodies are present in patients' sera, they cause the formation of macro CK type 1 (immunoglobulin-linked CK-BB). In some of these cases they can bind not only endogenous CK-BB but also CK-MB without significantly affecting enzyme activity. Although these antibodies show distinctly less affinity for CK-MB than for CK-BB, they nevertheless bind CK-MB in these particular sera, because their concentration exceeds that of CK-BB isoenzyme. If a person with such autoantibodies has an acute myocardial infarction, the immunoinhibition method for CK-MB, which does not discriminate between CK-MB and CK-BB, will recognize the increase and peak of CK-MB with time, although persistent macro CK activity will be superimposed on the typical isoenzyme pattern. However, isoenzyme electrophoresis and recently introduced immunoenzymometric assays for CK-MB in these cases may be less sensitive for detecting myocardial infarctions, because the typical increase in CK-MB activity may be identified later in the progression of symptoms, or even be missed.
Use of biotinylated probes for detecting sickle cell anemia.
Authors: Garbutt G J , Wilson J T , Schuster G S , Leary J J , Ward D C 
Published: January 2020

Abstract
Earlier, we reported that the 5' end of the normal beta-globin gene (beta) resides on a 1.14-kilobase DNA fragment, whereas the 5' end of the sickle cell gene (beta s) resides on a 1.34-kilobase fragment. In that blot hybridization analysis, we used genomic DNA digested with restricted endonuclease Mst II, and radioactive probes with short half-life. We demonstrate here that, if a biotinylated probe is used instead in a slightly modified procedure, sickle cell anemia can be quickly and directly detected if there is as much as 5 micrograms of total genomic DNA in the sample. This procedure obviates the special precautions necessary when radioactive materials are used.
Studies on the "labile-bound" glucose compartment in erythrocytes: studies on Psammomys obesus (sand rat) and preliminary studies on human erythrocytes.
Authors: Halperin M , Adler J H 
Published: January 2020

Abstract
Enzymatic (glucose oxidase) measurement of glucose concentration in the fluid compartment of Psammomys erythrocytes (Gfe) and of its concentration in the fluid compartment of blood plasma (Gfp) gives the ratio (mean +/- SD): Gfe/Gfp = 1.50 +/- 0.43 (n = 12, 23 degrees C). However, when we added 3H-labeled glucose (G*) in vitro to the whole blood, the ratio after 2 min was G*fe/G*fp = 0.90 (SD 0.11) and after 5 min G*fe/G*fp = 0.97 (SD 0.12). These calculations were based on previous determination of the fractional volumes of the fluid and non-fluid compartments in Psammomys blood. The results suggest that there is more than one compartment of measurable glucose in Psammomys erythrocytes. Glucose undergoes a fast free transfer between the plasma and the erythrocyte fluids, and a much slower transmission to another measurable compartment in the erythrocyte, where it is loosely bound to other molecules. This loosely bound glucose does not participate in the fast kinetic transmission across the erythrocyte membrane, but it is measurable by the glucose-oxidase-based method. Preliminary studies on human erythrocytes lead to similar conclusions.
A 2,4-dichlorophenyl diazonium-based method for total bilirubin without interference from indican in uremic sera.
Authors: McPhaul L , Kershaw M , Tilque D , Eckfeldt J H 
Published: January 2020

Abstract
Comparison of total bilirubin quantification by a 2,4-dichlorophenyl diazonium method (2,4-DCPD) with a Jendrassik-Grof type of method showed excellent correlation for randomly selected sera. However, sera from uremic patients on chronic hemodialysis showed a marked positive bias for the 2,4-DCPD result as compared with the Jendrassik-Grof result. The mean difference was 5.3 mg/L, and resulted in about 20% of the hemodialysis patients having bilirubin values greater than 13 mg/L, the upper limit of our reference range. Indican in uremic sera reportedly reacts with certain diazo reagents, so we investigated indican's reactivity in the above methods. In vitro addition of indican caused no interference in the Jendrassik-Grof method, but produced a significant positive interference in the 2,4-DCPD method, 1 mmol of indican per liter appearing as about 36 mg of total bilirubin per liter. Long reaction times with the 2,4-DCPD reagent accentuate the problem. By shortening the reaction time with the 2,4-DCPD reagent to 1.7 min, we find that the indican interference can be eliminated, without affecting quantification of total bilirubin in either normal or uremic sera.
Clinical Effectiveness of the Du Pont acaMeasurement of Creatine Cinase MB in Serum from Patients in a Coronary-Care Unit
Authors: Leroux Michael L , Rabson John , Desjardins Paul R E 
Published: January 2020

Abstract
Vol. 30
p 1553, Insert the symbol "○" in the sublegend to Fig. 1, third line, to read "...method: ○, activity..."
Vol. 31
p 572, middle of right column: delete the three repeated lines of type.
p 575, in "Table 1 (continued)," the first column heading hould read "Sample size, ND = ND·"
p 616, left column, first text paragraph: the second sentence should read, "This nonlinear protein binding explains the dependence of renal clearance of disopyramide on total disopyramide concentration in serum and the lack of dependence of renal clearance on the concentration of free disopyramide (5). Furthermore, the pharmacological response to this drug is better correlated with the concentration of the free drug in serum than with its total concentration (4, 6); we thus condude that both the free fraction and the total concentration should be measured when one is monitoring arrhythmic patients who are being treated with his drug."
p 617, left column: delete the two lines of text following the first paragraph of Results, and delete the three lines following the second paragraph.
p 640: Three lines are missing in the section on Ferritin standards, as follows: "Ferritin from human liver, 9.7 µg per bottle, i.e., 9.1 mg/L (National Institute for Biological Standards and Controls, Hampstead-Holly Hill, London, reference 80/602)."
p 641, left column, third line of text at bottom: "3988" should read "398.8" and "4140" should read "414.0."
p 647, middle column, preceding the 10th line from bottom, insert: "Using this method, we found the ... "
p 655, right column: the concluding paragraph (preceding the references) should read as follows: "Our results indicate that assay of serum SHBG is of value in the analysis of risk factors for mortality in post-menopausal women. Whether low SHBG concentration in these women primarily reflects androgen excess, estrogen deficiency, or other endocrine or metabolic changes remains a subject for further study, as does the relationship to adipose tissue distribution."