bluuebunny/crossref_metadata_2025_split huggingface dataset:
Carbapenem-Resistant Enterobacterales, Carbapenem Resistant Organisms, Carbapenemase-Producing Enterobacterales, and Carbapenemase-Producing Organisms: Terminology Past its “Sell-By Date” in an Era of New Antibiotics and Regional Carbapenemase Epidemiology
Authors: Livermore David M , Nicolau David P , Hopkins Katie L , Meunier Danièle 
Published: February 2020

Abstract
Carbapenem resistance in Gram-negative bacteria is a public health concern. Consequently, numerous government and agency reports discuss carbapenem-resistant Enterobacterales (CRE) and carbapenem-resistant organisms (CROs). Unfortunately, these terms are fuzzy. Do they include (1) Proteeae with inherent imipenem resistance; (2) porin-deficient Enterobacterales resistant to ertapenem but not other carbapenems; (3) Enterobacterales with OXA-48–like enzymes that remain “carbapenem susceptible” at breakpoint; and (4) Pseudomonas aeruginosa that merely lack porin OprD? Counting CPE or CPOs is better but still insufficient, because different carbapenemases have differing treatment implications, particularly for new β-lactam/β-lactamase inhibitor combinations. At the least, it is essential for authors, journals, and regulatory agencies to specify the carbapenemases meant. The future may demand even greater precision, for mutations can alter hydrolytic activity, and the ability to confer resistance, within carbapenemase families.
An "oncometer" of clinical measurement of colloid osmotic pressure of plasma.
Authors: Bisera J , Weil M H , Michaels S , Bernardo A , Stein B 
Published: February 2020

Abstract
Measurement of colloid osmotic pressure complements measurements of pulmonary artery wedge pressure for assessing the risks of pulmonary edema and constitutes an increasingly important reference for purposes of guiding selection of colloid or crystalloid fluids in patients with acute cardiac disease. We describe a simple device for its routine clinical measurement. A membrane, selectively impermeable to molecules of relative molecular mass (Mr) greater than 30000, is rigidly mounted between a sample chamber and a reference chamber filled with isotonic saline. A pressure transducer measures the negative pressure developed in the reference chamber and displays it on a digital panel meter. The sensor chamber accommodates samples of 50 to 300 microliter. Equilibration is completed within 2 min. A control solution of human serum albumin (50 g/liter) is measured to confirm the accuracy of calibration of the system, with reproducible readings of 25.9 g/cm2 within one SD (equivalent to 0.4 g/cm2). Technical simplicity of operation and modest costs of disposables have made feasible the routine measurement of colloid osmotic pressure.
Monitoring clorazepate dipotassium as desmethyldiazepam in plasma by electron-capture gas--liquid chromatography.
Authors: Haidukewych D , Rodin E A , Davenport R 
Published: February 2020

Abstract
We describe a procedure for determing clorazepate dipotassium as its decarboxylated, pharmacologically active metabolite, desmethyldiazepam, in 100 microL of plasma, with use of electron-capture gas--liquid chromatography and with methylnitrazepam as the internal standard. The procedure is a one-tube, one-step extraction without derivative formation and is accurate, reproducible, and rapid. The sensitivity limit is 20 micrograms/L. Within-run and between-run CV's (concentration, 3.5 mg/L) were 2.9 and 3.5%, respectively. Within-run CV's for 1.5 and 1.0 mg/L concentrations were 3.9 and 4.3%, respectively. For a 1.0 mg/kg per day dose of clorazepate dipotassium, the mean steady-state concentration of desmethyldiazepam in plasma was 1.037 mg/L.
Advantages of using thin sodium iodide detectors for thyroid monitoring of personnel working with 125I.
Authors: Landon S , Smith P G , Staniek S P , Webber C E 
Published: February 2020

Abstract
Measurements of neck count-rates for personnel who regularly iodinated proteins with 125I showed that, generally, count rates were higher after iodination than before. The major pathway for the intake of 125I during iodination was through skin that was exposed to the free-iodine atmosphere of the fume hood. Neck count-rates were measured in 34 other subjects who were working with 125I. The rates for 25 of them were significantly greater than for a control group of 36 subjects. Significant activities were also detected in seven of nine subjects who had never worked directly with 125I but who were located within areas where it was used extensively. To minimize thyroid burdens of 125I, it is essential that neck count-rates be measured routinely, in order to monitor the safety of procedures involving the use of 125I.
Personal and familial factors in cholesterolemia: criteria for selection of a reference population.
Authors: Steinmetz J , Panek E , Siest G 
Published: February 2020

Abstract
We studied factors affecting cholesterolemia in a presumably healthy population of 23 300 subjects, ages 20 to 59 years. Multiple-contingency tables were established, to quantify the information obtained by means of a factorial correspondence analysis. The relations between values for cholesterol and those for triglycerides, uric acid, and overweight were constant for all ages and both sexes. Cholesterolemia paralleled alcohol and tobacco consumption and arterial blood pressure. Use of oral contraceptives did not influence cholesterol values. We classified variation factors according to the statistical method of segmentation, by sex and age. This classification permitted us to establish criteria for excluding subjects from a population sampled with the aim of producing reference values for plasma cholesterol. The values of cholesterol for the 50th percentile were 5.40 mmol/L for men 20 to 39 years old and 5.79 mmol/L for those older than 40. For women, the 50th percentile values increased from 5.34 mmol/L between ages 20 to 39 to 5.92 mmol/L for ages 40 to 49 and to 6.51 mmol/L after 50.
3-hydroxydecanedioic acid and related homologues: urinary metabolites in ketoacidosis.
Authors: Greter J , Lindstedt S , Seeman H , Steen G 
Published: February 2020

Abstract
Urine from patients with ketoacidosis was found to contain a number of aliphatic 3-hydroxy dicarboxylic acids. The acids were purified by silicic acid chromatography and their structures determined by gas chromatography-mass spectrometry of different derivatives. The major compound was 3-hydroxydecanedioic acid. Minor compounds were 3-hydroxyoctanedioic acid, 3-hydroxyoctenedioic acid, 3-hydroxydecenedioic acid, 3-hydroxydodecanedioic acid, 3-hydroxydodecenedioic acid, 3-hydroxytetradecenedioic acid, and 3-hydroxytetradecadienedioic acid. The excretion of 3-hydroxydecanedioic acid correlated positively with the excretion of hexanedioic acid, another metabolite constantly found in ketoacidosis (Pettersen et al., Clin. Chim. Acta 38: 17-24, 1972). We suggest that the 3-hydroxy dicarboxylic acids are formed from fatty acids by a combination of omega-oxidation and incomplete beta-oxidation.
Adaptation of the enzyme-multiplied immunoassay for methotrexate to the centrifugal analyzer.
Authors: Finley P R , Williams R J , Griffith F , Lichti D A 
Published: February 2020

Abstract
We adapted the homogeneous enzyme-multiplied immunoassay for methotrexate to the centrifugal analyzer. The sensitivity of the assay has been extended from 200 nmol/L down to 12.5 nmol/L. Several protocols may be followed, depending on whether the samples to be tested are from patients on low- or high-dose methotrexate regimens. Precision, accuracy, and sensitivity were satisfactory. Comparison with the enzymic-inhibition method (x) gave the following least-squares regression: y = 1.002 x - 0.013 mumol/L; r2 = 0.9721; Sy/x = 0.014 mumol/L.
Two agarose electrophoretic systems for demonstration of oligoclonal bands in cerebrospinal fluid compared.
Authors: Gerson B , Krolikowski F J , Gerson I M 
Published: February 2020

Abstract
Demonstration of oligoclonal bands by electrophoresis of cerebrospinal fluid is an important aid in establishing the diagnosis of multiple sclerosis. Electrophoretic systems vary in their effectiveness in doing so. We compared two systems in this respect. For a thin-layer agarose system, sensitivity was less (47%) than for a high-resolution agarose system (87%). Each system had good specificity (92 and 85%, respectively). Interpretation of electrophoretic patterns for cerebrospinal fluid should be available in clinical laboratories. Further, the best available system should be used for demonstration of oligoclonal bands.
Acid phosphatase in Gaucher's disease.
Authors: Robinson D B , Glew R H 
Published: February 2020

Abstract
Increased acid phosphatase activity in the serum and tissues of patients with Gaucher's disease has now been recognized for two decades, but as yet no relation has been established between the enzyme and the etiology and progress of the disease. Here, we review results obtained by various investigators, ranging from a consideration of the methods used for the evaluation of serum acid phosphatase in Gaucher's disease to the most recent findings regarding the purification and characterization of two acid phosphatase isoenzymes from the spleen from patients with Gaucher's disease. We also discuss the intracellular location of tissue acid phosphatase in patients with Gaucher's disease and its contribution to the increased activity in serum.
Prostate-specific acid phosphatase: re-evaluation of radioimmunoassay in diagnosing prostatic disease.
Authors: Griffiths J C 
Published: February 2020

Abstract
The availability of a radioimmunoassay for prostate-specific acid phosphatase has allowed a correlative study between this technique and conventional colorimetric assays in the four clinical stages of prostatic adenocarcinoma. Results of such a study show an increased diagnostic sensitivity of the radioimmunoassay in all stages, but in 14% of Stage IV adenocarcinomas there was no increase in prostatic acid phosphatase above the ranges ordinarily expected for all methods. In cases of benign prostatic hyperplasia, there was an increase associated with in vivo tissue cytolysis, comparable to Stage II and III adenocarcinoma. The sensitivity of the test in Stage I is still low, but testing for combinations of tumor markers might increase the diagnostic yield. Conversely, a different clinical approach might be to establish baseline values in the "at-risk" patient, followed by regular determinations of prostate-specific acid phosphatase activity. Increases in activity within the normal expected range may be interpreted by the clinician as a herald of disease.
Further heterogeneity demonstrated for serum creatine kinase isoenzyme MM.
Authors: Chapelle J P , Heusghem C 
Published: February 2020

Abstract
Serum creatine kinase (EC 2.1.3.2) isoenzyme MM was resolved by isoelectric focusing into a five-band pattern, a pattern that gradually changed after the onset of myocardial infarction. Similar changes were also demonstrated in patients undergoing coronary-bypass surgery. The evolution of two CK-MB sub-bands was studied in both cases. We found that three electrophoretic bands (CK-MM, pI 7.10; MM1, pI 6.88; MB1, pI 5.61) were predominant in patterns for sera collected during the early phase of myocardial infarction, but rapidly disappeared during the following hours, whereas bands of increased electrophoretic mobility (MM2, pI 6.70; MM3, pI 6.45; MM4, pI 6.25; MB2, pI 5.34) gradually increased. MM3 was always the major band at the end of the observation period in acute myocardial infarction (mean, 61.4% of total creatine kinase activity 36 h after the peak value for total creatine kinase in serum). The CK-MM bands were also present in the serum of patients without heart disease. Changes in the electrophoretic pattern were induced by a thermolabile factor in normal human serum, which transformed the muscular or myocardial MM and MM1 bands after their release into the blood stream.
Accuracy, precision, and stability in measurement of hemoglobin A1C by "high-performance" cation-exchange chromatography.
Authors: Schifreen R S , Hickingbotham J M , Bowers G N 
Published: February 2020

Abstract
We present a "high-performance" liquid-chromatographic method for determination of HbA1c with use of a carboxylate cation-exchange column, ethanolic mobile phases, and a hemolysate-storage reagent that stabilizes a sample for up to five weeks at 4 degrees C. Temperature control and the addition of ethanol to the phosphate step-gradient increase precision by stabilizing peak shape and column activity. Lengthy equilibration of the column between samples is not necessary, because the pKa of the cation-exchange resin is decreased from 6.10 in aqueous media to 5.59 in ethanol/water (5/95 by vol) at 25 degrees C. We identified interfering heme compounds, distinct from HbA1d or HbA1e, that elute with the glycosylated hemoglobins and developed a method of correcting for their presence. The day-to-day coefficient of variation was 3.5%, and the reference interval for a mixed group of 20 healthy adults between the ages of 20 and 56 was 3.2—5.2% HbA1c.
Conditions affecting the colorimetry of orotic acid and orotidine in urine.
Authors: Harris M L , Oberholzer V G 
Published: February 2020

Abstract
We studied conditions affecting a colorimetric assay of total orotic acid (orotic acid plus orotidine) in urine. Most interfering substances can be conveniently removed on a small column of cation-exchange resin, and an improved control reaction corrects for residual background color. Analytical recovery from urine is nearly complete (greater than 95%) and the absorption spectrum for analyte eluted from the column closely resembles that for an orotic acid standard. We determined reference intervals for total orotic acid, expressed as a molar ratio to creatinine, for neonates, children, and adults, and assessed the effect of age, protein intake, and pregnancy. The method is simple enough to use as a reliable and accurate urine-screening test.
Binding of IgG and other proteins to microfilters.
Authors: Walsh R L , Coles M E 
Published: February 2020

Abstract
We evaluated 10 microfilters for their ability to filter diluted sera without removing immunoglobulins (Ig) G, A, and M, albumin, and transferrin. In general, filters containing cellulose nitrate remove IgG from solution, the amount adsorbed being proportional to the IgG concentration in the solution. With some sera we noted IgA and IgM adsorption to cellulose-nitrate-containing filters, but there was no significant adsorption of albumin or transferrin to any of the filters. We also found that cellulose-nitrate filters adsorbed IgG from antiserum, with consequent loss of titre as seen in a nephelometric assay. Adsorption of IgG was not seen if the filters were prewashed with polyethylene glycol or if the antisera contained polyethylene glycol. With a sufficiently large antibody excess in the nephelometric assay, this loss of titre through filtration becomes undetectable.
Commercially-supplied binders for plasma cobalamin (vitamin B12), analysis--"purified" intrinsic factor, “cobinamide"-blocked R-protein binder, and non-purified intrinsic factor-R-protein binder--compared to microbiological assay.
Authors: Kubasik N P , Ricotta M , Sine H E 
Published: February 2020

Abstract
Recent evidence (Kolhouse et al., N. Engl. J. Med. 299: 785–792, 1978) demonstrates that commercial cobalamin (Vitamin B12) radioassay kits contain nonspecific R-protein binding agents that can give falsely normal results in patients who are actually cobalamin deficient. We tested three kits: with “purified” intrinsic factor as the binder, with intrinsic factor and the nonspecific R-protein sites blocked with “cobinamide,” and non-purified intrinsic factor-R-protein binder. Results with use of the first two compared well with those by a microbiological assay (Lactobacillus leichmannii) and are in harmony with clinical impressions.
Ion effects in measurement of ionized calcium with a calcium-selective electrode.
Authors: Kaufman R A , Tietz N W 
Published: February 2020

Abstract
We examined the performance characteristics of an improved electrode for measurement of ionized calcium (Orion Research, Inc.) with respect to interferences by Na+, K+, Li+, Mg2+, and H+, as well as the effect of changes in ionic strength and osmolality. At physiologically observed concentrations, all ions except Na+ insignificantly affected ionized-calcium measurements. The decrease in ionized Ca2+ with increased Na+ concentration is caused by the increase in ionic strength and the associated decrease in Ca2+ activity. Sodium had no significant direct effect in concentrations below 250 mmol/L. A previously published (Clin. Chem. 23: 690, 1977) equation for the Na+ correction is invalid for this improved electrode. Changes in osmotic pressure negligibly affect electrode response. Significant changes in ionic strength, as would be observed in severe hypo- and hypernatremic sera, increase or decrease, respectively, values for ionized calcium by changing Ca2+ activity. With aqueous Ca2+ solutions, changes of less than or equal to 3% were observed for Na+ concentrations that deviate from 140 mmol/L by not more than 20 mmol/L. Because the calcium ion activity is considered to be the physiologically important variable, we suggest that no correlation be made for ionic strength effects.
Albumin-bound fluorescence in serum of patients with chronic renal failure.
Authors: Schwertner H A , Hawthorne S B 
Published: February 2020

Abstract
A band that is strongly fluorescent and migrates electrophoretically with serum albumin is commonly found in electrophoretograms of sera from patients with chronic renal failure. We sought to determine whether the fluorescence originates from binding of certain still-unidentified metabolites or drugs, from an abnormal albumin species, or from some other protein entity. Molecular-exclusion column chromatography, polyacrylamide gel isoelectric focusing, and cellulose acetate electrophoresis, along with results of charcoal treatment and alcohol extraction, provided evidence that the fluorescence comes from fluorescent ligands tightly bound to albumin. The fluorescent intensity of the albumin fraction, isolated by molecular-exclusion chromatography, coincides with the albumin-associated fluorescence determined electrophoretically and with the intensities of the fluorescence emission spectrum for serum. A fluorescent species with an emission maximum of 415 ± 5 nm, separated by thin-layer chromatography, appears to account for the increased serum fluorescence.
High-purity 4-nitrophenol: purification, characterization, and specifications for use as a spectrophotometric reference material.
Authors: Bowers G N , McComb R B , Christensen R G , Schaffer R 
Published: February 2020

Abstract
We describe specifications for high-purity 4-nitrophenol, which is suitable for spectrophotometric standardization. Such a reference material is needed in clinical enzymology to establish the proper molar absorptivity of 4-nitrophenol under final reaction conditions, particularly for measuring alkaline phosphatase activity in human serum. Some lots of 4-nitrophenol available commercially met these specifications, but several did not. The latter can be purified to meet our specifications by recrystallization or sublimation. The molar absorptivity of 4-nitrophenol (35 μmol/L) IN 10 mmol/L NaOH at 25 °C at 401 nm is 18380 +/− 90 L.mol−1.cm−1.
Plasma methotrexate as determined by liquid chromatography, enzyme-inhibition assay, and radioimmunoassay after high-dose infusion.
Authors: Howell S K , Wang Y M , Hosoya R , Sutow W W 
Published: February 2020

Abstract
Three techniques for measuring methotrexate show various cross reactivities with methotrexate-related compounds: “high-pressure” liquid chromatography, by principle, is virtually specific for methotrexate; the enzyme-inhibition assay quantitates methotrexate, methotrexate diglutamate, and methotrexate triglutamate equally well, but has a 10% cross reactivity with 4-amino-4-deoxy-N10-methylpteroic acid and 1% with 7-hydroxymethotrexate; radioimmunoassay shows an equal cross reactivity with methotrexate, 4-amino-4-deoxy-N10-methylpteroic acid, methotrexate diglutamate and triglutamate, and a 5 to 10% cross reactivity with 7-hydroxymethotrexate. Radioimmunoassay almost always yielded the highest values for methotrexate, followed by enzyme-inhibition assay then liquid chromatography. The presence of two methotrexate-related compounds, 7-hydroxymethotrexate and 4-amino-4-deoxy-N10-methylpteroic acid, was confirmed in human urine samples and quantitated in patients’ plasma by liquid chromatography, the respective maximum plasma concentrations being 250 and 16 mumol/L. Materials cross reacting with methotrexate in radioimmunoassay of chromatographic fractions from plasma were also noted in fractions corresponding to methotrexate diglutamate and triglutamate peaks, in quantities estimated to be 47 and 30 nmol/L methotrexate equivalents, respectively. 7-Hydroxymethotrexate is eliminated more slowly than methotrexate and its production increases with dosages of methotrexate.
Bilirubin binding capacity of albumin isolated from cord-blood serum is less than that from serum of adults.
Authors: Alayoff A , Kapitulnik J , Konijn A , Kaufmann N A , Blondheim S H 
Published: February 2020

Abstract
As estimated by Sephadex gel filtration, the bilirubin binding capacity of albumin isolated from cord-blood serum by ion-exchange chromatography is less than that of albumin isolated from serum of adults. Albumin isolated from cord-blood serum showed increased bilirubin binding as compared with the albumin in the native serum. These findings suggest that the lower bilirubin binding capacity of serum from newborns as compared with serum from adults is a result of both an intrinsic deficiency in binding capacity of neonatal albumin and the presence of substances in neonatal serum that interfere with bilirubin binding.
Isoenzymes of creatine kinase in extracts of various parts and regions of the human central nervous system.
Authors: Petronia R R , Maas A H , van Veelen C W , Staal G E 
Published: February 2020

Abstract
The distribution of isoenzymes of creatine kinase (EC 2.7.3.2.) was investigated by agarose gel electrophoresis of extracts of selected parts and regions of the human central nervous system. Besides the major brain isoenzyme BB, we demonstrated the presence of three other creatine kinase isoenzyme forms. The distribution of creatine kinase isoenzymes depending strongly on the region from which the biopsy was taken. We found substantial amounts of the MB isoenzyme in extracts of the dura from the cauda equina of the two adults examined.
Simplified approach to confidence limited in radioimmunassay.
Authors: Baxter R C 
Published: February 2020

Abstract
A simple method of calculating confidence limits for radioimmunoassay data is presented. The method involves the use of the within-assay variation in dose estimate of three routine quality-control specimens, measured in repeated assays, to estimate the confidence limits for results on unknown samples. Results for control specimens are combined by calculating the unique quadratic curve fitting a graph of within-assay standard deviation vs mean value for each control. This method requires no special data accumulation or advanced computing equipment. For cortisol, lutropin, and thyroxine radioimmunoassays, confidence limits calculated in this way have been compared with those calculated from the variance of the response variable “B/B0” in repeated standard curves. Both methods agree well with actual limits observed when plasma pools containing a wide range of hormone concentrations are assayed repeatedly.