[Show abstract][Hide abstract] ABSTRACT: 特集号 油症とPCB及びダイオキシン関連化合物 研究報告第22集 責任編集者 古江増隆 The Twenty-second Reports of the Study on Yusho―PCBs and Dioxin-Related Compounds―Guest Editor Masutaka Furue The half-life of 2,3,4,7,8-penta-chlorodibenzofuran (PeCDF) in the Yusho patients has been reported to be approximately seven years. In the present study, we estimated the half-life of PeCDF using data from the medical check-ups of more than 300 Yusho patients. We performed linear regression analysis with a binary logarithm of PeCDF blood level in Yusho patients as the dependent variable, and the measurement year as the independent variable. Our results showed that there were many patients who had shown no reduction of their blood PeCDF level for several years. This result contradicts the previously reported half-life period. Therefore, we believe that a more complicated excretion model needs to be established to explain the discrepancy we found. We hypothesized that there might be two mechanisms of PeCDF assimilation in human digestive tract. In the present study, we also used our hypothesis to simulate PeCDF excretion in Yusho patients.
[Show abstract][Hide abstract] ABSTRACT: 特集号 油症とPCB及びダイオキシン関連化合物 研究報告 第21集 ［Background］Kanemi Yusho is the name given to a 1968 food poisoning incident resulting from the ingestion of PCB contaminated rice bran oil that had been used as a heating medium. At the time, victims presented with mainly cutaneous manifestations and various other symptoms such as of the eyes and teeth,general fatigue,headaches,and paresthesia of the extremities. The characteristic symptoms then resolved with time. Yusho patients have been followed from immediately after the incident. Blood levels of dioxins such as PeCDF have been measured for those who wishing to since 2001.［Subjects and methods］The presence or absence of relationships between blood PeCDF level and various examination items/symptoms was investigated in 359 subjects whose blood levels of PCB-related chemical compounds such as PeCDF were measured in the Yusho related examinations between 2001 and 2003. Characteristic symptoms were also compared with the results of examinations done 15years previously. ［Results and discussion］The average blood 2,3,4,7,8-PeCDF level in designated Yusho patients was 177.50 pg/g lipids ; showing a markedly higher value than that of the normal control group (15.2 pg/g lipids). As well,the blood PeCDF level was related to PCB level,hexachlorobiphenyl level,urinary sugar,erythrocyte sedimetation rate (ESR)(2-hour),thymol and Na. There were also relationships with cutaneous findings (acneiform eruption and comedones),mucosal findings (oral pigmentation), constipation, numbness in the extremities, body weight loss, and abnormal abdominal ultrasonography. Symptoms seen in the skin and eyes in 2001 and 2003 had decreased compared with those in seen 1988.However,PCB and blood PeCDF levels remained high. Patients are continuing to present with mucosal and subjective symptoms as chronic conditions.
[Show abstract][Hide abstract] ABSTRACT: 特集号 油症とPCB及びダイオキシン関連化合物 研究報告第22集 責任編集者 古江増隆 The Twenty-second Reports of the Study on Yusho―PCBs and Dioxin-Related Compounds―Guest Editor Masutaka Furue [Background] Since 1968, when the Yusho poisoning incident occurred, annual physical, dermatological, dental, and ophthalmological and laboratory examinations, collectively called Yusho health checks, have been conducted for Yusho patients. The Yusho incident was a health hazard caused by intake of rice-bran oil contaminated with PCB and PeCDF ; therefore, since 2001 the levels of dioxins such as PeCDF in the blood have been measured in applicants. Here, we investigated correlations among findings from various medical examinations and those between those findings and PeCDF, PCB, and PCQ. [Patients and Methods] Subjects were Yusho patients who underwent Yusho annual health checks and had their levels of PeCDF measured between 2001 and 2004. The results of 4 years of health checks of those who underwent the health checks for 2 years or longer were aggregated to extract representative inspection items by principal component analysis. We also investigated the presence or absence of correlations among these items and PeCDF, PCB, and PCQ levels in blood. [Results] Using 49 variables extracted by principal component analysis as objective variables, we determined that there were correlations between the following combinations : arthralgia, A/G ratio and PeCDF level, ophthalmological symptoms such as excessive eye discharge and PCB level, and total cholesterol, inferior gingival pigmentation and PCQ level.
[Show abstract][Hide abstract] ABSTRACT: 特集号 油症とPCB及びダイオキシン関連化合物 研究報告 第21集 ［Background］Kanemi Yusho was a food poisoning incident caused by rice bran oil that occurred in western Japan, particularly in northern Kyushu, in 1968. It is difficult to determine the symptoms in patients after many years since the occurrence. Techniques for measuring blood dioxins have advanced recently. More accurate data measurement has now become possible, and techniques for mass data analysis, such as data mining, have also advanced. It has also become possible to find unknown characteristics,even in an object group with elusive characteristics, by checking all the combinations in all the patients. ［Aim］There are already several reports on the incidence of symptoms in Yusho patients. These reports are limited to symptoms in a single period,and there has been no analysis taking into account the time that has elapsed. Here,we evaluated the relationship between recent and past symptoms and 2,3,4,7,8-penta-chlorodibenzofuran (PeCDF) levels in the same subject patient, in order to demonstrate the correlation between PeCDF levels and symptoms at a time point close to the incident. ［Methods］Subjects were examined for symptoms of Yusho and had blood PeCDF levels measured, both recently and in the past. Combinations were extracted using association analysis of data mining technique for comparison, which had strong correlations between the presence or absence of symptoms in the medical examination, tests including blood test, dermatological examination, dental examination and ophthalmologic examination in recent years (2001-2004)and the blood PeCDF levels and those between the presence or absence of past (1986- 1989) symptoms and recent blood PeCDF levels. ［Results］Subjects with higher PeCDF levels were more likely to present with pigmentation, a symptom included in the diagnostic criteria for Yusho. Pigmentation was a commonly found symptom in the past. Past pigmentation was a common symptom in the present. ［Discussion］PeCDF levels were measured recently and therefore should not be compared directly with past symptoms. However,among the symptoms included in the diagnostic criteria, past symptoms tended to have a stronger relationship with PeCDF levels than did recent symptoms. We suggest that the present PeCDF level is strongly related to the past symptoms since the present PeCDF level is correlated with the past PeCDF level due to constant emission rate. More specifically,if the past PeCDF level is strongly related to the past symptoms,it can indirectly be concluded that the present PeCDF level is also strongly related to the past symptoms. Thus, the present PeCDF level cannot be related to the past symptoms directly but can indirectly. ［Conclusions］Combining recent and past symptoms further demonstrated that clinical symptoms are strongly related to PeCDF toxicity. This may have resulted from the increase in symptoms with aging, however, it was demonstrated that the symptoms of each patient were relieved and become obscure.