bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hereditary complete deficiency of lactate dehydrogenase H-subunit.
Authors: Joukyuu R , Mizuno S , Amakawa T , Tsukada T , Nishina T , Kitamura M 
Published: January 2020

Abstract
We report the second known case of a patient, a 45-year-old Japanese woman, with hereditary complete deficiency of lactate dehydrogenase (LDH; EC 1.1.1.27) H-subunit. Total LDH activity in her serum was abnormally low (35 U/L, normal reference interval 195-360). LDH activity in her erythrocytes was also low, but all the other glycolytic enzyme activities in her erythrocytes were within normal limits. Electrophoresis of her serum, erythrocytes, lymphocytes, thrombocytes, and saliva showed only one band, the LDH M4 isoenzyme. LDH activities in her saliva and lymphocytes exceeded the reference interval. Her erythrocytes contained fructose 1,6-diphosphate 26 mumol/L (normal range 4-13), dihydroxyacetone phosphate 75 mumol/L (normal range 8-22), glyceraldehyde 3-phosphate 57 mumol/L (normal range 4-14), and pyruvate 45 mumol/L (normal range 31-63). The family study of three generations showed that this deficiency was inherited in an autosomal recessive mode.
Properties of the beta 1- and beta 2-adrenergic receptor subtypes revealed by molecular cloning.
Authors: Frielle T , Caron M G , Lefkowitz R J 
Published: January 2020

Abstract
The beta 1- and beta 2-adrenergic receptor subtypes are biochemically and functionally similar, because both receptors mediate the catecholamine-dependent activation of adenylate cyclase through the GTP-binding protein, Gs. Pharmacologically, the two receptors can be distinguished on the basis of their relative affinities for the agonists epinephrine and norepinephrine as well as their affinities for several selective antagonists. The primary structures of the human beta 1- and beta 2-adrenergic receptors have recently been deduced from the cloning of their genes and (or) cDNAs, revealing high sequence homology and a membrane topography of seven putative transmembrane regions similar to that of rhodopsin. Chimeric beta 1/beta 2-adrenergic receptor cDNAs have been constructed by site-directed mutagenesis and the chimeric RNA transcripts expressed in Xenopus laevis oocytes. The pharmacological properties of the expressed chimeric receptor proteins were assessed by radioligand binding utilizing subtype-selective agonists and antagonists. Apparently, several of the putative transmembrane regions contribute significantly to the determination of subtype selectivity, presumably by formation of a ligand-binding pocket, with determinants for agonist and antagonist binding being distinguishable.
Reliability of the determination of whole-blood oxygen affinity by means of blood-gas analyzers and multi-wavelength oximeters.
Authors: Kwant G , Oeseburg B , Zijistra W G 
Published: January 2020

Abstract
Determination of the oxygen affinity of human whole blood with the help of blood-gas analyzers and multi-wavelength oximeters is compared with an accurate method for recording hemoglobin oxygen dissociation curves (Clin Chem 1982;28:1287-92). P50 (oxygen tension at half saturation; So2 = 50%) and Hill's n (delta log [So2/(1-So2)]/delta log Po2) were determined in blood of 24 healthy donors. Three slightly different procedures were used for determination of P50 on the basis of Po2, pH, Pco2, and So2 measured with each of four different blood-gas analyzer/oximeter combinations. These methods were not able to discriminate between high and low values for P50 within the normal reference interval, but never failed to detect the high oxygen affinity of blood stored for 12 days, reflected in low values of P50. The methods thus proved suitable for detecting clinically significant deviations in oxygen affinity such as occur in patients with, e.g., abnormal hemoglobins, anemias, or carbon monoxide poisoning. Determination of Hill's n by these methods did not produce useful results.
Immunoassay for estrogen receptor does not detect inactivated receptor.
Authors: Molnar L A , Dhirani N , Tran K , McBlain W A 
Published: January 2020

Abstract
Accurate quantification of estrogen receptor (ER) is essential for optimal clinical characterization of individual cases of breast cancer. If breast tumors are mishandled, the relatively labile ER protein may lose its steroid-binding capacity (become inactivated) and not be measurable by the routine steroid-binding assay. We tested whether the commercial enzyme immunoassay of Abbott Laboratories could quantify inactivated ER. Samples of powdered breast tumors from humans were exposed to various temperature and homogenization conditions known to inactivate ER, and any remaining ER was quantified by both the immunoassay and the steroid-binding assay. For all inactivation conditions tested, the two assay methods detected the same proportions of remaining ER. We conclude that the inactivation reaction for ER also alters one or both of the antigenic site(s) necessary for the immunoassay. Hence, for breast tumors mishandled to the extent of inactivating ER, the immunoassay offers no advantage over the more conventional steroid-binding assay for quantifying any remaining ER.
An automated procedure for measuring biotinidase activity in serum.
Authors: Weissbecker K A , Gruemer H D , Heard G S , Miller W G , Nance W E , Wolf B 
Published: January 2020

Abstract
In this automated procedure for quantifying biotinidase activity in human serum, a manual colorimetric method that measures conversion of the enzyme's artificial substrate N-biotinyl p-aminobenzoate was modified for use with a Technicon AutoAnalyzer II. The intra-run replicate precision (CV) was 2.1% and the day-to-day CV was 4.6% for quality-control sera. Results were linearly related to biotinidase activity in serum over the complete range of clinically relevant values, 0.2 to 11.0 U/L. Moreover, results of the automated assay were not significantly different from those of the manual assay. Because the automated procedure is faster and more precise, we recommend it for population-based studies and some screening studies.
A new commercial method for the enzymatic determination of creatinine in serum and urine evaluated: comparison with a kinetic Jaffé method and isotope dilution-mass spectrometry.
Authors: Lindbäck B , Bergman A 
Published: January 2020

Abstract
We evaluated a new, simple, enzymatic kinetic method from Wako Chemicals GmbH in comparison with a kinetic Jaffé method by using isotope dilution-mass spectrometry (ID-MS) as a reference method. An ID-MS-calibrated serum standard was used. Both the enzymatic and the Jaffé method correlated well with ID-MS, except for sera with high concentrations of bilirubin. Ethyl acetoacetate, acetone, and glucose in serum interfered somewhat with the Jaffé method but not with the enzymatic method. We conclude that the present enzymatic method has merit as compared with a Jaffé method for routine work, but is more expensive.
Partial characterization of an abnormal lactate dehydrogenase isoenzyme, LDH-1ex, in serum from a patient with hepatocellular carcinoma.
Authors: Kalpaxis D L , Giannoulaki E E 
Published: January 2020

Abstract
Serum from a patient with hepatocellular carcinoma contained an abnormal isoenzyme of lactate dehydrogenase (LDH; EC 1.1.1.27), LDH-1ex, that on electrophoresis on 10-g/L agarose gel migrated anodally to the LDH-1 band. This isoenzyme was partly purified by ultrafiltration and preparative electrophoresis. Gel chromatography and sodium dodecyl sulfate/polyacrylamide gel electrophoresis studies of the resulting LDH-1ex preparation suggested that this isoenzyme is probably a tetramer made up of four single polypeptide chains (monomers), each having a molecular mass of about 32,000 Da. LDH-1ex was heat stable and reacted more readily with 2-hydroxybutyrate than did the slower migrating LDH-4 and LDH-5 isoenzymes. LDH-1ex showed no activity when lactate was omitted from the substrate solution or replaced by ethanol.
Activities of dipeptidyl peptidase II and dipeptidyl peptidase IV in synovial fluid from patients with rheumatoid arthritis and osteoarthritis.
Authors: Gotoh H , Hagihara M , Nagatsu T , Iwata H , Miura T 
Published: January 2020

Abstract
We examined the activities of peptidases in synovial fluid from patients with rheumatoid arthritis (RA) and osteoarthritis (OA). Dipeptidyl peptidase IV (DPP IV) activity was lower in synovial fluid from patients with RA, in contrast to the increase of DPP II activity in synovial fluid, as compared with OA. The DPP II/DPP IV ratio for synovial fluid was significantly higher in patients with RA than in patients with OA. A significant correlation was observed between the DPP II/DPP IV ratio for synovial fluid from patients with RA and the amount of C-reactive protein reaction. These results may be useful in the diagnosis of joint effusion of unknown origin.
Somatotropin as measured by a two-site time-resolved immunofluorometric assay.
Authors: Strasburger C , Barnard G , Toldo L , Zarmi B , Zadik Z , Kowarski A , Kohen F 
Published: January 2020

Abstract
To date, many of the current criteria for diagnosis of somatotropin (growth hormone, GH) deficiency have been based upon measurement of this hormone by competitive radioimmunoassay (RIA) with use of polyclonal antibodies. In recent years, however, the development of hybridoma technology has led to the generation of various monoclonal antibodies (Mabs) to GH with different affinities and epitope specificities. Subsequently, these reagents have been used in the development of noncompetitive two-site immunometric assays (e.g., immunoradiometric assay; IRMA). In general, the values obtained for serum GH by IRMA have been lower than those obtained by RIA, because of the epitope-specificity profile of the Mabs in the IRMA. Attempting to obtain GH values numerically similar to those by RIA, we used a combination of Mabs to GH in developing and evaluating a two-site time-resolved immunofluorometric assay (IFMA) based on the streptavidin-biotin interaction. Fluorescence is proportional to concentration of analyte and is linearly related to concentration over the range 0.3 to 40 micrograms/L. The assay was satisfactory with respect to sensitivity, accuracy, and precision (CV less than 10% over the entire working range). In addition, the concentration of GH was determined by the IFMA and a competitive RIA in serum obtained from GH deficient and acromegalic patients. The pairing of antibodies in the IFMA gave numerical values that agreed well with those by RIA (r = 0.97; n = 100).
Serum mitochondrial aspartate aminotransferase activity: not useful as a marker of excessive alcohol consumption in an unselected population.
Authors: Schiele F , Artur Y , Varasteh A , Wellman M , Siest G 
Published: January 2020

Abstract
Using an immunochemical method, we measured the activity of the mitochondrial isoenzyme (mAST) of aspartate amino-transferase (EC 2.6.1.1, AST) in the serum of 687 subjects attending the Centre for Preventive Medicine for a health examination. The distributions of the activities were asymmetrical, with mean values of 1.8 U/L (SD 2.0) for men and 1.4 U/L (SD 1.6) for women. The average ratio of mitochondrial to total AST activity was 0.051 (range 0-0.42). In this unselected population we found no change in the mitochondrial activity or in the mitochondrial-to-total ratio attributable to alcohol consumption, even in subjects who consumed more than 88 g per day. Of 35 men with an alcohol consumption greater than 88 g/d, 19 had a serum gamma-glutamyltransferase activity of greater than or equal to 60 U/L, 17 had glutamate dehydrogenase values greater than or equal to 5 U/L, and only nine had an mAST activity greater than or equal to 3 U/L (values corresponding to the 80th percentiles of the total population). We conclude that the test is not particularly useful as a screening procedure in an unselected population under present-day conditions of measurement.
Influence of end-stage renal failure on concentrations of free apolipoprotein A-1 in serum.
Authors: Duval F , Frommherz K , Atger V , Drüeke T , Lacour B 
Published: January 2020

Abstract
We determined, immunoturbidimetrically, the concentrations of apolipoprotein A-I (apo A-I) (a) in total serum, (b) in total lipoproteins, and (c) in the fraction of d greater than 1.21 kg/L (free apo A-I) in 31 uremic patients (16 on hemodialysis, HD, and 15 with end-stage renal failure, ESRF) and 14 control subjects. The concentration of free apo A-I in serum was significantly increased in both groups of uremic patients (0.27 +/- 0.07 g/L for HD and 0.22 +/- 0.08 g/L for ESRF, mean +/- SD), in comparison with the control group (0.14 +/- 0.04 g/L). The ratio of total apo A-I to high-density-lipoprotein cholesterol was significantly increased in sera from both uremic groups, whereas the apo A-I/HDL-chol ratio of total lipoproteins was similar in all three groups. No apo A-I could be detected in five ultrafiltrates of plasma, even after 100-fold concentration. Analysis of apo A-I isoforms by isoelectrofocusing revealed a significant relative increase in apo A-I3 and a decrease in apo A-I5 isoform in ESRF patients, but not in HD patients. Finally, we found no relationship between serum TG and free apo A-I concentration.
HPLC measurement of phenylalanine by direct injection of plasma onto an internal-surface reversed-phase silica support.
Authors: Atherton N D 
Published: January 2020

Abstract
Direct-injection analysis for phenylalanine in plasma by isocratic "high-performance" liquid chromatography (HPLC) is described. For chromatographic separation I use an internal-surface reversed-phase silica support. The method involves ultraviolet detection, requires as little as 10 microL of plasma (routinely 20 microL), and supplies results in less than 7.5 min from injection. The intra-batch coefficient of variation for phenylalanine in human plasma samples (197-1104 mumol/L) ranged between 3.0% and 6.0% and the range of linearity was 10-1250 mumol/L for a 20-microL sample injection loop. The upper limit can readily be extended by using a smaller volume loop. Phenylalanine results from direct plasma injection (y) correlated well with those of a protein precipitation/HPLC technique (x): y = 0.931x + 46.4 (r = 0.951, n = 41, range 78-1344 mumol/L).
Specific routine determination of 3'-azido-3'-deoxythymidine (AZT) in plasma by partly automated liquid chromatography.
Authors: Kupferschmidt R , Schmid R W 
Published: January 2020

Abstract
A simple isocratic HPLC method for determining azidothymidine (AZT) in serum and plasma of patients has been developed. The novel, specific, two-step, solid-phase extraction approach used for sample preparation gives a nearly quantitative recovery (95.3%) of AZT from the blood plasma matrix and requires only minimal handling of infectious clinical samples. Automatic "on-line" injection is achieved with an AASP system by switching a small cartridge, which retains the extracted analyte, into the HPLC stream. The overall HPLC procedure shows satisfying reproducibility with low standard deviation (CV: 2.1%). Because of the low detection limit (about 10 ng) and the possibility of concentrating AZT quantitatively in as much as 5 mL of plasma or serum, the method can be used in routine monitoring of AZT as well as in pharmacokinetic studies. Nevertheless, before establishing therapeutic drug monitoring for AZT, it still must be determined at what time after the last AZT dose blood specimens should be drawn for correct therapeutic interpretation of the concentration of AZT measured in blood.
Prostatic inhibin-like peptide quantified in urine of prostatic cancer patients by enzyme-linked immunosorbent assay.
Authors: Teni T R , Bandivdekar A H , Sheth A R , Sheth N A 
Published: January 2020

Abstract
This is a highly specific enzyme-linked immunosorbent assay (ELISA) for measuring prostatic inhibin-like peptide (PIP) in urine, in which we use penicillinase (EC 3.5.2.6) conjugated with PIP and, as solid phase, a polystyrene microtiter plate. We used this ELISA to measure PIP in 24-h urine specimens from men with prostatic cancer (PCa) and from age-matched controls. For prostatic cancer patients the mean +/- SEM urinary PIP of 36.1 +/- 5 micrograms/24 h was significantly (P less than 0.001) lower than the mean of 127.1 +/- 9 micrograms/24 h for the age-matched controls. PIP values for 30 samples measured by both ELISA and RIA correlated well (r = 0.985). We could detect as little as 1.56 ng of PIP in a sample. Analytical recovery of added PIP ranged from 91% to 104%. Mean CVs were 8.9% within-assay and 12.7% between-assay. We believe that this ELISA will be useful in assessing the status of PIP in men with normal and diseased prostates and in examining the function of the hypothalamus-pituitary-prostate axis.
Determination of branched-chain amino acids and tyrosine in serum of patients with various hepatic diseases, and its clinical usefulness.
Authors: Azuma Y , Maekawa M , Kuwabara Y , Nakajima T , Taniguchi K , Kanno T 
Published: January 2020

Abstract
We developed an automated enzymatic method for determination of the branched-chain amino acids (BCAAs; valine, isoleucine, leucine) and tyrosine in serum, and applied it to the clinical evaluation of patients with various hepatic diseases. Analytically, the test results were acceptably precise and reproducible, and correlated well with results obtained with an amino acid analyzer. Clinically, we found that a decrease in BCAAs, an increase in tyrosine, and the BCAAs/tyrosine ratio in serum paralleled the severity of hepatic parenchymal damage. We conclude that this enzymatic determination of BCAAs and tyrosine is simple and convenient enough for routine clinical laboratory use, and that the ratio of BCAAs/tyrosine obtained may be a good indicator of the severity of hepatic disorders.
Radioimmunoassay of osteocalcin with polyclonal and monoclonal antibodies.
Authors: Power M J , Gosling J P , Fottrell P F 
Published: January 2020

Abstract
We have developed and thoroughly validated radioimmunoassays (RIAs) for osteocalcin in plasma and serum, demonstrating independence of volume and determining the recovery of added standard and within- and between-assay precision. Antibodies were raised in rabbits and mice by immunization with either osteocalcin adsorbed to polyvinylpyrrolidone or osteocalcin conjugated to bovine serum albumin. In both species, use of the conjugated osteocalcin was more efficacious. Correlation of the results obtained when groups of plasma or serum samples were analyzed by RIAs with different antibodies (two polyclonal and one monoclonal) indicated that the normal range observed for osteocalcin concentrations in serum depends on the antibody used. These findings may account for the wide range of "normal" osteocalcin values reported by different groups.
A rapid micro-scale procedure for determination of the total lipid profile.
Authors: Wu L L , Warnick G R , Wu J T , Williams R R , Lalouel J M 
Published: January 2020

Abstract
We describe a one-day micro-scale procedure for determining the total lipid profile. Only 0.55 mL of plasma is needed for complete quantification of total cholesterol (TC), triglyceride (TG), and all lipoproteins. After precipitation with dextran sulfate and magnesium, the high-density lipoprotein (HDL) fraction was separated by centrifugation in an Eppendorf microcentrifuge. Very-low-density lipoprotein (VLDL) was separated from low-density lipoprotein (LDL) plus HDL in a Beckman TL 100 ultracentrifuge. TC, TG, and cholesterol in different lipoprotein fractions were measured enzymatically in a Baker "Encore II" automated analyzer. CVs, both within-day and day-to-day, were less than 3% for TG and TC, and less than 5% for HDL-C determinations. CVs for LDL-C and VLDL-C were less than 7.5% and 15%, respectively. Results by our micromethods (n = 66) agreed well with those by the conventional methods used at the Northwest Lipid Research Center, which are standardized against the Reference Methods of the Centers for Disease Control. Coefficients of correlation between the two methods were 0.98 for TC, 1.0 for TG, 0.98 for HDL-C, 0.94 for LDL-C, and 0.96 for VLDL-C. Results of electrophoresis on agarose gel and radioactivity-recovery studies indicate that our micro-centrifugation and slicing procedures result in clean separation of VLDL from other lipoproteins.
Loss of porphyrins from solution during analysis: effect of sample pH and matrix on porphyrin quantification in urine by "high-performance" liquid chromatography.
Authors: Perkins S L , Johnson P M 
Published: January 2020

Abstract
We report the effect of sample matrix and pH on quantification of porphyrins by HPLC with fluorimetric detection. For aqueous solutions of pH less than 2.5, HPLC peak heights of the porphyrins increased with decreasing pH, reaching a plateau at pH less than 1.0. This loss of porphyrins from solutions with pH greater than 1.0 appeared to be due to a combination of microprecipitation and aggregation effects. No such "pH effect" was observed for urine samples supplemented with mixed-porphyrin standards. Addition of trace amounts of albumin to aqueous solutions also decreased these pH-related losses. These findings suggest a porphyrin-protein interaction that prevents microprecipitation and aggregation processes. We conclude that standard solutions of porphyrins for HPLC analysis should be prepared in a urine matrix. If aqueous solutions are used, then the pH must be adjusted to less than 1.0. Urine samples from normal individuals require only adjustment of pH to less than 2 before analysis; however, porphyric urines requiring dilution should be prepared with porphyrin-free urine diluent.
Two whole-blood multi-analyte analyzers evaluated.
Authors: Fleisher M , Gladstone M , Crystal D , Schwartz M K 
Published: January 2020

Abstract
We evaluated two multi-analyte analyzers, the NOVA Stat Profile 1 (SP 1) and the NOVA Stat Profile 5 (SP 5). The SP 1 measures pH, pCO2, pO2, sodium, potassium, ionized calcium, and hematocrit in heparinized whole blood; the SP 5 determines all these analytes, plus chloride (not evaluated because it was unavailable at the time this study was initiated) and glucose. Interassay precision for pH, pCO2, pO2, sodium, potassium, ionized calcium, and hematocrit (all on the SP 1) and glucose (on the SP 5) was excellent, the respective CVs (%) being: less than 0.006, 2.1, less than or equal to 3.0, less than or equal to 0.5, less than or equal to 1.7, less than or equal to 2.1, less than or equal to 3.9, and less than or equal to 1.2. Correlation with results obtained with Corning's Model 178, NOVA Biomedical's Model 6, Beckman's Astra 8, and Roche's Cobas-Bio was also excellent (r greater than 0.975 for all analytes, r for hematocrit 0.865). Temperature-stability studies on whole-blood specimens maintained at 1 degree C indicated that results for all measured analytes were essentially uncharged for at least 2 h, except for potassium, which increased by 13% in 2 h. At 22 degrees C, values for pH, pCO2, pO2, and glucose changed significantly within 2 h. Advantages of the NOVA Stat Profile series include decreased specimen requirements (250 microL), analysis time (72-90 s), turnaround time (about 4.5 min), and overall cost of operation.