Neurophysiological features of Internet gaming disorder and alcohol use disorder: a resting-state EEG study

Despite that Internet gaming disorder (IGD) shares clinical, neuropsychological and personality characteristics with alcohol use disorder (AUD), little is known about the resting-state quantitative electroencephalography (QEEG) patterns associated with IGD and AUD. Therefore, this study compared the QEEG patterns in patients with IGD with those in patients with AUD to identify unique neurophysiological characteristics that can be used as biomarkers of IGD. A total of 76 subjects (34 with IGD, 17 with AUD and 25 healthy controls) participated in this study. Resting-state, eyes-closed QEEGs were recorded, and the absolute and relative power of brains were analyzed. The generalized estimating equation showed that the IGD group had lower absolute beta power than AUD (estimate = 5.319, P < 0.01) and the healthy control group (estimate = 2.612, P = 0.01). The AUD group showed higher absolute delta power than IGD (estimate = 7.516, P < 0.01) and the healthy control group (estimate = 7.179, P < 0.01). We found no significant correlations between the severity of IGD and QEEG activities in patients with IGD. The current findings suggest that lower absolute beta power can be used as a potential trait marker of IGD. Higher absolute power in the delta band may be a susceptibility marker for AUD. This study clarifies the unique characteristics of IGD as a behavioral addiction, which is distinct from AUD, by providing neurophysiological evidence.

In vitro evaluation of translating and rotating plates using a robot testing system under follower load

BACKGROUND CONTEXT

Various modifications to standard "rigid" anterior cervical plate designs (constrained plate) have been developed that allow for some degree of axial translation and/or rotation of the plate (semi-constrained plate)-theoretically promoting proper load sharing with the graft and improved fusion rates. However, previous studies about rigid and dynamic plates have not examined the influence of simulated muscle loading.

PURPOSE

The objective of this study was to compare rigid, translating, and rotating plates for single-level corpectomy procedures using a robot testing system with follower load.

STUDY DESIGN

In-vitro biomechanical test.

METHODS

N = 15 fresh-frozen human (C3-7) cervical specimens were biomechanically tested. The follower load was applied to the specimens at the neutral position from 0 to 100 N. Specimens were randomized into a rigid plate group, a translating plate group and a rotating plate group and then tested in flexion, extension, lateral bending and axial rotation to a pure moment target of 2.0 Nm under 100N of follower load. Range of motion, load sharing, and adjacent level effects were analyzed using a repeated measures analysis of variance (ANOVA).

RESULTS

No significant differences were observed between the translating plate and the rigid plate on load sharing at neutral position and C4-6 ROM, but the translating plate was able to maintain load through the graft at a desired level during flexion. The rotating plate shared less load than rigid and translating plates in the neutral position, but cannot maintain the graft load during flexion.

CONCLUSIONS

This study demonstrated that, in the presence of simulated muscle loading (follower load), the translating plate demonstrated superior performance for load sharing compared to the rigid and rotating plates.

Biologically and Acoustically Compatible Chamber for Studying Ultrasound-Mediated Delivery of Therapeutic Compounds

Ultrasound (US), in combination with microbubbles, has been found to be a potential alternative to viral therapies for transfecting biological cells. The translation of this technique to the clinical environment, however, requires robust and systematic optimization of the acoustic parameters needed to achieve a desired therapeutic effect. Currently, a variety of different devices have been developed to transfect cells in vitro, resulting in a lack of standardized experimental conditions and difficulty in comparing results from different laboratories. To overcome this limitation, we propose an easy-to-fabricate and cost-effective device for application in US-mediated delivery of therapeutic compounds. It comprises a commercially available cell culture dish coupled with a silicon-based "lid" developed in-house that enables the device to be immersed in a water bath for US exposure. Described here are the design of the device, characterization of the sound field and fluid dynamics inside the chamber and an example protocol for a therapeutic delivery experiment.

Contribution of Clostridium difficile infection to the development of lower gastrointestinal adverse events during autologous stem cell transplantation

BACKGROUND

Lower gastrointestinal (GI) adverse events (LGAE) are common afflictions of patients undergoing stem cell transplantation (SCT). Unfortunately, the pathophysiology remains poorly characterized. Emerging data suggest a prominent role of intestinal microbiota; however, contributions of pathogenic gut microbiota such as Clostridium difficile are not well defined. We performed a genome-wide association study (GWAS) to investigate clinical and genetic factors associated with development of LGAE.

METHODS

A total of 972 patients undergoing autologous SCT were graded for LGAE based on Common Terminology Criteria for Adverse Events (v 4.0). Germline DNA material was obtained from leukapharesis products and genotyped using Illumina(®) Whole Genome Genotyping Infinium chemistry and HumanOmni1-Quad Bead chips containing over 1.1 million single nucleotide polymorphisms (SNPs) (Illumina, San Diego, California, USA). Statistical models incorporating clinical factors, genetic factors, and a combination of clinical plus genetic factors were utilized to compare patients who developed severe LGAE (grade 2 or above) and others.

RESULTS

Among 972 patients, 459 (47.2%) developed severe LGAE. Baseline hemoglobin and hematocrit, estimated glomerular filtration rate, β2-microglobulin, protocol type, and C. difficile infection (CDI) were associated with severe LGAE on univariate analysis, Genomic comparisons between groups did not reveal any SNPs associated with severe LGAE and neither did incorporation of genetic factors into the clinical model. In addition, 11 candidate SNPs associated with upper GI mucositis were evaluated, alongside clinical factors in a multivariate model. Only CDI was found to be associated with severe LGAE in all models.

CONCLUSION

CDI is a prominent factor in the development of LGAE in patients undergoing autologous SCT.

The diversity of mechanisms influenced by transthyretin in neurobiology: development, disease and endocrine disruption

Transthyretin (TTR) is a protein that binds and distributes thyroid hormones (THs). TTR synthesised in the liver is secreted into the bloodstream and distributes THs around the body, whereas TTR synthesised in the choroid plexus is involved in movement of thyroxine from the blood into the cerebrospinal fluid and the distribution of THs in the brain. This is important because an adequate amount of TH is required for normal development of the brain. Nevertheless, there has been heated debate on the role of TTR synthesised by the choroid plexus during the past 20 years. We present both sides of the debate and how they can be reconciled by the discovery of TH transporters. New roles for TTR have been suggested, including the promotion of neuroregeneration, protection against neurodegeneration, and involvement in schizophrenia, behaviour, memory and learning. Recently, TTR synthesis was revealed in neurones and peripheral Schwann cells. Thus, the synthesis of TTR in the central nervous system (CNS) is more extensive than previously considered and bolsters the hypothesis that TTR may play wide roles in neurobiological function. Given the high conservation of TTR structure, function and tissue specificity and timing of gene expression, this implies that TTR has a fundamental role, during development and in the adult, across vertebrates. An alarming number of 'unnatural' chemicals can bind to TTR, thus potentially interfering with its functions in the brain. One role of TTR is delivery of THs throughout the CNS. Reduced TH availability during brain development results in a reduced IQ. The combination of the newly discovered sites of TTR synthesis in the CNS, the increasing number of neurological diseases being associated with TTR, the newly discovered functions of TTR and the awareness of the chemicals that can interfere with TTR biology render this a timely review on TTR in neurobiology.

Surface modification of neural electrodes with pyrrole-hyaluronic acid conjugate to attenuate reactive astrogliosis in vivo

Surface of neural probes were electrochemically modified with a non-cell adhesive and biocompatible conjugate, pyrrole-hyaluronic acid (PyHA), to reduce reactive astrogliosis. Poly(PyHA)-modified wire electrodes were implanted into rat motor cortices for three weeks and were found to markedly reduce the expression of glial fibrillary acidic protein compared to uncoated electrodes.

Generic piperacillin/tazobactam is not associated with galactomannan false-positivity in adult patients with cancer: a case-control study

Recent products of piperacillin/tazobactam (PTZ) from the original manufacturer, previously considered a major cause of galactomannan (GM) false-positivity, are reported not to be related to it. However, data regarding generic PTZ are limited and controversial. To evaluate the effect of generic PTZ on GM false-positivity in Korea, we performed a case-control study in adult patients with cancer. A case-control study was designed. Electronic medical records of cancer patients who were admitted and tested for serum GM between March and June 2014 at a tertiary care university hospital were reviewed. During the study period, a single generic PTZ (C manufacturer, Korea) was used. Patients who received PTZ within 24 h prior to serum GM testing were enrolled. Age- and GM test date-matched non-PTZ patients were selected as controls. A total of 110 patients received PTZ within 24 h prior to serum GM testing during the study period. The GM optical density index (ODI) of the PTZ group did not vary significantly from that of the control group (p = 0.251). The percentage of false-positive patients in the PTZ group was also similar to that of the control group (p = 0.538). There was no statistical relationship between GM ODI titer and time interval from PTZ administration (p = 0.095) or cumulative PTZ dose (p = 0.416). In a case-control study that evaluated 220 patients, a generic PTZ in Korea was not related to GM false-positivity.

Detecting disease association signals with multiple genetic variants and covariates

Due to the improvements in the efficiency of resequencing technologies, discoveries and analyses of rare variants in sequencing-based association studies at the gene level, or even exome-wide are becoming increasingly feasible. Powerful association tests have been suggested in literature for testing whether a group of variants in a gene region is associated with a particular disease of interest. Their performance depends on the correct assumption of regression model and conditions such as the size of the case and control sample, numbers of causal and noncausal variants (rare or common), variant frequency, effect size and directionality, rate of missing genotype, etc. Most of these model-based tests require genotype data to be complete at each variant. Our previous results showed that in the case of no covariate, the power of these tests might be greatly influenced, when there were missing genotypes and only simple imputation was used. In this paper, we demonstrate by simulations that in the presence of covariates, the type I errors of these approaches might be inflated, even when genotype missing rate was very small. We present an association test based on testing zero proportion of causal variants in the gene region, and show this test to be almost uniformly most powerful among the competing tests under very general simulation conditions. This test does not require genotype to be complete and hence is robust against missing genotype. We discuss how to adjust for population stratification based on principal components and show the power loss of this approach was small when the population stratification effect was moderate. We use a Shanghai Breast Cancer Study to demonstrate application of the tests and show the proposed test is more powerful in detecting variants related to breast cancer, and robust against the inclusion of noncausal variants.

Changes in the influence of lymphoma- and HIV-specific factors on outcomes in AIDS-related non-Hodgkin lymphoma

BACKGROUND

We undertook the present analysis to examine the shifting influence of prognostic factors in HIV-positive patients diagnosed with aggressive non-Hodgkin lymphoma (NHL) over the last two decades.

PATIENTS AND METHODS

We carried out a pooled analysis from an existing database of patients with AIDS-related lymphoma. Individual patient data had been obtained prior from prospective phase II or III clinical trials carried out between 1990 until 2010 in North America and Europe that studied chemo(immuno)therapy in HIV-positive patients diagnosed with AIDS-related lymphomas. Studies had been identified by a systematic review. We analyzed patient-level data for 1546 patients with AIDS-related lymphomas using logistic regression and Cox proportional hazard models to identify the association of patient-, lymphoma-, and HIV-specific variables with the outcomes complete response (CR), progression-free survival, and overall survival (OS) in different eras: pre-cART (1989-1995), early cART (1996-2000), recent cART (2001-2004), and contemporary cART era (2005-2010).

RESULTS

Outcomes for patients with AIDS-related diffuse large B-cell lymphoma and Burkitt lymphoma improved significantly over time, irrespective of baseline CD4 count or age-adjusted International Prognostic Index (IPI) risk category. Two-year OS was best in the contemporary era: 67% and 75% compared with 24% and 37% in the pre-cART era (P < 0.001). While the age-adjusted IPI was a significant predictor of outcome in all time periods, the influence of other factors waxed and waned. Individual HIV-related factors such as low CD4 counts (<50/mm(3)) and prior history of AIDS were no longer associated with poor outcomes in the contemporary era.

CONCLUSIONS

Our results demonstrate a significant improvement of CR rate and survival for all patients with AIDS-related lymphomas. Effective HIV-directed therapies reduce the impact of HIV-related prognostic factors on outcomes and allow curative antilymphoma therapy for the majority of patients with aggressive NHL.

Microfluidic system for high throughput characterisation of echogenic particles

Echogenic particles, such as microbubbles and volatile liquid micro/nano droplets, have shown considerable potential in a variety of clinical diagnostic and therapeutic applications. The accurate prediction of their response to ultrasound excitation is however extremely challenging, and this has hindered the optimisation of techniques such as quantitative ultrasound imaging and targeted drug delivery. Existing characterisation techniques, such as ultra-high speed microscopy provide important insights, but suffer from a number of limitations; most significantly difficulty in obtaining large data sets suitable for statistical analysis and the need to physically constrain the particles, thereby altering their dynamics. Here a microfluidic system is presented that overcomes these challenges to enable the measurement of single echogenic particle response to ultrasound excitation. A co-axial flow focusing device is used to direct a continuous stream of unconstrained particles through the combined focal region of an ultrasound transducer and a laser. Both the optical and acoustic scatter from individual particles are then simultaneously recorded. Calibration of the device and example results for different types of echogenic particle are presented, demonstrating a high throughput of up to 20 particles per second and the ability to resolve changes in particle radius down to 0.1 μm with an uncertainty of less than 3%.

Low-density lipoprotein-mimicking nanoparticles for tumor-targeted theranostic applications

This study introduces multifunctional lipid nanoparticles (LNPs), mimicking the structure and compositions of low-density lipoproteins, for the tumor-targeted co-delivery of anti-cancer drugs and superparamagnetic nanocrystals. Paclitaxel (4.7 wt%) and iron oxide nanocrystals (6.8 wt%, 11 nm in diameter) are co-encapsulated within folate-functionalized LNPs, which contain a cluster of nanocrystals with an overall diameter of about 170 nm and a zeta potential of about -40 mV. The folate-functionalized LNPs enable the targeted detection of MCF-7, human breast adenocarcinoma expressing folate receptors, in T2 -weighted magnetic resonance images as well as the efficient intracellular delivery of paclitaxel. Paclitaxel-free LNPs show no significant cytotoxicity up to 0.2 mg mL(-1) , indicating the excellent biocompatibility of the LNPs for intracellular drug delivery applications. The targeted anti-tumor activities of the LNPs in a mouse tumor model suggest that the low-density lipoprotein-mimetic LNPs can be an effective theranostic platform with excellent biocompatibility for the tumor-targeted co-delivery of various anti-cancer agents.

Multilevel hierarchy of fluorinated wax on CuO nanowires for superoleophobic surfaces

We demonstrate the multilevel hierarchy of nanoscale wax crystals on nanowire (NW) structures that strongly repels not only water but also olive oil and hexadecane. We deposited C24F50-fluorinated wax (F-wax) using thermal evaporation on the surface of CuO NWs. Fluorinated wax crystals are self-assembled on the CuO NWs forming three-dimensional hierarchical structures. The achieved multilevel hierarchy has strongly repelled water, glycerol, ethylene glycol, and olive oil with contact angles (CAs) exceeding 160°. When sufficient F-wax is crystallized on the CuO NWs, crystals that are assembled perpendicularly to the longitudinal NW axis form a re-entrant curvature allowing superoleophobic characteristics with strong repellence of hexadecane with CAs of ∼150° and a small contact angle hysteresis of <10°. Furthermore, the surfaces can repel extremely small water droplets (∼100 pL), an indication of an ability to withstand condensation. These types of multilevel hierarchies can be formed on numerous roughened surfaces as the wax can be easily applied to various substrates without affecting the mechanical integrity of base structures.

Increased expression of GDF-15 may mediate ICU-acquired weakness by down-regulating muscle microRNAs

Rationale

The molecular mechanisms underlying the muscle atrophy of intensive care unit-acquired weakness (ICUAW) are poorly understood. We hypothesised that increased circulating and muscle growth and differentiation factor-15 (GDF-15) causes atrophy in ICUAW by changing expression of key microRNAs.

Objectives

To investigate GDF-15 and microRNA expression in patients with ICUAW and to elucidate possible mechanisms by which they cause muscle atrophy in vivo and in vitro.

Methods

In an observational study, 20 patients with ICUAW and seven elective surgical patients (controls) underwent rectus femoris muscle biopsy and blood sampling. mRNA and microRNA expression of target genes were examined in muscle specimens and GDF-15 protein concentration quantified in plasma. The effects of GDF-15 on C2C12 myotubes in vitro were examined.

Measurements and main results

Compared with controls, GDF-15 protein was elevated in plasma (median 7239 vs 2454 pg/mL, p=0.001) and GDF-15 mRNA in the muscle (median twofold increase p=0.006) of patients with ICUAW. The expression of microRNAs involved in muscle homeostasis was significantly lower in the muscle of patients with ICUAW. GDF-15 treatment of C2C12 myotubes significantly elevated expression of muscle atrophy-related genes and down-regulated the expression of muscle microRNAs. miR-181a suppressed transforming growth factor-β (TGF-β) responses in C2C12 cells, suggesting increased sensitivity to TGF-β in ICUAW muscle. Consistent with this suggestion, nuclear phospho-small mothers against decapentaplegic (SMAD) 2/3 was increased in ICUAW muscle.

Conclusions

GDF-15 may increase sensitivity to TGF-β signalling by suppressing the expression of muscle microRNAs, thereby promoting muscle atrophy in ICUAW. This study identifies both GDF-15 and associated microRNA as potential therapeutic targets.

The 'either test positive' strategy for latent tuberculous infection before anti-tumour necrosis factor treatment

SETTING

A ttertiary referral centre in South Korea.

OBJECTIVES

The 'either test positive' strategy, incorporating both the tuberculin skin test (TST) and the T-SPOT(®).TB(T-SPOT) assay, was evaluated as a novel method for diagnosing latent tuberculous infection (LTBI) before treatment with anti-tumour necrosis factor (TNF) in patients with immune-mediated inflammatory diseases.

DESIGN

From June 2008 to April 2012, 430 patients received anti-TNF treatment at our institution. TST and T-SPOT were performed simultaneously at baseline. LTBI was defined as a positive TST or a positive T-SPOT result.

RESULTS

The positivity rates for the TST and T-SPOT assays were respectively 19.1% (82/430) and 44.2% (190/430), yielding an LTBI-positive rate of 48.6% (209/430). LTBI treatment was initiated in 46.0% (198/430) of patients and was completed by 89.4% (177/198). During follow-up (median 884 days), 0.9% (4/430) of the patients developed active tuberculosis (TB). All four TB patients were TST-negative at baseline, although two received LTBI treatment based on the baseline positive T-SPOT assay results.

CONCLUSIONS

The either test positive strategy is a valid method for diagnosing LTBI before anti-TNF treatment, although it is not clear whether it is superior to other strategies.