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Abstract: There is no convincing evidence that exposure to radon increases cancer risks other than lung cancer. We conducted a case-control study of residential radon exposure and childhood leukemia. A total of 255 incident cases of acute lymphoblastic and myeloid leukemia that were diagnosed at age <15, and 248 controls were included in analyses. Relative risks for radon level of 20–49, 50–99, and 100 Bq/m3 or more were 1.00 (95% CI, 0.62 to 1.62), 1.57 (95% CI, 0.47 to 5.22), and 2.05 (95% CI, 0.18 to 23.4), compared to less than 20 Bq/m3 (p for trend: 0.52). The present study provides no evidence for an association between residential radon exposure and childhood leukemia. [Copyright &y& Elsevier]

Abstract: The carcinogenic effect of radon has not been established except for lung cancer. We conducted a metaanalysis of published epidemiological studies on residential radon and childhood leukemia. Five case-control studies were identified, with a total of 1348 cases and 2057 controls. We used a log-linear regression model to obtain a summary estimate of radon-related risk in each study, based on adjusted odds ratios corresponding to categories for radon concentration. Overall estimate of relative risk at 150 Bq/m3 was 1.05 (95% CI: 0.90–1.21) based on random effect model. There is no evidence for an association between residential radon and childhood leukemia. [Copyright &y& Elsevier]

Abstract: A preliminary survey of airborne and waterborne radon concentrations was conducted in an area where groundwater is used as a source of public water supplies. An average of waterborne radon concentrations was 58.4 Bq l−1 for public water supplies and that of airborne radon concentrations was 18 Bq m−3 for 10 houses. [Copyright &y& Elsevier]

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]

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]

Abstract: A diagnostic technique that can estimate quantitatively wear amounts under lubricated condition was developed using our developed on-line particle counter. Wear tests were carried out by rubbing a bearing metal against a carbon steel in paraffin oil. The size and number of wear debris in the circulating oil could be measured in real time. The volume of each debris was calculated and, additionally, the total wear amount during a given duration was calculated by accumulating all debris volume. The wear amounts obtained by the quantitative estimation were fairly similar to the measured values of mass loss of the specimen. [Copyright &y& Elsevier]

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]

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]

PURPOSE: Few studies have evaluated cancer risk associated with low-dose occupational ionizing radiation exposure to women. We present data on incident cancer risks among a predominantly (77%) female cohort of 73,963 U. S. radiologic technologists followed up from 1983 through 1998.METHODS: Cancer incidence information and data on work history, selected cancer risk factors, personal radiation exposure and other health outcomes were obtained from two mailed questionnaires (administered ~1984 and ~1995). Incident cancers were ascertained from the second survey and supplemented by mortality records. Medical records, obtained for 74% of all self-reported cancers, confirmed the cancer in 85%. We computed standardized incidence ratios (SIR) using cancer incidence rates from the National Cancer Institute''s Surveillance Epidemiology and End Results Program.RESULTS: The SIR for all cancers combined in both sexes was 1.04 (95% confidence interval (CI): 1.00, 1.07; n = 3292). The incidence of solid cancers was elevated in women (SIR = 1.06, 95% CI: 1.02, 1.10), but lower than expected among men (SIR = 0.92 , 95% CI 0.85, 0.98). Female technologists had an elevated incidence of breast cancer (SIR = 1.16, 95% CI: 1.09, 1.23). Among both sexes combined, elevated risks were seen for melanoma (SIR = 1.59, 95% CI: 1.38, 1.80) and thyroid cancers (SIR = 1.61, 95% CI: 1.34, 1.88), and decreased risks were observed for buccal cavity/pharynx (SIR = 0.73, 95% CI: 0.55, 0.90), rectum (SIR = 0.62, 95% CI: 0.48, 0.76), and lung (SIR = 0.77, 95% CI: 0.70, 0.85) cancers.CONCLUSION: The elevated risk for breast cancer may be related to occupational radiation exposure. The observed melanoma and thryoid cancer excesses may reflect, at least in part, increased screening among medical workers with easy access to health care. [Copyright &y& Elsevier]