bluuebunny/crossref_metadata_2025 huggingface dataset:
Exchange bias effect in antiferromagnets containing ferromagnetic clusters
Authors: Pankratova M. L. , Kovalev A. S.
Published: November 2018

This study offers an explanation for the occurrence of magnetization exchange bias in antiferromagnets with ferromagnetic inclusions during pre-cooling the system in a magnetic field. The ferromagnetic (FM) subsystem ordered in this field at the Néel temperature leads to an inhomogeneous state of the antiferromagnetic (AFM) matrix with the finite mean effective field at the FM/AFM interface. This field causes exchange bias in the dependence M = M(H) during further remagnetization of the heterogeneous system. To describe the proposed scenario for such an effect, a simple model of a two-dimensional system with round inclusions of the FM phase was considered. Using numerical calculations and previously obtained analytical results, the study determines magnetization dependencies on the external field, which qualitatively explains the features of exchange bias in experimentally studied heterogeneous systems.
The EPR spectra of a D4h symmetry four-nuclear molecular complex
Authors: Zhuravlev A. V.
Published: November 2018

A study of the EPR spectra of aspin s=1/2 four-nuclear single molecular magnet with D4h symmetry, having ferromagnetic nearest neighbor and local interactions such as the Dzyaloshinsky-Moriya (DMI), axial, and azimuthal anisotropy, was performed. The evolution of the spin tetramer EPR spectra is described as a function of the spin-spin interaction parameters. The impact of spin-mixing on the splitting of spectral lines is considered for intermultiplet and intramultiplet transitions. The study yields simple relations that connect the parameters of isotropic exchange interaction, DMI, and local anisotropy to the frequency ratios of certain spectral lines.
Quantum quench for the biaxial spin system
Authors: Zvyagin A. A.
Published: November 2018

Dynamical non-equilibrium effects after a quantum quench in a quantum spin system, which permits exact analytical solution in both closed and open cases, are studied. The exact analytic results are obtained for the bi-axial paramagnet, both for the “easy axis”- and the “easy-plane”-like situations, and for the field directed along both principal axes of the system. Quantum quench of the external magnetic field produces a nonlinear response. For the closed system the average magnetic moment oscillates with time and with the final value of the external field. Such oscillations exist also for the open system, connected to the bath, in the dynamical regime. For the steady-state regime in the open case the oscillations are damped. Non-equilibrium effects yield specific hysteresis phenomena in the considered single spin system.
Influence of surface and polarization effects on electronic excitation energy transfer in colloidal solutions and films of ZnSe quantum dots
Authors: Bondar N. V. , Brodyn M. S. , Matveevskaya N. A.
Published: November 2018

Optical absorption spectra of colloidal solutions and films based on ZnSe quantum dots (QD) stabilized with thioglycerol or thioglycolic acid and precipitated on spherical nanoparticles of silicon dioxide are presented and studied. In addition to the usual quantum-size effect, two contributions to the energy of excitons in QD were found. The first (surface effect) occurs in colloidal solutions of QD stabilized by thioglycerol due to the absorption of the thiol –SH group by Zn and Se atoms. The second (polarization effect) is additional and is formed in the solid films of both colloids due to the dielectric mismatch between QD materials and the surrounding matrix. It was shown for the first time that the electronic excitation energy transfer on a spherical surface in dense ZnSe QD array occurs due to the mechanism of strong interaction (hybridization of orbitals) between neighboring QD, which is satisfactorily described by the proposed theoretical model.
Stress relaxation in ultrafine-grained copper at low homologous temperatures
Authors: Isaev N. V. , Hryhorova T. V. , Davydenko O. A. , Polishchuk S. S.
Published: November 2018

The temperature and rate sensitivity of the flow stress in ultrafine-grained (UFG) copper prepared by equal-channel angular hydroextrusion was studied. Tensile tests and stress relaxation tests were carried out in the temperature range of 77 to 295 K. It was established that, with increasing temperature, the flow stress decreases monotonously, and the activation volume reaches a maximum of ∼190b3 at a temperature of ∼(200 ± 20) K. The results of the experiment are discussed in terms of two thermally activated plastic deformation mechanisms, namely the intersection of “forest” dislocations and dynamic recovery, which are capable of significantly distorting stress relaxation kinetics in UFG copper.
Enhancement of the absorption bands in the infrared spectra of low-temperature uracil films by interference
Authors: Ivanov A. Yu. , Plokhotnichenko A. M. , Karachevtsev V. A.
Published: November 2018

An experimental method that enables significant enhancement of the bands in the IR absorption spectra of low-temperature films, using standard equipment for matrix isolation, was proposed. The effect is achieved due to the interference amplification of an electromagnetic wave using a sublayer of Ar film. IR Fourier spectra of low-temperature films of uracil (Ur) molecules were obtained in the range of 2000–500 cm–1, with a resolution of 3 cm–1. Thin Ur films with thickness of approximately 0.3 μm were grown at low temperatures on the surface of argon films of thickness of 2.3 and 1.1 μm. An enhancement in the spectral range of 1250–500 cm–1 was recorded for the first bilayer structure, and in the range of 2000–500 cm–1 for the second one. As a result of amplification in the spectrum of the low-temperature uracil film, absorption bands in the range of out-of-plane deformation vibrations of 1000–500 cm–1 were recorded for the first time. It was found that the out-of-plane fundamental NH modes of Ur groups are most sensitive to changes in the crystal structure of the film. It was shown that the absorption spectrum of the Ur film heated to room temperature differs from the spectrum of the Ur crystal obtained from the solution, which indicates a difference in their structures.
Phase diagram of the spin quantum Hall transition
Authors: Kagalovsky V. , Nemirovsky D.
Published: November 2018

We study a system which can be realized in a dirty, gapless superconductor in which time-reversal symmetry for orbital motion is broken, but spin-rotation symmetry is intact. We present a phase diagram in a phase-space of spin Hall conductance and energy of quasiparticles Δ. It exhibits a direct transition between two insulating phases with quantized Hall conductances of zero and two for the conserved quasiparticles when Δ = 0. The ener-gy of the quasiparticles acts as a relevant symmetry-breaking field at the critical point, which splits the direct transition into two conventional plateau transitions. We use updated correct values of the critical exponents to define these two critical lines as ϵ∼±Δ6/7.
Fluorine in the structure of polymers: influence on the gas separation properties
Authors: Yampolskii Yuri P. , Belov Nikolay A. , Alentiev Alexandre Yu.
Published: November 2018

Results of studies on the separation of gases and vapours using fluorine-containing polymers are integrated and analyzed. Methods for the synthesis of these polymers are considered, including direct gas-phase fluorination, plasma polymerization of fluorine-containing precursors and modification of organic polymers, as well as diverse syntheses of monomers containing C−F and C−CF3 bonds and their subsequent polymerization. Structure – property relationships for these polymers are elucidated and their actual and potential applications as membrane materials are discussed.

The bibliography includes 165 references.
Intrinsic TNFR2 signaling in T regulatory cells provides protection in CNS autoimmunity
Authors: Atretkhany Kamar-Sulu N. , Mufazalov Ilgiz A. , Dunst Josefine , Kuchmiy Anna , Gogoleva Violetta S. , Andruszewski David , Drutskaya Marina S. , Faustman Denise L. , Schwabenland Marius , Prinz Marco , Kruglov Andrey A. , Waisman Ari , Nedospasov Sergei A.
Published: November 2018

Significance

In spite of TNF involvement in the pathogenesis of multiple sclerosis (MS), systemic TNF neutralization in MS patients was not successful. One of the possible reasons is that TNF possesses both pathogenic and protective features that may be related to TNFR1 versus TNFR2 receptor engagement. This study uncovers one of such protective functions of TNF mediated by intrinsic TNFR2 signaling in Tregcells. In mice bearing humanized TNF and TNFR2 genetic loci, TNFR2 ablation restricted to Tregcells led to reduced capacity to control Th17 cell responses, exacerbated experimental autoimmune encephalomyelitis (EAE) development, and affected the maintenance of Tregcells. These findings provide support for the emerging role of TNFR2 signaling in autoimmunity, as demonstrated here in mice with conditional inactivation of TNFR2.
Removal of clock gene
Bmal1
from the retina affects retinal development and accelerates cone photoreceptor degeneration during aging
Authors: Baba Kenkichi , Piano Ilaria , Lyuboslavsky Polina , Chrenek Micah A. , Sellers Jana T. , Zhang Shuo , Gargini Claudia , He Li , Tosini Gianluca , Iuvone P. Michael
Published: November 2018

Significance

Circadian rhythms are not simply a passive consequence of cyclic fluctuations in the environment, but instead originate within the organism. Accumulating evidence indicates that disruption of circadian rhythms contributes to the development of many diseases. Here, we demonstrate that removal of the clock gene
Bmal1
from the retina has multiple effects on rod and cone pathways. In the cone pathway, the primary effect is on cone viability, an effect accentuated in aging mice. In the rod pathway, we observed that retinal
Bmal1
removal caused stunting of rod bipolar cell dendrites and thinning of the outer plexiform layer in both young and old mice. Hence, our data suggest that circadian clock dysfunction contributes to aberrant visual function during development and aging.
Genetic recovery of ErbB4 in adulthood partially restores brain functions in null mice
Authors: Wang Hongsheng , Liu Fang , Chen Wenbing , Sun Xiangdong , Cui Wanpeng , Dong Zhaoqi , Zhao Kai , Zhang Hongsheng , Li Haiwen , Xing Guanglin , Fei Erkang , Pan Bing-Xing , Li Bao-Ming , Xiong Wen-Cheng , Mei Lin
Published: November 2018

Significance

NRG1–ErbB4 signaling is implicated in GABAergic circuit assembly during development and GABAergic transmission at adulthood. However, it is unclear whether phenotypes in the adult stage in ErbB4 mutant mice result from abnormal neural development. By using two strains of mice with temporal control of ErbB4 deletion and expression, we demonstrate that ErbB4 deletion in adult mice impaired behavior and GABA release, whereas deficits due to ErbB4 null mutation during development were alleviated by restoring ErbB4 expression at the adult stage. Together, our results indicate that NRG1–ErbB4 signaling at adulthood is critical to GABAergic transmission and behavior and suggest that restoring NRG1–ErbB4 signaling at the postdevelopmental stage might benefit relevant brain disorders.
Parthenium weed: uses and abuses.
Authors: Nimal Chandrasena Nimal Chandrasena , Rao A. N.
Published: November 2018

There has been a debate about the potential role of utilization in management of parthenium weed (Parthenium hysterophorus). A large volume of published material is available on potential uses of this weed and opportunities for further exploitation. This chapter critically reviews this published information on the actual uses of the plant in different countries. It also weighs the benefits and potential problems associated with utilization of this weed in countries where existing infestations are large and threaten to spread further. It also explores the question: should utilization be considered an effective management tool in countries such as India, to manage existing infestations and prevent its further spread? It is concluded that the risks of spread and the overall negative economic, social and environmental impacts of parthenium weed may far outweigh its potential benefits, particularly in regions susceptible to new invasions. Therefore, a precautionary approach is suggested in promoting utilization of parthenium weed, not least because failure to do so would undermine the current efforts to contain its spread across many countries in Asia, South-east Asia, Africa and Australia.
History and management - Southern Asia.
Authors: Asad Shabbir Asad Shabbir , Shrestha B. B. , Ali M. H. , Adkins S. W.
Published: November 2018

In Southern Asia, parthenium weed (Parthenium hysterophorus) is now present in most countries, including India, Pakistan, Sri Lanka, Nepal, Bangladesh and Bhutan. Although there are no confirmed reports of its presence in Afghanistan or Maldives, it is highly likely that it is present in Afghanistan. This chapter discusses the history of invasion, background, spread and management of pathenium weed in Southern Asia. Parthenium weed, arguably the most important invasive plant species in Southern Asia, is well adapted to thrive in the wide-ranging habitats of this region, making management extremely difficult. One conclusion reached is that only an integrated management approach, which involves a suite of strategies (cultural, physical, biological and chemical), will be effective in managing this weed on a long-term and sustainable basis in this region. Management has to be viewed in the long term and needs to involve collaboration across states, regions and countries, as there seems to be no 'silver bullet' solution to this challenging weed.
Large‐scale, cross‐flow based isolation of highly pure and endocytosis‐competent extracellular vesicles
Authors: McNamara Ryan P. , Caro‐Vegas Carolina P. , Costantini Lindsey M. , Landis Justin T. , Griffith Jack D. , Damania Blossom A. , Dittmer Dirk P.
Published: November 2018

Isolation of extracellular vesicles (EVs) from cell culture supernatant or plasma can be accomplished in a variety of ways. Common measures to quantify relative success are: concentration of the EVs, purity from non‐EVs associated protein, size homogeneity and functionality of the final product. Here, we present an industrial‐scale workflow for isolating highly pure and functional EVs using cross‐flow based filtration coupled with high‐molecular weight Capto Core size exclusion. Through this combination, EVs loss is kept to a minimum. It outperforms other isolation procedures based on a number of biochemical and biophysical assays. Moreover, EVs isolated through this method can be further concentrated down or directly immunopurified to obtain discreet populations of EVs. From our results, we propose that cross‐flow/Capto Core isolation is a robust method of purifying highly concentrated, homogenous, and functionally active EVs from industrial‐scale input volumes with few contaminants relative to other methods.
iHam and pyHam: visualizing and processing hierarchical orthologous groups
Authors: Train Clément-Marie , Pignatelli Miguel , Altenhoff Adrian , Dessimoz Christophe
Published: November 2018

The evolutionary history of gene families can be complex due to duplications and losses. This complexity is compounded by the large number of genomes simultaneously considered in contemporary comparative genomic analyses. As provided by several orthology databases, hierarchical orthologous groups (HOGs) are sets of genes that are inferred to have descended from a common ancestral gene within a species clade. This implies that the set of HOGs defined for a particular clade correspond to the ancestral genes found in its last common ancestor. Furthermore, by keeping track of HOG composition along the species tree, it is possible to infer the emergence, duplications and losses of genes within a gene family of interest. However, the lack of tools to manipulate and analyse HOGs has made it difficult to extract, display and interpret this type of information. To address this, we introduce interactive HOG analysis method, an interactive JavaScript widget to visualize and explore gene family history encoded in HOGs and python HOG analysis method, a python library for programmatic processing of genes families. These complementary open source tools greatly ease adoption of HOGs as a scalable and interpretable concept to relate genes across multiple species.

Availability and implementation

iHam’s code is available at https://github.com/DessimozLab/iHam or can be loaded dynamically. pyHam’s code is available at https://github.com/DessimozLab/pyHam and or via the pip package ‘pyham’.
Proceedings from the 2018 Association for Chemoreception Annual Meeting Symposium: Bariatric Surgery and Its Effects on Taste and Food Selection
Authors: Spector Alan C , Kapoor Natasha , Price Ruth K , Pepino M Yanina , Livingstone M Barbara E , Le Roux Carel W
Published: November 2018

This article provides a summary of the topics discussed at the symposium titled “Bariatric Surgery and Its Effects on Taste and Food Selection,” which was held at the Fortieth Annual Meeting of the Association for Chemoreception Sciences. Bariatric surgery such as Roux-en-Y gastric bypass (RYGB) is currently one of the most effective treatments available for weight loss and Type 2 diabetes. For this reason, it is of great interest to clinicians as well as to basic scientists studying the controls of feeding and energy balance. Despite the commonly held view by clinicians that RYGB patients change their food preferences away from fats and sugars in favor of less energy dense alternatives such as vegetables, the empirical support for this claim is equivocal. It is currently thought that the taste and palatability of fats and sugars are affected by the surgery. Some key preclinical and clinical findings addressing these issues were evaluated in this symposium.
Can the financial burden of being a community health volunteer in western Kenya exacerbate poverty?
Authors: Kelly Alyssa , Mitra Sanjana , Elung’at Justus , Songok Julia , Jackson Suzanne , Christoffersen-Deb Astrid
Published: November 2018

Community health volunteers (CHVs) act as vital links between communities and health facilities, bridging the health service delivery gap common in low- and middle-income countries. In 2013, changes in funding in western Kenya left most CHVs without their individual monthly stipend. In this article, we explore how the implementation of a pooled incentive model had an impact on the lives of CHVs from two counties in western Kenya. Participation in this form of table banking was meant to allow CHVs to pool their resources together and invest in income-generating activities to offset the costs of unpaid health work. A pre-post qualitative study, consisting of focus group discussions and in-depth interviews explored CHV compensation, motivations and challenges experienced in 2013 and 2015, prior to and after the implementation of this pooled incentive model. Following withdrawal of the monthly stipend, we found that CHVs continued to take on roles and responsibilities of paid health workers, motivated by shared social identities and connections to their communities. However, replacing the stipend with a pooled-group incentive model seemingly exacerbated the financial burden already experienced by this vulnerable population. This study brings into question the sustainability and viability of a volunteer community health worker programme and highlights the need to address the financial burden associated with the CHV role in western Kenya.
Acute Pharmacokinetic Profile of Smoked and Vaporized Cannabis in Human Blood and Oral Fluid
Authors: Spindle Tory R , Cone Edward J , Schlienz Nicolas J , Mitchell John M , Bigelow George E , Flegel Ronald , Hayes Eugene , Vandrey Ryan
Published: November 2018

Currently, an unprecedented number of individuals can legally access cannabis. Vaporization is increasingly popular as a method to self-administer cannabis, partly due to perception of reduced harm compared with smoking. Few controlled laboratory studies of cannabis have used vaporization as a delivery method or evaluated the acute effects of cannabis among infrequent cannabis users. This study compared the concentrations of cannabinoids in whole blood and oral fluid after administration of smoked and vaporized cannabis in healthy adults who were infrequent users of cannabis. Seventeen healthy adults, with no past-month cannabis use, self-administered smoked or vaporized cannabis containing Δ9-tetrahydrocannabinol (THC) doses of 0, 10 and 25 mg in six double-blind outpatient sessions. Whole blood and oral fluid specimens were obtained at baseline and for 8 h after cannabis administration. Cannabinoid concentrations were assessed with enzyme-linked immunosorbent assay (ELISA) and liquid chromatography–tandem mass spectrometry (LC–MS-MS) methods. Sensitivity, specificity and agreement between ELISA and LC–MS-MS results were assessed. Subjective, cognitive performance and cardiovascular effects were assessed. The highest concentrations of cannabinoids in both whole blood and oral fluid were typically observed at the first time point (+10 min) after drug administration. In blood, THC, 11-OH-THC, THCCOOH and THCCOOH-glucuronide concentrations were dose-dependent for both methods of administration, but higher following vaporization compared with smoking. THC was detected longer in oral fluid compared to blood and THCCOOH detection in oral fluid was rare and highly erratic. For whole blood, greater detection sensitivity for ELISA testing was observed in vaporized conditions. Conversely, for oral fluid, greater sensitivity was observed in smoked sessions. Blood and/or oral fluid cannabinoid concentrations were weakly to moderately correlated with pharmacodynamic outcomes. Cannabis pharmacokinetics vary by method of inhalation and biological matrix being tested. Vaporization appears to be a more efficient method of delivery compared with smoking.
Evaluation of App-Embedded Disease Scales for Aiding Visual Severity Estimation of Cercospora Leaf Spot of Table Beet
Authors: Del Ponte Emerson M. , Nelson Scot C. , Pethybridge Sarah J.
Published: November 2018

Two diagrammatic ordinal scales are available in the Estimate app (2017 version) for Cercospora leaf spot (CLS) severity on table beet: 10% linear (linear-based diagrammatic scale [LIN]) and logarithmic based (Horsfall–Barratt [HB]). These allow for estimating severity data of four types depending on the system used. A group of 30 raters assigned percentage severity on 30 photographs of diseased table beet leaves during five rounds first without an aid and then using each of the four rating systems in Estimate. In two, the perceived ordinal score of the HB or LIN scale was assigned where severity of the subject fit best. HB2 and LIN2 involved a second choice of unitary severity within the perceived score interval. There was large variation in unaided ability of raters to estimate severity: 13% were accurate (Lin’s concordance correlation [LCC] > 0.9), 23% were inaccurate (LCC < 0.7), and the remaining had moderate accuracy. Larger disparities between assigned and actual ordinal scores (mostly overestimates) occurred using the LIN compared with the HB. The LIN2 produced the most accurate estimates (Lin’s concordance correlation coefficient, ρc = 0.96; generalized bias parameter, Cb = 0.99; Pearson’s correlation coefficient r = 0.95) and the greatest interrater reliability (overall concordance correlation coefficient and intraclass correlation coefficient > 0.93). The two-step process using the 10% linear scale is recommended for severity estimates of CLS in table beet.
The role of surfactant protein-A in sinusitis
Authors: Chang Eugene H.
Published: November 2018

Purpose of review

Surfactant protein-A (SP-A) is a collectin protein expressed in airway epithelia that is critical in the modulation of both innate and adaptive immunity against inhaled pathogens. In this review, we highlight associations of altered SP-A function in asthma and chronic rhinosinusitis, and its potential role as a targeted therapy for sinusitis.

Recent findings

SP-A has been shown to bind and opsonize inhaled pathogens, thereby clearing bacteria through phagocytosis. We have recently identified that SP-A levels are increased in response to Pseudomonas aeruginosa, a common bacterial pathogen in chronic rhinosinusitis. Moreover, SP-A has also been shown to modulate epithelial inflammatory mediators and play a role in eosinophil-mediated airway disease. The development of a transgenic murine model expressing human genetic variants of SP-A2 have suggested that the human surfactant protein-A2 223K variant significantly increases eosinophil degranulation, suggesting a genotype-phenotype correlation in human airway disease.

SP-A is important in both the innate and adaptive host defense mechanisms in the upper and lower airways. Although research in this field in sinusitis is nascent, initial work suggests that aberrant SP-A regulation may be one etiologic factor in the development of bacterial and eosinophilic-associated sinusitis.
Preventing the development of asthma: stopping the allergic march
Authors: Maciag Michelle C. , Phipatanakul Wanda
Published: November 2018

Purpose of review

To describe important precipitants of asthma and allergic disease, to highlight the links between these triggers and modifications within the immune system, and to examine innovative research regarding asthma prevention with focus on attenuating the atopic march.

Recent findings

Allergen avoidance, allergen immunotherapy, IgE antagonists, prevention and treatment of respiratory infections, as well as management of gastrointestinal and respiratory dysbiosis have been considered as strategies in asthma prevention. Antenatal vitamin D supplementation in expectant mothers and aggressive control of atopic dermatitis to prevent the development of other allergic conditions were carefully studied as well.

Asthma is a major cause of morbidity and lost productivity. Despite the tremendous burden of this disease, the scientific community is still struggling to find an effective means of prevention. The contribution of genetics to the development of atopy cannot be altered, but environmental changes as well as pharmacotherapy have been studied as modifiable risk factors. Many trials to date have been effective only for subjects with certain characteristics. This is likely because asthma is a heterogenous condition, with a variety of triggers and clinical phenotypes. Thus far, a universally effective prevention strategy has eluded us. However, if an intervention can be found to prevent asthma and the allergic march, it will greatly improve quality of life for millions of sufferers and decrease healthcare expenditures.
Obesity and adiposity indicators in asthma and allergic rhinitis in children
Authors: Tajima Hanako , Pawankar Ruby
Published: November 2018

Purpose of review

The prevalence of obesity and allergic diseases, such as asthma and allergic rhinitis, is increasing worldwide not only in adults, but also in children. Experimental and clinical studies have demonstrated the effect of obesity not only on asthma, but also on other allergic diseases.

Recent findings

Allergic diseases, such as asthma and allergic rhinitis, are common chronic inflammatory diseases of the airways. Obesity is an increasingly common pediatric disease and is a risk factor for the development of asthma in that obese patients with asthma tend to have more severe asthma that does not respond well to standard asthma therapy. On the contrary, children with asthma maybe at a high risk of obesity, suggesting that the relationship of asthma and obesity seems to be interrelated. The role of obesity on the development of allergic rhinitis is not well defined, whereas allergic rhinitis may have an impact on obesity.

Childhood obesity is often considered to be less serious than obesity in adults because of the greater risk of complications in obese adults. In this review, we discuss the allergic confounders of obesity and the impact of allergic diseases on obesity. Proper control of the BMI within the normal range in children with allergic diseases is important.
Pharmacologic Approach to Management of Clostridium difficile Infection
Authors: Martin Lukas T. , Vincent Shelbi , Gillian Sarah , Moore Katherine , Ratermann Deanna , Droege Christopher A.
Published: November 2018

Clostridium difficile is a gram-positive, anaerobic, spore-forming bacterium that is the leading cause of nosocomial infections in hospitals in the United States. Critically ill patients are at high risk for C. difficile infection (CDI) and face potentially detrimental effects, including prolonged hospitalization, risk of recurrent disease, complicated surgery, and death. CDI requires a multidisciplinary approach to decrease hospital transmission and improve treatment outcomes. This article briefly reviews the current literature and guideline recommendations for treatment and prevention of CDI, with a focus on antibiotic treatment considerations including dosing, routes of administration, efficacy data, adverse effects, and monitoring parameters.
Spurious Laboratory Values in Patients With Leukocytosis
Authors: Malek Tony , Chen Leon
Published: November 2018

Physiological derangements such as hypoxemia and hyperkalemia are medical emergencies that warrant prompt interventions to prevent further patient clinical deterioration. However, in patients with myeloproliferative diseases or malignancies that result in extreme leukocytosis, hypoxemia and hyperkalemia demonstrated in laboratory results could be deceiving due to in vitro reactions and may not reflect actual patient condition. Clinicians have to be familiar with these phenomena so as to not cause harm by treating these spurious laboratory values.
Horseshoe, Cockpit, and Dragonfly
Authors: Hamilton D. Kirk
Published: November 2018

An exploratory, qualitative study conducted on 6 units in 4 hospitals featured field observations of 20 experienced nurses during complete 12-hour day and night shifts, followed by semistructured participant interviews. All patient rooms featured conventional headwall-type life support systems in which the head of the bed is against the wall where multiple electrical, gas, and communication utilities are located. Critical care nurses displayed repetitive movement patterns around the patient and the bed. Movement patterns observed varied according to room size, availability of supplies, and positions of fixed and/or mobile equipment, along with types and locations of documentation computers.
Symptom Management and Hospital Readmission in Heart Failure Patients
Authors: Sousa Joana Pereira , Santos Miguel
Published: November 2018

This article reports a study aimed at identifying the factors that result in hospital readmissions for patients with heart failure. The high rates of readmission are often due to a lack of knowledge about symptoms and signs of disease progression, and these Portuguese nurses believed that readmissions could be decreased through disease management programs in which patients assumed a more active role in self-care. A study was designed to identify broad categories of problems that lead Portuguese patients with heart failure to be readmitted to hospital. Semistructured interviews were conducted, recorded, and submitted for content analysis, revealing 3 main categories for targeting: health management, behavioral management, and psychological support. This study revealed that patients with heart failure seem to struggle with management of multiple treatment regimens during the long course of their chronic illness. Based on these interviews, authors conclude that a disease management program be tailored expressly for the Portuguese culture and their lifestyle.
Effect of Interventional Educational Programs on Intensive Care Nurses' Perception, Knowledge, Attitude, and Practice About Physical Restraints
Authors: Ahmadi Mohamad , Bagheri-Saweh Mohammad Iraj , Nouri Bijan , Mohamadamini Omid , Valiee Sina
Published: November 2018

The article reports results of an educational program designed to modify negative attitudes of intensive care nurses regarding the use of physical restraints. Findings revealed that increased knowledge about appropriate utilization of various types of restraints positively impacted perceptions, attitudes, and patient care practices. Authors also explore restraint use in several countries and identify variations in use of restraining methods.
Quantification of Thiopurine Nucleotides in Erythrocytes and Clinical Application to Pediatric Acute Lymphoblastic Leukemia
Authors: Moon Soo Young , Lim Ji-Hyun , Kim Eun-Hee , Nam Youngwon , Yu Kyung-Sang , Hong Kyung Taek , Choi Jung Yoon , Hong Che Ry , Kim Hyery , Kang Hyoung Jin , Shin Hee Young , Lee Kyunghoon , Song Junghan , Lee Soo-Youn , Song Sang Hoon
Published: November 2018

Background:

Concentrations of 6-thioguanine (6TG) nucleotides and 6-methylmercaptopurine (6MMP) nucleotides in RBCs were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS). This assay was validated for clinical use and was applied to blood samples from patients taking mercaptopurine (6MP).

Methods:

RBCs were hemolyzed and deproteinized using perchloric acid, followed by heating for the hydrolysis of nucleotides, and the resultant base was measured using LC-MS/MS. Precision, recovery, linearity, matrix effect, and limit of quantification was validated for clinical application. Our results were compared with another institution's established LC-MS/MS assay. We measured the concentrations of 6TG and 6MMP in RBCs of pediatric patients with acute lymphoblastic leukemia (ALL), and the clinical impact of those metabolites was investigated.

Results:

The imprecision coefficient of variations of 6TG and 6MMP were 5.7%–8.1%, and the bias was within 5%. Lower limits of quantification were set at 54 ng/mL for 6TG and 1036 ng/mL for 6MMP. Correlation coefficients for 6TG and 6MMP were 0.997 and 1.0 in a comparison study. For clinical proof-of-concept, 74 blood samples were collected from 37 pediatric ALL patients receiving maintenance therapy. Concentration of 6TG ranged from 16.1 to 880 pmol/8 × 108 RBCs and that of 6MMP from 55 to 20,937 pmol/8 × 108 RBCs. The 6MP metabolites were not correlated with WBC or absolute neutrophil count. On the other hand, the higher 6MMP level was associated with elevated alanine aminotransferase and aspartate aminotransferase.

Conclusions:

In this study, an assay for the quantification of 6TG and 6MMP in RBCs was established and applied to pediatric ALL patients. Interindividual variability in 6MP metabolite concentrations was considerable and associated with elevation of liver enzymes, which may be useful in the clinical monitoring of 6MP maintenance therapy in pediatric ALL patients.
Concentration–Effect Relationships of Psychoactive Drugs and the Problem to Calculate Therapeutic Reference Ranges
Authors: Hiemke Christoph
Published: November 2018

Background:

Despite the obvious potential of Therapeutic Drug Monitoring (TDM) as a tool to optimize psychopharmacotherapy, especially treatment with mood-stabilizing, antidepressant and antipsychotic drugs, acceptance of TDM as a routine tool is still limited. A serious scientific argument against the regular use of TDM is the lack of evidence for a concentration-dependent clinical effect. The aim of this review was to highlight methodological problems leading to poor or even negative concentration–effect relationships and to show how therapeutically effective concentrations of psychoactive drugs can be determined using routine TDM databases.

Methods:

Reports on concentration–effect relationships of psychoactive drugs were analyzed with regard to applied methods. From routine TDM databases of patients who had been treated with antidepressant or antipsychotic drugs and whose improvement was measured by the clinical global impressions scale, mean and median drug concentrations were calculated and compared with reference ranges recommended by TDM guidelines.

Results:

Few fixed-dose studies with adequate design and data analysis demonstrated a correlation between drug concentration and clinical effect for psychoactive drugs. Most studies, however, mostly retrospective analyses of TDM databases, failed to find significant concentration–effect relationships because of flexible dosing. They were not suitable for the determination of therapeutically effective drug concentrations. Using TDM databases of antidepressant and antipsychotic drug concentrations in blood of patients who were categorized as responders by the clinical global impressions score, the interquartile ranges of drug concentrations (25th–75th percent range) can be shown to be very close to the therapeutic reference ranges recommended in guidelines for TDM in psychiatry.

Conclusions:

This review provides a discussion on why simple correlation analyses of psychoactive drug concentrations in blood and clinical effects are obsolete for flexible-dose studies or TDM databases. TDM databases, however, can and should be used to calculate drug concentrations in blood of patients who had responded to the drugs. Interquartile ranges can be regarded and used as preliminary therapeutic reference ranges.
Molecular characterization of endometrial cancer and therapeutic implications
Authors: Chang Zenas , Talukdar Shobhana , Mullany Sally A. , Winterhoff Boris
Published: November 2018

Purpose of review

The present article reviews genomic subtyping of endometrial carcinoma and new molecular markers with therapeutic and prognostic implications.

Recent findings

Endometrial cancer has historically been classified through histology into endometrioid (type 1) and nonendometrioid (type II, mainly serous) subtypes. Molecular classification through genomic analysis now allows for a major advance in characterization; four distinct subgroups have been identified: polymerase ε (POLE) ultramutated, microsatellite unstable, copy number low/microsatellite stable, and copy number high/'serous-like’. These subtypes have prognostic implications and may aid in the identification of early-stage patients who are at high risk for recurrence. Through analysis of surrogate markers (POLE, MSI, and p53) and other validated molecular alterations (L1CAM), it may be possible to obtain an integrated molecular risk profile. Ongoing studies are utilizing this risk profile in order to identify patients who may benefit from additional treatment for early-stage disease.

Molecular characterization of endometrial cancer into subgroups has prognostic and therapeutic implications. Further development of an integrated molecular risk profile may identify patients who could benefit from additional treatment because of a higher risk of recurrence.
Single-cell sequencing in ovarian cancer: a new frontier in precision medicine
Authors: Winterhoff Boris , Talukdar Shobhana , Chang Zenas , Wang Jinhua , Starr Timothy K.
Published: November 2018

Purpose of review

This article discusses the advances, applications and challenges of using single-cell RNA sequencing data in guiding treatment decisions for ovarian cancer.

Recent findings

Genetic heterogeneity is a hallmark of ovarian cancer biology and underlies treatment resistance. Defining the different cell types present within a single ovarian cancer is difficult, but could ultimately lead to improvements in diagnosis and treatment. Next-generation sequencing technologies have rapidly increased our understanding of the molecular landscape of epithelial ovarian cancers, but the majority of these studies are conducted on bulk samples, resulting in data that represents an ‘average’ of all cells present. Single-cell sequencing provides a means to characterize heterogeneity with a tumor tissue in ovarian cancer patients and opens up opportunity to determine key molecular properties that influence clinical outcomes, including prognosis and treatment response.

Single-cell sequencing provides a powerful tool in improving our understanding of tumor cell heterogeneity for the purpose of informing personalized cancer treatment.
Growth, pubertal development, and skeletal health in boys with Duchenne Muscular Dystrophy
Authors: Ward Leanne M. , Weber David R.
Published: November 2018

Purpose of review

Glucocorticoid therapy is currently the most widely used treatment for Duchenne muscular dystrophy (DMD), having consistently shown to prolong ambulation by 2 years, reduce the frequency of scoliosis, and improve cardiorespiratory function. Among the most frequent side effects of glucocorticoids are fractures due to osteoporosis, linear growth retardation or arrest, and pubertal delay, the subjects of this review.

Recent findings

The diagnosis of osteoporosis has shifted in recent years away from a bone mineral density-centric to a fracture-focused approach, with particular emphasis on early vertebral fracture identification (one of the key triggers for osteoporosis intervention). Delayed puberty should be addressed in an age-appropriate manner, with numerous options available for sex steroid replacement. Growth impairment, however, is a more challenging complication of glucocorticoid-treated DMD, one that is most likely best addressed through growth-sparing therapies that target the dystrophinopathy.

With glucocorticoid prescription an increasingly prevalent component of DMD care, early attention to management of osteoporosis and delayed puberty are important components of multidisciplinary and anticipatory care. The treatment of short stature remains controversial, with no accepted therapy currently available to over-ride the toxic effects of glucocorticoids on the growth axis.
Ethical issues with early genitoplasty in children with disorders of sex development
Authors: Harris Rebecca M. , Chan Yee-Ming
Published: November 2018

Purpose of review

Genitoplasty in children with disorders of sex development (DSD) is an ethically complex issue. From a surgical perspective, genitoplasty in early childhood is preferred because it is felt to be associated with improved tissue healing, decreased risk of complications, and reduced psychological impact of genital surgery. However, advocacy groups and recent ethics literature have argued for deferring genitoplasty until a child reaches decisional maturity. This article reviews these arguments using an ethical framework and discusses the application and challenges of recent disorders of sex development research.

Recent findings

Recent ethics literature and advocacy groups have argued for deferring genitoplasty until a child reaches decisional maturity. As a counterpoint, urological societies have published arguments supporting the practice of early genitoplasty. Data from DSD research lends some guidance but also has a wide range of outcomes, which makes generalizability difficult. A retrospective, multicenter study of 21 individuals with congenital adrenal hyperplasia who underwent feminizing surgery showed no difference between cases and controls in social functioning, parent–child relationships, or sexual fulfillment. Ninety percent of patients thought genitoplasty should occur within the first year of life. In a study of 52 patients with 46,XY and 46,XX DSDs who underwent masculinizing genitoplasty, 57% thought their physical appearance was ‘fair’ or ‘poor,’ and problems with sexual function, urinary incontinence, and short penile length were common.

Early genitoplasty in children with DSDs is ethically complex, and discordant results in DSD research makes generalizability difficult. There is unlikely to be a universal solution to the issue of early genitoplasty in children with DSDs; families must be supported while they weigh both parental decision-making and the objective of ensuring an open future for their child.
Undernutrition and growth in the developing world
Authors: Nijjar Jasreena K. , Stafford Diane
Published: November 2018

Purpose of review

Despite targeted interventions, an estimated 150.8 million children under 5 years globally are still stunted, of which more than half live in Asia and more than one-third live in Africa. This review summarizes our current knowledge regarding how longitudinal bone growth is regulated by nutritional intake in the developing world. Dietary macronutrients and micronutrients necessary for growth are also briefly reviewed.

Recent findings

Recent advances include investigations of nutritionally sensitive regulators of growth as well as prospective evaluations of the role of specific dietary components on growth in order to better assess their impact.

Further investigation is required to understand how nutrition impacts growth, the mechanisms underlying stunting and to optimize therapeutic strategies for children who are at risk for growth attenuation or are stunted in low and middle-income countries (LMICs).
Acetarsol in the management of mesalazine-refractory ulcerative proctitis: a tertiary-level care experience
Authors: Argyriou Konstantinos , Samuel Sunil , Moran Gordon W.
Published: November 2018

Background

Mesalazine-refractory ulcerative proctitis is common, with a significant proportion of the patients requiring escalation to immunomodulators or biological therapy. Three small preliminary cohort studies suggested good clinical efficacy for the organic arsenic derivative acetarsol in the management of proctitis. Our aim was to describe our experience on the use of acetarsol in proctitis and to review all existing evidence on its safety and efficacy.

Patients and methods

We retrospectively reviewed clinical records of all ulcerative colitis patients exposed to acetarsol at Nottingham University Hospitals since 2012. Clinical response was determined basing on physicians’ global assessments and patients’ improvement over the baseline (reduction in stool frequency and rectal bleeding). Clinical remission was defined as total resolution of symptoms including bleeding cessation. Serum arsenic, C-reactive protein and faecal calprotectin levels reviewed when available. Nonparametric analysis performed.

Results

Twenty-eight (16 males) patients with median (range) age 39 (35) and 9 (19) years disease duration received acetarsol suppositories for proctitis. All had failed mesalazine or corticosteroid topical therapy, with 50% having additionally failed immunomodulators. Median treatment duration was 70 (64) days. 16/28 were prescribed acetarsol more than once. 67.9% achieved clinical response and 46.4% clinical remission. 32.1% required treatment escalation to steroids, thiopurines or antitumour necrosis factor agents. 6/28 patients stopped acetarsol due to side effects.

Conclusion

Acetarsol could be an effective and safe option in the management of refractory proctitis. A definitive trial with long-term safety follow-up is required to investigate the efficacy and safety of this promising drug.