Teppei Sasahara
Jichi Medical University
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Publication
Featured researches published by Teppei Sasahara.
European Journal of Clinical Microbiology & Infectious Diseases | 2011
Teppei Sasahara; Shunji Hayashi; Yuji Morisawa; T. Sakihama; A. Yoshimura; Yoshikazu Hirai
We describe an outbreak of Bacillus cereus bacteremia that occurred at Jichi Medical University Hospital in 2006. This study aimed to identify the source of this outbreak and to implement appropriate control measures. We reviewed the charts of patients with blood cultures positive for B. cereus, and investigated B. cereus contamination within the hospital environment. Genetic relationships among B. cereus isolates were analyzed. Eleven patients developed B. cereus bacteremia between January and August 2006. The hospital linens and the washing machine were highly contaminated with B. cereus, which was also isolated from the intravenous fluid. All of the contaminated linens were autoclaved, the washing machine was cleaned with a detergent, and hand hygiene was promoted among the hospital staff. The number of patients per month that developed new B. cereus bacteremia rapidly decreased after implementing these measures. The source of this outbreak was B. cereus contamination of hospital linens, and B. cereus was transmitted from the linens to patients via catheter infection. Our findings demonstrated that bacterial contamination of hospital linens can cause nosocomial bacteremia. Thus, blood cultures that are positive for B. cereus should not be regarded as false positives in the clinical setting.
PLOS ONE | 2012
Masataka Oda; Manabu Hashimoto; Masaya Takahashi; Yuka Ohmae; Soshi Seike; Ryoko Kato; Aoi Fujita; Hideaki Tsuge; Masahiro Nagahama; Sadayuki Ochi; Teppei Sasahara; Shunji Hayashi; Yoshikazu Hirai; Jun Sakurai
Bacillus cereus (B. cereus) is a pathogen in opportunistic infections. Here we show that Bacillus cereus sphingomyelinase (Bc-SMase) is a virulence factor for septicemia. Clinical isolates produced large amounts of Bc-SMase, grew in vivo, and caused death among mice, but ATCC strains isolated from soil did not. A transformant of the ATCC strain carrying a recombinant plasmid containing the Bc-SMase gene grew in vivo, but that with the gene for E53A, which has little enzymatic activity, did not. Administration of an anti-Bc-SMase antibody and immunization against Bc-SMase prevented death caused by the clinical isolates, showing that Bc-SMase plays an important role in the diseases caused by B. cereus. Treatment of mouse macrophages with Bc-SMase resulted in a reduction in the generation of H2O2 and phagocytosis of macrophages induced by peptidoglycan (PGN), but no effect on the release of TNF-α and little release of LDH under our experimental conditions. Confocal laser microscopy showed that the treatment of mouse macrophages with Bc-SMase resulted in the formation of ceramide-rich domains. A photobleaching analysis suggested that the cells treated with Bc-SMase exhibited a reduction in membrane fluidity. The results suggest that Bc-SMase is essential for the hydrolysis of SM in membranes, leading to a reduction in phagocytosis.
Journal of Infection and Chemotherapy | 2017
Takashi Ikeda; Jun Suzuki; Masataro Norizuki; Taro Okabe; Tsubasa Onishi; Teppei Sasahara; Masaki Toshima; Hidenori Yokota; Shuji Hatakeyama; Yuji Morisawa
Glioblastoma is an aggressive brain tumor that requires multidisciplinary treatment including adjuvant radiotherapy, chemotherapy, and adjunct corticosteroids. Temozolomide is a commonly used chemotherapy drug and frequently causes lymphocytopenia. We describe the case of a 67-year-old woman with cutaneous invasive aspergillosis who had received long-term temozolomide and corticosteroid therapy for glioblastoma. She presented with multiple indurations, erythema, and purpura, some of which produced purulent discharge, in the anterior abdomen. Extensive intra- or inter-muscular abscesses of the right anterior abdominal wall were also observed. Her absolute lymphocyte counts were 156/μL on admission. Cultures obtained from the wound yielded Aspergillus fumigatus. She was diagnosed with secondary cutaneous invasive aspergillosis, which likely resulted from hematogenous dissemination. Although rare, this case illustrates that temozolomide-induced lymphocytopenia, especially in cases of concomitant corticosteroid use, can be associated with severe invasive aspergillosis.
Genome Announcements | 2016
Shinya Watanabe; Teppei Sasahara; Naoshi Arai; Kazumasa Sasaki; Yoshifumi Aiba; Yusuke Sato’o; Longzhu Cui
ABSTRACT Acute phlegmonous gastritis is an uncommon endogenous bacterial gastritis presenting with a high mortality rate. Here, we report the complete genome sequence of an emm89 Streptococcus pyogenes strain, JMUB1235, which is the causative agent of acute phlegmonous gastritis.
Clinical medicine insights. Case reports | 2015
Masataro Norizuki; Teppei Sasahara; Harumi Gomi; Yuji Morisawa; Noriko Takamura; Tsuneaki Kenzaka; Tetsuro Kobayashi; Yoshihiro Fujiya; Yasuyuki Kato; Hiroyuki Matsuoka
A 46-year-old Japanese female expatriate living in Jakarta presented with intermittent fever lasting for a month. Although she was considered at low risk of Fasciola spp. infection because she lived in an upper-class residential area of the city, the patient presented with eosinophilia after consuming organic raw vegetables; in addition, contrast-enhanced computed tomography detected microabscesses in a tractlike pattern in the liver. These findings led to an early diagnosis of fascioliasis, which was successfully treated without sequelae. In any patient with a history of consuming raw vegetables, fascioliasis should be suspected regardless of where the patient has lived.
BMC Psychiatry | 2018
Izumi Chihara; Ryusuke Ae; Yuka Kudo; Ritei Uehara; Nobuko Makino; Yuri Matsubara; Teppei Sasahara; Yasuko Aoyama; Kazuhiko Kotani; Yosikazu Nakamura
BackgroundIn Japan, although many suicidal studies were previously conducted in tertiary emergency department (ED) settings, no published studies have reported on suicidal patients presenting to the secondary EDs. The aim of the study was to describe the characteristics of suicidal patients and the referral rates to a psychiatrist overall and by type of facility.MethodsQuestionnaires were sent to all secondary and tertiary EDs in Tochigi prefecture, Japan. Data were collected for cases who presented in September 2009. Chi-square, Fisher’s exact, and t-tests compared the results by gender and type of ED.ResultsAll 74 EDs responded to the survey. There were 81 patients who attempted or died by suicide (36 men and 45 women). The most common method of suicide attempt was drug overdose (57%) followed by stabbing (17%). About a half used prescription drugs to attempt or die by suicide. The majority had a history of psychiatric disorders, and 35% had previous suicide attempt. About a half were admitted to medical or surgical unit; 33% were discharged home; and 9% died. After excluding those who died, 53% were referred to a psychiatrist, but 47% were not referred to a psychiatrist. The referral rate was lower for cases seen at secondary EDs (38%) compared to tertiary EDs (67%).ConclusionAlthough professional organizations suggest that suicidal patients are seen by a psychiatrist, many were not, especially at secondary EDs. Further research is needed to assure that suicidal patients presenting to EDs receive appropriate psychiatric assessment and follow-up after discharge.
Case Reports in Oncology | 2017
Masanori Ogawa; Ryusuke Ae; Teppei Sasahara
In the current study, we report a case of a 46-year-old man who presented with sudden abdominal pain and was diagnosed with rupture of hepatic angiosarcoma (HAS). He underwent surgery, but died 13 days after the onset of the abdominal pain. Chronic exposure to carcinogens, such as thorium dioxide, arsenic, vinyl chloride, and radium, is associated with HAS. However, our patient had not been exposed to such carcinogens. He had submitted himself for annual medical checkups since he was employed. His liver was cirrhotic, and medical history data showed that he had had fatty liver for at least 10 years before HAS onset. Although liver cirrhosis may play a role in the occurrence of HAS, the connection of chronic fatty liver in the tumorigenesis remains unclear. Case reports regarding HAS with fatty liver are few. To the best of our knowledge, this is the first case of HAS occurring in a cirrhotic liver that advanced from persistent fatty stage. Given that HAS is a rare tumor, data collection is important for investigating its pathophysiology. Case presentations considering health conditions before HAS onset are limited; therefore, we present a case of HAS with annual health checkup data before disease onset.
IDCases | 2015
Jun Suzuki; Teppei Sasahara; Masaki Toshima; Masataro Norizuki; Tsubasa Onishi; Taro Okabe; Kensuke Minami; Yuji Morisawa
A 40-year-old Japanese man with acquired immunodeficiency syndrome was diagnosed with Kaposi sarcoma (KS) on the basis of the results of skin lesion biopsies. In addition, 18F-fluorodeoxyglucose-position emission tomography–computed tomography revealed abnormal fluorodeoxyglucose uptake in KS lesions, whereas gallium-67 scintigraphy did not show uptake of gallium. These findings indicate that combining these imaging modalities can help distinguish KS from other malignancies and opportunistic infections.
Journal of Occupational Medicine and Toxicology | 2012
Masanori Ogawa; Teppei Sasahara
BackgroundBiological monitoring is used to assess toluene exposure in medical examinations. The American Conference of Industrial Hygienists, Japanese Society for Occupational Health and Deutsche Forschungsgemeinschaft have proposed various biological exposure determinants, such as toluene in blood and urine, and o-cresol in urine. Toluene in blood is a common biomarker among them. Toluene is a volatile organic solvent; therefore, sample preservation under appropriate conditions before measurement is necessary. However, little study has been done on the stability of toluene in workers’ blood samples under conditions simulating those of a medical examination.FindingWe carried out a pilot study on the stability of toluene in blood from humans, according to different methods of sample preservation. Toluene in blood was analyzed by head space-gas chromatography/mass spectrometry. The sealing performance of the vial was examined by using toluene-added blood and the stability of toluene in blood according to the preservation period was examined by using blood from toluene-handling workers, which was collected with vacuum blood tubes. The sealing performance of the headspace vial used in this study was good for three days and toluene in blood in tubes from workers was stable at least within 8 hours up to blood packing at 4°C.ConclusionWe could propose that the collected blood need only be transferred into headspace vials on the collection day and analyzed within a few days, if the samples are preserved at 4°C. Our data size is limited; however, it may be considered basic information for biological monitoring in medical examinations.
Biocontrol Science | 2014
Teppei Sasahara; Shunji Hayashi; Kouichi Hosoda; Yuji Morisawa; Yoshikazu Hirai