bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aminotransferase as a prognostic index in infants with liver disease
Authors: Rosenthal P , Haight M 
Published: January 2020

Abstract
To assess the utility of the serum aspartate aminotransferase/alanine aminotransferase (AST/ALT) ratio in a group of infants with liver disorders, we retrospectively analyzed the charts of 73 infants with chronic liver disorders. Patients were considered as having either a good outcome (n = 40) or a poor outcome (n = 33), based upon the clinical course. AST and ALT in serum were measured simultaneously at the time of initial presentation and at various follow-up visits during the first 13 months after birth. At presentation (mean age 1.65 months), there was no difference in the AST/ALT ratios between the good (1.61 +/- 0.62; mean +/- SD) and poor (1.65 +/- 0.78) outcome groups (P = 0.81). However, over time, the AST/ALT ratio increased in patients in the poor-outcome group and decreased in patients in the good-outcome group. Calculating the AST/ALT ratio appears to be an easy, early, and reliable prognostic indicator for infants with hepatic disease, and may be a useful measure for evaluating liver-disease patients.
Method comparison for calcium determination by flame atomic absorption spectrophotometry in the presence of phosphate
Authors: Welch M W , Hamar D W , Fettman M J 
Published: January 2020

Abstract
We investigated the suppressive effects of phosphate on calcium determinations with lanthanum-air/acetylene and potassium-nitrous oxide/acetylene methods, and we evaluated the ability of these methods to meet the suggested analytical goals for urine samples. The 20 g/L La-air/acetylene method was the most nearly accurate for predicting the actual calcium concentrations (t-test value = -0.042), followed by the 2 g/L K-nitrous oxide/acetylene method (t-test value = 0.450), 10 g/L La-air/acetylene (t-test value = -0.733), and finally 5 g/L La-air/acetylene (t-test value = -2.446). The dilution used significantly influences the apparent calcium concentration measured with the La-air/acetylene methods.
A comparison of results for cholesterol in human serum obtained by the Reference Method and by the Definitive Method of the National Reference System for cholesterol
Authors: Ellerbe P , Myers G L , Cooper G R , Hertz H S , Sniegoski L T , Welch M J , White E 
Published: January 2020

Abstract
Here we compare the Reference Method (I) and the Definitive Method (II) for measurement of cholesterol in serum. For pure cholesterol solutions, values by I agree with values by II, but for fresh, frozen, or lyophilized sera, values by I average 1.6% higher than values by II. We conclude that an undetected interference is associated with I. However, the observed difference does not diminish the usefulness of I as an accuracy base for cholesterol measurements, because it is clinically insignificant at present.
Monoclonal immunoradiometric assay of calcitonin improves investigation of familial medullary thyroid carcinoma
Authors: Perdrisot R , Bigorgne J C , Guilloteau D , Jallet P 
Published: January 2020

Abstract
Calcitonin (CT) assay is essential for recognizing medullary thyroid carcinoma (MTC), particularly occult familial MTC. In previous radioimmunoassays of calcitonin, polyclonal antibodies were used. Here we evaluate a new two-site immunoradiometric assay (IRMA) of calcitonin based on use of monoclonal antibodies. We assayed samples from healthy subjects, patients with renal failure, and subjects from families affected by MTC. Basal values for healthy subjects were all less than 10 ng/L. Renal failure is associated with increased basal CT. The CT peak under pentagastrin stimulation in healthy patients was less than 30 ng/L. In familial screening, basal values greater than 10 ng/L or peak values greater than 30 ng/L correspond to subjects with histologically confirmed MCT or micro-MCT. Polyclonal RIA performed in the same subjects failed to detect the moderate increase of CT that IRMA demonstrated. Preliminary results indicate that this new method may allow earlier detection of CT increase and thus improved diagnosis of MCT, particularly in familial screening. Monitoring surgical patients could also be improved by this new assay.
Valproic acid-associated pancreatitis: report of three cases and a brief review
Authors: Lott J A , Bond L W , Bobo R C , McClung H J , Murray R D 
Published: January 2020

Abstract
We describe three patients with seizure disorders in whom pancreatitis or pancreatic injury was probably caused by valproic acid, a widely used anticonvulsant drug. Trivial or no increases of serum amylase (EC 3.2.1.1) but striking increases of serum lipase (EC 3.1.1.3) were common to all patients, as assayed in the Kodak Ektachem. In vitro, valproic acid does not cause any change in serum lipase. In patients with symptoms suggestive of pancreatitis and abnormal values for amylase and (or) lipase, treatment with valproic acid should be discontinued.
Neutral ionophore-based selective electrode for assaying the activity of magnesium in undiluted blood serum
Authors: Rouilly M , Rusterholz B , Spichiger U E , Simon W 
Published: January 2020

Abstract
The concentration of free, ionized magnesium in undiluted blood serum can be determined potentiometrically with a new magnesium-selective carrier in polymeric membrane electrodes (by weight 66% plasticizer, approximately 33% polyvinyl chloride and approximately 1% ionophore). However, discrimination of calcium by the new ionophore-added membrane is not sufficient to keep calcium interference to less than 1%. To correct for the interference by calcium, we determine the calcium activity of the serum sample with a calcium-selective electrode and calibrate the magnesium-selective electrode with standard solutions containing calcium in the concentrations found. In this way we determined the free ionized magnesium in five plasma samples from five different persons and found it to be within the range expected for magnesium in undiluted serum.
Concentrations of free thyroxin and free triiodothyronine in serum of patients with thyroxin- and triiodothyronine-binding autoantibodies
Authors: John R , Henley R , Shankland D 
Published: January 2020

Abstract
Between 1982 and 1989 we identified 47 subjects with spuriously increased concentrations of free thyroxin (FT4) or free triiodothyronine (FT3) related to autoantibody interference in analog FT4 and (or) FT3 methods. The incidence of autoantibody interference observed during one year (1988) was 1 in 2460. In the subjects identified, 51% and 11%, respectively, showed an increased binding of radiolabeled T4 or T3 analog alone; 38% had an increased binding of both. Of 36 patients tested, 71% had autoantibodies to thyroglobulin and microsomal fraction of the thyroid, 19% to microsomal fraction alone, and 9.5% to thyroglobulin alone. In eight subjects, spuriously increased FT4 concentrations were reported with the following FT4 methods (in decreasing order of interference): Coat-A-Count, Amerlex-M, Amerlite, Seria, Magic Lite, Amerlex-MAB. In the same eight subjects, Amerlex-M and Seria reported spuriously increased concentrations of FT3.
Medically significant concentrations of prostate-specific antigen in serum assessed
Authors: Bernstein L H , Rudolph R A , Pinto M M , Viner N , Zuckerman H 
Published: January 2020

Abstract
We used the method of Rudolph et al. (Clin Chem 1988; 34:2031-8) to find information in the data from correlated determinations of acid phosphatase (PAP, EC 3.1.3.2; DuPont aca) and prostate-specific antigen (PSA, Hybritech). We described there how we assign medical decision limits for two or more correlated variables and convert the database to a binary coded message, allowing separation of a selected disease class with minimum error. The decision point, analogous to a percentile upper limit on the ordered values of each variable in the reference group, satisfies the maximum entropy constraints of reference, producing a minimum entropy for the binary coded patient database. We found maximum entropy decision points at PAP = 0.75 U/L and PSA = 22.8 micrograms/L. Patients with PSA values exceeding 22.8 micrograms/L had no benign prostatic disease except for five patients with benign prostate hyperplasia (BPH) with adjacent colon carcinoma (95.3), BPH with infarction (27.6), BPH (23.4) 28.1), or acute prostatitis (34.6). We consider PSA exceeding 22.8 micrograms/L as indicative of carcinoma of the prostate, stage C or D, in the absence of disconfirming evidence. Another decision value for PSA is 11.3 micrograms/L. This bounds the region between 11.3 and 22.8 micrograms/L, where the frequency of BPH is 1.5 times that for adenocarcinoma. At PSA less than 11.3 micrograms/L there is a high frequency of BPH. PSA concentration is not correlated with prostatic size (mass) or with prostatitis. A metastatic carcinoma is as likely to be nonprostatic as prostatic when the PSA concentration is less than 11.3 micrograms/L.
Effect of serum lyophilization on the rate constants of enzymatic methods for measuring cholesterol
Authors: Kroll M H , Chesler R 
Published: January 2020

Abstract
We determined the equilibrium absorbances and rate constants for two enzymatic methods, aca (DuPont) and RA-1000 (Technicon), used in determining cholesterol in reconstituted lyophilized serum. The lyophilized materials included two serum pools, three control materials, a College of American Pathologists' survey material, and Standard Reference Material no. 909. We calibrated the reagents with aca standards for cholesterol (DuPont). The difference in the mean concentrations of cholesterol (aca - RA-1000) was -0.09 g/L overall and was not statistically significant by analysis of variance. The mean rate constant for all materials was 0.23 min-1 for the aca and 1.42 min-1 for the RA-1000, significantly different (P less than 0.001). Lyophilization causes lower results for the aca method than for the Ra-1000, because the reaction rate for the aca method is slower and has not reached equilibrium when the final absorbance reading is made.
Adjusted ionized calcium (at pH 7.4) and actual ionized calcium (at actual pH) in capillary blood compared for clinical evaluation of patients with disorders of calcium metabolism
Authors: Thode J , Holmegaard S N , Transbøl I , Fogh-Andersen N , Siggaard-Andersen O 
Published: January 2020

Abstract
We report results for adjusted ionized calcium (at pH 7.4) and actual ionized calcium (at actual pH) in capillary blood from 183 patients with disorders of calcium metabolism (primary hyperparathyroidism, secondary hyperparathyroidism of malabsorption, primary hypoparathyroidism, Paget's disease, acromegaly, hypercalcemia of malignancy, osteoporosis, sarcoidosis, idiopathic hypercalciuria, and familial hypocalciuric hypercalcemia). The correlation and the equation for the linear regression between adjusted ionized calcium (y) and actual ionized calcium (x) were y = 1.011x + 0.005 mmol/L, r = 0.992, Sy,x = 0.021 mmol/L. Results were similar within each diagnostic group. Consistent agreement between adjusted and ionized calcium was observed in 96.7% of patients representing a variety of the most frequently encountered disorders of calcium metabolism. Thus we find adjusted ionized calcium to be as useful as actual ionized calcium for evaluation of patients with such disorders. Adjusted ionized calcium may therefore also be a logical choice for establishing agreement between laboratories for reference intervals in healthy adults.
A two-tube immunochemical method for determination of CK-MB isoenzyme in serum evaluated
Authors: Panteghini M , Bonora R , Pagani F 
Published: January 2020

Abstract
A new commercial kit (Impres-MB; International Immunoassay Labs.) recently was introduced for measuring the MB isoenzyme of creatine kinase (CK-MB) based on the use of monoclonal antibodies. After antibodies to CK-MM isoenzyme are added to precipitate the CK-MM, antibodies to CK-M monomer are added to precipitate the M-subunit isoenzymes of CK. Subtracting the enzymatic activity of the second supernate from the residual activity in the first yields the activity of CK-MB. Results are not affected by CK-BB, mitochondrial CK, or adenylate kinase. However, the anti-CK-MM antibodies precipitated only about 98% of serum CK-MM and may have partly precipitated CK-MB isoenzyme (average analytical recovery of CK-MB, 86.6%). Comparison between Impres-MB (y) and electrophoresis (x) yielded the following linear-regression equation: y = 0.79x + 3 (r = 0.982, n = 97). Data for CK-MB temporal kinetics, obtained from patients with myocardial infarction, correlated significantly in both methods; however, peak activity values of CK-MB were significantly different, confirming that the difference between the new method and the electrophoretic method average 20%.
A study of the CEDIA digoxin immunoassay
Authors: Murthy V V , Karmen A 
Published: January 2020

Abstract
We evaluated the CEDIA digoxin immunoassay (Microgenics, Inc., Concord, CA), as performed with the Cobas-Bio centrifugal analyzer. In assays of sera with known concentrations of digoxin, the enzyme activity, measured when two beta-galactosidase (EC 3.2.1.23) fragments were combined according to the assay format, was proportional to the digoxin concentration. Results of assays of sera containing 0 to 3 micrograms of digoxin per liter correlated well when compared with an RIA method: CEDIA, microgram/L = 1.00 x RIA - 0.06 microgram/L (n = 90, r = 0.95, Sxy = 0.05). Duplicate assays of three control sera containing 0.8, 2.2, or 3.3 micrograms/L, each analyzed 20 times a day with each group of patients' samples, gave within-run CVs of 1-3% and day-to-day CVs of 3-12%. The reconstituted CEDIA reagents were stable for at least a month at 5 degrees C. As many as 25 samples and controls can be assayed in half the time needed to complete a similar number of RIA measurements with comparable results.
Role of the clinical laboratory in guiding treatment of Amanita virosa mushroom poisoning: report of two cases
Authors: Piering W F , Bratanow N 
Published: January 2020

Abstract
Historically, mortality after Amanita mushroom ingestion has ranged from 50% to 90%. Prompt diagnosis is imperative, and aggressive therapeutic measures must be instituted quickly to improve the outcome. We report successful treatment of two cases of A. virosa poisoning by use of combined therapies, including thioctic acid and hemoperfusion.
S-100ao protein in serum during acute myocardial infarction
Authors: Usui A , Kato K , Sasa H , Minaguchi K , Abe T , Murase M , Tanaka M , Takeuchi E 
Published: January 2020

Abstract
Concentrations in serum of S100ao protein (alpha alpha form of S-100 protein, which is present at high concentrations in heart muscle) were successively measured by enzyme immunoassay in 21 patients with acute myocardial infarction (AMI) and six with angina pectoris (ANP). Results were compared with measurements of creatine kinase isoenzyme MB (CK-MB) concentrations in the same specimens. Mean S100ao concentrations in sera from 100 healthy adults were 0.12 (SD 0.08) microgram/L. In patients with AMI, S100ao concentrations were 4.74 +/- 5.27 micrograms/L at admission, peaked 8 h after admission (23.5 +/- 27.7 micrograms/L), then decreased gradually. Among nine AMI patients who were admitted within an hour after their attack, eight showed abnormally high concentrations of S100ao in serum (greater than 0.5 microgram/L), whereas only four showed abnormally high CK-MB concentrations (greater than 5 micrograms/L) in sera at the time of admission. Serum S100ao concentrations remained within the normal range in all six patients with ANP; however, serum CK-MB concentrations were increased in two of them. Therefore, serum S100ao is useful not only for detection of AMI but also for differentiating AMI from ANP.
Direct and indirect techniques for free thyroxin compared in patients with nonthyroidal illness. III. Analysis of interference variables by stepwise regression
Authors: Csako G , Zweig M H , Ruddel M , Glickman J , Kestner J 
Published: January 2020

Abstract
We applied stepwise regression for multivariate analysis of data for free thyroxin (FT4) in serum and for other laboratory tests of thyroid function in patients with nonthyroidal illness. Using the maximum R2 improvement and backward elimination methods to test five variables [prealbumin, albumin, T4-binding globulin (TBG), free fatty acids (FFA), and FFA/albumin molar ratio], we found that the variables with the greatest predictive power clustered according to the methodology of FT4 measurement. Thus, we best predicted the FT4 results obtained by 16 techniques as follows: FT4 measured by one-step (analog) RIAs, with albumin; FT4 determined by two-step (sequential) RIAs, with FFA or FFA/albumin molar ratio; FT4 estimated by a binding-rate-based RIA or conceptually related FT4 indices [based on triiodothyronine (T3) uptake], with TBG; FT4 measured by equilibrium dialysis, with TBG and FFA/albumin molar ratio; and T4/TBG ratios, with either none or prealbumin and albumin. We could very highly (P less than 0.001) predict total T4 and T3 by considering TBG, and total T3 also by considering prealbumin and albumin, whereas reverse T3 was predictable with prealbumin only (negative relationship). We found comparatively weak associations between thyrotropin (TSH) and albumin or TBG. In clinical practice, abnormalities in key variables should call attention to possible effects of these variables on FT4 and other thyroid-test results and thus to the need for appropriate correction or alternative testing.
Human choriogonadotropin (hCG): comparisons between determinations of intact hCG, free hCG beta-subunit, and "total" hCG + beta in serum during the first half of high-risk pregnancy
Authors: Thomas C M , Reijnders F J , Segers M F , Doesburg W H , Rolland R 
Published: January 2020

Abstract
We have studied the concentrations of intact human choriogonadotropin (hCG) and the free hCG beta-subunit in blood samples from singleton pregnancies at risk for habitual or threatened abortion. The samples were obtained weekly between the 6th and 12th weeks and in the 14th and 16th weeks of gestational age. The concentrations of intact hCG, of the free hCG beta-subunit, and of "total" hCG (i.e., intact hCG and the free hCG beta-subunit: hCG + beta) were measured in serum by specific immunoassays. The distributional statistics (the 5th, 50th, and 95th percentiles) of "total" hCG + beta and of intact hCG showed very similar patterns, whereas the response curves for the free hCG beta-subunit showed very much lower serum concentrations. From these data we also estimated distributional statistics of the percent molar ratios of free hCG beta-subunit to intact hCG. We conclude that (a) the relatively small proportion of free hCG beta-subunit in serum during the first half of singleton pregnancy is far too low to interfere with the applied "total" hCG assay, as compared with the serum values obtained for intact hCG, and (b) the percent molar ratios of free hCG beta-subunit to intact hCG, or to "total" hCG + beta, never exceeded 1.0% throughout the period of pregnancy studied.
A validation study of selected methods routinely used for measurement of cyclosporine
Authors: Blick K E , Melouk S H , Fry H D , Gillum R L 
Published: January 2020

Abstract
We compare four methods for measuring cyclosporine (CyA) in plasma and whole blood of transplant patients: HPLC, RIA with a polyclonal antibody, RIA with a monoclonal antibody, and fluorescence polarization immunoassay (FPIA). The monoclonal RIA procedure correlated acceptably with HPLC, with slope = 1.21, r = 0.97, and Sy,x = +/- 40.1. However, the FPIA, done in three separate instruments, correlated relatively poorly with HPLC, giving slopes of 1.67, 1.51, and 2.32; correlation coefficients of 0.72, 0.43, and 0.83; and Sy,x = +/- 205.4, +/- 334.5, and +/- 222.4. The polyclonal RIA correlated reasonably well with HPLC, with a slope = 1.15, r = 0.90, and Sy,x = +/- 72.6. Values for individual patients with increases both in gamma-glutamyltransferase and creatinine showed very poor correlation between FPIA and HPLC, which suggests that metabolite cross-reactivity with FPIA is significant and unpredictable in patients with liver dysfunction coexisting with renal dysfunction. Evidently, the monoclonal RIA can be substituted for HPLC, if the therapeutic range is adjusted for the 21% higher results obtained by RIA.
Diagnosis of the multiglandular endocrine neoplasias
Authors: Bone H G 
Published: January 2020

Abstract
Multiglandular endocrine neoplasia syndromes are disorders characterized by autosomal dominant inheritance patterns and by the striking patterns of clinical presentation of these endocrine tumors, which are often hormonally active. Not every patient with adenomas of more than one endocrine gland has one of these classical familial syndromes. This paper will deal with the specific diseases known as multiglandular endocrine neoplasia Types 1, 2A, and 2B. Types 2A and 2B are also known as Types II and III.
Chemiluminescent measurement of total urinary nitrogen for accurate calculation of nitrogen balance
Authors: Skogerboe K J , Labbé R F , Rettmer R L , Sundquist J P , Gargett A M 
Published: January 2020

Abstract
This instrumental method for total urinary nitrogen (TUN) is based on the principle of gas-phase chemiluminescence. Results correlate well with measurements of TUN by the Kjeldahl method, which has long provided the means to calculate nitrogen balances for nutritional management. In recent years, because of speed and convenience of measurement, determination of urinary urea nitrogen (UUN) has been substituted for Kjeldahl TUN. However, in patients requiring aggressive nutritional support, the UUN may not be a valid indicator of total nitrogen excretion. We compared nitrogen balances calculated for patients, using both UUN and chemiluminescence TUN data. For both normal and hospitalized populations, nitrogen balance calculated from UUN data exceeded that calculated from TUN data. We show that use of UUN data in calculating nitrogen balance may result in an incorrect assessment of many patients as being in positive nitrogen balance. TUN determined by chemiluminescence evidently provides a simple means of calculating nitrogen balance more nearly accurately.
Indicators of acute renal-transplant rejection in patients treated with cyclosporine
Authors: Mueller P W , Delaney V , MacNeil M L , Caudill S P , Steinberg K K 
Published: January 2020

Abstract
We evaluated the ability of three enzymes--N-acetyl-beta-D-glucosaminidase (NAG; EC 3.2.1.30), alanine aminopeptidase (AAP; microsomal aminopeptidase, EC 3.4.11.2), and gamma-glutamyltransferase (GGT; EC 2.3.2.2)--and adenosine deaminase binding protein (ABP) in urine to predict or confirm renal-transplant rejection in patients treated with cyclosporine. We measured the enzymes daily during the early post-transplant hospital stay of 104 renal-transplant recipients (72 men and 32 women). We also measured ABP in 32 of these patients. We analyzed the data by calculating the activity ratio of each day's test value to the previous day's result and optimized the sensitivity (SN) and specificity (SP) to determine the optimal ratio for each test. The results indicate that cyclosporine treatment reduces the optimal sensitivity and specificity of these tests. Three comparable tests (ABP, GGT, and AAP) yield the best optimal values (SN = 0.77, 0.69, 0.77; and SP = 0.71, 0.74, 0.63, respectively), and the NAG test yields the lowest combination of sensitivity and specificity (SN = 0.62, SP = 0.66). All four tests were less sensitive and specific than the plasma creatinine test (optimal day-to-day difference = 5 mg/L). However, the ABP and AAP tests gave indications of rejection at least 24 h before clinical diagnosis for 50% of the patients experiencing rejection, while early plasma creatinine increases of 5 mg/L occurred in only 19% of this group.