bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analyses of creatine kinase isoenzymes and isoforms in serum to detect reperfusion after acute myocardial infarction.
Authors: Apple F S , Sharkey S W , Werdick M , Elsperger K J , Tilbury R T 
Published: January 2020

Abstract
Isoenzymes and isoforms of creatine kinase (CK, EC 2.7.3.2) were measured to assess reperfusion after acute myocardial infarction (AMI). In streptokinase-treated and in spontaneously reperfused AMI patients, total CK, CK-2 activity and concentration, and CK-3(3) isoform activity peaked significantly (p less than 0.05) earlier than conventionally treated, non-reperfused patients. The ratio for CK-3(3) to CK-3(1) activities peaked significantly (p less than 0.05) earlier in both the streptokinase-treated and spontaneously reperfused groups, and indicated a greater release of enzyme (higher ratio) than in the conventionally treated patients. The ratio of CK-3(3)/3(1) also peaked significantly (p less than 0.05) earlier in all three groups than did total CK, CK-2, and CK-3(3) activities or concentrations. The clearance rates of total CK, CK-2, and CK-3(3) were not significantly different in all three groups. Thus, the ratio CK-3(3)/3(1) was the earliest indicator of infarction in both reperfused and non-reperfused patients.
Prevalence of magnesium and potassium deficiencies in the elderly.
Authors: Touitou Y , Godard J P , Ferment O , Chastang C , Proust J , Bogdan A , Auzéby A , Touitou C 
Published: January 2020

Abstract
Concentrations of magnesium and potassium in erythrocytes and plasma were determined in a population of 381 unselected elderly men and women, most of them in their eighties. The effects of biological factors (age, sex, weight) and a large set of pathological conditions, malignant or not, were examined. Analyses of variance showed a relation between age and concentrations of plasma potassium and between weight and concentrations of plasma magnesium. The chi-square test showed correlations between low concentrations of plasma magnesium and diabetes, abuse of alcohol and tobacco, and also between low values for erythrocyte magnesium and hypertension. Low values for plasma potassium were correlated with hypertension whereas high values were correlated with cardiovascular disease. Although some of the differences in the mean concentrations observed were statistically significant, these differences were always small. Most interesting was the distribution of the concentrations of the cations. This study shows that assays of both of these cations in erythrocytes were better than assays in plasma to evidence a deficiency. Indeed, about 20% of the studied population had low concentrations of both erythrocyte potassium and magnesium, whereas 2 and 10% had low values for plasma potassium and magnesium, respectively. This study underlines the large prevalence of magnesium and potassium deficiencies in the elderly, an observation we could not attribute to pathology or treatment. Routine electrolyte studies therefore appear to be justified in aged human subjects.
Natural and recombinant DNA-derived human insulin-like growth factor-I compared for use in radioligand assays.
Authors: Baxter R C , De Mellow J S , Burleigh B D 
Published: January 2020

Abstract
We compared two preparations of human insulin-like growth factor (IGF)-I, one isolated from human plasma and the other prepared by recombinant DNA technology, for use in three radioimmunoassays and a radioreceptor assay for IGF-I, two radioreceptor assays for IGF-II, and a protein-binding assay for both IGFs. In the IGF-I assays, iodinated natural IGF-I consistently showed higher binding than did iodinated biosynthetic IGF-I, whether or not the iodopeptides were purified before use by hydrophobic interaction chromatography. Comparing the potency of the unlabeled peptides in the eight assay systems, we found the natural and the biosynthetic IGF-I to be equipotent in every case except for a radioimmunoassay involving a monoclonal IGF-I antibody (the synthetic peptide had 2.4 times greater activity), and an IGF-II radioreceptor assay involving ovine placental membrane receptors (the natural peptide had 10-fold greater activity). We conclude that recombinant DNA-derived IGF-I is suitable for use, both as a standard and as a radioligand, in a wide variety of IGF assays.
Comparison of Coomassie Brilliant Blue protein dye-binding assays for determination of urinary protein concentration.
Authors: Marshall T , Williams K M 
Published: January 2020

Abstract
We investigated the influence of assay protocol upon results of Coomassie Brilliant Blue protein dye-binding assays for urinary protein. Sensitivity and working range for, and linearity of response (including dilution dependence) of, three standard assays and four micro assays to bovine albumin, gamma-globulin, and urine are compared. The Read and Northcote standard assay (Anal Biochem 1981; 116:53-64) appears to be the method of choice.
Activity of phospholipase A compared in serum of patients with pancreatic and nonpancreatic diseases.
Authors: Schmidt D , Hoffmann G E 
Published: January 2020

Abstract
Phospholipase A (PLA) activity was measured with a semi-automated photometric test system that is based on liberation of fatty acids from phosphatidylcholine by phospholipases A1 (EC 3.1.1.32) and A2 (EC 3.1.1.4). We studied 528 serum samples from 86 patients whose lipase activities were increased owing to pancreatitis, pancreatic carcinoma, and extrapancreatic diseases. PLA activity showed no correlation with lipase or amylase activities or with the primary cause of the disease, but was clearly related to prognosis. Noncomplicated acute pancreatitis was characterized by "normal" PLA activities (0-10 U/L), whereas the values (50-137 U/L) were highest in necrotizing pancreatitis and septicemia with a lethal outcome. Changes in lipase and phospholipase A activities exhibited completely different time courses in the various diagnostic groups.
Immunoglobulin A (lambda chains) conjugated with lactate dehydrogenase in serum.
Authors: Burlina A , Secchiero S , Bertorelle R , Plebani M , Zaninotto M 
Published: January 2020

Abstract
An atypical pattern for lactate dehydrogenase (EC 1.1.1.27) isoenzymes in a patient with sclerosis of the bladder neck was ascribable to complexing between lactate dehydrogenase and IgA. This complex formation was also replicable "in vitro." We determined that the IgA bound to lactate dehydrogenase was of the lambda type, a very unusual occurrence.
Laboratory performance and regulatory requirements.
Authors: Kenney M L 
Published: January 2020

Abstract
We compared performance levels of four clinical laboratory groups defined by federal regulatory characteristics, to assess the appropriateness of selected regulations: laboratories in JCAH-accredited hospitals; non-doctoral-directed independent laboratories; state-regulated but federally exempt group-practice laboratories; and unregulated laboratories in physicians' offices (POLs). Federal regulations evaluated were those dealing with the doctoral directorship requirement and exemption of POLs from regulation. Quantitative analytes were compared by using linear regression on log-normal transformations of mean absolute-z scores of proficiency test results. The scope of services offered by laboratories was statistically related to performance in quantitative analytes. Confounding effects of scope-of-service levels were statistically controlled. Proportions of errors in qualitative analytes were compared. No pattern of statistically discernible differences in performance was found between hospital laboratories and non-doctoral-directed laboratories. Both regulated non-doctoral-directed laboratories and state-regulated but federally exempt group-practice laboratories demonstrated higher levels of performance than unregulated POLs.
Concentrations of morphine and codeine in serum and urine after ingestion of poppy seeds.
Authors: Hayes L W , Krasselt W G , Mueggler P A 
Published: January 2020

Abstract
We measured morphine and codeine in commercially available poppy seeds and in serum and urine samples from healthy adults who had ingested these poppy seeds. Four brands of black poppy seeds, examined by gas chromatography-mass spectroscopy (GC-MS) with deuterated internal standards, contained from 17 to 294 micrograms of morphine and 3 to 14 micrograms of codeine per gram of seeds. Morphine was detected by GC-MS in hydrolysates of serum as late as 24 h after ingestion, with a maximum mean concentration of 100 ng/mL (range 82-131) measured 2 h after the subjects ingested 25 g of seeds. Opiates were detectable (greater than 300 micrograms/L) in urine by enzyme-multiplied immunoassay (EMIT; Syva Co.) and by radioimmunoassay screening procedures for as long as 48 h after ingestion. The identity and quantities of morphine and codeine in poppy seed extracts and in hydrolysates of serum and urine were confirmed by GC-MS. Therefore a positive finding of morphine or codeine in blood and urine may sometimes be due to ingestion of poppy seeds.
Changes in cerebrospinal fluid IgG and apolipoprotein E indices in patients with multiple sclerosis during demyelination and remyelination.
Authors: Rifai N , Christenson R H , Gelman B B , Silverman L M 
Published: January 2020

Abstract
Approximately 85% of patients with multiple sclerosis (MS) can be diagnosed by using magnetic resonance imaging and laboratory tests such as determination of the cerebrospinal fluid (CSF) IgG Index and electrophoresis to detect oligoclonal banding. However, these tests results are abnormal in MS patients whether they are in clinical remission or acute exacerbation. Because apolipoprotein E (apo E) is synthesized in the central and peripheral nervous system, particularly during remyelination, we propose that apo E might be a reliable marker of the remyelination that accompanies clinical remission in MS patients. We studied 33 patients with MS, 22 in remission and 11 in exacerbation, and 26 controls of comparable ages. The apo E Index, calculated from the concentrations of apo E and albumin in CSF and serum, allowed us to discriminate between MS patients in remission and MS patients in exacerbation (P less than 0.001); the IgG Index failed to show similar differences. However, combining the apo E and IgG indices gave maximum discrimination between controls, MS patients in remission, and those in exacerbation. This study suggests that apo E measurements should be included in the laboratory evaluation of MS patients.
Critical evaluation of a commercial enzyme kit (Sigma) for determining oxalate concentrations in urine.
Authors: Parkinson I S , Sheldon W L , Laker M F , Smith P A 
Published: January 2020

Abstract
The Sigma reagent kit for urinary oxalate determination is reportedly simple, rapid, and specific for oxalate. We evaluated the kit and identified a number of shortcomings. Our investigations suggest that the recommended time for chromophore development is too short and should be doubled. Oxalate recovery during the extraction procedure depends strongly on urine pH. For complete extraction, urine should be acidified to pH 1.8-2.4. We also observed positive interference from ascorbate in urine. This interference was substantial, absorbances produced from ascorbate standards being approximately 80% of those obtained from oxalate standards of similar concentration. Our investigations also indicate the presence of a substance on the Sigma adsorbent that is eluted during the extraction procedure and interferes in the color reaction. These interferences represent potentially major sources of imprecision in the assay.
Clinical significance of a low concentration of thyrotropin: five immunometric "kit" assays compared.
Authors: Piketty M L , Talbot J N , Askienazy S , Milhaud G 
Published: January 2020

Abstract
We compared results of five sensitive immunometric assays of serum thyrotropin (TSH) in controls and in different groups of patients with hyperthyroidism, untreated or treated; secondary hypothyroidism; nonthyroidal illness (NTI); or depression; or who were being treated with amiodarone. With most kits, measured TSH concentrations did not overlap between controls and hyperthyroid patients. In untreated secondary hypothyroidism TSH was not always undetectable. Patients with NTI and depression showed many low TSH values, and among these categories of patients, we observed large discrepancies among the kits. This lack of specificity at low concentration means that one cannot assess hyperthyroidism by TSH measurement alone, but it can be used as the first screening test. Similarly, TSH determination cannot be used alone in monitoring therapy (e.g., with carbimazole, thyroxin, amiodarone) to assess the presence of hyperthyroidism. Nonetheless, this assay plays a well-established role in hypothyroidism detection. Four of the five kits were found useful for clinical evaluation, the fifth less so.
Immobilized purified folate-binding protein: binding characteristics and use for quantifying folate in erythrocytes.
Authors: Hansen S I , Holm J , Nexø E 
Published: January 2020

Abstract
Purified folate-binding protein from cow's milk was immobilized on monodisperse polymer particles (Dynospheres) activated by rho-toluenesulfonyl chloride. Leakage from the spheres was less than 0.1%, and the binding properties were similar to those of the soluble protein with regard to dissociation, pH optimum for binding pteroylglutamic acid, and specificity for binding various folate derivatives. We used the immobilized folate-binding protein as binding protein in an isotope-dilution assay for quantifying folate in erythrocytes. The detection limit was 50 nmol/L and the CV over a six-month period was 2.3% (means = 1.25 mumol/L, n = 15). The reference interval, for folate measured in erythrocytes of 43 blood donors, was 0.4-1.5 mumol/L.
Concentrations of iodothyronines in serum of patients with chronic renal failure and other nonthyroidal illnesses: role of free fatty acids.
Authors: Liewendahl K , Tikanoja S , Mähönen H , Helenius T , Välimäki M , Tallgren L G 
Published: January 2020

Abstract
The mean concentration of free thyroxin (FT4) in serum, as determined by direct equilibrium dialysis, was decreased in patients with chronic renal failure (CRF) and increased in patients with various other nonthyroidal illnesses (NTI). The mean concentration of dialyzable free triiodothyronine (FT3) in serum was equally low in both groups of patients. Patients with CRF of various etiology but a similar degree of renal failure as estimated from serum creatinine assay had very similar concentrations of FT4 and FT3 in their serum. Mean thyroxin (T4) and triiodothyronine (T3) concentrations in serum were decreased in CRF and NTI, whereas the mean reverse-T3 concentration in serum was normal in CRF and increased in NTI. T4-binding globulin and albumin were markedly decreased in CRF and NTI; T4-binding prealbumin was increased in CRF and decreased in NTI. The mean concentration of nonesterified free fatty acids (FFA) in serum was increased in NTI but not in CRF. The weak, but significant, positive correlation observed between FT4 and FFA in serum (r = 0.34, P less than 0.01) in NTI indicates that the increase in serum FT4 in this group of patients could be an effect, at least in part, of FFA competing with T4 for binding sites on serum proteins. The stronger correlation detected between the serum FT4 concentration and the FFA/albumin molar ratio in serum (r = 0.60, P less than 0.001) demonstrates the importance of a low albumin concentration for expression of the effect of FFA on FT4 in severe systemic illnesses.
Biological variation of blood acid-base status: consequences for analytical goal-setting and interpretation of results.
Authors: Harding P J , Fraser C G 
Published: January 2020

Abstract
Analytical, intra-individual, and interindividual components of variation have been determined for pH, pCO2, bicarbonate, base excess, and total CO2 in capillary specimens of whole blood from a cohort of 14 healthy subjects. Calculated analytical goals (SD) are pH less than or equal to 0.008, pCO2 less than or equal to 0.9 mmHg, bicarbonate less than or equal to 0.5 mmol/L, base excess less than or equal to 0.5 mmol/L, and total CO2 less than or equal to 0.5 mmol/L. Because pH and base excess vary little between individuals, population-based reference values for them will be of utility in interpretation of results; pCO2, bicarbonate, and total CO2 show more marked variation between individuals, and reference values for them will be of more limited use. The generally applicable differences required for two results to be significantly different (P less than or equal to 0.05) when goals are met--which is currently feasible--are pH: 0.04, pCO2: 0.745 kPa (5.6 mmHg), bicarbonate: 2.6 mmol/L, base excess: 2.2 mmol/L, and total CO2: 2.7 mmol/L.
Thyroid function in hospitalized patients: effect of illness and serum albumin concentrations.
Authors: Desai R K , Jialal I , Aitchison J M , Joubert S M 
Published: January 2020

Abstract
We assessed the clinical utility of measuring thyrotropin (TSH) in serum by immunoradiometry and of measuring total thyroxin (TT4), total triiodothyronine (TT3), free thyroxin (FT4), and free triiodothyronine (FT3). We used a group of 110 healthy volunteers, 45 ill hypoalbuminemic patients, and 42 ill normoalbuminemic patients. In addition, the free thyroxin index (FTI) and TT4:thyroxin-binding globulin (TBG) ratio were also calculated. The hypoalbuminemic group had significantly lower FT4, FT3, TT4, TT3, and FTI concentrations, but only FT3 and TT3 were significantly lower in the ill normoalbuminemic group as compared with controls. We found significant correlation between FT4 and albumin (r = 0.372, P less than 0.001) and FT3 and albumin (r = 0.465, P less than 0.001). TSH concentrations were undetectable in two of 45 hypoalbuminemic patients, significantly higher in the rest. The TT4/TBG ratio was the only parameter of thyroid function that remained unchanged in the ill patients.
A New Method for Reporting the Sources of Abnormal Activities of Lactate Dehydrogenase in Serum
Authors: Politser Peter E , Powell Stephen H , Fink Jeffrey 
Published: January 2020

Abstract
Vol 32
p 1522: The unnumbered equation preceding equation 3 should read:
and equation 3 should read:
Vol 33
p225: The normal reference interval for albumin in urine should read 0.01 to 0.11 g per day.
A high-speed liquid-chromatographic method for measuring urinary porphyrins.
Authors: Johnson P M , Perkins S L , Kennedy S W 
Published: January 2020

Abstract
We describe a rapid quantitative and qualitative "high-performance" liquid-chromatographic (HPLC) method for measuring porphyrins in urine. Direct injection of acidified, filtered urine onto a 3-micron (particle size) 3-cm-long reversed-phase column fully resolves uroporphyrin, hepta-, hexa-, and pentacarboxylic acid porphyrins, and coproporphyrin. Instrument response is linearly related to concentration over the range 25 to 300 nmol/L. The method provides data essential for the differential diagnosis of porphyric states, including porphyria variegata and porphyria cutanea tarda. This relatively inexpensive method requires a run time of only 8 min per sample, making it particularly suitable for routine use in the clinical chemistry laboratory.
Ten commercial kits compared for assay of thyrotropin in the normal and thyrotoxic range.
Authors: Evans M C 
Published: January 2020

Abstract
I developed a standard procedure for assessing sensitivity, intra-assay precision, parallelism of sample dilutions, and assay drift, using a single trial assay kit. I used this to compare the performance of 10 commercial kits with an in-house radioimmunoassay for human thyrotropin. No one kit stood out as clearly superior overall. Differences in calibration between kits were evident in a comparison of thyrotropin concentrations measured in clinical samples, and by direct comparison of standards from different kits in a single assay. However, all kits gave clinically consistent results with respect to their published normal reference interval. Moreover, the performance of human thyrotropin assay kits has improved during the 14 months of this study.
Isolation of the acidic phospholipid phosphatidylglycerol from pulmonary surfactant by sorbent extraction chromatography.
Authors: Egberts J , Bulskool R 
Published: January 2020

Abstract
Aminopropyl solid-phase columns can be used for phospholipid fractionation. A method has been developed to elute the acidic phospholipid phosphatidylglycerol (PG) separately, and it is applicable to both standard (phospho)lipid mixtures and pulmonary surfactants. The simplicity, rapidity, and high recovery make this method of isolating PG superior to other chromatographic procedures.
An enzymatic method for 5-fluorocytosine.
Authors: Huang C M , Kroll M H , Ruddel M , Washburn R G , Bennett J E 
Published: January 2020

Abstract
We developed an enzymatic method for determination of 5-fluorocytosine in serum, using creatine iminohydrolase (EC 3.5.4.21), the Cobas-Bio analyzer, and an extant ammonia method. Analytical recovery (y) of drug added to serum (x) was good, with y = 0.97x-0.7, Sy.x = 3.6, r = 0.997 (n = 65) over the range 6.25 to 150 mg/L. Comparison with an HPLC method (x) showed good agreement: y = 0.98x + 1.34, Sy.x = 3.7 (n = 37), as analyzed with the Deming debiased regression. Precision was good, CVs being less than 3% for within-run and less than 6% for between-run controls. Ammonia, amphotericin B, glucose, urea, and hemolysis do not interfere, but bilirubin shows analyte-dependent interference and lipemia interferes when triglycerides exceed 5 g/L. This assay is accurate, inexpensive, and easy to perform. It can be easily adapted for routine or emergency use.
Variation in cytosolic protein expression between human colon tumors that differ with regard to differentiation class.
Authors: Nalty T J , Taylor C W , Yeoman L C 
Published: January 2020

Abstract
Using a combination of two-dimensional gel electrophoresis, silver staining, and a 16-quadrant grid system, we established a set of composite patterns for the colon tumor cytosol proteins of well, moderately, and poorly differentiated tumors. These composite patterns were found to be characteristic of the three individual differentiation classes for colon tumors. The apparent relative molecular masses (Mr) of the resolved proteins ranged from 14,000 to 105,000 and their isoelectric points from pH 5.2 to 8.4. Although the vast majority of the proteins identified in the composite patterns were common, a comparison based upon these patterns revealed two qualitative and seven quantitative protein differences. The qualitative differences were identified by apparent Mr X 10(-3)/pI coordinates of 73/7.2 and 66/6.2. Quantitative differences were identified by Mr X 10(-3)/pI coordinates of 71/6.0, 59/6.7, 57/6.7, 56/5.4, 52/6.1, 30/5.8, and 18/6.2. These cytosolic differentiation marker proteins may facilitate the diagnosis, staging, and monitoring of human colon cancer.