[Congener specific determination of PCBs in human blood using gel permeation chromatography (GPC) and high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS)]

We studied the progressive analytical method for polychlorinated biphenyls (PCBs) in blood samples collected from Yusho patients. This study established a systematic procedure for determining both "total concentration of PCBs and their profiles" and "concentrations of mono-ortho PCBs as dioxin-like compounds", providing a significant index for diagnosis. The method we developed consists of a rapid clean-up using gel permeation chromatography (GPC) and sensitive identification with high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS). This method provides identification of all of PCB congeners typically detected in human blood samples, especially it is worth noting that nine significant congeners on Yusho diagnosis (IUPAC #105, #114, #118, #123, #153, #156, #157, #167, #189) were detected from a five-gram blood sample. Using the present method, we analyzed sixty-six individual blood samples collected during the annual Yusho inspection in the 2004, and could identified sixty-eight PCB isomers in all samples. As a result, ten patients were classified into pattern A, the typical Yusho pattern. The mean total PCB concentration of pattern A subjects was 2.95 ppb, while that of control subjects was 0.77 ppb, at whole blood basis respectively.

Contamination Levels of PCDDs, PCDFs and Co-PCBs in Commercial Baby Foods in Japan

To examine dioxin contamination in commercial baby foods in Japan, congener analyses of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and coplanar polychlorinated biphenyls (Co-PCBs) were performed on 102 varieties of baby foods obtained from supermarkets in 2001-2002. The toxic equivalent quantity (TEQ) levels for dioxins in samples ranged from < 0.001 to 0.135 pg-TEQ/g wet weight when undetected or trace levels of congeners were taken as zero. Among 102 samples tested, 26 samples exceeded 0.010 pg-TEQ/g. The highest TEQ value was for "sardine, vegetables" (0.135 pg-TEQ/g), followed by "Japanese radish (daikon), sardine" (0.080 pg-TEQ/g). Thus, dioxins were detected at low levels in baby foods containing animal products such as fishes and/or dairy products.

Pulsed wave Doppler tissue echocardiography assessment of the long axis function of the right and left ventricles during the early neonatal period

OBJECTIVE

To assess the long axis function of both ventricles during the early neonatal period by using pulsed wave Doppler tissue (PWDT) echocardiography.

DESIGN

PWDT echocardiography was recorded from the lateral sites of the mitral and tricuspid annuluses and the tip of interventricular septum in 130 neonates within 24 hours after birth (day 0 group), in 135 neonates 1-7 days after birth (day 1-7 group), and in 131 healthy children (children group).

RESULTS

Peak systolic motion velocity (Sw) of the three ventricular walls positively correlated with the number of days after birth (p < 0.005). Compared with the children group, in neonates Sw in the right ventricle and peak early diastolic motion velocity (Ew) and peak atrial systolic motion velocity in the interventricular septum were lower than in the remaining two walls (p < 0.0005, p < 0.0001, and p< 0.0001, respectively). Although peak mitral and tricuspid flow velocities during early diastole (E) correlated with the number of hours after birth in the day 0 group, there was no significant change in the Ew of either ventricle. The E:Ew ratio of both ventricles was significantly higher in both neonate groups than in the children group (p < 0.001). The E:Ew ratio of the left ventricle was higher in the day 0 group than in the day 1-7 group (p < 0.005).

CONCLUSIONS

The two ventricles differ in their normal PWDT echocardiographic values and in the parameter change after birth during the early neonatal period, which may reflect differences in ventricular adaptation after birth.

Frequency of SCEs in Japanese infants lactationally exposed to organochlorone pesticides

Changes in the frequency of sister chromatid exchanges (SCEs) in cultured mammalian cells have been considered as indices to the synthetic and sharp genotoxic and clastogenic potencies. Frequency of SCEs in cultured lymphocyte obtained from infants postnatal of around ten months was examined to evaluate the genotoxic or clastogenic potency of lactational exposures to some organochlorine pesticides such as HCHs, DDT and chlordane in this study. Frequency (median, min.-max.) of SCEs as the control culture treated with the solvent, DMSO, alone (SCE control) was 8.0/cell, 6.5-12.4/cell, that as the culture treated with 7,8-benzoflavone (SCEANF) was 11.8/cell, 9.1-15.6/cell and the difference between SCEANF and SCEcontrol, that is, delta SCEs was 3.9/cell, 0.2:7.2/cell. Lactational exposures (median, min.-max.) to the three organochlorine pesticides were as follows: HCHs; 341 mg/kg body weight, 43-1449 mg/kg body weight, DDT; 272 mg/kg body weight, 33-1361 mg/kg body weight and chlordane; 69 mg/kg body weight, 13-379 mg/kg body weight. The median exposure level to chlordane through the breast milk was one fourth to one fifth times lower than that to HCHs or DDT and probably due to such small amounts of it's intake, we could not find any correlation of chlordane with frequencies of SCEcontrol, SCEANF and delta SCEs in cultured lymphocytes of Japanese infants postnatal of about ten months. In the meantime, frequencies of SCEcontrol and SCEANF showed increasing and decreasing tendencies with the increasing exposure to DDT and also HCHs through the breast milk. In consequence, the frequency of delta SCEs was significantly lowered. Therefore, lactational exposure to DDT and HCHs seemed to elicit some genotoxic or clastogenic effects on Japanese general infants at ages of around the months. These compounds were also considered rather potent S-dependent clastogens than non-S-dependent ones. So, further detailed studies are needed not only to get conclusive findings but also from this viewpoint.

[Follow-up survey of dioxins in the blood of Yusho patients (in 2001)]

Follow-up survey of the blood concentration of polychlorinated dibezo-p-dioxin (PCDDs), polychlorinated dibenzofuran (PCDFs), Non-ortho-coplaner PCBs (Non-Co-PCB), and Mono-ortho-coplaner PCBs (Mo-Co-PCB) in Yusho patients is very important for their health control. We determined the blood concentration of these dioxin-like isomers in 78 blood samples collected in 2001 using by a high-resolution gas chromatograph/high-resolution mass spectrometer (HRGC/HRMS) equipped with a solvent-cut large volume injection system (SCLV). The accelerated solvent extraction (ASE) method was employed for the treatment of blood samples. The method employed here can allow a reduced amount of blood collecting from Yusho patients compared with the conventional method. In typical Yusho patients (Group A of PCB pattern), the mean TEQ concentrations of PCDDs, PCDFs, Non-Co-PCBs, and Mono-Co-PCBs in blood collected in 2001 were 36, 260, 9.3, and 64 pg-TEQ/g lipid, respectively. As well, the toxic contribution of PCDDs, PCDFs, Non-Co-PCBs, and Mono-Co-PCBs in typical Yusho patients (Group A of PCB pattern) were 10, 70, 3, and 17% of the total TEQ value, respectively. The toxic contribution rate of PCDFs TEQ was still at high levels in relation to total TEQ in typical Yusho patients as mention above. The Yusho patients showing B pattern also had the same A pattern contribution rate. In the patients of group C, however, the mean blood levels of dioxin TEQ in 2001 was two times those of the normal controls determined in 2000 in Fukuoka prefecture. As well, the contribution rates were similar to those of normal subjects, although some patients in this group showed a high toxic contribution rate of PCDFs TEQ in relation to total TEQ. Thirty-three years had passed since the Yusho accident, and the total blood concentrations of PCDFs in the blood of Yusho patients were still higher than those of normal subjects. Among the different groups of PCB patterns, the concentration of 2,3,4,7,8-PeCDF, 1,2,3,4,7,8-HxCDF and 1,2,3,6,7,8-HxCDF showed significant differences. These findings indicate that these isomers are not metabolized in the human body since traces of them continued to be detected in these patients since they had been contaminated by the rice oil in the original incident.

[Equality as Yusho diagnosis indices between blood PCB constitution data from using a conventional analytical method and a PCB isomer specific analytical method]

This paper reports that we can replace a conventional PCB analytical method with an isomer specific analytical method in Yusho diagnosis. The authors analysed 109 blood samples from people who had the 2002 annual inspection for Kanemi rice oil poisoning using both methods. The data from these methods were compared and proved to be almost the same in the so-called "PCB pattern" which has been adopted as a Yusho diagnosis index since early 1970s.

Autoimmune hepatitis following allogeneic PBSCT from an HLA-matched sibling

A 7-year-old boy with acute lymphoblastic leukemia (ALL) in second remission received an allogeneic PBSCT from his HLA-matched sister. Acute grade II graft-versus-host disease (GVHD) resolved with corticosteroids. Chronic GVHD in the skin and oral mucosa at around day 60 responded to corticosteroids and cyclosporin A. At 6 months after the transplant, he developed hepatic dysfunction with elevated serum transaminases and gamma-globulin. Liver biopsy revealed chronic inflammation with lymphocytes and plasma cells in portal areas without destruction of bile ducts, suggesting autoimmune hepatitis. While rare, autoimmune hepatitis should be considered a potential long-term complication in patients with hepatic dysfunction in the late post-transplant phase.

SOCS-1 participates in negative regulation of LPS responses

SOCS-1 is a negative regulatory molecule of the JAK-STAT signal cascade. Here, we demonstrate that SOCS-1 is a critical downregulating factor for LPS signal pathways. SOCS-1 expression was promptly induced in macrophages upon LPS stimulation. SOCS-1-deficient mice were highly sensitive to LPS-induced shock and produced increased levels of inflammatory cytokines. Introduction of SOCS-1 inhibited LPS-induced NF-kappaB and STAT1 activation in macrophages. Furthermore, LPS tolerance, a refractory state to second LPS stimulation, was not observed in SOCS-1-deficient mice. These results suggest SOCS-1 as an essential, negative regulator in LPS responses that protects the host from harmful overresponses to LPS and may provide new insight into the endotoxin-induced fatal syndrome that occasionally occurs following infection.

Decrease in circulating hematopoietic progenitor cells by trapping in the pulmonary circulation

BACKGROUND

When stem-cell grafts are infused into the venous circulation and stem/progenitor cells egress from BM, pulmonary capillary beds are the first microcirculation site that they encounter. This provides the potential for circulating progenitor cells to be trapped in the pulmonary circulation.

METHODS

We compared the number of progenitor cells [CD34(+) cells, colony-forming unit-granulocyte-macrophage (CFU-GM), CD34(+) CD41(+) cells and CFU-megakaryocyte (CFU-meg)] and their expression of cell-adhesion molecules (CAM) in samples taken simultaneously from radial arteries and central veins of 21 patients following PBSC mobilization.

RESULTS

The mean (+/- SD) frequency of progenitor cells in the radial arteries was reduced to 79% +/- 25% for CD34(+) cells, 73% +/- 27% for CFU-GM, 77% +/- 25% for CD34(+) CD41(+) cells and 70% +/- 29% for CFU-meg of the number in the central veins. This suggests that some progenitor cells might be trapped in the lung. No association between progenitor-cell expression of CAM and pulmonary trapping was observed.

DISCUSSION

Our data demonstrate pulmonary trapping of PBSC during mobilization, suggesting a potential inhibitory effect on PBSC harvest and medullary trafficking following graft infusion. However, the impact associated with pulmonary PBSC trapping may be negligible in the clinical setting if sufficient cells are infused.

An in vitro evaluation of four materials as barriers to coronal microleakage in root-filled teeth

AIM

To assess the ability of IRM, Coltosol, Vidrion R and Scotch Bond to seal the pulp chamber following root-canal treatment.

METHODOLOGY

Root-canal treatment was completed on 100 extracted human mandibular molars. The teeth were divided into five groups of 20 teeth each, one group for each barrier material and one control group without barrier material. Two millimetres of the restorative material was placed on the pulp chamber floor. The teeth were thermocycled and evaluated for microleakage using India ink. Specimens were cleared and measurements made to the maximum point of dye penetration. The mean dye penetration for each group was compared by the Kruskal-Wallis test.

RESULTS

All groups showed dye penetration. Coltosol and IRM sealed significantly better than the other groups, preventing the coronal leakage in 84% and 75% of the specimens, respectively. Scotch Bond exhibited the highest leakage (54% of specimens with dye penetration), which did not differ significantly from the positive control group (62% with dye penetration).

CONCLUSIONS

None of the materials were able to prevent microleakage in all specimens. Vidrion R and Scotch Bond demonstrated the poorest results when used as barriers to coronal microleakage, whilst IRM and Coltosol were significantly better in preventing microleakage.

Levels and tissue-dependent distribution of dioxin in Japanese domestic leafy vegetables--from the 1999 national investigation

In 1999, Japanese domestic leafy vegetables were successively investigated for levels of dioxins, including 17 dibenzo-p-dioxins/dibenzofurans (PCDD/Fs), four non-ortho co-planar PCBs (co-PCBs) and eight mono-ortho co-PCBs, all of which had been assigned toxic equivalency factors (TEFs) by WHO in 1997. The mean levels of dioxins in the edible portions were 0.07 (0.09) pg TEQ/g in spinach, 0.13 (0.14) pgTEQ/g in garland chrysanthemum, 0.01 (0.04) pg TEQ/g in mitsuba (marsh parsley) and 0.01 (0.03) pg TEQ/g in chingentsuai (Brassica Campestris var. chinesis), when non-detects were set to zero (and set to half the limit of detection). In order to understand the dioxin pollution of leafy vegetables in detail, a further investigation of dioxin levels in the tissues of spinach was conducted. As a result, the dioxin levels in the leaves were found to be higher than those in the stem and red collar, but they were much lower than those found in the primary and secondary roots, which are considerably affected by the soil, which is recognized as a sink of airborne dioxins. The dioxin levels in edible portions (leaves, stem and red collar) were obviously lower than those in non-edible portions (primary and secondary roots). In addition, from the finding that several lower-chlorinated PCDD/Fs and co-PCBs, namely 2,3,7,8-TCDD/F, 1,2,3,7,8-PeCDD, 1,2,3,7,8/2,3,4,7,8-PeCDFs, 1,2,3,7,8,9-HxCDD, 1,2,3,4,7,8-/1,2,3,6,7,8-HxCDFs, 3,3',4,4'-TCB, 2,3,3',4,4'-/2,3',4,4',5-PeCBs, and 2,3',4,4',5,5'-HxCB, were more highly represented in the dioxins in the leaves than in those in the secondary roots, it was suggested that in leafy vegetables the deposition of gaseous, presumably moderately volatile dioxins in leaf wax is another pollution pathway in addition to the adhesion of dioxin-contaminated particles including soil.

Recent survey and effects of cooking processes on levels of PCDDs, PCDFs and Co-PCBs in leafy vegetables in Japan

We report here the latest levels of polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDD/Fs) and coplanar polychlorinated biphenyls (Co-PCBs) in leafy vegetables in Japan as well as the effect of cooking processes on the reduction of these contaminants. Three kinds of leafy vegetables ("komatsuna", lettuce and spinach) from seven districts in Japan in 1998 were analyzed for the 2,3,7,8-chlorine substituted PCDD/Fs and three non-ortho-PCBs (#77, 126 and 169). The mean total TEQ levels (using the WHO-TEFs) in the komatsuna, lettuce and spinach were 0.094, 0.025 and 0.196 pg/g fresh weight, respectively. The TEQ levels are dominated by 2.3,7,8-TCDD, 1,2,3,7,8-PeCDD, 2,3,4,7,8-PeCDF and 3,3',4,4',5-PeCB in many of the samples. For one of these isomers, the 2,4,7,8-PeCDF TEQ levels showed good correlation with the total TEQ levels in the samples (r = 0.957). This suggests that 2,3,4,7,8-PeCDF may be an indicator for dioxin contamination in the analysis of the leafy vegetables. Also, the effects of two cooking processes (washing and washing followed by boiling) on the dioxin levels in two types of spinach samples were investigated. On average, in both samples, the total concentrations of the PCDDs, PCDFs and Co-PCB were reduced to about 38%, 73% and 88% of the initial concentrations by washing. and to 21%, 35%, and 61% of the initial concentrations by washing followed by boiling. The total TEQ levels were reduced to about 30% of the initial TEQ levels by washing followed by boiling. Significant reductions in the TEQ levels were observed in the cooked samples. Thus, the cooking processes may reduce the risk of dioxin intake from the leafy vegetables.

Update of daily intake of PCDDs, PCDFs, and dioxin-like PCBs from food in Japan

Total diet study (TDS) samples of 14 food groups from 16 locations in Japan, collected in 1999 and 2000, were analyzed for polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (dioxin-like PCBs) to estimate the update of daily intake of these contaminants from food. The mean daily intake of toxic equivalency (TEQ) for an adult weighing 50 kg, calculated at non-detected isomer concentrations equal to zero (ND = 0), was estimated to be 2.25 pg TEQ/kg b.w./day. When non-detected isomer concentrations are assumed to be equal to half of the limits of detection (ND = 1/2 LOD), the mean daily intake was estimated to be 3.22 pg TEQ/kg b.w./day. These values were below the tolerable daily intake (TDI) of 4 pg TEQ/kg b.w. for PCDD/Fs and dioxin-like PCBs set in Japan. In both the estimates, the mean daily intakes were highest from fish and shellfish (76.9% at ND = 0 and 53.9% at ND = 1/2 LOD of the total TEQs), followed by those from meat and eggs (15.5% at ND = 0 and 11.7% at ND = 1/2 LOD of the total TEQs). Congener specific data revealed that these total TEQ levels were dominated by 1,2,3,7,8-PeCDD, 2,3,4,7,8-PeCDF and 3,3',4,4',5-PeCB in each case (71.7% at ND = 0 and 63.1% at ND = 1/2 LOD of the total TEQs). The dioxin-like PCBs (non-ortho and mono-ortho PCBs) accounted for about 50% of these total TEQs. These data will be very useful in the risk assessment of PCDD/Fs and dioxin-like PCBs from food in Japan.

Effects of cooking on concentrations of polychlorinated dibenzo-p-dioxins and related compounds in green leafy vegetable 'Komatsuna'

The effects of ordinary household cooking processes on concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (PCBs) (dioxins) were investigated in 'komatsuna', a green leafy vegetable popular in Japan. The concentrations of dioxins were compared using isomer-specific analyses of both uncooked and cooked edible parts of the plant. The mean total 2,3,7,8-chlorine substituted PCDD and PCDF concentrations were reduced from 46.53 pg/g and 0.714 pg/g to 8.301 pg/g and 0.210 pg/g by washing with tap water, and further reduced to 6.054 pg/g and 0.148 pg/g by subsequent boiling, respectively. The cooking processes markedly decreased the concentrations of PCDD/Fs, while having little effect on those of dioxin-like PCBs. The mean total concentration as 2,3,7,8-tetraCDD equivalents (TEQ) was reduced from 0.058 pgTEQ/g to 0.026 pgTEQ/g by washing with tap water and further reduced to 0.019 pgTEQ/g by subsequent boiling. These results suggest that ordinary cooking processes provide a means of reducing the level of dioxins in green leafy vegetables.

Mechanisms of the antimetastatic effect in the liver and of the hepatocyte injury induced by alpha-galactosylceramide in mice

The role of mouse liver NK1.1 Ag(+) T (NKT) cells in the antitumor effect of alpha-galactosylceramide (alpha-GalCer) has been unclear. We now show that, whereas alpha-GalCer increased the serum IFN-gamma concentration and alanine aminotransferase activity in NK cell-depleted C57BL/6 (B6) mice and B6-beige/beige mice similarly to its effects in control B6 mice, its enhancement of the antitumor cytotoxicity of liver mononuclear cells (MNCs) was abrogated. Depletion of both NK and NKT cells in B6 mice reduced all these effects of alpha-GALCER: Injection of Abs to IFN-gamma also inhibited the alpha-GalCer-induced increase in antitumor cytotoxicity of MNCS: alpha-GalCer induced the expression of Fas ligand on NKT cells in the liver of B6 mice. Whereas alpha-GalCer did not increase serum alanine aminotransferase activity in B6-lpr/lpr mice and B6-gld/gld mice, it increased the antitumor cytotoxicity of liver MNCS: The alpha-GalCer-induced increase in survival rate apparent in B6 mice injected intrasplenically with B16 tumor cells was abrogated in beige/beige mice, NK cell-depleted B6 mice, and B6 mice treated with Abs to IFN-gamma. Depletion of CD8(+) T cells did not affect the alpha-GalCer-induced antitumor cytotoxicity of liver MNCs but reduced the effect of alpha-GalCer on the survival of B6 mice. Thus, IFN-gamma produced by alpha-GalCer-activated NKT cells increases both the innate antitumor cytotoxicity of NK cells and the adaptive antitumor response of CD8(+) T cells, with consequent inhibition of tumor metastasis to the liver. Moreover, NKT cells mediate alpha-GalCer-induced hepatocyte injury through Fas-Fas ligand signaling.

SOCS-1/SSI-1-deficient NKT cells participate in severe hepatitis through dysregulated cross-talk inhibition of IFN-gamma and IL-4 signaling in vivo

Suppressor of cytokine signaling-1 (SOCS-1), also known as STAT-induced STAT inhibitor-1 (SSI-1), is a negative feedback molecule for cytokine signaling, and its in vivo deletion induces fulminant hepatitis. However, elimination of the STAT1 or STAT6 gene or deletion of NKT cells substantially prevented severe hepatitis in SOCS-1-deficient mice, while administration of IFN-gamma and IL-4 accelerated its development. SOCS-1 deficiency not only sustained IFN-gamma/IL-4 signaling but also eliminated the cross-inhibitory action of IFN-gamma on IL-4 signaling. These results suggest that SOCS-1 deficiency-induced persistent activation of STAT1 and STAT6, which would be inhibited by SOCS-1 under normal conditions, may induce abnormal activation of NKT cells, thus leading to lethal pathological changes in SOCS-1-deficient mice.

GATA DNA-binding protein expressed in mouse I-10 Leydig testicular tumor cells

A nuclear extract of the mouse I-10 Leydig tumor cell line was analyzed by gel mobility shift assay with a combination of antibodies for various mammalian GATA proteins. Antibodies for GATA-4 caused a super-shift of the DNA-protein complex, which is formed through GATA-4 binding to an oligonucleotide with a typical GATA motif, while ones for GATA-1, GATA-2, GATA-3, and GATA-6 did not. These results indicated that I-10 cells express GATA-4 protein. Western blotting analysis of cellular proteins also demonstrated the presence of GATA-4 protein, the size of which corresponds to that of the rat orthologous protein transiently expressed in Cos-1 cells. A significant level of GATA-4 expression in I-10 cells would be advantageous for studying the roles of this protein, especially in view of gonadal function. We further examined the binding site preference of GATA-4 expressed in I-10 cells. GATA-4 showed broad sequence specificity similar to GATA-6, the order of binding core site preference being GATA > GATT > GATC, and adenine was favored on both sides of the core for strong binding. Thus the conserved zinc finger domain of GATA proteins is suggested to contribute to the binding sequence preference. GATA-4 expressed in I-10 cells was not susceptible to proteolysis coupled with cAMP signaling.

[Follow-up survey of dioxins in the blood of Yusho patients (in 1998-1999)]

Follow-up survey of the blood concentration of PCDDs, PCDFs and non-ortho-chlorine substituted PCBs in Yusho patients is very important for their health control. We determined the blood concentration of these dioxin isomers in 119 blood samples collected in 1998 and 1999 using by a high-resolution gas chromatograph/high-resolution mass spectrometry (HRGC/HRMS). Thirty years had passed since the Yusho occurrence, and the total blood concentrations of PCDFs in the blood of Yusho patients were still as high as ever, except the patients with the PCB pattern C. Among the different groups of PCB patterns, the concentration of 2,3,4,7,8-PeCDF, 1,2,3,4,7,8-HxCDF and 1,2,3,6,7,8-HxCDF showed significant differences, excluding the group BC because of the small number of cases. The findings indicate that these isomers are not decomposed in human body since they had highly contaminated the causal rice oil at the onset. In typical Yusho patients (Group A of PCB pattern), the mean TEQ concentrations of PCDDs, PCDFs and non-ortho-chlorine substituted PCBs in the blood collected in 1998 were 21, 206, and 14 pg-TEQ/g lipid, respectively, and in 1999, 30, 308 and 14 pg-TEQ/g lipid, respectively. The toxic contribution rate of PCDFs TEQ was still at high levels for total TEQ in both years. The patients of the group C, however, the mean blood levels of the dioxins TEQ in 1998 and 1999 did not differ from those of the normal controls determined in 1996 although some patients in this group showed a high toxic contribution rate of PCDFs TEQ for total TEQ. We will try the PCB isomer specific analysis of the Yusho patients blood, and will investigate the difference from normal controls blood.

Antitumor activity of alpha-galactosylceramide, KRN7000, in mice with the melanoma B16 hepatic metastasis and immunohistological study of tumor infiltrating cells

Liver metastasis of primary tumors is clinically a major problem. We examined the antitumor activity of KRN7000, an alpha-galactosylceramide, in mice with liver metastasis of the B16 melanoma. KRN7000 significantly inhibited tumor growth in the liver, and its potency was similar to that of interleukin-12. The KRN7000 administration resulted in a high percentage of cured mice, which acquired tumor-specific immunity. To study what kinds of antitumor effector cells participated in killing tumor cells, we then performed immunohistological analysis of tumor-infiltrating cells, and found that KRN7000 induced marked invasion of NK1.1+ cells, CD8+ cells, and F4/80+ cells (macrophages) into B16 tumor nodules. In addition, it appeared that KRN7000-treated, liver-associated macrophages possessed strong lytic activity against tumor cells. These results suggest that NK cells, NK1.1+ T (NKT) cells, cytotoxic T lymphocytes, and macrophages play an important role in killing tumor cells in the liver, and that KRN7000 may be useful for the treatment of cancer liver metastasis.

Identification of breast cancer resistant protein/mitoxantrone resistance/placenta-specific, ATP-binding cassette transporter as a transporter of NB-506 and J-107088, topoisomerase I inhibitors with an indolocarbazole structure

The antitumor drugs NB-506 and J-107088 are potent topoisomerase I inhibitors with an indolocarbazole structure. To clarify the factors involved in resistance to these drugs, we established two NB-506-resistant mouse fibroblast cell lines (LY/NR1 and LY/NR2), a human colon carcinoma cell line (HCT116/NR1), and a lung cancer cell line (PC13/NR1). These cell lines were highly resistant to NB-506 and J-107088, and LY/NR2 cells showed markedly reduced accumulation and strong efflux of NB-506, suggesting activation of a drug efflux pump in the resistant cells. To identify the molecules responsible for efflux of NB-506, we compared the gene expressions of the mouse resistant LY/NR1 cells, LY/NR2 cells, and their parental cells by oligonucleotide microarray. Of 34,020 genes analyzed, we found that an ATP-binding cassette transporter BCRP/MXR/ABCP (BCRP) gene showed the highest increase in the expression, 31-fold higher in the LY/NR2-resistant cells than in their parental cells. The selective overexpression of this gene was also detected in the two human resistant cell lines, suggesting the involvement of breast cancer resistant protein (BCRP) in the resistance and efflux of these drugs. Finally, a PC-13 cell line transfected with BCRP expression vector displayed 22- and 17-fold resistance to NB-506 and J-107088 and enhanced efflux activity of J-107088. However, the transfectants were not resistant to mitoxantrone or topotecan, the drugs previously thought to be the substrates of BCRP. Thus, our study presents a novel mechanism of drug resistance mediated by BCRP.

Intense immunosuppression followed by purified blood CD34+ cell autografting in a patient with refractory juvenile rheumatoid arthritis

A 15-year-old boy with refractory juvenile rheumatoid arthritis (JRA) underwent intense immunosuppressive therapy followed by purified blood CD34+ cell autografting. He had been taking prednisolone (PDN) daily or every other day combined with methotrexate once a week to control the disease for 7 years. He suffered from psychological complications and a very short stature due to the adverse effects of these drugs. CD34+ cells were purified in bulk from G-CSF-mobilized PBSC using an Isolex 300. After the administration of cyclophosphamide (200 mg/kg) and anti-lymphocyte globulin (45 mg/kg), 3.6 x 10(6)/kg purified CD34+ cells were infused. His post-transplant course was uneventful except for herpes-zoster infection. He is now more than 1 year post transplant and has not taken any immunosuppressive medication. His rate of growth has increased (>10 cm/year) due to the effects of the cessation of PDN and the administration of recombinant human growth hormone (rGH), in contrast to the gain of 2 cm in the preceding 3 years with rGH treatment. Although the durability of this remission is unknown, intense immunosuppressive therapy followed by purified blood CD34+ cell autografting might be acceptable for adolescent patients with refractory JRA to achieve a drug-free period for physical and psychological maturation.

Signal transducer and activator of transcription (STAT)-induced STAT inhibitor 1 (SSI-1)/suppressor of cytokine signaling 1 (SOCS1) inhibits insulin signal transduction pathway through modulating insulin receptor substrate 1 (IRS-1) phosphorylation

Signal transducer and activator of transcription (STAT)-induced STAT inhibitor 1 (SSI-1) is known to function as a negative feedback regulator of cytokine signaling, but it is unclear whether it is involved in other biological events. Here, we show that SSI-1 participates and plays an important role in the insulin signal transduction pathway. SSI-1-deficient mice showed a significantly low level of blood sugar. While the forced expression of SSI-1 reduced the phosphorylation level of insulin receptor substrate 1 (IRS-1), SSI-1 deficiency resulted in sustained phosphorylation of IRS-1 in response to insulin.Furthermore, SSI-1 achieves this inhibition both by binding directly to IRS-1 and by suppressing Janus kinases. These findings suggest that SSI-1 acts as a negative feedback factor also in the insulin signal transduction pathway through the suppression of IRS-1 phosphorylation.

Defective thymocyte development and perturbed homeostasis of T cells in STAT-induced STAT inhibitor-1/suppressors of cytokine signaling-1 transgenic mice

Previous experiments have shown that STAT-induced STAT inhibitor-1 (SSI-1; also named suppressors of cytokine signaling-1 (SOCS-1) or Janus kinase binding protein) is predominantly expressed in lymphoid organs and functions in vitro as a negative regulator of cytokine signaling. To determine the function of SOCS-1 in vivo, we generated SSI-1 transgenic mice using the lck proximal promoter that drives transgene expression in T cell lineage. In thymocytes expressing SSI-1 transgene, tyrosine phosphorylation of STATs in response to cytokines such as IFN-gamma, IL-6, and IL-7 was inhibited, suggesting that SSI-1 suppresses cytokine signaling in primary lymphocytes. In addition, lck-SSI-1 transgenic mice showed a reduction in the number of thymocytes as a result of the developmental blocking during triple-negative stage. They also exhibited a relative increase in the percentage of CD4+ T cells, a reduction in the number of gammadelta T cells, as well as the spontaneous activation and increased apoptosis of peripheral T cells. Thus, enforced expression of SSI-1 disturbs the development of thymocytes and the homeostasis of peripheral T cells. All these features of lck-SSI-1 transgenic mice strikingly resemble the phenotype of mice lacking common gamma-chain or Janus kinase-3, suggesting that transgene-derived SSI-1 inhibits the functions of common gamma-chain-using cytokines. Taken together, these results suggest that SSI-1 can also inhibit a wide variety of cytokines in vivo.

Low numbers of megakaryocyte progenitors in grafts of cord blood cells may result in delayed platelet recovery after cord blood cell transplant

Delayed platelet recovery is an inherent problem with cord blood cell transplantation (CBCT). To investigate this problem, the number of human megakaryocyte (MK) progenitor cells in cord blood (CB; n = 24) was measured and compared with that in G-CSF-mobilized peripheral blood stem cells (PBSC; n = 25). The median numbers of colony-forming units for MK (CFU-MK) that were detected by a serum-free assay system in CB and peripheral blood (PB) were 26 (range, 6-102)/10(5) nucleated cells (NC) and 37 (2-540)/10(5) mononuclear cells (MNC), respectively. The numbers of colony-forming units for granulocyte/macrophage (CFU-GM) were 88 (33-241)/10(5) NC in CB and 138 (6.3-1,250)/10(5) MNC in PB. The frequencies of CD34(+) cells in CB and PB were, respectively, 0.44% (0.10-1.07) and 0.98% (0.05-20.8). The numbers of CFU-MK in CB and PBSC were correlated with those of CD34(+) cells. The estimated number of infused CFU-MK in CBCT was 1/15 that of PBSC transplantation (PBSCT), based upon the above data and the widely used standard doses for both types of transplants. Further, the numbers of infused CFU-MK in patients who received allogeneic PBSCT at our institute were inversely correlated with the speed of platelet recovery. These data indicate that delayed platelet recovery after CBCT is simply due to the low number of CFU-MK contained in grafts.

Cloning and sequence analysis of cDNA coding for a lectin from Helianthus tuberosus callus and its jasmonate-induced expression

Two lectins (designated as HTA I and HTA II) that seemed to be isolectins were found in Helianthus tuberosus callus. cDNA encoding HTA I was isolated from a ZAP Express expression library by immunoselection by using the anti-HTA antiserum. The sequence of this cDNA consisted of 432 bp nucleotides coding for a polypeptide of 143 amino acid residues (Mr, 15,314). When introduced into E. coli, the cDNA directed the synthesis of active HTA I as indicated by the hemagglutination activity. The deduced amino acid sequence showed homology with some lectins and jasmonate-induced proteins. When callus was cultured in the presence of methyl jasmonate (MeJA), the hemagglutination activity increased in a dose-dependent manner. The levels of expression of the HTA protein and of the corresponding mRNA also increased in the treated callus. In view of these results, HTA I is considered to be a jasmonate-induced protein.