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Direct quantitative assessment of health risks following exposure to ionizing radiation is based on findings from epidemiological studies. Populations affected by nuclear bomb testing are among those that allow such assessment. The population living around the former Soviet Union's Semipalatinsk nuclear test site is one of the largest human cohorts exposed to radiation from nuclear weapons tests. Following research that started in the 1960s, a registry that contains information on more than 300,000 individuals residing in the areas neighboring to the test site was established. Four nuclear weapons tests, conducted from 1949 to 1956, resulted in non-negligible radiation exposures to the public, corresponding up to approximately 300 mGy external dose. The registry contains relevant information about those who lived at the time of the testing as well as about their offspring, including biological material. An international group of scientists worked together within the research project SEMI-NUC funded by the European Union, and concluded that the registry provides a novel, mostly unexplored, and valuable resource for the assessment of the population risks associated with environmental radiation exposure. Suggestions for future studies and pathways on how to use the best dose assessment strategies have also been described in the project. Moreover, the registry could be used for research on other relevant public health topics. [ABSTRACT FROM AUTHOR]

Local failure after definitive chemoradiotherapy ( CRT) for stage IB, II, and III esophageal cancer is one of the causes of poor outcome. Endoscopic mucosal resection ( EMR) is an effective treatment for superficial esophageal cancer. However, its feasibility as a salvage treatment for local recurrent or residual tumors after definitive CRT for stage IB, II, and III esophageal cancer remains unclear. Between January 2000 and February 2008, 274 patients with stage IB, II, and III esophageal squamous cell cancer excluding T4 received definitive CRT at the National Cancer Center Hospital, Japan. Of these patients, nine patients with local recurrence after achieving complete response and two patients with residual tumor underwent salvage EMR. The technique of salvage EMR involved a strip biopsy method. We retrospectively reviewed the 11 patients (13 lesions). Characteristics of all 11 patients were as follows: median age of 69 (range: 45-78); male/female: 10/1; baseline clinical stage ( Union for International Cancer Control 7th) IB/ IIA/ IIB/ III: 1/3/7/0. The depth of resected tumor was limited to the mucosal layer in seven lesions and submucosal in six lesions. En bloc resection was performed on six lesions (46%). The vertical margin was free of cancer cells in 11 lesions (84.6%). No major complications, such as hemorrhage requiring blood transfusion and perforation, were experienced. At a median follow-up period of 38.9 months (range: 5.3-94 months) after salvage EMR, no recurrence was detected in six patients (54%). Local recurrence was detected in five patients (27%). Of these patients, two had lung metastasis simultaneously, and one was also detected lung metastasis 2 months after the detection of local recurrence. The 5-year survival rate after salvage EMR was 41.6%. Salvage EMR is a feasible treatment option for local recurrent or residual lesions after definitive chemotherapy and/or radiotherapy for stage IB, II, and III esophageal squamous cell cancer. [ABSTRACT FROM AUTHOR]

Background and study aims: Gastrectomy with lymph node dissection is the gold standard curative treatment for clinical submucosal invasive early gastric cancer (cSM EGC), but a relatively small number of operable patients with cSM EGC have undergone endoscopic submucosal dissection (ESD) instead because they refused surgery. The aim of this study was to determine the effectiveness of ESD in these operable patients. Methods: The therapeutic outcomes of ESD were retrospectively assessed for 38 patients with 38 operable cSM EGC lesions who initially refused surgery at the National Cancer Center Hospital, Tokyo, from January 1999 to December 2008. Results: The en bloc resection rate was 84.2% (32 lesions) and the complete (R0) resection rate was 63.2% (24 lesions). A total of 33 lesions (86.8 %) involved submucosal invasion on pathology. Resection was non-curative in 34 patients (89.5 %), 22 of whom (64.7 %) underwent subsequent gastrectomy after the need for such surgery was carefully explained to them again. The median follow-up period was 73.2 months (range 3-115 months). Local recurrence was detected in one patient, distant metastasis in two patients, and both local recurrence and distant metastasis were detected in one patient. None of these four patients with recurrence (10.5 %) had undergone surgery when their recurrent disease was detected and all of them died from gastric cancer. The 5-year cause-specific survival rate for all patients was 91.8 %. Conclusion: The 5-year cause-specific survival rate for all patients was lower than the previously reported rate of 96.7% for pathologically submucosal invasive EGC patients after gastrectomy; therefore, ESD appears to have been an ineffective treatment for operable patients with cSM EGC. [ABSTRACT FROM AUTHOR]

In the last few decades attention has been given to improve workplace conditions, primarily to reduce the different health risks. In the air that accumulates in underground workplaces radon may constitute one of the health risks. The radon concentration in the show cave in Tapolca is especially high in summer months, with the annual average in the year 2005 being 7227 Bq/m3, in 2006 8591 Bq/m3. The radon concentration was found to be independent on the location of the measurement. Its value was rather similar for working hours and for the total period. The hours spent in the cave by the workers depend on the number of visitors. The radiation dose, estimated on the basis of personal dosimeters, is significant for those working there especially, employed during the whole year. Taking into consideration the actual working hours and the equilibrium factor, F = 0.4, given in the literature, it approaches and even exceeds the dose limit of 20 mSv/year. With a well organized work schedule, as well as the employment of outside workers during the summer period, the dose limit of 20 mSv/year can probably be maintained. However, on the basis of recent measurements, the actual equilibrium factor was determined to be F = 0.5, which in turn means a further 25% increase in the dose effect. [ABSTRACT FROM AUTHOR]

Background: Impairment of gastric emptying is well recognized in patients with diabetes mellitus (DM), especially long-standing insulin-dependent diabetes mellitus (IDDM). The aim of this study was to evaluate the cause of delayed gastric emptying in DM patients.Methods: In 16 controls, 16 non-insulin-dependent diabetes mellitus (NIDDM) patients and 23 IDDM patients, gastric emptying was studied using the (13)C octanoic acid breath test. Breath samples were taken before a test meal labeled with 100 mg of (13)C octanoic acid, and at 15-min intervals over a 300-min period postprandially.Results: In all DM patients, the gastric emptying coefficient was lower than that in the controls (P < 0.05), and lag time and half-emptying time were significantly longer (P < 0.05). Both NIDDM and IDDM patients showed delayed (13)CO(2) excretion compared with the controls, but IDDM patients showed more delayed gastric emptying than NIDDM patients (P < 0.05). There were no significant differences in sex, HbA1c level, or the rate of neuropathy between the two groups.Conclusions: IDDM patients showed delayed gastric emptying compared with NIDDM patients, and the (13)C octanoic acid breath test is useful for evaluating DM patients with delayed gastric emptying. [ABSTRACT FROM AUTHOR]

A preliminary survey of airborne and waterborne radon concentrations was given for an area where groundwater is used as a source of public water supply. The average of the waterborne radon concentrations was 77 Bq/l for 36 samples and that of airborne radon concentrations was 18 Bq/m3for ten houses. It is concluded that the exposure dose due to radon-in-water is likely to be much smaller than the total dose from natural radiation. [ABSTRACT FROM AUTHOR]

A DeNOx process using a DC corona discharge was investigated experimentally. A mixture system of N2/O2/NO was used as a test gas. The compositions such as NO, NO2, N2O and so on were analyzed with Fourier transform infrared spectroscopy and an NOx meter. It was found that the characteristics of NO removal by corona discharge differed remarkably whether or not oxygen exists in the mixture. In regard to the spectrum of light emission from the corona discharge in N2 atmosphere or N2/O2 mixture, some N2 bands were detected. N2 dissociation into atomic N and N2 radical in the corona discharge field was conjectured. Furthermore, ozone was yielded by the corona discharge in the case of the N2/O2 mixture. Ozone gas from an ozonizer was added into the N2/O2 mixture without corona discharge to investigate the effect of O3 on the characteristics of NOx removal by corona discharge. In the case of the N2/NO mixture, the process of NO reduction was mainly controlled by N2 radicals excited by the corona discharge. On the other hand, in the case of the N2/O2/NO mixture, NO was oxidized by ozone generated from the corona discharge and converted to NO2 and N2O5. [ABSTRACT FROM AUTHOR]

B7-H3, a member of the B7 family of the Ig superfamily proteins, is expressed on the surface of the antigen-presenting cells and down-regulates T cell functions by engaging an unknown counter receptor on T cells. Although B7-H3 is ubiquitously expressed, its potential nonimmune functions have not been addressed. We found that B7-H3 is highly expressed in developing bones during embryogenesis and that its expression increases as osteob last precursor cells differentiate into mature osteoblasts. In vitro bone formation by osteoblastic cells was inhibited when B7-H3 function was interrupted by the soluble recombinant protein B7-H3-Fc. Analysis of calvarial cells derived from neonatal B7-H3 knockout (KO) mice revealed normal numbers of osteoblast precursor cells possessing a normal proliferative capacity. However, the B7-H3- deficient calvarial cells exhibited impaired osteogenic differentiation, resulting in decreased mineralized bone formation in vitro. These results suggest that B7-H3 is required for the later phase of osteoblast differentiation. Although B7-H3 KO mice had no gross skeletal abnormalities, they displayed a lower bone mineral density in cortical (but not trabecular) bones compared with WT controls. Consistent with the reduced bone mineral density, the femurs of B7-H3 KO mice were more susceptible to bone fracture compared with those of WT mice. Taken together, these results indicate that B7-H3 and its unknown counterreceptor play a positive regulatory role in bone formation. In addition, our findings identified B7-H3 as another molecule that has a dual role in the bone-immune interface. [ABSTRACT FROM AUTHOR]

In order to increase the cooling stability of the he lical coils, an upgrade of the cooling scheme is planned from 44 K pool-boiling to 3.0 K sub-cooled helium of flow rate of about 50 g/sec. We have designed and constructed a R&D coil made of the same superconductor as that used for the helical coils and a sub-cooled helium test facility on the assumption of the application for actual Large Helical Device (LHD). This facility is composed of decompression tank for the sub-cooled helium generation, the R&D coil, a current lead storage tank, etc., installed in a cryostat with a liquid nitrogen shield. Two stage cryogenic compressors are installed in the top flange, and sub-cooled helium is generated by decompressing of saturated liquid helium from 0.12 MPa to 24 kPa. Liquid helium of 4.4 K and 0.12 MPa is heat exchanged by the sub-cooled helium in the decompression tank and supplied to the R&D coil from the bottom. The sub-cooling R&D experiment has been carried out. As the results of experiment, we found that the saturated liquid helium could be cooled from 4.4 K to 3.0 K in 8 hours and maintained at 3.0 K. The rotation speed of the first and second stage cryogenic compressors were about 87,000 and 88,000 rpm, respectively. These values agreed well with the designed values of the two-stage cryogenic compressors. Finally, this facility operated stably during 8 days of the two sub-cooling R&D experiment campaigns. [ABSTRACT FROM AUTHOR]

Purpose : Ras activation is one of the major mechanisms for the development of murine thymic lymphomas by radiation and chemical carcinogens. To gain insight into the relationship between genetic susceptibility and ras gene mutation, the frequency and spectrum of ras gene mutation was examined in thymic lymphomas from susceptible and resistant mice. Materials and methods : K- and N- ras mutations in thymic lymphomas that arose in X-ray-irradiated and N -ethyl- N -nitrosourea (ENU)-treated mice of susceptible C57BL/6, rather resistant C3H and their hybrid B6C3F1 were analysed by polymerase chain reaction-single-strand conformation polymorphism and subsequent DNA sequencing. Results : C57BL/6 exhibited a higher incidence of thymic lymphomas after exposure to X-rays and ENU than C3H, with B6C3F1 being intermediate. K- ras gene mutations occurred frequently in the pathogenesis of ENU-induced thymic lymphomas in susceptible C57BL/6 as opposed to resistant C3H. The ras mutations were more frequent in ENU-induced thymic lymphomas than X-ray-induced thymic lymphomas, and with the latter, there was no clear evidence for strain differences, suggesting that the genetic susceptibility to X-rays was independent of ras activation. The mutations of K- ras in thymic lymphomas from C57BL/6 were predominantly GGT to GAT in codon 12, whereas this mutation type was never found in those from C3H. No strain difference was observed in the nucleotide sequence or expression levels of O 6 -alkylguanine alkyltransferase, indicating that this enzyme did not account for the genetic susceptibility to ras activation. Conclusions : The results indicate that there is a clear strain and carcinogen dependency of K- ras mutation and that the frequency of ras mutation might determine the genetic susceptibility to ENU-induced lymphomagenesis, whereas pathways independent of ras activation might determine the susceptibility to X-ray-induced lymphomagenesis. [ABSTRACT FROM AUTHOR]

We evaluated the protective effects of floor cover against soil erosion in three types of forest located on steep slopes under a humid climate: 22- and 34-year-old Chamaecyparis obtusa (hinoki), 34-year-old Cryptomeria japonica (sugi), and 62-year-old Pinus densiflora (red pine) stands. We measured sediment transport rates (sediment mass passing through one meter of contour width per millimeter of rainfall), using sediment traps, before and after removing floor cover. Raindrop splash erosion was dominant in the experimental stands. Floor cover percentage (FCP) during the preremoval stage varied from 50% to 100% among the four stands, and sediment transport rates ranged from 0.0079 to 1.7 g m-1 mm-1. The rates increased to 1.5–5.6 g m-1 mm-1 immediately after removing floor cover, and remained high throughout the experiment. The presence of physical cover near the ground has a crucial effect on sediment transport on forested slopes. The protective effect ratio (the ratio of the sediment transport rate in a control plot to that in the removal plot) in a young hinoki stand, in which the FCP decreased markedly, was 0.3 at most, which is close to the rate for bare ground. The protective effect ratio in the red pine stand was ≤0.003. We concluded that the protective effect of floor cover in undisturbed forests in Japan differs by over two orders of magnitude, based on comparisons with previous studies. [ABSTRACT FROM AUTHOR]

Objects: Sinus pericranii is only a symptom complex, and it can have a variety of etiologies. Therefore, it is important to differentiate these etiologies preoperatively by means of radiological examinations. A 5-year-old boy was admitted with a soft and fluctuant tumor in the right parietal region near the midline. The tumor appeared when the child was in a recumbent position, distending noticeably with the Valsalva maneuver and disappearing completely when the patient was in the sitting position. Methods: Magnetic resonance imaging showed the lesion with honeycomb-like heterogeneous iso- and low-intensity signals on the T1-weighted image and with heterogeneous high- and iso- intensity signal on the T2-weighted image. Dynamic study with an injection of gadolinium diethylene-triaminopentaacetic acid demonstrated and nodular peripheral enhancement at early phase and subsequent progressive enhancement towards the center of tumor. The internal carotid angiogram was normal. The external carotid angiogram, however, showed a tumor stain fed by the superficial temporal arteries. The stain was retained until the late phase and drained into the scalp veins and into the superior sagittal sinus. Following direct injection of contrast medium into the tumor there was prolonged retention of the medium in the tumor and leakage into scalp veins and the superior sagittal sinus. The mass under the periosteum was totally removed and proved to be a cavernous angioma. Conclusions: Scalp cavernous angioma is one of the etiologies of sinus pericranii and may be diagnosed preoperatively by cerebral angiography or magnetic resonance imaging. Serial dynamic magnetic resonance imaging will be particularly helpful for this diagnosis. [ABSTRACT FROM AUTHOR]