Activation of NFAT by HGF and IGF-1 via ARF6 and its effector ASAP1 promotes uveal melanoma metastasis

Preventing or effectively treating metastatic uveal melanoma (UM) is critical because it occurs in about half of patients and confers a very poor prognosis. There is emerging evidence that hepatocyte growth factor (HGF) and insulin-like growth factor 1 (IGF-1) promote metastasis and contribute to the striking metastatic hepatotropism observed in UM metastasis. However, the molecular mechanisms by which HGF and IGF-1 promote UM liver metastasis have not been elucidated. ASAP1, which acts as an effector for the small GTPase ARF6, is highly expressed in the subset of uveal melanomas most likely to metastasize. Here, we found that HGF and IGF-1 hyperactivate ARF6, leading to its interaction with ASAP1, which then acts as an effector to induce nuclear localization and transcriptional activity of NFAT1. Inhibition of any component of this pathway impairs cellular invasiveness. Additionally, knocking down ASAP1 or inhibiting NFAT signaling reduces metastasis in a xenograft mouse model of UM. The discovery of this signaling pathway represents not only an advancement in our understanding of the biology of uveal melanoma metastasis but also identifies a novel pathway that could be targeted to treat or prevent metastatic uveal melanoma.

Significance of photodocumentation-associated factors in colonoscopy on the detection rate of colorectal neoplasms

OBJECTIVE

It is unclear whether photodocumentation is associated with colorectal neoplasm (CRN) detection at colonoscopy, despite its ability to take more images with the development of affordable digital imaging systems. This study aimed to investigate whether photodocumentation-related factors could affect the detection rate of CRNs in healthy subjects.

PATIENTS AND METHODS

A total of 2,637 subjects undergoing screening colonoscopy in routine health check-ups at CHA Bundang Medical from January to September 2016 were enrolled in this study. Only the endoscopic image data for observation purposes during colonoscopy withdrawal was used in this analysis. The number of observation images, observation time and the speed of photodocumentation (SPD) defined as the number of observation images per minute were used as quantity measures of photodocumentation. The presence of documented anatomical landmarks such as appendix orifice (AO), ileocecal valve (ICV), anorectal junction was used as quality measures of photodocumentation.

RESULTS

Among subject-related factors, the independent factors for CRN detection in the multivariate analysis were age, male sex, waist circumference, and family history of colorectal cancer. In photo-documentation-related factors, SPD [Odds ratio (OR) 0.800; 95% confidence interval (CI), 0.740 to 0.864], observation time over 6 min (OR 1.671; 95% CI, 1.145 to 2.439), clear documentation of appendix orifice (AO) (OR 5.976; 95% CI, 4.548 to 7.852) and ileocecal valve (ICV) (OR 3.826; 95% CI, 2.985 to 4.904), and endoscopists (p < 0.001) were independently significant factors. However, the number of observation images was not associated with the detection of CRNs.

CONCLUSIONS

Lower SPD and clear documentation of cecal landmarks might be associated with an increased detection rate of CRNs.

Atomic-scale interpretation of the quantum oscillations in cuprate superconductors

Cuprate superconductors display unusual features in bothkspace and real space as the superconductivity is suppressed-a broken Fermi surface, charge density wave, and pseudogap. Contrarily, recent transport measurements on cuprates under high magnetic fields report quantum oscillations (QOs), which imply rather a usual Fermi liquid behavior. To settle the disagreement, we investigated Bi₂Sr₂CaCu₂O_8+δunder a magnetic field in an atomic scale. A particle-hole (p-h) asymmetrically dispersing density of states (DOSs) modulation was found at the vortices on a slightly underdoped sample, while on a highly underdoped sample, no trace of the vortex was found even at 13 T. However, a similar p-h asymmetric DOS modulation persisted in almost an entire field of view. From this observation, we infer an alternative explanation of the QO results by providing a unifying picture where the aforementioned seemingly conflicting evidence from angle-resolved photoemission spectroscopy, spectroscopic imaging scanning tunneling microscopy, and magneto-transport measurements can be understood solely in terms of the DOS modulations.

Type I Interferon Signaling Is Critical During the Innate Immune Response to HSV-1 Retinal Infection

Purpose

Acute retinal necrosis (ARN) is a herpesvirus infection of the retina with blinding complications. In this study, we sought to create a reproducible mouse model of ARN that mimics human disease to better understand innate immunity within the retina during virus infection.

Methods

C57Bl/6J wild type (WT) and type I interferon receptor-deficient (IFNAR-/-) mice were infected with varying amounts of herpes simplex virus type 1 (HSV-1) via subretinal injection. Viral titers, optical coherence tomography (OCT) and fundus photography, the development of encephalitis, and ocular histopathology were scored and compared between groups of WT and IFNAR-/- mice.

Results

The retina of WT mice could be readily infected with HSV-1 via subretinal injection resulting in retinal whitening and full-thickness necrosis as determined by in vivo imaging and histopathology. In IFNAR-/- mice, HSV-1-induced retinal pathology was significantly worse when compared with WT mice, and viral titers were significantly elevated within two days after infection and persisted to day 5 after infection within the retina. These results were also observed in the brain where there were significantly higher viral titers and frequency of encephalitis in IFNAR-/- when compared to WT mice.

Conclusions

Collectively, these findings show that our new mouse model of ARN mimics human disease and can be used to study innate immunity within the retina. We conclude that type I interferons are critical in containing HSV-1 locally within retinal tissues and prohibiting spread into the brain.

Probing Gluon Spin-Momentum Correlations in Transversely Polarized Protons through Midrapidity Isolated Direct Photons in p^{↑}+p Collisions at sqrt[s]=200 GeV

Studying spin-momentum correlations in hadronic collisions offers a glimpse into a three-dimensional picture of proton structure. The transverse single-spin asymmetry for midrapidity isolated direct photons in p^{↑}+p collisions at sqrt[s]=200  GeV is measured with the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC). Because direct photons in particular are produced from the hard scattering and do not interact via the strong force, this measurement is a clean probe of initial-state spin-momentum correlations inside the proton and is in particular sensitive to gluon interference effects within the proton. This is the first time direct photons have been used as a probe of spin-momentum correlations at RHIC. The uncertainties on the results are a 50-fold improvement with respect to those of the one prior measurement for the same observable, from the Fermilab E704 experiment. These results constrain gluon spin-momentum correlations in transversely polarized protons.

Chloroquine Sensitizes GNAQ/11-mutated Melanoma to MEK1/2 Inhibition

PURPOSE

Mutational activation of GNAQ or GNA11 (GNAQ/11), detected in >90% of uveal melanomas, leads to constitutive activation of oncogenic pathways, including MAPK and YAP. To date, chemo- or pathway-targeted therapies, either alone or in combination, have proven ineffective in the treatment of patients with metastatic uveal melanoma.

EXPERIMENTAL DESIGN

We tested the efficacy of chloroquine or hydroxychloroquine, in combination with MAPK pathway inhibition in GNAQ/11-mutated cells in vitro and in vivo and identified mechanisms of MEK1/2 inhibitor plus chloroquine-induced cytotoxicity.

RESULTS

Inhibition of GNAQ/11-mediated activation of MAPK signaling resulted in the induction of autophagy. Combined inhibition of Gα and autophagy or lysosome function resulted in enhanced cell death. Moreover, the combination of MEK1/2 inhibition, using trametinib, with the lysosome inhibitor, chloroquine, also increased cytotoxicity. Treatment of mice bearing GNAQ/11-driven melanomas with trametinib plus hydroxychloroquine resulted in inhibition of tumor growth and significantly prolonged survival. Interestingly, lysosomal- and autophagy-specific inhibition with bafilomycin A1 was not sufficient to promote cytotoxicity in combination with trametinib. However, the addition of YAP inhibition with trametinib plus bafilomycin A1 resulted in cell death at comparable levels to trametinib plus chloroquine (T/CQ) treatment. Furthermore, T/CQ-treated cells displayed decreased YAP nuclear localization and decreased YAP transcriptional activity. Expression of a constitutively active YAP^5SA mutant conferred resistance to T/CQ-induced cell death.

CONCLUSIONS

These results suggest that YAP, MEK1/2, and lysosome function are necessary and critical targets for the therapy of GNAQ/11-driven melanoma, and identify trametinib plus hydroxychloroquine as a potential treatment strategy for metastatic uveal melanoma.

Abstract 1890: Chloroquine synergizes with MEK1/2 targeted therapy through dual YAP and lysosomal inhibition in GNAQ/11 mutant uveal melanoma

GNAQ and GNA11 (GNAQ/11) mutations are found in less than 2% of all melanoma, but more than 80% of uveal melanoma. Mutations in these Gα proteins lead to constitutive activation of multiple oncogenic pathways, including MAPK (RAF-&gt;MEK1/2-&gt;ERK1/2) and YAP signaling. Metastatic uveal melanoma is refractory to all forms of pharmacologic treatment, such as FDA-approved targeted therapies inhibiting MEK1/2 (i.e. trametinib and binimetinib). We show that combining MEK1/2 inhibitors with 4-aminoquinoline antimalarials, chloroquine or hydroxychloroquine, resulted in synergistic and apoptosis-mediated cytotoxicity in GNAQ/11 mutant uveal melanoma cell lines. Interestingly, in contrast to our previous work in pancreatic and other RAS-driven cancers, the lysosomotropic role of chloroquine was not sufficient to promote cytotoxicity with MEK1/2 inhibitors, as neither lysosome inhibition with Bafilomycin A1 nor autophagy-specific and macropinocytosis-specific inhibition yielded enhanced cell death in combination with MEK1/2 inhibition. We then found that chloroquine prevented nuclear localization of the transcriptional coactivator, YAP, suggesting a novel mechanism of chloroquine. YAP inhibition combined with MEK1/2 inhibition enhanced cell death only in the presence of Bafilomycin A1. Gα-specific inhibition (inhibiting YAP and MAPK) combined with Bafilomycin A1 yielded similar results. This implies that the ability of chloroquine to inhibit both YAP signaling and lysosome function is required for promoting cell death in the presence of MEK1/2 inhibition. For in vivostudies, we utilized a hepatic colonization model using luciferized human metastatic uveal melanoma cell lines, OMM2.5 and OMM1. Daily treatment of trametinib with hydroxychloroquine in combination resulted in delayed tumor growth and increased overall survival compared to either treatment as monotherapy or chemotherapy. These findings were also recapitulated in an immunocompetent mouse model in which immortalized mouse melanocytes (Melan-A) with either a GNAQ or GNA11 activating mutation were implanted into syngeneic C57BL/6 mice. Our findings identify a novel mechanism of chloroquine and suggest a potentially effective strategy combining two FDA-approved drugs for the treatment of metastatic uveal melanoma.

Citation Format: Amanda Truong, Michael Scherzer, Conan Kinsey, John Michael Sanchez, Jae Hyuk Yoo, Jackson Richards, Donghan Shin, Phaedra Ghazi, Michael Onken, Kendall Blumer, Shannon Odelberg, Martin McMahon. Chloroquine synergizes with MEK1/2 targeted therapy through dual YAP and lysosomal inhibition in GNAQ/11 mutant uveal melanoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1890.

Abstract 6078: Suppression of tumor-intrinsic IFNγ signaling in ARF6-mediated metastatic progression of melanoma

ARF6 is a small GTPase that controls the subcellular location of proteins to regulate invasion, proliferation and tumor microvesicle shedding. ARF6 is aberrantly activated in cutaneous melanoma and stimulates invasion in BRAFV600E-melanoma by controlling localization and activation of beta-catenin and PI3K/AKT. In uveal melanoma, ARF6 facilitates GNAQQ209L signaling to drive tumor growth by trafficking GNAQ to cytoplasmic vesicles. Although distinct diseases, pharmacologic inhibition of ARF6 reduces disease progression in both uveal and cutaneous melanoma models. These data underscore the importance of intracellular trafficking mechanisms in cancer and highlight the potential clinical utility of targeting this machinery by inhibiting ARF6. In order to genetically dissect the role of ARF6 in melanomagenesis, we utilized RCAS-mediated delivery of Cre recombinase, with or without constitutively activated ARF6 (Arf6Q67L), specifically to melanocytic cells to induce constitutive activation of BRAFV600E (BrafCA), deletion of Cdkn2a (Cdkn2af/f) and (Arf6f/f). Activation of ARF6 accelerates spontaneous metastasis while loss of Arf6 delays tumor onset and reduces tumor incidence and growth, dramatically improving survival of BrafCA;Cdkn2af/f mice, including in the presence of Pten loss. Unexpectedly, tumors expressing ARF6Q67L show significantly reduced expression of interferon-gamma (IFNγ) response genes, reduced CD8 (T cell) transcripts and an anti-apoptotic proteomics profile. Knockdown of Arf6 sensitizes BRAFV600E melanoma cells to IFNγ treatment reducing cell viability in vitro. Together these data demonstrate that ARF6 modulates BRAFV600E-driven tumor progression and suggest that ARF6 activation suppresses tumor intrinsic IFNγ signaling to evade the anti-tumor immune response during metastatic progression. Our in vivo models provide a new paradigm for understanding vulnerabilities in BRAF-mediated oncogenesis and implicate intracellular trafficking mechanisms as potentially actionable machinery in melanoma development, immune evasion and disease progression.

Citation Format: Coulson P. Rich, Aaron Rogers, Jae Hyuk Yoo, Roger Wolff, Shannon J. Odelberg, Sheri L. Holmen, Allie H. Grossmann. Suppression of tumor-intrinsic IFNγ signaling in ARF6-mediated metastatic progression of melanoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6078.

Mouse models of uveal melanoma: Strengths, weaknesses, and future directions

Uveal melanoma is the most common primary malignancy of the eye, and a number of discoveries in the last decade have led to a more thorough molecular characterization of this cancer. However, the prognosis remains dismal for patients with metastases, and there is an urgent need to identify treatments that are effective for this stage of disease. Animal models are important tools for preclinical studies of uveal melanoma. A variety of models exist, and they have specific advantages, disadvantages, and applications. In this review article, these differences are explored in detail, and ideas for new models that might overcome current challenges are proposed.

The Association of Gait Speed and Frontal Lobe among Various Cognitive Domains: The Korean Frailty and Aging Cohort Study (KFACS)

OBJECTIVE

The aim of this study was to determine how gait speed and frontal lobe functionsin community-dwelling older adults in Korea.

DESIGN

This was a cross-sectional study.

SETTING

The study used data from the Korean Frailty and Aging Cohort Survey (KFACS), a multi-center longitudinal study addressing 10 centers across urban, rural, and suburban communities in Korea, between 2016 and 2017.

PARTICIPANTS

A total of 1552 older adults who underwent both gait speed tests and cognitive functions tests during the investigation of the KFACS.

MEASUREMENTS

Gait speed was assessed by asking participants to walk from a starting point to a point 4 meters away at a normal gait. Cognitive functions were evaluated using various standardized cognitive functions tests.

RESULTS

Gait speed was slower when participants were older or less educated The percentage of women, higher BMI, people with lower incomes, singles, smokers, and drinkers was high in the slower gait group. Also, all cognitive function scores were low and depression score was high in the group with slower walking speed. The slower walking speed showed low physical activity score and high prevalence of hypertension, osteoarthritis and osteoporosis. Among the seven cognitive functions (MMSE, memory, TMT, Recall, Recognition, digit span, and Fab), only TMT showed no significant difference between different gait speed groups. The other six cognitive functions showed higher results in the fastest gait speed group (T3), Participants in middle gait speed group (T2) also showed higher results in five of the seven cognitive function scores as well (Memory, Recall, Recognition, digit span, and Fab).

CONCLUSION

In this study, we found correlation between the slower gait speeds and the decrease in cognitive function, and especially the frontal lobe dysfunction was most prominent of all cognitive dysfunctions.

Nuclear Dependence of the Transverse Single-Spin Asymmetry in the Production of Charged Hadrons at Forward Rapidity in Polarized p+p, p+Al, and p+Au Collisions at sqrt[s_{NN}]=200 GeV

We report on the nuclear dependence of transverse single-spin asymmetries (TSSAs) in the production of positively charged hadrons in polarized p^{↑}+p, p^{↑}+Al, and p^{↑}+Au collisions at sqrt[s_{NN}]=200  GeV. The measurements have been performed at forward rapidity (1.4<η<2.4) over the range of transverse momentum (1.8<p_{T}<7.0  GeV/c) and Feynman x (0.1<x_{F}<0.2). We observed positive asymmetries for positively charged hadrons in p^{↑}+p collisions, and significantly reduced asymmetries in p^{↑}+A collisions. These results reveal a nuclear dependence of TSSAs for charged-hadron production in a regime where perturbative techniques are applicable. These results provide new opportunities to use p^{↑}+A collisions as a tool to investigate the rich phenomena behind TSSAs in hadronic collisions and to use TSSAs as a new handle in studying small-system collisions.

Beam Energy and Centrality Dependence of Direct-Photon Emission from Ultrarelativistic Heavy-Ion Collisions

The PHENIX collaboration presents first measurements of low-momentum (0.4<p_{T}<3  GeV/c) direct-photon yields from Au+Au collisions at sqrt[s_{NN}]=39 and 62.4 GeV. For both beam energies the direct-photon yields are substantially enhanced with respect to expectations from prompt processes, similar to the yields observed in Au+Au collisions at sqrt[s_{NN}]=200. Analyzing the photon yield as a function of the experimental observable dN_{ch}/dη reveals that the low-momentum (>1  GeV/c) direct-photon yield dN_{γ}^{dir}/dη is a smooth function of dN_{ch}/dη and can be well described as proportional to (dN_{ch}/dη)^{α} with α≈1.25. This scaling behavior holds for a wide range of beam energies at the Relativistic Heavy Ion Collider and the Large Hadron Collider, for centrality selected samples, as well as for different A+A collision systems. At a given beam energy, the scaling also holds for high p_{T} (>5  GeV/c), but when results from different collision energies are compared, an additional sqrt[s_{NN}]-dependent multiplicative factor is needed to describe the integrated-direct-photon yield.

Tris DBA palladium is an orally available inhibitor of GNAQ mutant uveal melanoma in vivo

Uveal melanoma is a rare but often lethal malignancy and is the leading cause of death due to an ophthalmic condition. Uveal melanoma is often diagnosed at a late stage and has a strong propensity to hepatic metastasis. Recently, the most common driver mutations in uveal melanoma have been identified, predominantly in the G-proteins GNAQ. This pattern differs from that of cutaneous melanoma in which Braf and Nras predominate. There are no current clinically used agents that target GNAQ mutations, unlike the use of Braf inhibitors in cutaneous melanoma. We tested the novel agent Tris DBA palladium and found that it was markedly more effective against GNAQ mutant melanomas than wild type uveal melanomas. Given that ARF6 has recently been discovered as a node in GNAQ mutations, we evaluated the efficacy of Tris DBA palladium on ARF6 signaling and found that it was effective in inhibiting ARF6 activation. Finally, Tris DBA palladium was orally effective against GNAQ mutant melanoma in vivo. Tris DBA Palladium deserves further evaluation as a systemic agent for uveal melanoma.

The Small GTPase ARF6 Activates PI3K in Melanoma to Induce a Prometastatic State

Melanoma has an unusual capacity to spread in early-stage disease, prompting aggressive clinical intervention in very thin primary tumors. Despite these proactive efforts, patients with low-risk, low-stage disease can still develop metastasis, indicating the presence of permissive cues for distant spread. Here, we show that constitutive activation of the small GTPase ARF6 (ARF6^Q67L) is sufficient to accelerate metastasis in mice with BRAF^V600E/Cdkn2a^NULL melanoma at a similar incidence and severity to Pten loss, a major driver of PI3K activation and melanoma metastasis. ARF6^Q67L promoted spontaneous metastasis from significantly smaller primary tumors than PTEN^NULL, implying an enhanced ability of ARF6-GTP to drive distant spread. ARF6 activation increased lung colonization from circulating melanoma cells, suggesting that the prometastatic function of ARF6 extends to late steps in metastasis. Unexpectedly, ARF6^Q67L tumors showed upregulation of Pik3r1 expression, which encodes the p85 regulatory subunit of PI3K. Tumor cells expressing ARF6^Q67L displayed increased PI3K protein levels and activity, enhanced PI3K distribution to cellular protrusions, and increased AKT activation in invadopodia. ARF6 is necessary and sufficient for activation of both PI3K and AKT, and PI3K and AKT are necessary for ARF6-mediated invasion. We provide evidence for aberrant ARF6 activation in human melanoma samples, which is associated with reduced survival. Our work reveals a previously unknown ARF6-PI3K-AKT proinvasive pathway, it demonstrates a critical role for ARF6 in multiple steps of the metastatic cascade, and it illuminates how melanoma cells can acquire an early metastatic phenotype in patients. SIGNIFICANCE: These findings reveal a prometastatic role for ARF6 independent of tumor growth, which may help explain how melanoma spreads distantly from thin, early-stage primary tumors.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/79/11/2892/F1.large.jpg.

Cooper Pair Density of Bi2Sr2CaCu2O8+ x in Atomic scale at 4.2 K

In pursuit of the elusive mechanism of high- T _C superconductors (HTSC), spectroscopic imaging scanning tunneling microscopy (SI-STM) is an indispensable tool for surveying local properties of HTSC. Since a conventional STM utilizes metal tips, which allow the examination of only quasiparticles and not superconducting (SC) pairs, Josephson tunneling using STM has been demonstrated by many authors in the past. An atomically resolved scanning Josephson tunneling microscopy (SJTM), however, was realized only recently on Bi₂Sr₂CaCu₂O_{8+ x} (Bi-2212) below 50 mK and on the Pb(110) surface at 20 mK. Here we report the atomically resolved SJTM on Bi₂Sr₂CaCu₂O_{8+ x} at 4.2 K using Bi-2212 tips created in situ. The I- V characteristics show clear zero bias conductance peaks following Ambegaokar-Baratoff (AB) theory. A gap map was produced for the first time using an atomically resolved Josephson critical current map I _C( r) and AB theory. Surprisingly, we found that this new gap map is anticorrelated to the gap map produced by a conventional method relying on the coherence peaks. Quasiparticle resonance due to a single isolated zinc atom impurity was also observed by SJTM, indicating that atomically resolved SJTM was achieved at 4.2 K. Our result provides a starting point for realizing SJTM at even higher temperatures, rendering possible investigation of the existence of SC pairs in HTSC above the T _C.

Sulfuretin Prevents Obesity and Metabolic Diseases in Diet Induced Obese Mice

The global obesity epidemic and associated metabolic diseases require alternative biological targets for new therapeutic strategies. In this study, we show that a phytochemical sulfuretin suppressed adipocyte differentiation of preadipocytes and administration of sulfuretin to high fat diet-fed obese mice prevented obesity and increased insulin sensitivity. These effects were associated with a suppressed expression of inflammatory markers, induced expression of adiponectin, and increased levels of phosphorylated ERK and AKT. To elucidate the molecular mechanism of sulfuretin in adipocytes, we performed microarray analysis and identified activating transcription factor 3 (Atf3) as a sulfuretin-responsive gene. Sulfuretin elevated Atf3 mRNA and protein levels in white adipose tissue and adipocytes. Consistently, deficiency of Atf3 promoted lipid accumulation and the expression of adipocyte markers. Sulfuretin’s but not resveratrol’s anti-adipogenic effects were diminished in Atf3 deficient cells, indicating that Atf3 is an essential factor in the effects of sulfuretin. These results highlight the usefulness of sulfuretin as a new anti-obesity intervention for the prevention of obesity and its associated metabolic diseases.

Pseudorapidity Dependence of Particle Production and Elliptic Flow in Asymmetric Nuclear Collisions of p+Al, p+Au, d+Au, and ^{3}He+Au at sqrt[s_{NN}]=200 GeV

Asymmetric nuclear collisions of p+Al, p+Au, d+Au, and ^{3}He+Au at sqrt[s_{NN}]=200  GeV provide an excellent laboratory for understanding particle production, as well as exploring interactions among these particles after their initial creation in the collision. We present measurements of charged hadron production dN_{ch}/dη in all such collision systems over a broad pseudorapidity range and as a function of collision multiplicity. A simple wounded quark model is remarkably successful at describing the full data set. We also measure the elliptic flow v_{2} over a similarly broad pseudorapidity range. These measurements provide key constraints on models of particle emission and their translation into flow.

Measurements of Multiparticle Correlations in d+Au Collisions at 200, 62.4, 39, and 19.6 GeV and p+Au Collisions at 200 GeV and Implications for Collective Behavior

Recently, multiparticle-correlation measurements of relativistic p/d/^{3}He+Au, p+Pb, and even p+p collisions show surprising collective signatures. Here, we present beam-energy-scan measurements of two-, four-, and six-particle angular correlations in d+Au collisions at sqrt[s_{NN}]=200, 62.4, 39, and 19.6 GeV. We also present measurements of two- and four-particle angular correlations in p+Au collisions at sqrt[s_{NN}]=200  GeV. We find the four-particle cumulant to be real valued for d+Au collisions at all four energies. We also find that the four-particle cumulant in p+Au has the opposite sign as that in d+Au. Further, we find that the six-particle cumulant agrees with the four-particle cumulant in d+Au collisions at 200 GeV, indicating that nonflow effects are subdominant. These observations provide strong evidence that the correlations originate from the initial geometric configuration, which is then translated into the momentum distribution for all particles, commonly referred to as collectivity.

Nuclear Dependence of the Transverse-Single-Spin Asymmetry for Forward Neutron Production in Polarized p+A Collisions at sqrt[s_{NN}]=200 GeV

During 2015, the Relativistic Heavy Ion Collider (RHIC) provided collisions of transversely polarized protons with Au and Al nuclei for the first time, enabling the exploration of transverse-single-spin asymmetries with heavy nuclei. Large single-spin asymmetries in very forward neutron production have been previously observed in transversely polarized p+p collisions at RHIC, and the existing theoretical framework that was successful in describing the single-spin asymmetry in p+p collisions predicts only a moderate atomic-mass-number (A) dependence. In contrast, the asymmetries observed at RHIC in p+A collisions showed a surprisingly strong A dependence in inclusive forward neutron production. The observed asymmetry in p+Al collisions is much smaller, while the asymmetry in p+Au collisions is a factor of 3 larger in absolute value and of opposite sign. The interplay of different neutron production mechanisms is discussed as a possible explanation of the observed A dependence.

Small GTPase ARF6 controls VEGFR2 trafficking and signaling in diabetic retinopathy

The devastating sequelae of diabetes mellitus include microvascular permeability, which results in retinopathy. Despite clinical and scientific advances, there remains a need for new approaches to treat retinopathy. Here, we have presented a possible treatment strategy, whereby targeting the small GTPase ARF6 alters VEGFR2 trafficking and reverses signs of pathology in 4 animal models that represent features of diabetic retinopathy and in a fifth model of ocular pathological angiogenesis. Specifically, we determined that the same signaling pathway utilizes distinct GEFs to sequentially activate ARF6, and these GEFs exert distinct but complementary effects on VEGFR2 trafficking and signal transduction. ARF6 activation was independently regulated by 2 different ARF GEFs - ARNO and GEP100. Interaction between VEGFR2 and ARNO activated ARF6 and stimulated VEGFR2 internalization, whereas a VEGFR2 interaction with GEP100 activated ARF6 to promote VEGFR2 recycling via coreceptor binding. Intervening in either pathway inhibited VEGFR2 signal output. Finally, using a combination of in vitro, cellular, genetic, and pharmacologic techniques, we demonstrated that ARF6 is pivotal in VEGFR2 trafficking and that targeting ARF6-mediated VEGFR2 trafficking has potential as a therapeutic approach for retinal vascular diseases such as diabetic retinopathy.

Trends in device utilization ratios in intensive care units over 10-year period in South Korea: device utilization ratio as a new aspect of surveillance

BACKGROUND

Device-associated infection (DAI) is an important issue related to patient safety. It is important to reduce unnecessary device utilization in order to decrease DAI rates.

AIM

To investigate the time trend of device utilization ratios (DURs) of voluntarily participating hospitals, collected over a 10-year period through the Korean National Healthcare-associated Infections Surveillance System (KONIS).

METHODS

DURs from 2006 to 2015 in 190 intensive care units (ICUs) participating in KONIS were included in this study. DURs were calculated as the ratio of device-days to patient-days. The pooled incidences of DAIs and DURs were calculated for each year of participation, and the year-wise trends were analysed.

FINDINGS

Year-wise ventilator utilization ratio (V-DUR) increased significantly from 0.40 to 0.41 (F = 6.27, P < 0.01), urinary catheter utilization ratio (U-DUR) increased non-significantly from 0.83 to 0.84 (F = 1.66, P = 0.10), and C-line utilization ratio (CL-DUR) decreased non-significantly from 0.55 to 0.51 (F = 1.62, P = 0.11). In the subgroup analysis, 'medical ICU' (F = 2.79, P < 0.01) and 'hospital with >900 beds' (F = 3.07, P < 0.01) were associated with the significant increase in V-DUR.

CONCLUSION

In Korea, V-DUR showed a significant, year-wise increasing trend. The trends for U-DUR and CL-DUR showed no significant decrease. Efforts are required to ensure the reduction of DURs.

Development of a finger-like mechanism of end-effector for micro surgery

Neurosurgery had been considered nearly impossible due to its technical difficulty and the danger to its special target organ, but with endoscopic methods, many such surgeries can be made safely through the nose. Endoscopic neurosurgery is limited by available instruments, however, and there remain some areas of the human body inaccessible to standard surgical tools. To overcome some of these limitations, in this study we developed a simple mechanism that could form a high curvature in a narrow space. The end product is a finger-like mechanism consisting of five body parts and four joints. All body parts are connected in series, having a total length of 20mm and a diameter of φ4mm. A four-bar linkage internally connects the body parts and joints, and a nitinol backbone was used to improve repeatability. The first joint is driven by a rod or wire, and the shape of the mechanism is determined by rotating the first joint, because the position of each joint depends on the position of the joint before it. The study verified that an image sensor in the end of the finger-like mechanism has a wider range of view, 210 degrees than a conventional endoscope of 100 degrees. Finally, skull model simulation suggests that this device could be used in real neurosurgical applications.

Improved design for a low temperature scanning tunneling microscope with an in situ tip treatment stage

The Low Temperature Scanning Tunneling Microscope (LT-STM) is an extremely valuable tool not only in surface science but also in condensed matter physics. For years, numerous new ideas have been adopted to perfect LT-STM performances-Ultra-Low Vibration (ULV) laboratory and the rigid STM head design are among them. Here, we present three improvements for the design of the ULV laboratory and the LT-STM: tip treatment stage, sample cleaving stage, and vibration isolation system. The improved tip treatment stage enables us to perform field emission for the purpose of tip treatment in situ without exchanging samples, while our enhanced sample cleaving stage allows us to cleave samples at low temperature in a vacuum without optical access by a simple pressing motion. Our newly designed vibration isolation system provides efficient space usage while maintaining vibration isolation capability. These improvements enhance the quality of spectroscopic imaging experiments that can last for many days and provide increased data yield, which we expect can be indispensable elements in future LT-STM designs.

The small GTPase ARF6 regulates protein trafficking to control cellular function during development and in disease

The activation of the small GTPase ARF6 has been implicated in promoting several pathological processes related to vascular instability and tumor formation, growth, and metastasis. ARF6 also plays a vital role during embryonic development. Recent studies have suggested that ARF6 carries out these disparate functions primarily by controlling protein trafficking within the cell. ARF6 helps direct proteins to intracellular or extracellular locations where they function in normal cellular responses during development and in pathological processes later in life. This transport of proteins is accomplished through a variety of mechanisms, including endocytosis and recycling, microvesicle release, and as yet uncharacterized processes. This Commentary will explore the functions of ARF6, while focusing on the role of this small GTPase in development and postnatal physiology, regulating barrier function and diseases associated with its loss, and tumor formation, growth, and metastasis.

ARF6 Is an Actionable Node that Orchestrates Oncogenic GNAQ Signaling in Uveal Melanoma

Activating mutations in Gαq proteins, which form the α subunit of certain heterotrimeric G proteins, drive uveal melanoma oncogenesis by triggering multiple downstream signaling pathways, including PLC/PKC, Rho/Rac, and YAP. Here we show that the small GTPase ARF6 acts as a proximal node of oncogenic Gαq signaling to induce all of these downstream pathways as well as β-catenin signaling. ARF6 activates these diverse pathways through a common mechanism: the trafficking of GNAQ and β-catenin from the plasma membrane to cytoplasmic vesicles and the nucleus, respectively. Blocking ARF6 with a small-molecule inhibitor reduces uveal melanoma cell proliferation and tumorigenesis in a mouse model, confirming the functional relevance of this pathway and suggesting a therapeutic strategy for Gα-mediated diseases.

Centrality-Dependent Modification of Jet-Production Rates in Deuteron-Gold Collisions at √[s(NN)]=200 GeV

Jet production rates are measured in p+p and d+Au collisions at sqrt[s_{NN}]=200  GeV recorded in 2008 with the PHENIX detector at the Relativistic Heavy Ion Collider. Jets are reconstructed using the R=0.3 anti-k_{t} algorithm from energy deposits in the electromagnetic calorimeter and charged tracks in multiwire proportional chambers, and the jet transverse momentum (p_{T}) spectra are corrected for the detector response. Spectra are reported for jets with 12<p_{T}<50  GeV/c, within a pseudorapidity acceptance of |η|<0.3. The nuclear-modification factor (R_{dAu}) values for 0%-100% d+Au events are found to be consistent with unity, constraining the role of initial state effects on jet production. However, the centrality-selected R_{dAu} values and central-to-peripheral ratios (R_{CP}) show large, p_{T}-dependent deviations from unity, challenging the conventional models that relate hard-process rates and soft-particle production in collisions involving nuclei.

Effect of the Film-Growth Defects on the Magnetic Microstructure of Epitaxial FePt Thin Film

Effect of the columnar grain boundaries on the perpendicular magnetic domain structure of epitaxial L10 FePt (001) thin film has been studied using electron holography. The analysis of stray fields shows that both the continuous and columnar epitaxial films of L10 FePt (001) consist of perpendicular magnetic domain walls. In the columnar epitaxial film, however, the perpendicular domain walls tend to be confined to columnar grain boundaries, because columnar boundaries act as pinning sites for the domain walls. The domain wall pinning by columnar grain boundaries leads to a significant hysteresis effect in the perpendicular magnetization of L10 FePt epitaxial films.

Measurements of Elliptic and Triangular Flow in High-Multiplicity 3He+Au Collisions at √(s(NN))=200 GeV

We present the first measurement of elliptic (v(2)) and triangular (v(3)) flow in high-multiplicity (3)He+Au collisions at √(s(NN))=200  GeV. Two-particle correlations, where the particles have a large separation in pseudorapidity, are compared in (3)He+Au and in p+p collisions and indicate that collective effects dominate the second and third Fourier components for the correlations observed in the (3)He+Au system. The collective behavior is quantified in terms of elliptic v(2) and triangular v(3) anisotropy coefficients measured with respect to their corresponding event planes. The v(2) values are comparable to those previously measured in d+Au collisions at the same nucleon-nucleon center-of-mass energy. Comparisons with various theoretical predictions are made, including to models where the hot spots created by the impact of the three (3)He nucleons on the Au nucleus expand hydrodynamically to generate the triangular flow. The agreement of these models with data may indicate the formation of low-viscosity quark-gluon plasma even in these small collision systems.

Reliability and validity of lower extremity computed tomography as a screening tool for osteoporosis

We evaluated the correlation between central bone mineral density (BMD) and peripheral bone attenuation using lower extremity computed tomography (CT). A good correlation was found between lower extremity CT and central BMD suggesting that CT is useful for screening osteoporosis, and that peripheral bone attenuation adequately reflects central BMD.

INTRODUCTION

This study aimed to evaluate the reliability and validity of CT as a screening tool for osteoporosis and to estimate the correlation between central BMD and peripheral bone attenuation using lower extremity CT.

METHODS

In total, 292 patients who underwent a lower extremity, lumbar spine, or abdomen and pelvic CT scan within a 3-month interval of a dual-energy X-ray absorptiometry (DEXA) examination were included. Following reliability testing, bone attenuation of the L1, L2, L3, L4, femoral head, femoral neck, greater trochanter, distal femur, proximal tibia, distal tibia, and talus was measured by placing a circular region of interest on the central part of each bony region on a coronal CT image. Partial correlation was used to assess the correlation between CT and DEXA after adjusting for age and body mass index.

RESULTS

In terms of reliability, all bone attenuation measurements, except the femoral neck, showed good to excellent interobserver reliability (intraclass correlation coefficients, 0.691-0.941). In terms of validity, bone attenuation of the L1 to L4, femoral neck, and greater trochanter on CT showed significant correlations with BMD of each area on DEXA (correlation coefficients, 0.399-0.613). Bone attenuation of the distal tibia and talus on CT showed significant correlations with BMD of all parts on DEXA (correlation coefficients, 0.493-0.581 for distal tibia, 0.396-0.579 for talus).

CONCLUSION

Lower extremity CT is a useful screening tool for osteoporosis, and peripheral bone attenuation on lower extremity CT adequately reflects central BMD on DEXA.

Use of permanent marker to deposit a protection layer against FIB damage in TEM specimen preparation

Permanent marker deposition (PMD), which creates permanent writing on an object with a permanent marker, was investigated as a method to deposit a protection layer against focused ion beam damage. PMD is a simple, fast and cheap process. Further, PMD is excellent in filling in narrow and deep trenches, enabling damage-free observation of high aspect ratio structures with atomic resolution in transmission electron microscopy (TEM). The microstructure, composition, gap filling ability and planarization of the PMD layer were studied using dual beam focused ion beam, transmission electron microscopy, energy dispersive X-ray spectroscopy and electron energy loss spectroscopy. It was found that a PMD layer is basically an amorphous carbon structure, and that such a layer should be at least 65 nm thick to protect a surface against 30 keV focused ion beam damage. We suggest that such a PMD layer can be an excellent protection layer to maintain a pristine sample structure against focused ion beam damage during transmission electron microscopy specimen preparation.

Management of traumatic labral tear in acetabular fractures with posterior wall component

BACKGROUND

Posterior labral tear is frequently encountered in acetabular fractures with posterior wall component (AFPWC). However, there has been very little information in the literature on the type and management of traumatic labral tears in AFPWC.

HYPOTHESIS

Traumatic labral tear is a constant intracapsular injury in AFPWC and can be repaired using adequate methods according to its type and size.

MATERIALS AND METHODS

A retrospective study of 14 patients (mean age 38 years [16-58]) who underwent open surgery for AFPWC was conducted using prospectively collected data. The types of posterior labral tear were investigated at intraoperative examination through the ruptured joint capsule or its extension, and were concomitantly managed. Surgical outcomes were clinically assessed using Merle d'Aubigné (PMA) score and Visual Analog Scale (VAS), and radiologically evaluated at final follow-up.

RESULTS

Posterior labral tears were present in all 14 patients. The types of labral tear were osseous avulsion and posterior root avulsion tear (n=9), longitudinal peripheral tear and posterior root avulsion tear (n=2), longitudinal peripheral tear (n=2), and osseous avulsion tear (n=1). All unstable labra in 12 patients (86%) were repaired. All avulsion tears of the posterior root were repaired using a suture anchor, longitudinal peripheral tears using suture fixation or/and suture anchors, and osseous avulsion tears using a spring plate. The mean PMA score and VAS were 16.4 (14-18) and 1.7 (0-3) at final follow-up, respectively. The radiologic grades at last follow-up were good or excellent in all patients.

DISCUSSION

All AFPWC in this study consistently revealed posterior labral tear. Posterior root avulsion tears accompanied with osseous avulsion was the most common type. Torn labra should be repaired as much as possible if unstable, considering the important functions of a normal labrum; fixation using a suture anchor may be useful for an avulsion tear of the posterior root.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

The small GTPase ARF6 stimulates β-catenin transcriptional activity during WNT5A-mediated melanoma invasion and metastasis

β-Catenin has a dual function in cells: fortifying cadherin-based adhesion at the plasma membrane and activating transcription in the nucleus. We found that in melanoma cells, WNT5A stimulated the disruption of N-cadherin and β-catenin complexes by activating the guanosine triphosphatase adenosine diphosphate ribosylation factor 6 (ARF6). Binding of WNT5A to the Frizzled 4-LRP6 (low-density lipoprotein receptor-related protein 6) receptor complex activated ARF6, which liberated β-catenin from N-cadherin, thus increasing the pool of free β-catenin, enhancing β-catenin-mediated transcription, and stimulating invasion. In contrast to WNT5A, the guidance cue SLIT2 and its receptor ROBO1 inhibited ARF6 activation and, accordingly, stabilized the interaction of N-cadherin with β-catenin and reduced transcription and invasion. Thus, ARF6 integrated competing signals in melanoma cells, thereby enabling plasticity in the response to external cues. Moreover, small-molecule inhibition of ARF6 stabilized adherens junctions, blocked β-catenin signaling and invasiveness of melanoma cells in culture, and reduced spontaneous pulmonary metastasis in mice, suggesting that targeting ARF6 may provide a means of inhibiting WNT/β-catenin signaling in cancer.

Comparison between the LMA Classic™ and New I-gel™ Supraglottic Airway Device: A Manikin Study

Objective

It is nowadays well established that the laryngeal mask airway (LMA) is an alternative airway to endotracheal intubation for prehospital environment. However, problems have been reported and many other kinds of supraglottic airway devices (SGDs) were introduced. The I-gel™ is one of the latest SGD, and it has been designed for easy and fast insertion with non-inflatable cuff. We compared the efficacy between LMA Classic™ and I-gel™ by using both normal and difficult airway conditioned manikin.

Methods

One hundred and two non-experienced volunteers made out of students and nurses participated in the airway management educational program that was held in the emergency medical center of Gwangmyeong Sungae Hospital. After finishing the program, the participants were tested on their performance skills (insertion time) on using the two devices in both normal and difficult airway conditioned manikin. A structured questionnaire was used to measure the knowledge, attitude and preference about each device on a 5-point scale.

Results

In the LMA Classic™ and I-gel™ groups, it took 28.3±8.3 and 10.0±3.7 seconds with normal airway conditioned manikin (p<0.001), and 29.1±8.2 and 10.3±3.0 seconds elapsed with difficult airway conditioned manikin to achieve adequate airway management (p<0.001) in the corresponding order. The attitude and preference scale of the I-gel™ was higher than those of the LMA Classic™ (p<0.001).

Conclusions

The insertion time of the I-gel™ was shorter than that of the LMA Classic™ in both normal and difficult airway conditioned manikin, and I-gel™ had a higher positive response for attitude and preference.

PET/CT and MRI of intra-osseous haemangioma of the tibia

Intra-osseous haemangioma is a rare, benign neoplasm that usually involves the vertebrae and craniofacial bones. Furthermore, its occurrence in the long bones is extremely rare. We report the findings of fluorine-18-fludeoxyglucose ((18)F-FDG) positron emission tomography (PET)/CT and MRI in a patient with intra-osseous haemangioma in the proximal tibia, who was initially misdiagnosed as having a malignancy based on (18)F-FDG PET/CT. (18)F-FDG PET/CT showed a well-marginated osteolytic lesion with abnormal FDG uptake. The mass demonstrated low signal intensity on T(1) weighted MRI. On T(2) weighted images, the lesion appeared as a cluster of high signal intensity lobules and showed strong enhancement on contrast-enhanced T(1) weighted images. Surgical curettage was performed and histopathological examination of the excised tissue confirmed a cavernous haemangioma.

Kikuchi disease: differentiation from tuberculous lymphadenitis based on patterns of nodal necrosis on CT

BACKGROUND AND PURPOSE

KD, also known as histiocytic necrotizing lymphadenitis, is often mimicked by TL, especially when KD is accompanied by gross necrosis on CT. We analyzed the nodal necrosis patterns on CT in patients with KD and TL to identify the predictive features that differentiate these 2 entities.

MATERIALS AND METHODS

We included 24 patients with KD (14 females, 10 males; mean age, 25.1 years) and 45 with TL (36 women, 9 men; mean age, 39.9 years) having nodal necrosis on CT. The extent, number, location, and margins of nodal necrosis; the presence of perinodal infiltration; and nodal calcification were analyzed. Two attenuation indices for nodal necrosis were derived: CTN and CTN/M. The CT features of the 2 diseases were compared, and multivariate logistic regression analysis was performed to identify predictive features that would aid in differentiating KD from TL.

RESULTS

Mild or moderate extent of nodal necrosis (P = .000), multiple necrotic foci (P = .002), indistinct margins of necrotic foci (P = .000), CTN of >44.5 (P = .000), CTN/M of >0.7 (P = .000), and absence of nodal calcification (P = .012) were associated with KD. Multivariate logistic regression analysis revealed that indistinct margins of necrotic foci were independent predictors, with 80% accuracy.

CONCLUSIONS

The presence of indistinct margins of necrotic foci was an independent predictor in differentiating KD from TL with high diagnostic accuracy.

Early-onset Charcot-Marie-Tooth patients with mitofusin 2 mutations and brain involvement

Mutations of the mitofusin 2 (MFN2) gene have been reported to be the most common cause of the axonal form of Charcot-Marie-Tooth disease (CMT). A prospective brain MRI study was performed on 18 early-onset CMT patients with MFN2 mutations, and a high frequency (39%) of brain abnormalities was found. Early-onset patients showed multiple scattered or confluent brain lesions that involved gray matter as well as white matter. Patterns of brain involvement in early-onset patients differed from those of late-onset patients and other hereditary peripheral neuropathies. In addition, one CMT patient demonstrated a brain lesion before the development of peripheral neuropathy.

A computerized tomography scan method for calculating the hernia sac and abdominal cavity volume in complex large incisional hernia with loss of domain

Preoperative progressive pneumoperitoneum (PPP) is a safe and effective procedure in the treatment of large incisional hernia (size > 10 cm in width or length) with loss of domain (LIHLD). There is no consensus in the literature on the amount of gas that must be insufflated in a PPP program or even how long it should be maintained. We describe a technique for calculating the hernia sac volume (HSV) and abdominal cavity volume (ACV) based on abdominal computerized tomography (ACT) scanning that eliminates the need for subjective criteria for inclusion in a PPP program and shows the amount of gas that must be insufflated into the abdominal cavity in the PPP program. Our technique is indicated for all patients with large or recurrent incisional hernias evaluated by a senior surgeon with suspected LIHLD. We reviewed our experience from 2001 to 2008 of 23 consecutive hernia surgical procedures of LIHLD undergoing preoperative evaluation with CT scanning and PPP. An ACT was required in all patients with suspected LIHLD in order to determine HSV and ACV. The PPP was performed only if the volume ratio HSV/ACV (VR = HSV/ACV) was >or=25% (VR >or= 25%). We have performed this procedure on 23 patients, with a mean age of 55.6 years (range 31-83). There were 16 women and 7 men with an average age of 55.6 years (range 31-83), and a mean BMI of 38.5 kg/m(2) (range 23-55.2). Almost all patients (21 of 23 patients-91.30%) were overweight; 43.5% (10 patients) were severely obese (obese class III). The mean calculated volumes for ACV and HSV were 9,410 ml (range 6,060-19,230 ml) and 4,500 ml (range 1,850-6,600 ml), respectively. The PPP is performed by permanent catheter placed in a minor surgical procedure. The total amount of CO(2) insufflated ranged from 2,000 to 7,000 ml (mean 4,000 ml). Patients required a mean of 10 PPP sessions (range 4-18) to achieve the desired volume of gas (that is the same volume that was calculated for the hernia sac). Since PPP sessions were performed once a day, 4-18 days were needed for preoperative preparation with PPP. The mean VR was 36% (ranged from 26 to 73%). We conclude that ACT provides objective data for volume calculation of both hernia sac and abdominal cavity and also for estimation of the volume of gas that should be insufflated into the abdominal cavity in PPP.

Regulation of MAPK phosphatase 1 (AtMKP1) by calmodulin in Arabidopsis

The mitogen-activated protein kinases (MAPKs) are key signal transduction molecules, which respond to various external stimuli. The MAPK phosphatases (MKPs) are known to be negative regulators of MAPKs in eukaryotes. We screened an Arabidopsis cDNA library using horseradish peroxidase-conjugated calmodulin (CaM), and isolated AtMKP1 as a CaM-binding protein. Recently, tobacco NtMKP1 and rice OsMKP1, two orthologs of Arabidopsis AtMKP1, were reported to bind CaM via a single putative CaM binding domain (CaMBD). However, little is known about the regulation of phosphatase activity of plant MKP1s by CaM binding. In this study, we identified two Ca(2+)-dependent CaMBDs within AtMKP1. Specific binding of CaM to two different CaMBDs was verified using a gel mobility shift assay, a competition assay with a Ca(2+)/CaM-dependent enzyme, and a split-ubiquitin assay. The peptides for two CaMBDs, CaMBDI and CaMBDII, bound CaM in a Ca(2+)-dependent manner, and the binding affinity of CaMBDII was found to be higher than that of CaMBDI. CaM overlay assays using mutated CaMBDs showed that four amino acids, Trp(453) and Leu(456) in CaMBDI and Trp(678) and Ile(684) in CaMBDII, play a pivotal role in CaM binding. Moreover, the phosphatase activity of AtMKP1 was increased by CaM in a Ca(2+)-dependent manner. Our results suggest that two important signaling pathways, Ca(2+) signaling and the MAPK signaling cascade, are connected in plants via the regulation of AtMKP1 activity. To our knowledge, this is the first report to show that the biochemical activity of MKP1 in plants is regulated by CaM.

Decrease of D2 receptor binding but increase in D2-stimulated G-protein activation, dopamine transporter binding and behavioural sensitization in brains of mice treated with a chronic escalating dose 'binge' cocaine administration paradigm

Understanding the neurobiology of the transition from initial drug use to excessive drug use has been a challenge in drug addiction. We examined the effect of chronic 'binge' escalating dose cocaine administration, which mimics human compulsive drug use, on behavioural responses and the dopaminergic system of mice and compared it with a chronic steady dose (3 x 15 mg/kg/day) 'binge' cocaine administration paradigm. Male C57BL/6J mice were injected with saline or cocaine in an escalating dose paradigm for 14 days. Locomotor and stereotypy activity were measured and quantitative autoradiographic mapping of D(1) and D(2) receptors, dopamine transporters and D(2)-stimulated [(35)S]GTPgammaS binding was performed in the brains of mice treated with this escalating and steady dose paradigm. An initial sensitization to the locomotor effects of cocaine followed by a dose-dependent increase in the duration of the locomotor effect of cocaine was observed in the escalating but not the steady dose paradigm. Sensitization to the stereotypy effect of cocaine and an increase in cocaine-induced stereotypy score was observed from 3 x 20 to 3 x 25 mg/kg/day cocaine. There was a significant decrease in D(2) receptor density, but an increase in D(2)-stimulated G-protein activity and dopamine transporter density in the striatum of cocaine-treated mice, which was not observed in our steady dose paradigm. Our results document that chronic 'binge' escalating dose cocaine treatment triggers profound behavioural and neurochemical changes in the dopaminergic system, which might underlie the transition from drug use to compulsive drug use associated with addiction, which is a process of escalation.

Different clinical and magnetic resonance imaging features between Charcot-Marie-Tooth disease type 1A and 2A

Charcot-Marie-Tooth disease type 1A (CMT1A) is the more frequent cause of demyelinating CMT, and CMT2A is the most common cause of axonal CMT. We conducted a magnetic resonance imaging (MRI) study on 39 CMT1A and 21 CMT2A patients to compare their neuroimaging patterns and correlate with clinical features. CMT1A patients showed selective fatty infiltration with a preference for anterior and lateral compartment muscles, whereas CMT2A patients showed a preference for superficial posterior compartment muscles. Early-onset CMT2A patients showed more severe leg fatty atrophy than late-onset CMT2A patients. In late-onset CMT2A, soleus muscle was the earliest, and most severely affected than the other leg muscles. Selective involvement of intrinsic foot muscles is a characteristic pattern of minimal CMT1A and CMT2A. Our MRI study demonstrates different patterns of fatty infiltration involving superficial posterior compartment muscles in CMT2A (partial T-type), and peroneal nerve innervated muscles in CMT1A (P-type).

The relationship of the medially-offset stem of the tibial component to the medial tibial cortex in total knee replacements in Korean patients

We examined the placement of the stem in relation to the medial tibial cortex when using total knee replacements (TKRs) with medially-offset tibial stems in Korean patients. Measurements were performed on the pre- and post-operative radiographs of 246 osteoarthritic knees replaced between January 2005 and May 2006 using the Genesis II or E-motion TKR with a medially-offset stem. Pre-operatively, we measured the distance between the mechanical axis and that of the tibial shaft and post-operatively, that between the midline of the tibial stem and the axis of the shaft. Knees were identified in which there was radiological contact between the tip of the stem and the medial tibial cortex. The mechanical axis was located medial to the axis of the shaft in 203 knees (82.5%). Post-operatively, the midline of the tibial stem was located medial to the tibial shaft axis in 196 knees (79.7%). In 16 knees (6.5%) there was radiological contact between the tibial stem or cement mantle and the medial tibial cortex. Our study has shown that the medially-offset stem in the tibial component may not be a good option for knees undergoing replacement for advanced osteoarthritis in some Korean patients.

Identification of a calmodulin-binding NAC protein as a transcriptional repressor in Arabidopsis

Calmodulin (CaM), a ubiquitous calcium-binding protein, regulates diverse cellular functions by modulating the activity of a variety of proteins. However, little is known about how CaM directly regulates transcription. Screening of an Arabidopsis cDNA expression library using horseradish peroxidase-conjugated calmodulin as a probe identified a calmodulin-binding NAC protein (CBNAC). Using gel overlay assays, a Ca2+-dependent CaM-binding domain was identified in the C terminus of this protein. Specific binding of CaM to CaM-binding domain was corroborated by site-directed mutagenesis and a split-ubiquitin assay. Using a PCR-mediated random binding site selection method, we identified a DNA-binding sequence (CBNACBS) for CBNAC, which consisted of a GCTT core sequence flanked on both sides by other frequently repeating sequences (TTGCTTANNNNNNAAG). CBNAC was able to bind to CBNACBS, which resulted in the repression of transcription in Arabidopsis protoplasts. Interestingly, the transcriptional repression mediated by CBNAC was enhanced by CaM. These results suggest that CBNAC may be a CaM-regulated transcriptional repressor in Arabidopsis.

The determination of sensation-dependent bladder emptying time in patients with complete spinal cord injury above T11

STUDY DESIGN

Retrospective investigation using urodynamic studies and medical records.

OBJECTIVE

To evaluate the safety of sensation-dependent bladder emptying in complete spinal cord injury (SCI) patients, based on the preservation of the desire to void.

SETTING

Spinal Cord Injury Unit, Yonsei Rehabilitation Hospital, Seoul, Korea.

METHODS

This study was performed retrospectively on 79 complete SCI patients with lesions above T11, who had preserved the desire to void during conventional urodynamic studies. Patients were classified according to detrusor compliance and maximal bladder capacity. The clinical and urodynamic characteristics of each group were analyzed.

RESULTS

Forty-five (57.0%) patients were classified as group A and 34 (43.0%) patients were classified as group B. There were no significant differences in clinical features, such as voiding methods and the presence of autonomic dysreflexia between the two groups. Compared with group B, there were significantly more areflexic neurogenic bladder cases in group A (P<0.05). There were significantly higher maximal detrusor pressures in group B (P<0.05). There were significantly more cases with the preservation of the strong desire to void in group B (P<0.05).

CONCLUSION

Not all patients with discomplete SCIs accepted the use of sensation-dependent bladder emptying. The safe use of sensation-dependent bladder emptying will be determined based on the results of urodynamic studies.

Preprodynorphin mediates locomotion and D2 dopamine and mu-opioid receptor changes induced by chronic 'binge' cocaine administration

Evidence suggests that the kappa-opioid receptor (KOP-r) system plays an important role in cocaine addiction. Indeed, cocaine induces endogenous KOP activity, which is a mechanism that opposes alterations in behaviour and brain function resulting from repeated cocaine use. In this study, we have examined the influence of deletion of preprodynorphin (ppDYN) on cocaine-induced behavioural effects and on hypothalamic-pituitary-adrenal axis activity. Furthermore, we have measured mu-opioid receptor (MOP-r) agonist-stimulated [(35)S]GTPgammaS, dopamine D(1), D(2) receptor and dopamine transporter (DAT) binding. Male wild-type (WT) and ppDYN knockout (KO) mice were injected with saline or cocaine (45 mg/kg/day) in a 'binge' administration paradigm for 14 days. Chronic cocaine produced an enhancement of locomotor sensitisation in KO. No genotype effect was found on stereotypy behaviour. Cocaine-enhanced MOP-r activation in WT but not in KO. There was an overall decrease in D(2) receptor binding in cocaine-treated KO but not in WT mice. No changes were observed in D(1) and DAT binding. Cocaine increased plasma corticosterone levels in WT but not in KO. The data confirms that the endogenous KOP system inhibits dopamine neurotransmission and that ppDYN may mediate the enhancement of MOP-r activity and the activation of the hypothalamic-pituitary-adrenal axis after chronic cocaine treatment.

Isolation of a calmodulin-binding transcription factor from rice (Oryza sativa L.)

Calmodulin (CaM) regulates diverse cellular functions by modulating the activities of a variety of enzymes and proteins. However, direct modulation of transcription factors by CaM has been poorly understood. In this study, we isolated a putative transcription factor by screening a rice cDNA expression library by using CaM:horse-radish peroxidase as a probe. This factor, which we have designated OsCBT (Oryza sativa CaM-binding transcription factor), has structural features similar to Arabidopsis AtSRs/AtCAMTAs and encodes a 103-kDa protein because it contains a CG-1 homology DNA-binding domain, three ankyrin repeats, a putative transcriptional activation domain, and five putative CaM-binding motifs. By using a gel overlay assay, gel mobility shift assays, and site-directed mutagenesis, we showed that OsCBT has two different types of functional CaM-binding domains, an IQ motif, and a Ca(2+)-dependent motif. To determine the DNA binding specificity of OsCBT, we employed a random binding site selection method. This analysis showed that OsCBT preferentially binds to the sequence 5'-TWCG(C/T)GTKKKKTKCG-3' (W and K represent A or C and T or G, respectively). OsCBT was able to bind this sequence and activate beta-glucuronidase reporter gene expression driven by a minimal promoter containing tandem repeats of these sequences in Arabidopsis leaf protoplasts. Green fluorescent protein fusions of two putative nuclear localization signals of OsCBT, a bipartite and a SV40 type, were predominantly localized in the nucleus. Most interestingly, the transcriptional activation mediated by OsCBT was inhibited by co-transfection with a CaM gene. Taken together, our results suggest that OsCBT is a transcription activator modulated by CaM.