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Objective: The stratification of neuroblastoma (NBL) prognosis remains difficult. RNA-based signatures might be able to predict prognosis, but independent cross-platform validation is still rare.Methods: RNA-Seq-based profiles from NBL patients were acquired and then analyzed. The RNA-Seq prognostic index (RPI) and the clinically adjusted RPI (RCPI) were successively established in the training cohort (TARGET-NBL) and then verified in the validation cohort (GSE62564). Survival prediction was assessed using a time-dependent receiver operating characteristic (ROC) curve and area under the ROC curve (AUC). Functional enrichment analysis of the genes was conducted using bioinformatics methods.Results: In the training cohort, 10 gene pairs were eventually integrated into the RPI. In both cohorts, the high-risk group had poor overall survival (OS) (P < 0.001 and P < 0.001, respectively) and favorable event-free survival (EFS) (P = 0.00032 and P = 0.06, respectively). ROC curve analysis also showed that the RPI predicted OS (60 month AUC values of 0.718 and 0.593, respectively) and EFS (60 month AUC values of 0.627 and 0.852, respectively) well in both the training and validation cohorts. Clinicopathological indicators associated with prognosis in the univariate and multivariate regression analyses were identified and added to the RPI to form the RCPI. The RCPI was also used to divide populations into different risk groups, and the high-risk group had poor OS (P < 0.001 and P < 0.001, respectively) and EFS (P < 0.05 and P < 0.05, respectively). Finally, the RCPI had higher accuracy than the RPI for the prediction of OS (60 month AUC values of 0.730 and 0.852, respectively) and EFS (60 month AUC values of 0.663 and 0.763, respectively) in both the training and validation cohorts. Moreover, these differentially expressed genes may be involved in certain NBL-related events.Conclusions: The RCPI could reliably categorize NBL patients based on different risks of death.

Background Cultivars of bahiagrass (Paspalum notatum Flüggé) are widely used for pasture in the Southeastern USA. Soil microbial communities are unexplored in bahiagrass and they may be cultivar-dependent, as previously proven for other grass species. Understanding the influence of cultivar selection on soil microbial communities is crucial as microbiome taxa have repeatedly been shown to be directly linked to plant performance. Objectives This study aimed to determine whether different bahiagrass cultivars interactively influence soil bacterial and fungal communities. Methods Six bahiagrass cultivars (‘Argentine’, ‘Pensacola’, ‘Sand Mountain’, ‘Tifton 9’, ‘TifQuik’, and ‘UF-Riata’) were grown in a randomized complete block design with four replicate plots of 4.6 × 1.8 m per cultivar in a Rhodic Kandiudults soil in Northwest Florida, USA. Three soil subsamples per replicate plot were randomly collected. Soil DNA was extracted and bacterial 16S ribosomal RNA and fungal ribosomal internal transcribed spacer 1 genes were amplified and sequenced with one Illumina Miseq Nano. Results The soil bacterial and fungal community across bahiagrass cultivars showed similarities with communities recovered from other grassland ecosystems. Few differences in community composition and diversity of soil bacteria among cultivars were detected; none were detected for soil fungi. The relative abundance of sequences assigned to nitrite-oxidizing Nitrospira was greater under ‘Sand Mountain’ than ‘UF-Riata’. Indicator species analysis revealed that several bacterial and fungal indicators associated with either a single cultivar or a combination of cultivars are likely to be plant pathogens or antagonists. Conclusions Our results suggest a low impact of plant cultivar choice on the soil bacterial community composition, whereas the soil fungal community was unaffected. Shifts in the relative abundance of Nitrospira members in response to cultivar choice may have implications for soil N dynamics. The cultivars associated with presumptive plant pathogens or antagonists indicates that the ability of bahiagrass to control plant pathogens may be cultivar-dependent, however, physiological studies on plant-microbe interactions are required to confirm this presumption. We therefore suggest that future studies should explore the potential of different bahiagrass cultivars on plant pathogen control, particularly in sod-based crop rotation.

High-throughput amplicon sequencing that primarily targets the 16S ribosomal DNA (rDNA) (for bacteria and archaea) and the Internal Transcribed Spacer rDNA (for fungi) have facilitated microbial community discovery across diverse environments. A three-step PCR that utilizes flexible primer choices to construct the library for Illumina amplicon sequencing has been applied to several studies in forest and agricultural systems. The three-step PCR protocol, while producing high-quality reads, often yields a large number (up to 46%) of reads that are unable to be assigned to a specific sample according to its barcode. Here, we improve this technique through an optimized two-step PCR protocol. We tested and compared the improved two-step PCR meta-barcoding protocol against the three-step PCR protocol using four different primer pairs (fungal ITS: ITS1F-ITS2 and ITS1F-ITS4, and bacterial 16S: 515F-806R and 341F-806R). We demonstrate that the sequence quantity and recovery rate were significantly improved with the two-step PCR approach (fourfold more read counts per sample; determined reads ≈90% per run) while retaining high read quality (Q30 > 80%). Given that synthetic barcodes are incorporated independently from any specific primers, this two-step PCR protocol can be broadly adapted to different genomic regions and organisms of scientific interest.

The nanostructuring of a sensing membrane is performed through colloidal nanosphere lithography (NSL) techniques with a tiny polystyrene nanobead template 100 nm in size. The solvent ratio adjustment has been proven to be effective in assisting the monolayer deposition of small templating particles with minimal defects. Two distinct structures, namely, a billowy gold nanostructure (BGN) where the nanobead template is left unetched and a gold nanoframe array (GNA) with a regular ring-like structure after template removal, are used for the extended-gate field-effect transistor (EGFET) electrodes. The GNA structure generates an electroactive surface area significantly (~20%) larger than its geometrical area as well as a greater surface roughness than the BGN. When integrated with the portable constant voltage–constant current (CVCC) FET circuitry for pH screening to determine the optimized measurement conditions for H2O2 sensing, the GNA sensing membrane also shows more improved Nernstian sensitivity at ~50 mV/pH than the BGN electrode. The more optimized sensitivity is then proven using the GNA in the detection of H2O2, the most common representative reactive oxygen species (ROS) involved in the environment, food, and neurodegenerative diseases, such as Parkinson´s and Alzheimer´s diseases. The GNA electrode has a sensitivity of 70.42 mV/log µM [H2O2] and a limit of detection (LoD) of 1.183 µM H2O2. The integrated ion sensing system employing unique, highly ordered gold array gate electrodes and a portable CVCC circuit system has shown a stable real-time output voltage signal, representing an alternative to bulky conventional FET devices for potential on-site H2O2 detection.

This in vitro study evaluates the performance of a disposable vibrating-mesh nebulizer when used for 28 days. A lung model was used to simulate the breathing pattern of an adult with chronic obstructive pulmonary disease. The vibrating-mesh nebulizer was used for three treatments/day over 28 days without cleaning after each test. Results showed that the inhaled drug dose was similar during four weeks of use (p = 0.157), with 16.73 ± 4.46% at baseline and 15.29 ± 2.45%, 16.21 ± 2.21%, 17.56 ± 1.98%, and 17.13 ± 1.81%, after the first, second, third, and fourth weeks, respectively. The particle size distribution, residual drug volume, and nebulization time remained similar across four weeks of use (p = 0.110, p = 0.763, and p = 0.573, respectively). Mesh was inspected using optical microscopy and showed that approximately 50% of mesh pores were obscured after 84 runs, and light penetration through the aperture plate was significantly reduced after the 21st use (p < 0.001) with no correlation to nebulizer performance. We conclude that the vibrating-mesh nebulizer delivered doses of salbutamol solution effectively over four weeks without cleaning after each use even though the patency and clarity of the aperture plate were reduced by the first week of use.

Recent studies have shown that M. elongata (M. elongata) isolated from Populus field sites has a dual endophyte–saprotroph lifestyle and is able to promote the growth of Populus. However, little is known about the host fidelity of M. elongata and whether M. elongata strains differ from one another in their ability to promote plant growth. Here, we compared the impacts of three Populus-associated M. elongata isolates (PMI 77, PMI 93, and PMI 624) on the growth of seven different crop species by measuring plant height, plant dry biomass, and leaf area. M. elongata isolates PMI 624 and PMI 93 increased the plant height, leaf area, and plant dry weight of Citrullus lanatus, Zea mays, Solanum lycopersicum, and Cucurbita to a much greater degree than PMI 77 (33.9% to 14.1%). No significant impacts were observed for any isolate on the growth of Abelmoschus esculentus or Glycine max. On the contrary, Glycine max significantly decreased in height by 30.6% after the inoculation of M. elongata PMI 77. In conclusion, this study demonstrates that M. elongata generally promoted metrics of the plant performance among a diverse set of importantly non-leguminous crop species. Future research on understanding the molecular mechanisms that underlie strain and host variability is warranted.

As our understanding of soil biology deepens, there is a growing demand for investigations addressing microbial processes in the earth beneath the topsoil layer, called subsoil. High clay content in subsoils often hinders the recovery of sufficient quantities of DNA as clay particles bind nucleic acids. Here, an efficient and reproducible DNA extraction method for 200 mg dried soil based on sodium dodecyl sulfate (SDS) lysis in the presence of phosphate buffer has been developed. The extraction protocol was optimized by quantifying bacterial 16S and fungal 18S rRNA genes amplified from extracts obtained by different combinations of lysis methods and phosphate buffer washes. The combination of one minute of bead beating, followed by ten min incubation at 65°C in the presence of 1 M phosphate buffer with 0.5% SDS, was found to produce the best results. The optimized protocol was compared with a commonly used cetyltrimethylammonium bromide (CTAB) method, using Phaeozem soil collected from 60 cm depth at a conventional agricultural field and validated on five subsoils. The reproducibility and robustness of the protocol was corroborated by an interlaboratory comparison. The DNA extraction protocol offers a reproducible and cost-effective tool for DNA-based studies of subsoil biology.

We aimed to quantify Soft Mist Inhalers (SMI) delivery to spontaneous breathing model and compare with different adapters via endotracheal tube during mechanical ventilation or by manual resuscitation. A tiotropium SMI was used with a commercial in-line adapter and a T-adapter placed between the Y-adapter and the inspiratory limb of the ventilator circuit during mechanical ventilation. The SMI was actuated at the beginning of inspiration and expiration. In separate experiments, a manual resuscitator with T-adapter was attached to endotracheal tube, collecting filter, and a passive test lung. Drug was eluted from collecting filters with salt-based solvent and analyzed using high-performance liquid chromatography. Results showed the percent of SMI label dose inhaled was 3-fold higher with the commercial in-line adapter with actuation during expiration than when synchronized with inspiration. SMI with T-adapter delivery via ventilator was similar to inhalation (1.20%) or exhalation (1.02%), and both had lower delivery dose than with manual resuscitator (2.80%; p = 0.01). The inhaled dose via endotracheal tube was much lower than inhaled dose with spontaneous breathing (22.08%). In conclusion, the inhaled dose with the commercial adapter was higher with SMI actuated during expiration, but still far less than reported spontaneous inhaled dose.

[This corrects the article DOI: 10.1371/journal.pgen.1006348.].

Light can affect the yields of alkaloid and essential oil in the synthesis of secondary metabolites directly or indirectly through plant growth. Despite Mahonia breviracema being an endemic medicinal species in China, research on the influence of light on production of alkaloid and essential oil is scarce. Thus, this research evaluated the influence of various lighting conditions on alkaloid yields and the composition and yields of the essential oils of M. breviracema. The results revealed significant differences in alkaloid yields, oil yields and chemical characteristics of M. breviracema grown in four different light intensities from 10 to 100% full sun shine. The total amount of alkaloids in plants under I30 and I50 was higher than that under I10 and I100 due to the higher biomass of plants. Oil yield of M. breviracema leaf increased linearly with the increase of light incidence. Plants grown under I10 had less plastoglobuli, which coincided with the lowest oil yield (1.91 g kg-1). The plastoglobuli in chloroplasts increased when the irradiance levels increased, resulting in the highest oil yields under I100 (4.53 g kg-1). The principal components in the leaves of M. breviracema were hexadecanoic acid (10.54-72.19%) and α-ionone (1.25-42.39%). The highest hexadecanoic acid content was obtained under I50, followed by I30, and the highest α-ionone content was obtained under I100. Therefore, it is necessary to control the light environment to obtain raw materials with high quality.

Oyster mushrooms are commonly found on hardwoods throughout the north temperate zone; they are edible and have many nutritious qualities. This 5-page document describes how you can grow your own oyster mushrooms at home. Written by Chih-Ming Hsu, Khalid Hameed, Van T. Cotter, and Hui-Ling Liao and published by the UF/IFAS Department of Soil and Water Sciences, January 2018. http://edis.ifas.ufl.edu/ss662

This 6-page publication details the cultivation of oyster mushrooms from mother culture isolation to spawn preparation. This protocol can be used by both homeowners and commercial cultivators. Written by Chih-Ming Hsu, Khalid Hameed, Van T. Cotter, and Hui-Ling Liao and published by the UF/IFAS Department of Soil and Water Sciences, January 2018. http://edis.ifas.ufl.edu/ss663

Few studies have investigated the difference in bacterial contamination between conventional reused ventilator systems and disposable closed ventilator-suction systems. The aim of this study was to investigate the bacterial contamination rates of the reused and disposable ventilator systems, and the association between system disconnection and bacterial contamination of ventilator systems.The enrolled intubated and mechanically ventilated patients used a conventional reused ventilator system and a disposable closed ventilator-suction system, respectively, for a week; specimens were then collected from the ventilator circuit systems to evaluate human and environmental bacterial contamination. The sputum specimens from patients were also analyzed in this study.The detection rate of bacteria in the conventional reused ventilator system was substantially higher than that in the disposable ventilator system. The inspiratory and expiratory limbs of the disposable closed ventilator-suction system had higher bacterial concentrations than the conventional reused ventilator system. The bacterial concentration in the heated humidifier of the reused ventilator system was significantly higher than that in the disposable ventilator system. Positive associations existed among the bacterial concentrations at different locations in the reused and disposable ventilator systems, respectively. The predominant bacteria identified in the reused and disposable ventilator systems included Acinetobacter spp., Bacillus cereus, Elizabethkingia spp., Pseudomonas spp., and Stenotrophomonas (Xan) maltophilia.Both the reused and disposable ventilator systems had high bacterial contamination rates after one week of use. Disconnection of the ventilator systems should be avoided during system operation to decrease the risks of environmental pollution and human exposure, especially for the disposable ventilator system.ClinicalTrials.gov PRS / NCT03359148.

Noninvasive positive pressure ventilation has been regarded as a strategy for improving exercise performance. Whether an increase in the ventilatory support level improves exercise performance in patients who have received invasive ventilation is unknown. The purpose of this study is to examine the effects of an additional level of pressure support (PS) ventilation on exercise tolerance in patients undergoing prolonged mechanical ventilation (PMV). Methods: This study examined 15 patients who were undergoing PMV. All patients performed an upper-arm exercise test at three PS levels: the baseline PS level (PS), a level 2 cmH2O higher than the baseline level (PS+2), and a level 4 cmH2O higher than the baseline level (PS+4). The physiological response, reasons for discontinuing the exercise test, and exercise duration were recorded and analyzed. Results: The tidal volume increased significantly from 271.7 ± 54.7 mL to 398.3 ± 88.7 mL at the PS+4 level (p = 0.01). Significant differences in exercise duration were observed at different PS levels. The exercise duration was significantly longer at the PS+4 level than at the PS and PS+2 levels (146.3 ± 139.9 seconds vs. 108.5 ± 85.9 seconds vs. 72.8 ± 43.9 seconds, p = 0.038) as their corresponding order. There were significant relationships between resting respiratory rate and exercise duration at the PS (r = −0.639, p = 0.034) and PS+2 levels (r = −0.668, p = 0.025). Conclusion: In patients undergoing PMV, an additional PS level of up to 4 cmH2O compared with the baseline setting may help to improve exercise tolerance by prolonging exercise duration.

[This corrects the article DOI: 10.1371/journal.pgen.1006348.].

Although aerosol delivery through mechanical ventilators has been used to administer various medications, little is known of administration with colistin. This in vitro evaluation aimed to evaluate size distribution of colistin delivery by different types of nebulizers and concentrations during mechanical ventilation. Colistin methanesulfonate (colistin) for injection was dissolved in 6 mL of distilled water to produce a low concentration (L; 156 mg) and a high concentration (H; 312 mg). A dose volume of 6 mL was placed in a vibrating mesh nebulizer (VMN) and a jet nebulizer (JN). The inhaled mass (mean ± SD) of the VMN-L (53.80 ± 14.79 mg) was greater than both the JN-L (19.82 ± 3.34 mg, P = 0.001) and JN-H (31.72 ± 4.48 mg, P = 0.017). The nebulization time of the VMN-L (42.35 ± 2.30 min) was two times longer than the JN-L (21.12 ± 0.8 min) or JN-H (21.65 ± 0.42 min; P < 0.001). The mass median aerodynamic distal to the endotracheal tube was within a similar range at 2.03 to 2.26 μm (P = 0.434), independent of neb or formulation concentration. In conclusion, the VMN-L yields greater inhaled mass than the JN with either concentration. Therefore, a standard nominal dose of colistin results in a higher delivered dose during mechanical ventilation with a VMN compared with a JN and may be considered the preferred device. If JN must be used, multiple doses of low concentration colistin may compensate for poor delivery performance.

Ectomycorrhizal fungi (EMF) represent one of the major guilds of symbiotic fungi associated with roots of forest trees, where they function to improve plant nutrition and fitness in exchange for plant carbon. Many groups of EMF exhibit preference or specificity for different plant host genera; a good example is the genus Suillus, which grows in association with the conifer family Pinaceae. We investigated genetics of EMF host-specificity by cross-inoculating basidiospores of five species of Suillus onto ten species of Pinus, and screened them for their ability to form ectomycorrhizae. Several Suillus spp. including S. granulatus, S. spraguei, and S. americanus readily formed ectomycorrhizae (compatible reaction) with white pine hosts (subgenus Strobus), but were incompatible with other pine hosts (subgenus Pinus). Metatranscriptomic analysis of inoculated roots reveals that plant and fungus each express unique gene sets during incompatible vs. compatible pairings. The Suillus-Pinus metatranscriptomes utilize highly conserved gene regulatory pathways, including fungal G-protein signaling, secretory pathways, leucine-rich repeat and pathogen resistance proteins that are similar to those associated with host-pathogen interactions in other plant-fungal systems. Metatranscriptomic study of the combined Suillus-Pinus transcriptome has provided new insight into mechanisms of adaptation and coevolution of forest trees with their microbial community, and revealed that genetic regulation of ectomycorrhizal symbiosis utilizes universal gene regulatory pathways used by other types of fungal-plant interactions including pathogenic fungal-host interactions.

To investigate the ion activities of cells based on light-addressable potentiometric sensor (LAPS) platform, various high-dielectric constant sensing membrane were investigated the visibility and potential issue. Three different kinds of well-proven materials in semiconductor industry, such as Si3N4, NbOx, and TiN, are the promising sensing membranes to directly culture C3A cells. TiN and NbOx could be the potential candidate. The photocurrent and flatband voltage difference generated by acidification reaction is verified to observe by LAPS is the future.

To measure the ion activities of cells, an easy-access and fully-integrated system is necessary in culture room with high cleanness and easy maintenance. A new sensor structure integrated with readout system based on light-addressable potentiometric sensor (LAPS) to quantitatively monitor real-time cell activity with the advantages of label free and 2D image ability is proposed. The difference of cell number and acidification could be easily observed by 2D images by means of this proposed methodology.

Elsinochrome pigments produced by many phytopathogenic Elsinoë spp. are nonhost-selective toxins which react with oxygen molecules after light activation to produce highly toxic reactive oxygen species. The structures and chemical properties of four derivatives are well known. However, the biological roles of elsinochromes in fungal pathogenesis are poorly understood. Many isolates of Elsinoë fawcettii causing citrus scab are able to produce elsinochromes under axenic conditions. In this article, we report the cloning, expression, and functional characterization of the polyketide synthase-encoding gene, EfPKS1, which we show is required for the production of elsinochromes and fungal pathogenesis. Targeted disruption of EfPKS1 in E.fawcettii completely abrogated elsinochrome production, drastically reduced conidiation, and significantly decreased lesion formation on rough lemon leaves. All mutant phenotypes were restored to the wild type in fungal strains expressing a functional copy of EfPKS1. Accumulation of the EfPKS1 transcript and elsinochromes by a wild-type strain appears to be coordinately regulated by light, nutrients, and pH. The results indicate that the product of EfPKS1 is involved in the biosynthesis of elsinochromes via a fungal polyketide pathway, and that elsinochromes play an important role in fungal pathogenesis.

In the present study, UV light induced desorption of nitrogen dioxide (NO2) on pristine graphene based gas sensor is used to improve the sensing performance. Compared to the sample without UV light exposure, the response is 12%, 18% and 21% for NO2 concentrations of 1, 3 and 5 ppm. In addition, the recovery could be speeded up by UV irradiation. The sensor shows good behavior of repeatability when tested for 1 ppm of NO2 in 3 cycles. The graphene sensor with UV irradiation has a higher sensitivity to NO2 than to other gases under higher concentrations.

Five derivatives of 2-imino-3-(4-arylthiazol-2-yl)-thiazolidin-4-ones and a series of their 5-arylidene derivatives have been synthesized and tested for antifungal activity against seven agricultural fungi. 2-Imino-3-(2,4-dichloro-5-fluorophenylthiazol-2-yl)-4-thiazolidi-none and 2-imino-3-(2,4-dichlorophenylthiazol-2-yl)-4-thiazolidione, both of them new compounds, exhibited higher fungicidal effects than the other compounds prepared.

In curved space-time, the Hamilton-Jacobi equation is a semi-classical particle equation of motion, which plays an important role in the research of black hole physics. In this paper, starting from the Dirac equation of spin 1/2 fermions and the Rarita-Schwinger equation of spin 3/2 fermions, respectively, we derive a Hamilton-Jacobi equation for the non-stationary spherically symmetric gravitational field background. Furthermore, the quantum tunneling of a charged spherically symmetric Kinnersly black hole is investigated by using the Hamilton-Jacobi equation. The result shows that the Hamilton-Jacobi equation is helpful to understand the thermodynamic properties and the radiation characteristics of a black hole. [ABSTRACT FROM AUTHOR]

Integuments form important protective cell layers surrounding the developing ovules in gymno- and angiosperms. Although several genes have been shown to influence the development of integuments, the transcriptional regulatory mechanism is still poorly understood. In this work, we report that the Class II KNOTTED1-LIKE HOMEOBOX (KNOX II) transcription factors KNOTTED1-LIKE HOMEBOX GENE 3 (KNAT3) and KNAT4 regulate integument development in Arabidopsis (Arabidopsis thaliana). KNAT3 and KNAT4 were co-expressed in inflorescences and especially in young developing ovules. The loss-of-function double mutant knat3 knat4 showed an infertility phenotype, in which both inner and outer integuments of the ovule are arrested at an early stage and form an amorphous structure as in the bell1 (bel1) mutant. The expression of chimeric KNAT3- and KNAT4-EAR motif repression domain (SRDX repressors) resulted in severe seed abortion. Protein-protein interaction assays demonstrated that KNAT3 and KNAT4 interact with each other and also with INNER NO OUTER (INO), a key transcription factor required for the outer integument formation. Transcriptome analysis showed that the expression of genes related with integument development is influenced in the knat3 knat4 mutant. The knat3 knat4 mutant also had a lower indole-3-acetic acid (IAA) content, and some auxin signaling pathway genes were downregulated. Moreover, transactivation analysis indicated that KNAT3/4 and INO activate the auxin signaling gene IAA INDUCIBLE 14 (IAA14). Taken together, our study identified KNAT3 and KNAT4 as key factors in integument development in Arabidopsis. [ABSTRACT FROM AUTHOR]

Abstract Objective To explore the effects of the autonomous sensory meridian response (ASMR) on the psychological cravings and anxiety of women compulsorily isolated for detoxification. Method Around 122 women were recruited in a female drug detoxification center. Except for the 12‐week training of ASMR, the experimental conditions of the experimental group (n = 60) were the same as those of the control group (n = 62). The addiction Stroop task was used to assess the level of psychological cravings and the State‐Trait Anxiety Inventory was used to assess the level of anxiety. Results After the training, the decrease in state anxiety of the experimental group was larger than that of the control group, and the reaction time of the experimental group in the Stroop was also significantly lower than before the training. Conclusions ASMR could thus reduce to a certain extent the state anxiety and attentional bias for drug‐related clues under signaling psychological cravings among women compulsorily isolated for detoxification. HIGHLIGHTS Intervention effects on psychological cravings and anxiety of women isolated for detoxification Basis for role of ASMR in regulating psychological cravings and anxiety in forced abstainers ASMR intervention reduced forced abstainers’ attentional bias to drug‐related clues

Atrial fibrillation (AF) can be a potentially life-threatening arrhythmia when it conducts rapidly through the accessory pathway, which was not predicted by the noninvasive method. We evaluated the cardiac sympathetic activity for predicting the occurrence of AF in patients with Wolff-Parkinson-White (WPW) syndrome. Iodine-123 metaiodobenzylguanidine scintigraphy was performed under stable sinus rhythm conditions at rest <1 week before an electrophysiologic study (EPS) to assess the sympathetic activity using the heart/mediastinum (H/M) ratio in 45 consecutive patients with WPW who had a history of supraventricular tachycardia (mean ± SD, age: 47 ± 17 years, 42.2% women). The study also included 15 normal healthy volunteers (56 ± 17 years, 40% women). The H/M ratio was lower in patients with WPW syndrome than in the normal control group, and in the 15 patients with AF induced during EPS than in the 30 patients without AF (p <0.0001). The sensitivity of H/M ratio ≤2.8 for predicting the AF induced during EPS was 75% in 12 of 16 patients, and the specificity was 89.7% in 26 of 29 patients. The H/M ratio was positively correlated with anterograde effective refractory period (r = 0.514, p <0.0001). The sensitivity of H/M ratio ≤2.75 for predicting the AF with a short anterograde effective refractory period (≤250 ms) was 91.7% in 11 of 12 patients, and the specificity was 90.9% in 30 of 33 patients. In conclusion, the severe cardiac sympathetic dysfunction was associated with the occurrence of AF, particularly in those with rapid AF and in patients with WPW syndrome. [ABSTRACT FROM AUTHOR]