bluuebunny/crossref_metadata_2025 huggingface dataset:
Concentrations of lipids and apolipoproteins in patients with clinically well-controlled insulin-dependent and non-insulin-dependent diabetes.
Authors: Joven J , Vilella E , Costa B , Turner P R , Richart C , Masana L
Published: January 2020

The triglyceride and cholesterol content of total, very-low-, intermediate-, low-, and high-density lipoproteins, and of apolipoproteins (apo) Al, All, B, Cll, Clll, and E were determined in plasma from 107 patients with clinically well-controlled diabetes and from 66 age- and weight-matched healthy normal subjects. The diabetic patients were separated into two groups: those with insulin-dependent diabetes mellitus (IDDM, type 1, n = 24) and those with non-insulin-dependent diabetes mellitus (NIDDM, type 2, n = 83). The latter group contained two subgroups: those treated by diet (type 2d, n = 42) or by insulin (type 2i, n = 41). High-density lipoprotein cholesterol was increased in IDDM patients, and decreased in NIDDM patients relative to control subjects. Mean apo Al values in IDDM patients were higher than in their respective controls and in NIDDM patients. Concentrations of apo B, Clll, and E were higher in all diabetic patients than in the healthy controls, but those of apo Cll did not differ statistically between diabetics and nondiabetics. Although total plasma cholesterol and triglyceride concentrations were apparently near normal values in patients with good glycemic control, we found a persistent increase of intermediate-density lipoproteins (remnants) in all the diabetic groups studied. This factor may be related to the perceived increased cardiovascular risk in these individuals.
A simplified strategy for testing thyroid function.
Authors: Beaman J M , Woodhead J S
Published: January 2020

We assessed a new strategy for thyroid-function testing that involves simultaneous measurement of free thyroxin and thyrotropin, both in singletons, with chemiluminescent assays. Using our current strategy of measuring free thyroxin as a first-line test with selected back-up testing, the results show that, of 810 patients without previous thyroid disease, 445 received back-up tests. Of these, 345 were euthyroid, whereas 63 classified as euthyroid and not selected for further testing in fact had abnormal back-up test results. Evidently the simultaneous measurement of free thyroxin and thyrotropin with the "Magic Lite" technology greatly improves diagnostic efficiency compared with this current strategy.
Concentrations of some trace elements (Se, Zn, Cu, Fe, Mg, K) in blood and heart tissue of patients with coronary heart disease.
Authors: Oster O , Dahm M , Oelert H , Prellwitz W
Published: January 2020

We measured Se, Zn, Fe, Cu, Mg, and K in blood and heart tissue of patients with coronary heart disease. Such patients have subnormal selenium concentrations in serum, whole blood, and (calculated per gram of hemoglobin) erythrocytes. Concentrations of zinc and copper in serum were also subnormal in these patients. Heart tissue collected from these patients during bypass surgery was analyzed for Se, Zn, Fe, Cu, Mg, and K; results are expressed in terms of wet weight and in relation to nitrogen and phosphorus content. Concentrations of these elements in blood are correlated with those in heart tissue. Selenium concentrations in serum correlated positively with those in tissue but not with those in erythrocytes. We found no association between concentrations of zinc, iron, copper, magnesium, and potassium in serum and the corresponding concentrations in heart tissue. There was a moderately positive correlation between the concentration of ferritin in serum and that of iron in tissue. We conclude that the turnover rate for selenium in tissue is similar to that in serum but greater than that for erythrocyte selenium. The concentrations of these six elements in heart tissue are partly correlated with the ejection fraction of the left ventricle.
Proficiency testing on drugs of abuse: one year's experience in Spain.
Authors: Segura J , de la Torre R , Congost M , Camí J
Published: January 2020

The need for external quality control for drugs-of-abuse urinalysis has long been recognized. Based on experiences in other countries, a proficiency testing program has been introduced recently in Spain. Sterile urine samples containing different concentrations of drugs and metabolites are analyzed by participating laboratories four times a year. Comprehensive educational reports reviewed by an advisory committee are released after each batch analysis. The first year's results verify (a) a beneficial influence of the program in regard to reducing errors when adequate techniques are used, (b) the need for using confirmatory techniques, and (c) the importance of experience and laboratory resources for optimizing results. The educational aspects of the program for the second year are stressing especially the in situ training of analysts and the supply of solutions of drugs and metabolites to be used as reference standards.
Simplified method for screening populations at risk for transthyretin Met30-associated familial amyloidotic polyneuropathy.
Authors: Saraiva M J , Alves I L , Costa P P
Published: January 2020

This simple, reliable method for detecting the transthyretin-methionine30 [TTR(Met30)] mutation, found in patients with familial amyloidotic polyneuropathy (FAP), is based on production of an extra peptide fragment when the mutant TTR is treated with cyanogen bromide (CNBr). After electrophoresis of whole serum and excision of the TTR (prealbumin) band, the TTR-containing gel is incubated with CNBr, subjected to sodium dodecyl sulfate/polyacrylamide gel electrophoresis, and stained with silver to determine whether an abnormal CNBr fragment (residues 31-127) is present. Results can be obtained within two days. Several samples can be processed simultaneously, and no unusual equipment or reagents are required. The procedure is suitable for routine diagnosis of FAP and for epidemiological studies.
Exposure to environmental tobacco smoke measured by cotinine 125I-radioimmunoassay.
Authors: Knight G J , Palomaki G E , Lea D H , Haddow J E
Published: January 2020

We describe a polyclonal-antiserum-based 125I-radioimmunoassay for cotinine that is suitable for measuring nonsmokers' passive exposure to tobacco smoke in the environment. The standard curve ranged from 0.25 to 12.0 micrograms/L, with an estimated lower limit of sensitivity of 0.2 microgram/L (95% B/Bo = 0.2 microgram/L; 50% B/Bo = 4.0 micrograms/L). The median within-assay CVs for patients' samples with cotinine values from 0.4 to 1.3, 1.4 to 2.4, 2.5 to 4.6, and 4.7 to 15.6 micrograms/L were 13.9%, 7.2%, 5.1%, and 5.7%, respectively. Between-assay CVs for two quality-control sera with average values of 1.53 and 3.68 micrograms/L were 14.3% and 7.8%, respectively. Analytical recoveries of cotinine from smokers' sera diluted in zero calibrant ranged from 91% to 116%. Cotinine values determined on 79 paired sera and urines from nonsmokers showed significant correlation with self-reported exposure to environmental tobacco smoke (r = 0.49, P less than 0.001 for sera; r = 0.57, P less than 0.001 for urine). The log of the values for serum and urine cotinine were also significantly correlated (r = 0.85, P less than 0.001). Evidently, polyclonal antiserum can be used to develop a cotinine assay for measuring exposure to environmental tobacco smoke that compares well with that described for monoclonal-based assays.
Thin-layer chromatography of free porphyrins for diagnosis of porphyria.
Authors: Henderson M J
Published: January 2020

In this simple thin-layer chromatographic (TLC) technique for evaluating porphyrin excretion, porphyrins are extracted from urine or feces, then separated on silica-gel TLC plates. The distinct porphyrin bands are observed by viewing the plates under long-wave fluorescent light. Positive screening tests can readily be confirmed or rejected, and a more comprehensive investigation confidently undertaken.
Effects of therapeutic coronary reperfusion on aspartate aminotransferase isoenzymes in sera of patients with acute myocardial infarction.
Authors: Panteghini M , Pagani F , Cuccia C
Published: January 2020

We examined the kinetics of the catalytic activities of aspartate aminotransferase (AST, EC 2.6.1.1) isoenzymes in serum of 28 patients with myocardial infarction who were to receive either intracoronary urokinase--reperfusion angiographically proved--or conventional therapy (control group). Cytosolic (soluble) AST (s-AST) activity in serum increased rapidly immediately after recanalization, reaching a maximum 12 h after the onset of infarction. In the control group, this peak was reached 28 h after the onset (P less than 0.001). Peak s-AST activity was similar in the two groups. Peak activity and peak time for mitochondrial AST (m-AST) were the same for the two groups of patients; intervention that affects myocardial perfusion caused only a slight additional increase in m-AST activity in the early post-infarct period. There may be advantages to measuring m-AST, which is briefly influenced by reperfusion, instead of the usual cytosolic enzymes for assessment of myocardial damage in patients with myocardial infarction treated with thrombolytic therapy.
Correlation of HbA1C, glycated serum proteins and albumin, and fructosamine with the 24-h glucose profile of insulin-dependent pregnant diabetics.
Authors: Suhonen L , Stenman U H , Koivisto V , Teramo K
Published: January 2020

To assess the value of various methods for long-term follow-up of diabetic patients, we compared the concentrations of fructosamine in serum with those of various glycated proteins: hemoglobin (HbA1C), total serum proteins (G-prot), and albumin (G-alb), assayed in 30 pregnant insulin-dependent diabetics every two weeks after initial determination of a 24-h blood glucose profile. HbA1C correlated best with the 24-h glucose profile during the succeeding 10-35 days (r = 0.65-0.68, P less than 0.001). G-prot and G-alb correlated nearly as well as HbA1C 10-20 days after the glucose profile (r = 0.54-0.64, P less than 0.01-0.001), but only weakly after 25-35 days. Values for fructosamine did not correlate significantly with the glucose profile 10-35 days after it (r = 0.23-0.36). Evidently the fructosamine assay is not an adequate alternative to HbA1C, G-alb, or G-prot as an index to long-term control of blood glucose in such patients.
Investigation of sex-hormone binding globulin interference in direct radioimmunoassays for testosterone and estradiol.
Authors: Masters A M , Hähnel R
Published: January 2020

The aim of this study was to find reasons for the interference of sex-hormone binding globulin (SHBG) in direct radioimmunoassays (RIAs) for testosterone and estradiol. 125I-labeled testosterone and estradiol were compared with 3H-labeled testosterone and estradiol for their affinity to SHBG. The 3H-labeled steroids bound far more avidly to SHBG than did the corresponding 125I-labeled steroids. The SHBG concentration in the standard matrix of two kits was significant. Finally, 3H-labeled steroids were compared with 125I-labeled steroids for their affinity to the antibody supplied with the kits. The 125I-labeled steroids bound more avidly than did the 3H-labeled steroids to the corresponding antibodies. Direct testosterone and estradiol results would be influenced according to the SHBG in the sample, as observed.
Generalized likelihood ratio concept and logistic regression analysis for multiple diagnostic categories.
Authors: Reibnegger G , Fuchs D , Hausen A , Werner E R , Werner-Felmayer G , Wachter H
Published: January 2020

Albert (Clin Chem 1982;28:1113-9) has proposed estimation of likelihood ratios by logistic regression analysis. The usual likelihood-ratio approach for estimation of post-test probability of disease from sensitivity and specificity data of a diagnostic test has been extended by Birkett (J Clin Epidemiol 1988; 41:491-4) for situations with more than two diagnostic categories. We suggest here a combination of these ideas, demonstrating this by a re-evaluation of previously published data on the validity of neopterin as a tool for differential diagnosis between chronic non-A, non-B hepatitis and fatty liver. Analysis of neopterin data in combination with the ratio between serum concentrations of aspartate aminotransferase and of alanine aminotransferase yielded a good discrimination between three mutually exclusive diagnostic categories, namely, fatty liver and chronic persistent and chronic aggressive non-A, non-B hepatitis. The approach is flexibly applicable to situations with different pre-test probabilities. The sum of estimated post-test probabilities deviates slightly from the sum of pre-test probabilities. This deviation is a function of the coefficients obtained in logistic regression, and an analytical expression for the deviation is given. The generalized likelihood-ratio approach appears promising in complex diagnostic situations when multiple diagnostic tests are available.
The use of GC/IR/MS for high-confidence identification of drugs.
Authors: Duncan W P , Deutsch D G
Published: January 2020

We describe the use of a combined gas chromatographic/infrared/mass spectrometric system to identify some common, clinically important drugs. Sensitivity for the serially configured combined system is demonstrated to be in the low nanogram range for strong infrared-absorbing compounds. Linearity for cocaine in the infrared detector was shown to have a correlation coefficient of 0.9914. Vapor-phase infrared spectra are shown to be very reproducible, which is important in identifying drugs such as the barbiturates. Finally, the two completely independent principles of infrared and mass spectral detection lend significant confidence to the correct identification of the various drugs from a single injection of sample.
Analysis of supplemented vitamin K1(20) in serum microsamples by solid-phase extraction and narrow-bone HPLC with multichannel ultraviolet detection.
Authors: Kirk E M , Fell A F
Published: January 2020

A sensitive method for the determination of vitamin K1(20) in serum microsamples (50 microL) has been developed, utilizing solid-phase extraction with C8 Bond-Elut columns and reversed-phase narrow-bore high-performance liquid chromatography [2.1 mm (i.d.), column] with a nonaqueous eluent. Recovery from serum (49 ng/mL) was 76% (n = 2). Peak homogeneity was assessed by photodiode array detection with absorbance ratio, spectral normalization, and transformation to the first- and second-derivative chromatograms. Calibration data at 248 nm over two ranges (20-200 ng/mL, 200-4000 ng/mL) varied linearly with concentration and were suitable for studies of vitamin K1 supplementation. By comparison with conventional columns, sensitivity was increased twofold.
The continuing need for quality assessment of cyclosporine measurement.
Authors: Johnston A , Marsden J T , Holt D W
Published: January 2020

The returns from the United Kingdom Cyclosporin Quality Assessment Scheme were analyzed for the period June 1987 to August 1988. During this time the number of laboratories in the Scheme increased from 102 to 124 and the proportion of laboratories using nonspecific assay methods declined, as did the proportion of them measuring cyclosporine in plasma. Seven different methods were used to measure the drug in blood, and the seven methods gave seven different results when used to measure patients' samples. The results, from lowest to highest, differed by a factor of approximately 3.4. The within-assay coefficient of variation (CV) was acceptable for all methods, but the between-assay and between-center CVs were poor. HPLC gave higher CVs than did the immunoassays.
Issues in methodology and applications for therapeutic monitoring of antidepressant drugs.
Authors: Orsulak P J , Haven M C , Burton M E , Akers L C
Published: January 2020

Measurement of antidepressant drugs in serum provides a useful indicator of optimal dosage and can enable the clinician, in certain circumstances, to easily adjust dosages for individual differences in drug metabolism, alterations in the concentration in serum owing to drug interactions, or failure to achieve an adequate concentration in serum because of noncompliance. Practical therapeutic monitoring of antidepressants, however, is still complicated by a lack of suitable reference methodology or established assay-performance criteria and the diversity of analytical techniques. We review here several contemporary methods of analysis for the tricyclic antidepressant drugs--including gas chromatography with a nitrogen-specific detector, HPLC, and immunoassays--that are available for toxicology screening or for quantifying the most widely monitored tricyclic drugs. We also present an overview of current laboratory issues and practical considerations facing those who analyze for antidepressant drugs.
An update on digoxin.
Authors: Stone J A , Soldin S J
Published: January 2020

This review deals briefly with recent developments in the therapeutic drug monitoring of digoxin. Strategies for decreasing the interference by digoxin metabolites, digoxin-like factors, and spironolactone metabolites in immunoassays of digoxin are discussed. Other issues addressed include the development of alternative methods of analysis, such as receptor assays and "high-pressure" liquid chromatography; digoxin-like factors in hypertension; drug-drug interactions; redistribution of digoxin stores in the body; and forensic considerations.
The relevance of pharmacokinetics to monitoring new antiarrhythmics.
Authors: Holt D W , Johnston A
Published: January 2020

The application of selective and sensitive methodology to the investigation of the pharmacokinetics of new antiarrthythmic drugs is described. The value of these data in the context of routine measurements as a guide to therapy is discussed. In particular, specific case histories that demonstrate the considerable within- and between-subject variation in pharmacokinetic parameters are cited and used to illustrate the potential benefits of drug monitoring. We conclude that studies designed to elucidate the pharmacokinetics of these drugs in a variety of clinical settings can be a valuable guide to assessing the patient groups for whom routine monitoring would be of particular benefit when the drugs are in general clinical use.
Microplate measurement of urinary albumin and creatinine.
Authors: Magnotti R A , Stephens G W , Rogers R K , Pesce A J
Published: January 2020

We describe microplate methods for measurement of human urinary albumin (HUA) by competitive enzyme-linked immunosorbant assay (ELISA) and creatinine with a modified commercial enzymatic kit. Incorporation of substrate mixing into the competitive ELISA changes the dynamic absorbance-concentration response, greatly simplifying calculations and improving sensitivity and accuracy. Measurement of creatinine in urine and plasma samples with a commercially available enzymatic kit modified for analysis by use of an inexpensive microplate reader produced values comparable in precision and accuracy to those obtained by an automated kinetic Jaffé method.
Use of a dual-precipitation procedure for measuring high-density lipoprotein 3 (HDL3) in normolipidemic serum.
Authors: Cloey T A , Bachorik P S
Published: January 2020

We compared results by a dual-precipitation method (J Lipid Res 1982;23:1206-23) for measuring high-density lipoprotein 3 (HDL3) cholesterol with those by ultracentrifugation at d 1.125, using 56 fresh and 105 frozen-stored serum samples. For both methods, HDL2-cholesterol was calculated as the difference between total HDL-cholesterol and HDL3-cholesterol. In general, for pooled serum samples, agreement was closest with ultracentrifugation when we used a dextran sulfate concentration of 5.0 mg/L to precipitate the HDL2-rich fraction, although the optimal concentration varied from 3.0 to 6.8 mg/L for different pools. For individual samples, the values for HDL3 by dual precipitation averaged 12.8% lower than by ultracentrifugation. The coefficients of correlation between the two methods were HDL3, r = 0.70; and HDL2, r = 0.92. The dual-precipitation method reflected the expected sex-related differences in HDL2-cholesterol concentration and inverse relationship with triglyceride concentration.
Evidence that the oral glucose-tolerance test does not provide a uniform stimulus to pancreatic islets in pregnancy.
Authors: de Leacy E A , Cowley D M
Published: January 2020

Fifty consecutive pregnant patients referred for a glucose-tolerance test were classified on the basis of increasing (n = 20) or decreasing (n = 28) hematocrit after an oral 75-g glucose load. (The hematocrit did not change in the other two patients.) Patients with increasing hematocrit, a response previously seen in patients with the dumping syndrome, showed significantly flatter increases in glucose concentrations in plasma after the load. The mean decrease in the concentration of phosphate in plasma, measured as an index of glucose uptake by cells, was significantly less (P less than 0.05) 2 h after the load in the group with flatter glucose responses, suggesting that the flat response is ascribable to poor glucose absorption rather than to an exaggerated insulin response. These results indicate that the oral glucose-tolerance test stresses the pancreatic islets differently in different pregnant subjects, owing to individual variations in the gastrointestinal handling of the glucose load. Consequently, patients may give a "normal" result who might otherwise become hyperglycemic after normal meals. We suggest that alternative screening procedures be investigated to assess pregnant patients postprandially.
Interaction of immobilized anti-salivary amylase antibody with human macroamylases: implications for use in a pancreatic amylase assay to distinguish macroamylasemia from acute pancreatitis.
Authors: Mifflin T E , Forsman R W , Bruns D E
Published: January 2020

We examined the ability of an immobilized antibody to salivary amylase (Clin Chem 1985;33:1283-8) to react with amylase in macroamylasemic sera. The antibody removed 50% (SD 23%) of the total amylase activity from 39 macroamylase sera, a percentage indistinguishable (P greater than 0.75) from the percentage removed from concurrently analyzed sera from healthy volunteers (49%, SD 11%). Electrophoretic analysis of 23 macroamylasemic sera revealed that the antibody removed only part of the macroamylase band(s) in 71% of the cases. We conclude that the mean isoenzyme composition of the macroamylase complexes is essentially identical to the mean isoenzyme distribution in normal sera (i.e., about half salivary and half pancreatic amylase). Further, the immobilized antibody can be used to distinguish most patients with macroamylasemia from those with acute pancreatitis, because sera from the latter contain an increased proportion (greater than 80%) of pancreatic amylase.
Direct and indirect techniques for free thyroxin compared in patients with nonthyroidal illness. II. Effect of prealbumin, albumin, and thyroxin-binding globulin.
Authors: Csako G , Zweig M H , Glickman J , Ruddel M , Kestner J
Published: January 2020

We studied the correlation of thyroxin (T4)-binding proteins with the apparent free T4 (FT4) in 101 patients with nonthyroidal illness (NTI). Most patients (95%) were seriously ill at the time of blood collection. Concentrations of T4-binding prealbumin (transthyretin), albumin, and T4-binding globulin (TBG) often were low in the sera of these patients. Albumin was the most frequently subnormal, TBG the least. FT4 in serum was determined by five methods represented in 16 different assays. With few exceptions, analog (one-step) FT4 RIAs--both the binding-rate-based RIA and the related FT4 indices (calculated from triiodothyronine-macroaggregated albumin uptake and total T4)--and T4/TBG ratios correlated positively and usually highly significantly (P less than 0.01) with concentrations of prealbumin, albumin, and TBG. Equilibrium dialysis values for FT4 did not correlate with prealbumin concentrations but showed a weakly (P less than 0.03) positive association with albumin and a highly significant (P less than 0.002) positive correlation with TBG. Of the three two-step FT4 RIAs tested, the only statistically significant but weakly (P less than 0.02) positive correlation with T4-binding proteins was between Spiria FT4 and TBG. Thus, in these NTI patients, FT4 estimates vary with methodology and, to a lesser extent, with the particular assay used. The results from two-step FT4 RIAs are least associated with binding protein concentrations.
Decreased immunoreactivity and binding activity of corticosteroid-binding globulin in serum in septic shock.
Authors: Pugeat M , Bonneton A , Perrot D , Rocle-Nicolas B , Lejeune H , Grenot C , Déchaud H , Brébant C , Motin J , Cuilleron C Y
Published: January 2020

To investigate the mechanism(s) responsible for the depletion of corticosteroid-binding globulin (CBG) activity in serum in septic shock, we developed a radioimmunoassay (RIA) for human CBG, using a monospecific antiserum to human CBG raised in rabbits. CBG was purified from pooled human serum by precipitation with ammonium sulfate and successive affinity chromatography treatments on corticosterone-Sepharose and concanavalin A-Sepharose. Final purification was achieved by HPLC on a diethylaminoethyl-PW (polymer matrix) ion-exchange column. Typical standard curves established for the CBG immunoassay showed parallelism for pure CBG and serial dilutions of sera from patients with septic or nonseptic shock and from healthy controls. Measurements of CBG by RIA showed a significantly (P less than 0.001) lower CBG concentration in patients with septic shock (22.9 +/- 5.9 mg/L, mean +/- SD; n = 23) than in controls (39.9 +/- 6.5 mg/L, n = 21) or in patients with nonseptic shock (33.3 +/- 6.5 mg/L, n = 12). The correlation between the concentrations determined by RIA and the CBG binding capacity was significant (r = 0.619, P less than 0.001, n = 33). The electrophoretic mobility of CBG was similar in sera from septic shock patients and normal subjects (Rf = 0.52-0.56). This suggests that the depletion of the corticosteroid-binding activity in serum during septic shock is associated with a decreased amount of CBG.
Lipase activity measured in serum by a continuous-monitoring pH-Stat technique--an update.
Authors: Tietz N W , Astles J R , Shuey D F
Published: January 2020

Using recent knowledge regarding the roles of colipase, bile acids, Ca2+, and emulsifiers, we optimized a previously published pH-Stat method for lipase (EC 3.1.1.3) activity measurements. The recommended assay conditions are: olive oil/triolein, 100 mL/L; sodium glycocholate, 35 mmol/L; Ca2+, 8.5 mmol/L; and colipase, 6.0 mg/L. The sample volume is 0.10 mL, the reaction pH 9.0, the temperature 30 degrees C, and the concentration of titrant 15 mmol/L. Hydroxypropyl methylcellulose, 20 g/L, replaces acacia as emulsifier to avoid inhibition by excess Ca2+. The standard curve is linear to greater than 4566 U/L. The reference interval with olive oil as substrate is 30-235 U/L. Lipase activities with triolein substrate are 9.9% greater than with olive oil. Interference by pancreatic carboxylesterase (EC 3.1.1.1) activity is inhibited by incubating the sample with diisopropylfluorophosphate. Results correlate well with those by the optimized SingleVial method of Boehringer Mannheim Diagnostics (r = 0.997) and the immunochemical assay of Beckman Instruments, Inc. (r = 0.995). Correlation with the aca method (E.I. DuPont de Nemours & Company) is less satisfactory (r = 0.892), probably owing to lack of colipase in the latter method.
Quantification of biotin in serum by competition with solid-phase biotin for binding to peroxidase-avidin conjugate.
Authors: Hansen S I , Holm J
Published: January 2020

We have developed a simple, fast, accurate, and reproducible method--an Enzyme-Linked Ligand Sorbent Assay (ELLSA)--for quantifying biotin without the use of isotopes and immunological reagents. The analytical principle is based on the competition between biotin of the sample and immobilized biotin, i.e., biotinylated bovine serum albumin coated onto immunoplates, for binding to horseradish peroxidase (EC 1.11.1.7)-avidin conjugate. The amount of conjugate bound to immobilized biotin is subsequently measured.
DNA fingerprinting.
Authors: Cawood A H
Published: January 2020

Hypervariable tandem-repetitive minisatellite regions of human DNA can be used to generate individual-specific DNA fingerprints. Validation studies have demonstrated the reliability of the analysis, the mode of inheritance of the minisatellites, and the unparalleled degree of individual specificity. The uses of hypervariable probes in forensic biology, paternity testing, and the resolution of a wide range of problems in genetics, molecular biology, population biology, and medicine are illustrated.
Enzyme immunoassay system for panel testing.
Authors: Donohue J , Bailey M , Gray R , Holen J , Huang T M , Keevan J , Mattimiro C , Putterman C , Stalder A , Defreese J
Published: January 2020

An immunoassay system based on enzyme immunoassay technology has been developed for quantitative panel testing. The system includes test card disposables, reagents, and an instrument. Patients' samples are processed semiautomatically in the instrument with minimum user intervention. The test card has multiple test areas at individual locations on a membrane solid phase so that simultaneous determinations from a single specimen are possible. Each panel also includes positive and negative reagent procedural controls. Factory-determined calibration curves for each analyte are provided in barcode form with each test kit. The reagents include a specimen dilution buffer, enzyme conjugate, and precipitogenic substrate. Up to 10 test cards at a time can be processed in random-access and continuous-access modes, with automated agitation of sample and reagents over the solid phase, temperature-controlled incubation, and membrane washing and reading, data reduction, and printout of results. The optical reader measures diffuse reflectance and features source intensity and wavelength compensation.
Low-normal concentrations of free thyroxin in serum in late pregnancy: physiological fact, not technical artefact.
Authors: Ball R , Freedman D B , Holmes J C , Midgley J E , Sheehan C P
Published: January 2020

Free thyroxin (FT4) concentrations, total thyroxin/thyroxin-binding globulin (T4/TBG) ratios, and thyrotropin (TSH) and albumin concentrations were measured in serum in a longitudinal study in each of the three trimesters of 25 normal pregnancies. In late pregnancy, FT4 estimates by assays reputedly either affected or unaffected by albumin were in the lower half of the reference range for nonpregnant subjects. T4/TBG ratios and albumin concentrations were similarly lower. FT4 overall was significantly (P less than 0.001) correlated with these latter two values. Serum TSH concentrations increased as FT4 declined in late pregnancy. Nonesterified fatty acid (NEFA) concentrations were too low to displace T4 from its binding proteins and were not correlated with other measurements. Within any one of the trimesters, FT4 and T4/TBG were independent of variations in TBG or albumin concentrations. This implies that lower FT4 concentrations in late pregnancy are real, merely coinciding with parallel decreases in albumin. They are not artefacts of albumin-affected assays.
Measuring tissue factor (factor III) activity in plasma.
Authors: Fukuda C , Iijima K , Nakamura K
Published: January 2020

This is a method for measuring tissue factor (TF, Factor III, tissue thromboplastin) activity in plasma by using a chromogenic substrate. As pretreatment, the euglobulin fraction of plasma was prepared by removing endogenous inhibitors and heated at 60 degrees C for 3 min to remove fibrinogen. This allowed us to measure the low TF activity in plasma that could not otherwise be measured. Neither phospholipids nor coagulation factors VII, IX, X, or Xa in the samples interfere. Within-run and day-to-day reproducibility were both good. The mean value obtained by this method for normal persons was 1.02 (SD 0.91) arbitrary units/L. A markedly high plasma TF activity of 20 arb. units/L or more was observed in patients with some types of disseminated intravascular coagulation.
Fully automated fluorescence assay for determining total homocysteine in plasma.
Authors: Refsum H , Ueland P M , Svardal A M
Published: January 2020

Homocysteine exists in human plasma as various (mixed) disulfides. Most plasma homocysteine (about 70%) is protein bound, probably via a disulfide bond to albumin, whereas homocysteine-cysteine mixed disulfide is the predominating form in the free fraction. We here present a method for the determination of total homocysteine, which includes both fractions. Plasma was initially treated with sodium borohydride to reduce the disulfide bonds, and the liberated thiols were derivatized with monobromobimane. The derivatized sample, still containing the plasma proteins, was injected onto a strong cation-exchange column, from which the homocysteine derivative was directed by column switching into a cyclohexyl silica (CH) column. The homocysteine derivative was top-concentrated on the CH column, then rapidly eluted with a steep gradient of methanol. Both the derivatization procedure and chromatography were performed with a combined sample processor and sample injector from Gilson (Model 232-401). Within-run and between-run precision (CV) was less than 4%, and the detection limit of 0.2 pmol was sufficiently low for monitoring homocysteine in plasma. We verified the assay against two established manual methods for the determination of total homocysteine in plasma. This, the first fully automated assay for total plasma homocysteine, allows the unattended analysis of 70 samples per 24 h.
Enzyme-linked immunosorbent assay for chromogranin A.
Authors: Dillen L , De Block J , Van Lear L , De Potter W
Published: January 2020

This is an enzyme-linked immunosorbent assay (ELISA) for determining chromogranin A (CGA) with use of a monoclonal antibody. CGA was isolated from bovine chromaffin granules. The analytical ELISA procedure for bovine CGA was developed and optimized. Typical standard curves ranged from 500 pg to 500 ng of CGA. We then studied human plasma CGA-immunoreactivity as measured by this assay. The curve for dilutions of human plasma paralleled the standard curve for bovine CGA. The intra-assay coefficient of variation for determination of human plasma CGA was 4.56%, indicating that reliable determinations can be performed for human plasma. However, further study revealed the presence of two CGA-immunoreactive substances in human plasma, one of which corresponds to the native CGA. The nature of the second immunoreactive substance still remains unknown. Nevertheless the measured CGA concentrations (ranging from 0.19 to 0.35 mg/L) in plasma are comparable with previously reported values.
Measuring creatine kinase MB isoenzyme in a maintenance hemodialysis population: chemiluminometric immunoassay and electrophoresis compared.
Authors: Latner B P , Skale J S , Burns W
Published: January 2020

In an effort to clarify the issue of potentially false increases in creatine kinase (EC 2.7.3.2) MB isoenzyme (CK-MB) in uremia, we evaluated the CK profile of 84 persons undergoing chronic maintenance hemodialysis. We compared the performance of a new commercial two-site chemiluminometric immunoassay of CK-MB (Magic Lite; Ciba Corning Diagnostics) with that of electrophoresis on agarose gel (Cardio Trak-CK; Corning Medical). Results of the new chemiluminometric immunoassay for samples from hemodialysis patients correlated well with those of the electrophoretic method (r = 0.86, P less than 0.001), showing that neither substances in the serum of uremic patients nor CK-MM isoenzyme give false-positive increases in CK-MB isoenzyme. Our evidence suggests that the chemiluminometric method may be more specific than is electrophoresis in establishing absolute CK-MB values in the diagnosis of suspected myocardial injury in this population.
Long-chain aliphatic fatty acids and phytanic acid simultaneously measured by dual-column capillary chromatography.
Authors: Tsai M Y , Cooper K
Published: January 2020

A method is described for simultaneously measuring long-chain aliphatic fatty acids and phytanic acid in plasma, for the diagnosis of disorders associated with peroxisomal defects, eliminating the need for two separate chromatographic runs to resolve all of the analytes. In addition, the simultaneous, dual-column analysis allows confirmation of the identity and quantity of the individual fatty acids, thus adding a degree of certainty when results are used for interpretation and differential diagnosis of the many clinical manifestations of peroxisomal defects.
Climbing the Rungs of the Quality Ladder: FDI and Domestic Exporters in Romania
Authors: Bajgar Matej , Javorcik Beata
Published: January 2020

This article argues that inflows of foreign direct investment can facilitate export upgrading in host countries. Using customs data merged with firm-level information for 2005–11, it shows a positive relationship between the quality of products exported by Romanian firms and the presence of multinational enterprises (MNEs) in the upstream (input-supplying) industries. Export quality is also positively related to MNE presence in the downstream (input-sourcing) industries and the same industry, but these relationships are less robust. These conclusions hold both when the product quality is proxied with unit values and when it is estimated following the approach of Khandelwal et al. (2013).
Trends in Physical and Cognitive Performance Among Community-Dwelling Older Adults in Switzerland
Authors: Henchoz Yves , Büla Christophe , von Gunten Armin , Blanco Juan Manuel , Seematter-Bagnoud Laurence , Démonet Jean-Francois , Waeber Gérard , Nanchen David , Santos-Eggimann Brigitte
Published: January 2020

Background

With population aging, a key question is whether new cohorts of older people are in better health than previous ones. This study aimed to compare the physical and cognitive performance of community-dwelling older adults assessed at similar age in 2005, 2010, and 2015.

Methods

This repeated cross-sectional analysis used data from the Lausanne cohort 65+, a three random sample population-based study. Performance of participants aged 66–71 years in 2005 (N = 1,309), 2010 (N = 1,253), and 2015 (N = 1,328) was compared using a battery of six physical and four cognitive tests. Analyses included tests for trend across samples and multivariable linear regression models.

Results

Adjusted performance in all four timed physical tests (gait speed, Timed Up-and-Go, five times chair stand, and Moberg Picking-Up) improved across samples from 2005 to 2015, by +12.7% (95% confidence interval {CI} +10.5%; +14.9%) to +20.4% (95% CI +17.7%; +23.0%) in females, and by +10.6% (95% CI +8.7%; +12.4%) to +16.7% (95% CI +13.4%; +20.0%) in males. In contrast, grip strength and balance did not improve across samples. Adjusted cognitive performance showed no change in the Trail Making Test, but worsened significantly across samples for the Mini-Mental State Examination, verbal fluency, and the clock drawing test in both females (−1.9% [95% CI −2.7%; −1.1%] to −6.7% [95% CI −8.9%; −4.6%]) and males (−2.5% [95% CI −3.4%; −1.6%] to −8.0% [95% CI −11.1%; −4.9%]).

Conclusions

Over the last decade, performance of adults aged 66–71 years improved significantly in timed physical tests but worsened in most cognitive measures among later-born samples.
Are Inflammatory Bowel Disease Patients With Diabetes Mellitus at Increased Risk for Poor Outcomes Including Greater Health Care Utilization?
Authors: Wong Uni , Cross Raymond K
Published: January 2020

Inflammatory bowel disease patients with diabetes mellitus are more likely to have active disease, report worse quality of life, and have higher health care utilization. This high-risk subgroup of patients with confirmed active disease should be treated with appropriate medical therapy including biologic therapy with or without an immunosuppressant.
Routine Testing for EBV Status in Children With Inflammatory Bowel Disease: Are We Overreacting?
Authors: El-Matary Wael
Published: January 2020

The value of testing for Epstein-Barr virus status before starting immunosuppression in children with inflammatory bowel disease remains unproven.
Antimicrobial activity of POL7306 tested against clinical isolates of Gram-negative bacteria collected worldwide
Authors: Sader Helio S , Rhomberg Paul R , Duncan Leonard R , Locher Hans H , Dale Glenn E , Flamm Robert K
Published: January 2020

Background

POL7306 belongs to a new class of peptidomimetic outer-membrane-protein-targeting antibiotics with a novel mechanism of action. POL7306 is in development for the treatment of infections caused by antimicrobial-resistant Gram-negative bacteria and has demonstrated low cytotoxicity and nephrotoxicity.

Methods

A total of 891 isolates were collected by the SENTRY Antimicrobial Surveillance Program from 134 medical centres in Europe (n = 424; 41 centres in 18 nations), the USA (n = 411 isolates from 67 centres), the Asia-Pacific region (n = 24; 15 centres in 6 nations) and Latin America (n = 32; 11 centres in 9 nations) and included 558 Enterobacterales, 310 non-fermenters and 23 fastidious organisms. Susceptibility testing was performed using the reference broth microdilution method and the medium was supplemented with 0.002% polysorbate-80 for testing POL7306. Resistant subsets were characterized by WGS.

Results

POL7306 demonstrated potent in vitro activity against Enterobacterales [including carbapenem-resistant (MIC50/90, 0.06/0.25 mg/L), ESBL-producing (MIC50/90, 0.06/0.12 mg/L), KPC-producing (MIC50/90, 0.12/0.25 mg/L), MBL-producing (MIC50/90, 0.06/0.25 mg/L), colistin-non-susceptible, mcr-negative (MIC50/90, 0.5/2 mg/L) and mcr-positive (MIC50/90, 0.12/0.25 mg/L) Enterobacterales], Pseudomonas aeruginosa (MIC50/90, 0.25/0.25 mg/L), Acinetobacter baumannii (MIC50/90, 0.06/0.12 mg/L) and Stenotrophomonas maltophilia (MIC50/90, 0.06/0.25 mg/L).

Conclusions

POL7306 demonstrated potent activity against a large collection of Gram-negative organisms collected worldwide that included colistin-resistant, XDR and ESBL- and carbapenemase-producing isolates for which there are currently limited treatment options.
Trends in antimicrobial resistance among Escherichia coli from defined infections in humans and animals
Authors: Bourély Clémence , Coeffic Thomas , Caillon Jocelyne , Thibaut Sonia , Cazeau Géraldine , Jouy Eric , Jarrige Nathalie , Chauvin Claire , Madec Jean-Yves , Haenni Marisa , Leblond Agnès , Gay Emilie
Published: January 2020

Objectives

To characterize and compare resistance trends in clinical Escherichia coli isolates from humans, food-producing animals (poultry, cattle and swine) and pets (dogs and cats).

Methods

Antibiogram results collected between January 2014 and December 2017 by MedQual [the French surveillance network for antimicrobial resistance (AMR) in bacteria isolated from the community] and RESAPATH (the French surveillance network for AMR in bacteria from diseased animals) were analysed, focusing on resistance to antibiotics of common interest to human and veterinary medicine. Resistance dynamics were investigated using generalized additive models.

Results

In total, 743 637 antibiograms from humans, 48 170 from food-producing animals and 7750 from pets were analysed. For each antibiotic investigated, the resistance proportions of isolates collected from humans were of the same order of magnitude as those from food-producing animals or pets. However, resistance trends in humans differed from those observed in pets and food-producing animals over the period studied. For example, resistance to third-generation cephalosporins and fluoroquinolones was almost always below 10% for both humans and animals. However, in contrast to the notable decreases in resistance observed in both food-producing animals and pets, resistance in humans decreased only slightly.

Conclusions

Despite several potential biases in the data, the resistance trends remain meaningful. The strength of the parallel is based on similar data collection in humans and animals and on a similar statistical methodology. Resistance dynamics seemed specific to each species, reflecting different antibiotic-use practices. These results advocate applying the efforts already being made to reduce antibiotic use to all sectors and all species, both in human and veterinary medicine.
The Impact of Yoga on Fatigue in Cancer Survivorship: A Meta-Analysis
Authors: Armer Jessica S , Lutgendorf Susan K
Published: January 2020

Background

Mind-body approaches, particularly yoga, are used by cancer survivors to cope with treatment-related symptoms. Consistency of yoga-related effects on treatment-related symptoms are not known. This meta-analysis was designed to examine effects of yoga on pre- to postintervention improvements in fatigue among cancer patients.

Methods

PubMed and PsycINFO were searched for peer-reviewed articles of yoga randomized controlled trials including cancer survivors and reporting at least one fatigue measure. Twenty-nine studies met inclusion criteria (n = 1828 patients). Effect sizes (Hedge’s g) were calculated for fatigue, depression, and quality of life. Patient-related and intervention-related characteristics were tested as moderators of outcomes. All statistical tests were two-sided.

Results

Yoga practice was associated with a small, statistically significant decrease in fatigue (g = 0.45, P = .013). Yoga type was a statistically significant moderator of this relationship (P = .02). Yoga was associated with a moderate decrease in depression (g = 0.72, P = .007) but was not associated with statistically significant changes in quality of life (P = .48). Session length was a statistically significant moderator of the relationship between yoga and depression (P = .004). Neither timing of treatment (during treatment vs posttreatment) nor clinical characteristics were statistically significant moderators of the effects of yoga on outcomes. The effect of yoga on fatigue and depression was larger when the comparator was a “waitlist” or “usual care” than when the control group was another active treatment (P = .036).

Conclusions

Results suggest yoga may be beneficial as a component of treatment for both fatigue and depression in cancer survivors.
Follow-up and Clinical Outcomes of Human Immunodeficiency Virus (HIV)–Exposed Infants in A Low-Prevalence Setting in A Multidisciplinary Model of Care in Australia: The Children’s HIV Exposure Study 1
Authors: Shepherd Kathryn , Giles Michelle , Blyth Karen , O’Keeffe Fiona , Bordun Louise , Connell Tom G , Bryant Penelope A
Published: January 2020

Background

Prevention of mother-to-child transmission (PMTCT) of human immunodeficiency virus (HIV) is effective, but outcome information beyond the postnatal period in low-prevalence settings is scarce. A multidisciplinary model of care (MOC) was developed to ensure PMTCT. Our aims in this study were to assess how well HIV-exposed infants are followed up through this MOC and to determine infant outcomes to age 18 months.

Methods

This was a multicenter, prospective study of infants exposed to HIV during pregnancy, born 1 September 2009–31 August 2016 in Victoria, Australia.

Results

There were 129 live births from 127 pregnancies. There were no episodes of HIV transmission. Sixteen (13%) infants were born prematurely, 15 (12%) had low birthweight, and 6 (5%) had a congenital anomaly. There were 122 (95%) infants with an HIV polymerase chain reaction (PCR) within 2 weeks of birth. The proportion in the MOC reduced from 95% at 2 weeks postnatally to 75% by 18 months. Eighty-eight percent cared for within the MOC had 2 viral PCR tests completed after stopping antiretroviral prophylaxis compared with 22% of those outside of the MOC. By 18 months, 84/126 (67%) children attended follow-up, with higher rates within the MOC than outside (76% vs 6%; odds ratio, 46; 95% confidence interval, 6 to 365; P < .001).

Conclusions

HIV-exposed, uninfected infants in this low-prevalence setting had good prospective follow-up through this MOC to 3 months. The decrease in follow-up by 18 months could be addressed in several ways, including expanding the MOC and providing better links to regional/rural services.