56 results on '"Yasuhiro Yamada"'
Search Results
2. Chemoselective vapor-phase hydrogenation of 6-methyl-5-hepten-2-one over Cu/SiO2 catalyst prepared by organic additive-assisted impregnation.
- Author
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Enggah Kurniawan, Kenta Matsusaka, Koki Sato, Shun Sasaki, Kazuki Nakazono, Yasuhiro Yamada, and Satoshi Sato
- Published
- 2024
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3. Complementary role of Indocyanine green video angiography, dual-image video angiography and flow-800.
- Author
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Khasanov, Khabibullo A., Alikhodjayeva, Gulnara A., Yasuhiro Yamada, Yoko Kato, Yakubov, Jakhongir B., Yağmurlu, Kaan, and Chaurasia, Bipin
- Subjects
INDOCYANINE green ,ANGIOGRAPHY ,INTRACRANIAL aneurysms ,CAROTID endarterectomy ,HUMAN anatomy ,BLOOD flow ,ENDARTERECTOMY - Abstract
Background: Visualization of cerebral vessels, their branches and the surrounding structures are essential during cerebrovascular surgery. Indocyanine green dye-based video angiography is a commonly used technique in cerebrovascular surgery. This paper aims to analyze the real-time imaging of ICG-AG, DIVA, and the use of ICG-VA with Flow 800 to compare their usefulness in surgery. Methods: Intraoperative real-time identification of vascular and surrounding structures in twenty nine anterior circulation aneurysms and three posterior circulation aneurysm clipping, one STA-MCA bypass, and two carotid endarterectomies were performed in patients using ICG-VA alone, DIVA, ICG-VA with Flow 800 to analyze and compare each of these methods in details. Results: ICG-VA and DIVA couldn't visualize perforators in twenty-three cases of cerebral aneurysms clipping when used alone. Compared to that by adding Flow 800 perforators were easily visualized. In three cases, occlusion of perforators after clip application was visualized by DIVA and solved by repositioning surgical clips. In one STA-MCA bypass surgery, adequate blood flow to cortical branches of MCA (M4) from STA branches was assessed with ICG-VA, DIVA, and the use of ICG-VA with Flow 800 color mapping. ICG-VA, DIVA, and Flow 800 observed the lack of blood flow and fluttering atherosclerotic plaques in carotid endarterectomy. In one case of basilar tip aneurysm, we used ICG-VA with Flow 800; the intensity diagram drawn after determining regions of interest showed that there was no flow within the aneurysm sac after clipping. Conclusion: In real-time surgery, a multimodal approach using ICG-VA, DIVA, and ICG-VA with Flow 800 colour mapping can serve as useful tools for better visualization of vascular and surrounding structures. The benefits of flow 800 color mapping, such as determining regions of interest, intensity diagrams, and color-coded images, outweigh the advantages over the ICG-VA and DIVA in the visualization of critical vascular anatomy in humans during surgical procedures. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
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4. Archaeological and anthropological views of Jomon society: methods and practices.
- Author
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Yasuhiro Yamada
- Published
- 2022
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5. Strontium isotope analysis on human skeletal remains from the Hobi and Ikawazu shell-mounds in Aichi Prefecture, Japan.
- Author
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Soichiro Kusaka, Tsutomu Saito, Eriko Ishimaru, and Yasuhiro Yamada
- Published
- 2022
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6. Ritual tooth ablation in and dentometric assessment of a newly discovered collective burial at the Hobi shell-mound site, Aichi Prefecture, Japan.
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Osamu Kondo, Soichiro Mizushima, Nobuo Shigehara, and Yasuhiro Yamada
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- 2022
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7. Newly discovered banjo-shuseki-bo (square-shaped bone-pile burial) human bones from the Final Jomon Period Hobi shell-mound site, Aichi Prefecture, Japan .
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Soichiro Mizushima, Osamu Kondo, Nobuo Shigehara, and Yasuhiro Yamada
- Published
- 2022
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8. Complete mitochondrial genome sequencing reveals double-buried Jomon individuals excavated from the Ikawazu shell-mound site were not in a mother–child relationship.
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Daisuke Waku, Takashi Gakuhari, Kae Koganebuchi, Minoru Yoneda, Osamu Kondo, Tadayuki Masuyama, Yasuhiro Yamada, and Hiroki Oota
- Published
- 2022
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9. High‑Flow Bypass with Radial Artery Graft for Cavernous Carotid Aneurysms: A Case Series.
- Author
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Riki Tanaka, Boon Seng Liew, Kento Sasaki, Kyosuke Miyatani, Tsukasa Kawase, Yasuhiro Yamada, Yoko Kato, and Akihiko Horiguchi
- Subjects
RADIAL artery ,CEREBRAL revascularization ,ANEURYSMS ,ARTERIAL occlusions ,INTRACRANIAL aneurysms ,ENDOVASCULAR surgery ,ANGIOMAS ,INTRACRANIAL arterial diseases - Abstract
Background: The incidence of cavernous carotid aneurysms (CCAs) of intracranial aneurysms is low. Majority of cases presented as incidental findings with benign natural progression. The most common presenting symptoms are multiple cranial neuropathies among symptomatic patients. The treatment modalities for symptomatic patients include direct surgical clipping, endovascular coil embolization, or placement of flow diverter, or indirect procedures such as occlusion of parent artery with and without revascularization techniques. The advancement in the microsurgical treatments and endovascular devices have enable a high success rate in the treatment of patients with CCAs with low morbidity and mortality rates. Objective: To study the surgical outcomes of patients with cavernous aneurysm who underwent high‑flow bypass between 2015 and 2020 in our institution. Materials and Methods: A total of six patients in a single institution presented with CCAs who were treated with high‑flow bypass surgery were included in this case-series. A single‑case illustration was presented focusing on the details of surgical case management of CCA. The intraoperative middle cerebral artery (MCA) pressure monitoring during bypass surgery was also described. Results: All five female patients and one male patient who were diagnosed with cavernous carotid aneurysms were studied. The mean age was 68.8 years old (range: 24-84 years old) and the mean size of the aneurysm was 19.6mm (range: 9.7 – 30mm). There were successfully treated with high flow bypasses using radial artery graft without any neurological sequelae. Conclusion: The surgical treatments of cavernous carotid aneurysms should be limited to experienced neurosurgeons in view of significant risk of morbidity and mortality. Endovascular procedures may be the main stay of treatments. The success shown in this case series with parent artery occlusion and bypass surgery may provide an safe alternative to the endovascular treatment. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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10. Endoscopic Microvascular Decompression for Hemifacial Spasm.
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Matmusaev, Maruf, Kumar, R. Senthil, Yasuhiro Yamada, Tetsuya Nagatani, Tsukasa Kawase, Tanaka, Riki, Miyatani Kyosuke, and Yoko Kato
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MAGNETIC resonance imaging ,COMPUTED tomography ,SPASMS ,THREE-dimensional imaging ,FACIAL nerve ,ENDOSCOPIC surgery ,NEUROLOGIC examination - Abstract
Introduction and Objective: Hemifacial spasm (HFS) is a condition, characterized by painless, involuntary unilateral tonic or clonic contractions of the facial muscles innervated by the ipsilateral facial nerve. HFS starts with contractions in the orbicularis oculi muscle with subsequent eyelid closure and/or eyebrow elevation, but may spread to involve muscles of the frontalis, platysma, and orbicularis oris muscles. Microvascular decompression (MVD) is reliable and accepted surgical treatment for HFS. MVD is the standard surgical technique now for HFS treatment with long‑term success rates. Materials and Methods: We performed fully endoscopic MVD technique for 1 patient with HFS (a 83‑year‑old female) at our institution. HFS was diagnosed based on the clinical history and presentation, a neurologic examination, and additional imaging findings. Respectively, the durations of HFS were 3 years, respectively. The patient had been previously treated with repeated botulinum toxin injections. Preoperative evaluation was done with magnetic resonance imaging; three‑dimensional computed tomography fusion images examinations had identified the anterior inferior cerebellar artery (AICA) as the offending vessel in this patient. Results: The patient with HFS was treated by fully endoscopic MVD technique. The AICA, which had been identified as the offending vessel by preoperative magnetic resonance imaging, was successfully decompressed. No surgery‑related complications occurred and had excellent outcomes with the complete resolution of HFS immediately after the operation. Conclusions: Endoscopic surgery can provide a more panoramic surgical view than conventional microscopic surgery. Fully endoscopic MVD is both safe and effective in the treatment of HFS. This method minimizes the risks of brain retraction and extensive dissection often required for microscopic exposure. Endoscopic MVD is safe and has advantage over microscope in terms of visualization of structure, identification of neurovascular conflict, but it has a learning curve and technically challenging. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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11. Band-Edge Luminescence from Oxide and Halide Perovskite Semiconductors.
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Yoshihiko Kanemitsu and Yasuhiro Yamada
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OPTOELECTRONIC devices ,LUMINESCENCE ,HALIDES ,SEMICONDUCTORS ,OPTICAL properties - Abstract
Because perovskite crystals exhibit unique magnetic, conductive, and optical properties, they have been the subject of many fundamental investigations in various research fields. However, investigations related to their use as optoelectronic device materials are still in their early days. Regarding oxide perovskites, which have been investigated for a long time, the efficiency of photoluminescence (PL) induced by band-to-band transitions is extremely low because of the localized nature of the carriers in these materials. On the other hand, halide perovskites exhibit a highly efficient band-edge PL attributable to the recombination of delocalized photocarriers. Therefore, it is expected that this class of high-quality materials will be advantageous for optoelectronic devices such as solar cells and lightemitting diodes. In this Minireview, we discuss various aspects of the PL properties and carrier dynamics of SrTiO
3 and CH3 NH3 PbX3 (X=I, Br), which are representative oxide and halide perovskites. [ABSTRACT FROM AUTHOR]- Published
- 2020
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12. Small bowel perforation caused by applicator implantation in high-dose-rate interstitial brachytherapy for recurrent pelvic tumor: a case report.
- Author
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Koji Masui, Hideya Yamazaki, Gen Suzuki, Daisuke Shimizu, Tadashi Takenaka, Yasuhiro Yamada, Koji Okihara, Yoshiaki Kuriu, and Kei Yamada
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INTERSTITIAL brachytherapy ,SMALL intestine ,TUMORS ,INTESTINAL perforation ,TUMOR treatment ,BOWEL obstructions - Abstract
High-dose-rate interstitial brachytherapy (HDR-ISBT) is widely used for the treatment of pelvic tumors. However, there are a few reports on complications of applicator implantation in HDR-ISBT. We describe a case of small bowel perforation caused by applicator implantation in an 82-year-old male patient with recurrence tumor in the pelvis treated with HDR-ISBT. Eventually, the patient underwent laparotomy and partial intestinal resection. We recognized the site where the applicator was inserted into a part of the tumor on the mucosal surface. Pathological examination confirmed that the tumor had infiltrated the small intestine directly and that the infiltrated part had reached the submucosa. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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13. Surgical management of unruptured cerebral aneurysms in the elderly: An institution experience.
- Author
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Cheikh, Abderrahmane, Kasinathan, Sudhakar, Yasuhiro, Yamada, Kawase, Tsukasa, and Kato, Yoko
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INTRACRANIAL aneurysm surgery ,INTRACRANIAL aneurysms ,OLDER people ,DEVELOPED countries - Abstract
Background and Purpose: The elderly population is increasing in the world, especially in developed countries. The gain in life expectancy is remarkable in Japan, consequently incidence of aneurysms increases in this population. The purpose of this study is to evaluate the surgical treatment and outcome of patients aged more than 75 years treated for unruptured intracranial aneurysms. Patients and Methods: We conducted a retrospective study for unruptured cerebral aneurysms operated between September 2014 and August 31, 2018, in Fujita Health University, Banbuntane Hotokukai Hospital, for people aged more than 75 years. A demographic study was done. We also studied aneurysm location, aneurysm size, outcome, duration of stay, and complications. Results: About 61 patients aged more than 75 years were operated in 4 years, comprising 12 males and 45 females. The mean age was 79.32 ± 3.29 years. Mean size of the aneurysm was 6.22 ± 3.28. Aneurysm location (P = 0.0037), associated risk factors (P = 0.006), and association of hypertension and diabetes (P = 0.0362) influence outcome. Length of stay is directly correlated with outcome (P = 0.009). Conclusions: Elder patients with hypertension and diabetes or associated risk factors having a posterior circulation aneurysm have a poor diagnosis. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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14. Superficial temporal artery: Middle cerebral artery bypass, our series of 20 cases, surgical technique and indications with illustrative cases.
- Author
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Cheikh, Abderrahmane, Yasuhiro, Yamada, Kasinathan, Sudhakar, Kawase, Tsukasa, Takao, Teranishi, and Kato, Yoko
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CEREBRAL revascularization ,TEMPORAL arteries ,CEREBRAL arteries ,SURGICAL indications ,OPERATIVE surgery - Abstract
The first extracranial-intracranial (EC-IC) bypass surgery was performed by professor Yasargil in 1967 since then this procedure has been widely used in vascular neurosurgery and sometimes, in tumors excision when a vascular sacrifice is necessary. In this article, we will illustrate the surgical technique of the superficial temporal artery-middle cerebral artery (STA-MCA) bypass with two cases; a 59-year-old male and 64-year-old female who presented with an occlusion of the MCA. The male presented also with a posterior communicating artery-IC aneurysm which was clipped in the same sitting. We also studied in this paper a series of 20 patients operated in Banbuntane Hotokukai Hospital, Fujita Health University, for which a low-flow STA-MCA anastomosis was done for steno-occlusive disease or moyamoya disease. In Banbuntane Hotokukai Hospital, Fujita Health University, 20 patients were operated since 2015, 12 patients were male. Five patients presented with moyamoya disease, while 15 patients presented with vascular steno-occlusive disease. The steno-occlusion was found in internal carotid artery in nine patients. The patients were divided into two categories (steno-occlusive disease and moyamoya). STA-MCA bypass is now one of the basic techniques to master in vascular neurosurgery. It requires to perform the anastomosis correctly within the permissible time. The goal is to have a long-term patency for the anastomosed vessel. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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15. Outcome analysis of surgical clipping for incidental internal carotid posterior communicating and anterior choroidal artery aneurysms.
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Mohammad, Ameen, Yasuhiro, Yamada, Seng, Liew, Rajagopal, Niranjana, and Yoko, Kato
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CHOROID ,CAROTID artery ,ANEURYSMS ,HEMIPARESIS ,ARTERIES ,SURGICAL complications ,DISEASE complications - Abstract
Introduction: Surgical outcome and ischemic complications of Internal carotid Posterior Communicating (IC PC) and anterior choroidal aneurysms have been questionable due to frequent occlusion of the anterior choroid artery and also due to low incidence of true anterior choroid artery aneurysms. The present series describes the postoperative outcome after clipping of such aneurysms at a single centre. Methods: A retrospective analysis of 73 cases with IC PC and Anterior choroidal aneurysms performed at a Fujita Health University, Banbuntane Hotokukai Hospital, Nagoya, Aichi, Japan from 2014 to 2018 have been studied and emphasis is made on the demography and ischemic complications. Results: A total of 73 patients with IC PC and anterior choroidal aneurysms were studied, out of which 57 patient had a true IC PC aneurysm, 14 patients had aneurysms involving the anterior choroidal artery and only 2 patients had aneurysms which involved both the IC PC and the anterior choroidal arteries. None of the patients had a permanent Anterior Choroidal Artery syndrome, whereas only 2 out of the 73 patients had postoperative complications in the form of transient hemiparesis. Conclusion: Ischemic complications following surgical clipping of IC PC and anterior choroidal aneurysms can be minimised by meticulous micro dissection to identify the anterior choroidal artery thus preserving the patency of the same. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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16. Multisystem Inflammatory Syndrome in Adults after Mild SARS-CoV-2 Infection, Japan.
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Yasuhiro Yamada, Kaoru Fujinami, Tadashi Eguchi, Hiroshi Takefuji, Nobuaki Mori, Yamada, Yasuhiro, Fujinami, Kaoru, Eguchi, Tadashi, Takefuji, Hiroshi, and Mori, Nobuaki
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SARS-CoV-2 ,MUCOCUTANEOUS lymph node syndrome ,MULTISYSTEM inflammatory syndrome - Abstract
In Japan, a 51-year-old man had minimally symptomatic severe acute respiratory syndrome coronavirus 2 infection. Multisystem inflammatory syndrome was diagnosed ≈5 weeks later; characteristics included severe inflammation, cardiac dysfunction, and IgG positivity. Clinicians should obtain detailed history and examine IgG levels for cases of inflammatory disease with unexplained cardiac decompensation. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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17. Loss of contralateral upper limb motor evoked potential due to occlusion of the internal carotid artery in microsurgical clipping of basilar tip aneurysm.
- Author
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Seng, Liew, Yasuhiro, Yamada, Rajagopal, Niranjana, Mohammad, Ameen, Takao, Teranishi, Kyosuke, Miyatani, Tsukasa, Kawase, and Kato, Yoko
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INTERNAL carotid artery ,ARM ,OCULOMOTOR nerve ,CEREBRAL arteries ,ANEURYSMS ,COMA ,CEREBRAL angiography ,TEMPORAL lobectomy - Abstract
The motor evoked potential (MEP) monitoring is routinely used as an adjunct in the microsurgical clipping of anterior circulation. We describe a case of unruptured basilar tip aneurysm treated with microsurgical clipping developed loss in MEP recording of the left abductor pollicis brevis (APB) following clipping of basilar tip aneurysm. A 58-year-old man was referred to the Fujita Health University Banbuntane-Hotokukai Hospital, Nagoya, Aichi, Japan, with incidental finding of unruptured 6.5 mm basilar tip saccular aneurysm. He underwent right anterior temporal approach of basilar tip aneurysm clipping. The internal carotid artery (ICA) was mobilized laterally to allow direct visualization of the neck of the basilar tip aneurysm. Following the application of temporary clip and subsequently permanent clip at the neck of the aneurysm, the MEP signal was lost in the left APB. The temporary clip was immediately removed. Dual-image videoangiography (DIVA) showed a filling defect in the right ICA and a branch of middle cerebral artery (MCA). The MEP was absent for about 23 minutes and the amplitude improved to only 75% of the baseline recording at 38 minutes till the end of the surgery. A repeat DIVA showed good flow within the right ICA and MCA. Glasgow coma score was 15/15 on postoperative day 1 and there was no gross motor or sensory deficit except right oculomotor nerve palsy with complete recovery at 6 months follow-up. This is the first reported ICA occlusion due to its mobilization in microsurgical clipping of basilar tip aneurysm. The use of neuromonitoring especially MEP is essential even in the posterior circulation aneurysm surgery especially when excessive manipulation of the ICA is unavoidable. When performing intraoperative angiography for aneurysm surgery, it is prudent to detect any filling defect within the surrounding vessels. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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18. Computational fluid dynamics as an indicator of offending vessel in trigeminal neuralgia and hemifacial spasms.
- Author
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V., Mayur Kamath, Yasuhiro Yamada, and Yoko Kato
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COMPUTATIONAL fluid dynamics ,TRIGEMINAL neuralgia ,MICROCIRCULATION disorders ,COMPUTED tomography ,SHEARING force - Abstract
Context: Newer Imaging tool for diagnosing offending vessel in trigeminal neuralgia (TN) and Hemifacial spasms (HFS). Aim: To find out if Computational FluidDynamics (CFD) can correctly predict the offending vessel in HFS and TN & thus improving the outcome of Microvascular Decompression) MVD. Settings and Design: CFD is a relatively new mode of imaging. Its application to indicate offending vessel in TN & HFS was tested. Materials & Methods: Retrospectively we studied 13 consecutive patients operated in 2017 for either HFS or TN. Preoperatively MRI & Computed Tomography Angiogram (CTA) were done and the offending vessel identified along with its point of contact with the concerned nerve. CFD was done using Hemoscope 2015 software and wall pressure, wall shear stress, vector & streamline flow were obtained in the offending vessel (test) & contralateral vessel (control). Results of these were charted on an excel sheet & results analyzed. The postoperativeoutcome were assessed and compared with CFD results. Statistical analysis used: Small study group hence statistical analysis couldn't be applied. Results: Of the 13 patients, offending artery had high wall pressure in 12 and increased wall shear stress innine. Among the controls six had high wall pressure and only two had high wall shear stress. Conclusion: CFD can be used to determine offending vessel and can predict good outcome following microvascular decompression. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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19. Computational fluid dynamics as an indicator of offending vessel in trigeminal neuralgia and hemifacial spasms.
- Author
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V., Mayur Kamath, Yasuhiro Yamada, and Yoko Kato
- Subjects
COMPUTATIONAL fluid dynamics ,TRIGEMINAL neuralgia ,MICROCIRCULATION disorders ,COMPUTED tomography ,MAGNETIC resonance imaging ,STATISTICS ,PATIENTS - Abstract
Context: Newer Imaging tool for diagnosing offending vessel in trigeminal neuralgia (TN) and Hemifacial spasms (HFS). Aim: To find out if Computational FluidDynamics (CFD) can correctly predict the offending vessel in HFS and TN & thus improving the outcome of Microvascular Decompression) MVD. Settings and Design: CFD is a relatively new mode of imaging. Its application to indicate offending vessel in TN & HFS was tested. Materials & Methods: Retrospectively we studied 13 consecutive patients operated in 2017 for either HFS or TN. Preoperatively MRI & Computed Tomography Angiogram (CTA) were done and the offending vessel identified along with its point of contact with the concerned nerve. CFD was done using Hemoscope 2015 software and wall pressure, wall shear stress, vector & streamline flow were obtained in the offending vessel (test) & contralateral vessel (control). Results of these were charted on an excel sheet & results analyzed. The postoperativeoutcome were assessed and compared with CFD results. Statistical analysis used: Small study group hence statistical analysis couldn't be applied. Results: Of the 13 patients, offending artery had high wall pressure in 12 and increased wall shear stress innine. Among the controls six had high wall pressure and only two had high wall shear stress. Conclusion: CFD can be used to determine offending vessel and can predict good outcome following microvascular decompression. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
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20. The causal relationship between epigenetic abnormality and cancer development: in vivo reprogramming and its future application.
- Author
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Yosuke YAMADA and Yasuhiro YAMADA
- Published
- 2018
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21. In vivo reprogramming drives Kras-induced cancer development.
- Author
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Hironori Haga, Shingo Komura, Akito Tanaka, Tomoyo Ukai, Mio Kabata, Satoko Sakurai, Hirofumi Shibata, Yosuke Yamada, Knut Woltjen, Takuya Yamamoto, Yasuhiro Yamada, Bunya Kuze, Yatsuji Ito, Nao Sankoda, and Yoshiya Kawaguchi
- Subjects
INDUCED pluripotent stem cells ,GENE expression ,SOMATIC cells ,GENETIC transcription ,GENETIC mutation ,CANCER cells - Abstract
The faithful shutdown of the somatic program occurs in the early stage of reprogramming. Here, we examined the effect of in vivo reprogramming on Kras-induced cancer development. We show that the transient expression of reprogramming factors (1-3 days) in pancreatic acinar cells results in the transient repression of acinar cell enhancers, which are similarly observed in pancreatitis. We next demonstrate that Kras and p53 mutations are insufficient to induce ERK signaling in the pancreas. Notably, the transient expression of reprogramming factors in Kras mutant mice is sufficient to induce the robust and persistent activation of ERK signaling in acinar cells and rapid formation of pancreatic ductal adenocarcinoma. In contrast, the forced expression of acinar cell-related transcription factors inhibits the pancreatitisinduced activation of ERK signaling and development of precancerous lesions in Kras-mutated acinar cells. These results underscore a crucial role of dedifferentiation-associated epigenetic regulations in the initiation of pancreatic cancers. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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22. Srf destabilizes cellular identity by suppressing celltype-specific gene expression programs.
- Author
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Takashi Ikeda, Takafusa Hikichi, Hirofumi Shibata, Kanae Mitsunaga, Keisuke Okita, Yosuke Yamada, Knut Woltjen, Yasuhiro Yamada, Akitsu Hotta, Takuya Yamamoto, Shinji Masui, Hisashi Miura, Ichiro Hiratani, and Kei Miyamoto
- Subjects
MULTICELLULAR organisms ,CELLULAR evolution ,EUKARYOTES ,UNICELLULAR organisms ,CELL adhesion ,CELL communication - Abstract
Multicellular organisms consist of multiple cell types. The identity of these cells is primarily maintained by cell-type-specific gene expression programs; however, mechanisms that suppress these programs are poorly defined. Here we show that serum response factor (Srf), a transcription factor that is activated by various extracellular stimuli, can repress cell-typespecific genes and promote cellular reprogramming to pluripotency. Manipulations that decrease β-actin monomer quantity result in the nuclear accumulation of Mkl1 and the activation of Srf, which downregulate cell-type-specific genes and alter the epigenetics of regulatory regions and chromatin organization. Mice overexpressing Srf exhibit various pathologies including an ulcerative colitis-like symptom and a metaplasia-like phenotype in the pancreas. Our results demonstrate an unexpected function of Srf via a mechanism by which extracellular stimuli actively destabilize cell identity and suggest Srf involvement in a wide range of diseases. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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23. Real-time patency verification during clipping aneurysm and STA-MCA by-pass with dual-image videoangiography.
- Author
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Riki Tanaka, Anton Shatokhin, Ilya Senko, Ishu Bishnoi, Treepob Sae-Ngow, Yasuhiro Yamada, Daisuke Suyama, Tsukasa Kawase, Yoko Kato, and Ahmed Ansari
- Subjects
ANEURYSM surgery ,ANGIOGRAPHY ,INDOCYANINE green ,SURGICAL anastomosis ,BRAIN surgery - Abstract
The dual-image videoangiography (DIVA) is a new tool which helps identify ves-sels and surrounding structure. This method is based on use of indocyanine green video angiography (ICG-VA) technology on real time microscopic operative image. In this two case, we report of using DIVA in STA-MCA bypass surgery of 46 years old, female patient of stenosis of right MCA. And using DIVA during clipping ICA paraclinod aneurysm of 35 years old, female. During surgery, it helped in identifying temporal and frontal branches of the STA and there careful selection. After anastomosis, DIVA was used to refine vessel patency and functioning of the anastomosis. DIVA has the potential to replace ICG-VA as a tool for checking the patency of graft during bypass procedures and obliteration of aneurysm along with surgical procedures for AVM and d-AVF. DIVA allows visualization of vessels against a background of normal brain and has better visualization at greater depth and high magnification. This is particularly important during bypass surgery, which very often is performed in deep surgical fields and high magnification. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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24. Review--Light Emission from Thin Film Solar Cell Materials: An Emerging Infrared and Visible Light Emitter.
- Author
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Yoshihiko Kanemitsu, Makoto Okano, Le Quang Phuong, and Yasuhiro Yamada, Julius L. Jr.
- Published
- 2018
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25. Study of predisposing risk factors and etiology of chronic subdural hematoma in clipped patients of unruptured intracranial aneurysms - an institutional experience.
- Author
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Kawase, T., Ansari, Ahmed, Yoko Kato, Yasuhiro Yamada, and Riki Tanaka
- Subjects
SUBDURAL hematoma ,INTRACRANIAL aneurysms ,ETIOLOGY of diseases ,DISEASE risk factors - Abstract
Introduction: Chronic subdural hematoma in clipped patients of unruptured intracranial aneurysms might lead to sudden neurological deterioration and may need emergency evacuation. We studied the effects of various factors in its etiology. Materials and methods: A retrospective study of 91operated clipped patients of unruptured aneurysms in the year 2014-2015 was taken. Various predisposing factors were studied. Results: Goreisan use was not associated with any reduction in post operative CSDH formation. Arachnoidoplasty and reduced post operative dead space contributed in a reduced formation of CSDH. Conclusion: Older male patients with aneurysms who had been treated with anticoagulant drugs should be considered candidates for additive ARP to prevent the development of postoperative CSDH. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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26. Long term prognosis of ventriculoatrial shunt for idiopathic normal pressure hydrocephalus in the elderly.
- Author
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Tsukasa Kawase, Riki Tanaka, Yasuhiro Yamada, Ul Haq Siddiqui, Shamim, Yoko Kato, Kiyoshi Takagi, and Ansari, Ahmed
- Subjects
HYDROCEPHALUS ,DISEASES in older people ,PROGNOSIS - Abstract
Objective: A retrospective study was conducted to access the long-term prognosis of inserting the Ventriculoatrial (VA) shunt in the elderly for the idiopathic normal pressure hydrocephalus (iNPH). Material and Methods: Retrospective data is collected from April 2004 to August 2015, and 1065 patients were selected. Patients who underwent surgical examination or surgery in suspected iNPH were included. Tap test is done in all cases and found to be effective for 968 cases and 656 VA shunts for 614 cases. Out of 614 cases there are 440 cases in which patient age were over 75 years. Of these 440 cases only 141 cases were able to observe 03 years or more after the surgery, 37 deaths and 05 cases with survival and unknown prognosis were found among them. So we analyzed this group mainly in 99 cases that the prognosis after 03 years was known. We access the outcome of VA shunt by the modified Rankin scale (mRS), iNPH grading scale (iNPHGS) and complications in the operative 656 cases and in 03 years follow up of 141 patients. Results: Of 141, there are 78 males and 63 females. Age at the time of VA shunt insertion was 81.5±4.1 years and age at final follow-up was 85.2±4.4 years. The proportion of patients who achieved a favorable outcome by complications was 97.9% in 03 years follow-up period and 87.7% in which follow-up is less than 03 years. At the time of VA shunt insertion out of 141, 57 patients lies between 75-79 years, 57 between 80-84, 24 between 85 to 89, and only 03 were found to be 90 years or more. At the time of final follow-up at 03 years, 15 patients lies between 75 to 79 years, 56 between 80 to 84 years, 57 between 85 to 89 years and 23 patents were found to be 90 years or greater. 70 cases or almost 50% exceeded 85 years. At the time of VA shunt 1, 11, 39, 51, 36, 3, 0 patients were in 0 to 6 modified Rankin Scale Score respectively and at 03 years follow-up 8, 19, 32, 29, 9, 2, 37 were in 0 to 6 mRS respectively. Comparison of the study is done with SIPHONI study on VP shunt and LP shunt. Conclusion: Patients suspected of having idiopathic normal pressure hydrocephalus were treated by VA shunt and found no significant difference in serious adverse effects. This study shows that VA shunt is an effective choice for iNPH in the late elderly population, but it needs more randomized control trial to establish its efficacy. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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27. Predictive Value of Motor Evoked Potential Monitoring during Surgery of Unruptured Anterior Circulation Cerebral Aneurysms.
- Author
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Yasuhiro Yamada, Yoko Kato, Nouri, Mohsen, Tsukasa Ganaha, Motoki Oheda, Kohei Ishihara, Shigeta Moriya, Akiyo Sadato, Joji Inamasu, and Yuichi Hirose
- Subjects
INTRACRANIAL aneurysm surgery ,EVOKED potentials (Electrophysiology) ,PATIENT monitoring ,NEUROVASCULAR surgery ,ENDOSCOPES - Abstract
Objective and Background: Surgery of unruptured aneurysms is always a great challenge to neurovascular surgeons because no postoperative neurological deficits should be expected postoperatively as the patients are fully asymptomatic before the surgery. Here, we present our experience with selective motor evoked potential (MEP) monitoring of our patients in a 2-year time window. Patients and Methods: From 2012 to 2014, 27 patients with unruptured intracranial aneurysms were operated in our institute with the help of MEP monitoring. All patients underwent endoscope-assisted microsurgery with pre- and post-clipping indocyanine green angiography. Results: In this period, no mortality was observed, but 18.5% of the patients developed postoperative deficits which showed good recovery in all cases. Overall, MEP showed about 90% accuracy in predicting postoperative deficits. Conclusions: MEP as a part of multimodality monitoring of aneurysm surgeries is a valuable tool to improve the outcome. However, we should know its limitations as its results are not always consistent with the outcome. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
28. Intraoperative Anatomical and Hemodynamic Analysis of Intracerebral Arteriovenous Malformations by Semi-quantitative Color-coded Indocyanine Green Videoangiography.
- Author
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Yoko Kato, Yasuhiro Yamada, Akiyo Sadato, Nouri, Mohsen, Cherian, Iype, Teppei Tanaka, and Joji Inamasu
- Subjects
CEREBRAL arteriovenous malformations ,HEMODYNAMICS ,ARTERIOVENOUS malformation ,ANGIOGRAPHY ,INDOCYANINE green ,THERAPEUTICS - Abstract
Objective and Background: To evaluate possible roles for indocyanine green (ICG)-based FLOW 800 software in surgical treatment of cerebral arteriovenous malformations (AVMs). Methods: We perform ICG videoangiography several times for each step of AVM resection to elucidate feeders, drainers, and cerebral perfusion. Results: Since 2010, 22 AVM surgeries in our department have been conducted using FLOW 800 intraoperatively. We demonstrated ICG angiograms, color-coded images, and semi-quantitative curves for AVMs. By reviewing all these modalities, we would define vascular structure of the AVM, proceed with resection, and finally recheck for any remnant. Conclusions: ICG FLOW 800 software helps the surgeon to recognize feeding and draining vessels of an AVM intraoperatively. Further studies to evaluate semi-quantitative acquired data regarding blood flow and tissue perfusion are warranted. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
29. Synthesis of ordered carbonaceous frameworks from organic crystals.
- Author
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Hirotomo Nishihara, Tetsuya Hirota, Kenta Matsuura, Mao Ohwada, Norihisa Hoshino, Tomoyuki Akutagawa, Takeshi Higuchi, Hiroshi Jinnai, Yoshitaka Koseki, Hitoshi Kasai, Yoshiaki Matsuo, Jun Maruyama, Yuichiro Hayasaka, Hisashi Konaka, Yasuhiro Yamada, Shingi Yamaguchi, Kazuhide Kamiya, Takuya Kamimura, Hirofumi Nobukuni, and Fumito Tani
- Abstract
Despite recent advances in the carbonization of organic crystalline solids like metal-organic frameworks or supramolecular frameworks, it has been challenging to convert crystalline organic solids into ordered carbonaceous frameworks. Herein, we report a route to attaining such ordered frameworks via the carbonization of an organic crystal of a Ni-containing cyclic porphyrin dimer (Ni
2 -CPDPy ). This dimer comprises two Ni–porphyrins linked by two butadiyne (diacetylene) moieties through phenyl groups. The Ni2 -CPDPy crystal is thermally converted into a crystalline covalent-organic framework at 581 K and is further converted into ordered carbonaceous frameworks equipped with electrical conductivity by subsequent carbonization at 873–1073 K. In addition, the porphyrin’s Ni–N4 unit is also well retained and embedded in the final framework. The resulting ordered carbonaceous frameworks exhibit an intermediate structure, between organic-based frameworks and carbon materials, with advantageous electrocatalysis. This principle enables the chemical molecular-level structural design of three-dimensional carbonaceous frameworks. [ABSTRACT FROM AUTHOR]- Published
- 2017
- Full Text
- View/download PDF
30. Surgical treatment of large and giant cavernous carotid aneurysms.
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Sriamornrattanakul, Kitiporn, Sakarunchai, Ittichai, Kei Yamashiro, Yasuhiro Yamada, Daisuke Suyama, Tsukasa Kawase, and Yoko Kato
- Subjects
ANEURYSM surgery ,SKULL base ,NEUROLOGICAL disorders ,THROMBOSIS ,SURGICAL complications - Abstract
Cavernous carotid aneurysms (CCAs) are uncommon pathologic entities. Extradural place and the skull base location make this type of an aneurysm different in clinical features and treatment techniques. Direct aneurysm clipping is technically difficult and results in a significant postoperative neurological deficit. Therefore, several techniques of indirect surgical treatment were developed with different surgical outcomes, such as proximal occlusion of internal carotid artery (ICA) or trapping with or without bypass (superficial temporal artery-middle cerebral artery bypass or high-flow bypass). High-flow bypass with proximal ICA occlusion seems to be the most appropriate surgical treatment for CCA because of the high rate of symptom improvement, aneurysm thrombosis, and minimal postoperative complications. However, in cases of CCA presented with direct carotid-cavernous fistula, the appropriate surgical treatment is high-flow bypass with aneurysm trapping, which the fistula can be obliterated immediately after surgery. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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- View/download PDF
31. RISER DRILLING: Access to Deep Subseafloor Science.
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Yasuhiro Yamada, Dugan, Brandon, Takehiro Hirose, and Saneatsu Saito
- Subjects
RISER pipe ,DRILLING fluids ,DRILLING muds ,SCIENTISTS ,FLUID pressure - Abstract
Riser-based drilling became available to scientists for the first time when the Japanese drilling vessel (D/V) Chikyu began operations in 2005. The introduction of a vessel that could take advantage of riser drilling technology was a key advancement as scientific ocean drilling transitioned from the Ocean Drilling Program to the Integrated Ocean Drilling Program. Because riser drilling enables control of downhole pressure, Chikyu opened a new frontier for scientists, allowing for deeper drilling and sampling of the subseafloor to at least 7 km depths. Riserless drilling uses seawater as drilling fluid, and technical difficulties may arise when the borehole becomes unstable. In contrast, riser drilling uses riser pipes that connect the ship to the wellhead at the seafloor (Figure 1). Circulation of weighted drill mud through the riser pipe stabilizes the borehole during deep drilling operations, allowing continuous sampling and data collection, including from cuttings, mud gas, and downhole logging. These samples and data allow characterization of in situ physical properties (e.g., stress, fluid pressure) and gas and fluid chemistry. Riser drilling operations in the Nankai Trough and off Shimokita Peninsula in Japan demonstrate the value of this technology to achieving new understanding of the processes occurring deep in seismogenic zones. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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32. Cellular context-dependent consequences of Apc mutations on gene regulation and cellular behavior.
- Author
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Kyoichi Hashimoto, Yosuke Yamada, Katsunori Semi, Masaki Yagi, Akito Tanaka, Fumiaki Itakura, Hitomi Aoki, Takahiro Kunisada, Knut Woltjen, Hironori Haga, Yoshiharu Sakai, Takuya Yamamoto, and Yasuhiro Yamada
- Subjects
GENETIC mutation ,CHROMOSOME abnormalities ,CANCER cells ,CELLULAR pathology ,GENE expression - Abstract
The spectrum of genetic mutations differs among cancers in different organs, implying a cellular context-dependent effect for genetic aberrations. However, the extent to which the cellular context affects the consequences of oncogenic mutations remains to be fully elucidated. We reprogrammed colon tumor cells in an Apc
Min/+ (adenomatous polyposis coli) mouse model, in which the loss of the Apc gene plays a critical role in tumor development and subsequently, established reprogrammed tumor cells (RTCs) that exhibit pluripotent stem cell (PSC)-like signatures of gene expression. We show that the majority of the genes in RTCs that were affected by Apc mutations did not overlap with the genes affected in the intestine. RTCs lacked pluripotency but exhibited an increased expression of Cdx2 and a differentiation propensity that was biased toward the trophectoderm cell lineage. Genetic rescue of the mutated Apc allele conferred pluripotency on RTCs and enabled their differentiation into various cell types in vivo. The redisruption of Apc in RTC-derived differentiated cells resulted in neoplastic growth that was exclusive to the intestine, but the majority of the intestinal lesions remained as pretumoral microadenomas. These results highlight the significant influence of cellular context on gene regulation, cellular plasticity, and cellular behavior in response to the loss of the Apc function. Our results also imply that the transition from microadenomas to macroscopic tumors is reprogrammable, which underscores the importance of epigenetic regulation on tumor promotion. [ABSTRACT FROM AUTHOR]- Published
- 2017
- Full Text
- View/download PDF
33. Preoperative lipiodol marking and its role on survival and complication rates of CT-guided cryoablation for small renal masses.
- Author
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Fumiya Hongo, Yasuhiro Yamada, Takashi Ueda, Terukazu Nakmura, Yoshio Naya, Kazumi Kamoi, Koji Okihara, Yusuke Ichijo, Tsuneharu Miki, Kei Yamada, Osamu Ukimura, Hongo, Fumiya, Yamada, Yasuhiro, Ueda, Takashi, Nakmura, Terukazu, Naya, Yoshio, Kamoi, Kazumi, Okihara, Koji, Ichijo, Yusuke, and Miki, Tsuneharu
- Subjects
CRYOSURGERY ,NEPHRECTOMY ,ABLATION techniques ,RENAL cell carcinoma ,MAGNETIC resonance imaging ,ANTHROPOMETRY ,CLINICAL trials ,COMPUTED tomography ,KIDNEY tumors ,PREOPERATIVE care ,SURGICAL complications ,SURVIVAL ,VEGETABLE oils ,CONTRAST media ,RETROSPECTIVE studies ,COMPUTER-assisted surgery ,SURGERY - Abstract
Background: Partial nephrectomy for small renal masses (SRM) may be useful for preserving renal function, but is technically more difficult than radical nephrectomy. Cryoablation may be performed under local anesthesia. The objective of the present study is to assess the safety and therapeutic efficacy of cryoablation with lipiodol marking for SRM.Methods: Cryoablation therapy was performed on 42 patients under local anesthesia. Their median age was 74 years (31-91). The median tumor diameter was 21 mm (10-42). Responses to the treatment were evaluated using modified Response Evaluation Criteria in Solid Tumors (mRECIST) by contrast-enhanced CT. In six patients (14.3%) for whom it was not possible to use contrast medium, plain CT findings were assessed according to Response Evaluation Criteria in Solid Tumors (RECIST).Results: Twenty-nine (69%) and five (12%) patients achieved complete responses (CR) and partial responses (PR), respectively, while four (10%) and four (10%) patients each had stable disease (SD) and progressive disease (PD) after the first course of therapy. A second course of cryoablation therapy with lipiodol marking was performed on three out of four patients with PD after the first course of therapy, and resulted in a total of 32 patients achieving CR (76%). Four (36.4%) out of 11 patients for whom lipiodol marking was not conducted had PD, whereas none of the 31 patients for whom lipiodol marking was conducted had PD. All grade complications were reported in 11 (24.4%) patients while grade 3 in two (4.4%) patients. 11 (24.4%) A significant difference was observed in postoperative hemorrhagic events in all grades (18% in patients undergoing cryoablation without lipiodol marking vs. 0% in patients undergoing cryoablation without lipiodol marking).Conclusions: Although further studies involving more patients are needed in order to evaluate long-term results, cryoablation therapy appears to be a useful treatment option for SRM. Preoperative marking with lipiodol was helpful for improving complication and survival rates with cryoablation. [ABSTRACT FROM AUTHOR]- Published
- 2017
- Full Text
- View/download PDF
34. State-of-Art Surgical Treatment of Dissecting Anterior Circulation Intracranial Aneurysms.
- Author
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Balik, Vladimir, Yasuhiro Yamada, Talari, Sandeep, Yamashiro Kei, Hirotoshi Sano, Sulla, Igor, Daisuke Suyama, Tukasa Kawase, Kiyoshi Takagi, Katsumi Takizawa, and Yoko Kato
- Subjects
INTRACRANIAL aneurysms ,SUBARACHNOID hemorrhage ,ENDOVASCULAR surgery ,SYSTEMATIC reviews ,CLINICAL trials ,THERAPEUTICS - Abstract
Intracranial dissecting aneurysms (IDAs) are an important cause of subarachnoid hemorrhage, stroke, or compression of intracranial structures. Since the availability of endovascular treatment and the advantage of intraprocedural anticoagulation, an endovascular strategy has become the mainstay of their therapy. But in some cases selective aneurysm obliteration by the endovascular approach is impossible or associated with an unacceptable risk of morbidity. This is particularly true when the IDA is a blood blister-like aneurysm or when dissection affects peripheral branches of the internal carotid artery. The literature dealing with surgical treatment of IDAs in the anterior circulation is heterogeneous, and formulation of general recommendations concerning the surgical strategy remains difficult. The aim of this study was to conduct a systematic review of the current knowledge on incidence, pathogenesis, clinical presentation, and diagnostic procedures with a special emphasis on the surgical treatment of intracranial dissections of anterior circulation. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
35. Comparison of computational fluid dynamics findings with intraoperative microscopy findings in unruptured intracranial aneurysms-An initial analysis.
- Author
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Talari, Sandeep, Yoko Kato, Hanbing Shang, Yasuhiro Yamada, Kei Yamashiro, Daisuke Suyama, Tsukasa Kawase, Vladimir Balik, and Wu Rile
- Subjects
COMPUTATIONAL fluid dynamics ,ANEURYSM diagnosis ,MICROSCOPY ,ORGAN rupture -- Risk factors ,ATHEROSCLEROSIS ,SHEARING force - Abstract
Context: The increase in the detection of unruptured cerebral aneurysms has led to management dilemma. Prediction of risk based on the size of the aneurysm is not always accurate. There is no objective way of predicting rupture of aneurysm so far. Computational fluid dynamics (CFDs) was proposed as a tool to identify the rupture risk. Aims: To know the correlation of CFD findings with intraoperative microscopic findings and to know the relevance of CFD in the prediction of rupture risk and in the management of unruptured intracranial aneurysms. Settings and Design: A prospective study involving nine cases over a period of 6 months as an initial analysis. Subjects and Methods: Both males and females were included in the study. Preoperative analysis was performed using computed tomography angiogram, magnetic resonance imaging in all cases and digital substraction angiogram in some cases. Intraoperatively microscopic examination of the aneurysm wall was carried out and images recorded. The correlation was done between microscopic and CFD images. Results: Seven cases were found intraoperatively to have a higher risk of rupture based on the thinning of the wall. Two cases had an atherosclerotic wall. All cases had low wall shear stress (WSS).Only two cases with atherosclerotic wall had a correlation with low WSS. Conclusions: While the pressure measured with CFD technique is a good predictor of rupture risk, the WSS component is controversial. Multicentric trials involving a larger subset of population are needed before drawing any definite conclusions. On-going development in the CFD analysis may help to predict the rupture chances accurately in future. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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- View/download PDF
36. Preface to the special issue on interdisciplinary studies tackling the Jomon social structure.
- Author
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Yasuhiro Yamada
- Published
- 2022
- Full Text
- View/download PDF
37. Salvage brachytherapy for locally recurrent prostate cancer after external beam radiotherapy.
- Author
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Yasuhiro Yamada, Koji Okihara, Tsuyoshi Iwata, Koji Masui, Kazumi Kamoi, Kei Yamada, and Tsuneharu Miki
- Abstract
External beam radiotherapy (EBRT) is a standard treatment for prostate cancer. Despite the development of novel radiotherapy techniques such as intensity-modulated conformal radiotherapy, the risk of local recurrence after EBRT has not been obviated. Various local treatment options (including salvage prostatectomy, brachytherapy, cryotherapy, and high-intensity focused ultrasound [HIFU]) have been employed in cases of local recurrence after primary EBRT. Brachytherapy is the first-line treatment for low-risk and selected intermediate-risk prostate tumors. However, few studies have examined the use of brachytherapy to treat post-EBRT recurrent prostate cancer. The purpose of this paper is to analyze the current state of our knowledge about the effects of salvage brachytherapy in patients who develop locally recurrent prostate cancer after primary EBRT. This article also introduces our novel permanent brachytherapy salvage method. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
38. Salvage brachytherapy for locally recurrent prostate cancer after external beam radiotherapy.
- Author
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Yasuhiro Yamada, Koji Okihara, Tsuyoshi Iwata, Koji Masui, Kazumi Kamoi, Kei Yamada, and Tsuneharu Miki
- Abstract
External beam radiotherapy (EBRT) is a standard treatment for prostate cancer. Despite the development of novel radiotherapy techniques such as intensity-modulated conformal radiotherapy, the risk of local recurrence after EBRT has not been obviated. Various local treatment options (including salvage prostatectomy, brachytherapy, cryotherapy, and high-intensity focused ultrasound [HIFU]) have been employed in cases of local recurrence after primary EBRT. Brachytherapy is the first-line treatment for low-risk and selected intermediate-risk prostate tumors. However, few studies have examined the use of brachytherapy to treat post-EBRT recurrent prostate cancer. The purpose of this paper is to analyze the current state of our knowledge about the effects of salvage brachytherapy in patients who develop locally recurrent prostate cancer after primary EBRT. This article also introduces our novel permanent brachytherapy salvage method. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
39. Femtosecond upconverted photocurrent spectroscopy of InAs quantum nanostructures.
- Author
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Yasuhiro Yamada, Tex, David M., Itaru Kamiya, and Yoshihiko Kanemitsu
- Subjects
FEMTOSECOND lasers ,PHOTOCURRENTS ,SPECTRUM analysis ,INDIUM arsenide ,QUANTUM theory ,NANOSTRUCTURED materials - Abstract
The carrier upconversion dynamics in InAs quantum nanostructures are studied for intermediateband solar-cell applications via ultrafast photoluminescence and photocurrent (PC) spectroscopy based on femtosecond excitation correlation (FEC) techniques. Strong upconverted PC-FEC signals are observed under resonant excitation of quantum well islands (QWIs), which are a few monolayer-thick InAs quantum nanostructures. The PC-FEC signal typically decays within a few hundred picoseconds at room temperature, which corresponds to the carrier lifetime in QWIs. The photoexcited electron and hole lifetimes in InAs QWIs are evaluated as functions of temperature and laser fluence. Our results provide solid evidence for electron-hole-hole Auger process, dominating the carrier upconversion in InAs QWIs at room temperature. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
40. Reducing DNA methylation suppresses colon carcinogenesis by inducing tumor cell differentiation.
- Author
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Yuichiro Hatano, Katsunori Semi, Kyoichi Hashimoto, Myeong Sup Lee, Akihiro Hirata, Hiroyuki Tomita, Toshiya Kuno, Manabu Takamatsu, Koji Aoki, Taketo, Makoto M., Young-Joon Kim, Akira Hara, and Yasuhiro Yamada
- Subjects
DNA methylation ,COLON cancer ,CARCINOGENESIS ,CELL differentiation ,CANCER cells - Abstract
The forced reduction of global DNA methylation suppresses tumor development in several cancer models in vivo. Nevertheless, the mechanisms underlying these suppressive effects remain unclear. In this report, we describe our findings showing that a genome-wide reduction in the DNA methylation levels induces cellular differentiation in association with decreased cell proliferation in ApcMin/+ mouse colon tumor cells in vivo. Colon tumor-specific DNA methylation at Cdx1 is reduced in the DNA-hypomethylated tumors accompanied by Cdx1 derepression and an increased expression of intestinal differentiation-related genes. Furthermore, a histological analysis revealed that Cdx1 derepression in the DNA-hypomethylated tumors is correlated with the differentiation of colon tumor cells. Similarly, the treatment of human colon cancer cell lines with a hypomethylating agent induces differentiation-related genes, including CDX1. We herein propose that DNA demethylation exerts a tumor suppressive effect in the colon by inducing tumor cell differentiation. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
41. Role of endoscopy in multi-modality monitoring during aneurysm surgery: A single center experience with 175 consecutive unruptured aneurysms.
- Author
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Yasuhiro Yamada, Yoko Kato, Kohei Ishihara, Keisuke Ito, Takafumi Kaito, Mohsen Nouri, Motoki Oheda, Joji Inamasu, and Yuichi Hirose
- Subjects
ANEURYSM surgery ,VASCULAR surgery ,ENDOSCOPIC surgery ,MICROSURGERY ,ANGIOGRAPHY ,EVOKED potentials (Electrophysiology) - Abstract
Objective and Background: Unruptured aneurysm surgery is a challenge to all vascular neurosurgeons as the patient is asymptomatic and no even slight neurological deficits should be expected postoperatively. To this aim, multi-modality checking of the vessels during the surgery is highly recommended to assure of the patency of the parent and perforator arteries next to an aneurysm. In this paper, we present our experience in the last 1.5 years with emphasis on the role of endoscope assisted microsurgery. Methods: One hundred and seventy-five patients with unruptured intracranial aneurysms were operated in our institute in the last 1 1/2 years. All patients underwent endoscope assisted microsurgery with pre- and post-clipping indocyanine green angiography. In selected cases, motor evoked potential monitoring was implemented. Results: No mortality was observed in this period, and only 6 patients (3.4%) suffered new permanent neurological deficits postoperatively. Our illustrative cases show how endoscopy may help the surgeon to visualize hidden vessels behind and medial to an aneurysm. Conclusions: Our results indicated that multi-modality monitoring during unruptured aneurysm surgeries is associated with excellent outcome. Endoscope is able to show blind corners during aneurysm surgery which cannot be routinely observed with microscope and its application in aneurysm surgery assists the surgeon to make certain of complete neck clipping and preservation of perforating arteries around the aneurysm. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
42. Concise Review: Dedifferentiation Meets Cancer Development: Proof of Concept for Epigenetic Cancer.
- Author
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YOSUKE YAMADA, HIRONORI HAGA, and YASUHIRO YAMADA
- Published
- 2014
- Full Text
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43. Temperature-dependent photocarrier recombination dynamics in Cu2ZnSnS4 single crystals.
- Author
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Le Quang Phuong, Makoto Okano, Yasuhiro Yamada, Akira Nagaoka, Kenji Yoshino, and Yoshihiko Kanemitsu
- Subjects
RECOMBINATION (Chemistry) ,PHOTOLUMINESCENCE ,KESTERITE ,SOLAR cells ,EXCITATION spectrum ,RADIATIONLESS transitions - Abstract
Time-resolved photoluminescence (PL) measurements have been used to study the temperature-dependent photocarrier recombination dynamics in Cu
2 ZnSnS4 (CZTS) single crystals. We found a significant change of nearly four orders of magnitude of the PL decay time, from microseconds at low temperatures to subnanoseconds at room temperature. The slow PL decay at low temperatures indicates localization of the photocarriers at the band tails. Due to the large band tail states, the PL decay time depends strongly on both the photon energy and excitation density. It is pointed out that the drastically enhanced nonradiative recombination at high temperatures is one of the main factors that determine the power conversion efficiency of CZTS-based solar cells. [ABSTRACT FROM AUTHOR]- Published
- 2014
- Full Text
- View/download PDF
44. Narrow Energy Gap between Triplet and Singlet Excited States of Sn2+ in Borate Glass.
- Author
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Hirokazu Masai, Yasuhiro Yamada, Yuto Suzuki, Kentaro Teramura, Yoshihiko Kanemitsu, and Toshinobu Yoko
- Subjects
OPTICAL properties of borate glass ,ENERGY-band theory of solids ,PROPERTIES of matter ,PHOTOLUMINESCENCE ,ALKALINE earth metals ,QUANTUM optics ,QUANTUM theory - Abstract
Transparent inorganic luminescent materials have attracted considerable scientific and industrial attention recently because of their high chemical durability and form ability. However, photoluminescence dynamics of ns
2 -type ions in oxide glasses has not been well examined, even though they can exhibit high quantum efficiency. We report on the emission property of Sn2+ -doped strontium borate glasses. Photoluminescence dynamics studies show that the peak energy of the emission spectrum changes with time because of site distribution of emission centre in glass. It is also found that the emission decay of the present glass consists of two processes: a faster S1 -S0 transition and a slower T1 -S0 relaxation, and also that the energy difference between T1 and S1 states was found to be much smaller than that of (Sn, Sr)B6O10 crystals. We emphasize that the narrow energy gap between the S1 and T1 states provides the glass phosphor a high quantum efficiency, comparable to commercial crystalline phosphors. [ABSTRACT FROM AUTHOR]- Published
- 2013
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- View/download PDF
45. THE PURITY MEASURE FOR GENOMIC REGIONS LEADS TO HORIZONTALLY TRANSFERRED GENES.
- Author
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YUTA TANIGUCHI, YASUHIRO YAMADA, OSAMU MARUYAMA, SATORU KUHARA, and DAISUKE IKEDA
- Subjects
GENOMICS ,HORIZONTAL gene transfer ,NUCLEOTIDE sequence ,RNA ,TRANSPOSONS ,MARKOV processes ,TEXT mining - Abstract
Sequence analysis is important to understand a genome, and a number of approaches such as sequence alignments and hidden Markov models have been employed. In the field of text mining, the purity measure is developed to detect unusual regions of a string without any domain knowledge. It is reported in that work that only RNAs and transposons are shown to have high purity values. In this work, the purity values of regions of various bacterial genome sequences are computed, and those regions are analyzed extensively. It is found that mobile elements and phages as well as RNAs and transposons have high purity values. It is interesting that they are all classified into a group of horizontally transferred genes. This means that the purity measure is useful to predict horizontally transferred genes. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
46. Epigenetic regulation in pluripotent stem cells: a key to breaking the epigenetic barrier.
- Author
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Akira Watanabe, Yasuhiro Yamada, and Shinya Yamanaka
- Subjects
CELL differentiation ,EPIGENESIS ,PLURIPOTENT stem cells ,SOMATIC cells ,SPATIOTEMPORAL processes - Abstract
The differentiation and reprogramming of cells are accompanied by drastic changes in the epigenetic profiles of cells. Waddington's classical model clearly describes how differentiating cells acquire their cell identity as the developmental potential of an individual cell population declines towards the terminally differentiated state. The recent discovery of induced pluripotent stem cells as well as of somatic cell nuclear transfer provided evidence that the process of differentiation can be reversed. The identity of somatic cells is strictly protected by an epigenetic barrier, and these cells acquire pluripotency by breaking the epigenetic barrier by reprogramming factors such as Oct3/4, Sox2, Klf4, Myc and LIN28. This review covers the current understanding of the spatio-temporal regulation of epigenetics in pluripotent and differentiated cells, and discusses how cells determine their identity and overcome the epigenetic barrier during the reprogramming process. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
47. Neuron-like Differentiation and Selective Ablation of Undifferentiated Embryonic Stem Cells Containing Suicide Gene with Oct-4 Promoter.
- Author
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Akira Hara, Hitomi Aoki, Ayako Taguchi, Masayuki Niwa, Yasuhiro Yamada, Takahiro Kunisada, and Hideki Mori
- Published
- 2008
- Full Text
- View/download PDF
48. Endoscopic-assisted paramedian infratentorial supracerebellar approach for pineal cyst - How I do it Video clip.
- Author
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Riki Tanaka, Kazuhito Takeuchi, Ansari, Ahmed, Kento Sasaki, Kyosuke Miyatani, Yasuhiro Yamada, Tsukasa Kawase, Yoko Kato, and Akihiko Horiguchi
- Subjects
VIDEO excerpts ,GENERAL anesthesia ,VEINS ,CEREBELLUM - Abstract
Background: The endoscopic supracerebellar-infratentorial (SCIT) approach is a viable method to access pathology of the posterior incisura, but a narrow working space and frequent instrument conflict can potentially limit its surgical efficacy. We planned an endoscopic-assisted paramedian infratentorial supracerebellar approach for pineal cyst. Case Description: Patient was placed in prone position under general anesthesia. His head was rotated to the left side slightly. The location of the transverse sinus was detected with navigation system. A 5 cm linear skin incision was performed, and a 2 cm craniectomy was performed about 2 cm left of the median. The transverse sinus was little bit exposed. Dura was incised in a U-shaped incision with the transverse sinus at the base. The endoscope was advanced along with the culmen. At that time, we observed inferior and superior vermian vein. After reaching to the thick arachnoid near by galenic system, the arachnoid membrane was incised and the CSF was evacuated. After that, the cerebellum became soft and the surgical corridor became large. The arachnoid membrane was incised widely. Pineal cyst, precentral cerebellar vein, bilateral internal occipital vein and great vein of galen were exposed. There were some small veins on the pineal cyst, but the adhesion was not so severe. The cyst was dissected from these small veins. There was no adhesion between the cyst and surrounding brain except for the pineal recess. Bilateral ICV was seen behind the cyst. There was feeding artery and draining vein on the antero-lateral part of the cyst. These vessels were coagulated and cut, then the cyst was removed. After the removal, we confirmed complete removal of the cyst and hemostasis. Conclusion: Endoscopic-assisted paramedian SCIT approach for pineal cyst in prone position is a reasonable and efficient access for posterior third ventricular lesions. The learning curve, maneuverability in small space, and instrument conflict limit efficacy. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
49. Perilesional hyperintense rim of malignant hepatic tumors on ferumoxide-enhanced T1-weighted gradient-echo MR images: Correlation between MR imaging and histopathologic findings.
- Author
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Masayuki Kanematsu, Masayuki Matsuo, Yasuhiro Yamada, Richard C. Semelka, Hiroshi Kondo, Satoshi Goshima, Hiroaki Hoshi, and Noriyuki Moriyama
- Abstract
To correlate the perilesional hyperintense rim of malignant hepatic tumors seen on ferumoxide-enhanced T1-weighted gradient-echo (GE) MR images with histopathologic findings. In 13 tumors in 12 patients, T1-weighted GE images (TE of 1.4 msec, flip angle of 90 degrees) obtained after IV administration of ferumoxide were evaluated. MR imaging was initiated within one hour of the completion of ferumoxide administration. Surgical resection for tumors was performed within an interval of two weeks of the MR imaging. Resected specimens were histopathologically examined for peritumoral sinusoidal congestion, desmoplastic reaction, compressed hepatic parenchyma, lymphocytic infiltration, and vascular proliferation. In twelve tumors (92%), prominently (N = 2), moderately (N = 5), and mildly to minimally (N = 5), a perilesional hyperintense rim was observed. Among histopathologic findings, the degree of peritumoral sinusoidal congestion correlated (R = .75, P < .04) with the degree of perilesional hyperintense rim. The thickness of the perilesional hyperintense rim showed a moderate positive correlation (R = .65, P < .02) with the thickness of peritumoral area with sinusoidal congestion. Perilesional hyperintense rim of malignant hepatic tumors on ferumoxide-enhanced T1-weighted GE images may correlate with sinusoidal congestion surrounding malignant hepatic tumors. J. Magn. Reson. Imaging 2003;18:4048. © 2003 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]
- Published
- 2003
- Full Text
- View/download PDF
50. Bi3+ Heterovalent Doping in APbBr3 Lead Halide Perovskite Single Crystals: Urbach Tail and Photon Recycling Effect.
- Author
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Mizuki Hoyano, Ryo Akashi, Kenichi Oto, Yoshihiko Kanemitsu, and Yasuhiro Yamada
- Published
- 2019
- Full Text
- View/download PDF
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