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Papers by megumi nagano
American Journal of Human Biology, 2005
Pacific Islands populations can be broadly divided into Austronesians (AN) and Non-Austronesians ... more Pacific Islands populations can be broadly divided into Austronesians (AN) and Non-Austronesians (NAN); obesity and type 2 diabetes are prevalent in the former, although leptin levels in both groups have seldom been investigated. Thirty-seven (20 male and 17 female) adult pairs, matched by age and percent body fat, from AN-speaking Balopa and NAN-speaking Huli, all of whom migrated to settle in Port Moresby, the capital of Papua New Guinea, were selected for comparison of their serum leptin concentrations. The Balopa did not differ significantly from the Huli in age (30.5 AE 9.7 and 30.0 AE 8.7 years for males, 33.7 AE 8.9 and 34.1 AE 7.5 years for females, respectively) or percent body fat (19.4 AE 5.6 and 18.8 AE 4.6 for males, 34.1 AE 6.2 and 33.3 AE 5.0 for females), although the BMI of females was lower in the Balopa (26.4 AE 4.9) than in the Huli (29.7 AE 4.7) (P ¼ 0.02). In both ethnic groups, females had markedly higher leptin concentrations than males, but there was no significant inter-group difference in males (3.5 AE 2.6 and 3.1 AE 4.7 ng/ml, P ¼ 0.14) or females (22.7 AE 12.9 and 19.7 AE 11.9 ng/ml, P ¼ 0.40), after controlling for lifestyle factors and serum lipids. Multiple regression analysis revealed that significant predictors of leptin concentration were % body fat (b ¼ 0.58), sex (male, 0; female, 1; b ¼ 0.27), and smoker status (non-smoker, 0; smoker, 1; b ¼ À0.15) (R 2 ¼ 0.80), implying that the leptin concentration was primarily determined by lifestyle-derived body fatness. In conclusion, the NAN populations do not endogenously differ in leptin status from the AN populations, who have been recognized as a typical group with a ''thrifty'' genotype. Am.
Nippon Eiseigaku Zasshi (Japanese Journal of Hygiene), 1995
JOURNAL OF THE JAPANESE ASSOCIATION OF RURAL MEDICINE, 1983
Japanese Journal of Health and Human Ecology, 1988
Japanese Journal of Health and Human Ecology, 1996
Journal of Occupational Health, 1998
Journal of Occupational Health, 1998
Occupational Leukoderma in Workers Engaged in 4‐(p‐Hydroxyphenyl)‐2‐Butanone Manufacturing: Yoshi... more Occupational Leukoderma in Workers Engaged in 4‐(p‐Hydroxyphenyl)‐2‐Butanone Manufacturing: Yoshiharu Fukuda, et al. Department of Public Health, Kumamoto University School of Medicine—Occupational leukoderma was found to be caused by exposure to depigmentation agents. This is the first report associated with the depigmenting activity of 4‐(p‐Hydroxyphenyl)‐2‐butanone and its crude products. The purpose of this paper is to present three cases of occupational leukoderma in the upper extremities of workers engaged in the manufacturing of 4‐(p‐Hydroxyphenyl)‐2‐butanone. Two workers had symptoms of dermatitis in the same areas before depigmentation. An epidemiological study, their clinical courses and results of phototesting suggest that these cases of leukoderma were due to exposure to 4‐(p‐ hydroxyphenyl)‐2‐butanone and its crude products.
Journal of Occupational Health, 2000
Neurophysiological Changes in Rats Subchronically Treated with Styrene or Its Metabolites: Junich... more Neurophysiological Changes in Rats Subchronically Treated with Styrene or Its Metabolites: Junichi MISUMI, et al. Department of Public Health and Hygiene, Oita Medical University-The purpose of this study was to clarify the causative agent(s) in the peripheral neuropathy induced by styrene. Styrene 600 or 300, and its metabolites; hippuric acid 600 or 300; mandelic acid 300; styrene oxide 100; mg/kg were subcutaneously injected into rats for 10 to 12 wk. The changes in maximum sensory conduction velocity (SCV), maximum motor conduction velocity (MCV), and motor distal latency (DL) in the rat's tail nerve were tested. Compared with the control group, decreases in MCV, SCV, and an increase in DL were observed in the rats injected with styrene 600, styrene oxide 100 and mandelic acid 300 mg/kg. No significant changes were found in the rats treated with hippuric acid 300 or 600 mg/kg. The MCV and SCV values in the styrene oxide 100 and mandelic acid 300 mg/kg groups were significantly lower, and DL values were significantly longer than those in the styrene 600 mg/kg group. It is presumed that the neuropathy caused by styrene is related to the neurotoxicity of its intermediate metabolites, namely mandelic acid and styrene oxide. It appears that the neurotoxicity of mandelic acid needs to be further evaluated in styrene-produced neuropathy.
INDUSTRIAL HEALTH, 1998
Recently farm mechanization has been widespread and developing rapidly, in particular riding farm... more Recently farm mechanization has been widespread and developing rapidly, in particular riding farm machines are increasingly used in paddy fields in Japan. We have no information available on the actual situation regarding whole-body vibration on the seats of these farm machines from the standpoint of labour protection. Measurement and evaluation of whole-body vibration was performed on the seats of popular riding agricultural machineries. Whole-body vibration on the seats of combine harvesters and wheel tractors exceeded exposure limits and the fatigue-decreased proficiency boundary limit of 8 hr and also shortened the reduced comfort boundary limits of ISO 2631 (1985). Some combines, tractors and carieers had only less than one hour exposure duration as compared with the ISO 2631-1 standard (1997). On the other hand a questionnaire was also performed on the subject of agricultural machine operators. Any specific injury or other effects, i.e. low back injuries were not found among the group of operators as compared with those in non-operator farmers. It seems to be difficult to find out the health effects of whole-body vibration itself, because there may be a lot of causes, i.e. working posture, operating heavy materials, in farm working conditions.
Environmental Research, 2000
It is important to follow up on the health status of inhabitants living in the methyl mercury-pol... more It is important to follow up on the health status of inhabitants living in the methyl mercury-polluted area surrounding Minamata City, paying particular attention to diseases not only of the central nervous system but also of other organs. We have been carrying out such concentric studies for more than 10 years. We have previously studied the cause-speciAc standard mortality ratios in Minamata disease patients and reported that the SMRs for liver disease and renal disease were signiAcantly raised in male and female patients, respectively. It was also found that complications arising from diabetes could be due to the large number of old people among the autopsy cases. The next step was to clarify the actual prevalence and incidence of liver disease, renal disease, and diabetes mellitus epidemiologically among the population in this area. The aim of this study was to determine the actual prevalence of these diseases and complaints, and to investigate the contribution of various risk factors to these diseases in this area. The study was a population-based cross-sectional mass screening survey. A case-control study was designed to estimate the role of various risk factors including methyl mercury exposure for these diseases. A mass multiple health examination survey was performed in 1500 subjects aged 40 years and older in Tsunagi Town, neighboring Minamata City, every summer since 1984. Tsunagi Town is located in a methyl mercury-polluted area and there are 36.9 certiAed Minamata disease patients per 1000 population. Data concerning liver disease, renal disease, and diabetes mellitus were collected on the basis of urine, hematological, physical, and ultrasonographic examinations. Data on risk factors and subjective complaints were collected by interview and other measures. The prevalence of these diseases was not higher in this methyl mercury-polluted area compared with other areas in Japan, contrary to what was expected based on standard mortality ratios and pathological Andings. There were no positive correlations between those diseases and methyl mercury exposure. On the other hand, the population in the polluted area had more and a greater variety of complaints than those in the nonpolluted area. It is possible that not only neurological subjective complaints but also non-speciAc complaints of the population in the polluted area might be inBuenced by past methyl mercury exposure. This health surveillance in the population living in a methyl mercury-polluted area must be maintained in the future.
Environmental Research, 1993
JOURNAL OF THE JAPANESE ASSOCIATION OF RURAL MEDICINE, 1983
Journal of Occupational Health, 2002
Biological Monitoring of Styrene in FRP‐Making Small Industries in Kumamoto, Japan—Winter‐Summer ... more Biological Monitoring of Styrene in FRP‐Making Small Industries in Kumamoto, Japan—Winter‐Summer Difference and Effect of Protective Masks in Practical Working Conditions—: Tsukasa Inaoka, et al. Department of Public Health, Kumamoto University School of Medicine—Objective: Studies were carried out in Kumamoto, Japan to examine 1) the winter‐summer differences in the average individual exposure to styrene (8hr‐TWA) and to end‐shift‐urinary mandelic acid (MA in g/g Cr), 2) the possible seasonal difference in their relationship, and 3) the protective effect of a disposable particulate respirator containing charcoal fiber (called a “charcoal mask”) and a charcoal granule cartridge‐mask (called a “gas mask”) in the real working conditions. Methods: Approximately 100 male and female workers from about 10 small industries were subjected to the studies first in winter and second in summer. Individual exposure to styrene was monitored with a passive sampler during work time, and end‐shift‐u...
Study objective-The aim was to determine theactualprevalence ofliver disease andtoinvestigate the... more Study objective-The aim was to determine theactualprevalence ofliver disease andtoinvestigate thecontribution ofvariousriskfactors to liverdisease amongthepopulation inamethylmercury polluted area. Design-Thestudywas a population basedcrosssectional massscreening survey.A case-control studywasdesigned to estimate theroleofvarious riskfactors for liver diseases. Setting-The studywas confinedto a smallruraltown10km northofMinamata City. Subjects-1406 personsaged50to69years were examined (78-3%of the total population ofthisageinthelocality). Measurementsand main resultsMeasurements ofliver disease weremade onthebasis ofhaematological, physical, and ultrasonographic examinations. Data on liverriskfactors werecollected byquestionnaire, and by measurementofbody height, weight(obesity), andhepatitis B surfaceantigen(HBsAg).Theprevalence rateofliver tumourwas05% inmales, liver cirrhosis wasfoundin0-5%ofmalesand 0-1%offemales, andhepatitis wasseenin 5-4%of malesand 1P0% of females. Frequency...
International Journal of Dermatology, 2002
Background Arsenic contamination in groundwater affects 35 million people in Bangladesh, but the ... more Background Arsenic contamination in groundwater affects 35 million people in Bangladesh, but the prevalence of arsenic contamination in local communities remains to be clarified. As skin manifestations are sensitive markers of arsenicosis, we examined the skin of adults and adolescents in two villages to elucidate the severity of arsenicosis. Methods Five hundred and sixty-one villagers were randomly selected for the evaluation of their skin. Three indicators, i.e. keratosis on the soles, keratosis on the palms, and melanosis and hypopigmentation on the trunk, were quantified for analysis. Results More than 50% of the villagers showed some skin manifestations due to arsenicosis. Keratosis on the soles was the most sensitive marker for the detection of arsenicosis at an early stage. Interestingly, the skin manifestations were more severe in males than in females. There was no correlation between the age and the severity of skin manifestations. Conclusions The prevalence of arsenicosis was quite high and males were more vulnerable to arsenic contamination. Using skin manifestations, especially keratosis on the soles, as useful markers to detect and evaluate arsenicosis, it is clear that there is an urgent need to assess the exact prevalence and severity of arsenicosis in the population of Bangladesh in order to take measures to treat and control this problem.
American Journal of Human Biology, 2005
Pacific Islands populations can be broadly divided into Austronesians (AN) and Non-Austronesians ... more Pacific Islands populations can be broadly divided into Austronesians (AN) and Non-Austronesians (NAN); obesity and type 2 diabetes are prevalent in the former, although leptin levels in both groups have seldom been investigated. Thirty-seven (20 male and 17 female) adult pairs, matched by age and percent body fat, from AN-speaking Balopa and NAN-speaking Huli, all of whom migrated to settle in Port Moresby, the capital of Papua New Guinea, were selected for comparison of their serum leptin concentrations. The Balopa did not differ significantly from the Huli in age (30.5 AE 9.7 and 30.0 AE 8.7 years for males, 33.7 AE 8.9 and 34.1 AE 7.5 years for females, respectively) or percent body fat (19.4 AE 5.6 and 18.8 AE 4.6 for males, 34.1 AE 6.2 and 33.3 AE 5.0 for females), although the BMI of females was lower in the Balopa (26.4 AE 4.9) than in the Huli (29.7 AE 4.7) (P ¼ 0.02). In both ethnic groups, females had markedly higher leptin concentrations than males, but there was no significant inter-group difference in males (3.5 AE 2.6 and 3.1 AE 4.7 ng/ml, P ¼ 0.14) or females (22.7 AE 12.9 and 19.7 AE 11.9 ng/ml, P ¼ 0.40), after controlling for lifestyle factors and serum lipids. Multiple regression analysis revealed that significant predictors of leptin concentration were % body fat (b ¼ 0.58), sex (male, 0; female, 1; b ¼ 0.27), and smoker status (non-smoker, 0; smoker, 1; b ¼ À0.15) (R 2 ¼ 0.80), implying that the leptin concentration was primarily determined by lifestyle-derived body fatness. In conclusion, the NAN populations do not endogenously differ in leptin status from the AN populations, who have been recognized as a typical group with a ''thrifty'' genotype. Am.
Nippon Eiseigaku Zasshi (Japanese Journal of Hygiene), 1995
JOURNAL OF THE JAPANESE ASSOCIATION OF RURAL MEDICINE, 1983
Japanese Journal of Health and Human Ecology, 1988
Japanese Journal of Health and Human Ecology, 1996
Journal of Occupational Health, 1998
Journal of Occupational Health, 1998
Occupational Leukoderma in Workers Engaged in 4‐(p‐Hydroxyphenyl)‐2‐Butanone Manufacturing: Yoshi... more Occupational Leukoderma in Workers Engaged in 4‐(p‐Hydroxyphenyl)‐2‐Butanone Manufacturing: Yoshiharu Fukuda, et al. Department of Public Health, Kumamoto University School of Medicine—Occupational leukoderma was found to be caused by exposure to depigmentation agents. This is the first report associated with the depigmenting activity of 4‐(p‐Hydroxyphenyl)‐2‐butanone and its crude products. The purpose of this paper is to present three cases of occupational leukoderma in the upper extremities of workers engaged in the manufacturing of 4‐(p‐Hydroxyphenyl)‐2‐butanone. Two workers had symptoms of dermatitis in the same areas before depigmentation. An epidemiological study, their clinical courses and results of phototesting suggest that these cases of leukoderma were due to exposure to 4‐(p‐ hydroxyphenyl)‐2‐butanone and its crude products.
Journal of Occupational Health, 2000
Neurophysiological Changes in Rats Subchronically Treated with Styrene or Its Metabolites: Junich... more Neurophysiological Changes in Rats Subchronically Treated with Styrene or Its Metabolites: Junichi MISUMI, et al. Department of Public Health and Hygiene, Oita Medical University-The purpose of this study was to clarify the causative agent(s) in the peripheral neuropathy induced by styrene. Styrene 600 or 300, and its metabolites; hippuric acid 600 or 300; mandelic acid 300; styrene oxide 100; mg/kg were subcutaneously injected into rats for 10 to 12 wk. The changes in maximum sensory conduction velocity (SCV), maximum motor conduction velocity (MCV), and motor distal latency (DL) in the rat's tail nerve were tested. Compared with the control group, decreases in MCV, SCV, and an increase in DL were observed in the rats injected with styrene 600, styrene oxide 100 and mandelic acid 300 mg/kg. No significant changes were found in the rats treated with hippuric acid 300 or 600 mg/kg. The MCV and SCV values in the styrene oxide 100 and mandelic acid 300 mg/kg groups were significantly lower, and DL values were significantly longer than those in the styrene 600 mg/kg group. It is presumed that the neuropathy caused by styrene is related to the neurotoxicity of its intermediate metabolites, namely mandelic acid and styrene oxide. It appears that the neurotoxicity of mandelic acid needs to be further evaluated in styrene-produced neuropathy.
INDUSTRIAL HEALTH, 1998
Recently farm mechanization has been widespread and developing rapidly, in particular riding farm... more Recently farm mechanization has been widespread and developing rapidly, in particular riding farm machines are increasingly used in paddy fields in Japan. We have no information available on the actual situation regarding whole-body vibration on the seats of these farm machines from the standpoint of labour protection. Measurement and evaluation of whole-body vibration was performed on the seats of popular riding agricultural machineries. Whole-body vibration on the seats of combine harvesters and wheel tractors exceeded exposure limits and the fatigue-decreased proficiency boundary limit of 8 hr and also shortened the reduced comfort boundary limits of ISO 2631 (1985). Some combines, tractors and carieers had only less than one hour exposure duration as compared with the ISO 2631-1 standard (1997). On the other hand a questionnaire was also performed on the subject of agricultural machine operators. Any specific injury or other effects, i.e. low back injuries were not found among the group of operators as compared with those in non-operator farmers. It seems to be difficult to find out the health effects of whole-body vibration itself, because there may be a lot of causes, i.e. working posture, operating heavy materials, in farm working conditions.
Environmental Research, 2000
It is important to follow up on the health status of inhabitants living in the methyl mercury-pol... more It is important to follow up on the health status of inhabitants living in the methyl mercury-polluted area surrounding Minamata City, paying particular attention to diseases not only of the central nervous system but also of other organs. We have been carrying out such concentric studies for more than 10 years. We have previously studied the cause-speciAc standard mortality ratios in Minamata disease patients and reported that the SMRs for liver disease and renal disease were signiAcantly raised in male and female patients, respectively. It was also found that complications arising from diabetes could be due to the large number of old people among the autopsy cases. The next step was to clarify the actual prevalence and incidence of liver disease, renal disease, and diabetes mellitus epidemiologically among the population in this area. The aim of this study was to determine the actual prevalence of these diseases and complaints, and to investigate the contribution of various risk factors to these diseases in this area. The study was a population-based cross-sectional mass screening survey. A case-control study was designed to estimate the role of various risk factors including methyl mercury exposure for these diseases. A mass multiple health examination survey was performed in 1500 subjects aged 40 years and older in Tsunagi Town, neighboring Minamata City, every summer since 1984. Tsunagi Town is located in a methyl mercury-polluted area and there are 36.9 certiAed Minamata disease patients per 1000 population. Data concerning liver disease, renal disease, and diabetes mellitus were collected on the basis of urine, hematological, physical, and ultrasonographic examinations. Data on risk factors and subjective complaints were collected by interview and other measures. The prevalence of these diseases was not higher in this methyl mercury-polluted area compared with other areas in Japan, contrary to what was expected based on standard mortality ratios and pathological Andings. There were no positive correlations between those diseases and methyl mercury exposure. On the other hand, the population in the polluted area had more and a greater variety of complaints than those in the nonpolluted area. It is possible that not only neurological subjective complaints but also non-speciAc complaints of the population in the polluted area might be inBuenced by past methyl mercury exposure. This health surveillance in the population living in a methyl mercury-polluted area must be maintained in the future.
Environmental Research, 1993
JOURNAL OF THE JAPANESE ASSOCIATION OF RURAL MEDICINE, 1983
Journal of Occupational Health, 2002
Biological Monitoring of Styrene in FRP‐Making Small Industries in Kumamoto, Japan—Winter‐Summer ... more Biological Monitoring of Styrene in FRP‐Making Small Industries in Kumamoto, Japan—Winter‐Summer Difference and Effect of Protective Masks in Practical Working Conditions—: Tsukasa Inaoka, et al. Department of Public Health, Kumamoto University School of Medicine—Objective: Studies were carried out in Kumamoto, Japan to examine 1) the winter‐summer differences in the average individual exposure to styrene (8hr‐TWA) and to end‐shift‐urinary mandelic acid (MA in g/g Cr), 2) the possible seasonal difference in their relationship, and 3) the protective effect of a disposable particulate respirator containing charcoal fiber (called a “charcoal mask”) and a charcoal granule cartridge‐mask (called a “gas mask”) in the real working conditions. Methods: Approximately 100 male and female workers from about 10 small industries were subjected to the studies first in winter and second in summer. Individual exposure to styrene was monitored with a passive sampler during work time, and end‐shift‐u...
Study objective-The aim was to determine theactualprevalence ofliver disease andtoinvestigate the... more Study objective-The aim was to determine theactualprevalence ofliver disease andtoinvestigate thecontribution ofvariousriskfactors to liverdisease amongthepopulation inamethylmercury polluted area. Design-Thestudywas a population basedcrosssectional massscreening survey.A case-control studywasdesigned to estimate theroleofvarious riskfactors for liver diseases. Setting-The studywas confinedto a smallruraltown10km northofMinamata City. Subjects-1406 personsaged50to69years were examined (78-3%of the total population ofthisageinthelocality). Measurementsand main resultsMeasurements ofliver disease weremade onthebasis ofhaematological, physical, and ultrasonographic examinations. Data on liverriskfactors werecollected byquestionnaire, and by measurementofbody height, weight(obesity), andhepatitis B surfaceantigen(HBsAg).Theprevalence rateofliver tumourwas05% inmales, liver cirrhosis wasfoundin0-5%ofmalesand 0-1%offemales, andhepatitis wasseenin 5-4%of malesand 1P0% of females. Frequency...
International Journal of Dermatology, 2002
Background Arsenic contamination in groundwater affects 35 million people in Bangladesh, but the ... more Background Arsenic contamination in groundwater affects 35 million people in Bangladesh, but the prevalence of arsenic contamination in local communities remains to be clarified. As skin manifestations are sensitive markers of arsenicosis, we examined the skin of adults and adolescents in two villages to elucidate the severity of arsenicosis. Methods Five hundred and sixty-one villagers were randomly selected for the evaluation of their skin. Three indicators, i.e. keratosis on the soles, keratosis on the palms, and melanosis and hypopigmentation on the trunk, were quantified for analysis. Results More than 50% of the villagers showed some skin manifestations due to arsenicosis. Keratosis on the soles was the most sensitive marker for the detection of arsenicosis at an early stage. Interestingly, the skin manifestations were more severe in males than in females. There was no correlation between the age and the severity of skin manifestations. Conclusions The prevalence of arsenicosis was quite high and males were more vulnerable to arsenic contamination. Using skin manifestations, especially keratosis on the soles, as useful markers to detect and evaluate arsenicosis, it is clear that there is an urgent need to assess the exact prevalence and severity of arsenicosis in the population of Bangladesh in order to take measures to treat and control this problem.