bluuebunny/crossref_metadata_2025 huggingface dataset:
Design and Evaluation of a Filter Fluorometer That Incorporates a Photon-Counting Detector
Authors: Curry Robert E , Pardue Harry L , Mieling Glen E , Santini Robert E
Published: January 2020

We describe the design and evaluation of a filter fluorometer in which a photomultiplier detector is used in the photon-counting mode. Output frequency is shown to be linear with light intensity from 5 Hz to 800 kHz. Comparisons with commercially available instruments show an inherent sensitivity superior to a commercially available filter instrument and comparable to that of a spectrofluorometer. Results are included showing the applicability of the instrument to the kinetic determination of lactate dehydrogenase in serum.
Improved Automated Determination of Bound N-Acetylneuraminic Acid in Serum
Authors: Gerbaut Lucile , Rey Elisabeth , Lombart Christian
Published: January 2020

The method in which thiobarbituric acid is used for sialic acid determination was adapted to a fully automated procedure, in which the chromogen need not be extracted with an organic solvent. The entire procedure, including hydrolysis, requires 35 min and 25 µl of serum for one analysis, but 30 samples can be analyzed per hour. The procedure, slightly modified, can be used to measure as little as 10 mg of bound sialic acid per liter.
Comparison of Two Methods for Radioassay of Vitamin B12 in Serum
Authors: Frenkel Eugene P , White Jerry D , Reisch Joan S , Sheehan Richard G
Published: January 2020

A reference radioassay for vitamin B12 in serum, in which human serum is used as binder and DEAE-cellulose is used to separate free and bound B12, was compared (194 sera) with a packaged kit (" Phadebas B12 Test"), in which intrinsic factor is used as binder and polysaccharide for separation. The correlation coefficient was 0.949. With the kit, added B12 was identifiable, proportional dilution characteristics were excellent, and serial reproducibility was good. The normal range for the reference assay was 200-1000 pg/ml; all B12-deficient patients had values of <165 pg/ml. In a separate study, 38 patients with documented (clinical and laboratory) B12 deficiency had mean serum values of <150 pg/ml by the reference assay, 250 pg/ml by the kit. For the kit, the normal range was 250-1100 pg/ml. All patients with serum values of <150 pg/ml by kit assay were B12 deficient; false positives were seen in the 150-250 pg/mI range.
Comparison of Diagnostic Accuracy of α-Hydroxybutyrate Dehydrogenase Assays by Two Spectrophotometric Procedures
Authors: Spooner Richard J , Goldberg David M
Published: January 2020

α-Hydroxybutyrate dehydrogenase activity was measured in 66 sera from cases of myocardial infarction and 91 sera from cases of hepatobiliary disease by the original procedure at 25 °C [Nature 188, 1110 (1960)] and the revised procedure at 37 °C [Amer. J. Clin. Pathol. 56, 627 (1971)]. The diagnostic accuracy of the two procedures was comparable, but the superior precision of the revised procedure makes it more suitable as a laboratory routine.
Simple, Rapid Determination of Lecithin and Sphingomyelin in Amniotic Fluid
Authors: Blass K G , Thibert R J , Draisey T F
Published: January 2020

We describe a rapid and very sensitive modified determination of lecithin and sphingomyelin in amniotic fluid. It requires 1.5 ml of amniotic fluid and can be done in less than 40 min. Modifications include "Instant Thin Layer Chromatography" plates (Gelman) with a punched disc system of sample application, as well as elimination of the acetone wash steps, and substitution of Rhodamine B dye for the corrosive sulfuric acid char technique of detection. The procedure can be quantified, and exact concentrations of lecithin in amniotic fluid can be determined by a standard addition procedure, or from a standard curve.
Overnight Radioimmunoassay of Human Follicle-Stimulating Hormone
Authors: Brown Loretta P , Besch Paige K , Skelley Dean S , Buttram Veasy C
Published: January 2020

A radioimmunoassay procedure for follicle-stimulating hormone in serum has been developed in which the assay mixture is incubated at 37°C for a total of 22 h, rather than at 4°C for 4-7 days. The within-assay coefficients of variation for the 37°C and 4°C methods, respectively, are 7.7% and 5.0%, while the between-assay variations are 13.8% and 9.9%. Comparison of values for 4°C (x) were related to values for 37°C (y) according to the equation y = 1.2x + 0.8, with a correlation coefficient of 0.98.
Rapid Single-Step Kinetic Colorimetric Assay for Lactate Dehydrogenase in Serum
Authors: Allain Charles C , Henson Carl P , Nadel M Keith , Knoblesdorff Adam J
Published: January 2020

We report an improved kinetic colorimetric system for measuring lactate dehydrogenase activity in serum. In the system a tetrazolium salt, 2-p-iodophenyl-3-p-nitrophenyl-5-phenyl tetrazolium chloride, is used as the chromogenic indicator of dehydrogenase activity, with diaphorase serving as the electron transfer agent. All ingredients required for an assay are combined in a single dry reagent that is stable at room temperature. The method is 2.5 times as sensitive as the ultraviolet method of Wacker and has a dynamic range three times that of the ultraviolet method. Reducing substances in serum do not affect the results. Precision, range of linearity, and stability of reagent after reconstitution are excellent. Results for fresh sera correlated well with those obtained by the "A-Gent" ultraviolet method (Wacker method at 37°C) and with the SMA 12/60.
A Multi-Purpose Miniature Computer for Clinical Applications
Authors: Pardue Harry L , Parker Russell A , Gaw Henry
Published: January 2020

A low-cost miniature computer suitable for multipurpose applications is described. The computer combines digital and analog circuitry to provide a hybrid system that offers both economy and versatility. It uses a stored program to carry out data acquisition and processing operations automatically, and presents results on a numerical display in decimal format. Results are reported for molecular and atomic absorption spectroscopy and for the kinetic determination of enzymes.
Ultramicro Method for Determination of Iron in Serum with the Graphite Furnace
Authors: Olsen Eugene D , Jatlow Peter I , Fernandez Frank J , Kahn Herbert L
Published: January 2020

An ultramicro method is described for determining iron in 50 µl of serum. Hot trichloroacetic acid is used to remove protein and hemoglobin iron, and atomic absorption analysis of 10 µl of the supernatant fluid is carried out with use of a graphite furnace and a specially grooved graphite tube. Results correlate well with those obtained by a conventional flame atomic absorption method for iron that requires a 1-ml sample of serum. A standard graphite tube can be used if the trichloroacetic acid extract is first diluted with water, but we rejected this procedure because of the extra time and effort involved and because of the increased problem of artifactual contamination with iron. When serum was analyzed with no pretreatment, results were higher, probably because of hemoglobin iron present in serum, even serum with no visible hemolysis.
The Usefulness of Laboratory Tests in Health-Screening Programs
Authors: Sackett David L
Published: January 2020

I discuss pitfalls in laboratory-screening programs: regression toward the mean on repeated biochemical determinations; the problem of defining normalcy in the interpretation of laboratory test results; and a remarkable professional myopia in which clinical chemists have, with rare exception, failed to accept responsibility for evaluating whether the programs in which they are engaged are of benefit to patients.
Urinary Homogentisic Acid: Determination by Thin-Layer Chromatography
Authors: Feldman Jerome M , Bowman June
Published: January 2020

A new method is described for qualitative and quantitative determination of urinary homogentisic acid. The method involves extraction of urine with ethyl acetate, thin-layer chromatography of the extract on Silica Gel G, elution of the homogentisic acid into water, and color development with Folin’s phenol reagent. Absorbance is maximum at 750 nm and linear to a concentration of at least 5 mg of homogentisic acid per milliliter of urine. The method is highly specific for homogentisic acid; added gentisic acid, 3,4-dihydroxyphenylacetic acid, ascorbic acid, or L-3,4 dihydroxyphenylalanine do not interfere. The coefficient of variation "in-run" is 5.3%, "between-run" 6.8%. Using this method we have demonstrated a marked variation in day-to-day homogentisic acid excretion in a patient with alcaptonuria. This method, which offers some advantages over existing techniques, should be suitable for use in a clinical laboratory.
Gas-Chromatographic—Mass-Spectrometric Determination of Urinary Acid Profiles of Normal Young Adults on a Controlled Diet
Authors: Witten Thomas A , Levine Steven P , King Julia O , Markey Sanford P
Published: January 2020

Urinary acid metabolic profiles of 21 healthy young adults who were maintained on a palatable standard diet for three days have been studied by combined gas chromatography—mass spectrometry. Means and standard deviations of the excretion rates of individual, identified acids were obtained with the aid of internal standards.
Simultaneous Determination of Carbamazepine ("Tegretol") and Other Anticonvulsants in Human Plasma by Gas—Liquid Chromatography
Authors: Roger Jean-Claude , Rodgers George , Soo Alex
Published: January 2020

A gas chromatographic method in which an on-column reaction with a methylating reagent is used has been developed that permits the simultaneous determination of plasma concentrations of carbamazepine and of some other commonly co-administered anticonvulsant drugs, including phenobarbital, diphenylhydantoin, primidone, and mephenytoin. As little as 0.5 µg of any of these drugs can be determined per milliliter of plasma.
Fluorometric Determination of Plasma 11-Hydroxycorticosteroids. I. Rapid Procedure for Clinical Screening
Authors: Mejer Luis E , Blanchard Roberta C
Published: January 2020

A method proposed by Kitabchi and Kitchell [Anal. Biochem. 34, 529 (1970)] for the fluorometric determination of plasma 11-hydroxycorticosteroids has been modified. It is simplified by eliminating centrifugations, by processing all samples consecutively (rather than in small groups), by using disposable test tubes, and by prealkalinizing standards and blanks as well as plasma samples. Specificity and sensitivity are increased by measuring fluorescence at 520 nm, with an excitation wavelength of 470 nm. Effects of prealkalinization and time of fluorescence development on final cortisol values were studied. Large fluorescence increases are possible after 60 min of fluorescence development. Cortisol recoveries were not changed by the use of phase-separating filter paper nor were cortisol values altered by partial aging of the fluorescence reagent. Sensitivity, specificity, accuracy, and precision of the proposed method are reported.
Fluorometric Determination of Plasma 11-Hydroxycorticosteroids. II. Studies on the Specificity of the Method
Authors: Mejer Luis E , Blanchard Roberta C
Published: January 2020

We have investigated the specificity of the fluorometric method we proposed [Clin. Chem. 19, 710 (1973)] for plasma or serum 11-hydroxycorticosteroid determinations. The principal specific fluorogenic contaminants in the cortisol-containing extract of plasma, as detected by thin-layer chromatography and chemically, were triglycerides and total cholesterol. These contaminants contributed an average of 1.6 µg/dl to the total normal cortisol value. Fatty acids were also found, but did not fluoresce. Nonspecific serum fluorogens were quantitated at 1.3 ± 1.2 µg/dl. Cortisol, corticosterone, and fluorogenic contaminants represented an average of 62.0, 29.1, and 9.9%, respectively, of the total fluorometric plasma cortisol value obtained (expressed in terms of cortisol standard). A ratio of 8.3 ± 2.4 was found for cortisol/corticosterone when each component was determined in terms of its respective standard. Fluorescence scans of the plasma cortisol extract indicated cortisol to be the main component present, accompanied by minor fluorescent contaminants.
Fluorometric Fast Analyzer: Some Applications to Fluorescence Measurements in Clinical Chemistry
Authors: Tiffany T O , Watsky M B , Burtis C A , Thacker L H
Published: January 2020

A fluorometric Fast Analyzer has been developed, based on the GeMSAEC Fast Analyzer principle. Potential applications of a multiple-cuvet fluorometric analyzer are considered. A primary concern must be referencing enzyme activity assays and enzymic substrate analyses. Once adequate referencing techniques are developed, adaptation of analyses can proceed. The advantages of fluorescence procedures are sensitivity, availability of a variety of fluorogenic substrates, and potential perturbation of the excited state for direct physical measurements of interacting species. We describe the development of a direct kinetic assay, with use of 4-methylumbelliferyl phosphate, for human prostatic acid phosphatase; discuss assay of alkaline phosphatase activity with use of the same substrate; and consider the sensitivity of the analyzer as it relates to fluorescence tracer techniques and measurement of fluorescence polarization with the Fast Analyzer.
Measurement of Putrescine, Spermidine, and Spermine in Physiological Fluids by Use of an Amino Acid Analyzer
Authors: Marton Laurence J , Russell Diane H , Levy Carl C
Published: January 2020

Elevated polyamine concentrations in human urine and serum appear to be associated with the presence of many types of cancer. The automated amino acid analyzer lends itself to the rapid separation and measurement of these substances with little sample handling and excellent reproducibility. The ion-exchange resin used was Beckman’s PA-35 (strong sulfonic acid cation exchanger, copolymerization product of styrene-divinylbenzene). Amino acids are bound less strongly to the resin than are the polyamines, and can be removed by first eluting with a buffer of lower ionic strength. If sample injections are overlapped, one sample can be analyzed every hour. We have corroborated that increased concentrations of polyamines appear in the urine of patients with a variety of cancers. Additionally, we have shown increased amounts of polyamines in the serum of patients having a diagnosis of cancer.
Spectrophotometric Quantification of Glycine in Serum and Urine
Authors: Goodwin Jesse F , Stampwala Suresh
Published: January 2020

A method for quantitative determination of glycine in serum and urine, involving degradation to formaldehyde with chloramine-T and subsequent measurement by the Hantzsch reaction or chromotropic acid, has been evaluated and modified. The inhibitory effect of some physiological constituents on the analysis is pointed out. We recommend that samples be purified by passage through a column of ion-exchange resin before analysis. Results for urinary glycine obtained by a single-column amino acid analyzer system compare very favorably with those obtained by the proposed spectrophotometric method. Values for free and total glycine and for glycine/creatinine ratios in the urine of a group of infants are presented along with revised data on the concentration of free glycine in serum.
Gas Chromatography in Diagnostic Biochemistry of Abnormal Valine Metabolism
Authors: Tucker Hugh N , Molinary Samuel V
Published: January 2020

Amino acids in biological fluids can be rapidly and accurately quantitated by gas chromatography. Modification of existing gas-chromatographic techniques allow as little as 25 µl of biological fluids to be analyzed, compatible with sample sizes easily obtained in pediatric studies. Simplified diagnostic biochemical evaluation of a suspected aminoaciduria can be begun at birth, or shortly after. Normal amino acid patterns are compared with those found in a patient with abnormal amino acid concentrations. Gas chromatographic evidence is presented as a diagnostic aid in the evaluation of a patient with abnormal valine metabolism.
Ratiometric Triglyceride Analysis by Use of a Centrifugal Analyzer
Authors: Olson Arthur D , Brennan Richard L
Published: January 2020

We describe a simple, reliable, enzymatic method for triglyceride analysis, in which triolein is used as a standard. Use of a centrifugal analyzer greatly decreases required time and reagent cost. Results correlate well with those obtained by a standard automated continuous-flow method.
Values for Urinary Free Cortisol during Treatment with Amino-Glutethimide for Cushing’s Syndrome
Authors: Schmitt Karl W , Juselius Roger , Hanlon James , Steed David
Published: January 2020

Of the chemical tests used, we found that values for urinary free cortisol had the best clinical correlation and were the most sensitive indicator of cortisol secretion in a patient with Cushing’s syndrome who was treated with amino-glutethimide.
Evaluation of a Rapid Latex-Agglutination Test for Detection of α1-Fetoprotein
Authors: Alpert E , Coston R L
Published: January 2020

A latex-agglutination assay for α-fetoprotein (AFP) has been evaluated and compared to the results obtained by counter-immunoelectrophoresis (CIEP). Both of these tests must be performed on both undiluted and diluted sera, to avoid prozone effects. Agglutination of control latex, coated with normal rabbit gamma globulin, by sera from 8% of hepatoma patients and 18% of patients with other liver diseases makes the test inconclusive in these patients. Nevertheless, there was 88.6% agreement with CIEP in the detection of AFP in a series of 50 hepatoma patients. There were no false positives for sera from 98 patients with other liver diseases or for normal controls. We conclude that latex agglutination is a simple, specific way to screen large numbers of sera for AFP, if all positive results are confirmed by a control latex test and CIEP.
Improved Manual Spectrophotometric Procedure for Determination of Serum Triglycerides
Authors: Gottfried Sidney P , Rosenberg Bernard
Published: January 2020

We have modified the procedure of Levy [Ann. Clin. Lab. Sci. 6, 474 (1972)] for determination of serum triglycerides. The changes consist of using heptane in place of nonane; using concentrated aqueous potassium hydroxide instead of sodium methylate as the saponifying reagent; and a somewhat higher saponification, oxidation, and condensation temperature. Consequently, the yellow dehydrolutidine derivative is determined in a homogeneous solution having an almost linear absorbance up to 3 g/liter.
Defining catchment origins of a geographical bottleneck: Implications of population mixing and phenological overlap for the conservation of Neotropical migratory birds
Authors: Cardenas-Ortiz Laura , Bayly Nicholas J , Kardynal Kevin J , Hobson Keith A
Published: January 2020

Migratory bottlenecks concentrate individuals and populations of Nearctic–Neotropical migrants from across vast breeding areas. The extent to which such concentrations occur has important ramifications for interpreting migratory connectivity and for the vulnerability of populations throughout the annual cycle but investigations of such phenomena are rare. We inferred breeding origins of 11 species of Nearctic–Neotropical migrants captured during fall migration in the Darién region, northwestern Colombia, using feather stable-hydrogen isotope values (δ 2Hf). Our objectives were to determine (1) the extent to which this region acts as a catchment for individuals from across a species’ breeding range, (2) if temporal patterns of arrival arise as a function of migration distance inferred from δ 2Hf, and (3) if phenological differences among species segregate populations. The Darién concentrated populations of 6 species, with individuals potentially derived from 78% to 94% of their respective North American breeding ranges. The catchment area for the remaining 5 species covered 40–72% of breeding ranges, with a bias in origin from the west (e.g., Northern Waterthrush [Parkesia noveboracensis], Swainson’s Thrush [Catharus ustulatus]), north or center (Yellow Warbler [Setophaga petechia]) of their range. Differential timing in the migration of populations occurred in 6 species, generating a degree of temporal segregation. In contrast, peak migration for all species occurred in October, resulting in high overlap among species in their use of the Darién. Overall, our results describe high mixing of populations in the Darién for several species, which, given the region’s highly restricted geographic extent, suggests that a bottleneck effect occurs; however, comparisons with other regions in Central America and northern South America are required. The combination of extensive population mixing and limited temporal segregation over a narrow geographical area suggests that long-distance migrants may be especially vulnerable to events occurring in such regions, including adverse weather conditions and anthropogenic land cover change.
The medicalization of cancer as socially constructed and culturally negotiated
Authors: Fries Christopher J
Published: January 2020

Sociological considerations of medicalization frequently employ a limited use of the term that focuses on the transformation of social phenomena into issues subject to medical control. Informed by a salutogenic perspective, this essay argues that it is possible to understand cancer as having been medicalized. I show that far from exclusively a biophysical issue, the medicalization of cancer is a socially constructed and culturally negotiated process, with a fairly recent historical origin. While changing social relations of healing have led our medico-centric culture to a near single-minded understanding of cancer as a cellular pathology rooted in biology, Antonovsky’s salutogenic perspective instructs that it is possible to understand and control cancer in non-medicalized ways. Indoor radon gas remediation is presented as an illustration of what form salutary cancer control and disease prevention may take.
Accessibility and acceptability of health promotion services in New Zealand for minority refugee women
Authors: Shrestha-Ranjit Jagamaya , Patterson Elizabeth , Manias Elizabeth , Payne Deborah , Koziol-McLain Jane
Published: January 2020

Refugees are forced to flee their native country to escape war or oppression. They are resilient and generally have a high level of motivation to rebuild their lives, as well as to make a meaningful contribution to the host country. However, refugees in general have complex health needs and they often face significant barriers in accessing health services in their host countries. Health promotion has been identified as an effective approach for increasing service utilization by minority populations such as refugees, and contributing to their overall positive health outcomes. This qualitative study examined the accessibility and acceptability of health promotion services for Bhutanese refugee women who resettled in New Zealand. The study consisted of two phases: focus group discussions with 32 Bhutanese women and eight Bhutanese men, followed by individual interviews with 12 health professionals including five nurses, four doctors and three midwives. The data were collected in two regional towns of New Zealand in 2014. The study’s conceptual framework utilized the strategies and actions underpinning the Ottawa Charter for Health Promotion. Findings of this study revealed that Bhutanese women were missing some essential health promotion services, such as antenatal education sessions mainly due to language and cultural barriers. This study recommends to develop health promotion resources in the Nepali language; and to deliver the health promotion sessions by culturally and linguistically competent providers. This study also uncovered resiliency and strengths of Bhutanese women that could be recognized, strengthened and utilized in promoting their health and well-being.
Body mass index and height and risk of cutaneous melanoma: Mendelian randomization analyses
Authors: Dusingize Jean Claude , Olsen Catherine M , An Jiyuan , Pandeya Nirmala , Law Matthew H , Thompson Bridie S , Goldstein Alisa M , Iles Mark M , Webb Penelope M , Neale Rachel E , Ong Jue-Sheng , MacGregor Stuart , Whiteman David C
Published: January 2020

Background

Height and body mass index (BMI) have both been positively associated with melanoma risk, although findings for BMI have been less consistent than height. It remains unclear, however, whether these associations reflect causality or are due to residual confounding by environmental and lifestyle risk factors. We re-evaluated these associations using a two-sample Mendelian randomization (MR) approach.

Methods

We identified single nucleotide polymorphisms (SNPs) for BMI and height from separate genome-wide association study (GWAS) meta-analyses. We obtained melanoma SNPs from the most recent melanoma GWAS meta-analysis comprising 12 874 cases and 23 203 controls. We used the inverse variance-weighted estimator to derive separate causal risk estimates across all SNP instruments for BMI and height.

Results

Based on the combined estimate derived from 730 SNPs for BMI, we found no evidence of an association between genetically predicted BMI and melanoma [odds ratio (OR) per one standard deviation (1 SD) (4.6 kg/m2) increase in BMI 1.00, 95% confidence interval (CI): 0.91–1.11]. In contrast, we observed a positive association between genetically-predicted height (derived from a pooled estimate of 3290 SNPs) and melanoma risk [OR 1.08, 95% CI: 1.02–1.13, per 1 SD (9.27 cm) increase in height]. Sensitivity analyses using two alternative MR methods yielded similar results.

Conclusions

These findings provide no evidence for a causal association between higher BMI and melanoma, but support the notion that height is causally associated with melanoma risk. Mechanisms through which height influences melanoma risk remain unclear, and it remains possible that the effect could be mediated through diverse pathways including growth factors and even socioeconomic status.
Restating The Meaning Of UCD And HCD For A New World Of Design Theories
Authors: Campese Carina , Amaral Daniel Capaldo , Mascarenhas Janaina
Published: January 2020

User-centered design (UCD) or human-centered design (HCD) has become a recognized element of design theory that is gaining increasing prominence in many areas or disciplines related to design. The aim of this paper is to introduce the concept of HCD/UCD in the areas of design so that it contributes to the communication and development of theories in this area. This paper presents a content analysis of HCD/UCD academic literature and demonstrates a lack of agreement on the use of the term ‘user’ or ‘human’: a significant variation of meaning of the terms used, definitions with distinct levels of abstraction, high variation of elements and distinct preference by the acronym usage. A selection of definitions was analyzed and summarized into a framework that considers all levels of abstraction and proposes seven HCD/UCD elements. Finally, recommendations about the use of this framework to bring researchers close to a common understanding about HCD/UCD are presented. This work contributes to bring together knowledge about the theme under a single umbrella and to integrate design theories and methods based on the concept of HCD/UCD. This will facilitate the transdisciplinary and will build up all the knowledge acquired in a single body of knowledge.
Assessing the effectiveness of AS-48 in experimental mice models of Chagas’ disease
Authors: Martín-Escolano Rubén , Cebrián Rubén , Maqueda Mercedes , Romero Desirée , Rosales Maria José , Sánchez-Moreno Manuel , Marín Clotilde
Published: January 2020

Objectives

We report the in vivo trypanocidal activity of the bacteriocin AS-48 (lacking toxicity), which is produced by Enterococcus faecalis, against the flagellated protozoan Trypanosoma cruzi, the aetiological agent of Chagas’ disease.

Methods

We determined the in vivo activity of AS-48 against the T. cruzi Arequipa strain in BALB/c mice (in both acute and chronic phases of Chagas’ disease). We evaluated the parasitaemia, the reactivation of parasitaemia after immunosuppression and the nested parasites in the chronic phase by PCR in target tissues.

Results

AS-48 reduced the parasitaemia profile in acute infection and showed a noteworthy reduction in the parasitic load in chronic infection after immunosuppression according to the results obtained by PCR (double-checking to demonstrate cure).

Conclusions

AS-48 is a promising alternative that provides a step forward in the development of a new therapy against Chagas’ disease.
High prevalence of integrase mutation L74I in West African HIV-1 subtypes prior to integrase inhibitor treatment
Authors: El Bouzidi Kate , Kemp Steven A , Datir Rawlings P , Murtala-Ibrahim Fati , Aliyu Ahmad , Kwaghe Vivian , Frampton Dan , Roy Sunando , Breuer Judith , Sabin Caroline A , Ogbanufe Obinna , Charurat Man E , Bonsall David , Golubchik Tanya , Fraser Christophe , Dakum Patrick , Ndembi Nicaise , Gupta Ravindra K
Published: January 2020

Objectives

HIV-1 integrase inhibitors are recommended as first-line therapy by WHO, though efficacy and resistance data for non-B subtypes are limited. Two recent trials have identified the integrase L74I mutation to be associated with integrase inhibitor treatment failure in HIV-1 non-B subtypes. We sought to define the prevalence of integrase resistance mutations, including L74I, in West Africa.

Methods

We studied a Nigerian cohort of recipients prior to and during receipt of second-line PI-based therapy, who were integrase inhibitor-naive. Illumina next-generation sequencing with target enrichment was used on stored plasma samples. Drug resistance was interpreted using the Stanford Resistance Database and the IAS-USA 2019 mutation lists.

Results

Of 115 individuals, 59.1% harboured CRF02_AG HIV-1 and 40.9% harboured subtype G HIV-1. Four participants had major IAS-USA integrase resistance-associated mutations detected at low levels (2%–5% frequency). Two had Q148K minority variants and two had R263K (one of whom also had L74I). L74I was detected in plasma samples at over 2% frequency in 40% (46/115). Twelve (26.1%) had low-level minority variants of between 2% and 20% of the viral population sampled. The remaining 34 (73.9%) had L74I present at >20% frequency. L74I was more common among those with subtype G infection (55.3%, 26/47) than those with CRF02_AG infection (29.4%, 20/68) (P = 0.005).

Conclusions

HIV-1 subtypes circulating in West Africa appear to have very low prevalence of major integrase mutations, but significant prevalence of L74I. A combination of in vitro and clinical studies is warranted to understand the potential implications.
Effective inhibition of PBPs by cefepime and zidebactam in the presence of VIM-1 drives potent bactericidal activity against MBL-expressing Pseudomonas aeruginosa
Authors: Moya Bartolome , Bhagwat Sachin , Cabot Gabriel , Bou German , Patel Mahesh , Oliver Antonio
Published: January 2020

Objectives

The combination of cefepime and the novel β-lactam enhancer zidebactam (WCK 5222) is under development for the treatment of difficult-to-treat Gram-negative infections. Against MBL-producing pathogens, cefepime and zidebactam induce cell elongation and spheroplast formation, indicating PBP3 and PBP2 dysfunction, respectively, having a potent bactericidal effect as a combination. The objective of the present study was to determine the mechanistic basis of the bactericidal effect of cefepime/zidebactam on MBL-expressing pathogens.

Methods

Pseudomonal PBP-binding affinities of cefepime, zidebactam and imipenem were assessed at different timepoints and also in the presence of purified VIM-1 using a Bocillin FL competition assay. The antibacterial activity of cefepime/zidebactam against three VIM-expressing Pseudomonas aeruginosa isolates was assessed by time–kill and neutropenic mouse lung/thigh infection studies.

Results

Amidst cefepime-hydrolysing concentrations of VIM-1, substantial cefepime binding to target PBPs was observed. High-affinity binding of zidebactam to PBP2 remained unaltered in the presence of VIM-1; however, MBL addition significantly affected imipenem PBP2 binding. Furthermore, the rate of cefepime binding to the primary target PBP3 was found to be higher compared with the imipenem PBP2 binding rate. Finally, complementary PBP inhibition by cefepime/zidebactam resulted in enhanced bactericidal activity in time–kill and neutropenic mouse lung/thigh infection studies against VIM-6-, VIM-10- and VIM-11-expressing P. aeruginosa, thus revealing the mechanistic basis of β-lactam enhancer action.

Conclusions

For the first time ever (to the best of our knowledge), this study demonstrates that in the presence of VIM-1 MBL, β-lactamase-labile cefepime and β-lactamase-stable zidebactam produce effective inhibition of respective target PBPs. For cefepime, this seems to be a result of a faster rate of PBP binding, which helps it overcome β-lactamase-mediated hydrolysis.
A recent starbust in the low surface brightness galaxy UGC 628
Authors: Young J E , Kuzio de Naray Rachel , Wang Sharon X
Published: January 2020

We present the star-formation history of the low surface brightness (LSB) galaxy UGC 628 as part of the MUSCEL program (MUltiwavelength observations of the Structure, Chemistry, and Evolution of LSB galaxies). The star-formation histories of LSB galaxies represent a significant gap in our knowledge of galaxy assembly, with implications for dark matter / baryon feedback, IGM gas accretion, and the physics of star formation in low metallicity environments. Our program uses ground-based IFU spectra in tandem with space-based UV and IR imaging to determine the star-formation histories of LSB galaxies in a spatially resolved fashion. In this work we present the fitted history of our first target to demonstrate our techniques and methodology. Our technique splits the history of this galaxy into 15 semilogarithmically spaced time-steps. Within each time-step the star-formation rate of each spaxel is assumed constant. We then determine the set of 15 star-formation rates that best recreate the spectra and photometry measured in each spaxel. Our main findings with respect to UGC 628 are: (i) the visible properties of UGC 628 have varied over time, appearing as a high surface brightness spiral earlier than 8 Gyr ago and a starburst galaxy during a recent episode of star formation several tens of Myr ago, (ii) the central bar/core region was established early, around 8–10 Gyr ago, but has been largely inactive since, and (iii) star formation in the past 3 Gyr is best characterized as patchy and sporadic.
Proteotoxic stress promotes entrapment of ribosomes and misfolded proteins in a shared cytosolic compartment
Authors: Ghosh Arnab , Williams Loren Dean , Pestov Dimitri G , Shcherbik Natalia
Published: January 2020

Cells continuously monitor protein synthesis to prevent accumulation of aberrant polypeptides. Insufficient capacity of cellular degradative systems, chaperone shortage or high levels of mistranslation by ribosomes can result in proteotoxic stress and endanger proteostasis. One of the least explored reasons for mistranslation is the incorrect functioning of the ribosome itself. To understand how cells deal with ribosome malfunction, we introduced mutations in the Expansion Segment 7 (ES7L) of 25S rRNA that allowed the formation of mature, translationally active ribosomes but induced proteotoxic stress and compromised cell viability. The ES7L-mutated ribosomes escaped nonfunctional rRNA Decay (NRD) and remained stable. Remarkably, ES7L-mutated ribosomes showed increased segregation into cytoplasmic foci containing soluble misfolded proteins. This ribosome entrapment pathway, termed TRAP (Translational Relocalization with Aberrant Polypeptides), was generalizable beyond the ES7L mutation, as wild-type ribosomes also showed increased relocalization into the same compartments in cells exposed to proteotoxic stressors. We propose that during TRAP, assembled ribosomes associated with misfolded nascent chains move into cytoplasmic compartments enriched in factors that facilitate protein quality control. In addition, TRAP may help to keep translation at its peak efficiency by preventing malfunctioning ribosomes from active duty in translation.
Harm Perceptions of E-cigarettes Among Smokers With and Without Mental Health Conditions in England: A Cross-Sectional Population Survey
Authors: Smith Charlie Albert , Shahab Lion , McNeill Ann , Jackson Sarah E , Brown Jamie , Brose Leonie
Published: January 2020

Introduction

E-cigarettes (ECs) may benefit smokers with mental health conditions who are more likely to smoke, and smoke more heavily, than those without mental health conditions. This could be undermined if harm misperceptions in this group are high as is the case in the general population. This study aimed to assess EC harm perceptions relative to cigarettes as a function of mental health status and a variety of characteristics.

Methods

Data were collected from 6531 current smokers in 2016/2017 in household surveys of representative samples of adults. The associations of mental health status (self-reported mental health condition and past year treatment), smoking and EC use characteristics, and characteristics relating to use of potential information sources with harm perceptions of ECs relative to cigarettes (measured by correct response “less harmful” vs. wrong responses “more harmful,” “equally harmful,” “don’t know”) were analyzed with logistic regression.

Results

A similar proportion of smokers without mental health conditions (61.5%, 95% CI 60.1–62.9) and with mental health conditions (both with [61.3%, 95% confidence interval [CI] 58.7–63.8] and without past year treatment [61.5%, 95% CI 58.1–64.7]) held inaccurate EC harm perceptions (all P > 0.05). Being female, nonwhite, aged 25–34 compared with 16–24, from lower social grades (C2, D, and E), not having post-16 qualifications, no EC experience, a daily smoker, unmotivated to quit <1 month, non-internet user and non-broadsheet reader were all associated with more inaccurate harm perceptions (all p < .05).

Conclusions

The majority of smokers in England have inaccurate harm perceptions of ECs regardless of mental health status.

Implications

This study is the first to use a nationally representative sample in order to investigate whether smokers with and without mental health conditions differ with regard to harm perceptions of ECs. Findings show that the majority of smokers in England hold inaccurate harm perceptions of ECs, and this does not differ as a function of mental health status. A number of characteristics associated with disadvantaged groups were significantly associated with inaccurate harm perceptions. These findings highlight the need to improve awareness and understanding among disadvantaged groups regarding the relative harms of ECs compared with tobacco.
The approach for ascertaining a trustee’s duties and liabilities, effectiveness of anti-Bartlett provisions, and equitable compensation for breach of trust or fiduciary duty: Zhang Hong Li & Ors v DBS Bank (Hong Kong) Ltd & Ors [2019] HKCFA 45
Authors: Yee Ching Leung Samuel
Published: January 2020

The decision of the Hong Kong Court of Final Appeal in Zhang Hong Li & Ors v DBS Bank (Hong Kong) Ltd & Ors [2019] HKCFA 45 is important not only to Hong Kong but also to the common law world for several reasons. First, it confirms the effectiveness of anti-Bartlett provisions, a type of clause ubiquitous in trust deeds that negate a trustee’s duty to intervene in the business or management of companies owned by the trust. Secondly, it clarifies that there is no free-standing ‘high level supervisory duty’ owed by a trustee in common law. Thirdly, it lays down an approach for ascertaining a trustee’s duties and liabilities, and limiting the effectiveness of anti-Bartlett provisions. Under the approach advocated by the court, the terms of a trust deed should be taken as a starting point and subsequently an exercise of contractual construction should be conducted. Finally, it sets forth how equitable compensation for a breach of trust or fiduciary duty is to be assessed.
Compartmentalization of enhanced biomolecular interactions for high-throughput drug screening in test tubes
Authors: Zhou Min , Li Weiping , Li Jian , Xie Leiming , Wu Rongbo , Wang Liang , Fu Shuai , Su Wei , Hu Jianyang , Wang Jing , Li Pilong
Published: January 2020

Modification-dependent and -independent biomolecular interactions (BIs), including protein-protein, protein-DNA/RNA and protein-lipid, play crucial roles in all cellular processes. Dysregulation of BIs or malfunction of the associated enzymes results in various diseases, thus they are attractive targets for therapies. High-throughput screening (HTS) can greatly facilitate the discovery of drugs for these targets. Here we describe a HTS drug discovery method, calledcompartmentalization ofenhancedbiomolecular interactions in test tubes (CEBIT). CEBIT uses selective recruitment of biomolecules into phase separated compartments harboring their cognate binding partners as readouts. CEBIT were tailored to detect various BIs and associated modifying enzymes. Using CEBIT-based HTS assays, we successfully identified known inhibitors of the p53/MDM2 interaction and of SUV39H1 from a compound library. CEBIT is simple and versatile, and is likely to become a powerful tool for drug discovery and basic biomedical research.
Neutralizing PD-L1 and PD-L2 Enhances the Efficacy of Immune Checkpoint Inhibitors in Ovarian Cancer
Authors: Miao Yu Rebecca , Thakkar Kaushik N. , Qian Jin , Kariolis Mihalis S. , Wei Huang , Nandagopal Saravanan , Yang Teddy , Diep Anh N. , Cherf Gerald Maxwell , Xu Yu , Moon Eui Jung , Xiao Yiren , Alemany Haizea , Li Tianer , Yu Wenhua , Wei Bo , Rankin Erinn B. , Giaccia Amato J.
Published: January 2020

Immune checkpoint inhibitors targeting the PD-1/PD-L1 pathway have improved for a number of solid tumors. Unfortunately, ovarian cancer represents a major clinical hurdle for immune checkpoint blockade (ICB) with reported low patient response rates. Using IHC staining, we find that PD-L2 is highly expressed in ovarian cancers and other malignancies with sub-optimal response to ICB, and is expressed at low levels in cancers responsive to ICB. Based on this observation, we hypothesized that the elevated expression of PD-L2 produced by both tumor and surrounding stromal cells contributes to immune-suppression. Since PD-L2 has been reported to have a 6- to10-fold higher native binding affinity to PD-1 compared with PD-L1, we hypothesized that high levels of PD-L2 can lead to insufficient blockade of the PD-1 signaling pathway. To overcome the immune repressive activity of PD-L2, we engineered a soluble PD-1 decoy molecule (sPD-1 mutant) that binds and neutralizes both PD-L1 and PD-L2 with a 10,000- and 200- fold improvement in binding affinity, respectively, when compared to wild-type binding to these same molecules. Such enhancement in binding affinity is facilitated by amino acid mutations both within and outside of the binding interface. Furthermore, this high affinity sPD-1 mutant molecule demonstrates superiorin vivoefficacy in multiple cancer models including ovarian cancer where PD-L2 is highly expressed on the cell surface.

One Sentence Summary

Dual Inhibition of PD-L1 and PD-L2 using an affinity enhanced sPD-1 decoy molecule delivers superior antitumor activity when compared with αPD-1 and αPD-L1 antibodies in ovarian cancer.
Selective germline genome edited pigs and their long immune tolerance in Non Human Primates
Authors: Zou Lijin , Zhang Youlai , He Ying , Yu Hui , Chen Jun , Liu Delong , Lin Sixiong , Gao Manman , Zhong Gang , Lei Weicheng , Zhou Guangqian , Zou Xuenong , Li Kai , Yu Yin , Zha Gaofeng , Li Linxian , Zeng Yuanlin , Wang Jianfei , Wang Gang
Published: January 2020

Organ transplantation is the only curative treatment for patients with terminal organ failure, however, there is a worldwide organ shortage. Genetically modified pig organs and tissues have become an attractive and practical alternative solution for the severe organ shortage, which has been made possible by significant progress in xenotransplantation in recent years. The past several decades witnessed an expanding list of genetically engineered pigs due to technology advancements, however, the necessary combination of genetic modifications in pig for human organ xenotransplantation has not been determined. In the current study, we created a selective germline genome edited pig (SGGEP). The first triple xenoantigens (GGTA, B4GAL, and CAMH) knockout somatic cells were generated to serve as a prototype cells and then human proteins were expressed in the xenoantigen knockout cells, which include human complement system negative regulatory proteins (CD46, CD55, and CD59); human coagulation system negative regulatory proteins thrombomodulin (THBD); tissue factor pathway inhibitor (TFPI); CD39; macrophage negative regulatory proteins (human CD47); and natural killer cell negative regulatory human HLA-E. After the successful establishment of SGGEP by the nuclear tranfer, we engrafted SGGEP skin to NHP, up to 25 days graft survival without immunosuppressive drugs was observed. Because a pig skin graft does not impact the success of a subsequent allograft or autograft or vice versa, thus our SGGEP could have a great potential for clinical value to save severe and large area burn patients and the other human organ failure. Therefore, this combination of specific gene modifications is a major milestone and provides proof of concept to initiate investigator-initiated clinical trials (IITs) in severe burn patients with defined processes and governance measures in place and the other clinical application.
Inhibitory effects of Akt on neuronal FoxO4 activation after subarachnoid hemorrhagein vivoandin vitro
Authors: Qi Min , Gao Sheng-qing , Liu Jia-qiang , Han Yan-ling , Yuan Bin , Zhou Xiao-ming , Liu Xi-lin , Zhou Meng-liang , Zheng Lan-rong
Published: January 2020

Secondary brain injury following subarachnoid hemorrhage (SAH) is the critical contributor to the mortality of SAH patients. The underlying mechanisms are poorly understood. In this study, we utilized a mice model of SAH to investigate whether FoxO4 is related to the brain injury after SAH and identified its upstream regulator Akt. Experimental SAH was induced in adult male mice by prechiasmatic cistern injection. Brain FoxO4 protein levels in cytoplasm and nucleaus were examined in the sham-operated controls, and in mice 1h, 6h, 12h, 24h, 3d, and 5d after SAH induction. The Akt inhibitor LY294002 was administered by intracerebroventricular infusion to determine its effects on FoxO4. Moreover, the expression of FoxO4 was also investigated in neurons incubated with hemoglobinin vitro, which was also dertermined after inhibition of Akt. FoxO4 protein expression in the nuclei increased remarkably after SAH. The Akt inhibitor LY294002 induced more FoxO4 nuclear localization after SAHin vivoandin vitro. Our results suggest the activation of FoxO4 after SAH and which was inhibited by the increased phosphorylated Akt (p-Akt).