Biomedical subjects

M Maeda

Publications and source records attributed to M Maeda.

At least 127 records · Page 7Linked to original sources

PubMed2001

Effects of lipopolysaccharide on a macrophage-like cell line (HS-P) from a rat histiocytic sarcoma.

Lipopolysaccharide (LPS) is a major modulator of macrophage functions. To characterize a newly established rat histiocytic sarcoma-derived cell line (HS-P), immunophenotypic changes and cellular growth responses of HS-P cells exposed to LPS were investigated and compared with those of MT-9 cells isolated from a rat malignant fibrous histiocytoma. MT-9 cells have somewhat histiocytic features, because occasional cells react to rat macrophage-specific antibodies. Addition of LPS to cultured HS-P cells increased the numbers of cells immunopositive to ED1 (rat macrophage-specific antibody) and ED2 (rat histiocyte-specific antibody) and stimulated the phagocytosis of latex beads, whereas LPS-treated MT-9 cells did not show such immunophenotypic changes. LPS-treated HS-P cells showed enhanced immunolabelling of alpha-smooth muscle actin, suggesting a possible modulation of macrophages towards myofibroblastic cells. To evaluate cellular growth after the addition of LPS or fetal bovine serum, DNA synthesis was examined by measuring tritiated thymidine incorporation, and the mRNA expression of c- jun and c- myc (immediate early genes in the cell cycle) was examined by Northern blot analysis. In HS-P cells, the addition of serum greatly increased DNA synthesis and induced high expression of c- jun and c- myc; in contrast, LPS markedly depressed DNA synthesis and reduced the expression of c- jun and c- myc. HS-P cells were more sensitive than MT-9 cells to the growth-promoting effect of serum and the growth-inhibiting effect of LPS. The study demonstrated that HS-P cells are highly LPS-responsive, indicating that they would be useful for studies of macrophage functions.

Animals↗

PubMed2001

Variation of des-gamma-carboxyprothrombin (PIVKA-II) levels in cord blood throughout gestation.

The variation of des-gamma-carboxyprothrombin (PIVKA-II, protein induced by vitamin K absence) levels in umbilical cord blood throughout gestation was examined using a highly sensitive method, electrochemiluminescence immunoassay (ECLIA). PIVKA-II levels in infants without any complications were low, but modestly high, exceeding the normal range of healthy adults during the preterm period, followed by a remarkable increase after the 37th week of gestation. Among infants complicated with severe preeclampsia a marked increase of PIVKA-II levels was observed in preterm infants, showing a good correlation with the existence ofinfarctions on the placenta. On the other hand, among infants complicated with preterm premature rupture of the membranes (PROM) in which antibiotics were administered during the prenatal period, a moderate elevation of PIVKA-II levels was observed. These data suggest that the normal range of PIVKA-II in fetuses is modestly high compared with adults and any deficient status of vitamin K would not exist throughout the preterm period. Nevertheless, the vitamin K status might readily fall into a deficient condition in term infants. Furthermore, it is notable that vitamin K deficiency would be induced in complicated gestation with severe preeclampsia and medication with antibiotics.

Biomarkers↗

PubMed2001

Isolation of Bacillus thuringiensis from intertidal brackish sediments in mangroves.

Intertidal brackish sediments in mangroves were examined for isolation of Bacillus thuringiensis strains with novel toxicity spectra. A total of 18 B. thuringiensis isolates were recovered from eight sediment samples (36.4%) out of 22 samples tested. The frequency of B. thuringiensis was 1.3% among the colonies of Bacillus cereus/B. thuringiensis group. While five isolates were allocated to the four H serogroups, the majority of the isolates were serologically untypable or untestable. Two isolates belonging to the serovar israelensis/tochigiensis (H14/19) exhibited strong toxicities against larvae of the mosquito, Culex pipiens molestus, and mammalian cells (sheep erythrocyte and two human cancer cell lines) in vitro. The other 16 isolates showed no toxicity against the mosquito and mammalian cells. None of the isolates showed larvicidal activity against the diamondback moth, Plutella xylostella. Strong lectin activities against sheep erythrocytes were associated with two serologically untestable isolates and an H3 isolate.

Animals↗

PubMed2001

Inhibition of azoxymethane-induced colon carcinogenesis in male F344 rats by the citrus limonoids obacunone and limonin.

The modifying effects of dietary administration of the citrus limonoids obacunone and limonin on azoxymethane (AOM)-induced colon tumorigenesis were investigated in two experiments in male F344 rats. In a pilot study, we examined the modifying effects of obacunone and limonin on AOM-induced (20 mg/kg body wt, once a week for 2 weeks) formation of aberrant crypt foci (ACF). Dietary feeding of both compounds at dose levels of 200 and 500 p.p.m. during AOM exposure for 4 weeks ('initiation' feeding) or after AOM treatment for 4 weeks ('post-initiation' feeding) significantly inhibited ACF formation (55-65% reduction by 'initiation' feeding, P < 0.001; 28-42% reduction by 'post-initiation' feeding, P < 0.05-0.002). In a long-term study designed to confirm the protective effects of obacunone and limonin on ACF development, one group was treated with AOM alone and another four groups received the carcinogen treatment plus diets containing 500 p.p.m. test compounds for 3 weeks (initiation phase) or 29 weeks (post-initiation phase). Two groups were treated with obacunone or limonin alone (500 p.p.m. in diet) and one group was maintained on the basal diet. At the termination of the study, dietary exposure to obacunone or limonin during the initiation phase was found to have significantly reduced the incidence of colonic adenocarcinoma (72 versus 25 or 6%, P = 0.004 or 0.00003). Obacunone or limonin feeding during the post-initiation phase also reduced the frequency of colonic adenocarcinoma (72 versus 13%, P = 0.0002). Our results suggest that the citrus limonoids obacunone and limonin might be useful for the prevention of human colon cancers.

Animals↗

PubMed2001

Suppression of N-nitrosomethylbenzylamine (NMBA)-induced esophageal tumorigenesis in F344 rats by JTE-522, a selective COX-2 inhibitor.

Recent studies have demonstrated that overexpression of cyclooxygenase-2 (COX-2) and elevation of COX-2-mediated synthesis of prostaglandin E(2) (PGE(2)) were observed in various cancers including esophageal cancer, but their roles in carcinogenesis of the esophagi still remain unclear. To address the issue, we observed the reduction of N:-nitrosomethylbenzylamine (NMBA)-induced tumorigenesis in rat esophagi via JTE-522 (4-[4-cyclohexyl-2-methyloxazol-5-yl]-2-fluorobenzenesulfonamide), a selective COX-2 inhibitor. In this study, 54 F344 male rats were divided into nine groups; JTE-522 (3, 9 and 30 mg/kg) was administered orally. We also examined the effects of JTE-522 on COX-2 mRNA and synthesis of PGE(2). In the group in which JTE-522 was administered intermittently at a daily dose of 30 mg/kg, the number of NMBA-induced esophageal tumors per rat significantly reduced, to 62% (P< 0.05), but the size of the tumors was not significantly inhibited. In the group in which JTE-522 was administered continuously five times weekly for 24 weeks at a daily dose of 9 mg/kg, both the number and size of tumors significantly reduced, to 29 and 44%, respectively (P<0.05). Furthermore, JTE-522 suppressed not only tumor formation but also developing carcinomas (P<0.0021) [corrected]. In this study, treatment with NMBA alone resulted in an approximately 5-fold rise in expression of COX-2 mRNA detected by semi-quantitative RT-PCR analysis and an approximately 7-fold increase in the production of PGE(2) measured by ELISA compared with the normal esophageal mucosa. The up-regulated COX-2 expression did not decrease with the treatment of JTE-522 at the 3, 9 and 30 mg/kg doses; however, the increased levels of PGE(2) synthesis were significantly decreased by administering JTE-522 (P<0.01). Our study suggests that COX-2-mediated PGE(2) is important in NMBA-induced esophageal tumorigenesis in rats, and therefore may be a promising chemotherapeutic target for the prevention and treatment of esophageal cancer, especially with selective COX-2 inhibitors.

Animals↗

PubMed2001

Immunocytochemistry of glutathione S-transferase in taste bud cells of rat circumvallate and foliate papillae.

Immunocytochemistry was used to investigate the distribution of cells reacting with specific antibodies against glutathione S-transferase (GST) mu and pi in rat circumvallate and foliate taste buds; the findings were confirmed by Western blotting. Double immunofluorescence staining for protein gene product (PGP) 9.5 and GST subunits allowed the classification of taste bud cells of both papillae into: (i) cells immunoreactive to either PGP 9.5 or GST subunit antibody; (ii) cells immunoreactive to both antibodies; and (iii) cells that did not react with either of these antibodies. Immunoelectron microscopy revealed that most GST subunit-immunoreactive cells seemed to be either type II or type III cells based on their ultrastructure. Since PGP 9.5 is now widely used as a marker for type III cells in mammalian taste buds, it seems reasonable to believe that most GST subunit-immunoreactive cells are type II cells. Whether cells immunoreactive for both PGP 9.5 and GST subunits constitute a small subpopulation of type III cells or whether they are intermediate forms between type II and III cells is under investigation. No type I cells reacted with antibodies against GST subunits in the present study. GST subunits in taste bud cells may participate in xenobiotic metabolism of certain substances exposed to taste pits, as already shown for olfactory epithelium.

Animals↗

PubMed2001

A novel regulation system of gene expression responding to protease signal.

A cationic polymer, in which a cleavage site with Caspase 3 (CPCC) was introduced, was synthesized. Then an interaction between the polymer and a DNA was investigated with gel electrophoresis in the presence or absence of Caspase 3. When the CPCC polymer was added to the DNA solution, the migration of the DNA was suppressed with the increase of the addition of the polymer in the gel electrophoresis. However, this delay was cancelled with the addition of Caspase 3. These results suggested that this synthesized polymer interacted with the DNA, and the side chain cleavage of this polymer by Caspase 3 reduced the interaction between the polymer and the DNA. Such system would be useful for the design of an artificial gene regulation system responding to cellular apoptotic signal.

Amino Acid Sequence↗

PubMed2001

Single nucleotide polymorphisms (SNPs) assay using reversible association and dispersion of DNA-linked colloidal nanoparticles.

The amphiphilic copolymer consisting of oligodeoxyribonucleotide (ODN; dT12) as the hydrophilic part and thermo-responsive poly(N-isopropylacrylamide) (polyNIPAAm) as the hydrophobic part was prepared. The copolymers formed DNA-linked colloidal nanoparticles above the phase transition temperature of polyNIPAAm part. The nanoparticles aggregated rapidly when the complementary ODN (dA12) was added into the dispersion. In contrast, they kept dispersed in the absence of the complementary ODN and in the presence of the point-mutated ODN ((dA6)dT(dA5)). These distinct phenomena may be applied for an oligonucleotides discrimination system in gene diagnosis.

Acrylic Resins↗

PubMed2001

New base analogs for the formation of non-natural triplexes.

Novel nucleoside analogs have been designed for selective formation of antiparallel triplexes including a TA or a CG interrupting site. The new compounds are constructed of a W-shape bicyclic nucleic acid (WNA) bearing an aromatic ring as a stacking motif and a guanine for the formation of Hoogesteen hydrogen bonds, and are expected to effect triplex stabilization by both stacking and complementary hydrogen bonds. Purine-rich triplex-forming oligodeoxynucleotide (TFO) incorporating the new analog, WNA-7 beta G, formed a stable triplex with high selectivity to the AT site.

DNA↗

PubMed2001

Efficient cross-linking to cytidine under neutral conditions using the 2-amino-6-vinylpurine derivative having an additional activating group.

We have previously reported that the oligonucleotides incorporating 2-amino-6-vinyl purine analog (1) showed efficient interstrand cross-linking with selectivity toward cytidine at a target site. In this paper, we describe the design of more efficient cross-linking reagent (2) bearing 2-amino-6-vinyl purine motif to react to cytidine selectively under neutral condition.

Base Sequence↗

PubMed2001

Identification and characterization of two penta-EF-hand Ca(2+)-binding proteins in Dictyostelium discoideum.

Penta-EF-hand (PEF) proteins such as ALG-2 (apoptosis-linked gene 2 product) and the calpain small subunit are a newly classified family of Ca(2+)-binding proteins that possess five EF-hand-like motifs. We identified two mutually homologous PEF proteins, designated DdPEF-1 and DdPEF-2 (64% amino acid residue identities), in the cellular slime mold Dictyostelium discoideum. Both PEF proteins showed a higher similarity to mammalian ALG-2 and peflin (Group I PEF proteins) than to calpain and sorcin subfamily (Group II PEF proteins) in the first EF-hand (EF-1) regions. Northern blot analyses revealed that DdPEF-1 and DdPEF-2 were constitutively expressed throughout development of Dictyostelium, but their levels of expression were developmentally regulated. In situ hybridization analyses demonstrated that DdPEF-1 was expressed in both the anterior prestalk and the posterior prespore regions of the tipped aggregate, slugs and early culminants. On the other hand, DdPEF-2 was dominantly expressed in the anterior tip region of these multicellular structures. Both PEF proteins were detected as 22-23-kDa proteins in soluble fractions in the presence of EGTA but in particulate fractions in the presence of Ca(2+) by Western blotting using specific monoclonal antibodies. Together with the finding of PEF-like sequences in DNA databases of plants, fungi and protists, our results strongly suggest that Group I PEF proteins are ubiquitously present in all eukaryotes and play important roles in basic cellular functions.

Amino Acid Sequence↗

PubMed2001

Primary diffuse tracheobronchial amyloidosis: radiologic findings.

Reports detailing the radiologic features of tracheobronchial amyloidosis are scant and typically describe only the computed tomography findings of this disease. No reports have described the magnetic resonance (MR) findings of tracheobronchial amyloidosis. With this case, the authors describe the radiologic findings in a patient with diffuse tracheobronchial amyloidosis, focusing particularly on the MR and bone scintigraphy findings in this disease.

Amyloidosis↗

PubMed2001

Pseudomonas putida CE2010 can degrade biphenyl by a mosaic pathway encoded by the tod operon and cmtE, which are identical to those of P. putida F1 except for a single base difference in the operator-promoter region of the cmt operon.

Psudomonas putida CE2010 can assimilate biphenyl despite its high similarity to P. putida F1. Biphenyl degradation in strain CE2010 was achieved using a mosaic of pathways consisting of the cmt and tod operons. CmtE hydrolysed 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoic acid, the meta-cleavage product of 2,3-dihydroxybiphenyl. This enzyme was expressed differently in strains CE2010 and F1. A cmtE disruption mutant, a tod operon disruption mutant and a cmt operon disruption mutant were unable to utilize biphenyl. The introduction of the cmtE gene enabled the cmt operon disruption mutant to grow on biphenyl. A single base difference was found in the cmt promoter-operator region in strain CE2010, compared with that of strain F1. CymR protein was purified from Escherichia coli and binding assays were performed, the results of which suggested that the protein bound less strongly to the CE2010 operator sequence than to the F1 operator sequence. Exchanging the F1 promoter-operator fragment into strain CE2010 resulted in a loss of biphenyl degradation capacity. These results indicate that cmtE is not effectively repressed by CymR in strain CE2010, leading to low constitutive expression and, therefore, low growth on biphenyl.

Bacterial Proteins↗

PubMed2001

Surfactant protein D (SP-D) and systemic scleroderma (SSc).

We measured serum levels of SP-D in collagen diseases (110 cases) such as systemic scleroderma (SSc), scleroderma spectrum disorders (SSD), systemic lupus erythematodes (SLE), Sjogren syndrome (Sjs), dermatomyositis (DM), rheumatoid arthritis (RA), and dermatitis (DE) (109 cases) as a control. Additionally, we performad a correlation analysis to determine how these levels were related to pulmonary fibrosis and function test (vital capacity, %DLco). The serum levels of SP-D increased in SSc patients with Barnett type III more than in SSc patients with Barnett type I or II, while they increased slightly in SSD (incomplete type of SSc) patients. The differences in these figures were statistically significant between the SSc (SSc & SSD) and non-SSc (SLE, DM, Sjs & RA) groups (p<0.005). The serum levels of SP-D in SSc patients with anti-topoisomerase I antibodies were statistically higher than those in SSc patients with other types of anti-nuclear antibodies. There was a statistically significant correlation between the severity of pulmonary fibrosis and the serum levels of SP-D, and a statistically negative correlation between SP-D levels and vital capacity or %DLco, but there was no proportional correlation with the forced expiatory volume (FEV1.0%). There was no statistical relationship between pre- and post-therapy with photopheresis; however, there was a statistical correlation between the serum levels of SPD and KL-6. In the group of collagen diseases, plasma levels of SP-D were higher than serum levels of SP-D. Patients with SSc possess higher levels of SP-D than do those with other collagen diseases and dermatitis, which may correspond to the severity of pulmonary fibrosis.

Adolescent↗

PubMed2001

Anticarcinogenic effect and enhancement of metastatic potential of BALB/c 3T3 cells by ginsenoside Rh(2).

It has been reported that ginsenoside Rh(2), a purified ginseng saponin with a dammarane skeleton, has anticarcinogenic effects on mammalian cells. To determine the significance of these effects on multistage carcinogenesis, we utilized the BALB / c 3T3 cell system. In an in vitro two-stage neoplastic transformation assay, the initiating activity of 3-methylcholanthrene (3-MCA) was suppressed by Rh(2) (>or= 1 x 10(-5) M) in both BALB / c 3T3 A31-1-1 cells and the more carcinogen-susceptible variant A31-1-13 cells. The suppressive effects in this concentration range were thought to be caused by suppression of DNA replication via indirect Cdk2 inhibition. On the other hand, the promotion steps of both the target cells were not affected by Rh(2) even if the transformation frequency was enhanced by a tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA). To examine the other effects of Rh(2) on carcinogenesis, we turned our attention to the metastatic phenotype. Using metastatic src-transformed A31-1-1 cells, we found that Rh(2) augmented the metastatic potential in an experimental metastasis assay. These data indicate that Rh(2) has diverse effects on the expression of the transformed phenotype in BALB / c 3T3 cells, but support the idea that growth suppression is likely to be a major mechanism of the anticarcinogenic effects of Rh(2).

3T3 Cells↗

PubMed2001

Aortic dissection: percutaneous management with a separating stent-graft--preliminary results.

The authors used a separating stent-graft to treat Stanford type B aortic dissection. The separating stent-graft consists of two stents: a stent-graft and an inner bare stent. The separating stent-graft has three parts: a proximal stent, a graft made of synthetic polyester textile fiber, and a distal stent. A 12-F introducing sheath was used. After the separating stent-graft was placed, false-lumen thrombosis was evident in all six patients during a follow-up period of 206 days. The major advantages of this technique are that a cutdown and blood pressure control are not required.

Adult↗

PubMed2001

Role of osteopontin in the pathogenesis of bleomycin-induced pulmonary fibrosis.

Pulmonary fibrosis is initiated by migration, adhesion, and proliferation of fibroblasts. Osteopontin (OPN) is one of the cytokines produced by activated macrophages and mediates various functions, including cell attachment and migration, by interacting with alphav integrin. In this study, we have investigated the role of OPN in the pathogenesis of pulmonary fibrosis. We developed a mouse model for pulmonary fibrosis by intratracheal instillation of bleomycin (BLM). OPN was strongly expressed in alveolar macrophages accumulating in the fibrotic area of the lung. OPN messenger RNA (mRNA) in the lung was notably induced by BLM instillation, and the development of the fibrotic process was associated with an increase in the expression of OPN mRNA and protein. In vitro, recombinant OPN enhanced migration, adhesion, and platelet-derived growth factor (PDGF)-mediated DNA synthesis of murine fibroblast cell line NIH3T3. These effects of OPN on fibroblasts were significantly suppressed by addition of antimouse alphav integrin monoclonal antibody (RMV-7). Furthermore, treatment of mice with RMV-7 repressed the extent of pulmonary fibrosis in this model. Conclusively, these data suggest that OPN produced by alveolar macrophages functions as a fibrogenic cytokine that promotes migration, adhesion, and proliferation of fibroblasts in the development of BLM-induced pulmonary fibrosis.

Animals↗

PubMed2001

Characterization of the mouse TFF1 (pS2) gene promoter region.

Trefoil peptides (TFFs) with a unique trefoil domain(s) are presumed to function in protection and repair of the gastrointestinal epithelial layer. Three peptide family members are differently distributed in the mouse gastrointestinal tract: TFF1/pS2 specifically in stomach, TFF2/SP mainly in stomach, pancreas and duodenum, and TFF3/ITF in intestine. We cloned and sequenced the mouse TFF1 gene 5'-upstream region by means of the genomic walking procedure. The cloned region was ligated to the luciferase reporter gene and then introduced into mouse gastric surface mucous GSM10 cells which express TFF1 and TFF2. The minimum promoter was located in the region containing the TATA-box between -39 and the transcriptional start site. Further upstream regions stimulated (-2192-- -1630bp, -641-- -243bp, -137-- -39bp) and inhibited (-1630-- -641bp, -243-- -137 bp) luciferase gene expression. These regions as well as short segments conserved in the mouse and human 5'-upstream sequences may be important for modulation of the mRNA level of the TFF1 gene.

Animals↗