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Biomedical subjects

M Takizawa

Publications and source records attributed to M Takizawa.

At least 19 recordsLinked to original sources
PubMed2006

Photoemission from buried interfaces in SrTiO3/LaTiO3 superlattices.

We have measured photoemission spectra of SrTiO3/LaTiO3 superlattices with a topmost SrTiO3 layer of variable thickness. A finite coherent spectral weight with a clear Fermi cutoff was observed at chemically abrupt SrTiO3/LaTiO3 interfaces, indicating that an "electronic reconstruction" occurs at the interface between the Mott insulator LaTiO3 and the band insulator SrTiO3. For SrTiO3/LaTiO3 interfaces annealed at high temperatures (approximately 1000 degrees C), which leads to Sr/La atomic interdiffusion and hence to the formation of La(1-x)Sr(x)TiO3-like material, the intensity of the incoherent part was found to be dramatically reduced whereas the coherent part with a sharp Fermi cutoff was enhanced due to the spread of charge. These important experimental features are well reproduced by layer dynamical-mean-field-theory calculation.

Journal Article↗
PubMed2005

Trial of remote telemedicine support for patients with chronic respiratory failure at home through a multistation communication system.

To create and test a multistation telemedicine support system, three remote locations were connected: the homes of two patients with chronic respiratory failure, the hospital of the attending physician, and the hospital of the pulmonary specialist. Real-time connections were set up between the three locations. Medical history and biologic variables were noninvasively recorded, including blood pressure, arterial oxygen saturation, three-lead electrocardiogram, and end-tidal carbon dioxide. Both physicians shared in these data real-time. If necessary, the respiratory specialist could provide medical advice to the attending physician based on the patient's condition. The trial program resulted in the same information being exchanged remotely using the multi-station telemedicine system that would be exchanged in a direct, face-to-face encounter. This result, together with the improvement in quality of life and the establishment of appropriate treatment and cooperation between the respiratory specialist and attending physician, suggests our system can be considered useful and promising for further use.

Aged↗
PubMed2005

[Completion pneumonectomy after 4 times of resections for metastatic lung tumors from rectal carcinoma].

We report a case of completion pneumonectomy after 4 times of metastasectomy for metastatic lung tumors from rectal carcinoma. A 63-year-old man underwent Miles' operation for advanced rectal carcinoma. Forty-seven months after the operation, bilateral metastasis was appeared, and bilateral metastasectomy was performed. After the resection, 3 times of metastasectomy were performed during 40 months. Follow-up X-ray and computed tomography (CT) showed abnormal shadow in his left hilum of lung. Completion pneumonectomy with mediastinal lymph node sampling was performed. He is still alive without recurrence 4 years after first thoracotomy. Repeated pulmonary resection can lead to good outcome for selective patients with metastatic colorectal carcinoma, and repeated surgery can be useful for pulmonary recurrences after thoracotomy.

Humans↗
PubMed2003

[Catamenial pneumothorax in a young patient diagnosed by thoracoscopic surgery; report of a case].

A 16-year-old woman presented with chest pain on 2 days before the onset of menstruation and was referred to our hospital because of a pneumothorax. She was diagnosed as spontaneous penumothorax and surgical treatment was performed. Thoracoscopy revealed the presence of multiple blueberry spots near central tendon of the diaphragm and little pleural effusion. No other abnormal lesions were found in the left pleural cavity and left lung. Thoracoscopic biopsy and coagulation of the lesions were successfully performed. Histological findings of biopsied specimen did not contradict as an endometoriosis and catamenial pneumothorax was diagnosed. CA 125 level of the pleural effusion had increased to 99.2 U/ml. Because she was young, she did not receive a systemic hormonal therapy.

Adolescent↗
PubMed2003

[Left superior segmental resection for lung cancer with anomalous branching of the left A4 + 5; report of 2 cases].

We experienced with two cases of left superior segmental resection for lung cancer with the left A4 + 5 which arose from pars mediastinalis. Left superior segmental resection was performed on a 67-year-old female and an 81-year-old male. In both cases we divided A4 + 5 temporarily and anastomosed to pars interlobaris of the left pulmonary artery. As a result, it was able to perform safe division of bronchus. In cases with A4 + 5 arising from pars mediastinalis, operation is difficult and risky because A4 + 5 locates in front of the left upper lobe bronchus. It is safer to reconstruct A4 + 5 on pars interlobaris of the left pulmonary artery in such cases.

Adenocarcinoma↗
PubMed2002

Effect of HEMA on bonding of Er:YAG laser-irradiated bovine dentine and 4-META/MMA-TBB resin.

The purpose of this study was to evaluate the priming effect of 2-hydroxyethylmetaclirate (HEMA) following acid treatment on resin bonding to prototype Er:YAG laser-irradiated dentine. Extracted bovine dentine following laser irradiation was acid treated by aqueous solution of 10% citric acid (10-0) or 10% citric acid/3% ferric chloride (10-3), and additionally treated with 35% HEMA. Pre-treated dentines were bonded to the polymethyl-methacrylate (PMMA) rod with 4-META/MMA-TBB resin (Super Bond C & B) and miniaturized dumbbell-shaped bonded specimens were prepared. These specimens profiled for tensile bond testing and fractured surfaces were observed by scanning electron microscopy (SEM). Cross-sections of resin-dentine interface were also examined. The HEMA treatment following acid conditioned by 10-3 or 10-0 for both laser-irradiated and non-irradiated dentines was significantly higher than that without HEMA treatment. SEM view of a fractured specimen showed some cohesive failure in cured resin, but almost all of the fractured surface shows boundary failure between the penetrated resin and underlying dentine. A cross-sectional view of the interface showed a very thick hybrid layer between the hybridized dentine and underlying dentine. It was concluded that HEMA treatment following acid conditioning provided a slightly higher bond strength for both the Er:YAG laser-irradiated and non-irradiated dentines. However, the bond strength of Er:YAG laser irradiated dentine was significantly lower than that of the non-irradiated dentine.

Animals↗
PubMed2001

Endomucin is expressed in embryonic dorsal aorta and is able to inhibit cell adhesion.

Recent studies have suggested the existence of progenitors common to hematopoietic and endothelial cells, called hemangioblasts, in, for instance, embryonic dorsal aorta. To identify a membrane-bound or secretory molecule regulating early hematopoiesis, we screened a cDNA library from dorsal aortas of embryonic day (E) 10.5 mice by a signal sequence trap method and obtained a clone encoding a sialoprotein, endomucin-1. Immunohistochemistry revealed that the endomucin-1 transcript was specifically expressed in the endothelial cells of dorsal aorta of E10.5 mouse embryo. Overexpression of endomucin-1 strongly inhibited adhesion and aggregation of cells, including cultured endothelial cells from E10.5 dorsal aorta. These data suggest that endomucin-1 may play a role in detachment of hematopoietic cells from endothelium during early hematopoiesis.

Amino Acid Sequence↗
PubMed2001

Identification and molecular cloning of a novel brain-specific receptor protein that binds to brain injury-derived neurotrophic peptide. Possible role for neuronal survival.

Brain injury-derived neurotrophic peptide (BINP) is a synthetic 13-mer peptide that supports neuronal survival and protects hippocampal neurons in primary cultures from cell death caused by glutamate. We have developed a monoclonal antibody named mAb 6A22 against the 40-kDa BINP-binding protein, p40BBP. mAb 6A22 inhibits binding between BINP and rat brain synaptosomes and abolishes the protective effect of BINP. The antigen of mAb 6A22 should be the BINP-binding protein that mediates the neuroprotective action of BINP. Using an expression cloning approach with mAb 6A22, we isolated a cDNA encoding a novel receptor protein that shows binding activity of BINP. COS7 cells transfected with the cloned cDNA show binding of BINP and cell surfaces that are stained by 6A22. The mRNA for p40BBP is specific for the rat brain and is increased after birth. From immunohistochemical studies using mAb 6A22, p40BBP increased after kainic acid treatment in rat hippocampal neurons.

Amino Acid Sequence↗
PubMed2001

Presence of multiple HIV type 1 subtypes among mothers and children in Japan.

We collected blood samples from 70 HIV-1-infected pregnant women and 76 babies born to HIV-1-infected women in Japan, from 1989 to 1999. To analyze the genetic diversity of HIV-1 among mothers and children, we sequenced the C2-V3 regions of HIV-1 gp120. Phylogenetic tree analysis of these regions revealed that multiple HIV-1 subtypes, A, B, D, E, and G, were circulating among mothers and children in Japan. Thus, the genetic heterogeneity of HIV-1 among mothers and children in Japan is steadily increasing, although the number of cases remains small. Perhaps the longest term survivor, an 11-year-old child with a vertical HIV-1 subtype G infection in Japan, is one of our subjects.

Amino Acid Sequence↗
PubMed2001

Acute inhibition of proinsulin biosynthesis at the translational level by palmitic acid.

The effects of fatty acids on pancreatic beta cell are still controversial. Here, in order to determine whether free fatty acids acutely affect beta cell functions, we studied the effect of palmitic acid (PA) on proinsulin biosynthesis and insulin secretion using rat islets in vitro. Exposure of islets to PA for 1 h reduced glucose-stimulated proinsulin biosynthesis in a dose-dependent manner; in contrast, no change in insulin secretion was observed after 1 h incubation with PA. Furthermore, PA treatment did not cause any change of preproinsulin mRNA level during 1-h incubation period. Thus, our data indicate that PA primarily suppresses glucose-induced proinsulin biosynthesis within 1 h at the translational level.

Animals↗
PubMed2001

Correlation between the levels of circulating adhesion molecules and PR3-ANCA in Wegener's granulomatosis.

OBJECTIVE: The adhesion of neutrophils to the vascular endothelial cells appears to be important for the pathogenesis of vasculitis in Wegener's granulomatosis (WG). To determine the pathological significance of the neutrophil adhesion, we have examined and evaluated the relationships between the levels of adhesion molecules and proteinase-3 anti-neutrophil cytoplasmic antibodies (PR3-ANCA), and between the levels of TNF-alpha and disease activities in WG. METHODS: sELAM-1 and sICAM-1 in sera from WG and healthy donors were detected by ELISA. SLex and LFA-1 on neutrophils were detected by flow cytometry. RESULTS: The level of sICAM-1 was significantly higher in active WG than in inactive WG, tending to reflect individual disease activities. There was no difference in the level of sELAM-1 between WG patients and healthy donors. CONCLUSION: Our study suggests that the adhesion of neutrophils to the vascular endothelium is significant for the pathogenesis of the vasculitis in WG.

Adult↗
PubMed2001

An experimental study of the combined effect of radiotherapy and chemotherapy on head and neck squamous cell carcinoma cell line.

OBJECTIVE: We have reported clinical effects of radiotherapy combined with either CDDP or CBDCA for head and neck cancer. In this study, we examined the combined effects of either CDDP or CBDCA with irradiation on the cell lines established from tongue SCC. METHODS: The effects of irradiation, chemotherapy and the combined therapy on growth of the cell lines were examined respectively by the Alamar Blue assay. RESULTS: The combination of 0.1 and 0.25 microg/ml CDDP with four times exposure to I Gy 60Co. which did not affect the growth of the cell lines, suppressed the growth synergistically. The combination of 1.0 and 2.0 ) microg/ml of CBDCA with four times exposure to 1 Gy 60Co showed synergistically suppressive effects on the growth of the cell lines. CONCLUSION: It was suggested that the radiotherapy combined with the platium coordination complexes had a clinical usefulness in patients with head and neck cancer.

Aged↗
PubMed2001

Histological findings in biopsies from patients with cytoplasmic-antineutrophil cytoplasmic antibody (cANCA)-positive Wegener's granulomatosis.

OBJECTIVE: Currently Wegener's granulomatosis (WG) is diagnosed from clinical features, a test for antineutrophil cytoplasmic antibody (ANCA) and histological confirmation. The purpose of our study was to evaluate histological findings, in particular those in the biopsy samples of head and neck region. METHODS: Fifty-one biopsy specimens from 24 WG patients who were confirmed to be positive for cANCA were examined retrospectively. RESULTS: Only 12 biopsies out of 51 biopsies (24%) were diagnosed as typical of WG, and diagnosis could be confirmed in only 10 patients (42%) as typical of WG from the results of multiple biopsy specimens. CONCLUSION: In the diagnosis of WG. biopsy can be utilized restrictedly only in the cases when cANCA is negative or clinical symptoms are atypical of WG.

Adolescent↗
PubMed2001

Resin bonding to Er: YAG laser-irradiated dentin: combined effects of pre-treatments with citric acid and glutaraldehyde.

The purpose of this study was to evaluate the combined effects of citric acid and glutaraldehyde (GA) on the resin bonding to Er: YAG laser-irradiated dentin. Bovine dentin was prepared with 180- to 600-grit SiC paper and then uniformly irradiated with an Er: YAG laser (laser-irradiated group) or immersed in water at 60 degrees C for 15 min (heated group). The samples were then acid-conditioned with 10% citric acid (10-0) or 10% citric acid/3% ferric chloride (10-3) for 15 s and treated with GA for 10 min before bonding to an acrylic rod with 4-META/MMA-TBB resin. These samples were trimmed to prepare miniaturized dumbbell-shaped specimens. After storage in water at 37C for 1 d, the tensile bond strength was measured, and the fractured surface was evaluated using a scanning electron microscope (SEM). In the laser-irradiated and heated groups, the 10-3+GA-treated specimen had higher bond strength than that of 10-0+GA. On the other hand, the tensile bond strength of 10-3 +GA in the non-irradiated group was lower that that of 10-0+GA. In conclusion, the combination of 10-3 and GA for bonding with 4-META/MMA-TBB resin was the most effective for Er: YAG laser-irradiated dentin and heated dentin, but it was not effective for the non-irradiated dentin.

Acid Etching, Dental↗
PubMed2001

Effect of cytokines on growth and differentiation of leukaemic cells with translocation t(6;9)(p23;q34).

The translocation t(6;9)(p23;q34) is detected infrequently in subtypes of haematological malignancies including acute myelogenous leukaemia (AML) and myelodysplastic syndrome (MDS). Although the t(6;9) leukaemia is commonly associated with bone marrow basophilia, the cytological characteristics of leukaemic cells are unclear. In the current study, we examined the in vitro effects of several cytokines on growth and differentiation of t(6;9) leukaemic cells. Isolated bone marrow mononuclear cells from four patients with t(6;9) (two MDS and two AML) were cultured for 14 d in the presence or absence of each cytokine. At the end of culture, viable cells were counted, and their histology was examined. Bone marrow cells obtained from 22 patients (10 AML, six AML from MDS, six MDS) lacking t(6;9) were used as controls. Compared with control cultures, significantly higher numbers of blasts appeared in the culture of bone marrow cells from t(6;9)-positive patients in response to stimulation with granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage CSF (GM-CSF) or interleukin 3 (IL-3). Stem cell factor (SCF) had little effect. Neutrophil counts were also significantly increased in the presence of G-CSF or IL-3. SCF and IL-3 were potent in increasing basophil counts from t(6;9)-positive cultures. These findings suggest that bone marrow cells obtained from t(6;9) patients are highly sensitive to growth- and/or differentiation-promoting cytokines. Special attention should be paid to the use of "therapeutic" cytokines in these patients.

Adolescent↗
PubMed2001

Inhibition of BMP2-induced, TAK1 kinase-mediated neurite outgrowth by Smad6 and Smad7.

BACKGROUND: BMP2 is known to play a wide variety of roles, including some in the development of the nervous system. This cytokine has been reported to induce neurite outgrowth in rat pheochromocytoma PC12 cells via the activation of a p38 MAP kinase, although its regulatory mechanism remains largely to be elucidated. RESULTS: BMP2-induced neurite outgrowth in PC12 cells was inhibited by the introduction of a kinase-negative form of a MAP kinase kinase kinase, TAK1, an upstream regulatory kinase for p38 kinase. Following BMP2 stimulation, the expression of Smad6 and Smad7, inhibitory Smad species that are known to inhibit the BMP2-restricted Smad species, Smad1, Smad5 and Smad8, was up-regulated. Unexpectedly, over-expression of either Smad6 or Smad7 in PC12 cells repressed the BMP2-induced neurite outgrowth and severely impeded the p38 kinase pathway. Both of these inhibitory Smads were found to interact physically with TAK1-binding protein, a molecule required for TAK1 activation. CONCLUSIONS: This study demonstrates that BMP2-induced neurite outgrowth in PC12 cells involves activation of the TAK1-p38 kinase pathway which is inhibited by Smad6 and Smad7.

Animals↗
PubMed2001

Telemedicine system using computed tomography van of high-speed telecommunication vehicle.

The current medical system provides medical services to patients who visit hospitals. However, medical services can be provided at or close to the home of the patient using fully equipped mobile telemedicine systems. Such a system can identify the disease at an early stage, improve quality of life and prognosis through early diagnosis and treatment, and reduce the costs of medical service. Furthermore, the unit can provide mass screenings of the population, as well as full medical service to remote areas. The Telecommunications Advanced Organization of Japan, Matsumoto, Japan, and Shinshu University Hospital, Matsumoto, Japan, established a research center for a unique telemedicine project using a mobile system. The mobile unit consists of a van that houses a spiral computed-tomography (CT) machine and various telecommunications equipment. The unit allows medical examination, CT scanning, and on-line two-way transfer of image data/teleconferencing to a medical center for consultation with various specialists. We have used the system thus far for the early detection of lung cancer through mass screenings over a four-year period in 29 administrative districts. Mass screenings of 19117 residents resulted in the identification of 75 cases of early lung cancer who were later treated by partial pneumonectomy at Shinshu University Hospital and affiliated hospitals. We have also used the system to provide medical services to rural areas, as telemedicine support at remote areas, wintertime telemedicine support to an international sports competition, and various medical services to a home-care facility.

Humans↗