bluuebunny/crossref_metadata_2025_split huggingface dataset:
Measurements of serum gamma-seminoprotein and prostate specific antigen evaluated for monitoring carcinoma of the prostate.
Authors: Siddall J K , Shetty S D , Cooper E H 
Published: January 2020

Abstract
We have compared the concentrations in serum of gamma-seminoprotein (gamma-SM) and prostate specific antigen (PSA), two antigens of prostatic origin that are synthesized independently of prostatic acid phosphatase (PAP, EC 3.1.3.2), to assess their potential in monitoring prostatic cancer. At presentation, 27/30 (90%) patients with metastases had a PSA concentration greater than 10 ng/mL, and 29/30 (97%) a gamma-SM concentration greater than 10 ng/mL; 21/61 (34%) with disease but without metastases had an abnormal content of PSA, and 23/61 (38%) an abnormal gamma-SM. Concentrations of PSA and gamma-SM were significantly correlated (r = 0.68, p less than 0.001). In 20 patients without metastases followed longitudinally, the median concentrations of gamma-SM, PSA, and PAP in the 13 patients who developed bony metastases or showed signs of local spreading of the tumor were 58 ng/mL, 34 ng/mL, and 2.1 U/L, respectively. The corresponding median values in the seven patients who remained clinically stable were 2.5 and 3.9 ng/mL, and 2.3 U/L. We conclude that either PSA or gamma-SM can warn of disease progression when PAP activities are still within normal limits.
Evaluation of an enhanced luminescence assay for alpha-fetoprotein.
Authors: John R , Henley R , Shankland D 
Published: January 2020

Abstract
We evaluated a two-site enhanced luminescence immunoenzymometric assay (Amerlite; Amersham International) for alpha-fetoprotein (AFP) in maternal serum and amniotic fluid. The assay is rapid, involving two incubations totalling 4 h. The working range of the assay for serum AFP is 5.5 to 750 kilo-int. units/L (CV less than 10%), with a sensitivity of detection of 0.2 kilo-int. unit/L. The regression equation for the Amerlite assay (y) and our in-house RIA procedure (x) was y = 0.816x + 2.9 (n = 142, r = 0.96). Analytical recovery of added AFP (code 72/227) at three concentrations was 86.7%. Serum AFP concentrations were measured at 15 to 18 weeks of gestation in subjects with normal pregnancies and in subjects whose pregnancies resulted in open neural tube defects; all of the latter had serum AFP concentrations greater than 2.5 multiples of the median. We find the Amerlite system to be an efficient, reliable system for screening for open neural tube defects without use of hazardous radioactive labels.
6 beta-hydroxycortisol in serum and urine as determined by enzyme immunoassay on microtitre plates.
Authors: Zhiri A , Mayer H A , Michaux V , Wellman-Bednawska M , Siest G 
Published: January 2020

Abstract
We modified our previous enzyme immunoassay (Clin Chim Acta 1986;157:267-76) for estimating 6 beta-hydroxycortisol (6 beta-OHF) to provide a more routine procedure for measuring it in urine and to increase sensitivity for its measurement in serum. Precision, analytical recovery, specificity, and detection limit are reported. 6 beta-OHF and 17-hydroxycorticosteroids in 24-h and 4-h (08:00-12:00 h) urine collections from healthy volunteers showed no significant day-to-day differences in excretion rate for either collection period. Mean values for 6 beta-OHF in serum of men, women, and women taking oral contraceptives showed no significant differences among these groups.
Age dependence of tissue plasminogen activator concentrations in plasma, as studied by an improved enzyme-linked immunosorbent assay.
Authors: Rånby M , Bergsdorf N , Nilsson T , Mellbring G , Winblad B , Bucht G 
Published: January 2020

Abstract
A procedure for improving the specificity of enzyme-linked immunosorbent assays (ELISA) was devised, based on addition of antigen-specific or non-immune immunoglobulins to the citrated plasma sample and defining the difference in assay response between these two mixtures as the antigen-specific part of the response. When applied to measurement of tissue plasminogen activator (t-PA; EC 3.4.21.31) antigen in plasma, this procedure resulted in elimination of the overestimates obtained in a large proportion (10-20%) of patients' samples when assayed according to the conventional ELISA technique. Basal t-PA concentrations in plasma were found to be highly age-dependent, normal values being about 3 micrograms/L for adults near 30 years of age and about 10 micrograms/L for those over 60. Patients with gallbladder stone disease had increased mass concentrations of t-PA in plasma, even when corrected for the age effect; patients with multi-infarct dementia did not.
Validation of a semi-automated technique for measuring lactate in whole blood.
Authors: Weil M H , Leavy J A , Rackow E C , Halfman C J , Bruno S J 
Published: January 2020

Abstract
An electrode-based lactate analyzer was recently developed to facilitate "stat" laboratory measurement of lactate in whole blood. The results obtained with this technique were compared with those of our continuous-flow enzymatic method for 172 analyses of samples from 25 pigs; 88 analyses of samples from 12 normal human volunteers before, during, and after exercise; and 91 analyses of samples from 80 critically ill patients. This comparison revealed strongly significant linear correlations: r = 0.992 for the porcine analyses and r = 0.994 for the combined human analyses. In analytical-recovery studies with pooled porcine plasma with an initial lactate concentration of 3.85 mmol/L, 94.3% of added lactate (1, 5, and 10 mmol/L) was accounted for in the electrode technique, 96% in the reference technique. We conclude that the electrode-based lactate analyzer is rapid, precise, and accurate for measurement of lactate in whole-blood samples.
Enhanced luminescence immunoassay: evaluation of a new, more sensitive thyrotropin assay.
Authors: John R , Henley R , Chang D , McGregor A M 
Published: January 2020

Abstract
We measured thyrotropin (TSH) with an enhanced luminometric assay ("Amerlite"; Amersham International). The detection limit of the assay is 0.02 milli-int. unit/L. Within-assay precision was 6.7 and 7.8% at 3.77 and 12.1 milli-int units/L, respectively, and between-assay precision was almost identical, whether singleton or duplicate samples were assayed. TSH measured in 132 euthyroid subjects ranged from 0.06 to 4.13 milli-int. units/L (mean 1.52, SD 0.86). Similar concentrations were found in 20 healthy pregnant women and 19 of 20 healthy post-menopausal women (one of whom had undetectable TSH). In 17 patients with primary hypothyroidism, TSH concentrations ranged from 9.34 to greater than 200 milli-int. units/L; and in 53 of 59 patients with hyperthyroidism, TSH concentrations were undetectable, ranging in the remaining six from 0.03 to 0.06 milli-int. unit/L. Results for TSH in 28 patients stimulated with thyroliberin were consonant with the results of the thyroliberin test in 25 cases. Thus, for most patients, measurement of a basal TSH concentration evidently will predict their thyroidal status and also the response to thyroliberin, but a few will require additional tests of thyroid function.
Discrepancy between uptake of serum triiodothyronine as measured by albumin and charcoal methods in nonthyroidal illnesses.
Authors: Konno N , Taguchi H , Hagiwara K , Taguchi S , Hatsukaiwa Y , Kumagai M 
Published: January 2020

Abstract
Triiodothyronine (T3) uptake as determined with albumin (AT3U) and with charcoal (CT3U) as binders were compared for patients with low-T3 syndrome. Both T3U values were identical in normal subjects and in patients with thyroidal disorders, pregnancy, low thyroxin-binding globulin (TBG), or acute hepatitis with high concentration of TBG. In the low-T3 syndrome, AT3U was significantly higher than CT3U (38.5 +/- 7.2% vs 29.4 +/- 4.9%, mean +/- SD, n = 37, p less than 0.001), and this difference increased as TBG and albumin concentrations decreased. Decreasing the concentration of TBG and albumin in serum by dilution increased the AT3U more than the CT3U value. Adding albumin to serum decreased AT3U, but not CT3U, when serum TBG and albumin concentrations were low. The free-thyroxin (T4) index as calculated by the AT3U ratio and T4 more accurately reflects the concentration of free T4 in low-T3 syndrome than does the index calculated from the CT3U ratio and T4. Thus AT3U is determined primarily by changes in TBG and albumin concentrations, so that the free-T4 index based on the AT3U ratio and T4 may be more useful than the CT3U method for evaluating free-T4 concentrations in low-T3 syndrome, which frequently has concomitant decreases in TBG and albumin concentrations.
"Fragmented" isoenzymes of alkaline phosphatase in the diagnosis of transient hyperphosphatasemia.
Authors: Schoenau E , Herzog K H , Boehles H J 
Published: January 2020

Abstract
We describe the appearance of "fragmented" isoenzymes of serum alkaline phosphatase (EC 3.1.3.1) in two cases of transient hyperphosphatasemia. We determined the isoenzymes by liquid chromatography, then characterized them by heat inactivation, inhibition with 5 mmol/L L-phenylalanine solution, and electrophoresis on cellulose acetate membranes. We suspect that a virus-induced decrease in clearance of the enzyme from serum is responsible for a similar increase of bone and liver isoenzyme activities and for the presence of these fragmented isoenzymes in transient hyperphosphatasemia.
Multiple myeloma with serum IgM kappa and Bence Jones lambda biclonal gammopathy.
Authors: Graziani M S , Lippi U 
Published: January 2020

Abstract
We report a rare finding: IgM kappa and Bence Jones lambda double gammopathy in serum of a 80-year-old man with untreated symptomatic multiple myeloma. The unusual findings are confined to the laboratory studies demonstrating also a Bence Jones lambda proteinuria, high erythrocyte sedimentation rate (113 mm/h), and anemia. The synthesis of the different light chains seems to occur in separate cellular clones.
Improved fluorescence polarization assay for use in evaluating fetal lung maturity. I. Development of the assay procedure.
Authors: Tait J F , Franklin R W , Simpson J B , Ashwood E R 
Published: January 2020

Abstract
We describe a fluorescence polarization assay for use in predicting fetal lung maturity, which is suitable for the TDx Analyzer (an automated fluorescence polarimeter). The assay requires 0.5 mL of amniotic fluid and approximately 30 min, and involves the fluorophore 1-palmitoyl-2(6-[(7-nitro-2, 1, 3-benzoxadiazol-4-yl)amino]caproyl) phosphatidylcholine. Reproducible polarization measurements depend on proper regulation of incubation time and temperature, but variations in the concentrations of fluorescent probe and amniotic fluid have little effect on measured polarization and therefore little effect on assay precision. Working solutions of the fluorescent probe are stable for at least nine months when stored at -20 degrees C and pH 5. Interferences include erythrocytes, serum, bilirubin, meconium, and lidocaine.
Improved fluorescence polarization assay for use in evaluating fetal lung maturity. III. Retrospective clinical evaluation and comparison with the lecithin/sphingomyelin ratio.
Authors: Ashwood E R , Tait J F , Foerder C A , Franklin R W , Benedetti T J 
Published: January 2020

Abstract
We clinically evaluated, retrospectively, our improved fluorescence polarization assay for fetal lung maturity. The procedure requires 0.5 mL of amniotic fluid and a standard clinical laboratory fluorescence polarimeter (TDx Analyzer, Abbott Laboratories). We measured the L/S ratios for 93 freshly collected amniotic fluids, uncontaminated with blood or meconium, collected within three days of delivery. The fluids were stored frozen for eight to 32 months, then thawed and assayed for net fluorescence polarization. Fourteen of the infants developed respiratory distress syndrome; five, transient tachypnea of the newborn; and 74, no respiratory distress. The polarization assay and lecithin/sphingomyelin ratio had equivalent receiver operating characteristic curves, indicating no difference in their clinical performance. Although a prospective study with fresh amniotic fluid specimens will be necessary to establish a definitive reference range, the present study shows that this assay can be used to rapidly predict fetal lung maturity.
Apolipoprotein E quantified by enzyme-linked immunosorbent assay.
Authors: Bury J , Vercaemst R , Rosseneu M , Belpaire F 
Published: January 2020

Abstract
We developed a sensitive, specific "sandwich"-type enzyme-linked immunosorbent assay in which affinity-purified antibodies are used for coating and also for preparing an antibody-peroxidase conjugate to quantify apolipoprotein E in serum and in its lipoprotein fractions. This technique is rapid (results within 5 h), precise (mean intra- and interassay CVs 4.3 and 8.2%, respectively), accurate, and simple to perform. Sample pretreatment did not enhance apo E immunoreactivity. For 47 normolipidemic subjects, the mean apo E concentration was 38.11 (SD 11.1) mg/L. Above-normal apo E concentrations were measured in all types of hyperlipoproteinemia, especially types III and V. Apo E correlated with triglyceride (r = 0.58) and cholesterol concentrations (r = 0.60). As determined by gel filtration, hypertriglyceridemia was associated with a redistribution of apo E towards the triglyceride-rich lipoprotein fractions, which contained 77.1% (SD 16.8%) of total plasma apo E in Fredrickson type V patients, compared with 12.5% (SD 6.3%) in normal persons.
Creatine kinase: reassessment of optimal concentrations for adenosine-5'-diphosphate and magnesium.
Authors: Lahet C , Vialle A , Maire I , Parrin B , Steghens J P , Mathieu M 
Published: January 2020

Abstract
Whereas univariate studies led to an European agreement for the choice of optimal reagent concentrations of 2 mmol/L for ADP and 10 mmol/L for Mg2+ for determining creatine kinase (EC 2.7.3.2) activity in serum, whatever its isoenzyme pattern, the results of our bivariate study led us to recommend higher optimal concentrations: 4.1 to 4.7 mmol/L for ADP and 22 mmol/L for Mg2+. The zone of maximal activity was in fact a broad plateau such that more than 99% of maximal enzyme activity was attained at ADP concentrations between 3 and 5 mmol/L and Mg2+ concentrations between 17 and 26 mmol/L. Under these new conditions the maximum activity measured was modestly increased (about 10%) over the previously recommended method but the assay could be expected to be more resistant to the variations of ADP and Mg2+ concentrations. It may become necessary to modify the European recommended method.
Differentiating muscle damage from myocardial injury by means of the serum creatine kinase (CK) isoenzyme MB mass measurement/total CK activity ratio.
Authors: el Allaf M , Chapelle J P , el Allaf D , Adam A , Faymonville M E , Laurent P , Heusghem C 
Published: January 2020

Abstract
We immunoenzymometrically measured creatine kinase (CK) isoenzyme MB in extracts of myocardium and in homogenates of five different skeletal muscles. CK-MB concentrations in the former averaged 80.9 micrograms/g wet tissue; in the skeletal muscles it varied widely, being (e.g.) 25-fold greater in diaphragm than in psoas. CK-MB in skeletal muscles ranged from 0.9 to 44 ng/U of total CK; the mean for myocardium was 202 ng/U. In sera from 10 trauma and 36 burn patients without myocardial involvement, maximum ratios for CK-MB mass/total CK activity averaged 7 (SEM 1) ng/U and 18 (SEM 6) ng/U, respectively. Except for an infant (220 ng/U), the highest ratio we found for serum after muscular damage was 38 ng/U. In contrast, the mean maximum ratio determined in 23 cases of acute myocardial infarction exceeded 200 ng/U. Among seven determinations performed 8 to 32 h after onset of symptoms, each infarct patient demonstrated at least one ratio greater than or equal to 110 ng/U. Ratios observed after infarct were unrelated to treatment received during the acute phase. We propose a CK-MB/total CK ratio of 80 ng/U as the cutoff value for differentiating myocardial necrosis from muscular injury.
Laboratory tests in the differential diagnosis of hyperamylasemia.
Authors: Tietz N W , Huang W Y , Rauh D F , Shuey D F 
Published: January 2020

Abstract
We evaluated the clinical utility of some recently developed laboratory methods, including total amylase by three methods; isoamylase by inhibition and isoelectric focusing; lipase by pH-Stat and turbidimetry; and immunoreactive trypsin. All methods correlated highly positively with hyperamylasemia due to primary acute pancreatitis. Pancreatic-type isoamylase determinations have the greatest clinical usefulness, because total amylase, lipase, and immunoreactive trypsin are increased in a relatively high percentage of other abdominal diseases. Increases in the last-mentioned enzymes in nonpancreatic abdominal disease may be the result of injuries to the pancreas secondary to the primary disease, which are being detected with these highly sensitive methods. Because of the high clinical sensitivity of lipase and immunoreactive trypsin determinations, a normal result tends to exclude acute pancreatitis. Hyperamylasemia seen in lung carcinoma is due to increase in an amylase isoenzyme similar to the salivary-type amylase. The method for pancreatic-type isoamylase based on selective inhibition is satisfactory for routine clinical laboratory use.
Screening and quantification of hypnotic sedatives in serum by capillary gas chromatography with a nitrogen-phosphorus detector, and confirmation by capillary gas chromatography-mass spectrometry.
Authors: Soo V A , Bergert R J , Deutsch D G 
Published: January 2020

Abstract
We describe a quantitative screen for hypnotic-sedative drugs in which we use capillary gas chromatography with a nitrogen-phosphorus detector (GC/NPD) as the primary method and capillary gas chromatography-mass spectrometry (GC-MS) for confirmation. GC retention times of the acid-extracted underivatized drugs were stable (CVs less than 1%), and the detector response varied linearly over a 20-fold concentration range with a mean correlation coefficient for 11 drugs of 0.989. The limits of detection were satisfactory (0.5 mg/L in a 0.5-mL serum sample and 1-microL injection volume), as were precision (average CV 5.2% within day, 6.4% between day). The complementary use of capillary GC-MS not only unambiguously confirms presumptive peaks identified by GC, but also prevents reports of false positives and identifies compounds not included in the quantitative GC screen that may be listed in the GC-MS library.
Spectrophotometry of carnitine in biological fluids and tissue with a Cobas Bio centrifugal analyzer.
Authors: Cederblad G , Harper P , Lindgren K 
Published: January 2020

Abstract
A spectrophotometric method for carnitine has been adapted to the Cobas Bio centrifugal analyzer. The addition of carnitine to a system containing carnitine acetyltransferase (EC 2.3.1.7) and acetyl-CoA gives rise to the formation of CoA. The system is coupled to 5,5'-dithiobis(2-nitrobenzoate) (DTNB). Assay response varied linearly with concentration of carnitine over a wide concentration range. The total CV was 5.5% for a carnitine concentration in serum of 58.0 mumol/L. Analytical recovery of carnitine added to a serum sample was 93%. No interference was found in icteric, not grossly hemolyzed, lipemic, or uremic sera. Comparison with a radioenzymatic method showed that results correlated well (r greater than 0.965) but the present method gave values proportionally greater by 10 to 25% for samples of plasma, dialysis fluid, urine, and muscle tissue. Advantages over the original spectrophotometric assays involving DTNB include low reagent costs, rapidity, simplicity, and reproducibility. However, this modification is not as sensitive and probably not as specific as the radioenzymatic methods.
Clustering of serum calcium and magnesium concentrations in siblings.
Authors: Payne R B , Jones D P , Walker A P , Evans R T 
Published: January 2020

Abstract
Concentrations of both serum calcium, adjusted for albumin, and serum magnesium of siblings from 23 families were found to cluster around different concentrations within the normal reference interval. Variation between families accounted for 37% of the total variation in calcium and 28% of that in magnesium. A disturbance of serum calcium or magnesium homeostasis in an individual resulting in an altered serum concentration that remains within the reference interval might be recognized by examining values in siblings.
Is standardization more important than methodology for assay of total protein in cerebrospinal fluid?
Authors: Gerbaut L , Macart M 
Published: January 2020

Abstract
Four manual micromethods for protein determination, two turbidimetric (trichloroacetic and sulfosalicylic acid-sodium sulfate) and two colorimetric (Lowry and Coomassie Brilliant Blue--sodium dodecyl sulfate, CBB-SDS) were used to compare the standard curves for total protein (0.30 to 3 g/L) produced with three reference materials: bovine serum albumin, human serum albumin, and diluted human serum. We measured the apparent protein content of a sample of pooled human cerebrospinal fluid by all four methods and with use of all three standards. The only reference material that gave similar results with all four methods was diluted human serum; the CBB-SDS was the only method that gave identical results with all three reference materials. We then measured the protein concentration of 28 individual cerebrospinal fluid samples by the four methods, with diluted human serum as standard. Results by all methods correlated well, but only the sulfosalicylic acid and the CBB-SDS methods gave equivalent results. We conclude that the choice of standard is more important than the method used. However, the CBB-SDS method may be the preferred method because it produced identical standard curves with all three protein standards.
The alkaline reducing activity of glycated serum proteins and its relevance to diabetes mellitus.
Authors: Johnson R N , Baker J R 
Published: January 2020

Abstract
We investigated the ability of the fructosamine assay to detect glycation of serum proteins. We incubated both whole human serum and serum protein fractions in vitro with [14C]glucose, and analyzed for reducing activity and for uptake of 14C by protein. In all experiments, the reducing activity increased linearly with time for seven days and was correlated with 14C uptake (r = 0.94-0.98). Protein ketoamines were about fivefold more actively reducing than equimolar concentrations of deoxymorpholinofructose, the fructosamine standard, which explains why values for fructosamine in serum are higher than the expected concentration of protein ketoamines. We also used [14C, 2-3H]glucose to assess the contribution of the aldimine component to 14C uptake. Whole human serum and albumin incubated with [14C, 2-3H]glucose showed little uptake of 3H in relation to 14C. We conclude that glycated protein can be simply and reliably quantified by the fructosamine assay, and we discuss the relevance of this conclusion to the monitoring of diabetes.
Relation between plasma creatinine and body size.
Authors: Swaminathan R , Ho C S , Chu L M , Donnan S 
Published: January 2020

Abstract
We studied the relationship between creatinine concentration in plasma and body size in 673 healthy individuals (385 women, 288 men). Weight, height, and skinfold thickness were measured and blood was sampled (after a short fast) for estimations of urea and creatinine in plasma. Lean body mass was calculated according to Durnin and Wormsley (Br J Nutr 1974; 32:77-97). Concentrations of urea and creatinine in plasma were significantly lower in women than in men and were significantly correlated with age in both sexes. For neither sex was there a significant correlation between lean body mass and creatinine concentration, even after we took age into account either by multiple linear-regression analysis or by considering subjects at decade intervals.