著者

Hitomi Komatsu Fumio Hayashi Masahiro Sasa Koji Shikata Shigeru Yamaguchi Keiichi Namba Kenji Oosawa

出版者

一般社団法人 日本生物物理学会

雑誌

Biophysics and Physicobiology (ISSN:21894779)

巻号頁・発行日

vol.13, pp.13-25, 2016 (Released:2016-01-28)

参考文献数

81

被引用文献数

9

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FliF is the protein comprising the MS-ring of the bacterial flagellar basal body, which is the base for the assembly of flagellar axial structures. From a fliF mutant that easily releases the rod-hook-filament in viscous environments, more than 400 revertants that recovered their swarming ability in viscous conditions, were isolated. The second-site mutations were determined for approximately 70% of them. There were three regions where the mutations were localized: two in Region I, 112 in Region II, and 71 in Region III including the true reversion. In Region I, second-site mutations were found in FlgC and FlgF of the proximal rod, suggesting that they affect the interaction between the MS-ring and the rod. In Region II, there were 69 and 42 mutations in MotA and MotB, respectively, suggesting that the second-site mutations in MotA and MotB may decrease the rotational speed of the flagellar motor to reduce the probability of releasing the rod under this condition. One exception is a mutation in FlhC that caused a down regulation of the flagellar proteins production but it may directly affect transcription or translation of motA and motB. In Region III, there were 44, 24, and 3 mutations in FliG, FliM, and FliF, respectively. There were no second-site mutations identified in FliN although it is involved in torque generation as a component of the C-ring. Many of the mutations were involved in the motor rotation, and it is suggested that such reduced speeds result in stabilizing the filament attachment to the motor.

著者

Makoto MIZUSHIMA Yukitomo ISHI Hiroshi IKEDA Ikuma ECHIZENYA Takuya OTSUKA Tomoko MITSUHASHI Shigeru YAMAGUCHI Miki FUJIMURA

出版者

The Japan Neurosurgical Society

雑誌

NMC Case Report Journal (ISSN:21884226)

巻号頁・発行日

vol.9, pp.237-242, 2022-12-31 (Released:2022-07-27)

参考文献数

25

被引用文献数

5

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Methotrexate-associated lymphoproliferative disorder (MTX-LPD) occurs in patients with rheumatoid arthritis (RA) treated with methotrexate (MTX). MTX-LPD is typically associated with Epstein-Barr virus (EBV) infection and regresses with MTX discontinuation. On the other hand, EBV-negative MTX-LPDs are less common and are more likely to show partial or no regression after MTX discontinuation. There were no standard chemotherapeutic options for refractory MTX-LPD. We present a case of EBV-negative MTX-LPD in the central nervous system (CNS) that was successfully treated with rituximab, methotrexate, procarbazine, and vincristine (R-MPV), followed by reduced-dose whole-brain radiotherapy (rdWBRT), following the same treatment protocol as primary CNS lymphoma. A 59-year-old woman with RA treated with MTX presented with gradually developing staggered gait, memory deficit, and disorientation. Multiple lesions with heterogeneous contrast enhancement were discovered using brain magnetic resonance imaging. The patient was suspected of having MTX-LPD, but discontinuing MTX did not result in regression of the brain lesions. She underwent a biopsy from the left parietal lesion. The tissue was pathologically diagnosed as diffuse large B-cell lymphoma. Furthermore, pathological examination through EBV-encoded ribonucleic acid in situ hybridization demonstrated a lack of EBV infection. She was ultimately diagnosed with EBV-negative CNS MTX-LPD. We applied chemotherapy with R-MPV and rdWBRT. The patient achieved a complete response. In the case of CNS MTX-LPD without EBV infection, chemotherapy with R-MPV followed by rdWBRT may be considered.

著者

Asuka NAKAZAKI Shigeru YAMAGUCHI Hiroaki MOTEGI Yukitomo ISHI Michinari OKAMOTO Miki FUJIMURA

出版者

The Japan Neurosurgical Society

雑誌

NMC Case Report Journal (ISSN:21884226)

巻号頁・発行日

vol.9, pp.213-216, 2022-12-31 (Released:2022-07-19)

参考文献数

12

被引用文献数

1

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Facial nerve function improvement is a challenging goal in facial nerve schwannoma (FNS) surgery. Intraoperative continuous monitoring of evoked facial nerve electromyograms (CFN-EMGs) is performed in acoustic neuroma surgery to preserve facial nerve function. CFN-EMGs were applied in decompression surgery for FNS with severe facial paresis. A 39-year-old woman presented with a sudden onset of vertigo, left hearing disturbance, and severe left facial palsy with House-Brackmann (HB) grade 5. FNS was strongly suspected based on the patient's clinical course and magnetic resonance imaging findings, and the patient underwent surgical decompression of the internal auditory canal (IAC) to improve facial nerve function 9 weeks after onset. CFN-EMG responses suddenly improved after removing the posterior wall of the IAC and incising its dura matter. Since the patient's facial nerve paresis improved to HB grade 2 after surgery, CFN-EMGs could detect the moment of facial nerve decompression. This would be the first report to show that CFN-EMGs applied in decompression surgery for FNS could detect the effects of decompression during surgery in real-time. Thus, CFN-EMGs may be an effective monitoring method in decompression surgery for FNS.

著者

Shigeru YAMAGUCHI Hiroaki MOTEGI Yukitomo ISHI Michinari OKAMOTO Ryosuke SAWAYA Hiroyuki KOBAYASHI Shunsuke TERASAKA Kiyohiro HOUKIN

出版者

The Japan Neurosurgical Society

雑誌

Neurologia medico-chirurgica (ISSN:04708105)

巻号頁・発行日

pp.oa.2020-0308, (Released:2021-03-04)

参考文献数

29

被引用文献数

5

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Bevacizumab (BEV) is a key anti-angiogenic agent used in the treatment for recurrent glioblastoma multiforme (GBM). The aim of this study was to investigate whether cytoreductive surgery prior to treatment with BEV contributes to prolongation of survival for patients with recurrent GBM. We retrospectively analyzed the treatment outcomes of 124 patients with recurrent GBM who were initially treated with the Stupp protocol between 2006 and 2019. Given that BEV has only been available in Japan since 2013, we grouped the patients into two groups according to the time of first recurrence: the pre-BEV group (N = 51) included patients who had recurrence before BEV approval, and the BEV group (N = 73) included patients with recurrence after BEV approval. The overall survival after first recurrence (OS-R) was analyzed according to the treatment strategy. Among 124 patients, 27 patients (19.4%) received cytoreductive surgery. There were nine cases in the pre-BEV group and 18 cases in the BEV group. Although the mean extent of resection for both groups was almost equal, OS-R was significantly different. The median OS-R was 8.1 m in the pre-BEV group and 16.3 m in the BEV group (P = 0.007). Multivariate analysis revealed that the unavailability of BEV postoperatively (P = 0.03) and decreasing performance status by surgery (P = 0.01) were significant poor prognostic factors for survival after surgery. With the advent of BEV, cytoreductive surgery might provide superior survival benefit at the time of GBM recurrence, especially in cases where surgery can be performed without deteriorating the patient’s condition.