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T Shibata

Publications and source records attributed to T Shibata.

At least 163 records · Page 9Linked to original sources
PubMed2000

Discrimination among three species of medicinal Scutellaria plants using RAPD markers.

An analysis of random amplified polymorphic DNA (RAPD) was performed using nine accessions of three species of medicinal plants in the genus Scutellaria (S. galericulata, S. lateriflora and S. baicalensis; known collectively as skullcap) in an effort to distinguish between members of these three species. Dried aerial parts of the two species S. galericulata and S. lateriflora are difficult to distinguish morphologically. Ten arbitrary primers produced 92 fragments, and eight of the primers yielded 23 species-specific fragments among the three species. Six fragments were specific for S. galericulata, seven for S. lateriflora and ten for S. baicalensis. When primers A02 and A06 were used in the polymerase chain reaction, RAPD fragments that were specific for each of the three species were generated simultaneously. Primer A02 produced five species-specific fragments: one was specific for S. galericulata; two for S. lateriflora; and two for S. baicalensis. Primer A06 produced three species-specific fragments: one for S. galericulata; one for S. lateriflora; and one for S. baicalensis. The RAPD markers that were generated with these two primers should rapidly identify members of the three species of Scutellaria. The consistency of the identifications made with these species-specific RAPD markers was demonstrated by the observation that each respective marker was generated from three accessions of each species, all with different origins. Furthermore, cluster analysis using the 92 RAPD fragments produced a dendrogram of genetic relatedness that was in good agreement with the taxonomic designations of the three species. Thus, the RAPD markers should be useful for the future identification of members of the three species of medicinal Scutellaria plants.

Plants, Medicinal↗
PubMed2000

Neointimal formation at the sites of anastomosis of the internal thoracic artery grafts after coronary artery bypass grafting in human subjects: an immunohistochemical analysis.

OBJECTIVES: The aim of this study was to evaluate the cellular composition and cell proliferative activity of neointimal tissue in human internal thoracic artery grafts and to characterize the differentiation state of neointimal smooth muscle cells at early stages after coronary artery bypass grafting. METHODS: The anastomotic sites and body segments of 7 patent grafts were obtained at autopsy from 7 patients who died within 92 days after operation. Serial sections were examined by immunohistochemical techniques to identify macrophages, endothelial cells, smooth muscle cell phenotype, and proliferating cells. For the identification of the cell types that show cell proliferative activity, immunodouble staining was also performed. RESULTS: In all body segments the luminal surface was completely covered by endothelial cells, and no areas showed thrombus formation or neointimal proliferation after grafting. In contrast, in the anastomotic segments endothelial denudation and focal disruption of the internal elastic lamina with adherence of fibrin-platelet thrombus and infiltration of macrophages were observed in the earliest stage after grafting. At these sites of injury, early neointimal tissue response had occurred, and cell proliferative activity was detected in macrophages and dedifferentiated smooth muscle cells. During the evolution of neointimal thickening, redifferentiation of neointimal smooth muscle cells occurred associated with the decline in proliferative activity. CONCLUSIONS: These observations strongly support the concept that excessive neointimal proliferation, which may occur at the site of anastomosis because of extensive damage to the arterial wall, could be one of the possible causes of failure of the internal thoracic artery graft in human beings.

Aged↗
PubMed2000

Identification of ribonucleotide reductase protein R1 as an activator of microtubule nucleation in Xenopus egg mitotic extracts.

Microtubule nucleation on the centrosome and the fungal equivalent, the spindle pole body (SPB), is activated at the onset of mitosis. We previously reported that mitotic extracts prepared from Xenopus unfertilized eggs convert the interphase SPB of fission yeast into a competent state for microtubule nucleation. In this study, we have purified an 85-kDa SPB activator from the extracts and identified it as the ribonucleotide reductase large subunit R1. We further confirmed that recombinant mouse R1 protein was also effective for SPB activation. On the other hand, another essential subunit of ribonucleotide reductase, R2 protein, was not required for SPB activation. SPB activation by R1 protein was suppressed in the presence of anti-R1 antibodies or a partial oligopeptide of R1; the oligopeptide also inhibited aster formation on Xenopus sperm centrosomes. In accordance, R1 was detected in animal centrosomes by immunofluorescence and immunoblotting with anti-R1 antibodies. In addition, recombinant mouse R1 protein bound to gamma- and alpha/beta-tubulin in vitro. These results suggest that R1 is a bifunctional protein that acts on both ribonucleotide reduction and centrosome/SPB activation.

Amino Acid Sequence↗
PubMed2000

Identification of Thermus thermophilus HB8 tRNA (Gm18) methyltransferase gene.

For the purpose of identification of the gene for Thermus thermophilus tRNA (Gm18) methyltransferase [tRNA (guanosine-2'-)-methyltransferase, EC 2.1.1.34], the purified enzyme from native source was analyzed by the peptide-mass mapping. The target gene encoded the amino acid sequences of the obtained peptides was searched in data from Thermus thermophilus HB8 genome-sequencing project. We found the target gene AB05130, which was expected to encode a protein composed of 194 amino acid residues and the molecular mass of this protein was calculated as 22083. The recombinant protein was expressed in E. coli as an active form. The Gm18 formation activity of the purified recombinant protein was confirmed by in vitro methylation followed by two-dimensional thin layer chromatography and Liquid Chromatography/Mass Spectrum analysis of substrate tRNA.

Base Sequence↗
PubMed2000

RecA-double stranded DNA complexes studied by atomic force microscopy.

RecA-double stranded (ds) DNA complexes have been studied by atomic force microscopy (AFM). When the complexes were prepared in the presence of ATP gamma S, fully covered RecA-dsDNA filaments were observed by AFM. When the concentration of RecA proteins was lower, various lengths of filaments were found. The variation of the observed structures may directly reflect the real distribution of the intermediate complexes in the reaction mixture, as the mixture was simply deposited on a mica surface for AFM observation without special fixation or staining. The use of a carbon nanotube (CNT) AFM tip enabled high resolution to reveal the periodicity of RecA-dsDNA filaments. Our observations demonstrated the potential of the AFM method for the structural studies of the RecA-dsDNA complexes, especially their intermediate states.

Adenosine Triphosphate↗
PubMed2000

Gradual tilting of crystallographic orientation and configuration of dislocations in GaN selectively grown by vapour phase epitaxy methods

Cross-sectional transmission electron microscope (TEM) observation was performed for selectively grown gallium nitride (GaN) in order to examine the dependence of GaN microstructure on the growth conditions. The GaN films were grown by hydride vapour phase epitaxy (HVPE) or metalorganic vapour phase epitaxy (MOVPE) on GaN covered with a patterned mask. Thin foil specimens for TEM observation were prepared with focused ion beam (FIB) machining apparatus. It was demonstrated that the c-axis of GaN grown over the terrace of the mask tilts towards the centre of the terrace when the GaN is grown in a carrier gas of N2. The wider terrace results in a larger tilting angle if other growth conditions are identical. The tilting is attributed to 'horizontal dislocations' (HDs) generated during the overgrowth of GaN on the mask terrace. The HDs in HVPE-GaN have a semi-loop shape and are tangled with one another, while those in MOVPE-GaN are straight and lined up to form low-angle grain boundaries.

Journal Article↗
PubMed2000

Characterization of monoclonal antibodies generated against Norwalk virus GII capsid protein expressed in Escherichia coli.

The Norwalk virus (NV) causes outbreaks of acute non-bacterial gastroenteritis in humans. The virus capsid is composed of a single 60 kDa protein. The capsid protein of NV36 (genogroup II, Mexico virus type) was expressed in an Escherichia coli system and ten monoclonal antibodies (MAbs) were generated against it. The reactivity of these MAbs was characterized using enzyme-linked immunosorbent assay (ELISA) and Western blot (WB) analysis towards 20 overlapping fragments of the NV36 capsid protein expressed in E. coli. All of the MAbs recognized sequential (continuous) epitopes on the three antigenic regions. Six of the 10 MAbs recognized fragment 2 (equivalent residues 31-70), three MAbs recognized fragment 13 (residues 361-403) and one MAb recognized fragment 7 (residues 181-220), suggesting that the N-terminal domain (residues 1-220) may contain more antigenic epitopes than the C-terminal domain (residues 210-548). Furthermore, two MAbs (1B4 and 1F6) reacted in WB with three purified NV strains (genogroup II) derived from patients' stool samples. It was also found that genogroup I recombinant NV96-908 (genogroup I, KY89 type) could be detected as sensitively as recombinant NV36 (genogroup II) by ELISA with a set of the MAbs produced here.

Amino Acid Sequence↗
PubMed2000

Phenotypic change of muscularis mucosae in early invasive colorectal adenocarcinoma.

BACKGROUND: Invasive colorectal adenocarcinomas have bundles of eosinophilic spindle cells, which are regarded as myofibroblasts, in their desmoplastic stroma, some of which are continuous with the muscularis mucosa. AIM: To investigate the relation between the eosinophilic spindle cells and the muscularis mucosa based on their cytoskeletal phenotypes in early invasive colorectal adenocarcinoma. METHODS: Formalin fixed, paraffin wax embedded tissues of 17 early invasive colorectal adenocarcinomas were immunostained for alpha-smooth muscle actin (alpha-SMA), desmin, and vimentin. RESULTS: The phenotype of the muscularis mucosa was alpha-SMA positive, desmin positive, and vimentin weakly positive, whereas the eosinophilic spindle cells showed a decreased degree of immunoreactivity for alpha-SMA and desmin in particular, and an increased degree of immunoreactivity for vimentin. The degree of phenotypic difference between the muscularis mucosa and the eosinophilic spindle cells was greater in the eosinophilic spindle cells in the centre of the invasive area that were not continuous with the muscularis mucosa than in the eosinophilic spindle cells continuous with the muscularis mucosa. CONCLUSIONS: These findings suggest that the smooth muscle cells of the muscularis mucosa change their phenotype to become eosinophilic spindle cells, namely myofibroblasts, in the early invasive area of colorectal adenocarcinoma.

Actins↗
PubMed2000

Regulation of insulin-like growth factor-binding protein-1 by nitric oxide under hypoxic conditions.

Nitric oxide (NO) is believed to play an important, but as yet undefined, role in regulating hypoxia inducible gene expression. Recently, we have reported evidence suggesting that the human insulin-like growth factor-binding protein-1 (IGFBP-1) gene is directly regulated by hypoxia through the hypoxia-inducible factor-1 pathway. The goal of the current study was to investigate NO regulation of hypoxic induction of IGFBP-1 gene expression using HepG2 cells, a model system of hepatic gene expression. We report that a NO generator, sodium nitroprusside, significantly diminishes hypoxic activation of IGFBP-1 protein and messenger ribonucleic acid expression. Furthermore, these effects are independent of guanylate cyclase/ cGMP signaling, as two different inhibitors, LY 83583, a specific inhibitor of guanylate cyclase, and KT 5823, a protein kinase G inhibitor, had no effect on IGFBP-1 induction by hypoxia. Hypoxic induction of a reporter gene containing four tandemly ligated hypoxia response elements was completely blocked by sodium nitroprusside, but not by 8-bromo-cGMP, an analog ofcGMP. These results suggest that NO blocks hypoxic induction of IGFBP-1 by a guanylate cyclase/ cGMP-independent pathway, possibly at the level of oxygen sensing. The impaired hypoxia regulation of IGFBP-1 by nitric oxide may play a key role in the hyperinduction of IGFBP-1 observed in pathophysiological conditions such as fetal hypoxia and preeclampsia where dysregulation of NO has been observed.

Alkaloids↗
PubMed2000

A clinical study on velocity patterns of pulmonary venous flow in canine heartworm disease.

In this study, we evaluated methods of determining the velocity patterns of pulmonary venous flow (PVF) in dogs and then investigated the relationship of the patterns to cardiac functions in heartworm disease (HD) by transthoracic echocardiography (TTE). The results revealed that there was a good correlation between PVF patterns determined by transesophageal echocardiography (TEE) and TTE in animals lying on their left sides. The measurement of S and D wave velocities (PVS and PVD) by TTE was shown to allow clinical determination of the velocity patterns of PVF in dogs. The HD groups showed significant increases in PVS and PVD, and S and D wave time-velocity integrals (S-TVI and D-TVI) of the right cranial lobe PVF, when compared with the normal group, as determined by TTE (P<0.05). In contrast, the HD groups produced significant decreases in PVD and D-TVI of the right caudal lobe PVF compared with the normal group (P<0.05), and a significant increase in the ratio of S-TVI to (S-TVI + D-TVI) (P<0.05). It is, therefore, suggested that measurement of the velocity patterns of the right cranial and caudal lobe PVF could be one method of assessing the stages of obstructive lesions in the pulmonary artery.

Animals↗
PubMed2000

Flash-related synchronization and desynchronization revealed by a multiple band frequency analysis.

The fast Fourier transform (FFT) is a good method to estimate power spectral density (PSD), but the frequency resolution is limited to the sampling window, and thus the precise characteristics of PSD for short signals are not clear. To relax the limitation, a multiple band-pass filter was introduced to estimate the precise course of PSDs for flash visual evoked potentials (VEPs). Signals were recorded during -200 and 600 ms using balanced noncephalic electrodes, and sampled at 1,000 Hz in 12 bits. With 1 Hz and 10 ms resolutions, PSDs were estimated between 10 and 100 Hz. Background powers at the alpha- and beta-bands were high over the posterior scalp, and powers around 200 ms were evoked at the same bands over the same region, corresponding to P110 and N165 of VEPs. Normalized PSDs showed evoked powers around 200 ms and suppressed powers following the evoked powers over the posterior scalp. The evoked powers above the 20 Hz band were not statistically significant, however, the gamma band was significantly evoked intra-individually; details in the gamma bands were varied among the subjects. Details of PSDs were complicated even for a simple task such as watching flashes; both synchronization and desynchronization occurred with different distributions and different time courses.

Adult↗
PubMed2000

Percutaneous ethanol injection for treatment of adrenal metastasis from hepatocellular carcinoma.

OBJECTIVE: With the improved prognosis of patients with hepatocellular carcinoma, the likelihood of diagnosing adrenal metastasis has increased. We performed percutaneous ethanol injection for adrenal metastasis in seven patients and evaluated its efficacy. CONCLUSION: Percutaneous ethanol injection was successfully performed in nine nodules in seven patients. During follow-up, six nodules in five patients showed no increase in size. Four patients were alive 6-28 months after injection, one patient died of hepatic failure, one of brain metastasis, and one of multiple metastases. Percutaneous ethanol injection can be an alternative treatment for adrenal metastasis of hepatocellular carcinoma.

Adrenal Gland Neoplasms↗
PubMed2000

[A case of tricuspid infective endocarditis in a drug addict].

This report describes a successful operative case of tricuspid infective endocarditis in a drug addict. A 24-year-old man with a history of drug addiction (6 months) complained of general fatigue and high fever. Echocardiography showed a large vegetation attached to the tricuspid valve and severe tricuspid regurgitation. Blood cultures revealed septicemia due to methicillin sensitive Staphylococcus aureus. He was treated for about 1 week with intravenous antibiotics. However, subsequent severe heart failure necessitated emergency operation. The tricuspid valve was replaced with Carpentier-Edwards bioprosthesis because of severe destruction of the tricuspid valve. The postoperative course was uneventful and he has remained free from endocarditis for 15 months after surgery.

Adult↗
PubMed2000

[Successful aortic root replacement for prosthetic valve endocarditis using the freestyle stentless bioprosthesis: report of two cases].

We report two cases of prosthetic valve endocarditis which were successfully treated with aortic root replacement using the freestyle stentless bioprosthesis. Prosthetic valve endocarditis occurred in two patients after aortic valve replacement and modified Bentall operation, respectively. The aortic annulus was severely damaged and left ventriculo-aortic discontinuity was found in both cases. We used the freestyle stentless bioprosthesis, which fits well to the destroyed aortic annulus with left ventriculo-aortic discontinuity, because of its flexibility. Postoperative echocardiography revealed excellent hemodynamic results in both cases. Although the long-term results obtained with the freestyle stentless bioprosthesis, such as resistance to bacterial infection, have not been reported, this prosthesis appears to be very useful for treatment of prosthetic valve endocarditis. We expect that this prosthesis might be a option for PVE as an alternative to a homograft.

Adult↗
PubMed2000

[Assessment of colorectal cancer patients exhibiting bilobular multiple hepatic metastases].

We assessed 23 patients who underwent surgical therapy of hepatectomy or microwave coagulation therapy (MCT) for bilobular multiple hepatic metastatic foci following curative resection of the primary lesion of colorectal cancer. Hepatectomy was the first surgical therapy for 10 patients, and 6 of them received combined intra-arterial chemotherapy. All 13 patients in the MCT group received intra-arterial chemotherapy, and 8 of them underwent combined hepatectomy. The two-year survival rate of the hepatectomy group, classified according to the first surgical therapy, was 40% against 52% in the MCT group. In comparison with the H2 (2-5 foci) patients in the hepatectomy group, there were 7 H2 patients in the MCT group, and the two-year survival rate of these 7 patients was 50%. No significant difference was observed between hepatectomy and the MCT as the first surgical therapy. The survival rates of the 5 patients who received treatment for recurrence after the first surgery and of the 18 patients without any recurrence treatment were 80% and 40%, respectively. No significant difference existed between the two groups, but a p value of 0.06 was noted. MCT was considered to be useful local therapy for cancer as the first therapy and as a therapy following recurrence.

Antineoplastic Agents↗
PubMed2000

[A case report of intra-thoracic biliary fistula after percutaneous microwave coagulation therapy].

Among the locoregional therapies for hepatic malignant tumor, percutaneous microwave coagulation therapy (PMCT) has spread widely as a minimally invasive therapy. We performed PMCT on 40 patients under hepatic blood flow interruption with the aim of improving the radical treatment and expanding the coagulation area by single microwave delivery. A patient with a 2.5 cm lesion in S5 of the liver under PMCT transdiaphragmatically, but he developed a postoperative biliary fistula with consequent development of an intra-thoracic abscess through the diaphragm. Biliary fisture and liver abscess disappeared with open drainage under thoracotomy and laparotomy. Liver abscess has occasionally been reported as a PMCT complication, whereas there have been no reports, to the authors' knowledge, about intra-thoracic abscess as a PMCT complication, as in our case. It should be kept in mind that the penetration of the diaphragm as a route for PMCT may result in a biliary fistula flowing into the thorax, leading to a very serious condition.

Abscess↗
PubMed2000

[Transcatheter arterial chemo-embolization using degradable starch microspheres (DSM) markedly effective for post-hepatectomy intra-hepatic recurrence in a patient with cholangioma].

Transcatheter arterial chemo-embolization (TACE) using degradable starch microspheres (DSM) was performed for multiple recurrence after hepatectomy in a patient with cholangiocarcinoma. The patient was a 68-year-man. He received treatment for hepatitis type C starting in 1996 at a nearby hospital. In November 1997, an increased AFP level was noted and a CT scan of the abdomen revealed an abnormal shadow in the liver. On May 21, 1998, imaging results led to the diagnosis of cholangiocarcinoma or a mixed type of hepatocellular carcinoma with cholangioma. Hepatic S7 sub-sequential resection was performed. The lesion was found to be a tumor-forming type, measuring 2.2 x 2.0 cm in diameter, diagnosed histopathologically as cholangiocarcinoma, tw (-), but Stage III since a nodule suggesting intrahepatic metastasis was noted in the cut surface of the resected liver. CT scan after a month revealed multiple metastatic lesions in the liver. TACE was performed by administering 450 mg of DSM, 10 mg of MMC and 30 mg of FARM, given in three divided doses on October 30, 1998, and February 9, 1999, according to Seldinger's method. A CT scan on January 31, 2000 revealed nearly complete remission of the hepatic SOL. Accordingly, TACE was considered to be useful therapy in combination with DSM, MMC and FARM for intrahepatic recurrence of cholangiocarcinoma.

Aged↗