Acute paraquat poisoning seems to be very complex because many possible mechanisms of paraquat cytotoxicity have been reported. Some may not be the cause of paraquat poisoning but the result or an accompanying phenomenon of paraquat action. The mechanism critical for cell damage is still unknown. Paraquat poisoning is probably a combination of several paraquat actions. Arguing which mechanism is more critical may not be important, and these clarified mechanisms should be connected and utilized in the development of treatment for paraquat poisoning. Many people still die of pulmonary fibrosis after paraquat exposure. The next target of study will be to verify the mechanism of pulmonary fibrosis by paraquat on the basis of the outcome of studies such as this review.

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Colorectal cancer is the second most common malignancy in the Western world including the United Sates. In recent years there is a strong upward trend in colon cancer risk in Japan mainly due to Americanization of Japanese food habits. Several epidemiological studies point to a strong association between nutrient composition of the diet and cancer of the colon. The role of types of dietary fat, especially saturated fats of animal origin, n-6- and n-3-rich polyunsaturated fatty acids (PUFAs) in the etiology of colorectal cancer has become increasingly apparent. Epidemiological studies indicate a positive association between the dietary intake of saturated fat and/or animal fat and colon cancer risk and an inverse relationship between the intake of fish and fish oil rich in n-3 PUFAs and colon cancer development. Although the evidence from case-control studies and international correlational studies is not totally consistent, these inconsistencies may have arisen, at least in part, from methodological limitations. Animal model studies have unequivocally provided evidence that the colon tumor-promoting effect of dietary fat depends on its fatty acid composition and that high dietary n-3 PUFAs lacks colon tumor-promoting effect as compared to diets high in n-6 PUFAs or saturated fats. Diets rich in n-3 PUFAs inhibit colon carcinogenesis through the modulation of colonic ras-p21, cyclooxygenase-2, and inducible nitric oxide synthase activities and apoptosis. Gene expression analysis using DNA microarrays indicates that n-3 fatty acid, docosahexaenoic acid activates cyclin-dependent kinase inhibitors such as p21, p27, p57 and p19 and inactivates antiapoptotic Bcl-2 family of genes, and prostaglandin family of genes. These results suggest that decreasing the intake of n-6 PUFAs and saturated fats and increasing that of n-3 PUFAs, particularly eicosapentaenoic acid and docosahexaenoic acid has the potential to be a major component of colon cancer control.

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In 1998, a movie entitled “A Civil Action” was released. The movie described the Woburn case, begun in 1982 and concluded in 1990, one of the most famous cases of trichloroethylene pollution. In a small town near Boston, twelve children died of leukemia, which seemed attributable to trichloroethylene contamination of the drinking water. The victims, however, could not win the case, since evidence that the identified chemicals could cause leukemia and other human illnesses was rather sketchy. There have been many cases of trichloroethylene pollution in industrial nations including Japan, therefore, we reconsidered the missing link. Our conclusion is that the disease occurred not by a direct effect of the chemical hazard on biological macromolecules but by an indirect effect through the physiological system such as signal transduction and transcriptional regulation. In 1984, we reported a marked reduction in the regulatory heme pool by trichloroethylene exposure, however, the biological significance was not well understood. Recently, we found that the DNA binding activity of Bach1, a negative regulator of genes, is controlled by heme, the regulation of which seems to explain how leukemia develops. The heterodimer of Bach1 with MafK recognizes Maf recognition elements (MAREs) competing with the erythroid type positive regulator, a complex of NF-E2 with MafK. Bach1/MafK occupies MAREs under lower heme conditions, whereas MAREs are open to NF-E2/MafK along with increasing heme concentration. Since the NF-E2/MafK function is closely related to normal erythroid differentiation, of which disorders such as sideroblastic anemia are often related to neoplasia; i.e., a clonal disorder that can progress to leukemia. Thus, a marked decline in regulatory heme by trichloroethylene intoxication could be one of the pathways to leukemia.

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The aim of this study was to investigate the longitudinal effect of mobility and daily activity, in the form of exercise and everyday activities, on the bones of 102 elderly female nursing home residents who had physical disabilities as well as marked postmenopausal bone loss, using calcaneal ultrasound apparatus for bone evaluation.
Of the 102 subjects initially measured, 74 (mean age, 83.5±6.55 years; range, 64−99 years) could be measured again approximately one year later. The osteo sono-assessment index (OSI) in this study was determined using an ultrasound bone evaluation device. This device measures the speed of sound (SOS) and transmission index (TI) as ultrasound passes through the calcaneus. The OSI is calculated by computer analysis (OSI=TI×SOS²). For mobility, the OSI decreased significantly by an average of 1.8% after 11.8 months in all of the residents who were using a wheelchair (n=41, p<0.01). In contrast, the OSI rose significantly by a mean of 1.9% in the ambulatory group (n=33, p<0.01).
The OSI increased significantly in residents who exercised every day, were out of bed for at least seven hours per day, and walked on a regular basis, suggesting that exercise, mainly in the form of walking, may increase the calcaneal OSI.

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Objective: This study examined the levels of serum protein fractionation, immunoglobulin (Ig) and antistreptolysin O (ASO) of people (91 males and 84 females aged 10−68 years) living in the Terai region of southern Nepal, as there had previously been no information available about them.
Methods: Blood samples were collected early in the morning after overnight fasting. Serum protein fractionation was carried out by cellulose-acetate electrophoresis. IgG, IgA, IgM and ASO were measured by immuno-turbidimetry with clinical kits.
Results: The mean proportion of albumin (Alb) was rather low due to increased globulin (Glb). The Alb level of males was significantly higher than that of females, while the male γ-Glb level was significantly lower than that of females. The mean values of IgG, IgM and ASO for males were lower than those values for females, although the difference was significant only for the IgM value. The mean values of IgM for female age groups of 30-39 years or less were significantly higher than those for the corresponding male age groups. Age correlated positively with IgA, and negatively with ASO in both sexes. γ-Glb and IgG correlated significantly with TP, Alb, α₁-Glb and IgA in both sexes. ASO correlated with β-Glb and IgA in males, and with γ-Glb and IgG in females.
Conclusions: The fact that the level of γ-Glb, a major component of serum globulin, was high suggested exposure to a highly bacterial and viral environment. These results point to the need to prevent infectious diseases as well as improve their nutritional status, especially for children and young adults.

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Objectives: To evaluate the physical strength, cerebral function, and mental health conditions in elderly persons, and to examine the correlation between these functions.
Methods: The subjects were 151 independent-living elderly Japanese women, mean age 70 +/− 5 years (+/− SD; range, 60 to 80 years), with normal abilities in daily life. The health check-up was conducted from April to May 1997. Physical strength was estimated by measuring seven activities. Cerebral functions were assessed by six sub-tests of the General Aptitude Test Battery (GATB). Their mental health status was measured by four sub-scales of the General Health Questionnaire (GHQ)-28.
Results: The physical strength and almost all of the cerebral functions decreased with age. Social dysfunction and severe depression on the GHQ sub-scales also worsened with age. Physical strength was strongly correlated with cerebral functions after adjusting for the confounding effect of aging. There were also interrelations between physical strength and mental health.
Conclusions: This study provided important information on the correlation between physical and mental status in elderly women. Future longitudinal studies with the intervention of physical training are required to determine whether a causal relationship exists between these factors.

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Objectives: To elucidate the association between genetic polymorphisms of CYP2A6 and CYP2E1 and urothelial cancer susceptibility.
Methods: A total of 137 Japanese patients with urothelial cancer and 217 Japanese healthy controls, frequency-matched for age and gender, were selected. The polymorphisms of CYP2A6 and CYP2E1 were analyzed by PCR-RFLP, and cigarette smoking histories were obtained through interviews.
Results: The frequency of CYP2A6 homozygote deletion genotype was 2.9% in the patients, compared with 3.2% in the controls (OR=0.84, 95% CI 0.24−2.96). The frequencies of CYP2E1 C1/c2 and C2/c2 were 27.7% and 4.4% in the patients, compared with 35.5% and 6.0% in the controls (OR=0.68, 95% CI 0.42 −1.09, OR=0.67, 95% CI 0.24−1.84, respectively). No statistically significant differences were observed when the CYP2A6 homozygote deletion genotype and the CYP2E1 genotypes were examined relative to smoking status.
Conclusions: Our data indicate that neither a relationship between genetically impaired nitrosamine metabolism and tobacco-smoking consumption, nor urothelial cancer risk related to the CYP2A6 deletion genotype and CYP2E1 Rsa I genotype was found in Japanese population.

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In the first part of the paper, the main achievements and experience of disease control and prevention in China during last 50 years are described. Infectious diseases and parasitosis have been successfully controlled and prevented and people’s health enhanced owing to the establishment of an effective system of public health, the launch of a campaign called “Patriotic Public Health”, immunization planning, and the improvement of economic and environmental conditions. In the second part, the challenges to public health in China are presented. The threat from old and emerging infectious diseases, especially sexually transmitted diseases, a sustained increase in the prevalence of chronic non-infectious diseases (cardiovascular diseases, tumors and diseases of the respiratory system), environmental problems and the health problems of aging are discussed. Finally, strategies for disease control and prevention in the new century is suggested.

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They should be corrected as underlined. Wrong:7, 3
Right:10, 9

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