Biomedical subjects

Akihiko Uchiyama

Publications and source records attributed to Akihiko Uchiyama.

12 recordsLinked to original sources

PubMed2006

Complete extirpation of a bronchogenic cyst causing recurrent laryngeal nerve palsy by thoracoscopy: report of a case.

We excised a bronchogenic cyst causing recurrent laryngeal nerve palsy using thoracoscopic surgery. A 28-year-old woman presented after the sudden onset of hoarseness, and laryngoscopic examination showed left vocal cord palsy. Computed tomography and magnetic resonance imaging showed a cystic mass, 4 cm in diameter, in the aortopulmonary window. Thoracoscopic examination revealed that the mass was adhered to the recurrent laryngeal nerve below the aortic arch. We extirpated the cyst via thoracoscopy without any injury to the nerves or major blood vessels. This case illustrates the benefits of thoracoscopic surgery for providing good visualization of the perineural structures and as a safe surgical treatment for a cystic mass in the aortopulmonary window.

Adult↗

PubMed2005

MAP-based kinetic analysis for voxel-by-voxel compartment model estimation: detailed imaging of the cerebral glucose metabolism using FDG.

We propose a novel algorithm for voxel-by-voxel compartment model analysis based on a maximum a posteriori (MAP) algorithm. Voxel-by-voxel compartment model analysis can derive functional images of living tissues, but it suffers from high noise statistics in voxel-based PET data and extended calculation times. We initially set up a feature space of the target radiopharmaceutical composed of a measured plasma time activity curve and a set of compartment model parameters, and measured the noise distribution of the PET data. The dynamic PET data were projected onto the feature space, and then clustered using the Mahalanobis distance. Our method was validated using simulation studies, and compared with ROI-based ordinary kinetic analysis for FDG. The parametric images exhibited an acceptable linear relation with the simulations and the ROI-based results, and the calculation time took about 10 min. We therefore concluded that our proposed MAP-based algorithm is practical.

Algorithms↗

PubMed2004

Sphere-filled organ model for virtual surgery system.

We have been developing a virtual surgery system that is capable of simulating surgical maneuvers on elastic organs. In order to perform such maneuvers, we have created a deformable organ model using a sphere-filled method instead of the finite element method. This model is suited for real-time simulation and quantitative deformation. Furthermore, we have equipped this model with a sense of touch and a sense of force by connecting it to a force feedback device. However, in the initial stage the model became problematic when faced with complicated incisions. Therefore, we modified this model by developing an algorithm for organ deformation that performs various, complicated incisions while taking into account the effect of gravity. As a result, the sphere-filled model allowed our system to respond to various incisions that deform the organ. Thus, various physical manipulations that involve pressing, pinching, or incising an organ's surface can be performed. Furthermore, the deformation of the internal organ structures and changes in organ vasculature can be observed via the internal spheres' behavior.

Animals↗

PubMed2003

Interferon-gamma suppresses transforming growth factor-beta-induced invasion of gastric carcinoma cells through cross-talk of Smad pathway in a three-dimensional culture model.

We reconstituted a three-dimensional gastric carcinoma model similar to invasive gastric carcinoma tissue. This model consists of a human gastric carcinoma cell line, GCTM-1, a human fibroblast cell line, TIG-1-20, and transforming growth factor-beta (TGF-beta)-containing type I collagen gel. Using this model, we were able to observe the growth of the two cell types, especially carcinoma cell invasive growth, in real time for more than 30 days. TGF-beta and TIG-1-20 were essential for GCTM-1 invasive growth and proliferation, respectively. TGF-beta induced the enhanced expression of matrix metalloproteinase 9 (MMP9) and urokinase-type plasminogen activator (uPA) in GCTM-1 at both the protein and enzymatic activity levels. The TGF-beta-induced invasion of GCTM-1 was inhibited by MMP9- or uPA-antisense (AS) oligonucleotide transfection to GCTM-1. When exogenous interferon-gamma (IFN-gamma) was added to this model, TGF-beta-dependent GCTM-1 invasion was significantly inhibited, concomitant with the decreased expression of MMP9 and uPA. The intracellular signal transduction of Smad was examined to analyse the mechanism of the inhibitory effect of IFN-gamma. TGF-beta accelerated the phosphorylation of Smad2/3 and nuclear translocation of the Smad2/3-Smad4 complex in GCTM-1, but these TGF-beta-induced effects were significantly inhibited by IFN-gamma-induced Smad7 expression. When GCTM-1 was cotransfected with AS oligonucleotide of Smad2 and Smad3, the TGF-beta-induced invasion of GCTM-1 disappeared. In addition, the inhibitory effect of IFN-gamma on TGF-beta-dependent GCTM-1 invasion vanished by the AS oligonucleotide of Smad7 transfection. These results indicate that IFN-gamma inhibits TGF-beta-dependent GCTM-1 invasion through cross-talk in the Smad pathway. IFN-gamma may be a new therapeutic tool for TGF-beta-expressed invasive carcinomas.

Cell Line↗

PubMed2003

Inhibition of interferon-gamma-activated nuclear factor-kappa B by cyclosporin A: A possible mechanism for synergistic induction of apoptosis by interferon-gamma and cyclosporin A in gastric carcinoma cells.

We previously reported synergistic induction of apoptosis by IFN-gamma plus either cyclosporin A (CsA) or tacrolimus (FK506) in gastric carcinoma cells. In this study, we aimed to elucidate the mechanism for this synergistic induction of apoptosis. IFN-gamma plus CsA synergistically induced caspase-3 mediated apoptosis in gastric carcinoma cells. Although IFN-gamma induced activation of signal transducer and activator of transcription1 (STAT1) and expression of interferon regulatory factor-1 (IRF-1) mRNA, IFN-gamma alone was not able to induce caspase-3 activation and apoptosis. When gastric carcinoma cells were treated with cyclohexamide, a protein synthesis inhibitor, following IFN-gamma pretreatment, caspase-3 was activated, and apoptosis was markedly induced. These findings suggest the existence of IFN-gamma-induced anti-apoptotic pathway and we evaluated the effect of IFN-gamma and CsA on calcium-sensitive nuclear factor-kappa B (NF-kappa B) activation. IFN-gamma increased intracellular calcium ion concentration ([Ca(2+)](i)) consisting of a spike and a sustained phase, and the latter was completely abrogated by CsA. Activation of NF-kappa B occurred in response to IFN-gamma, and which was markedly inhibited by either CsA or FK506. NF-kappa B decoy also enhanced the cytotoxic effect of IFN-gamma. These results suggest that IFN-gamma may simultaneously induce the STAT1-mediated apoptotic pathway and the anti-apoptotic pathway through calcium-activated NF-kappa B and that inhibition of the latter by CsA may result in dominance of the apoptosis-inducing pathway.

Antineoplastic Agents↗

PubMed2003

Laparoscopic gastric surgery in a Japanese institution: analysis of the initial 100 procedures.

BACKGROUND: Although endoscopic surgical procedures are popular in various fields, reports on its use in gastric surgical procedures are limited. This study was designed to review our initial experience with laparoscopic gastric surgical techniques to evaluate indications and surgical results. STUDY DESIGN: We undertook a retrospective analysis of 100 patients (66 men and 34 women, mean age 63 years) who underwent laparoscopic gastric surgical procedures between 1995 and 2001. Procedures performed were distal gastrectomy (n = 76), wedge resection (n = 20), and intragastric surgical procedures (n = 4). Patients were divided into two groups according to the date of the procedure, from the earliest to the most recent. RESULTS: There were 85 patients with gastric cancers, 14 submucosal tumors, and 1 duodenal ulcer. In 8 cases conversion was made to an open surgical procedure. Operation times required for distal gastrectomy, wedge resection, and intragastric surgical procedures were 330 +/- 69, 144 +/- 34, and 298 +/- 106 min, and blood loss was 354 +/- 251, 56 +/- 94, and 33 +/- 58 g, respectively. Complications included transient anastomotic stenosis (n = 5), leakage (n = 4), and bleeding (n = 1) after distal gastrectomy, and bleeding (n = 1) after intragastric surgical procedures. There were no complications after wedge resection. Comparing the first and second halves of the series, the percentage of distal gastrectomy significantly increased from 66% to 86% (p = 0.02) and the number of dissected lymph nodes at this procedure increased from 20 +/- 13 to 33 +/- 17 (p < 0.01). CONCLUSIONS: Laparoscopic gastric surgical procedures are safe and feasible for early gastric cancers and submucosal tumors. Technical advances in lymph node dissection have made distal gastrectomy a leading and increasingly popular laparoscopic procedure for early gastric cancer.

Aged↗

PubMed2003

Development of a new three-dimensional endoscopic ultrasound system through endoscope shape monitoring.

We have developed a new three-dimensional (3D) endoscopic ultrasound system (EUS) with convex scanning echoendoscope to diagnose and navigate for endoscopic puncture using the 3D image. To detect the position of the probe and to monitor the shape of the scope inside the body, we use a fiber optic tracking system which is shaped like a ribbon (Shapetape, Measurand Inc.). The fiber optic tracking system could measure bend and twist at each position of the ribbon. The position of the tip of the echoendoscope is allotted to a 2D image, and the system can reconstruct and visualize a 3D image in real-time. We have reported results of our experimental studies and animal studies.

Endosonography↗

PubMed2003

Dynamic deformation of elastic organ model and the VR cockpit for virtual surgery and tele-surgery.

This paper describes a deformable organ model suited for a real-time surgical simulation system. This proposed organ model allows us to perform surgical maneuvers such as pressing, pinching, various incisions, resection and to show the deformation of the inner structures such as blood vessels on our system. At the same time, we have been developing a VR cockpit suited for virtual surgery and tele-surgery. Using our cockpit, our system allows us to provide the users with an environment closely resembling the open surgery situation.

Computer Simulation↗

PubMed2003

Development of a data fusion system using color information for real-time intraoperative liver surface measurement.

The goal of our study is to develop a data fusion system, which enables surgeons to easily visualize the inner structures of elastic organs during open surgery. We chose the liver as the focus of this study due to its easily deformable nature and complex vascular structures. To do so, we propose using preoperative data and supplementary intraoperative data. We captured a sequence of liver surface data for the intraoperative data by using trinocular stereo and we applied them to the preoperative 3D model's surface. Then, we modified the model to fit the intraoperative liver condition and portrayed the model's inner structures. With this method, we could establish this system.

Animals↗

PubMed2003

Real-time volumetric deformation for surgical simulation using force feedback device.

We have aimed to develop a virtual surgery system that realizes the performance of surgical maneuvers on elastic organs and to construct an elastic organ model known as sphere-filled model. In this paper we describe a new method of deforming volumetric data in real time by using sphere-filled model. As well we modified this model to take the interference between soft tissue and rigid tissue to consideration. Furthermore basic surgical maneuvers (pushing, pinching and incision) and connection with force feedback device are realized on this model similarly to our surface model.

Computer Simulation↗

PubMed2002

A large quantity of CD3-/CD19-/CD16- lymphocytes in malignant pleural effusion from a patient with recurrent cholangio cell carcinoma.

Tumor infiltrating lymphocytes (TILs) are candidates for adoptive cellular immunotherapy. Here we report on a patient whose TILs presented unusual lymphocyte antigens. Pleural effusions were collected from a 47-year-old man with recurrent cholangio cell carcinoma and malignant effusion. Effusion-associated lymphocytes (EALs) were separated by Ficoll-Hypaque gradient, and the EAL phenotype was determined by flow cytometry. The percentage of positive cells was determined for each lymphocyte-related differentiation antigen. The percentages of CD3+, CD19+, and CD16+ lymphocyte subpopulations among EALs were 20%, 7%, and 3%, respectively. Nearly 70% of EALs were CD3-/CD19-/CD56-/CD16- cells. The phenotypes of peripheral blood lymphocytes (PBLs) collected simultaneously from the patient's peripheral blood were CD3+ (52%), CD19+ (20%), and CD16+ (20%). When EALs were cultured in medium without pleural effusion, T cell-related antigens, but not B cell- or natural killer (NK) cell-related antigens, were newly expressed on EALs, and this expression reached a plateau after 48 h in culture. The proportions of CD3+, CD19+, and CD16+ cells were 69%, 7%, and 3%, respectively. However, when EALs were cultured in medium with pleural effusion, increased expression of T cell-related antigens was not observed; the proportions of CD3+, CD19+, and CD16+ cells were 16%, 6%, and 1%, respectively. Neither total cell numbers nor cellular viability of EALs changed significantly after in-vitro culture, suggesting that significant proliferation or death of EALs did not occur during the culture period. Co-culture of the patient's PBLs with autologous pleural effusion for 96 h did not alter the expression of lymphocyte-related antigens on the PBLs. These results indicate that expression of T cell-related antigens, but not B cell- or NK cell-related antigens, on EALs was blocked temporarily by the malignant pleural effusion. This is the first report concerning the existence of a large quantity of unclassified lymphocytes in which the T cell-related antigens were reversibly masked in the malignant pleural effusion.

Antigens, CD19↗

PubMedDate not supplied

Candidate host marker for peritoneal dissemination.

BACKGROUND: Mesothelial cell injury is common in peritoneal dissemination (PD) of cancer cells. The plasminogen activator system, including urokinase-type plasminogen activator (uPA) and type-1 plasminogen activator inhibitor (PAI-1), plays an important role in repair of the peritoneum damaged by several types of peritonitis. We investigated and compared the expression of uPA and PAI-1 in the peritoneum of cancer patients with and without PD. MATERIALS AND METHODS: Cancer cell-positive peritoneum and cancer cell-negative peritoneum specimens were obtained from 11 patients with PD, while peritoneum specimens were also obtained from 24 patients without PD. The presence or absence of cancer cells in the peritoneal tissues was confirmed by both hematoxylin-eosin staining and reverse transcriptase-polymerase chain reaction (RT-PCR) detection of carcinoembryonic antigen (CEA) mRNA. uPA and PAI-1 mRNA expression in these peritoneal tissues was determined by RT-PCR and the proteins were localized immunohistochemically. The results were compared statistically. RESULTS: uPA mRNA was expressed in the cancer cell-positive peritoneum from 9 of the 11 (81.8%) patients with PD; PAI-1 mRNA was expressed in the peritoneal tissue from 10 of (91.9%) these patients. Either uPA or PAI-1 mRNA was expressed in the cancer cell-negative peritoneum from 8 (72.7%) of the 11 patients with PD, whereas uPA mRNA was expressed in none of the peritoneal tissues from the 24 patients without PD and PAI-1 mRNA was expressed in specimens from 4 (16.7%) of these patients. Immunohistochemical analysis revealed uPA and/or PAI-1 in the mesothelial cells and submesothelial fibroblasts in cancer cell-negative peritoneum from the patients with PD but not in peritoneum from the patients without PD. CONCLUSION: uPA transcription in the peritoneum may be a host marker indicating the existence of PD.

Adult↗