Naohito Yamaguchi

Publications of Naohito Yamaguchi

• Changes in COPD mortality rate after amendments to the Preventive Vaccination Law in Japan.

  Authors: Kosuke Kiyohara, Noriko Kojimahara, Yasuto Sato, Naohito Yamaguchi

  European journal of public health. 12/2011;

  BACKGROUND: The Japanese government amended the Preventive Vaccination Law in November 2001 to specify elderly people aged ≥65 years as the target population for influenza vaccinations. The vaccineBACKGROUND: The Japanese government amended the Preventive Vaccination Law in November 2001 to specify elderly people aged ≥65 years as the target population for influenza vaccinations. The vaccine coverage among this age group rapidly increased thereafter. Our goal was to evaluate how this amendment affected the nationwide mortality rate of chronic obstructive pulmonary disease (COPD). METHODS: The number of monthly COPD deaths by gender and age was obtained from the Monthly Vital Statistics Reports of the Ministry of Health, Labour and Welfare. Data between January 1995 and December 2009 were used for analyses. The COPD mortality rate for each month was calculated separately for the two age groups: age <65 years and age ≥65 years. Changes in the COPD mortality rates after amendment were evaluated each month using the Poisson regression analysis to calculate risk ratios (RRs) and to compute 95% confidence intervals (95% CIs) adjusting for gender, age, trend and seasonal variations. RESULTS: After amendments to the law, a statistically significant reduction in the COPD mortality rates were observed in January (RR 0.84; 95% CI 0.81-0.88), February (RR 0.85; 95% CI 0.81-0.89) and March (RR 0.92; 95% CI 0.88-0.96) among the population aged ≥65 years. However, in the population aged <65 years, statistically no significant changes in the COPD mortality rate were found in any month after the amendments were made. CONCLUSION: A legal approach to improving influenza vaccine coverage for the elderly population would contribute to the risk reduction of COPD deaths during the influenza season.

• Lifestyle Factors as Predictors of General Cardiovascular Disease: Use for Early Self-Screening.

  Authors: Ying Li, Yasuto Sato, Naohito Yamaguchi

  Asia-Pacific journal of public health / Asia-Pacific Academic Consortium for Public Health. 12/2011;

  This study aims to examine the effectiveness of lifestyle factors in predicting general cardiovascular events and to investigate the feasibility of using the lifestyle model as a self-screening tool.This study aims to examine the effectiveness of lifestyle factors in predicting general cardiovascular events and to investigate the feasibility of using the lifestyle model as a self-screening tool. The authors conducted a longitudinal study over a 10-year follow-up in Japan. Logistic regression analysis was used to create prediction models for general cardiovascular disease (CVD) death. The authors estimated the predictive power of the models by calculating the area under the receiver operating characteristic (AUROC) curve. The total of 6 traditional and 5 lifestyle risk factors were significantly associated with the incidence of CVD events. Hazard ratios (HRs) were 0.26 (95% confidence interval [CI] = 0.17, 0.41) for regular physical activity, 0.57 (95% CI = 0.50, 0.67) for moderate- or high-intensity work, and 1.72 (95% CI = 1.31-2.26) for short sleep duration; the HRs for traditional and Western dietary patterns were 1.53 (95% CI = 1.12, 2.09) and 2.62 (95% CI = 1.46, 4.68), respectively. The AUROC curve was significantly different between the classic and lifestyle prediction models. These results suggest that lifestyle factors are significant predictors of CVD events.

• Estimation of the prevalence of latent abnormalities in the lung and the accuracy of indirect chest x-ray examination among Japanese workers of different age groups.

  Authors: Chika Takahashi, Satoru Shimizu, Noriko Kojimahara, Naohito Yamaguchi

  Industrial health. 06/2011; 49(4):511-6.

  It is considered that annual chest x-ray (CXR) examination can be restricted to workers by age; however, adequate epidemiological evidence is needed regarding the difference in the effectiveness ofIt is considered that annual chest x-ray (CXR) examination can be restricted to workers by age; however, adequate epidemiological evidence is needed regarding the difference in the effectiveness of CXR examination between younger and older age groups. This study attempted to estimate the prevalence of latent abnormalities (P) in the lung and the false negative rate (F) and false positive rate (G) of examinations among workers of different age groups. 112,482 subjects who were screened for three consecutive years with no findings at the first screening, were selected. The proportion of positive findings at the second screening and the proportion of negative findings at the third screening were incorporated into a stochastic model, and 5-yr-age-specific P, F, and G were estimated. P tended to increase with increasing age. F was 40-45% in <45-yr-old subjects and was only 10% in the older age groups. G showed a steady increase with increasing age. This study indicates that the nature of findings differs between younger and older age groups, and this difference affects the accuracy of examination. In Japan, the age of workers should be considered when a CXR examination is performed.

• Phase I/IIa trial of autologous formalin-fixed tumor vaccine concomitant with fractionated radiotherapy for newly diagnosed glioblastoma. Clinical article.

  Authors: Yoshihiro Muragaki, Takashi Maruyama, Hiroshi Iseki, Masahiko Tanaka, Chie Shinohara, Kintomo Takakura, Koji Tsuboi, Tetsuya Yamamoto, Akira Matsumura, Masao Matsutani, Katsuyuki Karasawa, Katsunori Shimada, Naohito Yamaguchi, Yoichi Nakazato, Keiki Sato, Youji Uemae, Tadao Ohno, Yoshikazu Okada, Tomokatsu Hori

  Journal of neurosurgery. 05/2011; 115(2):248-55.

  The objective of the present study was analysis of results of the prospective clinical trial directed toward the evaluation of therapeutic efficacy of the administration of autologous formalin-fixedThe objective of the present study was analysis of results of the prospective clinical trial directed toward the evaluation of therapeutic efficacy of the administration of autologous formalin-fixed tumor vaccine (AFTV) concomitant with fractionated radiotherapy in cases of newly diagnosed glioblastoma multiforme. Twenty-four patients were enrolled into the clinical trial, while 2 cases were excluded from the final analysis of results. The treatment protocol included aggressive tumor resection, fractionated radiotherapy up to a total dose of 60 Gy, and 3 concomitant courses of AFTV administered with an interval of one week at the late stage of irradiation. Two delayed-type hypersensitivity (DTH) tests were done--one 48 hours before the initial course of vaccination (DTH-1) and one 2 weeks after the third (DTH-2). All but one of the patients received salvage therapy at the time of tumor progression. The defined primary end point was overall survival; secondary end points were progression-free survival and safety of concomitant treatment. The median duration of overall survival was 21.4 months (95% CI 13.8-31.3 months). The actuarial 2-year survival rate was 40%. The median duration of progression-free survival was 7.6 months (95% CI 4.3-13.6 months). Overall survival showed a statistically significant association with recursive partitioning analysis class (p < 0.05); progression-free survival showed a statistically significant association with p53 staining index (p < 0.05) and size of DTH-2 response (p < 0.001). AFTV injection concomitant with fractionated radiotherapy was well tolerated by all patients and in no case did treatment-related adverse effects exceed Grade 1 toxicity; adverse effects were limited to local erythema, induration, and swelling at the site of injection. The results of this study demonstrate that AFTV treatment concomitant with fractionated radiotherapy may be effective in patients with newly diagnosed glioblastoma. Further clinical testing is warranted.

• A case-case study of mobile phone use and acoustic neuroma risk in Japan.

  Authors: Yasuto Sato, Suminori Akiba, Osami Kubo, Naohito Yamaguchi

  Bioelectromagnetics. 02/2011; 32(2):85-93.

  Results of case-control studies of mobile phone use and acoustic neuroma have been inconsistent. We conducted a case-case study of mobile phone use and acoustic neuroma using a self-administeredResults of case-control studies of mobile phone use and acoustic neuroma have been inconsistent. We conducted a case-case study of mobile phone use and acoustic neuroma using a self-administered postal questionnaire. A total of 1589 cases identified in 22 hospitals throughout Japan were invited to participate, and 787 cases (51%) actually participated. Associations between laterality of mobile phone use prior to the reference dates (1 and 5 years before diagnosis) and tumor location were analyzed. The overall risk ratio was 1.08 (95% confidence interval (CI), 0.93-1.28) for regular mobile phone use until 1 year before diagnosis and 1.14 (95% CI, 0.96-1.40) for regular mobile phone use until 5 years before diagnosis. A significantly increased risk was identified for mobile phone use for >20 min/day on average, with risk ratios of 2.74 at 1 year before diagnosis, and 3.08 at 5 years before diagnosis. Cases with ipsilateral combination of tumor location and more frequently used ear were found to have tumors with smaller diameters, suggesting an effect of detection bias. Furthermore, analysis of the distribution of left and right tumors suggested an effect of tumor-side-related recall bias for recall of mobile phone use at 5 years before diagnosis. The increased risk identified for mobile phone users with average call duration >20 min/day should be interpreted with caution, taking into account the possibilities of detection and recall biases. However, we could not conclude that the increased risk was entirely explicable by these biases, leaving open the possibility that mobile phone use increased the risk of acoustic neuroma.

• Immune response to influenza vaccine in the elderly: association with nutritional and physical status.

  Authors: Masano Sagawa, Noriko Kojimahara, Nobuo Otsuka, Mitsuru Kimura, Naohito Yamaguchi

  Geriatrics & gerontology international. 01/2011; 11(1):63-8.

  To investigate the distribution of hemagglutination inhibition (HI) titers before and after influenza vaccination and to examine the relationship between physical and nutritional factors and theTo investigate the distribution of hemagglutination inhibition (HI) titers before and after influenza vaccination and to examine the relationship between physical and nutritional factors and the change in HI titer after influenza vaccination in the elderly. Pre-post-vaccination HI titers were determined from 203 individuals aged 65 years or older residing in a nursing home. For the assessment of physical and nutritional status, information was retrieved from care records. The immune response to vaccination was assessed as good in 122 subjects based on a fourfold rise or more in HI titer after vaccination for at least one of three vaccine strains. In univariate logistic regression analysis with poor versus good immune response as the dependent variable, factors found to be significantly associated with a poor immune response were disability, a combination of body mass index less than 18.5 and bodyweight loss in 6 months or 5% or more, mid-upper-arm circumference of less than 80%, arm muscle circumference of less than 80% and total protein of less than 6.5 g/dL. Physical and nutritional indicators might be useful in identifying individuals who are unlikely to have a good immune response to influenza vaccination. In a multivariate analysis, the association remained significant for a low level of activities of daily living and a combination of body mass index of less than 18.5 and bodyweight loss in 6 months of 5% or more. Elderly individuals with poor physical and nutritional status tended to respond poorly to influenza vaccination. A low level of activities of daily living and a combination of being underweight and having had recent bodyweight loss are good indicators of a poor immune response.

• Power-Frequency Magnetic Fields and Childhood Brain Tumors: A Case-Control Study in Japan.

  Authors: Tomohiro Saito, Hiroshi Nitta, Osami Kubo, Seiichiro Yamamoto, Naohito Yamaguchi, Suminori Akiba, Yasushi Honda, Jun Hagihara, Katsuo Isaka, Toshiyuki Ojima, Yosikazu Nakamura, Tetsuya Mizoue, Satoko Ito, Akira Eboshida, Shin Yamazaki, Shigeru Sokejima, Yoshika Kurokawa, Michinori Kabuto

  Journal of epidemiology / Japan Epidemiological Association. 11/2009;

  Background: The strength of the association between brain tumors in children and residential power-frequency magnetic fields (MF) has varied in previous studies, which may be due in part to possibleBackground: The strength of the association between brain tumors in children and residential power-frequency magnetic fields (MF) has varied in previous studies, which may be due in part to possible misclassification of MF exposure. This study aimed to examine this association in Japan by improving measurement techniques, and by extending measurement to a whole week.Methods: This population-based case-control study encompassed 54% of Japanese children under 15 years of age. After excluding ineligible targeted children, 55 newly diagnosed brain tumor cases and 99 sex-, age-, and residential area-matched controls were included in the analyses. The MF exposures of each set of matching cases and controls were measured in close temporal proximity to control for seasonal variation; the average difference was 12.4 days. The mean interval between diagnosis and MF measurements was 1.1 years. The weekly mean MF level was defined as the exposure. The association was evaluated using conditional logistic regression analysis that controlled for possible confounding factors.Results: The odds ratios (95% CI) for exposure categories of 0.1 to 0.2, 0.2 to 0.4, and above 0.4 microT, against a reference category of <0.1 microT, were 0.74 (0.17-3.18), 1.58 (0.25-9.83), and 10.9 (1.05-113), respectively, after adjusting for maternal education. This dose-response pattern was stable when other variables were included in the model as possible confounding factors.Conclusions: A positive association was found between high-level exposure-above 0.4 microT-and the risk of brain tumors. This association could not be explained solely by confounding factors or selection bias.

• Quantifying the Impact of Selection Bias Caused by Nonparticipation in a Case-Control Study of Mobile Phone Use.

  Authors: Martine Vrijheid, Lesley Richardson, Bruce K Armstrong, Anssi Auvinen, Gabriele Berg, Matthew Carroll, Angela Chetrit, Isabelle Deltour, Maria Feychting, Graham G Giles [......] Siegal Sadetzki, Tina Salminen, Marie Sanchez, Birgitte Schlehofer, Joachim Schüz, Jack Siemiatycki, Tore Tynes, Alistair Woodward, Naohito Yamaguchi, Elisabeth Cardis

  Annals of epidemiology. 02/2009; 19(1):33-41.e1.

  PURPOSE: To quantitatively assess the impact of selection bias caused by nonparticipation in a multinational case-control study of mobile phone use and brain tumor. METHODS: Non-responsePURPOSE: To quantitatively assess the impact of selection bias caused by nonparticipation in a multinational case-control study of mobile phone use and brain tumor. METHODS: Non-response questionnaires (NRQ) were completed by a sub-set of nonparticipants. Selection bias factors were calculated based on the prevalence of mobile phone use reported by nonparticipants with NRQ data, and on scenarios of hypothetical exposure prevalence for other nonparticipants. RESULTS: Regular mobile phone use was reported less frequently by controls and cases who completed the NRQ (controls, 56%; cases, 50%) than by those who completed the full interview (controls, 69%; cases, 66%). This relationship was consistent across study centers, sex, and age groups. Lower education and more recent start of mobile phone use were associated with refusal to participate. Bias factors varied between 0.87 and 0.92 in the most plausible scenarios. CONCLUSIONS: Refusal to participate in brain tumor case-control studies seems to be related to less prevalent use of mobile phones, and this could result in a downward bias of around 10% in odds ratios for regular mobile phone use. The use of simple selection bias estimation methods in case-control studies can give important insights into the extent of any bias, even when nonparticipant information is incomplete.

• Routine coronary angiographic follow-up and subsequent revascularization in patients with acute myocardial infarction.

  Authors: Katsunori Shimada, Hiroshi Kasanuki, Nobuhisa Hagiwara, Hiroshi Ogawa, Naohito Yamaguchi

  Heart and vessels. 12/2008; 23(6):383-9.

  The aims of the present study are to: (1) clarify the angiographic follow-up (AFU) rate after discharge; (2) elucidate the characteristics of those undergoing it; and (3) determine the impact of AFUThe aims of the present study are to: (1) clarify the angiographic follow-up (AFU) rate after discharge; (2) elucidate the characteristics of those undergoing it; and (3) determine the impact of AFU on subsequent revascularization procedures among patients with acute myocardial infarction (AMI). Three thousand and twenty-one consecutive patients presenting within 48 h of AMI onset were enrolled from 17 centers in Japan between January 1999 and June 2001. To clarify the frequency of AFU and their characteristics, 2736 patients who survived at discharge were analyzed. Among 1160 patients matched by propensity score, the impact of AFU on subsequent revascularization was analyzed. Of 2736 patients, 1367 (50%) underwent AFU and constituted the lower-risk population. Of the 580 matched patient pairs, 120 (21%) in the clinical follow-up group and 198 (34%) in the AFU group underwent subsequent revascularization (hazard ratio 7.54; 95% confidence interval 5.74-9.91). Of the 198 patients in the AFU group, 157 (79%) underwent revascularization at the discretion of the responsible physician based on angiographic findings. Angiographic follow-up led to more subsequent revascularization. More evidence would be necessary to determine the effectiveness and the methods by which patients are selected.

• SAR characterization inside intracranial tumors for case-control epidemiological studies on cellular phones and RF exposure.

  Authors: Nadège Varsier, Kanako Wake, Masao Taki, Soichi Watanabe, Toru Takebayashi, Naohito Yamaguchi, Yuriko Kikuchi

  Annales des Télécommunications. 01/2008; 63:65-78.

• [Antibody levels in response to influenza and pneumococcal polysaccharide vaccine in elder diabetes patients]

  Authors: Noriko Kojimahara, Naohito Yamaguchi

  Kansenshogaku zasshi. The Journal of the Japanese Association for Infectious Diseases. 10/2007; 81(5):602-6.

• The INTERPHONE study: design, epidemiological methods, and description of the study population.

  Authors: Elisabeth Cardis, Lesley Richardson, Isabelle Deltour, Bruce Armstrong, Maria Feychting, Christoffer Johansen, Monique Kilkenny, Patricia McKinney, Baruch Modan, Siegal Sadetzki [......] Brigitte Schlehofer, Jack Siemiatycki, Masao Taki, Toru Takebayashi, Tore Tynes, Martie van Tongeren, Paolo Vecchia, Joe Wiart, Alistair Woodward, Naohito Yamaguchi

  European journal of epidemiology. 02/2007; 22(9):647-64.

  The very rapid worldwide increase in mobile phone use in the last decade has generated considerable interest in the possible health effects of exposure to radio frequency (RF) fields. A multinationalThe very rapid worldwide increase in mobile phone use in the last decade has generated considerable interest in the possible health effects of exposure to radio frequency (RF) fields. A multinational case-control study, INTERPHONE, was set-up to investigate whether mobile phone use increases the risk of cancer and, more specifically, whether the RF fields emitted by mobile phones are carcinogenic. The study focused on tumours arising in the tissues most exposed to RF fields from mobile phones: glioma, meningioma, acoustic neurinoma and parotid gland tumours. In addition to a detailed history of mobile phone use, information was collected on a number of known and potential risk factors for these tumours. The study was conducted in 13 countries. Australia, Canada, Denmark, Finland, France, Germany, Israel, Italy, Japan, New Zealand, Norway, Sweden, and the UK using a common core protocol. This paper describes the study design and methods and the main characteristics of the study population. INTERPHONE is the largest case-control study to date investigating risks related to mobile phone use and to other potential risk factors for the tumours of interest and includes 2,765 glioma, 2,425 meningioma, 1,121 acoustic neurinoma, 109 malignant parotid gland tumour cases and 7,658 controls. Particular attention was paid to estimating the amount and direction of potential recall and participation biases and their impact on the study results.

• Characteristics of medical school graduates who underwent problem-based learning.

  Authors: Keiko Matsui, Sonoko Ishihara, Taiyo Suganuma, Yasuto Sato, Ann C Tang, Yuriko Fukui, Naohito Yamaguchi, Yoriko Kawakami, Toshimasa Yoshioka

  Annals of the Academy of Medicine, Singapore. 01/2007; 36(1):67-71.

  INTRODUCTION: In this study, we compared the choice of medical specialty and subspecialty interest among problem-based-learning (PBL) graduates and non-PBL graduates. MATERIALS AND METHODS:INTRODUCTION: In this study, we compared the choice of medical specialty and subspecialty interest among problem-based-learning (PBL) graduates and non-PBL graduates. MATERIALS AND METHODS: Questionnaires were mailed to a total of 1398 female doctors who graduated from Tokyo Women's Medical University (TWMU) between 1989 and 2003. The response rate was over 30%, giving 248 respondents who had undergone a PBL curriculum (PBL+) and 220 subjects who had not (PBL-). Current specialty of the graduates were compared between the PBL+ and PBL-, and also compared with the general Japanese female doctors (Control 1 and 2) of similar age groups. Respondents were analysed in terms of their interests in subspecialty medical care or general medical practise, which includes comprehensive medical care, primary care and basic medicine. Internal medicine doctors working in the university hospitals were compared with those working outside the university hospitals. Internal medicine doctors were also compared with specialists in ophthalmology, otolaryngology, dermatology and psychiatry. Subjects were compared by odds ratio (OR) to examine group difference in the field of interest. OR >2.0 was considered statistically significant. RESULTS: Most doctors in all groups chose internal medicine. More PBL+ internal medicine doctors showed interests in comprehensive medical care and primary care; more PBL+ internal medicine doctors working outside university hospitals showed interest in comprehensive medical care and primary care when compared with those who were working in the university hospitals. The PBL- graduates did not show such a characteristic. CONCLUSIONS: More PBL+ graduates who chose internal medicine showed interest in holistic medical practices such as primary care and community medicine and more PBL+ specialists showed sustained interest in their respective fields.

• Association between high voltage overhead transmission lines and mental health: a cross-sectional study.

  Authors: Shin Yamazaki, Shigeru Sokejima, Tetsuya Mizoue, Akira Eboshida, Michinori Kabuto, Naohito Yamaguchi, Suminori Akiba, Shunichi Fukuhara, Hiroshi Nitta

  Bioelectromagnetics. 10/2006; 27(6):473-8.

  We examined the association between residential proximity to 60 Hz high voltage (22-500 kV) overhead transmission lines (HVOTLs) and mental health (MH). The subjects were 223 mothers with a mean ageWe examined the association between residential proximity to 60 Hz high voltage (22-500 kV) overhead transmission lines (HVOTLs) and mental health (MH). The subjects were 223 mothers with a mean age of 37 years. The distance from the subject's residence to the closest HVOTL was measured on a map. MH status was assessed by the SF-36 Health Survey, which was scored on a 0-100 point scale, and an individual with a score of 52 points or less was defined as having poor MH. Logistic regression models were used to examine the association between the distance from the subjects' residence to the closest HVOTL and MH status. The prevalence of poor MH was 15%. Among the 223 subjects, 10 lived within 100 m of a HVOTL. The adjusted odds ratios (OR) for poor MH among those who lived 101-300 m or within 100 m from HVOTL were 1.29 (95% confidence interval (CI): 0.35-10.13) and 1.87 (95% CI: 0.35-10.13), respectively, against the reference category (300+ m). MH status was not significantly associated with the distance between the subject's residence and the closest HVOTL.

• Cross-reactivity of influenza A (H3N2) hemagglutination-inhibition antibodies induced by an inactivated influenza vaccine.

  Authors: Noriko Kojimahara, Akiko Maeda, Tetsuo Kase, Naohito Yamaguchi

  Vaccine. 09/2006; 24(33-34):5966-9.

  The antigenic drift of influenza A (H3N2) virus in 2003-2004 necessitated a change in the vaccine from the A/Panama to the A/Wyoming strain for the 2004-2005 season. Using hemagglutinationThe antigenic drift of influenza A (H3N2) virus in 2003-2004 necessitated a change in the vaccine from the A/Panama to the A/Wyoming strain for the 2004-2005 season. Using hemagglutination inhibition, we therefore tested antibodies in sera of 39 individuals (mean age 64.6 years) at the end of the 2003-2004 season for cross-reactivity to vaccine strains and H3N2 antigens subject to antigenic drift. Antibodies against both A (H3N2) Panama and Wyoming developed in 5/13 (38.5%) unvaccinated individuals, whereas, 22/26 (84.6%) vaccinees developed antibodies to Panama and 21/26 (80.8%) to Wyoming. None of these individuals suffered an influenza episode that season. The results suggest that the elderly might develop protective levels of cross-reactive A (H3N2) Wyoming HI antibodies following vaccination with the Panama strain. Such strains, like the ones included in the 2003-2004 influenza vaccine, might be expected to provide a broad-spectrum antibody response that could be effective even in the face of single season antigenic drift.

• Childhood leukemia and magnetic fields in Japan: a case-control study of childhood leukemia and residential power-frequency magnetic fields in Japan.

  Authors: Michinori Kabuto, Hiroshi Nitta, Seiichiro Yamamoto, Naohito Yamaguchi, Suminori Akiba, Yasushi Honda, Jun Hagihara, Katsuo Isaka, Tomohiro Saito, Toshiyuki Ojima, Yosikazu Nakamura, Tetsuya Mizoue, Satoko Ito, Akira Eboshida, Shin Yamazaki, Shigeru Sokejima, Yoshika Kurokawa, Osami Kubo

  International journal of cancer. Journal international du cancer. 09/2006; 119(3):643-50.

  Residential power-frequency magnetic fields (MFs) were labeled as a possible human carcinogen by the International Agency for Research on Cancer panel. In response to great public concern, the WorldResidential power-frequency magnetic fields (MFs) were labeled as a possible human carcinogen by the International Agency for Research on Cancer panel. In response to great public concern, the World Health Organization urged that further epidemiologic studies be conducted in high-exposure areas such as Japan. We conducted a population-based case-control study, which covered areas inhabited by 54% of Japanese children. We analyzed 312 case children (0-15 years old) newly diagnosed with acute lymphoblastic leukemia (ALL) or acute myelocytic leukemia (AML) in 1999-2001 (2.3 years) and 603 controls matched for gender, age and residential area. Weekly mean MF level was determined for the child's bedroom. MF measurements in each set of a case and controls were carried out as closely in time as possible to control for seasonal variation. We evaluated the association using conditional logistic regression models. The odds ratios for children whose bedrooms had MF levels of 0.4 microT or higher compared with the reference category (MF levels below 0.1 microT) was 2.6 (95% CI=0.76-8.6) for AML+ALL and 4.7 (1.15-19.0) for ALL only. Controlling for some possible confounding factors did not alter the results appreciably. Even an analysis in which selection bias was maximized did not fully explain the association. Most of the leukemia cases in the highest exposure category had MF levels far above 0.4 microT. Our results provided additional evidence that high MF exposure was associated with a higher risk of childhood leukemia, particularly of ALL.

• [Nosocomial outbreak of scabies in a psychiatric hospital--epidemiological assessment and prophylactic treatment with oral ivermectin]

  Authors: Kuniko Makigami, Noriko Ohtaki, Yasuto Sato, Naohito Yamaguchi

  Nippon eiseigaku zasshi. Japanese journal of hygiene. 12/2005; 60(4):450-60.

  OBJECTIVES: To evaluate the effectiveness of mass treatment with ivermectin of scabies outbreak in institutional settings. To determine the factors, such as host susceptibility and scabetic exposureOBJECTIVES: To evaluate the effectiveness of mass treatment with ivermectin of scabies outbreak in institutional settings. To determine the factors, such as host susceptibility and scabetic exposure level associated with the onset of scabies. METHODS: The authors investigated a nosocomial scabies outbreak in a close psychiatric ward. The index case was a man with steroid-induced localized crusted scabies. Twenty-six patients were diagnosed with scabies, 4 of them had relapse of scabies, while no staff was infested. Despite frequent surveillance and treatment of symptomatic patients with 1% gamma-benzenehexachloride (gamma-BHC: Lindane), new cases were observed. Thus, all 69 patients in the ward were treated with ivermectin (200 microg/kg) simultaneously on day 105 of the outbreak (the mass treatment). Patients who had scabies were compared with patients who had no scabies in terms of age, body weight, diabetes, physical functions, topical administration of corticosteroid, proximity to the index patient, and problematic behavior. RESULTS: The mass treatment was implemented without a significant adverse event. Although two patients developed symptoms of scabies after the mass treatment, no patient in the ward had been diagnosed with scabies since the 98th day of the treatment. Regarding factors associated with the scabies onset, the only statistically significant factor was proximity to the index patient with crusted scabies. CONCLUSIONS: Oral ivermectin was safe and effective for controlling scabies in institutional settings. The exposure level to scabetic mites was more important than host susceptibility in determining the risk of scabies onset.

• [Cross-induction of HI antibody against A (H3N2) of influenza HA vaccine]

  Authors: Noriko Kojimahara, Akiko Maeda, Naohito Yamaguchi

  Kansenshogaku zasshi. The Journal of the Japanese Association for Infectious Diseases. 06/2005; 79(5):348-9.

• [Medical information service of clinical practice guidelines]

  Authors: Naohito Yamaguchi

  Nippon Geka Gakkai zasshi. 08/2003; 104(7):530-3.

• Causation of Borrmann type 4 gastric cancer: heritable factors or environmental factors?

  Authors: Ying Liu, Kimio Yoshimura, Naohito Yamaguchi, Kazuya Shinmura, Jun Yokota, Hitoshi Katai

  Gastric cancer : official journal of the International Gastric Cancer Association and the Japanese Gastric Cancer Association. 02/2003; 6(1):17-23.

  BACKGROUND: the prognosis of borrmann type 4 gastric cancer remains poor today. the relative contributions of genetic factors and nongenetic factors to type 4 gastric cancer are unclear. the study ofBACKGROUND: the prognosis of borrmann type 4 gastric cancer remains poor today. the relative contributions of genetic factors and nongenetic factors to type 4 gastric cancer are unclear. the study of family history and spousal history of cancer may play an important role in the assessment of causation of this severe gastric cancer. METHODS: during the period 1995-1997, 1118 consecutive patients with histologically confirmed gastric cancer (probands), including 113 with type 4 carcinoma, were admitted to the national cancer center hospital. the type of carcinoma, as well as the family history of cancer in first-degree relatives and spouses of the probands, was abstracted from medical records. family history and spousal history of cancer were compared between type 4 and other types of gastric cancer. RESULTS: while paternal history had no association with type 4 carcinoma compared with other types, maternal history was associated with a fourfold risk [95% confidence interval (ci), 1.6-9.3] of daughters' type 4 carcinoma, but not sons'. among probands whose wives had a history of gastric cancer, the risks of type 4 gastric cancer were significantly increased, to as high as 13-fold (95% ci, 2.5-65.3). however, husbands' history had no relationship with wives' type 4 carcinoma. no relationship between type 4 carcinoma and family history or spousal history of other cancers was observed. CONCLUSION: the present study suggested that environmental factors may have a key effect in causing type 4 carcinoma. the findings may be valuable for identifying subjects at high risk of such malignant gastric cancer as borrmann type 4.