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H Fujiwara

Publications and source records attributed to H Fujiwara.

At least 37 records · Page 2Linked to original sources
PubMed2003

Down-regulation in human cancers of DRHC, a novel helicase-like gene from 17q25.1 that inhibits cell growth.

Frequent observations of allelic loss in chromosomal band 17q25.1 in a variety of human cancers have suggested that one or more tumor suppressor genes are normally present in this region. Moreover, a locus responsible for hereditary focal non-epidermolytic palmoplantar keratoderma (tylosis oesophageal cancer; TOC), a condition associated with esophageal cancer, has been mapped to the same band. During efforts to sequence, by shot-gun methods, a 1 Mb target region that we had defined as the DNA segment harboring the putative tumor suppressor gene(s) involved in these events, we identified a novel cDNA, DRHC (down-regulated in human cancers), that showed reduced expression in 28 of 95 (29%) cell lines derived from a variety of human cancers. The full-length cDNA, 6275 bp long, was expressed predominantly in thymus and brain. The predicted 1942-amino-acid product exhibited significant sequence homology to yeast enzymes belonging to the DEAD-helicase superfamily, and appeared to be a Uvr/Rep helicase with a DEXDc consensus domain. Transfection of a DRHC expression vector inhibited growth of cancer cells in liquid medium or soft agar. The results suggest that loss of expression of DRHC may play a role in human carcinogenesis.

Blotting, Northern↗
PubMed2003

Superior antitumour activity of S-1 in tumours with a high dihydropyrimidine dehydrogenase activity.

To elucidate the mechanism of the enhanced antitumour activity of S-1 (1 M tegafur, 0.4 M 5-chloro-2, 4-dihydroxypyridine, and 1 M potassium oxonate) in terms of the phosphorylation and degradation pathways of 5-fluorouracil (5-FU) metabolism, we investigated tumoral thymidylate synthase (TS) content, dihydropyrimidine dehydrogenase (DPD) activity, the TS inhibition rate (TS-IR), and 5-FU incorporated into RNA (F-RNA) in four human gastric cancer xenografts (MKN-28, MKN-74, GCIY and GT3TKB) and compared the results obtained with S-1 with those obtained with 5-FU and UFT (1 M tegafur, 4 M uracil). 5-FU was administered intraperitoneally (i.p.) to mice at a dose of 50 mg/kg, three times, on days 0, 4 and 8. S-1 and UFT were administered orally at doses of 10 and 24 mg/kg, respectively, once a day, for 9 consecutive days. Antitumour activity was evaluated as the maximum inhibition of tumour growth in each animal. S-1 showed a better antitumour activity than 5-FU and UFT in tumours with a high DPD activity (GCIY and GT3TKB). There were inverse correlations between the antitumour activity and both TS content and DPD activity in the 5-FU and UFT groups. However, no such correlations were observed in the S-1 group. In GCIY and GT3TKB xenografts, TS-IR was significantly higher in the S-1 group than in the 5-FU or UFT groups. In GT3TKB xenografts, the F-RNA level was significantly higher in the S-1 group than in the 5-FU or UFT groups. The superior cytotoxicity of S-1 appears to be attributable to both an increased inhibition of DNA synthesis and an enhanced blockade of RNA function against tumours with a high DPD activity.

Animals↗
PubMed2003

Tissue-restricted T cell alloresponses across HLA barriers: selection and identification of leukemia-restricted CTL in HLA-mismatched stimulator-responder pairs.

Exploiting the graft-versus-leukemia (GVL) effect in mismatched transplants requires its separation from graft-versus-host disease (GVHD). We generated leukemia-specific cytotoxic T lymphocytes (CTL) in three haplotype-mismatched, two class I-mismatched and two single HLA-A locus-matched stimulator-responder pairs. Six patients with chronic myelogenous leukemia and one patient with acute myeloid leukemia transformed from MDS were studied. CTL generated after 10 days stimulation with unselected leukemic peripheral blood mononuclear cells inhibited leukemic CFU-GM colony growth (>85% at 10:1 effector:target ratio) with no third-party colony inhibition. In five pairs, responders were cultured separately with leukemia cells, PHA-B or LCL from the stimulator. After 2-4 restimulations, the T cell repertoire was examined by flow analysis using Vbeta-specific antibodies. Test cultures (but not controls) showed preferential expansion of 1-4 Vbeta families either common to two or more stimulators or unique to a particular stimulator. Notably, we elicited leukemia-specific TCR Vbeta expansions on four out of five occasions. In two pairs, responder cells selected for the appropriate leukemia-specific Vbeta family were shown to have leukemia-specific cytotoxicity. These leukemia-restricted T-cells were CD8+ or CD4+ and CD25+ or CD57+. The results support the development of strategies to selectively deplete GVHD and conserve GVL reactivity in mismatched transplants.

Bone Marrow Transplantation↗
PubMed2003

Treatment for ovarian hyperstimulation syndrome using an oral dopamine prodrug, docarpamine.

Dopamine treatment constitutes a major advance towards the management of severe ovarian hyperstimulation syndrome (OHSS) by causing renal and mesenteric vasodilatation as well as diuretic and positive inotropic actions. Docarpamine, an oral dopamine prodrug, is converted into dopamine after enteral administration, and the generated dopamine causes renal vasodilatation and diuresis. The purpose of this study was to assess whether docarpamine had beneficial effects in patients with OHSS. Twenty-seven patients, hospitalized because of OHSS and refractory to the initial therapy with intravenous albumin, were treated by docarpamine, after informed consent had been obtained. A 750-mg tablet of docarpamine was taken every 8 h. In some cases, the plasma levels of free dopamine were measured. The daily urinary outputs before and 1, 2, 3 and 4 days after the docarpamine treatment were 839 +/- 424 ml, 1121 +/- 608 ml, 1168 +/- 504 ml, 1325 +/- 815 ml and 1133 +/- 509 ml, respectively. There were significant differences between the first and each of the others (p < 0.05). In 19 (86.4%) of 22 patients treated, clinical symptoms associated with ascites were gradually improved after administrating docarpamine. The plasma free dopamine concentration rose to as high as 55.9 +/- 33.2 mg/ml during the first hour, which corresponded to the usual intravenous drip infusion treatment with dopamine. Moreover, there were no major adverse effects of docarpamine in this study. This was the first demonstration of docarpamine treatment in patients with intravenous albumin-resistant OHSS. Although no effect was seen in pregnant women, diuresis was increased in some women, and ascites decreased. These findings indicate that oral docarpamine administration could be one of the options in the management of patients with OHSS using dopamine therapy.

Adult↗
PubMed2003

Secretory IgA level in pharyngeal mucous of infants with different feeding methods at the age of four to eight weeks.

The stimulating effect of human breast milk on the mucosal immunological development of recipient infant has been speculated. The objective of this study was to clarify the influence of breast feeding on the level of secretory IgA (sIgA) of infants. The level of sIgA in pharyngeal mucous among 79 healthy infants aged 4-8 weeks with different feeding methods was estimated. The concentrations of sIgA and protein were measured after the mucous absorbed by the throat swab was emulsified in saline. The level of sIgA was expressed as a percentage of the total protein content (sIgA % protein). The difference of the mean sIgA % protein was not significant among infants with different feeding methods. The results suggest that breast milk does not influence the sIgA levels of infant. Breast feeding may promote specific sIgA production without raising the total level of sIgA.

Bottle Feeding↗
PubMed2002

Cimetidine modulates the antigen presenting capacity of dendritic cells from colorectal cancer patients.

Cimetidine, a H(2) receptor antagonist, has been reported to improve survival in gastrointestinal cancer patients. These effects have largely been attributed to the enhancing effects of cimetidine on the host's antitumour cell-mediated immune response, such as inhibition of suppressor T lymphocyte activity, stimulation of natural killer cell activity and increase of interleukin-2 production from helper T lymphocytes. We conducted an in vitro study on the effects of cimetidine on differentiation and antigen presenting capacity of monocyte-derived dendritic cells from advanced colorectal cancer patients and normal controls. As a result, an investigation of expression of surface molecules associated with dendritic cells by flow cytometric analyses showed that cimetidine had no enhancing effect on differentiation of dendritic cells from cancer patients and normal controls. An investigation of [(3)H]thymidine incorporation by allogeneic mixed lymphocyte reactions revealed that cimetidine increased the antigen presenting capacity of dendritic cells from both materials. Moreover, a higher antigen presenting capacity was observed in advanced cancer patients compared to normal controls. These effects might be mediated via specific action of cimetidine and not via H(2) receptors because famotidine did not show similar effects. Our results suggest that cimetidine may enhance the host's antitumour cell-mediated immunity by improving the suppressed dendritic cells function of advanced cancer patients.

Adult↗
PubMed2002

Role of thymidine phosphorylase and dihydropyrimidine dehydrogenase in tumour progression and sensitivity to doxifluridine in gastric cancer patients.

This study was designed to investigate the role of thymidine phosphorylase (TP) and dihydropyrimidine dehydrogenase (DPD) on tumour progression and sensitivity to 5'-deoxy-5-fluorouridine (5'-DFUR). Tumour tissue was obtained from surgically resected samples from 93 patients with primary gastric cancer. Tumour TP and DPD expression levels were determined by the enzyme-linked immunosorbent assay (ELISA) system and compared with several clinicopathological factors and in vitro sensitivity to 5'-DFUR. DPD showed no correlation with any clinicopathological factors. However, the TP level was significantly correlated with the depth of tumour, lymphatic invasion and venous invasion. In comparison with 5'-DFUR sensitivity, there was a weak inverse correlation between the DPD level and the sensitivity to 5'-DFUR (r(s)=-0.361). Furthermore, the TP/DPD ratio showed a significant correlation with 5'-DFUR sensitivity (r(s)=0.634). In a subgroup of patients with postoperative 5'-DFUR administration, the survival rate was significantly better in patients with a high TP/DPD ratio (n=8) than in those with low TP/DPD ratio (n=14) (P=0.0140). These results suggest that sensitivity to 5'-DFUR is predictable by measurement of both TP and DPD levels.

Adult↗
PubMed2002

Ecdysteroid-dependent expression of a novel cuticle protein gene BMCPG1 in the silkworm, Bombyx mori.

When insects molt, the exoskeleton is renewed under the controls of insect hormones via the biosynthesis and degradation of cuticle proteins. To understand the hormonal control of cuticle formation, we used the differential display method to look for stage-specific cuticle genes, and identified a novel cDNA named Bombyx mori Cuticle Protein GlyGlyTyr-repeat 1 (BMCPG1). Expression of BMCPG1 mRNA peaked sharply immediately after a pulse of ecdysteroid during the fourth molt and pre-pupal stages, concurrent with the expression of genes for FTZF1 and dopa decarboxylase. BMCPG1 was expressed only in the epidermis, but not in any other tissue. We cultured the larval epidermis and found that BMCPG1 expression is not induced by the continuous presence of ecdysteroid. Removal of ecdysteroid from the medium, which constitutes a pulse treatment, is required for the induction of BMCPG1 transcription. These results explain well the stage-specific expression of BMCPG1 by ecdysteroid in vivo. Based on its expression patterns and unique structure, we propose that BMCPG1 may be a novel component of epicuticle of B. mori, and is probably involved in cross-linking of proteins via its GGY repeats.

Amino Acid Sequence↗
PubMed2002

Identification and characterization of genes abnormally expressed in wing-deficient mutant (flügellos) of the silkworm, Bombyx mori.

The wing-deficient mutant, flügellos (fl), of the silkworm lacks four wings in the pupa and the adult, due to aberrant wing morphogenesis during metamorphosis. To elucidate the mechanisms of wing-specific deficiencies in the fl mutant, we used mRNA differential display and identified five genes abnormally expressed in the fl wing discs. Northern blot and RT-PCR analyses revealed that four genes were overexpressed, but the fifth one was not transcribed in the fl wing discs. The expression level of ribosome-associated protein p40 in the fl wing discs was elevated approximately 10 times compared to the wild-type (WT) discs. Another overexpressed gene CB10 encodes a novel wing-specific protein with a putative zinc-finger motif. Overexpression of two components of extracellular matrix, cuticle protein 18 (BMCP18) and a fibrillin-like protein AD10, may result in the abnormal wing morphogenesis in the fl mutant. In contrast, a novel member of multifunctional Ca2+-binding protein annexins, designated as annexin b13 (Anx b13), was expressed dominantly in the wing discs of WT but completely repressed in the fl tissues. Strong expression of Anx b13 in wing discs during the fourth and fifth instar indicates that ANX B13 plays an important role in wing morphogenesis.

Amino Acid Sequence↗
PubMed2002

Development of a gamma ray monitor using a CdZnTe semiconductor detector.

The aim of this study was to develop a new X ray and gamma ray monitor using the CdZnTe semiconductor detector, which has high sensitivity at room temperature. The pulse height spectra and the detection efficiencies of a 10 mm x 10 mm by 2 mm thick CdZnTe detector were measured in the energy range of 10 keV to 1.8 MeV by using monoenergetic X ray and gamma ray sources. The measured results showed very good agreement with the results calculated using the EGS4 Monte Carlo code taking into account the charge collection efficiency in the detector. By using two CZT detectors of 10 mm x 10 mm x 2 mm and 3 mm x 3 mm x 2 mm coupled with a filter, the weighted sum of a few energy channels with different cut-off energies was finally found to achieve a flat energy response with an equivalent dose (counts per microSv) within +/-30% or +/- 10% deviation.

Cadmium↗
PubMed2002

Significant reduction of 125 I-meta-iodobenzylguanidine accumulation directly caused by 1-methyl-4-phenyl-1,2,3,6-tetrahydroxypyridine, a toxic agent for inducing experimental Parkinson's disease.

A significant reduction of cardiac 123I-meta-iodobenzylguanidine (MIBG) accumulation has been reported in patients with idiopathic Parkinson's disease. However, it is unclear whether this reduction in cardiac sympathetic nerve is caused primarily or secondarily to the degeneration of sympathetic nerve centres which occurs in Parkinson's disease. Therefore, we examined neuronal 125I-MIBG accumulation in mice hearts of an experimental Parkinson's disease model and in sympathetic cells without any neuronal innervation. Cardiac accumulation of 125I-MIBG was determined 4h after intravenous injection of 125I-MIBG in mice pretreated with 1-methyl-4-phenyl-1,2,3,6-tetrahydroxypyridine (MPTP), an inducer of Parkinson's disease. In an in vitro study, uptake of 125I-MIBG was determined in a cultured pheochromocytoma cell line (PC-12), which was pretreated with MPTP. MPTP reduced MIBG accumulation mainly in its neuronal component of mice hearts, suggesting that MPTP impairs cardiac sympathetic nerves to uptake MIBG. Application of MPTP also caused near-complete blockade of 125I-MIBG accumulation in PC-12 cells. In the experimental PD models, it was shown that neuronal accumulation of MIBG was impaired by the direct action of MPTP to the sympathetic cells. These findings support the idea that cardiac sympathetic nerves are primarily impaired in Parkinson's disease despite the presence or absence of systemic autonomic failure.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed2002

Potent apoptotic effects of saponins from Liliaceae plants in L1210 cells.

We isolated eight saponins, a hexacyclic lanosterol tetraglycoside (1), a 27-norlanosterol tetraglycoside (2) and six spirostanol oligoglycosides (3-8), from the plants of the family Liliaceae. In murine leukaemic L1210 cells, saponins 5 and 7 at a concentration of 1 microM showed potent cytotoxic activity and the activities were in the following decreasing order: 5, 7, 1, 3, 2, 8, 4, 6. At a concentration of 10 microM, not only 5 and 7 but also 3 and 8 markedly caused cell death. The flow cytometric analysis indicated that 7 and 8 caused a concentration- and time-dependent apoptosis of L1210 cells (EC50 value = approximately 5 microM). The morphological observation using a light microscope revealed that both 7 and 8 induced shrinkage in cell soma and chromatin condensation, suggesting apoptotic cell death. Moreover, in agarose gel electrophoretic analysis, a typical apoptotic DNA ladder pattern was observed after treatment with both 7 and 8. These results suggest that 7 and 8 caused the death of L1210 cells through the apoptotic process. These compounds may become powerful pharmacological tools for studying the molecular mechanism of apoptosis.

Animals↗
PubMed2001

A mandatory role for STAT4 in IL-12 induction of mouse T cell CCR5.

IL-12 was recently shown to induce CCR5 on TCR-triggered mouse T cells. Considering that STAT4 is the most critical of IL-12 signaling molecules, this study investigated the role for STAT4 in the induction of CCR5 expression. IL-12R was induced by stimulation with anti-CD3 plus anti-CD28 mAb similarly on T cells from wild-type (WT) and STAT4-deficient (STAT4(-/-)) mice, but the levels of IL-12R induced on IFN-gamma-deficient (IFN-gamma(-/-)) T cells were lower compared with WT T cells. Exposure of TCR-triggered WT T cells to IL-12 induced CCR5 expression. In contrast, TCR-triggered STAT4(-/-) T cells failed to express CCR5 in response to IL-12. IL-12 stimulation induced detectable albeit reduced levels of CCR5 expression on IFN-gamma(-/-) T cells. Addition of rIFN-gamma to cultures of IFN-gamma(-/-) T cells, particularly to cultures during TCR triggering resulted in restoration of CCR5 expression. However, CCR5 expression was not induced in STAT4(-/-) T cells by supplementation of rIFN-gamma. These results indicate that for the induction of CCR5 on T cells, 1) STAT4 plays an indispensable role; 2) such a role is not substituted by simply supplementing rIFN-gamma; and 3) IFN-gamma amplifies CCR5 induction depending on the presence of STAT4.

Animals↗
PubMed2001

Comparative metabolism, covalent binding and toxicity of BHT congeners in rat liver slices.

The metabolism, covalent binding and hepatotoxicity of butylated hydroxytoluene (BHT, 4-methyl-2,6-di-t-butylphenol) and two congeners (E-BHT, 4-ethyl-2,6-di-t-butylphenol; I-BHT, 4-isopropyl-2,6-di-t-butylphenol) were compared using precision-cut liver slices prepared from phenobarbital (PB)-treated male Sprague-Dawley rats. At equimolar concentrations (1 mM) BHT was the most toxic of the three compounds, causing an 80% decrease in cell viability over a 6 h incubation period. E-BHT was intermediate in toxicity while the isopropyl derivative was relatively nontoxic. Intracellular glutathione levels decreased prior to the onset of cytotoxicity. The cytochrome P450 inhibitor metyrapone completely inhibited the toxicity of all three compounds. The rates of metabolism of the three compounds to glutathione conjugates were compared in both PB-treated microsomes and PB-induced liver slices. In both models, the rate of formation was greatest for BHT, followed by E-BHT and I-BHT. Synthetic quinone methides (QMs) were prepared from each parent phenol and the rates of reactivity with three nucleophiles (water, methanol and glutathione) were compared. With each nucleophile, BHTQM was the most reactive, while I-BHTQM was the least reactive. Finally, covalent binding to protein was assessed in two ways. First, alkylation of an isolated model protein (bovine insulin) was measured in a microsomal enzyme activation system by mass spectrometry. Incubations with BHT produced the greatest extent of protein alkylation, followed by E-BHT, while no alkylation was observed with I-BHT. In the second system, covalent binding to cellular protein was assessed in rat liver PB microsomes and tissue slices by Western blotting using an antibody specific for the tert-butylphenol portion of the compounds. Binding was greatest for BHT, intermediate for E-BHT and could not be detected for I-BHT. The alkylation pattern for E-BHT was strikingly similar to that of BHT, suggesting that both compounds bound similar proteins. In summary, our results suggest that for hindered phenols such as BHT, increasing the length of the 4-alkyl substituent retards the rate of formation of reactive intermediates, significantly reduces the electrophilicity of the reactive intermediate, and greatly reduces the amount but not the selectivity of covalent binding to cellular protein, thereby reducing the toxicity of the parent compound.

Alkylation↗
PubMed2001

An absolute requirement for STAT4 and a role for IFN-gamma as an amplifying factor in IL-12 induction of the functional IL-18 receptor complex.

IL-12 and IL-18 are both proinflammatory cytokines that contribute to promoting Th1 development and IFN-gamma expression. However, neither IL-12R nor IL-18R is expressed as a functional complex on most resting T cells. This study investigated the molecular mechanisms underlying the induction of an IL-18R complex in T cells. Resting T cells expressed IL-18Ralpha chains but did not exhibit IL-18 binding sites as detected by incubation with rIL-18 followed by anti-IL-18 Ab, suggesting a lack of IL-18Rbeta expression in resting T cells. Although they also failed to express IL-12R, stimulation with anti-CD3 plus anti-CD28 generated IL-12R. Exposure of these cells to IL-12 led not only to up-regulation of IL-18Ralpha expression but also to induction of IL-18R binding sites on both CD4(+) and CD8(+) T cells concomitant with IL-18Rbeta mRNA expression. The IL-18 binding site represented a functional IL-18R complex capable of exhibiting IL-18 responsiveness. IL-12 induction of an IL-18R complex and IL-18Rbeta mRNA expression was not observed in STAT4-deficient (STAT4(-/-)) T cells and was substantially decreased in IFN-gamma(-/-) T cells. However, the failure of STAT4(-/-) T cells to induce an IL-18R complex was not corrected by IFN-gamma. These results indicate that STAT4 and IFN-gamma play an indispensable role and a role as an amplifying factor, respectively, in IL-12 induction of the functional IL-18R complex.

Adjuvants, Immunologic↗
PubMed2001

A role of interferon-gamma (IFN-gamma) in tumor immunity: T cells with the capacity to reject tumor cells are generated but fail to migrate to tumor sites in IFN-gamma-deficient mice.

IFN-gamma-deficient (IFN-gamma-/-) mice induce potent in vitro immune responses such as anti-allo mixed lymphocyte reaction and CTL responses, whereas they often fail to exhibit in vivo immunity. Here, we investigated whether there exists a defect in tumor rejection responses and if so, which process of responses is impaired. IFN-gamma-/- and wild-type (WT) BALB/c mice were immunized with attenuated syngeneic CSA1M tumor cells. The capacity of T cells to mediate tumor protection was examined in Winn assays to assess the growth of tumor cells admixed with tumor-sensitized T cells. Splenic T cells from both groups of mice exhibited comparable levels of tumor-neutralizing activity. When portions of immunized mice were directly challenged with viable tumor cells, tumor rejection was induced only in WT mice. CD4(+) and CD8(+) T-cell infiltration were observed at the site of tumor challenge in WT mice, whereas such a T-cell infiltration did not occur in IFN-gamma-/- mice. Similarly, splenic T cells from interleukin 12-treated CSA1M-bearing IFN-gamma-/- and WT mice neutralized tumor cells at comparable efficacies in Winn assays. However, the migration of these T cells to tumor masses and the resultant interleukin 12-induced tumor regression took place in WT mice, but neither intratumoral T-cell infiltration nor tumor regression occurred in IFN-gamma-/- mice. These results indicate a critical requirement for IFN-gamma in the process of inducing T-cell migration to tumor sites rather than of generating antitumor protective T cells.

Animals↗