Tomoaki Imamura

Nara Medical University, Nara-shi, Nara, Japan

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Publications (92)166.02 Total impact

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    ABSTRACT: Cedar pollinosis in Japan affects nearly 25 % of Japanese citizens. To develop a treatment for cedar pollinosis, it is necessary to understand the relationship between the time of its occurrence and the amount of airborne cedar pollen. In the spring of 2009, we conducted daily Internet-based epidemiologic surveys, which included 1453 individuals. We examined the relationship between initial date of onset of pollinosis symptoms and daily amount of airborne cedar pollen to which subjects were exposed. Approximately 35.2 % of the subjects experienced the onset of pollinosis during a one-week interval in which the middle day coincided with the peak pollen count. The odds ratio for this one-week time interval was 4.03 (95 % confidence interval: 3.34-4.86). The predicted date of the cedar pollen peak can be used to determine the appropriate date for initiation of self-medication with anti-allergy drugs and thus avoid development of sustained and severe pollinosis.
    International Journal of Environmental Health Research 04/2014; · 1.20 Impact Factor
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    ABSTRACT: Objectives With increasing global interest in intentional food contamination, expert meetings have been held by the G8, while the U.S. government has proposed policies for preventing food terrorism and intentional contamination. However, Japan has no food defense policy, and some food companies are concerned about an impending terrorism and contamination crisis.Methods We developed a Food Defense Checklist for Food Producers and Processors and published the details on the website. We also developed tentative Food Defense Guidelines for Food Producers and Processors on the basis of the checklist. In this study, we tested the usability of the guidelines through a hearing survey regarding food plants. We also compared the checklist with the implementation manual for the approval system of Comprehensive Sanitation Management and Production Process (the Japanese equivalent of the HACCP).Results We organized the comments gleaned from the hearing survey and provided a detailed explanation of the guidelines. As the HACCP has been adopted by Japanese food companies, we included both precautionary measures and the HACCP perspective in the explanation regarding the rapid dissemination of information.Conclusion The guidelines are useful for Japanese food companies, and it is important to disseminate knowledge on this topic and implement food defense measures.
    [Nippon kōshū eisei zasshi] Japanese journal of public health 01/2014; 61(2):100-9.
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    ABSTRACT: Patients with a history of ischemic stroke are known to develop new ischemic stroke. While asymptomatic, the presence and progression of silent brain infarcts and white matter lesions on magnetic resonance imaging are associated with an increased risk of future strokes. Both angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers are recommended for the primary and secondary prevention of stroke, but there are no direct comparisons of angiotensin-converting enzyme inhibitors versus angiotensin II receptor blockers regarding their cerebroprotective effects, including their effect on asymptomatic cerebral lesions detected by magnetic resonance imaging. Elderly (65 years or older) patients with essential hypertension who underwent cerebral magnetic resonance imaging and were found to have any cerebral ischemic lesions, such as cerebral infarction, silent brain infarct, or white matter lesion, were enrolled in this CEREBRAL study. Patients who agreed to participate were enrolled in the randomized controlled trial portion. Patients who did not agree to participate in the randomized controlled trial were enrolled in the cohort study portion. After two-years of angiotensin-converting enzyme inhibitor or angiotensin II receptor blockers treatment, follow-up magnetic resonance imaging examination will be performed. The primary end-point is the composite of (1) occurrence of a fatal or nonfatal cerebrovascular event or (2) progression of cerebrovascular lesions as evaluated by magnetic resonance imaging, including white matter lesions or silent brain infarcts. After enrollment, cognitive function was evaluated, if possible, using the Mini-Mental State Examination. Our study will clarify whether angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers are more effective for preventing primary and recurrence of ischemic stroke, including the progression of asymptomatic cerebral lesions on magnetic resonance imaging, in elderly hypertensive patients.
    International Journal of Stroke 07/2013; · 2.75 Impact Factor
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    ABSTRACT: BACKGROUND: In 1968, many people developed dioxin poisoning (Yusho) in Japan. Ingestion of 2,3,4,7,8-pentachlorodibenzofuran (2,3,4,7,8-PeCDF) was considered to be the cause of this poisoning. Although some patients had high concentrations of 2,3,4,7,8-PeCDF in their blood, individuals' half-lives of 2,3,4,7,8-PeCDF were long. OBJECTIVES: To evaluate the relationship between clinical and laboratory parameters and the individual half-life of 2,3,4,7,8-PeCDF in blood. METHODS: Clinical and laboratory data were collected during annual check-ups from 2001 to 2008. We enrolled 71 patients, who were measured more than 3 times, and who had 2,3,4,7,8-PeCDF concentrations in blood >50pgg(-1) lipid. The half-life of 2,3,4,7,8-PeCDF for each patient was estimated using linear regression. Moreover, relationships between clinical and laboratory parameters and individual half-life were investigated by linear regression. RESULTS: A shortened individual half-life for 2,3,4,7,8-PeCDF was significantly correlated with an increased red blood cell count, increased viscous secretions from the meibomian glands, existing black comedones, and severe cedar pollen allergy. CONCLUSIONS: Symptoms that accelerate excretion of lipids from the body, such as viscous secretions from the meibomian glands, may lead to a shorter half-life of 2,3,4,7,8-PeCDF. Red blood cells are related to the half-life of 2,3,4,7,8-PeCDF. However, further studies are required to investigate the excretory mechanism of 2,3,4,7,8-PeCDF.
    Chemosphere 05/2013; · 3.14 Impact Factor
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    ABSTRACT: The relationships among dioxin isomers are not well understood. This study aimed to clarify the relationships among isomers using two methods. First, the relationships between isomers and symptoms were analyzed by analysis of variance. Second, concentrations and half-lives were determined for each isomer in each patient, and correlation coefficients for the concentrations and half-lives among isomers were calculated. Two isomers very similar to 2, 3, 4, 7, 8-pentachlorodibenzofuran (2, 3, 4, 7, 8-PeCDF) were correlated with symptoms of Yusho disease. The correlation coefficients among three isomers similar to 2, 3, 4, 7, 8-PeCDF were very high at 0.98, indicating that there may be a mechanism which maintains constant ratios among these isomers.
    Fukuoka igaku zasshi = Hukuoka acta medica 04/2013; 104(4):78-84.
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    ABSTRACT: OBJECTIVES:: There is a paucity of data examining nationwide population-based incidences and outcomes of pediatric out-of-hospital cardiac arrest. The objective of this study is to describe the detailed characteristics of pediatric out-of-hospital cardiac arrest by scholastic age category and to evaluate the impact of bystander cardiopulmonary resuscitation and public access-automated external defibrillators on the 1-month survival and favorable neurological status of pediatric out-of-hospital cardiac arrest patients. DESIGN:: A nationwide, population-based, observational study. SETTING:: Nationwide emergency medical system in Japan. PATIENTS:: Out-of-hospital cardiac arrest patients aged ≤ 18 yr. MEASUREMENTS AND MAIN RESULTS:: We identified 7,624 pediatric out-of-hospital cardiac arrest patients (≤ 18 yr old) from a nationwide population-based out-of-hospital cardiac arrest database in Japan from 2005 to 2008 and stratified them into five categories by scholastic age. The overall rates of 1-month survival and favorable neurological outcomes were 11.0% and 5.1%, respectively. Bystander cardiopulmonary resuscitation resulted in a significant improvement in both 1-month survival (odds ratio 2.81; 95% confidence interval 2.30-3.44) and favorable neurological outcomes (odds ratio 4.55; 95% confidence interval 3.35-6.18). Performing public access-automated external defibrillators had a significant effect on the 1-month survival rate (odds ratio 3.51; 95% confidence interval 1.81-6.81) and favorable neurological outcomes (odds ratio 5.13; 95% confidence interval 2.64-9.96). CONCLUSIONS:: This study demonstrated that bystander cardiopulmonary resuscitation and public access-automated external defibrillators had a significant impact on the outcomes of pediatric out-of-hospital cardiac arrest. The improved survival associated with bystander cardiopulmonary resuscitation and public access-automated external defibrillators are clinically important and are of major public health importance for school-aged out-of-hospital cardiac arrest patients.
    Pediatric Critical Care Medicine 01/2013; · 2.35 Impact Factor
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    ABSTRACT: The Great East Japan Earthquake occurred on March 11, 2011. Tokyo and Osaka, which are located 375 km and 750 km, respectively, from the epicenter, experienced tremors of 5.0 lower and 3.0 seismic intensity on the Japan Meteorological Agency scale. The Great East Japan Earthquake was the fourth largest earthquake in the world and was accompanied by a radioactive leak at a nuclear power plant and a tsunami. In the aftermath of a disaster, some affected individuals presented to mental health facilities with acute stress disorder (ASD) and/or post-traumatic stress disorder (PTSD). However, few studies have addressed mental stress problems other than ASD or PTSD among the general public immediately after a disaster. Further, the effects of such a disaster on residents living at considerable distances from the most severely affected area have not been examined. This study aimed to prospectively analyze the effect of a major earthquake on the prevalence of insomnia among residents of Tokyo and Osaka. A prospective online questionnaire study was conducted in Tokyo and Osaka from January 20 to April 30, 2011. An Internet-based questionnaire, intended to be completed daily for a period of 101 days, was used to collect the data. All of the study participants lived in Tokyo or Osaka and were Consumers' Co-operative Union (CO-OP) members who used an Internet-based food-ordering system. The presence or absence of insomnia was determined before and after the earthquake. These data were compared after stratification for the region and participants' age. Multivariate analyses were conducted using logistic regression and a generalized estimating equation. This study was conducted with the assistance of the Japanese CO-OP. The prevalence of insomnia among adults and minors in Tokyo and adults in Osaka increased significantly after the earthquake. No such increase was observed among minors in Osaka. The overall adjusted odds ratios for the risk of insomnia post-earthquake versus pre-earthquake were 1.998 (95% CI 1.571-2.542) for Tokyo, 1.558 (95% CI 1.106-2.196) for Osaka, and 1.842 (95% CI,1.514-2.242) for both areas combined. The prevalence of insomnia increased even in regions that were at a considerable distance from the epicenter. Both adults and minors in Tokyo, where the seismic intensity was greater, experienced stress after the earthquake. In Osaka, where the earthquake impact was milder, disturbing video images may have exacerbated insomnia among adults.
    Interactive journal of medical research. 01/2013; 2(1):e2.
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    ABSTRACT: INTRODUCTION: Conventional monophasic defibrillators for out-of-hospital cardiac arrest patients have been replaced with biphasic defibrillators. However, the advantage of biphasic over monophasic defibrillation for paediatric out-of-hospital cardiac arrest patients remains unknown. This study aimed to compare the survival outcomes of paediatric out-of-hospital cardiac arrest patients who underwent monophasic defibrillation with those who underwent biphasic defibrillation. METHODS: This prospective, nationwide, population-based observational study included paediatric out-of-hospital cardiac arrest patients from January 1, 2005 to December 31, 2009. The primary outcome measure was survival at 1 month with minimal neurological impairment. The secondary outcome measures were survival at 1 month and the return of spontaneous circulation before hospital arrival. Multivariable logistic regression analysis was performed to identify the independent association between defibrillator type (monophasic or biphasic) and outcomes. RESULTS: Among 5,628 paediatric out-of-hospital cardiac arrest patients (1-17 years old), 430 who received defibrillation shock by monophasic or biphasic defibrillator were analysed. The number of patients who received defibrillation shock by monophasic defibrillator was 127 (30%) and 303 (70%) received defibrillation shock by biphasic defibrillator. The survival rates at 1 month with minimal neurological impairment were 17.5% and 24.4%, the survival rates at 1 month were 32.3% and 35.6%, and the rates of return of spontaneous circulation before hospital arrival were 24.4% and 27.4% in the monophasic and biphasic defibrillator groups, respectively. Hierarchical logistic regression analyses using generalized estimation equations found no significant difference between the two groups in terms of 1-month survival with minimal neurological impairment (odds ratio [OR], 1.57; 95% confidence interval [CI], 0.87-2.83; p=0.14) and 1-month survival (OR, 1.38; 95%CI, 0.87-2.18; p=0.17). CONCLUSIONS: The present nationwide population-based observational study could not confirm an advantage of biphasic over monophasic defibrillators for paediatric OHCA patients.
    Critical care (London, England) 11/2012; 16(6):R219. · 4.72 Impact Factor
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    ABSTRACT: BACKGROUND: A growing elderly population along with advances in equipment and approaches for pre-hospital resuscitation necessitates up-to-date information when developing policies to improve elderly out-of-hospital cardiac arrest (OHCA) outcomes. We examined the effects of bystander type (family or non-family) intervention on 1-month outcomes of witnessed elderly OHCA patients. METHODS: Data from a total of 85,588 witnessed OHCA events in patients aged >=65 years, which occurred from 2005 to 2008, were obtained from a nationwide population-based database. Patients were stratified into three age categories (65--74, 75--84, >=85 years), and the effects of bystander type (family or non-family) on initial cardiac rhythm, rate of bystander cardiopulmonary resuscitation (CPR), and 1-month outcomes were assessed. RESULTS: The overall survival rate was 6.9% (65--74 years: 9.8%, 75--84 years: 6.9%, >=85 years: 4.6%). Initial VF/VT was recorded in 11.1% of cases with a family bystander and 12.9% of cases with a non-family bystander. The rate of bystander CPR was constant across the age categories in patients with a family bystander and increased with advancing age categories in patients with a non-family bystander. Patients having a non-family bystander were associated with significantly higher 1-month rates of survival (OR: 1.26; 95% CI: 1.19--1.33) and favorable neurological status (OR: 1.47; 95% CI: 1.34--1.60). CONCLUSIONS: Elderly patient OHCA events witnessed by a family bystander were associated with worse 1-month outcomes than those witnessed by a non-family bystander. Healthcare providers should consider targeting potential family bystanders for CPR education to increase the rate and quality of bystander CPR.
    International Journal of Emergency Medicine 11/2012; 5(1):41.
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    ABSTRACT: We have previously reported on both the os-teogenic potential of hydroxyapatite (HA) com-bined with bone marrow-derived mesenchymal stem cells (BMSCs) and a method involving os-teogenic matrix cell sheet transplantation of BMSCs. In the present study, we assessed the osteogenic potential of serially-passaged BMS-Cs, both in vitro and in vivo. We also assessed whether an additional cell-loading technique can regain the osteogenic potential of the constructs combined with serially-passaged BMSCs. The present study revealed that passage (P) 1 cells cultured in osteogenic-induced medium showed strong positive staining for alkaline phosphat-ase (ALP) and Alizarin Red S, whereas P3 cells showed faint staining for ALP, with no Alizarin Red S staining. Staining of P1, P2 and P3 cells were progressively weaker, indicating that the osteogenic potential of the serially-passaged rat BMSCs is lost after P3 in vitro. The in vivo study showed that little bone formation was observed in the HA constructs seeded with P3 cells, 4 weeks after subcutaneous implantation. How-ever, P3 cell/HA constructs which had incre-ased cell-loading showed abundant bone for-mation within the pores of the HA construct. ALP and osteocalcin mRNA expression in these constructs was significantly higher than that of constructs with regular cell-seeding. The pre-sent study indicates that the osteogenic poten-tial of the constructs with serially-passaged BMSCs is increased by additional cell-loading. This method can be applied to cases requiring hard tissue reconstruction, where BMSCs re-quire serial expansion of cells.
    10/2012; 2:133-140.
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    ABSTRACT: Background- The use and popularity of the biphasic waveform defibrillator as a replacement for the monophasic waveform defibrillator are increasing, but it is unclear whether this can improve the rate of survival among out-of-hospital cardiac arrest patients. This study aimed to verify the hypothesis that the outcome of out-of-hospital cardiac arrest patients who received defibrillation shock with the biphasic waveform defibrillator was better than that of patients who received defibrillation shock with the monophasic defibrillator. Methods and Results- This prospective, nationwide, population-based, observational study included 21 172 out-of-hospital cardiac arrest patients with initial ventricular fibrillation or pulseless ventricular tachycardia from January 1, 2005, through December 31, 2007. Defibrillation shock was performed by monophasic defibrillator on 8224 (39%) patients and by biphasic defibrillator on 12 948 (61%) patients. The rate of survival at 1 month with minimal neurological impairment was 11.6% (951/8192) in the monophasic defibrillator group and 12.8% (1653/12 928) in the biphasic defibrillator group. Hierarchical logistic regression analysis using a generalized estimation equation showed no significant difference between the biphasic and monophasic groups in 1-month survival with minimal neurological impairment (adjusted odds ratio, 1.07; 95% confidence interval, 0.91-1.26; P=0.42). Confirmatory propensity score analyses showed similar results. Conclusions- Although monophasic defibrillators are being replaced by biphasic defibrillators, our nationwide population-based observational study failed to demonstrate a statistically significant association between defibrillation waveform and 1-month survival rate with minimal neurological impairment.
    Circulation Cardiovascular Quality and Outcomes 09/2012; 5(5):689-96. · 5.66 Impact Factor
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    ABSTRACT: With increasing Internet coverage, the use of a web-based survey for epidemiological study is a possibility. We performed an investigation in Japan in winter 2008 using the web-based daily questionnaire for health (WDQH). The WDQH is a web-based questionnaire survey formulated to obtain information about the daily physical condition of the general public on a real-time basis, in order to study correlations between changes in physical health and changes in environmental factors. Respondents were asked whether they felt ill and had specific symptoms including fever. We analysed the environmental factors along with the health conditions obtained from the WDQH. Four factors were found to influence health: minimum temperature, hours of sunlight, median humidity and weekday or holiday. The WDQH allowed a daily health survey in the general population in real time via the Internet.
    International Journal of Environmental Health Research 09/2012; · 1.20 Impact Factor
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    ABSTRACT: BACKGROUND: The effect of prehospital use of supraglottic airway devices as an alternative to tracheal intubation on long-term outcomes of patients with out-of-hospital cardiac arrest is unclear. STUDY OBJECTIVES: We compared the neurological outcomes of patients who underwent supraglottic airway device insertion with those who underwent tracheal intubation. METHODS: We conducted a nationwide population-based observational study using a national database containing all out-of-hospital cardiac arrest cases in Japan over a 3-year period (2005-2007). The rates of neurologically favorable 1-month survival (primary outcome) and of 1-month survival and return of spontaneous circulation before hospital arrival (secondary outcomes) were examined. Multiple logistic regression analyses were performed to adjust for potential confounders. Advanced airway devices were used in 138,248 of 318,141 patients, including an endotracheal tube (ETT) in 16,054 patients (12%), a laryngeal mask airway (LMA) in 34,125 patients (25%), and an esophageal obturator airway (EOA) in 88,069 patients (63%). RESULTS: The overall rate of neurologically favorable 1-month survival was 1.03% (1426/137,880). The rates of neurologically favorable 1-month survival were 1.14% (183/16,028) in the ETT group, 0.98% (333/34,059) in the LMA group, and 1.04% (910/87,793) in the EOA group. Compared with the ETT group, the rates were significantly lower in the LMA group (adjusted odds ratio 0.77, 95% confidence interval [CI] 0.64-0.94) and EOA group (adjusted odds ratio 0.81, 95% CI 0.68-0.96). CONCLUSIONS: Prehospital use of supraglottic airway devices was associated with slightly, but significantly, poorer neurological outcomes compared with tracheal intubation, but neurological outcomes remained poor overall.
    Journal of Emergency Medicine 04/2012; · 1.33 Impact Factor
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    ABSTRACT: To investigate career trends for physician-scientists in Japan. The authors analyzed 1996-2008 biennial census survey data from Japan's national physician registry to examine trends over time in the numbers and proportion of physician-scientists by sex and years since registration. They also analyzed the transition of registered physicians into and out of the physician-scientist field across two sets of two consecutive surveys (1996-1998 and 2006-2008). The number of physician-scientists between 1996 and 2008 was stable, with a low of 4,893 and a high of 5,325. The number of younger physician-scientists (those registered 0-4 years at the time of the surveys) declined sharply, however, from 828 in 1996 to 253 in 2008. The number of female physician-scientists increased from 528 in 1996 to 746 in 2008. Across the two survey periods, about 30% of physician-scientists left the career path, but this attrition was offset by about the same number of new individuals entering the field. Although the total number of physician-scientists was relatively unchanged during the period studied, it is essential that educators and policy makers develop approaches to address underlying demographic changes to ensure an adequate age- and gender-balanced supply of physician-scientists in the future.
    Academic medicine: journal of the Association of American Medical Colleges 03/2012; 87(5):662-7. · 2.34 Impact Factor
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    ABSTRACT: Most previous studies of pediatric out-of-hospital cardiac arrest have typically examined relatively small datasets from small study regions. Although several studies have reported the impact on adult out-of-hospital cardiac arrest, little information is available on the impact of telephone dispatcher assistance on the outcomes of pediatric out-of-hospital cardiac arrest. We set out to examine the impact of cardiopulmonary resuscitation instruction by telephone dispatcher on the outcomes of pediatric out-of-hospital cardiac arrest. Population-based, observational study. Japan-wide population-based setting. We identified 1,780 pediatric out-of-hospital cardiac arrest patients (67.8% male) with witnessed collapse from a nationwide, population-based, out-of-hospital cardiac arrest database. None. We assessed the impact of telephone dispatcher assistance on the outcomes of 1-month survival rates and favorable neurologic status among the groups. The overall rate of bystander-performed chest compression and mouth-to-mouth ventilation among the witnessed pediatric out-of-hospital cardiac arrests were 39.5% and 25.6%, respectively. Telephone dispatcher assistance was offered in 28.4% of the witnessed pediatric out-of-hospital cardiac arrest cases and resulted in a significant increase in both chest compression (adjusted odds ratio 6.04; 95% confidence interval 4.72-7.72) and mouth-to-mouth ventilation (adjusted odds ratio 3.10; 95% confidence interval 2.44-3.95), and a significant improvement in 1-month survival rate (adjusted odds ratio 1.46; 95% confidence interval 1.05-2.03), but no significant effect on favorable neurologic outcomes at 1 month (adjusted odds ratio 1.15; 95% confidence interval 0.70-1.88). Potential confounding factors included age categories, sex, bystander type, cause of cardiac arrest, bystander cardiopulmonary resuscitation, and attempted defibrillation. Telephone dispatcher assistance could significantly increase bystander cardiopulmonary resuscitation among witnessed pediatric out-of-hospital cardiac arrests. Although there was only a small, nonsignificant effect on the improvement in favorable neurologic outcome at 1 month, the improved survival associated with telephone dispatcher assistance in pediatric out-of-hospital cardiac arrest is clinically important, and is of major public health importance. In cases where cardiac arrest was uncertain from the bystander's replies during the call to emergency medical services, telephone dispatcher assistance was not offered, which could affect the adjusted odds ratio of the present study.
    Critical care medicine 03/2012; 40(5):1410-6. · 6.37 Impact Factor
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    ABSTRACT: Japan experienced a nationwide outbreak of hydrogen sulfide suicides (HSS) between April and May 2008. The annual number of HSS skyrocketed from 19 in 2007 to 1,056 in 2008. However, the factors affecting this enormous increase remain unknown. The present study aimed to examine the effect of media coverage of the incidents on the subsequent epidemic of HSS. We collected time series data from the 1st week of February to the last week of September 2008 (34 weeks), including the number of HSS (St), the number of articles on HSS published in the five major newspapers (Nt), and the number of Internet searches with the keyword "hydrogen sulfide suicide" (Gt). The generalized method of moments was applied to model the concurrent effects of Nt and Gt on St. The increase in the number of newspaper articles significantly induced the increase in HSS (coefficient, 0.84; 95% confidence interval (CI), 0.28-5.3), while the number of Internet searches did not significantly affect the number of HSS (coefficient, -0.75; 95% CI, -19.3-0.45). Exposure to information on HSS from newspaper articles could have directly affected the subsequent increase in the number of suicides. On the other hand, the number of the Internet searches did not have a direct influence on HSS.
    The International Journal of Psychiatry in Medicine 01/2012; 44(2):133-40. · 1.15 Impact Factor
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    ABSTRACT: The percentage of females in the physician workforce is increasing in Japan, as in other countries; however, the working status of female physicians has not been sufficiently investigated. Original data were obtained from the National Survey of Physicians (NSP) conducted by the Ministry of Health, Labour and Welfare, Japan, from 1984 to 2004. We examined the trend of female physicians' areas of practice and analyzed their leave, return to work, and change in areas of practice using cohort data. The percentage of female physicians has increased significantly in recent generations, especially in surgery, surgical subareas of practice, and obstetrics and gynecology. A remarkable increase was found in obstetrics and gynecology among women under 29 years old from 15.4 to 66.2%. The total number of female physicians on leave has been higher than the number of female physicians returning since 1998. The average percentage of those who changed their area of practice was high in surgery (20.7%) and low in pediatrics (5.0%) and obstetrics and gynecology (1.7%). A strategic plan is needed for future health policy to plan for the physician workforce, especially for the areas of practice with increasing proportions of young female physicians.
    Health Policy 09/2011; 105(2-3):214-20. · 1.51 Impact Factor
  • Prehospital Emergency Care 08/2011; 15(4):579-80. · 1.86 Impact Factor
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    ABSTRACT: The constructs of mesenchymal stem cells and ceramics form bone tissue after implantation. Therefore, the constructs can include cultured bone (tissue-engineered bone) as bone grafts. However, the selection of constructs, prior to implantation, with high osteogenic potential is still difficult. We used a rat model to measure the secretory osteocalcin level in culture medium to verify that monitoring osteocalcin levels enables the selection of constructs with high osteogenic potential. We prepared constructs of rat hydroxyapatite/cells and used different cell passages of P-1 and P-3 as well as different cell numbers: 1 × 10(5) and 1 × 10(6) cells/ml suspension. These constructs were cultured for 14 days under osteoinductive or nonosteoinductive conditions and implanted subcutaneously in the recipient rat. Secretory osteocalcin in the culture medium was measured using an enzyme-linked immunosorbent assay system during the culture period until day 14, and the osteocalcin content of the harvested construct at 4 weeks was also measured. All constructs except the hydroxyapatite/P-3 construct showed abundant bone formation by histology and both high secretory osteocalcin level in the medium and high osteocalcin content after implantation. Our study revealed that secretory osteocalcin level in vitro was related to osteocalcin content in vivo. The study clearly showed that measuring secretory osteocalcin is a nondestructive method of assessing the osteogenic potential of tissue-engineered bone. One can choose tissue-engineered bone with high osteogenic potential by integrating secretory osteocalcin measurement into the process of bone-tissue regeneration.
    Journal of Orthopaedic Science 07/2011; 16(5):622-8. · 0.96 Impact Factor
  • Hideo Yasunaga, Toru Sugihara, Tomoaki Imamura
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    ABSTRACT: To use a contingent valuation method to compare the willingness of well-informed and ill-informed men to pay for PSA screening. Prostate cancer screening by analysis of prostate-specific antigen (PSA) levels has recently been confirmed to reduce prostate cancer death. However, PSA screening is associated with considerable risks, and men should be well informed about the risks before deciding to undergo the test. A total of 1800 men aged 50-69 years old participated in an Internet-based, computer-assisted questionnaire survey. The subjects were randomly divided into 2 groups. Group 1 (n = 900) was provided with information about the procedure, detection rate, and mortality-reducing effects of PSA screening. Additional information was given to group 2 (n = 900), including the possibility of false-positive or false-negative results, the risks of close examination, and the possibility of overdiagnoses. The willingness to pay (WTP) was assessed using a double-bound dichotomous choice method. The average WTP was significantly greater in group 1 than in group 2 ($31.1 vs $25.1, P < .01). Weibull regression analysis showed that patients with a history of receiving PSA screening or with greater incomes had a significantly greater WTP. Although providing information on the risks of PSA screening significantly decreased men's WTP for such tests, the well-informed group was still willing to pay $25.1. These findings suggest that men can balance the potential disadvantages of PSA screening against its effectiveness in saving lives.
    Urology 06/2011; 77(6):1325-9. · 2.42 Impact Factor

Publication Stats

424 Citations
166.02 Total Impact Points

Institutions

  • 2008–2013
    • Nara Medical University
      • Department of Public Health, Health Management and Policy
      Nara-shi, Nara, Japan
  • 2006–2012
    • The University of Tokyo
      • • Faculty & Graduate School of Medicine
      • • Department of Health Science and Nursing
      Tokyo, Tokyo-to, Japan
  • 2011
    • National Institute of Public Health
      Saitama, Saitama, Japan
  • 2005–2011
    • Tokyo Medical University
      Edo, Tōkyō, Japan
    • Kyushu University
      • Department of Dermatology
      Fukuoka-shi, Fukuoka-ken, Japan
  • 2002
    • Ministry of Health, Labour and Welfare - Japan
      Edo, Tōkyō, Japan