426 results on '"Ken Kikuchi"'
Search Results
2. Autistic traits in neurotypical adults are related to impaired perceptual–motor coordination
- Author
-
Ken Kikuchi and Takahiro Higuchi
- Subjects
Anticipatory motor planning ,Autistic traits ,Body-related spatial perception ,Injury ,Perceptual–motor coordination ,Psychology ,BF1-990 - Abstract
Abstract Individuals with autism spectrum disorder (ASD) are more prone to injury due to falls or collisions with objects. This may be caused by impaired perceptual–motor coordination, including inaccurate body-related spatial perception and insufficient anticipatory motor planning due to a detail-focused processing style. To investigate this hypothesis, an action-selection task was developed to create conditions likely to induce collisions with obstacles and to assess perceptual accuracy and predictive attentional properties for the action selection of subsequent movements in a sequence of actions. Sixteen participants completed an autism-spectrum quotient (AQ) survey and the task. Results indicated that AQ correlated significantly with body-related spatial perception, and it was a significant predictor of the number of collisions. For the association between collisions and the eye-tracking data, results of a generalized linear mixed model showed that collisions were more likely to happen when the total fixation time to exit width was short and when the time to first fixation was late. This suggests that participants with higher autistic traits were not able to properly plan subsequent movements. Overall, these findings suggested that impaired perceptual–motor coordination, which could occur due to difficulties in perceiving body-related spatial relationships and anticipatory motor planning, may underlie the high susceptibility to injury observed in individuals with ASD.
- Published
- 2024
- Full Text
- View/download PDF
3. A New Calibration Technique of Electromagnetic Simulators for Accurate Analyses of Microwave Components on Epitaxial Wafers
- Author
-
Ken Kikuchi, Antonio Raffo, Valeria Vadala, Gianni Bosi, Giorgio Vannini, and Hiroshi Yamamoto
- Subjects
Electromagnetic simulations ,GaN HEMTs ,microwave semiconductor devices ,microwave measurements ,on-wafer measurements ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 - Abstract
This article describes an innovative methodology to calibrate EM simulators, oriented to monolithic microwave integrated circuit design, in order to achieve the highest level of accuracy achievable in electromagnetic simulation. In particular, a two-stage measurement technique based on two types of network analyzer calibrations is adopted as a practical and accurate process for on-wafer S-parameter measurements of suitable test structures on semiconductor epitaxial wafers. Thus, a substrate parameter set for the electromagnetic simulator is appropriately identified by an optimization process that combines measurements of dedicated simple test structures and the corresponding models in the circuit simulator. The proposed approach allows one to accurately estimate the substrate characteristics without realizing expensive on-wafer structures that require a large substrate area. We will demonstrate, through several comparisons between measurements and electromagnetic simulations of different passive structures, how higher accuracy can be achieved, describing and quantifying the limitations that arise from commonly adopted calibration procedures for electromagnetic simulators.
- Published
- 2024
- Full Text
- View/download PDF
4. Correction: Furugaito et al. Antimicrobial Susceptibility to 27 Drugs and the Molecular Mechanisms of Macrolide, Tetracycline, and Quinolone Resistance in Gemella sp. Antibiotics 2023, 12, 1538
- Author
-
Michiko Furugaito, Yuko Arai, Yutaka Uzawa, Toshinori Kamisako, Kohei Ogura, Shigefumi Okamoto, and Ken Kikuchi
- Subjects
n/a ,Therapeutics. Pharmacology ,RM1-950 - Abstract
The authors wish to make the following corrections to this paper [...]
- Published
- 2024
- Full Text
- View/download PDF
5. The fate of non-supersymmetric Gross-Neveu-Yukawa fixed point in two dimensions
- Author
-
Yu Nakayama and Ken Kikuchi
- Subjects
Discrete Symmetries ,Field Theories in Lower Dimensions ,Renormalization Group ,Scale and Conformal Symmetries ,Nuclear and particle physics. Atomic energy. Radioactivity ,QC770-798 - Abstract
Abstract We investigate the fate of the non-supersymmetric Gross-Neveu-Yukawa fixed point found by Fei et al. in 4 − ϵ dimensions with a two-component Majorana fermion continued to two dimensions. Assuming that it is a fermionic minimal model which possesses a chiral ℤ2 symmetry (in addition to fermion number parity) and just two relevant singlet operators, we can zero in on four candidates. Assuming further that the least relevant deformation leads to the supersymmetric Gross-Neveu-Yukawa fixed point (i.e. fermionic tricritical Ising model), we can rule out two of them by matching the spin contents of the preserved topological defect lines. The final candidates are the fermionic (11, 4) minimal model if it is non-unitary, and the fermionic (E 6 , A 10) minimal model if it is unitary. If we further use a constraint from the double braiding relation proposed by one of the authors, the former scenario is preferable.
- Published
- 2023
- Full Text
- View/download PDF
6. First case of a renal cyst infection caused by Desulfovibrio: a case report and literature review
- Author
-
Yoshiki Okamoto, Yoei Miyabe, Momoko Seki, Yusuke Ushio, Keisuke Sato, Eri Kasama, Kenichi Akiyama, Kazunori Karasawa, Keiko Uchida, Ken Kikuchi, Kosaku Nitta, Takahito Moriyama, and Junichi Hoshino
- Subjects
Desulfovibrio species ,Desulfovibrio fairfieldensis ,Renal cyst infection ,Haemodialysis ,Case report ,Diseases of the genitourinary system. Urology ,RC870-923 - Abstract
Abstract Background Genus Desulfovibrio species is a sulphate-reducing anaerobic gram-negative rod that resides in the human oral cavity and intestinal tract. It was reported as the causative pathogen of bacteraemia and abdominal infections, but not renal cyst infection, and Desulfovibrio fairfieldensis has higher pathogenicity than other Desulfovibrio species. Case presentation A 63-year-old man was on haemodialysis for end-stage renal failure due to autosomal dominant polycystic kidney disease. On admission, he had a persistent high-grade fever, right lumbar back pain, and elevated C-reactive protein levels. His blood and urine cultures were negative. He received ciprofloxacin and meropenem; however, there was no clinical improvement. Contrast-enhanced computed tomography and plain magnetic resonance imaging revealed a haemorrhagic cyst at the upper pole of the right kidney. The lesion was drained. Although the drainage fluid culture was negative, D. fairfieldensis was detected in a renal cyst using a polymerase chain reaction. After the renal cyst drainage, he was treated with oral metronidazole and improved without any relapse. Conclusions To the best of our knowledge, this is the first reported case of a renal cyst infection with Desulfovibrio species. D. fairfieldensis is difficult to detect, and polymerase chain reaction tests can detect this bacterium and ensure better management for a successful recovery.
- Published
- 2022
- Full Text
- View/download PDF
7. Antimicrobial Susceptibility to 27 Drugs and the Molecular Mechanisms of Macrolide, Tetracycline, and Quinolone Resistance in Gemella sp.
- Author
-
Michiko Furugaito, Yuko Arai, Yutaka Uzawa, Toshinori Kamisako, Kohei Ogura, Shigefumi Okamoto, and Ken Kikuchi
- Subjects
antimicrobial susceptibility ,Gemella bergeri ,Gemella haemolysans group ,Gemella morbillorum ,Gemella taiwanensis ,Gemella sanguinis ,Therapeutics. Pharmacology ,RM1-950 - Abstract
Gemella is a catalase-negative, facultative anaerobic, Gram-positive coccus that is commensal in humans but can become opportunistic and cause severe infectious diseases, such as infective endocarditis. Few studies have tested the antimicrobial susceptibility of Gemella. We tested its antimicrobial susceptibility to 27 drugs and defined the resistant genes using PCR in 58 Gemella strains, including 52 clinical isolates and six type strains. The type strains and clinical isolates included 22 G. morbillorum, 18 G. haemolysans (GH) group (genetically indistinguishable from G. haemolysans and G. parahaemolysans), 13 G. taiwanensis, three G. sanguinis, and two G. bergeri. No strain was resistant to beta-lactams and vancomycin. In total, 6/22 (27.3%) G. morbillorum strains were erythromycin- and clindamycin-resistant ermB-positive, whereas 4/18 (22.2%) in the GH group, 7/13 (53.8%) G. taiwanensis, and 1/3 (33.3%) of the G. sanguinis strains were erythromycin-non-susceptible mefE- or mefA-positive and clindamycin-susceptible. The MIC90 of minocycline and the ratios of tetM-positive strains varied across the different species—G. morbillorum: 2 µg/mL and 27.3% (6/22); GH group: 8 µg/mL and 27.8% (5/18); G. taiwanensis: 8 µg/mL and 46.2% (6/13), respectively. Levofloxacin resistance was significantly higher in G. taiwanensis (9/13 69.2%) than in G. morbillorum (2/22 9.1%). Levofloxacin resistance was associated with a substitution at serine 83 for leucine, phenylalanine, or tyrosine in GyrA. The mechanisms of resistance to erythromycin and clindamycin differed across Gemella species. In addition, the rate of susceptibility to levofloxacin differed across Gemella sp., and the quinolone resistance mechanism was caused by mutations in GyrA alone.
- Published
- 2023
- Full Text
- View/download PDF
8. Predominance of ST8 and CC1/spa-t1784 methicillin-resistant Staphylococcus aureus isolates in Japan and their genomic characteristics
- Author
-
Kohei Ogura, Daiki Kaji, Masakazu Sasaki, Yoshihito Otsuka, Norihiko Takemoto, Tohru Miyoshi-Akiyama, and Ken Kikuchi
- Subjects
Methicillin-resistant Staphylococcus aureus ,CA-MRSA ,Multilocus sequence typing ,ST1 ,Clonal complex 1 ,Virulence factors ,Microbiology ,QR1-502 - Abstract
ABSTRACT: Objectives: Methicillin-resistant Staphylococcus aureus (MRSA) has become a serious epidemiologic problem worldwide. In this study, we aimed to investigate recently isolated MRSA types and determine their characteristics. Methods: We collected 164 strains isolated from 13 hospitals located in Tokyo and surrounding prefectures. In addition to drug resistance tests, we sequenced whole genomes of the prevalent MRSA clones and analysed their genomic characteristics, such as drug resistance genes, virulence factor genes, and genome arrangements. Results: Multilocus sequencing typing showed that 51% of the SCCmecⅣ MRSA isolates belonged to clonal complex 1 (CC1). Staphylococcus protein A gene (spa) typing showed that 91% of these CC1 isolates could be categorised as t1784 type. These CC1/t1784 isolates possessed genes encoding erythromycin resistance protein, spectinomycin 9-adenylyltransferase, and staphylococcal enterotoxins (SEA, SEI, SEM), but not the pvl gene encoding Panton-Valentine leukocidin. Complete genomic analysis of nine CC1/t1784 isolates showed that they shared an intact phage, which carried no annotated virulence factor genes except for two encoding a hypothetical membrane protein and a teichoic acid biosynthesis protein. No significant genomic rearrangements were observed among the CC1/t1784 isolates. Conclusion: These data and previous reports indicate that this CC1/t1784 clone has been expanding rapidly in Japan without genomic changes.
- Published
- 2022
- Full Text
- View/download PDF
9. Bacteremia caused by Enterobacter asburiae misidentified biochemically as Cronobacter sakazakii and accurately identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry: a case report
- Author
-
Noboru Horinouchi, Seiji Shiota, Takeshi Takakura, Atsushi Yoshida, Ken Kikuchi, Akira Nishizono, and Eishi Miyazaki
- Subjects
Enterobacter asburiae ,Cronobacter sakazakii ,Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry ,Medicine - Abstract
Abstract Background Biochemical analyses of causative bacteria do not always result in clear identification, and new technologies aimed at improving diagnostic accuracy continue to be developed. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry is a rapid and accurate technique for bacterial identification. Misidentification of Cronobacter sakazakii is related to clinical and industrial problems. Here, we encountered a case of rare bacteremia in which the causative organism Enterobacter asburiae was biochemically misidentified as C. sakazakii before being correctly identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Case presentation An 87-year-old Asian man with no diabetes or active disease developed bacteremia and was admitted to our hospital. While the route of infection could not be determined despite various examinations, the clinical course was good following antibiotic therapy. Biochemical analyses identified the causative organism as C. sakazakii, but colonies on the blood agar medium showed a grayish coloration, differing from the yellowish coloration of typical Cronobacter colonies. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry was therefore performed, identifying the bacterium as E. asburiae on three independent analyses. This result was confirmed by multilocus sequence analysis using five housekeeping genes. Conclusions Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry may reduce misidentification of bacteria as C. sakazakii and improve the reporting rate of E. asburiae. This technique should be considered when biochemical bacterial misidentification is suspected.
- Published
- 2022
- Full Text
- View/download PDF
10. Secondary spontaneous pneumothorax in a patient with resistant Mycobacterium abscessus infection and systemic sclerosis-associated interstitial lung disease: A case report
- Author
-
Yoko Nishizawa, Hideki Katsura, Yuka Sasaki, Ryoma Kudo, Aki Kizuki, Ai Horimoto, Motonao Ishikawa, Kae Takagi, Ken Kikuchi, Hiroshi Sakura, Kosaku Nitta, Junichi Hoshino, and Tetsuya Ogawa
- Subjects
Interstitial lung disease ,Mycobacterium abscessus ,Pheumothorax ,Systemic sclerosis ,Clofazimine ,Diseases of the respiratory system ,RC705-779 - Abstract
Mycobacterium abscessus subsp. abscessus (MABA) is refractory and sometimes fatal especially in an immunocompromised patient. Also, MABA-associated pneumothorax is an extremely rare complication. We report a case of MABA pulmonary infection complicated pneumothorax treated successfully. A 69-year-old Japanese female with immunosuppressed systemic sclerosis-associated interstitial lung disease experienced left-sided secondary spontaneous pneumothorax. MABA was detected in the pleural effusion and blood culture. Microbial sensitivity test showed the MABA was sensitive to only amikacin, sitafloxacin, and clofazimine. Combination therapy with these antibiotics including azithromycin achieved remission within three weeks. In the treatment of MABA infection, compliance with microbial sensitivity test is crucial.
- Published
- 2023
- Full Text
- View/download PDF
11. Inhibition of lipid metabolism exerts antitumor effects on rhabdomyosarcoma
- Author
-
Satoshi Miyagaki, Ken Kikuchi, Jun Mori, Gary D. Lopaschuk, Tomoko Iehara, and Hajime Hosoi
- Subjects
cancer metabolism ,lipid metabolism inhibition ,low‐fat diet ,malonyl‐CoA decarboxylase inhibitor ,rhabdomyosarcoma ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Abstract Rhabdomyosarcoma exhibits tumor‐specific energy metabolic changes that include the Warburg effect. Since targeting cancer metabolism is a promising therapeutic approach, we examined the antitumor effects of suppressing lipid metabolism in rhabdomyosarcoma. We suppressed lipid metabolism in rhabdomyosarcoma cells in vitro by administering an inhibitor of malonyl‐CoA decarboxylase, which increases malonyl‐CoA and decreases fatty acid oxidation. Suppression of lipid metabolism in rhabdomyosarcoma cells decreased cell proliferation by inducing cell cycle arrest. Metabolomic analysis showed an increase in glycolysis and inactivation of the pentose phosphate pathway. Immunoblotting analysis revealed upregulated expression of the autophagy marker LC3A/B‐II due to increased phosphorylation of AMP‐activated protein kinase, a nutrient sensor. p21 protein expression level also increased. Inhibition of both lipid metabolism and autophagy suppressed tumor proliferation and increased apoptosis. In vivo studies involved injection of human Rh30 cells into the gastrocnemius muscle of 6‐week‐old female nude mice, which were divided into normal chow and low‐fat diet groups. The mice fed a low‐fat diet for 21 days showed reduced tumor growth compared to normal chow diet‐fed mice. Suppression of lipid metabolism disrupted the equilibrium of the cancer‐specific metabolism in rhabdomyosarcoma, resulting in a tumor growth‐inhibition effect. Therefore, the development of treatments focusing on the lipid dependence of rhabdomyosarcoma is highly promising.
- Published
- 2021
- Full Text
- View/download PDF
12. Reduced B7-H3 expression by PAX3-FOXO1 knockdown inhibits cellular motility and promotes myogenic differentiation in alveolar rhabdomyosarcoma
- Author
-
Takuyo Kanayama, Mitsuru Miyachi, Yohei Sugimoto, Shigeki Yagyu, Ken Kikuchi, Kunihiko Tsuchiya, Tomoko Iehara, and Hajime Hosoi
- Subjects
Medicine ,Science - Abstract
Abstract B7-H3 (also known as CD276) is associated with aggressive characteristics in various cancers. Meanwhile, in alveolar rhabdomyosarcoma (ARMS), PAX3-FOXO1 fusion protein is associated with increased aggressiveness and poor prognosis. In the present study, we explored the relationship between PAX3-FOXO1 and B7-H3 and the biological roles of B7-H3 in ARMS. Quantitative real time PCR and flow cytometry revealed that PAX3-FOXO1 knockdown downregulated B7-H3 expression in all the selected cell lines (Rh-30, Rh-41, and Rh-28), suggesting that PAX3-FOXO1 positively regulates B7-H3 expression. Gene expression analysis revealed that various genes and pathways involved in chemotaxis, INF-γ production, and myogenic differentiation were commonly affected by the knockdown of PAX3-FOXO1 and B7-H3. Wound healing and transwell migration assays revealed that both PAX3-FOXO1 and B7-H3 were associated with cell migration. Furthermore, knockdown of PAX3-FOXO1 or B7-H3 induced myogenin expression in all cell lines, although myosin heavy chain induction varied depending on the cellular context. Our results indicate that PAX3-FOXO1 regulates B7-H3 expression and that PAX3-FOXO1 and B7-H3 are commonly associated with multiple pathways related to an aggressive phenotype in ARMS, such as cell migration and myogenic differentiation block.
- Published
- 2021
- Full Text
- View/download PDF
13. Nationwide surveillance of antimicrobial susceptibility of 509 rapidly growing mycobacteria strains isolated from clinical specimens in Japan
- Author
-
Keisuke Kamada, Atsushi Yoshida, Shigekazu Iguchi, Yuko Arai, Yutaka Uzawa, Satoshi Konno, Masahiro Shimojima, and Ken Kikuchi
- Subjects
Medicine ,Science - Abstract
Abstract This study aimed to identify effective treatments against rapidly growing mycobacteria (RGM) infections by investigating the minimum inhibitory concentrations (MIC) of 24 antimicrobial agents and their molecular mechanisms of resistance. In total, 509 clinical RGM isolates were identified by analyzing the sequences of three housekeeping genes (hsp65, rpoB, and sodA), and their susceptibilities to 24 antimicrobial agents were tested. We also performed sequencing analysis of antimicrobial resistance genes (rrl, rrs, gyrA, and gyrB). To identify Mycobacteroides abscessus group subspecies, we performed PCR-based typing and determined the sequevar of erm(41). We identified 15 RGM species, most of which were susceptible to amikacin and linezolid. Among these species, arbekacin and sitafloxacin had the lowest MIC among the same class of antimicrobials. The MIC of rifabutin for M. abscessus subsp. abscessus (MAB) was lower than that for M. abscessus subsp. massiliense (MMA). The proportion of MAB isolates with MIC ≤ 2 mg/L for rifabutin was significantly higher than that of MMA [MAB: 50/178 (28.1%) vs. MMA: 23/130 (17.7%); p = 0.041]. In summary, our study revealed the antimicrobial susceptibility profile of 15 RGM species isolated in Japan and indicated that arbekacin, sitafloxacin, and rifabutin may be possible therapeutic options for RGM infections.
- Published
- 2021
- Full Text
- View/download PDF
14. Development of non-viral, ligand-dependent, EPHB4-specific chimeric antigen receptor T cells for treatment of rhabdomyosarcoma
- Author
-
Hiroshi Kubo, Shigeki Yagyu, Kayoko Nakamura, Kumiko Yamashima, Akimasa Tomida, Ken Kikuchi, Tomoko Iehara, Yozo Nakazawa, and Hajime Hosoi
- Subjects
EPHB4 ,chimeric antigen receptor ,CAR-T cell therapy ,rhabdomyosarcoma ,piggyBac transposon ,stem cell memory-like T cells ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Ephrin type-B receptor 4 (EPHB4), expressed in tumors including rhabdomyosarcoma, is a suitable target for chimeric antigen receptor (CAR)-T cells. Ligand-independent activation of EPHB4 causes cell proliferation and malignant transformation in rhabdomyosarcoma, whereas ligand-dependent stimulation of EPHB4 induces apoptosis in rhabdomyosarcoma. Therefore, we hypothesized that ligand-based, EPHB4-specific CAR-T cells may kill rhabdomyosarcoma cells without stimulating downstream cell proliferation mechanisms. We developed novel CAR-T cells by targeting EPHB4 via EPHRIN B2, a natural ligand of EPHB4. The generation of EPHB4-CAR-T cells via piggyBac (PB) transposon-based gene transfer resulted in sufficient T cell expansion and CAR positivity (78.5% ± 5.9%). PB-EPHB4-CAR-T cells displayed a dominant stem cell memory fraction (59.4% ± 7.2%) as well as low PD-1 expression (0.60% ± 0.21%) after 14 days of expansion. The PB-EPHB4-CAR-T cells inhibited EPHB4-positive tumor cells without activating cell proliferation downstream of EPHB4, even after multiple tumor re-challenges and suppressed tumor growth in xenograft-bearing mice. Therefore, PB-EPHB4-CAR-T cells possess a memory-rich fraction without early T cell exhaustion and show potential as promising therapeutic agents for treating rhabdomyosarcoma and other EPHB4-positive tumors.
- Published
- 2021
- Full Text
- View/download PDF
15. Geographical distribution and regional differences in 532 clinical isolates of rapidly growing mycobacterial species in Japan
- Author
-
Keisuke Kamada, Atsushi Yoshida, Shigekazu Iguchi, Yuko Arai, Yutaka Uzawa, Satoshi Konno, Masahiro Shimojima, and Ken Kikuchi
- Subjects
Medicine ,Science - Abstract
Abstract Infectious diseases caused by nontuberculous mycobacteria (NTM) are increasingly becoming a major global problem. Additionally, Mycobacteroides abscessus subsp. abscessus (MAB) infections are refractory to macrolides. This study was conducted to investigate the epidemiology of rapidly growing mycobacteria (RGM) species isolated from clinical specimens in Japan and assess differences in the regional distribution of lower respiratory specimens (LRS)- and non-lower respiratory specimens (NLRS)-derived species. 532 strains (427 LRS, 92 NLRS and 15 unknown specimens) were isolated in nine areas of Japan. We collected 418 specimens from Bio Medical Laboratories (BML), Inc., and 114 specimens from 45 hospitals in Japan. Their epidemiological differences were examined according to the specimen type, region, and climate. Fifteen species were identified. The proportion of M. abscessus group (MAG) strains was significantly lower in NLRS than in LRS (35.9% vs. 68.4%). The proportion of MAG strains was higher in northern Japan than in other regions (83.7% vs. 60.5%). Variations in strain abundance among RGM species was evident in regions with a mean annual temperature below 15 °C. We conclude that the proportions of MAG strains differed between NLRS and LRS in Japan. In addition, the mean annual temperature likely influenced the distribution of RGM species.
- Published
- 2021
- Full Text
- View/download PDF
16. Pulmonary infection due to fluoroquinolone-resistant Mycolicibacterium fortuitum: a case report
- Author
-
Kana Kurokawa, Norihiro Harada, Hitoshi Sasano, Haruhi Takagi, Satomi Takei, Ayako Nakamura, Keisuke Kamada, Atsushi Yoshida, Ken Kikuchi, and Kazuhisa Takahashi
- Subjects
Mycolicibacterium fortuitum ,Fluoroquinolone ,Resistance ,DNA gyrase ,gyrA ,Infectious and parasitic diseases ,RC109-216 - Abstract
Abstract Background Mycolicibacterium fortuitum is a species of the rapidly growing mycobacteria that can cause pulmonary infection. It is susceptible to multiple antibiotics both in vitro and in clinical practice, so that any combination of susceptible drugs is effective. However, we encountered a case of infection due to fluoroquinolone-resistant M. fortuitum. In this study, we report the case and describe the mechanism of resistance. Case presentation A 65-year-old man with a history of total gastrectomy and immunosuppressant treatment for rheumatoid arthritis developed a recurrence of pulmonary infection caused by M. fortuitum. He was treated with clarithromycin and levofloxacin as a first-line treatment, based on the favorable susceptibility at that time. After recurrence, a high minimum inhibitory concentration to fluoroquinolones was detected. DNA sequencing of the pathogen showed the substitution of serine for tryptophan at residue 83 in the gyrA gene. He was successfully treated with a combination of other antibiotics. Conclusion This is the first report on the treatment of fluoroquinolone-resistant M. fortuitum and investigation of the mechanism of resistance. We suggest that the susceptibility test remains effective for determining the next line of treatment after a pathogen has acquired resistance, and resistance to fluoroquinolones in M. fortuitum can be attributed to a single change of amino acid.
- Published
- 2020
- Full Text
- View/download PDF
17. Early and noninvasive diagnosis using serological antigen biomarkers in chronic invasive fungal rhinosinusitis
- Author
-
Ayuko Oba, Shin Ito, Hiroko Okada, Takashi Anzai, Ken Kikuchi, and Katsuhisa Ikeda
- Subjects
chronic invasive fungal rhinosinusitis ,1 3-b-d-glucan assay ,polymerase chain reaction ,histopathology ,Otorhinolaryngology ,RF1-547 - Abstract
Background: Chronic invasive form of fungal rhinosinusitis (FRS) is characterized by the invasion of fungal organisms into the sinonasal mucosa in the background of diabetes mellitus and corticosteroid treatment. Although the histopathology has traditionally been used to make a proven diagnosis of invasive fungal infections, the dependence on tissue samples and the slow turnaround time hamper the early confirmation of such infections. Methodology: This is a retrospective case series conducted over 6 years. All patients with a chronic course and immunosuppressive background of FRS diagnosed by radiologic imaging and treated with endoscopic sinus surgery were eligible for inclusion. Data were collected through medical records, including basic characteristics, symptoms and signs, imaging findings, laboratory investigations, pathology, treatment, and outcomes. Results: Fifteen patients with chronic course and immunosuppressive background of FRS diagnosed by radiologic imaging were identified. High values of 1,3-b-D-glucan (BDG) assay were recognized in 5 patients, whereas the other 10 patients with negative findings in the BDG assay showed sinus mycetomas. All the 5 patients showing significant elevations of serum BDG showed positive findings in the polymerase chain reaction (PCR), but only 2 patients were positive in the histopathology. The findings of the BDG assay were consistent with those of the PCR method, which was superior in sensitivity to the histopathology. Conclusion: We first applied BDG assay as a diagnostic tool for chronic invasive FRS. The BDG assay may be useful to distinguish chronic invasive FRS, including its early stage, from noninvasive mycetoma, contributing to timely treatment.
- Published
- 2020
- Full Text
- View/download PDF
18. Oncogenic role of HMGA2 in fusion-negative rhabdomyosarcoma cells
- Author
-
Kazutaka Ouchi, Mitsuru Miyachi, Shigeki Yagyu, Ken Kikuchi, Yasumichi Kuwahara, Kunihiko Tsuchiya, Tomoko Iehara, and Hajime Hosoi
- Subjects
HMGA2 ,Fusion-negative rhabdomyosarcoma ,Netropsin ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 ,Cytology ,QH573-671 - Abstract
Abstract Background Rhabdomyosarcoma (RMS) is the most common pediatric soft tissue sarcoma. There are two subtypes, fusion gene-positive RMS (FP-RMS) and fusion gene-negative RMS (FN-RMS), depending on the presence of a fusion gene, either PAX3-FOXO1 or PAX7-FOXO1. These fusion genes are thought to be oncogenic drivers of FP-RMS. By contrast, the underlying mechanism of FN-RMS has not been thoroughly investigated. It has recently been shown that HMGA2 is specifically positive in pathological tissue from FN-RMS, but the role of HMGA2 in FN-RMS remains to be clarified. Methods In this study, we used FN-RMS cell lines to investigate the function of HMGA2. Gene expression, cell growth, cell cycle, myogenic differentiation, tumor formation in vivo, and cell viability under drug treatment were assessed. Results We found that HMGA2 was highly expressed in FN-RMS cells compared with FP-RMS cells and that knockdown of HMGA2 in FN-RMS cells inhibited cell growth and induced G1 phase accumulation in the cell cycle and myogenic differentiation. Additionally, we showed using both gain-of-function and loss-of-function assays that HMGA2 was required for tumor formation in vivo. Consistent with these findings, the HMGA2 inhibitor netropsin inhibited the cell growth of FN-RMS. Conclusions Our results suggest that HMGA2 has important role in the oncogenicity of FP-RMS and may be a potential therapeutic target in patients with FN-RMS.
- Published
- 2020
- Full Text
- View/download PDF
19. Recurrent infections caused by different species of Neisseria bacteria in a patient with complement seven deficiency
- Author
-
Michiyo Masuda, Mutsumi Iijima, Yusuke Ainoda, Yuji Hirai, Ken Kikuchi, and Kazuo Kitagawa
- Subjects
Complement 7 deficiency ,Neisseria meningitidis infection ,Neisseria gonorrhoeae meningitis ,Neurology. Diseases of the nervous system ,RC346-429 - Published
- 2021
- Full Text
- View/download PDF
20. Efficacy of adjuvant chemotherapy with S-1 in stage II oral squamous cell carcinoma patients: A comparative study using the propensity score matching method.
- Author
-
Ryoji Yoshida, Masashi Nagata, Akiyuki Hirosue, Kenta Kawahara, Masafumi Nakamoto, Masatoshi Hirayama, Nozomu Takahashi, Yuichiro Matsuoka, Junki Sakata, Hikaru Nakashima, Hidetaka Arita, Akimitsu Hiraki, Masanori Shinohara, Ken Kikuchi, and Hideki Nakayama
- Subjects
Medicine ,Science - Abstract
It has been reported that 20% of early-stage oral squamous cell carcinoma (OSCC) patients treated with surgery alone (SA) may exhibit postoperative relapse within 2-3 years and have poor prognoses. We aimed to determine the safety of S-1 adjuvant chemotherapy and the potential differences in the disease-free survival (DFS) between patients with T2N0 (stage II) OSCC treated with S-1 adjuvant therapy (S-1) and those treated with SA. This single-center retrospective cohort study was conducted at Kumamoto University, between April 2004 and March 2012, and included 95 patients with stage II OSCC. The overall cohort (OC), and propensity score-matched cohort (PSMC) were analyzed. In the OC, 71 and 24 patients received SA and S-1, respectively. The time to relapse (TTR), DFS, and overall survival were better in the S-1 group, but the difference was not significant. In the PSMC, 20 patients each received SA and S-1. The TTR was significantly lower in the S-1 group than in the SA group, while the DFS was significantly improved in the former. S-1 adjuvant chemotherapy may be more effective than SA in early-stage OSCC.
- Published
- 2020
- Full Text
- View/download PDF
21. Potency of gastrointestinal colonization and virulence of Candida auris in a murine endogenous candidiasis.
- Author
-
Masahiro Abe, Harutaka Katano, Minoru Nagi, Yoshitsugu Higashi, Yuko Sato, Ken Kikuchi, Hideki Hasegawa, and Yoshitsugu Miyazaki
- Subjects
Medicine ,Science - Abstract
BackgroundCandida auris infections have recently emerged worldwide, and this species is highly capable of colonization and is associated with high levels of mortality. However, strain-dependent differences in colonization capabilities and virulence have not yet been reported.ObjectivesIn the present study, we aimed to clarify the differences between clinically isolated invasive and non-invasive strains of C. auris.MethodsWe evaluated colonization, dissemination, and survival rates in wild C57BL/6J mice inoculated with invasive or non-invasive strains of C. auris under cortisone acetate immunosuppression, comparing with those of Candida albicans and Candida glabrata infections. We also evaluated the potency of biofilm formation.ResultsStool fungal burdens were significantly higher in mice inoculated with the invasive strains than in those infected with the non-invasive strain. Along with intestinal colonization, liver and kidney fungal burdens were also significantly higher in mice inoculated with the invasive strains. In addition, histopathological findings revealed greater dissemination and colonization of the invasive strains. Regarding biofilm-forming capability, the invasive strain of C. auris exhibited a significantly higher capacity of producing biofilms. Moreover, inoculation with the invasive strains resulted in significantly greater loss of body weight than that noted following infection with the non-invasive strain.ConclusionsInvasive strains showed higher colonization capability and rates of dissemination from gastrointestinal tracts under cortisone acetate immunosuppression than non-invasive strains, although the mortality rates caused by C. auris were lower than those caused by C. albicans.
- Published
- 2020
- Full Text
- View/download PDF
22. Purpura fulminans with Lemierre’s syndrome caused by Gemella bergeri and Eikenella corrodens: a case report
- Author
-
Toshinobu Yamagishi, Mayu Hikone, Kazuhiro Sugiyama, Takahiro Tanabe, Yasuhiro Wada, Michiko Furugaito, Yuko Arai, Yutaka Uzawa, Ryo Mizushima, Keisuke Kamada, Yasutomo Itakura, Shigekazu Iguchi, Atsushi Yoshida, Ken Kikuchi, and Yuichi Hamabe
- Subjects
Eikenella corrodens ,Gemella bergeri ,Lemierre’s syndrome ,MALDI-TOF MS ,Purpura fulminans ,Septic shock ,Infectious and parasitic diseases ,RC109-216 - Abstract
Abstract Background Gemella bergeri is one of the nine species of the genus Gemella and is relatively difficult to identify. We herein describe the first case of septic shock due to a Gemella bergeri coinfection with Eikenella corrodens. Case presentation A 44-year-old Asian man with a medical history of IgG4-related ophthalmic disease who was prescribed corticosteroids (prednisolone) presented to our hospital with dyspnea. On arrival, he was in shock, and a purpuric eruption was noted on both legs. Contrast enhanced computed tomography showed fluid retention at the right maxillary sinus, left lung ground glass opacity, and bilateral lung irregular opacities without cavitation. Owing to suspected septic shock, fluid resuscitation and a high dose of vasopressors were started. In addition, meropenem, clindamycin, and vancomycin were administered. Repeat computed tomography confirmed left internal jugular and vertebral vein thrombosis. Following this, the patient was diagnosed with Lemierre’s syndrome. Furthermore, he went into shock again on day 6 of hospitalization. Additional soft tissue infections were suspected; therefore, bilateral below the knee amputations were performed for source control. Cultures of the exudates from skin lesions and histopathological samples did not identify any pathogens, and histopathological findings showed arterial thrombosis; therefore it was concluded that the second time shock was associated with purpura fulminans. Following this, his general status improved. He was transferred to another hospital for rehabilitation. The blood culture isolates were identified as Gemella bergeri and Eikenella corrodens. Gemella bergeri was identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry and confirmed by 16S rRNA gene sequencing later. The primary focus of the infection was thought to be in the right maxillary sinus, because the resolution of the fluid retention was confirmed by repeat computed tomography. Conclusions Gemella bergeri can be the causative pathogen of septic shock. If this pathogen cannot be identified manually or through commercial phenotypic methods, 16S rRNA gene sequencing should be considered.
- Published
- 2018
- Full Text
- View/download PDF
23. Subcutaneous abscesses caused by Trichophyton rubrum in the unilateral groin of an immunocompromised patient: A case report
- Author
-
Utako Okata-Karigane, Yasuki Hata, Emiko Watanabe-Okada, Shunichi Miyakawa, Michi Ota, Yutaka Uzawa, Shigekazu Iguchi, Atsushi Yoshida, and Ken Kikuchi
- Subjects
Medicine (General) ,R5-920 ,Biology (General) ,QH301-705.5 - Abstract
A 60-year-old Japanese man presented with multiple subcutaneous nodules in his left groin. Histologically, the nodules consisted of suppurative granulomas and abscesses not involving the hair follicles. Trichophyton rubrum TWCC57922 was detected by fungal culture and polymerase chain reaction (PCR) sequencing of the rDNA genes. We diagnosed these nodules as deeper dermal dermatophytosis, a rare form of invasive dermatophytosis. He was treated with terbinafine. We compared these findings with previous reports of deep dermal dermatophytosis. Keywords: Dermatophyte infection, Deeper dermal dermatophytosis, Abscess, Granuloma, Trichophyton rubrum
- Published
- 2018
- Full Text
- View/download PDF
24. Fatal Fournier’s gangrene caused by Clostridium ramosum in a patient with central diabetes insipidus and insulin-dependent diabetes mellitus: a case report
- Author
-
Noriyoshi Takano, Midori Sasaki Yatabe, Junichi Yatabe, Masaaki Kato, Daisuke Sueoka, Shigekazu Iguchi, Atsushi Yoshida, Yutaka Uzawa, Ken Kikuchi, Kimitaka Tani, Shinpei Ogawa, Michio Itabashi, Masakazu Yamamoto, Daisuke Watanabe, Takashi Ando, Satoshi Morimoto, and Atsuhiro Ichihara
- Subjects
Fournier’s gangrene ,Necrotizing fasciitis ,Opportunistic infection ,Clostridium ramosum ,Infectious and parasitic diseases ,RC109-216 - Abstract
Abstract Background Clostridium ramosum is a generally non-pathogenic enteric anaerobe, and Fournier’s gangrene is a rare necrotizing soft tissue infection with male predisposition affecting the perineum and the genital area. We report, to our knowledge, the first case of Fournier’s gangrene caused by C. ramosum in a female patient with multiple underlying conditions. Case presentation A 44-year-old woman with a 6-year history of insulin-dependent diabetes mellitus after total pancreatectomy and an 11-year history of central diabetes insipidus developed a pain in the genital area after a month of urinary catheter use. The lower abdominal pain worsened gradually over 2 weeks, and the pain, general fatigue, and loss of appetite prompted the patient’s hospital admission. As she had severe edema in her pelvic and bilateral femoral areas, ceftriaxone was started empirically after collecting two sets of blood cultures. On hospital day 2, CT examination revealed the presence of necrotizing faciitis in the genital and pelvic areas, and the antibiotics were changed to a combination of meropenem, vancomycin, and clindamycin. Gram-positive cocci and gram-positive rods were isolated from blood cultures, which were finally identified as Streptococcus constellatus and C. ramosum using superoxide dismutase and 16S rDNA sequencing. An emergent surgery was performed on hospital day 2 to remove the affected tissue. Despite undergoing debridement and receiving combined antimicrobial chemotherapies, the patient’s clinical improvement remained limited. The patient’s condition continued to deteriorate, and she eventually died on hospital day 8. In the present case, the underlying diabetes mellitus, urinary incontinence due to central diabetes insipidus, undernutrition, and edema served as the predisposing conditions. Conclusions C. ramosum is a potentially opportunistic pathogen among immunosuppressed persons and a rare cause of necrotizing fasciitis.
- Published
- 2018
- Full Text
- View/download PDF
25. A Strategy for Hospital Pharmacists to Control Antimicrobial Resistance (AMR) in Japan
- Author
-
Yukihiro Hamada, Fumiya Ebihara, and Ken Kikuchi
- Subjects
antimicrobial stewardship ,antifungal stewardship ,strategy of pharmacist ,therapeutic drug monitoring ,pharmacokinetics/pharmacodynamics ,Therapeutics. Pharmacology ,RM1-950 - Abstract
In Japan, there is concern regarding the relation between the inappropriate use of antibiotics and antibiotic resistance (AMR). Increased bacterial resistance is due in part to the inappropriate use of antimicrobial agents. The support of the pharmacist becomes important, and there is growing interest in antimicrobial stewardship to promote the appropriate and safe use of antimicrobials needed for the optimal selection of drugs, doses, durations of therapy, therapeutic drug monitoring (TDM), and implementations of cost containment strategies in Japan. Pharmacists should strive to disseminate the concept of “choosing wisely” in relation to all medicines, implement further interventions, and put them into practice. In this article, we present data for antimicrobial stewardship and Japan’s AMR action plan, focusing on how pharmacists should be involved in enabling physicians to choose antimicrobials wisely.
- Published
- 2021
- Full Text
- View/download PDF
26. Gram-negative rod bacteremia after cardiovascular surgery: Clinical features and prognostic factors
- Author
-
Sayaka Tago, Yuji Hirai, Yusuke Ainoda, Takahiro Fujita, and Ken Kikuchi
- Subjects
cardiovascular surgery ,graft replacement ,Gram-negative rod bacteremia ,multivariate analyses ,prognostic factor ,retrospective study ,Microbiology ,QR1-502 - Abstract
Background/Purpose: Our aim was to describe the clinical features and prognostic factors of Gram-negative rod bacteremia (GNRB) after cardiovascular surgery (CVS). Methods: This retrospective observational study included adults with GNRB onset within 100 days after CVS at a single institution from April 2004 to May 2013. Clinical data regarding episodes of GNRB were collected from patients' medical charts. Those having polymicrobial bacteremia with a bacterium other than a GNR were excluded. Results: Among 2017 CVS patients, GNRB occurred in 78. Klebsiella, Pseudomonas aeruginosa, Enterobacter, and Escherichia coli were the most commonly isolated organisms. Graft replacement was the most common surgical procedure in patients with GNRB after CVS (44.9%). Prophylaxis antibiotics were ampicillin/sulbactam (76.9%), and vancomycin (12.8%). The crude 90-day mortality rate was 21.8%, and the mean Acute Physiology and Chronic Health Evaluation II score was 15.6 (range, 3–39). In 34.6% of patients, the same GNR species were isolated from other samples within 30 days of GNRB occurrence. Multivariate analysis indicated that P. aeruginosa bacteremia [odds ratio (OR), 175; confidence interval (CI), 2.40–1270; p = 0.0182], Acute Physiology and Chronic Health Evaluation II scores of ≥ 25 (OR 76.2; CI 1.04–5580; p = 0.0479), and vancomycin for prophylaxis (OR 45.4; CI 1.02–202; p = 0.0488) were significant independent prognostic factors associated with death due to GNRB after CVS. Conclusion: Graft replacement was the most common surgical procedure in patients with GNRB after CVS. Empirical antibiotics covering Gram-negative rods including P. aeruginosa should be considered if bacteremia is suspected in unstable patients after CVS.
- Published
- 2017
- Full Text
- View/download PDF
27. Chronic otitis media caused by Mycobacterium abscessus spp. massiliense treated with tigecycline in a 10-year-old child
- Author
-
Shota Myojin, Kahoru Fukuoka, Asako Kanemaru, Shintaro Baba, Yuki Okamoto, Hiromichi Suzuki, Keisuke Kamada, Atsushi Yoshida, Ken Kikuchi, and Yuho Horikoshi
- Subjects
Infectious and parasitic diseases ,RC109-216 - Abstract
Mycobacterium abscessus is one of the most pathogenic and chemotherapy-resistant rapidly growing mycobacteria. This Mycobacterium should always be considered as a possible cause of chronic otitis media in children, and treatment might be challenging because of its resistance to multiple antibiotics. There are no reports describing the therapeutic use of tigecycline for the treatment of chronic otitis media caused by M. abscessus. A 10-year-old boy was referred to Tokyo Metropolitan Children’s Medical Center with a 7-year history of recurrent otitis media despite treatment with antibiotics and ventilation tubes. Cultures of the otorrhea yielded Mycobacterium abscessus spp. massiliense, and it showed multiple and high-level resistance. The boy required surgery and underwent initial treatment with clarithromycin, amikacin, and tigecycline for 4 weeks. He experienced emesis as a side-effect of tigecycline, which was well controlled with ondansetron. He was treated successfully with 3 months of subsequent oral clarithromycin and linezolid. This is the first pediatric case of chronic otitis media caused by M. abscessus treated with a tigecycline-containing regimen. Although the therapeutic use of tigecycline remains controversial, especially in the pediatric population, it can be an acceptable option in the treatment of chronic otitis media caused by M. abscessus. Keywords: Mycobacterium abscessus, Chronic otitis media, Tigecycline
- Published
- 2018
- Full Text
- View/download PDF
28. Clade II Candida auris possess genomic structural variations related to an ancestral strain.
- Author
-
Tsuyoshi Sekizuka, Shigekazu Iguchi, Takashi Umeyama, Yuba Inamine, Koichi Makimura, Makoto Kuroda, Yoshitsugu Miyazaki, and Ken Kikuchi
- Subjects
Medicine ,Science - Abstract
Candida auris is an invasive and multidrug-resistant ascomycetous yeast that is under global surveillance. All clinical cases of C. auris infection diagnosed from 1997 to 2019 in Japan were non-invasive and sporadic otitis media cases. In the present study, we performed whole-genome sequencing of seven C. auris strains isolated from patients with otitis media in Japan, all of which belonged to clade II. Comparative genome analysis using the high-quality draft genome sequences JCM 15448T revealed that single nucleotide variations (SNVs), clade-specific accessory genes, and copy number variations (CNVs) were identified in each C. auris clade. A total of 61 genes involved in cell wall and stress response-related functions was absent in clade II, and the pattern of conserved CNVs in each clade was more stable in clade II than in other clades. Our data suggest that the genomic structural diversity is stable in C. auris isolated from each biogeographic location, and Japanese strains isolated from patients with otitis media might belong to an ancestral type of C. auris. One Japanese strain, TWCC 58362, with reduced susceptibility to fluconazole, exhibited no mutation in ergosterol biosynthesis-related genes (ERG). However, TWCC 58362-specific variations, including SNVs, indels, and CNVs were detected, suggesting that gene duplication events in C. auris might contribute to antifungal drug resistance. Taken together, we demonstrated that genomic structural variations in C. auris could correlate to geographical dissemination, epidemiology, lesions in the host, and antifungal resistance.
- Published
- 2019
- Full Text
- View/download PDF
29. Anomalous transport independent of gauge fields
- Author
-
Mamiya Kawaguchi and Ken Kikuchi
- Subjects
Physics ,QC1-999 - Abstract
We show that three-dimensional trace anomalies lead to new universal anomalous transport effects on a conformally flat space-time with background scalar fields. In contrast to conventional anomalous transports in quantum chromodynamics or quantum electrodynamics, our current is independent of background gauge fields. Therefore, our anomalous transport survives even in the absence of vectorlike external sources. By manipulating background fields, we suggest a setup to detect our anomalous transport. If one turns on scalar couplings in a finite interval and considers a conformal factor depending just on (conformal) time, we find anomalous transport localized at the interfaces of the interval flows perpendicularly to the interval. The magnitude of the currents is the same on the two interfaces but with opposite directions. Without the assumption on scalar couplings, and only assuming the conformal factor depending solely on (conformal) time as usually done in cosmology, one also finds the three-dimensional Hubble parameter naturally appears in our current.
- Published
- 2020
- Full Text
- View/download PDF
30. Edwardsiella tarda Bacteremia. A Rare but Fatal Water- and Foodborne Infection: Review of the Literature and Clinical Cases from a Single Centre
- Author
-
Yuji Hirai, Sayaka Asahata-Tago, Yusuke Ainoda, Takahiro Fujita, and Ken Kikuchi
- Subjects
Infectious and parasitic diseases ,RC109-216 ,Microbiology ,QR1-502 - Abstract
BACKGROUND: Edwardsiella tarda bacteremia (ETB) can be a fatal disease in humans.
- Published
- 2015
- Full Text
- View/download PDF
31. Incidental diagnosis of oxyuriasis through a colonoscopy
- Author
-
Shigekazu Iguchi, Yuji Hirai, Yusuke Ainoda, Noriko Isoda, Hitomi Miura, Hiroto Egawa, Masakazu Yamamoto, and Ken Kikuchi
- Subjects
Enterobius vermicularis ,Colonoscopy ,“Scotch-tape” test ,Oxyuriasis ,Infectious and parasitic diseases ,RC109-216 - Published
- 2016
- Full Text
- View/download PDF
32. Potential Impact of Rapid Blood Culture Testing for Gram-Positive Bacteremia in Japan with the Verigene Gram-Positive Blood Culture Test
- Author
-
Ken Kikuchi, Mari Matsuda, Shigekazu Iguchi, Tomonori Mizutani, Keiichi Hiramatsu, Michiru Tega-Ishii, Kaori Sansaka, Kenta Negishi, Kimie Shimada, Jun Umemura, Shigeyuki Notake, Hideji Yanagisawa, Hiroshi Takahashi, Reiko Yabusaki, Hideki Araoka, and Akiko Yoneyama
- Subjects
Infectious and parasitic diseases ,RC109-216 ,Microbiology ,QR1-502 - Abstract
Background. Early detection of Gram-positive bacteremia and timely appropriate antimicrobial therapy are required for decreasing patient mortality. The purpose of our study was to evaluate the performance of the Verigene Gram-positive blood culture assay (BC-GP) in two special healthcare settings and determine the potential impact of rapid blood culture testing for Gram-positive bacteremia within the Japanese healthcare delivery system. Furthermore, the study included simulated blood cultures, which included a library of well-characterized methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) isolates reflecting different geographical regions in Japan. Methods. A total 347 BC-GP assays were performed on clinical and simulated blood cultures. BC-GP results were compared to results obtained by reference methods for genus/species identification and detection of resistance genes using molecular and MALDI-TOF MS methodologies. Results. For identification and detection of resistance genes at two clinical sites and simulated blood cultures, overall concordance of BC-GP with reference methods was 327/347 (94%). The time for identification and antimicrobial resistance detection by BC-GP was significantly shorter compared to routine testing especially at the cardiology hospital, which does not offer clinical microbiology services on weekends and holidays. Conclusion. BC-GP generated accurate identification and detection of resistance markers compared with routine laboratory methods for Gram-positive organisms in specialized clinical settings providing more rapid results than current routine testing.
- Published
- 2017
- Full Text
- View/download PDF
33. Diversity and microevolution of CRISPR loci in Helicobacter cinaedi.
- Author
-
Junko Tomida, Yuji Morita, Keigo Shibayama, Ken Kikuchi, Tomohiro Sawa, Takaaki Akaike, and Yoshiaki Kawamura
- Subjects
Medicine ,Science - Abstract
Helicobacter cinaedi is associated with nosocomial infections. The CRISPR-Cas system provides adaptive immunity against foreign genetic elements. We investigated the CRISPR-Cas system in H. cinaedi to assess the potential of the CRISPR-based microevolution of H. cinaedi strains. A genotyping method based on CRISPR spacer organization was carried out using 42 H. cinaedi strains. The results of sequence analysis showed that the H. cinaedi strains used in this study had two CRISPR loci (CRISPR1 and CRISPR2). The lengths of the consensus direct repeat sequences in CRISPR1 and CRISPR2 were both 36 bp-long, and 224 spacers were found in the 42 H. cinaedi strains. Analysis of the organization and sequence similarity of the spacers of the H. cinaedi strains showed that CRISPR arrays could be divided into 7 different genotypes. Each genotype had a different ancestral spacer, and spacer acquisition/deletion events occurred while isolates were spreading. Spacer polymorphisms of conserved arrays across the strains were instrumental for differentiating closely-related strains collected from the same hospital. MLST had little variability, while the CRISPR sequences showed remarkable diversity. Our data revealed the structural features of H. cinaedi CRISPR loci for the first time. CRISPR sequences constitute a valuable basis for genotyping, provide insights into the divergence and relatedness between closely-related strains, and reflect the microevolutionary process of H. cinaedi.
- Published
- 2017
- Full Text
- View/download PDF
34. Fournier’S Gangrene Caused by Listeria Monocytogenes as the Primary Organism
- Author
-
Sayaka Asahata, Yuji Hirai, Yusuke Ainoda, Takahiro Fujita, Yumiko Okada, and Ken Kikuchi
- Subjects
Infectious and parasitic diseases ,RC109-216 ,Microbiology ,QR1-502 - Abstract
A 70-year-old man with a history of tongue cancer presented with Fournier’s gangrene caused by Listeria monocytogenes serotype 4b. Surgical debridement revealed undiagnosed rectal adenocarcinoma. The patient did not have an apparent dietary or travel history but reported daily consumption of sashimi (raw fish).
- Published
- 2015
- Full Text
- View/download PDF
35. Rapid Acquisition of Linezolid Resistance in Methicillin-Resistant Staphylococcus aureus: Role of Hypermutation and Homologous Recombination.
- Author
-
Shigekazu Iguchi, Tomonori Mizutani, Keiichi Hiramatsu, and Ken Kikuchi
- Subjects
Medicine ,Science - Abstract
BACKGROUND:We previously reported the case of a 64-year-old man with mediastinitis caused by Staphylococcus aureus in which the infecting bacterium acquired linezolid resistance after only 14 days treatment with linezolid. We therefore investigated relevant clinical isolates for possible mechanisms of this rapid acquisition of linezolid resistance. METHODS:Using clinical S. aureus isolates, we assessed the in vitro mutation rate and performed stepwise selection for linezolid resistance. To investigate homologous recombination, sequences were determined for each of the 23S ribosomal RNA (23S rRNA) loci; analyzed sequences spanned the entirety of each 23S rRNA gene, including domain V, as well as the 16S-23S intergenic spacer regions. We additionally performed next-generation sequencing on clinical strains to identify single-nucleotide polymorphisms compared to the N315 genome. RESULTS:Strains isolated from the patient prior to linezolid exposure (M5-M7) showed higher-level linezolid resistance than N315, and the pre-exposure strain (M2) exhibited more rapid acquisition of linezolid resistance than did N315. However, the mutation rates of these and contemporaneous clinical isolates were similar to those of N315, and the isolates did not exhibit any mutations in hypermutation-related genes. Sequences of the 23S rRNA genes and 16S-23S intergenic spacer regions were identical among the pre- and post-exposure clinical strains. Notably, all of the pre-exposure isolates harbored a recQ missense mutation (Glu69Asp) with respect to N315; such a lesion may have affected short sequence recombination (facilitating, for example, recombination among rrn loci). We hypothesize that this mechanism contributed to rapid acquisition of linezolid resistance. CONCLUSIONS:Hypermutation and homologous recombination of the ribosomal RNA genes, including 23S rRNA genes, appear not to have been sources of the accelerated acquisition of linezolid resistance observed in our clinical case. Increased frequency of short sequence recombination may have resulted from a recQ variant in the infecting organism.
- Published
- 2016
- Full Text
- View/download PDF
36. Cell-cycle dependent expression of a translocation-mediated fusion oncogene mediates checkpoint adaptation in rhabdomyosarcoma.
- Author
-
Ken Kikuchi, Simone Hettmer, M Imran Aslam, Joel E Michalek, Wolfram Laub, Breelyn A Wilky, David M Loeb, Brian P Rubin, Amy J Wagers, and Charles Keller
- Subjects
Genetics ,QH426-470 - Abstract
Rhabdomyosarcoma is the most commonly occurring soft-tissue sarcoma in childhood. Most rhabdomyosarcoma falls into one of two biologically distinct subgroups represented by alveolar or embryonal histology. The alveolar subtype harbors a translocation-mediated PAX3:FOXO1A fusion gene and has an extremely poor prognosis. However, tumor cells have heterogeneous expression for the fusion gene. Using a conditional genetic mouse model as well as human tumor cell lines, we show that that Pax3:Foxo1a expression is enriched in G2 and triggers a transcriptional program conducive to checkpoint adaptation under stress conditions such as irradiation in vitro and in vivo. Pax3:Foxo1a also tolerizes tumor cells to clinically-established chemotherapy agents and emerging molecularly-targeted agents. Thus, the surprisingly dynamic regulation of the Pax3:Foxo1a locus is a paradigm that has important implications for the way in which oncogenes are modeled in cancer cells.
- Published
- 2014
- Full Text
- View/download PDF
37. Pneumatic Plantar Stimulation Device Replicating Manual Therapy Improves Lateral Stability in Standing Posture.
- Author
-
Qi An, Hiroyuki Hamada, Shigeki Maruta, Yuki Abe, Kenichi Takada, Ken Kikuchi, Hiroshi Yamakawa, Hajime Asama, and Atsushi Yamashita
- Published
- 2024
- Full Text
- View/download PDF
38. MDM2 Amplification and PI3KCA Mutation in a Case of Sclerosing Rhabdomyosarcoma
- Author
-
Ken Kikuchi, George R. Wettach, Christopher W. Ryan, Arthur Hung, Jody E. Hooper, Carol Beadling, Andrea Warrick, Christopher L. Corless, Susan B. Olson, Charles Keller, and Atiya Mansoor
- Subjects
Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
A rare sclerosing variant of rhabdomyosarcoma characterized by prominent hyalinization and pseudovascular pattern has recently been described as a subtype biologically distinct from embryonal, alveolar, and pleomorphic forms. We present cytogenetic and molecular findings as well as experimental studies of an unusual case of sclerosing rhabdomyosarcoma. The primary lesion arose within the plantar subcutaneous tissue of the left foot of an otherwise healthy 23-year-old male who eventually developed pulmonary nodules despite systemic chemotherapy. Two genetic abnormalities identified in surgical and/or autopsy samples of the tumor were introduced into 10T1/2 murine fibroblasts to determine whether these genetic changes cooperatively facilitated transformation and growth. Cytogenetic analysis revealed a complex abnormal hyperdiploid clone, and MDM2 gene amplification was confirmed by fluorescence in situ hybridization. Cancer gene mutation screening using a combination of multiplexed PCR and mass spectroscopy revealed a PIK3CA exon 20 H1047R mutation in the primary tumor, lung metastasis, and liver metastasis. However, this mutation was not cooperative with MDM2 overexpression in experimental assays for transformation or growth. Nevertheless, MDM2 and PIK3CA are genes worthy of further investigation in patients with sclerosing rhabdomyosarcoma and might be considered in the enrollment of these patients into clinical trials of targeted therapeutics.
- Published
- 2013
- Full Text
- View/download PDF
39. Early and Definitive Diagnosis of Toxic Shock Syndrome by Detection of Marked Expansion of T-Cell-Receptor Vβ2-Positive T Cells
- Author
-
Yoshio Matsuda, Hidehito Kato, Ritsuko Yamada, Hiroya Okano, Hiroaki Ohta, Ken’ichi Imanishi, Ken Kikuchi, Kyouichi Totsuka, and Takehiko Uchiyama
- Subjects
toxic shock syndrome ,T-cell-receptor ,Vβ2-positive T cells ,dispatch ,Japan ,Medicine ,Infectious and parasitic diseases ,RC109-216 - Abstract
We describe two cases of early toxic shock syndrome, caused by the superantigen produced from methicillin-resistant Staphylococcus aureus and diagnosed on the basis of an expansion of T-cell-receptor Vβ2-positive T cells. One case-patient showed atypical symptoms. Our results indicate that diagnostic systems incorporating laboratory techniques are essential for rapid, definitive diagnosis of toxic shock syndrome.
- Published
- 2003
- Full Text
- View/download PDF
40. Genetic diversity of staphylocoagulase genes (coa): insight into the evolution of variable chromosomal virulence factors in Staphylococcus aureus.
- Author
-
Shinya Watanabe, Teruyo Ito, Takashi Sasaki, Shanshuang Li, Ikuo Uchiyama, Kozue Kishii, Ken Kikuchi, Robert Leo Skov, and Keiichi Hiramatsu
- Subjects
Medicine ,Science - Abstract
BackgroundThe production of staphylocoagulase (SC) causing the plasma coagulation is one of the important characteristics of Staphylococcus aureus. Although SCs have been classified into 10 serotypes based on the differences in the antigenicity, genetic bases for their diversities and relatedness to chromosome types are poorly understood.Methodology/principal findingsWe compared the nucleotide sequences of 105 SC genes (coa), 59 of which were determined in this study. D1 regions, which contain prothrombin-activating and -binding domains and are presumed to be the binding site of each type-specific antiserum, were classified into twelve clusters having more than 90% nucleotide identities, resulting to create two novel SC types, XI and XII, in addition to extant 10 types. Nine of the twelve SC types were further subdivided into subtypes based on the differences of the D2 or the central regions. The phylogenetical relations of the D1 regions did not correlate exactly with either one of agr types and multilocus sequence types (STs). In addition, genetic analysis showed that recombination events have occurred in and around coa. So far tested, STs of 126 S. aureus strains correspond to the combination of SC type and agr type except for the cases of CC1 and CC8, which contained two and three different SC types, respectively.ConclusionThe data suggested that the evolution of coa was not monophyletic in the species. Chromosomal recombination had occurred at coa and agr loci, resulting in the carriage of the combinations of allotypically different important virulence determinants in staphylococcal chromosome.
- Published
- 2009
- Full Text
- View/download PDF
41. Analysis of Efficiency-Limiting Factors Resulting from Transistor Current Source on Class-F and Inverse Class-F Power Amplifiers.
- Author
-
Hiroshi Yamamoto, Ken Kikuchi, Valeria Vadalà, Gianni Bosi, Antonio Raffo, and Giorgio Vannini
- Published
- 2022
- Full Text
- View/download PDF
42. Feasibility Study of InAlN/GaN HEMT for sub-6 GHz Band Applications.
- Author
-
Kazutaka Inoue, Kenta Sugawara, Ken Kikuchi, Isao Makabe, and Hiroshi Yamamoto
- Published
- 2019
- Full Text
- View/download PDF
43. Analysis of Gate-Voltage Clipping Behavior on Class-F and Inverse Class-F Amplifiers.
- Author
-
Hiroshi Yamamoto, Ken Kikuchi, Norihiko Ui, Kazutaka Inoue, Valeria Vadalà, Gianni Bosi, Antonio Raffo, and Giorgio Vannini
- Published
- 2018
- Full Text
- View/download PDF
44. Association of Geriatric Nutritional Risk Index With Adverse Event and Treatment Duration in Adjuvant Chemotherapy for Patients With Colorectal Cancer.
- Author
-
ATSUYA SHIMIZU, MIYU FUKASAWA, RYOSUKE ENDO, TAKUMI NAKAMURA, SHOGO YAMADA, RYO FUJIBAYASHI, KEN KIKUCHI, MASAOMI TANAKA, ISAO HASEGAWA, and HIDEKI SATO
- Subjects
COLORECTAL cancer ,TREATMENT duration ,ADJUVANT chemotherapy ,ADVERSE health care events ,OXALIPLATIN - Abstract
Background/Aim: In recent years, the Geriatric Nutritional Risk Index (GNRI) has been reported as a predictor of prognosis in many patients with cancer. This study investigated the association of preoperative GNRI with the occurrence of adverse events and duration of treatment with capecitabine plus oxaliplatin (CAPOX), a postoperative adjuvant chemotherapy, in 59 patients with colorectal cancer from September 2019 to April 2022. Patients and Methods: A cut-off value of 100.9 was used to categorize patients into high and low GNRI groups. Results: The incidence of grade =2 leukopenia (p=0.03), and all grades peripheral neuropathy (p=0.04) were significantly more frequent in the low GNRI group. Analysis of factors influencing treatment duration by univariate and multivariate Cox regression proportional hazards models showed a significant difference in GNRI (p=0.0097). Conclusion: GNRI, a nutritional indicator assessed before the start of treatment, influences the occurrence of adverse events and duration of treatment with CAPOX as adjuvant chemotherapy. To complete CAPOX therapy, preoperatively, it is important to assess the patients' nutritional status using the GNRI and to actively intervene in nutritional therapy. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
45. Review of: 'Does the Time Dimension has to be Perpendicular to the Space-Dimensions?'
- Author
-
Ken Kikuchi
- Published
- 2023
- Full Text
- View/download PDF
46. Supplementary Figure 1. from The Novel Histone Deacetylase Inhibitor, OBP-801, Induces Apoptosis in Rhabdoid Tumors by Releasing the Silencing of NOXA
- Author
-
Hajime Hosoi, Toshiyuki Sakai, Yasumichi Kuwahara, Kunihiko Tsuchiya, Ken Kikuchi, Shigeki Yagyu, Mitsuru Miyachi, Hideki Yoshida, Kazutaka Ouchi, Chihiro Tomoyasu, Daisuke Kaneda, Tomoko Iehara, Yoshiki Katsumi, and Yohei Sugimoto
- Abstract
Supplementary Figure 1.
- Published
- 2023
- Full Text
- View/download PDF
47. Data from The Novel Histone Deacetylase Inhibitor, OBP-801, Induces Apoptosis in Rhabdoid Tumors by Releasing the Silencing of NOXA
- Author
-
Hajime Hosoi, Toshiyuki Sakai, Yasumichi Kuwahara, Kunihiko Tsuchiya, Ken Kikuchi, Shigeki Yagyu, Mitsuru Miyachi, Hideki Yoshida, Kazutaka Ouchi, Chihiro Tomoyasu, Daisuke Kaneda, Tomoko Iehara, Yoshiki Katsumi, and Yohei Sugimoto
- Abstract
Rhabdoid tumor is an aggressive, early childhood tumor. Biallelic inactivation of the SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily B member 1 (SMARCB1)/integrase interactor 1 (INI1) gene is the only common genetic feature in rhabdoid tumors. Loss of SMARCB1 function results in downregulation of several tumor suppressor genes including p16, p21, and NOXA. The novel histone deacetylase inhibitor, OBP-801, induces p21 and has shown efficacy against various cancers. In our study, OBP-801 strongly inhibited the cell growth of all rhabdoid tumor cell lines in WST-8 assay. However, Western blotting and cell-cycle analysis revealed that OBP-801 did not activate the P21-RB pathway in some cell lines. p21 knockout indicated that p21 did not dominate the OBP-801 antitumor effect in rhabdoid tumor cell lines. We discovered that OBP-801 induced NOXA expression and caspase-dependent apoptosis in rhabdoid tumor cell lines independent of TP53. Chromatin immunoprecipitation assay showed that OBP-801 acetylated histone proteins and recruited RNA polymerase II to the transcription start site (TSS) of the NOXA promotor. Moreover, OBP-801 recruited BRG1 and BAF155, which are members of the SWI/SNF complex, to the TSS of the NOXA promotor. These results suggest that OBP-801 epigenetically releases the silencing of NOXA and induces apoptosis in rhabdoid tumors. OBP-801 strongly inhibited tumor growth in human rhabdoid tumor xenograft mouse models in vivo. Terminal deoxynucleotidyl transferase–mediated dUTP nick end labeling and cleaved caspase-3 were stained in tumors treated with OBP-801. In conclusion, OBP-801 induces apoptosis in rhabdoid tumor cells by epigenetically releasing the silencing of NOXA, which is a key mediator of rhabdoid tumor apoptosis. The epigenetic approach for NOXA silencing with OBP-801 is promising for rhabdoid tumor treatment.
- Published
- 2023
- Full Text
- View/download PDF
48. Supplementary Figure 3. from The Novel Histone Deacetylase Inhibitor, OBP-801, Induces Apoptosis in Rhabdoid Tumors by Releasing the Silencing of NOXA
- Author
-
Hajime Hosoi, Toshiyuki Sakai, Yasumichi Kuwahara, Kunihiko Tsuchiya, Ken Kikuchi, Shigeki Yagyu, Mitsuru Miyachi, Hideki Yoshida, Kazutaka Ouchi, Chihiro Tomoyasu, Daisuke Kaneda, Tomoko Iehara, Yoshiki Katsumi, and Yohei Sugimoto
- Abstract
Supplementary Figure 3.
- Published
- 2023
- Full Text
- View/download PDF
49. Supplementary table from The Novel Histone Deacetylase Inhibitor, OBP-801, Induces Apoptosis in Rhabdoid Tumors by Releasing the Silencing of NOXA
- Author
-
Hajime Hosoi, Toshiyuki Sakai, Yasumichi Kuwahara, Kunihiko Tsuchiya, Ken Kikuchi, Shigeki Yagyu, Mitsuru Miyachi, Hideki Yoshida, Kazutaka Ouchi, Chihiro Tomoyasu, Daisuke Kaneda, Tomoko Iehara, Yoshiki Katsumi, and Yohei Sugimoto
- Abstract
Supplementary table
- Published
- 2023
- Full Text
- View/download PDF
50. Supplementary Figure 2. from The Novel Histone Deacetylase Inhibitor, OBP-801, Induces Apoptosis in Rhabdoid Tumors by Releasing the Silencing of NOXA
- Author
-
Hajime Hosoi, Toshiyuki Sakai, Yasumichi Kuwahara, Kunihiko Tsuchiya, Ken Kikuchi, Shigeki Yagyu, Mitsuru Miyachi, Hideki Yoshida, Kazutaka Ouchi, Chihiro Tomoyasu, Daisuke Kaneda, Tomoko Iehara, Yoshiki Katsumi, and Yohei Sugimoto
- Abstract
Supplementary Figure 2.
- Published
- 2023
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.