Biomedical subjects

T Tamura

Publications and source records attributed to T Tamura.

At least 19 recordsLinked to original sources

PubMed2007

Germ line transformation of the silkworm, Bombyx mori, using the transposable element Minos.

We investigated the use of Minos as a vector for transgenesis in the silkworm, Bombyx mori. We first constructed a vector plasmid with the green fluorescent protein (GFP) gene fused with the silkworm cytoplasmic actin gene (A3) promoter, and a helper plasmid with the Minos transposase gene controlled by the same A3 promoter. Injection of the vector and helper plasmid DNA into silkworm eggs produced transgenic animals in the following generation. The efficiency of transgenic silkworm production using this method was much lower than that obtained using piggyBac-mediated germ line transformation. However, >40-fold increase in the efficiency of producing transgenic silkworms was obtained using an in vitro synthesized source of Minos transposase mRNA. We conclude that the Minos transposon is a useful vector for construction of transgenic silkworms, particularly when in vitro synthesized mRNA is used. This is the first report showing that Minos can be used as a vector for germ-line transformation in lepidopteran insects.

Actins↗

PubMed2006

No significant difference in neutrophil activation found among three H2RAs.

BACKGROUND: Even with the most effective treatment, Helicobacter pylori eradication is difficult in some patients. Therefore, patients sometimes require acid-suppressive therapy without H. pylori eradication. It has been reported that ranitidine inhibits neutrophil activation, whereas famotidine does not. However, few studies have been published concerning the activation of neutrophils before and after treatment using clinical doses of histamine-2 receptor antagonists in patients with H. pylori infection. AIM: To examine the effects of neutrophil activation after treatment with three different histamine-2 receptor antagonists. PATIENTS: This prospective, open-label, randomised, parallel-group study was conducted. Thirty patients with H. pylori infection were enrolled. These subjects were randomly assigned to receive one of the following treatments: (a) 150 mg ranitidine, (b) 20mg famotidine, or (c) 10 mg lafutidine b.d., for 4 weeks. Before and after histamine-2 receptor antagonist treatment, histological findings, myeloperoxidase activity, and interleukin-8 in the gastric mucosa were evaluated. RESULTS: On the basis of the histological findings between before and after histamine-2 receptor antagonist treatment, no significant differences were found in any groups. Similarly, there were no significant differences in myeloperoxidase activity or interleukin-8 levels. CONCLUSION: In patients with H. pylori, when used at clinical doses, any histamine-2 receptor antagonists can be used without concerning about inhibition of neutrophil activation.

Acetamides↗

PubMed2006

Randomized phase III study of cisplatin plus irinotecan versus carboplatin plus paclitaxel, cisplatin plus gemcitabine, and cisplatin plus vinorelbine for advanced non-small-cell lung cancer: Four-Arm Cooperative Study in Japan.

BACKGROUND: To compare the efficacy and toxicity of three platinum-based combination regimens against cisplatin plus irinotecan (IP) in patients with untreated advanced non-small-cell lung cancer (NSCLC) by a non-inferiority design. PATIENTS AND METHODS: A total of 602 patients were randomly assigned to one of four regimens: cisplatin 80 mg/m(2) on day 1 plus irinotecan 60 mg/m(2) on days 1, 8, 15 every 4 weeks (IP) carboplatin AUC 6.0 min x mg/mL (area under the concentration-time curve) on day 1 plus paclitaxel 200 mg/m(2) on day 1 every 3 weeks (TC); cisplatin 80 mg/m(2) on day 1 plus gemcitabine 1000 mg/m(2) on days 1, 8 every 3 weeks (GP); and cisplatin 80 mg/m(2) on day 1 plus vinorelbine 25 mg/m(2) on days 1, 8 every 3 weeks (NP). RESULTS: The response rate, median survival time, and 1-year survival rate were 31.0%, 13.9 months, 59.2%, respectively, in IP; 32.4%, 12.3 months, 51.0% in TC; 30.1%, 14.0 months, 59.6% in GP; and 33.1%, 11.4 months, 48.3% in NP. No statistically significant differences were found in response rate or overall survival, but the non-inferiority of none of the experimental regimens could be confirmed. All the four regimens were well tolerated. CONCLUSION: The four regimens have similar efficacy and different toxicity profiles, and they can be used to treat advanced NSCLC patients.

Adenocarcinoma↗

PubMed2006

EGFR mutation status in tumour-derived DNA from pleural effusion fluid is a practical basis for predicting the response to gefitinib.

Epidermal growth factor receptor (EGFR) mutations are strong determinants of tumour response to EGFR tyrosine kinase inhibitors in non-small-cell lung cancer (NSCLC). Pleural effusion is a common complication of lung cancer. In this study, we assessed the feasibility of detection of EGFR mutations in samples of pleural effusion fluid. We obtained 43 samples, which was the cell-free supernatant of pleural fluid, from Japanese NSCLC patients, and examined them for EGFR mutations. The epidermal growth factor receptor mutation status was determined by a direct sequencing method (exons 18-21 in EGFR). EGFR mutations were detected in 11 cases (E746_A750del in seven cases, E746_T751del insA in one case, L747_T751del in one case, and L858R in two cases). The EGFR mutations were observed more frequently in women and non-smokers. A comparison between the EGFR mutant status and the response to gefitinib in the 27 patients who received gefitinib revealed that all seven patients with partial response and one of the seven patients with stable disease had an EGFR mutation. No EGFR mutations were detected in the patients with progressive disease. The results suggest that DNA in pleural effusion fluid can be used to detect EGFR mutations and that the EGFR mutation status may be useful as a predictor of the response to gefitinib.

Adenocarcinoma↗

PubMed2006

Promotion of axonal maturation and prevention of memory loss in mice by extracts of Astragalus mongholicus.

BACKGROUND AND PURPOSE: Neurons with atrophic neurites may remain alive and therefore may have the potential to regenerate even when neuronal death has occurred in some parts of the brain. This study aimed to explore effects of drugs that can facilitate the regeneration of neurites and the reconstruction of synapses even in severely damaged neurons. EXPERIMENTAL APPROACH: We investigated the effects of extracts of Astragalus mongholicus on the cognitive defect in mice caused by injection with the amyloid peptide Abeta(25-35). We also examined the effect of the extract on the regeneration of neurites and the reconstruction of synapses in cultured neurons damaged by Abeta(25-35). KEY RESULTS: A. mongholicus extract (1 g kg(-1) day(-1) for 15 days, p.o.) reversed Abeta(25-35)-induced memory loss and prevented the loss of axons and synapses in the cerebral cortex and hippocampus in mice. Treatment with Abeta(25-35) (10 microM) induced axonal atrophy and synaptic loss in cultured rat cortical neurons. Subsequent treatment with A. mongholicus extract (100 microg/ml) resulted in significant axonal regeneration, reconstruction of neuronal synapses, and prevention of Abeta(25-35)-induced neuronal death. Similar extracts of A. membranaceus had no effect on axonal atrophy, synaptic loss, or neuronal death. The major known components of the extracts (astragalosides I, II, and IV) reduced neurodegeneration, but the activity of the extracts did not correlate with their content of these three astragalosides. CONCLUSION AND IMPLICATIONS: A. mongholicus is an important candidate for the treatment of memory disorders and the main active constituents may not be the known astragalosides.

Amyloid beta-Peptides↗

PubMed2006

FMIP controls the adipocyte lineage commitment of C2C12 cells by downmodulation of C/EBP alpha.

Fms interacting protein (FMIP) is a substrate for Fms tyrosine kinase, and a nuclear/cytoplasm shuttling protein with a leucine zipper. As the phosphorylation of FMIP is observed in insulin-stimulated preadipocytes, we examined the role of FMIP in adipocyte differentiation, using the mesenchymal multipotent stem cells, C2C12 cells, that can differentiate into adipocytes, muscle cells and osteoblasts. Ectopic expression of FMIP in C2C12 impairs the adipocyte differentiation induced by treatment with insulin, dexamethasone and 3-isobutyl-1-methylxanthine. These cells exhibit muscle phenotype with multinuclear morphology. Furthermore, knockdown of endogenous FMIP expression by small interfering RNA improves adipocytic lineage commitment of C2C12 cells, while impairing muscle differentiation. Upon stimulation with insulin, CCAAT/enhancer binding protein (C/EBP)beta, but not C/EBPalpha, is upregulated in cells expressing ectopic FMIP, whereas in FMIP knockdown cells, C/EBPalpha is constitutively expressed. Ectopic expression of C/EBPalpha counteracts the effects of FMIP, whereas C/EBPalpha knockdown partially mimics the effects of FMIP in this system. Northern blot analysis and reverse transcriptase-polymerase chain reaction study reveal that ectopic FMIP-expressing cells do not contain the polyadenylated C/EBPalpha mRNA, but contain the C/EBPalpha pre-mRNA, suggesting that FMIP plays a role in RNA processing and/or export. Indeed, a member of the THO complex that plays a role in mRNA export, THOC1, is co-precipitated with FMIP. The data we have acquired on FMIP suggest that it is a target for tyrosine kinase receptors that potentiate mRNA export.

Adipocytes↗

PubMed2006

Inhibition of the mammalian target of rapamycin (mTOR) by rapamycin increases chemosensitivity of CaSki cells to paclitaxel.

Paclitaxel, a potent anti-neoplastic agent, has been found to be effective against several tumours, including cervical cancer. However, the exact mechanism underlying the cytotoxic effects of pacitaxel, especially in the survival-signalling pathway, is poorly understood. The aim of this study was to investigate the molecular pathway of the cytotoxic effect of paclitaxel in human cervical cancer cell lines. Four human cervical cancer cell lines were treated for 24 h with various concentration of paclitaxel, and the sensitivity was analysed by an MTT assay. The cell cycle progression and sub-G1 population were analysed by flow cytometry. Apoptosis was further measured by DNA fragmentation and microscope examination. The protein expression was determined by Western blot analysis. Our results showed that HeLa cells demonstrated the highest sensitivity to paclitaxel, whereas CaSki cells showed the lowest. In cervical cancer cells, paclitaxel induced apoptosis through an intrinsic pathway with prior G2/M arrest. In addition, we showed that paclitaxel downregulated the phosphorylation of Akt in both HeLa and CaSki cells. Interestingly, in CaSki cells, which were more suggestive of a resistant phenotype, paclitaxel induced the activation of mTOR as a downstream target of Akt. Pre-treatment with rapamycin inhibited activation of mTOR signalling and significantly enhanced the sensitivity of CaSki cells to paclitaxel by increasing apoptotic cell death. This effect was mediated, at least partly, through caspase activation. Overall, paclitaxel exerts its anti-tumour effects on cervical cancer cells by inducing apoptosis through intrinsic pathway, and rapamycin targeted to mTOR can sensitise paclitaxel-resistant cervical cancer cells.

Antineoplastic Agents↗

PubMed2006

Invasive growth of hepatic angiomyolipoma; a hitherto unreported ominous histological feature.

AIMS: Although histological features of hepatic angiomyolipoma (AML) are highly variable, true malignant change is extremely rare. The aim was to review the histological features of invasive growth and clinical outcomes in 39 cases of hepatic AML. METHODS AND RESULTS: An invasive growth pattern into surrounding hepatic parenchyma, portal triads and/or around hepatic veins was found in 24 of 39 tumours (62%). One variant showed tumour cells replacing hepatocytes within the liver cell cords. The other consisted of portal or perivascular invasive growth along blood vessels. In the former pattern, small isolated tumour cell clusters were occasionally found in the vicinity of the main mass, showing a sprouting pattern. Although these histological features suggest malignancy, distant metastases were not found in any of the cases within a mean follow-up period of 6.8 years. CONCLUSIONS: A previously unrecognized histological feature of an invasive growth pattern, which suggests malignancy and might promote an erroneous diagnosis, was frequently found in hepatic AMLs. However, among about 180 reported hepatic AMLs, including the present cases, only one hepatic AML with distant metastasis has been reported to date and nearly all hepatic AMLs behave in a benign fashion. Therefore, pathologists should not overdiagnose malignancy based solely on the histological invasive growth patterns described in this paper.

Adult↗

PubMed2006

Genetic variations and haplotype structures of the ABCB1 gene in a Japanese population: an expanded haplotype block covering the distal promoter region, and associated ethnic differences.

As functional ABCB1 haplotypes were recently reported in the promoter region of the gene, we resequenced the ABCB1 distal promoter region, along with other regions (the enhancer and proximal promoter regions, and all 28 exons), in a total of 533 Japanese subjects. Linkage disequilibrium (LD) analysis based on 92 genetic variations revealed 4 LD blocks with the same make up as previously described (Blocks -1, 1, 2 and 3), except that Block 1 was expanded to include the distal promoter region, and that a new linkage between polymorphisms -1,789G>A in the distal promoter region and IVS5 + 123A>G in intron 5 was identified. We re-assigned Block 1 haplotypes, and added novel haplotypes to the other 3 blocks. The reported promoter haplotypes were further classified into several types according to tagging variations within Block 1 coding or intronic regions. Our current data reconfirm the haplotype profiles of the other three blocks, add more detailed information on functionally-important haplotypes in Block 1 and 2 in the Japanese population, and identified differences in haplotype profiles between ethnic groups. Our updated analysis of ABCB1 haplotype blocks will assist pharmacogenetic and disease-association studies carried out using Asian subjects.

ATP Binding Cassette Transporter, Subfamily B↗

PubMed2005

Levofloxacin- versus metronidazole-based rescue therapy for H. pylori infection in Japan.

BACKGROUND: The ideal second-line treatment regimens for Helicobacter pylori infection may differ between the areas, countries and races. AIM: The aim was to confirm which was the better regimen for second-line therapy after treatment failure with a standard triple therapy in Japan, a high dosage of levofloxacin- or metronidazole-based therapy. PATIENTS: Sixty outpatients with persistent H. pylori infection after a standard triple therapy were enrolled in this prospective, open-label and randomised trial. METHODS: The subjects were randomly administered levofloxacin (300 mg b.d.)- or metronidazole (500 mg b.d.)-based therapy with lansoprazole (30 mg b.d.) and amoxicillin (1000 mg b.d.) for 7 days, and the cure rates and side effects were analysed. Antimicrobial susceptibility was also examined before second-line therapy using the E-test. RESULTS: Good compliance was obtained without severe side effects in both the groups except for two patients. The cure rates, expressed as intention-to-treat and per-protocol analyses, respectively, were 70.0 and 72.4% in the levofloxacin group, and 96.7 and 100% in the metronidazole group. Each regimen often overcame even clarithromycin-resistant strains. CONCLUSION: Metronidazole-based triple therapy is recommended as second-line therapy in Japan, and levofloxacin-based therapy can be an alternative treatment option.

Adult↗

PubMed2005

Blood homocysteine, folate and vitamin B-12 concentrations in patients with epilepsy receiving lamotrigine or sodium valproate for initial monotherapy.

To evaluate whether the administration of lamotrigine (LTG) or valproate (VPA) changes concentrations of plasma total homocysteine (tHcy), plasma and red-cell folate and plasma Vitamin B-12, we measured these indices in a total of 20 patients with epilepsy before and after a 32-week period of monotherapy of LTG or VPA. We found that the 32-week administration of a mean daily dose of 250mg LTG had no significant effect on any of the blood indices. On the other hand, the administration of a mean daily dose of 2070mg of VPA resulted in a 57% increase in plasma Vitamin B-12 concentrations over the baseline value and a 27% decline in plasma tHcy concentrations, although the mechanisms of such changes are unknown. Our data indicate that hyperhomocysteinemia may not be a serious clinical problem among patients with epilepsy, who receive either LTG or VPA.

Adult↗

PubMed2005

Olopatadine hydrochloride suppresses the rebound phenomenon after discontinuation of treatment with a topical steroid in mice with chronic contact hypersensitivity.

BACKGROUND: Olopatadine hydrochloride (olopatadine; Allelock) is one of the second-generation antihistamines that are treated for allergic disorders such as rhinitis, urticaria and eczema dermatitis. Olopatadine has recently been shown to have inhibitory effects on the chronic contact hypersensitivity induced by repeated application of oxazolone in mice. Although topical steroids have widely been prescribed for atopic dermatitis, a relapse often occurs within several days after discontinuation of their prolonged use. OBJECTIVES: We investigated the possible efficacy of olopatadine against the relapse after discontinuation of prolonged use of topical prednisolone in the Balb/c mice with oxazolone-induced chronic contact hypersensitivity. METHODS: Mice with the chronic contact hypersensitivity induced by repeated application of oxazolone were treated with olopatadine as a sequential therapeutic agent. The effects of olopatadine were quantified by measurements of ear-swelling, and levels of cytokines and histamine in the lesioned ear. Results Topical prednisolone (0.05 mg/ear/day) significantly inhibited the increases in ear swelling and production of IL-1beta, IL-4, IL-18, granulocyte-macrophage colony-stimulating factor (GM-CSF) and histamine. However, after discontinuation of the treatment with topical prednisolone, the inflammation relapsed and the IL-4 level exceeded the control one. The sequential treatment with olopatadine (10 mg/kg/day) after discontinuation of the treatment with topical prednisolone alone, or topical prednisolone with olopatadine, significantly inhibited the increases in ear swelling and levels of IL-1beta, IL-4, IL-18, GM-CSF, nerve growth factor and histamine. CONCLUSIONS: These results indicate that olopatadine is an antihistamine agent having inhibitory activities against the rebound phenomenon following the discontinuation of topical steroid therapy. Olopatadine is thus expected to be a sequential therapeutic agent after discontinuation of the chronic treatment with a topical steroid.

Animals↗

PubMed2005

Eradication of Helicobacter pylori increases platelet count in patients with idiopathic thrombocytopenic purpura in Japan.

BACKGROUND: The effect of Helicobacter pylori eradication on the platelet count in patients with thrombocytopenic purpura is controversial. In this multicentre study, we prospectively assessed the effect of H. pylori eradication therapy in idiopathic thrombocytopenic purpura patients. MATERIALS AND METHODS: Thirty-five consecutive patients with chronic idiopathic thrombocytopenic purpura (11 males and 24 females, a median age of 57) were assessed for H. pylori infection by use of a urea breath test. All patients received 1-week triple therapy (amoxicillin, clarithromycin, and lansoprazole) to eradicate H. pylori. At 6 months, idiopathic thrombocytopenic purpura patients with a platelet count recovery of greater than 100 x 10(9) L(-1) were defined as idiopathic thrombocytopenic purpura responders. RESULTS: Helicobacter pylori infection was observed in 25 (71%) of the 35 patients. All infected patients were cured. Eleven patients were identified as idiopathic thrombocytopenic purpura responders; 24 were considered nonresponders. Platelet counts improved by more than 100 x 10(9) L(-1) in 11 (44%) of the 25 patients cured of H. pylori infection, while none of the 10 patients H. pylori-negative patients experienced the same improvement (P = 0.015). Univariate analysis showed that H. pylori infection and its eradication were significant factors associated with platelet recovery (P = 0.015). CONCLUSIONS: Helicobacter pylori infection played a role in the pathogenesis of idiopathic thrombocytopenic purpura in approximately 30% of all patients assessed and 45% of the patients with H. pylori infection. Eradication of H. pylori in idiopathic thrombocytopenic purpura patients led to improved disease activity.

Adult↗

PubMed2005

Clinicostatistical study of carotid calcification on panoramic radiographs.

OBJECTIVE: The purpose was to evaluate carotid calcifications on panoramic radiographs, and relate to risk factors for vascular diseases. METHOD: Between 1997 and 2001, 2568 radiographs were retrospectively collected from new patients at Mie University Hospital whose ages ranged from 50 to 70 years. The mean age of the subjects was 62.2 years (men 61.9 years, women 62.3 years). Medical and social data were collected from case notes, and body weight, height, and age of menopause confirmed by telephone interviews. RESULT: About 106 carotid calcifications were found on the panoramic radiographs of 26 males and 80 females. The ratio of males to females was 1:3.07. The subjects with carotid calcifications had medical histories that included hypertension (27.6%), obesity (21.1%), hyperlipidemia (14.5%), and cardiovascular diseases (13.2%), all with recognized risk factors for atheromas. Of 76 patients who responded to follow up interviews, two (2.63%) died from cardiovascular stroke during an average follow up of 2.43 years. CONCLUSIONS: The results show carotid calcifications detected on panoramic radiographs can be used to help predict vascular strokes in patients. In cases where calcified carotid artery atheromas are detected, the dentist or oral and maxillofacial surgeon should refer the patient to a specialized physician.

Aged↗

PubMed2005

Lymph node pathway in the spread of endometrial carcinoma.

OBJECTIVE: To elucidate the sentinel nodes of endometrial carcinoma, the spread pathway was clarified. The correlation between lymph node spread and other clinicopathological variables was also analyzed. METHODS: Dissected lymph node samples in 342 patients who underwent pelvic and selective paraaortic lymphadenectomy were reviewed. Pelvic and paraaortic node (PLN and PAN) status was compared with clinicopathological parameters. RESULTS: Lymph node metastasis was demonstrated in 52 patients, including 46 cases with PLN metastasis and six patients with independent PAN metastasis. The metastatic sites were most frequent in the obturator and internal iliac nodes. Eleven of 49 patients who underwent PAN dissection were positive for metastasis. Sixteen of 23 cases with parametrial metastasis also metastasized in the retroperitoneal lymph node. CONCLUSION: The lymph node spread pathway in endometrial carcinoma consists of a major route via the obturator node or internal iliac node with or without parametrial involvement, and rarely a direct PAN pathway.

Adenocarcinoma↗

PubMed2004

Multi-institutional phase II trial of irinotecan, cisplatin, and etoposide for sensitive relapsed small-cell lung cancer.

Irinotecan (CPT-11) has been shown to exhibit excellent antitumour activity against small-cell lung cancer (SCLC). A multi-institutional phase II study was therefore conducted to evaluate the efficacy and toxicity of CPT-11 combined with cisplatin (CDDP) and etoposide (ETOP) (PEI regimen) for the treatment of sensitive relapsed SCLC. Patients who responded to first-line chemotherapy but relapsed more than 8 weeks after the completion of first-line therapy (n=40) were treated using the PEI regimen, which consisted of CDDP (25 mg m(-2)) weekly for 9 weeks, ETOP (60 mg m(-2)) for 3 days on weeks 1, 3, 5, 7, and 9, and CPT-11 (90 mg m(-2)) on weeks 2, 4, 6, and 8 with granulocyte colony-stimulating factor support. Five complete responses and 26 partial responses were observed, and the overall response rate was 78% (95% confidence interval 61.5-89.2%). The median survival time was 11.8 months, and the estimated 1-year survival rate was 49%. Grade 3/4 leucocytopenia, neutropenia, and thrombocytopenia were observed in 55, 73, and 33% of the patients, respectively. Nonhaematological toxicities were mild and transient in all patients. In conclusion, the PEI regimen is considered to be highly active and well tolerated for the treatment of sensitive relapsed SCLC.

Adult↗

PubMed2004

Fractal dynamics of body motion in post-stroke hemiplegic patients during walking.

In this paper, we quantify the complexity of body motion during walking in post-stroke hemiplegic patients. The body motion of patients and healthy elderly subjects was measured by using the accelerometry technique. The complexity of body motion was quantified using the maximum likelihood estimator (MLE-) based fractal analysis methods. Our results suggest that the fractal dimensions of the body motion in post-stroke hemiplegic patients at several Brunnstrom stages were significantly higher than those of healthy elderly subjects (p < 0.05). However, in the hemiplegic patients, the fractal dimensions were more related to Brunnstrom stages.

Acceleration↗

PubMed2004

Photoluminescence studies of oligothiophene self-assembled monolayers at low excitation energy.

Photoluminescence spectroscopy studies have been performed on self-assembled monolayers (SAMs) on Au(111) of thiophene oligomers with the number of thiophen rings N=3 and N=4. Photoluminescence spectra of SAMs reveal excitonic behavior with different band resolution and temperature dependence. These differences are attributed to different SAMs structure (degree of ordering).

Journal Article↗