24 results on '"Ando, Yasuhisa"'
Search Results
2. A combined score for predicting clinically relevant postoperative pancreatic fistula based on inflammatory parameters and drainage fluid culture results on postoperative day 3.
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Suto, Hironobu, Matsukawa, Hiroyuki, Ando, Yasuhisa, Oshima, Minoru, Fuke, Takuro, Norikane, Takashi, Sanomura, Takayuki, Kamada, Hideki, Kobara, Hideki, Masaki, Tsutomu, Kumamoto, Kensuke, and Okano, Keiichi
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PANCREATIC fistula , *DRAINAGE , *PANCREATIC surgery , *SURGICAL complications , *MULTIVARIATE analysis , *BACTERIAL diseases , *PANCREATECTOMY - Abstract
Background: Clinically relevant postoperative pancreatic fistula (CR‐POPF) after pancreatic resection can lead to severe postoperative complications. POPF is defined based on postoperative day (POD) 3 drainage fluid amylase level. POPF correlates with inflammatory parameters as well as drainage fluid bacterial infection. However, a standardized model based on these factors for predicting CR‐POPF remains elusive. We aimed to identify inflammatory parameter‐ and drainage fluid culture‐related risk factors for CR‐POPF on POD 3 after pancreatoduodenectomy (PD) and distal pancreatectomy (DP). Methods: Data from 351 patients who underwent PD or DP between 2013 and 2022 at a single institution were retrospectively analyzed. Risk factors for CR‐POPF were investigated using multivariate analyses, and a prediction model combining the risk factors for CR‐POPF was developed. Results: Of the 351 patients, 254 and 97 underwent PD and DP, respectively. Multivariate analyses revealed that drainage fluid amylase level ≥722 IU/L, culture positivity, as well as neutrophil count ≥5473/mm3 on POD 3 were independent risk factors for CR‐POPF in PD group. Similarly, drainage fluid, amylase level ≥500 IU/L, and culture positivity on POD 3 as well as pancreatic thickness ≥11.1 mm were independent risk factors in the DP group. The model for predicting CR‐POPF achieved the maximum overall accuracy rate when the number of risk factors was ≥2 in both the PD and DP groups. Conclusions: Inflammatory parameters on POD 3 significantly influence the risk of CR‐POPF onset after pancreatectomy. The combined models based on these values can accurately predict the risk of CR‐POPF after pancreatectomy. [ABSTRACT FROM AUTHOR]
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- 2024
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3. Investigating the effect of interatomic distance on friction force through MEMS-AFM based experiment.
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Ando, Yasuhisa and Shiina, Yuto
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INTERATOMIC distances , *MICROFLUIDIC devices , *ATOMIC force microscopes , *FRICTION , *ELECTROSTATIC actuators , *SURFACE strains - Abstract
[Display omitted] • A microdevice driven by a comb actuator was fabricated using the DRIE process. • The MEMS-based microdevice was integrated onto an AFM. • The AFM was employed to quantify the friction force on the strained Si surface. • The FFM image was consistent with the strain image acquired through FEM analysis. • A 1.2% variation in atomic distance resulted in a 9% reduction in the friction force. Investigations on the influence of the interatomic distance (IAD) on friction are crucial for gaining a better understanding of friction and comprehending the essential nature of graphene friction. We obtained friction force microscopy (FFM) images of strained surfaces to examine how the IAD affects the friction force. First, using microelectromechanical system (MEMS) fabrication techniques, we fabricated a strain-generating microdevice that can generate surface strain on its Si surface by an electrostatic comb actuator. The microdevice was installed in a high vacuum atomic force microscope. Next, FFM measurements were performed on the stress concentration section of the microdevice using a Si cantilever. The driving voltage on the comb actuator was switched on/off for each scan line during a single raster scan. This procedure allowed us to obtain FFM images representing the surface strain (i.e., the IAD variation) by excluding friction/wear-induced disturbances. The FFM images agreed well with the strain distribution calculated by the elastic finite element method analysis. The relative reduction of the friction was approximately 9% against the calculated strain of 1.2%. [ABSTRACT FROM AUTHOR]
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- 2023
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4. Friction characteristics between two nanostripe surfaces.
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Hayashi, Motoki and Ando, Yasuhisa
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FRICTION , *ORTHOGONAL surfaces , *SLIDING friction , *SILICON surfaces , *SURFACE texture - Abstract
In order to elucidate the friction characteristics of different types of periodic surface patterns, friction tests were performed on nanostripe surfaces fabricated on cylindrical surfaces with a curvature radius of 150 mm at sliding speeds of 0.7 μm/s–0.7 mm/s. On the nanostripe surfaces, microgrooves were arrayed at a pitch of 6 μm, while nanogrooves were formed on the ridges between neighboring microgrooves at a pitch of approximately 500 nm. The friction coefficient was the lowest at 0.06 when a nanostripe surface was rubbed against a smooth silicon surface at a speed of 0.7 μm/s and the sliding direction was parallel to the grooves. For combinations consisting of two nanostripe surfaces, the maximum friction coefficient was measured for the configuration wherein the grooves of the nanostripes on the two surfaces were perpendicular to the sliding direction, and for the configuration wherein the grooves of the nanostripes on the two surfaces were orthogonal to each other. In the case of the former configuration, the sticking force generated by the slopes of the microgrooves had a determining effect on the measured friction force. • Cross-cylinder contact configuration enabled a contact area larger than pattern size. • Micro-patterned surfaces were fabricated by photolithography with thin Si wafers. • Constant friction coefficients were obtained by microgrooves under lubricated condition. • Nanogrooves persisted in wear traces due to varying wear rates of constituent metals. [ABSTRACT FROM AUTHOR]
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- 2019
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5. Low prevalence of biliary tract cancer with defective mismatch repair genes in a Japanese hospital-based population.
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Ando, Yasuhisa, Kumamoto, Kensuke, Matsukawa, Hiroyuki, Ishikawa, Ryou, Suto, Hironobu, Oshima, Minoru, Kamada, Hideki, Morishita, Asahiro, Kobara, Hideki, Matsunaga, Toru, Haba, Reiji, Masaki, Tsutomu, Suzuki, Yasuyuki, and Okano, Keiichi
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DNA mismatch repair , *IMMUNE checkpoint inhibitors , *HEREDITARY nonpolyposis colorectal cancer , *FAMILY history (Medicine) , *PROGNOSIS , *IMMUNOSUPPRESSION ,BILIARY tract cancer - Abstract
Recent studies have reported that immune checkpoint inhibitors are effective against various defective mismatch repair (dMMR)/microsatellite instability-high (MSI-H) cancers. A limited number of reports are available on the frequency of dMMR/MSI-H carcinoma in biliary tract cancer (BTC), describing its clinicopathological characteristics and prognosis. The latter carcinoma is also associated with Lynch syndrome (LS). The present study was performed to investigate the frequency of patients with dMMR/MSI-H in BTC and the clinical characteristics of BTC with dMMR/MSI-H in a single institution in Japan. A total of 116 patients with BTC who underwent curative surgical resection at Kagawa University Hospital between January 2008 and December 2017 were included. The protein expression levels of the mismatch repair (MMR) genes [mutL homolog 1 (MLH1), mismatch repair endonuclease PMS2 (PMS2), MutS homolog (MSH)2 and MSH6] were assessed by immunohistochemistry (IHC) using formalin-fixed paraffin-embedded tissue specimens. Subsequently, MSI testing was performed on patients who exhibited loss of MMR protein expression. Loss of expression of one or more proteins was detected in five cases (4.3%). Loss of MLH1/PMS2 expression was observed in one case of intrahepatic cholangiocarcinoma, whereas loss of PMS2 expression was noted in one case of perihilar cholangiocarcinoma. Loss of MSH2/MSH6 and MSH6 expression was noted in two cases of distal cholangiocarcinoma and loss of PMS2 expression in one case of ampullary carcinoma. Out of the five patients, two demonstrated MSI-H. Microsatellite stability was observed in two cases and for one case, no data were available. Two MSI-H cases were patients with loss of expression of MLH1/PMS2 and MSH2/MSH6. None of the five patients exhibited a past medical history or family history of suspected LS. The frequency of dMMR in BTC was ~5%, which was similar to that reported by similar studies performed in other countries. In the present study, IHC appeared to be more useful than MSI testing for detecting MMR abnormalities with regards to the detection rate. Furthermore, there may only be a limited number of patients with BTCs who are likely to benefit from the therapeutic effects of treatment with immune checkpoint inhibitors. [ABSTRACT FROM AUTHOR]
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- 2022
6. Efficacy of neoadjuvant chemoradiotherapy followed by pancreatic resection for older patients with resectable and borderline resectable pancreatic ductal adenocarcinoma.
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Suto, Hironobu, Oshima, Minoru, Ando, Yasuhisa, Matsukawa, Hiroyuki, Takahashi, Shigeo, Shibata, Toru, Kamada, Hideki, Kobara, Hideki, Masaki, Tsutomu, Kumamoto, Kensuke, Suzuki, Yasuyuki, and Okano, Keiichi
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OLDER patients , *PANCREATIC duct , *CHEMORADIOTHERAPY , *ADJUVANT chemotherapy , *PANCREATIC surgery , *ADENOCARCINOMA - Abstract
The benefit of preoperative treatment followed by pancreatic resection in older patients with pancreatic ductal adenocarcinoma (PDAC) remains unclear. In this retrospective analysis of prospectively collected data, we evaluated the significance and safety of preoperative treatment followed by curative resection for older PDAC patients. We evaluated 122 patients with resectable and borderline resectable PDAC who received neoadjuvant chemoradiotherapy (NACRT) followed by curative resection between 2009 and 2019. Changes in the prognostic nutritional indices during NACRT, surgical outcomes, and prognosis were compared between older (≥75 years, n = 44) and younger patients (<75 years, n = 78). The completion rate, adverse event rate, changes in prognostic nutritional indices during NACRT, and prognosis were similar between the groups. In multivariate analysis, an elevated C-reactive protein/albumin ratio (CRP/Alb) ≥ 33.1% during NACRT (p = 0.035) and no postoperative adjuvant chemotherapy (p = 0.041) were identified as significant predictors of overall survival. NACRT followed by pancreatic resection could be safely performed in older patients, with a similar prognosis as that of younger patients, despite an increased frequency of postoperative complications. Elevated CRP/Alb during NACRT and no postoperative adjuvant chemotherapy were poor prognostic factors for older patients. [ABSTRACT FROM AUTHOR]
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- 2023
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7. Development of Three-Dimensional Microstages Using Inclined Deep-Reactive Ion Etching.
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Ando, Yasuhisa, Ikehara, Tsuyoshi, and Matsumoto, Sohei
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AUTOMATIC control systems , *SEMICONDUCTOR wafers , *SILICON , *SEMICONDUCTORS , *OPTICAL instruments , *ELECTROMAGNETIC induction - Abstract
Three-dimensional (3-D) microstages driven by electrostatic comb actuators that provide continuous motion along three axes (x, y, and z) were designed and fabricated. Each 3-D microstage consisted of sets of traveling tables, suspension systems, and comb actuators. To convert lateral displacement of the comb actuators to vertical motion, one suspension system incorporated leaf springs inclined to a substrate. To efficiently construct the inclined leaf springs, we devised a fabrication technique that uses deep reactive ion etching. Three-dimensional microstages were then fabricated in a 20-μm-thick device layer on a silicon-on-insulator wafer. The maximum vertical (z) displacement of this 3-D microstage was 2.6 μm, and the maximum lateral displacement (x and y) was more than 6 μm in each direction, achieved by using support suspensions to suppress the interference between the comb actuators. A 3-D microstage was then installed in a commercial atomic force microscope, and a 3-D image of a grating was successfully measured without hysteresis using this 3-D microstage as the scanning device. [ABSTRACT FROM AUTHOR]
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- 2007
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8. Development of a microlateral force sensor and its evaluation using lateral force microscopy.
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Ando, Yasuhisa and Shiraishi, Naoki
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LATERAL loads , *ATOMIC force microscopy , *TORSION , *DETECTORS , *CANTILEVERS , *SCANNING probe microscopy , *MICROELECTROMECHANICAL systems - Abstract
A microlateral force sensor (MLFS) was developed and evaluated using atomic force microscopy (AFM). The sensor was attached to a sensing table supported by a suspension system. The lateral motion of the sensing table was activated by a comb actuator. The driving voltage to the comb actuator was controlled to maintain a constant position of the sensing table by detecting the tunneling current at a detector, which consisted of two electrodes where the bias voltage was applied. An AFM was used to apply a lateral force to the sensing table of the sensor. When the probe of a cantilever was pressed against the sensing table and a raster scanning was conducted, the driving voltage of the comb actuator changed to compensate the friction force between the probe and sensing table. AFM measurements of an asperity array on the sensing table were conducted, and a lateral force microscopy image (LFM) was obtained from the change in driving voltage. The image by MLFS was very similar to the LFM image that was conventionally obtained from torsion of the cantilever. The LFM image strongly correlated with the gradient image calculated from the AFM topographic image. The force sensitivity of the MLFS was determined by comparing the LFM image obtained by using the MLFS with the tangential force derived from the gradient of the AFM image. [ABSTRACT FROM AUTHOR]
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- 2007
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9. Lowering friction coefficient under low loads by minimizing effects of adhesion force and viscous resistance
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Ando, Yasuhisa
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FRICTION , *SPEED , *VACUUM - Abstract
Conditions (normal load, sliding speed, ambient conditions, and material) to obtain the lower friction coefficient were studied by measuring the friction and pull-off forces between a metal pin (copper or gold) and a plate (steel or single crystal silicon). First, a pin was rubbed against a plate under a normal load between −12 and 870 μN at a sliding speed between 0.012 and 9.6 μm/s. The friction force was measured during reciprocating sliding motion. The pull-off force was measured before and after each friction force measurement. All the force measurements were taken in high vacuum at 10−5 Pa, dry argon at 1 atm, and ambient humid air of 38 and 60% relative humidity. Then, the friction coefficient was calculated by dividing friction force by the sum of normal load and pull-off force. In high vacuum, when a copper pin was rubbed against either a silicon or steel plate, the friction coefficient decreased to less than 0.05 with decreasing sliding speed. The effect of sliding speed on the friction coefficient suggests that under a low normal load the viscous resistance of liquid contributed to the friction force. When a gold pin was rubbed against a silicon plate, the friction coefficient was not affected by sliding speed. [Copyright &y& Elsevier]
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- 2003
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10. Design, fabrication and testing of new comb actuators realizing three-dimensional continuous motions
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Ando, Yasuhisa, Ikehara, Tsuyoshi, and Matsumoto, Sohei
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ACTUATORS , *ION bombardment - Abstract
We have designed and developed three types of stage (types A, B and C) driven by comb actuators. Each stage consists of a traveling table, suspensions and a comb actuator(s). Types A and B lift-up the traveling table with and without a lateral displacement, respectively. Type C changes the angle of the traveling table. The key to realizing three-dimensional motions in the stages is in the geometry of the suspensions, which incorporate a pair of leaf springs inclined at 45° against the substrate. First, the motions of the suspensions were analyzed by finite element method (FEM). Then the three types of stage were fabricated on an silicon on insulator (SOI) wafer. The relation between the motion of the traveling table and driving voltage was examined for the three kinds of stage. The lift-up amount and tilting angle increased with higher driving voltage. The maximum lift-up amount of type A was 1 μm when the driving voltage was 170 V. For type B, the maximum lift-up amount was 1.9 μm when the tilting angle was less than 0.1°. The maximum tilting angle of type C was 0.3° at the driving voltage of 190 V. [Copyright &y& Elsevier]
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- 2002
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11. Friction properties of micro/nanogroove patterns in lubricating conditions.
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Ando, Yasuhisa and Sumiya, Takuro
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FRICTION , *BOUNDARY lubrication , *SURFACE texture - Abstract
Tribological properties can be improved by surface texturing; however, most of the conducted studies used microscale patterns. This study evaluated the lubrication properties of four different micro/nanogroove layouts (i.e., one straight layout and three different types of V-shaped layouts) created using the nanostripe fabrication technology. For each layout, microgrooves were arrayed at a pitch of 4 μm or 6 μm, and nanogrooves were formed on the ridge between these microgrooves. Friction tests were conducted at different loads and speeds using a single-crystal SiC disk as the counter specimen. We showed that patterns with 6 μm pitch microgrooves had a lower friction coefficient than those with 4 μm pitch microgrooves. The layouts with a higher ratio of nanogrooved area obtained a lower friction coefficient in high load and low speed conditions that are considered as boundary or mixed lubrication regimes. • V-shaped micro/nanogroove layouts were created on Si substrateby top-down fabrication. • Microgrooves reduced friction coefficient at higher sliding speed and lower load. • Higher ratios of nanogrooved area obtained lower friction coefficients. • Friction coefficient was lowest for a V-shaped layout with deeper microgrooves. [ABSTRACT FROM AUTHOR]
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- 2020
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12. Short- and Long-Term Outcomes of Neoadjuvant Chemoradiotherapy Followed by Pancreatoduodenectomy in Elderly Patients with Resectable and Borderline Resectable Pancreatic Cancer: A Retrospective Study.
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Suto, Hironobu, Fuke, Takuro, Matsukawa, Hiroyuki, Ando, Yasuhisa, Oshima, Minoru, Nagao, Mina, Takahashi, Shigeo, Shibata, Toru, Yamana, Hiroki, Kamada, Hideki, Kobara, Hideki, Okuyama, Hiroyuki, Kumamoto, Kensuke, and Okano, Keiichi
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OLDER patients , *PANCREATIC cancer , *PANCREATICODUODENECTOMY , *CHEMORADIOTHERAPY , *PANCREATIC duct - Abstract
Background: The efficacy of neoadjuvant chemoradiotherapy (NACRT) followed by pancreatoduodenectomy (PD) in elderly patients with pancreatic ductal adenocarcinoma (PDAC) remains unclear. Methods: This retrospective analysis of prospectively collected data examined the effect of NACRT followed by PD in elderly patients with PDAC. A total of 112 patients with resectable (R-) and borderline resectable (BR-) PDAC, who were planned for PD and received NACRT between 2009 and 2022, were assessed. Changes induced by NACRT, surgical outcomes, nutritional status, renal and endocrine functions, and prognosis were compared between elderly (≥75 years, n = 43) and non-elderly (<75 years, n = 69) patients over two years following PD. Results: Completion and adverse event rates during NACRT, nutritional status, renal function, endocrine function over two years postoperatively, and prognosis did not significantly differ between the two groups. Low prognostic index after NACRT and the absence of postoperative adjuvant chemotherapy may be adverse prognostic indicators for elderly patients undergoing NACRT for R- and BR-PDAC. Conclusions: Despite a higher incidence of postoperative complications, NACRT followed by PD can be safely performed in elderly patients, resulting in a prognosis similar to that in non-elderly patients. [ABSTRACT FROM AUTHOR]
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- 2024
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13. PS01.217: COMPARISON OF THE SHORT-TERM OUTCOMES OF LATERAL POSITIONING AND PRONE POSITIONING DURING THORACOSCOPIC ESOPHAGECTOMY.
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Kishino, Takayoshi, Ando, Yasuhisa, Suto, Hironobu, Asano, Eisuke, Oshima, Minoru, Fujiwara, Masao, Okano, Keiichi, Usuki, Hisashi, and Suzuki, Yasuyuki
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CHEST endoscopic surgery , *ESOPHAGEAL cancer , *ESOPHAGECTOMY , *SURGICAL site , *PATIENT positioning , *PNEUMOTHORAX , *HEMORRHAGE - Abstract
Background Video-assisted thoracoscopic esophagectomy (VATS-E) for esophageal cancer is being performed at an increasing number of institutions. In our institute, at first, we had performed VATS-E in the left lateral position without pneumothorax. But, we introduced VATS-E in the prone position with pneumothorax, because of difficulty of visual development for a surgical site by assistant. This study aimed to compare the two methods and to clarify the advantage in the prone position. Methods Thirty-one patients who underwent VATS-E at the Department of Gastroenterological Surgery, Kagawa University, from August 2013 to January 2018 were divided into two groups by the patient position. For the first 17 patients, we used the left lateral position (Group L); for the next 14 patients, we used the prone position (Group P). We compared the short-term outcomes in these two approaches. Results There were no significant differences in the most operative factors; duration of the thoracoscopic esophagectomy (354 min. in Group L and 309 min. in Group P, P = 0.153), operative hemorrhage (421 ml in Group L and 228ml in Group P, P = 0.054), infusion volume (8.8 ml/kg/hr. in Group L and 8.2ml/kg/hr. in Group P, P = 0.415), urinary volume (2.3 ml/kg/hr. in Group L and 1.7ml/kg/hr. in Group P, P = 0.202). However, C-reactive protein (CRP) level in post-operative day 3 (17.2 in Group L and 13.8 in Group P, P = 0.046) and procalcitonin (PCT) level in post-operative day 3 (1.8 in Group L and 0.3 in Group P, P = 0.049) was significantly lesser in Group P. And, Period until ambulation (4.0 days in Group L and 1.3 days in Group P, P < 0.001) was significantly shorter in Group P. Conclusion In conclusion, VATS-E in the prone position is lesser invasive and faster recovery than in the left lateral position. Disclosure All authors have declared no conflicts of interest. [ABSTRACT FROM AUTHOR]
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- 2018
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14. New Concept Air Conditioning System for the Operating Room to Minimize Patient Cooling and Surgeon Heating: A Historical Control Cohort Study.
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Usuki, Hisashi, Kitamura, Hiroaki, Ando, Yasuhisa, Suto, Hironobu, Asano, Eisuke, Ohshima, Minoru, Kishino, Takayoshi, Kumamoto, Kensuke, Okano, Keiichi, and Suzuki, Yasuyuki
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HEATING control , *OPERATING rooms , *TEMPERATURE control , *LAPAROSCOPIC surgery , *COHORT analysis , *INDUCED hypothermia - Abstract
Background: Intraoperative hypothermia is a common adverse event. For avoiding the complication due to hypothermia, many warming devices and methods have been used in perioperative period. It has been reported that more patients undergoing laparoscopic surgery tend to have hypothermia than with open surgery. To avoid intraoperative hypothermia, many kinds of warming tools have been used. But, it was also reported that some warming methods increased perceptions of distraction and physical demand. Methods: To achieve both patients' normothermia and surgeons' comfort, new air conditioning (AC) system was designed with considering the characteristics of laparoscopic surgery. The temperature of the airflows to the patient and to the surgeons can be adjusted independently in this new system. The new system has two parts. One controls the temperature of the central area over the operation table. The air from this part falls on the patients. The other part is the lateral area beside the operating table; the air from this part falls on the surgeons. The subjects of this study were 160 gastric cancer patients and 316 colorectal cancer patients undergoing laparoscopic surgery. The temperature of the central flow was set 23.5 °C, and the temperature of the lateral flow was set 22 °C just after the anesthesia. The number of timepoints the patient spent in hypothermic state, defined as a temperature cooler by 0.5 °C or more than that at the starting point of surgery, was determined in each patient. Results: In the results, the rate of hypothermic state in old operation rooms was 23.8% and that in new operation rooms was 2.7% in male gastric cancer patients (p < 0.01). And those were 37.1% in old operation rooms and 0.9% in new operation rooms in female gastric cancer patients (p < 0.01). The rate of hypothermic state in old operation rooms was 30.0% and that in new operation rooms was 9.5% in male colorectal cancer patients (p < 0.01). And those were 41.6% in old operation rooms and 8.9% in new operation rooms in female colorectal cancer patients (p < 0.01). The similar results were showed in the study, which subjects were limited the patients undergoing surgery in 2015 and 2016; which were the last year the old operation rooms were used and the first year the new operation rooms were used. Conclusions: Thus, the usefulness of the new air conditioning system for achieving both patients' normothermia and comfort of surgeons could be verified in this study. [ABSTRACT FROM AUTHOR]
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- 2020
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15. Internal hernia after laparoscopic sigmoidectomy with splenic flexural mobilization and high ligation of the inferior mesenteric vein: A case report.
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Feng, Dongping, Kondo, Akihiro, Asano, Eisuke, Matsukawa, Hiroyuki, Nishiura, Bumpei, Ando, Yasuhisa, Suto, Hironobu, Kishino, Takayoshi, Oshima, Minoru, Kumamoto, Kensuke, and Okano, Keiichi
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MESENTERIC veins , *HERNIA , *LAPAROSCOPIC surgery , *PROCTOLOGY , *SMALL intestine , *INGUINAL hernia - Abstract
Several studies have recently reported the rare occurrence of internal herniation of the small bowel after laparoscopic colorectal surgery. Most cases of internal herniation after laparoscopic colorectal surgery occur due to a mesenteric defect. However, there have been no reports on the indications for closing mesenteric defects to prevent the development of an internal hernia. This study reports a case of an internal hernia of the proximal jejunum near the ligament of Treitz in a patient who underwent laparoscopic sigmoidectomy with splenic flexural mobilization and high ligation of the inferior mesenteric vein. Assessing the risk for internal herniation before completing the initial surgery is crucial. Additionally, mesenteric defect closure should be performed to prevent the development of internal hernias among patients with a potential risk. [ABSTRACT FROM AUTHOR]
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- 2023
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16. Comparison of Needle Knife versus Scissors Forceps for Colorectal Endoscopic Submucosal Dissection: A Prospective Randomized Study.
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Yachida, Tatsuo, Kobara, Hideki, Kozuka, Kazuhiro, Nakatani, Kaho, Tada, Naoya, Matsui, Takanori, Chiyo, Taiga, Kobayashi, Nobuya, Fujihara, Shintaro, Nishiyama, Noriko, Kondo, Akihiro, Ando, Yasuhisa, Okano, Keiichi, Nonaka, Wakako, Ishikawa, Kaori, Masugata, Hisashi, and Masaki, Tsutomu
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LONGITUDINAL method , *FORCEPS , *KNIVES , *SURGICAL complications , *DISSECTION , *NEEDLES & pins - Abstract
Background and Aim: To evaluate the efficacy and safety of a grasping-type knife, called Clutch Cutter (CC), for colorectal endoscopic submucosal dissection (C-ESD). Methods: This was a randomized prospective study. Patients who underwent C-ESD for colorectal neoplasms >20 mm and <50 mm in size were enrolled, dividing into two groups: ESD using needle type of dual knife alone (D-group) and circumferential incision using dual knife followed by submucosal dissection using CC (CC-group). The primary outcome was the self-completion rate. The secondary outcomes were intraoperative complication rate, procedure time, and en bloc resection rate. Results: A total of 45 patients were allocated to the D-group and 43 to the CC-group were allocated. The self-completion rate was higher in the CC-group (87% [39/45] vs. 98% [42/43]). All of the six patients with an incomplete procedure in the D-group were completely resected with CC use. The intraoperative complication rate was not significant in either group (D vs. CC: 2% vs. 0%). The mean procedure time was significantly shorter in the D-group than that in the CC-group (62.0 vs. 81.1 min; p = 0.0036). The en bloc resection rate was 100% in the D-group and 98% in the CC-group. Conclusions: While dual knife use is superior to CC in terms of time efficiency, the use of CC may be a safe and efficacious option for achieving complete C-ESD. [ABSTRACT FROM AUTHOR]
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- 2023
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17. Role of Short-Term Neoadjuvant Chemoradiotherapy for Potentially Resectable Pancreatic Cancer.
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Okano, Keiichi, Suto, Hironobu, Oshima, Minoru, Ando, Yasuhisa, Matsukawa, Hiroyuki, Kamada, Hideki, Kobara, Hideki, Masaki, Tsutomu, and Suzuki, Yasuyuki
- Abstract
Although the efficacy of neoadjuvant therapies for pancreatic cancer (PDAC) is reported in recent years, ideal neoadjuvant treatment for patients with potentially resectable (R) PDAC remains uncertain. We conducted the retrospective study about the effect of short-term neoadjuvant chemoradiotherapy (sNACRT) on R PDAC. The 94 patients received curative intent pancreatectomy for R PDAC between 2000 and 2016. Among them, 31 patients received sNACRT (S1 60 mg/m2/day for 2w and RTx 30 Gy/2w). Clinical outcomes of the 31 patients with sNACRT were analyzed in comparison with 63 patients without sNACRT. The 1-, 3-, and 5-year overall survival (OS) rates were 93, 71, and 62% in the patients with sNACRT and 78, 35, and 26% in the patients without sNACRT (P = .0007), respectively. Lymph node metastasis was found in 41.9% of patients with sNACRT and 56.5% of patients without sNACRT (P = .09). Microscopic tumor infiltration at resection margins (R1) was found in no patient with sNACRT and 5 patients (7.9%) without sNACRT (P=.042). Retropancreatic infiltration (P = .04), lymphatic invasion (P = .002), plexus invasion (P = .042), and main pancreatic duct extension (P = .004) were significantly fewer in patients with sNACRT than the patients without sNACRT. The recurrences were found in 64% of patients with sNACRT (39% distant, 16% local, and 10% mix pattern) and 68% in patients without sNACRT (28% distant, 21% local, and 19% mix pattern). The recurrence patterns were significantly different (P = .008) between the groups. Short-term neoadjuvant chemoradiotherapy decreased R1 resection rate and improved OS. Short-term neoadjuvant chemoradiotherapy may provide ideal local control during the short term and improve clinical outcome of R PDAC. [ABSTRACT FROM AUTHOR]
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- 2022
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18. Ampullary carcinoma of the duodenum: current clinical issues and genomic overview.
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Okano, Keiichi, Oshima, Minoru, Suto, Hironobu, Ando, Yasuhisa, Asano, Eisuke, Kamada, Hideki, Kobara, Hideki, Masaki, Tsutomu, and Suzuki, Yasuyuki
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DUODENUM , *PROGNOSIS , *INDIVIDUALIZED medicine , *GENETIC mutation , *PANCREATIC tumors ,BILIARY tract cancer - Abstract
Ampullary carcinomas of the duodenum are uncommon. Moreover, the diversity in the clinical outcomes of these patients makes it difficult to interpret previous studies and clinical trial results. The difficulty in proper staging of ampullary carcinomas, especially with regard to the T category of the tumor in the TNM system, reflects the anatomic complexity and non-uniform histopathologic subtypes. One major reason for this difficulty in interpretation is that the tumors may arise from any of the three epithelia (duodenal, biliary, or pancreatic) that converge at this location. Generally, ampullary carcinomas are classified into intestinal and pancreaticobiliary types based on morphology and immunohistochemical features. While many studies have described their specific characteristics and clinical impact, the prognostic value of these subtypes is controversial. In recent years, whole-exome sequencing analyses have advanced our understanding of the genomic overview of ampullary carcinoma. Gene mutations serve as prognostic and predictive biomarkers for this disease. Therefore, basic knowledge of the genomic profile of ampullary carcinomas is required for surgeons to understand how best to apply precision medicine as well as surgery and adjuvant therapies. This review provides an overview of the current basic and clinical issues of ampullary carcinoma. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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19. Changes and prognostic impact of inflammatory nutritional factors during neoadjuvant chemoradiotherapy for patients with resectable and borderline resectable pancreatic cancer.
- Author
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Oshima, Minoru, Okano, Keiichi, Suto, Hironobu, Ando, Yasuhisa, Kamada, Hideki, Masaki, Tsutomu, Takahashi, Shigeo, Shibata, Toru, and Suzuki, Yasuyuki
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PANCREATIC cancer , *PROGNOSIS , *CHEMORADIOTHERAPY , *RECTAL cancer , *C-reactive protein , *GLASGOW Coma Scale , *PANCREATIC tumors , *RETROSPECTIVE studies , *DUCTAL carcinoma , *PANCREATECTOMY , *COMBINED modality therapy - Abstract
Background: Inflammatory nutritional factors, such as the neutrophil/lymphocyte ratio (NLR), Glasgow Prognostic Score (GPS), modified GPS (mGPS), and C-reactive protein/albumin (CRP/Alb) ratio, have prognostic values in many types of cancer. In this study, the prognostic values of inflammatory nutritional scores were evaluated in the patients with resectable or borderline resectable pancreatic ductal adenocarcinoma (PDAC) after neoadjuvant chemoradiotherapy (NACRT).Methods: A total of 49 patients who underwent pancreatectomy after NACRT from September 2009 to May 2016 were enrolled. The NACRT consisted of hypofractionated external-beam radiotherapy (30 Gy in 10 fractions) with concurrent S-1 (60 mg/m2) delivered 5 days/week for 2 weeks before pancreatectomy. Inflammatory nutritional scores were determined before and after NACRT in this series.Results: The median NLR increased after NACRT (from 2.067 to 3.302), with statistical difference (p < 0.001). In multivariate analysis, high pre-NACRT mGPS (2 or 1; p = 0.0478) and significant increase in CRP/Alb ratio after NACRT (≧ 0.077; p = 0.0036) were associated with shorter overall survival. All patients were divided into two groups according to the ΔCRP/Alb ratio after NACRT: the group with high ΔCRP/Alb ratio (≧ 0.077) and the group with low ΔCRP/Alb ratio (< 0.077). The group with high ΔCRP/Alb ratio after NACRT (n = 13) not only had higher post-NACRT CRP levels (p < 0.001) but also had lower post-NACRT Alb levels (p = 0.002). Patients in the group with high ΔCRP/Alb ratio lost more body weight during NACRT (p = 0.03).Conclusion: In addition to pre-NACRT mGPS, ΔCRP/Alb after NACRT could provide prognostic value in the patients with PDAC treated by NACRT. [ABSTRACT FROM AUTHOR]- Published
- 2020
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20. Formation of a stable, three-dimensional porous structure with self-assembled glass spheres using the plasma-induced electromeniscus phenomenon.
- Author
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Matsuura, Hiroshi, Tanikawa, Tamio, Ando, Yasuhisa, Miyake, Koji, and Sasaki, Shinya
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POROUS materials , *GLASS , *SPHERES , *SURFACE tension , *CATALYSTS , *HYDROGEN - Abstract
We develop a method for fabricating a stable, three-dimensional porous structure with self-assembled glass spheres. This three-dimensional (3D) self-assembly of glass spheres is achieved using the electromeniscus phenomenon, which is associated with a microscale solution current. The current encloses a group of glass spheres, carries the spheres, and assembles them three dimensionally with its surface tension at the desired site. The assembled glass spheres are fixed using a plasma-induced reaction combined with thermal treatment of the solution. These assembled microscale spheres create a large number of openings with extensive surface areas. This extensive area among 3D porous structures would be particularly useful for fabricating high-performance catalysts and high-resolution hydrogen sensors. [ABSTRACT FROM AUTHOR]
- Published
- 2006
- Full Text
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21. Pure laparoscopic pancreas parenchymal dissection using CUSA for distal pancreatectomy.
- Author
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Okano, Keiichi, Suto, Hironobu, Oshima, Minoru, Ando, Yasuhisa, Asano, Eisuke, Kishino, Takayoshi, Fujiwara, Masao, Kobara, Hideki, Mori, Hirohito, Masaki, Tsutomu, and Suzuki, Yasuyuki
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ALLERGIES , *LAPAROSCOPIC surgery , *PANCREATECTOMY , *OPERATIVE surgery , *TITANIUM - Abstract
Although stapler dissection and closure is commonly used for laparoscopic distal pancreatectomy (LDP), it is risky in patients with thick pancreatic parenchyma or titanium allergy. We performed laparoscopic pancreatic parenchymal dissection with cavitron ultrasonic surgical aspirator (CUSA) successfully in a patient with titanium allergy. Slinging the pancreas with nylon tape delineates the surgical plane. Pancreatic parenchyma was transected by CUSA in an almost bloodless field. Pancreatic duct branches and vessels were adequately exposed and dissected with a vessel sealing system. The main pancreatic duct was closed with Hem-O-lock. CUSA is an alternative to stapler dissection during LDP in select patients. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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- View/download PDF
22. Hepatectomy Based on Future Liver Remnant Plasma Clearance Rate of Indocyanine Green.
- Author
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Uchida, Yuichiro, Furuyama, Hiroaki, Yasukawa, Daiki, Nishino, Hiroto, Ando, Yasuhisa, Hata, Toshiyuki, Machimoto, Takafumi, and Yoshimura, Tsunehiro
- Subjects
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HEPATECTOMY , *INDOCYANINE green , *LIVER disease treatment , *DEATH rate , *LIVER radiography , *COMPUTED tomography - Abstract
Background. Hepatectomy, an important treatment modality for liver malignancies, has high perioperative morbidity and mortality rates. Safe, comprehensive criteria for selecting patients for hepatectomy are needed. Since June 2011, we have used a cut-off value of ≧ 0.05 for future liver remnant plasma clearance rate of indocyanine green as a criterion for hepatectomy. The aim of this study was to verify the validity of this criterion. Methods. From June 2011 to December 2015, 212 hepatectomies were performed in Tenri Yorozu Hospital. Of these 212 patients, 107 who underwent preoperative computed tomography imaging volumetry, indocyanine green clearance test, and hepatectomy (excluding partial resection or enucleation) were retrospectively analyzed. Results. There was no postoperative mortality. Posthepatectomy liver failure occurred in 59 patients (55.1%) (International Study Group of Liver Surgery Grade A: 43 cases (40.2%), Grade B: 16 cases (15.0%), and Grade C: no cases). Operative morbidity greater than Clavien-Dindo Grade 3 occurred in 23 patients (21.5%). A low future liver remnant plasma clearance rate of indocyanine green was a good predictor for Grade B cases (area under curve = 0.804; 95% confidence interval, 0.712–0.895). Conclusion. Liver remnant plasma clearance rate of indocyanine green is a valid criterion for hepatectomy. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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23. Tribological properties of self-assembled monolayers covalently bonded to Si
- Author
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Nakano, Miki, Ishida, Takao, Sano, Hikaru, Sugimura, Hiroyuki, Miyake, Koji, Ando, Yasuhisa, and Sasaki, Shinya
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TRIBOLOGY , *MOLECULAR self-assembly , *MONOMOLECULAR films , *CHEMICAL bonds , *SILICON , *MECHANICAL wear , *SILICON carbide , *PREVENTION - Abstract
Abstract: The frictional properties of self-assembled monolayers (SAMs) covalently bonded to silicon (Si) substrates through Si–C or Si–O–C bonds were investigated using a pin-on-plate tribometer. Four kinds of molecules with different alkyl chain lengths and different head groups were used: 1-hexadecene, 1-hexadecanol, 1-dodecene and 1-dodecanol. The SAMs with longer alkyl chains exhibited lower friction coefficients than those with shorter alkyl chains. Of the SAMs with longer alkyl chains, the SAMs with the Si–C bond of the head group exhibited lower friction coefficients, higher wear resistance and higher durability than those with the Si–O–C bond. The head group and alkyl chain length of the molecules affected the frictional properties of the modified surfaces of the SAMs. [Copyright &y& Elsevier]
- Published
- 2008
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24. Tribological behavior of self-assembled double layer measured by a pin-on-plate method
- Author
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Nakano, Miki, Ishida, Takao, Numata, Toshimitsu, Ando, Yasuhisa, and Sasaki, Shinya
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INTERMEDIATES (Chemistry) , *TRIBOLOGY , *PHOTOELECTRON spectroscopy , *SPECTRUM analysis - Abstract
Abstract: We investigated the frictional properties and the durability of self-assembled double layers using pin-on-plate methods and X-ray photoelectron spectroscopy (XPS). We found that double layers made from octadecanethiol (ODT) and mercaptohexadecanoic acid (MHA) connected via Cu ions exhibited lower frictional coefficients (approximately 0.1–0.15) than that of ODT monolayer (∼0.2). XPS measurements revealed that ratios of C(1s)/Au(4f) after friction tests were lower than that before friction but was higher than that measured on ODT monolayer, suggesting that some of ODT molecules were desorbed from the surface, i.e. formation of loosely packing molecular layers after friction. These findings suggest that the loosely packed molecular layer contributed to decrease the friction. [Copyright &y& Elsevier]
- Published
- 2005
- Full Text
- View/download PDF
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