Masao Omata
University of Tokyo
CancerInternal medicineRadiologyEndocrinologySurgeryPathologyOncologyMolecular biologyVirologyCardiologyChemistryImmunologyHepatitis C virusCirrhosisHepatocellular carcinomaHepatologyCancer researchMedicineBiologyGastroenterology
1,329Publications
128H-index
44.2kCitations
Publications 1334
Newest
#1Yosuke HirotsuH-Index: 18
#2Masao Omata (UTokyo: University of Tokyo)H-Index: 128
Abstract null null Background null The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) circulates in the world and acquires mutations during evolution. To identify the new emergent variants, the surveillance of the variants of concern (VOC) and variants of interest (VOI) is ongoing. This study aimed to determine how the transition of viral lineage occurred by stationary genome analysis in Yamanashi, Japan. null null null Methods null We performed the whole genome sequencing using SA...
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#1Mamoru Tokunaga (Chiba University)H-Index: 1
#2Kenichiro Okimoto (Chiba University)H-Index: 12
Last. Kazuyuki Matsushita (Chiba University)H-Index: 26
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The genetic characteristics of Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC) in the Japanese population is unclear. This study aims to investigate the genetic characteristics from nondysplastic BE (NDBE) to early EAC in Japan. Clinical information was collected. Moreover, the genetic profile of NDBE without concurrent dysplasia, early EAC, and surrounding BE were also investigated using endoscopic biopsy samples and formalin-fixed, paraffin-embedded specimens from Japanese patient...
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#1Yosuke HirotsuH-Index: 18
#2Kenji AmemiyaH-Index: 14
Last. Masao Omata (UTokyo: University of Tokyo)H-Index: 128
view all 7 authors...
Background null Vaccines against severe acute respiratory syndrome coronavirus 2 can trigger acquired immunity in infection-naive individuals and offer a path toward ending the coronavirus disease pandemic that began in 2019. However, the kinetics of early antibody responses in vaccinated individuals remain poorly understood. null Method null We followed BNT162b2 mRNA-vaccinated health care workers (HCWs, N=108) including 103 infection-naive and five previously infected individuals. A total of 7...
4 CitationsSource
#1George Lau (Chinese PLA General Hospital)H-Index: 6
#2Ming-Lung Yu (KMU: Kaohsiung Medical University)H-Index: 60
Last. Gregory Cheng (Chinese PLA General Hospital)H-Index: 7
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Hepatitis B reactivation related to the use of immunosuppressive therapy remains a major cause of liver-related morbidity and mortality in hepatitis B endemic Asia-Pacific region. This clinical practice guidelines aim to assist clinicians in all disciplines involved in the use of immunosuppressive therapy to effectively prevent and manage hepatitis B reactivation. All publications related to hepatitis B reactivation with the use of immunosuppressive therapy since 1975 were reviewed. Advice from ...
1 CitationsSource
#1Kentaro Ishikawa (Chiba University)H-Index: 6
#2Kenichiro Okimoto (Chiba University)H-Index: 12
Last. Naoya Kato (Chiba University)H-Index: 17
view all 18 authors...
Barrett’s esophagus (BE) is a precursor of esophageal adenocarcinoma (EAC). Therefore, an accurate diagnosis of BE is important for the subsequent follow-up and early detection of EAC. However, the definitions of BE have not been standardized worldwide; columnar-lined epithelium (CLE) without intestinal metaplasia (IM) and/or 1 cm (Group A) and those without IM and/or < 1 cm (Group B). Malignant potential was assessed using immunochemical staining for p53. Moreover, causative genes were examined...
1 CitationsSource
Background The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) circulates in the world and acquires mutations during evolution. To identify the new emergent variants, the surveillance of the variants of concern (VOC) and variants of interest (VOI) is ongoing. This study aimed to determine how the transition of viral lineage occurred by stationary genome analysis in Yamanashi, Japan. Methods We performed the whole genome sequencing using SARS-CoV-2 positive samples (n=325) collected ...
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#1Rumi HiguchiH-Index: 6
#2Taichiro GotoH-Index: 19
Last. Masao OmataH-Index: 128
view all 9 authors...
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#1Hiroshi Ohyama (Chiba University)H-Index: 7
#2Yosuke HirotsuH-Index: 18
Last. Masao Omata (UTokyo: University of Tokyo)H-Index: 128
view all 10 authors...
Background/purpose There are limitations in obtaining sufficient pancreatobiliary tumor tissue for genomic profiling of tumors. Herein, we investigated whether archived cytological specimen (ACS) is suitable for genomic profiling to identify oncogenic and drug-matched mutations. Methods We constructed a pancreatobiliary cancer panel for targeted sequencing covering 60 significantly mutated genes (280,220 bp). Eighty DNA samples (19 formalin-fixed paraffin-embedded (FFPE) tissues and 61 ACS) from...
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We aimed to investigate novel emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) lineages in Japan that harbor variants in the spike protein receptor-binding domain (RBD). The total nucleic acid contents of samples from 159 patients with coronavirus disease 2019 (COVID-19) were subjected to whole genome sequencing. The SARS-CoV-2 genome sequences from these patients were examined for variants in spike protein RBD. In January 2021, three family members (one aged in their 40s an...
10 CitationsSource
#1Yosuke HirotsuH-Index: 18
#2Hiroki SugiuraH-Index: 1
Last. Masao Omata (UTokyo: University of Tokyo)H-Index: 128
view all 9 authors...
BACKGROUND Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to spread worldwide. Here, we evaluated the performance of two quantitative antigen (Ag) tests, the Roche and Lumipulse Ag test, using automated platforms. METHODS We collected 637 nasopharyngeal swab samples from 274 individuals. Samples were subjected to quantitative reverse transcription PCR (RT-qPCR) as well as the Roche and Lumipulse Ag tests. RESULTS When RT-qPCR was used as a reference, the overall concordan...
1 CitationsSource