Neutron resonance absorption imaging of simulated high-level radioactive waste in borosilicate glass.

We performed a preliminary study of neutron resonance absorption imaging to investigate the spatial distribution of constituent elements in borosilicate glasses containing simulated high-level radioactive waste, in which elemental inhomogeneities affect the physical and chemical stabilities of the glass. Dips generated by the resonance absorptions of Rh, Pd, Na, Gd, Cs, and Sm were observed in the neutron transmission spectra of the glass samples. The spatial distributions of these elements were obtained from the neutron transmission images at the resonance energies. The distributions of Rh and Pd visualized the sedimentation of these platinum group elements. In contrast, the lanthanides (Gd and Sm) and Cs were uniformly dispersed. These results show that neutron resonance absorption imaging is a promising tool for characterizing borosilicate glasses and investigating the vitrification mechanism of high-level radioactive waste.

An experimental setup for creating and imaging 4He2 * excimer cluster tracers in superfluid helium-4 via neutron-3He absorption reaction.

For the purpose of future visualization of the flow field in superfluid helium-4, clusters of the triplet state excimer 4He2 * are generated along the micro-scale recoil tracks of the neutron-absorption reaction n + 3He → 3T + p. This reaction is induced by neutron irradiation of the 3He fraction contained in natural isotopic abundance liquid helium with neutron beams either from the Japan Proton Accelerator Research Complex, Materials and Life Science Experimental Facility (JPARC)/Materials and Life Science Experimental Facility or from the Kyoto University Institute for Integrated Radiation and Nuclear Science. These 4He2 * clusters are expected to be ideal tracers of the normal-fluid component in superfluid helium with several advantageous properties. Evidence of the excimer generation is inferred by detection of laser induced fluorescence emitted from the 4He2 * clusters excited by a purpose-built short pulse gain-switched titanium:sapphire (Ti:sa) laser operating at a wavelength of 905 nm. The setup and performance characteristics of the laser system including the Ti:sa and two continuous wave re-pumping lasers are described. Detection at the fluorescence wavelength of 640 nm is performed by using optical bandpass filtered photomultiplier tubes (PMT). Electrical noise in the PMT acquisition traces could successfully be suppressed by post-processing with a simple algorithm. Despite other laser-related backgrounds, the excimer was clearly identified by its fluorescence decay characteristics. Production of the excimer was found to be proportional to the neutron flux, adjusted via insertion of different collimators into the neutron beam. These observations suggest that the apparatus we constructed does function in the expected manner and, therefore, has the potential for groundbreaking turbulence research with superfluid helium.

Treatment with the MAPK kinase inhibitor U0126 during the first two hours of in vitro maturation improves bovine oocyte developmental competence.

This study examined the effects of treatment with U0126, which inhibits MAPK by inhibiting MAPK kinase, during the first 2 hr of in vitro maturation on bovine developmental competence and on gap junction (GAPJ) communication between the oocyte and cumulus cells. The percentage of oocytes developing to the blastocyst stage in the group treated with 5 µM U0126 (28%) was significantly higher than that in controls (15%, p < .05), while that in the group treated with 10 µM U0126 (18%) was not. Breakdown of the GAPJs was delayed in the group treated with 5 µM U0126 when compared to controls, as estimated by immunohistochemical examination of connexin 43, which is a primary constituent of the GAPJs. These results indicate that treatment with 5 µM U0126 during in vitro maturation delays GAPJ breakdown and improves bovine oocyte developmental competence.

Hyaluronan metabolism in overloaded temporomandibular joint.

This study aimed to examine hyaluronan (HA) metabolism in relation to the onset and progression of temporomandibular joint osteoarthritis (TMJ-OA) induced by mechanical overloading. Two-month-old and 6-month-old C57BL/6N mice were divided into experimental and untreated control groups (n = 5/group). A sliding plate was attached to the maxillary incisors of the experimental mice for 10 days to overload the condylar cartilage in TMJ. In experimental group, profound cartilage degradation was detected in haematoxylin-eosin, Safranin-O-Fast Green-stained sections. It was also shown that the cartilage degradation was greater in older mice in both the control and the experimental groups. The number of HABP-positive cells was decreased by mechanical overloading and with age. The reduction of HA expression was correlated with the progression of cartilage degradation induced by mechanical overloading. The absolute quantification of the mRNA expression related to HA synthesis and HA degradation was also performed in each group. The mRNA expression levels of HA synthase (HAS) 2 and 3 were lower in the experimental group compared with the control group in the younger mice. In contrast, the mRNA expression levels of the HA degradation gene, HYAL2 and KIAA1199, were higher in the experimental group compared with the control group in the older mice. Thus, mechanical overload differently affected the balance of HA degradation and HA synthesis in the older and younger mice, respectively. In conclusion, mechanical overloading affects HA metabolism and it might initiate or amplify the condylar cartilage degradation.

Simple debridement has little useful value on the clinical course of recalcitrant ulnar wrist pain.

The purpose of this study was to evaluate treatment results following arthroscopic triangular fibrocartilage complex (TFCC) debridement for recalcitrant ulnar wrist pain. According to the treatment algorithm, 66 patients (36 men and 30 women with a mean age of 38.1 years (15 to 67)) with recalcitrant ulnar wrist pain were allocated to undergo ulnar shortening osteotomy (USO; n = 24), arthroscopic TFCC repair (n = 15), arthroscopic TFCC debridement (n = 14) or prolonged conservative treatment (n = 13). The mean follow-up was 36.0 months (15 to 54). Significant differences in Hand20 score at 18 months were evident between the USO group and TFCC debridement group (p = 0.003), and between the TFCC repair group and TFCC debridement group (p = 0.029). Within-group comparisons showed that Hand20 score at five months or later and pain score at two months or later were significantly decreased in the USO/TFCC repair groups. In contrast, scores in the TFCC debridement/conservative groups did not decrease significantly. Grip strength at 18 months was significantly improved in the USO/TFCC repair groups, but not in the TFCC debridement/conservative groups. TFCC debridement shows little benefit on the clinical course of recalcitrant ulnar wrist pain even after excluding patients with ulnocarpal abutment or TFCC detachment from the fovea from the indications for arthroscopic TFCC debridement.

Evaluation of floating impeller phenomena in a Gyro centrifugal pump.

The Gyro centrifugal pump developed as a totally implantable artificial heart was designed with a free impeller, in which the rotational shaft (male bearing) of the impeller was completely separated from the female bearing. For this type of pump, it is very important to keep the proper magnet balance (impeller-magnet and actuator-magnet) in order to prevent thrombus formation and/or bearing wear. When the magnet balance is not proper, the impeller is jerked down into the bottom bearing. On the other hand, if magnet balance is proper, the impeller lifted off the bottom of the pump housing within a certain range of pumping conditions. In this study, this floating phenomenon was investigated in detail. The floating phenomenon was proved by observation of the impeller behavior using a transparent acrylic pump. The impeller floating phenomenon was mapped on a pump performance curve. The impeller floating phenomenon is affected by the magnet-magnet coupling distance and rotational speed of the impeller. In order to keep the proper magnet balance and to maintain the impeller floating phenomenon at the driving condition of right and left pump, the magnet-magnet coupling distance was altered by a spacer which was installed between the pump and actuator. It became clear that the same pump could handle different conditions (right and left ventricular assist), by just changing the thickness of the spacer. When magnet balance is proper, the floating impeller phenomenon occurs automatically in response to the impeller rev. It is called "the dynamic RPM suspension".

[Rib-originated fibrous dysplasia: report of a case].

The incidence of fibrous dysplasia (FD) is not frequent in the case of benign bone tumors of the chest wall, and differential diagnosis between FD and the malignancy on the basis of imaging findings is difficult. We report a case of a painful FD lesion (size, 9×8 cm) that originated from the 5th rib of a 52-year-old man and was surgically resected. His symptoms improved after the operation. Painful and large FD lesions should be resected because of a difficulty in differential diagnosis from malignant tumors.

Low glucose under hypoxic conditions induces unfolded protein response and produces reactive oxygen species in lens epithelial cells.

Aging is enhanced by hypoxia and oxidative stress. As the lens is located in the hypoglycemic environment under hypoxia, aging lens with diabetes might aggravate these stresses. This study was designed to examine whether low glucose under hypoxic conditions induces the unfolded protein response (UPR), and also if the UPR then generates the reactive oxygen species (ROS) in lens epithelial cells (LECs). The UPR was activated within 1 h by culturing the human LECs (HLECs) and rat LECs in <1.5 mM glucose under hypoxic conditions. These conditions also induced the Nrf2-dependent antioxidant-protective UPR, production of ROS, and apoptosis. The rat LECs located in the anterior center region were the least susceptible to the UPR, whereas the proliferating LECs in the germinative zone were the most susceptible. Because the cortical lens fiber cells are differentiated from the LECs after the onset of diabetes, we suggest that these newly formed cortical fibers have lower levels of Nrf2, and are then oxidized resulting in cortical cataracts. Thus, low glucose and oxygen conditions induce the UPR, generation of ROS, and expressed the Nrf2 and Nrf2-dependent antioxidant enzymes at normal levels. But these cells eventually lose reduced glutathione (GSH) and induce apoptosis. The results indicate a new link between hypoglycemia under hypoxia and impairment of HLEC functions.

Deficiency of Prdx6 in lens epithelial cells induces ER stress response-mediated impaired homeostasis and apoptosis.

The multifunctional cytoprotective protein peroxiredoxin 6 (Prdx6) maintains cellular homeostasis and membrane integrity by regulating expression of intracellular reactive oxygen species (ROS) and phospholipid turnover. Using cells derived from targeted inactivation of Prdx6 gene or its depletion by RNA interference or aging, we showed that Prdx6 deficiency in cells evoked unfolded protein response (UPR), evidenced by increased expression or activation of proapoptotic factors, CHOP, ATF4, PERK, IRE-α and eIF2-α and by increased caspases 3 and 12 processing. Those cells displayed enhanced and sustained expression of endoplasmic reticulum (ER) stress-related chaperon proteins, Bip/glucose-regulated protein 78, calnexin, and calreticulin. Under cellular stress induced by hypoxia (1% O(2) or CoCl(2) treatment) or tunicamycin, Prdx6-deficient cells exhibited aberrant activation of ER stress-responsive genes/protein with higher expression of ROS, and died with apoptosis. Wild-type cells exposed to tunicamycin or hypoxia remained relatively insensitive with lower expression of ROS and ER-responsive genes than did Prdx6-deficient cells, but upregulation of ER stress responsive proteins or chaperones mimicked the UPR response of Prdx6-deficient or aging cells. Expression of Prdx6 blocked ER stress-induced deleterious signaling by optimizing physiologically aberrant expression of ER stress responsive genes/proteins in Prdx6-deficient cells or cells facing stressors, and rescued the cells from apoptosis. These findings demonstrate that impaired homeostasis and progression of pathogenesis in Prdx6-deficient lens epithelial cells or in aging cells should be blocked by a supply of Prdx6. The results provide a new molecular basis for understanding the etiology of several age-associated degenerative disorders, and potentially for developing antioxidant Prdx6-based therapeutics.

Association of incompleteness of the anterior part of the circle of Willis with the occurrence of lacunes in the basal ganglia.

BACKGROUND AND PURPOSE: This study investigated whether incompleteness of the anterior part of the circle of Willis affects the occurrence of lacunes in the basal ganglia. METHODS: One thousand and seventy-seven healthy individuals examined by magnetic resonance (MR) imaging and MR angiography were divided into eight subgroups according to our new classification. RESULTS: Logistic regression analysis demonstrated that healthy individuals with incompleteness of the anterior circle of Willis had significantly higher frequency of lacunes [odds ratio (OR): 2.121, 95% confidence interval (CI): 1.477-3.108; or OR: 2.46, 95% CI: 1.377-4.384 in cases without or with fetal type posterior communicating artery, respectively] and higher numbers of lacunes (P < 0.001 or P < 0.001 in cases without or with fetal type posterior communicating artery, respectively) compared to patients with complete circle of Willis. CONCLUSIONS: Incompleteness of the anterior part of the circle of Willis significantly affected the occurrence of lacunes.

Development and validation of an illustrated questionnaire to evaluate disabilities of the upper limb.

We have developed an illustrated questionnaire, the Hand20, comprising 20 short and easy-to-understand questions to assess disorders of the upper limb. We have examined the usefulness of this questionnaire by comparing reliability, validity, responsiveness and the level of missing data with those of the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire. A series of 431 patients with disorders of the upper limb completed the Hand20 and the Japanese version of the DASH (DASH-JSSH) questionnaire. The norms for Hand20 scores were determined in another cross-sectional study. Most patients had no difficulty in completing the Hand20 questionnaire, whereas the DASH-JSSH had a significantly higher rate of missing data. The standard score for the Hand20 was smaller than the reported norms for the DASH. Our study showed that the Hand20 questionnaire provided validation comparable with that of the DASH-JSSH. Explanatory illustrations and short questions which were easy-to-understand led to better rates of response and fewer missing data, even in elderly individuals with cognitive deterioration.

Secretion of intelectin-1 from malignant pleural mesothelioma into pleural effusion.

BACKGROUND: Malignant pleural mesothelioma (MPM) is a rare but fatal tumour. Although most MPM patients show pleural effusion at even the early stage, it is hard to diagnose as MPM at the early stage because a sensitive and reliable diagnostic marker for MPM has not been found in plasma or pleural effusion. METHODS: In this study, we investigated whether intelectin-1 was specifically contained in MPM cells and the pleural effusion of MPM patient by immunohistochemistry, western blotting, and enzyme-linked immunosorbent assay. RESULTS: Malignant pleural mesothelioma cell lines, but not lung adenocarcinoma cell lines, secreted intelectin-1. In immunohistochemistry, epithelioid-type MPMs, but neither pleura-invading lung adenocarcinomas nor reactive mesothelial cells near the lung adenocarcinomas, were stained with anti-intelectin antibodies. Pleural effusion of MPM patients contained a higher concentration of intelectin-1 than that of lung cancer patients. CONCLUSION: These results suggest that detection of intelectin-1 may be useful for a differential diagnosis of epithelioid-type MPM in immunohistochemistry and that a high concentration of intelectin-1 in pleural effusion can be used as a new marker for clinical diagnosis of MPM.

New squatting test indices are useful for assessing baroreflex sensitivity in diabetes mellitus.

AIMS: The heart rate (HR) responses after performance of the squatting and standing manoeuvre are thought to be a useful tool to assess autonomic neuropathy in diabetics. Our aim was to develop new simple squatting test indices and to analyse their applicability to the assessment of baroreflex sensitivity (BRS) in patients with diabetes. METHODS: Twenty healthy volunteers (mean age 23.2 +/- 3.8 years) and 51 patients with diabetes (mean age 55.9 +/- 10.6 years) were enrolled in study 1 and study 2, respectively. Each subject stood for 3 min (basal period), then squatted down for 1 min (Sq) and stood up again for 1 min (St). In study 1, the squatting test was performed before and after pharmacological autonomic blockade. In study 2, we measured HR in each period and calculated the difference between basal HR and HRSq (DeltaHRSq) and between HRSt and HRSq (DeltaHRSt). BRS was also measured using the phenylephrine method in diabetic patients. RESULTS: In healthy individuals during autonomic blockade, HR changes were mainly controlled by the vagal tone during squatting and by the sympathetic tone during standing. In diabetic patients, DeltaHRSq and DeltaHRSt positively correlated (r = 0.86, P < 0.0001) and both DeltaHRSq and DeltaHRSt significantly correlated with BRS (r = 0.66, P < 0.0001 and r = 0.61, P < 0.0001, respectively). CONCLUSIONS: The new squatting test indices provide useful information for assessing autonomic neuropathy and for identifying diabetic patients at high risk of cardiovascular events.

Brief history, pitfalls, and prospects of mammalian spermatogonial stem cell research.

Spermatogonial stem cells (SSCs) provide the foundation for spermatogenesis. During the last decade, several techniques for the manipulation of this cell type have been developed; as a result, SSCs can now be subjected to long-term in vitro expansion and genetically manipulated for knockout mouse production. These techniques have allowed SSCs to serve as a new target for animal transgenesis, which may provide an alternative to embryonic stem (ES) cells. Furthermore, SSCs may be converted into ES-like cells, demonstrating that the postnatal testis is a source of pluripotent stem cells. These techniques were first established in mice, but they are currently being extended to other animal species. SSC-based technologies will be useful in agriculture and medicine and will also provide valuable opportunities to study SSC biology. The mechanisms of self-renewal division and differentiation and the regulation of pluripotency in SSCs are now being studied at the molecular level. However, some technical and conceptual pitfalls must be kept in mind when designing and analyzing experimental results. Nevertheless, these advances in SSC research will provide valuable insight into the study of mammalian stem cell systems.

Thoracic chordoma: review and role of FDG-PET.

Chordoma is an uncommon primary bone tumor and the thoracic spine is the least common of all sites for a chordoma. It may recur despite slow-growing nature. Precise literature review will be performed and possible use of fluorine-18-fluorodeoxyglucose (FDG) positron emission tomography (PET) for detection of both primary and recurrent diagnosis will be discussed. This article presents the case of a 73-year-old male patient who complained of back pain. Magnetic resonance (MR) imaging, computed tomography (CT) and FDG-PET demonstrated thoracic lesion and biopsy revealed chordoma. The patient was operated on and histological findings showed the tumor was chondroid chordoma. He suffered recurrence after 7 months by FDG-PET. He received 6,000 rads radiation therapy and is neurological free but, suffered backache 15 months after initial diagnosis. Only 12 cases including this case were reported precisely and this is the first report of FDG-PET for both initial and recurrent diagnosis of chordoma.