33 results on '"Daichi Murakami"'
Search Results
2. Peritonsillar abscess caused by hypervirulent Klebsiella pneumoniae: A case report and literature review
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Kazuya Mizobata, Daichi Murakami, Ryo Ueda, Yuki Suzuki, Yusuke Koizumi, Hisakazu Yano, Masamitsu Kono, and Muneki Hotomi
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Hypervirulent Klebsiella pneumoniae ,Peritonsillar abscess ,Infectious and parasitic diseases ,RC109-216 - Abstract
Klebsiella pneumoniae is a pathogenic bacterium responsible for otorhinolaryngology-head and neck infections. Hypervirulent K. pneumoniae (hvKp), an alarming subtype of K. pneumoniae, causes life-threatening hematogenous infection. However, there are few reports on the character of hvKp strain in the field of otorhinolaryngology-head and neck surgery. We report the case of a 60-year-old Japanese man with a peritonsillar abscess caused by hvKp. K. pneumoniae isolated from pus was positive in a string test. Genetic analysis revealed that the strain had K2, rmpA and aerobactin genes. There was no evidence of hematogenous infections such as bacteremia and liver abscess, and there was improvement by surgical drainage and intravenous antimicrobial treatment. To the best of our knowledge, this is the first reported case of peritonsillar abscess caused by hvKp that did not have hematogenous infections. The string test is a simple and inexpensive method for screening hvKp. This case highlights the need for strategies to inhibit the spread of these highly virulent strains by early drainage and appropriate antimicrobial treatment.
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- 2024
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3. Case Report: Solid variant of papillary thyroid carcinoma in a young adult with Turner syndrome with chronic thyroiditis
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Daichi Murakami, Masayoshi Hijiya, Takuro Iyo, Sachiko Hayata, Takashi Ozaki, Keisuke Enomoto, Masamitsu Kono, Shunji Tamagawa, and Muneki Hotomi
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solid variant of papillary thyroid carcinoma ,Turner syndrome ,chronic thyroiditis ,gene mutation ,gene panel test ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Turner syndrome is associated with an increased risk of developing several neoplasms. In particular, a clinical feature of Turner syndrome with chronic thyroiditis implies a relationship with thyroid malignancies. We report a very rare case of a solid variant of papillary thyroid carcinoma that was identified during a follow-up of chronic thyroiditis in a 22-year-old woman with Turner syndrome. The patient had no notable history of radiation exposure. No genetic mutations relating to the occurrence of the solid variant of papillary thyroid carcinoma, including RET/PTC rearrangements and mutations in the BRAF or RAS, were detected by a gene panel test, namely, the Oncomine™ Dx Target test. To the best of our knowledge, this is the first report of a solid variant of papillary thyroid carcinoma in a young adult with Turner syndrome with chronic thyroiditis. Our case suggests that in patients with Turner syndrome, there may be different pathogeneses from those previously reported, including exposure to radiation or known genetic mutations for the development of a solid variant of papillary thyroid carcinoma.
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- 2023
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4. Metallothionein synthesis increased by Ninjin-yoei-to, a Kampo medicine protects neuronal death and memory loss after exposure to amyloid β1-42
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Haruna Tamano, Haruna Tokoro, Daichi Murakami, Rin Tsujimoto, Yuka Nishijima, Erina Tsuda, Satoshi Watanabe, Miki Suzuki, and Atsushi Takeda
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Metallothionein ,Amyloid β1-42 ,Alzheimer’s disease ,Zn2+ dysregulation ,Ninjin-yoei-to ,Kampo medicine ,Therapeutics. Pharmacology ,RM1-950 ,Pharmacy and materia medica ,RS1-441 - Abstract
Abstract Background It is possible that increased synthesis of metallothioneins (MTs), Zn2+-binding proteins is linked with the protective effect of Ninjin-yoei-to (NYT) on Zn2+ toxicity ferried by amyloid β1-42 (Aβ1-42). Methods Judging from the biological half-life (18-20 h) of MTs, the effective period of newly synthesized MT on capturing Zn2+ is estimated to be approximately 2 days. In the present paper, a diet containing 3% NYT was administered to mice for 2 days and then Aβ1-42 was injected into the lateral ventricle of mice. Results MT level in the dentate granule cell layer was elevated 2 days after administration of NYT diet, while the administration reduced intracellular Zn2+ level increased 1 h after Aβ1-42 injection, resulting in rescuing neuronal death in the dentate granule cell layer, which was observed 14 days after Aβ1-42 injection. Furthermore, Pre-administration of NYT diet rescued object recognition memory loss via affected perforant pathway long-term potentiation after local injection of Aβ1-42 into the dentate granule cell layer of rats. Conclusion The present study indicates that pre-administration of NYT diet for 2 days increases synthesis of MTs, which reduces intracellular Zn2+ toxicity ferried by extracellular Aβ1-42, resulting in protecting neuronal death in the dentate gyrus and memory loss after exposure to Aβ1-42.
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- 2022
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5. Case report: Cochlear implantation was effective for progressive bilateral severe hearing loss associated with Kawasaki disease
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Daichi Murakami, Takahito Kimura, Masamitsu Kono, Akihiro Sakai, Tomohiro Suenaga, Masanobu Hiraoka, Hideki Sakatani, Makiko Ohtani, Hiroyuki Suzuki, Daisuke Tokuhara, and Muneki Hotomi
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Kawasaki disease ,hearing loss ,cochlear implantation ,speech development ,systemic vasculitis ,Pediatrics ,RJ1-570 - Abstract
Sensorineural hearing loss associated with Kawasaki disease has been increasingly reported, but its etiology remains unclear. Most reported cases of sensorineural hearing loss associated with Kawasaki disease have been mild and reversible during acute or subacute phases. However, bilateral severe hearing loss as a complication of Kawasaki disease can cause delays in cognitive and speech development. A 4-year-old Japanese boy treated for Kawasaki disease had right-side moderate and left-side profound sensorineural hearing loss on the 141st day after onset of Kawasaki disease. Despite systemic steroid pulse treatment, hearing loss remained in both sides. After the recurrence of Kawasaki disease, hearing on the right side progressively worsened, meaning there was now severe hearing loss on both sides. Left cochlear implantation performed on the 1065th day after the onset of Kawasaki disease improved the patient's hearing and his ability to communicate. Sensorineural hearing loss associated with Kawasaki disease may progress over a long period and cause bilateral severe hearing loss, although past reports showed occurrence during acute or subacute phases. The clinical course of our patient suggests that intense inflammation caused by Kawasaki disease could be related to prolonged hearing loss. Cochlear implantation seems to be effective for sensorineural hearing loss associated with Kawasaki disease.
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- 2023
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6. Maternal immunization with pneumococcal surface protein A provides the immune memories of offspring against pneumococcal infection
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Masamitsu Kono, Takuro Iyo, Daichi Murakami, Hideki Sakatani, Denisa Nanushaj, and Muneki Hotomi
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maternal immunization ,Streptococcus pneumoniae ,PspA ,immunological memory ,invasive infection ,Microbiology ,QR1-502 - Abstract
IntroductionStreptococcus pneumoniae (S. pneumoniae) is one of the most widespread pathogens in the world and one of the largest infectious causes of infant mortality. Although current vaccines have various benefits, antibiotic resistance and the inability to vaccinate infants less than one year old demands the development of new protective strategies. One strategy, ‘maternal immunization’, is to protect infants by passive immunity from an immunized mother, although its mechanism is still not fully understood.Materials and methodsThe current study aimed to acquire immunity against S. pneumoniae in infants by maternal immunization with pneumococcal common antigen, pneumococcal surface protein A (PspA). Four-week-old female mice were immunized with recombinant PspA intranasally twice a week for three weeks. Females were mated with age-matched males after immunization, and delivered offspring.ResultsThe week-old offspring derived from and fostered by immunized mothers had more anti-PspA-specific antibody producing cells in the spleen than those derived from sham-immunized mothers. The offspring were raised up to four weeks old and were subcutaneously stimulated with recombinant PspA. The levels of anti-PspA IgG in sera after stimulation were significantly higher in the offspring derived from the immunized mothers and the induced specific antibody to PspA showed protective efficacy against systemic pneumococcal infection.DiscussionMaternal immunization is suggested to be able to provide a sustained immune memory to offspring. The current study would be a milestone in the field of maternal immunization toward a universal pneumococcal vaccine.
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- 2023
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7. Adult onset Kawasaki disease presenting with acute epiglottitis findings
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Daichi Murakami, Gen Sugita, Mehmet Gunduz, Tomohiro Suenaga, Takashi Takeuchi, Hiroyuki Suzuki, and Muneki Hotomi
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Otorhinolaryngology ,RF1-547 - Published
- 2020
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8. The Role of Anatomical Imaging and Intraoperative Neuromonitoring (IONM) for Successful Prediction of a Nonrecurrent Laryngeal Nerve
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Hiroki Kuwazoe, Keisuke Enomoto, Daichi Murakami, Naoko Kumashiro, Saori Takeda, and Muneki Hotomi
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Surgery ,RD1-811 - Abstract
A nonrecurrent laryngeal nerve (NRLN) is a rare anatomical variant of laryngeal nerves that branches directly from the vagus nerve. The anatomical abnormality makes it difficult to identify the NRLN and results in high incidence of accidental nerve injury during surgery. A 76-year-old woman complained of swelling in the right side of her neck and visited our university hospital for further examination. Ultrasonography showed a right thyroid lobe mass with calcification and fine needle aspiration biopsy was classified as class III. Computed tomography revealed that the right subclavian artery branched directly from the descending aorta without branching from the brachiocephalic artery and ran behind the esophagus. Since it was afraid that the accidental injury of NRLN was likely to occur, a right thyroid lobe dissection using intraoperative neuromonitoring (IONM) was performed. After separating the connective tissue on the thyroid capsule from the right side of the trachea to the inferior pole laterally, the NRLN running across the level of the inferior margin of the cricoid cartilage was identified by using IONM 0.5 mA stimulation. After complete dissection of right thyroid lobe, we again stimulated the NRLN by 0.5 mA and the electromyographic response was confirmed. The pathological analysis confirmed nodular hyperplasia without malignancy; the condition was diagnosed as an adenomatous goiter. There was no vocal cord dysfunction and hoarseness after the surgery. IONM contributed to the prevention of NRLN injury during the surgery. We believe that it is important to confirm the presence or absence of an aberrant subclavian artery on preoperative imaging, and that IONM should be considered to identify the NRLN to prevent vocal cord paralysis if its presence is suspected.
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- 2022
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9. Improvement of Surgical View and Working Space at the Lower Pole by Three-Dimensional Exoscope-Assisted Coblation Tonsillectomy: A Case Series
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Daichi Murakami, Masayoshi Hijiya, Takuro Iyo, Gen Sugita, Sachiko Hayata, Masamitsu Kono, and Muneki Hotomi
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exoscope ,coblation ,tonsillectomy ,Medicine (General) ,R5-920 - Abstract
Advantages of hot devices for tonsillectomy, represented by coblation, have been highlighted in recent years. During hot technique tonsillectomy it is important to identify and coagulate the vessels of the tonsillar capsule, especially at the lower pole of the tonsil. Hot technique tonsillectomy under microscope or endoscope has therefore been recommended to achieve accurate identification of the microstructure of the surgical field. We have applied ORBEYE, a three-dimensional surgical exoscope system, to coblation tonsillectomy. Advantages of using ORBEYE include high definition and high magnification images, and flexibility of camera position and angle. This means there is an improved surgical view and working space, particularly at the lower pole during performance of coblation tonsillectomy. Here, we demonstrate that ORBEYE can be an effective surgical instrument in coblation tonsillectomy.
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- 2023
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10. The Roles of Transient Receptor Potential Vanilloid 1 and 4 in Pneumococcal Nasal Colonization and Subsequent Development of Invasive Disease
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Masamitsu Kono, Denisa Nanushaj, Hideki Sakatani, Daichi Murakami, Masayoshi Hijiya, Tetsuya Kinoshita, Tatsuya Shiga, Fumie Kaneko, Keisuke Enomoto, Gen Sugita, Masayasu Miyajima, Yuka Okada, Shizuya Saika, and Muneki Hotomi
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transient receptor potential (TRP) ,Streptococcus pneumoniae (pneumococcus) ,nasal colonization ,pneumonia ,sepsis ,mouse model ,Immunologic diseases. Allergy ,RC581-607 - Abstract
Transient receptor potential (TRP) channels, neuronal stimulations widely known to be associated with thermal responses, pain induction, and osmoregulation, have been shown in recent studies to have underlying mechanisms associated with inflammatory responses. The role of TRP channels on inflammatory milieu during bacterial infections has been widely demonstrated. It may vary among types of channels/pathogens, however, and it is not known how TRP channels function during pneumococcal infections. Streptococcus pneumoniae can cause severe infections such as pneumonia, bacteremia, and meningitis, with systemic inflammatory responses. This study examines the role of TRP channels (TRPV1 and TRPV4) for pneumococcal nasal colonization and subsequent development of invasive pneumococcal disease in a mouse model. Both TRPV1 and TRPV4 channels were shown to be related to regulation of the development of pneumococcal diseases. In particular, the influx of neutrophils (polymorphonuclear cells) in the nasal cavity and the bactericidal activity were significantly suppressed among TRPV4 knockout mice. This may lead to severe pneumococcal pneumonia, resulting in dissemination of the bacteria to various organs and causing high mortality during influenza virus coinfection. Regulating host immune responses by TRP channels could be a novel strategy against pathogenic microorganisms causing strong local/systemic inflammation.
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- 2021
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11. Novel Antimicrobial Treatment Strategy Based on Drug Delivery Systems for Acute Otitis Media
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Masamitsu Kono, Nafisa K. Umar, Saori Takeda, Makiko Ohtani, Daichi Murakami, Hideki Sakatani, Fumie Kaneko, Denisa Nanushaj, and Muneki Hotomi
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acute otitis media ,drug delivery system ,PK/PD ,sustained release ,antibiotics ,Therapeutics. Pharmacology ,RM1-950 - Abstract
Despite tremendous success of pneumococcal conjugated vaccine and antimicrobial treatment by amoxicillin, acute otitis media (AOM) still remains as a great medical concern. Failure of antimicrobial treatment includes several factors. The middle ear cavity is surrounded by bone tissue, which makes it difficult to maintain sufficient concentration of antibiotics. Tympanic membrane of AOM patients thickens and actually becomes a barrier for topical therapy. This review discusses novel antimicrobial treatment strategies based on drug delivery systems (DDS) for AOM. To deliver drugs enough to kill the pathogenic bacteria without systemic side effects, the development of new antimicrobial treatment strategy applying innovative drug DDS has been expected. The sustained-release DDS can achieve sufficient time for antimicrobial concentrations to exceed minimum inhibitory concentration (MIC) for time-dependent antibiotics as well as enough maximum concentration for dose-dependent antibiotics to eradicate causative pathogens in the middle ear. The development of trans-tympanic membranes of DDS, such as hydrogels with chemical permeation enhancers (CPEs), is another attractive strategy. Phage is a promising strategy for developing DDS-based therapies. The DDS formulations enable antimicrobial treatment of AOM by a single dose and thus, an attractive future antimicrobial treatment for AOM.
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- 2021
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12. Exposure to Cigarette Smoke Enhances Pneumococcal Transmission Among Littermates in an Infant Mouse Model
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Daichi Murakami, Masamitsu Kono, Denisa Nanushaj, Fumie Kaneko, Tonia Zangari, Yasuteru Muragaki, Jeffrey N. Weiser, and Muneki Hotomi
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Streptococcus pneumoniae ,transmission ,cigarette smoke ,children ,mouse model ,Microbiology ,QR1-502 - Abstract
Streptococcus pneumoniae, one of the most common commensal pathogens among children, is spread by close contact in daycare centers or within a family. Host innate immune responses and bacterial virulence factors promote pneumococcal transmission. However, investigations into the effects of environmental factors on transmission have been limited. Passive smoking, a great concern for children’s health, has been reported to exacerbate pneumococcal diseases. Here, we describe the effect of cigarette smoke exposure on an infant mouse model of pneumococcal transmission. Our findings reveal that the effect of cigarette smoke exposure significantly promotes pneumococcal transmission by enhancing bacterial shedding from the colonized host and by increasing susceptibility to pneumococcal colonization in the new host, both of which are critical steps of transmission. Local inflammation, followed by mucosal changes (such as mucus hypersecretion and disruption of the mucosal barrier), are important underlying mechanisms for promotion of transmission by smoke exposure. These effects were attributable to the constituents of cigarette smoke rather than smoke itself. These findings provide the first experimental evidence of the impact of environmental factors on pneumococcal transmission and the mechanism of pathogenesis.
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- 2021
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13. Respiratory quinolones can eradicate amoxicillin-induced mature biofilms and nontypeable Haemophilus influenzae in biofilms
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Nafisa Khamis Umar, Masamitsu Kono, Hideki Sakatani, Daichi Murakami, Yoshimi Onishi, Tomoko Kamiyama, Takuro Iyo, Masayoshi Hijiya, Tatsuya Shiga, Tetsuya Kinoshita, Shunji Tamagawa, Masanobu Hiraoka, Makiko Ohtani, and Muneki Hotomi
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Microbiology (medical) ,Haemophilus Infections ,Infectious Diseases ,Anti-Infective Agents ,Biofilms ,Amoxicillin ,Humans ,Pharmacology (medical) ,Quinolones ,Haemophilus influenzae ,Anti-Bacterial Agents - Abstract
Biofilm is thought to be involved in the persistent bacterial infections caused by nontypeable Haemophilus influenzae (NTHi). This study aims to evaluate the efficacy of antibiotics against NTHi biofilms.A 96-wells pin replicator assay was applied for evaluation of antimicrobial efficacies against NTHi biofilms. The NTHi IH-202 strain for the standard and 10 clinical strains were evaluated, as well as the viability of NTHi in biofilms after antimicrobial exposures.Biofilms formed by IH-202 strain accumulated during incubation. AMPC if not high concentrations, neither reduce or inhibit biofilm formation, nor eradicate matured NTHi biofilms. The NTHi in matured biofilm were alive after exposure to amoxicillin (AMPC). Even high concentration of AMPC produced live NTHi after suspension of exposure, while tosufloxacin and garenoxacin inhibited biofilm formation of NTHi and eradicated matured biofilms. The respiratory quinolones, but not AMPC, killed NTHi in biofilms even at sub-MIC.NTHi persists in biofilms, even after exposure to AMPC. These findings may eventually lead to a better understanding of effective use of antibiotics to eradicate NTHi growing as biofilms, or even to the development of novel therapeutic agents for treating patients with mucosal NTHi biofilm infections. Meanwhile, respiratory quinolones are attractive agents in reducing NTHi biofilm formation and destroying established biofilm.
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- 2022
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14. Investigation on the virulence of non-encapsulated Streptococcus pneumoniae using liquid agar pneumonia model
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Hideki Sakatani, Masamitsu Kono, Gen Sugita, Denisa Nanushaj, Masayoshi Hijiya, Takuro Iyo, Tatsuya Shiga, Daichi Murakami, Norihito Kaku, Katsunori Yanagihara, Moon H. Nahm, and Muneki Hotomi
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Microbiology (medical) ,Agar ,Mice ,Streptococcus pneumoniae ,Infectious Diseases ,Virulence ,Animals ,Cytokines ,Bacteremia ,Pharmacology (medical) ,Pneumonia, Pneumococcal ,Pneumococcal Infections - Abstract
Since the introduction of pneumococcal conjugate vaccine, there have been warnings of an increase in infections caused by non-vaccine type of Streptococcus pneumoniae strains. Among them, nonencapsulated Streptococcus pneumoniae (NESp) has been reported to cause invasive infections, especially in children and the elderly. Due to low virulence, however, basic experimental reports on invasive infections are limited.We applied a liquid-agar method to establish a mouse model of invasive NESp infection. Mice were intratracheally administered a bacterial suspension including agar. With this technique, we investigated the pathogenicity of NESp and the effect of Pneumococcal surface protein K (PspK), a specific surface protein antigen of NESp. NESp wild-type strain (MNZ11) and NESp pspK-deleted mutant strain (MNZ1131) were used in this study. The survival rate, number of bacteria, cytokine/chemokine levels in the bronchoalveolar lavage fluid, and histology of the lung tissue were evaluated.Mice that were intratracheally administered MNZ11 developed lethal pneumonia with bacteremia within 48 h. Conversely, MNZ1131 showed predominantly low lethality without significant pro-inflammatory cytokine production. NESp was found to cause severe pneumonia and bacteremia upon reaching the lower respiratory tract, and PspK was a critical factor of NESp for developing invasive infections.The current study demonstrated the ability of NESp to develop invasive diseases, especially in connection with PspK by use of a mouse pneumonia model.
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- 2022
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15. Nucleic acid sensing Toll-like receptors 3 and 9 play complementary roles in the development of bacteremia after nasal colonization associated with influenza co-infection.
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Denisa NANUSHAJ, Masamitsu KONO, Hideki SAKATANI, Daichi MURAKAMI, and Muneki HOTOMI
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- 2024
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16. Impact of the practical guideline on appropriate usage of antimicrobial treatments for surgical site infections in reconstructive surgery of head and neck cancer
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Shunji Tamagawa, Takuro Iyo, Masamitsu Kono, Gen Sugita, Saori Takeda, Naoko Kumashiro, Daichi Murakami, Keisuke Enomoto, Makiko Ohtani, and Muneki Hotomi
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Microbiology (medical) ,Infectious Diseases ,Head and Neck Neoplasms ,Humans ,Surgical Wound Infection ,Pharmacology (medical) ,Antibiotic Prophylaxis ,Plastic Surgery Procedures ,Free Tissue Flaps ,Anti-Bacterial Agents ,Retrospective Studies - Abstract
In 2016, Japanese Society of Chemotherapy and Japan Society for Surgical Infection presented the practical guideline for appropriate usage of antimicrobial agents to prevent postoperative infections. This study aims to exhibit the validity of the guideline as a series of effective strategies for prevention of surgical site infections (SSIs) during reconstructive surgery of the head and neck cancer.We retrospectively evaluated patients who underwent head and neck reconstructive surgery with free or pedicle flaps in a single institute in Japan between July 2010 and July 2020. We evaluated the incidence of SSIs, patient backgrounds, and microbiological characteristics on the basis of antimicrobial prophylaxis recommended by the guideline.Enrolled in this study were 102 patients in our institution who underwent head and neck reconstructive surgery with free or pedicle flaps between July 2010 and July 2020. In the period between January 2018 to July 2020 after the SSI guideline was advocated (SSI guideline period), the ratio of administration of sulbactam/ampicillin (SBT/ABPC) was significantly higher (P 0.001) and the duration of prophylactic antimicrobial treatment was significantly shorter than in the period between July 2010 to December 2017 before the SSI guideline was advocated (Pre-SSI guideline period) (P 0.001). Incidence of SSIs were similar, even when antibiotic use was changed to be short-term single-agent administration in accordance with the practical guideline.Adherence to the current Japanese practical guideline on appropriate antimicrobial prophylaxis for SSIs can shorten the duration of usage of antimicrobial treatment without increasing the risk for occurrence of SSIs.
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- 2022
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17. A Novel Pneumococcal Surface Protein K of Nonencapsulated Streptococcus pneumoniae Promotes Transmission among Littermates in an Infant Mouse Model with Influenza A Virus Coinfection
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Hideki Sakatani, Masamitsu Kono, Denisa Nanushaj, Daichi Murakami, Saori Takeda, Fumie Kaneko, Moon H. Nahm, and Muneki Hotomi
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Host Response and Inflammation ,Coinfection ,Virulence Factors ,Immunology ,Microbiology ,Pneumococcal Infections ,Pneumococcal Vaccines ,Disease Models, Animal ,Mice ,Infectious Diseases ,Streptococcus pneumoniae ,Influenza A virus ,Animals ,Humans ,Parasitology ,Darbepoetin alfa ,Aged - Abstract
We established an infant mouse model for colonization and transmission by nonencapsulated Streptococcus pneumoniae (NESp) strains to gain important information about its virulence among children. Invasive pneumococcal diseases have decreased dramatically since the worldwide introduction of pneumococcal capsular polysaccharide vaccines. Increasing prevalence of nonvaccine serotypes, including NESp, has been highlighted as a challenge in treatment strategy, but the virulence of NESp is not well understood. Protective strategies against NESp colonization and transmission between children require particularly urgent evaluation. NESp lacks capsules, a major virulence factor of pneumococci, but can cause a variety of infections in children and older people. PspK, a specific surface protein of NESp, is a key factor in establishing nasal colonization. In our infant mouse model for colonization and transmission by NESp strains, NESp could establish stable nasal colonization at the same level as encapsulated serotype 6A in infant mice and could be transmitted between littermates. Transmission was promoted by NESp surface virulence factor PspK and influenza virus coinfection. However, PspK deletion mutants lost the ability to colonize and transmit to new hosts. Promotion of NESp transmission by influenza was due to increased susceptibility of the new hosts. PspK was a key factor not only in establishment of nasal colonization but also in transmission to new hosts. PspK may be targeted as a new candidate vaccine for NESp infection in children.
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- 2022
18. An Optimization of Resource Arrangement for Network-on-Chip using Genetic Algorithm.
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Daichi Murakami and Kei Hiraki
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- 2015
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19.
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Chairperson: Shigeharu, Fujieda, primary, Tsuguhisa, Nakayama, additional, Presenter: Shigeharu, Fujieda, additional, Luo, Zhang, additional, Baharudin, Abdullah, additional, Yi-Tsen, Lin, additional, and Daichi, Murakami, additional
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- 2021
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20. Parametric Studies on Aerodynamic Performance of Various Types of LP Turbine Airfoils for Aero-Engines Under the Influence Periodic Wakes and Freestream Turbulence
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Yasuhiro Okamura, Daichi Murakami, and Ken-ichi Funazaki
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Physics ,Airfoil ,business.industry ,Turbulence ,Reynolds number ,Inflow ,Aerodynamics ,Turbine ,symbols.namesake ,symbols ,Aerospace engineering ,business ,Freestream ,Parametric statistics - Abstract
This study carries out parametric investigations on aerodynamic loss of various types of LP turbine airfoils characterized with different flow deceleration rates (DR) on their suction surfaces under the realistic flow conditions such as wake inflow and freestream turbulence. The Reynolds number examined in this study ranges from 57,000 to 170,000. As for the freestream turbulence, two levels of the turbulence are used, i.e., about 1.2% and 3.5%. Stagnation pressure distributions downstream of each of the airfoil cascades are measured by use of a Pitot tube, while steady-state and unsteady boundary-layers are measured over the rear part of suction surface and pressure side near the trailing edge using a single hot-wire probe. The measured boundary-layer data are used to estimate the cascade loss along with RANS (Reynolds-Averaged Navier-Stokes) simulations by taking advantage of the momentum-theory based Denton’s method. First, relationships between the cascade loss for each flow condition and DR are examined. The estimated loss values are then compared with the measured cascade loss to check the validity of the loss estimation method, which is a derivative of Denton’s method, under the realistic flow conditions.
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- 2019
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21. Recurrent bacterial translocation from gut and sepsis in Head and neck cancer patients and its prevention by probiotics
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Shunji Tamagawa, Mehmet Gunduz, Muneki Hotomi, Masanobu Hiraoka, Daichi Murakami, Ihsan Gunduz, and Gen Sugita
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0301 basic medicine ,Male ,medicine.medical_specialty ,medicine.medical_treatment ,Chromosomal translocation ,Antineoplastic Agents ,Bacterial translocation ,Gastroenterology ,law.invention ,Sepsis ,03 medical and health sciences ,Probiotic ,0302 clinical medicine ,law ,Internal medicine ,medicine ,Humans ,Intestinal Mucosa ,Laryngeal Neoplasms ,Chemotherapy ,business.industry ,Probiotics ,Head and neck cancer ,Hypopharyngeal cancer ,General Medicine ,Middle Aged ,medicine.disease ,Intestines ,Lactobacillus ,030104 developmental biology ,Head and Neck Neoplasms ,030220 oncology & carcinogenesis ,Bacterial Translocation ,Carcinoma, Squamous Cell ,Bifidobacterium ,business ,Chemoradiotherapy - Abstract
Head and neck cancers are the 6th most common cancer type in human malignant tumors and treated with chemoradiotherapy and surgery. Chemotherapy during these treatment modalities leads to damage of intestinal epithelial barriers and results in translocation of intestinal bacteria in bloodstream through invasion in these damaged regions. In this report, we report two cases of hypopharyngeal cancer patients, both of whom received chemotherapy before surgery. The patients demonstrated repeated sepsis before and after surgery, supporting translocation of intestinal bacteria. Proper continuous probiotic use prevented proliferation and intestinal bacterial translocation. Hypothesis of bacterial translocation and prevention by probiotics are discussed.
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- 2018
22. Intelligent Cell Search Engine
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Atsuhiro Nakagawa, Yoshitaka Shirasaki, Kotaro Hiramatsu, Yasuhiro Fujiwaki, Yusuke Kasai, Hideya Fukuzawa, Hiroshi Karakawa, Taichiro Endo, Daichi Murakami, Yusuke Oguchi, Ming Li, Takanori Maeno, Dino Di Carlo, Kiyotaka Shiba, Satoshi Matsusaka, Yu Hoshino, Nao Nitta, Fumihito Arai, Sangwook Lee, Chihana Toyokawa, Yaxiaer Yalikun, Kenichi Koizumi, Akihiro Isozaki, Hideharu Mikami, Takuro Ito, Hiroshi Tezuka, Yuta Suzuki, Shinya Sakuma, Takanori Iino, Keisuke Goda, Takeaki Sugimura, Hirofumi Shintaku, Mary Inaba, Sotaro Uemura, Kei Hiraki, Cheng Lei, Tadataka Ota, Masayuki Yazawa, Yo Tanaka, Minoru Oikawa, Misa Hase, Takashi Yamano, Yoichiroh Hosokawa, Makoto Yamada, Yasuyuki Ozeki, Mai Yamagishi, Nobutake Suzuki, Yutaka Yatomi, Kanako Suga, Takeshi Hayakawa, and Atsushi Yasumoto
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Cell search ,Data processing ,Data acquisition ,Intracellular protein ,business.industry ,Data management ,Distributed computing ,Scientific discovery ,Sorting ,Cell sorting ,business - Abstract
A fundamental challenge of biology is to understand the vast heterogeneity of cells, particularly how cellular composition, structure, and morphology are linked to cellular physiology. Unfortunately, conventional technologies are limited in uncovering these relations. We present a real-time machine intelligence technology based on a radically new architecture that realizes real-time image-based intelligent cell search and sorting at an unprecedented rate. The technology integrates high-throughput cell imaging, cell focusing, and cell sorting on a hybrid software-hardware data management infrastructure, enabling real-time automated operation for data acquisition, data processing, decision making, and actuation. Specifically, we use it to demonstrate real-time sorting of microalgal and blood cells based on intracellular protein localization and cell-cell interaction from large heterogeneous populations for studying photosynthesis and atherothrombosis, respectively. Our technology is highly versatile and expected to enable machine-based scientific discovery in biological, pharmaceutical, and medical sciences.
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- 2018
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23. B027 Clarification of relationship between fiber orientation and tool wear in milling of CFRP
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Takeshi Yashiro, Hiroyuki Sasahara, and Daichi Murakami
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Materials science ,Fiber orientation ,Mechanical engineering ,General Medicine ,Tool wear ,Manufacturing engineering - Published
- 2013
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24. 125 Parametric Studies of Aerodynamic Performance on LP Turbine Airfoil for Aero Engines
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Juo Furukawa, Daichi Murakami, and Ken-ichi Funazaki
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Airfoil ,Boundary layer ,Materials science ,Aerodynamics ,Mechanics ,Turbine ,Parametric statistics - Published
- 2018
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25. Intelligent Image-Activated Cell Sorting
- Author
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Sotaro Uemura, Yasuhiro Fujiwaki, Yasuyuki Ozeki, Taichiro Endo, Kiyotaka Shiba, Yaxiaer Yalikun, Ming Li, Takanori Maeno, Fumihito Arai, Cheng Lei, Satoshi Matsusaka, Mary Inaba, Hiroshi Tezuka, Yoichiroh Hosokawa, Atsushi Yasumoto, Kotaro Hiramatsu, Takanori Iino, Kei Hiraki, Keisuke Goda, Takashi Yamano, Akihiro Isozaki, Hideya Fukuzawa, Sangwook Lee, Chihana Toyokawa, Takeshi Hayakawa, Makoto Yamada, Atsuhiro Nakagawa, Hideharu Mikami, Daichi Murakami, Yuta Suzuki, Yusuke Oguchi, Yoshitaka Shirasaki, Shinya Sakuma, Yutaka Yatomi, Kanako Suga, Takuro Ito, Masayuki Yazawa, Mai Yamagishi, Nobutake Suzuki, Misa Hase, Dino Di Carlo, Yusuke Kasai, Kenichi Koizumi, Hiroshi Karakawa, Yu Hoshino, Nao Nitta, Tadataka Ota, Yo Tanaka, Takeaki Sugimura, Hirofumi Shintaku, and Minoru Oikawa
- Subjects
0301 basic medicine ,cellular morphology ,Distributed computing ,Scientific discovery ,convolutional neural network ,Image processing ,02 engineering and technology ,Biology ,machine intelligence ,Convolutional neural network ,high-throughput screening ,General Biochemistry, Genetics and Molecular Biology ,Image (mathematics) ,ghigh-throughput microscopy ,03 medical and health sciences ,Data acquisition ,cellular heterogeneity ,Image Processing, Computer-Assisted ,Animals ,Humans ,Intracellular protein ,Sorting ,deep learning ,image-activated cell sortin ,Cell sorting ,021001 nanoscience & nanotechnology ,Flow Cytometry ,High-Throughput Screening Assays ,030104 developmental biology ,0210 nano-technology - Abstract
A fundamental challenge of biology is to understand the vast heterogeneity of cells, particularly how cellular composition, structure, and morphology are linked to cellular physiology. Unfortunately, conventional technologies are limited in uncovering these relations. We present a machine-intelligence technology based on a radically different architecture that realizes real-time image-based intelligent cell sorting at an unprecedented rate. This technology, which we refer to as intelligent image-activated cell sorting, integrates high-throughput cell microscopy, focusing, and sorting on a hybrid software-hardware data-management infrastructure, enabling real-time automated operation for data acquisition, data processing, decision-making, and actuation. We use it to demonstrate real-time sorting of microalgal and blood cells based on intracellular protein localization and cell-cell interaction from large heterogeneous populations for studying photosynthesis and atherothrombosis, respectively. The technology is highly versatile and expected to enable machine-based scientific discovery in biological, pharmaceutical, and medical sciences., 世界初のIntelligent Image-Activated Cell Sorterを開発 --細胞画像の深層学習により高速細胞選抜を実現--. 京都大学プレスリリース. 2018-09-05.
- Published
- 2018
26. An Optimization of Resource Arrangement for Network-on-Chip using Genetic Algorithm
- Author
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Kei Hiraki and Daichi Murakami
- Subjects
Network on a chip ,Resource (project management) ,Computer science ,Distributed computing ,Uniform design ,Genetic algorithm ,Routing (electronic design automation) - Abstract
Non-uniform arrangement of on-chip resources could outperform the uniform design. The way of arrangement itself, however, has not been well researched yet. In this research, we proposed an automatic method for better arrangement of the on-chip resources using GA.
- Published
- 2015
- Full Text
- View/download PDF
27. Verification of LLC resonant converter applied a current-balancing high-frequency transformer with multi-output windings
- Author
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Hirohito Funato, Ikki Shinozaki, Teruyoshi Mihara, Daichi Murakami, Yukitsugu Hirota, Jun Araki, Satoshi Ogasawara, Masayuki Mouri, and Fumihiro Okazaki
- Subjects
Forward converter ,Engineering ,business.industry ,Flyback converter ,Buck–boost converter ,Ćuk converter ,Electrical engineering ,law.invention ,law ,Boost converter ,Electronic engineering ,Skin effect ,business ,Transformer ,Negative impedance converter - Abstract
DC-DC converters of hybrid vehicles and electric vehicles are required to become smaller and lighter for building roomy and light weight EV. High-frequency switching can be used to miniaturize DC-DC converter. However, the influence of the skin effect and the eddy current become large. Parallel operation of converter is often for current applications using multiple winding transformers in order to reduce of skin effect. However, it is difficult to equalize the each current of converter due to unbalance of winding resistance, drop voltage of diodes and so on. In this paper, the parallel LLC converter applied a current-balancing high-frequency transformer is proposed. The proposed converter can realize nearly equal current even if the stray impedance of secondary circuit of LLC are unbalanced.
- Published
- 2014
- Full Text
- View/download PDF
28. 189 Studies on high-lift low pressure turbine airfoil using turbulent devices
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Daichi Murakami, Teruyuki Shiota, Hiroki Kaneda, Ken-ichi Funazaki, and Ryota Sato
- Subjects
Airfoil ,Materials science ,Turbulence ,Turbine ,High lift ,Marine engineering - Published
- 2016
- Full Text
- View/download PDF
29. Vibration characteristics of CFRTP with curvilinear reinforcing fibers
- Author
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Wataru Miyaiima, Daichi Murakami, and Shinya Honda
- Subjects
Vibration ,Curvilinear coordinates ,Materials science ,Composite material - Published
- 2017
- Full Text
- View/download PDF
30. Endwall Secondary Flow Control in Low Pressure Turbine
- Author
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Juo Furukawa, Ken-ichi Funazaki, Daichi Murakami, Teruyuki Shiota, and Ryota Sato
- Published
- 2017
- Full Text
- View/download PDF
31. Impact Damper Using collision of Beam Type Vibrator
- Author
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DAICHI, Murakami, primary, IWATA, Yoshio, additional, KOMATSUZAKI, Toshihiko, additional, and ASANUMA, Haruhiko, additional
- Published
- 2016
- Full Text
- View/download PDF
32. B07 Clarification of relationship between fiber orientation and tool wear in milling of CFRP
- Author
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Takeshi Yashiro, Hiroyuki Sasahara, and Daichi Murakami
- Subjects
Materials science ,Fiber orientation ,Mechanical engineering ,Tool wear ,Manufacturing engineering - Published
- 2012
- Full Text
- View/download PDF
33. J0520204 Studies on High-Lift LP Turbine Airfoil using Turbulent Devices
- Author
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Hiroki Kaneda, Daichi Murakami, Ryota Sato, Ken-ichi Funazaki, and Teruyuki Shiota
- Subjects
Airfoil ,Materials science ,Turbulence ,Turbine ,High lift ,Marine engineering - Published
- 2015
- Full Text
- View/download PDF
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