Toshihide Tsuda

Risk Factors for Local Progression After Percutaneous Radiofrequency Ablation of Lung Tumors Evaluation Based on a Preliminary Review of 342 Tumors

The purpose of the study was to retrospectively evaluate the risk factors for local progression after percutaneous radiofrequency (RF) ablation of lung tumors.

Effects of a one-hour educational program on medical students' attitudes to mental illness

Abstract A new 1‐h educational program was developed to change attitudes towards mental illness, and was conducted on 95 first‐year medical students in order to investigate its effects on their attitudes towards mental illness, using a pre‐ and postquestionnaire study design. A similar study without the program was conducted on 94 first‐year medical students as controls. After the program, more students replied that they would accept former patients on relatively close social distance items. Favorable attitudinal changes were observed in terms of ‘psychiatric services’, ‘human rights of the mentally ill’, ‘patients’ independence in social life’, and ‘cause and characteristics of mental illness’. In contrast, no significant change was observed in the control group. These results suggest that attitudes towards mental illness could be changed favorably by this program.

Monitoring of mercury pollution in Tanzania: relation between head hair mercury and health

Through 1996 into 1997, a spot investigation on mercury contamination was conducted three times in Tanzania, especially around the Lake Victoria. A total of 150 goldminers, 103 fishermen and their families, and 19 residents of Mwanza City volunteered for the current study. A high total mercury level of 48.3 ppm (near to 50 ppm, a critical level of Minamata disease) and over in the head hair was observed in six goldminers (highest value, 953 ppm), four fishermen and their families (highest value, 416 ppm), and four Mwanza people (highest value, 474 ppm). With the exception of these 14 subjects, however, each mean total mercury level was well within the normal range (below 10 ppm). Out of the goldminers examined, 14 cases were diagnosed as a mild form of inorganic-mercury poisoning according to their clinical symptoms (such as polyneuropathy mercurialis, neuroasthemia, or tremor mercurialis) and the low ratio of methylmercury to total mercury, whereas neither inorganic-mercury poisoning nor methylmercury poisoning (Minamata disease) was noted in the fishermen and their families or in the Mwanza people. In addition, some subjects who showed a high total mercury level made habitual use of toilet soap containing much mercury. The findings obtained suggest that the mercury pollution in Tanzania is not very serious, however, it should be observed continuously.

Dose effect of smoking on aberrant methylation in non-small cell lung cancers.

Shinichi TOYOOKA, Makoto SUZUKI, Toshihide TSUDA, Kiyomi O. TOYOOKA, Riichiroh MARUYAMA, Kazunori TSUKUDA, Yasuro FUKUYAMA, Toshihiko IIZASA, Takehiko FUJISAWA, Nobuyoshi SHIMIZU, John D. MINNA and Adi F. GAZDAR* Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, Dallas, TX, USA Department of Cancer and Thoracic Surgery, Okayama University Medical School, Okayama, Japan Department of Hygiene and Preventive Medicine, Okayama University Medical School, Okayama, Japan Department of Surgery 2, Kyushu University Faculty of Medicine, Fukuoka, Japan Department of Thoracic Surgery, Chiba University Medical School, Chiba, Japan Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, USA Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA

Methylmercury level in umbilical cords from patients with congenital Minamata disease

A total of 151 umbilical cords during the period from 1950 to 1969 were collected from the residents of the Minamata area (including 25 patients with congenital Minamata disease) for methylmercury (MeHg) analysis. When the MeHg discharge from the Chisso Companys Minamata factory into the Minamata Bay is compared with the incidence of congenital Minamata disease, the abrupt increase of the former in 1952 [Nishimura H. Chem. Today 1998;323:60-66] was found to precede that of the latter by approximately 2 years, thereby indicating that MeHg is the cause of the disaster. This was confirmed by the elevated levels of MeHg in the umbilical cords from residents of the Minamata area [from 0.35 +/- 0.30 (S.D.) ppm in 1952 to 0.96 +/- 0.75 ppm in 1955], the MeHg levels (1.60 +/- 1.00 ppm) in the cords from patients with congenital Minamata disease showing the highest values [P < 0.01 vs. acquired Minamata disease (0.72 +/- 0.65 ppm), mental retardation (0.74 +/- 0.64 ppm), other diseases (0.22 +/- 0.15 ppm), and no symptoms (0.28 +/- 0.20 ppm), respectively]. Thus, in order to fill a gap, which extends over a long period of time, in studies on environmental Hg pollution, umbilical cord samples were considered to be a useful tool.

Application of land use regression to regulatory air quality data in Japan

A land use regression (LUR) model has been used successfully for predicting traffic-related pollutants, although its application has been limited to Europe and North America. Therefore, we modeled traffic-related pollutants by LUR then examined whether LUR models could be constructed using a regulatory monitoring network in Shizuoka, Japan. We used the annual-mean nitrogen dioxide (NO2) and suspended particulate matter (SPM) concentrations between April 2000 and March 2006 in the study area. SPM accounts for particulate matter with an aerodynamic diameter less than 8 microm (PM(8)). Geographic variables that are considered to predict traffic-related pollutants were classified into four groups: road type, traffic intensity, land use, and physical component. Using geographical variables, we then constructed a model to predict the monitored levels of NO2 and SPM. The mean concentrations of NO2 and SPM were 35.75 microg/m(3) (standard deviation of 11.28) and 28.67 microg/m(3) (standard deviation of 4.73), respectively. The final regression model for the NO2 concentration included five independent variables. R(2) for the NO2 model was 0.54. On the other hand, the regression model for the SPM concentration included only one independent variable. R(2) for the SPM model was quite low (R(2) = 0.11). The present study showed that even if we used regulatory monitoring air quality data, we could estimate NO2 moderately well. This result could encourage the wide use of LUR models in Asian countries.

Thyroid Cancer Detection by Ultrasound Among Residents Ages 18 Years and Younger in Fukushima, Japan: 2011 to 2014

Background: After the Great East Japan Earthquake and Tsunami in March 2011, radioactive elements were released from the Fukushima Daiichi Nuclear Power Plant. Based on prior knowledge, concern emerged about whether an increased incidence of thyroid cancer among exposed residents would occur as a result. Methods: After the release, Fukushima Prefecture performed ultrasound thyroid screening on all residents ages ⩽18 years. The first round of screening included 298,577 examinees, and a second round began in April 2014. We analyzed the prefecture results from the first and second round up to December 31, 2014, in comparison with the Japanese annual incidence and the incidence within a reference area in Fukushima Prefecture. Results: The highest incidence rate ratio, using a latency period of 4 years, was observed in the central middle district of the prefecture compared with the Japanese annual incidence (incidence rate ratio = 50; 95% confidence interval [CI] = 25, 90). The prevalence of thyroid cancer was 605 per million examinees (95% CI = 302, 1,082) and the prevalence odds ratio compared with the reference district in Fukushima Prefecture was 2.6 (95% CI = 0.99, 7.0). In the second screening round, even under the assumption that the rest of examinees were disease free, an incidence rate ratio of 12 has already been observed (95% CI = 5.1, 23). Conclusions: An excess of thyroid cancer has been detected by ultrasound among children and adolescents in Fukushima Prefecture within 4 years of the release, and is unlikely to be explained by a screening surge.

Long-term exposure to traffic-related air pollution and the risk of death from hemorrhagic stroke and lung cancer in Shizuoka, Japan

A number of studies have linked exposure to long-term outdoor air pollution with cardiopulmonary disease; however, the evidence for stroke is limited. Furthermore, evidence with the risk for lung cancer (LC) is still inconsistent. We, therefore, evaluated the association between long-term exposure to traffic-related air pollution and cause-specific mortality. Individual data were extracted from participants of an ongoing cohort study in Shizuoka, Japan. A total of 14,001 elderly residents completed questionnaires and were followed from December 1999 to January 2009. Annual individual nitrogen dioxide (NO(2)) exposure data, as an index for traffic-related exposure, were modeled using a Land Use Regression model and assigned to the participants. We then estimated the adjusted hazard ratios (HRs) and their confidence intervals (CIs) associated with a 10 μg/m(3) elevation in NO(2) for all-cause or cause-specific mortality using time-varying Cox proportional hazards models. We found positive associations of NO(2) levels with all-cause (HR=1.12, 95% CI: 1.07-1.18), cardiopulmonary disease (HR=1.22, 95% CI: 1.15-1.30), and LC mortality (HR=1.20, 95% CI: 1.03-1.40). Among cardiopulmonary disease mortality, not only the risk for ischemic heart disease (HR=1.27, 95% CI: 1.11-1.47) but also the risks for stroke were elevated: intracerebral hemorrhage (HR=1.28, 95% CI: 1.05-1.57) and ischemic stroke (HR=1.20, 95% CI: 1.04-1.39). The present study supports the existing evidence that long-term exposure to traffic-related air pollution increases the risk of cardiopulmonary as well as LC mortality, and provides additional evidence for adverse effects on intracerebral hemorrhage as well as ischemic stroke.

Long-term exposure to methylmercury and psychiatric symptoms in residents of Minamata, Japan

INTRODUCTION It is well-known that prenatal or postnatal exposure to methylmercury can produce neurological signs in adults and children, exemplified by a case of large-scale poisoning in Minamata, Japan, in the 1950s. However, evidence regarding whether pre- or postnatal exposure to methylmercury causes psychiatric symptoms (e.g., impairment of intelligence and mood and behavioral dysfunction) is still limited-excluding cases of fetal Minamata disease patients. METHODS We evaluated the effects of pre- or postnatal exposure to methylmercury on psychiatric symptoms using data derived from a 1971 population-based survey in Minamata and neighboring communities. We adopted residential areas as an exposure indicator and psychiatric symptoms as the outcome. Then, we estimated the adjusted prevalence odds ratio (POR) and confidence interval (CI) of psychiatric symptoms in relation to residential area. RESULTS There were 904 participants in Minamata (high exposure area), 1700 in Goshonoura (middle exposure area), and 913 in Ariake (low exposure area). Compared to the Ariake area, participants in the Minamata area manifested psychiatric symptoms more frequently: PORs for impairment of intelligence and mood and behavioral dysfunction were 5.2 (95% CI: 3.7-7.3) and 4.4 (95% CI: 2.9-6.7), respectively. Furthermore, participants with psychiatric symptoms in the Minamata area more frequently had neurological signs. Peaks in prevalence of psychiatric symptoms occurred around age 20 and in older age adults in the area. These findings did not change when we excluded those who had been officially certified as Minamata disease patients by that time. CONCLUSIONS The present study suggests a relationship between pre- or postnatal exposure to methylmercury and psychiatric symptoms among the general population in Minamata even after excluding officially certified patients.

Can Stress Management at the Workplace Prevent Depression? A Randomized Controlled Trial

Background: Stress, mental health and depression at the workplace have emerged as common and significant problems. The effectiveness of a stress-management program at the workplace was investigated. Methods: The effectiveness of a stress-management program was examined in workers at a highly stressful workplace using a randomized controlled trial. The 58 workers in the office were randomly assigned into a stress-management group (n = 28) and a control group (n = 30). The stress-management program included lectures on the perception of stress, measures to cope with it, stress-management recording sheets, and e-mail counseling. This program was based on the cognitive behavioral approach. The stress-management program was carried out for 3 months, and perceived work-related stress and psychological symptoms were evaluated using: General Health Questionnaire (GHQ)-30, Center for Epidemiologic Study for Depression (CES-D), the Questionnaire of Work-Related Stress and the Effort-Reward Imbalance Questionnaire. Twenty-one out of the 28 in the stress-management group and all in the control group were successfully followed up. Results: In the stress-management group, a significant improvement in the depressive symptoms was observed, compared with the control group in CES-D (p = 0.003 by two-tailed paired t-test, and p = 0.042 by repeated measure analysis of variance). In the multiple regression analysis, the effect of stress management on depressive symptoms at follow-up was significant (p = 0.041), controlling for potential confounding factors. However, the alleviation of perceived occupational stress was limited. Conclusions: A stress-management program based on the cognitive behavioral approach at the workplace may have potential for the prevention of depression.