Takeshi Tanaka

Dr. Takeshi Tanaka

orcid

Research Focus & Metrics

Academic Career Length

21Years (2006-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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8 July 2021 in Scientific Reports
Verified
Journal Article
Open access
PDF file
TTTakeshi Tanaka
Takeshi Tanaka
MMMasahiko Mori
Masahiko Mori
MSMotohiro Sekino
Motohiro Sekino
UHUshio Higashijima
Ushio Higashijima
MTMasahiro Takaki
Masahiro Takaki
KIKoichi Izumikawa
Koichi Izumikawa
Septic shock is characterized by dysregulated vascular permeability. We hypothesized that the vascular permeability of endothelial cells (ECs) would be regulated by serotonin via serotonin-Rho-associated kinase (ROCK) signaling. We aimed to determine the impact of 5-hydroxyindoleacetic acid (5-HIAA) on septic shock as a novel biomarker. Plasma 5-HIAA levels and disease severity indices were obtained from 47 patients with sepsis. The association between 5-HIAA levels and severity indices was analyzed. Permeability upon serotonin stimulation was determined using human pulmonary microvascular ECs. 5-HIAA were significantly higher in septic shock patients than in patients without shock or healthy controls (p = 0.004). These elevated levels were correlated with severity indexes (SOFA score [p < 0.001], APACHE II [p < 0.001], and PaO2:FiO2 [p = 0.02]), and longitudinally associated with worse clinical outcomes (mechanical ventilation duration [p = 0.009] and ICU duration [p = 0.01]). In the experiment, serotonin increased the permeability of ECs, which was inhibited by the ROCK inhibitor (p < 0.001). Serotonin increases vascular permeability of ECs via ROCK signaling. This suggests a novel mechanism by which serotonin disrupts endothelial barriers via ROCK signaling and causes the pathogenesis of septic shock with a vascular leak. Serotonin serves as a novel biomarker of vascular permeability.

25 January 2025 in Journal of Fungi
Verified
Journal Article
Open access
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MTMasato Tashiro
Masato Tashiro
YNYuichiro Nakano
Yuichiro Nakano
TSTomoyuki Shirahige
Tomoyuki Shirahige
SKSatoshi Kakiuchi
Satoshi Kakiuchi
AFAyumi Fujita
Ayumi Fujita
KIKoichi Izumikawa
Koichi Izumikawa
As azole-resistant Aspergillus fumigatus emerges globally, healthcare facilities face mounting challenges in managing invasive aspergillosis. This review synthesizes worldwide azole resistance data to reveal profound regional variability, demonstrating that findings from other regions cannot be directly extrapolated to local settings. Consequently, hospital-level environmental surveillance is crucial for tailoring interventions to local epidemiology and detecting resistant strains in real-time. We outline practical approaches—encompassing sampling site prioritization, diagnostic workflows (culture-based and molecular), and PDCA-driven continuous improvement—so that even resource-limited facilities can manage resistant isolates more effectively. By linking real-time surveillance findings with clinical decisions, hospitals can tailor antifungal stewardship programs and swiftly adjust prophylaxis or treatment regimens. Our approach aims to enable accurate, ongoing evaluations of emerging resistance patterns, ensuring that institutions maintain efficient and adaptive programs. Ultimately, we advocate for sustained, collaborative efforts worldwide, where facilities adapt protocols to local conditions, share data through international networks, and contribute to a global knowledge base on resistance mechanisms. Through consistent application of these recommendations, healthcare systems can better preserve azole efficacy, safeguard immunocompromised populations, and refine infection control practices in the face of evolving challenges.

1 November 2006 in Infection Control & Hospital Epidemiology
Verified
Journal Article
Closed access
PDF file
KNKazutoshi Nakashima
Kazutoshi Nakashima
TTTakeshi Tanaka
Takeshi Tanaka
MKMichael H. Kramer
Michael H. Kramer
HTHiroshi Takahashi
Hiroshi Takahashi
TOTakaaki Ohyama
Takaaki Ohyama
NONobuhiko Okabe
Nobuhiko Okabe
Objective.: To identify risk factors for infection and severe illness due to Chlamydia pneumoniae.Methods.: To identify risk factors for infection, we conducted a case-control study among nursing home residents who had onset of symptoms during December 1, 1999, to February 20, 2000. To identify risk factors for severe illness among nursing home residents, we conducted a retrospective cohort study.Setting.: A nursing home providing long-term and day care services for elderly patients in Japan.Participants.: Fifty-nine residents and 41 staff members of a nursing home.Results.: The attack rates for respiratory illness were 53% (31 of 59) among residents and 22% (9 of 41) among staff. Infection was confirmed in 15 resident and 2 staff case patients by isolation of C. pneumoniae from nasal swab specimens. Fifteen resident case patients developed severe illness (ie, bronchitis, pneumonia, and hypoxia); one case patient died. The median age of resident case patients was 87 years. We could identify neither the source of the outbreak nor significant risk factors for infection and severe illness in residents. However, residents with a higher level of physical activity were more likely to become infected, whereas older residents (aged more than 85 years) and those with a lower level of physical activity were more likely to develop severe illness (P>.05). Contact with residents was a risk factor for infection in staff (relative risk, undefined; P = .04).Conclusions.: C. pneumoniae can cause large outbreaks of infection and severe illness among elderly persons, and its transmission is likely to be enhanced by close contacts among people in nursing homes. Therefore, early detection of an outbreak by means of better surveillance, and subsequent isolation of patients, may be effective control measures.

1 March 2018 in Emerging Infectious Diseases
Verified
Journal Article
Open access
IYIkkoh Yasuda
Ikkoh Yasuda
HMHisayo Matsuyama
Hisayo Matsuyama
TITomoko Ishifuji
Tomoko Ishifuji
YYYoshiro Yamashita
Yoshiro Yamashita
MTMasahiro Takaki
Masahiro Takaki
TTTakeshi Tanaka
Takeshi Tanaka
Corynebacterium ulcerans infection was recently recognized as a zoonosis. We present 2 cases of severe pneumonia complicated by diffuse pseudomembrane formation on the bronchus caused by C. ulcerans–producing diphtheria toxin. Our purpose is to alert medical professionals to the virulence of Corynebacterium species other than C. diphtheriae.

19 August 2021 in PLOS ONE
Verified
Journal Article
Open access
PDF file
TTTakeshi Tanaka
Takeshi Tanaka
KOKazuhiro Oshima
Kazuhiro Oshima
KKKei Kawano
Kei Kawano
MTMasato Tashiro
Masato Tashiro
ATAkitaka Tanaka
Akitaka Tanaka
KIKoichi Izumikawa
Koichi Izumikawa
Objectives: The accurate prevalence of acquired immunodeficiency syndrome (AIDS)-defining illnesses (ADIs) in human immunodeficiency virus (HIV)-infected patients has not been well investigated. Hence, a longitudinal nationwide surveillance study analyzing the current status and national trend of opportunistic complications in HIV-infected patients in Japan is warranted. Methods: A nationwide surveillance of opportunistic complications in HIV-infected patients from 1995 to 2017 in Japan was conducted. An annual questionnaire was sent to 383 HIV/AIDS referral hospitals across Japan to collect information (CD4+ lymphocyte count, time of onset, outcome, and antiretroviral therapy [ART] status) of patients diagnosed with any of 23 ADIs between 1995 and 2017. Results: The response and case capture rates of the questionnaires in 2017 were 53% and 76%, respectively. The number of reported cases of opportunistic complications peaked in 2011 and subsequently declined. Pneumocystis pneumonia (38.7%), cytomegalovirus infection (13.6%), and candidiasis (12.8%) were associated with the cumulative incidence of ADIs between 1995 and 2017. The mortality rate in HIV-infected patients with opportunistic complications substantially decreased to 3.6% in 2017. The mortality rate was significantly higher in HIV patients who received ART within 14 days of diagnosis of complications than in those who received ART 15 days after diagnosis (13.0% vs. 3.2%, p < 0.01). Conclusions: We have demonstrated a 23-year trend of a newly diagnosed AIDS status in Japan with high accuracy. The current data reveal the importance of Pneumocystis pneumonia as a first-onset illness and that early initiation of ART results in poor outcomes in HIV patients in Japan.

13 April 2022 in Journal of Infection and Chemotherapy
Verified
Journal Article
Closed access
KSKoki Shimizu
Koki Shimizu
HMHaruka Maeda
Haruka Maeda
ESEiichiro Sando
Eiichiro Sando
AFAyumi Fujita
Ayumi Fujita
MTMasato Tashiro
Masato Tashiro
KMKonosuke Morimoto
Konosuke Morimoto