Radiation dose rates now and in the future for residents neighboring restricted areas of the Fukushima Daiichi Nuclear Power Plant.

Radiation dose rates were evaluated in three areas neighboring a restricted area within a 20- to 50-km radius of the Fukushima Daiichi Nuclear Power Plant in August-September 2012 and projected to 2022 and 2062. Study participants wore personal dosimeters measuring external dose equivalents, almost entirely from deposited radionuclides (groundshine). External dose rate equivalents owing to the accident averaged 1.03, 2.75, and 1.66 mSv/y in the village of Kawauchi, the Tamano area of Soma, and the Haramachi area of Minamisoma, respectively. Internal dose rates estimated from dietary intake of radiocesium averaged 0.0058, 0.019, and 0.0088 mSv/y in Kawauchi, Tamano, and Haramachi, respectively. Dose rates from inhalation of resuspended radiocesium were lower than 0.001 mSv/y. In 2012, the average annual doses from radiocesium were close to the average background radiation exposure (2 mSv/y) in Japan. Accounting only for the physical decay of radiocesium, mean annual dose rates in 2022 were estimated as 0.31, 0.87, and 0.53 mSv/y in Kawauchi, Tamano, and Haramachi, respectively. The simple and conservative estimates are comparable with variations in the background dose, and unlikely to exceed the ordinary permissible dose rate (1 mSv/y) for the majority of the Fukushima population. Health risk assessment indicates that post-2012 doses will increase lifetime solid cancer, leukemia, and breast cancer incidences by 1.06%, 0.03% and 0.28% respectively, in Tamano. This assessment was derived from short-term observation with uncertainties and did not evaluate the first-year dose and radioiodine exposure. Nevertheless, this estimate provides perspective on the long-term radiation exposure levels in the three regions.

Impaired Swallowing in Hospitalized Patients: An Observational Study in a Community Hospital in Japan (2012-2014).

BACKGROUND: Dysphagia is a serious health problem in aging populations. Older persons also experience high rates of chronic illness and hospitalization. Accurate identification of dysphagia at the time of hospital admission is important for providing supportive interventions for effective swallowing and preventing complications of dysphagia. OBJECTIVES: This study aimed to estimate the prevalence of potential impairment of swallowing function, the association between self-reported and observed swallowing difficulty, and factors associated with swallowing impairment in hospitalized patients. METHODS: Data from 11,963 patients who were admitted to a community hospital from July 2012 to June 2014 were used. Patients responded to a brief self-administered questionnaire (BSAQ) about swallowing difficulties and performed a modified water swallow test (MWST) using a standardized protocol. Sensitivity and specificity of the BSAQ were evaluated against swallowing impairment based on the MWST. Logistic regression analysis was performed to evaluate associations between background characteristics and impaired swallowing as evaluated by the screening tests. RESULTS: Median age of patients was 73 years (interquartile range, 63-81 years), and 5,780 (48.3%) were women. On the BSAQ, a total of 3,026 patients reported severe symptoms in any of 15 dysphagia-related questions (253 per 1,000 patients). The MWST showed that 593 patients were unable to successfully swallow 3 ml of cold water without choking or experiencing wet hoarseness two times within 30 seconds (50 per 1,000 patients). Each item score and the total score of the BSAQ were significantly associated with impaired swallowing as evaluated by the MWST. The sensitivity and specificity of the BSAQ for impaired swallowing as evaluated by the MWST were 72% and 66%, respectively. The prevalence of impaired swallowing as evaluated by both tests increased with age-especially in patients of ages ≥80 years. Age, male gender, and underlying diseases, including neurological and respiratory diseases, were associated with swallowing dysfunction detected by the MWST. DISCUSSION: Impaired swallowing function may frequently be present in older hospitalized patients. The clinical significance of the validated screening tests in nursing practice should be further studied.

Skipping breakfast adversely affects menstrual disorders in young college students.

In the present study we conducted a questionnaire survey to examine the relationship between dietary habits and menstrual disorders in young women. Subjects were recruited from 315 college students and were classified as: Group I, eating breakfast; Group II, skipping breakfast; Group III, not eating fast foods; Group IV, eating fast foods; Group V, not eating processed foods; and Group VI, eating processed foods. The intensity of dysmenorrhea was scored using three grades. All participants were further divided into groups based on having regular or irregular menstruation, having premenstrual symptoms or not, and self-perception of good or poor general health. General health was poor in Groups II and VI, and dysmenorrhea scores were high in Groups II, IV and VI. The incidence of irregular menses was also high in Group II. However, there was no apparent relation between premenstrual symptoms and dietary habits. These findings suggest that skipping breakfast adversely affects menstrual disorders in young college students.

Non-homologous end-joining for repairing I-SceI-induced DNA double strand breaks in human cells.

DNA double strand breaks (DSBs) are usually repaired through either non-homologous end-joining (NHEJ) or homologous recombination (HR). While HR is basically error-free repair, NHEJ is a mutagenic pathway that leads to deletion. NHEJ must be precisely regulated to maintain genomic integrity. To clarify the role of NHEJ, we investigated the genetic consequences of NHEJ repair of DSBs in human cells. Human lymphoblastoid cell lines TSCE5 and TSCE105 have, respectively, single and double I-SceI endonuclease sites in the endogenous thymidine kinase gene (TK) located on chromosome 17q. I-SceI expression generated DSBs at the TK gene. We used the novel transfection system (Amaxa Nucleofector) to introduce an I-SceI expression vector into the cells and randomly isolated clones. We found mutations involved in the DSBs in the TK gene in 3% of TSCE5 cells and 30% of TSCE105 cell clones. Most of the mutations in TSCE5 were small (1-30bp) deletions with a 0-4bp microhomology at the junction. The others consisted of large (>60) bp deletions, an insertion, and a rearrangement. Mutants resulting from interallelic HR also occurred, but infrequently. Most of the mutations in TSCE105, on the other hand, were deletions that encompassed the two I-SceI sites generated by NHEJ at DSBs. The sequence joint was similar to that found in TSCE5 mutants. Interestingly, some mutants formed a new I-SceI site by perfectly joining the two original I-SceI sites without deletion of the broken-ends. These results support the idea that NHEJ for repairing I-SceI-induced DSBs mainly results in small or no deletions. Thus, NHEJ must help maintain genomic integrity in mammalian cells by repairing DSBs as well as by preventing many deleterious alterations.

Potassium bromate treatment predominantly causes large deletions, but not GC>TA transversion in human cells.

Potassium bromate (KBrO(3)) is strongly carcinogenic in rodents and mutagenic in bacteria and mammalian cells in vitro. The proposed genotoxic mechanism for KBrO(3) is oxidative DNA damage. KBrO(3) can generate high yields of 8-hydroxydeoxyguanosine (8OHdG) DNA adducts, which cause GC>TA transversions in cell-free systems. In this study, we investigated the in vitro genotoxicity of KBrO(3) in human lymphoblastoid TK6 cells using the comet (COM) assay, the micronucleus (MN) test, and the thymidine kinase (TK) gene mutation assay. After a 4h treatment, the alkaline and neutral COM assay demonstrated that KBrO(3) directly yielded DNA damages including DNA double strand breaks (DSBs). KBrO(3) also induced MN and TK mutations concentration-dependently. At the highest concentration (5mM), KBrO(3) induced MN and TK mutation frequencies that were over 30 times the background level. Molecular analysis revealed that 90% of the induced mutations were large deletions that involved loss of heterozygosity (LOH) at the TK locus. Ionizing-irradiation exhibited similar mutational spectrum in our system. These results indicate that the major genotoxicity of KBrO(3) may be due to DSBs that lead to large deletions rather than to 8OHdG adducts that lead to GC>TA transversions, as is commonly believed. To better understand the genotoxic mechanism of KBrO(3), we analyzed gene expression profiles of TK6 cells using Affymetrix Genechip. Some genes involved in stress, apoptosis, and DNA repair were up-regulated by the treatment of KBrO(3). However, we could not observe the similarity of gene expression profile in the treatment of KBrO(3) to ionizing-irradiation as well as oxidative damage inducers.

Genotoxicity of acrylamide and glycidamide in human lymphoblastoid TK6 cells.

The recent finding that acrylamide (AA), a potent carcinogen, is formed in foods during cooking raises human health concerns. In the present study, we investigated the genotoxicity of AA and its metabolite glycidamide (GA) in human lymphoblastoid TK6 cells examining three endpoints: DNA damage (comet assay), clastogenesis (micronucleus test) and gene mutation (thymidine kinase (TK) assay). In a 4 h treatment without metabolic activation, AA was mildly genotoxic in the micronucleus and TK assays at high concentrations (> 10 mM), whereas GA was significantly and concentration-dependently genotoxic at all endpoints at > or = 0.5 mM. Molecular analysis of the TK mutants revealed that AA predominantly induced loss of heterozygosity (LOH) mutation like spontaneous one while GA-induced primarily point mutations. These results indicate that the genotoxic characteristics of AA and GA were distinctly different: AA was clastogenic and GA was mutagenic. The cytotoxicity and genotoxicity of AA were not enhanced by metabolic activation (rat liver S9), implying that the rat liver S9 did not activate AA. We discuss the in vitro and in vivo genotoxicity of AA and GA.

Biological Monitoring of Human Exposure to Neonicotinoids Using Urine Samples, and Neonicotinoid Excretion Kinetics.

BACKGROUND: Neonicotinoids, which are novel pesticides, have entered into usage around the world because they are selectively toxic to arthropods and relatively non-toxic to vertebrates. It has been suggested that several neonicotinoids cause neurodevelopmental toxicity in mammals. The aim was to establish the relationship between oral intake and urinary excretion of neonicotinoids by humans to facilitate biological monitoring, and to estimate dietary neonicotinoid intakes by Japanese adults. METHODOLOGY/PRINCIPAL FINDINGS: Deuterium-labeled neonicotinoid (acetamiprid, clothianidin, dinotefuran, and imidacloprid) microdoses were orally ingested by nine healthy adults, and 24 h pooled urine samples were collected for 4 consecutive days after dosing. The excretion kinetics were modeled using one- and two-compartment models, then validated in a non-deuterium-labeled neonicotinoid microdose study involving 12 healthy adults. Increased urinary concentrations of labeled neonicotinoids were observed after dosing. Clothianidin was recovered unchanged within 3 days, and most dinotefuran was recovered unchanged within 1 day. Around 10% of the imidacloprid dose was excreted unchanged. Most of the acetamiprid was metabolized to desmethyl-acetamiprid. Spot urine samples from 373 Japanese adults were analyzed for neonicotinoids, and daily intakes were estimated. The estimated average daily intake of these neonicotinoids was 0.53-3.66 µg/day. The highest intake of any of the neonicotinoids in the study population was 64.5 µg/day for dinotefuran, and this was <1% of the acceptable daily intake.

[Clinical analysis of 10 cases of chest wall tuberculosis].

AIM/METHODS: A series of 10 cases of chest wall tuberculosis (man/woman=7/3, average age 62 +/- 17 years old) during past seven years were reviewed. RESULTS: Acid-fast bacillus was detected from an abscess in 60% by smear, 30% by culture, and 75% by polymerase chain reaction (PCR). It was characteristic that enhanced CT of abscess revealed a low density mass with peripheral enhancement, 'rim enhancement findings', in all cases. CT also showed ipsilateral pleural thickening in all cases, suggesting lymphogenous pathogenesis of chest wall lesions from tuberculous pleurisy. As for the treatment, antituberculosis chemotherapies were done in all cases. In addition, open drainage was done in 8 cases and curettage of abscess was performed in 5 cases. None of these ten cases had relapsed during the follow-up periods for 12 to 77 months. CONCLUSIONS: Chest wall tuberculosis is still important as a disorder of a chest wall mass requiring differential diagnosis. Contrasting CT is thought to be useful for the diagnosis. It should be emphasized that 50% of the cases had good outcome without curettage.

Deletion, rearrangement, and gene conversion; genetic consequences of chromosomal double-strand breaks in human cells.

Chromosomal double-strand breaks (DSBs) in mammalian cells are usually repaired through either of two pathways: end-joining (EJ) or homologous recombination (HR). To clarify the relative contribution of each pathway and the ensuing genetic changes, we developed a system to trace the fate of DSBs that occur in an endogenous single-copy human gene. Lymphoblastoid cell lines TSCE5 and TSCER2 are heterozygous (+/-) or compound heterozygous (-/-), respectively, for the thymidine kinase gene (TK), and we introduced an I-SceI endonuclease site into the gene. EJ for a DSB at the I-SceI site results in TK-deficient mutants in TSCE5 cells, while HR between the alleles produces TK-proficient revertants in TSCER2 cells. We found that almost all DSBs were repaired by EJ and that HR rarely contributes to the repair in this system. EJ contributed to the repair of DSBs 270 times more frequently than HR. Molecular analysis of the TK gene showed that EJ mainly causes small deletions limited to the TK gene. Seventy percent of the small deletion mutants analyzed showed 100- to 4,000-bp deletions with a 0- to 6-bp homology at the joint. Another 30%, however, were accompanied by complicated DNA rearrangements, presumably the result of sister-chromatid fusion. HR, on the other hand, always resulted in non-crossing-over gene conversion without any loss of genetic information. Thus, although HR is important to the maintenance of genomic stability in DNA containing DSBs, almost all chromosomal DSBs in human cells are repaired by EJ.

Genotoxicity of microcystin-LR in human lymphoblastoid TK6 cells.

Toxic cyanobacteria (blue-green algae) water blooms have become a serious problem in several industrialized areas of the world. Microcystin-LR (MCLR) is a cyclic heptapeptidic toxin produced by the cyanobacteria. In the present study, we used human lymphoblastoid cell line TK6 to investigate the in vitro genotoxicity of MCLR. In a standard 4h treatment, MCLR did not induce a significant cytotoxic response at <80 microg/ml. In a prolonged 24h treatment, in contrast, it induced cytotoxic as well as mutagenic responses concentration-dependently starting at 20 microg/ml. At the maximum concentration (80 microg/ml), the micronucleus frequency and the mutation frequency at the heterozygous thymidine kinase (TK) locus were approximately five-times the control values. Molecular analysis of the TK mutants revealed that MCLR specifically induced loss of heterozygosity at the TK locus, but not point mutations or other small structural changes. These results indicate that MCLR had a clastogenic effect. We discuss the mechanisms of MCLR genotoxicity and the possibility of its being a hepatocarcinogen.

Chromosomal instability in B-lymphoblasotoid cell lines from Werner and Bloom syndrome patients.

Werner's syndrome (WS) and Bloom's syndrome (BS) are rare autosomal genetic diseases that predispose to cancer and are associated with genomic instability. To characterize the genomic instability of WS and BS, we analyzed and compared the cytogenetics of B-lymphoblastoid cell lines (LCLs) from WS and BS patients and healthy donors. Although, similar spontaneous frequencies of micronuclei (MN) and sister chromatid exchanges (SCE) were observed in LCLs from WS patients and healthy donors, they were much higher in BS-LCLs. We also examined the cells' cytotoxic and cytogenetic formation (MN) response to camptothecin (CAM), etoposide (ETO), 4-nitroquinoline 1-oxide (4NQO), and mitomycin C (MMC). Compared to healthy donor LCLs, BS-LCLs but not WS-LCLs tended to be resistant to cytotoxicity and sensitive to MN induction by 4NQO and MMC. Spectrum karyotyping analysis revealed that most WS- and BS-LCLs generated "variegated translocation mosaicism" at high frequencies during cell culture. These findings support the idea that the basis of genomic instability in WS is different from that in BS.

[Problems about the management of active pulmonary tuberculosis patients undergoing haemodialysis--our experiences and nation-wide questionnaire survey].

UNLABELLED: End-stage renal failure patients on chronic dialysis are high risk groups of tuberculosis due to attenuated cellular immunity. Patients receiving haemodialysis stay prolonged time inside the health-care facilities, thereby increased risk of tuberculosis transmission if a patient has active disease. So management of active pulmonary tuberculosis undergoing haemodialysis is important, however, the number of hospitals which are capable of taking care of such patients is estimated to be few in Japan. METHODS: From August 1994 through July 2002, 1059 active pulmonary tuberculosis patients (mean age; 57 +/- 19, male/female = 773/286) were admitted to Nishi-Kobe Medical Center, a 500-bed teaching hospital. Out of them, patients undergoing haemodialysis were retrospectively studied to describe the clinical characteristics of such cases. Then we conducted a questionnaire survey regarding the management of active pulmonary tuberculosis patients undergoing haemodialysis for 86 self-governing bodies in Japan. RESULTS: (1) Clinical characteristics of active pulmonary tuberculosis undergoing haemodialysis. We encountered 14 cases (mean age; 65 +/- 11, male/female = 7/7) of pulmonary tuberculosis undergoing haemodialysis during 8 years. In addition to pulmonary involvement, 3 pleural, one knee joint and one lymph node involvement was detected. Primary renal disease included diabetic nephropathy (n = 3), chronic glomerulonephritis (n = 3), congenital anomaly (n = 1), and unknown (n = 7). Nine cases were referred to our hospital from health-care facilities located out of city or prefecture. In five cases it took more than three months from the onset or detection of abnormal chest X-ray findings to the admission to our hospital. Five cases developed pulmonary tuberculosis within the first year after the initiation of dialysis. None of the patients had a past history of tuberculosis. Cavitary lesion on chest X-ray was observed in only one case. Triple antituberculosis therapy was used in 9 patients, and 4 antituberculosis drugs were used in 5 patients. Antituberculosis therapy was successfully done in all cases except two patients who died of apoplexy and cerebral infarction. (2) The nation-wide questionnaire survey. Of the 86 self-governing bodies we mailed, 66 self-governing bodies replied. Of them, 31% reported that they have experienced difficulties in the management of active pulmonary tuberculosis patients undergoing haemodialysis, and 25% reported the lack of health-care facilities to take care of such cases in their territory. They have referred such patients to hospitals located in the nearby prefectures or they have recommended antituberculosis therapy visiting a local haemodialysis facility. CONCLUSION: There are sometimes difficulties to manage active pulmonary tuberculosis patients undergoing haemodialysis in Japan. Health-care facilities to take care of such patients should be arranged and the formation of the network is necessarily.

[A case of Japanese summer-type hypersensitivity pneumonitis: monitoring with serum KL-6 and examination of the phenotype of HLA].

A 55-year-old woman was admitted with a cough and fever in August. A diagnosis of Japanese summer-type hypersensitivity pneumonitis was made on the basis of radiological, serological and pathological findings, in addition to positive returning home provocation. Serum KL-6 was monitored during the clinical course. Although KL-6 fluctuated slowly in comparison with the clinical symptoms and HRCT findings, it was considered useful for confirming the effects of treatment. Serum anti-Trichosporon antibody and the phenotype of HLA were studied in both the patient and her asymptomatic roommate, with whom she had no blood relationship. Though both were sensitized immunologically, HLA-DQ 3, which was reported to be associated with Japanese summer-type hypersensitivity pneumonitis, was detected in the patient but not in her roommate. It was suggested that HLA plays a role in the development of this disease.

Dependence of DNA double strand break repair pathways on cell cycle phase in human lymphoblastoid cells.

DNA double-strand breaks (DSBs) are usually repaired by nonhomologous end-joining (NHEJ) or homologous recombination (HR). NHEJ is thought to be the predominant pathway operating in mammalian cells functioning in all phases of the cell cycle, while HR works in the late-S and G2 phases. However, relative contribution, competition, and dependence on cell cycle phases are not fully understood. We previously developed a system to trace the fate of DSBs in the human genome by introducing the homing endonuclease I-SceI site into the thymidine kinase (TK) gene of human lymphoblastoid TK6 cells. Here, we use this system to investigate the relative contribution of HR and NHEJ for repairing I-SceI-induced DSBs under various conditions. We used a novel transfection system, Amaxa nucleofector, which directly introduces the I-SceI expression vector into cell nuclei. Approximately 65% of transfected cells expressed the I-SceI enzyme and over 50% of the cells produced a single DSB in the genome. The relative contribution of NHEJ and HR for repairing the DSB was approximately 100:1 and did not change with transfection efficiency. Cotransfection with KU80-siRNA significantly diminished KU80 protein levels and decreased NHEJ activity, but did not increase HR. We also investigated HR and NHEJ in synchronized cells. The HR frequency was 2-3 times higher in late-S/G2 phases than in G1, whereas NHEJ was unaffected. Even in late-S/G2 phases, NHEJ remained elevated relative to HR. Therefore, NHEJ is the major pathway for repairing endonuclease-induced DSBs in mammalian cells even in late-S/G2 phase, and does not compete with HR.

3-Dimensional microarray analysis of estrogen signal-related genes in breast cancer tissues.

BACKGROUND: Expression analysis of estrogen response genes (ERGs) may help to predict the effectiveness of endocrine therapies in breast cancer patients. We produced a custom-made, 3-dimensional microarray system (3DMS), using previously identified ERGs, and analyzed expression of ERGs on breast cancer tissues. MATERIALS AND METHODS: aRNA was synthesized from 27 breast cancer tumors. The aRNAs were applied to the infrastructure of a 3DMS with spotted cDNA probes to 36 ERGs. Data were analyzed by cluster analysis. RESULTS: All 27 specimens were classified clearly into one of two clusters based on whether the ERGs were up or down regulated. These groups correlated with high expression of ER (P<0.05) and Her2 (P<0.05). In some cases, ERG expressions were low even though the tumor was ER positive. CONCLUSION: 3DMS may be useful for accurately predicting prognosis and whether endocrine therapies targeting the ER would be effective in an individual breast cancer patient.

A pilot study of aerosolized N-acetylcysteine for idiopathic pulmonary fibrosis.

OBJECTIVE: Idiopathic pulmonary fibrosis poses a significant therapeutic challenge because of its progressive course. Since oxidative stress plays an important role in the pathogenesis of idiopathic pulmonary fibrosis, an open, randomized trial of long-term inhalation therapy with the antioxidant, N-acetylcysteine was conducted. METHODOLOGY: A total of 30 patients with idiopathic pulmonary fibrosis were randomly assigned to one of the following inhalation therapies: N-acetylcysteine (352 mg per day) or bromhexine hydrochloride (4 mg per day) as the control. Efficacy was assessed by analysing changes occurring from baseline to 12 months in pulmonary function, the 6-min walking test, high-resolution CT, health-related quality of life, and serum KL-6-values. RESULTS: Four patients (n=2 in each group) died within 12 months due to progression of idiopathic pulmonary fibrosis. A total of 22 patients (control, n=12; N-acetylcysteine, n=10) completed the study. At 12 months there were significant differences between the N-acetylcysteine and control groups in terms of mean changes in lowest SaO(2) during the 6-min walking test (-0.3+/- 2.1% vs -6.8+/-1.8%, P<0.05), serum KL--6 (-482+/-220 U/mL vs 176+/-204 U/mL, P<0.05), and the ground-glass score on high-resolution CT (-1.3+/-1.6 vs 6.7+/-1.5, P<0.01). No significant differences were observed in pulmonary function, 6-min walking distance or quality of life. CONCLUSIONS: These data suggest that although long-term aerosolized N-acetylcysteine administration did not influence pulmonary function or quality of life, it may delay disease progression as evidenced by exercise desaturation, high-resolution CT, and serum KL-6.