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In this paper, we propose two simplified methods for foundation input motion of embedded foundation. The first is the least squares method based on the geometrical relationship between each part of the foundation and ground motion. The second is the weighted average method which uses the simplified evaluation for the driving force and impedance function of embedded foundation by combining the impedance function of spread foundation and ground motion. The accuracy and validity of the proposed methods are shown by comparing the results with those obtained from an existing numerical method.

Background Environmental exposure to some persistent organic pollutants has been reported to be associated with a metabolic syndrome in the U.S. population. Objectives We evaluated the associations of body burden levels of dioxins and related compounds with the prevalence of metabolic syndrome among the general population in Japan. Methods We conducted a cross-sectional study with 1,374 participants not occupationally exposed to these pollutants, living throughout Japan during 2002–2006. In fasting blood samples, we measured biochemical factors and determined lipid-adjusted concentrations of 10 polychlorinated dibenzo-p-dioxins (PCDDs), 7 polychlorinated dibenzofurans (PCDFs), and 12 dioxin-like poly-chlorinated biphenyls (DL-PCBs) all of which have toxic equivalency factors. We also performed a questionnaire survey. Results The toxic equivalents (TEQs) of PCDDs, PCDFs, and DL-PCBs and total TEQs had significant adjusted associations with metabolic syndrome, whether or not we excluded diabetic subjects. By analyzing each component of metabolic syndrome separately, the DL-PCB TEQs and total TEQs were associated with all components, and the odds ratios (ORs) in the highest quartile of DL-PCB TEQs in four of the five components were higher than those for PCDDs or PCDFs. We also found congener-specific associations with metabolic syndrome; in particular, the highest quartiles of PCB-126 and PCB-105 had adjusted ORs of 9.1 and 7.3, respectively. Conclusions These results suggest that body burden levels of dioxins and related compounds, particularly those of DL-PCBs, are associated with metabolic syndrome. Of the components, high blood pressure, elevated triglycerides, and glucose intolerance were most closely associated with these pollutants.

Objective The objective was to grasp the recent body burden levels of polychlorinated dibenzo- p -dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (DL-PCBs) and to investigate their determinants among general inhabitants in Japan. Methods This study was performed on 1374 participants aged 15–73 years, who were not occupational exposure to PCDDs/PCDFs and DL-PCBs, living widely in 75 different residential areas of 25 prefectures in Japan. Seven PCDDs, ten PCDFs, twelve DL-PCBs, which are assigned a toxicity equivalent factor, and biochemical factors were determined in fasting blood. A questionnaire survey on life-style was also performed. Results The median of total toxicity equivalent (TEQ) was 20 pg TEQ/g lipid. The TEQs of PCDDs/PCDFs, DL-PCBs and total TEQ increased with age. The intake frequency of fish-and-shellfish was positively associated with the TEQ of DL-PCBs in both sexes. Current smoking was negatively related to the TEQ of DL-PCBs in male subjects but not in female subjects. Feeding status was significantly related to the TEQs of PCDDs/PCDFs, DL-PCBs and total TEQ, being lowest in breast feeding and highest in never and bottle feeding. According to the results of subgroup analysis, parity was not associated with the TEQs. Conclusions The fish-and-shellfish consumption may contribute to the accumulation of DL-PCBs, and smoking may induce some biological action for the elimination of DL-PCBs from the human body. Breast feeding is considered to be one of the major excretory pathways of PCDDs/PCDFs and DL-PCBs in women, while parity may not largely contribute to the elimination of these pollutants.

Cadmium chloride can induce DNA fragmentation, a biochemical characteristics of apoptosis in renal epithelial LLC-PK1 cells. Studies of cadmium cytotoxicity demonstrated that cadmium activates c-myc transcription. In this study, we investigated whether c-myc is a necessary component of cadmium-induced apoptosis. By kinetic analysis, transient activation of c-myc transcript by cadmium occurred before DNA fragmentation was induced by the metal, indicating an apparent correlation between induction of c-myc mRNA and promotion of apoptosis. However, even when using actinomycin D to block transcriptional activation of c-myc, or antisense oligodeoxynucleotide complementary to c-myc to block translation of c-myc, cadmium could still induce apoptosis. Thus, our data show that cadmium elicits apoptosis by a mechanism other than regulation of c-myc expression: transcriptional activation of c-myc during apoptosis is not always involved in the cell-death events.

Lead concentration and isotopic composition of prehistoric (middle and latest Jomon era, 2000–4500 BP, n =6), historic ( Edo era, 130–400 BP, n =10), and contemporary (died in 1987–88, n =15) Japanese bones, and deciduous teeth from contemporary Japanese children born during 1985–88 ( n =17) were analyzed by inductively coupled plasma mass spectrometry. Lead concentration was lowest in Jomon bones and was higher in rural Edo , contemporary, and urban Edo , in that order. Elevated Pb concentration in historic Edo people, as reported previously, was reconfirmed. The average isotopic ratios ( 207 Pb/ 206 Pb and 208 Pb/ 206 Pb) in excavated (prehistoric and historic) bones, contemporary bones, and deciduous teeth were different from each other. The contemporary bones had the least radiogenic composition (mean 207 Pb/ 206 Pb: 0.879; mean 208 Pb/ 206 Pb: 2.126) while the excavated bones the most (0.848; 2.098), and teeth intermediate (0.866; 2.111). The comparison with the literature data of isotopic compositions of environmental samples showed that the isotopic composition of the excavated bones was within the range of Japanese ores, rocks and soils, indicating the absence of foreign Pb sources in preindustrialized Japan. That of the contemporary bones was closer to the average gasoline Pb, the use of which had been banned in the late 1970s, than to the Pb in airborne particulate matter or refuse incineration ash of 1980s. The average Pb isotopic ratios in the deciduous teeth was close to the isotopic ratios of Pb in airborne particulate matter and refuse incineration ash. These data indicated that the contemporary Japanese population was exposed to foreign Pb which had different isotopic composition from domestic Pb. Exposure to Pb of foreign origin was particularly evidently recorded in people born before the leaded gasoline ban. The history of human Pb contamination in Japan is discussed based on the present results and other previously published data.

The present study was conducted to clarify the acute effect of tris(2-chloroethyl)phosphate (TRCP), an organophosphate flame-retardant, on spontaneous ambulatory activity (AA) in male ICR mice and to examine the neurochemical mechanism of this effect. Single dose administration of 200 mg/kg ip of TRCP increased AA in ICR mice. Neither the nicotinic cholinergic antagonist mecamylamine (MA) nor the muscarinic cholinergic antagonist scopolamine (SCP) affected the AA response to TRCP. On the other hand, the benzodiazepine agonist diazepam (DZ), the GABAAagonist muscimol (MUS) and the GABABagonistbaclofen (BAC) all attenuated the effect of TRCP. DZ and MUS blocked the increase of AA within the first 10 min after administration of TRCP. These drugs did not attenuate the AA-increasing effect of SCP, suggesting that the mechanism of TRCP action is distinct from that of SCP. MUS and BAC did, but DZ did not, inhibit the AA increasing effect of the dopaminergic agonist apomorphine (APO), suggesting that dopamine is involved in the control of AA, and that GABA can affect AA through interaction with dopaminergic neurons. These results suggest that TRCP acts as a GABA antagonist and not as a cholinergic agonist, and that TRCP increases AA in ICR mice through a GABAergic mechanism.

To examine whether abnormal migration of granular cells in the external granule layer during cerebellar development is in part of the etiology of fetal Minamata disease, organotypic culture of rat cerebellar slice was established. Migration of external granule cells pulse-labeled with bromodeoxyuridine (BrdU) toward the internal granular layer was inhibited by the presence of methylmercury (0–10 μ M) in a dose-dependent manner. Nuclear condensation and DNA fragmentation visualized by the indirect immunofluorescence method with anti-BrdU antibody and the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) method indicated that a large fraction of cells in the external granular layer underwent apoptotic death in the slices treated with 10 μ M methylmercury. Thus, methylmercury inhibits the migration of cerebellar granule cells in a model system for neural development. The impaired migration was a possible cause of the apoptotic death of external granule cells.

Nutritional selenium (Se) status in an Andean population living at high altitude (4000 m above sea level) was examined using dietary Se (DSe) intake. Mean (±SD) DSe intake was 47.7±16 μg/day for adult males (19 years old and above), and 36.6±13 μg/day for adult females. Two-thirds of the subjects were found to consume less Se than the U.S. Recommended Dietary Allowance values. The DSe levels among the subjects examined were marginally lower compared to values reported from other areas of the world. Their blood Se (whole blood Se, erythrocyte Se and serum Se), however, appeared to be maintained at a relatively high level with respect to the marginally lower DSe intake.

The carbon and nitrogen stable isotopic composition of the scalp hair and diet of Gidra-speaking people in four villages in Papua New Guinea is presented. The isotopic composition of hair was measured, while that of the diet was estimated from food consumption survey data and the measured isotopic composition and protein and carbohydrate contents of food items. The average isotopic ratios of the hair samples and of the diet varied among the four study villages, which were selected because of their diverse ecological settings. Comparison was made between hair and calculated dietary isotopic compositions. Two of the four diet-hair enrichment values obtained for 13C (+1.8 and 2.2%‰) were similar to those previously reported (1.4–2.0%‰), but the other two values (3.7 and 4.8%) were greater than in earlier reports. 15N enrichment was systematically greater (by 1%‰) than reported values (∼4.3%‰) except for one village, where a much greater enrichment (6.9%‰) was found. The factors potentially relevant to these deviations are discussed. Possible errors in estimating the dietary isotopic composition and minor modifications of dietary habits revealed by food consumption surveys could explain most of the discrepancies. However, the great enrichment of 15N found in one of the villages remains unexplained. © 1996 Wiley-Liss, Inc.

Hair and mercury concentrations of 134 fish-eating subjects in the Lake Murray area and 13 non-fish-eating subjects in the upper-Strickland area, Papua New Guinea, were studied. Hair mercury levels among the subjects in the Lake Murray area (mean = 21.9 micrograms/g, range = 3.7-71.9 micrograms/g) and urinary mercury levels (mean = 7.6 micrograms/g creatinine, range = 1.4-25.6 micrograms/g creatinine) were markedly higher than levels found in subjects from the upper-Strickland area (mean hair mercury = 0.75 micrograms/g, mean urinary mercury = 0.48 micrograms/g creatinine). Mercury intake of the fish eaters, estimated from mercury concentrations found in fish and from the observed amounts of fish consumed, was approximately 73 micrograms/d. Hair and urinary mercury concentrations were correlated significantly (r = .59), indicating that urinary mercury excretion was elevated because fish consumption was very high.

Selenium (Se) levels in blood (whole blood, erythrocytes and serum) and blood glutathione peroxidase (GSH-Px) activity were investigated in people living at high altitude in Bolivia (4,000 m above sea level). These parameters were compared to those of people living at low altitude (300 m above sea level). The Se levels in whole blood of the high-altitude subjects did not differ significantly from those of the low-altitude subjects. However, the Se levels in erythrocytes were significantly lower in the high-altitude subjects than in the low-altitude subjects, whereas serum Se levels were higher in the high-altitude subjects than in the low-altitude subjects. GSH-Px activity (Unit/g Hb) was significantly lower in the high-altitude subjects than in the low-altitude subjects. The mean corpuscular Hb concentration (MCHC), an indicator of the age of erythrocytes, in the high-altitude subjects was significantly higher than in the low-altitude subjects. These results show that the GSH-Px activity in the blood of the high-altitude subjects is relatively low. This may be due to their aged erythrocytes and/or to relatively low Se intake in the high-altitude population compared with low-altitude population.

The hair-organ relationship of mercury concentration was investigated in 46 autopsy samples in Tokyo, Japan. Hair mercury levels were highly significantly correlated with organ Hg levels in the cerebrum, cerebellum, heart, spleen, liver, kidney cortex, and kidney medulla, when the total mercury or methyl mercury value in the organ was compared with the hair total mercury or organic mercury, respectively. When the inorganic mercury value was tested, significant correlations remained, with weaker coefficients in all the organs but the spleen. Stepwise multiple regression analysis evidenced that the hair organic mercury value was the major explanatory variable for the organ total mercury or organ methyl mercury value in all the organs. To explain the organ inorganic mercury value, the hair organic mercury value was the major variable for the cerebrum and kidney (both cortex and medulla), the hair inorganic mercury value was the major variable for the cerebellum and heart, and the hair phosphorous and hair organic mercury were the major variables for the liver; no explanatory variable existed for the spleen. Auxiliary explanatory variables accounted for the organ total mercury and inorganic mercury levels, among which the hair selenium value was conspicuous with negative regression coefficients.

Serum concentrations of 11 elements (Na, Mg, P, S, K, Ca, Fe, Cu, Zn, Sr and Se) in the adult populations of the Gidra in lowland Papua New Guinea were measured. The marked characteristic of the element profile in the Gidra was higher Cu and slightly lower Zn concentrations than those in developed countries. Zinc nutriture of the Gidra was judged to be marginally deficient, presumably because of their high intake of crude fiber and Fe, which are known to inhibit Zn absorption, and the decreased Zn absorption might have increased Cu absorption. Inter‐village variation in serum element concentrations was large for Fe and Sr. The difference in the serum Fe levels is partly explained by the difference in the prevalence of malarial infection in addition to the different intake levels. For other elements (Na, Mg, P, S, K, Ca and Se), the difference among the villages was small, and those levels in the Gidra fell in the range reported in developed countries.

Forthcoming global environmental changes threaten to endanger human survival through direct and indirect influences. In this paper, the contemporary world food supply situation and resultant nutritional status was first reviewed on by country and region. When compared with the nutritional energy requirement, countries with an inadequate food supply were concentrated in the developing world, in particular in some parts of Africa. The life expectancy at birth is clearly shorter in such countries, and peoples of African countries with an inadequate food supply have shorter life expectancies than other countries with a similar inadequacy.Global warming is likely to decrease food production in some parts of the world. According to the present estimation using various methods, a future crisis of food production may occur in African countries which are at present most vulnerable to food shortages, as well as in countries which are presently food exporters. Thus, a future crisis of human health conditions caused by the imbalance of food production and trade may be least avoidable in the region of present predicament.

成人女子8名を対象に9週にわたる期間の中で1人当り平均28日の食物摂取調査を行い, 亜鉛摂取量を計算により推定した。また同調査開始直後と終了の翌日に採血を行い血漿亜鉛濃度を原子吸光分析法により測定した。1) 食物摂取調査開始時の血漿亜鉛濃度は0.74±0.10μg/ml, 終了時0.78±0.13μg/mlであった。2) 1人1日当りの平均摂取量はエネルギー1, 685±120kcal, タンパク質58.7±7.4gであり, 推定亜鉛摂取量は6.3±0.7mgであった。また体重1kg当りの亜鉛摂取量は0.114±0.019mgであった。3) 平均28日 (23～32日) での体重1kg当りの亜鉛摂取量の変動係数の平均は34.1%であった。4) 体重1kg当りの亜鉛摂取量と食物摂取調査終了時の血漿亜鉛濃度との間に有意な正の相関が認められた (r=0.793, p

がん診断前に採血された血清試料について,セレン及び亜鉛濃度と,その後の発がんリスクとの関連を疫学的に明らかにするため,セリウムを内標準とする機器中性子放射化分析法(INAA)による,少量(0.2ml以下)のヒト血清中のセレンと亜鉛の同時定量法を確立した.方法の概要は以下のとおりである.一定量のセリウム標準溶液を添加した血清試料と比較標準溶液を合成石英管にとり,試料は凍結乾燥後減圧封人し,比較標準はそのまま減圧封人し,JRR-2(熱中性子束2.2×1013n cm-2s-1以上)で265.5時間照射をする.約1か月間冷却後,石英管表面をフッ化水素酸で約5μmエッチングし,Ge(Li)検出器で一定時間(4000秒以下)γ線スペクトルを測定する.試料及び比較標準試料の141Ceに対する75Seと65ZRのγ線ピーク面積比から試料中のセレン及び亜鉛含量を算出する.同一試料14個による定量値のRSDは3.0%(Se)及び5.2%(Zn)であった.本法による血清試料及びNISTBovinc Liver標準試料(SRM1577,SRMI577a)の定量値は,NISTの保証値を含む他の方法による定量値と,極めてよく一致することが確認された.

A woman ingested a dose of sublimate (approximately 0.9 g) in an attempted suicide. She survived and recovered in response to a combination of therapies including chelate (BAL) therapy, plasma exchange, haemodialysis and peritoneal dialysis. Serum inorganic mercury concentration, urinary inorganic mercury excretion and hair inorganic and organic mercury and selenium concentrations, along the length from the scalp to the distal part, were measured. Longitudinal analysis of hair, revealed a peak in inorganic mercury corresponding to the time of mercury ingestion. Organic mercury and selenium in the hair had different patterns of longitudinal variation from that of inorganic mercury. The biological half-life (23.5 d) of serum inorganic mercury levels was in good agreement with values previously reported in the literature.

Multielement analysis was performed on human milk collected on 5-9-d postpartum from 51 Japanese females using inductively coupled plasma (ICP) mass spectrometry (MS), ICP atomic emission spectrometry (ICP-AES) and fluorometry. Thirty-one elements were detected by these analytical methods in milk. Twelve elements (Na, Mg, P, S, K, Ca, Cu, Zn, Se, Sr, Rb, and Mo) were detected in all of the samples. Al, Cs, and Ba were the elements detected by ICP-MS in more than half of the samples. Multiple regression analysis extracted biological attributes of mother and infant, such as maternal stature, maternal wt, or infant's birth wt, as statistically significant factors contributing to the variation in elemental concentration in milk. However, the rates of contribution were small in all cases. It was concluded that the biological attributes of mother and infant examined in this study were not the major factors that contribute to elemental variation in human milk.

Selenium (Se) concentrations in the food of the Gidra‐speaking people of Papua New Guinea were measured by fluorometry. Animal foods contained Se in larger concentrations than plant foods. Animal foods of aquatic origin contained more Se than those of terrestrial origin. Stepwise multiple regression analysis revealed an association between Se and the animal's mercury content. Se concentrations in rice and wheat flour, which were imported from outside of the Gidra land, were more than one order higher than those in locally grown plant foods. The dietary Se intakes of the Gidra in four villages with diverse ecological conditions were calculated based on food consumption survey data. They varied from one village to another: the highest Se intake was observed in the coastal village (132.9 μg/adult male/day), which had greatest fish and purchased food consumption. It was followed by the riverine (97.8) and northern (51.0) villages, and the lowest intake was in the inland village (49.0), where no aquatic animal...

Stable carbon and nitrogen isotope ratios of the animal and plant food of the Gidra, who inhabit lowland Papua New Guinea and subsist mainly on hunting, gathering and horticulture, were measured to characterize the nutritional input of carbon and nitrogen of the Gidra. All the staple plant foods of the Gidra, such as sago and tuberous crops, were classified as C3 plants from their 13C/12C ratios (δ13C). The δ13C of the terrestrial mammals varied to a considerable extent (—11 to —26.5 per mil); the highest value was observed for a species of wallaby inhabiting savanna grassland while two other species of wallabies inhabiting woodland were —25.3 and —22.8 per mil. The δ13C of the aquatic animals was distinctive between marine (—17.0 to —7.1 per mil) and freshwater (—34.6 to —24.0 per mil) groups. The δ15N of the fishes and reptiles were generally higher than terrestrial animals. Major foods of the Gidra were isotopically divided into 5 groups: C3 plant, C3 plant feeder, C4 plant feeder, marine animal and fr...

An animal model of marginal zinc deficiency was tested in mice, and salt taste threshold and salt preference were investigated in the state of marginal zinc deficiency. Two experiments were conducted. In Experiment 1, four-week-old male ICR mice were fed diets of three different levels of zinc content (3.17, 9.27, or 48.13 micrograms Zn/g) for 60 days. Food intake, growth, zinc levels in tissues, hepatic metallothionein (MT) content, and activities of selected enzymes (hepatic and RBC delta-amino-levulinic acid dehydratase (ALAD) and plasma alkaline phosphatase (ALP] did not differ among the groups throughout the experiment, and no overt signs of zinc deficiency were manifested in any group. In Experiment 2, four-week-old male ICR mice were fed a zinc-deficient diet (1.98 micrograms Zn/g) or a zinc-adequate diet (49.14 micrograms Zn/g) for 56 days. Food intake and growth did not differ between the two groups, and no overt signs of zinc deficiency were observed throughout the experiment. Zinc levels in the plasma and femur--but not those in the brain, kidneys, liver, and red blood cell (RBC)--and plasma ALP activities were significantly lower on Day 42 and Day 56 of the experiment in the mice fed the zinc-deficient diet (ZnD group) than in those fed the zinc-adequate diet (ZnA group). Hepatic MT contents were lower in the ZnD group than in the ZnA group on Day 56 only. Salt taste threshold was 0.05% in the ZnA group, while it was 0.1% in the ZnD group, between Day 30 and Day 38, and between Day 44 and Day 52 of the experiment. Preference for 0.9% NaCl solution was no different in the two groups when tested between Day 38 and Day 40 or between Day 52 and Day 54, but that for 1.6% NaCl solution was significantly higher in the ZnD group than in the ZnA group between Day 40 and Day 42, and between Day 54 and Day 56.

The effect of a brief exposure to heat/cold on the subsequent development of toxicity of sodium selenite (SS) was evaluated in male ICR mice. Mice were exposed to one of three ambient temperatures (Ta; approx. 8 degrees, 22 degrees and 33 degrees C). One and a half hours after the beginning of the exposure, they were injected with 45 mumol/kg of SS subcutaneously. The exposure was terminated 3 h after injection and the mice were returned to Ta of 22 degrees C. Heat-induced enhancement of toxicity was recognized in some plasma enzyme activities 3 days after injection and in the suppression of body weight for up to 3 weeks. On the other hand, cold exposure alleviated SS toxicity in terms of these indices. Thus, the Ta during this short period was recognized to be important in determining subsequent development of SS toxicity. At the end of the thermal exposure, heat increased renal concentration of the injected Se. On the other hand, in the liver and the other organs examined, the highest Se concentration was found in the cold-exposed group, followed by the control (room temperature) and the heat-exposed. The relation between the modification of toxicity and the altered distribution was not clear. Neither glutathione level in the liver nor that in the kidney at the time of SS injection could explain the observed modification of the toxicity.

We examined whether selenium (Se) levels in blood were related to dietary habits, age, sex, smoking, consumption of alcoholic beverages or obesity in a group of men and women above 40 years of age. Mean Se concentration in erythrocytes (ESe) was 244±50 (mean±SD) for males, and 235±36 ng/g for females; mean Se concentration in serum (SSe) was 111±19 for males, and 107±16 ng/ml for females. Multiple regression analysis revealed that the following variables were significant in determining ESe and SSe levels: fish consumption, age, and consumption of alcoholic beverages for ESe; and age, pattern of staple food consumption, and hemoglobin concentration in the blood for SSe.

Elemental concentrations of internal organs (cerebrum, cerebellum, heart, spleen, liver and kidney) of Japanese were measured with inductively coupled plasma mass spectrometry (ICP-MS). Sixty-one elements were determined simultaneously, and concentrations of some trace elements in human organs, on which information are scarcely available in the literature, were obtained. The analytical values obtained by ICP-MS and those by other methods were compared and fairly good agreement was found for Cd, Zn and Fe. Moderate agreement was found for Se and Hg, but discrepancy was observed for Mg and Na. Unacceptable values were obtained for some elements, such as Ti, Sc or Ge, probably due to polyatomic molecular interference.

Concentrations of 11 elements (Na, Mg, Al, P, K, Ca, Mn, Fe, Cu, Zn, and Sr) were measured in 505 hair samples collected in 1981 from four (northern, inland, riverine, and coastal) villages of the Gidra who inhabit the lowland of Papua New Guinea. To compare the dietary element intakes with the hair element concentrations, the elimination of elements from hair by washing was first examined. Elimination rates by washing markedly differed from element to element, and a linear relationship between dietary element intakes and hair element concentrations was found in the case of non‐washed hair, but not in the case of washed hair. The comparability of hair element concentrations with dietary element intakes was different according to the villages, and for elements such as Na, Mg, Ca, Cu, and Sr, the difference was partly explained by the element levels in the water utilized in each village.

Multi-element analyses were conducted on internal organs (cerebrum, cerebellum, heart, spleen, liver and kidney) of Japanese obtained from 45 forensic medical autopsy cadavers. Elements analyzed and analytical methods were as follows: Ca, Cd, Cu, Fe, K, Mg, Na, P and Zn by inductively coupled plasma atomic emission spectrometry; total Hg (T-Hg) and inorganic Hg (I-Hg) by cold vapour atomic absorption spectrometry; methyl Hg (MeHg) by gas chromatography; and Se by fluorometry. A significantly positive correlation between Se and T-Hg was observed in kidney, liver, heart and spleen. The T-Hg/Se molar ratio was less than 1 in all the organs examined. The correlation between Zn and Cd was significant in liver and kidney. Multiple regression analyses using Se as a dependent and I-Hg, MeHg, Zn, Cd, Cu as independent variables were conducted on each organ. Inorganic Hg was a significant independent variable in kidney, whereas in liver and spleen it was MeHg. Cadmium was significant in explaining the variations in Se in liver and kidney medulla, indicating Cd-Se co-accumulation in humans.

The effects of sublethal doses of selenite, selenate, selenocystine (Se-Cys) and selenomethionine (Se-Met) as well as of tellurite on body temperature and feeding behavior were examined in male ICR mice. Ten or 30 mol kg of chemicals were injected subcutaneously and body temperature was measured up to 4h. In a separate experiment, the gastric content was weighed 4 h after injection. All chemicals except Se-Met induced both hypothermia and hyperphagia, suggesting that: (a) these two effects are related to each other; (b) among the chemicals tested, Se-Cys appears to be the most potent hypothermia inducer; (c) Se-Met is unique in that it has neither effect.

Mineral and trace element content of the human transitory milk collected on days 6 to 9 postpartum in Tokyo was measured by inductively coupled plasma atomic emission spectrometry (ICP-AES). Ten elements (Na, Mg, P, S, K, Ca, Fe, Cu, Zn, and Sr) were detected in ten-fold diluted milk sample with this method. With the stepwise multiple regression analysis, maternal and infants' biological attributes, such as weight, stature, sex, or age, were noted as factors contributing to the interindividual variation in Na, Mg, P, S, and Sr. Biological mechanism responsible for this selection cannot be found. Days postpartum for the milk collection was selected as a highly significant (p less than 0.001) variable with negative coefficient to explain milk S variation.

The aim of this study was to evaluate the associations of environmental exposure to dioxins with diabetes among general inhabitants in Japan. A cross-sectional study was performed on 1374 participants, who were not occupationally exposed to dioxins, aged 15–73 years, living widely in 75 different residential areas of 25 prefectures in Japan through 2002–2006. Seven polychlorinated dibenzo- p -dioxins (PCDDs), 10 polychlorinated dibenzofurans (PCDFs), 12 dioxin-like polychlorinated biphenyls (PCBs), which are assigned a toxic equivalency factor, and biochemical factors were determined in fasting blood. A questionnaire survey on life-style including past history of diseases and treatments was also performed. We examined the associations of the accumulated toxic equivalents (TEQs) of PCDDs+PCDFs, dioxin-like PCBs and total dioxins with prevalent diabetes. Simple and partial correlation analyses revealed that HbA1c correlated with the accumulated TEQs of PCDDs+PCDFs, dioxin-like PCBs and total dioxins. In logistic regression analyses, the third and the highest quartiles of dioxin-like PCBs had adjusted odds ratios (ORs) of 3.07 (95% CI 1.16–8.81) and 6.82 (95% CI 2.59–20.1) compared to the reference (first plus second quartiles). On the other hand, the highest but not the third quartiles of PCDDs+PCDFs and total dioxins had significantly higher adjusted ORs compared to the respective references. These associations persisted when the subjects with poor liver or poor renal function were removed from the analysis. This recent representative data from general inhabitants in Japan showed associations of environmental exposure to dioxins, especially dioxin-like PCBs, with diabetes.

Plasma levels of selenium (Se) were determined consecutively during a menstrual cycle of six women in three phases (i.e., menses, follicular, and luteal). To detect possible differences in relation to normal pregnancy, plasma levels of Se were also determined in paired samples of maternal and umbilical cord blood from 12 pregnant women. No periodic changes in the plasma Se levels were observed during the menstrual cycle. The intraindividual variation, estimated by coefficients of variation, ranged from 1.9% to 9.9% among the menstrual phases of the subjects. The plasma Se level during pregnancy did not differ significantly from those of nonpregnant women, and those in the second trimester and at delivery were at similar levels (1.58+/-.14 and 1.48+/-.20 mmol/L, respectively). Compared to the levels of maternal Se at delivery, the fetal cord plasma at birth had a significant lower Se level (1.23+/-.34 mmol/L, p.05).

Objectives. To evaluate background exposure levels and determinants of the individual variations in the exposure to dioxins in Japan. Methods. A cross-sectional study was performed on 131 men and 122 women (aged 20–76 years), who resided in five prefectures of Japan and had no occupational exposure to dioxins. Seven polychlorinated dibenzo-p-dioxins (PCDDs), ten polychlorinated dibenzo-furans (PCDFs) and 12 polychlorinated biphenyls (PCBs), which are assigned a toxicity equivalent factor, were determined in fasting blood. Biochemical analysis of plasma and a questionnaire survey on life-style, including dietary habit, were also performed. Factors associated with the levels of dioxin-related compounds in blood were evaluated by multiple linear regression. Results. The median of total toxicity equivalents (TEQs) in men and women was 17 and 16 pg TEQ/g lipid, respectively, with no gender difference. After adjustment for age and other covariates, plasma concentrations of eicosapentaenoic acid, a biomarker of fish intake, were found to be positively associated with blood levels of total dioxin, PCDDs, PCDFs and PCBs, all of which were expressed on a TEQ basis (P

The levels and its interindividual and intraindividual variations of selenium (Se) and mercury (Hg) in erythrocytes and plasma were investigated in seven healthy young men during a period of 10 wk, with emphasis on the relationship to the dietary intake of several defined food items. The intraindividual variation, estimated by coefficients of variation (CVs), was 9.9% for plasma Se (PSe), 9.5% for erythrocyte Se (ESe), 42.4% for PHg, and 11.7% for EHg on the average. Significant correlations were found for mean ESe levels in each subject and his fish-eating frequency during this study (r=0.752, p

The authors would like to thank Prof. Michio Iguchi for his discussion, and the answers are as follows;(1) We corrected the sign of Φy* in the section 1 of equation (2). And also we corrected the description of related equations (3), (7), (15) - (18).(2) We think the first evaluation method is useful as an approximate solution, though it is improved by considering the excavation force.(3) We proposed that the first evaluation method should be used when the ratio of embedded depth and half foundation width is smaller than 3.0.(4) About the numerical calculation step of the second evaluation method, we think it is a difference in approach about how to lead from the exact solution to a convenient solution.

The ability of cadmium-bound metallothionein(Cd-MT) to induce apoptosis was investigated in vivo and in vitro. Administration of purified Cd-MT (0.15 mg MT bound Cd per kg body weight) to the rat induces DNA fragmentation, a biochemical characteristic of apoptosis in the kidney at 16 h, which was detectable by ethidium bromide staining on an agarose gel. It was still detected 24 h after administration. Induction of apoptosis by Cd-MT was specific to kidney; it was not observed in cerebrum, cerebellum, heart, lung, liver, testis, dorsolateral prostate, and ventral prostate. In contrast, addition of Cd-MT (0.01-100 microM) to the cultured porcine kidney LLC-PK1 cells failed to induce apoptosis under the condition where cadmium chloride (10 microM) did. There was no additivity of induction of apoptosis by CdCl2 (10 microM) in the presence of Cd-MT (0.01-100 microM). To examine the effect of intracellular MT on cadmium-induced apoptosis in cultured cells, new cell lines were established, which constitutively produce MT, being termed as Cd(r)-LLC-PK1 cells since Cd-MT exogenously added had much less permeability to the cultured cells. Followed by exposure of wild-type LLC-PK1 cells to 50 microM CdCl2 for 24 h, the surviving cells(Cd(r)-LLC-PK1 cells) induce MT at the level of 1.9 microg/2 x 10(6) cells. In Cd(r)-LLC-PK1 cells, 10 microM CdCl2 failed to induce apoptosis, but 60 microM CdCl2 could exert the apoptotic response, indicating that intracellular MT which was induced by CdCl2 did not facilitate CdCl2-elicited apoptosis. Furthermore, chromatin in rat kidneys was condensed by Cd-MT, but not that in LLC-PK1 cells. Thus, Cd-MT induces apoptosis in rat kidneys, but not in the cultured renal cells, suggesting that the ionic form of cadmium was required for programmed cell death.

Blood examination was conducted for the four Gidra-speaking village groups in Papua New Guinea, who were characterized by high Fe intake and high malaria prevalence with marked inter-village differences. The northern riverine villagers, whose Fe intake was higher than the other three village groups, did not suffer from Fe-deficiency anaemia in their malaria-endemic environment; nor did the inland villagers, with their second highest Fe intake and their malaria-free environment, suffer from Fe-deficiency anaemia. However, several individuals of the southern riverine village suffered from anaemia in a malaria-endemic environment, although their Fe intake was almost the same as the inland villagers’. A considerable proportion of the coastal villagers were anaemic, reflecting the lowest Fe intake and the highest malaria prevalence. An inter-village comparison of the relationships between haemoglobiin levels and transferrin saturation revealed that the southern riverine villagers needed smaller amounts of circulating Fe for erythropoiesis than the northern riverine and inland villagers, reflecting the long-term human-environment conditions such as the density of malaria vectors and the people’s dietary habits. Fe supplementation was not judged effective against hypoferraemia and/or anaemia in such a population. As the incidence of malaria had no significant long-lasting effect on Fe stores or circulating Fe concentration, but did have an effect on anaemia, the hypothesis that malaria causes a transfer of Fe from the blood to parenchymal tissues as a defence against infectious diseases was not supported.

Element concentrations in ribs obtained from elderly Japanese people (17 males and 28 females; mean age, 81.5 years) were determined by atomic absorption spectrometry (AAS), inductively coupled plasma atomic emission spectrometry (ICP-AES), and ICP mass spectrometry (ICP-MS). Nine elements--Na, Mg, P, K, Ca, Fe, Zn, Sr, and Pb--were determinable in most of the subjects by a combination of AAS and ICP-AES. The levels of these elements were generally comparable with those obtained in our previous study on ribs from younger Japanese. By the use of ICP-MS, Sn (median, 0.79 micrograms/g dry bone) and Ba (1.3 micrograms/g) were determinable in all of the subjects analysed (n = 35) and 18 other elements at lower concentration levels were also detected in some of the subjects. An exploratory statistical analysis was carried out to find element(s) of which level(s) in rib vary in the presence of degenerative chronic diseases, using information obtained from pathological autopsy reports and medical histories of the present subjects. It indicated that (i) Pb and Zn, (ii) Ba, and (iii) Sr levels in the ribs varied in the presence of cancer, cerebrovascular damage, and bone problems, respectively. The present results were discussed in relation to the results of the previous epidemiologic and experimental studies.

The health status of four populations depending on traditional subsistence in Papua New Guinea was compared by the dipstick test urinalysis. Conspicuous inter-population difference in the distribution of urinary pH was attributed to the levels of protein intake and the balances of sodium and potassium intake. The percentage of positive findings on protein differed by population along with the percentages of urobilinogen and bilirubin; the higher percentage of protein positives (12-16%) found in less urbanized populations suggests a high risk of hepatic and/or renal disorders in traditional societies. The very low percentage, 0.3 percent, of positive findings on glucose among 1, 132 urine samples tested indicated that diabetes mellitus was not yet the major problem. Simultaneously, however, the fact that glucose positives were found only in the most urbanized villages indicates increasing risk of diabetes even in the traditional populations during future urbanization. Asia Pac J Public Health1994; 7(3): 165-72.

To monitor the exposure to mercury (Hg) vapor among university staff members and students who occasionally handle elemental Hg in laboratory experiments, urine samples were collected at health examinations conducted by the Health Service Center, University of Tokyo, for six years. Geometric mean of urinary Hg concentrations of 343 samples collected from 234 subjects was 1.61 micrograms Hg/g creatinine (Cr), with the range of 0.30 to 9.31 micrograms Hg/g Cr. Elevated urinary Hg levels, i.e. 3 micrograms Hg/g Cr or higher, were found only among the subjects who worked in several laboratories. This urinary Hg level is judged to correspond to 1-2 micrograms/m3 of air Hg concentration in working areas. The contribution of dental amalgam fillings to urinary Hg excretion, though it exists, was concluded to be small from the result of multiple regression analysis.

The influence of dental amalgam fillings and fish eating frequency on the urinary mercury (Hg) level was evaluated in 1642 children (ages: 3-18) living in Tokyo. Geometric mean of the urinary Hg level was 1.9 microgram Hg/l and 1.9 micrograms Hg/g creatinine (Cr) for boys and 2.1 micrograms Hg/l and 2.0 micrograms Hg/g Cr for girls. Multiple regression analysis was conducted using: (1) urinary Cr concentration (only in the case of urinary Hg expressed as microgram Hg/l); (2) age; (3) gender; (4) number of dental amalgam fillings; and (5) fish eating frequency as independent variables. As a result, all the variables examined were significant and the explanatory powers (square of multiple correlation coefficient) of these variables were 17 or 7% for urinary Hg expressed as microgram Hg/l or microgram Hg/g Cr, respectively. Number of dental amalgam fillings or fish eating frequency explained only up to 1.5% of the total variance of urinary Hg. Contribution of Cr concentration, age and gender to urinary Hg level is also discussed.

When the nutritional status of minerals and essential trace elements is assessed by their levels in plasma, intra-individual variation in the measured values, particularly diurnal variation, must be considered. In this paper, concentrations of nine elements (Na, Mg, P, K, Ca, Fe, Cu, Zn, and Se) in plasma collected 7 times in a 24-h period from 10 healthy Japanese adults were measured with hemoglobin and plasma concentrations of proteins (total protein, albumin, retinol binding protein (RBP), ceruloplasmin, and transferrin), total cholesterol, and cortisol. Then the pattern of diurnal variation in, and the interrelationships among, these parameters were clarified in subjects who consumed an ordinary meal. Significant diurnal variation examined by two-way analysis of variance (variations due to subject and sampling time) was found for Zn, RBP, and cortisol. Plasma Zn level was higher in the forenoon samples than in those taken in the afternoon. The pattern of diurnal variation found for cortisol was similar to, but slightly different from, that for Zn. The correlation coefficient between Zn and cortisol was significant (r = 0.555) using the standardized values for individuals, and in the result of multiple regression analysis, cortisol level was selected as the significant explanatory factor for Zn variation; however, the sampling time was the most significant factor. For other elements besides Zn, no significant diurnal variation was found. Moreover, no meaningful factors were selected for variations of those elements in the result of multiple regression analysis. These results indicate that, in assessing Zn nutriture with its plasma levels, it is necessary to unify the sampling time.

The relationships among element concentrations (Na, Mg, Al, P, K, Ca, Cr, Fe, Mn, Cu, Zn, Sr, total Hg, organic Hg, inorganic Hg, Pb) and stable carbon and nitrogen isotope ratios ( 13 C 12 C and 15 N 14 N ) in animals consumed by the people called Gidra, who inhabit the lowland of Papua New Guinea, were examined. Animals analyzed included mammal, bird, fish, shellfish, reptile, crustacean, and insect. Highly significantly positive correlations were observed between total Hg concentrations and 15 N 14 N (r = 0.796), between organic Hg concentrations and 15 N 14 N (r = 0.781), and between inorganic Hg concentrations and 15 N 14 N (r = 0.739). This was interpreted to indicate that Hg was an element which accumulates in animals along the food chain. Based on the regression function of Hg on δ15N, the bioconcentration factor for total, organic, and inorganic Hg was estimated to be 5.

Anthropometric data, nutrient intake data, and blood biochemical parameters were analyzed for 66 elementary school children living in Tokyo, Japan, and their nutritional status was evaluated focusing on three problems: (1) zinc nutriture and growth, (2) anemia with iron deficiency, and (3) lipid nutriture and obesity. The subjects' mean energy and protein intakes met the recommended levels for Japanese children. However, their zinc intake levels were inadequate at 7.2, 8.3, and 8.5 mg in grades 2 (mean age: 8 yr), 4 (10 yr), and 6 (12 yr), respectively. Mean serum zinc concentration was 0.82 +/- 0.15 microgram/ml; the percentages of subjects who showed serum zinc concentration lower than 0.68 microgram/ml, the lower limit of the normal serum zinc concentration, were 28.6, 15.4, and 5.0% in grades 2, 4, and 6, respectively. These serum zinc concentrations indicated the existence of marginal zinc deficiency in some children, particularly in grade 2, though it was not severe enough to retard growth. Their iron intake levels (8.2, 10.2, and 10.2 mg for grades 2, 4, and 6, respectively) in combination with the proportion of iron intake from animal foods (37%) were judged to be adequate because no children showed serum ferritin, serum iron, or transferrin saturation levels lower than the criteria levels recommended for iron deficiency. Moreover, no definitely anemic children were found. Daily lipid intakes were 65.7, 74.5, and 78.3 g in grades 2, 4, and 6, respectively, and the mean percentage of energy intake from lipid to total energy intake, 32%, exceeded the level recommended. Mean serum total cholesterol concentrations and the percentage of subjects with elevated cholesterol levels (greater than or equal to 200 mg/dl) were high compared with the reported values. Means of the body mass index (BMI) and Rohrer Index (RI) for the subjects were slightly higher than Japanese standards. With these parameters for obesity, triglycerides and atherogenic index were positively correlated and HDL cholesterol and HDL cholesterol percentage to total cholesterol were negatively correlated.

Mercury has existed in the human environment at every stage of human evolution. Therefore, how was, and is, human adaptation to the existing level of mercury to be clarified to approach the limitation in our adaptability. For this, it is necessary to evaluate the environmental characteristics of each local human ecosystem. 1. Mercury in a tropical human ecosystem with traditional ways of living. In an ecosystem in the Papua lowlands, mercury, mostly in the form of methylmercury, is found in fishes and reptiles at elevated levels. Mercury levels are correlated with the stable isotope ratio of nitrogen (15N/14N) in animal food which indicates a biomagnification of mercury accumulation through the food chain. In animal foods, mercury to selenium ratio is getting close to unity on the molar basis with increasing mercury levels. Dietary mercury intake and hair mercury levels in the fish-eating sector are comparable with those in developed countries. Balance between Se and Hg in the dietary intake is inclined to relative excess of Se to Hg. 2. Mercury in an urbanized ecosystem (Tokyo). In an urbanized ecosystem in an industrialized country, the major source of mercury is via fish consumption. In organs obtained from forensic autopsy cases in Tokyo, methylmercury levels are uniform through all the organs (30 to 50 ng/g on average) except the liver (113 ng/g), but inorganic mercury levels are high in the liver and kidney (266 to 456 ng/g) and low in the brain, heart and spleen (4 to 9 ng/g). Selenium levels are significantly correlated with mercury levels in some organs, particularly in the kidney, where% inorganic to total mercury is as high as 85%. From these results and additionally the results obtained on harbor seals caught in the Okhotsk sea, the role of selenium in adapting environmental mercury will be hypothetically discussed.

Elemental concentrations (Ca, Cu, Fe, Mg, P, Se and Zn) in the hair of Japanese were examined in relation to those in internal organs (cerebrum, cerebellum, heart, spleen, liver, kidney and rib). No significantly positive correlation was found between elemental concentration in hair and that in internal organ. This result indicates the restricted use of hair as a medium for the estimation of nutritional status of the essential elements examined in the present study, at least on an individual basis. The correlations between the concentrations in organs are also presented.

To study the effect of the environments shared by spouses on the development of cancer and some chronic diseases, we analyzed the correspondence of disease history in 21,592 fathers and mothers using the baseline data of a population-based cohort study. The observed number of cases (O) whose parents had the same disease history was statistically significantly greater than the expected (E); the O/E ratio was 1.53 (95% confidence interval (CI): 1.43–1.63) for all malignant neoplasms, 5.22 (95% CI: 2.81–9.70) for esophageal cancer, 1.63 (95% CI: 1.37–1,93) for stomach cancer, 3.01 (95% CI: 1.89–4.79) for colorectal cancer, 3.90 (95% CI: 2.75–5.53) for liver cancer, 3.14 (95% CI: 1.95–5.08) for lung cancer, 6.73 (95% CI: 2.53–17.87) for bladder cancer, 1.66 (95% CI: 1.54–1.78) for apoplexy and 1.67 (95% CI: 1.51–1.86) for heart disease. The results of the present study suggest that the environmental factors shared by family members for a long time may contribute to familial aggregation of cancer and some chronic diseases.

In order to examine whether some characteristics of eating behavior are related to physical growth and weight increment in young children, a longitudinal prospective study was conducted. The eating behaviors of 11 age-matched normal-weight preschool children were observed at lunchtime on 18 consecutive days. The same set of observations was carried out three times when the children were 40, 52 and 59 months old, on average. MANOVA procedures for repeated measures design revealed that the eating behavior of the subjects changed considerably between the first and second observation stages, whereas it did not change significantly between the second and third stages. It was considered that eating behaviour developed mostly between the first and second observation stages and that the subjects were able to eat completely independently by the second observation stage. The increment in the children's weight per month began to show individual variation at the age of 48 months between the first and second observation stages. Coincidentally, the relationship between eating behavior and physique first appeared at the second observation stage and a similar relationship was observed at the third stage. The partial correlation coefficients and the multivariate multiple regression of MANOVA were performed for this analysis. Meal duration was the factor most strongly related to weight and BMI, whereas in contrast, growth history and familial factors influenced the eating behavior at the first observation stage. The present results indicate that eating behavior was one of the factors related to the rapid increase in weight soon after or just at the time of initiation of complete self-feeding in normal-weight children.