bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relationships between immunogen structure and antisera specificity in the narcotic alkaloid series.
Authors: Findlay J W , Butz R F , Jones E C 
Published: January 2020

Abstract
We report the production and comparative specificities of antisera raised to different immunogens containing codeine, morphine, and oxycodone. Antisera raised to bovine serum albumin (BSA) conjugates of codeine-6-hemisuccinate, ethylmorphine-6-hemisuccinate, or oxycodone-6-carboxymethyloxime had greatest recognition of structural changes around the piperidine ring nitrogen atom and th 14-position. N-carboxypropylnormorphine-BSA, N-carboxypropylnorcodeine-BSA, and norcodeine-BSA (directly coupled) conjugates elicited antisera that recognized structural changes at the 3- and 6-positions best, but also clearly discerned changes in the 14-substituent. Attachment of codeine to BSA via the 8-position gave a conjugate that elicited antisera with specificity characteristics similar to those of the antiserum to N-carboxypropylnorcodeine-BSA. Thus clear relationships existed between immunogen structure and antiserum specificity. The utility of these antisera was illustrated by the application of antiserum to codeine-6-hemisuccinate-BSA and solvent extraction to a study of codeine disposition in the dog. The specific antisera of N-carboxypropylnormorphine-BSA and to norcodeine-BSA were applied directly to an examination of the distribution of codeine and metabolically produced morphine in the milk and plasma of a nursing mother.
On-line cleavage of urinary estriol conjugates with immobilized beta-glucuronidase before liquid-chromatographic analysis.
Authors: Bowers L D , Johnson P R 
Published: January 2020

Abstract
Urinary estriol measurement has been widely accepted as a useful indicator of fetoplacental status. Classically, glucuronide conjugates of estriol have been cleaved with soluble beta-glucuronidase (EC 3.2.1.31) before extraction and measurement. We have developed a system in which urine is injected directly into a "high-performance" liquid chromatograph and the conjugates are cleaved on-line in an immobilized beta-glucuronidase reactor. Estriol is quantitated with fluorescence detection after separation from other interfering species with a reversed-phase column. The stability of the immobilized enzyme under storage conditions and in the presence of the mobile phase are discussed. Only 150 mL/L methanol could be pumped through the reactor and onto the analytical column, but this allowed on-column preconcentration of the free estriol produced. Gradient elution bypassing the immobilized enzyme reactor eluted the compounds of interest without damaging the enzyme. Comparison with radioimmunoassay results yielded a slope of 0.97 (r = 0.996, n = 19).
Improved isocratic liquid-chromatographic simultaneous measurement of phenytoin, phenobarbital, primidone, carbamazepine, ethosuximide, and N-desmethylmethsuximide in serum.
Authors: Szabo G K , Browne T R 
Published: January 2020

Abstract
We describe an improved "high-pressure" liquid-chromatographic assay for simultaneous determination in serum of the five major antiepileptic drugs (ethosuximide, primidone, phenobarbital, phenytoin, and carbamazepine) and N-desmethylmethsuximide (the compound that must be quantitated for therapeutic drug monitoring of the antiepileptic drug methsuximide). Serum protein is precipitated with an acetone solution containing 5-ethyl-5-(p-methylphenyl)barbituric acid as the internal standard. The centrifuged supernate is injected onto the chromatographic column. Drugs and internal standard are eluted at 30 degrees C with mobile phase containing acetonitrile/methanol/phosphate buffer (17/28/55 by vol) at a flow rate of 0.7 mL/min, monitored at 195 nm. Analysis time is about 20 min. Quantitation is by measurement of peak areas. Analytical and absolute recoveries varied from 95 to 104%. Within-day coefficients of variation ranged from 1.6 to 5.4%, between-day CVs from 0.0 to 3.4% in subtherapeutic, therapeutic, and toxic samples. Resolution of therapeutic concentrations of all six drugs was complete. As yet, we have found no drug or drug metabolite that interferes.
Laboratory evaluation of the Boehringer Mannheim "Diagnostic M" automated discrete analyzer.
Authors: Robinson C A , Proelss H , Stabler T V 
Published: January 2020

Abstract
We evaluated a new multiple-channel chemistry analyzer, the Boehringer Mannheim "Diagnostic M." This instrument can perform 25 tests at the rate of 120 1.3-mL serum samples per hour. The instrument may be run in either a profile mode or single-test mode. In the single-test mode only the necessary reagent is pumped. the instrument is computer controlled. We compared it with the Technicon SMAC, SMA 12/60, and SMA 6/60. It demonstrated excellent precision, linearity, lack of interference, ease of operation, and satisfactory comparison with values obtained by the Technicon methods.
Assays of serum lipase by the "BALB-DTNB method" mechanized for use with discrete and continuous-flow analyzers.
Authors: Furukawa I , Kurooka S , Arisue K , Kohda K , Hayashi C 
Published: January 2020

Abstract
We successfully adapted the dimercaprol (BAL) tributyrate-5,5'-dithiobis(2-nitrobenzoic acid) method (J. Biochem. 81: 361, 1977) for assay of lipase in human serum to a discrete analyzer (the TBA 880) (I) or a continuous-flow analyzer (AutoAnalyzer, Type II) (II). In both, BAL-tributyrate is used as substrate, in combination with serum esterase inhibitors and a chromogenic reagent for the SH group of the liberated BAL. Serum lipase activities of patients with pancreatic diseases, measured at 90 or 40 samples per hour by I or II, respectively, correlated well with those measured by the corresponding manual method or by Kaplan's radioassay (Anal. Biochem. 33: 213, 1970). The correlation coefficients were all greater than 0.95, and the coefficients of variation were less than 8%, showing the practical usefulness of these procedures.
Enzyme immunoassay of thyroxin with a centrifugal analyzer.
Authors: Izquierdo J M , Sotorrío P , Quirós A 
Published: January 2020

Abstract
We have applied a homogeneous enzyme immunoassay for determination of thyroxin in serum to the "Cobas Bio" centrifugal analyzer. To unbind thyroxin from its protein complex, serum is treated for 20 min with a solution of NaOH containing "Lipex," an agent for sequestering free fatty acids. The immunoenzymic reaction is then automatically performed by the analyzer at 37 degrees C. To 20 microL of sample mixture is added 125 microL of reagent (thyroxin antibodies and NAD+) and this mixture is incubated for 10 s. Then 25 microL of start reagent (enzyme-thyroxin conjugate and malate substrate) is added and the change in absorbance is monitored at 340 nm. The standard curve is linear up to at least 200 micrograms of thyroxin per liter. Within-assay precision (CV) varied from 1.1 to 2.9%, between-assay precision from 3.1 to 7.8%. Analytical recovery of thyroxin was complete. The deviation of control samples from target values ranged from -2.1% to 7.0%. Interference by hemoglobin or bilirubin is negligible. Results compare favorably with those by radioimmunoassay.
Comparative evaluation of two calcium ion-selective electrode systems, and their utility for monitoring steady-state changes in [Ca2+].
Authors: Drop L J , Tochka L N , Misiano D R 
Published: January 2020

Abstract
We compared ionized calcium concentrations ([Ca2+]) as measured with two ionized-calcium analyzers: the NOVA 2 and the Orion SS-20. Samples were obtained from 43 human volunteers, 213 patients, and five dogs (106 samples). In the [Ca2+] range of 0.85 to 1.8 mmol/L, [Ca2+] measurements in whole blood with the NOVA 2 consistently exceeded those measured with the Orion SS-20. However, in the normal range, this difference appeared to be smaller when we compared values for plasma or serum, and was absent over the entire range when we compared aqueous solutions. The normal human [Ca2+] in whole blood as measured with the NOVA 2 is 1.22 +/- 0.01 mmol/L (mean +/- SEM) and that with the Orion SS-20 is 1.12 +/- 0.01 mmol/L (p less than 0.0001 by paired t-test); the 95% confidence intervals were from 1.14 to 1.30 and from 1.02 to 1.22 mmol/L, respectively. Using dogs, we also tested the usefulness of the ionized-calcium electrode for monitoring [Ca2+] during infusion of either citrate or calcium chloride solutions, to produce steady-state alterations in [Ca2+] equilibrium. Frequent successive [Ca2+] measurements were essential to appropriately adjust the infusion rates of these solutions to achieve steady-state [Ca2+].
Hemoglobin A1 in hemolysates from healthy and insulin-dependent diabetic children, as determined with a temperature-controlled minicolumn assay.
Authors: Kaplan L A , Cline D , Gartside P , Burstein S , Sperling M , Stein E A 
Published: January 2020

Abstract
We report age-specific glycohemoglobin values for nondiabetic infants, children, and young adults. These values were determined with an ion-exchange "mini-column" in a specially designed and constructed water bath that maintains column temperature at 23 +/- 0.1 degrees C. Two in-house-prepared controls with glycohemoglobin content amounting to 6.36% and 11.87% of total hemoglobin, stored at -20 degrees C, were used to assess long-term analytical precision. Between-day precision (CV) was 1.4% and 1.65%, respectively. We found a significant correlation (r = 0.981, p less than 0.01) between the glycohemoglobin value and the physicians' independent assessment of clinical control in 129 insulin-dependent diabetics, ages 3-23 years. There were significant differences (p less than 0.05) between glycohemoglobin values between patients with well-controlled or poorly controlled diabetes and those with intermediate control. Reported studies of 20 patients over three to 12 weeks showed that changes in clinical control were paralleled by changes in glycohemoglobin values.
Evaluation of a new serum separator.
Authors: Seckinger D L , Antonio Vazquez D , Rosenthal P K , Heller Z H 
Published: January 2020

Abstract
We tested the Centri-Sep filter (DADE) for its effectiveness in separating serum from clotted blood samples used for chemical analysis. Although statistical analysis by paired t-test showed differences in results for some analytes with the use of this device as compared with use of no separator or of a serum-decanting device, we concluded from the small bias of the paired means that the new separator device did not interfere with the clinical usefulness of reported values for the analytes studied. The separator is not an effective barrier for long-term storage of serum on its clot; however, we could obtain about 10% more serum with the separator than with decanting devices.
Proteins of human urine. II. Identification by two-dimensional electrophoresis of a new candidate marker for prostatic cancer.
Authors: Edwards J J , Anderson N G , Tollaksen S L , von Eschenbach A C , Guevara J 
Published: January 2020

Abstract
A protein series common to the urine and prostatic tissue of 16 of 17 patients with prostatic adenocarcinoma has been identified by high-resolution two-dimensional gel electrophoresis. These proteins, designated PCA-1, have a relative molecular mass in sodium dodecyl sulfate of about 40000. Analyses of urines from eight age-matched controls, seven patients with other ty pes of urogenital malignancies, two patients with benign prostatic hyperplasia, and five patients with malignancies not associated with the urogenital system failed to show PCA-1 in the patterns. These preliminary findings suggest that this protein should be systematically investigated as a candidate marker for prostatic adenocarcinoma in man.
Colorimetry of serum acetaminophen (paracetamol) in uremia.
Authors: Bailey D N 
Published: January 2020

Abstract
A popular colorimetric analysis for serum acetaminophen, based on ring-nitration of the drug, is demonstrated to yield both "false positives" and erroneously high results for serum from uremic patients. The interference appears to be anionic at physiological pH, and correlates significantly with serum creatine concentration and with the magnitude of the "anion gap." A modification of the analysis involving extraction of the acetaminophen with ether eliminates the interference. As little as 10 mg of drug per liter can be accurately measured in serum by the proposed procedure. Analytical recovery was 97% at a concentration of 1 g/L. Coefficients of variation for the analysis at respective concentrations of 100 and 500 mg/L were: within-run, 2.7% and 2.0%; between-run, 3.1% and 4.2%. I encountered no serious interferences from other drugs. The proposed method, rapid and reliable, is recommended for routine use in the clinical laboratory.
Liquid-chromatographic determination of the total thiamin content of blood.
Authors: Kimura M , Fujita T , Itokawa Y 
Published: January 2020

Abstract
A liquid-chromatographic method for determining the total thiamin content of blood is presented. Blood is deproteinized and incubated with Aspergillus oryzae carboxyl proteinase (EC 3.4.23.6; Takadiastase) to convert thiamin phosphate esters to free thiamin. An aliquot of the sample is applied to the column (Shodex OH-Pak M-414) of a high-performance liquid chromatograph. A 100 mg/L solution of potassium ferricyanide in 150 g/L sodium hydroxide is added to the column effluent with a proportioning pump, to convert thiamin into a fluorophore. The intensity of the fluorophore is measured with a spectrofluorophotometer and recorded graphically. The total thiamin in each blood sample appears as a single peak, and no co-eluting substance was detected. This method is simple, highly reproducible, and rapid, and its sensitivity is sufficient for determination of the thiamin content of 0.1-mL blood samples.
Stability of creatine kinase-3 in lyophilized materials.
Authors: Whitner V S , Morin L G , McKneally S S , Sampson E J 
Published: January 2020

Abstract
We examined the stability of creatine kinase (EC 2.7.3.2) isoenzyme-3 (CK-3) in lyophilized bovine albumin matrices in the presence and absence of various sulfhydryl compounds and ADP. We initially purified CK-3 from human myocardium and skeletal muscle by the batch-chromatographic technique and by gradient elution column chromatography to specific activities of 293 and 93 kU/g, respectively. To assess stability, we subjected the lyophilized materials to storage studies at 4, 25, 37, 42, 56, and 65 degrees C and compared first-order rate constants for the decay of creatine kinase activity at 42 degrees C. Our most stable matrix contained, per liter, 2 mmol of ADP and 10 mmol of N-acetylcysteine, and had an extrapolated first-order half-life (Arrhenius plot) at -20 degrees C of approximately 60000 years.
Morphine glucuronide hydrolysis: superiority of beta-glucuronidase from Patella vulgata.
Authors: Combie J , Blake J W , Nugent T E , Tobin T 
Published: January 2020

Abstract
beta-Glucuronidase from Patella vulgata, Helix aspersa, Helix pomatia, and bovine liver were evaluated for usefulness in routine hydrolysis of drug-glucuronic acid conjugates from equine urine samples. Factors affecting the reaction rate (enzyme concentration, ligand concentration, temperature, and pH) were optimized. A 3-h incubation at 65 degrees C with 5000 U of beta-glucuronidase from P. vulgata per milliliter of urine resulted in complete hydrolysis of all morphine glucuronide in the urine samples. Not only was the enzyme preparation from P. vulgata the most cost-effective beta-glucuronidase source studied, but also its thermal stability is such that it can be used at a temperature high enough to substantially shorten the incubation interval. Preliminary work on other drugs that form glucuronide conjugates indicates that this same procedure is similarly superior for use in their hydrolysis.
Interlaboratory surveys of the quantitation of thyroxin and thyrotropin (thyroid-stimulating hormone) in dried blood spot specimens.
Authors: Hearn T L , Hannon W H 
Published: January 2020

Abstract
Screening of newborns for hypothyroidism is mandated by law in most states. The screening usually consists of measuring thyroxin in dried blood spot specimens followed by measurement of thyrotropin if the results for thyroxin are suggestive of hypothyroidism. The first nationwide interlaboratory surveys designed to assess the proficiency of screening laboratories in the identification of euthyroid and hypothyroid specimens are reported here. Each survey consisted of three specimens mailed quarterly from late 1979 through 1980. A total of 88 laboratories participated in at least one of the four surveys. More than 17 different methods or diagnostic kits were used by participants in the surveys. Coefficients of variation ranged from 20% to 41% for thyroxin data and from 23% to 63% for thyrotropin. Despite the large analytical interlaboratory variation, most participants assigned clinical classifications consistent with the survey design. The incidence of mis-classifications was low.
Serum triglycerides determined colorimetrically with an enzyme that produces hydrogen peroxide.
Authors: Fossati P , Prencipe L 
Published: January 2020

Abstract
In this direct colorimetric procedure, serum triglycerides are hydrolyzed by lipase, and the released glycerol is assayed in a reaction catalyzed by glycerol kinase and L-alpha-glycerol-phosphate oxidase in a system that generates hydrogen peroxide. The hydrogen peroxide is monitored in the presence of horseradish peroxidase with 3,5-dichloro-2-hydroxybenzenesulfonic acid/4-aminophenazone as the chromogenic system. The high absorbance of this chromogen system at 510 nm affords useful results with a sample/reagent volume ratio as low as 1:150, and a blank sample measurement is not needed. A single, stable working reagent is used; the reaction is complete in 15 min at room temperature. The standard curve is linear for triglyceride concentrations as great as 13.6 mmol/L. Average analytical recovery of triglycerides in human sera is 100.1%, and within-run and between-run precision studies showed CVs of less than or equal to 1.6 and less than or equal to 3.0%, respectively. The method is suitable for automation.
Multipoint kinetic methods evaluated for quantitation of theophylline with prosthetic group label immunoassay.
Authors: Lin J D , Pardue H L 
Published: January 2020

Abstract
We describe the development and evaluation of a multipoint kinetic approach to the measurement and data-processing steps in immunoassays. Nonlinear regression methods are used to fit data obtained during the kinetic phase of the immunochemical reaction to a model that represents the kinetic behavior of the total system. This approach is evaluated for quantitation of theophylline with a new reaction system in which FAD is the label in a homogeneous reaction system. Competition for antibody binding sites between drug and labeled drug is monitored by the activity of glucose oxidase (EC 1.1.3.4) generated by the reaction of unbound label with apoglucose oxidase. The process is fit well by a parallel first-order/zero-order model and regression methods are used to predict steady-state velocities from non-steady-state portions of the response. One fitting method yields results in about 3 min after mixing, as compared with longer than 8 min for single-point fixed-time methods. Steady-state velocities vary linearly with theophylline concentration.
Improved DEAE-Sephadex column chromatography in measuring amylase in serous ovarian neoplasms, and results for 13 cases.
Authors: Zakowski J J , Bruns D E 
Published: January 2020

Abstract
We describe a column-chromatographic method for measuring amylase activity in cyst fluids of serous ovarian tumors. Using this technique, we confirm and extend the previous report of an "acidic" amylase in serous ovarian tumor cyst fluids. This form of the enzyme was eluted from DEAE-Sephadex mini-columns with a high-salt buffer. It accounted for 45 to 100% of the amylase in 13 cyst fluids. This "high-salt" amylase was also present in the tumor tissues. The acidic nature of the amylase does not appear to be due to sialic acid residues, because the chromatographic behavior of the amylase is unaffected by treatment with neuraminidase. We conclude that the "acidic" amylase reported previously in two serous ovarian tumors is a constant feature of these tumors and that it is distinct from the sialylated tumor amylase described by others.
Lactate dehydrogenase activity as measured by the SMAC is related to flow-cell energy.
Authors: Robertson E A , Wright E , Chesler R A , Elin R J 
Published: January 2020

Abstract
Determination of lactate dehydrogenase (LDH) activity in the SMAC (Technicon) is based on the change in NADH absorbance between two flow cells. We noted that results for patients' specimens and controls changed when the fiber optic terminations for the two LDH channel flow cells were adjusted or "peaked" at the colorimeter chopper assembly. The energy (intensity) of light reaching the flow cells was varied by adjusting the fiber optic terminations, and the absorbance readings for a series of solutions containing NADH and patients' specimens were recorded. For both flow cells, when the fiber optic terminations were adjusted to increase the zero absorbance light intensity from 20 lines to 60 lines, a significant (p less than 0.0001) proportional change was seen in the absorbance readings. Evidently the difference in absorbance between the two flow cells is related not only to the NADH concentrations but also to the difference in the light intensity at the two flow cells. Consequently, changes in the adjustment of the fiber optic terminations produce systematic changes in results for LDH in patients' sera. These systematic changes in LDH results may be minimized by maintaining equivalent settings of the fiber optic terminations for the two flow cells and by using the calibration material with an absorbance most similar to that of patients' specimens.
Turbidimetric immunoassay of serum C-reactive protein.
Authors: Otsuji S , Shibata H , Umeda M 
Published: January 2020

Abstract
This rapid, reliable equilibrium turbidimetric immunoassay for serum C-reactive protein involves a potent monospecific antibody. Polyethylene glycol-6000 to accelerate and enhance the immunoprecipitation reaction, and Tween-20 surfactant to lower and stabilize the sample blank values. Grossly lipemic, icteric, or hemolyzed sera can be assayed. Values up to about 220 mg/L, for which the standard curve is linear, can be measured without sample dilution. Results by the proposed method and by radial immunodiffusion (r 0.989) or laser nephelometry (r = 0.957) correlated well. Analytical recovery averaged 101.3%. Within-, between-, and day-to-day CVs ranged from 0.9% to 3.5%, 0.8% to 5.5%, and 1.9% to 4.8%, respectively. The method is demonstrably superior to radial immunodiffusion or nephelometry. Any spectrophotometer that can measure turbidimetrically at 340 nm can be used.
Interference in a chromogenic alpha-amylase assay caused by dye-labeled oligosaccharide-induced precipitation of lipoprotein.
Authors: Wickus G G , Dukerschein R O , Pierce J R , Davis K D 
Published: January 2020

Abstract
We examined the mechanism by which hypertriglyceridemia interferes with the Roche Diagnostics "Amylochrome" procedure for measurement of amylase in lactescent samples with normal and above-normal amylase activity. The serum blank recommended in the Amylochrome protocol to compensate for lactescence remains inappropriately turbid, compared with the test, and is partly responsible for the underestimation of amylase activity. Other major interference is seen when lipoprotein in hyperlipemic samples with above-normal amylase activity reacts with the soluble oligosaccharide-triazinyl dye product of the Amylochrome assay to form a flocculent blue precipitate. The formation of this precipitate in the test, and its removal, diminish lactescence due to lipemia, an effect that cannot be matched by any manipulation of a serum blank procedure. Oligosaccharide-dye product is removed as a component of the precipitate.