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Biomedical subjects

Minoru Ueda

Publications and source records attributed to Minoru Ueda.

At least 73 records · Page 4Linked to original sources
PubMed2003

Improvement of transduction efficiency of recombinant adenovirus vector conjugated with cationic liposome for human oral squamous cell carcinoma cell lines.

Adenovirus (Ad) vectors are commonly used in gene therapy trials because of their efficiency in gene transfer. However, their use is limited by immune responses that reduce transgene expression and decrease the efficiency of repeated vector administration. In this study, the efficacy of gene transduction and the tumor-cell killing effect on four human oral (SAS, HSC-2, HSC-3, HSC-4) and one murine squamous cell carcinoma cell (SCC-7, a kind gift of Dr. M. Hiraoka, Kyoto University) lines in vitro with Ad vector conjugated with catioic liposome (Ad/SUV) was evaluated. Ad/SUV resulted in two to five-fold over higher transduction efficiency in four human and one murine cell lines in vitro than Ad vector alone. The optimal Ad-SUV ratio was determined as 10(6) pfu of Ad vector with 1 micromol SUV. Ad/SUV showed more tumor-cell killing effect than Ad vector alone. Furthermore, the shielding effects of Ad vector with Ad/SUV from neutralizing antibody were evaluated. We also found that Ad/SUV is less susceptible to inactivation by neutralizing antibodies in vitro. The efficacy of gene transduction with Ad vector was blocked more than 70% with neutralizing serum, while Ad/SUV retained approximately 50% of the control activity in vitro. On the basis of these results, the anti-tumor effect with suicide gene therapy using Ad/SUV in vivo was evaluated. Three injections of Ad/SUV showed the inhibition of tumor growth compared with control in vivo. Our results suggested that an enhanced anti-tumor effect on human oral squamous cell carcinoma would be obtained with repeated administrations of Ad/SUV.

Adenoviridae↗
PubMed2003

Proliferation and stratification of keratinocyte on cultured amniotic epithelial cells for tissue engineering.

Human amniotic epithelial cells (HAECs) are formed from amnioblasts, separated from the epiblast at about the 8th day after fertilization. Recent studies suggest that HAECs can produce various biologically active substances. In this study, the effects of cultured HAECs on keratinocytes were investigated. First of all, the effect of the medium conditioned by cultured HAECs on the proliferation of keratinocytes was examined. The conditioned medium significantly enhanced the proliferation (P<0.05). Next, the effect of co-culture with HAECs was also examined. The keratinocytes formed a stratified epithelium on day 7 after the start of co-culture. The cultured epithelium formed by the co-culture was five to six layers thick, could be detached by dispase treatment, and had sufficient strength as a sheet. These results suggest that HAECs will be a novel supplemental material for the tissue engineering of skin.

Journal Article↗
PubMed2003

Albiziahexoside: a potential source of bioactive saponin from the leaves of Albizzia lebbeck.

Albiziahexoside (1), a new hexaglycosylated saponin, was isolated from leaves of Albizzia lebbeck. Saponin 1, which is an analog of cytotoxic albiziatrioside A (2), did not show cytotoxicity. However, 1 is a potential source of 2 and related bioactive saponins for medicinal use because leaves, which can be regenerated after collection, contain 1 in substantial quantity.

Albizzia↗
PubMed2003

Selective hyperthermia using magnetoliposomes to target cervical lymph node metastasis in a rabbit tongue tumor model.

The effect of hyperthermia on cervical lymph node metastasis of VX7 tongue cancer in female Japanese white rabbits was investigated. Magnetoliposomes (MLs) with a neutral surface charge and a size of 94.1 nm were used as heating mediators. MLs were injected into the tongue 20 days after tumor transplantation, and we examined whether they reached the metastatic deep cervical lymph node. The highest magnetite concentration 24 h after ML injection was detected in the lymph node, followed by tongue, spleen, blood, and liver. Rabbits were separated into three groups: group I as the control; group II with ML injection alone; and group III with ML injection and hyperthermia 24 h after ML injection, generated by applying an alternating magnetic field (118 kHz, 384 Oe) to the neck region. The hyperthermic effect was evaluated in terms of the percentage of necrosis in proportion to the metastatic tumor and the apoptotic index (AI), defined as the ratio of TUNEL-positive cells. The temperature of lymph nodes in group III reached over 44 degrees C. The mean area of necrosis in group III was 58.0%, which was significantly higher than that in group I (19.6%) or group II (20.4%). The AI in group III was 22.9%, significantly higher than in group I (1.67%) or II (1.42%). The difference between group I and II was not statistically significant. Group III tumor sites around MLs showed necrosis or apoptosis-positive cells induced by hyperthermia. These results indicate that MLs injected into the tongue can target cervical lymph node metastases and accumulate there at concentrations sufficient to generate therapeutically effective temperatures.

Animals↗
PubMed2003

[Regeneration of tooth and periodontal tissue using tissue engineering concepts].

In the context of minimally invasive surgery, the next logical step is to provide a biological replacement for missing tissue without the need for a harvesting operation. Tissue engineering is defined as the fabrication of living parts for the body from cells in the laboratory. Donor cells such as stem cell or cultivated, differentiated cells are seeded on a appropriately configurated scaffold replicating extracellular matrix. Growth factors are added to the in-vitro system to encourage stem cell proliferation. The engineered structure is then transplanted to the recipient. In this article, the regeneration strategies for tooth and periodontal tissue using tissue engineering concepts. Culture expanded mesenchymal stem cell is useful for periodontal tissue and tooth regeneration with bioabsorbable matrix such as b-TCP and collagen fiber. In the near future, these regenerated tissue will be accepted in clinical situations.

Animals↗
PubMed2003

Cell death of human oral squamous cell carcinoma cell line induced by herpes simplex virus thymidine kinase gene and ganciclovir.

Suicide gene therapy combining herpes simplex virus thymidine kinase gene (HSVtk) and ganciclovir (GCV) is one strategy for the treatment of head and neck squamous cell carcinoma (HNSCC). The purpose of this study is to determine the mechanism of cell death that occurs in suicide gene therapy using HSVtk and GCV and to assess the safety of that therapy. The human oral squamous cell carcinoma cell line SAS was treated with adenovirus vector containing HSVtk gene (AdHSVtk) and GCV in vitro. Morphological changes including chromatin condensation, cell shrinkage, blebbing of cell membrane, and ballooning formations were observed. Changes in the localization of phospholipids in the cell membrane were also observed. The results of flow cytometry showed a maximum of about 65% of cells in the early phase of apoptosis. In addition, DNA fragmentation was investigated using the TUNEL method in vivo. Nude mice (BALB/c AJD(-nu-), aged 4 weeks) were implanted with SAS and treated with AdHSVtk and GCV. Tumor sections were then observed. The treatment group was confirmed to have DNA fragmentation-positive cells. These results suggest that suicide gene therapy using AdHSVtk and GCV led to apoptosis of the oral squamous cell carcinoma cell line.

Adenoviridae↗
PubMed2003

Transglutaminase-mediated gelatin matrices incorporating cell adhesion factors as a biomaterial for tissue engineering.

The goal of this work was to develop a novel biomaterial to be used for either wound dressing or as a scaffold for tissue engineering. The biodegradable hydrogels were prepared through cross-linking of gelatin with transglutaminase (TGase) in an aqueous solution. We found that the concentrations of 5 wt% gelatin and 1 unit/ml TGase were optimum for the proliferation of NIH/3T3 fibroblasts. Then, we investigated whether the cell proliferation was enhanced by incorporation of cell adhesion factors into the gelatin hydrogels. Since vitronectin and fibronectin can bind with gelatin by the action of TGase, we added these cell adhesion proteins into the gelatin hydrogels. The hydrogels incorporating these cell adhesion proteins significantly enhanced cell proliferation compared with the gelatin hydrogels without these proteins (p<0.05). Two types of synthetic Arg-Gly-Asp (RGD) peptides, RGDLLQ and RGDLLG were also added to the gelatin solution where RGDLLQ is a substrate of TGase by virtue of a glutamine (Q) residue with an epsilon-amino group and RGDLLG is not. These two RGD peptides enhanced cell proliferation, but RGDLLQ significantly enhanced the proliferation compared with RGDLLG (p<0.05). These results suggest that T-Gase-mediated incorporation of cell adhesion factors into gelatin matrices enhanced cell proliferation and this novel biomaterial is a potent tool for wound dressing or tissue engineering.

Journal Article↗
PubMed2002

Vacuolar-type H(+)-ATPase inhibitory activity of synthetic analogues of the concanamycins: is the hydrogen bond network involving the lactone carbonyl, the hemiacetal hydroxy group, and the C-19 hydroxy group essential for the biological activity of the concanamycins?

Synthetic analogue of the concanamycins, which lacks the hydrogen bond network existing in the concanamycin structure, retains vacuolar-type H(+)-ATPase (V-ATPase) inhibitory activity and induces apoptosis to cancer cells that overexpressing epidermal growth factor receptors (EGFR).

Anti-Bacterial Agents↗
PubMed2002

Midkine, a heparin-binding growth factor, promotes growth and glycosaminoglycan synthesis of endothelial cells through its action on smooth muscle cells in an artificial blood vessel model.

To study the interactions between smooth muscle cells and endothelial cells in vitro, we developed an artificial blood vessel model, which consisted of collagen gel containing human aortic smooth muscle cells and human umbilical vein endothelial cells grown on the gel. The blood vessel model was utilized to investigate the role of midkine, a heparin-binding growth factor, in the intercellular interactions that are important in angiogenesis. In the blood vessel model, midkine induced stratification of the endothelial cells and increased their proliferation and glycosaminoglycan synthesis. However, midkine had no effect on the smooth muscle cells or endothelial cells when they were cultured separately. Increased proliferation of the endothelial cells was also attained by coculturing them with smooth muscle cells in the presence of midkine or culturing endothelial cells with the conditioned medium of the smooth muscle cells, which had been treated with midkine. These experiments indicate that the target of midkine was smooth muscle cells, which secreted factor(s) acting on the endothelial cells. We identified interleukin-8 as one such factor; the synthesis of interleukin-8 by the smooth muscle cells was increased by exposure to midkine, and anti-interleukin-8 inhibited the midkine action. Furthermore, interleukin-8 caused stratification of the endothelial cells in the blood vessel model. These results provided evidence that midkine is one of the factors involved in epithelial-mesenchymal interactions.

Aorta↗
PubMed2002

Low incidence of p53 mutations in well-differentiated tongue squamous cell carcinoma in Japan.

BACKGROUND: Despite an increasing number of patients suffering from squamous cell carcinomas of the tongue, little is known about the molecular mechanisms involved in the origin and development of these neoplasms. METHODS: We screened microdissected tongue squamous cell carcinoma (TSC) specimens from 28 consecutive, previously untreated, Japanese patients for mutations in the p53 tumor-suppressor gene single-strand conformation polymorphism analysis (exons 5, 6, 7, 8) and direct genomic sequencing. RESULTS: Among them, 24 tumor specimens were well differentiated, three moderately and one poorly differentiated, according to the WHO classification. Mutations in the p53 tumor-suppressor gene were detected in only two out of the 28 (7%) tumor specimens. One was well differentiated and the other was poorly differentiated. CONCLUSIONS: Our results suggest that p53 gene mutations are less frequent in well differentiated TSC. These results indicate that mutations in the p53 gene may not be strongly involved in the development of well differentiated TSC.

Adult↗
PubMed2002

Tissue-engineered bone using mesenchymal stem cells and a biodegradable scaffold.

Bone marrow has been shown to contain a population of rare cells capable of differentiating to the cells that form various tissues. These cells, referred to as mesenchymal stem cells (MSCs), are capable of forming bone when implanted ectopically in an appropriate scaffold. The aim of this study was to investigate the potential of a new beta-tricalcium phosphate (beta-TCP) as a scaffold and to compare the osteogenic potential between beta-TCP and hydroxyapatite (HA). The beta-TCP and HA loaded with MSCs were implanted in subcutaneous sites and harvested at 1, 2, 4, and 8 weeks after implantation for biochemical and histological analysis. Biochemically, in both beta-TCP and HA composites, the alkaline phosphatase activity in the composites could be detected and was maintained at a high level for 8 weeks. In the histological analysis, active bone formation could be found in both the beta-TCP and HA composites. These findings suggest that beta-TCP could play a role as a scaffold as well as HA. The fabricated synthetic bone using biodegradable beta-TCP as a scaffold in vivo is useful for reconstructing bone, because the scaffold material is absorbed several months after implantation.

Absorbable Implants↗
PubMed2002

Prognostic evaluation of preoperative thermochemoradiotherapy for N(3) cervical lymph node metastases of oral cancer.

OBJECTIVE: The purpose of this study was to evaluate the clinical efficacy, histopathological efficacy, and response to preoperative thermochemoradiotherapy for N(3) cervical lymph node metastases of oral cancer. METHODS: Preoperative thermochemoradiotherapy was performed in 8 patients with oral cancer and N(3) cervical lymph node metastasis. These patients underwent four-weekly sessions of hyperthermia, combined with radiotherapy (40 Gy) as well as chemotherapy with cisplatin (CDDP; 100 mg/m2), all prior to surgery. Radical neck dissection was performed 4 weeks after completion of preoperative thermochemoradiotherapy. RESULTS: The preoperative treatment of cervical lymph node metastases yielded a partial response in 6 patients, while 2 patients demonstrated no change. Histopathologically, grade III was detected in 1, grade IIb in 4 and grade IIa in 3 patients after surgery, according to the criteria of Shimosato. The follow-up period ranged from 13 to 64 months (mean 34). Of the 8 patients, 2 died (1 of lymph node metastasis and 1 had metastasis to a distant site), and 6 patients were alive at the last follow-up, with the longest postoperative disease-free survival being 63 months. The 5-year cumulative survival rate was 70.0%. CONCLUSION: These results indicate that preoperative thermochemoradiotherapy is a promising modality for patients with N(3) cervical lymph node metastasis of oral cancer.

Adult↗
PubMed2002

Transport of D-glucose across cultured stratified cell layer of human oral mucosal cells.

To evaluate the role of several specialized mechanisms for D-glucose transport in human oral mucosa, a cultured stratified cell layer derived from human oral mucosa was employed. Although this culture system has been used for reconstructive surgery, we, for the first time, tried to apply this system to the evaluation of nutrients and drug transport. Cell number and transepithelial electrical resistance (TEER) reached steady state 7-8 days after inoculation on the Transwell and TEER values at steady state were 130-140 ohm cm2, which was higher or lower than that of small intestine or Caco-2 cells, respectively. The transport studies were carried out using the cultured epithelium on the Transwell. The transport of D-glucose across the cultured stratified layer of oral epithelial cells was much more extensive than L-glucose, and was inhibited by 2-deoxy-D-glucose, a substrate of facilitative glucose transporters, and 2-methyl-D-glucoside, a specific substrate of a Na/glucose cotransporter (SGLT1). The results indicate that the sugar transporters function not only to take up D-glucose by the epithelial cells but also to transport the sugar across the stratified epithelial layer.

Biological Transport, Active↗
PubMed2002

Leaf-closing substance in Leucaena leucocephala.

Potassium (2R,3R)-2,3,4-trihydroxy-2-methylbutanoate (1) was identified as a leaf-closing substance in the nyctinastic plant, Leucaena leucocephala. Compound 1 showed strong leaf-closing activity toward L. leucocephala and was not effective against other nyctinastic plants. The potassium ion was indispensable for the bioactivity of 1. Compound 1 gradually lost its bioactivity because of the exchange of the counter cation during isolation. A leaf-opening substance was also observed in the same plant.

Fabaceae↗
PubMed2002

[Injectable bone].

Tissue engineering applies the principles of biology and engineering to the development of functional substitutes,for example 1) cells, 2) scaffolds, 3) some cytokines, for lost tissues. The meaning of this bone regeneration is that it decreases the needed tissues and burden of patients. In this time, we applied to mesenchymal stem cells (MSCs) from the own bone marrow as cell sources. MSCs are thought to be multipotent cells that can replicate. And we also used a beta-tricalcium phosphate (beta-TCP) as a scaffold and fibrin glue as materials to regenerate a injectable bone and we injected into the subcutaneous space on the dorsum of the rat. After 8 weeks of implantation, it could be confirmed newly formed bone and fibrin glue functioned as a injectable materials without loosing the cell activity and the proliferation of MSCs. Next we applied Platelet Rich Plasma (PRP) to improve the ability of osteogenesis. PRP contains some cytokines and are expected to promote the increase of osteogenesis. The merit is not immunity rejection from autologous blood collected in the immediate preoperative period. The admixtures of PRP or fibrin glue have fluidity and gel-like consistency as the thrombin mixing. They can be injected with a syringe in tissues. We named this "Injectable Bone". According to the histological observations, the MSCs with PRP were well formed mature bone and neovascularization compared with control (defect only) after 8 weeks implantation. These results demonstrated that the mixture of MSCs and PRP were useful as injectable bone substitute and its ability of bone regeneration is almost equal to autogenous particulate cancellous bone and marrow (PCBM).

English Abstract↗
PubMed2002

[Sonic hedgehog].

We investigated ectopic cartilage and bone formation induced by transplantation of cells which were transfected with Sonic hedgehog (Shh) cDNA encoding amino-terminal peptide for gene therapy in bone regeneration. These results indicated Shh regulated early chondrogenesis and stimulation of prechondrocytes, and consequently the synergistic effects of Shh and BMP induced bone formation in vivo. In the future, further study of transfection of Shh combined with other gene groups regulating bone formation, or other bone-stimulating factors, or using new type of scaffold will be needed to confirm clinical application.

English Abstract↗