Publications by authors named "Akihiko Ikeda"

Rationale: Treatment strategies for rectal squamous cell carcinoma (rSCC) are yet to be established, given its rarity. Although squamous cell carcinoma has been reported to be highly sensitive to cetuximab and radiation, there is no report of combination therapy of cetuximab and radiation for rSCC. In this study, we firstly reported a case of rSCC in which a complete response was achieved with the original chemoradiotherapy comprising oxaliplatin, S-1, cetuximab, and simultaneous radiation.

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A 61-year-old woman, who had a history of total thyroidectomy for follicular variant of papillary thyroid carcinoma (PTC), visited our hospital for assessment of an enlarging nodule which appeared in the lung with multiple metastatic lesions of PTC which had been stable for 17 years. Wedge resection of the lung was performed. Miliary nodules were confirmed to be metastatic PTCs based on their morphological as well as immunohistochemical findings.

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Article Synopsis
  • * After four cycles of the combination therapy, the patient's condition showed complete response on imaging, but side effects like eosinophilia and skin disorders developed during the treatment.
  • * The treatment was stopped, leading to normalization of eosinophil counts and gradual skin improvement, but after restarting the monotherapy two months later, the side effects recurred, prompting another treatment cessation.
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The mutual coupling of spin and lattice degrees of freedom is ubiquitous in magnetic materials and potentially creates exotic magnetic states in response to the external magnetic field. Particularly, geometrically frustrated magnets serve as a fertile playground for realizing magnetic superstructure phases. Here, we observe an unconventional two-step magnetostructural transition prior to a half-magnetization plateau in a breathing pyrochlore chromium spinel by means of state-of-the-art magnetization and magnetostriction measurements in ultrahigh magnetic fields available up to 600 T.

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Bose-Einstein condensation of electron-hole pairs, exciton condensation, has been effortfully investigated since predicted 60 years ago. Irrefutable evidence has still been lacking due to experimental difficulties in verifying the condensation of the charge neutral and non-magnetic spin-singlet excitons. Whilst, condensation of spin-triplet excitons is a promising frontier because spin supercurrent and spin-Seebeck effects will be observable.

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Bose-Einstein condensation (BEC) in quantum magnets, where bosonic spin excitations condense into ordered ground states, is a realization of BEC in a thermodynamic limit. Although previous magnetic BEC studies have focused on magnets with small spins of S ≤ 1, larger spin systems potentially possess richer physics because of the multiple excitations on a single site level. Here, we show the evolution of the magnetic phase diagram of S = 3/2 quantum magnet BaCoGeO when the averaged interaction J is controlled by a dilution of magnetic sites.

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We report a magnetostriction study of a perovskite LaCoO_{3} above 100 T using our state-of-the-art strain gauge to investigate an interplay between electron correlation and spin crossover. There has been a controversy regarding whether two novel phases in LaCoO_{3} at high magnetic fields result from crystallizations or Bose-Einstein condensation during spin crossover as manifestations of localization and delocalization in spin states, respectively. We show that both phases are crystallizations rather than condensations, and the two crystallizations are different, based on the observations that the two phases exhibit as magnetostriction plateaux with distinct heights.

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Metal-insulator (MI) transitions in correlated electron systems have long been a central and controversial issue in material science. Vanadium dioxide (VO) exhibits a first-order MI transition at 340 K. For more than half a century, it has been debated whether electron correlation or the structural instability due to dimerised V ions is the more essential driving force behind this MI transition.

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A simple method for measuring electrical resistivity under destructive pulsed magnetic fields is presented. This method uses pick-up voltage as the power source to allow the measurement of the absolute value of resistivity in ultra-high magnetic fields above 100 T. The experimental setup and its operation are described in detail, and its performance is demonstrated using critical field measurements of thin-film FeSeTe samples.

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This report presents the case of a 43-year-old man with inferior vena cava (IVC) compression caused by a retroperitoneal hematoma following an abdominal aortic aneurysm (AAA) rupture. Preoperative computed tomography scans revealed an infrarenal AAA with a retroperitoneal hematoma nearly occluding the IVC. After emergency aortic grafting, IVC thrombosis, deep venous thrombosis (DVT), and pulmonary thromboembolism (PTE) arose.

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Emphysematous pyelonephritis (EPN) is a life-threatening renal infection characterized by the formation of gas within the renal parenchyma and collecting duct system, as well as perinephric tissues. We herein report a case of bilateral EPN accompanied by the urinary tract infection caused by spherical growth of Candida albicans in a patient with underlying diabetes mellitus and prostate cancer. The diagnosis was assisted by computed tomography, urography, and gram staining.

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High-resolution magnetostriction measurement of Δ/ ∼ 10 at a speed of 5 MHz is performed using the optical filter method as the detection scheme for the fiber Bragg grating (FBG) based strain monitor under 35-ms pulsed high magnetic fields up to 45 T at 2.2 K. The resolution of magnetostriction is about the same order as the conventionally reported value from FBG based magnetostriction measurement systems for millisecond pulsed magnetic fields.

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The specific heat of the Kondo insulator YbB_{12} has been measured up to 60 T. The Sommerfeld coefficient γ significantly increases at around 50 T, where the insulator metal transition occurs with a steep increase of the magnetization. γ reaches 67  mJ/(mol K^{2}) at high fields, which directly indicates that the quasiparticles gain a heavy thermodynamic effective mass and transform into a Kondo metal under magnetic fields.

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In this study, the case of a 46-year-old female patient with localized aortic root dissection and a superior mesenteric artery (SMA) aneurysm is described. Computed tomographic angiography could not clearly delineate an intimal flap in the aortic root, but it detected SMA aneurysm, which implied the presence of a vulnerability of the aortic wall. Finally, transesophageal echocardiography (TEE) evidently showed the intimal flap localized in the aortic root.

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A high-speed 100 MHz strain monitor using a fiber Bragg grating, an optical filter, and a mode-locked optical fiber laser has been devised, whose resolution is ΔL/L∼10. The strain monitor is sufficiently fast and robust for the magnetostriction measurements of materials under ultrahigh magnetic fields generated with destructive pulse magnets, where the sweep rate of the magnetic field is in the range of 10-100 T/μs. As a working example, the magnetostriction of LaCoO was measured at room temperature, 115 K, and 7 ∼ 4.

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A 76-year-old man who had undergone tricuspid annuloplasty 13 years earlier was admitted to our hospital because of a high fever. Although he was treated with antibiotics for pneumonia, a mild fever persisted. Computed tomography and gallium scintigraphy revealed a mediastinal abscess with an expanded polytetrafluoroethylene (ePTFE) membrane.

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Objective We evaluated the safety and efficacy of vonoprazan-based amoxicillin and clarithromycin 7-day triple therapy (VAC) in comparison to proton pump inhibitor (PPI)-based (PAC) as a first-line treatment and vonoprazan-based amoxicillin and metronidazole 7-day triple therapy (VAM) in comparison to PPI-based (PAM) as a second-line treatment for the eradication of Helicobacter pylori in Japan. Methods We performed a non-randomized, multi-center, parallel-group study to compare first-line VAC to PAC and second-line VAM to PAM. A pre-planned subgroup analysis on CAM resistance was also performed.

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Frozen elephant trunk (FET) technique combines open surgery and endovascular repair for extensive thoracic aortic aneurysms. When a FET is inserted into the descending thoracic aorta, it is difficult to confirm its proper positioning. Here we report a radiopaque ruler-guided FET technique.

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We report the case of a 73-year-old man with severe edema of the right upper extremity. Computed tomography, magnetic resonance imaging, and venography revealed an intravenous tumor in the middle portion of the right subclavian vein. The tumor was completely resected, and an accompanying thrombus was also removed using the transmanubrial osteomuscular sparing approach.

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Massive hemoptysis from an aortobronchial fistula due to thoracic aortic dissection is an extremely rare symptom, but is a potentially life-threatening condition. We report a case of acute massive hemoptysis due to aortobronchial fistula that was successfully controlled by a simple and rapid thick wedge resection of the lung with hematoma by using the black cartilage stapler. A 65-year-old man was admitted to our hospital with acute massive hemoptysis.

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The patient was a 58-year-old man with advanced gastric cancer with multiple liver metastases. He received TXL/TS-1 therapy during February 2009, but treatment was stopped immediately when he developed anorexia, diarrhea, and numbness in his fingers. Therefore, only TS-1 was administered.

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Asymptomatic rupture of a sinus of Valsalva aneurysm is rare. A fistula following rupture of a sinus of Valsalva aneurysm may cause infective endocarditis. Here, we report a case of infective endocarditis of an aorto-right atrial fistula caused by asymptomatic rupture of a sinus of Valsalva aneurysm.

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Lower limb ischemia caused by type B aortic dissection typically presents with a leg-threatening condition in the acute phase. However, in some cases, lower limb ischemia symptom develops as intermittent claudication in the chronic phase. Although surgical fenestration has been used for treating ischemic complications of aortic dissection, it has recently become an alternative option for such cases because of the significant advance of endovascular treatments.

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Objectives: We adopted an anterior longitudinal aortotomy in some cases of aortic valve replacement (AVR), and report them here. The potential of this method is also discussed.

Methods: We analyzed the data on 24 patients (75.

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Blunt vascular trauma of the lower extremities brings about a high amputation rate, because other organ injuries disturb revascularization. We experienced a case of a superficial femoral artery occlusion caused by blunt trauma. The patient also had a femoral bone fracture and a large skin defect with deep muscular injuries of the thigh.

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