304 research outputs found
Outcome of Endoscopy-Assisted Microscopic Extended Transsphenoidal Surgery for Suprasellar Adult Craniopharyngiomas
Craniopharyngiomas are difficult to treat. The extended transsphenoidal approach has recently been described in several small series. We describe the usefulness of microscopy-assisted angled endoscopy for visualizing vital structures such as tumor attachment or tumor invasion to the pituitary stalk to achieve confident radical tumor removal. Between 2006 and 2010, 15 patients underwent the microscopy-assisted extended transsphenoidal approach for resection of entirely suprasellar craniopharyngiomas. Fourteen patients had the transinfundibular type, and one had the transinfundibular type with extension to the third ventricle. We observed color change within the pituitary stalk by endoscopy. The pituitary stalk was cut intentionally in 10 patients because of suspected tumor invasion surrounding the stalk. Total removal was accomplished in nine patients. Pathological specimens from the pituitary stalk showed tumor invasion spreading over the surface of the pituitary stalk, shown by a discolored pituitary stalk, and this was essential for confident radical tumor removal. Even after stalk resection, postoperative diabetes insipidus was minimal when a bright signal on T1 in the posterior lobe was not observed with preoperative magnetic resonance imaging. Confident radical tumor removal is possible with the introduction of the endoscopy-assisted microscopic extended transsphenoidal approach
Cooperative Step Climbing Using Connected Wheeled Robots and Evaluation of Remote Operability
The present study evaluates the remote operability of step climbing using two connected robots that are teleoperated by individual operators. In general, a teleoperated robot is manipulated by an operator who is viewing moving images from a camera, which is one of the greatest advantages of such a system. However, robot teleoperation is not easy when a teleoperated robot is affected by the force from another robot or object. We constructed a step climbing system using two connected teleoperated robots. A theoretical analysis and the results of simulations clarified the correlations among the robot velocity, the manipulation time of the robots, and the height of the front wheels when climbing a step. The experimental results demonstrate the step climbing ability of the teleoperated robot system
Potential Use of Folate-polyethylene glycol (PEG)-Appended Dendrimer (G3) Conjugate with alpha-Cyclodextrin as DNA Carriers to Tumor Cells
We previously reported that polyamidoamine STARBURST dendrimer (generation 3, G3) (dendrimer) conjugate with alpha-cyclodextrin (alpha-CyD) having an average degree of substitution of 2.4 of alpha-CyD (alpha-CDE) provided remarkable aspects as novel carriers for DNA and siRNA. To develop novel alpha-CDE derivatives with tumor cell specificity, we prepared folate-appended alpha-CDEs (Fol-alpha-CDEs) and folate-polyethylene glycol (PEG)-appended alpha-CDEs (Fol-PalphaCs) with the various degrees of substitution of folate (DSF), and evaluated in vitro and in vivo gene transfer activity, cytotoxicity, cellular association and physicochemical properties. In vitro gene transfer activity of Fol-alpha-CDEs (G3, DSF 2, 5 or 7) was lower than that of α-CDE (G3) in KB cells, folate receptor (FR)-overexpressing cancer cells. Of the three Fol-PalphaCs (G3, DSF 2, 5 or 7), Fol-PalphaC (G3, DSF 5) had the highest gene transfer activity in KB cells. The activity of Fol-PalphaC (G3, DSF 5) was significantly higher than that of alpha-CDE (G3) in KB cells, but not in A549 cells, FR-negative cells. Negligible cytotoxicity of the pDNA complex with Fol-PalphaC (G3, DSF 5) was observed in KB cells or A549 cells up to a charge ratio of 100/1 (carrier/pDNA). The cellular association of the pDNA complex with Fol-PalphaC (G3, DSF 5) could be mediated by FR on KB cells, resulting in its efficient cellular uptake. Fol-PalphaC (G3, DSF 5) had higher binding affinity with folate binding protein (FBP) than alpha-CDE (G3), although the physicochemical properties of pDNA complex with Fol-PalphaC (G3, DSF 5) were almost comparable to that with alpha-CDE (G3), although the onset charge ratio and the compaction ability of Fol-PalphaC (G3, DSF 5) were slightly different. Fol-PalphaC (G3, DSF 5) tended to show higher gene transfer activity than alpha-CDE (G3) 12 h after intratumoral administration in mice. These results suggest that Fol-PalphaC (G3, DSF 5), not Fol-alpha-CDEs, could be potentially used as a FR-overexpressing cancer cell-selective DNA carrier
A Preliminary Study on Perception of Accelerated Heartbeat
The purpose of this study was to investigate on the perception of a bodily symptom, 'accelerated heartbeat'. In this study, three experimental conditions were set up. First condition was the true-feedback (TF) condition, in which subject was presented true feedback signals corresponding to actual heartbeats. Second condition was the false-feedback (FF) condition, in which subject was presented the false feedback signals being irrelevant to actual heartbeats. Third condition was the no-feedback (NF) condition. The major results were as follows ; (1) In the TF-condition, abilities to perceive accelerated heartbeat were different inter- and intra-subjects. (2) In the FF-condition, almost subjects perceived accelerated heartbeat were inaccurate. (3) Frequencies of perception in the NF-condition were fewer than in the TF-condition. As the cue for perception of accelerated heartbeat, subjects used not only information relevant to heartbeats such as a pulse but also respiration, degree of concentration, and so on. These results suggested that abilities to perceive accelerated heartbeat were different inter- and intra-individuals, even when they could discriminate their heartbeats perfectly, and that, if an information unrelated to accelerated heartbeat was used as the cue, subject perceived their accelerated heartbeat inaccurately. Further, the cue for interoceptive perception of accelerated heartbeat was not restricted information directly relevant to heartbeats
X線自由電子レーザーによる分子の電子密度推定
要旨あり最適化技術に基づく統計的推論研究詳
Morphological and Histopathological Changes in Orofacial Structures of Experimentally Developed Acromegaly-Like Rats: An Overview
Tongue enlargement and mandibular prognathism are clinically recognized in almost all patients with acromegaly. An acromegaly-like rat model recently developed by exogenous administration of insulin-like growth factor I (IGF-I) was used to investigate morphological and histopathological changes in orofacial structures and to clarify whether these changes were reversible. Exogenous administration of IGF-I evoked specific enlargement of the tongue with identifiable histopathological changes (increased muscle bundle width, increased space between muscle bundles, and increased epithelial thickness), elongation of the mandibular alveolar bone and ascending ramus, and lateral expansion of the mandibular dental arch. Regarding histopathological changes in the mandibular condyle, the cartilaginous layer width, bone matrix ratio, and number of osteoblasts were all significantly greater in this rat model. After normalization of the circulating IGF-I level, tongue enlargement and histopathological changes in the tongue and mandibular condyle were reversible, whereas morphological skeletal changes in the mandible remained
Phase retrieval from single biomolecule diffraction pattern
In this paper, we propose the SPR (sparse phase retrieval) method, which is a
new phase retrieval method for coherent x-ray diffraction imaging (CXDI).
Conventional phase retrieval methods effectively solve the problem for high
signal-to-noise ratio measurements, but would not be sufficient for single
biomolecular imaging which is expected to be realized with femto-second x-ray
free electron laser pulses. The SPR method is based on the Bayesian statistics.
It does not need to set the object boundary constraint that is required by the
commonly used hybrid input-output (HIO) method, instead a prior distribution is
defined with an exponential distribution and used for the estimation.
Simulation results demonstrate that the proposed method reconstructs the
electron density under a noisy condition even some central pixels are masked.Comment: 13 pages, 13 figures, submitted for a journa
Novel device prototyping for endoscopic cell sheet transplantation using a three-dimensional printed simulator
手術負担の少ない内視鏡による心臓表面への細胞シート移植デバイスを開発 --心臓再生医療への応用を目指して--. 京都大学プレスリリース. 2020-11-20.Introduction: Considering higher risks of candidates for cardiac regenerative therapy with compromised cardiac function, it is anticipated to develop less invasive surgical procedures. In the present study, we aimed to develop a prototype of totally endoscopic cell sheet delivery device and evaluate the surgical technique for epicardial cell sheet placement using three-dimensional (3D) printed simulators based on human computed tomography data. Methods: We designed an endoscopic cell sheet delivery device with outer and inner frame with self-expandable applicator which can be opened in thoracic cavity. We launched spout line to provide liquids on the applicator surface and tension line to gently bend the applicator dorsally. We prepared human mesenchymal stem cell (MSC) sheets and compared wet/dry conditions of 3D printed heart/porcine heart and applicator to identify suitable conditions for cell sheet transplantation. Finally we validated the feasibility of endoscopic transplantation to anterior and lateral wall of left ventricle using 3D printed simulators. Results: Moist condition of both 3D printed heart/porcine heart surface and applicator at transplantation yielded highest successful rate (100%, p = 0.0197). For both endoscopic transplantation sites, MSC sheets were successfully deployed. The procedure duration was 157 ± 23 s for anterior wall and 123 ± 13 s for the lateral wall in average, respectively. Conclusions: We developed a novel prototype of endoscopic cell sheet delivery device for minimally-invasive cardiac regenerative therapy utilizing a 3D printed simulator. The commercialization of the prototype may provide a safe minimally-invasive method to deliver potential cardiac regenerative therapy in the future
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