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Search Results: 1 - 10 of 889 matches for " Toshio Uraoka "
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What are the latest developments in colorectal endoscopic submucosal dissection?
Toshio Uraoka,Yutaka Saito,Naohisa Yahagi
World Journal of Gastrointestinal Endoscopy , 2012, DOI: 10.4253/wjge.v4.i7.296
Abstract: Endoscopic submucosal dissection (ESD) enables direct submucosal dissection so that even large early-stage gastrointestinal tumors can be resected en bloc. ESD has recently been applied to the colorectum since it was originally developed for use in the stomach. However, colorectal ESD is technically more difficult with an increased risk of perforation compared with gastric ESD. In addition, this procedure is seldom performed in Western countries. Consequently, further technical advances and the availability of a suitable clinical training system are required for the extensive use of colorectal ESD. In this topic highlight, we review the most recent developments in colorectal ESD.
Submucosal injection solution for gastrointestinal tract endoscopic mucosal resection and endoscopic submucosal dissection
Toshio Uraoka, Yutaka Saito, Kazuhide Yamamoto, Takahiro Fujii
Drug Design, Development and Therapy , 2008, DOI: http://dx.doi.org/10.2147/DDDT.S3219
Abstract: bmucosal injection solution for gastrointestinal tract endoscopic mucosal resection and endoscopic submucosal dissection Review (4814) Total Article Views Authors: Toshio Uraoka, Yutaka Saito, Kazuhide Yamamoto, Takahiro Fujii Published Date August 2008 Volume 2008:2 Pages 131 - 138 DOI: http://dx.doi.org/10.2147/DDDT.S3219 Toshio Uraoka1, Yutaka Saito2, Kazuhide Yamamoto1, Takahiro Fujii3 1Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan; 2Division of Endoscopy, National Cancer Center Hospital, Tokyo, Japan; 3TF Clinic, Tokyo, Japan Abstract: Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) have provided new alternatives for minimally invasive treatment of gastrointestinal adenomas and early-stage cancers that involve a minimum risk of lymph-node metastasis. The use of submucosal injections is essential to the success of these endoscopic resection techniques. The “ideal” submucosal injection solution should provide a sufficiently high submucosal fluid cushion for safe and effective EMRs and ESDs while also preserving lesion tissue for accurate histopathological assessment. In the past, normal saline (NS) solution was commonly used for this purpose, but it is difficult to achieve the proper submucosal elevation and maintain the desired height with NS. Therefore, other safe and effective facilitative submucosal injection solutions have been developed that also take into account relevant cost-benefit considerations. This review examines recent advances in the development of effective submucosal injection solutions for use during endoscopic resections.
Effectiveness of narrow-band imaging magnification for invasion depth in early colorectal cancer
Masakatsu Fukuzawa, Yutaka Saito, Takahisa Matsuda, Toshio Uraoka, Takao Itoi, Fuminori Moriyasu
World Journal of Gastroenterology , 2010,
Abstract: AIM: To evaluate the surface microvascular patterns of early colorectal cancer (ECC) using narrow-band imaging (NBI) with magnification and its effectiveness for invasion depth diagnosis.METHODS: We studied 112 ECC lesions [mucosal/submucosal superficial (m/sm-s), 69; sm-deep (sm-d), 43] ≥ 10 mm that subsequently underwent endoscopic or surgical treatment at our hospital. We compared microvascular architecture revealed by NBI with magnification to histological findings and then to magnification colonoscopy pit pattern diagnosis.RESULTS: Univariate analysis indicated vessel density: non-dense (P < 0.0001); vessel regularity: negative (P < 0.0001); caliber regularity: negative (P < 0.0001); vessel length: short (P < 0.0001); and vessel meandering: positive (P = 0.002) occurred significantly more often with sm-d invasion than m/sm-s invasion. Multivariate analysis showed sm-d invasion was independently associated with vessel density: non-dense [odds ratio (OR) = 402.5, 95% confidence interval (CI): 12.4-13 133.1] and vessel regularity: negative (OR = 15.9, 95% CI: 1.2-219.1). Both of these findings when combined were an indicator of sm-d invasion with sensitivity, specificity and accuracy of 81.4%, 100% and 92.9%, respectively. Pit pattern diagnosis sensitivity, specificity and accuracy, meanwhile, were 86.0%, 98.6% and 93.8%, respectively, thus, the NBI with magnification findings of non-dense vessel density and negative vessel regularity when combined together were comparable to pit pattern diagnosis.CONCLUSION: Non-dense vessel density and/or negative vessel regularity observed by NBI with magnification could be indicators of ECC sm-d invasion.
Efficacy of capillary pattern type IIIA/IIIB by magnifying narrow band imaging for estimating depth of invasion of early colorectal neoplasms
Hiroaki Ikematsu, Takahisa Matsuda, Fabian Emura, Yutaka Saito, Toshio Uraoka, Kuang-I Fu, Kazuhiro Kaneko, Atsushi Ochiai, Takahiro Fujimori, Yasushi Sano
BMC Gastroenterology , 2010, DOI: 10.1186/1471-230x-10-33
Abstract: A series of 127 consecutive patients with 130 colorectal lesions were evaluated from October 2005 to October 2007 at the National Cancer Center Hospital East, Chiba, Japan. Lesions were classified as CP type IIIA or type IIIB according to the NBI CP classification. Lesions were histopathologically evaluated. Inter and intraobserver variabilities were assessed by three colonoscopists experienced in NBI.There were 15 adenomas, 66 intramucosal cancers (pM) and 49 submucosal cancers (pSM): 16 pSM superficial (pSM1) and 33 pSM deep cancers (pSM2-3). Among lesions diagnosed as CP IIIA 86 out of 91 (94.5%) were adenomas, pM-ca, or pSM1; among lesions diagnosed as CP IIIB 28 out of 39 (72%) were pSM2-3. Sensitivity, specificity and diagnostic accuracy of the CP type III for differentiating pM-ca or pSM1 (<1000 μm) from pSM2-3 (≥1000 μm) were 84.8%, 88.7 % and 87.7%, respectively. Interobserver variability: κ = 0.68, 0.67, 0.72. Intraobserver agreement: κ = 0.79, 0.76, 0.75Identification of CP type IIIA/IIIB by magnifying NBI is useful for estimating the depth of invasion of early colorectal neoplasms.Following complete surgical resection it has been found that colorectal cancers confined to the intramucosal layer (pM) or invading less than 1000 μm into the submucosa (pSM1), with no lymphovascular invasion or signs of poor differentiated histology do not have lymph node (LN) metastasis. In contrast, lesions invading more than 1000 μm into the submucosa (pSM2-3) have a 6-12% LN metastatic rate [1-3]. Therefore, in vivo estimation of the depth of invasion in early colorectal lesions may be important for an adequate therapeutic strategy.Several studies on the adenoma-carcinoma sequence have demonstrated a gradual increment in microvessel density and a reduction in the apoptosis process during the progression from low dysplasia to high dysplasia and cancer [4]. In addition it is well recognized that angiogenesis performs a critical role in the development of solid tumors [5,6] a
CO insufflation for potentially difficult colonoscopies: Efficacy when used by less experienced colonoscopists
Toshio Uraoka, Jun Kato, Motoaki Kuriyama, Keisuke Hori, Shin Ishikawa, Keita Harada, Koji Takemoto, Sakiko Hiraoka, Hideyuki Fujita, Joichiro Horii, Yutaka Saito, Kazuhide Yamamoto
World Journal of Gastroenterology , 2009,
Abstract: AIM: To clarify the effectiveness of CO2 insufflation in potentially difficult colonoscopy cases, particularly in relation to the experience level of colonoscopists.METHODS: One hundred twenty potentially difficult cases were included in this study, which involved females with a low body mass index and patients with earlier abdominal and/or pelvic open surgery or previously diagnosed left-side colon diverticulosis. Patients receiving colonoscopy examinations without sedation using a pediatric variable-stiffness colonoscope were divided into two groups based on either CO2 or standard air insufflation. Both insufflation procedures were also evaluated according to the experience level of the respective colonoscopists who were divided into an experienced colonoscopist (EC) group and a less experienced colonoscopist (LEC) group. Study measurements included a 100-mm visual analogue scale (VAS) for patient pain during and after colonoscopy examinations, in addition to insertion to the cecum and withdrawal times.RESULTS: Examination times did not differ, however, VAS scores in the CO2 group were significantly better than in the air group (P < 0.001, two-way ANOVA) from immediately after the procedure and up to 2 h later. There were no significant differences between either insufflation method in the EC group (P = 0.29), however, VAS scores for CO2 insufflation were significantly better than air insufflation in the LEC group (P = 0.023) immediately after colonoscopies and up to 4 h afterwards.CONCLUSION: CO2 insufflation reduced patient pain after colonoscopy in potentially difficult cases when performed by LECs.
Size does not determine the grade of malignancy of early invasive colorectal cancer
Takahisa Matsuda, Yutaka Saito, Takahiro Fujii, Toshio Uraoka, Takeshi Nakajima, Nozomu Kobayashi, Fabian Emura, Akiko Ono, Tadakazu Shimoda, Hiroaki Ikematsu, Kuang-I Fu, Yasushi Sano, Takahiro Fujimori
World Journal of Gastroenterology , 2009,
Abstract: AIM: To clarify the clinicopathological characteristics of small and large early invasive colorectal cancers (EI-CRCs), and to determine whether malignancy grade depends on size.METHODS: A total of 583 consecutive EI-CRCs treated by endoscopic mucosal resection or surgery at the National Cancer Center Hospital between 1980 and 2004 were enrolled in this study. Lesions were classified into two groups based on size: small (≤ 10 mm) and large (> 10 mm). Clinicopathological features, incidence of lymph node metastasis (LNM) and risk factors for LNM, such as depth of invasion, lymphovascular invasion (LVI) and poorly differentiated adenocarcinoma (PDA) were analyzed in all resected specimens.RESULTS: There were 120 (21%) small and 463 (79%) large lesions. Histopathological analysis of the small lesion group revealed submucosal deep cancer (sm: ≥ 1000 μm) in 90 (75%) cases, LVI in 26 (22%) cases, and PDA in 12 (10%) cases. Similarly, the large lesion group exhibited submucosal deep cancer in 380 (82%) cases, LVI in 125 (27%) cases, and PDA in 79 (17%) cases. The rate of LNM was 11.2% and 12.1% in the small and large lesion groups, respectively.CONCLUSION: Small EI-CRC demonstrated the same aggressiveness and malignant potential as large cancer.
Gene therapy strategies for treating brain tumors: Retroviruses are still good candidates for therapeutic vectors  [PDF]
Toshio Yawata, Keiji Shimizu
Open Journal of Genetics (OJGen) , 2013, DOI: 10.4236/ojgen.2013.32A1002
Abstract:

Glioblastoma multiforme (GBM) is the most common and aggressive primary brain tumor in adults. In the past few decades, many efforts have been made to improve the prognosis of GBM, however, with limited success. Many gene therapy strategies for GBM have been developed and a few have progressed to clinical trials. Retroviral vectors have superior features for gene therapy in brain cancers, including tumor specificity, immunogenicity, and longer half-life. Early gene therapy trials in GBM patients based on transplantation of retrovirus-producing cells into the brain failed to prove efficacious. Adenoviral vectors, which can be prepared as high-titer virus solutions and undergo efficient transduction in tumor cells, failed in clinical trials, likely due to immunogenicity and instability of gene expression. Alternative therapeutics such as oncolytic viruses that specifically target and destroy cancer cells are currently under investigation. In addition to novel vectors, retroviral vectors are still attractive candidates for use in gene therapy against brain tumors. Since yields of properly-packaged viral particles from virus-producing cells have been very limited so far, gene therapy by direct injection of hightiter retroviral vectors into the patients’ brains was not possible. To overcome these disadvantages, a packaging cell line that yields high-titer retroviral solutions was established by our group, enabling the direct injection of massive retroviral vector stocks directly into the brain. Mouse glioma models were effectively cured with a combination of a suicide gene/ prodrug system and a highly-concentrated retrovirus solution. Preclinical assessments, including that of replication-competent retroviruses and tumorigenicity of the combination method, have confirmed the safety of the highly-concentrated retrovirus solution. Addi tional studies are needed to address the clinical utility of such combination gene therapies. Taken together, these data suggest that retroviral vectors are still good candidates for development in gene therapy applications.

Late Quaternary Geomorphology of the Tonami Plain and Activity of the Tonami-Heiya Fault Zone, Toyama Prefecture, Central Japan  [PDF]
Toshio Kamishima, Akira Takeuchi
International Journal of Geosciences (IJG) , 2016, DOI: 10.4236/ijg.2016.77073
Abstract: The Holocene alluvial fans and flood plains formed by the Sho and Oyabe Rivers spread out in the Tonami plain from the central through the northern parts in the Toyama Prefecture, central Japan. Along the foot of the surrounding mountains and hills, higher, middle and lower terraces of late Pleistocene-Holocene in age are distributed. These terraces have been displaced, by the reverse dip-slip activities of Tonami-heiya fault zone in a sense of upheaval in the mountains side, even during the Holocene time. We examined stratigraphic cross section utilizing borehole data and geomorphologically analyzed 5 m-DEM data in order to elucidate the fault trace of the Isurugi fault which Tonami-heiya fault zone. As the results, the northern segment of Isurugi fault seems to run along the northeastern foot of Hodatsu Hills and extends underground through the lower-most Oyabe River into the Toyama Bay. Consequently, its total length reaches about 30 km. In the southern segment, a continuous fault scarplet was recognized to cut across the lower dissected fans. The slip-rate of Isurugi fault is estimated to be 0.31 - 0.64 m/kyr. In the Hokuriku region, reverse faulting and related folding with strike in a NE-SW direction have occurred during the late Quaternary. The hinge line of block movement due to the activities of the Tonami-heiya fault zone is revealed to have shifted from the mountain side into the plain side within the Holocene time. In conclusion, the Quaternary folding and faulting associated with the crustal warping at a wavelength of about 20 km is currently in progress, causing both the subsidence of Tonami plain and the upheaval of surrounding mountains and hills.
Numerical Study on Heat Transfer Characteristics of Heated/Cooled Rods Having a Composite Board in between: Effect of Thermal Vias  [PDF]
Yasushi Koito, Toshio Tomimura
Journal of Electronics Cooling and Thermal Control (JECTC) , 2017, DOI: 10.4236/jectc.2017.74008
Abstract: By placing a sample between a heated and a cooled rod, a thermal conductivity of the sample can be evaluated easily with the assumption of a one-dimensional heat flow. However, a three-dimensional constriction/spreading heat flow may occur inside the rods when the sample is a composite having different thermal conductivities. In order to investigate the thermal resistance due to the constriction/spreading heat flow, the three-dimensional numerical analyses were conducted on the heat transfer characteristics of the rods. In the present analyses, a polymer-based composite board having thermal vias was sandwiched between the rods. From the numerical results, it was confirmed that the constriction/spreading resistance of the rods was strongly affected by the thermal conductivity of the rods as well as the number and size of the thermal vias. A simple equation was also proposed to evaluate the constriction/spreading resistance of the rods. Fairly good agreements were obtained between the numerical results and the calculated ones by the simple equation. Moreover, the discussion was also made on an effective thermal conductivity of the composite board evaluated with the heated and the cooled rod.
Coefficient Conditions for Harmonic Close-to-Convex Functions
Toshio Hayami
Abstract and Applied Analysis , 2012, DOI: 10.1155/2012/413965
Abstract: New sufficient conditions, concerned with the coefficients of harmonic functions ()=?()
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