Search for a τ^{+}τ^{-} Resonance in e^{+}e^{-}→μ^{+}μ^{-}τ^{+}τ^{-} Events with the Belle II Experiment

We report the first search for a nonstandard-model resonance decaying into τ pairs in e^{+}e^{-}→μ^{+}μ^{-}τ^{+}τ^{-} events in the 3.6-10  GeV/c^{2} mass range. We use a 62.8  fb^{-1} sample of e^{+}e^{-} collisions collected at a center-of-mass energy of 10.58 GeV by the Belle II experiment at the SuperKEKB collider. The analysis probes three different models predicting a spin-1 particle coupling only to the heavier lepton families, a Higgs-like spin-0 particle that couples preferentially to charged leptons (leptophilic scalar), and an axionlike particle, respectively. We observe no evidence for a signal and set exclusion limits at 90% confidence level on the product of cross section and branching fraction into τ pairs, ranging from 0.7 to 24 fb, and on the couplings of these processes. We obtain world-leading constraints on the couplings for the leptophilic scalar model for masses above 6.5  GeV/c^{2} and for the axionlike particle model over the entire mass range.

Measurement of CP Violation in B^{0}→K_{S}^{0}π^{0} Decays at Belle II

We report a measurement of the CP-violating parameters C and S in B^{0}→K_{S}^{0}π^{0} decays at Belle II using a sample of 387×10^{6}  BB[over ¯] events recorded in e^{+}e^{-} collisions at a center-of-mass energy corresponding to the ϒ(4S) resonance. These parameters are determined by fitting the proper decay-time distribution of a sample of 415 signal events. We obtain C=-0.04_{-0.15}^{+0.14}±0.05 and S=0.75_{-0.23}^{+0.20}±0.04, where the first uncertainties are statistical and the second are systematic.

Test of Light-Lepton Universality in the Rates of Inclusive Semileptonic B-Meson Decays at Belle II

We present the first measurement of the ratio of branching fractions of inclusive semileptonic B-meson decays, R(X_{e/μ})=B(B→Xeν)/B(B→Xμν), a precision test of electron-muon universality, using data corresponding to 189  fb^{-1} from electron-positron collisions collected with the Belle II detector. In events where the partner B meson is fully reconstructed, we use fits to the lepton momentum spectra above 1.3  GeV/c to obtain R(X_{e/μ})=1.007±0.009(stat)±0.019(syst), which is the most precise lepton-universality test of its kind and agrees with the standard-model expectation.

First Measurement of the Michel Parameter ξ^{'} in the τ^{-}→μ^{-}ν[over ¯]_{μ}ν_{τ} Decay at Belle

We report the first measurement of the Michel parameter ξ^{'} in the τ^{-}→μ^{-}ν[over ¯]_{μ}ν_{τ} decay with a new method proposed just recently. The measurement is based on the reconstruction of the τ^{-}→μ^{-}ν[over ¯]_{μ}ν_{τ} events with subsequent muon decay in flight in the Belle central drift chamber. The analyzed data sample of 988  fb^{-1} collected by the Belle detector corresponds to approximately 912×10^{6} τ^{+}τ^{-} pairs. We measure ξ^{'}=0.22±0.94(stat)±0.42(syst), which is in agreement with the standard model prediction of ξ^{'}=1. Statistical uncertainty dominates in this study, being a limiting factor, while systematic uncertainty is well under control. Our analysis proved the practicability of this promising method and its prospects for further precise measurement in future experiments.

Search for the Lepton Flavor Violating Decays B^{+}→K^{+}τ^{±}ℓ^{∓} (ℓ=e, μ) at Belle

We present a search for the lepton flavor violating decays B^{+}→K^{+}τ^{±}ℓ^{∓}, with ℓ=(e,μ), using the full data sample of 772×10^{6}  BB[over ¯] pairs recorded by the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. We use events in which one B meson is fully reconstructed in a hadronic decay mode. We find no evidence for B^{±}→K^{±}τℓ decays and set upper limits on their branching fractions at the 90% confidence level in the (1-3)×10^{-5} range. The obtained limits are the world's best results.

Search for an Invisible Z^{'} in a Final State with Two Muons and Missing Energy at Belle II

The L_{μ}-L_{τ} extension of the standard model predicts the existence of a lepton-flavor-universality-violating Z^{'} boson that couples only to the heavier lepton families. We search for such a Z^{'} through its invisible decay in the process e^{+}e^{-}→μ^{+}μ^{-}Z^{'}. We use a sample of electron-positron collisions at a center-of-mass energy of 10.58 GeV collected by the Belle II experiment in 2019-2020, corresponding to an integrated luminosity of 79.7  fb^{-1}. We find no excess over the expected standard-model background. We set 90%-confidence-level upper limits on the cross section for this process as well as on the coupling of the model, which ranges from 3×10^{-3} at low Z^{'} masses to 1 at Z^{'} masses of 8  GeV/c^{2}.

First Measurement of the B^{+}→π^{+}π^{0}π^{0} Branching Fraction and CP Asymmetry

We study B^{+}→π^{+}π^{0}π^{0} using 711  fb^{-1} of data collected at the ϒ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. We measure an inclusive branching fraction of (19.0±1.5±1.4)×10^{-6} and an inclusive CP asymmetry of (9.2±6.8±0.7)%, where the first uncertainties are statistical and the second are systematic, and a B^{+}→ρ(770)^{+}π^{0} branching fraction of (11.2±1.1±0.9_{-1.6}^{+0.8})×10^{-6}, where the third uncertainty is due to possible interference with B^{+}→ρ(1450)^{+}π^{0}. We present the first observation of a structure around 1  GeV/c^{2} in the π^{0}π^{0} mass spectrum, with a significance of 6.4σ, and measure a branching fraction to be (6.9±0.9±0.6)×10^{-6}. We also report a measurement of local CP asymmetry in this structure.

Search for Lepton-Flavor-Violating τ Decays to a Lepton and an Invisible Boson at Belle II

We search for lepton-flavor-violating τ^{-}→e^{-}α and τ^{-}→μ^{-}α decays, where α is an invisible spin-0 boson. The search uses electron-positron collisions at 10.58 GeV center-of-mass energy with an integrated luminosity of 62.8  fb^{-1}, produced by the SuperKEKB collider and collected with the Belle II detector. We search for an excess in the lepton-energy spectrum of the known τ^{-}→e^{-}ν[over ¯]_{e}ν_{τ} and τ^{-}→μ^{-}ν[over ¯]_{μ}ν_{τ} decays. We report 95% confidence-level upper limits on the branching-fraction ratio B(τ^{-}→e^{-}α)/B(τ^{-}→e^{-}ν[over ¯]_{e}ν_{τ}) in the range (1.1-9.7)×10^{-3} and on B(τ^{-}→μ^{-}α)/B(τ^{-}→μ^{-}ν[over ¯]_{μ}ν_{τ}) in the range (0.7-12.2)×10^{-3} for α masses between 0 and 1.6  GeV/c^{2}. These results provide the most stringent bounds on invisible boson production from τ decays.

First Observation of Λπ^{+} and Λπ^{-} Signals near the K[over ¯]N(I=1) Mass Threshold in Λ_{c}^{+}→Λπ^{+}π^{+}π^{-} Decay

Using the data sample of 980  fb^{-1} collected with the Belle detector operating at the KEKB asymmetric-energy e^{+}e^{-} collider, we present the results of an investigation of the Λπ^{+} and Λπ^{-} invariant mass distributions looking for substructure in the decay Λ_{c}^{+}→Λπ^{+}π^{+}π^{-}. We find a significant signal in each mass distribution. When interpreted as resonances, we find for the Λπ^{+} (Λπ^{-}) combination a mass of 1434.3±0.6(stat)±0.9(syst)  MeV/c^{2} [1438.5±0.9(stat)±2.5(syst)  MeV/c^{2}], an intrinsic width of 11.5±2.8(stat)±5.3(syst)  MeV/c^{2} [33.0±7.5(stat)±23.6(syst)  MeV/c^{2}] with a significance of 7.5σ (6.2σ). As these two signals are very close to the K[over ¯]N threshold, we also investigate the possibility of a K[over ¯]N cusp, and find that we cannot discriminate between these two interpretations due to the limited size of the data sample.

Observation of e^{+}e^{-}→ωχ_{bJ}(1P) and Search for X_{b}→ωϒ(1S) at sqrt[s] near 10.75 GeV

We study the processes e^{+}e^{-}→ωχ_{bJ}(1P) (J=0, 1, or 2) using samples at center-of-mass energies sqrt[s]=10.701, 10.745, and 10.805 GeV, corresponding to 1.6, 9.8, and 4.7  fb^{-1} of integrated luminosity, respectively. These data were collected with the Belle II detector during special operations of the SuperKEKB collider above the ϒ(4S) resonance. We report the first observation of ωχ_{bJ}(1P) signals at sqrt[s]=10.745  GeV. By combining Belle II data with Belle results at sqrt[s]=10.867  GeV, we find energy dependencies of the Born cross sections for e^{+}e^{-}→ωχ_{b1,b2}(1P) to be consistent with the shape of the ϒ(10753) state. These data indicate that the internal structures of the ϒ(10753) and ϒ(10860) states may differ. Including data at sqrt[s]=10.653  GeV, we also search for the bottomonium equivalent of the X(3872) state decaying into ωϒ(1S). No significant signal is observed for masses between 10.45 and 10.65  GeV/c^{2}.

Measurement of the Λ_{c}^{+} Lifetime

An absolute measurement of the Λ_{c}^{+} lifetime is reported using Λ_{c}^{+}→pK^{-}π^{+} decays in events reconstructed from data collected by the Belle II experiment at the SuperKEKB asymmetric-energy electron-positron collider. The total integrated luminosity of the data sample, which was collected at center-of-mass energies at or near the ϒ(4S) resonance, is 207.2  fb^{-1}. The result, τ(Λ_{c}^{+})=203.20±0.89±0.77  fs, where the first uncertainty is statistical and the second systematic, is the most precise measurement to date and is consistent with previous determinations.

Search for a Dark Photon and an Invisible Dark Higgs Boson in μ^{+}μ^{-} and Missing Energy Final States with the Belle II Experiment

The dark photon A^{'} and the dark Higgs boson h^{'} are hypothetical particles predicted in many dark sector models. We search for the simultaneous production of A^{'} and h^{'} in the dark Higgsstrahlung process e^{+}e^{-}→A^{'}h^{'} with A^{'}→μ^{+}μ^{-} and h^{'} invisible in electron-positron collisions at a center-of-mass energy of 10.58 GeV in data collected by the Belle II experiment in 2019. With an integrated luminosity of 8.34  fb^{-1}, we observe no evidence for signal. We obtain exclusion limits at 90% Bayesian credibility in the range of 1.7-5.0 fb on the cross section and in the range of 1.7×10^{-8}-200×10^{-8} on the effective coupling ϵ^{2}×α_{D} for the A^{'} mass in the range of 4.0  GeV/c^{2}<M_{A^{'}}<9.7  GeV/c^{2} and for the h^{'} mass M_{h^{'}}<M_{A^{'}}, where ϵ is the mixing strength between the standard model and the dark photon and α_{D} is the coupling of the dark photon to the dark Higgs boson. Our limits are the first in this mass range.

Evidence of a New Excited Charmed Baryon Decaying to Σ_{c}(2455)^{0,++}π^{±}

We present the study of B[over ¯]^{0}→Σ_{c}(2455)^{0,++}π^{±}p[over ¯] decays based on 772×10^{6}  BB[over ¯] events collected with the Belle detector at the KEKB asymmetric-energy e^{+}e^{-} collider. The Σ_{c}(2455)^{0,++} candidates are reconstructed via their decay to Λ_{c}^{+}π^{∓} and Λ_{c}^{+} decays to pK^{-}π^{+}, pK_{S}^{0}, and Λπ^{+} final states. The corresponding branching fractions are measured to be B(B[over ¯]^{0}→Σ_{c}(2455)^{0}π^{+}p[over ¯])=(1.09±0.06±0.07)×10^{-4} and B(B[over ¯]^{0}→Σ_{c}(2455)^{++}π^{-}p[over ¯])=(1.84±0.11±0.12)×10^{-4}, which are consistent with the world average values with improved precision. A new structure is found in the M_{Σ_{c}(2455)^{0,++}π^{±}} spectrum with a significance of 4.2σ including systematic uncertainty. The structure is possibly an excited Λ_{c}^{+} and is tentatively named Λ_{c}(2910)^{+}. Its mass and width are measured to be (2913.8±5.6±3.8)  MeV/c^{2} and (51.8±20.0±18.8)  MeV, respectively. The products of branching fractions for the Λ_{c}(2910)^{+} are measured to be B(B[over ¯]^{0}→Λ_{c}(2910)^{+}p[over ¯])×B(Λ_{c}(2910)^{+}→Σ_{c}(2455)^{0}π^{+})=(9.5±3.6±1.6)×10^{-6} and B(B[over ¯]^{0}→Λ_{c}(2910)^{+}p[over ¯])×B(Λ_{c}(2910)^{+}→Σ_{c}(2455)^{++}π^{-})=(1.24±0.35±0.10)×10^{-5}. Here, the first and second uncertainties are statistical and systematic, respectively.

Measurement of Two-Particle Correlations of Hadrons in e^{+}e^{-} Collisions at Belle

The measurement of two-particle angular correlation functions in high-multiplicity e^{+}e^{-} collisions at sqrt[s]=10.52  GeV is reported. In this study, the 89.5  fb^{-1} of hadronic e^{+}e^{-} annihilation data collected by the Belle detector at KEKB are used. Two-particle angular correlation functions are measured in the full relative azimuthal angle (Δϕ) and three units of pseudorapidity (Δη), defined by either the electron beam axis or the event-shape thrust axis, and are studied as a function of charged-particle multiplicity. The measurement in the thrust axis analysis, with mostly outgoing quark pairs determining the reference axis, is sensitive to the region of additional soft gluon emissions. No significant anisotropic collective behavior is observed with either coordinate analyses. Near-side jet correlations appear to be absent in the thrust axis analysis. The measurements are compared to predictions from various event generators and are expected to provide new constraints to the phenomenological models in the low-energy regime.

Search for a Light Higgs Boson in Single-Photon Decays of ϒ(1S) Using ϒ(2S)→π^{+}π^{-}ϒ(1S) Tagging Method

We search for a light Higgs boson (A^{0}) decaying into a τ^{+}τ^{-} or μ^{+}μ^{-} pair in the radiative decays of ϒ(1S). The production of ϒ(1S) mesons is tagged by ϒ(2S)→π^{+}π^{-}ϒ(1S) transitions, using 158×10^{6} ϒ(2S) events accumulated with the Belle detector at the KEKB asymmetric energy electron-positron collider. No significant A^{0} signals in the mass range from the τ^{+}τ^{-} or μ^{+}μ^{-} threshold to 9.2  GeV/c^{2} are observed. We set the upper limits at 90% credibility level (C.L.) on the product branching fractions for ϒ(1S)→γA^{0} and A^{0}→τ^{+}τ^{-} varying from 3.8×10^{-6} to 1.5×10^{-4}. Our results represent an approximately twofold improvement on the current world best upper limits for the ϒ(1S)→γA^{0}(→τ^{+}τ^{-}) production. For A^{0}→μ^{+}μ^{-}, the upper limits on the product branching fractions for ϒ(1S)→γA^{0} and A^{0}→μ^{+}μ^{-} are at the same level as the world average limits, and vary from 3.1×10^{-7} to 1.6×10^{-5}. The upper limits at 90% credibility level on the Yukawa coupling f_{ϒ(1S)} and mixing angle sinθ_{A^{0}} are also given.

Measurement of Differential Branching Fractions of Inclusive B→X_{u}ℓ^{+}ν_{ℓ} Decays

The first measurements of differential branching fractions of inclusive semileptonic B→X_{u}ℓ^{+}ν_{ℓ} decays are performed using the full Belle data set of 711  fb^{-1} of integrated luminosity at the ϒ(4S) resonance and for ℓ=e, μ. With the availability of these measurements, new avenues for future shape-function model-independent determinations of the Cabibbo-Kobayashi-Maskawa matrix element |V_{ub}| can be pursued to gain new insights in the existing tension with respect to exclusive determinations. The differential branching fractions are reported as a function of the lepton energy, the four-momentum-transfer squared, light-cone momenta, the hadronic mass, and the hadronic mass squared. They are obtained by subtracting the backgrounds from semileptonic B→X_{c}ℓ^{+}ν_{ℓ} decays and other processes, and corrected for resolution and acceptance effects.

Precise Measurement of the D^{0} and D^{+} Lifetimes at Belle II

We report a measurement of the D^{0} and D^{+} lifetimes using D^{0}→K^{-}π^{+} and D^{+}→K^{-}π^{+}π^{+} decays reconstructed in e^{+}e^{-}→cc[over ¯] data recorded by the Belle II experiment at the SuperKEKB asymmetric-energy e^{+}e^{-} collider. The data, collected at center-of-mass energies at or near the ϒ(4S) resonance, correspond to an integrated luminosity of 72  fb^{-1}. The results, τ(D^{0})=410.5±1.1(stat)±0.8(syst)  fs and τ(D^{+})=1030.4±4.7(stat)±3.1(syst)  fs, are the most precise to date and are consistent with previous determinations.

Search for B^{+}→K^{+}νν[over ¯] Decays Using an Inclusive Tagging Method at Belle II

A search for the flavor-changing neutral-current decay B^{+}→K^{+}νν[over ¯] is performed at the Belle II experiment at the SuperKEKB asymmetric energy electron-positron collider. The data sample corresponds to an integrated luminosity of 63  fb^{-1} collected at the ϒ(4S) resonance and a sample of 9  fb^{-1} collected at an energy 60 MeV below the resonance. Because the measurable decay signature involves only a single charged kaon, a novel measurement approach is used that exploits not only the properties of the B^{+}→K^{+}νν[over ¯] decay, but also the inclusive properties of the other B meson in the ϒ(4S)→BB[over ¯] event, to suppress the background from other B meson decays and light-quark pair production. This inclusive tagging approach offers a higher signal efficiency compared to previous searches. No significant signal is observed. An upper limit on the branching fraction of B^{+}→K^{+}νν[over ¯] of 4.1×10^{-5} is set at the 90% confidence level.

Measurements of the Branching Fractions of the Semileptonic Decays Ξ_{c}^{0}→Ξ^{-}ℓ^{+}ν_{ℓ} and the Asymmetry Parameter of Ξ_{c}^{0}→Ξ^{-}π^{+}

Using data samples of 89.5 and 711  fb^{-1} recorded at energies of sqrt[s]=10.52 and 10.58 GeV, respectively, with the Belle detector at the KEKB e^{+}e^{-} collider, we report measurements of branching fractions of semileptonic decays Ξ_{c}^{0}→Ξ^{-}ℓ^{+}ν_{ℓ} (ℓ=e or μ) and the CP-asymmetry parameter of Ξ_{c}^{0}→Ξ^{-}π^{+} decay. The branching fractions are measured to be B(Ξ_{c}^{0}→Ξ^{-}e^{+}ν_{e})=(1.31±0.04±0.07±0.38)% and B(Ξ_{c}^{0}→Ξ^{-}μ^{+}ν_{μ})=(1.27±0.06±0.10±0.37)%, and the decay parameter α_{Ξπ} is measured to be 0.63±0.03±0.01 with much improved precision compared with the current world average. The corresponding ratio B(Ξ_{c}^{0}→Ξ^{-}e^{+}ν_{e})/B(Ξ_{c}^{0}→Ξ^{-}μ^{+}ν_{μ}) is 1.03±0.05±0.07, which is consistent with the expectation of lepton flavor universality. The first measured asymmetry parameter A_{CP}=(α_{Ξ^{-}π^{+}}+α_{Ξ[over ¯]^{+}π^{-}})/(α_{Ξ^{-}π^{+}}-α_{Ξ[over ¯]^{+}π^{-}})=0.024±0.052±0.014 is found to be consistent with zero. The first and the second uncertainties above are statistical and systematic, respectively, while the third ones arise due to the uncertainty of the Ξ_{c}^{0}→Ξ^{-}π^{+} branching fraction.

Evidence for X(3872)→J/ψπ^{+}π^{-} Produced in Single-Tag Two-Photon Interactions

We report the first evidence for X(3872) production in two-photon interactions by tagging either the electron or the positron in the final state, exploring the highly virtual photon region. The search is performed in e^{+}e^{-}→e^{+}e^{-}J/ψπ^{+}π^{-}, using 825  fb^{-1} of data collected by the Belle detector operated at the KEKB e^{+}e^{-} collider. We observe three X(3872) candidates, where the expected background is 0.11±0.10 events, with a significance of 3.2σ. We obtain an estimated value for Γ[over ˜]_{γγ}B(X(3872)→J/ψπ^{+}π^{-}) assuming the Q^{2} dependence predicted by a cc[over ¯] meson model, where -Q^{2} is the invariant mass squared of the virtual photon. No X(3915)→J/ψπ^{+}π^{-} candidates are found.

Search for Axionlike Particles Produced in e^{+}e^{-} Collisions at Belle II

We present a search for the direct production of a light pseudoscalar a decaying into two photons with the Belle II detector at the SuperKEKB collider. We search for the process e^{+}e^{-}→γa, a→γγ in the mass range 0.2<m_{a}<9.7  GeV/c^{2} using data corresponding to an integrated luminosity of (445±3)  pb^{-1}. Light pseudoscalars interacting predominantly with standard model gauge bosons (so-called axionlike particles or ALPs) are frequently postulated in extensions of the standard model. We find no evidence for ALPs and set 95% confidence level upper limits on the coupling strength g_{aγγ} of ALPs to photons at the level of 10^{-3}  GeV^{-1}. The limits are the most restrictive to date for 0.2<m_{a}<1  GeV/c^{2}.

Diagnostic Accuracy of MRI-Based Morphometric Parameters for Detecting Olfactory Nerve Dysfunction

BACKGROUND AND PURPOSE

Although olfactory dysfunction is a common cranial nerve disorder, there are no simple objective morphometric criteria to assess olfactory dysfunction. The aim of this study was to evaluate the diagnostic performance of MR imaging morphometric parameters for detecting olfactory dysfunction.

MATERIALS AND METHODS

This prospective study enrolled patients from those presenting with olfactory symptoms who underwent both an olfactory function test and MR imaging. Controls without olfactory dysfunction were recruited during the preoperative work-up for pituitary adenoma. Two independent neuroradiologists measured the olfactory bulb in 3D and assessed olfactory bulb concavity on MR imaging while blinded to the clinical data. Diagnostic performance was assessed using receiver operating characteristic curve analysis.

RESULTS

Sixty-four patients and 34 controls were enrolled. The patients were significantly older than the controls (mean age, 57.8 ± 11.9 years versus 47.1 ± 12.1 years; P < .001). Before age adjustment, the olfactory bulb height was the only olfactory bulb parameter showing a significant difference between patients and controls (1.6 ± 0.3 mm versus 2.0 ± 0.3 mm, P < .001). After age adjustment, all parameters and olfactory bulb concavity showed significant intergroup differences, with the olfactory bulb height having the highest area under the curve (0.85). Olfactory bulb height was confirmed to be the only significant parameter showing a difference in the detection of olfactory dysfunction in 22 pairs after matching for age and sex (area under the curve = 0.87, P < .001). Intraclass correlation coefficients revealed moderate-to-excellent degrees of inter- and intrareader agreement.

CONCLUSIONS

MR imaging morphometric analysis can differentiate patients with olfactory dysfunction, with the olfactory bulb height having the highest diagnostic performance for detecting olfactory dysfunction irrespective of age.

Diagnostic performance of MRI to detect metastatic cervical lymph nodes in patients with thyroid cancer: a systematic review and meta-analysis

AIM

To evaluate the diagnostic performance of magnetic resonance imaging (MRI) in the diagnosis of metastatic cervical lymph nodes.

MATERIALS AND METHODS

Ovid-MEDLINE and EMBASE databases were searched up until 12 June 2018. Eleven articles were included in the qualitative systematic review and nine of the 11 in the quantitative analysis. Two radiologists independently performed data extraction and methodological quality assessment using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. A qualitative systematic review and quantitative analysis were performed, followed by a meta-regression analysis to determine factors causing heterogeneity.

RESULTS

The pooled sensitivity and specificity in the diagnosis of metastatic cervical lymph nodes were 80% (95% confidence interval [CI]: 68-88%) and 85% (95% CI: 63-95%), respectively. The sensitivity and false-positive rate (correlation coefficient, 0.655) showed a positive correlation due to a threshold effect, which was responsible for heterogeneity across the studies, as indicated by a Q-test (p<0.01) and Higgins I² statistic (sensitivity, I²=90.11%; specificity, I²=92.49%). In the meta-regression analysis, fat-suppressed imaging, and the analysis method were significant factors influencing the heterogeneity in diagnostic performance.

CONCLUSIONS

MRI shows moderate diagnostic performance in the diagnosis of metastatic lymph nodes in patients with thyroid cancer in the neck. MRI may be an optional or complementary imaging method to ultrasound or computed tomography (CT) in thyroid cancer patients.

CT and MRI Findings of Glomangiopericytoma in the Head and Neck: Case Series Study and Systematic Review

Glomangiopericytoma is a rare sinonasal mesenchymal tumor of borderline or low malignant potential. We reviewed the CT and MR imaging findings of head and neck glomangiopericytoma via a retrospective case series study and systematic review. Our study revealed that glomangiopericytoma is a well-defined lobulated avidly enhancing soft-tissue mass with erosive bony remodeling that is most commonly found in the sinonasal cavity. Typically, it is hyperintense on T2-weighted images with vascular signal voids, has a high mean ADC value, and a wash-in and washout pattern on dynamic contrast-enhanced MR imaging. Although the CT findings are nonspecific, typical MR imaging findings, including those on the ADC map and dynamic contrast-enhanced MR imaging, may be helpful for differentiating glomangiopericytomas from other hypervascular tumors in the head and neck.

The Association between Facial Fracture Patterns and Traumatic Head Injury in Injured Motorcycle Riders According to Helmet Use Status

Objective

This study was undertaken to identify the association between facial fracture patterns and traumatic head injury in injured motorcycle riders.

Methods

Retrospective study design. We reviewed the medical records of patients who underwent facial bone computed tomography (CT) and brain CT simultaneously among the injured motorcycle riders between May 2009 and July 2011. Data collected included age, sex, Glasgow Coma Scale (GCS), Revised Trauma Score (RTS), facial fracture patterns, head protective device (helmet) use, alcohol intake, time of accident and seat position. Facial fracture patterns were grouped as upper, mid, and lower face. Traumatic head injury (THI) included skull fracture, brain haemorrhage and diffuse axonal injury.

Results

Of the 154 patients included, 138 (89.6%) were male, 57 (37%) had facial fracture, 69 (44.8%) wore helmets and 30 (19.5%) had THI. Their mean age was 29.0+15.0 years. After multivariate logistic regression analysis, THI was associated with GCS, seat position of riders and accident time. THI was correlated with the combination of upper and midfacial fractures in helmeted group and isolated upper facial fracture or the combination of upper and midfacial fractures in unhelmeted group. The rest of facial fracture patterns were not correlated with THI regardless of helmet.

Conclusions

The combination of upper and midfacial fractures are the risk factor of THI regardless of helmet. The patients with the combination of upper and midfacial fractures should be further evaluated for head injury regardless of helmet.

Observational scores of dampness and mold associated with measurements of microbial agents and moisture in three public schools

We examined associations between observational dampness scores and measurements of microbial agents and moisture in three public schools. A dampness score was created for each room from 4-point-scale scores (0-3) of water damage, water stains, visible mold, moldy odor, and wetness for each of 8 room components (ceiling, walls, windows, floor, ventilation, furniture, floor trench, and pipes), when present. We created mixed microbial exposure indices (MMEIs) for each of 121 rooms by summing decile ranks of 8 analytes (total culturable fungi; total, Gram-negative, and Gram-positive culturable bacteria; ergosterol; (1→3)-β-D-glucan; muramic acid; and endotoxin) in floor dust. We found significant (P ≤ 0.01) linear associations between the dampness score and culturable bacteria (total, Gram-positive, and Gram-negative) and the MMEIs. Rooms with dampness scores greater than 0.25 (median) had significantly (P < 0.05) higher levels of most microbial agents, MMEIs, and relative moisture content than those with lower scores (≤0.25). Rooms with reported recent water leaks had significantly (P < 0.05) higher dampness scores than those with historical or no reported water leaks. This study suggests that observational assessment of dampness and mold using a standardized form may be valuable for identifying and documenting water damage and associated microbial contamination.

Metal oxide coated lithium cobalt fluorophosphate cathode materials for lithium secondary batteries--effect of aging and temperature

Lithium cobalt fluorophosphate (Li2CoPO4F) is a promising 5 V class cathode material for lithium secondary batteries. In this study, surface coating with ZrO2 improved the electrochemical activity of Li2CoPO4F with a maximum discharge capacity of 144 mA h g(-1). The effectiveness of ZrO2 coating was evaluated using aging analysis with a commercial electrolyte, i.e., 1 M LiPF6 in EC:DMC (1:1, v/v). The metal ion dissolution was reduced to 1/8th of that observed in the non-coated Li2CoPO4F. It was found that the thin coating layer had less or no contribution to the additional resistance for the cell, both at an open circuit potential and at a fully charged state; hence, the capacity of the cell was retained over cycling. Elevated temperature aging did not affect the intrinsic property of the coated Li2CoPO4F, as observed from the complete anodic and cathodic peaks from cyclic voltammetry studies after 30 days of storage at 50 degrees C. An increase in impedance was observed for aged cells, which could be due to the thick SEI layer formed during storage. The ZrO2 coating over Li2CoPO4F was crucial for the improved performance of electrode active material at higher operating potentials of up to 5.2 V.

Docking-based 3D-QSAR study of pyridyl aminothiazole derivatives as checkpoint kinase 1 inhibitors

Checkpoint kinase 1 (Chk1) is a promising target for the design of novel anticancer agents. In the present work, molecular docking simulations and three-dimensional quantitative structure-activity relationship (3D-QSAR) studies were performed on pyridyl aminothiazole derivatives as Chk1 inhibitors. AutoDock was used to determine the probable binding conformations of all the compounds inside the active site of Chk1. Comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) models were developed based on the docking conformations and alignments. The CoMFA model produced statistically significant results with a cross-validated correlation coefficient (q2) of 0.608 and a coefficient of determination (r2) of 0.972. The reliable CoMSIA model with q2 of 0.662 and r2 of 0.970 was obtained from the combination of steric, electrostatic and hydrogen bond acceptor fields. The predictive power of the models were assessed using an external test set of 14 compounds and showed reasonable external predictabilities (r(2)pred) of 0.668 and 0.641 for CoMFA and CoMSIA models, respectively. The models were further evaluated by leave-ten-out cross-validation, bootstrapping and progressive scrambling analyses. The study provides valuable information about the key structural elements that are required in the rational design of potential drug candidates of this class of Chk1 inhibitors.

Impact of internal spermatic artery preservation during laparoscopic varicocelectomy on recurrence and the catch-up growth rate in adolescents

OBJECTIVE

To investigate the effectiveness of laparoscopic varicocelectomy (LV) in adolescents with varicocele and analyze the impact of internal spermatic artery (ISA) preservation on surgical outcomes.

MATERIALS AND METHODS

Data on 92 adolescents with left varicocele who underwent LV between December 1998 and January 2011 were retrospectively analyzed. The mean age of the patients was 13.2 ± 2.1 years. Age, grade of disease, number of ligation veins, recurrence rates, and catch-up growth were analyzed in patients who underwent ISA preservation and ligation. The median duration of the follow-up was 21 months.

RESULTS

ISA preservation was performed on 50 patients (54%). There were no significant inter-group differences in terms of age, varicocele grade, number of ligation veins, and catch-up growth (93% vs. 90%). The patients who received artery preservation demonstrated a higher recurrence rate (22%) than those who received artery ligation (5%; p = 0.032). Among 13 patients who had persistent or recurrent varicocele, nine were treated with embolization and one was treated with magnification-assisted subinguinal varicocelectomy. None of these 10 patients demonstrated recurrence or testicular atrophy.

CONCLUSIONS

LV with ISA ligation can reduce the recurrence rate and results in the same catch-up growth rate in comparison with LV with ISA preservation.

High-resolution impedance manometry facilitates assessment of pharyngeal residue and oropharyngeal dysphagic mechanisms

The utility of high-resolution impedance manometry (HRIM) for evaluating oropharyngeal dysphagia (OPD) has been investigated. These approaches are limited because of the sophisticated methodology. A method of transforming HRIM into a simple and useful diagnostic tool for evaluating OPD is needed. A videofluoroscopic swallowing study (VFSS) and HRIM were performed by independent blinded examiners in 26 consecutive healthy volunteers (12 men; median age, 56.5 years) and 10 OPD patients (five men; median age, 59.5 years). Upper esophageal sphincter (UES) relaxation parameters were measured using a standard HRIM protocol. Peristalsis and bolus transit of the pharyngoesophageal (PE) segment were assessed using an HRIM-modified protocol in which the catheter was pulled back 10 cm. PE bolus transits were evaluated with an impedance contour pattern (linear vs. stasis) method. A significant difference was observed between the manometric measures of healthy volunteers and OPD patients for only the duration of pharyngeal contraction (0.49 ± 0.19 vs. 0.76 ± 0.33 s, P = 0.04). The percentage agreement and kappa value for detecting pharyngeal residue between the VFSS and the impedance analysis were 100% and 1.00, respectively. HRIM allowed for comprehensive assessment of abnormal pharyngeal components that caused pharyngeal residue on VFSS in two patients; reduced base of the tongue versus weak pharyngeal contraction in one, and reduced relaxation of the UES versus reduced laryngeal elevation in the remaining patient. Our findings demonstrated that HRIM using a simple methodology (i.e., pull-back of the catheter) detected pharyngeal residue through a simple analysis of the impedance contour pattern (linear vs. stasis). Furthermore, HRIM facilitated a comprehensive assessment of OPD mechanisms and recognition of subtle abnormalities not yet visible to the naked eye on VFSS.

Long-term metformin use reduces gastric cancer risk in type 2 diabetics without insulin treatment: a nationwide cohort study

BACKGROUND

Metformin use has been associated with a decreased incidence and mortality of various cancers.

AIM

To evaluate the association between metformin use and gastric cancer.

METHODS

We randomly selected 100 000 type 2 diabetic patients from the 2004 Korean National Health Insurance claim database, and assessed gastric cancer incidence among 39 989 patients (aged 30-97 years) who were regularly treated with anti-diabetic drugs and followed-up from 2004 to 2010. In total, 26 690 patients had used metformin out of 32 978 diabetics who had not regularly used insulin (insulin non-users), and 5855 patients had used metformin out of 7011 regular insulin users.

RESULTS

Patients who used metformin showed a lower incidence of gastric cancer than those who did not use metformin, in insulin non-users (P = 0.047, log-rank test). However, in patients on regular insulin, there was no difference of gastric cancer incidence according to metformin use. In insulin non-users, the adjusted hazard ratio (AHR) for metformin use was 0.73 (95% confidential interval [CI], 0.53-1.01) with borderline statistical significance (P = 0.059). Duration of metformin use was associated with the reduction in gastric cancer risk (AHR, 0.88; 95% CI 0.81-0.96, P = 0.003), especially in patients who used metformin for more than 3 years (AHR, 0.57; 95% CI, 0.37-0.87; P = 0.009).

CONCLUSION

Metformin use >3 years in type 2 diabetics who do not use insulin is associated with a significantly reduced gastric cancer risk.

Pelvic congestion syndrome diagnosed using endoscopic ultrasonography

Pelvic congestion syndrome (PCS) presents with a non-cyclic pelvic pain lasting more than six months in duration in premenopausal women. Pelvic ultrasonography or computed tomography is usually the first imaging modality used to evaluate patients with suspected PCS. PCS is confirmed by visible congestion of the pelvic veins on selective ovarian venography. To our knowledge, the role of endoscopic ultrasonography (EUS) has not been reported. EUS showed multiple dilated structures especially on left side around the uterus and ovaries, which are compatible with other radiological investigations of PCS Although PCS is not typical areas within the scope of practice of endosonographers, it is useful to be familiar with the findings. We report a case of PCS that was diagnosed with the aid of EUS.

Staging of intestinal- and diffuse-type gastric cancers with the OLGA and OLGIM staging systems

BACKGROUND

Operative link on gastritis assessment (OLGA) and Operative link on gastric intestinal metaplasia assessment (OLGIM) staging systems have been proposed for gastric cancer (GC) risk estimation.

AIM

To validate the OLGA and OLGIM staging systems in a region with high risk of GC.

METHODS

This retrospective study included 474 GC patients and age- and sex-matched health screening control persons in a cancer centre hospital. We classified gastritis patterns according to the OLGA and OLGIM systems using the histological database that a pathologist prospectively evaluated using the updated Sydney system. GC risk according to the OLGA and OLGIM stages was evaluated using logistic regression analysis.

RESULTS

More GC patients had OLGA stages III-IV (46.2%) than controls (26.6%, P < 0.001), particularly among patients with intestinal-type GCs (62.2%) compared with diffuse-type GCs (30.9%). OLGA stages III and IV were significantly associated with increased risk of GC [odds ratios (ORs), 2.09; P = 0.008 and 2.04; P = 0.014 respectively] in multivariate analysis. The association was more significant for intestinal-type (ORs, 4.76; P = 0.001 and 4.19; P = 0.002 respectively), but not diffuse-type GC. OLGIM stages from I to IV were significantly associated with increased risk of both intestinal-type (ORs, 3.64, 5.15, 7.89 and 13.20 respectively) and diffuse-type GC (ORs, 1.84, 2.59, 5.08 and 6.32 respectively) with a significantly increasing trend.

CONCLUSION

As high OLGA and OLGIM stages are independent risk factors for gastric cancer, the staging systems may be useful for risk assessment in high-risk regions, especially for intestinal-type gastric cancer.

Randomised clinical trial: the effects of Helicobacter pylori eradication on glandular atrophy and intestinal metaplasia after subtotal gastrectomy for gastric cancer

BACKGROUND

Helicobacter pylori eradication is recommended for early gastric cancer (GC) patients after resection.

AIM

To evaluate whether H. pylori eradication improves glandular atrophy and intestinal metaplasia (IM) in GC patients undergoing subtotal gastrectomy.

METHODS

This randomised, double-blind trial was performed in tertiary care setting. Distal GC patients with H. pylori infection were randomised to receive proton pump inhibitor-based triple therapy or placebo. The histology was evaluated using the updated Sydney system before and at 36 months after surgery. The endpoints were the comparison of atrophy and IM score changes between the allocated groups and according to final H. pylori status.

RESULTS

Overall, 190 patients were randomised to the treatment and placebo groups. For lesser curvature of the corpus, mean atrophy and IM scores did not differ between the treatment and placebo groups. However, the H. pylori-eradicated patients had significantly lower mean scores than the H. pylori-persistent patients regarding atrophy (0.55 ± 0.95 vs. 1.05 ± 1.10 respectively; P = 0.0046) and IM (0.66 ± 0.99 vs. 1.05 ± 1.16 respectively; P = 0.0284). The percentage change from baseline was more marked in the H. pylori-negative than in the H. pylori-positive groups (-58.6% vs. -11.0% for atrophy and -60.5% vs. -35.6% for IM respectively). For greater curvature, mean atrophy score was lower in the H. pylori-negative group than in the H. pylori-positive group (0.14 ± 0.50 vs. 0.41 ± 0.75 respectively; P = 0.0281). The percentage change was -36.4% vs. 86.3%.

CONCLUSION

Helicobacter pylori eradication in GC patients is beneficial, as reflected by lower scores of atrophy and IM at 36 months after subtotal gastrectomy. (ClinicalTrials.gov number, NCT01002443).

Extraskeletal myxoid chondrosarcoma of the neck

Extraskeletal myxoid chondrosarcoma is a rare malignant soft-tissue tumour that is typically in the deep soft tissues of the lower extremity. The tumour is usually a well-defined, multinodular soft-tissue mass without calcifications. A 62-year-old woman with a history of nasopharyngeal cancer presented with a palpable mass in the anterior neck. Radiologically, the lesion was a well-defined soft-tissue mass with the extensive calcifications on various imaging examinations. Although this lesion was histopathologically diagnosed as extraskeletal myxoid chondrosarcoma, the unusual imaging findings were challenging and very intriguing.

Effect of chemotherapy on the outcome of self-expandable metallic stents in gastric cancer patients with malignant outlet obstruction

BACKGROUND AND STUDY AIM

Chemotherapy has been suggested to affect the outcome of pyloric stent placement. This study aimed to investigate the association between the response to chemotherapy and pyloric stent outcome.

PATIENTS AND METHODS

Data from 113 patients with inoperable gastric cancer who received chemotherapy after pyloric stent placement at the National Cancer Center hospital were analyzed retrospectively. Chemotherapy response was assessed using the Response Evaluation Criteria in Solid Tumors. A Cox proportional hazards model was used to evaluate the effect of chemotherapy response on the complications of stents.

RESULTS

The stent migration rate was 15.9% (18/113) and the re-stenosis rate was 30.1% (34/113). The response rates to chemotherapy were higher in the first-line group than in the salvage chemotherapy group (second-line or more) (44.8% [26/58] vs. 3.6% [2/55], respectively; P < 0.001). The proportion of patients with long time-to-progression (> 8 weeks) was also higher in the first-line than the salvage chemotherapy group (81.0% [47 /58] vs. 61.8% [34 /55], respectively; P = 0.036). Although, the response to chemotherapy was not associated with stent migration or re-stenosis, a long time-to-progression (adjusted hazard ratio [aHR] = 0.29, 95% confidence interval [CI] 0.13-0.67) and first-line chemotherapy (aHR = 0.45, 95%CI 0.22-0.93) were protective factors against re-stenosis in the multivariate analysis. In patients who received first-line chemotherapy, the median duration of patency of covered and uncovered stents was 20 weeks (95%CI 11-29) and 33 weeks (95 %CI 18-48), respectively (P = 0.317).

CONCLUSIONS

A long time-to-progression and first-line chemotherapy were significant protective factors against re-stenosis. In chemotherapy-naïve gastric cancer patients with pyloric obstruction, placement of an uncovered stent followed by chemotherapy can be considered to increase stent patency.

Effects of Liver Function on Ionized Hypocalcaemia following Rapid Blood Transfusion

OBJECTIVE: Hypocalcaemia detrimentally affects the cardiovascular system and massive transfusion-related hypocalcaemia is particularly severe in end-stage liver disease patients undergoing liver transplantation (LT). This study, therefore, compared the severity and duration of ionized hypocalcaemia between patients with normal and impaired liver function. METHODS: Patients ( n = 26 per group) were transfused at a rate of 10 ml/kg within 10 min with packed red blood cells (PRBCs) during LT (group LP) or spinal surgery (group SP), or were infused with 0.9% normal saline during spinal surgery (group SN). Serum levels of ionized calcium were assessed before (T0), just after (T1), and at 20 (T2) and 60 min (T3) after transfusion. RESULTS: Transfusion with PRBCs caused more severe ionized hypocalcaemia than 0.9% normal saline at T1. In contrast to the faster (20 min) normalization in group SP, ionized hypocalcaemia in group LP persisted at T3. Serum ionized calcium levels at T3 showed correlations with vital signs, blood glucose, serum potassium, base deficit and lactate. CONCLUSION: Rapid blood transfusion caused more severe and prolonged ionized hypocalcaemia in patients with liver dysfunction than in those with normal liver function.

Aspirin use and bleeding risk after endoscopic submucosal dissection in patients with gastric neoplasms

BACKGROUND AND STUDY AIM

The risk of bleeding after endoscopic submucosal dissection (ESD) in patients with early gastric neoplasms who do not discontinue aspirin for the procedure has not been established. We aimed to investigate whether post-ESD gastric bleeding is increased in patients who take aspirin.

PATIENTS AND METHODS

Patients who underwent ESD for early gastric neoplasms at the National Cancer Center Hospital, Korea, between November 2008 and January 2011 were enrolled. The risk of post-ESD bleeding was evaluated using Poisson regression analysis.

RESULTS

We categorized 514 patients into three groups according to aspirin intake at the time of the procedure: patients who never used aspirin (n=439), patients who interrupted aspirin use for 7 days or more (n=56), and patients who continuously used aspirin (n=19). Post-ESD bleeding occurred in 4.1% (21/514) overall, and was more frequent in continuous aspirin users (4/19 [21.1%]) than in those who never used aspirin (15/439 [3.4%]) (P=0.006) and those with interrupted aspirin use (2/56 [3.6%]) (P=0.033). Multivariate analysis showed that use of aspirin by itself was associated with post-ESD bleeding (relative risk [RR] 4.49; 95% confidence interval [95%CI] 1.09-18.38). The resumption of clopidogrel combined with aspirin use (RR 26.71, 95%CI 7.09-100.53), and increased iatrogenic ulcer size (RR 1.52, 95%CI 1.14-2.02), were significantly associated with post-ESD bleeding.

CONCLUSIONS

Continuous aspirin use increases the risk of bleeding after gastric ESD. Aspirin use should be stopped in patients with a low risk for thromboembolic disease to minimize bleeding complications.

Levels of microbial agents in floor dust during remediation of a water-damaged office building

We examined the effects of remediation on loads of culturable fungi in floor dust collected from a large water-damaged office building during four cross-sectional surveys (2002, 2004, 2005, and 2007, respectively). We created a binary remediation variable for each year for each sampled workstation using information on remediation associated with water damage obtained from building management and used generalized linear mixed-effects models. We found significantly lower levels of culturable total and hydrophilic fungi at remediated workstations than at non-remediated workstations in 2004 and 2005 after completion of major remediation. The remediation effect, however, disappeared in 2007. The fraction of hydrophilic to total fungal concentrations was lowest in 2004, increased in 2005, and was highest in 2007. Our results indicate that the 2003 remediation lowered dust indices of dampness temporarily, but remediation was incomplete, consistent with a building assessment report of water infiltration. This study demonstrates the utility of longitudinal evaluation of microbial indices during remediation of water damage in this building, in which elimination of sources of moisture was not fully addressed. Our findings indicate that the fraction of hydrophilic fungi derived from concentrations of fungal species may be a useful index for assessing the long-term effectiveness of remediation.

PRACTICAL IMPLICATIONS

This study demonstrates the utility of longitudinal evaluation of microbial indices during remediation of water damage in this building, in which elimination of sources of moisture was incomplete. Our findings indicate that the fraction of hydrophilic fungi derived from concentrations of fungal species may be a useful index for assessing the long-term effectiveness of remediation.

Comparison of surgical performance and short-term clinical outcomes between laparoscopic and robotic surgery in distal gastric cancer

AIMS

The authors aimed to compare the surgical performance and the short-term clinical outcomes of robotic assisted laparoscopic distal gastrectomy (RADG) with laparoscopy-assisted distal gastrectomy (LADG) in distal gastric cancer patients.

METHOD

From April 2009 to August 2010, 62 patients underwent LADG and 30 patients underwent RADG for preoperative stage I distal gastric cancer by one surgeon at the National Cancer Center, Korea. Surgical performance was measured using lymph node (LN) dissection time and number of retrieved LNs, which were viewed as surrogates of technical ease and oncologic quality.

RESULTS

In clinicopathologic characteristics, mean age, depth of invasion and stage were significantly different between the LADG and RADG group. Mean dissection time at each LN station was greater in the RADG group, but no significant intergroup difference was found for numbers of retrieved LNs. Furthermore, proximal resection margins were smaller, and hospital costs were higher in the RADG group. In terms of the RADG learning curve, mean LN dissection time was smaller in the late RADG group (n = 15) than in the early RADG group (n = 15) for 4sb/4d, 5, 7-12a stations, but numbers of retrieved LNs per station were similar.

CONCLUSION

With the exception of operating time and cost, the numbers of retrieved LNs and the short-term clinical outcomes of RADG were found to be comparable to those of LADG, despite the surgeon's familiarity with LADG and lack of RADG experience. Further studies are needed to evaluate objectively ergonomic comfort and to quantify the patient benefits conferred by robotic surgery.

A low dielectric study on hybrid plasma-polymer thin films of different ratio between toluene and TEOS

Organic-inorganic hybrid co-polymer thin films were deposited on silicon(100) substrates under the several ratio of TEOS (tetraethoxysilane) against toluene by plasma enhanced chemical vapour deposition (PECVD) method. Toluene and TEOS were utilized as organic and inorganic precursors each, and hydrogen and argon were also used as a bubbler and carrier gases, respectively. In order to compare the difference of the electrical and the mechanical properties of the plasma polymerized thin films, we grew the hybrid co-polymer thin films under the conditions of various ratio between toluene and TEOS with fixed RF (radio frequency using 13.56 MHz) powers at 30 W. The as-grown polymerized thin films were in first analyzed by FT-IR and XPS. The result of FT-IR showed that the co-polymer thin films were polymerized with fragmented each precursor. Also, XPS results showed the chemical species and binding energies of each species. Si 2p core-level spectra from the hybrid polymer thin film showed the status of Si oxidation number. Impedance analyzer was utilized for the measurements of I-V curves and capacitance values. Also, the thin films were analyzed for hardness and Young's modulus by nano-indenter.

Risk of high-grade dysplasia or carcinoma in gastric biopsy-proven low-grade dysplasia: an analysis using the Vienna classification

BACKGROUND AND AIMS

Therapeutic guidelines have not yet been established for low-grade gastric adenomas/dysplasias (LGD), which have a low risk of progression to high-grade adenomas/dysplasias (HGD) or to invasive carcinomas. This study aimed to evaluate risk factors for HGD/carcinoma that indicate a need for resection in biopsy-proven LGD lesions.

PATIENTS AND METHODS

In total, 236 LGD lesions from 208 consecutive patients treated with endoscopic resection (ER) were retrospectively studied between 2004 and 2008. The Vienna classification was used for histological diagnosis. A generalized estimating equation (GEE) logistic regression model was used for multivariate analysis.

RESULTS

Among the 236 LGD lesions, the final pathology diagnosed 9 (3.8 %) as invasive carcinoma (category 5), 71 (30.1 %) as HGD (category 4), 148 (62.7 %) as LGD (category 3), and 8 (3.4 %) as negative/indefinite for dysplasia (category 1/2). Lesions ≥ 1 cm were classified as HGD/carcinoma in 39.4 % of patients (65/165). Multivariate analysis indicated that size of ≥ 1 cm (OR 1.93 [95 % CI, 1.06 - 3.52]), depressed morphology (OR 3.81 [95 % CI, 1.22 - 11.9]), and erythema (OR 2.49 [95 % CI, 1.31 - 4.72]) were significantly associated with HGD/carcinoma. The OR increased to 47.6 (95 % CI, 4.27 - 530.65) when the risk factors were all positive. The sensitivity and negative predictive value for ≥ 1 risk factors were 93.8 % and 90.9 %, respectively. As the number of risk factors of a lesion increased, the specificity and positive predictive value also increased.

CONCLUSIONS

Endoscopic resection can be recommended if a low-grade dysplastic lesion has at least one of the following risk factors: depressed morphology, surface erythema, or a size of 1 cm or greater. For lesions that have none of the three risk factors, follow-up endoscopy is recommended.

CYP2A6 and ERCC1 polymorphisms correlate with efficacy of S-1 plus cisplatin in metastatic gastric cancer patients

Background:

We evaluated the association between polymorphisms of cytochrome P450 2A6 (CYP2A6)/excision repair cross-complementation group 1 (ERCC1)/X-ray repair cross-complementing group 1(XRCC1) and treatment outcomes of metastatic gastric cancer (MGC) patients treated with S-1/cisplatin.

Methods:

Among MGC patients (n=108), who received S-1 (40 mg m⁻² b.i.d., days 1–14) and cisplatin (60 mg m⁻², day 1) every 3 weeks, we analysed the wild-type allele (W) and variants (V) of CYP2A6 (*4, *7, *9, *10), and the polymorphisms of ERCC1 (rs11615, rs3212986) and XRCC1 (rs25487).

Results:

Patients having fewer CYP2A6 variants had better response rates (W/W vs W/V other than *1/*4 vs V/V or *1/*4=66.7 vs 58.3 vs 32.3% P=0.008), time to progression (TTP) (7.2 vs 6.1 vs 3.5 months, P=0.021), and overall survival (23.2 vs 15.4 vs 12.0 months, P=0.004). ERCC1 19442C>A (rs3212986) was also associated with response rate (C/C, 46.7% vs C/A, 55.3% vs A/A, 87.5%) (P=0.048) and TTP (4.4 vs 7.6 vs 7.9 months) (P=0.012). Patients carrying both risk genotypes of CYP2A6 (V/V or 1/*4) and ERCC1 19442C>A (C/C) vs those carrying none showed an adjusted odds ratio of 0.113 (P=0.004) for response, and adjusted hazard ratios of 3.748 (P=0.0001) for TTP and 2.961 (P=0.006) for death.

Conclusion:

Polymorphisms of CYP2A6 and ERCC1 19442C>A correlated with the efficacy of S-1/cisplatin.

Detection and characterization of enterovirus associated with herpangina and hand, foot, and mouth disease in Seoul, Korea

BACKGROUND

Human enteroviruses (HEVs) are a major cause of herpangina, HFMD (hand, foot, and mouth disease), and other neurological diseases in Seoul, Korea.

METHODS

A total of 56 specimens from hospitalized patients collected from February to December 2009 (37 females and 19 males) in Seoul were tested for HEV from stool, throat swab, and vesicle swab samples taken from patients with herpangina or HFMD using cell culture and RT-PCR in 2009. By the 1D gene, encoding the VP1 capsid protein, seven different HEV genotypes were detected with Coxsackievirus A2, A4, A5, A9, A16 (CA), Coxsackievirus B1 (CB), and Enterovirus 71 (EV71). The most prevalent genotype was CA16 (6, 10.7%), followed by CA2 (4, 7.1%), CA5 (4, 7.1%), EV71 (2, 3.6%), CA4 (1, 1.8%), CA9 (1, 1.8%), and CB1 (1, 1.8%). The 1D gene sequences of two EV71 strains were closely related with one another (98.5% nucleotide similarity) and belonged to the C4 genotype.

CONCLUSIONS

It is important to continuously survey the genetic characteristics of EV71 and CA16 from patients, which will provide useful data that aids in our understanding of HFMD infections in Seoul, Korea and may contribute to future control.

Viral agents associated with acute gastroenteritis in Seoul, Korea

BACKGROUND

The present study was carried out to describe the epidemiologic characteristics of viral gastroenteritis and determine the phylogenetic composition of norovirus strains detected in hospitalized children with acute gastroenteritis in Seoul, Korea.

METHODS AND RESULTS

In total, 10,603 stool samples were collected from 2004 to 2008 and tested by RT-PCR or ELISA. In 4,170 (39.3%) samples at least one viral pathogen was present. Rotavirus (RoV) (1,864, 17.5%) was found to be the causative agent followed by norovirus (NoV) (1,845, 17.4%), human adenovirus (HAdV) (266, 2.5%), human astrovirus (HAstV) (194, 1.8%), and sapovirus (SV) (1, 0.009%). Five GI genotypes (GI-1, GI-3, GI-4, GI-8, and GI-9) and eight GII genotypes (GII-2, GII-3, GII-4, GII-6, GII-7, GII-12, GII-16, and GII-17) of NoV were identified in acute gastroenteritis patients in 2008.

CONCLUSIONS

The genetic characteristics of norovirus and the epidemiologic patterns of a viral pathogen from acute gastroenteritis patients may give potentially effective data for epidemiological studies in Seoul, Korea.

Phase II study of a triplet regimen of S-1 combined with irinotecan and oxaliplatin in patients with metastatic gastric cancer: clinical and pharmacogenetic results

BACKGROUND

The aim of this study was to investigate the efficacy and safety of S-1/irinotecan/oxaliplatin (TIROX) in metastatic gastric cancer (MGC) and the association between treatment outcome and uridine diphosphate-glucuronosyltransferase (UGT) 1A polymorphisms.

PATIENTS AND METHODS

Patients with previously untreated MGC received S-1 40 mg/m(2) b.i.d. on days 1-14 and irinotecan 150 mg/m(2) plus oxaliplatin 85 mg/m(2) on day 1 every 3 weeks.

RESULTS

Forty-four patients were enrolled. In intent-to-treat analysis, the objective response rate was 75%, including the complete response (CR) rate of 14%. The median time to progression and overall survival was 10.2 and 17.6 months, respectively. Ten (26%) of the 39 patients with primary gastric tumor showed biopsy-confirmed gastric CR. Grade 3/4 neutropenia developed in 66% of patients and grade 3 febrile neutropenia in 16%. The most common grade 3 nonhematologic toxic effects were abdominal pain (18%), anorexia (16%), and diarrhea (14%). UGT1A polymorphisms were associated with significantly higher incidence of grade 4 leukopenia (UGT1A1*6), neutropenia (UGT1A1*6, UGT1A6*2, and UGT1A7*3), grade 3/4 febrile neutropenia (UGT1A1*6), and grade 3 abdominal pain (UGT1A1*6).

CONCLUSIONS

The TIROX regimen induced marked tumor reduction and promising survival with a manageable toxicity profile in MGC patients. UGT1A genotype may be predictive of TIROX toxicity.

Intracerebroventricular and intravenous administration of growth hormone secretagogue L-692,585, somatostatin, neuropeptide Y and galanin in pig: dose-dependent effects on growth hormone secretion

Central regulation of growth hormone (GH) secretion by the GH secretagogue, L-692,585 (585), was determined in Yorkshire barrows (40-45kg BW) with intracerebroventricular (icv) stainless steel cannulas placed by stereotaxic coordinates and indwelling external jugular vein (iv) cannulas for injecting 585 or saline during 3h serial blood sampling. Dose-dependent effects of 585 were determined by icv injections of saline vehicle, 3, 10, and 30microg/kg BW by once daily increment. A switchback study of iv and icv 585 treatment determined central and peripheral regulation of GH secretion by the secretagogue at 30microg/kg BW. When administered icv, 585 increased GH concentration in a dose-dependent manner, with a return to baseline by 60min. GH secretion was attenuated by increased numbers of icv 585 injections (p<0.05); however, it was not affected by increased numbers of iv 585 injections. Icv administration of somatostatin (SRIF) decreased (p<0.05) GH secretion compared with saline-treated controls, and decreased (p<0.05) peak GH response when given in combination with 585 as compared with 585 alone. Porcine galanin (pGAL) modestly increased (p<0.05) GH levels compared with saline controls, but when given icv in combination with 585 peak GH response was lower (p<0.05) compared with 585 alone. Porcine neuropeptide Y (pNPY) administered icv was without effect on GH levels compared with saline controls and decreased (p<0.05) peak GH response when given in combination with 585 as compared with 585 alone. The pharmacological actions by icv administration indicate that the GH secretagogue and neuropeptides act at the level of both porcine pituitary and hypothalamus.