bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lactate dehydrogenase isoenzyme pattern in sera of patients with malignant diseases.
Authors: Giannoulaki E E , Kalpaxis D L , Tentas C , Fessas P 
Published: January 2020

Abstract
Total lactate dehydrogenase (LDH; EC 1.1.1.27) activity and the percentage distribution of LDH isoenzymes were determined in 127 patients with malignant diseases. A shift in the isoenzyme patterns was observed toward the M-type, with an increase in the percentage of LDH-4 and LDH-5 isoenzymes and a slight increase in total LDH activity of all patients. Serum samples from 68 of the patients contained an abnormal isoenzyme of LDH, "LDH-1 ex," that, on agarose gel electrophoresis at pH 8.6, migrated between albumin and LDH-1 isoenzyme. Chemotherapy, radiotherapy, or surgical removal of the tumor was accompanied by disappearance of this abnormal isoenzyme. The heat stability of LDH-1 ex isoenzyme appears to be similar to that of LDH-1 but greater than that of the other LDH isoenzymes. Statistical analysis of these data demonstrated a significant correlation between malignancy and the appearance of LDH-1 ex isoenzyme (P less than 0.001). In contrast, the relationship between LDH-1 ex isoenzyme and metastasis or anatomical location of the malignancy is not statistically important (P less than 0.1).
Pancreatic oncofetal antigen and carbohydrate antigen 19-9 in sera of patients with cancer of the pancreas.
Authors: Shahangian S , Fritsche H A , Hughes J I , Gelder F B 
Published: January 2020

Abstract
Pancreatic oncofetal antigen (POA) and carbohydrate antigen 19-9 (CA 19-9) were measured in the sera of 23 patients with cancer of the pancreas to determine the true positive rates of these cancer markers. In one group of unselected pancreatic cancer patients (n = 9), both tests showed above-normal results in three patients and both gave values that were within reference limits in three other patients. Two of the three remaining patients had increased CA 19-9 but normal POA values, and one patient had increased POA but normal CA 19-9 concentrations in serum. In another group of 14 pancreatic cancer patients, selected on the basis of increased concentrations of POA in serum, the CA 19-9 values were increased in eight. In four patients who had progressive disease, the concentrations of both markers increased with time in one patient, only POA in one, and only CA 19-9 concentration in another. (The fourth patient had increased but stable concentrations of POA and CA 19-9 in serum.) These data suggest that serum POA and CA 19-9 measurements should be used in combination in the evaluation of patients with cancer of the pancreas.
Standardization of a commercial (Boehringer Mannheim diagnostics) enzymic method for cholesterol.
Authors: Warnick G R , Spain M , Kloepfer H , Volke T M 
Published: January 2020

Abstract
The Laboratory Standardization Panel of the National Cholesterol Education Program recommends that cholesterol method accuracy ideally be within 3% of the true value determined by the Abell-Kendall Reference Method, a component of the National Reference System for Cholesterol. As one of the Abell-Kendall network laboratories established to facilitate cholesterol standardization, the approach we recommend for determining accuracy involves a comparison analysis on patients' specimens by the method in question and by the Abell-Kendall method. Use of fresh specimens precludes matrix interactions that may influence enzymic measurement. Using this approach, we assessed an enzymic method for cholesterol with two instruments (Boehringer Mannheim/Hitachi 717 and 737), with BMD reagent, controls, and calibrator. Fresh and frozen sera were analyzed with both instruments over three days. The Abell-Kendall method was used at the Northwest Lipid Research Center on frozen aliquots of the same sera. Both instruments demonstrated good agreement with the Reference Method, as determined by linear regression; overall bias averaged less than -2% for the Hitachi 717 and -1% for the Hitachi 737 at 2000 mg/L--i.e., within the accuracy recommendation. We observed a difference in bias for fresh and frozen specimens; with the Hitachi 717, fresh specimens exhibited -3% bias at 2000 mg/L, but there was virtually no bias of determinations of frozen specimens.
Diagnosis of acute myocardial infarction from two measurements of creatine kinase isoenzyme MB with use of nonparametric probability estimation.
Authors: Bernstein L H , Good I J , Holtzman G I , Deaton M L , Babb J 
Published: January 2020

Abstract
By using bivariate probability estimation for the diagnosis of acute myocardial infarction (AMI) we show how to overcome the difficulties encountered for patients whose clinical presentation is atypical and those encountered when multiple isoenzyme determinations are treated by univariate methods. We use the values for creatine kinase isoenzyme MB measured at the time of admission and 12 h later to estimate the Bayes factors in favor of AMI. The Bayes factors are compiled into a table that the clinician can use to estimate the posterior probability that a patient has AMI. The table of Bayes factors is based on data for a sample of 802 non-AMI patients and 180 AMI patients. Further to validate the method, we randomly chose 200 of the non-AMI and 50 of the AMI patients as an evaluation sample, then used the remaining 602 non-AMI and 130 AMI patients to recompute the Bayes factors. These Bayes factors were used to find the probability of AMI for each of the 250 patients in the evaluation sample. The method resulted in only one false positive and no false negatives. For the misclassified patient the measurements at admission and 12 h later were 1 and 11 U/L; the posterior odds were 15 to 1 in favor of AMI, but in fact the patient was non-AMI.
Automated determination of drugs in serum by column-switching high-performance liquid chromatography. IV. Separation of tricyclic and tetracyclic antidepressants and their metabolites.
Authors: Matsumoto K , Kanba S , Kubo H , Yagi G , Iri H , Yuki H 
Published: January 2020

Abstract
We describe automated column-switching high-performance liquid chromatography for determining nine tricyclic and tetracyclic antidepressants (TCAs) and their metabolites in human serum. TSKgel ODS-80TM and TSKprecolumn PW (Tosoh Co., Tokyo) are used in the analytical column and the precolumn, respectively. A 200-microL serum sample is directly injected onto the precolumn. After washing the serum proteins from the precolumn with potassium phosphate buffer, the precolumn connection is switched to introduce the retained substances onto the analytical column. The drugs are then eluted within 30 min with an acetonitrile/potassium phosphate buffer mixture containing sodium 1-heptanesulfonate. The analytical recoveries (95-104%), reproducibilities (within-run CV less than 3%), and detection limits (10 micrograms/L) indicate that this HPLC system is suited for therapeutic drug monitoring. Correlations were good between the TCA concentrations in serum and administered dose (r = 0.713, n = 41), and between 10-hydroxynortriptyline and nortriptyline in serum (r = 0.691, n = 24).
Monoclonal immunoglobulins: affinity blotting for low concentrations in serum.
Authors: McLachlan R 
Published: January 2020

Abstract
I describe a simple, economical technique for identifying low concentrations of monoclonal immunoglobulins in the presence of excessive amounts of immunoglobulins of other classes. The technique involves binding of specific antibody to nitrocellulose, separating proteins by isoelectric focusing or zone electrophoresis in agarose gels, using capillary transfer to bind proteins to the nitrocellulose via their antibody affinity, and then detecting transferred proteins with enzyme-labeled antibody. A monoclonal immunoglobulin can be completely characterized in 2 h. No expensive equipment is required. Affinity blotting is about 10-fold as sensitive as native blotting, 100-fold as sensitive as silver staining.
An algorithm for testing and reporting serum choriogonadotropin at clinically significant decision levels with use of "pregnancy test" reagents.
Authors: Bandi Z L , Schoen I , Waters M 
Published: January 2020

Abstract
We present an algorithm for monitoring the concentration of human choriogonadotropin (hCG) in serum at various clinical decision levels with use of fast, simple, and cost-effective qualitative pregnancy test reagents for hCG in serum. Based on correlation between laboratory data and clinical observations described in the literature, the following concentrations of hCG in serum can be considered as clinically significant decision levels: 5 int. units/L to exclude or "rule out" the presence of increased hCG; 25 int. units/L for "confirming pregnancy" or confirming the presence of increased hCG from sources other than the trophoblast; and 6500 and 82 500 int. units/L to enhance the sonographic diagnoses of ectopic pregnancies and molar pregnancies, respectively. We used Tandem Icon II (Hybritech) pregnancy test reagents and evaluated the reagents for possible "false-positive" findings at the 25 int. units/L limit of hCG detectability by analyzing 100 post-menopausal and more than 4000 premenopausal serum specimens. The performance of the reagents was validated also at 5 int. units/L and at limits of hCG detectability greater than 25 int. units/L.
Cyclosporine concentrations in blood after liver transplantation: correlation of immunoassay results with clinical events.
Authors: Haven M C , Sobeski L M , Earl R A , Markin R S 
Published: January 2020

Abstract
To investigate the clinical utility of immunoassays for cyclosporine and metabolites in plasma and whole blood, we monitored 25 patients after orthotopic liver transplantation. We compared cyclosporine as measured by TDx fluorescence polarization immunoassay (of both plasma and whole blood) and by two polyclonal radioimmunoassays (from Sandoz and INCSTAR). We found considerable differences in measured cyclosporine concentrations, which were dependent on method, matrix, and clinical condition. Correlation coefficients between results by the various methods for samples from individual patients ranged from 0.825 to 0.996. The three methods used for monitoring cyclosporine in whole blood gave proportional results (Sandoz less than INCSTAR less than TDx) in individual patients, but results for the two methods for plasma sometimes differed by more than 100%. In some cases, ratios of plasma cyclosporine concentration (result by TDx/result by Sandoz) were correlated with disturbances in hepatic excretory function or kidney function. This ratio may be useful in monitoring for nephrotoxicity.
A system for toxicological screening by capillary gas chromatography with use of a drug retention index based on nitrogen-containing reference compounds.
Authors: Manca D , Ferron L , Weber J P 
Published: January 2020

Abstract
Capillary gas chromatography with nitrogen-specific detection allows rapid screening of numerous drugs of toxicological interest. However, for accurate identification of individual peaks, the system must be well calibrated, e.g., through the use of retention indices (RI). To overcome problems associated with the use of RI's based on homologous series determined with nitrogen-specific detectors, we have developed an RI reference system based on molecular masses and retention times of nitrogen-containing compounds. The standards chosen are easily available in highly purified form and can be detected by the unmodified nitrogen-specific detector. By using temperature programming, we can obtain a linear relationship between the molecular masses of standards and their retention times. Used in conjunction with microcomputer data handling, this screening system is rugged and reliable, operating 22 h per day. In the past two years, we have screened greater than 3000 samples (blood, serum, urine, gastric lavage) without major problems.
Determination of cyclosporine in plasma: specific radioimmunoassay with a monoclonal antibody and liquid chromatography compared.
Authors: Vernillet L , Keller H P , Le Bigot J F , Humbert H 
Published: January 2020

Abstract
A radioimmunoassay of cyclosporine (Sandimmune) involving use of a mouse monoclonal antibody was tested to monitor specifically the parent drug in plasma. The cyclosporine concentrations obtained by RIA were compared with those obtained by the HPLC method. For the RIA method, the within- and between-assay CVs are less than 6%, the limit of detection is about 10 micrograms/L for a 50-microL sample of plasma. For the HPLC method, the within- and between-assay CVs are less than 20%, the limit of detection is about 15 micrograms/L for a 1-mL sample of plasma. The concentrations by RIA correlated well with those by HPLC in samples from patients receiving bone-marrow (n = 39), heart (n = 52), or liver (n = 51) transplants. In all indications, the ratio of values by RIA to those by HPLC for these samples remained stable and close to 1 during the drug-monitoring period, i.e., for up to 202 days. Therefore, the specific RIA can be used instead of HPLC to measure the parent drug in plasma.
Methods compared for determining total amylase activity and amylase isoenzymes in serum.
Authors: Badenoch J L , Bals R 
Published: January 2020

Abstract
We evaluated two kinetic methods for determining total amylase activity and isoenzyme composition in serum. Stability studies of reagents for measuring total activity indicate that reagents containing 4-nitrophenyl-alpha-glucosides or enzyme-linked reagents can be stored only for seven days at 4 degrees C. Methods based on 4-nitrophenyl-alpha-glucoside substrates cannot be used if the reagent absorbance at 405 nm exceeds 2. However, in the alpha-amylase EPS method (Boehringer Mannheim) an ethylidene-protected 4-nitrophenyl-alpha-D-maltoheptaoside substrate is stable for up to 28 days after reconstitution. Further studies indicated that the Amylase-DS (Beckman) and the alpha-Amylase EPS standard curves are linear to at least six times the upper limit of the reference interval. Within-batch imprecision (CV less than 1.1%) and between-batch imprecision (CV less than 3.3%) for these two methods are comparable with those for other kinetic methods, and there is excellent correlation (r2 = 0.983) between the two methods. The reference interval, determined by use of samples from 90 healthy blood donors, is 31 to 141 U/L for the amylase-DS method, 22 to 92 U/L for the alpha-Amylase EPS method. We also used these two methods to measure amylase isoenzymes after inhibiting the salivary isoenzyme with either a lectin or a monoclonal antibody. We found the monoclonal antibody method more specific than the lectin inhibition method for determining the isoenzymes.
Serum creatine kinase isoenzyme BB is a poor index to the size of various brain lesions.
Authors: Schwartz J G , Bazan C , Gage C L , Prihoda T J , Gillham S L 
Published: January 2020

Abstract
We divided patients with brain lesions into three groups: (a) patients with primary or metastatic brain cancer, (b) brain infarctions, and (c) brain contusion(s). We analyzed each patient's sera for creatine kinase isoenzyme BB (CK-BB), using a monoclonal antibody kit (Impres-BB; International Immunoassay Laboratories). Computerized axial tomography (CAT) scans were performed on each patient. The size of the various lesions was measured from the CAT scan and recorded in milliliters. Total CK, CK-BB, and their ratios were compared with the volume of damaged brain tissue. We found no correlation between any of the variables and the various brain lesions. We attribute this lack of correlation to an intact blood-brain barrier, the rapid elimination or inactivation of CK-BB, or some combination of these factors.
An alpha slow-moving high-density-lipoprotein subfraction in serum of a patient with radiation enteritis and peritoneal carcinosis.
Authors: Peynet J , Legrand A , Messing B , Thuillier F , Rousselet F 
Published: January 2020

Abstract
An alpha slow-moving high-density-lipoprotein (HDL) subfraction was seen in a patient presenting with radiation enteritis and peritoneal carcinosis, who was given long-term cyclic parenteral nutrition. This subfraction, observed in addition to normal HDL, was precipitated with low-density lipoproteins (LDL) and very-low-density lipoproteins (VLDL) by sodium phosphotungstate-magnesium chloride. The patient's serum lipoproteins were analyzed after fractionation by density gradient ultracentrifugation. The alpha slow-moving HDL floated in the ultracentrifugation subfractions with densities ranging from 1.028 to 1.084 kg/L, and their main apolipoproteins included apolipoprotein E in addition to apolipoprotein A-I. These HDL were larger than HDL2. The pathogenesis of this unusual HDL subfraction is hypothesized.
Use of DNA probes in detecting carriers of Duchenne muscular dystrophy: selected case studies.
Authors: Prior T W , Blasco P A , Dove J L , Leshner R T , Gruemer H D 
Published: January 2020

Abstract
Detection of Duchenne muscular dystrophy carriers by genetic analysis is illustrated by four case studies. The technique is most useful in obligate families, in excluding carrier status in isolated cases, and in families in which the affected child demonstrates a molecular deletion. A major limitation of this technique is that the accuracy of carrier status in isolated (i.e., no family history) cases is limited by the probability that the affected child may represent a new mutation. To improve the carrier risk estimate generated by the DNA data, particularly in isolated cases, we suggest that measuring creatine kinase activities in the serum and performing the genetic analysis on the nonaffected males may be helpful.
Modulated adhesion: a proposal for the role of myelin-associated glycoprotein in myelin wrapping.
Authors: Attia J , Tropak M , Johnson P W , Newerly-Abranow W , Pawson T , Roder J C , Dunn R J 
Published: January 2020

Abstract
Myelin-associated glycoprotein (MAG) is a 100-kDa integral membrane glycoprotein expressed by oligodendrocytes and Schwann cells in the central and peripheral nervous systems, respectively. It is found first in loosely wrapped myelin and then periaxonally after compaction. Clinical findings, structural analysis, and cell assays indicate a role for MAG in adhesion. We propose that the phosphorylation state of MAG modulates its adhesion and that a minimum spatial requirement for the separation of the kinase and phosphatase activities postulated by this model may explain the correlation between axon size and myelination state.
Genes encoding neuronal nicotinic acetylcholine receptors.
Authors: Deneris E S , Boulter J , Connolly J , Wada E , Wada K , Goldman D , Swanson L W , Patrick J , Heinemann S 
Published: January 2020

Abstract
Four genes (alpha 2, alpha 3, alpha 4, and beta 2), which encode proteins homologous to the Torpedo electric organ and vertebrate muscle nicotinic acetylcholine receptors, have been identified by cloning rat brain cDNAs. Injection of transcripts derived from these cDNAs into Xenopus laevis oocytes results in the formation of three nicotinic acetylcholine receptors. Two of these receptors, alpha 3/beta 2 and alpha 4/beta 2, have the characteristics of ganglionic nicotinic receptors. The third (alpha 2/beta 2) exhibits a previously undescribed pharmacology and thus represents a novel subtype that may be expressed in the brain. The wide distribution of alpha 2, alpha 3, alpha 4, and beta 2 transcripts in the brain indicates that neuronal nicotinic acetylcholine receptors are a major neurotransmitter receptor system.
Isolation and characterization of myoglobin and its two major isoforms from sheep heart.
Authors: Wu J T , Pieper R K , Wu L H , Peters J L 
Published: January 2020

Abstract
We isolated myoglobin from sheep heart by homogenizing cardiac muscle in 70%-saturated ammonium sulfate, followed by chromatography on a column containing carboxymethyl(CM)-Sephadex gel. Two major isoforms of myoglobin, designated Mb 7.9 and Mb 8.1, were separated by chromatofocusing and were distinguished by their different patterns seen on either isoelectrofocusing or on electrophoresis on polyacrylamide gel. The isoelectric points of the major bands of Mb 7.9 and Mb 8.1 were 7.4 and 7.16, respectively. Both isoforms were identical in size when examined by gel filtration chromatography but differed slightly when analyzed by polyacrylamide gradient gel in the presence of sodium dodecyl sulfate. The Mr of Mb 7.9 (15,900 Da) is slightly smaller than that of Mb 8.1 (18,400 Da). When reacted against rabbit anti-sheep myoglobin, two isoforms also appeared as two nonidentical precipitin lines on agarose gel.
Direct determination of four sulfates and seven glucuronides of 17-oxosteroids in urine by fluorescence "high-performance" liquid chromatography.
Authors: Iwata J , Suga T 
Published: January 2020

Abstract
We describe a direct method for determining four sulfates and seven glucuronides of 17-oxosteroids (17OS) in urine without hydrolysis, by use of "high-performance" liquid chromatography (HPLC) with fluorometric detection. After pretreatment of urine samples with a Sep-Pak C18 cartridge, four 17OS sulfates and seven 17OS glucuronides in the pretreated urine samples were reacted with tetrapentylammonium ions to form ion pairs. Ion-paired 17OS sulfates were extracted with benzene. By adding sodium sulfate to the remaining sample, we could then extract ion-paired 17OS glucuronides with dichloromethane. Each extract was labeled with dansyl-hydrazine in an acetic acid-acetonitrile solution. The labeled steroids were separated by HPLC on a reversed-phase Capcell-Pak C8 (silicon-polymer-coated silica gel modified with octyl groups). We monitored each effluent with a fluorometric detector (330 nmexcitation, 535 nmemission).
Phospholipid surface tension: the diagnostic utility of amniotic fluid and its lipid extract, an analysis of the value of precipitation with cold acetone.
Authors: Ruiz Budría J , Abbad Bara J M , Fabre Gonzalez E , Higueras Sanz M T , Serrano Ostáriz J L 
Published: January 2020

Abstract
In prevention of the respiratory distress syndrome (RDS), measurements of surface tension values (a biophysical property) of amniotic-fluid samples are correlated with their lecithin/sphingomyelin (L/S) ratios (a biochemical property). According to some authors, precipitation of phospholipid with cold acetone is essential for determining the L/S ratio, because it separates surfactant and nonsurfactant phospholipidic fractions. Here we report the first study of the ability of three amniotic-fluid components to decrease surface tension: The complete lipid extract (without precipitation), and the fractions precipitated and (or) remaining soluble after addition of cold acetone. Addition of increasing aliquots of lipid extracts to these three samples showed that: (a) measurement of surface tension rapidly and reliably indicates fetal lung maturity, and (b) both precipitated and soluble phospholipid fractions decrease surface tension similarly, making it unlikely that the precipitation step in fact separates surfactant and nonsurfactant material.