Publications by authors named "Ken-Ichi Katsu"

A case of primary NK/T-cell lymphoma of the rectum accompanied with ulcerative colitis (UC) in a 73-year-old man is reported. He had a 6-year history of repeated admission to our hospital for UC. Total colonoscopy performed 4 months after resolution of refractory UC complicated by cytomegalovirus colitis showed a markedly submucosal tumor in the rectum, which was histologically diagnosed as malignant lymphoma.

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Patients with ulcerative colitis (UC) exhibit an increased risk for the development of cancer of the colon and rectum. This association is widely attributed to colonic inflammation. However, the severity of colonic inflammation necessary for the development of dysplasia and/or cancer remains unknown.

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Background: Chemoradiotherapy (CRT) is currently performed for patients with esophageal squamous cell carcinoma (SCC). Some reports have revealed that patients who responded well to CRT had favorable outcomes, whereas poor responders conversely showed a worse prognosis. The aim of this study was to identify molecular markers predicting sensitivity to CRT.

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Purpose: To evaluate the association between dihydropyrimidine dehydrogenase (DPD) and thymidylate synthase (TS) levels in primary gastric tumors and clinical response to S-1 or S-1 plus irinotecan in patients with unresectable advanced gastric cancer, and to investigate the molecular mechanism of augmented antitumor activity of the combination using human gastric cancer xenografts with high TS activity.

Materials And Methods: TS mRNA expression and DPD mRNA expression were measured by reverse transcription polymerase chain reaction in initial primary cancer biopsy specimens in 29 patients with advanced gastric cancer who had received S-1 alone (n=18) or in combination with irinotecan (n=11). In an experimental study, antitumor effects of S-1, irinotecan, and the combination were assessed in mice bearing human gastric tumors with high TS expression (4-1-ST and AZ-521 tumors) and low TS expression (SC-2 tumors), and activities of 5-fluorouracil-metabolizing enzymes were measured.

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Background: Patients with ulcerative colitis (UC) exhibit an increased risk for the development of cancer of the colon and rectum. Cyclooxygenase (COX)-2 inhibitors are known to suppress sporadic colorectal cancer, but it is unknown whether selective COX-2 inhibitors exhibit a preventive effect in UC-associated neoplasia. This study investigated the preventive effect of nimesulide, a selective COX-2 inhibitor, on colorectal carcinogenesis in an experimental model of murine UC.

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Background: Recently, attention has been directed to concurrent chemoradiotherapy (CRT) for the treatment of squamous cell carcinoma of the esophagus with regard to efficacy, quality of life and functional preservation, and survival periods comparable to those after standard surgical therapy have been reported in responders to CRT. However, there are some non-responders to CRT, and the prediction of the outcome after CRT is an important subject for future studies. In this study, using biopsy specimens obtained before CRT, we evaluated the relationships between biological markers and the outcome after CRT in order to determine the prognostic factors of CRT.

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The effects of intracellular Cl- concentration ([Cl-]i) on acetylcholine (ACh)-stimulated exocytosis were studied in guinea pig antral mucous cells by video microscopy. ACh activated Ca2+-regulated exocytosis (an initial phase followed by a sustained phase). Bumetanide (20 microM) or a Cl- -free (NO3-) solution enhanced it; in contrast, 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB, a Cl- channel blocker) decreased it and eliminated the enhancement induced by bumetanide or NO3- solution.

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Background/aims: Helicobacter pylori (HP) infection is reported to be involved in gastric carcinogenesis. However, only a small percentage of HP-infected patients actually develop gastric cancer. In the present study, we assessed HLA antigen polymorphism and investigated its relationship with the development of gastric epithelial tumors in patients who had HP infection.

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Aim: To evaluate the effect of pyrrolidine dithio-carbamate (PDTC; an NF-kappaB inhibitor) administered at low (50 mg/kg) and high (100 mg/kg) doses in suppressing colitis in mice with dextran sodium sulfate (DSS)-induced colitis.

Methods: Mice were divided into a DSS-untreated group (normal group), DSS-treated control group, DSS+PDTC-treated group I (low-dose group), and DSS+PDTC-treated group II (high-dose group). In each group, the disease activity index score (DAI score), intestinal length, histological score, and the levels of activated NF-kappaB and inflammatory cytokines (IL-1beta and TNF-alpha) in tissue were measured.

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Background/aims: Various studies have indicated a relationship between Helicobacter pylori infection and upper gastrointestinal lesions, but this relationship needs to be assessed in individuals not seeking medical treatment for complaints.

Methodology: We screened community residents for H. pylori infection and upper gastrointestinal lesions during an annual mass health examination aiming to determine relationships between infection and lesions.

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Prostaglandin E(2) (PGE(2)), which is generated by two isoforms of cyclo-oxygenase (COX(1) and COX(2)), is a key mediator in gastric mucosal defense. In the present study, antral mucosa of guinea-pigs was incubated with various agonists or antagonists in a medium, the PGE(2) concentration of which was measured using a PGE(2) EIA kit. Prostaglandin E(2) was released from the antral mucosa spontaneously (basal PGE(2) release) and acetylcholine (ACh, 10 microM) enhanced the PGE(2) release (ACh-stimulated PGE(2) release) was mediated via intracellular Ca(2+) concentration ([Ca(2+)](i)).

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Paclitaxel is one of the new drugs against advanced/recurrent gastric cancer. We report its efficacy and toxicity with weekly administration for advanced/recurrent gastric cancer. We administered 26 patients (postoperative/non-operation=9/17) PTX 80 mg/m(2)by 1-hour intravenous infusion once a week for 3 weeks followed by one week rest.

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Objective: To detect the expression of gamma-aminobutyric acid (GABA) and glutamic acid decarboxylases (GADs; including two isoforms GAD65 and GAD67) in the epithelial growth zones of the descending colon in rats, and to investigate their relation to epithelial differentiation and proliferation.

Methods: The expression of GABA and GADs in rat descending colon was investigated by immunofluorescent staining and confocal laser scanning techniques, and goblet cells were further investigated by wheat-germ agglutinin histochemistry. In addition, GAD65 and GAD67 mRNAs were also detected by reverse transcription-polymerase chain reaction.

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A 74-year-old man was revealed to have type 3 gastric cancer with synchronous multiple liver metastases. Despite treatment with TS-1 (120 mg/body), an increase in tumor size was demonstrated by computer tomography and endoscopy. We tried a course of a combination chemotherapy consisting of paclitaxel (PTX) plus doxifluridine (5'-DFUR ) to reduce the tumor.

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In guinea pig antral mucous cells, ACh stimulates the Ca(2+)-regulated exocytosis, which has a characteristics feature: an initial transient phase followed by a sustained phase. The effects of cGMP on ACh-stimulated exocytosis were studied in guinea pig antral mucous cells using video microscopy. cGMP enhanced the frequency of ACh-stimulated exocytotic events, whereas cGMP alone did not induce any exocytotic events under the ACh-unstimulated condition.

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Chemotherapy-induced nausea and vomiting (emesis) can significantly affect a patient's quality of life, leading to poor compliance with further chemotherapy treatment. For patients treated with emetogenic chemotherapy, it is very important to prevent nausea and vomiting completely. The incidence and severity of nausea and/or vomiting in patients receiving chemotherapy are affected by numerous factors, including: 1) the specific chemotherapeutic agents used; 2) their dosage; 3) the schedule and route of administration; and 4) individual patient variability.

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Ca2+-regulated exocytosis is enhanced by an autocrine mechanism via the PGE2-cAMP pathway in antral mucous cells of guinea-pigs. The inhibition of the PGE2-cAMP pathway by H-89 (an inhibitor of protein kinase A, PKA) or aspirin (ASA, an inhibitor of cyclo-oxygenase, COX) decreased the frequency of ACh-stimulated exocytotic events by 60%. Indomethacin (IDM, an inhibitor of COX), however, decreased the frequency of ACh-stimulated exocytotic events only by 30%.

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Objective: A dose-escalation study of irinotecan (CPT-11) combined with S-1, a novel oral fluoropyrimidine, was performed to determine the maximum-tolerated dose (MTD), recommended dose (RD) and dose-limiting toxicities (DLTs) in advanced gastric cancer.

Methods: S-1 was administered orally at 80 mg/m(2)/day for 21 consecutive days followed by a 2 week rest. CPT-11 was given intravenously on days 1 and 15 of each course, at an initial dose of 40 mg/m(2)/day, stepping up to 60, 80, 100 or 120 mg/m(2)/day depending on the DLT.

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Various hepato-biliary complications are an increased incidence in patients with inflammatory bowel disease, and portal bacteremia is well documented in patients with ulcerative colitis (UC). However, few reports mention UC in association with liver abscesses. Recently, there are several reports describing cytomegalovirus (CMV) infection in association with disease exacerbation and steroid refractoriness in patients with UC.

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The effects of indomethacin (IDM) and aspirin (ASA) on ACh (10 microM) -stimulated exocytotic events were studied in guinea pig antral mucous cells by using video optical microscopy. IDM or ASA, which inhibits cyclooxygenase (COX), decreased the frequency of ACh-stimulated exocytotic events by 30% or 60%, respectively. The extent of inhibition induced by ASA (60%) decreased by 30% when IDM or arachidonic acid (AA, the substrate of COX) was added.

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Terbutaline (10 microm) induced a triphasic volume change in alveolar type II (AT-II) cells: an initial shrinkage (initial phase) followed by cell swelling (second phase) and a gradual shrinkage (third phase). The present study demonstrated that the initial and the third phases are evoked by the activation of K+ and Cl- channels and the second phase is evoked by the activation of Na+ and Cl- channels. Ouabain blocked the third phase, although it did not block the initial and second phases.

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A 75-year-old man was admitted to our hospital complaining of gastric fatigue. Endoscope and CT scan revealed type 3 gastric cancer with paraaortic lymph nodal metastasis. Histological examination of the endoscopic biopsy revealed poorly differentiated adenocarcinoma.

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Background: Epidermal growth factor (EGF) has an anti-ulcer effect, but the mechanisms of this gastric mucosal protection are incompletely understood. We have suggested the importance of mucin as a mucosal protectant. We investigated whether increased mucin biosynthesis might be involved in the gastric mucosal protection conferred by EGF.

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Article Synopsis
  • The study aims to compare how early colorectal carcinoma (CRC) is classified by endoscopists in Japan and China.
  • Ten cases of early CRC were reviewed by five Japanese and five Chinese endoscopists using the existing Japanese classification system, leading to different diagnoses for some lesions.
  • The findings highlight significant discrepancies in the classification terms and the recognition of certain lesions, indicating a need for better international communication to establish a universal classification system for CRC.
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