Anterior mediastinal solid tumours in adults: characterisation using dynamic contrast-enhanced MRI, diffusion-weighted MRI, and FDG-PET/CT

AIM

To find significant parameters to characterise anterior mediastinal solid tumours in adults using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), diffusion-weighted MRI (DWI), and combined 2-[(18)F]-fluoro-2-deoxy-d-glucose positron-emission tomography/computed tomography (FDG-PET/CT).

MATERIALS AND METHODS

Forty-eight histologically confirmed anterior mediastinal solid tumours in 48 patients (24 men, 24 women; age range 21-83 years, mean 50.7 years) were examined. The parameters analysed were maximal diameter, presence of capsule/septa on T2-weighted images, time-signal intensity curves (TICs), apparent diffusion coefficient (ADC), and maximum standardised uptake value (SUVmax). Also examined was whether any differences between histological types could be seen in these parameters. In a validation study, 42 anterior mediastinal solid tumours in 42 patients were examined consecutively.

RESULTS

The washout pattern on TIC was seen only in thymic epithelial tumours (20/32). SUVmax of lymphoma (mean, 17.9), malignant germ cell tumours (14.2), and thymic carcinomas (15.6) were significantly higher than that of thymomas (6.1). The mean maximal diameter of thymic epithelial tumours was significantly smaller than that of lymphomas (p<0.01) and malignant germ cell tumours (p<0.05). The validation study also yielded high accuracy (38/42, 91%) in differentiation among the anterior mediastinal solid tumours.

CONCLUSION

The SUVmax, TIC pattern on DCE-MRI, and maximal diameter might be useful to differentiate anterior mediastinal solid tumours in adults.

Well-ordered monolayers of alkali-doped coronene and picene: molecular arrangements and electronic structures

Adsorptions of alkali metals (such as K and Li) on monolayers of coronene and picene realize the formation of ordered phases, which serve as well-defined model systems for metal-intercalated aromatic superconductors. Upon alkali-doping of the monolayers of coronene and picene, scanning tunneling microscopy and X-ray absorption spectroscopy revealed the rearrangement of the entire molecular layer. The K-induced reconstruction of both monolayers resulted in the formation of a structure with a herringbone-like arrangement of molecules, suggesting the intercalation of alkali metals between molecular planes. Upon reconstruction, a shift in both the vacuum level and core levels of coronene was observed as a result of a charge transfer from alkali metals to coronene. In addition, a new density of states near the Fermi level was formed in both the doped coronene and the doped picene monolayers. This characteristic electronic feature of the ordered monolayer has been also reported in the multilayer picene films, ensuring that the present monolayer can model the properties of the metal-intercalated aromatic hydrocarbons. It is suggested that the electronic structure near the Fermi level is sensitive to the molecular arrangement, and that both the strict control and determinations of the molecular structure in the doped phase should be important for the determination of the electronic structure of these materials.

The voltage-gated proton channel Hv1/VSOP inhibits neutrophil granule release

Neutrophil granule exocytosis is crucial for host defense and inflammation. Neutrophils contain 4 types of granules, the exocytotic release of which is differentially regulated. This exocytosis is known to be driven by diverse mediators, including calcium and nucleotides, but the precise molecular mechanism remains largely unknown. We show in the present study that voltage-gated proton (Hv) channels are necessary for the proper release of azurophilic granules in neutrophils. On activation of NADPH oxidase by PMA and IgG, neutrophils derived from Hvcn1 gene knockout mouse exhibited greater secretion of MPO and elastase than WT cells. In contrast, release of LTF enriched in specific granules was not enhanced in these cells. The excess release of azurophilic granules in Hv1/VSOP-deficient neutrophils was suppressed by inhibiting NADPH oxidase activity and, in part, by valinomycin, a potassium ionophore. In addition, Hv1/VSOP-deficient mice exhibited more severe lung inflammation after intranasal Candida albicans infection than WT mice. These findings suggest that the Hv channel acts to specifically dampen the release of azurophilic granules through, in part, the suppression of increased positive charges at the plasma membrane accompanied by the activation of NADPH oxidase in neutrophils.

High speed prototype quantum key distribution system and long term field trial

Securing information in communication networks is an important challenge in today's world. Quantum Key Distribution (QKD) can provide unique capabilities towards achieving this security, allowing intrusions to be detected and information leakage avoided. We report here a record high bit rate prototype QKD system providing a total of 878 Gbit of secure key data over a 34 day period corresponding to a sustained key rate of around 300 kbit/s. The system was deployed over a standard 45 km link of an installed metropolitan telecommunication fibre network in central Tokyo. The prototype QKD system is compact, robust and automatically stabilised, enabling key distribution during diverse weather conditions. The security analysis includes an efficient protocol, finite key size effects and decoy states, with a quantified key failure probability of ε = 10⁻¹⁰.

Carotid plaque characterization using 3D T1-weighted MR imaging with histopathologic validation: a comparison with 2D technique

BACKGROUND AND PURPOSE

3D FSE T1WI has recently been used for carotid plaque imaging, given the potential advantages in contrast and spatial resolutions. However, its diagnostic performance remains unclear. Hence, we compared the ability of this technique to readily assess plaque characteristics with that of conventional images and validated the results with histologic classification.

MATERIALS AND METHODS

We prospectively examined 34 patients with carotid stenosis who underwent carotid endarterectomy by using 1.5T scanners and obtained 3D-FSE T1WI and 2D spin-echo T1WI scans. After generating reformatted images obtained from the 3D-FSE T1-weighted images, we calculated the contrast ratios for the plaques and the adjacent muscles and compared these findings with the pathologic classifications.

RESULTS

Carotid plaques were histologically classified as types VII, VIII, IV-V, or VI. With 3D-FSE T1WI, the range of contrast ratios for each classification was the following: 0.94-0.97 (median, 0.95), 0.95-1.29 (median, 1.10), 1.33-1.54 (median, 1.42), and 1.53-2.12 (median, 1.80), respectively. With 2D imaging, the range of contrast ratios for each classification was the following: 0.79-1.02 (median, 0.90), 0.88-1.19 (median, 1.01), 1.17-1.46 (median, 1.23), and 1.55-2.51 (median, 2.07), respectively. Results were significantly different among the 4 groups (P < .001). Sensitivity and specificity for discriminating vulnerable plaques (IV-VI) from stable plaques (VII, VIII) were both 100% for the 3D technique and 100% and 91%, respectively, for the 2D technique.

CONCLUSIONS

3D-FSE T1WI accurately characterizes intraplaque components of the carotid artery, with excellent sensitivity and specificity compared with those of 2D-T1WI.

Thermal boundary resistance at Au/Ge/Ge and Au/Si/Ge interfaces

Amorphous Ge (a-Ge), crystalline Ge (c-Ge), and amorphous Si (a-Si) thin films were deposited on a Ge substrate at different temperatures by magnetron sputtering.

Anomalous transport phenomena in Weyl metal beyond the Drude model for Landau's Fermi liquids

Landau's Fermi-liquid theory is the standard model for metals, characterized by the existence of electron quasiparticles near a Fermi surface as long as Landau's interaction parameters lie below critical values for instabilities. Recently this fundamental paradigm has been challenged by the physics of strong spin-orbit coupling, although the concept of electron quasiparticles remains valid near the Fermi surface, where Landau's Fermi-liquid theory fails to describe the electromagnetic properties of this novel metallic state, referred to as Weyl metal. A novel ingredient is that such a Fermi surface encloses a Weyl point with definite chirality, referred to as a chiral Fermi surface, which can arise from breaking of either time reversal or inversion symmetry in systems with strong spin-orbit coupling, responsible for both the Berry curvature and the chiral anomaly. As a result, electromagnetic properties of the Weyl metallic state are described not by conventional Maxwell equations but by axion electrodynamics, where Maxwell equations are modified with a topological-in-origin spatially modulated [Formula: see text] term. This novel metallic state was realized recently in Bi[Formula: see text]Sb _x around [Formula: see text] under magnetic fields, where the Dirac spectrum appears around the critical point between the normal semiconducting ([Formula: see text]) and topological semiconducting phases ([Formula: see text]) and the time reversal symmetry breaking perturbation causes the Dirac point to split into a pair of Weyl points along the direction of the applied magnetic field for a very strong spin-orbit coupled system. In this review article, we discuss how the topological structure of both the Berry curvature and the chiral anomaly (axion electrodynamics) gives rise to anomalous transport phenomena in [Formula: see text]Sb _x around [Formula: see text] under magnetic fields, thus modifying the Drude model of Landau's Fermi liquids.

Factors associated with asthma control in children: findings from a national Web-based survey

BACKGROUND

Although achieving and maintaining control of asthma is considered to be the goal of asthma treatment, determinants of asthma control are not fully understood. Our aim was to assess factors associated with asthma control among paediatric patients in the general population.

METHODS

In June 2012, a Web-based survey was conducted to identify Japanese children aged 6 to 11 yr who currently have asthma and evaluate control of their disease using the Childhood Asthma Control Test (C-ACT). Associations were evaluated among uncontrolled asthma (C-ACT score <20) between environmental factors, demographics and comorbid allergic diseases.

RESULTS

Among the 3066 children with current asthma, 447 (14.6%) had uncontrolled asthma. Multivariable analysis identified factors such as low birthweight (adjusted OR 1.65, 95% CI 1.25-2.18), obesity (adjusted OR 1.44, 95% CI 1.05-1.99) and pet ownership before birth (adjusted OR 1.68, 95% CI 1.24-2.29) to be associated with uncontrolled disease. Comorbid allergic diseases, especially rhinitis were a significant risk of uncontrolled asthma (adjusted OR for severe rhinitis: 3.88, 95% CI 2.50-6.00). The severity of rhinitis symptoms was inversely correlated with the C-ACT score (p < 0.001).

CONCLUSIONS

A population-based Web survey showed an association between several factors and the control of paediatric asthma. The assessment of these factors may help identify the children at risk with uncontrolled asthma.

eNOS plays an important role in the regulation of colonic inflammation: a novel therapeutic target and a predictive marker for the prognosis of ulcerative colitis

BACKGROUND

We reported that deficiency of the eNOS protein exacerbates colitis induced by dextran sodium sulfate (DSS-induced colitis). However, the role of eNOS in colitis remains controversial. Therefore, we studied how over-expression of eNOS affected this inflammatory condition, using vascular endothelial cells and mice as in vitro and in vivo models, respectively. Furthermore, we investigated the influence of a polymorphism in the eNOS gene on the clinical features of ulcerative colitis (UC).

METHODS

We examined the effect of eNOS overexpression on the expression of adhesion molecules in the endothelium and assessed the degree of DSS-induced colitis in eNOS transgenic (eNOS-Tg) mice. We also investigated the relationship between a polymorphism in the eNOS gene and clinical features of patients with UC.

RESULTS

The expression of adhesion molecules, under inflammatory conditions, was attenuated in eNOS gene-transfected vascular endothelial cells, as measured by western blot analysis. Symptoms of DSS-induced colitis were likewise attenuated in eNOS-Tg mice, which exhibited lower weight loss, mortality, histological damage (by inflammation score and crypt damage score), and colonic myeloperoxidase activity, tumor necrosis factor-α expression, and MAdCAM-1 expression than in wild-type mice. Furthermore, there was a significant relationship between intractable cases of UC and a polymorphism in the eNOS gene promoter (c.-786 T > C) that decreases eNOS expression.

CONCLUSION

The eNOS gene plays an important role in the regulation of colonic inflammation. The level of eNOS expression may be a predictive marker for prognosis of UC, and eNOS expression may be a novel therapeutic target.

Hand metastasis from a sacral chordoma

Chordomas are rare, low grade, malignant tumours derived from the ectopic remnants of the notochord that line the axial skeleton. They are characterised by their slow growth, long disease course and propensity for local relapse. Furthermore, up to 40% of non-cranial chordomas metastasise. We describe the first reported case of a hand metastasis arising from a conventional sacral chordoma after carbon ion radiotherapy. The common occurrence of distant metastasis with chordomas makes it important to perform a systemic examination, in part because their resection might improve patient prognosis.

Development and Validation of LC-MS/MS Assay for the Quantification of Progesterone in Rat Plasma and its Application to Pharmacokinetic Studies

A sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the determination of progesterone levels in rat plasma. Progesterone-d9 was used as an internal standard (IS). Samples were prepared using salting-out assisted liquid/liquid extraction (SALLE), and the extracts were injected directly onto the LC-MS/MS system. The chromatographic separation was achieved on a CAPCELL PAK C18 MGIII column (100 mm × 2.0 mm, i.d. 5 µm) using methanol and aqueous 0.1% formic acid solution gradient as the mobile phase with a constant flow rate of 0.45 mL/min. Electrospray ionization in the positive-ion mode was employed. Multiple reaction monitoring of the precursor to product ion pairs, from m/z 315.20 to m/z 109.10 for progesterone and from m/z 324.26 to m/z 113.07 for the IS, was used for quantification. Good linearity was observed over the concentration range of 0.05-20.00 ng/mL with a weighted (1/x(2)) linear regression. The intra- and inter-day precision (% relative standard deviation [RSD]) across 3 validation days over the entire concentration range was lower than 6.7%. Accuracy (% nominal) determined at 5 quality control concentrations was between 94.0 and 103.7%. The validation method was applied in a pharmacokinetic study evaluating progesterone levels after intramuscular or vaginal administration to ovariectomized (OVX) rats. The area under the plasma concentration-time curve (AUC) calculated after intramuscular administration was more than 4 times higher than the AUC measured following vaginal administration of a comparable dose.

Time-dependent variation in the responses to the web-based ISAAC questionnaire

BACKGROUND

Epidemiologic studies have shown seasonal variations in responses to the written questionnaire for rhinitis symptoms.

OBJECTIVE

To evaluate whether the timing of data collection affected responses to the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire in a Web-based study.

METHODS

The Web-based ISAAC questionnaires were completed by parents with children 6 to 12 years old using an online research system. The authors conducted surveys of asthma symptoms every month for 1 year and surveys of rhinitis and eczema symptoms every season throughout 1 entire year.

RESULTS

There was a significant fluctuation in the positive responses to questions about wheezing in the past 12 months (P < .001) but not in the positive responses to questions about exercise-induced wheezing in the past 12 months and asthma ever (P = .75 and P = .15, respectively). The positive responses to questions about rhinitis and allergic rhinoconjunctivitis in the past 12 months and pollinosis ever exhibited significant seasonal variations (P = .002, P < .001, and P < .001, respectively). In contrast, there were no significant variations in positive responses regarding eczema in the past 12 months and eczema ever (P = .33 and P = .55, respectively).

CONCLUSION

There were time-dependent fluctuations in responses to the Web-based questionnaire regarding allergic symptoms. Timing of data collection should be taken into account when evaluating prevalence of asthma and rhinitis in children.

Tumor necrosis factor-alpha induces expression of C/EBP-beta in primary afferent neurons following nerve injury

CCAAT/enhancer binding protein-beta (C/EBP-beta) is a transcription factor that belongs to the C/EBP family. To understand the role of C/EBP-beta in the peripheral nervous system, we investigated the expression of C/EBP-beta in the dorsal root ganglion. C/EBP-beta was weakly detected in nuclei of naive dorsal root ganglion (DRG) neurons. Spinal nerve ligation increased the expression of C/EBP-beta in L4 and L5 DRG neurons. Treatment with anti-TNF-alpha prevented SNL-induced pain hypersensitivity and C/EBP-beta expression in the DRG. Injection of TNF-alpha into the sciatic nerve produced transient pain hypersensitivity and induction of C/EBP-beta expression in the DRG. These results demonstrate that C/EBP-beta is activated in the DRG neurons by a TNF-alpha-dependent manner and might be involved in the activation of primary afferent neurons after nerve injury.

Detectability of simulated interstitial pneumonia on chest radiographs: comparison between irradiation side sampling indirect flat-panel detector and computed radiography

OBJECTIVE

To compare the detectability of simulated interstitial pneumonia on chest radiographs between an irradiation side sampling indirect flat-panel detector (ISS-FPD) and computed radiography (CR).

METHODS

Simulated interstitial pneumonia findings (ground-glass opacity, reticular opacity and honeycomb lung) were superimposed on an anthropomorphic chest phantom. Chest radiographs were acquired under three exposure levels (4.0, 3.2 and 2.0 mAs) with an ISS-FPD and with CR. 5 thoracic radiologists evaluated 72 images for the presence or absence of a lesion over each of 6 areas. A total of 1296 observations were analysed in a receiver-operating characteristic analysis. A jackknife method was used for the statistical analysis.

RESULTS

The areas under the curves (AUCs) for the detection of simulated honeycomb lung obtained with the ISS-FPD were significantly larger than those obtained with CR at all exposure conditions. For the detection of simulated ground-glass opacity and reticular opacity, there were no significant differences between the two systems. In addition, the AUCs for the detectability of simulated honeycomb lung obtained with the ISS-FPD at all exposure levels were significantly larger than those obtained with CR at 4 mAs.

CONCLUSION

The ISS-FPD was superior to CR for the detection of simulated honeycomb lung. Provided that the chosen model is representative of interstitial pneumonia, the use of an ISS-FPD might reduce a patient's exposure dose during the detection of interstitial pneumonia.

ADVANCES IN KNOWLEDGE

The ISS-FPD has shown its advantage compared with CR in the detection of honeycombing, one sign of interstitial pneumonia.

Long-time correlation in non-Markovian dephasing of an exciton-phonon system in InAs quantum dots

We have observed a time-correlated frequency fluctuation in non-Markovian dephasing of excitons in InAs quantum dots using a six-wave mixing technique. In this measurement, the arrival times of the excitation pulses were controlled to eliminate the influence of Markovian dephasing and to measure the pure non-Markovian behavior. The experimental result shows that the time correlation of the frequency fluctuation due to exciton-phonon interactions was maintained in the quantum dots for over 10 ps. This long-time correlation is caused by the modification of the phonon coupling distribution.

[A case of renal spindle cell carcinoma]

An asymptomatic 67-year-old woman was found to have renal tumors by chance on a screening abdominal ultrasound examination. Although surgical resection was planned for both a diagnostic purposes and treatment, she suddenly developed hemorrhage from the cerebral metastasis in the left thalamus, and the surgical procedure was postponed. Irradiation with a gamma knife was performed to treat the cerebral metastasis; however, the patient's general condition quickly worsened, and she died six months after diagnosis. An autopsy showed typical spindle cells in the primary lesion with multiple metastases. Renal spindle cell carcinoma is a relatively rare type of the renal carcinoma that is both very aggressive and exhibits a poor prognosis, with few established treatments. Hence, obtaining an early diagnosis on abdominal ultrasound is important in such cases.

Dirac versus Weyl fermions in topological insulators: Adler-Bell-Jackiw anomaly in transport phenomena

Dirac metals (gapless semiconductors) are believed to turn into Weyl metals when perturbations, which break either time reversal symmetry or inversion symmetry, are employed. However, no experimental evidence has been reported for the existence of Weyl fermions in three dimensions. Applying magnetic fields near the topological phase transition from a topological insulator to a band insulator in Bi1-xSbx we observe not only the weak antilocalization phenomenon in magnetoconductivity near zero magnetic fields (B<0.4  T), but also its upturn above 0.4 T only for E//B. This "incompatible" coexistence between weak antilocalization and "negative" magnetoresistivity is attributed to the Adler-Bell-Jackiw anomaly ("topological" E·B term) in the presence of weak antilocalization corrections.

Predicting carotid plaque characteristics using quantitative color-coded T1-weighted MR plaque imaging: correlation with carotid endarterectomy specimens

BACKGROUND AND PURPOSE

MR plaque imaging is used to evaluate the risk of embolic complications during carotid endarterectomy and carotid artery stent placement. However, its performance for characterizing intraplaque components has varied across studies and is generally suboptimal. Hence, we correlated MR imaging results with histologic findings to determine whether a combination of high-contrast T1-weighted imaging and quantitative image analysis could readily determine plaque characteristics.

MATERIALS AND METHODS

We prospectively examined 40 consecutive patients before carotid endarterectomy by using a 1.5T scanner and axial T1-weighted spin-echo images under optimized scanning conditions. The percentage areas of intraplaque fibrous tissue, lipid/necrosis, and hemorrhage were calculated automatically by using the software with previously reported cutoff values and were compared with those of the specimens. The thickness of the fibrous cap was also measured manually.

RESULTS

The percentage areas of fibrous, lipid/necrotic, and hemorrhagic components were 5.7%-98.7%, 1.3%-65.7%, and 0%-82.0%, respectively, as determined by the MR images, whereas the corresponding values were 4.8%-92.3%, 7.0%-93.8%, and 0%-70.4%, respectively, as determined by histologic examination. Significant positive correlation and agreement were observed between MR images and histologic specimens (r = 0.92, 0.79, and 0.92; intraclass correlation coefficients = 0.91, 0.67, and 0.89; respectively). Thickness of the fibrous caps on MR images (0.21-0.87 mm) and in the specimens (0.14-0.83 mm) also showed positive correlation and agreement (r = 0.61, intraclass correlation coefficient = 0.59).

CONCLUSIONS

Quantitative analysis of high-contrast T1-weighted images can accurately evaluate the composition of carotid plaques in carotid endarterectomy candidates.

Regulation of eotaxin-3/CC chemokine ligand 26 expression by T helper type 2 cytokines in human colonic myofibroblasts

Eotaxins induce the trafficking of eosinophils to the sites of inflammation via CC chemokine receptor 3 (CCR3). In this study, we investigated eotaxin-3/CC chemokine ligand 26 (CCL26) expression in the inflamed mucosa of patients with inflammatory bowel disease (IBD), and characterized the molecular mechanisms responsible for eotaxin-3 expression in human colonic myofibroblasts. Eotaxin-3 mRNA and protein expression was evaluated by real time-polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. Eotaxin-3 mRNA expression was elevated significantly in the active lesions of ulcerative colitis (UC) patients. Significant elevations were also observed in the active lesions of Crohn's disease (CD) patients, but this was significantly lower than that detected in the active UC lesions. There were no significant increases in the inactive lesions of UC or CD patients. Colonic myofibroblasts were identified as a major source of eotaxin-3 in the colonic mucosa, and interleukin (IL)-4 and IL-13 enhanced eotaxin-3 mRNA and protein expression significantly in these cells. There was a significant positive correlation between mucosal eotaxin-3 and IL-4 mRNA expression in the active lesions of IBD patients. The IL-4- and IL-13-induced eotaxin-3 mRNA expression was regulated by the signal transducer and activator of transcription-6 (STAT-6) and suppressor of cytokine signalling (SOCS)1-mediated pathways. Interferon (IFN)-γ acts as a negative regulator on the IL-4- and IL-13-induced eotaxin-3 expression via STAT-1 activation. Eotaxin-3 expression was elevated specifically in the active lesions of IBD, in particular UC. Eotaxin-3 derived from colonic myofibroblasts may play an important role in the pathophysiology of UC.