Development of in situ energetic ion injector for magnetically confined plasmas using hydrogen storage electrode

To develop a compact ion injector made of hydrogen storage material, we investigate a plasma response for a positively biased hydrogen storage electrode in a small standard heliac device. When the bias voltage of the electrode increases, a positive potential between the electrode and the space potential on the magnetic surface emerges. The emission of hydrogen atom line also increases. To clarify the origin of the increase in emission, we designed an imaging system with sufficient temporal resolution.

Effects of roughness and temperature on low-energy hydrogen positive and negative ion reflection from silicon and carbon surfaces

Angle-resolved energy distribution functions of positive and negative hydrogen ions produced from a rough-finished Si surface under 1 keV proton irradiation have been measured. The corresponding distribution from a crystalline surface and a carbon surface are also measured for comparison. Intensities of positive and negative ions from the rough-finished Si are substantially smaller than those from crystalline Si. The angular distributions of these species are broader for rough surface than the crystalline surface. No significant temperature dependence for positive and negative ion intensities is observed for all samples in the temperature range from 300 to 400 K.

Hypothalamic ATF3 is involved in regulating glucose and energy metabolism in mice

AIMS/HYPOTHESIS

The pancreas and hypothalamus are critical for maintaining nutrient and energy homeostasis, and combined disorders in these organs account for the onset of the metabolic syndrome. Activating transcription factor 3 (ATF3) is an adaptive response transcription factor. The physiological role of ATF3 in the pancreas has been controversial, and its role in the hypothalamus remains unknown. To elucidate the roles of ATF3 in these organs, we generated pancreas- and hypothalamus-specific Atf3 knockout (PHT-Atf3-KO) mice in this study.

METHODS

We crossed mice bearing floxed Atf3 alleles with Pdx1-cre mice, in which cre is specifically expressed in the pancreas and hypothalamus, and analysed metabolic variables, pancreatic morphology, food intake, energy expenditure and sympathetic activity in adipose tissue. We also used a hypothalamic cell line to investigate the molecular mechanism by which ATF3 regulates transcription of the gene encoding agouti-related protein (Agrp).

RESULTS

Although PHT-Atf3-KO mice displayed better glucose tolerance, neither plasma glucagon nor insulin level was altered in these mice. However, these mice exhibited higher insulin sensitivity, which was accompanied by a leaner phenotype due to decreased food intake and increased energy expenditure. We also observed decreased hypothalamic Agrp expression in PHT-Atf3-KO mice. Importantly, an increase in ATF3 levels is induced by fasting or low glucose in the hypothalamus. We also showed that ATF3 interacts with forkhead box-containing protein, O subfamily 1 (FoxO1) on the Agrp promoter and activates Agrp transcription.

CONCLUSIONS/INTERPRETATION

Our results suggest that ATF3 plays an important role in the control of glucose and energy metabolism by regulating Agrp.

Delaying embryo development by storing at 4°C for synchronization to recipients in microinjection technique in rabbits

Short-term storage of embryos at low temperature induces developmental arrest of the embryo and would appear to be a valuable aid in embryo-transfer techniques to avoid wasting embryos. Embryo storage at 4°C was examined to allow synchronization with embryo-transfer recipients using the microinjection technique. Superovulation was induced in female Japanese White donor rabbits four days before mating with males. At the same time, control recipients were injected with human chorionic gonadotropin (hCG) to allow synchronization (R1); the hCG injections were delayed by 24 h in the experimental group (R2). DNA constructs for expressing human C-reactive protein or apolipoprotein AII were microinjected into the male pronuclei of the ova. The microinjected embryos were immediately transferred to recipients (R1) or stored at 4°C in phosphate-buffered saline containing 10% fetal bovine serum. After 17-20 h, the stored embryos were incubated at 37°C for one hour, and the morphologically normal embryos were transferred to recipients (R2). In the R1 rabbits, 855 embryos were transferred to 29 recipients, and 72.4% of the recipients became pregnant. Seven of the 84 offspring were transgenic. In the R2 rabbits, 478 embryos were transferred to 16 recipients, and 62.5% of the recipients became pregnant. Two of the 39 offspring were transgenic. There were no differences in pregnancy rate, litter size and transgenic integration rate between R1 and R2. These results suggest that the short-term 4°C storage of microinjected embryos can be a valuable method for synchronization with recipients, and reducing wastage of embryos and the sacrifice of rabbits.

[Resection of malignant fibrous histiocytoma through a combined thoracic and abdominal wall approach]

We report a case of resection of malignant fibrous histiocytoma (MFH) via combined thoracic and abdominal wall incision reconstructed using GORE DUALMESH. A 60-year-old woman underwent resection of a left lower chest wall tumor. Since the tumor infiltrated into the diaphragm, a part of the left diaphragm and left upper abdominal wall were resected together. The left chest was closed by suturing the diaphragm to the ribs. The resected area of the thoracic and abdominal wall was 12×12 cm and was reconstructed with GORE DUALMESH. She received adjuvant radiotherapy as the tumor cells were detected in the surgical margin of the diaphragm. The patient has remained well without signs of recurrence for 10 months after the operation.

Development of a He- and He0 beam source for alpha particle measurement in a burning plasma

Proof of principle experiments of neutral helium beam production for alpha particle diagnostics was carried out on a test stand. Negative helium ions were produced in the Li charge exchange cell, in which stable and long time operation was possible. He(-) beam was accelerated to 157 keV. Finally, He(0) beam was successfully produced after the flight in the drift-tube through the auto-electron-detachment process from He(-) to He(0). A neutral beam detector using a pyroelectric device was also developed to measure He(0) beam intensity. The metastable component in the neutral helium beam was found to be less than 2%.

Extraction of a strongly focusing He+ beam from three-stage concave electrodes for alpha particle measurement system in ITER

A strongly focusing He(+) ion beam source equipped with concave multi-aperture electrodes was developed for production of He(-) through a charge exchange cell. The beam was extracted at a voltage less than 20 kV from 301 apertures distributed in an area of 100 mm φ, and focused at 750 mm distance. The beam current and the beam size of 2 A and 20 mm in diameter, respectively, were achieved with an arc power less than 10 kW. The optimum perveance was obtained at 0.02 A∕kV(1.5) at the beam energy less than 20 keV which is suitable for the conversion to He(-) in an alkali vapor cell.

An alpha particle measurement system using an energetic neutral helium beam in ITER (invited)

An energetic helium neutral beam is involved in the beam neutralization measurement system of alpha particles confined in a DT fusion plasma. A full size strong-focusing He(+) ion source (2 A, the beam radius of 11.3 mm, the beam energy less than 20 keV). Present strong-focusing He(+) ion source shows an emittance diagram separated for each beamlet of multiple apertures without phase space mixing, despite the space charge of a beamlet is asymmetric and the beam flow is non-laminar. The emittance of beamlets in the peripheral region was larger than that of center. The heat load to the plasma electrode was studied to estimate the duty factor for the ITER application.

Key role of ATF3 in p53-dependent DR5 induction upon DNA damage of human colon cancer cells

Stress response gene ATF3 is one of the p53 target genes and has a tumor suppressor role in cancer. However, the biological role of p53-ATF3 pathway is not well understood. Death receptor 5 (DR5) is a death domain-containing transmembrane receptor that triggers cell death upon binding to its ligand TRAIL (tumor necrosis factor-related apoptosis-inducing ligand), and a combination of TRAIL and agents that increase the expression of DR5 is expected as a novel anticancer therapy. In this report, we demonstrate that ATF3 is required for efficient DR5 induction upon DNA damage by camptothecin (CPT) in colorectal cancer cells. In the absence of ATF3, induction of DR5 messenger RNA and protein is remarkably abrogated, and this is associated with reduced cell death by TRAIL and CPT. By contrast, exogenous expression of ATF3 causes more rapid and elevated expression of DR5, resulting in enhanced sensitivity to apoptotic cell death by TRAIL/CPT. Reporter assay and DNA affinity precipitation assay demonstrate that at least three ATF/CRE motifs at the proximal promoter of the human DR5 gene are involved in the activation of DNA damage-induced DR5 gene transcription. Furthermore, ATF3 is shown to interact with p53 to form a complex on the DR5 gene by Re-chromatin immunoprecipitation assay. Taken together, our results provide a novel insight into the role of ATF3 as an essential co-transcription factor for p53 upon DNA damage, and this may represent a useful biomarker for TRAIL-based anticancer therapy.

Pancreatic β-cells activate a JunB/ATF3-dependent survival pathway during inflammation

Destruction of insulin-producing pancreatic β-cells by local autoimmune inflammation is a hallmark of type 1 diabetes. Histochemical analysis of pancreases from non-obese diabetic mice indicated activation of the transcription factor JunB/AP-1 (activator protein-1) after autoimmune infiltration of the islets. In vitro studies demonstrated that the cytokines tumor necrosis factor (TNF)-α and interferon (IFN)-γ induce JunB expression as a protective mechanism against apoptosis in both human and rodent β-cells. The gene network affected was studied by microarray analysis showing that JunB regulates nearly 20% of the cytokine-modified β-cell genes, including the transcription factor ATF3. Direct transcriptional induction of ATF3 by JunB is a key event for β-cell survival after TNF-α+IFN-γ treatment. Moreover, pharmacological upregulation of JunB/ATF3 via increased cAMP protected rodent primary β-cells and human islet cells against pro-inflammatory mediators. These results were confirmed in genetically modified islets derived from Ubi-JunB transgenic mice. Our findings identify ATF3 as a novel downstream target of JunB in the survival mechanism of β-cells under inflammatory stress.

Human C-reactive protein enhances thrombus formation after neointimal balloon injury in transgenic rabbits

BACKGROUND

High plasma levels of C-reactive protein (CRP) constitute a powerful predictive marker of cardiovascular events. Several lines of evidence suggest that CRP has prothrombogenic effects. However, whether CRP directly participates in the pathogenesis of thrombosis in vivo has not been fully clarified.

OBJECTIVE

To test whether human CRP (hCRP) affects arterial thrombus formation after balloon injury of smooth muscle cell (SMC)-rich or macrophage-rich neointima.

METHODS

We compared the susceptibility of transgenic (Tg) rabbits expressing hCRP (46.21 ± 13.85 mg L(-1), n = 22) and non-Tg rabbits to arterial thrombus formation after balloon injury of SMC-rich or macrophage-rich neointima.

RESULTS

Thrombus size on SMC-rich or macrophage-rich neointima was significantly increased, and was accompanied by an increase in fibrin content in hCRP-Tg rabbits, as compared with non-Tg rabbits. Thrombus size did not significantly differ between SMC-rich and macrophage-rich neointima in hCRP-Tg rabbits. Tissue factor (TF) mRNA expression and activity in these neointimal lesions were significantly increased in hCRP-Tg rabbits as compared with non-Tg rabbits. The degree of CRP deposition correlated with the elevated TF expression and thrombus size on injured neointima. In addition, hCRP isolated from hCRP-Tg rabbit plasma induced TF mRNA expression and activity in rabbit cultured vascular SMCs.

CONCLUSIONS

These results suggest that elevated plasma hCRP levels promote thrombus formation on injured SMC-rich neointima by enhancing TF expression, but have no additive effects in macrophage-rich neointima.

Fast neutron-gamma discrimination on neutron emission profile measurement on JT-60U

A digital signal processing (DSP) system is applied to stilbene scintillation detectors of the multichannel neutron emission profile monitor in JT-60U. Automatic analysis of the neutron-γ pulse shape discrimination is a key issue to diminish the processing time in the DSP system, and it has been applied using the two-dimensional (2D) map. Linear discriminant function is used to determine the dividing line between neutron events and γ-ray events on a 2D map. In order to verify the validity of the dividing line determination, the pulse shape discrimination quality is evaluated. As a result, the γ-ray contamination in most of the beam heating phase was negligible compared with the statistical error with 10 ms time resolution.

Detection of lost alpha particle by concealed lost ion probe

Full orbit-following calculation is performed for the final orbit of the lost alpha particles, showing some orbits escaping from the last closed flux surface could be detected by a concealed lost ion probe (CLIP) installed under the shadow of the original first wall surface. While both passing and trapped orbits hit the same wall panel, detecting a trapped orbit by the CLIP is easier than detecting passing orbits. Whether the final orbit is detected or not is determined by the position of the reflection point. The CLIP successfully detects the trapped orbits, which are reflected before they hit to a first wall. Then the pitch angles of the orbits at the CLIP are close to and smaller than 90°. Optimization of the position of the CLIP in terms of broader detection window is investigated.

Effect of an immunotoxin to folate receptor beta on bleomycin-induced experimental pulmonary fibrosis

It has been suggested that alveolar and interstitial macrophages play a key role in the pathogenesis of idiopathic pulmonary fibrosis (IPF) by producing proinflammatory and/or fibrogenic cytokines. We showed that inflammatory macrophages expressed folate receptor beta (FRbeta) while resident macrophages in normal tissues expressed no or low levels of FRbeta. In the present study, we examined the distribution of FRbeta-expressing macrophages in the lungs of patients with usual idiopathic pulmonary fibrosis (UIP) and mice with bleomycin-induced pulmonary fibrosis (PF) and tested whether the depletion of FRbeta-expressing macrophages could suppress bleomycin-induced PF in mice. Immunostaining with anti-human or -mouse FRbeta monoclonal antibody (mAb) revealed that FRbeta-expressing macrophages were present predominantly in fibrotic areas of the lungs of patients with UIP and mice with bleomycin-induced PF. Intranasal administration of a recombinant immunotoxin, consisting of immunoglobulin heavy and light chain Fv portions of an anti-mouse FRbeta mAb and truncated Pseudomonas exotoxin A, increased survival significantly and reduced levels of total hydroxyproline and fibrosis in bleomycin-induced PF. In immunohistochemical analysis, decreased numbers of tumour necrosis factor-alpha-, chemokines CCL2- and CCL12-producing cells were observed in the immunotoxin-treated group. These findings suggest a pathogenic role of FRbeta-expressing macrophages in IPF. Thus, targeting FRbeta-expressing macrophages may be a promising treatment of IPF.

Fine-structure characteristics in the emittance images of a strongly focusing He+ beam

The phase space distribution of a strongly focused He(+) ion beam source equipped with concave multiaperture electrodes was measured using a pepper-pot plate and a Kapton foil. The substructure of 301 merging He beamlets was clearly observed on a footprint of pepper-pot hole at the beam waist, where the beam density was 500 mA/cm(2). The position and the width of each beamlet substructure show the effect of interference of beamlets with surrounding one.

Mass screening of prostate cancer and its impact on inhabitants in Akita Prefecture, Japan

In 2001, the Akita Medical Association started a prostate cancer (PC) mass screening project for >or= 50-year-old male inhabitants in individual municipalities of Akita Prefecture, utilizing serum prostate-specific antigen. The number of examinees increased from 4321 in 2001 to 29,936 in 2006, while the annual rate of examinees per target inhabitants remained at 11.6 to 16.8% and the fraction of repeat examinees increased up to 77% in 2006. A total of 944 PCs were screened with a stage B tumor incidence of 84.1% (range: 82.2 to 86.6%). The annual PC detection rate was 0.95 to 1.11% for the first 4 years, but then declined to 0.54% in 2006 mainly due to the increase of repeat examinees. PSA mass screening is effective for the detection of early stage PC, but a further promotion is needed to mobilize the sleeping inhabitants. Indeed, the number of new PC patients in 17 major hospitals in Akita Prefecture rapidly increased after the mass screening started (3.2-fold), suggesting an enlightenment effect of the screening project on both the inhabitants and general physicians.

Oncogenic role of nuclear accumulated Aurora-A

Aurora-A, also known as Aik, BTAK, or STK15, is a centrosomal serine/threonine protein kinase, which is proto-oncogenic and is overexpressed in a wide range of human cancers. Besides gene amplification and mRNA overexpression, proteolytic resistance mechanisms are thought to contribute to overexpression of Aurora-A. However, it is not yet clear how overexpressed Aurora-A affects the expression of transformed phenotype. Here, we found that nuclear accumulation of Aurora-A was critical for transformation activity. Cellular protein fractionation experiments and immunoblot analysis demonstrated a predominance of Aurora-A in the nuclear soluble fraction in head and neck cancer cells. Indirect immunofluorescence using confocal laser microscopy confirmed nuclear Aurora-A in head and neck cancer cells, while most oral keratinocytes exhibited only centrosomal localization. The expression of nuclear export signal-fused Aurora-A demonstrated that the oncogenic transformation activity was lost on disruption of the nuclear localization. Thus, the cytoplasmic localization of overexpressed Aurora-A previously demonstrated by immunohistochemical analysis is not likely to correspond to that in intact cancer cells. This study identifies an alternative mode of Aurora-A overexpression in cancer, through nuclear rather than cytoplasmic functions. We suggest that substrates of Aurora-A in the cell nuclear soluble fraction can represent a novel therapeutic target for cancer.

Activation of p38 mitogen-activated protein kinase is required for in vivo brain-derived neurotrophic factor production in the rat hippocampus

Several lines of evidence strongly suggest that brain-derived neurotrophic factor (BDNF) is associated with the formation, storage and recall of memory in the hippocampus and that it is important to maintain a considerable level of hippocampal BDNF in order to keep normal functions. BDNF can be synthesized in an activity-dependent manner. In fact, kainic acid or AMPA enhances BDNF levels in hippocampal granule neurons. However, the mechanisms of BDNF production are largely unclear. Recently, we have found that riluzole, which blocks voltage-gated sodium channels and thereby reduces glutamate release, actually strengthens immunoreactivity of BDNF in hippocampal granule neurons of rats. Therefore, we examined the riluzole-activated signaling pathways for BDNF production. Riluzole increased levels of phospho-p38 mitogen-activated protein kinase (p38 MAPK), as well as BDNF levels. Inhibition of p38 MAPK by SB203580 reduced riluzole effects, while activation of p38 MAPK by anisomycin increased levels of BDNF, suggesting that p38 MAPK can mediate BDNF production. Riluzole-induced elevation of phospho-activating transcription factor-2, a transcription factor downstream of p38 MAPK, was also observed. A blocker of N-type voltage-gated calcium channels reduced the effects of riluzole on BDNF production and p38 MAPK activation. We also examined a possible involvement of the adenosine A1 receptor in BDNF production because riluzole can influence ecto-nucleotide levels. An A1 receptor agonist inhibited riluzole-induced elevation of BDNF levels, whereas an antagonist not only increased levels of BDNF and active p38 MAPK but also augmented riluzole effects. These results indicate that, in the rat hippocampus, there is an in vivo signaling pathway for BDNF synthesis mediated by p38 MAPK, and that N-type voltage-gated calcium channels and/or adenosine A1 receptors contribute to p38 MAPK activation.

[Aortitis syndrome with repeated restenoses of a drug eluting stent]

The patient was a 49-year-old female who developed acute myocardial infarction of the right coronary artery in August 2005. In a short period of time, the patient had restenosis repeatedly after percutaneous coronary intervention (PCI). Restenosis could not be prevented even with a drug eluting stent (DES), and thus, off-pump coronary artery bypass grafting (OPCAB) was performed. The diagnosis of aortitis syndrome was made due to protracted postoperative inflammation. Aortitis syndrome was determined to be the main cause of repeated restenosis. This case was a middle-aged female who had restenosis in a short period of time, and aortitis syndrome should have been included in the differential diagnosis. Although some positive results have been reported on DES placement for coronary lesions of aortitis syndrome, DES was completely ineffective in our patient. Further studies with more patients are necessary to examine the effectiveness of DES.

ATF3 and p15PAF are novel gatekeepers of genomic integrity upon UV stress

After genotoxic stress, normal cells trigger DNA repair or, if unable to repair, undergo apoptosis to eradicate the cells that bear the risk of becoming tumorigenic. Here we show that repression of the transcription factor, activating transcription factor 3 (ATF3), after ultraviolet (UV)-mediated genotoxic stress impairs the DNA repair process. We provide evidence that ATF3 directly regulates the proliferating cell nuclear antigen (PCNA)-associated factor KIAA0101/p15(PAF). We further show that the expressions of ATF3 and p15(PAF) is sufficient to trigger the DNA repair machinery, and that attenuation of their expression alters DNA repair mechanisms. We show that the expression of p15(PAF) compensates for a lack of ATF3 expression, thereby constituting a major effector of ATF3 in the DNA repair process. In addition, we provide evidence that p15(PAF) expression is required for the correct function of PCNA during DNA repair, as prevention of their interaction significantly alters DNA repair mechanisms. Finally, defective DNA repair, because of the downregulation of p15(PAF) expression, rendered the cells more sensitive to UV-induced cell death. Therefore, our results suggest ATF3 and p15(PAF) as novel gatekeepers of genomic integrity after UV exposure.

Effects of filament geometry on the arc efficiency of a high-intensity He+ ion source

A strongly focusing high-intensity He(+) ion source equipped with three concave electrodes has been designed and constructed as the beam source for a high-energy He(0) neutral beam probe system to diagnose fusion-produced alpha particles in thermonuclear fusion plasmas. The reduction of heat load onto the concave extraction electrodes is particularly important for a long pulse operation, as the heat load deforms the electrodes and thus the beam focal length. The effects on the arc efficiency (beam current/arc power) of the ion source due to the discharge filament structure (straight-type and L-shape-type filaments), size (filament diameters of 2 and 1.5 mm), number, and the locations have been studied. Choice of the appropriate filament structure improved the arc efficiency by 17%.

Full orbit calculation for lost alpha particle measurement on ITER

An orbit following calculation code with full gyromotion under the ITER magnetic field configuration has been developed to investigate escaping alpha particle orbits in ITER and to determine the geometrical arrangement for alpha particle detection. The code contained the full geometrical information of the first wall panels. It was carefully investigated whether an alpha particle escaping from the plasma through the last closed flux surface does not touch or intersect the first wall boundary before reaching the detection point. Candidates of blanket module modification have been studied to achieve effective measurement geometry for escaping alpha particle detection. The calculations showed that direct orbit loss and banana diffusion can be detected with a probe head recessed from the first wall surface.