Makoto Motoyoshi

The University of Tokyo, Edo, Tōkyō, Japan

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Publications (4)7.9 Total impact

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    ABSTRACT: In acute pancreatitis, pancreatic phospholipase A(2) (PLA2) in the circulating blood hydrolyzes phospholipids contained in plasma lipoproteins, liberating eicosanoid precursors that are subsequently converted to various eicosanoids. The pathophysiological significance of eicosanoid synthesis via this pathway is unknown. The aim of this study was to clarify the role of thromboxane A(2) (TXA(2)) synthesis by circulating pancreatic PLA(2) in the pathogenesis of the systemic complications of acute pancreatitis. Guinea pigs were divided into two groups: a control group and an ozagrel group, which received intravenous administration of ozagrel, a selective TXA(2) synthetase inhibitor. Pancreatic PLA(2) was infused intravenously in both groups for 30 min, and systemic changes during the infusion were examined. In the control group, there was an increase in plasma thromboxane B(2) (TXB(2)) concentration, a decrease in mean arterial pressure and heart rate, a decrease in arterial base excess (BE), bicarbonate concentration (HCO(3) (-)), and pH, a decrease in platelet count and plasma fibrinogen concentration, and a shortened prothrombin time during the infusion of pancreatic PLA(2). In the ozagrel-treated group, changes in plasma TXB(2) concentration, BE, HCO(3) (-), and platelet count were significantly inhibited. TXA(2) synthesis by circulating pancreatic PLA(2) contributes to metabolic acidosis and thrombocytopenia during acute pancreatitis.
    No preview · Article · Dec 2006 · Journal of Gastroenterology

  • No preview · Article · Apr 2006 · Surgery
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    ABSTRACT: Background. In acute pancreatitis, pancreatic phospholipase A2 increases in systemic circulation. Yet the pathophysiological significance is controversial, because previous in vitro studies have shown that the enzyme has little cytotoxicity or ability to activate the arachidonic acid cascade by itself in contrast to other isozymes. Aim of the Study. The aims of this study are to examine the effect of pancreatic phospholipase A2 on the arachidonic acid cascade in vivo; to explain the discrepancy, if present, between in vitro and in vivo findings; and to reassess the pathophysiological significance of circulating pancreatic phospholipase A2. Methods. Pancreatic phospholipase A2 was infused intravenously in guinea pigs, and changes in the arachidonic acid cascade, plasma lipoprotein, and cardiopulmonary function were investigated. Results. Plasma concentrations of 6-keto-prostaglandin F1α, prostaglandin E2, and thromboxane B2 increased after intravenous (iv) infusion of pancreatic phospholipase A2. Some of the plasma phospholipids such as phosphatidylcholine and phosphatidylethanolamine decreased, and free dihomo-γ-linolenic acid, arachidonic acid, and eicosapentaenoic acid were detected in plasma. These changes were accompanied with decreases in blood pressure, heart rate, and base excess. Conclusion. Circulating pancreatic phospholipase A2 activates the arachidonic acid cascade, probably by supplying free eicosanoid precursors from plasma lipoprotein to eicosanoid-producing cells. It is supposed to be a cause of systemic complications in acute pancreatitis.
    No preview · Article · Feb 2001 · International Journal of Gastrointestinal Cancer
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    ABSTRACT: A case of Cronkhite-Canada syndrome associated with a gastric cancer is reported with review of the literature. A 50-year-old man was admitted to the hospital with a half year history of epigastralgia, hypogeusia, diarrhea and alopetia. Physical examination revealed hyperpigmentation, onychodystrophy, redness of tongue with atrophy of lingual papilla, and a hard tumor was palpated in the epigastrium. On gastroscopy, numerous small sessile polyps with reddish edematous mucosa were observed throughout the stomach and a Borrmann III type gastric cancer was detected in the antrum. Under the diagnosis of Cronkhite-Canada syndrome associated with gastric cancer, the patient underwent a distal gastrectomy. Histological type of the cancer was that of well to moderately differentiated adenocarcinoma and the stage grouping was IIIb. Histological features of polyps were consistent with juvenile type polyps. There have been 16 cases of the syndrome associated with a gastric cancer in Japan, including ours. Comparing to patients with the syndrome without gastric cancer, male patients were predominant in those with gastric cancer. Of associated gastric cancers, differentiated type early carcinomas were common. Patients with Cronkhite-Canada syndrome were associated with gastric cancer in a significantly higher incidence (6.4%) than that in the general population. Consequently close examination at the onset of the syndrome and strict observation of clinical course are recommended.
    No preview · Article · Jan 1998 · Nihon Rinsho Geka Gakkai Zasshi (Journal of Japan Surgical Association)