bluuebunny/crossref_metadata_2025_split huggingface dataset:
Use of L-leucyl-3-carboxy-4-hydroxyanilide as substrate for determining the activity of microsomal aminopeptidase in serum.
Authors: Shimamoto M , Takewaki S , Sakuraoka S , Nagasawa T , Kuroiwa K , Kodama O , Akatsuka T 
Published: January 2020

Abstract
We describe a colorimetric method for assay of microsomal aminopeptidase (EC 3.4.11.2) activity in serum. We use a new substrate, L-leucyl-3-carboxy-4-hydroxyanilide, p-xylenol as coupler, and sodium metaperiodate as oxidizing reagent. The colored substance formed by the oxidative condensation between p-xylenol and 5-aminosalicylic acid absorbs maximally at 635 nm, and can be directly measured in serum. In a previous method for this enzyme, L-leucyl-beta-naphthylamide was used as substrate and beta-naphthylamine, a carcinogenic reagent used as a standard in making the assay, was unsuitable for routine use. We found a close correlation between results obtained with the new, safer method and with the previous method.
A case of partial deficiency of alpha 1-antichymotrypsin.
Authors: Lorier M A , Hawes C , Donaldson I M , George P M 
Published: January 2020

Abstract
A 20-year-old woman, admitted to a neurological ward with a diagnosis of benign intracranial hypertension, was found on specific protein electroimmunoassay to have a consistently decreased concentration of alpha 1-antichymotrypsin in her plasma. Serum from her father showed the same result. Further investigation of her family demonstrated that this partial deficiency was transmitted in an autosomal dominant fashion and was not associated with any obvious specific clinical abnormalities.
Candidate reference method for determination of total bilirubin in serum: development and validation.
Authors: Doumas B T , Kwok-Cheung P P , Perry B W , Jendrzejczak B , McComb R B , Schaffer R , Hause L L 
Published: January 2020

Abstract
This candidate Reference Method for measuring total bilirubin in serum is based on the Jendrassik-Gróf principle (Clin Chem 29: 297-301, 1983). Standard Reference Material no. 916 bilirubin (National Bureau of Standards) is used as the standard. Bilirubin standard solutions may be prepared either in human serum or in 40 g/L albumin solution (human or bovine), because we found the molar absorptivity of the azopigment at 598 nm to be identical in these media. The absorptivities of the unconjugated and conjugated azopigments appear to be identical, but the conjugated azopigment is completely hydrolyzed in the final reaction mixture. Bilirubin added to serum from adults or neonates was quantitatively accounted for. Interference by hemoglobin (up to 2 g/L), ascorbic acid (up to 20 mg/L), or zinc (at physiological concentrations) is negligible. Of the therapeutic drugs we tested, only L-dopa and alpha-methyldopa interfere. We established normal adult reference values for total bilirubin and examined the intraindividual variation in 19 subjects.
Simultaneous determination of epinephrine and norepinephrine in urine by derivative synchronous fluorescence spectroscopy.
Authors: Valcárcel M , Gómez-Hens A , Rubio S 
Published: January 2020

Abstract
The combination of synchronous and derivative fluorimetry, potentially useful in resolving mixtures that present strongly overlapping conventional fluorescence spectra, appears suitable for determining epinephrine and norepinephrine in urine. We describe a simple, rapid, and inexpensive method for simultaneous assay of these compounds in a single scan of urine specimens from normal adults. The catecholamines are extracted from the sample on cation-exchange columns and subsequently determined by formation of trihydroxyindoles. Analytical recovery is about 94% for epinephrine, 91% for norepinephrine, with a CV of approximately 5%. No sophisticated detection equipment is necessary, a conventional modern fluorimeter being adequate.
Sodium activity, sodium concentration, and osmolality in plasma in acute and chronic renal failure.
Authors: Langhoff E , Ladefoged J 
Published: January 2020

Abstract
We compared the ionic activity of sodium, as measured with glass electrodes, with sodium concentration in 23 healthy persons, 15 persons with acute renal failure, and before and after dialysis in 46 patients with chronic renal failure. In healthy persons the mean (+/- SEM) sodium concentration was 139.1 +/- 0.6 mmol/L, whereas the ionic activity was equal to that of a 145.2 +/- 0.5 mmol/L solution of sodium chloride. Variation in the concentration of plasma protein was the most important factor influencing the sodium activity coefficient (the ratio between activity and concentration). The sodium activity coefficient in plasma water (corrected for the non-aqueous phase of the plasma) was fairly constant, being 96% of that in a 140 mmol/L solution of sodium chloride. Thus sodium binds to non-protein molecules and sodium ions interact with other substances in uremic plasma only to a very limited extent. The sum of the molar activities of sodium, potassium, urea, and creatinine was closely and linearly correlated with plasma osmolality, both before and after dialysis.
Multiple markers of malignancy in sera of patients with colorectal carcinoma: preliminary clinical studies.
Authors: Mercer D W , Talamo T S 
Published: January 2020

Abstract
Eleven potential biochemical markers were measured in serum from 33 patients with malignant and 13 with benign colorectal disease: four isoenzymes (creatine kinase-BB, homoarginine-sensitive alkaline phosphatase, salivary-type amylase, and macro-creatine kinase type 2), five specific proteins (ferritin, alpha 1-acid glycoprotein, C-reactive protein, alpha 1-antitrypsin, and ceruloplasmin), one oncofetal antigen (carcinoembryonic antigen, CEA), and one hormone (beta human choriogonadotropin). The sensitivity of individual markers for the detection of early-stage malignancy (n = 11) ranged from 0% to 64% (CEA 18%); for late-stage colon malignancy (n = 12) from 8% to 83% (CEA 83%). Specificity in patients (n = 10) with benign intestinal disease ranged from 80% to 100% (CEA 100%). The five most-sensitive markers--C-reactive protein, alpha 1-glycoprotein, CEA, macrocreatine kinase type 2, and homoarginine-sensitive alkaline phosphatase--were selected for use as a "colon panel." In retrospective comparison, use of the colon panel instead of CEA alone increased sensitivity by 17% and 64% for late-and early-stage cancer, respectively; specificity, however, decreased by 30%, but should improve with serial testing.
Facile radioimmunoassay of estradiol 3-sulfate in plasma during pregnancy.
Authors: Tanaka T , Suguro N , Kubodera A 
Published: January 2020

Abstract
A facile, sensitive radioimmunoassay of estradiol 3-sulfate in pregnancy plasma was established. Highly specific antisera were raised in male rabbits against a conjugate of 6-oxoestradiol 3-sulfate-(O-carboxymethyl)oxime with bovine serum albumin. After purification of the antiserum, we coupled the crude globulin fraction to CNBr-activated Sepharose-4B and used this for direct radioimmunoassay of estradiol 3-sulfate in plasma without sample pre-treatment such as solvent-extraction or chromatography to remove endogenous interferences. Using this assay system, we determined concentrations of estradiol 3-sulfate in plasma from pregnant women. Concentrations of estradiol 3-sulfate in plasma increased in proportion to those of estradiol throughout gestation, but were about twice as high as those of unconjugated estradiol at each week of pregnancy.
A whole-cell assay for glucocorticoid binding sites in normal human lymphocytes.
Authors: Steiner A E , Wittliff J L 
Published: January 2020

Abstract
We established a whole-cell assay in the clinical laboratory, using normal human lymphocytes isolated from peripheral blood. [3H]Dexamethasone binding reached a maximum after 90 min at 24 degrees C. Dissociation constants (Kd) were determined to be 1 X 10(-9) mol/L. Specific glucocorticoid-binding capacities of 3 to 23 fmol/10(6) cells, or 1800 to 13 800 sites/cell, were observed. Steroids with glucocorticoid activity such as triamcinolone acetonide and cortisol effectively competed for [3H]dexamethasone binding sites, whereas those with no glucocorticoid potency such as estradiol-17 beta and testosterone showed little inhibition. Studies on the cellular distribution of [3H]dexamethasone indicated that 23% was bound to the cytosol, 77% to the cell nucleus. The whole-cell assay is easily adaptable for the clinical laboratory assessment of glucocorticoid receptors in normal and malignant lymphocytes, and may be useful in evaluating the activity-function relationships of potential therapeutic agents.
Liquid-chromatographic assay of dexamethasone in plasma.
Authors: Plezia P M , Berens P L 
Published: January 2020

Abstract
We report a simple, efficient method for removing dexamethasone from plasma by use of solid-phase extraction columns. The dexamethasone is then quantified by "high-performance" liquid chromatography with ultraviolet detection at 254 nm. Dexamethasone concentrations and peak-height ratios were linearly related over the range 5 to 200 micrograms/L. The lower limit of sensitivity was 5 micrograms/L. The average recoveries of dexamethasone and methylprednisolone (internal standard) were 72 and 71%, respectively. This procedure offers improved efficiency over that of previously described methods by decreasing analytical time and improving sample clean-up. Sensitive, specific, and relatively inexpensive, this method is suitable for most clinical applications.
Macro creatine kinase type 2: results of a prospective study in hospitalized patients.
Authors: Stein W , Bohner J , Renn W , Maulbetsch R 
Published: January 2020

Abstract
We determined total CK activity with the N-acetylcysteine-activated method and residual activity after immunoinhibition of the CK-M subunits in the sera of 2018 patients consecutively admitted to our university hospital for internal diseases, and of 936 outpatients, regardless of the patients' diagnoses. We could detect not more than two types of macro CK: macro CK type 2, which we observed in the sera of 85 patients (prevalence, 3.7% for hospitalized patients), and macro CK type 1. Most patients showing macro CK type 2 were older than 50 years, but we additionally observed a second peak at 20-30 years of age. We saw no preponderance by sex. We detected macro CK type 2 predominantly in severely ill patients of all ages, mainly those with malignant tumors or cirrhosis of the liver. Our findings support the assumption that macro CK type 2 is the manifestation of mitochondrial CK in serum. Occasionally, macro CK type 2 disappeared from the circulation after amelioration of the associated disease. Its occurrence in serum nevertheless is a sign of a serious illness with high mortality but not inevitably a sign of impending death.
Biosynthesized [35S]methionine-labeled pro-opiomelanocortin peptides as novel recovery markers in radioimmunoassay of peptide hormones.
Authors: Rosendale B E , Jarrett D B 
Published: January 2020

Abstract
Hormones are extracted from plasma with varying efficiency. Thus, markers or internal standards are often needed, to monitor and correct for extraction losses. To do so is difficult in the case of peptide hormones because radioactive recovery markers either have a low specific activity or, if labeled with iodine, may not be fully representative because of alterations in their size and charge. More importantly, markers labeled with 125I can interact in, and thus compromise, the subsequent radioimmunoassay. AtT-20 mouse pituitary tumor cells, which can be stimulated to synthesize and secrete pro-opiomelanocortin peptides, can biosynthetically label beta-lipotropin (beta-LPH) with [35S]methionine. The labeled peptide, which is co-eluted with unlabeled beta-LPH in "high-performance" liquid chromatography, is fully immunoprecipitable and has a specific activity of 34 Ci/g. We use this labeled peptide to monitor the recovery of beta-LPH in silicic acid extraction from plasma. This peptide is an ideal marker of analytical recovery because it does not interfere in subsequent radioimmunoassays.
Methods for studying the binding of aluminum by serum protein.
Authors: Rahman H , Skillen A W , Channon S M , Ward M K , Kerr D N 
Published: January 2020

Abstract
We describe methods for studying the binding of Al by protein in serum: ultrafiltration, gel filtration, and immuno-affinity chromatography. For ultrafiltration we used an Amicon YM10 cellophane membrane with a nominal cutoff of 10 000 Da to separate ultrafiltrable and non-ultrafiltrable Al. For gel filtration we used Sephacryl S-300, and for immuno-affinity chromatography we used anti-transferrin coupled to CNBr-activated Sepharose to identify the Al-binding protein. For 30 normal subjects 54% of the total Al in serum was non-ultrafiltrable; for 30 patients with chronic renal failure being treated by hemodialysis 67% was non-ultrafiltrable. In both groups transferrin was identified as the major Al-binding protein in the serum. Results of gel-filtration studies should be interpreted with caution: some gel media adsorb "free" Al, which can be subsequently taken up by transferrin or desferrioxamine passing through the column. We find affinity chromatography to be a specific and reliable method, suitable for use in quantitative studies.
Improved reference-interval estimation.
Authors: Shultz E K , Willard K E , Rich S S , Connelly D P , Critchfield G C 
Published: January 2020

Abstract
We used two standard methods (the common percentile and the log-power gaussian transformation) and two novel methods (weighted percentile and smoothed spline interpolation) to estimate the 2.5th and 97.5th percentiles of 1000 sets of data from eight diverse distributional forms, generated by Monte Carlo simulation. For each distributional form we derived an estimate of optimal performance. Although none of the four proposed methods closely approximated the optimal performance bound, the spline interpolation method and the weighted percentile method were superior to the two standard methods in accurately estimating percentiles.
Rapid analysis for methylglyoxal bis(guanylhydrazone) by reversed-phase ion-pair liquid chromatography.
Authors: Gildersleeve D L , Tobes M C , Natale R B 
Published: January 2020

Abstract
We describe a "high-performance" reversed-phase ion-pair liquid-chromatographic procedure for measuring methylglyoxal bis(guanylhydrazone) (MGBG) in plasma, urine, and bone-marrow leukocytes. Specimens of plasma and bone-marrow leukocytes are deproteinized with perchloric acid, then neutralized with KOH. Urinary MGBG is isolated by liquid-solid extraction in a C18 Sep-Pak. The chromatographic system consists of a 45 X 4.6 mm (i.d.) octadecylsilyl (C18, 5-microns particle) column and a mobile phase consisting of methanol/sodium acetate buffer (200 mmol/L, pH 4.5), 2/3, by vol. The acetate buffer also contains 20 mmol of 1-octanesulfonate and 40 mg of sodium azide per liter. The column effluent is monitored at 283 nm. At a flow rate of 3.0 mL/min, MGBG is eluted in 1.67 min. The detection limit is 20 nmol/L, and peak height varies linearly with concentration from 0.02 to 40 mumol/L. Analytical recovery exceeds 99%. Within-day CVs ranged from 0.9% to 2.9%, between-day CVs from 4.2% to 6.2%.
Plasma apolipoprotein pattern in fish-eye disease examined by high-resolution two-dimensional electrophoresis.
Authors: Marshall T , Williams K M , Holmquist L , Carlson L A , Vesterberg O 
Published: January 2020

Abstract
We compared the plasma protein patterns of the two living patients suffering from fish-eye disease with those of appropriate controls, using high-resolution two-dimensional electrophoresis. Quantitative abnormalities were detected in plasma polypeptides corresponding to the isoforms of apolipoproteins A-I and A-II. The disease was characterized by normal concentrations of proapo A-I but dramatically subnormal concentrations of the other apo A-I isoforms and apo A-II. No significant difference was detected in the concentrations of other plasma proteins. These findings are discussed in relation to other apolipoprotein disorders.
Comparison of improved precipitation methods for quantification of high-density lipoprotein cholesterol.
Authors: Warnick G R , Nguyen T , Albers A A 
Published: January 2020

Abstract
We compared the standard Lipid Research Clinics heparin-Mn2+ (46 mmol/L) method and five improved precipitation methods for quantification of high-density lipoprotein (HDL) cholesterol. Three of these methods--a dextran sulfate-Mg2+ procedure, reported as a Selected Method, a modified heparin-Mn2+ (92 mmol/L) method, and a modified phosphotungstate-Mg2+ procedure--all gave similar results. Three other methods--the standard heparin-Mn2+ (46 mmol/L) method and two polyethylene glycol methods (75 g/L or pH 10 reagent at 100 g/L final concentrations)--gave slightly higher values for HDL cholesterol. Addition of NaCl or glucose to specimens did not significantly change protein precipitation. In terms of sedimentation effectiveness with hypertriglyceridemic specimens, the methods were ranked in the following order: polyethylene glycol (pH 10, 100 g/L) greater than dextran sulfate-Mg2+ greater than heparin-Mn2+ (92 mmol/L) = polyethylene glycol (75 g/L) greater than phosphotungstate-Mg2+ greater than heparin-Mn2+ (46 mmol/L).
A sensitive high-temperature electrothermal atomic absorption analysis for Rb+ in erythrocytes and plasma of normal and hypertensive persons.
Authors: Hallis K F , Boon N A , Perkins C M , Aronson J K , Grahame-Smith D G 
Published: January 2020

Abstract
This method for determination of Rb+ in human plasma and erythrocytes by graphite-furnace atomic absorption spectrophotometry has a sensitivity of 29 nmol/L for plasma, 12 nmol/L for erythrocytes. The detection limit is 24 nmol/L for plasma, 4.8 nmol/L for erythrocytes. This assay is approximately 30-fold more sensitive than previously reported techniques involving atomic absorption spectrophotometry, enabling use of smaller samples. The rubidium signal is linear with concentration up to 1.2 mumol/L, and addition of other cations to the matrix produces only minor alterations in the Rb+ signal. We measured plasma and erythrocytic Rb+ concentrations in healthy subjects and in patients with untreated essential hypertension. In both, our values are similar to those previously reported for healthy individuals.
Collection and Handling of 24-Hour Urine Specimens for Measurement of Analytes Related to Renal Calculi
Authors: Ng Ronald H , Menon Mani , Ladenson Jack H 
Published: January 2020

Abstract
Vol. 30
p 468: In line 7, left column, HCl should be 12 mol/L.
p 536: In Figs. 4 and 5, change the unit on the ordinates to "%." Change the ordinate numbers on Fig. 4 from 0, 20, 40, 60, 80, and 100 to 0, 5, 10, 15, 20, 25. On Fig. 5, change the ordinate number from 120 to 30.
p 725: In line 8, right column, change "logarithmic probability," to "probit." In Figs. 2 and 3, replace the terms "log 10" and "double log" by "probit" and "simple log," respectively.
p 729: Insert "γ" in the empty space on line 23, right-hand column, so the expression reads "100(1 – γ)%."
pp 856–7: Exchange the legends for Figures 2 and 3.
p 1111: Units in the left-hand Table should be "µg/L," not "g/L."
p 1260: In the first column, just under equation 2, delete "β" and insert the words "for a."
p 1294: In paragraph three, line 6, for "blunted" read "blunt."
p 1353: Transpose Figures 2 and 3 over the (unchanged) legends.
0.53 1.02 2.71 5.0
p 1364: The sixth line of data, columns 2–4 should read "176.4 ± 43," "470 ± 198," and "0.5." The final line of data, columns 2–4, should read "1.95 ± 0.47," "5.05 ± 2.12," and "0.4," and, under "Range" the following should be inserted at the bottom of the column:
0.4–0.7
0.2–0.8
0.1–0.7.
p 1365: The data in columns 2 and 4, and some in column 3, of Table 3 should read:
See table in the PDF file
p 1429: The middle column, next to last paragraph, should read: "Hb 27 g/L" and "leukocytes 186 x 109/L."
p 1812: Column 1, fifth line of text: change "decreasing" to "increasing."
p 1813: Column 2, x refers to whole blood rather than plasma, y to plasma.
Pharmacokinetic analysis of a case of isopropanol intoxication.
Authors: Natowicz M , Donahue J , Gorman L , Kane M , McKissick J , Shaw L 
Published: January 2020

Abstract
A comatose 46-year-old woman, admitted to the emergency room, had isopropanol and acetone concentrations of 2000 and 120 mg/L, respectively, in her serum. She had no known history of acute isopropanol intoxication and was otherwise physically healthy. Pharmacokinetic analysis showed that the elimination of both isopropanol and its major metabolite acetone obeyed apparent first-order kinetics with half-lives of 6.4 and 22.4 h, respectively. These data contrast with the commonly held view that isopropanol is slowly metabolized. Concentrations of these analytes in cerebrospinal fluid 6 h after admission were similar to those in serum. This is the first report of the pharmacokinetics of both agents in a nonalcoholic person, and it gives the first data on concentrations of these substances in cerebrospinal fluid.
Fluoroimmunoassays and immunofluorometric assays.
Authors: Hemmilä I 
Published: January 2020

Abstract
Fluorescent probes and fluorometric methods have gained increasing interest in the field of clinical immunology, not only as one additional alternative to radioimmunoassays, but also in producing cheap, stable, and safe reagents and rapid and sensitive assays. One of the main goals has been the development of homogeneous assays: assays based on fluorescence polarization, fluorescence quenching, excitation transfer, or enzymically releasable probes are widely applied, especially in drug monitoring. The development of suitable solid-phase separation techniques has facilitated utilization of fluorescence in heterogeneous assays, which in general have wider applications, from proteins and viruses to small haptens. Lately new alternative fluorescent probes and methods have been introduced. For example, the use of fluorescent phycobiliproteins or porphyrin derivatives with long-wavelength emission and large Stokes shift or, in particular, the rare earth chelates with unique fluorescent properties well suited to time-resolved measurement have opened new possibilities towards more sensitive immunoassays.
Radioimmunoassay for arylsulfatase A in urine.
Authors: Laidler P M , Ryder K W , Glick M R , Oei T O , Van Etten R L 
Published: January 2020

Abstract
Purified arylsulfatase A (EC 3.1.6.1) from human urine was radioiodinated under conditions that caused no significant loss of antigenic activity. We used this labeled arylsulfatase A (specific radioactivity 4-7.5 Ci/g) together with nonlabeled enzyme and rabbit antiserum produced against homogeneous enzyme to develop a radioimmunoassay for arylsulfatase A in urine. A solid-phase, second-antibody technique (Immunobead Second Antibody; Bio-Rad Laboratories) was used to separate free enzyme from antigen-antibody complexes. The working range of the assay was 0.1-4.0 ng of enzyme; within- and between-assay CVs were around 10%, and the analytical recovery was 105.5% (SD 7.7%). The lower limit of detection was 0.08 ng of arysulfatase A per assay, substantially less than that of typical activity-based assays. Over a wide range of urinary arylsulfatase A activities, results by this method agreed well (r = 0.99) with those obtained by activity assays. We measured the enzyme in urines of 59 healthy volunteers and 92 patients with different diseases, including a group of colorectal cancer cases, to determine whether this could serve as a reliable marker for cancer of the colon; however, urinary excretion of arylsulfatase A by most patients with colon cancer was within normal limits.