bluuebunny/crossref_metadata_2025_split huggingface dataset:
Trace-Element Contamination in Biopsies of the Liver
Authors: Versieck J , Speecke A , Hoste J , Barbier F 
Published: January 2020

Abstract
Contamination by trace elements during collection of liver biopsies has been investigated qualitatively and quantitatively. Menghini needles for percutaneous liver biopsy and disposable surgical blades were irradiated in a nuclear reactor until their constituents had a high specific activity. Sampling of liver biopsies was simulated in vitro with use of the irradiated instruments. Under these experimental conditions, radioactivity found in the samples corresponds to contaminations as may be expected in clinical practice. The results demonstrate that needle biopsies are heavily contaminated by numerous trace elements and unsuitable for trace-element analysis. Liver biopsies taken during laparotomy, with a steel surgical blade, are markedly less contaminated but still not acceptable for determinations of some trace elements, especially chromium and nickel.
Determination of Serum and Urinary Phenylalanine by Gas Chromatography
Authors: Shihabi Z K , Summer G K 
Published: January 2020

Abstract
Phenylalanine in serum and urine was determined by gas chromatography after it was converted, by action of nitrous acid, to the corresponding hydroxy acid, phenyllactic acid. After extraction with ether, the phenyllactic acid was derivatized with bis(trimethylsilyl)trifluoroacetamide under mild conditions, and the product was injected directly into the gas chromatograph. The precision of the method was verified by recovery studies and by comparison with the results of quantitative analysis of phenylalanine on an amino acid analyzer. Urine specimens from normal infants and children and from patients with phenylketonuria were analyzed by this method to show that the procedure is applicable to diagnosis of the disorder.
Intercomparison of Results Obtained with Five Commercial Diffusion Plates Supplied for Quantitation of Immunoglobulins
Authors: Hosty Thomas A , Hollenbeck Mary , Shane Shelia 
Published: January 2020

Abstract
Results obtained with five commercial sources of quantitative immunoglobulin plates for IgG, IgA, and IgM varied widely. Preliminary evidence suggests that the international reference serum supplied by the National Institute of Health should be used to standardize commercial reference sera, because the labeled values for immunoglobulins on such sera are of questionable reliability.
Comparison of Results for Three Methods of Hemoglobin S Identification
Authors: Hicks Edward J , Griep John A , Nordschow Carleton D 
Published: January 2020

Abstract
We present comparative results of three diagnostic tests for identification of hemoglobin S, performed on specimens from a total of 4,739 persons. A simple, rapid, and economical procedure for cellulose acetate electrophoresis was more efficient than either the "Sickledex" test (a dithionite test) or the metabisulfite reduction test. This is an important consideration as a minimum requirement for effective therapy and genetic counseling. We propose electrophoresis of hemoglobin on cellulose acetate as a primary screening procedure—with verification of positive samples by solubility tests—and discuss its feasibility.
Concentrations in Serum and Urinary Excretion of Guanidine, 1-Methylguanidine, and 1,1-Dimethylguanidine in Chronic Renal Failure
Authors: Stein Israel M , Micklus Michael J 
Published: January 2020

Abstract
Guanidine (G), 1-methylguanidine (MG), and 1,1-dimethylguanidine (DMG) have long been implicated as uremic "toxins." A method has been developed for determining G, MG, and DMG in serum and urine. Specimens were chromatographed on carboxylate resin, with use of 1 molar NaOH, and quantitated colorimetrically with a modification of the Voges— Proskauer reaction. The mean values for G and MG in the serum of uremic patients were 0.3 and 0.4 mg per liter, respectively. DMG was not detected. Although the urinary excretion of MG is significantly increased in renal failure, the concentrations of G, MG, and DMG in serum are not markedly increased, and it is therefore unlikely that G, MG, or DMG contribute to the toxic manifestations of the uremic syndrome.
Determination of Total Organic Acids in Urine by Extraction with Organic Solvents
Authors: Kesner Leo , Yao Tsai-Tse , Dell Ralph B 
Published: January 2020

Abstract
Metabolic carboxylic acids are extracted, with a mixture of equal volumes of t-amyl alcohol—chloroform, from an acidified sample of as little as 200 µl of urine that has been adsorbed to a short column of silica gel. Total acid in the extract is measured by titration with tetramethylammonium hydroxide (10 mmol/liter) to a phenolphthalein end point. There is no interference from protein, creatinine, creatine, bicarbonate, or amino acids, and no pretreatment of the sample is required. Results compared well (r = 0.94) with those obtained by the Palmer—Van Slyke method for total organic acids. This procedure should prove useful as a simple, rapid screening test for those metabolic disturbances and inborn errors of metabolism characterized by increased excretion of organic acids.
Radioimmunoassay of Human Chorionic Somatomammotropin in Serum, Amniotic Fluid, and Urine
Authors: Moser Russell J , Hollingsworth Dorothy R 
Published: January 2020

Abstract
A method is described for measurement of human chorionic somatomammotropin (HCS) by use of a double-antibody technique, for concentrations ranging from 2 ng/ml to 20 µg/ml. The cross-reactive characteristics of rabbit anti-human HCS serum No. CT 3399 from NIAMD are explored. A dilution plan is presented utilizing a standard curve from 0.75 to 80 ng/ml. Concentrations (mean and ranges) for HCS in maternal serum (evaluated every four weeks during pregnancy), umbilical cord serum, serum from babies, amniotic fluid, and urine are given.
Modified Pisano Method for Estimating Urinary Metanephrines
Authors: Gupta R N , Price D , Keane P M 
Published: January 2020

Abstract
The Pisano method [Clin. Chim. Acta 5, 406 (1960)] for estimating urinary metanephrine, used in the screening of hypertensive persons for pheochromocytoma, has been modified by replacing ion-exchange chromatography with differential solvent extraction. An internal standard is incorporated to correct for procedural losses. Interference from some related compounds is negligible. Normal-range values obtained for various age groups by the present method compare well with those obtained by Pisano’s procedure, but are higher than values reported for more specific methods.
Direct Measurement of Chloride in Sweat with an Ion-Selective Electrode
Authors: Margaret LaVerne Szabo, , Kenny A , Lee Winnie 
Published: January 2020

Abstract
The use of a specific ion electrode for measuring sweat chloride has not been widely accepted because of poor precision and occasional falsely elevated chloride concentrations. We have studied this technique by using the Orion sweat-chloride instrument, and have eliminated these problems by modifying the methodology. An insufficient amount of sweat for determination with the electrode was responsible for both the imprecision and random inaccuracies. The following modifications eliminated these problems: (a) We freshly saturate felt pads with a solution of, per deciliter, 400 mg of pilocarpine nitrate and 1 g of NaHCO3 to replace the electrolyte pads supplied by the Orion Co. (b) The timed iontophoresis period commences after the meter indicates conduction of adequate current. (c) After iontophoresis, sweat is collected for 10 min under a plastic cap held over the induction area. Then chloride concentration is measured with the electrode. With these improvements in technique, the revised procedure should be as reliable as reference methodologies.
Evaluation of S-Benzyl-L-cysteine-4'-nitroanilide as a Substrate for Serum Cystine Aminopeptidase
Authors: Tovey J E , Dawson P J G , Fellowes K P 
Published: January 2020

Abstract
Under appropriate conditions, S-benzyl-L-cysteine-4'-nitroanilide is rapidly hydrolyzed by serum cystine aminopeptidase. The enzyme may be estimated kinetically by determining the rate of liberation of 4-nitroaniline. A simple automated procedure has been devised, and 50 samples of pregnancy sera can be analyzed per hour by use of the LKB 8600 Reaction Rate Analyzer. The correlation coefficient between results of this method and those obtained with L-cystine-di-4'-nitroanilide as substrate was 0.97.
Technical Improvements in Measurement of L-Aspartate: 2-Oxoglutarate Aminotransferase Activity in Serum by Diazonium Salt Coupling
Authors: Morin Leo G , Prox Jerome 
Published: January 2020

Abstract
An improved diazonium coupling procedure is described for measurement of L-aspartate: 2-oxoglutarate aminotransferase (EC 2.6.1.1, formerly termed glutamic oxalacetic transaminase) activity in serum. A relatively pH-stable dye, 5-chloro-2-methoxyaniline-1-diazonium chloride (Fast Red RC) is used, with dimethylformamide and methanol to enhance and stabilize color development. A 15-min incubation is part of the procedure, and color development stabilizes within 5 min.
Application of Inductively-Coupled Plasma Excitation Sources to the Determination of Trace Metals in Microliter Volumes of Biological Fluids
Authors: Kniseley Richard N , Fassel Velmer A , Butler Constance C 
Published: January 2020

Abstract
The inductively coupled plasma is a promising excitation source for the simultaneous multielement determination of trace (nanogram per milliliter) elements in biological fluids. As little as 25 µl of sample fluid (whole blood, serum, or plasma) has been used, with essentially no sample preparation. This technique offers significant advantages over other methods requiring considerable sample handling that may greatly increase the danger of contamination or loss of trace constituents. The precision of the method is typically ±3 to 5%. Because this is an emission spectroscopic technique, a multichannel direct-reading spectrometer allows simultaneous multielement analyses to be made on microliter samples.
Development and Application of a Rapid Cell Sorter
Authors: Hulett H R , Bonner W A , Sweet R G , Herzenberg L A 
Published: January 2020

Abstract
We have further developed our rapid cell analyzer and sorter, so that we can now identify and separate functionally distinct groups of viable cells that have, or can be made to have, either different fluorescence intensities, different light-scattering characteristics, or different combinations of these two variables. In this instrument, cells are observed individually in suspension in the central stream of a very small coaxial liquid jet, as they pass through two laser beams. The jet is later broken into uniform droplets, and those droplets containing the desired cells are charged electrically and then deflected in an electric field. Several thousand cells can be processed per second. Enrichment factors of up to 500 and final purities and viabilities of 90% or more can be routinely achieved. Cell populations present in fractions as small as 1 in 105 or less can be identified. Radioisotope analytical techniques indicate that only a few thousand fluorescent molecules need be present on a cell for it to be detected. The instrument is described and various modes of operation and biological and clinical applications are discussed briefly.
Clinical Laboratory Use of Differential Light Scattering. I. Antibiotic Susceptibility Testing
Authors: Stull V R 
Published: January 2020

Abstract
Differential light scattering (DLS) provides a quantitative representation of bacterial cells in much greater scope and detail than that provided by microscopy and turbidimetry. The information content of the DLS pattern may prove sufficient to provide a basis for most of the tests performed in the clinical bacteriological laboratory. The first application that we have implemented is an automated system with laser illumination, "Differential III," for rapidly determining susceptibility of bacteria to antibiotics. Its high sensitivity detects physiological changes in the generation of cells that metabolize the drugs. Thus the test can be performed in a relatively short time (1.5 h) and at a rate of about 15 specimens per hour. Extensive laboratory testing has been done and hospital evaluation is under way. Data showing the degree of correlation of the Differential III results with other methods are presented. Other applications of DLS in the clinical laboratory are discussed.
Rapid Radioimmunoassay of Triiodothyronine
Authors: Sekadde Christine B , Slaunwhite W Roy , Aceto Thomas 
Published: January 2020

Abstract
The method used in this report is based on the immunological production of a specific antisera to triiodothyronine (T3) in rabbits. Conducted at 4 °C, the radioimmunoassay requires three to five days to complete. Hoping to speed this assay, we investigated the influence of time, temperature, and pH. Incubation at 37 °C and pH 8.0 for 30 min did not deleteriously affect either precision, specificity, reproducibility, or accuracy. Bound and unbound T3 were separated in 10 min by adding polyethylene glycol ("Carbowax 6000") at 0-4 °C. T3 was prevented from binding to thyroxine-binding globulin by the addition of 8-anilino-1-naphthalene sulfonic acid. To minimize the differences in protein concentration between standards and unknowns, we added T3-free serum to all standards. Thus, a simplified and convenient method is described for measurement of T3 that is suitable for clinical use because it is simpler and faster than previously reported methods.
Standard Reference Materials: Standard Quartz Cuvettes for High-Accuracy Spectrophotometry
Authors: Mavrodineanu R , Lazar J W 
Published: January 2020

Abstract
Accurate knowledge of lightpath and parallelism of cuvettes used in spectrophotometry are indispensable parameters that must be determined when accurate transmittance measurements of liquid materials are considered. A description is given of the design and techniques developed at NBS for production of quartz cuvettes (SRM 932) having a nominal radiation pathlength of 10 mm ± 0.03 mm. For each cuvette, pathlength and parallelism are certified with an uncertainty of ±0.0005 mm. The method and instrumentation used to determine these parameters are also described.
A Modified Procedure for Evaluation of the Lecithin/Sphingomyelin Ratio in Amniotic Fluid
Authors: Coch Emily , Meyer John S , Goldman Gordon , Kessler Gerald 
Published: January 2020

Abstract
We describe several modifications of the procedure originated by Gluck et al. [ Amer. J. Obstet. Gynecol. 109, 440 (1971)] for evaluation of amniotic fluid lecithin/sphingomyelin (L/S) ratios. The acetone-precipitation step is eliminated, resulting in a faster extraction procedure and higher concentrations of phospholipids. For faster thin-layer chromatography, we use silica gel-impregnated sheets of glass-fiber and a modified solvent system. For spot detection we use a noncorrosive bismuth subnitrate reagent that is specific for lecithin and sphingomyelin, and an iodine vapor method to confirm the L/S ratio. The bismuth spray also detects significant specimen contamination by phospholipids from plasma or erythrocytes. The L/S ratio is evaluated by visually comparing the relative size and color intensity of the lecithin and sphingomyelin TLC spots. An L/S ratio of 5 or more is consistent with mature pulmonary function and an L/S ratio of less than 2 suggests fetal pulmonary immaturity.
Standardization in Bilirubin Assays: Evaluation of Selected Methods and Stability of Bilirubin Solutions
Authors: Doumas Basil T , Perry Billy Wayne , Sasse Edward A , Straumfjord Jon V 
Published: January 2020

Abstract
Because of the inaccuracy of bilirubin (BIL) determinations, we have investigated some sources of error associated with the most commonly used methods. Inadequate standardization appears to be the most common error. BIL standards in either human serum albumin (HSA), bovine serum albumin (BSA), or pooled human serum were analyzed by these methods. Molar absorptivities (ε) of azobilirubin by the Jendrassik—Gróf procedure were practically identical in all three protein bases. The Meites—Hogg and Malloy—Evelyn methods gave substantially higher ε values with BIL in serum than with BIL in either HSA or BSA. The precision of all methods was good, but best with the Jendrassik—Gróf procedure. BIL standards can be prepared with good reproducibility (CV &lt;0.5%). Standards deteriorate appreciably at -23 °C but are stable at -70 °C. Our data indicate a need for improved commercial BIL controls.
Increased Discontinuation Rates of Anti-TNF Therapy in Elderly Inflammatory Bowel Disease Patients
Authors: de Jong M E , Smits L J T , van Ruijven B , den Broeder N , Russel M G V M , Römkens T E H , West R L , Jansen J M , Hoentjen F 
Published: January 2020

Abstract

Background and Aims
There is paucity of data on safety and efficacy of anti-tumour necrosis factor [TNF] in elderly inflammatory bowel disease [IBD] patients. We aimed to compare the long-term treatment failure rates and safety of a first anti-TNF agent in IBD patients between different age groups [&lt;40 years/40–59 years/≥60 years].

Methods
IBD patients who started a first anti-TNF agent were identified through IBDREAM, a multicentre prospective IBD registry. Competing risk regression was used to study treatment failure, defined as time to drug discontinuation due to adverse events [AEs] or lack of effectiveness, with discontinuation due to remission as a competing risk.

Results
A total of 895 IBD patients were included; 546 started anti-TNF at age &lt;40 [61.0%], 268 at age 40–59 [29.9%], and 81 at age ≥60 [9.1%]. Treatment failure rate was higher in the two older groups (subhazard rate [SHR] age ≥60 1.46, SHR age 40–59 1.21; p = 0.03). The SHR in the elderly [&gt;60] was 1.52 for discontinuation due to AEs and 1.11 for lack of effectiveness. Concomitant thiopurine use was associated with a lower treatment failure rate (SHR 0.78, 95% confidence interval [CI] 0.62–0.98, p = 0.031). Serious adverse event [SAE] rate, as well as serious infection rate, were significantly higher in elderly IBD patients [61.2 versus 16.0 and 12.4 per 1000 patient-years, respectively] whereas the malignancy rate was low in all age groups.

Conclusions
Elderly IBD patients starting a first anti-TNF agent showed higher treatment failure rates, but concomitant thiopurine use at baseline was associated with lower failure rates. Elderly IBD patients demonstrated higher rates of SAEs and serious infections.
Understanding influenza vaccination among Portuguese elderly: the social ecological framework
Authors: Machado Ausenda , Santos Ana João , Kislaya Irina , Larrauri Amparo , Nunes Baltazar 
Published: January 2020

Abstract
This study intended to identify and quantify the social ecological model (SEM) levels associated to seasonal IV uptake in the Portuguese elderly population. Data from the 2014 National Health Survey was restricted to individuals aged 65+ years (n = 5669). Twenty-three independent variables were allocated to the SEM levels: individual, interpersonal, organizational, community and policy. Sex stratified and age adjusted analysis using Poisson regression were performed for each level and for a fitted full model. Relative reduction in pseudo R magnitude measured marginal contribution of each level. For men and women, older groups (85+ vs. 65–69; men, PR = 1.59 and women, PR = 1.56); having 3+ chronic conditions (men, PR = 1.39 and women, PR = 1.35); previous 4 weeks GP and outpatient visits were associated to higher IV uptake. For men, only 2 SEM levels were associated (individual and organizational) while for women the community level was also relevant. Main marginal contribution came from individual (17.9% and 16.3%) and organizational (30.7% and 22.7%) levels. This study highlights the importance of individual characteristics, access and use of health care services for the IV uptake and the sex differential behaviour.
Effects on general health associated with beach proximity in Barcelona (Spain)
Authors: Ballesteros-Olza Mario , Gracia-de-Rentería Pilar , Pérez-Zabaleta Amelia 
Published: January 2020

Abstract
Health benefits of blue spaces have been less studied compared with other urban natural environments. As a type of blue space, beaches are also affected by this lack of evidence, despite their cultural and economic importance in lots of coastal regions all over the world. Based on secondary health data from 3192 participants of the Health Survey of Barcelona 2016, we conducted a logit regression analysis to explore the relationship between people’s general health and beach proximity from their dwelling place, controlling for several health determinants. Our main results suggested that having good general health was less likely for a 1-km increase in the linear distance to the closest beach from people’s dwelling places (OR: 0.93; 95% CI: 0.87, 1.00). Moreover, the probability of having good general health was 45% higher for people living in the first 2 km from the beach (OR: 1.45; 95% CI: 1.01, 2.09), relative to those living &gt;5–10 km from it. Also, these health effects were stronger for people with a low family income. These findings contribute to grow the currently small body of research related to health benefits of beach spaces. Likewise, they encourage fostering the use of these spaces for health promotion in cities, as well as protecting them and improving their accessibility and safety. Further research should lean towards the underlying causes of these health benefits linked to people’s exposure to beach spaces.
Influencing the social impact of financial systems: alternative strategies
Authors: Sim Lee-Anne 
Published: January 2020

Abstract
The social impact of the global financial crisis brought global and domestic financial systems into public focus. While over the last ten years governments have introduced a range of regulatory reforms, there are still low levels of public trust in financial sectors, and academics continue to express their concerns about financial systems and their desire for more influence. This is particularly the case for those framing their evaluation of the quality of financial systems in terms of social values. This article offers those seeking more influence over the social values of financial systems, a fresh perspective on their available strategic options for influencing outcomes. It argues that they should consider strategies aimed at making allies of financial sectors and regulators in influencing change. The main advantage of these alliance strategies is that they address key constraints to influence, as identified in existing scholarship, which are difficult to relax because they are tied to features inherent in financial systems. By addressing these constraints, alliance strategies could increase the likelihood that financial system outcomes align more closely with their preferred social values.