Search PubMed⌕ Search

Biomedical subjects

H Ito

Publications and source records attributed to H Ito.

At least 73 records · Page 4Linked to original sources
PubMed2004

The effect of cellular proliferative activity on recurrence and local tumour extent of localized giant cell tumour of tendon sheath.

This study investigates whether the proliferative activity of giant cell tumour of tendon sheath is related to its recurrence rate and local aggressiveness. The clinicopathological and immunohistochemical features of 30 localized giant cell tumours of tendon sheath were studied and the influence of the MIB-1 staining index on recurrence, tumour extent around the phalanx and involvement of the bone were evaluated. No significant difference in the MIB-1 staining index was found between the lesions which recurred and those which did not. Also there was no significant association between local aggressiveness and the MIB-1 staining index. These results suggest that the proliferative activity of localized giant cell tumour of tendon sheath is not related to its high recurrence rate and local aggressiveness.

Adolescent↗
PubMed2004

Involvement of stress-activated protein kinase (SAPK)/c-Jun N-terminal kinase (JNK) in prostaglandin F2alpha-induced heat shock protein 27 in osteoblasts.

We have reported that prostaglandin F2(alpha) (PGF2(alpha)) activates p44/p42 mitogen-activated protein (MAP) kinase in osteoblast-like MC3T3-E1 cells, and that p44/p42 MAP kinase plays a role in the PGF2(alpha)-induced heat shock protein 27 (HSP27). In the present study, we investigated the involvement of stress-activated protein kinase (SAPK)/c-Jun N-terminal kinase (JNK), a member of the MAP kinase superfamily, in PGF2(alpha)-induced HSP27 in MC3T3-E1 cells. PGF2(alpha) time dependently induced the phosphorylation of SAPK/JNK. SP600125, a specific inhibitor of SAPK/JNK, markedly reduced the PGF2(alpha)-stimulated HSP27 accumulation. The inhibitory effect of SP600125 was dose dependent in the range between 0.1 and 30 microM. SP600125 reduced the PGF2(alpha)-increased level of HSP27 mRNA. SP600125 suppressed the phosphorylation of SAPK/JNK induced by PGF2(alpha), but did not affect the PGF2(alpha)-induced phosphorylation of p44/p42 MAP kinase. On the other hand, PD98059, a specific inhibitor of the upstream kinase of p44/p42 MAP kinase, which reduced the phosphorylation of p44/p42 MAP kinase stimulated by PGF2(alpha), had little effect on the PGF2(alpha)-induced phosphorylation of SAPK/JNK. These results strongly suggest that SAPK/JNK plays a part in PGF2(alpha)-induced HSP27 in addition to p44/p42 MAP kinase in osteoblasts.

Animals↗
PubMed2004

Focal adhesion kinase gene silencing promotes anoikis and suppresses metastasis of human pancreatic adenocarcinoma cells.

BACKGROUND: Inadequate or inappropriate cell-substrate contact triggers a subset of apoptotic cell death, termed anoikis. Resistance to anoikis is a characteristic of malignant cells that is associated with increased tumorigenesis and metastasis. Focal adhesion kinase (FAK) is an important regulator of cell survival and migration and cell cycle progression. We tested the hypothesis that FAK gene silencing would promote anoikis and reverse acquired anoikis resistance in human pancreatic adenocarcinoma cells. METHODS: FAK expression was assessed by Northern and Western blot analysis. Anoikis was induced in PANC1, BxPC3, MiaPaCa2, and Mia(AR) (an anoikis-resistant derivative of MiaPaCa2) with the use of polyHEMA culture. FAK expression was suppressed by RNA interference. Anoikis was detected by YO-PRO-1/propidium iodide staining and flow cytometry. Fluorometric caspase profiling was performed. Metastasis was assayed in a nude mouse orthotopic xenograft model. RESULTS: The cell lines that were tested showed marked variation in their anoikis resistance, greater resistance being associated with higher levels of FAK expression. FAK gene silencing promoted anoikis in all cell lines and reversed acquired anoikis resistance in Mia(AR), which was associated with increased caspase activation. Suppression of FAK expression also inhibited metastasis in the nude mouse model. CONCLUSION: FAK gene silencing suppresses anoikis resistance in pancreatic adenocarcinoma cells. FAK represents a potential target for novel antimetastatic therapies.

Adenocarcinoma↗
PubMed2004

PI3K-Akt pathway: its functions and alterations in human cancer.

Phosphatidylinositol-3-kinase (PI3K) is a lipid kinase and generates phosphatidylinositol-3,4,5-trisphosphate (PI(3, 4, 5)P3). PI(3, 4, 5)P3 is a second messenger essential for the translocation of Akt to the plasma membrane where it is phosphorylated and activated by phosphoinositide-dependent kinase (PDK) 1 and PDK2. Activation of Akt plays a pivotal role in fundamental cellular functions such as cell proliferation and survival by phosphorylating a variety of substrates. In recent years, it has been reported that alterations to the PI3K-Akt signaling pathway are frequent in human cancer. Constitutive activation of the PI3K-Akt pathway occurs due to amplification of the PIK3C gene encoding PI3K or the Akt gene, or as a result of mutations in components of the pathway, for example PTEN (phosphatase and tensin homologue deleted on chromosome 10), which inhibit the activation of Akt. Several small molecules designed to specifically target PI3K-Akt have been developed, and induced cell cycle arrest or apoptosis in human cancer cells in vitro and in vivo . Moreover, the combination of an inhibitor with various cytotoxic agents enhances the anti-tumor efficacy. Therefore, specific inhibition of the activation of Akt may be a valid approach to treating human malignancies and overcoming the resistance of cancer cells to radiation or chemotherapy.

Animals↗
PubMed2004

Role of autophagy in temozolomide-induced cytotoxicity for malignant glioma cells.

Autophagy is originally named as a process of protein recycling. It begins with sequestering cytoplasmic organelles in a membrane vacuole called autophagosome. Autophagosomes then fuse with lysosomes, where the materials inside are degraded and recycled. To date, however, little is known about the role of autophagy in cancer therapy. In this study, we present that temozolomide (TMZ), a new alkylating agent, inhibited the viability of malignant glioma cells in a dose-dependent manner and induced G2/M arrest. At a clinically achievable dose (100 microM), TMZ induced autophagy, but not apoptosis in malignant glioma cells. After the treatment with TMZ, microtubule-associated protein light-chain 3 (LC3), a mammalian homologue of Apg8p/Aut7p essential for amino-acid starvation-induced autophagy in yeast, was recruited on autophagosome membranes. When autophagy was prevented at an early stage by 3-methyladenine, a phosphatidylinositol 3-phosphate kinase inhibitor, not only the characteristic pattern of LC3 localization, but also the antitumor effect of TMZ was suppressed. On the other hand, bafilomycin A1, a specific inhibitor of vacuolar type H(+)-ATPase, that prevents autophagy at a late stage by inhibiting fusion between autophagosomes and lysosomes, sensitized tumor cells to TMZ by inducing apoptosis through activation of caspase-3 with mitochondrial and lysosomal membrane permeabilization, while LC3 localization pattern stayed the same. These results indicate that TMZ induces autophagy in malignant glioma cells. Application of an autophagy inhibitor that works after the association of LC3 with autophagosome membrane, such as bafilomycin A1, is expected to enhance the cytotoxicity of TMZ for malignant gliomas.

Adenine↗
PubMed2004

Light-activated gene transduction of recombinant adeno-associated virus in human mesenchymal stem cells.

Deficiencies in skeletal tissue repair and regeneration lead to conditions like osteoarthritis, osteoporosis and degenerative disc disease. While no cure for these conditions is available, the use of human bone marrow derived-mesenchymal stem cells (HuMSCs) has been shown to have potential for cell-based therapy. Furthermore, recombinant adeno-associated viruses (rAAV) could be used together with HuMSCs for in vivo or ex vivo gene therapy. Unfortunately, the poor transduction efficiency of these cells remains a significant obstacle. Here, we describe the properties of ultraviolet (UV) light-activated gene transduction (LAGT) with rAAV in HuMSCs, an advance toward overcoming this limitation. Using direct fluorescent image analysis and real-time quantitative PCR to evaluate enhanced green fluorescent protein (eGFP) gene expression, we found that the optimal effects of LAGT with limited cytotoxicity occurred at a UV dose of 200 J/m(2). Furthermore, this UV irradiation had no effect on either the chondrogenic or osteogenic potential of HuMSCs. Significant effects of LAGT in HuMSCs could be detected as early as 12 h after exposure and persisted over 21 days, in a time and energy-dependent manner. This LAGT effect was maintained for more than 8 h after irradiation and required only a 10-min exposure to rAAV after UV irradiation. Finally, we show that the production of secreted TGFbeta1 protein from rAAV-TGFbeta1-IRES-eGFP infected to HuMSCs is highly inducible by UV irradiation. These results demonstrate that LAGT combined with rAAV is a promising procedure to facilitate gene induction in HuMSCs for human gene therapy.

Cells, Cultured↗
PubMed2004

Excess accumulation of body fat is related to dyslipidemia in normal-weight subjects.

OBJECTIVE: To assess the relationship of fat mass (FM) and its distribution to hypertension and dyslipidemia in normal-weight Japanese individuals. DESIGN: Cross-sectional study. SUBJECTS: Apparently healthy Japanese subjects with a body mass index (BMI) between 20 and 23.5 kg/m(2) (265 males and 741 females, age 21-69 y). MEASUREMENTS: BMI, waist circumference (WC), waist-hip ratio (WHR), systolic and diastolic blood pressure, serum levels of total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-C) and triglyceride (TG) were measured. Low-density lipoprotein-cholesterol (LDL-C) was calculated by the Friedewald formula. Percentage fat mass (%FM) and trunk fat mass-leg fat mass ratio (FM(trunk)/FM(legs)) were obtained by dual-energy X-ray absorptiometry. RESULTS: WC, WHR, %FM and FM(trunk)/FM(legs) were significantly correlated with TC, LDL-C, HDL-C and TG with the tendency of FM(trunk)/FM(legs) to show the strongest correlations. For %FM and FM(trunk)/FM(legs) in both sexes, odds ratios (ORs) of the third tertiles with respect to the first tertiles increased for LDL-C elevation, TG elevation and dyslipidemia. In males, ORs of the third tertiles of WC were significantly high for LDL-C elevation and dyslipidemia whereas those of WHR were high for TG elevation and dyslipidemia. ORs of the third tertiles of WC and WHR were significantly high for TG elevation in females. BMI was not associated with the risk of abnormal lipid levels. ORs for hypertension showed significant increases in none of the variables of obesity. CONCLUSIONS: Excess accumulation of FM, especially to the upper body, was related to dyslipidemia in normal-weight subjects. Simple anthropometric variables, WC and WHR, may be useful for screening and management of dyslipidemia in these subjects.

Absorptiometry, Photon↗
PubMed2004

Expression of RUNX3 protein in human gastric mucosa, intestinal metaplasia and carcinoma.

BACKGROUND: Human runt-related transcription factor gene 3 (RUNX3) is considered as a possible candidate of tumour suppressor gene in human gastric carcinoma. MATERIALS AND METHODS: To investigate the RUNX3 protein expression in human gastric mucosa and carcinoma, we generated a polyclonal antibody, AS251, which recognized amino acid sequences from 251 to 266 of human RUNX3. The AS251 antibody was immunoreactive with only RUNX3 protein, but not with RUNX1 and RUNX2. The AS251-antibody was available for Western blotting and immunohistochemistry using paraffin-embedded specimens. RESULTS: Western-blot analysis revealed that three (MKN-1, -7 and -45) of six human gastric carcinoma cell lines variably expressed RUNX3 protein, consistent with the expression pattern of RUNX3 mRNA reported previously by Li et al. (Cell 2002;109:113-24). Immunohistochemistry disclosed RUNX3 protein in most chief cells and a few gastrin-containing G cells in normal mucosa, but not in intestinal metaplasia and carcinoma cells. CONCLUSIONS: These data suggest that RUNX3 may play a physiologic role in chief cells and G cells in gastric mucosa, and that suppression of RUNX3 expression in intestinal metaplasia and carcinoma of human stomach may be implicated in gastric carcinogenesis.

Amino Acid Sequence↗
PubMed2004

Primary lateral sclerosis presenting parkinsonian symptoms without nigrostriatal involvement.

We encountered three patients with primary lateral sclerosis (PLS) showing bradykinesia, frozen gait, and severe postural instability, as well as slowly progressive spinobulbar spasticity. Cranial magnetic resonance (MR) imaging showed precentral gyrus atrophy. Central motor conduction was markedly prolonged or failed to evoke a response. Positron emission tomography (PET) showed significant reduction of [18F]fluoro-2-deoxy-D-glucose uptake in the area of the precentral gyrus extending to the prefrontal, medial frontal, and cingulate areas. No abnormalities were seen in the nigrostriatal system with PET using [18F]fluorodopa or [11C]raclopride or with proton MR spectroscopy. Thus, widespread prefrontal, medial, and cingulate frontal lobe involvement can be associated with the parkinsonian symptoms in PLS.

Adult↗
PubMed2004

G2 chromatid damage and repair kinetics in normal human fibroblast cells exposed to low- or high-LET radiation.

Radiation-induced chromosome damage can be measured in interphase using the Premature Chromosome Condensation (PCC) technique. With the introduction of a new PCC technique using the potent phosphatase inhibitor calyculin-A, chromosomes can be condensed within five minutes, and it is now possible to examine the early damage induced by radiation. Using this method, it has been shown that high-LET radiation induces a higher frequency of chromatid breaks and a much higher frequency of isochromatid breaks than low-LET radiation. The kinetics of chromatid break rejoining consists of two exponential components representing a rapid and a slow time constant, which appears to be similar for low- and high-LET radiations. However, after high-LET radiation exposures, the rejoining process for isochromatid breaks influences the repair kinetics of chromatid-type breaks, and this plays an important role in the assessment of chromatid break rejoining in the G2 phase of the cell cycle.

Animals↗
PubMed2004

Vascularised bone graft from the base of the second metacarpal for refractory nonunion of the scaphoid.

A vascularised bone-graft procedure from the base of the second metacarpal was performed in 14 patients with nonunion of the scaphoid. There were 11 men and three women with a mean age of 22 years. In eight patients, who had dorsiflexed intercalated segment instability (DISI), an open wedge was formed at the site of nonunion, and the vascular pedicle was grafted from the volar side. In the six patients without DISI, transplantation was carried out through the same dorsal skin incision. Complete bony union was obtained in all patients after a mean post-operative period of 10.2 weeks, and DISI was corrected in all affected patients. According to Cooney's clinical scoring system, the results were excellent in five, good in six, and fair in three patients. Because of its technical simplicity and the limited dissection needed, the procedure should be considered for the primary surgical treatment of patients with nonunion of the scaphoid.

Adolescent↗
PubMed2004

Malignant ameloblastic fibro-odontoma in a dog.

An 11-year-old male Collie was presented with a swelling of the face caused by tumor masses arising from the gingiva. Postmortem examination revealed metastases to the lymph nodes, lung, liver, and orbital cavity. Histologically, the tumor represented a combination of fibrosarcomatous proliferation, pulpal mesenchyme, and undifferentiated odontogenic epithelium, with a follicular or plexiform growth pattern. In addition, the follicular areas of the tumor showed a biphasic character, and there were numerous apoptotic cells in plexiform areas. Furthermore, acidophilic material resembling dysplastic dentine or enamel matrix was observed in the metastatic lesion in the lung. Based on the histological characters, the present case was diagnosed as malignant ameloblastic fibro-odontoma. This study is the first known description of a possible malignant ameloblastic fibro-odontoma in a dog with metastasis to distant organs.

Animals↗
PubMed2004

A selective cyclooxygenase-2 inhibitor, NS398, inhibits cell growth and induces cell cycle arrest in the G2/M phase in human esophageal squamous cell carcinoma cells.

It is well known that cyclooxygenase (COX) -2 is expressed in a variety of human malignant solid tumors, associated with tumor angiogenesis, cell proliferation and inhibition of apoptosis. Here, we examined the effect of NS398, a selective COX-2 inhibitor, on two human esophageal squamous cell carcinoma (SCC) cell lines, TE-1 and TE-12. Western blot analysis confirmed the expression of COX-2 in TE-12, but not in TE-1. Treatment with 100microM NS398 suppressed the cell viability in TE-12 (48.6% of control) after 48 hours, in contrast to showing no effects in TE-1. The apoptotic index was extremely low in both cell lines after the treatment. NS398 clearly increased the number of cells in the G2/M phase and decreased the cells in the G1 and S phases in TE-12, but not TE-1. A pre-G1 fraction was not noted in either cell line. Moreover, TE-12 cells showed a decrease in the expression levels of cyclin B1 and an increase in p27Kip1. These findings suggest that NS398 inhibits cell growth and induces G2/M arrest in human SCC cells expressing COX-2.

Apoptosis↗
PubMed2004

Detection and quantification of circulating tumor cells in patients with esophageal cancer by real-time polymerase chain reaction.

Polymerase chain reaction (PCR) amplification was used for detecting circulating tumor cells. However, PCR was so sensitive that it detected a very low level of mRNA with no relevance to tumor cells. We analyzed the degree of micro-tumor spread in esophageal cancer patients using quantitative PCR. Samples were collected from 28 patients and 35 controls. Real-time quantitative PCR (LightCycler) was employed for the detection of carcinoembryonic antigen (CEA) and cytokeratin 20 (CK-20). In the CEA and CK-20 mRNA assays, 7 and 3 out of 28 patients, respectively, showed higher mRNA levels in peripheral blood than the normal range based on values of controls (mean+/-2SD). Eleven out of 19, 4 out of 14, and 2 out of 5 patients showed higher CEA mRNA levels in the samples from tumor drainage vein, costal bone marrow, and thoracic duct lymph, respectively. One of the 7 patients who showed higher CEA mRNA levels in pretreatment peripheral blood is currently free from disease. These findings reveal that quantitative PCR can discriminate high levels of cancer-specific expression from low levels of illegitimate expression in blood. They also suggest that the identification of circulating tumor cells by the CEA mRNA assay is a reliable means of predicting early recurrence.

Aged↗
PubMed2003

Persistence of viral RNA segments in the central nervous system of mice after recovery from acute influenza A virus infection.

One-hundred thirty-seven BALB/c mice were intranasally inoculated with neurotropic avian influenza A virus (H5N3). Thirty-nine of these mice died within 16 days post-inoculation (PID) and 98 of the mice recovered from the infection. To investigate whether viral antigens and genomes persist in the central nervous system (CNS) of recovered mice, immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) methods were performed. Histopathologically, mild interstitial pneumonia and non-suppurative encephalomyelitis restricted to the basal part of the frontal lobe of the cerebrum, brain stem and thoracic spinal cord were observed in BALB/c mice until 40 PID. Small amounts of viral antigens were detected in the brain and spinal cord and some viral RNA segments (NA, NP, M, PA, HA, NS, PB1) were intermittently detected in the CNS until 48 PID. Immunosuppression of these mice by dexamethazone (DEX) treatment did not increase the frequency of detection of the lesions, viral antigens or genomes. These findings suggest that viral genomes of neurovirulent influenza virus persist with restricted transcriptive activity in the CNS of the mice even after clinical recovery from the infection.

Animals↗
PubMed2003

Inhibition of telomerase activity in malignant glioma cells correlates with their sensitivity to temozolomide.

Temozolomide (TMZ, 3,4-dihydro-3-methyl-4-oxoimidazo [5,1-d]-as-tetrazine-8-carboxamide) is a new alkylating agent with promising antitumour efficacy for malignant gliomas. The resistance of tumour cells to TMZ is primarily associated with levels of the alkylguanine alkyltransferase (AGT). O(6)-benzylguanine (O(6)-BG), an inhibitor for AGT, reduced resistance to TMZ. Recently, it has been demonstrated that chemosensitivity of tumour cells is related to a decline in telomerase activity. However, it is unknown if TMZ sensitivity of malignant glioma cells correlates with telomerase. In this study, using malignant glioma cells with low levels of AGT (U373-MG and U87-MG) and high levels of AGT (T98G), we investigated the association among AGT, telomerase, and TMZ sensitivity. U373-MG and U87-MG cells were sensitive to TMZ (IC(50) for a 2-day treatment=100 microM), while T98G cells were resistant to TMZ (IC(50) for a 2-day treatment >500 microM). Treatment with TMZ (100 microM) suppressed telomerase activity in U373-MG and U87-MG cells in a time-dependent manner, but not in T98G cells. The downregulation of telomerase activity in U373-MG and U87-MG cells was due to inhibition of the human telomerase reverse-transcriptase (hTERT) gene expression at the transcriptional level. This inhibitory effect was induced by interfering with transcription factor Sp1 binding sites of the hTERT core promoter. Interestingly, O(6)-BG not only sensitised T98G cells to TMZ, but also suppressed telomerase activity. These findings suggest that response of malignant glioma cells to TMZ can be monitored by reduction in telomerase activity. Therefore, quantification of telomerase activity during or after treatment with TMZ may be a useful marker to detect treatment efficacy.

Antineoplastic Agents, Alkylating↗
PubMed2003

Transverse-momentum spectra in Au+Au and d+Au collisions at sqrt[s(NN)]=200 GeV and the pseudorapidity dependence of high-p(T) suppression.

We present spectra of charged hadrons from Au+Au and d+Au collisions at sqrt[s(NN)]=200 GeV measured with the BRAHMS experiment at RHIC. The spectra for different collision centralities are compared to spectra from p+(-)p collisions at the same energy scaled by the number of binary collisions. The resulting ratios (nuclear modification factors) for central Au+Au collisions at eta=0 and eta=2.2 evidence a strong suppression in the high p(T) region (>2 GeV/c). In contrast, the d+Au nuclear modification factor (at eta=0) exhibits an enhancement of the high p(T) yields. These measurements indicate a high energy loss of the high p(T) particles in the medium created in the central Au+Au collisions. The lack of suppression in d+Au collisions makes it unlikely that initial state effects can explain the suppression in the central Au+Au collisions.

Journal Article↗