bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cobalamin-binding capacity of haptocorrin and transcobalamin: age-correlated reference intervals and values from patients.
Authors: Gimsing P , Nexø E 
Published: January 2020

Abstract
Unsaturated cobalamin-binding capacity in plasma (P-UBBC) is determined by use of a silica gel (QUSO G32) to separate haptocorrin (P-ApoHC) and transcobalamin (P-ApoTC). The method is sensitive and precise: detection limit 13 pmol/L, interassay coefficients of variation 3% for P-UBBC (mean = 1080 pmol/L), 4% for P-ApoTC (mean = 700 pmol/L) (n = 30). Values for P-UBBC, P-ApoHC, P-ApoTC, and P-TBBC (P-UBBC plus P-cobalamin) determined in a population study of 228 individuals, ages 21-87 years, did not differ by sex. These values increased with age, whereas the cobalamin saturation (P-cobalamin as percentage of P-TBBC) decreased with age. However, these changes were statistically significant but marginal and thus not clinically important. We therefore suggest using combined reference intervals (central 95 percentiles) for all age groups: 500-1200 pmol/L for P-UBBC, 90-275 pmol/L for P-ApoHC, 400-930 pmol/L for P-ApoTC, 850-1600 pmol/L for P-TBBC, and 20-50% for cobalamin saturation. Results for 277 inpatients show high P-ApoHC in myeloproliferative disorders or acute nonlymphatic leukemia, whereas P-ApoTC concentrations are high in some patients with lymphoproliferative disorders or autoimmune diseases.
Neopterin measured in serum and tissue culture supernates by a competitive enzyme-linked immunosorbant assay.
Authors: Barak M , Merzbach D , Gruener N 
Published: January 2020

Abstract
In this solid-phase competitive enzyme-linked immunosorbant assay for neopterin (a product of activated macrophages) in serum or supernates of cell cultures, we incubate antiserum to neopterin with standards or samples in the presence of solid-phase-bound conjugate of carrier-neopterin. Incubation with second antibody labeled with peroxidase then follows, before reaction with substrate. Analytical recovery, precision, and sensitivity of this method are similar to those of other immunoassays. The assay range is between 0.4 and 100 micrograms of neopterin per liter. Results obtained by this method compared with those from a conventional radioimmunoassay gave a correlation coefficient of 0.974.
Radioimmunoassay of beta-microseminoprotein, a prostatic-secreted protein present in sera of both men and women.
Authors: Abrahamsson P A , Andersson C , Björk T , Fernlund P , Lilja H , Murne A , Weiber H 
Published: January 2020

Abstract
We describe a simple radioimmunoassay of beta-microseminoprotein, one of the three most abundant secretory proteins of the prostate gland. The detection limit of the assay is 1 microgram/L, and its precision, expressed as the total coefficient of variation, is less than 10% for values between 10 and 150 micrograms/L. Using this assay, we found that beta-microseminoprotein immunoreactivity was present in sera from both sexes at about the same concentration. The protein detected had the same molecular size on gel chromatography as the protein isolated from seminal plasma, and dilution curves for the sera paralleled that for the pure protein. The findings suggest that beta-microseminoprotein is present in serum of healthy subjects of both sexes and that it originates in tissue other than the prostate gland. The range of the serum concentration was 0-10.6 micrograms/L (median 4.1) for 51 healthy adult women and 1.1-14.7 micrograms/L (median 6.2) for 35 healthy adult men not older than 40 years. In males with prostatic cancer the concentration in serum was highly variable and often greatly increased. The concentration of beta-microseminoprotein was correlated with that of creatinine in serum, suggesting that the protein is eliminated--at least partly--from the circulation by glomerular filtration. Little of the protein was present in the urine of women. In urine from men the concentration was high and variable, probably because of local contribution from the prostate gland to the urethral urine.
Clinical performance of the EMIT vancomycin assay.
Authors: Yeo K T , Traverse W , Horowitz G L 
Published: January 2020

Abstract
In evaluating the EMIT system for vancomycin used in the Cobas Bio centrifugal analyzer, we found two potential problems, each of which may have important clinical ramifications. First, precision, though acceptable in concentrations up to 30 mg/L, was marginal in the range above 30 mg/L. Second, when EMIT values were compared with those by fluorescent polarization immunoassay (TDx), we found a good correlation but a significant proportional bias: [EMIT] = (0.877)[TDx] + 0.435 mg/L (r = 0.971). The proportional bias was much more pronounced in specimens with high creatinine values than in specimens with normal values for creatinine. It remains to be determined which method is more nearly accurate. This imprecision and proportional bias in specimens with increased creatinines lead us to conclude that the EMIT vancomycin system should be used with caution.
Assay formats involving acridinium-ester-labeled DNA probes.
Authors: Arnold L J , Hammond P W , Wiese W A , Nelson N C 
Published: January 2020

Abstract
We describe the development of several hybridization assay formats involving acridinium-ester-labeled DNA probes. The simplest of these is a homogeneous assay procedure that requires only three steps to complete, including a 5-s detection step. Using this format, we have detected target sequences in the 10(-16) to 10(-17) mol range; when rRNA is the target, this translates to 3000 to 300 bacterial organisms. The entire assay can be carried out in less than 30 min. This is the first homogeneous DNA probe assay to be of practical use in the clinical laboratory, and it represents a major simplification of hybridization formats. We also demonstrate the use of this homogeneous assay format to discriminate single-base differences between two closely related target sequences and to detect DNA as well as RNA target molecules. By combining homogeneous hybrid discrimination with solid-phase separation, we have been able to decrease background readings from unhybridized probe to only a few parts per million. This enhances assay sensitivity about 10-fold, to a range of 10(-17) to 10(-18) mol of target. We are in the process of further improving the performance of these assays.
Rapid radioimmunoassay of circulating chromogranin A: in vitro stability, exploration of the neuroendocrine character of neoplasia, and assessment of the effects of organ failure.
Authors: O'Connor D T , Pandlan M R , Carlton E , Cervenka J H , Hslao R J 
Published: January 2020

Abstract
Chromogranin A is a useful probe of neuroendocrine neoplasia in humans. Here we optimize a rapid, sensitive radioimmunoassay modification for detecting chromogranin A in humans and other species. The site of chromogranin A circulation is the acellular plasma; platelets contain no chromogranin A immunoreactivity. The immunoreactivity in plasma is stable to repeated freezing and thawing, prolonged incubation at 37 degrees C, and lyophilization. Venipuncture alone resulted in modest (+ 12%, P less than 0.03) increase in chromogranin A in plasma. Several classic neuroendocrine neoplasia-pheochromocytoma, carcinoid tumor, neuroblastoma, and (vasoactive intestinal polypeptide)oma-produce markedly increased chromogranin A in plasma. By contrast, subjects with malignant melanoma, renal cell carcinoma, and thymoma all had normal values for chromogranin A. Hypersecretion of human choriogonadotropin beta subunit from both malignant (choriocarcinoma) and normal (placenta) syncytiotrophoblast cells was unaccompanied by an increase in chromogranin A, a dissociation compatible with the lack of granular storage and release of syncytiotrophoblastic peptide hormones. Both hepatic and renal failure resulted in increased chromogranin A in plasma, with renal failure leading to concentrations otherwise seen only in neuroendocrine neoplasia. These observations refine the diagnostic specificity of chromogranin A in plasma.
Aberrant lectin-binding activity of immunoglobulin G in serum from rheumatoid arthritis patients.
Authors: Parkkinen J 
Published: January 2020

Abstract
Structural studies of oligosaccharide chains of immunoglobulin G (IgG) in serum have revealed a specific galactosylation deficiency associated with rheumatoid arthritis (RA). Using a two-site lectin-immunofluorometric assay, I studied the interaction of IgG with immobilized lectins. Compared with control IgG, IgG purified from RA patients' sera bound up to 40-fold more strongly to immobilized Bandeiraea simplicifolia agglutinin II, a lectin that specifically binds agalacto forms of other glycoproteins. However, inhibition studies and treatment of IgG with glycosidase suggested that only a minor part of this binding was mediated by agalacto oligosaccharides of IgG. Furthermore, these IgG samples bound even more intensively to some other immobilized lectins, including Ricinus communis agglutinin (RCA). The binding to RCA was not inhibited by lactose, a hapten sugar of RCA, whereas other lectin species in solution effectively inhibited it. Compared with intact RA IgG, isolated F(ab')2 fragments displayed only low RCA-binding activity. These results indicate the existence of a carbohydrate-nondependent interaction between RA IgG and different plant lectins. With use of immobilized RCA, the lectin-immunofluorometric assay was rapid and reproducible for measuring the aberrant lectin-binding activity of IgG directly in diluted serum samples.
Biliary alkaline phosphatase measured by mini-column chromatography on DEAE-cellulose: application to detection of hepatobiliary diseases.
Authors: Yeh C T , Wei J S , Liaw Y F 
Published: January 2020

Abstract
Using chromatography on diethylaminoethyl (DEAE) cellulose, we measured biliary alkaline phosphatase (BALP; EC 3.1.3.1) activities in sera from 182 patients, most with hepatobiliary disorders but some with non-hepatobiliary diseases. Relative BALP activities were extremely low in otherwise healthy carriers of hepatitis B virus (mean: 5.4 U/L) and in patients with non-hepatobiliary diseases (mean: 5.3 U/L). Although BALP activities were detectable in some cases of liver cirrhosis and chronic hepatitis, these values were generally low (respective means: 12.6 and 12.0 U/L). High BALP activities were detected in patients with primary hepatocellular carcinoma, secondary metastatic liver tumors, and obstructive jaundice: mean values were 27.2, 37.2, and 73.6 U/L, respectively. There was no correlation between BALP activity and bilirubin concentration in patients with obstructive jaundice, nor between BALP activities in obstructive jaundice caused by stones and in those caused by extrahepatic tumor. Some patients with primary hepatocellular carcinoma had high BALP but low alpha-fetoprotein (AFP) values, some others the reverse. Based on AFP alone, the sensitivity for detecting hepatocellular carcinoma was 79%; adding BALP in parallel improved the sensitivity to 97%. We found minicolumn chromatography on DEAE-cellulose useful for determining BALP activity in hepatobiliary diseases.
Sources of imprecision in laboratories screening for congenital hypothyroidism: analysis of nine years of performance data.
Authors: Jewell S E , Slazyk W J , Smith S J , Hannon W H 
Published: January 2020

Abstract
We evaluated sources of imprecision in screening assays for congenital hypothyroidism performed between 1979 and 1987 by more than 45 laboratories participating in the national Neonatal Screening Standardization Program offered by the Centers for Disease Control. Reported concentrations were available from approximately 70,000 enriched dried-blood spot samples for thyroxin and thyrotropin, the primary and secondary screening assays, respectively. The most important sources of variation in assayed concentrations are within-laboratory imprecision and the methods or kits used. The importance of each of these sources depends on the analyte and its concentration. In most cases, the greatest source of measurement variation is attributable to within-laboratory imprecision (coefficient of variation 13% to 26%); however, kits are the largest source of variation at the lower concentrations of thyroxin. For both analytes, the greatest relative imprecision occurred at the low concentration, which was within the critical range of the cutoff values for detection of presumptive positive specimens. Imprecision in this range increases the risk of misclassifications. Minimizing within-laboratory imprecision and differences among kits seems to be the best way to improve overall efficiency of screening laboratories.
A micro-method for measuring total protein in cerebrospinal fluid by using benzethonium chloride in microtiter plate wells.
Authors: Luxton R W , Patel P , Keir G , Thompson E J 
Published: January 2020

Abstract
By using a benzethonium chloride concentration 12-fold that described originally (Clin Chem 1979;25:1317-9), we developed a reliable method suitable for routine measurement of total protein in cerebrospinal fluid. Only 10 microL of sample is required. Reactivity to immunoglobulin G (IgG) and to albumin (Alb) is similar, as is necessary for specimens that can have very varied IgG/Alb ratios. The assay, performed in a microtiter plate for ease of use, has a between-batch coefficient of variation of 3.4% for a protein concentration of 450 mg/L. This contrasts with a dye-binding technique with Ponceau S, for which the CV was 9% at the same concentration.
Monoclonal antibodies evaluated for use in a screening assay for conjugates of human serum albumin and pyridoxal 5'-phosphate.
Authors: Miller B B , Turner W E 
Published: January 2020

Abstract
This enzyme immunoassay (EIA) was developed to measure pyridoxal 5'-phosphate bound to albumin (PLP-HSA) in human serum. The monoclonal antibody titer was 1:2000 and a sequential saturation analysis curve, prepared with samples containing from 10 to 1000 nmol/L, showed a 50% inhibition of antibody at 50 nmol of the conjugate per liter. The lower limit of detection for PLP-HSA was 10 nmol/L, a sensitivity 1000-fold greater than that for any potential interferent. When serum samples gave negative results in the assay, we compared the antigenicity of the principal sites for PLP binding on HSA. It was apparent that the preferred physiological site was not antigenic; however, three additional sites for PLP binding on HSA elicited comparable antibody avidity. This EIA is potentially quite sensitive and specific for PLP-HSA, but considerable additional effort is required to convert serum PLP to an HSA-bound form detectable in the assay, which limits its application as a screening method.
Oligoclonal banding detected by urinary protein electrophoresis and immunofixation in two patients with the acquired immune deficiency syndrome and proteinuria.
Authors: Filomena C A 
Published: January 2020

Abstract
Monoclonal and oligoclonal banding has been observed in electrophoretograms of serum, cerebrospinal fluid, and urinary protein from patients infected with the human immunodeficiency virus (HIV). This is the first report of kappa oligoclonal banding in the protein electrophoretograms for urine but not for serum of two patients with the acquired immune deficiency syndrome (AIDS). Both patients had proteinuria, but only one had the nephrotic syndrome and renal failure. Serum oligoclonal banding in HIV-infected patients occurs much more frequently than in age-matched controls and may be detected before AIDS or lymphadenopathy syndrome evolves. The use of oligoclonal banding as a marker for HIV infection is currently under investigation. Urine as well as serum samples should be included in this research.
Antigens produced by recombinant DNA technology.
Authors: Fox J L , Klass M 
Published: January 2020

Abstract
Some of the greatest beneficiaries of the revolutionary advances in biotechnology over the past 15 years have been producers of diagnostic reagents, especially for the cloning and expression of antigens, primarily of viral origin. Recombinant DNA technology provides methods for producing antigens for diagnostic assays that are more highly purified, more specific, and safer to produce than viral culture and that are significantly less expensive to manufacture. Antigens so produced can be used for production of antibodies or antisera for competition assays, as reagents for mapping epitopes, as affinity-chromatography ligands for purification of antibodies or protein, and as research reagents. Their initial use in some hepatitis B assays may be primarily a cost-reduction application, but in other applications (e.g., HIV diagnostic tests) they present the first opportunity to commercially produce an otherwise very expensive antigen. Recombinant-DNA-produced antigens are also being used to develop safer vaccines, but not, however, without some consideration of the structural nature of immunodominant epitopes and the adequacy of the immune response.
Use of polymerase chain reaction for diagnosis of inherited disorders.
Authors: Boehm C D 
Published: January 2020

Abstract
The polymerase chain reaction (PCR) is a rapid method for generating a 10(6)- to 10(7)-fold increase in the number of copies of a discrete DNA or RNA sequence. The technique is being used for rapid prenatal diagnosis and carrier testing of several inherited disorders. After PCR, mutations producing single-gene disorders can be detected by several different methods, including endonuclease digestion and gel electrophoresis (applicable when a mutation affects an endonuclease recognition site), gel electrophoresis (used for detection of deletions), and hybridization to an oligonucleotide probe specific for a mutation. Less often, gene sequencing of a PCR product is used to rapidly identify a mutation. In addition, the PCR technique can be applied to polymorphism analysis to provide diagnosis by linkage analysis. In other areas, PCR is being used to detect and characterize microbial pathogens and to characterize mutations associated with carcinogenesis. The PCR method is useful in situations in which the amount of DNA sample is limited, such as in forensics and prenatal testing, or in which the quality of the DNA sample is poor.
Enzymatic amplification of RNA purified from crude cell lysate by reversible target capture.
Authors: Thompson J D , Decker S , Haines D , Collins R S , Feild M , Gillespie D 
Published: January 2020

Abstract
For increased clinical applications of nucleic acid probes to gene diagnosis, current procedures must be modified to become more amenable to the rapid processing of many samples with as few manipulations as possible. Here we summarize progress in the development of a strategy for performing molecular hybridization directly in lysate of biological samples dissolved in solutions containing the chaotropic agent, guanidine thiocyanate. Hybrids are purified by a process referred to as "reversible target capture," in which specific nucleic acid sequences are rapidly purified from crude lysate. We illustrate the use of this strategy to assay HIV-1 RNA and to rapidly purify HIV-1 RNA before enzymatic amplification by the polymerase chain reaction method.
S-100ao protein in blood and urine during open-heart surgery.
Authors: Usui A , Kato K , Abe T , Murase M , Tanaka M , Takeuchi E 
Published: January 2020

Abstract
Concentrations of S100a0 protein and CK-MB were measured by enzyme immunoassay in serial samples of arterial and coronary-sinus blood and urine taken from 26 patients who were undergoing mitral valve surgery. The mean concentration of arterial S100a0 in plasma was 0.32 (SD 0.28) ng/mL at the beginning of anesthesia, increased sharply after reperfusion, peaking [14.4 (SD 6.63) ng/mL] after 45 min of reperfusion, then decreased rapidly. The concentration of creatine kinase (CK) isoenzyme MB in arterial blood plasma was greatest 3 h after reperfusion [107 (SD 54.5) ng/mL]. S100a0 concentrations in urine increased dramatically after reperfusion [16,300 (SD 12,000) ng/h vs 44 (SD 32) ng/h], while CK-MB increased slightly [135 (SD 75) ng/h vs 19 (SD 12) ng/h]. These results suggest that S100a0 in cardiac muscle is released into the bloodstream during open-heart surgery and is discharged into the urine more rapidly than is CK-MB. Determination of S100a0 in plasma or urine thus may be useful for estimating damage to heart muscle during open-heart surgery.
Performance and diagnostic application of a two-site immunoradiometric assay for parathyrin in serum.
Authors: Ratcliffe W A , Heath D A , Ryan M , Jones S R 
Published: January 2020

Abstract
The "N-tact" immunoradiometric assay (IRMA) from INCSTAR for parathyrin (PTH) in serum involves a 125I-labeled affinity-purified antiserum to PTH 1-34 and an affinity-purified antiserum to PTH 39-84, the latter bound to a polystyrene bead. The mean detection limit, determined in six consecutive assays, was 4 ng/L. The within-batch CV was less than 7% in the range 15 to 2135 ng/L. The between-batch CV was 11.7% and 5.3% at 30 and 371 ng/L, respectively. Serum PTH in 14 proven cases of primary hyperparathyroidism was 49-808 (median 111) ng/L, undetectable (less than 5 ng/L) in 10 cases of primary hypoparathyroidism and in 10 cases of hypercalcemia associated with malignancy, compared with 7-39 ng/L in 45 normal subjects. PTH was 9 to 19 ng/L in four patients with familial benign hypercalcemia. In 39 patients with renal failure, apparent concentrations were 14 to 857 (median 133) ng/L, but sera from these patients pre-diluted with zero standard did not parallel dilutions of the standard, PTH 1-84. PTH concentrations were not significantly decreased in blood or serum kept at 20 degrees C for up to 6 h. After successful removal of a parathyroid adenoma, the mean half-time for disappearance of PTH in vivo in five hyperparathyroid patients was 3.3 min.
Reversed-phase HPLC separation of plasma norepinephrine, epinephrine, and dopamine, with three-electrode coulometric detection.
Authors: Musso N R , Vergassola C , Pende A , Lotti G 
Published: January 2020

Abstract
We present a method involving minor modifications of previous techniques, in which we use an ion-pair reversed-phase HPLC separation with three-electrode coulometry. Isocratic baseline separations can be obtained in 5 min. The sample preparation procedure, involving extraction with alumina at low temperature, allows good reproducibility (within-run and between-run CVs less than 10%) and improved sensitivity (less than 5 pg of each catecholamine per extract). This method allows approximately 70 low-cost plasma catecholamine analyses to be done in a working day.
Three direct spectrophotometric methods for determination of total bilirubin in neonatal and adult serum, adapted to the Technicon RA-1000 analyzer.
Authors: Harrison S P , Barlow I M 
Published: January 2020

Abstract
We adapted three bichromatic spectrophotometric methods for determining total bilirubin in serum, for use with the Technicon RA-1000 analyzer. The borate buffer (BOR) of Hertz et al. (Scand J Clin Invest 1974;33:215-30), the caffeine buffer (CAF) of Vink et al. (Clin Chem 1988;34:67-70), and the combined borate-caffeine buffer (B-C) of Franzini and Cattozzo (Clin Chem 1987;33:597-9) were compared. All methods required only 10 microL of serum, were precise (between-batch CVs less than 4.2%, analyte range 64-310 mumol/L), linear to 1000 mumol/L, and insensitive to interference from hemoglobin to 5 g/L. Lipemia, carotene, and methemalbumin interfered positively with each method but insignificantly unless in supranormal concentrations. Only the BOR method was sensitive to protein matrix effect. Neonates' results obtained with all three methods compared well with a Jendrassik-Gróf-based technique. However, samples from adults with cholestasis were overestimated, particularly by the CAF method, but the BOR and B-C methods would be suitable for "stat" bilirubin analysis in these samples.