Geographical distribution and background levels of total mercury in air in Japan and neighbouring countries

Concentrations of total atmospheric mercury were determined in air collected from several locations in Japan and neighbouring countries to elucidate the geographical distribution and the background levels of total mercury in environmental air. The concentrations of mercury in urban air in Japan were 2.3-67 ng/m3, mean value 11.2 ng/m3. Those values were higher relative to those in urban air of other countries around Japan. In the past, a large quantity of mercury was used as an agricultural fungicide and a chloralkali catalyst in Japan. Therefore, the concentrations of mercury in rural air were higher rather than those in urban air. This phenomenon supports the hypothesis that the residual mercury used in the paddy field in the 1970s still remains in soils of Japan.

Tendency toward atopy in Kawasaki disease

To evaluate the possible trend towards developing allergic disease in children who had suffered from Kawasaki disease (KD), we evaluated data related to allergy that were collected by parental questionnaire on 1,165 children who had suffered from KD. Comparisons were made with 5,825 sex- and age-matched control children. The incidence of household pets and of cigarette smoking in the family were significantly lower in the children with a history of KD than in those of control children. A family history of allergy was significantly more common in the children with a history of KD (71%) versus the controls (56%) (P < 0.001). The incidence of atopic dermatitis and of allergic rhinitis was significantly higher (by approximately 1.7 times) in the KD children versus the control group (P < 0.01), even in subgroups with no family history of allergy.

CONCLUSION

We suggest that a genetic predisposition to atopy may be associated with a susceptibility to KD. Patients with KD tended to develop atopic dermatitis and allergic rhinitis.

Characteristic evoked potentials in childhood-onset dentatorubral-pallidoluysian atrophy

To determine the characteristics of multimodal evoked potentials (MEPs) in childhood-onset dentatorubral-palli-doluysian atrophy (DRPLA) we studied three DRPLA patients with progressive myoclonus epilepsy. Brainstem auditory evoked potentials showed reduced or absent brainstem components as well as delayed latencies. In addition, short latency somatosensory evoked potentials (S-SEPs) had prolonged central conduction time and reduced amplitude of cortical components. Two patients with symptom onset in the first decade of life had extremely enlarged flash visual evoked potentials with shortened latency even in the absence of giant SEPs. Therefore, children with progressive myoclonus epilepsy and the above MEP findings are likely candidates for childhood-onset DRPLA and should undergo DNA analysis for DRPLA.

Potentiation of antitumor and antimetastatic activities of adriamycin by a novel N-alkylated dihydropyridine, AC394, and its enantiomers in colon cancer-bearing mice

PURPOSE

We have previously shown that a series of N-alkylated 1,4-dihydropyridines potentiate the therapeutic efficacy of vincristine in vincristine-resistant P388 leukemia. The purpose of this study was to investigate the ability of one of the compounds, AC394, and its enantiomers to potentiate the antitumor activity of adriamycin against colon cancer cells in vitro and in vivo.

METHODS

The effects of AC394 on potentiation of adriamycin cytotoxicity and enhancement of its accumulation were evaluated using colon 26, HCT-15 and MCF-7 cells. Furthermore, the activities of AC394 and its enantiomers were compared. We also studied the combined effects of (+)-AC394 and adriamycin on subcutaneously (s.c.)-implanted and liver metastasis tumor models.

RESULTS

AC394 potentiated the cytotoxicity of adriamycin and enhanced its accumulation in colon cancer cells (colon 26 and HCT-15), which are known to express P-GP (P-glycoprotein) intrinsically. Enhancement of adriamycin accumulation by AC394 was found in s.c.-implanted colon 26 cells in vivo. Although both enantiomers of AC394 showed equal activity in vitro, (+)-AC394 was more effective than (-)-AC394 given orally. (-)-AC394 was found to be cleared more rapidly from the plasma than (+)-AC394. Thus, (+)-AC394 was evaluated for further study. Administration of (+)-AC394 significantly potentiated the antitumor activities of adriamycin in human colon cancer HCT-15 cells implanted s.c. Furthermore, in the liver metastasis model using colon 26 cells, a model completely resistant to adriamycin, the combination therapy of adriamycin with (+)-AC394 produced superior antitumor effects over adriamycin alone.

CONCLUSIONS

A newly synthesized N-alkylated 1,4-dihydropyridine derivative, (+)-AC394, showed superior effects on the potentiation of adriamycin antitumor and antimetastatic activities in vivo. These results suggest that this combination may have therapeutic efficacy not only against primary colon cancers but also against metastatic liver cancer.

Purification and characterization of two lectins from calllus of Helianthus tuberosus

Two lectins were purified from Helianthus tuberosus callus by maltose affinity chromatography and subsequent preparative electrophoresis. The lectins were designated HTA I and HTA II and their molecular masses were about 34 kDa by gel-filtration chromatography. A single band of 17 kDa and bands of 17 kDa and 18 kDa were detected after SDS-PAGE of HTA I and HTA II, respectively, indicating that HTA I is a homodimer while HTA II is a heterodimer. The amino acid compositions of the two lectins were very similar; they were rich in glycine residues, lacking detectable amounts of methionine, cysteine, and histidine. A hapten-inhibition assay showed that HTA I and HTA II had identical saccharide-binding specificity to the extent tested and belonged to the group of so-called mannose/glucose-binding lectins. They had high affinity for alpha-linked manno-oligosaccharides. Each HTA completely lost its hemagglutinating activity at pH 5.0, as a result of its dissociation to monomers, but it did not lose its ability to bind to oligosaccharides.

Studies on the levels in atmospheric concentrations of mercury in Japan

Several factors that influence the total mercury levels in atmosphere concentrations of mercury in Japan were investigated. The daily variation in the mercury content of air was ascribed to daily temperature differences. The maximum amount of mercury in air was found at about 1:00 pm; much smaller amounts were found in the morning and in the evening. The minimum amount of mercury in air was found at about midnight. The effect of atmospheric pressure was less obvious. The seasonal variation indicated that the mercury concentration showed no apparent trend for samples collected in daytime on clear days with no precipitation. The total mercury concentration in the summer as a whole, however, was slightly higher than that of the winter. In addition, the total mercury levels in air have been monitored over a period of 17-years (1978-1994) at three different environmental stations. In 1988, the total mercury in air was minimum levels at three stations and was corresponded to background levels, then they began to rise steadily up to date. It is found that the current atmospheric concentrations of total mercury inferred from measurements of air has an increasing tendency every year.

Syndrome of inappropriate antidiuretic hormone secretion (SIADH) in children undergoing high-dose chemotherapy and autologous peripheral blood stem cell transplantation

The incidence of SIADH (the syndrome of inappropriate antidiuretic hormone secretion) was analyzed retrospectively in 43 children who received marrow-ablative chemotherapy before autografts with peripheral blood stem cells for lymphoid malignancies. SIADH was documented in three children (ages 3, 13, and 13 years) who received chemotherapy, which included high-dose methyl 6-[3-(chloroethyl)-3-nitrosoureido]-6-deoxy-alpha-D-glucopyranoside (MCNU) and cyclophosphamide, under a concomitant overhydration protocol. SIADH was manifested as frequent vomiting in two patients and as generalized seizure in one. Hyponatremia (< 125 mEq/L), hypo-osmolality (< 260 mOsm/kgH2O), and continued urinary excretion of sodium (> 30 mEq/L) were used to diagnose SIADH in these three patients. All signs and symptoms subsided within 24 hours either by fluid restriction alone (n = 1) or by supportive care including anticonvulsant and D-mannitol, or hyperhydration with saline plus 5% glucose and diuretic. None of the patients died. Careful monitoring of the serum sodium level, as well as the osmolality of plasma and urine, should be incorporated into the patient management protocol for this type of high-dose chemotherapy.

Estimation of 1992-1993 dietary intake of organochlorine and organophosphorus pesticides in Fukuoka, Japan

To estimate Japanese daily intakes of organochlorine pesticides such as hexachlorocyclohexanes (HCHs), 1,1,1-trichloro-2,2-bis-(4-chlorophenyl)-ethane (DDTs), dieldrin (aldrin), heptachlor-epoxide (heptachlor), and hexachlorobenzenes (HCBs) from foods, fish, fish products, meat, eggs, milk, and milk products were analyzed as major sources of these pesticides in the diet. Estimated daily intakes (EDIs) per person were 0.56 microgram for total HCH, 0.20 microgram for gamma-HCH, 0.09 microgram for dieldrin, 1.42 micrograms for total DDT, and 0.15 microgram for HCB. Similarly, daily intakes of organophosphorus pesticides such as malathion and chlorpyrifosmethyl were estimated by analyzing wheat and wheat products as major contributing foods. EDIs of malathion and chlorpyrifos-methyl were 0.22 and 0.24 microgram, respectively. Daily intakes of total HCH, dieldrin, and total DDT in fiscal year 1992-1993 decreased 29, 44, and 40%, respectively, but gamma-HCH intake increased 167%, in comparison with results of total diet studies for fiscal years 1980-1984. It was also shown that increase in gamma-HCH intake was due to recent increase in consumption of imported meat and meat products. Malathion intake did not change significantly. This method, which estimates EDIs based on concentrations of pollutants in main foods and statistical data of food consumption from the Japanese National Nutrition Survey, is considered to be sufficiently accurate for use as a simplified total diet study.

Collection and transplantation of peripheral blood stem cells in very small children weighting 20 kg or less

The safety and efficacy of harvesting peripheral blood hematopoietic stem cells (PBSC) were evaluated in 38 children weighing 20 kg or less, with the smallest patient weighing 7 kg. The patients had a median age of 42 months and included 26 children with acute leukemias or lymphoma and 12 with various solid tumors. A total of 81 aphereses were performed, mostly in the recovery phase of chemotherapy, with or without granulocyte colony-stimulating factor, using a CS-3000 cell separator and regular procedure no. 3. Blood was withdrawn at a mean rate of 30 mL/min (range, 17 to 46 mL/min) through a temporary radial arterial catheter (20 to 24 guage) and returned through a larger catheter in a peripheral vein. Morbidity related to PBSC harvest was low and all aphereses were completed within 3 hours. The volume of blood per kilogram processed for each apheresis ranged from 85 to 615 mL (median, 270 mL). The median number of colony-forming units--granulocyte-macrophage (CFU-GM) and CD34+ cells collected were, respectively, 34 x 10(4)/kg and 15 x 10(6)/kg per apheresis and 126 x 10(4)/kg and 31 x 10(6)/kg per patient. Thirty-three patients (87%) required only a single apheresis to collect the minimum requirement of 10 x 10(4) CFU-GM/kg, including 28 patients (74%) from whom 30 x 10(4) CFU-GM/kg was obtained in a single apheresis. Twenty-three of the patients subsequently underwent autografts with PBSC. The median number of days required to achieve an absolute granulocyte count of 0.5 x 10(9)/L and a platelet count of 50 x 10(9)/L were, respectively, 10 (range, 6 to 15) and 14 (range, 9 to 46). The patients remained dependent on platelet transfusion support for a median of 10 days (range, 5 to 35). Thus, harvesting PBSC in very small children with active cancers is effective and safe and does not involve the risk of anesthesia or multiple invasive marrow aspirations.

Clinical trial of a combination of rice bran fiber and cholestyramine for promotion of fecal excretion of retained polychlorinated dibenzofuran and polychlorinated biphenyl in Yu-Cheng patients

A clinical trial using the combination of rice bran fiber (RBF) and cholestyramine (CHO) was carried out on Yu-Cheng patients in 1993-1994. By the analysis of blood and stool samples collected from the patients before and after (or during in the case of stool), it was verified that the administration of RBF and CHO is effective for excretion of polychlorinated biphenyl (PCB) (p < 0.05) and polychlorinated dibenzofuran (PCDF), especially 2, 3, 4, 7, 8-pentachlorodibenzofuran (p < 0.05). However, the degree of effectiveness varied upon individual patients from 60 to 160% for 2, 3, 4, 7, 8-pentachlorodibenzofuran, from 30 to 110% for 1, 2, 3, 4, 7, 8-hexachlorodibenzofuran and from 50 to 190% for PCB, respectively.

[Levels of PCDDs, PCDFs and coplanar PCBs in the blood and stool of Taiwanese Yu-Cheng patients]

Levels of PCDDs, PCDFs and coplanar PCBs were measured in the blood and stool obtained from seventeen patients with Yu-Cheng in Taiwan. The average total concentrations of PCDDs, PCDFs and coplanar PCBs in the blood collected from Yu-Cheng patients in January 1993 and August 1994 were 590 and 570 pg Toxic Equivalents (TEQs)/g lipid, respectively. The concentrations of PCDDs, PCDFs and coplanar PCBs in the blood of patients were 21, 540 and 10 pg TEQs/g fat, respectively. On the other hand, the fecal excretion of PCDDs, PCDFs and coplanar PCBs were 26, 720 and 15 pg TEQs/day, respectively. The composition of congeners in the feces was quite similar to the one in the blood. The half lives were estimated as 9.1 and 8.6 years for 2, 3, 4, 7, 8-pentachlorodibenzofuran and 1, 2, 3, 4, 7, 8-hexachlorodibenzofuran based on fecal excretion, respectively.

N-alkylated 1,4-dihydropyridines: new agents to overcome multidrug resistance

New N-alkylated 1,4-dihydropyridine derivatives were synthesized and their ability to overcome multidrug resistance was examined in vincristine-resistant P388 cells (P388/VCR cells). Compounds that possessed an arylalkyl substituent on the dihydropyridine ring nitrogen were more potent than verapamil in potentiating the cytotoxicity of vincristine against P388/VCR cells. However, neither drug effectively enhanced the antitumor activity of vincristine in tumor-bearing mice. Introduction of basic nitrogen-containing substituents on the side chain of 1,4-dihydropyridines gave improved activity in vitro and in vivo. The piperazine derivative 12c and 12o were more than 10 times as potent as verapamil in vitro. Four compounds selected for in vivo testing showed superior antitumor activity in P388/VCR-bearing mice in combination with vincristine. The structure-activity relationships of the compounds are discussed.

Concentration of mercury in hair of diseased people in Japan

The purpose of this investigation was to estimate the total hair mercury of diseased people (not including patients of mercury poisoning such as Minamata disease). Hair samples were collected from 133 diseased volunteers in Tokyo and the surrounding areas from Oct. 1992 to June 1993. The total mercury concentrations in the hair of ordinary diseased people (atopic dermatitis, asthma, dementia, cerebral infarct, osteoporosis, hypertension and diabetes) were from 2.08 ppm to 36.5 ppm. Those values were considerably higher than that of healthy people of the same age groups. However, the uptake routes and the metabolic mechanism of high hair mercury concentrations in diseased people are not clear.

Concentration of mercury in hair of Japanese people

This investigation was made to estimate current normal concentrations of total mercury in the hair of Japanese people. Hair samples were collected from 365 healthy volunteers in Tokyo and the surrounding areas from June 1992 to June 1993. Mercury contents in the samples were analyzed by gold amalgam flameless atomic absorption spectrophotometry. The mean of the concentrations of total mercury in the hairs of the males (2.98 ppm, 81 volunteers with an average age of 34.7, age 11 to 73) was higher than that of the females (2.02 ppm, 284 volunteers with an average age of 26.5, age 12 to 82). In both the male and female, the mean of the concentrations of total mercury in hair increased with age up to their thirties, then gradually decreased. The concentrations of total mercury in the hair of females at age 18 to 40 showed greater fluctuation, as compared to those of males in the same age groups. In both males and females, the concentration of total mercury in the hair was higher in volunteers who have a preference to fish in their diet than in those who prefer other foods. In both males and females, there was no positive correlation between the total hair mercury and the place of residence of the volunteer although the total hair mercury (2.30 ppm) of male volunteers who inhabit Ibaragi and Chiba, in eastern part of Tokyo, facing the Pacific Ocean or both the Pacific Ocean and Tokyo Bay, was lower than those (3.30 and 3.25 ppm) of male volunteers of other two areas.(ABSTRACT TRUNCATED AT 250 WORDS)

Splenectomy for treatment of immunoblastic lymphadenopathy

A 5-month-old girl was diagnosed with immunoblastic lymphadenopathy (IBL) on the basis of clinical symptoms and pathological findings. alpha-interferon, immunosuppressive agents such as cyclosporin A, deoxyspagarine, and azathioprine, and an alternating regimen of low-dose 6-mercaptopurine, cyclophosphamide and methotrexate were tried with partial success. Finally, splenectomy was carried out at 58 months of age, inducing prolonged complete remission without any medication.

[Therapeutic trials for promotion of faecal excretion of PCDFs by the administration of rice bran fiber and cholestyramine in Yusho patients]

It is well-known that Yusho disease was caused by polychlorinated dibenzofurans (PCDFs), and that 2, 3, 4, 7, 8-Pentachlorodibenzofuran (PnCDF), 1, 2, 3, 4, 7, 8- and 1, 2, 3, 6, 7, 8-Hexachlorodibenzofurans (HxCDFs) still retain in the patient bodies. As patients usually suffer from various chronic syndrome, an effective treatment is extremely needed. In order to assess the rice bran fiber (RBF) and cholestyramine on stimulating faecal excretion of PCDFs, two clinical trials were carried out in 1990 and 1991. In the first trial in 1990, 10 g of RBF (dietary fiber content was 50%) and 4 g of cholestyramine were administered to four Yusho patients three times a day for a week. The stool from patients were collected a week before and during the administration. These were pooled respectively, and then two samples for measurement. In the second trial in 1991, 10 g of dietary fiber rich RBF (refined-RBF, dietary fiber content was 85%) and 4 g of cholestyramine were administered to four Yusho patients three times a day for two weeks. In this trial, three stool samples were obtained from each patient, ie., a week before administration, and first and second week during administration. Level of PCDFs was determined by high resorption GC/MS and the following results were obtained. 1) In the first trial (1990) the faecal excretion of PnCDF and HxCDFs increased at the rates of 42-88% and 7-47%, respectively, in three out of four patients.(ABSTRACT TRUNCATED AT 250 WORDS)

[Studies on the application of residual PCBs, PCQs and PCDFs concentrations to Yusho diagnosis]

Results of Yusho annual inspection were reviewed from the view point of correlation of PCBs, PCQs and PCDFs concentration in blood or subcutaneous adipose tissue and clinical findings. To make discussion quantitative, fifteen terms of clinical findings on Yusho disease were quantified on the severity by evaluating (+) as 2 points, (+-) as 1 point and (-) as 0 point. First, the temporal variations of the severity of clinical findings on 5 Yusho patients were figured. Additionally, the temporal variations of blood triglyceride and PCBs concentration, and GOT were also surveyed. The adopted terms of clinical findings were general malaise, cough, sputum, headache, abdominal pain, peripheral neuropathy, soreness of joints, deformity of nails, comedo formation, acne-like eruption, secondary infection, scar formation, disorder of Meibomian glands, edema of eye lids and increased discharge from the eyes. During the investigated period from 1972 to 1988 the total score of clinical findings clearly decreased on two patients who had high score, tended to decrease on two other patients, and was not clear on another patient. Secondly, the correlation coefficients were calculated between each of PCDFs, PCBs or PCQs concentration in subcutaneous adipose tissue or blood and the total score at the year in which the adipose tissue and blood were taken. For the female patients the correlation coefficient of PCDFs concentration in subcutaneous adipose tissue and total score of clinical findings was the highest of all (r = 0.9885). However, for the male patients it was not available because the number of the subjects was only two. Thus far it has been reported that the powers of PCBs gas chromatogram pattern and PCQs concentration as criteria for Yusho diagnosis are low as for the subjects who belonged to the border area between Yusho patients and normal persons. This survey suggests that PCDFs concentration in subcutaneous adipose tissue can be a potent criterion that has a high correlation with the clinical findings of Yusho.

[Therapeutic trial for promotion of fecal excretion of PCDFs and PCBs by the administration of cholestyramine in Yusho patients]

Any effective therapy for elimination of causal agents remaining in Yusho patients was not found until now. To know the profile of fecal excretion of polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs), the amounts of PCDFs and PCBs in the stool of six Yusho patients with the typical symptoms were determined. The stool samples of Yusho patients were collected in 1989. PCDFs, i.e., 2,3,7,8-tetrachlorodibenzofuran (TCDF), 2,3,4,7,8-pentachlorodibenzofuran (PnCDF), 1,2,3,4,7,8- and 1,2,3,6,7,8-hexachlorodibenzofurans (HxCDFs), 1,2,3,4,6,7,8-heptachlorodibenzofuran (HpCDF) and octachlorodibenzofuran (OCDF) were detected in all of the samples. PCDFs found in the stool samples were mostly PnCDF and HxCDFs. Of PCDFs detected, PnCDF and HxCDFs contributed to 42 +/- 4.7% and 43 +/- 5.5% as mean +/- SE, respectively. The fecal excretion of PnCDF and HxCDFs in Yusho patients was 720 +/- 490 pg/day and 790 +/- 620 pg/day as mean +/- SE, respectively. On the other hand, the fecal excretion of PnCDF and HxCDFs in normal controls was 32 +/- 13 pg/day and 47 +/- 5.2 pg/day as mean +/- SE, respectively. The fecal excretion of PnCDF and HxCDFs in Yusho patients was about 23 times and 17 times each higher than that in normal controls. The fecal excretion of PCBs in Yusho patients and normal controls was 400 +/- 430 ng/day and 150 +/- 39 ng/day, respectively, as mean +/- SE. In order to promote the excretion of these toxic chemicals in the stool of Yusho patients, the patients were continuously administered with cholestyramine, an anion exchange resin, at a dose of 4 g, 3 times a day, for 6 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunohistochemical localization of Na+, K(+)-ATPase and calmodulin in rat myocardium

The immunohistochemical localization of Na+, K(+)-ATPase and calmodulin was investigated in rat heart muscle using antiserum against the catalytic subunit of the human kidney Na+, K(+)-ATPase and bovine testis calmodulin at the electron microscopic level. Immunostaining for both Na+, K(+)-ATPase and calmodulin was noted on the plasma membrane and plasmalemmal vesicles of the vascular endothelium and cardiac muscle cells. Calmodulin was also detected in the cytoplasm. These immunohistochemical localizations were evaluated by immunoblot analyses. Such localization of Na+, K(+)-ATPase and calmodulin suggests that they may play an important role in the regulation of Na(+)-Ca++ exchange across the cell membrane.

[Polychlorinated dibenzo-p-dioxins in the subcutaneous adipose tissue of yusho patients]

The abdominal subcutaneous adipose tissues, the mother milk, and the blood samples of yusho patients were collected between 1986 and 1988, and analyzed for polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) by high resolution gas chromatography/high resolution mass spectrometry in selected ion monitoring mode. PCDDs and PCDFs were found all of the samples examined.: 1,2,3,7,8-Pentachlorodibenzo-p-dioxin (pentaCDD), 1,2,3,6,7,8-hexaCDD, octaCDD, 2,3,4,7,8-pentachlorodibenzofuran (pentaCDF), and 1,2,3,4,7,8- and 1,2,3,6,7,8-hexaCDF were detected. The levels of PCDDs was several times lower than those of PCDFs in all samples. The concentrations of PCDDs and PCDFs found in the fat of the mother milk were similar to those of the adipose tissues. On the other hand, the levels of PCDDs and PCDFs in the blood samples were several hundred times less than those of the adipose tissues.

[Statistical analysis of subjects with type A, BC and C pattern of blood PCB on GC]

Various combinations of measured data on PCBs, PCQs, and PCDFs in adipose tissue or blood were tested on its discriminating power between normal persons and persons poisoned by yusho oil. The most discriminative single parameter was concentration of PCDF in adipose tissue. Furthermore, discriminative power increased by using additional parameters.

[Polychlorinated dibenzofurans (PCDFs) in the subcutaneous adipose tissue of yusho patients and normal controls]

Polychlorinated dibenzofurans (PCDFs) are well known to be the toxic chemicals in both animal experiments and human studies. It is, therefore, important to determine the level of PCDFs still retained in patients for understanding relationship between the concentration of PCDFs and present symptoms of the disease. In this study, the abdominal subcutaneous adipose tissue of 18 yusho patients and those of 11 normal controls who were all of volunteers were collected, and their levels were determined by high resolution gas chromatography/high resolution mass spectrometry. Results obtained were as follows: The principal compounds detected in the adipose tissue of yusho patients were 2,3,4,7,8-pentachlorodibenzofuran (PenCDF), 1,2,3,4,7,8- and 1,2,3,6,7,8-hexachlorodibenzofuran (HCDF). The concentration of the compounds in 7 patients, wearing typical symptoms, from 160 to 3,000 ppt for 2,3,4,7,8-PenCDF, from 51 to 1,000 ppt for 1,2,3,4,7,8-HCDF, and from 16 to 220 ppt for 1,2,3,6,7,8-HCDF. In normal controls, 2,3,4,7,8-PenCDF was detected only in five samples at the low level of from 16 to 38 ppt. On an average, PCDF levels in in the typical 7 yusho patients and 11 normal controls were 1,900 ppt and 16 ppt, respectively. On the basis of the results, the concentrations of PCDF congeners in the adipose tissues of the typical 7 patients was 100 times higher than that of the normal controls. Hence, we consider that the present levels of PCDFs in the patients probably play an important role for the symptoms of the yusho.