AN EXTENSION OF A RELIABLE WAVELENGTH COVERAGE OF THE AKARI NG GRISM MODE

Shunsuke Baba,TAKAO NAKAGAWA,NAIKI ISOBE,MAI SHIRAHATA,YOUICHI OHYAMA,KENICHI YANO,CHIHIRO KOCHI 한국천문학회 2017 天文學論叢 Vol.32 No.1

The Infrared Camera onboard the \textit{AKARI} satellite carried out spectroscopic observations with a grism mode named \textit{NG}, whose wavelength coverage was 2.5--5.0~$\mu$m. We reinvestigate the current flux calibration for the \textit{NG} grism mode, with which calculated flux density implausibly decreases at 4.9~$\mu$m especially for red objects due to the second-order light contamination. We perform a new spectral response calibration using blue and red standard objects simultaneously. New response curves which contain both the first- and second-order light are able to separate each contribution consistently and useful for studies of red objects such as CO ro-vibrational absorption in active galactic nuclei.

Clinical Factors for Prognosis and Treatment Guidance of Spinal Cord Astrocytoma

Toshitaka Seki,Kazutoshi Hida,Shunsuke Yano,Takeshi Aoyama,Izumi Koyanagi,Toru Sasamori,Shuji Hamauchi,Kiyohiro Houkin 대한척추외과학회 2016 Asian Spine Journal Vol.10 No.4

Study Design: Retrospective study. Purpose: To obtain information useful in establishing treatment guidelines by evaluating baseline clinical features and treatment outcomes of patients with spinal cord astrocytoma (SCA). Overview of Literature: The optimal management of SCA remains controversial, and there are no standard guidelines. Methods: The study included 20 patients with low-grade and 13 with high-grade SCA surgically treated between 1989 and 2014. Patients were classified according to the extent of surgical resection. Survival was assessed using Kaplan–Meier plots and compared between groups by log-rank tests. Neurological status was defined by the modified McCormick scale and compared between groups by Mann–Whitney U tests. Results: Surgical resection was performed for 19 of 20 low-grade (95%) and 10 of 13 high-grade (76.9%) SCA patients. Only nine patients (27.3%) underwent gross total resection, all of whom had low-grade SCA. Of all patients, 51.5% showed deteriorated neurological status compared to preoperative baseline. Median overall survival was significantly longer for low-grade SCA than that for high-grade SCA (91 months, 78% at 5 years vs. 15 months, 31% at 5 years; p =0.007). Low-grade SCA patients benefited from more aggressive resection, whereas high-grade SCA patients did not. Multivariate analysis revealed histology status (hazard ratio [HR], 0.30; 95% confidence interval [CI], 0.09–0.98; p <0.05) and postoperative neurological status (HR, 0.12; CI, 0.02–0.95; p <0.05) as independent predictors of longer overall survival. Adjuvant radiotherapy had no significant impact on survival rate. However, a trend for increased survival was observed with radiation cordotomy (RCT) in high-grade SCA patients. Conclusions: Aggressive resection for low-grade and RCT for high-grade SCA may prolong survival. Preservation of neurological status is an important treatment goal. Given the low incidence of SCA, establishing strong collaborative, interdisciplinary, and multiinstitutional study groups is necessary to define optimal treatments.

Surgical Outcome of Children and Adolescents with Tethered Cord Syndrome

Toshitaka Seki,Kazutoshi Hida,Shunsuke Yano,Toru Sasamori,Shuji Hamauchi,Izumi Koyanagi,Kiyohiro Houkin 대한척추외과학회 2016 Asian Spine Journal Vol.10 No.5

Study Design: Retrospective cohort study. Purpose: To compare long-term results of surgery with the outcomes of symptomatic and asymptomatic tethered cord syndrome (TCS) in children and adolescents and to assess the surgery duration for those with TCS. Overview of Literature: Pediatric patients with TCS continue to pose significant diagnostic and management challenges. Methods: We retrospectively analyzed the outcomes of 31 patients (16 males, 15 females) with TCS, including 21 with lumbosacral lipoma. All were surgically treated between 1989 and 2015. They were divided into symptomatic and asymptomatic TCS groups. The results of the treatment were summarized and analyzed using a non-parametric Mann–Whitney U test. Results: Nineteen patients had symptomatic TCS and 12 had asymptomatic TCS. Patients had a median age of 34 months (range, 0–201 months). The median follow-up period was 116 months (range, 7–223 months). Of the 19 symptomatic TCS patients, preoperative deficits improved after surgery in two (10.5%) and remained stable in 17 (89.5%) patients. One of the 12 asymptomatic TCS (8.3%) patients showed an exacerbated illness after surgery, and one in 11 patients remained stable (11.7%). There were significant differences in monthly age at surgery, preoperative bowel and bladder dysfunction, neurological function, presence/absence of clean intermittent catheterization introduction, and presence/absence of motor disorder at final follow-up (all p <0.05). In the univariate analysis, the presence/absence of preoperative bowel and bladder dysfunction, and symptoms were strongly associated with the risk of children and adolescents with TCS (p <0.05). Conclusions: Early accurate diagnosis and adequate surgical release might lead to successful outcomes in children and adolescents with TCS. Surgical untethering is a safe and effective method for treatment of children with TCS.

Surgical Outcomes of Pediatric Patients with Asymptomatic Tethered Cord Syndrome

Toshitaka Seki,Kazutoshi Hida,Shunsuke Yano,Kiyohiro Houkin 대한척추외과학회 2018 Asian Spine Journal Vol.12 No.3

Study Design: A retrospective cohort study. Purpose: To examine the validity of prophylactic surgery for children with tethered cord syndrome (TCS). Overview of Literature: Prophylactic surgery for pediatric patients with TCS remains controversial. Methods: We retrospectively analyzed the surgical outcomes of 14 children (nine boys and five girls) with asymptomatic TCS who were surgically treated at Hokkaido University Hospital between 1989 and 2015. Results: The median age at the time of initial surgery for asymptomatic TCS was 28.6 months (range, 0–66 months). The median final follow-up period was 142 months (range, 7–232 months). Of the 14 children with asymptomatic TCS, 12 had lumbosacral lipoma and two had meningocele. According to the classification of spinal lipoma, two children had dorsal type, four had caudal type, two had transitional type, and four had filar type. There were no children with lipomyelomeningocele. All children were free of neurological symptoms until 94 months after the initial surgery. Subsequently, one child exhibited delayed neurological deficits and underwent a second surgery because of motor and sensory disturbances; slight sensory disturbance was noted at the final follow-up examination. Another child later showed bowel and bladder dysfunction. However, a second surgery was not performed for this child because his motor and sensory functions were normal; hence, we chose to avoid nerve injury in the case of dissecting adhesion. Conclusions: All 14 children with asymptomatic TCS were free of neurological symptoms until 94 months after the initial surgery. However, two children exhibited delayed neurological deficits at 94 months and 177 months. We believe that prophylactic surgery for asymptomatic TCS is effective for a certain period. However, because the natural history of TCS is poorly understood, strict follow-up after surgery is necessary.

INFRARED – X-RAY CONNECTION IN NEARBY ACTIVE GALACTIC NUCLEI; AKARI AND MAXI RESULTS

Naoki Isobe,TAKAONAKAGAWA,Kenichi Yano,Shunsuke Baba,SHINKI OYABU,Yoshiki Toba,Yoshihiro Ueda,Taiki Kawamuro 한국천문학회 2017 天文學論叢 Vol.32 No.1

Combining the AKARI Point Source Catalog andthe 37-month Monitor of All-sky X-ray Image (MAXI) catalog,the infrared and X-ray properties of nearby active galactic nucleiwere investigated. The 37-month MAXI catalog tabulates 100 nearby Seyfert galaxies,73 of which are categorized into Seyfert I galaxies. Among these Seyfert galaxies,69 ones were found to have an AKARI infrared counterpart. For the Seyfert I galaxies in this sample,a well-known correlation was found between the infrared and X-ray luminosities. However, the observed X-ray luminosity of the Seyfert II galaxiestends to be lower for the infrared luminosity than the Seyfert I galaxies. This suggests thatthe X-ray absorption is significant in the Seyfert II galaxies. The Seyfert II galaxies seem to havea bimodal distribution of the IR color between $18~\mu$m and $90~\mu$m. Especially, a large fraction of the Seyfert II galaxiesexhibits a redder IR color than the Seyfert I galaxies. A possible origin of the redder IR color is briefly discussed,in relation to the star formation activity in the host galaxy,and to the X-ray absorption.

First Two Cases of Infected Aortic Aneurysm Caused by Non-Vaccine Streptococcus pneumoniae Serotype 23A

Risako Kakuta,Ryuichi Nakano,Hisakazu Yano,Daiki Ozawa,Nobuo Ohta,Takayuki Matsuoka,Naotaka Motoyoshi,Shunsuke Kawamoto,Yoshikatsu Saiki,Yukio Katori,Mitsuo Kaku 대한진단검사의학회 2020 Annals of Laboratory Medicine Vol.40 No.3

Dear Editor, Infected aortic aneurysm (IAA) is an uncommon, but life-threatening condition. Identification of the causative pathogen is essential for accurate diagnosis and effective treatment. However, 14–40% of IAA cases are culture-negative [1]. IAA due to Streptococcus pneumoniae is rare, and reports of the involvement of S. pneumoniae capsular serotypes and sequence types (STs) in IAA are even rarer [2-5]. We identified S. pneumoniae from culture-negative IAA by genetic analysis. To the best of our knowledge, as of 2019, only 59 cases of pneumococcal IAA have been reported in France, the United Kingdom (UK), the Netherlands, Germany, Switzerland, Belgium, Denmark, the United States (USA), Canada, Chile, Japan, Hong Kong, Korea, and Austria since 1977 [2-5]. In the previous cases of IAA due to S. pneumoniae, capsular serotype analysis was reported only for seven: 10A and 23F in the UK, 4 and 8 in Denmark, 19F in Hong Kong, 4 in Belgium, and 23 in USA [2-5]. We report the first two cases of culture-negative IAA due to non-vaccine S. pneumoniae serotype 23A, ST338. The study protocol was approved by the Institutional Ethics Committees of Tohoku University, Sendai, Japan (No. 2018-1-456).

Efficacy of Two-Stage Surgery for Spinal Cord Ependymomas

Takamiya Soichiro,Seki Toshitaka,Yamazaki Kazuyoshi,Yano Shunsuke,Hida Kazutoshi 대한척추외과학회 2022 Asian Spine Journal Vol.16 No.4

Study Design: Retrospective cohort study.Purpose: This study aimed to elucidate cases for which staged surgeries are effective by a retrospective review of previous operative cases of spinal ependymomas.Overview of Literature: Patients with spinal ependymomas are expected to have a good prognosis following total resection. However, forcible dissection of spinal ependymomas will lead to neurological deterioration. Moreover, resection is sometimes difficult when the tumor is large. We have performed two-stage surgeries for large spinal ependymomas, but the indication of staged surgery is unclear.Methods: We retrospectively reviewed patients diagnosed with spinal ependymomas who underwent tumor resection in our institution. We obtained data regarding patients’ clinical characteristics, tumoral radiological characteristics, and surgical factors and compared them to clear prognostic factors. Two-stage surgery was performed in 11 patients (36.7%), and single surgery was performed in 19 patients (63.3%).Results: Thirty patients were included in the analyses and divided into two groups: single surgery and two-stage surgery groups. In the single surgery group, high tumor–cord ratio (TCR) and intraoperative motor evoked potential (MEP) reduction were significantly correlated with unfavorable outcomes, which were defined as deterioration of the modified McCormick scale grades 2 months and 1 year postoperatively. Alternatively, these factors were not significantly correlated with postoperative unfavorable outcomes in the two-stage surgery group. Receiver operating characteristic curves indicated that TCR of 0.866 yielded 85.7% sensitivity and 83.3% specificity 2 months postoperatively.Conclusions: The results suggested that high TCR might be an indication of two-stage surgery and that its cutoff value is 0.866. Moreover, switching from single surgery to two-stage surgery may prevent postoperative neurological deterioration when intraoperative MEP is decreasing.

Investigation of the Neuropathic Pain Caused by Syringomyelia Associated with Chiari I Malformation

Toshitaka Seki,Shuji Hamauchi,Masayoshi Yamazaki,Kazutoshi Hida,Shunsuke Yano,Kiyohiro Houkin 대한척추외과학회 2019 Asian Spine Journal Vol.13 No.4

Study Design: Retrospective cohort study. Purpose: To investigate the correlation between the syrinx morphology and neuropathic pain caused by syringomyelia associated with Chiari I malformation. Overview of Literature: Neuropathic pain caused by syringomyelia is refractory and markedly impairs the patient. Methods: We examined 24 patients with neuropathic pain caused by syringomyelia associated with Chiari I malformation. We statistically analyzed the illness duration and age at surgery between patients with and without neuropathic pain. Additionally, we classified the morphology of the syringes into deviated (D), enlarged (E), central (C), and bulkhead (B) types using T2-weighted axial imaging. Moreover, we investigated the correlation between syrinx morphology and neuropathic pain. A Mann–Whitney U-test was performed to compare between the presence or absence of neuropathic pain and the presence or absence of type D syringes. Results: The median age at surgery was 27.5 years, and the median illness duration was 24 months. Among the 24 patients, 11 had preoperative neuropathic pain, one of which was free of neuropathic pain during the final follow-up period. Among patients with neuropathic pain, the syringes’ preoperative morphology was type D in nine patients and types E and C in one patient each. No patient exhibited type B morphology. Among patients without neuropathic pain, the preoperative morphology of the syringes was type D in three patients, type E in seven patients, and types C and B in two patients each. For types D and E, a correlation between neuropathic pain and syrinx morphology was observed. Moreover, type D was associated with significant neuropathic pain in both preoperative and postoperative states. Conclusions: This study showed a correlation between the morphological features of the syringes and the occurrence of neuropathic pain in patients with syringomyelia associated with Chiari I malformation.

STUDY OF SPECTRAL ENERGY DISTRIBUTION OF GALAXIES WITH PRINCIPAL COMPONENT ANALYSIS

Chihiro Kochi,TAKAO NAKAGAWA,Naoki Isobe,MAI SHIRAHATA,Kenichi Yano,Shunsuke Baba 한국천문학회 2017 天文學論叢 Vol.32 No.1

We performed Principle Component Analysis\,(PCA) over 264 galaxies in the {\it IRAS} Revised Bright Galaxy \blue{Sample \citep{Sanders2003}} using 12, 25, 60 and 100\,$\mu$m flux data observed by {\it IRAS} and 9, 18, 65, 90 and 140\,$\mu$m flux data observed by {\it AKARI}. We \blue{found} that (i)the first principle component \blue{was} largely contributed by infrared to visible flux ratio, (ii)the second principal component \blue{was} largely contributed by the flux ratio between {\it IRAS} and {\it AKARI}, (iii)the third principle component \blue{was} largely contributed by infrared colors.