297 results on '"Keitaro Takahashi"'
Search Results
2. Safety and real-world efficacy of lemborexant in the treatment of comorbid insomnia
- Author
-
Narimasa Katsuta, Keitaro Takahashi, Yui Kurosawa, Akane Yoshikawa, Yoshihide Takeshita, Yoshihiro Uchida, Seita Yasuda, Chihiro Kakiuchi, Masanobu Ito, and Tadafumi Kato
- Subjects
Lemborexant ,Comorbid insomnia ,Benzodiazepines ,Z-drug ,Specialties of internal medicine ,RC581-951 - Abstract
Aim: To investigate the real-world effectiveness and safety of lemborexan for treating comorbid insomnia associated with other psychiatric disorders, and whether lemborexant helps reduce the dose of benzodiazepines (BZs). Methods: This retrospective observational study was conducted on outpatients and inpatients treated by physicians of Juntendo University Hospital Mental Clinic between April 2020 and December 2021. Results: Data of 649 patients who were treated with lemborexant were eventually enrolled. About 64.5% of patients were classified as the responder group. Response rates of ≥60% were recorded for most psychiatric disorders. Upon administration of lemborexant, diazepam-equivalent dose of BZs had been significantly reduced in participants (3.7 ± 8.2 vs. 2.9 ± 7.9, p
- Published
- 2023
- Full Text
- View/download PDF
3. Testis‐specific hnRNP is expressed in colorectal cancer cells and accelerates cell growth mediating ZDHHC11 mRNA stabilization
- Author
-
Yuki Murakami, Hiroaki Konishi, Mikihiro Fujiya, Keitaro Takahashi, Katsuyoshi Ando, Nobuhiro Ueno, Shin Kashima, Kentaro Moriichi, Hiroki Tanabe, and Toshikatsu Okumura
- Subjects
ATM ,ATR ,colorectal cancer ,hnRNP G‐T ,ZDHHC11 ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Abstract Various heterogeneous nuclear ribonucleoproteins (hnRNPs) have been reported to be associated with cancer cell growth. However, it remains unclear whether hnRNP G‐T, which is specifically expressed in the testis, is expressed in tumor cells, and whether hnRNP G‐T expressed in colorectal cancer (CRC) cells is associated with tumor progression. We herein report that hnRNP G‐T promoted cancer cell growth and stabilized mRNA of ZDHHC11 in CRC. The cell growth was inhibited by transfection of siRNA of hnRNP G‐T in cancer cells, but not in non‐cancerous epithelial cells. The tumor promotive effect of hnRNP G‐T was confirmed in an HCT116 transplanted mouse model. RT‐PCR and western blotting indicated the augmentation of hnRNP G‐T in CRC in comparison to non‐cancerous cells. The downregulation of hnRNP G‐T inhibited cancer cell growth and promoted apoptosis in CRC. A transcriptome analysis combined with immunoprecipitation revealed that hnRNP G‐T stabilized 174 mRNAs, including ZDHHC11 mRNA. The cell growth was also suppressed by the transfection of siRNA of ZDHHC11 and the mRNA and the protein expression were decreased by the transfection of siRNA of hnRNP G‐T. These results suggested that hnRNP G‐T promotes the cell growth of CRC by regulating the mRNA of ZDHHC11. Therefore, hnRNP G‐T will be highlighted as an effective therapeutic target with less adverse effects in CRC therapy.
- Published
- 2022
- Full Text
- View/download PDF
4. Endoscopic recanalization for the complete closure of long-gap esophageal atresia after reconstruction surgery
- Author
-
Shin Kashima, Kentaro Moriichi, Yu Kobayashi, Yuya Sugiyama, Yuki Murakami, Takahiro Sasaki, Keitaro Takahashi, Katsuyoshi Ando, Nobuhiro Ueno, Hiroki Tanabe, and Mikihiro Fujiya
- Subjects
Long-gap esophageal atresia ,Complete esophageal closure ,Puncture needle ,Endoscopic recanalization ,Diseases of the digestive system. Gastroenterology ,RC799-869 - Abstract
Abstract Background Reconstruction surgery-associated stricture frequently occurs in patients with long-gap esophageal atresia (LGEA). While several endoscopic dilatation methods have been applied and would be desirable, endoscopic recanalization is very difficult in cases with complete esophageal closure. Surgical treatment has been performed for a severe stricture, which causes extensive damage to the infant. No reports have described successful endoscopic recanalization for complete closure due to scarring after surgery for LGEA. We herein report the case of successful endoscopic recanalization by single endoscopist in an LGEA patient with complete closure after reconstruction surgery. Case presentation A seven-month-old boy with LGEA who received reconstruction surgery and gastrostomy immediately after birth presented to our unit due to vomiting and malnutrition. Contrast radiography and peroral endoscopy detected complete closure of the esophagus at the anastomotic site. After confirming the length of stricture as several millimeters, we punctured the center of the lumen with a 25-G puncture needle under fluoroscopy. An endoscope was then inserted via the gastrostomy and the puncture hole was detected at the center of the lumen. After passing the guidewire, endoscopic balloon dilation was performed three times, and the hole was sufficiently dilatated. Oral ingestion was feasible, and his nutritional condition was improved. Conclusions To our knowledge, this is the first report to propose a less invasive endoscopic approach to recanalize a site of complete esophageal closure in a LGEA patient after reconstruction surgery by single endoscopist. Our endoscopic procedure using an ultrathin endoscope and puncture needle may be a therapeutic option for the treatment of patients with complete esophageal closure in a LGEA patient after reconstruction surgery.
- Published
- 2022
- Full Text
- View/download PDF
5. Prognostic factors to predict the survival in patients with advanced gastric cancer who receive later‐line nivolumab monotherapy—The Asahikawa Gastric Cancer Cohort Study (AGCC)
- Author
-
Kazuyuki Tanaka, Hiroki Tanabe, Hiroki Sato, Chisato Ishikawa, Mitsuru Goto, Naoyuki Yanagida, Hiromitsu Akabane, Shiro Yokohama, Kimiharu Hasegawa, Yohei Kitano, Yuya Sugiyama, Kyoko Uehara, Yu Kobayashi, Yuki Murakami, Takehito Kunogi, Takahiro Sasaki, Keitaro Takahashi, Katsuyoshi Ando, Nobuhiro Ueno, Shin Kashima, Kentaro Moriichi, Keisuke Sato, Sayaka Yuzawa, Mishie Tanino, Masaki Taruiishi, Yasuo Sumi, Yusuke Mizukami, Mikihiro Fujiya, and Toshikatsu Okumura
- Subjects
biomarker ,chemotherapy ,gastric carcinoma ,microsatellite instability ,nomogram ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Abstract Background Chemotherapy for advanced gastric cancer is recommended in the guidelines; however, later‐line treatment remains controversial. Since immune checkpoint inhibitors have been used for the treatment of various malignancies, trials have been performed for gastric cancer. A phase 3 trial indicated the survival benefit of nivolumab monotherapy for gastric cancer patients treated with prior chemotherapy regimens. Patients and methods A regional cohort study was undertaken to determine the real‐world data of nivolumab treatment for patients with advanced or recurrent gastric cancer. The patients were enrolled for 2 years from October 2017 to October 2019 and were prospectively followed for 1 year to examine the overall survival (OS). The patient characteristics were analyzed in a multivariate analysis and a nomogram to predict the probability of survival was generated. Results In total, 70 patients who received nivolumab as ≥third‐line chemotherapy were included in the Asahikawa Gastric Cancer Cohort. The median OS was 7.5 (95% CI, 4.8–10.2) months and the response rate was 18.6%. Diffuse type classification, bone metastasis, high neutrophil/lymphocyte ratio, and high CRP were associated with poor OS/prognosis in the multivariate analysis. A nomogram was developed based on these clinical parameters and the concordance index was 0.80 (95% CI, 0.68–0.91). The responders were aged and were frequently diagnosed with intestinal type gastric cancer, including patients with a HER2‐positive status (27.3%) or microsatellite instability‐high (27.3%) status. Conclusions The regional cohort study of nivolumab monotherapy for gastric cancer patients revealed prognostic factors and a nomogram was developed that could predict the probability of survival.
- Published
- 2022
- Full Text
- View/download PDF
6. Fecal calprotectin is a useful biomarker for predicting the clinical outcome of granulocyte and monocyte adsorptive apheresis in ulcerative colitis patients: a prospective observation study
- Author
-
Nobuhiro Ueno, Yuya Sugiyama, Yu Kobayashi, Yuki Murakami, Takuya Iwama, Takahiro Sasaki, Takehito Kunogi, Keitaro Takahashi, Kazuyuki Tanaka, Katsuyoshi Ando, Shin Kashima, Yuhei Inaba, Kentaro Moriichi, Hiroki Tanabe, Masaki Taruishi, Yusuke Saitoh, Toshikatsu Okumura, and Mikihiro Fujiya
- Subjects
Fecal calprotectin ,Ulcerative colitis ,Biomarker ,Granulocyte/Monocyte Apheresis (GMA) ,Endoscopic remission ,Clinical remission ,Diseases of the digestive system. Gastroenterology ,RC799-869 - Abstract
Abstract Background Granulocyte and monocyte adsorptive apheresis (GMA) is widely used as a remission induction therapy for active ulcerative colitis (UC) patients. However, there are no available biomarkers for predicting the clinical outcome of GMA. We investigated the utility of Fecal calprotectin (FC) as a biomarker for predicting the clinical outcome during GMA therapy in active UC patients. Methods In this multicenter prospective observation study, all patients received 10 sessions of GMA, twice a week, for 5 consecutive weeks. FC was measured at entry, one week, two weeks, and at the end of GMA. Colonoscopy was performed at entry and after GMA. The clinical activity was assessed based on the partial Mayo score when FC was measured. Clinical remission (CR) was defined as a partial Mayo score of ≤ 2 and endoscopic remission (ER) was defined as Mayo endoscopic subscore of either 0 or 1. We analyzed the relationships between the clinical outcome (CR and ER) and the change in FC concentration. Result Twenty-six patients were included in this study. The overall CR and ER rates were 50.0% and 19.2%, respectively. After GMA, the median FC concentration in patients with ER was significantly lower than that in patients without ER (469 mg/kg vs. 3107 mg/kg, p = 0.03). When the cut-off value of FC concentration was set at 1150 mg/kg for assessing ER after GMA, the sensitivity and specificity were 0.8 and 0.81, respectively. The FC concentration had significantly decreased by one week. An ROC analysis demonstrated that the reduction rate of FC (ΔFC) at 1 week was the most accurate predictor of CR at the end of GMA (AUC = 0.852, P = 0.002). When the cut-off value of ΔFC was set at ≤ 40% at 1 week for predicting CR at the end of GMA, the sensitivity and specificity were 76.9% and 84.6%, respectively. Conclusion We evaluated the utility of FC as a biomarker for assessing ER after GMA and predicting CR in the early phase during GMA in patients with active UC. Our findings will benefit patients with active UC by allowing them to avoid unnecessary invasive procedures and will help establish new strategies for GMA.
- Published
- 2021
- Full Text
- View/download PDF
7. Clinicopathological characteristics of Epstein–Barr virus and microsatellite instability subtypes of early gastric neoplasms classified by the Japanese and the World Health Organization criteria
- Author
-
Hiroki Tanabe, Yusuke Mizukami, Hidehiro Takei, Nobue Tamamura, Yuhi Omura, Yu Kobayashi, Yuki Murakami, Takehito Kunogi, Takahiro Sasaki, Keitaro Takahashi, Katsuyoshi Ando, Nobuhiro Ueno, Shin Kashima, Sayaka Yuzawa, Kimiharu Hasegawa, Yasuo Sumi, Mishie Tanino, Mikihiro Fujiya, and Toshikatsu Okumura
- Subjects
early gastric cancer ,gastric dysplasia ,carcinogenesis ,Pathology ,RB1-214 - Abstract
Abstract Gastric cancer is a heterogenous disease with different phenotypes, genotypes, and clinical outcomes, including sensitivity to treatments and prognoses. Recent medical advances have enabled the classification of this heterogenous disease into several groups and the consequent analysis of their clinicopathological characteristics. Gastric cancer associated with Epstein–Barr virus (EBV) and microsatellite‐unstable tumors are considered to be the two major subtypes as they are clearly defined by well‐established methodologies, such as in situ hybridization and polymerase chain reaction‐based analyses, respectively. However, discrepancies in the histological diagnosis of gastric neoplasms remain problematic, and international harmonization should be performed to improve our understanding of gastric carcinogenesis. We re‐evaluated Japanese cases of early gastric cancer according to the current World Health Organization (WHO) criteria and classified them into genomic subtypes based on microsatellite instability (MSI) and EBV positivity to determine the initial genetic events in gastric carcinogenesis. A total of 113 Japanese early gastric cancers (including low‐ and high‐grade dysplasias) treated with endoscopic resection over 5 years were archived in our hospital. A histological re‐evaluation according to the WHO criteria revealed 54 adenocarcinomas, which were divided into 6 EBV‐positive (11.1%), 7 MSI‐high (MSI‐H, 13.0%), and 41 microsatellite stable cases (75.9%). MSI‐H adenocarcinoma was confirmed by an immunohistochemistry assay of mismatch repair proteins. Programmed death‐ligand 1 immunostaining with two antibodies (E1L3N and SP263) was positive in tumor cells of one MSI‐H adenocarcinoma case (1/7, 14.3%). The proportion of stained cells was higher with clone SP263 than with E1L3N. Histologically, EBV‐positive carcinomas were poorly differentiated (83.8%), and MSI‐H cancers were frequent in well to moderately differentiated adenocarcinoma (85.7%), indicating that the EBV‐positive subtype presented with high‐grade morphology even when an early lesion. Our study indicates that the WHO criteria are useful for subdividing Japanese early gastric cancers, and this subdivision may be useful for comparative analysis of precursor lesions and early carcinoma.
- Published
- 2021
- Full Text
- View/download PDF
8. Severe immune checkpoint inhibitor-associated gastritis: A case series and literature review
- Author
-
Yuya Sugiyama, Hiroki Tanabe, Taisuke Matsuya, Yu Kobayashi, Yuki Murakami, Takahiro Sasaki, Takehito Kunogi, Keitaro Takahashi, Katsuyoshi Ando, Nobuhiro Ueno, Shin Kashima, Kentaro Moriichi, Mishie Tanino, Yusuke Mizukami, Mikihiro Fujiya, and Toshikatsu Okumura
- Subjects
Diseases of the digestive system. Gastroenterology ,RC799-869 - Abstract
Background and study aims Recent advances in cancer treatment have involved the clinical application of immune checkpoint inhibitors (ICIs) for various type of cancers. The adverse events associated with ICIs are generally referred to as immune-related adverse events (irAEs). Gastrointestinal irAEs are a major disorder, but gastritis is not frequently observed. The aims of this study were to elucidate the clinical, endoscopic, and histological characteristics of irAE gastritis. Patients and methods Information on patients treated with ICIs were collected from a single institute over 3 years. IrAE gastritis was identified based on the clinical course and endoscopic and histopathological findings. Of the 359 patients treated with ICIs, four cases of irAE gastritis were identified in clinical records from the endoscopy unit. The endoscopic and histopathological findings were analyzed, and further immunohistochemical studies with immune subtype markers and programmed cell death ligand-1 (PD-L1) antibody were conducted. Results Among four patients with irAE gastritis, the remarkable endoscopic characteristics were network-pattern erosion, erythematous and edematous mucosa with thick purulent discharge, and fragile mucosa. Corresponding histological features were fibrinopurulent exudate, severe inflammatory cell infiltration, and epithalaxia, respectively. The PD-L1 expression rate was ≥ 1 % in the gastric tissue of all patients with gastritis. These patients were treated with prednisolone (PSL) and their symptoms improved within a few days to 2 weeks. Conclusions IrAE gastritis were characterized by specific endoscopic findings. The appropriate endoscopic diagnosis may lead to effective treatment with PSL.
- Published
- 2022
- Full Text
- View/download PDF
9. Bacteria‐derived ferrichrome inhibits tumor progression in sporadic colorectal neoplasms and colitis‐associated cancer
- Author
-
Takuya Iwama, Mikihiro Fujiya, Hiroaki Konishi, Hiroki Tanaka, Yuki Murakami, Takehito Kunogi, Takahiro Sasaki, Keitaro Takahashi, Katsuyoshi Ando, Nobuhiro Ueno, Shin Kashima, Kentaro Moriichi, Hiroki Tanabe, and Toshikatsu Okumura
- Subjects
Ferrichrome ,Organoid ,Colorectal cancer ,Probiotics ,DDIT3 ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 ,Cytology ,QH573-671 - Abstract
Abstract Background Colorectal cancers develop through several pathways, including the adenoma–carcinoma sequence and colitis-associated carcinogenesis. An altered intestinal microflora has been reported to be associated with the development and progression of colorectal cancer via these pathways. We identified Lactobacillus casei-derived ferrichrome as a mediator of the bacterial anti-tumor effect of colorectal cancer cells through the upregulation of DDIT3. In this study, we investigated the anti-tumor effects of ferrichrome on precancerous conditions and cancer cells associated with sporadic as well as colitis-associated colorectal cancer. Methods SRB and MTT assays were performed to assess growth inhibition in vitro. Eighteen organoids were prepared from biopsy specimens obtained by colonoscopy. An AOM-DSS carcinogenesis model and xenograft model of colorectal cancer cells were generated for the assessment of the tumor suppressive effect of ferrichrome in vivo. Results Ferrichrome inhibited the cell growth of colorectal cancer cells in vitro and in in vivo xenograft models. Ferrichrome exerted a strong tumor-suppressive effect that was superior to that of currently available anti-tumor agents, including 5-FU and cisplatin, both in vitro and in vivo. The tumor-suppressive effect of the combination of ferrichrome and 5-FU was superior to that of single treatment with either drug. The tumor suppressive effects of ferrichrome were confirmed through the upregulation of DDIT3 in patient-derived organoids of adenoma and carcinoma. Ferrichrome inhibited the tumor progression in the AOM-DSS model while exhibiting no anti-inflammatory effect in the DSS-colitis model, suggesting that ferrichrome inhibited cancer cells, but not a precancerous condition, via the colitis-associated pathway. Conclusions Ferrichrome exerts a tumor suppressive effect on precancerous conditions and cancer cells associated with sporadic as well as colitis-associated colorectal cancer. The anti-tumor effect of ferrichrome was mediated by the upregulation of DDIT3, and was superior to that of 5-FU or cisplatin. These results suggest that Lactobacillus brevis-derived ferrichrome may be a candidate anti-tumor drug for the treatment of colorectal neoplasms.
- Published
- 2021
- Full Text
- View/download PDF
10. Correlation Among Body Composition Parameters and Long-Term Outcomes in Crohn's Disease After Anti-TNF Therapy
- Author
-
Katsuyoshi Ando, Kyoko Uehara, Yuya Sugiyama, Yu Kobayashi, Yuki Murakami, Hiroki Sato, Takehito Kunogi, Takahiro Sasaki, Keitaro Takahashi, Nobuhiro Ueno, Shin Kashima, Kentaro Moriichi, Hiroki Tanabe, Toshikatsu Okumura, and Mikihiro Fujiya
- Subjects
Crohn's disease ,body composition ,skeletal muscle ,visceral fat ,mesenteric fat index ,anti-TNF antibody ,Nutrition. Foods and food supply ,TX341-641 - Abstract
BackgroundThe impact of the body composition on the pathophysiology and clinical course of Crohn's disease (CD) has not been fully elucidated.AimsTo reveal the correlations among body composition and long-term outcomes in CD after anti-TNF therapy.MethodsNinety-one patients who received anti-TNF therapy as their first biologic treatment were enrolled. The skeletal muscle index (SMI), visceral and subcutaneous fat area (VFA, SFA), and the ratio of the VFA to SFA (mesenteric fat index; MFI) at the 3rd lumbar level were measured using computed tomography (CT) imaging before the induction. The correlation among the body composition and outcomes were retrospectively analyzed.ResultsThe 5-year cumulative secondary failure- and resection-free rates in patients with a low SMI (39.1% and 64.8%) were significantly lower than those with a high SMI (67.5% and 92.7%; p = 0.0071 and 0.0022, respectively). The 5-year cumulative secondary failure-free rate in the patients with low VF (45.0%) was significantly lower than that in those with high VF (77.6%; p = 0.016), and the 5-year cumulative resection-free rate in patients with a high MFI (68.9%) was significantly lower than that in those with a low MFI (83.0%; p = 0.031). Additionally, patients with low age and BMI had significantly lower cumulative secondary failure- and resection-free rates than those with high age and BMI (low age: 37.4% and 71.2%; high age: 70.7% and 88.9%; p = 0.0083 and 0.027, respectively) (low BMI: 27.2% and 64.8%; high BMI: 68.3% and 87.9%; p = 0.014 and 0.030, respectively), respectively. In the multivariate analyses, a low SMI was the only independent risk factor for secondary failure (hazard ratio [HR] 2.15, 95% confidence interval [CI] 1.04–4.44), while low age (HR 4.06, 95% CI 1.07–15.4), a low SMI (HR 4.19, 95% CI 1.01–17.3) and high MFI were risk factors for bowel resection (HR 4.31, 95% CI 1.36–13.7).ConclusionThe skeletal muscle mass and ratio of visceral to subcutaneous fat were suggested to reflect the long-term clinical outcome and may be helpful as prognostic markers after anti-TNF therapy in CD.
- Published
- 2022
- Full Text
- View/download PDF
11. Fluoride Ion Conductive Polymer Electrolytes for All-solid-state Fluoride Shuttle Batteries
- Author
-
Keitaro TAKAHASHI, Atsuya YOKOO, Yukari KANEKO, Takeshi ABE, and Shiro SEKI
- Subjects
fluoride shuttle battery ,all-solid-state battery ,solid polymer electrolyte ,transference number ,Technology ,Physical and theoretical chemistry ,QD450-801 - Abstract
To control the fluoride dissociation and conduction of polyether-based solid polymer electrolytes, an electrolyte system composed of a host polymer, metal salt, and anion acceptor was proposed. Appropriate choices of metal salt with low lattice enthalpy and anion acceptor concentration were important to obtain polymer electrolytes with high fluoride conductivity. The results of thermal and electrochemical measurements revealed that the optimal electrolyte system displayed a relatively high fluoride conductivity of ca. 1 × 10−6 S cm−1 at 303 K and fluoride transference number of over 0.8 (80%).
- Published
- 2020
- Full Text
- View/download PDF
12. Investigation for Charge-Discharge Operations of Li4Ti5O12-Sulfur Batteries by Suitable Choice of Materials and Cell Preparation Processes
- Author
-
Kazuki MACHIDA, Hibiki MIYAUCHI, Yusuke USHIODA, Keitaro TAKAHASHI, and Shiro SEKI
- Subjects
lithium-sulfur battery ,stable electrode ,pre-doping of reactive ionic species ,Technology ,Physical and theoretical chemistry ,QD450-801 - Abstract
To achieve stable charge-discharge operations of Li-S batteries, [Li4Ti5O12 | sulfurized polyacrylonitrile (SPAN)] cells treated with a Li pre-doping process were prepared by two different techniques. Several different materials were studied without encountering any difficult barriers, and the obtained cells exhibited suitable charge-discharge operations with high efficiency.
- Published
- 2022
- Full Text
- View/download PDF
13. Genetic alteration of colorectal adenoma‐carcinoma sequence among gastric adenocarcinoma and dysplastic lesions in a patient with attenuated familial adenomatous polyposis
- Author
-
Hiroki Tanabe, Kentaro Moriichi, Keitaro Takahashi, Yusuke Ono, Yu Kobayashi, Yuki Murakami, Takuya Iwama, Takehito Kunogi, Takahiro Sasaki, Katsuyoshi Ando, Nobuhiro Ueno, Shin Kashima, Hidehiro Takei, Yusuke Mizukami, Mikihiro Fujiya, and Toshikatsu Okumura
- Subjects
endoscopic submucosal dissection ,fundic gland polyp ,gastric cancer ,next‐generation sequencing ,somatic mutation ,Genetics ,QH426-470 - Abstract
Abstract Background Familial adenomatous polyposis (FAP) is characterized by colorectal polyposis and adenocarcinoma that is frequently accompanied by extracolonic neoplasm. The risk of gastric carcinoma is increasing in Western FAP patients as well as Asian patients. Methods We report the case of an FAP patient with fundic gland polyposis who developed gastric adenocarcinoma and metachronous pyloric gland adenomas. These tumors were endoscopically resected, and immunohistochemistry with gastric mucin (i.e., MUC6, MUC5AC) showed that the tumors belonged to the gastric subtype. Somatic mutation profiles were determined by target amplicon sequencing using a next‐generation sequencer. Results Germline APC variant c.5782delC was found by direct sequencing and somatic KRAS mutations in these tumors were identified by next‐generation sequencing. Different KRAS mutation alleles (KRAS p.Gly12Ala, p.Gly12Arg, and p.Gly12Asp) indicated these dysplastic lesions developed from a distinct origin in fundic gland polyposis. Sequential mutations of the APC and KRAS were judged—based on a database search—to be characteristic of the adenoma‐carcinoma sequence in colorectal carcinogenesis. Conclusion The colonic adenoma‐carcinoma sequence among gastric adenocarcinoma and dysplastic lesions was indicated in FAP‐associated gastric carcinogenesis.
- Published
- 2020
- Full Text
- View/download PDF
14. Lymph Node Metastasis From Gastroesophageal Cancer Successfully Treated by Nivolumab: A Case Report of a Young Patient
- Author
-
Shin Kashima, Hiroki Tanabe, Mishie Tanino, Yu Kobayashi, Yuki Murakami, Takuya Iwama, Takahiro Sasaki, Takehito Kunogi, Keitaro Takahashi, Katsuyoshi Ando, Nobuhiro Ueno, Kentaro Moriichi, Masahide Fukudo, Yoshikazu Tasaki, Masao Hosokawa, Yusuke Mizukami, Mikihiro Fujiya, and Toshikatsu Okumura
- Subjects
gastric cancer ,immunotherapy ,complete remission (CR) ,tumor burden ,lymph node metastasis (LNM) ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Background: Immuno-oncology is a novel target of cancer therapy. Nivolumab is a monoclonal anti-programed death-1 antibody recently used to treat patients with chemotherapy-resistant gastric and gastroesophageal cancer. Although the disease control rate is reported to be very high, few cases demonstrate a complete response.Case Presentation: A 25-year-old man diagnosed with gastroesophageal cancer was treated with chemotherapy followed by surgical resection. Pathological diagnosis was poorly differentiated adenocarcinoma with distant lymph node metastasis. Residual lymph node metastasis was treated with nivolumab monotherapy, resulting in complete disappearance. No recurrence has been observed for 2 years since discontinuation of nivolumab. This rare case was additionally subjected to pathological and genetic analysis, suggesting that a high tumor mutation burden (10.7 mutations/Mb) might be associated with sensitivity to nivolumab.Summary: We reported a case of advanced gastroesophageal junction cancer with distal lymph node metastasis that was successfully treated with chemotherapy, surgical resection, and nivolumab therapy. An aggressive search for biomarkers implying benefit effects of nivolumab should be performed.
- Published
- 2019
- Full Text
- View/download PDF
15. The incidence and risk factors of venous thromboembolism in Japanese inpatients with inflammatory bowel disease: a retrospective cohort study
- Author
-
Katsuyoshi Ando, Mikihiro Fujiya, Yoshiki Nomura, Yuhei Inaba, Yuuya Sugiyama, Takuya Iwama, Masami Ijiri, Keitaro Takahashi, Kazuyuki Tanaka, Aki Sakatani, Nobuhiro Ueno, Shin Kashima, Kentaro Moriichi, Yusuke Mizukami, and Toshikatsu Okumura
- Subjects
Venous thromboembolism ,Inflammatory bowel disease ,Risk factors ,Medicine ,Diseases of the digestive system. Gastroenterology ,RC799-869 - Abstract
Background/AimsVenous thromboembolism (VTE) is a major extraintestinal manifestation in inflammatory bowel disease (IBD), regarded as an independent risk factor for VTE according to reports from Western countries. However, the incidence and risk factors of VTE in Asian IBD patients are not fully understood. We aimed to reveal the incidence and risk factors of VTE in Japanese IBD inpatients.MethodsThe incidence of VTE in inpatients with IBD (n=340), gastrointestinal cancers (n=557), and other gastrointestinal diseases (n=569) treated at our hospital from 2009 to 2013 was retrospectively investigated. The characteristics and laboratory data of IBD inpatients with and without VTE were compared in univariate and multivariate analyses. Clinical courses of VTE in IBD were surveyed.ResultsVTE was detected in 7.1% of IBD inpatients, significantly higher than in gastrointestinal cancer inpatients (2.5%) and inpatients with other gastrointestinal diseases (0.88%). The incidence of VTE in ulcerative colitis (UC) patients (16.7%) was much higher than that in those with Crohn's disease (3.6%). In the univariate analysis, the risk factors were an older age, central venous catheter, prednisolone, surgery, low serum albumin, high serum C-reactive protein and D-dimer. According to a multivariate analysis, >50 years of age and surgery were the only risk factors. The in-hospital mortality rate of IBD inpatients with VTE was 4.2%.ConclusionsThe incidence of VTE with IBD, especially UC, was found to be high compared with other digestive disease, which was almost equivalent to that of Western countries. The efficacy of prophylaxis needs to be investigated in Asian IBD patients.
- Published
- 2018
- Full Text
- View/download PDF
16. Takayasu’s arteritis associated with eosinophilic gastroenteritis, possibly via the overactivation of Th17
- Author
-
Mikihiro Fujiya, Shin Kashima, Yuya Sugiyama, Takuya Iwama, Masami Ijiri, Kazuyuki Tanaka, Keitaro Takahashi, Katuyoshi Ando, Yoshiki Nomura, Nobuhiro Ueno, Takuma Goto, Kentaro Moriichi, Yusuke Mizukami, Toshikatsu Okumura, Junpei Sasajima, Daisuke Fujishiro, Kensaku Okamoto, and Yuichi Makino
- Subjects
Takayasu’s arteritis ,Eosinophilic gastroenteritis ,The overactivation of TH17 ,Diseases of the digestive system. Gastroenterology ,RC799-869 - Abstract
Abstract Background Takayasu’s arteritis (TA) is a large-vessel vasculitis pathologically characterized by granulomatous necrotizing vasculitis with giant cells. Although the cause of TA is still unclear, genetic factors as well as immunological abnormalities, particularly the overactivation of Th1 and Th-17, are considered to play important roles in the pathogenesis of this disease. Eosinophilic gastroenteritis (EGE) is a type of refractory inflammation in which numerous eosinophils infiltrate the inflammatory area. It is known that the overactivation of Th2 is associated with the pathogenesis of EGE, although the cause of EGE is still unclear. The immunological abnormalities in TA are therefore thought to be different from those in EGE. To date, no cases of complication of TA and EGE have been reported. Case presentations An 18 year-old female was diagnosed with EGE and treated with prednisolone. At 6 months after completion of the treatment, the patient experienced chest pain, and was diagnosed with TA. TH1 and TH17 immunity are thought to be involved with TA, while TH2 are considered to be involved with EGE. In this case, the expression of IL-17 mRNA in the colon mucosa greatly decreased after prednisolone treatment for EGE. Conclusions This is the first report of TA complicated with EGE, and the overactivation of TH17 is considered to be associated with the pathogenesis of these two diseases.
- Published
- 2018
- Full Text
- View/download PDF
17. Autofluorescence Imaging Reflects the Nuclear Enlargement of Tumor Cells as well as the Cell Proliferation Ability and Aberrant Status of the p53, Ki-67, and p16 Genes in Colon Neoplasms
- Author
-
Kentaro Moriichi, Mikihiro Fujiya, Yu Kobayashi, Yuki Murakami, Takuya Iwama, Takehito Kunogi, Takahiro Sasaki, Masami Ijiri, Keitaro Takahashi, Kazuyuki Tanaka, Aki Sakatani, Katsuyoshi Ando, Yoshiki Nomura, Nobuhiro Ueno, Shin Kashima, Katsuya Ikuta, Hiroki Tanabe, Yusuke Mizukami, Yusuke Saitoh, and Toshikatsu Okumura
- Subjects
autofluorescence imaging ,colon neoplasm ,N/C ratio ,methylation ,tumor cell proliferation ,Organic chemistry ,QD241-441 - Abstract
Background: Autofluorescence imaging (AFI) is useful for diagnosing colon neoplasms, but what affects the AFI intensity remains unclear. This study investigated the association between AFI and the histological characteristics, aberrant methylation status, and aberrant expression in colon neoplasms. Methods: Fifty-three patients with colorectal neoplasms who underwent AFI were enrolled. The AFI intensity (F index) was compared with the pathological findings and gene alterations. The F index was calculated using an image analysis software program. The pathological findings were assessed by the tumor crypt density, cell densities, and N/C ratio. The aberrant methylation of p16, E-cadherin, Apc, Runx3, and hMLH1 genes was determined by a methylation-specific polymerase chain reaction. The aberrant expression of p53 and Ki-67 was evaluated by immunohistochemical staining. Results: An increased N/C ratio, the aberrant expression of p53, Ki-67, and the altered methylation of p16 went together with a lower F index. The other pathological findings and the methylation status showed no association with the F index. Conclusions: AFI reflects the nuclear enlargement of tumor cells, the cell proliferation ability, and the altered status of cell proliferation-related genes, indicating that AFI is a useful and practical method for predicting the dysplastic grade of tumor cells and cell proliferation.
- Published
- 2019
- Full Text
- View/download PDF
18. Faraday Tomography of the SS433 Jet Termination Region
- Author
-
Haruka Sakemi, Mami Machida, Takumi Ohmura, Shinsuke Ideguchi, Yoshimitsu Miyashita, Keitaro Takahashi, Takuya Akahori, Hiroki Akamatsu, Hiroyuki Nakanishi, Kohei Kurahara, and Jamie Farnes
- Subjects
magnetic fields ,polarization ,jets and outflows ,W50 ,SS433 ,Astronomy ,QB1-991 - Abstract
A jet termination region provides us with useful information about how a jet interacts with the interstellar medium. Identifying the strength and orientation of magnetic fields at the terminal is crucially important to understanding the mechanism of cosmic-ray acceleration. In this article, we report results of our Faraday-tomography analysis of the eastern region of the radio nebula W50, where a jet from the microquasar SS433 seems to terminate. We apply QU-fitting, a method of Faraday-tomography, to data from the Australia Telescope Compact Array (ATCA) at 1.3⁻3.0 GHz. In the analysis, we distinguish multiple polarized sources along the line of sight. We identify Galactic emission candidates at Faraday depths around 0 rad m−2 and 300 rad m−2. The Galactic emission around 0 rad m−2 is possibly located in front of W50. We also find emission from W50 with Faraday depths between φ = −112 to 228 rad m−2.
- Published
- 2018
- Full Text
- View/download PDF
19. Local recurrence after successful endoscopic submucosal dissection for rectal mucinous mucosal adenocarcinoma: A case report
- Author
-
Yuki Murakami, Hiroki Tanabe, Yusuke Ono, Yuya Sugiyama, Yu Kobayashi, Takehito Kunogi, Takahiro Sasaki, Keitaro Takahashi, Katsuyoshi Ando, Nobuhiro Ueno, Shin Kashima, Sayaka Yuzawa, Kentaro Moriichi, Yusuke Mizukami, Mikihiro Fujiya, and Toshikatsu Okumura
- Subjects
Oncology ,Gastroenterology - Published
- 2023
- Full Text
- View/download PDF
20. Gastro-colic Fistula-associated Hypersplenism Causes Pancytopenia in a Patient with Crohn's Disease
- Author
-
Seisuke Saito, Nobuhiro Ueno, Yuki Kamikokura, Yuya Sugiyama, Yu Kobayashi, Yuki Murakami, Takehito Kunogi, Takahiro Sasaki, Keitaro Takahashi, Katsuyoshi Ando, Shin Kashima, Kentaro Moriichi, Hiroki Tanabe, Mishie Tanino, Toshikatsu Okumura, and Mikihiro Fujiya
- Subjects
Internal Medicine ,General Medicine - Published
- 2023
- Full Text
- View/download PDF
21. Nasal breathing is superior to oral breathing when performing and undergoing transnasal endoscopy: a randomized trial
- Author
-
Keitaro Takahashi, Yuki Murakami, Takahiro Sasaki, Nobuhiro Ueno, Shion Tachibana, Junpei Ikeda, Kenichi Ishigaki, Masashi Horiuchi, Moe Yoshida, Kyoko Uehara, Yu Kobayashi, Yuya Sugiyama, Takehito Kunogi, Mizue Muto, Katsuyoshi Ando, Momotaro Muto, Shin Kashima, Kentaro Moriichi, Hiroki Tanabe, Nobuyuki Yanagawa, Kazumichi Harada, Takashi Teramoto, Toshikatsu Okumura, and Mikihiro Fujiya
- Subjects
Gastroenterology - Abstract
Background Transnasal endoscopy presents a technical difficulty when inserting the flexible endoscope. It is unclear whether a particular breathing method is useful for transnasal endoscopy. Therefore, we conducted a prospective randomized controlled trial to compare endoscopic operability and patient tolerance between patients assigned to nasal breathing or oral breathing groups. Methods 198 eligible patients were randomly assigned to undergo transnasal endoscopy with nasal breathing or with oral breathing. Endoscopists and patients answered questionnaires on the endoscopic operability and patient tolerance using a 100-mm visual analog scale ranging from 0 (non-existent) to 100 (most difficult/unbearable). The visibility of the upper-middle pharynx was recorded. Results Patient characteristics did not differ significantly between the groups. Nasal breathing showed a higher rate of good visibility of the upper-middle pharynx than oral breathing (91.9 % vs. 27.6 %; P Conclusions Nasal breathing is superior to oral breathing for those performing and undergoing transnasal endoscopy. Nasal breathing led to good visibility of the upper-middle pharynx, improved endoscopic operability, and better patient tolerance, and was safer owing to decreased pharyngeal bleeding.
- Published
- 2022
- Full Text
- View/download PDF
22. Elucidation of Liquid Structures and Transport Properties of Highly Concentrated LiN(SO2F)2/Ethylene Carbonate Electrolytes
- Author
-
Reita Furui, Kikuko Hayamizu, Keitaro Takahashi, Seiji Tsuzuki, Hibiki Miyauchi, Kohei Inaba, Yui Kawana, Yasuhiro Umebayashi, and Shiro Seki
- Subjects
General Energy ,Physical and Theoretical Chemistry ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials - Published
- 2023
- Full Text
- View/download PDF
23. Li+ transport properties of sulfolane-based gel polymer electrolyte and effective suppression of lithium polysulfide dissolution in lithium–sulfur batteries
- Author
-
Hibiki Miyauchi, Kohei Inaba, Keitaro Takahashi, Nana Arai, Yasuhiro Umebayashi, and Shiro Seki
- Subjects
Fuel Technology ,Renewable Energy, Sustainability and the Environment ,Energy Engineering and Power Technology - Abstract
New-type sulfolane gel electrolytes exhibited high battery performance owing to chemical and physical control of Li2Sn dissolution and diffusion properties.
- Published
- 2022
- Full Text
- View/download PDF
24. Concomitant pharmacologic medications influence the clinical outcomes of granulocyte and monocyte adsorptive apheresis in patients with ulcerative colitis: A multicenter retrospective cohort study
- Author
-
Nobuhiro Ueno, Yuya Sugiyama, Yu Kobayashi, Yuki Murakami, Takuya Iwama, Takahiro Sasaki, Takehito Kunogi, Aki Sakatani, Keitaro Takahashi, Kazuyuki Tanaka, Shinya Serikawa, Katsuyoshi Ando, Shin Kashima, Momotaro Muto, Yuhei Inaba, Kentaro Moriichi, Hiroki Tanabe, Toshikatsu Okumura, and Mikihiro Fujiya
- Subjects
Hematology ,General Medicine - Abstract
Background: Granulocyte and monocyte adsorptive apheresis (GMA) with Adacolumn has been widely used as a remission induction therapy for patients with active ulcerative colitis (UC). However, an appropriate GMA treatment strategy related to concomitant medication in patients with active UC has not been established. Herein, we investigated the influence of concomitant medications in the remission induction of GMA in patients with active UC.Methods: This multicenter retrospective cohort study included patients with UC who underwent GMA in five independent institutions in Japan from January 2011 to July 2021. Clinical factors associated with clinical remission (CR) were analyzed statistically.Result: A total of 133 patients with active UC who underwent GMA were included. Seventy-four patients achieved a CR after GMA. The overall CR rate was 55.6%. The multivariable analysis revealed that concomitant medication with 5-aminosalicylic acid, Mayo endoscopic subscore (MES), and concomitant medication with immunosuppressors (IMs) remained as predictors of CR after GMA (p = 0.027, odds ratio [OR] 0.157; p = 0.017, OR 2.983; and p = 0.008, OR 3.361, respectively). In the subgroup analysis in patients with MES 2, concomitant medication with IMs was demonstrated as a significant negative factor of CR after GMA (p = 0.042, OR 2.823). Seventy-four patients who achieved CR after GMA were followed up for 52 weeks. CR was sustained in 24 of 74 patients (32%), and the median remission time was 30 weeks. In the multivariable analysis, the maintenance therapy with IMs was demonstrated as a significant positive factor of sustained CR up to 52 weeks (p = 0.038, OR 2.214). The rate of sustained CR in patients with 5-ASA and IMs was not different when compared with that in patients with 5-ASA only (p = 0.248). On the other hands, the rate of sustained CR in patients with biologics and IMs was significantly higher than that in patients with biologics only (p = 0.002).Conclusion: GMA was more effective for patients with active UC that relapsed under treatment without IM. Furthermore, the addition of IMs should be considered in patients on maintenance therapy with biologics after GMA.
- Published
- 2023
- Full Text
- View/download PDF
25. Recorderology - development of a web based instrumentation tool concerning recorder instruments.
- Author
-
Ulrike Mayer-Spohn and Keitaro Takahashi
- Published
- 2016
26. Constraining the 21 cm brightness temperature of the IGM at z = 6.6 around LAEs with the murchison widefield array
- Author
-
Matthew Kolopanis, Adam P. Beardsley, Christopher H. Jordan, Nichole Barry, Q. Zheng, B. McKinley, Randall B. Wayth, E. Howard, Daniel A. Mitchell, Judd D. Bowman, J. S. B. Wyithe, Pratika Dayal, Cathryn M. Trott, Keisuke Hasegawa, Anne Hutter, Miguel F. Morales, Daniel C. Jacobs, Rachel L. Webster, Bradley Greig, Bryna J. Hazelton, A. Chokshi, S. Murray, M. Rahimi, J. L. B. Line, M. Wilensky, S. Yoshiura, Steven Tingay, Christene Lynch, B. Pindor, Keitaro Takahashi, Jonathan C. Pober, R. Byrne, and Astronomy
- Subjects
Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,FOS: Physical sciences ,Murchison Widefield Array ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,0103 physical sciences ,Galaxy formation and evolution ,instrumentation: interferometers ,Instrumentation and Methods for Astrophysics (astro-ph.IM) ,010303 astronomy & astrophysics ,Reionization ,Astrophysics::Galaxy Astrophysics ,Line (formation) ,Physics ,methods: statistical ,010308 nuclear & particles physics ,Astrophysics::Instrumentation and Methods for Astrophysics ,Spectral density ,Astronomy and Astrophysics ,Redshift ,Galaxy ,Space and Planetary Science ,Brightness temperature ,Astrophysics - Instrumentation and Methods for Astrophysics ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
The locations of Ly-$\alpha$ emitting galaxies (LAEs) at the end of the Epoch of Reionisation (EoR) are expected to correlate with regions of ionised hydrogen, traced by the redshifted 21~cm hyperfine line. Mapping the neutral hydrogen around regions with detected and localised LAEs offers an avenue to constrain the brightness temperature of the Universe within the EoR by providing an expectation for the spatial distribution of the gas, thereby providing prior information unavailable to power spectrum measurements. We use a test set of 12 hours of observations from the Murchison Widefield Array (MWA) in extended array configuration, to constrain the neutral hydrogen signature of 58 LAEs, detected with the Subaru Hypersuprime Cam in the \textit{Silverrush} survey, centred on $z$=6.58. We assume that detectable emitters reside in the centre of ionised HII bubbles during the end of reionization, and predict the redshifted neutral hydrogen signal corresponding to the remaining neutral regions using a set of different ionised bubble radii. A prewhitening matched filter detector is introduced to assess detectability. We demonstrate the ability to detect, or place limits upon, the amplitude of brightness temperature fluctuations, and the characteristic HII bubble size. With our limited data, we constrain the brightness temperature of neutral hydrogen to $\Delta{\rm T}_B, Comment: 9 pages, 6 figures, accepted for publication in MNRAS
- Published
- 2021
- Full Text
- View/download PDF
27. Conveying Emotion with Moving Images: Relationship between Movement and Emotion.
- Author
-
Rumi Hiraga and Keitaro Takahashi
- Published
- 2011
- Full Text
- View/download PDF
28. On the Potential of Faraday Tomography to Identify Shock Structures in Supernova Remnants
- Author
-
Shinsuke Ideguchi, Tsuyoshi Inoue, Takuya Akahori, and Keitaro Takahashi
- Subjects
High Energy Astrophysical Phenomena (astro-ph.HE) ,Space and Planetary Science ,Astrophysics::High Energy Astrophysical Phenomena ,Astronomy ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics - High Energy Astrophysical Phenomena ,Astrophysics::Galaxy Astrophysics - Abstract
Knowledge about the magnetic fields in supernova remnants (SNRs) is of paramount importance for constraining Galactic cosmic ray acceleration models. It could also indirectly provide information on the interstellar magnetic fields. In this paper, we predict the Faraday dispersion functions (FDFs) of SNRs for the first time. For this study, we use the results of three dimensional (3D) ideal magnetohydrodynamic (MHD) simulations of SNRs expanding into a weak, regular magnetic field. We present the intrinsic FDFs of the shocked region of SNRs for different viewing angles. We find that the FDFs are generally Faraday complex, which implies that conventional rotation measure study is not sufficient to obtain the information on the magnetic fields in the shocked region and Faraday tomography is necessary. We also show that the FDF allows to derive the physical-depth distribution of polarization intensity when the line of sight is parallel to the initial magnetic field orientation. Furthermore, we demonstrate that the location of contact discontinuity can be identified from the radial profile of the width of the FDF with the accuracy of 0.1–0.2 pc.
- Published
- 2022
29. The Indian Pulsar Timing Array: First data release
- Author
-
Pratik Tarafdar, K Nobleson, Prerna Rana, Jaikhomba Singha, M. A. Krishnakumar, Bhal Chandra Joshi, Avinash Kumar Paladi, Neel Kolhe, Neelam Dhanda Batra, Nikita Agarwal, Adarsh Bathula, Subhajit Dandapat, Shantanu Desai, Lankeswar Dey, Shinnosuke Hisano, Prathamesh Ingale, Ryo Kato, Divyansh Kharbanda, Tomonosuke Kikunaga, Piyush Marmat, B. Arul Pandian, T. Prabu, Aman Srivastava, Mayuresh Surnis, Sai Chaitanya Susarla, Abhimanyu Susobhanan, Keitaro Takahashi, P. Arumugam, Manjari Bagchi, Sarmistha Banik, Kishalay De, Raghav Girgaonkar, A. Gopakumar, Yashwant Gupta, Yogesh Maan, P. K. Manoharan, Arun Naidu, and Dhruv Pathak
- Subjects
High Energy Astrophysical Phenomena (astro-ph.HE) ,Space and Planetary Science ,Astrophysics::High Energy Astrophysical Phenomena ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics - Instrumentation and Methods for Astrophysics ,Astrophysics - High Energy Astrophysical Phenomena ,Instrumentation and Methods for Astrophysics (astro-ph.IM) - Abstract
We present the pulse arrival times and high-precision dispersion measure estimates for 14 millisecond pulsars observed simultaneously in the 300-500 MHz and 1260-1460 MHz frequency bands using the upgraded Giant Metrewave Radio Telescope (uGMRT). The data spans over a baseline of 3.5 years (2018-2021), and is the first official data release made available by the Indian Pulsar Timing Array collaboration. This data release presents a unique opportunity for investigating the interstellar medium effects at low radio frequencies and their impact on the timing precision of pulsar timing array experiments. In addition to the dispersion measure time series and pulse arrival times obtained using both narrowband and wideband timing techniques, we also present the dispersion measure structure function analysis for selected pulsars. Our ongoing investigations regarding the frequency dependence of dispersion measures have been discussed. Based on the preliminary analysis for five millisecond pulsars, we do not find any conclusive evidence of chromaticity in dispersion measures. Data from regular simultaneous two-frequency observations are presented for the first time in this work. This distinctive feature leads us to the highest precision dispersion measure estimates obtained so far for a subset of our sample. Simultaneous multi-band uGMRT observations in Band 3 and Band 5 are crucial for high-precision dispersion measure estimation and for the prospect of expanding the overall frequency coverage upon the combination of data from the various Pulsar Timing Array consortia in the near future. Parts of the data presented in this work are expected to be incorporated into the upcoming third data release of the International Pulsar Timing Array., 23 pages, 21 figures, 3 tables. Published in PASA
- Published
- 2022
30. The Optimal Dose of Tacrolimus in Combination Therapy with an Anti-TNFα Antibody in a Mouse Colitis Model
- Author
-
Nobuhiro Ueno, Hiroki Tanabe, Toshikatsu Okumura, Shin Kashima, Yuki Murakami, Mikihiro Fujiya, Kentaro Moriichi, Yuya Sugiyama, Takehito Kunogi, Hiroaki Konishi, Takahiro Sasaki, Keitaro Takahashi, Katsuyoshi Ando, Shotaro Isozaki, and Yu Kobayashi
- Subjects
Male ,0301 basic medicine ,Combination therapy ,Colon ,Pharmaceutical Science ,chemical and pharmacologic phenomena ,Pharmacology ,Tacrolimus ,Proinflammatory cytokine ,03 medical and health sciences ,0302 clinical medicine ,Animals ,Medicine ,Colitis ,Mice, Inbred BALB C ,biology ,business.industry ,Dextran Sulfate ,Antibodies, Monoclonal ,General Medicine ,medicine.disease ,Ulcerative colitis ,Disease Models, Animal ,stomatognathic diseases ,030104 developmental biology ,030220 oncology & carcinogenesis ,biology.protein ,Cytokines ,Immunohistochemistry ,Drug Therapy, Combination ,Tumor necrosis factor alpha ,Antibody ,business ,Immunosuppressive Agents - Abstract
An attempt to use combination therapy with anti-tumor necrosis factor α (TNFα) antibodies and tacrolimus (TAC) has been tried to induce remission in ulcerative colitis (UC). However, the optimal dose of TAC in combination therapy with anti-TNFα antibodies (TAC + anti-TNFα therapy) remains unclear. We examined the efficacy of various doses of TAC + anti-TNFα therapy in a mouse colitis model. Dextran sulfate sodium induced colitis model mice were divided into an anti-TNFα antibody monotherapy group and the groups that received various doses of TAC + anti-TNFα therapy. The nuclear factor expression of activated T-cells, cytoplasmic 1 (NFATc1) in the nuclei and the mRNA expression of inflammatory cytokines were assessed by immunohistochemistry and RT-PCR, respectively. The serum anti-TNFα antibody concentration was measured with an enzyme-linked immunosorbent assay. The colon length and histological severity were significantly improved in the groups that received any dose of TAC + anti-TNFα therapy. The nuclear expression of NFATc1 was inversely proportional to the administered doses of TAC. The expression levels of inflammatory cytokines tended to decrease in proportion to the dose of TAC. The serum concentration of anti-TNFα antibodies in the high-dose TAC + anti-TNFα therapy was significantly higher than those in the other groups. Low-dose TAC exerted its immunosuppressive effect on T-cells, and additionally, high-dose TAC maintained the serum anti-TNFα antibody concentration. When administered in combination with anti-TNFα antibodies, the dose of TAC should be adjusted according to the disease severity.
- Published
- 2021
- Full Text
- View/download PDF
31. Long-term Observation of Gastric Adenocarcinoma of Fundic Gland Mucosa Type before and after Helicobacter pylori Eradication: a Case Report
- Author
-
Shin Kashima, Yuki Murakami, Mishie Tanino, Hiroki Tanabe, Takahiro Sasaki, Katsuyoshi Ando, Nobuhiro Ueno, Keitaro Takahashi, Yuki Kamikokura, Mikihiro Fujiya, Yu Kobayashi, Sayaka Yuzawa, Toshikatsu Okumura, Yuya Sugiyama, Kentaro Moriichi, and Takehito Kunogi
- Subjects
Cancer Research ,medicine.medical_specialty ,Case Report ,macromolecular substances ,Malignancy ,Gastroenterology ,Lesion ,03 medical and health sciences ,Gastric adenocarcinoma ,0302 clinical medicine ,Internal medicine ,Gastric adenocarcinoma of fundic gland type ,Medicine ,GA-FG ,Eradication ,medicine.diagnostic_test ,Tumor size ,biology ,Helicobacter pylori ,business.industry ,Fundic Gland ,GA-FGM ,New variant ,biology.organism_classification ,medicine.disease ,digestive system diseases ,Endoscopy ,Oncology ,030220 oncology & carcinogenesis ,030211 gastroenterology & hepatology ,medicine.symptom ,business - Abstract
Gastric adenocarcinoma of the fundic gland mucosa type (GA-FGM) was proposed as a new variant of gastric adenocarcinoma of the fundic gland type (GA-FG). However, at present, the influence of Helicobacter pylori and the speed of progression and degree of malignancy in GA-FGM remain unclear. Herein, we report the first case of intramucosal GA-FGM that was endoscopically observed before and after H. pylori eradication over 15 years. The lesion showed the same tumor size with no submucosal invasion and a low MIB-1 labeling index 15 years after its detection using endoscopy. The endoscopic morphology changed from 0-IIa before H. pylori eradication to 0-IIa+IIc and then 0-I after H. pylori eradication. These findings suggest that the unaltered tumor size reflects low-grade malignancy and slow growth, and that the endoscopic morphology is influenced by H. pylori eradication.
- Published
- 2021
32. Effects of Molecular Structure of Cross-Linked Solid Polymer Electrolytes on Ionic Conduction Behavior
- Author
-
Yui Otake, Koji Hiraoka, Keitaro Takahashi, Shuo Ohashi, Mutsuhiro Matsuyama, Sho Kubota, Yushi Kato, and Shiro Seki
- Subjects
Renewable Energy, Sustainability and the Environment ,Materials Chemistry ,Electrochemistry ,Condensed Matter Physics ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials - Abstract
To improve the safety and energy density of Li batteries, all-solid-state batteries (ASSBs) are desired. Solid polymer electrolytes (SPEs) are expected to be promising candidates, owing to features such as their high flexibility and formability. To achieve high-performance ASSBs, we investigated molecular structure design by fabricating two types of SPEs. First, chemically cross-linked polyethylene oxide/polypropylene oxide (P(EO/PO))-based SPEs were formed with low-molecular-weight PEO as side chains. Second, physically cross-linked SPEs were fabricated with short PEO chains (G2) as soft-units and norbornene (NB) as hard-units with intramolecular phase separation. Evaluation of the physicochemical and electrochemical properties of these SPEs was carried out, and the degree of dissociation of the Li salt was investigated by Raman spectroscopy. The phenomenon of decoupling between the segmental motion of the SPEs and ionic conduction was confirmed by Vogel-Fulcher-Tamman equation analysis. P(NB/G2)-based SPEs also exhibited high thermal stability, which originated from the NB unit, according to TG-DTA and DSC measurements. Furthermore, ionic conductivity increased monotonically with the Li salt concentration, in contrast to conventional PEO-based SPEs. Physically cross-linked SPEs achieved the decoupling of ionic conduction from their segmental motion owing to their differences between the ionic and structural components of the SPEs.
- Published
- 2023
- Full Text
- View/download PDF
33. Cardiac Metastasis Caused Fatal Ventricular Arrhythmia in a Patient with a Rectal Neuroendocrine Tumor
- Author
-
Moe Yoshida, Shin Kashima, Nobuhiro Ueno, Yu Kobayashi, Yuki Murakami, Mikihiro Fujiya, Hiroki Sato, Takehito Kunogi, Katsuyoshi Ando, Keitaro Takahashi, Kentaro Moriichi, Toshikatsu Okumura, Hiroki Tanabe, Takuya Iwama, Yuya Sugiyama, and Takahiro Sasaki
- Subjects
Male ,medicine.medical_specialty ,Metastatic lesions ,medicine.medical_treatment ,Rectum ,Octreotide ,Case Report ,030204 cardiovascular system & hematology ,Pericardial effusion ,Heart Neoplasms ,03 medical and health sciences ,0302 clinical medicine ,Internal Medicine ,Cardiac metastasis ,Humans ,Medicine ,cardiovascular diseases ,ventricular arrhythmia ,Chemotherapy ,Rectal Neoplasms ,business.industry ,Ventricular wall ,Arrhythmias, Cardiac ,General Medicine ,Middle Aged ,medicine.disease ,Pancreatic Neoplasms ,Neuroendocrine Tumors ,medicine.anatomical_structure ,cardiovascular system ,030211 gastroenterology & hepatology ,cardiac metastasis ,Radiology ,Ultrasonography ,business ,neuroendocrine tumor ,medicine.drug - Abstract
A 60-year-old man had received octreotide for a metastatic neuroendocrine tumor (NET) in the rectum. Computed tomography and ultrasonography revealed a cardiac tumor, diffuse thickness of the ventricular wall and pericardial effusion, which was diagnosed as cardiac metastasis. The metastatic lesions continued to grow despite the alteration of chemotherapy, and the patient complained of repeated syncope and was admitted to our hospital at 11 months after the diagnosis of cardiac metastasis. An electrocardiogram during syncope showed sustained ventricular tachycardia, which was considered to be caused by the cardiac metastasis. We herein report a case of NET with cardiac metastasis which caused lethal arrhythmia along with a review of the pertinent literature.
- Published
- 2021
- Full Text
- View/download PDF
34. Gastro-colic Fistula-associated Hypersplenism Causes Pancytopenia in a Patient with Crohn's Disease: A Case Report
- Author
-
Seisuke, Saito, Nobuhiro, Ueno, Yuki, Kamikokura, Yuya, Sugiyama, Yu, Kobayashi, Yuki, Murakami, Takehito, Kunogi, Takahiro, Sasaki, Keitaro, Takahashi, Katsuyoshi, Ando, Shin, Kashima, Kentaro, Moriichi, Hiroki, Tanabe, Mishie, Tanino, Toshikatsu, Okumura, and Mikihiro, Fujiya
- Abstract
A 24-year-old woman was admitted to our hospital due to abdominal pain and a high fever. She was diagnosed with ileocolonic Crohn's disease (CD), complicated with a gastro-colic fistula and splenomegaly. After initial treatment with an infliximab-biosimilar, all blood cell line counts markedly decreased. Three-dimensional reconstructed computed tomography revealed splenic vein narrowing. Thus, her pancytopenia was deemed to have likely been caused by hypersplenism. Surgery was performed, and clinical remission was maintained without pancytopenia. This is the first report of a CD patient with pancytopenia caused by hypersplenism that was triggered by gastro-colic fistula-associated splenic vein obstruction.
- Published
- 2022
35. The efficacy of the submucosal injection of lidocaine during endoscopic submucosal dissection for colorectal neoplasms: a multicenter randomized controlled study
- Author
-
Shin Kashima, Yuki Murakami, Keitaro Takahashi, Hiroki Tanabe, Toshikatsu Okumura, Katsuyoshi Ando, Takahiro Sasaki, Yusuke Saito, Takuya Iwama, Nobuhiro Ueno, Masami Ijiri, Mikihiro Fujiya, Kazuyuki Tanaka, and Kentaro Moriichi
- Subjects
medicine.medical_specialty ,Endoscopic Mucosal Resection ,Lidocaine ,Article ,law.invention ,03 medical and health sciences ,0302 clinical medicine ,Randomized controlled trial ,law ,Internal medicine ,Clinical endpoint ,Humans ,Medicine ,Prospective Studies ,Adverse effect ,Prospective cohort study ,Peristalsis ,business.industry ,Dissection ,Hepatology ,Treatment Outcome ,030220 oncology & carcinogenesis ,Anesthesia ,030211 gastroenterology & hepatology ,Surgery ,Colorectal Neoplasms ,business ,Abdominal surgery ,medicine.drug - Abstract
Background Endoscopic submucosal dissection (ESD) is currently a common procedure although it requires a long procedural time. We conducted a prospective study to determine the efficacy and safety of lidocaine injection for shortening the procedural time and relieving bowel peristalsis during ESD. Methods A multicenter randomized controlled study was conducted in three hospitals. Ninety-one patients who underwent colorectal ESD were enrolled. Patients were randomly divided into two groups using the envelope method: the lidocaine group and saline group. The primary endpoint was the procedural time, and the secondary endpoints were the procedural time in each part of the colon and the grade of bowel peristalsis and the incidence and amounts of antispasmodic drugs use and adverse events. Results The patients’ demographics were not markedly different between the two groups. The mean procedural time in the lidocaine group was not markedly different from that in the saline group. In contrast, at the proximal site, the procedural time in the lidocaine group (57 min) was significantly shorter in the saline group (80 min). The grade of bowel peristalsis in the lidocaine group (0.67) was significantly lower than in the saline group (1.17). Antispasmodic drug use was significantly rarer in the lidocaine group than in the saline group. The incidence of adverse events was not markedly different between the two groups. Conclusions Local lidocaine injection is a feasible option for preventing bowel peristalsis, particularly in the proximal colon, leading to a reduced procedural time for ESD and decreased antispasmodic drug use. University Hospital Medical Information Network Center (UMIN number: 000022843).
- Published
- 2020
- Full Text
- View/download PDF
36. Fluoride Ion Conductive Polymer Electrolytes for All-solid-state Fluoride Shuttle Batteries
- Author
-
Atsuya Yokoo, Shiro Seki, Yukari Kaneko, Takeshi Abe, and Keitaro Takahashi
- Subjects
Conductive polymer ,Technology ,Materials science ,transference number ,solid polymer electrolyte ,Physical and theoretical chemistry ,QD450-801 ,fluoride shuttle battery ,all-solid-state battery ,Electrolyte ,Ion ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,All solid state ,Electrochemistry ,Fluoride - Abstract
To control the fluoride dissociation and conduction of polyether-based solid polymer electrolytes, an electrolyte system composed of a host polymer, metal salt, and anion acceptor was proposed. Appropriate choices of metal salt with low lattice enthalpy and anion acceptor concentration were important to obtain polymer electrolytes with high fluoride conductivity. The results of thermal and electrochemical measurements revealed that the optimal electrolyte system displayed a relatively high fluoride conductivity of ca. 1 × 10−6 S cm−1 at 303 K and fluoride transference number of over 0.8 (80%).
- Published
- 2020
37. Detectability of 21-cm signal during the epoch of reionization with 21-cm-Lyman-α emitter cross-correlation – III. Model dependence
- Author
-
Akio K. Inoue, Keitaro Takahashi, Kenji Hasegawa, and Kenji Kubota
- Subjects
Physics ,Cross-correlation ,Astronomy and Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,Galaxy ,Dark matter halo ,Amplitude ,Square kilometre array ,Space and Planetary Science ,Dark Ages ,α emitter ,Reionization ,Astrophysics::Galaxy Astrophysics ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
Detecting $\rm H_I$ 21cm line in the intergalactic medium (IGM) during the Epoch of Reionization (EoR) suffers from foreground contamination such as Galactic synchrotron and extragalactic radio sources. Cross-correlation between the 21cm line and Lyman-$\alpha$ emitter (LAE) galaxies is a powerful tool to identify the 21cm signal since the 21cm line emission has correlation with LAEs while the LAEs are statistically independent of the foregrounds. So far, the detectability of 21cm-LAE cross-power spectrum has been investigated with simple LAE models where the observed Ly$\alpha$ luminosity is proportional to the dark matter halo mass. However, the previous models were inconsistent with the latest observational data of LAEs obtained with Subaru/Hyper Suprime-Cam (HSC). Here, we revisit the detectability of 21cm-LAE cross-power spectrum adopting a state-of-the-art LAE model consistent with all Subaru/HSC observations such as the Ly$\alpha$ luminosity function, LAE angular auto-correlation, and the LAE fractions in the continuum selected galaxies. We find that resultant cross-power spectrum with the updated LAE model is reduced at small scales ($k\sim 1\ \rm Mpc^{-1}$) compared to the simple models, while the amplitudes at large scales ($k \lesssim 0.2 \ \rm Mpc^{-1}$) are not affected so much. We conclude that the large-scale signal would be detectable with Square Kilometre Array (SKA) and HSC LAE cross-correlation but detecting the small scale signal would require an extended HSC LAE survey with an area of $\sim 75\ \rm deg^2$ or 3000 hrs observation time of 21cm line with SKA., Comment: 11 pages, 10 figures, accepted to Monthly Notices of the Royal Astronomical Society
- Published
- 2020
- Full Text
- View/download PDF
38. Artificial neural networks for selection of pulsar candidates from radio continuum surveys
- Author
-
Shi Dai, Shinsuke Ideguchi, S. Yoshiura, Keitaro Takahashi, Hiroki Kumamoto, and Naoyuki Yonemaru
- Subjects
Physics ,Artificial neural network ,010308 nuclear & particles physics ,Continuum (topology) ,Astronomy ,Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics::Instrumentation and Methods for Astrophysics ,Astronomy and Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,Methods statistical ,Pulsar ,Space and Planetary Science ,0103 physical sciences ,Statistical physics ,010303 astronomy & astrophysics ,Astrophysics::Galaxy Astrophysics ,Selection (genetic algorithm) - Abstract
It is very computationally expensive to search for pulsars using time-domain observations, and the volume of data will be enormous with next-generation telescopes such as the Square Kilometre Array. We use artificial neural networks (ANNs), a machine learning method, for the efficient selection of pulsar candidates from radio continuum surveys; this is much cheaper than using time-domain observations. With observed quantities such as radio fluxes, sky position and compactness as inputs, our ANNs output the ‘score’ that indicates the degree of likeliness that an object is a pulsar. We demonstrate ANNs based on existing survey data by the Tata Institute for Fundamental Research (TIFR) Giant Metrewave Radio Telescope (GMRT) Sky Survey (TGSS) and the National Radio Astronomy Observatory (NRAO) Very Large Array (VLA) Sky Survey (NVSS) and we test their performance. The precision, which is the ratio of the number of pulsars classified correctly as pulsars to the number of any objects classified as pulsars, is about $96 {{\ \rm per\ cent}}$. Finally, we apply the trained ANNs to unidentified radio sources and our fiducial ANN with five inputs (the galactic longitude and latitude, the TGSS and NVSS fluxes and compactness) generates 2436 pulsar candidates from 456 866 unidentified radio sources. We need to confirm whether these candidates are truly pulsars by using time-domain observations. More information, such as polarization, will narrow the number of candidates down further.
- Published
- 2020
- Full Text
- View/download PDF
39. Faraday Dispersion Function of Disk Galaxies with Axisymmetric Global Magnetic Fields. I
- Author
-
Haruya Eguchi, Keitaro Takahashi, Shinsuke Ideguchi, Masaki Suzuki, and Yoshimitsu Miyashita
- Subjects
Physics ,010504 meteorology & atmospheric sciences ,Turbulence ,Astronomy ,Rotational symmetry ,Astronomy and Astrophysics ,01 natural sciences ,Galaxy ,law.invention ,Magnetic field ,Computational physics ,Space and Planetary Science ,law ,0103 physical sciences ,Pitch angle ,Dispersion (water waves) ,Faraday cage ,010303 astronomy & astrophysics ,Beam (structure) ,0105 earth and related environmental sciences - Abstract
Faraday tomography is a novel method to probe 3-dimensional structure of magnetic fields of polarized radio sources. In this paper, we investigate Faraday dispersion function (FDF) of disk galaxies extending a simple analytic model of galactic magnetic fields developed in Ideguchi et al. (2017). The model consists of axisymmetric coherent fields and turbulent fields and we consider the effects of inclination, relative amplitude of coherent and turbulent magnetic fields and pitch angle of coherent fields. Our simple model makes it easy to obtain physical interpretation of FDFs and helps understanding observational results. We find FDFs have two peaks when galaxies are observed with non zero inclination. The gap and relative height of two peaks are dependent on the inclination angle and pitch angle but are not affected by relative amplitude of coherent and turbulent magnetic fields so much. These findings give us an important caution that two peaks in observed FDFs do not necessarily imply the presence of two separate radio sources within a beam.
- Published
- 2020
- Full Text
- View/download PDF
40. Nanohertz Gravitational Wave Astronomy during the SKA Era: An InPTA perspective
- Author
-
Bhal Chandra Joshi, Achamveedu Gopakumar, Arul Pandian, Thiagaraj Prabu, Lankeswar Dey, Manjari Bagchi, Shantanu Desai, Pratik Tarafdar, Prerna Rana, Yogesh Maan, Neelam Dhanda BATRA, Raghav Girgaonkar, Nikita Agarwal, Paramasivan Arumugam, Avishek Basu, Adarsh Bathula, Subhajit Dandapat, Yashwant Gupta, Shinnosuke Hisano, Ryo Kato, Divyansh Kharbanda, Tomonosuke Kikunaga, Neel Kolhe, M. A. Krishnakumar, P. K. Manoharan, Piyush Marmat, Arun Naidu, Sarmistha Banik, K. Nobleson, Avinash Kumar Paladi, Dhruv Pathak, Jaikhomba Singha, Aman Srivastava, Mayuresh Surnis, Sai Chaitanya Susarla, Abhimanyu Susobhanan, and Keitaro Takahashi
- Subjects
High Energy Astrophysical Phenomena (astro-ph.HE) ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics::Instrumentation and Methods for Astrophysics ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics - High Energy Astrophysical Phenomena ,Astrophysics - Instrumentation and Methods for Astrophysics ,Instrumentation and Methods for Astrophysics (astro-ph.IM) ,Solar and Stellar Astrophysics (astro-ph.SR) - Abstract
Decades long monitoring of millisecond pulsars, which exhibit highly stable rotational periods, in pulsar timing array experiments is on the threshold of discovering nanohertz stochastic gravitational wave background. This paper describes the Indian Pulsar timing array (InPTA) experiment, which employs the upgraded Giant Metrewave Radio Telescope (uGMRT) for timing an ensemble of millisecond pulsars for this purpose. We highlight InPTA's observation strategies and analysis methods, which are relevant for a future PTA experiment with the more sensitive Square Kilometer Array (SKA) telescope. We show that the unique multi-sub-array multi-band wide-bandwidth frequency coverage of the InPTA provides Dispersion Measure estimates with unprecedented precision for PTA pulsars, e.g., ~ 2 x 10{-5} pc-cm{-3} for PSR J1909-3744. Configuring the SKA-low and SKA-mid as two and four sub-arrays respectively, it is shown that comparable precision is achievable, using observation strategies similar to those pursued by the InPTA, for a larger sample of 62 pulsars requiring about 26 and 7 hours per epoch for the SKA-mid and the SKA-low telescopes respectively. We also review the ongoing efforts to develop PTA-relevant general relativistic constructs that will be required to search for nanohertz gravitational waves from isolated super-massive black hole binary systems like blazar OJ 287. These efforts should be relevant to pursue persistent multi-messenger gravitational wave astronomy during the forthcoming era of the SKA telescope, the Thirty Meter Telescope, and the next-generation Event Horizon Telescope., Comment: Accepted for publication in Journal of Astronomy and Astrophysics for Special Issue on Indian Participation in the SKA (Editors : Abhirup Datta, Nirupam Roy, Preeti Kharb and Tirthankar Roy Choudhury)
- Published
- 2022
- Full Text
- View/download PDF
41. Low-frequency wideband timing of InPTA pulsars observed with the uGMRT
- Author
-
K Nobleson, Nikita Agarwal, Raghav Girgaonkar, Arul Pandian, Bhal Chandra Joshi, M A Krishnakumar, Abhimanyu Susobhanan, Shantanu Desai, T Prabu, Adarsh Bathula, Timothy T Pennucci, Sarmistha Banik, Manjari Bagchi, Neelam Dhanda Batra, Arpita Choudhary, Subhajit Dandapat, Lankeswar Dey, Yashwant Gupta, Shinnosuke Hisano, Ryo Kato, Divyansh Kharbanda, Tomonosuke Kikunaga, Neel Kolhe, Yogesh Maan, Piyush Marmat, P Arumugam, P K Manoharan, Dhruv Pathak, Jaikhomba Singha, Mayuresh P Surnis, Sai Chaitanya Susarla, and Keitaro Takahashi
- Subjects
High Energy Astrophysical Phenomena (astro-ph.HE) ,Space and Planetary Science ,Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics::Instrumentation and Methods for Astrophysics ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics - Instrumentation and Methods for Astrophysics ,Astrophysics - High Energy Astrophysical Phenomena ,Instrumentation and Methods for Astrophysics (astro-ph.IM) - Abstract
High-precision measurements of the pulsar dispersion measure (DM) are possible using telescopes with low-frequency wideband receivers. We present an initial study of the application of the wideband timing technique, which can simultaneously measure the pulsar times of arrival (ToAs) and DMs, for a set of five pulsars observed with the upgraded Giant Metrewave Radio Telescope (uGMRT) as part of the Indian Pulsar Timing Array (InPTA) campaign. We have used the observations with the 300-500 MHz band of the uGMRT for this purpose. We obtain high precision in DM measurements with precisions of the order 10^{-6}cm^{-3}pc. The ToAs obtained have sub-{\mu}s precision and the root-mean-square of the post-fit ToA residuals are in the sub-{\mu}s range. We find that the uncertainties in the DMs and ToAs obtained with this wideband technique, applied to low-frequency data, are consistent with the results obtained with traditional pulsar timing techniques and comparable to high-frequency results from other PTAs. This work opens up an interesting possibility of using low-frequency wideband observations for precision pulsar timing and gravitational wave detection with similar precision as high-frequency observations used conventionally., Comment: Accepted for publication in MNRAS
- Published
- 2021
42. Wavelets and sparsity for Faraday tomography
- Author
-
Suchetha Cooray, Tsutomu T Takeuchi, Shinsuke Ideguchi, Takuya Akahori, Yoshimitsu Miyashita, and Keitaro Takahashi
- Subjects
High Energy Astrophysical Phenomena (astro-ph.HE) ,Space and Planetary Science ,Astrophysics of Galaxies (astro-ph.GA) ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics - Instrumentation and Methods for Astrophysics ,Astrophysics - High Energy Astrophysical Phenomena ,Instrumentation and Methods for Astrophysics (astro-ph.IM) ,Astrophysics - Astrophysics of Galaxies - Abstract
Faraday tomography through broadband polarimetry can provide crucial information on magnetized astronomical objects, such as quasars, galaxies, or galaxy clusters. However, the limited wavelength coverage of the instruments requires that we solve an ill-posed inverse problem when we want to obtain the Faraday dispersion function (FDF), a tomographic distribution of the magnetoionic media along the line of sight. This paper explores the use of wavelet transforms and the sparsity of the transformed FDFs in the form of wavelet shrinkage (WS) for finding better solutions to the inverse problem. We recently proposed the Constraining and Restoring iterative Algorithm for Faraday Tomography (CRAFT; Cooray et al. 2021), a new flexible algorithm that showed significant improvements over the popular methods such as Rotation Measure Synthesis. In this work, we introduce CRAFT+WS, a new version of CRAFT incorporating the ideas of wavelets and sparsity. CRAFT+WS exhibit significant improvements over the original CRAFT when tested for a complex FDF of realistic Galactic model. Reconstructions of FDFs demonstrate super-resolution in Faraday depth, uncovering previously unseen Faraday complexities in observations. The proposed approach will be necessary for effective cosmic magnetism studies using the Square Kilometre Array and its precursors., 10 Pages, 3 Figures, Submitted to PASJ. Code will be made available upon publication
- Published
- 2021
43. DIPS5 FOR MAX: Digital Image Processing with Sound, version 5.
- Author
-
Takayuki Rai, Shu Matsuda, Yota Morimoto, Keitaro Takahashi, and Takyuto Fukuda
- Published
- 2013
44. Prognostic factors to predict the survival in patients with advanced gastric cancer who receive later-line nivolumab monotherapy-The Asahikawa Gastric Cancer Cohort Study (AGCC)
- Author
-
Takahiro Sasaki, Kyoko Uehara, Shiro Yokohama, Shin Kashima, Hiroki Tanabe, Chisato Ishikawa, Mishie Tanino, Masaki Taruiishi, Yuki Murakami, Naoyuki Yanagida, Kentaro Moriichi, Yasuo Sumi, Hiromitsu Akabane, Mitsuru Goto, Katsuyoshi Ando, Mikihiro Fujiya, Sayaka Yuzawa, Yu Kobayashi, Takehito Kunogi, Yuya Sugiyama, Toshikatsu Okumura, Yohei Kitano, Keisuke Sato, Kazuyuki Tanaka, Nobuhiro Ueno, Hiroki Sato, Keitaro Takahashi, Kimiharu Hasegawa, and Yusuke Mizukami
- Subjects
Oncology ,Adult ,Male ,Cancer Research ,medicine.medical_specialty ,Multivariate analysis ,Neutrophils ,medicine.medical_treatment ,Kaplan-Meier Estimate ,chemotherapy ,nomogram ,Leukocyte Count ,Antineoplastic Agents, Immunological ,Stomach Neoplasms ,Internal medicine ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Lymphocytes ,Prospective Studies ,gastric carcinoma ,RC254-282 ,Research Articles ,Aged ,Proportional Hazards Models ,Aged, 80 and over ,Chemotherapy ,business.industry ,Bone metastasis ,Cancer ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,Clinical Cancer Research ,Nomogram ,Middle Aged ,medicine.disease ,Prognosis ,Nivolumab ,Cohort ,biomarker ,Female ,microsatellite instability ,business ,Cohort study ,Research Article - Abstract
Background Chemotherapy for advanced gastric cancer is recommended in the guidelines; however, later‐line treatment remains controversial. Since immune checkpoint inhibitors have been used for the treatment of various malignancies, trials have been performed for gastric cancer. A phase 3 trial indicated the survival benefit of nivolumab monotherapy for gastric cancer patients treated with prior chemotherapy regimens. Patients and methods A regional cohort study was undertaken to determine the real‐world data of nivolumab treatment for patients with advanced or recurrent gastric cancer. The patients were enrolled for 2 years from October 2017 to October 2019 and were prospectively followed for 1 year to examine the overall survival (OS). The patient characteristics were analyzed in a multivariate analysis and a nomogram to predict the probability of survival was generated. Results In total, 70 patients who received nivolumab as ≥third‐line chemotherapy were included in the Asahikawa Gastric Cancer Cohort. The median OS was 7.5 (95% CI, 4.8–10.2) months and the response rate was 18.6%. Diffuse type classification, bone metastasis, high neutrophil/lymphocyte ratio, and high CRP were associated with poor OS/prognosis in the multivariate analysis. A nomogram was developed based on these clinical parameters and the concordance index was 0.80 (95% CI, 0.68–0.91). The responders were aged and were frequently diagnosed with intestinal type gastric cancer, including patients with a HER2‐positive status (27.3%) or microsatellite instability‐high (27.3%) status. Conclusions The regional cohort study of nivolumab monotherapy for gastric cancer patients revealed prognostic factors and a nomogram was developed that could predict the probability of survival., Development and validation of the nomogram. The nomogram of different risk factors for survival at 7.5 months in gastric cancer patients treated with nivolumab.
- Published
- 2021
45. Carbazochrome sodium sulfonate is not effective for prevention of post-gastric endoscopic submucosal dissection bleeding: A retrospective study
- Author
-
Keitaro Takahashi, Takahiro Sasaki, Nobuhiro Ueno, Kyoko Uehara, Yu Kobayashi, Yuya Sugiyama, Yuki Murakami, Takehito Kunogi, Katsuyoshi Ando, Shin Kashima, Kentaro Moriichi, Hiroki Tanabe, Toshikatsu Okumura, and Mikihiro Fujiya
- Subjects
Adrenochrome ,Endoscopic Mucosal Resection ,Gastric Mucosa ,Heparin ,Risk Factors ,Stomach Neoplasms ,Gastroscopy ,Humans ,Surgery ,Warfarin ,Postoperative Hemorrhage ,Gastrointestinal Hemorrhage ,Retrospective Studies - Abstract
Background Carbazochrome sodium sulfonate (CSS) is conventionally administered to prevent post-endoscopic submucosal dissection (ESD) bleeding in many institutions, but research on its preventive efficacy is lacking. Therefore, we investigated the risk of post-ESD bleeding and the preventive efficacy of CSS administration. Methods We retrospectively reviewed 304 lesions in 259 patients with gastric neoplasms who underwent ESD at Asahikawa Medical University Hospital from 2014 to 2021. In the CSS group, CSS 100 mg/day was intravenously infused with maintenance fluid replacement on postoperative days 0–2. The risk factors of post-ESD bleeding, including CSS administration, were investigated. Results The overall rate of post-ESD bleeding was 4.6% (14/304). The univariate analysis showed that atrial fibrillation (Af), warfarin intake, heparin replacement, and tumor location in the lower third were significant risk factors for increasing the likelihood of postoperative bleeding. In the multivariate analysis, Af (odds ratio [OR] 3.83, 95% CI 1.02–14.30; p p p p = 0.783). Additionally, CSS was not shown to have preventive effects in groups with higher-risk factors, such as Af diagnosis, warfarin use, heparin replacement, and tumor location in the lower third of the stomach. Conclusion CSS administration was not effective for the prevention of the post-ESD bleeding in the overall patient population as well as in higher-risk patients. This suggests that the administration of CSS for post-ESD bleeding prevention may need to be reconsidered.
- Published
- 2021
46. Fecal calprotectin is a useful biomarker for predicting the clinical outcome of granulocyte and monocyte adsorptive apheresis in ulcerative colitis patients: a prospective observation study
- Author
-
Kazuyuki Tanaka, Shin Kashima, Hiroki Tanabe, Yuki Murakami, Nobuhiro Ueno, Yuhei Inaba, Katsuyoshi Ando, Yuya Sugiyama, Yusuke Saitoh, Takahiro Sasaki, Yu Kobayashi, Toshikatsu Okumura, Takuya Iwama, Takehito Kunogi, Masaki Taruishi, Keitaro Takahashi, Kentaro Moriichi, and Mikihiro Fujiya
- Subjects
medicine.medical_specialty ,Colonoscopy ,RC799-869 ,Clinical remission ,Gastroenterology ,Monocytes ,Feces ,Fecal calprotectin ,Internal medicine ,Remission Induction Therapy ,Humans ,Medicine ,Prospective Studies ,Intestinal Mucosa ,Granulocyte/Monocyte Apheresis (GMA) ,medicine.diagnostic_test ,business.industry ,Research ,Monocyte ,Remission Induction ,Biomarker ,General Medicine ,Diseases of the digestive system. Gastroenterology ,Hepatology ,medicine.disease ,Ulcerative colitis ,Treatment Outcome ,Apheresis ,medicine.anatomical_structure ,Blood Component Removal ,Biomarker (medicine) ,Colitis, Ulcerative ,Calprotectin ,Endoscopic remission ,business ,Leukocyte L1 Antigen Complex ,Biomarkers ,Granulocytes - Abstract
Background Granulocyte and monocyte adsorptive apheresis (GMA) is widely used as a remission induction therapy for active ulcerative colitis (UC) patients. However, there are no available biomarkers for predicting the clinical outcome of GMA. We investigated the utility of Fecal calprotectin (FC) as a biomarker for predicting the clinical outcome during GMA therapy in active UC patients. Methods In this multicenter prospective observation study, all patients received 10 sessions of GMA, twice a week, for 5 consecutive weeks. FC was measured at entry, one week, two weeks, and at the end of GMA. Colonoscopy was performed at entry and after GMA. The clinical activity was assessed based on the partial Mayo score when FC was measured. Clinical remission (CR) was defined as a partial Mayo score of ≤ 2 and endoscopic remission (ER) was defined as Mayo endoscopic subscore of either 0 or 1. We analyzed the relationships between the clinical outcome (CR and ER) and the change in FC concentration. Result Twenty-six patients were included in this study. The overall CR and ER rates were 50.0% and 19.2%, respectively. After GMA, the median FC concentration in patients with ER was significantly lower than that in patients without ER (469 mg/kg vs. 3107 mg/kg, p = 0.03). When the cut-off value of FC concentration was set at 1150 mg/kg for assessing ER after GMA, the sensitivity and specificity were 0.8 and 0.81, respectively. The FC concentration had significantly decreased by one week. An ROC analysis demonstrated that the reduction rate of FC (ΔFC) at 1 week was the most accurate predictor of CR at the end of GMA (AUC = 0.852, P = 0.002). When the cut-off value of ΔFC was set at ≤ 40% at 1 week for predicting CR at the end of GMA, the sensitivity and specificity were 76.9% and 84.6%, respectively. Conclusion We evaluated the utility of FC as a biomarker for assessing ER after GMA and predicting CR in the early phase during GMA in patients with active UC. Our findings will benefit patients with active UC by allowing them to avoid unnecessary invasive procedures and will help establish new strategies for GMA.
- Published
- 2021
- Full Text
- View/download PDF
47. Hsp104 contributes to freeze-thaw tolerance by maintaining proteasomal activity in a spore clone isolated from Shirakami kodama yeast
- Author
-
Mizuki Ashizaki, Yukari Shibata, Nobushige Nakazawa, Keitaro Takahashi, and Mami Fukuda
- Subjects
0106 biological sciences ,Thermotolerance ,Proteasome Endopeptidase Complex ,Saccharomyces cerevisiae Proteins ,Saccharomyces cerevisiae ,Clone (cell biology) ,01 natural sciences ,Applied Microbiology and Biotechnology ,Microbiology ,03 medical and health sciences ,010608 biotechnology ,Freezing ,Heat-Shock Proteins ,030304 developmental biology ,Leavening agent ,0303 health sciences ,biology ,Strain (chemistry) ,Chemistry ,Spores, Fungal ,biology.organism_classification ,Fusion protein ,Yeast ,Cell biology ,Proteasome ,Catalase ,biology.protein - Abstract
The supply of oven-fresh bakery products to consumers has been improved by frozen dough technology; however, freeze-thaw stress decreases the activity of yeast cells. To breed better baker's yeasts for frozen dough, it is important to understand the factors affecting freeze-thaw stress tolerance in baker's yeast. We analyzed the stress response in IB1411, a spore clone from Saccharomyces cerevisiae Shirakami kodama yeast, with an exceptionally high tolerance to freeze-thaw stress. Genes encoding trehalose-6-phosphate synthase (TPS1), catalase (CTT1), and disaggregase (HSP104) were highly expressed in IB1411 cells even under conditions of non-stress. The expression of Hsp104 protein was also higher in IB1411 cells even under non-stress conditions. Deletion of HSP104 (hsp104Δ) in IB1411 cells reduced the activity of the ubiquitin-proteasome system (UPS). By monitoring the accumulation of aggregated proteins using the ΔssCPY*-GFP fusion protein under freeze-thaw stress or treatment with proteasomal inhibitor, we found that IB1411 cells resolved aggregated proteins faster than the hsp104Δ strain. Thus, Hsp104 seems to contribute to freeze-thaw tolerance by maintaining UPS activity via the disaggregation of aggregated proteins. Lastly, we found that the IB1411 cells maintained high leavening ability in frozen dough as compared with the parental strain, Shirakami kodama yeast, and thus will be useful for making bread.
- Published
- 2021
48. Gastric submucosa-invasive carcinoma associated with Epstein-Barr virus and endoscopic submucosal dissection: A case report
- Author
-
Takuya Iwama, Takahiro Sasaki, Yoshiki Nomura, Katsuyoshi Ando, Hidehiro Takei, Keitaro Takahashi, Shin Kashima, Yuki Murakami, Nobuhiro Ueno, Hiroki Tanabe, Mikihiro Fujiya, Yu Kobayashi, Kentaro Moriichi, Takehito Kunogi, and Toshikatsu Okumura
- Subjects
Pathology ,medicine.medical_specialty ,Stomach neoplasms ,medicine.disease_cause ,digestive system ,Virus ,03 medical and health sciences ,Epstein-Barr virus associated gastric carcinoma ,0302 clinical medicine ,hemic and lymphatic diseases ,Case report ,Gastric submucosa ,Carcinoma ,medicine ,Gastric carcinoma with lymphoid stroma ,Invasive carcinoma ,business.industry ,digestive, oral, and skin physiology ,Herpesvirus 4 ,Gastroenterology ,Endoscopic submucosal dissection ,medicine.disease ,Epstein–Barr virus ,digestive system diseases ,Epstein-Barr virus-associated gastric carcinoma ,Oncology ,030220 oncology & carcinogenesis ,030211 gastroenterology & hepatology ,business ,Gastric Carcinoma with Lymphoid Stroma ,Human - Abstract
BACKGROUND Epstein-Barr virus (EBV)-associated carcinoma is a gastric cancer subtype with a morphology characterized by gastric carcinoma with lymphoid stroma (GCLS). Clinicopathological studies have indicated a better prognosis for GCLS than for common gastric carcinomas. Some previous cases of early gastric cancer associated with EBV had been diagnosed by endoscopic resection. CASE SUMMARY We present two GCLS cases subjected to endoscopic submucosal dissection (ESD) for a definitive diagnosis. A protruded gastric lesion was identified by routine endoscopic examination, but forceps biopsy showed no atypical cells before ESD. The resected specimen showed a poorly differentiated adenocarcinoma with lymphoid cells involving the mucosa and submucosa. The final diagnosis was submucosa-invasive poorly differentiated gastric adenocarcinoma. Accordingly, additional gastrectomy was recommended to obtain a complete cure. One patient underwent additional distal gastrectomy with lymph node dissection, but the other was refused because of cardiovascular complications. Both patients remained in remission for more than half a year. EBV positivity was determined by EBV-encoded RNA in situ hybridization. We also conducted a literature review of cases of early gastric cancer associated with EBV that had been diagnosed by ESD. CONCLUSION Submucosa-invasive GCLS could be dissected using ESD, and EBV positivity should be subsequently assessed to determine whether or not any additional curative surgery is required. Further prospective investigations on the prevalence of lymph node metastasis in EBV-associated carcinoma should be performed to expand the indications for endoscopic resection.
- Published
- 2019
- Full Text
- View/download PDF
49. Detailed study of detection method for ultralow frequency gravitational waves with pulsar spin-down rate statistics
- Author
-
Hiroki Kumamoto, Keitaro Takahashi, Naoyuki Yonemaru, and Shinnosuke Hisano
- Subjects
High Energy Astrophysical Phenomena (astro-ph.HE) ,Physics ,010308 nuclear & particles physics ,Gravitational wave ,Astrophysics::High Energy Astrophysical Phenomena ,Astrophysics::Instrumentation and Methods for Astrophysics ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,Polarization (waves) ,01 natural sciences ,Galaxy ,Methods statistical ,Amplitude ,Pulsar ,Space and Planetary Science ,0103 physical sciences ,Time derivative ,Astrophysics - High Energy Astrophysical Phenomena ,010303 astronomy & astrophysics - Abstract
A new detection method for gravitational waves (GWs) with ultra-low frequencies ($f_{\rm GW} \lesssim 10^{-10}~{\rm Hz}$), which is much lower than the range of pulsar timing arrays (PTAs), was proposed in Yonemaru et al. (2016). This method utilizes the statistical properties of spin-down rates of milli-second pulsars (MSPs) and the sensitivity was evaluated in Yonemaru et al. (2018). There, some simplifying assumptions, such as neglect of the "pulsar term" and spatially uniform distribution of MSPs, were adopted and the sensitivity on the time derivative of GW amplitude was estimated to be $10^{-19}~{\rm s}^{-1}$ independent of the direction, polarization and frequency of GWs. In this paper, extending the previous analysis, realistic simulations are performed to evaluate the sensitivity more reasonably. We adopt a model of 3-dimensional pulsar distribution in our Galaxy and take the pulsar term into account. As a result, we obtain expected sensitivity as a function of the direction, polarization and frequency of GWs. The dependence on GW frequency is particularly significant and the sensitivity becomes worse by a few orders for $< 10^{-12}~{\rm Hz}$ compared to the previous estimates., 7 pages, 9 figures, submit to MNRAS
- Published
- 2019
- Full Text
- View/download PDF
50. White coat status is a predictive marker for post-esophageal endoscopic submucosal dissection stricture: a retrospective study
- Author
-
Takeshi Saito, Katsuyoshi Ando, Masami Ijiri, Toshikatsu Okumura, Mitsuru Goto, Keitaro Takahashi, Yuya Sugiyama, Kazuyuki Tanaka, Takuya Iwama, Takahiro Sasaki, Mikihiro Fujiya, Yoshiki Nomura, Aki Sakatani, Shin Kashima, Yuki Murakami, Nobuhiro Ueno, and Kentaro Moriichi
- Subjects
Male ,medicine.medical_specialty ,Esophageal Mucosa ,Endoscopic Mucosal Resection ,Constriction, Pathologic ,Gastroenterology ,03 medical and health sciences ,Esophagus ,0302 clinical medicine ,Risk Factors ,Clinical Decision Rules ,Internal medicine ,medicine ,Humans ,In patient ,Endoscopy, Digestive System ,Postoperative Period ,Ulcer ,Esophageal stricture ,Aged ,Retrospective Studies ,Aged, 80 and over ,Predictive marker ,business.industry ,White coat ,Prevention ,Retrospective cohort study ,Endoscopic submucosal dissection ,Odds ratio ,Middle Aged ,medicine.disease ,Cardiothoracic surgery ,Case-Control Studies ,030220 oncology & carcinogenesis ,Esophageal Stenosis ,Original Article ,Female ,Steroids ,030211 gastroenterology & hepatology ,Prediction ,business - Abstract
This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creat iveco mmons .org/licen ses/by/4.0/), BACKGROUND: Steroid therapy is primarily used to prevent esophageal stricture after endoscopic submucosal dissection (ESD). However, esophageal stricture can still occur after preventive therapy, and the effect of preventive steroid therapy cannot be predicted before stricture formation. This study aimed to clarify the risk factors for esophageal stricture after preventive steroid therapy. METHODS: This was a retrospective study conducted at three institutions. From January 2011 to February 2018, 28 large-sized SENs in 26 patients who had a mucosal defect that involved more than three-quarters of the esophageal circumference were enrolled. We classified white coats on artificial ulcers after esophageal ESD into three groups (thin, moderately thick, thick) based on endoscopic images obtained on postoperative day 7. RESULTS: The white coat status on the artificial ulcer after ESD was a significant risk factor for post-ESD stricture (p
- Published
- 2019
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.