bluuebunny/crossref_metadata_2025_split huggingface dataset:
Excretion of digoxin-like immunoreactivity in urine of normal subjects: correlations with excretion of creatinine and electrolytes.
Authors: Clerico A , Giampietro O , Gregori G , Del Chicca M G , Bertoli S , Miccoli R , Navalesi R 
Published: January 2020

Abstract
To verify whether there is a variation in the 24-h urinary excretion of digoxin-like immunoreactivity (DLIS) in humans, we studied 18 normal adults, who collected their urines for 24-h in several portions. We then measured DLIS (by means of a sensitive RIA method), creatinine, sodium, and potassium concentrations in the urine samples. The mean urinary excretion rate for DLIS in the complete 24-h collection was 84.8 (SD 31.3) pg/min. The mean DLIS urinary excretion rate calculated for overnight collections was significantly lower than those of afternoon collections (P less than 0.01) and the 24-h collection (P less than 0.05). Significant positive correlations were found between urinary DLIS and excretion rates for creatinine (r = 0.347, P = 0.0016), Na+ (r = 0.232, P = 0.038), and K+ (r = 0.323, P = 0.003), respectively. Our data suggest that urinary excretion of DLIS is higher during "active" hours of the day, especially in the afternoon, than at rest, during the night.
Melanogenuria: laboratory evaluation of the qualitative Thormählen and ferric chloride tests and their clinical utility.
Authors: Scott R E , Ward V L , Grinstead G F , Stevens B S , Wilson D M 
Published: January 2020

Abstract
Malignant melanoma, a disease that is increasing in occurrence and medical concern, is characterized by the excretion of melanogens. Two qualitative tests are recommended for melanogen detection, the Thormählen test and the ferric chloride test. We evaluated the laboratory and clinical performance of these tests by subsequently re-evaluating 201 urine samples that had been submitted for routine melanogen analysis. We used (a) Thormählen, (b) ferric chloride, (c) small-scale thin-layer chromatography, and (d) spectrophotometry. Nearly 30% of Thormählen test results were equivocal. The ferric chloride test was of no value in itself or in categorizing equivocal Thormählen results as positive or negative. The small-scale chromatography was irreproducible. Prompt scanning of the Thormählen reaction product was helpful in classifying equivocal results. History review of 121 histopathologically diagnosed melanoma patients indicated that these qualitative assays were of no clinical value in the diagnosis or monitoring of melanoma patients.
Intra-individual variation of thyroxin, triiodothyronine, and thyrotropin in treated hypothyroid patients: implications for monitoring replacement therapy.
Authors: Browning M C , Bennet W M , Kirkaldy A J , Jung R T 
Published: January 2020

Abstract
We measured total thyroxin (TT4), free thyroxin (FT4), total triiodothyronine (TT3), free triiodothyronine (FT3), and thyrotropin (TSH) in serum sampled before and 1, 2, 4, 6, and 8 h after administration of prescribed doses of thyroxin to 12 patients with proven primary hypothyroidism. At 2, 4, and 6 h post-dose, the mean values for TT4 and FT4 and also that at 8 h for FT4 significantly (P less than 0.05) exceeded the corresponding pre-dose values. No significant changes were found for TT3, FT3, or TSH. The mean intra-individual CVs over the study period were TT4 4.9%, FT4 5.7%, TT3 8.7%, FT3 8.7%, and TSH 20.2%. Individual subjects showed small but predictable changes in TT4 and FT4. Changes in TT3 and FT3 were greater but random. Fluctuations in TSH were greatest, but in all subjects with detectable concentrations the variations were of similar magnitude. We conclude that strict adherence to timing of specimen collection in relation to dosage is probably unnecessary.
The changing epidemiology of depression.
Authors: Klerman G L , Weissman M M 
Published: January 2020

Abstract
At the clinical level, we have seen the emergence of a subspecialty of affective disorders within psychiatry. Mood clinics, depression units, and affective disorders centers are appearing in many academic and clinical settings, where clinical skill and knowledge can be concentrated and new research furthered. By using structured interviews and the newer diagnostic systems, systematic evaluation of patients has contributed to improved care. Greater skill in psychopharmacology and in specialized psychotherapeutic techniques has resulted in reduction of hospitalization and rates for depression, shortened duration of illness, and, in some instances, reports of reduction in suicide attempts and suicide deaths.
Reliability of antidepressant assays: a reference laboratory perspective on antidepressant monitoring.
Authors: Labrosse K R , McCoy H G 
Published: January 2020

Abstract
Chromatography (gas and liquid) and immunoassays are used for monitoring the commonly prescribed tricyclic antidepressants. Many commercially available immunoassays are known to cross react with structurally similar compounds. Chromatographic methods make it possible simultaneously to resolve and quantify amitriptyline, nortriptyline, imipramine, desipramine, trimipramine, doxepin, desmethyldoxepin, protriptyline, and maprotiline-and potentially crossreactive compounds can be separated from the tricyclics. Immunoassays may have a valuable role in initial toxicological screening for the presence of a tricyclic-like compound, and they also may be helpful in a laboratory dedicated to a well-controlled patient group. However, 10% of our specimens contain more or different antidepressants than we are requested to analyze for. With our analysis, we are able to report which antidepressants are present, and in what concentrations. Further, in the case of a potential overdose of tricyclic, the primary purpose for early toxicological analysis to anticipate subsequent clinical complications. Therefore, even in the case of toxicological analysis, it is important to know exactly what tricyclic antidepressant is present rather than just the semiquantitative presence of one or more structurally related compounds, because these various compounds differ markedly in their potential for adverse effects. There are too many potential, and possibly yet unknown, interactions for a reference laboratory routinely to rely on immunoassays for therapeutic drug monitoring or toxicological identification of antidepressants.
Pharmacokinetic factors affecting antidepressant drug clearance and clinical effect: evaluation of doxepin and imipramine--new data and review.
Authors: Ereshefsky L , Tran-Johnson T , Davis C M , LeRoy A 
Published: January 2020

Abstract
The selection of a starting dose for an antidepressant, and subsequent clinical titration to an appropriate therapeutic dosage, should be based on pharmacokinetic and pharmacodynamic principles. In the past decade, therapeutic monitoring of antidepressant drugs and use of pharmacokinetic principles have been shown to be an improvement over the dose-response approach. Endogenous (e.g., genetic metabolic phenotype, hepatic blood flow, and protein binding) and exogenous factors (e.g., smoking, dietary habits, concurrent medications) are capable of influencing physiological and pharmacokinetic variables in patients, accounting for the marked interindividual differences in the clearance rates of cyclic antidepressants. Interpatient variability for steady-state concentrations in plasma (Cpss) greater than 20-fold are observed at a fixed dose of imipramine (r2 = 0.525, df = 346, t = 19.541, P less than 0.0001) or doxepin (r2 = 0.506, df = 128, t = 11.403, P less than 0.0001). Analysis of doxepin in plasma vs estimated in oral clearance for 61 patients demonstrates a significant decline in oral clearance as a function of Cpss. At doses approaching the upper range recommended for the treatment of depression, Cpss appear to approach, in at least a few individuals, the maximum metabolic capacity of the patient (Vmax), leading to greater-than-expected increases in concentrations for a given dosage increment. Significant alterations in oral clearance are observed when medications are administered concomitantly. A greater-than-threefold difference in mean oral doxepin clearance rates is observed between two groups of patients receiving additional medications that are either inducers or inhibitors (P less than 0.0001, df = 32, t = 6.687). Pharmacokinetic principles defining and explaining the determinants of oral clearance can provide the clinician with a greater insight into the reasons for therapeutic failure and toxicity.
Quantification of hemoglobins S, C, and F by a magnetic affinity immunoassay.
Authors: Moscoso H , Kiefer C R , Kutlar A , Garver F A 
Published: January 2020

Abstract
This magnetic affinity immunoassay (MAIA) quantifies hemoglobins (Hb) S, C, and F in hemolysates from adults or newborns. Monospecific antisera to the hemoglobins are covalently conjugated to magnetic beads and reacted with the corresponding 125I-labeled hemoglobin. After centrifugation to separate the free and antibody-bound 125I-labeled hemoglobin, the amount of radioactive hemoglobin in the pellet is measured. To determine the concentration of the Hb under study, the percent inhibition of the reaction is quantified. The standard curve is established by adding known quantities of unlabeled hemoglobin before adding 125I-labeled hemoglobin. The amount of Hb S, Hb C, or Hb F present in hemolysates is determined by measuring the percentage of inhibition and extrapolating the concentration from the standard curve. Results agree well with values for Hb S and Hb C obtained by "high-performance" liquid chromatography and RIA and for Hb F as measured by alkali denaturation and RIA. This assay can be completed in 1 h and is more sensitive than enzyme immunoassay or RIA: we can detect proportions of Hb S and Hb C as low as 1% of total Hb, and Hb F as low as 0.05%.
Incidence and source of hyperamylasemia after cardiac surgery.
Authors: Kazmierczak S C , Van Lente F 
Published: January 2020

Abstract
We investigated the incidence and possible mechanisms of postoperative hyperamylasemia in 101 patients after cardiac surgery. Amylase (EC 3.2.1.1) activities in serum were increased in 36% of patients after bypass surgery, 59% of patients after valve replacement, and in 69% of patients after combined bypass and valve replacement. Lipase (EC 3.1.1.3) activity was increased in 30% of all patients. We found enzymatic evidence for pancreatitis in six patients. Thirty-six patients showed increased salivary (S-type) amylase activity, with a positive correlation (r = 0.55, P less than 0.001) between the severity of pleural effusions and the peak S-type amylase activity. Hyperamylasemia after cardiac surgery is apparently often related to absorption of S-type amylase from pleural fluid and (or) from aspirated salivary secretions. Monitoring patients for postsurgical pancreatitis necessitates assay of amylase isoenzymes to distinguish abnormalities resulting in release of pancreatic (P-type) amylase from those involving release of S-type amylase.
Solid-phase radioimmunoassay of human complement fragment C5a.
Authors: Chang S , Leo-Mensah A , Campbell J , Stastny M , Patrick R A 
Published: January 2020

Abstract
In this competitive RIA for determining concentrations of human C5a in biological fluids and in buffers, labeled C5a and sample are allowed to compete for binding to a limited amount of goat antibody to human C5a in solution. Free and bound tracer are then separated by a second antibody (rabbit anti-goat IgG) immobilized on paramagnetic particles. Total incubation time for this assay is 70 min. Sensitivity, precision, and analytical recovery of this assay compare well with those of a reference method.
Heterogeneity of lipoprotein Lp(a) and apolipoprotein(a).
Authors: Grinstead G F , Ellefson R D 
Published: January 2020

Abstract
We have purified Lp(a) lipoproteins from sera of four subjects by ultracentrifugation, selective precipitation, and chromatofocusing. Each subject had two forms of serum Lp(a) that were separable by chromatofocusing. We purified apolipoprotein (a) [apo(a)] from the eight isolated Lp(a)s and obtained only one form of apo(a) from each subject. The four apo(a)s seen on sodium dodecyl sulfate-polyacrylamide gel electrophoresis had different apparent molecular masses, ranging from 275 to 440 kDa. Chemical deglycosylation of the smallest apo(a) yielded a 235 kDa protein, which may be a core protein structure common to all apo(a)s. We conclude that there are many forms of serum Lp(a) and apo(a). The heterogeneity of serum Lp(a) particles can be ascribed in part to differences in size of apo(a), but other factors must account for the existence within a single patient of different Lp(a)s that contain apparently identical apo(a). One must consider the heterogeneity of Lp(a) when designing assays for this lipoprotein.
Ratios for very-long-chain fatty acids in plasma of subjects with peroxisomal disorders, as determined by HPLC and validated by gas chromatography-mass spectrometry.
Authors: Hall N A , Lynes G W , Hjelm N M 
Published: January 2020

Abstract
We describe an HPLC method for measurement of ratios of concentrations of very-long-chain fatty acids (VLCFA) in plasma. The method, which involves ultraviolet detection of p-bromophenacyl derivatives of fatty acids, is validated by comparison with a gas chromatographic-mass spectrometric (GC-MS) method. The correlation between the ratios of 24-carbon fatty acids to 22-carbon fatty acids (C24/C22) estimated by the two methods was close (r = 0.976) as was the correlation for the C26/C22 ratios (r = 0.947). Increased VLCFA ratios could be demonstrated by either technique in patients with adrenoleukodystrophy, Zellweger syndrome, and infantile Refsum's disease. The HPLC method also measures phytanate concentrations in plasma. Control VLCFA ratios (for subjects without peroxisomal disorders) obtained by the two methods agree well with those reported by Moser et al. (Ann Neurol 1984; 16:628-41). For subjects younger than one year, ratios for C24/C22 and C26/C22 fatty acids were significantly greater than in older subjects.
Creatine kinase MM isoforms in serum after cardiac surgery.
Authors: Keshgegian A A , Bhagat P K , Lease J A , Balocchi J 
Published: January 2020

Abstract
We evaluated creatine kinase (CK; EC 2.7.3.2) MM3:MM1 isoform ratios in the serum of cardiac patients immediately after cardiac surgery for the diagnosis of perioperative myocardial injury. The mean ratio was 4.8 (range, 1.4-10.7) in 22 patients who had postoperative myocardial complications and 4.6 (1.3-9.6) in 66 patients who did not. By the first postoperative day the ratio had decreased substantially in both groups of patients. The isoform ratio did not correlate with the concentration of total CK, CK-MB, total lactate dehydrogenase (LD), or the incidence of LD1:LD2 or LD5:LD2 ratio reversal. Of these measurements, CK-MB and LD concentrations differed most between the groups of patients; parallel testing of CK-MB and LD showed an optimized sensitivity and specificity of 77% and 87%, respectively. We conclude that analysis for CK-MM isoforms does not add information in the period immediately after cardiac surgery; concentrations of CK-MB and LD correlate with myocardial injury, but the sensitivity and specificity of these measurements may not be high enough for clinical utility.
Confirmation of a false-positive result in CA 125 immunoradiometric assay caused by human anti-idiotypic immunoglobulin.
Authors: Klug T L , Green P J , Zurawski V R , Davis H M 
Published: January 2020

Abstract
An immunoradiometric assay (IRMA) involving a monoclonal antibody (MAb OC125) to an ovarian carcinoma-associated antigenic determinant (CA 125) has been tested as one component in a strategy for early detection of epithelial ovarian cancer. We characterized one confirmed "false-positive" sample by murine antibody blocking studies, Western blotting, immunoaffinity, size-exclusion chromatography, and reactivity with polyclonal rabbit antisera to CA 125 antigen. The positive response of this serum in the CA 125 IRMA was due to a human IgM. The discrepant IgM was isolated from the serum by successive immunoaffinity steps with nonspecific murine MAb, MAb OC125, and goat antibodies to human IgM Fc. Purified IgM inhibited the binding of MAb OC125 to CA 125. Furthermore, rabbit antisera to CA 125 antigen competitively inhibited the binding of MAb OC125 to both CA 125 and the discrepant IgM. The discrepant activity thus appears to reflect binding of this human IgM to a idiotope of MAb OC125. Radioiodination of MAb OC125 by a different technique eliminated the discrepant activity and decreased the incidence of CA 125 positivity in an at-risk population of apparently healthy women, increasing the specificity of the IRMA to 99.8% in this group.
Solid-phase extraction with strong anion-exchange columns for selective isolation and concentration of urinary organic acids.
Authors: Verhaeghe B J , Lefevere M F , De Leenheer A P 
Published: January 2020

Abstract
This is a new method for isolating and concentrating urinary organic acids before gas chromatography--mass spectrometry. Sulfate and phosphate anions are removed by precipitation with Ba(OH)2, and the urine pH is adjusted to 8-8.5. The sample is then applied onto small, disposable, strong-anion-exchange columns. Neutral and basic compounds are washed out with water, which is then removed by centrifugation and by rinsing the columns with methanol and diethyl ether. The organic acids are eluted with a 4/1 (by vol) mixture of an organic solvent--either n-butanol or ethyl acetate--and formic acid containing HSO4- (0.1 mol/L) as a highly selective counter-ion, and finally with methanol alone. Sulfate ions are retained, and the eluate is evaporated before trimethylsilyl derivatization. Analytical recoveries (about 100%) of organic acids compare favorably with those obtained with solvent extraction. This convenient procedure is selective and reproducible and is a suitable alternative to the more cumbersome diethylaminoethyl-Sephadex extraction method.
Effect of glucose loading on concentrations of chromium in plasma and urine of healthy adults.
Authors: Morris B W , Griffiths H , Kemp G J 
Published: January 2020

Abstract
We report here a small study designed to identify the effect of a 75-g oral glucose load on concentrations of chromium in plasma and urine of apparently healthy volunteers. We detected a consistent and significant (P less than 0.01) decline in plasma chromium after glucose administration, the nadir of the chromium response coinciding with the zenith of the glucose concentration.
An analysis for blood manganese used to assess environmental exposure.
Authors: Hams G A , Fabri J K 
Published: January 2020

Abstract
In this graphite-furnace atomic-absorption spectrometric method for measuring manganese in whole blood, we use a pyrolytic platform to minimize interference by sample matrix. For optimal sample ashing we denature the sample within the furnace with nitric acid and use oxygen as the purge gas at low temperatures. The mean manganese concentration found in blood from 15 unexposed city dwellers was 215 (2 SD 135) nmol/L. By comparison, the range of manganese concentrations in blood sampled from a group of Australian aborigines living near a surface manganese ore deposit on Groote Eylandt, Northern Territory, was much higher (median 405 nmol/L, range 175 to 990 nmol/L).
Anion transport as related to hemoglobin A1c in erythrocytes of diabetic children.
Authors: Brahm J , Mortensen H B 
Published: January 2020

Abstract
We determined chloride and bicarbonate transport [Jcl and Jbic, nmol/(cm2.s)] under physiological conditions (Cl- 110 and HCO3- 25 mmol per liter, respectively, pH 7.4, 38 degrees C) across the erythrocyte membrane in blood samples from 12 diabetic (Jcl 26.1, SD +/- 3.7, n = 24; Jbic 7.6, SD +/- 0.9, n = 19) and 10 non-diabetic children (Jcl 30.6, SD +/- 4.6, n = 16; Jbic 7.3, SD +/- 1.0, n = 20) with mean hemoglobin A1c values of 11.08% (SD +/- 2.45%) and 5.36% (SD +/- 0.25%), respectively. The concentration of HbA1c, which also reflects the degree of glycation of the membrane proteins, differed significantly (P greater than 0.001) between the two groups, whereas there was no significant variation (P greater than 0.1) in Jcl and Jbic. We conclude that glycation of the integral transport protein in the erythrocyte membrane, capnophorin (also called "band 3"), which mediates a tightly coupled anion exchange, does not change the capacity of the transport system under physiological conditions. Thus the rate-limiting step of the exploitation of the CO2 transport capacity of the blood is not impaired in diabetics and consequently does not endanger the compensatory hyperventilation after ketoacidosis.
Fiber optic immunochemical sensor for continuous, reversible measurement of phenytoin.
Authors: Anderson F P , Miller W G 
Published: January 2020

Abstract
This fiber optic sensor, based on a homogeneous fluorescence energy-transfer immunoassay, operates in a continuous, reversible manner to quantify the anticonvulsant drug phenytoin. B-Phycoerythrin-phenytoin and Texas Red-labeled antibody to phenytoin were sealed inside a short length of cellulose dialysis tubing, which was cemented to the distal end of an optical fiber. When the sensor was alternately placed into solutions with various concentrations of free phenytoin, the drug crossed the dialysis membrane and displaced a fraction of the B-phycoerythrin-phenytoin from the antibody. The resulting change in fluorescence signal was measured with a fiber optic fluorometer. A typical competitive-binding calibration curve was seen between 5 and 500 mumol of phenytoin per liter. Equilibrium response time ranged from 5 to 30 min for different sensors. Replicate equilibrium measurements with one sensor, alternated eight times between two solutions of phenytoin, gave a CV of 2.1% (n = 16) at 0 mumol/L and 2.4% (n = 13) at 100 mumol/L. A reversible immunochemical sensor can be made that has a response time suitable for continuous concentration measurements.
In vivo 31P nuclear magnetic resonance spectroscopy of bone mineral for evaluation of osteoporosis.
Authors: Brown C E , Battocletti J H , Srinivasan R , Allaway J R , Moore J , Sigmann P 
Published: January 2020

Abstract
The mineral content of stationary bone samples can be quantified by 31P nuclear magnetic resonance (NMR) spectroscopy. The assay can be performed in regions of the anatomy that pose problems for absorptiometric techniques, because the mineral content is measured within a selected volume without concern for the geometry of the bone. In vivo 31P NMR spectra of the bones in human fingers and wrist are reported. Soft tissue such as marrow and skeletal muscle contributes little to the 31P NMR spectra of human fingers and wrist and thus should not seriously affect the accuracy of the mineral assay. 31P NMR spectrometry should prove helpful for confirming rapid bone mineral loss in those at risk and for monitoring response to treatment.