Publications by authors named "Kiyoshi Saeki"

Background: Coronavirus disease 2019 (COVID19) can cause gastrointestinal complications as well as respiratory tract disease. Coagulation abnormalities and thrombosis frequently occur in COVID19, especially in cases with severe clinical outcome. The relationship between gastrointestinal perforation and coagulopathy due to COVID19 remains unclear.

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Background & Aims: Pancreatic ductal adenocarcinoma can develop from precursor lesions, including pancreatic intraepithelial neoplasia and intraductal papillary mucinous neoplasm (IPMN). Previous studies indicated that loss of Acvr1b accelerates the Kras-mediated development of papillary IPMN in the mouse pancreas; however, the cell type predominantly affected by these genetic changes remains unclear.

Methods: We investigated the contribution of cellular origin by inducing IPMN associated mutations (KRAS expression and Acvr1b loss) specifically in acinar (Ptf1a;Kras;Acvr1b mice) or ductal (Sox9CreER;Kras;Acvr1b mice) cells in mice.

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Unlabelled: Expression of the Notch family of receptors is often upregulated in pancreatic ductal adenocarcinoma (PDAC). In this study, we focused on Notch4, which had not been investigated in PDAC. We generated KC (), N4 KC (), PKC (), and N4 PKC () genetically engineered mouse models (GEMM).

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Cases of "pancreatic ductal adenocarcinoma (PDAC) concomitant with intraductal papillary mucinous neoplasm" (IPMN) have multiple PDAC lesions more frequently than cases of "PDAC without IPMN". However, the mechanism of carcinogenesis in this former disease category remains unknown. The main objective of this work was thus to investigate the effects of chronic inflammation on carcinogenesis in PDAC cases.

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The PI3K signaling pathway is frequently mutated in head and neck squamous cell carcinoma (HNSCC), often via gain-of-function (GOF) mutations in the gene. Here, we present novel genetically engineered mouse models (GEMM) carrying a GOF allele (E20) alone or in combination with heterozygous - (p53) mutation with tissue-specific expression to interrogate the role of oncogenic in transformation of upper aerodigestive track epithelium. We demonstrated that the GOF mutation promoted progression of 4-nitroquinoline 1-oxide-induced oral squamous cell carcinoma (OSCC) in both E20 single mutant and E20/p53 double mutant mice, with frequent distal metastasis detected only in E20/p53 GEMM.

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Hypoxia is a characteristic feature of the tumor microenvironment in pancreatic ductal adenocarcinoma (PDAC). We have recently explored new targeting molecules and pathways in PDAC cells under hypoxic conditions. In this study, we performed a microarray experiment to analyze the genes up-regulated in PDAC cell lines under hypoxia compared to normoxia, and identified human family with sequence similarity 115, member C (FAM115C) as a candidate gene for further study.

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Oxaliplatin (l-OHP), a platinum-based drug, is a key chemotherapeutic agent for colorectal cancer (CRC), but drug resistance and toxic effects have been major limitations of its use. Synchrotron radiation X-ray fluorescence spectrometry (SR-XRF) is a rapid, nondestructive technique for monitoring the distribution of metals and trace elements in cells or tissue samples. We applied SR-XRF to visualize the distribution of platinum and other elements in 30 rectal cancer specimens resected from patients who received l-OHP-based preoperative chemotherapy and quantified platinum concentration in the tumor epithelium and stroma, respectively, using calibration curves.

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Background: Pancreatic ductal adenocarcinoma (PDAC) is a lethal neoplasm because of difficulties in early detection. Several studies have recently suggested that exosomes may have potential as novel biomarkers. This study aimed to isolate exosomes from pancreatic juice and to investigate whether exosomal microRNAs (ex-miRs) could be used as biomarkers for PDAC.

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Objective: To determine the factors predicting the subsequent development of pancreatic ductal adenocarcinoma in remnant pancreas (PDAC-RP) after partial pancreatectomy for PDAC.

Summary Background Data: PDAC-RP after partial pancreatectomy for PDAC is currently not so rare because of improved prognosis of PDAC patients due to recent advances in surgical techniques and adjuvant therapy. However, the predictive factors related to PDAC-RP remain unknown.

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"Mucoepidermoid carcinoma (MEC)" has been accepted as a synonym for pancreatic adenosquamous carcinoma (ASC). Pancreatic ASC can show salivary gland-type MEC-like morphology. CRTC1/3-MAML2 fusion gene is a characteristic molecular feature of MEC of the salivary gland.

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Background: Intraductal tubulopapillary neoplasm (ITPN) is a rare pancreatic intraductal neoplasm. It is characterized by a tubulopapillary growth pattern, entirely high-grade atypical cells, minimal cytoplasmic mucin, and no obvious luminal mucin secretion. Most of its biological nature remains unclear.

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The use of laparoscopic surgery in the treatment of Mirizzi syndrome is considered controversial due to the degree of technical difficulty. We herein describe the case of a 36-year-old woman who was admitted to our hospital due to appetite loss, nausea and back pain. Endoscopic retrograde cholangiography revealed a round-shaped filling defect at the confluence of the bile duct.

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Aim: Solid pseudopapillary neoplasm (SPN) is an uncommon pancreatic tumour characterised by solid and pseudopapillary growth patterns. We have observed SPNs can show a microcystic pattern (microcystic SPN), which has been poorly described and may be confused with microcystic neoplasms. We conducted the present study to clarify the clinicopathological and immunohistochemical features of microcystic SPNs.

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