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Yosikazu Nakamura

Publications and source records attributed to Yosikazu Nakamura.

At least 19 recordsLinked to original sources
PubMed2007

Metabolic syndrome and C-reactive protein in the general population: JMS Cohort Study.

BACKGROUND: In recent years some studies have shown that metabolic syndrome (MS) is associated with inflammation, indicated by high-sensitivity C-reactive protein (hsCRP), but there have been few population-based studies, especially in Japan. METHODS AND RESULTS: The study subjects were 2,191 men and women examined between 1992 and 1995 with the necessary data to ascertain MS as part of the Jichi Medical School Cohort Study. CRP was measured by nephelometry. There were 109 subjects defined as having MS (5.0%), and the proportion of MS cases was higher in men (9.4%) than in women (1.8%). Geometric mean and median CRP in the MS group was higher than that in the non-MS (geometric mean; p<0.001, median: 0.312 mg/L in MS and 0.122 mg/L). Proportion of MS increased with CRP, after the subjects were divided by tertile of CRP (odds ratio, 95% confidence interval 1st tertile as a reference; 2nd tertile: 2.9, 1.5-5.9, 3rd tertile: 5.7, 3.1-11.1). CONCLUSION: Inflammation, measured by the concentration of hsCRP, was elevated in cases of MS in the general Japanese population. Longitudinal data should be examined in the future.

Adult↗
PubMed2007

Geographic difference of mortality of Creutzfeldt-Jakob disease in Japan.

BACKGROUND: The geographic mortality difference of Creutzfeldt-Jakob disease is still unclear in Japan. METHODS: Using vital statistics of Japan for 6 year period between 1999 and 2004 officially published by the government, we observed the mortality from Creutzfeldt-Jakob disease (ICD-10th: A81.0 and A81.8) by prefecture. Standardized mortality ratios were calculated for the 47 prefectures. RESULTS: For the observed 6 years, a total of 792 deaths from Creutzfeldt-Jakob disease were observed whole in Japan. Two prefectures, Akita and Yamanashi, presented significantly high standardized mortality ratios. In addition, Tochigi, Kochi, and Nagasaki showed standardized mortality rates higher than 1.5 without significance. No prefecture had significantly low standardized mortality ratios. CONCLUSION: Some prefectures with high mortality rate from Creutzfeldt-Jakob disease existed in Japan. Some of them had high incidence rate in a survey conducted in 1996 as well.

Adolescent↗
PubMed2006

Body mass index and risk of stroke mortality among a random sample of Japanese adults: 19-year follow-up of NIPPON DATA80.

BACKGROUND: The relationship between body mass index (BMI) and stroke mortality remains unclear. The aim of the present study was to elucidate the relationship between BMI and stroke death in a representative cohort of Japanese men and women. METHODS: We analyzed a database of 9,526 men and women aged 30 years and older who were randomly selected throughout Japan in 1980. These individuals had no history of stroke and were followed for 19 years. Hazard ratios (HR) and their 95% confidence intervals (CI) of deaths due to total stroke, cerebral infarction, and intracerebral hemorrhage were examined using Cox's proportional hazards regression models of BMI levels. RESULTS: A U-shaped association between BMI and cerebral infarction mortality was observed. Participants with the highest BMI category (BMI > or = 30.0) showed a significantly highest HR for cerebral infarction (HR 2.46, 95% CI 1.01-5.99). The excess risk at the lower extreme of the BMI was confined to men. These associations did not change after excluding deaths occurring in the first 2 years of follow-up. CONCLUSIONS: In the Japanese general population, a U-shaped association between BMI and cerebral infarction mortality was found and the excess risk at the lower extreme of the BMI was confined to men.

Adult↗
PubMed2006

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

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 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.

Acute Disease↗
PubMed2006

Effectiveness of cervical cancer screening over cervical cancer mortality among Japanese women.

BACKGROUND: Various studies have revealed that cervical cancer (CC) screening significantly reduces both CC incidence and mortality in developed countries. Although Japan introduced a nationwide government funded annual CC screening for the women aged 30+ in 1982, the effectiveness of CC screening on CC mortality has not yet been evaluated by any prospective cohort study. Therefore, the present study evaluated the association of CC mortality with self-reported CC screening and some other factors by a nationwide cohort study. METHODS: Baseline survey of the Japan Collaborative Cohort Study for the enrollment of subjects was completed during 1988-90 and followed until 2003. This study only analyzed 63,541 women, aged 30-79 years, who were free from any cancer history at enrollment. RESULTS: During the follow-up period, 38 CC deaths were identified. The mean age at mortality was 67.0 years, with a mortality rate of 4.2 per 100,000 person-years. Participation rate in CC screening was 46.9%. Age-adjusted Cox model indicated significantly lower CC mortality [hazard ratio (HR) = 0.30, 95% confidence interval (CI) = 0.12-0.74] due to CC screening. Protectiveness remained almost the same (HR = 0.30, 95% CI = 0.12-0.76) when adjusted for age, body mass index and number of deliveries. The results also revealed that CC screening could reduce at least 50% of CC deaths even after excluding the effect of possible self-selection bias. CONCLUSIONS: CC screening in Japan may reduce CC mortality significantly for women aged 30-79 years. However, further studies with more CC deaths and increased statistical power are needed to validate the findings.

Adult↗
PubMed2006

Prevalence and risk factors for hepatitis C virus infection in Mongolian children: Findings from a nationwide survey.

Although the hepatitis C virus (HCV) infection is one of the major causes of chronic hepatitis and hepatocellular carcinoma (HCC) in Mongolia, its prevalence among children and routes of transmission are largely unknown. The aim of the study was to determine the prevalence of anti-HCV antibodies and the possible risk factors for transmission among school children using representative national data. A nationwide cross-sectional survey among elementary school children was conducted in four main geographical regions and the metropolitan area of Mongolia, through multistage, stratified, random cluster sampling. Serum samples from 1,145 children (response rate, 93%; 592 boys and 553 girls; age range, 7-12 years), which represented nearly 2% of the second grade population in Mongolia, were tested for HCV antibodies with a third-generation immunoradiometric assay (IRMA). Positive samples were further evaluated by a third-generation immunoblot assay (RIBA). A standardized questionnaire concerning the socio-demographic characteristics and potential risk factors was used. Overall, seven subjects were confirmed to be anti-HCV seropositive, giving a prevalence of 0.6% (95% CI: 0.15-1.0%). The prevalence of anti-HCV increased with age. In the multivariate logistic regression analysis, adjusted for age, sex, and residence, the history of dental manipulation (odds ratio [OR] = 15.4; 95% CI: 1.4-164.8) and surgery (OR = 8.3; 95% CI: 1.5-45.6) were associated independently with the presence of anti-HCV. These findings suggest that contaminated equipment used in the dental and surgical manipulations probably played a predominant role in HCV transmission among Mongolian children. Strict guidelines on disinfection and sterilization procedures of medical instruments have to be introduced and should be followed to improve the control of HCV infection in Mongolia.

Child↗
PubMed2006

Risk factors associated with the need for additional intravenous gamma-globulin therapy for Kawasaki disease.

AIM: To investigate the characteristics of patients with Kawasaki disease who needed intravenous gamma-globulin (IVGG) re-treatment. METHODS: Using the database of the 17th nationwide survey in Japan, a total 11,366 patients were identified and analysed (1,855 re-treatment patients and 9,511 responders). RESULTS: Multivariate logistic regression analysis showed that male sex (odds ratio (OR) 1.26; 95% CI 1.14-1.40), complete cases (OR 1.39; 95% CI 1.07-1.80), recurrence (OR 1.47; 95% CI 1.15-1.88), IVGG treatment within 4 d of illness (OR 2.05; 95% CI 1.84-2.27), daily dose of initial IVGG less than 1,000 mg/Kg (OR 0.54; 95% CI 0.48-0.61), exanthema (OR 2.03; 95% CI 1.62-2.56), lips and oral lesions (OR 1.57; 95% CI 1.24-1.98), peripheral extremities changes (OR 1.85; 95% CI 1.54-2.22), and cervical lymphadenopathy (OR 1.89; 95% CI 1.66-2.16) were independent risk factors associated with the need for IVGG re-treatment. CONCLUSION: Male sex, recurrence, and treatment with IVGG at a dose of 1,000 mg/d or less within 4 d of illness onset are independent risk factors associated with the need for IVGG re-treatment.

Exanthema↗
PubMed2006

Incidence of Kawasaki disease in Japan: the nationwide surveys of 1999-2002.

BACKGROUND: The purpose of the present study was to describe the results of nationwide epidemiologic surveys of Kawasaki disease for the 4 year period 1999-2002. METHODS: The design is a retrospective incidence survey. The patients reported in these two surveys are all new patients who were reported during the two study periods (1999-2000 and 2001-2002), although the data were collected retrospectively. A questionnaire was sent to all pediatric departments of hospitals with 100 beds or more throughout Japan, requesting data on patients with Kawasaki disease, such as sex, age, date of first hospital visit, recurrence, and cardiac lesions. RESULTS: The total number of patients reported in the 4 year period 1999-2002 was 32 266 (18 604 male, 13 662 female), with an average annual incidence of 137.7 per 100 000 children younger than 5 years old. The male/female ratio was 1.30. The incidence peaked at 9-11 months of age, and the proportion of patients under 1 year of age was 26%. The monthly distribution had a high peak in January and a gradual increase in summer. Geographically, the high-incidence areas were limited to certain prefectures and moved from year to year. The cardiac lesions at acute stage and cardiac sequelae occurred more in children under 1 year and older than 4 years. Among the principal symptoms, fever persisting >or=5 days occurred most commonly, followed by conjunctival congestion, changes in lips and oral cavity, polymorphous exanthema, and changes of extremities. Cervical lymphadenopathy occurred less. CONCLUSION: More than 32 000 patients with Kawasaki disease during the 4 year period 1999-2002 were reported to the nationwide incidence surveys. The number of patients is steadily increasing despite the decrease of children. The seasonal variation, geographical distribution, and age-specific distribution support the infection theory for the etiology of Kawasaki disease.

Age Distribution↗
PubMed2006

Effects of dioxins on the quantitative levels of immune components in infants.

Dioxins (polychlorinated dibenzo-p-dioxin (PCDD)+polychlorinated dibenzofuran (PCDF)) and polychlorinated biphenyls (PCBs) are potentially hazardous compounds and have structural similarity with thyroid hormones. Animal studies have demonstrated that PCDDs, PCDFs and PCBs can alter immune functions. However, in humans it is not yet elucidated whether dioxins contained in breast milk have any effects on the immune functions in infants. To investigate the effects of dioxins on the immune system, we compared the quantitative levels of immune components between a breast-fed group and bottle-fed group, in which dioxin concentration is almost zero. Ratios of immune cells, such as CD4+ and CD8+ T-lymphocytes, as well as B-lymphocytes (CD19+ and/or CD20+) and NK cells (CD16+, CD56+) in peripheral blood lymphocytes, serum immunoglobulin level, and level of specific IgE antibody to allergens in the venous blood at 12 months of age were assessed in a subgroup of 281 infants. The relationship of post-natal dioxin exposure via breast feeding with the ratio of immunological markers and the level of humoral antibodies up to 12 month of age was not demonstrated. In conclusion, it would appear that the content of dioxins in breast milk in the Japanese general population is not enough to induce any change in theses-examined immunological parameters during the first year of life, although long-term effects remain to be evaluated.

Adult↗
PubMed2006

Age at menopause and mortality in Japan: the Jichi Medical School Cohort Study.

BACKGROUND: Although several studies have reported increased mortality risk with early menopause, there were no studies examining the relationship between age at menopause and mortality in Japan. The goal of this analysis is to investigate the relationship between age at menopause and all-cause mortality among the Japanese. METHODS: Study subjects were 4,683 postmenopausal females in the Jichi Medical School Cohort Study, a population-based prospective study. Baseline data were obtained by questionnaire and health checkups between April 1992 and July 1995 in 12 rural areas in Japan. Main outcome measures were all-cause mortality derived from death certificates up to December 31, 2002. Cox's proportional hazard models were used to analyze the association of age at menopause with mortality. RESULTS: A total of 215 deaths were observed during the average of 9.2 year follow-up period. After adjusting for age, systolic blood pressure, serum total cholesterol level, serum high density lipoprotein cholesterol level, history of diabetes mellitus, body mass index, smoking habits, alcohol drinking habits, marital status, study area, and types of menopause, the hazard ratios (95% confidence intervals) of all-cause mortality were 2.10 (1.07-4.11), 0.68 (0.36-1.26), 0.94 (0.68-1.30), and 1.17 (0.63-2.20) for females with a menopause at ages younger than 40 years, 40-44, 50-54, and 55 or older, respectively, relative to those with menopause at age 45-49 years. CONCLUSIONS: Our data suggest that menopause aged younger than 40 years increases the risk of death from all causes among the Japanese.

Adult↗
PubMed2006

Social class inequalities in self-rated health and their gender and age group differences in Japan.

BACKGROUND: Few studies have examined social inequalities in self-rated health in Japan, and the issue of gender differences related to social inequalities in self-rated health remains inconclusive. METHODS: The data derived from interviews with 2987 randomly selected Japanese adults in four prefectures in Japan who completed the cross-national World Mental Health survey from 2002 through 2005. We calculated odds ratios (ORs) of having poor self-rated physical and mental health by two social class indicators independently with multivariate logistic regression models, adjusted for age, gender, marital status, and area. Stratified analyses by gender and age group were also conducted. RESULTS: The adjusted ORs of the lowest educational attainment category having poor self-rated physical and mental health were 1.42 (95% confidence interval [CI]: 1.15-1.76) and 1.37 (95% CI: 1.10-1.70), respectively. Among females, educational attainment had significant linear associations with self-rated physical and mental health. Adjusted household income was also significantly associated with self-rated physical health among female respondents. No associations were found among males. While educational attainment was associated with self-rated health among the young age group, adjusted household income was associated with self-rated physical health in the middle and old age group. CONCLUSION: These results indicated social inequalities in self-rated health and prominent social inequalities in self-rated health among females in Japan. Social inequalities in self-rated health seemed to exist across age groups. However, the mechanism of social inequalities in self-rated health could be different depending on the age group.

Adult↗
PubMed2006

Comprehensive health education combining hot spa bathing and lifestyle education in middle-aged and elderly women: one-year follow-up on randomized controlled trial of three- and six-month interventions.

BACKGROUND: This study attempted to clarify the duration of effects of 3- and 6-month comprehensive health education programs based on hot spa bathing, lifestyle education and physical exercise for women at 1-year follow-up. METHODS: We examined middle-aged and elderly women who were randomly divided into two groups and followed up them for one year. Spa programmers instructed subjects for one hour in lifestyle education and physical exercise and for one hour in a half bath (salt spring, temperature at 41.5 degrees C) once a week. The program for the 3-month group (n=19) was repeated in the 6-month group (n=14). The evaluation items were body mass index, PWC75%HRmax (by a bicycle ergometer as aerobic capacity), blood profiles (total cholesterol, HDL cholesterol, arteriosclerotic index, uric acid, and hemoglobin A1c), profile of mood states, self-rating depression scale, subjective happiness, pains in the knee and back, and active modification of lifestyle. RESULTS: There were significant interactions between groups and response over time to aerobic capacity, hemoglobin A1c, back pain, vigor, fatigue and self-rating depression (respectively, p<0.05). Duration of effects was longer for the 6-month intervention than for the 3-month intervention. CONCLUSIONS: Beneficial effects of 6-month intervention on hemoglobin A1c, aerobic capacity, pains in the back, vigor, fatigue and depression remained significant at the 1-year follow-up. Duration of effects was longer in the 6-month intervention than in the 3-month intervention.

Adult↗
PubMed2006

Hepatitis delta virus infection in mongolia: analyses of geographic distribution, risk factors, and disease severity.

The prevalence and risk factors for hepatitis delta virus (HDV) infection among Mongolian school children were assessed by detecting the antibody against HDV and HDV RNA, and through structured interviews. The study subjects consisted of 181 children with the past or ongoing hepatitis B virus infection who were investigated during the nationwide serosurvey conducted in 2004. The prevalence of antibody to HDV was 6.1%, with the proportion of 13.6% among hepatitis B surface antigen (HBsAg)-positive subjects, all of whom had HDV RNA. Multivariate logistic regression analyses showed that injections (> 11 times) (odds ratio [OR] = 8.31, 95% confidence interval [CI] = 1.28-54.07) and blood sampling (> 3 times) (OR = 5.34, 95% CI = 1.12-25.53) in health care settings, hospitalization (> 3 times) (OR = 6.20, 95% CI = 1.18-32.71), and cohabitating with patients with chronic hepatitis (OR = 4.57, 95% CI = 1.26-16.55) predicted the seropositivity for antibody to HDV. These results suggest that parenteral exposures in health care settings and household transmission are the main routes of HDV transmission among Mongolian children.

Antibodies, Viral↗
PubMed2005

Congener profiles of PCDDs, PCDFs, and dioxin-like PCBs in the breast milk samples in Tokyo, Japan.

Exposure to dioxins has raised much public concern recently. We determined the congeners' distribution of polychlorinated-dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs) in the breast milk samples collected in Tokyo, Japan. Breast milk was taken from 240 mothers, 30 days after delivery in 1999 and 2000 in Tokyo, Japan. The actual concentration and TEQ concentration of PCDDs (14 congeners), PCDFs (15 congeners), and dl-PCBs (12 congeners), and each congener's contribution to the total TEQ level were calculated. Among all the samples, PCDDs accounted for 34.8%, PCDFs accounted for 23.5%, dl-PCBs accounted for 41.7%, which was also similar in the breast milk from the primiparae and secundiparae. The main contributors to the total TEQ with increasing percentages were 2,3,4,7,8-PeCDF, 1,2,3,7,8-PeCDD and 3,3',4,4',5-PCB (#126), and they accounted for more than 65% of the total TEQ. Detailed congener analysis in breast milk samples is effective to understand dioxin sources.

Benzofurans↗
PubMed2005

Human milk survey for dioxins in the general population in Japan.

BACKGROUND: Much attention has been paid to the level of dioxins in breast milk in Japan but few large-scale studies have been conducted on the subject. METHODS: From 1997 to 2002, we collected 839 samples of breast milk from primiparas residing throughout Japan. Starting in 1999, breast milk was also collected from secundiparas. Seven isomers of polychlorinated dibenzo-p-dioxins (PCDDs), 10 of polychlorinated dibenzofurans (PCDFs), 4 of coplanar polychlorinated biphenyls (Co-PCBs) and 8 of mono-orthochlorinated polychlorinated biphenyls (mono-ortho PCBs) were analyzed by employing gas chromatography and mass spectrometry. A correlation between the level of dioxins in human milk and the age of the mothers was noted for the primiparas and the secundiparas; and the levels were compared between the first and the second deliveries. Grouped by parity and prefecture in each year, observations were also made on the trends in these levels. Dioxin levels are shown by using geometric means because their distributions were skewed to the left. RESULTS: The sum of PCDDs and PCDFs, Co-PCBs, mono-ortho PCBs, and total dioxins in the breast milk of primiparas were 13.9, 5.4, 3.4, and 22.7 pg TEQ/g fat, respectively. In the samples obtained from secundiparas, these levels were 63-68 percents of those taken from the primiparas. The correlation coefficients between the PCDDs/DFs, Co-PCBs, mono-ortho PCBs, and total dioxins and the age of the primiparas were 0.19, 0.17, 0.36, and 0.24, respectively. All these correlations were statistically significant (p < 0.001). The positive correlations between these contaminants and the age of the secundiparas were also examined. The total dioxins as well as PCDDs/DFs, Co-PCBs, and mono-ortho PCBs in the breast milk of the primiparas declined significantly between 1998 and 2002 (regression coefficients: -0.04, -0.05, -0.03, and -0.03, respectively). However, no significant decline in these levels was observed when sorted by prefectures. CONCLUSIONS: Much attention should be paid to the age and parity of nursing mothers when investigating the relationship between the level of dioxins in breast milk and the body burden of infants.

Dioxins↗
PubMed2005

Relationship of PCDD/F and Co-PCB concentrations in breast milk with infant birthweights in Tokyo, Japan.

OBJECTIVE: To observe how PCDD/F and Co-PCB concentrations in breast milk relate to infant birthweights in Tokyo, Japan. STUDY DESIGN: Breast milk samples were collected from 240 mothers (aged 25-34years old) residing in Tokyo to measure the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs; 14 congeners), polychlorinated dibenzofurans (PCDFs; 15 congeners), and coplanar polychlorinated biphenyls (Co-PCBs; 12 congeners) in the breast milk fat. Individual milk samples (about 50ml) were obtained 30days after delivery, between the months of June and September in 1999 and 2000. The relationship of the infant birthweights with the PCDD/F and Co-PCB concentrations was observed. RESULTS: The birthweights were negatively correlated the concentrations of many of the PCDD/F and Co-PCB congeners, with the mean toxic equivalent quantities (TEQs) of the Co-PCBs, and with the sum of the PCDD, PCDF and Co-PCBs, although their correlation coefficients were less than 0.200. Multiple regression analysis showed octachlorodioxin was statistically significant explanatory variate. CONCLUSIONS: There were slight relationship between the dioxins levels of breast milk and the birthweights of the infants.

Adult↗
PubMed2005

Seasonality and temporal clustering of Kawasaki syndrome.

BACKGROUND: The distribution of a syndrome in space and time may suggest clues to its etiology. The cause of Kawasaki syndrome, a systemic vasculitis of infants and children, is unknown, but an infectious etiology is suspected. METHODS: Seasonality and clustering of Kawasaki syndrome cases were studied in Japanese children with Kawasaki syndrome reported in nationwide surveys in Japan. Excluding the years that contained the 3 major nationwide epidemics, 84,829 cases during a 14-year period (1987-2000) were analyzed. To assess seasonality, we calculated mean monthly incidence during the study period for eastern and western Japan and for each of the 47 prefectures. To assess clustering, we compared the number of cases per day (daily incidence) with a simulated distribution (Monte Carlo analysis). RESULTS: Marked spatial and temporal patterns were noted in both the seasonality and deviations from the average number of Kawasaki syndrome cases in Japan. Seasonality was bimodal with peaks in January and June/July and a nadir in October. This pattern was consistent throughout Japan and during the entire 14-year period. Some years produced very high or low numbers of cases, but the overall variability was consistent throughout the entire country. Temporal clustering of Kawasaki syndrome cases was detected with nationwide outbreaks. CONCLUSIONS: Kawasaki syndrome has a pronounced seasonality in Japan that is consistent throughout the length of the Japanese archipelago. Temporal clustering of cases combined with marked seasonality suggests an environmental trigger for this clinical syndrome.

Disease Outbreaks↗