Second Data Release from the European Pulsar Timing Array: Challenging the Ultralight Dark Matter Paradigm

Pulsar Timing Array experiments probe the presence of possible scalar or pseudoscalar ultralight dark matter particles through decade-long timing of an ensemble of galactic millisecond radio pulsars. With the second data release of the European Pulsar Timing Array, we focus on the most robust scenario, in which dark matter interacts only gravitationally with ordinary baryonic matter. Our results show that ultralight particles with masses 10^{-24.0}  eV≲m≲10^{-23.3}  eV cannot constitute 100% of the measured local dark matter density, but can have at most local density ρ≲0.3  GeV/cm^{3}.

Spatially Resolved Whole Transcriptome Analysis of Histologically-Characterized Tissue Microarray of Patient-Matched Primary and Recurrent Glioblastomas to Identify Underlying Mechanisms of Treatment Resistance

PURPOSE/OBJECTIVE(S)

Glioblastoma multiforme (GBM) is a lethal CNS malignancy. Radiation therapy increases overall survival, but tumors often recur in high-radiation dose regions. Additionally, recent investigations have underscored the importance of intra-tumoral heterogeneity as a driver of GBM biology. The purpose of this investigation is to characterize transcriptome differences in primary and recurrent GBM patient clinical samples using a digital spatial profiling approach to better appreciate treatment resistance mechanisms.

MATERIALS/METHODS

To address the lack of understanding of molecular mechanisms of resistance in GBM, patient-matched primary and recurrent GBM pathological specimens were identified within the brain tissue biorepository and tissue cores were selected for generation of a tissue microarray (TMA). Hematoxylin and eosin staining with histomorphological (cellular tumor, pseudopalisading necrosis, invasive edge, and perivascular inflammation) scoring were performed in a blinded fashion for every core. This array was then molecularly characterized using digital spatial profiling of the transcriptome. Quality assurance including filtering of lowly expressed genes followed by downstream analyses of the data were performed using the manufacturer's recommended methods within their Bioconductor library. Gene Set Enrichment Analysis (GSEA) was then performed on the ranked gene lists.

RESULTS

After recommended filtering, 6171 genes and 248 regions of interest remained for downstream analysis representing 22 unique patients across four different tumor histomorphological types. Significance testing revealed 679 genes that were differentially expressed between primary and recurrent tumor samples (at FDR<1%). On GSEA analysis, the chromosomal positional locus that contains genes most strongly up-regulated is 12q14, a locus that was previously identified as genomically amplified in multiple patient-derived xenograft lines after radiation selection. Additionally, recurrent tumors display a transcriptional profile more similar to the mesenchymal subtype, whereas primary tumors have a more classical transcriptional phenotype. The epithelial-to-mesenchymal transition pathway is particularly strongly up-regulated in recurrent tumors.

CONCLUSION

Recurrent selection at previously identified genomic loci and molecular pathways underscores a possible conserved set of pathways for treatment resistance. This analysis has yielded a set of gene and molecular pathways that will guide future work in our lab targeting treatment resistance using novel therapeutics and radiation techniques in GBM. Future directions include assessing the feasibility of mapping these clinical samples onto our previously generated panel of comprehensively characterized patient-derived xenograft lines.

Comparison of trans-radial access and femoral access in cardiogenic shock patient who had undergone primary percutaneous coronary intervention from SMART RESCUE trial

Introduction

Throughout the years of percutaneous coronary intervention (PCI), the debate regarding access route, whether it being trasns-radial or femoral, is an ongoing agenda yet to be solved. Recent guidelines suggest trans-radial approach as an option to be considered in acute coronary syndrome (ACS). However, data on cardiogenic shock patients undergoing PCI is relatively sparse.

Purpose

Compare the clinical implication of trans-radial and femoral approach in cardiogenic shock patients who had undergone PCI.

Method

Cardiogenic shock patients who had undergone PCI from January 2014 to December of 2018 were enrolled. Patients were divided according to their access route respectfully. Primary outcome was composite endpoints including all-cause death, re-admission due to heart failure, myocardial infarction (MI) and cerebrovascular accident.

Result

A total of 694 (572 via femoral approach, 122 via radial approach) cardiogenic shock patients who received PCI were enrolled. Mean age femoral and radial groups was 66.59±12.51 and 66.66±12.8 respectfully. Disease severity was higher for femoral patients compared to radial patients as represented by their LM involvement, mechanical organ support (extracorporeal membrane oxygenation, continuous renal replacement therapy, mechanical ventilation), left ventricular ejection fraction (LVEF) and vasoactive inotropic score. Cox regression analysis after adjusting for conventional risk factors showed that femoral route was a poor prognosticator with respect to composite endpoints (HR=2.059, 95% CI 1.249–3.397, p value = 0.005). Radial approach patients had higher survival probability compared to femoral approach patients (Figure 1).

Conclusion

Radial approach in cardiogenic shock patients who are in need for PCI with relatively less severe clinical condition could be a reasonable option for access route.

Funding Acknowledgement

Type of funding sources: Private hospital(s). Main funding source(s): Inha University Hospital

The complex of Fas-associated factor 1 with Hsp70 stabilizes the adherens junction integrity by suppressing RhoA activation

Fas-associated factor 1 (FAF1) is a scaffolding protein that plays multiple functions, and dysregulation of FAF1 is associated with many types of diseases such as cancers. FAF1 contains multiple ubiquitin-related domains (UBA, UBL1, UBL2, UAS, and UBX), each domain interacting with a specific partner. In particular, the interaction of UBL1 with heat shock protein 70 (Hsp70) is associated with tumor formation, although the molecular understanding remains unknown. In this study, the structural analysis revealed that His160 of FAF1 is important for its interaction with Hsp70. The association of Hsp70 with FAF1 is required for the interaction with IQGAP1. FAF1 negatively regulates RhoA activation by FAF1–Hsp70 complex formation, which then interacts with IQGAP1. These steps play a key role in maintaining the stability of cell-to-cell junction. We conclude that FAF1 plays a critical role in the structure and function of adherens junction during tissue homeostasis and morphogenesis by suppressing RhoA activation, which induces the activation of Rho-associated protein kinase, phosphorylation of myosin light chain, formation of actin stress fiber, and disruption of adherens junction. In addition, depletion of FAF1 increased collective invasion in a 3D spheroid cell culture. These results provide insight into how the FAF1–Hsp70 complex acts as a novel regulator of the adherens junction integrity. The complex can be a potential therapeutic target to inhibit tumorigenesis and metastasis.

Guiding Chemically Synthesized Peptide Drug Lead Optimization by Derisking Mast Cell Degranulation-Related Toxicities of a NaV1.7 Peptide Inhibitor

Studies have shown that some peptides and small molecules can induce non IgE-mediated anaphylactoid reactions through mast cell activation. Upon activation, mast cells degranulate and release vasoactive and proinflammatory mediators, from cytoplasmic granules into the extracellular environment which can induce a cascade of severe adverse reactions. This study describes a lead optimization strategy to select NaV1.7 inhibitor peptides that minimize acute mast cell degranulation (MCD) toxicities. Various in vitro, in vivo, and PKPD models were used to screen candidates and guide peptide chemical modifications to mitigate this risk. Anesthetized rats dosed with peptides demonstrated treatment-related decreases in blood pressure and increases in plasma histamine concentrations which were reversible with a mast cell stabilizer, supporting the MCD mechanism. In vitro testing in rat mast cells with NaV1.7 peptides demonstrated a concentration-dependent increase in histamine. Pharmacodynamic modeling facilitated establishing an in vitro to in vivo correlation for histamine as a biomarker for blood pressure decline via the MCD mechanism. These models enabled assessment of structure-activity relationship (SAR) to identify substructures that contribute to peptide-mediated MCD. Peptides with hydrophobic and cationic characteristics were determined to have an elevated risk for MCD, which could be reduced or avoided by incorporating anionic residues into the protoxin II scaffold. Our analyses support that in vitro MCD assessment in combination with PKPD modeling can guide SAR to improve peptide lead optimization and ensure an acceptable early in vivo tolerability profile with reduced resources, cycle time, and animal use.

Organizing a Successful Practice and Considering Tax and Estate Planning

To care for your family and to do "good" for your alma mater, religious organization, and the other charities you love, you need to do "well," which is to build a successful practice. To achieve a successful practice, following the principles of the dozen A's is helpful: Ability, Availability, Amicability, Approachable, Attuned, Aware, Attentive to patients, Attentive to others, Attentive to details, Apology (ability to apologize and accept apology gracefully), Assimilate, Affordable. Another way to put it is "skills to treat, heart to care at a sensible price."

Micro-electromechanical-system-tuned resonant filters spanning the 8-12 µm band

The spectral band covering ∼8-12µm is atmospherically transparent and therefore important for terrestrial imaging, day/night situational awareness systems, and spectroscopic applications. There is a dearth of tunable filters spanning the band. Here, we propose and demonstrate a new, to the best of our knowledge, tunable-filter method engaging the fundamental physics of the guided-mode resonance (GMR) effect realized with a non-periodic lattice. The polarization-dependent filter is fashioned with a one-dimensional Ge grating on a ZnSe substrate and interrogated with a ∼1.5mm Gaussian beam to show clear transmittance nulls. To expand the tuning range, the device parameters are optimized for sequential operation in TM and TE polarization states. The theoretical model exhibits a tunable range exceeding 4 µm, thus covering the band fully. In the experiment, a prototype device exhibits a spectral range of 8.6-10.0 µm in TM and 9.9-11.7 µm in TE polarization or >3µm total. With additional efforts in fabrication, we expect to achieve the full range.

No pulsed radio emission during a bursting phase of a Galactic magnetar

Fast radio bursts (FRBs) are millisecond-duration radio transients of unknown physical origin observed at extragalactic distances^1-3. It has long been speculated that magnetars are the engine powering repeating bursts from FRB sources^4-13, but no convincing evidence has been collected so far¹⁴. Recently, the Galactic magnetar SRG 1935+2154 entered an active phase by emitting intense soft γ-ray bursts¹⁵. One FRB-like event with two peaks (FRB 200428) and a luminosity slightly lower than the faintest extragalactic FRBs was detected from the source, in association with a soft γ-ray/hard-X-ray flare^18-21. Here we report an eight-hour targeted radio observational campaign comprising four sessions and assisted by multi-wavelength (optical and hard-X-ray) data. During the third session, 29 soft-γ-ray repeater (SGR) bursts were detected in γ-ray energies. Throughout the observing period, we detected no single dispersed pulsed emission coincident with the arrivals of SGR bursts, but unfortunately we were not observing when the FRB was detected. The non-detection places a fluence upper limit that is eight orders of magnitude lower than the fluence of FRB 200428. Our results suggest that FRB-SGR burst associations are rare. FRBs may be highly relativistic and geometrically beamed, or FRB-like events associated with SGR bursts may have narrow spectra and characteristic frequencies outside the observed band. It is also possible that the physical conditions required to achieve coherent radiation in SGR bursts are difficult to satisfy, and that only under extreme conditions could an FRB be associated with an SGR burst.

Unpolarized resonant notch filters for the 8-12 µm spectral region

The long-wave infrared (LWIR) spectral region spanning ∼8-12µm is useful for many scientific and industrial applications. As traditional multilayer film components are not straightforwardly realized at these bands, we provide design, fabrication, and testing of polarization independent bandstop filters based on the guided-mode resonance (GMR) effect. Focusing on the zero-contrast grating architecture, we successfully fabricate prototype filters in the Ge-on-ZnSe materials system. Applying mask-based photolithography and dry etching, photoresist patterns form the desired Ge grating structures. The resulting devices exhibit clean transmittance nulls and acceptably high sidebands. Moreover, we verify polarization independent notch filtering by assembling two identical GMR filters with gratings oriented orthogonally. This approach to realize effective GMR elements will be useful for various fields including photonic and optoelectronic devices operating in the LWIR region.

Role of a modified ultrafast MRI brain protocol in clinical paediatric neuroimaging

AIM

To establish a role for modified ultrafast magnetic resonance imaging (MRI) of the brain in clinical paediatric patients based on clinically acceptable image quality and diagnostic accuracy.

MATERIALS AND METHODS

A prospective study was conducted with institutional review board approval on an ultrafast MRI brain protocol consisting of sagittal T1-weighted, axial T2-weighted, axial fluid-attenuated inversion recovery (FLAIR), axial diffusion-weighted imaging (DWI), and axial T2∗-weighted sequences. Preliminary investigations revealed that the default ultrafast T2-weighted sequence was prone to pulsation artefacts. A modified ultrafast T2-weighted sequence was therefore developed to replace the default ultrafast T2-weighted sequence. Thirty-five patients with clinical indication for neuroimaging underwent ultrafast MRI, modified ultrafast T2-weighted sequence and standard MRI at 3 T. Image quality of ultrafast MRI sequences were graded as clinically "diagnostic" or "non-diagnostic" and compared against the corresponding standard MRI sequences as the reference standard. The modified ultrafast T2-weighted sequence surpassed the default ultrafast T2-weighted sequence in image quality. The ultrafast MRI protocol was therefore replaced with the modified ultrafast T2-weighted sequence creating a modified ultrafast MRI protocol. The clinical reports of modified ultrafast MRI were compared against standard MRI for diagnostic concordance, categorised further as "normal", "clinically significant", or "clinically minor" abnormalities.

RESULTS

Ultrafast T1-weighted, FLAIR, and DWI sequences had comparable image quality to standard MRI sequences. The ultrafast T2∗-weighted sequence had significantly higher non-diagnostic images (42.9%) compared to the standard MRI sequence (2.9%). The default ultrafast T2-weighted sequence had significantly higher non-diagnostic images compared to the modified ultrafast T2-weighted sequence and standard T2-weighted sequence (82.9%, 5.7%, 8.6%, respectively). There was 100% concordance for normal and clinically significant abnormalities and 23% discordance for clinically minor abnormalities. Modified ultrafast MRI takes 5 minutes 41 seconds compared to standard MRI time of 14 minutes 57 seconds.

CONCLUSION

The modified ultrafast MRI protocol for brain imaging demonstrates clinically acceptable image quality in four out of five sequences and has high accuracy in diagnosing normal and clinically significant abnormalities when compared against the standard MRI protocol for brain imaging. It could potentially benefit a select group of paediatric patients who require neuroimaging.

TEK is a novel prognostic marker for clear cell renal cell carcinoma

OBJECTIVE

Clear cell renal cell carcinoma (ccRCC) is the most common type of kidney cancer. However, effective therapeutics for ccRCC are lacking. Novel biomarkers could provide critical information when determining prognoses for patients with ccRCC. In this study, we sought to determine if the expression of receptor tyrosine kinase (TEK) could be a potential novel prognostic biomarker for ccRCC. TEK, originally identified as an endothelial cell-specific receptor, plays an important role in the modulation of vasculogenesis and remodeling. Altered TEK expression has been observed in tumor tissues (e.g., oral squamous cell carcinomas, leukemia) and breast, gastric and thyroid cancers. However, the role of TEK in ccRCC remains unknown.

PATIENTS AND METHODS

Differential TEK expression between non-metastatic (stage M0) and metastatic (stage M1) ccRCC patient cohorts was determined from The Cancer Genome Atlas (TCGA) and the International Cancer Genome Consortium (ICGC). Furthermore, TEK expression was assessed as a prognostic factor using the time-dependent area under the curve (AUC) of Uno's C-index, the AUC value of the receiver operating characteristics (ROC) at 5 years, Kaplan-Meier survival curves and multivariate analyses.

RESULTS

A Kaplan-Meier curve analysis revealed that the downregulation of TEK expression was associated with a poor prognosis for patients with ccRCC with good discrimination (p<0.0001 and p=0.0044 for the TGCA and ICGC cohorts, respectively). Analyses of C-indices and receiver operating characteristic AUC values further support this discriminative ability. Moreover, multivariate analyses showed the prognostic significance of TEK expression levels (p<0.001).

CONCLUSIONS

Although additional clinical investigations will be needed, our results suggest that TEK is a potential biomarker for ccRCC.

Otolaryngologist as a Political Leader?

Otolaryngologists are in a good position to advocate for our patients and our specialty. We can do it as a volunteer or as a full-time job running for political office at the state or federal level. To be taken seriously, we need to offer solutions besides citing the problems. We encourage otolaryngologists to work with our Academy and its ENT-PAC (Ear, Nose, Throat Political Action Committee). Medicine is a great profession and Otolaryngology-Head and Neck Surgery is an even better specialty.

The interplay of sun damage and genetic risk in Australian multiple and single primary melanoma cases and controls

BACKGROUND

Skin phenotype, host genotype and ultraviolet (UV) damage play a role in the development of melanoma.

OBJECTIVES

To ascertain whether the level of UV damage at the site of melanomas was associated with genetic polymorphisms.

METHODS

Deep phenotyping was performed on 1244 individuals; 281 with multiple primary melanomas (MPMs), 304 with single primary melanoma (SPM) and 659 convenience controls. Genotype data was generated using the Illumina CoreExome microarray platform, assaying over 500 000 single-nucleotide polymorphisms. A subset of variants were combined to assess a polygenic risk score (PRS) for melanoma.

RESULTS

Most MPM cases were diagnosed in patients aged > 40 years, in sites with visible chronic UV damage. Women and those diagnosed at age ≤ 40 years were less likely to have perilesional UV damage. Patients with MPM had higher frequencies of MITF E318K, MC1R R-alleles and the ASIP risk haplotype. Individuals who had melanoma in a visibly UV-damaged site were more likely to carry MC1R rs75570604 [odds ratio (OR) 2·5], 9q31.2 rs10816595 (OR 1·4) and MTAP rs869329 (OR 1·4). These same alleles were more common in patients with MPM who were diagnosed at age ≤ 40 years. The mean PRS was significantly higher in MPM than in SPM and controls. Naevus count was comparable in early-onset MPM cases and those diagnosed at age > 40 years.

CONCLUSIONS

Our cohort demonstrated higher frequencies of previously reported alleles associated with melanoma. MPM melanomas more commonly occur in UV-damaged areas, and these individuals are more likely to carry MC1R red hair colour alleles. Awareness of the interplay of genetic vulnerability with UV damage can stratify risk and guide recommendations for melanoma screening. What's already known about this topic? Skin phenotype, host genotype and ultraviolet (UV) damage all play a role in melanoma development. One of the main risk factors is a personal history of melanoma; second and subsequent primary melanomas account for over 20% of all melanomas registered in Queensland. Multiple loci are associated with melanoma risk, including many low-penetrance loci, which may have a cumulatively significant risk. Population-wide screening programmes for melanoma are not yet economically viable. What does this study add? Patients diagnosed with melanoma at age ≤ 40 years were more likely than older patients to have melanomas in non-UV-damaged sites. Patients with multiple melanomas had higher frequencies of MITF E318K, MC1R R-alleles, and the ASIP extended risk haplotype than patients with single melanoma. CDKN2A, MC1R and MTAP variants were more frequent in patients who developed melanomas at a younger age, but also in those whose melanomas were all on visibly UV-damaged sites. What is the translational message? Incorporating these genetic findings into the known risk factors of skin phenotype and visible UV damage may allow for a more customized and economically feasible approach to early detection of melanoma, particularly in younger patients. Plain language summary available online.

Prospective randomized comparison of cerebrospinal fluid aspiration and conventional popping methods using 27-gauge spinal needles in patients undergoing spinal anaesthesia

Background

Performing spinal anaesthesia using the conventional popping method with a 27-gauge (27G) spinal needle is technically difficult. In this study, we compared the aspiration and conventional popping method for spinal anaesthesia using 27G Quincke-type needles.

Methods

This prospective, randomized study enrolled 90 patients, aged 19 to 65 years, with American Society of Anesthesiologists physical status I-III, who were undergoing spinal anaesthesia. Patients were randomly assigned to one of two groups using a computer-generated random number table: patients receiving spinal anaesthesia using the aspiration method, in which the needle is advanced with continuous aspiration, or the conventional popping method. The primary outcome measure was the success rate of the first attempt to perform dural puncture. Number of attempts and passages, withdrawal cases, successful attempt time, total procedure time, and actual depth of dural puncture were recorded.

Results

Eighty-eight patients were included in the study. In the aspiration group, the success rate of first attempt for dural puncture was 93.3%, compared with 72.1% in the popping group (P = 0.019). Success involving needle withdrawal was recorded in 4 (8.9%) patients in the aspiration group and 13 (30.2%) in the popping group (P = 0.024). In the popping group, the number of attempts was significantly higher (P = 0.044), and total procedure time was significantly longer (P = 0.023). Actual depths of dural puncture were deeper in the popping group than in the aspiration group (P = 0.019).

Conclusions

The aspiration method using a 27G Quincke-type needle offers clinical benefits for dural puncture compared with the conventional popping method for spinal anaesthesia.

Trial registration

Clinical research information service number: KCT0002815, registered 21/Apr/2018. Retrospectively registered.

Phenotypic and genotypic analysis of amelanotic and hypomelanotic melanoma patients

BACKGROUND

Amelanotic/hypomelanotic melanoma is associated with poorer outcomes due to a more advanced disease stage at diagnosis.

OBJECTIVE

To determine phenotypic risks and genotypic associations with amelanotic/hypomelanotic melanoma to develop a clinical and genetic profile that could assist in identifying high-risk individuals.

METHODS

The Brisbane Naevus Morphology Study conducted from 2009 to 2016 has recruited a core of 1254 participants. Participants were drawn from a combination of volunteers from dermatology outpatient clinics, private dermatology clinics, the Brisbane Longitudinal Twin Study and QSkin study. Case participants had a personal history of melanoma and control participants no personal history of melanoma. We specifically examined seven known candidate pigmentation and melanoma genes and pigmentary phenotypic characteristics in participants with amelanotic/hypomelanotic melanoma compared to pigmented melanomas. This assayed single nucleotide polymorphisms in MC1R, TYR, HERC/OCA2, IRF4, MTAP, PLA2G6 and MITF.

RESULTS

Forty-seven participants had at least one amelanotic/hypomelanotic melanoma, and 389 had pigmented melanomas, with amelanotic/hypomelanotic melanoma patients significantly older than pigmented melanoma participants (63.3 ± 13.0 vs. 54.6 ± 15.3 years; P < 0.001). Amelanotic/hypomelanotic melanoma patients were more likely than pigmented melanoma patients to have red hair (34% vs. 15%; P = 0.01), severe hand freckling (13% vs. 5%; P = 0.01) and propensity to sunburn (63% vs. 44%; P = 0.01). MC1R R/R genotype was much more frequent in our amelanotic/hypomelanotic melanoma population (31.1% vs. 11%; P < 0.001; OR 26.4 vs. 5.9; control 1.0). Amelanotic/hypomelanotic melanoma was associated with TYR rs1126809*A/A [OR (CI 95%) 2.7 (1.1-6.8) vs. 1.2 (0.8-1.9)] and PLA2G6 rs11570734*A/A [OR (CI 95%) 3.7 (1.0-13.6) vs. 1.3 (0.9-2.0)]. The MTAP melanoma risk SNP genotype, associated with darker pigmentation, (rs4636294*A/A) was less common in amelanotic/hypomelanotic melanoma patients [OR (CI 95%) 0.8 (0.3-2.1) vs. 2.0 (1.3-3.1)].

CONCLUSIONS

Knowledge of phenotypic and genotypic associations of amelanotic/hypomelanotic melanoma can help predict risks and associations of this difficult to diagnose melanoma, which may ultimately assist clinical management and patient skin self-examination.

deMix: Decoding Deuterated Distributions from Heterogeneous Protein States via HDX-MS

Characterization of protein structural changes in response to protein modifications, ligand or chemical binding, or protein-protein interactions is essential for understanding protein function and its regulation. Amide hydrogen/deuterium exchange (HDX) coupled with mass spectrometry (MS) is one of the most favorable tools for characterizing the protein dynamics and changes of protein conformation. However, currently the analysis of HDX-MS data is not up to its full power as it still requires manual validation by mass spectrometry experts. Especially, with the advent of high throughput technologies, the data size grows everyday and an automated tool is essential for the analysis. Here, we introduce a fully automated software, referred to as ‘deMix’, for the HDX-MS data analysis. deMix deals directly with the deuterated isotopic distributions, but not considering their centroid masses and is designed to be robust over random noises. In addition, unlike the existing approaches that can only determine a single state from an isotopic distribution, deMix can also detect a bimodal deuterated distribution, arising from EX1 behavior or heterogeneous peptides in conformational isomer proteins. Furthermore, deMix comes with visualization software to facilitate validation and representation of the analysis results.

Activity-Regulated Cytoskeleton-Associated Protein (Arc/Arg3.1) is Transiently Expressed after Heat Shock Stress and Suppresses Heat Shock Factor 1

Heat shock proteins are induced by activation of heat shock factor 1 (HSF1) in response to heat shock and protect against heat stress. However, the molecular mechanisms underlying the downstream signal of heat shock have not been fully elucidated. We found that similarly to canonical Hsps, Arc/Arg3.1 is also markedly induced by heat shock and by other cellular stress inducers, including diamide, sodium arsenite and H₂O₂ in various cells. We noted that heat stress–induced Arc/Arg3.1 protein is short lived, with a half-life of <30 min, and is readily degraded by the ubiquitin–proteasome system. Arc/Arg3.1 overexpression inhibited the up-regulation of heat shock–induced Hsp70 and Hsp27, suggesting that Arc/Arg3.1 is a negative regulator of heat shock response (HSR). Studying the effect of Arc/Arg3.1 on HSF1, a major transcription factor in HSR, we found that Arc/Arg3.1 binds to HSF1 and inhibits its binding to the heat shock element in gene promoters, resulting in reduced induction of Hsp27 and Hsp70 mRNAs, without affecting HSF1′s phosphorylation-dependent activation, or nuclear localization. Arc/Arg3.1 overexpression decreased cell survival in response to heat shock. We conclude that Arc/Arg3.1 is transiently expressed after heat shock and negatively regulates HSF1 in the feedback loop of HSR.

Network-based integrated analysis of omics data reveal novel players of TGF-β1-induced EMT in human peritoneal mesothelial cells

Long-term peritoneal dialysis is associated with progressive fibrosis of the peritoneum. Epithelial-mesenchymal transition (EMT) of mesothelial cells is an important mechanism involved in peritoneal fibrosis, and TGF-β1 is considered central in this process. However, targeting currently known TGF-β1-associated pathways has not proven effective to date. Therefore, there are still gaps in understanding the mechanisms underlying TGF-β1-associated EMT and peritoneal fibrosis. We conducted network-based integrated analysis of transcriptomic and proteomic data to systemically characterize the molecular signature of TGF-β1-stimulated human peritoneal mesothelial cells (HPMCs). To increase the power of the data, multiple expression datasets of TGF-β1-stimulated human cells were employed, and extended based on a human functional gene network. Dense network sub-modules enriched with differentially expressed genes by TGF-β1 stimulation were prioritized and genes of interest were selected for functional analysis in HPMCs. Through integrated analysis, ECM constituents and oxidative stress-related genes were shown to be the top-ranked genes as expected. Among top-ranked sub-modules, TNFAIP6, ZC3H12A, and NNT were validated in HPMCs to be involved in regulation of E-cadherin, ZO-1, fibronectin, and αSMA expression. The present data shows the validity of network-based integrated analysis in discovery of novel players in TGF-β1-induced EMT in peritoneal mesothelial cells, which may serve as new prognostic markers and therapeutic targets for peritoneal dialysis patients.

Longitudinal Preterm Cerebellar Volume: Perinatal and Neurodevelopmental Outcome Associations

Impaired cerebellar development is an important determinant of adverse motor and cognitive outcomes in very preterm (VPT) infants. However, longitudinal MRI studies investigating cerebellar maturation from birth through childhood and associated neurodevelopmental outcomes are lacking. We aimed to compare cerebellar volume and growth from term-equivalent age (TEA) to 7 years between VPT (< 30 weeks' gestation or < 1250 g) and full-term children; and to assess the association between these measures, perinatal factors, and 7-year outcomes in VPT children, and whether these relationships varied by sex. In a prospective cohort study of 224 VPT and 46 full-term infants, cerebellar volumes were measured on MRI at TEA and 7 years. Useable data at either time-point were collected for 207 VPT and 43 full-term children. Cerebellar growth from TEA to 7 years was compared between VPT and full-term children. Associations with perinatal factors and 7-year outcomes were investigated in VPT children. VPT children had smaller TEA and 7-year volumes and reduced growth. Perinatal factors were associated with smaller cerebellar volume and growth between TEA and 7 years, namely, postnatal corticosteroids for TEA volume, and female sex, earlier birth gestation, white and deep nuclear gray matter injury for 7-year volume and growth. Smaller TEA and 7-year volumes, and reduced growth were associated with poorer 7-year IQ, language, and motor function, with differential relationships observed for male and female children. Our findings indicate that cerebellar growth from TEA to 7 years is impaired in VPT children and relates to early perinatal factors and 7-year outcomes.

Small molecule activator of Nm23/NDPK as an inhibitor of metastasis

Nm23-H1/NDPK-A is a tumor metastasis suppressor having NDP kinase (NDPK) activity. Nm23-H1 is positively associated with prolonged disease-free survival and good prognosis of cancer patients. Approaches to increasing the cellular levels of Nm23-H1 therefore have significance in the therapy of metastatic cancers. We found a small molecule, (±)-trans-3-(3,4-dimethoxyphenyl)-4-[(E)-3,4-dimethoxystyryl]cyclohex-1-ene, that activates Nm23, hereafter called NMac1. NMac1 directly binds to Nm23-H1 and increases its NDPK activity. Employing various NMac1 derivatives and hydrogen/deuterium mass spectrometry (HDX-MS), we identified the pharmacophore and mode of action of NMac1. We found that NMac1 binds to the C-terminal of Nm23-H1 and induces the NDPK activation through its allosteric conformational changes. NMac1-treated MDA-MB-231 breast cancer cells showed dramatic changes in morphology and actin-cytoskeletal organization following inhibition of Rac1 activation. NMac1 also suppressed invasion and migration in vitro, and metastasis in vivo, in a breast cancer mouse model. NMac1 as an activator of NDPK has potential as an anti-metastatic agent.

Tinnitus: A Stepchild in Our Specialty

Many patients are not satisfied with their doctor's answer when they complain about tinnitus. The proposed classification can be used to communicate with patients as well as guide future research. Type A itemizes the treatable causes of tinnitus. Type B itemizes tinnitus with a lack of medical explanation. Type C tinnitus is caused by diagnosable and treatable conditions, as listed in tinnitus type A, but the tinnitus persists after the successful treatment of the other symptoms.

Proteomic Analysis of Hippocampus in a Mouse Model of Depression Reveals Neuroprotective Function of Ubiquitin C-terminal Hydrolase L1 (UCH-L1) via Stress-induced Cysteine Oxidative Modifications

Chronic physical restraint stress increases oxidative stress in the brain, and dysregulation of oxidative stress can be one of the causes of major depressive disorder. To understand the underlying mechanisms, we undertook a systematic proteomic analysis of hippocampus in a chronic restraint stress mouse model of depression. Combining two-dimensional gel electrophoresis (2D-PAGE) for protein separation with nanoUPLC-ESI-q-TOF tandem mass spectrometry, we identified sixty-three protein spots that changed in the hippocampus of mice subjected to chronic restraint stress. We identified and classified the proteins that changed after chronic stress, into three groups respectively functioning in neural plasticity, metabolic processes and protein aggregation. Of these, 5 proteins including ubiquitin C-terminal hydrolase L1 (UCH-L1), dihydropyrimidinase-related protein 2 (DPYL2), haloacid dehalogenase-like hydrolase domain-containing protein 2 (HDHD2), actin-related protein 2/3 complex subunit 5 (ARPC5) and peroxiredoxin-2 (PRDX2), showed pI shifts attributable to post-translational modifications. Further analysis indicated that UCH-L1 underwent differential oxidations of 2 cysteine residues following chronic stress. We investigated whether the oxidized form of UCH-L1 plays a role in stressed hippocampus, by comparing the effects of UCH-L1 and its Cys mutants on hippocampal cell line HT-22 in response to oxidative stress. This study demonstrated that UCH-L1 wild-type and cysteine to aspartic acid mutants, but not its cysteine to serine mutants, afforded neuroprotective effects against oxidative stress; there were no discernible differences between wild-type UCH-L1 and its mutants in the absence of oxidative stress. These findings suggest that cysteine oxidative modifications of UCH-L1 in the hippocampus play key roles in neuroprotection against oxidative stress caused in major depressive disorder.

Postnatal Brain Growth Assessed by Sequential Cranial Ultrasonography in Infants Born <30 Weeks' Gestational Age

BACKGROUND AND PURPOSE

Brain growth in the early postnatal period following preterm birth has not been well described. This study of infants born at <30 weeks' gestational age and without major brain injury aimed to accomplish the following: 1) assess the reproducibility of linear measures made from cranial ultrasonography, 2) evaluate brain growth using sequential cranial ultrasonography linear measures from birth to term-equivalent age, and 3) explore perinatal predictors of postnatal brain growth.

MATERIALS AND METHODS

Participants comprised 144 infants born at <30 weeks' gestational age at a single center between January 2011 and December 2013. Infants with major brain injury seen on cranial ultrasonography or congenital or chromosomal abnormalities were excluded. Brain tissue and fluid spaces were measured from cranial ultrasonography performed as part of routine clinical care. Brain growth was assessed in 3 time intervals: <7, 7-27, and >27 days' postnatal age. Data were analyzed using intraclass correlation coefficients and mixed-effects regression.

RESULTS

A total of 429 scans were assessed for 144 infants. Several linear measures showed excellent reproducibility. All measures of brain tissue increased with postnatal age, except for the biparietal diameter, which decreased within the first postnatal week and increased thereafter. Gestational age of ≥28 weeks at birth was associated with slower growth of the biparietal diameter and ventricular width compared with gestational age of <28 weeks. Postnatal corticosteroid administration was associated with slower growth of the corpus callosum length, transcerebellar diameter, and vermis height. Sepsis and necrotizing enterocolitis were associated with slower growth of the transcerebellar diameter.

CONCLUSIONS

Postnatal brain growth in infants born at <30 weeks' gestational age can be evaluated using sequential linear measures made from routine cranial ultrasonography and is associated with perinatal predictors of long-term development.

Iris pigmented lesions as a marker of cutaneous melanoma risk: an Australian case-control study

BACKGROUND

Iris naevi and iris freckles have a frequency of 4% and 50% in the European population, respectively. They are associated with dysplastic naevi, but few studies have examined their link to cutaneous melanoma.

OBJECTIVES

To assess whether iris pigmented lesions are a predictive indicator for cutaneous melanoma.

METHODS

This is a melanoma case-control study of 1254 European-background Australians. Sun exposure and melanoma history, a saliva sample for DNA analysis and eye photographs taken with a digital camera were collected from 1117 participants. Iris images were assessed by up to four trained observers for the number of iris pigmented lesions. The data were analysed for correlations between iris pigmented lesions and melanoma history.

RESULTS

Case participants over the age of 40 had similar numbers of iris pigmented lesions to age matched controls (mean 5·7 vs. 5·2, P = 0·02), but in younger case and control participants there was a greater difference (mean 3·96 vs. 2·19, P = 0·004). A logistic regression adjusted for age, sex, skin, hair and eye colour, skin freckling and naevus count found that the presence of three or more iris pigmented lesions increases the melanoma risk 1·45-fold [95% confidence interval (CI) 1·07-1·95]. HERC2/OCA2 rs12913832 and IRF4 rs12203592 influenced both eye colour and the number of iris pigmented lesions. On the HERC2/OCA2 A/A and A/G genotype background there was an increasing proportion of blue eye colour when carrying the IRF4 T allele (P = 3 × 10^-4 ) and a higher number of iris pigmented lesions with the IRF4 T/T homozygote (P = 3 × 10^-9 ).

CONCLUSIONS

Iris pigmented lesion count provides additional predictive information for melanoma risk above that from conventional risk factors.

Adolescent mental health and behavioural predictors of being NEET: a prospective study of young adults not in employment, education, or training

BACKGROUND

Young adults who are not in employment, education, or training (NEET) are at risk of long-term economic disadvantage and social exclusion. Knowledge about risk factors for being NEET largely comes from cross-sectional studies of vulnerable individuals. Using data collected over a 10-year period, we examined adolescent predictors of being NEET in young adulthood.

METHODS

We used data on 1938 participants from the Victorian Adolescent Health Cohort Study, a community-based longitudinal study of adolescents in Victoria, Australia. Associations between common mental disorders, disruptive behaviour, cannabis use and drinking behaviour in adolescence, and NEET status at two waves of follow-up in young adulthood (mean ages of 20.7 and 24.1 years) were investigated using logistic regression, with generalised estimating equations used to account for the repeated outcome measure.

RESULTS

Overall, 8.5% of the participants were NEET at age 20.7 years and 8.2% at 24.1 years. After adjusting for potential confounders, we found evidence of increased risk of being NEET among frequent adolescent cannabis users [adjusted odds ratio (ORadj) = 1.74; 95% confidence interval (CI) 1.10-2.75] and those who reported repeated disruptive behaviours (ORadj = 1.71; 95% CI 1.15-2.55) or persistent common mental disorders in adolescence (ORadj = 1.60; 95% CI 1.07-2.40). Similar associations were present when participants with children were included in the same category as those in employment, education, or training.

CONCLUSIONS

Young people with an early onset of mental health and behavioural problems are at risk of failing to make the transition from school to employment. This finding reinforces the importance of integrated employment and mental health support programmes.

Nutritional status, exclusive breastfeeding and management of acute respiratory illness and diarrhea in the first 6 months of life in infants from two regions of Indonesia

BACKGROUND

Infant morbidity and mortality rates remain high in Indonesia, with acute respiratory illnesses (ARI) and diarrhea the leading two health problems in children under 5 years. We aimed to describe the nutritional status, feeding practice and case management of ARI and diarrhea of infants from two regions of Indonesia during the first 6 months of life.

METHODS

This study was an observational study conducted in parallel to an immunogenicity and efficacy trial of an oral rotavirus vaccine (RV3-BB) in the Klaten and Yogyakarta regions, Indonesia. Mothers were interviewed at 3 time points: within the first 6 days of their infant's life, and at 8-10 and 22-24 weeks of age. Questions asked included pregnancy history, infant nutritional status, feeding status and health of infants within up to 2 weeks prior to the assessment.

RESULTS

Between February 2013 and January 2014, 233 mother-infant pairs were recruited. 60% (136/223) of infants were exclusively breastfed (EBF) until 6 months of age with the strongest support for EBF reported by mothers themselves 70% (101/223) and 25% (36/223) from their partners. At 6 months, 6% (14/223) of infants were underweight and severely underweight; 4% (8/ 223) wasted and severely wasted; and 12% (28/223) were stunted and severely stunted. Non-recommended medication use was high, with 54% (21/39) of infants with reported cough within 2 weeks of an assessment receiving cough medication, 70% (27 /39) an antihistamine, 26% (10/39) a mucolytic and 15% (6 /39) an oral bronchodilator. At age 22-24 week, infants with reported diarrhea within 2 weeks of an assessment had low use of oral rehydration solutions (ORS) (3/21;14%) and zinc therapy (2/ 21;10%).

CONCLUSION

In this unique observational study, breastfeeding rates of 60% at 6 months were below the Indonesian national target of >75%. Adherence to WHO guidelines for management of ARI and diarrhea was poor, with high use of non-recommended cough medications and oral bronchodilators in the first 6 months of life and low use of ORS and zinc therapy. Ongoing education of primary health care workers and parents regarding management of common illness is needed in Indonesia.

Angiosome based time series analysis of deep tissue perfusion using diffuse speckle contrast analysis

An angiosome is a three dimensional volume of biological tissue which a specific artery governs. Although proven useful for vascular surgery, the direct relationship between arterial flow and microcirculation in specific angiosome remains controversial. Here, we present new optical approach, a four-channel diffuse speckle contrast analysis (DSCA) which can simultaneously measure blood perfusion at different foot area. Based on the hypothesis that same angiosome will support similar low frequency oscillation, we investigated cross-correlation among different DSCA channels. Our preliminary results show that the LFO signal from the channel closest to posterior tibial artery is leading the signal from the other channels.

The NO/cGMP pathway in duodenal motor, mechano- and chemosensory responses to acid: A randomized, placebo-controlled study with sildenafil in healthy volunteers

BACKGROUND

Altered duodenal sensorimotor responses to acid have been reported in a subset of patients with functional dyspepsia. To investigate whether NO is involved in these abnormalities, the effect of sildenafil (activates the NO pathway) on duodenal motor and sensory responses to acid in healthy humans was evaluated.

METHODS

A barostat-manometry catheter including an infusion tube was positioned in the duodenum of 12 healthy volunteers. Duodenal motility and dyspeptic symptoms were evaluated during the whole study. A first series of stepwise isobaric distensions was performed while participants scored their perception of upper abdominal sensations at the end of every distension step. Next, the duodenum was infused with sildenafil 50 mg or saline, followed by duodenal acid infusion. During duodenal acidification, a second sequence of stepwise isobaric distensions with the assessment of sensations was repeated.

KEY RESULTS

Acid infusion did not induce dyspeptic symptoms with both placebo and sildenafil pretreatment. Duodenal motility decreased after sildenafil infusion, whereas it was not affected by placebo. Acid-induced increase in motility was, however, observed in both conditions, and no difference between the conditions was found. Duodenal acidification decreased thresholds for discomfort and increased perception scores during duodenal distensions in both groups, but again no difference was observed between placebo and sildenafil pretreatment.

CONCLUSIONS AND INFERENCES

Sildenafil does not affect duodenal motor, mechanosensory, and chemosensory responses to acid in healthy controls. Therefore, it is less likely that the NO pathway plays a role in the altered response to acid in functional dyspepsia patients.

Calcium Ion Induced Structural Changes Promote Dimerization of Secretagogin, Which Is Required for Its Insulin Secretory Function

Secretagogin (SCGN), a hexa EF-hand calcium binding protein, plays key roles in insulin secretion in pancreatic β-cells. It is not yet understood how the binding of Ca²⁺ to human SCGN (hSCGN) promotes secretion. Here we have addressed this question, using mass spectrometry combined with a disulfide searching algorithm DBond. We found that the binding of Ca²⁺ to hSCGN promotes the dimerization of hSCGN via the formation of a Cys193-Cys193 disulfide bond. Hydrogen/deuterium exchange mass spectrometry (HDX-MS) and molecular dynamics studies revealed that Ca²⁺ binding to the EF-hands of hSCGN induces significant structural changes that affect the solvent exposure of N-terminal region, and hence the redox sensitivity of the Cys193 residue. These redox sensitivity changes were confirmed using biotinylated methyl-3-nitro-4-(piperidin-1-ylsulfonyl) benzoate (NPSB-B), a chemical probe that specifically labels reactive cysteine sulfhydryls. Furthermore, we found that wild type hSCGN overexpression promotes insulin secretion in pancreatic β cells, while C193S-hSCGN inhibits it. These findings suggest that insulin secretion in pancreatic cells is regulated by Ca²⁺ and ROS signaling through Ca²⁺-induced structural changes promoting dimerization of hSCGN.

Heterogeneous nuclear ribonucleoprotein K inhibits heat shock-induced transcriptional activity of heat shock factor 1

When cells are exposed to heat shock and various other stresses, heat shock factor 1 (HSF1) is activated, and the heat shock response (HSR) is elicited. To better understand the molecular regulation of the HSR, we used 2D-PAGE-based proteome analysis to screen for heat shock-induced post-translationally modified cellular proteins. Our analysis revealed that two protein spots typically present on 2D-PAGE gels and containing heterogeneous nuclear ribonucleoprotein K (hnRNP K) with trioxidized Cys¹³² disappeared after the heat shock treatment and reappeared during recovery, but the total amount of hnRNP K protein remained unchanged. We next tested whether hnRNP K plays a role in HSR by regulating HSF1 and found that hnRNP K inhibits HSF1 activity, resulting in reduced expression of hsp70 and hsp27 mRNAs. hnRNP K also reduced binding affinity of HSF1 to the heat shock element by directly interacting with HSF1 but did not affect HSF1 phosphorylation-dependent activation or nuclear localization. hnRNP K lost its ability to induce these effects when its Cys¹³² was substituted with Ser, Asp, or Glu. These findings suggest that hnRNP K inhibits transcriptional activity of HSF1 by inhibiting its binding to heat shock element and that the oxidation status of Cys¹³² in hnRNP K is critical for this inhibition.

Genome-wide expression analysis of a rice mutant line under salt stress

Salinity is a major environmental stress to plants. In this study, the ability of plants to tolerate salt was investigated by studying growth, physiological characteristics, and expression levels of genes related to the salt-stress response in the salt-tolerant rice mutant (Till-II-877), which was derived from γ-ray irradiation. Compared to plants grown under normal conditions, the height and root length of wild type (WT) were reduced by approximately 40 and 29% following exposure to salt stress for 3 weeks, whereas Till-II-877 line showed 29 and 23% reductions in plant height and root length, respectively. No significant changes were observed in total chlorophyll content, and the malondialdehyde content of the mutant increased less than that of the WT under salt treatment. Gene expression was compared between the WT and mutant lines using microarray analysis. An unbiased analysis of the gene expression datasets allowed us to identify the pathways involved in salt-stress responses. Among the most significantly affected pathways, changes in gene expression were observed in α-linolenic acid and linoleic acid metabolism (in lipid metabolism), fructose and mannose metabolism and glycolysis-gluconeogenesis (in carbohydrate metabolism), cysteine and methionine metabolism (in amino acid metabolism), and carbon fixation (in the energy metabolism of photosynthetic organisms) under salt stress. These results show that the differential response of plants subjected to salt stress was due to changes in multiple metabolic pathways. These findings increase our understanding of the effects of salt stress in rice and may aid in the development of salt-tolerant rice cultivars.

ARD1-mediated Hsp70 acetylation balances stress-induced protein refolding and degradation

Heat shock protein (Hsp)70 is a molecular chaperone that maintains protein homoeostasis during cellular stress through two opposing mechanisms: protein refolding and degradation. However, the mechanisms by which Hsp70 balances these opposing functions under stress conditions remain unknown. Here, we demonstrate that Hsp70 preferentially facilitates protein refolding after stress, gradually switching to protein degradation via a mechanism dependent on ARD1-mediated Hsp70 acetylation. During the early stress response, Hsp70 is immediately acetylated by ARD1 at K77, and the acetylated Hsp70 binds to the co-chaperone Hop to allow protein refolding. Thereafter, Hsp70 is deacetylated and binds to the ubiquitin ligase protein CHIP to complete protein degradation during later stages. This switch is required for the maintenance of protein homoeostasis and ultimately rescues cells from stress-induced cell death in vitro and in vivo. Therefore, ARD1-mediated Hsp70 acetylation is a regulatory mechanism that temporally balances protein refolding/degradation in response to stress.

The chaperone Hsp70 has a dual role, promoting both protein refolding and protein degradation. Seo and Park et al. show that Hsp70 acetylation enhances protein refolding after stress, and that subsequent deacetylation progressively promotes ubiquitin ligase binding and protein degradation.

Electronic energy and electron transfer processes in photoexcited donor-acceptor dyad and triad molecular systems based on triphenylene and perylene diimide units

We investigate the photophysical properties of organic donor-acceptor dyad and triad molecular systems based on triphenylene and perylene diimide units linked by a non-conjugated flexible bridge in solution using complementary optical spectroscopy techniques. When these molecules are diluted in dichloromethane solution, energy transfer from the triphenylene to the perylene diimide excited moieties is evidenced by time-resolved fluorescence measurements resulting in a quenching of the emission from the triphenylene moieties. Simultaneously, another quenching process that affects the emission from both donor and acceptor units is observed. Solution ultrafast transient absorption measurements provide evidence of photo-induced charge transfer from either the donor or the acceptor depending upon the excitation. Overall, the analysis of the detailed time-resolved spectroscopic measurements carried out in the dyad and triad systems as well as in the triphenylene and perylene diimide units alone provides useful information both to better understand the relations between energy and charge transfer processes with molecular structures, and for the design of future functional dyad and triad architectures based on donor and acceptor moieties for organic optoelectronic applications.

Mechanistic elucidation guided by covalent inhibitors for the development of anti-diabetic PPARγ ligands

Peroxisome proliferator-activated receptor gamma (PPARγ) is a ligand-regulated transcription factor that plays crucial roles in adipogenesis, lipid metabolism, and glucose homeostasis. Several PPARγ ligands possess anti-diabetic activity and they commonly inhibit the phosphorylation of PPARγ at serine 273 (Ser273). The recently reported PPARγ ligand SR1664, which selectively blocks the phosphorylation of PPARγ without classical agonism, has potent anti-diabetic activity, indicating that the inhibition of Ser273 phosphorylation is sufficient to provoke anti-diabetic effects. In this study, we revealed the X-ray structure of PPARγ co-crystallized with SR1664 bound to the alternate binding site of PPARγ and confirmed that the alternate site binding of SR1664 blocks the phosphorylation of Ser273. Furthermore, using covalent inhibitors as chemical tools, we demonstrated that the inhibition of phosphorylation is attributed to the occupation of a specific site which is a hydrophobic region between helix 3 and β3-β4 at the binding pocket of PPARγ. In high-fat diet-induced obese mice, we confirmed the anti-diabetic activity of our covalent inhibitor SB1453 that was designed to bind at the specific site in PPARγ for blocking the phosphorylation of Ser273. Lastly, the target selectivity of SB1453 was demonstrated by fluorescence-based visualization of target proteins complexed with the covalent probe 11 containing a bioorthogonal functional group.

Ubiquitin C-terminal hydrolase-L1 increases cancer cell invasion by modulating hydrogen peroxide generated via NADPH oxidase 4

This study explored the role of ubiquitin C-terminal hydrolase-L1 (UCH-L1) in the production of ROS and tumor invasion. UCH-L1 was found to increase cellular ROS levels and promote cell invasion. Silencing UCH-L1, as well as inhibition of H₂O₂ generation by catalase or by DPI, a NOX inhibitor, suppressed the migration potential of B16F10 cells, indicating that UCH-L1 promotes cell migration by up-regulating H₂O₂ generation. Silencing NOX4, which generates H₂O₂, with siRNA eliminated the effect of UCH-L1 on cell migration. On the other hand, NOX4 overexpressed in HeLa cells happens to be ubiquitinated, and NOX4 following deubiquitination by UCH-L1, restored H₂O₂-generating activity. These in vitro findings are consistent with the results obtained in vivo with catalase (−/−) C57BL/6J mice. When H₂O₂ and UCH-L1 levels were independently varied in these animals, the former by infecting with H₂O₂-scavenging adenovirus-catalase, and the latter by overexpressing or silencing UCH-L1, pulmonary metastasis of B16F10 cells overexpressing UCH-L1 increased significantly in catalase (−/−) mice. In contrast, invasion did not increase when UCH-L1 was silenced in the B16F10 cells. These findings indicate that H₂O₂ levels regulated by UCH-L1 are necessary for cell invasion to occur and demonstrate that UCH-L1 promotes cell invasion by up-regulating H₂O₂ via deubiquitination of NOX4.

Simvastatin inhibits the expression of inflammatory cytokines and cell adhesion molecules induced by LPS in human dental pulp cells

AIM

To investigate the effect of simvastatin on lipopolysaccharide (LPS)-stimulated inflammatory cytokines, cell adhesion molecules and nuclear factor-κB (NF-κB) transcription factors in human dental pulp cells (HDPCs).

METHODOLOGY

The effect of LPS and simvastatin on human dental pulp cell (HDPCs) viability was measured using a 3-[4, 5-dimethylthiazol-2-yl]-2, 5 diphenyltetrazolium bromide (MTT) assay. The expression of inflammatory cytokines and cell adhesion molecules was evaluated by reverse-transcription polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay (ELISA) and Western blot analysis. NF-κB transcription factors were evaluated by Western blot analysis. Statistical analysis was performed with analysis of variance (anova).

RESULTS

The viability of cells exposed to different concentrations of E. coli LPS, P. gingivalis LPS and simvastatin was not significantly different compared with that of control cells (P > 0.05). LPS significantly increased interleukin (IL)-1β (P < 0.05) and IL-6 mRNA expression (P < 0.05) and vascular cell adhesion molecule-1 (VCAM-1) (P < 0.05) and intercellular adhesion molecule-1 (ICAM-1) protein expression (P < 0.05) in HDPCs. Treatment with simvastatin significantly attenuated LPS-stimulated production of IL-1β, IL-6, VCAM-1 and ICAM-1 (P < 0.05). Treatment with simvastatin decreased LPS-induced expression of p65 and phosphorylation of IκB and also significantly decreased the phosphorylation of p65 and IκB in the cytoplasm and the level of p65 in the nucleus (P < 0.05).

CONCLUSIONS

Simvastatin has a suppressing effect on LPS-induced inflammatory cytokine, cell adhesion molecules and NF-κB transcription factors in HDPCs. Therefore, simvastatin might be a useful candidate as a pulp-capping agent in vital pulp therapy.

Heritability of naevus patterns in an adult twin cohort from the Brisbane Twin Registry: a cross-sectional study

BACKGROUND

Heritability of naevi counts is widely acknowledged as a potential surveillance parameter for prevention purposes. The contribution of heritability to the changes seen in naevus number and morphology over time and their corresponding dermoscopic characteristics is unknown, but is important to understand in order to account for adequate prevention measures.

OBJECTIVES

To identify naevus characteristics that are strongly influenced by heritability.

METHODS

This cross-sectional study included 220 individuals [76 monozygotic (MZ), 144 dizygotic (DZ)], recruited from the Brisbane Twin Naevus Study. Participants received full body imaging and dermoscopy of naevi ≥ 5 mm in diameter. Dermoscopic type, total naevus count (TNC), change in TNC with age, and naevus distribution, size, colour and profile were compared between MZ and DZ twins. Heritability of these traits was assessed via Falconer's estimate.

RESULTS

Significant differences were found in comparing MZ and DZ twins for TNC, numbers of naevi 5·0-7·9 mm in diameter, counts of light-brown naevi, naevi on the back and sun-protected sites, and naevi with the 'nonspecific' dermoscopic pattern.

CONCLUSIONS

This study strongly supports a heritable component to TNC, as well as changes in TNC, and the number of medium-sized naevi, light-brown naevi, specific sites and certain dermoscopic features in adults. These characteristics should be taken into account by naevus surveillance programmes and further studied to identify candidate gene associations for clinical and dermoscopic patterns in conjunction with melanoma risk stratification.

Mapping homeostatic synaptic plasticity using cable properties of dendrites

When chronically silenced, cortical and hippocampal neurons homeostatically upregulate excitatory synaptic function. However, the subcellular position of such changes on the dendritic tree is not clear. We exploited the cable-filtering properties of dendrites to derive a parameter, the dendritic filtering index (DFI), to map the spatial distribution of synaptic currents. Our analysis indicates that young rat cortical neurons globally scale AMPA receptor-mediated currents, while mature hippocampal neurons do not, revealing distinct homeostatic strategies between brain regions and developmental stages. The DFI presents a useful tool for mapping the dendritic origin of synaptic currents and the location of synaptic plasticity changes.

Reducing and preventing internalizing and externalizing behavior problems in children with type 1 diabetes: a randomized controlled trial of the Triple P-Positive Parenting Program

BACKGROUND

Children with type 1 diabetes are at increased risk of mental health problems, which in turn are associated with poor glycemic control, diabetes-related complications, and long-term psychiatric morbidity. We tested the efficacy of the Triple P-Positive Parenting Program in reducing or preventing mental health problems and improving glycemic control in children with type 1 diabetes in a randomized controlled trial.

METHODS

Participants were recruited from the Diabetes Clinic, Royal Children's Hospital, Melbourne, Australia, and randomized to Triple P or standard diabetes care. The primary outcome was child internalizing and externalizing behavior problems 3 and 12 months postrandomization. Secondary outcomes were glycemic control, parent mental health, parenting skills, and family functioning at 3 and 12 months, and glycemic control at 24 months.

RESULTS

A total of 76 participants were randomized (38 to intervention and 38 to control), 60 completed 3-month, and 57 completed 12-month assessments. Benefits of Triple P were evident at 3 months for parent mental health, parenting skills, and family functioning (p < 0.05), but not for child mental health or glycemic control, with little effect at 12 months. Prespecified subgroup analyses for children with pre-existing internalizing or externalizing behavior problems indicated greater improvements in child mental health, parent mental health, parenting skills, and diabetes family conflict (p < 0.05), but lower parenting self-efficacy at 3 months. Improvements in parent mental health and parenting competency associated with Triple P were sustained to 12 months for children with pre-existing mental health problems.

CONCLUSIONS

This study provides some support for the efficacy of Triple P in improving parent and family outcomes, and reducing child internalizing and externalizing behavior problems primarily in children who have pre-existing mental health problems.

A high burden of late-onset sepsis among newborns admitted to the largest neonatal unit in central Vietnam

OBJECTIVE

The objective of this study is to determine the prevalence, causes and outcome of sepsis in hospitalized neonates in the largest neonatal unit in central Vietnam.

STUDY DESIGN

A 1-year prospective cohort study of newborns admitted to the neonatal unit in Da Nang. A sepsis work-up including blood culture was undertaken before commencing antibiotics for neonates with suspected sepsis.

RESULT

Of 2555 neonatal admissions, 616 neonates had 729 episodes of suspected invasive sepsis. A pathogen was isolated from blood in 115 (16%) episodes in 106 neonates. The prevalence of early-onset sepsis (EOS) was 8 (95% confidence interval (CI): 4 to 11) per 1000 admissions, and of late-onset sepsis (LOS) was 34 (95% CI: 27 to 41) per 1000 admissions. Of 86 neonates with LOS, 69 (80%) also fulfilled the criteria for nosocomial sepsis. The commonest bacterial causes of EOS were coagulase-negative Staphylococcus (CoNS) and Staphylococcus aureus, and of LOS were Acinetobacter, CoNS and Klebsiella pneumoniae. Fungal sepsis occurred in 35 neonates of which most were nosocomial sepsis. In vitro resistance to multiple antibiotics was common among Gram-negative bacteria. Antibiotics were prescribed and given to 68% of all admissions, and 14% of all admissions received four or more different antibiotics. The case fatality rate for confirmed sepsis was 46%.

CONCLUSION

Late-onset, nosocomial sepsis was common and associated with a high mortality in hospitalized newborns in the largest neonatal unit in central Vietnam. These findings highlighted the need for improved infection control measures and antibiotic stewardship, which have since been implemented.

Neural stem cell transplantation at critical period improves learning and memory through restoring synaptic impairment in Alzheimer's disease mouse model

Alzheimer's disease (AD) is characterized by neuronal loss in several regions of the brain. Recent studies have suggested that stem cell transplantation could serve as a potential therapeutic strategy to halt or ameliorate the inexorable disease progression. However, the optimal stage of the disease for stem cell transplantation to have a therapeutic effect has yet to be determined. Here, we demonstrated that transplantation of neural stem cells into 12-month-old Tg2576 brains markedly improved both cognitive impairments and neuropathological features by reducing β-amyloid processing and upregulating clearance of β-amyloid, secretion of anti-inflammatory cytokines, endogenous neurogenesis, as well as synapse formation. In contrast, the stem cell transplantation did not recover cognitive dysfunction and β-amyloid neuropathology in Tg2576 mice aged 15 months when the memory loss is manifest. Overall, this study underscores that stem cell therapy at optimal time frame is crucial to obtain maximal therapeutic effects that can restore functional deficits or stop the progression of AD.

Efficacy of combination therapy with probiotics and mosapride in patients with IBS without diarrhea: a randomized, double-blind, placebo-controlled, multicenter, phase II trial

BACKGROUND

Probiotics can be beneficial in irritable bowel syndrome (IBS). Mosapride citrate, a selective 5-HT4 receptor agonist, stimulates gastrointestinal motility. We investigated the efficacy of combination therapy with probiotics and mosapride for non-diarrheal-type IBS.

METHODS

Two hundred and eighty-five IBS patients were randomly assigned to either a combination of probiotics (Bacillus subtilis and Streptococcus faecium) and mosapride at one of four different doses or a placebo for 4 weeks. The primary outcome was the proportion of patients experiencing adequate relief (AR) of global IBS symptoms at week 4. The secondary outcomes included subject's global assessment (SGA) of IBS symptom relief, individual symptoms, stool parameters, and IBS-quality of life.

KEY RESULTS

The proportion of AR at week 4 was significantly higher in all treatment groups compared to the placebo group (53.7% in group 1, 55.0% in group 2, 55.2% in group 3, 53.6% in group 4 [the highest dose], and 35.1% in placebo group, respectively, p < 0.05). The proportion of patients reporting 'completely or considerably relieved' in the SGA was higher in the treatment groups than in the placebo group. The abdominal pain/discomfort score in the treatment group 4 was more prominently improved compared with that of the placebo group. In patients with constipation-predominant IBS, the improvements in stool frequency and consistency were significantly higher in the treatment groups 4 and 1, respectively, than those in the placebo group.

CONCLUSIONS & INFERENCES

Combination therapy with probiotics and mosapride is effective for relief of symptoms in patients with non-diarrheal-type IBS. The study has been registered in the US National Library of Medicine (http://www.clinicaltrials.gov, NCT01505777).

Proteomic analysis of INS-1 rat insulinoma cells: ER stress effects and the protective role of exenatide, a GLP-1 receptor agonist

Beta cell death caused by endoplasmic reticulum (ER) stress is a key factor aggravating type 2 diabetes. Exenatide, a glucagon-like peptide (GLP)-1 receptor agonist, prevents beta cell death induced by thapsigargin, a selective inhibitor of ER calcium storage. Here, we report on our proteomic studies designed to elucidate the underlying mechanisms. We conducted comparative proteomic analyses of cellular protein profiles during thapsigargin-induced cell death in the absence and presence of exenatide in INS-1 rat insulinoma cells. Thapsigargin altered cellular proteins involved in metabolic processes and protein folding, whose alterations were variably modified by exenatide treatment. We categorized the proteins with thapsigargin initiated alterations into three groups: those whose alterations were 1) reversed by exenatide, 2) exaggerated by exenatide, and 3) unchanged by exenatide. The most significant effect of thapsigargin on INS-1 cells relevant to their apoptosis was the appearance of newly modified spots of heat shock proteins, thimet oligopeptidase and 14-3-3β, ε, and θ, and the prevention of their appearance by exenatide, suggesting that these proteins play major roles. We also found that various modifications in 14-3-3 isoforms, which precede their appearance and promote INS-1 cell death. This study provides insights into the mechanisms in ER stress-caused INS-1 cell death and its prevention by exenatide.

Hydrogen-deuterium exchange mass spectrometry for determining protein structural changes in drug discovery

Protein structures are dynamically changed in response to post-translational modifications, ligand or chemical binding, or protein-protein interactions. Understanding the structural changes that occur in proteins in response to potential candidate drugs is important for predicting the modes of action of drugs and their functions and regulations. Recent advances in hydrogen/deuterium exchange mass spectrometry (HDX-MS) have the potential to offer a tool for obtaining such understanding similarly to other biophysical techniques, such as X-ray crystallography and high resolution NMR. We present here, a review of basic concept and methodology of HDX-MS, how it is being applied for identifying the sites and structural changes in proteins following their interactions with other proteins and small molecules, and the potential of this tool to help in drug discovery.