bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of residual liquid junction potential in direct potentiometry of potassium.
Authors: Winkelman J W , Merritt C , Scott W J , Kumar A , Baum G
Published: January 2020

To further the accurate direct potentiometry of plasma electrolyte concentrations, we investigated the effects of solution composition on the residual liquid junction potential (RLJP) during measurement of K+. Assuming that the binding constant between K+ and proteins or bicarbonate is no greater than with Na+, we calculate that the amount of bound K+ can be neglected. A significant RLJP exists between simple solutions containing Na+, K+, and Cl- ions and solutions containing Na+, K+, Cl-, and HCO3- ions. Replacing Cl- with HCO3- leads to an increase in the RLJP, which in turn contributes to a negative error in K+ analysis. A small decrease in RLJP is observed as the ionic strength is increased. The Henderson equation gives a reasonable estimate of the magnitude of the observed RLJP, even though the liquid junction does not meet the conditions under which the equation is rigorously applicable. Errors attributed to RLJP may be substantially minimized by using a calibrator solution that contains an anion with mobility similar to that of HCO3-.
Urea, creatinine, and glucose determined in plasma and whole blood by a differential pH technique.
Authors: Ripamonti M , Mosca A , Rovida E , Luzzana M , Luzi L , Ceriotti F , Cottini F , Rossi-Bernardi L
Published: January 2020

We report the conditions (buffer composition and enzyme activity) required for estimating three frequently determined analytes--urea, glucose, and creatinine--by use of an improved version of the differential pH apparatus previously described (Clin Chem 29: 80-85, 1983). For each analyte, we used only one specific enzyme, thus avoiding a chain of auxiliary and indicator reactions. The method requires about a minute for each determination in undiluted plasma or whole blood.
Values for some serum analytes in high-risk infants, two days postpartum.
Authors: Fitzsimons E J , Fletcher M A , Chakrin A
Published: January 2020

Using a continuous-flow (Technicon SMAC) analyzer, we measured the concentration of 20 analytes in capillary blood sera from 149 neonates in an intensive-care unit. Included were term and pre-term babies, both groups with and without asphyxia. The values obtained, especially for those enzymes and analytes that are related to renal function, offer baseline data against which the effect of therapeutic and physiological changes can be evaluated.
Complexes of serum gamma-glutamyltransferase with apolipoproteins and immunoglobulin A.
Authors: Artur Y , Wellman-Bednawska M , Jacquier A , Siest G
Published: January 2020

We have detected complexes between gamma-glutamyltransferase and apolipoproteins or immunoglobulin A in sera from patients with hepatobiliary diseases but not in sera from healthy individuals. An average of 52.4% of the enzymic activity was precipitated by antiserum against apolipoprotein A, 29.9% by antiserum against apolipoprotein B, and 9.7% by antiserum against immunoglobulin A. Fifty to 60% of the enzyme activity was inhibited in the immunoprecipitates from the transferase fraction bound to apolipoprotein A or immunoglobulin A, and 21% in the fraction bound to apolipoprotein B. We identified the complexed transferase fractions by electrophoresis.
Homogeneous luminescence immunoassay for total estrogens in urine.
Authors: Messeri G , Caldini A L , Bolelli G F , Pazzagli M , Tommasi A , Vannucchi P L , Serio M
Published: January 2020

We describe an homogeneous luminescence immunoassay for "total" estrogens in enzymically hydrolyzed urine from nonpregnant women. The antiserum, raised against estriol-16,17- dihemisuccinate conjugated to bovine serum albumin, specifically bound the C-19 steroids carrying the estrogen-characteristic phenolic group. 17 beta-Estradiol conjugated with aminobutylethyl isoluminol was used to monitor the immunological reaction; this conjugate was stable for at least two years. Because binding to the antiserum markedly enhances the light-producing efficiency of the tracer, no separation of bound and free antigen is necessary. Results (microgram/24 h) by this method (y) correlated well (r = 0.958) with those by a conventional fluorometric (x) method (y = 2. 51x - 2.83). The sensitivity (detection limit) is 4 micrograms/L and the precision compares well with that of commonly used RIA methods. The method appears suited to large numbers of samples, as in menstrual cycle monitoring.
Improved determination of transketolase activity in erythrocytes.
Authors: Takeuchi T , Nishino K , Itokawa Y
Published: January 2020

We describe a new and better method for determining transketolase (EC 2.2.1.1) activity in human erythrocytes. Heating the hemolysate (55 degrees C, 5 min) inactivates transaldolase (EC 2.2.1.2), the enzyme that catalyzes the formation of fructose 6-phosphate and erythrose 4-phosphate from sedoheptulose 7-phosphate and glyceraldehyde 3-phosphate. The net effect is that the quantity of sedoheptulose 7-phosphate formed more precisely represents the transketolase activity, which is unaffected under these conditions. Use of ribosephosphate isomerase (EC 5.3.1.6) and ribulose-phosphate 3-epimerase (EC 5.1.3.1) to establish an equilibrium among the pentoses allowed us to confirm the stoichiometry of the transketolase reaction. We also discuss the effect of thiamin pyrophosphate, which is used to reflect thiamin deficiency.
Are reference limits for serum creatine kinase valid in detection of the carrier state for Duchenne muscular dystrophy?
Authors: Gruemer H D , Miller W G , Chinchilli V M , Leshner R T , Hassler C R , Blasco P A , Nance W E , Goldsmith B M
Published: January 2020

We evaluated serum creatine kinase (CK) as an index to heterozygosity in Duchenne muscular dystrophy. When the 97.5th percentile of the CK normal reference interval was selected as the cutoff point, only 31% of 28 obligate carrier mothers and 24% of 43 mothers of simplex cases (those with only one occurrence of dystrophy in the kindred) exceeded this cutoff value. The outcome depended to some degree on the method used for establishing the reference limit for 379 presumably non-carrier, ambulatory women. The considerable overlap of CK activities between the control and carrier population as well as the non-gaussian distribution of the data permitted no satisfactory approach for differentiating these two populations. Neither the application of likelihood ratios, which evaluates a continuum of results without the dichotomy of a cutoff point, nor the application of predictive value based on sensitivity and specificity, which involves use of a cutoff value for decision making, provided a reliable estimate of carrier status. There was no significant difference (2 alpha = .19) between the median CK activity of obligate carrier mothers and mothers of simplex cases. The serum CK test does not provide data that either support or reject the Haldane hypothesis.
Silver staining of unconcentrated cerebrospinal fluid in agarose gel (Panagel) electrophoresis.
Authors: Mehta P D , Mehta S P , Patrick B A
Published: January 2020

We subjected cerebrospinal fluid (CSF) from 20 patients with multiple sclerosis and 20 patients with other neurological diseases to agarose gel ( Panagel ) electrophoresis followed by staining with silver. Ten microliters of unconcentrated CSF from multiple sclerosis patients containing 0.4 to 0.8 microgram of immunoglobulin G was found to be optimum for detection of oligoclonal IgG bands, so identified by immunofixation. The band patterns for unconcentrated CSF stained with silver were almost identical to those for the same CSF concentrated 40-fold and stained with Coomassie Brilliant Blue. Silver staining thus enables the clinical laboratory to electrophorese unconcentrated CSF on commercially prepared ( Panagel ) plates.
Improved assay of unconjugated estriol in maternal serum or plasma by adsorption and liquid chromatography with fluorimetric detection.
Authors: Andreolini F , Borra C , Di Corcia A , Laganà A , Samperi R , Raponi G
Published: January 2020

In this improved assay only a 500-microL sample is needed and a single assay can be done within 30 min, 10 samples within 90 minutes. The sample of serum or plasma is diluted 20-fold with water, and the estriol is adsorbed from it onto graphitized carbon black ( Carbopack B, Supelco ). After two washings the estriol is desorbed with chloroform/methanol (60/40 by vol), which then is evaporated. The residue is redissolved in 50 microL of water/acetonitrile, and 20 microL is injected into the chromatograph. Analytical recovery for estriol-supplemented serum or plasma averaged 98.6%. Day-to-day CVs ranged from 3.9% at 2 micrograms/L to 2.1% at 20 micrograms/L. The limit of sensitivity is 0.3 micrograms/L, which makes this procedure suitable for determination of estriol even in the first half of pregnancy. Our method is inexpensive, and shows that liquid chromatography can be used to determine estriol in pregnancy serum or plasma. It also is more sensitive and precise and requires less sample than other such methods.
Electrothermal atomic absorption determination of aluminum in tissues dissolved in tetramethyl ammonium hydroxide.
Authors: Stevens B J
Published: January 2020

In this rapid, precise method for the accurate determination of aluminum in biological tissue, the only preparative step required is the dissolution of the sample in hot aqueous tetramethyl ammonium hydroxide, followed by dilution with ethanol. Aluminum is measured by electrothermal (graphite furnace) atomic absorption spectroscopy, with direct reference to aqueous standards. The CVs for the method within-day and day-to-day are 3.0% and 6.8%, respectively. Analytical recovery of added aluminum is 86 to 108%, and matrix effects are minimal. Measurement of aluminum in tissue from normal laboratory rats and rats injected with aluminum gave values close to those found by an acid digestion method, but higher than those obtained by extraction with a saturated solution of ethylenediaminetetraacetate.
Discrepancies between serum free triiodothyronine and free thyroxin as measured by equilibrium dialysis and analog radioimmunoassay in nonthyroidal illnesses.
Authors: Liewendahl K , Tikanoja S , Helenius T , Välimäki M
Published: January 2020

We determined free triiodothyronine (FT3) and free thyroxin (FT4) in serum of patients with various nonthyroidal illnesses (NTI), by both commercial analog-type radioimmunoassays (A) and new equilibrium dialysis procedures (D). The mean FT3 was significantly lower in NTI by both techniques, but the decreases were of different magnitudes. The FT3(D):FT3(A) ratio was 1.96, vs 1.11 for healthy controls. In NTI the mean FT4(D) was somewhat increased, whereas the mean FT4(A) was much lower than normal, the above ratio being 1.70, vs 0.92 for controls. We ascribe these discrepancies, at least in part, to binding of radiolabeled T3- and T4-analog tracers to serum albumin.
Ultrastructural localization of aluminum in patients with dialysis-associated osteomalacia.
Authors: Verbueken A H , Van de Vyver F L , Van Grieken R E , Paulus G J , Visser W J , D'Haese P , De Broe M E
Published: January 2020

Using laser microprobe mass analysis, we studied the ultrastructural localization of aluminum in liver and bone tissue of chronic-hemodialysis patients with proven aluminum-induced osteomalacia. In the liver, aluminum was observed to be almost exclusively associated with iron. Detectable aluminum and large amounts of iron were found in lysosomes of both hepatocytes and Kupffer cells. In bone, aluminum was localized at the osteoid/calcified-bone interface and also was associated with iron in some cases.
Electrophoretic variants of alanine aminopeptidase, alkaline phosphatase, and gamma-glutamyltransferase in urine.
Authors: Jung K , Wischke U W
Published: January 2020

The three brush-border enzymes--alanine aminopeptidase (EC 3.4.11.2), alkaline phosphatase (EC 3.1.3.1), and gamma-glutamyltransferase (EC 2.3.2.2)--are present in the urine of healthy persons in two variants, a particulate form and a soluble one. They can be separated by electrophoresis in agarose gel and by ultracentrifugation. The particulate forms exhibit similar electrophoretic mobility, but the soluble forms of these brush-border enzymes differ in their electrophoretic mobilities. The enzyme components of the particulate activity can be mobilized by Triton X-100 and trypsin. The electrophoretic mobility of the soluble forms of alanine aminopeptidase and gamma-glutamyltransferase is slowed by neuraminidase treatment. Both forms of gamma-glutamyltransferase are influenced in their electrophoretic mobility by treatment with n-butanol/diisopropyl ether, showing their lipid dependence. These findings enhance our knowledge of the biochemical nature of brush-border enzymes in urine.
Direct potentiometric determination of sodium ion in blood. II. Influence of cations.
Authors: Bijster P , Vink K L
Published: January 2020

We measured the emf of NaCl solutions (120-160 mmol/L), with and without the addition of KCl (5-20 mmol/L), CaCl2 (2-8 mmol/L), or MgCl2 (1-4 mmol/L). Measurements were made with a home-built cell in steady-state and with two commercial direct potentiometric analyzers about 20 s after the sample was introduced. We calculated the sodium ion activity in the mixed NaCl-KCl solutions according to different thermodynamic theories and found almost the same results. We conclude that the influence on the emf of physiological concentrations of these cations was negligible when emf measurements were made in steady-state with the home-built cell. Of the three added cations, K+ caused the greatest increase in apparent sodium ion activity (up to about 4%) when emf measurements were made with commercial analyzers, owing to low salt-bridge concentration and the short measuring time of about 20 s.
Two-site monoclonal antibody assays for human heart- and brain-type creatine kinase.
Authors: Jackson A P , Siddle K , Thompson R J
Published: January 2020

Monoclonal antibodies have been raised against human heart- and brain-type creatine kinase (CK-MB and CK-BB). We used a low-affinity monoclonal antibody to develop a simple two-step immunoaffinity purification procedure for native CK-MB. Antibodies of higher affinity were used to construct specific two-site immunoradiometric assays for CK-MB and CK-BB. In the assay for CK-MB we used an 125I-labeled B subunit-specific antibody with an immobilized anti-M subunit antibody--adding either simultaneously, for a 1-h assay in which between 5 and 1000 ng of CK-MB per milliliter could be measured with an intra-assay CV of 4% to 20%, or sequentially, for a 2-h magnetic separation assay in which between 0.5 and 1000 ng/mL could be measured with an intra-assay CV of 14 to 19%. In both versions CK-BB up to 100 ng/mL and CK-MM up to 5000 ng/mL did not interfere. In the assay for CK-BB we used an 125I-labeled, reduced, and alkylated monoclonal antibody specific for the B subunit of CK-BB, and removed bound isoenzyme with a second immobilized monoclonal antibody specific for a different epitope on the B subunit. Total incubation time for this assay was 5 h. Intra-assay CV was 7.5 to 20% between 0.1 and 1000 ng/mL. CK-MB up to 1000 ng/mL and CK-MM up to 100 000 ng/mL did not interfere. Inter-assay CVs in all three assays varied from 9 to 21%.
Ligand displacement immunoassay: a novel enzyme immunoassay demonstrated for measuring theophylline in serum.
Authors: Hinds J A , Pincombe C F , Kanowski R K , Day S A , Sanderson J C , Duffy P
Published: January 2020

We describe a ligand displacement immunoassay for measurement of theophylline in serum or plasma and show it to be clinically useful. A conjugate of theophylline-specific antiserum covalently bound to micro-crystalline cellulose and a beta-galactosidase-labeled theophylline derivative is prepared as a lyophilized reagent. Sample is added to the conjugate and, after 5-min incubation at room temperature, the bound and displaced enzyme-ligand are separated by brief centrifugation. The enzyme activity of the displaced enzyme-ligand is measured on a spectrophotometer or centrifugal analyzer. Linear calibration curves are obtained with appropriate sample dilution, allowing generation of the standard curve with a saline zero reference and a single calibrator. Performance of the assay compares favorably with that of other theophylline assays; comparison studies with use of 145 clinical specimens gave a coefficient of correlation with EMIT of 0.97.
Two new methods for separating and quantifying bone and liver alkaline phosphatase isoenzymes in plasma.
Authors: Rosalki S B , Foo A Y
Published: January 2020

We describe two new methods for the separation and quantification of the bone and liver isoenzymes of alkaline phosphatase (EC 3.1.3.1) in plasma. In the first, we use wheat-germ lectin to precipitate the bone isoenzyme. About 80% of this, but minimal liver isoenzyme, is precipitated. The activity of the bone isoenzyme is calculated from measuring the alkaline phosphatase activity in the precipitate, that of liver alkaline phosphatase by subtracting the activity of the bone isoenzyme from total alkaline phosphatase activity. The liver fraction will also contain biliary, intestinal, and placental alkaline phosphatase if these are present in the original plasma, but correction for such activity is readily made. In the second method, samples are separated on cellulose acetate membranes that, before electrophoresis, have been soaked in buffer containing wheat-germ lectin. The bone isoenzyme is retarded and clearly separated from the liver fraction, allowing these isoenzymes to be quantified by densitometry. Both methods are rapid, reproducible, and suitable for use in the diagnostic laboratory.
Specific estimation of 24,25-dihydroxyvitamin D in plasma by gas chromatography-mass spectrometry.
Authors: Coldwell R D , Trafford D J , Makin H L , Varley M J , Kirk D N
Published: January 2020

This paper describes a specific mass-fragmentographic method, involving a stable-isotope-labeled internal standard, for measurement of 24,25-dihydroxyvitamin D in human plasma. Vitamin D metabolites were rapidly extracted from plasma by using Sep-Pak C18 cartridges and separated into fractions on Sep-Pak SIL cartridges. The polar fraction, containing the dihydroxylated metabolites, was further purified by "high-performance" liquid chromatography on Zorbax SIL. The fraction containing 24,25-dihydroxyvitamin D was collected, evaporated, and converted to the 24:25-cyclic n-butyl boronate-3-trimethylsilyl ether derivative before analysis by gas chromatography-mass spectrometry. The intensity of the mass fragment (m/z 449, m/z 455 for the hexadeuterated internal standard) arising from the loss of one of the angular methyls and the 3-silanol group [( M-90-15]+) was monitored. The minimum limit of detection for this method is about 0.1 microgram/L. Inter- and intra-assay reproducibility was acceptable, and analytical recovery of added 24,25-dihydroxyvitamin D3 over the concentration range 1.0 to 5.0 micrograms/L was quantitative. Concentrations of 24,25-dihydroxyvitamin D3 in plasma of 21 apparently healthy volunteers were between 0.55 and 5.39 micrograms/L, higher values being obtained after prolonged exposure to the sun. No 24,25-dihydroxyvitamin D2 could be detected in any plasma sample examined.
Electrothermal atomic absorption spectrometric determination of aluminum in serum with a new technique for protein precipitation.
Authors: Brown S , Bertholf R L , Wills M R , Savory J
Published: January 2020

We have studied the electrothermal atomic absorption measurement of aluminum in serum samples by direct analysis with standard additions and the use of a matrix modifier. We have also measured aluminum by analysis of the supernate after pretreatment of serum with concentrated nitric acid to precipitate proteins, and have compared the results obtained by these two techniques. Both appear to eliminate interferences arising from the serum matrix. We quantified the aluminum by utilizing a stabilized temperature (L'vov) platform. Within-run precision (CV) for the standard-additions method was 16.6% (means = 6.5 micrograms/L) and 6.0% (means = 86.8 micrograms/L) and for the protein precipitation method was 10.1% (means = 10.9 micrograms/L) and 4.2% (means = 88.5 micrograms/L). Linearity of the standard curve extended from 0 to 120 micrograms/L for the standard-additions method and from 0 to 100 micrograms/L for the protein precipitation method. Samples from 38 patients were analyzed by both techniques, and linear regression analysis yielded the equation y (protein precipitation) = 1.02 X (standard additions) + 2.04.
Automated measurement of amylase isoenzymes with 4-nitrophenyl-maltoheptaoside as substrate and use of a selective amylase inhibitor.
Authors: Okabe H , Uji Y , Netsu K , Noma A
Published: January 2020

We automated a kinetic procedure for determining amylase isoenzymes in serum and urine samples. We used 4-nitro-phenylmaltoheptaoside as substrate and a selective amylase inhibitor with the Abbott-VP bichromatic system. By use of the maximum differences between pancreatic (P) and salivary (S) amylase activities remaining after inhibition by the selective inhibitor and by use of the linear range, a one-point standard method for calibration is proposed for determining amylase activities between about 50 and 1500 U/L when the P/S ratio exceeds 0.2. Results correlated well with those by electrophoresis and the Phadebas method (r = 0.99 for both pancreatic and salivary amylase). Reproducibilities (CVs) were 1.5% to 5.5% for pancreatic amylase and 1.4% to 3.3% for salivary amylase in serum, 0.8% to 2.0% for pancreatic amylase and 0.8% to 2.3% for salivary amylase in urine.
Improved liquid-chromatographic determination of haloperidol in plasma.
Authors: Dhar A K , Kutt H
Published: January 2020

This method for determination of haloperidol in plasma is based on "high-performance" isocratic liquid chromatography with the use of a C8 bonded reversed-phase column at room temperature. Haloperidol and the internal standard (chloro-substituted analog) are extracted from alkalinized plasma into isoamyl alcohol/heptane (1.5/98.5 by vol) and back-extracted into dilute H2SO4. The aqueous phase is directly injected onto the column. The mobile phase is a 30/45/25 (by vol) mixture of phosphate buffer (16.5 mmol/L, pH 7.0), acetonitrile, and methanol. Unlike other liquid-chromatographic procedures for haloperidol, commonly used psychotropic drugs do not interfere. Analysis can be completed within an hour. The procedure is extremely sensitive (1.0 microgram/L) and is well reproducible (CV 5.6% for a 2.5 micrograms/L concentration in plasma).
Improved detection of oligoclonal IgG in cerebrospinal fluid by isoelectric focusing in agarose, double-antibody peroxidase labeling, and avidin-biotin amplification.
Authors: Olsson T , Kostulas V , Link H
Published: January 2020

To demonstrate oligoclonal IgG bands (I) in unconcentrated cerebrospinal fluid, we used isoelectric focusing in agarose followed by protein transfer to cellulose nitrate membrane, double-antibody peroxidase labeling, and avidin-biotin amplification. I can be reliably seen after isoelectric focusing of 5-microL specimens containing 125 ng of IgG (25 mg/L). Thus the technique is more sensitive than others (e.g., silver staining) and more reliable than radioimmunofixation. When we used this technique with fluids from 62 patients with multiple sclerosis and infectious disease of the central nervous system, 84% displayed I, a percentage not increased when the same specimens were concentrated to 3.5 g of IgG per liter, examined by agarose isoelectric focusing, and stained with Coomassie Blue. Results for 53 patients with tension headache and psychoneurosis were all negative. By obviating the need to concentrate samples of cerebrospinal fluid the present method is a useful, sensitive alternative for demonstrating I.
Carboxyhemoglobin and oxygen affinity of human blood.
Authors: Rovida E , Niggeler M , Carlone S , Samaja M
Published: January 2020

We determined normal human blood p50 at various pH values (range 7.0 to 7.6) as a function of the proportion of carboxyhemoglobin (COHb) in total hemoglobin, from 0 to 23%. The d(log p50)/d[COHb] coefficient is 0.00848, independent of pH and 2,3-diphosphoglycerate. The derived equation allows the calculation of p50 as a function of COHb with an approximation of +/- 0.54 mmHg (about 72 Pa), and can be combined with other calculations (Clin Chem 27:1856-1861, 1981; Clin Chem 29:110-114, 1983) to predict p50 under any condition of pH within the range 7.0-7.6, ratio of [2,3-diphosphoglycerate] to [total hemoglobin] (range 0.3-2.5), pCO2 (range 20-90 mmHg), temperature (range 19-43 degrees C), and COHb (range 0-23%).
Raising monospecific antibodies by use of protein components prestained with Remazol Brilliant Blue and separated by disc electrophoresis on polyacrylamide gel.
Authors: Saoji A M , Jad C Y , Yemul V L , Khare P M , Kelkar S S
Published: January 2020

We have reported (Clin Chem 29: 42-44, 1983) that prestaining with Remazol Brilliant Blue permits direct visualization of serum components on disc electrophoresis, and apparently purifies the proteins well. Here we have cut out the bands corresponding to the prestained albumin and transferrin after disc electrophoresis of normal human serum proteins, eluted some individual proteins into saline, and assessed their purity by immunoelectrophoresis and two-dimensional crossed immunoelectrophoresis against polyvalent antihuman serum. These two techniques indicated purity of these antigens. We inoculated rabbits with the eluates containing the pure antigens, and tested the resulting antibodies for monospecificity by immunoelectrophoresis, rocket electrophoresis, and single radial immunodiffusion. From the results we conclude that the antibodies raised against each component were monospecific, and that this is a simple, economical, rapid, and reliable method for obtaining a pure fraction of serum protein for use as an antigen.
Assessment of protein-calorie malnutrition.
Authors: Haider M , Haider S Q
Published: January 2020

We critically review the various methods for assessing protein--calorie malnutrition. These tests are lacking in sensitivity and specificity, and currently no single one can be used as a reliable indicator of malnutrition. However, a combination of several of them can be used as prognostic indicators and are of help in selecting patients who may benefit from nutritional support. Body-composition analyses and functional tests hold the promise of greater applicability in the future. Newer and more nearly accurate tests for use in diagnosis of protein-calorie malnutrition as well as for objectively monitoring short-term changes in response to nutritional repletion are badly needed. Despite a lack of consensus on the desirability of objective nutritional assessment, we expect the use of these procedures in hospitals to increase.
Associations between serum gamma-glutamyltransferase and apolipoproteins: relationships with hepatobiliary diseases.
Authors: Artur Y , Wellman-Bednawska M , Jacquier A , Siest G
Published: January 2020

We studied the association between gamma-glutamyltransferase (GGT) and apolipoproteins A or B in serum of 42 patients with various hepatobiliary diseases. Binding of the enzyme to apolipoprotein A is not related to a clearly defined disease, but appears to be mainly influenced by the ratio of total cholesterol to GGT activity. An important fraction of GGT activity is associated with apolipoprotein B in patients with icteric or anicteric cholestasis. Conversely, in noncholestatic patients, the percentage of apolipoprotein B-bound GGT activity is low. Addition of the "heavy" form of GGT, obtained by solubilizing the membrane-bound enzyme with detergents, to a serum with low GGT activity led to the binding of the enzyme only to apolipoprotein A. The "light" form of GGT, obtained by limited proteolysis of the "heavy" form and added to the same serum, did not bind to either apolipoprotein A or apolipoprotein B. Thus, the association between the serum enzyme and apolipoprotein A apparently results from nonspecific aggregation of the amphiphilic "heavy" form of the enzyme. The origin of the apolipoprotein B-GGT complexes found in cholestatic patients needs further investigation.
Sex- and age-related differences in bilirubin concentrations in serum.
Authors: Rosenthal P , Pincus M , Fink D
Published: January 2020

The relation between age and sex and the concentration of bilirubin in serum was evaluated in 6740 men and 11 215 women, ages 13 to 96 years. Mean serum bilirubin concentrations in the men significantly exceeded values in the women over all age groups examined. Further, mean serum bilirubin concentrations were greatest both in males and females in the 19-24 years age group and then declined to former values, which persisted throughout life. Pearson correlation coefficients for bilirubin with liver function indices (albumin and total protein) and with hemoglobin were low in all ages and in both sexes, suggesting that bilirubin concentrations do not correlate with those liver functions not directly concerned with bile pigment processing.
Carbon monoxide in blood: an improved microliter blood-sample collection system, with rapid analysis by gas chromatography.
Authors: Vreman H J , Kwong L K , Stevenson D K
Published: January 2020

We examined the sensitive assay for carboxyhemoglobin based on reaction with K3Fe(CN)6 and gas chromatography of the liberated CO. Our improvements included increased baseline stability, shorter analysis time, and simpler standardization. EDTA-containing Vacutainer Tubes (lavender-stoppered) increase the carboxyhemoglobin content of blood stored in them. The carboxyhemoglobin content of blood stored in capillary tubes containing solid heparin and saponin remained stable for two weeks. Using our improved procedures, we measured the carboxyhemoglobin content of blood from adults and neonates collected via venipuncture or heel or fingersticks. We observed no significant difference in carboxyhemoglobin content of blood obtained by venipuncture or heel stick for premature infants, 0.19 +/- 0.04 vs 0.18 +/- 0.03 mL of CO per 100 mL of blood, respectively (mean +/- SD). Nonsmoking adults (n = 19) had CO values (mean +/- SD) of 0.19 +/- 0.03 and 0.17 +/- 0.04 mL per 100 mL of blood, and smoking adults (n = 7) gave CO values of 0.96 +/- 0.49 and 0.91 +/- 0.49 mL/dL, for venipuncture and fingerstick, respectively.
Occult causes of hypokalemia.
Authors: Walmsley R N , White G H
Published: January 2020

Most causes of hypokalemia are obvious from the clinical picture and the values for plasma electrolytes. In cases with obscure etiology, a pretreatment estimation of urinary potassium and chloride often helps lead the clinician into new and fruitful avenues of clinical investigation. Here we present four cases of hypokalemia in which the pathogenesis was initially enigmatic but was clarified somewhat by the determination of the urinary electrolytes. These simple, inexpensive investigations were initiated by the clinical chemistry laboratory in each case. The results encouraged the physicians to consider further clinical investigations, which led to a definitive diagnosis, before invoking expensive hormonal analyses.
Formate concentrations in a case of methanol ingestion.
Authors: Shahangian S , Robinson V L , Jennison T A
Published: January 2020

An eight-month-old infant ingested at least 3.5 g of methanol when he accidentally received 5 mL of amoxicillin suspended in 70% methanol. The serum methanol concentration 8 h later was 9.7 mmol/L (310 mg/L) and the formate concentration 23 mmol/L (1.0 g/L). At 18 h after the ingestion, total CO2 had decreased to 6.8 mmol/L. Throughout the second day, 21-32 h after the ingestion, the methanol concentration was 2.8-3.4 mmol/L (90-110 mg/L) and that of formate was 31-33 mmol/L (1.4-1.5 g/L). On the third day, 46 h after the ingestion, methanol was not detected and the formate concentration had declined to 16 mmol/L (720 mg/L). The patient was treated with activated charcoal 7 h after the ingestion and with ethanol, administered both orally and intravenously, 21 h after the ingestion. No abnormalities of the infant's eyes were noted upon ophthalmological examination approximately 55 h after the incident.
Optical detection of antibody-antigen reactions at a glass-liquid interface.
Authors: Sutherland R M , Dähne C , Place J F , Ringrose A S
Published: January 2020

We describe an optical technique for detecting and monitoring antibody-antigen reactions at a solid-liquid interface. The antibody is covalently immobilized onto the surface of either a planar (microscope slide) or cylindrical (fibre optic) waveguide made of fused quartz. The reaction of immobilized antibody with antigen in solution is detected through use of the evanescent wave component of a light beam, which has a characteristic depth of penetration of a fraction of a wavelength into the aqueous phase, thus optically interacting primarily with substances bound (or located very close) to the interface and only minimally with the bulk solution. This resulting in-situ spatial separation of the antibody-bound from free antigen precludes a formal separation step and allows the reaction to be monitored kinetically. An immunoassay for methotrexate by absorption spectrometry achieved a detection limit of about 270 nmol/L; binding of methotrexate by immobilized antibody was monitored by the decrease in transmittance at 310 nm. A two-site immunofluorometric assay for human IgG could detect as little as 30 nmol/L; binding of fluorescein-labeled antibody was monitored by the increase in signal above 520 nm (lambda ex = 495 nm). With both immunoassays the signal-generating phase was monitored kinetically and was completed within 15 min.
Total hydrolyzable glycerol in amniotic fluid, and its relationship to fetal lung maturity.
Authors: Siegel L , Walker S I , Robin N I
Published: January 2020

We describe an enzymic quantification of total hydrolyzable glycerol in amniotic fluid. An extract of amniotic fluid is hydrolyzed in mild alkali, without pretreatment with lipase. The resulting glycerol (some of which may be derived from trace amounts of triglyceride) is then enzymatically phosphorylated with adenosine 5'-[gamma 32P]triphosphate to yield glycerol [gamma 32P]phosphate. After removal of excess [gamma 32P]ATP by charcoal, the radioactivity of the glycerophosphate is measured in a liquid scintillation counter. The close correlation (r = 0.96) we found between total hydrolyzable glycerol and phosphatidylglycerol indicates that the contribution of triglyceride to the value for total glycerol is inconsequential. This method is less time consuming and more precise than the method for phosphatidylglycerol.
Chick-Lit Pasifika-Style or How to B(l)end the Formula: Lani Young’s Scarlet Series
Authors: Fresno-Calleja Paloma
Published: January 2020

This article focuses on Scarlet Lies (2015), Scarlet Secrets (2015), and Scarlet Redemption (2019), the popular romance series by Samoan writer Lani Wendt Young. The novels deploy the recognizable chick-lit formula to narrate the predicaments and romantic adventures of a young Samoan woman in what could be defined, following Selina Tusitala Marsh, as “‘Chick Lit’ Pasifika-style” (“Aotearoa Reads”). My main argument is that Young b(l)ends the conventions of chick lit both by hybridizing some of its defining features and by repoliticizing the formula. While dealing with commonplace preoccupations of chick-lit heroines, the novels serve as effective tools for social commentary as they raise criticism toward both Samoan and western societies, reflect on the neocolonial and neoliberal structures affecting the lives of her young Samoan characters, and introduce discussions on culturally specific issues.
Patient-reported symptoms following diagnosis in esophagus cancer patients treated with palliative intent
Authors: Davis Laura E , Gupta Vaibhav , Allen-Ayodabo Catherine , Zhao Haoyu , Hallet Julie , Mahar Alyson L , Ringash Jolie , Doherty Mark , Kidane Biniam , Darling Gail , Coburn Natalie G
Published: January 2020

The majority of patients with esophagus cancer have advanced-stage disease without curative options. For these patients, treatment is focused on improving symptoms and quality of life. Despite this, little work has been done to quantify symptom burden for incurable patients. We describe symptoms using the Edmonton Symptom Assessment System (ESAS) among esophagus cancer patients treated for incurable disease. This retrospective cohort study linked administrative datasets to prospectively collected ESAS data of non-curatively treated adult esophagus cancer patients diagnosed between January 1, 2009 and September 30, 2016. ESAS measures nine common cancer-related symptoms: anxiety, depression, drowsiness, lack of appetite, nausea, pain, shortness of breath, tiredness, and impaired well-being. Frequency of severe symptoms (score ≥ 7/10) was described by month for the 6 months from diagnosis for all patients and by treatment type (chemotherapy alone, radiotherapy alone, both chemotherapy and radiotherapy, and best supportive care). A sensitivity analysis limited to patients who survived at least 6 months was performed to assess robustness of the results to proximity to death and resulting variation in follow-up time. Among 2,989 esophagus cancer patients diagnosed during the study period and meeting inclusion criteria, 2,103 reported at least one ESAS assessment in the 6 months following diagnosis and comprised the final cohort. Patients reported a median of three (IQR 2–7) ESAS assessments in the study period. Median survival was 7.6 (IQR 4.1–13.7) months. Severe lack of appetite (53.1%), tiredness (51.1%), and impaired well-being (42.7%) were the most commonly reported symptoms. Severe symptoms persisted throughout the 6 months after the diagnosis. Subgroup analysis by treatment showed no worsening of symptoms over time in those treated by either chemotherapy alone, or both chemotherapy and radiation. Results followed a similar pattern on sensitivity analysis. Patients diagnosed with incurable esophagus cancer experience considerable symptom burden in the first 6 months after diagnosis and the frequency of severe symptoms remains high throughout this period. Patients with this disease require early palliative care and psychosocial support upon diagnosis and support throughout the course of their cancer journey.
Evidences supporting the inclusion of immigrants in the universal healthcare coverage
Authors: Prats-Uribe Albert , Brugueras Sílvia , Comet Dolors , Álamo-Junquera Dolores , Ortega Gutiérrez LLuïsa , Orcau Àngels , Caylà Joan A , Millet Joan-Pau
Published: January 2020

In 2012, the Spanish government enforced a healthcare exclusion policy against undocumented immigrants. The newly elected government has recently derogated this policy. To analyze how this decree could have affected population health, we looked at primary health patients who would have been excluded and compared with a matched sample of non-excluded patients. Potentially excluded patients had decreased odds of: depression, chronic obstructive pulmonary disease, dyslipidaemia, heart failure and hypertension while diabetes mellitus rates were similar to non-excluded. Infectious diseases were more frequent in potentially excluded population (HIV, tuberculosis and syphilis). The exclusion of patients impedes the control of infectious diseases at a community level.
Predictors of high and low mental well-being and common mental disorders: findings from a Danish population-based study
Authors: Santini Ziggi Ivan , Stougaard Sarah , Koyanagi Ai , Ersbøll Annette Kjær , Nielsen Line , Hinrichsen Carsten , Madsen Katrine R , Meilstrup Charlotte , Stewart-Brown Sarah , Koushede Vibeke
Published: January 2020

Background

Mental well-being is fundamental for a good life. Previous literature has examined the predictors of mental disorders and continuous measures of positive mental health. Very few studies have specifically focused on the predictors of different levels of mental well-being, but those that have suggest a different picture. This study aimed to compare socioeconomic and relational/recreational behaviour predictors of different levels of mental well-being as well as common mental disorders (CMDs).

Methods

Data from 3508 adults aged 16+ years old from the Danish Mental Health and Well-Being Survey 2016 were linked to Danish national register-based data. Mental well-being was assessed using the Warwick-Edinburgh Mental Well-being Scale, and information on CMDs was assessed using the Patient Health Questionnaire (PHQ-4). Regression analyses were conducted to estimate the predictors of low and high mental well-being compared to moderate mental well-being and also of CMDs.

Results

Lower socioeconomic position (education, income and employment status) was associated with increased odds of low mental well-being and the presence of CMDs, but did not significantly predict high mental well-being. Relational/recreational behaviours (informal and formal social participation, social support and recreational activity) were associated with reduced odds of low mental well-being and CMDs, and also with increased odds of high mental well-being.

Conclusions

Socioeconomic predictors of high mental well-being do not mirror those of low mental well-being and CMDs, whereas relational/recreational predictors of high mental well-being do mirror those of low mental well-being and CMDs. These findings have important implications for public mental health strategies.
The culturable mycobiota associated with the Mediterranean sponges Aplysina cavernicola, Crambe crambe and Phorbas tenacior
Authors: Bovio Elena , Sfecci Estelle , Poli Anna , Gnavi Giorgio , Prigione Valeria , Lacour Thierry , Mehiri Mohamed , Varese Giovanna Cristina
Published: January 2020

Marine fungi are part of the huge and understudied biodiversity hosted in the sea. To broaden the knowledge on fungi inhabiting the Mediterranean Sea and their role in sponge holobiont, three sponges namely Aplysina cavernicola, Crambe crambe and Phorbas tenacior were collected in Villefranche sur Mer, (France) at about 25 m depth. The fungal communities associated with the sponges were isolated using different techniques to increase the numbers of fungi isolated. All fungi were identified to species level giving rise to 19, 13 and 3 species for P. tenacior, A. cavernicola and C. crambe, respectively. Of note, 35.7% and 50.0% of the species detected were either reported for the first time in the marine environment or in association with sponges. The mini-satellite analysis confirmed the uniqueness of the mycobiota of each sponge, leading to think that the sponge, with its metabolome, may shape the microbial community.
Nomogram for predicting pathological complete response and tumor downstaging in patients with locally advanced rectal cancer on the basis of a randomized clinical trial
Authors: Zhang Jian-Wei , Cai Yue , Xie Xiao-Yu , Hu Hua-Bin , Ling Jia-Yu , Wu Ze-Hua , Lan Ping , Wu Xiao-Jian , Huang Mei-Jin , Wang Hui , Kang Liang , Zhou Zhi-Yang , Wang Jian-Ping , Deng Yan-Hong
Published: January 2020

Background

Preoperative fluoropyrimidine with radiotherapy was regarded as the standard of care for locally advanced rectal cancer (LARC). The model for predicting pCR in LARC patients was based on standard treatment only. This study aimed to establish a nomogram with pretherapeutic parameters and different neoadjuvant regimens for predicting pathologic complete response (pCR) and tumor downstaging or good response (ypT0-2N0M0) after receiving neoadjuvant treatment in patients with LARC based on a randomized clinical trial.

Methods

Between January 2011 and February 2015, 309 patients with rectal cancer were enrolled from a prospective randomized study (NCT01211210). All pretreatment clinical parameters were collected to build a nomogram for predicting pCR and tumor downstaging. The model was subjected to bootstrap internal validation. The predictive performance of the model was assessed with concordance index (C-index) and calibration plots.

Results

Of the 309 patients, 53 (17.2%) achieved pCR and 132 (42.7%) patients were classified as tumor downstaging with ypT0-2N0M0. Based on the logistic-regression analysis and clinical consideration, tumor length (P = 0.005), tumor circumferential extent (P = 0.036), distance from the anal verge (P = 0.019), and neoadjuvant treatment regimen (P < 0.001) showed independent association with pCR following neoadjuvant treatment. The tumor length (P = 0.015), tumor circumferential extent (P = 0.001), distance from the anal verge (P = 0.032), clinical T category (P = 0.012), and neoadjuvant treatment regimen (P = 0.001) were significantly associated with good tumor downstaging (ypT0-2N0M0). Nomograms were developed to predict the probability of pCR and tumor downstaging with a C-index of 0.802 (95% confidential interval [CI], 0.736–0.867) and 0.730 (95% CI, 0.672–0.784). Internal validation revealed good performance of the calibration plots.

Conclusions

The nomogram provided individual prediction responses to different preoperative treatment for patients with rectal cancer. This model might help physicians in selecting an optimized treatment, but warrants further external validation.
Aging Blunts Sympathetic Neuron Regulation of Motoneurons Synaptic Vesicle Release Mediated by β1- and α2B-Adrenergic Receptors in Geriatric Mice
Authors: Wang Zhong-Min , Rodrigues Anna Carolina Zaia , Messi María Laura , Delbono Osvaldo
Published: January 2020

This study was designed to determine whether and how the sympathetic nervous system (SNS) regulates motoneuron axon function and neuromuscular transmission in young (3–4-month) and geriatric (31-month) mice. Our approach included sciatic-peroneal nerve immunolabeling coregistration, and electrophysiological recordings in a novel mouse ex-vivo preparation, the sympathetic-peroneal nerve-lumbricalis muscle (SPNL). Here, the interaction between the motoneuron and SNS at the neuromuscular junction (NMJ) and muscle innervation reflect the complexity of the living mouse. Our data show that electrical stimulation of the sympathetic neuron at the paravertebral ganglia chain enhances motoneuron synaptic vesicle release at the NMJ in young mice, while in geriatric mice, this effect is blunted. We also found that blocking β-AR prevents the sympathetic neuron from increasing NMJ transmission. Immunofluorescence coexpression analysis of immunolabeled ARs with choline acetyltransferase-, tyrosine hydroxylase-, or calcitonin gene-related peptide immunoreactive axons showed that α2B-AR is found mainly in sympathetic neurons, β1-AR in sympathetic- and motor-neurons, and both decline significantly with aging. In summary, this study unveils the molecular substrate accounting for the influence of endogenous sympathetic neurons on motoneuron-muscle transmission in young mice and its decline with aging.