First Observation of an Attractive Interaction between a Proton and a Cascade Baryon

This Letter presents the first experimental observation of the attractive strong interaction between a proton and a multistrange baryon (hyperon) Ξ^{-}. The result is extracted from two-particle correlations of combined p-Ξ^{-}⊕p[over ¯]-Ξ[over ¯]^{+} pairs measured in p-Pb collisions at sqrt[s_{NN}]=5.02  TeV at the LHC with ALICE. The measured correlation function is compared with the prediction obtained assuming only an attractive Coulomb interaction and a standard deviation in the range [3.6, 5.3] is found. Since the measured p-Ξ^{-}⊕p[over ¯]-Ξ[over ¯]^{+} correlation is significantly enhanced with respect to the Coulomb prediction, the presence of an additional, strong, attractive interaction is evident. The data are compatible with recent lattice calculations by the HAL-QCD Collaboration, with a standard deviation in the range [1.8, 3.7]. The lattice potential predicts a shallow repulsive Ξ^{-} interaction within pure neutron matter and this implies stiffer equations of state for neutron-rich matter including hyperons. Implications of the strong interaction for the modeling of neutron stars are discussed.

Metastasis of carcinoma ex pleomorphic adenoma to the brain without previous metastasis to the lungs or bones: a case report

Carcinoma ex pleomorphic adenoma is a rare type of cancer of the salivary gland that involves the malignant transformation of a primary or recurrent pleomorphic adenoma, which often metastasises to the lungs or bones, or both. To the best of our knowledge, however, nobody has reported a distant metastasis of this lesion to the brain without such previous metastasis. We report a case in a 64-year-old man.

Intravoxel incoherent motion perfusion in patients with Moyamoya disease: comparison with 15O-gas positron emission tomography

Background

Intravoxel incoherent motion magnetic resonance imaging (IVIM) enables non-invasive measurement of brain perfusion.

Purpose

To investigate whether IVIM could be used to evaluate the hemodynamic disturbance of Moyamoya disease (MMD) by comparison with the gold-standard ¹⁵O-gas positron emission tomography (PET) method.

Material and Methods

Ten consecutive patients with MMD (six women; mean age = 42.8 years) and 10 age-matched healthy controls were evaluated by diffusion-weighted images with 12 different b values in the range of 0–900 s/mm² and ¹⁵O-gas PET. Tomographic maps of IVIM parameters, perfusion fraction (f ), pseudo-diffusion coefficient (D*), and f・D*, as well as cerebral blood volume (CBV), cerebral blood flow (CBF), and mean transit time (MTT) maps obtained with PET, were normalized and hemispheric gray and white matter values were calculated. IVIM parametric values were compared with PET parameters and with clinically assessed disease severity.

Results

There was significant correlation between D* and MTT (r = –0.74, P < 0.001) and between f・D* and CBF (r = 0.52, P = 0.02) in the cortical areas. The f values in the white matter were significantly higher in symptomatic MMD patients than in healthy controls (P = 0.01).

Conclusion

IVIM may be used to non-invasively investigate cerebral hemodynamic impairment in patients with MMD. Further evaluation is needed to establish IVIM usage in clinical settings.

Azimuthal Anisotropy of Heavy-Flavor Decay Electrons in p-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

Angular correlations between heavy-flavor decay electrons and charged particles at midrapidity (|η|<0.8) are measured in p-Pb collisions at sqrt[s_{NN}]=5.02  TeV. The analysis is carried out for the 0%-20% (high) and 60%-100% (low) multiplicity ranges. The jet contribution in the correlation distribution from high-multiplicity events is removed by subtracting the distribution from low-multiplicity events. An azimuthal modulation remains after removing the jet contribution, similar to previous observations in two-particle angular correlation measurements for light-flavor hadrons. A Fourier decomposition of the modulation results in a positive second-order coefficient (v_{2}) for heavy-flavor decay electrons in the transverse momentum interval 1.5<p_{T}<4  GeV/c in high-multiplicity events, with a significance larger than 5σ. The results are compared with those of charged particles at midrapidity and those of inclusive muons at forward rapidity. The v_{2} measurement of open heavy-flavor particles at midrapidity in small collision systems could provide crucial information to help interpret the anisotropies observed in such systems.

Unraveling Specific Brain Microstructural Damage in Moyamoya Disease Using Diffusion Magnetic Resonance Imaging and Positron Emission Tomography

BACKGROUND AND PURPOSE

Chronic ischemia may induce brain microstructural damage and lead to neurocognitive dysfunction in patients with Moyamoya disease (MMD). We applied neurite orientation dispersion and density imaging (NODDI) and ¹⁵O-gas positron emission tomography (PET) to elucidate the specific ischemic brain microstructural damage of MMD in the cortex and the white matter.

MATERIALS AND METHODS

Thirty-one patients (16-63years old, 9 males) and 20 age- and sex-matched normal controls were enrolled in this study. NODDI evaluates quantitative parameters reflecting neurite and axonal density, network complexity and the interstitial fluid in all participants. Of 31 patients, 12 newly diagnosed patients were evaluated with PET, also. We evaluated correlations between the microstructural parameters of NODDI and the hemodynamic and metabolic parameters of PET, the relationship between NODDI and clinical severity of each hemisphere (Normal, Asymtpomatic, Symptomatic, and Infarcted) as well as neurocognitive performance.

RESULTS

All NODDI parameters significantly correlated with PET parameters (absolute r = 0.46-0.83, P ≤ .048) and clinical severity (P < .001), suggesting that neurite and axonal density and network complexity decreased, and the interstitial fluid increased, as the ischemic burden became severe. NODDI parameters reflecting neurite and axonal density and network complexity significantly correlated with neurocognitive profiles (r = 0.36-0.64, P ≤ .048), but the interstitial fluid component did not.

CONCLUSIONS

Chronic ischemia in patients with MMD may induce decreased neurite and axonal density, simplified network complexity, and may lead to neurocognitive dysfunction. The increased interstitial fluid accompanying hemodynamic impairment may not be identical to the decreased neurite density and might be driven by another mechanism.

Effect of adenovirus E1A on ICAM-1 promoter activity in human alveolar and bronchial epithelial cells

In previous studies we demonstrated that the E1A DNA and proteins of group C adenovirus are present in excess in the lungs of patients with chronic obstructive pulmonary disease (COPD). Because adenovirus EIA gene products are known to regulate the expression of many genes by interacting with cellular transcription factors, we postulated that E1A enhances the production of inflammatory mediators and exacerbates the inflammatory process in smokers' lungs. We reported that LPS-induced ICAM-1 expression in A549 cells is upregulated by E1A. In the current study we investigated whether this regulation is mediated through the ICAM-1 promoter. A549 cells and primary human bronchial epithelial (HBE) cells were transiently cotransfected with a plasmid containing the ICAM-1 enhancer-promoter linked to the chloramphenicol acetyltransferase (CAT) reporter gene (pBS-CAT-P) and either a plasmid carrying the adenovirus 5 E1A gene (pE1Aneo) or a control plasmid (pneo). To compare the effect of transient versus stable E1A expression on the activity of this promoter, we also transiently transfected stable E1A-expressing A549 cells with pBS-CAT-P. Transient cotransfection of pE1Aneo and pBS-CAT-P had no effect on basal ICAM-1 promoter activity in A549 or HBE cells. After stimulation of A549 cells with TNF-alpha, IFN-gamma, or LPS, promoter activity was increased by two- to threefold in the presence of adenovirus EIA. In HBE cells, on the other hand, E1A repressed the ICAM-1 promoter after stimulation with IFN-gamma and LPS with little change after TNF-alpha stimulation. In stable E1A transfectants, ICAM-1 promoter activity was 2 to 2.5 times higher than in control transfectants with or without stimulation with TNF-alpha or LPS. These findings suggest that EIA can modulate the activity of the ICAM-1 promoter in lung epithelial cells and this modulation is different in cells of alveolar origin compared to bronchial epithelial cells.

Usefulness of 11C-Methionine Positron Emission Tomography for Monitoring of Treatment Response and Recurrence in a Glioblastoma Patient on Bevacizumab Therapy: A Case Report

Recently developed molecular targeted therapies such as bevacizumab (BEV; Avastin) therapy have therapeutic efficacy for glioblastoma. However, it is difficult to distinguish between a tumor response and nonenhancing tumor progression with conventional magnetic resonance imaging (MRI) after BEV administration. Here we present a recurrent glioblastoma case in which ¹¹C-methionine positron emission tomography (MET-PET) provided useful information for detecting tumor recurrence after complete remission, as assessed by the Response Assessment in Neuro-Oncology criteria. A 47-year-old male with a left frontal lobe glioblastoma experienced recurrence 6 months postoperatively. We administered BEV concomitantly with temozolomide, subsequent to gamma knife surgery. Two months after starting BEV, complete remission was obtained. MET uptake on PET gradually decreased and had nearly disappeared 4 months after initiating BEV. No enhanced area was seen on MRI for 17 months after BEV initiation. Nevertheless, MET-PET revealed recurrence, visualized as nonenhancing tumor progression. MET-PET provides useful information for detecting glioblastoma recurrence, which lacks contrast enhancement on MRI after BEV therapy.

Unique Angiographic Appearances of Moyamoya Disease Detected with 3-Dimensional Rotational Digital Subtraction Angiography Imaging Showing the Hemodynamic Status

BACKGROUND

The aim of this study was to identify the unique morphological arterial features in patients with moyamoya disease on 3-dimensional rotational digital subtraction angiography.

MATERIALS AND METHODS

One hundred seven hemispheres of 58 consecutive patients with moyamoya disease that were analyzed with fused 3-dimensional images of internal carotid angiograms and vertebral angiograms that were marked with different colors were reviewed. Angiographic findings in the posterior watershed area were classified, and the utility of the classification was analyzed by comparing it with clinical presentations and quantitative hemodynamic parameters obtained with positron emission tomography.

RESULTS

Two unique angiographic appearances were identified. A vacant vessel appearance (no arterial inflow despite absence of cortical infarction) was observed mostly in transient ischemic attack hemispheres. In hemispheres with a vacant vessel appearance, cerebral blood flow was decreased, cerebral blood volume was increased, and mean transit time was prolonged significantly (P = .00017, P = .0061, and P = .00026, respectively). A cocktail vessel appearance (mixture of carotid and vertebral arterial flow) was most commonly observed in asymptomatic cases, as well as in ischemic hemispheres. Cerebral blood volume increased and mean transit time was prolonged significantly (P = .036 and P = .014, respectively) in hemispheres with a cocktail vessel appearance. The trend of progression in hemodynamic severity in the order of normal appearance, cocktail vessel appearance, and vacant vessel appearance in the watershed area was statistically significant.

CONCLUSION

Fused 3-dimensional digital subtraction angiography demonstrated unique angiographic features in the watershed area, and this represented the degree of cerebral hemodynamic impairment in moyamoya disease.

D-Meson Azimuthal Anisotropy in Midcentral Pb-Pb Collisions at sqrt[s]_{NN}=5.02 TeV

The azimuthal anisotropy coefficient v_{2} of prompt D^{0}, D^{+}, D^{*+}, and D_{s}^{+} mesons was measured in midcentral (30%-50% centrality class) Pb-Pb collisions at a center-of-mass energy per nucleon pair sqrt[s_{NN}]=5.02  TeV, with the ALICE detector at the LHC. The D mesons were reconstructed via their hadronic decays at midrapidity, |y|<0.8, in the transverse momentum interval 1<p_{T}<24  GeV/c. The measured D-meson v_{2} has similar values as that of charged pions. The D_{s}^{+} v_{2}, measured for the first time, is found to be compatible with that of nonstrange D mesons. The measurements are compared with theoretical calculations of charm-quark transport in a hydrodynamically expanding medium and have the potential to constrain medium parameters.

J/ψ Elliptic Flow in Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

We report a precise measurement of the J/ψ elliptic flow in Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV with the ALICE detector at the LHC. The J/ψ mesons are reconstructed at midrapidity (|y|<0.9) in the dielectron decay channel and at forward rapidity (2.5<y<4.0) in the dimuon channel, both down to zero transverse momentum. At forward rapidity, the elliptic flow v_{2} of the J/ψ is studied as a function of the transverse momentum and centrality. A positive v_{2} is observed in the transverse momentum range 2<p_{T}<8  GeV/c in the three centrality classes studied and confirms with higher statistics our earlier results at sqrt[s_{NN}]=2.76  TeV in semicentral collisions. At midrapidity, the J/ψ  v_{2} is investigated as a function of the transverse momentum in semicentral collisions and found to be in agreement with the measurements at forward rapidity. These results are compared to transport model calculations. The comparison supports the idea that at low p_{T} the elliptic flow of the J/ψ originates from the thermalization of charm quarks in the deconfined medium but suggests that additional mechanisms might be missing in the models.