Development of age-specific Japanese head phantoms for dose evaluation in paediatric head CT examinations

In this study, the authors developed age-specific physical head phantoms simulating the physique of Japanese children for dose evaluation in paediatric head computed tomography (CT) examinations. Anatomical structures at 99 places in 0-, 0.5-, 1- and 3-y-old Japanese patients were measured using DICOM viewer software from CT images, and the head phantom of each age was designed. For trial manufacture, a 3-y-old head phantom consisting of acrylic resin and gypsum was produced by machine processing. Radiation doses for the head phantom were measured with radiophotoluminescence glass dosemeters and Si-pin photodiode dosemeters. To investigate whether the phantom shape was suitable for dose evaluation, organ doses in the same scan protocol were compared between the 3-y-old head and commercially available anthropomorphic phantoms having approximately the same head size. The doses of organs in both phantoms were equivalent. The authors' designed paediatric head phantom will be useful for dose evaluation in paediatric head CT examinations.

Search for bosonic superweakly interacting massive dark matter particles with the XMASS-I detector

Bosonic superweakly interacting massive particles (super-WIMPs) are a candidate for warm dark matter. With the absorption of such a boson by a xenon atom, these dark matter candidates would deposit an energy equivalent to their rest mass in the detector. This is the first direct detection experiment exploring the vector super-WIMPs in the mass range between 40 and 120 keV. With the use of 165.9 day of data, no significant excess above background was observed in the fiducial mass of 41 kg. The present limit for the vector super-WIMPs excludes the possibility that such particles constitute all of dark matter. The absence of a signal also provides the most stringent direct constraint on the coupling constant of pseudoscalar super-WIMPs to electrons. The unprecedented sensitivity was achieved exploiting the low background at a level 10(-4)  kg-1 keVee-1 day-1 in the detector.

Development of a high dynamic range spectroscopic system for observation of neutral hydrogen atom density distribution in Large Helical Device core plasma

We report development of a high dynamic range spectroscopic system comprising a spectrometer with 30% throughput and a camera with a low-noise fast-readout complementary metal-oxide semiconductor sensor. The system achieves a 10(6) dynamic range (∼20 bit resolution) and an instrumental function approximated by a Voigt profile with Gauss and Lorentz widths of 31 and 0.31 pm, respectively, for 656 nm light. The application of the system for line profile observations of the Balmer-α emissions from high temperature plasmas generated in the Large Helical Device is also presented. In the observed line profiles, emissions are detected in far wings more than 1.0 nm away from the line center, equivalent to neutral hydrogen atom kinetic energies above 1 keV. We evaluate atom density distributions in the core plasma by analyzing the line profiles.

Additive combination of actarit and methotrexate in the treatment of refractory rheumatoid arthritis

Abstract The objective of this study was to evaluate the efficacy and safety of an additive combination of a disease-modifying antirheumatic drug (DMARD) actarit and low-dose methotrexate (MTX) in patients with active rheumatoid arthritis (RA) unresponsive to MTX. Thirty-four patients with active RA, who had been unsuccessfully treated with MTX for at least 3 months were enrolled on a 24-week course of actarit (300 mg/day) and MTX (2.5-10 mg/week). Disease activity was evaluated by physical global assessments using conventional measures (Japan Rheumatism Association), and the American College of Rheumatology (ACR) criteria of improvements in RA. Thirty-two patients completed this study. No severe adverse drug reactions were seen. Patients whose RA did not respond to MTX alone responded to the combination therapy, with a significant improvement in the duration of morning stiffness, grip strength, swollen joint counts, patient's articular pain score, modified health assessment questionnaire (M-HAQ) score, score of both patient's and physician's global assessments, and C-reactive proteins (CRP). Sixteen patients (50.0%) and 9 patients (31.0%) showed a significant improvement in overall conventional measures, and ACR response criteria, respectively, and 60.0% of RA patients who received MTX for more than 1 year showed improvement in ACR definition. Patients who responded to the combination treatment within the first 12 weeks showed persistent improvement for the remaining part of the 24 week period. Our results indicate that the additive combination of actarit and MTX is safe, and without serious adverse effects, and has an excellent efficacy in patients with active and refractory RA.

Impact of antihypertensive medication adherence on blood pressure control in hypertension: the COMFORT study

BACKGROUND

It has not been fully elucidated whether antihypertensive medication adherence affects blood pressure (BP) control in hypertension cases.

AIM

To investigate the association of adherence to antihypertensive drug regimens and BP control using data from the Combination Pill of Losartan Potassium and Hydrochlorothiazide for Improvement of Medication Compliance Trial (COMFORT) study.

DESIGN

An observational analysis from a randomized controlled trial.

METHODS

A total of 203 hypertensive subjects were randomly assigned to a daily regimen of a combination pill (losartan 50 mg/hydrochlorothiazide 12.5 mg) or two pills, an angiotensin II receptor blocker and a thiazide diuretic. Medication adherence calculated based on pill counts and BPs was evaluated at 1, 3 and 6 months after randomization.

RESULTS

The subjects were divided into three groups according to their adherence, i.e. relatively low-adherence (<90%; n = 19), moderate-adherence (90-99%; n = 71) and high-adherence (100%; n = 113) groups. Clinical characteristics of the subjects including BP, sex, randomized treatments and past medical history did not differ significantly among the three groups. Achieved follow-up BPs over the 6-month treatment period, which were adjusted for age, sex, baseline BP and randomized treatment, were significantly higher in the low-adherence group (135/78 mmHg) compared with the high-adherence (130/74 mmHg; P = 0.02/0.02) and the moderate-adherence (128/74 mmHg; P = 0.003/0.02) groups.

CONCLUSION

Low adherence to an antihypertensive-drug regimen was associated with poor BP control.

Development of a compact thermal lithium atom beam source for measurements of electron velocity distribution function anisotropy in electron cyclotron resonance plasmas

The anisotropy of the electron velocity distribution function (EVDF) in plasmas can be deduced from the polarization of emissions induced by anisotropic electron-impact excitation. In this paper, we develop a compact thermal lithium atom beam source for spatially resolved measurements of the EVDF anisotropy in electron cyclotron resonance (ECR) plasmas. The beam system is designed such that the ejected beam has a slab shape, and the beam direction is variable. The divergence and flux of the beam are evaluated by experiments and calculations. The developed beam system is installed in an ECR plasma device with a cusp magnetic field, and the LiI 2s-2p emission (670.8 nm) is observed in low-pressure helium plasma. The two-dimensional distributions of the degree and direction of the polarization in the LiI emission are measured by a polarization imaging system. The evaluated polarization distribution suggests the spatial variation of the EVDF anisotropy.

Abstract P4-03-08: A new real-time image fusion technique, a coordinated sonography and MRI using magnetic position tracking system, improves the sonographic identification of enhancing lesions in breast MRI

Breast magnetic resonance imaging (MRI) is a method that can detect clinically and mammographically occult cancer foci. For lesions suspected to be malignant on the basis of breast MRI, targeted sonography can help determine whether the lesion is amenable to tissue biopsy using sonographic guidance. However, the reproducibility of sonography as well as interexaminer reliability in targeted sonography is still a clinical issue. Recently, we have developed real-time virtual sonography (RVS) that can coordinate a sonographic image and a MRI multiplanar reconstruction (MRI-MPR) of the same section in real time. Although RVS has been reported to be useful for breast cancers, only a few studies have investigated the size and positioning error between a real-time sonographic image and a MRI-MPR image. The purpose of this study was to evaluate the accuracy of RVS to sonographically identify enhancing lesions by breast MRI. Between December 2008 and May 2009, RVS was performed in 51 consecutive patients with 63 enhancing lesions. MRI was performed with the patients in the supine position using a 1.5-T imager with a body surface coil to achieve the same position as with sonography. To assess the accuracy of the RVS, the following three issues were analyzed: (i) The sonographic detection rate of enhancing lesions, (ii) the comparison of the tumor size measured by sonography and the MRI-MPR and (iii) the positioning errors as the distance from the actual sonographic position to the expected MRI position in 3-D. Among the 63 enhancing lesions, 42 (67%) lesions were identified by conventional B-mode, whereas the remaining 21 (33%) initial conventional B-mode occult lesions were identified by RVS alone. The sonographic size of the lesions detected by RVS alone was significantly smaller than that of lesions detected by conventional B-mode (p &lt; 0.001). The mean tumor size provided by RVS was 12.3 mm for real-time sonography and 14.1 mm for MRI-MPR (r = 0.848, p &lt; 0.001). The mean positioning errors for the transverse and sagittal planes and the depth from the skin were 7.7, 6.9 and 2.8 mm, respectively. The overall mean 3D positioning error was 12.0 mm. Our results suggest that RVS has good targeting accuracy to directly compare a sonographic image with MRI results without operator dependence.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-03-08.

Unpaired electron species in thin films of calf-thymus DNA molecules induced by nitrogen and oxygen K-shell photoabsorption

The mechanism of DNA modification induced by K-shell photoabsorption of nitrogen and oxygen atoms was investigated by electron paramagnetic resonance and x-ray absorption near edge structure measurements of calf thymus DNA. A g factor of 2.000 for the unpaired electron species, which only arises during irradiation, was measured. The EPR intensities for DNA zwere twofold times larger than those estimated based on the photoabsorption cross section. This suggests that the DNA film itself forms unpaired electron species through the excitation of enhanced electron recapturing, known as the postcollision interaction process.