Nippon Eiseigaku Zasshi (Japanese Journal of Hygiene)
Online ISSN : 1882-6482
Print ISSN : 0021-5082
ISSN-L : 0021-5082
Volume 62, Issue 3
Displaying 1-3 of 3 articles from this issue
Reviews
  • Hiroshi SATOH
    2007 Volume 62 Issue 3 Pages 881-887
    Published: May 15, 2007
    Released on J-STAGE: May 16, 2008
    JOURNAL FREE ACCESS
    I would like to express sincere thanks to all the people involved in awarding the 2005 Congress Award. It is a great honor to be given the prize. I have been interested in mercury toxicology since I was a graduate student and mercury toxicology has been my main subject of focus for 30 years. I am proud to continue the research in this field. In this presentation I would like to summarize some of my research works and to talk anecdotes related to the research works. Soon after I became involved in this research field, I came across “behavioral teratology”, which is a novel field of study whose focus is understanding the postnatal consequences of exposure to harmful agents in utero. Spyker and her colleagues clearly showed postnatal behavioral deviations in mouse offspring exposed to a low dose of methylmercury prenatally. In various animal experiments, I elucidated the subtle consequences that appear postnatally. I found that these consequences are modified by many factors such as selenium status, PCBs, and heat, because the degree of exposure to produce these consequences can be extremely small. These experiments simulate actual human life and the results will be useful to assess the risk of methylmercury exposure through fish consumption in the human population, since fish eating populations are exposed to these factors at a low dose. Recently, cohort studies elucidating the possible effects of prenatal exposure to environmental pollutants in the postnatal period have been established and ongoing. When a conclusion is drawn, it is expected to serve as basic information that is useful for the risk assessment of methylmercury and other environmental pollutants. This will give great gratification to scientists in environmental health and preventive medicine.
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  • Hyogo HORIGUCHI
    2007 Volume 62 Issue 3 Pages 888-904
    Published: May 15, 2007
    Released on J-STAGE: May 16, 2008
    JOURNAL FREE ACCESS
    Anemia is commonly induced by chronic cadmium (Cd) intoxication. Three main factors are involved in the development of Cd-induced anemia: hemolytic, iron-deficiency, and renal. Intravascular hemolysis can occur at the early stage of Cd exposure owing to the direct damaging effect on erythrocytes. In addition, Cd that accumulates in erythrocytes affects membrane cytoskeletons and decreases cell deformability, and these cells are then trapped and destroyed in the spleen. Iron deficiency can be detected in animals after an oral exposure to Cd, which competes with iron for absorption in the intestines, leading to anemia. However, an increase in body iron content along with anemia is often observed in cases of parenteral exposure or itai-itai disease. Therefore, it is estimated that Cd disrupts the efficient usage of iron in hemoglobin synthesis in the body. Renal anemia is observed during the very last phase of chronic, severe Cd intoxication, such as itai-itai disease, showing a decrease in the production of erythropoietin from renal tubular cells. Because the renal anemia is based on the same pathophysiology as Cd-induced osteomalacia, which is derived from the disturbance of mineral metabolism due to renal tubular dysfunction, it is reasonable to include renal anemia in the criteria for the diagnosis of itai-itai disease. Hemodilution could also contribute to the development of Cd-induced anemia. Bone marrow hypoplasia or the inhibition of heme synthesis might only be involved in Cd-induced anemia in severe cases of Cd intoxication.
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Original
  • Xiao Jie LIU, Mineshi SAKAMOTO, Takeko KATO, Miwako OKAMOTO, Kimiyoshi ...
    2007 Volume 62 Issue 3 Pages 905-910
    Published: May 15, 2007
    Released on J-STAGE: May 16, 2008
    JOURNAL FREE ACCESS
    Objectives: The main purposes of this study are to compare the current statuses and activities of daily living (ADL) scores with the same parameters 15 years ago in fetal-type Minamata disease patients and to identify the communication disorders in these patients.
    Methods: An interview survey was conducted on 31 fetal-type Minamata disease patients mainly in 2002 concerning family structure, present status of care, their demand for care, communication status, and ADLs. Changes in ADLs during the past 15 years were also studied in 22 of the patients.
    Results: Their mean ages were 45.5±3.5 (n=20) for males, and 46.1±1.9 (n=11) for females. The average numbers of family of the patients was 2, and 15 patients lived alone. An analysis of ADLs showed that about 50% of the patients could not walk or take a bath, and 30 to 40% of the patients could not eat, excrete, change their clothes, or wash their face alone. Approximately 80% of the patients could understand daily conversation to some degree. However, their ability to express their demands and thoughts, put an idea into action, remember events, and live like ordinary people were significantly worse than their ability to understand daily conversation. The changes in the ADLs of the 22 patients were not significant for the past 15 years. However, two patients showed a rapid decrease for ADL of movement and 2 other patients died after an interview before 50 years of age.
    Conclusions: Appropriate care in daily living is an important issue for fetal-type Minamata disease patients. Further, the individual health care of such patients is an urgent issue and can prevent their health from rapidly deteriorating.
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