Search PubMed⌕ Search

Biomedical subjects

T Yagi

Publications and source records attributed to T Yagi.

At least 19 recordsLinked to original sources
PubMed2006

Perfect softening of the ferroelectric mode in the isotope-exchanged strontium titanate of SrTi18O3 studied by light scattering.

The mode of the isotope-induced ferroelectric strontium titanate shows a perfect softening at the ferroelectric phase transition temperature , where the frequency of the underdamped mode approaches completely to zero within the instrumental resolution. The spectra of the Raman inactive soft mode have been successfully observed owing to local symmetry breaking and by long-term accumulation of the spectral intensity with a high resolution technique. The mechanism of the phase transition is concluded to be an ideal displacive-type accompanied with perfect softening of the Slater-type polar mode. The difference between the soft mode behavior of and indicates that the origin of the quantum paraelectric state of lies in the quantum fluctuation of the oxide octahedron in the perovskite structure.

Journal Article↗
PubMed2005

[Surgical treatment of lung cancer in octagenarian patient].

Because average life span of Japanese is getting longer, we sometimes meet elder lung cancer patients of over 80. They often have many complications, so we are worried about how to treat them. Recently we met 8 elder patients with lung cancer, and we performed surgical operation for them. Six patients performed partial lung resection or lobectomy had no complications after operation. But 2 patients with respiratory disorder who performed lobectomy and chest wall resection had some complications after operation. In such patients, careful postoperative management is needed, and continuous positive airway pressure (CPAP) ventilation with pressure support (PS) may be useful to prevent respiratory complications.

Age Factors↗
PubMed2004

Vitamin B6 compounds prevent the death of yeast cells due to menadione, a reactive oxygen generator.

The antioxidant effects of natural vitamin B(6) compounds on Schizosaccharomyces pombe cells treated with menadione sodium bisulfite (water-soluble menadione and a generator of superoxide, MSB) and the mechanism underlying the function were examined with the yeast cells treated with pyridoxal 5'-phosphate. Vitamin B(6) compounds showed no ex vivo reactivity toward MBS at pH 5.5 or 7.0. The yeast cells showed no growth in the medium containing 1.0 mM MSB. The coexistence of 1.0 mM of each vitamin B(6) compound supported the growth of the yeast cells. The efficacy order was pyridoxal 5'-phosphate>/=pyridoxamine 5'-phosphate>pyridoxamine>pyridoxal>/=pyridoxine. The first three compounds showed higher antioxidant activity than vitamin C did. Pyridoxal 5'-phosphate prevented the reduction of the glutathione content in the MSB-treated cells and, in turn, suppressed the increases in peroxide and thiobarbituric acid reactive substances in the yeast cells and increased the viability of the yeast cells under oxidative stress. The antioxidant function of pyridoxal 5'-phosphate was not dependent on the phosphorelay pathway, which finally triggers the expression of the catalase gene.

Antifibrinolytic Agents↗
PubMed2004

Comparison of left atrial size by freehand scanning three-dimensional echocardiography and two-dimensional echocardiography.

AIMS: As the left ventricular (LV) dimension is a poor indicator of LV volume, there are well-known limitations of left atrial (LA) antero-posterior dimensions as indicators of chamber size. LA volume has been shown to provide a more accurate assessment of LA size than LA dimension. To evaluate two-dimensional (2D)-derived LA volume in assessing LA size, we compared LA dimension and 2D LA volume with three-dimensional (3D)-derived LA volume. METHODS: We performed transthoracic freehand scanning 3D echocardiography (3D EchoTech, Germany) using magnetic fields and a harmonic imaging system in 32 patients. We collected a series of LA tomograms by slowly tilting the probe (fan-like scanning) in the parasternal position. The 3D LA volume was calculated by using the multiplanar Simpson's method. The 2D LA volume was measured by using the modified biplane Simpson's rule. RESULTS: LA antero-posterior dimensions and 2D volumes showed a significant positive correlation with 3D LA volumes. However, the correlation coefficient was significantly greater for the relationship between 2D LA volumes and 3D LA volumes than for that between LA dimensions and 3D LA volume. CONCLUSIONS: The 2D LA volumes provide a more accurate measure of the true size of the LA and are more sensitive to changes in LA size.

Adult↗
PubMed2004

Induction of eotaxin production by interleukin-4, interleukin-13 and lipopolysaccharide by nasal fibroblasts.

BACKGROUND: There is growing evidence that eotaxin is a key mediator in the development of tissue eosinophilia. Fibroblasts are a major source of eotaxin. The severity of diseases with eosinophilic inflammation like nasal polyposis, atopic dermatitis and asthma, where Th2-type cytokines (IL-4 and IL-13) and TGF-beta are expressed locally, was shown to correlate with bacterial factors such as lipopolysaccharide (LPS) rather than allergen. OBJECTIVE: We examined eotaxin production by nasal fibroblasts stimulated with IL-4 or IL-13 alone or in combination with LPS, and the effect of TGF-beta(1) on it. Moreover, we compared the magnitude of eotaxin produced by nasal fibroblasts with that produced by lung or skin fibroblasts. METHODS: Fibroblast lines were established from human biopsy tissue. The expression of eotaxin mRNA was evaluated by RT-PCR. The amount of eotaxin in the supernatants was measured by ELISA. RESULTS: IL-4, but not IL-13, synergized with LPS to produce eotaxin in a dose- and time-dependent manner. Sequential treatment of nasal fibroblasts with IL-4 and LPS did not have any effect. But when IL-4 and LPS were added together, synergy for eotaxin production was observed. Moreover, this synergy was observed in nasal and skin fibroblasts, but not in lung fibroblasts. The production of eotaxin by IL-4 and LPS was modulated by TGF-beta(1). CONCLUSION: These results suggest that a co-stimulus like LPS is necessary for IL-4 to make a strong induction of eotaxin in eosinophilic inflammations such as nasal polyposis. Modulation by TGF-beta(1) may have important implications for the development of eosinophilic inflammation.

Cell Line↗
PubMed2004

[Negative pleural cytology after intrapleural perfusion hyperthermo-chemotherapy for malignant pleural effusion].

We gave intrapleural perfusion hyperthermo-chemotherapy to a 72-year-old woman in whom malignant pleural effusion developed after surgery for primary cancer. This procedure involved irrigating the pleural space for 2 hours with a water solution at 42-43 degrees containing 240 mg cisplatin using specially devised extracorporeal circuits. Thoracoscopy was used to examine the intrapleural cavity and to place the catheters for perfusion. The patient had an uneventful postoperative course and was discharged for hospital on the second postoperative day. Thereafter, she experienced good quality of life with negative pleural cytology. Unfortunately, the patient died 3 months after the therapy, but the cause of death was unknown and there was no cancer recurrence. This technique may be safe and feasible for controlling malignant effusion to preserve quality of life, although the survival benefit has not yet been clarified.

Aged↗
PubMed2003

Survey of Vibrio cholerae O1 and its survival over the winter in marine water of Port of Osaka.

The survey of Vibrio cholerae O1 in marine area was carried out in the Port of Osaka, Japan in 1987-2001, and 51 V. cholerae O1 strains were isolated. All strains were identified to be of El Tor biotype, Ogawa serotype and classic Ubon Kappa-phage type, and were cholera toxin (CT)-negative and CT gene-negative. In order to clarify certain ecological aspects of V. cholerae O1 in the marine environment of the temperate zone, we performed molecular analysis of the isolated strains using pulsed-field gel electrophoresis (PFGE) with NotI and SfiI restriction enzymes. We found the indistinguishable strains by DNA analysis using PFGE with strains passed for 1 year, and also found the closely related strains with that passed for 3 and 12 years. Those results indicated that V. cholerae O1 can survive over one winter at least, and that it survives in marine water for a long time by undergoing continuous mutation.

Adaptation, Physiological↗
PubMed2003

Esophageal actinomycosis after allogeneic peripheral blood stem cell transplantation for extranodal natural killer/T cell lymphoma, nasal type.

We report a 19-year-old man with extranodal natural killer (NK)/T cell lymphoma, nasal type treated by allogeneic peripheral blood stem cell transplantation (allo-PBSCT). His lymphoma was chemoresistant, and disseminated during local radiotherapy. The patient received allo-PBSCT from his HLA-1 locus mismatched sister using busulfan (BU), cyclophosphamide (CY) and VP-16 as the conditioning regimen. His course was complicated by esophageal actinomycosis 9 months after transplantation, which resulted in the rupture of the right common carotid artery. These observations suggest that actinomycosis should be monitored carefully after transplantation in patients who have received local radiation therapy before the procedure.

Actinomycosis↗
PubMed2003

Attenuation of ganglioside GM1 accumulation in the brain of GM1 gangliosidosis mice by neonatal intravenous gene transfer.

A single intravenous injection with 4 x 10(7) PFU of recombinant adenovirus encoding mouse beta-galactosidase cDNA to newborn mice provided widespread increases of beta-galactosidase activity, and attenuated the development of the disease including the brain at least for 60 days. The beta-galactosidase activity showed 2-4 times as high a normal activity in the liver and lung, and 50 times in the heart. In the brain, while the activity was only 10-20% of normal, the efficacy of the treatment was distinct. At the 30th day after the injection, significant attenuation of ganglioside GM1 accumulation in the cerebrum was shown in three out of seven mice. At the 60th day after the injection, the amount of ganglioside GM1 was above the normal range in all treated mice, which was speculated to be the result of reaccumulation. However, the values were still definitely lower in most of the treated mice than those in untreated mice. In the histopathological study, X-gal-positive cells, which showed the expression of exogenous beta-galactosidase gene, were observed in the brain. It is noteworthy that neonatal administration via blood vessels provided access to the central nervous system because of the incompletely formed blood-brain barrier.

Adenoviridae↗
PubMed2003

3D eye movement analysis during sinusoidal off vertical axis rotation in human subjects.

OBJECTIVE: It has been reported that the eye movements induced by off vertical axis rotation (OVAR) are composed of two components: a bias component (BIC) and a modulation component (MOC). It was suggested that the MOC compensates for changes in head orientation with respect to gravity and that the BIC is related to the velocity storage mechanism. However, the characteristics of the otolith organs remain obscure. In order to investigate these characteristics, we performed a 3D analysis of eye movements induced by human sinusoidal s-OVAR, and compared the result with that of eye movements induced by constant c-OVAR. MATERIAL AND METHODS: Fifteen healthy human subjects participated in this study. OVAR stimulation was produced by rotation following tilt. After a 30 degrees tilt, the subject was rotated sinusoidally at 0.05 and 0.02 Hz at 50 degrees/s peak velocity. Eye movements were recorded using an infrared charge-coupled device camera, and the updated version of our standard computerized image recognition method was used to analyze them three-dimensionally. RESULTS: The eye movements induced by s-OVAR consisted of two kinds of sine waves: low- and high-frequency components. The low-frequency component was related to the change in angular acceleration, and the eye movements were found to derive from the semicircular canals. In contrast, the high-frequency component was related to the change in head position, and the eye movements were found to derive from the otolith organs. CONCLUSION: s-OVAR may prove to be a useful tool for simultaneously assessing the functions of both the otolith organs and the semicircular canals.

Adult↗
PubMed2003

Cadherin-related neuronal receptors in incisor development.

Cadherins are cell adhesion molecules that are critical for tissue development. In this report, we identified members of the cadherin family cadherin-related neuronal receptors (CNRs) 1 and 5 expressed in rat incisors by the differential display method. Quantitative RT-PCR revealed that CNR1 mRNA is expressed in the secretory stage but reduced in the early-maturation stage, while CNR5 mRNA is expressed in both these stages. In situ hybridization showed that strong expression of CNR1 is strong in the secretory stage, but reduced in the early phase and diminished in the late phase of the early-maturation stage. CNR5 mRNA is expressed almost at the same levels in the secretory and in the early phase of the early-maturation stages but is absent in the late phase of the early-maturation stage. Both CNR1 and 5 mRNA are continuously expressed in odontoblasts. Immunohistology showed that CNR proteins are expressed in the secretory and early-maturation stages of ameloblasts, but no protein expression at the late-maturation stage was observed. CNR proteins were continuously expressed in odontoblasts. We found that recombinant CNR1 binds dental epithelial and mesenchymal cells through N-terminal domain EC1 in vitro. These results suggest that CNR1 and CNR5 may play an important role in enamel and dentin formation, probably through cell-cell and/or cell-matrix interactions.

Ameloblasts↗
PubMed2003

Adjustment of the occlusal vertical dimension in the bite-raised guinea pig.

In humans, the inappropriate occlusal vertical dimension (OVD) causes several orofacial disorders, such as bruxism and pain in the masticatory muscles and temporomandibular joint. However, it is still unclear how strictly the OVD is adjusted. To answer this question, we studied the temporal change of the OVD in bite-raised young guinea pigs. The OVD was raised by fixation of a bite-raising appliance to the lower incisors, and increased by either 3 or 1.5 mm at the first molars. After the space produced between the upper and lower molars was filled within 10 days due to eruption of the molars, the appliance was removed. In the bite-raised animals, the raised OVD was reduced until it attained that observed in the control animals, after which the OVD increased according to cranial growth. These results show that the OVD is developmentally changed and strictly controlled.

Adaptation, Physiological↗
PubMed2003

An involvement of trigeminal mesencephalic neurons in regulation of occlusal vertical dimension in the guinea pig.

Although the occlusal vertical dimension (OVD) is strictly controlled, the neuronal mechanism of its regulation is still unclear. We hypothesize that neurons in the trigeminal mesencephalic nucleus (MesV) play an important role in the regulation of the OVD, because the MesV receives the projection from jaw-closing muscle spindles and periodontal mechanoreceptors. We measured the temporal OVD change in the guinea pig to study the effects of MesV lesions on the OVD. OVD-raised animals without MesV lesions showed a rapid OVD decrease to the same level as that in naïve controls, followed by an OVD increase after the OVD-raising appliance was removed. In contrast, OVD-raised animals with MesV lesions showed only a slight decrease in the OVD for 15 days after removal of the appliance, and then the OVD increased. The time-course of OVD development in normal-bite animals with MesV lesions was similar to that of naïve controls. These results suggest that MesV neurons are involved in OVD regulation.

Animals↗
PubMed2002

The analysis of the usefulness of laparoscopic microwave coagulation therapy for hepatocellular carcinoma in patients with poor hepatic reserve by serial measurements of IL-6, cytokine antagonists, and C-reactive protein.

BACKGROUND: Little is known about the effectiveness of laparoscopic microwave coagulation therapy (L-MCT) for hepatocellular carcinoma (HCC) in patients with liver cirrhosis and poor hepatic reserve. Here, we analyzed the usefulness of laparoscopic MCT by comparing the serum levels of IL-6, cytokine antagonists, and C-reactive protein (CRP) following L-MCT with those following MCT with the open method (O-MCT). METHODS: Sixteen patients with hepatocellular carcinoma (HCC) were separated into L-MCT and O-MCT groups according to ICGR15 (ICGR15 30%<:L-MCT, 30%> :O-MCT). Nine patients with poorer hepatic reserve received L-MCT, while seven patients with relatively good hepatic reserve received O-MCT. Serum levels of cytokine antagonists (interleukin-6, IL-6; interleukin-1 receptor antagonist, IL-1ra; soluble tumor necrosis factor receptor type I, sTNF-R55) and C-reactive protein (CRP) were simultaneously measured on serial postoperative days (POD) by immunoassay. RESULTS: Postoperative serum levels of IL-6, IL-1ra, and CRP were significantly elevated on POD-1 and returned to the preoperative levels on POD-7 in both L-MCT and O-MCT groups. In contrast, no significant elevation of sTNF-R55 was found during the period in both groups. In addition, no statistical differences were found in the levels of IL-6, IL-1ra, sTNF-R, and CRP between the groups, except that the level of IL-6 on POD-1 in L-MCT group was significantly lower than that in the O-MCT group. CONCLUSION: These results suggested that the surgical stress by L-MCT in patients with poorer hepatic reserve were almost equal to that by O-MCT in patients with relatively good hepatic reserve, indicating the usefulness of L-MCT for HCC patients with poorer hepatic reserve. We recommend the laparoscopic approach for future patients with the criterion that ICGR15 is over 30%.

C-Reactive Protein↗
PubMed2002

A novel infant acute lymphoblastic leukemia cell line with MLL-AF5q31 fusion transcript.

Infant acute lymphoblastic leukemia (ALL) is characterized by the presence of the proB phenotype (CD10(-)/CD19(+)), poor prognosis and frequent rearrangement of the mixed lineage leukemia (MLL) gene. The most frequent rearrangement is t(4;11)(q21;q23), the role of whose product, the MLL-AF4 fusion transcript, has been extensively studied in leukemogenesis. In a cell line of infant leukemia with MLL rearrangement denoted KP-L-RY, panhandle PCR amplification of cDNA revealed the presence of a fusion transcript, MLL-AF5q31, indicating that AF5q31 is also a partner gene of MLL. In this fusion transcript the MLL exon 6 is fused in frame to the 5' side of the putative transactivation domain of AF5q31. The AF5q31 protein is a member of the AF4/LAF4/FMR2-related family of proteins, which have been suggested to play a role in hematopoietic cell growth and differentiation. The MLL-AF5q31 fusion transcript, although probably rare, appears to be associated with the pathogenesis of infant ALL like MLL-AF4. Co-expression of HoxA9 and Meis1 genes in the KP-L-RY cell line indicated possible functional similarity between MLL-AF4 and MLL-AF5q31. Further understanding of the function of AF5q31 as well as the specific leukemogenic mechanism of MLL-AF5q31 awaits future studies.

Acute Disease↗
PubMed2002

Adult murine neurons: their chromatin and chromosome changes and failure to support embryonic development as revealed by nuclear transfer.

Fully differentiated neurons in adult mammalian brains do not divide; consequently, their metaphase chromosomes have never been examined. Here we report metaphase chromosome constitutions of cortical neurons in adult mice visualized by a nuclear transfer technique. We found that although some reconstructed oocytes cloned from neuronal nuclei have an apparently normal karyotype, the majority do not. Regardless of chromosome morphology, nuclei of adult neurons totally lack the ability to support embryonic development. These findings support the hypothesis that fully differentiated neurons in adult mammalian brains are genomically altered.

Animals↗